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1010.2394
Abhijit Bhattacharyya Prof.
Abhijit Bhattacharyya, Paramita Deb, Anirban Lahiri and Rajarshi Ray
Correlation between conserved charges in PNJL Model with multi-quark interactions
null
Phys.Rev.D83:014011,2011
10.1103/PhysRevD.83.014011
null
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a study of correlations among conserved charges like baryon number, electric charge and strangeness in the framework of 2+1 flavor Polyakov loop extended Nambu-Jona-Lasinio model at vanishing chemical potentials, up to fourth order. Correlations up to second order have been measured in Lattice QCD which compares well with our estimates given the inherent difference in the pion masses in the two systems. Possible physical implications of these correlations and their importance in understanding the matter obtained in heavy-ion collisions are discussed. We also present comparison of the results with the commonly used unbound effective potential in the quark sector of this model.
[ { "created": "Tue, 12 Oct 2010 13:59:25 GMT", "version": "v1" }, { "created": "Tue, 30 Nov 2010 11:54:05 GMT", "version": "v2" }, { "created": "Thu, 27 Jan 2011 08:58:58 GMT", "version": "v3" } ]
2015-03-17
[ [ "Bhattacharyya", "Abhijit", "" ], [ "Deb", "Paramita", "" ], [ "Lahiri", "Anirban", "" ], [ "Ray", "Rajarshi", "" ] ]
We present a study of correlations among conserved charges like baryon number, electric charge and strangeness in the framework of 2+1 flavor Polyakov loop extended Nambu-Jona-Lasinio model at vanishing chemical potentials, up to fourth order. Correlations up to second order have been measured in Lattice QCD which compares well with our estimates given the inherent difference in the pion masses in the two systems. Possible physical implications of these correlations and their importance in understanding the matter obtained in heavy-ion collisions are discussed. We also present comparison of the results with the commonly used unbound effective potential in the quark sector of this model.
1607.03030
Marco Sekulla
C. Fleper, W. Kilian, J. Reuter, M. Sekulla
Scattering of W and Z Bosons at High-Energy Lepton Colliders
31 pages, 14 figures
null
10.1140/epjc/s10052-017-4656-5
DESY 16-098, SI-HEP-2016-21, KA-TP-11-2016
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We present a new study of quasi-elastic $W$ and $Z$ scattering processes in high-energy $e^+e^-$ collisions, based on and extrapolating the low-energy effective theory which extends the Standard Model with a 125 GeV Higgs boson. Besides parameterizing deviations in terms of the dimension-8 operators that arise in the effective theory, we also study simplified models of new physics in $W/Z$ scattering in terms of scalar and tensor resonance multiplets. The high-energy asymptotics of all models is regulated by a universal unitarization procedure. This enables us to provide benchmark scenarios which can be meaningfully evaluated off-shell and in exclusive event samples, and to determine the sensitivity of an $e^+e^-$ collider to the model parameters. We analyze the longitudinal vector boson scattering modes, where we optimize the cuts for the fiducial cross section for different collider scenarios. Here, we choose energy stages of 1.0, 1.4 and 3 TeV, as motivated by the extendability of the ILC project and the staging scenario of the CLIC project.
[ { "created": "Mon, 11 Jul 2016 16:53:44 GMT", "version": "v1" } ]
2017-03-08
[ [ "Fleper", "C.", "" ], [ "Kilian", "W.", "" ], [ "Reuter", "J.", "" ], [ "Sekulla", "M.", "" ] ]
We present a new study of quasi-elastic $W$ and $Z$ scattering processes in high-energy $e^+e^-$ collisions, based on and extrapolating the low-energy effective theory which extends the Standard Model with a 125 GeV Higgs boson. Besides parameterizing deviations in terms of the dimension-8 operators that arise in the effective theory, we also study simplified models of new physics in $W/Z$ scattering in terms of scalar and tensor resonance multiplets. The high-energy asymptotics of all models is regulated by a universal unitarization procedure. This enables us to provide benchmark scenarios which can be meaningfully evaluated off-shell and in exclusive event samples, and to determine the sensitivity of an $e^+e^-$ collider to the model parameters. We analyze the longitudinal vector boson scattering modes, where we optimize the cuts for the fiducial cross section for different collider scenarios. Here, we choose energy stages of 1.0, 1.4 and 3 TeV, as motivated by the extendability of the ILC project and the staging scenario of the CLIC project.
hep-ph/9804339
Shaouly Bar-Shalom
S. Bar-Shalom, G. Eilam and A. Soni
R-parity violation, sneutrino mixing phenomena and CP-violation in p \bar p -> sneutrino -> l^+ l^- + X
27 pages, plain latex, 5 figures embadded in the text using epsfig. Final version as will appear in Phys. Rev. D. Main revisions made: updated and added references, additions to the discussion of spin-asymmetries in section 3
Phys.Rev. D59 (1999) 055012
10.1103/PhysRevD.59.055012
UCRHEP-T221, BNL-HET-98/16
hep-ph
null
The sneutrino resonance reactions p \bar p -> sneutrino -> l^+ l^- +X, for l=e,\mu,\tau, in the MSSM without R-parity are considered. We perform a cross-section analysis and show that present limits on some products of R-parity violating couplings in the sneutrino sector can be significantly improved in future upgraded Fermilab Tevatron runs. Furthermore, we introduce CP-violating and CP-conserving \tau-spin asymmetries which are generated already at the TREE-LEVEL in the reaction p \bar p -> sneutrino -> \tau^+ \tau^- +X if there is muon-sneutrino - \bar muon-sneutrino mixing and that vanish in the SM. We find, for example, that for muon-sneutrino masses in the range 150 GeV < m_{muon-sneutrino} < 450 GeV, these spin asymmetries reach ~ 20 - 30% and ~ 10% for mass splitting between the muon-sneutrino CP-odd and CP-even states at the level of \Delta m ~ \Gamma and \Delta m ~ \Gamma/4, respectively, where \Gamma is the muon-sneutrino width. Both the CP-violating and the CP-conserving spin asymmetries should be detectable in future Tevatron runs even for a heavy sneutrino with a mass < 500 GeV. If detected, such asymmetries - being proportional to the mass splitting between the CP-even and CP-odd sneutrino states - may serve as a strong indication for the existence of the sneutrino mixing phenomenon.
[ { "created": "Tue, 21 Apr 1998 00:19:43 GMT", "version": "v1" }, { "created": "Thu, 31 Dec 1998 18:44:28 GMT", "version": "v2" } ]
2009-10-31
[ [ "Bar-Shalom", "S.", "" ], [ "Eilam", "G.", "" ], [ "Soni", "A.", "" ] ]
The sneutrino resonance reactions p \bar p -> sneutrino -> l^+ l^- +X, for l=e,\mu,\tau, in the MSSM without R-parity are considered. We perform a cross-section analysis and show that present limits on some products of R-parity violating couplings in the sneutrino sector can be significantly improved in future upgraded Fermilab Tevatron runs. Furthermore, we introduce CP-violating and CP-conserving \tau-spin asymmetries which are generated already at the TREE-LEVEL in the reaction p \bar p -> sneutrino -> \tau^+ \tau^- +X if there is muon-sneutrino - \bar muon-sneutrino mixing and that vanish in the SM. We find, for example, that for muon-sneutrino masses in the range 150 GeV < m_{muon-sneutrino} < 450 GeV, these spin asymmetries reach ~ 20 - 30% and ~ 10% for mass splitting between the muon-sneutrino CP-odd and CP-even states at the level of \Delta m ~ \Gamma and \Delta m ~ \Gamma/4, respectively, where \Gamma is the muon-sneutrino width. Both the CP-violating and the CP-conserving spin asymmetries should be detectable in future Tevatron runs even for a heavy sneutrino with a mass < 500 GeV. If detected, such asymmetries - being proportional to the mass splitting between the CP-even and CP-odd sneutrino states - may serve as a strong indication for the existence of the sneutrino mixing phenomenon.
hep-ph/9703402
A. D. Martin
V.S.Fadin, V.A.Khoze and A.D.Martin
Higgs studies in polarized gamma-gamma collisions
36 pages of Latex file + 10 psfiles with figures
Phys.Rev. D56 (1997) 484-503
10.1103/PhysRevD.56.484
DTP/97/14
hep-ph
null
The study of an intermediate mass Higgs boson, via the process gamma-gamma -> H -> bbbar from an initiallypolarized J_z = 0 state, has been advocated as an important feasible goal of a future photon linear collider. The crucial argument was the m_b^2/s suppression of the background process gamma-gamma (J_z = 0) -> bbbar. We critically review the contribution of the radiative background processes (in which the m_b^2/s suppression is absent) to the quasi-two-jet-like events with at least one, but preferably two, tagged energetic b jets. Within a complete study of the radiative processes, we find that a sizeable background contribution can come from the helicity-violating gamma-gamma (J_z = 0) -> bbbar process accompanied by soft gluon emission. These latter radiative corrections contain a new type of double logarithmic (DL) terms. We clarify the physical nature of these novel DL corrections. Despite the fact that the one-loop DL terms are comparable or even larger than the Born term, fortunately we find that the calculation of the cross section in the two-loop approximation is sufficient for a reliable evaluation of the background to the Higgs signal.
[ { "created": "Mon, 24 Mar 1997 18:05:06 GMT", "version": "v1" } ]
2009-10-30
[ [ "Fadin", "V. S.", "" ], [ "Khoze", "V. A.", "" ], [ "Martin", "A. D.", "" ] ]
The study of an intermediate mass Higgs boson, via the process gamma-gamma -> H -> bbbar from an initiallypolarized J_z = 0 state, has been advocated as an important feasible goal of a future photon linear collider. The crucial argument was the m_b^2/s suppression of the background process gamma-gamma (J_z = 0) -> bbbar. We critically review the contribution of the radiative background processes (in which the m_b^2/s suppression is absent) to the quasi-two-jet-like events with at least one, but preferably two, tagged energetic b jets. Within a complete study of the radiative processes, we find that a sizeable background contribution can come from the helicity-violating gamma-gamma (J_z = 0) -> bbbar process accompanied by soft gluon emission. These latter radiative corrections contain a new type of double logarithmic (DL) terms. We clarify the physical nature of these novel DL corrections. Despite the fact that the one-loop DL terms are comparable or even larger than the Born term, fortunately we find that the calculation of the cross section in the two-loop approximation is sufficient for a reliable evaluation of the background to the Higgs signal.
2004.05195
Michael Strickland
Dekrayat Almaalol, Aleksi Kurkela, and Michael Strickland
Non-equilibrium attractor in high-temperature QCD plasmas
10 pages 5 figures
Phys. Rev. Lett. 125, 122302 (2020)
10.1103/PhysRevLett.125.122302
CERN-TH-2020-059
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We establish the existence of a far-from-equilibrium attractor in weakly-coupled gauge theory undergoing one-dimensional Bjorken expansion. We demonstrate that the resulting far-from-equilibrium evolution is insensitive to certain features of the initial condition, including both the initial momentum-space anisotropy and initial occupancy. We find that this insensitivity extends beyond the energy-momentum tensor to the detailed form of the one-particle distribution function. Based on our results, we assess different procedures for reconstructing the full one-particle distribution function from the energy-momentum tensor along the attractor and discuss implications for the freeze-out procedure used in the phenomenological analysis of ultra-relativistic nuclear collisions.
[ { "created": "Fri, 10 Apr 2020 18:26:37 GMT", "version": "v1" } ]
2020-09-23
[ [ "Almaalol", "Dekrayat", "" ], [ "Kurkela", "Aleksi", "" ], [ "Strickland", "Michael", "" ] ]
We establish the existence of a far-from-equilibrium attractor in weakly-coupled gauge theory undergoing one-dimensional Bjorken expansion. We demonstrate that the resulting far-from-equilibrium evolution is insensitive to certain features of the initial condition, including both the initial momentum-space anisotropy and initial occupancy. We find that this insensitivity extends beyond the energy-momentum tensor to the detailed form of the one-particle distribution function. Based on our results, we assess different procedures for reconstructing the full one-particle distribution function from the energy-momentum tensor along the attractor and discuss implications for the freeze-out procedure used in the phenomenological analysis of ultra-relativistic nuclear collisions.
hep-ph/9607484
Aneesh Manohar
Aneesh V. Manohar
QCD from a Large N Perspective
14 pages, 4 eps figures. (Plenary Talk at PANIC 96)
null
null
UCSD/PTH 96-21
hep-ph nucl-th
null
The 1/N expansion of QCD can be used to calculate properties of nucleons and Delta baryons, such as masses, magnetic moments, and pion couplings. The predictions of the 1/N expansion are in excellent agreement with the experimental data. The 1/N expansion also provides an understanding of the relation between the quark model, the Skyrme model, and QCD. This talk reviews some of the recent developments.
[ { "created": "Wed, 31 Jul 1996 23:32:30 GMT", "version": "v1" } ]
2007-05-23
[ [ "Manohar", "Aneesh V.", "" ] ]
The 1/N expansion of QCD can be used to calculate properties of nucleons and Delta baryons, such as masses, magnetic moments, and pion couplings. The predictions of the 1/N expansion are in excellent agreement with the experimental data. The 1/N expansion also provides an understanding of the relation between the quark model, the Skyrme model, and QCD. This talk reviews some of the recent developments.
hep-ph/9808392
Claudio Parrinello
J.R. Forshaw, J. Papavassiliou, C. Parrinello
The Massive Yang-Mills Model and Diffractive Scattering
38 pages, Latex, with 7 PostScript pictures. Introduction and Section 6 further enlarged, minor typos corrected
Phys.Rev.D59:074008,1999
10.1103/PhysRevD.59.074008
CERN-TH-98-275, MC-TH-98/6, Liverpool LTH 431
hep-ph
null
We argue that the massive Yang-Mills model of Kunimasa and Goto, Slavnov, and Cornwall, in which massive gauge vector bosons are introduced in a gauge-invariant way without resorting to the Higgs mechanism, may be useful for studying diffractive scattering of strongly interacting particles. We perform in this model explicit calculations of S-matrix elements between quark states, at tree level, one loop, and two loops, and discuss issues of renormalisability and unitarity. In particular, it is shown that the S-matrix element for quark scattering is renormalisable at one-loop order and is only logarithmically non-renormalisable at two loops. The discrepancies in the ultraviolet regime between the one-loop predictions of this model and those of massless QCD are discussed in detail. Also, some of the similarities and differences between the massive Yang-Mills model and theories with a Higgs mechanism are analysed at the level of the S-matrix. Finally, we briefly discuss the high-energy behaviour of the leading-order amplitude for quark-quark elastic scattering in the diffractive region. The above analysis sets up the stage for carrying out a systematic computation of the higher order corrections to the two-gluon exchange model of the Pomeron using massive gluons inside quantum loops.
[ { "created": "Mon, 24 Aug 1998 10:21:02 GMT", "version": "v1" }, { "created": "Mon, 28 Sep 1998 15:12:19 GMT", "version": "v2" }, { "created": "Mon, 8 Feb 1999 14:19:57 GMT", "version": "v3" } ]
2008-11-26
[ [ "Forshaw", "J. R.", "" ], [ "Papavassiliou", "J.", "" ], [ "Parrinello", "C.", "" ] ]
We argue that the massive Yang-Mills model of Kunimasa and Goto, Slavnov, and Cornwall, in which massive gauge vector bosons are introduced in a gauge-invariant way without resorting to the Higgs mechanism, may be useful for studying diffractive scattering of strongly interacting particles. We perform in this model explicit calculations of S-matrix elements between quark states, at tree level, one loop, and two loops, and discuss issues of renormalisability and unitarity. In particular, it is shown that the S-matrix element for quark scattering is renormalisable at one-loop order and is only logarithmically non-renormalisable at two loops. The discrepancies in the ultraviolet regime between the one-loop predictions of this model and those of massless QCD are discussed in detail. Also, some of the similarities and differences between the massive Yang-Mills model and theories with a Higgs mechanism are analysed at the level of the S-matrix. Finally, we briefly discuss the high-energy behaviour of the leading-order amplitude for quark-quark elastic scattering in the diffractive region. The above analysis sets up the stage for carrying out a systematic computation of the higher order corrections to the two-gluon exchange model of the Pomeron using massive gluons inside quantum loops.
2404.04827
Yuxin Liu
Shuailiang Ge, Yuxin Liu, Jing Shu, Yue Zhao
Dark Matter-Induced Low-Mass Gap Black Hole Echoing LVK Observations
8 pages for main text, 7 pages for method, 3 figures
null
null
null
hep-ph astro-ph.HE
http://creativecommons.org/licenses/by/4.0/
The recent detection of gravitational waves from a binary merger involving a potential low-mass gap black hole (LMBH) by LIGO-Virgo-KAGRA (LVK) Collaboration motivates investigations into mechanisms beyond conventional stellar evolution theories to account for their existence. We study a mechanism in which dark matter (DM), through its capture and accumulation inside main sequence stars, induces the formation of black holes within the mass range of $[3, 5]M_\odot$. We examine the distribution of these LMBHs as a function of galaxy halo mass, particularly when paired with neutron stars. This gives a distinct signature that can be tested with future gravitational wave observations. We find that a viable portion of the DM parameter space predicts a merger rate of such binaries consistent with LVK observations.
[ { "created": "Sun, 7 Apr 2024 06:28:02 GMT", "version": "v1" }, { "created": "Mon, 8 Jul 2024 08:57:58 GMT", "version": "v2" } ]
2024-07-09
[ [ "Ge", "Shuailiang", "" ], [ "Liu", "Yuxin", "" ], [ "Shu", "Jing", "" ], [ "Zhao", "Yue", "" ] ]
The recent detection of gravitational waves from a binary merger involving a potential low-mass gap black hole (LMBH) by LIGO-Virgo-KAGRA (LVK) Collaboration motivates investigations into mechanisms beyond conventional stellar evolution theories to account for their existence. We study a mechanism in which dark matter (DM), through its capture and accumulation inside main sequence stars, induces the formation of black holes within the mass range of $[3, 5]M_\odot$. We examine the distribution of these LMBHs as a function of galaxy halo mass, particularly when paired with neutron stars. This gives a distinct signature that can be tested with future gravitational wave observations. We find that a viable portion of the DM parameter space predicts a merger rate of such binaries consistent with LVK observations.
1310.6254
Juan Jose Sanz-Cillero
Juan Jose Sanz-Cillero, Antonio Pich and Ignasi Rosell
Viability of light-Higgs strongly-coupled scenarios
Proceedings of the European Physical Society Conference on High Energy Physics -EPS-HEP2013, 18-24 July 2013, Stockholm (Sweden). 7pages, 3 eps figures
null
null
IFIC/13-77; FTUAM-13-27; IFT-UAM/CSIC-13-103
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Contrary to what is sometimes stated, the current electroweak precision data easily allow for massive composite resonance states at the natural EW scale, i.e., well over the TeV. The oblique parameters S and T are analyzed by means of an effective Lagrangian that implements the $SU(2)_L\otimes SU(2)_R\to SU(2)_{L+R}$ pattern of electroweak symmetry breaking. They are computed at the one-loop level and incorporating the newly discovered Higgs-like boson and possible spin-1 composite resonances. Imposing a proper ultraviolet behaviour is crucial and allows us to determine S and T at next-to-leading order in terms of a few resonance parameters. Electroweak precision data force the vector and axial-vector states to have masses above the TeV scale and suggest that the W+W- and ZZ couplings to the Higgs-like scalar should be close to the Standard Model value. Our findings are generic: they only rely on symmetry principles and soft requirements on the short-distance properties of the underlying strongly-coupled theory, which are widely satisfied in more specific scenarios.
[ { "created": "Wed, 23 Oct 2013 15:09:23 GMT", "version": "v1" } ]
2013-10-24
[ [ "Sanz-Cillero", "Juan Jose", "" ], [ "Pich", "Antonio", "" ], [ "Rosell", "Ignasi", "" ] ]
Contrary to what is sometimes stated, the current electroweak precision data easily allow for massive composite resonance states at the natural EW scale, i.e., well over the TeV. The oblique parameters S and T are analyzed by means of an effective Lagrangian that implements the $SU(2)_L\otimes SU(2)_R\to SU(2)_{L+R}$ pattern of electroweak symmetry breaking. They are computed at the one-loop level and incorporating the newly discovered Higgs-like boson and possible spin-1 composite resonances. Imposing a proper ultraviolet behaviour is crucial and allows us to determine S and T at next-to-leading order in terms of a few resonance parameters. Electroweak precision data force the vector and axial-vector states to have masses above the TeV scale and suggest that the W+W- and ZZ couplings to the Higgs-like scalar should be close to the Standard Model value. Our findings are generic: they only rely on symmetry principles and soft requirements on the short-distance properties of the underlying strongly-coupled theory, which are widely satisfied in more specific scenarios.
hep-ph/0012188
Torbjorn Sjostrand
Torbj\"orn Sj\"ostrand
PYTHIA Status Report
4 pages, to appear in the Proceedings of the Linear Collider Workshop 2000, Fermilab, October 24-28, 2000
null
10.1063/1.1394397
LU TP 00-54
hep-ph
null
Recent improvements in the PYTHIA event generator are summarized: new hard subprocesses, gamma*-gamma* physics, QCD final-state showers, and more.
[ { "created": "Fri, 15 Dec 2000 09:31:15 GMT", "version": "v1" } ]
2009-10-31
[ [ "Sjöstrand", "Torbjörn", "" ] ]
Recent improvements in the PYTHIA event generator are summarized: new hard subprocesses, gamma*-gamma* physics, QCD final-state showers, and more.
0812.1170
Antonio Delgado
A. Delgado, J.R. Espinosa, J.M. No and M. Quir\'os
A Note on Unparticle Decays
11 pages, 4 figures
Phys.Rev.D79:055011,2009
10.1103/PhysRevD.79.055011
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The coupling of an unparticle operator O_U to Standard Model particles opens up the possibility of unparticle decays into standard model fields. We study this issue by analyzing the pole structure (and spectral function) of the unparticle propagator, corrected to account for one-loop polarization effects from virtual SM particles. We find that the propagator of a scalar unparticle (of scaling dimension 1 < d_U < 2) with a mass gap m_g develops an isolated pole, m_p^2-i m_p Gamma_p, with m_p^2 < m_g^2 below the unparticle continuum that extends above m_g (showing that the theory would be unstable without a mass gap). If that pole lies below the threshold for decay into two standard model particles the pole corresponds to a stable unparticle state (and its width Gamma_p is zero). For m_p^2 above threshold the width is non zero and related to the unparticle decay rate into Standard Model particles. This picture is valid for any value of d_U in the considered range.
[ { "created": "Fri, 5 Dec 2008 18:14:44 GMT", "version": "v1" } ]
2010-04-23
[ [ "Delgado", "A.", "" ], [ "Espinosa", "J. R.", "" ], [ "No", "J. M.", "" ], [ "Quirós", "M.", "" ] ]
The coupling of an unparticle operator O_U to Standard Model particles opens up the possibility of unparticle decays into standard model fields. We study this issue by analyzing the pole structure (and spectral function) of the unparticle propagator, corrected to account for one-loop polarization effects from virtual SM particles. We find that the propagator of a scalar unparticle (of scaling dimension 1 < d_U < 2) with a mass gap m_g develops an isolated pole, m_p^2-i m_p Gamma_p, with m_p^2 < m_g^2 below the unparticle continuum that extends above m_g (showing that the theory would be unstable without a mass gap). If that pole lies below the threshold for decay into two standard model particles the pole corresponds to a stable unparticle state (and its width Gamma_p is zero). For m_p^2 above threshold the width is non zero and related to the unparticle decay rate into Standard Model particles. This picture is valid for any value of d_U in the considered range.
0707.2063
Joerg Jaeckel
Joerg Jaeckel and Andreas Ringwald
A Cavity Experiment to Search for Hidden Sector Photons
11 pages, 5 figures
Phys.Lett.B659:509-514,2008
10.1016/j.physletb.2007.11.071
IPPP/07/38; DCPT/07/76; DESY 07-099
hep-ph hep-ex hep-th
null
We propose a cavity experiment to search for low mass extra U(1) gauge bosons with gauge-kinetic mixing with the ordinary photon, so-called paraphotons. The setup consists of two microwave cavities shielded from each other. In one cavity, paraphotons are produced via photon-paraphoton oscillations. The second, resonant, cavity is then driven by the paraphotons that permeate the shielding and reconvert into photons. This setup resembles the classic ``light shining through a wall'' setup. However, the high quality factors achievable for microwave cavities and the good sensitivity of microwave detectors allow for a projected sensitivity for photon-paraphoton mixing of the order of \chi~10^{-12} to 10^{-8}, for paraphotons with masses in the \mu eV to meV range -- exceeding the current laboratory- and astrophysics-based limits by several orders of magnitude. Therefore, this experiment bears significant discovery potential for hidden sector physics.
[ { "created": "Fri, 13 Jul 2007 18:22:21 GMT", "version": "v1" } ]
2008-11-26
[ [ "Jaeckel", "Joerg", "" ], [ "Ringwald", "Andreas", "" ] ]
We propose a cavity experiment to search for low mass extra U(1) gauge bosons with gauge-kinetic mixing with the ordinary photon, so-called paraphotons. The setup consists of two microwave cavities shielded from each other. In one cavity, paraphotons are produced via photon-paraphoton oscillations. The second, resonant, cavity is then driven by the paraphotons that permeate the shielding and reconvert into photons. This setup resembles the classic ``light shining through a wall'' setup. However, the high quality factors achievable for microwave cavities and the good sensitivity of microwave detectors allow for a projected sensitivity for photon-paraphoton mixing of the order of \chi~10^{-12} to 10^{-8}, for paraphotons with masses in the \mu eV to meV range -- exceeding the current laboratory- and astrophysics-based limits by several orders of magnitude. Therefore, this experiment bears significant discovery potential for hidden sector physics.
1312.2467
Francois Richard
Fran\c{c}ois Richard
A Z-prime interpretation of Bd->K*mu+mu- data and consequences for high energy colliders
null
null
null
LAL--Orsay 13-397
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this note, I examine the possible consequences for high energy colliders of a Z-prime interpretation of the LHCb anomaly observed in the K*mu+mu- final state. Two examples are elaborated in the framework of the so-called 331 model. In the first one it is shown that LEP2 provides the tightest lower mass limit for the Z-prime boson, above 8 TeV, while in the second one the lower mass limit is set by ATLAS/CMS to about 3 TeV. It is then shown that precision measurements at ILC 500 GeV can fully explore the underlying structure of the model by measuring the fermion final states separately: leptons, charm, beauty and top final states. Z-prime-Z mixing can also be substantial, thus leading to possible effects almost observable at LEP1 and which can be precisely measured at GigaZ. Discovery prospects for heavy bosons and heavy fermions at LHC are also discussed .
[ { "created": "Mon, 9 Dec 2013 15:30:58 GMT", "version": "v1" } ]
2013-12-10
[ [ "Richard", "François", "" ] ]
In this note, I examine the possible consequences for high energy colliders of a Z-prime interpretation of the LHCb anomaly observed in the K*mu+mu- final state. Two examples are elaborated in the framework of the so-called 331 model. In the first one it is shown that LEP2 provides the tightest lower mass limit for the Z-prime boson, above 8 TeV, while in the second one the lower mass limit is set by ATLAS/CMS to about 3 TeV. It is then shown that precision measurements at ILC 500 GeV can fully explore the underlying structure of the model by measuring the fermion final states separately: leptons, charm, beauty and top final states. Z-prime-Z mixing can also be substantial, thus leading to possible effects almost observable at LEP1 and which can be precisely measured at GigaZ. Discovery prospects for heavy bosons and heavy fermions at LHC are also discussed .
hep-ph/0406096
Sergio Palomares-Ruiz
Sergio Palomares-Ruiz (UCLA/Vanderbilt U.) and S.T. Petcov (SISSA)
Three-Neutrino Oscillations of Atmospheric Neutrinos, theta13, Neutrino Mass Hierarchy and Iron Magnetized Detectors
27 pages, 9 figures
Nucl.Phys. B712 (2005) 392-410
10.1016/j.nuclphysb.2005.01.045
SISSA 35/04/EP, UCLA/04/TEP/24
hep-ph
null
We derive predictions for the Nadir angle (theta_n) dependence of the ratio Nmu-/Nmu+ of the rates of the mu- and mu+ multi-GeV events, and for the mu- - mu+ event rate asymmetry, A_{mu-mu+}=[Nmu- - Nmu+]/[Nmu- + Nmu+], in iron-magnetized calorimeter detectors (MINOS, INO) in the case of 3-neutrino oscillations of the atmospheric nu_mu and antinu_mu, driven by one neutrino mass squared difference, |Delta m^2_{31}| >> Delta m^2_{21}. The asymmetry A_{mu- mu+} (the ratio Nmu-/Nmu+) is shown to be particularly sensitive to the Earth matter effects in the atmospheric neutrino oscillations, and thus to the values of sin^2(theta13) and sin^2(theta23), theta13 and theta23 being the neutrino mixing angles limited by the CHOOZ and Palo Verde experiments and that responsible for the dominant atmospheric nu_mu -> nu_tau (antinu_mu -> antinu_tau) oscillations. It is also very sensitive to the type of neutrino mass spectrum which can be with normal (Delta m^2_{31}>0) or with inverted (Delta m^2_{31} < 0) hierarchy. We find that for sin^2(theta23)>0.50, sin^2(2 theta13)>0.06 and Delta m^2_{31}=(2-3) 10^{-3} eV^2, the Earth matter effects produce a relative difference between the integrated asymmetries barA_{mu- mu+} and barA^{2nu}_{mu- mu+}$ in the mantle (cos(theta_n)=0.30-0.84) and core (cos(theta_n)=0.84-1.0) bins, which is bigger in absolute value than ~15%, can reach the values of (30-35)%, and thus can be sufficiently large to be observable. The sign of the indicated asymmetry difference is anticorrelated with the sign of Delta m^2_{31}. An observation of the Earth matter effects in the Nadir angle distribution of the asymmetry A_{mu- mu+} (ratio Nmu-/Nmu+) would clearly indicate that sin^2(2 theta13)>0.06 and sin^2(theta23)>0.50, and would lead to the determination of the sign of Delta m^2_{31}.
[ { "created": "Tue, 8 Jun 2004 14:40:39 GMT", "version": "v1" } ]
2010-04-05
[ [ "Palomares-Ruiz", "Sergio", "", "UCLA/Vanderbilt U." ], [ "Petcov", "S. T.", "", "SISSA" ] ]
We derive predictions for the Nadir angle (theta_n) dependence of the ratio Nmu-/Nmu+ of the rates of the mu- and mu+ multi-GeV events, and for the mu- - mu+ event rate asymmetry, A_{mu-mu+}=[Nmu- - Nmu+]/[Nmu- + Nmu+], in iron-magnetized calorimeter detectors (MINOS, INO) in the case of 3-neutrino oscillations of the atmospheric nu_mu and antinu_mu, driven by one neutrino mass squared difference, |Delta m^2_{31}| >> Delta m^2_{21}. The asymmetry A_{mu- mu+} (the ratio Nmu-/Nmu+) is shown to be particularly sensitive to the Earth matter effects in the atmospheric neutrino oscillations, and thus to the values of sin^2(theta13) and sin^2(theta23), theta13 and theta23 being the neutrino mixing angles limited by the CHOOZ and Palo Verde experiments and that responsible for the dominant atmospheric nu_mu -> nu_tau (antinu_mu -> antinu_tau) oscillations. It is also very sensitive to the type of neutrino mass spectrum which can be with normal (Delta m^2_{31}>0) or with inverted (Delta m^2_{31} < 0) hierarchy. We find that for sin^2(theta23)>0.50, sin^2(2 theta13)>0.06 and Delta m^2_{31}=(2-3) 10^{-3} eV^2, the Earth matter effects produce a relative difference between the integrated asymmetries barA_{mu- mu+} and barA^{2nu}_{mu- mu+}$ in the mantle (cos(theta_n)=0.30-0.84) and core (cos(theta_n)=0.84-1.0) bins, which is bigger in absolute value than ~15%, can reach the values of (30-35)%, and thus can be sufficiently large to be observable. The sign of the indicated asymmetry difference is anticorrelated with the sign of Delta m^2_{31}. An observation of the Earth matter effects in the Nadir angle distribution of the asymmetry A_{mu- mu+} (ratio Nmu-/Nmu+) would clearly indicate that sin^2(2 theta13)>0.06 and sin^2(theta23)>0.50, and would lead to the determination of the sign of Delta m^2_{31}.
hep-ph/9810255
Shi-Lin Zhu
Shi-Lin Zhu (Institute of Theoretical Physics, Academia Sinica)
The suppression of $\pi N N(1535)$ coupling in QCD
8 pages, 1 figure, submitted to Mod. Phys. Lett. A
Mod.Phys.Lett.A13:2763-2770,1998
10.1142/S021773239800293X
null
hep-ph
null
The light cone QCD sum rules are employed to calculate the $\pi N N(1535)$ coupling $g_{\pi N N^\ast}$. We study the two point correlation function of two nucleon currents sandwiched between the vacuum and the pion state. The contribution from the excited states and the continuum is subtracted cleanly through double Borel transformation with respect to the nucleon and N(1535) momenta, $p_1^2$, $p_2^2=(p-q)^2$. Our calculation shows that the $\pi N N(1535)$ coupling is strongly suppressed.
[ { "created": "Tue, 6 Oct 1998 00:43:59 GMT", "version": "v1" } ]
2014-11-17
[ [ "Zhu", "Shi-Lin", "", "Institute of Theoretical Physics, Academia Sinica" ] ]
The light cone QCD sum rules are employed to calculate the $\pi N N(1535)$ coupling $g_{\pi N N^\ast}$. We study the two point correlation function of two nucleon currents sandwiched between the vacuum and the pion state. The contribution from the excited states and the continuum is subtracted cleanly through double Borel transformation with respect to the nucleon and N(1535) momenta, $p_1^2$, $p_2^2=(p-q)^2$. Our calculation shows that the $\pi N N(1535)$ coupling is strongly suppressed.
hep-ph/0002169
Pawel Jankowski
P. Jankowski, M. Krawczyk (Warsaw University), A. De Roeck (CERN)
Heavy Quark Production at a Linear e^+e^- and Photon Collider and its Sensitivity to the Gluon Content of the Photon
8 pages, Latex using epsfig.sty, including 6 postscript figures. Contribution to Proceedings of the Workshop "Physics Studies for a Future Linear Collider", Rolf Heuer, Francois Richard and Peter Zerwas Eds., 2000, DESY 123F
null
10.1016/S0168-9002(01)01185-8
IFT 2000/2
hep-ph
null
A high energy linear e^+e^- collider (LC) can also be used as a Photon Collider (PC), using Compton scattering of laser photons on the e^+/e^- beams. The leading order cross-section for the production of heavy quarks, e^+e^- -> e^+e^- Q(\bar{Q}) X, at high transverse momenta is calculated for both LC and PC modes. The sensitivity of this process to the parton distribution parametrizations of real photons, especially the gluon content, is tested for both modes.
[ { "created": "Tue, 15 Feb 2000 20:17:35 GMT", "version": "v1" }, { "created": "Wed, 16 Feb 2000 18:07:32 GMT", "version": "v2" } ]
2009-10-31
[ [ "Jankowski", "P.", "", "Warsaw University" ], [ "Krawczyk", "M.", "", "Warsaw University" ], [ "De Roeck", "A.", "", "CERN" ] ]
A high energy linear e^+e^- collider (LC) can also be used as a Photon Collider (PC), using Compton scattering of laser photons on the e^+/e^- beams. The leading order cross-section for the production of heavy quarks, e^+e^- -> e^+e^- Q(\bar{Q}) X, at high transverse momenta is calculated for both LC and PC modes. The sensitivity of this process to the parton distribution parametrizations of real photons, especially the gluon content, is tested for both modes.
hep-ph/9310352
Carlo Giunti
S.M. Bilenky and C. Giunti
Neutrino Mixing and Future Solar Neutrino Experiments
3 pages. Compressed postscript file. If you prefer the uncompressed postscript file or a hardcopy of the paper, please write to GIUNTI@TO.INFN.IT. Talk presented by S.M. Bilenky at TAUP93. DFTT 66/93
Nucl.Phys.Proc.Suppl. 35 (1994) 430-432
10.1016/0920-5632(94)90297-6
null
hep-ph
null
Possibilities of a model independent treatment of the data from future real-time solar neutrino experiments (SNO, Super-Kamiokande and others) are discussed. It is shown that in the general case of transitions of the initial solar $\nu_e$'s into $\nu_\mu$ and/or $\nu_\tau$ the total flux of initial 8B neutrinos and the $\nu_e$ survival probability can be determined directly from the experimental data. Lower bounds for the probability of transition of solar $\nu_e$'s into all possible sterile states are derived and expressed through measurable quantities.
[ { "created": "Tue, 26 Oct 1993 18:21:09 GMT", "version": "v1" } ]
2009-10-22
[ [ "Bilenky", "S. M.", "" ], [ "Giunti", "C.", "" ] ]
Possibilities of a model independent treatment of the data from future real-time solar neutrino experiments (SNO, Super-Kamiokande and others) are discussed. It is shown that in the general case of transitions of the initial solar $\nu_e$'s into $\nu_\mu$ and/or $\nu_\tau$ the total flux of initial 8B neutrinos and the $\nu_e$ survival probability can be determined directly from the experimental data. Lower bounds for the probability of transition of solar $\nu_e$'s into all possible sterile states are derived and expressed through measurable quantities.
hep-ph/0510203
Michael Trott
Michael Trott and Alexander R. Williamson
Towards the Anomalous Dimension to Order Lambda_QCD/m_b for Phase Space Restricted B --> X(u) ell anti-nu and B --> X(s) gamma
23 pages, 3 figures V2- Minor Typos Fixed
Phys.Rev.D74:034011,2006
10.1103/PhysRevD.74.034011
null
hep-ph
null
We examine the anomalous dimension matrix appropriate for the phase space restricted B --> X(u) ell anti-nu and B --> X(s) gamma decay spectra to subleading nonperturbative order. The effects of the time ordered products of the HQET Lagrangian with the leading order shape function operator are calculated, as are the anomalous dimensions of subleading operators. We establish the renormalizability and closure of a subset of the non-local operator basis, a requirement for the establishment of factorization theorems at this order. Operator mixing is found between the operators which occur to subleading order, requiring the subleading operator basis be extended. We comment on the requirement for new shape functions to be introduced to characterize the matrix elements of these new operators, and the phenomenological consequences for extractions of $|V_{ub}|$.
[ { "created": "Mon, 17 Oct 2005 18:56:47 GMT", "version": "v1" }, { "created": "Thu, 22 Dec 2005 21:50:52 GMT", "version": "v2" } ]
2008-11-26
[ [ "Trott", "Michael", "" ], [ "Williamson", "Alexander R.", "" ] ]
We examine the anomalous dimension matrix appropriate for the phase space restricted B --> X(u) ell anti-nu and B --> X(s) gamma decay spectra to subleading nonperturbative order. The effects of the time ordered products of the HQET Lagrangian with the leading order shape function operator are calculated, as are the anomalous dimensions of subleading operators. We establish the renormalizability and closure of a subset of the non-local operator basis, a requirement for the establishment of factorization theorems at this order. Operator mixing is found between the operators which occur to subleading order, requiring the subleading operator basis be extended. We comment on the requirement for new shape functions to be introduced to characterize the matrix elements of these new operators, and the phenomenological consequences for extractions of $|V_{ub}|$.
2311.06052
Aleksandra Marova
O. Shaposhnikova, A. Marova, G. Feofilov
Open and hidden strangeness with kaons and $\varphi$-mesons in Bjorken energy density approach for central A+A collisions from SPS to LHC
9 pages, 2 figures, XXV Baldin ISHEPP
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We use the available data on $<dN/dy>$ and $<\it{p}_T>$ for the identified hadrons including $\pi^{+}+\pi^{-}$, $K^{+}+K^{-}$, $p+\overline{p}$, $K^*(892)^0$ and $\varphi$-mesons, registered at midrapidity ($\vert y\vert < 0.5)$ in central 0-5% Au-Au, Pb-Pb and Xe+Xe collisions in a broad range of energies in order to compare the relative contributions to the Bjorken energy density. Particles, like strangeness-neutral $\varphi$-meson (a system of $s\overline{s})$ quarks) and K-meson (containing single s-quark), are of specific interest because they might have different production mechanisms and differ in sensitivity to the properties of the QGP-medium formed in relativistic heavy-ion collisions.
[ { "created": "Fri, 10 Nov 2023 13:31:21 GMT", "version": "v1" } ]
2023-11-13
[ [ "Shaposhnikova", "O.", "" ], [ "Marova", "A.", "" ], [ "Feofilov", "G.", "" ] ]
We use the available data on $<dN/dy>$ and $<\it{p}_T>$ for the identified hadrons including $\pi^{+}+\pi^{-}$, $K^{+}+K^{-}$, $p+\overline{p}$, $K^*(892)^0$ and $\varphi$-mesons, registered at midrapidity ($\vert y\vert < 0.5)$ in central 0-5% Au-Au, Pb-Pb and Xe+Xe collisions in a broad range of energies in order to compare the relative contributions to the Bjorken energy density. Particles, like strangeness-neutral $\varphi$-meson (a system of $s\overline{s})$ quarks) and K-meson (containing single s-quark), are of specific interest because they might have different production mechanisms and differ in sensitivity to the properties of the QGP-medium formed in relativistic heavy-ion collisions.
2311.16048
Simone Blasi
Simone Blasi, Fabio Maltoni, Alberto Mariotti, Ken Mimasu, Davide Pagani, Simone Tentori
Top-philic ALP phenomenology at the LHC: the elusive mass-window
45 pages + appendices, 23 figures; matches published version
null
null
IRMP-CP3-23-69, DESY-23-198, KCL-PH-TH/2023-68
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the LHC phenomenology of an Axion Like Particle (ALP) that couples only derivatively with the top quark at tree level. We inspect the radiatively induced couplings with the SM fermions and (gauge) bosons and the associated production and decay mechanisms of the ALP. We focus on the most challenging mass window that remains open for a top-philic ALP, i.e., the range between tens and hundreds of GeV. Not only ALP production processes but also virtual ALP contributions to final states with top quarks are considered in detail. We show how searches through resonant production, such as ALP production in association with a $t\bar t$ pair, are complementary to precision measurements of $t \bar t$ and $t\bar t t \bar t$ final states, the latter being competitive or even more powerful for a top-philic ALP in this mass window. Finally, we explore the scenario where the top-philic ALP acts as a mediator to a dark-matter sector, resulting in missing energy signatures at the LHC. We find that the LHC constraints from $t \bar t$, $t\bar t t \bar t$ and ALP + jet production, together with those from $t \bar t$ + ALP production, can already exclude a large fraction of the parameter space leading to the correct relic abundance.
[ { "created": "Mon, 27 Nov 2023 18:13:15 GMT", "version": "v1" }, { "created": "Tue, 18 Jun 2024 07:16:14 GMT", "version": "v2" } ]
2024-06-19
[ [ "Blasi", "Simone", "" ], [ "Maltoni", "Fabio", "" ], [ "Mariotti", "Alberto", "" ], [ "Mimasu", "Ken", "" ], [ "Pagani", "Davide", "" ], [ "Tentori", "Simone", "" ] ]
We study the LHC phenomenology of an Axion Like Particle (ALP) that couples only derivatively with the top quark at tree level. We inspect the radiatively induced couplings with the SM fermions and (gauge) bosons and the associated production and decay mechanisms of the ALP. We focus on the most challenging mass window that remains open for a top-philic ALP, i.e., the range between tens and hundreds of GeV. Not only ALP production processes but also virtual ALP contributions to final states with top quarks are considered in detail. We show how searches through resonant production, such as ALP production in association with a $t\bar t$ pair, are complementary to precision measurements of $t \bar t$ and $t\bar t t \bar t$ final states, the latter being competitive or even more powerful for a top-philic ALP in this mass window. Finally, we explore the scenario where the top-philic ALP acts as a mediator to a dark-matter sector, resulting in missing energy signatures at the LHC. We find that the LHC constraints from $t \bar t$, $t\bar t t \bar t$ and ALP + jet production, together with those from $t \bar t$ + ALP production, can already exclude a large fraction of the parameter space leading to the correct relic abundance.
2312.12330
Vishal Ngairangbam
Vishal S. Ngairangbam, and Michael Spannowsky
Interpretable deep learning models for the inference and classification of LHC data
Extended discussion in section 2.1. Results unchanged. Matches journal version
JHEP 05 (2024) 004
10.1007/JHEP05(2024)004
IPPP/23/81
hep-ph
http://creativecommons.org/licenses/by/4.0/
The Shower Deconstruction methodology is pivotal in distinguishing signal and background jets, leveraging the detailed information from perturbative parton showers. Rooted in the Neyman-Pearson lemma, this method is theoretically designed to differentiate between signal and background processes optimally in high-energy physics experiments. A key challenge, however, arises from the combinatorial growth associated with increasing jet constituents, which hampers its computational feasibility. We address this by demonstrating that the likelihood derived from comparing the most probable signal and background shower histories is equally effective for discrimination as the conventional approach of summing over all potential histories in top quark versus Quantum Chromodynamics (QCD) scenarios. We propose a novel approach by conceptualising the identification of the most probable shower history as a Markov Decision Process (MDP). Utilising a sophisticated modular point-transformer architecture, our method efficiently learns the optimal policy for this task. The developed neural agent excels in constructing the most likely shower history and demonstrates robust generalisation capabilities on unencountered test data. Remarkably, our approach mitigates the complexity inherent in the inference process, achieving a linear scaling relationship with the number of jet constituents. This offers a computationally viable and theoretically sound method for signal-background differentiation, paving the way for more effective data analysis in particle physics.
[ { "created": "Thu, 14 Dec 2023 20:45:12 GMT", "version": "v1" }, { "created": "Wed, 5 Jun 2024 12:27:16 GMT", "version": "v2" } ]
2024-06-06
[ [ "Ngairangbam", "Vishal S.", "" ], [ "Spannowsky", "Michael", "" ] ]
The Shower Deconstruction methodology is pivotal in distinguishing signal and background jets, leveraging the detailed information from perturbative parton showers. Rooted in the Neyman-Pearson lemma, this method is theoretically designed to differentiate between signal and background processes optimally in high-energy physics experiments. A key challenge, however, arises from the combinatorial growth associated with increasing jet constituents, which hampers its computational feasibility. We address this by demonstrating that the likelihood derived from comparing the most probable signal and background shower histories is equally effective for discrimination as the conventional approach of summing over all potential histories in top quark versus Quantum Chromodynamics (QCD) scenarios. We propose a novel approach by conceptualising the identification of the most probable shower history as a Markov Decision Process (MDP). Utilising a sophisticated modular point-transformer architecture, our method efficiently learns the optimal policy for this task. The developed neural agent excels in constructing the most likely shower history and demonstrates robust generalisation capabilities on unencountered test data. Remarkably, our approach mitigates the complexity inherent in the inference process, achieving a linear scaling relationship with the number of jet constituents. This offers a computationally viable and theoretically sound method for signal-background differentiation, paving the way for more effective data analysis in particle physics.
1805.04830
Wei Chao
Wei Chao
Hybrid Dark Matter
10 pages, 2 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Dark matter can be produced in the early universe via the freeze-in or freeze-out mechanisms. Both scenarios were investigated in references, but the production of dark matters via the combination of these two mechanisms are not addressed. In this paper we propose a hybrid dark matter model where dark matters have two components with one component produced thermally and the other one produced non-thermally. We present for the first time the analytical calculation for the relic abundance of the Higgs portal hybrid dark matter, then we investigate constraints on the parameter space of the model from dark matter direct and indirect detection experiments.
[ { "created": "Sun, 13 May 2018 06:39:56 GMT", "version": "v1" } ]
2018-05-15
[ [ "Chao", "Wei", "" ] ]
Dark matter can be produced in the early universe via the freeze-in or freeze-out mechanisms. Both scenarios were investigated in references, but the production of dark matters via the combination of these two mechanisms are not addressed. In this paper we propose a hybrid dark matter model where dark matters have two components with one component produced thermally and the other one produced non-thermally. We present for the first time the analytical calculation for the relic abundance of the Higgs portal hybrid dark matter, then we investigate constraints on the parameter space of the model from dark matter direct and indirect detection experiments.
hep-ph/9607302
Colin Froggatt
C. D. Froggatt and H. B. Nielsen
Dynamical determination of the top quark and Higgs masses in the Standard Model
uuencoded 13 page LaTeX2e file plus 5 postscript figures, uses epsf.sty and psfig.sty; paper contributed to ICHEP96, Warsaw, 25-31 July 1996
null
null
GUTPA-96-7-2, ICHEP96 Pa 08-012
hep-ph
null
We consider the application of the multiple point criticality principle to the pure Standard Model, with a desert up to the Planck scale. According to this principle, Nature should choose coupling constant values such that the vacuum can exist in degenerate phases. Furthermore we require a strongly first order phase transition between the two vacua, in order that the dynamical mechanism be relevant. Thus we impose the constraint that the effective Higgs potential should have two degenerate minima, one of which should have a vacuum expectation value of order unity in Planck units. In this way we predict a top quark mass of 173 +/- 4 GeV and a Higgs particle mass of 135 +/- 9 GeV. A possible model to explain the multiple point criticality principle is the lack of locality in quantum gravity and the effects of baby universes which, on general grounds, are expected to make coupling constants dynamical.
[ { "created": "Fri, 12 Jul 1996 16:14:21 GMT", "version": "v1" } ]
2007-05-23
[ [ "Froggatt", "C. D.", "" ], [ "Nielsen", "H. B.", "" ] ]
We consider the application of the multiple point criticality principle to the pure Standard Model, with a desert up to the Planck scale. According to this principle, Nature should choose coupling constant values such that the vacuum can exist in degenerate phases. Furthermore we require a strongly first order phase transition between the two vacua, in order that the dynamical mechanism be relevant. Thus we impose the constraint that the effective Higgs potential should have two degenerate minima, one of which should have a vacuum expectation value of order unity in Planck units. In this way we predict a top quark mass of 173 +/- 4 GeV and a Higgs particle mass of 135 +/- 9 GeV. A possible model to explain the multiple point criticality principle is the lack of locality in quantum gravity and the effects of baby universes which, on general grounds, are expected to make coupling constants dynamical.
2107.06203
Martin Hentschinski
Martin Hentschinski
Transverse Momentum Dependent Gluon Distribution within High Energy Factorization at Next-to-Leading Order
36 pages, 28 figures, updated references and comment added. Version accepted for publication in Physical Review D
Phys. Rev. D 104, 054014 (2021)
10.1103/PhysRevD.104.054014
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss Transverse Momentum Dependent (TMD) gluon distributions within high energy factorization at next-to-leading order in the strong coupling within the framework of Lipatov's high energy effective action. We provide a detailed discussion of both rapidity divergences related to the TMD definition and its soft factor on the one hand, and rapidity divergences due to high energy factorization on the other hand, and discuss common features and differences between Collins-Soper (CS) and Balitsky-Fadin-Kuarev-Lipatov (BFKL) evolution. While we confirm earlier results which state that the unpolarized and linearly polarized gluon TMD agree in the BFKL limit at leading order, we find that both distributions differ, once next-to-leading order corrections are being included. Unlike previous results, our framework allows to recover the complete anomalous dimension associated with Collins-Soper-Sterman (CSS) evolution of the TMD distribution, including also single-logarithmic terms in the CSS evolution. As an additional result we provide a definition of $k_T$-factorization, i.e. matching of off-shell coefficients to collinear factorization at next-to-leading order within high energy factorization and the effective action framework. We furthermore establish a link between the QCD operator definition of the TMD gluon distribution and a previously derived off-shell TMD gluon-to-gluon splitting function, which is within the present framework obtained as the real 1-loop correction.
[ { "created": "Tue, 13 Jul 2021 16:02:51 GMT", "version": "v1" }, { "created": "Tue, 17 Aug 2021 00:04:38 GMT", "version": "v2" } ]
2021-09-22
[ [ "Hentschinski", "Martin", "" ] ]
We discuss Transverse Momentum Dependent (TMD) gluon distributions within high energy factorization at next-to-leading order in the strong coupling within the framework of Lipatov's high energy effective action. We provide a detailed discussion of both rapidity divergences related to the TMD definition and its soft factor on the one hand, and rapidity divergences due to high energy factorization on the other hand, and discuss common features and differences between Collins-Soper (CS) and Balitsky-Fadin-Kuarev-Lipatov (BFKL) evolution. While we confirm earlier results which state that the unpolarized and linearly polarized gluon TMD agree in the BFKL limit at leading order, we find that both distributions differ, once next-to-leading order corrections are being included. Unlike previous results, our framework allows to recover the complete anomalous dimension associated with Collins-Soper-Sterman (CSS) evolution of the TMD distribution, including also single-logarithmic terms in the CSS evolution. As an additional result we provide a definition of $k_T$-factorization, i.e. matching of off-shell coefficients to collinear factorization at next-to-leading order within high energy factorization and the effective action framework. We furthermore establish a link between the QCD operator definition of the TMD gluon distribution and a previously derived off-shell TMD gluon-to-gluon splitting function, which is within the present framework obtained as the real 1-loop correction.
0804.3296
Koichi Hamaguchi
Koichi Hamaguchi, Eita Nakamura, Satoshi Shirai and T. T. Yanagida
Strongly Interacting Gauge Mediation at the LHC
14 pages, 7 figures
JHEP 0807:107,2008
10.1088/1126-6708/2008/07/107
UT-08-09, IPMU-08-0023
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Strongly interacting gauge mediation (SIGM) of supersymmetry breaking is very attractive, since it naturally predicts a light gravitino of mass $\lsim{\cal O}(10)$ eV, which causes no cosmological problem. We discuss various signatures of the SIGM in the early stage (a low integrated luminosity period) of the LHC experiments. We show, in particular, a possible way to discriminate it from the conventional gauge mediation by counting the number of high $P_{\rm T}$ leptons.
[ { "created": "Mon, 21 Apr 2008 12:44:54 GMT", "version": "v1" }, { "created": "Mon, 14 Jul 2008 03:46:36 GMT", "version": "v2" } ]
2009-02-09
[ [ "Hamaguchi", "Koichi", "" ], [ "Nakamura", "Eita", "" ], [ "Shirai", "Satoshi", "" ], [ "Yanagida", "T. T.", "" ] ]
Strongly interacting gauge mediation (SIGM) of supersymmetry breaking is very attractive, since it naturally predicts a light gravitino of mass $\lsim{\cal O}(10)$ eV, which causes no cosmological problem. We discuss various signatures of the SIGM in the early stage (a low integrated luminosity period) of the LHC experiments. We show, in particular, a possible way to discriminate it from the conventional gauge mediation by counting the number of high $P_{\rm T}$ leptons.
hep-ph/0505138
Yong Zhou
Yong Zhou
Boson's field renormalization prescription
8 pages, 4 figures
null
null
null
hep-ph
null
We discuss the problem of the present boson's field renormalization prescription induced by the imaginary parts of the unstable boson's propagation amplitudes and how to resolve it.
[ { "created": "Mon, 16 May 2005 09:52:16 GMT", "version": "v1" } ]
2007-05-23
[ [ "Zhou", "Yong", "" ] ]
We discuss the problem of the present boson's field renormalization prescription induced by the imaginary parts of the unstable boson's propagation amplitudes and how to resolve it.
hep-ph/9406298
Patrick Kelly
P.F. Kelly, R. Kobes, and G. Kunstatter
Parameterization Invariance and the Resolution of the Unitary Gauge Puzzle
MIT--CTP--2299, WIN--93--09, ENSLAPP--A--470/94, NSF--ITP--94--62, In plain TeX
Phys.Rev. D50 (1994) 7592-7602
10.1103/PhysRevD.50.7592
null
hep-ph hep-th
null
We examine the calculation of the critical temperature $T_c$ for the restoration of a spontaneously broken symmetry. Motivated by a set of recently developed gauge dependence identities, we give a gauge and parameterization independent definition of this temperature in terms of the physical mass of the scalar particle as determined by the propagator pole. As an explicit illustration, we consider the Abelian Higgs model in the unitary gauge, where the usual definition of the critical temperature based upon the effective potential leads to an erroneous result. We show how the gauge invariant definition reproduces the correct result as found in the ``renormalizable'' parameterizations.
[ { "created": "Mon, 13 Jun 1994 16:32:16 GMT", "version": "v1" } ]
2009-10-28
[ [ "Kelly", "P. F.", "" ], [ "Kobes", "R.", "" ], [ "Kunstatter", "G.", "" ] ]
We examine the calculation of the critical temperature $T_c$ for the restoration of a spontaneously broken symmetry. Motivated by a set of recently developed gauge dependence identities, we give a gauge and parameterization independent definition of this temperature in terms of the physical mass of the scalar particle as determined by the propagator pole. As an explicit illustration, we consider the Abelian Higgs model in the unitary gauge, where the usual definition of the critical temperature based upon the effective potential leads to an erroneous result. We show how the gauge invariant definition reproduces the correct result as found in the ``renormalizable'' parameterizations.
1007.2378
Emiliano Molinaro
A. Ibarra, E. Molinaro, S. T. Petcov
TeV Scale See-Saw Mechanisms of Neutrino Mass Generation, the Majorana Nature of the Heavy Singlet Neutrinos and $\betabeta$-Decay
22 pages
JHEP 1009:108,2010
10.1007/JHEP09(2010)108
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is shown that the Majorana nature of the heavy neutrinos $N_j$ having masses in the range of $M_j \sim (100 - 1000)$ GeV and present in the TeV scale type I and inverse see-saw scenarios of neutrino mass generation, is unlikely to be observable in the currently operating and future planned accelerator experiments (including LHC) due to the existence of very strong constraints on the parameters and couplings responsible for the corresponding $|\Delta L| = 2$ processes, $L$ being the total lepton charge. If the heavy Majorana neutrinos $N_j$ are observed and they are associated only with the type I or inverse see-saw mechanisms and no additional TeV scale "new physics", they will behave like Dirac fermions to a relatively high level of precision, being actually pseudo-Dirac particles. The observation of effects proving the Majorana nature of $N_j$ would imply that these heavy neutrinos have additional relatively strong couplings to the Standard Model particles (as, e.g. in the type III see-saw scenario), or that light neutrino masses compatible with the observations are generated by a mechanism other than see-saw (e.g., radiatively at one or two loop level) in which the heavy Majorana neutrinos $N_j$ are nevertheless involved.
[ { "created": "Wed, 14 Jul 2010 17:00:02 GMT", "version": "v1" } ]
2014-11-21
[ [ "Ibarra", "A.", "" ], [ "Molinaro", "E.", "" ], [ "Petcov", "S. T.", "" ] ]
It is shown that the Majorana nature of the heavy neutrinos $N_j$ having masses in the range of $M_j \sim (100 - 1000)$ GeV and present in the TeV scale type I and inverse see-saw scenarios of neutrino mass generation, is unlikely to be observable in the currently operating and future planned accelerator experiments (including LHC) due to the existence of very strong constraints on the parameters and couplings responsible for the corresponding $|\Delta L| = 2$ processes, $L$ being the total lepton charge. If the heavy Majorana neutrinos $N_j$ are observed and they are associated only with the type I or inverse see-saw mechanisms and no additional TeV scale "new physics", they will behave like Dirac fermions to a relatively high level of precision, being actually pseudo-Dirac particles. The observation of effects proving the Majorana nature of $N_j$ would imply that these heavy neutrinos have additional relatively strong couplings to the Standard Model particles (as, e.g. in the type III see-saw scenario), or that light neutrino masses compatible with the observations are generated by a mechanism other than see-saw (e.g., radiatively at one or two loop level) in which the heavy Majorana neutrinos $N_j$ are nevertheless involved.
2206.07053
Prateek Agrawal
Prateek Agrawal, Michael Nee, and Mario Reig
Axion Couplings in Grand Unified Theories
23 pages, 4 figures; References added
null
10.1007/JHEP10(2022)141
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We show that the couplings of axions to gauge bosons are highly restricted in Grand Unified Theories where the standard model is embedded in a simple 4D gauge group. The topological nature of these couplings allows them to be matched from the UV to the IR, and the ratio of the anomaly with photons and gluons for any axion is fixed by unification. This implies that there is a single axion, the QCD axion, with an anomalous coupling to photons. Other light axion-like particles can couple to photons by mixing through the QCD axion portal and lie to the right of the QCD line in the mass-coupling plane. Axions which break the unification relation between gluon and photon couplings are necessarily charged under the GUT gauge group and become heavy from perturbative mass contributions. A discovery of an axion to the left of the QCD line can rule out simple Grand Unified models. Axion searches are therefore tabletop and astrophysical probes of Grand Unification.
[ { "created": "Tue, 14 Jun 2022 18:00:00 GMT", "version": "v1" }, { "created": "Wed, 22 Jun 2022 13:09:48 GMT", "version": "v2" } ]
2022-11-09
[ [ "Agrawal", "Prateek", "" ], [ "Nee", "Michael", "" ], [ "Reig", "Mario", "" ] ]
We show that the couplings of axions to gauge bosons are highly restricted in Grand Unified Theories where the standard model is embedded in a simple 4D gauge group. The topological nature of these couplings allows them to be matched from the UV to the IR, and the ratio of the anomaly with photons and gluons for any axion is fixed by unification. This implies that there is a single axion, the QCD axion, with an anomalous coupling to photons. Other light axion-like particles can couple to photons by mixing through the QCD axion portal and lie to the right of the QCD line in the mass-coupling plane. Axions which break the unification relation between gluon and photon couplings are necessarily charged under the GUT gauge group and become heavy from perturbative mass contributions. A discovery of an axion to the left of the QCD line can rule out simple Grand Unified models. Axion searches are therefore tabletop and astrophysical probes of Grand Unification.
1006.5324
Volkan Ari
V. Ari, O. Cakir, I. T. Cakir and S. Sultansoy
Pair Production of Fourth Family Charged Sleptons at $e^{+}e^{-}$ Colliders
6 pages, 2 figures
Europhys.Lett.94:21001,2011
10.1209/0295-5075/94/21001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the pair production of $\tilde{l}_{4}$, which is the supersymmetric partner of the fourth family charged lepton, at the $e^{+}e^{-}$ colliders. It is shown that the investigation of this process at ILC/CLIC will give opportunity to differentiate the MSSM with three and four families.
[ { "created": "Mon, 28 Jun 2010 11:34:29 GMT", "version": "v1" }, { "created": "Mon, 16 Aug 2010 11:09:01 GMT", "version": "v2" }, { "created": "Mon, 23 Aug 2010 10:48:47 GMT", "version": "v3" } ]
2011-04-22
[ [ "Ari", "V.", "" ], [ "Cakir", "O.", "" ], [ "Cakir", "I. T.", "" ], [ "Sultansoy", "S.", "" ] ]
We study the pair production of $\tilde{l}_{4}$, which is the supersymmetric partner of the fourth family charged lepton, at the $e^{+}e^{-}$ colliders. It is shown that the investigation of this process at ILC/CLIC will give opportunity to differentiate the MSSM with three and four families.
hep-ph/9503332
Heath O'Connell
H.B. O'Connell, B.C. Pearce, A.W. Thomas, A.G. Williams
Rho-omega Mixing and the Pion Electromagnetic Form-Factor
11 pages with epsfig.sty. Publication details added to title page
Phys.Lett.B354:14-19,1995
10.1016/0370-2693(95)00642-X
ADP-95-15/T176
hep-ph nucl-th
null
The suggestion of momentum dependence in the amplitude for rho-omega mixing has generated concern over related implications for vector meson dominance and the photon-rho coupling. We discuss two established representations of vector meson dominance and show that one of these is completely consistent with such a coupling. We then apply it to a calculation of the pion electromagnetic form-factor. Our analysis leads to a new value for the on-shell rho-omega mixing amplitude of (-3800 +/- 370) MeV^2.
[ { "created": "Wed, 15 Mar 1995 04:05:35 GMT", "version": "v1" }, { "created": "Sun, 31 May 1998 17:32:41 GMT", "version": "v2" } ]
2008-11-26
[ [ "O'Connell", "H. B.", "" ], [ "Pearce", "B. C.", "" ], [ "Thomas", "A. W.", "" ], [ "Williams", "A. G.", "" ] ]
The suggestion of momentum dependence in the amplitude for rho-omega mixing has generated concern over related implications for vector meson dominance and the photon-rho coupling. We discuss two established representations of vector meson dominance and show that one of these is completely consistent with such a coupling. We then apply it to a calculation of the pion electromagnetic form-factor. Our analysis leads to a new value for the on-shell rho-omega mixing amplitude of (-3800 +/- 370) MeV^2.
1203.0237
Alessandro Strumia
Joan Elias-Mir\'o, Jos\'e R. Espinosa, Gian F. Giudice, Hyun Min Lee, Alessandro Strumia
Stabilization of the Electroweak Vacuum by a Scalar Threshold Effect
18 pages, 5 figures
null
10.1007/JHEP06(2012)031
CERN-TH/2012-059
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show how a heavy scalar singlet with a large vacuum expectation value can evade the potential instability of the Standard Model electroweak vacuum. The quartic interaction between the heavy scalar singlet and the Higgs doublet leads to a positive tree-level threshold correction for the Higgs quartic coupling, which is very effective in stabilizing the potential. We provide examples, such as the see-saw, invisible axion and unitarized Higgs inflation, where the proposed mechanism is automatically implemented in well-defined ranges of Higgs masses.
[ { "created": "Thu, 1 Mar 2012 16:31:32 GMT", "version": "v1" } ]
2015-06-04
[ [ "Elias-Miró", "Joan", "" ], [ "Espinosa", "José R.", "" ], [ "Giudice", "Gian F.", "" ], [ "Lee", "Hyun Min", "" ], [ "Strumia", "Alessandro", "" ] ]
We show how a heavy scalar singlet with a large vacuum expectation value can evade the potential instability of the Standard Model electroweak vacuum. The quartic interaction between the heavy scalar singlet and the Higgs doublet leads to a positive tree-level threshold correction for the Higgs quartic coupling, which is very effective in stabilizing the potential. We provide examples, such as the see-saw, invisible axion and unitarized Higgs inflation, where the proposed mechanism is automatically implemented in well-defined ranges of Higgs masses.
0705.2360
Zhifeng Xie
Yue-Liang Wu, Zhi-Feng Xie
A Three-Flavor AdS/QCD Model with a Back-Reacted Geometry
10 pages, 2 figures; references revised, minor change for caption of fig 2
JHEP 0710:009,2007
10.1088/1126-6708/2007/10/009
null
hep-ph
null
A fully back-reaction geometry model of AdS/QCD including the strange quark is described. We find that with the inclusion of the strange quark the impact on the metric is very small and the final predictions are changed only negligibly.
[ { "created": "Wed, 16 May 2007 14:14:08 GMT", "version": "v1" }, { "created": "Sat, 2 Jun 2007 08:44:30 GMT", "version": "v2" } ]
2009-04-21
[ [ "Wu", "Yue-Liang", "" ], [ "Xie", "Zhi-Feng", "" ] ]
A fully back-reaction geometry model of AdS/QCD including the strange quark is described. We find that with the inclusion of the strange quark the impact on the metric is very small and the final predictions are changed only negligibly.
1508.00314
Ji-Chong Yang Mr
Ji-Chong Yang and Mao-Zhi Yang
Effect of the Charged Higgs Bosons in the Radiative Leptonic Decays of $B^-$ and $D^-$ Mesons
17 pages, 7 figures
null
10.1142/S0217732316500127
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we study the radiative leptonic decays of $B^-$ and $D^-$ mesons in the standard model and the two-Higgs-doublet-model type II. The results are obtained using the factorization procedure, and the contribution of the order $O(\Lambda _{\rm QCD}\left/m_Q\right.)$ is included. The numerical results are calculated using the wave-function obtained in relativistic potential model. As a result, the decay mode $B\to \gamma \tau \nu_{\tau}$ is found to be sensitive to the effect of the charged Higgs boson. Using the constraint on the free parameters of the two Higgs doublet model given in previous works, we find the contribution of the charged Higgs boson in the decay mode $B\to \gamma \tau \nu_{\tau}$ can be as large as about $13\%$.
[ { "created": "Mon, 3 Aug 2015 05:02:44 GMT", "version": "v1" } ]
2016-02-17
[ [ "Yang", "Ji-Chong", "" ], [ "Yang", "Mao-Zhi", "" ] ]
In this work, we study the radiative leptonic decays of $B^-$ and $D^-$ mesons in the standard model and the two-Higgs-doublet-model type II. The results are obtained using the factorization procedure, and the contribution of the order $O(\Lambda _{\rm QCD}\left/m_Q\right.)$ is included. The numerical results are calculated using the wave-function obtained in relativistic potential model. As a result, the decay mode $B\to \gamma \tau \nu_{\tau}$ is found to be sensitive to the effect of the charged Higgs boson. Using the constraint on the free parameters of the two Higgs doublet model given in previous works, we find the contribution of the charged Higgs boson in the decay mode $B\to \gamma \tau \nu_{\tau}$ can be as large as about $13\%$.
2408.07131
Niseem Magdy
Niseem Magdy, Abhay Deshpande, Roy Lacey, Wenliang Li, Prithwish Tribedy and Zhangbu Xu
Search for baryon junctions in e+A collisions at the Electron Ion Collider
6 pages, 7 figures, submitted for publication
null
null
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Constituent quarks in a nucleon are the essential elements in the standard ``quark model" associated with the electric charge, spin, mass, and baryon number of a nucleon. Quantum Chromodynamics (QCD) describes nucleon as a composite object containing current quarks (valence quarks and sea (anti-)quarks) and gluons. These subatomic elements and their interactions are known to contribute in complex ways to the overall nucleon spin and mass. In the early development of QCD theory in the 1970s, an alternative hypothesis postulated that the baryon number might manifest itself through a non-perturbative configuration of gluon fields forming a Y-shaped topology known as the gluon junction. In this work, we propose to test such hypothesis by measuring (i) the Regge intercept of the net-baryon distributions for $e$+($p$)Au collisions, (ii) baryon and charge transport in the isobaric ratio between $e$+Ru and $e$+Zr collisions, and (iii) target flavor dependence of proton and antiproton yields at large rapidity, transported from the hydrogen and deuterium targets in $e+p$(d) collisions. Our study indicates that these measurements at the EIC can help determine what carries the baryon number.
[ { "created": "Tue, 13 Aug 2024 18:00:50 GMT", "version": "v1" } ]
2024-08-15
[ [ "Magdy", "Niseem", "" ], [ "Deshpande", "Abhay", "" ], [ "Lacey", "Roy", "" ], [ "Li", "Wenliang", "" ], [ "Tribedy", "Prithwish", "" ], [ "Xu", "Zhangbu", "" ] ]
Constituent quarks in a nucleon are the essential elements in the standard ``quark model" associated with the electric charge, spin, mass, and baryon number of a nucleon. Quantum Chromodynamics (QCD) describes nucleon as a composite object containing current quarks (valence quarks and sea (anti-)quarks) and gluons. These subatomic elements and their interactions are known to contribute in complex ways to the overall nucleon spin and mass. In the early development of QCD theory in the 1970s, an alternative hypothesis postulated that the baryon number might manifest itself through a non-perturbative configuration of gluon fields forming a Y-shaped topology known as the gluon junction. In this work, we propose to test such hypothesis by measuring (i) the Regge intercept of the net-baryon distributions for $e$+($p$)Au collisions, (ii) baryon and charge transport in the isobaric ratio between $e$+Ru and $e$+Zr collisions, and (iii) target flavor dependence of proton and antiproton yields at large rapidity, transported from the hydrogen and deuterium targets in $e+p$(d) collisions. Our study indicates that these measurements at the EIC can help determine what carries the baryon number.
2304.07964
Xiao-Yun Wang
Xiao-Yun Wang, Chen Dong, Quanjin Wang
First characterization of the scattering length distribution of vector meson interaction with deuteron
6 pages, 7 figures
null
null
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
Under the framework of the vector meson dominance model (VMD), the absolute scattering lengths of light vector mesons ($\phi$, $\omega$, and $\rho$) with the deuteron are calculated from the cross sections of vector meson photoproduction off a deuteron. Additionally, a fitting function is used to predict the scattering lengths of the heavy vector mesons $J/\psi$-$d$ and $% \Upsilon$-$d$. Based on these results, the distribution of the scattering lengths $|\alpha_{V d}|$ between vector mesons and the deuteron is presented for the first time and compared with the scattering lengths $|\alpha_{V p}|$ between vector mesons and the proton. It is found that as the mass of the vector meson increases, the scattering lengths $|\alpha_{V d}|$ become closer to $|\alpha_{V p}|$. In addition, the correlation analysis indicates a strong positive relationship between the scattering length and the vector meson radius, with a high correlation coefficient. The implications of results are essential for improving our understanding of the interaction between hadron and nucleus.
[ { "created": "Mon, 17 Apr 2023 03:14:46 GMT", "version": "v1" }, { "created": "Wed, 3 Jul 2024 04:22:48 GMT", "version": "v2" } ]
2024-07-04
[ [ "Wang", "Xiao-Yun", "" ], [ "Dong", "Chen", "" ], [ "Wang", "Quanjin", "" ] ]
Under the framework of the vector meson dominance model (VMD), the absolute scattering lengths of light vector mesons ($\phi$, $\omega$, and $\rho$) with the deuteron are calculated from the cross sections of vector meson photoproduction off a deuteron. Additionally, a fitting function is used to predict the scattering lengths of the heavy vector mesons $J/\psi$-$d$ and $% \Upsilon$-$d$. Based on these results, the distribution of the scattering lengths $|\alpha_{V d}|$ between vector mesons and the deuteron is presented for the first time and compared with the scattering lengths $|\alpha_{V p}|$ between vector mesons and the proton. It is found that as the mass of the vector meson increases, the scattering lengths $|\alpha_{V d}|$ become closer to $|\alpha_{V p}|$. In addition, the correlation analysis indicates a strong positive relationship between the scattering length and the vector meson radius, with a high correlation coefficient. The implications of results are essential for improving our understanding of the interaction between hadron and nucleus.
1807.08911
Venktesh Singh Dr
Deepika Grover, Kapil Saraswat, Prashant Shukla, Venktesh Singh
Charged current quasi elastic scattering of muon anti-neutrino off ^{12}C
07 pages, 09 Figures
Chainese Physics C (2018)
10.1088/1674-1137/42/12/123104
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we study charged current quasi elastic scattering of muon anti-neutrino off nucleon and nucleus using a formalism based on Llewellyn Smith (LS) model. Parameterizations by Galster et al. are used for electric and magnetic Sach's form factors of nucleons. We use Fermi gas model along with Pauli suppression condition to take into account the nuclear effects in anti-neutrino - nucleus QES. We calculate muon anti-neutrino-p and muon anti-neutrino-^{12}C charged current quasi elastic scattering differential and total cross sections for different values of axial mass M_{A} and compare the results with data from GGM, SKAT, BNL, NOMAD, MINERvA and MiniBooNE experiments. The present theoretical approach gives an excellent description of differential cross section data. The calculations with axial mass M_{A} = 0.979 and 1.05 GeV are compatible with data from most of the experiments.
[ { "created": "Tue, 24 Jul 2018 05:43:44 GMT", "version": "v1" } ]
2018-12-05
[ [ "Grover", "Deepika", "" ], [ "Saraswat", "Kapil", "" ], [ "Shukla", "Prashant", "" ], [ "Singh", "Venktesh", "" ] ]
In this work, we study charged current quasi elastic scattering of muon anti-neutrino off nucleon and nucleus using a formalism based on Llewellyn Smith (LS) model. Parameterizations by Galster et al. are used for electric and magnetic Sach's form factors of nucleons. We use Fermi gas model along with Pauli suppression condition to take into account the nuclear effects in anti-neutrino - nucleus QES. We calculate muon anti-neutrino-p and muon anti-neutrino-^{12}C charged current quasi elastic scattering differential and total cross sections for different values of axial mass M_{A} and compare the results with data from GGM, SKAT, BNL, NOMAD, MINERvA and MiniBooNE experiments. The present theoretical approach gives an excellent description of differential cross section data. The calculations with axial mass M_{A} = 0.979 and 1.05 GeV are compatible with data from most of the experiments.
hep-ph/0302222
John McDonald
John McDonald
Right-Handed Sneutrinos as Curvatons
23 pages LaTeX, minor alterations, version to be published
Phys.Rev. D68 (2003) 043505
10.1103/PhysRevD.68.043505
null
hep-ph astro-ph
null
We consider the possibility that a right-handed sneutrino can serve as the source of energy density perturbations leading to structure formation in cosmology. The cosmological evolution of a coherently oscillating condensate of right-handed sneutrinos is studied for the case where reheating after inflation is due to perturbative inflaton decays. For the case of Dirac neutrinos, it is shown that some suppression of Planck scale-suppressed corrections to the right-handed neutrino superpotential is necessary. cH^2 corrections to the sneutrino mass squared term must also be suppressed during inflation (|c| < 0.1), in which case, depending on the magnitude of |c| during inflation, a significantly blue (if c > 0) or red (if c < 0) perturbation spectrum is possible. R-parity must also be broken in order to ensure that the Universe is not overclosed by LSPs from the late decay (at temperatures 1-10 MeV) of the right-handed sneutrino condensate. The resulting expansion rate during inflation can be significantly smaller than in conventional supersymmetric inflation models (as low as 10^6 GeV is possible). For the case of Majorana neutrinos, a more severe suppression of Planck-suppressed superpotential corrections is required. In addition, the Majorana sneutrino condensate is likely to be thermalised before it can dominate the energy density, which would exclude the Majorana right-handed sneutrino as a curvaton.
[ { "created": "Tue, 25 Feb 2003 11:24:44 GMT", "version": "v1" }, { "created": "Tue, 11 Mar 2003 11:33:22 GMT", "version": "v2" }, { "created": "Tue, 15 Apr 2003 11:47:28 GMT", "version": "v3" }, { "created": "Tue, 29 Jul 2003 13:31:03 GMT", "version": "v4" } ]
2009-11-10
[ [ "McDonald", "John", "" ] ]
We consider the possibility that a right-handed sneutrino can serve as the source of energy density perturbations leading to structure formation in cosmology. The cosmological evolution of a coherently oscillating condensate of right-handed sneutrinos is studied for the case where reheating after inflation is due to perturbative inflaton decays. For the case of Dirac neutrinos, it is shown that some suppression of Planck scale-suppressed corrections to the right-handed neutrino superpotential is necessary. cH^2 corrections to the sneutrino mass squared term must also be suppressed during inflation (|c| < 0.1), in which case, depending on the magnitude of |c| during inflation, a significantly blue (if c > 0) or red (if c < 0) perturbation spectrum is possible. R-parity must also be broken in order to ensure that the Universe is not overclosed by LSPs from the late decay (at temperatures 1-10 MeV) of the right-handed sneutrino condensate. The resulting expansion rate during inflation can be significantly smaller than in conventional supersymmetric inflation models (as low as 10^6 GeV is possible). For the case of Majorana neutrinos, a more severe suppression of Planck-suppressed superpotential corrections is required. In addition, the Majorana sneutrino condensate is likely to be thermalised before it can dominate the energy density, which would exclude the Majorana right-handed sneutrino as a curvaton.
1505.01176
Yuri V. Kovchegov
Yuri V. Kovchegov, Matthew D. Sievert
Calculating TMDs of a Large Nucleus: Quasi-Classical Approximation and Quantum Evolution
56 pages, 14 figures; v2: typos corrected, references added; v3: more typos corrected, title slightly modified
Nuclear Physics B 903, 164-203 (2016)
10.1016/j.nuclphysb.2015.12.008
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We set up a formalism for calculating transverse-momentum-dependent parton distribution functions (TMDs) using the tools of saturation physics. By generalizing the quasi-classical Glauber-Gribov-Mueller/McLerran-Venugopalan approximation to allow for the possibility of spin-orbit coupling, we show how any TMD can be calculated in the saturation framework. This can also be applied to the TMDs of a proton by modeling it as a large "nucleus." To illustrate our technique, we calculate the quark TMDs of an unpolarized nucleus at large-x: the unpolarized quark distribution and the quark Boer-Mulders distribution. We observe that spin-orbit coupling leads to mixing between different TMDs of the nucleus and of the nucleons. We then consider the evolution of TMDs: at large-x, in the double-logarithmic approximation, we obtain the Sudakov form factor. At small-x the evolution of unpolarized-target quark TMDs is governed by BK/JIMWLK evolution, while the small-x evolution of polarized-target quark TMDs appears to be dominated by the QCD Reggeon.
[ { "created": "Tue, 5 May 2015 20:07:05 GMT", "version": "v1" }, { "created": "Mon, 22 Jun 2015 18:54:26 GMT", "version": "v2" }, { "created": "Mon, 21 Dec 2015 16:57:34 GMT", "version": "v3" } ]
2015-12-31
[ [ "Kovchegov", "Yuri V.", "" ], [ "Sievert", "Matthew D.", "" ] ]
We set up a formalism for calculating transverse-momentum-dependent parton distribution functions (TMDs) using the tools of saturation physics. By generalizing the quasi-classical Glauber-Gribov-Mueller/McLerran-Venugopalan approximation to allow for the possibility of spin-orbit coupling, we show how any TMD can be calculated in the saturation framework. This can also be applied to the TMDs of a proton by modeling it as a large "nucleus." To illustrate our technique, we calculate the quark TMDs of an unpolarized nucleus at large-x: the unpolarized quark distribution and the quark Boer-Mulders distribution. We observe that spin-orbit coupling leads to mixing between different TMDs of the nucleus and of the nucleons. We then consider the evolution of TMDs: at large-x, in the double-logarithmic approximation, we obtain the Sudakov form factor. At small-x the evolution of unpolarized-target quark TMDs is governed by BK/JIMWLK evolution, while the small-x evolution of polarized-target quark TMDs appears to be dominated by the QCD Reggeon.
1108.5965
Mikko Laine
M. Laine
News on hadrons in a hot medium
13 pages. Presentation at XIV International Conference on Hadron Spectroscopy (hadron2011), 13-17 June 2011, Munich, Germany
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Some of the modifications that a thermal medium, of the type generated in heavy ion collision experiments at the LHC, may impose on the properties of hadrons, are reviewed. The focus is on hadrons containing at least one heavy quark (charm or bottom or their antiparticles).
[ { "created": "Tue, 30 Aug 2011 14:16:09 GMT", "version": "v1" } ]
2011-08-31
[ [ "Laine", "M.", "" ] ]
Some of the modifications that a thermal medium, of the type generated in heavy ion collision experiments at the LHC, may impose on the properties of hadrons, are reviewed. The focus is on hadrons containing at least one heavy quark (charm or bottom or their antiparticles).
1505.01987
Keisuke Harigaya
Keisuke Harigaya, Tsutomu T. Yanagida and Norimi Yokozaki
Muon g-2 in Focus Point SUSY
24 pages, 5 figures
Phys. Rev. D 92, 035011 (2015)
10.1103/PhysRevD.92.035011
IPMU 15-0066
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We point out that the anomaly of the muon $g-2$ can be easily explained in a focus point supersymmetry scenario, which realizes the semi-natural supersymmetry. Among known focus point supersymmetry scenarios, we find that a model based on Higgs-gaugino mediation works with a mild fine-tuning $\Delta=40$-$80$. We propose two new focus point supersymmetry scenarios where the anomaly of the muon $g-2$ is also explained. These scenarios are variants of the widely known focus point supersymmetry based on gravity mediation with universal scalar masses.
[ { "created": "Fri, 8 May 2015 10:39:24 GMT", "version": "v1" } ]
2015-08-26
[ [ "Harigaya", "Keisuke", "" ], [ "Yanagida", "Tsutomu T.", "" ], [ "Yokozaki", "Norimi", "" ] ]
We point out that the anomaly of the muon $g-2$ can be easily explained in a focus point supersymmetry scenario, which realizes the semi-natural supersymmetry. Among known focus point supersymmetry scenarios, we find that a model based on Higgs-gaugino mediation works with a mild fine-tuning $\Delta=40$-$80$. We propose two new focus point supersymmetry scenarios where the anomaly of the muon $g-2$ is also explained. These scenarios are variants of the widely known focus point supersymmetry based on gravity mediation with universal scalar masses.
1507.07758
Fernando Navarra
F. Carvalho, V.P. Gon\c{c}alves, D. Spiering and F.S. Navarra
Gluon saturation and Feynman scaling in leading neutron production
10 pages, 5 figures
null
10.1016/j.physletb.2015.11.017
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we extend the color dipole formalism to the study of leading neutron production in $e + p \rightarrow e + n + X$ collisions at high energies and estimate the related observables, which were measured at HERA and may be analysed in future electron-proton ($ep$) colliders. In particular, we calculate the Feynman $x_F$ distribution of leading neutrons, which is expressed in terms of the pion flux and the photon-pion total cross section. In the color dipole formalism, the photon-pion cross section is described in terms of the dipole-pion scattering amplitude, which contains information about the QCD dynamics at high energies and gluon saturation effects. We consider different models for the scattering amplitude, which have been used to describe the inclusive and diffractive $ep$ HERA data. Moreover, the model dependence of our predictions with the description of the pion flux is analysed in detail. We show that the recently released H1 leading neutron spectra can be reproduced using the color dipole formalism and that these spectra could help us to observe more clearly gluon saturation effects in future $ep$ colliders.
[ { "created": "Tue, 28 Jul 2015 13:22:56 GMT", "version": "v1" } ]
2015-11-25
[ [ "Carvalho", "F.", "" ], [ "Gonçalves", "V. P.", "" ], [ "Spiering", "D.", "" ], [ "Navarra", "F. S.", "" ] ]
In this paper we extend the color dipole formalism to the study of leading neutron production in $e + p \rightarrow e + n + X$ collisions at high energies and estimate the related observables, which were measured at HERA and may be analysed in future electron-proton ($ep$) colliders. In particular, we calculate the Feynman $x_F$ distribution of leading neutrons, which is expressed in terms of the pion flux and the photon-pion total cross section. In the color dipole formalism, the photon-pion cross section is described in terms of the dipole-pion scattering amplitude, which contains information about the QCD dynamics at high energies and gluon saturation effects. We consider different models for the scattering amplitude, which have been used to describe the inclusive and diffractive $ep$ HERA data. Moreover, the model dependence of our predictions with the description of the pion flux is analysed in detail. We show that the recently released H1 leading neutron spectra can be reproduced using the color dipole formalism and that these spectra could help us to observe more clearly gluon saturation effects in future $ep$ colliders.
hep-ph/0412095
Igor Shovkovy
C. Greiner, P. Koch-Steinheimer, F. M. Liu, I. A. Shovkovy and H. Stoecker
Chemical equilibration due to heavy Hagedorn states
9 pages, 2 figures. Invited talk given at 8th International Conference on Strangeness in Quark Matter (SQM2004), Cape Town, South Africa, 15-20 September 2004
J.Phys. G31 (2005) S725-S732
10.1088/0954-3899/31/6/013
null
hep-ph nucl-ex nucl-th
null
A scenario of heavy resonances, called massive Hagedorn states, is proposed which exhibits a fast ($t\approx 1$ fm/c) chemical equilibration of (strange) baryons and anti-baryons at the QCD critical temperature $T_c$. For relativistic heavy ion collisions this scenario predicts that hadronization is followed by a brief expansion phase during which the equilibration rate is higher than the expansion rate, so that baryons and antibaryons reach chemical equilibrium before chemical freeze-out occurs.
[ { "created": "Tue, 7 Dec 2004 14:00:51 GMT", "version": "v1" } ]
2007-05-23
[ [ "Greiner", "C.", "" ], [ "Koch-Steinheimer", "P.", "" ], [ "Liu", "F. M.", "" ], [ "Shovkovy", "I. A.", "" ], [ "Stoecker", "H.", "" ] ]
A scenario of heavy resonances, called massive Hagedorn states, is proposed which exhibits a fast ($t\approx 1$ fm/c) chemical equilibration of (strange) baryons and anti-baryons at the QCD critical temperature $T_c$. For relativistic heavy ion collisions this scenario predicts that hadronization is followed by a brief expansion phase during which the equilibration rate is higher than the expansion rate, so that baryons and antibaryons reach chemical equilibrium before chemical freeze-out occurs.
2012.15256
Rathin Adhikari
Imtiyaz Ahmad Bhat, Girish Kumar Chakravarty, Rathin Adhikari
Inflation, reheating, leptogenesis and bounds on soft supersymmetry breaking parameters
14 pages, 5 figures
null
null
null
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
In the no-scale supergravity with Type-I Seesaw model of Non-minimal supersymmetric standard model (NMSSM), we have analysed inflation, reheating and leptogenesis. A no-scale supergravity realization of Starobinsky model of inflation in simple Wess-Zumino model have been shown earlier by Ellis et al. Here we show a no-scale supergravity realization of Starobinsky model of inflation in Type-I Seesaw framework of NMSSM. In this framework an appropriate choice of no-scale K\"ahler potential results in Starobinsky like plateau inflation along a Higgs-sneutrino $D$-flat direction consistent with the CMB observations. In leptogenesis, the soft-breaking trilinear and bilinear terms play important role. Using conditions for non-thermal contribution to $CP$ asymmetry and successful leptogenesis together with the appropriate reheating at the end of inflation, we have obtained important constraints on the soft supersymmetry breaking parameters.
[ { "created": "Wed, 30 Dec 2020 18:05:20 GMT", "version": "v1" } ]
2021-01-01
[ [ "Bhat", "Imtiyaz Ahmad", "" ], [ "Chakravarty", "Girish Kumar", "" ], [ "Adhikari", "Rathin", "" ] ]
In the no-scale supergravity with Type-I Seesaw model of Non-minimal supersymmetric standard model (NMSSM), we have analysed inflation, reheating and leptogenesis. A no-scale supergravity realization of Starobinsky model of inflation in simple Wess-Zumino model have been shown earlier by Ellis et al. Here we show a no-scale supergravity realization of Starobinsky model of inflation in Type-I Seesaw framework of NMSSM. In this framework an appropriate choice of no-scale K\"ahler potential results in Starobinsky like plateau inflation along a Higgs-sneutrino $D$-flat direction consistent with the CMB observations. In leptogenesis, the soft-breaking trilinear and bilinear terms play important role. Using conditions for non-thermal contribution to $CP$ asymmetry and successful leptogenesis together with the appropriate reheating at the end of inflation, we have obtained important constraints on the soft supersymmetry breaking parameters.
hep-ph/0012212
Ahmed Ali
A. Ali (DESY), A.Ya. Parkhomenko (Yaroslavl State U.)
The $\eta^\prime g^* g^*$ vertex with arbitrary gluon virtualities in the perturbative QCD hard scattering approach
23 pages, 19 figures (requires revtex4, amssymb, epsf); several typos corrected, this version now identical to the one accepted for publication in Phys. Rev. D
Phys.Rev.D65:074020,2002
10.1103/PhysRevD.65.074020
DESY 00-093, YARU-HE-00-05 (December 2000)
hep-ph
null
We study the $\eta^\prime g^* g^*$ vertex for arbitrary gluon virtualities in the time-like and space-like regions, using the perturbative QCD hard scattering approach and an input wave-function of the $\eta^\prime$-meson consistent with the measured $\eta^\prime \gamma^* \gamma$ transition form factor. The contribution of the gluonic content of the $\eta^\prime$-meson is taken into account, enhancing the form factor over the entire virtuality considered. However, data on the electromagnetic transition form factor of the $\eta^\prime$-meson is not sufficient to quantify the gluonic enhancement. We also study the effect of the transverse momenta of the partons in the $\eta^\prime$-meson on the $\eta^\prime g^* g^*$ vertex, using the modified hard scattering approach based on Sudakov formalism. Analytic expressions for the $\eta^\prime g^* g^*$ vertex are presented in limiting kinematic regions and parametrizations are given satisfying the QCD anomaly, for real gluons, and perturbative QCD behavior for large gluon virtualities, in both the time-like and space-like regions. Our results have implications for the inclusive decay $B \to \eta^\prime X$ and exclusive decays, such as $B \to \eta^\prime (K,K^*)$, and in hadronic production processes $N + N (\bar N) \to \eta^\prime X$.
[ { "created": "Sun, 17 Dec 2000 19:04:55 GMT", "version": "v1" }, { "created": "Thu, 15 Nov 2001 11:12:45 GMT", "version": "v2" }, { "created": "Tue, 4 Dec 2001 13:31:02 GMT", "version": "v3" } ]
2009-08-25
[ [ "Ali", "A.", "", "DESY" ], [ "Parkhomenko", "A. Ya.", "", "Yaroslavl State U." ] ]
We study the $\eta^\prime g^* g^*$ vertex for arbitrary gluon virtualities in the time-like and space-like regions, using the perturbative QCD hard scattering approach and an input wave-function of the $\eta^\prime$-meson consistent with the measured $\eta^\prime \gamma^* \gamma$ transition form factor. The contribution of the gluonic content of the $\eta^\prime$-meson is taken into account, enhancing the form factor over the entire virtuality considered. However, data on the electromagnetic transition form factor of the $\eta^\prime$-meson is not sufficient to quantify the gluonic enhancement. We also study the effect of the transverse momenta of the partons in the $\eta^\prime$-meson on the $\eta^\prime g^* g^*$ vertex, using the modified hard scattering approach based on Sudakov formalism. Analytic expressions for the $\eta^\prime g^* g^*$ vertex are presented in limiting kinematic regions and parametrizations are given satisfying the QCD anomaly, for real gluons, and perturbative QCD behavior for large gluon virtualities, in both the time-like and space-like regions. Our results have implications for the inclusive decay $B \to \eta^\prime X$ and exclusive decays, such as $B \to \eta^\prime (K,K^*)$, and in hadronic production processes $N + N (\bar N) \to \eta^\prime X$.
1912.00305
Ricardo Farias
William R. Tavares, Ricardo L. S. Farias and Sidney S. Avancini
Deconfinement and chiral phase transitions in quark matter with a strong electric field
10 pages, 13 figures, replaced with updated version matching the published one
Phys. Rev. D 101, 016017 (2020)
10.1103/PhysRevD.101.016017
null
hep-ph hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The deconfinement and chiral phase transitions are studied in the context of the electrized quark matter at finite temperature in the two-flavor Polyakov-Nambu--Jona-Lasinio model. Using the mean field approximation and an electric field independet regularization we show that the effect of temperature and/or electric fields is to partially restore the chiral symmetry. The deconfinement phase transition is slightly affected by the magnitude of the electric field. To this end we show how the effective quark masses and the expectation value of the Polyakov Loop are affected by the electric fields at finite temperatures. As a very interesting result, the pseudocritical temperatures for chiral symmetry restoration and deconfinement decrease as we increase the magnitude of the electric fields, however, both start to increase after some critical value of the electric field.
[ { "created": "Sun, 1 Dec 2019 02:34:39 GMT", "version": "v1" }, { "created": "Thu, 13 Feb 2020 18:53:48 GMT", "version": "v2" } ]
2020-02-14
[ [ "Tavares", "William R.", "" ], [ "Farias", "Ricardo L. S.", "" ], [ "Avancini", "Sidney S.", "" ] ]
The deconfinement and chiral phase transitions are studied in the context of the electrized quark matter at finite temperature in the two-flavor Polyakov-Nambu--Jona-Lasinio model. Using the mean field approximation and an electric field independet regularization we show that the effect of temperature and/or electric fields is to partially restore the chiral symmetry. The deconfinement phase transition is slightly affected by the magnitude of the electric field. To this end we show how the effective quark masses and the expectation value of the Polyakov Loop are affected by the electric fields at finite temperatures. As a very interesting result, the pseudocritical temperatures for chiral symmetry restoration and deconfinement decrease as we increase the magnitude of the electric fields, however, both start to increase after some critical value of the electric field.
2312.12963
Francesco Sannino
Oleg Antipin, Jahmall Bersini, Pantelis Panopoulos, Francesco Sannino, Zhi-Wei Wang
Infinite order results for charged sectors of the Standard Model
27 pages in LaTeX
null
null
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
We determine anomalous dimensions of a family of fixed hypercharge operators in the Standard Model featuring the general Cabibbo-Kobayashi-Maskawa structure. The results are obtained at infinite orders in the couplings and to leading and subleading orders in the charge. The computed anomalous dimensions are shown to agree with the maximum known order in perturbation theory. We further show that the large hypercharge sector of the Standard Model is characterised by a non-Abelian vector condensation phase.
[ { "created": "Wed, 20 Dec 2023 12:07:20 GMT", "version": "v1" } ]
2023-12-21
[ [ "Antipin", "Oleg", "" ], [ "Bersini", "Jahmall", "" ], [ "Panopoulos", "Pantelis", "" ], [ "Sannino", "Francesco", "" ], [ "Wang", "Zhi-Wei", "" ] ]
We determine anomalous dimensions of a family of fixed hypercharge operators in the Standard Model featuring the general Cabibbo-Kobayashi-Maskawa structure. The results are obtained at infinite orders in the couplings and to leading and subleading orders in the charge. The computed anomalous dimensions are shown to agree with the maximum known order in perturbation theory. We further show that the large hypercharge sector of the Standard Model is characterised by a non-Abelian vector condensation phase.
hep-ph/0405050
Rogerio Rosenfeld
A. Chalov, A. Likhoded and R. Rosenfeld
Constraints on a scalar-pseudoscalar Higgs mixing at future e+e- colliders: an update
3 pages, 2 figures, to be submitted to Phys. Rev. D
Phys.Rev. D70 (2004) 037505
10.1103/PhysRevD.70.037505
null
hep-ph
null
We perform an update of our previous analysis on the constraints on possible deviations of Hbb coupling from its Standard Model value, arising from a scalar-pseudoscalar mixing. In this paper we include a complete simulation of the process e+ e- -> b bbar e+ e- and combine it with our previous results to obtain tighter bounds on the deviations of the parameters describing this coupling that could be measured at the Next Linear Collider.
[ { "created": "Thu, 6 May 2004 13:17:47 GMT", "version": "v1" } ]
2009-11-10
[ [ "Chalov", "A.", "" ], [ "Likhoded", "A.", "" ], [ "Rosenfeld", "R.", "" ] ]
We perform an update of our previous analysis on the constraints on possible deviations of Hbb coupling from its Standard Model value, arising from a scalar-pseudoscalar mixing. In this paper we include a complete simulation of the process e+ e- -> b bbar e+ e- and combine it with our previous results to obtain tighter bounds on the deviations of the parameters describing this coupling that could be measured at the Next Linear Collider.
2404.18951
Alessandro D.A.M. Spallicci di Filottrano
Alessandro D.A.M. Spallicci, Abedennour Dib, Jos\'e A. Helay\"el-Neto
Photon frequency variation in non-linear electro-magnetism
null
2024, Phys. Lett. B, 855, 138873
10.1016/j.physletb.2024.138773
null
hep-ph astro-ph.CO gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
We set a generalised non-linear Lagrangian, encompassing Born-Infeld and Heisenberg-Euler theories among others. The Lagrangian reduces to the Maxwell Lagrangian at lowest order. The field is composed by a propagating light-wave in an electro-magnetic background. The wave exhibits energy variation when the background is space-time dependent. In the photon description, this implies a red or a blue shift, like what we obtained in massive theories, as the de Broglie-Proca or effective mass theories as the Standard-Model Extension under Lorentz symmetry violation. The two results, photon energy-conservation and the frequency shift are instead new for non-linear electro-magnetism. We conclude by discussing how these static frequency shifts when added to the expansion red shift allow new interpretations in cosmology or for atomic spectra. We finally consider the consequences on the Poincar\'e symmetry.
[ { "created": "Sat, 27 Apr 2024 12:52:25 GMT", "version": "v1" } ]
2024-06-27
[ [ "Spallicci", "Alessandro D. A. M.", "" ], [ "Dib", "Abedennour", "" ], [ "Helayël-Neto", "José A.", "" ] ]
We set a generalised non-linear Lagrangian, encompassing Born-Infeld and Heisenberg-Euler theories among others. The Lagrangian reduces to the Maxwell Lagrangian at lowest order. The field is composed by a propagating light-wave in an electro-magnetic background. The wave exhibits energy variation when the background is space-time dependent. In the photon description, this implies a red or a blue shift, like what we obtained in massive theories, as the de Broglie-Proca or effective mass theories as the Standard-Model Extension under Lorentz symmetry violation. The two results, photon energy-conservation and the frequency shift are instead new for non-linear electro-magnetism. We conclude by discussing how these static frequency shifts when added to the expansion red shift allow new interpretations in cosmology or for atomic spectra. We finally consider the consequences on the Poincar\'e symmetry.
hep-ph/9811234
Marc Sher
Shuquan Nie and Marc Sher
Vacuum Stability Bounds in the Two-Higgs Doublet Model
8 pages, 4 figures
Phys.Lett. B449 (1999) 89-92
10.1016/S0370-2693(99)00019-2
WM-98-118
hep-ph
null
In the standard model, the requirements of vacuum stability and the validity of perturbation theory up to the unification scale force the mass of the Higgs boson to be approximately between 130 GeV and 180 GeV. We re-examine these requirements in the (non-supersymmetric) two-Higgs doublet model, in the light of the large top quark mass, and constrain the masses of the Higgs bosons in this model. It is found that the mass of the charged Higgs boson must be lighter than 150 GeV. This bound is below the lower bound in the popular model-II two-Higgs doublet model, and thus we conclude that this model cannot be valid up to the unification scale. The bounds on the neutral Higgs scalars are also discussed.
[ { "created": "Tue, 3 Nov 1998 16:23:20 GMT", "version": "v1" } ]
2009-10-31
[ [ "Nie", "Shuquan", "" ], [ "Sher", "Marc", "" ] ]
In the standard model, the requirements of vacuum stability and the validity of perturbation theory up to the unification scale force the mass of the Higgs boson to be approximately between 130 GeV and 180 GeV. We re-examine these requirements in the (non-supersymmetric) two-Higgs doublet model, in the light of the large top quark mass, and constrain the masses of the Higgs bosons in this model. It is found that the mass of the charged Higgs boson must be lighter than 150 GeV. This bound is below the lower bound in the popular model-II two-Higgs doublet model, and thus we conclude that this model cannot be valid up to the unification scale. The bounds on the neutral Higgs scalars are also discussed.
1708.08057
Aleksander Kusina
A. Kusina
TMD splitting functions and the corresponding evolution equation
Presented at 25th International Workshop on Deep Inelastic Scattering and Related Topics, 3-7 April 2017, Birmingham, UK
PoS(DIS2017)049
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We generalize the Catani Hautmann formalism to calculate the Pgq and Pqq transverse momentum dependent splitting functions. Then we use the obtained Pgq kernel to construct a low-x evolution equation for gluons that takes into account the effect of non-diagonal quark-to-gluon splittings. In order to write down a consistent equation we resum virtual corrections coming from the gluon channel and demonstrate that this implies a suitable regularization of the Pgq singularity, corresponding to a soft emitted quark. We also note that the obtained equation is in a straightforward manner generalized to a nonlinear evolution equation which takes into account effects due to the presence of high gluon densities.
[ { "created": "Sun, 27 Aug 2017 06:54:20 GMT", "version": "v1" } ]
2017-08-29
[ [ "Kusina", "A.", "" ] ]
We generalize the Catani Hautmann formalism to calculate the Pgq and Pqq transverse momentum dependent splitting functions. Then we use the obtained Pgq kernel to construct a low-x evolution equation for gluons that takes into account the effect of non-diagonal quark-to-gluon splittings. In order to write down a consistent equation we resum virtual corrections coming from the gluon channel and demonstrate that this implies a suitable regularization of the Pgq singularity, corresponding to a soft emitted quark. We also note that the obtained equation is in a straightforward manner generalized to a nonlinear evolution equation which takes into account effects due to the presence of high gluon densities.
hep-ph/0010164
Markus H. Thoma
Markus H. Thoma
New Developments and Applications of Thermal Field Theory
46 pages, 38 figures, Lecture notes of the Jyvaskyla Summer School 2000
null
null
null
hep-ph nucl-th
null
The lecture provides an introduction to thermal field theory and its applications to the physics of the quark-gluon plasma, possibly created in relativistic heavy ion collisions. In particular the Hard Thermal Loop resummation technique, providing a consistent perturbative description of relativistic, high-temperature plasmas is introduced. Using this method interesting quantities of the quark-gluon plasma (damping rates, energy loss, photon and dilepton production) are discussed. Furthermore recent developments on non-equilibrium field theory, which are relevant for high-energy heavy ion physics, are presented.
[ { "created": "Mon, 16 Oct 2000 15:07:19 GMT", "version": "v1" } ]
2007-05-23
[ [ "Thoma", "Markus H.", "" ] ]
The lecture provides an introduction to thermal field theory and its applications to the physics of the quark-gluon plasma, possibly created in relativistic heavy ion collisions. In particular the Hard Thermal Loop resummation technique, providing a consistent perturbative description of relativistic, high-temperature plasmas is introduced. Using this method interesting quantities of the quark-gluon plasma (damping rates, energy loss, photon and dilepton production) are discussed. Furthermore recent developments on non-equilibrium field theory, which are relevant for high-energy heavy ion physics, are presented.
1005.5683
Pere Masjuan
Pere Masjuan
Rational Approximations in Quantum Chromodynamics
Ph.D. Thesis (Advisor: Santi Peris). 174 pages
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss some topics concerning rational approximations in Quantum Chromodynamics, especially those related with the mathematical theory of Pad\'e Approximants. We focus on two kind of problems: the first one related with meromorphic functions (inspired by the Large-Nc limit in QCD) where we explore the Minimal Hadronic Approximation through the extraction of Low-Energy Constants and Condensate parameters of a two-point Green's function; and the second one related with meromorphic functions of Stieltjes-type where we present a critical analysis to a unitarization process applied to the Linear Sigma Model and also and application of the Pad\'e Theory to the vacuum polarization function of a heavy quark. We also show the ability of these approximations when working with experimental data. Along these line, we make special emphasis on the reliability of that theory to control on systematic errors.
[ { "created": "Mon, 31 May 2010 13:50:02 GMT", "version": "v1" }, { "created": "Tue, 1 Jun 2010 11:21:20 GMT", "version": "v2" }, { "created": "Tue, 26 Oct 2010 13:22:35 GMT", "version": "v3" } ]
2010-10-27
[ [ "Masjuan", "Pere", "" ] ]
We discuss some topics concerning rational approximations in Quantum Chromodynamics, especially those related with the mathematical theory of Pad\'e Approximants. We focus on two kind of problems: the first one related with meromorphic functions (inspired by the Large-Nc limit in QCD) where we explore the Minimal Hadronic Approximation through the extraction of Low-Energy Constants and Condensate parameters of a two-point Green's function; and the second one related with meromorphic functions of Stieltjes-type where we present a critical analysis to a unitarization process applied to the Linear Sigma Model and also and application of the Pad\'e Theory to the vacuum polarization function of a heavy quark. We also show the ability of these approximations when working with experimental data. Along these line, we make special emphasis on the reliability of that theory to control on systematic errors.
1210.6755
Muhammad Shahid
Renata Jora, Joseph Schechter and M. Naeem Shahid
Naturally perturbed S$_3$ neutrinos
10 pages, 2 figures
null
10.1142/S0217751X13500280
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We simplify and extend our previous model for the masses and mixing matrix of three Majorana neutrinos based on permutation symmetry $S_3$ and the perturbations which violate this symmetry. The perturbations are arranged such that we get the smaller solar neutrinos mass difference at second order. We work out the corrections to the tribimaximal mixing matrix with the non-zero value for $s_{13}$ and the conventional CP-violating phase. It is shown that the results of the model are comparable with the global analysis of neutrino oscillation data.
[ { "created": "Thu, 25 Oct 2012 08:19:36 GMT", "version": "v1" }, { "created": "Sun, 7 Apr 2013 20:52:54 GMT", "version": "v2" } ]
2013-04-09
[ [ "Jora", "Renata", "" ], [ "Schechter", "Joseph", "" ], [ "Shahid", "M. Naeem", "" ] ]
We simplify and extend our previous model for the masses and mixing matrix of three Majorana neutrinos based on permutation symmetry $S_3$ and the perturbations which violate this symmetry. The perturbations are arranged such that we get the smaller solar neutrinos mass difference at second order. We work out the corrections to the tribimaximal mixing matrix with the non-zero value for $s_{13}$ and the conventional CP-violating phase. It is shown that the results of the model are comparable with the global analysis of neutrino oscillation data.
0910.3437
Christian Sturm
Christian Sturm
Improving the precision of light quark mass determinations
5 pages, 3 figures, to be published in the proceedings of DPF-2009, Detroit, MI, July 2009, eConf C090726
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the concepts and the framework of the renormalization procedure in regularization-invariant momentum subtraction schemes. These schemes are used in the context of lattice simulations for the determination of physical quantities like light quark masses. We focus on the renormalization procedure with a symmetric subtraction point of a quark mass and discuss its conversion from the RI/SMOM scheme to the MSbar scheme. A symmetric subtraction point allows for a lattice calculation with a reduced contamination from infrared effects. The perturbative series for the resulting matching factor at next-to-leading order is better behaved for the symmetric momentum configuration than for the exceptional one which can decrease the uncertainty in light quark mass determinations.
[ { "created": "Mon, 19 Oct 2009 01:01:46 GMT", "version": "v1" } ]
2009-10-20
[ [ "Sturm", "Christian", "" ] ]
We discuss the concepts and the framework of the renormalization procedure in regularization-invariant momentum subtraction schemes. These schemes are used in the context of lattice simulations for the determination of physical quantities like light quark masses. We focus on the renormalization procedure with a symmetric subtraction point of a quark mass and discuss its conversion from the RI/SMOM scheme to the MSbar scheme. A symmetric subtraction point allows for a lattice calculation with a reduced contamination from infrared effects. The perturbative series for the resulting matching factor at next-to-leading order is better behaved for the symmetric momentum configuration than for the exceptional one which can decrease the uncertainty in light quark mass determinations.
1609.00797
Hong-Shi Zong
Cui-Bai Luo, Song Shi, Yi-Lun Du, Yong-Long Wang and Hong-Shi Zong
Discussion on Lorentz Invariance Violation of Non-commutative Field Theory and Neutrino Oscillation
null
null
10.1142/S0217751X17500403
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Depending on deformed canonical anti-commutation relations, massless neutrino oscillation based on Lorentz invariance violation in non-commutative field theory is discussed. It is found that the previous studies about massless neutrino oscillation within deformed canonical anti-commutation relations should satisfy the condition of new Moyal product and new non standard commutation relations. Furthermore, comparing the Lorentz Invariant Violation parameters $\mathit{A}$ in the previous studies with new Moyal product and new non standard commutation relations, we find that the orders of magnitude of non-commutative parameters (Lorentz invariant Violation parameters $\mathit{A}$) is not self-consistent. This inconsistency means that the previous studies of Lorentz invariance violation in non-commutative field theory may not naturally explain massless neutrino oscillation. In other words, it should be impossible to explain neutrino oscillation by Lorentz invariance violation in non-commutative field theory. This conclusion is supported by the latest atmospheric neutrinos experimental results from the Super-Kamiokande Collaboration, which show that no evidence of Lorentz invariance violation on atmospheric neutrinos was observed.
[ { "created": "Sat, 3 Sep 2016 06:26:57 GMT", "version": "v1" }, { "created": "Fri, 23 Sep 2016 08:04:33 GMT", "version": "v2" }, { "created": "Mon, 7 Nov 2016 09:07:47 GMT", "version": "v3" }, { "created": "Tue, 8 Nov 2016 09:26:26 GMT", "version": "v4" }, { "crea...
2017-04-05
[ [ "Luo", "Cui-Bai", "" ], [ "Shi", "Song", "" ], [ "Du", "Yi-Lun", "" ], [ "Wang", "Yong-Long", "" ], [ "Zong", "Hong-Shi", "" ] ]
Depending on deformed canonical anti-commutation relations, massless neutrino oscillation based on Lorentz invariance violation in non-commutative field theory is discussed. It is found that the previous studies about massless neutrino oscillation within deformed canonical anti-commutation relations should satisfy the condition of new Moyal product and new non standard commutation relations. Furthermore, comparing the Lorentz Invariant Violation parameters $\mathit{A}$ in the previous studies with new Moyal product and new non standard commutation relations, we find that the orders of magnitude of non-commutative parameters (Lorentz invariant Violation parameters $\mathit{A}$) is not self-consistent. This inconsistency means that the previous studies of Lorentz invariance violation in non-commutative field theory may not naturally explain massless neutrino oscillation. In other words, it should be impossible to explain neutrino oscillation by Lorentz invariance violation in non-commutative field theory. This conclusion is supported by the latest atmospheric neutrinos experimental results from the Super-Kamiokande Collaboration, which show that no evidence of Lorentz invariance violation on atmospheric neutrinos was observed.
1411.3161
Wolfgang Altmannshofer
Wolfgang Altmannshofer, David M. Straub
New physics in $b\to s$ transitions after LHC run 1
49 pages, 12 figures. v4: matches version published in EPJC
null
10.1140/epjc/s10052-015-3602-7
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present results of global fits of all relevant experimental data on rare $b \to s$ decays. We observe significant tensions between the Standard Model predictions and the data. After critically reviewing the possible sources of theoretical uncertainties, we find that within the Standard Model, the tensions could be explained if there are unaccounted hadronic effects much larger than our estimates. Assuming hadronic uncertainties are estimated in a sufficiently conservative way, we discuss the implications of the experimental results on new physics, both model independently as well as in the context of the minimal supersymmetric standard model and models with flavour-changing $Z'$ bosons. We discuss in detail the violation of lepton flavour universality as hinted by the current data and make predictions for additional lepton flavour universality tests that can be performed in the future. We find that the ratio of the forward-backward asymmetries in $B \to K^* \mu^+\mu^-$ and $B \to K^* e^+e^-$ at low dilepton invariant mass is a particularly sensitive probe of lepton flavour universality and allows to distinguish between different new physics scenarios that give the best description of the current data.
[ { "created": "Wed, 12 Nov 2014 12:59:08 GMT", "version": "v1" }, { "created": "Mon, 9 Feb 2015 12:31:54 GMT", "version": "v2" }, { "created": "Fri, 8 May 2015 12:36:59 GMT", "version": "v3" }, { "created": "Wed, 19 Aug 2015 19:41:44 GMT", "version": "v4" } ]
2015-09-30
[ [ "Altmannshofer", "Wolfgang", "" ], [ "Straub", "David M.", "" ] ]
We present results of global fits of all relevant experimental data on rare $b \to s$ decays. We observe significant tensions between the Standard Model predictions and the data. After critically reviewing the possible sources of theoretical uncertainties, we find that within the Standard Model, the tensions could be explained if there are unaccounted hadronic effects much larger than our estimates. Assuming hadronic uncertainties are estimated in a sufficiently conservative way, we discuss the implications of the experimental results on new physics, both model independently as well as in the context of the minimal supersymmetric standard model and models with flavour-changing $Z'$ bosons. We discuss in detail the violation of lepton flavour universality as hinted by the current data and make predictions for additional lepton flavour universality tests that can be performed in the future. We find that the ratio of the forward-backward asymmetries in $B \to K^* \mu^+\mu^-$ and $B \to K^* e^+e^-$ at low dilepton invariant mass is a particularly sensitive probe of lepton flavour universality and allows to distinguish between different new physics scenarios that give the best description of the current data.
1211.1880
Paolo Lodone
Francesco Coradeschi and Paolo Lodone
Selection rules for helicity amplitudes in massive gauge theories
18 pages. v2: minor modifications. v3: published version
Phys. Rev. D 87, 074026 (2013)
10.1103/PhysRevD.87.074026
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
After a rediscussion of the vanishing theorems for helicity amplitudes in unbroken gauge theories, we study the case of spontaneously broken gauge theories at high energy. The vanishing theorems generalize to a definite pattern of m/E-suppression of the amplitudes that vanish in the massless case, where E is the energy scale of the process and m is the mass of the gauge vectors. We use only elementary arguments, and as an application we show how these methods can be employed to understand some aspects of the effective W approximation in the polarized case.
[ { "created": "Thu, 8 Nov 2012 15:25:34 GMT", "version": "v1" }, { "created": "Fri, 1 Feb 2013 09:09:24 GMT", "version": "v2" }, { "created": "Sat, 6 Apr 2013 13:16:53 GMT", "version": "v3" } ]
2013-05-30
[ [ "Coradeschi", "Francesco", "" ], [ "Lodone", "Paolo", "" ] ]
After a rediscussion of the vanishing theorems for helicity amplitudes in unbroken gauge theories, we study the case of spontaneously broken gauge theories at high energy. The vanishing theorems generalize to a definite pattern of m/E-suppression of the amplitudes that vanish in the massless case, where E is the energy scale of the process and m is the mass of the gauge vectors. We use only elementary arguments, and as an application we show how these methods can be employed to understand some aspects of the effective W approximation in the polarized case.
hep-ph/9407298
null
Thomas G. Rizzo
Diphoton Production at Hadron Colliders and New Contact Interactions
LaTex, 12pages plus 5 figures(available on request), SLAC-PUB-6579
Phys.Rev. D51 (1995) 1064-1067
10.1103/PhysRevD.51.1064
null
hep-ph
null
We explore the capability of the Tevatron and LHC to place limits on the possible existence of flavor-independent $q \bar q \gamma\gamma$ contact interactions which can lead to an excess of diphoton events with large invariant masses. Assuming no departure from the Standard Model is observed, we show that the Tevatron will eventually be able to place a lower bound of 0.5-0.6 TeV on the scale associated with this new contact interaction. At the LHC, scales as large as 3-6 TeV may be probed with suitable detector cuts and an integrated luminosity of $100 fb^{-1}$.
[ { "created": "Thu, 14 Jul 1994 19:28:51 GMT", "version": "v1" } ]
2009-10-28
[ [ "Rizzo", "Thomas G.", "" ] ]
We explore the capability of the Tevatron and LHC to place limits on the possible existence of flavor-independent $q \bar q \gamma\gamma$ contact interactions which can lead to an excess of diphoton events with large invariant masses. Assuming no departure from the Standard Model is observed, we show that the Tevatron will eventually be able to place a lower bound of 0.5-0.6 TeV on the scale associated with this new contact interaction. At the LHC, scales as large as 3-6 TeV may be probed with suitable detector cuts and an integrated luminosity of $100 fb^{-1}$.
hep-ph/0402079
Sandip Pakvasa
Sandip Pakvasa and Mahiko Suzuki
Broken SU(3) antidecuplet for $\Theta^+$ and $\Xi_{{3/2}}$
14 pages, 4 tables. Some changes in the text made, a section added on mixing with higher SU(3) multiplets, and more references added
Phys.Rev. D70 (2004) 036002
10.1103/PhysRevD.70.036002
null
hep-ph hep-ex
null
If the narrow exotic baryon resonances $\Theta^+(1540)$ and $\Xi_{{3/2}(1862)$ are members of the $J^P = {1/2}1/2^+$ antidecuplet with $N^*(1710)$, the octet-antidecuplet mixing is required not only by the mass spectrum but also by the decay pattern of $N^*(1710)$. This casts doubt on validity of the $\Theta^+$ mass prediciton by the chiral soliton model. While all pieces of the existing experimental information point to a small octet-antidecuplet mixing, the magnitude of mixing required by the mass spectrum is not consistent with the value needed to account for the hadronic decay rates. The discrepancy is not resolved even after the large experimental uncertainty is taken into consideration. We fail to find an alternative SU(3) assignment even with different spin-parity assignment.
[ { "created": "Sat, 7 Feb 2004 23:53:11 GMT", "version": "v1" }, { "created": "Fri, 27 Feb 2004 02:45:42 GMT", "version": "v2" }, { "created": "Wed, 5 May 2004 23:26:10 GMT", "version": "v3" } ]
2009-11-10
[ [ "Pakvasa", "Sandip", "" ], [ "Suzuki", "Mahiko", "" ] ]
If the narrow exotic baryon resonances $\Theta^+(1540)$ and $\Xi_{{3/2}(1862)$ are members of the $J^P = {1/2}1/2^+$ antidecuplet with $N^*(1710)$, the octet-antidecuplet mixing is required not only by the mass spectrum but also by the decay pattern of $N^*(1710)$. This casts doubt on validity of the $\Theta^+$ mass prediciton by the chiral soliton model. While all pieces of the existing experimental information point to a small octet-antidecuplet mixing, the magnitude of mixing required by the mass spectrum is not consistent with the value needed to account for the hadronic decay rates. The discrepancy is not resolved even after the large experimental uncertainty is taken into consideration. We fail to find an alternative SU(3) assignment even with different spin-parity assignment.
0804.4529
Michael Kuchiev
Michael Kuchiev and Victor Flambaum
Vector Bosons in Strong Fields
4 pages, revtex
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Coulomb problem for charged massive vector bosons is known to be unstable, the boson falls on the Coulomb center. It is shown that when the charge of the Coulomb center is smeared over a small but finite volume, then instead of the fall there appears a large series of bound states localized inside the volume containing the Coulomb charge. It is shown also that the fall on the Coulomb center is completely suppressed, when the conventional QED vacuum polarization is taken into account.In gauge theories (SU(2), Standard Model) the renormalizability of a theory may be insufficient to guarantee an absence of the wave function collapse. Another interesting feature: the density of charge of vector bosons can have a ``wrong'' sign.
[ { "created": "Tue, 29 Apr 2008 05:03:18 GMT", "version": "v1" } ]
2008-04-30
[ [ "Kuchiev", "Michael", "" ], [ "Flambaum", "Victor", "" ] ]
The Coulomb problem for charged massive vector bosons is known to be unstable, the boson falls on the Coulomb center. It is shown that when the charge of the Coulomb center is smeared over a small but finite volume, then instead of the fall there appears a large series of bound states localized inside the volume containing the Coulomb charge. It is shown also that the fall on the Coulomb center is completely suppressed, when the conventional QED vacuum polarization is taken into account.In gauge theories (SU(2), Standard Model) the renormalizability of a theory may be insufficient to guarantee an absence of the wave function collapse. Another interesting feature: the density of charge of vector bosons can have a ``wrong'' sign.
hep-ph/9808339
Hermann Schulz
Hermann Schulz
Skeletons and Variation
4 pages RevTeX; talk at the 5th Thermal Field Theory Workshop 1998 at Regensburg, Germany, August 10-14; text around (9), (10) improved
null
null
ITP-UH 16/98
hep-ph
null
Well known from the sixties, the pressure of e.g. massless phi-four theory may be written as a series of 2PI-diagrams (skeletons) with the lines fully dressed. Varying the self-energy Pi in this expression, it turns into a functional U[Y] having a maximum in function space at Y=Pi. There is also the Feynman-Jensen thermal variational principle V[S], a potentially non-perturbative tool. Here actions S are varied. It is shown, through a few formal but exact steps, that the functional U is covered by V. The corresponding special subset of trial actions is made explicit.
[ { "created": "Mon, 17 Aug 1998 12:25:58 GMT", "version": "v1" }, { "created": "Fri, 11 Sep 1998 15:07:06 GMT", "version": "v2" }, { "created": "Thu, 12 Nov 1998 20:03:40 GMT", "version": "v3" } ]
2007-05-23
[ [ "Schulz", "Hermann", "" ] ]
Well known from the sixties, the pressure of e.g. massless phi-four theory may be written as a series of 2PI-diagrams (skeletons) with the lines fully dressed. Varying the self-energy Pi in this expression, it turns into a functional U[Y] having a maximum in function space at Y=Pi. There is also the Feynman-Jensen thermal variational principle V[S], a potentially non-perturbative tool. Here actions S are varied. It is shown, through a few formal but exact steps, that the functional U is covered by V. The corresponding special subset of trial actions is made explicit.
1411.5243
Guy F. de T\'eramond
Guy F. de Teramond, Hans Gunter Dosch, Stanley J. Brodsky
Baryon Spectrum from Superconformal Quantum Mechanics and its Light-Front Holographic Embedding
31 pages, 1 figure, added references and few minor changes
Phys. Rev. D 91, 045040 (2015)
10.1103/PhysRevD.91.045040
SLAC-PUB-16130
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We describe the observed light-baryon spectrum by extending superconformal quantum mechanics to the light front and its embedding in AdS space. This procedure uniquely determines the confinement potential for arbitrary half-integer spin. To this end, we show that fermionic wave equations in AdS space are dual to light-front supersymmetric quantum mechanical bound-state equations in physical space-time. The specific breaking of conformal invariance explains hadronic properties common to light mesons and baryons, such as the observed mass pattern in the radial and orbital excitations, from the spectrum generating algebra. The holographic embedding in AdS also explains distinctive and systematic features, such as the spin-$J$ degeneracy for states with the same orbital angular momentum, observed in the light baryon spectrum.
[ { "created": "Wed, 19 Nov 2014 14:50:16 GMT", "version": "v1" }, { "created": "Sun, 30 Nov 2014 22:15:06 GMT", "version": "v2" } ]
2015-03-03
[ [ "de Teramond", "Guy F.", "" ], [ "Dosch", "Hans Gunter", "" ], [ "Brodsky", "Stanley J.", "" ] ]
We describe the observed light-baryon spectrum by extending superconformal quantum mechanics to the light front and its embedding in AdS space. This procedure uniquely determines the confinement potential for arbitrary half-integer spin. To this end, we show that fermionic wave equations in AdS space are dual to light-front supersymmetric quantum mechanical bound-state equations in physical space-time. The specific breaking of conformal invariance explains hadronic properties common to light mesons and baryons, such as the observed mass pattern in the radial and orbital excitations, from the spectrum generating algebra. The holographic embedding in AdS also explains distinctive and systematic features, such as the spin-$J$ degeneracy for states with the same orbital angular momentum, observed in the light baryon spectrum.
2004.00748
Daniel Wiegand
Radja Boughezal, Frank Petriello and Daniel Wiegand
Removing flat directions in SMEFT fits: how polarized electron-ion collider data can complement the LHC
24 pages, 13 figures
Phys. Rev. D 101, 116002 (2020)
10.1103/PhysRevD.101.116002
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the potential of future Electron-Ion Collider (EIC) data to probe four-fermion operators in the Standard Model Effective Field Theory (SMEFT). The ability to perform measurements with both polarized electron and proton beams at the EIC provides a powerful tool that can disentangle the effects from different SMEFT operators. We compare the potential constraints from an EIC with those obtained from Drell-Yan data at the Large Hadron Collider. We show that EIC data plays an important complementary role since it probes combinations of Wilson coefficients not accessible through available Drell-Yan measurements.
[ { "created": "Thu, 2 Apr 2020 00:08:58 GMT", "version": "v1" }, { "created": "Wed, 11 Aug 2021 14:44:39 GMT", "version": "v2" } ]
2021-08-12
[ [ "Boughezal", "Radja", "" ], [ "Petriello", "Frank", "" ], [ "Wiegand", "Daniel", "" ] ]
We study the potential of future Electron-Ion Collider (EIC) data to probe four-fermion operators in the Standard Model Effective Field Theory (SMEFT). The ability to perform measurements with both polarized electron and proton beams at the EIC provides a powerful tool that can disentangle the effects from different SMEFT operators. We compare the potential constraints from an EIC with those obtained from Drell-Yan data at the Large Hadron Collider. We show that EIC data plays an important complementary role since it probes combinations of Wilson coefficients not accessible through available Drell-Yan measurements.
2006.14803
Takeo Moroi
Masahiro Kawasaki, Kazunori Kohri, Takeo Moroi, Kai Murai, Hitoshi Murayama
Big-bang nucleosynthesis with sub-GeV massive decaying particles
28 pages, 11 figures
null
10.1088/1475-7516/2020/12/048
KEK-Cosmo-254, KEK-TH-2214
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the effects of the injections of energetic photon and electron (or positron) on the big-bang nucleosynthesis. We study the photodissociation of light elements in the early Universe paying particular attention to the case that the injection energy is sub-GeV and derive upper bounds on the primordial abundances of the massive decaying particle as a function of its lifetime. We also discuss a solution of the $^7$Li problem in this framework.
[ { "created": "Fri, 26 Jun 2020 05:37:19 GMT", "version": "v1" } ]
2021-01-06
[ [ "Kawasaki", "Masahiro", "" ], [ "Kohri", "Kazunori", "" ], [ "Moroi", "Takeo", "" ], [ "Murai", "Kai", "" ], [ "Murayama", "Hitoshi", "" ] ]
We consider the effects of the injections of energetic photon and electron (or positron) on the big-bang nucleosynthesis. We study the photodissociation of light elements in the early Universe paying particular attention to the case that the injection energy is sub-GeV and derive upper bounds on the primordial abundances of the massive decaying particle as a function of its lifetime. We also discuss a solution of the $^7$Li problem in this framework.
hep-ph/0604024
Steve Geer
S. Geer
Physics at a New Fermilab Proton Driver
12 pages, 4 figures. Presented at the III International Workshop on Neutrino Oscillations in Venice, February 7-10, 2006
null
null
null
hep-ph
null
In 2004, motivated by the recent exciting developments in neutrino physics, the Fermilab Long Range Planning Committee identified a new high intensity Proton Driver as an attractive option for the future. At the end of 2004 the APS ``Study on the Physics of Neutrinos'' concluded that the future U.S. neutrino program should have, as one of its components, ``A proton driver in the megawatt class or above and neutrino superbeam with an appropriate very large detector capable of observing CP violation and measuring the neutrino mass-squared differences and mixing parameters with high precision''. The presently proposed Fermilab Proton Driver is designed to accomplish these goals, and is based on, and would help develop, Linear Collider technology. In this paper the Proton Driver parameters are summarized, and the potential physics program is described.
[ { "created": "Mon, 3 Apr 2006 21:13:21 GMT", "version": "v1" } ]
2007-05-23
[ [ "Geer", "S.", "" ] ]
In 2004, motivated by the recent exciting developments in neutrino physics, the Fermilab Long Range Planning Committee identified a new high intensity Proton Driver as an attractive option for the future. At the end of 2004 the APS ``Study on the Physics of Neutrinos'' concluded that the future U.S. neutrino program should have, as one of its components, ``A proton driver in the megawatt class or above and neutrino superbeam with an appropriate very large detector capable of observing CP violation and measuring the neutrino mass-squared differences and mixing parameters with high precision''. The presently proposed Fermilab Proton Driver is designed to accomplish these goals, and is based on, and would help develop, Linear Collider technology. In this paper the Proton Driver parameters are summarized, and the potential physics program is described.
hep-ph/9602283
Yasuhiro Okada
Yasuhiro Okada (KEK)
Higgs Physics at $e^+e^-$ Linear Colliders
17 pages, 9 figures, talk given at the Workshop on Physics and Experiments with Linear Colliders, Sep. 1995, Morioka-Appi, Japan, also available via anonymous ftp at ftp://ftp.kek.jp/kek/preprints/TH/TH-469
null
null
KEK TH-469, KEK preprint 95-205
hep-ph
null
Prospect of Higgs physics at future $e^+e^-$ linear colliders is reviewed for the weakly-coupled Higgs sector. Several topics related to the determination of various couplings of the Higgs boson in the standard model as well as in the supersymmetric standard modelare discussed.
[ { "created": "Tue, 13 Feb 1996 09:44:04 GMT", "version": "v1" } ]
2007-05-23
[ [ "Okada", "Yasuhiro", "", "KEK" ] ]
Prospect of Higgs physics at future $e^+e^-$ linear colliders is reviewed for the weakly-coupled Higgs sector. Several topics related to the determination of various couplings of the Higgs boson in the standard model as well as in the supersymmetric standard modelare discussed.
0812.1594
Howard E. Haber
Herbi K. Dreiner, Howard E. Haber and Stephen P. Martin
Two-component spinor techniques and Feynman rules for quantum field theory and supersymmetry
313 pages. Version 2 adds 53 pages and 91 references. Version 3 adds 6 pages and 8 references. Version 4 adds 6 pages and 9 references. Version 5 is the version published in Physics Reports. Version 6 adds 2 pages and 3 references and corrects all errors in the published version that have come to the attention of the authors. See https://www.niu.edu/spmartin/spinors/ for errata and other features
Phys.Rept.494:1-196,2010
10.1016/j.physrep.2010.05.002
BN-TH-2008-12 and SCIPP-08/08
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Two-component spinors are the basic ingredients for describing fermions in quantum field theory in four space-time dimensions. We develop and review the techniques of the two-component spinor formalism and provide a complete set of Feynman rules for fermions using two-component spinor notation. These rules are suitable for practical calculations of cross-sections, decay rates, and radiative corrections in the Standard Model and its extensions, including supersymmetry, and many explicit examples are provided. The unified treatment presented in this review applies to massless Weyl fermions and massive Dirac and Majorana fermions. We exhibit the relation between the two-component spinor formalism and the more traditional four-component spinor formalism, and indicate their connections to the spinor helicity method and techniques for the computation of helicity amplitudes.
[ { "created": "Tue, 9 Dec 2008 20:49:40 GMT", "version": "v1" }, { "created": "Thu, 10 Sep 2009 17:51:41 GMT", "version": "v2" }, { "created": "Tue, 13 Oct 2009 08:26:05 GMT", "version": "v3" }, { "created": "Thu, 3 Dec 2009 07:05:58 GMT", "version": "v4" }, { "cre...
2022-05-25
[ [ "Dreiner", "Herbi K.", "" ], [ "Haber", "Howard E.", "" ], [ "Martin", "Stephen P.", "" ] ]
Two-component spinors are the basic ingredients for describing fermions in quantum field theory in four space-time dimensions. We develop and review the techniques of the two-component spinor formalism and provide a complete set of Feynman rules for fermions using two-component spinor notation. These rules are suitable for practical calculations of cross-sections, decay rates, and radiative corrections in the Standard Model and its extensions, including supersymmetry, and many explicit examples are provided. The unified treatment presented in this review applies to massless Weyl fermions and massive Dirac and Majorana fermions. We exhibit the relation between the two-component spinor formalism and the more traditional four-component spinor formalism, and indicate their connections to the spinor helicity method and techniques for the computation of helicity amplitudes.
2212.11210
Samiran Roy
Roberta Calabrese, Jacob Gunn, Gennaro Miele, Stefano Morisi, Samiran Roy, Pietro Santorelli
Constraining scalar leptoquarks using COHERENT data
9 pages, 4 figures, 2 tables, matches the published version
null
10.1103/PhysRevD.107.055039
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Neutrino-nucleus coherent scattering measurements by the COHERENT collaboration provide us with a unique capability to test various beyond the standard model scenarios. In this work, we constrain scalar leptoquarks (LQs) using the COHERENT data. LQs arise in many extensions of the Standard Model (SM). Generally, the mass of the LQs is assumed to be very high to avoid the bounds from proton decay. However, there are low-scale LQ models which prohibit proton decay by construction. We consider two electroweak doublet scalar LQ models with hypercharge Y=1/6, and Y=7/6 and provide the bounds in the plane of the Yukawa coupling and the mass of LQ. We also compare the bounds on LQs coming from various other experiments and find that the COHERENT one covers a wide range of LQ masses from MeV to TeV and in certain regions the constraints are competitive with the others.
[ { "created": "Wed, 21 Dec 2022 17:34:21 GMT", "version": "v1" }, { "created": "Tue, 28 Mar 2023 17:23:22 GMT", "version": "v2" } ]
2023-03-29
[ [ "Calabrese", "Roberta", "" ], [ "Gunn", "Jacob", "" ], [ "Miele", "Gennaro", "" ], [ "Morisi", "Stefano", "" ], [ "Roy", "Samiran", "" ], [ "Santorelli", "Pietro", "" ] ]
Neutrino-nucleus coherent scattering measurements by the COHERENT collaboration provide us with a unique capability to test various beyond the standard model scenarios. In this work, we constrain scalar leptoquarks (LQs) using the COHERENT data. LQs arise in many extensions of the Standard Model (SM). Generally, the mass of the LQs is assumed to be very high to avoid the bounds from proton decay. However, there are low-scale LQ models which prohibit proton decay by construction. We consider two electroweak doublet scalar LQ models with hypercharge Y=1/6, and Y=7/6 and provide the bounds in the plane of the Yukawa coupling and the mass of LQ. We also compare the bounds on LQs coming from various other experiments and find that the COHERENT one covers a wide range of LQ masses from MeV to TeV and in certain regions the constraints are competitive with the others.
hep-ph/0301212
Yvonne Wong
Yvonne Y. Y. Wong
T-violation tests for relativity principles
2 pages; Talk given at the 4th NuFact '02 Workshop (Neutrino Factories Based On Muon Storage Rings), 1-6 Jul 2002, London, England; To appear in proceedings
J.Phys.G29:1857-1860,2003
10.1088/0954-3899/29/8/360
null
hep-ph
null
We consider the implications of a violation of the equivalence principle or of Lorentz invariance in the neutrino sector for the T-asymmetry $\Delta P_T \equiv P(\nu_{\alpha} \to \nu_{\beta}) - P(\nu_{\beta} \to \nu_{\alpha})$ in a three-flavour framework. We find that additional mixing due to these mechanisms, while obeying all present bounds, can lead to a substantial enhancement, suppression, and/or sign change in $\Delta P_T$ for the preferred energies and baselines of a neutrino factory. This in turn allows for the possibility of improving existing constraints by several orders of magnitude.
[ { "created": "Thu, 23 Jan 2003 19:48:36 GMT", "version": "v1" } ]
2008-11-26
[ [ "Wong", "Yvonne Y. Y.", "" ] ]
We consider the implications of a violation of the equivalence principle or of Lorentz invariance in the neutrino sector for the T-asymmetry $\Delta P_T \equiv P(\nu_{\alpha} \to \nu_{\beta}) - P(\nu_{\beta} \to \nu_{\alpha})$ in a three-flavour framework. We find that additional mixing due to these mechanisms, while obeying all present bounds, can lead to a substantial enhancement, suppression, and/or sign change in $\Delta P_T$ for the preferred energies and baselines of a neutrino factory. This in turn allows for the possibility of improving existing constraints by several orders of magnitude.
1907.13156
Giulio Salvatori
R. Bonciani, V. Del Duca, H. Frellesvig, J.M. Henn, M. Hidding, L. Maestri, F. Moriello, G. Salvatori, V.A. Smirnov
Evaluating two-loop non-planar master integrals for Higgs + jet production with full heavy-quark mass dependence
null
J. High Energ. Phys. (2020) 2020: 132. https://doi.org/10.1007/JHEP01(2020)132
10.1007/JHEP01(2020)132
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the analytic computation of a family of non-planar master integrals which contribute to the two-loop scattering amplitudes for Higgs plus one jet production, with full heavy-quark mass dependence. These are relevant for the NNLO corrections to inclusive Higgs production and for the NLO corrections to Higgs production in association with a jet, in QCD. The computation of the integrals is performed with the method of differential equations. We provide a choice of basis for the polylogarithmic sectors, that puts the system of differential equations in canonical form. Solutions up to weight 2 are provided in terms of logarithms and dilogarithms, and 1-fold integral solutions are provided at weight 3 and 4. There are two elliptic sectors in the family, which are computed by solving their associated set of differential equations in terms of generalized power series. The resulting series may be truncated to obtain numerical results with high precision. The series solution renders the analytic continuation to the physical region straightforward. Moreover, we show how the series expansion method can be used to obtain accurate numerical results for all the master integrals of the family in all kinematic regions.
[ { "created": "Tue, 30 Jul 2019 18:04:04 GMT", "version": "v1" }, { "created": "Thu, 1 Aug 2019 09:41:08 GMT", "version": "v2" }, { "created": "Fri, 31 Jan 2020 17:16:17 GMT", "version": "v3" } ]
2020-02-03
[ [ "Bonciani", "R.", "" ], [ "Del Duca", "V.", "" ], [ "Frellesvig", "H.", "" ], [ "Henn", "J. M.", "" ], [ "Hidding", "M.", "" ], [ "Maestri", "L.", "" ], [ "Moriello", "F.", "" ], [ "Salvatori", ...
We present the analytic computation of a family of non-planar master integrals which contribute to the two-loop scattering amplitudes for Higgs plus one jet production, with full heavy-quark mass dependence. These are relevant for the NNLO corrections to inclusive Higgs production and for the NLO corrections to Higgs production in association with a jet, in QCD. The computation of the integrals is performed with the method of differential equations. We provide a choice of basis for the polylogarithmic sectors, that puts the system of differential equations in canonical form. Solutions up to weight 2 are provided in terms of logarithms and dilogarithms, and 1-fold integral solutions are provided at weight 3 and 4. There are two elliptic sectors in the family, which are computed by solving their associated set of differential equations in terms of generalized power series. The resulting series may be truncated to obtain numerical results with high precision. The series solution renders the analytic continuation to the physical region straightforward. Moreover, we show how the series expansion method can be used to obtain accurate numerical results for all the master integrals of the family in all kinematic regions.
0706.3801
Werner Rodejohann
A. Blum, R. N. Mohapatra, W. Rodejohann
Inverted Mass Hierarchy from Scaling in the Neutrino Mass Matrix: Low and High Energy Phenomenology
19 pages, 2 figures, comments added, to appear in PRD
Phys.Rev.D76:053003,2007
10.1103/PhysRevD.76.053003
null
hep-ph
null
Best-fit values of recent global analyzes of neutrino data imply large solar neutrino mixing, vanishing U_{e3} and a non-maximal atmospheric neutrino mixing angle theta_{23}. We show that these values emerge naturally by the hypothesis of "scaling" in the Majorana neutrino mass matrix, which states that the ratios of its elements are equal. It also predicts an inverted hierarchy for the neutrino masses. We point out several advantages and distinguishing tests of the scaling hypothesis compared to the L_e - L_mu - L_tau flavor symmetry, which is usually assumed to provide an understanding of the inverted hierarchy. Scenarios which have initially vanishing U_{e3} and maximal atmospheric neutrino mixing are shown to be unlikely to lead to non-maximal theta_{23} while keeping simultaneously U_{e3} zero. We find a peculiar ratio of the branching ratios mu -> e gamma and tau -> e gamma in supersymmetric seesaw frameworks, which only depends on atmospheric neutrino mixing and results in tau -> e gamma being unobservable. The consequences of the scaling hypothesis for high energy astrophysical neutrinos at neutrino telescopes are also investigated. Then we analyze a seesaw model based on the discrete symmetry D_4 times Z_2 leading to scaling in the low energy mass matrix and being capable of generating the baryon asymmetry of the Universe via leptogenesis. The relevant CP phase is identical to the low energy Majorana phase and successful leptogenesis requires an effective mass for neutrinoless double beta decay larger than 0.045 eV.
[ { "created": "Tue, 26 Jun 2007 12:11:09 GMT", "version": "v1" }, { "created": "Fri, 17 Aug 2007 06:41:22 GMT", "version": "v2" } ]
2008-11-26
[ [ "Blum", "A.", "" ], [ "Mohapatra", "R. N.", "" ], [ "Rodejohann", "W.", "" ] ]
Best-fit values of recent global analyzes of neutrino data imply large solar neutrino mixing, vanishing U_{e3} and a non-maximal atmospheric neutrino mixing angle theta_{23}. We show that these values emerge naturally by the hypothesis of "scaling" in the Majorana neutrino mass matrix, which states that the ratios of its elements are equal. It also predicts an inverted hierarchy for the neutrino masses. We point out several advantages and distinguishing tests of the scaling hypothesis compared to the L_e - L_mu - L_tau flavor symmetry, which is usually assumed to provide an understanding of the inverted hierarchy. Scenarios which have initially vanishing U_{e3} and maximal atmospheric neutrino mixing are shown to be unlikely to lead to non-maximal theta_{23} while keeping simultaneously U_{e3} zero. We find a peculiar ratio of the branching ratios mu -> e gamma and tau -> e gamma in supersymmetric seesaw frameworks, which only depends on atmospheric neutrino mixing and results in tau -> e gamma being unobservable. The consequences of the scaling hypothesis for high energy astrophysical neutrinos at neutrino telescopes are also investigated. Then we analyze a seesaw model based on the discrete symmetry D_4 times Z_2 leading to scaling in the low energy mass matrix and being capable of generating the baryon asymmetry of the Universe via leptogenesis. The relevant CP phase is identical to the low energy Majorana phase and successful leptogenesis requires an effective mass for neutrinoless double beta decay larger than 0.045 eV.
hep-ph/0011105
Mikhail Shaposhnikov
Massimo Giovannini and Mikhail Shaposhnikov
Primordial magnetic fields from inflation???
Latex, 3 pages, Contribution to the Proceedings of the Conference on Cosmology and Astroparticle Physics CAPP2000, July 2000, Verbier, Switzerland
null
10.1063/1.1363564
UNIL-IPT-00-26
hep-ph astro-ph
null
In this note we argue that the breaking of conformal invariance because of the coupling of a charged scalar field to gravity is not sufficient for the production of seed galactic magnetic fields during inflation.
[ { "created": "Wed, 8 Nov 2000 09:11:55 GMT", "version": "v1" } ]
2009-10-31
[ [ "Giovannini", "Massimo", "" ], [ "Shaposhnikov", "Mikhail", "" ] ]
In this note we argue that the breaking of conformal invariance because of the coupling of a charged scalar field to gravity is not sufficient for the production of seed galactic magnetic fields during inflation.
1903.00809
J. P. Ma
X.P. Chai, K.B. Chen, J.P. Ma and X.B. Tong
Fracture Functions in Different Kinematic Regions and Their Factorizations
more discussions and equations are added. Published in JHEP
null
10.1007/JHEP10(2019)285
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Fracture functions are parton distributions of an initial hadron in the presence of an almost collinear particle observed in the final state. They are important ingredients in QCD factorization for processes where a particle is produced diffractively. There are different fracture functions for a process in different kinematic regions. We take the production of a lepton pair combined with a diffractively produced particle in hadron collisions to discuss this. Those fracture functions can be factorized further if there are large energy scales involved. They can be factorized with twist-2 parton distribution functions and fragmentation functions. We perform one-loop calculations to illustrate the factorization in the case with the diffractively produced particle as a real photon. Evolution equations of different fracture functions are derived from our explicit calculations. They agree with expectations. These equations can be used for re-summations of large log terms in perturbative expansions.
[ { "created": "Sun, 3 Mar 2019 02:13:16 GMT", "version": "v1" }, { "created": "Mon, 4 Nov 2019 05:54:36 GMT", "version": "v2" } ]
2020-01-08
[ [ "Chai", "X. P.", "" ], [ "Chen", "K. B.", "" ], [ "Ma", "J. P.", "" ], [ "Tong", "X. B.", "" ] ]
Fracture functions are parton distributions of an initial hadron in the presence of an almost collinear particle observed in the final state. They are important ingredients in QCD factorization for processes where a particle is produced diffractively. There are different fracture functions for a process in different kinematic regions. We take the production of a lepton pair combined with a diffractively produced particle in hadron collisions to discuss this. Those fracture functions can be factorized further if there are large energy scales involved. They can be factorized with twist-2 parton distribution functions and fragmentation functions. We perform one-loop calculations to illustrate the factorization in the case with the diffractively produced particle as a real photon. Evolution equations of different fracture functions are derived from our explicit calculations. They agree with expectations. These equations can be used for re-summations of large log terms in perturbative expansions.
1912.09458
Johannes Herms
Johannes Herms, Alejandro Ibarra
Probing multicomponent FIMP scenarios with gamma-ray telescopes
14 pages, 3 figures
null
10.1088/1475-7516/2020/03/026
TUM-HEP 1245/19
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a scenario where the dark sector includes two Feebly Interacting Massive Particles (FIMPs), with couplings to the Standard Model particles that allow their production in the Early Universe via thermal freeze-in. These couplings generically lead to the decay of the heavier dark matter component into the lighter, possibly leading to observable signals of the otherwise elusive FIMPs. Concretely, we argue that the loop induced decay $\psi_2\rightarrow\psi_1\gamma$ for fermionic FIMPs, or $\phi_2\rightarrow\phi_1\gamma\gamma$ for scalar FIMPs, could have detectable rates for model parameters compatible with the observed dark matter abundance.
[ { "created": "Thu, 19 Dec 2019 18:43:55 GMT", "version": "v1" } ]
2020-03-18
[ [ "Herms", "Johannes", "" ], [ "Ibarra", "Alejandro", "" ] ]
We consider a scenario where the dark sector includes two Feebly Interacting Massive Particles (FIMPs), with couplings to the Standard Model particles that allow their production in the Early Universe via thermal freeze-in. These couplings generically lead to the decay of the heavier dark matter component into the lighter, possibly leading to observable signals of the otherwise elusive FIMPs. Concretely, we argue that the loop induced decay $\psi_2\rightarrow\psi_1\gamma$ for fermionic FIMPs, or $\phi_2\rightarrow\phi_1\gamma\gamma$ for scalar FIMPs, could have detectable rates for model parameters compatible with the observed dark matter abundance.
hep-ph/9306323
Johan Bijnens
Johan Bijnens, Eduardo de Rafael and Hanqing Zheng
Low--Energy Behavior of Two--Point Functions of Quark Currents
37 pages + 6 uuencoded figures, CERN TH 6924/93, CPT-93/P.2917, NORDITA 93/43-N,P
Z.Phys.C62:437-454,1994
10.1007/BF01555904
null
hep-ph nucl-th
null
We discuss vector, axial-vector, scalar and pseudoscalar two-point functions at low and intermediate energies. We first review what is known from chiral perturbation theory, as well as from a heat kernel expansion within the context of the extended Nambu-Jona-Lasinio (ENJL) model of ref. \cite{12}. In this work we derive then these two-point functions to all orders in the momenta and to leading order in $1/N_c$. We find an improved high-energy behaviour and a general way of parametrizing them that shows relations between some of the two-point functions, which are also valid in the presence of gluonic interactions. The similarity between the shape of the experimentally known spectral functions and the ones we derive, is greatly improved with respect to those predicted by the usual constituent quark like models. We also obtain the scalar mass $M_S = 2 M_Q$ independent of the regularization scheme. In the end, we calculate fully an example of a nonleptonic matrix element in the ENJL--model, the $\pi^+-\pi^0$ electromagnetic mass difference and find good agreement with the measured value.
[ { "created": "Mon, 28 Jun 1993 15:01:11 GMT", "version": "v1" } ]
2011-03-31
[ [ "Bijnens", "Johan", "" ], [ "de Rafael", "Eduardo", "" ], [ "Zheng", "Hanqing", "" ] ]
We discuss vector, axial-vector, scalar and pseudoscalar two-point functions at low and intermediate energies. We first review what is known from chiral perturbation theory, as well as from a heat kernel expansion within the context of the extended Nambu-Jona-Lasinio (ENJL) model of ref. \cite{12}. In this work we derive then these two-point functions to all orders in the momenta and to leading order in $1/N_c$. We find an improved high-energy behaviour and a general way of parametrizing them that shows relations between some of the two-point functions, which are also valid in the presence of gluonic interactions. The similarity between the shape of the experimentally known spectral functions and the ones we derive, is greatly improved with respect to those predicted by the usual constituent quark like models. We also obtain the scalar mass $M_S = 2 M_Q$ independent of the regularization scheme. In the end, we calculate fully an example of a nonleptonic matrix element in the ENJL--model, the $\pi^+-\pi^0$ electromagnetic mass difference and find good agreement with the measured value.
1712.07624
Maral Salajegheh
Maral Salajegheh, Hamzeh Khanpour, S. Mohammad Moosavi Nejad
Improved determination of $\bar d(x) - \bar u(x)$ flavor asymmetry in the proton by BONuS experiment at JLAB and using an approach by Brodsky, Hoyer, Peterson, and Sakai
10 pages, 5 figures
Phys. Rev. C 96, 065205, 2017
10.1103/PhysRevC.96.065205
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The experimental data taken from both Drell-Yan and deep-inelastic scattering (DIS) experiments suggest a sign-change in $\bar d(x) - \bar u(x)$ flavor asymmetry in the proton at large values of momentum fraction $x$. In this work, we present a phenomenological study of $\bar d(x) - \bar u(x)$ flavor asymmetry. First, we extract the $\bar d(x)-\bar u(x)$ distribution using the more recent data from the BONuS experiment at Jefferson Lab on the ratio of neutron to proton structure functions, $F_2^n/F_2^p$, and show that it undergoes a sing-change and becomes negative at large values of momentum fraction $x$, as expected. The stability and reliability of our obtained results have been examined by including target mass corrections (TMCs) as well as higher twist (HT) terms which are particularly important at the large-$x$ region at low Q$^2$. Then, we calculate the $\bar d(x) - \bar u(x)$ distribution using the Brodsky, Hoyer, Peterson, and Sakai (BHPS) model and show that if one chooses a mass for the down quark smaller than the one for the up quark it leads to a better description for the Fermilab E866 data. In order to prove this claim, we determine the masses of down and up sea quarks by fitting to the available and up-to-date experimental data for the $\bar d(x)-\bar u(x)$ distribution. In this respect, unlike the previous performed theoretical studies, we have shown that this distribution has a sign-change at $x>0.3$ after evolution to the scale of available experimental data.
[ { "created": "Wed, 20 Dec 2017 18:26:07 GMT", "version": "v1" } ]
2017-12-21
[ [ "Salajegheh", "Maral", "" ], [ "Khanpour", "Hamzeh", "" ], [ "Nejad", "S. Mohammad Moosavi", "" ] ]
The experimental data taken from both Drell-Yan and deep-inelastic scattering (DIS) experiments suggest a sign-change in $\bar d(x) - \bar u(x)$ flavor asymmetry in the proton at large values of momentum fraction $x$. In this work, we present a phenomenological study of $\bar d(x) - \bar u(x)$ flavor asymmetry. First, we extract the $\bar d(x)-\bar u(x)$ distribution using the more recent data from the BONuS experiment at Jefferson Lab on the ratio of neutron to proton structure functions, $F_2^n/F_2^p$, and show that it undergoes a sing-change and becomes negative at large values of momentum fraction $x$, as expected. The stability and reliability of our obtained results have been examined by including target mass corrections (TMCs) as well as higher twist (HT) terms which are particularly important at the large-$x$ region at low Q$^2$. Then, we calculate the $\bar d(x) - \bar u(x)$ distribution using the Brodsky, Hoyer, Peterson, and Sakai (BHPS) model and show that if one chooses a mass for the down quark smaller than the one for the up quark it leads to a better description for the Fermilab E866 data. In order to prove this claim, we determine the masses of down and up sea quarks by fitting to the available and up-to-date experimental data for the $\bar d(x)-\bar u(x)$ distribution. In this respect, unlike the previous performed theoretical studies, we have shown that this distribution has a sign-change at $x>0.3$ after evolution to the scale of available experimental data.
2112.14083
Fu-Hu Liu
Qiang Zhang, Ya-Qin Gao, Fu-Hu Liu, Khusniddin K. Olimov
An energy independent scaling of transverse momentum spectra of direct (prompt) photons from two-body processes in high-energy proton-proton collisions
25 pages, 10 figures, Annalen der Physik, accepted
Annalen der Physik 534, 2100567 (2022) (18 pages)
10.1002/andp.202100567
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Transverse momentum spectra of direct (prompt) photons from two-body processes in high-energy proton-proton (p+p) collisions are analyzed in this paper. We collected the experimental invariant cross-sections at mid-rapidity in p+p collisions measured by the UA6, CCOR, R806, R110, PHENIX, NA24, CMS, ALICE, and ATLAS Collaborations over a center-of-mass energy range from 24.3 GeV to 13 TeV. In fitting the data, we used different kinds of functions which include the revised Tsallis--Pareto-type function (the TP-like function) at the particle level, the convolution of two TP-like functions at the quark level, and the root-sum-of-squares of two revised Tsallis-like functions in which the quark chemical potentials $\mu _i=\mu_B/3$ or $\mu_i=0$, where $\mu_B$ is the baryon chemical potential. We have extracted the values of three main free parameters: the effective temperature $T$, power index $n_0$ (or entropy index $q$), and correction index $a_0$. After analyzing the changing trends of the parameters, we found that $T$, $q$, and $a_0$ increase and $n_0$ decreases with the increase of collision energy. Based on the analyses of transverse momentum spectra, an energy independent scaling, i.e. the $x_T$ scaling, is obtained.
[ { "created": "Tue, 28 Dec 2021 10:41:11 GMT", "version": "v1" }, { "created": "Sun, 16 Jan 2022 14:29:19 GMT", "version": "v2" } ]
2022-03-22
[ [ "Zhang", "Qiang", "" ], [ "Gao", "Ya-Qin", "" ], [ "Liu", "Fu-Hu", "" ], [ "Olimov", "Khusniddin K.", "" ] ]
Transverse momentum spectra of direct (prompt) photons from two-body processes in high-energy proton-proton (p+p) collisions are analyzed in this paper. We collected the experimental invariant cross-sections at mid-rapidity in p+p collisions measured by the UA6, CCOR, R806, R110, PHENIX, NA24, CMS, ALICE, and ATLAS Collaborations over a center-of-mass energy range from 24.3 GeV to 13 TeV. In fitting the data, we used different kinds of functions which include the revised Tsallis--Pareto-type function (the TP-like function) at the particle level, the convolution of two TP-like functions at the quark level, and the root-sum-of-squares of two revised Tsallis-like functions in which the quark chemical potentials $\mu _i=\mu_B/3$ or $\mu_i=0$, where $\mu_B$ is the baryon chemical potential. We have extracted the values of three main free parameters: the effective temperature $T$, power index $n_0$ (or entropy index $q$), and correction index $a_0$. After analyzing the changing trends of the parameters, we found that $T$, $q$, and $a_0$ increase and $n_0$ decreases with the increase of collision energy. Based on the analyses of transverse momentum spectra, an energy independent scaling, i.e. the $x_T$ scaling, is obtained.
1011.1411
Carlos E. Yaguna
Laura Lopez-Honorez, Carlos E. Yaguna
A new viable region of the inert doublet model
27 pages, 16 figures
JCAP 1101:002,2011
10.1088/1475-7516/2011/01/002
ULB-TH-10-37
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The inert doublet model, a minimal extension of the Standard Model by a second Higgs doublet, is one of the simplest and most attractive scenarios that can explain the dark matter. In this paper, we demonstrate the existence of a new viable region of the inert doublet model featuring dark matter masses between Mw and about 160 GeV. Along this previously overlooked region of the parameter space, the correct relic density is obtained thanks to cancellations between different diagrams contributing to dark matter annihilation into gauge bosons (W+W- and ZZ). First, we explain how these cancellations come about and show several examples illustrating the effect of the parameters of the model on the cancellations themselves and on the predicted relic density. Then, we perform a full scan of the new viable region and analyze it in detail by projecting it onto several two-dimensional planes. Finally, the prospects for the direct and the indirect detection of inert Higgs dark matter within this new viable region are studied. We find that present direct detection bounds already rule out a fraction of the new parameter space and that future direct detection experiments, such as Xenon100, will easily probe the remaining part in its entirety.
[ { "created": "Fri, 5 Nov 2010 14:49:32 GMT", "version": "v1" } ]
2011-04-20
[ [ "Lopez-Honorez", "Laura", "" ], [ "Yaguna", "Carlos E.", "" ] ]
The inert doublet model, a minimal extension of the Standard Model by a second Higgs doublet, is one of the simplest and most attractive scenarios that can explain the dark matter. In this paper, we demonstrate the existence of a new viable region of the inert doublet model featuring dark matter masses between Mw and about 160 GeV. Along this previously overlooked region of the parameter space, the correct relic density is obtained thanks to cancellations between different diagrams contributing to dark matter annihilation into gauge bosons (W+W- and ZZ). First, we explain how these cancellations come about and show several examples illustrating the effect of the parameters of the model on the cancellations themselves and on the predicted relic density. Then, we perform a full scan of the new viable region and analyze it in detail by projecting it onto several two-dimensional planes. Finally, the prospects for the direct and the indirect detection of inert Higgs dark matter within this new viable region are studied. We find that present direct detection bounds already rule out a fraction of the new parameter space and that future direct detection experiments, such as Xenon100, will easily probe the remaining part in its entirety.
hep-ph/0407294
Christian Fischer
C. S. Fischer, F. Llanes-Estrada, R. Alkofer
Dynamical Mass Generation in Landau gauge QCD
6 pages, 6 figures, Summary of a talk given at the international conference QCD DOWN UNDER, March 10 - 19, Adelaide, Australia
Nucl.Phys.Proc.Suppl.141:128-133,2005
10.1016/j.nuclphysbps.2004.12.020
UNITU-THEP-7/04, IPPP/04/34, DCPT/04/68
hep-ph
null
We summarise results on the infrared behaviour of Landau gauge QCD from the Green's functions approach and lattice calculations. Approximate, nonperturbative solutions for the ghost, gluon and quark propagators as well as first results for the quark-gluon vertex from a coupled set of Dyson-Schwinger equations are compared to quenched and unquenched lattice results. Almost quantitative agreement is found for all three propagators. Similar effects of unquenching are found in both approaches. The dynamically generated quark masses are close to `phenomenological' values. First results for the quark-gluon vertex indicate a complex tensor structure of the non-perturbative quark-gluon interaction.
[ { "created": "Mon, 26 Jul 2004 13:20:12 GMT", "version": "v1" } ]
2008-11-26
[ [ "Fischer", "C. S.", "" ], [ "Llanes-Estrada", "F.", "" ], [ "Alkofer", "R.", "" ] ]
We summarise results on the infrared behaviour of Landau gauge QCD from the Green's functions approach and lattice calculations. Approximate, nonperturbative solutions for the ghost, gluon and quark propagators as well as first results for the quark-gluon vertex from a coupled set of Dyson-Schwinger equations are compared to quenched and unquenched lattice results. Almost quantitative agreement is found for all three propagators. Similar effects of unquenching are found in both approaches. The dynamically generated quark masses are close to `phenomenological' values. First results for the quark-gluon vertex indicate a complex tensor structure of the non-perturbative quark-gluon interaction.
hep-ph/9609288
Hans Eggers
H.C. Eggers, B. Buschbeck, P. Lipa
Pion interferometry with higher-order cumulants
Latex, 11 pages, 3 figs included via epsf. Stara Lesna. PRELIMINARY data
null
null
HEPHY-PUB 634/95
hep-ph hep-ex
null
We have measured second- and third-order cumulants in UA1 data ($\bar pp$ collisions at 630 GeV/c). Rather than quoting numerical values for source parameters, we have used these in three checks to test the ``quantum statistics'' theory for consistency over these cumulants. In the process, we have found a method for folding theoretical correlation functions with experimental one-particle distributions. Our preliminary results appear to indicate that, for the specific tests performed, the data contradicts the theory.
[ { "created": "Sun, 8 Sep 1996 13:32:06 GMT", "version": "v1" } ]
2007-05-23
[ [ "Eggers", "H. C.", "" ], [ "Buschbeck", "B.", "" ], [ "Lipa", "P.", "" ] ]
We have measured second- and third-order cumulants in UA1 data ($\bar pp$ collisions at 630 GeV/c). Rather than quoting numerical values for source parameters, we have used these in three checks to test the ``quantum statistics'' theory for consistency over these cumulants. In the process, we have found a method for folding theoretical correlation functions with experimental one-particle distributions. Our preliminary results appear to indicate that, for the specific tests performed, the data contradicts the theory.
0906.5593
Magno Machado
M.A. Betemps, M.V.T. Machado
A simple model for the nuclear unintegrated gluon distribution
5 pages, one figure.Version to be published in European Physical Journal C
Eur.Phys.J.C65:427-431,2010
10.1140/epjc/s10052-009-1212-y
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The solution of non-linear evolution equations for dense nuclear gluon density has been suggested as one of the relevant mechanisms of pA and AA collisions at collider energies. Here we study a simple parameterization for the unintegrated gluon distribution using the knowledge of asymptotic solutions of the Balitsky-Kovchegov equation, describing high-energy QCD in the presence of saturation effects. A satisfactory description of nuclear shadowing at small-x is obtained and it allows us to understand the qualitative behavior shown by data.
[ { "created": "Tue, 30 Jun 2009 17:52:32 GMT", "version": "v1" }, { "created": "Wed, 11 Nov 2009 13:18:15 GMT", "version": "v2" } ]
2010-02-11
[ [ "Betemps", "M. A.", "" ], [ "Machado", "M. V. T.", "" ] ]
The solution of non-linear evolution equations for dense nuclear gluon density has been suggested as one of the relevant mechanisms of pA and AA collisions at collider energies. Here we study a simple parameterization for the unintegrated gluon distribution using the knowledge of asymptotic solutions of the Balitsky-Kovchegov equation, describing high-energy QCD in the presence of saturation effects. A satisfactory description of nuclear shadowing at small-x is obtained and it allows us to understand the qualitative behavior shown by data.
hep-ph/9610458
null
J. A. Grifols, R. N. Mohapatra, A. Riotto
Astrophysical bounds on superlight gravitinos
8 pages, no figures
Phys.Lett. B401 (1997) 283-286
10.1016/S0370-2693(97)00394-8
UAB-FT-400, UMD-PP-97-44, Fermilab-Pub-96/373-A
hep-ph
null
We derive the allowed mass range for the superlight gravitino present in a large class of supersymmetric models from the observed luminosity from Supernova 1987A. We find that for photino masses of order 100 GeV, the mass range $2.6\times 10^{-6} eV \leq m_{\tilde{g}} \leq 2.2\times 10^{-8} eV$ for the gravitino $\tilde{g}$ is excluded by SN1987A observations. Unlike the bounds on $m_{\tilde{g}}$ from nucleosynthesis, the bounds in the present paper do not depend critically on the uncertainties of the observational input.
[ { "created": "Wed, 23 Oct 1996 16:25:14 GMT", "version": "v1" } ]
2009-10-30
[ [ "Grifols", "J. A.", "" ], [ "Mohapatra", "R. N.", "" ], [ "Riotto", "A.", "" ] ]
We derive the allowed mass range for the superlight gravitino present in a large class of supersymmetric models from the observed luminosity from Supernova 1987A. We find that for photino masses of order 100 GeV, the mass range $2.6\times 10^{-6} eV \leq m_{\tilde{g}} \leq 2.2\times 10^{-8} eV$ for the gravitino $\tilde{g}$ is excluded by SN1987A observations. Unlike the bounds on $m_{\tilde{g}}$ from nucleosynthesis, the bounds in the present paper do not depend critically on the uncertainties of the observational input.
2211.10359
Joao G. Rosa
Jo\~ao G. Rosa and Duarte M. C. Silva
Comparable dark matter and baryon abundances with a heavy dark sector
5 pages, 2 figures
null
null
null
hep-ph astro-ph.CO gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a scenario that explains the comparable abundances of dark matter (DM) and baryons without any coincidence in the corresponding particle masses. Here, DM corresponds to heavy "dark baryons" in a hidden MSSM-like dark sector, where the supersymmetry breaking scale can be several orders of magnitude larger than in the visible sector. In both sectors a baryon asymmetry is generated via the Affleck-Dine mechanism, and the smaller dark baryon-to-entropy ratio partially compensates the larger dark baryon masses to give similar densities in the two sectors. The large mass hierarchy also naturally results in an asymmetric reheating of these sequestered sectors. Moreover, this scenario predicts uncorrelated DM and baryon isocurvature perturbations.
[ { "created": "Fri, 18 Nov 2022 16:58:53 GMT", "version": "v1" } ]
2022-11-21
[ [ "Rosa", "João G.", "" ], [ "Silva", "Duarte M. C.", "" ] ]
We propose a scenario that explains the comparable abundances of dark matter (DM) and baryons without any coincidence in the corresponding particle masses. Here, DM corresponds to heavy "dark baryons" in a hidden MSSM-like dark sector, where the supersymmetry breaking scale can be several orders of magnitude larger than in the visible sector. In both sectors a baryon asymmetry is generated via the Affleck-Dine mechanism, and the smaller dark baryon-to-entropy ratio partially compensates the larger dark baryon masses to give similar densities in the two sectors. The large mass hierarchy also naturally results in an asymmetric reheating of these sequestered sectors. Moreover, this scenario predicts uncorrelated DM and baryon isocurvature perturbations.
hep-ph/0304049
D. J. Miller
D.J. Miller, R. Nevzorov, P.M. Zerwas
The Higgs Sector of the Next-to-Minimal Supersymmetric Standard Model
32 pages with 12 figures; references and parameters updated; a few minor comments added
Nucl.Phys.B681:3-30,2004
10.1016/j.nuclphysb.2003.12.021
CERN-TH/2003-077, DESY 03-066, ITEP-03-05
hep-ph
null
The Higgs boson spectrum of the Next-to-Minimal Supersymmetric Standard Model is examined. The model includes a singlet Higgs field S in addition to the two Higgs doublets of the minimal extension. `Natural' values of the parameters of the model are motivated by their renormalization group running and the vacuum stability. The qualitative features of the Higgs boson masses are dependent on how strongly the Peccei-Quinn U(1) symmetry of the model is broken, measured by the self-coupling of the singlet field in the superpotential. We explore the Higgs boson masses and their couplings to gauge bosons for various representative scenarios.
[ { "created": "Fri, 4 Apr 2003 14:06:27 GMT", "version": "v1" }, { "created": "Wed, 4 Jun 2003 09:35:30 GMT", "version": "v2" } ]
2010-04-06
[ [ "Miller", "D. J.", "" ], [ "Nevzorov", "R.", "" ], [ "Zerwas", "P. M.", "" ] ]
The Higgs boson spectrum of the Next-to-Minimal Supersymmetric Standard Model is examined. The model includes a singlet Higgs field S in addition to the two Higgs doublets of the minimal extension. `Natural' values of the parameters of the model are motivated by their renormalization group running and the vacuum stability. The qualitative features of the Higgs boson masses are dependent on how strongly the Peccei-Quinn U(1) symmetry of the model is broken, measured by the self-coupling of the singlet field in the superpotential. We explore the Higgs boson masses and their couplings to gauge bosons for various representative scenarios.
1203.3276
Teruki Kamon
Rouzbeh Allahverdi (1), Bhaskar Dutta (2), Teruki Kamon (2,3), Abram Krislock (2,4) ((1) University of New Mexico, (2) Texas A and M University, (3) Kyungpook National University, (4) Stockholm University)
Lepton Flavor Violation at the Large Hadron Collider
8 pages, 6 figures, accepted for publiucation in PRD
null
10.1103/PhysRevD.86.015026
MIFPA-12-06
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate a potential of discovering lepton flavor violation (LFV) at the Large Hadron Collider. A sizeable LFV in low energy supersymmetry can be induced by massive right-handed neutrinos, which can explain neutrino oscillations via the seesaw mechanism. We investigate a scenario where the distribution of an invariant mass of two hadronically decaying taus ($\tauh\tauh$) from $\schizero{2}$ decays is the same in events with or without LFV. We first develop a transfer function using this ditau mass distribution to model the shape of the non-LFV $\tauh\mu$ invariant mass. We then show the feasibility of extracting the LFV $\tauh\mu$ signal. The proposed technique can also be applied for a LFV $\tauh e$ search.
[ { "created": "Thu, 15 Mar 2012 06:41:06 GMT", "version": "v1" }, { "created": "Sun, 22 Jul 2012 02:42:27 GMT", "version": "v2" } ]
2013-05-30
[ [ "Allahverdi", "Rouzbeh", "" ], [ "Dutta", "Bhaskar", "" ], [ "Kamon", "Teruki", "" ], [ "Krislock", "Abram", "" ] ]
We investigate a potential of discovering lepton flavor violation (LFV) at the Large Hadron Collider. A sizeable LFV in low energy supersymmetry can be induced by massive right-handed neutrinos, which can explain neutrino oscillations via the seesaw mechanism. We investigate a scenario where the distribution of an invariant mass of two hadronically decaying taus ($\tauh\tauh$) from $\schizero{2}$ decays is the same in events with or without LFV. We first develop a transfer function using this ditau mass distribution to model the shape of the non-LFV $\tauh\mu$ invariant mass. We then show the feasibility of extracting the LFV $\tauh\mu$ signal. The proposed technique can also be applied for a LFV $\tauh e$ search.
1103.0643
Joannis Papavassiliou
Joannis Papavassiliou
A gauge-technique Ansatz for the three gluon vertex of the background field method
10 pages, 2 figures. Contribution for the workshop "The many faces of QCD", 1-5 Nov 2010, Ghent, Belgium
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The vertex connecting one background gluon with two quantum ones constitutes a central ingredient in the gauge-invariant Schwinger-Dyson equation that determines the non-perturbative dynamics of the gluon propagator. This vertex satisfies a Ward identity with respect to the background gluon, and a Slavnov-Taylor identity with respect to the two quantum gluons. We present a complete Ansatz for this vertex, which satisfies both aforementioned identities. This entire construction depends crucially on a set of constraints relating the various form-factors of the ghost Green's functions appearing in the Slavnov-Taylor identity satisfied by the vertex. The validity of these constraints is demonstrated to all orders.
[ { "created": "Thu, 3 Mar 2011 10:11:41 GMT", "version": "v1" } ]
2011-03-04
[ [ "Papavassiliou", "Joannis", "" ] ]
The vertex connecting one background gluon with two quantum ones constitutes a central ingredient in the gauge-invariant Schwinger-Dyson equation that determines the non-perturbative dynamics of the gluon propagator. This vertex satisfies a Ward identity with respect to the background gluon, and a Slavnov-Taylor identity with respect to the two quantum gluons. We present a complete Ansatz for this vertex, which satisfies both aforementioned identities. This entire construction depends crucially on a set of constraints relating the various form-factors of the ghost Green's functions appearing in the Slavnov-Taylor identity satisfied by the vertex. The validity of these constraints is demonstrated to all orders.
2406.00679
Yong-Rui Chen
Yong-rui Chen, Yang-yang Tan, Wei-jie Fu
Critical dynamics of Model H within the real-time fRG approach
10 pages, 6 figures,
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The critical dynamics of Model H with a conserved order parameter coupled to a transverse momentum density which describes the gas-liquid or binary-fluid transitions is investigated within the functional renormalization group approach formulated on the closed time path. According to the dynamic scaling analysis, Model H and QCD critical end point belong to the same dynamic universality class in the critical region. The higher-order correction of the transport coefficient $\bar\lambda$ and shear viscosity $\bar\eta$ arising from mode-couplings are obtained by calculating the two-point correlation functions. The flow equation of a dimensionless coupling constant for nondissipative interactions is derived to look for the fixed-point solution of the system. The scaling relation between the critical exponent of the transport coefficient and that of the shear viscosity is estimated. Finally, the dynamic critical exponent $z$ is obtained as a function of the spatial dimension $d$.
[ { "created": "Sun, 2 Jun 2024 09:19:44 GMT", "version": "v1" } ]
2024-06-04
[ [ "Chen", "Yong-rui", "" ], [ "Tan", "Yang-yang", "" ], [ "Fu", "Wei-jie", "" ] ]
The critical dynamics of Model H with a conserved order parameter coupled to a transverse momentum density which describes the gas-liquid or binary-fluid transitions is investigated within the functional renormalization group approach formulated on the closed time path. According to the dynamic scaling analysis, Model H and QCD critical end point belong to the same dynamic universality class in the critical region. The higher-order correction of the transport coefficient $\bar\lambda$ and shear viscosity $\bar\eta$ arising from mode-couplings are obtained by calculating the two-point correlation functions. The flow equation of a dimensionless coupling constant for nondissipative interactions is derived to look for the fixed-point solution of the system. The scaling relation between the critical exponent of the transport coefficient and that of the shear viscosity is estimated. Finally, the dynamic critical exponent $z$ is obtained as a function of the spatial dimension $d$.
1108.2733
Gui-Jun Ding
Gui-Jun Ding, Davide Meloni
A Model for Tri-bimaximal Mixing from a Completely Broken $A_4$
28 pages, 3 figures
null
10.1016/j.nuclphysb.2011.10.001
RM3-TH/11-10
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a new $A_4$ model in which both the right-handed neutrinos and right-handed charged leptons transform as $A_4$ singlets. We reproduce tri-bimaximal mixing pattern exactly although the $A_4$ symmetry is broken completely at leading order in both the neutrino and charged lepton sectors. The charged lepton mass hierarchies are controlled by the spontaneous breaking of the flavor symmetry. The light neutrino spectrum is predicted to be of normal type and the lightest neutrino is massless at leading order. Although the reactor angle $\theta_{13}$ is expected to be of order $\lambda^2_c$ from the next to leading order corrections, this model cannot be ruled out by current experimental data including the latest T2K results. Leptogenesis is realized via the resonant leptogenesis of the second and the third heavy right-handed neutrinos which are degenerate at leading order. The phenomenological consequences for lepton flavor violation are discussed in detail.
[ { "created": "Fri, 12 Aug 2011 22:46:32 GMT", "version": "v1" }, { "created": "Sat, 8 Oct 2011 11:02:10 GMT", "version": "v2" } ]
2011-10-11
[ [ "Ding", "Gui-Jun", "" ], [ "Meloni", "Davide", "" ] ]
We propose a new $A_4$ model in which both the right-handed neutrinos and right-handed charged leptons transform as $A_4$ singlets. We reproduce tri-bimaximal mixing pattern exactly although the $A_4$ symmetry is broken completely at leading order in both the neutrino and charged lepton sectors. The charged lepton mass hierarchies are controlled by the spontaneous breaking of the flavor symmetry. The light neutrino spectrum is predicted to be of normal type and the lightest neutrino is massless at leading order. Although the reactor angle $\theta_{13}$ is expected to be of order $\lambda^2_c$ from the next to leading order corrections, this model cannot be ruled out by current experimental data including the latest T2K results. Leptogenesis is realized via the resonant leptogenesis of the second and the third heavy right-handed neutrinos which are degenerate at leading order. The phenomenological consequences for lepton flavor violation are discussed in detail.
1205.0988
Christian Schwinn
M. Beneke, P. Falgari, S. Klein, J. Piclum, C. Schwinn
NNLL threshold resummation for the total top-pair production cross section
5 pages, 2 figures, moriond.sty included. Contribution to the proceedings of the 47th Rencontres de Moriond on QCD and High Energy Interactions, March 10-17, 2012, La Thuile, Italy. v2: references updated
null
null
FR-PHENO-2012-009; ITP-UU-12/17; SFB/CPP-12-22; SPIN-12/15; TTK-12-18; TUM-HEP-838/12
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present predictions for the total top-quark pair production cross section at the Tevatron and the LHC with 7,8 and 14 TeV centre-of-mass energy, including the resummation of threshold logarithms and Coulomb corrections through next-to-next-to-leading logarithmic order, and top-antitop bound-state contributions. The remaining theoretical and PDF uncertainties and prospects for the measurement of the top mass from the total cross section are discussed.
[ { "created": "Fri, 4 May 2012 15:44:17 GMT", "version": "v1" }, { "created": "Wed, 4 Jul 2012 14:50:34 GMT", "version": "v2" } ]
2012-07-05
[ [ "Beneke", "M.", "" ], [ "Falgari", "P.", "" ], [ "Klein", "S.", "" ], [ "Piclum", "J.", "" ], [ "Schwinn", "C.", "" ] ]
We present predictions for the total top-quark pair production cross section at the Tevatron and the LHC with 7,8 and 14 TeV centre-of-mass energy, including the resummation of threshold logarithms and Coulomb corrections through next-to-next-to-leading logarithmic order, and top-antitop bound-state contributions. The remaining theoretical and PDF uncertainties and prospects for the measurement of the top mass from the total cross section are discussed.
0805.2944
John Mason
Linda M. Carpenter, Michael Dine, Guido Festuccia, and John D. Mason
Implementing General Gauge Mediation
21 pages, 2 Figures Minor Corrections
Phys.Rev.D79:035002,2009
10.1103/PhysRevD.79.035002
SCIPP-08/04
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently there has been much progress in building models of gauge mediation, often with predictions different than those of minimal gauge mediation. Meade, Seiberg, and Shih have characterized the most general spectrum which can arise in gauge mediated models. We discuss some of the challenges of building models of General Gauge Mediation, especially the problem of messenger parity and issues connected with R symmetry breaking and CP violation. We build a variety of viable, weakly coupled models which exhibit some or all of the possible low energy parameters.
[ { "created": "Mon, 19 May 2008 20:03:05 GMT", "version": "v1" }, { "created": "Wed, 21 May 2008 23:47:28 GMT", "version": "v2" } ]
2009-02-20
[ [ "Carpenter", "Linda M.", "" ], [ "Dine", "Michael", "" ], [ "Festuccia", "Guido", "" ], [ "Mason", "John D.", "" ] ]
Recently there has been much progress in building models of gauge mediation, often with predictions different than those of minimal gauge mediation. Meade, Seiberg, and Shih have characterized the most general spectrum which can arise in gauge mediated models. We discuss some of the challenges of building models of General Gauge Mediation, especially the problem of messenger parity and issues connected with R symmetry breaking and CP violation. We build a variety of viable, weakly coupled models which exhibit some or all of the possible low energy parameters.
1902.04916
Zuowei Liu
Xuewen Liu, Zuowei Liu and Yushan Su
Two-mediator dark matter models and cosmic electron excess
23 pages, 21 figures
null
10.1007/JHEP06(2019)109
null
hep-ph astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The cosmic electron energy spectrum recently observed by the DAMPE experiment exhibits two interesting features, including a break around 0.9 TeV and a sharp resonance near 1.4 TeV. In this analysis, we propose a dark matter explanation to both exotic features seen by DAMPE. In our model, dark matter annihilates in the galaxy via two different channels that lead to both a narrow resonance spectrum near 1.4 TeV and electron excess events over an extended energy range thus generating the break structure around TeV. The two annihilation channels are mediated by two gauge bosons that interact both with dark matter and with the standard model fermions. Dark matter annihilations through the s-channel process mediated by the heavier boson produce monoenergetic electron-positron pairs leading to the resonance excess. The lighter boson has a mass smaller than the dark matter such that they can be on-shell produced in dark matter annihilations in the galaxy; the lighter bosons in the final state subsequently decay to generate the extended excess events due to the smeared electron energy spectrum in this process. We further analyze constraints from various experiments, including HESS, Fermi, AMS, and LHC, to the parameter space of the model where both excess events can be accounted for. In order to interpret the two new features in the DAMPE data, dark matter annihilation cross sections in the current galaxy are typically much larger than the canonical thermal cross section needed for the correct dark matter relic abundance. This discrepancy, however, is remedied by the nonperturbative Sommerfeld enhancement because of the existence of a lighter mediator in the model.
[ { "created": "Wed, 13 Feb 2019 14:28:25 GMT", "version": "v1" } ]
2022-10-12
[ [ "Liu", "Xuewen", "" ], [ "Liu", "Zuowei", "" ], [ "Su", "Yushan", "" ] ]
The cosmic electron energy spectrum recently observed by the DAMPE experiment exhibits two interesting features, including a break around 0.9 TeV and a sharp resonance near 1.4 TeV. In this analysis, we propose a dark matter explanation to both exotic features seen by DAMPE. In our model, dark matter annihilates in the galaxy via two different channels that lead to both a narrow resonance spectrum near 1.4 TeV and electron excess events over an extended energy range thus generating the break structure around TeV. The two annihilation channels are mediated by two gauge bosons that interact both with dark matter and with the standard model fermions. Dark matter annihilations through the s-channel process mediated by the heavier boson produce monoenergetic electron-positron pairs leading to the resonance excess. The lighter boson has a mass smaller than the dark matter such that they can be on-shell produced in dark matter annihilations in the galaxy; the lighter bosons in the final state subsequently decay to generate the extended excess events due to the smeared electron energy spectrum in this process. We further analyze constraints from various experiments, including HESS, Fermi, AMS, and LHC, to the parameter space of the model where both excess events can be accounted for. In order to interpret the two new features in the DAMPE data, dark matter annihilation cross sections in the current galaxy are typically much larger than the canonical thermal cross section needed for the correct dark matter relic abundance. This discrepancy, however, is remedied by the nonperturbative Sommerfeld enhancement because of the existence of a lighter mediator in the model.
1708.06615
Jie Ren
Jie Ren, Lei Wu, Jin Min Yang, Jun Zhao
Exploring supersymmetry with machine learning
7 pages, 8 figures. Discussions, comments and CMSSM model are added. Accepted for publication in Nuclear Physics B
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Investigation of well-motivated parameter space in the theories of Beyond the Standard Model (BSM) plays an important role in new physics discoveries. However, a large-scale exploration of models with multi-parameter or equivalent solutions with a finite separation, such as supersymmetric models, is typically a time-consuming and challenging task. In this paper, we propose a self-exploration method, named Machine Learning Scan (MLS), to achieve an efficient test of models. As a proof-of-concept, we apply MLS to investigate the subspace of MSSM and CMSSM and find that such a method can reduce the computational cost and may be helpful for accelerating the exploration of supersymmetry.
[ { "created": "Tue, 22 Aug 2017 13:56:48 GMT", "version": "v1" }, { "created": "Wed, 6 Sep 2017 16:47:12 GMT", "version": "v2" }, { "created": "Mon, 8 Apr 2019 14:45:27 GMT", "version": "v3" } ]
2019-04-09
[ [ "Ren", "Jie", "" ], [ "Wu", "Lei", "" ], [ "Yang", "Jin Min", "" ], [ "Zhao", "Jun", "" ] ]
Investigation of well-motivated parameter space in the theories of Beyond the Standard Model (BSM) plays an important role in new physics discoveries. However, a large-scale exploration of models with multi-parameter or equivalent solutions with a finite separation, such as supersymmetric models, is typically a time-consuming and challenging task. In this paper, we propose a self-exploration method, named Machine Learning Scan (MLS), to achieve an efficient test of models. As a proof-of-concept, we apply MLS to investigate the subspace of MSSM and CMSSM and find that such a method can reduce the computational cost and may be helpful for accelerating the exploration of supersymmetry.
2203.13286
Fr\'ed\'eric Dux
Fr\'ed\'eric Dux, Adrien Florio, Juraj Klari\'c, Andrey Shkerin, Inar Timiryasov
Preheating in Palatini Higgs inflation on the lattice
20 pages, 9 figures. V2: corrected an error in the Einstein frame potential of the gauge bosons (eq. 2.18), and added references. V3: appendix added, matches the published version
JCAP 09 (2022), 015
10.1088/1475-7516/2022/09/015
FTPI-MINN-22-08, UMN-TH-4117/22, CP3-22-28
hep-ph gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
We study preheating following Higgs inflation in the Palatini formulation of gravity. We numerically evolve perturbations of the radial mode of the Higgs field and that of three scalars modeling the gauge bosons. We compare the two non-perturbative mechanisms of growth of excitations -- parametric resonance and tachyonic instability -- and confirm that the latter plays the dominant role. Our results provide further evidence that preheating in Palatini Higgs inflation happens within a single oscillation of the Higgs field about the bottom of its potential, consistent with the approximation of an instantaneous preheating.
[ { "created": "Thu, 24 Mar 2022 18:25:02 GMT", "version": "v1" }, { "created": "Wed, 13 Apr 2022 15:13:31 GMT", "version": "v2" }, { "created": "Sat, 17 Sep 2022 06:58:23 GMT", "version": "v3" } ]
2022-09-20
[ [ "Dux", "Frédéric", "" ], [ "Florio", "Adrien", "" ], [ "Klarić", "Juraj", "" ], [ "Shkerin", "Andrey", "" ], [ "Timiryasov", "Inar", "" ] ]
We study preheating following Higgs inflation in the Palatini formulation of gravity. We numerically evolve perturbations of the radial mode of the Higgs field and that of three scalars modeling the gauge bosons. We compare the two non-perturbative mechanisms of growth of excitations -- parametric resonance and tachyonic instability -- and confirm that the latter plays the dominant role. Our results provide further evidence that preheating in Palatini Higgs inflation happens within a single oscillation of the Higgs field about the bottom of its potential, consistent with the approximation of an instantaneous preheating.
2405.08752
Waqas Riaz
Waqas Riaz
Effective Field Theory Framework: Construction Strategies and Soft Collinear Effective Theory (SCET)
null
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Effective Field Theory (EFT) stands as a cornerstone in modern theoretical physics, offering a powerful framework for describing the dynamics of physical systems across a wide range of energy scales. This article provides an in-depth exploration of EFT and its diverse applications in various branches of physics. Beginning with a foundational overview of EFT principles, including its formulation, renormalization, and power counting rules, we delve into its versatility in addressing complex phenomena beyond the reach of traditional approaches. In particle physics, EFT techniques are indispensable for precision calculations and theoretical predictions, enabling the systematic treatment of quantum field theories at energies inaccessible to direct experimentation. Moreover, EFT plays a crucial role in understanding the low-energy dynamics of hadrons, nuclei, and other strongly interacting systems. This article aims to provide a comprehensive introduction to EFT and as an example of constructing EFT from a fundamental theory like QCD we explore how to construct a soft collinear effective theory SCET.
[ { "created": "Tue, 14 May 2024 16:37:01 GMT", "version": "v1" } ]
2024-05-15
[ [ "Riaz", "Waqas", "" ] ]
Effective Field Theory (EFT) stands as a cornerstone in modern theoretical physics, offering a powerful framework for describing the dynamics of physical systems across a wide range of energy scales. This article provides an in-depth exploration of EFT and its diverse applications in various branches of physics. Beginning with a foundational overview of EFT principles, including its formulation, renormalization, and power counting rules, we delve into its versatility in addressing complex phenomena beyond the reach of traditional approaches. In particle physics, EFT techniques are indispensable for precision calculations and theoretical predictions, enabling the systematic treatment of quantum field theories at energies inaccessible to direct experimentation. Moreover, EFT plays a crucial role in understanding the low-energy dynamics of hadrons, nuclei, and other strongly interacting systems. This article aims to provide a comprehensive introduction to EFT and as an example of constructing EFT from a fundamental theory like QCD we explore how to construct a soft collinear effective theory SCET.
0711.0203
Alexey A. Petrov
Alexey A Petrov
Implications of final state interactions in B-decays
6 pages, no figures; invited talk at 2nd Meeting of the APS Topical Group on Hadronic Physics, Nashville, Tennesse, 22-24 Oct 2006
J.Phys.Conf.Ser.69:012010,2007
10.1088/1742-6596/69/1/012010
WSU-HEP-0603
hep-ph
null
I give a brief review of final state interactions (FSI) in heavy meson decays, paying particular attention to B-meson physics. Available theoretical methods for dealing with the effects of FSI are discussed.
[ { "created": "Thu, 1 Nov 2007 19:43:21 GMT", "version": "v1" } ]
2008-11-26
[ [ "Petrov", "Alexey A", "" ] ]
I give a brief review of final state interactions (FSI) in heavy meson decays, paying particular attention to B-meson physics. Available theoretical methods for dealing with the effects of FSI are discussed.
2402.05678
Kingman Cheung
Kingman Cheung and C.J. Ouseph
Interpretation of excess in $H \to Z \gamma$ using a light axion-like particle
8 pages, 2 figures
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We interpret the recent excess in a rare decay of the Higgs boson, $H\to Z\gamma$, using a light axion-like particle (ALP) in the mass range less than 0.2 GeV. The dominant decay of such a light ALP is into a pair of photons, which are very close to each other, such that it mimics a single photon in the ECAL detector. It can explain the excess with a coupling $C^{\rm eff}_{aZH} / \Lambda \sim 4 \times 10^{-5}\;{\rm GeV}^{-1}$. A potential test would be the rare decay of the $Z$ boson $Z \to a H^* \to a (b \bar b)$ at the Tera-$Z$ option of the future FCC and CEPC. However, it has a branching ratio of only $O(10^{-12})$, and thus barely testable. The production cross section for $pp \to Z^* \to a H$ via the same coupling $C^{\rm eff}_{aZH} / \Lambda$ at the LHC is too small for detection.
[ { "created": "Thu, 8 Feb 2024 13:55:11 GMT", "version": "v1" } ]
2024-02-09
[ [ "Cheung", "Kingman", "" ], [ "Ouseph", "C. J.", "" ] ]
We interpret the recent excess in a rare decay of the Higgs boson, $H\to Z\gamma$, using a light axion-like particle (ALP) in the mass range less than 0.2 GeV. The dominant decay of such a light ALP is into a pair of photons, which are very close to each other, such that it mimics a single photon in the ECAL detector. It can explain the excess with a coupling $C^{\rm eff}_{aZH} / \Lambda \sim 4 \times 10^{-5}\;{\rm GeV}^{-1}$. A potential test would be the rare decay of the $Z$ boson $Z \to a H^* \to a (b \bar b)$ at the Tera-$Z$ option of the future FCC and CEPC. However, it has a branching ratio of only $O(10^{-12})$, and thus barely testable. The production cross section for $pp \to Z^* \to a H$ via the same coupling $C^{\rm eff}_{aZH} / \Lambda$ at the LHC is too small for detection.
0707.2419
Deog Ki Hong
Deog Ki Hong (Pusan National Univ.)
Effective theory of color superconductivity
8 pages, 3 figures; To appear in the proceedings of YKIS Seminar on New Frontiers in QCD, Kyoto, Japan, 20 Nov - 8 Dec 2006
Prog.Theor.Phys.Suppl.168:397-404,2007
10.1143/PTPS.168.397
PNUTP-07-A04
hep-ph
null
We briefly review an effective theory of QCD at high baryon density, describing the relevant modes near the Fermi surface. The high density effective theory has properties of reparametrization invariance and gauge invariance, maintained in a subtle way. It also has a positive measure, allowing lattice simulations at high baryon density. We then apply it to gapless superconductors and discuss recent proposals to resolve the magnetic instability of gapless superconductivity.
[ { "created": "Tue, 17 Jul 2007 02:21:30 GMT", "version": "v1" } ]
2008-11-26
[ [ "Hong", "Deog Ki", "", "Pusan National Univ." ] ]
We briefly review an effective theory of QCD at high baryon density, describing the relevant modes near the Fermi surface. The high density effective theory has properties of reparametrization invariance and gauge invariance, maintained in a subtle way. It also has a positive measure, allowing lattice simulations at high baryon density. We then apply it to gapless superconductors and discuss recent proposals to resolve the magnetic instability of gapless superconductivity.
hep-ph/9411321
Dietrich Lehner
Dima Bardin, Dietrich Lehner and Tord Riemann
Complete Initial State Radiation to off-Shell $Z^0$~PAIR Production in $e^+e^-$~ANNIHILATION
To appear in the Proceedings of the IX International Workshop ``High Energy Physics and Quantum Field Theory", Zvenigorod, Moscow Region, Russia, September $15^{th}-22^{nd}~1994$. 7 pages (LaTeX) with 2 figures (not included). A uuencoded file containing the LaTeX source code, picture postscript files and a full postscript version is available via anonymous ftp at ftp://ftp.ifh.de/pub/preprint/desy94-216.uu
null
null
null
hep-ph
null
A cross-section calculation for the Standard Model reaction $e^+e^- \rightarrow (Z^0Z^0) \rightarrow f_1\bar{f_1}f_2\bar{f_2}$ including the effects of the finite $Z^0$~width and initial state radiative corrections is presented. The angular phase space integrations are performed analytically, leaving the invariant masses for numerical integration. Semi-analytical and numerical results in the energy range $\sqrt{s}=150\;GeV$ to $1\;TeV$ are reported.
[ { "created": "Thu, 17 Nov 1994 11:47:09 GMT", "version": "v1" } ]
2007-05-23
[ [ "Bardin", "Dima", "" ], [ "Lehner", "Dietrich", "" ], [ "Riemann", "Tord", "" ] ]
A cross-section calculation for the Standard Model reaction $e^+e^- \rightarrow (Z^0Z^0) \rightarrow f_1\bar{f_1}f_2\bar{f_2}$ including the effects of the finite $Z^0$~width and initial state radiative corrections is presented. The angular phase space integrations are performed analytically, leaving the invariant masses for numerical integration. Semi-analytical and numerical results in the energy range $\sqrt{s}=150\;GeV$ to $1\;TeV$ are reported.
hep-ph/9607367
Gg160
H. Walliser and G.Holzwarth (Siegen University)
Electro-excitation amplitudes of the Delta-isobar in the Skyrme model
15 pages, LaTeX, 4 PS figures. Revised version, more references and 1 figure added
Z.Phys.A357:317-324,1997
10.1007/s002180050248
null
hep-ph
null
Electro magnetic transition form factors for the excitation of the Delta33-resonance are evaluated in the Skyrme model. They crucially rely on rotationally induced deformations of the hedgehog soliton which are suppressed by two N_C-orders as compared to the leading parts of the isovector current. Partial photon coupling through vector mesons is included in a schematic way. Recoil corrections are approximated by a boost to the equal-velocity frame. The results for the photodecay amplitudes agree with experimental numbers and the shapes of M1, E2, C2 - transition form factors show essential features as observed in electro-excitation experiments.
[ { "created": "Thu, 18 Jul 1996 14:57:52 GMT", "version": "v1" }, { "created": "Tue, 29 Oct 1996 11:29:21 GMT", "version": "v2" } ]
2008-11-26
[ [ "Walliser", "H.", "", "Siegen University" ], [ "Holzwarth", "G.", "", "Siegen University" ] ]
Electro magnetic transition form factors for the excitation of the Delta33-resonance are evaluated in the Skyrme model. They crucially rely on rotationally induced deformations of the hedgehog soliton which are suppressed by two N_C-orders as compared to the leading parts of the isovector current. Partial photon coupling through vector mesons is included in a schematic way. Recoil corrections are approximated by a boost to the equal-velocity frame. The results for the photodecay amplitudes agree with experimental numbers and the shapes of M1, E2, C2 - transition form factors show essential features as observed in electro-excitation experiments.