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hep-ph/9704379
null
Stanley J. Brodsky and Marek Karliner
Intrinsic Charm of Vector Mesons: A Possible Solution of the "rho pi" Puzzle
Latex, 11 pages
Phys.Rev.Lett.78:4682-4685,1997
10.1103/PhysRevLett.78.4682
SLAC-PUB-7463, TAUP 2417-97
hep-ph
null
An outstanding mystery of charmonium physics is why the J/\psi decays prominently to pseudoscalar plus vector meson channels, such as J/\psi -> \rho \pi and J/\psi -> K^*K, whereas the \psi'(2S) does not. We show that such decays of J/\psi and their suppression for \psi'(2S) follow naturally from the existence of intrinsic charm |qbar q cbar c> Fock components of the light vector mesons.
[ { "created": "Wed, 23 Apr 1997 00:25:37 GMT", "version": "v1" } ]
2008-11-26
[ [ "Brodsky", "Stanley J.", "" ], [ "Karliner", "Marek", "" ] ]
An outstanding mystery of charmonium physics is why the J/\psi decays prominently to pseudoscalar plus vector meson channels, such as J/\psi -> \rho \pi and J/\psi -> K^*K, whereas the \psi'(2S) does not. We show that such decays of J/\psi and their suppression for \psi'(2S) follow naturally from the existence of intrinsic charm |qbar q cbar c> Fock components of the light vector mesons.
hep-ph/9910374
Fredrik Soderberg
Bo Andersson, Fredrik Soderberg
The Diagonalisation of the Lund Fragmentation Model I
15 pages, 7 figures
Eur.Phys.J.C16:303-310,2000
10.1007/s100520050023
Lund University LU TP 99-32
hep-ph
null
We will in this note show that it is possible to diagonalise the Lund Fragmentation Model. We show that the basic original result, the Lund Area law, can be factorised into a product of transition operators, each describing the production of a single particle and the two adjacent breakup points (vertex positions) of the string field. The transition operator has a discrete spectrum of (orthonormal) eigenfunctions, describing the vertex positions (which in a dual way corresponds to the momentum transfers between the produced particles) and discrete eigenvalues, which only depend upon the particle produced. The eigenfunctions turn out to be the well-known two- dimensional harmonic oscillator functions and the eigenvalues are the analytic continuations of these functions to time-like values (corresponding to the particle mass). In this way all observables in the model can be expressed in terms of analytical formulas. In this note only the 1+1-dimensional version of the model is treated but we end with remarks on the extensions to gluonic radiation, transverse momentum generation etc, to be performed in future papers.
[ { "created": "Mon, 18 Oct 1999 08:20:03 GMT", "version": "v1" } ]
2011-09-13
[ [ "Andersson", "Bo", "" ], [ "Soderberg", "Fredrik", "" ] ]
We will in this note show that it is possible to diagonalise the Lund Fragmentation Model. We show that the basic original result, the Lund Area law, can be factorised into a product of transition operators, each describing the production of a single particle and the two adjacent breakup points (vertex positions) of the string field. The transition operator has a discrete spectrum of (orthonormal) eigenfunctions, describing the vertex positions (which in a dual way corresponds to the momentum transfers between the produced particles) and discrete eigenvalues, which only depend upon the particle produced. The eigenfunctions turn out to be the well-known two- dimensional harmonic oscillator functions and the eigenvalues are the analytic continuations of these functions to time-like values (corresponding to the particle mass). In this way all observables in the model can be expressed in terms of analytical formulas. In this note only the 1+1-dimensional version of the model is treated but we end with remarks on the extensions to gluonic radiation, transverse momentum generation etc, to be performed in future papers.
1910.12523
Qin-Tao Song
S. Kumano and Qin-Tao Song
Gluon transversity in polarized proton-deuteron Drell-Yan process
21 pages, 16 eps figure files, typos are corrected. Published in Phys. Rev. D 101 (2020) 054011
Phys. Rev. D 101, 054011 (2020)
10.1103/PhysRevD.101.054011
KEK-TH-2111, J-PARC-TH-0163
hep-ph hep-ex hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Nucleon spin structure functions have been investigated mainly by longitudinally-polarized ones for finding the origin of the nucleon spin. Other types of spin structure functions are transversely-polarized ones. In particular, quark transversity distributions in the nucleons have very different properties from the longitudinally-polarized quark distribution functions, especially in scaling violation, because they are decoupled from the gluon transversity, due to the fact that they are helicity-flip (chiral-odd) distributions. Such studies are valuable for finding not only the origin of the nucleon spin but also a signature on physics beyond the standard model, because the electric dipole moment of the neutron is proportional to the transversity distributions. Now, there is experimental progress on the quark transversity distributions; however, there is no experimental information on gluon transversity. In fact, the gluon transversity does not exist for the spin-1/2 nucleon due to the helicity-conservation constraint. One needs a hadron with spin more than or equal to one, so that the helicity flip of two units is allowed. A stable spin-1 target is, for example, the deuteron for studying the gluon transversity. In this work, we propose a possibility for finding the gluon transversity at hadron-accelerator facilities, especially in the proton-deuteron Drell-Yan process with the linearly-polarized deuteron, by showing theoretical formalism and numerical results. We show the dependencies of the Drell-Yan cross section on the dimuon-mass squared $M_{\mu\mu}^{\,2}$, the dimuon transverse-momentum $q_T$, the dimuon rapidity $y$ in the center-of-momentum frame, and the magnitude of the gluon transversity $\Delta_T g$.
[ { "created": "Mon, 28 Oct 2019 09:53:40 GMT", "version": "v1" }, { "created": "Tue, 18 Feb 2020 04:25:13 GMT", "version": "v2" }, { "created": "Thu, 12 Mar 2020 02:45:27 GMT", "version": "v3" } ]
2020-03-18
[ [ "Kumano", "S.", "" ], [ "Song", "Qin-Tao", "" ] ]
Nucleon spin structure functions have been investigated mainly by longitudinally-polarized ones for finding the origin of the nucleon spin. Other types of spin structure functions are transversely-polarized ones. In particular, quark transversity distributions in the nucleons have very different properties from the longitudinally-polarized quark distribution functions, especially in scaling violation, because they are decoupled from the gluon transversity, due to the fact that they are helicity-flip (chiral-odd) distributions. Such studies are valuable for finding not only the origin of the nucleon spin but also a signature on physics beyond the standard model, because the electric dipole moment of the neutron is proportional to the transversity distributions. Now, there is experimental progress on the quark transversity distributions; however, there is no experimental information on gluon transversity. In fact, the gluon transversity does not exist for the spin-1/2 nucleon due to the helicity-conservation constraint. One needs a hadron with spin more than or equal to one, so that the helicity flip of two units is allowed. A stable spin-1 target is, for example, the deuteron for studying the gluon transversity. In this work, we propose a possibility for finding the gluon transversity at hadron-accelerator facilities, especially in the proton-deuteron Drell-Yan process with the linearly-polarized deuteron, by showing theoretical formalism and numerical results. We show the dependencies of the Drell-Yan cross section on the dimuon-mass squared $M_{\mu\mu}^{\,2}$, the dimuon transverse-momentum $q_T$, the dimuon rapidity $y$ in the center-of-momentum frame, and the magnitude of the gluon transversity $\Delta_T g$.
0808.2897
C. A. Dominguez
C.A. Dominguez, H. Falomir, M. Ipinza, M. Loewe, and J.C. Rojas
Induced electromagnetic fields in non-linear QED
Minor typos have been corrected
null
10.1142/S0217732309030503
UCT-TP-274/08
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Euler-Heisenberg effective Lagrangian is used to obtain general expressions for electric and magnetic fields induced by non-linearity, to leading order in the non-linear expansion parameter, and for quasistatic situations. These expressions are then used to compute the induced electromagnetic fields due to a spherical shell with uniform charge distribution on the surface, in the presence of an external constant magnetic field. The induced electric field contains several multipole terms with unusual angular dependences. Most importantly, the leading term of the induced magnetic field is due to an induced magnetic dipole moment.
[ { "created": "Thu, 21 Aug 2008 10:23:26 GMT", "version": "v1" }, { "created": "Fri, 14 Nov 2008 11:31:20 GMT", "version": "v2" } ]
2015-05-13
[ [ "Dominguez", "C. A.", "" ], [ "Falomir", "H.", "" ], [ "Ipinza", "M.", "" ], [ "Loewe", "M.", "" ], [ "Rojas", "J. C.", "" ] ]
The Euler-Heisenberg effective Lagrangian is used to obtain general expressions for electric and magnetic fields induced by non-linearity, to leading order in the non-linear expansion parameter, and for quasistatic situations. These expressions are then used to compute the induced electromagnetic fields due to a spherical shell with uniform charge distribution on the surface, in the presence of an external constant magnetic field. The induced electric field contains several multipole terms with unusual angular dependences. Most importantly, the leading term of the induced magnetic field is due to an induced magnetic dipole moment.
2103.01617
Sudip Jana
Guo-yuan Huang, Sudip Jana, Farinaldo S. Queiroz, Werner Rodejohann
Probing the $R_{K^{(*)}}$ Anomaly at a Muon Collider
8 pages + references, 5 figures, matches published version
Phys. Rev. D 105, 015013 (2022)
10.1103/PhysRevD.105.015013
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
The LHCb measurements of the $\mu / e$ ratio in $B \to K \ell \ell$ decays $(R_{K^{}})$ indicate a deficit with respect to the Standard Model prediction, supporting earlier hints of lepton universality violation observed in the $R_{K^{(*)}}$ ratio. Possible explanations of these $B$-physics anomalies include heavy $Z'$ bosons or scalar and vector leptoquarks mediating $b \to s \mu^+ \mu^- $. We note that a muon collider can directly measure this process via $\mu^+ \mu^- \to b \bar s$ and can shed light on the lepton non-universality scenario. Investigating currently discussed center-of-mass energies $\sqrt{s} = 3$, 6 and 10 TeV, we show that the parameter space of $Z'$ and leptoquark solutions to the $R_{K^{(*)}}$ anomalies can be mostly covered. Effective operators explaining the anomalies can be probed with the muon collider setup $\sqrt{s} = 6~{\rm TeV}$ and integrated luminosity $L = 4~{\rm ab^{-1}}$.
[ { "created": "Tue, 2 Mar 2021 10:13:48 GMT", "version": "v1" }, { "created": "Sun, 28 Mar 2021 12:19:48 GMT", "version": "v2" }, { "created": "Fri, 10 Dec 2021 13:52:05 GMT", "version": "v3" } ]
2022-01-12
[ [ "Huang", "Guo-yuan", "" ], [ "Jana", "Sudip", "" ], [ "Queiroz", "Farinaldo S.", "" ], [ "Rodejohann", "Werner", "" ] ]
The LHCb measurements of the $\mu / e$ ratio in $B \to K \ell \ell$ decays $(R_{K^{}})$ indicate a deficit with respect to the Standard Model prediction, supporting earlier hints of lepton universality violation observed in the $R_{K^{(*)}}$ ratio. Possible explanations of these $B$-physics anomalies include heavy $Z'$ bosons or scalar and vector leptoquarks mediating $b \to s \mu^+ \mu^- $. We note that a muon collider can directly measure this process via $\mu^+ \mu^- \to b \bar s$ and can shed light on the lepton non-universality scenario. Investigating currently discussed center-of-mass energies $\sqrt{s} = 3$, 6 and 10 TeV, we show that the parameter space of $Z'$ and leptoquark solutions to the $R_{K^{(*)}}$ anomalies can be mostly covered. Effective operators explaining the anomalies can be probed with the muon collider setup $\sqrt{s} = 6~{\rm TeV}$ and integrated luminosity $L = 4~{\rm ab^{-1}}$.
1902.08585
Clara Peset
Claudia Frugiuele, Jes\'us P\'erez-R\'ios, Clara Peset
Current and future perspectives of positronium and muonium spectroscopy as dark sectors probe
8 pages, 6 figures. Version changed to match journal version. Figures updated
Phys. Rev. D 100, 015010 (2019)
10.1103/PhysRevD.100.015010
TUM-1188/19
hep-ph hep-ex physics.atom-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Positronium and Muonium are purely leptonic atoms and hence free of an internal sub-structure. This qualifies them as potentially well suited systems to probe the existence of physics beyond the Standard Model. We hence carry out a comprehensive study of the sensitivity of current Positronium and Muonium precision spectroscopy to several new physics scenarios. By taking properly into account existing experimental and astrophysical probes, we define clear experimental targets to probe new physics via precise spectroscopy. For Positronium we find that, in order for the spectroscopy bounds to reach a sensitivity comparable to the electron gyromagnetic factor, an improvement of roughly five orders of magnitude from state-of-the-art precision is required, which would be a challenge based on current technology. More promising is instead the potential reach of Muonium spectroscopy: in the next few years experiments like Mu-MASS at PSI will probe new regions of the parameter space testing the existence of medium/short range (MeV and above) spin-dependent and spin-independent dark forces between electrons and muons.
[ { "created": "Fri, 22 Feb 2019 18:08:52 GMT", "version": "v1" }, { "created": "Thu, 26 Sep 2019 08:54:23 GMT", "version": "v2" } ]
2019-09-27
[ [ "Frugiuele", "Claudia", "" ], [ "Pérez-Ríos", "Jesús", "" ], [ "Peset", "Clara", "" ] ]
Positronium and Muonium are purely leptonic atoms and hence free of an internal sub-structure. This qualifies them as potentially well suited systems to probe the existence of physics beyond the Standard Model. We hence carry out a comprehensive study of the sensitivity of current Positronium and Muonium precision spectroscopy to several new physics scenarios. By taking properly into account existing experimental and astrophysical probes, we define clear experimental targets to probe new physics via precise spectroscopy. For Positronium we find that, in order for the spectroscopy bounds to reach a sensitivity comparable to the electron gyromagnetic factor, an improvement of roughly five orders of magnitude from state-of-the-art precision is required, which would be a challenge based on current technology. More promising is instead the potential reach of Muonium spectroscopy: in the next few years experiments like Mu-MASS at PSI will probe new regions of the parameter space testing the existence of medium/short range (MeV and above) spin-dependent and spin-independent dark forces between electrons and muons.
1106.0976
Anatoly Butkevich
A.V. Butkevich (Moscow, INR) and D. Perevalov (FNAL)
Neutrino neutral-current elastic scattering on 12C
23 pages, 8 figures
Phys.Rev.C84:015501,2011
10.1103/PhysRevC.84.015501
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The neutral current elastic scattering of neutrinos on Carbon and $CH_2$ targets is computed using the relativistic distorted-wave impulse approximation with relativistic optical potential. Results for exclusive and inclusive neutrino reactions on ${}^{12}$C target are presented. We show that the nuclear effects on the shape of four-momentum transferred squared distribution $d\sigma/dQ^2_{QE}$ in neutrino neutral-current and charged-current quasi-elastic scattering are similar. We also calculate flux-averaged neutral current elastic differential cross section $d\sigma/dQ^2_{QE}$ for neutrino scattering from $CH_2$, as well as, the neutral-current to charged-current cross section ratio as functions of $Q^2_{QE}$. The value of axial mass $M_A$ is extracted from a fit of $d\sigma/dQ^2_{QE}$ cross section measured in MiniBooNE experiment. The extracted value of $M_A=1.28\pm 0.05$ GeV is consistent within errors with the MiniBooNE result. Additionally, for proton kinetic energies above the Cherenkov threshold, the strange quark contribution to the neutral current axial vector form factor at $Q^2_{QE}=0$, $\Delta s$, was extracted from a fit of MiniBoone data for $\nu p \to \nu p$ to $\nu N \to \nu N$ cross section ratio. This value is found to be $\Delta s=-0.11\pm 0.36$
[ { "created": "Mon, 6 Jun 2011 07:42:23 GMT", "version": "v1" } ]
2011-08-08
[ [ "Butkevich", "A. V.", "", "Moscow, INR" ], [ "Perevalov", "D.", "", "FNAL" ] ]
The neutral current elastic scattering of neutrinos on Carbon and $CH_2$ targets is computed using the relativistic distorted-wave impulse approximation with relativistic optical potential. Results for exclusive and inclusive neutrino reactions on ${}^{12}$C target are presented. We show that the nuclear effects on the shape of four-momentum transferred squared distribution $d\sigma/dQ^2_{QE}$ in neutrino neutral-current and charged-current quasi-elastic scattering are similar. We also calculate flux-averaged neutral current elastic differential cross section $d\sigma/dQ^2_{QE}$ for neutrino scattering from $CH_2$, as well as, the neutral-current to charged-current cross section ratio as functions of $Q^2_{QE}$. The value of axial mass $M_A$ is extracted from a fit of $d\sigma/dQ^2_{QE}$ cross section measured in MiniBooNE experiment. The extracted value of $M_A=1.28\pm 0.05$ GeV is consistent within errors with the MiniBooNE result. Additionally, for proton kinetic energies above the Cherenkov threshold, the strange quark contribution to the neutral current axial vector form factor at $Q^2_{QE}=0$, $\Delta s$, was extracted from a fit of MiniBoone data for $\nu p \to \nu p$ to $\nu N \to \nu N$ cross section ratio. This value is found to be $\Delta s=-0.11\pm 0.36$
1007.4907
Sergey Afonin
S.S. Afonin
A five-dimensional effective model for excited light mesons
4 pages, to appear in the proceedings of MENU2010
PoS QFTHEP2010:051,2011
10.1063/1.3647215
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the usual holographic approach to QCD, the meson spectrum is generated due to a non-trivial 5-dimensional background. We propose an alternative 5-dimensional scenario in which the spectrum emerges due to coupling to a scalar field whose condensation is supposed to be dual to the formation of gluon condensate and mimics the scale anomaly in QCD. The spectrum of model has finite number of discrete states plus continuum and reveals a Regge-like behavior in the strong coupling regime.
[ { "created": "Wed, 28 Jul 2010 09:23:15 GMT", "version": "v1" } ]
2015-05-19
[ [ "Afonin", "S. S.", "" ] ]
In the usual holographic approach to QCD, the meson spectrum is generated due to a non-trivial 5-dimensional background. We propose an alternative 5-dimensional scenario in which the spectrum emerges due to coupling to a scalar field whose condensation is supposed to be dual to the formation of gluon condensate and mimics the scale anomaly in QCD. The spectrum of model has finite number of discrete states plus continuum and reveals a Regge-like behavior in the strong coupling regime.
2106.00345
Igor Ivanov
Pengcheng Zhao, Igor P. Ivanov, Pengming Zhang
Decay of the vortex muon
12 pages, 8 figures; v2: a numerical error corrected, plots updated, text improved, the main results stay unchanged, matches the published version
Phys. Rev. D 104, 036003 (2021)
10.1103/PhysRevD.104.036003
null
hep-ph quant-ph
http://creativecommons.org/licenses/by-sa/4.0/
Muon decay is self-analyzing: the spectral-angular distribution of the emitted electron reveals the spin orientation of the polarized muon. Here, we show that the same feature applies to muons in non-plane-wave states and helps reveal the rich polarization opportunities available. We focus on the so-called vortex states, in which the muon carries a non-zero orbital angular momentum with respect to the average propagation direction and exhibits a cone structure in the momentum distribution. We compute the spectrum and the angular distribution of the electrons emitted in decays of vortex muons and show that the most revealing observable is not the angular distribution but the fixed-angle electron spectra. Even for very small cone opening angles of the vortex muons, it will be easy to observe significant modifications of the electron spectra which would allow one to distinguish vortex muons from approximately plane wave muons, as well as to differentiate among various polarization states. These features will be the key to tracking the evolution of vortex muons in external magnetic fields.
[ { "created": "Tue, 1 Jun 2021 09:33:21 GMT", "version": "v1" }, { "created": "Sat, 14 Aug 2021 08:56:23 GMT", "version": "v2" } ]
2021-08-17
[ [ "Zhao", "Pengcheng", "" ], [ "Ivanov", "Igor P.", "" ], [ "Zhang", "Pengming", "" ] ]
Muon decay is self-analyzing: the spectral-angular distribution of the emitted electron reveals the spin orientation of the polarized muon. Here, we show that the same feature applies to muons in non-plane-wave states and helps reveal the rich polarization opportunities available. We focus on the so-called vortex states, in which the muon carries a non-zero orbital angular momentum with respect to the average propagation direction and exhibits a cone structure in the momentum distribution. We compute the spectrum and the angular distribution of the electrons emitted in decays of vortex muons and show that the most revealing observable is not the angular distribution but the fixed-angle electron spectra. Even for very small cone opening angles of the vortex muons, it will be easy to observe significant modifications of the electron spectra which would allow one to distinguish vortex muons from approximately plane wave muons, as well as to differentiate among various polarization states. These features will be the key to tracking the evolution of vortex muons in external magnetic fields.
2306.15474
Wolfgang Lucha
Wolfgang Lucha
Mission Target: Tetraquark Mesons of Flavour-Cryptoexotic Type
12 pages, 2 figures
Universe 9 (2023) 8, 358
10.3390/universe9080358
null
hep-ph hep-th nucl-th
http://creativecommons.org/licenses/by/4.0/
Currently, flavour-cryptoexotic tetraquarks form the most common sort of all experimentally established exotic multiquark hadrons. This note points out a few promising concepts that should help improve theoretical (but, for several reasons, not quite straightforward) analyses of such kind of states: among others, their scope of application encompasses the strong interactions in the limit of (arbitrarily) large numbers of colours, and equally analytical and nonperturbative approaches to multiquark states.
[ { "created": "Tue, 27 Jun 2023 13:52:05 GMT", "version": "v1" } ]
2023-08-02
[ [ "Lucha", "Wolfgang", "" ] ]
Currently, flavour-cryptoexotic tetraquarks form the most common sort of all experimentally established exotic multiquark hadrons. This note points out a few promising concepts that should help improve theoretical (but, for several reasons, not quite straightforward) analyses of such kind of states: among others, their scope of application encompasses the strong interactions in the limit of (arbitrarily) large numbers of colours, and equally analytical and nonperturbative approaches to multiquark states.
hep-ph/9708410
null
Z. Lalak (ITP Warsaw, MPI Munich)
Anomalous D-term, dynamical supersymmetry breaking and dynamical gauge couplings
24 pages, Latex, 1 figure, uses psfig.sty
Nucl.Phys. B521 (1998) 37-57
10.1016/S0550-3213(98)00213-2
MPI-PhT-97-017
hep-ph
null
We analyze the structure of the vacuum and supersymmetry breaking pattern in Fayet-Iliopoulos models with dynamical gauge coupling and planck-scale value of the F-I parameter. We show that in this class of models supersymmetry is generically broken, but the mere presence of the D-term is not sufficient to stop the running away of the modulus responsible for the value of the gauge coupling - the dilaton. To stabilize the dilaton, one has to include an additional dilaton-dependent part in the superpotential. The presence of the large D-term gives rise to the mixed dilaton/D-term dominated scenarios of susy breaking, which allow horizontal hierarchy generation. Models which can serve as secluded sectors in gauge mediation scenarios are discussed. It is shown that when the F-I parameter and the gauge coupling are dynamical variables, the D-term dominated Universe does not allow for an inflationary period.
[ { "created": "Wed, 20 Aug 1997 15:36:14 GMT", "version": "v1" } ]
2009-10-30
[ [ "Lalak", "Z.", "", "ITP Warsaw, MPI Munich" ] ]
We analyze the structure of the vacuum and supersymmetry breaking pattern in Fayet-Iliopoulos models with dynamical gauge coupling and planck-scale value of the F-I parameter. We show that in this class of models supersymmetry is generically broken, but the mere presence of the D-term is not sufficient to stop the running away of the modulus responsible for the value of the gauge coupling - the dilaton. To stabilize the dilaton, one has to include an additional dilaton-dependent part in the superpotential. The presence of the large D-term gives rise to the mixed dilaton/D-term dominated scenarios of susy breaking, which allow horizontal hierarchy generation. Models which can serve as secluded sectors in gauge mediation scenarios are discussed. It is shown that when the F-I parameter and the gauge coupling are dynamical variables, the D-term dominated Universe does not allow for an inflationary period.
hep-ph/9808262
Stefano Frixione
D. de Florian (CERN), S. Frixione (ETH), A. Signer (CERN) and W. Vogelsang (CERN)
Next-to-leading order jet cross sections in polarized hadronic collisions
21 pages Latex, uses amssymb.sty and epsfig.sty, 10 ps figures included
Nucl.Phys. B539 (1999) 455-476
10.1016/S0550-3213(98)00673-7
CERN-TH/98-255, ETH-TH/98-21
hep-ph
null
We present a next-to-leading order computation in QCD of one-jet and two-jet cross sections in polarized hadronic collisions. Our results are obtained in the framework of a general formalism that deals with soft and collinear singularities using the subtraction method. We construct a Monte Carlo program that generates events at the partonic level. We use this code to give phenomenological predictions for $pp$ collisions at $\sqrt{S}=500$ GeV, relevant for the spin physics program at RHIC. The possibility of using jet data to constrain the poorly known polarized parton densities is examined.
[ { "created": "Fri, 7 Aug 1998 15:34:08 GMT", "version": "v1" } ]
2009-10-31
[ [ "de Florian", "D.", "", "CERN" ], [ "Frixione", "S.", "", "ETH" ], [ "Signer", "A.", "", "CERN" ], [ "Vogelsang", "W.", "", "CERN" ] ]
We present a next-to-leading order computation in QCD of one-jet and two-jet cross sections in polarized hadronic collisions. Our results are obtained in the framework of a general formalism that deals with soft and collinear singularities using the subtraction method. We construct a Monte Carlo program that generates events at the partonic level. We use this code to give phenomenological predictions for $pp$ collisions at $\sqrt{S}=500$ GeV, relevant for the spin physics program at RHIC. The possibility of using jet data to constrain the poorly known polarized parton densities is examined.
2306.11090
Anna M. Suliga
Anna M. Suliga and John F. Beacom
Distinctive nuclear signatures of low-energy atmospheric neutrinos
13 pages, 7 figures, 1 appendix. Minor changes, matches version published in Phys. Rev. D
Phys. Rev. D 108, 043035 (2023)
10.1103/PhysRevD.108.043035
N3AS-23-002, INT-PUB-23-020
hep-ph astro-ph.HE nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
New probes of neutrino mixing are needed to advance precision studies. One promising direction is via the detection of low-energy atmospheric neutrinos (below a few hundred MeV), to which a variety of near-term experiments will have much-improved sensitivity. Here we focus on probing these neutrinos through distinctive nuclear signatures of exclusive neutrino-carbon interactions -- those that lead to detectable nuclear-decay signals with low backgrounds -- in both neutral-current and charged-current channels. The neutral-current signature is a line at 15.11 MeV and the charged-current signatures are two- or three-fold coincidences with delayed decays. We calculate the prospects for identifying such events in the Jiangmen Underground Neutrino Observatory (JUNO), a large-scale liquid-scintillator detector. A five-year exposure would yield about 16 neutral-current events (all flavors) and about 16 charged-current events (mostly from $\nu_e + \bar{\nu}_e$, with some from $\nu_\mu + \bar{\nu}_\mu$), and thus roughly 25\% uncertainties on each of their rates. Our results show the potential of JUNO to make the first identified measurement of sub-100 MeV atmospheric neutrinos. They also are a step towards multi-detector studies of low-energy atmospheric neutrinos, with the goal of identifying additional distinctive nuclear signatures for carbon and other targets.
[ { "created": "Mon, 19 Jun 2023 18:00:01 GMT", "version": "v1" }, { "created": "Thu, 31 Aug 2023 19:36:43 GMT", "version": "v2" } ]
2023-09-04
[ [ "Suliga", "Anna M.", "" ], [ "Beacom", "John F.", "" ] ]
New probes of neutrino mixing are needed to advance precision studies. One promising direction is via the detection of low-energy atmospheric neutrinos (below a few hundred MeV), to which a variety of near-term experiments will have much-improved sensitivity. Here we focus on probing these neutrinos through distinctive nuclear signatures of exclusive neutrino-carbon interactions -- those that lead to detectable nuclear-decay signals with low backgrounds -- in both neutral-current and charged-current channels. The neutral-current signature is a line at 15.11 MeV and the charged-current signatures are two- or three-fold coincidences with delayed decays. We calculate the prospects for identifying such events in the Jiangmen Underground Neutrino Observatory (JUNO), a large-scale liquid-scintillator detector. A five-year exposure would yield about 16 neutral-current events (all flavors) and about 16 charged-current events (mostly from $\nu_e + \bar{\nu}_e$, with some from $\nu_\mu + \bar{\nu}_\mu$), and thus roughly 25\% uncertainties on each of their rates. Our results show the potential of JUNO to make the first identified measurement of sub-100 MeV atmospheric neutrinos. They also are a step towards multi-detector studies of low-energy atmospheric neutrinos, with the goal of identifying additional distinctive nuclear signatures for carbon and other targets.
hep-ph/0206267
Peter Schweitzer
A.V. Efremov (Dubna, JINR), K. Goeke (Ruhr U., Bochum), P. Schweitzer (Pavia U.)
Azimuthal asymmetries and Collins analyzing power
5 pages, 7 figures. Talk presented by A.V. Efremov at DIS2002, Cracow, Poland, 30 April to 4 May 2002. To appear in Acta Physica Polonica B
Nucl.Phys. A711 (2002) 84-88; Acta Phys.Polon. B33 (2002) 3755-3760
10.1016/S0375-9474(02)01199-5
RUB-TP2-10-02
hep-ph
null
Spin azimuthal asymmetries in pion electro-production in deep inelastic scattering off longitudinally polarized protons, measured by HERMES, are well reproduced theoretically with no adjustable parameters. Predictions for azimuthal asymmetries for a longitudinally polarized deuteron target are given. The z-dependence of the Collins fragmentation function is extracted. The first information on e(x) is extracted from CLAS A_LU asymmetry.
[ { "created": "Wed, 26 Jun 2002 11:00:57 GMT", "version": "v1" } ]
2015-06-25
[ [ "Efremov", "A. V.", "", "Dubna, JINR" ], [ "Goeke", "K.", "", "Ruhr U., Bochum" ], [ "Schweitzer", "P.", "", "Pavia U." ] ]
Spin azimuthal asymmetries in pion electro-production in deep inelastic scattering off longitudinally polarized protons, measured by HERMES, are well reproduced theoretically with no adjustable parameters. Predictions for azimuthal asymmetries for a longitudinally polarized deuteron target are given. The z-dependence of the Collins fragmentation function is extracted. The first information on e(x) is extracted from CLAS A_LU asymmetry.
hep-ph/0607270
Sabine Kraml
S. Kraml
LHC / ILC / Cosmology Interplay
7 pages, contribution to the proceedings of the IX Workshop on High Energy Physics Phenomenology (WHEPP-9), 3-14 Jan 2006, Bhubaneswar, India
Pramana67:597-606,2006
10.1007/s12043-006-0055-4
null
hep-ph
null
There is a strong and growing interplay between particle physics and cosmology. In this talk, I discuss some aspects of this interplay concerning dark matter candidates put forth by theories beyond the Standard Model. In explaining the requirements for collider tests of such dark matter candidates, I focus in particular on the case of the lightest neutralino in the MSSM.
[ { "created": "Tue, 25 Jul 2006 09:19:52 GMT", "version": "v1" } ]
2008-11-26
[ [ "Kraml", "S.", "" ] ]
There is a strong and growing interplay between particle physics and cosmology. In this talk, I discuss some aspects of this interplay concerning dark matter candidates put forth by theories beyond the Standard Model. In explaining the requirements for collider tests of such dark matter candidates, I focus in particular on the case of the lightest neutralino in the MSSM.
2012.01810
Tolga Altinoluk
Tolga Altinoluk, N\'estor Armesto, Alex Kovner, Michael Lublinsky, Vladimir V. Skokov
Angular correlations in pA collisions from CGC: multiplicity and mean transverse momentum dependence of $v_2$
28 pages, 4 figures
null
10.1140/epjc/s10052-021-09373-5
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Within the dense-dilute Color Glass Condensate approach, and using the Golec-Biernat-Wuesthoff model for the dipole scattering amplitude, we calculate $v_2^2$ as well as the correlations between $v_2^2$ and both the total multiplicity and the mean transverse momentum of produced particles. We find that the correlations are generally very small consistent with the observations. We note an interesting sharp change in the value of $v^2_2$ as well as of its correlations as a function of the width of the transverse momentum bin. This crossover is associated with the change from Bose enhancement dominance of the correlation for narrow bin to HBT dominated correlations for larger bin width.
[ { "created": "Thu, 3 Dec 2020 10:37:30 GMT", "version": "v1" } ]
2021-07-21
[ [ "Altinoluk", "Tolga", "" ], [ "Armesto", "Néstor", "" ], [ "Kovner", "Alex", "" ], [ "Lublinsky", "Michael", "" ], [ "Skokov", "Vladimir V.", "" ] ]
Within the dense-dilute Color Glass Condensate approach, and using the Golec-Biernat-Wuesthoff model for the dipole scattering amplitude, we calculate $v_2^2$ as well as the correlations between $v_2^2$ and both the total multiplicity and the mean transverse momentum of produced particles. We find that the correlations are generally very small consistent with the observations. We note an interesting sharp change in the value of $v^2_2$ as well as of its correlations as a function of the width of the transverse momentum bin. This crossover is associated with the change from Bose enhancement dominance of the correlation for narrow bin to HBT dominated correlations for larger bin width.
hep-ph/0605057
York Schroder
York Schroder
Weak-coupling expansion of the hot QCD pressure
11 pg, Talk given at 29th Johns Hopkins Workshop in Theoretical Physics: Strong Matter in the Heavens, Budapest, Hungary, 1-3 Aug 2005
PoS JHW2005:029,2006
null
null
hep-ph
null
We review recent progress made in determining the pressure of hot QCD up to the first non-perturbative term in its weak-coupling expansion.
[ { "created": "Fri, 5 May 2006 08:16:43 GMT", "version": "v1" } ]
2007-05-23
[ [ "Schroder", "York", "" ] ]
We review recent progress made in determining the pressure of hot QCD up to the first non-perturbative term in its weak-coupling expansion.
0809.4613
Boris Kopeliovich
B.Z. Kopeliovich, H.-J. Pirner, I.K. Potashnikova, Ivan Schmidt, A.V. Tarasov, O.O. Voskresenskaya
Quantum-mechanical description of in-medium fragmentation
20 pages, 7 figures
Phys.Rev.C78:055204,2008
10.1103/PhysRevC.78.055204
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a quantum-mechanical description of quark-hadron fragmentation in a nuclear environment. It employs the path-integral formulation of quantum mechanics, which takes care of all phases and interferences, and which contains all relevant time scales, like production, coherence, formation, etc. The cross section includes the probability of pre-hadron (colorless dipole) production both inside and outside the medium. Moreover, it also includes inside-outside production, which is a typical quantum-mechanical interference effect (like twin-slit electron propagation). We observe a substantial suppression caused by the medium, even if the pre-hadron is produced outside the medium and no energy loss is involved. This important source of suppression is missed in the usual energy-loss scenario interpreting the effect of jet quenching observed in heavy ion collisions. This may be one of the reasons of a too large gluon density, reported by such analyzes.
[ { "created": "Fri, 26 Sep 2008 13:26:05 GMT", "version": "v1" }, { "created": "Sat, 27 Sep 2008 18:16:15 GMT", "version": "v2" } ]
2010-04-21
[ [ "Kopeliovich", "B. Z.", "" ], [ "Pirner", "H. -J.", "" ], [ "Potashnikova", "I. K.", "" ], [ "Schmidt", "Ivan", "" ], [ "Tarasov", "A. V.", "" ], [ "Voskresenskaya", "O. O.", "" ] ]
We present a quantum-mechanical description of quark-hadron fragmentation in a nuclear environment. It employs the path-integral formulation of quantum mechanics, which takes care of all phases and interferences, and which contains all relevant time scales, like production, coherence, formation, etc. The cross section includes the probability of pre-hadron (colorless dipole) production both inside and outside the medium. Moreover, it also includes inside-outside production, which is a typical quantum-mechanical interference effect (like twin-slit electron propagation). We observe a substantial suppression caused by the medium, even if the pre-hadron is produced outside the medium and no energy loss is involved. This important source of suppression is missed in the usual energy-loss scenario interpreting the effect of jet quenching observed in heavy ion collisions. This may be one of the reasons of a too large gluon density, reported by such analyzes.
1102.0492
Reinard Primulando
Gardner Marshall and Reinard Primulando
The Galactic Center Region Gamma Ray Excess from A Supersymmetric Leptophilic Higgs Model
21 pages LaTeX, 1 eps figure, 6 tables. Version accepted for publication in JHEP
JHEP 1105:026,2011
10.1007/JHEP05(2011)026
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a recent paper by Hooper and Goodenough, data from the Fermi Gamma Ray Telescope was analyzed and an excess of gamma rays was claimed to be found in the emission spectrum from the Galactic Center Region. Hooper and Goodenough suggest that the claimed excess can be well explained by 7-10 GeV annihilating dark matter with a power law density profile if the dark matter annihilates predominantly to tau pairs. In this paper we present such a dark matter model by extending the MSSM to include four Higgs doublets and one scalar singlet. A Z2 symmetry is imposed that enforces a Yukawa structure so that the up quarks, down quarks, and leptons each receive mass from a distinct doublet. This leads to an enhanced coupling of scalars to leptons and allows the model to naturally achieve the required phenomenology in order to explain the gamma ray excess. Our model yields the correct dark matter thermal relic density and avoids collider bounds from measurements of the Z width as well as direct production at LEP.
[ { "created": "Wed, 2 Feb 2011 17:08:22 GMT", "version": "v1" }, { "created": "Mon, 7 Feb 2011 20:56:39 GMT", "version": "v2" }, { "created": "Tue, 10 May 2011 18:33:56 GMT", "version": "v3" } ]
2011-05-11
[ [ "Marshall", "Gardner", "" ], [ "Primulando", "Reinard", "" ] ]
In a recent paper by Hooper and Goodenough, data from the Fermi Gamma Ray Telescope was analyzed and an excess of gamma rays was claimed to be found in the emission spectrum from the Galactic Center Region. Hooper and Goodenough suggest that the claimed excess can be well explained by 7-10 GeV annihilating dark matter with a power law density profile if the dark matter annihilates predominantly to tau pairs. In this paper we present such a dark matter model by extending the MSSM to include four Higgs doublets and one scalar singlet. A Z2 symmetry is imposed that enforces a Yukawa structure so that the up quarks, down quarks, and leptons each receive mass from a distinct doublet. This leads to an enhanced coupling of scalars to leptons and allows the model to naturally achieve the required phenomenology in order to explain the gamma ray excess. Our model yields the correct dark matter thermal relic density and avoids collider bounds from measurements of the Z width as well as direct production at LEP.
hep-ph/9703256
P. G. Tinyakov
A. N. Kuznetsov, P. G. Tinyakov
False Vacuum Decay Induced by Particle Collisions
15 pages, RevTeX, 9 PostScript figures included
Phys.Rev. D56 (1997) 1156-1169
10.1103/PhysRevD.56.1156
INR-TH-97/017
hep-ph
null
The semiclassical formalism for numerical calculation of the rate of tunneling transitions induced by N particles with total energy E of order or higher than the height of the barrier is developed. The formalism is applied to the induced false vacuum decay in the massive four-dimensional $-\lambda\phi^4$ model. The decay rate, as a function of E and N, is calculated numerically in the range $0.4\lsim E/E_{sph}\lsim 3.5$ and $0.25 \lsim N/N_{sph}\lsim 1.0$, where $E_{sph}$ and $N_{sph}$ are the energy and the number of particles in the analog of the sphaleron configuration. The results imply that the ``two-particle'' cross section of the false vacuum decay is exponentially suppressed at least up to energies of order $10 E_{sph}$. At $E\sim E_{sph}$, this exponential suppression is estimated as about 80% of the zero energy suppression.
[ { "created": "Thu, 6 Mar 1997 16:38:52 GMT", "version": "v1" } ]
2009-10-30
[ [ "Kuznetsov", "A. N.", "" ], [ "Tinyakov", "P. G.", "" ] ]
The semiclassical formalism for numerical calculation of the rate of tunneling transitions induced by N particles with total energy E of order or higher than the height of the barrier is developed. The formalism is applied to the induced false vacuum decay in the massive four-dimensional $-\lambda\phi^4$ model. The decay rate, as a function of E and N, is calculated numerically in the range $0.4\lsim E/E_{sph}\lsim 3.5$ and $0.25 \lsim N/N_{sph}\lsim 1.0$, where $E_{sph}$ and $N_{sph}$ are the energy and the number of particles in the analog of the sphaleron configuration. The results imply that the ``two-particle'' cross section of the false vacuum decay is exponentially suppressed at least up to energies of order $10 E_{sph}$. At $E\sim E_{sph}$, this exponential suppression is estimated as about 80% of the zero energy suppression.
0809.1390
Jackson Wu
We-Fu Chang, John N. Ng, Jackson M. S. Wu
Flavour Changing Neutral Current Constraints from Kaluza-Klein Gluons and Quark Mass Matrices in RS1
v2: 23 pages, 1 figure. Typos corrected, references added. Discussions in Sec. III extended with clarifications, Additional appendix added
Phys.Rev.D79:056007,2009
10.1103/PhysRevD.79.056007
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We continue our previous study on what are the allowed forms of quark mass matrices in the Randall-Sundrum (RS) framework that can reproduce the experimentally observed quark mass spectrum and the CKM mixing pattern. We study the constraints the $\Delta F = 2$ processes in the neutral meson sector placed on the admissible forms found there, and we found only the asymmetrical type of quark mass matrices arising from anarchical Yukawa structures stay viable at the few TeV scale reachable at the LHC. We study also the decay of the first Kaluza-Klein (KK) excitation of the gluon. We give the decay branching ratios into quark pairs, and we point out that measurements of the decay width and just one of the quark spins in the dominant $\bar{t}t$ decays can be used to extract the effective coupling of the first KK gluon to top quarks for both chiralities. This provides further probe to the flavour structure of the RS framework.
[ { "created": "Mon, 8 Sep 2008 17:38:41 GMT", "version": "v1" }, { "created": "Sun, 23 Nov 2008 14:42:58 GMT", "version": "v2" } ]
2009-11-13
[ [ "Chang", "We-Fu", "" ], [ "Ng", "John N.", "" ], [ "Wu", "Jackson M. S.", "" ] ]
We continue our previous study on what are the allowed forms of quark mass matrices in the Randall-Sundrum (RS) framework that can reproduce the experimentally observed quark mass spectrum and the CKM mixing pattern. We study the constraints the $\Delta F = 2$ processes in the neutral meson sector placed on the admissible forms found there, and we found only the asymmetrical type of quark mass matrices arising from anarchical Yukawa structures stay viable at the few TeV scale reachable at the LHC. We study also the decay of the first Kaluza-Klein (KK) excitation of the gluon. We give the decay branching ratios into quark pairs, and we point out that measurements of the decay width and just one of the quark spins in the dominant $\bar{t}t$ decays can be used to extract the effective coupling of the first KK gluon to top quarks for both chiralities. This provides further probe to the flavour structure of the RS framework.
1907.04311
Ayan Paul
Jorge de Blas, Gauthier Durieux, Christophe Grojean, Jiayin Gu and Ayan Paul
On the future of Higgs, electroweak and diboson measurements at lepton colliders
49 pages, 13 figures and 8 tables
null
10.1007/JHEP12(2019)117
DESY 19-077, HU-EP-19/33, MITP/19-028
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
LEP precision on electroweak measurements was sufficient not to hamper the extraction of Higgs couplings at the LHC. But the foreseen permille-level Higgs measurements at future lepton colliders might suffer from parametric electroweak uncertainties in the absence of a dedicated electroweak program. We perform a joint, complete and consistent effective-field-theory analysis of Higgs and electroweak processes. The full electroweak-sector dependence of the $e^+e^- \to WW$ production process is notably accounted for, using statistically optimal observables. Up-to-date HL-LHC projections are combined with CEPC, FCC-ee, ILC and CLIC ones. For circular colliders, our results demonstrate the importance of a new $Z$-pole program for the robust extraction of Higgs couplings. At linear colliders, we show how exploiting multiple polarizations and centre-of-mass energies is crucial to mitigate contaminations from electroweak parameter uncertainties on the Higgs physics program. We also investigate the potential of alternative electroweak measurements to compensate for the lack of direct $Z$-pole run, considering for instance radiative return to these energies. Conversely, we find that Higgs measurements at linear colliders could improve our knowledge of the $Z$ couplings to electrons.
[ { "created": "Tue, 9 Jul 2019 17:49:39 GMT", "version": "v1" }, { "created": "Thu, 10 Sep 2020 13:54:32 GMT", "version": "v2" } ]
2020-09-11
[ [ "de Blas", "Jorge", "" ], [ "Durieux", "Gauthier", "" ], [ "Grojean", "Christophe", "" ], [ "Gu", "Jiayin", "" ], [ "Paul", "Ayan", "" ] ]
LEP precision on electroweak measurements was sufficient not to hamper the extraction of Higgs couplings at the LHC. But the foreseen permille-level Higgs measurements at future lepton colliders might suffer from parametric electroweak uncertainties in the absence of a dedicated electroweak program. We perform a joint, complete and consistent effective-field-theory analysis of Higgs and electroweak processes. The full electroweak-sector dependence of the $e^+e^- \to WW$ production process is notably accounted for, using statistically optimal observables. Up-to-date HL-LHC projections are combined with CEPC, FCC-ee, ILC and CLIC ones. For circular colliders, our results demonstrate the importance of a new $Z$-pole program for the robust extraction of Higgs couplings. At linear colliders, we show how exploiting multiple polarizations and centre-of-mass energies is crucial to mitigate contaminations from electroweak parameter uncertainties on the Higgs physics program. We also investigate the potential of alternative electroweak measurements to compensate for the lack of direct $Z$-pole run, considering for instance radiative return to these energies. Conversely, we find that Higgs measurements at linear colliders could improve our knowledge of the $Z$ couplings to electrons.
1310.7439
David A. Kosower
Z. Bern, L. J. Dixon, F. Febres Cordero, S. Hoeche, H. Ita, D. A. Kosower, D. Maitre
Ntuples for NLO Events at Hadron Colliders
43 pages, 6 tables
null
10.1016/j.cpc.2014.01.011
UCLA/13/TEP/108, SLAC--PUB--15739, SB/F/422-13, IPhT--T13/228, IPPP-13-86, CERN--PH--TH/2013-243
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an event-file format for the dissemination of next-to-leading-order (NLO) predictions for QCD processes at hadron colliders. The files contain all information required to compute generic jet-based infrared-safe observables at fixed order (without showering or hadronization), and to recompute observables with different factorization and renormalization scales. The files also make it possible to evaluate cross sections and distributions with different parton distribution functions. This in turn makes it possible to estimate uncertainties in NLO predictions of a wide variety of observables without recomputing the short-distance matrix elements. The event files allow a user to choose among a wide range of commonly-used jet algorithms and jet-size parameters. We provide event files for a $W$ or $Z$ boson accompanied by up to four jets, and for pure-jet events with up to four jets. The files are for the Large Hadron Collider with a center of mass energy of 7 or 8 TeV. A C++ library along with a Python interface for handling these files are also provided and described in this article. The library allows a user to read the event files and recompute observables transparently for different pdf sets and factorization and renormalization scales.
[ { "created": "Mon, 28 Oct 2013 14:54:49 GMT", "version": "v1" } ]
2015-06-17
[ [ "Bern", "Z.", "" ], [ "Dixon", "L. J.", "" ], [ "Cordero", "F. Febres", "" ], [ "Hoeche", "S.", "" ], [ "Ita", "H.", "" ], [ "Kosower", "D. A.", "" ], [ "Maitre", "D.", "" ] ]
We present an event-file format for the dissemination of next-to-leading-order (NLO) predictions for QCD processes at hadron colliders. The files contain all information required to compute generic jet-based infrared-safe observables at fixed order (without showering or hadronization), and to recompute observables with different factorization and renormalization scales. The files also make it possible to evaluate cross sections and distributions with different parton distribution functions. This in turn makes it possible to estimate uncertainties in NLO predictions of a wide variety of observables without recomputing the short-distance matrix elements. The event files allow a user to choose among a wide range of commonly-used jet algorithms and jet-size parameters. We provide event files for a $W$ or $Z$ boson accompanied by up to four jets, and for pure-jet events with up to four jets. The files are for the Large Hadron Collider with a center of mass energy of 7 or 8 TeV. A C++ library along with a Python interface for handling these files are also provided and described in this article. The library allows a user to read the event files and recompute observables transparently for different pdf sets and factorization and renormalization scales.
hep-ph/9708204
Renard Fernand Michel
G.J. Gounaris, J. Layssac, D.T. Papadamou, G. Tsirigoti and F.M. Renard
Tests of possible non standard properties of the heavy quarks and the Higgs boson
11 pages and 2 figures. e-mail: renard@lpmsun2.lpm.univ-montp2.fr
null
null
PM 97/28, THES-TP 97/06
hep-ph
null
We discuss the sensitivity of the processes e+e- to b b(bar), e+e- to t t(bar) and gamma gamma to H to certain residual New Physics interactions affecting the heavy quark and Higgs boson sector. With a linear collider of 500 GeV, one should be able to detect and identify such effects with a characteristic scale up to 50 TeV.
[ { "created": "Fri, 1 Aug 1997 05:54:12 GMT", "version": "v1" } ]
2007-05-23
[ [ "Gounaris", "G. J.", "" ], [ "Layssac", "J.", "" ], [ "Papadamou", "D. T.", "" ], [ "Tsirigoti", "G.", "" ], [ "Renard", "F. M.", "" ] ]
We discuss the sensitivity of the processes e+e- to b b(bar), e+e- to t t(bar) and gamma gamma to H to certain residual New Physics interactions affecting the heavy quark and Higgs boson sector. With a linear collider of 500 GeV, one should be able to detect and identify such effects with a characteristic scale up to 50 TeV.
1603.02462
Konstantin Kouzakov
Konstantin A. Kouzakov and Alexander I. Studenikin
Neutrino-atom collisions
5 pages, submitted to proceedings of TAUP 2015
null
10.1088/1742-6596/718/6/062031
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Neutrino-atom scattering provides a sensitive tool for probing nonstandard interactions of massive neutrinos in laboratory measurements. The ionization channel of this collision process plays an important role in experiments searching for neutrino magnetic moments. We discuss some theoretical aspects of atomic ionization by massive neutrinos. We also outline possible manifestations of neutrino electromagnetic properties in coherent elastic neutrino-nucleus scattering.
[ { "created": "Tue, 8 Mar 2016 10:26:14 GMT", "version": "v1" } ]
2016-06-22
[ [ "Kouzakov", "Konstantin A.", "" ], [ "Studenikin", "Alexander I.", "" ] ]
Neutrino-atom scattering provides a sensitive tool for probing nonstandard interactions of massive neutrinos in laboratory measurements. The ionization channel of this collision process plays an important role in experiments searching for neutrino magnetic moments. We discuss some theoretical aspects of atomic ionization by massive neutrinos. We also outline possible manifestations of neutrino electromagnetic properties in coherent elastic neutrino-nucleus scattering.
1207.1663
Guy D. Moore
Aleksi Kurkela, Guy D. Moore
UV Cascade in Classical Yang-Mills Theory
24 pages with 13 color figures
null
10.1103/PhysRevD.86.056008
INT-PUB-12-032
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the real-time behavior of classical Yang-Mills theory under initial conditions with nonperturbatively large, infrared field amplitudes. Our lattice study confirms the cascade of energy towards higher momenta and lower occupancy, which occurs via a scaling solution $f[p,t_1] = (t_0/t_1)^{4/7}\, f[p (t_0/t_1)^{1/7},t_0]$. Above a characteristic scale p_{max}, f falls exponentially; below p_{max}, $f[p] \propto p^{-4/3}$. We find no evidence for different infrared exponents or for infrared occupancies in excess of those described by this scaling solution. We also investigate what the fate of large occupancies would be, both in the electric and the magnetic sector.
[ { "created": "Fri, 6 Jul 2012 15:32:57 GMT", "version": "v1" } ]
2013-05-30
[ [ "Kurkela", "Aleksi", "" ], [ "Moore", "Guy D.", "" ] ]
We study the real-time behavior of classical Yang-Mills theory under initial conditions with nonperturbatively large, infrared field amplitudes. Our lattice study confirms the cascade of energy towards higher momenta and lower occupancy, which occurs via a scaling solution $f[p,t_1] = (t_0/t_1)^{4/7}\, f[p (t_0/t_1)^{1/7},t_0]$. Above a characteristic scale p_{max}, f falls exponentially; below p_{max}, $f[p] \propto p^{-4/3}$. We find no evidence for different infrared exponents or for infrared occupancies in excess of those described by this scaling solution. We also investigate what the fate of large occupancies would be, both in the electric and the magnetic sector.
1012.5365
Roman Nevzorov
J. P. Hall, S. F. King, R. Nevzorov, S. Pakvasa, M. Sher
Nonstandard Higgs decays in the E(6)SSM
Parallel talk at the XIXth International Workshop on High Energy Physics and Quantum Field Theory, Golitsyno, Moscow, Russia, September 2010, 6 pages
PoS QFTHEP2010:069,2011
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the nonstandard decays of the lightest Higgs state within the Exceptional Supersymmetric Standard Model (E6SSM). We argued that the SM--like Higgs boson can decay predominantly into dark matter particles while its branching ratios into SM particles varies from 2% to 4%. This scenario also implies the presence of other relatively light Inert chargino and neutralino states in the particle spectrum with masses below 200 GeV. We argue that in this case the decays of the lightest Higgs boson into l^{+} l^{-} + X may play an essential role in the Higgs searches.
[ { "created": "Fri, 24 Dec 2010 08:40:31 GMT", "version": "v1" } ]
2011-05-13
[ [ "Hall", "J. P.", "" ], [ "King", "S. F.", "" ], [ "Nevzorov", "R.", "" ], [ "Pakvasa", "S.", "" ], [ "Sher", "M.", "" ] ]
We study the nonstandard decays of the lightest Higgs state within the Exceptional Supersymmetric Standard Model (E6SSM). We argued that the SM--like Higgs boson can decay predominantly into dark matter particles while its branching ratios into SM particles varies from 2% to 4%. This scenario also implies the presence of other relatively light Inert chargino and neutralino states in the particle spectrum with masses below 200 GeV. We argue that in this case the decays of the lightest Higgs boson into l^{+} l^{-} + X may play an essential role in the Higgs searches.
2204.04889
Jongkuk Kim
Seungwon Baek, Jongkuk Kim, P. Ko
Muon $(g-2)$ and Thermal WIMP DM in ${\rm U(1)}_{L_\mu-L_\tau} $ Models
17 pages, 11 figures, references added
null
null
KIAS-P22019
hep-ph
http://creativecommons.org/licenses/by/4.0/
${\rm U(1)}_{L_\mu - L_\tau} \equiv {\rm U(1)}_X$ model is anomaly free within the Standard Model (SM) fermion content, and can accommodate the muon $(g-2)$ data for $M_{Z'} \sim O(10-100)$ MeV and $g_X \sim (4 - 8) \times 10^{-4}$. WIMP type thermal dark matter (DM) can be also introduced for $M_{Z'} \sim 2 M_{\rm DM}$, if DM pair annihilations into the SM particles occur only through the $s$-channel $Z'$ exchange. In this work, we show that this tight correlation between $M_{Z'}$ and $M_{\rm DM}$ can be completely evaded both for scalar and fermionic DM, if we include the contributions from dark Higgs boson ($H_1$). Dark Higgs boson plays a crucial role in DM phenomenology, not only for generation of dark photon mass, but also opening new channels for DM pair annihilations into the final states involving dark Higgs boson, such as dark Higgs pair as well as $Z' Z'$ through dark Higgs exchange in the $s$-channel, and co-annihilation into $Z' H_1$ in case of inelastic DM. Thus dark Higgs boson will dissect the strong correlation $M_{Z'} \sim 2 M_{\rm DM}$, and much wider mass range is allowed for $U(1)_X$-charged complex scalar and Dirac fermion DM, still explaining the muon $(g-2)$. We consider both generic $U(1)_X$ breaking as well as ${\rm U(1)}_X \rightarrow Z_2$ (and also into $Z_3$ only for scalar DM case).
[ { "created": "Mon, 11 Apr 2022 06:17:56 GMT", "version": "v1" }, { "created": "Mon, 16 May 2022 08:41:14 GMT", "version": "v2" } ]
2022-05-17
[ [ "Baek", "Seungwon", "" ], [ "Kim", "Jongkuk", "" ], [ "Ko", "P.", "" ] ]
${\rm U(1)}_{L_\mu - L_\tau} \equiv {\rm U(1)}_X$ model is anomaly free within the Standard Model (SM) fermion content, and can accommodate the muon $(g-2)$ data for $M_{Z'} \sim O(10-100)$ MeV and $g_X \sim (4 - 8) \times 10^{-4}$. WIMP type thermal dark matter (DM) can be also introduced for $M_{Z'} \sim 2 M_{\rm DM}$, if DM pair annihilations into the SM particles occur only through the $s$-channel $Z'$ exchange. In this work, we show that this tight correlation between $M_{Z'}$ and $M_{\rm DM}$ can be completely evaded both for scalar and fermionic DM, if we include the contributions from dark Higgs boson ($H_1$). Dark Higgs boson plays a crucial role in DM phenomenology, not only for generation of dark photon mass, but also opening new channels for DM pair annihilations into the final states involving dark Higgs boson, such as dark Higgs pair as well as $Z' Z'$ through dark Higgs exchange in the $s$-channel, and co-annihilation into $Z' H_1$ in case of inelastic DM. Thus dark Higgs boson will dissect the strong correlation $M_{Z'} \sim 2 M_{\rm DM}$, and much wider mass range is allowed for $U(1)_X$-charged complex scalar and Dirac fermion DM, still explaining the muon $(g-2)$. We consider both generic $U(1)_X$ breaking as well as ${\rm U(1)}_X \rightarrow Z_2$ (and also into $Z_3$ only for scalar DM case).
hep-ph/9908315
Andreas Vogt
Andreas Vogt (Leiden University)
Real photon structure at an e^+e^- linear collider
6 pages LaTeX including 7 eps-figures, uses espcrc2.sty (included). Talk presented at PHOTON'99, Freiburg (Germany), May 1999. To appear in the proceedings [Nucl. Phys. B (Proc. Suppl.)]
Nucl.Phys.Proc.Suppl. 82 (2000) 394-399
10.1016/S0920-5632(00)00184-5
null
hep-ph
null
Previous studies of the kinematic coverage for measuring the photon structure function F_2^gamma at a future 500 GeV e^+e^- linear collider are updated using current estimates of luminosities and important detector parameters. The perturbative expansion for the evolution of F_2^gamma is briefly recalled in view of a recent claim that all existing next-to-leading order analyses of the photon structure are incorrect. A simple illustration is given of the different sensitivities of hadronic and photonic structure functions on the strong coupling constant alpha_s.
[ { "created": "Tue, 10 Aug 1999 10:49:48 GMT", "version": "v1" } ]
2009-10-31
[ [ "Vogt", "Andreas", "", "Leiden University" ] ]
Previous studies of the kinematic coverage for measuring the photon structure function F_2^gamma at a future 500 GeV e^+e^- linear collider are updated using current estimates of luminosities and important detector parameters. The perturbative expansion for the evolution of F_2^gamma is briefly recalled in view of a recent claim that all existing next-to-leading order analyses of the photon structure are incorrect. A simple illustration is given of the different sensitivities of hadronic and photonic structure functions on the strong coupling constant alpha_s.
hep-ph/0111393
Ismd31
Giuseppina Anzivino (the NA48 Collaboration: Cagliari, Cambridge, CERN, Dubna, Edinburgh, Ferrara, Firenze, Mainz, Orsay, Perugia, Pisa, Saclay, Siegen, Torino, Warszawa, Wien.)
Measurement of Direct CP Violation by NA48
8 pages, 6 figures (in eps) talk given at XXXI International Symposium on Multiparticle Dynamics, Sep. 1-7, 2001, Datong China URL http://ismd31.ccnu.edu.cn/
null
10.1142/9789812778048_0002
null
hep-ph
null
The NA48 experiment at the CERN SPS aims to search for direct CP violation in the $K^0$ system through the measurement of ${\rm Re}(\epsilon'/ \epsilon)$ with high accuracy. In 1999 the NA48 collaboration has published its first measuremen based on 1997 data. A new result, based on 1998 and 1999 data, is presented in this article. The result, combined with 1997 data, ${\rm Re}(\epsilon'/\epsilon) = (15.3 \pm 2.6)\times 10^{-4}$, contributes to the precise determination of the size of direct CP violation.
[ { "created": "Thu, 29 Nov 2001 08:27:57 GMT", "version": "v1" } ]
2017-08-23
[ [ "Anzivino", "Giuseppina", "", "the NA48 Collaboration: Cagliari, Cambridge,\n CERN, Dubna, Edinburgh, Ferrara, Firenze, Mainz, Orsay, Perugia, Pisa,\n Saclay, Siegen, Torino, Warszawa, Wien." ] ]
The NA48 experiment at the CERN SPS aims to search for direct CP violation in the $K^0$ system through the measurement of ${\rm Re}(\epsilon'/ \epsilon)$ with high accuracy. In 1999 the NA48 collaboration has published its first measuremen based on 1997 data. A new result, based on 1998 and 1999 data, is presented in this article. The result, combined with 1997 data, ${\rm Re}(\epsilon'/\epsilon) = (15.3 \pm 2.6)\times 10^{-4}$, contributes to the precise determination of the size of direct CP violation.
1208.0035
Kyoungchul Kong
Kyoungchul Kong
TASI 2011: CalcHEP and PYTHIA Tutorials
39 pages, 14 figures
null
10.1142/9789814390163_0004
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This note summarizes a pedagogical tutorial on CalcHEP and PYTHIA that was given at TASI 2011 program.
[ { "created": "Tue, 31 Jul 2012 21:21:49 GMT", "version": "v1" } ]
2017-08-23
[ [ "Kong", "Kyoungchul", "" ] ]
This note summarizes a pedagogical tutorial on CalcHEP and PYTHIA that was given at TASI 2011 program.
1810.11478
Joao Pacheco B. C. de Melo Dr.
J. P. B. C. de Melo (Laborat\'orio de F\'isica Te\'orica e Computacional - LFTC, Universidade Cruzeiro do Sul, Brazil)
Unambiguous Extraction of the Electromagnetic Form Factors for Spin-1 Particles on the Light-Front
Use elsevier style.1 latex file and 10 figures eps. Revised version. To appear Phys. Lett. B. (2018)
null
10.1016/j.physletb.2018.11.003
LFTC-18-12/33
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The electromagnetic form factors of a composite vector particle within the light-front formulation of the Mandelstam formula is investigated. In order to extract the form factors from the matrix elements of the plus component of the current in the Drell-Yan frame, where the momentum transfer is chosen such that $q^+=q^0+q^3=0$, one has in principle the freedom to choose between different linear combinations of matrix elements of the current operator. The different prescriptions to calculate the electromagnetic form factors, $G_0,G_1$ and $G_2$, i.e., charge form factor, magnetic and quadrupole respectively. If the covariance is respected, all prescriptions give the same results, misfortune, is not the situation, the light-front approach produce different results, which depend of the prescriptions as utilized to extract the electromagnetic form factors in the case of the spin-1 particles. The main differences of the prescriptions appear because of the light-front matrix elements of the electromagnetic current are contaminated by the zero-modes contributions to the same with the plus component of the matrix elements of the electromagnetic current. However, the Inna Grach prescription is immune to the zero-modes contributions to the electromagnetic current, then the electromagnetic form factors extracted with that prescriptions do not have zero-modes contribution and give the same result compared with the instant form quantum field theory. Another's prescriptions with the light-front approach are contaminated by the zero-modes contributions to the matrix elements of the electromagnetic current with the plus component of the current.
[ { "created": "Fri, 26 Oct 2018 18:15:08 GMT", "version": "v1" }, { "created": "Thu, 1 Nov 2018 15:12:16 GMT", "version": "v2" } ]
2018-12-26
[ [ "de Melo", "J. P. B. C.", "", "Laboratório de Física Teórica e\n Computacional - LFTC, Universidade Cruzeiro do Sul, Brazil" ] ]
The electromagnetic form factors of a composite vector particle within the light-front formulation of the Mandelstam formula is investigated. In order to extract the form factors from the matrix elements of the plus component of the current in the Drell-Yan frame, where the momentum transfer is chosen such that $q^+=q^0+q^3=0$, one has in principle the freedom to choose between different linear combinations of matrix elements of the current operator. The different prescriptions to calculate the electromagnetic form factors, $G_0,G_1$ and $G_2$, i.e., charge form factor, magnetic and quadrupole respectively. If the covariance is respected, all prescriptions give the same results, misfortune, is not the situation, the light-front approach produce different results, which depend of the prescriptions as utilized to extract the electromagnetic form factors in the case of the spin-1 particles. The main differences of the prescriptions appear because of the light-front matrix elements of the electromagnetic current are contaminated by the zero-modes contributions to the same with the plus component of the matrix elements of the electromagnetic current. However, the Inna Grach prescription is immune to the zero-modes contributions to the electromagnetic current, then the electromagnetic form factors extracted with that prescriptions do not have zero-modes contribution and give the same result compared with the instant form quantum field theory. Another's prescriptions with the light-front approach are contaminated by the zero-modes contributions to the matrix elements of the electromagnetic current with the plus component of the current.
1510.05568
Mikhail Voloshin
M.B. Voloshin
Remarks on measurement of the decay $\Xi_b^- \to \Lambda_b \pi^-$
4 pages
null
null
FTPI-MINN-15/44, UMN-TH-3507/15
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The interpretation of the recent observation by LHCb of a heavy-flavor-conserving and strangeness-changing decay $\Xi_b^- \to \Lambda_b \pi^-$ in terms of the branching fraction for the decay suffers from the uncertainty in the yield of the $\Xi_b^-$ hyperons relative to that of the $\Lambda_b$. It is pointed out here that this relative yield can be determined with a significantly reduced uncertainty by measuring within the same experimental conditions the decays related by the flavor $SU(3)$ symmetry and/or the heavy quark symmetry, such as $\Xi_b \to J/\psi \, \Xi$, $\Lambda_b \to J/\psi \, \Lambda$, or $\Xi_b^- \to \Xi_c^0 \ell \nu$, $\Lambda_b \to \Lambda_c \ell \nu$.
[ { "created": "Mon, 19 Oct 2015 16:27:03 GMT", "version": "v1" }, { "created": "Wed, 21 Oct 2015 17:22:05 GMT", "version": "v2" } ]
2015-10-22
[ [ "Voloshin", "M. B.", "" ] ]
The interpretation of the recent observation by LHCb of a heavy-flavor-conserving and strangeness-changing decay $\Xi_b^- \to \Lambda_b \pi^-$ in terms of the branching fraction for the decay suffers from the uncertainty in the yield of the $\Xi_b^-$ hyperons relative to that of the $\Lambda_b$. It is pointed out here that this relative yield can be determined with a significantly reduced uncertainty by measuring within the same experimental conditions the decays related by the flavor $SU(3)$ symmetry and/or the heavy quark symmetry, such as $\Xi_b \to J/\psi \, \Xi$, $\Lambda_b \to J/\psi \, \Lambda$, or $\Xi_b^- \to \Xi_c^0 \ell \nu$, $\Lambda_b \to \Lambda_c \ell \nu$.
1805.10552
Cherepanov Vladimir
Vladimir Cherepanov, Wolfgang Lohmann
Methods for a measurement of $\tau$ polarization asymmetry in the decay $Z\rightarrow \tau\tau$ at LHC and determination of the effective weak mixing angle
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper a general method to measure the longitudinal polarization of $\tau$ lepton in the process $pp \rightarrow Z^{0} \rightarrow \tau\tau$ is described. The method of optimal observable allows to distinguish between the $\tau$ lepton helicity states with maximum possible sensitivity. The optimal observable for the main $\tau$ decay modes ($e/\mu\nu\nu$, $\pi\nu$, $\rho\nu$, $a_{1}\nu$) that can be identified by CMS or ATLAS detectors is described. The analyzing power for $\tau$ polarization can be further gained by taking into account a correlation between longitudinal spin states of $\tau^{+}$ and $\tau^{-}$. The theoretical systematic uncertainty on the $\tau$ polarization measured using the $\tau \rightarrow 3\pi\nu$ decays is estimated to be $(\Delta P_{\tau})_{model} = (1.41 \pm 1.37)\times 10^{-4}$. This value is approximately 50 times smaller than the best uncertainty on $\tau$ polarization measurement given by combination of all LEP results. An approach to propagate the measured $\tau$ polarization averaged over the $Z^{0}$ lineshape and parton density functions to the electroweak parameters is also discussed.
[ { "created": "Sat, 26 May 2018 23:14:33 GMT", "version": "v1" } ]
2018-05-29
[ [ "Cherepanov", "Vladimir", "" ], [ "Lohmann", "Wolfgang", "" ] ]
In this paper a general method to measure the longitudinal polarization of $\tau$ lepton in the process $pp \rightarrow Z^{0} \rightarrow \tau\tau$ is described. The method of optimal observable allows to distinguish between the $\tau$ lepton helicity states with maximum possible sensitivity. The optimal observable for the main $\tau$ decay modes ($e/\mu\nu\nu$, $\pi\nu$, $\rho\nu$, $a_{1}\nu$) that can be identified by CMS or ATLAS detectors is described. The analyzing power for $\tau$ polarization can be further gained by taking into account a correlation between longitudinal spin states of $\tau^{+}$ and $\tau^{-}$. The theoretical systematic uncertainty on the $\tau$ polarization measured using the $\tau \rightarrow 3\pi\nu$ decays is estimated to be $(\Delta P_{\tau})_{model} = (1.41 \pm 1.37)\times 10^{-4}$. This value is approximately 50 times smaller than the best uncertainty on $\tau$ polarization measurement given by combination of all LEP results. An approach to propagate the measured $\tau$ polarization averaged over the $Z^{0}$ lineshape and parton density functions to the electroweak parameters is also discussed.
hep-ph/9507349
O. W. Greenberg
O.W. Greenberg
Conservation of Statistics and Generalized Grassmann Numbers
10 pages, latex
null
10.1016/0375-9601(95)00845-0
University of Maryland Preprint 96-3
hep-ph hep-th quant-ph
null
Conservation of statistics requires that fermions be coupled to Grassmann external sources. Correspondingly, conservation of statistics requires that parabosons, parafermions and quons be coupled to external sources that are the appropriate generalizations of Grassmann numbers.
[ { "created": "Wed, 19 Jul 1995 19:37:07 GMT", "version": "v1" } ]
2009-10-28
[ [ "Greenberg", "O. W.", "" ] ]
Conservation of statistics requires that fermions be coupled to Grassmann external sources. Correspondingly, conservation of statistics requires that parabosons, parafermions and quons be coupled to external sources that are the appropriate generalizations of Grassmann numbers.
1411.7038
Diego Aristizabal
D. Aristizabal Sierra, A. Degee, L. Dorame, M. Hirsch
Systematic classification of two-loop realizations of the Weinberg operator
Few clarifications and references added. Matches published version in JHEP
JHEP 1503, 040 (2015)
10.1007/JHEP03(2015)040
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We systematically analyze the $d=5$ Weinberg operator at 2-loop order. Using a diagrammatic approach, we identify two different interesting categories of neutrino mass models: (i) Genuine 2-loop models for which both, tree-level and 1-loop contributions, are guaranteed to be absent. And (ii) finite 2-loop diagrams, which correspond to the 1-loop generation of some particular vertex appearing in a given 1-loop neutrino mass model, thus being effectively 2-loop. From the large list of all possible 2-loop diagrams, the vast majority are infinite corrections to lower order neutrino mass models and only a moderately small number of diagrams fall into these two interesting classes. Moreover, all diagrams in class (i) are just variations of three basic diagrams, with examples discussed in the literature before. Similarly, we also show that class (ii) diagrams consists of only variations of these three plus two more basic diagrams. Finally, we show how our results can be consistently and readily used in order to construct two-loop neutrino mass models.
[ { "created": "Tue, 25 Nov 2014 21:00:18 GMT", "version": "v1" }, { "created": "Fri, 19 Dec 2014 11:10:45 GMT", "version": "v2" }, { "created": "Tue, 24 Mar 2015 20:31:03 GMT", "version": "v3" } ]
2015-03-26
[ [ "Sierra", "D. Aristizabal", "" ], [ "Degee", "A.", "" ], [ "Dorame", "L.", "" ], [ "Hirsch", "M.", "" ] ]
We systematically analyze the $d=5$ Weinberg operator at 2-loop order. Using a diagrammatic approach, we identify two different interesting categories of neutrino mass models: (i) Genuine 2-loop models for which both, tree-level and 1-loop contributions, are guaranteed to be absent. And (ii) finite 2-loop diagrams, which correspond to the 1-loop generation of some particular vertex appearing in a given 1-loop neutrino mass model, thus being effectively 2-loop. From the large list of all possible 2-loop diagrams, the vast majority are infinite corrections to lower order neutrino mass models and only a moderately small number of diagrams fall into these two interesting classes. Moreover, all diagrams in class (i) are just variations of three basic diagrams, with examples discussed in the literature before. Similarly, we also show that class (ii) diagrams consists of only variations of these three plus two more basic diagrams. Finally, we show how our results can be consistently and readily used in order to construct two-loop neutrino mass models.
hep-ph/0005210
Bo-Qiang Ma
Bo-Qiang Ma, Ivan Schmidt, Jacques Soffer, and Jian-Jun Yang
The Quark-Antiquark Asymmetry of the Nucleon Sea from $\Lambda$ and $\bar{\Lambda}$ Fragmentation
15 latex pages, 2 figures
Phys.Lett. B488 (2000) 254-260; Phys.Lett. B489 (2000) 293-299
10.1016/S0370-2693(00)00940-0
CPT-2000/P.4004, USM-TH-92
hep-ph hep-ex nucl-th
null
We present a general analysis of the spin transfer for $\Lambda$ and $\bar{\Lambda}$ production in deep-inelastic scattering of polarized charged leptons on the nucleon, and find that the pattern of different behaviors of $\Lambda$ and $\bar{\Lambda}$ production observed by the E665 Collaboration suggests the possibility of quark-antiquark asymmetries either in the quark to $\Lambda$ fragmentation functions and/or in the quark and antiquark distributions of the target proton. We also point out that the strange-antistrange asymmetry of the nucleon sea may produce an observable contribution to the different behaviors of $\Lambda$ and $\bar{\Lambda}$ production. We find that a softer $\bar{s}(x)$ than $s(x)$ as predicted by the light-cone baryon-meson fluctuation model of intrinsic quark-antiquark pairs of the nucleon sea might lead to a reasonable picture. However, the magnitude is still too small to explain the E665 data and the conclusion has also strong model-dependence. This may suggest the importance of quark-antiquark asymmetry in the quark to $\Lambda$ fragmentation functions, provided that the E665 data are confirmed.
[ { "created": "Mon, 22 May 2000 03:16:36 GMT", "version": "v1" } ]
2009-10-31
[ [ "Ma", "Bo-Qiang", "" ], [ "Schmidt", "Ivan", "" ], [ "Soffer", "Jacques", "" ], [ "Yang", "Jian-Jun", "" ] ]
We present a general analysis of the spin transfer for $\Lambda$ and $\bar{\Lambda}$ production in deep-inelastic scattering of polarized charged leptons on the nucleon, and find that the pattern of different behaviors of $\Lambda$ and $\bar{\Lambda}$ production observed by the E665 Collaboration suggests the possibility of quark-antiquark asymmetries either in the quark to $\Lambda$ fragmentation functions and/or in the quark and antiquark distributions of the target proton. We also point out that the strange-antistrange asymmetry of the nucleon sea may produce an observable contribution to the different behaviors of $\Lambda$ and $\bar{\Lambda}$ production. We find that a softer $\bar{s}(x)$ than $s(x)$ as predicted by the light-cone baryon-meson fluctuation model of intrinsic quark-antiquark pairs of the nucleon sea might lead to a reasonable picture. However, the magnitude is still too small to explain the E665 data and the conclusion has also strong model-dependence. This may suggest the importance of quark-antiquark asymmetry in the quark to $\Lambda$ fragmentation functions, provided that the E665 data are confirmed.
0910.4019
Peter Kroll
P. Kroll (Wuppertal Univ.)
Spin effects in hard exclusive electroproduction of mesons
11 pages, 12 figures, using Latex, talk presented at the conference in honor of Prof. A. Efremov's 75th birthday held at Trento, July, 2009
Mod.Phys.Lett.A24:2893-2902,2009
10.1142/S0217732309001108
WU B 09-11
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this talk various spin effects in hard exclusive electroproduction of mesons are briefly reviewed. The data are discussed in the light of recent theoretical calculations within the frame work of the handbag approach.
[ { "created": "Wed, 21 Oct 2009 08:38:03 GMT", "version": "v1" } ]
2010-02-19
[ [ "Kroll", "P.", "", "Wuppertal Univ." ] ]
In this talk various spin effects in hard exclusive electroproduction of mesons are briefly reviewed. The data are discussed in the light of recent theoretical calculations within the frame work of the handbag approach.
2102.02825
Martin Hoferichter
Andreas Crivellin, Martin Hoferichter, Claudio Andrea Manzari
The Fermi constant from muon decay versus electroweak fits and CKM unitarity
7 pages, 2 figures; journal version
Phys. Rev. Lett. 127, 071801 (2021)
10.1103/PhysRevLett.127.071801
CERN-TH-2021-017, PSI-PR-21-02, ZU-TH 04/21
hep-ph hep-ex hep-lat nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Fermi constant ($G_F$) is extremely well measured through the muon lifetime, defining one of the key fundamental parameters in the Standard Model (SM). Therefore, to search for physics beyond the SM (BSM) via $G_F$, the constraining power is determined by the precision of the second-best independent determination of $G_F$. The best alternative extractions of $G_F$ proceed either via the global electroweak (EW) fit or from superallowed $\beta$ decays in combination with the Cabibbo angle measured in kaon, $\tau$, or $D$ decays. Both variants display some tension with $G_F$ from muon decay, albeit in opposite directions, reflecting the known tensions within the EW fit and hints for the apparent violation of CKM unitarity, respectively. We investigate how BSM physics could bring the three determinations of $G_F$ into agreement using SM effective field theory and comment on future perspectives.
[ { "created": "Thu, 4 Feb 2021 19:00:01 GMT", "version": "v1" }, { "created": "Tue, 10 Aug 2021 15:35:04 GMT", "version": "v2" } ]
2021-08-11
[ [ "Crivellin", "Andreas", "" ], [ "Hoferichter", "Martin", "" ], [ "Manzari", "Claudio Andrea", "" ] ]
The Fermi constant ($G_F$) is extremely well measured through the muon lifetime, defining one of the key fundamental parameters in the Standard Model (SM). Therefore, to search for physics beyond the SM (BSM) via $G_F$, the constraining power is determined by the precision of the second-best independent determination of $G_F$. The best alternative extractions of $G_F$ proceed either via the global electroweak (EW) fit or from superallowed $\beta$ decays in combination with the Cabibbo angle measured in kaon, $\tau$, or $D$ decays. Both variants display some tension with $G_F$ from muon decay, albeit in opposite directions, reflecting the known tensions within the EW fit and hints for the apparent violation of CKM unitarity, respectively. We investigate how BSM physics could bring the three determinations of $G_F$ into agreement using SM effective field theory and comment on future perspectives.
hep-ph/0006050
Aaron K. Grant
Howard Georgi and Aaron K. Grant
A Topcolor Jungle Gym
23 pages, LaTeX, uses epsf and psfig
Phys.Rev.D63:015001,2001
10.1103/PhysRevD.63.015001
HUTP-00/A004
hep-ph
null
We discuss an alternative to the topcolor seesaw mechanism. In our scheme, all the light quarks carry topcolor, and there are many composite SU(2) doublets. This makes it possible to get the observed top quark mass and observed $SU(2) \times U(1)$ breaking in a way that is quite different from the classic seesaw mechanism. We discuss a model of this kind that arises naturally in the context of dynamically broken topcolor. There are many composite scalars in a theory of this kind. This has important effects on the Pagels-Stokar relation and the Higgs mass. We find $m_{\rm Higgs} < 330$ GeV, lighter than in typical topcolor models. We also show that the electroweak singlet quarks in such a model can be lighter than the corresponding quarks in a seesaw model.
[ { "created": "Mon, 5 Jun 2000 21:00:06 GMT", "version": "v1" } ]
2009-09-11
[ [ "Georgi", "Howard", "" ], [ "Grant", "Aaron K.", "" ] ]
We discuss an alternative to the topcolor seesaw mechanism. In our scheme, all the light quarks carry topcolor, and there are many composite SU(2) doublets. This makes it possible to get the observed top quark mass and observed $SU(2) \times U(1)$ breaking in a way that is quite different from the classic seesaw mechanism. We discuss a model of this kind that arises naturally in the context of dynamically broken topcolor. There are many composite scalars in a theory of this kind. This has important effects on the Pagels-Stokar relation and the Higgs mass. We find $m_{\rm Higgs} < 330$ GeV, lighter than in typical topcolor models. We also show that the electroweak singlet quarks in such a model can be lighter than the corresponding quarks in a seesaw model.
hep-ph/9708391
Jose F. Nieves
Juan Carlos D'Olivo and Jose F. Nieves
Nucleon contribution to the neutrino electromagnetic vertex in matter
LaTeX, 18 pages; to appear in PRD
Phys.Rev. D56 (1997) 5898-5906
10.1103/PhysRevD.56.5898
null
hep-ph
null
We calculate the nucleon contribution to the electromagnetic vertex of a neutrino in a background of particles, including the effect of the anomalous magnetic moment of the nucleons. Explicit formulas for the form factors are given in various physical limits of practical interest. Several applications of the results are mentioned, including the effect of an external magnetic field on the dispersion relation of a neutrino in matter.
[ { "created": "Mon, 18 Aug 1997 14:47:09 GMT", "version": "v1" } ]
2009-10-30
[ [ "D'Olivo", "Juan Carlos", "" ], [ "Nieves", "Jose F.", "" ] ]
We calculate the nucleon contribution to the electromagnetic vertex of a neutrino in a background of particles, including the effect of the anomalous magnetic moment of the nucleons. Explicit formulas for the form factors are given in various physical limits of practical interest. Several applications of the results are mentioned, including the effect of an external magnetic field on the dispersion relation of a neutrino in matter.
hep-ph/0512259
Alessandro Papa
R. Fiore, L.L. Jenkovszky, A.V. Kotikov, F. Paccanoni, A. Papa
Asymptotic neutrino-nucleon cross section and saturation effects
19 pages, 2 figures
Phys.Rev. D73 (2006) 053012
10.1103/PhysRevD.73.053012
null
hep-ph
null
In this paper we present a simple analytic expression for the (spin-averaged) neutrino-nucleon cross section for ultra-high energies at twist-2, obtained as the asymptotic limit of our previous findings. This expression gives values for the cross section in remarkable numerical agreement with the previous numerical evaluation in the energy region relevant for forthcoming neutrino experiments. Moreover, we discuss the role and the relevance of saturation and recombination effects in our approach, in comparison with other recent suggestions.
[ { "created": "Tue, 20 Dec 2005 18:33:31 GMT", "version": "v1" } ]
2009-11-11
[ [ "Fiore", "R.", "" ], [ "Jenkovszky", "L. L.", "" ], [ "Kotikov", "A. V.", "" ], [ "Paccanoni", "F.", "" ], [ "Papa", "A.", "" ] ]
In this paper we present a simple analytic expression for the (spin-averaged) neutrino-nucleon cross section for ultra-high energies at twist-2, obtained as the asymptotic limit of our previous findings. This expression gives values for the cross section in remarkable numerical agreement with the previous numerical evaluation in the energy region relevant for forthcoming neutrino experiments. Moreover, we discuss the role and the relevance of saturation and recombination effects in our approach, in comparison with other recent suggestions.
1612.02548
Hanzhong Zhang
Zhan Gao, Ao Luo, Guo-Liang Ma, Guang-You Qin, Han-Zhong Zhang
Overall momentum balance and redistribution of the lost energy in asymmetric dijet events in 2.76~ATeV Pb-Pb collisions with a multi-phase transport model
11 pages, 7 figures
Phys. Rev. C 97, 044903 (2018)
10.1103/PhysRevC.97.044903
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The overall transverse momentum balance and the redistribution of the lost energy from hard jets for asymmetric dijet events in PbPb collisions at 2.76~ATeV at the LHC is studied within A Multi-Phase Transport (AMPT) model. A detailed analysis is performed for the projected transverse momentum $\langle \slashed{p}_{T}^{||} \rangle$ contributed from the final charged hadrons carrying different transverse momenta and emitted from different angular directions. We find that the transverse momentum projection $\langle \slashed{p}_{T}^{||} \rangle $ in the leading jet direction is mainly contributed by hard hadrons ($p_T > 8.0$~GeV/$c$) in both peripheral and central PbPb collisions, while the opposite direction in central collisions is dominated by soft hadrons ($p_T = 0.5$-$2.0$~GeV/$c$). The study of in-cone and out-of-cone contributions to $\langle \slashed{p}_{T}^{||} \rangle$ shows that these soft hadrons are mostly emitted at large angles away from the dijet axis. Our AMPT calculation is in qualitative agreement with the CMS measurements and the primary mechanism for the energy transported to large angles in the AMPT model is the elastic scattering at the partonic stage. Future studies including also inelastic processes should be helpful in understanding the overestimation of the magnitudes of in-cone and out-of-cone imbalances from our AMPT calculations, and shed light on different roles played by radiative and collisional processes in the redistribution of the lost energy from hard jets.
[ { "created": "Thu, 8 Dec 2016 07:10:13 GMT", "version": "v1" }, { "created": "Thu, 22 Dec 2016 11:32:47 GMT", "version": "v2" }, { "created": "Fri, 20 Apr 2018 02:32:43 GMT", "version": "v3" } ]
2018-04-23
[ [ "Gao", "Zhan", "" ], [ "Luo", "Ao", "" ], [ "Ma", "Guo-Liang", "" ], [ "Qin", "Guang-You", "" ], [ "Zhang", "Han-Zhong", "" ] ]
The overall transverse momentum balance and the redistribution of the lost energy from hard jets for asymmetric dijet events in PbPb collisions at 2.76~ATeV at the LHC is studied within A Multi-Phase Transport (AMPT) model. A detailed analysis is performed for the projected transverse momentum $\langle \slashed{p}_{T}^{||} \rangle$ contributed from the final charged hadrons carrying different transverse momenta and emitted from different angular directions. We find that the transverse momentum projection $\langle \slashed{p}_{T}^{||} \rangle $ in the leading jet direction is mainly contributed by hard hadrons ($p_T > 8.0$~GeV/$c$) in both peripheral and central PbPb collisions, while the opposite direction in central collisions is dominated by soft hadrons ($p_T = 0.5$-$2.0$~GeV/$c$). The study of in-cone and out-of-cone contributions to $\langle \slashed{p}_{T}^{||} \rangle$ shows that these soft hadrons are mostly emitted at large angles away from the dijet axis. Our AMPT calculation is in qualitative agreement with the CMS measurements and the primary mechanism for the energy transported to large angles in the AMPT model is the elastic scattering at the partonic stage. Future studies including also inelastic processes should be helpful in understanding the overestimation of the magnitudes of in-cone and out-of-cone imbalances from our AMPT calculations, and shed light on different roles played by radiative and collisional processes in the redistribution of the lost energy from hard jets.
1005.3113
Johannes Bluemlein
Johannes Bl\"umlein and Helmut B\"ottcher
QCD Analysis of Polarized Deep Inelastic Scattering Data
33 pages, 1 style file, 7 figures
Nucl.Phys.B841:205-230,2010
10.1016/j.nuclphysb.2010.08.005
DESY 09-131, SFB-CPP/10-032
hep-ph hep-ex hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A QCD analysis of the world data on polarized deep inelastic scattering is presented in next--to--leading order, including the heavy flavor Wilson coefficient in leading order in the fixed flavor number scheme. New parameterizations are derived for the quark and gluon distributions and the value of $\alpha_s(M_z^2)$ is determined. The impact of the variation of both the renormalization and factorization scales on the distributions and the value of $\alpha_s$ is studied. We obtain $\alpha_s^{\rm NLO}(M_Z^2) = 0.1132~~\begin{array}{l} + 0.0056 \\ -0.0095 \end{array}$. The first moments of the polarized twist--2 parton distribution functions are calculated with correlated errors to allow for comparisons with results from lattice QCD simulations. Potential higher twist contributions to the structure function $g_1(x,Q^2)$ are determined and found to be compatible with zero both for proton and deuteron targets.
[ { "created": "Tue, 18 May 2010 07:26:15 GMT", "version": "v1" }, { "created": "Mon, 9 Aug 2010 18:54:52 GMT", "version": "v2" } ]
2014-11-21
[ [ "Blümlein", "Johannes", "" ], [ "Böttcher", "Helmut", "" ] ]
A QCD analysis of the world data on polarized deep inelastic scattering is presented in next--to--leading order, including the heavy flavor Wilson coefficient in leading order in the fixed flavor number scheme. New parameterizations are derived for the quark and gluon distributions and the value of $\alpha_s(M_z^2)$ is determined. The impact of the variation of both the renormalization and factorization scales on the distributions and the value of $\alpha_s$ is studied. We obtain $\alpha_s^{\rm NLO}(M_Z^2) = 0.1132~~\begin{array}{l} + 0.0056 \\ -0.0095 \end{array}$. The first moments of the polarized twist--2 parton distribution functions are calculated with correlated errors to allow for comparisons with results from lattice QCD simulations. Potential higher twist contributions to the structure function $g_1(x,Q^2)$ are determined and found to be compatible with zero both for proton and deuteron targets.
0804.4826
Konstantin Klimenko
D. Ebert, K.G. Klimenko, A.V. Tyukov, V.Ch. Zhukovsky
Finite size effects in the Gross-Neveu model with isospin chemical potential
12 pages, 8 figures; one reference added; accepted for publication in PRD
Phys.Rev.D78:045008,2008
10.1103/PhysRevD.78.045008
HU-EP-08/14
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The properties of the two-flavored Gross-Neveu model in the (1+1)-dimensional $R^1\times S^1$ spacetime with compactified space coordinate are investigated in the presence of the isospin chemical potential $\mu_I$. The consideration is performed in the limit $N_c\to\infty$, i.e. in the case with infinite number of colored quarks. It is shown that at $L=\infty$ ($L$ is the length of the circumference $S^1$) the pion condensation phase is realized for arbitrary small nonzero $\mu_I$. At finite values of $L$, the phase portraits of the model in terms of parameters $\nu\sim\mu_I$ and $\lambda\sim 1/L$ are obtained both for periodic and antiperiodic boundary conditions of the quark field. It turns out that in the plane $(\lambda,\nu)$ there is a strip $0\le\lambda<\lambda_c$ which lies as a whole inside the pion condensed phase. In this phase the pion condensation gap is an oscillating function vs both $\lambda$ (at fixed $\nu$) and $\nu$ (at fixed $\lambda$).
[ { "created": "Wed, 30 Apr 2008 13:53:43 GMT", "version": "v1" }, { "created": "Wed, 13 Aug 2008 07:31:43 GMT", "version": "v2" } ]
2010-05-12
[ [ "Ebert", "D.", "" ], [ "Klimenko", "K. G.", "" ], [ "Tyukov", "A. V.", "" ], [ "Zhukovsky", "V. Ch.", "" ] ]
The properties of the two-flavored Gross-Neveu model in the (1+1)-dimensional $R^1\times S^1$ spacetime with compactified space coordinate are investigated in the presence of the isospin chemical potential $\mu_I$. The consideration is performed in the limit $N_c\to\infty$, i.e. in the case with infinite number of colored quarks. It is shown that at $L=\infty$ ($L$ is the length of the circumference $S^1$) the pion condensation phase is realized for arbitrary small nonzero $\mu_I$. At finite values of $L$, the phase portraits of the model in terms of parameters $\nu\sim\mu_I$ and $\lambda\sim 1/L$ are obtained both for periodic and antiperiodic boundary conditions of the quark field. It turns out that in the plane $(\lambda,\nu)$ there is a strip $0\le\lambda<\lambda_c$ which lies as a whole inside the pion condensed phase. In this phase the pion condensation gap is an oscillating function vs both $\lambda$ (at fixed $\nu$) and $\nu$ (at fixed $\lambda$).
hep-ph/0410221
Yoshiko Kanada-En'yo
Y. Kanada-En'yo, O. Morimatsu and T. Nishikawa
Narrow Pentaquark States in a Quark Model with Antisymmetrized Molecular Dynamics
Talk given at International Workshop on PENTAQUARK04, Spring-8, Hyogo, Japan, 20-23 Jul 2004
null
10.1142/9789812701855_0035
null
hep-ph
null
The exotic baryon $\Theta^+(uudd\bar{s})$ is studied with microscopic calculations in a quark model by using a method of antisymmetrized molecular dynamics(AMD). We predict narrow states, $J^\pi=1/2^+(I=0)$, $J^\pi=3/2^+(I=0)$, and $J^\pi=3/2^-(I=1)$, which nearly degenerate in a low-energy region of the $uudd\bar{s}$ system. We discuss $NK$ decay widths and estimate them to be $\Gamma< 7$ for the $J^\pi=\{1/2^+,3/2^+\}$, and $\Gamma<1$ MeV for the $J^\pi=3/2^-$ state.
[ { "created": "Fri, 15 Oct 2004 07:16:59 GMT", "version": "v1" } ]
2017-08-23
[ [ "Kanada-En'yo", "Y.", "" ], [ "Morimatsu", "O.", "" ], [ "Nishikawa", "T.", "" ] ]
The exotic baryon $\Theta^+(uudd\bar{s})$ is studied with microscopic calculations in a quark model by using a method of antisymmetrized molecular dynamics(AMD). We predict narrow states, $J^\pi=1/2^+(I=0)$, $J^\pi=3/2^+(I=0)$, and $J^\pi=3/2^-(I=1)$, which nearly degenerate in a low-energy region of the $uudd\bar{s}$ system. We discuss $NK$ decay widths and estimate them to be $\Gamma< 7$ for the $J^\pi=\{1/2^+,3/2^+\}$, and $\Gamma<1$ MeV for the $J^\pi=3/2^-$ state.
1506.03445
Bryan Ostdiek
Bryan Ostdiek
Constraining the minimal dark matter fiveplet with LHC searches
8 pages, 4 figures
Phys. Rev. D 92, 055008 (2015)
10.1103/PhysRevD.92.055008
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Adding a fermion to the standard model particle content which is a fiveplet under $SU(2)_L$ gives a dark matter candidate. The lightest state in the multiplet is neutral and automatically stable. The charged component of the multiplet is only slightly heavier and can travel a finite distance in the LHC detectors before decaying, leaving a charged track which disappears before the edge of the detector. We use the recent ATLAS and CMS searches to exclude a Majorana fiveplet with a mass up to 267 GeV. We estimate that with 3 ab$^{-1}$ of $\sqrt{s}=14$ TeV data this could be pushed to a mass 520 GeV. These exclusions are $\sim 10\%$ greater than what is achieved for wino-like dark matter. We also discuss how the doubly charged states could be used to distinguish a disappearing track signal from that given by a triplet such as the pure wino.
[ { "created": "Wed, 10 Jun 2015 20:00:15 GMT", "version": "v1" } ]
2015-09-16
[ [ "Ostdiek", "Bryan", "" ] ]
Adding a fermion to the standard model particle content which is a fiveplet under $SU(2)_L$ gives a dark matter candidate. The lightest state in the multiplet is neutral and automatically stable. The charged component of the multiplet is only slightly heavier and can travel a finite distance in the LHC detectors before decaying, leaving a charged track which disappears before the edge of the detector. We use the recent ATLAS and CMS searches to exclude a Majorana fiveplet with a mass up to 267 GeV. We estimate that with 3 ab$^{-1}$ of $\sqrt{s}=14$ TeV data this could be pushed to a mass 520 GeV. These exclusions are $\sim 10\%$ greater than what is achieved for wino-like dark matter. We also discuss how the doubly charged states could be used to distinguish a disappearing track signal from that given by a triplet such as the pure wino.
0904.2855
Wei Liao
Wei Liao
Emission angle distribution and flavor transformation of supernova neutrinos
12 pages, 6 figures; section 4 revised
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Using moment equations we analyze collective flavor transformation of supernova neutrinos. We study the convergence of moment equations and find that numerical results using a few moment converge quite fast. We study effects of emission angle distribution of neutrinos on neutrino sphere. We study scaling law of the amplitude of neutrino self-interaction Hamiltonian and find that it depends on model of emission angle distribution of neutrinos. Dependence of neutrino oscillation on different models of emission angle distribution is studied.
[ { "created": "Sun, 19 Apr 2009 03:52:55 GMT", "version": "v1" }, { "created": "Sun, 28 Jun 2009 14:58:48 GMT", "version": "v2" } ]
2009-06-29
[ [ "Liao", "Wei", "" ] ]
Using moment equations we analyze collective flavor transformation of supernova neutrinos. We study the convergence of moment equations and find that numerical results using a few moment converge quite fast. We study effects of emission angle distribution of neutrinos on neutrino sphere. We study scaling law of the amplitude of neutrino self-interaction Hamiltonian and find that it depends on model of emission angle distribution of neutrinos. Dependence of neutrino oscillation on different models of emission angle distribution is studied.
2108.11927
Noah Steinberg
Noah Steinberg
Discovering Axion-Like Particles with Photon Fusion at the ILC
11 pages, 6 figures
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
Experimental searches for Axion-Like Particles (ALPs) which couple to the electroweak bosons span over a wide range of ALP masses, from MeV searches at beam-dump experiments, to TeV searches at the LHC. Here we examine an interesting range of parameter space in which the ALP couples only to hypercharge. In the GeV to hundreds of GeV mass range, the contribution of an ALP to light by light scattering can be significant. By making simple kinematic cuts, we show that the ILC running at $\sqrt{s} = 250\,\rm{GeV}$ or $\sqrt{s} = 500\,\rm{GeV}$ can discover ALPs in this range of masses with significantly smaller couplings to the SM than previous experiments, down to $g_{aBB} = 10^{-3}\,\rm{TeV}^{-1}$.
[ { "created": "Thu, 26 Aug 2021 17:32:08 GMT", "version": "v1" } ]
2021-08-27
[ [ "Steinberg", "Noah", "" ] ]
Experimental searches for Axion-Like Particles (ALPs) which couple to the electroweak bosons span over a wide range of ALP masses, from MeV searches at beam-dump experiments, to TeV searches at the LHC. Here we examine an interesting range of parameter space in which the ALP couples only to hypercharge. In the GeV to hundreds of GeV mass range, the contribution of an ALP to light by light scattering can be significant. By making simple kinematic cuts, we show that the ILC running at $\sqrt{s} = 250\,\rm{GeV}$ or $\sqrt{s} = 500\,\rm{GeV}$ can discover ALPs in this range of masses with significantly smaller couplings to the SM than previous experiments, down to $g_{aBB} = 10^{-3}\,\rm{TeV}^{-1}$.
hep-ph/9705211
null
C. Becchi
Introduction to Gauge Theories
28 pages, LateX, Lectures given at the Triangle Graduate School 96, Charles University, Prague September 2-11, 1996
null
null
CNUM C96/09/02.13
hep-ph
null
These lectures present an elementary introduction to quantum gauge fields. The first aim is to show how, in the tree approximation, gauge invariance follows from covariance and unitarity. This leads to the standard construction of the Lagrangian by means of covariant derivatives in a form that unifies the massive and the massless case. Having so identified the classical theory, the Faddeev-Popov quantization method is introduced and the BRS invariance of the resulting action is discussed.
[ { "created": "Fri, 2 May 1997 08:29:17 GMT", "version": "v1" } ]
2007-05-23
[ [ "Becchi", "C.", "" ] ]
These lectures present an elementary introduction to quantum gauge fields. The first aim is to show how, in the tree approximation, gauge invariance follows from covariance and unitarity. This leads to the standard construction of the Lagrangian by means of covariant derivatives in a form that unifies the massive and the massless case. Having so identified the classical theory, the Faddeev-Popov quantization method is introduced and the BRS invariance of the resulting action is discussed.
hep-ph/0304270
Beata Ziaja
B. Ziaja
Analysis of the polarized deep inelastic scattering at low x including the resummation of the $\ln^2(1/x)$ corrections
Habilitation thesis (in Polish); 23 pages, latex, 1 figure
null
null
null
hep-ph
null
In this thesis we consider the polarized deep inelastic scattering in the region of low values of Bjorken variable, $x$. We formulate the evolution equations for the unintegrated parton distributions which include a complete resummation of the double logarithmic contributions, $\ln^2(1/x)$. Afterwards, these equations are completed with the standard LO and NLO DGLAP evolution terms, in order to obtain the proper behaviour of the parton distributions at moderate and large values of $x$. The equations obtained are applied to the following observables and processes: (i) to the nucleon structure function, $g_1$, in the polarized deep inelastic scattering, (ii) to the structure function of the polarized photon, $g_1^{\gamma}$, in the scattering of a lepton on a polarized photon, and (iii) to the differential structure function, $x_J d^2g_1/dx_J dk_J^2$, in the polarized deep inelastic scattering accompanied by a forward jet. Case (iii) is proposed to be a test process for the presence and the magnitude of the $\ln^2(1/x)$ contributions. For each process the consequences of including the logarithmic corrections are studied in a detail. After integrating out the structure function, $g_1$, the moments of the nucleon structure function are obtained. The contribution of the region of low $x$ to these moments is estimated, and then discussed in the context of the spin sum rules. Finally, some predictions for the observables, the asymmetry and the cross sections, in the processes (i)-(iii) are given. They are important to planned experiments with the polarized HERA and linear colliders, which will probe the region of low values of Bjorken $x$.
[ { "created": "Tue, 29 Apr 2003 11:56:49 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ziaja", "B.", "" ] ]
In this thesis we consider the polarized deep inelastic scattering in the region of low values of Bjorken variable, $x$. We formulate the evolution equations for the unintegrated parton distributions which include a complete resummation of the double logarithmic contributions, $\ln^2(1/x)$. Afterwards, these equations are completed with the standard LO and NLO DGLAP evolution terms, in order to obtain the proper behaviour of the parton distributions at moderate and large values of $x$. The equations obtained are applied to the following observables and processes: (i) to the nucleon structure function, $g_1$, in the polarized deep inelastic scattering, (ii) to the structure function of the polarized photon, $g_1^{\gamma}$, in the scattering of a lepton on a polarized photon, and (iii) to the differential structure function, $x_J d^2g_1/dx_J dk_J^2$, in the polarized deep inelastic scattering accompanied by a forward jet. Case (iii) is proposed to be a test process for the presence and the magnitude of the $\ln^2(1/x)$ contributions. For each process the consequences of including the logarithmic corrections are studied in a detail. After integrating out the structure function, $g_1$, the moments of the nucleon structure function are obtained. The contribution of the region of low $x$ to these moments is estimated, and then discussed in the context of the spin sum rules. Finally, some predictions for the observables, the asymmetry and the cross sections, in the processes (i)-(iii) are given. They are important to planned experiments with the polarized HERA and linear colliders, which will probe the region of low values of Bjorken $x$.
1706.09408
Giovanni Marco Pruna Dr
Giovanni Marco Pruna
The Standard Model and low-energy experiments: from lepton-flavour violation to dark photons
5 pages, IFAE2017 Conference
IL NUOVO CIMENTO C, YEAR 2018 - ISSUE 1-2 - JANUARY-APRIL
10.1393/ncc/i2018-18051-6
IFAE2017-PRUNA, PSI-PR-17-12
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This note is a concise theoretical summary of the first session on new physics searches at the high-intensity frontier of the IFAE2017 Conference. Recent theoretical developments related to muonic lepton-flavour violation and $g-2$ are reviewed.
[ { "created": "Wed, 28 Jun 2017 12:40:43 GMT", "version": "v1" } ]
2018-10-23
[ [ "Pruna", "Giovanni Marco", "" ] ]
This note is a concise theoretical summary of the first session on new physics searches at the high-intensity frontier of the IFAE2017 Conference. Recent theoretical developments related to muonic lepton-flavour violation and $g-2$ are reviewed.
1212.0947
Mirzayusuf Musakhanov
Mirzayusuf Musakhanov
QCD in Infrared Region and Spontaneous Breaking of the Chiral Symmetry
Invited talk given at XXI International Baldin Seminar on High Energy Physics Problems,September 10-15, 2012, JINR, Dubna, Russia. In v2, v3 new references were added together with minor changes of the text
null
null
null
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The spontaneous breaking of chiral symmetry (SBCS) is one of the most important phenomena of hadron physics. It defines the properties of all the light mesons and baryons. The Chiral Perturbation Theory (ChPT) encodes QCD hadronic correlators at low-energy region in the terms the low-energy constants (LEC) -- the expansion parameters on light quark current masses $m$ and external momenta $p$. The LEC's can be extracted from the phenomenology or from QCD lattice calculations. On the other hand, QCD instanton vacuum/instanton liquid model provides a very natural nonperturbative explanation of the SBCS. It provides a consistent framework for description of the pions and thus may be used for evaluation of the LEC. Our aim is to calculate the vacuum properties and the LEC's within instanton vacuum model and confront with phenomenology and lattice results.
[ { "created": "Wed, 5 Dec 2012 07:15:22 GMT", "version": "v1" }, { "created": "Mon, 10 Dec 2012 17:42:53 GMT", "version": "v2" }, { "created": "Tue, 18 Dec 2012 08:58:21 GMT", "version": "v3" } ]
2012-12-19
[ [ "Musakhanov", "Mirzayusuf", "" ] ]
The spontaneous breaking of chiral symmetry (SBCS) is one of the most important phenomena of hadron physics. It defines the properties of all the light mesons and baryons. The Chiral Perturbation Theory (ChPT) encodes QCD hadronic correlators at low-energy region in the terms the low-energy constants (LEC) -- the expansion parameters on light quark current masses $m$ and external momenta $p$. The LEC's can be extracted from the phenomenology or from QCD lattice calculations. On the other hand, QCD instanton vacuum/instanton liquid model provides a very natural nonperturbative explanation of the SBCS. It provides a consistent framework for description of the pions and thus may be used for evaluation of the LEC. Our aim is to calculate the vacuum properties and the LEC's within instanton vacuum model and confront with phenomenology and lattice results.
hep-ph/0404099
Chong Sheng Li
Jian Jun Liu, Chong Sheng Li, Li Lin Yang and Li Gang Jin
Single top quark production via SUSY-QCD FCNC couplings at the CERN LHC in the unconstrained MSSM
39 pages, 10 figures. Published version. Constraints on the mixing parameters updated, references added, minor changes in presentations, results and conclusions unchanged
Nucl.Phys.B705:3-32,2005
10.1016/j.nuclphysb.2004.10.048
null
hep-ph
null
We evaluate the $t\bar{c}$ and $t\bar{u}$ productions at the LHC within the general unconstrained MSSM framework. We find that these single top quark productions induced by SUSY-QCD FCNC couplings have remarkable cross sections for favorable parameter values allowed by current low energy data, which can be as large as a few pb. Once large rates of the $t\bar{c}$ and $t\bar{u}$ productions are detected at the LHC, they may be induced by SUSY FCNC couplings. We show that the precise measurement of single top quark production cross sections at the LHC is a powerful probe for the details of the SUSY FCNC couplings.
[ { "created": "Sun, 11 Apr 2004 01:01:54 GMT", "version": "v1" }, { "created": "Mon, 13 Dec 2004 14:06:59 GMT", "version": "v2" } ]
2008-11-26
[ [ "Liu", "Jian Jun", "" ], [ "Li", "Chong Sheng", "" ], [ "Yang", "Li Lin", "" ], [ "Jin", "Li Gang", "" ] ]
We evaluate the $t\bar{c}$ and $t\bar{u}$ productions at the LHC within the general unconstrained MSSM framework. We find that these single top quark productions induced by SUSY-QCD FCNC couplings have remarkable cross sections for favorable parameter values allowed by current low energy data, which can be as large as a few pb. Once large rates of the $t\bar{c}$ and $t\bar{u}$ productions are detected at the LHC, they may be induced by SUSY FCNC couplings. We show that the precise measurement of single top quark production cross sections at the LHC is a powerful probe for the details of the SUSY FCNC couplings.
hep-ph/9811269
Antonio Ferrera
Antonio Ferrera
How does the geodesic rule really work for global symmetry breaking first order phase transitions?
10 pages, 9 multiple figres
Phys. Rev. D 59, 123503 (1999)
10.1103/PhysRevD.59.123503
null
hep-ph
null
The chain of events usually understood to lead to the formation of topological defects during phase transitions is known as the Kibble mechanism. A central component of the mechanism is the so-called ``geodesic rule''. Although in the Abelian Higgs model the validity of the geodesic rule has been questioned recently, it is known to be valid on energetic grounds for a global U(1) symmetry breaking transition. However, even for these globally symmetric models no dynamical analisys of the rule has been carried to this date, and some points as to how events proceed still remain obscure. This paper tries to clarify the dynamics of the geodesic rule in the context of a global U(1) model. With an appropriate ansatz for the field modulus we find a family of analytical expressions, phase walls, that accounts for both geodesic and nongeodesic configurations. We then show how the latter ones are unstable and decay into the former by nucleating pairs of defects. Finnally, we try to give a physical perspective of how the geodesic rule might really work in these transitions.
[ { "created": "Sat, 7 Nov 1998 00:03:59 GMT", "version": "v1" } ]
2016-08-25
[ [ "Ferrera", "Antonio", "" ] ]
The chain of events usually understood to lead to the formation of topological defects during phase transitions is known as the Kibble mechanism. A central component of the mechanism is the so-called ``geodesic rule''. Although in the Abelian Higgs model the validity of the geodesic rule has been questioned recently, it is known to be valid on energetic grounds for a global U(1) symmetry breaking transition. However, even for these globally symmetric models no dynamical analisys of the rule has been carried to this date, and some points as to how events proceed still remain obscure. This paper tries to clarify the dynamics of the geodesic rule in the context of a global U(1) model. With an appropriate ansatz for the field modulus we find a family of analytical expressions, phase walls, that accounts for both geodesic and nongeodesic configurations. We then show how the latter ones are unstable and decay into the former by nucleating pairs of defects. Finnally, we try to give a physical perspective of how the geodesic rule might really work in these transitions.
hep-ph/0001287
D. Indumathi
Dilip Kumar Ghosh and Sourendu Gupta (TIFR, Mumbai, India), D. Indumathi (IMSc, Chennai, India)
A QCD Analysis of Polarised Parton Densities
Revtex 17 pages, 19 postscript figures. Analysis extended to SU(2) flavour symmetric and nonsymmetric sea
Phys.Rev. D62 (2000) 094012
10.1103/PhysRevD.62.094012
TIFR/TH/00-04, IMSc/2000/01/02
hep-ph
null
We present the results of a QCD fit to global data on deep-inelastic polarised lepton-hadron scattering. We find that it is possible to fit the data with strongly broken SU(2) flavour for the polarised sea densities. This can easily be tested in $W$ production at polarised RHIC. The data fails to pin down polarised singlet sea quark and gluon densities. We explore the uncertainties in detail and show that improvement in statistics, achievable at polarised HERA for measurement of A_1 at moderately low values of x, have large payoffs in terms of the improvement in measurement of gluon and sea quark densities.
[ { "created": "Thu, 27 Jan 2000 18:41:54 GMT", "version": "v1" }, { "created": "Tue, 2 May 2000 11:33:50 GMT", "version": "v2" }, { "created": "Mon, 26 Feb 2001 11:24:48 GMT", "version": "v3" } ]
2009-10-31
[ [ "Ghosh", "Dilip Kumar", "", "TIFR, Mumbai, India" ], [ "Gupta", "Sourendu", "", "TIFR, Mumbai, India" ], [ "Indumathi", "D.", "", "IMSc, Chennai, India" ] ]
We present the results of a QCD fit to global data on deep-inelastic polarised lepton-hadron scattering. We find that it is possible to fit the data with strongly broken SU(2) flavour for the polarised sea densities. This can easily be tested in $W$ production at polarised RHIC. The data fails to pin down polarised singlet sea quark and gluon densities. We explore the uncertainties in detail and show that improvement in statistics, achievable at polarised HERA for measurement of A_1 at moderately low values of x, have large payoffs in terms of the improvement in measurement of gluon and sea quark densities.
2305.09188
Sk Jeesun
Dilip Kumar Ghosh, Anish Ghoshal, Sk Jeesun
Axion-like particle (ALP) portal freeze-in dark matter confronting ALP search experiments
Accepted in JHEP
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The relic density of Dark Matter (DM) in the freeze-in scenario is highly dependent on the evolution history of the universe and changes significantly in a non-standard (NS) cosmological framework prior to Big Bang Nucleosynthesis (BBN). In this scenario, an additional species dominates the energy budget of the universe at early times (before BBN), resulting in a larger cosmological expansion rate at a given temperature compared to the standard radiation-dominated (RD) universe. To investigate the production of DM in the freeze-in scenario, we consider both standard RD and NS cosmological picture before BBN and perform a comparative analysis. We extend the Standard Model (SM) particle content with a SM singlet DM particle $\chi $ and an axion-like particle (ALP) $a$. The interactions between ALP, SM particles, and DM are generated by higher dimensional effective operators. This setup allows the production of DM $\chi$ from SM bath through the mediation of ALP, via ALP-portal processes. These interactions involve non-renormalizable operators, leading to ultraviolet (UV) freeze-in, which depends on the reheating temperature ($T_{RH}$) of the early universe. In the NS cosmological scenario, the faster expansion rate suppresses the DM production processes, allowing for enhanced effective couplings between the visible and dark sectors to satisfy the observed DM abundance compared to RD scenario. This improved coupling increases the detection prospects for freeze-in DM via the ALP-portal, which is otherwise challenging to detect in RD universe due to small couplings involved. Using an effective field theory set-up, we show that various ALP searches such as in FASER, DUNE, and SHiP, etc. will be able to probe significant parameter space depending on the different model parameters.
[ { "created": "Tue, 16 May 2023 05:53:02 GMT", "version": "v1" }, { "created": "Tue, 5 Dec 2023 12:21:15 GMT", "version": "v2" } ]
2023-12-06
[ [ "Ghosh", "Dilip Kumar", "" ], [ "Ghoshal", "Anish", "" ], [ "Jeesun", "Sk", "" ] ]
The relic density of Dark Matter (DM) in the freeze-in scenario is highly dependent on the evolution history of the universe and changes significantly in a non-standard (NS) cosmological framework prior to Big Bang Nucleosynthesis (BBN). In this scenario, an additional species dominates the energy budget of the universe at early times (before BBN), resulting in a larger cosmological expansion rate at a given temperature compared to the standard radiation-dominated (RD) universe. To investigate the production of DM in the freeze-in scenario, we consider both standard RD and NS cosmological picture before BBN and perform a comparative analysis. We extend the Standard Model (SM) particle content with a SM singlet DM particle $\chi $ and an axion-like particle (ALP) $a$. The interactions between ALP, SM particles, and DM are generated by higher dimensional effective operators. This setup allows the production of DM $\chi$ from SM bath through the mediation of ALP, via ALP-portal processes. These interactions involve non-renormalizable operators, leading to ultraviolet (UV) freeze-in, which depends on the reheating temperature ($T_{RH}$) of the early universe. In the NS cosmological scenario, the faster expansion rate suppresses the DM production processes, allowing for enhanced effective couplings between the visible and dark sectors to satisfy the observed DM abundance compared to RD scenario. This improved coupling increases the detection prospects for freeze-in DM via the ALP-portal, which is otherwise challenging to detect in RD universe due to small couplings involved. Using an effective field theory set-up, we show that various ALP searches such as in FASER, DUNE, and SHiP, etc. will be able to probe significant parameter space depending on the different model parameters.
1806.10962
Evgeny Akhmedov
Evgeny Akhmedov, Giorgio Arcadi, Manfred Lindner and Stefan Vogl
Coherent scattering and macroscopic coherence: Implications for neutrino, dark matter and axion detection
LaTeX, 31 page, 2 figures. v2: a section on coherent axion detection and an appendix added; title modified
null
10.1007/JHEP10(2018)045
null
hep-ph astro-ph.CO hep-ex nucl-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the question of whether coherent neutrino scattering can occur on macroscopic scales, leading to a significant increase of the detection cross section. We concentrate on radiative neutrino scattering on atomic electrons (or on free electrons in a conductor). Such processes can be coherent provided that the net electron recoil momentum, i.e. the momentum transfer from the neutrino minus the momentum of the emitted photon, is sufficiently small. The radiative processes is an attractive possibility as the energy of the emitted photons can be as large as the momentum transfer to the electron system and therefore the problem of detecting extremely low energy recoils can be avoided. The requirement of macroscopic coherence severely constrains the phase space available for the scattered particle and the emitted photon. We show that in the case of the scattering mediated by the usual weak neutral current and charged current interactions this leads to a strong suppression of the elementary cross sections and therefore the requirement of macroscopic coherence results in a reduction rather than an increase of the total detection cross section. However, for the $\nu e$ scattering mediated by neutrino magnetic or electric dipole moments coherence effects can actually increase the detection rates. Effects of macroscopic coherence can also allow detection of neutrinos in 100 eV -- a few keV energy range, which is currently not accessible to the experiment. A similar coherent enhancement mechanism can work for relativistic particles in the dark sector, but not for the conventionally considered non-relativistic dark matter.
[ { "created": "Thu, 28 Jun 2018 13:38:03 GMT", "version": "v1" }, { "created": "Thu, 2 Aug 2018 10:24:27 GMT", "version": "v2" } ]
2018-11-14
[ [ "Akhmedov", "Evgeny", "" ], [ "Arcadi", "Giorgio", "" ], [ "Lindner", "Manfred", "" ], [ "Vogl", "Stefan", "" ] ]
We study the question of whether coherent neutrino scattering can occur on macroscopic scales, leading to a significant increase of the detection cross section. We concentrate on radiative neutrino scattering on atomic electrons (or on free electrons in a conductor). Such processes can be coherent provided that the net electron recoil momentum, i.e. the momentum transfer from the neutrino minus the momentum of the emitted photon, is sufficiently small. The radiative processes is an attractive possibility as the energy of the emitted photons can be as large as the momentum transfer to the electron system and therefore the problem of detecting extremely low energy recoils can be avoided. The requirement of macroscopic coherence severely constrains the phase space available for the scattered particle and the emitted photon. We show that in the case of the scattering mediated by the usual weak neutral current and charged current interactions this leads to a strong suppression of the elementary cross sections and therefore the requirement of macroscopic coherence results in a reduction rather than an increase of the total detection cross section. However, for the $\nu e$ scattering mediated by neutrino magnetic or electric dipole moments coherence effects can actually increase the detection rates. Effects of macroscopic coherence can also allow detection of neutrinos in 100 eV -- a few keV energy range, which is currently not accessible to the experiment. A similar coherent enhancement mechanism can work for relativistic particles in the dark sector, but not for the conventionally considered non-relativistic dark matter.
hep-ph/0507209
Ramazan Sever
Sameer M. Ikhdair and Ramazan Sever
Bound Energy Masses of Mesons Containing the Fourth Generation and Iso-singlet Quarks
13 pages
Int.J.Mod.Phys. A21 (2006) 2191-2200
10.1142/S0217751X06031636
null
hep-ph
null
The fourth Standard Model (SM) family quarks and weak iso-singlet quarks The fourth Standard Model (SM) family quarks and weak iso-singlet quarks predicted by ${\rm E}_{6\text{}}$ GUT are considered. The spin-average of the pseudoscalar $\eta_{4}(n^{1}S_{0})$ and vector $\psi_{4}(n^{3}S_{1})$ quarkonium binding masses of the new mesons formed by the fourth Standard Model (SM) family and iso-singlet ${\rm E}_{6\text{}}$ with their mixings to ordinary quarks are investigated. Further, the fine and hyperfine mass splittings of the these states are also calculated. We solved the Schr\"{o}dinger equation with logarithmic and Martin potentials using the Shifted large-${\rm N}$ expansion technique. Our results are compared with other models to gauge the reliability of the predictions and point out differences.
[ { "created": "Mon, 18 Jul 2005 12:07:07 GMT", "version": "v1" } ]
2009-11-11
[ [ "Ikhdair", "Sameer M.", "" ], [ "Sever", "Ramazan", "" ] ]
The fourth Standard Model (SM) family quarks and weak iso-singlet quarks The fourth Standard Model (SM) family quarks and weak iso-singlet quarks predicted by ${\rm E}_{6\text{}}$ GUT are considered. The spin-average of the pseudoscalar $\eta_{4}(n^{1}S_{0})$ and vector $\psi_{4}(n^{3}S_{1})$ quarkonium binding masses of the new mesons formed by the fourth Standard Model (SM) family and iso-singlet ${\rm E}_{6\text{}}$ with their mixings to ordinary quarks are investigated. Further, the fine and hyperfine mass splittings of the these states are also calculated. We solved the Schr\"{o}dinger equation with logarithmic and Martin potentials using the Shifted large-${\rm N}$ expansion technique. Our results are compared with other models to gauge the reliability of the predictions and point out differences.
1703.09086
Fu-Sheng Yu
Fu-Sheng Yu, Hua-Yu Jiang, Run-Hui Li, Cai-Dian L\"u, Wei Wang and Zhen-Xing Zhao
Discovery Potentials of Doubly Charmed Baryons
16 pages, 3 figure, 5 tables. Version to be published in CPC
null
10.1088/1674-1137/42/5/051001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The existence of doubly heavy flavor baryons has not been well established experimentally so far. In this Letter we systematically investigate the weak decays of the doubly charmed baryons, $\Xi_{cc}^{++}$ and $\Xi_{cc}^{+}$, which would be helpful for experimental searches for these particles. The branching fractions are studied under the factorization hypothesis for the short-distance contributions and considering the rescattering effect for the long-distance contributions which are significantly enhanced. Comparing all the decay modes, we recommend the processes of $\Xi_{cc}^{++}\to \Lambda_c^+K^-\pi^+\pi^+$ and $\Xi_c^+\pi^+$ as the first priority for experiments to search for the doubly heavy baryons.
[ { "created": "Mon, 27 Mar 2017 14:02:46 GMT", "version": "v1" }, { "created": "Fri, 7 Jul 2017 14:20:46 GMT", "version": "v2" }, { "created": "Mon, 19 Mar 2018 12:51:31 GMT", "version": "v3" } ]
2018-05-23
[ [ "Yu", "Fu-Sheng", "" ], [ "Jiang", "Hua-Yu", "" ], [ "Li", "Run-Hui", "" ], [ "Lü", "Cai-Dian", "" ], [ "Wang", "Wei", "" ], [ "Zhao", "Zhen-Xing", "" ] ]
The existence of doubly heavy flavor baryons has not been well established experimentally so far. In this Letter we systematically investigate the weak decays of the doubly charmed baryons, $\Xi_{cc}^{++}$ and $\Xi_{cc}^{+}$, which would be helpful for experimental searches for these particles. The branching fractions are studied under the factorization hypothesis for the short-distance contributions and considering the rescattering effect for the long-distance contributions which are significantly enhanced. Comparing all the decay modes, we recommend the processes of $\Xi_{cc}^{++}\to \Lambda_c^+K^-\pi^+\pi^+$ and $\Xi_c^+\pi^+$ as the first priority for experiments to search for the doubly heavy baryons.
1111.3533
Jialun Ping
Shaona Chen, Jialun Ping
X(1835), X(2120), X(2370) and $\eta(1760)$ in chiral quark model
9 pages, 5 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
By analyzing the meson spectra obtained in the constituent quark model, we find that the pseudoscalar mesons $\eta'(2^1S_0)$, $\eta(4^1S_0)$, $\eta'(3^1S_0)$ and $\eta'(4^1S_0)$ are the possible candidates of $\eta(1760)$, X(1835), X(2120) and X(2370). The strong decay widths of these pseudoscalars to all the possible decay modes are calculated within the framework of the $^3P_0$ model. Although the total width of $\eta'(2^1S_0)$ is compatible with the experimental value of BES for $\eta(1760)$, the partial decay width to $\omega\omega$ is too small, which is not consistent with the result of BES. If the state X(1835) is interpreted as $\eta(4^1S_0)$, the total decay width is compatible with the experimental data, and the main decay modes will be $\pi a_0(980)$ and $\pi a_0(1450)$, which needs to be checked. The assignment of X(2120) and X(2370) to $\eta'(3^1S_0)$ and $\eta'(4^1S_0)$ is also disfavored in the present calculation because of the incompatibility of the decay widths.
[ { "created": "Tue, 15 Nov 2011 14:30:37 GMT", "version": "v1" } ]
2011-11-16
[ [ "Chen", "Shaona", "" ], [ "Ping", "Jialun", "" ] ]
By analyzing the meson spectra obtained in the constituent quark model, we find that the pseudoscalar mesons $\eta'(2^1S_0)$, $\eta(4^1S_0)$, $\eta'(3^1S_0)$ and $\eta'(4^1S_0)$ are the possible candidates of $\eta(1760)$, X(1835), X(2120) and X(2370). The strong decay widths of these pseudoscalars to all the possible decay modes are calculated within the framework of the $^3P_0$ model. Although the total width of $\eta'(2^1S_0)$ is compatible with the experimental value of BES for $\eta(1760)$, the partial decay width to $\omega\omega$ is too small, which is not consistent with the result of BES. If the state X(1835) is interpreted as $\eta(4^1S_0)$, the total decay width is compatible with the experimental data, and the main decay modes will be $\pi a_0(980)$ and $\pi a_0(1450)$, which needs to be checked. The assignment of X(2120) and X(2370) to $\eta'(3^1S_0)$ and $\eta'(4^1S_0)$ is also disfavored in the present calculation because of the incompatibility of the decay widths.
hep-ph/9901224
Kiselev Valery V.
V.V. Kiselev, A.K. Likhoded, A.I. Onishchenko
Lifetimes of Xi_{bc}^{+} and Xi_{bc}^{0} baryons
15 pages, LATEX file, 2 eps-figures
Eur.Phys.J.C16:461-469,2000
10.1007/s100520000433
null
hep-ph
null
Estimates of lifetimes and partial branching ratios for the baryons $\Xi_{bc}^{+}$ and $\Xi_{bc}^{0}$ are presented using the inverse heavy quark mass expansion technique carried out in the Operator Product Expansion approach. We take into account both the perturbative QCD corrections to the spectator contributions and, depending on the quark contents of hadrons, the Pauli interference and weak scattering effects between the constituents, using a potential model for the evaluation of the non-perturbative parameters.
[ { "created": "Tue, 5 Jan 1999 16:18:14 GMT", "version": "v1" } ]
2009-01-07
[ [ "Kiselev", "V. V.", "" ], [ "Likhoded", "A. K.", "" ], [ "Onishchenko", "A. I.", "" ] ]
Estimates of lifetimes and partial branching ratios for the baryons $\Xi_{bc}^{+}$ and $\Xi_{bc}^{0}$ are presented using the inverse heavy quark mass expansion technique carried out in the Operator Product Expansion approach. We take into account both the perturbative QCD corrections to the spectator contributions and, depending on the quark contents of hadrons, the Pauli interference and weak scattering effects between the constituents, using a potential model for the evaluation of the non-perturbative parameters.
0907.2941
C. Pallis
S. Lola, C. Pallis and E. Tzelati
Tracking Quintessence and Cold Dark Matter Candidates
Final version
JCAP 0911:017,2009
10.1088/1475-7516/2009/11/017
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the generation of a kination-dominated phase in the context of a quintessential model with an inverse-power-law potential and a Hubble-induced mass term for the quintessence field. The presence of kination is associated with an oscillating evolution of the quintessence field and the barotropic index. We find that, in sizeable regions of the parameter space, a tracker scaling solution can be reached sufficiently early to alleviate the coincidence problem. Other observational constraints originating from nucleosynthesis, the inflationary scale, the present acceleration of the universe and the dark-energy-density parameter can be also met. The impact of this modified kination-dominated phase on the thermal abundance of cold dark matter candidates is investigated too. We find that: (i) the enhancement of the relic abundance of the WIMPs with respect to the standard paradigm, crucially depends on the hierarchy between the freeze-out temperature and the temperature at which the extrema in the evolution of the quintessence field are encountered, and (ii) the relic abundance of e-WIMPs takes its present value close to the temperature at which the earliest extremum of the evolution of the quintessence field occurs and, as a consequence, both gravitinos and axinos arise as natural cold dark matter candidates. In the case of unstable gravitinos, the gravitino constraint can be satisfied for values of the initial temperature well above those required in the standard cosmology.
[ { "created": "Fri, 17 Jul 2009 19:10:05 GMT", "version": "v1" }, { "created": "Wed, 21 Oct 2009 22:18:44 GMT", "version": "v2" }, { "created": "Wed, 24 Feb 2010 17:57:16 GMT", "version": "v3" } ]
2010-02-24
[ [ "Lola", "S.", "" ], [ "Pallis", "C.", "" ], [ "Tzelati", "E.", "" ] ]
We study the generation of a kination-dominated phase in the context of a quintessential model with an inverse-power-law potential and a Hubble-induced mass term for the quintessence field. The presence of kination is associated with an oscillating evolution of the quintessence field and the barotropic index. We find that, in sizeable regions of the parameter space, a tracker scaling solution can be reached sufficiently early to alleviate the coincidence problem. Other observational constraints originating from nucleosynthesis, the inflationary scale, the present acceleration of the universe and the dark-energy-density parameter can be also met. The impact of this modified kination-dominated phase on the thermal abundance of cold dark matter candidates is investigated too. We find that: (i) the enhancement of the relic abundance of the WIMPs with respect to the standard paradigm, crucially depends on the hierarchy between the freeze-out temperature and the temperature at which the extrema in the evolution of the quintessence field are encountered, and (ii) the relic abundance of e-WIMPs takes its present value close to the temperature at which the earliest extremum of the evolution of the quintessence field occurs and, as a consequence, both gravitinos and axinos arise as natural cold dark matter candidates. In the case of unstable gravitinos, the gravitino constraint can be satisfied for values of the initial temperature well above those required in the standard cosmology.
hep-ph/0012368
Onofre Rojas
Onofre Rojas, S. M. de Souza and M. T. Thomaz
High Temperature Expansion for a Chain Model
20 pages, 2 figures
J.Math.Phys. 43 (2002) 1390-1407
10.1063/1.1432484
null
hep-ph cond-mat.stat-mech hep-th
null
We consider an arbitrary translationally invariant chain model with nearest neighbors interaction and satisfying periodic boundary condition. The approach developed here allows a thermodynamic description of the chain model directly in terms of grand potential per site. This thermodynamic function is derived from an auxiliary function constructed only from open connected sub-chains. In order to exemplify its application and how this approach works we consider the Heisenberg XXZ model. We obtain the coefficients of the high temperature expansion of the free energy per site of the model up to third order.
[ { "created": "Fri, 29 Dec 2000 00:15:55 GMT", "version": "v1" }, { "created": "Fri, 22 Jun 2001 14:12:54 GMT", "version": "v2" } ]
2016-09-06
[ [ "Rojas", "Onofre", "" ], [ "de Souza", "S. M.", "" ], [ "Thomaz", "M. T.", "" ] ]
We consider an arbitrary translationally invariant chain model with nearest neighbors interaction and satisfying periodic boundary condition. The approach developed here allows a thermodynamic description of the chain model directly in terms of grand potential per site. This thermodynamic function is derived from an auxiliary function constructed only from open connected sub-chains. In order to exemplify its application and how this approach works we consider the Heisenberg XXZ model. We obtain the coefficients of the high temperature expansion of the free energy per site of the model up to third order.
hep-ph/9905317
C. T. Chan
Chuan-Tsung Chan, Ernest M. Henley, Thomas Meissner
Nucleon Electric Dipole Moments from QCD Sum Rules
This paper, together with hep-ph/9704427, are abridged versions of the Ph.D thesis of the first author
null
null
DOE/ER/41014-13-N97
hep-ph
null
The electric dipole moments of nucleons (NEDM, d_N) are calculated using the method of QCD sum rules. Our calculations are based on the parity and time reversal violating parameter $\thetabar$ in QCD and establish a functional dependence of the NEDM on $\thetabar$, without assuming a perturbative expansion of this symmetry breaking parameter. The results obtained from the QCD sum rules approach are shown to be consistent with the general symmetry constraints on CP violations in QCD, including the necessity of: (1) finite quark masses, (2) spontaneous chiral symmetry breaking, and (3) the U_A(1) anomaly. Given the current experimental upper bound on the neutron electric dipole moment (nEDM), d_n < 10^(-25) e-cm, we find | \thetabar | < 10^(-9). This result is compatible with previous calculations of nEDM using different techniques and excludes the possibility of solving the strong CP problem within QCD via a dynamical suppression mechanism.
[ { "created": "Wed, 12 May 1999 10:14:19 GMT", "version": "v1" } ]
2007-05-23
[ [ "Chan", "Chuan-Tsung", "" ], [ "Henley", "Ernest M.", "" ], [ "Meissner", "Thomas", "" ] ]
The electric dipole moments of nucleons (NEDM, d_N) are calculated using the method of QCD sum rules. Our calculations are based on the parity and time reversal violating parameter $\thetabar$ in QCD and establish a functional dependence of the NEDM on $\thetabar$, without assuming a perturbative expansion of this symmetry breaking parameter. The results obtained from the QCD sum rules approach are shown to be consistent with the general symmetry constraints on CP violations in QCD, including the necessity of: (1) finite quark masses, (2) spontaneous chiral symmetry breaking, and (3) the U_A(1) anomaly. Given the current experimental upper bound on the neutron electric dipole moment (nEDM), d_n < 10^(-25) e-cm, we find | \thetabar | < 10^(-9). This result is compatible with previous calculations of nEDM using different techniques and excludes the possibility of solving the strong CP problem within QCD via a dynamical suppression mechanism.
hep-ph/0605185
Leszek Motyka
Sergey Bondarenko and Leszek Motyka
Solving effective field theory of interacting QCD pomerons in the semi-classical approximation
References added, misprints corrected
Phys.Rev.D75:114015,2007
10.1103/PhysRevD.75.114015
null
hep-ph
null
Effective field theory of BFKL pomerons interacting by QCD triple pomeron vertices is investigated. Classical equations of motion for the effective pomeron fields are presented being a minimal extension of the Balitsky-Kovchegov equation that incorporates both merging and splitting of the pomerons and that is self-dual. The equations are solved for symmetric boundary conditions. The solutions provide the dominant contribution to the scattering amplitudes in the semi-classical approximation. We find that for rapidities of the scattering larger than a critical value Y_c at least two classical solutions exist. Curiously, for each of the two classical solutions with the lowest action the symmetry between the projectile and the target is found to be spontaneously broken, being however preserved for the complete set of classical solutions. The solving configurations at rapidities Y>Y_c consist of a Gribov field being strongly suppressed even at very large gluon momenta and the complementary Gribov field that converges at high Y to a solution of Balitsky-Kovchegov equation. Interpretation of the results is given and possible consequences are shortly discussed.
[ { "created": "Tue, 16 May 2006 12:33:23 GMT", "version": "v1" }, { "created": "Tue, 20 Jun 2006 23:03:09 GMT", "version": "v2" } ]
2008-11-26
[ [ "Bondarenko", "Sergey", "" ], [ "Motyka", "Leszek", "" ] ]
Effective field theory of BFKL pomerons interacting by QCD triple pomeron vertices is investigated. Classical equations of motion for the effective pomeron fields are presented being a minimal extension of the Balitsky-Kovchegov equation that incorporates both merging and splitting of the pomerons and that is self-dual. The equations are solved for symmetric boundary conditions. The solutions provide the dominant contribution to the scattering amplitudes in the semi-classical approximation. We find that for rapidities of the scattering larger than a critical value Y_c at least two classical solutions exist. Curiously, for each of the two classical solutions with the lowest action the symmetry between the projectile and the target is found to be spontaneously broken, being however preserved for the complete set of classical solutions. The solving configurations at rapidities Y>Y_c consist of a Gribov field being strongly suppressed even at very large gluon momenta and the complementary Gribov field that converges at high Y to a solution of Balitsky-Kovchegov equation. Interpretation of the results is given and possible consequences are shortly discussed.
1311.6537
Dmitry Melnikov
Ivan Gordeli and Dmitry Melnikov
Calculation of glueball spectra in supersymmetric theories via holography
10 pages, 2 figures; Proceedings of the workshop "Low X Physics", Israel, May 30 - June 4, 2013
null
null
null
hep-ph hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Lattice simulations currently present the only way to access nonperturbative data in strongly coupled theories from a first principle calculation. However, in supersymmetric theories this valuable tool is not available due to the technical sign problem. We are going to demonstrate that in the case of glueball spectra a good quantitative estimate for the lightest states of low spin can be obtained by means of the holographic approach. We will review the results of the calculation in the singlet glueball sector of the N=1 supersymmetric Klebanov-Strassler model. We come up with a prediction of the spectrum of lightest glueballs in (large Nc) N=1 supersymmetric Yang-Mills theory.
[ { "created": "Tue, 26 Nov 2013 01:25:32 GMT", "version": "v1" } ]
2013-11-27
[ [ "Gordeli", "Ivan", "" ], [ "Melnikov", "Dmitry", "" ] ]
Lattice simulations currently present the only way to access nonperturbative data in strongly coupled theories from a first principle calculation. However, in supersymmetric theories this valuable tool is not available due to the technical sign problem. We are going to demonstrate that in the case of glueball spectra a good quantitative estimate for the lightest states of low spin can be obtained by means of the holographic approach. We will review the results of the calculation in the singlet glueball sector of the N=1 supersymmetric Klebanov-Strassler model. We come up with a prediction of the spectrum of lightest glueballs in (large Nc) N=1 supersymmetric Yang-Mills theory.
0802.1736
Neil Russell
Neil Russell
Tests of Lorentz symmetry using antihydrogen
11pp, invited talk at PQE 37 Conference, Snowbird, Utah, USA, 2-6 Jan 2007
J.Mod.Opt.54:2481-2490,2007
10.1080/09500340701397552
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Signals of CPT and Lorentz violation are possible in the context of spectroscopy using hydrogen and antihydrogen. We apply the Standard-Model Extension, a broad framework for Lorentz breaking in physics, to various transitions in the hydrogen and antihydrogen spectra. The results show an unsuppressed effect in the transition between the upper two hyperfine sublevels of the ground state of these systems. We also discuss related tests in Penning traps, and recent work on Lorentz violation in curved spacetime.
[ { "created": "Tue, 12 Feb 2008 23:09:36 GMT", "version": "v1" } ]
2008-11-26
[ [ "Russell", "Neil", "" ] ]
Signals of CPT and Lorentz violation are possible in the context of spectroscopy using hydrogen and antihydrogen. We apply the Standard-Model Extension, a broad framework for Lorentz breaking in physics, to various transitions in the hydrogen and antihydrogen spectra. The results show an unsuppressed effect in the transition between the upper two hyperfine sublevels of the ground state of these systems. We also discuss related tests in Penning traps, and recent work on Lorentz violation in curved spacetime.
1909.00451
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
Recent QCD results from the xFitter project: Probing the strange content of the proton with charm production in charged current at LHeC
6 pages, 3 figures. DIS2019 Workshop, Torino, Italy [Conf. report of arXiv:1907.01014]
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate charm production in charged-current deep-inelastic scattering (DIS) using the xFitter program. xFitter is an open-source software framework for the determination of PDFs and the analysis of QCD physics, and has been used for a variety of LHC studies. The study of charged current DIS charm production provides an important perspective on the strange quark PDF, s(x). We make use of the xFitter tools to study the present s(x) constraints, and then use LHeC pseudodata to infer how these might improve. Furthermore, as xFitter implements both Fixed Flavor and Variable Flavor number schemes, we can examine the impact of these different theoretical choices; this highlights some interesting aspects of multi-scale calculations. This study provides a practical illustration of the many features of xFitter.
[ { "created": "Sun, 1 Sep 2019 19:17:43 GMT", "version": "v1" } ]
2019-09-04
[ [ "xFitter Developers Team", "", "" ], [ "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 investigate charm production in charged-current deep-inelastic scattering (DIS) using the xFitter program. xFitter is an open-source software framework for the determination of PDFs and the analysis of QCD physics, and has been used for a variety of LHC studies. The study of charged current DIS charm production provides an important perspective on the strange quark PDF, s(x). We make use of the xFitter tools to study the present s(x) constraints, and then use LHeC pseudodata to infer how these might improve. Furthermore, as xFitter implements both Fixed Flavor and Variable Flavor number schemes, we can examine the impact of these different theoretical choices; this highlights some interesting aspects of multi-scale calculations. This study provides a practical illustration of the many features of xFitter.
hep-ph/9512341
null
G. Kramer (DESY), W. Palmer (OSU) and Y.L. Wu (OSU)
Extraction of $\alpha$ From the CP Asymmetry in B^0/\bar B^0 --> pi+ pi- Decays
15 pages, Latex, three figures available upon request
Commun.Theor.Phys. 27 (1997) 457-464
null
DESY 95-246, DOE/ER/01545-605
hep-ph
null
The influence of strong and electroweak penguin amplitudes in $B/ \bar B \rightarrow \pi^+\pi^-$ is investigated in connection with the determination of the unitarity triangle angle $\alpha$ of the CKM matrix. A relation between the observable asymmetry, the angle $\alpha$, and the penguin amplitude is established. A model calculation of the penguin amplitude shows that the CP asymmetry in $B^{0}\rightarrow \pi^{+}\pi^{-}$ decays is only mildly influenced by the penguin amplitudes. Experimental limits on pure penguin and penguin dominated processes are consistent with the model. This information also suggests in a rather model independent way that penguin amplitudes will not be a serious complicating factor in the determination of $\alpha$ from the $\pi^{+}\pi^{-}$ time dependent asymmetry.
[ { "created": "Mon, 18 Dec 1995 18:21:09 GMT", "version": "v1" } ]
2009-09-25
[ [ "Kramer", "G.", "", "DESY" ], [ "Palmer", "W.", "", "OSU" ], [ "Wu", "Y. L.", "", "OSU" ] ]
The influence of strong and electroweak penguin amplitudes in $B/ \bar B \rightarrow \pi^+\pi^-$ is investigated in connection with the determination of the unitarity triangle angle $\alpha$ of the CKM matrix. A relation between the observable asymmetry, the angle $\alpha$, and the penguin amplitude is established. A model calculation of the penguin amplitude shows that the CP asymmetry in $B^{0}\rightarrow \pi^{+}\pi^{-}$ decays is only mildly influenced by the penguin amplitudes. Experimental limits on pure penguin and penguin dominated processes are consistent with the model. This information also suggests in a rather model independent way that penguin amplitudes will not be a serious complicating factor in the determination of $\alpha$ from the $\pi^{+}\pi^{-}$ time dependent asymmetry.
1403.6944
Heikki M\"antysaari
T. Lappi and H. M\"antysaari
Particle production from the Color Glass Condensate: proton-nucleus collisions in light of the HERA data
4 pages, 4 figures, talk given at the 6th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions (Hard Probes 2013), November 4-8, 2013 (Cape Town, South Africa)
null
10.1016/j.nuclphysa.2014.08.038
Nucl. Phys. A932 (2014) 549-554
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute single inclusive hadron production in proton-proton and proton-nucleus collisions consistently within the CGC framework. The parameters in the calculations are obtained from electron-proton DIS and standard nuclear geometry. We obtain a good description of the DIS data without an anomalous dimension in the initial condition of the BK evolution and get a good agreement with the available single inclusive proton-proton and proton-nucleus data.
[ { "created": "Thu, 27 Mar 2014 08:10:23 GMT", "version": "v1" } ]
2015-02-10
[ [ "Lappi", "T.", "" ], [ "Mäntysaari", "H.", "" ] ]
We compute single inclusive hadron production in proton-proton and proton-nucleus collisions consistently within the CGC framework. The parameters in the calculations are obtained from electron-proton DIS and standard nuclear geometry. We obtain a good description of the DIS data without an anomalous dimension in the initial condition of the BK evolution and get a good agreement with the available single inclusive proton-proton and proton-nucleus data.
hep-ph/0110031
Kainulainen
James M. Cline, Michael Joyce and Kimmo Kainulainen
Erratum for "Supersymmetric Electroweak Baryogenesis"
65K, LaTex, 5p, 3 eps figures, uses JHEP.cls (included)
null
null
null
hep-ph
null
We correct a numerical error which led to an overestimate of the baryon asymmetry from supersymmetric electroweak baryogenesis in our paper JHEP07(2000)018. Updated dependences of the baryon asymmetry on chargino mass parameters and the bubble wall velocity are shown. We also include LEP-II-constraints on the chargino mass parameters. Combined with our corrected results for the baryon asymmetry these constraints imply that the phase in the chargino mass matrix must violate CP nearly maximally in order to generate a large enough baryon asymmetry. A number of other typographical errors are also corrected.
[ { "created": "Tue, 2 Oct 2001 09:23:32 GMT", "version": "v1" } ]
2007-05-23
[ [ "Cline", "James M.", "" ], [ "Joyce", "Michael", "" ], [ "Kainulainen", "Kimmo", "" ] ]
We correct a numerical error which led to an overestimate of the baryon asymmetry from supersymmetric electroweak baryogenesis in our paper JHEP07(2000)018. Updated dependences of the baryon asymmetry on chargino mass parameters and the bubble wall velocity are shown. We also include LEP-II-constraints on the chargino mass parameters. Combined with our corrected results for the baryon asymmetry these constraints imply that the phase in the chargino mass matrix must violate CP nearly maximally in order to generate a large enough baryon asymmetry. A number of other typographical errors are also corrected.
hep-ph/0403102
Kazutaka Sudoh
Masanori Hirai and Kazutaka Sudoh
Effect of polarized gluon distribution on spin asymmetries for neutral and charged pion production
7 pages, 5 eps figures, section added, typos corrected. to be published in PRD
Phys.Rev. D71 (2005) 014022
10.1103/PhysRevD.71.014022
RIKEN-AF-NP456
hep-ph
null
A longitudinal double spin asymmetry for \pi^0 production has been measured by the PHENIX collaboration. The asymmetry is sensitive to the polarized gluon distribution and is indicated to be positive by theoretical predictions. We study a correlation between behavior of the asymmetry and polarized gluon distribution in neutral and charged pion production at RHIC.
[ { "created": "Tue, 9 Mar 2004 15:10:50 GMT", "version": "v1" }, { "created": "Thu, 13 Jan 2005 08:31:27 GMT", "version": "v2" } ]
2009-11-10
[ [ "Hirai", "Masanori", "" ], [ "Sudoh", "Kazutaka", "" ] ]
A longitudinal double spin asymmetry for \pi^0 production has been measured by the PHENIX collaboration. The asymmetry is sensitive to the polarized gluon distribution and is indicated to be positive by theoretical predictions. We study a correlation between behavior of the asymmetry and polarized gluon distribution in neutral and charged pion production at RHIC.
1702.03776
Igor Ivanov
Igor P. Ivanov
Building and testing models with extended Higgs sectors
57 pages + 32-page bibliography, 10 figures; invited review for Progress in Particle and Nuclear Physics; v2: minor modifications, extra references
null
10.1016/j.ppnp.2017.03.001
CFTP/17-002
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Models with non-minimal Higgs sectors represent a mainstream direction in theoretical exploration of physics opportunities beyond the Standard Model. Extended scalar sectors help alleviate difficulties of the Standard Model and lead to a rich spectrum of characteristic collider signatures and astroparticle consequences. In this review, we introduce the reader to the world of extended Higgs sectors. Not pretending to exhaustively cover the entire body of literature, we walk through a selection of the most popular examples: the two- and multi-Higgs-doublet models, as well as singlet and triplet extensions. We will show how one typically builds models with extended Higgs sectors, describe the main goals and the challenges which arise on the way, and mention some methods to overcome them. We will also describe how such models can be tested, what are the key observables one focuses on, and illustrate the general strategy with a subjective selection of results.
[ { "created": "Mon, 13 Feb 2017 13:56:44 GMT", "version": "v1" }, { "created": "Thu, 2 Mar 2017 13:04:03 GMT", "version": "v2" } ]
2017-06-07
[ [ "Ivanov", "Igor P.", "" ] ]
Models with non-minimal Higgs sectors represent a mainstream direction in theoretical exploration of physics opportunities beyond the Standard Model. Extended scalar sectors help alleviate difficulties of the Standard Model and lead to a rich spectrum of characteristic collider signatures and astroparticle consequences. In this review, we introduce the reader to the world of extended Higgs sectors. Not pretending to exhaustively cover the entire body of literature, we walk through a selection of the most popular examples: the two- and multi-Higgs-doublet models, as well as singlet and triplet extensions. We will show how one typically builds models with extended Higgs sectors, describe the main goals and the challenges which arise on the way, and mention some methods to overcome them. We will also describe how such models can be tested, what are the key observables one focuses on, and illustrate the general strategy with a subjective selection of results.
hep-ph/0003140
Stephen D. H. Hsu
Stephen D.H. Hsu
Color Superconductivity in High Density Quark Matter
16 pages, 7 figures, latex, contribution to TMU-Yale Symposium on Dynamics of Gauge Fields
null
null
null
hep-ph
null
We review recent progress on the phenomena of color superconductivity in high density quark matter. We begin with a brief overview of the unique aspects of physics near a Fermi surface and the implications for renormalization group (RG) techniques. We next discuss the qualitative differences between asymptotic densities, where the effective coupling constant can be made arbitrarily small, and intermediate densities where quark matter is still strongly coupled. It is in the latter regime where RG techniques are particularly useful, in that they yield a generic description of possible behaviors without relying on an expansion in the strong coupling constant. Finally, we discuss aspects of the QCD groundstate at asymptotic densities, which can be determined in a systematic weak coupling expansion.
[ { "created": "Wed, 15 Mar 2000 07:25:54 GMT", "version": "v1" } ]
2007-05-23
[ [ "Hsu", "Stephen D. H.", "" ] ]
We review recent progress on the phenomena of color superconductivity in high density quark matter. We begin with a brief overview of the unique aspects of physics near a Fermi surface and the implications for renormalization group (RG) techniques. We next discuss the qualitative differences between asymptotic densities, where the effective coupling constant can be made arbitrarily small, and intermediate densities where quark matter is still strongly coupled. It is in the latter regime where RG techniques are particularly useful, in that they yield a generic description of possible behaviors without relying on an expansion in the strong coupling constant. Finally, we discuss aspects of the QCD groundstate at asymptotic densities, which can be determined in a systematic weak coupling expansion.
hep-ph/9401328
null
Stanley J. Brodsky, Matthias Burkardt, and Ivan Schmidt
QCD Constrains on the Shape of Polarized Quark and Gluon Distributions
Correct version of Fig. 1 added, LaTex, 27 pages, plus 4 figures
Nucl.Phys.B441:197-214,1995
10.1016/0550-3213(95)00009-H
SLAC-PUB-6087
hep-ph
null
We develop simple analytic representations of the polarized quark and gluon distributions in the nucleon at low $Q^2$ which incorporate general constraints obtained from the requirements of color coherence of gluon couplings at $x \sim 0$ and the helicity retention properties of perturbative QCD couplings at $x \sim 1.$ The unpolarized predictions are similar to the $D_0'$ distributions given by Martin, Roberts, and Stirling. The predictions for the quark helicity distributions are compared with polarized structure functions measured by the E142 experiment at SLAC and the SMC experiment at CERN.
[ { "created": "Tue, 25 Jan 1994 20:41:00 GMT", "version": "v1" }, { "created": "Mon, 9 Jun 1997 22:46:46 GMT", "version": "v2" } ]
2009-09-25
[ [ "Brodsky", "Stanley J.", "" ], [ "Burkardt", "Matthias", "" ], [ "Schmidt", "Ivan", "" ] ]
We develop simple analytic representations of the polarized quark and gluon distributions in the nucleon at low $Q^2$ which incorporate general constraints obtained from the requirements of color coherence of gluon couplings at $x \sim 0$ and the helicity retention properties of perturbative QCD couplings at $x \sim 1.$ The unpolarized predictions are similar to the $D_0'$ distributions given by Martin, Roberts, and Stirling. The predictions for the quark helicity distributions are compared with polarized structure functions measured by the E142 experiment at SLAC and the SMC experiment at CERN.
hep-ph/9706308
Bruno Machet
B. Machet
Two results concerning CP violation for J=0 mesons
10 pages, Latex with amssymbols
null
null
PAR-LPTHE 97/18
hep-ph
null
I show, in the framework of a SU(2)left x U(1) gauge theory for J=0 mesons expressed as scalar or pseudoscalar di-quark fields, that: - the existence, at the fermionic level, of a complex mixing matrix of the Kobayashi-Maskawa type is not a sufficient condition for electroweak mass eigenstates to be different from CP eigenstates; - unitarity constrains this phenomenon to arise from an admixture of states with different parities, and present experiments probing ``indirect'' CP violation are likely to be interpreted with P violation only.
[ { "created": "Tue, 10 Jun 1997 06:17:56 GMT", "version": "v1" } ]
2007-05-23
[ [ "Machet", "B.", "" ] ]
I show, in the framework of a SU(2)left x U(1) gauge theory for J=0 mesons expressed as scalar or pseudoscalar di-quark fields, that: - the existence, at the fermionic level, of a complex mixing matrix of the Kobayashi-Maskawa type is not a sufficient condition for electroweak mass eigenstates to be different from CP eigenstates; - unitarity constrains this phenomenon to arise from an admixture of states with different parities, and present experiments probing ``indirect'' CP violation are likely to be interpreted with P violation only.
hep-ph/9910364
A. Gall
A. Gall
Matching in Nonrelativistic Effective Quantum Field Theories
72 pages, 13 figures
null
null
BUTP-99/19
hep-ph
null
Nonrelativstic effective field theories have shown to be a useful framework to describe systems of weakly bound particles. This work focuses on the matching procedure to the underlying relativistic theory. The concept of a physical mass in the absence of explicit Lorentz symmetry and the matching conditions for S-matrix elements and Green's functions are discussed in general for scalar particles. The effective Lagrangians of the pure particle and anti-particle sectors are constructed explicitely for a Yukawa-type interaction of a heavy and a light scalar field. Using the proper matching, it is shown that they reproduce the corresponding relativistic amplitudes in a systematic expansion in inverse powers of the heavy mass.
[ { "created": "Fri, 15 Oct 1999 16:52:19 GMT", "version": "v1" } ]
2007-05-23
[ [ "Gall", "A.", "" ] ]
Nonrelativstic effective field theories have shown to be a useful framework to describe systems of weakly bound particles. This work focuses on the matching procedure to the underlying relativistic theory. The concept of a physical mass in the absence of explicit Lorentz symmetry and the matching conditions for S-matrix elements and Green's functions are discussed in general for scalar particles. The effective Lagrangians of the pure particle and anti-particle sectors are constructed explicitely for a Yukawa-type interaction of a heavy and a light scalar field. Using the proper matching, it is shown that they reproduce the corresponding relativistic amplitudes in a systematic expansion in inverse powers of the heavy mass.
1702.02097
Zhang Hong-Fei
Zhan Sun, Hong-Fei Zhang
QCD leading order study of the $J/\psi$ leptoproduction at HERA within the nonrelativistic QCD framework
null
null
10.1140/epjc/s10052-017-5323-6
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
As indicated in our previous paper (Phys.Rev.D96.034002), the existing literatures studying the $J/\psi$ production in deeply inelastic scattering (DIS) in collinear factorization are on the basis of a formalism that will lead to wrong results when the ranges of the transverse momentum or the rapidity of the $J/\psi$ in the laboratory frame do not cover all values possible for them. In this paper, we present the renewed results for the $J/\psi$ production in DIS at HERA within the nonrelativistic QCD framework at QCD leading order (LO). Three different sets of the long-distance matrix elements are employed for comparison. The predictions via the colour-singlet (CS) model at QCD LO are generally below the experimental data especially in the regions where perturbation theory are expected to work well, while the colour-octet contributions are of the same order of magnitude as the CS ones, however, in general make the agreement between theory and experiment better.
[ { "created": "Tue, 7 Feb 2017 16:54:36 GMT", "version": "v1" }, { "created": "Tue, 18 Jul 2017 15:19:23 GMT", "version": "v2" }, { "created": "Sun, 5 Nov 2017 07:03:45 GMT", "version": "v3" } ]
2017-12-06
[ [ "Sun", "Zhan", "" ], [ "Zhang", "Hong-Fei", "" ] ]
As indicated in our previous paper (Phys.Rev.D96.034002), the existing literatures studying the $J/\psi$ production in deeply inelastic scattering (DIS) in collinear factorization are on the basis of a formalism that will lead to wrong results when the ranges of the transverse momentum or the rapidity of the $J/\psi$ in the laboratory frame do not cover all values possible for them. In this paper, we present the renewed results for the $J/\psi$ production in DIS at HERA within the nonrelativistic QCD framework at QCD leading order (LO). Three different sets of the long-distance matrix elements are employed for comparison. The predictions via the colour-singlet (CS) model at QCD LO are generally below the experimental data especially in the regions where perturbation theory are expected to work well, while the colour-octet contributions are of the same order of magnitude as the CS ones, however, in general make the agreement between theory and experiment better.
2205.15755
Jin Hu
Jin Hu and Zhe Xu
Propagation of spin channel waves
Typos corrected, the version published in PRD
null
10.1103/PhysRevD.107.016010
null
hep-ph nucl-th
http://creativecommons.org/publicdomain/zero/1.0/
A mutilated model is constructed to approximate the collision term of spin Boltzmann equation that incorporates newly appearing collisional invariants i.e, the total angular momentum. With recourse to degenerate perturbation theory, the dispersion relations of hydrodynamic modes are formulated, among which spin modes are responsible for spin equilibration. We find that the non-locality does not change the sound speed but slows down the propagation of spin channel waves. The damping rates of spin modes are close to those of spinless modes over a reasonable parameter value range. The results reveal that both spin and momentum should be treated simultaneously in a unified transport framework. In the nonrelativistic limit, the short-wavelength behavior for normal modes is also explored and there exists a critical point for every distinct discrete mode over which only quasiparticle modes contribute.
[ { "created": "Tue, 31 May 2022 12:43:30 GMT", "version": "v1" }, { "created": "Fri, 20 Jan 2023 07:20:50 GMT", "version": "v2" } ]
2023-01-23
[ [ "Hu", "Jin", "" ], [ "Xu", "Zhe", "" ] ]
A mutilated model is constructed to approximate the collision term of spin Boltzmann equation that incorporates newly appearing collisional invariants i.e, the total angular momentum. With recourse to degenerate perturbation theory, the dispersion relations of hydrodynamic modes are formulated, among which spin modes are responsible for spin equilibration. We find that the non-locality does not change the sound speed but slows down the propagation of spin channel waves. The damping rates of spin modes are close to those of spinless modes over a reasonable parameter value range. The results reveal that both spin and momentum should be treated simultaneously in a unified transport framework. In the nonrelativistic limit, the short-wavelength behavior for normal modes is also explored and there exists a critical point for every distinct discrete mode over which only quasiparticle modes contribute.
0806.3579
Andrey Nazarenko
A.V. Nazarenko
Probability of Creation of Extra Dimensions in Nuclear Collisions
accepted in Int. J. Mod. Phys. E
Int.J.Mod.Phys.E17:1605-1618,2008
10.1142/S0218301308010593
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The minisuperspace model in $3+d$ spatial dimensions with the matter, described by the bag model, is considered with the aim to estimate the probability of creation of the compactified extra dimensions in nuclear collisions. The amplitude of transition from 3- to $3+d$-dimensional space has been calculated both in the case of completely confined matter, when contribution of radiation is ignored, and in the case of radiation domination, when the bag constant is negligible. It turns out that the number of additional dimensions is limited in the first regime, while this is infinite in the second one. It is shown that the probability of creation of extra dimensions is finite in the both regimes.
[ { "created": "Sun, 22 Jun 2008 16:53:29 GMT", "version": "v1" } ]
2010-04-21
[ [ "Nazarenko", "A. V.", "" ] ]
The minisuperspace model in $3+d$ spatial dimensions with the matter, described by the bag model, is considered with the aim to estimate the probability of creation of the compactified extra dimensions in nuclear collisions. The amplitude of transition from 3- to $3+d$-dimensional space has been calculated both in the case of completely confined matter, when contribution of radiation is ignored, and in the case of radiation domination, when the bag constant is negligible. It turns out that the number of additional dimensions is limited in the first regime, while this is infinite in the second one. It is shown that the probability of creation of extra dimensions is finite in the both regimes.
1206.5216
Alfredo Aranda
Carlos Alvarado, Alfredo Aranda, Olindo Corradini, Alma D. Rojas, Eli Santos-Rodriguez
Z_4 flavor model in Randall-Sundrum model 1
23 pages, 3 figures. A brief discussion on contribution from higher order operators has been added, a few typos corrected and references added. Version to appear in Phys. Rev. D
null
10.1103/PhysRevD.86.036010
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Randall Sundrum models provide a possible explanation of (gauge-gravity) hierarchy, whereas discrete symmetry flavor groups yield a possible description of the texture of Standard Model fermion masses. We use both these ingredients to propose a five-dimensional extension of the Standard Model where the mass hierarchy of the four-dimensional effective field theory is obtained only using localizations parameters of order 1. We consider a bulk custodial gauge symmetry group together with an Abelian $Z_4$ group: the model turns out to yield a rather minimal extension of the SM as it only requires two brane Higgs fields to provide the desired Yukawa interactions and the required spontaneous symmetry breaking pattern. In fact, the presence of an extra-dimension allows the use of the Scherk-Schwarz mechanism to contribute to the breaking of the bulk custodial group down to the SM gauge symmetry. Moreover, no right-handed neutrinos are present and neutrino masses are generated radiatively with the help of a bulk charged scalar field that provides the Lepton-number violation. Using experimental inputs from the Global Neutrino Analysis and recent Daya Bay results, a numerical analysis is performed and allowed parameter regions are displayed.
[ { "created": "Fri, 22 Jun 2012 17:32:51 GMT", "version": "v1" }, { "created": "Thu, 23 Aug 2012 03:46:44 GMT", "version": "v2" } ]
2013-05-30
[ [ "Alvarado", "Carlos", "" ], [ "Aranda", "Alfredo", "" ], [ "Corradini", "Olindo", "" ], [ "Rojas", "Alma D.", "" ], [ "Santos-Rodriguez", "Eli", "" ] ]
Randall Sundrum models provide a possible explanation of (gauge-gravity) hierarchy, whereas discrete symmetry flavor groups yield a possible description of the texture of Standard Model fermion masses. We use both these ingredients to propose a five-dimensional extension of the Standard Model where the mass hierarchy of the four-dimensional effective field theory is obtained only using localizations parameters of order 1. We consider a bulk custodial gauge symmetry group together with an Abelian $Z_4$ group: the model turns out to yield a rather minimal extension of the SM as it only requires two brane Higgs fields to provide the desired Yukawa interactions and the required spontaneous symmetry breaking pattern. In fact, the presence of an extra-dimension allows the use of the Scherk-Schwarz mechanism to contribute to the breaking of the bulk custodial group down to the SM gauge symmetry. Moreover, no right-handed neutrinos are present and neutrino masses are generated radiatively with the help of a bulk charged scalar field that provides the Lepton-number violation. Using experimental inputs from the Global Neutrino Analysis and recent Daya Bay results, a numerical analysis is performed and allowed parameter regions are displayed.
2302.04150
Hanqing Zheng
Ye Lu, Chang Chen, Kai-Ge Kang, Guang-you Qin, Han-Qing Zheng
The $X(6900)$ peak could be a molecular state
7pages with 9 figures
null
10.1103/PhysRevD.107.094006
null
hep-ph hep-ex
http://creativecommons.org/publicdomain/zero/1.0/
The analyses of the LHCb data on $X(6900)$ found in di-$J/\psi$ and $J/\psi \psi(3686)$ systems are performed using a momentum-dependent {Flatt\'{e}}-like parameterization. The use of the pole counting rule and spectral density function sum rule give consistent conclusions that $X(6900)$ may not be a molecule of $J/\psi \psi(3686)$. Nevertheless it is still possible that $X(6900)$ be a molecule of higher states, such as $J/\psi\psi(3770)$, $\chi_{c0}\chi_{c2}$, etc.
[ { "created": "Wed, 8 Feb 2023 15:52:02 GMT", "version": "v1" } ]
2023-05-17
[ [ "Lu", "Ye", "" ], [ "Chen", "Chang", "" ], [ "Kang", "Kai-Ge", "" ], [ "Qin", "Guang-you", "" ], [ "Zheng", "Han-Qing", "" ] ]
The analyses of the LHCb data on $X(6900)$ found in di-$J/\psi$ and $J/\psi \psi(3686)$ systems are performed using a momentum-dependent {Flatt\'{e}}-like parameterization. The use of the pole counting rule and spectral density function sum rule give consistent conclusions that $X(6900)$ may not be a molecule of $J/\psi \psi(3686)$. Nevertheless it is still possible that $X(6900)$ be a molecule of higher states, such as $J/\psi\psi(3770)$, $\chi_{c0}\chi_{c2}$, etc.
hep-ph/0008157
Stephen Godfrey
Stephen Godfrey, Pat Kalyniak, Basim Kamal, M.A. Doncheski, and Arnd Leike
Discovery and Identification of W' Bosons in e gamma to nu q +X
17 pages, 9 figures, uses Revtex and epsfig
Phys.Rev.D63:053005,2001
10.1103/PhysRevD.63.053005
null
hep-ph
null
We examine the sensitivity of the process e gamma to nu q +X to W' bosons which arise in various extensions of the standard model. We consider photon spectra from both the Weizsacker Williams process and from a backscattered laser. The process is found to be sensitive to W' masses up to several TeV, depending on the model, the center of mass energy, the integrated luminosity, and assumptions regarding systematic errors. If extra gauge bosons were discovered first in other experiments, the process could also be used to measure W' couplings. This measurement would provide information that could be used to unravel the underlying theory, complementary to measurements at the Large Hadron Collider.
[ { "created": "Tue, 15 Aug 2000 19:28:01 GMT", "version": "v1" } ]
2011-07-19
[ [ "Godfrey", "Stephen", "" ], [ "Kalyniak", "Pat", "" ], [ "Kamal", "Basim", "" ], [ "Doncheski", "M. A.", "" ], [ "Leike", "Arnd", "" ] ]
We examine the sensitivity of the process e gamma to nu q +X to W' bosons which arise in various extensions of the standard model. We consider photon spectra from both the Weizsacker Williams process and from a backscattered laser. The process is found to be sensitive to W' masses up to several TeV, depending on the model, the center of mass energy, the integrated luminosity, and assumptions regarding systematic errors. If extra gauge bosons were discovered first in other experiments, the process could also be used to measure W' couplings. This measurement would provide information that could be used to unravel the underlying theory, complementary to measurements at the Large Hadron Collider.
1303.3348
Daniel Schmeier
Herbi Dreiner, Daniel Schmeier, Jamie Tattersall
Contact Interactions Probe Effective Dark Matter Models at the LHC
6 pages, 3 figures
null
10.1209/0295-5075/102/51001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Effective field theories provide a simple framework for probing possible dark matter (DM) models by reparametrising full interactions into a reduced number of operators with smaller dimensionality in parameter space. In many cases these models have four particle vertices, e.g. qqXX, leading to the pair production of dark matter particles, X, at a hadron collider from initial state quarks, q. In this analysis we show that for many fundamental DM models with s-channel DM couplings to qq-pairs, these effective vertices must also produce quark contact interactions (CI) of the form qqqq. The respective effective couplings are related by the common underlying theory which allows one to translate the upper limits from one coupling to the other. We show that at the LHC, the experimental limits on quark contact interactions give stronger translated limits on the DM coupling than the experimental searches for dark matter pair production.
[ { "created": "Thu, 14 Mar 2013 05:54:07 GMT", "version": "v1" } ]
2015-06-15
[ [ "Dreiner", "Herbi", "" ], [ "Schmeier", "Daniel", "" ], [ "Tattersall", "Jamie", "" ] ]
Effective field theories provide a simple framework for probing possible dark matter (DM) models by reparametrising full interactions into a reduced number of operators with smaller dimensionality in parameter space. In many cases these models have four particle vertices, e.g. qqXX, leading to the pair production of dark matter particles, X, at a hadron collider from initial state quarks, q. In this analysis we show that for many fundamental DM models with s-channel DM couplings to qq-pairs, these effective vertices must also produce quark contact interactions (CI) of the form qqqq. The respective effective couplings are related by the common underlying theory which allows one to translate the upper limits from one coupling to the other. We show that at the LHC, the experimental limits on quark contact interactions give stronger translated limits on the DM coupling than the experimental searches for dark matter pair production.
2307.09941
Giovanni Pierobon
Giovanni Pierobon, Javier Redondo, Ken'ichi Saikawa, Alejandro Vaquero, Guy D. Moore
Miniclusters from axion string simulations
17 pages, 6 figures
null
null
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The properties of axion miniclusters and of the voids between them can have very strong implications for the discovery of axions and the dark matter of the Universe. These properties can be strongly affected by axion dynamics in the early Universe, such as the axion string network and the non-linear dynamics around the QCD phase transition. Recently, improvements in numerical simulation techniques have allowed us to calculate the dark matter axion field from axion strings and QCD effects using different methods: directly with low-tension strings but high resolution, directly with effective high-tension strings, or indirectly by extrapolating an attractor solution. In this work, we study the properties of miniclusters in the different approaches used in the literature. We find that, while there are substantial differences in the mass distribution and internal density profiles, globally there is a similar energy distribution between minicluster halos and voids.
[ { "created": "Wed, 19 Jul 2023 12:34:27 GMT", "version": "v1" } ]
2023-07-20
[ [ "Pierobon", "Giovanni", "" ], [ "Redondo", "Javier", "" ], [ "Saikawa", "Ken'ichi", "" ], [ "Vaquero", "Alejandro", "" ], [ "Moore", "Guy D.", "" ] ]
The properties of axion miniclusters and of the voids between them can have very strong implications for the discovery of axions and the dark matter of the Universe. These properties can be strongly affected by axion dynamics in the early Universe, such as the axion string network and the non-linear dynamics around the QCD phase transition. Recently, improvements in numerical simulation techniques have allowed us to calculate the dark matter axion field from axion strings and QCD effects using different methods: directly with low-tension strings but high resolution, directly with effective high-tension strings, or indirectly by extrapolating an attractor solution. In this work, we study the properties of miniclusters in the different approaches used in the literature. We find that, while there are substantial differences in the mass distribution and internal density profiles, globally there is a similar energy distribution between minicluster halos and voids.
hep-ph/0411051
Bennie F. L. Ward
B.F.L. Ward (1), C. Glosser (2), S. Jadach (3,4), W. Placzek (5), M. Skrzypek (3), Z. Was (3), S.A. Yost (1) ((1) Department Department of Physics, Baylor University, Waco, Texas, USA, (2) Department of Physics, Southern Illinois University, Edwardsville, IL, USA, (3) Institute of Nuclear Physics, Krakow, Poland, (4) Theory Division, CERN, Geneva, Switzerland, (5) Institute of Physics, Jagiellonian University, Krakow, Poland)
New Results on Precision Studies of Heavy Vector Boson Physics
5 pages, 2 figures; to appear in Proc. DPF2004
Int.J.Mod.Phys.A20:3258-3262,2005
10.1142/S0217751X05026285
BU-HEPP-04-11
hep-ph
null
We present new results for two important heavy vector boson physics processes: (1), virtual corrections to hard bremsstrahlung which are relevant to precision predictions for the radiative return process in Z boson production at and beyond LEP2 energies ; and, (2), electric charge screening effects in single W production with finite p_T, multiple photon radiation in high energy collider physics processes. In both cases we show that we improve the respective precision tag significantly. Phenomenological implications are discussed.
[ { "created": "Wed, 3 Nov 2004 16:00:39 GMT", "version": "v1" } ]
2011-04-11
[ [ "Ward", "B. F. L.", "" ], [ "Glosser", "C.", "" ], [ "Jadach", "S.", "" ], [ "Placzek", "W.", "" ], [ "Skrzypek", "M.", "" ], [ "Was", "Z.", "" ], [ "Yost", "S. A.", "" ] ]
We present new results for two important heavy vector boson physics processes: (1), virtual corrections to hard bremsstrahlung which are relevant to precision predictions for the radiative return process in Z boson production at and beyond LEP2 energies ; and, (2), electric charge screening effects in single W production with finite p_T, multiple photon radiation in high energy collider physics processes. In both cases we show that we improve the respective precision tag significantly. Phenomenological implications are discussed.
1511.00790
Guang-You Qin
Guang-You Qin and Xin-Nian Wang
Jet quenching in high-energy heavy-ion collisions
review for QGP5, 68 pages, 34 figures
null
10.1142/S0218301315300143
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Jet quenching in high-energy heavy-ion collisions can be used to probe properties of hot and dense quark-gluon plasma. We provide a brief introduction to the concept and framework for the study of jet quenching. Different approaches and implementation of multiple scattering and parton energy loss are discussed. Recent progresses in the theoretical and phenomenological studies of jet quenching in heavy-ion collisions at RHIC and LHC are reviewed.
[ { "created": "Tue, 3 Nov 2015 06:34:16 GMT", "version": "v1" }, { "created": "Tue, 10 Nov 2015 09:30:23 GMT", "version": "v2" } ]
2015-12-09
[ [ "Qin", "Guang-You", "" ], [ "Wang", "Xin-Nian", "" ] ]
Jet quenching in high-energy heavy-ion collisions can be used to probe properties of hot and dense quark-gluon plasma. We provide a brief introduction to the concept and framework for the study of jet quenching. Different approaches and implementation of multiple scattering and parton energy loss are discussed. Recent progresses in the theoretical and phenomenological studies of jet quenching in heavy-ion collisions at RHIC and LHC are reviewed.
hep-ph/9907253
Victor B. Semikoz
V.B. Semikoz, A.A. Bykov, V.Yu. Popov, A.I. Rez, D.D. Sokoloff
Neutrino Spin-Flavor Conversions and Electron Antineutrino emission from the Sun with Random Magnetic Field
6 pages, LaTex file + 1 EPS figure, contribution to the Proceedings of the International Workshop on Particles in Astrophysics and Cosmology, Valencia (Spain), May 3-8, 1999
Nucl.Phys.Proc.Suppl. 81 (2000) 124-129
10.1016/S0920-5632(99)00867-1
null
hep-ph
null
The magnetic field in the solar convective zone has a random small-scale component with the r.m.s. value substancially exceeding the strength of a regular large-scale field. For two Majorana neutrino flavors and two helicities in the presence of a neutrino transition magnetic moment and nonzero neutrino mixing we analize the displacement of the allowed (Delta m^2 - sin^2 2theta)-parameter region reconciled for all Underground experiments with solar neutrinos in dependence on the r.m.s. magnetic field value b. In contrary with the RSFP scenario with a regular large-scale magnetic field, we find an effective production of electron antineutrinos in the Sun even for small neutrino mixing through the cascade conversions like nu_eL -> \bar{nu}_muR -> \bar{nu}_eR. It was found that usual SMA and LMA MSW parameter regions maybe forbidden while opening LOW MSW as the allowed one from the non-observation of \bar{nu}_eR in the SK experiment if random magnetic fields have strengths b > 100 kG and correlation lengths shorter than L_0 < 1000 km.
[ { "created": "Tue, 6 Jul 1999 14:43:36 GMT", "version": "v1" } ]
2009-10-31
[ [ "Semikoz", "V. B.", "" ], [ "Bykov", "A. A.", "" ], [ "Popov", "V. Yu.", "" ], [ "Rez", "A. I.", "" ], [ "Sokoloff", "D. D.", "" ] ]
The magnetic field in the solar convective zone has a random small-scale component with the r.m.s. value substancially exceeding the strength of a regular large-scale field. For two Majorana neutrino flavors and two helicities in the presence of a neutrino transition magnetic moment and nonzero neutrino mixing we analize the displacement of the allowed (Delta m^2 - sin^2 2theta)-parameter region reconciled for all Underground experiments with solar neutrinos in dependence on the r.m.s. magnetic field value b. In contrary with the RSFP scenario with a regular large-scale magnetic field, we find an effective production of electron antineutrinos in the Sun even for small neutrino mixing through the cascade conversions like nu_eL -> \bar{nu}_muR -> \bar{nu}_eR. It was found that usual SMA and LMA MSW parameter regions maybe forbidden while opening LOW MSW as the allowed one from the non-observation of \bar{nu}_eR in the SK experiment if random magnetic fields have strengths b > 100 kG and correlation lengths shorter than L_0 < 1000 km.
1912.11733
David d'Enterria
David d'Enterria, Andres Poldaru
Strong coupling $\alpha_s(m_Z)$ extraction from a combined NNLO analysis of inclusive electroweak boson cross sections at hadron colliders
31 pages, 26 figures. Additional cross-checks and clarifications added. Results unchanged. Version to appear in JHEP
null
10.1007/JHEP06(2020)016
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The inclusive cross sections of W$^+$, W$^-$, and Z boson production from 34 different measurements performed in proton-(anti)proton collisions at center-of-mass energies $\sqrt{s}$ = 1.8--13 TeV, are compared to perturbative QCD calculations at next-to-next-to-leading-order (NNLO) accuracy with four sets of parton distributions functions (CT14, HERAPDF2.0, MMHT14, and NNPDF3.0 PDFs) and varying values of the strong coupling constant at the Z mass pole, $\alpha_s(m_Z)$. The data-theory agreement is good within the experimental and theoretical uncertainties, with the CT14 and MMHT14 parton densities providing the most overall consistent description of all cross section data. A value of $\alpha_s(m_Z) = 0.1188^{+0.0019}_{-0.0013}$ is extracted from a combined fit of the 28 experimental LHC measurements to the corresponding NNLO theoretical predictions obtained with the MMHT14 PDF set, which provides the most robust and stable QCD coupling extraction of this analysis.
[ { "created": "Thu, 26 Dec 2019 00:27:13 GMT", "version": "v1" }, { "created": "Sun, 24 May 2020 23:37:08 GMT", "version": "v2" } ]
2020-06-04
[ [ "d'Enterria", "David", "" ], [ "Poldaru", "Andres", "" ] ]
The inclusive cross sections of W$^+$, W$^-$, and Z boson production from 34 different measurements performed in proton-(anti)proton collisions at center-of-mass energies $\sqrt{s}$ = 1.8--13 TeV, are compared to perturbative QCD calculations at next-to-next-to-leading-order (NNLO) accuracy with four sets of parton distributions functions (CT14, HERAPDF2.0, MMHT14, and NNPDF3.0 PDFs) and varying values of the strong coupling constant at the Z mass pole, $\alpha_s(m_Z)$. The data-theory agreement is good within the experimental and theoretical uncertainties, with the CT14 and MMHT14 parton densities providing the most overall consistent description of all cross section data. A value of $\alpha_s(m_Z) = 0.1188^{+0.0019}_{-0.0013}$ is extracted from a combined fit of the 28 experimental LHC measurements to the corresponding NNLO theoretical predictions obtained with the MMHT14 PDF set, which provides the most robust and stable QCD coupling extraction of this analysis.
hep-ph/0001277
Miroslav Pardy
Miroslav Pardy
The two-body electromagnetic pulsar
9 p
null
null
MUNI 2000-1
hep-ph
null
The power spectrum formula of the synchrotron radiation generated by the electron and positron moving at the opposite angular velocities in homogenous magnetic field is derived in the Schwinger version of quantum field theory. The asymptotical form of this formula is found. It is surprising that the spectrum depends periodically on radiation frequency omega which means that the system composed from electron, positron and magnetic field forms the two-body electromagnetic pulsar.
[ { "created": "Thu, 27 Jan 2000 11:32:11 GMT", "version": "v1" } ]
2007-05-23
[ [ "Pardy", "Miroslav", "" ] ]
The power spectrum formula of the synchrotron radiation generated by the electron and positron moving at the opposite angular velocities in homogenous magnetic field is derived in the Schwinger version of quantum field theory. The asymptotical form of this formula is found. It is surprising that the spectrum depends periodically on radiation frequency omega which means that the system composed from electron, positron and magnetic field forms the two-body electromagnetic pulsar.
hep-ph/9807262
Brian W. Harris
Howard Baer, B. W. Harris (Florida State U.), Xerxes Tata (U. Hawaii)
The Reach of CERN LEP2 and Fermilab Tevatron Upgrades for Higgs Bosons in Supersymmetric Models
12 pages + 7 figures. Uses REVTEX and epsf macros. Several references added, stated value of A-parameters corrected, note added reguarding sgn(mu) dependence in MSSM case. To appear in Physical Review D
Phys.Rev. D59 (1999) 015003
10.1103/PhysRevD.59.015003
FSU-HEP-980626, UH-511-908-98
hep-ph
null
Luminosity upgrades of the Fermilab Tevatron pbar-p collider have been shown to allow experimental detection of a Standard Model (SM) Higgs boson up to $m_{H_{SM}}\sim 120$ GeV via $WH_{SM} \to \ell\nu b\bar{b}$ events. This limit nearly saturates the parameter space for many models of weak scale supersymmetry (SUSY) with a minimal particle content. It is therefore interesting to examine the SUSY Higgs reach of future Tevatron experiments. Contours are presented of Higgs boson reach for CERN LEP2 and Tevatron luminosity upgrades for three models of weak scale SUSY: the Minimal Supersymmetric Standard Model (MSSM), the minimal Supergravity model (mSUGRA) and a simple Gauge Mediated SUSY Breaking Model (GMSB). In each case we find a substantial gain in reach at the Tevatron with integrated luminosity increasing from 10 fb^{-1} to 25-30 fb^{-1}. With the larger integrated luminosity, a Higgs search at the Tevatron should be able to probe essentially the entire parameter space of these models. While a discovery would be very exciting, a negative result would severely constrain our ideas about how weak scale supersymmetry is realized.
[ { "created": "Mon, 6 Jul 1998 18:03:53 GMT", "version": "v1" }, { "created": "Wed, 30 Sep 1998 18:46:13 GMT", "version": "v2" } ]
2009-10-31
[ [ "Baer", "Howard", "", "Florida State U." ], [ "Harris", "B. W.", "", "Florida State U." ], [ "Tata", "Xerxes", "", "U. Hawaii" ] ]
Luminosity upgrades of the Fermilab Tevatron pbar-p collider have been shown to allow experimental detection of a Standard Model (SM) Higgs boson up to $m_{H_{SM}}\sim 120$ GeV via $WH_{SM} \to \ell\nu b\bar{b}$ events. This limit nearly saturates the parameter space for many models of weak scale supersymmetry (SUSY) with a minimal particle content. It is therefore interesting to examine the SUSY Higgs reach of future Tevatron experiments. Contours are presented of Higgs boson reach for CERN LEP2 and Tevatron luminosity upgrades for three models of weak scale SUSY: the Minimal Supersymmetric Standard Model (MSSM), the minimal Supergravity model (mSUGRA) and a simple Gauge Mediated SUSY Breaking Model (GMSB). In each case we find a substantial gain in reach at the Tevatron with integrated luminosity increasing from 10 fb^{-1} to 25-30 fb^{-1}. With the larger integrated luminosity, a Higgs search at the Tevatron should be able to probe essentially the entire parameter space of these models. While a discovery would be very exciting, a negative result would severely constrain our ideas about how weak scale supersymmetry is realized.
hep-ph/0412401
Joseph Schechter
Samina S. Masood, Salah Nasri, Joseph Schechter
Leptonic CP violation in a two parameter model
12 pages, 1 figure
Phys.Rev. D71 (2005) 093005
10.1103/PhysRevD.71.093005
null
hep-ph
null
We further study the "complementary" Ansatz, Tr$(M_\nu)$=0, for a prediagonal light Majorana type neutrino mass matrix. Previously, this was studied for the CP conserving case and the case where the two Majorana type CP violating phases were present but the Dirac type CP violating phase was neglected. Here we employ a simple geometric algorithm which enables us to "solve" the Ansatz including all three CP violating phases. Specifically, given the known neutrino oscillation data and an assumed two parameter (the third neutrino mass $m_3$ and the Dirac CP phase $\delta$) family of inputs we predict the neutrino masses and Majorana CP phases. Despite the two parameter ambiguity, interesting statements emerge. There is a characteristic pattern of interconnected masses and CP phases. For large $m_3$ the three neutrinos are approximately degenerate. The only possibility for a mass hierarchy is to have $m_3$ smaller than the other two. A hierarchy with $m_3$ largest is not allowed. Small CP violation is possible only near two special values of $m_3$. Also, the neutrinoless double beta decay parameter is approximately bounded as 0.020 eV $<|m_{ee}|<$ 0.185 eV. As a byproduct of looking at physical amplitudes we discuss an alternative parameterization of the lepton mixing matrix which results in simpler formulas. The physical meaning of this parameterization is explained.
[ { "created": "Tue, 28 Dec 2004 21:24:33 GMT", "version": "v1" } ]
2009-11-10
[ [ "Masood", "Samina S.", "" ], [ "Nasri", "Salah", "" ], [ "Schechter", "Joseph", "" ] ]
We further study the "complementary" Ansatz, Tr$(M_\nu)$=0, for a prediagonal light Majorana type neutrino mass matrix. Previously, this was studied for the CP conserving case and the case where the two Majorana type CP violating phases were present but the Dirac type CP violating phase was neglected. Here we employ a simple geometric algorithm which enables us to "solve" the Ansatz including all three CP violating phases. Specifically, given the known neutrino oscillation data and an assumed two parameter (the third neutrino mass $m_3$ and the Dirac CP phase $\delta$) family of inputs we predict the neutrino masses and Majorana CP phases. Despite the two parameter ambiguity, interesting statements emerge. There is a characteristic pattern of interconnected masses and CP phases. For large $m_3$ the three neutrinos are approximately degenerate. The only possibility for a mass hierarchy is to have $m_3$ smaller than the other two. A hierarchy with $m_3$ largest is not allowed. Small CP violation is possible only near two special values of $m_3$. Also, the neutrinoless double beta decay parameter is approximately bounded as 0.020 eV $<|m_{ee}|<$ 0.185 eV. As a byproduct of looking at physical amplitudes we discuss an alternative parameterization of the lepton mixing matrix which results in simpler formulas. The physical meaning of this parameterization is explained.
1308.0545
Guido Altarelli
Guido Altarelli
The Higgs: so simple yet so unnatural
17 pages, 4 figures. Talk given at the Nobel Symposium on LHC results, Krusenberg, Sweden, 3-17 May 2013. Typos corrected, References added
null
10.1088/0031-8949/2013/T158/014011
RM3-TH/13- 7; CERN-PH-TH/2013-182
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a concise outlook of particle physics after the first LHC results at 7-8 TeV. The discovery of the Higgs boson at 126 GeV will remain as one of the major physics discoveries of our time. But also the surprising absence of any signals of new physics, if confirmed in the continuation of the LHC experiments, is going to drastically change our vision of the field. At present the indication is that Nature does not too much care about our notion of naturalness. Still the argument for naturalness is a solid one and we are facing a puzzling situation. We review the established facts so far and present a tentative assessment of the open problems.
[ { "created": "Fri, 2 Aug 2013 15:54:24 GMT", "version": "v1" }, { "created": "Wed, 4 Dec 2013 16:38:21 GMT", "version": "v2" } ]
2015-06-16
[ [ "Altarelli", "Guido", "" ] ]
We present a concise outlook of particle physics after the first LHC results at 7-8 TeV. The discovery of the Higgs boson at 126 GeV will remain as one of the major physics discoveries of our time. But also the surprising absence of any signals of new physics, if confirmed in the continuation of the LHC experiments, is going to drastically change our vision of the field. At present the indication is that Nature does not too much care about our notion of naturalness. Still the argument for naturalness is a solid one and we are facing a puzzling situation. We review the established facts so far and present a tentative assessment of the open problems.
hep-ph/9911274
Marco Aurelio Diaz
Marco Aurelio Diaz
Stop Decays with R-Parity Violation and the Neutrino Mass
5 pages, 8 figures. Talk given at the International Workshop on Particles in Astrophysics and Cosmology: From Theory to Observation, Valencia, Spain, May 3-8, 1999
Nucl.Phys.Proc.Suppl. 81 (2000) 259-263
null
UCCHEP/5-99, FSU-HEP-991020
hep-ph
null
The atmospheric and solar neutrino problems can be explained in a supersymmetric scenario where R-parity is broken bilinearly. Within this context we explore the decays of the top squark. We find that the Rp violating decay $\tilde t_1 -> b \tau$ can easily dominate over the Rp conserving decay $\tilde t_1 -> c \tilde\chi^0_1$ and sometimes also over the decay $\tilde t_1 -> b \tilde\chi^+_1$. We study the implications of non-universal boundary conditions at the GUT scale.
[ { "created": "Mon, 8 Nov 1999 20:12:54 GMT", "version": "v1" } ]
2007-05-23
[ [ "Diaz", "Marco Aurelio", "" ] ]
The atmospheric and solar neutrino problems can be explained in a supersymmetric scenario where R-parity is broken bilinearly. Within this context we explore the decays of the top squark. We find that the Rp violating decay $\tilde t_1 -> b \tau$ can easily dominate over the Rp conserving decay $\tilde t_1 -> c \tilde\chi^0_1$ and sometimes also over the decay $\tilde t_1 -> b \tilde\chi^+_1$. We study the implications of non-universal boundary conditions at the GUT scale.
1510.05379
Roman Nevzorov
C. Froggatt, R. Nevzorov, H. B. Nielsen, A. Thomas
On the smallness of the cosmological constant in SUGRA models with Planck scale SUSY breaking and degenerate vacua
Parallel talk at EPS-HEP 2015, Vienna, Austria, July 2015, 6 pages. arXiv admin note: text overlap with arXiv:1410.6620
null
null
ADP-15-38-T940
hep-ph astro-ph.CO gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We argue that the exact degeneracy of vacua in N=1 supergravity can shed light on the smallness of the cosmological constant. The presence of such vacua, which are degenerate to very high accuracy, may also result in small values of the quartic Higgs coupling and its beta function at the Planck scale in the phase in which we live.
[ { "created": "Mon, 19 Oct 2015 08:23:30 GMT", "version": "v1" } ]
2015-10-20
[ [ "Froggatt", "C.", "" ], [ "Nevzorov", "R.", "" ], [ "Nielsen", "H. B.", "" ], [ "Thomas", "A.", "" ] ]
We argue that the exact degeneracy of vacua in N=1 supergravity can shed light on the smallness of the cosmological constant. The presence of such vacua, which are degenerate to very high accuracy, may also result in small values of the quartic Higgs coupling and its beta function at the Planck scale in the phase in which we live.
1302.3164
Jan Winter
Jan Winter, Peter Z. Skands, Bryan R. Webber
Monte Carlo event generators & the top quark forward--backward asymmetry
6 pages, 10 figures, contribution to the proceedings of the HCP symposium 2012 in Kyoto, Japan
null
10.1051/epjconf/20134917001
Cavendish-HEP-13/03, CERN-PH-TH/2013-026, MPP-2013-31
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The leading-order accurate description of top quark pair production, as usually employed in standard Monte Carlo event generators, gives no rise to the generation of a forward--backward asymmetry. Yet, non-negligible -- differential as well as inclusive -- asymmetries may be produced if coherent parton showering is used in the hadroproduction of top quark pairs. In this contribution we summarize the outcome of our study of this effect. We present a short comparison of different parton shower implementations and briefly comment on the phenomenology of the colour coherence effect at the Tevatron.
[ { "created": "Wed, 13 Feb 2013 16:59:44 GMT", "version": "v1" } ]
2015-06-15
[ [ "Winter", "Jan", "" ], [ "Skands", "Peter Z.", "" ], [ "Webber", "Bryan R.", "" ] ]
The leading-order accurate description of top quark pair production, as usually employed in standard Monte Carlo event generators, gives no rise to the generation of a forward--backward asymmetry. Yet, non-negligible -- differential as well as inclusive -- asymmetries may be produced if coherent parton showering is used in the hadroproduction of top quark pairs. In this contribution we summarize the outcome of our study of this effect. We present a short comparison of different parton shower implementations and briefly comment on the phenomenology of the colour coherence effect at the Tevatron.
1010.0338
Michal Malinsky
Stefano Bertolini, Luca Di Luzio, Michal Malinsky
The quantum vacuum of the minimal SO(10) GUT
5 pages, 1 figure, proceedings submission for PASCOS'10
null
10.1088/1742-6596/259/1/012098
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We reexamine the longstanding no-go excluding all potentially viable SO(10) -> SU(3)_c x SU(2)_L x U(1)_Y symmetry breaking patterns within the minimal renormalizable non-supersymmetric SO(10) GUT framework featuring the 45-dimensional adjoint representation in the Higgs sector. A simple symmetry argument indicates that quantum effects do change the vacuum structure of the model dramatically. A thorough analysis of the one-loop effective potential reveals that the phenomenologically favoured symmetry breaking chains passing through the SU(4)_C x SU(2)_L x U(1)_R or SU(3)_c x SU(2)_L x SU(2)_R x U(1)_B-L intermediate stages are, indeed, supported at the quantum level. This brings the class of minimal non-supersymmetric SO(10) GUTs back from oblivion, providing a new ground for a potentially realistic model building.
[ { "created": "Sat, 2 Oct 2010 14:28:38 GMT", "version": "v1" } ]
2015-05-20
[ [ "Bertolini", "Stefano", "" ], [ "Di Luzio", "Luca", "" ], [ "Malinsky", "Michal", "" ] ]
We reexamine the longstanding no-go excluding all potentially viable SO(10) -> SU(3)_c x SU(2)_L x U(1)_Y symmetry breaking patterns within the minimal renormalizable non-supersymmetric SO(10) GUT framework featuring the 45-dimensional adjoint representation in the Higgs sector. A simple symmetry argument indicates that quantum effects do change the vacuum structure of the model dramatically. A thorough analysis of the one-loop effective potential reveals that the phenomenologically favoured symmetry breaking chains passing through the SU(4)_C x SU(2)_L x U(1)_R or SU(3)_c x SU(2)_L x SU(2)_R x U(1)_B-L intermediate stages are, indeed, supported at the quantum level. This brings the class of minimal non-supersymmetric SO(10) GUTs back from oblivion, providing a new ground for a potentially realistic model building.
hep-ph/0008085
Andre De Gouvea
A. de Gouvea, S. Lola, and K. Tobe (CERN-TH)
Lepton Flavour Violation In Supersymmetric Models with Trilinear R-parity Violation
34 pages, 6 figures
Phys.Rev. D63 (2001) 035004
10.1103/PhysRevD.63.035004
CERN-TH/2000-241
hep-ph
null
Supersymmetry with R-parity violation (RPV) provides an interesting framework for naturally accommodating small neutrino masses. Within this framework, we discuss the lepton-flavour violating (LFV) processes mu -> e gamma, mu -> eee, and mu -> e conversion in nuclei. We make a detailed study of the observables related to LFV in different RPV models, and compare them to the expectations of R-conserving supersymmetry with heavy right-handed neutrinos. We show that the predictions are vastly different and uniquely characterise each model, thus providing a powerful framework for experimentally distinguishing between different theories of LFV. Besides the obvious possibility of amplified tree-level generation of mu -> eee and mu -> e conversion in nuclei, we find that even in the case where these processes arise at the one-loop level, their rates are comparable to that of mu -> e gamma, in clear contrast to the predictions of R-conserving models. We conclude that in order to distinguish between the different models, such a combined study of all the LFV processes is necessary, and that measuring P-odd asymmetries in polarised mu -> eee can play a decisive role. We also comment on the intriguing possibility of RPV models yielding a large T-odd asymmetry in the decay of polarised mu -> eee.
[ { "created": "Wed, 9 Aug 2000 18:00:15 GMT", "version": "v1" } ]
2009-10-31
[ [ "de Gouvea", "A.", "", "CERN-TH" ], [ "Lola", "S.", "", "CERN-TH" ], [ "Tobe", "K.", "", "CERN-TH" ] ]
Supersymmetry with R-parity violation (RPV) provides an interesting framework for naturally accommodating small neutrino masses. Within this framework, we discuss the lepton-flavour violating (LFV) processes mu -> e gamma, mu -> eee, and mu -> e conversion in nuclei. We make a detailed study of the observables related to LFV in different RPV models, and compare them to the expectations of R-conserving supersymmetry with heavy right-handed neutrinos. We show that the predictions are vastly different and uniquely characterise each model, thus providing a powerful framework for experimentally distinguishing between different theories of LFV. Besides the obvious possibility of amplified tree-level generation of mu -> eee and mu -> e conversion in nuclei, we find that even in the case where these processes arise at the one-loop level, their rates are comparable to that of mu -> e gamma, in clear contrast to the predictions of R-conserving models. We conclude that in order to distinguish between the different models, such a combined study of all the LFV processes is necessary, and that measuring P-odd asymmetries in polarised mu -> eee can play a decisive role. We also comment on the intriguing possibility of RPV models yielding a large T-odd asymmetry in the decay of polarised mu -> eee.
2007.04947
Somnath Kar
Mitali Mondal, Joyati Mondal, Somnath Kar, Argha Deb, and Premomoy Ghosh
Forward-backward multiplicity and momentum correlations in $pp$ collisions at LHC energies
11 pages, 15 figures
Phys. Rev. D 102, 014033 (2020)
10.1103/PhysRevD.102.014033
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Charged-particle multiplicity and summed values of the transverse momentum ($p_{\rm T}$) have been utilized for estimating forward-backward (FB) correlation strength for EPOS3 simulated proton-proton ($pp$) events with and without hydrodynamical evolution of particles at center-of-mass energies $\sqrt{s}$ = 0.9, 2.76, and 7 TeV for different pseudorapidity window width ($\delta\eta$) and gap ($\eta_{gap}$) between the FB windows. We have studied the variation of FB correlation strength with $\eta_{gap}$, $\delta\eta$, $\sqrt{s}$, $p_{\rm T}$ cuts and multiplicity classes. Results are compared with the corresponding ALICE and ATLAS data. EPOS3 model qualitatively reproduces the overall variation of correlation strength of the LHC data. However, quantitative agreement is better for $pp$ events, generated using EPOS3 with hydrodynamical evolution of particles, with ATLAS data.
[ { "created": "Thu, 9 Jul 2020 17:20:30 GMT", "version": "v1" } ]
2020-07-29
[ [ "Mondal", "Mitali", "" ], [ "Mondal", "Joyati", "" ], [ "Kar", "Somnath", "" ], [ "Deb", "Argha", "" ], [ "Ghosh", "Premomoy", "" ] ]
Charged-particle multiplicity and summed values of the transverse momentum ($p_{\rm T}$) have been utilized for estimating forward-backward (FB) correlation strength for EPOS3 simulated proton-proton ($pp$) events with and without hydrodynamical evolution of particles at center-of-mass energies $\sqrt{s}$ = 0.9, 2.76, and 7 TeV for different pseudorapidity window width ($\delta\eta$) and gap ($\eta_{gap}$) between the FB windows. We have studied the variation of FB correlation strength with $\eta_{gap}$, $\delta\eta$, $\sqrt{s}$, $p_{\rm T}$ cuts and multiplicity classes. Results are compared with the corresponding ALICE and ATLAS data. EPOS3 model qualitatively reproduces the overall variation of correlation strength of the LHC data. However, quantitative agreement is better for $pp$ events, generated using EPOS3 with hydrodynamical evolution of particles, with ATLAS data.