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hep-ph/9907315
null
B.A. Kniehl (Hamburg Univ.)
Higher-Order Effects on Inelastic J/psi Photoproduction
6 pages (Latex), 6 figures (Postscript). To appear in the proceedings of the workshop on Monte Carlo Generators for HERA Physics, DESY, Hamburg, 21 April 1998 - 5 February 1999, edited by T. Doyle, G. Grindhammer, G. Ingelman, and H. Jung
null
null
null
hep-ph
null
Approximately taking into account the higher-order effects due to multiple-gluon initial-state radiation, we extract from the latest Tevatron data of prompt J/psi hadroproduction the leading colour-octet matrix elements within the nonrelativistic-QCD (NRQCD) factorization formalism. We find that the matrix elements which describe the formation of J/psi mesons from colour-octet c c-bar pairs in the angular-momentum states (2S+1)^L_J = 1^S_0 and 3^P_J, with J = 0, 1, 2, which are responsible for the excess of the predicted cross section of inelastic J/psi photoproduction over the existing HERA data at high values of the inelasticity variable z, are significantly reduced. As a consequence, the Tevatron and HERA measurements of inclusive J/psi production are reconciled in the NRQCD framework.
[ { "created": "Mon, 12 Jul 1999 19:24:35 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kniehl", "B. A.", "", "Hamburg Univ." ] ]
Approximately taking into account the higher-order effects due to multiple-gluon initial-state radiation, we extract from the latest Tevatron data of prompt J/psi hadroproduction the leading colour-octet matrix elements within the nonrelativistic-QCD (NRQCD) factorization formalism. We find that the matrix elements which describe the formation of J/psi mesons from colour-octet c c-bar pairs in the angular-momentum states (2S+1)^L_J = 1^S_0 and 3^P_J, with J = 0, 1, 2, which are responsible for the excess of the predicted cross section of inelastic J/psi photoproduction over the existing HERA data at high values of the inelasticity variable z, are significantly reduced. As a consequence, the Tevatron and HERA measurements of inclusive J/psi production are reconciled in the NRQCD framework.
1702.06262
Andreas Krassnigg
T. Hilger, M. G\'omez-Rocha, A. Krassnigg, W. Lucha
Aspects of open-flavour mesons in a comprehensive DSBSE study
38 pages, 26 figures, 2 tables, revised according to reviewer comments
Eur. Phys. J. A (2017) 53: 213
10.1140/epja/i2017-12384-4
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Open-flavour meson studies are the necessary completion to any comprehensive investigation of quarkonia. We extend recent studies of quarkonia in the Dyson-Schwinger-Bethe-Salpeter-equation approach to explore their results for all possible flavour combinations. Within the inherent limitations of the setup, we present the most comprehensive results for meson masses and leptonic decay constants currently available and put them in perspective with respect to experiment and other approaches.
[ { "created": "Tue, 21 Feb 2017 04:45:18 GMT", "version": "v1" }, { "created": "Sat, 15 Jul 2017 07:37:25 GMT", "version": "v2" } ]
2017-11-01
[ [ "Hilger", "T.", "" ], [ "Gómez-Rocha", "M.", "" ], [ "Krassnigg", "A.", "" ], [ "Lucha", "W.", "" ] ]
Open-flavour meson studies are the necessary completion to any comprehensive investigation of quarkonia. We extend recent studies of quarkonia in the Dyson-Schwinger-Bethe-Salpeter-equation approach to explore their results for all possible flavour combinations. Within the inherent limitations of the setup, we present the most comprehensive results for meson masses and leptonic decay constants currently available and put them in perspective with respect to experiment and other approaches.
1411.5539
Gyuri Wolf
Gy. Wolf, P. Kov\'acs and Zs. Sz\'ep
Chiral phase transition in an extended linear sigma model: initial results
Presented at the Workshop on Unquenched Hadron Spectroscopy: Non-Perturbative Models and Methods of QCD vs. Experiment, At the occasion of Eef van Beveren's 70th birthday
null
null
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the scalar meson mass dependence on the chiral phase transition in the framework of an SU(3), (axial)vector meson extended linear sigma model with additional constituent quarks and Polyakov loops. We determine the parameters of the Lagrangian at zero temperature in a hybrid approach, where we treat the mesons at tree-level, while the constituent quarks at 1-loop level. We assume two nonzero scalar condensates and together with the Polyakov-loop variables we determine their temperature dependence according to the 1-loop level field equations.
[ { "created": "Thu, 20 Nov 2014 13:12:46 GMT", "version": "v1" } ]
2014-11-21
[ [ "Wolf", "Gy.", "" ], [ "Kovács", "P.", "" ], [ "Szép", "Zs.", "" ] ]
We investigate the scalar meson mass dependence on the chiral phase transition in the framework of an SU(3), (axial)vector meson extended linear sigma model with additional constituent quarks and Polyakov loops. We determine the parameters of the Lagrangian at zero temperature in a hybrid approach, where we treat the mesons at tree-level, while the constituent quarks at 1-loop level. We assume two nonzero scalar condensates and together with the Polyakov-loop variables we determine their temperature dependence according to the 1-loop level field equations.
hep-ph/0212356
Masashi Wakamatsu
M. Wakamatsu
Light-flavor sea-quark distributions in the nucleon in the SU(3) chiral quark soliton model (II) -- theoretical formalism --
Some errors in references were corrected
Phys.Rev. D67 (2003) 034006
10.1103/PhysRevD.67.034006
null
hep-ph
null
The path integral formulation is given to obtain quark and antiquark distribution functions in the nucleon within the flavor SU(3) version of the chiral quark soliton model. The basic model action is a straightforward generalization of the corresponding SU(2) one, except for one distinguishable feature, i.e. the presence of the SU(3) symmetry breaking term arising from the sizably large mass difference $\Delta m_s$ between the strange and nonstrange quarks. We treat this SU(3) symmetry breaking effect by relying upon the first order perturbation theory in the mass parameter $\Delta m_s$. We also address to the problem of ordering ambiguity of the relevant collective space operators, which arises in the evaluation of the parton distribution functions at the subleading order of $1/N_c$ expansion.
[ { "created": "Tue, 24 Dec 2002 05:38:52 GMT", "version": "v1" }, { "created": "Fri, 24 Jan 2003 07:14:20 GMT", "version": "v2" } ]
2009-11-07
[ [ "Wakamatsu", "M.", "" ] ]
The path integral formulation is given to obtain quark and antiquark distribution functions in the nucleon within the flavor SU(3) version of the chiral quark soliton model. The basic model action is a straightforward generalization of the corresponding SU(2) one, except for one distinguishable feature, i.e. the presence of the SU(3) symmetry breaking term arising from the sizably large mass difference $\Delta m_s$ between the strange and nonstrange quarks. We treat this SU(3) symmetry breaking effect by relying upon the first order perturbation theory in the mass parameter $\Delta m_s$. We also address to the problem of ordering ambiguity of the relevant collective space operators, which arises in the evaluation of the parton distribution functions at the subleading order of $1/N_c$ expansion.
1404.2219
Tolga Altinoluk
Tolga Altinoluk, N\'estor Armesto, Guillaume Beuf, Mauricio Mart\'inez and Carlos A. Salgado
Next-to-eikonal corrections in the CGC: gluon production and spin asymmetries in pA collisions
34 pages, new reference added, some typos corrected
null
10.1007/JHEP07(2014)068
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a new method to systematically include corrections to the eikonal approximation in the background field formalism. Specifically, we calculate the subleading, power-suppressed corrections due to the finite width of the target or the finite energy of the projectile. Such power-suppressed corrections involve Wilson lines decorated by gradients of the background field - thus related to the density - of the target. The method is of generic applicability. As a first example, we study single inclusive gluon production in pA collisions, and various related spin asymmetries, beyond the eikonal accuracy.
[ { "created": "Tue, 8 Apr 2014 17:19:53 GMT", "version": "v1" }, { "created": "Mon, 5 May 2014 15:08:09 GMT", "version": "v2" } ]
2015-06-19
[ [ "Altinoluk", "Tolga", "" ], [ "Armesto", "Néstor", "" ], [ "Beuf", "Guillaume", "" ], [ "Martínez", "Mauricio", "" ], [ "Salgado", "Carlos A.", "" ] ]
We present a new method to systematically include corrections to the eikonal approximation in the background field formalism. Specifically, we calculate the subleading, power-suppressed corrections due to the finite width of the target or the finite energy of the projectile. Such power-suppressed corrections involve Wilson lines decorated by gradients of the background field - thus related to the density - of the target. The method is of generic applicability. As a first example, we study single inclusive gluon production in pA collisions, and various related spin asymmetries, beyond the eikonal accuracy.
1902.02070
Jugal Lahkar
Jugal Lahkar, D. K. Choudhury and B. J. Hazarika
An Improved Analysis of Masses and Decay Constants of Heavy Flavour Mesons within Variational Approach
null
Communication in Theoretical Physics,2018
10.1088/0253-6102/71/1/49
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We employ the variational method to study the properties such as masses, decay constants, oscillation frequency and branching ratios of leptonic decays of heavy flavour mesons with linear cum coulomb Cornell potential. Gaussian function, Coulomb wave function and Airy function are taken as the trial wave-function of variational method in this study. Our analysis suggests that Gaussian trial wave-function provides results which are in close proximity with the experimental results. We also make a comparison with the results from QCD Sum rules and lattice QCD, as well as with recent PDG data.
[ { "created": "Wed, 6 Feb 2019 09:03:41 GMT", "version": "v1" } ]
2019-02-07
[ [ "Lahkar", "Jugal", "" ], [ "Choudhury", "D. K.", "" ], [ "Hazarika", "B. J.", "" ] ]
We employ the variational method to study the properties such as masses, decay constants, oscillation frequency and branching ratios of leptonic decays of heavy flavour mesons with linear cum coulomb Cornell potential. Gaussian function, Coulomb wave function and Airy function are taken as the trial wave-function of variational method in this study. Our analysis suggests that Gaussian trial wave-function provides results which are in close proximity with the experimental results. We also make a comparison with the results from QCD Sum rules and lattice QCD, as well as with recent PDG data.
hep-ph/9412306
Claudio Coriano
M.M. Block (Northwest), F. Halzen (Madison), B. Margolis (Mc Gill) and A.R. White (Argonne)
The High Energy Behavior of the Forward Scattering Parameters \sigma total $\rho$, and $B$
14 pages in latex, 8 figures included as a uuencoded file (NUHEP preprint 389)
null
null
null
hep-ph
null
Utilizing the most recent experimental data, we reanalyze high energy \pbar p and pp data, using two distinct (and {\em dissimilar}) analysis techniques: (1) asymptotic amplitude analysis, under the assumption that we have reached `asymptopia', and (2) an eikonal model whose amplitudes are designed to mimic real QCD amplitudes. The former gives strong evidence for a $\log \,(s/s_0)$ dependence at {\em current} energies and {\em not} $\log^2 (s/s_0)$, and demonstrates that odderons are {\em not} necessary to explain the experimental data. The latter gives a unitary model for extrapolation into true `asymptopia' from current energies, allowing us to predict the values of the total cross section at future supercolliders. Using our QCD-model, we obtain $\stot(16\,\, {\rm TeV})=109\pm4$\,mb and $\stot(40\,\, {\rm TeV})=124\pm4$\,mb.
[ { "created": "Thu, 15 Dec 1994 19:51:12 GMT", "version": "v1" } ]
2007-05-23
[ [ "Block", "M. M.", "", "Northwest" ], [ "Halzen", "F.", "", "Madison" ], [ "Margolis", "B.", "", "Mc Gill" ], [ "White", "A. R.", "", "Argonne" ] ]
Utilizing the most recent experimental data, we reanalyze high energy \pbar p and pp data, using two distinct (and {\em dissimilar}) analysis techniques: (1) asymptotic amplitude analysis, under the assumption that we have reached `asymptopia', and (2) an eikonal model whose amplitudes are designed to mimic real QCD amplitudes. The former gives strong evidence for a $\log \,(s/s_0)$ dependence at {\em current} energies and {\em not} $\log^2 (s/s_0)$, and demonstrates that odderons are {\em not} necessary to explain the experimental data. The latter gives a unitary model for extrapolation into true `asymptopia' from current energies, allowing us to predict the values of the total cross section at future supercolliders. Using our QCD-model, we obtain $\stot(16\,\, {\rm TeV})=109\pm4$\,mb and $\stot(40\,\, {\rm TeV})=124\pm4$\,mb.
2208.07907
Andrzej Czarnecki
M. Jamil Aslam, Wen Chen, Andrzej Czarnecki, Muhammad Mubasher, Connor Stephens
Positronium hydride decay into proton, electron, and one or zero photons
null
null
10.1103/PhysRevA.107.062816
Alberta Thy 6-22
hep-ph physics.atom-ph
http://creativecommons.org/licenses/by/4.0/
Decay rates of the positronium hydride PsH, a bound state of a proton, a positron, and two electrons, are determined for two rare channels, PsH $\to p^+ e^- \gamma$ and PsH $\to p^+ e^-$. Previous studies overestimated these rates by factors of about 2 and 700, respectively. We explain the physics underlying these wrong predictions. We confirm a range of static PsH properties, including the non-relativistic ground state energy, expectation values of inter-particle distances and their powers, and the three and four particle coalescence probabilities, using a variational method in the Gaussian basis.
[ { "created": "Tue, 16 Aug 2022 18:49:14 GMT", "version": "v1" } ]
2023-06-28
[ [ "Aslam", "M. Jamil", "" ], [ "Chen", "Wen", "" ], [ "Czarnecki", "Andrzej", "" ], [ "Mubasher", "Muhammad", "" ], [ "Stephens", "Connor", "" ] ]
Decay rates of the positronium hydride PsH, a bound state of a proton, a positron, and two electrons, are determined for two rare channels, PsH $\to p^+ e^- \gamma$ and PsH $\to p^+ e^-$. Previous studies overestimated these rates by factors of about 2 and 700, respectively. We explain the physics underlying these wrong predictions. We confirm a range of static PsH properties, including the non-relativistic ground state energy, expectation values of inter-particle distances and their powers, and the three and four particle coalescence probabilities, using a variational method in the Gaussian basis.
1206.4511
Qian Wang
Qian Wang, Gang Li, Xiao-Hai Liu, and Qiang Zhao
The nature of X(3900) and recognition of open charm effects
6 pages and 2 eps figures; Proceeding of Sixth International Conference on Quarks and Nuclear Physics - QNP 2012, Paris
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We identify open charm effects in a direct production process $e^+e^-\to J/\psi \pi^0$. A unique feature of this process is that the $D\bar{D}^*+c.c.$ threshold is located at a relatively isolated energy region, i.e. $\sim 3.876 \ \mathrm{GeV}$, which is far away from the well-established charmonia $\psi(3770)$ and $\psi(4040)$. Therefore, the cross section line-shape of this reaction provides an opportunity for singling out the open charm effects. A model-independent narrow enhancement between the thresholds of $D^0\bar{D}^{*0}+c.c.$ and $D^+D^{*-}+c.c.$ is predicted. This study can also help understand the X(3900) enhancement recently observed by the Belle and BaBar Collaboration in $e^+e^-\to D\bar{D}+c.c.$ We also show that the open charm effects play a crucial role for our understanding of the long-standing "$\rho\pi$ puzzle".
[ { "created": "Wed, 20 Jun 2012 14:26:49 GMT", "version": "v1" } ]
2012-06-21
[ [ "Wang", "Qian", "" ], [ "Li", "Gang", "" ], [ "Liu", "Xiao-Hai", "" ], [ "Zhao", "Qiang", "" ] ]
We identify open charm effects in a direct production process $e^+e^-\to J/\psi \pi^0$. A unique feature of this process is that the $D\bar{D}^*+c.c.$ threshold is located at a relatively isolated energy region, i.e. $\sim 3.876 \ \mathrm{GeV}$, which is far away from the well-established charmonia $\psi(3770)$ and $\psi(4040)$. Therefore, the cross section line-shape of this reaction provides an opportunity for singling out the open charm effects. A model-independent narrow enhancement between the thresholds of $D^0\bar{D}^{*0}+c.c.$ and $D^+D^{*-}+c.c.$ is predicted. This study can also help understand the X(3900) enhancement recently observed by the Belle and BaBar Collaboration in $e^+e^-\to D\bar{D}+c.c.$ We also show that the open charm effects play a crucial role for our understanding of the long-standing "$\rho\pi$ puzzle".
2101.09173
Yuki Fujimoto
Yuki Fujimoto, Kenji Fukushima, Yoshimasa Hidaka
Deconfining Phase Boundary of Rapidly Rotating Hot and Dense Matter and Analysis of Moment of Inertia
7 pages, 3 figures
null
10.1016/j.physletb.2021.136184
KEK-TH-2290, J-PARC-TH-0236, RIKEN-iTHEMS-Report-21
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the effect of rapid rotation on the phase diagram of hadronic matter. The energy dispersion relation is shifted by an effective chemical potential induced by rotation. This suggests that rotation should lower the critical temperature of chiral restoration, but it is still controversial how the deconfinement temperature should change as a function of angular velocity. We adopt the hadron resonance gas model as an approach free from fitting parameters. We identify the deconfinement from the thermodynamic behavior and find that rotation decreases the deconfinement temperature. We also discuss the spatial inhomogeneity of the pressure and give a semi-quantitative estimate of the moment of inertia.
[ { "created": "Fri, 22 Jan 2021 15:43:44 GMT", "version": "v1" } ]
2021-03-03
[ [ "Fujimoto", "Yuki", "" ], [ "Fukushima", "Kenji", "" ], [ "Hidaka", "Yoshimasa", "" ] ]
We discuss the effect of rapid rotation on the phase diagram of hadronic matter. The energy dispersion relation is shifted by an effective chemical potential induced by rotation. This suggests that rotation should lower the critical temperature of chiral restoration, but it is still controversial how the deconfinement temperature should change as a function of angular velocity. We adopt the hadron resonance gas model as an approach free from fitting parameters. We identify the deconfinement from the thermodynamic behavior and find that rotation decreases the deconfinement temperature. We also discuss the spatial inhomogeneity of the pressure and give a semi-quantitative estimate of the moment of inertia.
1403.2370
Joseph Conlon
Michele Cicoli, Joseph P. Conlon, M. C. David Marsh and Markus Rummel
A 3.55 keV Photon Line and its Morphology from a 3.55 keV ALP Line
6 pages
Phys. Rev. D 90, 023540 (2014)
10.1103/PhysRevD.90.023540
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Galaxy clusters can efficiently convert axion-like particles (ALPs) to photons. We propose that the recently claimed detection of a 3.55--3.57 keV line in the stacked spectra of a large number of galaxy clusters and the Andromeda galaxy may originate from the decay of either a scalar or fermionic $7.1$ keV dark matter species into an axion-like particle (ALP) of mass $m_{a} \lesssim 6\cdot 10^{-11}~{\rm eV}$, which subsequently converts to a photon in the cluster magnetic field. In contrast to models in which the photon line arises directly from dark matter decay or annihilation, this can explain the anomalous line strength in the Perseus cluster. As axion-photon conversion scales as $B^2$ and cool core clusters have high central magnetic fields, this model can also explains the observed peaking of the line emission in the cool cores of the Perseus, Ophiuchus and Centaurus clusters, as opposed to the much larger dark matter halos. We describe distinctive predictions of this scenario for future observations.
[ { "created": "Mon, 10 Mar 2014 19:56:43 GMT", "version": "v1" } ]
2014-07-30
[ [ "Cicoli", "Michele", "" ], [ "Conlon", "Joseph P.", "" ], [ "Marsh", "M. C. David", "" ], [ "Rummel", "Markus", "" ] ]
Galaxy clusters can efficiently convert axion-like particles (ALPs) to photons. We propose that the recently claimed detection of a 3.55--3.57 keV line in the stacked spectra of a large number of galaxy clusters and the Andromeda galaxy may originate from the decay of either a scalar or fermionic $7.1$ keV dark matter species into an axion-like particle (ALP) of mass $m_{a} \lesssim 6\cdot 10^{-11}~{\rm eV}$, which subsequently converts to a photon in the cluster magnetic field. In contrast to models in which the photon line arises directly from dark matter decay or annihilation, this can explain the anomalous line strength in the Perseus cluster. As axion-photon conversion scales as $B^2$ and cool core clusters have high central magnetic fields, this model can also explains the observed peaking of the line emission in the cool cores of the Perseus, Ophiuchus and Centaurus clusters, as opposed to the much larger dark matter halos. We describe distinctive predictions of this scenario for future observations.
1208.4085
Fredy Ochoa
R. Martinez and F. Ochoa
Production of multiple charged Higgs bosons in 3-3-1 models
10 figures, 2 tables
Phys. Rev. D. 86, 065030 (2012)
10.1103/PhysRevD.86.065030
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We undertake the study of the charged Higgs bosons predicted by the model with gauge symmetry $SU(3)_c \otimes SU(3)_L \otimes U(1)_X$. By considering Yukawa mixing couplings between small ($\sim$ GeV) and large ($\sim$ TeV) scales, we show that the hypercharge-one $H_1^{\pm}$ and hypercharge-two $H_2^{\pm}$ Higgs bosons predicted by the model, can be simultaneously produced in $pp$ collisions at different production rates. At low energy, the $H_1^{\pm}$ bosons exhibit the same properties as the charged Higgs bosons from a two Higgs doublet model (2HDM), while $H_2^{\pm}$ are additional like-charged Higgs bosons from the underlying 3-3-1 model. Thus, the identification of multiple like-charged Higgs boson resonances may test the compatibility of theoretical models with experimental data. We study $H_{1,2}^{\pm}$ pair and associated $tbH_{1,2}^{\pm}$ productions at CERN LHC collider. In particular, we obtain that pair production can be as large as the single production in gluon-gluon collisions due to the interchange of a heavy neutral $Z'$ gauge boson predicted by the model. By considering decays to leptons $H_{1,2}^{\pm} \rightarrow \tau \nu_{\tau}$, we obtain scenarios where small peaks of $H_{2}^{\pm}$-boson events in transverse mass distributions can be identified over the $H_{1}^{\pm}$ background.
[ { "created": "Mon, 20 Aug 2012 19:14:43 GMT", "version": "v1" } ]
2012-10-02
[ [ "Martinez", "R.", "" ], [ "Ochoa", "F.", "" ] ]
We undertake the study of the charged Higgs bosons predicted by the model with gauge symmetry $SU(3)_c \otimes SU(3)_L \otimes U(1)_X$. By considering Yukawa mixing couplings between small ($\sim$ GeV) and large ($\sim$ TeV) scales, we show that the hypercharge-one $H_1^{\pm}$ and hypercharge-two $H_2^{\pm}$ Higgs bosons predicted by the model, can be simultaneously produced in $pp$ collisions at different production rates. At low energy, the $H_1^{\pm}$ bosons exhibit the same properties as the charged Higgs bosons from a two Higgs doublet model (2HDM), while $H_2^{\pm}$ are additional like-charged Higgs bosons from the underlying 3-3-1 model. Thus, the identification of multiple like-charged Higgs boson resonances may test the compatibility of theoretical models with experimental data. We study $H_{1,2}^{\pm}$ pair and associated $tbH_{1,2}^{\pm}$ productions at CERN LHC collider. In particular, we obtain that pair production can be as large as the single production in gluon-gluon collisions due to the interchange of a heavy neutral $Z'$ gauge boson predicted by the model. By considering decays to leptons $H_{1,2}^{\pm} \rightarrow \tau \nu_{\tau}$, we obtain scenarios where small peaks of $H_{2}^{\pm}$-boson events in transverse mass distributions can be identified over the $H_{1}^{\pm}$ background.
hep-ph/9912452
Dr. Dubravko Klabucar
B. Bistrovic (Old Dominion U. & Jefferson Lab), D. Klabucar (Zagreb Uni v.)
Anomalous gamma -> 3 pi amplitude in a bound-state approach
14 pages, 3 figures, corrected some typos, which makes this version identical to the published one in Phys.Lett. B478 (2000) 127-136
Phys.Lett.B478:127-136,2000
10.1016/S0370-2693(00)00241-0
ZTF-99/13, JLAB-THY-00-03
hep-ph nucl-th
null
The form factor for the anomalous process gamma pi^+ -> pi^+ pi^0, which is presently being measured at CEBAF, is calculated in the Schwinger-Dyson approach in conjunction with an impulse approximation. The form factors obtained by us are compared with the ones predicted by the simple constituent quark loop model, vector meson dominance and chiral perturbation theory, as well as the scarce already available data.
[ { "created": "Tue, 21 Dec 1999 22:41:20 GMT", "version": "v1" }, { "created": "Thu, 3 Feb 2000 20:21:34 GMT", "version": "v2" }, { "created": "Tue, 2 May 2000 12:18:25 GMT", "version": "v3" } ]
2008-11-26
[ [ "Bistrovic", "B.", "", "Old Dominion U. & Jefferson Lab" ], [ "Klabucar", "D.", "", "Zagreb\n Uni v." ] ]
The form factor for the anomalous process gamma pi^+ -> pi^+ pi^0, which is presently being measured at CEBAF, is calculated in the Schwinger-Dyson approach in conjunction with an impulse approximation. The form factors obtained by us are compared with the ones predicted by the simple constituent quark loop model, vector meson dominance and chiral perturbation theory, as well as the scarce already available data.
1010.0028
John R. Hiller
J.R. Hiller
Pauli-Villars regularization of field theories on the light front
8 pages, PoS.cls; to appear in the proceedings of Light Cone 2010, Valencia, Spain, June 14-18, 2010
AIP Conf.Proc.1317:156-161,2011; PoS LC2010:009,2010
10.1063/1.3536550
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Four-dimensional quantum field theories generally require regularization to be well defined. This can be done in various ways, but here we focus on Pauli--Villars (PV) regularization and apply it to nonperturbative calculations of bound states. The philosophy is to introduce enough PV fields to the Lagrangian to regulate the theory perturbatively, including preservation of symmetries, and assume that this is sufficient for the nonperturbative case. The numerical methods usually necessary for nonperturbative bound-state problems are then applied to a finite theory that has the original symmetries. The bound-state problem is formulated as a mass eigenvalue problem in terms of the light-front Hamiltonian. Applications to quantum electrodynamics are discussed.
[ { "created": "Thu, 30 Sep 2010 22:23:56 GMT", "version": "v1" } ]
2011-03-10
[ [ "Hiller", "J. R.", "" ] ]
Four-dimensional quantum field theories generally require regularization to be well defined. This can be done in various ways, but here we focus on Pauli--Villars (PV) regularization and apply it to nonperturbative calculations of bound states. The philosophy is to introduce enough PV fields to the Lagrangian to regulate the theory perturbatively, including preservation of symmetries, and assume that this is sufficient for the nonperturbative case. The numerical methods usually necessary for nonperturbative bound-state problems are then applied to a finite theory that has the original symmetries. The bound-state problem is formulated as a mass eigenvalue problem in terms of the light-front Hamiltonian. Applications to quantum electrodynamics are discussed.
2207.03303
Gon\c{c}alo Quinta
Gon\c{c}alo M. Quinta, Alexandre Sousa, Yasser Omar
Predicting leptonic CP violation via minimization of neutrino entanglement
5 pages, 3 figures
null
null
null
hep-ph hep-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show how a minimization principle of quantum entanglement between the oscillating flavors of a neutrino leads to a unique prediction for the CP-violation phase in the neutrino sector without assuming extra symmetries in the Standard Model. We find a theoretical prediction consistent with either no CP-violation or a very small presence of it.
[ { "created": "Thu, 7 Jul 2022 13:59:55 GMT", "version": "v1" } ]
2022-07-08
[ [ "Quinta", "Gonçalo M.", "" ], [ "Sousa", "Alexandre", "" ], [ "Omar", "Yasser", "" ] ]
We show how a minimization principle of quantum entanglement between the oscillating flavors of a neutrino leads to a unique prediction for the CP-violation phase in the neutrino sector without assuming extra symmetries in the Standard Model. We find a theoretical prediction consistent with either no CP-violation or a very small presence of it.
1310.1209
Helmut Satz
Helmut Satz
Probing the States of Matter in QCD
20 pages, 14 figures; survey talk given at the 26th International Symosium on Lepton-Photon Interactions at High Energies, San Francisco, California, USA, June 24 - 29, 2013
null
10.1142/S0217751X13300433
BI-TP 2013/22
hep-ph hep-ex hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The ultimate aim of high energy heavy ion collisions is to study quark deconfinement and the quark-gluon plasma predicted by quantum chromodynamics. This requires the identification of observables calculable in QCD and measurable in heavy ion collisions. I concentrate on three such phenomena, related to specific features of strongly interacting matter. The observed pattern of hadrosynthesis corresponds to that of an ideal resonance gas in equilibrium at the pseudo-critical temperature determined in QCD. The critical behavior of QCD is encoded in the fluctuation patterns of conserved quantum numbers, which are presently being measured. The temperature of the quark-gluon plasma can be determined by the dissociation patterns of the different quarkonium states, now under study at the LHC for both charmonia and bottomonia.
[ { "created": "Fri, 4 Oct 2013 09:18:17 GMT", "version": "v1" } ]
2015-06-17
[ [ "Satz", "Helmut", "" ] ]
The ultimate aim of high energy heavy ion collisions is to study quark deconfinement and the quark-gluon plasma predicted by quantum chromodynamics. This requires the identification of observables calculable in QCD and measurable in heavy ion collisions. I concentrate on three such phenomena, related to specific features of strongly interacting matter. The observed pattern of hadrosynthesis corresponds to that of an ideal resonance gas in equilibrium at the pseudo-critical temperature determined in QCD. The critical behavior of QCD is encoded in the fluctuation patterns of conserved quantum numbers, which are presently being measured. The temperature of the quark-gluon plasma can be determined by the dissociation patterns of the different quarkonium states, now under study at the LHC for both charmonia and bottomonia.
hep-ph/9404220
null
Eilam Gross, Bernd A. Kniehl and Gustavo Wolf
Production and decay of the Standard Model Higgs Bososn at LEP200
27 pages
Z.Phys. C63 (1994) 417-426; Erratum-ibid. C66 (1995) 321-322
10.1007/BF01580322
DESY 94-035; WIS-94/15/MAR-PH
hep-ph
null
We collect and update theoretical predictions for the production rate and decay branching fractions of the Standard Model Higgs boson that will be relevant for the Higgs search at LEP200. We make full use of the present knowledge of radiative corrections. We estimate the systematics arising from theoretical and experimental uncertainties.
[ { "created": "Wed, 6 Apr 1994 10:09:36 GMT", "version": "v1" } ]
2009-10-28
[ [ "Gross", "Eilam", "" ], [ "Kniehl", "Bernd A.", "" ], [ "Wolf", "Gustavo", "" ] ]
We collect and update theoretical predictions for the production rate and decay branching fractions of the Standard Model Higgs boson that will be relevant for the Higgs search at LEP200. We make full use of the present knowledge of radiative corrections. We estimate the systematics arising from theoretical and experimental uncertainties.
hep-ph/0307012
Siannah Penaranda
Jaume Guasch, Wolfgang Hollik, Siannah Penaranda
Some results on the distinction of Higgs boson models
LaTeX, 5 pages, 3 figures, Based on talk given at Second Workshop of the Extended ECFA/DESY Study, Saint Malo, April 12-15, 2002
null
null
MPI-PhT/2003-28, PSI-PR-03-08, LC-TH-2003-043
hep-ph
null
We present results on the analysis of the ratio of branching ratios $R=BR(H->b\bar{b})/BR(H->\tau^+\tau^-)$ of Higgs boson decays as a discriminant quantity between supersymmetric and non-supersymmetric models. A detailed analysis in the effective Lagrangian approach shows how one could discriminate between models at the Large Hadron Collider and the $e^+e^-$ Linear Collider at 500 GeV center of mass energy.
[ { "created": "Tue, 1 Jul 2003 10:02:49 GMT", "version": "v1" } ]
2007-05-23
[ [ "Guasch", "Jaume", "" ], [ "Hollik", "Wolfgang", "" ], [ "Penaranda", "Siannah", "" ] ]
We present results on the analysis of the ratio of branching ratios $R=BR(H->b\bar{b})/BR(H->\tau^+\tau^-)$ of Higgs boson decays as a discriminant quantity between supersymmetric and non-supersymmetric models. A detailed analysis in the effective Lagrangian approach shows how one could discriminate between models at the Large Hadron Collider and the $e^+e^-$ Linear Collider at 500 GeV center of mass energy.
1908.07525
Yu-Dai Tsai
Yu-Dai Tsai, Patrick deNiverville, Ming Xiong Liu
The High-Energy Frontier of the Intensity Frontier: Closing the Dark Photon, Inelastic Dark Matter, and Muon g-2 Windows
19 pages, 4 figures
Phys. Rev. Lett. 126, 181801 (2021)
10.1103/PhysRevLett.126.181801
FERMILAB-PUB-19-393-A-PPD
hep-ph astro-ph.CO hep-ex hep-th
http://creativecommons.org/licenses/by-nc-sa/4.0/
We study hidden sector and long-lived particles at past (CHARM and NuCal), present (NA62 and SeaQuest/DarkQuest), and future (LongQuest) experiments that are at the high-energy frontier of the intensity frontier. We focus on exploring the minimal vector portal and variere-lifetime particles (VLP). VLP models have mostly been devised to explain experimental anomalies while avoiding existing constraints, and we demonstrate that proton fixed-target experiments provide one of the most powerful probes for the sub-GeV to few GeV mass range of the VLP models, using inelastic dark matter (iDM) as an example. We consider an iDM model with small mass splitting that yields the observed dark matter (DM) relic abundance, and a scenario with a sizable mass splitting that can also explain the muon $g-2$ anomaly. We set strong limits based on the CHARM and NuCal experiments, which come close to excluding iDM as full-abundance thermal DM candidates in the MeV to GeV mass range, for the mass arrangements and small mass splittings we consider. We also study the future projections based on NA62 and SeaQuest/DarkQuest, and update the constraints of the minimal dark photon parameter space. We found that NuCal sets the only existing constraint in $\epsilon \sim 10^{-8} - 10^{-4}$ regime reaching $\sim$ 800 MeV in dark photon mass due to the resonant enhancement of the proton bremsstrahlung production. Finally, we propose LongQuest, a three-stage thorough retool of the SeaQuest experiment with short ($\lesssim$ 5 m), medium ($\sim$ 5 m), and long baseline ($\gtrsim$ 35 m) tracking stations/detectors, as a multi-purpose machine to explore dark sector particles with a wide range of couplings to the standard model sector.
[ { "created": "Tue, 20 Aug 2019 18:00:00 GMT", "version": "v1" } ]
2021-09-20
[ [ "Tsai", "Yu-Dai", "" ], [ "deNiverville", "Patrick", "" ], [ "Liu", "Ming Xiong", "" ] ]
We study hidden sector and long-lived particles at past (CHARM and NuCal), present (NA62 and SeaQuest/DarkQuest), and future (LongQuest) experiments that are at the high-energy frontier of the intensity frontier. We focus on exploring the minimal vector portal and variere-lifetime particles (VLP). VLP models have mostly been devised to explain experimental anomalies while avoiding existing constraints, and we demonstrate that proton fixed-target experiments provide one of the most powerful probes for the sub-GeV to few GeV mass range of the VLP models, using inelastic dark matter (iDM) as an example. We consider an iDM model with small mass splitting that yields the observed dark matter (DM) relic abundance, and a scenario with a sizable mass splitting that can also explain the muon $g-2$ anomaly. We set strong limits based on the CHARM and NuCal experiments, which come close to excluding iDM as full-abundance thermal DM candidates in the MeV to GeV mass range, for the mass arrangements and small mass splittings we consider. We also study the future projections based on NA62 and SeaQuest/DarkQuest, and update the constraints of the minimal dark photon parameter space. We found that NuCal sets the only existing constraint in $\epsilon \sim 10^{-8} - 10^{-4}$ regime reaching $\sim$ 800 MeV in dark photon mass due to the resonant enhancement of the proton bremsstrahlung production. Finally, we propose LongQuest, a three-stage thorough retool of the SeaQuest experiment with short ($\lesssim$ 5 m), medium ($\sim$ 5 m), and long baseline ($\gtrsim$ 35 m) tracking stations/detectors, as a multi-purpose machine to explore dark sector particles with a wide range of couplings to the standard model sector.
hep-ph/9602362
Veretin Oleg
O.V. Teryaev, O.L. Veretin, (Joint Institute for Nuclear Researches, Dubna)
Quark Mass Corrections to the Bjorken and Gross--Llewellyn-Smith Sum Rules
8 pages, 1 Postscript figure, uses epsf.sty
null
null
null
hep-ph
null
Quark mass corrections to the spin partonic structure function g_1(x,Q^2) and function F_3(x,Q^2) are obtained at the order O(alpha_s) along with the coefficient functions C^{(A)} and C^{(V)} related to the Bjorken and Gross--Llewellyn-Smith sum rules. In the massless limit the difference between F_3 and g_1 is encountered to be (alpha_s/\pi)*CF*(1-x). The results for the functions C^{(A)} and C^{(V)} at m=0 agree with the previous MS-scheme calculations C^{(A)}=C^{(V)}=1-(3*alpha_s/4\pi)*CF.
[ { "created": "Wed, 21 Feb 1996 13:12:21 GMT", "version": "v1" }, { "created": "Fri, 23 Feb 1996 14:21:03 GMT", "version": "v2" } ]
2008-02-03
[ [ "Teryaev", "O. V.", "" ], [ "Veretin", "O. L.", "" ] ]
Quark mass corrections to the spin partonic structure function g_1(x,Q^2) and function F_3(x,Q^2) are obtained at the order O(alpha_s) along with the coefficient functions C^{(A)} and C^{(V)} related to the Bjorken and Gross--Llewellyn-Smith sum rules. In the massless limit the difference between F_3 and g_1 is encountered to be (alpha_s/\pi)*CF*(1-x). The results for the functions C^{(A)} and C^{(V)} at m=0 agree with the previous MS-scheme calculations C^{(A)}=C^{(V)}=1-(3*alpha_s/4\pi)*CF.
hep-ph/0001251
Nguyen Van Hieu
N. V. Hieu, N. H. Son, N. V. Thanh and H. B. Thang (Institute of Physics, Vietnam)
Quark-Antiquark Pairing Induced by Instantons in QCD
15 pages, LaTeX2E, 8 figures
null
null
null
hep-ph
null
The quark-antiquark pairing due to the four-fermion direct coupling induced by the instantons in QCD is studied in the framework of the functional integral method. The integral equations for the order parameters are derived. Several classes of the solutions of these non-linear equations are considered in details. Their implications for the dynamical symmetry breakings are discussed
[ { "created": "Tue, 25 Jan 2000 03:16:25 GMT", "version": "v1" } ]
2007-05-23
[ [ "Hieu", "N. V.", "", "Institute of\n Physics, Vietnam" ], [ "Son", "N. H.", "", "Institute of\n Physics, Vietnam" ], [ "Thanh", "N. V.", "", "Institute of\n Physics, Vietnam" ], [ "Thang", "H. B.", "", "Institute of\n Physics, Vietnam" ] ]
The quark-antiquark pairing due to the four-fermion direct coupling induced by the instantons in QCD is studied in the framework of the functional integral method. The integral equations for the order parameters are derived. Several classes of the solutions of these non-linear equations are considered in details. Their implications for the dynamical symmetry breakings are discussed
0704.3311
Andrey Radzhabov E
A. E. Radzhabov, M. K. Volkov and N. G. Kornakov
rho(omega)-> pi^0 pi^0 gamma, rho(omega) -> eta pi^0 gamma decays in the local quark Nambu--Jona-Lasinio model
6 pages, 5 figures
Phys.Atom.Nucl.71:1481-1486,2008
10.1134/S1063778808080206
null
hep-ph
null
The branching ratios and photon spectra of the rare processes rho(omega)-> pi^0 pi^0 gamma, rho(omega) -> eta pi^0 gamma are calculated in the framework of the standard local quark Nambu--Jona-Lasinio (NJL) model. Three types of diagrams are considered: the quark box and the pole diagrams with scalar (sigma,a_0(980)) and vector (rho,omega) mesons. The obtained estimations for the widths of the processes rho(omega)-> pi^0 pi^0 gamma are in satisfactory agreement with existing experimental data. Predictions are made for the widths of the processes rho(omega) -> eta pi^0 gamma.
[ { "created": "Wed, 25 Apr 2007 06:08:08 GMT", "version": "v1" } ]
2008-11-26
[ [ "Radzhabov", "A. E.", "" ], [ "Volkov", "M. K.", "" ], [ "Kornakov", "N. G.", "" ] ]
The branching ratios and photon spectra of the rare processes rho(omega)-> pi^0 pi^0 gamma, rho(omega) -> eta pi^0 gamma are calculated in the framework of the standard local quark Nambu--Jona-Lasinio (NJL) model. Three types of diagrams are considered: the quark box and the pole diagrams with scalar (sigma,a_0(980)) and vector (rho,omega) mesons. The obtained estimations for the widths of the processes rho(omega)-> pi^0 pi^0 gamma are in satisfactory agreement with existing experimental data. Predictions are made for the widths of the processes rho(omega) -> eta pi^0 gamma.
2110.06941
Gauthier Durieux
Gauthier Durieux, Matthew McCullough, Ennio Salvioni
Gegenbauer Goldstones
20 pages, 5 figures, v2: minor changes, matches the published version
JHEP 01 (2022) 076
10.1007/JHEP01(2022)076
CERN-TH-2021-141
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
We investigate radiatively stable classes of pseudo-Nambu-Goldstone boson (pNGB) potentials for approximate spontaneously broken $\mathrm{SO}(N+1)\to\mathrm{SO}(N)$. Using both the one-loop effective action and symmetry, it is shown that a Gegenbauer polynomial potential is radiatively stable, being effectively an `eigenfunction' from a radiative perspective. In Gegenbauer pNGB models, one naturally and automatically obtains $v \propto f/n$, where $n\in 2\mathbb{Z}$ is the order of the Gegenbauer polynomial. For a Gegenbauer Higgs boson, this breaks the usual correlation between Higgs coupling corrections and `$v/f$' tuning. Based on this, we argue that to conclusively determine whether or not the Higgs is a composite pNGB in scenarios with up to $\mathcal{O}(10\%)$ fine-tuning will require going beyond both the Higgs coupling precision and heavy resonance mass reach of the High-Luminosity LHC.
[ { "created": "Wed, 13 Oct 2021 18:00:02 GMT", "version": "v1" }, { "created": "Thu, 20 Jan 2022 18:07:25 GMT", "version": "v2" } ]
2022-01-21
[ [ "Durieux", "Gauthier", "" ], [ "McCullough", "Matthew", "" ], [ "Salvioni", "Ennio", "" ] ]
We investigate radiatively stable classes of pseudo-Nambu-Goldstone boson (pNGB) potentials for approximate spontaneously broken $\mathrm{SO}(N+1)\to\mathrm{SO}(N)$. Using both the one-loop effective action and symmetry, it is shown that a Gegenbauer polynomial potential is radiatively stable, being effectively an `eigenfunction' from a radiative perspective. In Gegenbauer pNGB models, one naturally and automatically obtains $v \propto f/n$, where $n\in 2\mathbb{Z}$ is the order of the Gegenbauer polynomial. For a Gegenbauer Higgs boson, this breaks the usual correlation between Higgs coupling corrections and `$v/f$' tuning. Based on this, we argue that to conclusively determine whether or not the Higgs is a composite pNGB in scenarios with up to $\mathcal{O}(10\%)$ fine-tuning will require going beyond both the Higgs coupling precision and heavy resonance mass reach of the High-Luminosity LHC.
1206.3796
Juan Jose Sanz-Cillero
J. J. Sanz-Cillero
Anomalous AV*V Green's function in soft-wall AdS/QCD
5 pages. Talk given in the Sixth International Conference on Quarks and Nuclear Physics, April 16-20 2012, Palaiseau, France
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this talk we study the Green's function of two vector and one axial-vector currents within the soft-wall anti-de-Sitter (AdS) model of Qunatum Chromodynamics (QCD), with a quadratic dilaton and chiral symmetry broken through a field X which gains a vacuum expectation value. We compare our predictions at high energies with the Operator Product Expansion both in the massless quark limit and for mq different from 0. The soft-wall model yields a zero magnetic susceptibility chi=0 and some problems are found in the case with mq different from 0. We also discuss the relation proposed by Son and Yamamoto between the AV*V and VV-AA correlators, which is not obeyed at high energies in soft wall AdS/QCD.
[ { "created": "Sun, 17 Jun 2012 21:28:13 GMT", "version": "v1" } ]
2012-06-19
[ [ "Sanz-Cillero", "J. J.", "" ] ]
In this talk we study the Green's function of two vector and one axial-vector currents within the soft-wall anti-de-Sitter (AdS) model of Qunatum Chromodynamics (QCD), with a quadratic dilaton and chiral symmetry broken through a field X which gains a vacuum expectation value. We compare our predictions at high energies with the Operator Product Expansion both in the massless quark limit and for mq different from 0. The soft-wall model yields a zero magnetic susceptibility chi=0 and some problems are found in the case with mq different from 0. We also discuss the relation proposed by Son and Yamamoto between the AV*V and VV-AA correlators, which is not obeyed at high energies in soft wall AdS/QCD.
1909.01990
Aur\'elien Carle
A. Carle, N. Chanon, and S. Perries
Probing Lorentz Invariance With Top Pair Production at the LHC and Future Colliders
Presented at the Eighth Meeting on CPT and Lorentz Symmetry, Bloomington, Indiana, May 12-16, 2019
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This article presents prospects for Lorentz-violation searches with $t\bar{t}$ at the LHC and future colliders. After a short presentation of the Standard-Model Extension as a Lorentz-symmetry-breaking effective field theory, we will focus on $t\bar{t}$ production. We study the impact of Lorentz violation as a function of center-of-mass energy and evaluate the sensitivity of collider experiments to this signal.
[ { "created": "Wed, 4 Sep 2019 13:34:45 GMT", "version": "v1" } ]
2019-09-06
[ [ "Carle", "A.", "" ], [ "Chanon", "N.", "" ], [ "Perries", "S.", "" ] ]
This article presents prospects for Lorentz-violation searches with $t\bar{t}$ at the LHC and future colliders. After a short presentation of the Standard-Model Extension as a Lorentz-symmetry-breaking effective field theory, we will focus on $t\bar{t}$ production. We study the impact of Lorentz violation as a function of center-of-mass energy and evaluate the sensitivity of collider experiments to this signal.
2009.02044
David M\"uller
Andreas Ipp and David I. M\"uller
Progress on 3+1D Glasma simulations
9 pages, 5 figures, invited contribution to EPJA topical issue "Theory of Hot Matter and Relativistic Heavy-Ion Collisions (THOR)"
Eur. Phys. J. A 56, 243 (2020)
10.1140/epja/s10050-020-00241-6
null
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review our progress on 3+1D Glasma simulations to describe the earliest stages of heavy-ion collisions. In our simulations we include nuclei with finite longitudinal extent and describe the collision process as well as the evolution of the strongly interacting gluonic fields in the laboratory frame in 3+1 dimensions using the colored particle-in-cell method. This allows us to compute the 3+1 dimensional Glasma energy-momentum tensor, whose rapidity dependence can be compared to experimental pion multiplicity data from RHIC. An improved scheme cures the numerical Cherenkov instability and paves the way for simulations at higher energies used at LHC.
[ { "created": "Fri, 4 Sep 2020 07:56:48 GMT", "version": "v1" } ]
2020-10-05
[ [ "Ipp", "Andreas", "" ], [ "Müller", "David I.", "" ] ]
We review our progress on 3+1D Glasma simulations to describe the earliest stages of heavy-ion collisions. In our simulations we include nuclei with finite longitudinal extent and describe the collision process as well as the evolution of the strongly interacting gluonic fields in the laboratory frame in 3+1 dimensions using the colored particle-in-cell method. This allows us to compute the 3+1 dimensional Glasma energy-momentum tensor, whose rapidity dependence can be compared to experimental pion multiplicity data from RHIC. An improved scheme cures the numerical Cherenkov instability and paves the way for simulations at higher energies used at LHC.
1705.05337
Zhang Hong-Fei
Zhan Sun, Hong-Fei Zhang
QCD Corrections to the Color-singlet $J/\psi$ Production in Deeply Inelastic Scattering at HERA
null
Phys. Rev. D 96, 091502 (2017)
10.1103/PhysRevD.96.091502
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the first study of the QCD corrections to the color-singlet (CS) $J/\psi$ production in deeply inelastic $ep$ scattering at HERA. The $K$-factor ranges from $0.85$ to $2.38$ in the kinematic regions we study. In low transverse momentum regions, the $K$-factors is even smaller, and close to 1, which indicates good convergence of the perturbative expansion. With the QCD corrections, the CS cross section is still below the data. At least at QCD next-to-leading order, the color-octet mechanism is necessary to describe the data.
[ { "created": "Mon, 15 May 2017 17:11:33 GMT", "version": "v1" }, { "created": "Fri, 3 Nov 2017 13:36:55 GMT", "version": "v2" } ]
2017-11-15
[ [ "Sun", "Zhan", "" ], [ "Zhang", "Hong-Fei", "" ] ]
We present the first study of the QCD corrections to the color-singlet (CS) $J/\psi$ production in deeply inelastic $ep$ scattering at HERA. The $K$-factor ranges from $0.85$ to $2.38$ in the kinematic regions we study. In low transverse momentum regions, the $K$-factors is even smaller, and close to 1, which indicates good convergence of the perturbative expansion. With the QCD corrections, the CS cross section is still below the data. At least at QCD next-to-leading order, the color-octet mechanism is necessary to describe the data.
1601.03091
Stephon Alexander
Stephon Alexander, Lee Smolin
Enhanced color gauge invariance and a new di-photon state at the LHC
13 pages, 1 figure
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose to interpret the possible resonance seen in di-photons at the LHC at 750 Gev as a bound state of a new pair of heavy gluons associated with an enhanced color gauge invariance. These have a conservation law which enforces their production and decay in pairs and hence requires that the leading coupling to quarks is quadratically through a dimension 5 operator. One way to realize these hypotheses is if the SU(3) color gauge invariance is enhanced to SL(3, C), while at the same time promoting the internal metric, which picks out what is a unitary transformation, to a dynamical degree of freedom. This theory was first proposed by Cahill[3], Dell[4], Kim and Zee[5], and Julia and Luciani[6]. The dynamical internal metric spontaneously breaks SL(3,C) to SU(3) giving a mass to the vector bosons associated with the generators in SL(3,C)/SU(3). The coupling to the internal metric also ensures that the energy is bounded from below. The new state is produced by gluon fusion and decays to a pair of photons via a direct coupling to a new set of vector quarks allowed by the symmetries.
[ { "created": "Tue, 12 Jan 2016 22:29:35 GMT", "version": "v1" }, { "created": "Tue, 26 Jan 2016 15:52:32 GMT", "version": "v2" }, { "created": "Thu, 17 Mar 2016 19:08:08 GMT", "version": "v3" } ]
2016-03-18
[ [ "Alexander", "Stephon", "" ], [ "Smolin", "Lee", "" ] ]
We propose to interpret the possible resonance seen in di-photons at the LHC at 750 Gev as a bound state of a new pair of heavy gluons associated with an enhanced color gauge invariance. These have a conservation law which enforces their production and decay in pairs and hence requires that the leading coupling to quarks is quadratically through a dimension 5 operator. One way to realize these hypotheses is if the SU(3) color gauge invariance is enhanced to SL(3, C), while at the same time promoting the internal metric, which picks out what is a unitary transformation, to a dynamical degree of freedom. This theory was first proposed by Cahill[3], Dell[4], Kim and Zee[5], and Julia and Luciani[6]. The dynamical internal metric spontaneously breaks SL(3,C) to SU(3) giving a mass to the vector bosons associated with the generators in SL(3,C)/SU(3). The coupling to the internal metric also ensures that the energy is bounded from below. The new state is produced by gluon fusion and decays to a pair of photons via a direct coupling to a new set of vector quarks allowed by the symmetries.
hep-ph/0211344
Abilio De Freitas
Z. Bern (UCLA), A. De Freitas (DESY, Zeuthen), L. Dixon (SLAC)
Two-loop corrections to $gg \to \gamma \gamma$
Presented at RADCOR 2002/Loops and Legs in Quantum Field Theory (September 2002, Kloster Banz, Germany)
Nucl.Phys.Proc.Suppl.116:173-177,2003
10.1016/S0920-5632(03)80164-0
DESY 02-202, UCLA/02/TEP/35, SLAC-PUB-9578
hep-ph
null
An overview of the calculation of the two-loop helicity amplitudes for scattering of two gluons into two photons is presented. These matrix elements enter into the recent improved calculation of the QCD background to Higgs boson decay into a pair of photons, which is the preferred search mode at the LHC for the case of a light Higgs boson.
[ { "created": "Thu, 21 Nov 2002 23:30:11 GMT", "version": "v1" } ]
2010-11-15
[ [ "Bern", "Z.", "", "UCLA" ], [ "De Freitas", "A.", "", "DESY, Zeuthen" ], [ "Dixon", "L.", "", "SLAC" ] ]
An overview of the calculation of the two-loop helicity amplitudes for scattering of two gluons into two photons is presented. These matrix elements enter into the recent improved calculation of the QCD background to Higgs boson decay into a pair of photons, which is the preferred search mode at the LHC for the case of a light Higgs boson.
1102.3487
Yuede Chen
Y. D. Chen and C. F. Qiao
Baryonium Study in Heavy Baryon Chiral Perturbation Theory
25 pages, 10 figures, revised version for publication in Phys. Rev. D
null
10.1103/PhysRevD.85.034034
null
hep-ph
http://creativecommons.org/licenses/by/3.0/
To see whether heavy baryon and anti-baryon can form a bound state, the heavy baryonium, we study the interaction potential between them in terms of heavy baryon perturbation theory. The obtained potential is applied to calculate the heavy baryonium masses by solving Schr\"{o}dinger equation. We find it is true that the heavy baryonium may exist in a reasonable choice of input parameters. The uncertainties remaining in the potential and their influences on the heavy baryonium mass spectrum are discussed.
[ { "created": "Thu, 17 Feb 2011 03:38:48 GMT", "version": "v1" }, { "created": "Sat, 11 Feb 2012 11:20:23 GMT", "version": "v2" } ]
2013-05-30
[ [ "Chen", "Y. D.", "" ], [ "Qiao", "C. F.", "" ] ]
To see whether heavy baryon and anti-baryon can form a bound state, the heavy baryonium, we study the interaction potential between them in terms of heavy baryon perturbation theory. The obtained potential is applied to calculate the heavy baryonium masses by solving Schr\"{o}dinger equation. We find it is true that the heavy baryonium may exist in a reasonable choice of input parameters. The uncertainties remaining in the potential and their influences on the heavy baryonium mass spectrum are discussed.
0709.2164
Alexander Friedland
Alexander Friedland, Maurizio Giannotti
Extra dimensions, orthopositronium decay, and stellar cooling
13 pages, no figures
null
10.1103/PhysRevLett.100.031602
LA-UR-07-5609
hep-ph astro-ph hep-ex hep-th
null
In a class of extra dimensional models with a warped metric and a single brane the photon can be localized on the brane by gravity only. An intriguing feature of these models is the possibility of the photon escaping into the extra dimensions. The search for this effect has motivated the present round of precision orthopositronium decay experiments. We point out that in this framework a photon in plasma should be metastable. We consider the astrophysical consequences of this observation, in particular, what it implies for the plasmon decay rate in globular cluster stars and for the core-collapse supernova cooling rate. The resulting bounds on the model parameter exceed the possible reach of orthopositronium experiments by many orders of magnitude.
[ { "created": "Fri, 14 Sep 2007 19:57:55 GMT", "version": "v1" } ]
2013-05-29
[ [ "Friedland", "Alexander", "" ], [ "Giannotti", "Maurizio", "" ] ]
In a class of extra dimensional models with a warped metric and a single brane the photon can be localized on the brane by gravity only. An intriguing feature of these models is the possibility of the photon escaping into the extra dimensions. The search for this effect has motivated the present round of precision orthopositronium decay experiments. We point out that in this framework a photon in plasma should be metastable. We consider the astrophysical consequences of this observation, in particular, what it implies for the plasmon decay rate in globular cluster stars and for the core-collapse supernova cooling rate. The resulting bounds on the model parameter exceed the possible reach of orthopositronium experiments by many orders of magnitude.
hep-ph/0107031
Shulyakovsky Roman
V.I.Kuvshinov, V.I.Kashkan, R.G.Shulyakovsky
New Theoretical and Experimental Correlation Aspects of QCD-Instantons in High Energy Collisions
3 page, 3 figures, submitted to International Europhysics Conference on High Energy Physics (July 12-18, 2001, Budapest, Hungary)
null
null
null
hep-ph
null
Possibility of experimental identification of QCD-instantons in high energy collisions is studied by means of correlations analysis in final states. Instanton-induced processes amplitudes are performed in the framework of QCD in Gauss approximation. Hadronization is taken into account by Monte-Carlo method. Obtained results can be used as additional criterions of QCD-instanton identification at HERA (DESY). Unlike previous results in this report we consider also nonzero quarks modes contribution into parton distributions of instanton processes.
[ { "created": "Wed, 4 Jul 2001 08:43:51 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kuvshinov", "V. I.", "" ], [ "Kashkan", "V. I.", "" ], [ "Shulyakovsky", "R. G.", "" ] ]
Possibility of experimental identification of QCD-instantons in high energy collisions is studied by means of correlations analysis in final states. Instanton-induced processes amplitudes are performed in the framework of QCD in Gauss approximation. Hadronization is taken into account by Monte-Carlo method. Obtained results can be used as additional criterions of QCD-instanton identification at HERA (DESY). Unlike previous results in this report we consider also nonzero quarks modes contribution into parton distributions of instanton processes.
1310.7827
Aleksander Kusina
A. Kusina, F. I. Olness, I. Schienbein, T. Jezo, K. Kovarik, T. Stavreva, J. Y. Yu
A $N_F$-Dependent VFNS for Heavy Flavors: Merging the FFNS and VFNS
Presented at the XXI International Workshop on Deep-Inelastic Scattering and Related Subjects, 22-26 April, 2013, Marseilles, France
PoS (DIS 2013) 298
null
SMU-HEP-13-21
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce a Hybrid Variable Flavor Number Scheme (H-VFNS) for heavy flavors, which incorporates the advantages of both the traditional Variable Flavor Number Scheme (VFNS) as well as the Fixed Flavor Number Scheme (FFNS). We include an explicit dependence on number of active flavors $N_F$ in both the Parton Distribution Functions (PDFs) and the strong coupling constant $\alpha_{S}$. This results in sets of coexisting PDFs and $\alpha_{S}$ for $N_F=\{3,4,5,6\}$, that are related analytically by the $\overline{\rm MS}$ matching conditions. The H-VFNS resums the heavy quark contributions and provides the freedom to choose the optimal $N_F$ for each particular data set. Thus, we can fit selected HERA data in a FFNS framework, while retaining the benefits of the VFNS to analyze LHC data at high scales. We illustrate how such a fit can be implemented for the case of both HERA and LHC data.
[ { "created": "Tue, 29 Oct 2013 15:09:26 GMT", "version": "v1" }, { "created": "Thu, 21 Nov 2013 02:25:57 GMT", "version": "v2" } ]
2013-12-13
[ [ "Kusina", "A.", "" ], [ "Olness", "F. I.", "" ], [ "Schienbein", "I.", "" ], [ "Jezo", "T.", "" ], [ "Kovarik", "K.", "" ], [ "Stavreva", "T.", "" ], [ "Yu", "J. Y.", "" ] ]
We introduce a Hybrid Variable Flavor Number Scheme (H-VFNS) for heavy flavors, which incorporates the advantages of both the traditional Variable Flavor Number Scheme (VFNS) as well as the Fixed Flavor Number Scheme (FFNS). We include an explicit dependence on number of active flavors $N_F$ in both the Parton Distribution Functions (PDFs) and the strong coupling constant $\alpha_{S}$. This results in sets of coexisting PDFs and $\alpha_{S}$ for $N_F=\{3,4,5,6\}$, that are related analytically by the $\overline{\rm MS}$ matching conditions. The H-VFNS resums the heavy quark contributions and provides the freedom to choose the optimal $N_F$ for each particular data set. Thus, we can fit selected HERA data in a FFNS framework, while retaining the benefits of the VFNS to analyze LHC data at high scales. We illustrate how such a fit can be implemented for the case of both HERA and LHC data.
2211.09442
Jiang Zhu
Jiang Zhu, Jun Guo, Zhaofeng Kang
Massive Gauge Theory with Quasigluon for Hot $SU(N)$: Phase Transition and Thermodynamics
25 pages, 3 figures
null
10.1103/PhysRevD.107.076005
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
It is challenging to build a model that can correctly and unifiedly account for the deconfinement phase transition and thermodynamics of the hot $SU(N)$ pure Yang-Mills (PYM) system, for any $N$. In this article, we slightly generalize the massive PYM model to the situation with a quasigluon mass $M_g(T)$ varying with temperature, inspired by the quasigluon model. In such a framework, we can acquire an effective potential for the temporal gauge field background by perturbative calculation, rather than adding by hand. The resulting potential works well to describe the behavior of the hot PYM system for all $N$, via the single parameter $M_g(T)$. Moreover, under the assumption of unified eigenvalue distribution, the $M_g(T)$ fitted by machine learning is found to follow $N$-universality.
[ { "created": "Thu, 17 Nov 2022 10:10:55 GMT", "version": "v1" }, { "created": "Tue, 30 Jan 2024 16:50:28 GMT", "version": "v2" } ]
2024-01-31
[ [ "Zhu", "Jiang", "" ], [ "Guo", "Jun", "" ], [ "Kang", "Zhaofeng", "" ] ]
It is challenging to build a model that can correctly and unifiedly account for the deconfinement phase transition and thermodynamics of the hot $SU(N)$ pure Yang-Mills (PYM) system, for any $N$. In this article, we slightly generalize the massive PYM model to the situation with a quasigluon mass $M_g(T)$ varying with temperature, inspired by the quasigluon model. In such a framework, we can acquire an effective potential for the temporal gauge field background by perturbative calculation, rather than adding by hand. The resulting potential works well to describe the behavior of the hot PYM system for all $N$, via the single parameter $M_g(T)$. Moreover, under the assumption of unified eigenvalue distribution, the $M_g(T)$ fitted by machine learning is found to follow $N$-universality.
hep-ph/0101220
Dariusz Prorok
Dariusz Prorok and Ludwik Turko (Wroclaw Univ. ITP)
The sound velocity in an equilibrium hadron gas
LaTeX, 6 figures (included), 6 pages, changes are made in figure captions 1-5
null
null
null
hep-ph
null
We calculate the velocity of sound in an ideal gas of massive hadrons with non-vanishing baryon number. The gas is in thermal and chemical equilibrium. Also we show that the temperature dependence $T(\tau) \cong T_{0} \cdot ({\tau_{0} \over \tau})^{c_{s}^{2}}$ is approximately valid, when the gas expands longitudinally according to the Bjorken law.
[ { "created": "Fri, 19 Jan 2001 15:36:52 GMT", "version": "v1" }, { "created": "Fri, 26 Jan 2001 10:19:31 GMT", "version": "v2" } ]
2007-05-23
[ [ "Prorok", "Dariusz", "", "Wroclaw Univ. ITP" ], [ "Turko", "Ludwik", "", "Wroclaw Univ. ITP" ] ]
We calculate the velocity of sound in an ideal gas of massive hadrons with non-vanishing baryon number. The gas is in thermal and chemical equilibrium. Also we show that the temperature dependence $T(\tau) \cong T_{0} \cdot ({\tau_{0} \over \tau})^{c_{s}^{2}}$ is approximately valid, when the gas expands longitudinally according to the Bjorken law.
hep-ph/9808449
Maxim Polyakov
L.L. Frankfurt, M.V. Polyakov and M. Strikman
N -> Delta DVCS, exclusive DIS processes and skewed quark distributions in large N_c limit
8 pages, latex. Contribution to the Workshop " Jefferson Lab Physics and Instrumentation with 6-12 GeV Beams", Newport News, VA, June 15-18, 1998
null
null
RUB-TPII-12/98
hep-ph
null
We evaluate the amplitude of Bethe-Heitler process: \gamma^* p -> \gamma \Delta^+ -electron bremsstrahlung of photon accompanied by the excitation of \Delta$ isobar. We show that this background is suppressed at small momentum transfer squared t to a proton relative to that for \gamma^* p -> \gamma p and \gamma^* p\to -> \Delta^+ - DVCS processes. From experimental point of view, this means that N -> N and N -> \Delta skewed quark distributions (SQD's) might be measurable at small momentum transfer. Several implications and applications of the QCD factorization theorem for the processes \gamma_{L}^* + p -> h_f +h_s are discussed where h_f - the particle produced along photon momentum $\vec q$ maybe either a meson or a baryon. We discuss also t dependence of DVCS and exclusive meson production as the practical criteria to distinguish between soft and hard regime. Basing on the large-N_c picture of the nucleon as a soliton of the effective chiral Lagrangian we derive relations between N -> N and N ->\Delta SQD's which can be used to estimate amplitude of N -> \Delta DVCS .
[ { "created": "Fri, 28 Aug 1998 09:47:29 GMT", "version": "v1" } ]
2007-05-23
[ [ "Frankfurt", "L. L.", "" ], [ "Polyakov", "M. V.", "" ], [ "Strikman", "M.", "" ] ]
We evaluate the amplitude of Bethe-Heitler process: \gamma^* p -> \gamma \Delta^+ -electron bremsstrahlung of photon accompanied by the excitation of \Delta$ isobar. We show that this background is suppressed at small momentum transfer squared t to a proton relative to that for \gamma^* p -> \gamma p and \gamma^* p\to -> \Delta^+ - DVCS processes. From experimental point of view, this means that N -> N and N -> \Delta skewed quark distributions (SQD's) might be measurable at small momentum transfer. Several implications and applications of the QCD factorization theorem for the processes \gamma_{L}^* + p -> h_f +h_s are discussed where h_f - the particle produced along photon momentum $\vec q$ maybe either a meson or a baryon. We discuss also t dependence of DVCS and exclusive meson production as the practical criteria to distinguish between soft and hard regime. Basing on the large-N_c picture of the nucleon as a soliton of the effective chiral Lagrangian we derive relations between N -> N and N ->\Delta SQD's which can be used to estimate amplitude of N -> \Delta DVCS .
hep-ph/9806449
Nikolai P. Zotov
S.P. Baranov, N.P. Zotov
BFKL gluon dynamics in the $p_T(D^*)$ spectra at HERA
6 pages, latex, 2 figures. Subm. to: 6th International Workshop on DIS and QCD: DIS98, Brussels, Belgium, 4-8 Apr. 1998
null
null
null
hep-ph
null
In the framework of semihard QCD approach, with the emphasis on the BFKL evolution of gluon distributions, we calculate the differential cross sections of inclusive $D^{*\pm}$ mesons electroproduction at HERA and confront our results with available ZEUS experimental data.
[ { "created": "Tue, 23 Jun 1998 09:18:08 GMT", "version": "v1" } ]
2016-09-06
[ [ "Baranov", "S. P.", "" ], [ "Zotov", "N. P.", "" ] ]
In the framework of semihard QCD approach, with the emphasis on the BFKL evolution of gluon distributions, we calculate the differential cross sections of inclusive $D^{*\pm}$ mesons electroproduction at HERA and confront our results with available ZEUS experimental data.
1605.02572
Xing-Gang Wu
Sheng-Quan Wang, Xing-Gang Wu, Stanley J. Brodsky and Matin Mojaza
Application of the Principle of Maximum Conformality to the Hadroproduction of the Higgs Boson at the LHC
13 pages, 7 figures. We thank Michael Peskin for helpful discussions on how to characterize the uncertainty of PMC predictions. Revised version to be published in Phys.Rev.D
Phys. Rev. D 94, 053003 (2016)
10.1103/PhysRevD.94.053003
SLAC-PUB-16521, NORDITA-2016-32
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present improved pQCD predictions for Higgs boson hadroproduction at the Large Hadronic Collider (LHC) by applying the Principle of Maximum Conformality (PMC), a procedure which resums the pQCD series using the renormalization group (RG), thereby eliminating the dependence of the predictions on the choice of the renormalization scheme while minimizing sensitivity to the initial choice of the renormalization scale. In previous pQCD predictions for Higgs boson hadroproduction, it has been conventional to assume that the renormalization scale $\mu_r$ of the QCD coupling $\alpha_s(\mu_r)$ is the Higgs mass, and then to vary this choice over the range $1/2 m_H < \mu_r < 2 m_H $ in order to estimate the theory uncertainty. However, this error estimate is only sensitive to the non-conformal $\beta$ terms in the pQCD series, and thus it fails to correctly estimate the theory uncertainty in cases where pQCD series has large higher order contributions, as is the case for Higgs boson hadroproduction. Furthermore, this \mbox{\it ad hoc} choice of scale and range gives pQCD predictions which depend on the renormalization scheme being used, in contradiction to basic RG principles. In contrast, after applying the PMC, we obtain next-to-next-to-leading order RG resummed pQCD predictions for Higgs boson hadroproduction which are renormalization-scheme independent and have minimal sensitivity to the choice of the initial renormalization scale. Taking $m_H=125$ GeV, the PMC predictions for the $p p \to H X$ Higgs inclusive hadroproduction cross-sections for various LHC center-of-mass energies and the fiducial cross section $\sigma_{\rm fid}(pp\to H\to\gamma\gamma)$ are presented...... The PMC predictions show better agreement with the ATLAS measurements than the LHC-XS predictions which are based on conventional renormalization scale-setting.
[ { "created": "Mon, 9 May 2016 13:08:09 GMT", "version": "v1" }, { "created": "Sun, 28 Aug 2016 02:15:40 GMT", "version": "v2" } ]
2016-09-13
[ [ "Wang", "Sheng-Quan", "" ], [ "Wu", "Xing-Gang", "" ], [ "Brodsky", "Stanley J.", "" ], [ "Mojaza", "Matin", "" ] ]
We present improved pQCD predictions for Higgs boson hadroproduction at the Large Hadronic Collider (LHC) by applying the Principle of Maximum Conformality (PMC), a procedure which resums the pQCD series using the renormalization group (RG), thereby eliminating the dependence of the predictions on the choice of the renormalization scheme while minimizing sensitivity to the initial choice of the renormalization scale. In previous pQCD predictions for Higgs boson hadroproduction, it has been conventional to assume that the renormalization scale $\mu_r$ of the QCD coupling $\alpha_s(\mu_r)$ is the Higgs mass, and then to vary this choice over the range $1/2 m_H < \mu_r < 2 m_H $ in order to estimate the theory uncertainty. However, this error estimate is only sensitive to the non-conformal $\beta$ terms in the pQCD series, and thus it fails to correctly estimate the theory uncertainty in cases where pQCD series has large higher order contributions, as is the case for Higgs boson hadroproduction. Furthermore, this \mbox{\it ad hoc} choice of scale and range gives pQCD predictions which depend on the renormalization scheme being used, in contradiction to basic RG principles. In contrast, after applying the PMC, we obtain next-to-next-to-leading order RG resummed pQCD predictions for Higgs boson hadroproduction which are renormalization-scheme independent and have minimal sensitivity to the choice of the initial renormalization scale. Taking $m_H=125$ GeV, the PMC predictions for the $p p \to H X$ Higgs inclusive hadroproduction cross-sections for various LHC center-of-mass energies and the fiducial cross section $\sigma_{\rm fid}(pp\to H\to\gamma\gamma)$ are presented...... The PMC predictions show better agreement with the ATLAS measurements than the LHC-XS predictions which are based on conventional renormalization scale-setting.
hep-ph/9705313
V. Zoller
V. R. Zoller
Coherent neutrino magnetic conversion in crystals
7 pages Latex, 1 Postscript figure
Phys.Lett. B416 (1998) 447-451
10.1016/S0370-2693(97)01177-5
KFA-IKP(TH)-1997-09
hep-ph
null
We study coherent enhancement of neutrino electro-magnetic conversion in crystals. Large coherency length which grows with the neutrino energy makes the coherent enhancement particularly effective for very small masses. We derive constraints on the conversion rate which follow from the Fresnel effects in scattering of neutrinos on atomic chains. We comment on possible applications of the crystal converter to searches for non-diagonal neutrino magnetic transitions in the CERN neutrino beam.
[ { "created": "Wed, 14 May 1997 17:46:31 GMT", "version": "v1" } ]
2009-10-30
[ [ "Zoller", "V. R.", "" ] ]
We study coherent enhancement of neutrino electro-magnetic conversion in crystals. Large coherency length which grows with the neutrino energy makes the coherent enhancement particularly effective for very small masses. We derive constraints on the conversion rate which follow from the Fresnel effects in scattering of neutrinos on atomic chains. We comment on possible applications of the crystal converter to searches for non-diagonal neutrino magnetic transitions in the CERN neutrino beam.
2102.02542
Hagop Sazdjian
Wolfgang Lucha, Dmitri Melikhov, Hagop Sazdjian
Tetraquarks in large-$N_c$ QCD
132 pages, 53 figures. Review article. v2: Sections 2.7 and 5.4 have been slightly extended; a few clarifying comments have been added in other sections; figure 43 has been completed; references have been added
Prog. Part. Nucl. Phys. 120 (2021) 103867
10.1016/j.ppnp.2021.103867
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The present work reviews the various aspects of the extension of the large-$N_c$ approach, as had been proposed and developed by 't Hooft, to the case of tetraquark states, which are a category of the general class of exotic states, also called multiquark states, whose internal valence-quark structure does not match with that of ordinary hadrons, and which have received, in recent years, many experimental confirmations. The primary question of describing, or probing, on theoretical grounds, multiquark states is first examined. The signature of such states inside Feynman diagrams in relation with their singularities is highlighted. The main mechanisms of formation of tetraquark states, provided by the diquark model and the molecular scheme, are considered together with their specific implications. The properties of tetraquark states at large $N_c$ are analyzed through the Feynman diagrams that describe two-meson scattering amplitudes. It turns out that, in that limit, the possible formation of tetraquark states is mainly due to the mutual interactions of their internal mesonic clusters. These essentially arise from the quark-rearrangement, or quark-interchange, mechanism. In coupled-channel meson-meson scattering amplitudes, one may expect the occurrence of two independent tetraquark states, each having priviledged couplings with the two mesons of their dominant channel. The question of the energy balance of various schemes in the static limit is also analyzed. The clarification of the mechanisms that are at work in the formation of tetraquarks is the main outcome from the large-$N_c$ approach to this problem.
[ { "created": "Thu, 4 Feb 2021 11:02:06 GMT", "version": "v1" }, { "created": "Tue, 27 Apr 2021 10:59:03 GMT", "version": "v2" } ]
2021-07-12
[ [ "Lucha", "Wolfgang", "" ], [ "Melikhov", "Dmitri", "" ], [ "Sazdjian", "Hagop", "" ] ]
The present work reviews the various aspects of the extension of the large-$N_c$ approach, as had been proposed and developed by 't Hooft, to the case of tetraquark states, which are a category of the general class of exotic states, also called multiquark states, whose internal valence-quark structure does not match with that of ordinary hadrons, and which have received, in recent years, many experimental confirmations. The primary question of describing, or probing, on theoretical grounds, multiquark states is first examined. The signature of such states inside Feynman diagrams in relation with their singularities is highlighted. The main mechanisms of formation of tetraquark states, provided by the diquark model and the molecular scheme, are considered together with their specific implications. The properties of tetraquark states at large $N_c$ are analyzed through the Feynman diagrams that describe two-meson scattering amplitudes. It turns out that, in that limit, the possible formation of tetraquark states is mainly due to the mutual interactions of their internal mesonic clusters. These essentially arise from the quark-rearrangement, or quark-interchange, mechanism. In coupled-channel meson-meson scattering amplitudes, one may expect the occurrence of two independent tetraquark states, each having priviledged couplings with the two mesons of their dominant channel. The question of the energy balance of various schemes in the static limit is also analyzed. The clarification of the mechanisms that are at work in the formation of tetraquarks is the main outcome from the large-$N_c$ approach to this problem.
hep-ph/0404077
Javier Ferrandis
Javier Ferrandis (Hawaii U.) and Naoyuki Haba (Tokushima U.)
Supersymmetry breaking as the origin of flavor
14 pages, RevTex 4
Phys.Rev. D70 (2004) 055003
10.1103/PhysRevD.70.055003
UH-511-1047-04
hep-ph
null
We present an effective flavor model for the radiative generation of fermion masses and mixings based on a SU(5)xU(2) symmetry. We assume that the original source of flavor breaking resides in the supersymmetry breaking sector. Flavor violation is transmitted radiatively to the fermion Yukawa couplings at low energy through finite supersymmetric threshold corrections. This model can fit the fermion mass ratios and CKM matrix elements, explain the non-observation of proton decay, and overcome present constraints on flavor changing processes through an approximate radiative alignment between the Yukawa and the soft trilinear sector. The model predicts new relations between dimensionless fermion mass ratios in the three fermion sectors, and the quark mixing angles.
[ { "created": "Thu, 8 Apr 2004 19:09:25 GMT", "version": "v1" }, { "created": "Sat, 10 Apr 2004 02:12:35 GMT", "version": "v2" }, { "created": "Fri, 16 Apr 2004 20:44:00 GMT", "version": "v3" }, { "created": "Sat, 15 May 2004 21:45:47 GMT", "version": "v4" } ]
2009-11-10
[ [ "Ferrandis", "Javier", "", "Hawaii U." ], [ "Haba", "Naoyuki", "", "Tokushima U." ] ]
We present an effective flavor model for the radiative generation of fermion masses and mixings based on a SU(5)xU(2) symmetry. We assume that the original source of flavor breaking resides in the supersymmetry breaking sector. Flavor violation is transmitted radiatively to the fermion Yukawa couplings at low energy through finite supersymmetric threshold corrections. This model can fit the fermion mass ratios and CKM matrix elements, explain the non-observation of proton decay, and overcome present constraints on flavor changing processes through an approximate radiative alignment between the Yukawa and the soft trilinear sector. The model predicts new relations between dimensionless fermion mass ratios in the three fermion sectors, and the quark mixing angles.
hep-ph/0411340
Hai-Yang Cheng
Hai-Yang Cheng
Direct CP Violation and Final State Interactions in Hadronic B Decays
7 pages, talk presented at Flavor Physics and CP Violation, Oct 4-9, 2004, Daegu, Korea
null
null
null
hep-ph hep-ex
null
Final-state rescattering effects on the hadronic B decays and their impact on direct CP violation are examined. The phenomenology of the polarization anomaly in $B\to\phi K^*$ decays is discussed.
[ { "created": "Fri, 26 Nov 2004 01:33:02 GMT", "version": "v1" } ]
2007-05-23
[ [ "Cheng", "Hai-Yang", "" ] ]
Final-state rescattering effects on the hadronic B decays and their impact on direct CP violation are examined. The phenomenology of the polarization anomaly in $B\to\phi K^*$ decays is discussed.
hep-ph/9309237
null
M.B. Voloshin
Catalyzed decay of false vacuum in four dimensions
9 pages (standard LaTeX)+ 3 figures (one figure in LaTeX, two are appended in PostScript). TPI-MINN-92/31-T
null
10.1103/PhysRevD.49.2014
null
hep-ph
null
The probability of destruction of a metastable vacuum state by the field of a highly virtual particle with energy $E$ is calculated for a (3+1) dimensional theory in the leading WKB approximation in the thin-wall limit. It is found that the induced nucleation rate of bubbles, capable of expansion, is exponentially small at any energy. The negative exponential power in the rate reaches its maximum at the energy, corresponding to the top of the barrier in the bubble energy, where it is a finite fraction of the same power in the probability of the spontaneous decay of the false vacuum, i.e. at $E=0$.
[ { "created": "Tue, 7 Sep 1993 18:05:26 GMT", "version": "v1" } ]
2009-10-22
[ [ "Voloshin", "M. B.", "" ] ]
The probability of destruction of a metastable vacuum state by the field of a highly virtual particle with energy $E$ is calculated for a (3+1) dimensional theory in the leading WKB approximation in the thin-wall limit. It is found that the induced nucleation rate of bubbles, capable of expansion, is exponentially small at any energy. The negative exponential power in the rate reaches its maximum at the energy, corresponding to the top of the barrier in the bubble energy, where it is a finite fraction of the same power in the probability of the spontaneous decay of the false vacuum, i.e. at $E=0$.
0710.4439
Christian Sander
Christian Sander
Supersymmetric Interpretation of the EGRET Excess in Diffuse Galactic Gamma Rays
Submitted for the SUSY07 proceedings, 4 pages, LaTEX, 4 eps figures
null
null
null
hep-ph
null
Recently it was shown that the excess of diffuse Galactic gamma rays above 1 GeV could be interpreted as a Dark Matter annihilation signal. From the spectral shape of the excess it is possible to determine a range for the allowed WIMP mass which can be used to test the supersymmetric parameter space. It is found that the EGRET excess combined with electroweak and other constraints, e.g. relic denisity or direct detection limits, is fully consistent with the minimal mSUGRA model for scalars in the TeV range and gauginos below 500 GeV.
[ { "created": "Wed, 24 Oct 2007 11:53:28 GMT", "version": "v1" } ]
2007-10-25
[ [ "Sander", "Christian", "" ] ]
Recently it was shown that the excess of diffuse Galactic gamma rays above 1 GeV could be interpreted as a Dark Matter annihilation signal. From the spectral shape of the excess it is possible to determine a range for the allowed WIMP mass which can be used to test the supersymmetric parameter space. It is found that the EGRET excess combined with electroweak and other constraints, e.g. relic denisity or direct detection limits, is fully consistent with the minimal mSUGRA model for scalars in the TeV range and gauginos below 500 GeV.
0904.4913
Harry Lipkin J
Harry J. Lipkin
Difficulties in using the sharp neutrino spectrum at short times
3 pages
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Final states produced by a decay have a much broader energy spectrum than the natural line width at times much shorter than the decay lifetime. This tends to render impossible the use for neutrino detection of the high value of the resonance absorption cross section at the peak of the resonance.
[ { "created": "Thu, 30 Apr 2009 18:35:42 GMT", "version": "v1" } ]
2009-05-01
[ [ "Lipkin", "Harry J.", "" ] ]
Final states produced by a decay have a much broader energy spectrum than the natural line width at times much shorter than the decay lifetime. This tends to render impossible the use for neutrino detection of the high value of the resonance absorption cross section at the peak of the resonance.
hep-ph/9912224
null
A. Dobado, M. J. Herrero, J. R. Pelaez and E. Ruiz Morales
LHC sensitivity to the resonance spectrum of a minimal strongly interacting electroweak symmetry breaking sector
Final version to appear in Phys. Rev. D, including a more detailed exposition and a few more references. Conclusions and results unchanged. 14 pages, 5 figures
Phys.Rev.D62:055011,2000
10.1103/PhysRevD.62.055011
FTUAM 99/31
hep-ph
null
We present a unified analysis of the two main production processes of vector boson pairs at the LHC, VV-fusion and qqbar annihilation, in a minimal strongly interacting electroweak symmetry breaking sector. Using a unitarized electroweak chiral Lagrangian formalism and modeling the final V_L V_L strong rescattering effects by a form factor, we describe qqbar annihilation processes in terms of the two chiral parameters that govern elastic V_L V_L scattering. Depending on the values of these two chiral parameters, the unitarized amplitudes may present resonant enhancements in different angular momentum-isospin channels. Scanning this two parameter space, we generate the general resonance spectrum of a minimal strongly interacting electroweak symmetry breaking sector and determine the regions that can be probed at the LHC.
[ { "created": "Thu, 2 Dec 1999 19:38:09 GMT", "version": "v1" }, { "created": "Fri, 3 Dec 1999 17:50:11 GMT", "version": "v2" }, { "created": "Sat, 10 Jun 2000 11:53:38 GMT", "version": "v3" } ]
2008-11-26
[ [ "Dobado", "A.", "" ], [ "Herrero", "M. J.", "" ], [ "Pelaez", "J. R.", "" ], [ "Morales", "E. Ruiz", "" ] ]
We present a unified analysis of the two main production processes of vector boson pairs at the LHC, VV-fusion and qqbar annihilation, in a minimal strongly interacting electroweak symmetry breaking sector. Using a unitarized electroweak chiral Lagrangian formalism and modeling the final V_L V_L strong rescattering effects by a form factor, we describe qqbar annihilation processes in terms of the two chiral parameters that govern elastic V_L V_L scattering. Depending on the values of these two chiral parameters, the unitarized amplitudes may present resonant enhancements in different angular momentum-isospin channels. Scanning this two parameter space, we generate the general resonance spectrum of a minimal strongly interacting electroweak symmetry breaking sector and determine the regions that can be probed at the LHC.
1109.2829
Germano Nardini
Germano Nardini and Narendra Sahu
Re-reheating, late entropy injection and constraints from baryogenesis scenarios
Revtex4-1, 11 pages, 6 figures
null
null
ULB-TH/10-18
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Many theories of particle physics beyond the Standard Model predict long-lived fields that may have dominated the Universe at early times and then decayed. Their decay, which injects entropy in the thermal bath, is responsible for a second reheating, dubbed re-reheating, that could substantially dilute the matter-antimatter asymmetry created before. In this paper we analyze such late re-reheating and entropy dilution. It turns out that in some cases the usual analytic calculation badly fails if it is not rectified by some corrective factors that we provide. We also determine the parameter space where the entropy dilution compromises models of baryogenesis. This region can be obtained by imposing some generic constraints that are applicable to any baryogenesis mechanism and long-lived field satisfying a few assumptions. For instance, by applying them to MSSM electroweak baryogenesis, thermal non-resonant leptogenesis and thermal resonant leptogenesis, we obtain that the initial abundances of long-lived fields with lifetime longer than respectively 5*10^13, 10^-2 and 10^15 GeV^-1 are strongly constrained. Similarly, the same baryogenesis scenarios are incompatible with large oscillations of moduli with mass smaller than O(10^8), O(10^13) and O(10^7) GeV that are naturally coupled to the visible sector via gravitational dimension-five operators.
[ { "created": "Tue, 13 Sep 2011 15:36:54 GMT", "version": "v1" } ]
2011-09-14
[ [ "Nardini", "Germano", "" ], [ "Sahu", "Narendra", "" ] ]
Many theories of particle physics beyond the Standard Model predict long-lived fields that may have dominated the Universe at early times and then decayed. Their decay, which injects entropy in the thermal bath, is responsible for a second reheating, dubbed re-reheating, that could substantially dilute the matter-antimatter asymmetry created before. In this paper we analyze such late re-reheating and entropy dilution. It turns out that in some cases the usual analytic calculation badly fails if it is not rectified by some corrective factors that we provide. We also determine the parameter space where the entropy dilution compromises models of baryogenesis. This region can be obtained by imposing some generic constraints that are applicable to any baryogenesis mechanism and long-lived field satisfying a few assumptions. For instance, by applying them to MSSM electroweak baryogenesis, thermal non-resonant leptogenesis and thermal resonant leptogenesis, we obtain that the initial abundances of long-lived fields with lifetime longer than respectively 5*10^13, 10^-2 and 10^15 GeV^-1 are strongly constrained. Similarly, the same baryogenesis scenarios are incompatible with large oscillations of moduli with mass smaller than O(10^8), O(10^13) and O(10^7) GeV that are naturally coupled to the visible sector via gravitational dimension-five operators.
1910.03035
H\`ector Bello Martinez
H. Bello Mart\'inez, R. J. Hern\'andez-Pinto, I. Le\'on Monz\'on
Spherocity study for e^{+}e^{-} Fragmentation Functions using Pythia MC generator
8 pages, 5 figures, conference proceedings from LHCP2019
PoS(LHCP2019)050
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Fragmentation Functions is one of the non-perturbative components of the QCD factorization theorem. They represents the probability of a parton carrying a fraction z of momentum to form into a particular kind of hadron. In this work, we study the jet fragmentation functions in the collisions between electrons and positrons. The jets where identified with Fastjet for different p_{Tch jet} intervals. The intervals and the final jets were reconstructed by means of the event shape T separation using spherocity variable, the study is performed under Pythia Monte Carlo event generator framework.
[ { "created": "Mon, 7 Oct 2019 19:14:04 GMT", "version": "v1" } ]
2019-10-09
[ [ "Martínez", "H. Bello", "" ], [ "Hernández-Pinto", "R. J.", "" ], [ "Monzón", "I. León", "" ] ]
The Fragmentation Functions is one of the non-perturbative components of the QCD factorization theorem. They represents the probability of a parton carrying a fraction z of momentum to form into a particular kind of hadron. In this work, we study the jet fragmentation functions in the collisions between electrons and positrons. The jets where identified with Fastjet for different p_{Tch jet} intervals. The intervals and the final jets were reconstructed by means of the event shape T separation using spherocity variable, the study is performed under Pythia Monte Carlo event generator framework.
2207.01703
Yingsheng Huang
Radja Boughezal, Yingsheng Huang, Frank Petriello
Exploring the SMEFT at dimension-8 with Drell-Yan transverse momentum measurements
23 pages, 7 figures, 7 tables
null
10.1103/PhysRevD.106.036020
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We demonstrate that measurements of the neutral-current Drell-Yan transverse momentum distribution binned in invariant mass are sensitive to unexplored dimension-8 parameters of the Standard Model Effective Field Theory (SMEFT). These distributions are sensitive to four-fermion operators with additional QCD field strength tensors. The determination of the Wilson coefficients of these operators provides a useful diagnostic tool that distinguishes possible ultraviolet completions of the SMEFT. We study how well these effects can be probed by current LHC data, and explore the sensitivity of the future high-luminosity LHC (HL-LHC) to these operators. We find that the HL-LHC data has the potential to strongly probe this sector of the SMEFT.
[ { "created": "Mon, 4 Jul 2022 20:02:27 GMT", "version": "v1" } ]
2022-09-14
[ [ "Boughezal", "Radja", "" ], [ "Huang", "Yingsheng", "" ], [ "Petriello", "Frank", "" ] ]
We demonstrate that measurements of the neutral-current Drell-Yan transverse momentum distribution binned in invariant mass are sensitive to unexplored dimension-8 parameters of the Standard Model Effective Field Theory (SMEFT). These distributions are sensitive to four-fermion operators with additional QCD field strength tensors. The determination of the Wilson coefficients of these operators provides a useful diagnostic tool that distinguishes possible ultraviolet completions of the SMEFT. We study how well these effects can be probed by current LHC data, and explore the sensitivity of the future high-luminosity LHC (HL-LHC) to these operators. We find that the HL-LHC data has the potential to strongly probe this sector of the SMEFT.
0806.3989
Frank J. Petriello
Frank Petriello, Kathryn M. Zurek
DAMA and WIMP dark matter
19 pages, 10 figures. References and discussion added
JHEP 0809:047,2008
10.1088/1126-6708/2008/09/047
null
hep-ph astro-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study whether spin-independent scattering of weakly-interacting massive particles (WIMPs) with nuclei can account for the annual modulation signal reported by DAMA. We consider both elastic and inelastic scattering processes. We find that there is a region of WIMP parameter space which can simultaneously accommodate DAMA and the null results of CDMS, CRESST, and XENON. This region corresponds to an ordinary, elastically-scattering WIMP with a standard Maxwell-Boltzmann distribution, a mass 3 GeV < m_{DM} <8 GeV, and a spin-independent cross section with nucleons 3 \times 10^{-41} cm^2 < \sigma_p^{SI} < 5 \times 10^{-39} cm^2. This new region of parameter space depends crucially on the recently discovered effect of channeling on the energy threshold for WIMP detection in the DAMA experiment; without the inclusion of this effect, the DAMA allowed region is essentially closed by null experiments. Such low-mass WIMPs arise in many theories of Beyond the Standard Model physics, from minimal extensions of the MSSM to solutions of the baryon-dark matter coincidence problem. We find that inelastic scattering channels do not open up a significant parameter region consistent with all experimental results. Future experiments with low energy thresholds for detecting nuclear recoils, such as CDMSII-Si and those utilizing ultra-low energy germanium detectors, will be able to probe the DAMA region of parameter space.
[ { "created": "Wed, 25 Jun 2008 19:47:44 GMT", "version": "v1" }, { "created": "Wed, 9 Jul 2008 16:05:59 GMT", "version": "v2" }, { "created": "Fri, 11 Jul 2008 21:15:51 GMT", "version": "v3" } ]
2009-05-29
[ [ "Petriello", "Frank", "" ], [ "Zurek", "Kathryn M.", "" ] ]
We study whether spin-independent scattering of weakly-interacting massive particles (WIMPs) with nuclei can account for the annual modulation signal reported by DAMA. We consider both elastic and inelastic scattering processes. We find that there is a region of WIMP parameter space which can simultaneously accommodate DAMA and the null results of CDMS, CRESST, and XENON. This region corresponds to an ordinary, elastically-scattering WIMP with a standard Maxwell-Boltzmann distribution, a mass 3 GeV < m_{DM} <8 GeV, and a spin-independent cross section with nucleons 3 \times 10^{-41} cm^2 < \sigma_p^{SI} < 5 \times 10^{-39} cm^2. This new region of parameter space depends crucially on the recently discovered effect of channeling on the energy threshold for WIMP detection in the DAMA experiment; without the inclusion of this effect, the DAMA allowed region is essentially closed by null experiments. Such low-mass WIMPs arise in many theories of Beyond the Standard Model physics, from minimal extensions of the MSSM to solutions of the baryon-dark matter coincidence problem. We find that inelastic scattering channels do not open up a significant parameter region consistent with all experimental results. Future experiments with low energy thresholds for detecting nuclear recoils, such as CDMSII-Si and those utilizing ultra-low energy germanium detectors, will be able to probe the DAMA region of parameter space.
1301.7645
Chihiro Sasaki
Chihiro Sasaki, Krzysztof Redlich
Effective gluon potential and Yang-Mills thermodynamics
6 pages, to appear in the proceedings of the Xth Quark Confinement and the Hadron Spectrum, October 8-12, 2012, TUM Campus Garching, Munich, Germany
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive the Polyakov-loop thermodynamic potential in the perturbative approach to pure SU(3) Yang-Mills theory. The potential expressed in terms of the Polyakov loop in the fundamental representation corresponds to that of the strong-coupling expansion, of which the relevant coefficients of the gluon energy distribution are specified by characters of the SU(3) group. At high temperature, the potential exhibits the correct asymptotic behavior, whereas at low temperature, it disfavors gluons as appropriate dynamical degrees of freedom. To quantify the Yang-Mills thermodynamics in confined phase, we introduce a hybrid approach which matches the effective gluon potential to that of glueballs, constrained by the QCD trace anomaly in terms of dilaton fields.
[ { "created": "Thu, 31 Jan 2013 15:29:23 GMT", "version": "v1" } ]
2013-02-01
[ [ "Sasaki", "Chihiro", "" ], [ "Redlich", "Krzysztof", "" ] ]
We derive the Polyakov-loop thermodynamic potential in the perturbative approach to pure SU(3) Yang-Mills theory. The potential expressed in terms of the Polyakov loop in the fundamental representation corresponds to that of the strong-coupling expansion, of which the relevant coefficients of the gluon energy distribution are specified by characters of the SU(3) group. At high temperature, the potential exhibits the correct asymptotic behavior, whereas at low temperature, it disfavors gluons as appropriate dynamical degrees of freedom. To quantify the Yang-Mills thermodynamics in confined phase, we introduce a hybrid approach which matches the effective gluon potential to that of glueballs, constrained by the QCD trace anomaly in terms of dilaton fields.
2108.12345
Anton Rebhan
Josef Leutgeb, Anton Rebhan
Hadronic light-by-light contribution to the muon $g-2$ from holographic QCD with massive pions
28 pages, 10 figures, 4 tables; v2: table IV expanded, reference added
null
10.1103/PhysRevD.104.094017
null
hep-ph hep-th
http://creativecommons.org/licenses/by-nc-nd/4.0/
We extend our previous calculations of the hadronic light-by-light scattering contribution to the muon anomalous magnetic moment in holographic QCD to models with finite quark masses and a tower of massive pions. Analysing the role of the latter in the Wess-Zumino-Witten action, we show that the Melnikov-Vainshtein short-distance constraint is satisfied solely by the summation of contributions from the infinite tower of axial vector meson contributions. There is also an enhancement of the asymptotic behavior of pseudoscalar contributions when their infinite tower of excitations is summed, but this leads only to subleading contributions for the short-distance constraints on light-by-light scattering. We also refine our numerical evaluations, particularly in the pion and $a_1$ sector, which corroborates our previous findings of contributions from axial vector mesons that are significantly larger than those adopted for the effects of axials and short-distance constraints in the recent White Paper on the Standard Model prediction for $(g-2)_\mu$.
[ { "created": "Fri, 27 Aug 2021 15:20:40 GMT", "version": "v1" }, { "created": "Mon, 6 Sep 2021 16:54:56 GMT", "version": "v2" } ]
2021-11-24
[ [ "Leutgeb", "Josef", "" ], [ "Rebhan", "Anton", "" ] ]
We extend our previous calculations of the hadronic light-by-light scattering contribution to the muon anomalous magnetic moment in holographic QCD to models with finite quark masses and a tower of massive pions. Analysing the role of the latter in the Wess-Zumino-Witten action, we show that the Melnikov-Vainshtein short-distance constraint is satisfied solely by the summation of contributions from the infinite tower of axial vector meson contributions. There is also an enhancement of the asymptotic behavior of pseudoscalar contributions when their infinite tower of excitations is summed, but this leads only to subleading contributions for the short-distance constraints on light-by-light scattering. We also refine our numerical evaluations, particularly in the pion and $a_1$ sector, which corroborates our previous findings of contributions from axial vector mesons that are significantly larger than those adopted for the effects of axials and short-distance constraints in the recent White Paper on the Standard Model prediction for $(g-2)_\mu$.
hep-ph/0603228
Andrew Psallidas
T. Dent, G.K. Leontaris, A. Psallidas, J. Rizos
Renormalization effects on neutrino masses and mixing in a string-inspired SU(4) X SU(2)_L X SU(2)_R X U(1)_X model
9 pages, 7 figures; references added
Phys.Rev.D75:065027,2007
10.1103/PhysRevD.75.065027
null
hep-ph hep-th
null
We discuss renormalization effects on neutrino masses and mixing angles in a supersymmetric string-inspired SU(4) X SU(2)_L X SU(2)_R X U(1)_X model, with matter in fundamental and antisymmetric tensor representations and singlet Higgs fields charged under the anomalous U(1)_X family symmetry. The quark, lepton and neutrino Yukawa matrices are distinguished by different Clebsch-Gordan coefficients. The presence of a second U(1)_X breaking singlet with fractional charge allows a more realistic, hierarchical light neutrino mass spectrum with bi-large mixing. By numerical investigation we find a region in the model parameter space where the neutrino mass-squared differences and mixing angles at low energy are consistent with experimental data.
[ { "created": "Tue, 28 Mar 2006 16:50:24 GMT", "version": "v1" }, { "created": "Mon, 3 Apr 2006 19:49:37 GMT", "version": "v2" } ]
2008-11-26
[ [ "Dent", "T.", "" ], [ "Leontaris", "G. K.", "" ], [ "Psallidas", "A.", "" ], [ "Rizos", "J.", "" ] ]
We discuss renormalization effects on neutrino masses and mixing angles in a supersymmetric string-inspired SU(4) X SU(2)_L X SU(2)_R X U(1)_X model, with matter in fundamental and antisymmetric tensor representations and singlet Higgs fields charged under the anomalous U(1)_X family symmetry. The quark, lepton and neutrino Yukawa matrices are distinguished by different Clebsch-Gordan coefficients. The presence of a second U(1)_X breaking singlet with fractional charge allows a more realistic, hierarchical light neutrino mass spectrum with bi-large mixing. By numerical investigation we find a region in the model parameter space where the neutrino mass-squared differences and mixing angles at low energy are consistent with experimental data.
hep-ph/0604151
Adrian Melissinos
Adrian C. Melissinos (Department of Physics and Astronomy) (University of Rochester, Rochester NY)
Search for Higher Dimensions through their Gravitational Effects in High Energy Collisions
null
null
null
null
hep-ph
null
We consider the use of a microwave parametric converter for the direct detection of gravitational effects at the LHC. Because of the extra dimensions the strength of the gravitational interaction in the bulk grows at high energies. This leads to possibly detectable signals.
[ { "created": "Tue, 18 Apr 2006 14:29:10 GMT", "version": "v1" } ]
2007-05-23
[ [ "Melissinos", "Adrian C.", "", "Department of Physics and Astronomy" ] ]
We consider the use of a microwave parametric converter for the direct detection of gravitational effects at the LHC. Because of the extra dimensions the strength of the gravitational interaction in the bulk grows at high energies. This leads to possibly detectable signals.
1605.05295
Avdhesh Kumar
Avdhesh Kumar, Jitesh R. Bhatt, Amita Das and P. K. Kaw
Shear Viscosity of Turbulent Chiral Plasma
8 pages, 1 figure
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is well known that the difference between the chemical potentials of left-handed and right-handed particles in a parity violating (chiral) plasma can lead to an instability. We show that the chiral instability may drive turbulent transport. Further we estimate the anomalous viscosity of chiral plasma arising from the enhanced collisionality due to turbulence.
[ { "created": "Tue, 17 May 2016 19:25:10 GMT", "version": "v1" } ]
2016-05-18
[ [ "Kumar", "Avdhesh", "" ], [ "Bhatt", "Jitesh R.", "" ], [ "Das", "Amita", "" ], [ "Kaw", "P. K.", "" ] ]
It is well known that the difference between the chemical potentials of left-handed and right-handed particles in a parity violating (chiral) plasma can lead to an instability. We show that the chiral instability may drive turbulent transport. Further we estimate the anomalous viscosity of chiral plasma arising from the enhanced collisionality due to turbulence.
1105.5511
T. Lappi
T. Lappi
Gluon spectrum in the glasma from JIMWLK evolution
7 pages, 8 figures, RevTeX. V2: typo corrections, corrected fig 1. Published in PLB
Phys.Lett.B703:325-330,2011
10.1016/j.physletb.2011.08.011
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The JIMWLK equation with a "daughter dipole" running coupling is solved numerically starting from an initial condition given by the McLerran-Venugopalan model. The resulting Wilson line configurations are then used to compute the spectrum of gluons comprising the glasma inital state of a high energy heavy ion collision. The development of a geometrical scaling region makes the spectrum of produced gluons harder. Thus the ratio of the mean gluon transverse momentum to the saturation scale grows with energy. Also the total gluon multiplicity increases with energy slightly faster than the saturation scale squared.
[ { "created": "Fri, 27 May 2011 09:50:57 GMT", "version": "v1" }, { "created": "Wed, 24 Aug 2011 07:10:58 GMT", "version": "v2" } ]
2011-09-09
[ [ "Lappi", "T.", "" ] ]
The JIMWLK equation with a "daughter dipole" running coupling is solved numerically starting from an initial condition given by the McLerran-Venugopalan model. The resulting Wilson line configurations are then used to compute the spectrum of gluons comprising the glasma inital state of a high energy heavy ion collision. The development of a geometrical scaling region makes the spectrum of produced gluons harder. Thus the ratio of the mean gluon transverse momentum to the saturation scale grows with energy. Also the total gluon multiplicity increases with energy slightly faster than the saturation scale squared.
hep-ph/9606414
null
Csaba Csaki (MIT)
The Minimal Supersymmetric Standard Model (MSSM)
Brief review, 15 pages, LaTeX, 2 embedded figures
Mod.Phys.Lett.A11:599,1996
10.1142/S021773239600062X
MIT-CTP-2542
hep-ph
null
The structure of the MSSM is reviewed. We first motivate the particle content of the theory by examining the quantum numbers of the known standard model particles and by the requirement of anomaly cancellation. Once the particle content is fixed we can write down the most general renormalizable superpotential. However such a superpotential will contain terms breaking lepton and baryon number which leads us to the concept of R-parity conservation. The question of supersymmetry breaking is discussed next. We list the possible soft breaking terms. However the Lagrangian involving the most general soft breaking terms is phenomenologically intractable because of the appearance of the many new parameters. It also leads to some unacceptable predictions. To reduce the number of parameters we restrict ourself to the case with universal soft breaking terms at the GUT scale. We motivate the need for universal soft breaking terms by the apparent unification of gauge couplings in the MSSM and by the absence of flavor changing neutral currents. Then we discuss radiative electroweak symmetry breaking. Radiative breaking arises because the one loop corrections involving the large top Yukawa coupling change the sign of the soft breaking mass parameter of the up-type Higgs doublet, this way introducing a nontrivial minimum in the Higgs potential. Finally we give an overview of the possible mixings in the MSSM and enumerate the physical (mass eigenstate) fields together with the mass matrices.
[ { "created": "Sat, 22 Jun 1996 17:21:12 GMT", "version": "v1" } ]
2009-09-17
[ [ "Csaki", "Csaba", "", "MIT" ] ]
The structure of the MSSM is reviewed. We first motivate the particle content of the theory by examining the quantum numbers of the known standard model particles and by the requirement of anomaly cancellation. Once the particle content is fixed we can write down the most general renormalizable superpotential. However such a superpotential will contain terms breaking lepton and baryon number which leads us to the concept of R-parity conservation. The question of supersymmetry breaking is discussed next. We list the possible soft breaking terms. However the Lagrangian involving the most general soft breaking terms is phenomenologically intractable because of the appearance of the many new parameters. It also leads to some unacceptable predictions. To reduce the number of parameters we restrict ourself to the case with universal soft breaking terms at the GUT scale. We motivate the need for universal soft breaking terms by the apparent unification of gauge couplings in the MSSM and by the absence of flavor changing neutral currents. Then we discuss radiative electroweak symmetry breaking. Radiative breaking arises because the one loop corrections involving the large top Yukawa coupling change the sign of the soft breaking mass parameter of the up-type Higgs doublet, this way introducing a nontrivial minimum in the Higgs potential. Finally we give an overview of the possible mixings in the MSSM and enumerate the physical (mass eigenstate) fields together with the mass matrices.
2110.05489
Ariel Zhitnitsky
Ariel Zhitnitsky
The mysterious diffuse UV radiation and Axion Quark Nugget dark matter model
Final version to appear in Phys. Lett. B
Phys. Lett. B 828 (2022) 137015
10.1016/j.physletb.2022.137015
null
hep-ph astro-ph.GA
http://creativecommons.org/licenses/by/4.0/
It has been recently argued [1-3] that there is a strong component of the diffuse far-ultraviolet (FUV) background which is hard to explain by conventional physics in terms of the dust-scattered starlight. We propose that this excess in FUV radiation might be result of the dark matter annihilation events within the so-called axion quark nugget (AQN) dark matter model, which was originally invented for completely different purpose to explain the observed similarity between the dark and the visible components in the Universe, i.e. $\Omega_{\rm DM}\sim \Omega_{\rm visible}$. We support this proposal by demonstrating that intensity and the spectral features of the AQN induced emissions are consistent with the corresponding characteristics of the observed excess of the FUV radiation. If the future studies confirm the puzzling characteristics observed in [1-3] it might unlock a much more deeper and fundamental problem of modern cosmology-- it may reveal the nature of the dark matter.
[ { "created": "Mon, 11 Oct 2021 18:00:00 GMT", "version": "v1" }, { "created": "Tue, 8 Mar 2022 17:54:03 GMT", "version": "v2" } ]
2022-03-17
[ [ "Zhitnitsky", "Ariel", "" ] ]
It has been recently argued [1-3] that there is a strong component of the diffuse far-ultraviolet (FUV) background which is hard to explain by conventional physics in terms of the dust-scattered starlight. We propose that this excess in FUV radiation might be result of the dark matter annihilation events within the so-called axion quark nugget (AQN) dark matter model, which was originally invented for completely different purpose to explain the observed similarity between the dark and the visible components in the Universe, i.e. $\Omega_{\rm DM}\sim \Omega_{\rm visible}$. We support this proposal by demonstrating that intensity and the spectral features of the AQN induced emissions are consistent with the corresponding characteristics of the observed excess of the FUV radiation. If the future studies confirm the puzzling characteristics observed in [1-3] it might unlock a much more deeper and fundamental problem of modern cosmology-- it may reveal the nature of the dark matter.
0907.3897
Sean Fleming
Sean Fleming
Soft Collinear Effective Theory: An Overview
Presented at the International Workshop on Effective Field Theories: from the pion to the upsilon, February 2-6 2009, Valencia, Spain
PoS EFT09:002,2009
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this talk I give an overview of soft collinear effective theory (SCET), including a discussion of some recent advances. First, I briefly cover the foundation upon which SCET is built, namely QCD factorization, and review the theoretical framework of SCET. Next, I cover some recent calculations involving SCET. Since there are more interesting results than I can cover, I have picked four that that I find particularly exciting. The first two topics are dynamical threshold enhancements in Drell-Yan and resummation of higgs production at the LHC. Both topics center on the resummation of large Sudakov logarithms, however, for each there is a twist. In the case of threshold enhancements in Drell-Yan, it is partonic, not hadronic logarithms that are summed. In the case of higgs production at the LHC, the twist is that the logarithms are of a time-like scale. The third topic highlighted is electroweak corrections at high energy. In particular the electroweak Sudakov form factor. Finally, I end by discussing generalized event shapes in $e^+e^-$ annihilation.
[ { "created": "Wed, 22 Jul 2009 17:40:05 GMT", "version": "v1" } ]
2011-07-19
[ [ "Fleming", "Sean", "" ] ]
In this talk I give an overview of soft collinear effective theory (SCET), including a discussion of some recent advances. First, I briefly cover the foundation upon which SCET is built, namely QCD factorization, and review the theoretical framework of SCET. Next, I cover some recent calculations involving SCET. Since there are more interesting results than I can cover, I have picked four that that I find particularly exciting. The first two topics are dynamical threshold enhancements in Drell-Yan and resummation of higgs production at the LHC. Both topics center on the resummation of large Sudakov logarithms, however, for each there is a twist. In the case of threshold enhancements in Drell-Yan, it is partonic, not hadronic logarithms that are summed. In the case of higgs production at the LHC, the twist is that the logarithms are of a time-like scale. The third topic highlighted is electroweak corrections at high energy. In particular the electroweak Sudakov form factor. Finally, I end by discussing generalized event shapes in $e^+e^-$ annihilation.
1806.09407
Yu. A. Simonov
Z.V Khaidukov, M.S Lukashov and Yu.A.Simonov
The speed of sound in QGP and SU(3) Yang-Mills theory
10 pages, 3 figures
Phys. Rev. D 98, 074031 (2018)
10.1103/PhysRevD.98.074031
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The speed of sound $C_{s}$ in the SU(3) and (2+1)QCD is calculated within the Field Correlator Method using the nonperturbative colour magnetic confinement and Polyakov loop interaction in the deconfined region.The resulting $C_{s}$ displays a discontinuity at $T=T_{c}$ in the SU(3) case. It is shown numerically and analytically that $ C^{2}_{s}$ never exceeds $\frac{1}{3}$ both for SU(3) and (2+1) QCD for vanishing chemical potential.A good agreement is found of our numerical results with the corresponding lattice data.
[ { "created": "Mon, 25 Jun 2018 12:03:16 GMT", "version": "v1" }, { "created": "Mon, 9 Jul 2018 11:54:35 GMT", "version": "v2" } ]
2018-11-07
[ [ "Khaidukov", "Z. V", "" ], [ "Lukashov", "M. S", "" ], [ "Simonov", "Yu. A.", "" ] ]
The speed of sound $C_{s}$ in the SU(3) and (2+1)QCD is calculated within the Field Correlator Method using the nonperturbative colour magnetic confinement and Polyakov loop interaction in the deconfined region.The resulting $C_{s}$ displays a discontinuity at $T=T_{c}$ in the SU(3) case. It is shown numerically and analytically that $ C^{2}_{s}$ never exceeds $\frac{1}{3}$ both for SU(3) and (2+1) QCD for vanishing chemical potential.A good agreement is found of our numerical results with the corresponding lattice data.
2211.04494
Alexey Vladimirov
Simone Rodini and Alexey Vladimirov
Factorization for quasi-TMD distributions of sub-leading power
34 pages, 4 figures, 1 table; in v2, updated text, several misprints corrected
null
null
null
hep-ph hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The quasi-transverse-momentum dependent (qTMD) distributions are equal-time correlators that can be computed within the lattice QCD approach. In the regime of large hadron's momentum, qTMD distributions are expressed in terms of standard TMD distributions via the factorization theorem. We derive the corresponding factorization theorem at the next-leading power (NLP), and, for the first time, we present the factorized expressions for a large class of qTMD distributions of sub-leading power. The NLP expression contains TMD distributions of twist-two, twist-three, and a new lattice-specific nonperturbative function. We point out that some of the qTMD distributions considered in this work can be employed to extract the Collins-Soper kernel using the standard techniques of different-momenta-ratio. We provide NLO expressions for all the elements of the factorization theorem. Also, for the first time, we explicitly demonstrate the restoration of boost invariance in NLP TMD factorization.
[ { "created": "Tue, 8 Nov 2022 19:00:18 GMT", "version": "v1" }, { "created": "Wed, 26 Apr 2023 15:50:38 GMT", "version": "v2" } ]
2023-04-27
[ [ "Rodini", "Simone", "" ], [ "Vladimirov", "Alexey", "" ] ]
The quasi-transverse-momentum dependent (qTMD) distributions are equal-time correlators that can be computed within the lattice QCD approach. In the regime of large hadron's momentum, qTMD distributions are expressed in terms of standard TMD distributions via the factorization theorem. We derive the corresponding factorization theorem at the next-leading power (NLP), and, for the first time, we present the factorized expressions for a large class of qTMD distributions of sub-leading power. The NLP expression contains TMD distributions of twist-two, twist-three, and a new lattice-specific nonperturbative function. We point out that some of the qTMD distributions considered in this work can be employed to extract the Collins-Soper kernel using the standard techniques of different-momenta-ratio. We provide NLO expressions for all the elements of the factorization theorem. Also, for the first time, we explicitly demonstrate the restoration of boost invariance in NLP TMD factorization.
hep-ph/0008045
Liu Chun
Jong-Phil Lee, Chun Liu, and H. S. Song
Excited Heavy Baryon Masses from the 1/N_c Expansion of HQET
9 pages, latex, no figure, uses sprocl.sty (included). Talk by Chun Liu at the workshop on Non-Perturbative Methods and Lattice QCD (Guangzhou, May 15-21, 2000)
null
10.1142/9789812811370_0005
ASITP-2000-008, SNUTP 00-021
hep-ph
null
The mass spectra of the L=1 orbitally excited heavy baryons with light quarks in both the spin-flavor symmetric and the mixed representations are studied by the $1/N_c$ expansion method in the framework of the heavy quark effective theory. The mixing effect between the baryons in the two representations is also considered. The general pattern of the spectrum is predicted which will be verified by the experiments in the near future.
[ { "created": "Fri, 4 Aug 2000 12:53:41 GMT", "version": "v1" } ]
2017-08-23
[ [ "Lee", "Jong-Phil", "" ], [ "Liu", "Chun", "" ], [ "Song", "H. S.", "" ] ]
The mass spectra of the L=1 orbitally excited heavy baryons with light quarks in both the spin-flavor symmetric and the mixed representations are studied by the $1/N_c$ expansion method in the framework of the heavy quark effective theory. The mixing effect between the baryons in the two representations is also considered. The general pattern of the spectrum is predicted which will be verified by the experiments in the near future.
2312.05206
Paride Paradisi
L.C. Bresciani, G. Levati, P. Mastrolia, P. Paradisi
Anomalous Dimensions via on-shell Methods: Operator Mixing and Leading Mass Effects
6 pages, 4 figures
null
null
null
hep-ph hep-th
http://creativecommons.org/licenses/by-nc-nd/4.0/
We elaborate on the application of on-shell and unitarity-based methods for evaluating renormalization group coefficients, and generalize this framework to account for the mixing of operators with different dimensions and leading mass effects. We derive a master formula for anomalous dimensions stemming from the general structure of operator mixings, up to two-loop order, and show how the Higgs low-energy theorem can be exploited to include leading mass effects. A few applications on the renormalization properties of popular effective field theories showcase the strength of the proposed approach, which drastically reduces the complexity of standard loop calculations. Our results provide a powerful tool to interpret experimental measurements of low-energy observables, such as flavor violating processes or electric and magnetic dipole moments, as induced by new physics emerging above the electroweak scale.
[ { "created": "Fri, 8 Dec 2023 17:50:29 GMT", "version": "v1" } ]
2023-12-11
[ [ "Bresciani", "L. C.", "" ], [ "Levati", "G.", "" ], [ "Mastrolia", "P.", "" ], [ "Paradisi", "P.", "" ] ]
We elaborate on the application of on-shell and unitarity-based methods for evaluating renormalization group coefficients, and generalize this framework to account for the mixing of operators with different dimensions and leading mass effects. We derive a master formula for anomalous dimensions stemming from the general structure of operator mixings, up to two-loop order, and show how the Higgs low-energy theorem can be exploited to include leading mass effects. A few applications on the renormalization properties of popular effective field theories showcase the strength of the proposed approach, which drastically reduces the complexity of standard loop calculations. Our results provide a powerful tool to interpret experimental measurements of low-energy observables, such as flavor violating processes or electric and magnetic dipole moments, as induced by new physics emerging above the electroweak scale.
0810.4274
Pedro Jimenez-Delgado
P. Jimenez-Delgado, E. Reya
Dynamical NNLO parton distributions
44 pages, 15 figures; minor changes, footnote added
Phys.Rev.D79:074023,2009
10.1103/PhysRevD.79.074023
DOTH-0805
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Utilizing recent DIS measurements (\sigma_r, F_{2,3,L}) and data on hadronic dilepton production we determine at NNLO (3-loop) of QCD the dynamical parton distributions of the nucleon generated radiatively from valencelike positive input distributions at an optimally chosen low resolution scale (Q_0^2 < 1 GeV^2). These are compared with `standard' NNLO distributions generated from positive input distributions at some fixed and higher resolution scale (Q_0^2 > 1 GeV^2). Although the NNLO corrections imply in both approaches an improved value of \chi^2, typically \chi^2_{NNLO} \simeq 0.9 \chi^2_{NLO}, present DIS data are still not sufficiently accurate to distinguish between NLO results and the minute NNLO effects of a few percent, despite of the fact that the dynamical NNLO uncertainties are somewhat smaller than the NLO ones and both are, as expected, smaller than those of their `standard' counterparts. The dynamical predictions for F_L(x,Q^2) become perturbatively stable already at Q^2 = 2-3 GeV^2 where precision measurements could even delineate NNLO effects in the very small-x region. This is in contrast to the common `standard' approach but NNLO/NLO differences are here less distinguishable due to the much larger 1\sigma uncertainty bands. Within the dynamical approach we obtain \alpha_s(M_Z^2)=0.1124 \pm 0.0020, whereas the somewhat less constrained `standard' fit gives \alpha_s(M_Z^2)=0.1158 \pm 0.0035.
[ { "created": "Thu, 23 Oct 2008 13:23:14 GMT", "version": "v1" }, { "created": "Wed, 15 Apr 2009 13:59:00 GMT", "version": "v2" } ]
2013-05-29
[ [ "Jimenez-Delgado", "P.", "" ], [ "Reya", "E.", "" ] ]
Utilizing recent DIS measurements (\sigma_r, F_{2,3,L}) and data on hadronic dilepton production we determine at NNLO (3-loop) of QCD the dynamical parton distributions of the nucleon generated radiatively from valencelike positive input distributions at an optimally chosen low resolution scale (Q_0^2 < 1 GeV^2). These are compared with `standard' NNLO distributions generated from positive input distributions at some fixed and higher resolution scale (Q_0^2 > 1 GeV^2). Although the NNLO corrections imply in both approaches an improved value of \chi^2, typically \chi^2_{NNLO} \simeq 0.9 \chi^2_{NLO}, present DIS data are still not sufficiently accurate to distinguish between NLO results and the minute NNLO effects of a few percent, despite of the fact that the dynamical NNLO uncertainties are somewhat smaller than the NLO ones and both are, as expected, smaller than those of their `standard' counterparts. The dynamical predictions for F_L(x,Q^2) become perturbatively stable already at Q^2 = 2-3 GeV^2 where precision measurements could even delineate NNLO effects in the very small-x region. This is in contrast to the common `standard' approach but NNLO/NLO differences are here less distinguishable due to the much larger 1\sigma uncertainty bands. Within the dynamical approach we obtain \alpha_s(M_Z^2)=0.1124 \pm 0.0020, whereas the somewhat less constrained `standard' fit gives \alpha_s(M_Z^2)=0.1158 \pm 0.0035.
hep-ph/0102277
Hans Volker Klapdor
H.V. Klapdor-Kleingrothaus (Max-Planck-Institut fuer Kernphysik, Heidelberg, Germany)
GENIUS - A New Facility of Non-Accelerator Particle Physics
6 pages, revtex, 5 figures, Talk was presented at International Europhysics Neutrino Oscillation Workshop, Conca Specchiulla (Otranto, Italy), September 9-16, 2000, to be published in Nucl. Phys. B (2001), Home Page of Heidelberg Non-Accelerator Particle Physics Group: http://www.mpi-hd.mpg.de/non_acc/
Nucl.Phys.Proc.Suppl. 100 (2001) 350-355
10.1016/S0920-5632(01)01470-0
null
hep-ph
null
The GENIUS (\underline {Ge}rmanium in Liquid \underline {Ni}trogen \underline {U}nderground \underline {S}etup) project has been proposed in 1997 \cite{KK-BEY97} as first third generation double beta decay project, with a sensitivity aiming down to a level of an effective neutrino mass of $<m>\sim$ 0.01 - 0.001 eV. Such sensitivity has been shown to be indispensable to solve the question of the structure of the neutrino mass matrix which cannot be solved by neutrino oscillation experiments alone \cite{KKPS}. It will allow broad access also to many other topics of physics beyond the Standard Model of particle physics at the multi-TeV scale. For search of cold dark matter GENIUS will cover almost the full range of the parameter space of predictions of SUSY for neutralinos as dark matter \cite{KK-Ram,Bed-KK2}. Finally, GENIUS has the potential to be the first real-time detector for low-energy (pp and $^7{Be}$) solar neutrinos \cite{Bau-KK,KKPropos99}. A GENIUS-Test Facility has just been funded and will come into operation by end of 2001.
[ { "created": "Thu, 22 Feb 2001 16:42:28 GMT", "version": "v1" } ]
2012-03-24
[ [ "Klapdor-Kleingrothaus", "H. V.", "", "Max-Planck-Institut fuer Kernphysik,\n Heidelberg, Germany" ] ]
The GENIUS (\underline {Ge}rmanium in Liquid \underline {Ni}trogen \underline {U}nderground \underline {S}etup) project has been proposed in 1997 \cite{KK-BEY97} as first third generation double beta decay project, with a sensitivity aiming down to a level of an effective neutrino mass of $<m>\sim$ 0.01 - 0.001 eV. Such sensitivity has been shown to be indispensable to solve the question of the structure of the neutrino mass matrix which cannot be solved by neutrino oscillation experiments alone \cite{KKPS}. It will allow broad access also to many other topics of physics beyond the Standard Model of particle physics at the multi-TeV scale. For search of cold dark matter GENIUS will cover almost the full range of the parameter space of predictions of SUSY for neutralinos as dark matter \cite{KK-Ram,Bed-KK2}. Finally, GENIUS has the potential to be the first real-time detector for low-energy (pp and $^7{Be}$) solar neutrinos \cite{Bau-KK,KKPropos99}. A GENIUS-Test Facility has just been funded and will come into operation by end of 2001.
hep-ph/0506330
G. Peter Lepage
G. Peter Lepage
What is Renormalization?
23 pages, 5 figs (uses feynmp). Talk given at TASI'89 in Boulder
Proceedings of TASI'89: From Actions to Answers, edited by T. DeGrand and D. Toussaint, World Scientific (1989)
null
null
hep-ph
null
"Preprint" of paper from 1989 that wasn't arxiv'ed at the time. Abstract: Our understanding of quantum field theories, and, in particular, of renomalization has changed radically in recent years; renormalization is no longer a deeply mysterious procedure for hiding embarrassing infinities. This talk is a non-technical presentation of modern attitudes towards renormalization, and their implications (both theoretical and experimental) for quantum theories of electromagnetic, strong, and weak interactions.
[ { "created": "Thu, 30 Jun 2005 16:39:52 GMT", "version": "v1" } ]
2007-05-23
[ [ "Lepage", "G. Peter", "" ] ]
"Preprint" of paper from 1989 that wasn't arxiv'ed at the time. Abstract: Our understanding of quantum field theories, and, in particular, of renomalization has changed radically in recent years; renormalization is no longer a deeply mysterious procedure for hiding embarrassing infinities. This talk is a non-technical presentation of modern attitudes towards renormalization, and their implications (both theoretical and experimental) for quantum theories of electromagnetic, strong, and weak interactions.
1710.01743
Filippo Sala
Alberto Mariotti, Diego Redigolo, Filippo Sala, Kohsaku Tobioka
New LHC bound on low-mass diphoton resonances
7 pages + appendices, 5 figures, 2 tables. v2: discussion improved, new bound derived also from Tevatron, conclusions unchanged. v3: matches PLB version
null
10.1016/j.physletb.2018.06.039
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive a new bound on diphoton resonances using inclusive diphoton cross section measurements at the LHC, in the so-far poorly constrained mass range between the Upsilon and the SM Higgs. This bound sets the current best limit on axion-like particles that couple to gluons and photons, for masses between 10 and 65 GeV. We also estimate indicative sensitivities of a dedicated diphoton LHC search in the same mass region, at 7, 8 and 14 TeV. As a byproduct of our analysis, we comment on the axion-like particle interpretation of the CMS excesses in low-mass dijet and diphoton searches.
[ { "created": "Wed, 4 Oct 2017 18:00:50 GMT", "version": "v1" }, { "created": "Mon, 27 Nov 2017 15:52:29 GMT", "version": "v2" }, { "created": "Mon, 10 Sep 2018 16:15:32 GMT", "version": "v3" } ]
2018-09-11
[ [ "Mariotti", "Alberto", "" ], [ "Redigolo", "Diego", "" ], [ "Sala", "Filippo", "" ], [ "Tobioka", "Kohsaku", "" ] ]
We derive a new bound on diphoton resonances using inclusive diphoton cross section measurements at the LHC, in the so-far poorly constrained mass range between the Upsilon and the SM Higgs. This bound sets the current best limit on axion-like particles that couple to gluons and photons, for masses between 10 and 65 GeV. We also estimate indicative sensitivities of a dedicated diphoton LHC search in the same mass region, at 7, 8 and 14 TeV. As a byproduct of our analysis, we comment on the axion-like particle interpretation of the CMS excesses in low-mass dijet and diphoton searches.
1210.7338
Uzhinsky Vladimir Dr.Sc.
V. Uzhinsky, A. Galoyan
Improved Systematic of pp Elastic Scattering Data
15 pages, 61 figures
null
null
null
hep-ph astro-ph.HE hep-ex nucl-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Unified systematic of elastic scattering data (USESD) proposed by the authors (arxiv:1111.4984 [hep-ph]) is based on symmetrized 2-dimensional Fermi distribution for pp elastic scattering amplitude in the impact parameter representation. It allows to describe differential cross sections of the reactions up to |t| ~ 1.75 (GeV/c)$^2$. To extend it to higher |t| values we consider a two coherent exponential parametrization of the cross sections and show that it cannot describe the cross sections at small |t| at $P_{lab}>$ 10 GeV/c. We extract a description of high |t| region from the parameterization and couple it with USESD. As a result, we obtained a good description of all pp elastic scattering data at $P_{lab}>$ 10 GeV/c. It can be easily used in Glauber Monte Carlo codes for calculations of nucleus-nucleus interaction properties.
[ { "created": "Sat, 27 Oct 2012 15:44:11 GMT", "version": "v1" } ]
2012-10-30
[ [ "Uzhinsky", "V.", "" ], [ "Galoyan", "A.", "" ] ]
Unified systematic of elastic scattering data (USESD) proposed by the authors (arxiv:1111.4984 [hep-ph]) is based on symmetrized 2-dimensional Fermi distribution for pp elastic scattering amplitude in the impact parameter representation. It allows to describe differential cross sections of the reactions up to |t| ~ 1.75 (GeV/c)$^2$. To extend it to higher |t| values we consider a two coherent exponential parametrization of the cross sections and show that it cannot describe the cross sections at small |t| at $P_{lab}>$ 10 GeV/c. We extract a description of high |t| region from the parameterization and couple it with USESD. As a result, we obtained a good description of all pp elastic scattering data at $P_{lab}>$ 10 GeV/c. It can be easily used in Glauber Monte Carlo codes for calculations of nucleus-nucleus interaction properties.
2209.01372
Francesco Giovanni Celiberto
Francesco Giovanni Celiberto, Michael Fucilla and Alessandro Papa
The high-energy limit of perturbative QCD: Theory and phenomenology
8 pages, 2 figures; Presented by Alessandro Papa at QCD@Work-International Workshop on QCD-Theory and Experiment, 27-30 June 2022; version published in the conference proceedings by EPJ Web of Conferences
EPJ Web Conf. 270 (2022) 00001
10.1051/epjconf/202227000001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
After a brief introduction of formal and phenomenological progresses in the study of the high-energy limit of perturbative QCD, we present arguments supporting the statement that the inclusive emission of Higgs bosons or heavy-flavored hadrons acts as fair stabilizer of high-energy resummed differential distributions. We come out with the message that the hybrid high-energy and collinear factorization, built in term of the next-to-leading logarithmic resummation \emph{\`a la} BFKL and supplemented by collinear parton distributions and fragmentation functions, is a valid and powerful tool to gauge the feasibility of precision analyses of QCD in its high-energy limit.
[ { "created": "Sat, 3 Sep 2022 08:54:52 GMT", "version": "v1" }, { "created": "Fri, 23 Dec 2022 10:10:20 GMT", "version": "v2" }, { "created": "Fri, 6 Jan 2023 15:24:11 GMT", "version": "v3" } ]
2023-01-09
[ [ "Celiberto", "Francesco Giovanni", "" ], [ "Fucilla", "Michael", "" ], [ "Papa", "Alessandro", "" ] ]
After a brief introduction of formal and phenomenological progresses in the study of the high-energy limit of perturbative QCD, we present arguments supporting the statement that the inclusive emission of Higgs bosons or heavy-flavored hadrons acts as fair stabilizer of high-energy resummed differential distributions. We come out with the message that the hybrid high-energy and collinear factorization, built in term of the next-to-leading logarithmic resummation \emph{\`a la} BFKL and supplemented by collinear parton distributions and fragmentation functions, is a valid and powerful tool to gauge the feasibility of precision analyses of QCD in its high-energy limit.
1008.2845
Kang Xian-Wei
X. W. Kang, H. B. Li and G. R. Lu
Probe $\Lambda - \bar{\Lambda}$ oscillation in $J/\psi \rightarrow \Lambda\,\bar\Lambda$ decay at BES-III
4 pages, 1 figure, Talk given at "the 8th symposium on advanced topics of interdisciplinary fields of particle physics, nuclear physics and cosmology", Sichuan province, China, 08/18-08/22, 2009
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the possible searching for the oscillation by coherent $\Lambda\bar{\Lambda}$ production in $J/\psi \rightarrow \Lambda \bar{\Lambda}$ decay process. The sensitivity of measurement of $\Lambda - \bar{\Lambda}$ oscillation in the external field at BES-III experiment is considered. These considerations indicate an alternative way to probe the $\Delta B =2$ amplitude in addition to neutron oscillation experiments. Both coherent and time-dependent information can be used to extract $\Lambda -\bar{\Lambda}$ oscillation parameter. With one year's luminosity at BES-III, we can set an upper limit of $\delta m < 10^{-15}$ MeV at 90% confidence level, corresponding to about $10^{-6}$ s of $\Lam-\Lamb$ oscillation time.
[ { "created": "Tue, 17 Aug 2010 08:12:23 GMT", "version": "v1" }, { "created": "Sat, 25 Dec 2010 03:25:51 GMT", "version": "v2" } ]
2010-12-30
[ [ "Kang", "X. W.", "" ], [ "Li", "H. B.", "" ], [ "Lu", "G. R.", "" ] ]
We discuss the possible searching for the oscillation by coherent $\Lambda\bar{\Lambda}$ production in $J/\psi \rightarrow \Lambda \bar{\Lambda}$ decay process. The sensitivity of measurement of $\Lambda - \bar{\Lambda}$ oscillation in the external field at BES-III experiment is considered. These considerations indicate an alternative way to probe the $\Delta B =2$ amplitude in addition to neutron oscillation experiments. Both coherent and time-dependent information can be used to extract $\Lambda -\bar{\Lambda}$ oscillation parameter. With one year's luminosity at BES-III, we can set an upper limit of $\delta m < 10^{-15}$ MeV at 90% confidence level, corresponding to about $10^{-6}$ s of $\Lam-\Lamb$ oscillation time.
hep-ph/9807518
S. Y. Tsai
Y.Kouchi, A.Shinbori, Y.Takeuchi and S.Y.Tsai
Further Study on Possible Violation of CP, T and CPT Symmetries in the $K^0$-$\bar{K^0}$ System --- Remarks and Results ---
16 pages
null
null
NUP-A-98-10
hep-ph
null
We demonstrate how one may identify or constrain possible violation of $CP$, $T$ and $CPT$ symmetries in the $K^0$-$\bar{K^0}$ system in a way as phenomenological and comprehensive as possibie. For this purpose, we first introduce parameters which represent violation of these symmetries in mixing parameters and decay amplitudes in a well-defined way. After discussing some characteristics of these parameters, we derive formulae which relate them to the experimentally measured quantities. We then carry out a numerical analysis with the help of the Bell-Steinberger relation to derive constraints to these violating parameters from available experimental data. Finally, we compare our parametrization and procedure of analysis with those employed in the recent literature.
[ { "created": "Tue, 28 Jul 1998 04:18:52 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kouchi", "Y.", "" ], [ "Shinbori", "A.", "" ], [ "Takeuchi", "Y.", "" ], [ "Tsai", "S. Y.", "" ] ]
We demonstrate how one may identify or constrain possible violation of $CP$, $T$ and $CPT$ symmetries in the $K^0$-$\bar{K^0}$ system in a way as phenomenological and comprehensive as possibie. For this purpose, we first introduce parameters which represent violation of these symmetries in mixing parameters and decay amplitudes in a well-defined way. After discussing some characteristics of these parameters, we derive formulae which relate them to the experimentally measured quantities. We then carry out a numerical analysis with the help of the Bell-Steinberger relation to derive constraints to these violating parameters from available experimental data. Finally, we compare our parametrization and procedure of analysis with those employed in the recent literature.
hep-ph/0510170
Eung Jin Chun
E.J. Chun and S. Scopel
Soft Leptogenesis in Higgs Triplet Model
17 pages, 5 figures; version accepted for publication
Phys.Lett. B636 (2006) 278-285
10.1016/j.physletb.2006.03.061
null
hep-ph
null
We consider the minimal supersymmetric triplet seesaw model as the origin of neutrino masses and mixing as well as of the baryon asymmetry of the Universe, which is generated through soft leptogenesis employing a CP violating phase and a resonant behavior in the supersymmetry breaking sector. We calculate the full gauge--annihilation cross section for the Higgs triplets, including all relevant supersymmetric intermediate and final states, as well as coannihilations with the fermionic superpartners of the triplets. We find that these gauge annihilation processes strongly suppress the resulting lepton asymmetry. As a consequence of this, successful leptogenesis can occur only for a triplet mass at the TeV scale, where the contribution of soft supersymmetry breaking terms enhances the CP and lepton asymmetry. This opens up an interesting opportunity for testing the model in future colliders.
[ { "created": "Thu, 13 Oct 2005 08:34:27 GMT", "version": "v1" }, { "created": "Wed, 24 May 2006 08:20:35 GMT", "version": "v2" } ]
2009-11-11
[ [ "Chun", "E. J.", "" ], [ "Scopel", "S.", "" ] ]
We consider the minimal supersymmetric triplet seesaw model as the origin of neutrino masses and mixing as well as of the baryon asymmetry of the Universe, which is generated through soft leptogenesis employing a CP violating phase and a resonant behavior in the supersymmetry breaking sector. We calculate the full gauge--annihilation cross section for the Higgs triplets, including all relevant supersymmetric intermediate and final states, as well as coannihilations with the fermionic superpartners of the triplets. We find that these gauge annihilation processes strongly suppress the resulting lepton asymmetry. As a consequence of this, successful leptogenesis can occur only for a triplet mass at the TeV scale, where the contribution of soft supersymmetry breaking terms enhances the CP and lepton asymmetry. This opens up an interesting opportunity for testing the model in future colliders.
0812.0868
Urjit A. Yajnik
Sasmita Mishra, Anjishnu Sarkar and Urjit A. Yajnik
Gauge mediated supersymmetry breaking and the cosmology of Left-Right symmetric model
null
Phys.Rev.D79:065038,2009
10.1103/PhysRevD.79.065038
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Left-Right symmetry including supersymmetry presents an important class of gauge models which may possess natural solutions to many issues of phenomenology. Cosmology of such models indicates a phase transition accompanied by domain walls. Such walls must be unstable in order to not conflict with standard cosmology, and can further be shown to assist with open issues of cosmology such as dilution of unwanted relic densities and leptogenesis. In this paper we construct a model of gauge mediated supersymmetry breaking in which parity breaking is also signalled along with supersymmetry breaking and so as to be consistent with cosmological requirements. It is shown that addressing all the stated cosmological issues requires an extent of fine tuning, while in the absence of fine tuning, leptogenesis accompanying successful completion of the phase transition is still viable.
[ { "created": "Thu, 4 Dec 2008 07:11:11 GMT", "version": "v1" } ]
2009-11-06
[ [ "Mishra", "Sasmita", "" ], [ "Sarkar", "Anjishnu", "" ], [ "Yajnik", "Urjit A.", "" ] ]
Left-Right symmetry including supersymmetry presents an important class of gauge models which may possess natural solutions to many issues of phenomenology. Cosmology of such models indicates a phase transition accompanied by domain walls. Such walls must be unstable in order to not conflict with standard cosmology, and can further be shown to assist with open issues of cosmology such as dilution of unwanted relic densities and leptogenesis. In this paper we construct a model of gauge mediated supersymmetry breaking in which parity breaking is also signalled along with supersymmetry breaking and so as to be consistent with cosmological requirements. It is shown that addressing all the stated cosmological issues requires an extent of fine tuning, while in the absence of fine tuning, leptogenesis accompanying successful completion of the phase transition is still viable.
1706.04931
Arunansu Sil
Purusottam Ghosh, Abhijit Kumar Saha and Arunansu Sil
Study of Electroweak Vacuum Stability from Extended Higgs Portal of Dark Matter and Neutrinos
40 pages, 21 figures, revised version to appear in Physical Review D
Phys. Rev. D 97, 075034 (2018)
10.1103/PhysRevD.97.075034
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the electroweak vacuum stability in an extended version of the Standard Model which incorporates two additional singlet scalar fields and three right handed neutrinos. One of these extra scalars plays the role of dark matter while the other scalar not only helps in making the electroweak vacuum stable but also opens up the low mass window of the scalar singlet dark matter (< 500 GeV). We consider the effect of large neutrino Yukawa coupling on the running of Higgs quartic coupling. We have analyzed the constraints on the model and identify the range of parameter space which is consistent with neutrino mass, appropriate relic density and direct search limits from the latest XENON 1T preliminary result as well as in realizing the stability of the electroweak vacuum upto the Planck scale.
[ { "created": "Thu, 15 Jun 2017 15:37:27 GMT", "version": "v1" }, { "created": "Sat, 31 Mar 2018 18:12:51 GMT", "version": "v2" } ]
2018-05-02
[ [ "Ghosh", "Purusottam", "" ], [ "Saha", "Abhijit Kumar", "" ], [ "Sil", "Arunansu", "" ] ]
We investigate the electroweak vacuum stability in an extended version of the Standard Model which incorporates two additional singlet scalar fields and three right handed neutrinos. One of these extra scalars plays the role of dark matter while the other scalar not only helps in making the electroweak vacuum stable but also opens up the low mass window of the scalar singlet dark matter (< 500 GeV). We consider the effect of large neutrino Yukawa coupling on the running of Higgs quartic coupling. We have analyzed the constraints on the model and identify the range of parameter space which is consistent with neutrino mass, appropriate relic density and direct search limits from the latest XENON 1T preliminary result as well as in realizing the stability of the electroweak vacuum upto the Planck scale.
1311.3442
Jian Wang
Jian Wang
Determining the masses of invisible particles: Application to Higgs boson invisible decay
10 pages, 8 figures, more discussion and references added, version published in Phys.Rev.D
Phys. Rev. D 89, 093019 (2014)
10.1103/PhysRevD.89.093019
MITP/13-069
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
To know the total width of the recently discovered Higgs boson particle, it is important to measure the invisible decay width of the Higgs boson. However, the signal for this measurement at the LHC, i.e., a charged lepton pair and missing energy in the final state, cannot be definitely understood as the product of the intermediate produced $Z$ and $H$ bosons due to the possible interaction between dark matter and a $Z$ boson or quarks, which can be described by representative effective operators. First, we consider the relic abundance, the LUX direct detection experiment and the result of searching for Higgs boson invisible decay at the LEP and LHC to find the allowed parameter region for the effective operators. Then we investigate the transverse momentum distribution of the missing energy and propose two observables that can be used to distinguish the different underlying processes. Moreover, with these two observables, we may be able to determine the masses of invisible particles.
[ { "created": "Thu, 14 Nov 2013 10:25:34 GMT", "version": "v1" }, { "created": "Sat, 24 May 2014 13:23:41 GMT", "version": "v2" } ]
2014-05-28
[ [ "Wang", "Jian", "" ] ]
To know the total width of the recently discovered Higgs boson particle, it is important to measure the invisible decay width of the Higgs boson. However, the signal for this measurement at the LHC, i.e., a charged lepton pair and missing energy in the final state, cannot be definitely understood as the product of the intermediate produced $Z$ and $H$ bosons due to the possible interaction between dark matter and a $Z$ boson or quarks, which can be described by representative effective operators. First, we consider the relic abundance, the LUX direct detection experiment and the result of searching for Higgs boson invisible decay at the LEP and LHC to find the allowed parameter region for the effective operators. Then we investigate the transverse momentum distribution of the missing energy and propose two observables that can be used to distinguish the different underlying processes. Moreover, with these two observables, we may be able to determine the masses of invisible particles.
2209.14318
Ana Luisa Foguel
Ana Luisa Foguel and Eduardo S. Fraga
Analytic approach to axion-like-particle emission in core-collapse supernovae
8 pages, 8 figures; ARtiSANS code available at https://github.com/anafoguel/ARtiSANS ; v2: new section discussing the validity of the analytic approximation; matches version published at Astropart. Phys
null
10.1016/j.astropartphys.2023.102855
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the impact of a presumed axion-like-particle (ALP) emission in a core-collapse supernova explosion on neutrino luminosities and mean energies employing a relatively simple analytic description. We compute the nuclear Bremsstrahlung and Primakoff axion luminosities as functions of the protoneutron star (PNS) parameters and discuss how the ALP luminosities compete with the neutrino emission, modifying the total PNS thermal energy dissipation. Our results are publicly available in the python package ARtiSANS, which can be used to compute the neutrino and axion observables for different choices of parameters.
[ { "created": "Wed, 28 Sep 2022 18:00:06 GMT", "version": "v1" }, { "created": "Tue, 30 May 2023 14:21:15 GMT", "version": "v2" } ]
2023-05-31
[ [ "Foguel", "Ana Luisa", "" ], [ "Fraga", "Eduardo S.", "" ] ]
We investigate the impact of a presumed axion-like-particle (ALP) emission in a core-collapse supernova explosion on neutrino luminosities and mean energies employing a relatively simple analytic description. We compute the nuclear Bremsstrahlung and Primakoff axion luminosities as functions of the protoneutron star (PNS) parameters and discuss how the ALP luminosities compete with the neutrino emission, modifying the total PNS thermal energy dissipation. Our results are publicly available in the python package ARtiSANS, which can be used to compute the neutrino and axion observables for different choices of parameters.
hep-ph/0703040
Masafumi Koike
Masafumi Koike, Masako Saito
An illustration and analysis of the degeneracy in the search for the leptonic CP-violating angle and the neutrino mass hierarchy
PTPTeX, 23 pages, 11 figures. Minor updates in accordance with the published version
Prog.Theor.Phys.118:521-543,2007
10.1143/PTP.118.521
STUPP-07-189
hep-ph
null
Determination of the value of the leptonic CP-violating phase deltaand the neutrino mass hierarchy sgn(dm2_31) through long baselineneutrino oscillation experiments is systematically analyzed. We notethat the two oscillation spectra are difficult to discriminate andlead to the degeneracy when they are peaked at the same energy andhave the same peak probability. The condition of peak-matching istherefore introduced as a criterion for the presence of degeneracy.The matching of peaks is visualized as an intersection of trajectoriestraced by the peak of an oscillation spectrum while the value of deltais varied from 0 to 2pi. We numerically calculate a pair oftrajectories for a pair of hierarchies and examine the degeneracy,especially that concerning the hierarchy. We formulate the trajectoryin terms of analytic expressions and evaluate the critical length,which is shown to be proportional to 1/sin(theta_13). In view of ouranalysis, we discuss future prospects to solve the hierarchydegeneracy with regard to the following four approaches: elongatingthe baseline length sufficiently, using both neutrinos andanti-neutrinos, combining experiments with different baseline lengths,and observing two or more oscillation peaks.
[ { "created": "Sun, 4 Mar 2007 20:55:41 GMT", "version": "v1" }, { "created": "Fri, 30 Nov 2007 13:14:50 GMT", "version": "v2" } ]
2008-11-26
[ [ "Koike", "Masafumi", "" ], [ "Saito", "Masako", "" ] ]
Determination of the value of the leptonic CP-violating phase deltaand the neutrino mass hierarchy sgn(dm2_31) through long baselineneutrino oscillation experiments is systematically analyzed. We notethat the two oscillation spectra are difficult to discriminate andlead to the degeneracy when they are peaked at the same energy andhave the same peak probability. The condition of peak-matching istherefore introduced as a criterion for the presence of degeneracy.The matching of peaks is visualized as an intersection of trajectoriestraced by the peak of an oscillation spectrum while the value of deltais varied from 0 to 2pi. We numerically calculate a pair oftrajectories for a pair of hierarchies and examine the degeneracy,especially that concerning the hierarchy. We formulate the trajectoryin terms of analytic expressions and evaluate the critical length,which is shown to be proportional to 1/sin(theta_13). In view of ouranalysis, we discuss future prospects to solve the hierarchydegeneracy with regard to the following four approaches: elongatingthe baseline length sufficiently, using both neutrinos andanti-neutrinos, combining experiments with different baseline lengths,and observing two or more oscillation peaks.
hep-ph/0602192
Yuuki Shinbara
M. Ibe, K.-I. Izawa, Y. Shinbara, and T.T. Yanagida
Minimal Supergravity, Inflation, and All That
15pages, 4figures, text and refs. added
Phys.Lett. B637 (2006) 21-26
10.1016/j.physletb.2006.04.011
UT-06-01
hep-ph
null
We consider an inflationary model in the hidden-sector broken supergravity with an effectively large cutoff. The inflaton decay into right-handed neutrinos naturally causes the observed baryon asymmetry of the universe with a reheating temperature low enough to avoid the gravitino overproduction. We emphasize that all the phenomenological requirements from cosmology and particle physics are satisfied in the large-cutoff theory.
[ { "created": "Tue, 21 Feb 2006 12:11:33 GMT", "version": "v1" }, { "created": "Thu, 13 Apr 2006 13:23:28 GMT", "version": "v2" } ]
2009-11-11
[ [ "Ibe", "M.", "" ], [ "Izawa", "K. -I.", "" ], [ "Shinbara", "Y.", "" ], [ "Yanagida", "T. T.", "" ] ]
We consider an inflationary model in the hidden-sector broken supergravity with an effectively large cutoff. The inflaton decay into right-handed neutrinos naturally causes the observed baryon asymmetry of the universe with a reheating temperature low enough to avoid the gravitino overproduction. We emphasize that all the phenomenological requirements from cosmology and particle physics are satisfied in the large-cutoff theory.
0807.3264
Cristina Manuel
Massimo Mannarelli, Cristina Manuel and Basil A. Sa'd
Mutual friction in a cold color flavor locked superfluid and r-mode instabilities in compact stars
4 pages; comments and refs. added; it matches with published version
Phys.Rev.Lett.101:241101,2008
10.1103/PhysRevLett.101.241101
null
hep-ph astro-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Dissipative processes acting in rotating neutron stars are essential in preventing the growth of the r-mode instability. We estimate the damping time of r-modes of an hypothetical compact quark star made up by color flavor locked quark matter at a temperature $T \lesssim 0.01$ MeV. The dissipation that we consider is due to the the mutual friction force between the normal and the superfluid component arising from the elastic scattering of phonons with quantized vortices. This process is the dominant one for temperatures $T \lesssim 0.01$ MeV where the mean free path of phonons due to their self-interactions is larger than the radius of the star and they can be described as an ideal bosonic gas. We find that r-modes oscillations are efficiently damped by this mechanism for pulsars rotating at frequencies of the order of 1 Hz at most. Our analysis rules out the possibility that cold pulsars rotating at higher frequencies are entirely made up by color flavor locked quark matter.
[ { "created": "Mon, 21 Jul 2008 13:56:34 GMT", "version": "v1" }, { "created": "Mon, 15 Dec 2008 16:45:11 GMT", "version": "v2" } ]
2009-01-09
[ [ "Mannarelli", "Massimo", "" ], [ "Manuel", "Cristina", "" ], [ "Sa'd", "Basil A.", "" ] ]
Dissipative processes acting in rotating neutron stars are essential in preventing the growth of the r-mode instability. We estimate the damping time of r-modes of an hypothetical compact quark star made up by color flavor locked quark matter at a temperature $T \lesssim 0.01$ MeV. The dissipation that we consider is due to the the mutual friction force between the normal and the superfluid component arising from the elastic scattering of phonons with quantized vortices. This process is the dominant one for temperatures $T \lesssim 0.01$ MeV where the mean free path of phonons due to their self-interactions is larger than the radius of the star and they can be described as an ideal bosonic gas. We find that r-modes oscillations are efficiently damped by this mechanism for pulsars rotating at frequencies of the order of 1 Hz at most. Our analysis rules out the possibility that cold pulsars rotating at higher frequencies are entirely made up by color flavor locked quark matter.
0907.4519
Ioannis Bouras
I. Bouras, E. Molnar, H. Niemi, Z. Xu, A. El, O. Fochler, C. Greiner and D.H. Rischke
Development of relativistic shock waves in viscous gluon matter
4 pages, 3 figures - To appear in the conference proceedings for Quark Matter 2009, March 30 - April 4, Knoxville, Tennessee
Nucl.Phys.A830:741c-744c,2009
10.1016/j.nuclphysa.2009.10.121
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
To investigate the formation and the propagation of relativistic shock waves in viscous gluon matter we solve the relativistic Riemann problem using a microscopic parton cascade. We demonstrate the transition from ideal to viscous shock waves by varying the shear viscosity to entropy density ratio $\eta/s$. We show that an $\eta/s$ ratio larger than 0.2 prevents the development of well-defined shock waves on time scales typical for ultrarelativistic heavy-ion collisions. These findings are confirmed by viscous hydrodynamic calculations.
[ { "created": "Sun, 26 Jul 2009 21:11:16 GMT", "version": "v1" }, { "created": "Wed, 7 Oct 2009 19:53:06 GMT", "version": "v2" } ]
2009-11-18
[ [ "Bouras", "I.", "" ], [ "Molnar", "E.", "" ], [ "Niemi", "H.", "" ], [ "Xu", "Z.", "" ], [ "El", "A.", "" ], [ "Fochler", "O.", "" ], [ "Greiner", "C.", "" ], [ "Rischke", "D. H.", "" ] ]
To investigate the formation and the propagation of relativistic shock waves in viscous gluon matter we solve the relativistic Riemann problem using a microscopic parton cascade. We demonstrate the transition from ideal to viscous shock waves by varying the shear viscosity to entropy density ratio $\eta/s$. We show that an $\eta/s$ ratio larger than 0.2 prevents the development of well-defined shock waves on time scales typical for ultrarelativistic heavy-ion collisions. These findings are confirmed by viscous hydrodynamic calculations.
1009.5662
Bernd Kniehl
Mathias Butenschoen, Bernd A. Kniehl
Reconciling J/psi production at HERA, RHIC, Tevatron, and LHC with NRQCD factorization at next-to-leading order
5 pages, 10 figures; manuscript matches the one being printed in Phys. Rev. Lett
Phys.Rev.Lett.106:022003,2011
10.1103/PhysRevLett.106.022003
DESY 10-101
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the cross section of inclusive direct J/psi hadroproduction at next-to-leading order (NLO) within the factorization formalism of nonrelativistic quantum chromodynamics (NRQCD), including the full relativistic corrections due to the intermediate 1S_0^[8], 3S_1^[8], and 3P_J^[8] color-octet states. We perform a combined fit of the color-octet (CO) long-distance matrix elements to the transverse-momentum (p_T) distributions measured by CDF at the Fermilab Tevatron and H1 at DESY HERA and demonstrate that they also successfully describe the p_T distributions from PHENIX at BNL RHIC and CMS at the CERN LHC as well as the photon-proton c.m. energy and (with worse agreement) the inelasticity distributions from H1. This provides a first rigorous test of NRQCD factorization at NLO. In all experiments, the CO processes are shown to be indispensable.
[ { "created": "Tue, 28 Sep 2010 19:31:12 GMT", "version": "v1" }, { "created": "Fri, 17 Dec 2010 18:55:22 GMT", "version": "v2" }, { "created": "Tue, 11 Jan 2011 11:09:34 GMT", "version": "v3" } ]
2011-02-02
[ [ "Butenschoen", "Mathias", "" ], [ "Kniehl", "Bernd A.", "" ] ]
We calculate the cross section of inclusive direct J/psi hadroproduction at next-to-leading order (NLO) within the factorization formalism of nonrelativistic quantum chromodynamics (NRQCD), including the full relativistic corrections due to the intermediate 1S_0^[8], 3S_1^[8], and 3P_J^[8] color-octet states. We perform a combined fit of the color-octet (CO) long-distance matrix elements to the transverse-momentum (p_T) distributions measured by CDF at the Fermilab Tevatron and H1 at DESY HERA and demonstrate that they also successfully describe the p_T distributions from PHENIX at BNL RHIC and CMS at the CERN LHC as well as the photon-proton c.m. energy and (with worse agreement) the inelasticity distributions from H1. This provides a first rigorous test of NRQCD factorization at NLO. In all experiments, the CO processes are shown to be indispensable.
0812.4484
Jian Zhou Mr.
Jian Zhou, Feng Yuan, Zuo-Tang Liang
QCD Evolution of the Transverse Momentum Dependent Correlations
13 pages, 1 figure
Phys.Rev.D79:114022,2009
10.1103/PhysRevD.79.114022
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the QCD evolution for the twist-three quark-gluon correlation functions associated with the transverse momentum odd quark distributions. Different from that for the leading twist quark distributions, these evolution equations involve more general twist-three functions beyond the correlation functions themselves. They provide important information on nucleon structure, and can be studied in the semi-inclusive hadron production in deep inelastic scattering and Drell-Yan lepton pair production in $pp$ scattering process.
[ { "created": "Wed, 24 Dec 2008 05:15:31 GMT", "version": "v1" } ]
2009-07-09
[ [ "Zhou", "Jian", "" ], [ "Yuan", "Feng", "" ], [ "Liang", "Zuo-Tang", "" ] ]
We study the QCD evolution for the twist-three quark-gluon correlation functions associated with the transverse momentum odd quark distributions. Different from that for the leading twist quark distributions, these evolution equations involve more general twist-three functions beyond the correlation functions themselves. They provide important information on nucleon structure, and can be studied in the semi-inclusive hadron production in deep inelastic scattering and Drell-Yan lepton pair production in $pp$ scattering process.
1208.3293
Alessandro Papa
Dmitry Yu. Ivanov and Alessandro Papa
The NLO jet vertex for Mueller-Navelet and forward jets in the small-cone approximation
4 pages, 4 figures; presented at the XX International Workshop on Deep-Inelastic Scattering and Related Subjects, 26-30 March 2012, University of Bonn
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate in the next-to-leading order the impact factor (vertex) for the production of a forward high-$p_T$ jet, in the approximation of small aperture of the jet cone in the pseudorapidity-azimuthal angle plane. The final expression for the vertex turns out to be simple and easy to implement in numerical calculations.
[ { "created": "Thu, 16 Aug 2012 05:52:25 GMT", "version": "v1" } ]
2012-08-17
[ [ "Ivanov", "Dmitry Yu.", "" ], [ "Papa", "Alessandro", "" ] ]
We calculate in the next-to-leading order the impact factor (vertex) for the production of a forward high-$p_T$ jet, in the approximation of small aperture of the jet cone in the pseudorapidity-azimuthal angle plane. The final expression for the vertex turns out to be simple and easy to implement in numerical calculations.
2201.04977
Xin Zhang
Shao-Ping Li, Yuan-Yuan-Li, Xin-Shuai Yan and Xin Zhang
Next-to-tribimaximal mixing against CP violation and baryon asymmetry signs
8 pages, 4 figures, Published version in PRD
Phys. Rev. D 105 (2022) 9, 096008
10.1103/PhysRevD.105.096008
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Four next-to-tribimaximal (NTBM) mixing patterns are widely considered as the feasible candidates for the observed leptonic mixing structure. With the recent measurements from T2K, as well as intensive global fits, the interval of $\sin\delta_{ CP} > 0$ for the Dirac CP-violating phase is persistently small in the normal ordering while $\sin\delta_{ CP} < 0$ is successively obtained up to $3\sigma$ level in the inverted ordering. In this paper, we advocate the fitting results of Dirac CP-violating phase as a constraint, and show that, it can basically rule out half of the regions allowed by the constraint from three mixing angles only. In addition, given the small $\sin\delta_{ CP} > 0$ interval, we find that a unique NTBM pattern can be selected out of the four candidates within $3\sigma$ uncertainty of the latest NuFIT 5.1, when the patterns are exposed to a Yukawa texture-independent leptogenesis for the baryon asymmetry of the Universe. For the surviving pattern, we find an interesting correlation between the Dirac CP-violating phase and the octant of atmospheric angle $\theta_{23}$ , where $\theta_{23}>45^\circ$ can be predicted once $5\pi/6 < \delta_{CP} <\pi$ in the normal ordering can be confirmed in the future measurements.
[ { "created": "Thu, 13 Jan 2022 13:22:07 GMT", "version": "v1" }, { "created": "Wed, 11 May 2022 07:03:49 GMT", "version": "v2" }, { "created": "Tue, 17 May 2022 03:42:21 GMT", "version": "v3" } ]
2022-05-18
[ [ "Li", "Shao-Ping", "" ], [ "Yuan-Yuan-Li", "", "" ], [ "Yan", "Xin-Shuai", "" ], [ "Zhang", "Xin", "" ] ]
Four next-to-tribimaximal (NTBM) mixing patterns are widely considered as the feasible candidates for the observed leptonic mixing structure. With the recent measurements from T2K, as well as intensive global fits, the interval of $\sin\delta_{ CP} > 0$ for the Dirac CP-violating phase is persistently small in the normal ordering while $\sin\delta_{ CP} < 0$ is successively obtained up to $3\sigma$ level in the inverted ordering. In this paper, we advocate the fitting results of Dirac CP-violating phase as a constraint, and show that, it can basically rule out half of the regions allowed by the constraint from three mixing angles only. In addition, given the small $\sin\delta_{ CP} > 0$ interval, we find that a unique NTBM pattern can be selected out of the four candidates within $3\sigma$ uncertainty of the latest NuFIT 5.1, when the patterns are exposed to a Yukawa texture-independent leptogenesis for the baryon asymmetry of the Universe. For the surviving pattern, we find an interesting correlation between the Dirac CP-violating phase and the octant of atmospheric angle $\theta_{23}$ , where $\theta_{23}>45^\circ$ can be predicted once $5\pi/6 < \delta_{CP} <\pi$ in the normal ordering can be confirmed in the future measurements.
1310.4657
Mahatsab Mandal
Mahatsab Mandal and Pradip Roy
Wake in anisotropic Quark-Gluon Plasma
11 pages, 4 figures
Phys. Rev. D 86, 114002 (2012)
10.1103/PhysRevD.86.114002
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the wake in charge density and the wake potential due to the passage of a fast parton in an anisotropic quark gluon plasma(AQGP). For the sake of simplicity small $\xi$(anisotropic parameter) limit has been considered. When the velocity($v$) of the jet is parallel to the anisotropy direction(${\hat n}$) and remains below the phase velocity($v_p$), the wake in induced charge density shows a little oscillatory behavior in AQGP, contrary to the isotropic case. With the jet velocity greater than the phase velocity, the oscillatory behavior increases with $\xi$. Also for $v>v_p$ one observes a clear modification of the cone-like structure in presence of anisotropy. For the parallel direction in the backward region, the depth of the wake potential decreases with the increase of $\xi$ for $v<v_p$ and the potential becomes modified Coulomb-like for higher values of $\xi$. In the forward region, the potential remains modified Coulomb-like with the change in magnitude for nonzero $\xi$, for both $v>v_p$ and $v<v_p$. In the perpendicular direction, the wake potential is symmetric in the forward and backward regions. With the increase of $\xi$, the depth of negative minimum is moving away from the origin irrespective of the jet velocity. On the other hand when the jet velocity is perpendicular to the anisotropy direction, we find significant changes in the case of both wake charge density and potential in comparison to the isotropic case.
[ { "created": "Thu, 17 Oct 2013 11:22:51 GMT", "version": "v1" } ]
2013-10-18
[ [ "Mandal", "Mahatsab", "" ], [ "Roy", "Pradip", "" ] ]
We calculate the wake in charge density and the wake potential due to the passage of a fast parton in an anisotropic quark gluon plasma(AQGP). For the sake of simplicity small $\xi$(anisotropic parameter) limit has been considered. When the velocity($v$) of the jet is parallel to the anisotropy direction(${\hat n}$) and remains below the phase velocity($v_p$), the wake in induced charge density shows a little oscillatory behavior in AQGP, contrary to the isotropic case. With the jet velocity greater than the phase velocity, the oscillatory behavior increases with $\xi$. Also for $v>v_p$ one observes a clear modification of the cone-like structure in presence of anisotropy. For the parallel direction in the backward region, the depth of the wake potential decreases with the increase of $\xi$ for $v<v_p$ and the potential becomes modified Coulomb-like for higher values of $\xi$. In the forward region, the potential remains modified Coulomb-like with the change in magnitude for nonzero $\xi$, for both $v>v_p$ and $v<v_p$. In the perpendicular direction, the wake potential is symmetric in the forward and backward regions. With the increase of $\xi$, the depth of negative minimum is moving away from the origin irrespective of the jet velocity. On the other hand when the jet velocity is perpendicular to the anisotropy direction, we find significant changes in the case of both wake charge density and potential in comparison to the isotropic case.
hep-ph/9803472
Jose Maria Martinez Resco
J.M. Martinez Resco and M.A. Valle Basagoiti
The speed of cool soft pions
10 pages, 2 figures.A few typos corrected,some comments added.Version to be published in Phys. Rev. D
Phys. Rev. D 58, 097901 (1998)
10.1103/PhysRevD.58.097901
EHU-FT/9803
hep-ph
null
The speed of cool pions in the chiral limit is analytically computed at low temperature within the imaginary time formalism to two loop order. This evaluation shows a logarithmic dependence in the temperature where the scale within the logarithm is very large compared to the pion decay constant.
[ { "created": "Fri, 27 Mar 1998 10:04:21 GMT", "version": "v1" }, { "created": "Fri, 19 Jun 1998 07:59:30 GMT", "version": "v2" } ]
2016-08-25
[ [ "Resco", "J. M. Martinez", "" ], [ "Basagoiti", "M. A. Valle", "" ] ]
The speed of cool pions in the chiral limit is analytically computed at low temperature within the imaginary time formalism to two loop order. This evaluation shows a logarithmic dependence in the temperature where the scale within the logarithm is very large compared to the pion decay constant.
hep-ph/0012117
Davor Horvatic
Dubravko Horvat, Davor Horvati\'c, Boris Podobnik, Dubravko Tadi\'c (University of Zagreb)
The Extended Chiral Quark Model in a Tamm-Dancoff Inspired Approximation
14 pages, LaTeX
Fizika B9:181-196,2000
null
null
hep-ph
null
A procedure inspired by the Tamm-Dancoff method is applied to the chiral quark model which has been extended to include additional degrees of freedom: a pseudoscalar isoscalar field as well as a triplet of scalar isovector fields. The simpler, generic $\sigma$ -- model has been used before as a test for the Tamm-Dancoff inspired approximation (TDIA). The extended chirial quark model is employed here to investigate possible novel effects of the additional degrees of freedom as well as to point out the necessesity to introduce a SU(3) flavour. Model predictions for the axial-vector coupling constant and for the nucleon magnetic moment obtained in TDIA are compared with experimental values.
[ { "created": "Mon, 11 Dec 2000 15:04:06 GMT", "version": "v1" } ]
2016-08-15
[ [ "Horvat", "Dubravko", "", "University of Zagreb" ], [ "Horvatić", "Davor", "", "University of Zagreb" ], [ "Podobnik", "Boris", "", "University of Zagreb" ], [ "Tadić", "Dubravko", "", "University of Zagreb" ] ]
A procedure inspired by the Tamm-Dancoff method is applied to the chiral quark model which has been extended to include additional degrees of freedom: a pseudoscalar isoscalar field as well as a triplet of scalar isovector fields. The simpler, generic $\sigma$ -- model has been used before as a test for the Tamm-Dancoff inspired approximation (TDIA). The extended chirial quark model is employed here to investigate possible novel effects of the additional degrees of freedom as well as to point out the necessesity to introduce a SU(3) flavour. Model predictions for the axial-vector coupling constant and for the nucleon magnetic moment obtained in TDIA are compared with experimental values.
1301.6253
Wei-Min Yang
Wei-Min Yang
A Model of Four Generation Fermions and Cold Dark Matter and Matter-Antimatter Asymmetry
22 pages, 6 figures, some small corrections. arXiv admin note: substantial text overlap with arXiv:1301.0076, arXiv:1206.5353
null
10.1103/PhysRevD.87.095003
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I suggest a practical particle model as an extension to the standard model. The model has a TeV scale $U(1)_{B-L}$ symmetry and it contains the fourth generation fermions with the TeV scale masses, in which including a cold dark matter neutrino. The model can completely account for the fermion flavor puzzles, the cold dark matter, and the matter-antimatter asymmetry through the leptogenesis. In particular, it is quite feasible and promising to test the model in future experiments.
[ { "created": "Sat, 26 Jan 2013 13:34:59 GMT", "version": "v1" }, { "created": "Sun, 3 Feb 2013 05:40:42 GMT", "version": "v2" } ]
2013-05-15
[ [ "Yang", "Wei-Min", "" ] ]
I suggest a practical particle model as an extension to the standard model. The model has a TeV scale $U(1)_{B-L}$ symmetry and it contains the fourth generation fermions with the TeV scale masses, in which including a cold dark matter neutrino. The model can completely account for the fermion flavor puzzles, the cold dark matter, and the matter-antimatter asymmetry through the leptogenesis. In particular, it is quite feasible and promising to test the model in future experiments.
hep-ph/9902359
Victor Nikonov
V. V. Anisovich, L. G. Dakhno, D. I. Melikhov, V. A. Nikonov, and M. G. Ryskin
Pomeron in diffractive processes $\gamma^*(Q^2)p\to\rho^0 p$ and $\gamma^*(Q^2)p\to\gamma^*(Q^2) p$ at large Q^2: the onset of pQCD
20 pages, LaTeX, epsfig.sty
Phys. Rev. D 60, 074011 (1999)
10.1103/PhysRevD.60.074011
null
hep-ph
null
We study the reactions $\gamma^*(Q^2)p\to\rho^0 p$ and $\gamma^*(Q^2)p\to\gamma^*(Q^2) p$ at large Q^2 and $W^2/Q^2$ and small momentum transfer, $\kappa^2_\perp$, to the nucleon where the pomeron exchange dominates. At large Q^2 the virtual photon selects a hard $q\bar q$ pair, thus selecting the hard pomeron component (the BFKL pomeron). The amplitudes for both transverse and longitudinal polarizations of the initial photon and outgoing $\rho$-meson (photon) are calculated in the framework of the BFKL pomeron exchange. Our calculations show that one cannot expect the early onset of the pure perturbative regime in the discussed diffractive processes: the small interquark distances, $\rho_{q\bar q} <0.2$ fm, start to dominate not earlier than at $Q^2 \simeq 100 GeV^2, W^2/Q^2 \simeq 10^7$ in $\gamma^*(Q^2)p\to\rho^0 p$ and $Q^2 \simeq 50 GeV^2, W^2/Q^2 \simeq 10^6$ in $\gamma^*(Q^2)p\to\gamma^*(Q^2) p$.
[ { "created": "Tue, 16 Feb 1999 09:50:23 GMT", "version": "v1" } ]
2016-08-25
[ [ "Anisovich", "V. V.", "" ], [ "Dakhno", "L. G.", "" ], [ "Melikhov", "D. I.", "" ], [ "Nikonov", "V. A.", "" ], [ "Ryskin", "M. G.", "" ] ]
We study the reactions $\gamma^*(Q^2)p\to\rho^0 p$ and $\gamma^*(Q^2)p\to\gamma^*(Q^2) p$ at large Q^2 and $W^2/Q^2$ and small momentum transfer, $\kappa^2_\perp$, to the nucleon where the pomeron exchange dominates. At large Q^2 the virtual photon selects a hard $q\bar q$ pair, thus selecting the hard pomeron component (the BFKL pomeron). The amplitudes for both transverse and longitudinal polarizations of the initial photon and outgoing $\rho$-meson (photon) are calculated in the framework of the BFKL pomeron exchange. Our calculations show that one cannot expect the early onset of the pure perturbative regime in the discussed diffractive processes: the small interquark distances, $\rho_{q\bar q} <0.2$ fm, start to dominate not earlier than at $Q^2 \simeq 100 GeV^2, W^2/Q^2 \simeq 10^7$ in $\gamma^*(Q^2)p\to\rho^0 p$ and $Q^2 \simeq 50 GeV^2, W^2/Q^2 \simeq 10^6$ in $\gamma^*(Q^2)p\to\gamma^*(Q^2) p$.
1801.06777
Mosleh Almarashi
M. Almarashi
Discovery potential of the NMSSM CP-odd Higgs at the LHC
12 pages, 21 figures
Results Phys. 10 (2018) 799
10.1016/j.rinp.2018.07.036
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we examine the LHC discovery potential of the lightest CP-odd Higgs boson, a1, of the NMSSM produced in gluon fusion channel gg->a1. We evaluate the inclusive signal rates of the a1 for a variety of decay channels and discuss its possible discovery. It is observed that the overall production and decay rates at inclusive level are quite sizable and should help extracting the a1 signal over some regions of the NMSSM parameter space.
[ { "created": "Sun, 21 Jan 2018 06:47:22 GMT", "version": "v1" } ]
2018-08-10
[ [ "Almarashi", "M.", "" ] ]
In this paper we examine the LHC discovery potential of the lightest CP-odd Higgs boson, a1, of the NMSSM produced in gluon fusion channel gg->a1. We evaluate the inclusive signal rates of the a1 for a variety of decay channels and discuss its possible discovery. It is observed that the overall production and decay rates at inclusive level are quite sizable and should help extracting the a1 signal over some regions of the NMSSM parameter space.
2207.08067
Luca Visinelli
Gaetano Lambiase, Leonardo Mastrototaro, Luca Visinelli
Gravitational waves and neutrino oscillations in Chern-Simons axion gravity
28 pages, 3 figures. Matches the version published on JCAP
JCAP 2301, 011 (2023)
10.1088/1475-7516/2023/01/011
null
hep-ph astro-ph.CO astro-ph.GA gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the modifications in the neutrino flavor oscillations under the influence of a stochastic gravitational wave background (SGWB), in a scenario in which General Relativity is modified by an additional Chern-Simons (CS) term. Assuming that the dark matter halo is in the form of axions, the CS coupling modifies the pattern of the neutrino flavor oscillations at Earth up to a total suppression in some frequency range. At the same time, the SGWB in the halo could stimulate the axion decay into gravitons over a narrow frequency range, leading to a potentially detectable resonance peak in the enhanced SGWB strain. A consistent picture would require these features to potentially show up in neutrino detection from supernovae, gravitational wave detectors, and experiments aimed at the search for axions in the Milky Way halo.
[ { "created": "Sun, 17 Jul 2022 03:35:13 GMT", "version": "v1" }, { "created": "Fri, 13 Jan 2023 18:44:13 GMT", "version": "v2" } ]
2023-01-16
[ [ "Lambiase", "Gaetano", "" ], [ "Mastrototaro", "Leonardo", "" ], [ "Visinelli", "Luca", "" ] ]
We investigate the modifications in the neutrino flavor oscillations under the influence of a stochastic gravitational wave background (SGWB), in a scenario in which General Relativity is modified by an additional Chern-Simons (CS) term. Assuming that the dark matter halo is in the form of axions, the CS coupling modifies the pattern of the neutrino flavor oscillations at Earth up to a total suppression in some frequency range. At the same time, the SGWB in the halo could stimulate the axion decay into gravitons over a narrow frequency range, leading to a potentially detectable resonance peak in the enhanced SGWB strain. A consistent picture would require these features to potentially show up in neutrino detection from supernovae, gravitational wave detectors, and experiments aimed at the search for axions in the Milky Way halo.
2302.11126
Nicholas Hunt-Smith
N. T. Hunt-Smith, W. Melnitchouk, N. Sato, A. W. Thomas, X. G. Wang, M. J. White
Global QCD Analysis and Dark Photons
15 pages, 6 figures, 1 table
null
null
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform a global QCD analysis of high energy scattering data within the JAM Monte Carlo framework, including a coupling to a dark photon that augments the standard model electroweak coupling via kinetic mixing with the hypercharge $B$ boson. Including the most recent measurement of the anomalous magnetic moment of the muon as a constraint, we find a significant reduction in the combined $\chi^2$, favoring the inclusion of a dark photon, with a statistical significance in excess of 8$\sigma$. With respect to the experimental data, the improvements in the theoretical predictions are spread across a wide range of $x$ and $Q^2$, with the largest improvement corresponding to neutral current data from HERA, while the best fit yields a value of $g-2$ which significantly reduces the disagreement with the latest experimental determination. The best fit yields a dark photon mass in the range 4.2--6.2 GeV and a mixing parameter of order 0.1.
[ { "created": "Wed, 22 Feb 2023 03:41:41 GMT", "version": "v1" }, { "created": "Fri, 25 Aug 2023 01:57:31 GMT", "version": "v2" } ]
2023-08-28
[ [ "Hunt-Smith", "N. T.", "" ], [ "Melnitchouk", "W.", "" ], [ "Sato", "N.", "" ], [ "Thomas", "A. W.", "" ], [ "Wang", "X. G.", "" ], [ "White", "M. J.", "" ] ]
We perform a global QCD analysis of high energy scattering data within the JAM Monte Carlo framework, including a coupling to a dark photon that augments the standard model electroweak coupling via kinetic mixing with the hypercharge $B$ boson. Including the most recent measurement of the anomalous magnetic moment of the muon as a constraint, we find a significant reduction in the combined $\chi^2$, favoring the inclusion of a dark photon, with a statistical significance in excess of 8$\sigma$. With respect to the experimental data, the improvements in the theoretical predictions are spread across a wide range of $x$ and $Q^2$, with the largest improvement corresponding to neutral current data from HERA, while the best fit yields a value of $g-2$ which significantly reduces the disagreement with the latest experimental determination. The best fit yields a dark photon mass in the range 4.2--6.2 GeV and a mixing parameter of order 0.1.
1406.2994
Francesco Hautmann
S. Dooling, F. Hautmann and H. Jung
Hadroproduction of electroweak gauge boson plus jets and TMD parton density functions
9 pages, 4 figures. v2: comments and references added, typos corrected; results unchanged
null
10.1016/j.physletb.2014.07.035
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
If studies of electroweak gauge boson final states at the Large Hadron Collider, for Standard Model physics and beyond, are sensitive to effects of the initial state's transverse momentum distribution, appropriate generalizations of QCD shower evolution are required. We propose a method to do this based on QCD transverse momentum dependent (TMD) factorization at high energy. The method incorporates experimental information from the high-precision deep inelastic scattering (DIS) measurements, and includes experimental and theoretical uncertainties on TMD parton density functions. We illustrate the approach presenting results for production of W-boson + n jets at the LHC, including azimuthal correlations and subleading jet distributions.
[ { "created": "Wed, 11 Jun 2014 19:08:43 GMT", "version": "v1" }, { "created": "Thu, 31 Jul 2014 20:56:25 GMT", "version": "v2" } ]
2015-06-19
[ [ "Dooling", "S.", "" ], [ "Hautmann", "F.", "" ], [ "Jung", "H.", "" ] ]
If studies of electroweak gauge boson final states at the Large Hadron Collider, for Standard Model physics and beyond, are sensitive to effects of the initial state's transverse momentum distribution, appropriate generalizations of QCD shower evolution are required. We propose a method to do this based on QCD transverse momentum dependent (TMD) factorization at high energy. The method incorporates experimental information from the high-precision deep inelastic scattering (DIS) measurements, and includes experimental and theoretical uncertainties on TMD parton density functions. We illustrate the approach presenting results for production of W-boson + n jets at the LHC, including azimuthal correlations and subleading jet distributions.
hep-ph/9807369
Andreas Vogt
Andreas Vogt (W"urzburg Univ.)
DIS'98 Structure Functions Summary, Part II
9 pages Latex including 5 figures (9 eps-files), uses sprocl.sty. Talk presented at DIS'98, Brussels, April 1998. To appear in the proceedings
null
null
WUE-ITP-98-031
hep-ph
null
Recent results presented in the structure functions working group are briefly summarized for the following topics: The theoretical treatment of heavy quarks in structure functions, higher-order corrections for the leading-twist evolution (including small-x resummations), the present status of the proton's parton densities, and the impact of higher twists on determinations of the strong coupling constant. The reader is referred to Part I for accounts of the transition to the photoproduction region, pion and photon structure results, and high-Q^2 phenomena.
[ { "created": "Tue, 14 Jul 1998 14:49:04 GMT", "version": "v1" } ]
2007-05-23
[ [ "Vogt", "Andreas", "", "W\"urzburg Univ." ] ]
Recent results presented in the structure functions working group are briefly summarized for the following topics: The theoretical treatment of heavy quarks in structure functions, higher-order corrections for the leading-twist evolution (including small-x resummations), the present status of the proton's parton densities, and the impact of higher twists on determinations of the strong coupling constant. The reader is referred to Part I for accounts of the transition to the photoproduction region, pion and photon structure results, and high-Q^2 phenomena.
hep-ph/9311282
Andreas Blumhofer
Andreas Blumhofer
Top Condensation without Fine-Tuning
LMU - 17/93, in LATEX, 12 pages and 3 pages of figures appended in Postscript
Phys.Lett. B320 (1994) 352-358
10.1016/0370-2693(94)90668-8
null
hep-ph
null
Quadratic divergencies which lead to the usual fine-tuning or hierarchy problem are discussed in top condensation models. As in the Standard Model a cancellation of quadratic divergencies is not possible without the boson contributions in the radiative corrections which are absent in lowest order of an $1/N_c$-expansion. To deal with the cancellation of quadratic divergencies we propose therefore an expansion in the flavor degrees of freedom. In leading order we find the remarkable result that quadratic divergencies automatically disappear.
[ { "created": "Fri, 12 Nov 1993 15:23:32 GMT", "version": "v1" } ]
2009-10-22
[ [ "Blumhofer", "Andreas", "" ] ]
Quadratic divergencies which lead to the usual fine-tuning or hierarchy problem are discussed in top condensation models. As in the Standard Model a cancellation of quadratic divergencies is not possible without the boson contributions in the radiative corrections which are absent in lowest order of an $1/N_c$-expansion. To deal with the cancellation of quadratic divergencies we propose therefore an expansion in the flavor degrees of freedom. In leading order we find the remarkable result that quadratic divergencies automatically disappear.
hep-ph/0409001
Hyung Do Kim
Hyung Do Kim, Jihn E. Kim and Takuya Morozumi
A New Mechanism For Baryogenesis Living Through Electroweak Era
10 pages, typos corrected, the washout rate by sphaleron corrected and new bound from the decay using 4 fermi interaction added
Phys.Lett. B616 (2005) 108-113
10.1016/j.physletb.2005.04.056
SNUTP 04-014
hep-ph astro-ph
null
We present a new mechanism for baryogenesis by introducing a heavy vector-like SU(2)_W singlet quark(s) with Q_{em}=2/3 quark U or Q_{em}=-1/3 quark D. The lifetime of the heavy quark is assumed to be in the range 2 \times 10^{-11}s < t < 1s. Being SU(2)_W singlet, it survives the electroweak phase transition era. It mixes with SU(2)_W doublet quarks with tiny mixing angles to satisfy the FCNC constraints, where a simple Z_2 symmetry is suggested for realizing this scheme. The heavy quark asymmetry is generated in analogy with the old GUT scenario.
[ { "created": "Wed, 1 Sep 2004 06:46:26 GMT", "version": "v1" }, { "created": "Thu, 4 Nov 2004 04:18:03 GMT", "version": "v2" } ]
2009-11-10
[ [ "Kim", "Hyung Do", "" ], [ "Kim", "Jihn E.", "" ], [ "Morozumi", "Takuya", "" ] ]
We present a new mechanism for baryogenesis by introducing a heavy vector-like SU(2)_W singlet quark(s) with Q_{em}=2/3 quark U or Q_{em}=-1/3 quark D. The lifetime of the heavy quark is assumed to be in the range 2 \times 10^{-11}s < t < 1s. Being SU(2)_W singlet, it survives the electroweak phase transition era. It mixes with SU(2)_W doublet quarks with tiny mixing angles to satisfy the FCNC constraints, where a simple Z_2 symmetry is suggested for realizing this scheme. The heavy quark asymmetry is generated in analogy with the old GUT scenario.
1001.3733
Mitsuo J. Hayashi
Yuta Koshimizu, Toyokazu Fukuoka, Kenji Takagi, Hikoya Kasari, Mitsuo J. Hayashi
Reheating Temperature after Inflation in No-Scale Supergravity
9 pages
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
By using a No-Scale Supergravity model, which was proved well to explain WMAP observations appropriately, a mechanism of preheating just after the end of inflation is investigated. By using the canonically normalized and diagonalized scalars, the decay rates of these fields are calculated inflaton $S$ into gauge sector fields. The reheating temperature is estimated by both the stability condition of Boltzmann equation and the instant preheating mechanism. The both of reheating temperatures are almost the same order of magnitude $\sim O(10^{10})$ GeV. Because two mechanisms are completely independent processes, the former is caused through the inflaton decays into gauge fields and gauginons and the latter is caused by the scattering process of two inflatons into two right handed sneutrinos, which will decay into Higgs fields and other minimal SUSY standard model (MSSM) particles, we conclude that both mechanisms play essential roles in the preheating process after inflation.
[ { "created": "Thu, 21 Jan 2010 06:53:39 GMT", "version": "v1" }, { "created": "Fri, 29 Jan 2010 04:41:08 GMT", "version": "v2" }, { "created": "Wed, 3 Mar 2010 06:42:11 GMT", "version": "v3" } ]
2010-03-03
[ [ "Koshimizu", "Yuta", "" ], [ "Fukuoka", "Toyokazu", "" ], [ "Takagi", "Kenji", "" ], [ "Kasari", "Hikoya", "" ], [ "Hayashi", "Mitsuo J.", "" ] ]
By using a No-Scale Supergravity model, which was proved well to explain WMAP observations appropriately, a mechanism of preheating just after the end of inflation is investigated. By using the canonically normalized and diagonalized scalars, the decay rates of these fields are calculated inflaton $S$ into gauge sector fields. The reheating temperature is estimated by both the stability condition of Boltzmann equation and the instant preheating mechanism. The both of reheating temperatures are almost the same order of magnitude $\sim O(10^{10})$ GeV. Because two mechanisms are completely independent processes, the former is caused through the inflaton decays into gauge fields and gauginons and the latter is caused by the scattering process of two inflatons into two right handed sneutrinos, which will decay into Higgs fields and other minimal SUSY standard model (MSSM) particles, we conclude that both mechanisms play essential roles in the preheating process after inflation.
hep-ph/0211193
Sven-Olaf Moch
S. Moch
Sudakov Logarithms in Four-Fermion Electroweak Processes at High Energy
Talk at RADCOR 2002, Kloster Banz, Germany, 8-13 Sep 2002; 5 pages, 1 figure
Nucl.Phys.Proc.Suppl. 116 (2003) 23-27
10.1016/S0920-5632(03)80137-8
null
hep-ph
null
We discuss recent results for the asymptotic behavior of fermion scattering amplitudes in the Sudakov limit. The results include next-to-next-to-leading logarithmic electroweak corrections and are used for the analysis of fermion-antifermion pair production in e+e- annihilation at high energy. The importance of the subleading logarithmic contributions is emphasized and the fermionic contributions to the Abelian form factor at two loops are discussed.
[ { "created": "Wed, 13 Nov 2002 08:32:46 GMT", "version": "v1" } ]
2009-11-07
[ [ "Moch", "S.", "" ] ]
We discuss recent results for the asymptotic behavior of fermion scattering amplitudes in the Sudakov limit. The results include next-to-next-to-leading logarithmic electroweak corrections and are used for the analysis of fermion-antifermion pair production in e+e- annihilation at high energy. The importance of the subleading logarithmic contributions is emphasized and the fermionic contributions to the Abelian form factor at two loops are discussed.
hep-ph/0501233
Cristina Volpe
Cristina Volpe (Institut de Physique Nucleaire Orsay, France)
Neutrino-nucleus interactions as a probe to constrain double-beta decay predictions
4 pages, 4 figures
J.Phys.G31:903-908,2005
10.1088/0954-3899/31/8/019
null
hep-ph hep-ex nucl-ex nucl-th
null
We propose to use charged-current neutrino-nucleus interactions as a probe of the many virtual transitions involved in neutrinoless double-beta decay. By performing neutrino and anti-neutrino interaction studies on the initial and final nucleus respectively, one can get information on the two branches involved in the double-beta decay process. The measurement of such reactions could help to further constrain double-beta decay predictions on the half-lives.
[ { "created": "Tue, 25 Jan 2005 18:40:38 GMT", "version": "v1" } ]
2011-08-23
[ [ "Volpe", "Cristina", "", "Institut de Physique Nucleaire Orsay, France" ] ]
We propose to use charged-current neutrino-nucleus interactions as a probe of the many virtual transitions involved in neutrinoless double-beta decay. By performing neutrino and anti-neutrino interaction studies on the initial and final nucleus respectively, one can get information on the two branches involved in the double-beta decay process. The measurement of such reactions could help to further constrain double-beta decay predictions on the half-lives.
hep-ph/0609280
Andrey Grozin
A.G. Grozin, A.V. Smirnov, V.A. Smirnov
Decoupling of heavy quarks in HQET
JHEP3 documentclass; the results in a computer-readable form can be found at http://www-ttp.physik.uni-karlsruhe.de/Progdata/ttp06/ttp06-25/ V2: a few typos corrected, a few minor text improvements, a few references added; V3: several typos in formulas fixed
JHEP0611:022,2006
10.1088/1126-6708/2006/11/022
TTP06-25
hep-ph
null
Decoupling of c-quark loops in b-quark HQET is considered. The decoupling coefficients for the HQET heavy-quark field and the heavy-light quark current are calculated with the three-loop accuracy. The last result can be used to improve the accuracy of extracting f_B from HQET lattice simulations (without c-quark loops). The decoupling coefficient for the flavour-nonsinglet QCD current with n antisymmetrized gamma-matrices is also obtained at three loops; the result for the tensor current (n=2) is new.
[ { "created": "Wed, 27 Sep 2006 12:37:52 GMT", "version": "v1" }, { "created": "Fri, 20 Oct 2006 12:50:51 GMT", "version": "v2" }, { "created": "Thu, 8 Mar 2007 01:28:01 GMT", "version": "v3" } ]
2009-11-11
[ [ "Grozin", "A. G.", "" ], [ "Smirnov", "A. V.", "" ], [ "Smirnov", "V. A.", "" ] ]
Decoupling of c-quark loops in b-quark HQET is considered. The decoupling coefficients for the HQET heavy-quark field and the heavy-light quark current are calculated with the three-loop accuracy. The last result can be used to improve the accuracy of extracting f_B from HQET lattice simulations (without c-quark loops). The decoupling coefficient for the flavour-nonsinglet QCD current with n antisymmetrized gamma-matrices is also obtained at three loops; the result for the tensor current (n=2) is new.