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1811.03655
Edward Shuryak
Adith Ramamurti and Edward Shuryak
Extending the hydrodynamical description of heavy-ion collisions to the "outer edge" of the fireball
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is well known that relativistic hydrodynamics provides very good description of heavy-ion collisions at RHIC/LHC energies up to transverse momenta $p_\perp\sim 2\, \text{GeV}$. In this paper, we suggest that this description can be extended to higher $p_\perp\sim 6\, \text{GeV}$, beyond which hard collisions contribute. While most previous work focused on a part of the freezeout surface at the latest proper time (referred to in this work as the "lid"), we focus on the complementary part, to be referred as "the outer edge," where the highest transverse rapidity of flow $\kappa\sim 1.4$ is achieved. We study this surface analytically, using the Riemann rarefaction wave, and numerically, using MUSIC numerical hydrodynamic code. We also use an improved freezeout condition, where the collision rate equals the expansion rate. For central collisions, we observe good description of spectra for $\pi,K,N$ in central PbPb LHC collisions in this extended region. We further suggest that "the outer edge" has very small azimuthal asymmetry even for non-central collisions, smaller than predicted by standard hydrodynamics.
[ { "created": "Thu, 8 Nov 2018 19:23:38 GMT", "version": "v1" } ]
2018-11-12
[ [ "Ramamurti", "Adith", "" ], [ "Shuryak", "Edward", "" ] ]
It is well known that relativistic hydrodynamics provides very good description of heavy-ion collisions at RHIC/LHC energies up to transverse momenta $p_\perp\sim 2\, \text{GeV}$. In this paper, we suggest that this description can be extended to higher $p_\perp\sim 6\, \text{GeV}$, beyond which hard collisions contribute. While most previous work focused on a part of the freezeout surface at the latest proper time (referred to in this work as the "lid"), we focus on the complementary part, to be referred as "the outer edge," where the highest transverse rapidity of flow $\kappa\sim 1.4$ is achieved. We study this surface analytically, using the Riemann rarefaction wave, and numerically, using MUSIC numerical hydrodynamic code. We also use an improved freezeout condition, where the collision rate equals the expansion rate. For central collisions, we observe good description of spectra for $\pi,K,N$ in central PbPb LHC collisions in this extended region. We further suggest that "the outer edge" has very small azimuthal asymmetry even for non-central collisions, smaller than predicted by standard hydrodynamics.
0903.4922
Guy F. de T\'eramond
Guy F. de Teramond and Stanley J. Brodsky
Light Front Holography: Response to a Comment by L. Glozman
2 pages
null
null
SLAC-PUB-13422
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We reply to L. Ya. Glozman's Comment "Is a consistent holographic description of excited hadrons with fixed $L$ possible?" In general, the solutions of the bound state Hamiltonian equation of motion in QCD have Fock state components with different $L$, and consequently hadronic relativistic wave equations derived in the framework of light-front holography share this property. For example, the proton eigenstate has components with L=0 and L=1. The results of AdS/QCD are consistent with the requirements of chiral symmetry and do not violate any fundamental physical principle. This is further illustrated with various examples.
[ { "created": "Sat, 28 Mar 2009 17:58:27 GMT", "version": "v1" } ]
2009-04-01
[ [ "de Teramond", "Guy F.", "" ], [ "Brodsky", "Stanley J.", "" ] ]
We reply to L. Ya. Glozman's Comment "Is a consistent holographic description of excited hadrons with fixed $L$ possible?" In general, the solutions of the bound state Hamiltonian equation of motion in QCD have Fock state components with different $L$, and consequently hadronic relativistic wave equations derived in the framework of light-front holography share this property. For example, the proton eigenstate has components with L=0 and L=1. The results of AdS/QCD are consistent with the requirements of chiral symmetry and do not violate any fundamental physical principle. This is further illustrated with various examples.
hep-ph/9809304
Utpal Sarkar
Utpal Sarkar and R. Vaidya
CP violation in the mass matrix of heavy neutrinos
9 pages latex file, minor changes
Phys.Lett. B442 (1998) 243-248
10.1016/S0370-2693(98)01286-6
DESY 98-133
hep-ph
null
We discuss the question of CP-violation in the effective Hamiltonian approach in models of leptogenesis through heavy right handed neutrino decays. We first formulate the problem in four component notation and then point out that before the heavy neutrinos have decayed away, the universe becomes CP-asymmetric in the heavy neutrinos. However, the lepton asymmetry generated after they completely decay are independent of this asymmetry.
[ { "created": "Tue, 8 Sep 1998 18:24:09 GMT", "version": "v1" }, { "created": "Thu, 15 Oct 1998 11:37:48 GMT", "version": "v2" } ]
2009-10-31
[ [ "Sarkar", "Utpal", "" ], [ "Vaidya", "R.", "" ] ]
We discuss the question of CP-violation in the effective Hamiltonian approach in models of leptogenesis through heavy right handed neutrino decays. We first formulate the problem in four component notation and then point out that before the heavy neutrinos have decayed away, the universe becomes CP-asymmetric in the heavy neutrinos. However, the lepton asymmetry generated after they completely decay are independent of this asymmetry.
1611.05879
Yuhsin Tsai
Valentina Prilepina, Yuhsin Tsai
Reconciling Large And Small-Scale Structure In Twin Higgs Models
22 pages, 5 figures; version accepted for publication in JHEP; include discussion of twin hydrogen DM
null
10.1007/JHEP09(2017)033
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study extensions of the Twin Higgs model that solve the Hierarchy problem and simultaneously address problems of the large- and small-scale structures of the Universe. Besides naturally providing dark matter (DM) candidates as the lightest charged twin fermions, the twin sector contains a light photon and neutrinos, which can modify structure formation relative to the prediction from the $\Lambda$CDM paradigm. We focus on two scenarios. First, we study a Fraternal Twin Higgs model in which the spin-3/2 baryon $\hat{\Omega}\sim(\hat{b}\hat{b}\hat{b})$ and the lepton twin tau $\hat{\tau}$ contribute to the dominant and subcomponent dark matter densities. A non-decoupled scattering between the twin tau and twin neutrino arising from a gauged twin lepton number symmetry provides a drag force that damps the density inhomogeneity of a dark matter subcomponent. Next, we consider the possibility of having the twin hydrogen atom $\hat{H}$ as the dominant DM component. After recombination, a small fraction of the twin protons and leptons remains ionized during structure formation, and their scattering to twin neutrinos through a gauged U$(1)_{B-L}$ force provides the mechanism that damps the density inhomogeneity. Both scenarios realize the Partially Acoustic dark matter (PAcDM) scenario and explain the $\sigma_8$ discrepancy between the CMB and weak lensing results. Moreover, the self-scattering neutrino behaves as a dark fluid that enhances the size of the Hubble rate $H_0$ to accommodate the local measurement result while satisfying the CMB constraint. For the small-scale structure, the scattering of $\hat{\Omega}$'s and $\hat{H}$'s through the twin photon exchange generates a self-interacting dark matter (SIDM) model that solves the mass deficit problem from dwarf galaxy to galaxy cluster scales.
[ { "created": "Thu, 17 Nov 2016 21:00:08 GMT", "version": "v1" }, { "created": "Wed, 9 Aug 2017 17:05:09 GMT", "version": "v2" } ]
2017-10-11
[ [ "Prilepina", "Valentina", "" ], [ "Tsai", "Yuhsin", "" ] ]
We study extensions of the Twin Higgs model that solve the Hierarchy problem and simultaneously address problems of the large- and small-scale structures of the Universe. Besides naturally providing dark matter (DM) candidates as the lightest charged twin fermions, the twin sector contains a light photon and neutrinos, which can modify structure formation relative to the prediction from the $\Lambda$CDM paradigm. We focus on two scenarios. First, we study a Fraternal Twin Higgs model in which the spin-3/2 baryon $\hat{\Omega}\sim(\hat{b}\hat{b}\hat{b})$ and the lepton twin tau $\hat{\tau}$ contribute to the dominant and subcomponent dark matter densities. A non-decoupled scattering between the twin tau and twin neutrino arising from a gauged twin lepton number symmetry provides a drag force that damps the density inhomogeneity of a dark matter subcomponent. Next, we consider the possibility of having the twin hydrogen atom $\hat{H}$ as the dominant DM component. After recombination, a small fraction of the twin protons and leptons remains ionized during structure formation, and their scattering to twin neutrinos through a gauged U$(1)_{B-L}$ force provides the mechanism that damps the density inhomogeneity. Both scenarios realize the Partially Acoustic dark matter (PAcDM) scenario and explain the $\sigma_8$ discrepancy between the CMB and weak lensing results. Moreover, the self-scattering neutrino behaves as a dark fluid that enhances the size of the Hubble rate $H_0$ to accommodate the local measurement result while satisfying the CMB constraint. For the small-scale structure, the scattering of $\hat{\Omega}$'s and $\hat{H}$'s through the twin photon exchange generates a self-interacting dark matter (SIDM) model that solves the mass deficit problem from dwarf galaxy to galaxy cluster scales.
0710.4955
Stephanie Trine
Stephanie Trine
The MSSM Higgs sector and B-Bbar mixing for large tan(beta)
Submitted for the SUSY07 proceedings, 4 pages, LaTeX, 4 eps figures
null
null
TTP07-31, SFB/CPP-07-73
hep-ph
null
A systematic analysis of Higgs-mediated contributions to the Bd and Bs mass differences is presented in the MSSM with large values of tan(beta). In particular, supersymmetric corrections to Higgs self-interactions are seen to modify the correlation between Delta Mq and BR(Bq --> mu+ mu-) for light Higgses. The present experimental upper bound on BR(Bs --> mu+ mu-) is nevertheless still sufficient to exclude noticeable Higgs-mediated effects on the mass differences in most of the parameter space.
[ { "created": "Fri, 26 Oct 2007 14:02:07 GMT", "version": "v1" } ]
2007-10-29
[ [ "Trine", "Stephanie", "" ] ]
A systematic analysis of Higgs-mediated contributions to the Bd and Bs mass differences is presented in the MSSM with large values of tan(beta). In particular, supersymmetric corrections to Higgs self-interactions are seen to modify the correlation between Delta Mq and BR(Bq --> mu+ mu-) for light Higgses. The present experimental upper bound on BR(Bs --> mu+ mu-) is nevertheless still sufficient to exclude noticeable Higgs-mediated effects on the mass differences in most of the parameter space.
hep-ph/0005113
Alfredo Aranda
Alfredo Aranda and Marc Sher (College of William and Mary)
Generations of Higgs Bosons in Supersymmetric Models
Substantial changes in the discussion of the scalar mass differences, due to a sign error in a Feynman rule. Version to appear in Physical Review D
Phys.Rev. D62 (2000) 092002
10.1103/PhysRevD.62.092002
WM-00-104
hep-ph
null
We examine extensions of the MSSM with more than one generation of Higgs bosons. If one assumes that a symmetry eliminates the tree-level FCNC, then the extra scalar bosons do not acquire VEVs, do not couple to fermions and do not mix with the ordinary Higgs bosons; the lightest is absolutely stable. The two lightest neutral scalars, $\phi_S$, and $\phi_P$, are degenerate in mass, and the mass difference between those and the lightest charged scalar, $\phi_+$, is calculated. For most of the parameter space, the charged scalar is between a hundred MeV and a few GeV heavier than the neutral scalars. The $\phi_+$ will decay at the vertex; the signature for this decay will be like that of a chargino with a nearly degenerate undetected neutralino. Next, the possibility that the symmetry that eliminates FCNC is a flavor symmetry is discussed. In an example, the U(2) model, tree-level FCNC processes can be calculated in terms of quark masses. The strongest constraint on this model is from $D-\bar{D}$ mixing, which should be within an order of magnitude of the current bound.
[ { "created": "Thu, 11 May 2000 19:31:51 GMT", "version": "v1" }, { "created": "Wed, 26 Jul 2000 14:18:39 GMT", "version": "v2" } ]
2009-10-31
[ [ "Aranda", "Alfredo", "", "College of William and Mary" ], [ "Sher", "Marc", "", "College of William and Mary" ] ]
We examine extensions of the MSSM with more than one generation of Higgs bosons. If one assumes that a symmetry eliminates the tree-level FCNC, then the extra scalar bosons do not acquire VEVs, do not couple to fermions and do not mix with the ordinary Higgs bosons; the lightest is absolutely stable. The two lightest neutral scalars, $\phi_S$, and $\phi_P$, are degenerate in mass, and the mass difference between those and the lightest charged scalar, $\phi_+$, is calculated. For most of the parameter space, the charged scalar is between a hundred MeV and a few GeV heavier than the neutral scalars. The $\phi_+$ will decay at the vertex; the signature for this decay will be like that of a chargino with a nearly degenerate undetected neutralino. Next, the possibility that the symmetry that eliminates FCNC is a flavor symmetry is discussed. In an example, the U(2) model, tree-level FCNC processes can be calculated in terms of quark masses. The strongest constraint on this model is from $D-\bar{D}$ mixing, which should be within an order of magnitude of the current bound.
hep-ph/0001237
johann Dischler
J. Dischler, T. Sj\"ostrand
A Model for the Colour Form Factor of the Proton
24 pages, 19 pictures
null
null
LU TP 00-01
hep-ph
null
The total cross-section and the jet cross-section differ at a proton-proton collision. The latter is divergent if arbitrarily small transverse momenta are allowed. Even with some fixed lower pt cutoff, increases the jet cross-section much faster than the total cross-section at high energies. We have in this paper studied how the divergence could be tamed by colour screening effects among the partons. To do this we have built a proton model where we assign momenta, positions and colour-charge to all partons in the proton. We find that the relative behaviour of the cross-section can be better understood by the inclusion of this effect.
[ { "created": "Mon, 24 Jan 2000 09:52:46 GMT", "version": "v1" } ]
2007-05-23
[ [ "Dischler", "J.", "" ], [ "Sjöstrand", "T.", "" ] ]
The total cross-section and the jet cross-section differ at a proton-proton collision. The latter is divergent if arbitrarily small transverse momenta are allowed. Even with some fixed lower pt cutoff, increases the jet cross-section much faster than the total cross-section at high energies. We have in this paper studied how the divergence could be tamed by colour screening effects among the partons. To do this we have built a proton model where we assign momenta, positions and colour-charge to all partons in the proton. We find that the relative behaviour of the cross-section can be better understood by the inclusion of this effect.
1309.3867
Thomas A. Ryttov
Thomas A. Ryttov
Higher Loop Corrections to the Infrared Evolution of Fermionic Gauge Theories in the RI' Scheme
null
Phys. Rev. D 89, 016013 (2014)
10.1103/PhysRevD.89.016013
CP3-Origins-2013-033 DNRF90, DIAS-2013-33
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the evolution of the gauge coupling and the anomalous dimension of the mass towards an infrared fixed point for non-supersymmetric gauge theories in the modified regularization invariant, RI', scheme. This is done at the three loop level where all the renormalization group functions have been calculated explicitly. The purpose is to assess the scheme dependence of earlier and similar investigations performed at three and four loop order in the modified minimal subtraction, $\bar{\text{MS}}$, scheme. Our results are of the same order when compared to the $\bar{\text{MS}}$ scheme.
[ { "created": "Mon, 16 Sep 2013 09:09:08 GMT", "version": "v1" } ]
2014-01-14
[ [ "Ryttov", "Thomas A.", "" ] ]
We study the evolution of the gauge coupling and the anomalous dimension of the mass towards an infrared fixed point for non-supersymmetric gauge theories in the modified regularization invariant, RI', scheme. This is done at the three loop level where all the renormalization group functions have been calculated explicitly. The purpose is to assess the scheme dependence of earlier and similar investigations performed at three and four loop order in the modified minimal subtraction, $\bar{\text{MS}}$, scheme. Our results are of the same order when compared to the $\bar{\text{MS}}$ scheme.
2407.15928
Hector Gisbert Mullor
Luca Di Luzio, Hector Gisbert, Fabrizio Nesti, Philip S{\o}rensen
Axion Window on New Macroscopic Forces
8 pages, 1 figure, 1 appendix
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Axion-mediated forces are enhanced by the presence of CP-violating axion couplings, which are however tightly constrained by electric dipole moment (EDM) searches. We discuss the underlying hypotheses behind different sources of CP violation at high energies and the interplay between axion-mediated force experiments and EDM observables. Specifically, we identify various mechanisms, based on new sources of CP violation or Peccei-Quinn symmetry breaking, that can significantly relax EDM constraints, leading to a substantial redefinition of the QCD axion window for axion-mediated forces. By considerably enlarging the QCD axion parameter space, our results provide a well-motivated target for experiments probing scalar axion couplings to matter fields. These include fifth-force tests of gravity, as well as searches for spin-dependent forces via precision magnetometry, proton storage rings and ultracold molecules.
[ { "created": "Mon, 22 Jul 2024 18:00:01 GMT", "version": "v1" } ]
2024-07-24
[ [ "Di Luzio", "Luca", "" ], [ "Gisbert", "Hector", "" ], [ "Nesti", "Fabrizio", "" ], [ "Sørensen", "Philip", "" ] ]
Axion-mediated forces are enhanced by the presence of CP-violating axion couplings, which are however tightly constrained by electric dipole moment (EDM) searches. We discuss the underlying hypotheses behind different sources of CP violation at high energies and the interplay between axion-mediated force experiments and EDM observables. Specifically, we identify various mechanisms, based on new sources of CP violation or Peccei-Quinn symmetry breaking, that can significantly relax EDM constraints, leading to a substantial redefinition of the QCD axion window for axion-mediated forces. By considerably enlarging the QCD axion parameter space, our results provide a well-motivated target for experiments probing scalar axion couplings to matter fields. These include fifth-force tests of gravity, as well as searches for spin-dependent forces via precision magnetometry, proton storage rings and ultracold molecules.
hep-ph/0112017
Ismd31
Eugene T. Yamamoto
Resonance Production at STAR
8 pages, 7 figures (in eps) talk given at XXXI International Symposium on Multiparticle Dynamics, Sep. 1-7, 2001, Datong China at http://ismd31.ccnu.edu.cn/
null
10.1142/9789812778048_0025
null
hep-ph
null
We present the first measurement of mid-rapidity $\phi$ vector meson production in $Au+Au$ collisions at RHIC ($\sqrt{s_{_{NN}}} =130$ GeV) from the STAR detector. For the 11% most central collisions, the slope parameter from an exponential fit to the transverse mass distribution is $T=$~379$\pm$51(stat) $\pm$ 45(syst)~MeV, the yield $dN/dy$ $=5.73\pm$0.37(stat)$\pm$ 0.57(syst) per event and the ratio $N_{\phi}/N_{h^-}$ is found to be 0.021$\pm$0.001(stat)$\pm$ 0.03(syst). We currently place the value of the $N_{\phi}/N_{K^-}$ ratio between 0.10 and 0.16. The measured ratios $N_{\phi}/N_{h^-}$ and $N_{\phi}/N_{K^-}$, as well as $T$ for the $\phi$ meson at mid-rapidity do not change for the selected centrality bins.
[ { "created": "Mon, 3 Dec 2001 09:33:29 GMT", "version": "v1" } ]
2017-08-23
[ [ "Yamamoto", "Eugene T.", "" ] ]
We present the first measurement of mid-rapidity $\phi$ vector meson production in $Au+Au$ collisions at RHIC ($\sqrt{s_{_{NN}}} =130$ GeV) from the STAR detector. For the 11% most central collisions, the slope parameter from an exponential fit to the transverse mass distribution is $T=$~379$\pm$51(stat) $\pm$ 45(syst)~MeV, the yield $dN/dy$ $=5.73\pm$0.37(stat)$\pm$ 0.57(syst) per event and the ratio $N_{\phi}/N_{h^-}$ is found to be 0.021$\pm$0.001(stat)$\pm$ 0.03(syst). We currently place the value of the $N_{\phi}/N_{K^-}$ ratio between 0.10 and 0.16. The measured ratios $N_{\phi}/N_{h^-}$ and $N_{\phi}/N_{K^-}$, as well as $T$ for the $\phi$ meson at mid-rapidity do not change for the selected centrality bins.
hep-ph/9802263
Nikos Ganoulis
C. Panagiotakopoulos
Large Field Inflation in Supergravity
17 pages, Revtex, 6 ps figures. New title, partially rewritten and extended. To be published in Phys. Rev. D
Phys.Rev. D59 (1999) 063502
10.1103/PhysRevD.59.063502
null
hep-ph
null
We present a supergravity inflationary scenario in which the inflaton field takes values considerably larger than the Planck scale. It is based on a class of inflationary potentials which can be derived from ``singular'' Kaehler potentials assuming simple superpotentials of the type $W\simS^n$. To this class belong, among many others, all potentials which are even infinitesimally smaller than the one derived from the minimal Kaehler potential. Our scenario allows for a detectable gravitational wave contribution to the microwave background anisotropy.
[ { "created": "Fri, 6 Feb 1998 17:18:40 GMT", "version": "v1" }, { "created": "Fri, 11 Dec 1998 12:24:54 GMT", "version": "v2" } ]
2009-10-31
[ [ "Panagiotakopoulos", "C.", "" ] ]
We present a supergravity inflationary scenario in which the inflaton field takes values considerably larger than the Planck scale. It is based on a class of inflationary potentials which can be derived from ``singular'' Kaehler potentials assuming simple superpotentials of the type $W\simS^n$. To this class belong, among many others, all potentials which are even infinitesimally smaller than the one derived from the minimal Kaehler potential. Our scenario allows for a detectable gravitational wave contribution to the microwave background anisotropy.
2202.12310
Himanshu Swami
Himanshu Swami
Neutrino flavor oscillations in a rotating spacetime
23 pages, 4 figures, published version
Eur. Phys. J. C (2022) 82:974
10.1140/epjc/s10052-022-10902-z
null
hep-ph gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study neutrino oscillations in a rotating spacetime under the weak gravity limit for the trajectories of neutrinos which are constrained in the equatorial plane. Using the asymptotic form of the Kerr metric, we show that the rotation of the gravitational source non-trivially modifies the neutrino phase. We find that the oscillation probabilities deviate significantly from the corresponding results in the Schwarzschild spacetime when neutrinos are produced near the black hole (still in the weak-gravity limit) with non-zero angular momentum and detected on the same side, i.e., the non-lensed neutrino. Moreover, for a given gravitational body and geometric parameters, there exists a distance scale for every energy scale (and vice versa), after which the rotational contribution in the neutrino phase becomes significant. Using the sun-sized gravitational body in the numerical analysis of the one-sided neutrino propagation, we show that even a small rotation of the gravitational object can significantly change the survival or appearance events of a neutrino flavor registered by the detector, which is located on the earth. These effects are expected to be prominent for cosmological/astrophysical scenarios where neutrinos travel past by many (rotating) gravitational bodies and for large distances. Thus rotational effects of all such bodies must be incorporated in analyzing oscillations data.
[ { "created": "Thu, 24 Feb 2022 19:00:17 GMT", "version": "v1" }, { "created": "Mon, 31 Oct 2022 16:47:03 GMT", "version": "v2" } ]
2022-11-01
[ [ "Swami", "Himanshu", "" ] ]
We study neutrino oscillations in a rotating spacetime under the weak gravity limit for the trajectories of neutrinos which are constrained in the equatorial plane. Using the asymptotic form of the Kerr metric, we show that the rotation of the gravitational source non-trivially modifies the neutrino phase. We find that the oscillation probabilities deviate significantly from the corresponding results in the Schwarzschild spacetime when neutrinos are produced near the black hole (still in the weak-gravity limit) with non-zero angular momentum and detected on the same side, i.e., the non-lensed neutrino. Moreover, for a given gravitational body and geometric parameters, there exists a distance scale for every energy scale (and vice versa), after which the rotational contribution in the neutrino phase becomes significant. Using the sun-sized gravitational body in the numerical analysis of the one-sided neutrino propagation, we show that even a small rotation of the gravitational object can significantly change the survival or appearance events of a neutrino flavor registered by the detector, which is located on the earth. These effects are expected to be prominent for cosmological/astrophysical scenarios where neutrinos travel past by many (rotating) gravitational bodies and for large distances. Thus rotational effects of all such bodies must be incorporated in analyzing oscillations data.
1407.0993
Anthony Fradette
Anthony Fradette, Maxim Pospelov, Josef Pradler and Adam Ritz
Cosmological Constraints on Very Dark Photons
14 pages, 11 figures, references added
Phys. Rev. D 90, 035022 (2014)
10.1103/PhysRevD.90.035022
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the cosmological consequences of kinetically mixed dark photons with a mass between 1 MeV and 10 GeV, and an effective electromagnetic fine structure constant as small as $10^{-38}$. We calculate the freeze-in abundance of these dark photons in the early Universe and explore the impact of late decays on BBN and the CMB. This leads to new constraints on the parameter space of mass $m_V$ vs kinetic mixing parameter $\kappa$.
[ { "created": "Thu, 3 Jul 2014 17:39:14 GMT", "version": "v1" }, { "created": "Thu, 10 Jul 2014 22:31:49 GMT", "version": "v2" } ]
2014-09-05
[ [ "Fradette", "Anthony", "" ], [ "Pospelov", "Maxim", "" ], [ "Pradler", "Josef", "" ], [ "Ritz", "Adam", "" ] ]
We explore the cosmological consequences of kinetically mixed dark photons with a mass between 1 MeV and 10 GeV, and an effective electromagnetic fine structure constant as small as $10^{-38}$. We calculate the freeze-in abundance of these dark photons in the early Universe and explore the impact of late decays on BBN and the CMB. This leads to new constraints on the parameter space of mass $m_V$ vs kinetic mixing parameter $\kappa$.
hep-ph/0402286
Vladimir Nechitailo A.
I.M. Dremin and V.A. Nechitailo
Independent pair parton interactions-model of hadron interactions
10 pages, 8 figures, revtex4, typos added
Phys.Rev.D70:034005,2004
10.1103/PhysRevD.70.034005
null
hep-ph
null
A model of independent pair parton interactions is proposed, according to which, hadron interactions are represented by a set of independent binary parton collisions. The final multiplicity distribution is described by a convolution of the negative binomial distributions in each of the partonic collisions. As a result, it is given by a weighted sum of negative binomial distributions with parameters multiplied by the number of active pairs. Its shape and moments are considered. Experimental data on multiplicity distributions in high energy $p\bar p$ processes are well fitted by these distributions. Predictions for the CERN Large Hadron Collider and higher energies are presented. The difference between $e^+e^-$ and $p\bar p$ processes is discussed.
[ { "created": "Fri, 27 Feb 2004 09:52:00 GMT", "version": "v1" }, { "created": "Tue, 31 Aug 2004 13:57:29 GMT", "version": "v2" } ]
2011-07-19
[ [ "Dremin", "I. M.", "" ], [ "Nechitailo", "V. A.", "" ] ]
A model of independent pair parton interactions is proposed, according to which, hadron interactions are represented by a set of independent binary parton collisions. The final multiplicity distribution is described by a convolution of the negative binomial distributions in each of the partonic collisions. As a result, it is given by a weighted sum of negative binomial distributions with parameters multiplied by the number of active pairs. Its shape and moments are considered. Experimental data on multiplicity distributions in high energy $p\bar p$ processes are well fitted by these distributions. Predictions for the CERN Large Hadron Collider and higher energies are presented. The difference between $e^+e^-$ and $p\bar p$ processes is discussed.
1501.03888
Masaki J.S. Yang
Masaki J.S. Yang
A symmetry breaking mechanism by parity assignment in the noncommutative Higgs model
10 pages, 1 figure, the final version to appear in Progress of Theoretical and Experimental Physics (PTEP)
null
10.1093/ptep/ptv051
KEK-TH-1791
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We apply the orbifold grand unified theory (GUT) mechanism to the noncommutative Higgs model. An assignment of $Z_{2}$ parity to the "constituent fields" induces parity assignments of both the gauge and Higgs bosons, because these bosons are treated as some kind of composite field in this formalism. As a result, some of the gauge bosons and the colored triplet Higgs boson receive heavy mass comparable to the GUT scale, and the gauge symmetry is broken. No particles appear other than the SM ones in the massless states.
[ { "created": "Fri, 16 Jan 2015 06:28:11 GMT", "version": "v1" }, { "created": "Sun, 1 Nov 2015 05:10:11 GMT", "version": "v2" } ]
2015-11-03
[ [ "Yang", "Masaki J. S.", "" ] ]
We apply the orbifold grand unified theory (GUT) mechanism to the noncommutative Higgs model. An assignment of $Z_{2}$ parity to the "constituent fields" induces parity assignments of both the gauge and Higgs bosons, because these bosons are treated as some kind of composite field in this formalism. As a result, some of the gauge bosons and the colored triplet Higgs boson receive heavy mass comparable to the GUT scale, and the gauge symmetry is broken. No particles appear other than the SM ones in the massless states.
1311.7260
Victor Martin Lozano
David G. Cerdeno, Victor Martin-Lozano, Osamu Seto
Displaced vertices and long-lived charged particles in the NMSSM with right-handed sneutrinos
31 pages, 11 figures. Table 1 enlarged. Comments added. Matches with the published version in JHEP
JHEP 1405 (2014) 035
10.1007/JHEP05(2014)035
IFT-UAM/CSIC-13-126, FTUAM 13/36, HGU-CAP-027
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study LHC signatures of displaced vertices and long-lived charged particles within the context of the Next-to-Minimal Supersymmetric Standard Model with right-handed (RH) sneutrinos. In this construction the RH neutrino can be produced directly from Higgs decays or in association with a RH sneutrino when the latter is the lightest supersymmetric particle. The RH neutrino is generally long-lived, since its decay width is proportional to the neutrino Yukawa, a parameter which is predicted to be small. The RH neutrino late decay can therefore give rise to displaced vertices at the LHC, which can be identified through the decay products, which involve two leptons (2l+ MET) or a lepton with two jets (ljj). We simulate this signal for the current LHC configuration (a centre of mass of 8 TeV and an integrated luminosity of L=20 fb^-1), and a future one (13 TeV and L=100 fb^-1). We show that a region of the parameter space of this model can be probed and that the RH neutrino mass can be reconstructed from the end-point of the two-lepton invariant mass distribution or the central value of the mass distribution for two jets plus one lepton. Another exotic signature of this construction is the production of a long-lived stau. If the stau is the next-to-lightest supersymmetric particle, it can decay through diagrams involving the small neutrino Yukawa, and would escape the detector leaving a characteristic trail. We also simulate this signal for various benchmark points and show that the model can be within the reach of the future run of the LHC.
[ { "created": "Thu, 28 Nov 2013 10:18:53 GMT", "version": "v1" }, { "created": "Wed, 21 May 2014 10:49:11 GMT", "version": "v2" } ]
2014-05-22
[ [ "Cerdeno", "David G.", "" ], [ "Martin-Lozano", "Victor", "" ], [ "Seto", "Osamu", "" ] ]
We study LHC signatures of displaced vertices and long-lived charged particles within the context of the Next-to-Minimal Supersymmetric Standard Model with right-handed (RH) sneutrinos. In this construction the RH neutrino can be produced directly from Higgs decays or in association with a RH sneutrino when the latter is the lightest supersymmetric particle. The RH neutrino is generally long-lived, since its decay width is proportional to the neutrino Yukawa, a parameter which is predicted to be small. The RH neutrino late decay can therefore give rise to displaced vertices at the LHC, which can be identified through the decay products, which involve two leptons (2l+ MET) or a lepton with two jets (ljj). We simulate this signal for the current LHC configuration (a centre of mass of 8 TeV and an integrated luminosity of L=20 fb^-1), and a future one (13 TeV and L=100 fb^-1). We show that a region of the parameter space of this model can be probed and that the RH neutrino mass can be reconstructed from the end-point of the two-lepton invariant mass distribution or the central value of the mass distribution for two jets plus one lepton. Another exotic signature of this construction is the production of a long-lived stau. If the stau is the next-to-lightest supersymmetric particle, it can decay through diagrams involving the small neutrino Yukawa, and would escape the detector leaving a characteristic trail. We also simulate this signal for various benchmark points and show that the model can be within the reach of the future run of the LHC.
0910.4521
Kazem Azizi
K. Azizi, M. Bayar, M. T. Zeyrek
Flavor Changing Neutral Currents Transition of the $\Sigma_{Q}$ to Nucleon in Full QCD and Heavy Quark Effective Theory
18 Pages and 13 Tables
J.Phys.G37:085002,2010
10.1088/0954-3899/37/8/085002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The loop level flavor changing neutral currents transitions of the $\Sigma_{b}\to n l^+l^-$ and $\Sigma_{c}\to p l^+l^-$ are investigated in full QCD and heavy quark effective theory in the light cone QCD sum rules approach. Using the most general form of the interpolating current for $\Sigma_{Q}$, $Q=b$ or $c$, as members of the recently discovered sextet heavy baryons with spin 1/2 and containing one heavy quark, the transition form factors are calculated using two sets of input parameters entering the nucleon distribution amplitudes, namely, QCD sum rules and lattice QCD inputs. The obtained results are used to estimate the decay rates of the corresponding transitions. Since such type transitions occurred at loop level in the standard model, they can be considered as good candidates to search for the new physics effects beyond the SM.
[ { "created": "Fri, 23 Oct 2009 14:35:54 GMT", "version": "v1" }, { "created": "Sun, 6 Dec 2009 10:56:38 GMT", "version": "v2" }, { "created": "Mon, 17 May 2010 14:50:35 GMT", "version": "v3" } ]
2014-11-20
[ [ "Azizi", "K.", "" ], [ "Bayar", "M.", "" ], [ "Zeyrek", "M. T.", "" ] ]
The loop level flavor changing neutral currents transitions of the $\Sigma_{b}\to n l^+l^-$ and $\Sigma_{c}\to p l^+l^-$ are investigated in full QCD and heavy quark effective theory in the light cone QCD sum rules approach. Using the most general form of the interpolating current for $\Sigma_{Q}$, $Q=b$ or $c$, as members of the recently discovered sextet heavy baryons with spin 1/2 and containing one heavy quark, the transition form factors are calculated using two sets of input parameters entering the nucleon distribution amplitudes, namely, QCD sum rules and lattice QCD inputs. The obtained results are used to estimate the decay rates of the corresponding transitions. Since such type transitions occurred at loop level in the standard model, they can be considered as good candidates to search for the new physics effects beyond the SM.
1205.1705
Yusuke Shimizu
Yusuke Shimizu, Morimitsu Tanimoto, and Kei Yamamoto
Direct CP violation of $b \rightarrow s\gamma$ and CP asymmetries of non-leptonic B decays in squark flavor mixing
12 pages, 8 figures. arXiv admin note: text overlap with arXiv:1202.0486
Prog. Theor. Phys. 128 (2012), 273-283
10.1143/PTP.128.273
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the contribution of the squark flavor mixing from the $LR(RL)$ component of the squark mass matrices to the direct CP violation of the $b\to s\gamma$ decay and the CP-violating asymmetry in the non-leptonic decays of $B$ mesons. The magnitude of the $LR(RL)$ component is constrained by the branching ratio and the direct CP violation of $b\to s\gamma$. We predict the correlation of the CP asymmetries among $A_{\text{CP}}^{b \to s \gamma}$, $\mathcal{S}_{\phi K_S}$ and $\mathcal{S}_{\eta 'K^0}$ of the B decays. The precise data of these CP violations will give us the crucial test for our framework of the squark flavor mixing.
[ { "created": "Tue, 8 May 2012 14:08:31 GMT", "version": "v1" } ]
2012-09-03
[ [ "Shimizu", "Yusuke", "" ], [ "Tanimoto", "Morimitsu", "" ], [ "Yamamoto", "Kei", "" ] ]
We study the contribution of the squark flavor mixing from the $LR(RL)$ component of the squark mass matrices to the direct CP violation of the $b\to s\gamma$ decay and the CP-violating asymmetry in the non-leptonic decays of $B$ mesons. The magnitude of the $LR(RL)$ component is constrained by the branching ratio and the direct CP violation of $b\to s\gamma$. We predict the correlation of the CP asymmetries among $A_{\text{CP}}^{b \to s \gamma}$, $\mathcal{S}_{\phi K_S}$ and $\mathcal{S}_{\eta 'K^0}$ of the B decays. The precise data of these CP violations will give us the crucial test for our framework of the squark flavor mixing.
hep-ph/0101137
Omar Miranda Romagnoli
O. G. Miranda
Tests of physics beyond the Standard Model with future low energy neutrino experiments
4 pages. Talk given at the EuroConference on Frontiers in Particle Astrophysics and Cosmology, San Feliu de Guixols, Spain, 30 September - 5 October, 2000
Nucl.Phys.Proc.Suppl. 95 (2001) 173-176
10.1016/S0920-5632(01)01078-7
null
hep-ph
null
Neutrino-electron scattering can be used to probe neutrino electromagnetic properties at low-threshold underground detectors with good recoil electron energy resolution. We study the sensitivity of Helium detector experiments, such as HELLAZ, for artificial anti-neutrino sources. We show that, for a $^{90}Sr-Y$ source, one expects a sensitivity to the neutrino magnetic moment at the level of $\mu_{\nu}= 2 \times 10^{-11}\mu_{B}$. We also report the sensitivity that these experiments could have in searching for an additional gauge boson in $E_6$ models.
[ { "created": "Fri, 12 Jan 2001 21:37:51 GMT", "version": "v1" } ]
2009-11-07
[ [ "Miranda", "O. G.", "" ] ]
Neutrino-electron scattering can be used to probe neutrino electromagnetic properties at low-threshold underground detectors with good recoil electron energy resolution. We study the sensitivity of Helium detector experiments, such as HELLAZ, for artificial anti-neutrino sources. We show that, for a $^{90}Sr-Y$ source, one expects a sensitivity to the neutrino magnetic moment at the level of $\mu_{\nu}= 2 \times 10^{-11}\mu_{B}$. We also report the sensitivity that these experiments could have in searching for an additional gauge boson in $E_6$ models.
hep-ph/0209254
Armen Oganesian
B.L.Ioffe (ITEP)
Distribution of valence quarks in hadrons in QCD: theoretical method of calculations
11 pages, LaTeX 2e, 5 eps figures included
null
null
null
hep-ph
null
The general method for calculation of valence quark distributions in hadrons at intermediate $x$ is presented. The imaginary part of virtual photon forward scattering amplitude on quark current with hadron quantum number is considered in the case, when initial and final virtualities of the current $p^2_1$ and $p^2_2$ are different, negative and large: $\mid p^2_1\mid, \mid p^2_2\mid\gg R^{-2}_c$, where $R_c$ is confinement radius. The operator product expansion (OPE) in $p^2_1,p^2_2$ up to dimension 6 operators is performed. Double dispersion representations in $p^2_1, p^2_2$ of the amplitude in terms of physical states contributions are used. Equalling them to those calculated in QCD by OPE the desired sum rules for quark distributions in mesons are found. The double Borel transformations are applied to the sum rules, killing non-diagonal transition terms, which deteriorated the accuracy in the previous calculations of quark distributions in nucleon. Leading order perturbative corrections are accounted. Valence quark distributions in pion, longitudinally and transversally polarized $\rho$-mesons and proton are calculated at intermediate $x$, $0.2 \la x \la 0.7$ and normalization points $Q^2 = 2-5 \~GeV^2$ with no fitting parameters. In cases of pion and proton the results are in agreement with found correspondingly from the data on the Drell-Yan process and deep inelastic scattering. Valence quark distributions in transversally and longitudinally polarized $\rho$-mesons are essentially different one from another and also differ from those in pion.
[ { "created": "Mon, 23 Sep 2002 13:30:28 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ioffe", "B. L.", "", "ITEP" ] ]
The general method for calculation of valence quark distributions in hadrons at intermediate $x$ is presented. The imaginary part of virtual photon forward scattering amplitude on quark current with hadron quantum number is considered in the case, when initial and final virtualities of the current $p^2_1$ and $p^2_2$ are different, negative and large: $\mid p^2_1\mid, \mid p^2_2\mid\gg R^{-2}_c$, where $R_c$ is confinement radius. The operator product expansion (OPE) in $p^2_1,p^2_2$ up to dimension 6 operators is performed. Double dispersion representations in $p^2_1, p^2_2$ of the amplitude in terms of physical states contributions are used. Equalling them to those calculated in QCD by OPE the desired sum rules for quark distributions in mesons are found. The double Borel transformations are applied to the sum rules, killing non-diagonal transition terms, which deteriorated the accuracy in the previous calculations of quark distributions in nucleon. Leading order perturbative corrections are accounted. Valence quark distributions in pion, longitudinally and transversally polarized $\rho$-mesons and proton are calculated at intermediate $x$, $0.2 \la x \la 0.7$ and normalization points $Q^2 = 2-5 \~GeV^2$ with no fitting parameters. In cases of pion and proton the results are in agreement with found correspondingly from the data on the Drell-Yan process and deep inelastic scattering. Valence quark distributions in transversally and longitudinally polarized $\rho$-mesons are essentially different one from another and also differ from those in pion.
2104.12783
Alberto Salvio
Alberto Salvio
Hearing Higgs with Gravitational Wave Detectors
v2: 20 pages, 2 figures, published version
JCAP 06 (2021) 040
10.1088/1475-7516/2021/06/040
null
hep-ph astro-ph.CO hep-th
http://creativecommons.org/licenses/by/4.0/
The relic gravitational wave background due to tensor linear perturbations generated during Higgs inflation is computed. Both the Standard Model and a well-motivated phenomenological completion (that accounts for all the experimentally confirmed evidence of new physics) are considered. We focus on critical Higgs inflation, which improves on the non-critical version and features an amplification of the tensor fluctuations. The latter property allows us to establish that future space-borne interferometers, such as DECIGO, BBO and ALIA, may detect the corresponding primordial gravitational waves.
[ { "created": "Mon, 26 Apr 2021 18:00:02 GMT", "version": "v1" }, { "created": "Thu, 24 Jun 2021 15:30:53 GMT", "version": "v2" } ]
2021-06-25
[ [ "Salvio", "Alberto", "" ] ]
The relic gravitational wave background due to tensor linear perturbations generated during Higgs inflation is computed. Both the Standard Model and a well-motivated phenomenological completion (that accounts for all the experimentally confirmed evidence of new physics) are considered. We focus on critical Higgs inflation, which improves on the non-critical version and features an amplification of the tensor fluctuations. The latter property allows us to establish that future space-borne interferometers, such as DECIGO, BBO and ALIA, may detect the corresponding primordial gravitational waves.
1907.12869
Prasenjit Paul
Prasenjit Paul and Rikpratik Sengupta
Generalized phenomenological models of dark energy
6 pages, 7 figures
Advances in High Energy Physics,Volume 2020, Article ID 5249839
10.1155/2020/5249839
null
hep-ph gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It was first observed at the end of the last century that the universe is presently accelerating. Ever since, there have been several attempts to explain this observation theoretically. There are two possible approaches. The more conventional one is to modify the matter part of the Einstein Field Equations and the second one is to modify the geometry part. We shall consider two phenomenological models based on the former, more conventional approach within the context of General Relativity. The phenomenological models in this paper consider a $\Lambda$ term as a function of $\frac{\ddot{a}}{a}$ and $\rho$ where $a$ and $\rho$ are the scale factor and matter-energy density respectively. Constraining the free parameters of the models with latest observational data gives satisfactory values of parameters as considered by us initially. Without any field-theoretic interpretation, we explain the recent observations with a dynamical cosmological constant.
[ { "created": "Tue, 30 Jul 2019 13:01:47 GMT", "version": "v1" } ]
2020-04-14
[ [ "Paul", "Prasenjit", "" ], [ "Sengupta", "Rikpratik", "" ] ]
It was first observed at the end of the last century that the universe is presently accelerating. Ever since, there have been several attempts to explain this observation theoretically. There are two possible approaches. The more conventional one is to modify the matter part of the Einstein Field Equations and the second one is to modify the geometry part. We shall consider two phenomenological models based on the former, more conventional approach within the context of General Relativity. The phenomenological models in this paper consider a $\Lambda$ term as a function of $\frac{\ddot{a}}{a}$ and $\rho$ where $a$ and $\rho$ are the scale factor and matter-energy density respectively. Constraining the free parameters of the models with latest observational data gives satisfactory values of parameters as considered by us initially. Without any field-theoretic interpretation, we explain the recent observations with a dynamical cosmological constant.
hep-ph/0312319
Adam K. Leibovich
Adam K. Leibovich, Zoltan Ligeti, Iain W. Stewart, and Mark B. Wise
Predictions for nonleptonic Lambda_b and Theta_b decays
12 pages, added references, corrected typos
Phys.Lett.B586:337-344,2004
10.1016/j.physletb.2004.02.033
LBNL-54153, MIT-CTP-3453, CALT-68-2467
hep-ph hep-ex
null
We study nonleptonic Lambda_b -> Lambda_c pi, Sigma_c pi and Sigma_c^* pi decays in the limit m_b, m_c, E_pi >> Lambda_{QCD} using the soft-collinear effective theory. Here Sigma_c = Sigma_c(2455) and Sigma_c^* = Sigma_c(2520). At leading order the Lambda_b -> Sigma_c^{(*)} pi rates vanish, while the Lambda_b -> Lambda_c pi rate is related to Lambda_b -> Lambda_c\ell\bar\nu, and is expected to be larger than Gamma(B -> D^{(*)} pi). The dominant contributions to the Lambda_b -> Sigma_c^{(*)} pi rates are suppressed by Lambda_{QCD}^2/E_pi^2. We predict Gamma(Lambda_b -> Sigma_c^* pi) / Gamma(Lambda_b -> Sigma_c pi) = 2 + O[Lambda_{QCD}/m_Q, alpha_s(m_Q)], and the same ratio for Lambda_b -> Sigma_c^{(*)} rho and for Lambda_b -> Xi_c^{(',*)}K. ``Bow tie'' diagrams are shown to be suppressed. We comment on possible discovery channels for weakly decaying pentaquarks, Theta_{b,c} and their nearby heavy quark spin symmetry partners, Theta_{b,c}^*.
[ { "created": "Mon, 22 Dec 2003 18:36:20 GMT", "version": "v1" }, { "created": "Mon, 5 Jan 2004 22:21:07 GMT", "version": "v2" } ]
2014-11-17
[ [ "Leibovich", "Adam K.", "" ], [ "Ligeti", "Zoltan", "" ], [ "Stewart", "Iain W.", "" ], [ "Wise", "Mark B.", "" ] ]
We study nonleptonic Lambda_b -> Lambda_c pi, Sigma_c pi and Sigma_c^* pi decays in the limit m_b, m_c, E_pi >> Lambda_{QCD} using the soft-collinear effective theory. Here Sigma_c = Sigma_c(2455) and Sigma_c^* = Sigma_c(2520). At leading order the Lambda_b -> Sigma_c^{(*)} pi rates vanish, while the Lambda_b -> Lambda_c pi rate is related to Lambda_b -> Lambda_c\ell\bar\nu, and is expected to be larger than Gamma(B -> D^{(*)} pi). The dominant contributions to the Lambda_b -> Sigma_c^{(*)} pi rates are suppressed by Lambda_{QCD}^2/E_pi^2. We predict Gamma(Lambda_b -> Sigma_c^* pi) / Gamma(Lambda_b -> Sigma_c pi) = 2 + O[Lambda_{QCD}/m_Q, alpha_s(m_Q)], and the same ratio for Lambda_b -> Sigma_c^{(*)} rho and for Lambda_b -> Xi_c^{(',*)}K. ``Bow tie'' diagrams are shown to be suppressed. We comment on possible discovery channels for weakly decaying pentaquarks, Theta_{b,c} and their nearby heavy quark spin symmetry partners, Theta_{b,c}^*.
2008.03629
Hyun Min Lee
Ligong Bian, Hyun Min Lee, Chan Beom Park
Flavor and CP-violating Higgs sector in two Higgs doublet models with $U(1)'$
37 pages, 5 figures, Journal version
null
10.1007/s40042-021-00191-2
null
hep-ph
http://creativecommons.org/licenses/by-nc-sa/4.0/
We investigate the role of a local $U(1)'$ symmetry for the problem of CP violation in the effective theory for two Higgs doublet models and its microscopic counterparts. First, in two Higgs doublet models with $U(1)'$, we show that the higher-dimensional operators in the scalar potential violate the CP symmetry with an interplay with the mixing mass parameter, giving rise to small mixings between CP-even and CP-odd scalars. Motivated by the $B$-meson anomalies in recent years, we take the flavored $U(1)'$ to be a benchmark model for specifying the flavor structure. Then, we calculate the electric dipole moment of electron (eEDM) at two loops due to the CP-violating higher-dimensional operators and identify the correlation between the masses of heavy Higgs bosons and the cutoff scale from the bound on eEDM. We also comment on the possibility of making an independent test of the CP violation in the collider searches for heavy Higgs bosons. Finally, we show how the obtained eEDM results in the effective theory can be used to constrain microscopic models with an explicit CP violation in the partially decoupled or dark sectors.
[ { "created": "Sun, 9 Aug 2020 02:26:33 GMT", "version": "v1" }, { "created": "Wed, 7 Apr 2021 14:05:45 GMT", "version": "v2" } ]
2021-06-09
[ [ "Bian", "Ligong", "" ], [ "Lee", "Hyun Min", "" ], [ "Park", "Chan Beom", "" ] ]
We investigate the role of a local $U(1)'$ symmetry for the problem of CP violation in the effective theory for two Higgs doublet models and its microscopic counterparts. First, in two Higgs doublet models with $U(1)'$, we show that the higher-dimensional operators in the scalar potential violate the CP symmetry with an interplay with the mixing mass parameter, giving rise to small mixings between CP-even and CP-odd scalars. Motivated by the $B$-meson anomalies in recent years, we take the flavored $U(1)'$ to be a benchmark model for specifying the flavor structure. Then, we calculate the electric dipole moment of electron (eEDM) at two loops due to the CP-violating higher-dimensional operators and identify the correlation between the masses of heavy Higgs bosons and the cutoff scale from the bound on eEDM. We also comment on the possibility of making an independent test of the CP violation in the collider searches for heavy Higgs bosons. Finally, we show how the obtained eEDM results in the effective theory can be used to constrain microscopic models with an explicit CP violation in the partially decoupled or dark sectors.
1711.02369
Zolt\'an Nagy
Zoltan Nagy and Davison E. Soper
Jets and threshold summation in Deductor
47 pages, 11 figures, published version
Phys. Rev. D 98, 014035 (2018)
10.1103/PhysRevD.98.014035
DESY 17-179
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore jet physics in hadron collisions using the parton shower event generator Deductor. Of particular interest is the one jet inclusive cross section dsigma/dpT for jets of very high pT. Compared to the Born level, the cross section decreases substantially because of pT loss from the jet during showering. We compare to the same effect in Pythia and Dire. The cross section then increases substantially because of the summation of threshold logarithms included in Deductor. We also study the cross section to have a gap with no jets between two hard jets that are widely separated in rapidity. Here we compare Deductor with virtuality based ordering with Deductor with kT ordering and we check whether adding an underlying event and hadronization has a significant effect beyond that found with just a parton shower.
[ { "created": "Tue, 7 Nov 2017 10:06:53 GMT", "version": "v1" }, { "created": "Wed, 19 Sep 2018 19:10:57 GMT", "version": "v2" } ]
2018-09-21
[ [ "Nagy", "Zoltan", "" ], [ "Soper", "Davison E.", "" ] ]
We explore jet physics in hadron collisions using the parton shower event generator Deductor. Of particular interest is the one jet inclusive cross section dsigma/dpT for jets of very high pT. Compared to the Born level, the cross section decreases substantially because of pT loss from the jet during showering. We compare to the same effect in Pythia and Dire. The cross section then increases substantially because of the summation of threshold logarithms included in Deductor. We also study the cross section to have a gap with no jets between two hard jets that are widely separated in rapidity. Here we compare Deductor with virtuality based ordering with Deductor with kT ordering and we check whether adding an underlying event and hadronization has a significant effect beyond that found with just a parton shower.
2008.02733
Vlasios Petousis
Vlasios Petousis, Martin Veselsky, Jozef Leja
Neutron star structure with nuclear force mediated by hypothetical X17 boson
5 pages, 4 figures, To appear in the EPJ Web of Conferences
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A reported ${17~}$MeV boson, which has been proposed as an explanation to the $^{8}$Be and $^{4}$He anomaly, is investigated in the context of its possible influence to neutron stars structure. Implementing a $m_{X}$=17 MeV to the nuclear equation of state using different incompressibility values K$_{0}$=245 MeV and K$_{0}$=260 MeV and solving Tolman-Oppenheimer-Volkoff equations, we estimate an upper limit of ${M_{TOV}\thickapprox 2.4M\odot}$ for a non rotating neutron star with span in radius ${R}$ between ${11.5~}$km to ${14~}$km. Moving away from pure - NN with admixture of 10\% protons and simulating possible softening of equation of state due to hyperons, we see that our estimated limits fit quite well inside the newest reported studies, coming from neutron stars merger event, GW190814
[ { "created": "Wed, 5 Aug 2020 16:09:17 GMT", "version": "v1" }, { "created": "Fri, 18 Jun 2021 09:16:12 GMT", "version": "v2" }, { "created": "Thu, 8 Jul 2021 08:33:02 GMT", "version": "v3" } ]
2021-07-09
[ [ "Petousis", "Vlasios", "" ], [ "Veselsky", "Martin", "" ], [ "Leja", "Jozef", "" ] ]
A reported ${17~}$MeV boson, which has been proposed as an explanation to the $^{8}$Be and $^{4}$He anomaly, is investigated in the context of its possible influence to neutron stars structure. Implementing a $m_{X}$=17 MeV to the nuclear equation of state using different incompressibility values K$_{0}$=245 MeV and K$_{0}$=260 MeV and solving Tolman-Oppenheimer-Volkoff equations, we estimate an upper limit of ${M_{TOV}\thickapprox 2.4M\odot}$ for a non rotating neutron star with span in radius ${R}$ between ${11.5~}$km to ${14~}$km. Moving away from pure - NN with admixture of 10\% protons and simulating possible softening of equation of state due to hyperons, we see that our estimated limits fit quite well inside the newest reported studies, coming from neutron stars merger event, GW190814
hep-ph/0001258
Bing An Li
Bing An Li (Univ. of Kentucky)
K_{l4} decays
29 pages including 12 figures
Eur.Phys.J.A10:237-244,2001
10.1007/s100500170135
null
hep-ph
null
An effective theory of large N_{C} QCD of mesons has been used to study six K_{l4} decay modes. It has been found that the matrix elements of the axial-vector current dominate the K_{l4} decays. PCAC is satisfied. A relationship between three form factors of axial-vector current has been found. Non-zero phase shifts are originated in \rho-->\pi\pi. The decay rates are calculated in the chiral limit. In this study there is no adjustable parameter.
[ { "created": "Tue, 25 Jan 2000 13:56:44 GMT", "version": "v1" } ]
2014-11-17
[ [ "Li", "Bing An", "", "Univ. of Kentucky" ] ]
An effective theory of large N_{C} QCD of mesons has been used to study six K_{l4} decay modes. It has been found that the matrix elements of the axial-vector current dominate the K_{l4} decays. PCAC is satisfied. A relationship between three form factors of axial-vector current has been found. Non-zero phase shifts are originated in \rho-->\pi\pi. The decay rates are calculated in the chiral limit. In this study there is no adjustable parameter.
1202.4391
Chris Quigg
Chris Quigg
Particle Physics in a Season of Change
6 pages, 2 figures, uses PDFLaTeX
null
10.1051/epjconf/20122801001
FERMILAB-CONF-12-035-T
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A digest of my opening remarks at the 2011 Hadron Collider Physics Symposium.
[ { "created": "Mon, 20 Feb 2012 17:23:31 GMT", "version": "v1" } ]
2015-06-04
[ [ "Quigg", "Chris", "" ] ]
A digest of my opening remarks at the 2011 Hadron Collider Physics Symposium.
1807.08951
Jens O. Andersen
Jens O. Andersen and Patrick Kneschke
Bose-Einstein condensation and pion stars
11 pages and 5 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Pion stars consisting of Bose-Einstein condensed charged pions have recently been proposed as a new class of compact stars. We use the two-particle irreducible effective action to leading order in the $1/N$-expansion to describe charged and neutrals pions as well as the sigma particle. Tuning the parameters in the Lagrangian correctly, the onset of Bose-Einstein condesation of charged pions is exactly at $\mu_I=m_{\pi}$, where $\mu_I$ is the isospin chemical potential. We calculate the pressure, energy density, and equation of state, which are used as input to the Tolman-Oppenheimer-Volkov equations. Solving these equations, we obtain the mass radius-relation for pion stars. Global electric charge neutrality is ensured by adding the contribution to the pressure and energy density from a gas of free relativistic leptons. We compare our results with those of recent lattice simulations and find good agreement. The masses of the pion stars are up to approximately 200 solar masses while the corresponding radii are of the order of $10^5$ km.
[ { "created": "Tue, 24 Jul 2018 08:21:22 GMT", "version": "v1" } ]
2018-07-25
[ [ "Andersen", "Jens O.", "" ], [ "Kneschke", "Patrick", "" ] ]
Pion stars consisting of Bose-Einstein condensed charged pions have recently been proposed as a new class of compact stars. We use the two-particle irreducible effective action to leading order in the $1/N$-expansion to describe charged and neutrals pions as well as the sigma particle. Tuning the parameters in the Lagrangian correctly, the onset of Bose-Einstein condesation of charged pions is exactly at $\mu_I=m_{\pi}$, where $\mu_I$ is the isospin chemical potential. We calculate the pressure, energy density, and equation of state, which are used as input to the Tolman-Oppenheimer-Volkov equations. Solving these equations, we obtain the mass radius-relation for pion stars. Global electric charge neutrality is ensured by adding the contribution to the pressure and energy density from a gas of free relativistic leptons. We compare our results with those of recent lattice simulations and find good agreement. The masses of the pion stars are up to approximately 200 solar masses while the corresponding radii are of the order of $10^5$ km.
1207.4672
David London
David London
B Physics: Theory Overview
7 pages. Talk given at the conference Physics at LHC 2012, University of British Columbia, Vancouver, BC, Canada, June 2012. Reference added
null
null
UdeM-GPP-TH-12-210
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This is an overview of B physics that can be done at the LHC with the purpose of searching for new physics.
[ { "created": "Thu, 19 Jul 2012 14:00:04 GMT", "version": "v1" }, { "created": "Mon, 23 Jul 2012 01:25:06 GMT", "version": "v2" } ]
2012-07-24
[ [ "London", "David", "" ] ]
This is an overview of B physics that can be done at the LHC with the purpose of searching for new physics.
1503.05813
Federico Alberto Ceccopieri
Federico Alberto Ceccopieri
Studies of backward particle production with A Fixed-Target Experiment using the LHC beams
Contribution to the special issue on "A Fixed-Target Experiment using the LHC beams". Phenomenological section describing single hard diffraction added. 8 plots added
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The foreseen capability to cover the far backward region at A Fixed-Target Experiment using the LHC beams allows to explore the dynamics of target fragmentation in hadronic collisions. In this report we briefly outline the required theoretical framework and discuss a number of studies of forward and backward particle production. By comparing this knowledge with the one accumulated in Deep Inelastic Scattering on target fragmentation, the basic concept of QCD factorisation could be investigated in detail.
[ { "created": "Thu, 19 Mar 2015 15:56:02 GMT", "version": "v1" }, { "created": "Thu, 28 May 2015 15:31:49 GMT", "version": "v2" } ]
2015-05-29
[ [ "Ceccopieri", "Federico Alberto", "" ] ]
The foreseen capability to cover the far backward region at A Fixed-Target Experiment using the LHC beams allows to explore the dynamics of target fragmentation in hadronic collisions. In this report we briefly outline the required theoretical framework and discuss a number of studies of forward and backward particle production. By comparing this knowledge with the one accumulated in Deep Inelastic Scattering on target fragmentation, the basic concept of QCD factorisation could be investigated in detail.
0804.2688
Jean-Fran\c{c}ois Fortin
Tom Banks, Linda M. Carpenter and Jean-Fran\c{c}ois Fortin
Undetected Higgs decays and neutrino masses in gauge mediated, lepton number violating models
JHEP Latex, 18 pages, 1 figure
JHEP 0809:087,2008
10.1088/1126
RUNHETC-2008-04, SCIPP-08/03
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss SUSY models in which renormalizable lepton number violating couplings hide the decay of the Higgs through h -> \chi_1^0 + \chi_1^0 followed by \chi_1^0 -> \tau + 2 jets or \chi_1^0 -> \nu_\tau + 2 jets and also explain neutrino masses. This mechanism can be made compatible with gauge mediated SUSY breaking.
[ { "created": "Wed, 16 Apr 2008 21:42:45 GMT", "version": "v1" } ]
2009-02-09
[ [ "Banks", "Tom", "" ], [ "Carpenter", "Linda M.", "" ], [ "Fortin", "Jean-François", "" ] ]
We discuss SUSY models in which renormalizable lepton number violating couplings hide the decay of the Higgs through h -> \chi_1^0 + \chi_1^0 followed by \chi_1^0 -> \tau + 2 jets or \chi_1^0 -> \nu_\tau + 2 jets and also explain neutrino masses. This mechanism can be made compatible with gauge mediated SUSY breaking.
hep-ph/0207052
Fridger Schrempp
F. Schrempp (DESY) and A. Utermann (DESY)
Instantons and Saturation in the Colour Dipole Picture
5 pages, 1 figure, presented at the Xth International Workshop on Deep Inelastic Scattering (DIS 2002), Cracow, 30 April - 4 May 2002, one reference added
Acta Phys.Polon. B33 (2002) 3633-3638
null
DESY-02-093
hep-ph
null
We pursue the intriguing possibility that larger-size instantons build up diffractive scattering, with the marked instanton-size scale $<\rho> \approx 0.5$ fm being reflected in the conspicuous ``geometrization'' of soft QCD. As an explicit illustration, the known instanton contribution to DIS is transformed into the intuitive colour dipole picture. With the help of lattice results, the $q \bar{q}$-dipole size r is carefully increased towards hadronic dimensions. Unlike pQCD, one now observes a competition between two crucial length scales: the dipole size r and the size $\rho$ of the background instanton that is sharply localized around $<\rho> \approx 0.5$ fm. For r exceeding $<\rho>$, the dipole cross section indeed saturates towards a geometrical limit, proportional to the area $\pi <\rho>^2$, subtended by the instanton.
[ { "created": "Wed, 3 Jul 2002 16:47:53 GMT", "version": "v1" }, { "created": "Mon, 8 Jul 2002 09:02:47 GMT", "version": "v2" } ]
2007-05-23
[ [ "Schrempp", "F.", "", "DESY" ], [ "Utermann", "A.", "", "DESY" ] ]
We pursue the intriguing possibility that larger-size instantons build up diffractive scattering, with the marked instanton-size scale $<\rho> \approx 0.5$ fm being reflected in the conspicuous ``geometrization'' of soft QCD. As an explicit illustration, the known instanton contribution to DIS is transformed into the intuitive colour dipole picture. With the help of lattice results, the $q \bar{q}$-dipole size r is carefully increased towards hadronic dimensions. Unlike pQCD, one now observes a competition between two crucial length scales: the dipole size r and the size $\rho$ of the background instanton that is sharply localized around $<\rho> \approx 0.5$ fm. For r exceeding $<\rho>$, the dipole cross section indeed saturates towards a geometrical limit, proportional to the area $\pi <\rho>^2$, subtended by the instanton.
1503.01119
Martin Bernhard Krauss
Sofiane M. Boucenna, Martin B. Krauss, Enrico Nardi
Minimal Asymmetric Dark Matter
9 pages, 2 figures, included t-channel scattering, added details on charged-neutral mass splitting and indirect detection, accepted in PLB
null
10.1016/j.physletb.2015.06.080
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the early Universe, any particle carrying a conserved quantum number and in chemical equilibrium with the thermal bath will unavoidably inherit a particle-antiparticle asymmetry. A new particle of this type, if stable, would represent a candidate for asymmetric dark matter (DM) with an asymmetry directly related to the baryon asymmetry. We study this possibility for a minimal DM sector constituted by just one (generic) $SU(2)_L$ multiplet $\chi$ carrying hypercharge, assuming that at temperatures above the electroweak phase transition an effective operator enforces chemical equilibrium between $\chi$ and the Higgs boson. We argue that limits from DM direct detection searches severely constrain this scenario, leaving as the only possibilities scalar or fermion multiplets with hypercharge $y = 1$, preferentially quintuplets or larger $SU(2)$ representations, and with a mass in the few TeV range.
[ { "created": "Tue, 3 Mar 2015 21:00:16 GMT", "version": "v1" }, { "created": "Mon, 23 Mar 2015 19:19:41 GMT", "version": "v2" }, { "created": "Mon, 6 Jul 2015 11:29:13 GMT", "version": "v3" } ]
2015-07-08
[ [ "Boucenna", "Sofiane M.", "" ], [ "Krauss", "Martin B.", "" ], [ "Nardi", "Enrico", "" ] ]
In the early Universe, any particle carrying a conserved quantum number and in chemical equilibrium with the thermal bath will unavoidably inherit a particle-antiparticle asymmetry. A new particle of this type, if stable, would represent a candidate for asymmetric dark matter (DM) with an asymmetry directly related to the baryon asymmetry. We study this possibility for a minimal DM sector constituted by just one (generic) $SU(2)_L$ multiplet $\chi$ carrying hypercharge, assuming that at temperatures above the electroweak phase transition an effective operator enforces chemical equilibrium between $\chi$ and the Higgs boson. We argue that limits from DM direct detection searches severely constrain this scenario, leaving as the only possibilities scalar or fermion multiplets with hypercharge $y = 1$, preferentially quintuplets or larger $SU(2)$ representations, and with a mass in the few TeV range.
0907.1610
Dani\"el Boer
Daniel Boer
Transverse Lambda Polarization at LHC
5 pages, 3 eps figures, uses dis09.cls; Talk presented at the XVII International Workshop on Deep-Inelastic Scattering and Related Subjects (DIS 2009), Madrid, April 26-30, 2009
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Transverse polarization of Lambda hyperons produced in p p and p Pb collisions is discussed. A factorized description in the intermediate to high p_T region is considered that involves transverse momentum and spin dependence in the fragmentation process. Consequences and suggestions for investigations at LHC are pointed out for the process p + p -> Lambda^uparrow + jets + X at midrapidity and p + p/Pb -> Lambda^uparrow + X in the forward region.
[ { "created": "Thu, 9 Jul 2009 16:40:15 GMT", "version": "v1" } ]
2009-07-10
[ [ "Boer", "Daniel", "" ] ]
Transverse polarization of Lambda hyperons produced in p p and p Pb collisions is discussed. A factorized description in the intermediate to high p_T region is considered that involves transverse momentum and spin dependence in the fragmentation process. Consequences and suggestions for investigations at LHC are pointed out for the process p + p -> Lambda^uparrow + jets + X at midrapidity and p + p/Pb -> Lambda^uparrow + X in the forward region.
hep-ph/9305337
Bob Holdom
B. Holdom
Metacolor
11 pages, LaTeX, UTPT-93-09. (The title has changed from "Massless Technicolor" and more discussion of dynamics has been added.)
Phys.Lett. B314 (1993) 89-94
10.1016/0370-2693(93)91326-I
null
hep-ph
null
A new mechanism is presented for the generation of quark and lepton masses, based on a heavy fourth family and a new sector of massless fermions. The massless fermions have only discrete chiral symmetries and they are confined by the metacolor force. The resulting electroweak corrections may be smaller than in technicolor theories.
[ { "created": "Thu, 27 May 1993 16:59:22 GMT", "version": "v1" }, { "created": "Wed, 7 Jul 1993 04:28:40 GMT", "version": "v2" } ]
2009-10-22
[ [ "Holdom", "B.", "" ] ]
A new mechanism is presented for the generation of quark and lepton masses, based on a heavy fourth family and a new sector of massless fermions. The massless fermions have only discrete chiral symmetries and they are confined by the metacolor force. The resulting electroweak corrections may be smaller than in technicolor theories.
1212.0492
Hiroshi Okada
Hiroshi Okada
Dark Matters in Gauged B-3L_i Model
7 pages, 1 table
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study a dark matter model with local B-3L_i symmetry that is known as anomaly free and requires a single right-handed neutrino. Here we have two dark matter candidates; that is, fermionic or bosonic one. We focus on analyzing each of the case within the light mass region, which is required by the perturbative theory of the Higgs quartic coupling.
[ { "created": "Mon, 3 Dec 2012 19:09:18 GMT", "version": "v1" } ]
2012-12-04
[ [ "Okada", "Hiroshi", "" ] ]
We study a dark matter model with local B-3L_i symmetry that is known as anomaly free and requires a single right-handed neutrino. Here we have two dark matter candidates; that is, fermionic or bosonic one. We focus on analyzing each of the case within the light mass region, which is required by the perturbative theory of the Higgs quartic coupling.
hep-ph/9911310
Passarino Giampiero
G.Passarino
The Twofold Way, a Short Disquisition of LEP Physics
16 pages(Latex). To appear in the Proceedings of "XIVth International Workshop: High Energy Physics and Quantum Field Theory (QFTHEP99)", Moscow, Russia, 27 May - 2 June 1999
null
null
null
hep-ph
null
A condensed survey of various aspects of LEP 1 physics is presented with a critical examination of the ingredients that are available for theoretical predictions. A prototype of comparisons for 2f calculations can be found in hep-ph/9902452.
[ { "created": "Thu, 11 Nov 1999 10:15:25 GMT", "version": "v1" } ]
2007-05-23
[ [ "Passarino", "G.", "" ] ]
A condensed survey of various aspects of LEP 1 physics is presented with a critical examination of the ingredients that are available for theoretical predictions. A prototype of comparisons for 2f calculations can be found in hep-ph/9902452.
hep-ph/9506236
Jacek Turnau
W.Czy\.z, J.Turnau
How to Measure Chromo-magnetic Vacuum Background Field in $e^{+}e^{-}\to jets$, Hadron-Hadron and Nucleus-Nucleus Collisions
11 pages,latex,no figures,replaced,final version which takes into account criticisms of referees of Phys.Rev. Title of the paper was changed. The formula (14) was corrected, notation in formulae (12) and (13) changed. Also we added forgotten vectorial notations,corrected misspellings and improved the style and grammar
Phys.Rev. D53 (1996) 1452-1456
10.1103/PhysRevD.53.1452
TPJU 12/95
hep-ph
null
We propose a new type of the measurement which is sensitive to the QCD vacuum color-magnetic fluctuations: A measure of the axial assymetry of the hadronic final states produced in the high energy $e^{+}e^{-}$ collisions is related to the chromomagnetic vacuum field strength.
[ { "created": "Mon, 5 Jun 1995 13:16:23 GMT", "version": "v1" }, { "created": "Thu, 6 Jul 1995 10:35:18 GMT", "version": "v2" }, { "created": "Thu, 28 Sep 1995 09:30:00 GMT", "version": "v3" } ]
2019-08-17
[ [ "Czyż", "W.", "" ], [ "Turnau", "J.", "" ] ]
We propose a new type of the measurement which is sensitive to the QCD vacuum color-magnetic fluctuations: A measure of the axial assymetry of the hadronic final states produced in the high energy $e^{+}e^{-}$ collisions is related to the chromomagnetic vacuum field strength.
1103.5068
Pearl Sandick
Keita Fukushima, Jason Kumar, and Pearl Sandick
Detection Prospects for Majorana Fermion WIMPless Dark Matter
14 pages, 3 figures. v2: updated to match published version
Phys.Rev.D84:014020,2011
10.1103/PhysRevD.84.014020
UH-511-1166-2011, UTTG-06-11, TCC-008-11
hep-ph astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider both velocity-dependent and velocity-independent contributions to spin-dependent (SD) and spin-independent (SI) nuclear scattering (including one-loop corrections) of WIMPless dark matter, in the case where the dark matter candidate is a Majorana fermion. We find that spin-independent scattering arises only from the mixing of exotic squarks, or from velocity-dependent terms. Nevertheless (and contrary to the case of MSSM neutralino WIMPs), we find a class of models which cannot be detected through SI scattering, but can be detected at IceCube/DeepCore through SD scattering. We study the detection prospects for both SI and SD detection strategies for a large range of Majorana fermion WIMPless model parameters.
[ { "created": "Fri, 25 Mar 2011 19:26:03 GMT", "version": "v1" }, { "created": "Wed, 3 Aug 2011 21:30:35 GMT", "version": "v2" } ]
2011-08-09
[ [ "Fukushima", "Keita", "" ], [ "Kumar", "Jason", "" ], [ "Sandick", "Pearl", "" ] ]
We consider both velocity-dependent and velocity-independent contributions to spin-dependent (SD) and spin-independent (SI) nuclear scattering (including one-loop corrections) of WIMPless dark matter, in the case where the dark matter candidate is a Majorana fermion. We find that spin-independent scattering arises only from the mixing of exotic squarks, or from velocity-dependent terms. Nevertheless (and contrary to the case of MSSM neutralino WIMPs), we find a class of models which cannot be detected through SI scattering, but can be detected at IceCube/DeepCore through SD scattering. We study the detection prospects for both SI and SD detection strategies for a large range of Majorana fermion WIMPless model parameters.
2103.15328
Juli\'an Calle Mosquera MSc
Juli\'an Calle, Diego Restrepo, \'Oscar Zapata
Phenomenology of the Zee model for Dirac neutrinos and general neutrino interactions
14+5 pages, 6 figures and 3 tables
Phys. Rev. D 104, 015032 (2021)
10.1103/PhysRevD.104.015032
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The Zee model for Dirac neutrinos is one of the simplest models featuring one-loop Dirac neutrino masses. The interactions between the new scalars (two singly-charged fields) and neutrinos induce general neutrino interactions (GNI) which, as a generalisation of the non standard neutrino interactions, constitute an additional tool to probe models beyond the SM like this. In this work, we consider a $U(1)_{{B-L}}$ gauge symmetry as the responsible for the Diracness of the neutrinos and the radiative character of the neutrino masses. We determine the viable parameter space consistent with neutrino oscillation data, leptonic rare decays and collider constraints, and establish the most relevant experimental prospects regarding lepton flavor violation searches and GNI in future solar neutrino experiments.
[ { "created": "Mon, 29 Mar 2021 04:36:38 GMT", "version": "v1" }, { "created": "Sat, 31 Jul 2021 05:56:35 GMT", "version": "v2" } ]
2021-08-04
[ [ "Calle", "Julián", "" ], [ "Restrepo", "Diego", "" ], [ "Zapata", "Óscar", "" ] ]
The Zee model for Dirac neutrinos is one of the simplest models featuring one-loop Dirac neutrino masses. The interactions between the new scalars (two singly-charged fields) and neutrinos induce general neutrino interactions (GNI) which, as a generalisation of the non standard neutrino interactions, constitute an additional tool to probe models beyond the SM like this. In this work, we consider a $U(1)_{{B-L}}$ gauge symmetry as the responsible for the Diracness of the neutrinos and the radiative character of the neutrino masses. We determine the viable parameter space consistent with neutrino oscillation data, leptonic rare decays and collider constraints, and establish the most relevant experimental prospects regarding lepton flavor violation searches and GNI in future solar neutrino experiments.
2201.07293
Michal Praszalowicz
Maxim V. Polyakov and Michal Praszalowicz
Landscape of heavy baryons from the perspective of the chiral quark-soliton model
13 pages, 3 figures. In v2 new paragraph V.C added. References updated and added. Minor corrections including title. Version accepted in PRD
Physical Review D 105, 094004 (2022)
10.1103/PhysRevD.105.094004
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We employ the chiral quark-soliton model and the heavy quark symmetry to describe spectra of charm and beauty baryons. Heavy baryons can be classified according to the SU(3) representations of the light sector. We argue that recently discovered $\Xi_b$ states can be interpreted as negative parity excited anti-triplets or sextets, and the $\Sigma_b$ states as negative parity sextets. Consequences of such assignments for the decay patterns are discussed and also predictions of masses of the yet unmeasured sextet members are given.
[ { "created": "Tue, 18 Jan 2022 20:12:43 GMT", "version": "v1" }, { "created": "Thu, 31 Mar 2022 06:56:17 GMT", "version": "v2" } ]
2022-05-09
[ [ "Polyakov", "Maxim V.", "" ], [ "Praszalowicz", "Michal", "" ] ]
We employ the chiral quark-soliton model and the heavy quark symmetry to describe spectra of charm and beauty baryons. Heavy baryons can be classified according to the SU(3) representations of the light sector. We argue that recently discovered $\Xi_b$ states can be interpreted as negative parity excited anti-triplets or sextets, and the $\Sigma_b$ states as negative parity sextets. Consequences of such assignments for the decay patterns are discussed and also predictions of masses of the yet unmeasured sextet members are given.
0704.0959
Takumi Doi
Takumi Doi (Kentucky U., Riken BNL)
Theoretical Status of Pentaquarks
Presented at Yukawa International Seminar (YKIS) 2006 on "New Frontiers in QCD", Kyoto, Japan, 20 Nov. - 8 Dec. 2006, 4 pages
Prog.Theor.Phys.Suppl.168:45-49,2007
10.1143/PTPS.168.45
null
hep-ph
null
We review the current status of the theoretical pentaquark search from the direct QCD calculation. The works from the QCD sum rule and the lattice QCD in the literature are carefully examined. The importance of the framework which can distinguish the exotic pentaquark state (if any) from the NK scattering state is emphasized.
[ { "created": "Fri, 6 Apr 2007 23:22:54 GMT", "version": "v1" } ]
2008-11-26
[ [ "Doi", "Takumi", "", "Kentucky U., Riken BNL" ] ]
We review the current status of the theoretical pentaquark search from the direct QCD calculation. The works from the QCD sum rule and the lattice QCD in the literature are carefully examined. The importance of the framework which can distinguish the exotic pentaquark state (if any) from the NK scattering state is emphasized.
2207.09526
Valerio Bertone Dr
Valerio Bertone
Matching generalised transverse-momentum-dependent distributions onto generalised parton distributions at one loop
28 pages including references, 6 figures, accompanied by a code to reproduce the numerical results
null
10.1140/epjc/s10052-022-10863-3
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The operator definition of generalised transverse-momentum-dependent (GTMD) distributions is exploited to compute for the first time the full set of one-loop corrections to the off-forward matching functions. These functions allow one to obtain GTMDs in the perturbative regime in terms of generalised parton distributions (GPDs). In the unpolarised case, non-perturbative corrections can be incorporated using recent determinations of transverse-momentum-dependent (TMD) distributions. Evolution effects for GTMDs closely follow those for TMDs and can thus be easily accounted for up to next-to-next-to-leading logarithmic accuracy. As a by-product, the relevant one-loop anomalous dimensions are derived, confirming previous results. As a practical application, numerical results for a specific kind of GTMDs are presented, highlighting some salient features.
[ { "created": "Tue, 19 Jul 2022 19:46:58 GMT", "version": "v1" } ]
2022-11-09
[ [ "Bertone", "Valerio", "" ] ]
The operator definition of generalised transverse-momentum-dependent (GTMD) distributions is exploited to compute for the first time the full set of one-loop corrections to the off-forward matching functions. These functions allow one to obtain GTMDs in the perturbative regime in terms of generalised parton distributions (GPDs). In the unpolarised case, non-perturbative corrections can be incorporated using recent determinations of transverse-momentum-dependent (TMD) distributions. Evolution effects for GTMDs closely follow those for TMDs and can thus be easily accounted for up to next-to-next-to-leading logarithmic accuracy. As a by-product, the relevant one-loop anomalous dimensions are derived, confirming previous results. As a practical application, numerical results for a specific kind of GTMDs are presented, highlighting some salient features.
hep-ph/9611465
Smirnov Alexei
Alexei Yu. Smirnov
Neutrino Masses and Oscillations
19 pages, LaTeX, psfig.sty, stwol.sty, 9 figures included. Plenary talk given at 28th International Conference on High energy physics, 25 - 31 July 1996, Warsaw, Poland. Formulas of sect. 4.5 have been corrected
null
null
IC/96/249
hep-ph
null
New effects related to refraction of neutrinos in different media are reviewed and implication of the effects to neutrino mass and mixing are discussed. Patterns of neutrino masses and mixing implied by existing hints/bounds are described. Recent results on neutrino mass generation are presented. They include neutrino masses in SO(10) GUT's and models with anomalous $U(1)$, generation of neutrino mass via neutrino-neutralino mixing, models of sterile neutrino.
[ { "created": "Wed, 27 Nov 1996 18:13:23 GMT", "version": "v1" }, { "created": "Mon, 2 Dec 1996 11:15:55 GMT", "version": "v2" } ]
2008-02-03
[ [ "Smirnov", "Alexei Yu.", "" ] ]
New effects related to refraction of neutrinos in different media are reviewed and implication of the effects to neutrino mass and mixing are discussed. Patterns of neutrino masses and mixing implied by existing hints/bounds are described. Recent results on neutrino mass generation are presented. They include neutrino masses in SO(10) GUT's and models with anomalous $U(1)$, generation of neutrino mass via neutrino-neutralino mixing, models of sterile neutrino.
2007.00673
Anke Biek\"otter
Anke Biek\"otter, Mikael Chala, Michael Spannowsky
The effective field theory of low scale see-saw at colliders
updated to published version; 26 pages, 6 figures
Eur. Phys. J. C 80, 743 (2020)
10.1140/epjc/s10052-020-8339-2
IPPP/20/25
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the Standard Model effective field theory ($\nu$SMEFT) extended with operators involving right-handed neutrinos, focussing on the regime where the right-handed neutrinos decay promptly on collider scales to a photon and a Standard Model neutrino. This scenario arises naturally for right-handed neutrinos with masses of the order $m_N \sim 0.1 \dots 10\, \text{GeV}$. We limit the relevant dimension-six operator coefficients using LEP and LHC searches with photons and missing energy in the final state as well as pion and tau decays. While bounds on new physics contributions are generally in the TeV scale for order one operator coefficients, some coefficients, however, remain very poorly constrained or even entirely evade bounds from current data. Consequently, we identify such weakly constrained scenarios and propose new searches for rare top and tau decays involving photons to probe potential new physics in the $\nu$SMEFT parameter space. Our analysis highlights the importance of performing dedicated searches for new rare tau and top decays.
[ { "created": "Wed, 1 Jul 2020 18:00:03 GMT", "version": "v1" }, { "created": "Fri, 14 Aug 2020 17:48:29 GMT", "version": "v2" } ]
2021-02-03
[ [ "Biekötter", "Anke", "" ], [ "Chala", "Mikael", "" ], [ "Spannowsky", "Michael", "" ] ]
We study the Standard Model effective field theory ($\nu$SMEFT) extended with operators involving right-handed neutrinos, focussing on the regime where the right-handed neutrinos decay promptly on collider scales to a photon and a Standard Model neutrino. This scenario arises naturally for right-handed neutrinos with masses of the order $m_N \sim 0.1 \dots 10\, \text{GeV}$. We limit the relevant dimension-six operator coefficients using LEP and LHC searches with photons and missing energy in the final state as well as pion and tau decays. While bounds on new physics contributions are generally in the TeV scale for order one operator coefficients, some coefficients, however, remain very poorly constrained or even entirely evade bounds from current data. Consequently, we identify such weakly constrained scenarios and propose new searches for rare top and tau decays involving photons to probe potential new physics in the $\nu$SMEFT parameter space. Our analysis highlights the importance of performing dedicated searches for new rare tau and top decays.
hep-ph/9412218
Katri Huitu
K. Huitu, J. Maalampi, M. Raidal
Supersymmetric Left-Right Model and its Phenomenological Implications
5 pages, no figures, talk given by Katri Huitu at "Physics from Planck scale to electroweak scale", Warsaw, Poland 21-24 September 1994
null
null
HU-SEFT R 1994-18
hep-ph
null
We review here our study of a supersymmetric left-right model (SLRM). In the model the $R$-parity is spontaneously broken. Phenomenologically novel feature of the model is the occurrance of the doubly charged particles in the Higgs sector, which are possibly light enough to be seen in the next linear collider. Detection of the doubly charged higgsinos in the next linear collider is discussed.
[ { "created": "Fri, 2 Dec 1994 16:12:53 GMT", "version": "v1" } ]
2007-05-23
[ [ "Huitu", "K.", "" ], [ "Maalampi", "J.", "" ], [ "Raidal", "M.", "" ] ]
We review here our study of a supersymmetric left-right model (SLRM). In the model the $R$-parity is spontaneously broken. Phenomenologically novel feature of the model is the occurrance of the doubly charged particles in the Higgs sector, which are possibly light enough to be seen in the next linear collider. Detection of the doubly charged higgsinos in the next linear collider is discussed.
1304.6066
Felix Kahlhoefer
Mads T. Frandsen (CP3-Origins), Felix Kahlhoefer (Oxford), Christopher McCabe (IPPP), Subir Sarkar (Oxford), and Kai Schmidt-Hoberg (CERN)
The unbearable lightness of being: CDMS versus XENON
15 pages, 7 figures. v2: minor changes, references added - accepted for publication in JCAP
JCAP 1307 (2013) 023
10.1088/1475-7516/2013/07/023
CP3-Origins-2013-012 DNRF90 , DIAS-2013-12, OUTP-13-09P, IPPP/13/23, DCPT/13/46, CERN-PH-TH/2013-081
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The CDMS-II collaboration has reported 3 events in a Si detector, which are consistent with being nuclear recoils due to scattering of Galactic dark matter particles with a mass of about 8.6 GeV and a cross-section on neutrons of about 2 x 10^-41 cm^2. While a previous result from the XENON10 experiment has supposedly ruled out such particles as dark matter, we find by reanalysing the XENON10 data that this is not the case. Some tension remains however with the upper limit placed by the XENON100 experiment, independently of astrophysical uncertainties concerning the Galactic dark matter distribution. We explore possible ways of ameliorating this tension by altering the properties of dark matter interactions. Nevertheless, even with standard couplings, light dark matter is consistent with both CDMS and XENON10/100.
[ { "created": "Mon, 22 Apr 2013 19:28:08 GMT", "version": "v1" }, { "created": "Mon, 1 Jul 2013 13:19:10 GMT", "version": "v2" } ]
2013-08-05
[ [ "Frandsen", "Mads T.", "", "CP3-Origins" ], [ "Kahlhoefer", "Felix", "", "Oxford" ], [ "McCabe", "Christopher", "", "IPPP" ], [ "Sarkar", "Subir", "", "Oxford" ], [ "Schmidt-Hoberg", "Kai", "", "CERN" ] ]
The CDMS-II collaboration has reported 3 events in a Si detector, which are consistent with being nuclear recoils due to scattering of Galactic dark matter particles with a mass of about 8.6 GeV and a cross-section on neutrons of about 2 x 10^-41 cm^2. While a previous result from the XENON10 experiment has supposedly ruled out such particles as dark matter, we find by reanalysing the XENON10 data that this is not the case. Some tension remains however with the upper limit placed by the XENON100 experiment, independently of astrophysical uncertainties concerning the Galactic dark matter distribution. We explore possible ways of ameliorating this tension by altering the properties of dark matter interactions. Nevertheless, even with standard couplings, light dark matter is consistent with both CDMS and XENON10/100.
1306.3441
Masafumi Kurachi
Masafumi Kurachi, Shinya Matsuzaki and Koichi Yamawaki
Gluonic Effects on g-2: Holographic View
14 pages, 7 figures; v2: version accepted by PRD
null
10.1103/PhysRevD.88.055001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study "gluonic effects" (gluon condensation effects) on the hadronic leading order (HLO) contributions to the anomalous magnetic moment (g-2) of leptons, based on a holographic model having explicit gluonic mode introduced for consistency with the operator product expansion of QCD. We find gluonic enhancement of HLO contributions to the muon g-2 by about 6%, which nicely fills in the gap between the holographic estimate without gluonic effects and the phenomenological one using the experimental data as inputs. Similar calculations including the gluonic effects for the electron and the tau lepton g-2 are also carried out in good agreement with the phenomenological estimates. We then apply our holographic estimate to the Walking Technicolor (WTC) where large techni-gluonic effects were shown to be vital for the Technidilaton, (pseudo) Nambu-Goldstone boson of the (approximate) scale symmetry of WTC, to be naturally as light as 125 GeV. It is shown that the value of the techni-HLO contributions to the muon g-2 is 10-100 times enhanced by inclusion of the same amount of the gluonic effects as that realizing the 125 GeV Technidilaton, although such an enhanced techni-HLO contribution is still negligibly small compared with the current deviation of the Standard Model prediction of the muon g-2 from the experiments. The techni-HLO contributions to the tau lepton g-2 is also discussed, suggesting a possible phenomenological relevance to be tested by the future experiments.
[ { "created": "Fri, 14 Jun 2013 16:21:39 GMT", "version": "v1" }, { "created": "Thu, 22 Aug 2013 22:36:14 GMT", "version": "v2" } ]
2013-09-11
[ [ "Kurachi", "Masafumi", "" ], [ "Matsuzaki", "Shinya", "" ], [ "Yamawaki", "Koichi", "" ] ]
We study "gluonic effects" (gluon condensation effects) on the hadronic leading order (HLO) contributions to the anomalous magnetic moment (g-2) of leptons, based on a holographic model having explicit gluonic mode introduced for consistency with the operator product expansion of QCD. We find gluonic enhancement of HLO contributions to the muon g-2 by about 6%, which nicely fills in the gap between the holographic estimate without gluonic effects and the phenomenological one using the experimental data as inputs. Similar calculations including the gluonic effects for the electron and the tau lepton g-2 are also carried out in good agreement with the phenomenological estimates. We then apply our holographic estimate to the Walking Technicolor (WTC) where large techni-gluonic effects were shown to be vital for the Technidilaton, (pseudo) Nambu-Goldstone boson of the (approximate) scale symmetry of WTC, to be naturally as light as 125 GeV. It is shown that the value of the techni-HLO contributions to the muon g-2 is 10-100 times enhanced by inclusion of the same amount of the gluonic effects as that realizing the 125 GeV Technidilaton, although such an enhanced techni-HLO contribution is still negligibly small compared with the current deviation of the Standard Model prediction of the muon g-2 from the experiments. The techni-HLO contributions to the tau lepton g-2 is also discussed, suggesting a possible phenomenological relevance to be tested by the future experiments.
1011.6571
Antoni Szczurek
Antoni Szczurek
Diffractive exclusive production of Higgs boson and heavy quark pairs at high energy proton-proton collisions
4 pages, 5 figures, invited talk at QCHS IX, Madrid, August 30th, September 3rd
null
10.1063/1.3575095
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss exclusive double diffractive (EDD) production of Higgs boson and heavy quark - heavy antiquark pairs at high energies. Differential distributions for $c \bar c$ at $\sqrt{s}$ = 1.96 GeV and for $b \bar b$ at $\sqrt{s}$ = 14 TeV are shown and discussed. Irreducible leading-order $b \bar b $ background to Higgs production is calculated in several kinematical variables. The signal-to-background ratio is shown and several improvements are suggested by imposing cuts on $b$ ($\bar b$) transverse momenta and rapidities.
[ { "created": "Tue, 30 Nov 2010 15:13:14 GMT", "version": "v1" } ]
2015-05-20
[ [ "Szczurek", "Antoni", "" ] ]
We discuss exclusive double diffractive (EDD) production of Higgs boson and heavy quark - heavy antiquark pairs at high energies. Differential distributions for $c \bar c$ at $\sqrt{s}$ = 1.96 GeV and for $b \bar b$ at $\sqrt{s}$ = 14 TeV are shown and discussed. Irreducible leading-order $b \bar b $ background to Higgs production is calculated in several kinematical variables. The signal-to-background ratio is shown and several improvements are suggested by imposing cuts on $b$ ($\bar b$) transverse momenta and rapidities.
1004.3756
Stephen King
Sandhya Choubey, S. F. King, Manimala Mitra
On the Vanishing of the CP Asymmetry in Leptogenesis due to Form Dominance
19 pages
Phys.Rev.D82:033002,2010
10.1103/PhysRevD.82.033002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We emphasize that the vanishing of the CP asymmetry in leptogenesis, previously observed for models with tri-bimaximal mixing and family symmetry, may be traced to a property of the type I see-saw mechanism satisfied by such models known as Form Dominance, corresponding to the case of a diagonal Casas-Ibarra R-matrix. Form Dominance leads to vanishing flavour-dependent CP asymmetries irrespective of whether one has tri-bimaximal mixing or a family symmetry. Successful leptogenesis requires violation of Form Dominance, but not necessarily violation of tri bimaximal mixing. This may be achieved in models where the family symmetry responsible for tri-bimaximal mixing is implemented indirectly and a strong neutrino mass hierarchy is present with the Form Dominance broken only softly by the right-handed neutrino responsible for the lightest neutrino mass, as in constrained sequential dominance.
[ { "created": "Wed, 21 Apr 2010 17:50:00 GMT", "version": "v1" } ]
2014-11-20
[ [ "Choubey", "Sandhya", "" ], [ "King", "S. F.", "" ], [ "Mitra", "Manimala", "" ] ]
We emphasize that the vanishing of the CP asymmetry in leptogenesis, previously observed for models with tri-bimaximal mixing and family symmetry, may be traced to a property of the type I see-saw mechanism satisfied by such models known as Form Dominance, corresponding to the case of a diagonal Casas-Ibarra R-matrix. Form Dominance leads to vanishing flavour-dependent CP asymmetries irrespective of whether one has tri-bimaximal mixing or a family symmetry. Successful leptogenesis requires violation of Form Dominance, but not necessarily violation of tri bimaximal mixing. This may be achieved in models where the family symmetry responsible for tri-bimaximal mixing is implemented indirectly and a strong neutrino mass hierarchy is present with the Form Dominance broken only softly by the right-handed neutrino responsible for the lightest neutrino mass, as in constrained sequential dominance.
hep-ph/9810359
Robert Peschanski
H.Navelet and R. Peschanski (Saclay)
Non-forward double Pomeron exchange in QCD
latex file, 7 pages. no figure, needs sprocl.sty. Contribution to the $th Workshop on QCD, paris, 1-6 June 1998
null
null
null
hep-ph
null
We derive the analytic expression of the two one-loop dipole contributions to the elastic 4-gluon amplitude in QCD for arbitrary transverse momentum. The first one corresponds to the double QCD pomeron exchange, the other to an order $\alpha^2$ correction to one-pomeron exchange.
[ { "created": "Wed, 14 Oct 1998 16:25:41 GMT", "version": "v1" } ]
2007-05-23
[ [ "Navelet", "H.", "", "Saclay" ], [ "Peschanski", "R.", "", "Saclay" ] ]
We derive the analytic expression of the two one-loop dipole contributions to the elastic 4-gluon amplitude in QCD for arbitrary transverse momentum. The first one corresponds to the double QCD pomeron exchange, the other to an order $\alpha^2$ correction to one-pomeron exchange.
2312.05032
Xiang-Peng Wang
Nora Brambilla and Xiang-Peng Wang
Off-lightcone Wilson-line operators in gradient flow
Published version, including updating footnote 5 and Note Added for comparison with existing calculation, and correcting several text typos
JHEP 06 (2024) 210
10.1007/JHEP06(2024)210
null
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Off-lightcone Wilson-line operators are constructed using local operators connected by time-like or space-like Wilson lines, which ensure gauge invariance. Off-lightcone Wilson-line operators have broad applications in various contexts. For instance, space-like Wilson-line operators play a crucial role in determining quasi-distribution functions (quasi-PDFs), while time-like Wilson-line operators are essential for understanding quarkonium decay and production within the potential non-relativistic QCD (pNRQCD) framework. In this work, we establish a systematic approach for calculating the matching from the gradient-flow scheme to the $\overline{\rm MS}$ scheme in the limit of small flow time for off-lightcone Wilson-line operators. By employing the one-dimensional auxiliary-field formalism, we simplify the matching procedure, reducing it to the matching of local current operators. We provide one-loop level matching coefficients for these local current operators. For the case of hadronic matrix element related to the quark quasi-PDFs, we show at one-loop level that the finite flow time effect is very small as long as the flow radius is smaller than the physical distance $z$, which is usually satisfied in lattice gradient flow computations. Applications include lattice gradient flow computations of quark/gluon quasi-PDFs, gluonic correlators related to quarkonium decay and production in pNRQCD, and spin-dependent potentials in terms of chromoelectric and chromomagnetic field insertions into a Wilson loop.
[ { "created": "Fri, 8 Dec 2023 13:25:28 GMT", "version": "v1" }, { "created": "Tue, 7 May 2024 09:22:39 GMT", "version": "v2" }, { "created": "Thu, 18 Jul 2024 18:06:02 GMT", "version": "v3" } ]
2024-07-22
[ [ "Brambilla", "Nora", "" ], [ "Wang", "Xiang-Peng", "" ] ]
Off-lightcone Wilson-line operators are constructed using local operators connected by time-like or space-like Wilson lines, which ensure gauge invariance. Off-lightcone Wilson-line operators have broad applications in various contexts. For instance, space-like Wilson-line operators play a crucial role in determining quasi-distribution functions (quasi-PDFs), while time-like Wilson-line operators are essential for understanding quarkonium decay and production within the potential non-relativistic QCD (pNRQCD) framework. In this work, we establish a systematic approach for calculating the matching from the gradient-flow scheme to the $\overline{\rm MS}$ scheme in the limit of small flow time for off-lightcone Wilson-line operators. By employing the one-dimensional auxiliary-field formalism, we simplify the matching procedure, reducing it to the matching of local current operators. We provide one-loop level matching coefficients for these local current operators. For the case of hadronic matrix element related to the quark quasi-PDFs, we show at one-loop level that the finite flow time effect is very small as long as the flow radius is smaller than the physical distance $z$, which is usually satisfied in lattice gradient flow computations. Applications include lattice gradient flow computations of quark/gluon quasi-PDFs, gluonic correlators related to quarkonium decay and production in pNRQCD, and spin-dependent potentials in terms of chromoelectric and chromomagnetic field insertions into a Wilson loop.
hep-ph/0603082
Jochum van der Bij
J. J. van der Bij
The minimal non-minimal standard model
In memory of Alfred Hill
Phys.Lett. B636 (2006) 56-59
10.1016/j.physletb.2006.03.018
Freiburg-THEP-06/02
hep-ph
null
In this letter I discuss a class of extensions of the standard model that have a minimal number of possible parameters, but can in principle explain dark matter and inflation. It is pointed out that the so-called new minimal standard model contains a large number of parameters that can be put to zero, without affecting the renormalizability of the model. With the extra restrictions one might call it the minimal (new) non minimal standard model (MNMSM). A few hidden discrete variables are present. It is argued that the inflaton should be higher-dimensional. Experimental consequences for the LHC and the ILC are discussed.
[ { "created": "Fri, 10 Mar 2006 16:24:16 GMT", "version": "v1" } ]
2009-11-11
[ [ "van der Bij", "J. J.", "" ] ]
In this letter I discuss a class of extensions of the standard model that have a minimal number of possible parameters, but can in principle explain dark matter and inflation. It is pointed out that the so-called new minimal standard model contains a large number of parameters that can be put to zero, without affecting the renormalizability of the model. With the extra restrictions one might call it the minimal (new) non minimal standard model (MNMSM). A few hidden discrete variables are present. It is argued that the inflaton should be higher-dimensional. Experimental consequences for the LHC and the ILC are discussed.
1712.07510
Kasper Jens Larsen
Alessandro Georgoudis, Kasper J. Larsen, Yang Zhang
Cristal and Azurite: new tools for integration-by-parts reductions
7 pages, 3 figures. Contribution to the proceedings of RADCOR 2017, 25-29 September 2017, St. Gilgen, Austria
PoS RADCOR2017 (2017) 020
10.22323/1.290.0020
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Scattering amplitudes computed at a fixed loop order, along with any other object computed in perturbative quantum field theory, can be expressed as a linear combination of a finite basis of loop integrals. To compute loop amplitudes in practice, such a basis of integrals must be determined. We discuss Azurite (A ZURich-bred method for finding master InTEgrals), a publicly available package for finding bases of loop integrals. We also discuss Cristal (Complete Reduction of IntegralS Through All Loops), a future package that produces the complete integration-by-parts reductions.
[ { "created": "Wed, 20 Dec 2017 15:00:22 GMT", "version": "v1" } ]
2018-10-04
[ [ "Georgoudis", "Alessandro", "" ], [ "Larsen", "Kasper J.", "" ], [ "Zhang", "Yang", "" ] ]
Scattering amplitudes computed at a fixed loop order, along with any other object computed in perturbative quantum field theory, can be expressed as a linear combination of a finite basis of loop integrals. To compute loop amplitudes in practice, such a basis of integrals must be determined. We discuss Azurite (A ZURich-bred method for finding master InTEgrals), a publicly available package for finding bases of loop integrals. We also discuss Cristal (Complete Reduction of IntegralS Through All Loops), a future package that produces the complete integration-by-parts reductions.
hep-ph/9312291
David London
C.P. Burgess, S. Godfrey, H. K\"onig, D. London and I. Maksymyk
Model-Independent Global Constraints on New Physics
plain TeX, 68 pages, 2 figures (postscript files appended), McGill-93/12, NEIPH-93-008, OCIP/C-93-6, UQAM-PHE-93/08, UdeM-LPN-TH-93-155
Phys.Rev. D49 (1994) 6115-6147
10.1103/PhysRevD.49.6115
null
hep-ph
null
Using effective-lagrangian techniques we perform a systematic survey of the lowest-dimension effective interactions through which heavy physics might manifest itself in present experiments. We do not restrict ourselves to special classes of effective interactions (such as `oblique' corrections). We compute the effects of these operators on all currently well-measured electroweak observables, both at low energies and at the $Z$ resonance, and perform a global fit to their coefficients. Despite the fact that a great many operators arise in our survey, we find that most are quite strongly bounded by the current data. We use our survey to systematically identify those effective interactions which are {\it not} well-bounded by the data -- these could very well include large new-physics contributions. Our results may also be used to efficiently confront specific models for new physics with the data, as we illustrate with an example.
[ { "created": "Wed, 15 Dec 1993 20:51:06 GMT", "version": "v1" } ]
2009-10-22
[ [ "Burgess", "C. P.", "" ], [ "Godfrey", "S.", "" ], [ "König", "H.", "" ], [ "London", "D.", "" ], [ "Maksymyk", "I.", "" ] ]
Using effective-lagrangian techniques we perform a systematic survey of the lowest-dimension effective interactions through which heavy physics might manifest itself in present experiments. We do not restrict ourselves to special classes of effective interactions (such as `oblique' corrections). We compute the effects of these operators on all currently well-measured electroweak observables, both at low energies and at the $Z$ resonance, and perform a global fit to their coefficients. Despite the fact that a great many operators arise in our survey, we find that most are quite strongly bounded by the current data. We use our survey to systematically identify those effective interactions which are {\it not} well-bounded by the data -- these could very well include large new-physics contributions. Our results may also be used to efficiently confront specific models for new physics with the data, as we illustrate with an example.
hep-ph/9801387
Brian A. Woodahl
Ephraim Fischbach and Brian Woodahl (Purdue University)
Neutrino-Exchange Interactions in 1-, 2-, and 3-Dimensions
LaTeX, 10 pages
null
null
PURD-TH-98-02
hep-ph
null
We examine several recent calculations of the self-energy of a neutron star arising from neutrino-exchange. It is shown that the results of Abada, et al. in 1+1 dimensions have no bearing on a 3-dimensional neutron star, since the criticality parameter (Gf N)/R^2 is always much smaller than unity in 1+1 dimensions. The calculation of Kiers and Tytgat in 3-dimensions is shown to disagree with the lowest order 2-body contribution, which is known exactly. This discrepancy raises the possibility that the description of a neutron star as a continuous medium may be inappropriate when calculating higher-order many-body effects. We conclude that none of the recent calculations contradict the earlier claims that the neutrino-exchange contributions to the self-energy of a neutron star are unphysically large, when calculated in the standard model. The implication of this result, that neutrinos must have a non-zero mass, m > 0.4 eV, remains intact.
[ { "created": "Thu, 22 Jan 1998 00:09:42 GMT", "version": "v1" } ]
2007-05-23
[ [ "Fischbach", "Ephraim", "", "Purdue University" ], [ "Woodahl", "Brian", "", "Purdue University" ] ]
We examine several recent calculations of the self-energy of a neutron star arising from neutrino-exchange. It is shown that the results of Abada, et al. in 1+1 dimensions have no bearing on a 3-dimensional neutron star, since the criticality parameter (Gf N)/R^2 is always much smaller than unity in 1+1 dimensions. The calculation of Kiers and Tytgat in 3-dimensions is shown to disagree with the lowest order 2-body contribution, which is known exactly. This discrepancy raises the possibility that the description of a neutron star as a continuous medium may be inappropriate when calculating higher-order many-body effects. We conclude that none of the recent calculations contradict the earlier claims that the neutrino-exchange contributions to the self-energy of a neutron star are unphysically large, when calculated in the standard model. The implication of this result, that neutrinos must have a non-zero mass, m > 0.4 eV, remains intact.
1211.6911
Robi Peschanski
Robi Peschanski
Dynamical entropy of dense QCD states
Version mildly updated to match publication. Adding a discussion of the k_T factorization formula. Results and conclusions unchanged
Phys. Rev. D 87, 034042 (2013)
10.1103/PhysRevD.87.034042
null
hep-ph cond-mat.stat-mech hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss dense states of QCD matter formed in high-energy hadronic and heavy-ion collisions from the point of view of statistical physics of non-equilibrium processes. For this sake, we first propose a formulation of the dynamical entropy of dense QCD states in the "saturation regime" leading to a color glass condensate (CGC). The statistical physics description amounts to describe the modification of the color correlation length with energy as a compression process for which non equilibrium thermodynamic properties are applicable. We derive an expression of the dynamical entropy in terms of the rapidity evolution of the unintegrated gluon distributions in the colliding nuclei, verifying suitable positivity and irreversibility properties. We extend this approach to the initial pre-equilibrium (glasma) state of an heavy-ion collision. It allows for a definition of the initial entropy before the evolution towards the hydrodynamic regime as a function of the glasma correlation length and an overlap parameter characterizing the low-momentum spectrum of the glasma state. This initial entropy, by extension to the N=4 SYM theory, is then matched as the key input parameter to the strong coupling evaluation of thermalization towards the hydrodynamic regime based on the AdS/CFT correspondence. It thus allows to cast a bridge between the weak and strong coupling phases of an heavy-ion reaction.
[ { "created": "Thu, 29 Nov 2012 13:38:16 GMT", "version": "v1" }, { "created": "Tue, 26 Mar 2013 06:19:10 GMT", "version": "v2" } ]
2013-03-27
[ [ "Peschanski", "Robi", "" ] ]
We discuss dense states of QCD matter formed in high-energy hadronic and heavy-ion collisions from the point of view of statistical physics of non-equilibrium processes. For this sake, we first propose a formulation of the dynamical entropy of dense QCD states in the "saturation regime" leading to a color glass condensate (CGC). The statistical physics description amounts to describe the modification of the color correlation length with energy as a compression process for which non equilibrium thermodynamic properties are applicable. We derive an expression of the dynamical entropy in terms of the rapidity evolution of the unintegrated gluon distributions in the colliding nuclei, verifying suitable positivity and irreversibility properties. We extend this approach to the initial pre-equilibrium (glasma) state of an heavy-ion collision. It allows for a definition of the initial entropy before the evolution towards the hydrodynamic regime as a function of the glasma correlation length and an overlap parameter characterizing the low-momentum spectrum of the glasma state. This initial entropy, by extension to the N=4 SYM theory, is then matched as the key input parameter to the strong coupling evaluation of thermalization towards the hydrodynamic regime based on the AdS/CFT correspondence. It thus allows to cast a bridge between the weak and strong coupling phases of an heavy-ion reaction.
hep-ph/9209212
Fred Cooper
Fred Cooper
Dynamical Approach to Pair Production from Strong Fields
28 pages, LA-UR-92-2753
null
null
null
hep-ph
null
Lectures Given at the Nato Advanced Study Institute-Particle Production in Highly Excited Matter Il Ciocco, Italy July 1992 figure available on request. Input harvmac.tex
[ { "created": "Fri, 4 Sep 1992 17:28:06 GMT", "version": "v1" } ]
2007-05-23
[ [ "Cooper", "Fred", "" ] ]
Lectures Given at the Nato Advanced Study Institute-Particle Production in Highly Excited Matter Il Ciocco, Italy July 1992 figure available on request. Input harvmac.tex
hep-ph/0703298
Andrea Beraudo
W.M. Alberico, A. Beraudo, A. Czerska, P. Czerski, A. Molinari
Meson Screening Masses in the Interacting QCD Plasma
21 pages, 12 figures, submitted to Nucl.Phys.A
Nucl.Phys.A792:152-169,2007
10.1016/j.nuclphysa.2007.04.019
null
hep-ph
null
The meson screening mass in the pseudoscalar channel is calculated from the momentum dependent meson spectral function, using HTL fermionic propagators. A careful subtraction procedure is required to get an UV finite result. It is shown that in the whole range of temperatures explored here the HTL screening mass stays above the non-interacting result, slowly approaching the value $m_{\trm{scr}}=2\sqrt{\pi^2T^2+m_\infty^2}$, where $m_\infty^2$ is the HTL asymptotic thermal quark mass. Our analysis leads to a better understanding of the excitations of QGP at sufficiently large temperatures and may be of relevance for interpreting lattice results.
[ { "created": "Wed, 28 Mar 2007 15:30:54 GMT", "version": "v1" } ]
2008-11-26
[ [ "Alberico", "W. M.", "" ], [ "Beraudo", "A.", "" ], [ "Czerska", "A.", "" ], [ "Czerski", "P.", "" ], [ "Molinari", "A.", "" ] ]
The meson screening mass in the pseudoscalar channel is calculated from the momentum dependent meson spectral function, using HTL fermionic propagators. A careful subtraction procedure is required to get an UV finite result. It is shown that in the whole range of temperatures explored here the HTL screening mass stays above the non-interacting result, slowly approaching the value $m_{\trm{scr}}=2\sqrt{\pi^2T^2+m_\infty^2}$, where $m_\infty^2$ is the HTL asymptotic thermal quark mass. Our analysis leads to a better understanding of the excitations of QGP at sufficiently large temperatures and may be of relevance for interpreting lattice results.
hep-ph/9810444
masanori Miyama
S. Hino, M. Hirai, S. Kumano, and M. Miyama (Saga University)
Transversity distributions and spin asymmetries
1+3 pages, LATEX with amsmath.sty, epsfig.sty, wrapfig.sty, and sprocl.sty, 2 eps figures. Talk given at the 13th International Symposium on High Energy Spin Physics. Protvino, Russia, Sept. 8 -- 12, 1998, to be published in proceedings by the World Scientific. Complete postscript file including the figures is also available at http://www2.cc.saga-u.ac.jp/saga-u/riko/physics/quantum1/structure.html Email: 97sm16@edu.cc.saga-u.ac.jp, 98td25@edu.cc.saga-u.ac.jp, kumanos@cc.saga-u.ac.jp, 96td25@edu.cc.saga-u.ac.jp
null
null
SAGA-HE-140-98
hep-ph hep-ex nucl-th
null
We discuss transversity distributions and transverse spin asymmetries. First, $Q^2$ evolution results are shown for transversity and longitudinally polarized distributions. Second, the antiquark flavor asymmetry $\Delta_{_T} \bar u/\Delta_{_T} \bar d$ is discussed in two different descriptions, a meson-cloud model and an exclusion model. Both calculations produce a significant $\Delta_T \bar d$ excess over $\Delta_{_T} \bar u$. Third, we explain general formalism of the polarized proton-deuteron Drell-Yan processes. This study is partly intended to find the asymmetry $\Delta_{_T} \bar u/\Delta_{_T} \bar d$ by the p-d asymmetry. However, the existence of tensor structure in the deuteron produces a number of new structure functions. There exist 108 structure functions and 22 ones even after integrating the cross section over the virtual-photon transverse momentum $\vec Q_T$.
[ { "created": "Thu, 22 Oct 1998 05:13:08 GMT", "version": "v1" } ]
2007-05-23
[ [ "Hino", "S.", "", "Saga University" ], [ "Hirai", "M.", "", "Saga University" ], [ "Kumano", "S.", "", "Saga University" ], [ "Miyama", "M.", "", "Saga University" ] ]
We discuss transversity distributions and transverse spin asymmetries. First, $Q^2$ evolution results are shown for transversity and longitudinally polarized distributions. Second, the antiquark flavor asymmetry $\Delta_{_T} \bar u/\Delta_{_T} \bar d$ is discussed in two different descriptions, a meson-cloud model and an exclusion model. Both calculations produce a significant $\Delta_T \bar d$ excess over $\Delta_{_T} \bar u$. Third, we explain general formalism of the polarized proton-deuteron Drell-Yan processes. This study is partly intended to find the asymmetry $\Delta_{_T} \bar u/\Delta_{_T} \bar d$ by the p-d asymmetry. However, the existence of tensor structure in the deuteron produces a number of new structure functions. There exist 108 structure functions and 22 ones even after integrating the cross section over the virtual-photon transverse momentum $\vec Q_T$.
1408.5657
Vo Quoc Phong
Vo Quoc Phong, Hoang Ngoc Long, Vo Thanh Van, Nguyen Chi Thanh
Electroweak sphalerons in the reduced minimal 3-3-1 model
13 pages, 3 figures
Phys.Rev.D90,085019(2014)
10.1103/PhysRevD.90.085019
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the electroweak sphaleron rates in the reduced minimal 3-3-1 (RM331) model. In the context of the early Universe, this model undergoes a sequence of two first-order phase transitions, $SU(3) \rightarrow SU(2)$ at the TeV scale and $SU(2)\rightarrow U(1)$ at the $10^2$ GeV scale, as the Universe cools down from the hot big bang. By a thin-wall approximation, we show that for each phase transition in this sequence, the sphaleron rate is larger than the cosmological expansion rate at temperatures higher than the critical temperature, and after the phase transition, the sphaleron process is decoupled. This may provide baryon-number violation (B violation) necessary for baryogenesis in the relationship with nonequilibrium physics in the early Universe.
[ { "created": "Mon, 25 Aug 2014 04:01:55 GMT", "version": "v1" }, { "created": "Tue, 7 Oct 2014 10:13:18 GMT", "version": "v2" }, { "created": "Tue, 21 Oct 2014 16:49:38 GMT", "version": "v3" } ]
2015-06-22
[ [ "Phong", "Vo Quoc", "" ], [ "Long", "Hoang Ngoc", "" ], [ "Van", "Vo Thanh", "" ], [ "Thanh", "Nguyen Chi", "" ] ]
We calculate the electroweak sphaleron rates in the reduced minimal 3-3-1 (RM331) model. In the context of the early Universe, this model undergoes a sequence of two first-order phase transitions, $SU(3) \rightarrow SU(2)$ at the TeV scale and $SU(2)\rightarrow U(1)$ at the $10^2$ GeV scale, as the Universe cools down from the hot big bang. By a thin-wall approximation, we show that for each phase transition in this sequence, the sphaleron rate is larger than the cosmological expansion rate at temperatures higher than the critical temperature, and after the phase transition, the sphaleron process is decoupled. This may provide baryon-number violation (B violation) necessary for baryogenesis in the relationship with nonequilibrium physics in the early Universe.
1907.01014
Fredrick Olness
xFitter Developers' team: Hamed Abdolmaleki, Valerio Bertone, Daniel Britzger, Stefano Camarda, Amanda Cooper-Sarkar, Achim Geiser, Francesco Giuli, Alexander Glazov, Agnieszka Luszczak, Ivan Novikov, Fred Olness, Andrey Sapronov, Oleksandr Zenaiev
Probing the strange content of the proton with charm production in charged current at LHeC
21 pages, 19 figures. Version 2: update to EPJC version
null
null
DESY Report 19-107
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study charm production in charged-current deep-inelastic scattering (DIS) using the xFitter framework. Recent results from the LHC have focused renewed attention on the determination of the strange-quark parton distribution function (PDF) and the DIS charm process provides important complementary constraints on this quantity. We examine the current PDF uncertainty, and use LHeC pseudodata to estimate the potential improvement from this proposed facility. As xFitter implements both fixed-flavor- and variable-flavor-number schemes, we can compare the impact of these different theoretical choices; this highlights some interesting aspects of multi-scale calculations. We find that the high-statistics LHeC data covering a wide kinematic range could substantially reduce the strange PDF uncertainty.
[ { "created": "Mon, 1 Jul 2019 18:49:48 GMT", "version": "v1" }, { "created": "Sat, 5 Oct 2019 00:32:22 GMT", "version": "v2" } ]
2019-10-08
[ [ "team", "xFitter Developers'", "" ], [ ":", "", "" ], [ "Abdolmaleki", "Hamed", "" ], [ "Bertone", "Valerio", "" ], [ "Britzger", "Daniel", "" ], [ "Camarda", "Stefano", "" ], [ "Cooper-Sarkar", "Amanda", "" ], [ "Geiser", "Achim", "" ], [ "Giuli", "Francesco", "" ], [ "Glazov", "Alexander", "" ], [ "Luszczak", "Agnieszka", "" ], [ "Novikov", "Ivan", "" ], [ "Olness", "Fred", "" ], [ "Sapronov", "Andrey", "" ], [ "Zenaiev", "Oleksandr", "" ] ]
We study charm production in charged-current deep-inelastic scattering (DIS) using the xFitter framework. Recent results from the LHC have focused renewed attention on the determination of the strange-quark parton distribution function (PDF) and the DIS charm process provides important complementary constraints on this quantity. We examine the current PDF uncertainty, and use LHeC pseudodata to estimate the potential improvement from this proposed facility. As xFitter implements both fixed-flavor- and variable-flavor-number schemes, we can compare the impact of these different theoretical choices; this highlights some interesting aspects of multi-scale calculations. We find that the high-statistics LHeC data covering a wide kinematic range could substantially reduce the strange PDF uncertainty.
2205.10976
Hugues Beauchesne
Hugues Beauchesne and Cheng-Wei Chiang
Is the decay of the Higgs boson to a photon and a dark photon currently observable at the LHC?
6 pages, 1 figure, matches published version
null
10.1103/PhysRevLett.130.141801
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Many attempts have been made to observe the decay of the Higgs boson to a photon and an invisible massless dark photon. For this decay to be potentially observable at the LHC, new mediators that communicate between the Standard Model and the dark photon must exist. In this Letter, we study bounds on such mediators coming from the Higgs signal strengths, oblique parameters, electric dipole moment of the electron and unitarity. We find that the branching ratio of the Higgs boson to a photon and a dark photon is constrained to be far smaller than the sensitivity of current collider searches, thus calling for a reconsideration of current experimental efforts.
[ { "created": "Mon, 23 May 2022 00:54:27 GMT", "version": "v1" }, { "created": "Sat, 6 May 2023 03:22:43 GMT", "version": "v2" } ]
2023-05-09
[ [ "Beauchesne", "Hugues", "" ], [ "Chiang", "Cheng-Wei", "" ] ]
Many attempts have been made to observe the decay of the Higgs boson to a photon and an invisible massless dark photon. For this decay to be potentially observable at the LHC, new mediators that communicate between the Standard Model and the dark photon must exist. In this Letter, we study bounds on such mediators coming from the Higgs signal strengths, oblique parameters, electric dipole moment of the electron and unitarity. We find that the branching ratio of the Higgs boson to a photon and a dark photon is constrained to be far smaller than the sensitivity of current collider searches, thus calling for a reconsideration of current experimental efforts.
hep-ph/0411224
Tetsuo Nishikawa
Tetsuo Nishikawa, Yoshiko Kanada-En'yo, Yoshihiko Kondo and Osamu Morimatsu
Spin-3/2 pentaquark in the QCD sum rule
27 pages, 14 figures
Phys.Rev. D71 (2005) 076004
10.1103/PhysRevD.71.076004
KEK-TH-997
hep-ph
null
We study $IJ^P=0{3/2}^\pm$ and $1{3/2}^\pm$ pentaquark states with $S=+1$ in the QCD sum rule approach. The QCD sum rule for positive parity states and that for negative parity are independently derived. The sum rule suggests that there exist the $0{3/2}^-$ and the $1{3/2}^-$ states. These states may be observed as extremely narrow peaks since they can be much below the $S$-wave threshold and since the only allowed decay channels are $NK$ in $D$-wave, whose centrifugal barriers are so large that the widths are strongly suppressed. The $0{3/2}^-$ state may be assigned to the observed $\Theta^+(1540)$ and the $1{3/2}^-$ state can be a candidate for $\Theta^{++}$.
[ { "created": "Wed, 17 Nov 2004 07:50:19 GMT", "version": "v1" }, { "created": "Mon, 28 Feb 2005 08:43:33 GMT", "version": "v2" } ]
2009-11-10
[ [ "Nishikawa", "Tetsuo", "" ], [ "Kanada-En'yo", "Yoshiko", "" ], [ "Kondo", "Yoshihiko", "" ], [ "Morimatsu", "Osamu", "" ] ]
We study $IJ^P=0{3/2}^\pm$ and $1{3/2}^\pm$ pentaquark states with $S=+1$ in the QCD sum rule approach. The QCD sum rule for positive parity states and that for negative parity are independently derived. The sum rule suggests that there exist the $0{3/2}^-$ and the $1{3/2}^-$ states. These states may be observed as extremely narrow peaks since they can be much below the $S$-wave threshold and since the only allowed decay channels are $NK$ in $D$-wave, whose centrifugal barriers are so large that the widths are strongly suppressed. The $0{3/2}^-$ state may be assigned to the observed $\Theta^+(1540)$ and the $1{3/2}^-$ state can be a candidate for $\Theta^{++}$.
2401.02107
Ankur Verma
Bhaskar Dutta, Sumit Ghosh, Kevin J. Kelly, Tianjun Li, Adrian Thompson, Ankur Verma
Non-standard neutrino interactions mediated by a light scalar at DUNE
21 pages, 8 figures, 3 tables
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We investigate the effect on neutrino oscillations generated by beyond-the-standard-model interactions between neutrinos and matter. Specifically, we focus on scalar-mediated non-standard interactions (NSI) whose impact fundamentally differs from that of vector-mediated NSI. Scalar NSI contribute as corrections to the neutrino mass matrix rather than the matter potential and thereby predict distinct phenomenology from the vector-mediated ones. Similar to vector-type NSI, the presence of scalar-mediated neutrino NSI can influence measurements of oscillation parameters in long-baseline neutrino oscillation experiments, with a notable impact on CP measurement in the case of DUNE. Our study focuses on the effect of scalar NSI on neutrino oscillations, using DUNE as an example. We introduce a model-independent parameterization procedure that enables the examination of the impact of all non-zero scalar NSI parameters simultaneously. Subsequently, we convert DUNE's sensitivity to the NSI parameters into projected sensitivity concerning the parameters of a light scalar model. We compare these results with existing non-oscillation probes. Our findings reveal that the region of the light scalar parameter space sensitive to DUNE is predominantly excluded by non-oscillation probes, except for scenarios with very light mediator mass.
[ { "created": "Thu, 4 Jan 2024 07:32:54 GMT", "version": "v1" } ]
2024-01-05
[ [ "Dutta", "Bhaskar", "" ], [ "Ghosh", "Sumit", "" ], [ "Kelly", "Kevin J.", "" ], [ "Li", "Tianjun", "" ], [ "Thompson", "Adrian", "" ], [ "Verma", "Ankur", "" ] ]
We investigate the effect on neutrino oscillations generated by beyond-the-standard-model interactions between neutrinos and matter. Specifically, we focus on scalar-mediated non-standard interactions (NSI) whose impact fundamentally differs from that of vector-mediated NSI. Scalar NSI contribute as corrections to the neutrino mass matrix rather than the matter potential and thereby predict distinct phenomenology from the vector-mediated ones. Similar to vector-type NSI, the presence of scalar-mediated neutrino NSI can influence measurements of oscillation parameters in long-baseline neutrino oscillation experiments, with a notable impact on CP measurement in the case of DUNE. Our study focuses on the effect of scalar NSI on neutrino oscillations, using DUNE as an example. We introduce a model-independent parameterization procedure that enables the examination of the impact of all non-zero scalar NSI parameters simultaneously. Subsequently, we convert DUNE's sensitivity to the NSI parameters into projected sensitivity concerning the parameters of a light scalar model. We compare these results with existing non-oscillation probes. Our findings reveal that the region of the light scalar parameter space sensitive to DUNE is predominantly excluded by non-oscillation probes, except for scenarios with very light mediator mass.
2305.08050
Zhen-Xing Zhao
Xiao-Yu Sun, Fu-Wei Zhang, Yu-Ji Shi, Zhen-Xing Zhao
Revisiting $\Xi_{Q}-\Xi_{Q}^{\prime}$ mixing in QCD sum rules
13 pages, 4 figures; version accepted by EPJC
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this work, we perform a QCD sum rules analysis on the $\Xi_{Q}-\Xi_{Q}^{\prime}$ mixing. Contributions from up to dimension-6 four-quark operators are considered. However, it turns out that, only dimension-4 and dimension-5 operators contribute, which reveals the non-perturbative nature of mixing. Especially we notice that only the diagrams with the two light quarks participating in gluon exchange contribute to the mixing. Our results indicate that the mixing angle $\theta_{c}=(1.2\sim2.8)^{\circ}$ for the $Q=c$ case and $\theta_{b}=(0.28\sim0.34)^{\circ}$ for the $Q=b$ case. Our prediction of $\theta_{c}$ is consistent with the most recent Lattice QCD result within error. Such a small mixing angle seems unlikely to resolve the tension between the recent experimental measurement from Belle and Lattice QCD calculation for the semileptonic decay $\Xi_{c}^{0}\to\Xi^{-} e^{+}\nu_{e}$.
[ { "created": "Sun, 14 May 2023 03:13:08 GMT", "version": "v1" }, { "created": "Sat, 2 Dec 2023 05:32:00 GMT", "version": "v2" } ]
2023-12-05
[ [ "Sun", "Xiao-Yu", "" ], [ "Zhang", "Fu-Wei", "" ], [ "Shi", "Yu-Ji", "" ], [ "Zhao", "Zhen-Xing", "" ] ]
In this work, we perform a QCD sum rules analysis on the $\Xi_{Q}-\Xi_{Q}^{\prime}$ mixing. Contributions from up to dimension-6 four-quark operators are considered. However, it turns out that, only dimension-4 and dimension-5 operators contribute, which reveals the non-perturbative nature of mixing. Especially we notice that only the diagrams with the two light quarks participating in gluon exchange contribute to the mixing. Our results indicate that the mixing angle $\theta_{c}=(1.2\sim2.8)^{\circ}$ for the $Q=c$ case and $\theta_{b}=(0.28\sim0.34)^{\circ}$ for the $Q=b$ case. Our prediction of $\theta_{c}$ is consistent with the most recent Lattice QCD result within error. Such a small mixing angle seems unlikely to resolve the tension between the recent experimental measurement from Belle and Lattice QCD calculation for the semileptonic decay $\Xi_{c}^{0}\to\Xi^{-} e^{+}\nu_{e}$.
hep-ph/0006096
Iain Stewart
Aneesh V. Manohar, Joan Soto, and Iain W. Stewart
The renormalization group for correlated scales: one-stage versus two-stage running
9 pages, typos fixed, results and conclusions unchanged
Phys.Lett. B486 (2000) 400-405
10.1016/S0370-2693(00)00788-7
UCSD/PTH 00-14
hep-ph hep-th physics.atom-ph
null
Nonrelativistic bound states have two low energy scales, a soft scale mu_S of order mv and an ultrasoft scale mu_U of order mv^2. In two-stage running, the soft and ultrasoft scales are lowered from m to mv, and then the ultrasoft scale is lowered from mv to mv^2. In one-stage running, the two scales are lowered in a correlated way using a subtraction velocity. We compare these two methods of summing logarithms and show that only the correlated running in velocity space of the one-stage method correctly reproduces the logarithms in non-relativistic bound states in QED. The argument for one-stage running is general, and should apply to any system with correlated scales.
[ { "created": "Mon, 12 Jun 2000 22:11:49 GMT", "version": "v1" }, { "created": "Wed, 14 Jun 2000 22:25:58 GMT", "version": "v2" } ]
2009-10-31
[ [ "Manohar", "Aneesh V.", "" ], [ "Soto", "Joan", "" ], [ "Stewart", "Iain W.", "" ] ]
Nonrelativistic bound states have two low energy scales, a soft scale mu_S of order mv and an ultrasoft scale mu_U of order mv^2. In two-stage running, the soft and ultrasoft scales are lowered from m to mv, and then the ultrasoft scale is lowered from mv to mv^2. In one-stage running, the two scales are lowered in a correlated way using a subtraction velocity. We compare these two methods of summing logarithms and show that only the correlated running in velocity space of the one-stage method correctly reproduces the logarithms in non-relativistic bound states in QED. The argument for one-stage running is general, and should apply to any system with correlated scales.
2110.04110
Yang Liu
Yang Liu, Bennie F. L. Ward
New Results For the Five Point Function
13 pages, 13 figures
null
null
BU-HEPP-21-02
hep-ph hep-th
http://creativecommons.org/publicdomain/zero/1.0/
We present the new results of the computed general five-point functionby the magic spinor product method in loop integrals proposed by one (BFLW) of us. The result from the magic spinor product method agrees with that from LoopTools overall. Such encouraging agreements indicate that the magic spinor product method is a reliable approach with good efficiency and numerical stability.
[ { "created": "Fri, 8 Oct 2021 13:18:14 GMT", "version": "v1" } ]
2021-10-11
[ [ "Liu", "Yang", "" ], [ "Ward", "Bennie F. L.", "" ] ]
We present the new results of the computed general five-point functionby the magic spinor product method in loop integrals proposed by one (BFLW) of us. The result from the magic spinor product method agrees with that from LoopTools overall. Such encouraging agreements indicate that the magic spinor product method is a reliable approach with good efficiency and numerical stability.
1712.01632
Ligong Bian
Ligong Bian, Ning Chen, Yun Jiang
Higgs Pair Productions in the CP-violating Two-Higgs-Doublet Model
6 pages, presentation at the IAS Program on HEP, January 2017, Hong Kong, based on 1607.02703
Int.J.Mod.Phys. A32,1746002 (2017)
10.1142/S0217751X17460022
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The SM-like Higgs pair productions are discussed in the framework of the general CP-violating two-Higgs-doublet model, where we find the CP-violating mixing angles can be related to the Higgs self couplings. Therefore, the future experimental searches for Higgs boson pairs can be constrained by the improved precision of the electric dipole moment measurements. Based on a series constraints of the SM-like Higgs boson signal fits, the perturbative unitarity and stability bounds to the Higgs potential, and the most recent LHC searches for the heavy Higgs bosons, we suggest a set of benchmark models for the future high-energy collider searches for the Higgs pair productions. The $e^+ e^-$ colliders operating at $\sqrt{s}=$ (500 GeV, 1 TeV) are capable of measuring the Higgs cubic self couplings of the benchmark models directly. We also estimate the cross sections of the resonance contributions to the Higgs pair productions for the benchmark models at the future LHC and SppC/Fcc-hh runs.
[ { "created": "Tue, 5 Dec 2017 14:10:20 GMT", "version": "v1" } ]
2017-12-06
[ [ "Bian", "Ligong", "" ], [ "Chen", "Ning", "" ], [ "Jiang", "Yun", "" ] ]
The SM-like Higgs pair productions are discussed in the framework of the general CP-violating two-Higgs-doublet model, where we find the CP-violating mixing angles can be related to the Higgs self couplings. Therefore, the future experimental searches for Higgs boson pairs can be constrained by the improved precision of the electric dipole moment measurements. Based on a series constraints of the SM-like Higgs boson signal fits, the perturbative unitarity and stability bounds to the Higgs potential, and the most recent LHC searches for the heavy Higgs bosons, we suggest a set of benchmark models for the future high-energy collider searches for the Higgs pair productions. The $e^+ e^-$ colliders operating at $\sqrt{s}=$ (500 GeV, 1 TeV) are capable of measuring the Higgs cubic self couplings of the benchmark models directly. We also estimate the cross sections of the resonance contributions to the Higgs pair productions for the benchmark models at the future LHC and SppC/Fcc-hh runs.
hep-ph/0501015
Zhi-Gang Wang
Zhi-Gang Wang (NCEPU), Wei-Min Yang (USTC), Shao-Long Wan (USTC)
Reanalysis the pentaquark $\Theta^+(1540)$ in the framework of QCD sum rules approach with direct instantons
10 pages, fifth version, add discussions
Commun.Theor.Phys.45:320-324,2006
10.1088/0253-6102/45/2/025
null
hep-ph
null
In this article, we study the pentaquark state $ \Theta^+(1540)$ with a (scalar)diquark-(pseudoscalar)diquark-antiquark type interpolating current in the framework of the QCD sum rules approach by including the contributions from the direct instantons. The numerical results indicate that the contributions from the direct instantons are very small and can be safely neglected.
[ { "created": "Tue, 4 Jan 2005 12:05:12 GMT", "version": "v1" }, { "created": "Fri, 7 Jan 2005 03:23:56 GMT", "version": "v2" }, { "created": "Sat, 16 Apr 2005 12:06:23 GMT", "version": "v3" }, { "created": "Thu, 14 Jul 2005 08:15:15 GMT", "version": "v4" }, { "created": "Tue, 19 Jul 2005 13:08:59 GMT", "version": "v5" } ]
2008-11-26
[ [ "Wang", "Zhi-Gang", "", "NCEPU" ], [ "Yang", "Wei-Min", "", "USTC" ], [ "Wan", "Shao-Long", "", "USTC" ] ]
In this article, we study the pentaquark state $ \Theta^+(1540)$ with a (scalar)diquark-(pseudoscalar)diquark-antiquark type interpolating current in the framework of the QCD sum rules approach by including the contributions from the direct instantons. The numerical results indicate that the contributions from the direct instantons are very small and can be safely neglected.
1111.1427
Joachim Brod
Joachim Brod
The charm-quark contribution to epsilon_K and Delta M_K
4 pages, 1 figure. Contribution to the proceedings of the 2011 Europhysics Conference on High Energy Physics (EPS-HEP 2011), Grenoble, July 21-27, 2011
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Neutral Kaon mixing plays an important role in the phenomenology of the standard model and its extensions because of its sensitivity to high-energy scales. In particular epsilon_K, parameterising indirect CP violation in the neutral Kaon system, serves as an important constraint on models of new physics and is well suited for the indirect search for heavy new particles. In order to exploit this potential, a precise prediction of the standard-model background is crucial. I give a short summary of the standard-model prediction of epsilon_K, and present our recent NNLO QCD calculation of the charm-quark contribution eta_cc to the |Delta S| = 2 effective Hamiltonian. We find a large 36% shift with respect to the NLO value that leads to eta_cc = 1.87(76), shifting the standard-model prediction to |epsilon_K| = 1.81(28) x 10^-3.
[ { "created": "Sun, 6 Nov 2011 15:49:51 GMT", "version": "v1" } ]
2011-11-08
[ [ "Brod", "Joachim", "" ] ]
Neutral Kaon mixing plays an important role in the phenomenology of the standard model and its extensions because of its sensitivity to high-energy scales. In particular epsilon_K, parameterising indirect CP violation in the neutral Kaon system, serves as an important constraint on models of new physics and is well suited for the indirect search for heavy new particles. In order to exploit this potential, a precise prediction of the standard-model background is crucial. I give a short summary of the standard-model prediction of epsilon_K, and present our recent NNLO QCD calculation of the charm-quark contribution eta_cc to the |Delta S| = 2 effective Hamiltonian. We find a large 36% shift with respect to the NLO value that leads to eta_cc = 1.87(76), shifting the standard-model prediction to |epsilon_K| = 1.81(28) x 10^-3.
1111.4765
Ryo Sahara
Ryo Sahara, Tsuneo Uematsu, Yoshio Kitadono
Photon Structure Function in Supersymmetric QCD Revisited
6 pages, LaTeX 3 eps figures, elsarticle.cls, typos corrected, comments added
Phys. Lett. B 707 (2012) 517--522
10.1016/j.physletb.2012.01.002
KUNS-2373; MISC-2011-18
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the virtual photon structure function in the supersymmetric QCD (SQCD), where we have squarks and gluinos in addition to the quarks and gluons. Taking into account the heavy particle mass effects to the leading order in QCD and SQCD we evaluate the photon structure function and numerically study its behavior for the QCD and SQCD cases.
[ { "created": "Mon, 21 Nov 2011 06:00:09 GMT", "version": "v1" }, { "created": "Fri, 20 Jan 2012 07:10:08 GMT", "version": "v2" } ]
2012-01-23
[ [ "Sahara", "Ryo", "" ], [ "Uematsu", "Tsuneo", "" ], [ "Kitadono", "Yoshio", "" ] ]
We investigate the virtual photon structure function in the supersymmetric QCD (SQCD), where we have squarks and gluinos in addition to the quarks and gluons. Taking into account the heavy particle mass effects to the leading order in QCD and SQCD we evaluate the photon structure function and numerically study its behavior for the QCD and SQCD cases.
1907.10921
Zhi-Gang Wang
Zhi-Gang Wang
Analysis of the axialvector $B_c$-like tetraquark states with the QCD sum rules
11 pages, 5 figures
EPL 128 (2019) 11001
10.1209/0295-5075/128/11001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article, we construct the diquark-antidiquark type current operators to study the axialvector $B_c$-like tetraquark states with the QCD sum rules. In calculations, we take the energy scale formula as a powerful constraint to choose the ideal energy scales of the QCD spectral densities and add detailed discussions to illustrate why we take the energy scale formula to improve the QCD sum rules for the doubly heavy tetraquark states. The predicted masses $M_{Z_{\bar{b}c}(1^{+-})}=7.30\pm0.08\,\rm{GeV}$ and $M_{Z_{\bar{b}c}(1^{++})}=7.31\pm0.08\,\rm{GeV}$ lie between the conventional $2\rm{P}$ and $3\rm{P}$ $B_c$ states with $J^P=1^+$ from the potential quark models, which is a typical feature of the diquark-antidiquark type $B_c$-like tetraquark states.
[ { "created": "Thu, 25 Jul 2019 09:29:12 GMT", "version": "v1" }, { "created": "Sun, 22 Sep 2019 01:29:01 GMT", "version": "v2" } ]
2019-11-21
[ [ "Wang", "Zhi-Gang", "" ] ]
In this article, we construct the diquark-antidiquark type current operators to study the axialvector $B_c$-like tetraquark states with the QCD sum rules. In calculations, we take the energy scale formula as a powerful constraint to choose the ideal energy scales of the QCD spectral densities and add detailed discussions to illustrate why we take the energy scale formula to improve the QCD sum rules for the doubly heavy tetraquark states. The predicted masses $M_{Z_{\bar{b}c}(1^{+-})}=7.30\pm0.08\,\rm{GeV}$ and $M_{Z_{\bar{b}c}(1^{++})}=7.31\pm0.08\,\rm{GeV}$ lie between the conventional $2\rm{P}$ and $3\rm{P}$ $B_c$ states with $J^P=1^+$ from the potential quark models, which is a typical feature of the diquark-antidiquark type $B_c$-like tetraquark states.
hep-ph/9504211
null
A. Djouadi
SEARCHING FOR NEW MATTER PARTICLES AT FUTURE COLLIDERS
8 pages, latex, 5 figures (not included), the full *.ps file including the figures can be obtained via anonymous ftp at ftp://lpsvsh.lps.umontreal.ca/hep_th/tahoe.ps
null
null
GPP-UdeM-TH-95-18
hep-ph
null
We discuss the production of new matter particles that are predicted by many extensions of the Standard Model, at future high--energy pp, eP and $e^+e^-$ linear colliders. We focus on the case of exotic, excited and di--fermions. Talk given at "Beyond the Standard Model IV", Lake Tahoe, Ca., December 1994.
[ { "created": "Mon, 3 Apr 1995 21:18:33 GMT", "version": "v1" } ]
2007-05-23
[ [ "Djouadi", "A.", "" ] ]
We discuss the production of new matter particles that are predicted by many extensions of the Standard Model, at future high--energy pp, eP and $e^+e^-$ linear colliders. We focus on the case of exotic, excited and di--fermions. Talk given at "Beyond the Standard Model IV", Lake Tahoe, Ca., December 1994.
1703.10160
Ruben Jaarsma
Robert Fleischer, Ruben Jaarsma, Gilberto Tetlalmatzi-Xolocotzi
In Pursuit of New Physics with $B^0_{s,d}\to\ell^+\ell^-$
24 pages, 7 figures, more general discussion, application of MSSM MFV model corrected, main conclusions unchanged
null
10.1007/JHEP05(2017)156
Nikhef-2017-023
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Leptonic rare decays of $B^0_{s,d}$ mesons offer a powerful tool to search for physics beyond the Standard Model. The $B^0_{s}\to\mu^+\mu^-$ decay has been observed at the Large Hadron Collider and the first measurement of the effective lifetime of this channel was presented, in accordance with the Standard Model. On the other hand, $B^0_{s}\to\tau^+\tau^-$ and $B^0_{s}\to e^+e^-$ have received considerably less attention: while LHCb has recently reported a first upper limit of $6.8\times10^{-3}$ (95% C.L.) for the $B^0_s\to\tau^+\tau^-$ branching ratio, the upper bound $2.8\times 10^{-7}$ (90% C.L.) for the branching ratio of $B^0_s\to e^+e^-$ was reported by CDF back in 2009. We discuss the current status of the interpretation of the measurement of $B^0_{s}\to\mu^+\mu^-$, and explore the space for New-Physics effects in the other $B^0_{s,d}\to\ell^+\ell^-$ decays in a scenario assuming flavour-universal Wilson coefficients of the relevant four-fermion operators. While the New-Physics effects are then strongly suppressed by the ratio $m_\mu/m_\tau$ of the lepton masses in $B^0_s\to\tau^+\tau^-$, they are hugely enhanced by $m_\mu/m_e$ in $B^0_s\to e^+e^-$ and may result in a $B^0_s\to e^+e^-$ branching ratio as large as about 5 times the one of $B^0_{s}\to\mu^+\mu^-$, which is about a factor of 20 below the CDF bound; a similar feature arises in $B^0_{d}\to e^+e^-$. Consequently, it would be most interesting to search for the $B^0_{s,d}\to e^+e^-$ channels at the LHC and Belle II, which may result in an unambiguous signal for physics beyond the Standard Model.
[ { "created": "Wed, 29 Mar 2017 17:58:04 GMT", "version": "v1" }, { "created": "Tue, 4 Apr 2017 17:32:52 GMT", "version": "v2" } ]
2017-09-13
[ [ "Fleischer", "Robert", "" ], [ "Jaarsma", "Ruben", "" ], [ "Tetlalmatzi-Xolocotzi", "Gilberto", "" ] ]
Leptonic rare decays of $B^0_{s,d}$ mesons offer a powerful tool to search for physics beyond the Standard Model. The $B^0_{s}\to\mu^+\mu^-$ decay has been observed at the Large Hadron Collider and the first measurement of the effective lifetime of this channel was presented, in accordance with the Standard Model. On the other hand, $B^0_{s}\to\tau^+\tau^-$ and $B^0_{s}\to e^+e^-$ have received considerably less attention: while LHCb has recently reported a first upper limit of $6.8\times10^{-3}$ (95% C.L.) for the $B^0_s\to\tau^+\tau^-$ branching ratio, the upper bound $2.8\times 10^{-7}$ (90% C.L.) for the branching ratio of $B^0_s\to e^+e^-$ was reported by CDF back in 2009. We discuss the current status of the interpretation of the measurement of $B^0_{s}\to\mu^+\mu^-$, and explore the space for New-Physics effects in the other $B^0_{s,d}\to\ell^+\ell^-$ decays in a scenario assuming flavour-universal Wilson coefficients of the relevant four-fermion operators. While the New-Physics effects are then strongly suppressed by the ratio $m_\mu/m_\tau$ of the lepton masses in $B^0_s\to\tau^+\tau^-$, they are hugely enhanced by $m_\mu/m_e$ in $B^0_s\to e^+e^-$ and may result in a $B^0_s\to e^+e^-$ branching ratio as large as about 5 times the one of $B^0_{s}\to\mu^+\mu^-$, which is about a factor of 20 below the CDF bound; a similar feature arises in $B^0_{d}\to e^+e^-$. Consequently, it would be most interesting to search for the $B^0_{s,d}\to e^+e^-$ channels at the LHC and Belle II, which may result in an unambiguous signal for physics beyond the Standard Model.
hep-ph/0409252
Don Colladay
Don Colladay and Patrick McDonald
Nonrelativisitic Ideal Gasses and Lorentz Violations
6 pages, proceedings for CPT and Lorentz Symmetry, Bloomington, IN, 2004
null
10.1142/9789812702173_0032
null
hep-ph
null
We develop statistical mechanics for a nonrelativisitic ideal gas in the presence of Lorentz violating background fields. The analysis is performed using the Standard-Model Extension (SME). We derive the corresponding laws of thermodynamics and find that, to lowest order in Lorentz violation, the scalar thermodynamic variables are corrected by a rotationally invariant combination of the Lorentz terms which can be interpreted in terms of a (frame dependent) effective mass. We find that spin couplings can induce a temperature independent polarization in the gas that is not present in the conventional case.
[ { "created": "Tue, 21 Sep 2004 19:07:43 GMT", "version": "v1" } ]
2016-11-03
[ [ "Colladay", "Don", "" ], [ "McDonald", "Patrick", "" ] ]
We develop statistical mechanics for a nonrelativisitic ideal gas in the presence of Lorentz violating background fields. The analysis is performed using the Standard-Model Extension (SME). We derive the corresponding laws of thermodynamics and find that, to lowest order in Lorentz violation, the scalar thermodynamic variables are corrected by a rotationally invariant combination of the Lorentz terms which can be interpreted in terms of a (frame dependent) effective mass. We find that spin couplings can induce a temperature independent polarization in the gas that is not present in the conventional case.
1703.02061
Alexandre Alves
Alexandre Alves, Alex G. Dias and Roberto da Silva
Maximum Entropy Inferences on the Axion Mass in Models with Axion-Neutrino Interaction
13 pages, 5 figures, typos corrected, figures updated
null
10.1007/s13538-017-0515-y
null
hep-ph cond-mat.stat-mech hep-th physics.data-an
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we use the Maximum Entropy Principle (MEP) to infer the mass of an axion which interacts to photons and neutrinos in an effective low energy theory. The Shannon entropy function to be maximized is suitably defined in terms of the axion branching ratios. We show that MEP strongly constrains the axion mass taking into account the current experimental bounds on the neutrinos masses. Assuming that the axion is massive enough to decay into all the three neutrinos and that MEP fixes all the free parameters of the model, the inferred axion mass is in the interval $0.1\ $eV$\ <m_{A}<0.2$ eV, which can be tested by forthcoming experiments such as IAXO. However, even in the case where MEP fixes just the axion mass and no other parameter, we found that $0.1$ eV $< m_A < 6.3$ eV in the DFSZ model with right-handed neutrinos. Moreover, a light axion, allowed to decay to photons and the lightest neutrino only, is determined by MEP as a viable dark matter candidate.
[ { "created": "Mon, 6 Mar 2017 19:02:09 GMT", "version": "v1" }, { "created": "Thu, 9 Mar 2017 16:15:06 GMT", "version": "v2" } ]
2017-08-02
[ [ "Alves", "Alexandre", "" ], [ "Dias", "Alex G.", "" ], [ "da Silva", "Roberto", "" ] ]
In this work we use the Maximum Entropy Principle (MEP) to infer the mass of an axion which interacts to photons and neutrinos in an effective low energy theory. The Shannon entropy function to be maximized is suitably defined in terms of the axion branching ratios. We show that MEP strongly constrains the axion mass taking into account the current experimental bounds on the neutrinos masses. Assuming that the axion is massive enough to decay into all the three neutrinos and that MEP fixes all the free parameters of the model, the inferred axion mass is in the interval $0.1\ $eV$\ <m_{A}<0.2$ eV, which can be tested by forthcoming experiments such as IAXO. However, even in the case where MEP fixes just the axion mass and no other parameter, we found that $0.1$ eV $< m_A < 6.3$ eV in the DFSZ model with right-handed neutrinos. Moreover, a light axion, allowed to decay to photons and the lightest neutrino only, is determined by MEP as a viable dark matter candidate.
0808.1040
Sergey Bondarenko
Bondarenko Sergey
Gluon density and $F_{2}$ functions from BK equation with local impact parameter dependence in DIS on nuclei
30 pages, 19 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The DIS process on nuclei is considered in the framework of LO BK equation with local impact parameter dependence. Solving BK equation parameters for initial conditions of GBW type found in \cite{Serg1} were used. Integrated gluon density function and $F_2$ nucleus structure function for different nuclei are calculated. Obtained results are compared with the different parameterizations of integrated gluon density function from \cite{Flor,Eskola1,Eskola2,Tywon}. The anomalous dimensions and saturation scales for different nuclei are calculated at different energies. Fitting obtained results, expressions for the form of saturation scale are obtained for the proton and different nuclei as functions of impact parameter and energy.
[ { "created": "Thu, 7 Aug 2008 14:40:29 GMT", "version": "v1" }, { "created": "Mon, 6 Oct 2008 12:41:21 GMT", "version": "v2" }, { "created": "Tue, 27 Apr 2010 07:18:18 GMT", "version": "v3" } ]
2010-04-28
[ [ "Sergey", "Bondarenko", "" ] ]
The DIS process on nuclei is considered in the framework of LO BK equation with local impact parameter dependence. Solving BK equation parameters for initial conditions of GBW type found in \cite{Serg1} were used. Integrated gluon density function and $F_2$ nucleus structure function for different nuclei are calculated. Obtained results are compared with the different parameterizations of integrated gluon density function from \cite{Flor,Eskola1,Eskola2,Tywon}. The anomalous dimensions and saturation scales for different nuclei are calculated at different energies. Fitting obtained results, expressions for the form of saturation scale are obtained for the proton and different nuclei as functions of impact parameter and energy.
hep-ph/0004162
Ville Sipilainen
J. T. Peltoniemi and V. Sipilainen
Neutrino propagation in matter using the wave packet approach
21 pages, LATEX, no figures
JHEP 0006:011,2000
10.1088/1126-6708/2000/06/011
UO-130/2000
hep-ph
null
We study the oscillations and conversions of relativistic neutrinos propagating in matter of variable density using the wave packet formalism. We show how the oscillation and coherence lengths are modified in comparison with the case of oscillations in vacuum. Secondly, we demonstrate how the equation of motion for two neutrino flavors can be formally solved for almost arbitrary density profile. We calculate finally how the use of wave packets alters the nonadiabatic level crossing probabilities. For the most common physical environments the corrections due to the width of the wave packet do not lead to observable effects.
[ { "created": "Mon, 17 Apr 2000 12:03:26 GMT", "version": "v1" } ]
2011-07-19
[ [ "Peltoniemi", "J. T.", "" ], [ "Sipilainen", "V.", "" ] ]
We study the oscillations and conversions of relativistic neutrinos propagating in matter of variable density using the wave packet formalism. We show how the oscillation and coherence lengths are modified in comparison with the case of oscillations in vacuum. Secondly, we demonstrate how the equation of motion for two neutrino flavors can be formally solved for almost arbitrary density profile. We calculate finally how the use of wave packets alters the nonadiabatic level crossing probabilities. For the most common physical environments the corrections due to the width of the wave packet do not lead to observable effects.
hep-ph/0312331
Adrian Signer
M. Beneke, A.P. Chapovsky, A. Signer and G. Zanderighi
Effective theory approach to unstable particle production
4 pages, 1 figure
Phys.Rev.Lett. 93 (2004) 011602
10.1103/PhysRevLett.93.011602
PITHA 03/13, IPPP/03/82, FERMILAB-Pub-03/407-T
hep-ph
null
Using the hierarchy of scales between the mass, $M$, and the width, $\Gamma$, of a heavy, unstable particle we construct an effective theory that allows calculations for resonant processes to be systematically expanded in powers of the coupling $\alpha$ and $\Gamma/M$. We illustrate the method by computing the next-to-leading order line shape of a scalar resonance in an abelian gauge-Yukawa model.
[ { "created": "Tue, 23 Dec 2003 11:47:50 GMT", "version": "v1" } ]
2009-11-10
[ [ "Beneke", "M.", "" ], [ "Chapovsky", "A. P.", "" ], [ "Signer", "A.", "" ], [ "Zanderighi", "G.", "" ] ]
Using the hierarchy of scales between the mass, $M$, and the width, $\Gamma$, of a heavy, unstable particle we construct an effective theory that allows calculations for resonant processes to be systematically expanded in powers of the coupling $\alpha$ and $\Gamma/M$. We illustrate the method by computing the next-to-leading order line shape of a scalar resonance in an abelian gauge-Yukawa model.
hep-ph/0005131
Kirill Melnikov
Kirill Melnikov and Timo van Ritbergen
The three loop on-shell renormalization of QCD and QED
24 pages, 2 figures, revtex
Nucl.Phys. B591 (2000) 515-546
10.1016/S0550-3213(00)00526-5
SLAC-PUB-8450, TTP00-08
hep-ph
null
We describe a calculation of the on-shell renormalization factors in QCD and QED at the three loop level. Explicit results for the fermion mass renormalization factor Zm and the on-shell fermion wave function renormalization constant Z2 are given. We find that at O(alpha_s^3) the wave function renormalization constant Z2 in QCD becomes gauge dependent also in the on-shell scheme, thereby disproving the ``gauge-independence'' conjecture based on an earlier two-loop result. As a byproduct, we derive an O(alpha_s^3) contribution to the anomalous dimension of the heavy quark field in HQET.
[ { "created": "Sun, 14 May 2000 01:13:46 GMT", "version": "v1" } ]
2009-10-31
[ [ "Melnikov", "Kirill", "" ], [ "van Ritbergen", "Timo", "" ] ]
We describe a calculation of the on-shell renormalization factors in QCD and QED at the three loop level. Explicit results for the fermion mass renormalization factor Zm and the on-shell fermion wave function renormalization constant Z2 are given. We find that at O(alpha_s^3) the wave function renormalization constant Z2 in QCD becomes gauge dependent also in the on-shell scheme, thereby disproving the ``gauge-independence'' conjecture based on an earlier two-loop result. As a byproduct, we derive an O(alpha_s^3) contribution to the anomalous dimension of the heavy quark field in HQET.
hep-ph/9911291
Yu. A. Simonov
A.B.Kaidalov and Yu.A.Simonov (ITEP, Moscow)
Glueball spectrum and the Pomeron in the Wilson loop approach
LaTeX2e, 49 pages, 2 figures
Phys.Atom.Nucl.63:1428-1447,2000; Yad.Fiz.63:1428-1447,2000
10.1134/1.1307465
null
hep-ph
null
Using a nonperturbative method based on asymptotic behaviour of Wilson loops we calculate masses of glueballs and corresponding Regge-trajectories. The only input is string tension fixed by meson Regge slope, while perturbative contributions to spin splittings are defined by standard alpha_s values. The masses of lowest glueball states are in a perfect agreement with lattice results. The leading glueball trajectory which is associated with Pomeron is discussed in details and its mixing with f and f' trajectories is taken into account.
[ { "created": "Tue, 9 Nov 1999 22:27:27 GMT", "version": "v1" } ]
2014-11-17
[ [ "Kaidalov", "A. B.", "", "ITEP, Moscow" ], [ "Simonov", "Yu. A.", "", "ITEP, Moscow" ] ]
Using a nonperturbative method based on asymptotic behaviour of Wilson loops we calculate masses of glueballs and corresponding Regge-trajectories. The only input is string tension fixed by meson Regge slope, while perturbative contributions to spin splittings are defined by standard alpha_s values. The masses of lowest glueball states are in a perfect agreement with lattice results. The leading glueball trajectory which is associated with Pomeron is discussed in details and its mixing with f and f' trajectories is taken into account.
hep-ph/0109233
Levai Peter
Y. Zhang, G. Fai, G. Papp, G.G. Barnafoldi, P. Levai
High-p_T pion and kaon production in relativistic nuclear collisions
26 pages in Latex, 19 EPS figures
Phys.Rev.C65:034903,2002
10.1103/PhysRevC.65.034903
null
hep-ph nucl-ex nucl-th
null
High-p_T pion and kaon production is studied in relativistic proton-proton, proton-nucleus, and nucleus-nucleus collisions in a wide energy range. Cross sections are calculated based on perturbative QCD, augmented by a phenomenological transverse momentum distribution of partons (``intrinsic k_T''). An energy dependent width of the transverse momentum distribution is extracted from pion and charged hadron production data in proton-proton/proton-antiproton collisions. Effects of multiscattering and shadowing in the strongly interacting medium are taken into account. Enhancement of the transverse momentum width is introduced and parameterized to explain the Cronin effect. In collisions between heavy nuclei, the model over-predicts central pion production cross sections (more significantly at higher energies), hinting at the presence of jet quenching. Predictions are made for proton-nucleus and nucleus-nucleus collisions at RHIC energies.
[ { "created": "Tue, 25 Sep 2001 17:41:56 GMT", "version": "v1" } ]
2008-11-26
[ [ "Zhang", "Y.", "" ], [ "Fai", "G.", "" ], [ "Papp", "G.", "" ], [ "Barnafoldi", "G. G.", "" ], [ "Levai", "P.", "" ] ]
High-p_T pion and kaon production is studied in relativistic proton-proton, proton-nucleus, and nucleus-nucleus collisions in a wide energy range. Cross sections are calculated based on perturbative QCD, augmented by a phenomenological transverse momentum distribution of partons (``intrinsic k_T''). An energy dependent width of the transverse momentum distribution is extracted from pion and charged hadron production data in proton-proton/proton-antiproton collisions. Effects of multiscattering and shadowing in the strongly interacting medium are taken into account. Enhancement of the transverse momentum width is introduced and parameterized to explain the Cronin effect. In collisions between heavy nuclei, the model over-predicts central pion production cross sections (more significantly at higher energies), hinting at the presence of jet quenching. Predictions are made for proton-nucleus and nucleus-nucleus collisions at RHIC energies.
hep-ph/0501190
Priscilla Cushman
Priscilla Cushman
Muon g-2 Constraints to SUSY Dark Matter over the Next Decade
(typos corrected) 14 pages, LaTex, etc), 8 figures (color), Proceedings of Dark2004 (5th Int'l Heidelberg Conf. on Dark Matter), TAMU, Oct 3-9, 2004
null
null
null
hep-ph
null
The anomalous magnetic moment of the muon has been measured to 0.5 ppm in a series of precision experiments at the Brookhaven Alternating Gradient Synchrotron. The individual results for each sign: a(mu+)= 11 659 204(7)(5) E-10 and a(mu-) = 11 659 214(8)(3) E-10 are consistent with each other, so that we can write the average anomaly as a(mu)(exp) = 11 659 208(6) E-10 (0.5 ppm). A discrepancy between the measured value and the Standard Model (Delta a(mu)) is a signal for new physics. Assuming that such a discrepancy is due to contributions from supersymmetric particles provides a framework which can be used to constrain the mass of the dark matter particles, assumed to be the lightest neutral supersymmetric particles. The deviation from the standard model has varied between 1.5 sigma and 3 sigma significance, dominated by uncertainties in the hadronic contribution to the standard model calculation. Currently the standard model prediction is calculated to 0.6 ppm precision and Delta a(mu) = 23.5 (9.0) E-10, representing a 2.6 sigma deviation. We expect that the error on a(mu)(SM) will be reduced by a factor of two within the next decade. To fully utilize this improvement, a new g-2 run is proposed for the near future. If the mean Delta a(mu) remains the same, this would result in close to a 6 sigma discrepancy. In this case, we would expect to see SUSY particles at the LHC and use the g-2 results to measure tan beta. If, instead, the Standard Model is confirmed to this precision, gauginos must have masses higher than ~ 500 GeV/c2 and simple SUSY dark matter models will be severely constrained.
[ { "created": "Thu, 20 Jan 2005 16:19:41 GMT", "version": "v1" }, { "created": "Tue, 1 Feb 2005 17:52:10 GMT", "version": "v2" } ]
2007-05-23
[ [ "Cushman", "Priscilla", "" ] ]
The anomalous magnetic moment of the muon has been measured to 0.5 ppm in a series of precision experiments at the Brookhaven Alternating Gradient Synchrotron. The individual results for each sign: a(mu+)= 11 659 204(7)(5) E-10 and a(mu-) = 11 659 214(8)(3) E-10 are consistent with each other, so that we can write the average anomaly as a(mu)(exp) = 11 659 208(6) E-10 (0.5 ppm). A discrepancy between the measured value and the Standard Model (Delta a(mu)) is a signal for new physics. Assuming that such a discrepancy is due to contributions from supersymmetric particles provides a framework which can be used to constrain the mass of the dark matter particles, assumed to be the lightest neutral supersymmetric particles. The deviation from the standard model has varied between 1.5 sigma and 3 sigma significance, dominated by uncertainties in the hadronic contribution to the standard model calculation. Currently the standard model prediction is calculated to 0.6 ppm precision and Delta a(mu) = 23.5 (9.0) E-10, representing a 2.6 sigma deviation. We expect that the error on a(mu)(SM) will be reduced by a factor of two within the next decade. To fully utilize this improvement, a new g-2 run is proposed for the near future. If the mean Delta a(mu) remains the same, this would result in close to a 6 sigma discrepancy. In this case, we would expect to see SUSY particles at the LHC and use the g-2 results to measure tan beta. If, instead, the Standard Model is confirmed to this precision, gauginos must have masses higher than ~ 500 GeV/c2 and simple SUSY dark matter models will be severely constrained.
1811.02231
Abhishek Iyer M
Abhishek M. Iyer and K. Sridhar
Unearthing the electroweak structure of warped 5D models
5 Pages, 2 Figures
Phys. Rev. D 100, 015022 (2019)
10.1103/PhysRevD.100.015022
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Heavy charged bosons, with masses in the range of a few TeV, are a characteristic of warped extra-dimensional models with bulk gauge fields. Rendering the latter consistent with electroweak precision tests typically requires either a deformation of the metric or extension of the gauge symmetry. We make here the first attempt at finding empirical discriminants which would tell these models apart. Demonstrating the power of simple kinematic observables involving same-sign leptons, we construct simple yet powerful statistical discriminants.
[ { "created": "Tue, 6 Nov 2018 08:58:15 GMT", "version": "v1" } ]
2019-07-24
[ [ "Iyer", "Abhishek M.", "" ], [ "Sridhar", "K.", "" ] ]
Heavy charged bosons, with masses in the range of a few TeV, are a characteristic of warped extra-dimensional models with bulk gauge fields. Rendering the latter consistent with electroweak precision tests typically requires either a deformation of the metric or extension of the gauge symmetry. We make here the first attempt at finding empirical discriminants which would tell these models apart. Demonstrating the power of simple kinematic observables involving same-sign leptons, we construct simple yet powerful statistical discriminants.
1011.2422
Wolfgang Ochs
Wolfgang Ochs
Limiting soft particle production and QCD
20 pages, 5 figures, presented at the 50th Cracow School of Theoretical Physics, 9-19 June 2010, Zakopane, Poland
Acta Phys.Polon.B41:2839-2858,2010
null
MPP-2010-146
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present some basic elements of the treatment of particle multiplicities in jets from high energy collisions within perturbative QCD. Then we discuss the universal features of the inclusive particle spectrum for the limiting case of momentum p\to 0 (or p_T\to 0) as expected from soft QCD gluon bremsstrahlung. The energy independence of the invariant particle density in this limit I_0=E dN/d^3p|_{p\to 0} is predicted as well as the dependence of this quantity on the the colour factors characteristic of the underlying partonic processes. These properties are first recalled from e+e- collisions and then extended to pp and nuclear collisions according to Ref. 1. Present data support these predictions. It will be interesting to see whether new incoherent contributions show up in the new energy regime of LHC.
[ { "created": "Wed, 10 Nov 2010 16:36:37 GMT", "version": "v1" } ]
2011-05-12
[ [ "Ochs", "Wolfgang", "" ] ]
We present some basic elements of the treatment of particle multiplicities in jets from high energy collisions within perturbative QCD. Then we discuss the universal features of the inclusive particle spectrum for the limiting case of momentum p\to 0 (or p_T\to 0) as expected from soft QCD gluon bremsstrahlung. The energy independence of the invariant particle density in this limit I_0=E dN/d^3p|_{p\to 0} is predicted as well as the dependence of this quantity on the the colour factors characteristic of the underlying partonic processes. These properties are first recalled from e+e- collisions and then extended to pp and nuclear collisions according to Ref. 1. Present data support these predictions. It will be interesting to see whether new incoherent contributions show up in the new energy regime of LHC.
hep-ph/0204018
J. Raufeisen
J. Raufeisen
QCD coherence effects in low-x DIS and Drell-Yan with nuclear targets
6 pages, 6 figures, invited talk to be held at SCI 2002 conf., Orlando, Florida, July 14 - 18, 2002
null
null
null
hep-ph
null
We investigate QCD coherence effects in deep inelastic scattering (DIS) off nuclei and in Drell-Yan (DY) dilepton production in proton-nucleus collisions within the light-cone color-dipole approach. The physical mechanisms underlying the nuclear effects become very transparent in this approach and are explained in some detail. We present numerical calculations of nuclear shadowing in DIS and DY and compare to data. Nuclear effects in the DY transverse momentum distribution are calculated as well. The dipole approach is the only known way to calculate the Cronin effect without introducing additional parameters for nuclear targets.
[ { "created": "Tue, 2 Apr 2002 03:25:22 GMT", "version": "v1" } ]
2007-05-23
[ [ "Raufeisen", "J.", "" ] ]
We investigate QCD coherence effects in deep inelastic scattering (DIS) off nuclei and in Drell-Yan (DY) dilepton production in proton-nucleus collisions within the light-cone color-dipole approach. The physical mechanisms underlying the nuclear effects become very transparent in this approach and are explained in some detail. We present numerical calculations of nuclear shadowing in DIS and DY and compare to data. Nuclear effects in the DY transverse momentum distribution are calculated as well. The dipole approach is the only known way to calculate the Cronin effect without introducing additional parameters for nuclear targets.
1311.1908
Stefan Kofler
Alexander T. Goritschnig, Stefan Kofler and Wolfgang Schweiger
First results of proton antiproton annihilation into a pion pair at large scattering angles within the handbag approach
FAIR NExt generation ScientistS 2013 (FAIRNESS 2013) CNUM: C13-09-16.2
null
10.1088/1742-6596/503/1/012032
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose to describe the process $ p ~ \bar{p} \rightarrow \pi^+ ~ \pi^-$ in a perturbative, QCD motivated framework in which a hard $ud \, \bar{u} \bar{d} \rightarrow d \, \bar{d} $ annihilation factorizes from soft transition distribution amplitudes. We advocate that the scale allowing for this factorization is the large transverse momentum transfer. In our simplified model, in which the proton is considered as a (scalar)diqark-quark system, a transition distribution amplitude describes the non-perturbative transition of the proton to the meson by emission of a scalar, isoscalar $ ud $-diquark and absorption of an antiquark (analogously for $ \bar{p} \rightarrow \pi^- $). We model the transition distribution amplitudes as an overlap of light-cone wave functions and present first results for the differential cross section. This process will be measured by the $ \bar{\mbox{P}}$ANDA experiment at GSI-FAIR.
[ { "created": "Fri, 8 Nov 2013 09:26:17 GMT", "version": "v1" } ]
2015-06-17
[ [ "Goritschnig", "Alexander T.", "" ], [ "Kofler", "Stefan", "" ], [ "Schweiger", "Wolfgang", "" ] ]
We propose to describe the process $ p ~ \bar{p} \rightarrow \pi^+ ~ \pi^-$ in a perturbative, QCD motivated framework in which a hard $ud \, \bar{u} \bar{d} \rightarrow d \, \bar{d} $ annihilation factorizes from soft transition distribution amplitudes. We advocate that the scale allowing for this factorization is the large transverse momentum transfer. In our simplified model, in which the proton is considered as a (scalar)diqark-quark system, a transition distribution amplitude describes the non-perturbative transition of the proton to the meson by emission of a scalar, isoscalar $ ud $-diquark and absorption of an antiquark (analogously for $ \bar{p} \rightarrow \pi^- $). We model the transition distribution amplitudes as an overlap of light-cone wave functions and present first results for the differential cross section. This process will be measured by the $ \bar{\mbox{P}}$ANDA experiment at GSI-FAIR.
1712.09322
David Blaschke
D. Blaschke, A. Dubinin, D. Ebert, A. V. Friesen
Effects of composite pions on the chiral condensate within the PNJL model at finite temperature
14 pages, 4 figures, version published in Phys. Part. Nucl. Lett
Phys. Part. Nucl. Lett. 15 (2018) no. 3, 230-235
10.1134/S1547477118030056
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the effect of composite pions on the behaviour of the chiral condensate at finite temperature within the Polyakov-loop improved NJL model. To this end we treat quark-antiquark correlations in the pion channel (bound states and scattering continuum) within a Beth-Uhlenbeck approach that uses medium-dependent phase shifts. A striking medium effect is the Mott transition which occurs when the binding energy vanishes and the discrete pion bound state merges the continuum. This transition is triggered by the lowering of the continuum edge due to the chiral restoration transition. This in turn also entails a modification of the Polyakov-loop so that the SU(3) center symmetry gets broken at finite temperature and dynamical quarks (and gluons) appear in the system, taking over the role of the dominant degrees of freedom from the pions. At low temperatures our model reproduces the chiral perturbation theory result for the chiral condensate while at high temperatures the PNJL model result is recovered. The new aspect of the current work is a consistent treatment of the chiral restoration transition region within the Beth-Uhlenbeck approach on the basis of mesonic phase shifts for the treatment of the correlations.
[ { "created": "Tue, 26 Dec 2017 18:35:44 GMT", "version": "v1" }, { "created": "Thu, 28 Dec 2017 12:11:42 GMT", "version": "v2" }, { "created": "Mon, 15 Jan 2018 17:49:22 GMT", "version": "v3" }, { "created": "Thu, 3 May 2018 09:05:57 GMT", "version": "v4" } ]
2018-05-04
[ [ "Blaschke", "D.", "" ], [ "Dubinin", "A.", "" ], [ "Ebert", "D.", "" ], [ "Friesen", "A. V.", "" ] ]
We investigate the effect of composite pions on the behaviour of the chiral condensate at finite temperature within the Polyakov-loop improved NJL model. To this end we treat quark-antiquark correlations in the pion channel (bound states and scattering continuum) within a Beth-Uhlenbeck approach that uses medium-dependent phase shifts. A striking medium effect is the Mott transition which occurs when the binding energy vanishes and the discrete pion bound state merges the continuum. This transition is triggered by the lowering of the continuum edge due to the chiral restoration transition. This in turn also entails a modification of the Polyakov-loop so that the SU(3) center symmetry gets broken at finite temperature and dynamical quarks (and gluons) appear in the system, taking over the role of the dominant degrees of freedom from the pions. At low temperatures our model reproduces the chiral perturbation theory result for the chiral condensate while at high temperatures the PNJL model result is recovered. The new aspect of the current work is a consistent treatment of the chiral restoration transition region within the Beth-Uhlenbeck approach on the basis of mesonic phase shifts for the treatment of the correlations.
2005.07022
Wren Yamada
Wren Yamada, and Osamu Morimatsu
A New Method to Extract Information of Near-Threshold Resonances: Uniformized Pole-Sum Representation of Green's Function and T-matrix
null
Phys. Rev. C 102, 055201 (2020)
10.1103/PhysRevC.102.055201
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a new, simple model-independent method to extract information of near-threshold resonances, such as complex energies and residues. The method is based on the observation that the Green's function and the T-matrix can be represented as the sum of all poles, both bound and resonant poles, in the complex plane of a variable in which the Green's function and the T-matrix are single-valued functions. The symmetries of poles, which arise from the unitarity of the S-matrix, naturally impose the sum to obey the proper threshold behaviors. The imaginary part of Green's function and the T-matrix are directly related to observables such as scattering cross sections or invariant or missing mass distributions of hadron resonances. Thus we can determine their pole positions and residues by fitting their imaginary part to observables. We also test the new method by regarding the imaginary part of the $T$-matrix calculated exactly in a model theory as virtual experimental data. As a model theory, we take double-channel meson-baryon scatterings in the chiral unitary model with channels, $\overline{K}N (I=0)$, and $\pi\Sigma (I=0)$. By fitting the imaginary part of the $T$-matrix calculated in the model theory by that of the uniformized pole-sum, we obtain the pole positions and residues. Comparing the obtained results with those of the exact calculation in the model theory, we conclude that our new method works very well.
[ { "created": "Thu, 14 May 2020 14:38:33 GMT", "version": "v1" } ]
2020-11-11
[ [ "Yamada", "Wren", "" ], [ "Morimatsu", "Osamu", "" ] ]
We propose a new, simple model-independent method to extract information of near-threshold resonances, such as complex energies and residues. The method is based on the observation that the Green's function and the T-matrix can be represented as the sum of all poles, both bound and resonant poles, in the complex plane of a variable in which the Green's function and the T-matrix are single-valued functions. The symmetries of poles, which arise from the unitarity of the S-matrix, naturally impose the sum to obey the proper threshold behaviors. The imaginary part of Green's function and the T-matrix are directly related to observables such as scattering cross sections or invariant or missing mass distributions of hadron resonances. Thus we can determine their pole positions and residues by fitting their imaginary part to observables. We also test the new method by regarding the imaginary part of the $T$-matrix calculated exactly in a model theory as virtual experimental data. As a model theory, we take double-channel meson-baryon scatterings in the chiral unitary model with channels, $\overline{K}N (I=0)$, and $\pi\Sigma (I=0)$. By fitting the imaginary part of the $T$-matrix calculated in the model theory by that of the uniformized pole-sum, we obtain the pole positions and residues. Comparing the obtained results with those of the exact calculation in the model theory, we conclude that our new method works very well.
1807.10928
Renata Jora
Amir H. Fariborz and Renata Jora
Comment on scalar glueball mass
4 pages, 1 figure
null
null
null
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the interaction of scalar glueball with quark-antiquark and four-quark spinless meson fields within the framework of a generalized linear sigma model in which the trace anomaly of QCD is exactly realized. To determine the pure scalar glueball mass ($m_h$), we consider the decoupling limit in which the scalar glueball decouples from the meson fields. We find the exact relationship $m_h = 2\, h_0$ where $h_0$ is the vacuum expectation value of the scalar glueball field independent of the properties of the framework used.
[ { "created": "Sat, 28 Jul 2018 11:42:58 GMT", "version": "v1" } ]
2018-07-31
[ [ "Fariborz", "Amir H.", "" ], [ "Jora", "Renata", "" ] ]
We study the interaction of scalar glueball with quark-antiquark and four-quark spinless meson fields within the framework of a generalized linear sigma model in which the trace anomaly of QCD is exactly realized. To determine the pure scalar glueball mass ($m_h$), we consider the decoupling limit in which the scalar glueball decouples from the meson fields. We find the exact relationship $m_h = 2\, h_0$ where $h_0$ is the vacuum expectation value of the scalar glueball field independent of the properties of the framework used.
1511.08692
Jonas Michael Lindert
Stefan Kallweit, Jonas M. Lindert, Stefano Pozzorini, Marek Sch\"onherr, Philipp Maierh\"ofer
NLO QCD+EW predictions for V+jets including off-shell vector-boson decays and multijet merging
42 pages, 24 figures. V2: version accepted for publication in JHEP, results unchanged, appendix added discussing in detail multijet merging systematic uncertainties in the TeV range
null
10.1007/JHEP04(2016)021
DCPT/15/140, FR-PHENO-2015-014, IPPP/15/70, MCNET-15-23, MITP/15-108, ZU-TH 41/15
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present next-to-leading order (NLO) predictions including QCD and electroweak (EW) corrections for the production and decay of off-shell electroweak vector bosons in association with up to two jets at the 13 TeV LHC. All possible dilepton final states with zero, one or two charged leptons that can arise from off-shell W and Z bosons or photons are considered. All predictions are obtained using the automated implementation of NLO QCD+EW corrections in the OpenLoops matrix-element generator combined with the Munich and Sherpa Monte Carlo frameworks. Electroweak corrections play an especially important role in the context of BSM searches, due to the presence of large EW Sudakov logarithms at the TeV scale. In this kinematic regime, important observables such as the jet transverse momentum or the total transverse energy are strongly sensitive to multijet emissions. As a result, fixed-order NLO QCD+EW predictions are plagued by huge QCD corrections and poor theoretical precision. To remedy this problem we present an approximate method that allows for a simple and reliable implementation of NLO EW corrections in the MEPS@NLO multijet merging framework. Using this general approach we present an inclusive simulation of vector-boson production in association with jets that guarantees NLO QCD+EW accuracy in all phase space regions involving up to two resolved jets.
[ { "created": "Fri, 27 Nov 2015 14:50:10 GMT", "version": "v1" }, { "created": "Wed, 23 Mar 2016 07:49:05 GMT", "version": "v2" } ]
2016-05-04
[ [ "Kallweit", "Stefan", "" ], [ "Lindert", "Jonas M.", "" ], [ "Pozzorini", "Stefano", "" ], [ "Schönherr", "Marek", "" ], [ "Maierhöfer", "Philipp", "" ] ]
We present next-to-leading order (NLO) predictions including QCD and electroweak (EW) corrections for the production and decay of off-shell electroweak vector bosons in association with up to two jets at the 13 TeV LHC. All possible dilepton final states with zero, one or two charged leptons that can arise from off-shell W and Z bosons or photons are considered. All predictions are obtained using the automated implementation of NLO QCD+EW corrections in the OpenLoops matrix-element generator combined with the Munich and Sherpa Monte Carlo frameworks. Electroweak corrections play an especially important role in the context of BSM searches, due to the presence of large EW Sudakov logarithms at the TeV scale. In this kinematic regime, important observables such as the jet transverse momentum or the total transverse energy are strongly sensitive to multijet emissions. As a result, fixed-order NLO QCD+EW predictions are plagued by huge QCD corrections and poor theoretical precision. To remedy this problem we present an approximate method that allows for a simple and reliable implementation of NLO EW corrections in the MEPS@NLO multijet merging framework. Using this general approach we present an inclusive simulation of vector-boson production in association with jets that guarantees NLO QCD+EW accuracy in all phase space regions involving up to two resolved jets.
hep-ph/9709217
Uma Mahanta
Uma Mahanta
Effect of contact ineractions on higgs production cross-section at an $e^+e^-\to HZ$ collider
Plain Tex, 9 pages, No figures
Phys.Lett.B421:259-264,1998
10.1016/S0370-2693(97)01566-9
MRI_PHY/970719
hep-ph
null
New interactions appearing at a scale $\Lambda$ larger than the weak interaction scale v can affect physical processes at energies below $\Lambda$ through non-renormalizable $SU(3)\times SU(2)\times U(1)_y$ invariant operators added to the standard model Lagrangian. In this article we investigate the effect of flavor conserving contact interactions on the total cross-section for the process $e^+e^-\to HZ$ at $\sqs =500$ Gev. We find that for $\Lambda\approx 2.5 $ Tev, which is consistent with LEP and SLD asymmetry measurements on Z peak as well as theoretical estimates, these operators can increase the total cross-section by a factor of 3 relative to the SM for intermediate mass higgs boson.
[ { "created": "Tue, 2 Sep 1997 12:21:28 GMT", "version": "v1" } ]
2014-11-17
[ [ "Mahanta", "Uma", "" ] ]
New interactions appearing at a scale $\Lambda$ larger than the weak interaction scale v can affect physical processes at energies below $\Lambda$ through non-renormalizable $SU(3)\times SU(2)\times U(1)_y$ invariant operators added to the standard model Lagrangian. In this article we investigate the effect of flavor conserving contact interactions on the total cross-section for the process $e^+e^-\to HZ$ at $\sqs =500$ Gev. We find that for $\Lambda\approx 2.5 $ Tev, which is consistent with LEP and SLD asymmetry measurements on Z peak as well as theoretical estimates, these operators can increase the total cross-section by a factor of 3 relative to the SM for intermediate mass higgs boson.
hep-ph/0310269
Mark Gorenstein I.
Mark I. Gorenstein
Signals of Deconfinement Transition in Nucleus-Nucleus Collisions
Invited talk at the NATO Advanced Studies Institute "Structure and Dynamics of Elementary Matter", Kemer, Turkey, Sept. 22 - Oct. 2, 2003 12 pages, 5 figures
null
null
null
hep-ph
null
We discuss the energy dependence of hadron production in relativistic nucleus-nucleus collisions. Several `anomalies' in the energy dependence have been predicted as signals of the deconfinement phase transition and three of these signals are observed at the CERN SPS indicating that the onset of deconfinement in Pb+Pb collisions is located at about 30 A GeV.
[ { "created": "Wed, 22 Oct 2003 16:16:02 GMT", "version": "v1" } ]
2009-09-29
[ [ "Gorenstein", "Mark I.", "" ] ]
We discuss the energy dependence of hadron production in relativistic nucleus-nucleus collisions. Several `anomalies' in the energy dependence have been predicted as signals of the deconfinement phase transition and three of these signals are observed at the CERN SPS indicating that the onset of deconfinement in Pb+Pb collisions is located at about 30 A GeV.
0903.0370
C. A. de S. Pires
D. Cogollo, H. Diniz and C. A. de S. Pires
KeV right-handed neutrinos from type II seesaw mechanism in a 3-3-1 model
About 10 pages, no figures
null
10.1016/j.physletb.2009.05.060
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We adapt the type II seesaw mechanism to the framework of the 3-3-1 model with right-handed neutrinos. We emphasize that the mechanism is capable of generating small masses for the left-handed and right-handed neutrinos and the structure of the model allows that both masses arise from the same Yukawa coupling. For typical values of the free parameters of the model we may obtain at least one right-handed neutrino with mass in the KeV range. Right-handed neutrino with mass in this range is a viable candidate for the warm component of the dark matter existent in the universe.
[ { "created": "Mon, 2 Mar 2009 20:41:58 GMT", "version": "v1" } ]
2015-05-13
[ [ "Cogollo", "D.", "" ], [ "Diniz", "H.", "" ], [ "Pires", "C. A. de S.", "" ] ]
We adapt the type II seesaw mechanism to the framework of the 3-3-1 model with right-handed neutrinos. We emphasize that the mechanism is capable of generating small masses for the left-handed and right-handed neutrinos and the structure of the model allows that both masses arise from the same Yukawa coupling. For typical values of the free parameters of the model we may obtain at least one right-handed neutrino with mass in the KeV range. Right-handed neutrino with mass in this range is a viable candidate for the warm component of the dark matter existent in the universe.
2205.10240
Valerio De Luca
Valerio De Luca, Alex Kehagias, Antonio Riotto
On the Cosmological Stability of the Higgs Instability
27 pages, 4 figures. v2: matching published version
null
10.1088/1475-7516/2022/09/055
null
hep-ph astro-ph.CO gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Standard Model Higgs potential becomes unstable at large Higgs field values where its quartic coupling becomes negative. While the tunneling lifetime of our current electroweak vacuum is comfortably longer than the age of the universe, quantum fluctuations during inflation might push the Higgs over the barrier, forming patches which might be lethal for our universe. We study the cosmological evolution of such regions and find that, at least in the thin wall approximation, they may be harmless as they collapse due to the backreaction of the Higgs itself. The presence of the Standard Model Higgs instability can provide a novel mechanism to end inflation and to reheat the universe through the evaporation of the black holes left over by the collapse of the Higgs bubbles. The bound on the Hubble rate during inflation may be therefore relaxed.
[ { "created": "Fri, 20 May 2022 15:10:15 GMT", "version": "v1" }, { "created": "Sun, 11 Sep 2022 20:22:21 GMT", "version": "v2" } ]
2022-09-28
[ [ "De Luca", "Valerio", "" ], [ "Kehagias", "Alex", "" ], [ "Riotto", "Antonio", "" ] ]
The Standard Model Higgs potential becomes unstable at large Higgs field values where its quartic coupling becomes negative. While the tunneling lifetime of our current electroweak vacuum is comfortably longer than the age of the universe, quantum fluctuations during inflation might push the Higgs over the barrier, forming patches which might be lethal for our universe. We study the cosmological evolution of such regions and find that, at least in the thin wall approximation, they may be harmless as they collapse due to the backreaction of the Higgs itself. The presence of the Standard Model Higgs instability can provide a novel mechanism to end inflation and to reheat the universe through the evaporation of the black holes left over by the collapse of the Higgs bubbles. The bound on the Hubble rate during inflation may be therefore relaxed.
2105.06952
Roman H\"ollwieser
A. N. Ivanov, R. H\"ollwieser, N. I. Troitskaya, M. Wellenzohn, and Ya. A. Berdnikov
Radiative corrections of order $O(\alpha E_e/m_N)$ to Sirlin's radiative corrections of order $O(\alpha/\pi)$, induced by the hadronic structure of the neutron
accepted by Phys.Rev.D
Phys. Rev. D 103, 113007 (2021)
10.1103/PhysRevD.103.113007
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the contributions of the hadronic structure of the neutron to radiative $O(\alpha E_e/m_N)$ corrections (or the inner $O(\alpha E_e/m_N)$ RC) to the neutron beta decay, where $\alpha$, $E_e$ and $m_N$ are the fine-structure constant, the electron energy and the nucleon mass, respectively. We perform the calculation within the effective quantum field theory of strong low-energy pion-nucleon interactions described by the linear $\sigma$-model with chiral $SU(2) \times SU(2)$ symmetry and electroweak hadron-hadron, hadron-lepton and lepton-lepton interactions for the electron-lepton family with $SU(2)_L \times U(1)_Y$ symmetry of the Standard Electroweak Theory (Ivanov et al., Phys. Rev. D99, 093006 (2019)). We show that after renormalization, carried out in accordance with Sirlin's prescription (Sirlin, Phys. Rev. 164, 1767 (1967)), the inner $O(\alpha E_e/m_N)$ RC are of the order of a few parts of $10^{-5} - 10^{-4}$. This agrees well with the results obtained in (Ivanov et al., Phys. Rev. D99, 093006 (2019)).
[ { "created": "Fri, 14 May 2021 16:49:35 GMT", "version": "v1" } ]
2021-06-30
[ [ "Ivanov", "A. N.", "" ], [ "Höllwieser", "R.", "" ], [ "Troitskaya", "N. I.", "" ], [ "Wellenzohn", "M.", "" ], [ "Berdnikov", "Ya. A.", "" ] ]
We investigate the contributions of the hadronic structure of the neutron to radiative $O(\alpha E_e/m_N)$ corrections (or the inner $O(\alpha E_e/m_N)$ RC) to the neutron beta decay, where $\alpha$, $E_e$ and $m_N$ are the fine-structure constant, the electron energy and the nucleon mass, respectively. We perform the calculation within the effective quantum field theory of strong low-energy pion-nucleon interactions described by the linear $\sigma$-model with chiral $SU(2) \times SU(2)$ symmetry and electroweak hadron-hadron, hadron-lepton and lepton-lepton interactions for the electron-lepton family with $SU(2)_L \times U(1)_Y$ symmetry of the Standard Electroweak Theory (Ivanov et al., Phys. Rev. D99, 093006 (2019)). We show that after renormalization, carried out in accordance with Sirlin's prescription (Sirlin, Phys. Rev. 164, 1767 (1967)), the inner $O(\alpha E_e/m_N)$ RC are of the order of a few parts of $10^{-5} - 10^{-4}$. This agrees well with the results obtained in (Ivanov et al., Phys. Rev. D99, 093006 (2019)).
hep-ph/9906412
Alexander Kupco
Alexander Kupco
Cluster Hadronization in HERWIG 5.9
(8 p), to be published in the proceedings of the workshop on 'Monte Carlo Generators for HERA Physics' 1998/1999
null
null
null
hep-ph
null
The HERWIG 5.9 cluster hadronization model is briefly discussed here. It is shown that the model has peculiar behaviour when new heavy baryon resonances are included in the HERWIG 5.9 particle table. New fragmentation model is proposed to cure this problem and simple tuning of HERWIG 5.9 with this new model has been made using event shapes variables and identified particle momentum spectra in electron-positron interactions at LEPI. Finally, the predictions of the two hadronization models are compared.
[ { "created": "Thu, 17 Jun 1999 13:34:19 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kupco", "Alexander", "" ] ]
The HERWIG 5.9 cluster hadronization model is briefly discussed here. It is shown that the model has peculiar behaviour when new heavy baryon resonances are included in the HERWIG 5.9 particle table. New fragmentation model is proposed to cure this problem and simple tuning of HERWIG 5.9 with this new model has been made using event shapes variables and identified particle momentum spectra in electron-positron interactions at LEPI. Finally, the predictions of the two hadronization models are compared.
1109.3382
Hiroshi Yokoya
Tsedenbaljir Enkhbat, Wei-Shu Hou, Hiroshi Yokoya
Early LHC Phenomenology of Yukawa-bound Heavy Q\bar{Q} Mesons
14 pages, 12 figures; references added
Phys. Rev. D 84, 094013 (2011)
10.1103/PhysRevD.84.094013
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Current limits from the LHC on fourth generation quarks are already at the unitarity bound of 500 GeV or so. If they exist, the strong Yukawa couplings are turning nonperturbative, and may form bound states. We study the domain of m_{b'} and m_{t'} in the range of 500 to 700 GeV, where we expect binding energies are mainly of Yukawa origin, with QCD subdominant. To be consistent with electroweak precision tests, the t' and b' quarks have to be nearly degenerate, exhibiting a new "isospin". Comparing relativistic expansion with a relativistic bound state approach, we find the most interesting is the production of a color octet, isosinglet vector meson (a "gluon-prime") via q\bar{q} to \omega_8. Leading decay modes are \pi_8^\pm W^\mp, \pi_8^0Z^0, and constituent quark decay, with q\bar{q} and t\bar{t}' and b\bar{b}' subdominant. The color octet, isovector pseudoscalar \pi_8 meson decays via constituent quark decay, or to Wg. These decay rates are parameterized by the decay constant, the binding energy and mass differences, and V_{tb'}. For small V_{t'b}, one could have a spectacular signal of WWg, where a soft W accompanies a very massive Wg pair. In general, however, one has high multiplicity signals with b, W and t jet substructures that are not so different from t'\bar{t}' and b'\bar{b}' search.
[ { "created": "Thu, 15 Sep 2011 15:26:15 GMT", "version": "v1" }, { "created": "Thu, 22 Sep 2011 13:31:08 GMT", "version": "v2" } ]
2012-01-31
[ [ "Enkhbat", "Tsedenbaljir", "" ], [ "Hou", "Wei-Shu", "" ], [ "Yokoya", "Hiroshi", "" ] ]
Current limits from the LHC on fourth generation quarks are already at the unitarity bound of 500 GeV or so. If they exist, the strong Yukawa couplings are turning nonperturbative, and may form bound states. We study the domain of m_{b'} and m_{t'} in the range of 500 to 700 GeV, where we expect binding energies are mainly of Yukawa origin, with QCD subdominant. To be consistent with electroweak precision tests, the t' and b' quarks have to be nearly degenerate, exhibiting a new "isospin". Comparing relativistic expansion with a relativistic bound state approach, we find the most interesting is the production of a color octet, isosinglet vector meson (a "gluon-prime") via q\bar{q} to \omega_8. Leading decay modes are \pi_8^\pm W^\mp, \pi_8^0Z^0, and constituent quark decay, with q\bar{q} and t\bar{t}' and b\bar{b}' subdominant. The color octet, isovector pseudoscalar \pi_8 meson decays via constituent quark decay, or to Wg. These decay rates are parameterized by the decay constant, the binding energy and mass differences, and V_{tb'}. For small V_{t'b}, one could have a spectacular signal of WWg, where a soft W accompanies a very massive Wg pair. In general, however, one has high multiplicity signals with b, W and t jet substructures that are not so different from t'\bar{t}' and b'\bar{b}' search.