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hep-ph/0612367
Neil Russell
Neil Russell
The Standard-Model Extension and Tests of Relativity
Parallel-session invited talk at 11th Marcel Grossmann Meeting, Berlin, Germany, 23-29 July, 2006. 3pp
null
null
null
hep-ph
null
The Standard-Model Extension, or SME, is a general framework for the study of Lorentz violation in physics. A broad variety of experiments is able to access the SME coefficient space. This proceedings briefly summarizes theory and experiments aimed at testing Special Relativity by measuring these coefficients.
[ { "created": "Fri, 29 Dec 2006 09:16:51 GMT", "version": "v1" } ]
2007-05-23
[ [ "Russell", "Neil", "" ] ]
The Standard-Model Extension, or SME, is a general framework for the study of Lorentz violation in physics. A broad variety of experiments is able to access the SME coefficient space. This proceedings briefly summarizes theory and experiments aimed at testing Special Relativity by measuring these coefficients.
1111.5995
Umberto D'Alesio
Umberto D'Alesio (Dipartimento di Fisica, Universita' di Cagliari, and INFN, Sezione di Cagliari, Cittadella Universitaria, Monserrato (CA), Italy)
TMDs, universality and factorization
8 pages, 1 ps figure, uses cimento.cls. Talk delivered at the "Third International Workshop on Transverse Polarization Phenomena in Hard Scattering" (Transversity 2011), 29 Aug.-2 Sep. 2011, Veli Losinj (Croatia). Submitted to Nuovo Cimento C
null
10.1393/ncc/i2012-11171-3
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a short overview on transverse momentum dependent parton distribution and fragmentation functions, giving their partonic interpretation and ways to access them. We then discuss the issue of their universality and its connection to factorization in perturbative QCD.
[ { "created": "Fri, 25 Nov 2011 14:21:27 GMT", "version": "v1" } ]
2022-03-02
[ [ "D'Alesio", "Umberto", "", "Dipartimento di Fisica, Universita' di Cagliari, and\n INFN, Sezione di Cagliari, Cittadella Universitaria, Monserrato" ] ]
We present a short overview on transverse momentum dependent parton distribution and fragmentation functions, giving their partonic interpretation and ways to access them. We then discuss the issue of their universality and its connection to factorization in perturbative QCD.
1506.03520
Marco Farina
Marco Farina
Asymmetric Twin Dark Matter
15 pages, 2 figures, v2: final revision with minor corrections, matches the version published in JCAP
JCAP11(2015)017
10.1088/1475-7516/2015/11/017
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study a natural implementation of Asymmetric Dark Matter in Twin Higgs models. The mirroring of the Standard Model strong sector suggests that a twin baryon with mass around 5 GeV is a natural Dark Matter candidate once a twin baryon number asymmetry comparable to the SM asymmetry is generated. We explore twin baryon Dark Matter in two different scenarios, one with minimal content in the twin sector and one with a complete copy of the SM, including a light twin photon. The essential requirements for successful thermal history are presented, and in doing so we address some of the cosmological issues common to many Twin Higgs models. The required interactions we introduce predict signatures at direct detection experiments and at the LHC.
[ { "created": "Thu, 11 Jun 2015 00:48:07 GMT", "version": "v1" }, { "created": "Mon, 9 Nov 2015 21:45:15 GMT", "version": "v2" } ]
2015-11-11
[ [ "Farina", "Marco", "" ] ]
We study a natural implementation of Asymmetric Dark Matter in Twin Higgs models. The mirroring of the Standard Model strong sector suggests that a twin baryon with mass around 5 GeV is a natural Dark Matter candidate once a twin baryon number asymmetry comparable to the SM asymmetry is generated. We explore twin baryon Dark Matter in two different scenarios, one with minimal content in the twin sector and one with a complete copy of the SM, including a light twin photon. The essential requirements for successful thermal history are presented, and in doing so we address some of the cosmological issues common to many Twin Higgs models. The required interactions we introduce predict signatures at direct detection experiments and at the LHC.
2309.05244
Yuan Yin
Yuan Yin
The cosmological collider signal in the non-BD initial states
null
null
null
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the cosmological collider (CC) signal arising from the tree-level exchange of a scalar spectator particle with a non-Bunch Davies (BD) initial state. We decompose the inflaton correlators into seed integrals, which we compute analytically by solving the bootstrap equations. We show that the non-BD initial state eliminates the Hubble scale Boltzmann suppression $e^{-\pi m /H}$ that usually affects the CC signal. Consequently, in this scenario, the CC can probe an energy scale much higher than the inflationary Hubble scale $H$.
[ { "created": "Mon, 11 Sep 2023 05:37:16 GMT", "version": "v1" } ]
2023-09-12
[ [ "Yin", "Yuan", "" ] ]
We investigate the cosmological collider (CC) signal arising from the tree-level exchange of a scalar spectator particle with a non-Bunch Davies (BD) initial state. We decompose the inflaton correlators into seed integrals, which we compute analytically by solving the bootstrap equations. We show that the non-BD initial state eliminates the Hubble scale Boltzmann suppression $e^{-\pi m /H}$ that usually affects the CC signal. Consequently, in this scenario, the CC can probe an energy scale much higher than the inflationary Hubble scale $H$.
hep-ph/0102035
Matthew Lilley
Matthew Lilley and Antonio Ferrera
Defect Formation Rates in Cosmological First-Order Phase Transitions
9 pages, 5 figures. Replaced with version to appear in Physical Review D
Phys.Rev. D64 (2001) 023520
10.1103/PhysRevD.64.023520
HD-THEP-01-05, DAMTP-2001-11
hep-ph
null
In cosmological first-order phase transitions, the progress of true-vacuum bubbles is expected to be significantly retarded by the interaction between the bubble wall and the hot plasma. It has been claimed that this leads to a significant reduction in the number of topological defects formed per bubble, as a result of phase equilibration between bubbles. This claim has been verified for spontaneously-broken global symmetries. We perform a series of simulations of complete phase transitions in the 2+1-dimensional U(1)-Abelian Higgs model, for a range of bubble wall velocities, in order to obtain a quantitative measure of the effect of bubble wall speed on the number density of topological defects. We find that the number of defects formed is i) significantly lower in the local than the global case and ii) decreases exponentially as a function of wall velocity. Slow-moving bubbles also lead, however, to the nucleation of more bubbles before the phase transition is complete. Our simulations show that this is in fact the dominant effect, and so we predict {\em more} defects per unit volume as a result of the sub-luminal bubble wall terminal velocity.
[ { "created": "Sun, 4 Feb 2001 17:29:55 GMT", "version": "v1" }, { "created": "Fri, 27 Apr 2001 18:10:15 GMT", "version": "v2" } ]
2009-11-07
[ [ "Lilley", "Matthew", "" ], [ "Ferrera", "Antonio", "" ] ]
In cosmological first-order phase transitions, the progress of true-vacuum bubbles is expected to be significantly retarded by the interaction between the bubble wall and the hot plasma. It has been claimed that this leads to a significant reduction in the number of topological defects formed per bubble, as a result of phase equilibration between bubbles. This claim has been verified for spontaneously-broken global symmetries. We perform a series of simulations of complete phase transitions in the 2+1-dimensional U(1)-Abelian Higgs model, for a range of bubble wall velocities, in order to obtain a quantitative measure of the effect of bubble wall speed on the number density of topological defects. We find that the number of defects formed is i) significantly lower in the local than the global case and ii) decreases exponentially as a function of wall velocity. Slow-moving bubbles also lead, however, to the nucleation of more bubbles before the phase transition is complete. Our simulations show that this is in fact the dominant effect, and so we predict {\em more} defects per unit volume as a result of the sub-luminal bubble wall terminal velocity.
1504.06624
Felix Kling
Felix Kling, Adarsh Pyarelal, Shufang Su
Light Charged Higgs Bosons to AW/HW via Top Decay
21 pages. arXiv admin note: text overlap with arXiv:1408.4119
null
10.1007/JHEP11(2015)051
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
While current ATLAS and CMS measurements exclude a light charged Higgs ($m_{H^\pm}<160$ GeV) for most of the parameter region in the context of the MSSM scenarios, these bounds are significantly weakened in the Type II 2HDM once the exotic decay channel into a lighter neutral Higgs, $H^\pm \to AW/HW$, is open. In this study, we examine the possibility of a light charged Higgs produced in top decay via single top or top pair production, with the subsequent decay $H^\pm \rightarrow AW/HW$, which can reach a sizable branching fraction at low $\tan\beta$ once it is kinematically permitted. With a detailed collider analysis, we obtain exclusion and discovery bounds for the 14 TeV LHC assuming the existence of a 70 GeV neutral scalar. Assuming ${\rm BR}(H^\pm \rightarrow AW/HW)=100\%$ and ${\rm BR}(A/H \rightarrow \tau\tau)=8.6\%$, the 95% exclusion limits on ${\rm BR}(t \rightarrow H^+ b)$ are about 0.2% and 0.03% for single top and top pair production respectively, with an integrated luminosity of 300 ${\rm fb}^{-1}$. The discovery reaches are about 3 times higher. In the context of the Type II 2HDM, discovery is possible at both large $\tan\beta > 17$ for 155 GeV $< m_{H^\pm} <$ 165 GeV, and small $\tan\beta < 6$ over the entire mass range. Exclusion is possible in the entire $\tan\beta$ versus $m_{H^\pm}$ plane except for charged Higgs masses close to the top threshold. The exotic decay channel $H^\pm \to AW/HW$ is therefore complementary to the conventional $H^\pm \rightarrow \tau\nu$ channel.
[ { "created": "Fri, 24 Apr 2015 20:00:37 GMT", "version": "v1" }, { "created": "Wed, 28 Sep 2016 06:21:41 GMT", "version": "v2" } ]
2016-09-29
[ [ "Kling", "Felix", "" ], [ "Pyarelal", "Adarsh", "" ], [ "Su", "Shufang", "" ] ]
While current ATLAS and CMS measurements exclude a light charged Higgs ($m_{H^\pm}<160$ GeV) for most of the parameter region in the context of the MSSM scenarios, these bounds are significantly weakened in the Type II 2HDM once the exotic decay channel into a lighter neutral Higgs, $H^\pm \to AW/HW$, is open. In this study, we examine the possibility of a light charged Higgs produced in top decay via single top or top pair production, with the subsequent decay $H^\pm \rightarrow AW/HW$, which can reach a sizable branching fraction at low $\tan\beta$ once it is kinematically permitted. With a detailed collider analysis, we obtain exclusion and discovery bounds for the 14 TeV LHC assuming the existence of a 70 GeV neutral scalar. Assuming ${\rm BR}(H^\pm \rightarrow AW/HW)=100\%$ and ${\rm BR}(A/H \rightarrow \tau\tau)=8.6\%$, the 95% exclusion limits on ${\rm BR}(t \rightarrow H^+ b)$ are about 0.2% and 0.03% for single top and top pair production respectively, with an integrated luminosity of 300 ${\rm fb}^{-1}$. The discovery reaches are about 3 times higher. In the context of the Type II 2HDM, discovery is possible at both large $\tan\beta > 17$ for 155 GeV $< m_{H^\pm} <$ 165 GeV, and small $\tan\beta < 6$ over the entire mass range. Exclusion is possible in the entire $\tan\beta$ versus $m_{H^\pm}$ plane except for charged Higgs masses close to the top threshold. The exotic decay channel $H^\pm \to AW/HW$ is therefore complementary to the conventional $H^\pm \rightarrow \tau\nu$ channel.
hep-ph/0007349
Jose Antonio Oller
J.A. Oller
Scalar Mesons and Chiral Symmetry
8 pages,2 figures. Invited talk at the $\sigma$-meson workshop, Kyoto, June 2000
null
null
null
hep-ph hep-ex nucl-th
null
It is the purpose of the present manuscript to emphasize those aspects that make the scalar sector with vacuum quantum numbers rather unique. Chiral symmetry is the basic tool for our study together with a resummation of Chiral Perturbation Theory (CHPT) that stresses the role of unitarity but also allows one to include explicit resonance fields and to match with the CHPT expansion at low energies.
[ { "created": "Sun, 30 Jul 2000 09:04:22 GMT", "version": "v1" } ]
2007-05-23
[ [ "Oller", "J. A.", "" ] ]
It is the purpose of the present manuscript to emphasize those aspects that make the scalar sector with vacuum quantum numbers rather unique. Chiral symmetry is the basic tool for our study together with a resummation of Chiral Perturbation Theory (CHPT) that stresses the role of unitarity but also allows one to include explicit resonance fields and to match with the CHPT expansion at low energies.
1603.03052
Lisa Zeune
Frank J. Tackmann, Wouter J. Waalewijn, Lisa Zeune
Impact of Jet Veto Resummation on Slepton Searches
29 pages, 11 figures
null
10.1007/JHEP07(2016)119
NIKHEF 2016-010, DESY 16-044
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Several searches for new physics at the LHC require a fixed number of signal jets, vetoing events with additional jets from QCD radiation. As the probed scale of new physics gets much larger than the jet-veto scale, such jet vetoes strongly impact the QCD perturbative series, causing nontrivial theoretical uncertainties. We consider slepton pair production with 0 signal jets, for which we perform the resummation of jet-veto logarithms and study its impact. Currently, the experimental exclusion limits take the jet-veto cut into account by extrapolating to the inclusive cross section using parton shower Monte Carlos. Our results indicate that the associated theoretical uncertainties can be large, and when taken into account have a sizeable impact already on present exclusion limits. This is improved by performing the resummation to higher order, which allows us to obtain accurate predictions even for high slepton masses. For the interpretation of the experimental results to benefit from improved theory predictions, it would be useful for the experimental analyses to also provide limits on the unfolded visible 0-jet cross section.
[ { "created": "Wed, 9 Mar 2016 21:00:26 GMT", "version": "v1" } ]
2016-08-24
[ [ "Tackmann", "Frank J.", "" ], [ "Waalewijn", "Wouter J.", "" ], [ "Zeune", "Lisa", "" ] ]
Several searches for new physics at the LHC require a fixed number of signal jets, vetoing events with additional jets from QCD radiation. As the probed scale of new physics gets much larger than the jet-veto scale, such jet vetoes strongly impact the QCD perturbative series, causing nontrivial theoretical uncertainties. We consider slepton pair production with 0 signal jets, for which we perform the resummation of jet-veto logarithms and study its impact. Currently, the experimental exclusion limits take the jet-veto cut into account by extrapolating to the inclusive cross section using parton shower Monte Carlos. Our results indicate that the associated theoretical uncertainties can be large, and when taken into account have a sizeable impact already on present exclusion limits. This is improved by performing the resummation to higher order, which allows us to obtain accurate predictions even for high slepton masses. For the interpretation of the experimental results to benefit from improved theory predictions, it would be useful for the experimental analyses to also provide limits on the unfolded visible 0-jet cross section.
hep-ph/9710389
Martti Raidal
M. Raidal and A. Santamaria
\mu-e conversion in nuclei versus \mu-->e \gamma : an effective field theory point of view
A few references added, to appear in PLB
Phys.Lett. B421 (1998) 250-258
10.1016/S0370-2693(98)00020-3
FTUV/97-56
hep-ph
null
Using an effective lagrangian description we analyze possible new physics contributions to the most relevant muon number violating processes: $\mu \to e \gamma$ and $\mu$--$e$ conversion in nuclei. We identify a general class of models in which those processes are generated at one loop level and in which $\mu$--$e$ conversion is enhanced with respect to $\mu \to e \gamma$ by a large $\ln(m^2_\mu/\Lambda^2),$ where $\Lambda$ is the scale responsible for the new physics. For this wide class of models bounds on $\mu$--$e$ conversion constrain the scale of new physics more stringently than $\mu \to e \gamma$ already at present and, with the expected improvements in $\mu$--$e$ conversion experiments, will push it upwards by about one order of magnitude more. To illustrate this general result we give an explicit model containing a doubly charged scalar and derive new bounds on its couplings to the leptons.
[ { "created": "Fri, 17 Oct 1997 13:18:45 GMT", "version": "v1" }, { "created": "Fri, 9 Jan 1998 16:04:35 GMT", "version": "v2" } ]
2009-10-30
[ [ "Raidal", "M.", "" ], [ "Santamaria", "A.", "" ] ]
Using an effective lagrangian description we analyze possible new physics contributions to the most relevant muon number violating processes: $\mu \to e \gamma$ and $\mu$--$e$ conversion in nuclei. We identify a general class of models in which those processes are generated at one loop level and in which $\mu$--$e$ conversion is enhanced with respect to $\mu \to e \gamma$ by a large $\ln(m^2_\mu/\Lambda^2),$ where $\Lambda$ is the scale responsible for the new physics. For this wide class of models bounds on $\mu$--$e$ conversion constrain the scale of new physics more stringently than $\mu \to e \gamma$ already at present and, with the expected improvements in $\mu$--$e$ conversion experiments, will push it upwards by about one order of magnitude more. To illustrate this general result we give an explicit model containing a doubly charged scalar and derive new bounds on its couplings to the leptons.
2006.09687
Madan Singh
Madan Singh
Implications of CP invariants for flavoured hybrid neutrino mass matrix
13 pages, This version is accepted for publication in Prog. of theoretical and Experimental physics(PTEP)
Prog Theor. Exp. Phys., 2020, 093B04
10.1093/ptep/ptaa123
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In the present paper, I have re-examined the weak basis invariants at low energies, proposed by C. Jarlskog and Branco et. al, respectively, in their earlier analyses, after confronting them with the assumptions of two zeros and an equality between arbitrary non-zero elements in the Majorana neutrino mass matrix in the flavoured basis. This particular conjecture is found to be experimentally feasible as shown by S. Dev and D. Raj in their recent work. The present analysis attempts to find the necessary and sufficient condition for CP invariance for each experimentally viable ans\"atz, pertaining to the model along with some important implications.
[ { "created": "Wed, 17 Jun 2020 07:09:22 GMT", "version": "v1" }, { "created": "Fri, 7 Aug 2020 14:57:29 GMT", "version": "v2" } ]
2020-10-14
[ [ "Singh", "Madan", "" ] ]
In the present paper, I have re-examined the weak basis invariants at low energies, proposed by C. Jarlskog and Branco et. al, respectively, in their earlier analyses, after confronting them with the assumptions of two zeros and an equality between arbitrary non-zero elements in the Majorana neutrino mass matrix in the flavoured basis. This particular conjecture is found to be experimentally feasible as shown by S. Dev and D. Raj in their recent work. The present analysis attempts to find the necessary and sufficient condition for CP invariance for each experimentally viable ans\"atz, pertaining to the model along with some important implications.
1309.3549
John Ellis
John Ellis
Summary of the Nobel Symposium on LHC Results
18 pages, 6 figures, Nobel Symposium on LHC Results
null
10.1088/0031-8949/2013/T158/014020
KCL-PH-TH/2013-30, LCTS/2013-21, CERN-PH-TH/2013-218
hep-ph hep-ex hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This is a personal summary of points made during, and arising from the symposium, drawing largely from the talks presented there. The Standard Model is doing fine, including QCD, the electroweak sector and flavour physics. The good news is that a Standard-Model-like Higgs boson has appeared with the predicted mass, but the bad news is that the LHC has provided no hint of other new physics. On the other hand, physics beyond the Standard Model is needed to explain neutrino masses and mixing, and we look forward to experiments revealing their mass hierarchy and CP violation. Cosmology and astrophysics also require new physics to explain the origin of matter, dark matter, dark energy and the CMB fluctuations. I still think that supersymmetry is the best-motivated extension of the Standard Model, and look forward to the next phases of LHC operation at higher energy and luminosity. In the mean time, ideas abound for a new accelerator to study the Higgs boson in detail and/or whatever else the LHC may reveal in its next run.
[ { "created": "Fri, 13 Sep 2013 19:40:01 GMT", "version": "v1" } ]
2015-06-17
[ [ "Ellis", "John", "" ] ]
This is a personal summary of points made during, and arising from the symposium, drawing largely from the talks presented there. The Standard Model is doing fine, including QCD, the electroweak sector and flavour physics. The good news is that a Standard-Model-like Higgs boson has appeared with the predicted mass, but the bad news is that the LHC has provided no hint of other new physics. On the other hand, physics beyond the Standard Model is needed to explain neutrino masses and mixing, and we look forward to experiments revealing their mass hierarchy and CP violation. Cosmology and astrophysics also require new physics to explain the origin of matter, dark matter, dark energy and the CMB fluctuations. I still think that supersymmetry is the best-motivated extension of the Standard Model, and look forward to the next phases of LHC operation at higher energy and luminosity. In the mean time, ideas abound for a new accelerator to study the Higgs boson in detail and/or whatever else the LHC may reveal in its next run.
1112.2696
Koji Ishiwata
Koji Ishiwata
Dark Matter in Classically Scale-Invariant Two Singlets Standard Model
6 pages, 1 figure, published version
null
10.1016/j.physletb.2012.02.048
CALT 68-2860
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a model where two new scalars are introduced in the standard model, assuming classical scale invariance. In this model the scale invariance is broken by quantum corrections and one of the new scalars acquires non-zero vacuum expectation value (VEV), which induces the electroweak symmetry breaking in the standard model, and the other scalar becomes dark matter. It is shown that TeV scale dark matter is realized, independent of the value of the other scalar's VEV. The impact of the new scalars on the Higgs potential is also discussed. The Higgs potential is stabilized when the Higgs mass is over ~120 GeV.
[ { "created": "Mon, 12 Dec 2011 20:59:46 GMT", "version": "v1" }, { "created": "Mon, 5 Mar 2012 21:19:59 GMT", "version": "v2" } ]
2015-06-03
[ [ "Ishiwata", "Koji", "" ] ]
We consider a model where two new scalars are introduced in the standard model, assuming classical scale invariance. In this model the scale invariance is broken by quantum corrections and one of the new scalars acquires non-zero vacuum expectation value (VEV), which induces the electroweak symmetry breaking in the standard model, and the other scalar becomes dark matter. It is shown that TeV scale dark matter is realized, independent of the value of the other scalar's VEV. The impact of the new scalars on the Higgs potential is also discussed. The Higgs potential is stabilized when the Higgs mass is over ~120 GeV.
hep-ph/0004057
Herbert Weigel
H. Weigel and L. Gamberg
Hadron Structure Functions within a Chiral Quark Model
Talk prepared for the QNP 2000 conference in Adelaide Feb. 2000 and to appear in the proceedings. Presentation prevented by United Airlines. Four pages, uses esppre.sty which is included
Nucl.Phys. A680 (2000) 48-51
10.1016/S0375-9474(00)00386-9
MIT-CTP-2966,OUHEP-00-02
hep-ph
null
We outline a consistent regularization procedure to compute hadron structure functions within bosonized chiral quark models. We impose the Pauli--Villars scheme, which reproduces the chiral anomaly, to regularize the bosonized action. We derive the Compton amplitude from this action and utilize the Bjorken limit to extract structure functions that are consistent with the scaling laws and sum rules of deep inelastic scattering.
[ { "created": "Thu, 6 Apr 2000 15:50:27 GMT", "version": "v1" } ]
2009-10-31
[ [ "Weigel", "H.", "" ], [ "Gamberg", "L.", "" ] ]
We outline a consistent regularization procedure to compute hadron structure functions within bosonized chiral quark models. We impose the Pauli--Villars scheme, which reproduces the chiral anomaly, to regularize the bosonized action. We derive the Compton amplitude from this action and utilize the Bjorken limit to extract structure functions that are consistent with the scaling laws and sum rules of deep inelastic scattering.
0812.2745
Christian Fischer
Christian S. Fischer, Axel Maas and Jan M. Pawlowski
Aspects of confinement from QCD correlation functions
5 pages, 2 figures; invited talk presented by CF at the conference "Quark Confinement and the Hadron Spectrum VIII", Mainz, Germany, 1st-6th of September 2008
PoS Confinement8:043,2008
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the properties of ghost and gluon propagators in Landau gauge Yang-Mills theory and their relation to the confinement problem. In general two types of infrared behavior of these functions are allowed from their functional equations: scaling and decoupling. Both solutions show positivity violations in the gluon propagator and lead to a confining Polyakov loop potential. However, only the scaling solution agrees with the Kugo-Ojima confinement scenario and the related formulation of a physical Hilbert space of Yang-Mills theory. Our numerical results for the gluon dressing function agree almost pointwise with the lattice results at all physical momenta.
[ { "created": "Mon, 15 Dec 2008 08:43:26 GMT", "version": "v1" } ]
2009-06-25
[ [ "Fischer", "Christian S.", "" ], [ "Maas", "Axel", "" ], [ "Pawlowski", "Jan M.", "" ] ]
We discuss the properties of ghost and gluon propagators in Landau gauge Yang-Mills theory and their relation to the confinement problem. In general two types of infrared behavior of these functions are allowed from their functional equations: scaling and decoupling. Both solutions show positivity violations in the gluon propagator and lead to a confining Polyakov loop potential. However, only the scaling solution agrees with the Kugo-Ojima confinement scenario and the related formulation of a physical Hilbert space of Yang-Mills theory. Our numerical results for the gluon dressing function agree almost pointwise with the lattice results at all physical momenta.
hep-ph/9803231
Igor Shovkovy
E. P. Esposito, I. A. Shovkovy and L. C. R. Wijewardhana
The next to leading order effective potential in the 2+1 dimensional Nambu-Jona-Lasinio model at finite temperature
12 pages, 4 figures, REVTeX
Phys. Rev. D 58, 065003 (1998)
10.1103/PhysRevD.58.065003
null
hep-ph hep-th
null
The finite temperature effective potential in the 2+1 dimensional Nambu-Jona-Lasinio model is constructed up to the next to leading order in the large $N$ expansion, where $N$ is the number of flavors in the model. The distinctive feature of the analysis is an inclusion of an additional scalar field, which allows us to circumvent the well known, and otherwise unavoidable problem with the imaginary contribution to the effective potential. In accordance with the Mermin-Wagner-Coleman theorem, applied to the dimensionally reduced subsystem of the zero Matsubara modes of the composite boson fields, the finite temperature effective potential reveals a global minimum at the zero of the composite order parameter. This allows us to conclude that the continuous global symmetry of the NJL model is not broken for any arbitrarily small, finite temperature.
[ { "created": "Tue, 3 Mar 1998 18:04:31 GMT", "version": "v1" }, { "created": "Thu, 9 Apr 1998 20:31:51 GMT", "version": "v2" }, { "created": "Fri, 10 Apr 1998 14:32:42 GMT", "version": "v3" } ]
2016-08-25
[ [ "Esposito", "E. P.", "" ], [ "Shovkovy", "I. A.", "" ], [ "Wijewardhana", "L. C. R.", "" ] ]
The finite temperature effective potential in the 2+1 dimensional Nambu-Jona-Lasinio model is constructed up to the next to leading order in the large $N$ expansion, where $N$ is the number of flavors in the model. The distinctive feature of the analysis is an inclusion of an additional scalar field, which allows us to circumvent the well known, and otherwise unavoidable problem with the imaginary contribution to the effective potential. In accordance with the Mermin-Wagner-Coleman theorem, applied to the dimensionally reduced subsystem of the zero Matsubara modes of the composite boson fields, the finite temperature effective potential reveals a global minimum at the zero of the composite order parameter. This allows us to conclude that the continuous global symmetry of the NJL model is not broken for any arbitrarily small, finite temperature.
1310.4007
Jarah Evslin
Jarah Evslin
Confidence in the neutrino mass hierarchy
4 pages, 6 jpg figures, NUFACT 2013 proceedings, v2 Terminology standardized
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The number of sigma of confidence in a determination of the neutrino mass hierarchy may be obtained from the statistic Delta chi squared. However, as the hierarchy is a discrete variable, this number is not given by the usual square root formula. We review a simple Bayesian formula for the sensitivity to the hierarchy that can be obtained from the median experiment as a function of Delta chi squared. We compare this analytical formula to 6 years of simulated data from JUNO together with a 4% (1%) determination of the effective atmospheric mass splitting from the disappearance channel at MINOS (NOvA). We find a Delta chi squared of 11 (20) yielding 2.6 sigma (3.9 sigma). However when the unknown nonlinear energy response of the detector is included in our analysis this significance degrades considerably. This degradation can be eliminated by dividing the single detector into a near and far detector of the same total target mass. A further advantage of a second detector is that, even while the reactor neutrino experiment runs, the decay at rest of a single, high intensity, continuously running pion source close to one of the detectors, such as that described by the DAEdALUS project, may determine the leptonic CP-violating phase delta.
[ { "created": "Tue, 15 Oct 2013 11:12:58 GMT", "version": "v1" }, { "created": "Thu, 14 Nov 2013 07:59:10 GMT", "version": "v2" } ]
2013-11-15
[ [ "Evslin", "Jarah", "" ] ]
The number of sigma of confidence in a determination of the neutrino mass hierarchy may be obtained from the statistic Delta chi squared. However, as the hierarchy is a discrete variable, this number is not given by the usual square root formula. We review a simple Bayesian formula for the sensitivity to the hierarchy that can be obtained from the median experiment as a function of Delta chi squared. We compare this analytical formula to 6 years of simulated data from JUNO together with a 4% (1%) determination of the effective atmospheric mass splitting from the disappearance channel at MINOS (NOvA). We find a Delta chi squared of 11 (20) yielding 2.6 sigma (3.9 sigma). However when the unknown nonlinear energy response of the detector is included in our analysis this significance degrades considerably. This degradation can be eliminated by dividing the single detector into a near and far detector of the same total target mass. A further advantage of a second detector is that, even while the reactor neutrino experiment runs, the decay at rest of a single, high intensity, continuously running pion source close to one of the detectors, such as that described by the DAEdALUS project, may determine the leptonic CP-violating phase delta.
hep-ph/0312153
Christoph Adam
C. Adam and F.R. Klinkhamer
Comment on "Vacuum Photon Splitting in Lorentz-Violating Quantum Electrodynamics"
3 pages revtex4
null
null
KA-TP-06-200
hep-ph
null
It has been argued in hep-ph/0212382 that there may be observable effects from photon triple splitting in an extended version of quantum electrodynamics with Lorentz violation in the fermion sector. The argument is based on an analogy with photon splitting via collinear parametric down-conversion in optically active crystals. In this Comment, we point out that the analogy is misleading and that, at the order considered, the probability of on-shell photon triple splitting is strictly zero.
[ { "created": "Thu, 11 Dec 2003 15:18:45 GMT", "version": "v1" } ]
2007-05-23
[ [ "Adam", "C.", "" ], [ "Klinkhamer", "F. R.", "" ] ]
It has been argued in hep-ph/0212382 that there may be observable effects from photon triple splitting in an extended version of quantum electrodynamics with Lorentz violation in the fermion sector. The argument is based on an analogy with photon splitting via collinear parametric down-conversion in optically active crystals. In this Comment, we point out that the analogy is misleading and that, at the order considered, the probability of on-shell photon triple splitting is strictly zero.
2306.14982
Lucas Johns
Lucas Johns
Thermodynamics of oscillating neutrinos
7+2 pages, 1 figure
null
null
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The title theory is formulated. It entails a quantum-coherent variant of the Fermi-Dirac distribution and casts new light on neutrino oscillations. It might enable the incorporation of neutrino mixing into the modeling of core-collapse supernovae and neutron-star mergers.
[ { "created": "Mon, 26 Jun 2023 18:07:56 GMT", "version": "v1" } ]
2023-06-28
[ [ "Johns", "Lucas", "" ] ]
The title theory is formulated. It entails a quantum-coherent variant of the Fermi-Dirac distribution and casts new light on neutrino oscillations. It might enable the incorporation of neutrino mixing into the modeling of core-collapse supernovae and neutron-star mergers.
hep-ph/0702266
Yu. A. Simonov
Yu.A.Simonov
Nonperturbative equation of state of quark-gluon plasma
40 pages, no figures; some typos corrected
Annals Phys. 323, 783 (2008), Annals Phys. 323, 1230 (2008)
10.1016/j.aop.2007.07.005, 10.1016/j.aop.2007.05.007
null
hep-ph
null
The paper is devoted to the systematic derivation of nonperturbative thermodynamics of quark-gluon plasma, on the basis of the background perturbation theory. Vacuum background fields enter only in the form of field correlators, which are known from lattice and analytic calculations. In the lowest order in $\alpha_s$ the purely nonperturbative $sQGP$ thermodynamics is expressed through single quark and gluon lines (single line approximation) which are interacting nonperturbatively with vacuum fields and with other lines. Nonperturbative EOS is obtained in terms (of the absolute value) of fundamental (adjoint) Polyakov loop $L_{fund(adj)}$ and spatial string tension $\sigma_s(T)$. In the lowest approximation the pressure for quarks (gluons) has a simple factorized form $P_{q(g)}= P_{SB} L_{fund(adj)} ,$ where $ L_i$ describe the action of vacuum colorelectric fields on particle trajectory.
[ { "created": "Mon, 26 Feb 2007 16:45:46 GMT", "version": "v1" }, { "created": "Mon, 2 Apr 2007 15:07:37 GMT", "version": "v2" } ]
2014-01-29
[ [ "Simonov", "Yu. A.", "" ] ]
The paper is devoted to the systematic derivation of nonperturbative thermodynamics of quark-gluon plasma, on the basis of the background perturbation theory. Vacuum background fields enter only in the form of field correlators, which are known from lattice and analytic calculations. In the lowest order in $\alpha_s$ the purely nonperturbative $sQGP$ thermodynamics is expressed through single quark and gluon lines (single line approximation) which are interacting nonperturbatively with vacuum fields and with other lines. Nonperturbative EOS is obtained in terms (of the absolute value) of fundamental (adjoint) Polyakov loop $L_{fund(adj)}$ and spatial string tension $\sigma_s(T)$. In the lowest approximation the pressure for quarks (gluons) has a simple factorized form $P_{q(g)}= P_{SB} L_{fund(adj)} ,$ where $ L_i$ describe the action of vacuum colorelectric fields on particle trajectory.
1303.4974
Peter Zeiler Skands
L. Hartgring, E. Laenen, P. Skands
Antenna Showers with One-Loop Matrix Elements
null
null
10.1007/JHEP10(2013)127
CERN-PH-TH/2013-038, NIKHEF-2013-004, ITF-UU-13-02
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the probability for a colour-singlet qqbar pair to emit a gluon, in strongly and smoothly ordered antenna showers. We expand to second order in alphaS and compare to the second-order QCD matrix elements for Z -> 3 jets, neglecting terms suppressed by 1/NC^2. We give a prescription that corrects the shower to the matrix-element result at this order for both soft and hard emissions, thereby explicitly reducing its dependence on evolution- and renormalization-scale choices. We confirm that the choice of pT for both of these scales absorbs all logarithms through order alphaS^2, and contrast this with various alternatives. We include these corrections in the VINCIA shower generator and study the impact on LEP event-shape and fragmentation observables. An uncertainty estimate is provided for each event, in the form of a vector of alternative weights.
[ { "created": "Wed, 20 Mar 2013 16:05:16 GMT", "version": "v1" }, { "created": "Fri, 6 Sep 2013 06:06:25 GMT", "version": "v2" }, { "created": "Mon, 3 Oct 2016 04:08:51 GMT", "version": "v3" } ]
2016-10-04
[ [ "Hartgring", "L.", "" ], [ "Laenen", "E.", "" ], [ "Skands", "P.", "" ] ]
We consider the probability for a colour-singlet qqbar pair to emit a gluon, in strongly and smoothly ordered antenna showers. We expand to second order in alphaS and compare to the second-order QCD matrix elements for Z -> 3 jets, neglecting terms suppressed by 1/NC^2. We give a prescription that corrects the shower to the matrix-element result at this order for both soft and hard emissions, thereby explicitly reducing its dependence on evolution- and renormalization-scale choices. We confirm that the choice of pT for both of these scales absorbs all logarithms through order alphaS^2, and contrast this with various alternatives. We include these corrections in the VINCIA shower generator and study the impact on LEP event-shape and fragmentation observables. An uncertainty estimate is provided for each event, in the form of a vector of alternative weights.
1609.07122
Michele Redi
Alessandro Agugliaro, Oleg Antipin, Diego Becciolini, Stefania De Curtis, Michele Redi
UV complete composite Higgs models
30 pages; v2 minor changes
Phys. Rev. D 95, 035019 (2017)
10.1103/PhysRevD.95.035019
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study confining gauge theories with fermions vectorial under the SM that produce a Higgs doublet as a Nambu-Goldstone boson. The vacuum misalignment required to break the electro-weak symmetry is induced by an elementary Higgs doublet with Yukawa couplings to the new fermions. The physical Higgs is a linear combination of elementary and composite Higgses while the SM fermions remain elementary. The full theory is renormalizable and the SM Yukawa couplings are generated from the ones of the elementary Higgs allowing to eliminate all flavour problems but with interesting effects for Electric Dipole Moments of SM particles. We also discuss how ideas on the relaxation of the electro-weak scale could be realised within this framework.
[ { "created": "Thu, 22 Sep 2016 19:34:48 GMT", "version": "v1" }, { "created": "Sun, 25 Dec 2016 16:47:41 GMT", "version": "v2" } ]
2017-02-22
[ [ "Agugliaro", "Alessandro", "" ], [ "Antipin", "Oleg", "" ], [ "Becciolini", "Diego", "" ], [ "De Curtis", "Stefania", "" ], [ "Redi", "Michele", "" ] ]
We study confining gauge theories with fermions vectorial under the SM that produce a Higgs doublet as a Nambu-Goldstone boson. The vacuum misalignment required to break the electro-weak symmetry is induced by an elementary Higgs doublet with Yukawa couplings to the new fermions. The physical Higgs is a linear combination of elementary and composite Higgses while the SM fermions remain elementary. The full theory is renormalizable and the SM Yukawa couplings are generated from the ones of the elementary Higgs allowing to eliminate all flavour problems but with interesting effects for Electric Dipole Moments of SM particles. We also discuss how ideas on the relaxation of the electro-weak scale could be realised within this framework.
1012.5502
Takashi Hiramatsu
Takashi Hiramatsu, Masahiro Kawasaki, Toyokazu Sekiguchi, Masahide Yamaguchi, Jun'ichi Yokoyama
Improved estimation of radiated axions from cosmological axionic strings
24 pages, 7 figures
Phys.Rev.D83:123531, 2011
10.1103/PhysRevD.83.123531
ICRR-Report-579-2010-12, IPMU10-0229, RESCEU-29/10, YITP-10-111
hep-ph astro-ph.CO gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Cosmological evolution of axionic string network is analyzed in terms of field-theoretic simulations in a box of 512^3 grids, which are the largest ever, using a new and more efficient identification scheme of global strings. The scaling parameter is found to be \xi=0.87 +- 0.14 in agreement with previous results. The energy spectrum is calculated precisely using a pseudo power spectrum estimator which significantly reduces the error in the mean reciprocal comoving momentum. The resultant constraint on the axion decay constant leads to f_a <= 3*10^11 GeV. We also discuss implications for the early Universe.
[ { "created": "Sun, 26 Dec 2010 08:49:46 GMT", "version": "v1" }, { "created": "Wed, 29 Jun 2011 03:56:31 GMT", "version": "v2" } ]
2011-06-30
[ [ "Hiramatsu", "Takashi", "" ], [ "Kawasaki", "Masahiro", "" ], [ "Sekiguchi", "Toyokazu", "" ], [ "Yamaguchi", "Masahide", "" ], [ "Yokoyama", "Jun'ichi", "" ] ]
Cosmological evolution of axionic string network is analyzed in terms of field-theoretic simulations in a box of 512^3 grids, which are the largest ever, using a new and more efficient identification scheme of global strings. The scaling parameter is found to be \xi=0.87 +- 0.14 in agreement with previous results. The energy spectrum is calculated precisely using a pseudo power spectrum estimator which significantly reduces the error in the mean reciprocal comoving momentum. The resultant constraint on the axion decay constant leads to f_a <= 3*10^11 GeV. We also discuss implications for the early Universe.
1109.6256
Simon Platzer
Simon Platzer, Stefan Gieseke
Dipole Showers and Automated NLO Matching in Herwig++
14 pages, 14 figures
null
10.1140/epjc/s10052-012-2187-7
DESY 11-162, KA-TP-24-2011, HERWIG-11-01, MCnet-11-24
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We report on the implementation of a coherent dipole shower algorithm along with an automated implementation for dipole subtraction and for performing POWHEG- and MC@NLO-type matching to next-to-leading order (NLO) calculations. Both programs are implemented as add-on modules to the event generator Herwig++. A preliminary tune of parameters to data acquired at LEP, HERA and Drell-Yan pair production at the Tevatron has been performed, and we find an overall very good description which is slightly improved by the NLO matching.
[ { "created": "Wed, 28 Sep 2011 16:08:34 GMT", "version": "v1" } ]
2015-05-30
[ [ "Platzer", "Simon", "" ], [ "Gieseke", "Stefan", "" ] ]
We report on the implementation of a coherent dipole shower algorithm along with an automated implementation for dipole subtraction and for performing POWHEG- and MC@NLO-type matching to next-to-leading order (NLO) calculations. Both programs are implemented as add-on modules to the event generator Herwig++. A preliminary tune of parameters to data acquired at LEP, HERA and Drell-Yan pair production at the Tevatron has been performed, and we find an overall very good description which is slightly improved by the NLO matching.
0808.0812
Ferruccio Feruglio
Ferruccio Feruglio, Claudia Hagedorn, Yin Lin and Luca Merlo
Theory of the Neutrino Mass
elaborated from talks given by the authors at ''Nu HoRIzons'' (February 13-15, 2008, Allahabad, India), ''Neutrino Oscillations in Venice'' (April 15-18, 2008, Venice, Italy), ''Melbourne Neutrino Theory Workshop'' (June 2-4, 2008, Melbourne, Australia) and ''International School of Astroparticle Physics'' (July 16-26, 2008, Valencia, Spain)
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Theoretical aspects of neutrino physics are reviewed, with emphasis on possible explanations of the smallness of neutrino masses and of the peculiar mixing pattern observed in the lepton sector. Some theoretically motivated frameworks, such as those based on spontaneously broken discrete flavour symmetries, are discussed, stressing the importance of low-energy observables, like anomalous magnetic moments, electric dipole moments and lepton flavour violating transitions, to test further features of these models.
[ { "created": "Wed, 6 Aug 2008 16:42:39 GMT", "version": "v1" } ]
2008-08-07
[ [ "Feruglio", "Ferruccio", "" ], [ "Hagedorn", "Claudia", "" ], [ "Lin", "Yin", "" ], [ "Merlo", "Luca", "" ] ]
Theoretical aspects of neutrino physics are reviewed, with emphasis on possible explanations of the smallness of neutrino masses and of the peculiar mixing pattern observed in the lepton sector. Some theoretically motivated frameworks, such as those based on spontaneously broken discrete flavour symmetries, are discussed, stressing the importance of low-energy observables, like anomalous magnetic moments, electric dipole moments and lepton flavour violating transitions, to test further features of these models.
hep-ph/9803246
Salam Tawfiq
Salam Tawfiq, Patrick J. O'Donnel and J. G. Koerner
Charmed Baryon Strong Coupling Constants in a Light-Front Quark Model
21 Pages, No figures, LaTeX, some typos corrected
Phys.Rev. D58 (1998) 054010
10.1103/PhysRevD.58.054010
UTPT-98-03 and MZ-TH/98-08
hep-ph
null
Light-Front quark model spin wave functions are employed to calculate the three independent couplings g_{\Sigma_c \Lambda_c \pi}, f_{\Lambda_{c1} \Sigma_c \pi} and f_{\Lambda^{*}_{c1} \Sigma_c \pi} of S-wave to S-wave and P-wave to S-wave one-pion transitions. It is found that g_{\Sigma_c \Lambda_c \pi}=6.81 MeV^{-1}, f_{\Lambda_{c1} \Sigma_c \pi}=1.16 and f_{\Lambda^{*}_{c1} \Sigma_c \pi}=0.96 . 10^{-4} MeV^{-2}. We also predict decay rates for specific strong transitions of charmed baryons.
[ { "created": "Wed, 4 Mar 1998 21:14:46 GMT", "version": "v1" }, { "created": "Tue, 31 Mar 1998 19:17:52 GMT", "version": "v2" } ]
2009-10-31
[ [ "Tawfiq", "Salam", "" ], [ "O'Donnel", "Patrick J.", "" ], [ "Koerner", "J. G.", "" ] ]
Light-Front quark model spin wave functions are employed to calculate the three independent couplings g_{\Sigma_c \Lambda_c \pi}, f_{\Lambda_{c1} \Sigma_c \pi} and f_{\Lambda^{*}_{c1} \Sigma_c \pi} of S-wave to S-wave and P-wave to S-wave one-pion transitions. It is found that g_{\Sigma_c \Lambda_c \pi}=6.81 MeV^{-1}, f_{\Lambda_{c1} \Sigma_c \pi}=1.16 and f_{\Lambda^{*}_{c1} \Sigma_c \pi}=0.96 . 10^{-4} MeV^{-2}. We also predict decay rates for specific strong transitions of charmed baryons.
0712.3913
Jan Winter
Jan-Christopher Winter, Frank Krauss
Initial-state showering based on colour dipoles connected to incoming parton lines
57 pages, 17 figures
JHEP 0807:040,2008
10.1088/1126-6708/2008/07/040
null
hep-ph
null
A parton-shower model for hadronic collisions based on the emission properties of QCD dipoles is proposed. This proposal therefore extends the well-known radiation pattern of pure final-state colour dipoles to QCD initial-state radiation, both of which are treated perturbatively. Corresponding dipole splitting functions are derived and the kinematics of all dipole splittings is discussed. Application to hadron production in electron-positron annihilation, to Drell-Yan lepton-pair and QCD jet production yields encouraging results.
[ { "created": "Sun, 23 Dec 2007 13:55:28 GMT", "version": "v1" } ]
2009-04-30
[ [ "Winter", "Jan-Christopher", "" ], [ "Krauss", "Frank", "" ] ]
A parton-shower model for hadronic collisions based on the emission properties of QCD dipoles is proposed. This proposal therefore extends the well-known radiation pattern of pure final-state colour dipoles to QCD initial-state radiation, both of which are treated perturbatively. Corresponding dipole splitting functions are derived and the kinematics of all dipole splittings is discussed. Application to hadron production in electron-positron annihilation, to Drell-Yan lepton-pair and QCD jet production yields encouraging results.
2203.16352
Yen-Jie Lee
Liliana Apolin\'ario (1 and 2), Yen-Jie Lee (3), Michael Winn (4) ((1) LIP, (2) Instituto Superior T\'ecnico (IST), Universidade de Lisboa, (3) Massachusetts Institute of Technology (MIT), (4) D\'epartement de Physique Nucl\'eaire (DPhN), Institut de Recherche sur les lois Fondamentales de l'Univers (IRFU) CEA - Saclay)
Heavy quarks and jets as probes of the QGP
null
Progress in Particle and Nuclear Physics, 103990 (2022)
10.1016/j.ppnp.2022.103990
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Quark-Gluon Plasma (QGP), a QCD state of matter created in ultra-relativistic heavy-ion collisions, has remarkable properties, including, for example, a low shear viscosity over entropy ratio. By detecting the collection of low-momentum particles that arise from the collision, it is possible to gain quantitative insight into the created matter. However, its fast evolution and thermalization properties remain elusive. Only using high momentum objects as probes of QGP can unveil its constituents at different wavelengths. In this review, we attempt to provide a comprehensive picture of what was, so far, possible to infer about QGP given our current theoretical understanding of jets, heavy-flavor, and quarkonia. We will bridge the resulting qualitative picture to the experimental observations done at the LHC and RHIC. We will focus on the phenomenological description of experimental observations, provide a brief analytical summary of the description of hard probes, and an outlook on the main difficulties we will need to surpass in the following years. To benchmark QGP-related effects, we will also address nuclear modifications to the initial state and hadronization effects.
[ { "created": "Wed, 30 Mar 2022 14:30:39 GMT", "version": "v1" }, { "created": "Fri, 29 Jul 2022 19:00:58 GMT", "version": "v2" }, { "created": "Mon, 19 Sep 2022 15:11:50 GMT", "version": "v3" } ]
2022-09-20
[ [ "Apolinário", "Liliana", "", "1 and 2" ], [ "Lee", "Yen-Jie", "" ], [ "Winn", "Michael", "" ] ]
Quark-Gluon Plasma (QGP), a QCD state of matter created in ultra-relativistic heavy-ion collisions, has remarkable properties, including, for example, a low shear viscosity over entropy ratio. By detecting the collection of low-momentum particles that arise from the collision, it is possible to gain quantitative insight into the created matter. However, its fast evolution and thermalization properties remain elusive. Only using high momentum objects as probes of QGP can unveil its constituents at different wavelengths. In this review, we attempt to provide a comprehensive picture of what was, so far, possible to infer about QGP given our current theoretical understanding of jets, heavy-flavor, and quarkonia. We will bridge the resulting qualitative picture to the experimental observations done at the LHC and RHIC. We will focus on the phenomenological description of experimental observations, provide a brief analytical summary of the description of hard probes, and an outlook on the main difficulties we will need to surpass in the following years. To benchmark QGP-related effects, we will also address nuclear modifications to the initial state and hadronization effects.
0801.2232
Valery Lyubovitskij
Amand Faessler, Thomas Gutsche, Valery E. Lyubovitskij, Yong-Liang Ma
Molecular structure of the Bs0*(5725) and Bs1(5778) bottom-strange mesons
21 pages, 7 figures
Phys.Rev.D77:114013,2008
10.1103/PhysRevD.77.114013
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss a possible interpretation of the scalar Bs0*(5725) and axial Bs1(5778) bottom-strange mesons as hadronic molecules - bound states of B K and B* K mesons, respectively. Using a phenomenological Lagrangian approach we analyze the strong Bs0* to Bs pi0, Bs1 to Bs* pi0 and the radiative Bs0* to Bs* gamma, Bs1 to Bs gamma, Bs1 to Bs* gamma, Bs1 to Bs0* gamma decays. We give predictions for the decay properties: effective couplings and decay widths.
[ { "created": "Tue, 15 Jan 2008 09:08:27 GMT", "version": "v1" }, { "created": "Wed, 11 Jun 2008 14:25:58 GMT", "version": "v2" } ]
2008-11-26
[ [ "Faessler", "Amand", "" ], [ "Gutsche", "Thomas", "" ], [ "Lyubovitskij", "Valery E.", "" ], [ "Ma", "Yong-Liang", "" ] ]
We discuss a possible interpretation of the scalar Bs0*(5725) and axial Bs1(5778) bottom-strange mesons as hadronic molecules - bound states of B K and B* K mesons, respectively. Using a phenomenological Lagrangian approach we analyze the strong Bs0* to Bs pi0, Bs1 to Bs* pi0 and the radiative Bs0* to Bs* gamma, Bs1 to Bs gamma, Bs1 to Bs* gamma, Bs1 to Bs0* gamma decays. We give predictions for the decay properties: effective couplings and decay widths.
1206.6044
Boris Kerbikov
B. Kerbikov and M. Andreichikov
Dense Quark Matter Conductivity in Ultra-Intense Magnetic Field
3 pages, 0 figures
null
10.1134/S0021364012180051
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Heavy-ion collisions generate a huge magnetic field of the order of $10^{18} G $ for the duration of about 0.2 fm/c. This time may become an order of magnitude longer if the electrical conductivity of quark matter is large. We calculate the conductivity in the regime of high density and show that contrary to naive expectations it only weakly depends on the MF.
[ { "created": "Tue, 26 Jun 2012 16:34:55 GMT", "version": "v1" }, { "created": "Wed, 27 Jun 2012 16:29:47 GMT", "version": "v2" }, { "created": "Wed, 15 Aug 2012 09:17:34 GMT", "version": "v3" } ]
2015-06-05
[ [ "Kerbikov", "B.", "" ], [ "Andreichikov", "M.", "" ] ]
Heavy-ion collisions generate a huge magnetic field of the order of $10^{18} G $ for the duration of about 0.2 fm/c. This time may become an order of magnitude longer if the electrical conductivity of quark matter is large. We calculate the conductivity in the regime of high density and show that contrary to naive expectations it only weakly depends on the MF.
1507.02283
Thomas Flacke
Giacomo Cacciapaglia, Haiying Cai, Aldo Deandrea, Thomas Flacke, Seung J. Lee, and Alberto Parolini
Composite scalars at the LHC: the Higgs, the Sextet and the Octet
39 pages, 9 figures, 4 tables. Agrees with version published in JHEP. Changes w.r.t. v1: Fig. 1 added for illustration, U(1) charge in Tab. 1 corrected, references added
JHEP 1511 (2015) 201
10.1007/JHEP11(2015)201
LYCEN-2015-05
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a phenomenological theory of scalar particles that transform as a sextet and an octet of QCD interactions. These particles may arise as light bound states of a fundamental dynamics giving rise to a composite Higgs boson and partial compositeness for the top. As a concrete example, we discuss an explicit UV completion based on the SU(4)/Sp(4) coset, where QCD colour is carried by additional fundamental fermions charged under the confining gauge group. Top partners, as well as potentially even lighter coloured scalars, arise as bound states of the coloured fermions. We study production and detection at LHC Run I and II of the octet and sextet, setting lower limits on masses and couplings to Standard Model particles using existing 8 TeV analyses. We finally explore prospects for the ongoing 13 TeV Run II: we focus on final states with two same sign leptons, that have the potential to discriminate the sextet.
[ { "created": "Wed, 8 Jul 2015 20:00:40 GMT", "version": "v1" }, { "created": "Mon, 28 Dec 2015 14:27:35 GMT", "version": "v2" } ]
2015-12-29
[ [ "Cacciapaglia", "Giacomo", "" ], [ "Cai", "Haiying", "" ], [ "Deandrea", "Aldo", "" ], [ "Flacke", "Thomas", "" ], [ "Lee", "Seung J.", "" ], [ "Parolini", "Alberto", "" ] ]
We present a phenomenological theory of scalar particles that transform as a sextet and an octet of QCD interactions. These particles may arise as light bound states of a fundamental dynamics giving rise to a composite Higgs boson and partial compositeness for the top. As a concrete example, we discuss an explicit UV completion based on the SU(4)/Sp(4) coset, where QCD colour is carried by additional fundamental fermions charged under the confining gauge group. Top partners, as well as potentially even lighter coloured scalars, arise as bound states of the coloured fermions. We study production and detection at LHC Run I and II of the octet and sextet, setting lower limits on masses and couplings to Standard Model particles using existing 8 TeV analyses. We finally explore prospects for the ongoing 13 TeV Run II: we focus on final states with two same sign leptons, that have the potential to discriminate the sextet.
hep-ph/0703075
Gianpiero Mangano
Alfredo G. Cocco, Gianpiero Mangano, Marcello Messina
Probing Low Energy Neutrino Backgrounds with Neutrino Capture on Beta Decaying Nuclei
Includes a discussion of local relic neutrino density effect on neutrino capture rate. Accepted for publication in JCAP
JCAP 0706:015,2007; J.Phys.Conf.Ser.110:082014,2008
10.1088/1742-6596/110/8/082014
null
hep-ph astro-ph
null
We study the interaction of low energy neutrinos on nuclei that spontaneously undergo beta decay showing that the product of the cross section times neutrino velocity takes values as high as 10^{-42} cm^2 c for some specific nuclei that decay via allowed transitions. The absence of energy threshold and the value of the cross section single out these processes as a promising though very demanding approach for future experiments aimed at a direct detection of low energy neutrino backgrounds such as the cosmological relic neutrinos.
[ { "created": "Wed, 7 Mar 2007 18:35:11 GMT", "version": "v1" }, { "created": "Mon, 11 Jun 2007 09:12:53 GMT", "version": "v2" } ]
2009-04-17
[ [ "Cocco", "Alfredo G.", "" ], [ "Mangano", "Gianpiero", "" ], [ "Messina", "Marcello", "" ] ]
We study the interaction of low energy neutrinos on nuclei that spontaneously undergo beta decay showing that the product of the cross section times neutrino velocity takes values as high as 10^{-42} cm^2 c for some specific nuclei that decay via allowed transitions. The absence of energy threshold and the value of the cross section single out these processes as a promising though very demanding approach for future experiments aimed at a direct detection of low energy neutrino backgrounds such as the cosmological relic neutrinos.
2106.09740
Zachary Johnson
Patrick Barnes, Zachary Johnson, Aaron Pierce, Bibhushan Shakya
Indirect Detection of Secluded Supersymmetric Dark Matter
30 pages, 10 figures
null
10.1103/PhysRevD.105.035005
CERN-TH-2021-089, DESY 21-091, LCTP-21-13
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Weak-scale secluded sector dark matter can reproduce the observed dark matter relic density with thermal freeze-out within that sector. If nature is supersymmetric, three portals to the visible sector - a gauge portal, a Higgs portal, and a gaugino portal - are present. We present gamma ray spectra relevant for indirect detection of dark matter annihilation in such setups. Since symmetries in the secluded sector can stabilize dark matter, $R$-parity is unnecessary, and we investigate the impact of $R$-parity violation on annihilation spectra. We present limits from the Fermi Large Area Telescope observations of dwarf galaxies and projections for Cherenkov Telescope Array observations of the galactic center. Many of our results are also applicable to generic, non-supersymmetric setups.
[ { "created": "Thu, 17 Jun 2021 18:00:05 GMT", "version": "v1" } ]
2022-02-16
[ [ "Barnes", "Patrick", "" ], [ "Johnson", "Zachary", "" ], [ "Pierce", "Aaron", "" ], [ "Shakya", "Bibhushan", "" ] ]
Weak-scale secluded sector dark matter can reproduce the observed dark matter relic density with thermal freeze-out within that sector. If nature is supersymmetric, three portals to the visible sector - a gauge portal, a Higgs portal, and a gaugino portal - are present. We present gamma ray spectra relevant for indirect detection of dark matter annihilation in such setups. Since symmetries in the secluded sector can stabilize dark matter, $R$-parity is unnecessary, and we investigate the impact of $R$-parity violation on annihilation spectra. We present limits from the Fermi Large Area Telescope observations of dwarf galaxies and projections for Cherenkov Telescope Array observations of the galactic center. Many of our results are also applicable to generic, non-supersymmetric setups.
1707.02717
Per Osland
P. Osland, A. A. Pankov and A. V. Tsytrinov
Probing $Z$-$Z'$ mixing with ATLAS and CMS resonant diboson production data at the LHC at $\sqrt{s}=13$ TeV
7 pages; v2: PRD version
Phys. Rev. D 96, 055040 (2017)
10.1103/PhysRevD.96.055040
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The study of electroweak boson pair production provides a powerful test of the spontaneously broken gauge symmetry of the Standard Model (SM) and can be used to search for new phenomena beyond the SM. Extra neutral vector bosons $Z'$ decaying to charged gauge vector boson pairs $W^+W^-$ are predicted in many scenarios of new physics, including models with an extended gauge sector. The diboson production allows to place stringent constraints on the $Z$-$Z'$ mixing factor $\xi$ and $Z'$ mass, $M_{Z'}$. We present the $Z'$ exclusion region in the $\xi-M_{Z'}$ plane for the first time by using data comprised of $pp$ collisions at $\sqrt{s}=13$ TeV and recorded by the ATLAS and CMS detectors at the CERN LHC, with integrated luminosities of 13.2 and 35.9 fb$^{-1}$, respectively. The exclusion region has been significantly extended compared to that obtained from the previous analysis performed with Tevatron data as well as with LHC data collected at 7 and 8 TeV. Also, we found that these constraints on the $Z$-$Z'$ mixing factor are more severe than those derived from the global analysis of electroweak data. Further improvement on the constraining of this mixing can be achieved from the analysis of data to be collected at higher luminosity.
[ { "created": "Mon, 10 Jul 2017 07:04:27 GMT", "version": "v1" }, { "created": "Wed, 13 Sep 2017 15:51:06 GMT", "version": "v2" } ]
2017-10-04
[ [ "Osland", "P.", "" ], [ "Pankov", "A. A.", "" ], [ "Tsytrinov", "A. V.", "" ] ]
The study of electroweak boson pair production provides a powerful test of the spontaneously broken gauge symmetry of the Standard Model (SM) and can be used to search for new phenomena beyond the SM. Extra neutral vector bosons $Z'$ decaying to charged gauge vector boson pairs $W^+W^-$ are predicted in many scenarios of new physics, including models with an extended gauge sector. The diboson production allows to place stringent constraints on the $Z$-$Z'$ mixing factor $\xi$ and $Z'$ mass, $M_{Z'}$. We present the $Z'$ exclusion region in the $\xi-M_{Z'}$ plane for the first time by using data comprised of $pp$ collisions at $\sqrt{s}=13$ TeV and recorded by the ATLAS and CMS detectors at the CERN LHC, with integrated luminosities of 13.2 and 35.9 fb$^{-1}$, respectively. The exclusion region has been significantly extended compared to that obtained from the previous analysis performed with Tevatron data as well as with LHC data collected at 7 and 8 TeV. Also, we found that these constraints on the $Z$-$Z'$ mixing factor are more severe than those derived from the global analysis of electroweak data. Further improvement on the constraining of this mixing can be achieved from the analysis of data to be collected at higher luminosity.
hep-ph/9812510
Deog Ki Hong
Deog Ki Hong
An effective field theory of QCD at high density
12 pages ReVTeX, 4 eps-figures included using epsf.sty: The gap equation is re-analyzed in the HDL approximation
Phys.Lett. B473 (2000) 118-125
10.1016/S0370-2693(99)01472-0
SNUTP 98-147, HUTP-98/A089, BUHEP-98-30
hep-ph hep-th nucl-th
null
We derive a (Wilsonian) effective field theory of QCD at finite density by integrating out the states in the Dirac sea when the chemical potential $\mu\gg\Lambda_{\rm QCD}$. The quark-gluon coupling is effectively (1+1)-dimensional and the theory contains four-quark operators which become relevant as we approach to the Fermi sea. By calculating the one-loop vacuum polarization tensor in the effective theory, we find the electric gluons have a screening mass, $M\sim g_s\mu$, while the static magnetic gluons are unscreened. We then investigate the gap equations for color anti-triplet Cooper pairs by including both gluon-exchange interactions and the marginal four-quark interactions in the effective theory.
[ { "created": "Mon, 28 Dec 1998 15:56:06 GMT", "version": "v1" }, { "created": "Wed, 27 Jan 1999 17:22:54 GMT", "version": "v2" }, { "created": "Wed, 17 Mar 1999 20:10:45 GMT", "version": "v3" }, { "created": "Tue, 2 Nov 1999 02:40:07 GMT", "version": "v4" } ]
2009-10-31
[ [ "Hong", "Deog Ki", "" ] ]
We derive a (Wilsonian) effective field theory of QCD at finite density by integrating out the states in the Dirac sea when the chemical potential $\mu\gg\Lambda_{\rm QCD}$. The quark-gluon coupling is effectively (1+1)-dimensional and the theory contains four-quark operators which become relevant as we approach to the Fermi sea. By calculating the one-loop vacuum polarization tensor in the effective theory, we find the electric gluons have a screening mass, $M\sim g_s\mu$, while the static magnetic gluons are unscreened. We then investigate the gap equations for color anti-triplet Cooper pairs by including both gluon-exchange interactions and the marginal four-quark interactions in the effective theory.
1504.07244
Yue Zhang
Hooman Davoudiasl, Yue Zhang
Baryon Number Violation via Majorana Neutrinos in the Early Universe, at the LHC, and Deep Underground
5 pages, 3 figures. references and discussions added
Phys. Rev. D 92, 016005 (2015)
10.1103/PhysRevD.92.016005
CALT-TH-2015-023
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose and investigate a novel, minimal, and experimentally testable framework for baryogenesis, dubbed dexiogenesis, using baryon number violating effective interactions of right-handed Majorana neutrinos responsible for the seesaw mechanism. The distinct LHC signature of our framework is same-sign top quark final states, possibly originating from displaced vertices. The region of parameters relevant for LHC phenomenology can also yield concomitant signals in nucleon decay experiments. We provide a simple ultraviolet origin for our effective operators, by adding a color-triplet scalar, which could ultimately arise from a grand unified theory.
[ { "created": "Mon, 27 Apr 2015 20:01:06 GMT", "version": "v1" }, { "created": "Thu, 7 May 2015 22:00:59 GMT", "version": "v2" } ]
2015-07-22
[ [ "Davoudiasl", "Hooman", "" ], [ "Zhang", "Yue", "" ] ]
We propose and investigate a novel, minimal, and experimentally testable framework for baryogenesis, dubbed dexiogenesis, using baryon number violating effective interactions of right-handed Majorana neutrinos responsible for the seesaw mechanism. The distinct LHC signature of our framework is same-sign top quark final states, possibly originating from displaced vertices. The region of parameters relevant for LHC phenomenology can also yield concomitant signals in nucleon decay experiments. We provide a simple ultraviolet origin for our effective operators, by adding a color-triplet scalar, which could ultimately arise from a grand unified theory.
hep-ph/0009084
Peter Uwer
W. Bernreuther (RWTH Aachen), A. Brandenburg (DESY), P. Uwer (Saclay)
Parity-violating 3-jet observables for massive quarks to order alphas^2 in e+e- annihilation
5 pages, Talk given at International Euroconference in Quantum Chromodynamics: 15 Years of the QCD - Montpellier Conference (QCD 00), Montpellier, France, 6-12 Jul 2000
Nucl.Phys.Proc.Suppl. 96 (2001) 79-83
10.1016/S0920-5632(01)01112-4
DESY 00-129, SPhT--T00/124
hep-ph
null
In this talk we discuss the calculation of the QCD corrections to parity-violating 3-jet observables in e^+e^- collisions, keeping the full quark mass dependence.
[ { "created": "Thu, 7 Sep 2000 15:22:31 GMT", "version": "v1" } ]
2009-10-31
[ [ "Bernreuther", "W.", "", "RWTH Aachen" ], [ "Brandenburg", "A.", "", "DESY" ], [ "Uwer", "P.", "", "Saclay" ] ]
In this talk we discuss the calculation of the QCD corrections to parity-violating 3-jet observables in e^+e^- collisions, keeping the full quark mass dependence.
2303.00535
Qiang Zhao
Ye Cao, Yin Cheng, and Qiang Zhao
Resolving the polarization puzzles in $D^0\to VV$
Revtex, 2 figures, 15 pages; version accepted by PRD
null
null
null
hep-ph
http://creativecommons.org/publicdomain/zero/1.0/
We carry out a systematic analysis of the Cabbibo-favored (CF) and singly Cabbibo-suppressed (SCS) decays of $D^0\to VV$, and demonstrate that the long-distance mechanism due to the final-state interactions (FSIs) can provide a natural explanation for these mysterious polarization puzzles observed in $D^0\to VV$ in experiments. More observables, which can be measured at BESIII and possibly at LHCb, are also suggested.
[ { "created": "Wed, 1 Mar 2023 14:22:55 GMT", "version": "v1" }, { "created": "Thu, 2 Mar 2023 07:52:23 GMT", "version": "v2" }, { "created": "Sat, 11 Nov 2023 13:46:58 GMT", "version": "v3" }, { "created": "Mon, 11 Mar 2024 10:09:00 GMT", "version": "v4" } ]
2024-03-12
[ [ "Cao", "Ye", "" ], [ "Cheng", "Yin", "" ], [ "Zhao", "Qiang", "" ] ]
We carry out a systematic analysis of the Cabbibo-favored (CF) and singly Cabbibo-suppressed (SCS) decays of $D^0\to VV$, and demonstrate that the long-distance mechanism due to the final-state interactions (FSIs) can provide a natural explanation for these mysterious polarization puzzles observed in $D^0\to VV$ in experiments. More observables, which can be measured at BESIII and possibly at LHCb, are also suggested.
1109.1340
M.I. Vyazovsky
M.A. Braun, M.Yu. Salykin and M.I. Vyazovsky (Saint-Petersburg State University, Russia)
On the inclusive gluon production in the Lipatov effective action formalism
15 pages, 7 figures; some references added; to be published in Eur.Phys.Jour. C
null
10.1140/epjc/s10052-012-1864-x
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The process of gluon production in quark-nucleus collisions is studied in the framework of Lipatov's effective action formalism. The relevant simplifications and rules for longitudinal integrations are discussed in detail. The results obtained with the help of these rules correspond to the purely transversal formalism based on effective vertices in the transversal space.
[ { "created": "Wed, 7 Sep 2011 02:31:52 GMT", "version": "v1" }, { "created": "Fri, 13 Jan 2012 00:48:30 GMT", "version": "v2" } ]
2015-05-30
[ [ "Braun", "M. A.", "", "Saint-Petersburg State\n University, Russia" ], [ "Salykin", "M. Yu.", "", "Saint-Petersburg State\n University, Russia" ], [ "Vyazovsky", "M. I.", "", "Saint-Petersburg State\n University, Russia" ] ]
The process of gluon production in quark-nucleus collisions is studied in the framework of Lipatov's effective action formalism. The relevant simplifications and rules for longitudinal integrations are discussed in detail. The results obtained with the help of these rules correspond to the purely transversal formalism based on effective vertices in the transversal space.
0812.3511
Ji-Haeng Huh
Kyu Jung Bae, Ji-Haeng Huh, Jihn E. Kim, Bumseok Kyae and Raoul D. Viollier
White dwarf axions, PAMELA data, and flipped-SU(5)
13 pages and 2 figures
Nucl.Phys.B817:58-75,2009
10.1016/j.nuclphysb.2009.03.015
null
hep-ph astro-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, there are two hints arising from physics beyond the standard model. One is a possible energy loss mechanism due to emission of very weakly interacting light particles from white dwarf stars, with a coupling strength ~ 0.7x10^{-13}, and another is the high energy positrons observed by the PAMELA satellite experiment. We construct a supersymmetric flipped-SU(5) model, SU(5)xU(1)_X with appropriate additional symmetries, [U(1)_H]_{gauge}x[U(1)_RxU(1)_\Gamma]_{global}xZ_2, such that these are explained by a very light electrophilic axion of mass 0.5 meV from the spontaneously broken U(1)_\Gamma and two component cold dark matters from Z_2 parity. We show that in the flipped-SU(5) there exists a basic mechanism for allowing excess positrons through the charged SU(2) singlet leptons, but not allowing anti-proton excess due to the absence of the SU(2) singlet quarks. We show the discovery potential of the charged SU(2) singlet E at the LHC experiments by observing the electron and positron spectrum. With these symmetries, we also comment on the mass hierarchy between the top and bottom quarks.
[ { "created": "Thu, 18 Dec 2008 11:50:08 GMT", "version": "v1" }, { "created": "Wed, 7 Jan 2009 13:12:16 GMT", "version": "v2" } ]
2010-01-15
[ [ "Bae", "Kyu Jung", "" ], [ "Huh", "Ji-Haeng", "" ], [ "Kim", "Jihn E.", "" ], [ "Kyae", "Bumseok", "" ], [ "Viollier", "Raoul D.", "" ] ]
Recently, there are two hints arising from physics beyond the standard model. One is a possible energy loss mechanism due to emission of very weakly interacting light particles from white dwarf stars, with a coupling strength ~ 0.7x10^{-13}, and another is the high energy positrons observed by the PAMELA satellite experiment. We construct a supersymmetric flipped-SU(5) model, SU(5)xU(1)_X with appropriate additional symmetries, [U(1)_H]_{gauge}x[U(1)_RxU(1)_\Gamma]_{global}xZ_2, such that these are explained by a very light electrophilic axion of mass 0.5 meV from the spontaneously broken U(1)_\Gamma and two component cold dark matters from Z_2 parity. We show that in the flipped-SU(5) there exists a basic mechanism for allowing excess positrons through the charged SU(2) singlet leptons, but not allowing anti-proton excess due to the absence of the SU(2) singlet quarks. We show the discovery potential of the charged SU(2) singlet E at the LHC experiments by observing the electron and positron spectrum. With these symmetries, we also comment on the mass hierarchy between the top and bottom quarks.
0912.2323
BingAn Li
Bing an Li
Chiral field theory of $0^{-+}$ glueball
29 pages
Phys.Rev.D81:114002,2010
10.1103/PhysRevD.81.114002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A chiral field theory of $0^{-+}$ glueball is presented. By adding a $0^{-+}$ glueball field to a successful Lagrangian of chiral field theory of pseudoscalar, vector, and axial-vector mesons, the Lagrangian of this theory is constructed. The couplings between the pseodoscalar glueball field and mesons are via U(1) anomaly revealed. Qualitative study of the physical processes of the $0^{-+}$ glueball of $m=1.405\textrm{GeV}$ is presented. The theoretical predictions can be used to identify the $0^{-+}$ glueball.
[ { "created": "Fri, 11 Dec 2009 19:04:25 GMT", "version": "v1" }, { "created": "Mon, 22 Feb 2010 15:23:05 GMT", "version": "v2" } ]
2014-11-20
[ [ "Li", "Bing an", "" ] ]
A chiral field theory of $0^{-+}$ glueball is presented. By adding a $0^{-+}$ glueball field to a successful Lagrangian of chiral field theory of pseudoscalar, vector, and axial-vector mesons, the Lagrangian of this theory is constructed. The couplings between the pseodoscalar glueball field and mesons are via U(1) anomaly revealed. Qualitative study of the physical processes of the $0^{-+}$ glueball of $m=1.405\textrm{GeV}$ is presented. The theoretical predictions can be used to identify the $0^{-+}$ glueball.
1203.3956
Jian Zhou Mr.
Zuo-Tang Liang, Andreas Metz, Daniel Pitonyak, Andreas Sch\"afer, Yu-Kun Song, Jian Zhou
Double spin asymmetry A_{LT} in direct photon production
9 pages, 1 figure
null
10.1016/j.physletb.2012.04.072
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the longitudinal-transverse double spin asymmetry $A_{LT}$ for direct photon production in nucleon-nucleon scattering by using the collinear twist-3 approach. This asymmetry, which, for instance, could be measured at RHIC, contains a complete set of collinear twist-3 correlation functions in a transversely polarized nucleon.
[ { "created": "Sun, 18 Mar 2012 14:40:35 GMT", "version": "v1" } ]
2015-06-04
[ [ "Liang", "Zuo-Tang", "" ], [ "Metz", "Andreas", "" ], [ "Pitonyak", "Daniel", "" ], [ "Schäfer", "Andreas", "" ], [ "Song", "Yu-Kun", "" ], [ "Zhou", "Jian", "" ] ]
We study the longitudinal-transverse double spin asymmetry $A_{LT}$ for direct photon production in nucleon-nucleon scattering by using the collinear twist-3 approach. This asymmetry, which, for instance, could be measured at RHIC, contains a complete set of collinear twist-3 correlation functions in a transversely polarized nucleon.
1512.05751
Sylvain Fichet
Sylvain Fichet, Gero von Gersdorff, Christophe Royon
Scattering Light by Light at 750 GeV at the LHC
6 pages, minor changes, references added. Matches PRD version
Phys. Rev. D 93, 075031 (2016)
10.1103/PhysRevD.93.075031
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the possibility that the diphoton excess at 750 GeV is caused by a new scalar resonance produced in photon fusion. This scenario is parametrised by only one relevant effective couplings and is thus minimal. We show that this setup can reproduce both the production rate and width of the resonance, and is not in conflict with the 8 TeV limits on the diphoton cross section. The scenario also predicts event rates for $WW$, $ZZ$, $Z\gamma$ final states. We suggest to perform precision measurements by studying light-by-light scattering with intact protons detected in forward detectors. We construct a simple model that shows that the required couplings can be achieved with new vectorlike, uncolored fermions (with a strong Yukawa coupling to the resonance) which may also account for the required width.
[ { "created": "Thu, 17 Dec 2015 20:21:55 GMT", "version": "v1" }, { "created": "Tue, 26 Apr 2016 16:33:01 GMT", "version": "v2" } ]
2016-04-27
[ [ "Fichet", "Sylvain", "" ], [ "von Gersdorff", "Gero", "" ], [ "Royon", "Christophe", "" ] ]
We consider the possibility that the diphoton excess at 750 GeV is caused by a new scalar resonance produced in photon fusion. This scenario is parametrised by only one relevant effective couplings and is thus minimal. We show that this setup can reproduce both the production rate and width of the resonance, and is not in conflict with the 8 TeV limits on the diphoton cross section. The scenario also predicts event rates for $WW$, $ZZ$, $Z\gamma$ final states. We suggest to perform precision measurements by studying light-by-light scattering with intact protons detected in forward detectors. We construct a simple model that shows that the required couplings can be achieved with new vectorlike, uncolored fermions (with a strong Yukawa coupling to the resonance) which may also account for the required width.
0805.0698
Cecilia Tarantino
Cecilia Tarantino
B-Physics: Theoretical Predictions in the LHC Era
8 pages, to appear in the proceedings of "V Italian Workshop on the p-p Physics at the LHC" (Perugia, 30th January - 2nd February, 2008), two references added
Nuovo Cim.B123:437-443,2008
10.1393/ncb/i2008-10527-5
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the status of the theoretical predictions of some interesting b-physics observables that are sensitive to New Physics and can be measured at the LHC.
[ { "created": "Tue, 6 May 2008 11:15:41 GMT", "version": "v1" }, { "created": "Wed, 14 May 2008 12:52:34 GMT", "version": "v2" } ]
2010-11-11
[ [ "Tarantino", "Cecilia", "" ] ]
We discuss the status of the theoretical predictions of some interesting b-physics observables that are sensitive to New Physics and can be measured at the LHC.
hep-ph/0103321
David London
Alakabha Datta, C.S. Kim and David London
Measuring sin 2\beta in Bs(t) -> phi K_s
15 pages, LaTeX, 4 figures
Phys.Lett.B507:153-161,2001
10.1016/S0370-2693(01)00427-0
UdeM-GPP-TH-01-84
hep-ph hep-ex
null
We show that, unlike other pure b -> d penguin processes, the decay Bs(t) -> phi K_s is dominated by a single amplitude, that of the internal t-quark. The contributions of the u- and c-quark operators each vanish due to a cancellation between the (V-A) \otimes (V-A) and (V-A) \otimes (V+A) matrix elements. Thus, the indirect CP asymmetry in this decay probes sin 2\beta. Although this cancellation is complete only for certain values of the s- and b-quark masses, the theoretical uncertainty on sin 2\beta is still less than 10% over most (~80%) of the parameter space. By measuring the direct CP asymmetry, one can get a better idea of the probable error on sin 2\beta.
[ { "created": "Thu, 29 Mar 2001 15:16:26 GMT", "version": "v1" } ]
2014-11-17
[ [ "Datta", "Alakabha", "" ], [ "Kim", "C. S.", "" ], [ "London", "David", "" ] ]
We show that, unlike other pure b -> d penguin processes, the decay Bs(t) -> phi K_s is dominated by a single amplitude, that of the internal t-quark. The contributions of the u- and c-quark operators each vanish due to a cancellation between the (V-A) \otimes (V-A) and (V-A) \otimes (V+A) matrix elements. Thus, the indirect CP asymmetry in this decay probes sin 2\beta. Although this cancellation is complete only for certain values of the s- and b-quark masses, the theoretical uncertainty on sin 2\beta is still less than 10% over most (~80%) of the parameter space. By measuring the direct CP asymmetry, one can get a better idea of the probable error on sin 2\beta.
hep-ph/0607008
Enrique Fernandez-Martinez
E. Couce
Measuring Leptonic CP Violation with a Water Cerenkov
Talk given at 41st Rencontres de Moriond on Electroweak Interactions and Unified Theories, La Thuile, Aosta Valley, Italy, 11-18 Mar 2006
null
null
null
hep-ph
null
In this talk, we present the physics case for a megaton Water Cerenkov detector in addressing some of the still pending questions in neutrino oscillations physics, particularly the measurement of leptonic CP violation. We compare different future beams that could profit from a water detector and analyse, for the case $\theta_{13} \approx 3^\circ$ (the limit that can be reached by under-construction experiments), the signal-to-background rate for a $\beta$-beam setup with the radioactive ions accelerated to $\gamma = 350$.
[ { "created": "Sat, 1 Jul 2006 21:33:58 GMT", "version": "v1" } ]
2007-05-23
[ [ "Couce", "E.", "" ] ]
In this talk, we present the physics case for a megaton Water Cerenkov detector in addressing some of the still pending questions in neutrino oscillations physics, particularly the measurement of leptonic CP violation. We compare different future beams that could profit from a water detector and analyse, for the case $\theta_{13} \approx 3^\circ$ (the limit that can be reached by under-construction experiments), the signal-to-background rate for a $\beta$-beam setup with the radioactive ions accelerated to $\gamma = 350$.
hep-ph/9602429
Urs Buergi
Urs Buergi
Charged Pion-Pair Production and Pion Polarizabilities to two Loops
35 pages, LaTeX, uses epsf.sty and cite.sty, 15 postscript pictures included
Nucl.Phys.B479:392-426,1996
10.1016/0550-3213(96)00454-3
BUTP-96/02
hep-ph
null
We evaluate the amplitude for gamma gamma --> pi^+ pi^- to two loops in the framework of chiral perturbation theory.The three new coupling constants that enter the result at this order in the low-energy expansion are estimated via resonance saturation. We discuss in addition the crossed channel processes gamma pi^+ --> gamma pi^+ - in particular the charged pion polarizabilities - to the same accuracy. The predictions are compared with available experimental information.
[ { "created": "Thu, 29 Feb 1996 11:55:26 GMT", "version": "v1" } ]
2011-07-19
[ [ "Buergi", "Urs", "" ] ]
We evaluate the amplitude for gamma gamma --> pi^+ pi^- to two loops in the framework of chiral perturbation theory.The three new coupling constants that enter the result at this order in the low-energy expansion are estimated via resonance saturation. We discuss in addition the crossed channel processes gamma pi^+ --> gamma pi^+ - in particular the charged pion polarizabilities - to the same accuracy. The predictions are compared with available experimental information.
hep-ph/9511360
Khan Hafsa
H. Khan and P. Hoodbhoy
Beyond The Colour-Singlet Model For Inelastic J/\psi Photoproduction
15 pages, latex, no figures
Phys. Lett. B382 (1996) 189
10.1016/0370-2693(96)00588-6
null
hep-ph
null
Bound-state corrections to $J/\psi$ production from almost real photons are calculated in the colour-singlet model. A systematic, gauge-invariant, theory of hard quarkonium processes is used upto $O(v^2)$, where $v$ is the relative velocity of the quarks. The internal structure of the meson is characterised by two parameters, $\epsilon_B/M$ and $\nabla^2 \phi(0)/M^2 \phi(0)$, in addition to the usual wavefunction at the origin $\phi(0)$. These parameters are constrained to be consistent with measured leptonic decay of the $J/\psi$ and hadronic and radiative decays of $\eta_c$.
[ { "created": "Fri, 17 Nov 1995 18:11:44 GMT", "version": "v1" } ]
2016-09-01
[ [ "Khan", "H.", "" ], [ "Hoodbhoy", "P.", "" ] ]
Bound-state corrections to $J/\psi$ production from almost real photons are calculated in the colour-singlet model. A systematic, gauge-invariant, theory of hard quarkonium processes is used upto $O(v^2)$, where $v$ is the relative velocity of the quarks. The internal structure of the meson is characterised by two parameters, $\epsilon_B/M$ and $\nabla^2 \phi(0)/M^2 \phi(0)$, in addition to the usual wavefunction at the origin $\phi(0)$. These parameters are constrained to be consistent with measured leptonic decay of the $J/\psi$ and hadronic and radiative decays of $\eta_c$.
2405.13727
Harleen Dahiya Dr.
Shubham Sharma, Satyajit Puhan, Narinder Kumar, Harleen Dahiya
TMD Relations: Insights from a Light-Front Quark-Diquark Model
40 pages and 3 tables
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we have established the relations between the T-even proton transverse momentum-dependent parton distributions (TMDs) at all twist levels up to twist-4 using the light-front quark diquark model (LFQDM). From the parameterization equations of TMDs, we have found that there are multiple ways by which a particular TMD can be expressed in terms of the helicities of the proton in the initial and final states. For the first time, we have presented a parameterization table that can be applied to the derivation and recognition of proton TMDs based on their helicity. We have constructed the linear and quadratic relationships of TMDs at the intra-twist and inter-twist levels within the same model. We have also looked at the inequality relations that TMDs follow. Additionally, to provide an easy access to the calculations, amplitude matrices have been expressed in the form of TMDs over all the possible helicities of the diquark.
[ { "created": "Wed, 22 May 2024 15:20:56 GMT", "version": "v1" } ]
2024-05-24
[ [ "Sharma", "Shubham", "" ], [ "Puhan", "Satyajit", "" ], [ "Kumar", "Narinder", "" ], [ "Dahiya", "Harleen", "" ] ]
In this work, we have established the relations between the T-even proton transverse momentum-dependent parton distributions (TMDs) at all twist levels up to twist-4 using the light-front quark diquark model (LFQDM). From the parameterization equations of TMDs, we have found that there are multiple ways by which a particular TMD can be expressed in terms of the helicities of the proton in the initial and final states. For the first time, we have presented a parameterization table that can be applied to the derivation and recognition of proton TMDs based on their helicity. We have constructed the linear and quadratic relationships of TMDs at the intra-twist and inter-twist levels within the same model. We have also looked at the inequality relations that TMDs follow. Additionally, to provide an easy access to the calculations, amplitude matrices have been expressed in the form of TMDs over all the possible helicities of the diquark.
1301.0464
Paul Frampton
Paul H. Frampton
Higgs Couplings to $t$, $b$, and $\tau$ with Flavor Symmetry
6 pages LaTex
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Experimental study at LHC of the possible Higgs boson should soon provide accurate estimates of the Yukawa couplings $Y_{H\bar{f}f}$ for $f=t,b,\tau$. In the presence of a non-abelian discrete flavor symmetry $G_F$ (e.g. T') the usual prediction that $Y_{H\bar{f}f} \propto m_f$ should be inexact, and departures therefrom will provide through $G_F$ valuable input to an improved derivation of the quark and lepton mixing matrices.
[ { "created": "Thu, 3 Jan 2013 14:27:45 GMT", "version": "v1" } ]
2013-01-04
[ [ "Frampton", "Paul H.", "" ] ]
Experimental study at LHC of the possible Higgs boson should soon provide accurate estimates of the Yukawa couplings $Y_{H\bar{f}f}$ for $f=t,b,\tau$. In the presence of a non-abelian discrete flavor symmetry $G_F$ (e.g. T') the usual prediction that $Y_{H\bar{f}f} \propto m_f$ should be inexact, and departures therefrom will provide through $G_F$ valuable input to an improved derivation of the quark and lepton mixing matrices.
1101.3035
Ho-Meoyng Choi
Ho-Meoyng Choi (Kyungpook National Univ.) and Chueng-Ryong Ji (North Carolina State Univ.)
Light-front zero-mode contribution to the tensor form factors for the exclusive rare $P\to V\ell^+\ell^-$ decays
13 pages, 2 figures, to appear in Phys. Lett. B
Phys. Lett. B696:518-522, 2011
10.1016/j.physletb.2011.01.021
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the light-front zero-mode contribution to the tensor form factors $T_i(i=1,2,3)$ for the exclusive rare $P\to V\ell^+\ell^-$ decays using a covariant fermion field theory model in $(3+1)$ dimensions. While the zero-mode contribution in principle depends on the form of the vector meson vertex $\Gamma^\mu=\gamma^\mu - (2k-P_V)^\mu/D$, the three tensor form factors $T_i(i=1,2,3)$ are found to be free from the zero mode if the denominator $D$ contains the term proportional to the light-front energy or the longitudinal momentum fraction factor $(1/x)^n$ of the struck quark with the power $n>0$. Since the denominator $D$ used in the light-front quark model (LFQM) has the power $n=1/2$, the three tensor form factors $T_i(i=1,2,3)$ can be computed in LFQM safely without involving any complicate zero-mode contribution. The lack of zero-mode contribution benefits the phenomenology with LFQM.
[ { "created": "Sun, 16 Jan 2011 01:03:03 GMT", "version": "v1" }, { "created": "Thu, 20 Jan 2011 21:34:28 GMT", "version": "v2" } ]
2011-02-16
[ [ "Choi", "Ho-Meoyng", "", "Kyungpook National Univ." ], [ "Ji", "Chueng-Ryong", "", "North\n Carolina State Univ." ] ]
We study the light-front zero-mode contribution to the tensor form factors $T_i(i=1,2,3)$ for the exclusive rare $P\to V\ell^+\ell^-$ decays using a covariant fermion field theory model in $(3+1)$ dimensions. While the zero-mode contribution in principle depends on the form of the vector meson vertex $\Gamma^\mu=\gamma^\mu - (2k-P_V)^\mu/D$, the three tensor form factors $T_i(i=1,2,3)$ are found to be free from the zero mode if the denominator $D$ contains the term proportional to the light-front energy or the longitudinal momentum fraction factor $(1/x)^n$ of the struck quark with the power $n>0$. Since the denominator $D$ used in the light-front quark model (LFQM) has the power $n=1/2$, the three tensor form factors $T_i(i=1,2,3)$ can be computed in LFQM safely without involving any complicate zero-mode contribution. The lack of zero-mode contribution benefits the phenomenology with LFQM.
hep-ph/9206241
null
Adam F. Falk and Michael Luke
Strong Decays of Excited Heavy Mesons In Chiral Perturbation Theory
(14 pages, 2 figures available from the authors, harvmac.tex required), SLAC-PUB-5812, UCSD/PTH 92-14
Phys.Lett.B292:119-127,1992
10.1016/0370-2693(92)90618-E
null
hep-ph
null
We construct an effective Lagrangian describing the interaction of soft pions and kaons with mesons containing a heavy quark and light degrees of freedom in an orbital $p$ wave. The formalism is easily extended to heavy mesons and baryons in arbitrary excited states. We calculate the leading contributions to the strong decays $\dtwo\to\d\pi$, $\dtwo\to\dstar\pi$ and $\done\to\dstar\pi$. We confirm the relations between the rates previously obtained by Isgur and Wise using heavy quark symmetry, and find that the absolute widths are consistent with na\"\i ve power counting. We also estimate the branching ratios for the two pion decays $\dtwo\to\dstar\pi\pi$, $\done\to\dstar\pi\pi$ and $\done\to\d\pi\pi$, which are dominated by pole graphs. Our predictions depend on the masses and widths of the as yet unseen scalar-pseudovector $p$-wave doublet. Heavy quark spin symmetry predicts $\Gamma(\dtwo\to\dstar\pi\pi): \Gamma(\done\to\dstar\pi\pi):\Gamma(\done\to\d\pi\pi)=3:1:2$, but this relation is badly violated in practice because $1/M$ effects arising purely from kinematics are large.
[ { "created": "Mon, 22 Jun 1992 18:46:00 GMT", "version": "v1" } ]
2010-11-01
[ [ "Falk", "Adam F.", "" ], [ "Luke", "Michael", "" ] ]
We construct an effective Lagrangian describing the interaction of soft pions and kaons with mesons containing a heavy quark and light degrees of freedom in an orbital $p$ wave. The formalism is easily extended to heavy mesons and baryons in arbitrary excited states. We calculate the leading contributions to the strong decays $\dtwo\to\d\pi$, $\dtwo\to\dstar\pi$ and $\done\to\dstar\pi$. We confirm the relations between the rates previously obtained by Isgur and Wise using heavy quark symmetry, and find that the absolute widths are consistent with na\"\i ve power counting. We also estimate the branching ratios for the two pion decays $\dtwo\to\dstar\pi\pi$, $\done\to\dstar\pi\pi$ and $\done\to\d\pi\pi$, which are dominated by pole graphs. Our predictions depend on the masses and widths of the as yet unseen scalar-pseudovector $p$-wave doublet. Heavy quark spin symmetry predicts $\Gamma(\dtwo\to\dstar\pi\pi): \Gamma(\done\to\dstar\pi\pi):\Gamma(\done\to\d\pi\pi)=3:1:2$, but this relation is badly violated in practice because $1/M$ effects arising purely from kinematics are large.
1212.3951
Narendra Sahu
Narendra Sahu
Unifying Asymmetric Inert Fermion Doublet Dark Matter and Leptogenesis with Neutrino Mass
5 pages, 3 eps figures, talk given at Recontres du Vietnam,July 15-21, "Beyond the SM of Particle Physics", Quinon, Vietnam
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a scalar Triplet extension of the standard model (SM) to unify the origin of neutrino mass with the visible and dark matter component of the Universe. We assume that the scalar triplet is super heavy, so that its CP-violating out-of-equilibrium decay in the early Universe not only produce asymmetric dark matter which is the neutral component of an additional vector like fermion doublet, but also give rise to lepton asymmetry. The latter gets converted to observed baryon asymmetry via B+L violating sphaleron processes. Below electroweak phase transition the scalar triplet acquires a vacuum expectation value and give rise to sub-eV Majorana masses to three flavors of active neutrinos. Thus an unification of the origin of neutrino mass, lepton asymmetry and asymmetric dark matter is achieved within a scalar triplet extension of the SM.
[ { "created": "Mon, 17 Dec 2012 10:21:32 GMT", "version": "v1" } ]
2012-12-18
[ [ "Sahu", "Narendra", "" ] ]
We propose a scalar Triplet extension of the standard model (SM) to unify the origin of neutrino mass with the visible and dark matter component of the Universe. We assume that the scalar triplet is super heavy, so that its CP-violating out-of-equilibrium decay in the early Universe not only produce asymmetric dark matter which is the neutral component of an additional vector like fermion doublet, but also give rise to lepton asymmetry. The latter gets converted to observed baryon asymmetry via B+L violating sphaleron processes. Below electroweak phase transition the scalar triplet acquires a vacuum expectation value and give rise to sub-eV Majorana masses to three flavors of active neutrinos. Thus an unification of the origin of neutrino mass, lepton asymmetry and asymmetric dark matter is achieved within a scalar triplet extension of the SM.
1908.11710
Aiichi Iwazaki
Aiichi Iwazaki
Chiral Nonsymmetric Interaction in Strong Coupled QCD
10 pages, no figures. arXiv admin note: text overlap with arXiv:1809.00279
null
null
Nisho-3-2019
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Chiral symmetry in massless QCD is believed to be broken spontaneously. We discuss a possibility that the chiral symmetry is explicitly broken by QCD monopoles which appear only in strong coupled QCD. Namely, the monopole quark interaction explicitly breaks the chiral symmetry ( SU$_A(2)\times $U$_A$(1) ) just like bare quark mass terms. We show that the strength of the interaction is roughly $10$ times smaller than standard strong interactions. We describe it as an effective interaction $g'\bar{q}q\Phi^{\dagger}\Phi$ with the monopole field $\Phi$ and $g'$ being of the order of $(10\rm \,GeV)^{-1}$ or less. It produces small constituent quark masses less than $1$MeV when the monopoles condense ( $\langle\Phi\rangle\neq 0 $ ). We examine to what extent such a weak but explicit symmetry breaking interaction is allowed. In particular, examining Gell-Mann-Oakes-Renner relation we find that the presence of such a small symmetry breaking term is still allowed within the present accuracy of lattice gauge simulations. We predict some phenomenological effects caused by the chiral nonsymmetric monopole quark interaction. Quark confinement and chiral condensate ( $\langle\bar{q}q\rangle\neq 0$ ) arise simultaneously. The condensate $\langle\bar{q}q\rangle$ caused by the monopoles is proportional to monopole density and is estimated such that $(-\langle\bar{q}q\rangle)^{1/3}\sim 160$MeV. The weak monopole quark interaction leads to the small decay width of an observable monopole to hadrons.
[ { "created": "Thu, 29 Aug 2019 01:23:35 GMT", "version": "v1" } ]
2019-09-02
[ [ "Iwazaki", "Aiichi", "" ] ]
Chiral symmetry in massless QCD is believed to be broken spontaneously. We discuss a possibility that the chiral symmetry is explicitly broken by QCD monopoles which appear only in strong coupled QCD. Namely, the monopole quark interaction explicitly breaks the chiral symmetry ( SU$_A(2)\times $U$_A$(1) ) just like bare quark mass terms. We show that the strength of the interaction is roughly $10$ times smaller than standard strong interactions. We describe it as an effective interaction $g'\bar{q}q\Phi^{\dagger}\Phi$ with the monopole field $\Phi$ and $g'$ being of the order of $(10\rm \,GeV)^{-1}$ or less. It produces small constituent quark masses less than $1$MeV when the monopoles condense ( $\langle\Phi\rangle\neq 0 $ ). We examine to what extent such a weak but explicit symmetry breaking interaction is allowed. In particular, examining Gell-Mann-Oakes-Renner relation we find that the presence of such a small symmetry breaking term is still allowed within the present accuracy of lattice gauge simulations. We predict some phenomenological effects caused by the chiral nonsymmetric monopole quark interaction. Quark confinement and chiral condensate ( $\langle\bar{q}q\rangle\neq 0$ ) arise simultaneously. The condensate $\langle\bar{q}q\rangle$ caused by the monopoles is proportional to monopole density and is estimated such that $(-\langle\bar{q}q\rangle)^{1/3}\sim 160$MeV. The weak monopole quark interaction leads to the small decay width of an observable monopole to hadrons.
hep-ph/9501244
null
Stephen P. Martin (Randall Physics Laboratory, University of Michigan) and Pierre Ramond (Inst for Fundamental Theory, U Florida, Gainesville)
Raising the unification scale in supersymmetry
22 pages, macros included. One figure, available at ftp://ftp.phys.ufl.edu/incoming/rais.eps
Phys.Rev. D51 (1995) 6515-6523
10.1103/PhysRevD.51.6515
UM-TH-95-01, and UFIFT-HEP-95-1.
hep-ph
null
In the minimal supersymmetric standard model, the three gauge couplings appear to unify at a mass scale near $2 \times 10^{16}$ GeV. We investigate the possibility that intermediate scale particle thresholds modify the running couplings so as to increase the unification scale. By requiring consistency of this scenario, we derive some constraints on the particle content and locations of the intermediate thresholds. There are remarkably few acceptable solutions with a single cleanly defined intermediate scale far below the unification scale.
[ { "created": "Mon, 9 Jan 1995 16:47:52 GMT", "version": "v1" } ]
2016-09-01
[ [ "Martin", "Stephen P.", "", "Randall Physics Laboratory, University of Michigan" ], [ "Ramond", "Pierre", "", "Inst for Fundamental Theory, U Florida, Gainesville" ] ]
In the minimal supersymmetric standard model, the three gauge couplings appear to unify at a mass scale near $2 \times 10^{16}$ GeV. We investigate the possibility that intermediate scale particle thresholds modify the running couplings so as to increase the unification scale. By requiring consistency of this scenario, we derive some constraints on the particle content and locations of the intermediate thresholds. There are remarkably few acceptable solutions with a single cleanly defined intermediate scale far below the unification scale.
1001.4467
Stefan Dittmaier
Ansgar Denner, Stefan Dittmaier, Thomas Gehrmann, Christian Kurz
Electroweak corrections to hadronic event shapes
6 pages, latex, 4 eps figures, contribution to the proceedings of the 9th International Symposium on Radiative Corrections (RADCOR 2009), October 25-30 2009, Ascona, Switzerland
null
null
FR-PHENO-2010-10, PSI-PR-10-06, ZU-TH 01/10
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We report on a recent calculation of the electroweak O(\alpha^3\alpha_s) corrections to 3-jet production and related event-shape observables at e+e- colliders. The calculation properly accounts for the experimental photon isolation criteria and for the corrections to the total hadronic cross section. Corrections to the normalised event-shape distributions, which are exemplarily discussed here for the thrust distribution at LEP and linear-collider energies, turn out to be at the few-per-cent level and show remnants of the radiative return to the Z pole even after inclusion of appropriate cuts.
[ { "created": "Mon, 25 Jan 2010 15:59:50 GMT", "version": "v1" } ]
2010-01-26
[ [ "Denner", "Ansgar", "" ], [ "Dittmaier", "Stefan", "" ], [ "Gehrmann", "Thomas", "" ], [ "Kurz", "Christian", "" ] ]
We report on a recent calculation of the electroweak O(\alpha^3\alpha_s) corrections to 3-jet production and related event-shape observables at e+e- colliders. The calculation properly accounts for the experimental photon isolation criteria and for the corrections to the total hadronic cross section. Corrections to the normalised event-shape distributions, which are exemplarily discussed here for the thrust distribution at LEP and linear-collider energies, turn out to be at the few-per-cent level and show remnants of the radiative return to the Z pole even after inclusion of appropriate cuts.
0804.4225
Pedro Bicudo
P. Bicudo, M. Cardoso, P. Santos, J. Seixas
The Charmonium (Bottomonium) binding ate finite T
6 pages, 4 figures, 7 tables, talk presented at the XLVI International Winter Meeting on Nuclear Physics, Bormio, January 2008
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The charmonium (bottomonim) binding at finite temperature is studied with static potentials extracted from the lattice QCD data of Kaczmarek et al. The bottomonium spectrum is also studied. This is relevant for Hard Probes in Heavy Ion Collisions.
[ { "created": "Sat, 26 Apr 2008 13:10:41 GMT", "version": "v1" } ]
2008-04-29
[ [ "Bicudo", "P.", "" ], [ "Cardoso", "M.", "" ], [ "Santos", "P.", "" ], [ "Seixas", "J.", "" ] ]
The charmonium (bottomonim) binding at finite temperature is studied with static potentials extracted from the lattice QCD data of Kaczmarek et al. The bottomonium spectrum is also studied. This is relevant for Hard Probes in Heavy Ion Collisions.
hep-ph/9705308
null
Philip Baringer (University of Kansas), Pankaj Jain (I.I.T. Kanpur), Douglas W. Mckay and Lesley L. Smith (University of Kansas)
Single Top from Technipion Production
9 pages, latex, uses revtex.sty
Phys. Rev. D 56, 2914 (1997)
10.1103/PhysRevD.56.2914
KUHEP-97010
hep-ph
null
We investigate the contribution of technicolor mechanisms to the production of single top quarks at hadron colliders. Technipions with mass larger than the top mass will decay predominantly to a top quark plus a bottom antiquark. We investigate two promising sub-processes: technipion plus W-boson via gluon-gluon fusion and technipion plus quark production via quark gluon interaction. The decay chain of technipion to top plus bottom quarks and then top to W plus bottom yields final states for the two subprocesses with, respectively, two W's and two bottom quarks and one W, two bottom quarks and a light quark. We calculate the total cross sections and the $p_{T}$ distributions for these technipion production mechanisms at Tevatron and LHC energies for a range of technipion masses, starting at 200 GeV. We study the backgrounds to our processes and the kinematic cuts that enhance the signal to background ratio and we report event rate estimates for the upgraded Tevatron and the LHC. Only the LHC has the potential to observe these processes.
[ { "created": "Tue, 13 May 1997 23:59:00 GMT", "version": "v1" } ]
2016-08-24
[ [ "Baringer", "Philip", "", "University of Kansas" ], [ "Jain", "Pankaj", "", "I.I.T. Kanpur" ], [ "Mckay", "Douglas W.", "", "University of Kansas" ], [ "Smith", "Lesley L.", "", "University of Kansas" ] ]
We investigate the contribution of technicolor mechanisms to the production of single top quarks at hadron colliders. Technipions with mass larger than the top mass will decay predominantly to a top quark plus a bottom antiquark. We investigate two promising sub-processes: technipion plus W-boson via gluon-gluon fusion and technipion plus quark production via quark gluon interaction. The decay chain of technipion to top plus bottom quarks and then top to W plus bottom yields final states for the two subprocesses with, respectively, two W's and two bottom quarks and one W, two bottom quarks and a light quark. We calculate the total cross sections and the $p_{T}$ distributions for these technipion production mechanisms at Tevatron and LHC energies for a range of technipion masses, starting at 200 GeV. We study the backgrounds to our processes and the kinematic cuts that enhance the signal to background ratio and we report event rate estimates for the upgraded Tevatron and the LHC. Only the LHC has the potential to observe these processes.
1304.5293
Shigehiro Yasui
S. Yasui, K. Sudoh, Y. Yamaguchi, S. Ohkoda, A. Hosaka and T. Hyodo
Spin degeneracy in multi-hadron systems with a heavy quark
9 pages, 1 figure
Phys. Lett. B727 (2013) 185
10.1016/j.physletb.2013.10.019
KEK-TH-1621, J-PARC-TH-0025
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study multi-hadron systems with a single heavy quark (charm or bottom) in the limit of heavy quark mass. The spin degeneracy of the states with quantum numbers $(j+1/2)^{P}$ and $(j-1/2)^{P}$ for $j \neq 0$, known in a normal hadron, can be generalized to multi-hadron systems. The spin degeneracy is the universal phenomena for any multi-hadron systems with a single heavy quark, irrespective of their internal structures, including compact multi-quarks, hadronic molecules and exotic nuclei. We demonstrate the spin degeneracy in the hadronic systems formed by a heavy hadron effective theory; $P^{(\ast)}N$ states with a $P^{(\ast)}=\bar{D}^{(\ast)}$, $B^{(\ast)}$ meson and a nucleon $N$, and a $P^{(\ast)}$ meson in nuclear matter.
[ { "created": "Fri, 19 Apr 2013 01:21:14 GMT", "version": "v1" }, { "created": "Tue, 17 Sep 2013 03:23:42 GMT", "version": "v2" } ]
2019-08-07
[ [ "Yasui", "S.", "" ], [ "Sudoh", "K.", "" ], [ "Yamaguchi", "Y.", "" ], [ "Ohkoda", "S.", "" ], [ "Hosaka", "A.", "" ], [ "Hyodo", "T.", "" ] ]
We study multi-hadron systems with a single heavy quark (charm or bottom) in the limit of heavy quark mass. The spin degeneracy of the states with quantum numbers $(j+1/2)^{P}$ and $(j-1/2)^{P}$ for $j \neq 0$, known in a normal hadron, can be generalized to multi-hadron systems. The spin degeneracy is the universal phenomena for any multi-hadron systems with a single heavy quark, irrespective of their internal structures, including compact multi-quarks, hadronic molecules and exotic nuclei. We demonstrate the spin degeneracy in the hadronic systems formed by a heavy hadron effective theory; $P^{(\ast)}N$ states with a $P^{(\ast)}=\bar{D}^{(\ast)}$, $B^{(\ast)}$ meson and a nucleon $N$, and a $P^{(\ast)}$ meson in nuclear matter.
hep-ph/0501073
Tadayuki Teshima
T. Teshima, I. Kitamura and N. Morisita
Radiative Decays Involving $f_0(980)$ and $a_0(980)$ and Mixing Between Low and High Mass Scalar Mesons
15 pages, 6 figures
Nucl.Phys.A759:131-142,2005
10.1016/j.nuclphysa.2005.04.024
CU-TP/05-01
hep-ph
null
We analyze the experimental data for $\phi\to f_0(980)\gamma$, $\phi\to a_0(980)\gamma$, $f_0(980)\to\gamma\gamma$ and $a_0(980)\to\gamma\gamma$ decay widths in a framework where $f_0(980)$ and $a_0(980)$ are assumed to be mainly $qq\bar{q}\bar{q}$ low mass scalar mesons and mixed with $q\bar{q}$ high mass scalar mesons. Applied the vector meson dominance model (VDM), these decays amplitudes are expressed by coupling parameters $B$ describing the S ($qq\bar{q}\bar{q}$ scalar meson)-V(vector meson)- V(vector meson) coupling and $B'$ describing the S' ($q\bar{q}$ scalar meson)-V-V coupling. Adopting the magnitudes for $B$ and $B'$ as $2.8{GeV^{-1}}$ and $12{GeV^{-1}}$, respectively, the mixing angle between $a_0(980)$ and $a_0(1450)$ as 9 degrees, and the mixing parameter $\lambda_{01}$ causing the mixing between I=0 $qq\bar{q}\bar{q}$ state and $q\bar{q}$ state as $0.24{GeV}^2$, we can interpret these experimental data, consistently.
[ { "created": "Mon, 10 Jan 2005 16:19:30 GMT", "version": "v1" } ]
2008-11-26
[ [ "Teshima", "T.", "" ], [ "Kitamura", "I.", "" ], [ "Morisita", "N.", "" ] ]
We analyze the experimental data for $\phi\to f_0(980)\gamma$, $\phi\to a_0(980)\gamma$, $f_0(980)\to\gamma\gamma$ and $a_0(980)\to\gamma\gamma$ decay widths in a framework where $f_0(980)$ and $a_0(980)$ are assumed to be mainly $qq\bar{q}\bar{q}$ low mass scalar mesons and mixed with $q\bar{q}$ high mass scalar mesons. Applied the vector meson dominance model (VDM), these decays amplitudes are expressed by coupling parameters $B$ describing the S ($qq\bar{q}\bar{q}$ scalar meson)-V(vector meson)- V(vector meson) coupling and $B'$ describing the S' ($q\bar{q}$ scalar meson)-V-V coupling. Adopting the magnitudes for $B$ and $B'$ as $2.8{GeV^{-1}}$ and $12{GeV^{-1}}$, respectively, the mixing angle between $a_0(980)$ and $a_0(1450)$ as 9 degrees, and the mixing parameter $\lambda_{01}$ causing the mixing between I=0 $qq\bar{q}\bar{q}$ state and $q\bar{q}$ state as $0.24{GeV}^2$, we can interpret these experimental data, consistently.
0709.3918
Kazunori Nakayama
Minoru Nagai, Kazunori Nakayama
Nonthermal dark matter in mirage mediation
8 pages, 7 figures; version to appear in PRD
Phys.Rev.D76:123501,2007
10.1103/PhysRevD.76.123501
null
hep-ph
null
In mirage-mediation models there exists a modulus field whose mass is O(1000) TeV and its late-decay may significantly change the standard thermal relic scenario of the dark matter. We study nonthermal production of the dark matter directly from the modulus decay, and find that for some parameter regions non-thermally produced neutralinos can become the dark matter.
[ { "created": "Tue, 25 Sep 2007 10:54:17 GMT", "version": "v1" }, { "created": "Wed, 24 Oct 2007 04:24:24 GMT", "version": "v2" } ]
2008-11-26
[ [ "Nagai", "Minoru", "" ], [ "Nakayama", "Kazunori", "" ] ]
In mirage-mediation models there exists a modulus field whose mass is O(1000) TeV and its late-decay may significantly change the standard thermal relic scenario of the dark matter. We study nonthermal production of the dark matter directly from the modulus decay, and find that for some parameter regions non-thermally produced neutralinos can become the dark matter.
1903.01993
Felix Ringer
Jian-Wei Qiu, Felix Ringer, Nobuo Sato, Pia Zurita
Factorization of jet cross sections in heavy-ion collisions
6 pages, 4 figures
Phys. Rev. Lett. 122, 252301 (2019)
10.1103/PhysRevLett.122.252301
JLAB-THY-19-2896
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a new phenomenological approach to establish QCD factorization of jet cross sections in the heavy-ion environment. Starting from a factorization formalism in proton-proton collisions, we introduce medium modified jet functions to capture the leading interaction of jets with the hot and dense QCD medium. A global analysis using a Monte Carlo sampling approach is performed in order to reliably determine the new jet functions from the nuclear modification factor of inclusive jets at the LHC. We find that gluon jets are significantly more suppressed due to the presence of the medium than quark jets. In addition, we observe that the jet radius dependence is directly related to the relative suppression of quark and gluon jets. Our approach may help to improve the extraction of medium properties from data.
[ { "created": "Tue, 5 Mar 2019 19:00:00 GMT", "version": "v1" } ]
2019-07-03
[ [ "Qiu", "Jian-Wei", "" ], [ "Ringer", "Felix", "" ], [ "Sato", "Nobuo", "" ], [ "Zurita", "Pia", "" ] ]
We propose a new phenomenological approach to establish QCD factorization of jet cross sections in the heavy-ion environment. Starting from a factorization formalism in proton-proton collisions, we introduce medium modified jet functions to capture the leading interaction of jets with the hot and dense QCD medium. A global analysis using a Monte Carlo sampling approach is performed in order to reliably determine the new jet functions from the nuclear modification factor of inclusive jets at the LHC. We find that gluon jets are significantly more suppressed due to the presence of the medium than quark jets. In addition, we observe that the jet radius dependence is directly related to the relative suppression of quark and gluon jets. Our approach may help to improve the extraction of medium properties from data.
hep-ph/0312142
Nora Brambilla
Nora Brambilla (Milano)
Potential models, sum rules, color singlet model versus NREFT in Heavy Quarkonium
Talk at the International Workshop on QCD: QCD@Work 2003- Conversano (Italy) 14-18 June 2003 (eConf C030614), 6 pages, uses wQCD03.cls
null
null
IFUM-780-FT
hep-ph
null
I briefly review how nonrelativistic effective field theories solve old puzzles and open problems in heavy quarkonium physics.
[ { "created": "Wed, 10 Dec 2003 17:36:06 GMT", "version": "v1" } ]
2007-05-23
[ [ "Brambilla", "Nora", "", "Milano" ] ]
I briefly review how nonrelativistic effective field theories solve old puzzles and open problems in heavy quarkonium physics.
2207.10332
K{\i}van\c{c} Yi\u{g}it \c{C}{\i}ng{\i}lo\u{g}lu
Ash Arsenault, Kivanc Y. Cingiloglu, Mariana Frank
Vacuum stability in the Standard Model with vector-like fermions
27 pages, 12 figures
null
10.1103/PhysRevD.107.036018
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The discovery of Standard-Model like Higgs at 125 GeV may raise more questions than the answers it provides. In particular, the hierarchy problem remains unsolved, and the Standard Model Higgs quartic self-coupling becomes negative below the Planck scale, necessitating new physics beyond the Standard Model. In this work we investigate a popular scenario, extensions of the Standard Model with vector-like fermion fields, such as the ones present in models with extra dimensions or in Higgs composite models, using a model independent approach. Since fermions decrease the Higgs quartic coupling at high energies, only exacerbating the self-coupling problem, we introduce first an additional scalar, which by itself is enough to overcome the vacuum stability limit, and then explore the effects of vector-like fermions in singlet, doublet and triplet representations. For each model, we identify the allowed fermion masses and mixing angles with the third family fermions required to satisfy the vacuum stability condition, and compare different representations. Allowed fermion masses emerge at around 1 TeV, raising hope that these will be found at the LHC. We also examine corrections to oblique parameters S and T from additional scalar and vector-like quarks which also impose constraints on mixing and mass splitting of both sectors., but these restrictions are relatively weak compared to the vacuum stability.
[ { "created": "Thu, 21 Jul 2022 06:58:26 GMT", "version": "v1" } ]
2023-03-08
[ [ "Arsenault", "Ash", "" ], [ "Cingiloglu", "Kivanc Y.", "" ], [ "Frank", "Mariana", "" ] ]
The discovery of Standard-Model like Higgs at 125 GeV may raise more questions than the answers it provides. In particular, the hierarchy problem remains unsolved, and the Standard Model Higgs quartic self-coupling becomes negative below the Planck scale, necessitating new physics beyond the Standard Model. In this work we investigate a popular scenario, extensions of the Standard Model with vector-like fermion fields, such as the ones present in models with extra dimensions or in Higgs composite models, using a model independent approach. Since fermions decrease the Higgs quartic coupling at high energies, only exacerbating the self-coupling problem, we introduce first an additional scalar, which by itself is enough to overcome the vacuum stability limit, and then explore the effects of vector-like fermions in singlet, doublet and triplet representations. For each model, we identify the allowed fermion masses and mixing angles with the third family fermions required to satisfy the vacuum stability condition, and compare different representations. Allowed fermion masses emerge at around 1 TeV, raising hope that these will be found at the LHC. We also examine corrections to oblique parameters S and T from additional scalar and vector-like quarks which also impose constraints on mixing and mass splitting of both sectors., but these restrictions are relatively weak compared to the vacuum stability.
hep-ph/0501169
Pedro Jimenez Delgado
M. Gl\"uck, P. Jimenez-Delgado, E. Reya
Radiatively Generated Isospin Violations in the Nucleon
9 pages, 3 figures
null
null
DO-TH 2005/01
hep-ph
null
Isospin violating valence and sea distributions are evaluated due to QED leading ${\cal{O}}{(\alpha)}$ corrections to the standard QCD evolution equations. Unique perturbative predictions are obtained within the radiative parton model, and confirm earlier results. Nonperturbative contributions have been estimated and depend on a single free parameter chosen to be the current quark mass.The relevance of our predictions for extracting $\sin^2 \theta_W$ from DIS $\nu(\bar{\nu})N$ data (`NuTeV anomaly') is discussed as well.
[ { "created": "Tue, 18 Jan 2005 17:42:10 GMT", "version": "v1" }, { "created": "Thu, 17 Feb 2005 14:53:31 GMT", "version": "v2" } ]
2007-05-23
[ [ "Glück", "M.", "" ], [ "Jimenez-Delgado", "P.", "" ], [ "Reya", "E.", "" ] ]
Isospin violating valence and sea distributions are evaluated due to QED leading ${\cal{O}}{(\alpha)}$ corrections to the standard QCD evolution equations. Unique perturbative predictions are obtained within the radiative parton model, and confirm earlier results. Nonperturbative contributions have been estimated and depend on a single free parameter chosen to be the current quark mass.The relevance of our predictions for extracting $\sin^2 \theta_W$ from DIS $\nu(\bar{\nu})N$ data (`NuTeV anomaly') is discussed as well.
2403.18214
Bikai Gao
Bikai Gao and Toru Kojo and Masayasu Harada
Parity doublet model for baryon octets: ground states saturated by good diquarks and the role of bad diquarks for excited states
null
null
null
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
Parity doublet model is an effective chiral model that includes the chiral variant and invariant masses of baryons. The chiral invariant mass has large impacts on the density dependence of models which can be constrained by neutron star observations. In the previous work, models of two-flavors have been considered up to a few times nuclear saturation density, but in such dense region it is also necessary to consider hyperons. With the chiral invariant masses baryons can stay massive in extreme environments (e.g., neutron stars) where the chiral symmetry restoration takes place. In this work, we generalize the previous $\mbox{SU(2)}_L \times \mbox{SU(2)}_R$ parity models of nucleons to $\mbox{SU(3)}_L \times \mbox{SU(3)}_R$ models of the baryon octet, within the linear realization of the chiral symmetry. The major problem in constructing such models has been too many candidates for the chiral representations of baryons. Motivated by the concepts of diquarks and the mended symmetry, we choose the $(3_L, \bar{3}_R) + (\bar{3}_L, 3_R)$, $(3_L, 6_R) + (6_L, 3_R)$ and $(1_L, 8_R) + (8_L, 1_R)$ representations and use quark diagrams to constrain the possible types of Yukawa interactions. The masses of the baryon octets for positive and negative baryons up to the first excitations are successfully reproduced. As expected from the diquark considerations, the ground state baryons are well dominated by $(3_L, \bar{3}_R) + (\bar{3}_L, 3_R)$ and $(1_L, 8_R) + (8_L, 1_R)$ representations, while the excited states require $(3_L, 6_R) + (6_L, 3_R)$ representations. Important applications of our model are the chiral restoration for strange quarks at large density and the continuity of diquarks from hadronic to quark matter. We also address the problem of large Yukawa couplings which are enhanced in three-flavor construction.
[ { "created": "Wed, 27 Mar 2024 02:52:16 GMT", "version": "v1" } ]
2024-03-28
[ [ "Gao", "Bikai", "" ], [ "Kojo", "Toru", "" ], [ "Harada", "Masayasu", "" ] ]
Parity doublet model is an effective chiral model that includes the chiral variant and invariant masses of baryons. The chiral invariant mass has large impacts on the density dependence of models which can be constrained by neutron star observations. In the previous work, models of two-flavors have been considered up to a few times nuclear saturation density, but in such dense region it is also necessary to consider hyperons. With the chiral invariant masses baryons can stay massive in extreme environments (e.g., neutron stars) where the chiral symmetry restoration takes place. In this work, we generalize the previous $\mbox{SU(2)}_L \times \mbox{SU(2)}_R$ parity models of nucleons to $\mbox{SU(3)}_L \times \mbox{SU(3)}_R$ models of the baryon octet, within the linear realization of the chiral symmetry. The major problem in constructing such models has been too many candidates for the chiral representations of baryons. Motivated by the concepts of diquarks and the mended symmetry, we choose the $(3_L, \bar{3}_R) + (\bar{3}_L, 3_R)$, $(3_L, 6_R) + (6_L, 3_R)$ and $(1_L, 8_R) + (8_L, 1_R)$ representations and use quark diagrams to constrain the possible types of Yukawa interactions. The masses of the baryon octets for positive and negative baryons up to the first excitations are successfully reproduced. As expected from the diquark considerations, the ground state baryons are well dominated by $(3_L, \bar{3}_R) + (\bar{3}_L, 3_R)$ and $(1_L, 8_R) + (8_L, 1_R)$ representations, while the excited states require $(3_L, 6_R) + (6_L, 3_R)$ representations. Important applications of our model are the chiral restoration for strange quarks at large density and the continuity of diquarks from hadronic to quark matter. We also address the problem of large Yukawa couplings which are enhanced in three-flavor construction.
1612.04382
Zijie Poh
B. Charles Bryant, Zijie Poh and Stuart Raby
Reheating and Leptogenesis after Pati-Salam F-term Subcritical Hybrid Inflation
44 pages, 7 figures, 2 tables
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we extend the analysis of a Pati-Salam subcritical hybrid $F$-term inflation model, proposed by two of us, by studying the reheating and the baryogenesis (via leptogenesis) of the model. This SUSY GUT model is able to fit low energy electroweak precision data, LHC data, $b$-physics data, in addition to inflation observables such as the tensor-to-scalar ratio and the scalar spectral index. The reheating mechanism of this model is instant preheating due to the bosonic and fermionic broad parametric resonance, while the baryon-to-entropy ratio is obtained from the CP asymmetric right-handed (s)neutrinos decay. The phases in the neutrino Yukawa matrices are fixed by fitting to the low energy observables. With these phases, the heaviest right-handed (s)neutrinos decay to produce a lepton asymmetry with the correct sign, while the two lighter right-handed (s)neutrinos decay to produce the wrong sign. Consequently, the baryogenesis analysis is necessarily performed by including all three families of the right-handed (s)neutrinos.
[ { "created": "Tue, 13 Dec 2016 21:00:05 GMT", "version": "v1" } ]
2016-12-15
[ [ "Bryant", "B. Charles", "" ], [ "Poh", "Zijie", "" ], [ "Raby", "Stuart", "" ] ]
In this paper, we extend the analysis of a Pati-Salam subcritical hybrid $F$-term inflation model, proposed by two of us, by studying the reheating and the baryogenesis (via leptogenesis) of the model. This SUSY GUT model is able to fit low energy electroweak precision data, LHC data, $b$-physics data, in addition to inflation observables such as the tensor-to-scalar ratio and the scalar spectral index. The reheating mechanism of this model is instant preheating due to the bosonic and fermionic broad parametric resonance, while the baryon-to-entropy ratio is obtained from the CP asymmetric right-handed (s)neutrinos decay. The phases in the neutrino Yukawa matrices are fixed by fitting to the low energy observables. With these phases, the heaviest right-handed (s)neutrinos decay to produce a lepton asymmetry with the correct sign, while the two lighter right-handed (s)neutrinos decay to produce the wrong sign. Consequently, the baryogenesis analysis is necessarily performed by including all three families of the right-handed (s)neutrinos.
1512.03640
Satilmis Atag
S. Atag, E. Gurkanli
Prediction for CP Violation via Electric Dipole Moment of $\tau$ Lepton in ${\gamma\gamma \to \tau^{+}\tau^{-}}$ Process at CLIC
16 pages, four figures, two tables
null
10.1007/JHEP06(2016)118
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Pair production of tau leptons in two photon collision ${\gamma\gamma \to \tau^{+}\tau}^{-}$ is studied at CLIC to test CP violating QED couplings of tau leptons. CP violating effects are investigated using tau pair spin correlations which are observed through the hadronic decay of each $\tau$ into $\pi\nu$. Competitive bounds with previous works on the electric dipole moment from CP odd terms have been obtained.
[ { "created": "Fri, 11 Dec 2015 13:54:11 GMT", "version": "v1" }, { "created": "Tue, 1 Mar 2016 12:56:44 GMT", "version": "v2" }, { "created": "Mon, 4 Apr 2016 13:04:59 GMT", "version": "v3" }, { "created": "Sat, 7 May 2016 10:21:02 GMT", "version": "v4" } ]
2016-07-20
[ [ "Atag", "S.", "" ], [ "Gurkanli", "E.", "" ] ]
Pair production of tau leptons in two photon collision ${\gamma\gamma \to \tau^{+}\tau}^{-}$ is studied at CLIC to test CP violating QED couplings of tau leptons. CP violating effects are investigated using tau pair spin correlations which are observed through the hadronic decay of each $\tau$ into $\pi\nu$. Competitive bounds with previous works on the electric dipole moment from CP odd terms have been obtained.
hep-ph/0410378
J. D. Vergados
J.D. Vergados (University of Ioannina, Ioannina, Greece)
Some Issues Related to the Direct Detection of SUSY Dark Matter Detection
11 Latex pages, 8 figures, 2 tables, invited talk presented in idm2000, Edinburgh 6-10/9/2004
null
null
null
hep-ph
null
Since the expected rates for neutralino-nucleus scattering are expected to be small, one should exploit all the characteristic signatures of this reaction. Such are: (i) In the standard recoil measurements the modulation of the event rate due to the Earth's motion. (ii) In directional recoil experiments the correlation of the event rate with the sun's motion. One now has both modulation, which is much larger and depends not only on time, but on the direction of observation as well, and a large forward-backward asymmetry. (iii) In non recoil experiments gamma rays following the decay of excited states populated during the Nucleus-LSP collision. Branching ratios of about 6 percent are possible.
[ { "created": "Thu, 28 Oct 2004 01:23:45 GMT", "version": "v1" }, { "created": "Fri, 29 Oct 2004 15:44:29 GMT", "version": "v2" } ]
2007-05-23
[ [ "Vergados", "J. D.", "", "University of Ioannina, Ioannina, Greece" ] ]
Since the expected rates for neutralino-nucleus scattering are expected to be small, one should exploit all the characteristic signatures of this reaction. Such are: (i) In the standard recoil measurements the modulation of the event rate due to the Earth's motion. (ii) In directional recoil experiments the correlation of the event rate with the sun's motion. One now has both modulation, which is much larger and depends not only on time, but on the direction of observation as well, and a large forward-backward asymmetry. (iii) In non recoil experiments gamma rays following the decay of excited states populated during the Nucleus-LSP collision. Branching ratios of about 6 percent are possible.
2006.15547
Ju-Jun Xie
Chun-Hua Zeng, Jun-Xu Lu, En Wang, Ju-Jun Xie, and Li-Sheng Geng
Theoretical study of the $\Omega(2012)$ state in the $\Omega_c^0 \to \pi^+ \Omega(2012)^- \to \pi^+ (\bar{K}\Xi)^-$ and $\pi^+ (\bar{K}\Xi\pi)^-$ decays
More references and discussions are added; typos are fixed
Phys. Rev. D 102, 076009 (2020)
10.1103/PhysRevD.102.076009
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We report on a theoretical study of the newly observed $\Omega(2012)$ resonance in the nonleptonic weak decays of $\Omega_c^0 \to \pi^+ \bar{K}\Xi^*(1530) (\eta \Omega) \to \pi^+ (\bar{K}\Xi)^-$ and $\pi^+ (\bar{K}\Xi\pi)^-$ via final-state interactions of the $\bar{K}\Xi^*(1530)$ and $\eta \Omega$ pairs. The weak interaction part is assumed to be dominated by the charm quark decay process: $c(ss) \to (s + u + \bar{d})(ss)$, while the hadronization part takes place between the $sss$ cluster from the weak decay and a quark-antiquark pair with the quantum numbers $J^{PC} = 0^{++}$ of the vacuum, produces a pair of $\bar{K}\Xi^*(1530)$ and $\eta \Omega$. Accordingly, the final $\bar{K}\Xi^*(1530)$ and $\eta \Omega$ states are in pure isospin $I= 0$ combinations, and the $\Omega_c^0 \to \pi^+ \bar{K}\Xi^*(1530)(\eta \Omega) \to \pi^+ (\bar{K}\Xi)^-$ decay is an ideal process to study the $\Omega(2012)$ resonance. With the final-state interaction described in the chiral unitary approach, up to an arbitrary normalization, the invariant mass distributions of the final state are calculated, assuming that the $\Omega(2012)$ resonance with spin-parity $J^P = 3/2^-$ is a dynamically generated state from the coupled channels interactions of the $\bar{K}\Xi^*(1530)$ and $\eta \Omega$ in $s$-wave and $\bar{K}\Xi$ in $d$-wave. We also calculate the ratio, $R^{\bar{K}\Xi\pi}_{\bar{K}\Xi} = {\rm Br}[\Omega_c^0 \to \pi^+ \Omega(2012)^- \to \pi^+ (\bar{K}\Xi \pi)^-] / {\rm Br}[\Omega_c^0 \to \pi^+ \Omega(2012)^- \to \pi^+ (\bar{K}\Xi)^-$]. The proposed mechanism can provide valuable information on the nature of the $\Omega(2012)$ and can in principle be tested by future experiments.
[ { "created": "Sun, 28 Jun 2020 09:12:07 GMT", "version": "v1" }, { "created": "Sat, 4 Jul 2020 09:16:31 GMT", "version": "v2" } ]
2020-10-28
[ [ "Zeng", "Chun-Hua", "" ], [ "Lu", "Jun-Xu", "" ], [ "Wang", "En", "" ], [ "Xie", "Ju-Jun", "" ], [ "Geng", "Li-Sheng", "" ] ]
We report on a theoretical study of the newly observed $\Omega(2012)$ resonance in the nonleptonic weak decays of $\Omega_c^0 \to \pi^+ \bar{K}\Xi^*(1530) (\eta \Omega) \to \pi^+ (\bar{K}\Xi)^-$ and $\pi^+ (\bar{K}\Xi\pi)^-$ via final-state interactions of the $\bar{K}\Xi^*(1530)$ and $\eta \Omega$ pairs. The weak interaction part is assumed to be dominated by the charm quark decay process: $c(ss) \to (s + u + \bar{d})(ss)$, while the hadronization part takes place between the $sss$ cluster from the weak decay and a quark-antiquark pair with the quantum numbers $J^{PC} = 0^{++}$ of the vacuum, produces a pair of $\bar{K}\Xi^*(1530)$ and $\eta \Omega$. Accordingly, the final $\bar{K}\Xi^*(1530)$ and $\eta \Omega$ states are in pure isospin $I= 0$ combinations, and the $\Omega_c^0 \to \pi^+ \bar{K}\Xi^*(1530)(\eta \Omega) \to \pi^+ (\bar{K}\Xi)^-$ decay is an ideal process to study the $\Omega(2012)$ resonance. With the final-state interaction described in the chiral unitary approach, up to an arbitrary normalization, the invariant mass distributions of the final state are calculated, assuming that the $\Omega(2012)$ resonance with spin-parity $J^P = 3/2^-$ is a dynamically generated state from the coupled channels interactions of the $\bar{K}\Xi^*(1530)$ and $\eta \Omega$ in $s$-wave and $\bar{K}\Xi$ in $d$-wave. We also calculate the ratio, $R^{\bar{K}\Xi\pi}_{\bar{K}\Xi} = {\rm Br}[\Omega_c^0 \to \pi^+ \Omega(2012)^- \to \pi^+ (\bar{K}\Xi \pi)^-] / {\rm Br}[\Omega_c^0 \to \pi^+ \Omega(2012)^- \to \pi^+ (\bar{K}\Xi)^-$]. The proposed mechanism can provide valuable information on the nature of the $\Omega(2012)$ and can in principle be tested by future experiments.
hep-ph/0107116
M. V. T. Machado
M. B. Gay Ducati (UFRGS)
High Density QCD
41 pages, 13 figures. Plenary Talk presented at XXI ENFPC, Sao Lourenco, Brasil, October, 24th (2000)
Braz.J.Phys.31:115-130,2001
null
null
hep-ph
null
The dynamics of high partonic density QCD is presented considering, in the double logarithm approximation, the parton recombination mechanism built in the AGL formalism, developed including unitarity corrections for the nucleon as well for nucleus. It is shown that these corrections are under theoretical control. The resulting non linear evolution equation is solved in the asymptotic regime, and a comprehensive phenomenology concerning Deep Inelastic Scattering like $F_2$, $F_L$, $F_2^c$. $\partial F_2/ \partial \ln Q^2$, $\partial F^A_2/ \partial \ln Q^2$, etc, is presented. The connection of our formalism with the DGLAP and BFKL dynamics, and with other perturbative (K) and non-perturbative (MV-JKLW) approaches is analised in detail. The phenomena of saturation due to shadowing corrections and the relevance of this effect in ion physics and heavy quark production is emphasized. The implications to e-RHIC, HERA-A, and LHC physics and some open questions are mentioned.
[ { "created": "Tue, 10 Jul 2001 20:08:02 GMT", "version": "v1" } ]
2014-11-17
[ [ "Ducati", "M. B. Gay", "", "UFRGS" ] ]
The dynamics of high partonic density QCD is presented considering, in the double logarithm approximation, the parton recombination mechanism built in the AGL formalism, developed including unitarity corrections for the nucleon as well for nucleus. It is shown that these corrections are under theoretical control. The resulting non linear evolution equation is solved in the asymptotic regime, and a comprehensive phenomenology concerning Deep Inelastic Scattering like $F_2$, $F_L$, $F_2^c$. $\partial F_2/ \partial \ln Q^2$, $\partial F^A_2/ \partial \ln Q^2$, etc, is presented. The connection of our formalism with the DGLAP and BFKL dynamics, and with other perturbative (K) and non-perturbative (MV-JKLW) approaches is analised in detail. The phenomena of saturation due to shadowing corrections and the relevance of this effect in ion physics and heavy quark production is emphasized. The implications to e-RHIC, HERA-A, and LHC physics and some open questions are mentioned.
hep-ph/9503390
Ananda B. Santra
A. N. Kamal, A. B. Santra, T. Uppal and R. C. Verma
Nonfactorization in Hadronic Two-body Cabibbo-favored decays of D^0 and D^+
15 pages, Latex
Phys.Rev. D53 (1996) 2506-2515
10.1103/PhysRevD.53.2506
Alberta Thy-8-95; March,1995
hep-ph
null
With the inclusion of nonfactorized amplitudes in a scheme with $N_c=3$, we have studied Cabibbo-favored decays of $D^0$ and $D^+$ into two-body hadronic states involving two isospins in the final state. We have shown that it is possible to understand the measured branching ratios and determined the sizes and signs of nonfactorized amplitudes required.
[ { "created": "Mon, 20 Mar 1995 22:29:09 GMT", "version": "v1" } ]
2009-10-28
[ [ "Kamal", "A. N.", "" ], [ "Santra", "A. B.", "" ], [ "Uppal", "T.", "" ], [ "Verma", "R. C.", "" ] ]
With the inclusion of nonfactorized amplitudes in a scheme with $N_c=3$, we have studied Cabibbo-favored decays of $D^0$ and $D^+$ into two-body hadronic states involving two isospins in the final state. We have shown that it is possible to understand the measured branching ratios and determined the sizes and signs of nonfactorized amplitudes required.
hep-ph/9902270
Per Osland
P. Osland (Bergen) and P. N. Pandita (Shillong)
Measuring Trilinear Higgs Couplings in the MSSM
12 pages, LaTeX, including figures, uses epsf. Presented at VIIIth UNESCO St. Petersburg International School of Physics, May 25 - June 4, 1998. To be published in the Proceedings
null
null
Bergen Scientific/Technical Report No. 1999-01
hep-ph
null
Trilinear couplings of the neutral CP-even Higgs bosons in the Minimal Supersymmetric Standard Model (MSSM) can be measured through the multiple production of the lightest CP-even Higgs boson (h) at high-energy e^+e^- colliders. This includes the production of the heavier CP-even Higgs boson (H) via e^+e^- \to ZH, in association with the CP-odd Higgs boson (A) in e^+e^- \to AH, or via e^+e^- \to \nu_e \bar\nu_e H, with H subsequently decaying through H \to hh. These processes can enable one to measure the trilinear Higgs couplings \lambda_{Hhh} and \lambda_{hhh}, which can be used to theoretically reconstruct the Higgs potential. We delineate the regions of the MSSM parameter space in which these trilinear Higgs couplings could be measured.
[ { "created": "Mon, 8 Feb 1999 18:04:21 GMT", "version": "v1" } ]
2007-05-23
[ [ "Osland", "P.", "", "Bergen" ], [ "Pandita", "P. N.", "", "Shillong" ] ]
Trilinear couplings of the neutral CP-even Higgs bosons in the Minimal Supersymmetric Standard Model (MSSM) can be measured through the multiple production of the lightest CP-even Higgs boson (h) at high-energy e^+e^- colliders. This includes the production of the heavier CP-even Higgs boson (H) via e^+e^- \to ZH, in association with the CP-odd Higgs boson (A) in e^+e^- \to AH, or via e^+e^- \to \nu_e \bar\nu_e H, with H subsequently decaying through H \to hh. These processes can enable one to measure the trilinear Higgs couplings \lambda_{Hhh} and \lambda_{hhh}, which can be used to theoretically reconstruct the Higgs potential. We delineate the regions of the MSSM parameter space in which these trilinear Higgs couplings could be measured.
hep-ph/9906447
Palash Baran Pal
Palash B. Pal
Determination of cosmological parameters: an introduction for non-specialists
12 pages, Latex with epsf.sty. Invited talk at the ``Discussion meeting on Recent Developments in Neutrino Physics'', held at the Physical Research Laboratory, Ahmedabad, February 2--4, 1999
Pramana 54:79-91,2000
10.1007/s12043-000-0008-2
SINP/TNP/99-22
hep-ph
null
I start by defining the cosmological parameters $H_0, \Omega_m$ and $\Omega_\Lambda$. Then I show how the age of the universe depends on them, followed by the evolution of the scale parameter of the universe for various values of the density parameters. Then I define strategies for measuring them, and show the results for the recent determination of these parameters from measurements on supernovas of type 1a. Implications for particle physics is briefly discussed at the end.
[ { "created": "Tue, 22 Jun 1999 07:14:53 GMT", "version": "v1" } ]
2009-10-31
[ [ "Pal", "Palash B.", "" ] ]
I start by defining the cosmological parameters $H_0, \Omega_m$ and $\Omega_\Lambda$. Then I show how the age of the universe depends on them, followed by the evolution of the scale parameter of the universe for various values of the density parameters. Then I define strategies for measuring them, and show the results for the recent determination of these parameters from measurements on supernovas of type 1a. Implications for particle physics is briefly discussed at the end.
1406.4760
Risto Paatelainen
R. Paatelainen, K. J. Eskola, H. Niemi, K. Tuominen
From minijet saturation to global observables in A + A collisions at the LHC and RHIC
Prepared for the Proceedings of "Hard Probes 2013", the 6th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions, Stellenbosch, South Africa, November 4-8, 2013
null
10.1016/j.nuclphysa.2014.10.007
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the recent results from the computation of saturated next-to-leading order perturbative QCD minijet intial conditions combined with viscous hydrodynamical evolution of ultrarelativistic heavy-ion collisions at the LHC and RHIC. Comparison with experimental data is shown.
[ { "created": "Wed, 30 Apr 2014 13:02:08 GMT", "version": "v1" } ]
2015-10-28
[ [ "Paatelainen", "R.", "" ], [ "Eskola", "K. J.", "" ], [ "Niemi", "H.", "" ], [ "Tuominen", "K.", "" ] ]
We review the recent results from the computation of saturated next-to-leading order perturbative QCD minijet intial conditions combined with viscous hydrodynamical evolution of ultrarelativistic heavy-ion collisions at the LHC and RHIC. Comparison with experimental data is shown.
2312.07462
Pragya Singh
Giuliano Giacalone, Bjoern Schenke, Soeren Schlichting, Pragya Singh
Small-x structure of oxygen and neon isotopes as seen by the Large Hadron Collider
4 pages, 3 figures, Contribution to Quark Matter 2023
null
null
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
Results on collisions of $^{16}$O nuclei performed at the Relativistic Heavy Ion Collider (RHIC) have been presented for the first time at Quark Matter 2023 by the STAR collaboration. $^{16}$O+$^{16}$O collisions are also expected to take place in the near future at the Large Hadron Collider (LHC) at much higher beam energies. We explore the potential of beam-energy-dependent studies for this system to probe small-$x$ dynamics and QCD evolution. We perform 3+1D IP-Glasma simulations to predict the rapidity dependence of the initial geometry of light-ion collisions, focusing on $^{16}$O+$^{16}$O and $^{20}$Ne+$^{20}$Ne collisions at $\sqrt{s_{\rm NN}} = 70$ GeV and 7 TeV. The choice of $^{20}$Ne is motivated by its strongly elongated geometry, which may respond differently to the effect of the high-energy evolution compared to the more spherical $^{16}$O. We find that smearing induced by soft gluon production at high energy causes mild variations in the initial-state eccentricities as a function of the collision energy. These effects could be resolved in future experiments and deserve further investigation.
[ { "created": "Tue, 12 Dec 2023 17:39:15 GMT", "version": "v1" } ]
2023-12-13
[ [ "Giacalone", "Giuliano", "" ], [ "Schenke", "Bjoern", "" ], [ "Schlichting", "Soeren", "" ], [ "Singh", "Pragya", "" ] ]
Results on collisions of $^{16}$O nuclei performed at the Relativistic Heavy Ion Collider (RHIC) have been presented for the first time at Quark Matter 2023 by the STAR collaboration. $^{16}$O+$^{16}$O collisions are also expected to take place in the near future at the Large Hadron Collider (LHC) at much higher beam energies. We explore the potential of beam-energy-dependent studies for this system to probe small-$x$ dynamics and QCD evolution. We perform 3+1D IP-Glasma simulations to predict the rapidity dependence of the initial geometry of light-ion collisions, focusing on $^{16}$O+$^{16}$O and $^{20}$Ne+$^{20}$Ne collisions at $\sqrt{s_{\rm NN}} = 70$ GeV and 7 TeV. The choice of $^{20}$Ne is motivated by its strongly elongated geometry, which may respond differently to the effect of the high-energy evolution compared to the more spherical $^{16}$O. We find that smearing induced by soft gluon production at high energy causes mild variations in the initial-state eccentricities as a function of the collision energy. These effects could be resolved in future experiments and deserve further investigation.
0909.4421
Jan Steinheimer
J. Steinheimer, S. Schramm, H. St\"ocker
An effective chiral Hadron-Quark Equation of State Part I: Zero baryochemical potential
8 pages, 8 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct an effective model for the QCD equation of state, taking into account chiral symmetry restoration as well as the deconfinement phase transition. The correct asymptotic degrees of freedom at the high and low temperature limits are included (quarks $\leftrightarrow$ hadrons). The model shows a rapid crossover for both order parameters, as is expected from lattice calculations. We then investigate the thermodynamic properties of the model at $\mu_B=0$. All thermodynamic quantities are in qualitative agreement with lattice data, while apparent quantitative differences can be attributed to hadronic contributions and excluded volume corrections.
[ { "created": "Thu, 24 Sep 2009 12:12:58 GMT", "version": "v1" } ]
2009-09-25
[ [ "Steinheimer", "J.", "" ], [ "Schramm", "S.", "" ], [ "Stöcker", "H.", "" ] ]
We construct an effective model for the QCD equation of state, taking into account chiral symmetry restoration as well as the deconfinement phase transition. The correct asymptotic degrees of freedom at the high and low temperature limits are included (quarks $\leftrightarrow$ hadrons). The model shows a rapid crossover for both order parameters, as is expected from lattice calculations. We then investigate the thermodynamic properties of the model at $\mu_B=0$. All thermodynamic quantities are in qualitative agreement with lattice data, while apparent quantitative differences can be attributed to hadronic contributions and excluded volume corrections.
1008.2379
Itzhak Bars
Itzhak Bars
Hunting for TeV Scale Strings at the LHC
64 pages
null
null
USC-10/HEP-B4, CERN-PH-TH/2010-181
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper I review the possibility of TeV scale strings that may be detectable by the Large Hadron Collider (LHC). This possibility was investigated extensively in a series of phenomenological papers during 1984-1985 in connection with the Superconducting Super Collider (SSC). The work was mainly based on a model independent systematic parametrization of scattering amplitudes and cross sections, for Standard Model particles, quarks and leptons, that were assumed to behave like strings, while gluons, photons, $W^{\pm},Z$ were taken as elementary. By using Veneziano type beta functions consistent with crossing symmetry, duality and Regge behavior, bosonic or fermionic resonances in each channel were included, while the low energy behavior was matched to effective field theory non-renormalizable interactions consistent with the Standard Model SU(3)xSU(2)xU(1) gauge symmetry as well as global flavor and family symmetries. The motivation for this approach at that time was the possible compositeness of quarks and leptons but the same phenomenological approach would apply effectively with the modern additional motivations for TeV scale strings, such as the hypothesis of D-branes with large extra dimensions. Because some of the main theoretical and phenomenological work of that time appeared only in the 1984 Snowmass and other proceedings, the results of the investigations have been inaccessible to most researchers and consequently have been largely forgotten. Meanwhile similar approaches are being explored by other researchers. Given the renewed interest in the old results, the purpose of the current paper is to make them readily available.
[ { "created": "Fri, 13 Aug 2010 19:51:16 GMT", "version": "v1" } ]
2010-08-16
[ [ "Bars", "Itzhak", "" ] ]
In this paper I review the possibility of TeV scale strings that may be detectable by the Large Hadron Collider (LHC). This possibility was investigated extensively in a series of phenomenological papers during 1984-1985 in connection with the Superconducting Super Collider (SSC). The work was mainly based on a model independent systematic parametrization of scattering amplitudes and cross sections, for Standard Model particles, quarks and leptons, that were assumed to behave like strings, while gluons, photons, $W^{\pm},Z$ were taken as elementary. By using Veneziano type beta functions consistent with crossing symmetry, duality and Regge behavior, bosonic or fermionic resonances in each channel were included, while the low energy behavior was matched to effective field theory non-renormalizable interactions consistent with the Standard Model SU(3)xSU(2)xU(1) gauge symmetry as well as global flavor and family symmetries. The motivation for this approach at that time was the possible compositeness of quarks and leptons but the same phenomenological approach would apply effectively with the modern additional motivations for TeV scale strings, such as the hypothesis of D-branes with large extra dimensions. Because some of the main theoretical and phenomenological work of that time appeared only in the 1984 Snowmass and other proceedings, the results of the investigations have been inaccessible to most researchers and consequently have been largely forgotten. Meanwhile similar approaches are being explored by other researchers. Given the renewed interest in the old results, the purpose of the current paper is to make them readily available.
1909.00123
Hyun-Chul Kim
June-Young Kim and Hyun-Chul Kim
Improved pion mean fields and masses of singly heavy baryons
18 pages, 4 figures. The final version for publication in PTEP
Prog Theor Exp Phys (2020)
10.1093/ptep/ptaa037
INHA-NTG-08/2019
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A singly heavy baryon can be viewed as $N_c-1$ ($N_c$ as the number of colors) light valence quarks bound by the pion mean fields that are created by the presence of the $N_c-1$ valence quarks self-consistently, while the heavy quark inside a singly heavy baryon is regarded as a static color source. We investigate how the pion mean fields are created by the presence of $N_c$, $N_c-1$, and $N_c-2$ light valence quarks, which correspond to the systems of light baryons, singly heavy baryons, and doubly heavy baryons. As the number of color decreases from $N_c$ to $N_c-1$, the pion mean fields undergo changes. As a result, the valence-quark contributions to the moments of inertia of the soliton become larger than the case of the $N_c$ valence quarks, whereas the sea-quark contributions decrease systematically. On the other hand, the presence of the $N_c-2$ valence quarks is not enough to produce the strong pion mean fields, which leads to the fact that the classical soliton can not be formed. It indicates that the pion mean-field approach is not suitable to describe doubly heavy baryons. We show that the mass spectra of the singly heavy baryons are better described by the improved pion mean fields, compared with the previous work in which the pion mean fields are assumed to be intact with $N_c$ varied.
[ { "created": "Sat, 31 Aug 2019 04:16:40 GMT", "version": "v1" }, { "created": "Mon, 2 Mar 2020 01:00:38 GMT", "version": "v2" } ]
2020-04-29
[ [ "Kim", "June-Young", "" ], [ "Kim", "Hyun-Chul", "" ] ]
A singly heavy baryon can be viewed as $N_c-1$ ($N_c$ as the number of colors) light valence quarks bound by the pion mean fields that are created by the presence of the $N_c-1$ valence quarks self-consistently, while the heavy quark inside a singly heavy baryon is regarded as a static color source. We investigate how the pion mean fields are created by the presence of $N_c$, $N_c-1$, and $N_c-2$ light valence quarks, which correspond to the systems of light baryons, singly heavy baryons, and doubly heavy baryons. As the number of color decreases from $N_c$ to $N_c-1$, the pion mean fields undergo changes. As a result, the valence-quark contributions to the moments of inertia of the soliton become larger than the case of the $N_c$ valence quarks, whereas the sea-quark contributions decrease systematically. On the other hand, the presence of the $N_c-2$ valence quarks is not enough to produce the strong pion mean fields, which leads to the fact that the classical soliton can not be formed. It indicates that the pion mean-field approach is not suitable to describe doubly heavy baryons. We show that the mass spectra of the singly heavy baryons are better described by the improved pion mean fields, compared with the previous work in which the pion mean fields are assumed to be intact with $N_c$ varied.
1411.7961
Zhi-Gang Wang
Zhi-Gang Wang
Semi-leptonic $B\to S$ decays in the standard model and in the universal extra dimension model
16 pages, 18 figures
Nucl. Phys. B 898 (2015) 431
10.1016/j.nuclphysb.2015.07.015
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article, we assume the two nonets of scalar mesons below and above 1 GeV are all $\bar{q}q$ states, and study the semi-leptonic decays $B\to S\ell^-\bar{\nu}_{\ell}$, $B\to S\ell^+\ell^-$ and $B\to S\bar{\nu}\nu$ both in the standard model and in the universal extra dimension model using the $B-S$ form-factors calculated by the light-cone QCD sum rules in our previous work. We obtain the partial decay widths and decay widths, which can be confronted with the experimental data in the future to examine the natures of the scalar mesons and constrain the basic parameter in the universal extra dimension model, the compactification scale $1/R$.
[ { "created": "Wed, 26 Nov 2014 08:13:40 GMT", "version": "v1" }, { "created": "Thu, 16 Apr 2015 01:07:34 GMT", "version": "v2" }, { "created": "Wed, 24 Jun 2015 00:19:20 GMT", "version": "v3" } ]
2015-08-03
[ [ "Wang", "Zhi-Gang", "" ] ]
In this article, we assume the two nonets of scalar mesons below and above 1 GeV are all $\bar{q}q$ states, and study the semi-leptonic decays $B\to S\ell^-\bar{\nu}_{\ell}$, $B\to S\ell^+\ell^-$ and $B\to S\bar{\nu}\nu$ both in the standard model and in the universal extra dimension model using the $B-S$ form-factors calculated by the light-cone QCD sum rules in our previous work. We obtain the partial decay widths and decay widths, which can be confronted with the experimental data in the future to examine the natures of the scalar mesons and constrain the basic parameter in the universal extra dimension model, the compactification scale $1/R$.
1609.06977
Mark Goodsell
Johannes Braathen and Mark D. Goodsell
Avoiding the Goldstone Boson Catastrophe in general renormalisable field theories at two loops
42 pages, one figure; v2: corrected typos and added explanations
null
10.1007/JHEP12(2016)056
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show how the infra-red divergences associated to Goldstone bosons in the minimum condition of the two-loop Landau-gauge effective potential can be avoided in general field theories. This extends the resummation formalism recently developed for the Standard Model and the MSSM, and we give compact, infra-red finite expressions in closed form for the tadpole equations. We also show that the results at this loop order are equivalent to (and are most easily obtained by) imposing an "on-shell" condition for the Goldstone bosons. Moreover, we extend the approach to show how the infra-red divergences in the calculation of the masses of neutral scalars (such as the Higgs boson) can be eliminated. For the mass computation, we specialise to the gaugeless limit and extend the effective potential computation to allow the masses to be determined without needing to solve differential equations for the loop functions -- opening the door to fast, infra-red safe determinations of the Higgs mass in general theories.
[ { "created": "Thu, 22 Sep 2016 13:49:41 GMT", "version": "v1" }, { "created": "Mon, 24 Oct 2016 14:16:48 GMT", "version": "v2" } ]
2017-02-01
[ [ "Braathen", "Johannes", "" ], [ "Goodsell", "Mark D.", "" ] ]
We show how the infra-red divergences associated to Goldstone bosons in the minimum condition of the two-loop Landau-gauge effective potential can be avoided in general field theories. This extends the resummation formalism recently developed for the Standard Model and the MSSM, and we give compact, infra-red finite expressions in closed form for the tadpole equations. We also show that the results at this loop order are equivalent to (and are most easily obtained by) imposing an "on-shell" condition for the Goldstone bosons. Moreover, we extend the approach to show how the infra-red divergences in the calculation of the masses of neutral scalars (such as the Higgs boson) can be eliminated. For the mass computation, we specialise to the gaugeless limit and extend the effective potential computation to allow the masses to be determined without needing to solve differential equations for the loop functions -- opening the door to fast, infra-red safe determinations of the Higgs mass in general theories.
1811.03294
Tae Hyun Jung
Kwang Sik Jeong, Tae Hyun Jung, and Chang Sub Shin
Adiabatic Electroweak Baryogenesis Driven by an Axion-like Particle
12 pages, 5 figures, appendices added, published version
Phys. Rev. D 101, 035009 (2020)
10.1103/PhysRevD.101.035009
CTPU-18-34, PNUTP-18-A12
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An axion-like particle (ALP) offers a new direction in electroweak baryogenesis because the periodic nature enables it to trigger a strong first-order phase transition insensitively to the decay constant $f$. For $f$ much above TeV, the ALP-induced electroweak phase transition is approximately described by adiabatic processes, distinguishing our scenario for electroweak baryogenesis from the conventional ones. We show that, coupled to the electroweak anomaly, the ALP can naturally realize spontaneous electroweak baryogenesis to solve the matter-antimatter asymmetry problem for $f$ in the range between about $10^5$ GeV and $10^7$ GeV. In such an ALP window, the $CP$ violation for baryogenesis is totally free from the experimental constraints, especially from the recently improved limit on the electron electric dipole moment. Future searches for ALPs could probe our scenario while revealing the connection between electroweak symmetry breaking and baryogenesis.
[ { "created": "Thu, 8 Nov 2018 07:25:21 GMT", "version": "v1" }, { "created": "Fri, 14 Jun 2019 04:22:48 GMT", "version": "v2" }, { "created": "Tue, 4 Feb 2020 22:40:41 GMT", "version": "v3" } ]
2020-02-12
[ [ "Jeong", "Kwang Sik", "" ], [ "Jung", "Tae Hyun", "" ], [ "Shin", "Chang Sub", "" ] ]
An axion-like particle (ALP) offers a new direction in electroweak baryogenesis because the periodic nature enables it to trigger a strong first-order phase transition insensitively to the decay constant $f$. For $f$ much above TeV, the ALP-induced electroweak phase transition is approximately described by adiabatic processes, distinguishing our scenario for electroweak baryogenesis from the conventional ones. We show that, coupled to the electroweak anomaly, the ALP can naturally realize spontaneous electroweak baryogenesis to solve the matter-antimatter asymmetry problem for $f$ in the range between about $10^5$ GeV and $10^7$ GeV. In such an ALP window, the $CP$ violation for baryogenesis is totally free from the experimental constraints, especially from the recently improved limit on the electron electric dipole moment. Future searches for ALPs could probe our scenario while revealing the connection between electroweak symmetry breaking and baryogenesis.
hep-ph/0311273
Steffen Schumann
T. Gleisberg, F. Krauss, C. G. Papadopoulos, A. Schaelicke, and S. Schumann
Cross sections for multi-particle final states at a linear collider
8 pages
Eur.Phys.J. C34 (2004) 173-180
10.1140/epjc/s2004-01672-1
null
hep-ph
null
In this paper total cross sections for signals and backgrounds of top- and Higgs-production channels in electron-positron collisions at a future linear collider are presented. All channels considered are characterized by the emergence of six-particle final states. The calculation takes into account the full set of tree-level amplitudes in each process. Two multi-purpose parton level generators, HELAC/PHEGAS and AMEGIC++ are used, their results are found to be in perfect agreement.
[ { "created": "Fri, 21 Nov 2003 12:35:41 GMT", "version": "v1" } ]
2009-11-10
[ [ "Gleisberg", "T.", "" ], [ "Krauss", "F.", "" ], [ "Papadopoulos", "C. G.", "" ], [ "Schaelicke", "A.", "" ], [ "Schumann", "S.", "" ] ]
In this paper total cross sections for signals and backgrounds of top- and Higgs-production channels in electron-positron collisions at a future linear collider are presented. All channels considered are characterized by the emergence of six-particle final states. The calculation takes into account the full set of tree-level amplitudes in each process. Two multi-purpose parton level generators, HELAC/PHEGAS and AMEGIC++ are used, their results are found to be in perfect agreement.
1603.04514
Monojit Ghosh
Monojit Ghosh
Present Aspects and Future Prospects of Neutrino Mass and Oscillation
PhD Thesis, Based on arXiv:1306.2500, arXiv:1401.7243, arXiv:1308.5979, arXiv:1412.1744, arXiv:1312.6593, arXiv:1211.0118 and arXiv:1305.0180. First two chapters contain the basics of neutrino oscillation physics
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Neutrinos are neutral, spin-$\frac{1}{2}$ particles which undergo only weak interactions. The experimentally observed phenomenon of neutrino oscillation establishes the fact that neutrinos are massive and there is mixing between different neutrino flavours. This constitutes the first unambiguous hint towards the physics Beyond Standard Model (BSM). In the BSM theories, the neutrino mass terms in the Lagrangian lead to the non-diagonal neutrino mass matrix in the flavour basis which depends on neutrino mass and mixing parameters. Thus knowledge of the neutrino oscillation parameters and understanding the underlying symmetries of the neutrino mass matrix are very important as they can give an insight to the new physics beyond Standard Model. Therefore the measurement of different oscillation parameters and studying the structure of the neutrino mass matrix are some of the main goals in neutrino physics at present. In this thesis we have studied the potential of present/future neutrino oscillation experiments and synergy between them to determine the unknown parameters in the neutrino sector in the light of current experimental results. We have also studied the phenomenological consequences of texture zeros in the neutrino mass matrices in the presence of a sterile neutrino.
[ { "created": "Tue, 15 Mar 2016 00:26:15 GMT", "version": "v1" } ]
2016-03-16
[ [ "Ghosh", "Monojit", "" ] ]
Neutrinos are neutral, spin-$\frac{1}{2}$ particles which undergo only weak interactions. The experimentally observed phenomenon of neutrino oscillation establishes the fact that neutrinos are massive and there is mixing between different neutrino flavours. This constitutes the first unambiguous hint towards the physics Beyond Standard Model (BSM). In the BSM theories, the neutrino mass terms in the Lagrangian lead to the non-diagonal neutrino mass matrix in the flavour basis which depends on neutrino mass and mixing parameters. Thus knowledge of the neutrino oscillation parameters and understanding the underlying symmetries of the neutrino mass matrix are very important as they can give an insight to the new physics beyond Standard Model. Therefore the measurement of different oscillation parameters and studying the structure of the neutrino mass matrix are some of the main goals in neutrino physics at present. In this thesis we have studied the potential of present/future neutrino oscillation experiments and synergy between them to determine the unknown parameters in the neutrino sector in the light of current experimental results. We have also studied the phenomenological consequences of texture zeros in the neutrino mass matrices in the presence of a sterile neutrino.
2012.06367
Rafal Maciula
Rafal Maciula
Production of $\nu_\tau$ neutrinos and $\overline{\nu}_tau$ antineutrinos -- elaborate calculation for a fixed target experiment SHiP
talk given by R. Maciula at the 40th International Conference on High Energy physics - ICHEP2020, July 28 - August 6, 2020, Prague, Czech Republic (virtual meeting)
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We discuss cross sections for $\nu_{\tau}$ and ${\overline \nu}_{\tau}$ production from the direct $D_s^{\pm} \to \nu_{\tau}/{\overline \nu}_{\tau}$ and chain $D_s^{\pm} \to \tau^+/\tau^- \to \nu_{\tau}/{\overline \nu}_{\tau}$ decays in $p\!+^{96}\!\mathrm{Mo}$ scattering with proton beam $E_{\mathrm{lab}}$ = 400 GeV \textit{i.e.} at $\sqrt{s}_{NN}$ = 27.4 GeV. In our calculations we include $D_s^{\pm}$ from charm fragmentation $c \to D_s^{+}$ and $\bar c \to D_s^-$ as well as those from subleading fragmentation of strange quarks/antiquarks $s \to D_s^-$ and $\bar s \to D_s^+$. The different contributions to $D_s^{\pm}$ and $\nu_{\tau} / {\overline \nu}_{\tau}$ production rates are shown explicitly. Estimates of a number of observed $\nu_{\tau} / \overline{\nu}_{\tau}$ in the $\nu_{\tau} / \overline{\nu}_{\tau} +^{208}\!\mathrm{Pb}$ reaction, with 2m long target are given.
[ { "created": "Fri, 11 Dec 2020 14:16:31 GMT", "version": "v1" } ]
2020-12-14
[ [ "Maciula", "Rafal", "" ] ]
We discuss cross sections for $\nu_{\tau}$ and ${\overline \nu}_{\tau}$ production from the direct $D_s^{\pm} \to \nu_{\tau}/{\overline \nu}_{\tau}$ and chain $D_s^{\pm} \to \tau^+/\tau^- \to \nu_{\tau}/{\overline \nu}_{\tau}$ decays in $p\!+^{96}\!\mathrm{Mo}$ scattering with proton beam $E_{\mathrm{lab}}$ = 400 GeV \textit{i.e.} at $\sqrt{s}_{NN}$ = 27.4 GeV. In our calculations we include $D_s^{\pm}$ from charm fragmentation $c \to D_s^{+}$ and $\bar c \to D_s^-$ as well as those from subleading fragmentation of strange quarks/antiquarks $s \to D_s^-$ and $\bar s \to D_s^+$. The different contributions to $D_s^{\pm}$ and $\nu_{\tau} / {\overline \nu}_{\tau}$ production rates are shown explicitly. Estimates of a number of observed $\nu_{\tau} / \overline{\nu}_{\tau}$ in the $\nu_{\tau} / \overline{\nu}_{\tau} +^{208}\!\mathrm{Pb}$ reaction, with 2m long target are given.
hep-ph/9509336
Michael Martin Nieto
Michael H. Holzscheiter, T. Goldman, and Michael Martin Nieto
Antimatter Gravity and Antihydrogen Production
13 pages, LaTeX
New Frontiers in Hadronic Mechanics, Part III: Experimental and Theoretical Studies on Antimatter}, ed. T. L. Gili (Hadronic Press, Palm Harbor, FL., 1996) 319
null
LA-UR-95-2776
hep-ph
null
Certain modern theories of gravity predict that antimatter will fall differently than matter in the Earth's gravitational field. However, no experimental tests of gravity on antimatter exist and all conclusions drawn from experiments on matter depend, at some level, on a specific model. We have proposed a direct measurement that would compare the gravitational acceleration of antiprotons to that of negatively charged hydrogen ions. Substantial progress towards the development of this experiment has been achieved. Based on our work a number of alternative proposals for measuring ``$g$" on both charged and neutral antimatter have been made. We summarize the present status of our experiment and also discuss the steps that would be necessary to produce antihydrogen in an environment suitable for gravity measurements.
[ { "created": "Tue, 19 Sep 1995 20:08:11 GMT", "version": "v1" } ]
2007-05-23
[ [ "Holzscheiter", "Michael H.", "" ], [ "Goldman", "T.", "" ], [ "Nieto", "Michael Martin", "" ] ]
Certain modern theories of gravity predict that antimatter will fall differently than matter in the Earth's gravitational field. However, no experimental tests of gravity on antimatter exist and all conclusions drawn from experiments on matter depend, at some level, on a specific model. We have proposed a direct measurement that would compare the gravitational acceleration of antiprotons to that of negatively charged hydrogen ions. Substantial progress towards the development of this experiment has been achieved. Based on our work a number of alternative proposals for measuring ``$g$" on both charged and neutral antimatter have been made. We summarize the present status of our experiment and also discuss the steps that would be necessary to produce antihydrogen in an environment suitable for gravity measurements.
hep-ph/9605204
W. S. Hou
George Wei-Shu Hou (National Taiwan University)
Possible Resonances in $\mu^+e^- \to \mu^- e^+$ Collisions
10 pages plus separate cover page, latex, 5 embedded eps figures. Talk presented at 3rd International Conference on $\mu^+\mu^-$ Colliders, December 1995, San Francisco, USA
Nucl.Phys.Proc.Suppl. 51A (1996) 40-49
null
NTUTH-96-05
hep-ph
null
We study the possibility of discovering resonances in $\mu^+e^- \to \mu^- e^+$ and $e^-e^- \to \mu^- \mu^-$ collisions. We begin with the closely related problem of muonium--antimuonium transitions, where the experimental limit has just been improved by one order of magnitude. We show that the new limit enters a rather interesting mass and Yukawa coupling domain for neutral scalar bosons. The stringent $\mu\to e\gamma$ decay is evaded by invoking some multiplicative lepton number. Neutral and doubly charged scalar bosons give rise to distinguishable effects in muonium transitions. Alternatively, they could show up as spectacular resonance peaks in high energy $\mu^+e^- \to \mu^- e^+$and $e^-e^- \to \mu^- \mu^-$ collisions, respectively. This could occur independent of whether, but especially when, muonium-antimuonium transitions are experimentally observed.
[ { "created": "Thu, 2 May 1996 19:58:33 GMT", "version": "v1" } ]
2007-05-23
[ [ "Hou", "George Wei-Shu", "", "National Taiwan University" ] ]
We study the possibility of discovering resonances in $\mu^+e^- \to \mu^- e^+$ and $e^-e^- \to \mu^- \mu^-$ collisions. We begin with the closely related problem of muonium--antimuonium transitions, where the experimental limit has just been improved by one order of magnitude. We show that the new limit enters a rather interesting mass and Yukawa coupling domain for neutral scalar bosons. The stringent $\mu\to e\gamma$ decay is evaded by invoking some multiplicative lepton number. Neutral and doubly charged scalar bosons give rise to distinguishable effects in muonium transitions. Alternatively, they could show up as spectacular resonance peaks in high energy $\mu^+e^- \to \mu^- e^+$and $e^-e^- \to \mu^- \mu^-$ collisions, respectively. This could occur independent of whether, but especially when, muonium-antimuonium transitions are experimentally observed.
hep-ph/9505433
Tim Stelzer
T. Stelzer and S. Willenbrock
Single-top-quark production via q qbar -> t bbar
12 pages latex + 5 uuencoded figures
Phys.Lett. B357 (1995) 125-130
10.1016/0370-2693(95)00861-E
DTP/95/40, ILL-(TH)-95-30
hep-ph
null
We consider single-top-quark production via the weak process $q\bar q to t\bar b$ at hadron colliders. This process may provide the best measurement of the magnitude of the Cabbibo-Kobayashi-Maskawa matrix element $V_{tb}$. We show that a signal can potentially be observed at the Fermilab Tevatron with 3 $fb^{-1}$ of integrated luminosity. In contrast, the signal is masked at the CERN Large Hadron Collider by top-quark pair production and single-top-quark production via $W$-gluon fusion.
[ { "created": "Wed, 31 May 1995 13:12:47 GMT", "version": "v1" } ]
2009-10-28
[ [ "Stelzer", "T.", "" ], [ "Willenbrock", "S.", "" ] ]
We consider single-top-quark production via the weak process $q\bar q to t\bar b$ at hadron colliders. This process may provide the best measurement of the magnitude of the Cabbibo-Kobayashi-Maskawa matrix element $V_{tb}$. We show that a signal can potentially be observed at the Fermilab Tevatron with 3 $fb^{-1}$ of integrated luminosity. In contrast, the signal is masked at the CERN Large Hadron Collider by top-quark pair production and single-top-quark production via $W$-gluon fusion.
hep-ph/0610427
Jeremy Miller
Jeremy S. Miller
Survival probability in diffractive Higgs production in high density QCD
28 pages, 7 figures
Eur.Phys.J.C56:39-55,2008
10.1140/epjc/s10052-008-0641-3
TAUP 2839/06
hep-ph
null
In this paper, the contribution of hard processes described by the BFKL pomeron exchange, is taken into account by calculating the first enhanced diagram. The survival probability is estimated, using the ratio of the first enhanced diagram and the single pomeron amplitude, taking into account all essential pomeron loop diagrams in the toy model of Mueller. The triple pomeron vertex is calculated explicitly in the momentum representation. This calculation is used for estimating the survival probability, It turns out that the survival probability is small, at $0.4%{}$. Hard pomeron re-scattering processes contribute substantially to the survival probability.
[ { "created": "Tue, 31 Oct 2006 13:27:10 GMT", "version": "v1" }, { "created": "Thu, 8 Nov 2007 13:33:17 GMT", "version": "v2" } ]
2008-11-26
[ [ "Miller", "Jeremy S.", "" ] ]
In this paper, the contribution of hard processes described by the BFKL pomeron exchange, is taken into account by calculating the first enhanced diagram. The survival probability is estimated, using the ratio of the first enhanced diagram and the single pomeron amplitude, taking into account all essential pomeron loop diagrams in the toy model of Mueller. The triple pomeron vertex is calculated explicitly in the momentum representation. This calculation is used for estimating the survival probability, It turns out that the survival probability is small, at $0.4%{}$. Hard pomeron re-scattering processes contribute substantially to the survival probability.
0705.1995
James Dent
James B. Dent and Thomas W. Kephart
Minimal Pati-Salam Model from String Theory Unification
8 pages
Phys.Rev.D77:115008,2008
10.1103/PhysRevD.77.115008
null
hep-ph
null
We provide what we believe is the minimal three family ${\cal N} = 1$ SUSY and conformal Pati-Salam Model from type IIB superstring theory. This $Z_3$ orbifolded AdS$\otimes S^5$ model has long lived protons and has potential phenomenological consequences for LHC.
[ { "created": "Mon, 14 May 2007 17:40:55 GMT", "version": "v1" } ]
2008-11-26
[ [ "Dent", "James B.", "" ], [ "Kephart", "Thomas W.", "" ] ]
We provide what we believe is the minimal three family ${\cal N} = 1$ SUSY and conformal Pati-Salam Model from type IIB superstring theory. This $Z_3$ orbifolded AdS$\otimes S^5$ model has long lived protons and has potential phenomenological consequences for LHC.
hep-ph/9711284
Cao Fu-guang
Fu-Guang Cao and Tao Huang
Large corrections to asymptotic $F_{\eta_c \gamma}$ and $F_{\eta_b \gamma}$ in the light-cone perturbative QCD
8 pages, RevTex, 5 PostScript figures
Phys.Rev.D59:093004,1999
10.1103/PhysRevD.59.093004
null
hep-ph
null
The large-$Q^2$ behavior of $\eta_c$-$\gamma$ and $\eta_b$-$\gamma$ transition form factors, $F_{\eta_c\gamma}(Q^2)$ and $F_{\eta_b\gamma}(Q^2)$ are analyzed in the framework of light-cone perturbative QCD with the heavy quark ($c$ and $b$) mass effect, the parton's transverse momentum dependence and the higher helicity components in the light-cone wave function are respected. It is pointed out that the quark mass effect brings significant modifications to the asymptotic predictions of the transition form factors in a rather broad energy region, and this modification is much severer for $F_{\eta_b\gamma}(Q^2)$ than that for $F_{\eta_c\gamma}(Q^2)$ due to the $b$-quark being heavier than the $c$-quark. The parton's transverse momentum and the higher helicity components are another two factors which decrease the perturbative predictions. For the transition form factor $F_{\eta_c\gamma}(Q^2)$, they bring sizable corrections in the present experimentally accessible energy region ($Q^2 \leq 10 GeV^2$). For the transition form factor $F_{\eta_b\gamma}(Q^2)$, the corrections coming from these two factors are negligible since the $b$-quark mass is much larger than the parton's average transverse momentum. The coming $e^+ e^-$ collider (LEP2) will provide the opportunity to examine these theoretical predictions.
[ { "created": "Tue, 11 Nov 1997 06:39:04 GMT", "version": "v1" }, { "created": "Wed, 12 Nov 1997 01:11:02 GMT", "version": "v2" }, { "created": "Sat, 15 Nov 1997 09:03:23 GMT", "version": "v3" } ]
2011-01-27
[ [ "Cao", "Fu-Guang", "" ], [ "Huang", "Tao", "" ] ]
The large-$Q^2$ behavior of $\eta_c$-$\gamma$ and $\eta_b$-$\gamma$ transition form factors, $F_{\eta_c\gamma}(Q^2)$ and $F_{\eta_b\gamma}(Q^2)$ are analyzed in the framework of light-cone perturbative QCD with the heavy quark ($c$ and $b$) mass effect, the parton's transverse momentum dependence and the higher helicity components in the light-cone wave function are respected. It is pointed out that the quark mass effect brings significant modifications to the asymptotic predictions of the transition form factors in a rather broad energy region, and this modification is much severer for $F_{\eta_b\gamma}(Q^2)$ than that for $F_{\eta_c\gamma}(Q^2)$ due to the $b$-quark being heavier than the $c$-quark. The parton's transverse momentum and the higher helicity components are another two factors which decrease the perturbative predictions. For the transition form factor $F_{\eta_c\gamma}(Q^2)$, they bring sizable corrections in the present experimentally accessible energy region ($Q^2 \leq 10 GeV^2$). For the transition form factor $F_{\eta_b\gamma}(Q^2)$, the corrections coming from these two factors are negligible since the $b$-quark mass is much larger than the parton's average transverse momentum. The coming $e^+ e^-$ collider (LEP2) will provide the opportunity to examine these theoretical predictions.
hep-ph/9508232
null
N.Armesto, C.Pajares, C.A.Salgado and Yu.M.Shabelski
A-Dependence of Heavy Flavour Production in QCD
7 pages (LaTeX) + 3 uuencoded-compressed-tar postcript figures in a separate file
Phys.Lett.B366:276-280,1996
10.1016/0370-2693(95)01330-X
US-FT/22-95
hep-ph
null
We calculate the A-dependence of charm and beauty production cross sections on nuclear targets taking into account the difference of quark and gluon distributions in free nucleons and in nucleus. At comparatively low energies, if $\sigma \sim A^{\alpha}$, the value of $\alpha$ is slightly higher than unity. With the growth of the initial energy the value of $\alpha$ decreases and becomes smaller than unity. We also calculate the values of $\alpha$ for different Feynman-$x$ of the produced $Q\overline{Q}$ pair and obtain that they decrease significantly in the beam fragmentation region.
[ { "created": "Fri, 4 Aug 1995 04:28:15 GMT", "version": "v1" }, { "created": "Mon, 14 Aug 1995 04:19:29 GMT", "version": "v2" } ]
2014-11-17
[ [ "Armesto", "N.", "" ], [ "Pajares", "C.", "" ], [ "Salgado", "C. A.", "" ], [ "Shabelski", "Yu. M.", "" ] ]
We calculate the A-dependence of charm and beauty production cross sections on nuclear targets taking into account the difference of quark and gluon distributions in free nucleons and in nucleus. At comparatively low energies, if $\sigma \sim A^{\alpha}$, the value of $\alpha$ is slightly higher than unity. With the growth of the initial energy the value of $\alpha$ decreases and becomes smaller than unity. We also calculate the values of $\alpha$ for different Feynman-$x$ of the produced $Q\overline{Q}$ pair and obtain that they decrease significantly in the beam fragmentation region.
hep-ph/0109051
V. Shevchenko
V.Shevchenko, Yu.Simonov
Operator product expansion and confinement
LaTeX, 29 pages
Phys.Rev. D65 (2002) 074029
10.1103/PhysRevD.65.074029
null
hep-ph hep-th
null
Operator product expansion technique is analyzed in abelian and nonabelian nonsupersymmetric field theoretical models with confinement. Special attention is paid to the regimes where nonzero virtuality of vacuum fields is felt by external currents. It is stressed that despite physics of confinement is sometimes considered as being caused by "soft" vacuum gluon fields, it can exhibit pronounced "hard" effects in OPE both in coordinate and momentum spaces.
[ { "created": "Thu, 6 Sep 2001 18:46:02 GMT", "version": "v1" } ]
2009-11-07
[ [ "Shevchenko", "V.", "" ], [ "Simonov", "Yu.", "" ] ]
Operator product expansion technique is analyzed in abelian and nonabelian nonsupersymmetric field theoretical models with confinement. Special attention is paid to the regimes where nonzero virtuality of vacuum fields is felt by external currents. It is stressed that despite physics of confinement is sometimes considered as being caused by "soft" vacuum gluon fields, it can exhibit pronounced "hard" effects in OPE both in coordinate and momentum spaces.
hep-ph/0210276
Xing ZhiZhong
Zhi-zhong Xing
Hierarchical Neutrino Masses and Large Mixing Angles from the Fritzsch Texture of Lepton Mass Matrices
LaTex 15 pages (5 PS figures). More discussions added
Phys.Lett. B550 (2002) 178-185
10.1016/S0370-2693(02)02981-7
BIHEP-TH-2002-48
hep-ph
null
We show that the Fritzsch texture of lepton mass matrices can naturally lead to the bi-large flavor mixing pattern, if three neutrinos have a normal but weak mass hierarchy (typically, $m_1 : m_2 : m_3 \sim 1 : 3 :10$). The effective mass of the tritium beta decay and that of the neutrinoless double beta decay are too small to be observable in this ansatz, but CP violation at the percent level is allowed and could be measured in long-baseline neutrino oscillations.
[ { "created": "Mon, 21 Oct 2002 03:40:24 GMT", "version": "v1" }, { "created": "Wed, 6 Nov 2002 07:20:57 GMT", "version": "v2" } ]
2010-04-05
[ [ "Xing", "Zhi-zhong", "" ] ]
We show that the Fritzsch texture of lepton mass matrices can naturally lead to the bi-large flavor mixing pattern, if three neutrinos have a normal but weak mass hierarchy (typically, $m_1 : m_2 : m_3 \sim 1 : 3 :10$). The effective mass of the tritium beta decay and that of the neutrinoless double beta decay are too small to be observable in this ansatz, but CP violation at the percent level is allowed and could be measured in long-baseline neutrino oscillations.
1201.0537
Antonio Pich
Antonio Pich
The Standard Model of Electroweak Interactions
Based on lectures given at the 6th CERN-Fermilab Hadron Collider Physics Summer School (Geneva, 2011), 2010 European School of HEP (Raseborg, Finland), 2010 Int. School on Astroparticle Physics (Zaragoza, Spain), 2010 IDPASC School (Sesimbra, Portugal) and 2009 Int. Summer School and Conference on HEP (Mugla, Turkey, 2009). 52 pages, 38 figures
CERN-2012-001, pp.1-50
null
IFIC/11-73; FTUV/12-0102
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Gauge invariance is a powerful tool to determine the dynamical forces among the fundamental constituents of matter. The particle content, structure and symmetries of the Standard Model Lagrangian are discussed. Special emphasis is given to the many phenomenological tests which have established this theoretical framework as the Standard Theory of the electroweak interactions: electroweak precision tests, Higgs searches, quark mixing, neutrino oscillations. The present experimental status is summarized.
[ { "created": "Mon, 2 Jan 2012 21:26:31 GMT", "version": "v1" } ]
2012-01-31
[ [ "Pich", "Antonio", "" ] ]
Gauge invariance is a powerful tool to determine the dynamical forces among the fundamental constituents of matter. The particle content, structure and symmetries of the Standard Model Lagrangian are discussed. Special emphasis is given to the many phenomenological tests which have established this theoretical framework as the Standard Theory of the electroweak interactions: electroweak precision tests, Higgs searches, quark mixing, neutrino oscillations. The present experimental status is summarized.
hep-ph/0507210
Sourendu Gupta
Sourendu Gupta
Dissipation, hydrodynamics and the fireball
4 pages
null
null
TIFR/TH/05-28
hep-ph nucl-ex nucl-th
null
We investigate the hydrodynamics of the QCD plasma using dimensionless numbers built from the thermodynamics and transport theory of the plasma and characteristic dimensions of the fireball produced in heavy-ion collisions. We find that by the usual measures, dissipation is strong, and the fireball is on the borderline of equilibrium. As a result, the system is richer in phenomena than ideal hydrodynamics would predict. One general implication is that it may be possible to get a direct view of the QCD plasma phase rather than having to infer its existence indirectly from signals that come from the freezeout isotherm after the fireball has cooled into the hadronic phase.
[ { "created": "Mon, 18 Jul 2005 13:05:04 GMT", "version": "v1" } ]
2007-05-23
[ [ "Gupta", "Sourendu", "" ] ]
We investigate the hydrodynamics of the QCD plasma using dimensionless numbers built from the thermodynamics and transport theory of the plasma and characteristic dimensions of the fireball produced in heavy-ion collisions. We find that by the usual measures, dissipation is strong, and the fireball is on the borderline of equilibrium. As a result, the system is richer in phenomena than ideal hydrodynamics would predict. One general implication is that it may be possible to get a direct view of the QCD plasma phase rather than having to infer its existence indirectly from signals that come from the freezeout isotherm after the fireball has cooled into the hadronic phase.
0903.0525
Igor Lokhtin P.
I.P.Lokhtin, L.V.Malinina, S.V.Petrushanko, A.M.Snigirev, I.Arsene, K.Tywoniuk
HYDJET++ heavy ion event generator and its applications for RHIC and LHC
Talk given at 4th International Workshop on High-pT physics at LHC (Prague, Czech Republic, February 4-7, 2009); 12 pages including 7 figures as EPS-files; prepared using LaTeX package for publication in Proceedings of Science (PoS)
PoS High-pTphysics09:023,2009
10.1088/1126-6708/2009/09/023
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The heavy ion event generator HYDJET++ is presented. HYDJET++ simulates relativistic heavy ion AA collisions as a superposition of the soft, hydro-type state and the hard state resulting from multi-parton fragmentation. This model is the development and continuation of HYDJET event generator. The hard parts of HYDJET and HYDJET++ are identical. The soft part of HYDJET++ contains the following important additional features as compared with HYDJET: resonance decays and more detailed treatment of thermal and chemical freeze-out hypersurfaces. HYDJET++ is capable of reproducing the bulk properties of heavy ion collisions at RHIC (hadron spectra and ratios, radial and elliptic flow, femtoscopic momentum correlations), as well as high-pT hadron spectra. Some applications of HYDJET++ at LHC are discussed.
[ { "created": "Tue, 3 Mar 2009 13:17:29 GMT", "version": "v1" } ]
2015-05-13
[ [ "Lokhtin", "I. P.", "" ], [ "Malinina", "L. V.", "" ], [ "Petrushanko", "S. V.", "" ], [ "Snigirev", "A. M.", "" ], [ "Arsene", "I.", "" ], [ "Tywoniuk", "K.", "" ] ]
The heavy ion event generator HYDJET++ is presented. HYDJET++ simulates relativistic heavy ion AA collisions as a superposition of the soft, hydro-type state and the hard state resulting from multi-parton fragmentation. This model is the development and continuation of HYDJET event generator. The hard parts of HYDJET and HYDJET++ are identical. The soft part of HYDJET++ contains the following important additional features as compared with HYDJET: resonance decays and more detailed treatment of thermal and chemical freeze-out hypersurfaces. HYDJET++ is capable of reproducing the bulk properties of heavy ion collisions at RHIC (hadron spectra and ratios, radial and elliptic flow, femtoscopic momentum correlations), as well as high-pT hadron spectra. Some applications of HYDJET++ at LHC are discussed.
hep-ph/9409307
Murray Moinester
Murray A. Moinester
Chiral Anomaly Tests
4 pages text (latex) uses ws-art.sty file (appended, following anomaly.tex), which requires extracting and setting ws-art.sty in your directory, in addition to the tex file, TAUP-2176-94, revision for minor proofreading correction, submitted to Proceedings of the Conference on Physics with GeV-Particle Beams, Juelich, Germany, Aug. 1994, World Scientific, Eds. H. Machner and K. Sistemich
null
null
null
hep-ph nucl-th
null
For the gamma-pion interaction, the perturbative expansion of the effective chiral Lagrangian (chi-PT) can be limited to terms quartic in momenta and masses (O(p4)), or to higher order. The abnormal intrinsic parity (chiral anomaly) component of the lagrangian leads to interesting predictions for the processes pi0 -----> 2 gamma and gamma ----->3 pi. These are described by the amplitudes F_{pi} and F_{3pi}, respectively. We demonstrate that the O(p4) value of F_{3pi} disagrees with existing data, while the O(p6) value is nearly consistent. We describe how Fermilab experiment E781 can get improved data for tests of the chiral anomaly.
[ { "created": "Wed, 14 Sep 1994 11:18:42 GMT", "version": "v1" }, { "created": "Fri, 16 Sep 1994 12:33:19 GMT", "version": "v2" } ]
2008-02-03
[ [ "Moinester", "Murray A.", "" ] ]
For the gamma-pion interaction, the perturbative expansion of the effective chiral Lagrangian (chi-PT) can be limited to terms quartic in momenta and masses (O(p4)), or to higher order. The abnormal intrinsic parity (chiral anomaly) component of the lagrangian leads to interesting predictions for the processes pi0 -----> 2 gamma and gamma ----->3 pi. These are described by the amplitudes F_{pi} and F_{3pi}, respectively. We demonstrate that the O(p4) value of F_{3pi} disagrees with existing data, while the O(p6) value is nearly consistent. We describe how Fermilab experiment E781 can get improved data for tests of the chiral anomaly.
hep-ph/0505239
Robin Ni{\ss}ler
B. Borasoy, R. Nissler, W. Weise
Chiral dynamics of kaon-nucleon interactions, revisited
30 pages, 14 figures, 11 tables
Eur.Phys.J.A25:79-96,2005
10.1140/epja/i2005-10079-1
null
hep-ph nucl-th
null
The anti-kaon nucleon system close to threshold is analyzed in view of the new accurate DEAR kaonic hydrogen data. The calculations are performed using chiral SU(3) effective field theory in combination with non-perturbative schemes based on coupled channels. Several variants of such approaches are compared with experimental data and the differences in the results are discussed. Coulomb and isospin breaking effects turn out to be important and are both taken into account. The pole structure of the Lambda(1405) resonance close to the anti-kaon nucleon threshold is critically examined.
[ { "created": "Fri, 27 May 2005 14:52:54 GMT", "version": "v1" } ]
2011-05-05
[ [ "Borasoy", "B.", "" ], [ "Nissler", "R.", "" ], [ "Weise", "W.", "" ] ]
The anti-kaon nucleon system close to threshold is analyzed in view of the new accurate DEAR kaonic hydrogen data. The calculations are performed using chiral SU(3) effective field theory in combination with non-perturbative schemes based on coupled channels. Several variants of such approaches are compared with experimental data and the differences in the results are discussed. Coulomb and isospin breaking effects turn out to be important and are both taken into account. The pole structure of the Lambda(1405) resonance close to the anti-kaon nucleon threshold is critically examined.
2102.12541
Angel Salvador Miramontes L\'opez
\'Angel S. Miramontes L\'opez, H\`elios Sanchis-Alepuz and Reinhard Alkofer
Elucidating the effect of intermediate resonances in the quark interaction kernel on the time-like electromagnetic pion form factor
14 pages, 8 figures. References added
Phys. Rev. D 103, 116006 (2021)
10.1103/PhysRevD.103.116006
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
An exploratory study of the time-like pion electromagnetic form factor in a Poincar\'e-covariant bound state formalism in the isospin symmetric limit is presented. Starting from a quark interaction kernel representing gluon-intermediated interactions for valence-type quarks, non-valence effects are included by introducing pions as explicit degrees of freedom. The two most important qualitative aspects are, in view of the presented study, the opening of the dominant $\rho$-meson decay channel and the presence of a multi-particle branch cut setting in when the two-pion threshold is crossed. Based on a recent respective computation of the quark-photon vertex, the pion electromagnetic form factor for space-like and time-like kinematics is calculated. The obtained results for its absolute value and its phase compare favorably to the available experimental data, and they are analyzed in detail by confronting them to the expectations based on an isospin-symmetric version of a vector-meson dominance model.
[ { "created": "Wed, 24 Feb 2021 20:20:50 GMT", "version": "v1" }, { "created": "Tue, 23 Mar 2021 01:13:09 GMT", "version": "v2" } ]
2021-06-16
[ [ "López", "Ángel S. Miramontes", "" ], [ "Sanchis-Alepuz", "Hèlios", "" ], [ "Alkofer", "Reinhard", "" ] ]
An exploratory study of the time-like pion electromagnetic form factor in a Poincar\'e-covariant bound state formalism in the isospin symmetric limit is presented. Starting from a quark interaction kernel representing gluon-intermediated interactions for valence-type quarks, non-valence effects are included by introducing pions as explicit degrees of freedom. The two most important qualitative aspects are, in view of the presented study, the opening of the dominant $\rho$-meson decay channel and the presence of a multi-particle branch cut setting in when the two-pion threshold is crossed. Based on a recent respective computation of the quark-photon vertex, the pion electromagnetic form factor for space-like and time-like kinematics is calculated. The obtained results for its absolute value and its phase compare favorably to the available experimental data, and they are analyzed in detail by confronting them to the expectations based on an isospin-symmetric version of a vector-meson dominance model.
hep-ph/9506234
Levan Surguladze
I.M. Dremin
LARGE CORRELATIONS IN PARTICLE PRODUCTION AND SQUEEZING PHENOMENA
null
null
null
null
hep-ph
null
Recent developments in studies of multiparticle correlations in high energy particle collisions are reviewed. Both experimental data and theoretical results in quantum chromodynamics are discussed. Application of the developed methods to the coherent, squeezed and correlated states of photons is considered. Some speculations concerning possible coherent and squeezed states of pion fields as well as their specific features are described.
[ { "created": "Sun, 4 Jun 1995 20:01:38 GMT", "version": "v1" } ]
2007-05-23
[ [ "Dremin", "I. M.", "" ] ]
Recent developments in studies of multiparticle correlations in high energy particle collisions are reviewed. Both experimental data and theoretical results in quantum chromodynamics are discussed. Application of the developed methods to the coherent, squeezed and correlated states of photons is considered. Some speculations concerning possible coherent and squeezed states of pion fields as well as their specific features are described.