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1804.06824
Daniel Hulme
Sophia Borowka, Thomas Gehrmann, Daniel Hulme
Systematic approximation of multi-scale Feynman integrals
31 pages + refs , 34 figures. v2 reflects the version published in JHEP. The case of integrals with multiple thresholds has been added, with new plots and text
null
10.1007/JHEP08(2018)111
CERN-TH-2018-078, ZU-TH 14/18
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An algorithm for the systematic analytical approximation of multi-scale Feynman integrals is presented. The algorithm produces algebraic expressions as functions of the kinematical parameters and mass scales appearing in the Feynman integrals, allowing for fast numerical evaluation. The results are valid in all kinematical regions, both above and below thresholds, up to in principle arbitrary orders in the dimensional regulator. The scope of the algorithm is demonstrated by presenting results for selected two-loop three-point and four-point integrals with an internal mass scale that appear in the two-loop amplitudes for Higgs+jet production.
[ { "created": "Wed, 18 Apr 2018 17:22:36 GMT", "version": "v1" }, { "created": "Fri, 7 Sep 2018 08:43:29 GMT", "version": "v2" } ]
2018-09-26
[ [ "Borowka", "Sophia", "" ], [ "Gehrmann", "Thomas", "" ], [ "Hulme", "Daniel", "" ] ]
An algorithm for the systematic analytical approximation of multi-scale Feynman integrals is presented. The algorithm produces algebraic expressions as functions of the kinematical parameters and mass scales appearing in the Feynman integrals, allowing for fast numerical evaluation. The results are valid in all kinematical regions, both above and below thresholds, up to in principle arbitrary orders in the dimensional regulator. The scope of the algorithm is demonstrated by presenting results for selected two-loop three-point and four-point integrals with an internal mass scale that appear in the two-loop amplitudes for Higgs+jet production.
1112.5497
Jeonghyeon Song
Sanghyeon Chang, Kang Young Lee, and Jeonghyeon Song (Konkuk Univ., Korea)
Probing axino LSP from diphotons events with large missing transverse energy
to be appeared in Phys. Lett. B. 10 pages with 2 figure
null
10.1016/j.physletb.2012.09.009
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a supersymmetry model with an axino as the lightest supersymmetric particle (LSP) and a Bino as the next LSP (NLSP), supersymmetry particles produced in pair at a high energy collider end up with including two Binos, followed by each Bino's decay into a photon and an axino. Final states are diphoton with large missing energy. We have comprehensively studied the implication of $\gamma\gamma+$MET data from the ALEPH, CDF II, and recent ATLAS and CMS experiments. No excess over the standard model backgrounds can be explained in this model if the NLSP Bino decays outside the detector, which happens when the axino decay constant $f_a$ is large enough. The ALEPH and CDF II data put a very strong bound on $f_a$ for light Bino case with $m_{\tilde{B}} < 150$ GeV: the narrow hadronic axion window around $f_a \sim 10^6$ GeV is completely closed. In the case where the gluino mass is smaller than about 776 GeV, the recent ATLAS data limit $f_a > 10^5$ GeV for the Bino mass below 700 GeV. This is already stronger than the previous laboratory bounds.
[ { "created": "Fri, 23 Dec 2011 01:04:35 GMT", "version": "v1" }, { "created": "Mon, 16 Jul 2012 08:46:22 GMT", "version": "v2" } ]
2015-06-03
[ [ "Chang", "Sanghyeon", "", "Konkuk Univ.,\n Korea" ], [ "Lee", "Kang Young", "", "Konkuk Univ.,\n Korea" ], [ "Song", "Jeonghyeon", "", "Konkuk Univ.,\n Korea" ] ]
In a supersymmetry model with an axino as the lightest supersymmetric particle (LSP) and a Bino as the next LSP (NLSP), supersymmetry particles produced in pair at a high energy collider end up with including two Binos, followed by each Bino's decay into a photon and an axino. Final states are diphoton with large missing energy. We have comprehensively studied the implication of $\gamma\gamma+$MET data from the ALEPH, CDF II, and recent ATLAS and CMS experiments. No excess over the standard model backgrounds can be explained in this model if the NLSP Bino decays outside the detector, which happens when the axino decay constant $f_a$ is large enough. The ALEPH and CDF II data put a very strong bound on $f_a$ for light Bino case with $m_{\tilde{B}} < 150$ GeV: the narrow hadronic axion window around $f_a \sim 10^6$ GeV is completely closed. In the case where the gluino mass is smaller than about 776 GeV, the recent ATLAS data limit $f_a > 10^5$ GeV for the Bino mass below 700 GeV. This is already stronger than the previous laboratory bounds.
1012.4687
Robi Peschanski
Andrzej Bialas (Krakow) and Robi Peschanski (Saclay)
Asymmetric 1+1-dimensional hydrodynamics in collision
10 pages, 4 (double) figures
Phys.Rev.C83:054905,2011
10.1103/PhysRevC.83.054905
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The possibility that particle production in high-energy collisions is a result of two asymmetric hydrodynamic flows is investigated, using the Khalatnikov form of the 1+1-dimensional approximation of hydrodynamic equations. The general solution is discussed and applied to the physically appealing "generalized in-out cascade" where the space-time and energy-momentum rapidities are equal at initial temperature but boost-invariance is not imposed. It is demonstrated that the two-bump structure of the entropy density, characteristic of the asymmetric input, changes easily into a single broad maximum compatible with data on particle production in symmetric processes. A possible microscopic QCD interpretation of asymmetric hydrodynamics is proposed.
[ { "created": "Tue, 21 Dec 2010 15:14:48 GMT", "version": "v1" } ]
2011-05-19
[ [ "Bialas", "Andrzej", "", "Krakow" ], [ "Peschanski", "Robi", "", "Saclay" ] ]
The possibility that particle production in high-energy collisions is a result of two asymmetric hydrodynamic flows is investigated, using the Khalatnikov form of the 1+1-dimensional approximation of hydrodynamic equations. The general solution is discussed and applied to the physically appealing "generalized in-out cascade" where the space-time and energy-momentum rapidities are equal at initial temperature but boost-invariance is not imposed. It is demonstrated that the two-bump structure of the entropy density, characteristic of the asymmetric input, changes easily into a single broad maximum compatible with data on particle production in symmetric processes. A possible microscopic QCD interpretation of asymmetric hydrodynamics is proposed.
hep-ph/9404328
Dam Than Son
V.A.Rubakov and O.Yu.Shvedov
Sphalerons and Large Order Behavior of Perturbation Theory in Lower Dimension
23 pages, 9 figures, LaTeX, preprint INR-850/94
Nucl.Phys. B434 (1995) 245-263
10.1016/0550-3213(94)00447-M
null
hep-ph
null
Sphalerons -- unstable static solutions of classical field equations in (d+1)-dimensional space-time -- may be viewed as euclidean solutions in d dimensions. We discuss their role in the large order asymptotics of the perturbation theory. Specifically, we calculate their contribution to the large order behaviour of the ground state energy in a quantum mechanical model. When the number of negative modes is odd, single sphaleron contribution dominates, while this contribution vanishes when the number of negative modes is even. These results are confirmed by numerical calculations.
[ { "created": "Fri, 22 Apr 1994 15:47:32 GMT", "version": "v1" }, { "created": "Mon, 25 Apr 1994 07:44:49 GMT", "version": "v2" } ]
2009-10-28
[ [ "Rubakov", "V. A.", "" ], [ "Shvedov", "O. Yu.", "" ] ]
Sphalerons -- unstable static solutions of classical field equations in (d+1)-dimensional space-time -- may be viewed as euclidean solutions in d dimensions. We discuss their role in the large order asymptotics of the perturbation theory. Specifically, we calculate their contribution to the large order behaviour of the ground state energy in a quantum mechanical model. When the number of negative modes is odd, single sphaleron contribution dominates, while this contribution vanishes when the number of negative modes is even. These results are confirmed by numerical calculations.
1702.07220
Luis Roca
L. Roca, E. Oset
Role of a triangle singularity in the $\pi \Delta$ decay of the $N(1700)(3/2^-)$
8 pages, 6 figures
Phys. Rev. C 95, 065211 (2017)
10.1103/PhysRevC.95.065211
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show the important role played by the $\pi\Delta(1232)$ channel in the build up of the $N(1700)(3/2^-)$ resonance due to the non-trivial enhancement produced by a singularity of a triangular loop. The $N(1700)$ is one of the dynamically generated resonances produced by the coupled channel vector-baryon interaction. The $\pi\Delta$ channel was neglected in previous works but we show that it has to be incorporated into the coupled channel formalism due to an enhancement produced by a singularity in the triangular loop with $\rho$, nucleon and $\pi$ as internal loop lines and $\pi$ and $\Delta$ as external ones. The enhancement is of non-resonant origin but it contributes to the dynamical generation of the $N(1700)$ resonance due to the non-linear dynamics involved in the coupled channel mechanisms. We obtain an important increase of the total width of the $N(1700)$ resonance when the $\pi\Delta$ channel is included and provide predictions for the partial widths of the $N(1700)$ decays into $VB$ and $\pi\Delta$.
[ { "created": "Thu, 23 Feb 2017 14:05:32 GMT", "version": "v1" } ]
2017-06-28
[ [ "Roca", "L.", "" ], [ "Oset", "E.", "" ] ]
We show the important role played by the $\pi\Delta(1232)$ channel in the build up of the $N(1700)(3/2^-)$ resonance due to the non-trivial enhancement produced by a singularity of a triangular loop. The $N(1700)$ is one of the dynamically generated resonances produced by the coupled channel vector-baryon interaction. The $\pi\Delta$ channel was neglected in previous works but we show that it has to be incorporated into the coupled channel formalism due to an enhancement produced by a singularity in the triangular loop with $\rho$, nucleon and $\pi$ as internal loop lines and $\pi$ and $\Delta$ as external ones. The enhancement is of non-resonant origin but it contributes to the dynamical generation of the $N(1700)$ resonance due to the non-linear dynamics involved in the coupled channel mechanisms. We obtain an important increase of the total width of the $N(1700)$ resonance when the $\pi\Delta$ channel is included and provide predictions for the partial widths of the $N(1700)$ decays into $VB$ and $\pi\Delta$.
hep-ph/9911369
Alexey A. Petrov
Adam F. Falk, Yosef Nir, and Alexey A. Petrov
Strong phases and D0-anti-D0 mixing parameters
9 pages, 1 figure, RevTeX; discussion clarified, qualitative and quantitative conclusions unchanged, version to appear in JHEP
JHEP 9912 (1999) 019
10.1088/1126-6708/1999/12/019
JHU-TIPAC-99010, IASSNS-HEP-99-104
hep-ph hep-ex
null
We argue that there could be large, SU(3) violating resonance contributions to D -> K pi decays which would affect the extraction of the D0-anti-D0 mixing parameters from experiment. Such contributions can induce a large strong phase in the interference between the doubly Cabibbo suppressed and the mixing induced Cabibbo favored contributions to the D0 -> K^+ pi^- and anti-D0 -> K^- pi^+ decays. Consequently, the interpretation of a large, CP conserving interference term can involve a large mass difference Delta M rather than a large width difference Delta Gamma.
[ { "created": "Mon, 15 Nov 1999 23:21:33 GMT", "version": "v1" }, { "created": "Mon, 20 Dec 1999 17:06:17 GMT", "version": "v2" } ]
2009-10-31
[ [ "Falk", "Adam F.", "" ], [ "Nir", "Yosef", "" ], [ "Petrov", "Alexey A.", "" ] ]
We argue that there could be large, SU(3) violating resonance contributions to D -> K pi decays which would affect the extraction of the D0-anti-D0 mixing parameters from experiment. Such contributions can induce a large strong phase in the interference between the doubly Cabibbo suppressed and the mixing induced Cabibbo favored contributions to the D0 -> K^+ pi^- and anti-D0 -> K^- pi^+ decays. Consequently, the interpretation of a large, CP conserving interference term can involve a large mass difference Delta M rather than a large width difference Delta Gamma.
hep-ph/9902283
Smaragda Lola
Smaragda Lola (CERN) and Graham G. Ross (Oxford U.)
Neutrino masses from U(1) symmetries and the Super-Kamiokande data
30 pages, 2 figures
Nucl.Phys. B553 (1999) 81-107
10.1016/S0550-3213(99)00150-9
CERN-TH/99-27, OUTP-99-11-P
hep-ph
null
Motivated by the Super-Kamiokande data, we revisit models with U(1) symmetries and discuss the origin of neutrino masses and mixings in such theories. We show that, in models with just three light neutrinos and a hierarchy of neutrino masses, large (2-3) mixing fixes the lepton doublet U(1) charges and is thus related to the structure of the charged lepton mass matrix. We discuss the fermion mass structure that follows from the Abelian family symmetry with an extended gauge group. Requiring that the quark and lepton masses be ordered by the family symmetry, we identify the most promising scheme. This requires large, but not necessarily maximal, mixing in the mu-tau sector and gives small e-mu mixing in the range that is required for the small angle solution of the solar neutrino deficit.
[ { "created": "Tue, 9 Feb 1999 17:22:00 GMT", "version": "v1" } ]
2009-10-31
[ [ "Lola", "Smaragda", "", "CERN" ], [ "Ross", "Graham G.", "", "Oxford U." ] ]
Motivated by the Super-Kamiokande data, we revisit models with U(1) symmetries and discuss the origin of neutrino masses and mixings in such theories. We show that, in models with just three light neutrinos and a hierarchy of neutrino masses, large (2-3) mixing fixes the lepton doublet U(1) charges and is thus related to the structure of the charged lepton mass matrix. We discuss the fermion mass structure that follows from the Abelian family symmetry with an extended gauge group. Requiring that the quark and lepton masses be ordered by the family symmetry, we identify the most promising scheme. This requires large, but not necessarily maximal, mixing in the mu-tau sector and gives small e-mu mixing in the range that is required for the small angle solution of the solar neutrino deficit.
1003.0196
Sergey Ostapchenko
Sergey Ostapchenko
Total and diffractive cross sections in enhanced Pomeron scheme
null
Phys.Rev.D81:114028,2010
10.1103/PhysRevD.81.114028
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
For the first time, a systematic analysis of the high energy behavior of total and diffractive proton-proton cross sections is performed within the Reggeon Field Theory framework, based on the resummation of all significant contributions of enhanced Pomeron diagrams to all orders with respect to the triple-Pomeron coupling. The importance of different classes of enhanced graphs is investigated and it is demonstrated that absorptive corrections due to "net"-like enhanced diagrams and due to Pomeron "loops" are both significant and none of those classes can be neglected at high energies. A comparison with other approaches based on partial resummations of enhanced diagrams is performed. In particular, important differences are found concerning the predicted high energy behavior of total and single high mass diffraction proton-proton cross sections, with our values of $\sigma_{pp}^{{\rm tot}}$ at $\sqrt{s}=14$ TeV being some $25\div40$% higher and with the energy rise of $\sigma_{{\rm HM}}^{{\rm SD}}$ saturating well below the LHC energy. The main causes for those differences are analyzed and explained.
[ { "created": "Mon, 1 Mar 2010 16:22:29 GMT", "version": "v1" } ]
2014-11-20
[ [ "Ostapchenko", "Sergey", "" ] ]
For the first time, a systematic analysis of the high energy behavior of total and diffractive proton-proton cross sections is performed within the Reggeon Field Theory framework, based on the resummation of all significant contributions of enhanced Pomeron diagrams to all orders with respect to the triple-Pomeron coupling. The importance of different classes of enhanced graphs is investigated and it is demonstrated that absorptive corrections due to "net"-like enhanced diagrams and due to Pomeron "loops" are both significant and none of those classes can be neglected at high energies. A comparison with other approaches based on partial resummations of enhanced diagrams is performed. In particular, important differences are found concerning the predicted high energy behavior of total and single high mass diffraction proton-proton cross sections, with our values of $\sigma_{pp}^{{\rm tot}}$ at $\sqrt{s}=14$ TeV being some $25\div40$% higher and with the energy rise of $\sigma_{{\rm HM}}^{{\rm SD}}$ saturating well below the LHC energy. The main causes for those differences are analyzed and explained.
hep-ph/9503349
Klaus Kinder-Geiger
John Ellis and Klaus Geiger
REAL-TIME DESCRIPTION OF PARTON-HADRON CONVERSION AND CONFINEMENT DYNAMICS
51 pages, latex, 14 figures as uu-encoded postscript file.
Phys.Rev.D52:1500-1526,1995
10.1103/PhysRevD.52.1500
CERN-TH. 35-95
hep-ph nucl-th
null
We propose a new and universal approach to the hadronization problem that incorporates both partonic and hadronic degrees of freedom in their respective domains of relevance, and that describes the conversion between them within a kinetic field theory formulation in real time and full 7-dimensional phase space. We construct a scale-dependent effective theory that reduces to perturbative QCD with its scale and chiral symmetry properties at short space-time distances, but at large distances (r > 1 fm) yields symmetry breaking gluon and quark condensates plus hadronic excitations. The approach is applied to the evolution of fragmenting qq~ and gg jet pairs as the system evolves from the initial 2-jet configuration, via parton showering and cluster formation, to the final yield of hadrons. The phenomenological implications for e+e- -> hadrons are investigated, such as the time scale of the transition, and its energy dependence, cluster size and mass distributions. We compare our results for particle production and Bose-Einstein correlations with experimental data, and find an interesting possibility of extracting the basic parameters of the space-time evolution of the system from Bose enhancement measurements.
[ { "created": "Thu, 16 Mar 1995 15:25:14 GMT", "version": "v1" } ]
2016-09-01
[ [ "Ellis", "John", "" ], [ "Geiger", "Klaus", "" ] ]
We propose a new and universal approach to the hadronization problem that incorporates both partonic and hadronic degrees of freedom in their respective domains of relevance, and that describes the conversion between them within a kinetic field theory formulation in real time and full 7-dimensional phase space. We construct a scale-dependent effective theory that reduces to perturbative QCD with its scale and chiral symmetry properties at short space-time distances, but at large distances (r > 1 fm) yields symmetry breaking gluon and quark condensates plus hadronic excitations. The approach is applied to the evolution of fragmenting qq~ and gg jet pairs as the system evolves from the initial 2-jet configuration, via parton showering and cluster formation, to the final yield of hadrons. The phenomenological implications for e+e- -> hadrons are investigated, such as the time scale of the transition, and its energy dependence, cluster size and mass distributions. We compare our results for particle production and Bose-Einstein correlations with experimental data, and find an interesting possibility of extracting the basic parameters of the space-time evolution of the system from Bose enhancement measurements.
1510.03654
Maxim Mai
Maxim Mai
Constraints on the chiral unitary $\bar KN$ amplitude from ${\pi}{\Sigma}K^+$ photoproduction data
8 pages, to appear in PoS of Chiral Dynamics, Pisa, Italy, 2015
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A chiral unitary approach for antikaon-nucleon scattering in on-shell factorization is studied. We find multiple sets of parameters for which the model describes all existing hadronic data similarly well. We confirm the two-pole structure of the ${\Lambda}(1405)$. The narrow ${\Lambda}(1405)$ pole appears at comparable positions in the complex energy plane, whereas the location of the broad pole suffers from a large uncertainty. In the second step, we use a simple model for photoproduction of $K^+{\pi}{\Sigma}$ off the proton and confront it with the experimental data from the CLAS collaboration. It is found that only a few of the hadronic solutions allow for a consistent description of the CLAS data within the assumed reaction mechanism.
[ { "created": "Tue, 13 Oct 2015 13:03:47 GMT", "version": "v1" } ]
2015-10-14
[ [ "Mai", "Maxim", "" ] ]
A chiral unitary approach for antikaon-nucleon scattering in on-shell factorization is studied. We find multiple sets of parameters for which the model describes all existing hadronic data similarly well. We confirm the two-pole structure of the ${\Lambda}(1405)$. The narrow ${\Lambda}(1405)$ pole appears at comparable positions in the complex energy plane, whereas the location of the broad pole suffers from a large uncertainty. In the second step, we use a simple model for photoproduction of $K^+{\pi}{\Sigma}$ off the proton and confront it with the experimental data from the CLAS collaboration. It is found that only a few of the hadronic solutions allow for a consistent description of the CLAS data within the assumed reaction mechanism.
1004.4187
Geraldine Servant
Jose R. Espinosa, Thomas Konstandin, Jose M. No and Geraldine Servant
Energy Budget of Cosmological First-order Phase Transitions
36 pages, 14 figures
JCAP 1006:028,2010
10.1088/1475-7516/2010/06/028
CERN-PH-TH/2010-027
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The study of the hydrodynamics of bubble growth in first-order phase transitions is very relevant for electroweak baryogenesis, as the baryon asymmetry depends sensitively on the bubble wall velocity, and also for predicting the size of the gravity wave signal resulting from bubble collisions, which depends on both the bubble wall velocity and the plasma fluid velocity. We perform such study in different bubble expansion regimes, namely deflagrations, detonations, hybrids (steady states) and runaway solutions (accelerating wall), without relying on a specific particle physics model. We compute the efficiency of the transfer of vacuum energy to the bubble wall and the plasma in all regimes. We clarify the condition determining the runaway regime and stress that in most models of strong first-order phase transitions this will modify expectations for the gravity wave signal. Indeed, in this case, most of the kinetic energy is concentrated in the wall and almost no turbulent fluid motions are expected since the surrounding fluid is kept mostly at rest.
[ { "created": "Fri, 23 Apr 2010 17:30:24 GMT", "version": "v1" } ]
2014-11-20
[ [ "Espinosa", "Jose R.", "" ], [ "Konstandin", "Thomas", "" ], [ "No", "Jose M.", "" ], [ "Servant", "Geraldine", "" ] ]
The study of the hydrodynamics of bubble growth in first-order phase transitions is very relevant for electroweak baryogenesis, as the baryon asymmetry depends sensitively on the bubble wall velocity, and also for predicting the size of the gravity wave signal resulting from bubble collisions, which depends on both the bubble wall velocity and the plasma fluid velocity. We perform such study in different bubble expansion regimes, namely deflagrations, detonations, hybrids (steady states) and runaway solutions (accelerating wall), without relying on a specific particle physics model. We compute the efficiency of the transfer of vacuum energy to the bubble wall and the plasma in all regimes. We clarify the condition determining the runaway regime and stress that in most models of strong first-order phase transitions this will modify expectations for the gravity wave signal. Indeed, in this case, most of the kinetic energy is concentrated in the wall and almost no turbulent fluid motions are expected since the surrounding fluid is kept mostly at rest.
0710.3125
Sukanta Panda
Sukanta Panda and Sergei I. Sinegovsky
High-energy Atmospheric Muon Flux Expected at India-Based Neutrino Observatory
10 pages. 8 figures, 3 tables
Int.J.Mod.Phys.A23:2933-2942,2008
10.1142/S0217751X08041268
null
hep-ph
null
We calculate the zenith-angle dependence of conventional and prompt high-energy muon fluxes at India-Based Neutrino Observatory (INO) depth. This study demonstrates a possibility to discriminate models of the charm hadroproduction including the low-x QCD behaviour of hadronic cross-sections relevant at very high energies.
[ { "created": "Tue, 16 Oct 2007 16:55:56 GMT", "version": "v1" }, { "created": "Mon, 4 Feb 2008 13:44:52 GMT", "version": "v2" } ]
2008-11-26
[ [ "Panda", "Sukanta", "" ], [ "Sinegovsky", "Sergei I.", "" ] ]
We calculate the zenith-angle dependence of conventional and prompt high-energy muon fluxes at India-Based Neutrino Observatory (INO) depth. This study demonstrates a possibility to discriminate models of the charm hadroproduction including the low-x QCD behaviour of hadronic cross-sections relevant at very high energies.
2310.03909
Manoranjan Dutta
Manoranjan Dutta (North Lakhimpur College (Autonomous))
Self-interacting Dark Matter in Non-Standard Cosmology
11 pages, 11 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Discrepancies of the $\Lambda {\rm CDM}$ model with small-scale cosmological observations and stringent constraints from direct search experiments cast doubts over typical weak scale cold dark matter candidates e.g. WIMPs. Self-interacting dark matter (SIDM) is a very promising alternative to WIMP, which not only alleviates the small-scale anomalies of the $\Lambda {\rm CDM}$ model, but also matches with the highly accurate large-scale $\Lambda {\rm CDM}$ predictions. The small-scale anomalies can be resolved with a self-scattering cross-section $\sigma/m_{DM} \sim 1 cm^2/gm$. Such large cross-sections can be realised in models of DM with a light MeV scale mediator and a sizeable coupling. We assume the DM to be Dirac fermion and the mediator to be either a light scalar or vector boson. In a standard cosmological history, one major issue with such models is to realise the correct relic density of dark matter via thermal freeze-out as the DM annihilates efficiently to the light mediators and ends up with an under-abundant relic. However, we show that, if the expansion rate of the universe is not radiation-dominated (RD) during the epoch of SIDM freeze-out, its relic abundance is enhanced significantly. We assume a non-standard expansion history of the universe by introducing a non-radiation like component in the early universe. In such a scenario, DM freezes out at an earlier epoch resulting in enhanced DM abundance, which can be matched with the correct relic density with suitable model parameters. The light mediator can also couple to an SM mediator and pave a way to detect SIDM at terrestrial laboratories. The mixing between the mediators can be constrained by data from direct search experiments. We find out the viable parameter space for a generic SIDM model taking into account the relevant phenomenological and experimental constraints.
[ { "created": "Thu, 5 Oct 2023 21:29:51 GMT", "version": "v1" } ]
2023-10-09
[ [ "Dutta", "Manoranjan", "", "North Lakhimpur College" ] ]
Discrepancies of the $\Lambda {\rm CDM}$ model with small-scale cosmological observations and stringent constraints from direct search experiments cast doubts over typical weak scale cold dark matter candidates e.g. WIMPs. Self-interacting dark matter (SIDM) is a very promising alternative to WIMP, which not only alleviates the small-scale anomalies of the $\Lambda {\rm CDM}$ model, but also matches with the highly accurate large-scale $\Lambda {\rm CDM}$ predictions. The small-scale anomalies can be resolved with a self-scattering cross-section $\sigma/m_{DM} \sim 1 cm^2/gm$. Such large cross-sections can be realised in models of DM with a light MeV scale mediator and a sizeable coupling. We assume the DM to be Dirac fermion and the mediator to be either a light scalar or vector boson. In a standard cosmological history, one major issue with such models is to realise the correct relic density of dark matter via thermal freeze-out as the DM annihilates efficiently to the light mediators and ends up with an under-abundant relic. However, we show that, if the expansion rate of the universe is not radiation-dominated (RD) during the epoch of SIDM freeze-out, its relic abundance is enhanced significantly. We assume a non-standard expansion history of the universe by introducing a non-radiation like component in the early universe. In such a scenario, DM freezes out at an earlier epoch resulting in enhanced DM abundance, which can be matched with the correct relic density with suitable model parameters. The light mediator can also couple to an SM mediator and pave a way to detect SIDM at terrestrial laboratories. The mixing between the mediators can be constrained by data from direct search experiments. We find out the viable parameter space for a generic SIDM model taking into account the relevant phenomenological and experimental constraints.
1305.5152
Chong Sheng Li
Yong Chuan Zhan, Ze Long Liu, Shi Ang Li, Chong Sheng Li, Hai Tao Li
Threshold resummation for the production of a color sextet (antitriplet) scalar at the LHC
21 pages,9 figures,3 tables; Version published in EPJC
Eur. Phys. J. C (2014) 74:2716
10.1140/epjc/s10052-014-2716-7
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate threshold resummation effects in the production of a color sextet (antitriplet) scalar at next-to-next-to-leading logarithmic (NNLL) order at the LHC in the frame of soft-collinear effective theory. We show the total cross section and the rapidity distribution with NLO+NNLL accuracy, and we compare them with the NLO results. Besides, we use recent dijet data at the LHC to give the constraints on the couplings between the colored scalars and quarks.
[ { "created": "Wed, 22 May 2013 14:38:01 GMT", "version": "v1" }, { "created": "Mon, 3 Mar 2014 09:30:34 GMT", "version": "v2" } ]
2014-03-04
[ [ "Zhan", "Yong Chuan", "" ], [ "Liu", "Ze Long", "" ], [ "Li", "Shi Ang", "" ], [ "Li", "Chong Sheng", "" ], [ "Li", "Hai Tao", "" ] ]
We investigate threshold resummation effects in the production of a color sextet (antitriplet) scalar at next-to-next-to-leading logarithmic (NNLL) order at the LHC in the frame of soft-collinear effective theory. We show the total cross section and the rapidity distribution with NLO+NNLL accuracy, and we compare them with the NLO results. Besides, we use recent dijet data at the LHC to give the constraints on the couplings between the colored scalars and quarks.
hep-ph/9602427
Frank Witte
F.M.C. Witte
Symmetry Breaking and Collisions with $\sigma$-Mesons
7 pages, LaTeX, three figures available in Postscript from the Author at witte@hybrid.tphys.uni-heidelberg.de
null
null
null
hep-ph
null
In this brief report we adress spontaneous symmetry breaking in a finite-temperature scalar meson plasma. We calculate the in-medium averaged thermal $\sigma-\sigma$ scattering crossection and the related shear viscosity $\eta(T)$ and mean-free-path $L(T)$. Our results suggest that slightly below the critical temperature there is a 30 percent peak in the crossection leading to equivalent dips in $\eta(T)$ and $L(T)$. We discuss the relevance of this observation.
[ { "created": "Thu, 29 Feb 1996 08:13:09 GMT", "version": "v1" } ]
2007-05-23
[ [ "Witte", "F. M. C.", "" ] ]
In this brief report we adress spontaneous symmetry breaking in a finite-temperature scalar meson plasma. We calculate the in-medium averaged thermal $\sigma-\sigma$ scattering crossection and the related shear viscosity $\eta(T)$ and mean-free-path $L(T)$. Our results suggest that slightly below the critical temperature there is a 30 percent peak in the crossection leading to equivalent dips in $\eta(T)$ and $L(T)$. We discuss the relevance of this observation.
hep-ph/9802388
null
Z. Chacko and R. N. Mohapatra
Supersymmetric $SU(2)_L\times SU(2)_R \times SU(4)_c$ and observable neutron-antineutron oscillation
4 pages; one figure; Preprint No. UMD-PP-98-94
Phys.Rev. D59 (1999) 055004
10.1103/PhysRevD.59.055004
null
hep-ph
null
We show that in a large class of supersymmetric $SU(2)_L\times SU(2)_R\times SU(4)_c$ models with the see-saw mechanism for neutrino masses and an R-parity conserving vacuum, there are diquark Higgs bosons with masses ($M_{qq}$) near the weak scale even though the scale of $SU(2)_R\times SU(4)_c$ symmetry breaking is around $10^{10}$ GeV. This happens because these masses ($M_{qq}$) arise out of higher dimensional operators needed to stabilize the charge conserving vacuum in the model. This feature has the interesting implication that the $\Delta B=2$ processes such as neutron-anti-neutron oscillation can have observable rates while at the same time yielding neutrino masses in the range of current interest.
[ { "created": "Sat, 21 Feb 1998 16:46:11 GMT", "version": "v1" } ]
2009-10-31
[ [ "Chacko", "Z.", "" ], [ "Mohapatra", "R. N.", "" ] ]
We show that in a large class of supersymmetric $SU(2)_L\times SU(2)_R\times SU(4)_c$ models with the see-saw mechanism for neutrino masses and an R-parity conserving vacuum, there are diquark Higgs bosons with masses ($M_{qq}$) near the weak scale even though the scale of $SU(2)_R\times SU(4)_c$ symmetry breaking is around $10^{10}$ GeV. This happens because these masses ($M_{qq}$) arise out of higher dimensional operators needed to stabilize the charge conserving vacuum in the model. This feature has the interesting implication that the $\Delta B=2$ processes such as neutron-anti-neutron oscillation can have observable rates while at the same time yielding neutrino masses in the range of current interest.
1305.2850
Luca Di Luzio
Luca Di Luzio and Luminita Mihaila
Unification scale vs. electroweak-triplet mass in the SU(5) + 24_F model at three loops
16 pages, 7 figures. One reference added. To appear in Phys. Rev. D
null
10.1103/PhysRevD.87.115025
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It was shown recently that the original SU(5) theory of Georgi and Glashow, augmented with an adjoint fermionic multiplet 24_F, can be made compatible both with neutrino masses and gauge coupling unification. In particular, the model predicts that either electroweak-triplet states are light, within the reach of the Large Hadron Collider (LHC), or proton decay will become accessible at the next generation of megaton-scale facilities. In this paper, we present the computation of the correlation function between the electroweak-triplet masses and the unification scale at the next-to-next-to-leading-order (NNLO). Such an accuracy on the theory side is necessary in order to settle the convergence of the perturbative expansion and to match the experimental precision on the determination of the electroweak gauge couplings at the Z-boson mass scale.
[ { "created": "Mon, 13 May 2013 17:15:17 GMT", "version": "v1" }, { "created": "Fri, 21 Jun 2013 08:49:06 GMT", "version": "v2" } ]
2013-08-09
[ [ "Di Luzio", "Luca", "" ], [ "Mihaila", "Luminita", "" ] ]
It was shown recently that the original SU(5) theory of Georgi and Glashow, augmented with an adjoint fermionic multiplet 24_F, can be made compatible both with neutrino masses and gauge coupling unification. In particular, the model predicts that either electroweak-triplet states are light, within the reach of the Large Hadron Collider (LHC), or proton decay will become accessible at the next generation of megaton-scale facilities. In this paper, we present the computation of the correlation function between the electroweak-triplet masses and the unification scale at the next-to-next-to-leading-order (NNLO). Such an accuracy on the theory side is necessary in order to settle the convergence of the perturbative expansion and to match the experimental precision on the determination of the electroweak gauge couplings at the Z-boson mass scale.
1809.04974
Francesco Giacosa
Francesco Giacosa
Chiral anomaly and strange-nonstrange mixing
4 pages. Prepared for the proceedings of MESON 2018, 15th International Workshop on Meson Physics, KRAK\'OW, POLAND, 7th - 12th June 2018
null
10.1051/epjconf/201919905012
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
As a first step, a simple and pedagogical recall of the $\eta$-$\eta'$ system is presented, in which the role of the axial anomaly, related to the heterochiral nature of the multiplet of (pseudo)scalar states, is underlined. As a consequence, $\eta$ is close to the octet and $\eta'$ to the singlet configuration. On the contrary, for vector and tensor states, which belong to homochiral multiplets, no anomalous contribution to masses and mixing is present. Then, the isoscalar physical states are to a very good approximation nonstrange and strange, respectively. Finally, for pseudotensor states, which are part of an heterochiral multiplet (just as pseudoscalar ones), a sizable anomalous term is expected: $\eta_2 (1645)$ roughly corresponds to the octet and $\eta_2 (1870)$ to the singlet.
[ { "created": "Thu, 13 Sep 2018 14:03:21 GMT", "version": "v1" }, { "created": "Mon, 29 Oct 2018 21:26:45 GMT", "version": "v2" } ]
2019-02-20
[ [ "Giacosa", "Francesco", "" ] ]
As a first step, a simple and pedagogical recall of the $\eta$-$\eta'$ system is presented, in which the role of the axial anomaly, related to the heterochiral nature of the multiplet of (pseudo)scalar states, is underlined. As a consequence, $\eta$ is close to the octet and $\eta'$ to the singlet configuration. On the contrary, for vector and tensor states, which belong to homochiral multiplets, no anomalous contribution to masses and mixing is present. Then, the isoscalar physical states are to a very good approximation nonstrange and strange, respectively. Finally, for pseudotensor states, which are part of an heterochiral multiplet (just as pseudoscalar ones), a sizable anomalous term is expected: $\eta_2 (1645)$ roughly corresponds to the octet and $\eta_2 (1870)$ to the singlet.
1312.5720
Marco Tonini
Lucian A. Harland-Lang, Chun-Hay Kom, Kazuki Sakurai, Marco Tonini
Sharpening $m_{T2}$ cusps: the mass determination of semi-invisibly decaying particles from a resonance
18 pages, 13 figures, version 2 updated to JHEP 06 (2014) 175
JHEP 06 (2014) 175
10.1007/JHEP06(2014)175
IPPP/13/103, DCPT/13/206, KCL-PH-TH/2013-48, LCTS/1014-09, DESY-13-258
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We revisit mass determination techniques for the minimum symmetric event topology, namely $X$ pair production followed by $X \to \ell N$, where $X$ and $N$ are unknown particles with the masses to be measured, and $N$ is an invisible particle, concentrating on the case where $X$ is pair produced from a resonance. We consider separate scenarios, with different initial constraints on the invisible particle momenta, and present a systematic method to identify the kinematically allowed mass regions in the $(m_N, m_X)$ plane. These allowed regions exhibit a cusp structure at the true mass point, which is equivalent to the one observed in the $m_{T2}$ endpoints in certain cases. By considering the boundary of the allowed mass region we systematically define kinematical variables which can be used in measuring the unknown masses, and find a new expression for the $m_{T2}$ variable as well as its inverse. We explicitly apply our method to the case that $X$ is pair produced from a resonance, and as a case study, we consider the process $pp \to A \to \tilde \chi_1^+ \tilde \chi_1^-$, followed by $\tilde \chi_1^\pm \to \ell^{\pm} \, \tilde \nu_{\ell}$, in the Minimal Supersymmetric Standard Model and show that our method provides a precise measurement of the chargino and sneutrino masses, $m_X$ and $m_N$, at $14 \, \mathrm{TeV}$ LHC with $300 \, \mathrm{fb}^{-1}$ luminosity.
[ { "created": "Thu, 19 Dec 2013 20:08:34 GMT", "version": "v1" }, { "created": "Tue, 8 Jul 2014 11:58:49 GMT", "version": "v2" } ]
2014-07-09
[ [ "Harland-Lang", "Lucian A.", "" ], [ "Kom", "Chun-Hay", "" ], [ "Sakurai", "Kazuki", "" ], [ "Tonini", "Marco", "" ] ]
We revisit mass determination techniques for the minimum symmetric event topology, namely $X$ pair production followed by $X \to \ell N$, where $X$ and $N$ are unknown particles with the masses to be measured, and $N$ is an invisible particle, concentrating on the case where $X$ is pair produced from a resonance. We consider separate scenarios, with different initial constraints on the invisible particle momenta, and present a systematic method to identify the kinematically allowed mass regions in the $(m_N, m_X)$ plane. These allowed regions exhibit a cusp structure at the true mass point, which is equivalent to the one observed in the $m_{T2}$ endpoints in certain cases. By considering the boundary of the allowed mass region we systematically define kinematical variables which can be used in measuring the unknown masses, and find a new expression for the $m_{T2}$ variable as well as its inverse. We explicitly apply our method to the case that $X$ is pair produced from a resonance, and as a case study, we consider the process $pp \to A \to \tilde \chi_1^+ \tilde \chi_1^-$, followed by $\tilde \chi_1^\pm \to \ell^{\pm} \, \tilde \nu_{\ell}$, in the Minimal Supersymmetric Standard Model and show that our method provides a precise measurement of the chargino and sneutrino masses, $m_X$ and $m_N$, at $14 \, \mathrm{TeV}$ LHC with $300 \, \mathrm{fb}^{-1}$ luminosity.
0810.1892
Kazunori Nakayama
Junji Hisano, Masahiro Kawasaki, Kazunori Kohri, Kazunori Nakayama
Positron/Gamma-Ray Signatures of Dark Matter Annihilation and Big-Bang Nucleosynthesis
5 pages, 4 figures; added references and discussion; included PAMELA data; to appear in PRD; corrected the electromagnetic-emission part, which does not change our conclusion (v4)
Phys.Rev.D79:063514,2009; Erratum-ibid.D80:029907,2009
10.1103/PhysRevD.79.063514 10.1103/PhysRevD.80.029907
ICRR-Report-531, IPMU 08-0077
hep-ph astro-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The positron excess observed by the PAMELA experiment may come from dark matter annihilation, if the annihilation cross section is large enough. We show that the dark matter annihilation scenarios to explain the positron excess may also be compatible with the discrepancy of the cosmic lithium abundances between theory and observations. The wino-like neutralino in the supersymmetric standard model is a good example for it. This scenario may be confirmed by Fermi satellite experiment.
[ { "created": "Fri, 10 Oct 2008 14:56:50 GMT", "version": "v1" }, { "created": "Fri, 16 Jan 2009 08:51:04 GMT", "version": "v2" }, { "created": "Tue, 3 Mar 2009 18:57:01 GMT", "version": "v3" }, { "created": "Mon, 29 Jun 2009 10:15:54 GMT", "version": "v4" } ]
2014-11-18
[ [ "Hisano", "Junji", "" ], [ "Kawasaki", "Masahiro", "" ], [ "Kohri", "Kazunori", "" ], [ "Nakayama", "Kazunori", "" ] ]
The positron excess observed by the PAMELA experiment may come from dark matter annihilation, if the annihilation cross section is large enough. We show that the dark matter annihilation scenarios to explain the positron excess may also be compatible with the discrepancy of the cosmic lithium abundances between theory and observations. The wino-like neutralino in the supersymmetric standard model is a good example for it. This scenario may be confirmed by Fermi satellite experiment.
hep-ph/9503293
Ramon Toldra. Ifae
E. Masso and R. Toldra
On a Light Spinless Particle Coupled to Photons
LaTex, 20p., 6 figures. Changes in sections 4, 5 and figure 2, our bounds are now more stringent. To be published in Physical Review D
Phys.Rev.D52:1755-1763,1995
10.1103/PhysRevD.52.1755
UAB-FT-361
hep-ph astro-ph
null
A pseudoscalar or scalar particle $\phi$ that couples to two photons but not to leptons, quarks and nucleons would have effects in most of the experiments searching for axions, since these are based on the $a \gamma \gamma $ coupling. We examine the laboratory, astrophysical and cosmological constraints on $\phi$ and study whether it may constitute a substantial part of the dark matter. We also generalize the $\phi$ interactions to possess $SU(2) \times U(1)$ gauge invariance, and analyze the phenomenological implications.
[ { "created": "Fri, 10 Mar 1995 17:43:46 GMT", "version": "v1" }, { "created": "Mon, 13 Mar 1995 10:01:46 GMT", "version": "v2" }, { "created": "Wed, 7 Jun 1995 15:51:09 GMT", "version": "v3" } ]
2009-09-25
[ [ "Masso", "E.", "" ], [ "Toldra", "R.", "" ] ]
A pseudoscalar or scalar particle $\phi$ that couples to two photons but not to leptons, quarks and nucleons would have effects in most of the experiments searching for axions, since these are based on the $a \gamma \gamma $ coupling. We examine the laboratory, astrophysical and cosmological constraints on $\phi$ and study whether it may constitute a substantial part of the dark matter. We also generalize the $\phi$ interactions to possess $SU(2) \times U(1)$ gauge invariance, and analyze the phenomenological implications.
hep-ph/0311065
Stefano Laporta
S. Laporta (Univ. of Parma and INFN-Bologna)
Calculation of Feynman integrals by difference equations
LaTex, 10 pages, uses appolb.cls. Presented at the XXVII International Conference of Theoretical Physics "Matter to the Deepest", Ustron, Poland, 15-21 September 2003. To appear in Acta Physica Polonica. v2:added references
Acta Phys.Polon. B34 (2003) 5323-5334
null
null
hep-ph
null
In this paper we describe a method of calculation of master integrals based on the solution of systems of difference equations in one variable. Various explicit examples are given, as well as the generalization to arbitrary diagrams.
[ { "created": "Wed, 5 Nov 2003 18:05:52 GMT", "version": "v1" }, { "created": "Fri, 7 Nov 2003 14:20:20 GMT", "version": "v2" } ]
2007-05-23
[ [ "Laporta", "S.", "", "Univ. of Parma and INFN-Bologna" ] ]
In this paper we describe a method of calculation of master integrals based on the solution of systems of difference equations in one variable. Various explicit examples are given, as well as the generalization to arbitrary diagrams.
1707.08060
Joan Elias-Miro
A. Azatov, J. Elias-Miro, Y. Reyimuaji, E. Venturini
Novel measurements of anomalous triple gauge couplings for the LHC
26 p
null
10.1007/JHEP10(2017)027
SISSA 35/2017/FISI
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Finding better ways to prove the Standard Model Effective Field Theory is a very important direction of research. This paper focuses on measurements of Electroweak triple gauge couplings, paying special attention on the regime of validity of the Effective Field Theory (EFT). In this regard, one of our goals is to find measurements leading to a large increase of the interference between the SM amplitude and the contribution of irrelevant operators in the EFT. We propose two such distributions that will lead to a better accuracy. Improvements compared to the traditional methods as well as LHC high luminosity prospects are discussed.
[ { "created": "Tue, 25 Jul 2017 16:01:27 GMT", "version": "v1" } ]
2017-10-25
[ [ "Azatov", "A.", "" ], [ "Elias-Miro", "J.", "" ], [ "Reyimuaji", "Y.", "" ], [ "Venturini", "E.", "" ] ]
Finding better ways to prove the Standard Model Effective Field Theory is a very important direction of research. This paper focuses on measurements of Electroweak triple gauge couplings, paying special attention on the regime of validity of the Effective Field Theory (EFT). In this regard, one of our goals is to find measurements leading to a large increase of the interference between the SM amplitude and the contribution of irrelevant operators in the EFT. We propose two such distributions that will lead to a better accuracy. Improvements compared to the traditional methods as well as LHC high luminosity prospects are discussed.
hep-ph/0303169
A. B. Balantekin
A.B. Balantekin, H. Yuksel (Wisconsin U., Madison)
Do the KamLAND and Solar Neutrino Data Rule out Solar Density Fluctuations?
7 pages of double-column REVTEX4 with 7 figures
Phys.Rev. D68 (2003) 013006
10.1103/PhysRevD.68.013006
null
hep-ph
null
We elucidate effects of solar density fluctuations on neutrino propagation through the Sun. Using data from the recent solar neutrino and KamLAND experiments we provide stringent limits on solar density fluctuations. It is shown that the neutrino data constrains solar density fluctuations to be less than beta = 0.05 at the 70 % confidence level, where beta is the fractional fluctuation around the value given by the Standard Solar Model. We find that the best fit to the combined solar neutrino and KamLAND data is given by beta = 0.
[ { "created": "Wed, 19 Mar 2003 21:15:33 GMT", "version": "v1" } ]
2009-11-10
[ [ "Balantekin", "A. B.", "", "Wisconsin U., Madison" ], [ "Yuksel", "H.", "", "Wisconsin U., Madison" ] ]
We elucidate effects of solar density fluctuations on neutrino propagation through the Sun. Using data from the recent solar neutrino and KamLAND experiments we provide stringent limits on solar density fluctuations. It is shown that the neutrino data constrains solar density fluctuations to be less than beta = 0.05 at the 70 % confidence level, where beta is the fractional fluctuation around the value given by the Standard Solar Model. We find that the best fit to the combined solar neutrino and KamLAND data is given by beta = 0.
2208.06926
Taygun Bulmus
T. Bulmus, Y. Pehlivan
Spin-Flavor Precession Phase Effects in Supernova
18 pages, 10 figures
null
10.1016/j.cjph.2024.07.001
null
hep-ph astro-ph.HE astro-ph.SR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the phase effects driven by neutrino magnetic moment for Majorana neutrinos in a core collapse supernova. A neutrino with a large magnetic moment is emitted in a superposition of energy eigenstates from the neutrinosphere. These energy eigenstates can interfere to create a phase effect at a partially adiabatic spin flavor precession (SFP) resonance. We examine the dependence of the SFP phase effect on the size of the neutrino magnetic moment as well as its variation with the post bounce time. In particular, at late post-bounce times the SFP resonance becomes wider and eventually overlaps with the Mikheev-Smirnov-Wolfenstein (MSW) resonance. At this point, Landau-Zener criteria for adiabaticity can no longer be applied to individual resonances, but we show that SFP phase effect is still present after the overlap. We also discuss the observability of the SFP phase effect at late post bounce times where it is more likely to make an impact. Our analysis for the Deep Underground Neutrino Experiment (DUNE) reveals that at low energies event rates do not fluctuate despite the presence of a sizable SFP phase effect. We find larger event rate fluctuations at high energies, but these fluctuations are also erased in the energy spectra of the observed charged leptons. A more refined treatment of electron fraction and the inclusion of neutrino-neutrino interactions may change our conclusions for observability in future studies.
[ { "created": "Sun, 14 Aug 2022 21:45:46 GMT", "version": "v1" }, { "created": "Tue, 13 Dec 2022 12:47:55 GMT", "version": "v2" }, { "created": "Fri, 29 Dec 2023 08:02:16 GMT", "version": "v3" }, { "created": "Tue, 9 Jul 2024 20:00:27 GMT", "version": "v4" } ]
2024-07-11
[ [ "Bulmus", "T.", "" ], [ "Pehlivan", "Y.", "" ] ]
We study the phase effects driven by neutrino magnetic moment for Majorana neutrinos in a core collapse supernova. A neutrino with a large magnetic moment is emitted in a superposition of energy eigenstates from the neutrinosphere. These energy eigenstates can interfere to create a phase effect at a partially adiabatic spin flavor precession (SFP) resonance. We examine the dependence of the SFP phase effect on the size of the neutrino magnetic moment as well as its variation with the post bounce time. In particular, at late post-bounce times the SFP resonance becomes wider and eventually overlaps with the Mikheev-Smirnov-Wolfenstein (MSW) resonance. At this point, Landau-Zener criteria for adiabaticity can no longer be applied to individual resonances, but we show that SFP phase effect is still present after the overlap. We also discuss the observability of the SFP phase effect at late post bounce times where it is more likely to make an impact. Our analysis for the Deep Underground Neutrino Experiment (DUNE) reveals that at low energies event rates do not fluctuate despite the presence of a sizable SFP phase effect. We find larger event rate fluctuations at high energies, but these fluctuations are also erased in the energy spectra of the observed charged leptons. A more refined treatment of electron fraction and the inclusion of neutrino-neutrino interactions may change our conclusions for observability in future studies.
hep-ph/9612249
L. B. Okun
L. B. Okun
Fundamental Constants of Nature
10 pages, Latex, Invited paper to appear in the Proceedings of the Fifteenth International Conference on Atomic Physics: Zeeman-effect centenary. Wan der Waals - Zeeman Laboratory, University of Amsterdam, August 5-9, 1996
null
null
ITEP-TH-56/96
hep-ph
null
A brief review, from basic atomic constants to "Mendeleev Table" of leptons, quarks, fundamental bosons, and then to superunification of all forces and particles.
[ { "created": "Wed, 4 Dec 1996 13:21:15 GMT", "version": "v1" } ]
2007-05-23
[ [ "Okun", "L. B.", "" ] ]
A brief review, from basic atomic constants to "Mendeleev Table" of leptons, quarks, fundamental bosons, and then to superunification of all forces and particles.
hep-ph/9308331
null
M.B. Einhorn
Theory of Gauge Boson Structure
19 pages, (August, 1993) (LaTeX (article style) but input phyzzx.fonts, 4 figure files encoded using "uufiles"; hardcopies available upon request.) preprint UM-TH-93-17
null
null
null
hep-ph
null
Based on an Invited Plenary Talk given at ``Workshop on Physics and Experiments with Linear $e^+e^-$ Colliders,'' Waikoloa, Hawaii, April 26--30, 1993. This paper reviews theoretical issues concerning the structure of vector bosons, with emphasis on deviations of triple-vector-boson interactions from the predictions of the Standard Model. Particular emphasis is on the role of gauge invariance in understanding the behavior of vector particles over energy scales large compared to their masses.
[ { "created": "Tue, 24 Aug 1993 18:58:26 GMT", "version": "v1" } ]
2007-05-23
[ [ "Einhorn", "M. B.", "" ] ]
Based on an Invited Plenary Talk given at ``Workshop on Physics and Experiments with Linear $e^+e^-$ Colliders,'' Waikoloa, Hawaii, April 26--30, 1993. This paper reviews theoretical issues concerning the structure of vector bosons, with emphasis on deviations of triple-vector-boson interactions from the predictions of the Standard Model. Particular emphasis is on the role of gauge invariance in understanding the behavior of vector particles over energy scales large compared to their masses.
hep-ph/9212247
null
S.M. Bilenky
Neutrino Mixing
DFTT 67/92, LaTeX file, no figures
null
null
null
hep-ph
null
In the first part of these lectures the neutrino mixing hypothesis will be considered in detail. We will discuss the possible schemes of neutrino mixing and present the data of the recent experiments searching for effects due to nonvanishing neutrino masses and mixing angles.In the second part of these lectures the physics of solar neutrinos will be considered.We will discuss the MSW resonance solution of the equation of evolution of a neutrino in matter and present data of solar neutrino experiments.
[ { "created": "Thu, 10 Dec 1992 13:28:00 GMT", "version": "v1" } ]
2007-05-23
[ [ "Bilenky", "S. M.", "" ] ]
In the first part of these lectures the neutrino mixing hypothesis will be considered in detail. We will discuss the possible schemes of neutrino mixing and present the data of the recent experiments searching for effects due to nonvanishing neutrino masses and mixing angles.In the second part of these lectures the physics of solar neutrinos will be considered.We will discuss the MSW resonance solution of the equation of evolution of a neutrino in matter and present data of solar neutrino experiments.
1004.3404
Chun Hay Kom
C. H. Kom and W. J. Stirling
Charge asymmetry in W + jets production at the LHC
13 pages, 7 figures. Reference added. Slightly modified text
Eur.Phys.J.C69:67-73,2010
10.1140/epjc/s10052-010-1353-z
Cavendish-HEP-2010/06
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The charge asymmetry in W + jets production at the LHC can serve to calibrate the presence of New Physics contributions. We study the ratio {\sigma}(W^+ + n jets)/{\sigma}(W^- + n jets) in the Standard Model for n <= 4, paying particular attention to the uncertainty in the prediction from higher-order perturbative corrections and uncertainties in parton distribution functions. We show that these uncertainties are generally of order a few percent, making the experimental measurement of the charge asymmetry ratio a particularly useful diagnostic tool for New Physics contributions.
[ { "created": "Tue, 20 Apr 2010 10:54:55 GMT", "version": "v1" }, { "created": "Thu, 29 Apr 2010 17:49:44 GMT", "version": "v2" }, { "created": "Wed, 25 Aug 2010 14:04:12 GMT", "version": "v3" } ]
2011-03-28
[ [ "Kom", "C. H.", "" ], [ "Stirling", "W. J.", "" ] ]
The charge asymmetry in W + jets production at the LHC can serve to calibrate the presence of New Physics contributions. We study the ratio {\sigma}(W^+ + n jets)/{\sigma}(W^- + n jets) in the Standard Model for n <= 4, paying particular attention to the uncertainty in the prediction from higher-order perturbative corrections and uncertainties in parton distribution functions. We show that these uncertainties are generally of order a few percent, making the experimental measurement of the charge asymmetry ratio a particularly useful diagnostic tool for New Physics contributions.
hep-ph/0106191
Peter Kroll
P. Kroll (Wuppertal Univ.)
Generalized parton distributions at large momentum transfer
6 pages, 6 figures (using LATEX with sprocl.sty and epsfig), talk presented at the 9th International Workshop on Deep Inelastic Scattering (DIS2001), Bologna, April 2001
null
10.1142/9789812778345_0100
null
hep-ph
null
The role of generalized parton distributions in wide-angle exclusive reactions will be discussed. In contrast to deep virtual exclusive reactions the wide angle processes offer the possibility of investigating the generalized parton distributions at large momentum transfer.
[ { "created": "Mon, 18 Jun 2001 09:41:29 GMT", "version": "v1" } ]
2015-06-25
[ [ "Kroll", "P.", "", "Wuppertal Univ." ] ]
The role of generalized parton distributions in wide-angle exclusive reactions will be discussed. In contrast to deep virtual exclusive reactions the wide angle processes offer the possibility of investigating the generalized parton distributions at large momentum transfer.
2206.13520
Hongwan Liu
James S. Bolton, Andrea Caputo, Hongwan Liu and Matteo Viel
Hints of dark photon dark matter from observations and hydrodynamical simulations of the low-redshift Lyman-$\alpha$ forest
5+1 pages, 2+1 figures
null
10.1103/PhysRevLett.129.211102
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent work has suggested that an additional $\lesssim 6.9 \rm{\, eV}$ per baryon of heating in the intergalactic medium is needed to reconcile hydrodynamical simulations with Lyman-$\alpha$ forest absorption line widths at redshift $z\simeq 0.1$. Resonant conversion of dark photon dark matter into low frequency photons is a viable source of such heating. We perform the first hydrodynamical simulations including dark photon heating and show that dark photons with mass $m_{A'}\sim 8\times 10^{-14}\rm\,eV\,c^{-2}$ and kinetic mixing $\epsilon \sim 5\times 10^{-15}$ can alleviate the heating excess. A prediction of this model is a non-standard thermal history for underdense gas at $z \gtrsim 3$.
[ { "created": "Mon, 27 Jun 2022 18:00:00 GMT", "version": "v1" } ]
2023-07-19
[ [ "Bolton", "James S.", "" ], [ "Caputo", "Andrea", "" ], [ "Liu", "Hongwan", "" ], [ "Viel", "Matteo", "" ] ]
Recent work has suggested that an additional $\lesssim 6.9 \rm{\, eV}$ per baryon of heating in the intergalactic medium is needed to reconcile hydrodynamical simulations with Lyman-$\alpha$ forest absorption line widths at redshift $z\simeq 0.1$. Resonant conversion of dark photon dark matter into low frequency photons is a viable source of such heating. We perform the first hydrodynamical simulations including dark photon heating and show that dark photons with mass $m_{A'}\sim 8\times 10^{-14}\rm\,eV\,c^{-2}$ and kinetic mixing $\epsilon \sim 5\times 10^{-15}$ can alleviate the heating excess. A prediction of this model is a non-standard thermal history for underdense gas at $z \gtrsim 3$.
2310.11067
Martin Vollmann
Barbara J\"ager and Martin Vollmann
Sommerfeld effect for continuum gamma-ray spectra from Dark Matter annihilation
25 pages, 6 figures
null
null
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a calculation of the continuum part of the gamma-ray spectra resulting from Dark Matter annihilation in the framework of the MSSM taking into account Sommerfeld effects. Concentrating on pure wino and pure higgsino scenarios we compare our calculation to existing work and explore the numerical impact of the features not captured by previous approximative descriptions. We find that, in particular for large neutralino masses, when the Sommerfeld enhancement is very large, chargino-antichargino annihilation processes, which have not been considered before, lead to sizable differences with respect to existing calculations. In scenarios with neutralinos in the intermediate-mass range, we find that the role of the charginos is crucial in the endpoint regime. Our calculation provides the currently most accurate prediction for the continuum gamma-ray spectra.
[ { "created": "Tue, 17 Oct 2023 08:19:15 GMT", "version": "v1" } ]
2023-10-18
[ [ "Jäger", "Barbara", "" ], [ "Vollmann", "Martin", "" ] ]
We present a calculation of the continuum part of the gamma-ray spectra resulting from Dark Matter annihilation in the framework of the MSSM taking into account Sommerfeld effects. Concentrating on pure wino and pure higgsino scenarios we compare our calculation to existing work and explore the numerical impact of the features not captured by previous approximative descriptions. We find that, in particular for large neutralino masses, when the Sommerfeld enhancement is very large, chargino-antichargino annihilation processes, which have not been considered before, lead to sizable differences with respect to existing calculations. In scenarios with neutralinos in the intermediate-mass range, we find that the role of the charginos is crucial in the endpoint regime. Our calculation provides the currently most accurate prediction for the continuum gamma-ray spectra.
1306.3984
Constantin Sluka
Stefan Antusch, Christian Gross, Vinzenz Maurer, Constantin Sluka
Inverse neutrino mass hierarchy in a flavour GUT model
18 pages, version published in NPB
Nucl.Phys. B879 (2014) 19-36
10.1016/j.nuclphysb.2013.11.017
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct a supersymmetric SU(5) x A_4 flavour GUT model in which an inverse neutrino mass hierarchy is realised without fine-tuning of parameters. The model shares some properties with the normal hierarchy model which we presented in arXiv:1305.6612 - in particular the relation theta_13^PMNS = theta_C / sqrt(2). Besides these shared features, there are also important differences, mainly due to the different neutrino sector. These differences not only change the predictions in the lepton sector, but also in the quark sector, and will allow to discriminate between the two models using the results of present and future experiments. From a Markov Chain Monte Carlo fit we find that the inverse hierarchy model is in excellent agreement with the present experimental data.
[ { "created": "Mon, 17 Jun 2013 20:00:00 GMT", "version": "v1" }, { "created": "Tue, 17 Dec 2013 18:12:33 GMT", "version": "v2" } ]
2013-12-18
[ [ "Antusch", "Stefan", "" ], [ "Gross", "Christian", "" ], [ "Maurer", "Vinzenz", "" ], [ "Sluka", "Constantin", "" ] ]
We construct a supersymmetric SU(5) x A_4 flavour GUT model in which an inverse neutrino mass hierarchy is realised without fine-tuning of parameters. The model shares some properties with the normal hierarchy model which we presented in arXiv:1305.6612 - in particular the relation theta_13^PMNS = theta_C / sqrt(2). Besides these shared features, there are also important differences, mainly due to the different neutrino sector. These differences not only change the predictions in the lepton sector, but also in the quark sector, and will allow to discriminate between the two models using the results of present and future experiments. From a Markov Chain Monte Carlo fit we find that the inverse hierarchy model is in excellent agreement with the present experimental data.
hep-ph/0412402
Munshi Golam Mustafa Dr.
Munshi G. Mustafa
Energy Loss of Charm Quarks in the Quark-Gluon Plasma: Collisional vs Radiative
14 pages, 6 figures; this version is compiled with various sections than the earlier one along with additional discussion, one extra figure (Fig. 3) and two new curves in Fig. 4 in support of one approximation; revised version accepted in Phys. Rev. C
Phys.Rev.C72:014905,2005
10.1103/PhysRevC.72.014905
null
hep-ph nucl-th
null
Considering the collisional energy loss rates of heavy quarks from hard light parton interactions the total energy loss of a charm quark for a static medium has been computed. For the energy range $E\sim (5-10)$ GeV of charm quark, it is found to be almost same order as that of radiative ones estimated to a first order opacity expansion. The collisional energy loss will become much more important for lower energy charm quarks and this feature could be very interesting for phenomenology of hadrons spectra. Using such collisional energy loss rates we estimate the momentum loss distribution employing a Fokker-Planck equation and the total energy loss of a charm quark for an expanding quark-gluon plasma under conditions resembling the RHIC energies. The fractional collisional energy loss is found to be suppressed by a factor of 5 as compared to static case and does not depend linearly on the system size. We also investigate the heavy to light hadrons $D/\pi$ ratio at moderately large (5-10) GeV/$c$ transverse momenta and comment on its enhancement.
[ { "created": "Wed, 29 Dec 2004 02:43:37 GMT", "version": "v1" }, { "created": "Tue, 24 May 2005 08:43:45 GMT", "version": "v2" } ]
2008-11-26
[ [ "Mustafa", "Munshi G.", "" ] ]
Considering the collisional energy loss rates of heavy quarks from hard light parton interactions the total energy loss of a charm quark for a static medium has been computed. For the energy range $E\sim (5-10)$ GeV of charm quark, it is found to be almost same order as that of radiative ones estimated to a first order opacity expansion. The collisional energy loss will become much more important for lower energy charm quarks and this feature could be very interesting for phenomenology of hadrons spectra. Using such collisional energy loss rates we estimate the momentum loss distribution employing a Fokker-Planck equation and the total energy loss of a charm quark for an expanding quark-gluon plasma under conditions resembling the RHIC energies. The fractional collisional energy loss is found to be suppressed by a factor of 5 as compared to static case and does not depend linearly on the system size. We also investigate the heavy to light hadrons $D/\pi$ ratio at moderately large (5-10) GeV/$c$ transverse momenta and comment on its enhancement.
1309.7343
Bogumi{\l}a \'Swie\.zewska
Bogumila Swiezewska
Decay rates of the Higgs boson to two photons and Z plus photon in Z_2-symmetric Two Higgs Doublet Models
3 pages, 2 figures, contribution to the proceedings of the European Physical Society Conference on High Energy Physics "EPS HEP 2013" (18-24 July 2013, Stockholm, Sweden), based on arXiv:1212.4100 [hep-ph] and arXiv:1305.6266 [hep-ph]
PoS(EPS-HEP 2013)066
null
IFT-8/2013
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Analysis of the 125 GeV Higgs boson decay rates to two photons and Z plus photon in the Inert Doublet Model is presented. We study the constraints on the masses of the scalars (in particular the Dark Matter candidate) and their couplings to the Higgs boson, coming from the h -> \gamma\gamma data and confront them with the WMAP measurements of the Dark Matter relic density.
[ { "created": "Fri, 27 Sep 2013 19:57:10 GMT", "version": "v1" } ]
2014-01-03
[ [ "Swiezewska", "Bogumila", "" ] ]
Analysis of the 125 GeV Higgs boson decay rates to two photons and Z plus photon in the Inert Doublet Model is presented. We study the constraints on the masses of the scalars (in particular the Dark Matter candidate) and their couplings to the Higgs boson, coming from the h -> \gamma\gamma data and confront them with the WMAP measurements of the Dark Matter relic density.
1812.00179
Huifeng Fu
Hui-feng Fu, Libo Jiang
Coupled-Channel-Induced $S-D$ mixing of Charmonia and Testing Possible Assignments for $Y(4260)$ and $Y(4360)$
13 pages, 5 figures, 5 tables
Eur. Phys. J. C (2019) 79:460
10.1140/epjc/s10052-019-6976-0
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The mass spectrum and the two-body open-charm decays of the $J^{PC}=1^{--}$ charmonium states are studied with the coupled-channel effects taken into account. The coupled-channel-induced mixing effects among the excited vector charmonia are studied. Based on our calculations of the masses and the decay widths, we find that the tension between the observed properties of $Y(4260)/Y(4360)$ and their conventional charmonia interpretations could be softened.
[ { "created": "Sat, 1 Dec 2018 09:11:08 GMT", "version": "v1" }, { "created": "Mon, 3 Jun 2019 12:57:35 GMT", "version": "v2" } ]
2019-06-04
[ [ "Fu", "Hui-feng", "" ], [ "Jiang", "Libo", "" ] ]
The mass spectrum and the two-body open-charm decays of the $J^{PC}=1^{--}$ charmonium states are studied with the coupled-channel effects taken into account. The coupled-channel-induced mixing effects among the excited vector charmonia are studied. Based on our calculations of the masses and the decay widths, we find that the tension between the observed properties of $Y(4260)/Y(4360)$ and their conventional charmonia interpretations could be softened.
2401.02168
Waqas Ahmed
Waqas Ahmed, Shabbar Raza
Supersymmetric Hybrid Inflation in Light of CMB Experiments and Swampland Conjectures
31 pages, 9 figures
null
null
null
hep-ph gr-qc
http://creativecommons.org/licenses/by-nc-sa/4.0/
This study revisits supersymmetric (SUSY) hybrid inflation in light of CMB experiments and swampland conjectures. We first show that if one adds radiative, soft mass, and SUGRA corrections to the scalar potential, supersymmetric hybrid inflation is still consistent with Planck 2018 despite an impression that it does not. Usually, in SUSY hybrid inflation with minimal K\"ahler potential, the gauge symmetry breaking scale $M$ turns out to be ${\cal O}(10^{15})$ GeV, which causes proton decay rate problem. In this study, we present a new parameter space where the proton decay rate problem can be avoided by achieving $M$ of the order of $10^{16}$ GeV with $M_{S}^{2}<$0 and $am_{3/2}>$0. In this scenario, one requires a soft SUSY breaking scale $|M_{S}| \gtrsim 10^{6}$ GeV. Moreover, the tensor to scalar ratio $r$ is in the range $10^{-16}$ to $10^{-6}$, which is quite small. In this case, modified swampland hold, but it is difficult to satisfy trans-Planckian censorship conjecture. For this reason, we also consider non-minimal K\"ahler potential. We fixed spectral index $n_{S}=$0.9665 (central value) of Planck 2018 data and $M=2\times 10^{16}$ GeV and present our calculations. We show the canonical measure of primordial gravity waves $r$ for $M_{S}=$ 1 TeV, $m_{3/2}=$ 1 TeV, $\kappa_{S}<0$ for $\cal{N}=$1 and $\cal{N}=$2, ranges from $10^{-5}$ to $0.01$ which can be observed in Planck and next-generation experiments such as LiteBIRD, Simons Observatory, PRISM, PIXIE,CORE, CMB-S4 and CMB-HD experiments that are gearing up to measure it. In addition to it, we present the parametric space and benchmark points for a non-minimal case which is consistent with modified swampland and trans-Planckian censorship conjectures.
[ { "created": "Thu, 4 Jan 2024 09:48:32 GMT", "version": "v1" }, { "created": "Thu, 25 Jan 2024 12:00:42 GMT", "version": "v2" } ]
2024-01-26
[ [ "Ahmed", "Waqas", "" ], [ "Raza", "Shabbar", "" ] ]
This study revisits supersymmetric (SUSY) hybrid inflation in light of CMB experiments and swampland conjectures. We first show that if one adds radiative, soft mass, and SUGRA corrections to the scalar potential, supersymmetric hybrid inflation is still consistent with Planck 2018 despite an impression that it does not. Usually, in SUSY hybrid inflation with minimal K\"ahler potential, the gauge symmetry breaking scale $M$ turns out to be ${\cal O}(10^{15})$ GeV, which causes proton decay rate problem. In this study, we present a new parameter space where the proton decay rate problem can be avoided by achieving $M$ of the order of $10^{16}$ GeV with $M_{S}^{2}<$0 and $am_{3/2}>$0. In this scenario, one requires a soft SUSY breaking scale $|M_{S}| \gtrsim 10^{6}$ GeV. Moreover, the tensor to scalar ratio $r$ is in the range $10^{-16}$ to $10^{-6}$, which is quite small. In this case, modified swampland hold, but it is difficult to satisfy trans-Planckian censorship conjecture. For this reason, we also consider non-minimal K\"ahler potential. We fixed spectral index $n_{S}=$0.9665 (central value) of Planck 2018 data and $M=2\times 10^{16}$ GeV and present our calculations. We show the canonical measure of primordial gravity waves $r$ for $M_{S}=$ 1 TeV, $m_{3/2}=$ 1 TeV, $\kappa_{S}<0$ for $\cal{N}=$1 and $\cal{N}=$2, ranges from $10^{-5}$ to $0.01$ which can be observed in Planck and next-generation experiments such as LiteBIRD, Simons Observatory, PRISM, PIXIE,CORE, CMB-S4 and CMB-HD experiments that are gearing up to measure it. In addition to it, we present the parametric space and benchmark points for a non-minimal case which is consistent with modified swampland and trans-Planckian censorship conjectures.
hep-ph/9603379
Gabriela Barenboim
G.Barenboim and J.Bernabeu
Spontaneous breakdown of CP in left-right symmetric models
22 pages, 1 postcript figure
Z.Phys. C73 (1997) 321-331
null
FTUV/96-9,IFIC/96-10
hep-ph
null
We show that it is possible to obtain spontaneous CP violation in the minimal $SU(2)_L \times SU(2)_R \times U(1)_{B-L}$, i.e. in a left right symmetric model containing a bidoublet and two triplets in the scalar sector. For this to be a natural scenario, the non-diagonal quartic couplings between the two scalar triplets and the bidoublet play a fundamental role. We analyze the corresponding Higgs spectrum, the suppression of FCNC's and the manifestation of the spontaneous CP phase in the electric dipole moment of the electron.
[ { "created": "Fri, 22 Mar 1996 10:54:38 GMT", "version": "v1" } ]
2007-05-23
[ [ "Barenboim", "G.", "" ], [ "Bernabeu", "J.", "" ] ]
We show that it is possible to obtain spontaneous CP violation in the minimal $SU(2)_L \times SU(2)_R \times U(1)_{B-L}$, i.e. in a left right symmetric model containing a bidoublet and two triplets in the scalar sector. For this to be a natural scenario, the non-diagonal quartic couplings between the two scalar triplets and the bidoublet play a fundamental role. We analyze the corresponding Higgs spectrum, the suppression of FCNC's and the manifestation of the spontaneous CP phase in the electric dipole moment of the electron.
hep-ph/0601135
Pietro Slavich
G. Degrassi, P. Gambino and P. Slavich
QCD Corrections to Radiative B Decays in the MSSM with Minimal Flavor Violation
16 pages, 5 figures; v2: version to appear in Phys. Lett. B
Phys.Lett.B635:335-342,2006
10.1016/j.physletb.2006.02.067
RM3-TH/06-1, DFTT-03/2006, LAPTH-1136/06
hep-ph
null
We compute the complete supersymmetric QCD corrections to the Wilson coefficients of the magnetic and chromomagnetic operators, relevant in the calculation of b -> s gamma decays, in the MSSM with Minimal Flavor Violation. We investigate the numerical impact of the new results for different choices of the MSSM parameters and of the scale where the quark and squark mass matrices are assumed to be aligned. We find that the corrections can be important when the superpartners are relatively light, and that they depend sizeably on the scale of alignment. Finally, we discuss how our calculation can be employed when the scale of alignment is far from the weak scale.
[ { "created": "Tue, 17 Jan 2006 17:57:39 GMT", "version": "v1" }, { "created": "Fri, 17 Mar 2006 17:45:22 GMT", "version": "v2" } ]
2011-07-18
[ [ "Degrassi", "G.", "" ], [ "Gambino", "P.", "" ], [ "Slavich", "P.", "" ] ]
We compute the complete supersymmetric QCD corrections to the Wilson coefficients of the magnetic and chromomagnetic operators, relevant in the calculation of b -> s gamma decays, in the MSSM with Minimal Flavor Violation. We investigate the numerical impact of the new results for different choices of the MSSM parameters and of the scale where the quark and squark mass matrices are assumed to be aligned. We find that the corrections can be important when the superpartners are relatively light, and that they depend sizeably on the scale of alignment. Finally, we discuss how our calculation can be employed when the scale of alignment is far from the weak scale.
hep-ph/0311047
Sancho Moura Oliveira
S. M. Oliveira and R. Santos
New bounds on the mass of a b' quark
Presented by R. Santos at XXVII International Conference of Theoretical Physics, `Matter To The Deepest', Ustron, 15-21 September 2003, Poland. To appear in Acta Physica Polonica, http://th-www.if.uj.edu.pl/acta/
Acta Phys.Polon.B34:5523-5530,2003
null
null
hep-ph
null
In this work we present limits on a sequential down-type quark, b', based on the most recent DELPHI data. Using all available experimental data for m_b' > 96 GeV we conclude that a sequential four generations model is far from being experimentally excluded.
[ { "created": "Tue, 4 Nov 2003 13:54:40 GMT", "version": "v1" } ]
2010-11-23
[ [ "Oliveira", "S. M.", "" ], [ "Santos", "R.", "" ] ]
In this work we present limits on a sequential down-type quark, b', based on the most recent DELPHI data. Using all available experimental data for m_b' > 96 GeV we conclude that a sequential four generations model is far from being experimentally excluded.
2211.05787
Anirudh Prabhu
Anirudh Prabhu and Carlos Blanco
Constraints on Dark Matter-Electron Scattering from Molecular Cloud Ionization
8 pages, 3 figures
null
10.1103/PhysRevD.108.035035
null
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
We demonstrate that ionization of $\text{H}_2$ by dark matter in dense molecular clouds can provide strong constraints on the scattering strength of dark matter with electrons. Molecular clouds have high UV-optical attenuation, shielding them from ultraviolet and X-ray photons. Their chemical and thermal evolution are governed by low-energy cosmic rays. Dark matter with mass $\gtrsim 4$ MeV can ionize $\text{H}_2$, contributing to the observed ionization rate. We require that the dark matter-induced ionization rate of $\text{H}_2$ not exceed the observed cosmic ray ionization rate, $\zeta^{\text{H}_2}$, in diffuse molecular clouds as well as dense molecular clouds such as L1551 in the Taurus cloud complex. This allow us to place strong constraints on the DM-electron cross section, $\bar{\sigma}_e$, that complement existing astrophysical constraints and probe the strongly interacting parameter space where terrestrial and underground direct detection experiments lose sensitivity. We show that constraints from molecular clouds combined with planned balloon and satellite-based experiments would strongly constrain the fractional abundance of dark matter that interacts strongly with electrons. We comment on future modeling and observational efforts that may improve our bounds.
[ { "created": "Thu, 10 Nov 2022 19:00:00 GMT", "version": "v1" } ]
2023-08-28
[ [ "Prabhu", "Anirudh", "" ], [ "Blanco", "Carlos", "" ] ]
We demonstrate that ionization of $\text{H}_2$ by dark matter in dense molecular clouds can provide strong constraints on the scattering strength of dark matter with electrons. Molecular clouds have high UV-optical attenuation, shielding them from ultraviolet and X-ray photons. Their chemical and thermal evolution are governed by low-energy cosmic rays. Dark matter with mass $\gtrsim 4$ MeV can ionize $\text{H}_2$, contributing to the observed ionization rate. We require that the dark matter-induced ionization rate of $\text{H}_2$ not exceed the observed cosmic ray ionization rate, $\zeta^{\text{H}_2}$, in diffuse molecular clouds as well as dense molecular clouds such as L1551 in the Taurus cloud complex. This allow us to place strong constraints on the DM-electron cross section, $\bar{\sigma}_e$, that complement existing astrophysical constraints and probe the strongly interacting parameter space where terrestrial and underground direct detection experiments lose sensitivity. We show that constraints from molecular clouds combined with planned balloon and satellite-based experiments would strongly constrain the fractional abundance of dark matter that interacts strongly with electrons. We comment on future modeling and observational efforts that may improve our bounds.
hep-ph/0701079
Fabio L. Braghin
Fabio L. Braghin
Aspects of matter-antimatter asymmetries in relativistic heavy ions collisions and Astroparticle Physics
Work presented at the 18th International Symposium Multiparticle Dynamics, Paraty September 2006. 3 pages
null
null
null
hep-ph
null
Matter-antimatter asymmetries observed in high energy / relativistic heavy ion collisions and, differently, in the Early Universe are discussed considering ideas from the phase diagram of strong interactions with assumptions that do not necessarilly rely on non-equilibrium conditions, and that are based in effects such as spontaneous symmetry breaking.
[ { "created": "Wed, 10 Jan 2007 14:59:27 GMT", "version": "v1" } ]
2007-05-23
[ [ "Braghin", "Fabio L.", "" ] ]
Matter-antimatter asymmetries observed in high energy / relativistic heavy ion collisions and, differently, in the Early Universe are discussed considering ideas from the phase diagram of strong interactions with assumptions that do not necessarilly rely on non-equilibrium conditions, and that are based in effects such as spontaneous symmetry breaking.
hep-ph/9603436
Colin Froggatt
C. D. Froggatt, H. B. Nielsen and D. J. Smith
Could there be a Fourth Generation of Quarks Without More Leptons?
uuencoded 17 page LaTeX file plus 2 postscript figures, uses epsf.sty
Z.Phys.C73:333-337,1997
10.1007/s002880050322
GUTPA/95/01/1
hep-ph
null
We investigate the possibility of adding a fourth generation of quarks. We also extend the Standard Model gauge group by adding another SU(N) component. In order to cancel the contributions of the fourth generation of quarks to the gauge anomalies we must add a generation of fermions coupling to the SU(N) group. This model has many features similar to the Standard Model and, for example, includes a natural generalisation of the Standard Model charge quantisation rule. We discuss the phenomenology of this model and, in particular, show that the infrared quasi-fixed point values of the Yukawa coupling constants put upper limits on the new quark masses close to the present experimental lower bounds.
[ { "created": "Fri, 29 Mar 1996 13:21:51 GMT", "version": "v1" } ]
2008-11-26
[ [ "Froggatt", "C. D.", "" ], [ "Nielsen", "H. B.", "" ], [ "Smith", "D. J.", "" ] ]
We investigate the possibility of adding a fourth generation of quarks. We also extend the Standard Model gauge group by adding another SU(N) component. In order to cancel the contributions of the fourth generation of quarks to the gauge anomalies we must add a generation of fermions coupling to the SU(N) group. This model has many features similar to the Standard Model and, for example, includes a natural generalisation of the Standard Model charge quantisation rule. We discuss the phenomenology of this model and, in particular, show that the infrared quasi-fixed point values of the Yukawa coupling constants put upper limits on the new quark masses close to the present experimental lower bounds.
2210.17110
Marco Drewes
Marco Drewes
Distinguishing Dirac and Majorana Heavy Neutrinos at Lepton Colliders
Typos corrected, an error fixed, discussion extended, references added, link to GitHub repository with code for sensitivity region estimates added. Contribution to the proceedings of the 41st International Conference on High Energy Physics (ICHEP2022). Footnotes added with additional explanations that cannot be accommodated in the PoS page limit, but will hopefully make the document more useful
PoS ICHEP2022 (2022) 608
10.22323/1.414.0608
IRMP-CP3-22-52
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the potential to observe lepton number violation (LNV) in displaced vertex searches for heavy neutral leptons (HNLs) at future lepton colliders. Even though a direct detection of LNV is impossible for the dominant production channel because lepton number is carried away by an unobservable neutrino, there are several signatures of LNV that can be searched for. They include the angular distribution and spectrum of decay products as well as the HNL lifetime. We comment on the perspectives to observe LNV in realistic neutrino mass models and argue that the dichotomy of Dirac vs Majorana HNLs is in general not sufficient to effectively capture their phenomenology, but these extreme cases nevertheless represent well-defined benchmarks for experimental searches. Finally, we present accurate analytic estimates for the number of events and sensitivity regions during the $Z$-pole run for both Majorana and Dirac HNLs.
[ { "created": "Mon, 31 Oct 2022 07:35:36 GMT", "version": "v1" }, { "created": "Fri, 16 Dec 2022 14:37:31 GMT", "version": "v2" } ]
2023-01-16
[ [ "Drewes", "Marco", "" ] ]
We discuss the potential to observe lepton number violation (LNV) in displaced vertex searches for heavy neutral leptons (HNLs) at future lepton colliders. Even though a direct detection of LNV is impossible for the dominant production channel because lepton number is carried away by an unobservable neutrino, there are several signatures of LNV that can be searched for. They include the angular distribution and spectrum of decay products as well as the HNL lifetime. We comment on the perspectives to observe LNV in realistic neutrino mass models and argue that the dichotomy of Dirac vs Majorana HNLs is in general not sufficient to effectively capture their phenomenology, but these extreme cases nevertheless represent well-defined benchmarks for experimental searches. Finally, we present accurate analytic estimates for the number of events and sensitivity regions during the $Z$-pole run for both Majorana and Dirac HNLs.
1505.01059
Abdelhak Djouadi
Abdelhak Djouadi
Higgs Physics
18 pages, 15 figures. Proceedings of the Corfu Summer Institute 2014 "School and Workshops on Elementary Particle Physics and Gravity", 3-21 September 2014, Corfu, Greece
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The implications of the discovery of a scalar Higgs boson at the LHC with a mass of approximately 125 GeV are summarised in the context of the Standard Model of particle physics with its unique scalar boson and of its most celebrated new physics extension, the minimal supersymmetric Standard Model or MSSM, in which the Higgs sector is extended to contain three neutral and two charged scalar bosons. Discussed are the implications from the measured mass, the production and decay rates of the observed particle and, in the MSSM, from the constraints in the search for the heavier Higgs states. The perspectives for Higgs and new physics searches at the next LHC upgrades as well as at future hadron and lepton colliders are then briefly summarized.
[ { "created": "Tue, 5 May 2015 16:05:51 GMT", "version": "v1" } ]
2015-05-06
[ [ "Djouadi", "Abdelhak", "" ] ]
The implications of the discovery of a scalar Higgs boson at the LHC with a mass of approximately 125 GeV are summarised in the context of the Standard Model of particle physics with its unique scalar boson and of its most celebrated new physics extension, the minimal supersymmetric Standard Model or MSSM, in which the Higgs sector is extended to contain three neutral and two charged scalar bosons. Discussed are the implications from the measured mass, the production and decay rates of the observed particle and, in the MSSM, from the constraints in the search for the heavier Higgs states. The perspectives for Higgs and new physics searches at the next LHC upgrades as well as at future hadron and lepton colliders are then briefly summarized.
2211.17092
Alexander Agafonov
A. I. Agafonov
Resonance enhancement of the electromagnetic interaction between two charged particles in the bound state in the continuum
4 pages, 1 figure
null
null
null
hep-ph hep-th
http://creativecommons.org/licenses/by-nc-nd/4.0/
In bound states in the continuum (BIC) the mass of a composite particle is greater than the total mass of its constituents. Using the ladder Bethe-Salpeter equation, the BIC state in a system of two charged particles $a$ and $b$ with different masses ($m_{b}>>m_{a}$) is investigated. We demonstrate that for the positive binding energy, there are two momentum space regions in which the electromagnetic interaction between the particles is strongly enhanced, and the effective coupling constant turns out to be equal to $\alpha \sqrt{m_{b}/m_{a}}$, where $\alpha$ is the fine structure constant. The interaction resonance leads to confinement of the constituents in the BIC state with the positive binding energy which is of the order of the mass of the lighter particle from the pair.
[ { "created": "Tue, 29 Nov 2022 11:07:34 GMT", "version": "v1" }, { "created": "Wed, 22 Feb 2023 09:58:04 GMT", "version": "v2" } ]
2023-02-23
[ [ "Agafonov", "A. I.", "" ] ]
In bound states in the continuum (BIC) the mass of a composite particle is greater than the total mass of its constituents. Using the ladder Bethe-Salpeter equation, the BIC state in a system of two charged particles $a$ and $b$ with different masses ($m_{b}>>m_{a}$) is investigated. We demonstrate that for the positive binding energy, there are two momentum space regions in which the electromagnetic interaction between the particles is strongly enhanced, and the effective coupling constant turns out to be equal to $\alpha \sqrt{m_{b}/m_{a}}$, where $\alpha$ is the fine structure constant. The interaction resonance leads to confinement of the constituents in the BIC state with the positive binding energy which is of the order of the mass of the lighter particle from the pair.
hep-ph/0209197
Hirotsugu Fujii
H. Fujii
J/psi suppression in heavy ion collisions by quark momentum diffusion
2 pages (1 figure)
Phys.Rev.C67:031901,2003
10.1103/PhysRevC.67.031901
UT-KOMABA-02-10
hep-ph nucl-th
null
The momentum diffusion effect of the quark pair due to the multiple scattering in a nuclear medium is studied to explain the observed J/psi yields in SPS experiments. The resulting suppression is found to be insufficient to reproduce the J/psi yield in Pb-Pb collisions at SPS energy.
[ { "created": "Wed, 18 Sep 2002 09:07:06 GMT", "version": "v1" }, { "created": "Mon, 11 Nov 2002 10:17:51 GMT", "version": "v2" }, { "created": "Tue, 24 Dec 2002 08:13:22 GMT", "version": "v3" } ]
2009-11-07
[ [ "Fujii", "H.", "" ] ]
The momentum diffusion effect of the quark pair due to the multiple scattering in a nuclear medium is studied to explain the observed J/psi yields in SPS experiments. The resulting suppression is found to be insufficient to reproduce the J/psi yield in Pb-Pb collisions at SPS energy.
hep-ph/9709439
Carlo Giunti
C. Giunti, C.W. Kim, M. Monteno
Atmospheric neutrino oscillations with three neutrinos and a mass hierarchy
42 pages, including 7 figures
Nucl.Phys.B521:3-36,1998
10.1016/S0550-3213(98)00105-9
DFTT 32/97, KIAS-P97004
hep-ph
null
A comprehensive formalism for the description of neutrino oscillations in the Earth in a general scheme with three massive neutrinos and the mass hierarchy m_1<<m_2<<m_3 is presented. Using this formalism, which is valid both in vacuum and in a medium, the matter effect on the oscillations of low-energy neutrinos is discussed, pointing out the existence of very long oscillations which are independent of the neutrino masses and the neutrino energy, and are very sensitive to the matter density along the neutrino trajectory. As an example of application of the formulation, a fit of the Kamiokande atmospheric neutrino data with the matter effect taken into account for neutrinos propagating in the Earth is presented. The results of the fit indicate that 4*10^{-3} eV^2 < m_3^2 < 4*10^{-2} eV^2 and the oscillation amplitudes in all channels (nu_mu<->nu_e, nu_mu<->nu_tau, nu_e<->nu_tau) could be large. Hence, long-baseline experiments with reactor (CHOOZ and Palo Verde) and accelerator (K2K, MINOS and ICARUS) neutrinos could observe neutrino oscillations in all channels with a relatively large statistics.
[ { "created": "Wed, 24 Sep 1997 13:35:00 GMT", "version": "v1" }, { "created": "Thu, 21 May 1998 11:51:11 GMT", "version": "v2" } ]
2011-07-19
[ [ "Giunti", "C.", "" ], [ "Kim", "C. W.", "" ], [ "Monteno", "M.", "" ] ]
A comprehensive formalism for the description of neutrino oscillations in the Earth in a general scheme with three massive neutrinos and the mass hierarchy m_1<<m_2<<m_3 is presented. Using this formalism, which is valid both in vacuum and in a medium, the matter effect on the oscillations of low-energy neutrinos is discussed, pointing out the existence of very long oscillations which are independent of the neutrino masses and the neutrino energy, and are very sensitive to the matter density along the neutrino trajectory. As an example of application of the formulation, a fit of the Kamiokande atmospheric neutrino data with the matter effect taken into account for neutrinos propagating in the Earth is presented. The results of the fit indicate that 4*10^{-3} eV^2 < m_3^2 < 4*10^{-2} eV^2 and the oscillation amplitudes in all channels (nu_mu<->nu_e, nu_mu<->nu_tau, nu_e<->nu_tau) could be large. Hence, long-baseline experiments with reactor (CHOOZ and Palo Verde) and accelerator (K2K, MINOS and ICARUS) neutrinos could observe neutrino oscillations in all channels with a relatively large statistics.
hep-ph/0603229
Ben Gripaios
Ben Gripaios and Stephen M. West
Improved Higgs Naturalness With or Without Supersymmetry
5 pages, 2 postscript figures; PRD version
Phys.Rev. D74 (2006) 075002
10.1103/PhysRevD.74.075002
OUTP-0607P
hep-ph
null
Many models of electroweak symmetry-breaking with an extended Higgs sector exhibit improved naturalness, wherein the new physics scale, at which quadratic divergences of Higgs mass parameters due to top quark loops are cut off, can be pushed beyond the reach of the Large Hadron Collider without unnatural fine tuning. Such models include examples where the new physics is supersymmetry, implying that supersymmetry may still solve the hierarchy problem, even if it eludes detection at the LHC.
[ { "created": "Tue, 28 Mar 2006 17:26:27 GMT", "version": "v1" }, { "created": "Tue, 29 Aug 2006 11:19:59 GMT", "version": "v2" }, { "created": "Thu, 12 Oct 2006 11:27:52 GMT", "version": "v3" } ]
2009-11-11
[ [ "Gripaios", "Ben", "" ], [ "West", "Stephen M.", "" ] ]
Many models of electroweak symmetry-breaking with an extended Higgs sector exhibit improved naturalness, wherein the new physics scale, at which quadratic divergences of Higgs mass parameters due to top quark loops are cut off, can be pushed beyond the reach of the Large Hadron Collider without unnatural fine tuning. Such models include examples where the new physics is supersymmetry, implying that supersymmetry may still solve the hierarchy problem, even if it eludes detection at the LHC.
2003.02802
Jesse Giron
Jesse F. Giron and Richard F. Lebed
The Spectrum of $P$-Wave Hidden-Charm Exotic Mesons in the Diquark Model
15 pages, 1 LaTeX figures. Small revisions to the Reference section. Level diagram has now been included as a figure
Phys. Rev. D 101, 074032 (2020)
10.1103/PhysRevD.101.074032
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the fine structure in the spectrum of known and predicted negative-parity hidden-charm exotic meson states, which comprise the lowest $P$-wave multiplet in the dynamical diquark model. Starting with a form previously shown to successfully describe the $S$-wave states, we develop a 5-parameter Hamiltonian that includes spin-orbit and tensor terms. After discussing the experimental status of the observed $J^{PC} = 1^{--}$ states $Y$ with respect to masses and decay modes (classified by eigenvalues of heavy-quark spin), we note a number of inconsistencies between measurements from different experiments that complicate a unique determination of the spectrum. Outlining a variety of scenarios for interpreting the $Y$ data, we perform fits to each one, obtaining results that demonstrate differing possibilities for the $P$-wave spectra. Choosing one of these fits for illustration, we predict masses for all 28 isomultiplets in this $1P$ multiplet, compare the results to tantalizing hints in the data, and discuss the rich discovery potential for new states.
[ { "created": "Thu, 5 Mar 2020 18:06:59 GMT", "version": "v1" }, { "created": "Wed, 11 Mar 2020 14:08:00 GMT", "version": "v2" }, { "created": "Tue, 14 Apr 2020 18:42:37 GMT", "version": "v3" } ]
2020-05-06
[ [ "Giron", "Jesse F.", "" ], [ "Lebed", "Richard F.", "" ] ]
We study the fine structure in the spectrum of known and predicted negative-parity hidden-charm exotic meson states, which comprise the lowest $P$-wave multiplet in the dynamical diquark model. Starting with a form previously shown to successfully describe the $S$-wave states, we develop a 5-parameter Hamiltonian that includes spin-orbit and tensor terms. After discussing the experimental status of the observed $J^{PC} = 1^{--}$ states $Y$ with respect to masses and decay modes (classified by eigenvalues of heavy-quark spin), we note a number of inconsistencies between measurements from different experiments that complicate a unique determination of the spectrum. Outlining a variety of scenarios for interpreting the $Y$ data, we perform fits to each one, obtaining results that demonstrate differing possibilities for the $P$-wave spectra. Choosing one of these fits for illustration, we predict masses for all 28 isomultiplets in this $1P$ multiplet, compare the results to tantalizing hints in the data, and discuss the rich discovery potential for new states.
1009.3501
David Marsh
David J. E. Marsh and Pedro G. Ferreira
Ultra-Light Scalar Fields and the Growth of Structure in the Universe
12 pages, 11 figures
Phys.Rev.D82:103528,2010
10.1103/PhysRevD.82.103528
OUTP-10-25P
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Ultra-light scalar fields, with masses of between m=10^{-33} eV and m=10^{-22} eV, can affect the growth of structure in the Universe. We identify the different regimes in the evolution of ultra-light scalar fields, how they affect the expansion rate of the universe and how they affect the growth rate of cosmological perturbations. We find a number of interesting effects, discuss how they might arise in realistic scenarios of the early universe and comment on how they might be observed.
[ { "created": "Fri, 17 Sep 2010 20:06:26 GMT", "version": "v1" } ]
2010-12-23
[ [ "Marsh", "David J. E.", "" ], [ "Ferreira", "Pedro G.", "" ] ]
Ultra-light scalar fields, with masses of between m=10^{-33} eV and m=10^{-22} eV, can affect the growth of structure in the Universe. We identify the different regimes in the evolution of ultra-light scalar fields, how they affect the expansion rate of the universe and how they affect the growth rate of cosmological perturbations. We find a number of interesting effects, discuss how they might arise in realistic scenarios of the early universe and comment on how they might be observed.
1207.1246
Prasanta Das Kumar
Prasanta Kumar Das and Abhishodh Prakash
Effect of earth rotation on pair production of Standard Model Higgs bosons at linear colliders in the noncommutative space-time
20 pages, 16 eps figures. arXiv admin note: substantial text overlap with arXiv:1009.3571
Int. J. Mod. Phys. A 28, 1350004 (2013)
10.1142/S0217751X13500048
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the neutral Higgs boson pair production through $e^{+} e^{-}$ collision in the noncommutative(NC) extension of the standard model using the Seiberg-Witten maps of this to the first order of the noncommutative parameter $\Theta_{\mu \nu}$. This process is forbidden in the standard model at the tree level with background space-time being commutative. After including the effects of earth's rotation we analyse the time-averaged cross section of the pair production of Higgs boson (in the light of LEP II and LHC data) at the future Linear Collider which can be quite significant for the NC scale $\Lambda$ lying in the range $0.3 - 1.0$ TeV. For the 125 GeV Higgs mass(the most promising value of Higgs mass as reported by LHC), we find the NC scale as $330 \rm{GeV}$ $\le \Lambda \le 660 \rm{GeV}$ and using $m_h = 129(127.5) \rm{GeV}$ (the lower threshold value of the excluded region of $m_h$ reported by ATLAS(CMS) collaborations of LHC), we find the bound on $\Lambda$ as: (i) $339 (336) \rm{GeV} \le \Lambda \le 677 (670) \rm{GeV}$ corresponding to the Linear Collider energy $E_{com} = 500 \rm{GeV}$.
[ { "created": "Thu, 5 Jul 2012 13:09:39 GMT", "version": "v1" } ]
2014-11-18
[ [ "Das", "Prasanta Kumar", "" ], [ "Prakash", "Abhishodh", "" ] ]
We study the neutral Higgs boson pair production through $e^{+} e^{-}$ collision in the noncommutative(NC) extension of the standard model using the Seiberg-Witten maps of this to the first order of the noncommutative parameter $\Theta_{\mu \nu}$. This process is forbidden in the standard model at the tree level with background space-time being commutative. After including the effects of earth's rotation we analyse the time-averaged cross section of the pair production of Higgs boson (in the light of LEP II and LHC data) at the future Linear Collider which can be quite significant for the NC scale $\Lambda$ lying in the range $0.3 - 1.0$ TeV. For the 125 GeV Higgs mass(the most promising value of Higgs mass as reported by LHC), we find the NC scale as $330 \rm{GeV}$ $\le \Lambda \le 660 \rm{GeV}$ and using $m_h = 129(127.5) \rm{GeV}$ (the lower threshold value of the excluded region of $m_h$ reported by ATLAS(CMS) collaborations of LHC), we find the bound on $\Lambda$ as: (i) $339 (336) \rm{GeV} \le \Lambda \le 677 (670) \rm{GeV}$ corresponding to the Linear Collider energy $E_{com} = 500 \rm{GeV}$.
0911.1006
Fei Wang
Csaba Balazs, Zhaofeng Kang, Tianjun Li, Fei Wang, Jin Min Yang
Realistic Flipped SU(5) from Orbifold SO(10)
25 pages, 1 fig
JHEP 1002:096,2010
10.1007/JHEP02(2010)096
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a realistic flipped SU(5) model derived from a five-dimensional orbifold SO(10) model. The Standard Model (SM) fermion masses and mixings are explained by combining the traditional Froggatt-Nielsen mechanism with the five-dimensional wave function profiles of the SM fermions. Employing tree-level spontaneous R-symmetry breaking in the hidden sector and extra(ordinary) gauge mediation, we obtain realistic supersymmetry breaking soft mass terms with non-vanishing gaugino masses. Including the messenger fields at the intermediate scale and Kaluza-Klein states at the compactification scale, we study gauge coupling unification. We show that the SO(10) unified gauge coupling is very strong and the unification scale can be much higher than the compactification scale. We briefly discuss proton decay as well.
[ { "created": "Thu, 5 Nov 2009 10:28:12 GMT", "version": "v1" } ]
2010-03-02
[ [ "Balazs", "Csaba", "" ], [ "Kang", "Zhaofeng", "" ], [ "Li", "Tianjun", "" ], [ "Wang", "Fei", "" ], [ "Yang", "Jin Min", "" ] ]
We propose a realistic flipped SU(5) model derived from a five-dimensional orbifold SO(10) model. The Standard Model (SM) fermion masses and mixings are explained by combining the traditional Froggatt-Nielsen mechanism with the five-dimensional wave function profiles of the SM fermions. Employing tree-level spontaneous R-symmetry breaking in the hidden sector and extra(ordinary) gauge mediation, we obtain realistic supersymmetry breaking soft mass terms with non-vanishing gaugino masses. Including the messenger fields at the intermediate scale and Kaluza-Klein states at the compactification scale, we study gauge coupling unification. We show that the SO(10) unified gauge coupling is very strong and the unification scale can be much higher than the compactification scale. We briefly discuss proton decay as well.
hep-ph/0109250
Stefan Wolf
Th. Mannel (U. of Karlsruhe), St. Wolf (U. of Valencia)
Non-perturbative effects in semi-leptonic B_c decays
LaTeX, 22 pages, 1 figure
Phys.Rev.D65:074012,2002
10.1103/PhysRevD.65.074012
TTP01-24, FTUV-01-0926
hep-ph
null
We discuss the impact of the soft degrees of freedom inside the B_c meson on its rate in the semi-leptonic decay B_c -> X l nu_l where X denotes light hadrons below the D^0 threshold. In particular we identify contributions involving soft hadrons which are non-vanishing in the limit of massless leptons. These contributions become relevant for a measurement of the purely leptonic B_c decay rate, which due to helicity suppression involves a factor m_l^2 and thus is much smaller than the contributions involving soft hadrons.
[ { "created": "Wed, 26 Sep 2001 17:24:47 GMT", "version": "v1" } ]
2011-03-23
[ [ "Mannel", "Th.", "", "U. of Karlsruhe" ], [ "Wolf", "St.", "", "U. of Valencia" ] ]
We discuss the impact of the soft degrees of freedom inside the B_c meson on its rate in the semi-leptonic decay B_c -> X l nu_l where X denotes light hadrons below the D^0 threshold. In particular we identify contributions involving soft hadrons which are non-vanishing in the limit of massless leptons. These contributions become relevant for a measurement of the purely leptonic B_c decay rate, which due to helicity suppression involves a factor m_l^2 and thus is much smaller than the contributions involving soft hadrons.
0909.2460
Bruce Mellado
T. Han and B. Mellado
Higgs Boson Searches and the Hbbar Coupling at the LHeC
9 pages, 7 figures
Phys.Rev.D82:016009,2010
10.1103/PhysRevD.82.016009
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Once the existence of the Higgs boson is established at the CERN Large Hadron Collider (LHC), the focus will be shifted toward understanding its couplings to other particles. A crucial aspect is the measurement of the bottom Yukawa coupling, which is challenging at the LHC. In this paper we study the use of forward jet tagging as a means to secure the observation and to significantly improve the purity of the Higgs boson signal in the H to bbar decay mode from deep inelastic electron-proton scattering at the LHC. We demonstrate that the requirement of forward jet tagging in charged current events strongly enhances the signal-to-background ratio. The impact of a veto on additional partons is also discussed. Excellent response to hadronic shower and b-tagging capabilities are pivotal detector performance aspects.
[ { "created": "Mon, 14 Sep 2009 02:06:10 GMT", "version": "v1" } ]
2014-11-20
[ [ "Han", "T.", "" ], [ "Mellado", "B.", "" ] ]
Once the existence of the Higgs boson is established at the CERN Large Hadron Collider (LHC), the focus will be shifted toward understanding its couplings to other particles. A crucial aspect is the measurement of the bottom Yukawa coupling, which is challenging at the LHC. In this paper we study the use of forward jet tagging as a means to secure the observation and to significantly improve the purity of the Higgs boson signal in the H to bbar decay mode from deep inelastic electron-proton scattering at the LHC. We demonstrate that the requirement of forward jet tagging in charged current events strongly enhances the signal-to-background ratio. The impact of a veto on additional partons is also discussed. Excellent response to hadronic shower and b-tagging capabilities are pivotal detector performance aspects.
1308.2803
Alex Pomarol
Alex Pomarol and Francesco Riva
Towards the Ultimate SM Fit to Close in on Higgs Physics
20 pages, 5 figures, v2: typos corrected. JHEP version
null
10.1007/JHEP01(2014)151
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the discovery of the Higgs at the LHC, experiments have finally addressed all aspects of the Standard Model (SM). At this stage, it is important to understand which windows for beyond the SM (BSM) physics are still open, and which are instead tightly closed. We address this question by parametrizing BSM effects with dimension-six operators and performing a global fit to the SM. We separate operators into different groups constrained at different levels, and provide independent bounds on their Wilson coefficients taking into account only the relevant experiments. Our analysis allows to assert in a model-independent way where BSM effects can appear in Higgs physics. In particular, we show that deviations from the SM in the differential distributions of h->Vff are related to other observables, such as triple gauge-boson couplings, and are then already constrained by present data. On the contrary, BR(h-> Z+gamma) can still hide large deviations from the SM.
[ { "created": "Tue, 13 Aug 2013 09:51:35 GMT", "version": "v1" }, { "created": "Tue, 28 Jan 2014 14:15:43 GMT", "version": "v2" } ]
2015-06-16
[ [ "Pomarol", "Alex", "" ], [ "Riva", "Francesco", "" ] ]
With the discovery of the Higgs at the LHC, experiments have finally addressed all aspects of the Standard Model (SM). At this stage, it is important to understand which windows for beyond the SM (BSM) physics are still open, and which are instead tightly closed. We address this question by parametrizing BSM effects with dimension-six operators and performing a global fit to the SM. We separate operators into different groups constrained at different levels, and provide independent bounds on their Wilson coefficients taking into account only the relevant experiments. Our analysis allows to assert in a model-independent way where BSM effects can appear in Higgs physics. In particular, we show that deviations from the SM in the differential distributions of h->Vff are related to other observables, such as triple gauge-boson couplings, and are then already constrained by present data. On the contrary, BR(h-> Z+gamma) can still hide large deviations from the SM.
hep-ph/0309254
Troy Andre
Troy C. Andre and Jonathan L. Rosner
Exotic Q=-1/3 Quark Signatures at High-Energy Hadron Colliders
Minor changes to text, converted to Revtex4, 38 pages, 9 figures, to be submitted to Phys. Rev. D
Phys.Rev.D69:035009,2004
10.1103/PhysRevD.69.035009
null
hep-ph
null
Isosinglet vector-like quarks are predicted by some unified theories of electroweak and strong interactions. We study hadron collider signatures for the production and decay of isosinglet vector-like quarks with charge -1/3. Previous analyses of Run I data from the Fermilab Tevatron are used to set lower limits of 100--200 GeV/c^2 on the mass of such quarks, depending on assumptions about mixing with Standard Model quarks and the mass of the Higgs boson. For future Tevatron data (E_{c.m.} = 1.96 TeV) the corresponding mass range is (100-270, 100-320) GeV/c^2 for (1, 10) fb^{-1}. At the CERN Large Hadron Collider (LHC) (E_{c.m.} = 14 TeV, 100 fb^{-1}), an analysis of flavor-changing neutral-current decay modes should probe an $h$ quark mass range of 100-1100 GeV/c^2.
[ { "created": "Mon, 22 Sep 2003 20:56:11 GMT", "version": "v1" }, { "created": "Thu, 2 Oct 2003 22:23:07 GMT", "version": "v2" } ]
2014-11-17
[ [ "Andre", "Troy C.", "" ], [ "Rosner", "Jonathan L.", "" ] ]
Isosinglet vector-like quarks are predicted by some unified theories of electroweak and strong interactions. We study hadron collider signatures for the production and decay of isosinglet vector-like quarks with charge -1/3. Previous analyses of Run I data from the Fermilab Tevatron are used to set lower limits of 100--200 GeV/c^2 on the mass of such quarks, depending on assumptions about mixing with Standard Model quarks and the mass of the Higgs boson. For future Tevatron data (E_{c.m.} = 1.96 TeV) the corresponding mass range is (100-270, 100-320) GeV/c^2 for (1, 10) fb^{-1}. At the CERN Large Hadron Collider (LHC) (E_{c.m.} = 14 TeV, 100 fb^{-1}), an analysis of flavor-changing neutral-current decay modes should probe an $h$ quark mass range of 100-1100 GeV/c^2.
1309.7211
Carlos Hidalgo-Duque
Carlos Hidalgo-Duque, Felipe J. Llanes-Estrada
Soft interactions in jet quenching
14 pages, 16 figures
null
10.1142/S0217751X15500670
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the collisional aspects of jet quenching in a high energy nuclear collision, especially in the final state pion gas. The jet has a large energy, and acquires momentum transverse to its axis more effectively by multiple soft collisions than by few hard scatterings (as known from analogous systems such as J/\psi production at Hera). Such regime of large E and small momentum transfer corresponds to Regge kinematics and is characteristically dominated by the pomeron. From this insight we estimate the jet quenching parameter in the hadron medium (largely a pion gas) at the end of the collision, which is naturally small and increases with temperature in line with the gas density. The physics in the quark-gluon plasma/liquid phase is less obvious, and here we revisit a couple of simple estimates that suggest indeed that the pomeron-mediated interactions are very relevant and should be included in analysis of the jet quenching parameter. Finally, the ocasional hard collisions produce features characteristic of a L\`evy flight in the q_perp^2 plane perpendicular to the jet axis. We suggest one- and two-particle q_perp correlations as interesting experimental probes.
[ { "created": "Fri, 27 Sep 2013 11:53:49 GMT", "version": "v1" }, { "created": "Fri, 4 Oct 2013 07:06:15 GMT", "version": "v2" }, { "created": "Mon, 7 Oct 2013 19:13:12 GMT", "version": "v3" }, { "created": "Thu, 28 Nov 2013 09:49:38 GMT", "version": "v4" }, { "cre...
2015-07-07
[ [ "Hidalgo-Duque", "Carlos", "" ], [ "Llanes-Estrada", "Felipe J.", "" ] ]
We study the collisional aspects of jet quenching in a high energy nuclear collision, especially in the final state pion gas. The jet has a large energy, and acquires momentum transverse to its axis more effectively by multiple soft collisions than by few hard scatterings (as known from analogous systems such as J/\psi production at Hera). Such regime of large E and small momentum transfer corresponds to Regge kinematics and is characteristically dominated by the pomeron. From this insight we estimate the jet quenching parameter in the hadron medium (largely a pion gas) at the end of the collision, which is naturally small and increases with temperature in line with the gas density. The physics in the quark-gluon plasma/liquid phase is less obvious, and here we revisit a couple of simple estimates that suggest indeed that the pomeron-mediated interactions are very relevant and should be included in analysis of the jet quenching parameter. Finally, the ocasional hard collisions produce features characteristic of a L\`evy flight in the q_perp^2 plane perpendicular to the jet axis. We suggest one- and two-particle q_perp correlations as interesting experimental probes.
hep-ph/0210293
Sandy Donnachie
F.E. Close, A. Donnachie and Yu.S. Kalashnikova
Radiative decays: a new flavour filter
12 pages, 1 table, 0 figures
Phys.Rev. D67 (2003) 074031
10.1103/PhysRevD.67.074031
null
hep-ph
null
Radiative decays of the $1^3D_1$ orbital excitations of the $\rho$, $\omega$ and $\phi$ to the scalars $f_0(1370)$, $f_0(1500)$ and $f_0(1710)$ are shown to provide a flavour filter, clarifying the extent of glueball mixing in the scalar states. A complementary approach to the latter is provided by the radiative decays of the scalar mesons to the ground-state vectors $\rho$, $\omega$ and $\phi$. Discrimination among different mixing scenarios is strong.
[ { "created": "Tue, 22 Oct 2002 10:46:50 GMT", "version": "v1" } ]
2009-11-07
[ [ "Close", "F. E.", "" ], [ "Donnachie", "A.", "" ], [ "Kalashnikova", "Yu. S.", "" ] ]
Radiative decays of the $1^3D_1$ orbital excitations of the $\rho$, $\omega$ and $\phi$ to the scalars $f_0(1370)$, $f_0(1500)$ and $f_0(1710)$ are shown to provide a flavour filter, clarifying the extent of glueball mixing in the scalar states. A complementary approach to the latter is provided by the radiative decays of the scalar mesons to the ground-state vectors $\rho$, $\omega$ and $\phi$. Discrimination among different mixing scenarios is strong.
hep-ph/0103219
Ove Scavenius
O. Scavenius, A. Dumitru, A.D. Jackson
Explosive Decomposition in Ultrarelativistic Heavy Ion Collision
5 pages latex and 10 figures, Version accepted for PRL (but page 5 containing additional 6 figures will not appear in PRL)
Phys.Rev.Lett. 87 (2001) 182302
10.1103/PhysRevLett.87.182302
null
hep-ph cond-mat hep-lat nucl-th
null
Recent results from Au+Au collisions at BNL-RHIC energy hint at explosive hadron production at the QCD transition rather than soft hydrodynamic evolution. We speculate that this is due to a rapid variation of the effective potential for QCD close to Tc. Performing real-time lattice simulations of an effective theory we show that the fast evolution of the potential leads to ``explosive'' spinodal decomposition rather than bubble nucleation or critical slowing down.
[ { "created": "Tue, 20 Mar 2001 16:18:27 GMT", "version": "v1" }, { "created": "Thu, 13 Sep 2001 12:03:51 GMT", "version": "v2" } ]
2009-11-07
[ [ "Scavenius", "O.", "" ], [ "Dumitru", "A.", "" ], [ "Jackson", "A. D.", "" ] ]
Recent results from Au+Au collisions at BNL-RHIC energy hint at explosive hadron production at the QCD transition rather than soft hydrodynamic evolution. We speculate that this is due to a rapid variation of the effective potential for QCD close to Tc. Performing real-time lattice simulations of an effective theory we show that the fast evolution of the potential leads to ``explosive'' spinodal decomposition rather than bubble nucleation or critical slowing down.
hep-ph/0102074
Brenna Flaugher
T. Affolder, et al. (CDF Collaboration)
Measurement of the Inclusive Jet Cross Section in ${\bar p p}$ collisions at $\sqrt{s}=1.8$ TeV
123 pages, 46 figures
Phys.Rev.D64:032001,2001; Erratum-ibid.D65:039903,2002
10.1103/PhysRevD.64.032001 10.1103/PhysRevD.65.039903
fnal-pub-01/008-E
hep-ph hep-ex
null
We present results from the measurement of the inclusive jet cross section for jet transverse energies from 40 to 465 GeV in the pseudo-rapidity range $0.1<|\eta|<0.7$. The results are based on 87 $pb^{-1}$ of data collected by the CDF collaboration at the Fermilab Tevatron Collider. The data are consistent with previously published results. The data are also consistent with QCD predictions given the flexibility allowed from current knowledge of the proton parton distributions. We develop a new procedure for ranking the agreement of the parton distributions with data and find that the data are best described by QCD predictions using the parton distribution functions which have a large gluon contribution at high $E_T$ (CTEQ4HJ).
[ { "created": "Tue, 6 Feb 2001 23:05:13 GMT", "version": "v1" } ]
2014-11-17
[ [ "Affolder", "T.", "" ] ]
We present results from the measurement of the inclusive jet cross section for jet transverse energies from 40 to 465 GeV in the pseudo-rapidity range $0.1<|\eta|<0.7$. The results are based on 87 $pb^{-1}$ of data collected by the CDF collaboration at the Fermilab Tevatron Collider. The data are consistent with previously published results. The data are also consistent with QCD predictions given the flexibility allowed from current knowledge of the proton parton distributions. We develop a new procedure for ranking the agreement of the parton distributions with data and find that the data are best described by QCD predictions using the parton distribution functions which have a large gluon contribution at high $E_T$ (CTEQ4HJ).
hep-ph/0601236
Andrew Cohen
Andrew G. Cohen and Sheldon L. Glashow
Very Special Relativity
3 pages, revtex
Phys.Rev.Lett. 97 (2006) 021601
10.1103/PhysRevLett.97.021601
null
hep-ph
null
By Very Special Relativity (VSR) we mean descriptions of nature whose space-time symmetries are certain proper subgroups of the Poincar\'e group. These subgroups contain space-time translations together with at least a 2-parameter subgroup of the Lorentz group isomorphic to that generated by $K_{x}+J_{y}$ and $K_{y}-J_{x}$. We find that VSR implies special relativity (SR) in the context of local quantum field theory or of CP conservation. Absent both of these added hypotheses, VSR provides a simulacrum of SR for which most of the consequences of Lorentz invariance remain wholly or essentially intact, and for which many sensitive searches for departures from Lorentz invariance must fail. Several feasible experiments are discussed for which Lorentz-violating effects in VSR may be detectable.
[ { "created": "Fri, 27 Jan 2006 21:27:43 GMT", "version": "v1" } ]
2009-11-11
[ [ "Cohen", "Andrew G.", "" ], [ "Glashow", "Sheldon L.", "" ] ]
By Very Special Relativity (VSR) we mean descriptions of nature whose space-time symmetries are certain proper subgroups of the Poincar\'e group. These subgroups contain space-time translations together with at least a 2-parameter subgroup of the Lorentz group isomorphic to that generated by $K_{x}+J_{y}$ and $K_{y}-J_{x}$. We find that VSR implies special relativity (SR) in the context of local quantum field theory or of CP conservation. Absent both of these added hypotheses, VSR provides a simulacrum of SR for which most of the consequences of Lorentz invariance remain wholly or essentially intact, and for which many sensitive searches for departures from Lorentz invariance must fail. Several feasible experiments are discussed for which Lorentz-violating effects in VSR may be detectable.
hep-ph/0305085
T. L. Trueman
T.L. Trueman (BNL)
Proton-carbon CNI polarimetry and the spin-dependence of the Pomeron
null
null
null
null
hep-ph
null
Recent polarized proton experiments at Brookhaven National Laboratory are used as a basis for a model of the energy dependence of the analyzing power of proton-carbon elastic scattering. In addition to their practical value for polarimetry, the results of this analysis give constraints on the size of the Pomeron spin-flip coupling as well as information on the $f_2$ and $\omega$ spin-flip couplings.
[ { "created": "Thu, 8 May 2003 14:46:32 GMT", "version": "v1" } ]
2007-05-23
[ [ "Trueman", "T. L.", "", "BNL" ] ]
Recent polarized proton experiments at Brookhaven National Laboratory are used as a basis for a model of the energy dependence of the analyzing power of proton-carbon elastic scattering. In addition to their practical value for polarimetry, the results of this analysis give constraints on the size of the Pomeron spin-flip coupling as well as information on the $f_2$ and $\omega$ spin-flip couplings.
2208.08020
Jayden Newstead
Nicole F. Bell, James B. Dent, Bhaskar Dutta, Jason Kumar, Jayden L. Newstead
Low-Mass dark matter (in)direct detection with inelastic scattering
8 pages, 8 figures (appendix added with more detail)
Phys. Rev. D 106, 103016 (2022)
10.1103/PhysRevD.106.103016
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We revisit the detection of luminous dark matter in direct detection experiments. In this scenario, dark matter scatters endothermically to produce an excited state, which decays to produce a photon. We explore ways in which the electron recoil signal from the decay photon can be differentiated from other potential electron recoil signals with a narrow spectral shape. We find that larger volume/exposure xenon detectors will be unable to differentiate the signal origin without significant improvements in detector energy resolution of around an order of magnitude. We also explore what can be learned about a generic luminous dark matter signal with a higher resolution detector. Motivated by the advancements in energy resolution by solid-state detectors, we find that sub-eV resolution enables the discovery of LDM in the presence of background levels that would otherwise make observation impossible. We also find that sub-eV resolution can be used to determine the shape of the luminous dark matter decay spectrum and thus constrain the dark matter mass and velocity distribution.
[ { "created": "Wed, 17 Aug 2022 02:03:28 GMT", "version": "v1" }, { "created": "Tue, 15 Nov 2022 23:51:04 GMT", "version": "v2" } ]
2022-11-17
[ [ "Bell", "Nicole F.", "" ], [ "Dent", "James B.", "" ], [ "Dutta", "Bhaskar", "" ], [ "Kumar", "Jason", "" ], [ "Newstead", "Jayden L.", "" ] ]
We revisit the detection of luminous dark matter in direct detection experiments. In this scenario, dark matter scatters endothermically to produce an excited state, which decays to produce a photon. We explore ways in which the electron recoil signal from the decay photon can be differentiated from other potential electron recoil signals with a narrow spectral shape. We find that larger volume/exposure xenon detectors will be unable to differentiate the signal origin without significant improvements in detector energy resolution of around an order of magnitude. We also explore what can be learned about a generic luminous dark matter signal with a higher resolution detector. Motivated by the advancements in energy resolution by solid-state detectors, we find that sub-eV resolution enables the discovery of LDM in the presence of background levels that would otherwise make observation impossible. We also find that sub-eV resolution can be used to determine the shape of the luminous dark matter decay spectrum and thus constrain the dark matter mass and velocity distribution.
hep-ph/0405253
Genevieve Belanger
G. Belanger, F. Boudjema, A. Pukhov, A. Semenov
micrOMEGAs: Version 1.3
45 pages
Comput.Phys.Commun.174:577-604,2006
10.1016/j.cpc.2005.12.005
LAPTH-1044
hep-ph
null
We present the latest version of micromegas, a code that calculates the relic density of the lightest supersymmetric particle in the MSSM. All tree-level processes for the annihilation of the LSP are included as well as all possible coannihilation processes with neutralinos, charginos, sleptons, squarks and gluinos. The cross-sections extracted from CalcHEP are calculated exactly using loop-corrected masses and mixings as specified in the SUSY Les Houches Accord. Relativistic formulae for the thermal average are used and care is taken to handle poles and thresholds by adopting specific integration routines. The input parameters can be either the soft SUSY parameters in a general MSSM or the parameters of a SUGRA model specified at some high scale (GUT). In the latter case, a link with Suspect, Softsusy, Spheno and Isajet allows to calculate the supersymmetric spectrum, Higgs masses, as well as mixing matrices. Higher-order corrections to Higgs couplings to quark pairs including QCD as well as some SUSY corrections (deltaMb) are implemented. Routines calculating (g-2), bsgamma and bsmumu are also included. In particular the bsgamma routine includes an improved NLO for the SM and the charged Higgs while the SUSY large tan(beta) effects beyond leading-order are included. This new version also provides cross-sections for any 2->2 process as well as partial decay widths for two-body final states in the MSSM allowing for easy simulation at colliders.
[ { "created": "Tue, 25 May 2004 16:36:30 GMT", "version": "v1" } ]
2008-11-26
[ [ "Belanger", "G.", "" ], [ "Boudjema", "F.", "" ], [ "Pukhov", "A.", "" ], [ "Semenov", "A.", "" ] ]
We present the latest version of micromegas, a code that calculates the relic density of the lightest supersymmetric particle in the MSSM. All tree-level processes for the annihilation of the LSP are included as well as all possible coannihilation processes with neutralinos, charginos, sleptons, squarks and gluinos. The cross-sections extracted from CalcHEP are calculated exactly using loop-corrected masses and mixings as specified in the SUSY Les Houches Accord. Relativistic formulae for the thermal average are used and care is taken to handle poles and thresholds by adopting specific integration routines. The input parameters can be either the soft SUSY parameters in a general MSSM or the parameters of a SUGRA model specified at some high scale (GUT). In the latter case, a link with Suspect, Softsusy, Spheno and Isajet allows to calculate the supersymmetric spectrum, Higgs masses, as well as mixing matrices. Higher-order corrections to Higgs couplings to quark pairs including QCD as well as some SUSY corrections (deltaMb) are implemented. Routines calculating (g-2), bsgamma and bsmumu are also included. In particular the bsgamma routine includes an improved NLO for the SM and the charged Higgs while the SUSY large tan(beta) effects beyond leading-order are included. This new version also provides cross-sections for any 2->2 process as well as partial decay widths for two-body final states in the MSSM allowing for easy simulation at colliders.
2007.10343
Jessica Turner
Stefan Hoeche, Jonathan Kozaczuk, Andrew J. Long, Jessica Turner and Yikun Wang
Towards an all-orders calculation of the electroweak bubble wall velocity
One minor typo removed on page 7 and one reference updated
null
10.1088/1475-7516/2021/03/009
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze Higgs condensate bubble expansion during a first-order electroweak phase transition in the early Universe. The interaction of particles with the bubble wall can be accompanied by the emission of multiple soft gauge bosons. When computed at fixed order in perturbation theory, this process exhibits large logarithmic enhancements which must be resummed to all orders when the wall velocity is large. We perform this resummation both analytically and numerically at leading logarithmic accuracy. The numerical simulation is achieved by means of a particle shower in the broken phase of the electroweak theory. The two approaches agree to the 10\% level. For fast-moving walls, we find the scaling of the thermal pressure exerted against the wall to be $P\sim \gamma^2T^4$, independent of the particle masses, implying a significantly slower terminal velocity than previously suggested.
[ { "created": "Mon, 20 Jul 2020 18:00:01 GMT", "version": "v1" }, { "created": "Wed, 30 Sep 2020 15:08:32 GMT", "version": "v2" }, { "created": "Mon, 8 Feb 2021 14:24:04 GMT", "version": "v3" }, { "created": "Tue, 16 Mar 2021 10:03:22 GMT", "version": "v4" } ]
2021-03-17
[ [ "Hoeche", "Stefan", "" ], [ "Kozaczuk", "Jonathan", "" ], [ "Long", "Andrew J.", "" ], [ "Turner", "Jessica", "" ], [ "Wang", "Yikun", "" ] ]
We analyze Higgs condensate bubble expansion during a first-order electroweak phase transition in the early Universe. The interaction of particles with the bubble wall can be accompanied by the emission of multiple soft gauge bosons. When computed at fixed order in perturbation theory, this process exhibits large logarithmic enhancements which must be resummed to all orders when the wall velocity is large. We perform this resummation both analytically and numerically at leading logarithmic accuracy. The numerical simulation is achieved by means of a particle shower in the broken phase of the electroweak theory. The two approaches agree to the 10\% level. For fast-moving walls, we find the scaling of the thermal pressure exerted against the wall to be $P\sim \gamma^2T^4$, independent of the particle masses, implying a significantly slower terminal velocity than previously suggested.
hep-ph/0502216
Tomoki Endo
Tomoki Endo, Toshiki Maruyama, Satoshi Chiba and Toshitaka Tatsumi
Hadron-quark matter phase transition in neutron stars
17 pages, 16 figures, Lecture note of "Hot points in Astrophysics and Cosmology"
null
null
null
hep-ph
null
A structured mixed phase consisting of quark and hadron phases is numerically studied with the Coulomb screening effect and the surface effect. We carefully introduced the Coulomb potential, so that a geometrical structure becomes mechanically unstable when the surface tension is large. Charge densities are largely rearranged by the screening effect, and thereby the equation of state shows the similar behavior to that given by the Maxwell construction. Therefore, although bulk calculations with the Gibbs conditions show that the mixed phase may exist in a wide density region, we can see it is restricted to a narrow density region by the surface effect and the Coulomb screening effect.
[ { "created": "Wed, 23 Feb 2005 11:10:43 GMT", "version": "v1" }, { "created": "Thu, 3 Mar 2005 05:58:25 GMT", "version": "v2" } ]
2007-05-23
[ [ "Endo", "Tomoki", "" ], [ "Maruyama", "Toshiki", "" ], [ "Chiba", "Satoshi", "" ], [ "Tatsumi", "Toshitaka", "" ] ]
A structured mixed phase consisting of quark and hadron phases is numerically studied with the Coulomb screening effect and the surface effect. We carefully introduced the Coulomb potential, so that a geometrical structure becomes mechanically unstable when the surface tension is large. Charge densities are largely rearranged by the screening effect, and thereby the equation of state shows the similar behavior to that given by the Maxwell construction. Therefore, although bulk calculations with the Gibbs conditions show that the mixed phase may exist in a wide density region, we can see it is restricted to a narrow density region by the surface effect and the Coulomb screening effect.
1112.5646
Andras Ster
B\'ela Luk\'acs and Andr\'as Ster
Entropy Production and Particle Yields in Heavy Ion Collisions at LHC
Presented at the 12th Zim\'anyi Winter School on Relativistic Heavy Ion Collisions, December 3-7, 2012. Supported by OTKA NK 101438
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A scheme is proposed for calculating the entropy production in highly transparent colliding systems. The formalism is continuum physical and fully conform with thermodynamics; and the calculation is explicit in entropy production. We have analyzed high energy heavy ion collisions from view point of thermodynamics. Entropy densities are calculated for reactions up 14 TeV energies. Final state particle productions are predicted using particle generating quark and hadron models. We find that at LHC energy the entropy density is 67.8. From this value we could predict particle yields, too. The results show that there is not yet asymptotic freedom.
[ { "created": "Fri, 23 Dec 2011 19:50:52 GMT", "version": "v1" }, { "created": "Mon, 2 Jul 2012 17:30:49 GMT", "version": "v2" }, { "created": "Thu, 15 Nov 2012 00:31:40 GMT", "version": "v3" }, { "created": "Tue, 26 Apr 2016 22:32:43 GMT", "version": "v4" } ]
2016-04-28
[ [ "Lukács", "Béla", "" ], [ "Ster", "András", "" ] ]
A scheme is proposed for calculating the entropy production in highly transparent colliding systems. The formalism is continuum physical and fully conform with thermodynamics; and the calculation is explicit in entropy production. We have analyzed high energy heavy ion collisions from view point of thermodynamics. Entropy densities are calculated for reactions up 14 TeV energies. Final state particle productions are predicted using particle generating quark and hadron models. We find that at LHC energy the entropy density is 67.8. From this value we could predict particle yields, too. The results show that there is not yet asymptotic freedom.
hep-ph/9610332
Samuel Wallon
S. Wallon
QCD dipole predictions for quark singlet, gluon and $F_L/F_T$ distributions at HERA
10 pages, latex file, 4 figures Talk given at the XXXIth Rencontres de Moriond QCD and High Energy Hadronic Interactions March 23-30, 1996, Les Arcs, France
null
null
Saclay preprint SPhT T96/048
hep-ph
null
In this contribution we apply the QCD dipole picture combined with $k_T$-factorization to get predictions for deep-inelastic scattering on an onium. Assuming renormalization-group factorization, we get predictions for the $F_2, F_G$ and $R= F_L/F_T$ proton structure functions. We obtain a three-parameter fit of the 1994 H1 data in the low-$x_{bj}$, moderate-$Q^2$ range. $F_G/F_2$ and $R$ are then predicted without any additionnal parameter. The BFKL dynamics contained in the dipole model is shown to provide a relevant model in describing the HERA data. The prediction for $F_2$ and $F_G$ are compatible with next-to-leading order DGLAP analysis. By contrast, $R$ is expected to be much lower at small $x_{bj}$.
[ { "created": "Fri, 11 Oct 1996 15:02:42 GMT", "version": "v1" } ]
2007-05-23
[ [ "Wallon", "S.", "" ] ]
In this contribution we apply the QCD dipole picture combined with $k_T$-factorization to get predictions for deep-inelastic scattering on an onium. Assuming renormalization-group factorization, we get predictions for the $F_2, F_G$ and $R= F_L/F_T$ proton structure functions. We obtain a three-parameter fit of the 1994 H1 data in the low-$x_{bj}$, moderate-$Q^2$ range. $F_G/F_2$ and $R$ are then predicted without any additionnal parameter. The BFKL dynamics contained in the dipole model is shown to provide a relevant model in describing the HERA data. The prediction for $F_2$ and $F_G$ are compatible with next-to-leading order DGLAP analysis. By contrast, $R$ is expected to be much lower at small $x_{bj}$.
1307.2625
Matthias Burkardt
Lekha Adhikari and Matthias Burkardt
Distribution of Angular Momentum in the Transverse Plane
Proceedings: Light Cone 2012 Delhi
null
10.1016/j.nuclphysbps.2014.04.018
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Fourier transforms of GPDs describe the distribution of partons in the transverse plane. The 2nd moment of GPDs has been identified by X.Ji with the angular momentum (orbital plus spin) carried by the quarks - a fundamental result that is being widely utilized in the spin decomposition of a longitudinally polarized nucleon. However, I will demonstrate that, despite the above results, the Fourier transform of the 2nd moment of GPDs does not describe the distribution of angular momentum in the transverse plane for a longitudinally polarized target.
[ { "created": "Tue, 9 Jul 2013 23:23:27 GMT", "version": "v1" } ]
2015-06-16
[ [ "Adhikari", "Lekha", "" ], [ "Burkardt", "Matthias", "" ] ]
Fourier transforms of GPDs describe the distribution of partons in the transverse plane. The 2nd moment of GPDs has been identified by X.Ji with the angular momentum (orbital plus spin) carried by the quarks - a fundamental result that is being widely utilized in the spin decomposition of a longitudinally polarized nucleon. However, I will demonstrate that, despite the above results, the Fourier transform of the 2nd moment of GPDs does not describe the distribution of angular momentum in the transverse plane for a longitudinally polarized target.
1310.2218
Marlene Nahrgang
Marlene Nahrgang, J\"org Aichelin, Pol Bernard Gossiaux, Klaus Werner
Heavy-flavor azimuthal correlations of D mesons
final version of proceedings for SQM 2013, C13-07-22.1
null
10.1088/1742-6596/509/1/012047
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Observables of heavy-quark azimuthal correlations in heavy-ion collisions are a new and promising tool for the investigation of the in-medium energy loss. We explore the potential of these observables to discriminate the collisional and radiative contributions within a hybrid EPOS+MC@sHQ transport approach.
[ { "created": "Tue, 8 Oct 2013 18:31:21 GMT", "version": "v1" }, { "created": "Tue, 15 Jul 2014 17:44:25 GMT", "version": "v2" } ]
2015-06-17
[ [ "Nahrgang", "Marlene", "" ], [ "Aichelin", "Jörg", "" ], [ "Gossiaux", "Pol Bernard", "" ], [ "Werner", "Klaus", "" ] ]
Observables of heavy-quark azimuthal correlations in heavy-ion collisions are a new and promising tool for the investigation of the in-medium energy loss. We explore the potential of these observables to discriminate the collisional and radiative contributions within a hybrid EPOS+MC@sHQ transport approach.
1705.00592
Shu-Yu Ho
Shu-Yu Ho, Takashi Toma, Koji Tsumura
A Radiative Neutrino Mass Model with SIMP Dark Matter
19 pages, 8 figures, 2 tables, expanded, new appendix added, new references added, updated plots, fixed minor typos, matches journal version
JHEP 1707 (2017) 101
10.1007/JHEP07(2017)101
KUNS-2675, TUM-HEP/1082/17
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose the first viable radiative seesaw model, in which the neutrino masses are induced radiatively via the two-loop Feynman diagram involving Strongly Interacting Massive Particles (SIMP). The stability of SIMP dark matter (DM) is ensured by a $\mathbb{Z}_5$ discrete symmetry, through which the DM annihilation rate is dominated by the $3 \to 2$ self-annihilating processes. The right amount of thermal relic abundance can be obtained with perturbative couplings in the resonant SIMP scenario, while the astrophysical bounds inferred from the Bullet cluster and spherical halo shapes can be satisfied. We show that SIMP DM is able to maintain kinetic equilibrium with thermal plasma until the freeze-out temperature via the Yukawa interactions associated with neutrino mass generation.
[ { "created": "Mon, 1 May 2017 16:59:02 GMT", "version": "v1" }, { "created": "Thu, 27 Jul 2017 05:11:33 GMT", "version": "v2" } ]
2017-07-28
[ [ "Ho", "Shu-Yu", "" ], [ "Toma", "Takashi", "" ], [ "Tsumura", "Koji", "" ] ]
We propose the first viable radiative seesaw model, in which the neutrino masses are induced radiatively via the two-loop Feynman diagram involving Strongly Interacting Massive Particles (SIMP). The stability of SIMP dark matter (DM) is ensured by a $\mathbb{Z}_5$ discrete symmetry, through which the DM annihilation rate is dominated by the $3 \to 2$ self-annihilating processes. The right amount of thermal relic abundance can be obtained with perturbative couplings in the resonant SIMP scenario, while the astrophysical bounds inferred from the Bullet cluster and spherical halo shapes can be satisfied. We show that SIMP DM is able to maintain kinetic equilibrium with thermal plasma until the freeze-out temperature via the Yukawa interactions associated with neutrino mass generation.
hep-ph/9912479
null
J.J.M. Verbaarschot
Chiral Symmetry and the Low-Energy Spectrum of the QCD Dirac Operator
Invited talk at XVth PANIC conference, June 10-16, Uppsala, 5 pages, Latex
Nucl.Phys. A663 (2000) 1023-1026
10.1016/S0375-9474(99)00760-5
SUNY NTG-99/49
hep-ph
null
The order parameter of the chiral phase transition is directly related to the infrared part of the spectrum of the QCD Dirac operator. This part of the spectrum follows from the low energy limit of QCD which is given by a partition function of weakly interacting Goldstone modes. We find that the slope of the Dirac spectrum is determined by the pion decay constant whereas for $\lambda \ll 1/L^2 \Lambda_{\rm QCD}$ the correlations of the Dirac eigenvalues are given by a random matrix theory with the global symmetries of the QCD partition function. A possible observation of these continuum results in lattice QCD with staggered fermions is discussed.
[ { "created": "Wed, 22 Dec 1999 17:38:42 GMT", "version": "v1" } ]
2009-10-31
[ [ "Verbaarschot", "J. J. M.", "" ] ]
The order parameter of the chiral phase transition is directly related to the infrared part of the spectrum of the QCD Dirac operator. This part of the spectrum follows from the low energy limit of QCD which is given by a partition function of weakly interacting Goldstone modes. We find that the slope of the Dirac spectrum is determined by the pion decay constant whereas for $\lambda \ll 1/L^2 \Lambda_{\rm QCD}$ the correlations of the Dirac eigenvalues are given by a random matrix theory with the global symmetries of the QCD partition function. A possible observation of these continuum results in lattice QCD with staggered fermions is discussed.
2402.19208
Xing-Bo Yuan
Biao-Feng Hou, Xin-Qiang Li, Meng Shen, Ya-Dong Yang, Xing-Bo Yuan
Deciphering the Belle II data on $B\to K \nu \bar\nu$ decay in the (dark) SMEFT with minimal flavour violation
51 pages, 13 figures, comments welcome; v2: discussions on $F_L$ of the $B \to K^* + \text{inv}$ decay in the DSMEFT added, errors in the $B \to V + \text{inv}$ decays for some operators involving two scalar or vector DM fields fixed, the related discussions and figures 2, 6, 7, 11 and 12 corrected, main conclusion unchanged, a few comments and refs added
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
Recently, the Belle II collaboration announced the first measurement of $\mathcal B(B^+\to K^+\nu\bar\nu)$, which is found to be about $2.7\sigma$ higher than the SM prediction. We decipher the data with two new physics scenarios: the underlying $b\to s \nu\bar\nu$ transition is, besides the SM contribution, further affected by heavy new mediators that are much heavier than the EW scale, or amended by an additional decay channel with undetected light final states like dark matter or axion-like particles. These two scenarios can be most conveniently analyzed in the SMEFT and the dark SMEFT (DSMEFT) framework, respectively. We consider the flavour structures of the resulting effective operators to be either generic or satisfy the minimal flavour violation (MFV) hypothesis, both for the quark and lepton sectors. In the first scenario, once the MFV is assumed, only one SM-like low-energy effective operator induced by the SMEFT dim-6 operators can account for the Belle II excess, the parameter space of which is, however, excluded by the Belle upper bound on $\mathcal B(B^0\to K^{*0}\nu\bar\nu)$. In the second scenario, it is found that the Belle II excess can be accommodated by 22 of the DSMEFT operators involving one or two scalar, fermionic, or vector dark matters as well as ALPs. These operators also receive dominant constraints from the $B^0\to K^{*0}+$inv and $B_s\to$inv decays. In the MFV hypothesis, the number of viable operators is reduced to 14, and the $B^+\to\pi^+ +$inv and $K^+\to\pi^++$inv decays start to put further constraints. Within the parameter space allowed by all the current experimental data, the $q^2$ distributions (and $F_L$) of the $B\to K^{(*)}+$inv decays are studied for each viable operator. In addition, we, for the first time, calculate systematically the longitudinal polarization fraction $F_L$ of $K^*$ in the $B\to K^*+$inv decays within the DLEFT.
[ { "created": "Thu, 29 Feb 2024 14:37:57 GMT", "version": "v1" }, { "created": "Thu, 14 Mar 2024 15:41:19 GMT", "version": "v2" } ]
2024-03-15
[ [ "Hou", "Biao-Feng", "" ], [ "Li", "Xin-Qiang", "" ], [ "Shen", "Meng", "" ], [ "Yang", "Ya-Dong", "" ], [ "Yuan", "Xing-Bo", "" ] ]
Recently, the Belle II collaboration announced the first measurement of $\mathcal B(B^+\to K^+\nu\bar\nu)$, which is found to be about $2.7\sigma$ higher than the SM prediction. We decipher the data with two new physics scenarios: the underlying $b\to s \nu\bar\nu$ transition is, besides the SM contribution, further affected by heavy new mediators that are much heavier than the EW scale, or amended by an additional decay channel with undetected light final states like dark matter or axion-like particles. These two scenarios can be most conveniently analyzed in the SMEFT and the dark SMEFT (DSMEFT) framework, respectively. We consider the flavour structures of the resulting effective operators to be either generic or satisfy the minimal flavour violation (MFV) hypothesis, both for the quark and lepton sectors. In the first scenario, once the MFV is assumed, only one SM-like low-energy effective operator induced by the SMEFT dim-6 operators can account for the Belle II excess, the parameter space of which is, however, excluded by the Belle upper bound on $\mathcal B(B^0\to K^{*0}\nu\bar\nu)$. In the second scenario, it is found that the Belle II excess can be accommodated by 22 of the DSMEFT operators involving one or two scalar, fermionic, or vector dark matters as well as ALPs. These operators also receive dominant constraints from the $B^0\to K^{*0}+$inv and $B_s\to$inv decays. In the MFV hypothesis, the number of viable operators is reduced to 14, and the $B^+\to\pi^+ +$inv and $K^+\to\pi^++$inv decays start to put further constraints. Within the parameter space allowed by all the current experimental data, the $q^2$ distributions (and $F_L$) of the $B\to K^{(*)}+$inv decays are studied for each viable operator. In addition, we, for the first time, calculate systematically the longitudinal polarization fraction $F_L$ of $K^*$ in the $B\to K^*+$inv decays within the DLEFT.
2104.12155
Zhun Lu
Hui Li, Xiaoyu Wang, Zhun Lu
$\sin (\phi_\Lambda-\phi_S)$ azimuthal asymmetry in transversely polarized $\Lambda$ production in SIDIS within TMD factorization at EIC
11 pages, 2 figures. arXiv admin note: text overlap with arXiv:2009.07193
Phys. Rev. D 104, 034020 (2021)
10.1103/PhysRevD.104.034020
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the $\sin (\phi_\Lambda-\phi_S)$ single-spin asymmetry in the transversely polarized $\Lambda$ production in semi-inclusive deeply inelastic scattering process within the framework of the transverse momentum dependent~(TMD) factorization. The asymmetry is contributed by the convolution of the polarizing TMD fragmentation function $D_{1T}^\perp$ of the $\Lambda$ hyperon and the unpolarized TMD distribution function $f_1$ of the target nucleon. We apply two sets of $D_{1T}^{\perp,\Lambda^\uparrow/q}$, the spectator diquark model result and available parametrization, to numerically estimate the $\sin (\phi_\Lambda-\phi_S)$ asymmetry at the kinematical region of electron ion collider (EIC). We take into account the TMD evolution effect in order to include the scale dependence of the TMD distribution functions and fragmentation functions. It is found that different sets of $D_{1T}^{\perp,\Lambda^\uparrow/q}$ lead to different ${\sin (\phi_\Lambda-\phi_S)}$ asymmetry, particularly in sign. Future measurements on the $\sin (\phi_\Lambda-\phi_S)$ asymmetry with high precision at EIC can provide important cross check on the available $\Lambda$ polarizing fragmentation functions as well as constrain them more stringently.
[ { "created": "Sun, 25 Apr 2021 13:23:31 GMT", "version": "v1" } ]
2021-08-25
[ [ "Li", "Hui", "" ], [ "Wang", "Xiaoyu", "" ], [ "Lu", "Zhun", "" ] ]
We investigate the $\sin (\phi_\Lambda-\phi_S)$ single-spin asymmetry in the transversely polarized $\Lambda$ production in semi-inclusive deeply inelastic scattering process within the framework of the transverse momentum dependent~(TMD) factorization. The asymmetry is contributed by the convolution of the polarizing TMD fragmentation function $D_{1T}^\perp$ of the $\Lambda$ hyperon and the unpolarized TMD distribution function $f_1$ of the target nucleon. We apply two sets of $D_{1T}^{\perp,\Lambda^\uparrow/q}$, the spectator diquark model result and available parametrization, to numerically estimate the $\sin (\phi_\Lambda-\phi_S)$ asymmetry at the kinematical region of electron ion collider (EIC). We take into account the TMD evolution effect in order to include the scale dependence of the TMD distribution functions and fragmentation functions. It is found that different sets of $D_{1T}^{\perp,\Lambda^\uparrow/q}$ lead to different ${\sin (\phi_\Lambda-\phi_S)}$ asymmetry, particularly in sign. Future measurements on the $\sin (\phi_\Lambda-\phi_S)$ asymmetry with high precision at EIC can provide important cross check on the available $\Lambda$ polarizing fragmentation functions as well as constrain them more stringently.
1205.5681
Toshihiko Ota
Shinya Kanemura, Yoshitaka Kuno, Toshihiko Ota
Search for Lepton Number Violating Charged Current Processes with Neutrino Beams
4 pages, 5 eps files
null
10.1016/j.physletb.2013.01.029
UT-HET 068; MPP-2012-89
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a new idea to test a class of loop-induced neutrino mass mechanisms by searching for lepton number violating charged current processes with incident of a neutrino beam. The expected rates of these processes are estimated based on some theoretical assumptions. They turn out to be sizable so that detection of such processes could be possible at near detectors in future highly intense neutrino-beam facilities.
[ { "created": "Fri, 25 May 2012 12:39:15 GMT", "version": "v1" } ]
2015-06-05
[ [ "Kanemura", "Shinya", "" ], [ "Kuno", "Yoshitaka", "" ], [ "Ota", "Toshihiko", "" ] ]
We propose a new idea to test a class of loop-induced neutrino mass mechanisms by searching for lepton number violating charged current processes with incident of a neutrino beam. The expected rates of these processes are estimated based on some theoretical assumptions. They turn out to be sizable so that detection of such processes could be possible at near detectors in future highly intense neutrino-beam facilities.
hep-ph/9509323
null
Edi Halyo
Gauge Coupling Unification due to Large String Threshold Corrections
14 pages, uses phyzzx.tex
null
null
WIS-95/36/AUG-PH
hep-ph
null
We show that large string threshold corrections can reconcile the string and MSSM unification scales in fermionic strings. This requires at least three moduli with large VEVs which are different from each other and MSSM states arising in an unconventional manner from the string spectrum. The former is easily achieved by supersymmetry breaking by both hidden gaugino and matter condensation whereas the latter needs to be seen in explicit string models.
[ { "created": "Mon, 18 Sep 1995 20:45:06 GMT", "version": "v1" } ]
2007-05-23
[ [ "Halyo", "Edi", "" ] ]
We show that large string threshold corrections can reconcile the string and MSSM unification scales in fermionic strings. This requires at least three moduli with large VEVs which are different from each other and MSSM states arising in an unconventional manner from the string spectrum. The former is easily achieved by supersymmetry breaking by both hidden gaugino and matter condensation whereas the latter needs to be seen in explicit string models.
0710.1294
Jean-Philippe Lansberg
J.P. Lansberg, B. Pire, L. Szymanowski
Transition Distribution Amplitudes for gamma* gamma collisions
Talk given at International Conference on the Structure and Interactions of the Photon (Photon 2007), 9-13 Jul 2007, Paris, France; 4 pages, 5 figures, uses photon2007.cls (included)
Nucl.Phys.Proc.Suppl.184:239-242,2008
10.1016/j.nuclphysbps.2008.09.172
null
hep-ph hep-ex nucl-th
null
We study the exclusive production of pi-pi and rho-pi in hard gamma* gamma scattering in the forward kinematical region where the virtuality of one photon provides us with a hard scale in the process. The newly introduced concept of Transition Distribution Amplitudes (TDA) is used to perform a QCD calculation of these reactions thanks to two simple models for TDAs. The sizable cross sections for rho-pi and pi-pi production may be tested at intense electron-positron colliders such as CLEO and B factories (Belle and BaBar).
[ { "created": "Fri, 5 Oct 2007 19:16:59 GMT", "version": "v1" } ]
2008-12-18
[ [ "Lansberg", "J. P.", "" ], [ "Pire", "B.", "" ], [ "Szymanowski", "L.", "" ] ]
We study the exclusive production of pi-pi and rho-pi in hard gamma* gamma scattering in the forward kinematical region where the virtuality of one photon provides us with a hard scale in the process. The newly introduced concept of Transition Distribution Amplitudes (TDA) is used to perform a QCD calculation of these reactions thanks to two simple models for TDAs. The sizable cross sections for rho-pi and pi-pi production may be tested at intense electron-positron colliders such as CLEO and B factories (Belle and BaBar).
1512.04928
Simon Knapen
Simon Knapen, Tom Melia, Michele Papucci, Kathryn Zurek
Rays of light from the LHC
20 pages, 9 figures. Typos corrected, appendix A updated and references added
Phys. Rev. D 93, 075020 (2016)
10.1103/PhysRevD.93.075020
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider models for the di-photon resonance observed at ATLAS (with 3.6 fb^{-1}) and CMS (with 2.6 fb^{-1}). We find there is no conflict between the signal reported at 13 TeV, and the constraints from both experiments at 8 TeV with 20.3 fb^{-1}. We make a simple argument for why adding only one new resonance to the standard model (SM) is not sufficient to explain the observation. We explore four viable options: (i): resonance production and decay through loops of messenger fermions or scalars; (ii): a resonant messenger which decays to the di-photon resonance + X; (iii): an edge configuration where A -> B gamma -> C gamma gamma, and (iv): Hidden Valley-like models where the resonance decays to a pair of very light (sub-GeV) states, each of which in turn decays to a pair of collimated photons that cannot be distinguished from a single photon. Since in each case multiple new states have been introduced, a wealth of signatures is expected to ensue at Run-2 of LHC.
[ { "created": "Tue, 15 Dec 2015 20:44:08 GMT", "version": "v1" }, { "created": "Wed, 13 Jan 2016 22:48:04 GMT", "version": "v2" } ]
2016-04-20
[ [ "Knapen", "Simon", "" ], [ "Melia", "Tom", "" ], [ "Papucci", "Michele", "" ], [ "Zurek", "Kathryn", "" ] ]
We consider models for the di-photon resonance observed at ATLAS (with 3.6 fb^{-1}) and CMS (with 2.6 fb^{-1}). We find there is no conflict between the signal reported at 13 TeV, and the constraints from both experiments at 8 TeV with 20.3 fb^{-1}. We make a simple argument for why adding only one new resonance to the standard model (SM) is not sufficient to explain the observation. We explore four viable options: (i): resonance production and decay through loops of messenger fermions or scalars; (ii): a resonant messenger which decays to the di-photon resonance + X; (iii): an edge configuration where A -> B gamma -> C gamma gamma, and (iv): Hidden Valley-like models where the resonance decays to a pair of very light (sub-GeV) states, each of which in turn decays to a pair of collimated photons that cannot be distinguished from a single photon. Since in each case multiple new states have been introduced, a wealth of signatures is expected to ensue at Run-2 of LHC.
1910.09581
Rosa Mar\'ia Sand\'a Seoane
Ezequiel Alvarez, Aurelio Juste, Rosa Mar\'ia Sand\'a Seoane
Four-top as probe of light top-philic New Physics
33 pages, 14 figures. JHEP accepted version
null
10.1007/JHEP12(2019)080
ICAS 043/19
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the four-top final state at the LHC as a probe for New Physics (NP) effects due to new particles that couple predominantly to the top quark and whose masses are below the top-quark-pair production threshold. We consider simple NP models containing a new particle with either spin 0, spin 1, or spin 2, and find benchmark points compatible with current experimental results. We find that interference effects between NP and QED amplitudes can be large, pointing out the necessity of NLO contributions to be explicitly computed and taken into account when NP is present. We examine kinematic differences between these models and the Standard Model (SM) at the parton level and the reconstructed level. In the latter case, we focus on events selected requiring two same-sign leptons and multiple jets. We investigate how the different Lorentz structure of the light NP affects the kinematic hardness, the polarization, the spin correlations, and the angular distributions of the parton-level and/or final-state particles. We find that spin-2 light NP would be identified by harder kinematics than the SM. We also show that the angular separation between the same-sign leptons is a sensitive observable for spin-0 NP. The spin-0 and spin-2 NP cases would also yield a signal in $t\bar t \gamma\gamma$ with the invariant mass of the photons indicating the mass of the new particle. The spin-1 NP would be identified through an excess in four-top signal and slight or not modification in other observables, as for instance the lack of signal in $t\bar t \gamma\gamma$ due to the Landau-Yang theorem. We comment on the opportunities that would open from the kinematic reconstruction of some of the top quarks in the four-top state. Our results provide new handles to probe for light top-philic NP as part of the ongoing experimental program of searches for four-top production at the LHC Run 2 and beyond.
[ { "created": "Mon, 21 Oct 2019 18:18:53 GMT", "version": "v1" }, { "created": "Thu, 28 Nov 2019 16:26:07 GMT", "version": "v2" } ]
2020-01-29
[ [ "Alvarez", "Ezequiel", "" ], [ "Juste", "Aurelio", "" ], [ "Seoane", "Rosa María Sandá", "" ] ]
We study the four-top final state at the LHC as a probe for New Physics (NP) effects due to new particles that couple predominantly to the top quark and whose masses are below the top-quark-pair production threshold. We consider simple NP models containing a new particle with either spin 0, spin 1, or spin 2, and find benchmark points compatible with current experimental results. We find that interference effects between NP and QED amplitudes can be large, pointing out the necessity of NLO contributions to be explicitly computed and taken into account when NP is present. We examine kinematic differences between these models and the Standard Model (SM) at the parton level and the reconstructed level. In the latter case, we focus on events selected requiring two same-sign leptons and multiple jets. We investigate how the different Lorentz structure of the light NP affects the kinematic hardness, the polarization, the spin correlations, and the angular distributions of the parton-level and/or final-state particles. We find that spin-2 light NP would be identified by harder kinematics than the SM. We also show that the angular separation between the same-sign leptons is a sensitive observable for spin-0 NP. The spin-0 and spin-2 NP cases would also yield a signal in $t\bar t \gamma\gamma$ with the invariant mass of the photons indicating the mass of the new particle. The spin-1 NP would be identified through an excess in four-top signal and slight or not modification in other observables, as for instance the lack of signal in $t\bar t \gamma\gamma$ due to the Landau-Yang theorem. We comment on the opportunities that would open from the kinematic reconstruction of some of the top quarks in the four-top state. Our results provide new handles to probe for light top-philic NP as part of the ongoing experimental program of searches for four-top production at the LHC Run 2 and beyond.
0810.2199
Zhenjun Xiao
Zhen-Jun Xiao
NLO contributions in the pQCD approach
3 pages, 5 ps figures, to appear in proceedings of ICHEP-2008, Philadelphia, USA, 2008. Typoes removed
null
null
NJNU-TH-08-16
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The NLO contributions to some two-body charmless hadronic B meson decays, such as those from the QCD vertex corrections, the quark loops and the chromo-magnetic penguins, have been calculated in the pQCD factorization approach.
[ { "created": "Mon, 13 Oct 2008 12:37:34 GMT", "version": "v1" }, { "created": "Fri, 12 Dec 2008 09:45:27 GMT", "version": "v2" } ]
2008-12-12
[ [ "Xiao", "Zhen-Jun", "" ] ]
The NLO contributions to some two-body charmless hadronic B meson decays, such as those from the QCD vertex corrections, the quark loops and the chromo-magnetic penguins, have been calculated in the pQCD factorization approach.
2007.09697
Xiao-Yun Wang
Xiao-Yun Wang, Qing-Yong Lin, Hao Xu, Ya-Ping Xie, Yin Huang and Xurong Chen
Discovery potential for the LHCb fully-charm tetraquark $X(6900)$ state via $\bar{p}p$ annihilation reaction
4 pages, 2 figures
Phys. Rev. D 102, 116014 (2020)
10.1103/PhysRevD.102.116014
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Inspired by the observation of the fully-charm tetraquark $X(6900)$ state at LHCb, the production of $X(6900)$ in $\bar{p}p\rightarrow J/\psi J/\psi $ reaction is studied within an effective Lagrangian approach and Breit-Wigner formula. The numerical results show that the cross section of $X(6900)$ at the c.m. energy of 6.9 GeV is much larger than that from the background contribution. Moreover, we estimate dozens of signal events can be detected by D0 experiment, which indicates that searching for the $X(6900)$ via antiproton-proton scattering may be a very important and promising way. Therefore, related experiments are suggested to be carried out.
[ { "created": "Sun, 19 Jul 2020 15:52:46 GMT", "version": "v1" }, { "created": "Wed, 22 Jul 2020 10:05:57 GMT", "version": "v2" } ]
2021-01-04
[ [ "Wang", "Xiao-Yun", "" ], [ "Lin", "Qing-Yong", "" ], [ "Xu", "Hao", "" ], [ "Xie", "Ya-Ping", "" ], [ "Huang", "Yin", "" ], [ "Chen", "Xurong", "" ] ]
Inspired by the observation of the fully-charm tetraquark $X(6900)$ state at LHCb, the production of $X(6900)$ in $\bar{p}p\rightarrow J/\psi J/\psi $ reaction is studied within an effective Lagrangian approach and Breit-Wigner formula. The numerical results show that the cross section of $X(6900)$ at the c.m. energy of 6.9 GeV is much larger than that from the background contribution. Moreover, we estimate dozens of signal events can be detected by D0 experiment, which indicates that searching for the $X(6900)$ via antiproton-proton scattering may be a very important and promising way. Therefore, related experiments are suggested to be carried out.
hep-ph/9804399
Vladimir V. Vereshagin
Alexander V.Vereshagin, Vladimir V.Vereshagin (St-Petersburg State University)
Effective theories with maximal analyticity
33 pages, 2 figures, 1 table, LATEX
Phys.Rev. D59 (1999) 016002
10.1103/PhysRevD.59.016002
SPBU-IP-98-9
hep-ph
null
In this paper (second in the series) we study the properties of tree-level binary amplitudes of the infinite-component effective field theory of strong interaction obeying the requirements of quark-hadron duality and maximal analyticity. In contrast to the previous paper, here we derive the results following from less restrictive --- Regge-like --- boundedness conditions. We develop the technique of Cauchy's forms in two variables and show the string-like structure of a theory. Next, we derive the full set of bootstrap constraints for the resonance parameters in (\pi,K) system. Numerical test shows: (1) those constraints are consistent with data on well established vector resonances; (2) two light broad resonances -- sigma- and kappa-mesons -- are needed to saturate sum rules following from Chiral symmetry and analyticity. As a by-product we obtain expressions for the parameters of Chiral expansions and give corresponding estimates.
[ { "created": "Sat, 25 Apr 1998 13:17:49 GMT", "version": "v1" } ]
2009-10-31
[ [ "Vereshagin", "Alexander V.", "", "St-Petersburg State\n University" ], [ "Vereshagin", "Vladimir V.", "", "St-Petersburg State\n University" ] ]
In this paper (second in the series) we study the properties of tree-level binary amplitudes of the infinite-component effective field theory of strong interaction obeying the requirements of quark-hadron duality and maximal analyticity. In contrast to the previous paper, here we derive the results following from less restrictive --- Regge-like --- boundedness conditions. We develop the technique of Cauchy's forms in two variables and show the string-like structure of a theory. Next, we derive the full set of bootstrap constraints for the resonance parameters in (\pi,K) system. Numerical test shows: (1) those constraints are consistent with data on well established vector resonances; (2) two light broad resonances -- sigma- and kappa-mesons -- are needed to saturate sum rules following from Chiral symmetry and analyticity. As a by-product we obtain expressions for the parameters of Chiral expansions and give corresponding estimates.
1309.1657
Florian Senzel
Florian Senzel, Oliver Fochler, Jan Uphoff, Zhe Xu, Carsten Greiner
Influence of multiple in-medium scattering processes on the momentum imbalance of reconstructed di-jets
14 pages, 10 figures, Major revision and recalculation of results
J.Phys. G42 (2015) no.11, 115104
10.1088/0954-3899/42/11/115104
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Experimental data measured in sqrt(s)=2.76 TeV Pb+Pb collisions at the LHC show a significant enhancement of events with an unbalanced pair of reconstructed jet momenta in comparison with p+p collisions. This enhancement of momentum imbalance is supposed to be caused by the different momentum loss of the initial back-to-back di-partons by scatterings within the created dense medium. For investigating the underlying partonic momentum loss we employ the on-shell transport model BAMPS (Boltzmann Approach for Multi-Parton Scattering) for full heavy-ion collisions, which numerically solves the 3+1D Boltzmann equation based on 2->2 as well as inelastic 2<->3 scattering processes, together with PYTHIA initial state conditions for the parton showers. Due to the employed test-particle approach jet reconstruction within BAMPS events is not trivial. We introduce a method that nevertheless allows the microscopic simulation of the full evolution of the shower particles, recoiled medium particles, and the underlying bulk medium in one common microscopic framework. With this method it is possible to investigate the role of the medium recoil for the momentum imbalance A_J while using well-established background subtraction algorithms. Due to the available particle information in configuration as well as momentum space within BAMPS, it is additionally possible to reproduce the entire evolution of the reconstructed jets within the medium. With this information we investigate the sensitivity of the jet momentum loss from the difference in the partonic in-medium path lengths.
[ { "created": "Fri, 6 Sep 2013 14:42:38 GMT", "version": "v1" }, { "created": "Fri, 24 Jul 2015 13:51:51 GMT", "version": "v2" } ]
2016-11-28
[ [ "Senzel", "Florian", "" ], [ "Fochler", "Oliver", "" ], [ "Uphoff", "Jan", "" ], [ "Xu", "Zhe", "" ], [ "Greiner", "Carsten", "" ] ]
Experimental data measured in sqrt(s)=2.76 TeV Pb+Pb collisions at the LHC show a significant enhancement of events with an unbalanced pair of reconstructed jet momenta in comparison with p+p collisions. This enhancement of momentum imbalance is supposed to be caused by the different momentum loss of the initial back-to-back di-partons by scatterings within the created dense medium. For investigating the underlying partonic momentum loss we employ the on-shell transport model BAMPS (Boltzmann Approach for Multi-Parton Scattering) for full heavy-ion collisions, which numerically solves the 3+1D Boltzmann equation based on 2->2 as well as inelastic 2<->3 scattering processes, together with PYTHIA initial state conditions for the parton showers. Due to the employed test-particle approach jet reconstruction within BAMPS events is not trivial. We introduce a method that nevertheless allows the microscopic simulation of the full evolution of the shower particles, recoiled medium particles, and the underlying bulk medium in one common microscopic framework. With this method it is possible to investigate the role of the medium recoil for the momentum imbalance A_J while using well-established background subtraction algorithms. Due to the available particle information in configuration as well as momentum space within BAMPS, it is additionally possible to reproduce the entire evolution of the reconstructed jets within the medium. With this information we investigate the sensitivity of the jet momentum loss from the difference in the partonic in-medium path lengths.
0711.1795
Jiri Chyla
Jiri Chyla
Sense and Nonsense on Parton Distribution functions of the Photon
Talk given at the International Symposium PHOTON 2007, Paris, July 2007, 4 pages and 1 figure, references corrected
Nucl.Phys.Proc.Suppl.184:23-26,2008
10.1016/j.nuclphysbps.2008.09.128
null
hep-ph
null
The organization of finite order QCD approximations to $F_2^{\gamma}(x,Q^2)$ based on the separation of pure QED contribution from those of genuine QCD nature is discussed.
[ { "created": "Mon, 12 Nov 2007 16:01:07 GMT", "version": "v1" }, { "created": "Tue, 11 Dec 2007 18:23:49 GMT", "version": "v2" } ]
2009-02-12
[ [ "Chyla", "Jiri", "" ] ]
The organization of finite order QCD approximations to $F_2^{\gamma}(x,Q^2)$ based on the separation of pure QED contribution from those of genuine QCD nature is discussed.
1009.5377
Stefano Profumo
Stefano Profumo, Lorenzo Ubaldi and Carroll Wainwright
Singlet Scalar Dark Matter: monochromatic gamma rays and metastable vacua
21 pages, 6 figures; references added, minor additions to text and figures, version accepted for publication in Phys. Rev. D
Phys.Rev.D82:123514,2010
10.1103/PhysRevD.82.123514
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the pair-annihilation cross section of real scalar singlet dark matter into two mono-energetic photons. We derive constraints on the theory parameter space from the Fermi limits on gamma-ray lines, and we compare with current limits from direct dark matter detection. We show that the new limits, albeit typically relevant only when the dark matter mass is close to half the Standard Model Higgs mass, rule out regions of the theory parameter space that are otherwise not constrained by other observations or experiments. In particular, the new excluded regions partly overlap with the parameter space where real scalar singlet dark matter might explain the anomalous signals observed by CDMS. We also calculate the lifetime of unstable vacuum configurations in the scalar potential, and show that the gamma-ray limits are quite relevant in regions where the electro-weak vacuum is meta-stable with a lifetime longer than the age of the universe.
[ { "created": "Mon, 27 Sep 2010 20:00:05 GMT", "version": "v1" }, { "created": "Wed, 17 Nov 2010 21:34:20 GMT", "version": "v2" } ]
2010-12-24
[ [ "Profumo", "Stefano", "" ], [ "Ubaldi", "Lorenzo", "" ], [ "Wainwright", "Carroll", "" ] ]
We calculate the pair-annihilation cross section of real scalar singlet dark matter into two mono-energetic photons. We derive constraints on the theory parameter space from the Fermi limits on gamma-ray lines, and we compare with current limits from direct dark matter detection. We show that the new limits, albeit typically relevant only when the dark matter mass is close to half the Standard Model Higgs mass, rule out regions of the theory parameter space that are otherwise not constrained by other observations or experiments. In particular, the new excluded regions partly overlap with the parameter space where real scalar singlet dark matter might explain the anomalous signals observed by CDMS. We also calculate the lifetime of unstable vacuum configurations in the scalar potential, and show that the gamma-ray limits are quite relevant in regions where the electro-weak vacuum is meta-stable with a lifetime longer than the age of the universe.
2012.13947
Gilbert Moultaka
Gilbert Moultaka and Michel C. Peyran\`ere
Vacuum Stability Conditions for Higgs Potentials with $SU(2)_L$ Triplets
95 pages, 15 figures, 1 table, added comments in the introduction, 2 footnotes, a new paragraph in section V, new references, to appear in Physical Review D
Phys. Rev. D 103, 115006 (2021)
10.1103/PhysRevD.103.115006
null
hep-ph math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Tree-level dynamical stability of scalar field potentials in renormalizable theories can in principle be expressed in terms of positivity conditions on quartic polynomial structures. However, these conditions cannot always be cast in a fully analytical resolved form, involving only the couplings and being valid for all field directions. In this paper we consider such forms in three physically motivated models involving $SU(2)$ triplet scalar fields: the Type-II seesaw model, the Georgi-Machacek model, and a generalized two-triplet model. A detailed analysis of the latter model allows to establish the full set of necessary and sufficient boundedness from below conditions. These can serve as a guide, together with unitarity and vacuum structure constraints, for consistent phenomenological (tree-level) studies. They also provide a seed for improved loop-level conditions, and encompass in particular the leading ones for the more specific Georgi-Machacek case. Incidentally, we present complete proofs of various properties and also derive general positivity conditions on quartic polynomials that are equivalent but much simpler than the ones used in the literature.
[ { "created": "Sun, 27 Dec 2020 14:17:46 GMT", "version": "v1" }, { "created": "Thu, 4 Mar 2021 07:25:09 GMT", "version": "v2" } ]
2021-06-16
[ [ "Moultaka", "Gilbert", "" ], [ "Peyranère", "Michel C.", "" ] ]
Tree-level dynamical stability of scalar field potentials in renormalizable theories can in principle be expressed in terms of positivity conditions on quartic polynomial structures. However, these conditions cannot always be cast in a fully analytical resolved form, involving only the couplings and being valid for all field directions. In this paper we consider such forms in three physically motivated models involving $SU(2)$ triplet scalar fields: the Type-II seesaw model, the Georgi-Machacek model, and a generalized two-triplet model. A detailed analysis of the latter model allows to establish the full set of necessary and sufficient boundedness from below conditions. These can serve as a guide, together with unitarity and vacuum structure constraints, for consistent phenomenological (tree-level) studies. They also provide a seed for improved loop-level conditions, and encompass in particular the leading ones for the more specific Georgi-Machacek case. Incidentally, we present complete proofs of various properties and also derive general positivity conditions on quartic polynomials that are equivalent but much simpler than the ones used in the literature.
2110.01356
Le Tho Hue
L. T. Hue, A. E. C\'arcamo Hern\'andez, H. N. Long, and T. T.Hong
Heavy singly charged Higgs bosons and inverse seesaw neutrinos as origins of large $(g-2)_{e,\mu}$ in two higgs doublet models
30 pages, 9 figures. Numerical results were corrected. New references were added. Version accepted for publication in NPB
null
10.1016/j.nuclphysb.2022.115962
null
hep-ph
http://creativecommons.org/publicdomain/zero/1.0/
We show that simple extensions of two Higgs doublet models consisting of new heavy neutrinos and a singly charged Higgs boson singlet can successfully explain the experimental data on muon and electron anomalous magnetic moments thanks to large chirally-enhanced one-loop level contributions. These contributions arise from the large couplings of inverse seesaw neutrinos with singly charged Higgs bosons and right-handed charged leptons. The regions of parameter space satisfying the experimental data on $(g-2)_{e,\mu}$ anomalies allow heavy singly charged Higgs boson masses above the TeV scale, provided that heavy neutrino masses are above few hundred GeV, the non-unitary part of the active neutrino mixing matrix must be large enough, two singly charged Higgs bosons are non degenerate, and the mixing between singly charged Higgs bosons must be non-zero.
[ { "created": "Mon, 4 Oct 2021 12:09:40 GMT", "version": "v1" }, { "created": "Wed, 21 Sep 2022 03:16:50 GMT", "version": "v2" } ]
2022-09-22
[ [ "Hue", "L. T.", "" ], [ "Hernández", "A. E. Cárcamo", "" ], [ "Long", "H. N.", "" ], [ "Hong", "T. T.", "" ] ]
We show that simple extensions of two Higgs doublet models consisting of new heavy neutrinos and a singly charged Higgs boson singlet can successfully explain the experimental data on muon and electron anomalous magnetic moments thanks to large chirally-enhanced one-loop level contributions. These contributions arise from the large couplings of inverse seesaw neutrinos with singly charged Higgs bosons and right-handed charged leptons. The regions of parameter space satisfying the experimental data on $(g-2)_{e,\mu}$ anomalies allow heavy singly charged Higgs boson masses above the TeV scale, provided that heavy neutrino masses are above few hundred GeV, the non-unitary part of the active neutrino mixing matrix must be large enough, two singly charged Higgs bosons are non degenerate, and the mixing between singly charged Higgs bosons must be non-zero.
2306.17520
Michele Tammaro
Jernej F. Kamenik, Arman Korajac, Manuel Szewc, Michele Tammaro, Jure Zupan
Flavor violating Higgs and $Z$ decays at FCC-ee
22 pages, 15 figures
null
10.1103/PhysRevD.109.L011301
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Recent advances in $b$, $c$, and $s$ quark tagging coupled with novel statistical analysis techniques will allow future high energy and high statistics electron-positron colliders, such as the FCC-ee, to place phenomenologically relevant bounds on flavor violating Higgs and $Z$ decays to quarks. We assess the FCC-ee reach for $Z/h\to bs, cu$ decays as a function of jet tagging performance. We also update the SM predictions for the corresponding branching ratios, as well as the indirect constraints on the flavor violating Higgs and $Z$ couplings to quarks. Using type III two Higgs doublet model as an example of beyond the standard model physics, we show that the searches for $h\to bs, cu$ decays at FCC-ee can probe new parameter space not excluded by indirect searches. We also reinterpret the FCC-ee reach for $Z\to bs , cu$ in terms of the constraints on models with vectorlike quarks.
[ { "created": "Fri, 30 Jun 2023 10:16:59 GMT", "version": "v1" }, { "created": "Thu, 11 Jul 2024 07:44:11 GMT", "version": "v2" } ]
2024-07-12
[ [ "Kamenik", "Jernej F.", "" ], [ "Korajac", "Arman", "" ], [ "Szewc", "Manuel", "" ], [ "Tammaro", "Michele", "" ], [ "Zupan", "Jure", "" ] ]
Recent advances in $b$, $c$, and $s$ quark tagging coupled with novel statistical analysis techniques will allow future high energy and high statistics electron-positron colliders, such as the FCC-ee, to place phenomenologically relevant bounds on flavor violating Higgs and $Z$ decays to quarks. We assess the FCC-ee reach for $Z/h\to bs, cu$ decays as a function of jet tagging performance. We also update the SM predictions for the corresponding branching ratios, as well as the indirect constraints on the flavor violating Higgs and $Z$ couplings to quarks. Using type III two Higgs doublet model as an example of beyond the standard model physics, we show that the searches for $h\to bs, cu$ decays at FCC-ee can probe new parameter space not excluded by indirect searches. We also reinterpret the FCC-ee reach for $Z\to bs , cu$ in terms of the constraints on models with vectorlike quarks.
hep-ph/0312275
H. Caldas
Heron Caldas
Cold asymmetrical fermion superfluids
21 pages, 5 figures, RevTex, typos corrected, introduction improved, accepted for publication in PRA
Phys.Rev.A69:063602,2004
10.1103/PhysRevA.69.063602
null
hep-ph cond-mat.supr-con
null
In this work we investigate the general properties and the ground state of an asymmetrical dilute gas of cold fermionic atoms, formed by two particle species having different densities. We have show in a recent paper, that a mixed phase composed of normal and superfluid components is the energetically favored ground state of such a cold fermionic system. Here we extend the analysis and verify that in fact, the mixed phase is the preferred ground state of an asymmetrical superfluid in various situatiations. We predict that the mixed phase can serve as a way of detecting superfluidity and estimating the magnitude of the gap parameter in asymmetrical fermionic systems.
[ { "created": "Fri, 19 Dec 2003 05:47:30 GMT", "version": "v1" }, { "created": "Sat, 27 Mar 2004 02:26:10 GMT", "version": "v2" } ]
2014-11-17
[ [ "Caldas", "Heron", "" ] ]
In this work we investigate the general properties and the ground state of an asymmetrical dilute gas of cold fermionic atoms, formed by two particle species having different densities. We have show in a recent paper, that a mixed phase composed of normal and superfluid components is the energetically favored ground state of such a cold fermionic system. Here we extend the analysis and verify that in fact, the mixed phase is the preferred ground state of an asymmetrical superfluid in various situatiations. We predict that the mixed phase can serve as a way of detecting superfluidity and estimating the magnitude of the gap parameter in asymmetrical fermionic systems.
hep-ph/9803320
Tracas Nicholas
G.K. Leontaris and N.D. Tracas
Lepton Flavour Violation in Unified Models with U(1)-Family Symmetries
14 pages, 1 figure included in the ps file, uses epsfig.sty
Phys.Lett. B431 (1998) 90-97
10.1016/S0370-2693(98)00474-2
IOA-TH/98-03, NTUA-70/98
hep-ph
null
Lepton flavour non-conserving processes are examined in the context of unified models with U(1)-family symmetries which reproduce successfully the low-energy hierarchy of the fermion mass spectrum and the Kobayashi - Maskawa mixing. These models usually imply mixing effects in the supersymmetric scalar sector. We construct the fermion and scalar mass matrices in two viable models, and calculate the mixing effects on the $\mu \to e\gamma$, $\mu \to 3 e$ and $\tau \to \mu\gamma$ rare decays. The relevant constraints on the sparticle mass spectrum as well as the role of various MSSM parameters are discussed.
[ { "created": "Thu, 12 Mar 1998 15:02:14 GMT", "version": "v1" } ]
2009-10-31
[ [ "Leontaris", "G. K.", "" ], [ "Tracas", "N. D.", "" ] ]
Lepton flavour non-conserving processes are examined in the context of unified models with U(1)-family symmetries which reproduce successfully the low-energy hierarchy of the fermion mass spectrum and the Kobayashi - Maskawa mixing. These models usually imply mixing effects in the supersymmetric scalar sector. We construct the fermion and scalar mass matrices in two viable models, and calculate the mixing effects on the $\mu \to e\gamma$, $\mu \to 3 e$ and $\tau \to \mu\gamma$ rare decays. The relevant constraints on the sparticle mass spectrum as well as the role of various MSSM parameters are discussed.
hep-ph/0002052
Arnd Leike
Stephen Godfrey, Pat Kalyniak, Basim Kamal, Arnd Leike
Constraints on Extra Gauge Bosons in e gamma Collisions
6 pages Latex, 5 figures included by epsf, uses e-e-ijmpa.sty and citepunct.sty (included)
Int.J.Mod.Phys. A15 (2000) 2623
10.1142/S0217751X00002706
LMU 01/00
hep-ph
null
We investigate the sensitivity of e- gamma ---> nu_e nu_mu(bar) mu- to extra charged gauge bosons. The sensitivity is much below that of e-e+ ---> nu nu(bar) gamma. We conclude that e- gamma ---> d u(bar) nu_e and e- gamma ---> f f(bar) e- are also inferior to e+e- collisions in setting bounds on extra charged and neutral gauge bosons and on four fermion contact interactions.
[ { "created": "Fri, 4 Feb 2000 15:47:08 GMT", "version": "v1" } ]
2015-06-25
[ [ "Godfrey", "Stephen", "" ], [ "Kalyniak", "Pat", "" ], [ "Kamal", "Basim", "" ], [ "Leike", "Arnd", "" ] ]
We investigate the sensitivity of e- gamma ---> nu_e nu_mu(bar) mu- to extra charged gauge bosons. The sensitivity is much below that of e-e+ ---> nu nu(bar) gamma. We conclude that e- gamma ---> d u(bar) nu_e and e- gamma ---> f f(bar) e- are also inferior to e+e- collisions in setting bounds on extra charged and neutral gauge bosons and on four fermion contact interactions.
0709.0100
Oleg Selyugin
O.V. Selyugin, J.-R. Cudell
Saturation effects in elastic scattering at the LHC
6 pages, 4 figures, talk presented at EDS07
null
null
null
hep-ph
null
The problems linked to the extraction of the basic parameters of the hadron elastic scattering amplitude at the LHC are explored. The impact of the Black Disk Limit (BDL)$-$ which constitutes a new regime of the scattering processes - on the determination of these values is examined.
[ { "created": "Sun, 2 Sep 2007 10:22:14 GMT", "version": "v1" } ]
2007-09-04
[ [ "Selyugin", "O. V.", "" ], [ "Cudell", "J. -R.", "" ] ]
The problems linked to the extraction of the basic parameters of the hadron elastic scattering amplitude at the LHC are explored. The impact of the Black Disk Limit (BDL)$-$ which constitutes a new regime of the scattering processes - on the determination of these values is examined.
2008.09652
Gauthier Durieux
Gauthier Durieux, Teppei Kitahara, Camila S. Machado, Yael Shadmi, Yaniv Weiss
Constructing massive on-shell contact terms
27 pages, 1 figure and 5 tables; v2: vvvs counting corrected
JHEP 12 (2020) 175
10.1007/JHEP12(2020)175
MITP/20-046
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
The purely on-shell approach to effective field theories requires the construction of independent contact terms. Employing the little-group-covariant massive-spinor formalism, we present the first systematic derivation of independent four-point contact terms involving massive scalars, spin-1/2 fermions, and vectors. Independent three-point amplitudes are also listed for massive particles up to spin-3. We make extensive use of the simple relations between massless and massive amplitudes in this formalism. Our general results are specialized to the (broken-phase) particle content of the electroweak sector of the standard model. The (anti)symmetrization among identical particles is then accounted for. This work opens the way for the on-shell computation of massive four-point amplitudes.
[ { "created": "Fri, 21 Aug 2020 18:59:10 GMT", "version": "v1" }, { "created": "Thu, 20 Oct 2022 08:40:01 GMT", "version": "v2" } ]
2022-10-21
[ [ "Durieux", "Gauthier", "" ], [ "Kitahara", "Teppei", "" ], [ "Machado", "Camila S.", "" ], [ "Shadmi", "Yael", "" ], [ "Weiss", "Yaniv", "" ] ]
The purely on-shell approach to effective field theories requires the construction of independent contact terms. Employing the little-group-covariant massive-spinor formalism, we present the first systematic derivation of independent four-point contact terms involving massive scalars, spin-1/2 fermions, and vectors. Independent three-point amplitudes are also listed for massive particles up to spin-3. We make extensive use of the simple relations between massless and massive amplitudes in this formalism. Our general results are specialized to the (broken-phase) particle content of the electroweak sector of the standard model. The (anti)symmetrization among identical particles is then accounted for. This work opens the way for the on-shell computation of massive four-point amplitudes.
1011.2964
Jonathan Roberts
G. R. Farrar, R. Mackeprang, D. Milstead, J. P. Roberts
Limit on the mass of a long-lived or stable gluino
15 pages, 5 figures, accepted for publication in JHEP
JHEP 1102:018,2011
10.1007/JHEP02(2011)018
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We reinterpret the generic CDF charged massive particle limit to obtain a limit on the mass of a stable or long-lived gluino. Various sources of uncertainty are examined. The $R$-hadron spectrum and scattering cross sections are modeled based on known low-energy hadron physics and the resultant uncertainties are quantified and found to be small compared to uncertainties from the scale dependence of the NLO pQCD production cross sections. The largest uncertainty in the limit comes from the unknown squark mass: when the squark -- gluino mass splitting is small, we obtain a gluino mass limit of 407 GeV, while in the limit of heavy squarks the gluino mass limit is 397 GeV. For arbitrary (degenerate) squark masses, we obtain a lower limit of 322 GeV on the gluino mass. These limits apply for any gluino lifetime longer than $\sim 30$ ns, and are the most stringent limits for such a long-lived or stable gluino.
[ { "created": "Fri, 12 Nov 2010 15:56:23 GMT", "version": "v1" }, { "created": "Sun, 23 Jan 2011 18:58:07 GMT", "version": "v2" } ]
2015-03-17
[ [ "Farrar", "G. R.", "" ], [ "Mackeprang", "R.", "" ], [ "Milstead", "D.", "" ], [ "Roberts", "J. P.", "" ] ]
We reinterpret the generic CDF charged massive particle limit to obtain a limit on the mass of a stable or long-lived gluino. Various sources of uncertainty are examined. The $R$-hadron spectrum and scattering cross sections are modeled based on known low-energy hadron physics and the resultant uncertainties are quantified and found to be small compared to uncertainties from the scale dependence of the NLO pQCD production cross sections. The largest uncertainty in the limit comes from the unknown squark mass: when the squark -- gluino mass splitting is small, we obtain a gluino mass limit of 407 GeV, while in the limit of heavy squarks the gluino mass limit is 397 GeV. For arbitrary (degenerate) squark masses, we obtain a lower limit of 322 GeV on the gluino mass. These limits apply for any gluino lifetime longer than $\sim 30$ ns, and are the most stringent limits for such a long-lived or stable gluino.
1208.2458
Vivek Tiwari Kumar
Vivek Kumar Tiwari (Department of Physics, University of Allahabad, Allahabad, India)
Exploring criticality in the QCD-like two quark flavour models
19 pages with 20 Figures
null
10.1103/PhysRevD.86.094032
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The critical end-point (CEP) and critical behaviour in its vicinity, has been explored in the two flavour effective chiral models with and without the presence of effective Polyakov loop potential.The tricritical point (TCP) in the massless chiral limit has been located on the phase diagram in the \mu andT plane for the Polyakov loop extended Quark Meson Model (PQM) and pure Quark Meson (QM) model which become effective Quantum-chromodynamics (QCD) like models due to the proper accounting of fermionic vacuum loop contribution in the effective potential.The proximity of the TCP to the QCD critical end-point (CEP) has been quantified in the phase diagram. The critical region around CEP has been obtained in the presence as well as the absence of fermionic vacuum loop contribution in the effective potentials of PQM and QM models. The contours of appropriately normalized constant quark number susceptibility and scalar susceptibility have been plotted around CEP in different model scenarios. These contours determine the shape of critical region and facilitate comparisons in different models such that the influence of fermionic vacuum term and Polyakov loop potential on the critical behavior around CEP can be ascertained in qualitative as well as quantitative terms. Critical exponents resulting from the divergence of quark number susceptibility at the CEP,have been calulated and compared with in different model scenarios. The possible influence of TCP on the critical behavior around CEP, has also been discussed. The temperature variation of \sigma and \pi meson masses at \mu = 0, \mu = \mu_ CEP and \mu > \mu_CEP has been shown and compared with in different model scenarios and the emerging mass degeneration trend in the \sigma and \pi meson mass variations has been inferred as the chiral symmetry restoration takes place at higher temperatures.
[ { "created": "Sun, 12 Aug 2012 19:57:15 GMT", "version": "v1" } ]
2013-05-30
[ [ "Tiwari", "Vivek Kumar", "", "Department of Physics, University of Allahabad,\n Allahabad, India" ] ]
The critical end-point (CEP) and critical behaviour in its vicinity, has been explored in the two flavour effective chiral models with and without the presence of effective Polyakov loop potential.The tricritical point (TCP) in the massless chiral limit has been located on the phase diagram in the \mu andT plane for the Polyakov loop extended Quark Meson Model (PQM) and pure Quark Meson (QM) model which become effective Quantum-chromodynamics (QCD) like models due to the proper accounting of fermionic vacuum loop contribution in the effective potential.The proximity of the TCP to the QCD critical end-point (CEP) has been quantified in the phase diagram. The critical region around CEP has been obtained in the presence as well as the absence of fermionic vacuum loop contribution in the effective potentials of PQM and QM models. The contours of appropriately normalized constant quark number susceptibility and scalar susceptibility have been plotted around CEP in different model scenarios. These contours determine the shape of critical region and facilitate comparisons in different models such that the influence of fermionic vacuum term and Polyakov loop potential on the critical behavior around CEP can be ascertained in qualitative as well as quantitative terms. Critical exponents resulting from the divergence of quark number susceptibility at the CEP,have been calulated and compared with in different model scenarios. The possible influence of TCP on the critical behavior around CEP, has also been discussed. The temperature variation of \sigma and \pi meson masses at \mu = 0, \mu = \mu_ CEP and \mu > \mu_CEP has been shown and compared with in different model scenarios and the emerging mass degeneration trend in the \sigma and \pi meson mass variations has been inferred as the chiral symmetry restoration takes place at higher temperatures.
hep-ph/0607149
Joseph D. Lykken
Joseph D. Lykken
Moriond Electroweak 2006: Theory Summary
12 pages, 5 figures
null
null
FERMILAB-CONF-06-239-T
hep-ph
null
A concise look at the big picture of particle physics, including the status of the Standard Model, neutrinos, supersymmetry, extra dimensions and cosmology. Based upon the theoretical summary presented at the XLIst Rencontres de Moriond on Electroweak Interactions and Unified Theories, La Thuile, 11-18 March 2006.
[ { "created": "Thu, 13 Jul 2006 13:11:51 GMT", "version": "v1" } ]
2007-05-23
[ [ "Lykken", "Joseph D.", "" ] ]
A concise look at the big picture of particle physics, including the status of the Standard Model, neutrinos, supersymmetry, extra dimensions and cosmology. Based upon the theoretical summary presented at the XLIst Rencontres de Moriond on Electroweak Interactions and Unified Theories, La Thuile, 11-18 March 2006.
0706.0017
Davison E. Soper
Zoltan Nagy and Davison E. Soper
Parton showers with quantum interference
83 pages with 10 figures; revised version is close to published version
JHEP 0709:114,2007
10.1088/1126-6708/2007/09/114
CERN-PH-TH/2007-082
hep-ph
null
We specify recursive equations that could be used to generate a lowest order parton shower for hard scattering in hadron-hadron collisions. The formalism is based on the factorization soft and collinear interactions from relatively harder interactions in QCD amplitudes. It incorporates quantum interference between different amplitudes in those cases in which the interference diagrams have leading soft or collinear singularities. It incorporates the color and spin information carried by partons emerging from a hard interaction. One motivation for this work is to have a method that can naturally cooperate with next-to-leading order calculations.
[ { "created": "Fri, 1 Jun 2007 18:08:38 GMT", "version": "v1" }, { "created": "Tue, 2 Oct 2007 23:48:59 GMT", "version": "v2" } ]
2009-04-22
[ [ "Nagy", "Zoltan", "" ], [ "Soper", "Davison E.", "" ] ]
We specify recursive equations that could be used to generate a lowest order parton shower for hard scattering in hadron-hadron collisions. The formalism is based on the factorization soft and collinear interactions from relatively harder interactions in QCD amplitudes. It incorporates quantum interference between different amplitudes in those cases in which the interference diagrams have leading soft or collinear singularities. It incorporates the color and spin information carried by partons emerging from a hard interaction. One motivation for this work is to have a method that can naturally cooperate with next-to-leading order calculations.
1812.07181
Yucheng Qiu
Yu-Cheng Qiu and S.-H. Henry Tye
Role of Bloch Waves in baryon-number violating processes
13 pages, 11 figures
Phys. Rev. D 100, 033006 (2019)
10.1103/PhysRevD.100.033006
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the Bloch-wave approach to estimate the baryon-number-violating scattering cross section in the standard electroweak theory in the laboratory, we clarify the relation between the single sphaleron barrier and multiple (near periodic) sphaleron barrier cases. We explain how a realistic consideration modifies/corrects the idealized Bloch wave and the resonant tunneling approximation. The basic approach is in part analogous to the well-known triple-$\alpha$ process to form carbon in nucleosynthesis.
[ { "created": "Tue, 18 Dec 2018 05:42:18 GMT", "version": "v1" }, { "created": "Tue, 5 Mar 2019 09:54:48 GMT", "version": "v2" }, { "created": "Thu, 29 Aug 2019 11:22:53 GMT", "version": "v3" } ]
2019-08-30
[ [ "Qiu", "Yu-Cheng", "" ], [ "Tye", "S. -H. Henry", "" ] ]
In the Bloch-wave approach to estimate the baryon-number-violating scattering cross section in the standard electroweak theory in the laboratory, we clarify the relation between the single sphaleron barrier and multiple (near periodic) sphaleron barrier cases. We explain how a realistic consideration modifies/corrects the idealized Bloch wave and the resonant tunneling approximation. The basic approach is in part analogous to the well-known triple-$\alpha$ process to form carbon in nucleosynthesis.
1404.6204
Piotr Kotko
A. van Hameren, P. Kotko, K. Kutak, S. Sapeta
Small-$x$ dynamics in forward-central dijet decorrelations at the LHC
10 pages, 4 figures; legends of the plots corrected, references added, minor refinements
null
10.1016/j.physletb.2014.09.005
IFJPAN-IV-2014-6, CERN-PH-TH-2014-070
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We provide a description, within the High Energy Factorization formalism, of central-forward dijet decorrelation data measured by the CMS experiment and the predictions for nuclear modification ratio~$R_{pA}$ in p+Pb collisions. In our study, we use the unintegrated gluon density derived from the BFKL and BK equations supplemented with subleading corrections and a hard scale dependence. The latter is introduced at the final step of the calculation by reweighting the Monte Carlo generated events using suitable Sudakov form factors, without changing the total cross section. We achieve a good description of data in the whole region of the azimuthal angle.
[ { "created": "Thu, 24 Apr 2014 17:58:31 GMT", "version": "v1" }, { "created": "Wed, 7 May 2014 16:38:36 GMT", "version": "v2" } ]
2015-06-19
[ [ "van Hameren", "A.", "" ], [ "Kotko", "P.", "" ], [ "Kutak", "K.", "" ], [ "Sapeta", "S.", "" ] ]
We provide a description, within the High Energy Factorization formalism, of central-forward dijet decorrelation data measured by the CMS experiment and the predictions for nuclear modification ratio~$R_{pA}$ in p+Pb collisions. In our study, we use the unintegrated gluon density derived from the BFKL and BK equations supplemented with subleading corrections and a hard scale dependence. The latter is introduced at the final step of the calculation by reweighting the Monte Carlo generated events using suitable Sudakov form factors, without changing the total cross section. We achieve a good description of data in the whole region of the azimuthal angle.