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1611.05852
Robert Lasenby
Edward Hardy, Robert Lasenby
Stellar cooling bounds on new light particles: plasma mixing effects
36 pages, 7 figures; explanations clarified, results unchanged; matches version published in JHEP
JHEP 02 (2017) 033
10.1007/JHEP02(2017)033
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Strong constraints on the coupling of new light particles to the Standard Model (SM) arise from their production in the hot cores of stars, and the effects of this on stellar cooling. For new light particles which have an effective in-medium mixing with the photon, plasma effects can result in parametrically different production rates to those obtained from a naive calculation. Taking these previously-neglected contributions into account, we make updated estimates for the stellar cooling bounds on light scalars and vectors with a variety of SM couplings. In particular, we improve the bounds on light (m <~ keV) scalars coupling to electrons or nucleons by up to 3 orders of magnitude in the coupling squared, significantly revise the supernova cooling bounds on dark photon couplings, and qualitatively change the mass dependence of stellar bounds on new vectors. Scalars with mass <~ 2 keV that couple through the Higgs portal are constrained to mixing angle <~ 3*10^-10, which gives the dominant bound for scalar masses above ~ 0.2 eV.
[ { "created": "Thu, 17 Nov 2016 20:47:41 GMT", "version": "v1" }, { "created": "Wed, 7 Dec 2016 18:59:11 GMT", "version": "v2" }, { "created": "Wed, 8 Feb 2017 05:49:09 GMT", "version": "v3" } ]
2017-02-09
[ [ "Hardy", "Edward", "" ], [ "Lasenby", "Robert", "" ] ]
Strong constraints on the coupling of new light particles to the Standard Model (SM) arise from their production in the hot cores of stars, and the effects of this on stellar cooling. For new light particles which have an effective in-medium mixing with the photon, plasma effects can result in parametrically different production rates to those obtained from a naive calculation. Taking these previously-neglected contributions into account, we make updated estimates for the stellar cooling bounds on light scalars and vectors with a variety of SM couplings. In particular, we improve the bounds on light (m <~ keV) scalars coupling to electrons or nucleons by up to 3 orders of magnitude in the coupling squared, significantly revise the supernova cooling bounds on dark photon couplings, and qualitatively change the mass dependence of stellar bounds on new vectors. Scalars with mass <~ 2 keV that couple through the Higgs portal are constrained to mixing angle <~ 3*10^-10, which gives the dominant bound for scalar masses above ~ 0.2 eV.
0906.2485
Fl. Stancu
Fl. Stancu
Can Y(4140) be a $c \bar c s \bar s$ tetraquark ?
new additional parts, published version
J.Phys.G37:075017,2010
10.1088/0954-3899/37/7/075017
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this exploratory study the spectrum of tetraquarks of type $c \bar c s \bar s$ is calculated within a simple quark model with chromomagnetic interaction and effective quark masses extracted from meson and baryon spectra. It is tempting to see if this spectrum can accommodate the resonance Y(4140), observed by the CDF collaboration, but not yet confirmed. The results seem to favour the J$^{PC}$ = 1$^{++}$ sector where the coupling to the VV channel is nearly as small as that of X(3872), when described as a $c \bar c q \bar q$ tetraquark. This suggests that Y(4140) could possibly be the strange partner of X(3872), in a tetraquark interpretation. However the sector J$^{PC}$ = 0$^{++}$ cannot entirely be excluded. This work questions the practice of extracting effective quark masses containing spin independent contributions, from mesons and baryons, to be used in multiquark systems as well.
[ { "created": "Sat, 13 Jun 2009 16:06:22 GMT", "version": "v1" }, { "created": "Thu, 18 Jun 2009 17:16:38 GMT", "version": "v2" }, { "created": "Tue, 15 Jun 2010 13:35:05 GMT", "version": "v3" } ]
2014-11-20
[ [ "Stancu", "Fl.", "" ] ]
In this exploratory study the spectrum of tetraquarks of type $c \bar c s \bar s$ is calculated within a simple quark model with chromomagnetic interaction and effective quark masses extracted from meson and baryon spectra. It is tempting to see if this spectrum can accommodate the resonance Y(4140), observed by the CDF collaboration, but not yet confirmed. The results seem to favour the J$^{PC}$ = 1$^{++}$ sector where the coupling to the VV channel is nearly as small as that of X(3872), when described as a $c \bar c q \bar q$ tetraquark. This suggests that Y(4140) could possibly be the strange partner of X(3872), in a tetraquark interpretation. However the sector J$^{PC}$ = 0$^{++}$ cannot entirely be excluded. This work questions the practice of extracting effective quark masses containing spin independent contributions, from mesons and baryons, to be used in multiquark systems as well.
2309.15052
Robinson Longas
Robinson Longas, Andres Rivera, Cristian Ruiz, David Suarez
Singlet-doublet Dirac fermion dark matter from Peccei-Quinn symmetry
27 pages, 6 figures and 2 tables
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Weakly Interacting Massive Particles (WIMPs) and axions are arguably the most compelling dark matter (DM) candidates in the literature. Here, we consider a model where the PQ symmetry solves the strong CP problem, generates radiatively Dirac neutrino masses, and gives origin to multicomponent dark sector. Specifically, scotogenic Dirac neutrino masses arise at one-loop level. The lightest fermionic mediator acts as the second DM candidate due to a residual $Z_2$ symmetry resulting from the PQ symmetry breaking. The WIMP DM component resembles the well-known singlet-doublet fermion DM. While the lower WIMP dark mass region is usually excluded, our model reopens that portion of the parameter space (for DM masses below $\lesssim 100$ GeV). Therefore, we perform a phenomenological analysis that addresses the constraints from direct searches of DM, neutrino oscillation data, and charged lepton flavor violating (LFV) processes. The model can be tested in future facilities where DM annihilation into SM particles is searched for by neutrino telescopes.
[ { "created": "Tue, 26 Sep 2023 16:30:16 GMT", "version": "v1" }, { "created": "Fri, 26 Jul 2024 19:24:14 GMT", "version": "v2" } ]
2024-07-30
[ [ "Longas", "Robinson", "" ], [ "Rivera", "Andres", "" ], [ "Ruiz", "Cristian", "" ], [ "Suarez", "David", "" ] ]
Weakly Interacting Massive Particles (WIMPs) and axions are arguably the most compelling dark matter (DM) candidates in the literature. Here, we consider a model where the PQ symmetry solves the strong CP problem, generates radiatively Dirac neutrino masses, and gives origin to multicomponent dark sector. Specifically, scotogenic Dirac neutrino masses arise at one-loop level. The lightest fermionic mediator acts as the second DM candidate due to a residual $Z_2$ symmetry resulting from the PQ symmetry breaking. The WIMP DM component resembles the well-known singlet-doublet fermion DM. While the lower WIMP dark mass region is usually excluded, our model reopens that portion of the parameter space (for DM masses below $\lesssim 100$ GeV). Therefore, we perform a phenomenological analysis that addresses the constraints from direct searches of DM, neutrino oscillation data, and charged lepton flavor violating (LFV) processes. The model can be tested in future facilities where DM annihilation into SM particles is searched for by neutrino telescopes.
hep-ph/0403157
Patrick Janot
Patrick Janot
Closing the light sbottom mass window from a compilation of e+e- -> hadron data
19 pages, 8 figures, 10 tables To be published in Physics Letters. This new version has been reshuffled with respect to the original version to include the suggestions from the Referees of Physics Letters. In particular, the e+e- -> hadron data compilation and combination method are now described in detail, to avoid references to unpublished material. A more realistic treatment of systematic uncertainties also improved the limit slightly
Phys.Lett.B594:23-34,2004
10.1016/j.physletb.2004.04.063
CERN-PH-EP/2004-006
hep-ph
null
The e+e- -> hadron cross section data from PEP, PETRA, TRISTAN, SLC and LEP, at centre-of-mass energies between 20 to 209 GeV, are analysed to search for the production of a pair of light sbottoms decaying hadronically via R-parity-violating couplings. This analysis allows the 95%C.L. exclusion of such a particle if its mass is below 7.5 GeV/c2. The light sbottom mass window is closed.
[ { "created": "Mon, 15 Mar 2004 10:45:33 GMT", "version": "v1" }, { "created": "Thu, 29 Apr 2004 08:10:43 GMT", "version": "v2" } ]
2008-11-26
[ [ "Janot", "Patrick", "" ] ]
The e+e- -> hadron cross section data from PEP, PETRA, TRISTAN, SLC and LEP, at centre-of-mass energies between 20 to 209 GeV, are analysed to search for the production of a pair of light sbottoms decaying hadronically via R-parity-violating couplings. This analysis allows the 95%C.L. exclusion of such a particle if its mass is below 7.5 GeV/c2. The light sbottom mass window is closed.
2311.14571
Peter Meinzinger
Peter Meinzinger and Frank Krauss
Hadron-Level NLO predictions for QCD Observables in Photo-Production at the Electron-Ion Collider
6 pages, 4 figures
null
null
IPPP/23/70
hep-ph
http://creativecommons.org/licenses/by/4.0/
We present the first next-to leading order accurate hadron-level predictions for inclusive QCD and jet observables in photo-production for the upcoming electron--ion collider.
[ { "created": "Fri, 24 Nov 2023 15:59:14 GMT", "version": "v1" } ]
2024-07-03
[ [ "Meinzinger", "Peter", "" ], [ "Krauss", "Frank", "" ] ]
We present the first next-to leading order accurate hadron-level predictions for inclusive QCD and jet observables in photo-production for the upcoming electron--ion collider.
1405.6720
Ben Stefanek
Yang Bai and Ben A. Stefanek
Natural Milli-Charged Inflation
5 pages, 3 figures
Phys. Rev. D 91, 096012 (2015)
10.1103/PhysRevD.91.096012
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct a natural inflation model with the inflaton as a linear combination of the fifth components of Abelian gauge fields in a five-dimensional theory. A seesaw mechanism is introduced to provide a natural milli-charge for matter fields under one combination of the gauge symmetries. As a result, the effective decay constant of the inflaton field can be above the Planck scale with all scales in the model below the Planck scale. Our model predicts a tensor-to-scalar ratio r between 0.033 and 0.125 for sixty e-folds and a reheating temperature of a few 10^11 GeV.
[ { "created": "Mon, 26 May 2014 20:00:16 GMT", "version": "v1" } ]
2015-06-03
[ [ "Bai", "Yang", "" ], [ "Stefanek", "Ben A.", "" ] ]
We construct a natural inflation model with the inflaton as a linear combination of the fifth components of Abelian gauge fields in a five-dimensional theory. A seesaw mechanism is introduced to provide a natural milli-charge for matter fields under one combination of the gauge symmetries. As a result, the effective decay constant of the inflaton field can be above the Planck scale with all scales in the model below the Planck scale. Our model predicts a tensor-to-scalar ratio r between 0.033 and 0.125 for sixty e-folds and a reheating temperature of a few 10^11 GeV.
2111.13917
Xu-Chang Zheng
Ze-Yang Zhang, Xu-Chang Zheng, Xing-Gang Wu
Production of the $B_c$ meson at the CEPC
8 pages, 8 figures
Eur. Phys. J. C 82, 246 (2022)
10.1140/epjc/s10052-022-10212-4
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this paper, we make a detailed study on the production of the $B_c$, $B_c^*$, $B_c(2\,^1S_0)$, and $B^*_c(2\,^3S_1)$ mesons via the three planned running modes ($Z$, $W$, and $H$) at the future Circular Electron-Positron Collider (CEPC). The fragmentation-function and full nonrelativistic QCD approaches are adopted to calculate the production cross sections. Considering the excited states shall decay to the ground $B_c$ state (e.g. $1^1S_0$-state) with almost $100\%$ probability, our numerical results show that up to next-to-leading order QCD corrections, there are about $1.4\times 10^8$ $B_c$ events to be accumulated via the $Z$ mode ($\sqrt{s}=m_{_Z}$) of the CEPC, but only about $1.6\times 10^4$ and $1.1\times 10^4$ $B_c$ events to be accumulated via the $W$ ($\sqrt{s}=160\,{\rm GeV}$) and $H$ ($\sqrt{s}=240\,{\rm GeV}$) modes, respectively. Since the $Z$ mode is the best mode among the three planned modes of the CEPC for studying the production of the $B_c$, $B_c^*$, $B_c(2\,^1S_0)$, and $B^*_c(2\,^3S_1)$ mesons and the differential distributions of these mesons may be measured precisely at this mode, we further present the differential cross sections $d\sigma/(dz\,d{\rm cos}\theta)$ and $d\sigma/dz$ via the $Z$ mode of the CEPC.
[ { "created": "Sat, 27 Nov 2021 15:00:14 GMT", "version": "v1" }, { "created": "Tue, 22 Mar 2022 13:41:30 GMT", "version": "v2" } ]
2022-03-23
[ [ "Zhang", "Ze-Yang", "" ], [ "Zheng", "Xu-Chang", "" ], [ "Wu", "Xing-Gang", "" ] ]
In this paper, we make a detailed study on the production of the $B_c$, $B_c^*$, $B_c(2\,^1S_0)$, and $B^*_c(2\,^3S_1)$ mesons via the three planned running modes ($Z$, $W$, and $H$) at the future Circular Electron-Positron Collider (CEPC). The fragmentation-function and full nonrelativistic QCD approaches are adopted to calculate the production cross sections. Considering the excited states shall decay to the ground $B_c$ state (e.g. $1^1S_0$-state) with almost $100\%$ probability, our numerical results show that up to next-to-leading order QCD corrections, there are about $1.4\times 10^8$ $B_c$ events to be accumulated via the $Z$ mode ($\sqrt{s}=m_{_Z}$) of the CEPC, but only about $1.6\times 10^4$ and $1.1\times 10^4$ $B_c$ events to be accumulated via the $W$ ($\sqrt{s}=160\,{\rm GeV}$) and $H$ ($\sqrt{s}=240\,{\rm GeV}$) modes, respectively. Since the $Z$ mode is the best mode among the three planned modes of the CEPC for studying the production of the $B_c$, $B_c^*$, $B_c(2\,^1S_0)$, and $B^*_c(2\,^3S_1)$ mesons and the differential distributions of these mesons may be measured precisely at this mode, we further present the differential cross sections $d\sigma/(dz\,d{\rm cos}\theta)$ and $d\sigma/dz$ via the $Z$ mode of the CEPC.
hep-ph/0611015
Shufang Su
Hock-Seng Goh, Shufang Su
Phenomenology of The Left-Right Twin Higgs Model
41 pages, version appears in PRD
Phys.Rev.D75:075010,2007
10.1103/PhysRevD.75.075010
null
hep-ph
null
The twin Higgs mechanism has recently been proposed to solve the little hierarchy problem. We study the implementation of the twin Higgs mechanism in left-right models. At TeV scale, heavy quark and gauge bosons appear, with rich collider phenomenology. In addition, there are extra Higgses, some of which couple to both the Standard Model fermion sector and the gauge sector, while others couple to the gauge bosons only. We present the particle spectrum, and study the general features of the collider phenomenology of this class of model at the Large Hadron Collider.
[ { "created": "Thu, 2 Nov 2006 20:45:51 GMT", "version": "v1" }, { "created": "Mon, 30 Apr 2007 20:52:27 GMT", "version": "v2" } ]
2008-11-26
[ [ "Goh", "Hock-Seng", "" ], [ "Su", "Shufang", "" ] ]
The twin Higgs mechanism has recently been proposed to solve the little hierarchy problem. We study the implementation of the twin Higgs mechanism in left-right models. At TeV scale, heavy quark and gauge bosons appear, with rich collider phenomenology. In addition, there are extra Higgses, some of which couple to both the Standard Model fermion sector and the gauge sector, while others couple to the gauge bosons only. We present the particle spectrum, and study the general features of the collider phenomenology of this class of model at the Large Hadron Collider.
1608.01509
Laura Reina
Jorge de Blas, Marco Ciuchini, Enrico Franco, Satoshi Mishima, Maurizio Pierini, Laura Reina, Luca Silvestrini
Electroweak precision observables and Higgs-boson signal strengths in the Standard Model and beyond: present and future
34 pages, 30 figures, 23 tables
null
10.1007/JHEP12(2016)135
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present results from a state-of-the-art fit of electroweak precision observables and Higgs-boson signal-strength measurements performed using 7 and 8 TeV data from the Large Hadron Collider. Based on the HEPfit package, our study updates the traditional fit of electroweak precision observables and extends it to include Higgs-boson measurements. As a result we obtain constraints on new physics corrections to both electroweak observables and Higgs-boson couplings. We present the projected accuracy of the fit taking into account the expected sensitivities at future colliders.
[ { "created": "Thu, 4 Aug 2016 12:24:53 GMT", "version": "v1" } ]
2017-02-01
[ [ "de Blas", "Jorge", "" ], [ "Ciuchini", "Marco", "" ], [ "Franco", "Enrico", "" ], [ "Mishima", "Satoshi", "" ], [ "Pierini", "Maurizio", "" ], [ "Reina", "Laura", "" ], [ "Silvestrini", "Luca", "" ] ]
We present results from a state-of-the-art fit of electroweak precision observables and Higgs-boson signal-strength measurements performed using 7 and 8 TeV data from the Large Hadron Collider. Based on the HEPfit package, our study updates the traditional fit of electroweak precision observables and extends it to include Higgs-boson measurements. As a result we obtain constraints on new physics corrections to both electroweak observables and Higgs-boson couplings. We present the projected accuracy of the fit taking into account the expected sensitivities at future colliders.
2205.05497
Adam Bzdak
Micha{\l} Barej, Adam Bzdak
Factorial cumulants from short-range correlations and global baryon number conservation
18 pages, 3 figures
null
10.1103/PhysRevC.106.024904
null
hep-ph hep-ex nucl-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
We calculate the baryon factorial cumulants assuming arbitrary short-range correlations and the global baryon number conservation. The general factorial cumulant generating function is derived. Various relations between factorial cumulants subjected to baryon number conservation and the factorial cumulants without this constraint are presented. We observe that for $n$-th factorial cumulant, the short-range correlations of more than $n$ particles are suppressed with the increasing number of particles. The recently published [1] relations between the cumulants in a finite acceptance with global baryon conservation and the grand-canonical susceptibilities are reproduced.
[ { "created": "Wed, 11 May 2022 13:39:02 GMT", "version": "v1" } ]
2022-09-14
[ [ "Barej", "Michał", "" ], [ "Bzdak", "Adam", "" ] ]
We calculate the baryon factorial cumulants assuming arbitrary short-range correlations and the global baryon number conservation. The general factorial cumulant generating function is derived. Various relations between factorial cumulants subjected to baryon number conservation and the factorial cumulants without this constraint are presented. We observe that for $n$-th factorial cumulant, the short-range correlations of more than $n$ particles are suppressed with the increasing number of particles. The recently published [1] relations between the cumulants in a finite acceptance with global baryon conservation and the grand-canonical susceptibilities are reproduced.
1104.5132
Tomohiko Tanabe
Ryo Yonamine, Katsumasa Ikematsu, Tomohiko Tanabe, Keisuke Fujii, Yuichiro Kiyo, Yukinari Sumino, and Hiroshi Yokoya
Measuring the top Yukawa coupling at the ILC at sqrt(s) = 500 GeV
9 pages, 6 figures, to be submitted to Phys. Rev. D
Phys.Rev.D84:014033,2011
10.1103/PhysRevD.84.014033
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We report on the feasibility of the direct measurement of the top Yukawa coupling g_t at the International Linear Collider (ILC) during its first phase of operation with a center-of-mass energy of 500 GeV. The signal and background models incorporate the non-relativistic QCD corrections which enhance the production cross section near the t-tbar threshold. The e+e- -> t tbar H signal is reconstructed in the 6-jet + lepton and the 8-jet modes. The results from the two channels are combined. The background processes considered are e+e- -> t bbar W- / tbar b W+ (which includes e+e- -> t tbar), e+e- -> t tbar Z, and e+e- -> t tbar g* -> t tbar b bar. We use a realistic fast Monte-Carlo detector simulation. Signal events are selected using event shape variables, through jet clustering, and by identifying heavy flavor jets. Assuming a Higgs mass of 120 GeV, polarized electron and positron beams with (Pe-,Pe+) = (-0.8,+0.3), and an integrated luminosity of 1 ab-1, we estimate that the e+e- -> t tbar H events can be seen with a statistical significance of 5.2 sigma, corresponding to the relative top Yukawa coupling measurement accuracy of |Delta g_t / g_t| = 10%.
[ { "created": "Wed, 27 Apr 2011 13:03:40 GMT", "version": "v1" } ]
2011-08-11
[ [ "Yonamine", "Ryo", "" ], [ "Ikematsu", "Katsumasa", "" ], [ "Tanabe", "Tomohiko", "" ], [ "Fujii", "Keisuke", "" ], [ "Kiyo", "Yuichiro", "" ], [ "Sumino", "Yukinari", "" ], [ "Yokoya", "Hiroshi", "" ] ]
We report on the feasibility of the direct measurement of the top Yukawa coupling g_t at the International Linear Collider (ILC) during its first phase of operation with a center-of-mass energy of 500 GeV. The signal and background models incorporate the non-relativistic QCD corrections which enhance the production cross section near the t-tbar threshold. The e+e- -> t tbar H signal is reconstructed in the 6-jet + lepton and the 8-jet modes. The results from the two channels are combined. The background processes considered are e+e- -> t bbar W- / tbar b W+ (which includes e+e- -> t tbar), e+e- -> t tbar Z, and e+e- -> t tbar g* -> t tbar b bar. We use a realistic fast Monte-Carlo detector simulation. Signal events are selected using event shape variables, through jet clustering, and by identifying heavy flavor jets. Assuming a Higgs mass of 120 GeV, polarized electron and positron beams with (Pe-,Pe+) = (-0.8,+0.3), and an integrated luminosity of 1 ab-1, we estimate that the e+e- -> t tbar H events can be seen with a statistical significance of 5.2 sigma, corresponding to the relative top Yukawa coupling measurement accuracy of |Delta g_t / g_t| = 10%.
hep-ph/9709490
Bas Tausk
A. Frink, J. G. K\"orner and J. B. Tausk
Massive Two-Loop Integrals and Higgs Physics
Latex, 26 pages, 18 postscript figures included with epsfig, uses a4wide.sty. Invited talks given by J. G. K\"orner at the Workshop 'The Higgs Puzzle', Ringberg, Germany, Dec. 1996 and at the meeting 'Tests of Electroweak Symmetry Breaking', Ouranopoulis, Greece, May 1997; to be published in the Ouranopoulis proceedings. Comments on on ref.[19] corrected, and other minor revisions
null
null
MZ-TH/97-32
hep-ph
null
We describe in some detail the present features of an automatic loop calculation program as well as the integration techniques that go into it. The program, called XLOOPS 1.0, allows one to calculate massive one- and two-loop Feynman diagrams in the Standard Model including their tensor structure. UV divergences in UV divergent integrals are explicitly computed in dimensional regularization. One-loop integrals are calculated analytically in d \neq 4 dimensions whereas two-loop integrals are reduced to two-fold integral representations which the program evaluates numerically. We discuss Higgs decay at the two-loop level as a first application of the novel integration techniques that are incorporated into XLOOPS.
[ { "created": "Mon, 29 Sep 1997 14:16:04 GMT", "version": "v1" }, { "created": "Mon, 20 Oct 1997 16:32:36 GMT", "version": "v2" } ]
2009-09-25
[ [ "Frink", "A.", "" ], [ "Körner", "J. G.", "" ], [ "Tausk", "J. B.", "" ] ]
We describe in some detail the present features of an automatic loop calculation program as well as the integration techniques that go into it. The program, called XLOOPS 1.0, allows one to calculate massive one- and two-loop Feynman diagrams in the Standard Model including their tensor structure. UV divergences in UV divergent integrals are explicitly computed in dimensional regularization. One-loop integrals are calculated analytically in d \neq 4 dimensions whereas two-loop integrals are reduced to two-fold integral representations which the program evaluates numerically. We discuss Higgs decay at the two-loop level as a first application of the novel integration techniques that are incorporated into XLOOPS.
1606.07737
Emanuele Mereghetti
Michael Fickinger, Sean Fleming, Chul Kim and Emanuele Mereghetti
Effective field theory approach to heavy quark fragmentation
62 pages. python code for the DGLAP evolution of the fragmentation function attached
null
10.1007/JHEP11(2016)095
LA-UR-16-24386
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Using an approach based on Soft Collinear Effective Theory (SCET) and Heavy Quark Effective Theory (HQET) we determine the $b$-quark fragmentation function from electron-positron annihilation data at the $Z$-boson peak at next-to-next-to leading order, with next-to-next-to leading log resummation of DGLAP logarithms, and next-to-next-to-next-to leading log resummation of endpoint logarithms. This analysis improves, by one order, the previous extraction of the $b$-quark fragmentation function. We find that while the addition of the next order in the calculation does not much shift the extracted form of the fragmentation function, it does reduce theoretical errors indicating that the expansion is converging. Using an approach based on effective field theory allows us to systematically control theoretical errors. While the fits of theory to data are generally good, the fits seem to be hinting that higher order correction from HQET may be needed to explain the $b$-quark fragmentation function at smaller values of momentum fraction.
[ { "created": "Fri, 24 Jun 2016 16:03:14 GMT", "version": "v1" }, { "created": "Mon, 5 Dec 2016 21:55:49 GMT", "version": "v2" } ]
2016-12-21
[ [ "Fickinger", "Michael", "" ], [ "Fleming", "Sean", "" ], [ "Kim", "Chul", "" ], [ "Mereghetti", "Emanuele", "" ] ]
Using an approach based on Soft Collinear Effective Theory (SCET) and Heavy Quark Effective Theory (HQET) we determine the $b$-quark fragmentation function from electron-positron annihilation data at the $Z$-boson peak at next-to-next-to leading order, with next-to-next-to leading log resummation of DGLAP logarithms, and next-to-next-to-next-to leading log resummation of endpoint logarithms. This analysis improves, by one order, the previous extraction of the $b$-quark fragmentation function. We find that while the addition of the next order in the calculation does not much shift the extracted form of the fragmentation function, it does reduce theoretical errors indicating that the expansion is converging. Using an approach based on effective field theory allows us to systematically control theoretical errors. While the fits of theory to data are generally good, the fits seem to be hinting that higher order correction from HQET may be needed to explain the $b$-quark fragmentation function at smaller values of momentum fraction.
1609.07198
Chian-Shu Chen
Chian-Shu Chen, Guey-Lin Lin, Yen-Hsun Lin, and Fanrong Xu
The 17 MeV Anomaly in Beryllium Decays and $U(1)$ Portal to Dark Matter
13 pages, 3 figures, published version
Int.J.Mod.Phys. A32 (2017) no.31, 1750178
10.1142/S0217751X17501780
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The experiment of Krasznahorkay \textit{et al} observed the transition of a $\rm{^{8}Be}$ excited state to its ground state and accompanied by an emission of $e^{+}e^{-}$ pair with 17 MeV invariant mass. This 6.8$\sigma$ anomaly can be fitted by a new light gauge boson. We consider the new particle as a $U(1)$ gauge boson, $Z'$, which plays as a portal linking dark sector and visible sector. In particular, we study the new $U(1)$ gauge symmetry as a hidden or non-hidden group separately. The generic hidden $U(1)$ model, referred to as dark $Z$ model, is excluded by imposing various experimental constraints. On the other hand, a non-hidden $Z'$ is allowed due to additional interactions between $Z'$ and Standard Model fermions. We also study the implication of the dark matter direct search on such a scenario. We found the search for the DM-nucleon scattering excludes the range of DM mass above 500 MeV. However, the DM-electron scattering for MeV-scale DM is still allowed by current constraints for non-hidden $U(1)$ models. It is possible to test the underlying $U(1)$ portal model by the future Si and Ge detectors with $5e^{-}$ threshold charges.
[ { "created": "Fri, 23 Sep 2016 00:51:59 GMT", "version": "v1" }, { "created": "Fri, 13 Apr 2018 13:09:10 GMT", "version": "v2" } ]
2018-04-16
[ [ "Chen", "Chian-Shu", "" ], [ "Lin", "Guey-Lin", "" ], [ "Lin", "Yen-Hsun", "" ], [ "Xu", "Fanrong", "" ] ]
The experiment of Krasznahorkay \textit{et al} observed the transition of a $\rm{^{8}Be}$ excited state to its ground state and accompanied by an emission of $e^{+}e^{-}$ pair with 17 MeV invariant mass. This 6.8$\sigma$ anomaly can be fitted by a new light gauge boson. We consider the new particle as a $U(1)$ gauge boson, $Z'$, which plays as a portal linking dark sector and visible sector. In particular, we study the new $U(1)$ gauge symmetry as a hidden or non-hidden group separately. The generic hidden $U(1)$ model, referred to as dark $Z$ model, is excluded by imposing various experimental constraints. On the other hand, a non-hidden $Z'$ is allowed due to additional interactions between $Z'$ and Standard Model fermions. We also study the implication of the dark matter direct search on such a scenario. We found the search for the DM-nucleon scattering excludes the range of DM mass above 500 MeV. However, the DM-electron scattering for MeV-scale DM is still allowed by current constraints for non-hidden $U(1)$ models. It is possible to test the underlying $U(1)$ portal model by the future Si and Ge detectors with $5e^{-}$ threshold charges.
2012.15760
Tom\'a\v{s} Husek
Tom\'a\v{s} Husek (Charles U.), Kevin Mons\'alvez-Pozo, Jorge Portol\'es (IFIC, Valencia)
Lepton-flavour violation in hadronic tau decays and $\ell$-$\tau$ conversion in nuclei
6 pages, 5 figures, 2 tables; contribution to the proceedings of the 40th International Conference on High Energy Physics (ICHEP2020)
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Within the Standard Model Effective Field Theory framework, with operators up to dimension 6, we perform a model-independent analysis of the lepton-flavour-violating processes involving tau leptons. Namely, we study hadronic tau decays and $\ell$-$\tau$ conversion in nuclei ($\ell=e,\mu$). Based on available experimental limits, we establish constraints on the Wilson coefficients of the operators contributing to these processes. The related information from Belle II and foreseen future experiments can be easily incorporated into the resulting framework.
[ { "created": "Thu, 31 Dec 2020 17:35:54 GMT", "version": "v1" } ]
2021-01-01
[ [ "Husek", "Tomáš", "", "Charles U." ], [ "Monsálvez-Pozo", "Kevin", "", "IFIC, Valencia" ], [ "Portolés", "Jorge", "", "IFIC, Valencia" ] ]
Within the Standard Model Effective Field Theory framework, with operators up to dimension 6, we perform a model-independent analysis of the lepton-flavour-violating processes involving tau leptons. Namely, we study hadronic tau decays and $\ell$-$\tau$ conversion in nuclei ($\ell=e,\mu$). Based on available experimental limits, we establish constraints on the Wilson coefficients of the operators contributing to these processes. The related information from Belle II and foreseen future experiments can be easily incorporated into the resulting framework.
hep-ph/0506203
Lev Okun
A.D. Dolgov, O.V. Lychkovskiy, A.A. Mamonov, L.B. Okun, M.G. Schepkin
Neutrino wave function and oscillation suppression
7 pages
Eur.Phys.J.C44:431-434,2005
10.1140/epjc/s2005-02369-7
null
hep-ph
null
We consider a thought experiment, in which a neutrino is produced by an electron on a nucleus in a crystal. The wave function of the oscillating neutrino is calculated assuming that the electron is described by a wave packet. If the electron is relativistic and the spatial size of its wave packet is much larger than the size of the crystal cell, then the wave packet of the produced neutrino has essentially the same size as the wave packet of the electron. We investigate the suppression of neutrino oscillations at large distances caused by two mechanisms: 1) spatial separation of wave packets corresponding to different neutrino masses; 2) neutrino energy dispersion for given neutrino mass eigenstates. We resolve contributions of these two mechanisms.
[ { "created": "Tue, 21 Jun 2005 14:33:23 GMT", "version": "v1" }, { "created": "Wed, 6 Jul 2005 20:00:08 GMT", "version": "v2" } ]
2009-01-07
[ [ "Dolgov", "A. D.", "" ], [ "Lychkovskiy", "O. V.", "" ], [ "Mamonov", "A. A.", "" ], [ "Okun", "L. B.", "" ], [ "Schepkin", "M. G.", "" ] ]
We consider a thought experiment, in which a neutrino is produced by an electron on a nucleus in a crystal. The wave function of the oscillating neutrino is calculated assuming that the electron is described by a wave packet. If the electron is relativistic and the spatial size of its wave packet is much larger than the size of the crystal cell, then the wave packet of the produced neutrino has essentially the same size as the wave packet of the electron. We investigate the suppression of neutrino oscillations at large distances caused by two mechanisms: 1) spatial separation of wave packets corresponding to different neutrino masses; 2) neutrino energy dispersion for given neutrino mass eigenstates. We resolve contributions of these two mechanisms.
1710.07442
Brett McInnes
Brett McInnes
Jet Quenching in The Most Vortical Fluid: A Holographic Approach
21 pages, no figures
null
null
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The STAR collaboration at the RHIC facility has recently announced the exciting discovery of direct evidence for extremely large vorticity in the Quark-Gluon Plasma generated in peripheral collisions, seen in the form of global polarization of $\Lambda$ and $\bar{\Lambda}$ hyperons. This prompts the question: does this vorticity have any effect on other observed phenomena, such as jet quenching? Using a simple gauge-gravity model, we suggest that such an effect may be detectable, in data from near-future experiments, as a reduction in the jet quenching parameter. This is predicted to be most prominent in collisions corresponding to a narrow range of centralities around $10 \%$. The relative reduction (compared to collisions at zero or, alternatively, large centrality) is predicted to behave in an unexpected and characteristic manner: the model suggests that it is independent of the impact energy.
[ { "created": "Fri, 20 Oct 2017 07:42:30 GMT", "version": "v1" } ]
2017-10-23
[ [ "McInnes", "Brett", "" ] ]
The STAR collaboration at the RHIC facility has recently announced the exciting discovery of direct evidence for extremely large vorticity in the Quark-Gluon Plasma generated in peripheral collisions, seen in the form of global polarization of $\Lambda$ and $\bar{\Lambda}$ hyperons. This prompts the question: does this vorticity have any effect on other observed phenomena, such as jet quenching? Using a simple gauge-gravity model, we suggest that such an effect may be detectable, in data from near-future experiments, as a reduction in the jet quenching parameter. This is predicted to be most prominent in collisions corresponding to a narrow range of centralities around $10 \%$. The relative reduction (compared to collisions at zero or, alternatively, large centrality) is predicted to behave in an unexpected and characteristic manner: the model suggests that it is independent of the impact energy.
0905.3220
Anjishnu Sarkar Dr.
Sudhanwa Patra, Anjishnu Sarkar, Utpal Sarkar and Urjit Yajnik
Spontaneous Parity Violation in a Supersymmetric Left-Right Symmetric Model
12 pages, revtex4
Phys.Lett.B679:386-389,2009
10.1016/j.physletb.2009.07.059
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a novel implementation of spontaneous parity breaking in supersymmetric left-right symmetric model, avoiding some of the problems encountered in previous studies. This implementation includes a bitriplet and a singlet, in addition to the bidoublets which extend the Higgs sector of the Minimal Supersymmetric Standard Model (MSSM). The supersymmetric vacua of this theory are shown to lead generically to spontaneous violation of parity, while preserving R parity. The model is shown to reproduce the see-saw relation for vacuum expectation values, $v_L v_R \approx m_{EW}^2$ relating the new mass scales $v_L$, $v_R$ to the electroweak scale $m_{EW}$, just as in the non-supersymmetric version. The scale $v_R$ determines the mass scale of heavy majorana neutrinos, which gets related to the obeserved neutrino masses through type II see-saw relation.
[ { "created": "Wed, 20 May 2009 10:42:50 GMT", "version": "v1" } ]
2010-05-28
[ [ "Patra", "Sudhanwa", "" ], [ "Sarkar", "Anjishnu", "" ], [ "Sarkar", "Utpal", "" ], [ "Yajnik", "Urjit", "" ] ]
We propose a novel implementation of spontaneous parity breaking in supersymmetric left-right symmetric model, avoiding some of the problems encountered in previous studies. This implementation includes a bitriplet and a singlet, in addition to the bidoublets which extend the Higgs sector of the Minimal Supersymmetric Standard Model (MSSM). The supersymmetric vacua of this theory are shown to lead generically to spontaneous violation of parity, while preserving R parity. The model is shown to reproduce the see-saw relation for vacuum expectation values, $v_L v_R \approx m_{EW}^2$ relating the new mass scales $v_L$, $v_R$ to the electroweak scale $m_{EW}$, just as in the non-supersymmetric version. The scale $v_R$ determines the mass scale of heavy majorana neutrinos, which gets related to the obeserved neutrino masses through type II see-saw relation.
hep-ph/9608381
Agustin Nieto
Agustin Nieto (Ohio State University)
High-Temperature Thermodynamics of QCD
5 pages. Invited talk presented at Workshop on QCD in Paris, June 1996
null
null
OHSTPY-HEP-T-96-020
hep-ph
null
Effective-field-theory methods are used to study the high T limit of QCD. These methods unravel the contributions to the free energy of QCD at high temperature from the scales T, gT, and g^2 T. The free energy is explicitly computed to order g^5. Implications for the application of perturbative QCD to the quark-gluon plasma are also discussed.
[ { "created": "Tue, 20 Aug 1996 20:28:17 GMT", "version": "v1" } ]
2016-09-06
[ [ "Nieto", "Agustin", "", "Ohio State University" ] ]
Effective-field-theory methods are used to study the high T limit of QCD. These methods unravel the contributions to the free energy of QCD at high temperature from the scales T, gT, and g^2 T. The free energy is explicitly computed to order g^5. Implications for the application of perturbative QCD to the quark-gluon plasma are also discussed.
hep-ph/0507314
Hendrik van Hees
L. Grandchamp, S. Lumpkins, D. Sun, H. van Hees, R. Rapp
Bottomonium Production at RHIC and LHC
16 Pages, 21 figures, 1 table v2: Manuscript reorganized, several sections moved to appendices, additional comments included, contents unchanged
Phys.Rev.C73:064906,2006
10.1103/PhysRevC.73.064906
LBNL-58479
hep-ph nucl-ex nucl-th
null
Properties of bottomonia (Upsilon, chi_b and Upsilon') in the Quark-Gluon Plasma (QGP) are investigated by assessing inelastic reaction rates and their interplay with open-bottom states (b-quarks or B-mesons) and color-screening. The latter leads to vanishing quarkonium binding energies at sufficiently high temperatures (close to the dissolution point), which, in particular, renders standard gluo-dissociation, g+Upsilon -> b + b-bar, inefficient due to a substantial reduction in final-state phase space. This problem is overcome by invoking a "quasifree" destruction mechanism, g,q,q-bar + Upsilon -> g,q,q-bar + b + b-bar, as previously introduced for charmonia. The pertinent reaction rates are implemented into a kinetic theory framework to evaluate the time evolution of bottomonia in heavy-ion reactions at RHIC and LHC within an expanding fireball model. While bottom quarks are assumed to be exclusively produced in primordial nucleon-nucleon collisions, their thermal relaxation times in the QGP, which importantly figure into Upsilon-formation rates, are estimated according to a recent Fokker-Planck treatment. Predictions for the centrality dependence of Upsilon production are given for upcoming experiments at RHIC and LHC. At both energies, Upsilon suppression turns out to be the prevalent effect.
[ { "created": "Wed, 27 Jul 2005 19:48:52 GMT", "version": "v1" }, { "created": "Fri, 17 Feb 2006 17:39:58 GMT", "version": "v2" } ]
2008-11-26
[ [ "Grandchamp", "L.", "" ], [ "Lumpkins", "S.", "" ], [ "Sun", "D.", "" ], [ "van Hees", "H.", "" ], [ "Rapp", "R.", "" ] ]
Properties of bottomonia (Upsilon, chi_b and Upsilon') in the Quark-Gluon Plasma (QGP) are investigated by assessing inelastic reaction rates and their interplay with open-bottom states (b-quarks or B-mesons) and color-screening. The latter leads to vanishing quarkonium binding energies at sufficiently high temperatures (close to the dissolution point), which, in particular, renders standard gluo-dissociation, g+Upsilon -> b + b-bar, inefficient due to a substantial reduction in final-state phase space. This problem is overcome by invoking a "quasifree" destruction mechanism, g,q,q-bar + Upsilon -> g,q,q-bar + b + b-bar, as previously introduced for charmonia. The pertinent reaction rates are implemented into a kinetic theory framework to evaluate the time evolution of bottomonia in heavy-ion reactions at RHIC and LHC within an expanding fireball model. While bottom quarks are assumed to be exclusively produced in primordial nucleon-nucleon collisions, their thermal relaxation times in the QGP, which importantly figure into Upsilon-formation rates, are estimated according to a recent Fokker-Planck treatment. Predictions for the centrality dependence of Upsilon production are given for upcoming experiments at RHIC and LHC. At both energies, Upsilon suppression turns out to be the prevalent effect.
hep-ph/9805442
Santi Peris
S. Peris (UAB, Barcelona), M. Perrottet (CPT, Marseille), E. de Rafael (CPT, Marseille)
Matching Long and Short Distances in Large-Nc QCD
35 pages, 9 figures, LaTeX. Added a couple of references
JHEP9805:011,1998
10.1088/1126-6708/1998/05/011
CPT-97/P.3638, UAB-FT-443
hep-ph hep-th nucl-th
null
It is shown, with the example of the experimentally known Adler function, that there is no matching in the intermediate region between the two asymptotic regimes described by perturbative QCD (for the very short-distances) and by chiral perturbation theory (for the very long-distances). We then propose to consider an approximation of large-Nc QCD which consists in restricting the hadronic spectrum in the channels with J^P quantum numbers 0^-, 1^-, 0^+ and 1^+ to the lightest state and treating the rest of the narrow states as a perturbative QCD continuum; the onset of this continuum being fixed by consistency constraints from the operator product expansion. We show how to construct the low-energy effective Lagrangian which describes this approximation. The number of free parameters in the resulting effective Lagrangian can be reduced, in the chiral limit where the light quark masses are set to zero, to just one mass scale and one dimensionless constant to all orders in chiral perturbation theory. A comparison of the corresponding predictions, to O(p^4) in the chiral expansion, with the phenomenologically known couplings is also made.
[ { "created": "Mon, 25 May 1998 13:41:31 GMT", "version": "v1" }, { "created": "Thu, 2 Jul 1998 13:55:58 GMT", "version": "v2" } ]
2009-10-31
[ [ "Peris", "S.", "", "UAB, Barcelona" ], [ "Perrottet", "M.", "", "CPT, Marseille" ], [ "de Rafael", "E.", "", "CPT, Marseille" ] ]
It is shown, with the example of the experimentally known Adler function, that there is no matching in the intermediate region between the two asymptotic regimes described by perturbative QCD (for the very short-distances) and by chiral perturbation theory (for the very long-distances). We then propose to consider an approximation of large-Nc QCD which consists in restricting the hadronic spectrum in the channels with J^P quantum numbers 0^-, 1^-, 0^+ and 1^+ to the lightest state and treating the rest of the narrow states as a perturbative QCD continuum; the onset of this continuum being fixed by consistency constraints from the operator product expansion. We show how to construct the low-energy effective Lagrangian which describes this approximation. The number of free parameters in the resulting effective Lagrangian can be reduced, in the chiral limit where the light quark masses are set to zero, to just one mass scale and one dimensionless constant to all orders in chiral perturbation theory. A comparison of the corresponding predictions, to O(p^4) in the chiral expansion, with the phenomenologically known couplings is also made.
hep-ph/9908461
Markus H. Thoma
Munshi G. Mustafa, Andreas Sch"afer, Markus H. Thoma
Non-Perturbative Dilepton Production from a Quark-Gluon Plasma
16 pages, REVTEX, 8 PostScript figures
Phys.Rev. C61 (2000) 024902
10.1103/PhysRevC.61.024902
null
hep-ph nucl-th
null
The dilepton production rate from the quark-gluon plasma is calculated from the imaginary part of the photon self energy using a quark propagator that contains the gluon condensate. The low mass dilepton rate obtained in this way exhibits interesting structures (peaks and gaps), which might be observable at RHIC and LHC.
[ { "created": "Wed, 25 Aug 1999 13:30:55 GMT", "version": "v1" } ]
2009-10-31
[ [ "Mustafa", "Munshi G.", "" ], [ "Sch\"afer", "Andreas", "" ], [ "Thoma", "Markus H.", "" ] ]
The dilepton production rate from the quark-gluon plasma is calculated from the imaginary part of the photon self energy using a quark propagator that contains the gluon condensate. The low mass dilepton rate obtained in this way exhibits interesting structures (peaks and gaps), which might be observable at RHIC and LHC.
1510.07194
Cheuk-Yin Wong
Cheuk-Yin Wong
Event-by-Event Study of Space-Time Dynamics in Flux-Tube Fragmentation
15 pages, 4 figures
Journal pf Physics G 44, 075102 (2017)
10.1088/1361-6471/aa6fdb
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the semi-classical description of the flux-tube fragmentation process for hadron production and hadronization in high-energy $e^+e^-$ annihilations and $pp$ collisions, the rapidity-space-time ordering and the local conservation laws of charge, flavor, and momentum provide a set of powerful tools that may allow the reconstruction of the space-time dynamics of quarks and mesons in exclusive measurements of produced hadrons, on an event-by-event basis. We propose procedures to reconstruct the space-time dynamics from event-by-event exclusive hadron data to exhibit explicitly the ordered chain of hadrons produced in a flux tube fragmentation. As a supplementary tool, we infer the average space-time coordinates of the $q$-$\bar q$ pair production vertices from the $\pi^-$ rapidity distribution data obtained by the NA61/SHINE Collaboration in $pp$ collisions at $\sqrt{s}$ = 6.3 to 17.3 GeV.
[ { "created": "Sun, 25 Oct 2015 01:03:13 GMT", "version": "v1" }, { "created": "Mon, 11 Jan 2016 16:21:10 GMT", "version": "v2" }, { "created": "Wed, 27 Apr 2016 16:59:20 GMT", "version": "v3" }, { "created": "Thu, 25 May 2017 15:38:41 GMT", "version": "v4" } ]
2017-05-26
[ [ "Wong", "Cheuk-Yin", "" ] ]
In the semi-classical description of the flux-tube fragmentation process for hadron production and hadronization in high-energy $e^+e^-$ annihilations and $pp$ collisions, the rapidity-space-time ordering and the local conservation laws of charge, flavor, and momentum provide a set of powerful tools that may allow the reconstruction of the space-time dynamics of quarks and mesons in exclusive measurements of produced hadrons, on an event-by-event basis. We propose procedures to reconstruct the space-time dynamics from event-by-event exclusive hadron data to exhibit explicitly the ordered chain of hadrons produced in a flux tube fragmentation. As a supplementary tool, we infer the average space-time coordinates of the $q$-$\bar q$ pair production vertices from the $\pi^-$ rapidity distribution data obtained by the NA61/SHINE Collaboration in $pp$ collisions at $\sqrt{s}$ = 6.3 to 17.3 GeV.
1808.07775
Jielei Zhang
Jielei Zhang, Limin Yuan
Search for vector charmonium(-like) states in $e^+e^- \rightarrow \omega\chi_{cJ}$
null
null
10.5506/APhysPolB.49.1629
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The cross sections of $e^+e^- \rightarrow \omega\chi_{cJ(J=0,1,2)}$ have been measured by BESIII. We try to search for vector charmonium(-like) states $Y(4220)$, $Y(4360)$, $\psi(4415)$ and $Y(4660)$ in the $e^+e^- \rightarrow \omega\chi_{cJ(J=0,1,2)}$ line shapes. The $\omega\chi_{c0}$ mainly comes from $Y(4220)$, $\omega\chi_{c1}$ mainly comes from $Y(4660)$ and $\omega\chi_{c2}$ mainly comes from $\psi(4415)$, maybe partly comes from $Y(4360)$ or $Y(4660)$. For the charmonium(-like) states that are not significant in the $e^+e^- \rightarrow \omega\chi_{cJ(J=0,1,2)}$ line shape, we also give the $90\%$ confidence level upper limits on the electron partial width multiplied by branching fraction. These results are helpful to study the nature of charmonium(-like) states in this energy region.
[ { "created": "Thu, 23 Aug 2018 14:26:38 GMT", "version": "v1" } ]
2018-11-14
[ [ "Zhang", "Jielei", "" ], [ "Yuan", "Limin", "" ] ]
The cross sections of $e^+e^- \rightarrow \omega\chi_{cJ(J=0,1,2)}$ have been measured by BESIII. We try to search for vector charmonium(-like) states $Y(4220)$, $Y(4360)$, $\psi(4415)$ and $Y(4660)$ in the $e^+e^- \rightarrow \omega\chi_{cJ(J=0,1,2)}$ line shapes. The $\omega\chi_{c0}$ mainly comes from $Y(4220)$, $\omega\chi_{c1}$ mainly comes from $Y(4660)$ and $\omega\chi_{c2}$ mainly comes from $\psi(4415)$, maybe partly comes from $Y(4360)$ or $Y(4660)$. For the charmonium(-like) states that are not significant in the $e^+e^- \rightarrow \omega\chi_{cJ(J=0,1,2)}$ line shape, we also give the $90\%$ confidence level upper limits on the electron partial width multiplied by branching fraction. These results are helpful to study the nature of charmonium(-like) states in this energy region.
1412.1383
Alexei Prokudin
M. Boglione, J.O. Gonzalez Hernandez, S. Melis, and A. Prokudin
A study on the interplay between perturbative QCD and CSS/TMD formalism in SIDIS processes
Two references and an appendix added, 22 pages, 11 figures
null
10.1007/JHEP02(2015)095
JLAB-THY-14-1983
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the Semi-Inclusive Deep Inelastic Scattering (SIDIS) cross section as a function of the transverse momentum, $q_T$. In order to describe it over a wide region of $q_T$, soft gluon resummation has to be performed. Here we will use the original Collins-Soper-Sterman (CSS) formalism; however, the same procedure would hold within the improved Transverse Momentum Dependent (TMD) framework. We study the matching between the region where fixed order perturbative QCD can successfully be applied and the region where soft gluon resummation is necessary. We find that the commonly used prescription of matching through the so-called Y-factor cannot be applied in the SIDIS kinematical configurations we examine. In particular, the non-perturbative component of the resummed cross section turns out to play a crucial role and should not be overlooked even at relatively high energies. Moreover, the perturbative expansion of the resummed cross section in the matching region is not as reliable as it is usually believed and its treatment requires special attention.
[ { "created": "Wed, 3 Dec 2014 16:11:52 GMT", "version": "v1" }, { "created": "Tue, 16 Dec 2014 16:26:30 GMT", "version": "v2" } ]
2015-06-23
[ [ "Boglione", "M.", "" ], [ "Hernandez", "J. O. Gonzalez", "" ], [ "Melis", "S.", "" ], [ "Prokudin", "A.", "" ] ]
We study the Semi-Inclusive Deep Inelastic Scattering (SIDIS) cross section as a function of the transverse momentum, $q_T$. In order to describe it over a wide region of $q_T$, soft gluon resummation has to be performed. Here we will use the original Collins-Soper-Sterman (CSS) formalism; however, the same procedure would hold within the improved Transverse Momentum Dependent (TMD) framework. We study the matching between the region where fixed order perturbative QCD can successfully be applied and the region where soft gluon resummation is necessary. We find that the commonly used prescription of matching through the so-called Y-factor cannot be applied in the SIDIS kinematical configurations we examine. In particular, the non-perturbative component of the resummed cross section turns out to play a crucial role and should not be overlooked even at relatively high energies. Moreover, the perturbative expansion of the resummed cross section in the matching region is not as reliable as it is usually believed and its treatment requires special attention.
hep-ph/9408245
Anne Billups
A.H. Nueller
Unitarity and the BFKL Pomeron
25 pages,report CU-TP-640
Nucl.Phys. B437 (1995) 107-126
10.1016/0550-3213(94)00480-3
null
hep-ph
null
{\narrower\smallskip High Energy onium-onium scattering is calculated as a function of impact parameter in the one and two pomeron exchange approximation. Difficulties with using the multiple scattering series to unitarize single pomeron exchange at high energy are noted. An operator formalsim which sums all numbers of pomeron exchange is given. A toy model which has a similar operator structure at high energy as QCD is presented and the S-matrix is evaluated. Estimates of the energies and impact parameters at which blackness occurs in onium-onium scattering are given. It is emphased that the problem of unitarity in high energy onium-onium scattering can be solved in a purely perturbative context, with a non-running coupling if the onium is heavy enough.\smallskip}
[ { "created": "Fri, 5 Aug 1994 18:15:41 GMT", "version": "v1" } ]
2009-10-28
[ [ "Nueller", "A. H.", "" ] ]
{\narrower\smallskip High Energy onium-onium scattering is calculated as a function of impact parameter in the one and two pomeron exchange approximation. Difficulties with using the multiple scattering series to unitarize single pomeron exchange at high energy are noted. An operator formalsim which sums all numbers of pomeron exchange is given. A toy model which has a similar operator structure at high energy as QCD is presented and the S-matrix is evaluated. Estimates of the energies and impact parameters at which blackness occurs in onium-onium scattering are given. It is emphased that the problem of unitarity in high energy onium-onium scattering can be solved in a purely perturbative context, with a non-running coupling if the onium is heavy enough.\smallskip}
1806.11059
Apostolos Pilaftsis
Vincenzo Branchina, Filippo Contino and Apostolos Pilaftsis
Protecting the Stability of the EW Vacuum from Planck-Scale Gravitational Effects
16 pages, 5 Figures, clarifications regarding the consistency of the EFT models with Swampland criteria added. To appear in Physical Review D. In memory of our esteemed colleague and friend, Maria Krawczyk
Phys. Rev. D 98, 075001 (2018)
10.1103/PhysRevD.98.075001
MAN/HEP/2018/03
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the stability of the Standard-Model Electroweak (EW) vacuum in the presence of Planck-scale suppressed operators of the type $\phi^{2n}/M^{2n-4}_{\rm P}$ that involve the Higgs field $\phi$ and could in principle be induced by quantum gravity effects. We show how minimal embeddings of the Standard Model (SM) in supergravity (SUGRA) can stabilize the EW vacuum against such operators up to very high values of the induced supersymmetry breaking scale $M_{\cal S}$, which may well be above the onset of the so-called SM metastability scale of $10^{11}$ GeV. In particular, we explicitly demonstrate how discrete $R$ symmetries could be invoked to suppress the occurrence of harmful Planck-scale operators of the form $\phi^{2n}/M^{2n-4}_{\rm P}$ to arbitrary higher powers of $n$. We analyze different scenarios of Planck-scale gravitational physics and derive lower limits on the power $n$ that is required in order to protect our EW vacuum from dangerous rapid decay. The significance of our results for theories of low-scale quantum gravity is illustrated.
[ { "created": "Thu, 28 Jun 2018 16:19:33 GMT", "version": "v1" }, { "created": "Fri, 21 Sep 2018 11:57:22 GMT", "version": "v2" } ]
2018-10-10
[ [ "Branchina", "Vincenzo", "" ], [ "Contino", "Filippo", "" ], [ "Pilaftsis", "Apostolos", "" ] ]
We investigate the stability of the Standard-Model Electroweak (EW) vacuum in the presence of Planck-scale suppressed operators of the type $\phi^{2n}/M^{2n-4}_{\rm P}$ that involve the Higgs field $\phi$ and could in principle be induced by quantum gravity effects. We show how minimal embeddings of the Standard Model (SM) in supergravity (SUGRA) can stabilize the EW vacuum against such operators up to very high values of the induced supersymmetry breaking scale $M_{\cal S}$, which may well be above the onset of the so-called SM metastability scale of $10^{11}$ GeV. In particular, we explicitly demonstrate how discrete $R$ symmetries could be invoked to suppress the occurrence of harmful Planck-scale operators of the form $\phi^{2n}/M^{2n-4}_{\rm P}$ to arbitrary higher powers of $n$. We analyze different scenarios of Planck-scale gravitational physics and derive lower limits on the power $n$ that is required in order to protect our EW vacuum from dangerous rapid decay. The significance of our results for theories of low-scale quantum gravity is illustrated.
2405.05312
Joshua Tong
Rebecca K. Leane and Joshua Tong
Optimal Celestial Bodies for Dark Matter Detection
53 pages, 13 figures
null
null
SLAC-PUB-17773
hep-ph astro-ph.EP astro-ph.HE hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A wide variety of celestial bodies have been considered as dark matter detectors. Which stands the best chance of delivering the discovery of dark matter? Which is the most powerful dark matter detector? We investigate a range of objects, including the Sun, Earth, Jupiter, Brown Dwarfs, White Dwarfs, Neutron Stars, Stellar populations, and Exoplanets. We quantify how different objects are optimal dark matter detectors in different regimes by deconstructing some of the in-built assumptions in these search sensitivities, including observation potential and particle model assumptions. We show how different objects can be expected to deliver corroborating signals. We discuss different search strategies, their opportunities and limitations, and the interplay of regimes where different celestial objects are optimal dark matter detectors.
[ { "created": "Wed, 8 May 2024 18:00:01 GMT", "version": "v1" } ]
2024-05-12
[ [ "Leane", "Rebecca K.", "" ], [ "Tong", "Joshua", "" ] ]
A wide variety of celestial bodies have been considered as dark matter detectors. Which stands the best chance of delivering the discovery of dark matter? Which is the most powerful dark matter detector? We investigate a range of objects, including the Sun, Earth, Jupiter, Brown Dwarfs, White Dwarfs, Neutron Stars, Stellar populations, and Exoplanets. We quantify how different objects are optimal dark matter detectors in different regimes by deconstructing some of the in-built assumptions in these search sensitivities, including observation potential and particle model assumptions. We show how different objects can be expected to deliver corroborating signals. We discuss different search strategies, their opportunities and limitations, and the interplay of regimes where different celestial objects are optimal dark matter detectors.
hep-ph/0201045
Dara Doyle
G.L.Kane and D.D.Doyle
CP Violation beyond the Standard Model
17 pages, LaTeX, 6 postscript figures. Uses iopart10.clo, iopart12.clo and iopart.cls. Plenary talk given at the BSM Phenomenology Workshop, Durham, UK, 6-11 May 2001. To appear in the proceedings
J.Phys.G28:345,2002
10.1088/0954-3899/28/2/312
IPPP/02/02, DCPT/02/04
hep-ph
null
In this talk a number of broad issues are raised about the origins of CP violation and how to test the ideas.
[ { "created": "Tue, 8 Jan 2002 10:51:21 GMT", "version": "v1" } ]
2008-11-26
[ [ "Kane", "G. L.", "" ], [ "Doyle", "D. D.", "" ] ]
In this talk a number of broad issues are raised about the origins of CP violation and how to test the ideas.
hep-ph/9311280
null
Su H. Lee, T. Hatsuda and G. A. Miller
Transverse Quark Distribution in Mesons - QCD Sum Rule Approach -
8 pages, Latex, Univ. of Washington preprint DOE/ER/40427-24-N93
Phys.Rev.Lett. 72 (1994) 2345-2348
10.1103/PhysRevLett.72.2345
null
hep-ph nucl-th
null
QCD sum rules are used to compute the first few moments of the mesonic quark momentum. Transverse, longitudinal and mixed transverse-longitudinal components are examined. The transverse size of the pion is shown to be dictated by the gluon condensate, even though the mass and the longitudinal distribution are dominated by the quark condensate. The implications of our results for color transparency physics and finite temperature QCD are discussed.
[ { "created": "Fri, 12 Nov 1993 00:49:11 GMT", "version": "v1" } ]
2009-10-22
[ [ "Lee", "Su H.", "" ], [ "Hatsuda", "T.", "" ], [ "Miller", "G. A.", "" ] ]
QCD sum rules are used to compute the first few moments of the mesonic quark momentum. Transverse, longitudinal and mixed transverse-longitudinal components are examined. The transverse size of the pion is shown to be dictated by the gluon condensate, even though the mass and the longitudinal distribution are dominated by the quark condensate. The implications of our results for color transparency physics and finite temperature QCD are discussed.
1804.01424
Madan Singh
Madan Singh
Implication of rephasing invariant parameters on texture specific mass matrices
arXiv admin note: text overlap with arXiv:0901.2819, arXiv:1111.5332, arXiv:1010.3839 by other authors
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the quark sector, Jarlskog rephasing invariant parameter $J_{CP}$ has important implications for the CP violation as well as phase structure of the quark mass matrices. In fact all CP violating effects in this sector are proportional to the magnitude of the imaginary part of $J_{CP}$ . With the observation of non-zero and large "reactor mixing angle", it is widely believed that CP might be violated in the leptonic sector. In this context, we have examined in detail the relationship of CP odd invariants for texture specific mass matrices. In particular, we have calculated the predicted ranges of Jarlskog rephasing invariant parameter and other weak basis invariants for all the seven viable cases for texture two zero mass matrices.
[ { "created": "Tue, 3 Apr 2018 09:17:06 GMT", "version": "v1" } ]
2018-04-05
[ [ "Singh", "Madan", "" ] ]
In the quark sector, Jarlskog rephasing invariant parameter $J_{CP}$ has important implications for the CP violation as well as phase structure of the quark mass matrices. In fact all CP violating effects in this sector are proportional to the magnitude of the imaginary part of $J_{CP}$ . With the observation of non-zero and large "reactor mixing angle", it is widely believed that CP might be violated in the leptonic sector. In this context, we have examined in detail the relationship of CP odd invariants for texture specific mass matrices. In particular, we have calculated the predicted ranges of Jarlskog rephasing invariant parameter and other weak basis invariants for all the seven viable cases for texture two zero mass matrices.
2309.16122
Erdenebulgan Lkhagvadorj
Ki-Young Choi, Jongkuk Kim, and Erdenebulgan Lkhagvadorj
Non-thermal WIMPy Baryogenesis with Primordial Black Hole
null
JCAP02(2024)020
10.1088/1475-7516/2024/02/020
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We consider the possibility that the weakly interacting massive particles produced from the evaporation of primordial black hole can explain both the relic density of dark matter and the baryon asymmetry of the Universe, through their annihilation which violate B and CP-symmetry. We find that the primordial black hole with mass less than $10^7 {\rm g}$ is a good candidate as an source of TeV dark matter with the total annihilation cross section $\left\langle\sigma_a \upsilon\right\rangle \lesssim 10^{-7} \ {\rm GeV}^{-2}$ and the B-violating scattering cross section $\left\langle\sigma_B \upsilon\right\rangle \lesssim 2\times 10^{-9} \ {\rm GeV^{-2}}$. This large annihilation cross section of dark matter in this model would make it available to search them in the indirect search for dark matter such as gamma-ray or neutrino observations.
[ { "created": "Thu, 28 Sep 2023 03:03:50 GMT", "version": "v1" }, { "created": "Wed, 21 Feb 2024 05:59:07 GMT", "version": "v2" } ]
2024-02-22
[ [ "Choi", "Ki-Young", "" ], [ "Kim", "Jongkuk", "" ], [ "Lkhagvadorj", "Erdenebulgan", "" ] ]
We consider the possibility that the weakly interacting massive particles produced from the evaporation of primordial black hole can explain both the relic density of dark matter and the baryon asymmetry of the Universe, through their annihilation which violate B and CP-symmetry. We find that the primordial black hole with mass less than $10^7 {\rm g}$ is a good candidate as an source of TeV dark matter with the total annihilation cross section $\left\langle\sigma_a \upsilon\right\rangle \lesssim 10^{-7} \ {\rm GeV}^{-2}$ and the B-violating scattering cross section $\left\langle\sigma_B \upsilon\right\rangle \lesssim 2\times 10^{-9} \ {\rm GeV^{-2}}$. This large annihilation cross section of dark matter in this model would make it available to search them in the indirect search for dark matter such as gamma-ray or neutrino observations.
hep-ph/0304008
K. R. S. Balaji
K.R.S. Balaji, Wilfried Horn, and E.A. Paschos
Possible test for CPT invariance with correlated neutral B decays
Revised version to be published in PRD
Phys.Rev. D68 (2003) 076004
10.1103/PhysRevD.68.076004
DO-TH 03/06
hep-ph hep-ex
null
We study breakdown of $CPT$ symmetry which can occur in the decay process $B \bar B \to l^\pm X^\mp f$ with $f$ being a CP eigenstate. In this process, the standard model expectations for time ordered semi-leptonic and hadronic events, i.e. which of the two decays takes place first, can be altered in the case that there is a violation of the $CPT$ symmetry. To illustrate this possibility, we identify and study several time integrated observables. We find that an experiment with $10^{9}$ $B\bar B$ pairs, has the capability for improving the bound on $CPT$ violating parameter or perhaps observe $CPT$ violation.
[ { "created": "Tue, 1 Apr 2003 12:07:32 GMT", "version": "v1" }, { "created": "Sat, 25 Oct 2003 21:40:44 GMT", "version": "v2" } ]
2009-11-10
[ [ "Balaji", "K. R. S.", "" ], [ "Horn", "Wilfried", "" ], [ "Paschos", "E. A.", "" ] ]
We study breakdown of $CPT$ symmetry which can occur in the decay process $B \bar B \to l^\pm X^\mp f$ with $f$ being a CP eigenstate. In this process, the standard model expectations for time ordered semi-leptonic and hadronic events, i.e. which of the two decays takes place first, can be altered in the case that there is a violation of the $CPT$ symmetry. To illustrate this possibility, we identify and study several time integrated observables. We find that an experiment with $10^{9}$ $B\bar B$ pairs, has the capability for improving the bound on $CPT$ violating parameter or perhaps observe $CPT$ violation.
hep-ph/0210015
Stefano Moretti
E. Maina (Torino), S. Moretti (CERN and IPPP), D.A. Ross (Southampton)
Weak Corrections to Three-Jet Production in Electron-Positron Annihilations: 1) The Factorisable Contributions
22 pages, latex, 7 figures (substantial revisions, version to be published in JHEP)
JHEP 0304:056,2003
10.1088/1126-6708/2003/04/056
DFTT 27/02, CERN-TH/2002-191, IPPP/02/48, DCPT/02/96, SHEP-02/24
hep-ph
null
We report on the calculation of the factorisable one-loop weak-interaction corrections to the initial and final states for three-jet observables in electron-positron annihilations. We show that such corrections are of a few percent at $\sqrt s=M_Z$. Hence, while their impact is not dramatic in the context of LEP1 and SLC, where the total error on the measured value of $\alpha_{\mathrm{S}}$ is larger, at a future Linear Collider, running at the $Z$ mass peak (e.g., GigaZ), they ought to be taken into account in the experimental fits, as here the uncertainty on the value of the strong coupling constant is expected to be at the 0.1% level or even smaller. The calculation has been performed using helicity amplitudes so that it can be applied to the case of polarised beams.
[ { "created": "Tue, 1 Oct 2002 11:53:16 GMT", "version": "v1" }, { "created": "Tue, 6 May 2003 10:38:34 GMT", "version": "v2" } ]
2011-07-19
[ [ "Maina", "E.", "", "Torino" ], [ "Moretti", "S.", "", "CERN and IPPP" ], [ "Ross", "D. A.", "", "Southampton" ] ]
We report on the calculation of the factorisable one-loop weak-interaction corrections to the initial and final states for three-jet observables in electron-positron annihilations. We show that such corrections are of a few percent at $\sqrt s=M_Z$. Hence, while their impact is not dramatic in the context of LEP1 and SLC, where the total error on the measured value of $\alpha_{\mathrm{S}}$ is larger, at a future Linear Collider, running at the $Z$ mass peak (e.g., GigaZ), they ought to be taken into account in the experimental fits, as here the uncertainty on the value of the strong coupling constant is expected to be at the 0.1% level or even smaller. The calculation has been performed using helicity amplitudes so that it can be applied to the case of polarised beams.
0705.2696
Gavin Salam
Gavin P. Salam
A Practical Seedless Infrared Safe Cone Algorithm
4 pages, 4 figures. Talk presented at the XLII Rencontres de Moriond, QCD and Hadronic Interactions, La Thuile, March 2007
null
null
null
hep-ph
null
This writeup highlights the infrared unsafety of the "midpoint" cone jet-algorithm and provides a brief overview of why this is a serious issue. It then shows how one can build a safe (seedless) cone algorithm and discusses the potential impact on measurements.
[ { "created": "Fri, 18 May 2007 13:14:44 GMT", "version": "v1" } ]
2007-05-23
[ [ "Salam", "Gavin P.", "" ] ]
This writeup highlights the infrared unsafety of the "midpoint" cone jet-algorithm and provides a brief overview of why this is a serious issue. It then shows how one can build a safe (seedless) cone algorithm and discusses the potential impact on measurements.
2312.12527
Paul Caucal
Jo\~ao Barata, Paul Caucal, Alba Soto-Ontoso, Robert Szafron
Advancing the understanding of energy-energy correlators in heavy-ion collisions
36 pages, 13 figures, fixed plotting typo in Fig. 8
null
null
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the collinear limit of the energy-energy correlator (EEC) in a heavy-ion context. First, we revisit the leading-logarithmic (LL) resummation of this observable in vacuum following a diagrammatic approach. We argue that this route allows to naturally incorporate medium-induced effects into the all-orders structure systematically. As an example, we show how the phase-space constraints imposed by the medium on vacuum-like emissions can be incorporated into the LL result by modifying the anomalous dimensions. On the fixed-order side, we calculate the $\mathcal{O}(\alpha_s)$ expansion of the in-medium EEC for a $\gamma\to q\bar q$ splitting using, for the first time, the exact matrix element. When comparing this result to previously used approximations in the literature, we find up to $\mathcal{O}(1)$ deviations in the regime of interest for jet quenching signatures. Energy loss effects are also quantified and further suppress the EEC at large angles. These semi-analytic studies are complemented with a phenomenological study using the jet quenching Monte Carlo JetMed. Finally, we argue that the imprint of medium-induced effects in energy-energy correlators can be enhanced by using an alternative definition that takes as input Lund primary declusterings instead of particles.
[ { "created": "Tue, 19 Dec 2023 19:02:10 GMT", "version": "v1" }, { "created": "Fri, 22 Dec 2023 17:15:30 GMT", "version": "v2" } ]
2023-12-25
[ [ "Barata", "João", "" ], [ "Caucal", "Paul", "" ], [ "Soto-Ontoso", "Alba", "" ], [ "Szafron", "Robert", "" ] ]
We investigate the collinear limit of the energy-energy correlator (EEC) in a heavy-ion context. First, we revisit the leading-logarithmic (LL) resummation of this observable in vacuum following a diagrammatic approach. We argue that this route allows to naturally incorporate medium-induced effects into the all-orders structure systematically. As an example, we show how the phase-space constraints imposed by the medium on vacuum-like emissions can be incorporated into the LL result by modifying the anomalous dimensions. On the fixed-order side, we calculate the $\mathcal{O}(\alpha_s)$ expansion of the in-medium EEC for a $\gamma\to q\bar q$ splitting using, for the first time, the exact matrix element. When comparing this result to previously used approximations in the literature, we find up to $\mathcal{O}(1)$ deviations in the regime of interest for jet quenching signatures. Energy loss effects are also quantified and further suppress the EEC at large angles. These semi-analytic studies are complemented with a phenomenological study using the jet quenching Monte Carlo JetMed. Finally, we argue that the imprint of medium-induced effects in energy-energy correlators can be enhanced by using an alternative definition that takes as input Lund primary declusterings instead of particles.
2109.08636
Kazuo Tsushima
G. N. Zeminiani, J. J. Cobos-Mart\'inez and K. Tsushima
[1]Title: $\Upsilon$ and $\eta_b$ mass shifts in nuclear matter and the $^{12}$C nucleus bound states, [2]Title: $\Upsilon$ and $\eta_b$ mass shifts in nuclear matter and the nucleus bound states
[1] 5 pages, 3 figures (5 eps figure files, 1 table), contribution for the PANIC 2021 proceedings (September 5 - September 10, 2021), [2] 4 pages, 3 figures (5 eps figure files, 1 table), contribution for the HADRON 2021 proceedings (July 26 - July 31, 2021)
null
null
[1] LFTC-21-5/66, [2] LFTC-21-1/62
hep-ph hep-ex nucl-ex nucl-th
http://creativecommons.org/licenses/by-nc-nd/4.0/
[1]Abstract: This is a contribution for the PANIC 2021 Proceedings based on the articles, Eur. Phys. J. A 57, 259 (2021) and the accompanied article $[$arXiv:2109.08636 $[$hep-ph$]]$ (Hadron 2021 contribution). We have estimated for the first time the mass shifts of the $\Upsilon$ and $\eta_b$ mesons in symmetric nuclear matter by an SU(5) flavor symmetric effective Lagrangian approach, as well as the in-medium mass of $B^*$ meson by the quark-meson coupling (QMC) model. The attractive potentials for the $\Upsilon$- and $\eta_b$-nuclear matter are obtained, and one can expect for these mesons to form nuclear bound states. We have indeed found such nuclear bound states with $^{12}$C nucleus, where the results for the $^{12}$C nucleus bound state energies are new, and we report here for the first time. [2]Abstract: We estimate for the first time the mass shifts (scalar potentials) in symmetric nuclear matter of the $\Upsilon$ and $\eta_b$ mesons using an effective Lagrangian approach, as well as the in-medium mass of the $B^*$ meson by the quark-meson coupling model. The attractive potentials of both $\Upsilon$ and $\eta_b$ are expected to be strong enough for these mesons to be bound to the $^4$He nucleus, and we have obtained such nuclear bound state energies.
[ { "created": "Fri, 17 Sep 2021 16:36:55 GMT", "version": "v1" }, { "created": "Fri, 12 Nov 2021 23:04:34 GMT", "version": "v2" } ]
2021-11-16
[ [ "Zeminiani", "G. N.", "" ], [ "Cobos-Martínez", "J. J.", "" ], [ "Tsushima", "K.", "" ] ]
[1]Abstract: This is a contribution for the PANIC 2021 Proceedings based on the articles, Eur. Phys. J. A 57, 259 (2021) and the accompanied article $[$arXiv:2109.08636 $[$hep-ph$]]$ (Hadron 2021 contribution). We have estimated for the first time the mass shifts of the $\Upsilon$ and $\eta_b$ mesons in symmetric nuclear matter by an SU(5) flavor symmetric effective Lagrangian approach, as well as the in-medium mass of $B^*$ meson by the quark-meson coupling (QMC) model. The attractive potentials for the $\Upsilon$- and $\eta_b$-nuclear matter are obtained, and one can expect for these mesons to form nuclear bound states. We have indeed found such nuclear bound states with $^{12}$C nucleus, where the results for the $^{12}$C nucleus bound state energies are new, and we report here for the first time. [2]Abstract: We estimate for the first time the mass shifts (scalar potentials) in symmetric nuclear matter of the $\Upsilon$ and $\eta_b$ mesons using an effective Lagrangian approach, as well as the in-medium mass of the $B^*$ meson by the quark-meson coupling model. The attractive potentials of both $\Upsilon$ and $\eta_b$ are expected to be strong enough for these mesons to be bound to the $^4$He nucleus, and we have obtained such nuclear bound state energies.
hep-ph/9909283
Armin Boehrer
Armin Boehrer
Measurement of the photon structure function at ALEPH
5 pages, 5 figures, To be published in proceedings "PHOTON99"
Nucl.Phys.Proc.Suppl. 82 (2000) 25-29
10.1016/S0920-5632(00)00127-4
SI-99-03
hep-ph
null
The photon structure function F2gamma has been measured with data taken by the ALEPH collaboration at LEP centre-of-mass energies sqrt s = 91 GeV with < Q^2 > of 9.9, 20.7 and 284 GeV^2 and sqrt s = 183 GeV with < Q^2 > of 13.7 and 56.5 GeV^2. For the data at sqrt s = 183 GeV a two-dimensional unfolding method employing the principle of maximum entropy is used, which reduces the errors compared to one-dimensional methods.
[ { "created": "Wed, 8 Sep 1999 10:02:30 GMT", "version": "v1" } ]
2009-10-31
[ [ "Boehrer", "Armin", "" ] ]
The photon structure function F2gamma has been measured with data taken by the ALEPH collaboration at LEP centre-of-mass energies sqrt s = 91 GeV with < Q^2 > of 9.9, 20.7 and 284 GeV^2 and sqrt s = 183 GeV with < Q^2 > of 13.7 and 56.5 GeV^2. For the data at sqrt s = 183 GeV a two-dimensional unfolding method employing the principle of maximum entropy is used, which reduces the errors compared to one-dimensional methods.
hep-ph/0308321
A. A. Arkhipov
A.A.Arkhipov
Mein Ruf to Search New Strange $a_2^s(1520)$-meson
2 pages, no figures
null
null
null
hep-ph hep-ex nucl-ex
null
In this note we propose to search new strange $a_2^s(1520)$-meson which is a strange partner of the $a_2(1311)$-meson observed in a three-pion system.
[ { "created": "Fri, 29 Aug 2003 18:47:38 GMT", "version": "v1" } ]
2007-05-23
[ [ "Arkhipov", "A. A.", "" ] ]
In this note we propose to search new strange $a_2^s(1520)$-meson which is a strange partner of the $a_2(1311)$-meson observed in a three-pion system.
hep-ph/0412002
Bo Feng
Xiao-Jun Bi, Bo Feng, Hong Li and Xinmin Zhang
Cosmological Evolution of Interacting Dark Energy Models with Mass Varying Neutrinos
One typographical error corrected, references updated and presentation improved
Phys.Rev. D72 (2005) 123523
10.1103/PhysRevD.72.123523
null
hep-ph astro-ph hep-ex hep-th
null
In this paper we consider the cosmological implications of dark energy models with a coupled system of a dynamical scalar field (the quintessence) and the neutrinos. By detailed numerical calculations we study the various possibilities on the evolution and the fates of the universe in this class of models. Our results show that due to the interaction with quintessence, neutrinos could be dominant over the quintessence in the future universe, however would eventually decay away.
[ { "created": "Wed, 1 Dec 2004 10:05:39 GMT", "version": "v1" }, { "created": "Wed, 2 Nov 2005 08:59:31 GMT", "version": "v2" } ]
2007-05-23
[ [ "Bi", "Xiao-Jun", "" ], [ "Feng", "Bo", "" ], [ "Li", "Hong", "" ], [ "Zhang", "Xinmin", "" ] ]
In this paper we consider the cosmological implications of dark energy models with a coupled system of a dynamical scalar field (the quintessence) and the neutrinos. By detailed numerical calculations we study the various possibilities on the evolution and the fates of the universe in this class of models. Our results show that due to the interaction with quintessence, neutrinos could be dominant over the quintessence in the future universe, however would eventually decay away.
1011.6482
Christian Fischer
Christian S. Fischer and Lorenz von Smekal
Scaling, decoupling and transversality of the gluon propagator
3 pages; Contribution to the proceedings of `Quark Confinement And The Hadron Spectrum IX', Madrid, Sept. 2010
null
10.1063/1.3574991
null
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this note we discuss a couple of technical issues relevant to solving the Dyson-Schwinger equation for the gluon propagator in Landau gauge Yang-Mills theory. In the deep infrared functional methods extract a one-parameter family of solutions generically showing a massive behavior referred to as 'decoupling' but also including the so-called 'scaling' solution with a conformal infrared behavior as a limiting case. We emphasize that the latter cannot be ruled out by technical arguments related to the removal of quadratic divergencies and transversality.
[ { "created": "Tue, 30 Nov 2010 08:43:36 GMT", "version": "v1" } ]
2015-05-20
[ [ "Fischer", "Christian S.", "" ], [ "von Smekal", "Lorenz", "" ] ]
In this note we discuss a couple of technical issues relevant to solving the Dyson-Schwinger equation for the gluon propagator in Landau gauge Yang-Mills theory. In the deep infrared functional methods extract a one-parameter family of solutions generically showing a massive behavior referred to as 'decoupling' but also including the so-called 'scaling' solution with a conformal infrared behavior as a limiting case. We emphasize that the latter cannot be ruled out by technical arguments related to the removal of quadratic divergencies and transversality.
hep-ph/0108094
Nicolas Borghini
Nicolas Borghini, Yves Gouverneur, Michel H.G. Tytgat
Anomalies and Fermion Content of Grand Unified Theories in Extra Dimensions
15 pages, revtex. v2: references added to match published version
Phys.Rev. D65 (2002) 025017
10.1103/PhysRevD.65.025017
ULB-TH-01/025
hep-ph
null
The restrictions imposed by anomaly cancellation on the chiral fermion content of nonsupersymmetric gauge theories based on various groups are studied in spacetime dimension D=6, 8, and 10. In particular, we show that the only mathematically consistent chiral SU(5) theory in D=6 contains three nonidentical generations.
[ { "created": "Fri, 10 Aug 2001 12:56:01 GMT", "version": "v1" }, { "created": "Thu, 27 Dec 2001 09:27:24 GMT", "version": "v2" } ]
2009-11-07
[ [ "Borghini", "Nicolas", "" ], [ "Gouverneur", "Yves", "" ], [ "Tytgat", "Michel H. G.", "" ] ]
The restrictions imposed by anomaly cancellation on the chiral fermion content of nonsupersymmetric gauge theories based on various groups are studied in spacetime dimension D=6, 8, and 10. In particular, we show that the only mathematically consistent chiral SU(5) theory in D=6 contains three nonidentical generations.
hep-ph/0607214
Kim Maltman
K. Maltman and C.E. Wolfe
V_us From Hadronic Tau Decays
4 pages, prepared for the proceedings of the 9th Conference on the Intersections of Particle and Nuclear Physics (CIPANP06), Westin Rio Mar Resort, Puerto Rico, May 30-June 3, 2006
Phys.Lett. B639 (2006) 283-289
10.1063/1.2402645
null
hep-ph
null
We study extractions of |V_us| based on finite energy sum rule (FESR) analyses of hadronic tau decay data. We show (i) that the ``(0,0) spectral weight'' implementation (proposed previously in the literature as a favorable version of this analysis) suffers from significant convergence problems, but (ii) that alternate implementations exist which bring these problems under control. Results based on present spectral data are shown to be in agreement with those of other approaches, though with, at present, somewhat larger experimental errors. Sub-1% determinations of |V_us| are also shown to be expected from these alternate analyses once tau data from the B factories becomes available.
[ { "created": "Wed, 19 Jul 2006 16:35:38 GMT", "version": "v1" } ]
2009-11-11
[ [ "Maltman", "K.", "" ], [ "Wolfe", "C. E.", "" ] ]
We study extractions of |V_us| based on finite energy sum rule (FESR) analyses of hadronic tau decay data. We show (i) that the ``(0,0) spectral weight'' implementation (proposed previously in the literature as a favorable version of this analysis) suffers from significant convergence problems, but (ii) that alternate implementations exist which bring these problems under control. Results based on present spectral data are shown to be in agreement with those of other approaches, though with, at present, somewhat larger experimental errors. Sub-1% determinations of |V_us| are also shown to be expected from these alternate analyses once tau data from the B factories becomes available.
0707.3859
Guy F. de T\'eramond
Stanley J. Brodsky and Guy F. de Teramond
Light-Front Dynamics and AdS/QCD Correspondence: The Pion Form Factor in the Space- and Time-Like Regions
21 pages, 7 figures. Title adjusted to PRD title. Typo corrected in Eq (B3)
Phys.Rev.D77:056007,2008
10.1103/PhysRevD.77.056007
SLAC-PUB 12544
hep-ph hep-th
null
The AdS/CFT correspondence between string theory in AdS space and conformal field theories in physical space-time leads to an analytic, semi-classical model for strongly-coupled QCD which has scale invariance and dimensional counting at short distances and color confinement at large distances. The AdS/CFT correspondence also provides insights into the inherently non-perturbative aspects of QCD such as the orbital and radial spectra of hadrons and the form of hadronic wavefunctions. In particular, we show that there is an exact correspondence between the fifth-dimensional coordinate of anti-de Sitter (AdS) space $z$ and a specific light-front impact variable $\zeta$ which measures the separation of the quark and gluonic constituents within the hadron in ordinary space-time. This connection allows one to compute the analytic form of the frame-independent light-front wavefunctions of mesons and baryons, the fundamental entities which encode hadron properties and which allow the computation of decay constants, form factors and other exclusive scattering amplitudes. Relativistic light-front equations in ordinary space-time are found which reproduce the results obtained using the fifth-dimensional theory. As specific examples we compute the pion coupling constant $f_\pi$, the pion charge radius $< r_\pi^2 >$ and examine the propagation of the electromagnetic current in AdS space, which determines the space and time-like behavior of the pion form factor and the pole of the $\rho$ meson.
[ { "created": "Thu, 26 Jul 2007 06:51:40 GMT", "version": "v1" }, { "created": "Sat, 13 Oct 2007 08:43:54 GMT", "version": "v2" }, { "created": "Tue, 11 Mar 2008 02:47:33 GMT", "version": "v3" }, { "created": "Mon, 31 Mar 2008 16:32:40 GMT", "version": "v4" } ]
2008-11-26
[ [ "Brodsky", "Stanley J.", "" ], [ "de Teramond", "Guy F.", "" ] ]
The AdS/CFT correspondence between string theory in AdS space and conformal field theories in physical space-time leads to an analytic, semi-classical model for strongly-coupled QCD which has scale invariance and dimensional counting at short distances and color confinement at large distances. The AdS/CFT correspondence also provides insights into the inherently non-perturbative aspects of QCD such as the orbital and radial spectra of hadrons and the form of hadronic wavefunctions. In particular, we show that there is an exact correspondence between the fifth-dimensional coordinate of anti-de Sitter (AdS) space $z$ and a specific light-front impact variable $\zeta$ which measures the separation of the quark and gluonic constituents within the hadron in ordinary space-time. This connection allows one to compute the analytic form of the frame-independent light-front wavefunctions of mesons and baryons, the fundamental entities which encode hadron properties and which allow the computation of decay constants, form factors and other exclusive scattering amplitudes. Relativistic light-front equations in ordinary space-time are found which reproduce the results obtained using the fifth-dimensional theory. As specific examples we compute the pion coupling constant $f_\pi$, the pion charge radius $< r_\pi^2 >$ and examine the propagation of the electromagnetic current in AdS space, which determines the space and time-like behavior of the pion form factor and the pole of the $\rho$ meson.
1706.00792
Alberto Salvio
Aris Joti, Aris Katsis, Dimitris Loupas, Alberto Salvio, Alessandro Strumia, Nikolaos Tetradis, Alfredo Urbano
(Higgs) vacuum decay during inflation
23 pages, 5 figures; references added, matches version published in JHEP
JHEP 1707 (2017) 058
10.1007/JHEP07(2017)058
CERN-TH-2017-121, IFUP-TH/2017
hep-ph gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We develop the formalism for computing gravitational corrections to vacuum decay from de Sitter space as a sub-Planckian perturbative expansion. Non-minimal coupling to gravity can be encoded in an effective potential. The Coleman bounce continuously deforms into the Hawking-Moss bounce, until they coincide for a critical value of the Hubble constant. As an application, we reconsider the decay of the electroweak Higgs vacuum during inflation. Our vacuum decay computation reproduces and improves bounds on the maximal inflationary Hubble scale previously computed through statistical techniques.
[ { "created": "Fri, 2 Jun 2017 18:00:07 GMT", "version": "v1" }, { "created": "Fri, 14 Jul 2017 06:38:11 GMT", "version": "v2" } ]
2017-07-17
[ [ "Joti", "Aris", "" ], [ "Katsis", "Aris", "" ], [ "Loupas", "Dimitris", "" ], [ "Salvio", "Alberto", "" ], [ "Strumia", "Alessandro", "" ], [ "Tetradis", "Nikolaos", "" ], [ "Urbano", "Alfredo", "" ] ]
We develop the formalism for computing gravitational corrections to vacuum decay from de Sitter space as a sub-Planckian perturbative expansion. Non-minimal coupling to gravity can be encoded in an effective potential. The Coleman bounce continuously deforms into the Hawking-Moss bounce, until they coincide for a critical value of the Hubble constant. As an application, we reconsider the decay of the electroweak Higgs vacuum during inflation. Our vacuum decay computation reproduces and improves bounds on the maximal inflationary Hubble scale previously computed through statistical techniques.
1006.3322
Yanou Cui
Yanou Cui, Tony Gherghetta, James Stokes
Fermion Masses in Emergent Electroweak Symmetry Breaking
modified discussion in Sec 3.1, version published in JHEP
JHEP 1012:075,2010
10.1007/JHEP12(2010)075
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the generation of fermion masses in an emergent model of electroweak symmetry breaking with composite $W,Z$ gauge bosons. A universal bulk fermion profile in a warped extra dimension is used for all fermion flavors. Electroweak symmetry is broken at the UV (or Planck) scale where boundary mass terms are added to generate the fermion flavor structure. This leads to flavor-dependent nonuniversality in the gauge couplings. The effects are suppressed for the light fermion generations but are enhanced for the top quark where the $Zt{\bar t}$ and $Wt{\bar b}$ couplings can deviate at the $10-20%$ level in the minimal setup. By the AdS/CFT correspondence our model implies that electroweak symmetry is not a fundamental gauge symmetry. Instead the Standard Model with massive fermions and $W,Z$ gauge bosons is an effective chiral Lagrangian for some underlying confining strong dynamics at the TeV scale, where mass is generated without a Higgs mechanism.
[ { "created": "Wed, 16 Jun 2010 20:42:58 GMT", "version": "v1" }, { "created": "Mon, 20 Dec 2010 21:37:12 GMT", "version": "v2" } ]
2011-01-04
[ [ "Cui", "Yanou", "" ], [ "Gherghetta", "Tony", "" ], [ "Stokes", "James", "" ] ]
We consider the generation of fermion masses in an emergent model of electroweak symmetry breaking with composite $W,Z$ gauge bosons. A universal bulk fermion profile in a warped extra dimension is used for all fermion flavors. Electroweak symmetry is broken at the UV (or Planck) scale where boundary mass terms are added to generate the fermion flavor structure. This leads to flavor-dependent nonuniversality in the gauge couplings. The effects are suppressed for the light fermion generations but are enhanced for the top quark where the $Zt{\bar t}$ and $Wt{\bar b}$ couplings can deviate at the $10-20%$ level in the minimal setup. By the AdS/CFT correspondence our model implies that electroweak symmetry is not a fundamental gauge symmetry. Instead the Standard Model with massive fermions and $W,Z$ gauge bosons is an effective chiral Lagrangian for some underlying confining strong dynamics at the TeV scale, where mass is generated without a Higgs mechanism.
0810.5208
Makiko Nio
T. Aoyama, M. Hayakawa, T. Kinoshita, and M. Nio
Tenth-Order Lepton Anomalous Magnetic Moment -- Second-Order Vertex Containing Two Vacuum Polarization Subdiagrams, One Within the Other
15 pages, 2 figures. References are added
Phys.Rev.D78:113006,2008
10.1103/PhysRevD.78.113006
NTLP 2008-02
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper reports the tenth-order QED contribution to the g-2 of electron and muon from two gauge-invariant sets, Set I(g) and Set I(h). In the case of electron g-2 Set I(g) consists of 9 Feynman diagrams which have a 4th-order vacuum-polarization loop containing another 4th-order vacuum-polarization loop. Set I(h) consists of 30 Feynman diagrams which have a proper 6th-order vacuum-polarization loop containing a second-order vacuum-polarization loop. The results of numerical integration, including mass-dependent terms containing one closed loop of muon, are 0.028 597 (4) (alpha/pi)^5 for Set I(g) and 0.001 685 (13) (alpha/pi)^5 for Set I(h), respectively. We also report the contributions of Set I(g) and Set I(h) to the muon anomaly. Diagrams included are those containing electron, muon, and tau-lepton loops. Their sums are 2.640 9 (4) (alpha/pi)^5 and -0.564 8 (11) (alpha/pi)^5, respectively. The sum of contributions of Sets I(g) and I(h) containing only electron loops are in fair agreement with the recently obtained asymptotic analytic results.
[ { "created": "Wed, 29 Oct 2008 07:36:16 GMT", "version": "v1" }, { "created": "Thu, 6 Nov 2008 01:39:40 GMT", "version": "v2" }, { "created": "Wed, 17 Dec 2008 06:00:36 GMT", "version": "v3" } ]
2009-01-08
[ [ "Aoyama", "T.", "" ], [ "Hayakawa", "M.", "" ], [ "Kinoshita", "T.", "" ], [ "Nio", "M.", "" ] ]
This paper reports the tenth-order QED contribution to the g-2 of electron and muon from two gauge-invariant sets, Set I(g) and Set I(h). In the case of electron g-2 Set I(g) consists of 9 Feynman diagrams which have a 4th-order vacuum-polarization loop containing another 4th-order vacuum-polarization loop. Set I(h) consists of 30 Feynman diagrams which have a proper 6th-order vacuum-polarization loop containing a second-order vacuum-polarization loop. The results of numerical integration, including mass-dependent terms containing one closed loop of muon, are 0.028 597 (4) (alpha/pi)^5 for Set I(g) and 0.001 685 (13) (alpha/pi)^5 for Set I(h), respectively. We also report the contributions of Set I(g) and Set I(h) to the muon anomaly. Diagrams included are those containing electron, muon, and tau-lepton loops. Their sums are 2.640 9 (4) (alpha/pi)^5 and -0.564 8 (11) (alpha/pi)^5, respectively. The sum of contributions of Sets I(g) and I(h) containing only electron loops are in fair agreement with the recently obtained asymptotic analytic results.
1409.0611
Abhishek Dey
Utpal Chattopadhyay, Abhishek Dey (IACS, Kolkata)
Exploring MSSM for Charge and Color Breaking and Other Constraints in the Context of Higgs@125 GeV
29 pages, pdfLaTex. Rechecked the long-lived states for accuracy with no essential change in results. Conclusion unchanged
null
10.1007/JHEP11(2014)161
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Exploring MSSM parameter space after the discovery of Higgs Boson with mass 125 GeV naturally demands large top-squark mixing or large trilinear coupling parameter $A_t$ in particular, so as to avoid excessively heavy squark, specially for the universal models like CMSSM. We study stability of electroweak symmetry breaking vacua in possible presence of deeper charge-color symmetry breaking minima within MSSM. Besides stable vacua, we consider scenarios characterized by the presence of global CCB minima, with SM like charge and color conserving vacuum, having stability over cosmologically large lifetime {(\it long-lived states)}. We allow vacuum expectation values for both stop as well as sbottom fields, since these belong to the third generation of sfermions with larger Yukawa couplings that have immediate effect on the tunneling time. Moreover, for large $\mu$ regions, radiative corrections to Higgs boson mass from bottom-squark loop is quite significant. Regions of MSSM parameters space become viable for large $A_t$ and large $\mu$ zones which are generically excluded via the traditional analytical CCB constraints. For a large value of $\tan\beta$, safe vacua associated with large values of $|\mu|$ and $|A_t|$ are predominantly long-lived and may be associated with relatively light stop masses. We also identify low $\mu$ regions associated with long-lived states. Both the above zones can be friendly to muon $g-2$ constraint. We also impose constraints from ${\rm Br}(B \rightarrow X_s \gamma)$ and ${\rm Br}(B_s \rightarrow \mu^+ \mu^-)$. We do the analysis for a moderate and a large $\tan\beta$. Results are compatible with dark matter related constraints, as expected.
[ { "created": "Tue, 2 Sep 2014 06:20:42 GMT", "version": "v1" }, { "created": "Fri, 26 Sep 2014 13:59:36 GMT", "version": "v2" } ]
2015-06-22
[ [ "Chattopadhyay", "Utpal", "", "IACS, Kolkata" ], [ "Dey", "Abhishek", "", "IACS, Kolkata" ] ]
Exploring MSSM parameter space after the discovery of Higgs Boson with mass 125 GeV naturally demands large top-squark mixing or large trilinear coupling parameter $A_t$ in particular, so as to avoid excessively heavy squark, specially for the universal models like CMSSM. We study stability of electroweak symmetry breaking vacua in possible presence of deeper charge-color symmetry breaking minima within MSSM. Besides stable vacua, we consider scenarios characterized by the presence of global CCB minima, with SM like charge and color conserving vacuum, having stability over cosmologically large lifetime {(\it long-lived states)}. We allow vacuum expectation values for both stop as well as sbottom fields, since these belong to the third generation of sfermions with larger Yukawa couplings that have immediate effect on the tunneling time. Moreover, for large $\mu$ regions, radiative corrections to Higgs boson mass from bottom-squark loop is quite significant. Regions of MSSM parameters space become viable for large $A_t$ and large $\mu$ zones which are generically excluded via the traditional analytical CCB constraints. For a large value of $\tan\beta$, safe vacua associated with large values of $|\mu|$ and $|A_t|$ are predominantly long-lived and may be associated with relatively light stop masses. We also identify low $\mu$ regions associated with long-lived states. Both the above zones can be friendly to muon $g-2$ constraint. We also impose constraints from ${\rm Br}(B \rightarrow X_s \gamma)$ and ${\rm Br}(B_s \rightarrow \mu^+ \mu^-)$. We do the analysis for a moderate and a large $\tan\beta$. Results are compatible with dark matter related constraints, as expected.
hep-ph/0207369
Tom Steele
Ailin Zhang and T.G. Steele
Can the Mechanism for $\pi_1\to \eta\pi,\eta'\pi$ Hybrid Decays be Detected?
5 pages, revtex, 1 eps figure embedded in manuscript. Analysis and references extended in v2
Phys.Rev.D67:074020,2003
10.1103/PhysRevD.67.074020
null
hep-ph
null
Two mechanisms for the $\pi_1$ ($J^{PC}=1^{-+}$) hybrid meson decay processes $\pi_1\to\eta\pi,\eta'\pi$ are investigated. These mechanisms are applied to $\phi\to\eta\gamma,\eta'\gamma$ and $J/\psi\to\eta\gamma,\eta'\gamma$ decays to illustrate the validity of the decay mechanisms and to obtain independent information on the coupling of $\eta,\eta'$ to quark and gluonic operators. From this information, we find that $\Gamma(\pi_1\to\eta\pi)/\Gamma(\pi_1\to\eta'\pi)$ is substantially different in the two decay mechanisms, and hence future experimental measurements of this ratio will provide valuable information for substantiating the hybrid nature of these states and for determining the mechanism for these hybrid decays.
[ { "created": "Wed, 31 Jul 2002 17:28:26 GMT", "version": "v1" }, { "created": "Tue, 18 Feb 2003 15:01:15 GMT", "version": "v2" } ]
2008-11-26
[ [ "Zhang", "Ailin", "" ], [ "Steele", "T. G.", "" ] ]
Two mechanisms for the $\pi_1$ ($J^{PC}=1^{-+}$) hybrid meson decay processes $\pi_1\to\eta\pi,\eta'\pi$ are investigated. These mechanisms are applied to $\phi\to\eta\gamma,\eta'\gamma$ and $J/\psi\to\eta\gamma,\eta'\gamma$ decays to illustrate the validity of the decay mechanisms and to obtain independent information on the coupling of $\eta,\eta'$ to quark and gluonic operators. From this information, we find that $\Gamma(\pi_1\to\eta\pi)/\Gamma(\pi_1\to\eta'\pi)$ is substantially different in the two decay mechanisms, and hence future experimental measurements of this ratio will provide valuable information for substantiating the hybrid nature of these states and for determining the mechanism for these hybrid decays.
hep-ph/0107152
Stefan Gieseke
J. Bartels, S. Gieseke, A. Kyrieleis
The Process \gamma^{*}_L+ q \to q\bar{q}g + q: Real Corrections to the Virtual Photon Impact Factor
17 pages, 4 figures, revtex
Phys.Rev.D65:014006,2002
10.1103/PhysRevD.65.014006
null
hep-ph
null
We calculate, for the longitudinally polarized virtual photon, the cross section of the process \gamma^{*}+q\to (q\bar{q}g)+q at high energies with a large rapidity gap between the fragmentation system q\bar{q}g and the other quark. This process provides the real corrections of the virtual photon impact factor in the next-to leading order. Evidence is given for the appearance of a new q\bar{q}g Fock-component of the photon state.
[ { "created": "Fri, 13 Jul 2001 16:36:04 GMT", "version": "v1" } ]
2014-11-17
[ [ "Bartels", "J.", "" ], [ "Gieseke", "S.", "" ], [ "Kyrieleis", "A.", "" ] ]
We calculate, for the longitudinally polarized virtual photon, the cross section of the process \gamma^{*}+q\to (q\bar{q}g)+q at high energies with a large rapidity gap between the fragmentation system q\bar{q}g and the other quark. This process provides the real corrections of the virtual photon impact factor in the next-to leading order. Evidence is given for the appearance of a new q\bar{q}g Fock-component of the photon state.
0911.5059
Jean-Paul Blaizot
Jean-Paul Blaizot
Phases of hot and dense QCD matter
6 pages, 1 figure, invited talk at the 10th International Conference on Nucleus-Nucleus Collisions, Aug 16-21, 2009, Beijing, China
Nucl.Phys.A834:515c-520c,2010
10.1016/j.nuclphysa.2010.01.080
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This talk summarizes some of the theoretical issues currently most debated in the field of hot and dense QCD matter and ultra-relativistic heavy ion collisions.
[ { "created": "Thu, 26 Nov 2009 11:02:54 GMT", "version": "v1" } ]
2014-11-20
[ [ "Blaizot", "Jean-Paul", "" ] ]
This talk summarizes some of the theoretical issues currently most debated in the field of hot and dense QCD matter and ultra-relativistic heavy ion collisions.
1207.6689
Sara Khatibi
Sara Khatibi and Mojtaba Mohammadi Najafabadi
Top Quark Asymmetries and Unparticle Physics
12 pages,5 figures
Phys. Rev. D 87, 037701 (2013)
10.1103/PhysRevD.87.037701
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Among different measured observables of top-antitop quark pairs at hadron colliders, the forward-backward asymmetry ($A_{\text{FB}}$) measured by the CDF and D0 collaborations has inconsistency with the Standard Model prediction. The measured forward-backward asymmetry grows with $t\bar{t}$ invariant mass. Several new physics models have been proposed to explain this deviation. We consider the consistency of the parameter space of vector unparticle (in Flavor-Conserving scenario) with the existing $t\bar{t}$ production measurements. In particular, we look at the total cross sections at the LHC and Tevatron, differential cross section with $t\bar{t}$ invariant mass, and the LHC charge asymmetry to identify the regions in parameter space that can give the desired top $A_{\text{FB}}$ observed by the Tevatron. We show that in spite of the intrinsic tension between the LHC charge asymmetry and $A_{\text{FB}}$, there exists a region in the unparticle parameters space where the top $A_{\text{FB}}$ and the LHC charge asymmetry are satisfied simultaneously. Finally, we show that the consistent region with $t\bar{t}$ observables is consistent with the constraints coming from the dijet resonance searches.
[ { "created": "Sat, 28 Jul 2012 07:45:50 GMT", "version": "v1" }, { "created": "Wed, 20 Feb 2013 15:50:38 GMT", "version": "v2" } ]
2013-02-21
[ [ "Khatibi", "Sara", "" ], [ "Najafabadi", "Mojtaba Mohammadi", "" ] ]
Among different measured observables of top-antitop quark pairs at hadron colliders, the forward-backward asymmetry ($A_{\text{FB}}$) measured by the CDF and D0 collaborations has inconsistency with the Standard Model prediction. The measured forward-backward asymmetry grows with $t\bar{t}$ invariant mass. Several new physics models have been proposed to explain this deviation. We consider the consistency of the parameter space of vector unparticle (in Flavor-Conserving scenario) with the existing $t\bar{t}$ production measurements. In particular, we look at the total cross sections at the LHC and Tevatron, differential cross section with $t\bar{t}$ invariant mass, and the LHC charge asymmetry to identify the regions in parameter space that can give the desired top $A_{\text{FB}}$ observed by the Tevatron. We show that in spite of the intrinsic tension between the LHC charge asymmetry and $A_{\text{FB}}$, there exists a region in the unparticle parameters space where the top $A_{\text{FB}}$ and the LHC charge asymmetry are satisfied simultaneously. Finally, we show that the consistent region with $t\bar{t}$ observables is consistent with the constraints coming from the dijet resonance searches.
hep-ph/0210425
Rohini M. Godbole
R.M. Godbole
Three-body decays of $\tilde \chi_1^0$ in $\rp$ models with dominant $\lambda$ and $\lambda'$ couplings
8 pages, five figures, Talk presented at the 10th international conference on supersymmetry and unification of fundamental interactions, SUSY02, June 17-23, 2002, Hamburg (Germany)
null
null
CERN-TH/2002-305
hep-ph
null
Decays of the lightest neutralino are studied in $R_p$-violating models, with operators $\lambda^\prime L Q D^c$ and $\lambda L L E^c$ involving third-generation matter fields and with dominant $\lambda^\prime$ and $\lambda$ couplings. Decays with the top-quark among the particles produced are considered, in addition to those with an almost massless final state. Phenomenological analyses for examples of both classes of decays are presented. No specific assumption on the composition of the lightest neutralino is made. Our formulae can easily be generalized to study decays of heavier neutralinos. We also discuss effects of the $\rp$ decays of the $\tilde \chi_1^0$ on the possible faking of the $H^\pm$ signal at the LHC by the recently pointed out $\tilde \tau \bar b t$ production through $\lambda'_{333}$ coupling.
[ { "created": "Wed, 30 Oct 2002 14:06:38 GMT", "version": "v1" } ]
2007-05-23
[ [ "Godbole", "R. M.", "" ] ]
Decays of the lightest neutralino are studied in $R_p$-violating models, with operators $\lambda^\prime L Q D^c$ and $\lambda L L E^c$ involving third-generation matter fields and with dominant $\lambda^\prime$ and $\lambda$ couplings. Decays with the top-quark among the particles produced are considered, in addition to those with an almost massless final state. Phenomenological analyses for examples of both classes of decays are presented. No specific assumption on the composition of the lightest neutralino is made. Our formulae can easily be generalized to study decays of heavier neutralinos. We also discuss effects of the $\rp$ decays of the $\tilde \chi_1^0$ on the possible faking of the $H^\pm$ signal at the LHC by the recently pointed out $\tilde \tau \bar b t$ production through $\lambda'_{333}$ coupling.
hep-ph/9802348
null
Jian-Jun Yang, Bo-Qiang Ma, Guang-Lie Li
The Non-perturbative Effect on $R=\sigma_L /\sigma_T$ from QCD Vacuum
13 pages, LaTeX, 2 eps figures, To appear in Phys. Lett. B
Phys.Lett. B423 (1998) 162-168
10.1016/S0370-2693(98)00094-X
null
hep-ph
null
We investigate the non-perturbative effects on the ratio $R=\sigma_L /\sigma_T$ in lepton-nucleon deep inelastic scattering by taking into account the lowest dimensional condensate contributions from the QCD vacuum. By combining conventional perturbative QCD corrections and the Georgi- Politzer target-mass effects with the non-perturbative effects from the QCD vacuum, we give a good description of the $Q^2$ and $x$ dependences of $R$ in comparison with the recent experimental data.
[ { "created": "Wed, 18 Feb 1998 14:11:40 GMT", "version": "v1" } ]
2009-10-31
[ [ "Yang", "Jian-Jun", "" ], [ "Ma", "Bo-Qiang", "" ], [ "Li", "Guang-Lie", "" ] ]
We investigate the non-perturbative effects on the ratio $R=\sigma_L /\sigma_T$ in lepton-nucleon deep inelastic scattering by taking into account the lowest dimensional condensate contributions from the QCD vacuum. By combining conventional perturbative QCD corrections and the Georgi- Politzer target-mass effects with the non-perturbative effects from the QCD vacuum, we give a good description of the $Q^2$ and $x$ dependences of $R$ in comparison with the recent experimental data.
1401.5989
Khamidbi Mukhamedovich Beshtoev
Kh. M. Beshtoev
Problem of oscillations presence at $CP$ violation in the system of $K^o$ mesons
12 pages, 5 figuries
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work there are considered two approaches to the description of $K^o, \bar K^o$ meson transitions into $K_S (K^o_1)$ mesons at $CP$ violation in weak interactions. The first approach uses the standard theory of oscillations and the second approach supposes that ($K_S, K_L$) states which arise at $CP$ violation are normalized but not orthogonal state functions then there arise interferences between these states but not oscillations. It is necessary to remark that the available experimental data are in good agreement with the second approach. So we came to the conclusion that oscillations do not arise at $CP$ violation in weak interactions in the system of $K^o$ mesons. Only interference between two - $K_S, K_L$ states takes place there.
[ { "created": "Wed, 22 Jan 2014 08:17:24 GMT", "version": "v1" }, { "created": "Mon, 24 Feb 2014 08:40:08 GMT", "version": "v2" } ]
2014-02-25
[ [ "Beshtoev", "Kh. M.", "" ] ]
In this work there are considered two approaches to the description of $K^o, \bar K^o$ meson transitions into $K_S (K^o_1)$ mesons at $CP$ violation in weak interactions. The first approach uses the standard theory of oscillations and the second approach supposes that ($K_S, K_L$) states which arise at $CP$ violation are normalized but not orthogonal state functions then there arise interferences between these states but not oscillations. It is necessary to remark that the available experimental data are in good agreement with the second approach. So we came to the conclusion that oscillations do not arise at $CP$ violation in weak interactions in the system of $K^o$ mesons. Only interference between two - $K_S, K_L$ states takes place there.
1704.00464
Ahmad Jafar Arifi
A. J. Arifi, H. Nagahiro, A. Hosaka
Three-Body Decay of $\Lambda_c^{*} (2595)$ and $\Lambda_c^{*} (2625)$ with Consideration of $\Sigma_c(2455)\pi$ and $\Sigma_c^*(2520)\pi$ in Intermediate States
9 pages, 9 figures
Phys. Rev. D 95, 114018 (2017)
10.1103/PhysRevD.95.114018
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Three-body decay of charmed baryons $\Lambda^*_c(2595)$ and $\Lambda^*_c(2625)$ into $\Lambda_c \pi \pi$ are studied with effective Lagrangians in which the coupling constants are extracted from the non-relativistic quark model. We take into account sequential processes going through $\Sigma_c (2455)$ and $\Sigma^*_c (2520)$ in intermediate states. The total decay widths are sensitive to the coupling of $\Lambda^*_c$ with $\Sigma_c \pi$ open channel and to $\Sigma^*_c \pi$ closed channel. We find that $\Lambda_c^*(2595)$ and $\Lambda_c^*(2625)$ with $\lambda$ mode assignment can explain nicely the experimental data. We also show invariant mass distributions of $\Lambda_c^*(2595)$ and $\Lambda_c^*(2625)$ decays which are significantly different for various quark configurations.
[ { "created": "Mon, 3 Apr 2017 08:10:41 GMT", "version": "v1" } ]
2017-06-27
[ [ "Arifi", "A. J.", "" ], [ "Nagahiro", "H.", "" ], [ "Hosaka", "A.", "" ] ]
Three-body decay of charmed baryons $\Lambda^*_c(2595)$ and $\Lambda^*_c(2625)$ into $\Lambda_c \pi \pi$ are studied with effective Lagrangians in which the coupling constants are extracted from the non-relativistic quark model. We take into account sequential processes going through $\Sigma_c (2455)$ and $\Sigma^*_c (2520)$ in intermediate states. The total decay widths are sensitive to the coupling of $\Lambda^*_c$ with $\Sigma_c \pi$ open channel and to $\Sigma^*_c \pi$ closed channel. We find that $\Lambda_c^*(2595)$ and $\Lambda_c^*(2625)$ with $\lambda$ mode assignment can explain nicely the experimental data. We also show invariant mass distributions of $\Lambda_c^*(2595)$ and $\Lambda_c^*(2625)$ decays which are significantly different for various quark configurations.
hep-ph/0102179
Serguei Bitioukov
S.I. Bityukov (IHEP, Protvino), N.V. Krasnikov (INR, Moscow)
The LHC (CMS) Discovery Potential for Models with Effective Supersymmetry and Nonuniversal Gaugino Masses
1 latex (35 pages), 4 eps (figures) files
Phys.Atom.Nucl. 65 (2002) 1341-1351; Yad.Fiz. 65 (2002) 1374-1384
10.1134/1.1495646
null
hep-ph
null
We investigate squark and gluino pair production at LHC (CMS) with subsequent decays into quarks, leptons and LSP in models with effective supersymmetry where third generation of squarks is relatively light while the first two generations of squarks are heavy. We consider the general case of nonuniversal gaugino masses. Visibility of signal by an excess over SM background in (n \geq 2)jets + (m \geq 0)leptons + E^{miss}_T events depends rather strongly on the relation between LSP, second neutralino, gluino and squark masses and it decreases with the increase of LSP mass. We find that for relatively heavy gluino it is very difficult to detect SUSY signal even for light 3^{rd} generation squarks (m_{\tilde q_3}\le 1 TeV) if the LSP mass is closed to the 3^{rd} generation squark mass.
[ { "created": "Wed, 14 Feb 2001 20:35:26 GMT", "version": "v1" } ]
2009-11-07
[ [ "Bityukov", "S. I.", "", "IHEP, Protvino" ], [ "Krasnikov", "N. V.", "", "INR, Moscow" ] ]
We investigate squark and gluino pair production at LHC (CMS) with subsequent decays into quarks, leptons and LSP in models with effective supersymmetry where third generation of squarks is relatively light while the first two generations of squarks are heavy. We consider the general case of nonuniversal gaugino masses. Visibility of signal by an excess over SM background in (n \geq 2)jets + (m \geq 0)leptons + E^{miss}_T events depends rather strongly on the relation between LSP, second neutralino, gluino and squark masses and it decreases with the increase of LSP mass. We find that for relatively heavy gluino it is very difficult to detect SUSY signal even for light 3^{rd} generation squarks (m_{\tilde q_3}\le 1 TeV) if the LSP mass is closed to the 3^{rd} generation squark mass.
0810.3052
Ivan Vitev
Ivan Vitev, Ben-Wei Zhang, Simon Wicks
The theory and phenomenology of jets in nuclear collisions
Proceedings of Hot Quarks 2008. 6 pages, 6 ps and eps figures
Eur.Phys.J.C62:139-144,2009
10.1140/epjc/s10052-009-1025-z
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review selected results from a recent in-depth study of jet shapes and jet cross sections in ultra-relativistic reactions with heavy nuclei at the LHC arXiv:0810.2807 [hep-ph]. We demonstrate that at the highest collider energies these observables become feasible as a new, differential and accurate test of the underlying QCD theory. Our approach allows for detailed simulations of the experimental acceptance/cuts that help isolate jets emerging from a dense QGP. We show for the first time that the pattern of stimulated gluon emission can be correlated with a variable quenching of the jet rates and provide an approximately model-independent approach to determining the characteristics of the medium-induced bremsstrahlung spectrum. The connection between such cross section attenuation and the in-medium jet shapes is elucidated.
[ { "created": "Fri, 17 Oct 2008 03:18:13 GMT", "version": "v1" } ]
2009-07-22
[ [ "Vitev", "Ivan", "" ], [ "Zhang", "Ben-Wei", "" ], [ "Wicks", "Simon", "" ] ]
We review selected results from a recent in-depth study of jet shapes and jet cross sections in ultra-relativistic reactions with heavy nuclei at the LHC arXiv:0810.2807 [hep-ph]. We demonstrate that at the highest collider energies these observables become feasible as a new, differential and accurate test of the underlying QCD theory. Our approach allows for detailed simulations of the experimental acceptance/cuts that help isolate jets emerging from a dense QGP. We show for the first time that the pattern of stimulated gluon emission can be correlated with a variable quenching of the jet rates and provide an approximately model-independent approach to determining the characteristics of the medium-induced bremsstrahlung spectrum. The connection between such cross section attenuation and the in-medium jet shapes is elucidated.
1209.6030
Zhong-Bo Kang
Zhong-Bo Kang, Ivan Vitev, Hongxi Xing
Nuclear modification of high transverse momentum particle production in p+A collisions at RHIC and LHC
8 pages, 4 figures
Phys.Lett. B718 (2012) 482-487
10.1016/j.physletb.2012.10.046
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present results and predictions for the nuclear modification of the differential cross sections for inclusive light hadron and prompt photon production in minimum bias d+Au collisions at $\sqrt{s} = 200$ GeV and minimum bias p+Pb collisions at $\sqrt{s} = 5$ TeV at RHIC and LHC, respectively. Our calculations combine the leading order perturbative QCD formalism with cold nuclear matter effects that arise from the elastic, inelastic and coherent multiple scattering of partons in large nuclei. We find that a theoretical approach that includes the isospin effect, Cronin effect, cold nuclear matter energy loss and dynamical shadowing can describe the RHIC d+Au data rather well. The LHC p+Pb predictions will soon be confronted by new experimental results to help clarify the magnitude and origin of cold nuclear matter effects and facilitate precision dense QCD matter tomography.
[ { "created": "Wed, 26 Sep 2012 18:51:54 GMT", "version": "v1" } ]
2012-11-27
[ [ "Kang", "Zhong-Bo", "" ], [ "Vitev", "Ivan", "" ], [ "Xing", "Hongxi", "" ] ]
We present results and predictions for the nuclear modification of the differential cross sections for inclusive light hadron and prompt photon production in minimum bias d+Au collisions at $\sqrt{s} = 200$ GeV and minimum bias p+Pb collisions at $\sqrt{s} = 5$ TeV at RHIC and LHC, respectively. Our calculations combine the leading order perturbative QCD formalism with cold nuclear matter effects that arise from the elastic, inelastic and coherent multiple scattering of partons in large nuclei. We find that a theoretical approach that includes the isospin effect, Cronin effect, cold nuclear matter energy loss and dynamical shadowing can describe the RHIC d+Au data rather well. The LHC p+Pb predictions will soon be confronted by new experimental results to help clarify the magnitude and origin of cold nuclear matter effects and facilitate precision dense QCD matter tomography.
1710.03724
Andreas Maier
Andreas Maier, Peter Marquard
Life of \Pi
21 pages, 2 figures. Equivalent to journal version
Phys. Rev. D 97, 056016 (2018)
10.1103/PhysRevD.97.056016
DESY 17-154, IPPP/17/71
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The heavy-quark contribution to the polarisation function $\Pi$ at higher perturbative orders is presently only known approximately. We scrutinise the accuracy of state-of-the-art approximations at three- and four-loop order. At three loops, we present for the first time a result with arbitrary numerical precision for general kinematics and compare to the best Pad\'e estimate. At four loops, we calculate the fourth (inverse) moment of the non-singlet heavy-quark vacuum polarisation in order to test the prediction for this moment based on Pad\'e approximation.
[ { "created": "Tue, 10 Oct 2017 16:52:28 GMT", "version": "v1" }, { "created": "Mon, 9 Apr 2018 15:40:09 GMT", "version": "v2" } ]
2018-04-26
[ [ "Maier", "Andreas", "" ], [ "Marquard", "Peter", "" ] ]
The heavy-quark contribution to the polarisation function $\Pi$ at higher perturbative orders is presently only known approximately. We scrutinise the accuracy of state-of-the-art approximations at three- and four-loop order. At three loops, we present for the first time a result with arbitrary numerical precision for general kinematics and compare to the best Pad\'e estimate. At four loops, we calculate the fourth (inverse) moment of the non-singlet heavy-quark vacuum polarisation in order to test the prediction for this moment based on Pad\'e approximation.
2407.08766
Jun Shi
Jun Shi, Jian Liang and Susan Gardner
Revisiting $C$ and $CP$ Violation in $\eta \to \pi^+\pi^-\pi^0$ Decay
11 pages, 4 figures. Updated version matched to the one submitted to PRD
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The decay $\eta\to \pi^+\pi^-\pi^0$ is an ideal process in which to study flavor-conserving $C$ and $CP$ violation beyond the Standard Model. We deduce the $C$- and $CP$-odd quark operators that contribute to $\eta\to \pi^+\pi^-\pi^0$ originating from the mass-dimension 6 Standard Model effective field theory. The corresponding hadron-level operators that generate a non-vanishing $I=0$ amplitude at order $p^6$ in the chiral effective theory are presented for the first time, in addition to the leading order operatorsascribed to the $I=2$ final state. By fitting the KLOE-2 and the most recent BESIII experimental data, we determine the coefficients of the lowest order $I=0$ and $I=2$ amplitudes and estimate the potential new physics energy scale. We also perform an impact study of the future $\eta\to \pi^+\pi^-\pi^0$ experiments.
[ { "created": "Thu, 11 Jul 2024 09:02:02 GMT", "version": "v1" }, { "created": "Sat, 20 Jul 2024 08:07:12 GMT", "version": "v2" } ]
2024-07-23
[ [ "Shi", "Jun", "" ], [ "Liang", "Jian", "" ], [ "Gardner", "Susan", "" ] ]
The decay $\eta\to \pi^+\pi^-\pi^0$ is an ideal process in which to study flavor-conserving $C$ and $CP$ violation beyond the Standard Model. We deduce the $C$- and $CP$-odd quark operators that contribute to $\eta\to \pi^+\pi^-\pi^0$ originating from the mass-dimension 6 Standard Model effective field theory. The corresponding hadron-level operators that generate a non-vanishing $I=0$ amplitude at order $p^6$ in the chiral effective theory are presented for the first time, in addition to the leading order operatorsascribed to the $I=2$ final state. By fitting the KLOE-2 and the most recent BESIII experimental data, we determine the coefficients of the lowest order $I=0$ and $I=2$ amplitudes and estimate the potential new physics energy scale. We also perform an impact study of the future $\eta\to \pi^+\pi^-\pi^0$ experiments.
hep-ph/9905431
Gela Devidze
Gela G. Devidze
The lowest-order short-distance contribution to the $B_{s}\to\gamma\gamma$ decay
7 pages, latex
null
null
null
hep-ph
null
The complete calculation of the lowest order short-distance contributions to the $B_{s}\to\gamma\gamma$ decay in the SM are presented. The amplitude and branching ratio are calculated.
[ { "created": "Fri, 21 May 1999 05:18:20 GMT", "version": "v1" } ]
2007-05-23
[ [ "Devidze", "Gela G.", "" ] ]
The complete calculation of the lowest order short-distance contributions to the $B_{s}\to\gamma\gamma$ decay in the SM are presented. The amplitude and branching ratio are calculated.
hep-ph/9701202
Antonio Riotto
A. Riotto
What is found upon defrosting the Universe after inflation
Three pages, LaTeX. Talk given at the 18th Texas Symposium on Relativisitc Astrophysics, December 15-20, Chicago, Illinois
null
null
null
hep-ph
null
At the end of inflation the Universe is frozen in a near zero-entropy state with energy density in a coherent scalar field and must be "defrosted" to produce the observed entropy and baryon number. Baryon asymmetry may be generated by the decay of supermassive Grand Unified Theory (GUT) bosons produced non-thermally in a preheating phase after inflation, thus solving many drawbacks facing GUT baryogenesis in the old reheating scenario.
[ { "created": "Thu, 2 Jan 1997 14:52:39 GMT", "version": "v1" } ]
2007-05-23
[ [ "Riotto", "A.", "" ] ]
At the end of inflation the Universe is frozen in a near zero-entropy state with energy density in a coherent scalar field and must be "defrosted" to produce the observed entropy and baryon number. Baryon asymmetry may be generated by the decay of supermassive Grand Unified Theory (GUT) bosons produced non-thermally in a preheating phase after inflation, thus solving many drawbacks facing GUT baryogenesis in the old reheating scenario.
hep-ph/9610253
Lubov Vassilevskaya
N.V. Mikheev, L.A. Vassilevskaya and M.L. Zilberman
Neutrino Radiative Decay in an External Electromagnetic Field via Vector Leptoquark
13 pages, latex. To be published in Phys. Lett. B
Phys.Lett. B390 (1997) 227-233
10.1016/S0370-2693(96)01369-X
YARU-HE-96/03
hep-ph
null
The massive neutrino radiative decay $\nu_i \rightarrow \nu_j \gamma$ ($i \ne j$) is investigated within the Minimal Quark-Lepton Symmetry of the Pati-Salam type based on the $SU(4)_V \times SU(2)_L \times G_R$ group in an external constant crossed field ($\vec {\cal E} \perp \vec H$, ${\cal E}=H$). The matrix element $\Delta M^{(X)}$ and the decay probability $W^{(X)}$ due to the leptoquark $X$ contribution are analysed. The effect of significant enhancement of the neutrino decay by the crossed field takes place. It is shown that the leptoquark contribution to the decay probability can dominate over the $W$-boson one in the case of strong suppression of the lepton mixing in the framework of the SM.
[ { "created": "Sat, 5 Oct 1996 10:57:13 GMT", "version": "v1" } ]
2009-10-28
[ [ "Mikheev", "N. V.", "" ], [ "Vassilevskaya", "L. A.", "" ], [ "Zilberman", "M. L.", "" ] ]
The massive neutrino radiative decay $\nu_i \rightarrow \nu_j \gamma$ ($i \ne j$) is investigated within the Minimal Quark-Lepton Symmetry of the Pati-Salam type based on the $SU(4)_V \times SU(2)_L \times G_R$ group in an external constant crossed field ($\vec {\cal E} \perp \vec H$, ${\cal E}=H$). The matrix element $\Delta M^{(X)}$ and the decay probability $W^{(X)}$ due to the leptoquark $X$ contribution are analysed. The effect of significant enhancement of the neutrino decay by the crossed field takes place. It is shown that the leptoquark contribution to the decay probability can dominate over the $W$-boson one in the case of strong suppression of the lepton mixing in the framework of the SM.
1606.02313
Matthew Schwartz
Matthew D. Schwartz
Precision direct photon spectra at high energy and comparison to the 8 TeV ATLAS data
18 pages, 22 plots, 4 tables
null
10.1007/JHEP09(2016)005
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The direct photon spectrum is computed to the highest currently available precision and compared to ATLAS data from 8 TeV collisions at the LHC. The prediction includes threshold resummation at next-to-next-to-next-to-leading logarithmic order through the program PeTeR, matched to next-to-leading fixed order with fragmentation effects using JetPhox and includes the resummation of leading-logarithmic electroweak Sudakov effects. Remarkably, improved agreement with data can be seen when each component of the calculation is added successively. This comparison demonstrates the importance of both threshold logs and electroweak Sudakov effects. Numerical values for the predictions are included.
[ { "created": "Tue, 7 Jun 2016 20:01:57 GMT", "version": "v1" } ]
2016-09-21
[ [ "Schwartz", "Matthew D.", "" ] ]
The direct photon spectrum is computed to the highest currently available precision and compared to ATLAS data from 8 TeV collisions at the LHC. The prediction includes threshold resummation at next-to-next-to-next-to-leading logarithmic order through the program PeTeR, matched to next-to-leading fixed order with fragmentation effects using JetPhox and includes the resummation of leading-logarithmic electroweak Sudakov effects. Remarkably, improved agreement with data can be seen when each component of the calculation is added successively. This comparison demonstrates the importance of both threshold logs and electroweak Sudakov effects. Numerical values for the predictions are included.
1503.04557
Hiroshi Okada
Hiroshi Okada
Two Loop Radiative Seesaw and X-ray line Dark Matter with Global U(1) Symmetry
18 pages, 5 figures, 1 table; modified version. arXiv admin note: text overlap with arXiv:1407.2543
null
null
KIAS-P15013
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study a two loop induced radiative neutrino model with global $U(1)$ symmetry at 1 GeV scale, in which we explain the X-ray line at 7.1 keV of dark matter candidate reported by XMN-Newton X-ray observatory using data of various galaxy clusters and Andromeda galaxy. We also discuss Higgs sector, lepton flavor violation processes, and a physical Goldstone boson.
[ { "created": "Mon, 16 Mar 2015 08:11:58 GMT", "version": "v1" }, { "created": "Wed, 21 Oct 2015 17:24:25 GMT", "version": "v2" } ]
2015-11-19
[ [ "Okada", "Hiroshi", "" ] ]
We study a two loop induced radiative neutrino model with global $U(1)$ symmetry at 1 GeV scale, in which we explain the X-ray line at 7.1 keV of dark matter candidate reported by XMN-Newton X-ray observatory using data of various galaxy clusters and Andromeda galaxy. We also discuss Higgs sector, lepton flavor violation processes, and a physical Goldstone boson.
2102.01755
Natalia Tapia Arellano
Natalia Tapia Arellano, Shunsaku Horiuchi
Measuring solar neutrinos over Gigayear timescales with Paleo Detectors
9 pages, 7 figures
Phys. Rev. D 103, 123016 (2021)
10.1103/PhysRevD.103.123016
null
hep-ph astro-ph.HE astro-ph.IM astro-ph.SR hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Measuring the solar neutrino flux over gigayear timescales could provide a new window to inform the Solar Standard Model as well as studies of the Earth's long-term climate. We demonstrate the feasibility of measuring the time-evolution of the $^8$B solar neutrino flux over gigayear timescales using paleo detectors, naturally occurring minerals which record neutrino-induced recoil tracks over geological times. We explore suitable minerals and identify track lengths of 15--30 nm to be a practical window to detect the $^8$B solar neutrino flux. A collection of ultra-radiopure minerals of different ages, each some 0.1 kg by mass, can be used to probe the rise of the $^8$B solar neutrino flux over the recent gigayear of the Sun's evolution. We also show that models of the solar abundance problem can be distinguished based on the time-integrated tracks induced by the $^8$B solar neutrino flux.
[ { "created": "Tue, 2 Feb 2021 21:09:31 GMT", "version": "v1" }, { "created": "Thu, 4 Mar 2021 15:44:53 GMT", "version": "v2" } ]
2021-06-23
[ [ "Arellano", "Natalia Tapia", "" ], [ "Horiuchi", "Shunsaku", "" ] ]
Measuring the solar neutrino flux over gigayear timescales could provide a new window to inform the Solar Standard Model as well as studies of the Earth's long-term climate. We demonstrate the feasibility of measuring the time-evolution of the $^8$B solar neutrino flux over gigayear timescales using paleo detectors, naturally occurring minerals which record neutrino-induced recoil tracks over geological times. We explore suitable minerals and identify track lengths of 15--30 nm to be a practical window to detect the $^8$B solar neutrino flux. A collection of ultra-radiopure minerals of different ages, each some 0.1 kg by mass, can be used to probe the rise of the $^8$B solar neutrino flux over the recent gigayear of the Sun's evolution. We also show that models of the solar abundance problem can be distinguished based on the time-integrated tracks induced by the $^8$B solar neutrino flux.
1910.01637
Andrew Buckley
Andy Buckley, Deepak Kar, Karl Nordstrom
Fast simulation of detector effects in Rivet
null
SciPost Phys. 8, 025 (2020)
10.21468/SciPostPhys.8.2.025
MCNET-19-22
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We describe the design and implementation of detector-bias emulation in the Rivet MC event analysis system. Implemented using C++ efficiency and kinematic smearing functors, it allows detector effects to be specified within an analysis routine, customised to the exact phase-space and reconstruction working points of the analysis. A set of standard detector functions for the physics objects of Runs 1 and 2 of the ATLAS and CMS experiments is also provided. Finally, as jet substructure is an important class of physics observable usually considered to require an explicit detector simulation, we demonstrate that a smearing approach, tuned to available substructure data and implemented in Rivet, can accurately reproduce jet-structure biases observed by ATLAS.
[ { "created": "Thu, 3 Oct 2019 17:56:35 GMT", "version": "v1" }, { "created": "Fri, 20 Dec 2019 18:18:41 GMT", "version": "v2" }, { "created": "Mon, 23 Dec 2019 10:28:53 GMT", "version": "v3" } ]
2020-02-12
[ [ "Buckley", "Andy", "" ], [ "Kar", "Deepak", "" ], [ "Nordstrom", "Karl", "" ] ]
We describe the design and implementation of detector-bias emulation in the Rivet MC event analysis system. Implemented using C++ efficiency and kinematic smearing functors, it allows detector effects to be specified within an analysis routine, customised to the exact phase-space and reconstruction working points of the analysis. A set of standard detector functions for the physics objects of Runs 1 and 2 of the ATLAS and CMS experiments is also provided. Finally, as jet substructure is an important class of physics observable usually considered to require an explicit detector simulation, we demonstrate that a smearing approach, tuned to available substructure data and implemented in Rivet, can accurately reproduce jet-structure biases observed by ATLAS.
1901.00309
Saleh Sultansoy
Saleh Sultansoy
Energy frontier lepton-hadron colliders, vector-like quarks and leptons, preons and so on
6 pages, Input to the European Particle Physics Strategy Update
null
null
null
hep-ph hep-ex physics.acc-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
First of all, an importance of the LHC and FCC based energy frontier lepton-hadron and photon-hadron colliders is emphasised. Then arguments favoring existence of new heavy isosinglet down-type quarks and vector-like isosinglet or isodoublet leptons are presented, following by historical arguments favoring new (preonic) level of matter. The importance of Super-Charm factory and GeV energy proton linac for Turkey national road map is argued. Finally, several recommendations for ESPP2020 are suggested.
[ { "created": "Wed, 2 Jan 2019 09:50:42 GMT", "version": "v1" } ]
2019-01-04
[ [ "Sultansoy", "Saleh", "" ] ]
First of all, an importance of the LHC and FCC based energy frontier lepton-hadron and photon-hadron colliders is emphasised. Then arguments favoring existence of new heavy isosinglet down-type quarks and vector-like isosinglet or isodoublet leptons are presented, following by historical arguments favoring new (preonic) level of matter. The importance of Super-Charm factory and GeV energy proton linac for Turkey national road map is argued. Finally, several recommendations for ESPP2020 are suggested.
hep-ph/9805445
Stefan Dittmaier
Stefan Dittmaier
Weyl-van-der-Waerden formalism for helicity amplitudes of massive particles
24 pages, latex
Phys.Rev.D59:016007,1998
10.1103/PhysRevD.59.016007
CERN-TH/98-143
hep-ph
null
The Weyl-van-der-Waerden spinor technique for calculating helicity amplitudes of massive and massless particles is presented in a form that is particularly well suited to a direct implementation in computer algebra. Moreover, we explain how to exploit discrete symmetries and how to avoid unphysical poles in amplitudes in practice. The efficiency of the formalism is demonstrated by giving explicit compact results for the helicity amplitudes of the processes gamma gamma -> f fbar, f fbar -> gamma gamma gamma, mu^- mu^+ -> f fbar gamma.
[ { "created": "Mon, 25 May 1998 14:58:51 GMT", "version": "v1" } ]
2011-08-11
[ [ "Dittmaier", "Stefan", "" ] ]
The Weyl-van-der-Waerden spinor technique for calculating helicity amplitudes of massive and massless particles is presented in a form that is particularly well suited to a direct implementation in computer algebra. Moreover, we explain how to exploit discrete symmetries and how to avoid unphysical poles in amplitudes in practice. The efficiency of the formalism is demonstrated by giving explicit compact results for the helicity amplitudes of the processes gamma gamma -> f fbar, f fbar -> gamma gamma gamma, mu^- mu^+ -> f fbar gamma.
hep-ph/0012166
Shoichi Kitamura
Shoichi Kitamura, Tadashi Kon and Tetsuro Kobayashi
Single scalar top production with polarized beams in ep collisions at HERA
12 pages, 6 eps figures
Mod.Phys.Lett.A16:947-955,2001
10.1142/S0217732301004091
metro-hs-ph1, AP-SU-00/02
hep-ph
null
From the point of view of the R-parity breaking supersymmetric model, we propose a scalar top (stop) search with longitudinally polarized electron (e-) and positron(e+) beams which will soon be available at the upgraded HERA. Fully polarized e- or e+ beams could produce the stop two times as much as unpolarized beams, while they increase background events due to the process of the standard model by about 30% in comparison with unpolarized ones. We show that right-handed e+ beams at HERA is efficient to produce the stop in the model. With 1 fb**(-1) of integrated luminosity we estimate reach in the coupling constant lambda'(131) for masses of the stop in the range 160-400 GeV. We can set a 95% confidence-level exclusion limit for lambda'(131) > 0.01-0.05 in the stop mass range of 240-280 GeV if no singal of the stop is observed. We also point out that y(=Q**2/sx) distributions of e+ coming from the stop shows the different behavior from those of the standard model.
[ { "created": "Thu, 14 Dec 2000 07:02:38 GMT", "version": "v1" }, { "created": "Fri, 15 Dec 2000 03:08:34 GMT", "version": "v2" } ]
2011-03-23
[ [ "Kitamura", "Shoichi", "" ], [ "Kon", "Tadashi", "" ], [ "Kobayashi", "Tetsuro", "" ] ]
From the point of view of the R-parity breaking supersymmetric model, we propose a scalar top (stop) search with longitudinally polarized electron (e-) and positron(e+) beams which will soon be available at the upgraded HERA. Fully polarized e- or e+ beams could produce the stop two times as much as unpolarized beams, while they increase background events due to the process of the standard model by about 30% in comparison with unpolarized ones. We show that right-handed e+ beams at HERA is efficient to produce the stop in the model. With 1 fb**(-1) of integrated luminosity we estimate reach in the coupling constant lambda'(131) for masses of the stop in the range 160-400 GeV. We can set a 95% confidence-level exclusion limit for lambda'(131) > 0.01-0.05 in the stop mass range of 240-280 GeV if no singal of the stop is observed. We also point out that y(=Q**2/sx) distributions of e+ coming from the stop shows the different behavior from those of the standard model.
hep-ph/0607150
Eliecer Hernandez-Gajate
E. Hernandez, J. Nieves, and J.M. Verde-Velasco
Study of exclusive semileptonic and nonleptonic decays of $B_c^-$ in a nonrelativistic quark model
41 latex pages, 14 figures, 21 tables.Version accepted for publication in Phys. Rev. D
Phys.Rev.D74:074008,2006
10.1103/PhysRevD.74.074008
null
hep-ph nucl-th
null
We present results for different observables measured in semileptonic and non-leptonic decays of the $B_c^-$ meson. The calculations have been done within the framework of a nonrelativistic constituent quark model. In order to check the sensitivity of all our results against the inter-quark interaction we use five different quark--quark potentials. We obtain form factors, decay widths and asymmetry parameters for semileptonic $B_c^-\to c\bar c$ and $B_c^-\to \bar B$ decays. In the limit of infinite heavy quark mass our model reproduces the constraints of heavy quark spin symmetry. For the actual heavy quark masses we find nonetheless large corrections to that limiting situation for some form factors. We also analyze exclusive non-leptonic two--meson decay channels within the factorization approximation.
[ { "created": "Thu, 13 Jul 2006 10:00:23 GMT", "version": "v1" }, { "created": "Wed, 9 Aug 2006 15:46:47 GMT", "version": "v2" }, { "created": "Wed, 18 Oct 2006 10:18:53 GMT", "version": "v3" } ]
2008-11-26
[ [ "Hernandez", "E.", "" ], [ "Nieves", "J.", "" ], [ "Verde-Velasco", "J. M.", "" ] ]
We present results for different observables measured in semileptonic and non-leptonic decays of the $B_c^-$ meson. The calculations have been done within the framework of a nonrelativistic constituent quark model. In order to check the sensitivity of all our results against the inter-quark interaction we use five different quark--quark potentials. We obtain form factors, decay widths and asymmetry parameters for semileptonic $B_c^-\to c\bar c$ and $B_c^-\to \bar B$ decays. In the limit of infinite heavy quark mass our model reproduces the constraints of heavy quark spin symmetry. For the actual heavy quark masses we find nonetheless large corrections to that limiting situation for some form factors. We also analyze exclusive non-leptonic two--meson decay channels within the factorization approximation.
0810.4234
Armen Oganesian Gourgenovitcv
B.L.Ioffe
Spontaneous violation of chiral symmetry in QCD vacuum is the origin of baryon masses and determines baryon magnetic moments and their other static properties
13 pades, 5 figures. Dedicated to 85-birthday of acad. S.T.Belyaev. To be published in Phys.At.Nucl. Few references are corrected
Phys.Atom.Nucl.72:1214-1221,2009
10.1134/S1063778809070151
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A short review is presented of the spontaneous violation of chiral symmetry in QCD vacuum. It is demonstrated, that this phenomenon is the origin of baryon masses in QCD. The value of nucleon mass is calculated as well as the masses of hyperons and some baryonic resonances and expressed mainly through the values of quark condensates -- $<0\mid \bar{q} q \mid 0>, ~q=u,d,s$ -- the vacuum expectation values (v.e.v.) of quark field. The concept of vacuum expectation values induced by external fields is introduced. It is demonstrated that such v.e.v. induced by static electromagnetic field results in quark condensate magnetic susceptibility, which plays the main role in determination of baryon magnetic moments. The magnetic moments of proton, neutron and hyperons are calculated. The results of calculation of baryon octet $\beta$-decay constants are also presented.
[ { "created": "Thu, 23 Oct 2008 08:51:52 GMT", "version": "v1" }, { "created": "Thu, 30 Oct 2008 10:18:58 GMT", "version": "v2" }, { "created": "Tue, 16 Dec 2008 11:23:25 GMT", "version": "v3" } ]
2010-04-15
[ [ "Ioffe", "B. L.", "" ] ]
A short review is presented of the spontaneous violation of chiral symmetry in QCD vacuum. It is demonstrated, that this phenomenon is the origin of baryon masses in QCD. The value of nucleon mass is calculated as well as the masses of hyperons and some baryonic resonances and expressed mainly through the values of quark condensates -- $<0\mid \bar{q} q \mid 0>, ~q=u,d,s$ -- the vacuum expectation values (v.e.v.) of quark field. The concept of vacuum expectation values induced by external fields is introduced. It is demonstrated that such v.e.v. induced by static electromagnetic field results in quark condensate magnetic susceptibility, which plays the main role in determination of baryon magnetic moments. The magnetic moments of proton, neutron and hyperons are calculated. The results of calculation of baryon octet $\beta$-decay constants are also presented.
hep-ph/9705469
Tuomas P. Multamki
Tuomas P. Multamaki and Iiro Vilja
CP-Violation and Baryogenesis in The Low Energy Minimal Supersymmetric Standard Model
8 pages(LaTex), 2 figures
Phys.Lett. B411 (1997) 301-305
10.1016/S0370-2693(97)01012-5
TURKU-FL-P26-97
hep-ph
null
In the context of the minimal supersymmetric extension of the Standard Model the effect of a realistic wall profile is studied. It has been recently showed that in the presence of light stops the electroweak scale phase transition can be strong enough for baryogenesis. In the presence of non-trivial CP-violating phases of left-handed mixing terms and Higgsino mass, the largest $n_B/s$ is created when Higgsino and gaugino mass parameters are degenerate, $\mu = M_2$. In the present paper we show that realistic wall profiles suppress the generated baryon number of the universe, so that quite a stringent bound $|\sin\phi_\mu | \gsim 0.2$ for $\mu$-phase $\phi_\mu$ can be inferred.
[ { "created": "Fri, 30 May 1997 06:37:41 GMT", "version": "v1" } ]
2009-10-30
[ [ "Multamaki", "Tuomas P.", "" ], [ "Vilja", "Iiro", "" ] ]
In the context of the minimal supersymmetric extension of the Standard Model the effect of a realistic wall profile is studied. It has been recently showed that in the presence of light stops the electroweak scale phase transition can be strong enough for baryogenesis. In the presence of non-trivial CP-violating phases of left-handed mixing terms and Higgsino mass, the largest $n_B/s$ is created when Higgsino and gaugino mass parameters are degenerate, $\mu = M_2$. In the present paper we show that realistic wall profiles suppress the generated baryon number of the universe, so that quite a stringent bound $|\sin\phi_\mu | \gsim 0.2$ for $\mu$-phase $\phi_\mu$ can be inferred.
1005.1282
Christopher Kolda
Antonio Delgado, Christopher Kolda, J. Pocahontas Olson and Alejandro de la Puente (University of Notre Dame)
The SUSY Higgs Mass: the Singlet Saves the Day
8 pages, 2 figures
Phys.Rev.Lett.105:091802,2010
10.1103/PhysRevLett.105.091802
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a generalization of the Next-to-Minimal Supersymmetric Standard Model (NMSSM), with an explicit mu-term and a supersymmetric mass for the singlet superfield, as a route to alleviating the little hierarchy problem of the Minimal Supersymmetric Standard Model (MSSM). Though this model does not address the mu-problem of the MSSM, we are able to generate masses for the lightest neutral Higgs boson up to 140 GeV with top squarks below the TeV scale, all couplings perturbative to the gauge unification scale, and with no need to fine tune parameters in the scalar potential. This model, which we call the S-MSSM, more closely resembles the MSSM phenomenologically than the NMSSM as usually defined.
[ { "created": "Fri, 7 May 2010 19:47:46 GMT", "version": "v1" } ]
2014-11-21
[ [ "Delgado", "Antonio", "", "University of Notre Dame" ], [ "Kolda", "Christopher", "", "University of Notre Dame" ], [ "Olson", "J. Pocahontas", "", "University of Notre Dame" ], [ "de la Puente", "Alejandro", "", "University of Notre Dame" ] ]
We present a generalization of the Next-to-Minimal Supersymmetric Standard Model (NMSSM), with an explicit mu-term and a supersymmetric mass for the singlet superfield, as a route to alleviating the little hierarchy problem of the Minimal Supersymmetric Standard Model (MSSM). Though this model does not address the mu-problem of the MSSM, we are able to generate masses for the lightest neutral Higgs boson up to 140 GeV with top squarks below the TeV scale, all couplings perturbative to the gauge unification scale, and with no need to fine tune parameters in the scalar potential. This model, which we call the S-MSSM, more closely resembles the MSSM phenomenologically than the NMSSM as usually defined.
hep-ph/9504384
Joannis Papavassiliou
Joannis Papavassiliou
RECENT DEVELOPMENTS IN THE PINCH TECHNIQUE
15 pages Latex, all special macros included. To appear in the proceedings of the Ringberg Workshop on "Perspectives for electroweak interactions in e^+e^- collisions" hosted by the Max Planck Institut, at the Ringberg Castle, Munich, February 5-8, 1995. Edited by B. Kniehl
null
null
null
hep-ph
null
Some of the most important theoretical and phenomenological aspects of the pinch technique are presented, and several recent developments are briefly reviewed.
[ { "created": "Mon, 24 Apr 1995 20:59:29 GMT", "version": "v1" } ]
2007-05-23
[ [ "Papavassiliou", "Joannis", "" ] ]
Some of the most important theoretical and phenomenological aspects of the pinch technique are presented, and several recent developments are briefly reviewed.
2107.02047
Zhan Sun
Zhan Sun
Next-to-leading-order study of $J/\psi$ angular distributions in $e^{+}e^{-} \to J/\psi+\eta_c,\chi_{cJ}$ at $\sqrt{s} \approx 10.6$ GeV
14 pages, 4 figures, and 7 tables; accepted for publication in JHEP
JHEP 09 (2021) 073
10.1007/JHEP09(2021)073
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this paper, we present a detailed next-to-leading-order (NLO) study of $J/\psi$ angular distributions in $e^{+}e^{-} \to J/\psi+\eta_c,\chi_{cJ}$ ($J=0,1,2$) within the nonrelativistic QCD factorization (NRQCD). The numerical NLO expressions for total and differential cross sections, i.e., $\frac{d\sigma}{d\cos\theta}=A+B\cos^2\theta$, are both derived. With the inclusion of the newly-calculated QCD corrections to $A$ and $B$, the $\alpha_{\theta}(= B/A)$ parameters in $J/\psi+\chi_{c0}$ and $J/\psi+\chi_{c1}$ are moderately enhanced, while the magnitude of ${\alpha_\theta}_{J/\psi+\chi_{c2}}$ is significantly reduced; regarding the production of $J/\psi+\eta_c$, the $\alpha_\theta$ value remains unchanged. By comparing with experiment, we find the predicted ${\alpha_\theta}_{J/\psi+\eta_c}$ is in good agreement with the $\textrm{B}\scriptsize{\textrm{ELLE}}$ measurement; however, ${\alpha_\theta}_{J/\psi+\chi_{c0}}$ is still totally incompatible with the experimental result, and this discrepancy seems to hardly be cured by proper choices of the charm-quark mass, the renormalization scale, and the NRQCD matrix elements.
[ { "created": "Mon, 5 Jul 2021 14:19:31 GMT", "version": "v1" }, { "created": "Sat, 28 Aug 2021 08:23:31 GMT", "version": "v2" } ]
2021-09-15
[ [ "Sun", "Zhan", "" ] ]
In this paper, we present a detailed next-to-leading-order (NLO) study of $J/\psi$ angular distributions in $e^{+}e^{-} \to J/\psi+\eta_c,\chi_{cJ}$ ($J=0,1,2$) within the nonrelativistic QCD factorization (NRQCD). The numerical NLO expressions for total and differential cross sections, i.e., $\frac{d\sigma}{d\cos\theta}=A+B\cos^2\theta$, are both derived. With the inclusion of the newly-calculated QCD corrections to $A$ and $B$, the $\alpha_{\theta}(= B/A)$ parameters in $J/\psi+\chi_{c0}$ and $J/\psi+\chi_{c1}$ are moderately enhanced, while the magnitude of ${\alpha_\theta}_{J/\psi+\chi_{c2}}$ is significantly reduced; regarding the production of $J/\psi+\eta_c$, the $\alpha_\theta$ value remains unchanged. By comparing with experiment, we find the predicted ${\alpha_\theta}_{J/\psi+\eta_c}$ is in good agreement with the $\textrm{B}\scriptsize{\textrm{ELLE}}$ measurement; however, ${\alpha_\theta}_{J/\psi+\chi_{c0}}$ is still totally incompatible with the experimental result, and this discrepancy seems to hardly be cured by proper choices of the charm-quark mass, the renormalization scale, and the NRQCD matrix elements.
1408.1161
Howard Georgi
Howard Georgi
A Simple Alternative to Jet-Clustering Algorithms
7 pages, 0 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I describe a class of iterative jet algorithms that are based on maximizing a fixed function of the total 4-momentum rather than clustering of pairs of jets. I describe some of the properties of the simplest examples of this class, appropriate for jets at an $e^+e^-$ machine. These examples are sufficiently simple that many features of the jets that they define can be determined analytically with ease. The jets constructed in this way have some potentially useful properties, including a strong form of infrared safety.
[ { "created": "Wed, 6 Aug 2014 01:51:46 GMT", "version": "v1" }, { "created": "Sun, 31 Aug 2014 10:32:34 GMT", "version": "v2" } ]
2014-09-02
[ [ "Georgi", "Howard", "" ] ]
I describe a class of iterative jet algorithms that are based on maximizing a fixed function of the total 4-momentum rather than clustering of pairs of jets. I describe some of the properties of the simplest examples of this class, appropriate for jets at an $e^+e^-$ machine. These examples are sufficiently simple that many features of the jets that they define can be determined analytically with ease. The jets constructed in this way have some potentially useful properties, including a strong form of infrared safety.
1211.6773
Markus Wobisch
M. Wobisch, K. Chakravarthula, R. Dhullipudi, L. Sawyer, M. Tamsett
A new quantity for studies of dijet azimuthal decorrelations
20 pages, 11 figures, 1 table, submitted to JHEP
JHEP 01 (2013) 172
10.1007/JHEP01(2013)172
FERMILAB-PUB-12-618-E
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce a new measurable quantity, $R_{\Delta \phi}$, for studies of the rapidity and transverse momentum dependence of dijet azimuthal decorrelations in hadron-hadron collisions. In pQCD, $R_{\Delta \phi}$ is computed as a ratio of three-jet and dijet cross sections in which the parton distribution functions cancel to a large extent. At the leading order, $R_{\Delta \phi}$ is proportional to $\alpha_s$, and the transverse momentum dependence of can therefore be exploited to determine $\alpha_s$. We compute the NLO pQCD theory predictions and non-perturbative corrections for $R_{\Delta \phi}$ at the LHC and the Tevatron and investigate the corresponding uncertainties. From this, we estimate the theory uncertainties for $\alpha_s$ determinations based on $R_{\Delta \phi}$ at both colliders. The potential of $R_{\Delta \phi}$ measurements for tuning Monte Carlo event generators is also demonstrated.
[ { "created": "Wed, 28 Nov 2012 22:49:51 GMT", "version": "v1" }, { "created": "Fri, 30 Nov 2012 15:54:59 GMT", "version": "v2" } ]
2021-12-01
[ [ "Wobisch", "M.", "" ], [ "Chakravarthula", "K.", "" ], [ "Dhullipudi", "R.", "" ], [ "Sawyer", "L.", "" ], [ "Tamsett", "M.", "" ] ]
We introduce a new measurable quantity, $R_{\Delta \phi}$, for studies of the rapidity and transverse momentum dependence of dijet azimuthal decorrelations in hadron-hadron collisions. In pQCD, $R_{\Delta \phi}$ is computed as a ratio of three-jet and dijet cross sections in which the parton distribution functions cancel to a large extent. At the leading order, $R_{\Delta \phi}$ is proportional to $\alpha_s$, and the transverse momentum dependence of can therefore be exploited to determine $\alpha_s$. We compute the NLO pQCD theory predictions and non-perturbative corrections for $R_{\Delta \phi}$ at the LHC and the Tevatron and investigate the corresponding uncertainties. From this, we estimate the theory uncertainties for $\alpha_s$ determinations based on $R_{\Delta \phi}$ at both colliders. The potential of $R_{\Delta \phi}$ measurements for tuning Monte Carlo event generators is also demonstrated.
hep-ph/9903404
Georg Weiglein
S. Heinemeyer, W. Hollik, G. Weiglein
The Mass of the Lightest MSSM Higgs Boson: A Compact Analytical Expression at the Two-Loop Level
14 pages, 4 figures
Phys.Lett. B455 (1999) 179-191
10.1016/S0370-2693(99)00417-7
CERN-TH/99-74, DESY 99-012, KA-TP-1-1999
hep-ph
null
A compact approximation formula for the mass of the lightest neutral CP-even Higgs boson, m_h, in the Minimal Supersymmetric Standard Model (MSSM) is derived from the diagrammatic two-loop result for m_h up to O(alpha alpha_s). By analytically expanding the diagrammatic result the leading logarithmic and non-logarithmic as well as the dominant subleading contributions are obtained. The approximation formula is valid for general mixing in the scalar top sector and arbitrary choices of the parameters in the Higgs sector of the model. Its quality is analyzed by comparing it with the full diagrammatic result. We find agreement with the full result better than 2 GeV for most parts of the MSSM parameter space.
[ { "created": "Thu, 18 Mar 1999 20:06:00 GMT", "version": "v1" } ]
2009-10-31
[ [ "Heinemeyer", "S.", "" ], [ "Hollik", "W.", "" ], [ "Weiglein", "G.", "" ] ]
A compact approximation formula for the mass of the lightest neutral CP-even Higgs boson, m_h, in the Minimal Supersymmetric Standard Model (MSSM) is derived from the diagrammatic two-loop result for m_h up to O(alpha alpha_s). By analytically expanding the diagrammatic result the leading logarithmic and non-logarithmic as well as the dominant subleading contributions are obtained. The approximation formula is valid for general mixing in the scalar top sector and arbitrary choices of the parameters in the Higgs sector of the model. Its quality is analyzed by comparing it with the full diagrammatic result. We find agreement with the full result better than 2 GeV for most parts of the MSSM parameter space.
hep-ph/0204126
Efrain J. Ferrer
J. Cannellos, E. J. Ferrer, and V. de la Incera
Hypermagnetic Field Effects in the Thermal Bath of Chiral Fermions
5 pages
Phys.Lett. B542 (2002) 123-129
10.1016/S0370-2693(02)02336-5
null
hep-ph
null
The dispersion relations for leptons in the symmetric phase of the electroweak model in the presence of a constant hypermagnetic field are investigated. The one-loop fermion self-energies are calculated in the lowest Landau level approximation and used to show that the hypermagnetic field forbids the generation of the ''effective mass'' found as a pole of the fermions' propagators at high temperature and zero fields. In the considered approximation leptons behave as massless particles propagating only along the direction of the external field. The reported results can be of interest for the cosmological implications of primordial hypermagnetic fields.
[ { "created": "Thu, 11 Apr 2002 14:05:59 GMT", "version": "v1" }, { "created": "Sat, 6 Jul 2002 15:05:51 GMT", "version": "v2" } ]
2015-06-25
[ [ "Cannellos", "J.", "" ], [ "Ferrer", "E. J.", "" ], [ "de la Incera", "V.", "" ] ]
The dispersion relations for leptons in the symmetric phase of the electroweak model in the presence of a constant hypermagnetic field are investigated. The one-loop fermion self-energies are calculated in the lowest Landau level approximation and used to show that the hypermagnetic field forbids the generation of the ''effective mass'' found as a pole of the fermions' propagators at high temperature and zero fields. In the considered approximation leptons behave as massless particles propagating only along the direction of the external field. The reported results can be of interest for the cosmological implications of primordial hypermagnetic fields.
1510.07746
Atsushi Watanabe
Takehiko Asaka, Atsushi Watanabe
Probing heavy neutrinos in the COMET experiment
8 pages, 3 figures
null
10.1093/ptep/ptw011
MISC-2015-04
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We argue that the COMET experiment --- a dedicated experiment for the $\mu$-$e$ conversion search --- can be a powerful facility to search for heavy neutrinos in the mass range $1\,{\rm MeV} \lesssim M \lesssim 100\,{\rm MeV}$. The stopped muons captured by the target nuclei or decaying in orbit are efficiently produce heavy neutrinos via the active-sterile mixing. The produced heavy neutrinos then decay to electron-positron pair (plus an active neutrino), which events are clearly seen by the cylindrical drift chamber surrounding the target. The expected sensitivity is comparable to the PS191 bound when the COMET experiment achieves $\sim 10^{17}$ stopping muons in the target.
[ { "created": "Tue, 27 Oct 2015 01:29:05 GMT", "version": "v1" } ]
2016-03-16
[ [ "Asaka", "Takehiko", "" ], [ "Watanabe", "Atsushi", "" ] ]
We argue that the COMET experiment --- a dedicated experiment for the $\mu$-$e$ conversion search --- can be a powerful facility to search for heavy neutrinos in the mass range $1\,{\rm MeV} \lesssim M \lesssim 100\,{\rm MeV}$. The stopped muons captured by the target nuclei or decaying in orbit are efficiently produce heavy neutrinos via the active-sterile mixing. The produced heavy neutrinos then decay to electron-positron pair (plus an active neutrino), which events are clearly seen by the cylindrical drift chamber surrounding the target. The expected sensitivity is comparable to the PS191 bound when the COMET experiment achieves $\sim 10^{17}$ stopping muons in the target.
hep-ph/0601262
Jared Kaplan
Jared Kaplan
Dark Matter Generation and Split Supersymmetry
V1: 14 p, 1 fig; V2: 19 p, 1 fig, significant additions, references added V3: Matching JHEP
JHEP 0610:065,2006
10.1088/1126-6708/2006/10/065
null
hep-ph
null
We analyze a simple Split Supersymmetry scenario where fermion masses come from anomaly mediation, yielding m_s ~ 1000 TeV, m_{3/2} ~ 100 TeV, and m_f ~ 1 TeV. We consider non-thermal dark matter production in the presence of moduli, and we find that the decay chains of moduli to LSPs and moduli to gravitinos to LSPs generate dark matter more efficiently than perturbative freeze-out, allowing for a light, LHC visible spectrum. These decaying moduli can also weaken cosmological constraints on the axion decay constant. With squark masses of order 1000 TeV, LHC gluinos will decay millimeters from their primary vertices, resulting in a striking experimental signature, and the suppression of Flavor Changing Neutral Currents is almost sufficient to allow arbitrary mixing in squark mass matrices.
[ { "created": "Tue, 31 Jan 2006 05:27:16 GMT", "version": "v1" }, { "created": "Sat, 22 Jul 2006 23:30:44 GMT", "version": "v2" }, { "created": "Thu, 30 Nov 2006 16:55:04 GMT", "version": "v3" } ]
2010-02-03
[ [ "Kaplan", "Jared", "" ] ]
We analyze a simple Split Supersymmetry scenario where fermion masses come from anomaly mediation, yielding m_s ~ 1000 TeV, m_{3/2} ~ 100 TeV, and m_f ~ 1 TeV. We consider non-thermal dark matter production in the presence of moduli, and we find that the decay chains of moduli to LSPs and moduli to gravitinos to LSPs generate dark matter more efficiently than perturbative freeze-out, allowing for a light, LHC visible spectrum. These decaying moduli can also weaken cosmological constraints on the axion decay constant. With squark masses of order 1000 TeV, LHC gluinos will decay millimeters from their primary vertices, resulting in a striking experimental signature, and the suppression of Flavor Changing Neutral Currents is almost sufficient to allow arbitrary mixing in squark mass matrices.
hep-ph/0308305
Dilip Kumar Ghosh
C. Dariescu, M.A. Dariescu, N.G. Deshpande, Dilip Kumar Ghosh
CP violating SUSY effects in Penguin dominated modes B -> PHI K and B -> PHI K*
21 pages, Latex, 2 postscript figures. Comments on B_s mixing is added. Typos are corrected in the text and figure label. Figure 1 is corrected. More references are added. Version to be published in Phys. Rev. D
Phys.Rev.D69:112003,2004
10.1103/PhysRevD.69.112003
null
hep-ph
null
Recent measurement of time dependent asymmetries in $B \to \phi K$ are indicative of a new source of CP violation. We examine squark mixing in SUSY as this new source, and using QCD improved factorization method to describe $B \to \phi K $ decay, find the allowed range of parameter space for $\rho$ and $\psi $, the magnitude and phase of the down type LR(RL) squark mixing parameter $\delta^{bs}_{LR(RL)}$. We then study $B \to \phi K^{*}$ and calculate the expected CP asymmetries in the same range of parameter space. We find that this asymmetry is in the range 15% to $20% $ for acceptable value of $B \to phi K^{*}$ branching ratio. We also predict the helicity dependent CP asymmetries in the same parameter space.
[ { "created": "Thu, 28 Aug 2003 22:48:25 GMT", "version": "v1" }, { "created": "Tue, 23 Sep 2003 20:53:44 GMT", "version": "v2" }, { "created": "Wed, 23 Jun 2004 19:21:35 GMT", "version": "v3" } ]
2014-11-17
[ [ "Dariescu", "C.", "" ], [ "Dariescu", "M. A.", "" ], [ "Deshpande", "N. G.", "" ], [ "Ghosh", "Dilip Kumar", "" ] ]
Recent measurement of time dependent asymmetries in $B \to \phi K$ are indicative of a new source of CP violation. We examine squark mixing in SUSY as this new source, and using QCD improved factorization method to describe $B \to \phi K $ decay, find the allowed range of parameter space for $\rho$ and $\psi $, the magnitude and phase of the down type LR(RL) squark mixing parameter $\delta^{bs}_{LR(RL)}$. We then study $B \to \phi K^{*}$ and calculate the expected CP asymmetries in the same range of parameter space. We find that this asymmetry is in the range 15% to $20% $ for acceptable value of $B \to phi K^{*}$ branching ratio. We also predict the helicity dependent CP asymmetries in the same parameter space.
hep-ph/0604084
Akaki Rusetsky
Gilberto Colangelo (University of Bern), Juerg Gasser (University of Bern), Bastian Kubis (University of Bonn), Akaki Rusetsky (University of Bonn and Tbilisi State University)
Cusps in K --> 3 pi decays
14 pages, 3 figures, uses Elsevier style
Phys.Lett.B638:187-194,2006
10.1016/j.physletb.2006.05.017
preprint HISKP-TH-06/09 (University of Bonn)
hep-ph
null
The pion mass difference generates a pronounced cusp in K --> 3 pi decays. As has recently been pointed out by Cabibbo and Isidori, an accurate measurement of the cusp may allow one to pin down the S-wave pi pi scattering lengths to high precision. Here, we present and illustrate an effective field theory framework that allows one to determine the structure of this cusp in a straightforward manner. The strictures imposed by analyticity and unitarity are respected automatically.
[ { "created": "Mon, 10 Apr 2006 18:07:47 GMT", "version": "v1" } ]
2008-11-26
[ [ "Colangelo", "Gilberto", "", "University of Bern" ], [ "Gasser", "Juerg", "", "University of\n Bern" ], [ "Kubis", "Bastian", "", "University of Bonn" ], [ "Rusetsky", "Akaki", "", "University of Bonn\n and Tbilisi State University" ] ]
The pion mass difference generates a pronounced cusp in K --> 3 pi decays. As has recently been pointed out by Cabibbo and Isidori, an accurate measurement of the cusp may allow one to pin down the S-wave pi pi scattering lengths to high precision. Here, we present and illustrate an effective field theory framework that allows one to determine the structure of this cusp in a straightforward manner. The strictures imposed by analyticity and unitarity are respected automatically.
1906.04186
Yiannis Makris
Yiannis Makris and Ivan Vitev
An Effective Theory of Quarkonia in QCD Matter
38 pages, 5 figures
null
10.1007/JHEP10(2019)111
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
For heavy quarkonia of moderate energy, we generalize the relevant successful theory, non-relativistic Quantum Chromodynamics (NRQCD), to include interactions in nuclear matter. The new resulting theory, NRQCD with Glauber gluons, provides for the first time a universal microscopic description of the interaction of heavy quarkonia with a strongly interacting medium, consistently applicable to a range of phases, such as cold nuclear matter, dense hadron gas, and quark-gluon plasma. The effective field theory we present in this work is derived from first principles and is an important step forward in understanding the common trends in proton-nucleus and nucleus-nucleus data on quarkonium suppression.
[ { "created": "Mon, 10 Jun 2019 18:00:02 GMT", "version": "v1" } ]
2020-01-23
[ [ "Makris", "Yiannis", "" ], [ "Vitev", "Ivan", "" ] ]
For heavy quarkonia of moderate energy, we generalize the relevant successful theory, non-relativistic Quantum Chromodynamics (NRQCD), to include interactions in nuclear matter. The new resulting theory, NRQCD with Glauber gluons, provides for the first time a universal microscopic description of the interaction of heavy quarkonia with a strongly interacting medium, consistently applicable to a range of phases, such as cold nuclear matter, dense hadron gas, and quark-gluon plasma. The effective field theory we present in this work is derived from first principles and is an important step forward in understanding the common trends in proton-nucleus and nucleus-nucleus data on quarkonium suppression.
1512.00954
Gerry McKeon Dr.
D.G.C. McKeon
Renormalization Scheme Dependence in b->u Semileptonic Decays
null
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
After reviewing how the renormalization group equation can be used to sum logarithmic corrections to the decay rate for the semi-leptonic process b->u when using minimal subtraction, we consider renormalization scheme dependence for this calculation when employing this renor- malization scheme. In this calculation, an ambiguity resides in the running strong coupling and in the running b quark mass. The ambiguity usually associated with the renormalization mass scale mu is shown to cancel. It is demonstrated how in one renormalization scheme, there are only leading-log contributions to this decay rate. Another choice of renormalization scheme results in the decay rate being expressed in terms of the two-loop contribution to the beta-function associated with the strong coupling and the one-loop contribution to the anomalous mass dimension as well as a set of renormalization scheme invariant parameters.
[ { "created": "Thu, 3 Dec 2015 05:15:01 GMT", "version": "v1" } ]
2015-12-04
[ [ "McKeon", "D. G. C.", "" ] ]
After reviewing how the renormalization group equation can be used to sum logarithmic corrections to the decay rate for the semi-leptonic process b->u when using minimal subtraction, we consider renormalization scheme dependence for this calculation when employing this renor- malization scheme. In this calculation, an ambiguity resides in the running strong coupling and in the running b quark mass. The ambiguity usually associated with the renormalization mass scale mu is shown to cancel. It is demonstrated how in one renormalization scheme, there are only leading-log contributions to this decay rate. Another choice of renormalization scheme results in the decay rate being expressed in terms of the two-loop contribution to the beta-function associated with the strong coupling and the one-loop contribution to the anomalous mass dimension as well as a set of renormalization scheme invariant parameters.
1707.06042
Grigoris Panotopoulos
Grigoris Panotopoulos and Ilidio Lopes
Constraining the scalar singlet and inert dark matter models using neutron stars
Two-column revtex, 7 pages, 6 figures, to appear in PRD
null
10.1103/PhysRevD.96.023016
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the present work we study the scalar singlet as well as the Two-Higgs Doublet model inert dark matter particles impact on compact objects, and we provide the first constraints of the parameter space using neutron stars. The models discussed here are characterized by two free parameters, namely the mass $M_\chi$ of the scalar particle that plays the role of the dark matter in the Universe, and a dimensionless coupling constant $\lambda_\chi$ that determines the strength of the interaction of the dark matter particles with the Standard Model Higgs boson. By considering a typical neutron star we were able to obtain constraints on scalar dark matter depending on the DM annihilation cross section and self-interaction coupling constant. Our findings show that i) for heavy DM particles neutron stars can provide us with bounds better that the current limits from direct detection searches only when the self-annihilations of DM particles are negligible and the DM self-interaction coupling constant is very small, while ii) for light DM particles the bounds obtained here are comparable to limits from Higgs invisible decays unless the DM particles are extremely light.
[ { "created": "Wed, 19 Jul 2017 12:13:01 GMT", "version": "v1" } ]
2017-09-13
[ [ "Panotopoulos", "Grigoris", "" ], [ "Lopes", "Ilidio", "" ] ]
In the present work we study the scalar singlet as well as the Two-Higgs Doublet model inert dark matter particles impact on compact objects, and we provide the first constraints of the parameter space using neutron stars. The models discussed here are characterized by two free parameters, namely the mass $M_\chi$ of the scalar particle that plays the role of the dark matter in the Universe, and a dimensionless coupling constant $\lambda_\chi$ that determines the strength of the interaction of the dark matter particles with the Standard Model Higgs boson. By considering a typical neutron star we were able to obtain constraints on scalar dark matter depending on the DM annihilation cross section and self-interaction coupling constant. Our findings show that i) for heavy DM particles neutron stars can provide us with bounds better that the current limits from direct detection searches only when the self-annihilations of DM particles are negligible and the DM self-interaction coupling constant is very small, while ii) for light DM particles the bounds obtained here are comparable to limits from Higgs invisible decays unless the DM particles are extremely light.
2202.08350
Teng Ma
Zi-Yu Dong, Teng Ma, Jing Shu, Yu-Hui Zheng
Constructing Generic Effective Field Theory for All Masses and Spins
10 pages, 3 Appendices, 2 figures
Phys. Rev. D 106, 116010 (2022)
10.1103/PhysRevD.106.116010
null
hep-ph
http://creativecommons.org/publicdomain/zero/1.0/
We fully solve the long-standing problem of operator basis construction for fields with any masses and spins. Based on the on-shell method, we propose a novel method to systematically construct a complete set of lowest dimensional amplitude bases at any given dimension through semi-standard Young tableaus of Lorentz subgroup $SU(2)_r$ and global symmetry $U(N)$ ($N$ is the number of external legs), which can be directly mapped into physical operator bases. We first construct a complete set of monomial bases whose dimension is not the lowest and a redundant set of bases that always contains a complete set of amplitude bases with the lowest dimension. Then we decompose the bases of the redundant set into the monomial bases from low to high dimension and eliminate the linear correlation bases. Finally, the bases with the lowest dimension can be picked up. We also propose a matrix projection method to construct the massive amplitude bases involving identical particles. The operator bases of a generic massive effective field theory can be efficiently constructed by the computer programs. A complete set of four-vector operators at dimensions up to six is presented.
[ { "created": "Wed, 16 Feb 2022 21:42:34 GMT", "version": "v1" }, { "created": "Wed, 23 Feb 2022 12:41:08 GMT", "version": "v2" } ]
2022-12-19
[ [ "Dong", "Zi-Yu", "" ], [ "Ma", "Teng", "" ], [ "Shu", "Jing", "" ], [ "Zheng", "Yu-Hui", "" ] ]
We fully solve the long-standing problem of operator basis construction for fields with any masses and spins. Based on the on-shell method, we propose a novel method to systematically construct a complete set of lowest dimensional amplitude bases at any given dimension through semi-standard Young tableaus of Lorentz subgroup $SU(2)_r$ and global symmetry $U(N)$ ($N$ is the number of external legs), which can be directly mapped into physical operator bases. We first construct a complete set of monomial bases whose dimension is not the lowest and a redundant set of bases that always contains a complete set of amplitude bases with the lowest dimension. Then we decompose the bases of the redundant set into the monomial bases from low to high dimension and eliminate the linear correlation bases. Finally, the bases with the lowest dimension can be picked up. We also propose a matrix projection method to construct the massive amplitude bases involving identical particles. The operator bases of a generic massive effective field theory can be efficiently constructed by the computer programs. A complete set of four-vector operators at dimensions up to six is presented.
2405.11820
Arindam Das
Arindam Das, Puja Das, Nobuchika Okada
Testing neutrino mass hierarchy under type-II seesaw scenario in $U(1)_X$ from colliders
14 pages, 7 figures, extended analysis and muon collider corrected
null
null
null
hep-ph
http://creativecommons.org/publicdomain/zero/1.0/
The origin of tiny neutrino mass is a long standing unsolved puzzle of the Standard Model (SM), which allows us to consider scenarios beyond the Standard Model (BSM) in a variety of ways. One of them being a gauge extension of the SM may be realized as in the form of an anomaly free, general $U(1)_X$ extension of the SM, where an $SU(2)_L$ triplet scalar with a $U(1)_X$ charge is introduced to have Dirac Yukawa couplings with the SM lepton doublets. Once the triplet scalar developes a Vacuum Expectation Value (VEV), light neutrinos acquire their tiny Majorana masses. Hence, the decay modes of the triplet scalar has a direct connection to the neutrino oscillation data for different neutrino mass hierarchies. After the breaking of the $U(1)_X$ gauge symmetry, a neutral $U(1)_X$ gauge boson $(Z^\prime)$ acquires mass, which interacts differently with the left and right handed SM fermions. Satisfying the recent LHC bounds on the triplet scalar and $Z^\prime$ boson productions, we study the pair production of the triplet scalar at LHC, 100 TeV proton proton collider FCC, $e^-e^+$ and $\mu^-\mu^+$ colliders followed by its decay into dominant dilepton modes whose flavor structure depend on the neutrino mass hierarchy. Generating the SM backgrounds, we study the possible signal significance of four lepton final states from the triplet scalar pair production. We also compare our results with the purely SM gauge mediated triplet scalar pair production followed by four lepton final states, which could be significant only in $\mu^- \mu^+$ collider.
[ { "created": "Mon, 20 May 2024 06:29:24 GMT", "version": "v1" }, { "created": "Tue, 16 Jul 2024 12:29:43 GMT", "version": "v2" } ]
2024-07-17
[ [ "Das", "Arindam", "" ], [ "Das", "Puja", "" ], [ "Okada", "Nobuchika", "" ] ]
The origin of tiny neutrino mass is a long standing unsolved puzzle of the Standard Model (SM), which allows us to consider scenarios beyond the Standard Model (BSM) in a variety of ways. One of them being a gauge extension of the SM may be realized as in the form of an anomaly free, general $U(1)_X$ extension of the SM, where an $SU(2)_L$ triplet scalar with a $U(1)_X$ charge is introduced to have Dirac Yukawa couplings with the SM lepton doublets. Once the triplet scalar developes a Vacuum Expectation Value (VEV), light neutrinos acquire their tiny Majorana masses. Hence, the decay modes of the triplet scalar has a direct connection to the neutrino oscillation data for different neutrino mass hierarchies. After the breaking of the $U(1)_X$ gauge symmetry, a neutral $U(1)_X$ gauge boson $(Z^\prime)$ acquires mass, which interacts differently with the left and right handed SM fermions. Satisfying the recent LHC bounds on the triplet scalar and $Z^\prime$ boson productions, we study the pair production of the triplet scalar at LHC, 100 TeV proton proton collider FCC, $e^-e^+$ and $\mu^-\mu^+$ colliders followed by its decay into dominant dilepton modes whose flavor structure depend on the neutrino mass hierarchy. Generating the SM backgrounds, we study the possible signal significance of four lepton final states from the triplet scalar pair production. We also compare our results with the purely SM gauge mediated triplet scalar pair production followed by four lepton final states, which could be significant only in $\mu^- \mu^+$ collider.
hep-ph/9906505
Oliver
R. Aleksan, M. Zito, A. Le Yaouanc, L. Oliver, O. Pene and J.-C. Raynal
Inclusive decay of B mesons into $D_s$ or $D^*_s$
30 pages, LaTeX
null
null
LPT-Orsay 99-36, DAPNIA/SPP 99-19
hep-ph
null
We compute the inclusive decay rates $b \to D_s^-(D^{*-}_s) c$ including lowest order QCD corrections on the quark legs, and compare with existing data. Unlike the short distance QCD corrections, that are of higher order, these corrections are of order $\alpha_s$. In the on-shell renormalization scheme and for $\alpha_s(m_b) \cong 0.2$ we find a correction of -10% to the inclusive rate computed using factorization. This gives a total rate $BR(b \to D_s^-(D^{*-}_s)c) \cong 8%$ consistent within $1\sigma$ with the measured value $BR(B \to D_s^{\pm}X) = (10.0 \pm 2.5)%$. The general formulae given here include the case of vanishing mass for the final quark $b \to D_s^-(D_s^{*-})u$. The radiative correction to this rate is -17%. We show in another place that this process can be useful for the measurement of the CKM matrix element $V_{ub}$. We also give the renormalized vertex at the interesting values $q^2 = 0$ and $q^2 = q_{max}^2$, and compare with existing literature.
[ { "created": "Fri, 25 Jun 1999 16:33:21 GMT", "version": "v1" }, { "created": "Tue, 6 Jul 1999 19:56:46 GMT", "version": "v2" }, { "created": "Thu, 8 Jul 1999 19:55:10 GMT", "version": "v3" } ]
2016-09-06
[ [ "Aleksan", "R.", "" ], [ "Zito", "M.", "" ], [ "Yaouanc", "A. Le", "" ], [ "Oliver", "L.", "" ], [ "Pene", "O.", "" ], [ "Raynal", "J. -C.", "" ] ]
We compute the inclusive decay rates $b \to D_s^-(D^{*-}_s) c$ including lowest order QCD corrections on the quark legs, and compare with existing data. Unlike the short distance QCD corrections, that are of higher order, these corrections are of order $\alpha_s$. In the on-shell renormalization scheme and for $\alpha_s(m_b) \cong 0.2$ we find a correction of -10% to the inclusive rate computed using factorization. This gives a total rate $BR(b \to D_s^-(D^{*-}_s)c) \cong 8%$ consistent within $1\sigma$ with the measured value $BR(B \to D_s^{\pm}X) = (10.0 \pm 2.5)%$. The general formulae given here include the case of vanishing mass for the final quark $b \to D_s^-(D_s^{*-})u$. The radiative correction to this rate is -17%. We show in another place that this process can be useful for the measurement of the CKM matrix element $V_{ub}$. We also give the renormalized vertex at the interesting values $q^2 = 0$ and $q^2 = q_{max}^2$, and compare with existing literature.
2404.14264
Pralay Chakraborty
Pralay Chakraborty, Tanmay Dev, Subhankar Roy
Two New $\mu-\tau$ Deviated Neutrino Mass Matrix Textures
null
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We propose two new neutrino mass matrix textures deviating from $\mu-\tau$ symmetry and explore their phenomenological implications. Both textures predict $\theta_{23}$ and $\delta$ within sharp bounds while considering both normal and inverted ordering of neutrino masses. We try to realize these proposed textures within the framework of the seesaw mechanism, in association with the $SU(2)_L \times A_4 \times Z_3$ symmetry group.
[ { "created": "Mon, 22 Apr 2024 15:12:27 GMT", "version": "v1" } ]
2024-04-23
[ [ "Chakraborty", "Pralay", "" ], [ "Dev", "Tanmay", "" ], [ "Roy", "Subhankar", "" ] ]
We propose two new neutrino mass matrix textures deviating from $\mu-\tau$ symmetry and explore their phenomenological implications. Both textures predict $\theta_{23}$ and $\delta$ within sharp bounds while considering both normal and inverted ordering of neutrino masses. We try to realize these proposed textures within the framework of the seesaw mechanism, in association with the $SU(2)_L \times A_4 \times Z_3$ symmetry group.
1212.3045
Toshihiko Ota
Florian Bonnet, Martin Hirsch, Toshihiko Ota, Walter Winter
Systematic decomposition of the neutrinoless double beta decay operator
32 pages, 5 figures, 10 tables. Added errata for version 1
null
10.1007/JHEP03(2013)055
IFIC/12-079, MPP-2012-134, STUPP-12-212
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the systematic decomposition of the dimension nine neutrinoless double beta decay operator, focusing on mechanisms with potentially small contributions to neutrino mass, while being accessible at the LHC. We first provide a (d=9 tree-level) complete list of diagrams for neutrinoless double beta decay. From this list one can easily recover all previously discussed contributions to the neutrinoless double beta decay process, such as the celebrated mass mechanism or "exotics", such as contributions from left-right symmetric models, R-parity violating supersymmetry and leptoquarks. More interestingly, however, we identify a number of new possibilities which have not been discussed in the literature previously. Contact to earlier works based on a general Lorentz-invariant parametrisation of the neutrinoless double beta decay rate is made, which allows, in principle, to derive limits on all possible contributions. We furthermore discuss possible signals at the LHC for mediators leading to the short-range part of the amplitude with one specific example. The study of such contributions would gain particular importance if there were a tension between different measurements of neutrino mass such as coming from neutrinoless double beta decay and cosmology or single beta decay.
[ { "created": "Thu, 13 Dec 2012 03:20:08 GMT", "version": "v1" }, { "created": "Mon, 23 Jun 2014 06:31:02 GMT", "version": "v2" } ]
2015-06-12
[ [ "Bonnet", "Florian", "" ], [ "Hirsch", "Martin", "" ], [ "Ota", "Toshihiko", "" ], [ "Winter", "Walter", "" ] ]
We discuss the systematic decomposition of the dimension nine neutrinoless double beta decay operator, focusing on mechanisms with potentially small contributions to neutrino mass, while being accessible at the LHC. We first provide a (d=9 tree-level) complete list of diagrams for neutrinoless double beta decay. From this list one can easily recover all previously discussed contributions to the neutrinoless double beta decay process, such as the celebrated mass mechanism or "exotics", such as contributions from left-right symmetric models, R-parity violating supersymmetry and leptoquarks. More interestingly, however, we identify a number of new possibilities which have not been discussed in the literature previously. Contact to earlier works based on a general Lorentz-invariant parametrisation of the neutrinoless double beta decay rate is made, which allows, in principle, to derive limits on all possible contributions. We furthermore discuss possible signals at the LHC for mediators leading to the short-range part of the amplitude with one specific example. The study of such contributions would gain particular importance if there were a tension between different measurements of neutrino mass such as coming from neutrinoless double beta decay and cosmology or single beta decay.
hep-ph/0210110
Hael Collins
Hael Collins and R. Holman (Carnegie Mellon University)
The invisible axion in a Randall-Sundrum universe
8 pages, 1 figure, uses ReVTeX
Phys.Rev. D67 (2003) 105004
10.1103/PhysRevD.67.105004
CMU-HEP-02-10
hep-ph hep-th
null
We study the problem of integrating an invisible axion into the Randall-Sundrum scenario as an example of how to generate new energy scales between the extremes of the Planck mass and the electroweak scale. In this scenario, the axion corresponds to the phase of complex bulk scalar field. We show how to generate an intermediate energy scale by including a third brane in the scenario. We discuss the stabilization of this brane in detail to demonstrate that no additional fine-tunings arise.
[ { "created": "Mon, 7 Oct 2002 18:08:07 GMT", "version": "v1" }, { "created": "Tue, 18 Feb 2003 16:16:57 GMT", "version": "v2" } ]
2009-11-07
[ [ "Collins", "Hael", "", "Carnegie Mellon University" ], [ "Holman", "R.", "", "Carnegie Mellon University" ] ]
We study the problem of integrating an invisible axion into the Randall-Sundrum scenario as an example of how to generate new energy scales between the extremes of the Planck mass and the electroweak scale. In this scenario, the axion corresponds to the phase of complex bulk scalar field. We show how to generate an intermediate energy scale by including a third brane in the scenario. We discuss the stabilization of this brane in detail to demonstrate that no additional fine-tunings arise.
2402.19134
Sanjin Beni\'c
Sanjin Beni\'c, Adrian Dumitru, Abhiram Kaushik, Leszek Motyka, Tomasz Stebel
Photon-Odderon interference in exclusive $\chi_{c}$ charmonium production at the Electron-Ion Collider
minor updates, matches the published version
null
10.1103/PhysRevD.110.014025
ZTF-EP-24-02
hep-ph
http://creativecommons.org/licenses/by/4.0/
Exclusive $C=+1$ scalar, axial-vector, and tensor quarkonium production in high-energy electron-proton scattering requires a $C$-odd $t$-channel exchange of a photon or a three gluon ladder. We derive the expressions for the corresponding amplitudes. The relative phase of the photon vs. three gluon exchange amplitudes is determined by the sign of the light-front matrix element of the eikonal color current operator $d^{abc}J^{+a}J^{+b}J^{+c}$ at moderate $x$, and is not affected by small-$x$ QCD evolution. Model calculations predict constructive interference, which is particularly strong for momentum transfer $|t|\sim 1$~GeV$^2$ where the cross section for $\chi_{cJ}$ production exceeds that for pure photon exchange by up to a factor of 4. We find that exclusive $\chi_{cJ}$ electroproduction at the Electron-Ion Collider should occur with well measurable rates and measurements of these processes should allow to find an evidence of the perturbative Odderon exchange. We also compute the total electroproduction cross section as a function of energy and provide first estimates of the number of $\chi_{cJ}$ events per month at the Electron-Ion Collider design luminosity.
[ { "created": "Thu, 29 Feb 2024 13:09:42 GMT", "version": "v1" }, { "created": "Sat, 20 Jul 2024 12:06:19 GMT", "version": "v2" } ]
2024-07-23
[ [ "Benić", "Sanjin", "" ], [ "Dumitru", "Adrian", "" ], [ "Kaushik", "Abhiram", "" ], [ "Motyka", "Leszek", "" ], [ "Stebel", "Tomasz", "" ] ]
Exclusive $C=+1$ scalar, axial-vector, and tensor quarkonium production in high-energy electron-proton scattering requires a $C$-odd $t$-channel exchange of a photon or a three gluon ladder. We derive the expressions for the corresponding amplitudes. The relative phase of the photon vs. three gluon exchange amplitudes is determined by the sign of the light-front matrix element of the eikonal color current operator $d^{abc}J^{+a}J^{+b}J^{+c}$ at moderate $x$, and is not affected by small-$x$ QCD evolution. Model calculations predict constructive interference, which is particularly strong for momentum transfer $|t|\sim 1$~GeV$^2$ where the cross section for $\chi_{cJ}$ production exceeds that for pure photon exchange by up to a factor of 4. We find that exclusive $\chi_{cJ}$ electroproduction at the Electron-Ion Collider should occur with well measurable rates and measurements of these processes should allow to find an evidence of the perturbative Odderon exchange. We also compute the total electroproduction cross section as a function of energy and provide first estimates of the number of $\chi_{cJ}$ events per month at the Electron-Ion Collider design luminosity.
hep-ph/0407204
Barbara Mele
Barbara Mele
Beyond the Standard Model: Expectations at the LHC
16 pages, 13 figures, Plenary talk, Proceedings IFAE Conference, Torino, April 14-16, 2004; modified one sentence on TC theories
null
null
null
hep-ph
null
In this talk, I review the main motivations for expecting new physics at the TeV energy scale, that will be explorable at the CERN Large Hadron Collider.
[ { "created": "Mon, 19 Jul 2004 08:09:49 GMT", "version": "v1" }, { "created": "Mon, 26 Jul 2004 13:39:47 GMT", "version": "v2" } ]
2007-05-23
[ [ "Mele", "Barbara", "" ] ]
In this talk, I review the main motivations for expecting new physics at the TeV energy scale, that will be explorable at the CERN Large Hadron Collider.
hep-ph/0003145
Jon Urrestilla
Ana Achucarro, Jon Urrestilla
The (in)stability of global monopoles revisited
6 pages, 2 figures (uses RevTeX and epsf). Corrected an error in the original proof of stability, discussion extended to non-normalizable perturbations, one figure slightly modified, minor changes
Phys.Rev.Lett.85:3091-3094,2000
10.1103/PhysRevLett.85.3091
EHU-FT/0004
hep-ph hep-th
null
We analyse the stability of global O(3) monopoles in the infinite cut-off (or scalar mass) limit. We obtain the perturbation equations and prove that the spherically symmetric solution is classically stable (or neutrally stable) to axially symmetric square integrable or power-law decay perturbations. Moreover we show that, in spite of the existence of a conserved topological charge, the energy barrier between the monopole and the vacuum is finite even in the limit where the cut-off is taken to infinity. This feature is specific of global monopoles and independent of the details of the scalar potential.
[ { "created": "Wed, 15 Mar 2000 11:19:02 GMT", "version": "v1" }, { "created": "Tue, 25 Jul 2000 09:17:01 GMT", "version": "v2" } ]
2010-11-19
[ [ "Achucarro", "Ana", "" ], [ "Urrestilla", "Jon", "" ] ]
We analyse the stability of global O(3) monopoles in the infinite cut-off (or scalar mass) limit. We obtain the perturbation equations and prove that the spherically symmetric solution is classically stable (or neutrally stable) to axially symmetric square integrable or power-law decay perturbations. Moreover we show that, in spite of the existence of a conserved topological charge, the energy barrier between the monopole and the vacuum is finite even in the limit where the cut-off is taken to infinity. This feature is specific of global monopoles and independent of the details of the scalar potential.
2312.04303
Tarak Nath Maity
Ben Carew, Ashlee R. Caddell, Tarak Nath Maity, Ciaran A. J. O'Hare
The neutrino fog for dark matter-electron scattering experiments
14 pages, 6 figures, published version, added a new appendix
Phys. Rev. D 109, 083016 (2024)
null
null
hep-ph astro-ph.CO astro-ph.SR hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The search for sub-GeV dark matter via scattering on electrons has ramped up in the last few years. Like in the case of dark matter scattering on nuclei, electron-recoil-based searches also face an ultimate background in the form of neutrinos. The so-called ``neutrino fog'' refers to the range of open dark-matter parameter space where the background of neutrinos can potentially prevent a conclusive discovery claim of a dark matter signal from being made. In this study, we map the neutrino fog for a range of electron recoil experiments based on silicon, germanium, xenon and argon targets. In analogy to the nuclear recoil case, we also calculate the ''edge'' to the neutrino fog, which can be used as a visual guide to where neutrinos become an important background -- this boundary excludes some parts of the key theory milestones used to motivate these experiments.
[ { "created": "Thu, 7 Dec 2023 13:53:33 GMT", "version": "v1" }, { "created": "Mon, 22 Jan 2024 17:33:09 GMT", "version": "v2" }, { "created": "Thu, 18 Apr 2024 06:08:52 GMT", "version": "v3" } ]
2024-04-19
[ [ "Carew", "Ben", "" ], [ "Caddell", "Ashlee R.", "" ], [ "Maity", "Tarak Nath", "" ], [ "O'Hare", "Ciaran A. J.", "" ] ]
The search for sub-GeV dark matter via scattering on electrons has ramped up in the last few years. Like in the case of dark matter scattering on nuclei, electron-recoil-based searches also face an ultimate background in the form of neutrinos. The so-called ``neutrino fog'' refers to the range of open dark-matter parameter space where the background of neutrinos can potentially prevent a conclusive discovery claim of a dark matter signal from being made. In this study, we map the neutrino fog for a range of electron recoil experiments based on silicon, germanium, xenon and argon targets. In analogy to the nuclear recoil case, we also calculate the ''edge'' to the neutrino fog, which can be used as a visual guide to where neutrinos become an important background -- this boundary excludes some parts of the key theory milestones used to motivate these experiments.
1612.09043
Sarira Sahu
Sarira Sahu, Bing Zhang
On the non-detection of Glashow resonance in IceCube
single column, 11 pages
JHEAp 18 (2018) 1-4
10.1016/j.jheap.2018.01.003
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Electron anti-neutrinos at the Glashow resonance (GR, at $E_{\bar \nu_e} \sim 6.3$ PeV) have an enhanced probability to be detected. With three neutrinos detected by IceCube in the (1-2) PeV energy range at present, one would expect that about 1 to 4 GR $\bar\nu_e$ should have been detected. The high-energy $\sim 8.7$ PeV muon neutrino detected by IceCube may not be a GR event. If so, we expect to detect 50 to 70 GR $\bar\nu_e$, then one would have a "missing Glashow-resonance problem". This would suggest (1) that $p\gamma$ interaction rather than $pp$ interaction is the dominant channel to produce the observed IceCube high-energy neutrinos, (2) that multi-pion $p\gamma$ interactions are suppressed, and (3) that the magnetic field and photon energy density in the $p\gamma$ emission region is such that significant $\mu^+$ cooling occurs before decaying, yet $\pi^+$'s essentially do not cool before decaying.
[ { "created": "Thu, 29 Dec 2016 05:54:04 GMT", "version": "v1" }, { "created": "Fri, 27 Jul 2018 23:19:33 GMT", "version": "v2" } ]
2018-07-31
[ [ "Sahu", "Sarira", "" ], [ "Zhang", "Bing", "" ] ]
Electron anti-neutrinos at the Glashow resonance (GR, at $E_{\bar \nu_e} \sim 6.3$ PeV) have an enhanced probability to be detected. With three neutrinos detected by IceCube in the (1-2) PeV energy range at present, one would expect that about 1 to 4 GR $\bar\nu_e$ should have been detected. The high-energy $\sim 8.7$ PeV muon neutrino detected by IceCube may not be a GR event. If so, we expect to detect 50 to 70 GR $\bar\nu_e$, then one would have a "missing Glashow-resonance problem". This would suggest (1) that $p\gamma$ interaction rather than $pp$ interaction is the dominant channel to produce the observed IceCube high-energy neutrinos, (2) that multi-pion $p\gamma$ interactions are suppressed, and (3) that the magnetic field and photon energy density in the $p\gamma$ emission region is such that significant $\mu^+$ cooling occurs before decaying, yet $\pi^+$'s essentially do not cool before decaying.
hep-ph/9806389
Johann Rafelski
Johann Rafelski (Department of Physics, University of Arizona, Tucson, AZ) and H.-Thomas Elze (Instituto de Fisica, UFRJ, Rio de Janeiro, Brazil)
Electromagnetic Fields in the QCD Vacuum
16 pages, Invited lecture at: Workshop on Quantum Chromodynamics, Paris, France 1--6 June 1998, to appear in proceedings, World Scientific, H. Fried and B. Muller, edts
null
null
null
hep-ph
null
Quarks play an active role in shaping the QCD vacuum structure. Being dual carriers of both `color' and `electric' charges they also respond to externally applied electromagnetic fields. Thus, in principle, the vacuum of strong interactions influences higher order QED processes such as photon-photon scattering. We survey here the current status of the understanding of the vacuum structure of strong interactions, and take a fresh look at its electromagnetic properties.
[ { "created": "Tue, 16 Jun 1998 23:22:41 GMT", "version": "v1" }, { "created": "Thu, 22 Oct 1998 21:08:47 GMT", "version": "v2" } ]
2007-05-23
[ [ "Rafelski", "Johann", "", "Department of Physics, University of Arizona, Tucson,\n AZ" ], [ "Elze", "H. -Thomas", "", "Instituto de Fisica, UFRJ, Rio de Janeiro, Brazil" ] ]
Quarks play an active role in shaping the QCD vacuum structure. Being dual carriers of both `color' and `electric' charges they also respond to externally applied electromagnetic fields. Thus, in principle, the vacuum of strong interactions influences higher order QED processes such as photon-photon scattering. We survey here the current status of the understanding of the vacuum structure of strong interactions, and take a fresh look at its electromagnetic properties.