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hep-ph/9407205
Rohini Godbole
Rohini M. Godbole
Photon structure and the $\mu$ puzzle
Latex, 15 pages, 7 figures (available by p-mail) equation.sty required, added at the end of the script. BU-TH-94/1
null
null
null
hep-ph
null
In this talk I first briefly explain the puzzle presented by the high muon content observed in air-showers which point to the ultra high-energy $\gamma$ sources like the HER-X-1. Since it had been suggested that a possible explanation of the puzzle might come from the effects of the hadronic structure of the photon, I briefly explain the concept of photon structure function and comment on the uncertainties in the predictions of the \sigtot. Then I show that while the current experiments at the \eplem\ (TRISTAN and LEP) and $ep$ (HERA) colliders have seen clear evidence for the hadronic structure of the photon, the observed muon excess in the air shower experiments, if confirmed by other experiments to be at the same high level, can not be explained in terms of the photon structure function.
[ { "created": "Sat, 2 Jul 1994 01:08:22 GMT", "version": "v1" } ]
2009-09-25
[ [ "Godbole", "Rohini M.", "" ] ]
In this talk I first briefly explain the puzzle presented by the high muon content observed in air-showers which point to the ultra high-energy $\gamma$ sources like the HER-X-1. Since it had been suggested that a possible explanation of the puzzle might come from the effects of the hadronic structure of the photon, I briefly explain the concept of photon structure function and comment on the uncertainties in the predictions of the \sigtot. Then I show that while the current experiments at the \eplem\ (TRISTAN and LEP) and $ep$ (HERA) colliders have seen clear evidence for the hadronic structure of the photon, the observed muon excess in the air shower experiments, if confirmed by other experiments to be at the same high level, can not be explained in terms of the photon structure function.
hep-ph/0408168
Igor Kondrashuk
Kyungsik Kang and Igor Kondrashuk
Semiclassical scattering amplitudes of dressed gravitons
11 pages, no figures
null
null
Brown-HET-1408, USM-TH-158
hep-ph
null
We consider effective action for the Einstein gravity and show that dressed mean fields are actual variables of the effective action. Kernels of this effective action expressed in terms of dressed effective fields are constituent parts of scattering amplitudes for gravitons. Possible applications to the graviton scattering and black hole formation are discussed at the semiclassical level. In particular, we consider graviton scattering in four dimensions based on the Lipatov effective action for quantum gravity, shock waves of particles moving on the brane in Randall-Sundrum scenario with fifth extra dimension, and Giddings' estimation of Froissart bound.
[ { "created": "Sat, 14 Aug 2004 23:31:23 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kang", "Kyungsik", "" ], [ "Kondrashuk", "Igor", "" ] ]
We consider effective action for the Einstein gravity and show that dressed mean fields are actual variables of the effective action. Kernels of this effective action expressed in terms of dressed effective fields are constituent parts of scattering amplitudes for gravitons. Possible applications to the graviton scattering and black hole formation are discussed at the semiclassical level. In particular, we consider graviton scattering in four dimensions based on the Lipatov effective action for quantum gravity, shock waves of particles moving on the brane in Randall-Sundrum scenario with fifth extra dimension, and Giddings' estimation of Froissart bound.
1903.04637
Maxim Laletin
Maxim Laletin and Jean-Ren\'e Cudell
Strongly interacting dark matter and the DAMA signal
19 pages, 11 figures
JCAP 07 (2019) 010
10.1088/1475-7516/2019/07/010
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that models of strongly interacting (SIMP) dark matter built to reproduce the DAMA signal actually cannot account for its time dependence. We discuss the constraints on this type of models coming from direct detection experiments and study the propagation of thermalised dark matter particles in the ground for the allowed values of the parameters. We consider a simple 1D diffusion and a more detailed 3D diffusion. In both cases the predicted signal has either the wrong phase of the annual modulation or a much larger amplitude of the diurnal modulation.
[ { "created": "Mon, 11 Mar 2019 22:37:20 GMT", "version": "v1" }, { "created": "Thu, 4 Jul 2019 14:57:49 GMT", "version": "v2" } ]
2019-07-05
[ [ "Laletin", "Maxim", "" ], [ "Cudell", "Jean-René", "" ] ]
We show that models of strongly interacting (SIMP) dark matter built to reproduce the DAMA signal actually cannot account for its time dependence. We discuss the constraints on this type of models coming from direct detection experiments and study the propagation of thermalised dark matter particles in the ground for the allowed values of the parameters. We consider a simple 1D diffusion and a more detailed 3D diffusion. In both cases the predicted signal has either the wrong phase of the annual modulation or a much larger amplitude of the diurnal modulation.
hep-ph/9507362
Ed Stoeffhaas
F. Halzen and T. Stanev
Gamma Ray Astronomy with Underground Detectors
Standard Latex, 8 pages, no figures. Compressed postscript version at http://phenom.physics.wisc.edu/pub/preprints/1995/madph-95-901.ps.Z or at ftp://phenom.physics.wisc.edu/pub/preprints/1995/madph-95-901.ps.Z
null
null
madph-95-901
hep-ph astro-ph
null
Underground detectors measure the directions of up-coming muons of neutrino origin. They can also observe down-going muons made by gamma rays in the Earth's atmosphere. Although gamma ray showers are muon-poor, they produce a sufficient number of muons to detect the sources observed by GeV and TeV telescopes. With a threshold higher by one hundred and a probability of muon production of about $1\%$ for the shallower AMANDA and Lake Baikal detectors, these instruments can, for a typical GRO source, match the detection efficiency of a GeV satellite detector since their effective area is larger by a factor $10^4$. The muons must have enough energy for accurate reconstruction of their direction. Very energetic muons on the other hand are rare because they are only produced by higher energy gamma rays whose flux is suppressed by the decreasing flux at the source and by absorption on interstellar light. We show that there is a window of opportunity for muon astronomy in the 100~GeV energy region which nicely matches the threshold energies of the AMANDA and Lake Baikal detectors.
[ { "created": "Thu, 20 Jul 1995 21:19:21 GMT", "version": "v1" } ]
2007-05-23
[ [ "Halzen", "F.", "" ], [ "Stanev", "T.", "" ] ]
Underground detectors measure the directions of up-coming muons of neutrino origin. They can also observe down-going muons made by gamma rays in the Earth's atmosphere. Although gamma ray showers are muon-poor, they produce a sufficient number of muons to detect the sources observed by GeV and TeV telescopes. With a threshold higher by one hundred and a probability of muon production of about $1\%$ for the shallower AMANDA and Lake Baikal detectors, these instruments can, for a typical GRO source, match the detection efficiency of a GeV satellite detector since their effective area is larger by a factor $10^4$. The muons must have enough energy for accurate reconstruction of their direction. Very energetic muons on the other hand are rare because they are only produced by higher energy gamma rays whose flux is suppressed by the decreasing flux at the source and by absorption on interstellar light. We show that there is a window of opportunity for muon astronomy in the 100~GeV energy region which nicely matches the threshold energies of the AMANDA and Lake Baikal detectors.
hep-ph/9810326
Dubovsky
S.L.Dubovsky and D.S.Gorbunov
Low $\tan{\beta}$ in the extended Minimal Gauge Mediated Model
Talk presented at the 10th International Seminar ``Quarks-98'', Suzdal, Russia, May 18-24; to appear in the Proceedings
null
null
null
hep-ph
null
We consider the Minimal Gauge Mediated Model (MGMM) with either fundamental or antisymmetric messenger multiplets and study consequences of messenger-matter mixing. It is shown that constraints on relevant coupling constants and mixing parameters coming from the existing experimental limits on lepton flavor violation and FCNC processes allow a wide range of $\tan\beta$ in MGMM with mixing.
[ { "created": "Mon, 12 Oct 1998 14:13:40 GMT", "version": "v1" } ]
2007-05-23
[ [ "Dubovsky", "S. L.", "" ], [ "Gorbunov", "D. S.", "" ] ]
We consider the Minimal Gauge Mediated Model (MGMM) with either fundamental or antisymmetric messenger multiplets and study consequences of messenger-matter mixing. It is shown that constraints on relevant coupling constants and mixing parameters coming from the existing experimental limits on lepton flavor violation and FCNC processes allow a wide range of $\tan\beta$ in MGMM with mixing.
1207.5779
Mathias Ritzmann
Aude Gehrmann-De Ridder, Thomas Gehrmann, Mathias Ritzmann
Antenna subtraction at NNLO with hadronic initial states: double real initial-initial configurations
38 pages; a FORM file with the integrated antennae is included with this submission. arXiv admin note: text overlap with arXiv:1011.6631, arXiv:1107.4037
null
10.1007/JHEP10(2012)047
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The antenna subtraction method handles real radiation contributions in higher order corrections to jet observables. The method is based on antenna functions, which encapsulate all unresolved radiation between a pair of hard radiator partons. To apply this method to compute hadron collider observables, initial-initial antenna functions with both radiators in the initial state are required in unintegrated and integrated forms. In view of extending the antenna subtraction method to next-to-next-to-leading order (NNLO) calculations at hadron colliders, we derive the full set of initial-initial double real radiation antenna functions in integrated form.
[ { "created": "Tue, 24 Jul 2012 19:28:46 GMT", "version": "v1" } ]
2015-06-05
[ [ "Ridder", "Aude Gehrmann-De", "" ], [ "Gehrmann", "Thomas", "" ], [ "Ritzmann", "Mathias", "" ] ]
The antenna subtraction method handles real radiation contributions in higher order corrections to jet observables. The method is based on antenna functions, which encapsulate all unresolved radiation between a pair of hard radiator partons. To apply this method to compute hadron collider observables, initial-initial antenna functions with both radiators in the initial state are required in unintegrated and integrated forms. In view of extending the antenna subtraction method to next-to-next-to-leading order (NNLO) calculations at hadron colliders, we derive the full set of initial-initial double real radiation antenna functions in integrated form.
hep-ph/9707377
Robert Kaminski
R. Kaminski, L. Lesniak (Institute of Nuclear Physics in Cracow, Poland) and B. Loiseau (Institut de Physique Nucleaire at Orsay and LPTPE Universite P. & M. Curie in Paris, France)
Three channel model of meson-meson scattering and scalar meson spectroscopy
10 Latex pages + 6 postscript figures
Phys.Lett.B413:130-136,1997
10.1016/S0370-2693(97)01090-3
null
hep-ph
null
New solutions on the scalar -- isoscalar $\pi\pi$ phase shifts are analysed together with previous $K\bar{K}$ results using a separable potential model of three coupled channels ($\pi\pi$, $K\bar{K}$ and an effective $2\pi 2\pi$ system). Model parameters are fitted to two sets of solutions obtained in a recent analysis of the CERN-Cracow-Munich measurements of the $\pi^- p_{\uparrow} \to \pi^+ \pi^- n$ reaction on a polarized target. A relatively narrow (90 -- 180 MeV) scalar resonance $f_0(1400-1460)$ is found, in contrast to a much broader ($\Gamma \approx 500$ MeV) state emerging from the analysis of previous unpolarized target data.
[ { "created": "Thu, 17 Jul 1997 15:38:19 GMT", "version": "v1" } ]
2008-11-26
[ [ "Kaminski", "R.", "", "Institute of Nuclear Physics in Cracow,\n Poland" ], [ "Lesniak", "L.", "", "Institute of Nuclear Physics in Cracow,\n Poland" ], [ "Loiseau", "B.", "", "Institut de Physique Nucleaire at Orsay and LPTPE\n Universite P. & M. Curie in Paris, France" ] ]
New solutions on the scalar -- isoscalar $\pi\pi$ phase shifts are analysed together with previous $K\bar{K}$ results using a separable potential model of three coupled channels ($\pi\pi$, $K\bar{K}$ and an effective $2\pi 2\pi$ system). Model parameters are fitted to two sets of solutions obtained in a recent analysis of the CERN-Cracow-Munich measurements of the $\pi^- p_{\uparrow} \to \pi^+ \pi^- n$ reaction on a polarized target. A relatively narrow (90 -- 180 MeV) scalar resonance $f_0(1400-1460)$ is found, in contrast to a much broader ($\Gamma \approx 500$ MeV) state emerging from the analysis of previous unpolarized target data.
hep-ph/0110074
Mustafa Savci
T. M. aliev, A. Ozpineci, M. Savci
The (Sigma_Q-Lambda_Q) transition magnetic moments in light cone QCD sum rules
15 pp, 6 figures (postscript formatted), LaTex formatted
Phys.Rev. D65 (2002) 096004
10.1103/PhysRevD.65.096004
metu-phys-hep-ph-01-33
hep-ph
null
Using the general form of (Sigma_Q) and (Lambda_Q) (Q=b or c) currents, (Sigma_Q-Lambda_Q) transition magnetic moments are calculated in framework of the light cone QCD sum rules method. In this approach nonperturbative effects are described by the photon wave functions and only two-particle photon wave functions are taken into account. Our predictions on transition magnetic moments are (mu_{Sigma_c Lambda_c} = - (1.5 pm 0.4) mu_N) and (mu_{Sigma_b Lambda_b} = - (1.6 pm 0.4) mu_N). A comparison of our results with the ones existing in the literature is given.
[ { "created": "Thu, 4 Oct 2001 18:20:36 GMT", "version": "v1" }, { "created": "Mon, 3 Mar 2003 17:40:26 GMT", "version": "v2" } ]
2009-11-07
[ [ "aliev", "T. M.", "" ], [ "Ozpineci", "A.", "" ], [ "Savci", "M.", "" ] ]
Using the general form of (Sigma_Q) and (Lambda_Q) (Q=b or c) currents, (Sigma_Q-Lambda_Q) transition magnetic moments are calculated in framework of the light cone QCD sum rules method. In this approach nonperturbative effects are described by the photon wave functions and only two-particle photon wave functions are taken into account. Our predictions on transition magnetic moments are (mu_{Sigma_c Lambda_c} = - (1.5 pm 0.4) mu_N) and (mu_{Sigma_b Lambda_b} = - (1.6 pm 0.4) mu_N). A comparison of our results with the ones existing in the literature is given.
1201.3349
Qi Wang
Qi Wang and An Min Wang
Chiral Symmetry Breaking in the Dynamical Soft-Wall Model
4 pages
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper a model incorporating chiral symmetry breaking and dynamical soft-wall AdS/QCD is established. The AdS/QCD background is introduced dynamically as suggested by Wayne de Paula etc al and chiral symmetry breaking is discussed by using a bulk scalar field including a cubic term. The mass spectrum of scalar, vector and axial vector mesons are obtained and a comparison with experimental data is presented.
[ { "created": "Mon, 16 Jan 2012 19:52:29 GMT", "version": "v1" } ]
2012-01-17
[ [ "Wang", "Qi", "" ], [ "Wang", "An Min", "" ] ]
In this paper a model incorporating chiral symmetry breaking and dynamical soft-wall AdS/QCD is established. The AdS/QCD background is introduced dynamically as suggested by Wayne de Paula etc al and chiral symmetry breaking is discussed by using a bulk scalar field including a cubic term. The mass spectrum of scalar, vector and axial vector mesons are obtained and a comparison with experimental data is presented.
1312.4262
Shao-Hsuan Chiu
S. H. Chiu, Chu-Ching Huang, and Kwang-Chang Lai
Signatures of the neutrino mass hierarchy in supernova neutrinos
15 pages, 9 figures
Prog. Theor. Exp. Phys. 2015, 063B01
10.1093/ptep/ptv079
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The undetermined neutrino mass hierarchy may leave an observable imprint on the neutrino fluxes from a core-collapse supernova (SN). The interpretation of the observables, however, is subject to the uncertain SN models and the flavor conversion mechanism of neutrinos in a SN. We attempt to propose a qualitative interpretation of the expected neutrino events at terrestrial detectors, focusing on the accretion phase of the neutrino burst. The flavor conversions due to neutrino self-interaction, the MSW effect, and the Earth regeneration effect are incorporated in the calculation. It leads to several distinct scenarios that are identified by the neutrino mass hierarchies and the collective flavor transitions. Consequences resulting from the variation of incident angles and SN models are also discussed.
[ { "created": "Mon, 16 Dec 2013 08:19:37 GMT", "version": "v1" }, { "created": "Mon, 7 Apr 2014 02:32:24 GMT", "version": "v2" }, { "created": "Mon, 11 May 2015 08:46:20 GMT", "version": "v3" }, { "created": "Wed, 17 Jun 2015 06:19:38 GMT", "version": "v4" } ]
2015-06-18
[ [ "Chiu", "S. H.", "" ], [ "Huang", "Chu-Ching", "" ], [ "Lai", "Kwang-Chang", "" ] ]
The undetermined neutrino mass hierarchy may leave an observable imprint on the neutrino fluxes from a core-collapse supernova (SN). The interpretation of the observables, however, is subject to the uncertain SN models and the flavor conversion mechanism of neutrinos in a SN. We attempt to propose a qualitative interpretation of the expected neutrino events at terrestrial detectors, focusing on the accretion phase of the neutrino burst. The flavor conversions due to neutrino self-interaction, the MSW effect, and the Earth regeneration effect are incorporated in the calculation. It leads to several distinct scenarios that are identified by the neutrino mass hierarchies and the collective flavor transitions. Consequences resulting from the variation of incident angles and SN models are also discussed.
hep-ph/9912267
Dam Thanh Son
D.T. Son (Columbia University)
Hydrodynamics of nuclear matter in the chiral limit
9 pages; small improvements. Version published in PRL
Phys.Rev.Lett. 84 (2000) 3771-3774
10.1103/PhysRevLett.84.3771
CU-TP-960
hep-ph cond-mat.soft nlin.CD nucl-th physics.flu-dyn
null
Using the Poisson bracket method, we construct the hydrodynamics of nuclear matter in the chiral limit, which describes the dynamics of all low-energy degrees of freedom, including the fluid-dynamical and pionic ones. The hydrodynamic equations contain, beside five Euler equations of relativistic fluid dynamics, Nf^2-1 second order equations describing propagating pions and Nf^2-1 first order equations describing the advection of the baryonic vector isospin charges. We present hydrodynamic arguments showing that the pion velocity vanishes at the second order phase transition at Nf=2.
[ { "created": "Wed, 8 Dec 1999 00:12:50 GMT", "version": "v1" }, { "created": "Fri, 21 Apr 2000 15:40:32 GMT", "version": "v2" } ]
2007-05-23
[ [ "Son", "D. T.", "", "Columbia University" ] ]
Using the Poisson bracket method, we construct the hydrodynamics of nuclear matter in the chiral limit, which describes the dynamics of all low-energy degrees of freedom, including the fluid-dynamical and pionic ones. The hydrodynamic equations contain, beside five Euler equations of relativistic fluid dynamics, Nf^2-1 second order equations describing propagating pions and Nf^2-1 first order equations describing the advection of the baryonic vector isospin charges. We present hydrodynamic arguments showing that the pion velocity vanishes at the second order phase transition at Nf=2.
1703.07750
Margarete Muhlleitner
M. Muhlleitner, M. Sampaio, R. Santos, J. Wittbrodt
Phenomenological Comparison of Models with Extended Higgs Sectors
Matches journal version; figures for NMSSM changed; conclusions unchanged
null
10.1007/JHEP08(2017)132
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Beyond the Standard Model (SM) extensions usually include extended Higgs sectors. Models with singlet or doublet fields are the simplest ones that are compatible with the $\rho$ parameter constraint. The discovery of new non-SM Higgs bosons and the identification of the underlying model requires dedicated Higgs properties analyses. In this paper, we compare several Higgs sectors featuring 3 CP-even neutral Higgs bosons that are also motivated by their simplicity and their capability to solve some of the flaws of the SM. They are: the SM extended by a complex singlet field (CxSM), the singlet extension of the 2-Higgs-Doublet Model (N2HDM), and the Next-to-Minimal Supersymmetric SM extension (NMSSM). In addition, we analyse the CP-violating 2-Higgs-Doublet Model (C2HDM), which provides 3 neutral Higgs bosons with a pseudoscalar admixture. This allows us to compare the effects of singlet and pseudoscalar admixtures. Through dedicated scans of the allowed parameter space of the models, we analyse the phenomenologically viable scenarios from the view point of the SM-like Higgs boson and of the signal rates of the non-SM-like Higgs bosons to be found. In particular, we analyse the effect of singlet/pseudoscalar admixture, and the potential to differentiate these models in the near future. This is supported by a study of couplings sums of the Higgs bosons to massive gauge bosons and to fermions, where we identify features that allow us to distinguish the models, in particular when only part of the Higgs spectrum is discovered. Our results can be taken as guidelines for future LHC data analyses, by the ATLAS and CMS experiments, to identify specific benchmark points aimed at revealing the underlying model.
[ { "created": "Wed, 22 Mar 2017 17:12:03 GMT", "version": "v1" }, { "created": "Tue, 3 Oct 2017 13:43:53 GMT", "version": "v2" } ]
2017-10-04
[ [ "Muhlleitner", "M.", "" ], [ "Sampaio", "M.", "" ], [ "Santos", "R.", "" ], [ "Wittbrodt", "J.", "" ] ]
Beyond the Standard Model (SM) extensions usually include extended Higgs sectors. Models with singlet or doublet fields are the simplest ones that are compatible with the $\rho$ parameter constraint. The discovery of new non-SM Higgs bosons and the identification of the underlying model requires dedicated Higgs properties analyses. In this paper, we compare several Higgs sectors featuring 3 CP-even neutral Higgs bosons that are also motivated by their simplicity and their capability to solve some of the flaws of the SM. They are: the SM extended by a complex singlet field (CxSM), the singlet extension of the 2-Higgs-Doublet Model (N2HDM), and the Next-to-Minimal Supersymmetric SM extension (NMSSM). In addition, we analyse the CP-violating 2-Higgs-Doublet Model (C2HDM), which provides 3 neutral Higgs bosons with a pseudoscalar admixture. This allows us to compare the effects of singlet and pseudoscalar admixtures. Through dedicated scans of the allowed parameter space of the models, we analyse the phenomenologically viable scenarios from the view point of the SM-like Higgs boson and of the signal rates of the non-SM-like Higgs bosons to be found. In particular, we analyse the effect of singlet/pseudoscalar admixture, and the potential to differentiate these models in the near future. This is supported by a study of couplings sums of the Higgs bosons to massive gauge bosons and to fermions, where we identify features that allow us to distinguish the models, in particular when only part of the Higgs spectrum is discovered. Our results can be taken as guidelines for future LHC data analyses, by the ATLAS and CMS experiments, to identify specific benchmark points aimed at revealing the underlying model.
hep-ph/9408329
null
Marco Aurelio Diaz
Is a Light Gluino Compatible with N=1 Supersymmetry?
15 pages, plain tex, 5 figures not included, VAND-TH-94-13
null
null
null
hep-ph
null
Using the new CLEO bound on the branching ratio of the decay mode $b\longrightarrow s\gamma$ given by $1\times10^{-4}< B(b\longrightarrow s\gamma)<4\times10^{-4}$ at 95\% c.l., and the experimental bounds on the masses of the lightest chargino, the second lightest neutralino, and the light CP-odd Higgs, we find that a light gluino is incompatible with a class of supergravity models defined by $N=1$ supergravity, with a radiatively broken electroweak symmetry group and universality of scalar and gaugino masses at the unification scale. We also find in this scenario strong constraints on the parameter space due to the new CLEO bounds on $B(b\longrightarrow s\gamma)$. Presented in the International Workshop ``SUSY-94'', University of Michigan, Ann Arbor MI, May 14-17, 1994.
[ { "created": "Thu, 18 Aug 1994 22:42:29 GMT", "version": "v1" } ]
2009-09-25
[ [ "Diaz", "Marco Aurelio", "" ] ]
Using the new CLEO bound on the branching ratio of the decay mode $b\longrightarrow s\gamma$ given by $1\times10^{-4}< B(b\longrightarrow s\gamma)<4\times10^{-4}$ at 95\% c.l., and the experimental bounds on the masses of the lightest chargino, the second lightest neutralino, and the light CP-odd Higgs, we find that a light gluino is incompatible with a class of supergravity models defined by $N=1$ supergravity, with a radiatively broken electroweak symmetry group and universality of scalar and gaugino masses at the unification scale. We also find in this scenario strong constraints on the parameter space due to the new CLEO bounds on $B(b\longrightarrow s\gamma)$. Presented in the International Workshop ``SUSY-94'', University of Michigan, Ann Arbor MI, May 14-17, 1994.
2207.07588
Christian Weiss
J. L. Goity, C. Weiss, C. T. Willemyns
Target normal single-spin asymmetry in inclusive electron-nucleon scattering with two-photon exchange: Analysis using $1/N_c$ expansion
7 pages, 2 figures
null
10.1016/j.physletb.2022.137580
JLAB-THY-22-3662
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the target normal single-spin asymmetry caused by two-photon exchange in inclusive electron-nucleon scattering in the resonance region. Our analysis uses the $1/N_c$ expansion of low-energy QCD and combines $N$ and $\Delta$ intermediate and final states using the contracted $SU(4)$ spin-flavor symmetry. The normal spin asymmetry obtained in leading-order accuracy in $1/N_c$ has magnitude $\sim 10^{-2}$ and different sign in $ep$ and $en$ scattering. It can be measured in electron scattering at lab energies $\sim$ 0.5-1.5 GeV and provides a clean probe of two-photon exchange dynamics.
[ { "created": "Fri, 15 Jul 2022 16:37:07 GMT", "version": "v1" } ]
2022-11-23
[ [ "Goity", "J. L.", "" ], [ "Weiss", "C.", "" ], [ "Willemyns", "C. T.", "" ] ]
We calculate the target normal single-spin asymmetry caused by two-photon exchange in inclusive electron-nucleon scattering in the resonance region. Our analysis uses the $1/N_c$ expansion of low-energy QCD and combines $N$ and $\Delta$ intermediate and final states using the contracted $SU(4)$ spin-flavor symmetry. The normal spin asymmetry obtained in leading-order accuracy in $1/N_c$ has magnitude $\sim 10^{-2}$ and different sign in $ep$ and $en$ scattering. It can be measured in electron scattering at lab energies $\sim$ 0.5-1.5 GeV and provides a clean probe of two-photon exchange dynamics.
0910.0212
Vincent Mathieu
V. Mathieu and V. Vento
Pseudoscalar glueball and $\eta-\eta^\prime$ mixing
12 pages, 8 figures
Phys.Rev.D81:034004,2010
10.1103/PhysRevD.81.034004
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We have performed a dynamical analysis of the mixing in the pseudoscalar channel with the goal of understanding the existence and behavior of the pseudoscalar glueball. Our philosophy has not been to predict precise values of the glueball mass but to exploit an adequate effective theory to the point of breaking and to analyze which kind of mechanisms restore compatibility with data. Our study has lead to analytical solutions which allow a clear understanding of the phenomena. The outcome of our calculation leads to a large mass glueball $M_\Theta>2000$ MeV, to a large glue content of the $\eta^\prime$ and to mixing angles in agreement with previous numerical studies.
[ { "created": "Thu, 1 Oct 2009 16:18:10 GMT", "version": "v1" }, { "created": "Thu, 21 Jan 2010 10:49:10 GMT", "version": "v2" } ]
2014-11-20
[ [ "Mathieu", "V.", "" ], [ "Vento", "V.", "" ] ]
We have performed a dynamical analysis of the mixing in the pseudoscalar channel with the goal of understanding the existence and behavior of the pseudoscalar glueball. Our philosophy has not been to predict precise values of the glueball mass but to exploit an adequate effective theory to the point of breaking and to analyze which kind of mechanisms restore compatibility with data. Our study has lead to analytical solutions which allow a clear understanding of the phenomena. The outcome of our calculation leads to a large mass glueball $M_\Theta>2000$ MeV, to a large glue content of the $\eta^\prime$ and to mixing angles in agreement with previous numerical studies.
hep-ph/0310356
Spanos Vassilis
John Ellis, Keith A. Olive, Yudi Santoso, Vassilis C. Spanos
Likelihood Analysis of the CMSSM Parameter Space
25 pages, 33 figures
Phys.Rev.D69:095004,2004
10.1103/PhysRevD.69.095004
CERN-TH/2003-262, UMN-TH-2217/03, TPI-MINN-03/28
hep-ph
null
We present a likelihood analysis of the parameter space of the constrained minimal supersymmetric extension of the Standard Model (CMSSM), in which the input scalar masses m_0 and fermion masses m_{1/2} are each assumed to be universal. We include the full experimental likelihood function from the LEP Higgs search as well as the likelihood from a global precision electroweak fit. We also include the likelihoods for b to s gamma decay and (optionally) g_mu - 2. For each of these inputs, both the experimental and theoretical errors are treated. We include the systematic errors stemming from the uncertainties in m_t and m_b, which are important for delineating the allowed CMSSM parameter space as well as calculating the relic density of supersymmetric particles. We assume that these dominate the cold dark matter density, with a density in the range favoured by WMAP. We display the global likelihood function along cuts in the (m_{1/2}, m_0) planes for tan beta = 10 and both signs of mu, tan beta = 35, mu < 0 and tan beta = 50, mu > 0, which illustrate the relevance of g_mu - 2 and the uncertainty in m_t. We also display likelihood contours in the (m_{1/2}, m_0) planes for these values of tan beta. The likelihood function is generally larger for mu > 0 than for mu < 0, and smaller in the focus-point region than in the bulk and coannihilation regions, but none of these possibilities can yet be excluded.
[ { "created": "Thu, 30 Oct 2003 21:01:59 GMT", "version": "v1" } ]
2009-09-11
[ [ "Ellis", "John", "" ], [ "Olive", "Keith A.", "" ], [ "Santoso", "Yudi", "" ], [ "Spanos", "Vassilis C.", "" ] ]
We present a likelihood analysis of the parameter space of the constrained minimal supersymmetric extension of the Standard Model (CMSSM), in which the input scalar masses m_0 and fermion masses m_{1/2} are each assumed to be universal. We include the full experimental likelihood function from the LEP Higgs search as well as the likelihood from a global precision electroweak fit. We also include the likelihoods for b to s gamma decay and (optionally) g_mu - 2. For each of these inputs, both the experimental and theoretical errors are treated. We include the systematic errors stemming from the uncertainties in m_t and m_b, which are important for delineating the allowed CMSSM parameter space as well as calculating the relic density of supersymmetric particles. We assume that these dominate the cold dark matter density, with a density in the range favoured by WMAP. We display the global likelihood function along cuts in the (m_{1/2}, m_0) planes for tan beta = 10 and both signs of mu, tan beta = 35, mu < 0 and tan beta = 50, mu > 0, which illustrate the relevance of g_mu - 2 and the uncertainty in m_t. We also display likelihood contours in the (m_{1/2}, m_0) planes for these values of tan beta. The likelihood function is generally larger for mu > 0 than for mu < 0, and smaller in the focus-point region than in the bulk and coannihilation regions, but none of these possibilities can yet be excluded.
1201.0576
Michael Christy
M. E. Christy, J. Blumlein, H. Bottcher
Unfolding of target mass contributions from inclusive proton structure function data
6 pages, 2 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We report on the extraction of the target mass contributions to the unpolarized proton structure functions by applying an unfolding procedure to the available world data from charged lepton scattering. The method employed is complementary to recent and future parton distribution function fits including target mass contributions and the results obtained can be utilized to further study perturbative QCD at large Bjorken x and small $Q^2$ . Global fits are performed to both the available $F^2$ and the separated $F_L$ ($F_1$) data which yield excellent descriptions and provides parameterizations of the extracted target mass contributions.
[ { "created": "Tue, 3 Jan 2012 05:49:45 GMT", "version": "v1" }, { "created": "Thu, 12 Jan 2012 15:50:45 GMT", "version": "v2" } ]
2012-01-13
[ [ "Christy", "M. E.", "" ], [ "Blumlein", "J.", "" ], [ "Bottcher", "H.", "" ] ]
We report on the extraction of the target mass contributions to the unpolarized proton structure functions by applying an unfolding procedure to the available world data from charged lepton scattering. The method employed is complementary to recent and future parton distribution function fits including target mass contributions and the results obtained can be utilized to further study perturbative QCD at large Bjorken x and small $Q^2$ . Global fits are performed to both the available $F^2$ and the separated $F_L$ ($F_1$) data which yield excellent descriptions and provides parameterizations of the extracted target mass contributions.
1602.00379
Yue-Liang Wu
Zhen Fang, Dan-Ning Li, Yue-Liang Wu
IR-improved Soft-wall AdS/QCD Model for Baryons
12 pages, 4 tables, 1 figure, to be published in PLB
null
10.1016/j.physletb.2016.01.045
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct an infrared-improved soft-wall AdS/QCD model for baryons by considering the infrared-modified 5D conformal mass and Yukawa coupling of the bulk baryon field. The model is also built by taking into account the parity-doublet pattern for the excited baryons. When taking the bulk vacuum structure of the meson field to be the one obtained consistently in the infrared-improved soft-wall AdS/QCD model for mesons, we arrive at a consistent prediction for the baryon mass spectrum in even and odd parity. The prediction shows a remarkable agreement with the experimental data. We also perform a calculation for the $\rho(a_1)$ meson-nucleon coupling constant and obtain a consistent result in comparison with the experimental data and many other models.
[ { "created": "Mon, 1 Feb 2016 03:33:07 GMT", "version": "v1" } ]
2016-02-17
[ [ "Fang", "Zhen", "" ], [ "Li", "Dan-Ning", "" ], [ "Wu", "Yue-Liang", "" ] ]
We construct an infrared-improved soft-wall AdS/QCD model for baryons by considering the infrared-modified 5D conformal mass and Yukawa coupling of the bulk baryon field. The model is also built by taking into account the parity-doublet pattern for the excited baryons. When taking the bulk vacuum structure of the meson field to be the one obtained consistently in the infrared-improved soft-wall AdS/QCD model for mesons, we arrive at a consistent prediction for the baryon mass spectrum in even and odd parity. The prediction shows a remarkable agreement with the experimental data. We also perform a calculation for the $\rho(a_1)$ meson-nucleon coupling constant and obtain a consistent result in comparison with the experimental data and many other models.
hep-ph/9910381
yves R. Roblin
P.Y. Bertin (1), Y. Roblin (1) and C.E. Hyde-Wright (2) ((1) Universite blaise pascal, Clermont-Ferrand, France (2) Old Dominion University, Norfolk, VA, USA)
The experimental challenge of virtual compton scattering above 8 GeV
23 pages, 17 figures Presented at Nuclear and Particle Physics with CEBAF at Jefferson LAb, 3-10 November 1998, Dubrovnik, Croatia
FizikaB8:207-228,1999
null
PCCF RI 9905
hep-ph
null
We discuss the experimental issues confronting measurements of the Virtual Compton Scattering (VCS) reaction ep->ep gamma with electron beam energies 6-30 GeV. We specifically address the kinematics of Deeply Virtual Compton Scattering (Deep Inelastic Scattering, with coincident detection of the exclusive real photon nearly parallel to the virtual photon direction) and large transverse momentum VCS (High energy VCS of arbitrary Q**2, and the recoil proton emitted with high momentum transverse to the virtual photon direction). We discuss the experimental equipment necessary for these measurements. For the DVCS, we emphasize the importance of the Bethe-Heitler-Compton interference terms that can be measured with the electron-positron (beam charge) asymmetry, and the electron beam helicity asymmetry.
[ { "created": "Mon, 18 Oct 1999 12:17:56 GMT", "version": "v1" } ]
2008-11-26
[ [ "Bertin", "P. Y.", "" ], [ "Roblin", "Y.", "" ], [ "Hyde-Wright", "C. E.", "" ] ]
We discuss the experimental issues confronting measurements of the Virtual Compton Scattering (VCS) reaction ep->ep gamma with electron beam energies 6-30 GeV. We specifically address the kinematics of Deeply Virtual Compton Scattering (Deep Inelastic Scattering, with coincident detection of the exclusive real photon nearly parallel to the virtual photon direction) and large transverse momentum VCS (High energy VCS of arbitrary Q**2, and the recoil proton emitted with high momentum transverse to the virtual photon direction). We discuss the experimental equipment necessary for these measurements. For the DVCS, we emphasize the importance of the Bethe-Heitler-Compton interference terms that can be measured with the electron-positron (beam charge) asymmetry, and the electron beam helicity asymmetry.
0901.1126
J. Lorenzo Diaz-Cruz
J. Lorenzo Diaz-Cruz
Composite Higgs models, Dark Matter and Lambda
Prepared for the Proccedings of the XIII Mexican School of Particles and Fields, Sonora (Mexico), Oct. 2-11, 2008, 8 pages
AIP Conf.Proc.1116:188-195,2009
10.1063/1.3131553
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We suggest that dark matter can be identified with a stable composite fermion X^0, that arises within the holographic AdS/CFT models, where the Higgs boson emerges as a composite pseudo-goldstone boson. The predicted properties of X^0 satisfies the cosmological bounds, with m_X = O(TeV). Thus, through a deeper understanding of the mechanism of electroweak symmetry breaking, a resolution of the Dark Matter enigma is found. Furthermore, by proposing a discrete structure of the Higgs vacuum, one can get a distinct approach to the cosmological constant problem.
[ { "created": "Thu, 8 Jan 2009 20:22:12 GMT", "version": "v1" } ]
2009-04-24
[ [ "Diaz-Cruz", "J. Lorenzo", "" ] ]
We suggest that dark matter can be identified with a stable composite fermion X^0, that arises within the holographic AdS/CFT models, where the Higgs boson emerges as a composite pseudo-goldstone boson. The predicted properties of X^0 satisfies the cosmological bounds, with m_X = O(TeV). Thus, through a deeper understanding of the mechanism of electroweak symmetry breaking, a resolution of the Dark Matter enigma is found. Furthermore, by proposing a discrete structure of the Higgs vacuum, one can get a distinct approach to the cosmological constant problem.
hep-ph/0510215
Pelaez
J.R. Pelaez (Complutense Univ. Madrid)
Consistency checks of different pion-pion scattering data sets using forward dispersion relations
To appear in the Proceedings of the XI. International Conference on Hadron Spectroscopy- HADRON05. Rio de Janeiro. 21st-25th August. 2005
null
10.1063/1.2176569
null
hep-ph
null
We review our evaluation of forward dispersion relations for direct fits to the different, and often conflicting, pion-pion scattering experimental analyses. We find that some of the most commonly used data sets do not satisfy these constraints by several standard deviations. We also provide a consistent pion-pion amplitude by improving a global fit to data with these dispersion relations.
[ { "created": "Mon, 17 Oct 2005 09:37:52 GMT", "version": "v1" } ]
2009-11-11
[ [ "Pelaez", "J. R.", "", "Complutense Univ. Madrid" ] ]
We review our evaluation of forward dispersion relations for direct fits to the different, and often conflicting, pion-pion scattering experimental analyses. We find that some of the most commonly used data sets do not satisfy these constraints by several standard deviations. We also provide a consistent pion-pion amplitude by improving a global fit to data with these dispersion relations.
hep-ph/0702033
Enrico Nardi
Enrico Nardi
Topics in Leptogenesis
8 pages, 2 figures. To appear in the proceedings of 6th Latin American Symposium on High Energy Physics (VI-SILAFAE), Puerto Vallarta, Mexico, November 1-8, 2006
AIPConf.Proc.917:82-89,2007
10.1063/1.2751943
null
hep-ph
null
Baryogenesis via leptogenesis provides an appealing mechanism to explain the observed baryon asymmetry of the Universe. Recent refinements in the understanding of the dynamics of leptogenesis include detailed studies of the effects of lepton flavors and of the role possibly played by the lepton asymmetries generated in the decays of the heavier singlet neutrinos $N_{2,3}$. In this talk I present a short review of these recent developments in the theory of leptogenesis.
[ { "created": "Fri, 2 Feb 2007 17:07:33 GMT", "version": "v1" } ]
2008-11-26
[ [ "Nardi", "Enrico", "" ] ]
Baryogenesis via leptogenesis provides an appealing mechanism to explain the observed baryon asymmetry of the Universe. Recent refinements in the understanding of the dynamics of leptogenesis include detailed studies of the effects of lepton flavors and of the role possibly played by the lepton asymmetries generated in the decays of the heavier singlet neutrinos $N_{2,3}$. In this talk I present a short review of these recent developments in the theory of leptogenesis.
hep-ph/0512242
Yu. A. Simonov
Yu.A.Simonov
Spin-dependent interaction in the deconfined phase of QCD
11 pages,in honor of Adriano Di Giacomo on his 70th birthday, to be published in the Festschrift
null
null
null
hep-ph hep-lat nucl-th
null
Spin-dependent deconfined interaction in the Q\barQ system is derived from the field correlators known from lattice and analytic calculations. As a result hyperfine splitting is found numerically for charmonium, bottomonium and strangeonium in the range T_c<T<2T_c. Spin-orbit interaction due to magnetic correlators (the Thomas term) is able to produce numerous Q\barQ bound states with accumulation point at M=m_Q+m_\barQ. Possible influence of these effects on the thermodynamics of quark-gluon plasma is discussed.
[ { "created": "Mon, 19 Dec 2005 21:43:06 GMT", "version": "v1" } ]
2007-05-23
[ [ "Simonov", "Yu. A.", "" ] ]
Spin-dependent deconfined interaction in the Q\barQ system is derived from the field correlators known from lattice and analytic calculations. As a result hyperfine splitting is found numerically for charmonium, bottomonium and strangeonium in the range T_c<T<2T_c. Spin-orbit interaction due to magnetic correlators (the Thomas term) is able to produce numerous Q\barQ bound states with accumulation point at M=m_Q+m_\barQ. Possible influence of these effects on the thermodynamics of quark-gluon plasma is discussed.
2307.02405
John Andrew Raine
John Andrew Raine, Matthew Leigh, Knut Zoch, Tobias Golling
$\nu^2$-Flows: Fast and improved neutrino reconstruction in multi-neutrino final states with conditional normalizing flows
24 pages, 19 figures, 6 tables
null
10.1103/PhysRevD.109.012005
null
hep-ph cs.LG hep-ex
http://creativecommons.org/licenses/by/4.0/
In this work we introduce $\nu^2$-Flows, an extension of the $\nu$-Flows method to final states containing multiple neutrinos. The architecture can natively scale for all combinations of object types and multiplicities in the final state for any desired neutrino multiplicities. In $t\bar{t}$ dilepton events, the momenta of both neutrinos and correlations between them are reconstructed more accurately than when using the most popular standard analytical techniques, and solutions are found for all events. Inference time is significantly faster than competing methods, and can be reduced further by evaluating in parallel on graphics processing units. We apply $\nu^2$-Flows to $t\bar{t}$ dilepton events and show that the per-bin uncertainties in unfolded distributions is much closer to the limit of performance set by perfect neutrino reconstruction than standard techniques. For the chosen double differential observables $\nu^2$-Flows results in improved statistical precision for each bin by a factor of 1.5 to 2 in comparison to the Neutrino Weighting method and up to a factor of four in comparison to the Ellipse approach.
[ { "created": "Wed, 5 Jul 2023 16:27:33 GMT", "version": "v1" }, { "created": "Thu, 20 Jul 2023 14:10:24 GMT", "version": "v2" }, { "created": "Fri, 15 Dec 2023 13:10:19 GMT", "version": "v3" } ]
2024-01-15
[ [ "Raine", "John Andrew", "" ], [ "Leigh", "Matthew", "" ], [ "Zoch", "Knut", "" ], [ "Golling", "Tobias", "" ] ]
In this work we introduce $\nu^2$-Flows, an extension of the $\nu$-Flows method to final states containing multiple neutrinos. The architecture can natively scale for all combinations of object types and multiplicities in the final state for any desired neutrino multiplicities. In $t\bar{t}$ dilepton events, the momenta of both neutrinos and correlations between them are reconstructed more accurately than when using the most popular standard analytical techniques, and solutions are found for all events. Inference time is significantly faster than competing methods, and can be reduced further by evaluating in parallel on graphics processing units. We apply $\nu^2$-Flows to $t\bar{t}$ dilepton events and show that the per-bin uncertainties in unfolded distributions is much closer to the limit of performance set by perfect neutrino reconstruction than standard techniques. For the chosen double differential observables $\nu^2$-Flows results in improved statistical precision for each bin by a factor of 1.5 to 2 in comparison to the Neutrino Weighting method and up to a factor of four in comparison to the Ellipse approach.
hep-ph/0511014
Tomohito Maeda
Shin Ishida
The ~U(12)-Classification Scheme, Static U(4)-Spin Symmetry for Light-Quarks and "Exotic" Hadrons
Nov 2005. 5pp. To appear in the proceedings of the 11th International Conference on Hadron Spectroscopy (Hadron05), Rio de Janeiro, Brazil, 21-26 Aug 2005
null
10.1063/1.2176532
null
hep-ph
null
Several years ago we have proposed a manifestly covariant $\tilde{U}(12)_{SF}$-classification scheme of hadrons, which maintains the successful $SU(6)_{SF}\otimes O(3)_{L}$ framework in Non-Relativistic Quark Model and is also reconcilable with the mechanism of Spontaneously-Broken Chiral Symmetry in Relativistic Field Theoretical Models. The essential point here is to notice the overlooked freedom of the $SU(2)_{\rho}$-spin for (confined) light quarks, which leads to existence of new type of ``exotic'' hadrons, called ``chiralons'' and to a selection rule, $\rho_{3}$-line rule, on the spectator quark line. A series of puzzling new hadrons recently observed such as X(3872)-meson family and $\Theta (1540)$ and so on are possibly classified mostly as chiralons.
[ { "created": "Wed, 2 Nov 2005 07:14:16 GMT", "version": "v1" }, { "created": "Thu, 3 Nov 2005 16:39:54 GMT", "version": "v2" } ]
2009-11-11
[ [ "Ishida", "Shin", "" ] ]
Several years ago we have proposed a manifestly covariant $\tilde{U}(12)_{SF}$-classification scheme of hadrons, which maintains the successful $SU(6)_{SF}\otimes O(3)_{L}$ framework in Non-Relativistic Quark Model and is also reconcilable with the mechanism of Spontaneously-Broken Chiral Symmetry in Relativistic Field Theoretical Models. The essential point here is to notice the overlooked freedom of the $SU(2)_{\rho}$-spin for (confined) light quarks, which leads to existence of new type of ``exotic'' hadrons, called ``chiralons'' and to a selection rule, $\rho_{3}$-line rule, on the spectator quark line. A series of puzzling new hadrons recently observed such as X(3872)-meson family and $\Theta (1540)$ and so on are possibly classified mostly as chiralons.
hep-ph/0512146
Gunnar Ingelman
Gunnar Ingelman
Hard diffraction -- 20 years later
14 pages, 19 figures. Invited talk at XXII International Symposium on Lepton-Photon Interactions at High Energy, Uppsala, Sweden, June 30-July 5, 2005
Int.J.Mod.Phys. A21 (2006) 1805-1818
10.1142/S0217751X06032770
null
hep-ph
null
The idea of diffractive processes with a hard scale involved, to resolve the underlying parton dynamics, was published 1985 and experimentally verified 1988. Today hard diffraction is an active research field with high-quality data and new theoretical models. The trend from Regge-based pomeron models to QCD-based parton level models has given insights on QCD dynamics involving perturbative gluon exchange mechanisms, including the predicted BFKL-dynamics, as well as novel ideas on non-perturbative colour fields and their interactions. Extrapolations to the LHC include the interesting possibility of diffractive Higgs production.
[ { "created": "Mon, 12 Dec 2005 16:36:19 GMT", "version": "v1" } ]
2009-11-11
[ [ "Ingelman", "Gunnar", "" ] ]
The idea of diffractive processes with a hard scale involved, to resolve the underlying parton dynamics, was published 1985 and experimentally verified 1988. Today hard diffraction is an active research field with high-quality data and new theoretical models. The trend from Regge-based pomeron models to QCD-based parton level models has given insights on QCD dynamics involving perturbative gluon exchange mechanisms, including the predicted BFKL-dynamics, as well as novel ideas on non-perturbative colour fields and their interactions. Extrapolations to the LHC include the interesting possibility of diffractive Higgs production.
hep-ph/0107166
Wayne W. Repko
Ali Abbasabadi and Wayne W. Repko
Photons, neutrinos and optical activity
9 pages, ReVTeX4, 6 figures included
Phys.Rev. D64 (2001) 113007
10.1103/PhysRevD.64.113007
null
hep-ph
null
We compute the one-loop helicity amplitudes for low-energy $\nu\gamma\to\nu\gamma$ scattering and its crossed channels in the standard model with massless neutrinos. In the center of mass, with $\sqrt{s} = 2\omega\ll 2m_e$, the cross sections for these $2\to 2$ channels grow roughly as $\omega^6$. The scattered photons in the elastic channel are circularly polarized and the net value of the polarization is non-zero. We also present a discussion of the optical activity of a sea of neutrinos and estimate the values of its index of refraction and rotary power.
[ { "created": "Sun, 15 Jul 2001 18:08:11 GMT", "version": "v1" } ]
2009-11-07
[ [ "Abbasabadi", "Ali", "" ], [ "Repko", "Wayne W.", "" ] ]
We compute the one-loop helicity amplitudes for low-energy $\nu\gamma\to\nu\gamma$ scattering and its crossed channels in the standard model with massless neutrinos. In the center of mass, with $\sqrt{s} = 2\omega\ll 2m_e$, the cross sections for these $2\to 2$ channels grow roughly as $\omega^6$. The scattered photons in the elastic channel are circularly polarized and the net value of the polarization is non-zero. We also present a discussion of the optical activity of a sea of neutrinos and estimate the values of its index of refraction and rotary power.
1011.4922
Itay Yavin
David Tucker-Smith and Itay Yavin
Muonic hydrogen and MeV forces
4 pages, 3 figures
Phys.Rev.D83:101702,2011
10.1103/PhysRevD.83.101702
null
hep-ph physics.atom-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the possibility that a new interaction between muons and protons is responsible for the discrepancy between the CODATA value of the proton radius and the value deduced from the measurement of the Lamb shift in muonic hydrogen. We show that a new force carrier with roughly MeV mass can account for the observed energy shift as well as the discrepancy in the muon anomalous magnetic moment. However, measurements in other systems constrain the couplings to electrons and neutrons to be suppressed relative to the couplings to muons and protons, which seems challenging from a theoretical point of view. One can nevertheless make predictions for energy shifts in muonic deuterium, muonic helium, and true muonium under the assumption that the new particle couples dominantly to muons and protons.
[ { "created": "Mon, 22 Nov 2010 20:05:37 GMT", "version": "v1" } ]
2011-07-08
[ [ "Tucker-Smith", "David", "" ], [ "Yavin", "Itay", "" ] ]
We explore the possibility that a new interaction between muons and protons is responsible for the discrepancy between the CODATA value of the proton radius and the value deduced from the measurement of the Lamb shift in muonic hydrogen. We show that a new force carrier with roughly MeV mass can account for the observed energy shift as well as the discrepancy in the muon anomalous magnetic moment. However, measurements in other systems constrain the couplings to electrons and neutrons to be suppressed relative to the couplings to muons and protons, which seems challenging from a theoretical point of view. One can nevertheless make predictions for energy shifts in muonic deuterium, muonic helium, and true muonium under the assumption that the new particle couples dominantly to muons and protons.
hep-ph/0209063
Andrea Romanino
G. Cacciapaglia, M. Cirelli, Y. Lin, A. Romanino
Bulk neutrinos and core collapse supernovae
23 pages, 5 eps figures; v2: minor comments and references added, version to appear on Phys.Rev.D
Phys.Rev. D67 (2003) 053001
10.1103/PhysRevD.67.053001
null
hep-ph astro-ph
null
We discuss the phenomenology of neutrino mixing with bulk fermions in the context of supernova physics. The constraints on the parameter space following from the usual energy loss argument can be relaxed by four orders of magnitude due to a feedback mechanism that takes place in a broad region of the parameter space. Such a mechanism also affects the protoneutron star evolution through a non trivial interplay with neutrino diffusion. The consistency with the SN 1987A signal is discussed, as well as the implications for deleptonization, cooling, composition of the neutrino flux and the delayed explosion scenario.
[ { "created": "Thu, 5 Sep 2002 19:36:23 GMT", "version": "v1" }, { "created": "Fri, 7 Mar 2003 15:21:44 GMT", "version": "v2" } ]
2009-11-07
[ [ "Cacciapaglia", "G.", "" ], [ "Cirelli", "M.", "" ], [ "Lin", "Y.", "" ], [ "Romanino", "A.", "" ] ]
We discuss the phenomenology of neutrino mixing with bulk fermions in the context of supernova physics. The constraints on the parameter space following from the usual energy loss argument can be relaxed by four orders of magnitude due to a feedback mechanism that takes place in a broad region of the parameter space. Such a mechanism also affects the protoneutron star evolution through a non trivial interplay with neutrino diffusion. The consistency with the SN 1987A signal is discussed, as well as the implications for deleptonization, cooling, composition of the neutrino flux and the delayed explosion scenario.
hep-ph/9410349
Chi-Keung Chow
Chi-Keung Chow
Conservation Laws and Sum Rules in the Heavy Quark Limit
14 pages. Two figures available upon request. CALT-68-1958
Phys.Rev. D51 (1995) 3587-3592
10.1103/PhysRevD.51.3587
null
hep-ph
null
In the heavy quark limit, hadrons appear as eigenstates of the light degrees of freedom under the static color field of the heavy quark. In this formalism, the weak form factors appear naturally as the overlaps of the initial and final wavefunctions of the light degrees of freedom, and the Bjorken and Voloshin sum rules are statements of conservation of probability and energy. Moreover, parity conservation can lead to a sum rule which relates weak form factors at different kinematic points. {}From this sum rule, model independent lower bounds on Isgur--Wise form factors can be obtained analytically.
[ { "created": "Sat, 22 Oct 1994 23:11:21 GMT", "version": "v1" } ]
2009-10-28
[ [ "Chow", "Chi-Keung", "" ] ]
In the heavy quark limit, hadrons appear as eigenstates of the light degrees of freedom under the static color field of the heavy quark. In this formalism, the weak form factors appear naturally as the overlaps of the initial and final wavefunctions of the light degrees of freedom, and the Bjorken and Voloshin sum rules are statements of conservation of probability and energy. Moreover, parity conservation can lead to a sum rule which relates weak form factors at different kinematic points. {}From this sum rule, model independent lower bounds on Isgur--Wise form factors can be obtained analytically.
hep-ph/0504204
Nils Tornqvist
Nils A. Tornqvist
Mixing the Strong and E-W Higgs Sectors
Version to appear in PLB. Referencess added. Acknowledgement support corrected. Minor improvements in text
Phys.Lett. B619 (2005) 145-148
10.1016/j.physletb.2005.05.058
null
hep-ph nucl-th
null
After noting the well known similarity of the minimal electro-weak Higgs sector with the linear sigma model for the pion and the sigma, it is found that a small mixing term between the two models generates a pion mass. Although the custodial SU(2)L x SU(2)R, and the gauged SU(2)L x U(1) symmetry for the whole model remains intact, the mixing breaks the relative chiral symmetry between the two sectors. The mixing should be calculable from light quark masses as a quantum correction. This simple mechanism of "relative symmetry breaking" is believed to have applications for other forms of symmetry breaking.
[ { "created": "Fri, 22 Apr 2005 09:52:10 GMT", "version": "v1" }, { "created": "Sat, 23 Apr 2005 09:40:46 GMT", "version": "v2" }, { "created": "Mon, 2 May 2005 09:09:46 GMT", "version": "v3" }, { "created": "Thu, 26 May 2005 09:42:43 GMT", "version": "v4" } ]
2009-11-11
[ [ "Tornqvist", "Nils A.", "" ] ]
After noting the well known similarity of the minimal electro-weak Higgs sector with the linear sigma model for the pion and the sigma, it is found that a small mixing term between the two models generates a pion mass. Although the custodial SU(2)L x SU(2)R, and the gauged SU(2)L x U(1) symmetry for the whole model remains intact, the mixing breaks the relative chiral symmetry between the two sectors. The mixing should be calculable from light quark masses as a quantum correction. This simple mechanism of "relative symmetry breaking" is believed to have applications for other forms of symmetry breaking.
hep-ph/0205202
Dietrich Bodeker
Dietrich Bodeker
Perturbative and non-perturbative aspects of the non-abelian Boltzmann-Langevin equation
Some discussions and notations clarified
Nucl.Phys. B647 (2002) 512-538
10.1016/S0550-3213(02)00841-6
BI-TP 2002/08
hep-ph
null
We study the Boltzmann-Langevin equation which describes the dynamics of hot Yang-Mills fields with typical momenta of order of the magnetic screening scale g^2 T. It is transformed into a path integral and Feynman rules are obtained. We find that the leading log Langevin equation can be systematically improved in a well behaved expansion in log(1/g)^-1. The result by Arnold and Yaffe that the leading log Langevin equation is still valid at next-to-leading-log order is confirmed. We also confirm their result for the next-to-leading-log damping coefficient, or color conductivity, which is shown to be gauge fixing independent for a certain class of gauges. The frequency scale g^2T does not contribute to this result, but it does contribute, by power counting, to the transverse gauge field propagator. Going beyond a perturbative expansion we find 1-loop ultraviolet divergences which cannot be removed by renormalizing the parameters in the Boltzmann-Langevin equation.
[ { "created": "Sat, 18 May 2002 18:02:13 GMT", "version": "v1" }, { "created": "Wed, 11 Sep 2002 17:02:10 GMT", "version": "v2" } ]
2010-04-05
[ [ "Bodeker", "Dietrich", "" ] ]
We study the Boltzmann-Langevin equation which describes the dynamics of hot Yang-Mills fields with typical momenta of order of the magnetic screening scale g^2 T. It is transformed into a path integral and Feynman rules are obtained. We find that the leading log Langevin equation can be systematically improved in a well behaved expansion in log(1/g)^-1. The result by Arnold and Yaffe that the leading log Langevin equation is still valid at next-to-leading-log order is confirmed. We also confirm their result for the next-to-leading-log damping coefficient, or color conductivity, which is shown to be gauge fixing independent for a certain class of gauges. The frequency scale g^2T does not contribute to this result, but it does contribute, by power counting, to the transverse gauge field propagator. Going beyond a perturbative expansion we find 1-loop ultraviolet divergences which cannot be removed by renormalizing the parameters in the Boltzmann-Langevin equation.
1912.13327
Gerardo Hern\'andez-Tom\'e
G. Hern\'andez-Tom\'e, J. I. Illana, G. L\'opez Castro, M. Masip, P. Roig
Effects of heavy Majorana neutrinos on lepton flavor violating processes
Accepted for publication in PRD, discussions and references added; 13 pages, 7 figures
Phys. Rev. D 101, 075020 (2020)
10.1103/PhysRevD.101.075020
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The observation of lepton flavor violating processes at colliders could be a clear signal of a non-minimal neutrino sector. We define a 5-parameter model with a pair of TeV fermion singlets and arbitrary mixings with the three active neutrino flavors. Then we analyze several flavor violating transitions ($\ell\to \ell^{\prime}\gamma,\,\ell^{\prime}\ell^{\prime\prime}\bar{\ell}^{\prime\prime\prime}$ or $\mu-e$ conversions in nuclei) and $Z\to\bar{\ell}\,\ell^{\prime}$ decays induced by the presence of heavy neutrinos. In particular, we calculate all the one-loop contributions to these processes and present their analytic expressions. We focus on the genuine effects of the heavy Majorana masses, comparing the results in that case with the ones obtained when the two heavy neutrinos define a Dirac field. Finally, we use our results to update the bounds on the heavy-light mixings in the neutrino sector.
[ { "created": "Tue, 31 Dec 2019 14:46:39 GMT", "version": "v1" }, { "created": "Wed, 15 Jan 2020 15:18:48 GMT", "version": "v2" }, { "created": "Wed, 18 Mar 2020 11:25:51 GMT", "version": "v3" } ]
2020-04-15
[ [ "Hernández-Tomé", "G.", "" ], [ "Illana", "J. I.", "" ], [ "Castro", "G. López", "" ], [ "Masip", "M.", "" ], [ "Roig", "P.", "" ] ]
The observation of lepton flavor violating processes at colliders could be a clear signal of a non-minimal neutrino sector. We define a 5-parameter model with a pair of TeV fermion singlets and arbitrary mixings with the three active neutrino flavors. Then we analyze several flavor violating transitions ($\ell\to \ell^{\prime}\gamma,\,\ell^{\prime}\ell^{\prime\prime}\bar{\ell}^{\prime\prime\prime}$ or $\mu-e$ conversions in nuclei) and $Z\to\bar{\ell}\,\ell^{\prime}$ decays induced by the presence of heavy neutrinos. In particular, we calculate all the one-loop contributions to these processes and present their analytic expressions. We focus on the genuine effects of the heavy Majorana masses, comparing the results in that case with the ones obtained when the two heavy neutrinos define a Dirac field. Finally, we use our results to update the bounds on the heavy-light mixings in the neutrino sector.
hep-ph/9806257
Marek Gazdzicki
Marek Gazdzicki
Quark Gluon Plasma in a+a Collisions at CERN SPS
10 pages
null
null
null
hep-ph
null
A brief review of a history of data collection and interpretation of the results on high energy A+A collisions is presented. Basic assumptions and main results of a statistical model of the early stage of the A+A collisions are discussed. It is concluded that a broad set of experimental data is in agreement with the hypothesis that QGP is created in central A+A (S+S and Pb+Pb) collisions at the SPS. Carefull experimental investigation of the A+A collisions in the energy region between top AGS and SPS energies is needed.
[ { "created": "Thu, 4 Jun 1998 12:54:33 GMT", "version": "v1" } ]
2007-05-23
[ [ "Gazdzicki", "Marek", "" ] ]
A brief review of a history of data collection and interpretation of the results on high energy A+A collisions is presented. Basic assumptions and main results of a statistical model of the early stage of the A+A collisions are discussed. It is concluded that a broad set of experimental data is in agreement with the hypothesis that QGP is created in central A+A (S+S and Pb+Pb) collisions at the SPS. Carefull experimental investigation of the A+A collisions in the energy region between top AGS and SPS energies is needed.
0908.1870
Francesco Hautmann
M. Deak, F. Hautmann, H. Jung and K. Kutak
Jets in the forward region at the LHC
Presented at the XLIV Rencontres de Moriond, March 2009
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss jet production at forward rapidities at the LHC. In this region QCD logarithmic corrections in the hard transverse momentum and in the large rapidity interval may both be quantitatively significant. We describe results of using high-energy factorization techniques, which allow one to take into account both kinds of corrections to higher orders in QCD.
[ { "created": "Thu, 13 Aug 2009 11:04:35 GMT", "version": "v1" } ]
2009-08-14
[ [ "Deak", "M.", "" ], [ "Hautmann", "F.", "" ], [ "Jung", "H.", "" ], [ "Kutak", "K.", "" ] ]
We discuss jet production at forward rapidities at the LHC. In this region QCD logarithmic corrections in the hard transverse momentum and in the large rapidity interval may both be quantitatively significant. We describe results of using high-energy factorization techniques, which allow one to take into account both kinds of corrections to higher orders in QCD.
hep-ph/0004262
Yan Qi-shu
Qi-Shu Yan, Chao-Shang Huang, Liao Wei, and Shou-Hua Zhu
Exclusive semileptonic rare decays $B ->_ ($K,K^*) \ell^+ \ell^- in supersymmetric theories
Several references are added, typo are corrected
Phys.Rev.D62:094023,2000
10.1103/PhysRevD.62.094023
TUHEP-TH-00116
hep-ph
null
The invariant mass spectrum, forward-backward asymmetry, and lepton polarizations of the exclusive processes $B\to K(K^*)\ell^+ \ell^-, \ell=\mu, \tau$ are analyzed under supersymmetric context. Special attention is paid to the effects of neutral Higgs bosons (NHBs). Our analysis shows that the branching ratio of the process $\bkm$ can be quite largely modified by the effects of neutral Higgs bosons and the forward-backward asymmetry would not vanish. For the process $\bksm$, the lepton transverse polarization is quite sensitive to the effects of NHBs, while the invariant mass spectrum, forward-backward asymmetry, and lepton longitudinal polarization are not. For both $\bkt$ and $\bkst$, the effects of NHBs are quite significant. The partial decay widths of these processes are also analyzed, and our analysis manifest that even taking into account the theoretical uncertainties in calculating weak form factors, the effects of NHBs could make SUSY shown up.
[ { "created": "Fri, 28 Apr 2000 05:50:51 GMT", "version": "v1" }, { "created": "Sat, 29 Apr 2000 07:01:18 GMT", "version": "v2" }, { "created": "Wed, 3 May 2000 09:22:13 GMT", "version": "v3" }, { "created": "Mon, 15 May 2000 07:15:35 GMT", "version": "v4" }, { "created": "Thu, 22 Jun 2000 16:25:11 GMT", "version": "v5" } ]
2011-03-23
[ [ "Yan", "Qi-Shu", "" ], [ "Huang", "Chao-Shang", "" ], [ "Wei", "Liao", "" ], [ "Zhu", "Shou-Hua", "" ] ]
The invariant mass spectrum, forward-backward asymmetry, and lepton polarizations of the exclusive processes $B\to K(K^*)\ell^+ \ell^-, \ell=\mu, \tau$ are analyzed under supersymmetric context. Special attention is paid to the effects of neutral Higgs bosons (NHBs). Our analysis shows that the branching ratio of the process $\bkm$ can be quite largely modified by the effects of neutral Higgs bosons and the forward-backward asymmetry would not vanish. For the process $\bksm$, the lepton transverse polarization is quite sensitive to the effects of NHBs, while the invariant mass spectrum, forward-backward asymmetry, and lepton longitudinal polarization are not. For both $\bkt$ and $\bkst$, the effects of NHBs are quite significant. The partial decay widths of these processes are also analyzed, and our analysis manifest that even taking into account the theoretical uncertainties in calculating weak form factors, the effects of NHBs could make SUSY shown up.
hep-ph/0402142
Antonio Lopez Maroto
J.A.R. Cembranos, A. Dobado, A.L. Maroto
Branons as dark matter
Contribution to the Tenth Marcel Grossmann Meeting on General Relativity. 3 pages, 1 figure, uses ws-proc
null
10.1142/9789812704030_0336
null
hep-ph astro-ph hep-th
null
In the brane-world scenario with low tension, brane fluctuations (branons) together with the Standard Model particles are the only relevant degrees of freedom at low energies. Branons are stable, weakly interacting, massive particles and their relic abundance can account for the dark matter of the universe. In a certain range of the parameter space, they could be detectable by future direct search experiments.
[ { "created": "Fri, 13 Feb 2004 14:15:13 GMT", "version": "v1" } ]
2016-11-09
[ [ "Cembranos", "J. A. R.", "" ], [ "Dobado", "A.", "" ], [ "Maroto", "A. L.", "" ] ]
In the brane-world scenario with low tension, brane fluctuations (branons) together with the Standard Model particles are the only relevant degrees of freedom at low energies. Branons are stable, weakly interacting, massive particles and their relic abundance can account for the dark matter of the universe. In a certain range of the parameter space, they could be detectable by future direct search experiments.
1904.00978
Shuai Zhao
Wei Wang, Jian-Hui Zhang, Shuai Zhao, Ruilin Zhu
Complete Matching for Quasi-distribution Functions in Large Momentum Effective Theory
29 pages, 5 figures. Errors in Eq. (90) are corrected
Phys. Rev. D 100, 074509 (2019)
10.1103/PhysRevD.100.074509
JLAB-THY-19-2907
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We complete the procedure of extracting parton distribution functions (PDFs) using large momentum effective theory (LaMET) at leading power accuracy in the hadron momentum. We derive a general factorization formula for the quasi PDFs in the presence of mixing, and give the corresponding hard matching kernel at $\mathcal O(\alpha_s)$, both for the unpolarized and for the polarized quark and gluon quasi-PDFs. Our calculation is performed in a regularization-independent momentum subtraction scheme. The results allow us to match the nonperturbatively renormalized quasi-PDFs to normal PDFs in the presence of mixing, and therefore can be used to extract flavor-singlet quark PDFs as well as gluon PDFs from lattice simulations.
[ { "created": "Mon, 1 Apr 2019 17:30:46 GMT", "version": "v1" }, { "created": "Tue, 29 Oct 2019 02:48:03 GMT", "version": "v2" }, { "created": "Tue, 10 Nov 2020 13:55:23 GMT", "version": "v3" } ]
2020-11-11
[ [ "Wang", "Wei", "" ], [ "Zhang", "Jian-Hui", "" ], [ "Zhao", "Shuai", "" ], [ "Zhu", "Ruilin", "" ] ]
We complete the procedure of extracting parton distribution functions (PDFs) using large momentum effective theory (LaMET) at leading power accuracy in the hadron momentum. We derive a general factorization formula for the quasi PDFs in the presence of mixing, and give the corresponding hard matching kernel at $\mathcal O(\alpha_s)$, both for the unpolarized and for the polarized quark and gluon quasi-PDFs. Our calculation is performed in a regularization-independent momentum subtraction scheme. The results allow us to match the nonperturbatively renormalized quasi-PDFs to normal PDFs in the presence of mixing, and therefore can be used to extract flavor-singlet quark PDFs as well as gluon PDFs from lattice simulations.
hep-ph/0204080
Zurab Tavartkiladze
Filipe Paccetti Correia, Michael G. Schmidt, Zurab Tavartkiladze
Gauge Coupling Unification and Phenomenology of Selected Orbifold 5D N=1 SUSY Models
Version to appear in Nucl. Phys. B
Nucl.Phys.B649:39-87,2003
10.1016/S0550-3213(02)00978-1
null
hep-ph
null
We study gauge coupling unification and various phenomenological issues, such as baryon number conservation, the $\mu $ problem and neutrino anomalies, within SUSY 5D orbifold models. The 5D MSSM on an $S^{(1)}/Z_2$ orbifold with 'minimal' field content does not lead to low scale unification, while some of its extensions can give unification near the multi TeV scale. Within the orbifold SU(5) GUT, low scale unification can not be realized due to full SU(5) multiplets participating in the renormalization above the compactification scale. As alternative examples, we construct 5D N=1 SUSY Pati-Salam $SU(4)_c\tm SU(2)_L\tm SU(2)_R\equiv G_{422}$ and flipped $SU(5)\tm U(1)\equiv G_{51}$ GUTs [both maximal subgroups of SO(10)] on an $S^{(1)}/Z_2\tm Z_2'$ orbifold. New examples of low scale unifications within $G_{422}$ are presented. For $G_{51}$ the unification scale is shown to be necessarily close to $\sim 10^{16}$ GeV. The possible influence of brane couplings on the gauge coupling unification is also outlined. For the resolution of the various phenomenological problems extensions with a discrete ${\cal Z}$ symmetry turn out to be very effective.
[ { "created": "Sat, 6 Apr 2002 20:17:11 GMT", "version": "v1" }, { "created": "Mon, 29 Apr 2002 16:56:21 GMT", "version": "v2" }, { "created": "Mon, 4 Nov 2002 16:35:23 GMT", "version": "v3" } ]
2008-11-26
[ [ "Correia", "Filipe Paccetti", "" ], [ "Schmidt", "Michael G.", "" ], [ "Tavartkiladze", "Zurab", "" ] ]
We study gauge coupling unification and various phenomenological issues, such as baryon number conservation, the $\mu $ problem and neutrino anomalies, within SUSY 5D orbifold models. The 5D MSSM on an $S^{(1)}/Z_2$ orbifold with 'minimal' field content does not lead to low scale unification, while some of its extensions can give unification near the multi TeV scale. Within the orbifold SU(5) GUT, low scale unification can not be realized due to full SU(5) multiplets participating in the renormalization above the compactification scale. As alternative examples, we construct 5D N=1 SUSY Pati-Salam $SU(4)_c\tm SU(2)_L\tm SU(2)_R\equiv G_{422}$ and flipped $SU(5)\tm U(1)\equiv G_{51}$ GUTs [both maximal subgroups of SO(10)] on an $S^{(1)}/Z_2\tm Z_2'$ orbifold. New examples of low scale unifications within $G_{422}$ are presented. For $G_{51}$ the unification scale is shown to be necessarily close to $\sim 10^{16}$ GeV. The possible influence of brane couplings on the gauge coupling unification is also outlined. For the resolution of the various phenomenological problems extensions with a discrete ${\cal Z}$ symmetry turn out to be very effective.
2109.13219
Aleksey Rusov
Daniel King, Alexander Lenz, Maria Laura Piscopo, Thomas Rauh, Aleksey V. Rusov, Christos Vlahos
Revisiting Inclusive Decay Widths of Charmed Mesons
50 pages, 18 Tables, 7 Figures
null
10.1007/JHEP08(2022)241
SI-HEP-2021-23, SFB-257-P3H-21-058, IPPP/21/22
hep-ph
http://creativecommons.org/licenses/by/4.0/
Determining for the first time the Darwin operator contribution for the non-leptonic charm-quark decays and using new non-perturbative results for the matrix elements of $\Delta C=0$ four-quark operators, including eye-contractions, we present a comprehensive study of the lifetimes of charmed mesons and inclusive semileptonic decay rates as well as the ratios, within the framework of the Heavy Quark Expansion (HQE). We find good agreement with experiment for the ratio $\tau(D^+)/\tau(D^0)$, for the total $D_s^+$-meson decay rate, for the semileptonic rates of all three mesons $D^0$, $D^+$ and $D_s^+$, and for the semileptonic ratio $\Gamma_{sl}^{D^+}/\Gamma_{sl}^{D^0}$. The total decay rates of the $D^0$ and $D^+$ mesons are underestimated in our HQE approach and we suspect that this is due to missing higher-order QCD corrections to the free charm quark decay and the Pauli interference contribution. For the $SU(3)_F$ breaking ratios $\tau (D_s^+) / \tau (D^0) $ and $\Gamma_{sl}^{D_s^+}/\Gamma_{sl}^{D^0} $ our predictions lie closer to one than experiment. This might originate from the poor knowledge of the non-perturbative parameters $\mu_G^2$, $\mu_\pi^2$ and $\rho_D^3$ in the $D^0$ and $D_s^+$ systems. These parameters could be determined by experimental studies of the moments of inclusive semileptonic $D$ meson decays.
[ { "created": "Mon, 27 Sep 2021 17:43:15 GMT", "version": "v1" } ]
2022-09-07
[ [ "King", "Daniel", "" ], [ "Lenz", "Alexander", "" ], [ "Piscopo", "Maria Laura", "" ], [ "Rauh", "Thomas", "" ], [ "Rusov", "Aleksey V.", "" ], [ "Vlahos", "Christos", "" ] ]
Determining for the first time the Darwin operator contribution for the non-leptonic charm-quark decays and using new non-perturbative results for the matrix elements of $\Delta C=0$ four-quark operators, including eye-contractions, we present a comprehensive study of the lifetimes of charmed mesons and inclusive semileptonic decay rates as well as the ratios, within the framework of the Heavy Quark Expansion (HQE). We find good agreement with experiment for the ratio $\tau(D^+)/\tau(D^0)$, for the total $D_s^+$-meson decay rate, for the semileptonic rates of all three mesons $D^0$, $D^+$ and $D_s^+$, and for the semileptonic ratio $\Gamma_{sl}^{D^+}/\Gamma_{sl}^{D^0}$. The total decay rates of the $D^0$ and $D^+$ mesons are underestimated in our HQE approach and we suspect that this is due to missing higher-order QCD corrections to the free charm quark decay and the Pauli interference contribution. For the $SU(3)_F$ breaking ratios $\tau (D_s^+) / \tau (D^0) $ and $\Gamma_{sl}^{D_s^+}/\Gamma_{sl}^{D^0} $ our predictions lie closer to one than experiment. This might originate from the poor knowledge of the non-perturbative parameters $\mu_G^2$, $\mu_\pi^2$ and $\rho_D^3$ in the $D^0$ and $D_s^+$ systems. These parameters could be determined by experimental studies of the moments of inclusive semileptonic $D$ meson decays.
hep-ph/9408396
Hilmar Forkel
Hilmar Forkel and Marina Nielsen
The Electromagnetic Pion Form Factor and Instantons
12 pages, UMPP \#95--035, (2 figures available on request by e-mail or FAX)
Phys.Lett. B345 (1995) 55-60
10.1016/0370-2693(94)01596-5
null
hep-ph
null
We calculate the electromagnetic pion form factor at intermediate space-like momentum transfer from the QCD sum rule for the correlation function of two {\it pseudoscalar } interpolating fields and the electromagnetic current. This correlator receives essential contributions from direct ({\it i.e.} small-scale) instantons, which we evaluate under the assumption of an instanton size distribution consistent with instanton liquid and lattice simulations. The resulting form factor is in good agreement both with the sum rule based on the axial-current correlator and with experiment.
[ { "created": "Tue, 30 Aug 1994 22:59:15 GMT", "version": "v1" } ]
2009-10-28
[ [ "Forkel", "Hilmar", "" ], [ "Nielsen", "Marina", "" ] ]
We calculate the electromagnetic pion form factor at intermediate space-like momentum transfer from the QCD sum rule for the correlation function of two {\it pseudoscalar } interpolating fields and the electromagnetic current. This correlator receives essential contributions from direct ({\it i.e.} small-scale) instantons, which we evaluate under the assumption of an instanton size distribution consistent with instanton liquid and lattice simulations. The resulting form factor is in good agreement both with the sum rule based on the axial-current correlator and with experiment.
hep-ph/9206244
Daniel Ng
Jyoti Agrawal, Paul H. Frampton and Daniel Ng
Dilepton Production in $e^- p$ and $e^+ e^-$ Colliders
16 pages, 3 figures (not included), IFP-428-UNC
Nucl.Phys. B386 (1992) 267-279
10.1016/0550-3213(92)90567-U
null
hep-ph
null
In an $e^- p$ collider, a striking signature for a dilepton gauge boson is \ep \ ; this cross-section is calculated by using the helicity amplitude technique. At HERA, with center-of-mass energy $\sqrt s = 314 GeV$, a dilepton mass above $150 GeV$ is inaccessible but at LEPII-LHC, with a center-of-mass energy $\sqrt s = 1790 GeV $, masses up to 650 GeV can be discovered. In an $e^+ e^-$ collider, the signature is \ee \ . The cross-sections of this process are also calculated for the center-of-mass energies $\sqrt s = 200, 500$ and $1000 GeV$.
[ { "created": "Tue, 23 Jun 1992 14:04:15 GMT", "version": "v1" } ]
2009-10-22
[ [ "Agrawal", "Jyoti", "" ], [ "Frampton", "Paul H.", "" ], [ "Ng", "Daniel", "" ] ]
In an $e^- p$ collider, a striking signature for a dilepton gauge boson is \ep \ ; this cross-section is calculated by using the helicity amplitude technique. At HERA, with center-of-mass energy $\sqrt s = 314 GeV$, a dilepton mass above $150 GeV$ is inaccessible but at LEPII-LHC, with a center-of-mass energy $\sqrt s = 1790 GeV $, masses up to 650 GeV can be discovered. In an $e^+ e^-$ collider, the signature is \ee \ . The cross-sections of this process are also calculated for the center-of-mass energies $\sqrt s = 200, 500$ and $1000 GeV$.
2401.08384
Sadaf Madni
Sadaf Madni, Arghya Mukherjee, Amaresh Jaiswal, Najmul Haque
Shear and bulk viscosity of quark-gluon plasma with Gribov gluons and quasiparticle quarks
null
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this paper, we investigate the transport coefficients, specifically the bulk ($\zeta $) and shear ($\eta$) viscosity coefficients of hot QCD matter at finite temperature and vanishing chemical potential. For gluonic plasma, we consider the Gribov's prescription for the gluon propagator, which has been proven to be effective in exploring the non-perturbative region. For a system of quark-gluon plasma (QGP), we adopt the quasiparticle prescription for quarks along with the Gribov's prescription for gluons. We determine the Gribov parameter and quasi-quark mass by utilizing lattice QCD data for the equation-of-state of pure glue and QGP, respectively. Our primary objective is to examine the influence of quasi-quarks on the transport coefficients of QGP. In the end, we observed a significant decrease in the scaled transport coefficients with temperature across the entire relevant temperature range ($ 1 \le T/T_c \le 3 $).
[ { "created": "Tue, 16 Jan 2024 14:16:54 GMT", "version": "v1" } ]
2024-01-17
[ [ "Madni", "Sadaf", "" ], [ "Mukherjee", "Arghya", "" ], [ "Jaiswal", "Amaresh", "" ], [ "Haque", "Najmul", "" ] ]
In this paper, we investigate the transport coefficients, specifically the bulk ($\zeta $) and shear ($\eta$) viscosity coefficients of hot QCD matter at finite temperature and vanishing chemical potential. For gluonic plasma, we consider the Gribov's prescription for the gluon propagator, which has been proven to be effective in exploring the non-perturbative region. For a system of quark-gluon plasma (QGP), we adopt the quasiparticle prescription for quarks along with the Gribov's prescription for gluons. We determine the Gribov parameter and quasi-quark mass by utilizing lattice QCD data for the equation-of-state of pure glue and QGP, respectively. Our primary objective is to examine the influence of quasi-quarks on the transport coefficients of QGP. In the end, we observed a significant decrease in the scaled transport coefficients with temperature across the entire relevant temperature range ($ 1 \le T/T_c \le 3 $).
2303.07521
Olcyr Sumensari
S\'ebastien Descotes-Genon, Darius A. Faroughy, Ioannis Plakias and Olcyr Sumensari
Probing Lepton Flavor Violation in Meson Decays with LHC Data
11 pages, 2 tables, 4 figs; typos corrected, published in EPJC
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
In this letter, we use LHC data from the Drell-Yan processes $pp\to\ell_i\ell_j$ (with $i\neq j$) to derive model-independent upper limits on lepton-flavor-violating meson decays. Our analysis is based on an Effective Field Theory (EFT) approach and it does not require a specific assumption regarding the basis of effective operators. We find that current LHC data (140~$\mathrm{fb}^{-1}$) already provides competitive limits on $B(B\to \pi e \tau)$ and $B(B\to \pi \mu \tau)$ with respect to the ones obtained through experimental searches at the $B$-factories. Moreover, we derive upper limits on several decays that have not been searched for experimentally yet, such as $D^0\to e\tau$ in the charm sector, and various semileptonic decays such as $B\to \rho \mu\tau$, $B_s\to K \mu\tau$ and $B_s\to\phi\mu\tau$. Lastly, we discuss the validity of the EFT description of LHC data and the impact of loop corrections in our analysis.
[ { "created": "Mon, 13 Mar 2023 23:17:49 GMT", "version": "v1" }, { "created": "Wed, 21 Feb 2024 12:37:57 GMT", "version": "v2" } ]
2024-02-22
[ [ "Descotes-Genon", "Sébastien", "" ], [ "Faroughy", "Darius A.", "" ], [ "Plakias", "Ioannis", "" ], [ "Sumensari", "Olcyr", "" ] ]
In this letter, we use LHC data from the Drell-Yan processes $pp\to\ell_i\ell_j$ (with $i\neq j$) to derive model-independent upper limits on lepton-flavor-violating meson decays. Our analysis is based on an Effective Field Theory (EFT) approach and it does not require a specific assumption regarding the basis of effective operators. We find that current LHC data (140~$\mathrm{fb}^{-1}$) already provides competitive limits on $B(B\to \pi e \tau)$ and $B(B\to \pi \mu \tau)$ with respect to the ones obtained through experimental searches at the $B$-factories. Moreover, we derive upper limits on several decays that have not been searched for experimentally yet, such as $D^0\to e\tau$ in the charm sector, and various semileptonic decays such as $B\to \rho \mu\tau$, $B_s\to K \mu\tau$ and $B_s\to\phi\mu\tau$. Lastly, we discuss the validity of the EFT description of LHC data and the impact of loop corrections in our analysis.
1912.01585
Sebastian Jaskiewicz
Martin Beneke, Alessandro Broggio, Sebastian Jaskiewicz, Leonardo Vernazza
Threshold factorization of the Drell-Yan process at next-to-leading power
Matches published version
Journal of High Energy Physics. 2020, 78 (2020)
10.1007/JHEP07(2020)078
TUM-HEP-1239/19
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a factorization theorem valid near the kinematic threshold $z=Q^2/\hat{s}\to 1$ of the partonic Drell-Yan process $q\bar q\to\gamma^*+X$ for general subleading powers in the $(1-z)$ expansion. We then consider the specific case of next-to-leading power. We discuss the emergence of collinear functions, which are a key ingredient to factorization starting at next-to-leading power. We calculate the relevant collinear functions at $\mathcal{O}(\alpha_s)$ by employing an operator matching equation and we compare our results to the expansion-by-regions computation up to the next-to-next-to-leading order, finding agreement. Factorization holds only before the dimensional regulator is removed, due to a divergent convolution when the collinear and soft functions are first expanded around $d=4$ before the convolution is performed. This demonstrates an issue for threshold resummation beyond the leading-logarithmic accuracy at next-to-leading power.
[ { "created": "Tue, 3 Dec 2019 18:31:12 GMT", "version": "v1" }, { "created": "Wed, 15 Jul 2020 17:39:50 GMT", "version": "v2" } ]
2020-07-16
[ [ "Beneke", "Martin", "" ], [ "Broggio", "Alessandro", "" ], [ "Jaskiewicz", "Sebastian", "" ], [ "Vernazza", "Leonardo", "" ] ]
We present a factorization theorem valid near the kinematic threshold $z=Q^2/\hat{s}\to 1$ of the partonic Drell-Yan process $q\bar q\to\gamma^*+X$ for general subleading powers in the $(1-z)$ expansion. We then consider the specific case of next-to-leading power. We discuss the emergence of collinear functions, which are a key ingredient to factorization starting at next-to-leading power. We calculate the relevant collinear functions at $\mathcal{O}(\alpha_s)$ by employing an operator matching equation and we compare our results to the expansion-by-regions computation up to the next-to-next-to-leading order, finding agreement. Factorization holds only before the dimensional regulator is removed, due to a divergent convolution when the collinear and soft functions are first expanded around $d=4$ before the convolution is performed. This demonstrates an issue for threshold resummation beyond the leading-logarithmic accuracy at next-to-leading power.
hep-ph/9312222
null
Zurab G. Berezhiani
Grand Unification of Fermion Masses
22 pages (standard LATEX) + 1 Figure (postscript file, cut out and print separately), Ferrara preprint INFN-FE-13-93
null
null
null
hep-ph
null
After a brief review of the flavour problem we present a new predictive framework based on SUSY $SO(10)$ theory, where the first family plays a role of the mass unification point. The inter-family hierarchy is first generated in a sector of superheavy fermions and then transfered in an inverse way to ordinary quarks and leptons by means of the universal seesaw mechanism. The obtained mass matrices are simply parametrized by two small coefficients which can be given by the ratio of the GUT and superstring compactification scales. The model allows a natural (without fine tuning) doublet-triplet splitting. It has a strong predictive power, though no special texture is utilized in contrast to the known predictive frameworks. Namely, the model implies that $m_b=4-5$ GeV, $m_s=100-150$ MeV, $m_u/m_d=0.5-0.7$ and $\tan\beta<1.1$. The Top quark is naturally in the 100 GeV range, but not too heavy: $m_t<150$ GeV. All CKM mixing angles are in correct range. The Higgsino mediated $d=5$ operators for the proton decay are naturally suppressed. {On the basis of talks given at the XVI International Warsaw Meeting on Elementary Particle Physics "New Physics with New Experiments", Kazimierz, Poland, 24-28 May 1993, and at the II Gran Sasso Summer Institute "From Particle Physics to Cosmology", Gran Sasso National Laboratory, Italy, 6-17 September 1993.}
[ { "created": "Mon, 6 Dec 1993 01:00:00 GMT", "version": "v1" } ]
2009-09-25
[ [ "Berezhiani", "Zurab G.", "" ] ]
After a brief review of the flavour problem we present a new predictive framework based on SUSY $SO(10)$ theory, where the first family plays a role of the mass unification point. The inter-family hierarchy is first generated in a sector of superheavy fermions and then transfered in an inverse way to ordinary quarks and leptons by means of the universal seesaw mechanism. The obtained mass matrices are simply parametrized by two small coefficients which can be given by the ratio of the GUT and superstring compactification scales. The model allows a natural (without fine tuning) doublet-triplet splitting. It has a strong predictive power, though no special texture is utilized in contrast to the known predictive frameworks. Namely, the model implies that $m_b=4-5$ GeV, $m_s=100-150$ MeV, $m_u/m_d=0.5-0.7$ and $\tan\beta<1.1$. The Top quark is naturally in the 100 GeV range, but not too heavy: $m_t<150$ GeV. All CKM mixing angles are in correct range. The Higgsino mediated $d=5$ operators for the proton decay are naturally suppressed. {On the basis of talks given at the XVI International Warsaw Meeting on Elementary Particle Physics "New Physics with New Experiments", Kazimierz, Poland, 24-28 May 1993, and at the II Gran Sasso Summer Institute "From Particle Physics to Cosmology", Gran Sasso National Laboratory, Italy, 6-17 September 1993.}
1206.4201
Adam Falkowski
Dean Carmi, Adam Falkowski, Eric Kuflik, and Tomer Volansky
Interpreting the Higgs
Contribution to the proceedings of the XXVI Rencontres de Physique de la Vallee d'Aoste, La Thuile 2012. v2: typos in Eq. 2.4 corrected
null
10.1393/ncc/i2012-11386-2
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The LHC and Tevatron Higgs data are interpreted as constraints on an effective theory of a Higgs boson with mass close to 125 GeV. We focus on the diphoton, ZZ*, WW* channels at the LHC, and the b-bbar channel at the Tevatron, which are currently the most sensitive probes of a Higgs with such a mass. Combining the available data in these channels, we derive the preferred regions of the parameter space of the effective theory. We further provide the mapping between the effective theory and the relevant Higgs event rates, facilitating future extraction of the preferred region by the ATLAS and CMS collaborations.
[ { "created": "Tue, 19 Jun 2012 13:20:53 GMT", "version": "v1" }, { "created": "Fri, 20 Jul 2012 16:23:26 GMT", "version": "v2" } ]
2022-03-02
[ [ "Carmi", "Dean", "" ], [ "Falkowski", "Adam", "" ], [ "Kuflik", "Eric", "" ], [ "Volansky", "Tomer", "" ] ]
The LHC and Tevatron Higgs data are interpreted as constraints on an effective theory of a Higgs boson with mass close to 125 GeV. We focus on the diphoton, ZZ*, WW* channels at the LHC, and the b-bbar channel at the Tevatron, which are currently the most sensitive probes of a Higgs with such a mass. Combining the available data in these channels, we derive the preferred regions of the parameter space of the effective theory. We further provide the mapping between the effective theory and the relevant Higgs event rates, facilitating future extraction of the preferred region by the ATLAS and CMS collaborations.
1406.5047
Philipp Grothaus
Philipp Grothaus, Malcolm Fairbairn and Jocelyn Monroe
Directional Dark Matter Detection Beyond the Neutrino Bound
matches the published version, figure 4 updated plus extended discussion about neutrino flux uncertainties and detector resolutions, 13 pages, 11 figures
Phys. Rev. D 90, 055018 (2014)
10.1103/PhysRevD.90.055018
KCL-PH-TH/2014-28, LCTS/2014-27
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Coherent scattering of solar, atmospheric and diffuse supernovae neutrinos creates an irreducible background for direct dark matter experiments with sensitivities to WIMP-nucleon spin-independent scattering cross-sections of 10^(-46)-10^(-48) cm^2, depending on the WIMP mass. Even if one could eliminate all other backgrounds, this "neutrino floor" will limit future experiments with projected sensitivities to cross-sections as small as 10^(-48) cm^2. Direction-sensitive detectors have the potential to study dark matter beyond the neutrino bound by fitting event distributions in multiple dimensions: recoil kinetic energy, recoil track angle with respect to the sun, and event time. This work quantitatively explores the impact of direction-sensitivity on the neutrino bound in dark matter direct detection.
[ { "created": "Thu, 19 Jun 2014 13:52:15 GMT", "version": "v1" }, { "created": "Tue, 30 Sep 2014 17:02:58 GMT", "version": "v2" } ]
2014-10-01
[ [ "Grothaus", "Philipp", "" ], [ "Fairbairn", "Malcolm", "" ], [ "Monroe", "Jocelyn", "" ] ]
Coherent scattering of solar, atmospheric and diffuse supernovae neutrinos creates an irreducible background for direct dark matter experiments with sensitivities to WIMP-nucleon spin-independent scattering cross-sections of 10^(-46)-10^(-48) cm^2, depending on the WIMP mass. Even if one could eliminate all other backgrounds, this "neutrino floor" will limit future experiments with projected sensitivities to cross-sections as small as 10^(-48) cm^2. Direction-sensitive detectors have the potential to study dark matter beyond the neutrino bound by fitting event distributions in multiple dimensions: recoil kinetic energy, recoil track angle with respect to the sun, and event time. This work quantitatively explores the impact of direction-sensitivity on the neutrino bound in dark matter direct detection.
1304.1654
Patrick Otto Ludl
P.M. Ferreira, L. Lavoura, P.O. Ludl
Five models for lepton mixing
17 pages, 4 figures
null
10.1007/JHEP08(2013)113
CFTP/13-009, UWThPh-2013-9
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We produce five flavour models for the lepton sector. All five models fit perfectly well---at the one-sigma level---the existing data on the neutrino mass-squared differences and on the lepton mixing angles. The models are based on the type-I seesaw mechanism, on a Z_2 symmetry for each lepton flavour, and either on a (spontaneously broken) symmetry under the interchange of two lepton flavours or on a (spontaneously broken) CP symmetry incorporating that interchange---or on both symmetries simultaneously. Each model makes definite predictions both for the scale of the neutrino masses and for the phase delta in lepton mixing; the fifth model also predicts a correlation between the lepton mixing angles theta_12 and theta_23.
[ { "created": "Fri, 5 Apr 2013 09:25:07 GMT", "version": "v1" } ]
2015-06-15
[ [ "Ferreira", "P. M.", "" ], [ "Lavoura", "L.", "" ], [ "Ludl", "P. O.", "" ] ]
We produce five flavour models for the lepton sector. All five models fit perfectly well---at the one-sigma level---the existing data on the neutrino mass-squared differences and on the lepton mixing angles. The models are based on the type-I seesaw mechanism, on a Z_2 symmetry for each lepton flavour, and either on a (spontaneously broken) symmetry under the interchange of two lepton flavours or on a (spontaneously broken) CP symmetry incorporating that interchange---or on both symmetries simultaneously. Each model makes definite predictions both for the scale of the neutrino masses and for the phase delta in lepton mixing; the fifth model also predicts a correlation between the lepton mixing angles theta_12 and theta_23.
hep-ph/9710454
Tanaka Kazuhiro
Jiro Kodaira (Hiroshima Univ.), Takashi Nasuno (Hiroshima Univ.), Hiroshi Tochimura (Hiroshima Univ.), Kazuhiro Tanaka (Juntendo Univ.) and Yoshiaki Yasui (RIKEN-BNL)
Renormalization of the Twist-3 Flavor Singlet Operators in a Covariant Gauge
10 pages, 12 Postscript figures, LaTeX. Misprints corrected. Proceedings of the DESY workshop, "Deep inelastic scattering off polarized targets: Theory meets experiment" help at DESY-Zeuthen, September 1-5, 1997
null
null
null
hep-ph
null
We investigate the nucleon's transverse spin-dependent structure function g_2(x, Q^2) in the framework of the operator product expansion and the renormalization group. We construct the complete set of the twist-3 operators for the flavor singlet channel, and give the relations among them. We develop an efficient, covariant approach to derive the anomalous dimension matrix of the twist-3 singlet operators by computing the off-shell Green's functions. As an application, we investigate the Q^2-evolution of g_2(x, Q^{2}) for the lowest moment case, and discuss its experimental implication.
[ { "created": "Fri, 24 Oct 1997 10:02:55 GMT", "version": "v1" }, { "created": "Mon, 24 Nov 1997 10:22:03 GMT", "version": "v2" } ]
2007-05-23
[ [ "Kodaira", "Jiro", "", "Hiroshima Univ." ], [ "Nasuno", "Takashi", "", "Hiroshima Univ." ], [ "Tochimura", "Hiroshi", "", "Hiroshima Univ." ], [ "Tanaka", "Kazuhiro", "", "Juntendo Univ." ], [ "Yasui", "Yoshiaki", "", "RIKEN-BNL" ] ]
We investigate the nucleon's transverse spin-dependent structure function g_2(x, Q^2) in the framework of the operator product expansion and the renormalization group. We construct the complete set of the twist-3 operators for the flavor singlet channel, and give the relations among them. We develop an efficient, covariant approach to derive the anomalous dimension matrix of the twist-3 singlet operators by computing the off-shell Green's functions. As an application, we investigate the Q^2-evolution of g_2(x, Q^{2}) for the lowest moment case, and discuss its experimental implication.
1008.1052
Bennie F. L. Ward
B.F.L. Ward (1) ((1) Department of Physics, Baylor University, Waco, TX, USA)
"Low" Energy GUTs
9 pages
The Open Jour. Nucl. Part. Phys. 5 (2012) 5
10.2174/1874415X01205010005
BU-HEPP-10-03
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce a new approach to the subject of grand unification which allows the GUT scale to be small, \lesssim 200 TeV, so that it is within the reach of {\em conceivable} laboratory accelerated colliding beam devices. Central to the approach is a novel abstraction of the heterotic string symmetry group physics ideas to render baryon number violating effects small enough to have escaped detection to date.
[ { "created": "Thu, 5 Aug 2010 19:47:55 GMT", "version": "v1" } ]
2015-05-19
[ [ "Ward", "B. F. L.", "" ] ]
We introduce a new approach to the subject of grand unification which allows the GUT scale to be small, \lesssim 200 TeV, so that it is within the reach of {\em conceivable} laboratory accelerated colliding beam devices. Central to the approach is a novel abstraction of the heterotic string symmetry group physics ideas to render baryon number violating effects small enough to have escaped detection to date.
2012.12701
Greger Torgrimsson
Greger Torgrimsson
Loops and polarization in strong-field QED
29 pages, 5 figures
null
10.1088/1367-2630/abf274
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a previous paper we showed how higher-order strong-field-QED processes in long laser pulses can be approximated by multiplying sequences of "strong-field Mueller matrices". We obtained expressions that are valid for arbitrary field shape and polarization. In this paper we derive practical approximations of these Mueller matrices in the locally-constant- and the locally-monochromatic-field regimes. We allow for arbitrary laser polarization as well as arbitrarily polarized initial and final particles. The spin and polarization can also change due to loop contributions (the mass operator for electrons and the polarization operator for photons). We derive Mueller matrices for these as well.
[ { "created": "Wed, 23 Dec 2020 14:28:52 GMT", "version": "v1" } ]
2021-07-07
[ [ "Torgrimsson", "Greger", "" ] ]
In a previous paper we showed how higher-order strong-field-QED processes in long laser pulses can be approximated by multiplying sequences of "strong-field Mueller matrices". We obtained expressions that are valid for arbitrary field shape and polarization. In this paper we derive practical approximations of these Mueller matrices in the locally-constant- and the locally-monochromatic-field regimes. We allow for arbitrary laser polarization as well as arbitrarily polarized initial and final particles. The spin and polarization can also change due to loop contributions (the mass operator for electrons and the polarization operator for photons). We derive Mueller matrices for these as well.
hep-ph/0304002
Pavel Nadolsky
P.M. Nadolsky, C.-P. Yuan
Single-spin asymmetries with weak bosons at RHIC
38 pages, 17 figures; a version with high-resolution figures is available online at http://hep.pa.msu.edu/~nadolsky/RhicBos/index.html#RhicBos_references
Nucl.Phys.B666:31-55,2003
10.1016/S0550-3213(03)00455-3
null
hep-ph
null
In order to measure spin-dependent parton distributions in production of weak bosons using the non-hermetic detectors of the Relativistic Heavy Ion Collider, an accurate model for distributions of charged leptons from the W boson decay is needed. We discuss the predictions for production and decay of the W bosons based on a calculation for resummation of large logarithmic contributions originating from multiple soft gluon radiation. We compare the predictions for the spin-dependent resummed cross sections with the corresponding next-to-leading order results. We show that the lepton-level asymmetries can be reliably predicted by the resummation calculation and directly compared to the experimental data. A program for the numerical analysis of such cross sections in $\gamma ^{*}, W^{\pm},$ and $Z^{0}$ boson production is also presented.
[ { "created": "Tue, 1 Apr 2003 20:01:56 GMT", "version": "v1" } ]
2008-11-26
[ [ "Nadolsky", "P. M.", "" ], [ "Yuan", "C. -P.", "" ] ]
In order to measure spin-dependent parton distributions in production of weak bosons using the non-hermetic detectors of the Relativistic Heavy Ion Collider, an accurate model for distributions of charged leptons from the W boson decay is needed. We discuss the predictions for production and decay of the W bosons based on a calculation for resummation of large logarithmic contributions originating from multiple soft gluon radiation. We compare the predictions for the spin-dependent resummed cross sections with the corresponding next-to-leading order results. We show that the lepton-level asymmetries can be reliably predicted by the resummation calculation and directly compared to the experimental data. A program for the numerical analysis of such cross sections in $\gamma ^{*}, W^{\pm},$ and $Z^{0}$ boson production is also presented.
hep-ph/0309208
Loretta Robinette
Aharon Casher and Shmuel Nussinov (Tel Aviv University and Univ. of South Carolina)
The Narrow Theta(1543)--A QCD Dilemma: Tube or Not Tube?
9 pages, 2 figures Please note that Nussinov has previously submitted entries to the ArXives through assistance of other individuals. The submitter of this paper (robinet@physics.umd.edu) is L. Robinette, administrative assistant to the Maryland TQHN Group; comments should be addressed to nussinov@ccsg.tau.ac.il
Phys.Lett. B578 (2004) 124-132
10.1016/j.physletb.2003.10.041
null
hep-ph
null
We argue that a width of less than MeV of the new Theta resonance is inconsistent with the observed ratio of resonance and background events in the various photon initiated experiments if the latter can be described by K, K*, etc., exchange. An evaluation of the Feynman diagrams which were believed to be relevant is presented and supports the general claim in the one case where a cross section has been given by the experimental group. More detailed arguments based on the flux tube model explaining the narrow widths and the apparent conflict with the production rates are presented. We predict narrow Tetra-quarks at mass ~ O(1-1.2 GeV) which the analysis of LEAR may have missed.
[ { "created": "Wed, 17 Sep 2003 19:36:24 GMT", "version": "v1" } ]
2015-06-25
[ [ "Casher", "Aharon", "", "Tel Aviv University and Univ. of\n South Carolina" ], [ "Nussinov", "Shmuel", "", "Tel Aviv University and Univ. of\n South Carolina" ] ]
We argue that a width of less than MeV of the new Theta resonance is inconsistent with the observed ratio of resonance and background events in the various photon initiated experiments if the latter can be described by K, K*, etc., exchange. An evaluation of the Feynman diagrams which were believed to be relevant is presented and supports the general claim in the one case where a cross section has been given by the experimental group. More detailed arguments based on the flux tube model explaining the narrow widths and the apparent conflict with the production rates are presented. We predict narrow Tetra-quarks at mass ~ O(1-1.2 GeV) which the analysis of LEAR may have missed.
0806.4555
Richard F. Lebed
Christopher D. Carone, Richard F. Lebed
Minimal Lee-Wick Extension of the Standard Model
13 pages, ReVTeX, 3 eps figures (v4: numerical error corrected leading to stronger bounds)
Phys.Lett.B668:221-225,2008
10.1016/j.physletb.2008.08.050
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a minimal Lee-Wick (LW) extension to the Standard Model in which the fields providing the most important contributions to the cancellation of quadratic divergences are the lightest. Partners to the SU(2) gauge bosons, Higgs, top quark, and left-handed bottom quark are retained in the low-energy effective theory, which is valid up to approximately 10 TeV; the remaining LW partners appear above this cutoff and complete the theory in the ultraviolet. We determine the constraints on the low-energy spectrum from the electroweak parameters S and T, and find LW states within the kinematic reach of the LHC at the 95% confidence level.
[ { "created": "Fri, 27 Jun 2008 16:16:55 GMT", "version": "v1" }, { "created": "Sat, 28 Jun 2008 18:47:31 GMT", "version": "v2" }, { "created": "Wed, 2 Jul 2008 21:36:35 GMT", "version": "v3" }, { "created": "Thu, 10 Jul 2008 02:01:02 GMT", "version": "v4" } ]
2008-11-26
[ [ "Carone", "Christopher D.", "" ], [ "Lebed", "Richard F.", "" ] ]
We consider a minimal Lee-Wick (LW) extension to the Standard Model in which the fields providing the most important contributions to the cancellation of quadratic divergences are the lightest. Partners to the SU(2) gauge bosons, Higgs, top quark, and left-handed bottom quark are retained in the low-energy effective theory, which is valid up to approximately 10 TeV; the remaining LW partners appear above this cutoff and complete the theory in the ultraviolet. We determine the constraints on the low-energy spectrum from the electroweak parameters S and T, and find LW states within the kinematic reach of the LHC at the 95% confidence level.
0809.3999
Tonnis ter Veldhuis
T.E. Clark, S.T. Love, Muneto Nitta, T. ter Veldhuis, and C. Xiong
Colliders and Brane Vector Phenomenology
12 pages, 13 figures
Phys.Rev.D78:115004,2008
10.1103/PhysRevD.78.115004
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Brane world oscillations manifest themselves as massive vector gauge fields. Their coupling to the Standard Model is deduced using the method of nonlinear realizations of the spontaneously broken higher dimensional space-time symmetries. Brane vectors are stable and weakly interacting, and therefore escape particle detectors unnoticed. LEP and Tevatron data on the production of a single photon in conjunction with missing energy are used to delineate experimentally excluded regions of brane vector parameter space. The additional region of parameter space accessible to the LHC as well as a future lepton linear collider is also determined by means of this process.
[ { "created": "Tue, 23 Sep 2008 19:43:44 GMT", "version": "v1" } ]
2008-12-09
[ [ "Clark", "T. E.", "" ], [ "Love", "S. T.", "" ], [ "Nitta", "Muneto", "" ], [ "ter Veldhuis", "T.", "" ], [ "Xiong", "C.", "" ] ]
Brane world oscillations manifest themselves as massive vector gauge fields. Their coupling to the Standard Model is deduced using the method of nonlinear realizations of the spontaneously broken higher dimensional space-time symmetries. Brane vectors are stable and weakly interacting, and therefore escape particle detectors unnoticed. LEP and Tevatron data on the production of a single photon in conjunction with missing energy are used to delineate experimentally excluded regions of brane vector parameter space. The additional region of parameter space accessible to the LHC as well as a future lepton linear collider is also determined by means of this process.
2008.06918
Simon Knapen
Jared A. Evans, Abhijith Gandrakota, Simon Knapen, Hardik Routray
Searching for exotic B meson decays with the CMS L1 track trigger
7 pages, 5 figures
Phys. Rev. D 103, 015026 (2021)
10.1103/PhysRevD.103.015026
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The CMS phase II track trigger may allow for a displaced dimuon vertex trigger with qualitatively lower $p_T$ thresholds than existing dimuon triggers. With this technique, we show that the CMS reach for exotic $B$-meson decays involving a displaced dimuon resonance, such as a light, Higgs-mixed scalar, can be competitive with that of LHCb and Belle II.
[ { "created": "Sun, 16 Aug 2020 14:31:36 GMT", "version": "v1" } ]
2021-01-27
[ [ "Evans", "Jared A.", "" ], [ "Gandrakota", "Abhijith", "" ], [ "Knapen", "Simon", "" ], [ "Routray", "Hardik", "" ] ]
The CMS phase II track trigger may allow for a displaced dimuon vertex trigger with qualitatively lower $p_T$ thresholds than existing dimuon triggers. With this technique, we show that the CMS reach for exotic $B$-meson decays involving a displaced dimuon resonance, such as a light, Higgs-mixed scalar, can be competitive with that of LHCb and Belle II.
0803.2385
Jonathan Rosner
Bhubanjyoti Bhattacharya and Jonathan L. Rosner
Flavor symmetry and decays of charmed mesons to pairs of light pseudoscalars
12 pages, 5 figures, to be submitted to Phys. Rev. D
Phys.Rev.D77:114020,2008
10.1103/PhysRevD.77.114020
EFI 08-05
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
New data on the decays of the charmed particles $D^0$, $D^+$, and $D_s$ to pairs of light pseudoscalar mesons $P$ allow the testing of flavor symmetry and the extraction of key amplitudes. Information on relative strong phases is obtained. One sees evidence for the expected interference between Cabibbo-favored and doubly-Cabibbo-suppressed decays in the differing patterns of $D^0 \to K_{S,L} \pi^0$ and $D^+ \to K_{S,L} \pi^+$ decays.
[ { "created": "Mon, 17 Mar 2008 15:04:35 GMT", "version": "v1" } ]
2008-11-26
[ [ "Bhattacharya", "Bhubanjyoti", "" ], [ "Rosner", "Jonathan L.", "" ] ]
New data on the decays of the charmed particles $D^0$, $D^+$, and $D_s$ to pairs of light pseudoscalar mesons $P$ allow the testing of flavor symmetry and the extraction of key amplitudes. Information on relative strong phases is obtained. One sees evidence for the expected interference between Cabibbo-favored and doubly-Cabibbo-suppressed decays in the differing patterns of $D^0 \to K_{S,L} \pi^0$ and $D^+ \to K_{S,L} \pi^+$ decays.
hep-ph/0606230
Alexander Dolgov
A.D. Dolgov
Cosmology and New Physics
37 pages, 5 figures; lectures presented at 9th International Moscow School of Physics (34th ITEP Winter School)
Phys.Atom.Nucl.71:651-670,2008
10.1134/S1063778808040066
null
hep-ph
null
A comparison of the standard models in particle physics and in cosmology demonstrates that they are not compatible, though both are well established. Basics of modern cosmology are briefly reviewed. It is argued that the measurements of the main cosmological parameters are achieved through many independent physical phenomena and this minimizes possible interpretation errors. It is shown that astronomy demands new physics beyond the frameworks of the (minimal) standard model in particle physics. More revolutionary modifications of the basic principles of the theory are also discussed.
[ { "created": "Wed, 21 Jun 2006 14:49:25 GMT", "version": "v1" } ]
2008-11-26
[ [ "Dolgov", "A. D.", "" ] ]
A comparison of the standard models in particle physics and in cosmology demonstrates that they are not compatible, though both are well established. Basics of modern cosmology are briefly reviewed. It is argued that the measurements of the main cosmological parameters are achieved through many independent physical phenomena and this minimizes possible interpretation errors. It is shown that astronomy demands new physics beyond the frameworks of the (minimal) standard model in particle physics. More revolutionary modifications of the basic principles of the theory are also discussed.
hep-ph/9904408
Andrzej J. Buras
S. Bosch, A.J. Buras, M. Gorbahn, S. J\"ager, M. Jamin, M.E. Lautenbacher, L. Silvestrini
Standard Model Confronting New Results for epsilon'/epsilon
main latex-file, 4 figures and related latex files, 47 pages
Nucl.Phys.B565:3-37,2000
10.1016/S0550-3213(99)00694-X
TUM-HEP-347/99, LMU 06/99
hep-ph
null
We analyze the CP violating ratio \epe=epsilon'/epsilon in the Standard Model in view of the new KTeV results. We review the present status of the most important non-perturbative parameters B_6, B_8, B_K and of the strange quark mass m_s. We also briefly discuss the issues of final state interactions and renormalization scheme dependence. Updating the values of the CKM parameters, of m_t and Lambda (MSbar) and using Gaussian errors for the experimental input and flat distributions for the theoretical parameters we find \epe substantially below the NA31 and KTeV data: \epe= (7.7^{+6.0}_{-3.5}) 10^{-4} and \epe= (5.2^{+4.6}_{-2.7}) 10^{-4} in the NDR and HV renormalization schemes respectively. A simple scanning of all input parameters gives on the other hand 1.05 10^{-4} < \epe < 28.8 10^{-4} and 0.26 10^{-4} < \epe < 22.0 10^{-4} respectively. Analyzing the dependence on various parameters we find that only for extreme values of B_6, B_8 and m_s and suitable values of CKM parameters and Lambda(MSbar), the ratio \epe can be made consistent with data. We analyze the impact of these data on the lower bounds for Im(V_{td}V_{ts}^*), Br(K_L to pi^0 nu barnu), Br(K_L to pi^0e^+e^-)_{dir} and on tan(beta) in the Two Higgs Doublet Model II.
[ { "created": "Tue, 20 Apr 1999 16:30:40 GMT", "version": "v1" } ]
2008-11-26
[ [ "Bosch", "S.", "" ], [ "Buras", "A. J.", "" ], [ "Gorbahn", "M.", "" ], [ "Jäger", "S.", "" ], [ "Jamin", "M.", "" ], [ "Lautenbacher", "M. E.", "" ], [ "Silvestrini", "L.", "" ] ]
We analyze the CP violating ratio \epe=epsilon'/epsilon in the Standard Model in view of the new KTeV results. We review the present status of the most important non-perturbative parameters B_6, B_8, B_K and of the strange quark mass m_s. We also briefly discuss the issues of final state interactions and renormalization scheme dependence. Updating the values of the CKM parameters, of m_t and Lambda (MSbar) and using Gaussian errors for the experimental input and flat distributions for the theoretical parameters we find \epe substantially below the NA31 and KTeV data: \epe= (7.7^{+6.0}_{-3.5}) 10^{-4} and \epe= (5.2^{+4.6}_{-2.7}) 10^{-4} in the NDR and HV renormalization schemes respectively. A simple scanning of all input parameters gives on the other hand 1.05 10^{-4} < \epe < 28.8 10^{-4} and 0.26 10^{-4} < \epe < 22.0 10^{-4} respectively. Analyzing the dependence on various parameters we find that only for extreme values of B_6, B_8 and m_s and suitable values of CKM parameters and Lambda(MSbar), the ratio \epe can be made consistent with data. We analyze the impact of these data on the lower bounds for Im(V_{td}V_{ts}^*), Br(K_L to pi^0 nu barnu), Br(K_L to pi^0e^+e^-)_{dir} and on tan(beta) in the Two Higgs Doublet Model II.
hep-ph/9505276
null
Stanley J. Brodsky and Felix Schlumpf
RELATIVISTIC CORRECTIONS TO THE ELECTROMAGNETIC AND AXIAL MOMENTS OF NUCLEI AND OTHER COMPOSITE SYSTEMS
10 pages, uuencoded postscript file. To obtain a copy of this paper, send e-mail to TECHPUB@SLAC.STANFORD.EDU and ask for it
Phys.Lett.B360:1-6,1995
10.1016/0370-2693(95)01135-D
SLAC-PUB-95-6860
hep-ph nucl-th
null
We calculate the electromagnetic and axial nuclear moments of the deuteron and triton as a function of their radius using a relativistic two-nucleon and three-nucleon model formulated on the light-cone. The results also provide an estimate of the nuclear binding corrections to helicity-dependent deep inelastic scattering sum rules. At large nucleon radius, the moments are given by the usual non-relativistic formulae modified by finite binding effects. At small radius, the moments take the canonical values given by the generalization of the Drell-Hearn-Gerasimov sum rule. In addition, as R-->0, the constituent helicities become completely disoriented, and the Gamow-Teller matrix element vanishes. Thus, in the pointlike limit MR-->0, the moments of a spin-one bound states coincide with the canonical couplings of elementary spin-one bosons of the Standard Model, mu=e/M, Q=-e/M^2, and g_A=0.
[ { "created": "Wed, 10 May 1995 22:06:56 GMT", "version": "v1" }, { "created": "Mon, 15 May 1995 15:35:10 GMT", "version": "v2" } ]
2009-09-11
[ [ "Brodsky", "Stanley J.", "" ], [ "Schlumpf", "Felix", "" ] ]
We calculate the electromagnetic and axial nuclear moments of the deuteron and triton as a function of their radius using a relativistic two-nucleon and three-nucleon model formulated on the light-cone. The results also provide an estimate of the nuclear binding corrections to helicity-dependent deep inelastic scattering sum rules. At large nucleon radius, the moments are given by the usual non-relativistic formulae modified by finite binding effects. At small radius, the moments take the canonical values given by the generalization of the Drell-Hearn-Gerasimov sum rule. In addition, as R-->0, the constituent helicities become completely disoriented, and the Gamow-Teller matrix element vanishes. Thus, in the pointlike limit MR-->0, the moments of a spin-one bound states coincide with the canonical couplings of elementary spin-one bosons of the Standard Model, mu=e/M, Q=-e/M^2, and g_A=0.
hep-ph/0203258
Krzysztof Golec-Biernat
J. Bartels, K. Golec-Biernat, H. Kowalski
A Modification of the Saturation Model: DGLAP evolution
20 pages with 10 ps figures. Published version with some corrections
Phys.Rev.D66:014001,2002
10.1103/PhysRevD.66.014001
null
hep-ph
null
We propose to modify the saturation model of Golec-Biernat and Wusthoff by including DGLAP evolution. We find considerable improvement for the total deep inelastic cross section, in particular in the large Q^2 region. The successful description of DIS diffraction is preserved.
[ { "created": "Wed, 27 Mar 2002 20:40:16 GMT", "version": "v1" }, { "created": "Fri, 5 Jul 2002 10:14:40 GMT", "version": "v2" } ]
2010-03-25
[ [ "Bartels", "J.", "" ], [ "Golec-Biernat", "K.", "" ], [ "Kowalski", "H.", "" ] ]
We propose to modify the saturation model of Golec-Biernat and Wusthoff by including DGLAP evolution. We find considerable improvement for the total deep inelastic cross section, in particular in the large Q^2 region. The successful description of DIS diffraction is preserved.
1709.08301
Dibyakrupa Sahoo
Dibyakrupa Sahoo, Hai-Yang Cheng, Cheng-Wei Chiang, C. S. Kim and Rahul Sinha
Prediction of the $CP$ asymmetry $C_{00}$ in $B^0 \to D^0\overline{D^0}$ decay
21 pages, 6 figures, accepted for publication in JHEP
null
10.1007/JHEP11(2017)087
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Of all $B \to D \overline{D}$ decays, the $B^0 \to D^0 \overline{D^0}$ decay has the smallest observed branching ratio as it takes place primarily via the suppressed $W$-exchange diagram. The $CP$ asymmetry for this mode is yet to be measured experimentally. By exploiting the relationship among the decay amplitudes of $B \to D\overline{D}$ decays (using isospin and topological amplitudes) we are able to relate the $CP$ asymmetries and branching ratios by a simple expression. This enables us to predict the $CP$ asymmetry $C_{00}$ in $B^0 \to D^0 \overline{D^0}$. While the predicted central values of $C_{00}$ are outside the physically allowed region, they are currently associated with large uncertainties owing to the large errors in the measurements of the $B^0 \to D^0 \overline{D^0}$ branching ratio ($B_{00}$), the other $CP$ asymmetries $C_{+-}$ (of $B^0 \to D^+ D^-$) and $A_{\text{CP}}$ (of $B^+ \to D^+ \overline{D^0}$). With a precise determination of $B_{00}$, $C_{+-}$ and $A_{\text{CP}}$, one can use our analytical result to predict $C_{00}$ with a reduced error and compare it with the experimental measurement when it becomes available. The correlation between $B_{00}$ and $C_{00}$ is an interesting aspect that can be probed in ongoing and future particle physics experiments such as LHCb and Belle II.
[ { "created": "Mon, 25 Sep 2017 03:24:07 GMT", "version": "v1" }, { "created": "Fri, 10 Nov 2017 03:08:29 GMT", "version": "v2" } ]
2017-11-27
[ [ "Sahoo", "Dibyakrupa", "" ], [ "Cheng", "Hai-Yang", "" ], [ "Chiang", "Cheng-Wei", "" ], [ "Kim", "C. S.", "" ], [ "Sinha", "Rahul", "" ] ]
Of all $B \to D \overline{D}$ decays, the $B^0 \to D^0 \overline{D^0}$ decay has the smallest observed branching ratio as it takes place primarily via the suppressed $W$-exchange diagram. The $CP$ asymmetry for this mode is yet to be measured experimentally. By exploiting the relationship among the decay amplitudes of $B \to D\overline{D}$ decays (using isospin and topological amplitudes) we are able to relate the $CP$ asymmetries and branching ratios by a simple expression. This enables us to predict the $CP$ asymmetry $C_{00}$ in $B^0 \to D^0 \overline{D^0}$. While the predicted central values of $C_{00}$ are outside the physically allowed region, they are currently associated with large uncertainties owing to the large errors in the measurements of the $B^0 \to D^0 \overline{D^0}$ branching ratio ($B_{00}$), the other $CP$ asymmetries $C_{+-}$ (of $B^0 \to D^+ D^-$) and $A_{\text{CP}}$ (of $B^+ \to D^+ \overline{D^0}$). With a precise determination of $B_{00}$, $C_{+-}$ and $A_{\text{CP}}$, one can use our analytical result to predict $C_{00}$ with a reduced error and compare it with the experimental measurement when it becomes available. The correlation between $B_{00}$ and $C_{00}$ is an interesting aspect that can be probed in ongoing and future particle physics experiments such as LHCb and Belle II.
1801.09582
Fu-Sheng Yu
Peng-Fei Guo, Di Wang, Fu-Sheng Yu
Strange Axial-vector Mesons in D Meson Decays
18 pages, 7 tables. Published version
Nuclear Physics Review, 36, 125 (2019)
10.11804/NuclPhysRev.36.02.125
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The nature of strange axial-vector mesons are not well understood and can be investigated in $D$ meson decays. In this work, it is found that the experimental data of $D^0\rightarrow K^\pm K^\mp_1(1270)(\to \rho K \,\,\text{or}\,\,K^{*}\pi)$ in the $D^0\to K^+K^-\pi^+\pi^-$ mode, disagree with the equality relation under the narrow width approximation and $CP$ conservation of strong decays. Considering more other results of $K_1(1270)$ decays, the data of $\mathcal{B}(D^0\rightarrow K^-K^+_1(1270)(\to K^{*0}\pi^+))$ is probably overestimated by one order of magnitude. We then calculate the branching fractions of the corresponding processes with $K_1(1400)$ in the factorization approach, and find $\mathcal{B}(D^0\rightarrow K^-K^+_1(1400)(\to K^{*0}\pi^+))$ is comparable to the predicted $\mathcal{B}(D^0\rightarrow K^-K^+_1(1270)(\to K^{*0}\pi^+))$ using the equality relation. Besides, we suggest to measure the ratios between $K_1(1270)\to \rho K$ and $K^*\pi$ or to test the equality relations in other $D$ meson decay modes.
[ { "created": "Mon, 29 Jan 2018 15:39:07 GMT", "version": "v1" }, { "created": "Wed, 1 Jan 2020 10:04:11 GMT", "version": "v2" } ]
2020-01-03
[ [ "Guo", "Peng-Fei", "" ], [ "Wang", "Di", "" ], [ "Yu", "Fu-Sheng", "" ] ]
The nature of strange axial-vector mesons are not well understood and can be investigated in $D$ meson decays. In this work, it is found that the experimental data of $D^0\rightarrow K^\pm K^\mp_1(1270)(\to \rho K \,\,\text{or}\,\,K^{*}\pi)$ in the $D^0\to K^+K^-\pi^+\pi^-$ mode, disagree with the equality relation under the narrow width approximation and $CP$ conservation of strong decays. Considering more other results of $K_1(1270)$ decays, the data of $\mathcal{B}(D^0\rightarrow K^-K^+_1(1270)(\to K^{*0}\pi^+))$ is probably overestimated by one order of magnitude. We then calculate the branching fractions of the corresponding processes with $K_1(1400)$ in the factorization approach, and find $\mathcal{B}(D^0\rightarrow K^-K^+_1(1400)(\to K^{*0}\pi^+))$ is comparable to the predicted $\mathcal{B}(D^0\rightarrow K^-K^+_1(1270)(\to K^{*0}\pi^+))$ using the equality relation. Besides, we suggest to measure the ratios between $K_1(1270)\to \rho K$ and $K^*\pi$ or to test the equality relations in other $D$ meson decay modes.
1312.7641
Mariko Kikuchi
Mariko Kikuchi
Radiative corrections to the Higgs couplings in the triplet model
6 pages, 2 eps figures, Proceedings of LC13: Exploring QCD from the infrared regime to heavy flavour scales at B-factories, the LHC and a Linear Collider, 16-20 September, 2013, ECT*, Villa Tambosi, Vallazzano(TN), Italy. arXiv admin note: text overlap with arXiv:1305.0109
null
10.1393/ncc/i2014-11745-y
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The feature of extended Higgs models can appear in the pattern of deviations from the Standard Model (SM) predictions in coupling constants of the SM-like Higgs boson ($h$). We can thus discriminate extended Higgs models by precisely measuring the pattern of deviations in the coupling constants of $h$, even when extra bosons are not found directly. In order to compare the theoretical predictions to the future precision data at the ILC, we must evaluate the theoretical predictions with radiative corrections in various extended Higgs models. In this talk, we give our comprehensive study for radiative corrections to various Higgs boson couplings of $h$ in the minimal Higgs triplet model (HTM). First, we define renormalization conditions in the model, and we calculate the Higgs coupling; $g\gamma\gamma, hWW, hZZ$ and $hhh$ at the one loop level. We then evaluate deviations in coupling constants of the SM-like Higgs boson from the predictions in the SM. We find that one-loop contributions to these couplings are substantial as compared to their expected measurement accuracies at the ILC. Therefore the HTM has a possibility to be distinguished from the other models by comparing the pattern of deviations in the Higgs boson couplings.
[ { "created": "Mon, 30 Dec 2013 07:05:48 GMT", "version": "v1" } ]
2022-03-02
[ [ "Kikuchi", "Mariko", "" ] ]
The feature of extended Higgs models can appear in the pattern of deviations from the Standard Model (SM) predictions in coupling constants of the SM-like Higgs boson ($h$). We can thus discriminate extended Higgs models by precisely measuring the pattern of deviations in the coupling constants of $h$, even when extra bosons are not found directly. In order to compare the theoretical predictions to the future precision data at the ILC, we must evaluate the theoretical predictions with radiative corrections in various extended Higgs models. In this talk, we give our comprehensive study for radiative corrections to various Higgs boson couplings of $h$ in the minimal Higgs triplet model (HTM). First, we define renormalization conditions in the model, and we calculate the Higgs coupling; $g\gamma\gamma, hWW, hZZ$ and $hhh$ at the one loop level. We then evaluate deviations in coupling constants of the SM-like Higgs boson from the predictions in the SM. We find that one-loop contributions to these couplings are substantial as compared to their expected measurement accuracies at the ILC. Therefore the HTM has a possibility to be distinguished from the other models by comparing the pattern of deviations in the Higgs boson couplings.
1407.5078
Leonard Gamberg
Leonard Gamberg, Zhong-Bo Kang, Andreas Metz, Daniel Pitonyak, and Alexei Prokudin
Left-right spin asymmetry in $\ell N^\uparrow \to h X$
14 pages, 12 figures: minor edits, matches published version
Phys. Rev. D 90, 074012 (2014)
10.1103/PhysRevD.90.074012
JLAB-THY-14-1915, RBRC-1084
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the inclusive production of hadrons in lepton-nucleon scattering. For a transversely polarized nucleon this reaction shows a left-right azimuthal asymmetry, which we compute in twist-3 collinear factorization at leading order in perturbation theory. All non-perturbative parton correlators of the calculation are fixed through information from other hard processes. Our results for the left-right asymmetry agree in sign with recent data for charged pion production from the HERMES Collaboration and from Jefferson Lab. However, the magnitude of the computed asymmetries tends to be larger than the data. Potential reasons for this outcome are identified. We also give predictions for future experiments and highlight in particular the unique opportunities at an Electron Ion Collider.
[ { "created": "Fri, 18 Jul 2014 18:36:54 GMT", "version": "v1" }, { "created": "Fri, 10 Oct 2014 18:14:51 GMT", "version": "v2" } ]
2014-10-13
[ [ "Gamberg", "Leonard", "" ], [ "Kang", "Zhong-Bo", "" ], [ "Metz", "Andreas", "" ], [ "Pitonyak", "Daniel", "" ], [ "Prokudin", "Alexei", "" ] ]
We consider the inclusive production of hadrons in lepton-nucleon scattering. For a transversely polarized nucleon this reaction shows a left-right azimuthal asymmetry, which we compute in twist-3 collinear factorization at leading order in perturbation theory. All non-perturbative parton correlators of the calculation are fixed through information from other hard processes. Our results for the left-right asymmetry agree in sign with recent data for charged pion production from the HERMES Collaboration and from Jefferson Lab. However, the magnitude of the computed asymmetries tends to be larger than the data. Potential reasons for this outcome are identified. We also give predictions for future experiments and highlight in particular the unique opportunities at an Electron Ion Collider.
hep-ph/0103214
Arthur Hebecker
A. Hebecker and J. March-Russell
Randall-Sundrum II Cosmology, AdS/CFT, and the Bulk Black Hole
20 pages, LaTeX, v4: numerical error corrected, qualitative conclusions unchanged
Nucl.Phys. B608 (2001) 375-393
10.1016/S0550-3213(01)00286-3
CERN-TH/2001-78
hep-ph gr-qc hep-th
null
We analyse the cosmology of a brane world model where a single brane carrying the standard model fields forms the boundary of a 5-dimensional AdS bulk (the Randall-Sundrum II scenario). We focus on the thermal radiation of bulk gravitons, the formation of the bulk black hole, and the holographic AdS/CFT definition of the RSII theory. Our detailed calculation of bulk radiation reduces previous estimates to a phenomenologically acceptable, although potentially visible level. In late cosmology, in which the Friedmann equation depends linearly on the energy density \rho, only about 0.5% of energy density is lost to the black hole or, equivalently, to the `dark radiation' (\Omega_{d,N} \simeq 0.005 at nucleosynthesis). The preceding, unconventional \rho^2 period can produce up to 5% dark radiation (\Omega_{d,N} <\sim 0.05). The AdS/CFT correspondence provides an equivalent description of late RSII cosmology. We show how the AdS/CFT formulation can reproduce the \rho^2 correction to the standard treatment at low matter density. However, the 4-dimensional effective theory of CFT + gravity breaks down due to higher curvature terms for energy densities where \rho^2 behaviour in the Friedmann equation is usually predicted. We emphasize that, in going beyond this energy density, the microscopic formulation of the theory becomes essential. For example, the pure AdS_5 and string-motivated AdS_5\timesS^5 definitions differ in their cosmological implications.
[ { "created": "Tue, 20 Mar 2001 15:07:15 GMT", "version": "v1" }, { "created": "Thu, 22 Mar 2001 17:20:07 GMT", "version": "v2" }, { "created": "Mon, 9 Jul 2001 17:09:19 GMT", "version": "v3" }, { "created": "Wed, 2 Jul 2003 13:51:19 GMT", "version": "v4" } ]
2009-11-07
[ [ "Hebecker", "A.", "" ], [ "March-Russell", "J.", "" ] ]
We analyse the cosmology of a brane world model where a single brane carrying the standard model fields forms the boundary of a 5-dimensional AdS bulk (the Randall-Sundrum II scenario). We focus on the thermal radiation of bulk gravitons, the formation of the bulk black hole, and the holographic AdS/CFT definition of the RSII theory. Our detailed calculation of bulk radiation reduces previous estimates to a phenomenologically acceptable, although potentially visible level. In late cosmology, in which the Friedmann equation depends linearly on the energy density \rho, only about 0.5% of energy density is lost to the black hole or, equivalently, to the `dark radiation' (\Omega_{d,N} \simeq 0.005 at nucleosynthesis). The preceding, unconventional \rho^2 period can produce up to 5% dark radiation (\Omega_{d,N} <\sim 0.05). The AdS/CFT correspondence provides an equivalent description of late RSII cosmology. We show how the AdS/CFT formulation can reproduce the \rho^2 correction to the standard treatment at low matter density. However, the 4-dimensional effective theory of CFT + gravity breaks down due to higher curvature terms for energy densities where \rho^2 behaviour in the Friedmann equation is usually predicted. We emphasize that, in going beyond this energy density, the microscopic formulation of the theory becomes essential. For example, the pure AdS_5 and string-motivated AdS_5\timesS^5 definitions differ in their cosmological implications.
1007.4716
A. F. W. van Hameren
A. van Hameren
OneLOop: for the evaluation of one-loop scalar functions
20 pages
Comput.Phys.Commun.182:2427-2438,2011
10.1016/j.cpc.2011.06.011
IFJPAN-IV-2010-7
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
OneLOop is a program to evaluate the one-loop scalar 1-point, 2-point, 3-point and 4-point functions, for all kinematical configurations relevant for collider-physics, and for any non-positive imaginary parts of the internal squared masses. It deals with all UV and IR divergences within dimensional regularization. Furthermore, it provides routines to evaluate these functions using straightforward numerical integration.
[ { "created": "Tue, 27 Jul 2010 13:30:24 GMT", "version": "v1" } ]
2011-08-04
[ [ "van Hameren", "A.", "" ] ]
OneLOop is a program to evaluate the one-loop scalar 1-point, 2-point, 3-point and 4-point functions, for all kinematical configurations relevant for collider-physics, and for any non-positive imaginary parts of the internal squared masses. It deals with all UV and IR divergences within dimensional regularization. Furthermore, it provides routines to evaluate these functions using straightforward numerical integration.
1805.01473
Daniele Teresi
Thomas Hambye, Alessandro Strumia, Daniele Teresi
Super-cool Dark Matter
20 pages, 5 figures. Journal version
JHEP 1808 (2018) 188
10.1007/JHEP08(2018)188
ULB-TH/18-06, CERN-TH-2018-110, IFUP-TH/2018
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In dimension-less theories of dynamical generation of the weak scale, the Universe can undergo a period of low-scale inflation during which all particles are massless and super-cool. This leads to a new mechanism of generation of the cosmological Dark Matter (DM) relic density: super-cooling can easily suppress the amount of DM to the desired level. This is achieved for TeV-scale DM, if super-cooling ends when quark condensates form at the QCD phase transition. Along this scenario, the baryon asymmetry can be generated either at the phase transition or through leptogenesis. We show that the above mechanism takes place in old and new dimension-less models.
[ { "created": "Thu, 3 May 2018 18:00:01 GMT", "version": "v1" }, { "created": "Tue, 28 Aug 2018 16:24:26 GMT", "version": "v2" } ]
2018-09-10
[ [ "Hambye", "Thomas", "" ], [ "Strumia", "Alessandro", "" ], [ "Teresi", "Daniele", "" ] ]
In dimension-less theories of dynamical generation of the weak scale, the Universe can undergo a period of low-scale inflation during which all particles are massless and super-cool. This leads to a new mechanism of generation of the cosmological Dark Matter (DM) relic density: super-cooling can easily suppress the amount of DM to the desired level. This is achieved for TeV-scale DM, if super-cooling ends when quark condensates form at the QCD phase transition. Along this scenario, the baryon asymmetry can be generated either at the phase transition or through leptogenesis. We show that the above mechanism takes place in old and new dimension-less models.
1605.06515
Stefano Forte
The NNPDF Collaboration: Richard D.Ball, Valerio Bertone, Marco Bonvini, Stefano Carrazza, Stefano Forte, Alberto Guffanti, Nathan P. Hartland, Juan Rojo and Luca Rottoli
A Determination of the Charm Content of the Proton
46 pages, 32 figures. Final version, to be published in EPJC. Sections 3.2, 3.3, 3.4 and conclusions substantially rewritten and improved. Figs 11 and 14 improved, figs 10, 13, 16 added. Last typos fixed
null
null
Edinburgh 2016/06, CERN-TH-2016-087, OUTP-16-03P, TIF-UNIMI-2016-3
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an unbiased determination of the charm content of the proton, in which the charm parton distribution function (PDF) is parametrized on the same footing as the light quarks and the gluon in a global PDF analysis. This determination relies on the calculation of deep-inelastic structure functions in the FONLL scheme, generalized to account for massive charm-initiated contributions. In contrast to the usual situation in which the charm PDF is assumed to be generated perturbatively by pair radiation off gluons and light quarks, vanishing at a scale set by the value of the charm mass m_c, we find that the fitted charm PDF vanishes within uncertainties at a scale Q~1.5 GeV for all x<~0.1, independent of the value of m_c used in the coefficient functions. We also find some evidence that the charm PDF at large x>~0.1 and low scales does not vanish, but rather has an "intrinsic" component, very weakly scale dependent and almost independent of the value of m_c, carrying about 1% of the total momentum of the proton. The uncertainties in all other PDFs are only slightly increased by the inclusion of fitted charm, while the dependence of these PDFs on m_c is significantly reduced. When the EMC charm structure function dataset is included, it is well described by the fit, and PDF uncertainties in the fitted charm PDF are significantly reduced, though we verify that excluding the EMC data does not qualitatively modify any of our findings. The increased stability with respect to m_c persists at high scales and is the main implication of our results for LHC phenomenology. Fitting the charm PDF modifies the predictions for processes such as high p_T and large rapidity charm pair production and Z+c production, and thus we expect that future LHC data will further constrain the charm content of the proton.
[ { "created": "Fri, 20 May 2016 20:02:31 GMT", "version": "v1" }, { "created": "Mon, 21 Nov 2016 21:56:17 GMT", "version": "v2" }, { "created": "Wed, 23 Nov 2016 15:35:34 GMT", "version": "v3" } ]
2016-11-24
[ [ "The NNPDF Collaboration", "", "" ], [ "Ball", "Richard D.", "" ], [ "Bertone", "Valerio", "" ], [ "Bonvini", "Marco", "" ], [ "Carrazza", "Stefano", "" ], [ "Forte", "Stefano", "" ], [ "Guffanti", "Alberto", "" ], [ "Hartland", "Nathan P.", "" ], [ "Rojo", "Juan", "" ], [ "Rottoli", "Luca", "" ] ]
We present an unbiased determination of the charm content of the proton, in which the charm parton distribution function (PDF) is parametrized on the same footing as the light quarks and the gluon in a global PDF analysis. This determination relies on the calculation of deep-inelastic structure functions in the FONLL scheme, generalized to account for massive charm-initiated contributions. In contrast to the usual situation in which the charm PDF is assumed to be generated perturbatively by pair radiation off gluons and light quarks, vanishing at a scale set by the value of the charm mass m_c, we find that the fitted charm PDF vanishes within uncertainties at a scale Q~1.5 GeV for all x<~0.1, independent of the value of m_c used in the coefficient functions. We also find some evidence that the charm PDF at large x>~0.1 and low scales does not vanish, but rather has an "intrinsic" component, very weakly scale dependent and almost independent of the value of m_c, carrying about 1% of the total momentum of the proton. The uncertainties in all other PDFs are only slightly increased by the inclusion of fitted charm, while the dependence of these PDFs on m_c is significantly reduced. When the EMC charm structure function dataset is included, it is well described by the fit, and PDF uncertainties in the fitted charm PDF are significantly reduced, though we verify that excluding the EMC data does not qualitatively modify any of our findings. The increased stability with respect to m_c persists at high scales and is the main implication of our results for LHC phenomenology. Fitting the charm PDF modifies the predictions for processes such as high p_T and large rapidity charm pair production and Z+c production, and thus we expect that future LHC data will further constrain the charm content of the proton.
2307.06519
Patricio Gaete
Patricio Gaete and J. A. Helay\"el-Neto
Gambini-Pullin Electrodynamics as a scenario for Cherenkov radiation in QED vacuum
6 pages
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine the electromagnetic radiation produced by a moving charge in the QED vacuum that behaves as a dispersive medium characterized by a geometrical structure (discreteness/granularity) that emerges from loop quantum gravity. It is shown that the radiation is driven by the refractive vacuum the charged particle travels through reproducing the profile of the Cherenkov effect.
[ { "created": "Thu, 13 Jul 2023 01:47:49 GMT", "version": "v1" } ]
2023-07-14
[ [ "Gaete", "Patricio", "" ], [ "Helayël-Neto", "J. A.", "" ] ]
We examine the electromagnetic radiation produced by a moving charge in the QED vacuum that behaves as a dispersive medium characterized by a geometrical structure (discreteness/granularity) that emerges from loop quantum gravity. It is shown that the radiation is driven by the refractive vacuum the charged particle travels through reproducing the profile of the Cherenkov effect.
1209.6592
Jorgivan Dias Ms
J. M. Dias, R. M. Albuquerque, M. Nielsen and C. M. Zanetti
Y(4260) as a mixed charmonium-tetraquark state
9 pages, 6 figures
Phys.Rev. D86 (2012) 116012
10.1103/PhysRevD.86.116012
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Using the QCD sum rule approach we study the Y(4260) state assuming that it can be described by a mixed charmonium-tetraquark current with $J^{PC}=1^{--}$ quantum numbers. For the mixing angle around $\theta \approx (53.0\pm 0.5)^{0}$, we obtain a value for the mass which is in good agreement with the experimental mass of the Y(4260). However, for the decay width we find the value $\Ga_Y \approx (1.0\pm 0.2)$ MeV which is not compatible with the experimental value $\Ga \approx (88\pm 23)$ MeV. Therefore, we conclude that, although we can explain the mass of the Y(4260), this state cannot be described as a mixed charmonium-tetraquark state since, with this assumption, we can not explain its decay width.
[ { "created": "Fri, 28 Sep 2012 18:21:59 GMT", "version": "v1" } ]
2013-06-19
[ [ "Dias", "J. M.", "" ], [ "Albuquerque", "R. M.", "" ], [ "Nielsen", "M.", "" ], [ "Zanetti", "C. M.", "" ] ]
Using the QCD sum rule approach we study the Y(4260) state assuming that it can be described by a mixed charmonium-tetraquark current with $J^{PC}=1^{--}$ quantum numbers. For the mixing angle around $\theta \approx (53.0\pm 0.5)^{0}$, we obtain a value for the mass which is in good agreement with the experimental mass of the Y(4260). However, for the decay width we find the value $\Ga_Y \approx (1.0\pm 0.2)$ MeV which is not compatible with the experimental value $\Ga \approx (88\pm 23)$ MeV. Therefore, we conclude that, although we can explain the mass of the Y(4260), this state cannot be described as a mixed charmonium-tetraquark state since, with this assumption, we can not explain its decay width.
2101.03192
Jos\'e Angel Lesteiro Tejeda
J. A. Lesteiro-Tejeda, D. A. Ram\'irez-Zald\'ivar, C. E. Grac\'ia-Tr\'apaga, F. Guzm\'an-Mart\'inez
Spectroscopy of the tetraquark $c\bar{c}$-$c\bar{c}$ in a non-relativistic approach using a phenomenological QCD model
null
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Hadron spectroscopy is a powerful tool for testing the standard model and for the search of new physics. In this work, we create a tetraquark model from a di-meson interaction inspired by Jacobi coordinates. We consider mesons as thick points and quantify their interaction with the quark-antiquark interaction through a factor k (that takes approximately the value 2) in a central phenomenological potential, reducing the four-body problem finally to a one body equivalent problem. The eigenproblem is solved using a combination of the DVR method and perturbation theory in a C++ code. We obtain a mass spectrum for the tetraquark between 6 GeV and 8 GeV for the ground and first energy excitation level. Our calculation indicates that our system is compact and that the non-relativistic approach used in all our formalism is valid.
[ { "created": "Fri, 8 Jan 2021 19:27:54 GMT", "version": "v1" } ]
2021-01-12
[ [ "Lesteiro-Tejeda", "J. A.", "" ], [ "Ramírez-Zaldívar", "D. A.", "" ], [ "Gracía-Trápaga", "C. E.", "" ], [ "Guzmán-Martínez", "F.", "" ] ]
Hadron spectroscopy is a powerful tool for testing the standard model and for the search of new physics. In this work, we create a tetraquark model from a di-meson interaction inspired by Jacobi coordinates. We consider mesons as thick points and quantify their interaction with the quark-antiquark interaction through a factor k (that takes approximately the value 2) in a central phenomenological potential, reducing the four-body problem finally to a one body equivalent problem. The eigenproblem is solved using a combination of the DVR method and perturbation theory in a C++ code. We obtain a mass spectrum for the tetraquark between 6 GeV and 8 GeV for the ground and first energy excitation level. Our calculation indicates that our system is compact and that the non-relativistic approach used in all our formalism is valid.
hep-ph/0410077
Charles A. Nelson
Charles A. Nelson
Tests for the Statistics of Pair-Produced New Particles
For proceedings of "Vth Rencontres du Vietnam 2004", 5 pages, 1 figure
null
null
SUNY BING 9/26/04
hep-ph hep-ex hep-th
null
Due to selection rules, new particles are sometimes discovered/predicted to be produced in pairs. In the current search for SUSY particles this will occur if R-parity is conserved. In local relativistic field theory, there can be identical particles which are neither bosons nor fermions which are associated with higher-dimensional representations of the permutation group. Such particles will generally be pair-produced and so empirical tests are required to exclude them. A parameter-free statistical model is used to study the unusual multiplicity signatures in coherent paraboson production versus the case of ordinary bosons.
[ { "created": "Tue, 5 Oct 2004 18:36:16 GMT", "version": "v1" } ]
2016-09-06
[ [ "Nelson", "Charles A.", "" ] ]
Due to selection rules, new particles are sometimes discovered/predicted to be produced in pairs. In the current search for SUSY particles this will occur if R-parity is conserved. In local relativistic field theory, there can be identical particles which are neither bosons nor fermions which are associated with higher-dimensional representations of the permutation group. Such particles will generally be pair-produced and so empirical tests are required to exclude them. A parameter-free statistical model is used to study the unusual multiplicity signatures in coherent paraboson production versus the case of ordinary bosons.
1010.4172
C. A. Dominguez
C. A. Dominguez, M. Loewe, J. C. Rojas, Y. Zhang
(Pseudo)Scalar Charmonium in Finite Temperature QCD
12 pages, 5 figures. A wide range of critical temperatures has been considered. No qualitative changes to the conclusions
Phys.Rev.D83:034033,2011
10.1103/PhysRevD.83.034033
UCT-TP-283/10
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The hadronic parameters of pseudoscalar ($\eta_c$) and scalar ($\chi_c$) charmonium are determined at finite temperature from Hilbert moment QCD sum rules. These parameters are the hadron mass, leptonic decay constant, total width, and continuum threshold ($s_0$). Results for $s_0(T)$ in both channels indicate that $s_0(T)$ starts approximately constant, and then it decreases monotonically with increasing $T$ until it reaches the QCD threshold, $s_{th} = 4 m_Q^2$, at a critical temperature $T = T_c \simeq 180 \; \mbox{MeV}$ interpreted as the deconfinement temperature. The other hadronic parameters behave qualitatively similarly to those of the $J/\psi$, as determined in this same framework. The hadron mass is essentially constant, the total width is initially independent of T, and after $T/T_c \simeq 0.80$ it begins to increase with increasing $T$ up to $T/T_c \simeq 0.90 \; (0.95)$ for $\chi_c$ ($\eta_c$), and subsequently it decreases sharply up to $T \simeq 0.94 \; (0.99) \; T_c$, for $\chi_c$ ($\eta_c$), beyond which the sum rules are no longer valid. The decay constant of $\chi_c$ at first remains basically flat up to $T \simeq 0.80\; T_c$, then it starts to decrease up to $T \simeq 0.90 \;T_c$, and finally it increases sharply with increasing $T$. In the case of $\eta_c$ the decay constant does not change up to $T \simeq 0.80 \;T_c$ where it begins a gentle increase up to $T \simeq 0.95 \;T_c$ beyond which it increases dramatically with increasing $T$. This behaviour contrasts with that of light-light and heavy-light quark systems, and it suggests the survival of the $\eta_c$ and the $\chi_c$ states beyond the critical temperature, as already found for the $J/\psi$ from similar QCD sum rules. These conclusions are very stable against changes in the critical temperature in the wide range $T_c = 180 - 260 \; \mbox{MeV}$.
[ { "created": "Wed, 20 Oct 2010 12:10:07 GMT", "version": "v1" }, { "created": "Tue, 8 Feb 2011 14:55:53 GMT", "version": "v2" }, { "created": "Wed, 9 Feb 2011 14:08:38 GMT", "version": "v3" } ]
2011-03-23
[ [ "Dominguez", "C. A.", "" ], [ "Loewe", "M.", "" ], [ "Rojas", "J. C.", "" ], [ "Zhang", "Y.", "" ] ]
The hadronic parameters of pseudoscalar ($\eta_c$) and scalar ($\chi_c$) charmonium are determined at finite temperature from Hilbert moment QCD sum rules. These parameters are the hadron mass, leptonic decay constant, total width, and continuum threshold ($s_0$). Results for $s_0(T)$ in both channels indicate that $s_0(T)$ starts approximately constant, and then it decreases monotonically with increasing $T$ until it reaches the QCD threshold, $s_{th} = 4 m_Q^2$, at a critical temperature $T = T_c \simeq 180 \; \mbox{MeV}$ interpreted as the deconfinement temperature. The other hadronic parameters behave qualitatively similarly to those of the $J/\psi$, as determined in this same framework. The hadron mass is essentially constant, the total width is initially independent of T, and after $T/T_c \simeq 0.80$ it begins to increase with increasing $T$ up to $T/T_c \simeq 0.90 \; (0.95)$ for $\chi_c$ ($\eta_c$), and subsequently it decreases sharply up to $T \simeq 0.94 \; (0.99) \; T_c$, for $\chi_c$ ($\eta_c$), beyond which the sum rules are no longer valid. The decay constant of $\chi_c$ at first remains basically flat up to $T \simeq 0.80\; T_c$, then it starts to decrease up to $T \simeq 0.90 \;T_c$, and finally it increases sharply with increasing $T$. In the case of $\eta_c$ the decay constant does not change up to $T \simeq 0.80 \;T_c$ where it begins a gentle increase up to $T \simeq 0.95 \;T_c$ beyond which it increases dramatically with increasing $T$. This behaviour contrasts with that of light-light and heavy-light quark systems, and it suggests the survival of the $\eta_c$ and the $\chi_c$ states beyond the critical temperature, as already found for the $J/\psi$ from similar QCD sum rules. These conclusions are very stable against changes in the critical temperature in the wide range $T_c = 180 - 260 \; \mbox{MeV}$.
2403.07689
Alexandre Kisselev
H. Amarkhail, S.C. \.Inan, and A.V. Kisselev
Probing anomalous $Z\gamma\gamma\gamma$ couplings at a future muon collider
23 pages, 6 figures
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
The sensitivity to anomalous quartic gauge couplings (AQGCs) of the $\gamma\gamma\gamma Z$ interaction is studied in the $\mu^+\mu^- \rightarrow \mu^+\gamma\gamma \mu^-$ scattering at a future muon collider with unpolarized beams. The anomalous $\gamma\gamma\gamma Z$ vertex is described by two couplings, $\zeta_1$ and $\zeta_2$. The differential and total cross sections are calculated for the center-of-mass energies of 3 TeV, 14 TeV, and 100 TeV. For these values of the collision energy the $95\%$ C.L. exclusion regions for AQGCs are obtained depending on the systematic error. In particular, for the 14 TeV muon collider with the integrated luminosity $L = 20$ ab$^{-1}$ the best sensitivities are derived to be $\zeta_1 = 3.1 \times 10^{-5}$ TeV$^{-4}$ and $\zeta_2 = 6.5 \times 10^{-5}$ TeV$^{-4}$. These constraints are three orders of magnitude stronger than the bounds obtained for the 27 TeV HE-LHC with $L = 15$ ab$^{-1}$. At the 100 TeV muon collider with $L = 1000$ ab$^{-1}$ AQGCs can be probed up to $(1.64 \div 3.4) \times 10^{-8}$ TeV$^{-4}$. The partial-wave unitarity constraints on couplings $\zeta_1$, $\zeta_2$ are evaluated. It is shown that the unitarity is not violated in the region of the AQGCs examined in the present paper.
[ { "created": "Tue, 12 Mar 2024 14:31:38 GMT", "version": "v1" } ]
2024-03-13
[ [ "Amarkhail", "H.", "" ], [ "İnan", "S. C.", "" ], [ "Kisselev", "A. V.", "" ] ]
The sensitivity to anomalous quartic gauge couplings (AQGCs) of the $\gamma\gamma\gamma Z$ interaction is studied in the $\mu^+\mu^- \rightarrow \mu^+\gamma\gamma \mu^-$ scattering at a future muon collider with unpolarized beams. The anomalous $\gamma\gamma\gamma Z$ vertex is described by two couplings, $\zeta_1$ and $\zeta_2$. The differential and total cross sections are calculated for the center-of-mass energies of 3 TeV, 14 TeV, and 100 TeV. For these values of the collision energy the $95\%$ C.L. exclusion regions for AQGCs are obtained depending on the systematic error. In particular, for the 14 TeV muon collider with the integrated luminosity $L = 20$ ab$^{-1}$ the best sensitivities are derived to be $\zeta_1 = 3.1 \times 10^{-5}$ TeV$^{-4}$ and $\zeta_2 = 6.5 \times 10^{-5}$ TeV$^{-4}$. These constraints are three orders of magnitude stronger than the bounds obtained for the 27 TeV HE-LHC with $L = 15$ ab$^{-1}$. At the 100 TeV muon collider with $L = 1000$ ab$^{-1}$ AQGCs can be probed up to $(1.64 \div 3.4) \times 10^{-8}$ TeV$^{-4}$. The partial-wave unitarity constraints on couplings $\zeta_1$, $\zeta_2$ are evaluated. It is shown that the unitarity is not violated in the region of the AQGCs examined in the present paper.
hep-ph/0504002
Mikhail Braun
M.A.Braun
Conformal invariant equations for nucleus-nucleus scattering in perturbative QCD with $N_c\to\infty$
10 pages in LaTex, including 2 figures
null
null
null
hep-ph
null
In the perturbative QCD with $N_c\to\infty$ the amplitude for the collision of two heavy nuclei is expressed via dipole densities in the nuclei. Coupled equations for these densities are derived in the configuration space. The equations are conformal invariant in absence of external sources. Passing to conformal basis and its possible truncation are discussed.
[ { "created": "Fri, 1 Apr 2005 04:57:49 GMT", "version": "v1" }, { "created": "Sun, 3 Apr 2005 15:23:01 GMT", "version": "v2" } ]
2007-05-23
[ [ "Braun", "M. A.", "" ] ]
In the perturbative QCD with $N_c\to\infty$ the amplitude for the collision of two heavy nuclei is expressed via dipole densities in the nuclei. Coupled equations for these densities are derived in the configuration space. The equations are conformal invariant in absence of external sources. Passing to conformal basis and its possible truncation are discussed.
2311.03181
Mykyta Dmytriiev
Mykyta Dmytriiev, Volodymyr Skalozub
One-loop correction contributions in the decoupling limit of generalized Yukawa model
null
Journal of Physics and Electronics, 31(2), p. 3, 2023
10.15421/332314
null
hep-ph
http://creativecommons.org/licenses/by-sa/4.0/
We consider the generalized Yukawa model consisting of two Dirac fermions and two scalar fields. One of the scalars is assumed to be much heavier than the other particles, so it decouples at low energies. Low-energy effective Lagrangian (EL) of the model is derived. It describes the contributions of the heavy scalar into observables in the limit when this particle is decoupled. We consider the cross-sections of $s$- and $t$-channel processes, obtained within the complete model and its low-energy approximation. The contributions of the one-loop corrections in the cross-sections coming from light particles are analyzed. These are corrections to the parameters of the heavy boson and the contributions of the one-loop mixing of light and heavy scalars. We identify the ranges of Yukawa's couplings where the corrections are significant. We find that if the interaction between fermions and either light or heavy scalar is strong enough, the derived EL could not be applied for the description of the analyzed cross-sections even if the heavy scalar decouples. Implications of our results in searching for new particles beyond the Standard model are discussed.
[ { "created": "Mon, 6 Nov 2023 15:21:47 GMT", "version": "v1" }, { "created": "Sat, 25 May 2024 10:59:04 GMT", "version": "v2" } ]
2024-05-28
[ [ "Dmytriiev", "Mykyta", "" ], [ "Skalozub", "Volodymyr", "" ] ]
We consider the generalized Yukawa model consisting of two Dirac fermions and two scalar fields. One of the scalars is assumed to be much heavier than the other particles, so it decouples at low energies. Low-energy effective Lagrangian (EL) of the model is derived. It describes the contributions of the heavy scalar into observables in the limit when this particle is decoupled. We consider the cross-sections of $s$- and $t$-channel processes, obtained within the complete model and its low-energy approximation. The contributions of the one-loop corrections in the cross-sections coming from light particles are analyzed. These are corrections to the parameters of the heavy boson and the contributions of the one-loop mixing of light and heavy scalars. We identify the ranges of Yukawa's couplings where the corrections are significant. We find that if the interaction between fermions and either light or heavy scalar is strong enough, the derived EL could not be applied for the description of the analyzed cross-sections even if the heavy scalar decouples. Implications of our results in searching for new particles beyond the Standard model are discussed.
2105.12142
Benjamin Sheff
Raymond T. Co, Benjamin Sheff, James D. Wells
The Race to Find Split Higgsino Dark Matter
10 pages, 7 figures
null
10.1103/PhysRevD.105.035012
LCTP-21-11, UMN-TH-4016/21, FTPI-MINN-21/09
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Split higgsinos are a compelling class of models to explain dark matter and may be on the verge of detection by multiple current experimental avenues. The idea is based on a large split in scales between the electroweak scale and decoupled scalars, with relatively light higgsinos between the two. Such models enjoy the merit of depending on very few parameters while still explaining gauge coupling unification, dark matter, and most of the hierarchy between the Planck and electroweak scales, and they remain undetected by past experiments. We analyze split higgsinos in view of current and next generation experiments. We discuss the direct and indirect detection prospects and further demonstrate promising discovery potentials in the upcoming electron electric dipole moment experiments. The parameter space of this model is analyzed in terms of experiments expected to run in the coming years and where we should be looking for the next potential discoveries.
[ { "created": "Tue, 25 May 2021 18:00:03 GMT", "version": "v1" } ]
2022-02-23
[ [ "Co", "Raymond T.", "" ], [ "Sheff", "Benjamin", "" ], [ "Wells", "James D.", "" ] ]
Split higgsinos are a compelling class of models to explain dark matter and may be on the verge of detection by multiple current experimental avenues. The idea is based on a large split in scales between the electroweak scale and decoupled scalars, with relatively light higgsinos between the two. Such models enjoy the merit of depending on very few parameters while still explaining gauge coupling unification, dark matter, and most of the hierarchy between the Planck and electroweak scales, and they remain undetected by past experiments. We analyze split higgsinos in view of current and next generation experiments. We discuss the direct and indirect detection prospects and further demonstrate promising discovery potentials in the upcoming electron electric dipole moment experiments. The parameter space of this model is analyzed in terms of experiments expected to run in the coming years and where we should be looking for the next potential discoveries.
hep-ph/0103127
Jeonghyeon Song
C. S. Kim, J. D. Kim (Yonsei Univ.) and Jeonghyeon Song (KIAS)
Muon Anomalous Magnetic Moment (g-2)_mu and the Randall-Sundrum Model
Final version to appear in PLB
Phys.Lett. B511 (2001) 251-256
10.1016/S0370-2693(01)00635-9
YUMS-01-01, KIAS P01014
hep-ph
null
We study the effects of the Kaluza-Klein gravitons in the Randall-Sundrum model on the recent BNL measurements of the muon (g-2) deviation from the standard model prediction. By examining the J-partial wave unitarity bounds of the elastic process gamma+gamma->gamma+gamma, the cut-off on the number of massive KK gravitons, n_c, has been introduced. We found that the recently measured (Delta a_mu) can be accommodated in the RS model, within the natural parameter space allowed by the perturbative unitarity. For example, dozens (hundreds) of the n_c for Lambda_pi=1-2 TeV (3 TeV) can explain the reported Delta a_mu.
[ { "created": "Tue, 13 Mar 2001 03:42:51 GMT", "version": "v1" }, { "created": "Fri, 30 Mar 2001 08:03:10 GMT", "version": "v2" }, { "created": "Fri, 18 May 2001 05:18:14 GMT", "version": "v3" } ]
2009-11-07
[ [ "Kim", "C. S.", "", "Yonsei Univ." ], [ "Kim", "J. D.", "", "Yonsei Univ." ], [ "Song", "Jeonghyeon", "", "KIAS" ] ]
We study the effects of the Kaluza-Klein gravitons in the Randall-Sundrum model on the recent BNL measurements of the muon (g-2) deviation from the standard model prediction. By examining the J-partial wave unitarity bounds of the elastic process gamma+gamma->gamma+gamma, the cut-off on the number of massive KK gravitons, n_c, has been introduced. We found that the recently measured (Delta a_mu) can be accommodated in the RS model, within the natural parameter space allowed by the perturbative unitarity. For example, dozens (hundreds) of the n_c for Lambda_pi=1-2 TeV (3 TeV) can explain the reported Delta a_mu.
0706.1845
Yosef Nir
Yuval Grossman, Yosef Nir, Jesse Thaler, Tomer Volansky and Jure Zupan
Probing Minimal Flavor Violation at the LHC
18 pages, 1 figure, appendix added, journal version
Phys.Rev.D76:096006,2007
10.1103/PhysRevD.76.096006
null
hep-ph hep-ex
null
If the LHC experiments discover new particles that couple to the Standard Model fermions, then measurements by ATLAS and CMS can contribute to our understanding of the flavor puzzles. We demonstrate this statement by investigating a scenario where extra SU(2)-singlet down-type quarks are within the LHC reach. By measuring masses, production cross sections and relative decay rates, minimal flavor violation (MFV) can in principle be excluded. Conversely, these measurements can probe the way in which MFV applies to the new degrees of freedom. Many of our conclusions are valid in a much more general context than this specific extension of the Standard Model.
[ { "created": "Wed, 13 Jun 2007 08:25:01 GMT", "version": "v1" }, { "created": "Wed, 21 Nov 2007 19:45:23 GMT", "version": "v2" } ]
2008-11-26
[ [ "Grossman", "Yuval", "" ], [ "Nir", "Yosef", "" ], [ "Thaler", "Jesse", "" ], [ "Volansky", "Tomer", "" ], [ "Zupan", "Jure", "" ] ]
If the LHC experiments discover new particles that couple to the Standard Model fermions, then measurements by ATLAS and CMS can contribute to our understanding of the flavor puzzles. We demonstrate this statement by investigating a scenario where extra SU(2)-singlet down-type quarks are within the LHC reach. By measuring masses, production cross sections and relative decay rates, minimal flavor violation (MFV) can in principle be excluded. Conversely, these measurements can probe the way in which MFV applies to the new degrees of freedom. Many of our conclusions are valid in a much more general context than this specific extension of the Standard Model.
1909.04067
Felix Giese
Felix Giese and Thomas Konstandin
Vacuum stability of Froggatt-Nielsen models
26 pages, 8 figures
null
10.1007/JHEP12(2019)091
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss vacuum stability in Froggatt-Nielsen (FN) models. One concern in FN models is that for large flavon VEVs the running of the quartic Higgs coupling is enhanced what might lead to a more severe instability compared to the Standard Model (SM). We study this issue using the renormalization-group improved scalar potential. Another issue is that the mixing between the Higgs and the flavon can potentially destabilize the potential. However, taking current bounds on the flavon phenomenology into account, we find that both effects do not lead to an instability that is more severe than in the SM.
[ { "created": "Mon, 9 Sep 2019 18:01:36 GMT", "version": "v1" } ]
2020-01-29
[ [ "Giese", "Felix", "" ], [ "Konstandin", "Thomas", "" ] ]
We discuss vacuum stability in Froggatt-Nielsen (FN) models. One concern in FN models is that for large flavon VEVs the running of the quartic Higgs coupling is enhanced what might lead to a more severe instability compared to the Standard Model (SM). We study this issue using the renormalization-group improved scalar potential. Another issue is that the mixing between the Higgs and the flavon can potentially destabilize the potential. However, taking current bounds on the flavon phenomenology into account, we find that both effects do not lead to an instability that is more severe than in the SM.
hep-ph/0602065
Igor Shovkovy
Masakiyo Kitazawa, Dirk H. Rischke, Igor A. Shovkovy
Stable gapless superconductivity at strong coupling
8 pages, 4 figures
Phys.Lett. B637 (2006) 367-373
10.1016/j.physletb.2006.04.054
null
hep-ph cond-mat.supr-con nucl-th
null
We study cross-flavor Cooper pairing in a relativistic system of two fermion species with mismatched Fermi surfaces. We find that there exist gapless phases which are characterized by either one or two gapless nodes in the energy spectra of their quasiparticles. An analysis of the current-current correlator reveals that, at strong coupling, both of these gapless phases can be free of magnetic instabilities and thus are stable. This is in contrast to the weak-coupling case where there are always two gapless nodes and the phase becomes magnetically unstable.
[ { "created": "Tue, 7 Feb 2006 16:26:03 GMT", "version": "v1" } ]
2009-11-11
[ [ "Kitazawa", "Masakiyo", "" ], [ "Rischke", "Dirk H.", "" ], [ "Shovkovy", "Igor A.", "" ] ]
We study cross-flavor Cooper pairing in a relativistic system of two fermion species with mismatched Fermi surfaces. We find that there exist gapless phases which are characterized by either one or two gapless nodes in the energy spectra of their quasiparticles. An analysis of the current-current correlator reveals that, at strong coupling, both of these gapless phases can be free of magnetic instabilities and thus are stable. This is in contrast to the weak-coupling case where there are always two gapless nodes and the phase becomes magnetically unstable.
2212.07904
Satoshi Nakamura
S. X. Nakamura (Univ. of Science and Technology of China), Q. Huang (Nanjing Normal Univ.), J. -J. Wu (Univ. of Chinese Academy of Sciences), H. P. Peng (Univ. of Science and Technology of China), Y. Zhang (Univ. of Science and Technology of China), Y. C. Zhu (Univ. of Science and Technology of China)
Three-Body Unitary Coupled-Channel Analysis on $\eta(1405/1475)$
7 pages, 6 figures; (v2) published version; statistical errors for eta(1405/1475) pole positions are added
Phys. Rev. D 107, L091505 (2023)
10.1103/PhysRevD.107.L091505
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recent BESIII data on $J/\psi\to\gamma(K_SK_S\pi^0)$, which is significantly more precise than earlier $\eta(1405/1475)$-related data, enables quantitative discussions on $\eta(1405/1475)$ at the previously unreachable level. We conduct a three-body unitary coupled-channel analysis of experimental Monte-Carlo outputs for radiative $J/\psi$ decays via $\eta(1405/1475)$: $K_SK_S\pi^0$ Dalitz plot distributions from the BESIII, and branching ratios of $\gamma(\eta\pi^+\pi^-)$ and $\gamma(\gamma\pi^+\pi^-)$ final states relative to that of $\gamma(K\bar{K}\pi)$. Our model systematically considers (multi-)loop diagrams and an associated triangle singularity, which is critical in making excellent predictions on $\eta(1405/1475)\to \pi\pi\pi$ lineshapes and branching ratios. The $\eta(1405/1475)$ pole locations are revealed for the first time. Two poles for $\eta(1405)$ are found on different Riemann sheets of the $K^*\bar{K}$ channel, while one pole for $\eta(1475)$. The $\eta(1405/1475)$ states are described with two bare states dressed by continuum states. The lower bare state would be an excited $\eta^\prime$, while the higher one could be an excited $\eta^{(\prime)}$, hybrid, glueball, or their mixture. This work presents the first-ever pole determination based on a manifestly three-body unitary coupled-channel framework applied to experimental three-body final state distributions (Dalitz plots).
[ { "created": "Thu, 15 Dec 2022 15:37:18 GMT", "version": "v1" }, { "created": "Thu, 25 May 2023 14:59:07 GMT", "version": "v2" } ]
2023-05-26
[ [ "Nakamura", "S. X.", "", "Univ. of Science and Technology of China" ], [ "Huang", "Q.", "", "Nanjing Normal Univ." ], [ "Wu", "J. -J.", "", "Univ. of Chinese Academy of Sciences" ], [ "Peng", "H. P.", "", "Univ. of Science and Technology of China" ], [ "Zhang", "Y.", "", "Univ. of\n Science and Technology of China" ], [ "Zhu", "Y. C.", "", "Univ. of Science and Technology\n of China" ] ]
The recent BESIII data on $J/\psi\to\gamma(K_SK_S\pi^0)$, which is significantly more precise than earlier $\eta(1405/1475)$-related data, enables quantitative discussions on $\eta(1405/1475)$ at the previously unreachable level. We conduct a three-body unitary coupled-channel analysis of experimental Monte-Carlo outputs for radiative $J/\psi$ decays via $\eta(1405/1475)$: $K_SK_S\pi^0$ Dalitz plot distributions from the BESIII, and branching ratios of $\gamma(\eta\pi^+\pi^-)$ and $\gamma(\gamma\pi^+\pi^-)$ final states relative to that of $\gamma(K\bar{K}\pi)$. Our model systematically considers (multi-)loop diagrams and an associated triangle singularity, which is critical in making excellent predictions on $\eta(1405/1475)\to \pi\pi\pi$ lineshapes and branching ratios. The $\eta(1405/1475)$ pole locations are revealed for the first time. Two poles for $\eta(1405)$ are found on different Riemann sheets of the $K^*\bar{K}$ channel, while one pole for $\eta(1475)$. The $\eta(1405/1475)$ states are described with two bare states dressed by continuum states. The lower bare state would be an excited $\eta^\prime$, while the higher one could be an excited $\eta^{(\prime)}$, hybrid, glueball, or their mixture. This work presents the first-ever pole determination based on a manifestly three-body unitary coupled-channel framework applied to experimental three-body final state distributions (Dalitz plots).
0907.0563
Valery Lyubovitskij
Amand Faessler, Thomas Gutsche, Mikhail A. Ivanov, Jurgen G. Korner, Valery E. Lyubovitskij
Semileptonic decays of double heavy baryons in a relativistic constituent three-quark model
20 pages, 2 figures
Phys.Rev.D80:034025,2009
10.1103/PhysRevD.80.034025
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the semileptonic decays of double heavy baryons using a manifestly Lorentz covariant constituent three-quark model. We present complete results on transition form factors between double-heavy baryons for finite values of the heavy quark/baryon masses and in the heavy quark symmetry limit which is valid at and close to zero recoil. Decay rates are calculated and compared to each other in the full theory, keeping masses finite, and also in the heavy quark limit.
[ { "created": "Fri, 3 Jul 2009 08:52:06 GMT", "version": "v1" } ]
2009-12-07
[ [ "Faessler", "Amand", "" ], [ "Gutsche", "Thomas", "" ], [ "Ivanov", "Mikhail A.", "" ], [ "Korner", "Jurgen G.", "" ], [ "Lyubovitskij", "Valery E.", "" ] ]
We study the semileptonic decays of double heavy baryons using a manifestly Lorentz covariant constituent three-quark model. We present complete results on transition form factors between double-heavy baryons for finite values of the heavy quark/baryon masses and in the heavy quark symmetry limit which is valid at and close to zero recoil. Decay rates are calculated and compared to each other in the full theory, keeping masses finite, and also in the heavy quark limit.
hep-ph/0408315
Willy Van Neerven wvn
V. Ravindran, J. Smith, W.L. van Neerven
Two-loop corrections to Higgs boson production
27 pages LaTeX.We correct some misprints. Moreover we have discovered that the second order single pole term is equal to the singular part of the second order anomalous dimension plus a universal function which is the same for the quark and the gluon. This holds for vertex corrections as well as for scattering amplitudes
Nucl.Phys. B704 (2005) 332-348
10.1016/j.nuclphysb.2004.10.039
YITP-SB-04-46
hep-ph
null
In this paper we present the complete two-loop vertex corrections to scalar and pseudo-scalar Higgs boson production for general colour factors for the gauge group ${\rm SU(N)}$ in the limit where the top quark mass gets infinite. We derive a general formula for the vertex correction which holds for conserved and non conserved operators. For the conserved operator we take the electromagnetic vertex correction as an example whereas for the non conserved operators we take the two vertex corrections above. Our observations for the structure of the pole terms $1/\epsilon^4$, $1/\epsilon^3$ and $1/\epsilon^2$ in two loop order are the same as made earlier in the literature for electromagnetism. However we also elucidate the origin of the second order single pole term which is equal to the second order singular part of the anomalous dimension plus a universal function which is the same for the quark and the gluon. [3mm]
[ { "created": "Fri, 27 Aug 2004 12:41:56 GMT", "version": "v1" }, { "created": "Mon, 11 Oct 2004 16:16:13 GMT", "version": "v2" } ]
2010-04-05
[ [ "Ravindran", "V.", "" ], [ "Smith", "J.", "" ], [ "van Neerven", "W. L.", "" ] ]
In this paper we present the complete two-loop vertex corrections to scalar and pseudo-scalar Higgs boson production for general colour factors for the gauge group ${\rm SU(N)}$ in the limit where the top quark mass gets infinite. We derive a general formula for the vertex correction which holds for conserved and non conserved operators. For the conserved operator we take the electromagnetic vertex correction as an example whereas for the non conserved operators we take the two vertex corrections above. Our observations for the structure of the pole terms $1/\epsilon^4$, $1/\epsilon^3$ and $1/\epsilon^2$ in two loop order are the same as made earlier in the literature for electromagnetism. However we also elucidate the origin of the second order single pole term which is equal to the second order singular part of the anomalous dimension plus a universal function which is the same for the quark and the gluon. [3mm]
hep-ph/0209279
Zhang Ren-You
Yin Jun, Ma Wen-Gan, Zhang Ren-You, and Hou Hong-Sheng
$A^{0}Z^{0}$ associated production at the Large Hadron Collider in the minimal supersymmetric standard model
18 pages, 9 figures, accepted by Phys. Rev. D
null
null
null
hep-ph
null
We investigate in detail the $A^{0}Z^{0}$ associated production process $pp \to A^0Z^0+X$ within the framework of the minimal supersymmetric standard model (MSSM) at the CERN Large Hadron Collider (LHC), considering both contributions from the Drell-Yan and gluon fusion subprocesses. We focus on the deviations from the general two-Higgs-doublet model (2HDM) arising in the MSSM. We also discuss the contributions of the two $A^{0}Z^{0}$ associated production subprocesses in the MSSM at the LHC, and analyse the dependences of the total cross section on neutral CP-odd Higgs boson mass $m_A$ and $\tan\beta$ in the mSUGRA scenario. We find that the contribution from loop mediated gluon fusion subprocess can be competitive with that from the Drell-Yan subprocess in some parameter space.
[ { "created": "Tue, 24 Sep 2002 11:55:54 GMT", "version": "v1" }, { "created": "Sun, 29 Sep 2002 01:32:31 GMT", "version": "v2" } ]
2007-05-23
[ [ "Jun", "Yin", "" ], [ "Wen-Gan", "Ma", "" ], [ "Ren-You", "Zhang", "" ], [ "Hong-Sheng", "Hou", "" ] ]
We investigate in detail the $A^{0}Z^{0}$ associated production process $pp \to A^0Z^0+X$ within the framework of the minimal supersymmetric standard model (MSSM) at the CERN Large Hadron Collider (LHC), considering both contributions from the Drell-Yan and gluon fusion subprocesses. We focus on the deviations from the general two-Higgs-doublet model (2HDM) arising in the MSSM. We also discuss the contributions of the two $A^{0}Z^{0}$ associated production subprocesses in the MSSM at the LHC, and analyse the dependences of the total cross section on neutral CP-odd Higgs boson mass $m_A$ and $\tan\beta$ in the mSUGRA scenario. We find that the contribution from loop mediated gluon fusion subprocess can be competitive with that from the Drell-Yan subprocess in some parameter space.
hep-ph/9409404
null
Alan Chodos and Alan Kostelecky, IUHET 280
Nuclear Null Tests for Spacelike Neutrinos
June 1994, accepted for publication in Physics Letters B
Phys.Lett.B336:295-302,1994
10.1016/0370-2693(94)90535-5
null
hep-ph nucl-th
null
Recently, a type of null experiment for spacelike neutrinos has been proposed. We examine in detail a class of null tests involving nuclear beta decay or capture in atoms and ions. The most promising candidate systems are identified.
[ { "created": "Sat, 24 Sep 1994 16:56:51 GMT", "version": "v1" } ]
2009-09-25
[ [ "Chodos", "Alan", "" ], [ "Kostelecky", "Alan", "" ], [ "280", "IUHET", "" ] ]
Recently, a type of null experiment for spacelike neutrinos has been proposed. We examine in detail a class of null tests involving nuclear beta decay or capture in atoms and ions. The most promising candidate systems are identified.
1112.6052
Hong-Hao Zhang
Zhao-Huan Yu, Jia-Ming Zheng, Xiao-Jun Bi, Zhibing Li, Dao-Xin Yao, Hong-Hao Zhang
Constraining the interaction strength between dark matter and visible matter: II. scalar, vector and spin-3/2 dark matter
31 pages, 28 figures, 3 tables, references added, minor changes
Nucl.Phys.B860:115-151,2012
10.1016/j.nuclphysb.2012.02.016
null
hep-ph astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the constraints on the scalar, vector and spin-3/2 dark matter interaction with the standard model particles, from the observations of dark matter relic density, the direct detection experiments of CDMS and XENON, and the indirect detection of the antiproton-to-proton ratio by PAMELA. A model independent way is adopted by constructing general 4-particle operators up to dimension 6 for the effective interaction between dark matter and standard model particles. We find that the constraints from different experiments are complementary with each other. Comparison among these constraints may exclude some effective models of dark matter and limit some parameters of others. The spin-independent direct detection gives strong constraints for some operators, while the indirect detection of antiproton-to-proton data can be more sensitive than direct detection or relic density for light dark matter (whose mass less than 70 GeV) in some cases. The constraints on some operators for spin-3/2 dark matter are shown to be similar to those on their analogous operators for Dirac fermionic dark matter. There are still some operators not sensitive to the current dark matter direct and indirect search experiments.
[ { "created": "Wed, 28 Dec 2011 03:21:41 GMT", "version": "v1" }, { "created": "Sat, 7 Jan 2012 12:07:25 GMT", "version": "v2" } ]
2012-03-14
[ [ "Yu", "Zhao-Huan", "" ], [ "Zheng", "Jia-Ming", "" ], [ "Bi", "Xiao-Jun", "" ], [ "Li", "Zhibing", "" ], [ "Yao", "Dao-Xin", "" ], [ "Zhang", "Hong-Hao", "" ] ]
We investigate the constraints on the scalar, vector and spin-3/2 dark matter interaction with the standard model particles, from the observations of dark matter relic density, the direct detection experiments of CDMS and XENON, and the indirect detection of the antiproton-to-proton ratio by PAMELA. A model independent way is adopted by constructing general 4-particle operators up to dimension 6 for the effective interaction between dark matter and standard model particles. We find that the constraints from different experiments are complementary with each other. Comparison among these constraints may exclude some effective models of dark matter and limit some parameters of others. The spin-independent direct detection gives strong constraints for some operators, while the indirect detection of antiproton-to-proton data can be more sensitive than direct detection or relic density for light dark matter (whose mass less than 70 GeV) in some cases. The constraints on some operators for spin-3/2 dark matter are shown to be similar to those on their analogous operators for Dirac fermionic dark matter. There are still some operators not sensitive to the current dark matter direct and indirect search experiments.
1704.05068
Claudia Frugiuele
Julian C. Berengut, Dmitry Budker, Cedric Delaunay, Victor V. Flambaum, Claudia Frugiuele, Elina Fuchs, Christophe Grojean, Roni Harnik, Roee Ozeri, Gilad Perez, and Yotam Soreq
Probing new light force-mediators by isotope shift spectroscopy
6 pages, 1 figure
Phys. Rev. Lett. 120, 091801 (2018)
10.1103/PhysRevLett.120.091801
null
hep-ph physics.atm-clus quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this Letter we explore the potential of probing new light force-carriers, with spin-independent couplings to the electron and the neutron, using precision isotope shift spectroscopy. We develop a formalism to interpret linear King plots as bounds on new physics with minimal theory inputs. We focus only on bounding the new physics contributions that can be calculated independently of the Standard Model nuclear effects. We apply our method to existing Ca+ data and project its sensitivity to possibly existing new bosons using narrow transitions in other atoms and ions (specifically, Sr and Yb). Future measurements are expected to improve the relative precision by five orders of magnitude, and can potentially lead to an unprecedented sensitivity for bosons within the 10 keV to 10 MeV mass range.
[ { "created": "Mon, 17 Apr 2017 18:00:01 GMT", "version": "v1" } ]
2018-03-07
[ [ "Berengut", "Julian C.", "" ], [ "Budker", "Dmitry", "" ], [ "Delaunay", "Cedric", "" ], [ "Flambaum", "Victor V.", "" ], [ "Frugiuele", "Claudia", "" ], [ "Fuchs", "Elina", "" ], [ "Grojean", "Christophe", "" ], [ "Harnik", "Roni", "" ], [ "Ozeri", "Roee", "" ], [ "Perez", "Gilad", "" ], [ "Soreq", "Yotam", "" ] ]
In this Letter we explore the potential of probing new light force-carriers, with spin-independent couplings to the electron and the neutron, using precision isotope shift spectroscopy. We develop a formalism to interpret linear King plots as bounds on new physics with minimal theory inputs. We focus only on bounding the new physics contributions that can be calculated independently of the Standard Model nuclear effects. We apply our method to existing Ca+ data and project its sensitivity to possibly existing new bosons using narrow transitions in other atoms and ions (specifically, Sr and Yb). Future measurements are expected to improve the relative precision by five orders of magnitude, and can potentially lead to an unprecedented sensitivity for bosons within the 10 keV to 10 MeV mass range.
1908.07312
Cristian Pisano
Cristian Pisano, Umberto D'Alesio, Carlo Flore, Francesco Murgia, Pieter Taels
The gluon Sivers function and its process dependence from RHIC data
6 pages, 3 figures, to appear in the Proceedings of the 27th International Workshop on Deep Inelastic Scattering and Related Subjects (DIS 2019), Torino (Italy), 8-12 April 2019
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a phenomenological analysis of available data on single spin asymmetries for pion and $D$ meson production in proton-proton collisions at RHIC within the color gauge invariant generalized parton model (CGI-GPM), which includes initial (ISIs) and final (FSIs) state interactions in a transverse momentum dependent formalism. This study allows us, for the first time, to put preliminary constraints on the two independent gluon Sivers functions entering the model. We also present a comparison with the simpler generalized parton model (without ISIs and FSIs).
[ { "created": "Tue, 20 Aug 2019 12:54:21 GMT", "version": "v1" } ]
2019-08-21
[ [ "Pisano", "Cristian", "" ], [ "D'Alesio", "Umberto", "" ], [ "Flore", "Carlo", "" ], [ "Murgia", "Francesco", "" ], [ "Taels", "Pieter", "" ] ]
We present a phenomenological analysis of available data on single spin asymmetries for pion and $D$ meson production in proton-proton collisions at RHIC within the color gauge invariant generalized parton model (CGI-GPM), which includes initial (ISIs) and final (FSIs) state interactions in a transverse momentum dependent formalism. This study allows us, for the first time, to put preliminary constraints on the two independent gluon Sivers functions entering the model. We also present a comparison with the simpler generalized parton model (without ISIs and FSIs).
hep-ph/0203097
M. K. Parida
M. K. Parida, C. R. Das (North-Eastern Hill Univ.), G. Rajasekaran (Institute of Mathematical Sciences, India)
Radiative stability of neutrino-mass textures
4 pages REVTEX, 1 Postscript fig
Pramana62:647-650,2004
10.1007/BF02705337
NEHU/PHY-MP-01/2002
hep-ph
null
Neutrino-mass textures proposed at high-scales are known to be unstable against radiative corrections especially for nearly degenerate eigen values. Within the renormalization group constraints we find a mechanism in a class of gauge theories which guarantees reproduction of any high-scale texture at low energies with radiative stability. We also show how the mechanism explains solar and atmospheric neutrino anomalies through the bimaximal texture at high scale.
[ { "created": "Sun, 10 Mar 2002 07:53:01 GMT", "version": "v1" } ]
2008-11-26
[ [ "Parida", "M. K.", "", "North-Eastern Hill Univ." ], [ "Das", "C. R.", "", "North-Eastern Hill Univ." ], [ "Rajasekaran", "G.", "", "Institute of Mathematical Sciences, India" ] ]
Neutrino-mass textures proposed at high-scales are known to be unstable against radiative corrections especially for nearly degenerate eigen values. Within the renormalization group constraints we find a mechanism in a class of gauge theories which guarantees reproduction of any high-scale texture at low energies with radiative stability. We also show how the mechanism explains solar and atmospheric neutrino anomalies through the bimaximal texture at high scale.
hep-ph/9507379
null
Paolo Ciafaloni, Andrea Romanino and Alessandro Strumia
Lepton Flavour Violations in SO(10) with large $\tan\beta$
Final published version with one new figure added
Nucl.Phys.B458:3-22,1996
10.1016/0550-3213(95)00552-8
null
hep-ph
null
In supersymmetric~SO(10) with large $\tan\beta$ and Yukawa coupling unification $\lambda_t=\lambda_b=\lambda_\tau$, we compute the rates for lepton flavour violating processes. Experiments in progress or foreseen for $\mu\to e\gamma$, $\mu\to e$ conversion (and the dipole moment of the electron) are shown to provide very significant tests of the theory for all slepton masses up to about $1\TeV$.
[ { "created": "Fri, 21 Jul 1995 18:15:00 GMT", "version": "v1" }, { "created": "Thu, 19 Oct 1995 18:17:08 GMT", "version": "v2" }, { "created": "Wed, 25 Oct 1995 17:18:00 GMT", "version": "v3" } ]
2009-10-09
[ [ "Ciafaloni", "Paolo", "" ], [ "Romanino", "Andrea", "" ], [ "Strumia", "Alessandro", "" ] ]
In supersymmetric~SO(10) with large $\tan\beta$ and Yukawa coupling unification $\lambda_t=\lambda_b=\lambda_\tau$, we compute the rates for lepton flavour violating processes. Experiments in progress or foreseen for $\mu\to e\gamma$, $\mu\to e$ conversion (and the dipole moment of the electron) are shown to provide very significant tests of the theory for all slepton masses up to about $1\TeV$.
2011.09101
Sandra Robles
M. E. Cabrera, J. A. Casas, A. Delgado, S. Robles
2HDM singlet portal to dark matter
15 pages, 8 figures, 2 tables
JHEP 01 (2021) 123
10.1007/JHEP01(2021)123
IFT-UAM/CSIC-20-161
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Higgs portal models are the most minimal way to explain the relic abundance of the Universe. They add just a singlet that only couples to the Higgs through a single parameter that controls both the dark matter relic abundance and the direct detection cross-section. Unfortunately this scenario, either with scalar or fermionic dark matter, is almost ruled out by the latter. In this paper we analyze the Higgs-portal idea with fermionic dark matter in the context of a 2HDM. By disentangling the couplings responsible for the correct relic density from those that control the direct detection cross section we are able to open the parameter space and find wide regions consistent with both the observed relic density and all the current bounds.
[ { "created": "Wed, 18 Nov 2020 05:44:45 GMT", "version": "v1" }, { "created": "Fri, 22 Jan 2021 05:59:30 GMT", "version": "v2" } ]
2021-01-25
[ [ "Cabrera", "M. E.", "" ], [ "Casas", "J. A.", "" ], [ "Delgado", "A.", "" ], [ "Robles", "S.", "" ] ]
Higgs portal models are the most minimal way to explain the relic abundance of the Universe. They add just a singlet that only couples to the Higgs through a single parameter that controls both the dark matter relic abundance and the direct detection cross-section. Unfortunately this scenario, either with scalar or fermionic dark matter, is almost ruled out by the latter. In this paper we analyze the Higgs-portal idea with fermionic dark matter in the context of a 2HDM. By disentangling the couplings responsible for the correct relic density from those that control the direct detection cross section we are able to open the parameter space and find wide regions consistent with both the observed relic density and all the current bounds.
1412.8308
Pedro Fernando Simoes Costa
Constan\c{c}a Provid\^encia, M\'arcio Ferreira, Pedro Costa
Inverse magnetic catalysis in the Polyakov-Nambu-Jona-Lasinio and entangled Polyakov-Nambu-Jona-Lasinio models
Contribution to the workshop "EEF70 - Workshop on Unquenched Hadron Spectroscopy: Non-Perturbative Models and Methods of QCD vs. Experiment", Coimbra, Portugal, September 1-5, 2014
Acta Phys.Polon.Supp. 8 (2015) 1, 207
10.5506/APhysPolBSupp.8.207
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the QCD phase diagram at zero chemical potential and finite temperature in the presence of an external magnetic field within the three flavor Polyakov-Nambu-Jona-Lasinio and entangled Polyakov-Nambu-Jona-Lasinio models looking for the inverse magnetic catalysis. Two scenarios for a scalar coupling parameter dependent on the magnetic field intensity are considered. These dependencies of the coupling allow to reproduce qualitatively lattice QCD results for the quark condensates and for the Polyakov loop: due to the magnetic field the quark condensates are enhanced at low and high temperatures and suppressed for temperatures close to the transition temperatures while the Polyakov loop increases with the increasing of the magnetic field.
[ { "created": "Mon, 29 Dec 2014 11:15:12 GMT", "version": "v1" } ]
2015-08-10
[ [ "Providência", "Constança", "" ], [ "Ferreira", "Márcio", "" ], [ "Costa", "Pedro", "" ] ]
We investigate the QCD phase diagram at zero chemical potential and finite temperature in the presence of an external magnetic field within the three flavor Polyakov-Nambu-Jona-Lasinio and entangled Polyakov-Nambu-Jona-Lasinio models looking for the inverse magnetic catalysis. Two scenarios for a scalar coupling parameter dependent on the magnetic field intensity are considered. These dependencies of the coupling allow to reproduce qualitatively lattice QCD results for the quark condensates and for the Polyakov loop: due to the magnetic field the quark condensates are enhanced at low and high temperatures and suppressed for temperatures close to the transition temperatures while the Polyakov loop increases with the increasing of the magnetic field.
hep-ph/0609213
Leszek Motyka
S. Bondarenko, L. Motyka, A.H. Mueller, A.I. Shoshi and B.-W. Xiao
On the equivalence of Reggeon field theory in zero transverse dimensions and reaction-diffusion processes
19 pages, no figures
Eur.Phys.J.C50:593-601,2007
10.1140/epjc/s10052-007-0218-6
BI-TP 2006/36, CU-TP-1161, DESY 06-167
hep-ph
null
The Reggeon field theory in zero transverse dimensions is investigated. Two versions of the theory are considered: one that allows at most triple pomeron interactions and the other that embodies an additional 2-->2 quartic Reggeon coupling. The behavior of the scattering amplitude at asymptotic rapidities is obtained in both cases. In an s-channel picture of the high energy scattering both models can be viewed as reaction-diffusion processes. We derive known results in Reggeon field theory rather easily using the reaction-diffusion formalism. We find that some results which are surprising from the Reggeon field theory point of view turn out to have a simple interpretation from the reaction-diffusion point of view.
[ { "created": "Wed, 20 Sep 2006 19:31:28 GMT", "version": "v1" } ]
2008-11-26
[ [ "Bondarenko", "S.", "" ], [ "Motyka", "L.", "" ], [ "Mueller", "A. H.", "" ], [ "Shoshi", "A. I.", "" ], [ "Xiao", "B. -W.", "" ] ]
The Reggeon field theory in zero transverse dimensions is investigated. Two versions of the theory are considered: one that allows at most triple pomeron interactions and the other that embodies an additional 2-->2 quartic Reggeon coupling. The behavior of the scattering amplitude at asymptotic rapidities is obtained in both cases. In an s-channel picture of the high energy scattering both models can be viewed as reaction-diffusion processes. We derive known results in Reggeon field theory rather easily using the reaction-diffusion formalism. We find that some results which are surprising from the Reggeon field theory point of view turn out to have a simple interpretation from the reaction-diffusion point of view.
hep-ph/9809260
Fabio Maltoni
F. Maltoni (Univ. Pisa)
Colour Octet effects in Quarkonium Physics
4 pages, Latex (espcrc2.sty), 1 figure. Talk presented at QCD'98, Montpellier, July 2-8, 1998; to appear in Nucl. Phys. B (Proc. Suppl.)
Nucl.Phys.Proc.Suppl. 74 (1999) 235-238
10.1016/S0920-5632(99)00170-X
null
hep-ph
null
The importance of including colour octet contributions in describing decay and production of quarkonium states is briefly discussed for two cases : the radiative decays of the $\Upsilon$ and the production of $J/\psi$ in the inclusive $B$ decays. It is shown how information on the non-perturbative matrix elements can be obtained by comparing the theoretical expressions computed at next-to-leading order in $\alpha_s$ with the experimental data.
[ { "created": "Fri, 4 Sep 1998 09:08:02 GMT", "version": "v1" } ]
2009-10-31
[ [ "Maltoni", "F.", "", "Univ. Pisa" ] ]
The importance of including colour octet contributions in describing decay and production of quarkonium states is briefly discussed for two cases : the radiative decays of the $\Upsilon$ and the production of $J/\psi$ in the inclusive $B$ decays. It is shown how information on the non-perturbative matrix elements can be obtained by comparing the theoretical expressions computed at next-to-leading order in $\alpha_s$ with the experimental data.
hep-ph/0010172
Eugene Zabrodin
L.V.Bravina (1,2), E.E.Zabrodin (1,2), S.A.Bass (3), M.Bleicher (4), M.Brandstetter(5), A. Faessler(1), C.Fuchs(1), W.Greiner(5), S.Soff(6), H.Stoecker(5) (1-Institute for Theoretical Physics, University of Tueubingen, Germany; 2-Institute for Nuclear Physics, Moscow State University, Russia; 3-National Superconducting Cyclotron Laboratory, Michigan State University, USA; 4-Nuclear Science Division, Lawrence Berkeley Laboratory, USA; 5-Institute for Theoretical Physics, University of Frankfurt, Germany; 6-Gesellschaft fuer Schwerionenforschung, Darmstadt, Germany)
Equation of state of resonance-rich matter in the central cell in heavy-ion collisions at $\sqrt{s}$=200 AGeV
LATEX, 21 pages incl. 7 figures
Phys.Rev. C63 (2001) 064902
10.1103/PhysRevC.63.064902
null
hep-ph nucl-ex nucl-th
null
The equilibration of hot and dense nuclear matter produced in the central cell of central Au+Au collisions at RHIC ($\sqrt{s}=200$ AGeV) energies is studied within a microscopic transport model. The pressure in the cell becomes isotropic at $t\approx 5$ fm/$c$ after beginning of the collision. Within the next 15 fm/$c$ the expansion of matter in the cell proceeds almost isentropically with the entropy per baryon ratio $S/A \approx 150$, and the equation of state in the $(P,\epsilon)$ plane has a very simple form, $P=0.15\epsilon$. Comparison with the statistical model of an ideal hadron gas indicates that the time $t \approx 20$ fm/c may be too short to reach the fully equilibrated state. Particularly, the creation of long-lived resonance-rich matter in the cell decelerates the relaxation to chemical equilibrium. This resonance-abundant state can be detected experimentally after the thermal freeze-out of particles.
[ { "created": "Mon, 16 Oct 2000 17:12:24 GMT", "version": "v1" } ]
2009-10-31
[ [ "Bravina", "L. V.", "" ], [ "Zabrodin", "E. E.", "" ], [ "Bass", "S. A.", "" ], [ "Bleicher", "M.", "" ], [ "Brandstetter", "M.", "" ], [ "Faessler", "A.", "" ], [ "Fuchs", "C.", "" ], [ "Greiner", "W.", "" ], [ "Soff", "S.", "" ], [ "Stoecker", "H.", "" ] ]
The equilibration of hot and dense nuclear matter produced in the central cell of central Au+Au collisions at RHIC ($\sqrt{s}=200$ AGeV) energies is studied within a microscopic transport model. The pressure in the cell becomes isotropic at $t\approx 5$ fm/$c$ after beginning of the collision. Within the next 15 fm/$c$ the expansion of matter in the cell proceeds almost isentropically with the entropy per baryon ratio $S/A \approx 150$, and the equation of state in the $(P,\epsilon)$ plane has a very simple form, $P=0.15\epsilon$. Comparison with the statistical model of an ideal hadron gas indicates that the time $t \approx 20$ fm/c may be too short to reach the fully equilibrated state. Particularly, the creation of long-lived resonance-rich matter in the cell decelerates the relaxation to chemical equilibrium. This resonance-abundant state can be detected experimentally after the thermal freeze-out of particles.
hep-ph/9910326
Thomas Hebbeker
Thomas Hebbeker
Can the sneutrino be the lightest supersymmetric particle ?
null
Phys.Lett. B470 (1999) 259-262
10.1016/S0370-2693(99)01313-1
Humboldt preprint HUB-EP-99/47
hep-ph
null
Within the framework of the constrained Minimal Supersymmetric extension of the Standard Model we show that recent LEP I limits on the invisible Z width exclude the possibility that the lightest sparticle is the sneutrino.
[ { "created": "Wed, 13 Oct 1999 15:55:30 GMT", "version": "v1" } ]
2009-10-31
[ [ "Hebbeker", "Thomas", "" ] ]
Within the framework of the constrained Minimal Supersymmetric extension of the Standard Model we show that recent LEP I limits on the invisible Z width exclude the possibility that the lightest sparticle is the sneutrino.
hep-ph/0404127
Gino Isidori
Gino Isidori, Christopher Smith, and Rene Unterdorfer
The rare decay KL -> pi0 mu+ mu- within the SM
20 pages, 8 figures
Eur.Phys.J.C36:57-66,2004
10.1140/epjc/s2004-01880-7
null
hep-ph
null
We present an updated analysis of the rare decay $K_{L}\to\pi^{0}\mu^{+}\mu^{-}$ within the Standard Model. In particular, we present the first complete calculation of the two-photon CP-conserving amplitude within Chiral Perturbation Theory, at the lowest non-trivial order. Our results confirm previous findings that the CP-conserving contribution to the decay rate cannot be neglected. By means of an explicit two-loop calculation, we show that this contribution can be estimated with sufficient accuracy compared to the CP-violating terms. We predict $\cB(K_L\to\pi^0\mu^+\mu^-)_{\rm SM}=(1.5\pm0.3)\times10^{-11}$, with approximately equal contributions from the CP-conserving component, the indirect-CP-violating term, and the interesting direct-CP-violating amplitude. The error of this prediction is mainly of parametric nature and could be substantially reduced with better data on the $K_{S}\to\pi^{0}\ell^{+}\ell^{-}$ modes. The Standard Model predictions for various differential distributions and the sensitivity to possible new-physics effects are also briefly discussed.
[ { "created": "Thu, 15 Apr 2004 15:05:26 GMT", "version": "v1" } ]
2008-11-26
[ [ "Isidori", "Gino", "" ], [ "Smith", "Christopher", "" ], [ "Unterdorfer", "Rene", "" ] ]
We present an updated analysis of the rare decay $K_{L}\to\pi^{0}\mu^{+}\mu^{-}$ within the Standard Model. In particular, we present the first complete calculation of the two-photon CP-conserving amplitude within Chiral Perturbation Theory, at the lowest non-trivial order. Our results confirm previous findings that the CP-conserving contribution to the decay rate cannot be neglected. By means of an explicit two-loop calculation, we show that this contribution can be estimated with sufficient accuracy compared to the CP-violating terms. We predict $\cB(K_L\to\pi^0\mu^+\mu^-)_{\rm SM}=(1.5\pm0.3)\times10^{-11}$, with approximately equal contributions from the CP-conserving component, the indirect-CP-violating term, and the interesting direct-CP-violating amplitude. The error of this prediction is mainly of parametric nature and could be substantially reduced with better data on the $K_{S}\to\pi^{0}\ell^{+}\ell^{-}$ modes. The Standard Model predictions for various differential distributions and the sensitivity to possible new-physics effects are also briefly discussed.