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2403.05011
Zhen-Hua Zhang
Yu-Jie Zhao, Zhen-Hua Zhang, Xin-Heng Guo
Decay-angular-distribution correlated $CP$ violation in heavy hadron cascade decays
16 pages
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
$C\!P$ violation in baryon decay processes is still undiscovered to date. We present a general analysis of the decay-angular-distributions and the corresponding $C\!P$ asymmetries in cascade decays of the type $\mathbb{H}\to R(\to ab) c$, where $\mathbb{H}$ is a heavy hadron that decays through weak interactions $\mathbb{H}\to R c$, and the resonance $R$ decays strongly via $R\to ab$. Based on the analysis, we propose to search for $C\!P$ violation in the decay-angular-distributions in the cascade decay processes ${\mathbb{B}}\to \mathcal{B} M$, with $\mathcal{B}$ or $M$ subsequently decaying through strong interactions, where ${\mathbb{B}}$ is the mother baryon, $\mathcal{B}$ or $M$ are the daughter baryon and meson, respectively, and $M$ has to be spin-nonzero. We also present some typical decay channels in which the search for such kinds of $C\!P$ asymmetries can be performed.
[ { "created": "Fri, 8 Mar 2024 03:18:05 GMT", "version": "v1" } ]
2024-03-11
[ [ "Zhao", "Yu-Jie", "" ], [ "Zhang", "Zhen-Hua", "" ], [ "Guo", "Xin-Heng", "" ] ]
$C\!P$ violation in baryon decay processes is still undiscovered to date. We present a general analysis of the decay-angular-distributions and the corresponding $C\!P$ asymmetries in cascade decays of the type $\mathbb{H}\to R(\to ab) c$, where $\mathbb{H}$ is a heavy hadron that decays through weak interactions $\mathbb{H}\to R c$, and the resonance $R$ decays strongly via $R\to ab$. Based on the analysis, we propose to search for $C\!P$ violation in the decay-angular-distributions in the cascade decay processes ${\mathbb{B}}\to \mathcal{B} M$, with $\mathcal{B}$ or $M$ subsequently decaying through strong interactions, where ${\mathbb{B}}$ is the mother baryon, $\mathcal{B}$ or $M$ are the daughter baryon and meson, respectively, and $M$ has to be spin-nonzero. We also present some typical decay channels in which the search for such kinds of $C\!P$ asymmetries can be performed.
hep-ph/0507072
Albrecht Kyrieleis
A. Kyrieleis
Gaps between Jets: Matching two Approaches
Talk given at 13th International Workshop on Deep Inelastic Scattering (DIS 2005), Madison/Wisconsin, USA, April 27 - May 1, 2005
null
10.1063/1.2122153
null
hep-ph
null
We calculate the parton level cross section for the production of two jets that are far apart in rapidity, subject to a limitation on the total transverse momentum Q_0 in the interjet region. We specifically address the question of how to combine the approach which sums all leading logarithms in Q/Q_0 (where Q is the jet transverse momentum) with the BFKL approach, in which leading logarithms of the scattering energy are summed. Using an "all orders" matching, we obtain results for the cross section which correctly reproduce the two approaches in the appropriate limits.
[ { "created": "Wed, 6 Jul 2005 14:56:53 GMT", "version": "v1" } ]
2015-06-25
[ [ "Kyrieleis", "A.", "" ] ]
We calculate the parton level cross section for the production of two jets that are far apart in rapidity, subject to a limitation on the total transverse momentum Q_0 in the interjet region. We specifically address the question of how to combine the approach which sums all leading logarithms in Q/Q_0 (where Q is the jet transverse momentum) with the BFKL approach, in which leading logarithms of the scattering energy are summed. Using an "all orders" matching, we obtain results for the cross section which correctly reproduce the two approaches in the appropriate limits.
2309.02905
Miguel Angel Martin Contreras Dr.
Miguel Angel Martin Contreras and Alfredo Vega
Holographic stability for non-$q\bar{q}$ candidates
10 pages, 1 figure, 3 tables
Phys. Rev. D 108, 126024 (2023)
10.1103/PhysRevD.108.126024
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
In the context of bottom-up AdS/QCD models, we discuss how the configurational entropy can describe heavy non-$q\,\bar{q}$ states. Using the non-quadratic softwall model, introduced to describe non-linear Regge trajectories, we parametrize different multiquark and exotic meson structures to describe $Z_c$, $\psi$, and $Z_b$ states as non-$q\,\bar{q}$ hadrons in terms of stability. We found that $Z_c$ is better described as a hybrid meson with one gluon tube, $\psi$ as hadrocharmonium, and $Z_b$ as hadronic molecule.
[ { "created": "Wed, 6 Sep 2023 10:55:59 GMT", "version": "v1" }, { "created": "Tue, 2 Jan 2024 03:11:50 GMT", "version": "v2" } ]
2024-01-03
[ [ "Contreras", "Miguel Angel Martin", "" ], [ "Vega", "Alfredo", "" ] ]
In the context of bottom-up AdS/QCD models, we discuss how the configurational entropy can describe heavy non-$q\,\bar{q}$ states. Using the non-quadratic softwall model, introduced to describe non-linear Regge trajectories, we parametrize different multiquark and exotic meson structures to describe $Z_c$, $\psi$, and $Z_b$ states as non-$q\,\bar{q}$ hadrons in terms of stability. We found that $Z_c$ is better described as a hybrid meson with one gluon tube, $\psi$ as hadrocharmonium, and $Z_b$ as hadronic molecule.
1511.00664
Joydeep Roy
Joydeep Roy, Zachary Epstein, Gil Paz
Model Independent Analysis of the Proton Magnetic Radius
7 pages, 1 figure, Presentation at the DPF 2015 Meeting of the American Physical Society Division of Particles and Fields, Ann Arbor, Michigan, August 4-8, 2015
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The proton is a fundamental constituent of matter. It is an extended object with finite size that can be inferred with some degree of accuracy from several measurements. Using constraints from the analytic behavior of the form factors we present here a model-independent study that extracts the proton magnetic radius from scattering data. From electron-proton scattering data we find $r_M^p = 0.91_{-0.06}^{+0.03} \pm 0.02$ fm. When we include electron-neutron scattering data and $\pi\pi$ data, we find $r_M^p = 0.87_{-0.05}^{+0.04}\pm 0.01$ fm and $r_M^p =0.87_{-0.02}^{+0.02}$ fm respectively. The neutron magnetic radius is extracted as $r_M^n = 0.89_{-0.03}^{+0.03}$ fm combining all three data sets.
[ { "created": "Mon, 2 Nov 2015 20:27:40 GMT", "version": "v1" } ]
2015-11-03
[ [ "Roy", "Joydeep", "" ], [ "Epstein", "Zachary", "" ], [ "Paz", "Gil", "" ] ]
The proton is a fundamental constituent of matter. It is an extended object with finite size that can be inferred with some degree of accuracy from several measurements. Using constraints from the analytic behavior of the form factors we present here a model-independent study that extracts the proton magnetic radius from scattering data. From electron-proton scattering data we find $r_M^p = 0.91_{-0.06}^{+0.03} \pm 0.02$ fm. When we include electron-neutron scattering data and $\pi\pi$ data, we find $r_M^p = 0.87_{-0.05}^{+0.04}\pm 0.01$ fm and $r_M^p =0.87_{-0.02}^{+0.02}$ fm respectively. The neutron magnetic radius is extracted as $r_M^n = 0.89_{-0.03}^{+0.03}$ fm combining all three data sets.
2408.05167
Van Que Tran
Michael J. Ramsey-Musolf, Van Que Tran and Tzu-Chiang Yuan
Gravitational Waves and Dark Matter in the Gauged Two-Higgs Doublet Model
71 pages, 9 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We investigate the possibility of a strong first-order electroweak phase transition during the early universe within the framework of the gauged two-Higgs doublet model (G2HDM) and explore its detectability through stochastic gravitational wave signals. The G2HDM introduces a dark replica of the Standard Model electroweak gauge group, inducing an accidental $Z_2$ symmetry which not only leads to a simple scalar potential at tree-level but also offers a compelling vectorial dark matter candidate. Using the high temperature expansion in the effective potential that manifests gauge invariance, we find a possible two-step phase transition pattern in the model with a strong first-order transition occurring in the second step at the electroweak scale temperature. Collider data from the LHC plays a crucial role in constraining the parameter space conducive to this two-step transition. Furthermore, satisfying the nucleation condition necessitates the masses of scalar bosons in the hidden sector to align with the electroweak scale, potentially probed by future collider detectors. The stochastic gravitational wave energy spectrum associated with the phase transition is computed. The results indicate that forthcoming detectors such as BBO, LISA, DECIGO, TianQin and Taiji could potentially detect the gravitational wave signals generated by the first-order phase transition. Additionally, we find that the parameter space probed by gravitational waves can also be searched for in future dark matter direct detection experiments, in particular those designed for dark matter masses in the sub-GeV range using the superfluid Helium target detectors.
[ { "created": "Fri, 9 Aug 2024 16:44:08 GMT", "version": "v1" } ]
2024-08-12
[ [ "Ramsey-Musolf", "Michael J.", "" ], [ "Tran", "Van Que", "" ], [ "Yuan", "Tzu-Chiang", "" ] ]
We investigate the possibility of a strong first-order electroweak phase transition during the early universe within the framework of the gauged two-Higgs doublet model (G2HDM) and explore its detectability through stochastic gravitational wave signals. The G2HDM introduces a dark replica of the Standard Model electroweak gauge group, inducing an accidental $Z_2$ symmetry which not only leads to a simple scalar potential at tree-level but also offers a compelling vectorial dark matter candidate. Using the high temperature expansion in the effective potential that manifests gauge invariance, we find a possible two-step phase transition pattern in the model with a strong first-order transition occurring in the second step at the electroweak scale temperature. Collider data from the LHC plays a crucial role in constraining the parameter space conducive to this two-step transition. Furthermore, satisfying the nucleation condition necessitates the masses of scalar bosons in the hidden sector to align with the electroweak scale, potentially probed by future collider detectors. The stochastic gravitational wave energy spectrum associated with the phase transition is computed. The results indicate that forthcoming detectors such as BBO, LISA, DECIGO, TianQin and Taiji could potentially detect the gravitational wave signals generated by the first-order phase transition. Additionally, we find that the parameter space probed by gravitational waves can also be searched for in future dark matter direct detection experiments, in particular those designed for dark matter masses in the sub-GeV range using the superfluid Helium target detectors.
2109.02737
Alexander Quiroga
Edwin A. Delgado, Hiroshi Nunokawa and Alexander A. Quiroga
Probing neutrino decay scenarios by using the Earth matter effects on supernova neutrinos
31 pages, 13 figures, 1 table
null
10.1088/1475-7516/2022/01/003
null
hep-ph astro-ph.HE
http://creativecommons.org/licenses/by-nc-nd/4.0/
The observation of Earth matter effects in the spectrum of neutrinos coming from a next galactic core-collapse supernova (CCSN) could, in principle, reveal if neutrino mass ordering is normal or inverted. One of the possible ways to identify the mass ordering is through the observation of the modulations that appear in the spectrum when neutrinos travel through the Earth before they arrive at the detector. These features in the neutrino spectrum depend on two factors, the average neutrino energies, and the difference between the primary neutrino fluxes of electron and other flavors produced inside the supernova. However, recent studies indicate that the Earth matter effect for CCSN neutrinos is expected to be rather small and difficult to be observed by currently operating or planned neutrino detectors mainly because of the similarity of average energies and fluxes between electron and other flavors of neutrinos, unless the distance to CCSN is significantly smaller than the typically expected one, $\sim 10$ kpc. Here, we are looking towards the possibility if the non-standard neutrino properties such as decay of neutrinos can enhance the Earth matter effect. In this work we show that invisible neutrino decay can potentially enhance significantly the Earth matter effect for both $\nu_e$ and $\bar{\nu}_e$ channels at the same time for both mass orderings, even if the neutrino spectra between electron and other flavors of neutrinos are very similar, which is a different feature not expected for CCSN neutrinos with standard oscillation without the decay effect.
[ { "created": "Mon, 6 Sep 2021 21:00:02 GMT", "version": "v1" } ]
2022-01-12
[ [ "Delgado", "Edwin A.", "" ], [ "Nunokawa", "Hiroshi", "" ], [ "Quiroga", "Alexander A.", "" ] ]
The observation of Earth matter effects in the spectrum of neutrinos coming from a next galactic core-collapse supernova (CCSN) could, in principle, reveal if neutrino mass ordering is normal or inverted. One of the possible ways to identify the mass ordering is through the observation of the modulations that appear in the spectrum when neutrinos travel through the Earth before they arrive at the detector. These features in the neutrino spectrum depend on two factors, the average neutrino energies, and the difference between the primary neutrino fluxes of electron and other flavors produced inside the supernova. However, recent studies indicate that the Earth matter effect for CCSN neutrinos is expected to be rather small and difficult to be observed by currently operating or planned neutrino detectors mainly because of the similarity of average energies and fluxes between electron and other flavors of neutrinos, unless the distance to CCSN is significantly smaller than the typically expected one, $\sim 10$ kpc. Here, we are looking towards the possibility if the non-standard neutrino properties such as decay of neutrinos can enhance the Earth matter effect. In this work we show that invisible neutrino decay can potentially enhance significantly the Earth matter effect for both $\nu_e$ and $\bar{\nu}_e$ channels at the same time for both mass orderings, even if the neutrino spectra between electron and other flavors of neutrinos are very similar, which is a different feature not expected for CCSN neutrinos with standard oscillation without the decay effect.
hep-ph/9707515
Christian Weiss
J. Balla, M.V. Polyakov and C. Weiss
Nucleon matrix elements of higher-twist operators from the instanton vacuum
40 pages, LaTeX, 2 Figures included using epsf
Nucl.Phys. B510 (1998) 327-364
10.1016/S0550-3213(98)00638-5
RUB-TPII-6/97
hep-ph
null
We compute the nucleon matrix elements of QCD operators of twist 3 and 4 in the instanton vacuum. We consider the operators determining 1/Q^2-power corrections to the Bjorken, Ellis-Jaffe and Gross-Llewellyn-Smith sum rules. The nucleon is described as a soliton of the effective chiral theory derived from instantons in the 1/N_c-expansion. QCD operators involving the gluon field are systematically represented by effective operators in the effective chiral theory. We find that twist-3 matrix elements are suppressed relative to twist-4 by a power of the packing fraction of the instanton medium. Numerical results for the spin-dependent (d^(2), f^(2)) and spin-independent twist-3 and 4 matrix elements are compared with results of other approaches and with experimental estimates of power corrections. The methods developed can be used to evaluate a wide range of matrix elements relevant to DIS.
[ { "created": "Wed, 30 Jul 1997 14:03:03 GMT", "version": "v1" } ]
2009-10-30
[ [ "Balla", "J.", "" ], [ "Polyakov", "M. V.", "" ], [ "Weiss", "C.", "" ] ]
We compute the nucleon matrix elements of QCD operators of twist 3 and 4 in the instanton vacuum. We consider the operators determining 1/Q^2-power corrections to the Bjorken, Ellis-Jaffe and Gross-Llewellyn-Smith sum rules. The nucleon is described as a soliton of the effective chiral theory derived from instantons in the 1/N_c-expansion. QCD operators involving the gluon field are systematically represented by effective operators in the effective chiral theory. We find that twist-3 matrix elements are suppressed relative to twist-4 by a power of the packing fraction of the instanton medium. Numerical results for the spin-dependent (d^(2), f^(2)) and spin-independent twist-3 and 4 matrix elements are compared with results of other approaches and with experimental estimates of power corrections. The methods developed can be used to evaluate a wide range of matrix elements relevant to DIS.
1701.00124
Igor Strakovsky
Yakov I. Azimov (PNPI), Igor I. Strakovsky (GWU), William J. Briscoe (GWU), and Ron L. Workman (GWU)
Legendre Analysis of Differential Distributions in Hadronic Reactions
13 pgs, 3 figs
Phys. Rev. C 95, 025205 (2017)
10.1103/PhysRevC.95.025205
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Modern experimental facilities, such as CBELSA, ELPH, JLab, MAMI and SPring-8 have provided a tremendous volume of data, often with wide energy and angular coverage, and with increasing precision. For reactions with two hadrons in the final state, these data are often presented as multiple sets of panels, with angular distributions at numerous specific energies. Such presentations have limited visual appeal, and their physical content is typically extracted through some model- dependent treatment. Instead, we explore the use of a Legendre series expansion with a relatively small number of essential coefficients. This approach has been applied in several recent experimental investigations. We present some general properties of the Legendre coefficients in the helicity framework and consider what physical information can be extracted without any model-dependent assumptions.
[ { "created": "Sat, 31 Dec 2016 15:34:32 GMT", "version": "v1" } ]
2017-03-01
[ [ "Azimov", "Yakov I.", "", "PNPI" ], [ "Strakovsky", "Igor I.", "", "GWU" ], [ "Briscoe", "William J.", "", "GWU" ], [ "Workman", "Ron L.", "", "GWU" ] ]
Modern experimental facilities, such as CBELSA, ELPH, JLab, MAMI and SPring-8 have provided a tremendous volume of data, often with wide energy and angular coverage, and with increasing precision. For reactions with two hadrons in the final state, these data are often presented as multiple sets of panels, with angular distributions at numerous specific energies. Such presentations have limited visual appeal, and their physical content is typically extracted through some model- dependent treatment. Instead, we explore the use of a Legendre series expansion with a relatively small number of essential coefficients. This approach has been applied in several recent experimental investigations. We present some general properties of the Legendre coefficients in the helicity framework and consider what physical information can be extracted without any model-dependent assumptions.
hep-ph/0512125
Enrico Meggiolaro
A. Di Giacomo, E. Meggiolaro, Yu.A. Simonov, A.I. Veselov
Dynamics of quark-gluon plasma from Field correlators
Revised version with new comments and references and corrected tables VII-IX; 34 pages + 6 figures
Phys.Atom.Nucl.70:908-924,2007
10.1134/S1063778807050146
IFUP-TH/2005-38
hep-ph hep-lat nucl-th
null
It is argued that strong dynamics in the quark-gluon plasma and bound states of quarks and gluons is mostly due to nonperturbative effects described by field correlators. The emphasis in the paper is made on two explicit calculations of these effects from the first principles: one analytic using gluelump Green's functions and another using independent lattice data on correlators. The resulting hadron spectra are investigated in the range T_c < T < 2T_c. The spectra of charmonia, bottomonia, light s-sbar mesons, glueballs and quark-gluon states calculated numerically are in general agreement with lattice MEM data. The possible role of these bound states in the thermodynamics of quark-gluon plasma is discussed.
[ { "created": "Fri, 9 Dec 2005 15:52:13 GMT", "version": "v1" }, { "created": "Thu, 22 Dec 2005 13:33:34 GMT", "version": "v2" } ]
2008-11-26
[ [ "Di Giacomo", "A.", "" ], [ "Meggiolaro", "E.", "" ], [ "Simonov", "Yu. A.", "" ], [ "Veselov", "A. I.", "" ] ]
It is argued that strong dynamics in the quark-gluon plasma and bound states of quarks and gluons is mostly due to nonperturbative effects described by field correlators. The emphasis in the paper is made on two explicit calculations of these effects from the first principles: one analytic using gluelump Green's functions and another using independent lattice data on correlators. The resulting hadron spectra are investigated in the range T_c < T < 2T_c. The spectra of charmonia, bottomonia, light s-sbar mesons, glueballs and quark-gluon states calculated numerically are in general agreement with lattice MEM data. The possible role of these bound states in the thermodynamics of quark-gluon plasma is discussed.
hep-ph/0103079
Hans Volker Klapdor
H.V. Klapdor-Kleingrothaus and B. Majorovits (MPI-Kernphysik, Heidelberg, Germany)
GENIUS and the Genius TF: A New Observatory for WIMP Dark Matter and Neutrinoless Double Beta Decay
10 pages, revtex, 4 figures, Talk was presented at 3rd International Workshop on the Identification of Dark Matter, IDM2000, York, England, September 18-22, 2000, to be publ. in proc. World Scoentific (2001). Home Page of Heidelberg Non-Accelerator Particle Physics Group (GENIUS Experiment): http://www.mpi-hd.mpg.de/non_acc/genius.html
null
10.1142/9789812811363_0076
null
hep-ph
null
The GENIUS proposal is described and some of it's physics potential is outlined. Also in the light of the contradictive results from the DAMA and CDMS experiments the Genius TF, a new experimental setup is proposed. The Genius TF could probe the DAMA evidence region using the WIMP nucleus recoil signal and WIMP annual modulation signature simultaneously. Besides that it can prove the long term feasibility of the detector technique to be implemented into the GENIUS setup and will in this sense be a first step towards the realization of the GENIUS experiment.
[ { "created": "Wed, 7 Mar 2001 18:49:19 GMT", "version": "v1" } ]
2016-11-03
[ [ "Klapdor-Kleingrothaus", "H. V.", "", "MPI-Kernphysik,\n Heidelberg, Germany" ], [ "Majorovits", "B.", "", "MPI-Kernphysik,\n Heidelberg, Germany" ] ]
The GENIUS proposal is described and some of it's physics potential is outlined. Also in the light of the contradictive results from the DAMA and CDMS experiments the Genius TF, a new experimental setup is proposed. The Genius TF could probe the DAMA evidence region using the WIMP nucleus recoil signal and WIMP annual modulation signature simultaneously. Besides that it can prove the long term feasibility of the detector technique to be implemented into the GENIUS setup and will in this sense be a first step towards the realization of the GENIUS experiment.
hep-ph/0309248
Ulf-G. Mei{\ss}ner
Ulf-G. Mei{\ss}ner
Chiral dynamics with strange quarks
10 pp, 3 figs, plenary talk, X. International Conference on Hadron Spectroscopy (HADRON '03), August 31 - September 6, 2003, Aschaffenburg, Germany
null
10.1063/1.1799775
HISKP-TH-03/20
hep-ph nucl-th
null
In the first part of the talk, I review what we know (or rather do not know) about the structure of the QCD vacuum in the presence of strange quarks. Chiral perturbation theory allows to study reactions of pions and kaons and to further sharpen our understanding of symmetry violation in QCD. I review recent progress on the description of pion-kaon scattering, in particular concerning isospin violation and the extraction of threshold and resonance parameters from Roy-Steiner equations. In the third part, it is shown how a unitary extension of chiral perturbation theory leads to novel insight into the structure of the Lambda(1405).
[ { "created": "Mon, 22 Sep 2003 14:22:08 GMT", "version": "v1" } ]
2009-11-10
[ [ "Meißner", "Ulf-G.", "" ] ]
In the first part of the talk, I review what we know (or rather do not know) about the structure of the QCD vacuum in the presence of strange quarks. Chiral perturbation theory allows to study reactions of pions and kaons and to further sharpen our understanding of symmetry violation in QCD. I review recent progress on the description of pion-kaon scattering, in particular concerning isospin violation and the extraction of threshold and resonance parameters from Roy-Steiner equations. In the third part, it is shown how a unitary extension of chiral perturbation theory leads to novel insight into the structure of the Lambda(1405).
0901.3794
Brian Glover
Brian Glover and Jong Anly Tan (College of William and Mary)
Gravity and Electroweak Symmetry Breaking in a RSI/RSII Hybrid Model
13 pages, 4 figures
Phys.Rev.D79:115012,2009
10.1103/PhysRevD.79.115012
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a hybrid RSI/RSII model in which we both solve the hierarchy problem and produce a continuum of KK graviton modes. In this model, four dimensional gravity can be reproduced and the radion mode can be stabilized. We then modify the hybrid gravity model to include SU(2)_L x SU(2)_R x U(1)_(B-L) bulk gauge fields. Electroweak symmetry is broken by the choice of appropriate boundary conditions. By adjusting the size of one region of the extra dimension, we show that the S parameter can be decreased while protecting the rho parameter from corrections. We find that as the S parameter is decreased by ~ 60%, M_Z' and M_W' stay below 1800 GeV, protecting unitarity.
[ { "created": "Mon, 26 Jan 2009 16:40:30 GMT", "version": "v1" } ]
2010-04-21
[ [ "Glover", "Brian", "", "College of William and Mary" ], [ "Tan", "Jong Anly", "", "College of William and Mary" ] ]
We present a hybrid RSI/RSII model in which we both solve the hierarchy problem and produce a continuum of KK graviton modes. In this model, four dimensional gravity can be reproduced and the radion mode can be stabilized. We then modify the hybrid gravity model to include SU(2)_L x SU(2)_R x U(1)_(B-L) bulk gauge fields. Electroweak symmetry is broken by the choice of appropriate boundary conditions. By adjusting the size of one region of the extra dimension, we show that the S parameter can be decreased while protecting the rho parameter from corrections. We find that as the S parameter is decreased by ~ 60%, M_Z' and M_W' stay below 1800 GeV, protecting unitarity.
hep-ph/9609500
Michael Kraemer
Matteo Cacciari and Michael Kr\"amer (DESY)
Prospects for Quarkonium Physics at HERA
LaTeX2e, 19 pages, 6 figures. Contribution to the proceedings of the workshop `Future Physics at HERA'
null
null
null
hep-ph
null
We work out and review prospects for future quarkonium physics at HERA. We focus on the impact of color-octet contributions and discuss how measurements at HERA can be used to test the picture of quarkonium production as developed in the context of the NRQCD factorization approach.
[ { "created": "Fri, 27 Sep 1996 06:33:59 GMT", "version": "v1" } ]
2007-05-23
[ [ "Cacciari", "Matteo", "", "DESY" ], [ "Krämer", "Michael", "", "DESY" ] ]
We work out and review prospects for future quarkonium physics at HERA. We focus on the impact of color-octet contributions and discuss how measurements at HERA can be used to test the picture of quarkonium production as developed in the context of the NRQCD factorization approach.
1212.4428
Mariana Frank
Mariana Frank (Concordia University), Levent Selbuz (Concordia University and Ankara University) and Ismail Turan (Middle East Technical University)
Neutralino and Chargino Production in U(1)' at the LHC
22 pages, 9 figures, 6 tables, to appear in Eur. Phys. J. C
null
10.1140/epjc/s10052-013-2656-7
CUMQ/HEP 164
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine the production and the decay modes of neutralinos and charginos in a softly-broken supersymmetric model with an extra Abelian symmetry U(1)'. We perform the study in a U(1)' model with a secluded sector, where the tension between the electroweak scale and developing a large enough mass for Z' is resolved by incorporating three additional SU(2) singlet fields into the model. Although the chargino sector is the same as in the MSSM, the neutralino sector of the model is very rich: five new fermion fields are added to the neutral sector bring the total neutralino states to nine. We implement the model into standard packages and perform a detailed and systematic analysis of production and decay modes at the LHC, for three different scenarios, and concentrating on final signals (1) 1 lepton+jets +MET, (2) 2 leptons+jets +MET and (3) 3 lepton+0jets +MET, and comment on the case with 0 lepton+jets +MET. We discuss backgrounds and indicate how these signals can be observed, and how the model can be distinguished from other supersymmetric model scenarios.
[ { "created": "Tue, 18 Dec 2012 17:05:27 GMT", "version": "v1" }, { "created": "Thu, 20 Dec 2012 16:50:40 GMT", "version": "v2" }, { "created": "Fri, 8 Nov 2013 08:43:49 GMT", "version": "v3" } ]
2015-06-12
[ [ "Frank", "Mariana", "", "Concordia University" ], [ "Selbuz", "Levent", "", "Concordia\n University and Ankara University" ], [ "Turan", "Ismail", "", "Middle East Technical\n University" ] ]
We examine the production and the decay modes of neutralinos and charginos in a softly-broken supersymmetric model with an extra Abelian symmetry U(1)'. We perform the study in a U(1)' model with a secluded sector, where the tension between the electroweak scale and developing a large enough mass for Z' is resolved by incorporating three additional SU(2) singlet fields into the model. Although the chargino sector is the same as in the MSSM, the neutralino sector of the model is very rich: five new fermion fields are added to the neutral sector bring the total neutralino states to nine. We implement the model into standard packages and perform a detailed and systematic analysis of production and decay modes at the LHC, for three different scenarios, and concentrating on final signals (1) 1 lepton+jets +MET, (2) 2 leptons+jets +MET and (3) 3 lepton+0jets +MET, and comment on the case with 0 lepton+jets +MET. We discuss backgrounds and indicate how these signals can be observed, and how the model can be distinguished from other supersymmetric model scenarios.
0806.3247
Alex Pomarol
Alex Pomarol and Javi Serra
Top Quark Compositeness: Feasibility and Implications
26 pages, 11 figures
Phys.Rev.D78:074026,2008
10.1103/PhysRevD.78.074026
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In models of electroweak symmetry breaking in which the SM fermions get their masses by mixing with composite states, it is natural to expect the top quark to show properties of compositeness. We study the phenomenological viability of having a mostly composite top. The strongest constraints are shown to mainly come from one-loop contributions to the T-parameter. Nevertheless, the presence of light custodial partners weakens these bounds, allowing in certain cases for a high degree of top compositeness. We find regions in the parameter space in which the T-parameter receives moderate positive contributions, favoring the electroweak fit of this type of models. We also study the implications of having a composite top at the LHC, focusing on the process pp-> t\bar t t\bar t (b\bar b) whose cross-section is enhanced at high-energies.
[ { "created": "Thu, 19 Jun 2008 17:27:25 GMT", "version": "v1" }, { "created": "Mon, 6 Oct 2008 14:30:36 GMT", "version": "v2" } ]
2010-03-19
[ [ "Pomarol", "Alex", "" ], [ "Serra", "Javi", "" ] ]
In models of electroweak symmetry breaking in which the SM fermions get their masses by mixing with composite states, it is natural to expect the top quark to show properties of compositeness. We study the phenomenological viability of having a mostly composite top. The strongest constraints are shown to mainly come from one-loop contributions to the T-parameter. Nevertheless, the presence of light custodial partners weakens these bounds, allowing in certain cases for a high degree of top compositeness. We find regions in the parameter space in which the T-parameter receives moderate positive contributions, favoring the electroweak fit of this type of models. We also study the implications of having a composite top at the LHC, focusing on the process pp-> t\bar t t\bar t (b\bar b) whose cross-section is enhanced at high-energies.
1904.10285
Rui-Lin Zhu
Ruilin Zhu, Xuejie Liu, Hongxia Huang, Cong-Feng Qiao
Analyzing doubly heavy tetra- and penta-quark states by variational method
11 pages, 2 figures, 7 tables; added new discussions
Phys.Lett. B797(2019),134869
10.1016/j.physletb.2019.134869
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by the very recent observations of hidden charm pentaquarks $P_c(4312)^+$, $P_c(4440)^+$ and $P_c(4457)^+$ of the LHCb Collaboration, we systematically study the spectra of the doubly-heavy (with or without charm/bottom numbers) pentaquarks and tetraquarks in non-relativistic constituent quark model. The model independent variational method is employed to solve the Schr\"odinger equation, where the test functions adopted are symmetric for the light quarks. In our study, the $P_c(4312)^+$ may be assigned as the ground state with spin-parity $\frac{1}{2}^-$ or $\frac{3}{2}^-$, while the $P_c(4440)^+$ and $P_c(4457)^+$ may be assigned as the excited states with $\frac{1}{2}^-$, which might all belong to the sextet with $s_{c\bar{c}}=1$ and $s_\ell=\frac{3}{2}$. It is notable that our working framework is quite similar to that of Hydrogen molecule, but with different potential structure. We also classify these pentaquarks and tetraquarks in light of the heavy quark symmetry and their decay properties are analyzed. Several promising channels for the observation of doubly-heavy pentaquarks and doubly-heavy tetraquarks in experiment are proposed.
[ { "created": "Tue, 23 Apr 2019 12:43:02 GMT", "version": "v1" }, { "created": "Fri, 16 Aug 2019 16:09:59 GMT", "version": "v2" } ]
2019-09-04
[ [ "Zhu", "Ruilin", "" ], [ "Liu", "Xuejie", "" ], [ "Huang", "Hongxia", "" ], [ "Qiao", "Cong-Feng", "" ] ]
Motivated by the very recent observations of hidden charm pentaquarks $P_c(4312)^+$, $P_c(4440)^+$ and $P_c(4457)^+$ of the LHCb Collaboration, we systematically study the spectra of the doubly-heavy (with or without charm/bottom numbers) pentaquarks and tetraquarks in non-relativistic constituent quark model. The model independent variational method is employed to solve the Schr\"odinger equation, where the test functions adopted are symmetric for the light quarks. In our study, the $P_c(4312)^+$ may be assigned as the ground state with spin-parity $\frac{1}{2}^-$ or $\frac{3}{2}^-$, while the $P_c(4440)^+$ and $P_c(4457)^+$ may be assigned as the excited states with $\frac{1}{2}^-$, which might all belong to the sextet with $s_{c\bar{c}}=1$ and $s_\ell=\frac{3}{2}$. It is notable that our working framework is quite similar to that of Hydrogen molecule, but with different potential structure. We also classify these pentaquarks and tetraquarks in light of the heavy quark symmetry and their decay properties are analyzed. Several promising channels for the observation of doubly-heavy pentaquarks and doubly-heavy tetraquarks in experiment are proposed.
hep-ph/9806365
Nico Schoonderwoerd
N.C.J. Schoonderwoerd and B.L.G. Bakker (Vrije Universiteit, Amsterdam) and V.A. Karmanov (Lebedev Physical Institute, Moscow)
Entanglement of Fock-space expansion and covariance in light-front Hamiltonian dynamics
17 pages, revtex, 14 figures, submitted to Phys.Rev.C
Phys.Rev.C58:3093-3108,1998
10.1103/PhysRevC.58.3093
VUTH 98-20
hep-ph hep-th nucl-th
null
We investigate in a model with scalar ``nucleons'' and mesons the contributions of higher Fock states that are neglected in the ladder approximation of the Lippmann-Schwinger equation. This leads to a breaking of covariance, both in light-front and in instant-form Hamiltonian dynamics. The lowest Fock sector neglected has two mesons in the intermediate state and corresponds to the stretched box. First we show in a simplified example that the contributions of higher Fock states are much smaller on the light-front than in instant-form dynamics. Then we show for a scattering amplitude above threshold that the stretched boxes are small, however, necessary to retain covariance. For an off energy-shell amplitude covariance is not necessarily maintained and this is confirmed by our calculations. Again, the stretched boxes are found to be small.
[ { "created": "Mon, 15 Jun 1998 07:49:45 GMT", "version": "v1" } ]
2008-11-26
[ [ "Schoonderwoerd", "N. C. J.", "", "Vrije Universiteit,\n Amsterdam" ], [ "Bakker", "B. L. G.", "", "Vrije Universiteit,\n Amsterdam" ], [ "Karmanov", "V. A.", "", "Lebedev Physical Institute, Moscow" ] ]
We investigate in a model with scalar ``nucleons'' and mesons the contributions of higher Fock states that are neglected in the ladder approximation of the Lippmann-Schwinger equation. This leads to a breaking of covariance, both in light-front and in instant-form Hamiltonian dynamics. The lowest Fock sector neglected has two mesons in the intermediate state and corresponds to the stretched box. First we show in a simplified example that the contributions of higher Fock states are much smaller on the light-front than in instant-form dynamics. Then we show for a scattering amplitude above threshold that the stretched boxes are small, however, necessary to retain covariance. For an off energy-shell amplitude covariance is not necessarily maintained and this is confirmed by our calculations. Again, the stretched boxes are found to be small.
1007.0282
Kingman Cheung
Kingman Cheung, Jeonghyeon Song, Po-Yan Tseng
Cosmic positron and antiproton constraints on the gauge-Higgs Dark Matter
13 pages, 3 figures
JCAP 1009:023,2010
10.1088/1475-7516/2010/09/023
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the cosmic ray positron and antiproton spectra of a gauge-Higgs dark matter candidate in a warped five-dimensional $SO(5) \times U(1)$ gauge-Higgs unification model. The stability of the gauge-Higgs boson is guaranteed by the H parity under which only the Higgs boson is odd at low energy. The 4-point vertices of HHW^+W^- and HHZZ, allowed by H parity conservation, have the same magnitude as in the standard model, which yields efficient annihilation rate for $m_H > m_W$. The most dominant annihilation channel is $H H \to W^+ W^-$ followed by the subsequent decays of the $W$ bosons into positrons or quarks, which undergo fragmentation into antiproton. Comparing with the observed positron and antiproton spectra with the PAMALA and Fermi/LAT, we found that the Higgs boson mass cannot be larger than 90 GeV, in order not to overrun the observations. Together with the constraint on not overclosing the Universe, the valid range of the dark matter mass is restricted to 70-90 GeV.
[ { "created": "Fri, 2 Jul 2010 00:25:31 GMT", "version": "v1" } ]
2014-11-21
[ [ "Cheung", "Kingman", "" ], [ "Song", "Jeonghyeon", "" ], [ "Tseng", "Po-Yan", "" ] ]
We calculate the cosmic ray positron and antiproton spectra of a gauge-Higgs dark matter candidate in a warped five-dimensional $SO(5) \times U(1)$ gauge-Higgs unification model. The stability of the gauge-Higgs boson is guaranteed by the H parity under which only the Higgs boson is odd at low energy. The 4-point vertices of HHW^+W^- and HHZZ, allowed by H parity conservation, have the same magnitude as in the standard model, which yields efficient annihilation rate for $m_H > m_W$. The most dominant annihilation channel is $H H \to W^+ W^-$ followed by the subsequent decays of the $W$ bosons into positrons or quarks, which undergo fragmentation into antiproton. Comparing with the observed positron and antiproton spectra with the PAMALA and Fermi/LAT, we found that the Higgs boson mass cannot be larger than 90 GeV, in order not to overrun the observations. Together with the constraint on not overclosing the Universe, the valid range of the dark matter mass is restricted to 70-90 GeV.
0704.1256
Alon Faraggi
Claudio Coriano, Alon E. Faraggi, Marco Guzzi
A Novel String Derived Z' With Stable Proton, Light-Neutrinos and R-parity violation
16 pages. Standard LaTex. minor changes
Eur.Phys.J.C53:421-428,2008
10.1140/epjc/s10052-007-0469-2
null
hep-ph hep-th
null
The Standard Model indicates the realization of grand unified structures in nature, and can only be viewed as an effective theory below a higher energy cutoff. While the renormalizable Standard Model forbids proton decay mediating operators due to accidental global symmetries, many extensions of the Standard Model introduce such dimension four, five and six operators. Furthermore, quantum gravity effects are expected to induce proton instability, indicating that the higher energy cutoff scale must be above 10^{16}GeV. Quasi-realistic heterotic string models provide the arena to explore how perturbative quantum gravity affects the particle physics phenomenology. An appealing explanation for the proton longevity is provided by the existence of an Abelian gauge symmetry that suppresses the proton decay mediating operators. Additionally, such a low-scale U(1) symmetry should: allow the suppression of the left-handed neutrino masses by a seesaw mechanism; allow fermion Yukawa couplings to the electroweak Higgs doublets; be anomaly free; be family universal. These requirements render the existence of such U(1) symmetries in quasi-realistic heterotic string models highly non-trivial. We demonstrate the existence of a U(1) symmetry that satisfies all of the above requirements in a class of left-right symmetric heterotic string models in the free fermionic formulation. The existence of the extra Z' in the energy range accessible to future experiments is motivated by the requirement of adequate suppression of proton decay mediation. We further show that while the extra U(1) forbids dimension four baryon number violating operators it allows dimension four lepton number violating operators and R-parity violation.
[ { "created": "Tue, 10 Apr 2007 15:13:07 GMT", "version": "v1" }, { "created": "Wed, 10 Oct 2007 08:39:41 GMT", "version": "v2" } ]
2008-11-26
[ [ "Coriano", "Claudio", "" ], [ "Faraggi", "Alon E.", "" ], [ "Guzzi", "Marco", "" ] ]
The Standard Model indicates the realization of grand unified structures in nature, and can only be viewed as an effective theory below a higher energy cutoff. While the renormalizable Standard Model forbids proton decay mediating operators due to accidental global symmetries, many extensions of the Standard Model introduce such dimension four, five and six operators. Furthermore, quantum gravity effects are expected to induce proton instability, indicating that the higher energy cutoff scale must be above 10^{16}GeV. Quasi-realistic heterotic string models provide the arena to explore how perturbative quantum gravity affects the particle physics phenomenology. An appealing explanation for the proton longevity is provided by the existence of an Abelian gauge symmetry that suppresses the proton decay mediating operators. Additionally, such a low-scale U(1) symmetry should: allow the suppression of the left-handed neutrino masses by a seesaw mechanism; allow fermion Yukawa couplings to the electroweak Higgs doublets; be anomaly free; be family universal. These requirements render the existence of such U(1) symmetries in quasi-realistic heterotic string models highly non-trivial. We demonstrate the existence of a U(1) symmetry that satisfies all of the above requirements in a class of left-right symmetric heterotic string models in the free fermionic formulation. The existence of the extra Z' in the energy range accessible to future experiments is motivated by the requirement of adequate suppression of proton decay mediation. We further show that while the extra U(1) forbids dimension four baryon number violating operators it allows dimension four lepton number violating operators and R-parity violation.
1407.4590
Mikhail Braun
M.A.Braun, C.Pajares, V.V.Vechernin
Ridge from Strings
null
null
10.1140/epja/i2015-15044-9
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the colour string picture with fusion and percolation it is shown that long range azimuthal-rapidity correlations (ridge) can arise from the superposition of many events with exchange of clusters of different number of strings and not from a single event. Relation of the ridge with the flow harmonics coefficients is derived. By direct Monte-Carlo simulations, in the technique previously used to calculate these coefficients, ridge correlations are calculated for AA, pA and pp collisions. The azimuthal anisotropy follows from the assumed quenching of the emitted particles in the strong colour fields inside string clusters. It is confirmed that in pp collisions the ridge structure only appears in rare events with abnormally high multiplicity. Comarison with the experimental data shows a good agreement. Also a good agreement is found for pPb collisions. For AA collisions a reasonable agreement is found for both near-side and away-side angular correlations although it worsens at intermediate angles.
[ { "created": "Thu, 17 Jul 2014 07:50:09 GMT", "version": "v1" } ]
2015-06-22
[ [ "Braun", "M. A.", "" ], [ "Pajares", "C.", "" ], [ "Vechernin", "V. V.", "" ] ]
In the colour string picture with fusion and percolation it is shown that long range azimuthal-rapidity correlations (ridge) can arise from the superposition of many events with exchange of clusters of different number of strings and not from a single event. Relation of the ridge with the flow harmonics coefficients is derived. By direct Monte-Carlo simulations, in the technique previously used to calculate these coefficients, ridge correlations are calculated for AA, pA and pp collisions. The azimuthal anisotropy follows from the assumed quenching of the emitted particles in the strong colour fields inside string clusters. It is confirmed that in pp collisions the ridge structure only appears in rare events with abnormally high multiplicity. Comarison with the experimental data shows a good agreement. Also a good agreement is found for pPb collisions. For AA collisions a reasonable agreement is found for both near-side and away-side angular correlations although it worsens at intermediate angles.
hep-ph/0101103
Edmond Iancu
Jean-Paul Blaizot and Edmond Iancu
The Quark-Gluon Plasma: Collective Dynamics and Hard Thermal Loops
210 pages, 33 figures, submitted to Physics Reports
Phys.Rept. 359 (2002) 355-528
10.1016/S0370-1573(01)00061-8
SACLAY-T01/005, CERN-TH/2000
hep-ph
null
We present a unified description of the high temperature phase of QCD, the so-called quark-gluon plasma, in a regime where the effective gauge coupling $g$ is sufficiently small to allow for weak coupling calculations. The main focuss is the construction of the effective theory for the collective excitations which develop at a typical scale $gT$, which is well separated from the typical energy of single particle excitations which is the temperature $T$. We show that the plasma particles provide a source for long wavelength oscillations of average fields which carry the quantum numbers of the plasma constituents, the quarks and the gluons. To leading order in $g$, the plasma particles obey simple gauge-covariant kinetic equations, whose derivation from the general Dyson-Schwinger equations is outlined. As a by-product, the ``hard thermal loops'' emerge naturally in a physically transparent framework. We show that the collective excitations can be described in terms of classical fields, and develop for these a Hamiltonian formalism. The effect of collisions among the hard particles is also studied, in particular in relation with the effective theory for ultrasoft excitations, with momenta $\sim g^2T$.
[ { "created": "Wed, 10 Jan 2001 19:10:50 GMT", "version": "v1" } ]
2009-11-07
[ [ "Blaizot", "Jean-Paul", "" ], [ "Iancu", "Edmond", "" ] ]
We present a unified description of the high temperature phase of QCD, the so-called quark-gluon plasma, in a regime where the effective gauge coupling $g$ is sufficiently small to allow for weak coupling calculations. The main focuss is the construction of the effective theory for the collective excitations which develop at a typical scale $gT$, which is well separated from the typical energy of single particle excitations which is the temperature $T$. We show that the plasma particles provide a source for long wavelength oscillations of average fields which carry the quantum numbers of the plasma constituents, the quarks and the gluons. To leading order in $g$, the plasma particles obey simple gauge-covariant kinetic equations, whose derivation from the general Dyson-Schwinger equations is outlined. As a by-product, the ``hard thermal loops'' emerge naturally in a physically transparent framework. We show that the collective excitations can be described in terms of classical fields, and develop for these a Hamiltonian formalism. The effect of collisions among the hard particles is also studied, in particular in relation with the effective theory for ultrasoft excitations, with momenta $\sim g^2T$.
1310.0356
Andrey Katz
Zhenyu Han and Andrey Katz
Stealth Stops and Spin Correlation: A Snowmass White Paper
Contributed to Snowmass Community Study 2013
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Stops with the mass nearly degenerate with the top mass, decaying into tops and soft neutralinos, are usually dubbed "stealth stops". Their kinematics looks very similar to that of the standard tops events, which leads to events with little or no excess of missing transverse energy. This complicates the probing of this region of the stop parameter space by hadron colliders, rendering the application of standard searching techniques challenging. In this Snowmass white paper we reanalyze the spin correlation approach to the search of stealth stops, focusing on the feasibility of this search at the 14 TeV LHC. We find, while the statistical limitations significantly shrink compared to the low-luminosity 8 TeV run, the systematic PDF uncertainties pose the main obstacle. We show that the current understanding of PDFs probably does not allow us to talk about top and stop discrimination via spin correlation in the inclusive sample. On the other hand the systematic uncertainties significantly shrink if only events with low center of mass energy are considered, rendering the search in this region feasible.
[ { "created": "Tue, 1 Oct 2013 15:44:47 GMT", "version": "v1" } ]
2013-10-02
[ [ "Han", "Zhenyu", "" ], [ "Katz", "Andrey", "" ] ]
Stops with the mass nearly degenerate with the top mass, decaying into tops and soft neutralinos, are usually dubbed "stealth stops". Their kinematics looks very similar to that of the standard tops events, which leads to events with little or no excess of missing transverse energy. This complicates the probing of this region of the stop parameter space by hadron colliders, rendering the application of standard searching techniques challenging. In this Snowmass white paper we reanalyze the spin correlation approach to the search of stealth stops, focusing on the feasibility of this search at the 14 TeV LHC. We find, while the statistical limitations significantly shrink compared to the low-luminosity 8 TeV run, the systematic PDF uncertainties pose the main obstacle. We show that the current understanding of PDFs probably does not allow us to talk about top and stop discrimination via spin correlation in the inclusive sample. On the other hand the systematic uncertainties significantly shrink if only events with low center of mass energy are considered, rendering the search in this region feasible.
hep-ph/0108266
Christof Wetterich
C.Wetterich
Cosmon dark matter?
Published version,correction in appendix A, 43 pages, LaTex
Phys.Rev. D65 (2002) 123512
10.1103/PhysRevD.65.123512
HD-THEP-01-36
hep-ph astro-ph
null
We investigate if the fluctuations of the scalar field mediating quintessence -- the cosmon -- can play an important role in cosmology. Small fluctuations with short wavelength behave similar to a relativistic gas. In contrast, the contribution to the energy density from horizon size fluctuations may decrease less rapidly than radiation. We discuss the possibility that the cosmon fluctuations grow nonlinearly, form lumps and constitute the clustering dark matter of the universe. Cosmon dark matter would lead to interesting consequences for the equation of state and the coupling between quintessence and dark matter.
[ { "created": "Fri, 31 Aug 2001 11:15:31 GMT", "version": "v1" }, { "created": "Tue, 18 Dec 2001 10:52:48 GMT", "version": "v2" }, { "created": "Mon, 18 Mar 2002 12:34:52 GMT", "version": "v3" } ]
2009-11-07
[ [ "Wetterich", "C.", "" ] ]
We investigate if the fluctuations of the scalar field mediating quintessence -- the cosmon -- can play an important role in cosmology. Small fluctuations with short wavelength behave similar to a relativistic gas. In contrast, the contribution to the energy density from horizon size fluctuations may decrease less rapidly than radiation. We discuss the possibility that the cosmon fluctuations grow nonlinearly, form lumps and constitute the clustering dark matter of the universe. Cosmon dark matter would lead to interesting consequences for the equation of state and the coupling between quintessence and dark matter.
0909.3094
Brooks Thomas
Ethan Dolle, Xinyu Miao, Shufang Su, Brooks Thomas
Dilepton Signals in the Inert Doublet Model
21 pages, ReVTeX, 3 figures, 5 tables
Phys.Rev.D81:035003,2010
10.1103/PhysRevD.81.035003
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Inert Doublet Model is one of the simplest and most versatile scenarios for physics beyond the Standard Model. In this work, we examine the prospects for detecting the additional fields of this model at the LHC in the dilepton channel. We investigate a wide variety of theoretically- and phenomenologically-motivated benchmark scenarios, and show that within regions of model parameter space in which the dark-matter candidate is relatively light (between 40 and 80 GeV) and the mass splitting between the neutral scalars is also roughly 40 - 80 GeV, a signal at the 3 sigma to 12 sigma significance level can be observed with 100 fb^-1 of integrated luminosity. In addition, even if the mass splitting between the neutral scalars is larger than M_Z, a signal of more than 3 sigma can be observed as long as the mass of the dark matter candidate is around 40 GeV.
[ { "created": "Thu, 17 Sep 2009 18:44:56 GMT", "version": "v1" } ]
2010-04-06
[ [ "Dolle", "Ethan", "" ], [ "Miao", "Xinyu", "" ], [ "Su", "Shufang", "" ], [ "Thomas", "Brooks", "" ] ]
The Inert Doublet Model is one of the simplest and most versatile scenarios for physics beyond the Standard Model. In this work, we examine the prospects for detecting the additional fields of this model at the LHC in the dilepton channel. We investigate a wide variety of theoretically- and phenomenologically-motivated benchmark scenarios, and show that within regions of model parameter space in which the dark-matter candidate is relatively light (between 40 and 80 GeV) and the mass splitting between the neutral scalars is also roughly 40 - 80 GeV, a signal at the 3 sigma to 12 sigma significance level can be observed with 100 fb^-1 of integrated luminosity. In addition, even if the mass splitting between the neutral scalars is larger than M_Z, a signal of more than 3 sigma can be observed as long as the mass of the dark matter candidate is around 40 GeV.
1907.02366
Mathieu Pellen
Ansgar Denner, Stefan Dittmaier, Mathieu Pellen, Christopher Schwan
Low-virtuality photon transitions $\gamma^*\to f\bar f$ and the photon-to-jet conversion function
13 pages, 7 pdf-figures. Matches the journal version
null
10.1016/j.physletb.2019.134951
Cavendish-HEP-19/20, FR-PHENO-2019-009, TIF-UNIMI-2019-10
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The calculation of electroweak corrections to processes with jets in the final state involves contributions of low-virtuality photons leading to jets in the final state via the singular splitting $\gamma^* \to q\bar q$. These singularities can be absorbed into a photon-to-jet "fragmentation function", better called "conversion function", since the physical final state is any hadronic activity rather than an identified hadron. Using unitarity and a dispersion relation, we relate this $\gamma^* \to q\bar q$ conversion contribution to an integral over the imaginary part of the hadronic vacuum polarization and thus to the experimentally known quantity $\Delta\alpha^{(5)}_{\mathrm{had}}(M^2_{\rm Z})$. Therefore no unknown non-perturbative contribution remains that has to be taken from experiment. We also describe practical procedures following subtraction and phase-space-slicing approaches for isolating and cancelling the $\gamma^* \to q\bar q$ singularities against the photon-to-jet conversion function. The production of Z+jet at the LHC is considered as an example, where the photon-to-jet conversion is part of a correction of the order $\alpha^2/\alpha_{\rm s}$ relative to the leading-order cross section.
[ { "created": "Thu, 4 Jul 2019 12:32:36 GMT", "version": "v1" }, { "created": "Tue, 24 Sep 2019 02:38:18 GMT", "version": "v2" } ]
2019-09-25
[ [ "Denner", "Ansgar", "" ], [ "Dittmaier", "Stefan", "" ], [ "Pellen", "Mathieu", "" ], [ "Schwan", "Christopher", "" ] ]
The calculation of electroweak corrections to processes with jets in the final state involves contributions of low-virtuality photons leading to jets in the final state via the singular splitting $\gamma^* \to q\bar q$. These singularities can be absorbed into a photon-to-jet "fragmentation function", better called "conversion function", since the physical final state is any hadronic activity rather than an identified hadron. Using unitarity and a dispersion relation, we relate this $\gamma^* \to q\bar q$ conversion contribution to an integral over the imaginary part of the hadronic vacuum polarization and thus to the experimentally known quantity $\Delta\alpha^{(5)}_{\mathrm{had}}(M^2_{\rm Z})$. Therefore no unknown non-perturbative contribution remains that has to be taken from experiment. We also describe practical procedures following subtraction and phase-space-slicing approaches for isolating and cancelling the $\gamma^* \to q\bar q$ singularities against the photon-to-jet conversion function. The production of Z+jet at the LHC is considered as an example, where the photon-to-jet conversion is part of a correction of the order $\alpha^2/\alpha_{\rm s}$ relative to the leading-order cross section.
1501.07809
John D. Swain
A.Widom, J. Swain, and Y. Srivastava
A Quantum Phase Transition in the Cosmic Ray Energy Distribution
null
null
null
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We here argue that the "knee" of the cosmic ray energy distribution at $E_c \sim 1$ PeV represents a second order phase transition of cosmic proportions. The discontinuity of the heat capacity per cosmic ray particle is given by $\Delta c=0.450196\ k_B$. However the idea of a deeper critical point singularity cannot be ruled out by present accuracy in neither theory nor experiment. The quantum phase transition consists of cosmic rays dominated by bosons for the low temperature phase E<E_c and dominated by fermions for high temperature phase $E > E_c$. The low temperature phase arises from those nuclei described by the usual and conventional collective boson models of nuclear physics. The high temperature phase is dominated by protons. The transition energy $E_c$ may be estimated in terms of the photo-disintegration of nuclei.
[ { "created": "Thu, 1 Jan 2015 03:18:22 GMT", "version": "v1" }, { "created": "Sat, 7 Feb 2015 23:51:59 GMT", "version": "v2" } ]
2015-02-10
[ [ "Widom", "A.", "" ], [ "Swain", "J.", "" ], [ "Srivastava", "Y.", "" ] ]
We here argue that the "knee" of the cosmic ray energy distribution at $E_c \sim 1$ PeV represents a second order phase transition of cosmic proportions. The discontinuity of the heat capacity per cosmic ray particle is given by $\Delta c=0.450196\ k_B$. However the idea of a deeper critical point singularity cannot be ruled out by present accuracy in neither theory nor experiment. The quantum phase transition consists of cosmic rays dominated by bosons for the low temperature phase E<E_c and dominated by fermions for high temperature phase $E > E_c$. The low temperature phase arises from those nuclei described by the usual and conventional collective boson models of nuclear physics. The high temperature phase is dominated by protons. The transition energy $E_c$ may be estimated in terms of the photo-disintegration of nuclei.
hep-ph/0312187
Pelaez
J. R. Pelaez (1) and F. J. Yndurain (2) ((1) U. Complutense, Madrid. (2) U. Autonoma, Madrid)
Regge analysis of pion-pion (and pion-kaon) scattering for energy s^{1/2}>1.4 GeV
New section added, extending the pion-nucleon and nucleon nucleon Regge description to Multi TeV energies. Conclusions on pion-pion scattering unchanged
Phys.Rev.D69:114001,2004
10.1103/PhysRevD.69.114001
FTUAM/03-19
hep-ph nucl-th
null
We perform a detailed Regge analysis of NN, pion-N and pion-pion scattering. From it, we find expressions that represent the pion-pion scattering amplitudes with an accuracy of a few percent, for exchange of isospin zero, and $\sim15%$ for exchange of isospin 1, and this for energies s^{1/2}> 1.4 GeV and for momentum transfers |t|^{1/2}< 0.4 GeV. These Regge formulas are perfectly compatible with the low energy (s^{1/2}< 1.4 GeV) scattering amplitudes deduced from pion-pion phase shift analyses as well as with higher energy (s^{1/2}>1.4 GeV) experimental pion-pion cross sections. They are also compatible with NN and pion-N experimental cross sections using factorization, a property that we check with great precision. This contrasts with results from phase shift analyses of the pion-pion scattering amplitude which bear little resemblance to reality in the region $1.4<s^{1/2}<2 GeV$, as they are not well defined and increasingly violate a number of physical requirements as energy grows. Pion-kaon scattering is also considered, and we present a Regge analysis for these processes valid for energies s^{1/2}>1.7 GeV. As a byproduct of our analysis we present also a fit of $NN$, $\pi N$ and $KN$ cross sections valid from c.m. kinetic energy $E_{\rm kin}\simeq1$ GeV to multi TeV energies.
[ { "created": "Mon, 15 Dec 2003 17:20:52 GMT", "version": "v1" }, { "created": "Mon, 9 Feb 2004 19:45:10 GMT", "version": "v2" } ]
2011-07-19
[ [ "Pelaez", "J. R.", "" ], [ "Yndurain", "F. J.", "" ] ]
We perform a detailed Regge analysis of NN, pion-N and pion-pion scattering. From it, we find expressions that represent the pion-pion scattering amplitudes with an accuracy of a few percent, for exchange of isospin zero, and $\sim15%$ for exchange of isospin 1, and this for energies s^{1/2}> 1.4 GeV and for momentum transfers |t|^{1/2}< 0.4 GeV. These Regge formulas are perfectly compatible with the low energy (s^{1/2}< 1.4 GeV) scattering amplitudes deduced from pion-pion phase shift analyses as well as with higher energy (s^{1/2}>1.4 GeV) experimental pion-pion cross sections. They are also compatible with NN and pion-N experimental cross sections using factorization, a property that we check with great precision. This contrasts with results from phase shift analyses of the pion-pion scattering amplitude which bear little resemblance to reality in the region $1.4<s^{1/2}<2 GeV$, as they are not well defined and increasingly violate a number of physical requirements as energy grows. Pion-kaon scattering is also considered, and we present a Regge analysis for these processes valid for energies s^{1/2}>1.7 GeV. As a byproduct of our analysis we present also a fit of $NN$, $\pi N$ and $KN$ cross sections valid from c.m. kinetic energy $E_{\rm kin}\simeq1$ GeV to multi TeV energies.
hep-ph/0604219
Alex Gomes Dias
Alex Gomes Dias
Neutrino Mass Through Concomitant Breakdown of the U(1) Chiral and Scale Symmetries
20 pages, 1 figure
Phys.Rev. D73 (2006) 096002
null
null
hep-ph hep-th
null
The possibility of generating neutrino mass through see-saw mechanism involving U(1) chiral Peccei-Quinn and scale symmetries breakdown is discussed. We consider a generic scale invariant model which has three Majorana fermions and a complex scalar singlet, which might be the one responsible for an invisible axion, and we perform a summation of all leading logarithmic radiative corrections to the tree level potential. The effective potential so obtained is stable and drives the scalar field to a nonzero vacuum expectation value according to the Coleman-Weinberg mechanism. As a result, right-handed neutrinos gain mass at the Peccei-Quinn scale which is suggestive for explaining very light active neutrinos. We illustrate the whole idea with the addition of the Standard Model, and also a SU(3)$_L\otimesU(1)_X$ model in which the subgroup SU(2)$_L\otimesU(1)_Y$ is constrained to be broken as an effect of the effective potential. This last model presents electric charge quantization as well.
[ { "created": "Tue, 25 Apr 2006 22:19:19 GMT", "version": "v1" } ]
2007-05-23
[ [ "Dias", "Alex Gomes", "" ] ]
The possibility of generating neutrino mass through see-saw mechanism involving U(1) chiral Peccei-Quinn and scale symmetries breakdown is discussed. We consider a generic scale invariant model which has three Majorana fermions and a complex scalar singlet, which might be the one responsible for an invisible axion, and we perform a summation of all leading logarithmic radiative corrections to the tree level potential. The effective potential so obtained is stable and drives the scalar field to a nonzero vacuum expectation value according to the Coleman-Weinberg mechanism. As a result, right-handed neutrinos gain mass at the Peccei-Quinn scale which is suggestive for explaining very light active neutrinos. We illustrate the whole idea with the addition of the Standard Model, and also a SU(3)$_L\otimesU(1)_X$ model in which the subgroup SU(2)$_L\otimesU(1)_Y$ is constrained to be broken as an effect of the effective potential. This last model presents electric charge quantization as well.
1001.4166
Pol Bernard Gossiaux
P.B. Gossiaux, J. Aichelin, T. Gousset and V. Guiho
Competition of Heavy Quark Radiative and Collisional Energy Loss in Deconfined Matter
8 pages, extended to 11 pages for v2; accepted for publication in Journal of Physics G
J Phys. G 37 (2010) 094019
10.1088/0954-3899/37/9/094019
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We extend our recently advanced model on collisional energy loss of heavy quarks in a quark gluon plasma (QGP) by including radiative energy loss. We discuss the approach and present first preliminary results. We show that present data on nuclear modification factor of non photonic single electrons hardly permit to distinguish between those 2 energy loss mechanisms.
[ { "created": "Sat, 23 Jan 2010 16:07:59 GMT", "version": "v1" }, { "created": "Mon, 10 May 2010 16:53:41 GMT", "version": "v2" } ]
2013-07-22
[ [ "Gossiaux", "P. B.", "" ], [ "Aichelin", "J.", "" ], [ "Gousset", "T.", "" ], [ "Guiho", "V.", "" ] ]
We extend our recently advanced model on collisional energy loss of heavy quarks in a quark gluon plasma (QGP) by including radiative energy loss. We discuss the approach and present first preliminary results. We show that present data on nuclear modification factor of non photonic single electrons hardly permit to distinguish between those 2 energy loss mechanisms.
2404.00087
David Frenklakh
Adrien Florio, David Frenklakh, Kazuki Ikeda, Dmitri E. Kharzeev, Vladimir Korepin, Shuzhe Shi and Kwangmin Yu
Quantum simulation of entanglement and hadronization in jet production: lessons from the massive Schwinger model
10 pages, 12 figures
null
null
null
hep-ph hep-th nucl-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The possible link between entanglement and thermalization, and the dynamics of hadronization are addressed by studying the real-time response of the massive Schwinger model coupled to external sources. This setup mimics the production and fragmentation of quark jets, as the Schwinger model and QCD share the properties of confinement and chiral symmetry breaking. By using quantum simulations on classical hardware, we study the entanglement between the produced jets, and observe the growth of the corresponding entanglement entropy in time. This growth arises from the increased number of contributing eigenstates of the reduced density matrix with sufficiently large and close eigenvalues. We also investigate the physical nature of these eigenstates, and find that at early times they correspond to fermionic Fock states. We then observe the transition from these fermionic Fock states to meson-like bound states as a function of time. In other words, we observe how hadronization develops in real time. At late times, the local observables at mid-rapidity (such as the fermion density and the electric field) approach approximately constant values, suggesting the onset of equilibrium and approach to thermalization.
[ { "created": "Fri, 29 Mar 2024 18:00:00 GMT", "version": "v1" } ]
2024-04-02
[ [ "Florio", "Adrien", "" ], [ "Frenklakh", "David", "" ], [ "Ikeda", "Kazuki", "" ], [ "Kharzeev", "Dmitri E.", "" ], [ "Korepin", "Vladimir", "" ], [ "Shi", "Shuzhe", "" ], [ "Yu", "Kwangmin", "" ] ]
The possible link between entanglement and thermalization, and the dynamics of hadronization are addressed by studying the real-time response of the massive Schwinger model coupled to external sources. This setup mimics the production and fragmentation of quark jets, as the Schwinger model and QCD share the properties of confinement and chiral symmetry breaking. By using quantum simulations on classical hardware, we study the entanglement between the produced jets, and observe the growth of the corresponding entanglement entropy in time. This growth arises from the increased number of contributing eigenstates of the reduced density matrix with sufficiently large and close eigenvalues. We also investigate the physical nature of these eigenstates, and find that at early times they correspond to fermionic Fock states. We then observe the transition from these fermionic Fock states to meson-like bound states as a function of time. In other words, we observe how hadronization develops in real time. At late times, the local observables at mid-rapidity (such as the fermion density and the electric field) approach approximately constant values, suggesting the onset of equilibrium and approach to thermalization.
2005.11265
Alessio Mangoni PhD
Rinaldo Baldini Ferroli and Alessio Mangoni and Simone Pacetti and Kai Zhu
Amplitudes separation and strong-electromagnetic relative phase in the $\psi(2S)$ decays into baryons
7 pages, 3 figures
Phys. Rev. D 103, 016005 (2021)
10.1103/PhysRevD.103.016005
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The strong, electromagnetic and mixed strong-electromagnetic amplitudes of the $\psi(2S)$ decays into baryon-anti-baryon pairs have been obtained by exploiting all available data sets in the framework of an effective Lagrangian model. We observed that at the $\psi(2S)$ mass the QCD regime is not completely perturbative, as can be inferred by the relative strength of the strong and the mixed strong-electromagnetic amplitudes. Recently a similar conclusion has been reached also for the $J/\psi$ decays. The relative phase between the strong and the electromagnetic amplitudes is $\varphi = (58\pm 8)^\circ$, to be compared with $\varphi = (73\pm 8)^\circ$ obtained for the $J/\psi$. On the other hand, in the case of the $\psi(2S)$ meson, different values of the ratio between strong and mixed strong-electromagnetic amplitudes are phenomenologically required, while for the $J/\psi$ meson only one ratio was enough to describe the data. Finally, we also observed a peculiar behavior of the mixed strong-electromagnetic amplitudes of the decays $\psi(2S)\to\Sigma^+ \overline \Sigma{}^-$ and $\psi(2S)\to\Sigma^- \overline \Sigma{}^+$.
[ { "created": "Fri, 22 May 2020 16:34:37 GMT", "version": "v1" } ]
2021-01-13
[ [ "Ferroli", "Rinaldo Baldini", "" ], [ "Mangoni", "Alessio", "" ], [ "Pacetti", "Simone", "" ], [ "Zhu", "Kai", "" ] ]
The strong, electromagnetic and mixed strong-electromagnetic amplitudes of the $\psi(2S)$ decays into baryon-anti-baryon pairs have been obtained by exploiting all available data sets in the framework of an effective Lagrangian model. We observed that at the $\psi(2S)$ mass the QCD regime is not completely perturbative, as can be inferred by the relative strength of the strong and the mixed strong-electromagnetic amplitudes. Recently a similar conclusion has been reached also for the $J/\psi$ decays. The relative phase between the strong and the electromagnetic amplitudes is $\varphi = (58\pm 8)^\circ$, to be compared with $\varphi = (73\pm 8)^\circ$ obtained for the $J/\psi$. On the other hand, in the case of the $\psi(2S)$ meson, different values of the ratio between strong and mixed strong-electromagnetic amplitudes are phenomenologically required, while for the $J/\psi$ meson only one ratio was enough to describe the data. Finally, we also observed a peculiar behavior of the mixed strong-electromagnetic amplitudes of the decays $\psi(2S)\to\Sigma^+ \overline \Sigma{}^-$ and $\psi(2S)\to\Sigma^- \overline \Sigma{}^+$.
hep-ph/9609258
Narison Stephan
Stephan Narison (LPM-Montpellier)
Heavy quarkonia mass-splittings in QCD: test of the $1/m$-expansion and estimates of $<\alpha_s G^2>$ and $\alpha_s$
Talk given at QCD 96-Montpellier, 4-12th July 1996 and at the 28th ICHEP96-Varsaw, 25-31th July 1996, and based on the paper hep-ph/9512348 (to appear in Phys. Lett.B386, October 1996). 9 pages in Latex files.
Nucl.Phys.Proc.Suppl. 54A (1997) 238-243
10.1016/S0920-5632(97)00047-9
Montpellier preprint PM 96/26
hep-ph hep-lat
null
I present a more refined analysis of the mass-splittings between the different heavy quarkonia states, using {\it new double ratios} of exponential moments of different two-point functions. Then, I test the validity of the $1/m$-expansion, extract $\alpha_s(M_Z)=0.127\pm 0.011$ from $M_{\chi_c(P^1_1)} - M_{\chi_c(P^3_1)}$, and provide a new estimate of the gluon condensate from $M_\psi -M_{\eta_c}$ and $M_{\chi_b}-M_\Upsilon$, which combined with the recent estimate from the $\tau$-like decay sum rules in $e^+e^-\rar I=1$ hadrons data, leads to the {\it update average value} $\la\alpha_s G^2\ra = (7.1\pm 0.9)\times 10^{-2}$ GeV$^4$ from the light and heavy quark systems. I also find $M_{\Upsilon}-M_{\eta_b}\approx 63^{-29}_{+51}$ MeV implying the possible observation of the $\eta_b$ in the $\Upsilon$-radiative decay.
[ { "created": "Thu, 5 Sep 1996 09:34:58 GMT", "version": "v1" } ]
2016-09-06
[ [ "Narison", "Stephan", "", "LPM-Montpellier" ] ]
I present a more refined analysis of the mass-splittings between the different heavy quarkonia states, using {\it new double ratios} of exponential moments of different two-point functions. Then, I test the validity of the $1/m$-expansion, extract $\alpha_s(M_Z)=0.127\pm 0.011$ from $M_{\chi_c(P^1_1)} - M_{\chi_c(P^3_1)}$, and provide a new estimate of the gluon condensate from $M_\psi -M_{\eta_c}$ and $M_{\chi_b}-M_\Upsilon$, which combined with the recent estimate from the $\tau$-like decay sum rules in $e^+e^-\rar I=1$ hadrons data, leads to the {\it update average value} $\la\alpha_s G^2\ra = (7.1\pm 0.9)\times 10^{-2}$ GeV$^4$ from the light and heavy quark systems. I also find $M_{\Upsilon}-M_{\eta_b}\approx 63^{-29}_{+51}$ MeV implying the possible observation of the $\eta_b$ in the $\Upsilon$-radiative decay.
0711.4820
Narendra Sahu
John McDonald, Narendra Sahu and Utpal Sarkar
Type-II Seesaw at Collider, Lepton Asymmetry and Singlet Scalar Dark Matter
8 pages, double column, references are added, minor change in title, section-III is revised, one figure is added, typos are corrected
JCAP 0804:037,2008
10.1088/1475-7516/2008/04/037
null
hep-ph astro-ph
null
We propose an extension of the standard model with a B-L global symmetry that is broken softly at the TeV scale. The neutrinos acquire masses through a type-II seesaw while the lepton (L) asymmetry arises in the {\it singlet sector} but without B-L violation. The model has the virtue that the scale of L-number violation ($\Lambda$) giving rise to neutrino masses is independent of the scale of leptogenesis ($\Lambda'$). As a result the model can explain {\it neutrino masses, singlet scalar dark matter and leptogenesis at the TeV scale}. The stability of the dark matter is ensured by a surviving $Z_2$ symmetry, which could be lifted at the Planck scale and thereby allowing Planck scale-suppressed decay of singlet scalar dark matter particles of mass $\approx 3$ MeV to $e^+ e^-$ pairs in the Galactic halo. The model also predicts a few hundred GeV doubly charged scalar and a long lived charged fermion, whose decay can be studied at Large Hadron Collider (LHC) and International Linear Collider (ILC).
[ { "created": "Thu, 29 Nov 2007 20:27:27 GMT", "version": "v1" }, { "created": "Fri, 7 Mar 2008 16:33:17 GMT", "version": "v2" } ]
2010-05-27
[ [ "McDonald", "John", "" ], [ "Sahu", "Narendra", "" ], [ "Sarkar", "Utpal", "" ] ]
We propose an extension of the standard model with a B-L global symmetry that is broken softly at the TeV scale. The neutrinos acquire masses through a type-II seesaw while the lepton (L) asymmetry arises in the {\it singlet sector} but without B-L violation. The model has the virtue that the scale of L-number violation ($\Lambda$) giving rise to neutrino masses is independent of the scale of leptogenesis ($\Lambda'$). As a result the model can explain {\it neutrino masses, singlet scalar dark matter and leptogenesis at the TeV scale}. The stability of the dark matter is ensured by a surviving $Z_2$ symmetry, which could be lifted at the Planck scale and thereby allowing Planck scale-suppressed decay of singlet scalar dark matter particles of mass $\approx 3$ MeV to $e^+ e^-$ pairs in the Galactic halo. The model also predicts a few hundred GeV doubly charged scalar and a long lived charged fermion, whose decay can be studied at Large Hadron Collider (LHC) and International Linear Collider (ILC).
0907.4012
Jorge Casalderrey-Solana
Jorge Casalderrey-Solana
A Photon Peak due to Strong Coupling
4 pages, 2 figures - To appear in the conference proceedings for Quark Matter 2009, March 30 - April 4, Knoxville, Tennessee. V2: minor corrections
Nucl.Phys.A830:215c-218c,2009
10.1016/j.nuclphysa.2009.10.016
CERN-PH-TH/2009-134
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that if a flavour-less vector meson remains bound after deconfinement, and if its limiting velocity in the quark-gluon plasma is subluminal, then this meson produces a distinct peak in the spectrum of thermal photons emitted by the plasma. We also demonstrate that this effect is a universal property of all strongly coupled, large-$\nc$ plasmas with a gravity dual. For the $J/\Psi$ the corresponding peak lies between 3 and 5 GeV and could be observed at the LHC.
[ { "created": "Thu, 23 Jul 2009 09:16:57 GMT", "version": "v1" }, { "created": "Sun, 20 Sep 2009 14:19:16 GMT", "version": "v2" } ]
2009-11-18
[ [ "Casalderrey-Solana", "Jorge", "" ] ]
We show that if a flavour-less vector meson remains bound after deconfinement, and if its limiting velocity in the quark-gluon plasma is subluminal, then this meson produces a distinct peak in the spectrum of thermal photons emitted by the plasma. We also demonstrate that this effect is a universal property of all strongly coupled, large-$\nc$ plasmas with a gravity dual. For the $J/\Psi$ the corresponding peak lies between 3 and 5 GeV and could be observed at the LHC.
1710.09644
Marcella Bona
Cristiano Alpigiani, Adrian Bevan, Marcella Bona, Marco Ciuchini, Denis Derkach, Enrico Franco, Vittorio Lubicz, Guido Martinelli, Fabrizio Parodi, Maurizio Pierini, Luca Silvestrini, Viola Sordini, Achille Stocchi, Cecilia Tarantino, and Vincenzo Vagnoni
Unitarity Triangle Analysis in the Standard Model and Beyond
6 pages, 13 figures, Proceedings for The Fifth Annual Conference on Large Hadron Collider Physics (LHCP 2017), 2017
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Flavour physics represents a unique test bench for the Standard Model (SM). New analyses performed at the LHC experiments are now providing unprecedented insights into CKM metrology and new evidences for rare decays. The CKM picture can provide very precise SM predictions through global analyses. We present here the results of the latest global SM analysis performed by the UTfit collaboration including all the most updated inputs from experiments, lattice QCD and phenomenological calculations. In addition, the Unitarity Triangle (UT) analysis can be used to constrain the parameter space in possible new physics (NP) scenarios. We update here also the UT analysis beyond the SM by the UTfit collaboration. All of the available experimental and theoretical information on $\Delta F=2$ processes is reinterpreted including a model-independent NP parametrisation. We determine the allowed NP contributions in the kaon, $D$, $B_d$, and $B_s$ sectors and, in various NP scenarios, we translate them into bounds for the NP scale as a function of NP couplings.
[ { "created": "Thu, 26 Oct 2017 11:21:12 GMT", "version": "v1" }, { "created": "Fri, 27 Oct 2017 08:18:27 GMT", "version": "v2" } ]
2017-10-30
[ [ "Alpigiani", "Cristiano", "" ], [ "Bevan", "Adrian", "" ], [ "Bona", "Marcella", "" ], [ "Ciuchini", "Marco", "" ], [ "Derkach", "Denis", "" ], [ "Franco", "Enrico", "" ], [ "Lubicz", "Vittorio", "" ], ...
Flavour physics represents a unique test bench for the Standard Model (SM). New analyses performed at the LHC experiments are now providing unprecedented insights into CKM metrology and new evidences for rare decays. The CKM picture can provide very precise SM predictions through global analyses. We present here the results of the latest global SM analysis performed by the UTfit collaboration including all the most updated inputs from experiments, lattice QCD and phenomenological calculations. In addition, the Unitarity Triangle (UT) analysis can be used to constrain the parameter space in possible new physics (NP) scenarios. We update here also the UT analysis beyond the SM by the UTfit collaboration. All of the available experimental and theoretical information on $\Delta F=2$ processes is reinterpreted including a model-independent NP parametrisation. We determine the allowed NP contributions in the kaon, $D$, $B_d$, and $B_s$ sectors and, in various NP scenarios, we translate them into bounds for the NP scale as a function of NP couplings.
2210.07221
Siavash Neshatpour
T. Hurth, F. Mahmoudi, D. Martinez Santos, S. Neshatpour
Neutral current B-decay anomalies
12 pages, 4 figures. Based on talks given by S.N. at FPCapri2022 and by F.M. at FCCP2022
null
null
CERN-TH-2022-166, MITP-22-081
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the implications of $b \to s \ell^+\ell^-$ measurements and their deviations with respect to the Standard Model predictions in a model-independent framework. We highlight in particular the impact of the recent updated measurements including the updated $B_s \to \phi \mu^+\mu^-$ branching ratios and angular observables, the recent CMS measurement of the branching ratio of $B_s\to\mu^+ \mu^-$, and the LHCb measured lepton flavour universality violating ratios $R_{K_S^0}$ and $R_{K^{*+}}$. In addition, we check the compatibility of the new physics effect for the theoretically clean observables with the rest of the neutral $B$ decays observables.
[ { "created": "Thu, 13 Oct 2022 17:47:34 GMT", "version": "v1" } ]
2022-10-14
[ [ "Hurth", "T.", "" ], [ "Mahmoudi", "F.", "" ], [ "Santos", "D. Martinez", "" ], [ "Neshatpour", "S.", "" ] ]
We discuss the implications of $b \to s \ell^+\ell^-$ measurements and their deviations with respect to the Standard Model predictions in a model-independent framework. We highlight in particular the impact of the recent updated measurements including the updated $B_s \to \phi \mu^+\mu^-$ branching ratios and angular observables, the recent CMS measurement of the branching ratio of $B_s\to\mu^+ \mu^-$, and the LHCb measured lepton flavour universality violating ratios $R_{K_S^0}$ and $R_{K^{*+}}$. In addition, we check the compatibility of the new physics effect for the theoretically clean observables with the rest of the neutral $B$ decays observables.
1602.03939
Xinjian Wen
Chang-Feng Li, Li Yang, Xin-Jian Wen, and Guang-Xiong Peng
Magnetized quark matter with a magnetic-field dependent coupling
10 pages, 8 figures, updated to PRD published version
null
10.1103/PhysRevD.93.054005
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It was recently derived that the QCD running coupling is a function of the magnetic field strength under the strong magnetic field approximation. Inspired by this progress and based on the self-consistent solutions of gap equations, the properties of two-flavor and three-flavor quark matter are studied in the framework of the Nambu-Jona-Lasinio model with a magnetic-field dependent running coupling. We find that the dynamical quark masses as functions of the magnetic field strength are not monotonous in the fully chirally broken phase. Furthermore, the stability of magnetized quark matter with the running coupling is enhanced by lowering the free energy per baryon, which is expected to be more stable than that of the conventional constant coupling case. It is concluded that the magnetized strange quark matter described by running coupling can be absolutely stable.
[ { "created": "Fri, 12 Feb 2016 01:05:13 GMT", "version": "v1" }, { "created": "Sat, 27 Feb 2016 08:22:27 GMT", "version": "v2" } ]
2016-03-23
[ [ "Li", "Chang-Feng", "" ], [ "Yang", "Li", "" ], [ "Wen", "Xin-Jian", "" ], [ "Peng", "Guang-Xiong", "" ] ]
It was recently derived that the QCD running coupling is a function of the magnetic field strength under the strong magnetic field approximation. Inspired by this progress and based on the self-consistent solutions of gap equations, the properties of two-flavor and three-flavor quark matter are studied in the framework of the Nambu-Jona-Lasinio model with a magnetic-field dependent running coupling. We find that the dynamical quark masses as functions of the magnetic field strength are not monotonous in the fully chirally broken phase. Furthermore, the stability of magnetized quark matter with the running coupling is enhanced by lowering the free energy per baryon, which is expected to be more stable than that of the conventional constant coupling case. It is concluded that the magnetized strange quark matter described by running coupling can be absolutely stable.
hep-ph/0308276
Tomohiro Endoh
T. Endoh, T. Morozumi, Z. Xiong
Primordial Lepton Family Asymmtries in Seesaw Model
26 pages, 8 figures, ptp.style
Prog.Theor.Phys. 111 (2004) 123-149
10.1143/PTP.111.123
null
hep-ph
null
In leptogenesis scenario, the decays of heavy Majorana neutrinos generate lepton family asymmetries, $Y_e, Y_{\mu}$ and $Y_{\tau}$. They are sensitive to CP violating phases in seesaw models. The time evolution of the lepton family asymmetries are derived by solving Boltzmann equations. By taking a minimal seesaw model, we show how each family asymmetry varies with a CP violating phase. For instance, we find the case that the lepton asymmetry is dominated by $Y_{\mu}$ or $Y_{\tau}$ depending on the choice of the CP violating phase. We also find the case that the signs of lepton family asymmetries $Y_{\mu}$ and $Y_{\tau}$ are opposite each other. Their absolute values can be larger than the total lepton asymmetry and the baryon asymmetry may result from the cancellation of the lepton family asymmetries.
[ { "created": "Wed, 27 Aug 2003 12:53:47 GMT", "version": "v1" } ]
2009-11-10
[ [ "Endoh", "T.", "" ], [ "Morozumi", "T.", "" ], [ "Xiong", "Z.", "" ] ]
In leptogenesis scenario, the decays of heavy Majorana neutrinos generate lepton family asymmetries, $Y_e, Y_{\mu}$ and $Y_{\tau}$. They are sensitive to CP violating phases in seesaw models. The time evolution of the lepton family asymmetries are derived by solving Boltzmann equations. By taking a minimal seesaw model, we show how each family asymmetry varies with a CP violating phase. For instance, we find the case that the lepton asymmetry is dominated by $Y_{\mu}$ or $Y_{\tau}$ depending on the choice of the CP violating phase. We also find the case that the signs of lepton family asymmetries $Y_{\mu}$ and $Y_{\tau}$ are opposite each other. Their absolute values can be larger than the total lepton asymmetry and the baryon asymmetry may result from the cancellation of the lepton family asymmetries.
hep-ph/0609100
Christopher Tevlin
Michael H. Seymour, Christopher Tevlin
A Comparison of two different jet algorithms for the top mass reconstruction at the LHC
21 pages, 16 figures, accepted by JHEP
JHEP0611:052,2006
10.1088/1126-6708/2006/11/052
MAN/HEP/2006/16
hep-ph
null
We compare the abilities of the cluster-type jet algorithm, KtJet, and a mid-point iterating cone algorithm to reconstruct the top mass at the LHC. We discuss the information contained in the merging scales of cluster-type algorithms, and how this can be used in experimental analyses, as well as the different sources of systematic errors for the two algorithms. We find that the sources of systematic error are different for the two algorithms, which may help to better constrain the systematic error on the top mass at the LHC.
[ { "created": "Mon, 11 Sep 2006 17:02:40 GMT", "version": "v1" }, { "created": "Thu, 19 Oct 2006 17:34:17 GMT", "version": "v2" } ]
2009-11-11
[ [ "Seymour", "Michael H.", "" ], [ "Tevlin", "Christopher", "" ] ]
We compare the abilities of the cluster-type jet algorithm, KtJet, and a mid-point iterating cone algorithm to reconstruct the top mass at the LHC. We discuss the information contained in the merging scales of cluster-type algorithms, and how this can be used in experimental analyses, as well as the different sources of systematic errors for the two algorithms. We find that the sources of systematic error are different for the two algorithms, which may help to better constrain the systematic error on the top mass at the LHC.
0802.3431
Toshifumi Yamashita
Naoyuki Haba, Shigeki Matsumoto, Nobuchika Okada, Toshifumi Yamashita
Effective Potential of Higgs Field in Warped Gauge-Higgs Unification
28 pages, 6 figures
Prog.Theor.Phys.120:77-98,2008
10.1143/PTP.120.77
OU-HET 600/2008, KEK-TH-1190, SISSA 69/2007/EP
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The gauge-Higgs unification is one of influential scenarios to solve the hierarchy problem in the Standard Model. Recently, the scenario on the warped background attracts many attentions due to a large possibility to construct a realistic model naturally in this framework. It is, however, well known that the effective potential for the Higgs field, which is the most important prediction of the scenario, is not easy to calculate on the warped background, because masses of Kaluza-Klein particles are not obtained analytically. In this article, we derive useful formulae for the effective potential. The formulae allow us to calculate the Higgs mass easily, thus to construct a realistic model in the gauge-Higgs unification scenario on the warped background. Using obtained formulae, we calculate contributions from bulk fermions with several boundary conditions. We also show bulk fermions, which have boundary conditions not allowed in the orbifold picture, do not contribute to the effective potential.
[ { "created": "Mon, 25 Feb 2008 09:01:00 GMT", "version": "v1" } ]
2008-11-26
[ [ "Haba", "Naoyuki", "" ], [ "Matsumoto", "Shigeki", "" ], [ "Okada", "Nobuchika", "" ], [ "Yamashita", "Toshifumi", "" ] ]
The gauge-Higgs unification is one of influential scenarios to solve the hierarchy problem in the Standard Model. Recently, the scenario on the warped background attracts many attentions due to a large possibility to construct a realistic model naturally in this framework. It is, however, well known that the effective potential for the Higgs field, which is the most important prediction of the scenario, is not easy to calculate on the warped background, because masses of Kaluza-Klein particles are not obtained analytically. In this article, we derive useful formulae for the effective potential. The formulae allow us to calculate the Higgs mass easily, thus to construct a realistic model in the gauge-Higgs unification scenario on the warped background. Using obtained formulae, we calculate contributions from bulk fermions with several boundary conditions. We also show bulk fermions, which have boundary conditions not allowed in the orbifold picture, do not contribute to the effective potential.
hep-ph/0511066
Junegone Chay
Junegone Chay, Chul Kim
Deep inelastic scattering near the endpoint in soft-collinear effective theory
40 pages, 12 figures. Two major changes: (1) The zero-bin subtraction is included in the radiative corrections for the collinear part. (2) The parton distribution function near the endpoint region is considered including the soft part. Figures and references are added accordingly
Phys.Rev.D75:016003,2007
10.1103/PhysRevD.75.016003
null
hep-ph
null
We apply the soft-collinear effective theory (SCET) to deep inelastic scattering near the endpoint region. The forward scattering amplitude, and the structure functions are shown to factorize as a convolution of the Wilson coefficients, the jet functions, the parton distribution functions. The behavior of the parton distribution functions near the endpoint region is considered. It turns out that it evolves with the Altarelli-Parisi kernel even in the endpoint region, and the parton distribution function can be factorized further into a collinear part and the soft Wilson line. The factorized form for the structure functions is obtained by the two-step matching, and the radiative corrections or the evolution for each factorized part can be computed in perturbation theory. We present the radiative corrections of each factorized part to leading order in alpha_s, including the zero-bin subtraction for the collinear part.
[ { "created": "Mon, 7 Nov 2005 04:21:38 GMT", "version": "v1" }, { "created": "Thu, 16 Nov 2006 09:36:26 GMT", "version": "v2" } ]
2008-11-26
[ [ "Chay", "Junegone", "" ], [ "Kim", "Chul", "" ] ]
We apply the soft-collinear effective theory (SCET) to deep inelastic scattering near the endpoint region. The forward scattering amplitude, and the structure functions are shown to factorize as a convolution of the Wilson coefficients, the jet functions, the parton distribution functions. The behavior of the parton distribution functions near the endpoint region is considered. It turns out that it evolves with the Altarelli-Parisi kernel even in the endpoint region, and the parton distribution function can be factorized further into a collinear part and the soft Wilson line. The factorized form for the structure functions is obtained by the two-step matching, and the radiative corrections or the evolution for each factorized part can be computed in perturbation theory. We present the radiative corrections of each factorized part to leading order in alpha_s, including the zero-bin subtraction for the collinear part.
hep-ph/9407230
V. Morgunov
B.V.Geshkenbein, V.L.Morgunov
The magnitude of the gluon condensate and the masses of $c$ and $b$ quarks from the families of ${\cal J}$/$\Psi$ and $\Upsilon$ mesons
in LaTeX, 12 pages, 3 figures available upon request, SSCL - preprint - 534, (1993)
Phys.Atom.Nucl.58:1771-1777,1995; Yad.Fiz.58:1873-1879,1995
null
null
hep-ph
null
It is shown that the model used in [1] for the description of the experimental function $R_c (s)$ in the form of a sum of $\delta$-functions and the plateau contradicts the Wilson operator expansion (O.E.) in the terms due to the gluon condensate. A QCD model with an infinite number of vector mesons [12,13] does satisfy the requirements of the O.E. for masses and electronic widths resonances close to the experimental values. The region of allowable values of the masses of $c$ and $b$-quarks and the gluon condensate compatible with the O.E. is obtained (Figs. 2,3).
[ { "created": "Tue, 5 Jul 1994 17:48:00 GMT", "version": "v1" } ]
2011-03-17
[ [ "Geshkenbein", "B. V.", "" ], [ "Morgunov", "V. L.", "" ] ]
It is shown that the model used in [1] for the description of the experimental function $R_c (s)$ in the form of a sum of $\delta$-functions and the plateau contradicts the Wilson operator expansion (O.E.) in the terms due to the gluon condensate. A QCD model with an infinite number of vector mesons [12,13] does satisfy the requirements of the O.E. for masses and electronic widths resonances close to the experimental values. The region of allowable values of the masses of $c$ and $b$-quarks and the gluon condensate compatible with the O.E. is obtained (Figs. 2,3).
1610.10084
Emanuele Angelo Bagnaschi
E. Bagnaschi, J.C. Costa, K. Sakurai, M. Borsato, O. Buchmueller, R. Cavanaugh, V. Chobanova, M. Citron, A. De Roeck, M.J. Dolan, J.R. Ellis, H. Fl\"acher, S. Heinemeyer, G. Isidori, M. Lucio, D. Mart\'inez Santos, K.A. Olive, A. Richards, K.J. de Vries and G. Weiglein
Likelihood Analysis of Supersymmetric SU(5) GUTs
38 pages, 22 figures, version published on EPJC
Eur.Phys.J. C77 (2017) no.2, 104
10.1140/epjc/s10052-017-4639-6
KCL-PH-TH/2016-57, CERN-PH-TH/2016-217, DESY 16-156, IFT-UAM/CSIC-16-105, FTPI-MINN-16/29, UMN-TH-3609/16, FERMILAB-PUB-16-453-CMS, IPPP/16/97
hep-ph astro-ph.HE hep-ex
http://creativecommons.org/licenses/by/4.0/
We perform a likelihood analysis of the constraints from accelerator experiments and astrophysical observations on supersymmetric (SUSY) models with SU(5) boundary conditions on soft SUSY-breaking parameters at the GUT scale. The parameter space of the models studied has 7 parameters: a universal gaugino mass $m_{1/2}$, distinct masses for the scalar partners of matter fermions in five- and ten-dimensional representations of SU(5), $m_5$ and $m_{10}$, and for the $\mathbf{5}$ and $\mathbf{\bar 5}$ Higgs representations $m_{H_u}$ and $m_{H_d}$, a universal trilinear soft SUSY-breaking parameter $A_0$, and the ratio of Higgs vevs $\tan \beta$. In addition to previous constraints from direct sparticle searches, low-energy and flavour observables, we incorporate constraints based on preliminary results from 13 TeV LHC searches for jets + MET events and long-lived particles, as well as the latest PandaX-II and LUX searches for direct Dark Matter detection. In addition to previously-identified mechanisms for bringing the supersymmetric relic density into the range allowed by cosmology, we identify a novel ${\tilde u_R}/{\tilde c_R} - \tilde{\chi}^0_1$ coannihilation mechanism that appears in the supersymmetric SU(5) GUT model and discuss the role of ${\tilde \nu_\tau}$ coannihilation. We find complementarity between the prospects for direct Dark Matter detection and SUSY searches at the LHC.
[ { "created": "Mon, 31 Oct 2016 19:38:47 GMT", "version": "v1" }, { "created": "Wed, 16 Nov 2016 17:59:24 GMT", "version": "v2" }, { "created": "Wed, 26 Apr 2017 12:01:17 GMT", "version": "v3" } ]
2017-04-27
[ [ "Bagnaschi", "E.", "" ], [ "Costa", "J. C.", "" ], [ "Sakurai", "K.", "" ], [ "Borsato", "M.", "" ], [ "Buchmueller", "O.", "" ], [ "Cavanaugh", "R.", "" ], [ "Chobanova", "V.", "" ], [ "Citron", ...
We perform a likelihood analysis of the constraints from accelerator experiments and astrophysical observations on supersymmetric (SUSY) models with SU(5) boundary conditions on soft SUSY-breaking parameters at the GUT scale. The parameter space of the models studied has 7 parameters: a universal gaugino mass $m_{1/2}$, distinct masses for the scalar partners of matter fermions in five- and ten-dimensional representations of SU(5), $m_5$ and $m_{10}$, and for the $\mathbf{5}$ and $\mathbf{\bar 5}$ Higgs representations $m_{H_u}$ and $m_{H_d}$, a universal trilinear soft SUSY-breaking parameter $A_0$, and the ratio of Higgs vevs $\tan \beta$. In addition to previous constraints from direct sparticle searches, low-energy and flavour observables, we incorporate constraints based on preliminary results from 13 TeV LHC searches for jets + MET events and long-lived particles, as well as the latest PandaX-II and LUX searches for direct Dark Matter detection. In addition to previously-identified mechanisms for bringing the supersymmetric relic density into the range allowed by cosmology, we identify a novel ${\tilde u_R}/{\tilde c_R} - \tilde{\chi}^0_1$ coannihilation mechanism that appears in the supersymmetric SU(5) GUT model and discuss the role of ${\tilde \nu_\tau}$ coannihilation. We find complementarity between the prospects for direct Dark Matter detection and SUSY searches at the LHC.
hep-ph/0612122
Stefano Actis
S. Actis, A. Ferroglia, G. Passarino and M. Passera
Two-Loop Renormalization in the Standard Model Part I: Prolegomena
38 pages, LaTeX
Nucl.Phys.B777:1-34,2007
10.1016/j.nuclphysb.2007.04.021
ZU-TH 23/06; DESY 06-223; SFB/CPP-06-54
hep-ph
null
In this paper the building blocks for the two-loop renormalization of the Standard Model are introduced with a comprehensive discussion of the special vertices induced in the Lagrangian by a particular diagonalization of the neutral sector and by two alternative treatments of the Higgs tadpoles. Dyson resummed propagators for the gauge bosons are derived, and two-loop Ward-Slavnov-Taylor identities are discussed. In part II, the complete set of counterterms needed for the two-loop renormalization will be derived. In part III, a renormalization scheme will be introduced, connecting the renormalized quantities to an input parameter set of (pseudo-)experimental data, critically discussing renormalization of a gauge theory with unstable particles.
[ { "created": "Mon, 11 Dec 2006 12:21:57 GMT", "version": "v1" } ]
2008-11-26
[ [ "Actis", "S.", "" ], [ "Ferroglia", "A.", "" ], [ "Passarino", "G.", "" ], [ "Passera", "M.", "" ] ]
In this paper the building blocks for the two-loop renormalization of the Standard Model are introduced with a comprehensive discussion of the special vertices induced in the Lagrangian by a particular diagonalization of the neutral sector and by two alternative treatments of the Higgs tadpoles. Dyson resummed propagators for the gauge bosons are derived, and two-loop Ward-Slavnov-Taylor identities are discussed. In part II, the complete set of counterterms needed for the two-loop renormalization will be derived. In part III, a renormalization scheme will be introduced, connecting the renormalized quantities to an input parameter set of (pseudo-)experimental data, critically discussing renormalization of a gauge theory with unstable particles.
1508.03073
Kirill Boguslavski
J. Berges, K. Boguslavski, S. Schlichting and R. Venugopalan
Nonequilibrium fixed points in longitudinally expanding scalar theories: infrared cascade, Bose condensation and a challenge for kinetic theory
24 pages, 18 figures; v2 - PRD in press (minor changes)
Phys. Rev. D 92, 096006 (2015)
10.1103/PhysRevD.92.096006
INT-PUB-15-043
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In Phys. Rev. Lett. 114 (2015) 6, 061601, we reported on a new universality class for longitudinally expanding systems, encompassing strongly correlated non-Abelian plasmas and $N$-component self-interacting scalar field theories. Using classical-statistical methods, we showed that these systems share the same self-similar scaling properties for a wide range of momenta in a limit where particles are weakly coupled but their occupancy is high. Here we significantly expand on our previous work and delineate two further self-similar regimes. One of these occurs in the deep infrared (IR) regime of very high occupancies, where the nonequilibrium dynamics leads to the formation of a Bose-Einstein Condensate. The universal IR scaling exponents and the spectral index characterizing the isotropic IR distributions are described by an effective theory derived from a systematic large-$N$ expansion at next-to-leading order. Remarkably, this effective theory can be cast as a vertex-resummed kinetic theory. The other novel self-similar regime occurs close to the hard physical scale of the theory, and sets in only at later times. We argue that the important role of the infrared dynamics ensures that key features of our results for scalar and gauge theories cannot be reproduced consistently in conventional kinetic theory frameworks.
[ { "created": "Wed, 12 Aug 2015 21:38:24 GMT", "version": "v1" }, { "created": "Tue, 20 Oct 2015 10:46:46 GMT", "version": "v2" } ]
2015-11-11
[ [ "Berges", "J.", "" ], [ "Boguslavski", "K.", "" ], [ "Schlichting", "S.", "" ], [ "Venugopalan", "R.", "" ] ]
In Phys. Rev. Lett. 114 (2015) 6, 061601, we reported on a new universality class for longitudinally expanding systems, encompassing strongly correlated non-Abelian plasmas and $N$-component self-interacting scalar field theories. Using classical-statistical methods, we showed that these systems share the same self-similar scaling properties for a wide range of momenta in a limit where particles are weakly coupled but their occupancy is high. Here we significantly expand on our previous work and delineate two further self-similar regimes. One of these occurs in the deep infrared (IR) regime of very high occupancies, where the nonequilibrium dynamics leads to the formation of a Bose-Einstein Condensate. The universal IR scaling exponents and the spectral index characterizing the isotropic IR distributions are described by an effective theory derived from a systematic large-$N$ expansion at next-to-leading order. Remarkably, this effective theory can be cast as a vertex-resummed kinetic theory. The other novel self-similar regime occurs close to the hard physical scale of the theory, and sets in only at later times. We argue that the important role of the infrared dynamics ensures that key features of our results for scalar and gauge theories cannot be reproduced consistently in conventional kinetic theory frameworks.
hep-ph/0305228
Wenyu Wang
Y.L. Wu, Y.A. Yan, M. Zhong, Y.B. Zuo, W.Y. Wang
HQEFT as A Large Component QCD and Comments on The Incompleteness of HQET
11 pages, revtex, published version
Mod.Phys.Lett. A18 (2003) 1303-1316
10.1142/S0217732303011149
null
hep-ph
null
The Heavy quark effective field theory (HQEFT) is revisited in a more intuitive way. It is shown that HQEFT is a consistent large component QCD of heavy quarks. In the non-relativistic limit, HQEFT recovers the non-relativistic QCD (NRQCD). The resulting new effects in the HQEFT of QCD are carefully reexamined. It is then natural to come to the comments on the usual heavy quark effective theory (HQET). Consistent phenomenological applications of HQEFT exhibit its interesting features and completeness in comparison with HQET. It then becomes manifest why we shall base on the HQEFT of QCD rather than HQET which is an incomplete one for computing 1/m_Q corrections. More precise extraction for |V_{cb}| and |V_{ub}| in the HQEFT of QCD is emphasized.
[ { "created": "Wed, 21 May 2003 07:53:54 GMT", "version": "v1" } ]
2016-09-06
[ [ "Wu", "Y. L.", "" ], [ "Yan", "Y. A.", "" ], [ "Zhong", "M.", "" ], [ "Zuo", "Y. B.", "" ], [ "Wang", "W. Y.", "" ] ]
The Heavy quark effective field theory (HQEFT) is revisited in a more intuitive way. It is shown that HQEFT is a consistent large component QCD of heavy quarks. In the non-relativistic limit, HQEFT recovers the non-relativistic QCD (NRQCD). The resulting new effects in the HQEFT of QCD are carefully reexamined. It is then natural to come to the comments on the usual heavy quark effective theory (HQET). Consistent phenomenological applications of HQEFT exhibit its interesting features and completeness in comparison with HQET. It then becomes manifest why we shall base on the HQEFT of QCD rather than HQET which is an incomplete one for computing 1/m_Q corrections. More precise extraction for |V_{cb}| and |V_{ub}| in the HQEFT of QCD is emphasized.
1206.4779
D. V. Ahluwalia
D. V. Ahluwalia
CP violating Tri-bimaximal-Cabibbo mixing
6 pages
ISRN High Energy Physics 2012 (2012) 954272
10.5402/2012/954272
null
hep-ph hep-ex nucl-th
http://creativecommons.org/licenses/by/3.0/
In view of the new data from the Daya Bay and RENO collaborations, King has presented a very natural deformation of tri-bimaximal mixing. Here we show that L/E flatness of the e-like event ratio in the atmospheric neutrino data, when coupled with King's observation that the smallest neutrino mixing angle, \theta_{13}, seems to be related to the largest quark mixing angle (the Cabibbo angle \theta_C), leads to a CP violating tri-bimaximal-Cabibbo mixing. King's tri-bimaximal-Cabibbo mixing follows as a leading order approximation from our result.
[ { "created": "Thu, 21 Jun 2012 05:42:50 GMT", "version": "v1" } ]
2012-10-08
[ [ "Ahluwalia", "D. V.", "" ] ]
In view of the new data from the Daya Bay and RENO collaborations, King has presented a very natural deformation of tri-bimaximal mixing. Here we show that L/E flatness of the e-like event ratio in the atmospheric neutrino data, when coupled with King's observation that the smallest neutrino mixing angle, \theta_{13}, seems to be related to the largest quark mixing angle (the Cabibbo angle \theta_C), leads to a CP violating tri-bimaximal-Cabibbo mixing. King's tri-bimaximal-Cabibbo mixing follows as a leading order approximation from our result.
hep-ph/0605221
Manuel Valverde
J. Nieves, M. Valverde and M.J. Vicente Vacas
Charged and Neutral Current Neutrino Induced Nucleon Emission Reactions
5 pages, 4 figures. Contribution to 20th Max Born Symposium, Wroclaw Poland), December 7-10, 2005
Acta Phys.Polon.B37:2295,2006
null
null
hep-ph
null
By means of a Monte Carlo cascade method, to account for the rescattering of the outgoing nucleon, we study the charged and neutral current inclusive one nucleon knockout reactions off nuclei induced by neutrinos. The nucleon emission process studied here is a clear signal for neutral--current neutrino driven reactions, and can be used in the analysis of future neutrino experiments.
[ { "created": "Sat, 20 May 2006 14:42:34 GMT", "version": "v1" } ]
2011-03-17
[ [ "Nieves", "J.", "" ], [ "Valverde", "M.", "" ], [ "Vacas", "M. J. Vicente", "" ] ]
By means of a Monte Carlo cascade method, to account for the rescattering of the outgoing nucleon, we study the charged and neutral current inclusive one nucleon knockout reactions off nuclei induced by neutrinos. The nucleon emission process studied here is a clear signal for neutral--current neutrino driven reactions, and can be used in the analysis of future neutrino experiments.
1702.00797
Riccardo Torre
Roberto Contino, Davide Greco, Rakhi Mahbubani, Riccardo Rattazzi and Riccardo Torre
Precision Tests and Fine Tuning in Twin Higgs Models
50 pages (29 + appendices), 9 figures; v2: the section and appendix on the Higgs potential have been updated, the results are unchanged
Phys. Rev. D 96, 095036 (2017)
10.1103/PhysRevD.96.095036
CERN-TH-2017-026
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the parametric structure of Twin Higgs (TH) theories and assess the gain in fine tuning which they enable compared to extensions of the Standard Model with colored top partners. Estimates show that, at least in the simplest realizations of the TH idea, the separation between the mass of new colored particles and the electroweak scale is controlled by the coupling strength of the underlying UV theory, and that a parametric gain is achieved only for strongly-coupled dynamics. Motivated by this consideration we focus on one of these simple realizations, namely composite TH theories, and study how well such constructions can reproduce electroweak precision data. The most important effect of the Twin states is found to be the infrared contribution to the Higgs quartic coupling, while direct corrections to electroweak observables are sub-leading and negligible. We perform a careful fit to the electroweak data including the leading-logarithmic corrections to the Higgs quartic up to three loops. Our analysis shows that agreement with electroweak precision tests can be achieved with only a moderate amount of tuning, in the range 5-10\%, in theories where colored states have mass of order 3-5 TeV and are thus out of reach of the LHC. For these levels of tuning, larger masses are excluded by a perturbativity bound, which makes these theories possibly discoverable, hence falsifiable, only at a future 100 TeV collider.
[ { "created": "Thu, 2 Feb 2017 19:03:43 GMT", "version": "v1" }, { "created": "Mon, 26 Feb 2018 07:58:18 GMT", "version": "v2" } ]
2018-02-27
[ [ "Contino", "Roberto", "" ], [ "Greco", "Davide", "" ], [ "Mahbubani", "Rakhi", "" ], [ "Rattazzi", "Riccardo", "" ], [ "Torre", "Riccardo", "" ] ]
We analyze the parametric structure of Twin Higgs (TH) theories and assess the gain in fine tuning which they enable compared to extensions of the Standard Model with colored top partners. Estimates show that, at least in the simplest realizations of the TH idea, the separation between the mass of new colored particles and the electroweak scale is controlled by the coupling strength of the underlying UV theory, and that a parametric gain is achieved only for strongly-coupled dynamics. Motivated by this consideration we focus on one of these simple realizations, namely composite TH theories, and study how well such constructions can reproduce electroweak precision data. The most important effect of the Twin states is found to be the infrared contribution to the Higgs quartic coupling, while direct corrections to electroweak observables are sub-leading and negligible. We perform a careful fit to the electroweak data including the leading-logarithmic corrections to the Higgs quartic up to three loops. Our analysis shows that agreement with electroweak precision tests can be achieved with only a moderate amount of tuning, in the range 5-10\%, in theories where colored states have mass of order 3-5 TeV and are thus out of reach of the LHC. For these levels of tuning, larger masses are excluded by a perturbativity bound, which makes these theories possibly discoverable, hence falsifiable, only at a future 100 TeV collider.
hep-ph/0108177
Smirnov Alexei
P. I. Krastev and A. Yu. Smirnov
Global Analysis with SNO: Toward the Solution of the Solar Neutrino Problem
35 pages, latex, 9 figures; results of analysis slightly changed due to different treatment of the hep neutrino flux; predictions for NC/CC ratio and Borexino rate added
Phys.Rev. D65 (2002) 073022
10.1103/PhysRevD.65.073022
null
hep-ph hep-ex
null
We perform a global analysis of the latest solar neutrino data including the SNO result on the CC-event rate. This result further favors the LMA solution of the solar neutrino problem. The best fit values of parameters we find are: \Delta m^2 = (4.8 - 5.0)10^{-5} eV^2, tan^2 \theta = 0.35 - 0.38, f_B = 1.08 - 1.12, and f_{hep} = 1 - 4. With respect to this best fit the LOW solution is accepted at 90% C.L.. The Vacuum oscillation solution with \Delta m^2 = 1.4 10^{-10} eV^2, gives good fit of the data provided that the boron neutrino flux is substantially smaller than the SSM flux (f_B \sim 0.5). The SMA solution is accepted only at 3\sigma level. We find that vacuum oscillations to sterile neutrino, VAC(sterile), with f_B \sim 0.5 also give rather good global fit of the data. All other sterile solutions are strongly disfavored. We check the quality of the fit by constructing the pull-off diagrams of observables. Predictions for the day-night asymmetry, spectrum distortion and NC/CC ratio at SNO are calculated. In the best fit points of the global solutions we find: A_{DN}^{CC} \approx (7 - 8)% for LMA, \sim 3% for LOW, and (2 - 3)% for SMA. It will be difficult to see the distortion of the spectrum expected for LMA as well as LOW solutions. However, future SNO spectral data can significantly affect the VAC and SMA solutions. We also calculate expectations for the BOREXINO rate.
[ { "created": "Wed, 22 Aug 2001 16:30:11 GMT", "version": "v1" }, { "created": "Fri, 9 Nov 2001 18:03:17 GMT", "version": "v2" } ]
2009-11-07
[ [ "Krastev", "P. I.", "" ], [ "Smirnov", "A. Yu.", "" ] ]
We perform a global analysis of the latest solar neutrino data including the SNO result on the CC-event rate. This result further favors the LMA solution of the solar neutrino problem. The best fit values of parameters we find are: \Delta m^2 = (4.8 - 5.0)10^{-5} eV^2, tan^2 \theta = 0.35 - 0.38, f_B = 1.08 - 1.12, and f_{hep} = 1 - 4. With respect to this best fit the LOW solution is accepted at 90% C.L.. The Vacuum oscillation solution with \Delta m^2 = 1.4 10^{-10} eV^2, gives good fit of the data provided that the boron neutrino flux is substantially smaller than the SSM flux (f_B \sim 0.5). The SMA solution is accepted only at 3\sigma level. We find that vacuum oscillations to sterile neutrino, VAC(sterile), with f_B \sim 0.5 also give rather good global fit of the data. All other sterile solutions are strongly disfavored. We check the quality of the fit by constructing the pull-off diagrams of observables. Predictions for the day-night asymmetry, spectrum distortion and NC/CC ratio at SNO are calculated. In the best fit points of the global solutions we find: A_{DN}^{CC} \approx (7 - 8)% for LMA, \sim 3% for LOW, and (2 - 3)% for SMA. It will be difficult to see the distortion of the spectrum expected for LMA as well as LOW solutions. However, future SNO spectral data can significantly affect the VAC and SMA solutions. We also calculate expectations for the BOREXINO rate.
1206.3444
Olena Romanets
O. Romanets, L. Tolos, C. Garcia-Recio, J. Nieves, L. L. Salcedo, R. G. E. Timmermans
Charmed baryon resonances with heavy-quark spin symmetry
6 pages, contribution to the proceedings of the Sixth International Conference on Quarks and Nuclear Physics (QNP2012), April 16-20, 2012, Palaiseau, France
null
null
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Charmed baryon resonances that are generated dynamically are studied within a unitary baryon-meson coupled-channel model, which incorporates heavy-quark spin symmetry. The extension of the SU(3) Weinberg-Tomozawa chiral Lagrangian to SU(8) spin-flavor symmetry plus a suitable symmetry breaking is used. The model produces resonances with negative parity from s-wave interaction of pseudoscalar and vector mesons with $1/2^+$ and $3/2^+$ baryons. Some of our dynamically generated states can be readily assigned to resonances found experimentally, while others do not have a straightforward identification and require the compilation of more data and also refinements of the model.
[ { "created": "Fri, 15 Jun 2012 12:37:40 GMT", "version": "v1" } ]
2012-06-18
[ [ "Romanets", "O.", "" ], [ "Tolos", "L.", "" ], [ "Garcia-Recio", "C.", "" ], [ "Nieves", "J.", "" ], [ "Salcedo", "L. L.", "" ], [ "Timmermans", "R. G. E.", "" ] ]
Charmed baryon resonances that are generated dynamically are studied within a unitary baryon-meson coupled-channel model, which incorporates heavy-quark spin symmetry. The extension of the SU(3) Weinberg-Tomozawa chiral Lagrangian to SU(8) spin-flavor symmetry plus a suitable symmetry breaking is used. The model produces resonances with negative parity from s-wave interaction of pseudoscalar and vector mesons with $1/2^+$ and $3/2^+$ baryons. Some of our dynamically generated states can be readily assigned to resonances found experimentally, while others do not have a straightforward identification and require the compilation of more data and also refinements of the model.
hep-ph/0206014
Mustafa Savci
T. M. Aliev, A. Ozpineci, M. Savci, C. Yuce
T violation in (Lambda_b -> Lambda l^+ l^-) decay beyond standard model
12 pages, 7 figures, LaTeX formatted
Phys.Lett.B542:229-238,2002
10.1016/S0370-2693(02)02381-X
metu-phys-hep-02-14
hep-ph
null
Using the most general, model independent form of effective Hamiltonian, the transverse polarization P_T of Lambda in Lambda_b -> Lambda l^+ l^- decay is studied. It is observed that the averaged <P_T> is very sensitive to the existence of new physics and can attain large values, which can be measured at future colliders.
[ { "created": "Mon, 3 Jun 2002 15:22:48 GMT", "version": "v1" } ]
2011-03-23
[ [ "Aliev", "T. M.", "" ], [ "Ozpineci", "A.", "" ], [ "Savci", "M.", "" ], [ "Yuce", "C.", "" ] ]
Using the most general, model independent form of effective Hamiltonian, the transverse polarization P_T of Lambda in Lambda_b -> Lambda l^+ l^- decay is studied. It is observed that the averaged <P_T> is very sensitive to the existence of new physics and can attain large values, which can be measured at future colliders.
hep-ph/9501207
null
T.W.B. Kibble and Alexander Vilenkin
Density of strings formed at a second-order cosmological phase transition
8 pages, REVTEX
null
null
IMPERIAL/TP/94-95/9, TUTP-95-1, NI94038
hep-ph astro-ph
null
We discuss the problem of estimating the characteristic length scale $\xi_{\rm s}$, and hence the initial density, of a system of cosmic strings formed at a continuous, second-order phase transition in the early universe. In particular, we examine the roles of the correlation length (or string width) $\xi_{\rm c}$ and the Ginzburg length $\xi_{\rm G}$ which defines the ``fuzziness'' of long strings. We argue that strings acquire a clear identity only once $\xi_{\rm s}$ exceeds both $\xi_{\rm c}$ and $\xi_{\rm G}$, and estimate its magnitude at that time.
[ { "created": "Wed, 4 Jan 1995 09:36:58 GMT", "version": "v1" } ]
2016-09-01
[ [ "Kibble", "T. W. B.", "" ], [ "Vilenkin", "Alexander", "" ] ]
We discuss the problem of estimating the characteristic length scale $\xi_{\rm s}$, and hence the initial density, of a system of cosmic strings formed at a continuous, second-order phase transition in the early universe. In particular, we examine the roles of the correlation length (or string width) $\xi_{\rm c}$ and the Ginzburg length $\xi_{\rm G}$ which defines the ``fuzziness'' of long strings. We argue that strings acquire a clear identity only once $\xi_{\rm s}$ exceeds both $\xi_{\rm c}$ and $\xi_{\rm G}$, and estimate its magnitude at that time.
1309.4391
Hua Xing Zhu
Ye Li and Hua Xing Zhu
Single soft gluon emission at two loops
typos corrected; journal version
JHEP11(2013)080
10.1007/JHEP11(2013)080
SLAC-PUB-15732
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the single soft-gluon current at two loops with two energetic partons in massless perturbative QCD, which describes, for example, the soft limit of the two-loop amplitude for $gg\to Hg$. The results are presented as Laurent expansions in $\epsilon$ in $D=4-2\epsilon$ spacetime dimension. We calculate the expansion to order $\epsilon^2$ analytically, which is a necessary ingredient for Higgs production at hadron colliders at next-to-next-to-next-to-leading order in the soft-virtual approximation. We also give two-loop results of the single soft-gluon current in ${\cal N}=4$ Super-Yang-Mills theory, and find that it has uniform transcendentality. By iteration relation of splitting amplitudes, our calculations can determine the three-loop single soft-gluon current to order $\epsilon^0$ in ${\cal N}=4$ Super-Yang-Mills theory in the limit of large $N_c$.
[ { "created": "Tue, 17 Sep 2013 17:00:52 GMT", "version": "v1" }, { "created": "Sat, 9 Nov 2013 00:08:26 GMT", "version": "v2" } ]
2013-11-20
[ [ "Li", "Ye", "" ], [ "Zhu", "Hua Xing", "" ] ]
We study the single soft-gluon current at two loops with two energetic partons in massless perturbative QCD, which describes, for example, the soft limit of the two-loop amplitude for $gg\to Hg$. The results are presented as Laurent expansions in $\epsilon$ in $D=4-2\epsilon$ spacetime dimension. We calculate the expansion to order $\epsilon^2$ analytically, which is a necessary ingredient for Higgs production at hadron colliders at next-to-next-to-next-to-leading order in the soft-virtual approximation. We also give two-loop results of the single soft-gluon current in ${\cal N}=4$ Super-Yang-Mills theory, and find that it has uniform transcendentality. By iteration relation of splitting amplitudes, our calculations can determine the three-loop single soft-gluon current to order $\epsilon^0$ in ${\cal N}=4$ Super-Yang-Mills theory in the limit of large $N_c$.
hep-ph/0603157
Giovanni Ossola
Giovanni Ossola
Hadronic mass and q^2 moments in B->Xu l nu
6 pages, to appear in the proceedings of the International Europhysics Conference on High Energy Physics (HEP-EPS 2005), Lisboa, Portugal, 21-27 July 2005
null
null
null
hep-ph
null
We present OPE predictions for the hadronic mass and q^2 moments in inclusive semileptonic charmless B decays, with a lower cut on the charged lepton energy and an upper cut on the hadronic invariant mass. We include non-perturbative corrections through O(1/m_b^3) and perturbative contributions through O(alpha_s^2 beta_0). We also investigate the range of the cut on the hadronic mass for which the local OPE can be considered valid and give estimates of the residual theoretical uncertainty. The study of these moments is important to constrain the effect of the Weak Annihilation (WA) contributions and the shape of the distribution function, providing a more precise inclusive determination of V_ub.
[ { "created": "Tue, 21 Mar 2006 13:41:54 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ossola", "Giovanni", "" ] ]
We present OPE predictions for the hadronic mass and q^2 moments in inclusive semileptonic charmless B decays, with a lower cut on the charged lepton energy and an upper cut on the hadronic invariant mass. We include non-perturbative corrections through O(1/m_b^3) and perturbative contributions through O(alpha_s^2 beta_0). We also investigate the range of the cut on the hadronic mass for which the local OPE can be considered valid and give estimates of the residual theoretical uncertainty. The study of these moments is important to constrain the effect of the Weak Annihilation (WA) contributions and the shape of the distribution function, providing a more precise inclusive determination of V_ub.
hep-ph/0002217
Manmohan Gupta
Monika Randhawa, V. Bhatnagar, P.S. Gill and M. Gupta
Implications of the Unitarity Triangle `uc' for J, $\delta$ and $|V_{CKM}|$ elements
14 pages, 3 figures (eps), updated in the light of latest PDG2000 data
Mod.Phys.Lett.A15:2363-2372,2000
10.1142/S0217732300002462
null
hep-ph
null
The Jarlskog rephasing invariant parameter $|J|$ is evaluated using one of the six Unitarity Triangles involving well known CKM matrix elements \vud, \vus,~\rub, ~\vcd, ~\vcs~ and ~\vcb. With PDG2000 values of \vud~ etc. as input, we obtain $|J|=(2.71 \pm 1.12) \times 10^{-5}$, which in the PDG representation of CKM matrix leads to the range $21^o~to~159^o$ for the CP violating phase $\delta$. The CKM matrix elements evaluated using this range of $\delta$ are in agreement with the PDG CKM matrix. The implications of refinements in the input on $|J|$, $\delta$ and CKM matrix elements have also been studied.
[ { "created": "Mon, 21 Feb 2000 08:03:18 GMT", "version": "v1" }, { "created": "Tue, 8 Aug 2000 11:30:53 GMT", "version": "v2" } ]
2014-11-17
[ [ "Randhawa", "Monika", "" ], [ "Bhatnagar", "V.", "" ], [ "Gill", "P. S.", "" ], [ "Gupta", "M.", "" ] ]
The Jarlskog rephasing invariant parameter $|J|$ is evaluated using one of the six Unitarity Triangles involving well known CKM matrix elements \vud, \vus,~\rub, ~\vcd, ~\vcs~ and ~\vcb. With PDG2000 values of \vud~ etc. as input, we obtain $|J|=(2.71 \pm 1.12) \times 10^{-5}$, which in the PDG representation of CKM matrix leads to the range $21^o~to~159^o$ for the CP violating phase $\delta$. The CKM matrix elements evaluated using this range of $\delta$ are in agreement with the PDG CKM matrix. The implications of refinements in the input on $|J|$, $\delta$ and CKM matrix elements have also been studied.
hep-ph/9810486
Christian Spieles
C. Spieles, R. Vogt, L. Gerland, S.A. Bass, M. Bleicher, L. Frankfurt, M. Strikman, H. Stoecker, W. Greiner
J/psi suppression in heavy ion collisions - interplay of hard and soft QCD processes
9 pages, 3 figures
null
null
LBNL-42410
hep-ph
null
We study J/psi suppression in AB collisions assuming that the charmonium states evolve from small, color transparent configurations. Their interaction with nucleons and nonequilibrated, secondary hadrons is simulated using the microscopic model UrQMD. The Drell-Yan lepton pair yield and the J/psi/Drell-Yan ratio are calculated as a function of the neutral transverse energy in Pb+Pb collisions at 160 GeV and found to be in reasonable agreement with existing data.
[ { "created": "Mon, 26 Oct 1998 20:08:12 GMT", "version": "v1" } ]
2007-05-23
[ [ "Spieles", "C.", "" ], [ "Vogt", "R.", "" ], [ "Gerland", "L.", "" ], [ "Bass", "S. A.", "" ], [ "Bleicher", "M.", "" ], [ "Frankfurt", "L.", "" ], [ "Strikman", "M.", "" ], [ "Stoecker", "H.", ...
We study J/psi suppression in AB collisions assuming that the charmonium states evolve from small, color transparent configurations. Their interaction with nucleons and nonequilibrated, secondary hadrons is simulated using the microscopic model UrQMD. The Drell-Yan lepton pair yield and the J/psi/Drell-Yan ratio are calculated as a function of the neutral transverse energy in Pb+Pb collisions at 160 GeV and found to be in reasonable agreement with existing data.
hep-ph/0702030
Peter Schweitzer
K.Goeke, J.Grabis, J.Ossmann, M.V.Polyakov, P.Schweitzer, A.Silva, D.Urbano
Nucleon form-factors of the energy momentum tensor in the chiral quark-soliton model
26 pages, 9 figures
Phys.Rev.D75:094021,2007
10.1103/PhysRevD.75.094021
RUB-TP2-05-2006
hep-ph
null
The nucleon form factors of the energy-momentum tensor are studied in the large-Nc limit in the framework of the chiral quark-soliton model.
[ { "created": "Fri, 2 Feb 2007 15:18:36 GMT", "version": "v1" } ]
2008-11-26
[ [ "Goeke", "K.", "" ], [ "Grabis", "J.", "" ], [ "Ossmann", "J.", "" ], [ "Polyakov", "M. V.", "" ], [ "Schweitzer", "P.", "" ], [ "Silva", "A.", "" ], [ "Urbano", "D.", "" ] ]
The nucleon form factors of the energy-momentum tensor are studied in the large-Nc limit in the framework of the chiral quark-soliton model.
hep-ph/0306218
Ernest Ma
Ernest Ma (UC Riverside)
Different G_F and sin^2(theta_W) for different processes
9 pages, talk at NUINT 02
null
null
UCRHEP-T355 (June 2003)
hep-ph
null
A natural theoretical framework is presented which allows for small departures from quark-lepton universality such that different G_F and sin^2(theta_W) values are applicable for different processes. In particular, the inequality (G_F)^{NC}_{lq} < (G_F)^{CC}_{lq} < (G_F)^{CC}_{ll} < (G_F)^{NC}_{ll} holds. New physics is predicted at the TeV scale.
[ { "created": "Mon, 23 Jun 2003 16:59:17 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ma", "Ernest", "", "UC Riverside" ] ]
A natural theoretical framework is presented which allows for small departures from quark-lepton universality such that different G_F and sin^2(theta_W) values are applicable for different processes. In particular, the inequality (G_F)^{NC}_{lq} < (G_F)^{CC}_{lq} < (G_F)^{CC}_{ll} < (G_F)^{NC}_{ll} holds. New physics is predicted at the TeV scale.
2206.00745
Uladzimir Khasianevich
Uladzimir Khasianevich, Wojciech Kotlarski, Dominik St\"ockinger
NPointFunctions: a calculator of amplitudes and observables in FlexibleSUSY
Contribution to Computational Tools for High Energy Physics and Cosmology (CompTools2021), 7 pages, 1 figure
null
null
null
hep-ph
http://creativecommons.org/licenses/by-nc-nd/4.0/
We present $\texttt{NPointFunctions}$, a package to incorporate desired amplitudes and observables for an arbitrary BSM model in $\texttt{FlexibleSUSY}$. The package relies on the $\texttt{SARAH}$-generated output used with $\texttt{FeynArts}/\texttt{FormCalc}$, embedded in an appropriate way, thus allowing calculations up to one-loop level. The resulting tool is an extension to $\texttt{FlexibleSUSY}$, a generator of spectrum generator programs. $\texttt{NPointFunctions}$ was designed to be customizable, modular and extensible with additional process- or amplitude- dependent contributions. We explain, how these goals are achieved, and discuss modifications to the default $\texttt{FlexibleSUSY}$ workflow.
[ { "created": "Wed, 1 Jun 2022 20:13:04 GMT", "version": "v1" } ]
2022-06-03
[ [ "Khasianevich", "Uladzimir", "" ], [ "Kotlarski", "Wojciech", "" ], [ "Stöckinger", "Dominik", "" ] ]
We present $\texttt{NPointFunctions}$, a package to incorporate desired amplitudes and observables for an arbitrary BSM model in $\texttt{FlexibleSUSY}$. The package relies on the $\texttt{SARAH}$-generated output used with $\texttt{FeynArts}/\texttt{FormCalc}$, embedded in an appropriate way, thus allowing calculations up to one-loop level. The resulting tool is an extension to $\texttt{FlexibleSUSY}$, a generator of spectrum generator programs. $\texttt{NPointFunctions}$ was designed to be customizable, modular and extensible with additional process- or amplitude- dependent contributions. We explain, how these goals are achieved, and discuss modifications to the default $\texttt{FlexibleSUSY}$ workflow.
1812.11529
Soeren Schlichting
S. Schlichting
Early time dynamics and hard probes in heavy-ion collisions
Proceedings of the Hard Probes 2018 conference, 30 Sept. - 5 Oct. 2018, Aix-les-Bains, France; 8 pages, 4 figures
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an overview of the current state of understanding of the early time dynamics of high-energy heavy-ion collisions, emphasizing recent developments and connections between the physics of the initial state and that of hard probes in heavy-ion collisions. Based on a weak-coupling description, we first establish a microscopic picture of the early time dynamics and equilibration process and subsequently discuss their macroscopic manifestations along with a novel macroscopic description of the pre-equilibrium phase. Some phenomenological consequences concerning the role of the pre-equilibrium phase in large (AA) and small (pp/pA) collision systems are briefly discussed along with open questions and opportunities for future improvements.
[ { "created": "Sun, 30 Dec 2018 13:37:46 GMT", "version": "v1" } ]
2019-01-01
[ [ "Schlichting", "S.", "" ] ]
We present an overview of the current state of understanding of the early time dynamics of high-energy heavy-ion collisions, emphasizing recent developments and connections between the physics of the initial state and that of hard probes in heavy-ion collisions. Based on a weak-coupling description, we first establish a microscopic picture of the early time dynamics and equilibration process and subsequently discuss their macroscopic manifestations along with a novel macroscopic description of the pre-equilibrium phase. Some phenomenological consequences concerning the role of the pre-equilibrium phase in large (AA) and small (pp/pA) collision systems are briefly discussed along with open questions and opportunities for future improvements.
1411.2810
Diego Cogollo
D. Cogollo
Muon anomalous magnetic moment in a $SU(4) \otimes U(1)_N$ model without exotic electric charges
arXiv admin note: text overlap with arXiv:1409.8115
Physics International, 2015, Volume 6, Issue 1,Pages 42-50
10.3844/pisp.2015.42.50
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study an electroweak gauge extension of the standard model, so called 3-4-1 model, which does not contain exotic electric charges and it is anomaly free. We discuss phenomenological constraints of the model and compute all the corrections to the muon magnetic moment. Mainly, we discuss different mass regimes and their impact on this correction, deriving for the first time direct limits on the masses of the neutral fermions and charged vector bosons. Interestingly, the model could address the reported muon anomalous magnetic moment excess, however it would demands a rather low scale of symmetry breaking, far below the current electroweak constraints on the model. Thus, if this excess is confirmed in the foreseeable future by the g-2 experiment at FERMILAB, this 3-4-1 model can be decisively ruled out since the model cannot reproduce a sizeable and positive contribution to the muon anomalous magnetic moment consistent with current electroweak limits.
[ { "created": "Tue, 11 Nov 2014 14:00:17 GMT", "version": "v1" } ]
2015-11-26
[ [ "Cogollo", "D.", "" ] ]
We study an electroweak gauge extension of the standard model, so called 3-4-1 model, which does not contain exotic electric charges and it is anomaly free. We discuss phenomenological constraints of the model and compute all the corrections to the muon magnetic moment. Mainly, we discuss different mass regimes and their impact on this correction, deriving for the first time direct limits on the masses of the neutral fermions and charged vector bosons. Interestingly, the model could address the reported muon anomalous magnetic moment excess, however it would demands a rather low scale of symmetry breaking, far below the current electroweak constraints on the model. Thus, if this excess is confirmed in the foreseeable future by the g-2 experiment at FERMILAB, this 3-4-1 model can be decisively ruled out since the model cannot reproduce a sizeable and positive contribution to the muon anomalous magnetic moment consistent with current electroweak limits.
1912.07337
Roberto Bruschini M.S.
Roberto Bruschini and Pedro Gonz\'alez
Strong decays of the lowest bottomonium hybrid within an extended Born-Oppenheimer framework
9 pages; v2: new title, major additions and modifications in the article body; v3: slight change in the title, new reference, clarifications and minor modifications in the article body
Eur. Phys. J. C 81, 74 (2021)
10.1140/epjc/s10052-021-08872-9
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the decays of the theoretically predicted lowest bottomonium hybrid $H(1P)$ to open bottom two-meson states. We do it by embedding a quark pair creation model into the Born-Oppenheimer framework which allows for a unified, QCD-motivated description of bottomonium hybrids as well as bottomonium. A new $^{1}\!P_{1}$ decay model for $H(1P)$ comes out. The same analysis applied to bottomonium leads naturally to the well-known $^{3}\!P_{0}$ decay model. We show that $H(1P)$ and the theoretically predicted bottomonium state $\Upsilon(5S)$, whose calculated masses are close to each other, have very different widths for such decays. A comparison with data from $\Upsilon(10860)$, an experimental resonance whose mass is similar to that of $\Upsilon(5S)$ and $H(1P)$, is carried out. Neither a $\Upsilon(5S)$ nor a $H(1P)$ assignment can explain the measured decay widths. However, a $\Upsilon(5S)$-$H(1P)$ mixing may give account of them supporting previous analyses of dipion decays of $\Upsilon(10860)$ and suggesting a possible experimental evidence of $H(1P)$.
[ { "created": "Mon, 16 Dec 2019 13:18:31 GMT", "version": "v1" }, { "created": "Fri, 25 Sep 2020 13:32:58 GMT", "version": "v2" }, { "created": "Wed, 13 Jan 2021 11:18:03 GMT", "version": "v3" } ]
2021-01-26
[ [ "Bruschini", "Roberto", "" ], [ "González", "Pedro", "" ] ]
We analyze the decays of the theoretically predicted lowest bottomonium hybrid $H(1P)$ to open bottom two-meson states. We do it by embedding a quark pair creation model into the Born-Oppenheimer framework which allows for a unified, QCD-motivated description of bottomonium hybrids as well as bottomonium. A new $^{1}\!P_{1}$ decay model for $H(1P)$ comes out. The same analysis applied to bottomonium leads naturally to the well-known $^{3}\!P_{0}$ decay model. We show that $H(1P)$ and the theoretically predicted bottomonium state $\Upsilon(5S)$, whose calculated masses are close to each other, have very different widths for such decays. A comparison with data from $\Upsilon(10860)$, an experimental resonance whose mass is similar to that of $\Upsilon(5S)$ and $H(1P)$, is carried out. Neither a $\Upsilon(5S)$ nor a $H(1P)$ assignment can explain the measured decay widths. However, a $\Upsilon(5S)$-$H(1P)$ mixing may give account of them supporting previous analyses of dipion decays of $\Upsilon(10860)$ and suggesting a possible experimental evidence of $H(1P)$.
hep-ph/0608023
Johannes Bluemlein
J. Bl\"umlein
O(\alpha_s^3) contributions to F_L^{Q\bar{Q}}(x,Q^2) for large virtualities
4 pages Latex, 1 style file
Nucl.Phys.Proc.Suppl.157:2-5,2006
10.1016/j.nuclphysbps.2006.03.001
DESY 05-003, SFB/CPP-06-06
hep-ph
null
The $O(\alpha_s^3)$ contributions to the heavy flavor Wilson coefficients for the structure function $F_L(x,Q^2)$ are calculated in the region $Q^2 \gg m^2$ using the renormalization group method.
[ { "created": "Wed, 2 Aug 2006 19:07:57 GMT", "version": "v1" } ]
2010-05-19
[ [ "Blümlein", "J.", "" ] ]
The $O(\alpha_s^3)$ contributions to the heavy flavor Wilson coefficients for the structure function $F_L(x,Q^2)$ are calculated in the region $Q^2 \gg m^2$ using the renormalization group method.
1901.01778
Cheng Zhang
Cheng Zhang, Manyika Kabuswa Davy, Yu Shi, Enke Wang
Multiparticle azimuthal angular correlations in $pA$ collisions
null
Phys. Rev. D 99, 034009 (2019)
10.1103/PhysRevD.99.034009
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
In the Color Glass Condensate formalism, we evaluate the 3-dipole correlator up to the $\frac{1}{N_c^4}$ order with $N_c$ being the number of colors, and compute the azimuthal cumulant $c_{123}$ for 3-particle productions. In addition, we discuss the patterns appearing in the $n$-dipole formula in terms of $\frac{1}{N_c}$ expansions. This allows us to conjecture the $N_c$ scaling of $c_n\{m\}$, which is crosschecked by our calculation of $c_2\{4\}$ in the dilute limit.
[ { "created": "Mon, 7 Jan 2019 12:41:33 GMT", "version": "v1" }, { "created": "Wed, 9 Jan 2019 07:09:26 GMT", "version": "v2" }, { "created": "Sat, 23 Feb 2019 13:21:21 GMT", "version": "v3" } ]
2019-02-27
[ [ "Zhang", "Cheng", "" ], [ "Davy", "Manyika Kabuswa", "" ], [ "Shi", "Yu", "" ], [ "Wang", "Enke", "" ] ]
In the Color Glass Condensate formalism, we evaluate the 3-dipole correlator up to the $\frac{1}{N_c^4}$ order with $N_c$ being the number of colors, and compute the azimuthal cumulant $c_{123}$ for 3-particle productions. In addition, we discuss the patterns appearing in the $n$-dipole formula in terms of $\frac{1}{N_c}$ expansions. This allows us to conjecture the $N_c$ scaling of $c_n\{m\}$, which is crosschecked by our calculation of $c_2\{4\}$ in the dilute limit.
1306.1564
Bob Holdom
B. Holdom
Far from standard Higgs couplings
5 pages, 10 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this short note we consider a permitted region in the space of couplings of the 126 GeV boson that extends far away from the standard model Higgs couplings. This region is of interest for more natural models of electroweak symmetry breaking. Stronger evidence of vector boson fusion and/or associated production is needed to eliminate this possibility.
[ { "created": "Thu, 6 Jun 2013 21:48:36 GMT", "version": "v1" } ]
2013-06-10
[ [ "Holdom", "B.", "" ] ]
In this short note we consider a permitted region in the space of couplings of the 126 GeV boson that extends far away from the standard model Higgs couplings. This region is of interest for more natural models of electroweak symmetry breaking. Stronger evidence of vector boson fusion and/or associated production is needed to eliminate this possibility.
0804.2530
Jose Antonio Oller
J.A. Oller, L. Roca, C. Schat
S-wave \gamma\gamma\to \pi\pi and f_0(980)\to \pi\pi
6 pages, 1 figure. Prepared for the Workshop on Scalar Mesons and Related Topics, Lisbon, 11-16 Feburary 2008
AIPConf.Proc.1030:147-152,2008
10.1063/1.2973490
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We report on a dispersion relation for the \gamma\gamma\to (\pi\pi)_I S-wave in isospin I emphasizing the low energy region. The f_0(980) signal that emerges in \gamma\gamma\to \pi\pi is also discussed. Our results could be used to distinguish between different \pi\pi isoscalar S-wave parameterizations. We also calculate the width of the \sigma resonance to \gamma\gamma and obtain the value \Gamma(\sigma\to\gamma\gamma)=(1.68\pm 0.15) KeV. Finally, we elaborate on the size of the f_0(980) coupling to \pi\pi and show that its smallness compared to the K\bar{K} one is not related to the OZI rule.
[ { "created": "Wed, 16 Apr 2008 06:54:44 GMT", "version": "v1" } ]
2008-11-26
[ [ "Oller", "J. A.", "" ], [ "Roca", "L.", "" ], [ "Schat", "C.", "" ] ]
We report on a dispersion relation for the \gamma\gamma\to (\pi\pi)_I S-wave in isospin I emphasizing the low energy region. The f_0(980) signal that emerges in \gamma\gamma\to \pi\pi is also discussed. Our results could be used to distinguish between different \pi\pi isoscalar S-wave parameterizations. We also calculate the width of the \sigma resonance to \gamma\gamma and obtain the value \Gamma(\sigma\to\gamma\gamma)=(1.68\pm 0.15) KeV. Finally, we elaborate on the size of the f_0(980) coupling to \pi\pi and show that its smallness compared to the K\bar{K} one is not related to the OZI rule.
0902.4405
Yuji Kajiyama
Yuji Kajiyama, Shaaban Khalil and Martti Raidal
Electron EDM and soft leptogenesis in supersymmetric B-L extension of the standard model
21 pages, 4 figures, minor changes, published version
Nucl.Phys.B820:75-88,2009
10.1016/j.nuclphysb.2009.05.011
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the connection between electric dipole moment of the electron and the soft leptogenesis in supersymmetric $B-L$ extension of the standard model. In this model, the $B-L$ symmetry is radiatively broken at TeV scale. Therefore, it is a natural framework for low scale seesaw mechanism and also for implementing the soft leptogenesis. We show that the phases of trilinear soft SUSY breaking couplings $A$, which are relevant for the lepton asymmetry, are not constrained by the present experimental bounds on electric dipole moment. As in the MSSM extended with right-handed neutrinos, successful leptogenesis requires small bilinear coupling $B$, which is now given by $A_N$ and $B-L$ breaking VEVs. SUSY $B-L$ model with non-universal $A$-terms such that $A_N=0$ while $A_{\nu}\neq0$ is a promising scenario for soft leptogenesis. The proposed EDM experiments will test this scenario in the future.
[ { "created": "Wed, 25 Feb 2009 15:58:47 GMT", "version": "v1" }, { "created": "Thu, 9 Jul 2009 09:59:10 GMT", "version": "v2" } ]
2010-04-15
[ [ "Kajiyama", "Yuji", "" ], [ "Khalil", "Shaaban", "" ], [ "Raidal", "Martti", "" ] ]
We analyze the connection between electric dipole moment of the electron and the soft leptogenesis in supersymmetric $B-L$ extension of the standard model. In this model, the $B-L$ symmetry is radiatively broken at TeV scale. Therefore, it is a natural framework for low scale seesaw mechanism and also for implementing the soft leptogenesis. We show that the phases of trilinear soft SUSY breaking couplings $A$, which are relevant for the lepton asymmetry, are not constrained by the present experimental bounds on electric dipole moment. As in the MSSM extended with right-handed neutrinos, successful leptogenesis requires small bilinear coupling $B$, which is now given by $A_N$ and $B-L$ breaking VEVs. SUSY $B-L$ model with non-universal $A$-terms such that $A_N=0$ while $A_{\nu}\neq0$ is a promising scenario for soft leptogenesis. The proposed EDM experiments will test this scenario in the future.
1202.1226
Barun Majumder
Barun Majumder
Effects of the Modified Uncertainty Principle on the Inflation Parameters
new references added
Physics Letters B 709 (2012) 133-136
10.1016/j.physletb.2012.02.022
null
hep-ph astro-ph.CO gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this Letter we study the effects of the Modified Uncertainty Principle as proposed in [8] on the inflationary dynamics of the early universe in both standard and Randall-Sundrum type II scenarios. We find that the quantum gravitational effect increase the amplitude of density fluctuation, which is oscillatory in nature, with an increase in the tensor-to-scalar ratio.
[ { "created": "Mon, 6 Feb 2012 18:00:15 GMT", "version": "v1" }, { "created": "Fri, 24 Feb 2012 10:54:59 GMT", "version": "v2" } ]
2012-02-27
[ [ "Majumder", "Barun", "" ] ]
In this Letter we study the effects of the Modified Uncertainty Principle as proposed in [8] on the inflationary dynamics of the early universe in both standard and Randall-Sundrum type II scenarios. We find that the quantum gravitational effect increase the amplitude of density fluctuation, which is oscillatory in nature, with an increase in the tensor-to-scalar ratio.
0801.3686
Kathryn Zurek
Dan Hooper, Kathryn M. Zurek
A Natural Supersymmetric Model with MeV Dark Matter
4 pages, 1 figure. v2: Small modification to discussion of spectrum
Phys.Rev.D77:087302,2008
10.1103/PhysRevD.77.087302
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It has previously been proposed that annihilating dark matter particles with MeV-scale masses could be responsible for the flux of 511 keV photons observed from the region of the Galactic Bulge. The conventional wisdom, however, is that it is very challenging to construct a viable particle physics model containing MeV dark matter. In this letter, we challenge this conclusion by describing a simple and natural supersymmetric model in which the lightest supersymmetric particle naturally has a MeV-scale mass and the other phenomenological properties required to generate the 511 keV emission. In particular, the small ($\sim$ $10^{-5}$) effective couplings between dark matter and the Standard Model fermions required in this scenario naturally lead to radiative corrections that generate MeV-scale masses for both the dark matter candidate and the mediator particle.
[ { "created": "Thu, 24 Jan 2008 14:47:36 GMT", "version": "v1" }, { "created": "Wed, 3 Dec 2008 04:20:46 GMT", "version": "v2" }, { "created": "Mon, 13 Jul 2009 21:57:58 GMT", "version": "v3" } ]
2009-07-14
[ [ "Hooper", "Dan", "" ], [ "Zurek", "Kathryn M.", "" ] ]
It has previously been proposed that annihilating dark matter particles with MeV-scale masses could be responsible for the flux of 511 keV photons observed from the region of the Galactic Bulge. The conventional wisdom, however, is that it is very challenging to construct a viable particle physics model containing MeV dark matter. In this letter, we challenge this conclusion by describing a simple and natural supersymmetric model in which the lightest supersymmetric particle naturally has a MeV-scale mass and the other phenomenological properties required to generate the 511 keV emission. In particular, the small ($\sim$ $10^{-5}$) effective couplings between dark matter and the Standard Model fermions required in this scenario naturally lead to radiative corrections that generate MeV-scale masses for both the dark matter candidate and the mediator particle.
hep-ph/0007246
Alexander Kusenko
Alexander Kusenko and Marieke Postma
Neutrinos produced by ultrahigh-energy photons at high red shift
4 pages, revtex; to appear in Phys. Rev. Lett
Phys.Rev.Lett. 86 (2001) 1430-1433
10.1103/PhysRevLett.86.1430
UCLA/00/TEP/22; BNL-HET-00/26
hep-ph astro-ph
null
Some of the proposed explanations for the origin of ultrahigh-energy cosmic rays invoke new sources of energetic photons (e.g., topological defects, relic particles, etc.). At high red shift, when the cosmic microwave background has a higher temperature but the radio background is low, the ultrahigh-energy photons can generate neutrinos through pair-production of muons and pions. Neutrinos produced at high red shift by slowly evolving sources can be detected. Rapidly evolving sources of photons can be ruled out based on the existing upper limit on the neutrino flux.
[ { "created": "Sun, 23 Jul 2000 07:41:14 GMT", "version": "v1" }, { "created": "Mon, 24 Jul 2000 23:52:44 GMT", "version": "v2" }, { "created": "Mon, 25 Dec 2000 04:49:13 GMT", "version": "v3" } ]
2009-10-31
[ [ "Kusenko", "Alexander", "" ], [ "Postma", "Marieke", "" ] ]
Some of the proposed explanations for the origin of ultrahigh-energy cosmic rays invoke new sources of energetic photons (e.g., topological defects, relic particles, etc.). At high red shift, when the cosmic microwave background has a higher temperature but the radio background is low, the ultrahigh-energy photons can generate neutrinos through pair-production of muons and pions. Neutrinos produced at high red shift by slowly evolving sources can be detected. Rapidly evolving sources of photons can be ruled out based on the existing upper limit on the neutrino flux.
0810.3842
Jaroslav Trnka
Karol Kampf, Jiri Novotny, Jaroslav Trnka
Renormalization of the antisymmetric tensor field propagator and dynamical generation of the $1^{+-}$ mesons in Resonance Chiral Theory
4 pages, 1 figure, to appear in Proceedings of the conference QCD 08, Montpellier, 7-12 July 2008
Nucl.Phys.Proc.Suppl.186:153-156,2009
10.1016/j.nuclphysbps.2008.12.036
PSI-PR-08-14, PUPT-2283
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the renormalization of the $1^{--}$ vector meson propagator within Resonance chiral theory at one loop. Using the particular form of the interaction Lagrangian we show that additional poles of the renormalized propagator corresponding to $1^{+-}$ degrees of freedom can be generated. We give a concrete example of such an effect.
[ { "created": "Tue, 21 Oct 2008 14:27:10 GMT", "version": "v1" } ]
2009-04-30
[ [ "Kampf", "Karol", "" ], [ "Novotny", "Jiri", "" ], [ "Trnka", "Jaroslav", "" ] ]
We discuss the renormalization of the $1^{--}$ vector meson propagator within Resonance chiral theory at one loop. Using the particular form of the interaction Lagrangian we show that additional poles of the renormalized propagator corresponding to $1^{+-}$ degrees of freedom can be generated. We give a concrete example of such an effect.
0912.4652
Alexander Bednyakov
A.V. Bednyakov
On the two-loop decoupling corrections to tau-lepton and b-quark running masses in the MSSM
21 pages, 4 figures
Int.J.Mod.Phys.A25:2437-2456,2010
10.1142/S0217751X10048494
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Masses of heavy Standard Model fermions (top-quark, bottom-quark, and tau-lepton) play an important role in the analysis of theories beyond the SM. They serve as low-energy input and reduce the parameter space of such theories. In this paper Minimal supersymmetric extension of the SM is considered and two-loop relations between known SM values of fermion masses and running parameters of the MSSM are studied within the effective theory approach. Both b-quark and tau-lepton have the same quantum numbers with respect to SU(2) groupand in the MSSM acquire their masses due to interactions with the same Higgs doublet. As a consequence, for large values of tan beta parameter corresponding Yukawa couplings also become large and together with tan beta can significantly enhance radiative corrections. In the case of b-quark two-loop O(alpha_s^2) contribution to the relation between running bottom-quark mass in QCD and MSSM is known in literature. This paper is devoted to calculation of the NNLO corrections proportional to Yukawa couplings. For the tau-lepton obtained contribution can be considered as a good approximation to the full two-loop result. For the b-quark numerical analysis given in the paper shows that only the sum of strong and Yukawa corrections can play such a role.
[ { "created": "Wed, 23 Dec 2009 14:57:20 GMT", "version": "v1" } ]
2010-05-25
[ [ "Bednyakov", "A. V.", "" ] ]
Masses of heavy Standard Model fermions (top-quark, bottom-quark, and tau-lepton) play an important role in the analysis of theories beyond the SM. They serve as low-energy input and reduce the parameter space of such theories. In this paper Minimal supersymmetric extension of the SM is considered and two-loop relations between known SM values of fermion masses and running parameters of the MSSM are studied within the effective theory approach. Both b-quark and tau-lepton have the same quantum numbers with respect to SU(2) groupand in the MSSM acquire their masses due to interactions with the same Higgs doublet. As a consequence, for large values of tan beta parameter corresponding Yukawa couplings also become large and together with tan beta can significantly enhance radiative corrections. In the case of b-quark two-loop O(alpha_s^2) contribution to the relation between running bottom-quark mass in QCD and MSSM is known in literature. This paper is devoted to calculation of the NNLO corrections proportional to Yukawa couplings. For the tau-lepton obtained contribution can be considered as a good approximation to the full two-loop result. For the b-quark numerical analysis given in the paper shows that only the sum of strong and Yukawa corrections can play such a role.
2211.14129
Kazem Azizi
S. S. Agaev, K. Azizi, H. Sundu
Resonance $X(3960)$ as a hidden charm-strange scalar tetraquark
13 Pages, 5 Figures and 1 Table
null
10.1103/PhysRevD.107.054017
null
hep-ph hep-ex hep-lat
http://creativecommons.org/licenses/by/4.0/
We investigate features of the hidden charm-strange scalar tetraquark $c \overline{c}s\overline{s}$ by calculating its spectral parameters and width, and we compare the obtained results with the mass and width of the resonance $ X(3960)$ discovered recently in the LHCb experiment. We model the tetraquark as a diquark-antidiquark state $X=[cs][\overline{c}\overline{s}]$ with spin-parities $J^{\mathrm{PC}}=0^{++}$. The mass and current coupling of $X$ are calculated using the QCD two-point sum rules by taking into account various vacuum condensates up to dimension $10$. The width of the tetraquark $X$ is estimated via the decay channels $X \to D_{s}^{+}D_{s}^{-}$ and $X \to \eta_{c} \eta^{(\prime)}$. The partial widths of these processes are expressed in terms of couplings $G$, $g_1$ and $g_2$ which describe the strong interactions of particles at the vertices $XD_{s}^{+}D_{s}^{-}$, $ X\eta_{c}\eta^{\prime}$ and $X\eta_{c}\eta$, respectively. Numerical values of $G$, $g_1$ and $g_2$ are evaluated by employing the three-point sum rule method. Comparing the results $m=(3976 \pm 85)~\mathrm{MeV}$ and $\Gamma_{ \mathrm{X}}=(42.2 \pm 12.0)~\mathrm{MeV}$ obtained for parameters of the tetraquark $X$ and experimental data of the LHCb Collaboration, we conclude that the resonance $X(3960)$ can be considered as a candidate to a scalar diquark-antidiquark state.
[ { "created": "Fri, 25 Nov 2022 14:12:01 GMT", "version": "v1" }, { "created": "Sun, 26 Feb 2023 17:23:33 GMT", "version": "v2" } ]
2023-03-29
[ [ "Agaev", "S. S.", "" ], [ "Azizi", "K.", "" ], [ "Sundu", "H.", "" ] ]
We investigate features of the hidden charm-strange scalar tetraquark $c \overline{c}s\overline{s}$ by calculating its spectral parameters and width, and we compare the obtained results with the mass and width of the resonance $ X(3960)$ discovered recently in the LHCb experiment. We model the tetraquark as a diquark-antidiquark state $X=[cs][\overline{c}\overline{s}]$ with spin-parities $J^{\mathrm{PC}}=0^{++}$. The mass and current coupling of $X$ are calculated using the QCD two-point sum rules by taking into account various vacuum condensates up to dimension $10$. The width of the tetraquark $X$ is estimated via the decay channels $X \to D_{s}^{+}D_{s}^{-}$ and $X \to \eta_{c} \eta^{(\prime)}$. The partial widths of these processes are expressed in terms of couplings $G$, $g_1$ and $g_2$ which describe the strong interactions of particles at the vertices $XD_{s}^{+}D_{s}^{-}$, $ X\eta_{c}\eta^{\prime}$ and $X\eta_{c}\eta$, respectively. Numerical values of $G$, $g_1$ and $g_2$ are evaluated by employing the three-point sum rule method. Comparing the results $m=(3976 \pm 85)~\mathrm{MeV}$ and $\Gamma_{ \mathrm{X}}=(42.2 \pm 12.0)~\mathrm{MeV}$ obtained for parameters of the tetraquark $X$ and experimental data of the LHCb Collaboration, we conclude that the resonance $X(3960)$ can be considered as a candidate to a scalar diquark-antidiquark state.
1608.02716
Christophe Bronner
Christophe Bronner
Generators for the SIS/DIS region
8 pages, 8 figures. Proceedings for a talk presented at NuINT2015
null
10.7566/JPSCP.12.010025
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We describe how the main neutrino interaction generators (GENIE, NEUT and NuWro) used by current neutrino oscillation experiments treat the shallow and deep inelastic region. We then compare their predictions for charged current events in this region, in terms of transferred momentum as well as multiplicities for different types of hadrons. We present additional comparisons in the low hadronic invariant mass region, where the generators use different custom models.
[ { "created": "Tue, 9 Aug 2016 08:24:01 GMT", "version": "v1" } ]
2016-12-21
[ [ "Bronner", "Christophe", "" ] ]
We describe how the main neutrino interaction generators (GENIE, NEUT and NuWro) used by current neutrino oscillation experiments treat the shallow and deep inelastic region. We then compare their predictions for charged current events in this region, in terms of transferred momentum as well as multiplicities for different types of hadrons. We present additional comparisons in the low hadronic invariant mass region, where the generators use different custom models.
1701.01464
Stefano Forte
Claudio Muselli, Stefano Forte, Giovanni Ridolfi
Combined threshold and transverse momentum resummation for inclusive observables
TIF-UNIMI-2016-11. Final version, to be published in JHEP. Modified references to the collinear anomaly; typos corrected in eqs 2.16, 2.18, 2.25, 3.7
null
10.1007/JHEP03(2017)106
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a combined resummation for the transverse momentum distribution of a colorless final state in perturbative QCD, expressed as a function of transverse momentum pt and the scaling variable x. Its expression satisfies three requirements: it reduces to standard transverse momentum resummation to any desired logarithmic order in the limit pt-> 0 for fixed x, up to power suppressed corrections in pt; it reduces to threshold resummation to any desired logarithmic order in the limit x-> 1 for fixed pt, up to power suppressed correction in 1-x; upon integration over transverse momentum it reproduces the resummation of the total cross cross at any given logarithmic order in the threshold x->1 limit. Its main ingredient, and our main new result, is a modified form of transverse momentum resummation, which leads to threshold resummation upon integration over pt, and for which we provide a simple closed-form analytic expression in Fourier-Mellin (b,N) space. We give explicit coefficients up to NNLL order for the specific case of Higgs production in gluon fusion in the effective field theory limit. Our result allows for a systematic improvement of the transverse momentum distribution through threshold resummation which holds for all pt, and elucidates the relation between transverse momentum resummation and threshold resummation at the inclusive level, specifically by providing within perturbative QCD a simple derivation of the main consequence of the so-called collinear anomaly of SCET.
[ { "created": "Thu, 5 Jan 2017 19:58:05 GMT", "version": "v1" }, { "created": "Mon, 9 Jan 2017 16:40:52 GMT", "version": "v2" }, { "created": "Wed, 8 Mar 2017 14:04:33 GMT", "version": "v3" } ]
2017-04-26
[ [ "Muselli", "Claudio", "" ], [ "Forte", "Stefano", "" ], [ "Ridolfi", "Giovanni", "" ] ]
We present a combined resummation for the transverse momentum distribution of a colorless final state in perturbative QCD, expressed as a function of transverse momentum pt and the scaling variable x. Its expression satisfies three requirements: it reduces to standard transverse momentum resummation to any desired logarithmic order in the limit pt-> 0 for fixed x, up to power suppressed corrections in pt; it reduces to threshold resummation to any desired logarithmic order in the limit x-> 1 for fixed pt, up to power suppressed correction in 1-x; upon integration over transverse momentum it reproduces the resummation of the total cross cross at any given logarithmic order in the threshold x->1 limit. Its main ingredient, and our main new result, is a modified form of transverse momentum resummation, which leads to threshold resummation upon integration over pt, and for which we provide a simple closed-form analytic expression in Fourier-Mellin (b,N) space. We give explicit coefficients up to NNLL order for the specific case of Higgs production in gluon fusion in the effective field theory limit. Our result allows for a systematic improvement of the transverse momentum distribution through threshold resummation which holds for all pt, and elucidates the relation between transverse momentum resummation and threshold resummation at the inclusive level, specifically by providing within perturbative QCD a simple derivation of the main consequence of the so-called collinear anomaly of SCET.
1412.7540
Marat Freytsis
Marat Freytsis, Tomer Volansky, Jonathan R. Walsh
Tagging Partially Reconstructed Objects with Jet Substructure
6 pages, 4 figures
null
10.1016/j.physletb.2016.08.044
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a new tagger which aims at identifying partially reconstructed objects, in which only some of the constituents are collected in a single jet. As an example, we focus on top decays in which either part of the hadronically decaying W or the b jet is soft or falls outside of the top jet cone. We construct an observable to identify remnant substructure from the decay and employ aggressive jet grooming to reject QCD backgrounds. The tagger is complementary to existing ones and works well in the intermediate boost regime where jet substructure techniques usually fail. It is anticipated that a similar tagger can be used to identify non-QCD hadronic jets, such as those expected from hidden valleys.
[ { "created": "Tue, 23 Dec 2014 21:00:05 GMT", "version": "v1" } ]
2016-08-31
[ [ "Freytsis", "Marat", "" ], [ "Volansky", "Tomer", "" ], [ "Walsh", "Jonathan R.", "" ] ]
We present a new tagger which aims at identifying partially reconstructed objects, in which only some of the constituents are collected in a single jet. As an example, we focus on top decays in which either part of the hadronically decaying W or the b jet is soft or falls outside of the top jet cone. We construct an observable to identify remnant substructure from the decay and employ aggressive jet grooming to reject QCD backgrounds. The tagger is complementary to existing ones and works well in the intermediate boost regime where jet substructure techniques usually fail. It is anticipated that a similar tagger can be used to identify non-QCD hadronic jets, such as those expected from hidden valleys.
0908.4149
Jonathan Debove
Jonathan Debove
Transverse-momentum resummation for gaugino-pair production at the LHC
4 pages, 2 figures, presented at the 2009 Europhysics Conference on High Energy Physics, 16-22 July 2009, Krakow, Poland
PoS EPS-HEP2009 2009:318,2009
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a first precision analysis of the transverse-momentum spectrum of gaugino pairs produced at the LHC with center-of-mass energies of 10 or 14 TeV. Our calculation is based on a universal resummation formalism at next-to-leading logarithmic accuracy, which is consistently matched to the perturbative prediction at O(alpha_s). Numerical results are given for the ``gold-plated'' associated production of neutralinos and charginos for a typical benchmark point in the constrained Minimal Supersymmetric Standard Model. We show that the matched resummation results differ considerably from the Monte Carlo predictions employed traditionally in experimental analyses. We also investigate in detail the theoretical uncertainties coming from scale and parton-density function variations and non-perturbative effects.
[ { "created": "Fri, 28 Aug 2009 12:27:58 GMT", "version": "v1" } ]
2014-11-20
[ [ "Debove", "Jonathan", "" ] ]
We present a first precision analysis of the transverse-momentum spectrum of gaugino pairs produced at the LHC with center-of-mass energies of 10 or 14 TeV. Our calculation is based on a universal resummation formalism at next-to-leading logarithmic accuracy, which is consistently matched to the perturbative prediction at O(alpha_s). Numerical results are given for the ``gold-plated'' associated production of neutralinos and charginos for a typical benchmark point in the constrained Minimal Supersymmetric Standard Model. We show that the matched resummation results differ considerably from the Monte Carlo predictions employed traditionally in experimental analyses. We also investigate in detail the theoretical uncertainties coming from scale and parton-density function variations and non-perturbative effects.
2105.09686
Yusuf Gunaydin
Gural Aydin (Hatay Mustafa Kemal University), Yusuf Oguzhan G\"unaydin (Kahramanmaras S\"utc\"u Imam University), Mehmet Sahin (Usak University), Saleh Sultansoy (TOBB ETU), Mehmet T\"urker Tarakcioglu (Kahramanmaras S\"utc\"u Imam University)
Contact Interactions at Future Circular Collider based Muon-Proton Colliders
10 pages, 8 figures, and 7 tables
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently proposed Future Circular Collider based muon-proton colliders will allow investigating lepton-hadron interactions at the highest center-of-mass energy. In this study, we investigate the potential of these colliders for a four-fermion contact interactions search. Regarding the constructive and destructive interferences of contact interactions, we estimated discovery, observation, and exclusion limits on the compositeness scale for the left-left, right-right, left-right, and right-left helicity structures. This study's findings show that the FCC-based {\mu}p colliders have great potential for investigating four-fermion contact interactions.
[ { "created": "Thu, 20 May 2021 11:55:27 GMT", "version": "v1" }, { "created": "Wed, 23 Jun 2021 12:48:12 GMT", "version": "v2" }, { "created": "Mon, 4 Jul 2022 14:55:44 GMT", "version": "v3" }, { "created": "Thu, 3 Nov 2022 17:00:15 GMT", "version": "v4" } ]
2022-11-04
[ [ "Aydin", "Gural", "", "Hatay Mustafa Kemal University" ], [ "Günaydin", "Yusuf Oguzhan", "", "Kahramanmaras Sütcü Imam University" ], [ "Sahin", "Mehmet", "", "Usak University" ], [ "Sultansoy", "Saleh", "", "TOBB ETU" ], [ "Tarak...
Recently proposed Future Circular Collider based muon-proton colliders will allow investigating lepton-hadron interactions at the highest center-of-mass energy. In this study, we investigate the potential of these colliders for a four-fermion contact interactions search. Regarding the constructive and destructive interferences of contact interactions, we estimated discovery, observation, and exclusion limits on the compositeness scale for the left-left, right-right, left-right, and right-left helicity structures. This study's findings show that the FCC-based {\mu}p colliders have great potential for investigating four-fermion contact interactions.
2307.16831
Yannick Ulrich
T. Engel, F. Hagelstein, M. Rocco, V. Sharkovska, A. Signer, Y. Ulrich
Impact of NNLO QED corrections on lepton-proton scattering at MUSE
Article to be submitted to the EPJ A Topical Collection: Radiative Corrections: From Medium to High Energy Experiments. 23 pages, 9 figures
null
null
FR-PHENO-2023-08, IPPP/23/39, PSI-PR-23-27, ZU-TH 39/23, MITP-23-040
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the complete next-to-next-to-leading order (NNLO) pure pointlike QED corrections to lepton-proton scattering, including three-photon-exchange contributions, and investigate their impact in the case of the MUSE experiment. These corrections are computed with no approximation regarding the energy of the emitted photons and taking into account lepton-mass effects. We contrast the NNLO QED corrections to known next-to-leading order corrections, where we include the elastic two-photon exchange (TPE) through a simple hadronic model calculation with a dipole ansatz for the proton electromagnetic form factors. We show that, in the low-momentum-transfer region accessed by the MUSE experiment, the improvement due to more sophisticated treatments of the TPE, including inelastic TPE, is of similar if not smaller size than some of the NNLO QED corrections. Hence, the latter have to be included in a precision determination of the low-energy proton structure from scattering data, in particular for electron-proton scattering. For muon-proton scattering, the NNLO QED corrections are considerably smaller.
[ { "created": "Mon, 31 Jul 2023 16:55:02 GMT", "version": "v1" } ]
2023-08-04
[ [ "Engel", "T.", "" ], [ "Hagelstein", "F.", "" ], [ "Rocco", "M.", "" ], [ "Sharkovska", "V.", "" ], [ "Signer", "A.", "" ], [ "Ulrich", "Y.", "" ] ]
We present the complete next-to-next-to-leading order (NNLO) pure pointlike QED corrections to lepton-proton scattering, including three-photon-exchange contributions, and investigate their impact in the case of the MUSE experiment. These corrections are computed with no approximation regarding the energy of the emitted photons and taking into account lepton-mass effects. We contrast the NNLO QED corrections to known next-to-leading order corrections, where we include the elastic two-photon exchange (TPE) through a simple hadronic model calculation with a dipole ansatz for the proton electromagnetic form factors. We show that, in the low-momentum-transfer region accessed by the MUSE experiment, the improvement due to more sophisticated treatments of the TPE, including inelastic TPE, is of similar if not smaller size than some of the NNLO QED corrections. Hence, the latter have to be included in a precision determination of the low-energy proton structure from scattering data, in particular for electron-proton scattering. For muon-proton scattering, the NNLO QED corrections are considerably smaller.
hep-ph/9706472
Amir Fariborz
V. Elias, A. H. Fariborz, M. A. Samuel, Fang Shi and T. G. Steele
Beyond the Narrow Resonance Approximation: Decay Constant and Width of the First Pion-Excitation State
9 pages, revtex, no figures, accepted for publication in Phys. Lett. B
Phys.Lett. B412 (1997) 131-136
10.1016/S0370-2693(97)01049-6
null
hep-ph
null
We consider the first pion excitation as a sub-continuum resonance in the pseudoscalar channel, and we obtain parameters characterizing this resonance through a global fit of the Borel-parameter dependence of the field-theoretical pseudoscalar Laplace sum rule to its hadronic (pion + pion-excitation + QCD-continuum) content. Our analysis incorporates finite-width deviations from the narrow resonance approximation, instanton effects, and higher-loop perturbative contributions to the pseudoscalar correlator. We obtain the following values (uncertainties reflect 90% confidence levels): mass $M_\Pi = 1.15 \pm 0.28 GeV$, width $\Gamma_\Pi = < 0.48 GeV$, decay constant $r \equiv [F_\Pi M_\Pi^2 / f_\pi m_\pi^2]^2 = 4.7 \pm 2.8$.
[ { "created": "Mon, 23 Jun 1997 21:45:09 GMT", "version": "v1" } ]
2016-09-06
[ [ "Elias", "V.", "" ], [ "Fariborz", "A. H.", "" ], [ "Samuel", "M. A.", "" ], [ "Shi", "Fang", "" ], [ "Steele", "T. G.", "" ] ]
We consider the first pion excitation as a sub-continuum resonance in the pseudoscalar channel, and we obtain parameters characterizing this resonance through a global fit of the Borel-parameter dependence of the field-theoretical pseudoscalar Laplace sum rule to its hadronic (pion + pion-excitation + QCD-continuum) content. Our analysis incorporates finite-width deviations from the narrow resonance approximation, instanton effects, and higher-loop perturbative contributions to the pseudoscalar correlator. We obtain the following values (uncertainties reflect 90% confidence levels): mass $M_\Pi = 1.15 \pm 0.28 GeV$, width $\Gamma_\Pi = < 0.48 GeV$, decay constant $r \equiv [F_\Pi M_\Pi^2 / f_\pi m_\pi^2]^2 = 4.7 \pm 2.8$.
2209.02885
Patrick Huber
Patrick Huber
Testing the Gallium Anomaly
8 pages, 3 figures, version accepted in PRD
null
10.1103/PhysRevD.107.096011
null
hep-ph hep-ex nucl-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the online detection by gallium capture of mono-energetic neutrinos produced by a $^{51}$Cr radioactive source in a scintillation experiment. We find that cerium-doped gadolinium aluminum gallium garnet (GAGG) is a suitable scintillator which contains about 21% of gallium per weight and has a high mass density and light yield. Combined with a highly efficient light detection system this allows tagging of the subsequent germanium decay and thus a clean distinction of gallium capture and elastic neutrino electron scattering events. With 1.5 tons of scintillator and 10 source runs of 3.4MCi, each, we obtain about 760 gallium capture events with a purity of 85% and 680,000 neutrino electron scattering events, where the latter provide a precise normalization independent of any nuclear physics. This configuration would allow to test the gallium anomaly at more than $5\sigma$ in an independent way.
[ { "created": "Wed, 7 Sep 2022 02:09:20 GMT", "version": "v1" }, { "created": "Fri, 9 Sep 2022 20:52:06 GMT", "version": "v2" }, { "created": "Thu, 4 May 2023 00:18:29 GMT", "version": "v3" } ]
2023-05-24
[ [ "Huber", "Patrick", "" ] ]
We study the online detection by gallium capture of mono-energetic neutrinos produced by a $^{51}$Cr radioactive source in a scintillation experiment. We find that cerium-doped gadolinium aluminum gallium garnet (GAGG) is a suitable scintillator which contains about 21% of gallium per weight and has a high mass density and light yield. Combined with a highly efficient light detection system this allows tagging of the subsequent germanium decay and thus a clean distinction of gallium capture and elastic neutrino electron scattering events. With 1.5 tons of scintillator and 10 source runs of 3.4MCi, each, we obtain about 760 gallium capture events with a purity of 85% and 680,000 neutrino electron scattering events, where the latter provide a precise normalization independent of any nuclear physics. This configuration would allow to test the gallium anomaly at more than $5\sigma$ in an independent way.
hep-ph/9905402
J. R. Fleitas
J.Bellandi, J.R.Fleitas, J.Dias de Deus
Leading nucleon and inelasticity in hadron-nucleus interactions
11 pages, 2 figures
J.Phys.G25:1623-1628,1999
10.1088/0954-3899/25/8/306
null
hep-ph
null
We present in this paper a calculation of the average proton-nucleus ine- lasticity. Using an Iterative Leading Particle Model and the Glauber model, we relate the leading particle distribution in nucleon-nucleus interactions with the respective one in nucleon-proton collisions. To describe the leading particle distribution in nucleon-proton collisions, we use the Regge-Mueller formalism. To appear in Journal of Physics G.
[ { "created": "Wed, 19 May 1999 17:02:50 GMT", "version": "v1" } ]
2008-11-26
[ [ "Bellandi", "J.", "" ], [ "Fleitas", "J. R.", "" ], [ "de Deus", "J. Dias", "" ] ]
We present in this paper a calculation of the average proton-nucleus ine- lasticity. Using an Iterative Leading Particle Model and the Glauber model, we relate the leading particle distribution in nucleon-nucleus interactions with the respective one in nucleon-proton collisions. To describe the leading particle distribution in nucleon-proton collisions, we use the Regge-Mueller formalism. To appear in Journal of Physics G.
1307.4224
Markus Pak
M.Pak and L.Ya.Glozman
Effect of Transverse Gluons on Chiral Restoration in Excited Mesons
null
Phys. Rev. D 88, 076010 (2013)
10.1103/PhysRevD.88.076010
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The effect of transverse gluons on the chiral symmetry patterns of excited mesons is studied in a Coulomb gauge QCD model. The linear rising static quark-antiquark potential and the transverse gluon propagator known from lattice studies are input into the model. The non-perturbative quark propagator, which enters the meson bound state equations, is derived from the Dyson--Schwinger equations and a complete set of mesons for general spin quantum number is presented. From analyzing the bound state equations for large spins it is demonstrated, that chiral and axial symmetry are restored. In this limit a complete degeneracy of all multiplets with given spin is observed. The effect of the transverse gluon interaction is shown to vanish rapidly as the spin quantum number is increased. For vanishing dynamical quark mass the expected meson degeneracies are recovered.
[ { "created": "Tue, 16 Jul 2013 09:46:43 GMT", "version": "v1" } ]
2014-03-11
[ [ "Pak", "M.", "" ], [ "Glozman", "L. Ya.", "" ] ]
The effect of transverse gluons on the chiral symmetry patterns of excited mesons is studied in a Coulomb gauge QCD model. The linear rising static quark-antiquark potential and the transverse gluon propagator known from lattice studies are input into the model. The non-perturbative quark propagator, which enters the meson bound state equations, is derived from the Dyson--Schwinger equations and a complete set of mesons for general spin quantum number is presented. From analyzing the bound state equations for large spins it is demonstrated, that chiral and axial symmetry are restored. In this limit a complete degeneracy of all multiplets with given spin is observed. The effect of the transverse gluon interaction is shown to vanish rapidly as the spin quantum number is increased. For vanishing dynamical quark mass the expected meson degeneracies are recovered.
hep-ph/0205225
Spanos Vassilis
A.B. Lahanas, D.V. Nanopoulos and V.C. Spanos
Supersymmetric Dark Matter and Recent Experimental Constraints
8 pages, 3 figures. Presented at DARK 2002: 4th International Heidelberg Conference on Dark Matter in Astro and Particle Physics, Cape Town, South Africa, 4-9 Feb 2002 and at 5th International UCLA Symposium on Dark Matter, Feb 20-22, 2002, Marina del Rey, CA
null
null
null
hep-ph
null
In this talk we discuss the impact of recent experimental information, like the revised bound from E821 Brookhaven experiment on $g_{\mu}-2$ and light Higgs boson mass bound from LEP, in delineating regions of the parameters of the Constrained Minimal Supersymmetric Standard Model which are consistent with the cosmological data. The effect of these to Dark Matter direct searches is also discussed.
[ { "created": "Tue, 21 May 2002 09:00:22 GMT", "version": "v1" } ]
2007-05-23
[ [ "Lahanas", "A. B.", "" ], [ "Nanopoulos", "D. V.", "" ], [ "Spanos", "V. C.", "" ] ]
In this talk we discuss the impact of recent experimental information, like the revised bound from E821 Brookhaven experiment on $g_{\mu}-2$ and light Higgs boson mass bound from LEP, in delineating regions of the parameters of the Constrained Minimal Supersymmetric Standard Model which are consistent with the cosmological data. The effect of these to Dark Matter direct searches is also discussed.
0902.4656
Andre de Gouvea
Andre de Gouvea
Neutrino Masses and Mixing - Theory
Invited Talk at Heavy Quarks and Leptons, Melbourne, 2008, to appear in the proceedings. 6 pages and 3 eps figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this talk I review what we know and don't know about neutrinos, neutrino masses and lepton mixing. I also discuss the importance of the discovery that neutrinos have nonzero masses, and illustrate how little is currently known about the physics behind them.
[ { "created": "Thu, 26 Feb 2009 19:43:27 GMT", "version": "v1" } ]
2009-02-27
[ [ "de Gouvea", "Andre", "" ] ]
In this talk I review what we know and don't know about neutrinos, neutrino masses and lepton mixing. I also discuss the importance of the discovery that neutrinos have nonzero masses, and illustrate how little is currently known about the physics behind them.
hep-ph/0309124
Francesca Rosati
Francesca Rosati
Quintessence and the dark matter abundance
Proceedings of "Marseille 2003 - Where Cosmology and Fundamental Physics meet", 23-26 June 2003, Marseille (France)
null
null
null
hep-ph astro-ph
null
Results of a recent study on how the Quintessence scalar could affect the relic abundance of dark matter particles are presented.
[ { "created": "Thu, 11 Sep 2003 11:23:16 GMT", "version": "v1" } ]
2007-05-23
[ [ "Rosati", "Francesca", "" ] ]
Results of a recent study on how the Quintessence scalar could affect the relic abundance of dark matter particles are presented.
1208.2973
Hye-Sung Lee
Hooman Davoudiasl, Hye-Sung Lee, William J. Marciano
Dark Side of Higgs Diphoton Decays and Muon g-2
Version to appear in PRD
null
10.1103/PhysRevD.86.095009
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose that the LHC hints for a Higgs diphoton excess and the muon g-2 (g_mu-2) discrepancy between theory and experiment may be related by vector-like "leptons" charged under both U(1)_Y hypercharge and a "dark" U(1)_d. Quantum loops of such leptons can enhance the Higgs diphoton rate and also generically lead to U(1)_Y - U(1)_d kinetic mixing. The induced coupling of a light U(1)_d gauge boson Z_d to electric charge can naturally explain the measured g_mu-2. We update Z_d mass and coupling constraints based on comparison of the electron g-2 experiment and theory, and find that explaining g_mu-2 while satisfying other constraints requires Z_d to have a mass ~ 20-100 MeV. We predict new Higgs decay channels gamma Z_d and Z_d Z_d, with rates below the diphoton mode but potentially observable. The boosted Z_d -> e+e- in these decays would mimic a promptly converted photon and could provide a fraction of the apparent diphoton excess. More statistics or a closer inspection of extant data may reveal such events.
[ { "created": "Tue, 14 Aug 2012 20:39:57 GMT", "version": "v1" }, { "created": "Thu, 23 Aug 2012 20:36:52 GMT", "version": "v2" }, { "created": "Wed, 31 Oct 2012 18:36:07 GMT", "version": "v3" } ]
2015-06-11
[ [ "Davoudiasl", "Hooman", "" ], [ "Lee", "Hye-Sung", "" ], [ "Marciano", "William J.", "" ] ]
We propose that the LHC hints for a Higgs diphoton excess and the muon g-2 (g_mu-2) discrepancy between theory and experiment may be related by vector-like "leptons" charged under both U(1)_Y hypercharge and a "dark" U(1)_d. Quantum loops of such leptons can enhance the Higgs diphoton rate and also generically lead to U(1)_Y - U(1)_d kinetic mixing. The induced coupling of a light U(1)_d gauge boson Z_d to electric charge can naturally explain the measured g_mu-2. We update Z_d mass and coupling constraints based on comparison of the electron g-2 experiment and theory, and find that explaining g_mu-2 while satisfying other constraints requires Z_d to have a mass ~ 20-100 MeV. We predict new Higgs decay channels gamma Z_d and Z_d Z_d, with rates below the diphoton mode but potentially observable. The boosted Z_d -> e+e- in these decays would mimic a promptly converted photon and could provide a fraction of the apparent diphoton excess. More statistics or a closer inspection of extant data may reveal such events.
hep-ph/0103086
Veronica Sanz Gonzalez
N. Rius and V. Sanz
Dynamical Symmetry Breaking in Warped Compactifications
16 pages, no figures. v3 : Final version, to be published in Phys. Rev. D
Phys.Rev. D64 (2001) 075006
10.1103/PhysRevD.64.075006
FTUV-01-0308, IFIC/01-1
hep-ph
null
We study dynamical electroweak symmetry breaking in the Randall-Sundrum scenario. We show that one extra dimension is enough to give the correct pattern of electroweak symmetry breaking in a simple model with gauge bosons and the right-handed top quark in the bulk. The top quark mass is also in agreement with experiment. Furthermore, we propose an extended scenario with all Standard Model gauge bosons and fermions propagating in the bulk, which naturally accommodates the fermion mass hierarchies. No new fields or interactions beyond the observed in the Standard Model are required.
[ { "created": "Thu, 8 Mar 2001 16:45:09 GMT", "version": "v1" }, { "created": "Fri, 16 Mar 2001 12:35:53 GMT", "version": "v2" }, { "created": "Fri, 27 Jul 2001 10:31:28 GMT", "version": "v3" } ]
2009-11-07
[ [ "Rius", "N.", "" ], [ "Sanz", "V.", "" ] ]
We study dynamical electroweak symmetry breaking in the Randall-Sundrum scenario. We show that one extra dimension is enough to give the correct pattern of electroweak symmetry breaking in a simple model with gauge bosons and the right-handed top quark in the bulk. The top quark mass is also in agreement with experiment. Furthermore, we propose an extended scenario with all Standard Model gauge bosons and fermions propagating in the bulk, which naturally accommodates the fermion mass hierarchies. No new fields or interactions beyond the observed in the Standard Model are required.
hep-ph/9407219
null
G. Domokos and S. Kovesi-Domokos (Dept. of Physics and Astronomy, Johns Hopkins University, Baltimore, MD)
Semianalytic Cascade Theory
Preprint JHU-TIPAC 940002, 19 pages. E-mail: SKD@JHUP.PHA.JHU.EDU
null
null
null
hep-ph
null
We give a simple, semianalytic theory of the development of the hadronic and neutrino/muon components of a cascade induced by a primary which produces hadrons at the initial interaction. The main purpose of the theory is to allow the user to obtain quick, but reasonably reliable estimates of the longitudinal properties of such cascades developing in a medium, such as a stellar interior, the atmosphere and/or water. As an application, we discuss the possibility of discovering physics beyond the Standard Model by means of neutrino telescopes. Some of those events may have spectacular signatures in neutrino telescopes. [LaTeX, no outside macros needed. 3 figures, available in hard copy or by E-mail as Encapsulated PostScript (EPS) files.]
[ { "created": "Mon, 4 Jul 1994 17:27:46 GMT", "version": "v1" } ]
2009-09-25
[ [ "Domokos", "G.", "", "Dept. of Physics and Astronomy,\n Johns Hopkins University, Baltimore, MD" ], [ "Kovesi-Domokos", "S.", "", "Dept. of Physics and Astronomy,\n Johns Hopkins University, Baltimore, MD" ] ]
We give a simple, semianalytic theory of the development of the hadronic and neutrino/muon components of a cascade induced by a primary which produces hadrons at the initial interaction. The main purpose of the theory is to allow the user to obtain quick, but reasonably reliable estimates of the longitudinal properties of such cascades developing in a medium, such as a stellar interior, the atmosphere and/or water. As an application, we discuss the possibility of discovering physics beyond the Standard Model by means of neutrino telescopes. Some of those events may have spectacular signatures in neutrino telescopes. [LaTeX, no outside macros needed. 3 figures, available in hard copy or by E-mail as Encapsulated PostScript (EPS) files.]
0909.2536
Daniele Binosi
D. Binosi and J. Papavassiliou
Pinch Technique: Theory and Applications
245 pages, 92 figures
Physics Reports, Volume 479, Issues 1-6, August 2009, Pages 1-152
10.1016/j.physrep.2009.05.001
ECT*-09-05
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the theoretical foundations and most important physical applications of the Pinch Technique (PT). This method allows the construction of off-shell Green's functions in non-Abelian gauge theories that are independent of the gauge-fixing parameter and satisfy ghost-free Ward identities. We first present the diagrammatic formulation of the technique in QCD, deriving at one loop the gauge independent gluon self-energy, quark-gluon vertex, and three-gluon vertex, together with their Abelian Ward identities. The generalization to theories with spontaneous symmetry breaking is carried out in detail, and the connection with the optical theorem and the dispersion relations are explained within the electroweak sector of the Standard Model. The equivalence between the PT and the Feynman gauge of the Background Field Method (BFM) is elaborated, and the crucial differences between the two methods are critically scrutinized. The Batalin-Vilkovisky quantization method and the general formalism of algebraic renormalization are introduced, and the all-order generalization of the PT is thoroughly examined. The extension of the PT to the non-perturbative domain of the QCD Schwinger-Dyson equations is presented systematically, and the main advantages of the resulting self-consistent truncation scheme are discussed. A plethora of physical applications relying on the PT are reviewed, such as the definition of gauge-independent off-shell form-factors, the construction of non-Abelian effective charges, the gauge-invariant treatment of resonant transition amplitudes and unstable particles, and the dynamical generation of an effective gluon mass.
[ { "created": "Mon, 14 Sep 2009 12:58:48 GMT", "version": "v1" } ]
2009-09-15
[ [ "Binosi", "D.", "" ], [ "Papavassiliou", "J.", "" ] ]
We review the theoretical foundations and most important physical applications of the Pinch Technique (PT). This method allows the construction of off-shell Green's functions in non-Abelian gauge theories that are independent of the gauge-fixing parameter and satisfy ghost-free Ward identities. We first present the diagrammatic formulation of the technique in QCD, deriving at one loop the gauge independent gluon self-energy, quark-gluon vertex, and three-gluon vertex, together with their Abelian Ward identities. The generalization to theories with spontaneous symmetry breaking is carried out in detail, and the connection with the optical theorem and the dispersion relations are explained within the electroweak sector of the Standard Model. The equivalence between the PT and the Feynman gauge of the Background Field Method (BFM) is elaborated, and the crucial differences between the two methods are critically scrutinized. The Batalin-Vilkovisky quantization method and the general formalism of algebraic renormalization are introduced, and the all-order generalization of the PT is thoroughly examined. The extension of the PT to the non-perturbative domain of the QCD Schwinger-Dyson equations is presented systematically, and the main advantages of the resulting self-consistent truncation scheme are discussed. A plethora of physical applications relying on the PT are reviewed, such as the definition of gauge-independent off-shell form-factors, the construction of non-Abelian effective charges, the gauge-invariant treatment of resonant transition amplitudes and unstable particles, and the dynamical generation of an effective gluon mass.
hep-ph/0009166
Krishnendu Mukherjee
Krishnendu Mukherjee
Jet rates in the hard scattering process at finite temperature
13 pages, LaTeX, axodraw.sty, 2 postscript figures
null
null
TIFR/TH/00-51
hep-ph
null
We compute the cross-section of the hadronic jets arising from the quark antiquark pair which are produced from a hard photons (of 4-momentum $q$) in the plasma, predominantly consisting of thermalised quarks and gluons. The quark antiquark pair is hard and scattered off the heat bath to form jets, while the gluons being soft get thermalised in the heat bath. The infrared divergences cancel in the observable cross-section to $\alpha_s$ order, which includes the process of emission and absorption of real gluons. Since the massless quark antiquark pair is hard the Compton scattering processes are absent in the heat bath and it renders an uncancelled collinear divergent piece in the cross-section. We regularize it by eliminating the collinear region from the phase space and write it in terms of jet parameters. The temperature dependent part of the jet cross-section is regular at large ${\sqrt{q^2}\over T}$ and vanishes when ${\sqrt{q^2}\over T}\to \infty$. Since jets carry the thermal signature of the hot plasma the jet production rate can be used as a thermometer of the heat bath.
[ { "created": "Thu, 14 Sep 2000 09:19:21 GMT", "version": "v1" } ]
2007-05-23
[ [ "Mukherjee", "Krishnendu", "" ] ]
We compute the cross-section of the hadronic jets arising from the quark antiquark pair which are produced from a hard photons (of 4-momentum $q$) in the plasma, predominantly consisting of thermalised quarks and gluons. The quark antiquark pair is hard and scattered off the heat bath to form jets, while the gluons being soft get thermalised in the heat bath. The infrared divergences cancel in the observable cross-section to $\alpha_s$ order, which includes the process of emission and absorption of real gluons. Since the massless quark antiquark pair is hard the Compton scattering processes are absent in the heat bath and it renders an uncancelled collinear divergent piece in the cross-section. We regularize it by eliminating the collinear region from the phase space and write it in terms of jet parameters. The temperature dependent part of the jet cross-section is regular at large ${\sqrt{q^2}\over T}$ and vanishes when ${\sqrt{q^2}\over T}\to \infty$. Since jets carry the thermal signature of the hot plasma the jet production rate can be used as a thermometer of the heat bath.
1607.06934
Stefan H\"oche
Stefan H\"oche, Philipp Maierhoefer, Niccolo Moretti, Stefano Pozzorini, Frank Siegert
Next-to-leading order QCD predictions for top-quark pair production with up to three jets
10 pages, 6 figures, 2 tables
null
10.1140/epjc/s10052-017-4715-y
SLAC-PUB 16696, ZU-TH 24/16, MCNET-16-31, FR-PHENO-2016-012
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present theoretical predictions for the production of top-quark pairs with up to three jets at the next-to leading order in perturbative QCD. The relevant calculations are performed with Sherpa and OpenLoops. To address the issue of scale choices and related uncertainties in the presence of multiple scales, we compare results obtained with the standard scale HT/2 at fixed order and the MINLO procedure. Analyzing various cross sections and distributions for tt+0,1,2,3 jets at the 13 TeV LHC we find a remarkable overall agreement between fixed-order and MINLO results. The differences are typically below the respective factor-two scale variations, suggesting that for all considered jet multiplicities, missing higher-order effects should not exceed the ten percent level.
[ { "created": "Sat, 23 Jul 2016 13:27:02 GMT", "version": "v1" } ]
2017-04-05
[ [ "Höche", "Stefan", "" ], [ "Maierhoefer", "Philipp", "" ], [ "Moretti", "Niccolo", "" ], [ "Pozzorini", "Stefano", "" ], [ "Siegert", "Frank", "" ] ]
We present theoretical predictions for the production of top-quark pairs with up to three jets at the next-to leading order in perturbative QCD. The relevant calculations are performed with Sherpa and OpenLoops. To address the issue of scale choices and related uncertainties in the presence of multiple scales, we compare results obtained with the standard scale HT/2 at fixed order and the MINLO procedure. Analyzing various cross sections and distributions for tt+0,1,2,3 jets at the 13 TeV LHC we find a remarkable overall agreement between fixed-order and MINLO results. The differences are typically below the respective factor-two scale variations, suggesting that for all considered jet multiplicities, missing higher-order effects should not exceed the ten percent level.
hep-ph/0211403
Nobuyuki Sawado
N.Sawado, N.Shiiki and S.Oryu
Search for the quark shell structure using the non-topological soliton model
14 pages, 8 color-figures, 1 table, revtex4. Talk presented at CFIF Fall Workshop 2002 Nuclear Dynamics:From Quarks and Nuclei,held on October 30-November 2,2002, at Instituto Superior T\'{e}cnico, Lisbon, Portugal; to appear in Few-Body Systems Suppl
null
null
null
hep-ph
null
We investigate higher baryon-number states in the Chiral Quark Soliton Model using the rational map ansatz for the background chiral fields. The soliton solutions are obtained self-consistently. We show that the baryon number density has point-like symmetries and the corresponding valence quark spectrum of the lowest energy exhibits approximate four-fold degenerate. Our results indicate the possibility of existence of the shell-like structure in the multi-baryonic system.
[ { "created": "Tue, 26 Nov 2002 11:12:06 GMT", "version": "v1" } ]
2007-05-23
[ [ "Sawado", "N.", "" ], [ "Shiiki", "N.", "" ], [ "Oryu", "S.", "" ] ]
We investigate higher baryon-number states in the Chiral Quark Soliton Model using the rational map ansatz for the background chiral fields. The soliton solutions are obtained self-consistently. We show that the baryon number density has point-like symmetries and the corresponding valence quark spectrum of the lowest energy exhibits approximate four-fold degenerate. Our results indicate the possibility of existence of the shell-like structure in the multi-baryonic system.
hep-ph/9910201
Yuichiro Kiyo
M. Harada, Y. Keum, Y. Kiyo, T. Morozumi, T. Onogi and N. Yamada
Penguins diagrams in Delta I=1/2 rule and \epsilon'/\epsilon with \sigma models
Title has been changed, 19 pages in RevTex, ps figures included, psfig.sty and here.sty are required
Phys.Rev. D62 (2000) 014002
10.1103/PhysRevD.62.014002
HUPD-9913, KEK-TH-643, DPNU-99-27
hep-ph
null
We study the correlation between $\epe$ and $\Delta I=1/2$ rule in the framework of non-linear $\sigma$ model including scalar mesons. The matrix elements of QCD and Electroweak (EW) penguin operators are computed within factorization approximation. Using the matrix elements and changing the scalar meson mass, we find that there is correlation between $\epe$ and $\Delta I=1/2$ amplitude. However, it is difficult to explain both $\epe$ and $\Delta I=1/2$ amplitude simultaneously. In order to be compatible with $\epe$, typically, about half of $\Delta I=1/2$ amplitude can be explained at most. Our result suggests there may be substantial non-factorizable contribution to CP conserving $K \to \pi \pi$ amplitudes.
[ { "created": "Fri, 1 Oct 1999 01:10:12 GMT", "version": "v1" }, { "created": "Fri, 15 Dec 2000 14:36:36 GMT", "version": "v2" } ]
2009-10-31
[ [ "Harada", "M.", "" ], [ "Keum", "Y.", "" ], [ "Kiyo", "Y.", "" ], [ "Morozumi", "T.", "" ], [ "Onogi", "T.", "" ], [ "Yamada", "N.", "" ] ]
We study the correlation between $\epe$ and $\Delta I=1/2$ rule in the framework of non-linear $\sigma$ model including scalar mesons. The matrix elements of QCD and Electroweak (EW) penguin operators are computed within factorization approximation. Using the matrix elements and changing the scalar meson mass, we find that there is correlation between $\epe$ and $\Delta I=1/2$ amplitude. However, it is difficult to explain both $\epe$ and $\Delta I=1/2$ amplitude simultaneously. In order to be compatible with $\epe$, typically, about half of $\Delta I=1/2$ amplitude can be explained at most. Our result suggests there may be substantial non-factorizable contribution to CP conserving $K \to \pi \pi$ amplitudes.
1605.04885
Wen-Jun Li
Wenjun Li and J.N.Ng
Doubly cvharged vector leptons and the Higgs portal
6 pages,3 figures. Five references, motivation,and comments added;update version
Phys. Rev. D 94, 095012 (2016)
10.1103/PhysRevD.94.095012
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Using a bottom up phenomenological approach we constructed a simple doubly charged vector lepton $E^{\pm\pm}$ model for the possible 750 GeV diphoton resonance $\Phi$ at the LHC assuming it to be a scalar particle. Since no stable doubly charged leptons are seen, to facilitate their decays we complete the model by adding a charged SM electroweak scalar $S^\pm$. $\Phi$ is a SM singlet and can be either an inert scalar or a Higgs field. In the inert case more than one vector lepton are required to account for the photon fusion production of the resonance if the model is to remain perturbative. For a Higgssed case $S^\pm$ can assist the production mechanism without using more than one such lepton. We also found that precision measurements constrain the couplings of $E^{\pm\pm}$ and $S^\pm$ to SM particles to be small. This raises the possibility that they can be fairly long lived and can give rise to displaced vertices if produced at the LHC.
[ { "created": "Mon, 16 May 2016 19:46:54 GMT", "version": "v1" }, { "created": "Wed, 22 Jun 2016 06:04:04 GMT", "version": "v2" }, { "created": "Fri, 16 Sep 2016 03:48:48 GMT", "version": "v3" }, { "created": "Fri, 28 Oct 2016 12:39:44 GMT", "version": "v4" } ]
2016-11-15
[ [ "Li", "Wenjun", "" ], [ "Ng", "J. N.", "" ] ]
Using a bottom up phenomenological approach we constructed a simple doubly charged vector lepton $E^{\pm\pm}$ model for the possible 750 GeV diphoton resonance $\Phi$ at the LHC assuming it to be a scalar particle. Since no stable doubly charged leptons are seen, to facilitate their decays we complete the model by adding a charged SM electroweak scalar $S^\pm$. $\Phi$ is a SM singlet and can be either an inert scalar or a Higgs field. In the inert case more than one vector lepton are required to account for the photon fusion production of the resonance if the model is to remain perturbative. For a Higgssed case $S^\pm$ can assist the production mechanism without using more than one such lepton. We also found that precision measurements constrain the couplings of $E^{\pm\pm}$ and $S^\pm$ to SM particles to be small. This raises the possibility that they can be fairly long lived and can give rise to displaced vertices if produced at the LHC.
hep-ph/0007320
Oscar Vives
A. Masiero and O. Vives (SISSA-ISAS and INFN, Trieste)
Kaon vs. Bottom: Where to look for a general MSSM?
Comment on BaBar-Belle CP asymmetry results, typos corrected and references added. 10 pages, no figures
Phys.Rev.Lett. 86 (2001) 26-29
10.1103/PhysRevLett.86.26
SISSA/69/2000/EP
hep-ph
null
We analyze CP violation and Flavor Changing effects in a general Minimal Supersymmetric extension of the Standard Model with arbitrary non-universal soft-breaking terms. We show that, in this conditions, large FCNC effects are naturally expected in the Kaon system, even in the absence of quark-squark flavor misalignment. On the other hand, the B system is only sensitive to new supersymmetric contributions if the non-universality implies, not only different soft term for the three generations but also the presence of a quark-squark misalignment much larger that the corresponding CKM mixing. The only exception to this rule are processes where the chirality changing contributions proportional to tan beta are leading (for instance b -> s gamma).
[ { "created": "Thu, 27 Jul 2000 19:49:39 GMT", "version": "v1" }, { "created": "Fri, 8 Sep 2000 09:40:22 GMT", "version": "v2" } ]
2009-10-31
[ [ "Masiero", "A.", "", "SISSA-ISAS and INFN, Trieste" ], [ "Vives", "O.", "", "SISSA-ISAS and INFN, Trieste" ] ]
We analyze CP violation and Flavor Changing effects in a general Minimal Supersymmetric extension of the Standard Model with arbitrary non-universal soft-breaking terms. We show that, in this conditions, large FCNC effects are naturally expected in the Kaon system, even in the absence of quark-squark flavor misalignment. On the other hand, the B system is only sensitive to new supersymmetric contributions if the non-universality implies, not only different soft term for the three generations but also the presence of a quark-squark misalignment much larger that the corresponding CKM mixing. The only exception to this rule are processes where the chirality changing contributions proportional to tan beta are leading (for instance b -> s gamma).
hep-ph/9705396
Chuan Wang Luo
A.N.Kamal and C.W.Luo
Final-State Interactions in Heavy Quark Decays
11 pages, Revtex, 1 eps-figure
null
null
Alberta-Thy-08-97
hep-ph
null
We study the role played by the final-state interactions (fsi) in heavy quark decays using Pomeron and Regge exchanges to describe high energy scattering. At center of mass energy $\sqrt{s}\sim 5GeV $, Pomeron dominance does not apply. We study the behavior of the decay amplitudes as $\sqrt{s} $ is varied close to the B mass. We also investigate the behavior of the decay amplitude as $\sqrt{s}\to \infty $. Our conclusion is that the decay amplitudes approach a real value asymptotically.
[ { "created": "Thu, 22 May 1997 18:39:10 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kamal", "A. N.", "" ], [ "Luo", "C. W.", "" ] ]
We study the role played by the final-state interactions (fsi) in heavy quark decays using Pomeron and Regge exchanges to describe high energy scattering. At center of mass energy $\sqrt{s}\sim 5GeV $, Pomeron dominance does not apply. We study the behavior of the decay amplitudes as $\sqrt{s} $ is varied close to the B mass. We also investigate the behavior of the decay amplitude as $\sqrt{s}\to \infty $. Our conclusion is that the decay amplitudes approach a real value asymptotically.
0805.3653
Christopher Thomas
C. E. Thomas, F. E. Close
Is X(3872) a molecule?
15 pages, 3 figures
Phys.Rev.D78:034007,2008
10.1103/PhysRevD.78.034007
OUTP-08-08P
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that the literature on pion exchange between charm and bottom mesons is inconsistent. We derive the formalism explicitly, expose differences between papers in the literature and clarify the implications. We show that the X(3872) can be a bound state but that results are very sensitive to a poorly constrained parameter. We confirm that bound states in the B Bbar sector are possible. The circumstances whereby exotic combinations can bind with cc or bb quantum numbers are explored.
[ { "created": "Fri, 23 May 2008 15:28:47 GMT", "version": "v1" } ]
2008-11-26
[ [ "Thomas", "C. E.", "" ], [ "Close", "F. E.", "" ] ]
We show that the literature on pion exchange between charm and bottom mesons is inconsistent. We derive the formalism explicitly, expose differences between papers in the literature and clarify the implications. We show that the X(3872) can be a bound state but that results are very sensitive to a poorly constrained parameter. We confirm that bound states in the B Bbar sector are possible. The circumstances whereby exotic combinations can bind with cc or bb quantum numbers are explored.
hep-ph/0407089
Johannes Bluemlein
J. Bl\"umlein, H. B\"ottcher, and A. Guffanti
Non-Singlet QCD Analysis of the Structure Function F_2 in 3-Loops
1 Latex file, 1 style file, 2 figures Current World average on alpha_s added
null
10.1016/j.nuclphysbps.2004.09.059
DESY 04-113, SFB/CPP-04-026
hep-ph hep-ex
null
First results of a non--singlet QCD analysis of the structure function $F_2(x,Q^2)$ in 3--loop order based on the non--singlet world data are presented. Correlated errors are determined and their propagation through the evolution equations is performed analytically. The value for $\alpha_s(M_Z)$ is determined to be $0.1135 +/- 0.0023/0.0026$ compatible with results from other QCD analyses. Low moments for $u_v(x)$, $d_v(x)$ and $u_v(x) - d_v(x)$ with correlated errors are calculated which may be compared with results from lattice simulations.
[ { "created": "Wed, 7 Jul 2004 15:58:11 GMT", "version": "v1" }, { "created": "Fri, 9 Jul 2004 06:29:18 GMT", "version": "v2" } ]
2009-11-10
[ [ "Blümlein", "J.", "" ], [ "Böttcher", "H.", "" ], [ "Guffanti", "A.", "" ] ]
First results of a non--singlet QCD analysis of the structure function $F_2(x,Q^2)$ in 3--loop order based on the non--singlet world data are presented. Correlated errors are determined and their propagation through the evolution equations is performed analytically. The value for $\alpha_s(M_Z)$ is determined to be $0.1135 +/- 0.0023/0.0026$ compatible with results from other QCD analyses. Low moments for $u_v(x)$, $d_v(x)$ and $u_v(x) - d_v(x)$ with correlated errors are calculated which may be compared with results from lattice simulations.