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1211.4869
Arjun Menon
Spencer Chang and Arjun Menon
Discovering Nonstandard Higgs bosons in the H -> ZA Channel Decay to Multileptons
18 pages, 5 figures. Added references, revised Section 2, results unchanged
JHEP 1302 (2013) 152
10.1007/JHEP02(2013)152
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article we consider the possibility of observing nonstandard Higgs bosons in the H -> Z A -> Z tau+ tau- channel. We present three benchmark scenarios in the NMSSM where H -> ZA is the dominant decay mode for one of the nonstandard Higgs bosons while the lightest CP-even Higgs is Standard Model like. Using the latest CMS multilepton analysis based on 7 TeV LHC data, we put limits on the signal cross-section, which constrain leptophilic scenarios. Projecting to future LHC analyses with improvements in background modeling, we show that with O(30) fb^{-1} of data, such a multilepton analysis is very close to constraining our NMSSM benchmarks. As we illustrate with a toy model, for light A masses, the large boost of the A makes it inefficient to select two hadronic taus, since isolation and the transverse momenta are in tension. This efficiency could be improved by including boosted di-tau jets as an object in future multilepton analyses. We also discuss different methods to confirm this scenario by reconstruction of the m_H and m_A masses. In particular we consider the transverse mass distribution, collinear mass distribution and an analytical solution using trial masses.
[ { "created": "Tue, 20 Nov 2012 21:00:00 GMT", "version": "v1" }, { "created": "Wed, 13 Feb 2013 19:55:08 GMT", "version": "v2" } ]
2013-03-11
[ [ "Chang", "Spencer", "" ], [ "Menon", "Arjun", "" ] ]
In this article we consider the possibility of observing nonstandard Higgs bosons in the H -> Z A -> Z tau+ tau- channel. We present three benchmark scenarios in the NMSSM where H -> ZA is the dominant decay mode for one of the nonstandard Higgs bosons while the lightest CP-even Higgs is Standard Model like. Using the latest CMS multilepton analysis based on 7 TeV LHC data, we put limits on the signal cross-section, which constrain leptophilic scenarios. Projecting to future LHC analyses with improvements in background modeling, we show that with O(30) fb^{-1} of data, such a multilepton analysis is very close to constraining our NMSSM benchmarks. As we illustrate with a toy model, for light A masses, the large boost of the A makes it inefficient to select two hadronic taus, since isolation and the transverse momenta are in tension. This efficiency could be improved by including boosted di-tau jets as an object in future multilepton analyses. We also discuss different methods to confirm this scenario by reconstruction of the m_H and m_A masses. In particular we consider the transverse mass distribution, collinear mass distribution and an analytical solution using trial masses.
1803.03844
Subhasis Samanta
Subhasis Samanta, Sandeep Chatterjee and Bedangadas Mohanty
Exploring the hadron resonance gas phase on the QCD phase diagram
null
J. Phys. G 46, 065106 (2019)
10.1088/1361-6471/ab1a6b
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Lattice computations of strongly interacting matter at finite temperature $T$ and baryon chemical potential $\mu_B$ suggest that the QCD thermodynamics deep in the hadronic phase can be adequately modeled by an ideal hadron resonance gas (I-HRG). However, it is not clear where on the $(\mu_B, T)$ plane this description breaks down, making it essential to account for hadronic interactions and change in the nature of the degrees of freedom. We have studied several thermodynamic functions within the I-HRG model and try to identify the region of the QCD phase diagram where it becomes essential to include non-ideal effects into the I-HRG model. We work with only those thermodynamic quantities that show a monotonic rise with $T$ and $\mu_B$ in I-HRG. Their high temperature limiting values where QCD becomes simply a Stefan-Boltzmann (SB) gas of massless quarks and gluons is known. The rise of these quantities in I-HRG beyond the corresponding SB limit values indicate the need to include interactions into I-HRG to study QCD thermodynamics. This works as a guiding principle on the QCD phase diagram where interacting HRG can take over from I-HRG. For $\mu_B/T\leq2$, $\chi^Q_2$ shoots the SB limit at the smallest $T$, while for higher values of $\mu_B/T$,$C_{BS}=-3\chi^{BS}_{11}/\chi^S_2$ takes over. We further comment on the relative positions between the freezeout curve obtained by thermal fits to the measured hadron yields and the obtained line where I-HRG overshoots SB limit.
[ { "created": "Sat, 10 Mar 2018 17:40:57 GMT", "version": "v1" }, { "created": "Fri, 26 Apr 2019 15:33:32 GMT", "version": "v2" } ]
2019-05-10
[ [ "Samanta", "Subhasis", "" ], [ "Chatterjee", "Sandeep", "" ], [ "Mohanty", "Bedangadas", "" ] ]
Lattice computations of strongly interacting matter at finite temperature $T$ and baryon chemical potential $\mu_B$ suggest that the QCD thermodynamics deep in the hadronic phase can be adequately modeled by an ideal hadron resonance gas (I-HRG). However, it is not clear where on the $(\mu_B, T)$ plane this description breaks down, making it essential to account for hadronic interactions and change in the nature of the degrees of freedom. We have studied several thermodynamic functions within the I-HRG model and try to identify the region of the QCD phase diagram where it becomes essential to include non-ideal effects into the I-HRG model. We work with only those thermodynamic quantities that show a monotonic rise with $T$ and $\mu_B$ in I-HRG. Their high temperature limiting values where QCD becomes simply a Stefan-Boltzmann (SB) gas of massless quarks and gluons is known. The rise of these quantities in I-HRG beyond the corresponding SB limit values indicate the need to include interactions into I-HRG to study QCD thermodynamics. This works as a guiding principle on the QCD phase diagram where interacting HRG can take over from I-HRG. For $\mu_B/T\leq2$, $\chi^Q_2$ shoots the SB limit at the smallest $T$, while for higher values of $\mu_B/T$,$C_{BS}=-3\chi^{BS}_{11}/\chi^S_2$ takes over. We further comment on the relative positions between the freezeout curve obtained by thermal fits to the measured hadron yields and the obtained line where I-HRG overshoots SB limit.
hep-ph/9707266
Gunther Piller
G. Piller, G. Niesler and W. Weise
Diffractive Phenomena and Shadowing in Deep-Inelastic Scattering
12 pages Latex, 8 figures
Z.Phys. A358 (1997) 407-413
10.1007/s002180050348
TUM/T39-96-27
hep-ph
null
Shadowing effects in deep-inelastic lepton-nucleus scattering probe the mass spectrum of diffractive leptoproduction from individual nucleons. We explore this relationship using current experimental information on both processes. In recent data from the NMC and E665 collaboration, taken at small x << 0.1 and Q^2 < 1 GeV^2, shadowing is dominated by the diffractive excitation and coherent interaction of low mass vector mesons. If shadowing is explored at small x << 0.1 but large Q^2 >> 1 GeV^2 as discussed at HERA, the situation is different. Here dominant contributions come from the coherent interaction of diffractively produced heavy mass states. Furthermore we observe that the energy dependence of shadowing is directly related to the mass dependence of the diffractive production cross section for free nucleon targets.
[ { "created": "Mon, 7 Jul 1997 13:59:38 GMT", "version": "v1" } ]
2009-10-30
[ [ "Piller", "G.", "" ], [ "Niesler", "G.", "" ], [ "Weise", "W.", "" ] ]
Shadowing effects in deep-inelastic lepton-nucleus scattering probe the mass spectrum of diffractive leptoproduction from individual nucleons. We explore this relationship using current experimental information on both processes. In recent data from the NMC and E665 collaboration, taken at small x << 0.1 and Q^2 < 1 GeV^2, shadowing is dominated by the diffractive excitation and coherent interaction of low mass vector mesons. If shadowing is explored at small x << 0.1 but large Q^2 >> 1 GeV^2 as discussed at HERA, the situation is different. Here dominant contributions come from the coherent interaction of diffractively produced heavy mass states. Furthermore we observe that the energy dependence of shadowing is directly related to the mass dependence of the diffractive production cross section for free nucleon targets.
2401.15145
Sudip Jana
Evgeny Akhmedov, P. S. Bhupal Dev, Sudip Jana, Rabindra N. Mohapatra
Long-lived doubly charged scalars in the left-right symmetric model: catalyzed nuclear fusion and collider implications
10 pages + references, 6 figures, matches published version
Phys. Lett. B 852 (2024) 138616
10.1016/j.physletb.2024.138616
null
hep-ph hep-ex nucl-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
We show that the doubly charged scalar from the $SU(2)_R$-triplet Higgs field in the Left-Right Symmetric Model has its mass governed by a hidden symmetry so that its value can be much lower than the $SU(2)_R$ breaking scale. This makes it a long-lived particle while being consistent with all existing theoretical and experimental constraints. Such long-lived doubly charged scalars have the potential to trigger catalyzed fusion processes in light nuclei, which may have important applications for energy production. We show that it could also bear consequences on the excess of large ionization energy loss ($dE/dx$) recently observed in collider experiments.
[ { "created": "Fri, 26 Jan 2024 19:00:00 GMT", "version": "v1" }, { "created": "Sat, 6 Apr 2024 10:39:51 GMT", "version": "v2" } ]
2024-04-09
[ [ "Akhmedov", "Evgeny", "" ], [ "Dev", "P. S. Bhupal", "" ], [ "Jana", "Sudip", "" ], [ "Mohapatra", "Rabindra N.", "" ] ]
We show that the doubly charged scalar from the $SU(2)_R$-triplet Higgs field in the Left-Right Symmetric Model has its mass governed by a hidden symmetry so that its value can be much lower than the $SU(2)_R$ breaking scale. This makes it a long-lived particle while being consistent with all existing theoretical and experimental constraints. Such long-lived doubly charged scalars have the potential to trigger catalyzed fusion processes in light nuclei, which may have important applications for energy production. We show that it could also bear consequences on the excess of large ionization energy loss ($dE/dx$) recently observed in collider experiments.
hep-ph/0304152
Ralf Hofmann
Ralf Hofmann
Thermodynamic gauge-theory cascade
25 pages, 6 figures, 1 reference added, minor corrections in text, errors in Sec. 3.2 corrected, PRD version
Phys.Rev. D68 (2003) 065015
10.1103/PhysRevD.68.065015
HD-THEP-03-20
hep-ph hep-th
null
It is proposed that the cooling of a thermalized SU($N$) gauge theory can be formulated in terms of a cascade involving three effective theories with successively reduced (and spontaneously broken) gauge symmetries, SU($N$) $\to$ U(1)$^{N-1}$ $\to$ Z$_N$. The approach is based on the assumption that away from a phase transition the bulk of the quantum interaction inherent to the system is implicitly encoded in the (incomplete) classical dynamics of a collective part made of low-energy condensed degrees of freedom. The properties of (some of the) statistically fluctuating fields are determined by these condensate(s). This leads to a quasi-particle description at tree-level. It appears that radiative corrections, which are sizable at large gauge coupling, do not change the tree-level picture qualitatively. The thermodynamic self-consistency of the quasi-particle approach implies nonperturbative evolution equations for the associated masses. The temperature dependence of these masses, in turn, determine the evolution of the gauge coupling(s). The hot gauge system approaches the behavior of an ideal gas of massless gluons at asymptotically large temperature. A negative equation of state is possible at a stage where the system is about to settle into the phase of the (spontaneously broken) Z$_N$ symmetry.
[ { "created": "Tue, 15 Apr 2003 23:46:37 GMT", "version": "v1" }, { "created": "Fri, 23 May 2003 12:02:38 GMT", "version": "v2" }, { "created": "Thu, 14 Aug 2003 12:52:26 GMT", "version": "v3" } ]
2009-11-10
[ [ "Hofmann", "Ralf", "" ] ]
It is proposed that the cooling of a thermalized SU($N$) gauge theory can be formulated in terms of a cascade involving three effective theories with successively reduced (and spontaneously broken) gauge symmetries, SU($N$) $\to$ U(1)$^{N-1}$ $\to$ Z$_N$. The approach is based on the assumption that away from a phase transition the bulk of the quantum interaction inherent to the system is implicitly encoded in the (incomplete) classical dynamics of a collective part made of low-energy condensed degrees of freedom. The properties of (some of the) statistically fluctuating fields are determined by these condensate(s). This leads to a quasi-particle description at tree-level. It appears that radiative corrections, which are sizable at large gauge coupling, do not change the tree-level picture qualitatively. The thermodynamic self-consistency of the quasi-particle approach implies nonperturbative evolution equations for the associated masses. The temperature dependence of these masses, in turn, determine the evolution of the gauge coupling(s). The hot gauge system approaches the behavior of an ideal gas of massless gluons at asymptotically large temperature. A negative equation of state is possible at a stage where the system is about to settle into the phase of the (spontaneously broken) Z$_N$ symmetry.
hep-ph/9403322
Michael Tung
Michael M. Tung
O(alpha_s) Longitudinal Spin Polarization in Heavy-Quark Production
13 pages, LaTeX, 5 tables and 2 figures are appended in uuencoded postscript format, revised version (changes made to appear in Phys. Rev. D)
Phys.Rev.D52:1353-1358,1995
10.1103/PhysRevD.52.1353
FTUV/94-4 (University of Valencia preprint)
hep-ph
null
The massive one-loop {\it QCD} corrections to the production cross sections of We present the massive one-loop {\it QCD} corrections to the production cross sections of polarized quarks in the annihilation process $e^+e^-\to q\bar{q}(g)$ for bottom, top, and charm quarks. From the full analytical expressions for the production cross sections, Schwinger-type interpolation formulae for all parity-parity combinations $(VV, V\!A, AA)$ are derived. The parity-odd interpolation formula contains the correct limit for vanishing quark masses taking into account a residual coupling of left- and right-chiral states in the massless theory. Numerical results for the total cross section and the longitudinal spin polarization demonstrate the accuracy of the interpolation formulae.
[ { "created": "Mon, 21 Mar 1994 15:31:00 GMT", "version": "v1" }, { "created": "Tue, 4 Jul 1995 19:26:15 GMT", "version": "v2" } ]
2010-01-15
[ [ "Tung", "Michael M.", "" ] ]
The massive one-loop {\it QCD} corrections to the production cross sections of We present the massive one-loop {\it QCD} corrections to the production cross sections of polarized quarks in the annihilation process $e^+e^-\to q\bar{q}(g)$ for bottom, top, and charm quarks. From the full analytical expressions for the production cross sections, Schwinger-type interpolation formulae for all parity-parity combinations $(VV, V\!A, AA)$ are derived. The parity-odd interpolation formula contains the correct limit for vanishing quark masses taking into account a residual coupling of left- and right-chiral states in the massless theory. Numerical results for the total cross section and the longitudinal spin polarization demonstrate the accuracy of the interpolation formulae.
hep-ph/0506019
XiaoHu Mo
C.Z.Yuan, X.H.Mo and P.Wang
Baryon Antibaryon Nonets
5 pages, 1 figure
Phys.Lett. B626 (2005) 95-100
10.1016/j.physletb.2005.08.046
null
hep-ph
null
The baryon-antibaryon SU(3) nonets are proposed as a scheme to classify the increased number of experimentally observed enhancements near the baryon antibaryon mass threshold. The scheme is similar to the Fermi-Yang-Sakata model, which was put forth about fifty years ago in explaining the mesons observed at that time. According to the present scheme, many new baryon-antibaryon bound states are predicted, and their possible productions in quarkonium decays and B decays are suggested for experimental search.
[ { "created": "Fri, 3 Jun 2005 05:39:49 GMT", "version": "v1" } ]
2009-11-11
[ [ "Yuan", "C. Z.", "" ], [ "Mo", "X. H.", "" ], [ "Wang", "P.", "" ] ]
The baryon-antibaryon SU(3) nonets are proposed as a scheme to classify the increased number of experimentally observed enhancements near the baryon antibaryon mass threshold. The scheme is similar to the Fermi-Yang-Sakata model, which was put forth about fifty years ago in explaining the mesons observed at that time. According to the present scheme, many new baryon-antibaryon bound states are predicted, and their possible productions in quarkonium decays and B decays are suggested for experimental search.
1510.02567
Barbara Pasquini
M. Burkardt (New Mexico State U.) and B. Pasquini (Pavia U. and INFN-Pavia)
Modelling the nucleon structure
16 pages, 8 figures; contribution the EPJA Special Issue on "3D Structure of the Nucleon"; V2 references corrected
null
10.1140/epja/i2016-16161-7
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the status of our understanding of nucleon structure based on the modelling of different kinds of parton distributions. We use the concept of generalized transverse momentum dependent parton distributions and Wigner distributions, which combine the features of transverse-momentum dependent parton distributions and generalized parton distributions. We revisit various quark models which account for different aspects of these parton distributions. We then identify applications of these distributions to gain a simple interpretation of key properties of the quark and gluon dynamics in the nucleon.
[ { "created": "Fri, 9 Oct 2015 04:27:20 GMT", "version": "v1" }, { "created": "Sat, 7 May 2016 06:53:00 GMT", "version": "v2" } ]
2016-07-20
[ [ "Burkardt", "M.", "", "New Mexico State U." ], [ "Pasquini", "B.", "", "Pavia U. and\n INFN-Pavia" ] ]
We review the status of our understanding of nucleon structure based on the modelling of different kinds of parton distributions. We use the concept of generalized transverse momentum dependent parton distributions and Wigner distributions, which combine the features of transverse-momentum dependent parton distributions and generalized parton distributions. We revisit various quark models which account for different aspects of these parton distributions. We then identify applications of these distributions to gain a simple interpretation of key properties of the quark and gluon dynamics in the nucleon.
hep-ph/0305044
Guido Marandella
Riccardo Barbieri, Guido Marandella and Michele Papucci
The Higgs mass as a function of the compactification scale
22 pages, 6 figures
Nucl.Phys.B668:273-292,2003
10.1016/S0550-3213(03)00573-X
null
hep-ph
null
We calculate to a few percent precision the Higgs potential in a model with supersymmetry broken by boundary conditions on an extra-dimension, compactified to a segment of length $L$, and a top quark quasi-localized on one of the two boundaries. 1/L alone, in the range 2-4 TeV, determines the Higgs mass, in the range 110-125 GeV, and the spectrum of gauginos, higgsinos and of the third-generation squarks. Lower values of 1/L cannot be excluded, with a progressive delocalization of the top quark.
[ { "created": "Mon, 5 May 2003 12:56:08 GMT", "version": "v1" } ]
2014-11-17
[ [ "Barbieri", "Riccardo", "" ], [ "Marandella", "Guido", "" ], [ "Papucci", "Michele", "" ] ]
We calculate to a few percent precision the Higgs potential in a model with supersymmetry broken by boundary conditions on an extra-dimension, compactified to a segment of length $L$, and a top quark quasi-localized on one of the two boundaries. 1/L alone, in the range 2-4 TeV, determines the Higgs mass, in the range 110-125 GeV, and the spectrum of gauginos, higgsinos and of the third-generation squarks. Lower values of 1/L cannot be excluded, with a progressive delocalization of the top quark.
1506.00020
Stephen Barr
Stephen M. Barr and Heng-Yu Chen
A Single Source for All Flavor Violation
11 pages, no figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a model proposed in 2012, all flavor mixing has a single source and is governed by a single "master matrix." This model was shown to give several predictions for quark and lepton masses and mixing angles and for mixing angles within SU(5) multiplets that are observable in proton decay. Here it is shown that the same master matrix controls the flavor-changing processes mediated by a singlet scalar that exists in the model, giving predictions for tau to mu + gamma, tau to e + gamma, and mu to e + gamma.
[ { "created": "Fri, 29 May 2015 20:18:46 GMT", "version": "v1" } ]
2015-06-02
[ [ "Barr", "Stephen M.", "" ], [ "Chen", "Heng-Yu", "" ] ]
In a model proposed in 2012, all flavor mixing has a single source and is governed by a single "master matrix." This model was shown to give several predictions for quark and lepton masses and mixing angles and for mixing angles within SU(5) multiplets that are observable in proton decay. Here it is shown that the same master matrix controls the flavor-changing processes mediated by a singlet scalar that exists in the model, giving predictions for tau to mu + gamma, tau to e + gamma, and mu to e + gamma.
2110.13920
Yitian Sun
Yitian Sun, Katelin Schutz, Anjali Nambrath, Calvin Leung, Kiyoshi Masui
Axion dark matter-induced echo of supernova remnants
15 pages, 5 figures. V2 updated to match published version; conclusions unchanged
null
10.1103/PhysRevD.105.063007
MIT-CTP/5343
hep-ph astro-ph.GA astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Axions are a theoretically promising dark matter (DM) candidate. In the presence of radiation from bright astrophysical sources at radio frequencies, nonrelativistic DM axions can undergo stimulated decay to two nearly back-to-back photons, meaning that bright sources of radio waves will have a counterimage ("gegenschein") in nearly the exact opposite spatial direction. The counterimage will be spectrally distinct from backgrounds, taking the form of a narrow radio line centered at $\nu = m_a/4\pi$ with a width determined by Doppler broadening in the DM halo, $\Delta \nu/\nu \sim 10^{-3}$. In this work, we show that the axion decay-induced echoes of supernova remnants may be bright enough to be detectable. Their non-detection may be able to set the strongest limits to date on axion DM in the $\sim 1-10 \, \mu$eV mass range where there are gaps in coverage from existing experiments.
[ { "created": "Tue, 26 Oct 2021 18:00:00 GMT", "version": "v1" }, { "created": "Thu, 24 Mar 2022 06:52:05 GMT", "version": "v2" } ]
2022-03-25
[ [ "Sun", "Yitian", "" ], [ "Schutz", "Katelin", "" ], [ "Nambrath", "Anjali", "" ], [ "Leung", "Calvin", "" ], [ "Masui", "Kiyoshi", "" ] ]
Axions are a theoretically promising dark matter (DM) candidate. In the presence of radiation from bright astrophysical sources at radio frequencies, nonrelativistic DM axions can undergo stimulated decay to two nearly back-to-back photons, meaning that bright sources of radio waves will have a counterimage ("gegenschein") in nearly the exact opposite spatial direction. The counterimage will be spectrally distinct from backgrounds, taking the form of a narrow radio line centered at $\nu = m_a/4\pi$ with a width determined by Doppler broadening in the DM halo, $\Delta \nu/\nu \sim 10^{-3}$. In this work, we show that the axion decay-induced echoes of supernova remnants may be bright enough to be detectable. Their non-detection may be able to set the strongest limits to date on axion DM in the $\sim 1-10 \, \mu$eV mass range where there are gaps in coverage from existing experiments.
hep-ph/9411391
Dr. Joon Ha Kim
Joon Ha Kim, Sooman Yee and Hyun Kyu Lee
Characteristics of QCD Phase Transitions in an Extended Skyrme Model on $S^3$
8 text pages (Latex) and 5 figures included
Phys.Rev.D53:1715-1718,1996
10.1103/PhysRevD.53.1715
HYUPT-94/12
hep-ph nucl-th
null
We study the characteristics of the QCD phase transitions in dense hadronic matter using the Skyrme model constructed on S^3. We find numerically the localized solutions on $S^3$ using the extended Skyrme model which implements correctly the scale symmetry of QCD. The transition from the localized phase to the delocalized phase is found to be of first order at the critical radius of the hypersphere, $L_c$. The chiral restoration and the gluon decondensation also take place at the same critical size.
[ { "created": "Fri, 25 Nov 1994 18:26:01 GMT", "version": "v1" } ]
2009-09-25
[ [ "Kim", "Joon Ha", "" ], [ "Yee", "Sooman", "" ], [ "Lee", "Hyun Kyu", "" ] ]
We study the characteristics of the QCD phase transitions in dense hadronic matter using the Skyrme model constructed on S^3. We find numerically the localized solutions on $S^3$ using the extended Skyrme model which implements correctly the scale symmetry of QCD. The transition from the localized phase to the delocalized phase is found to be of first order at the critical radius of the hypersphere, $L_c$. The chiral restoration and the gluon decondensation also take place at the same critical size.
2202.03900
Li-Ping He
Eric Braaten, Li-Ping He, Kevin Ingles, Jun Jiang
Triangle Singularity in the Production of $T_{cc}^+$(3875) and a Soft Pion
44 pages, 13 figures
Phys.Rev.D 106 (2022) 3, 034033
10.1103/PhysRevD.106.034033
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The double-charm tetraquark meson $T_{cc}^+(3875)$ can be produced in high-energy proton-proton collisions by the creation of the charm mesons $D^{*+} D^0$ at short distances followed by their binding into $T_{cc}^+$. The $T_{cc}^+$ can also be produced by the creation of $D^{*+} D^{*+}$ at short distances followed by their rescattering into $T_{cc}^+ \pi^+$. A charm-meson triangle singularity produces a narrow peak in the $T_{cc}^+ \pi^+$ invariant mass distribution 6.1 MeV above the threshold with a width of about 1 MeV. Well beyond the peak, the differential cross section decreases with the invariant kinetic energy $E$ of $T_{cc}^+ \pi^+$ as $E^{-1/2}$. The fraction of $T_{cc}^+$ that are accompanied by $\pi^+$ with $E< m_\pi$ is estimated to be roughly 3%. The fraction of $T_{cc}^+$ events with $T_{cc}^+ \pi^+$ in the narrow peak from the triangle singularity could be comparable.
[ { "created": "Tue, 8 Feb 2022 14:43:28 GMT", "version": "v1" }, { "created": "Fri, 11 Feb 2022 15:30:23 GMT", "version": "v2" }, { "created": "Tue, 30 Aug 2022 12:10:07 GMT", "version": "v3" } ]
2022-08-31
[ [ "Braaten", "Eric", "" ], [ "He", "Li-Ping", "" ], [ "Ingles", "Kevin", "" ], [ "Jiang", "Jun", "" ] ]
The double-charm tetraquark meson $T_{cc}^+(3875)$ can be produced in high-energy proton-proton collisions by the creation of the charm mesons $D^{*+} D^0$ at short distances followed by their binding into $T_{cc}^+$. The $T_{cc}^+$ can also be produced by the creation of $D^{*+} D^{*+}$ at short distances followed by their rescattering into $T_{cc}^+ \pi^+$. A charm-meson triangle singularity produces a narrow peak in the $T_{cc}^+ \pi^+$ invariant mass distribution 6.1 MeV above the threshold with a width of about 1 MeV. Well beyond the peak, the differential cross section decreases with the invariant kinetic energy $E$ of $T_{cc}^+ \pi^+$ as $E^{-1/2}$. The fraction of $T_{cc}^+$ that are accompanied by $\pi^+$ with $E< m_\pi$ is estimated to be roughly 3%. The fraction of $T_{cc}^+$ events with $T_{cc}^+ \pi^+$ in the narrow peak from the triangle singularity could be comparable.
0811.3972
Anosh Joseph
Anosh Joseph
Particle phenomenology on noncommutative spacetime
10 pages, 3 figures. Published version
Phys.Rev.D79:096004,2009
10.1103/PhysRevD.79.096004
SU-4252-876
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce particle phenomenology on the noncommutative spacetime called the Groenewold-Moyal plane. The length scale of spcetime noncommutativity is constrained from the CPT violation measurements in $K^{0}-\bar{K}^{0}$ system and $g-2$ difference of $\mu^+ - \mu^-$. The $K^{0}-\bar{K}^{0}$ system provides an upper bound on the length scale of spacetime noncommutativity of the order of $10^{-32} \textrm{m}$, corresponding to a lower energy bound $E$ of the order of $E \gtrsim 10^{16}\textrm{GeV}$. The $g-2$ difference of $\mu^+ - \mu^-$ constrains the noncommutativity length scale to be of the order of $10^{-20} \textrm{m}$, corresponding to a lower energy bound $E$ of the order of $E \gtrsim 10^{3}\textrm{GeV}$. We also present the phenomenology of the electromagnetic interaction of electrons and nucleons at the tree level in the noncommutative spacetime. We show that the distributions of charge and magnetization of nucleons are affected by spacetime noncommutativity. The analytic properties of electromagnetic form factors are also changed and it may give rise to interesting experimental signals.
[ { "created": "Mon, 24 Nov 2008 22:09:56 GMT", "version": "v1" }, { "created": "Tue, 12 May 2009 14:26:02 GMT", "version": "v2" } ]
2009-05-22
[ [ "Joseph", "Anosh", "" ] ]
We introduce particle phenomenology on the noncommutative spacetime called the Groenewold-Moyal plane. The length scale of spcetime noncommutativity is constrained from the CPT violation measurements in $K^{0}-\bar{K}^{0}$ system and $g-2$ difference of $\mu^+ - \mu^-$. The $K^{0}-\bar{K}^{0}$ system provides an upper bound on the length scale of spacetime noncommutativity of the order of $10^{-32} \textrm{m}$, corresponding to a lower energy bound $E$ of the order of $E \gtrsim 10^{16}\textrm{GeV}$. The $g-2$ difference of $\mu^+ - \mu^-$ constrains the noncommutativity length scale to be of the order of $10^{-20} \textrm{m}$, corresponding to a lower energy bound $E$ of the order of $E \gtrsim 10^{3}\textrm{GeV}$. We also present the phenomenology of the electromagnetic interaction of electrons and nucleons at the tree level in the noncommutative spacetime. We show that the distributions of charge and magnetization of nucleons are affected by spacetime noncommutativity. The analytic properties of electromagnetic form factors are also changed and it may give rise to interesting experimental signals.
hep-ph/9812529
Vladimir Smirnov
V.A. Smirnov and E.R. Rakhmetov
The strategy of regions for asymptotic expansion of two-loop vertex Feynman diagrams
9 pages, LaTeX with axodraw.sty
Theor.Math.Phys. 120 (1999) 870-875; Teor.Mat.Fiz. 120 (1999) 64-71
10.1007/BF02557396
NPI MSU 98-54/555
hep-ph hep-th
null
General prescriptions for evaluation of coefficients at arbitrary powers and logarithms in the asymptotic expansion of Feynman diagrams in the Sudakov limit are discussed and illustrated by two-loop examples. Peculiarities connected with evaluation of individual terms of the expansion, in particular, the introduction of auxiliary analytic regularization, are characterized.
[ { "created": "Wed, 30 Dec 1998 20:06:40 GMT", "version": "v1" } ]
2009-10-31
[ [ "Smirnov", "V. A.", "" ], [ "Rakhmetov", "E. R.", "" ] ]
General prescriptions for evaluation of coefficients at arbitrary powers and logarithms in the asymptotic expansion of Feynman diagrams in the Sudakov limit are discussed and illustrated by two-loop examples. Peculiarities connected with evaluation of individual terms of the expansion, in particular, the introduction of auxiliary analytic regularization, are characterized.
2101.05528
Oliver Gould
Oliver Gould
Real scalar phase transitions: a nonperturbative analysis
43 pages, 14 figures
JHEP 04 (2021) 057
10.1007/JHEP04(2021)057
HIP-2021-2/TH
hep-ph astro-ph.CO cond-mat.stat-mech hep-lat hep-th
http://creativecommons.org/licenses/by/4.0/
We study the thermal phase transitions of a generic real scalar field, without a $Z_2$-symmetry, referred to variously as an inert, sterile or singlet scalar, or $\phi^3+\phi^4$ theory. Such a scalar field arises in a wide range of models, including as the inflaton, or as a portal to the dark sector. At high temperatures, we perform dimensional reduction, matching to an effective theory in three dimensions, which we then study both perturbatively to three-loop order and on the lattice. For strong first-order transitions, with large tree-level cubic couplings, our lattice Monte-Carlo simulations agree with perturbation theory within error. However, as the size of the cubic coupling decreases, relative to the quartic coupling, perturbation theory becomes less and less reliable, breaking down completely in the approach to the $Z_2$-symmetric limit, in which the transition is of second order. Notwithstanding, the renormalisation group is shown to significantly extend the validity of perturbation theory. Throughout, our calculations are made as explicit as possible so that this article may serve as a guide for similar calculations in other theories.
[ { "created": "Thu, 14 Jan 2021 10:01:50 GMT", "version": "v1" }, { "created": "Mon, 12 Apr 2021 15:48:23 GMT", "version": "v2" } ]
2021-04-13
[ [ "Gould", "Oliver", "" ] ]
We study the thermal phase transitions of a generic real scalar field, without a $Z_2$-symmetry, referred to variously as an inert, sterile or singlet scalar, or $\phi^3+\phi^4$ theory. Such a scalar field arises in a wide range of models, including as the inflaton, or as a portal to the dark sector. At high temperatures, we perform dimensional reduction, matching to an effective theory in three dimensions, which we then study both perturbatively to three-loop order and on the lattice. For strong first-order transitions, with large tree-level cubic couplings, our lattice Monte-Carlo simulations agree with perturbation theory within error. However, as the size of the cubic coupling decreases, relative to the quartic coupling, perturbation theory becomes less and less reliable, breaking down completely in the approach to the $Z_2$-symmetric limit, in which the transition is of second order. Notwithstanding, the renormalisation group is shown to significantly extend the validity of perturbation theory. Throughout, our calculations are made as explicit as possible so that this article may serve as a guide for similar calculations in other theories.
0802.0381
Tamas Biro S
T.S.Biro, K.Urmossy and G.G.Barnafoldi
Pion and Kaon Spectra from Distributed Mass Quark Matter
Talk given at SQM 2007
J.Phys.G35:044012,2008
10.1088/0954-3899/35/4/044012
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
After discussing some hints for possible masses of quasiparticles in quark matter on the basis of lattice equation of state, we present pion and kaon transverse spectra obtained by recombining quarks with distributed mass and thermal cut power-law momenta as well as fragmenting by NLO pQCD with intrinsic $k_T$ {and nuclear} broadening.
[ { "created": "Mon, 4 Feb 2008 11:20:14 GMT", "version": "v1" } ]
2008-11-26
[ [ "Biro", "T. S.", "" ], [ "Urmossy", "K.", "" ], [ "Barnafoldi", "G. G.", "" ] ]
After discussing some hints for possible masses of quasiparticles in quark matter on the basis of lattice equation of state, we present pion and kaon transverse spectra obtained by recombining quarks with distributed mass and thermal cut power-law momenta as well as fragmenting by NLO pQCD with intrinsic $k_T$ {and nuclear} broadening.
2007.15006
Wen Yin
Joerg Jaeckel and Wen Yin
Boosted Neutrinos and Relativistic Dark Particles as Messengers from Reheating
38pages, 7figures
null
10.1088/1475-7516/2021/02/044
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Usually information from early eras such as reheating is hard to come by. In this paper we argue that, given the right circumstances, right-handed sterile neutrinos decaying to left-handed active ones at relatively late times can carry information from reheating by propagating freely over the thermal history. For not too small mixing angles, suitable right-handed neutrino masses are around ${\cal O}$(MeV-GeV). We identify the typical spectra and argue that they provide information on the ratio of the inflaton mass to the reheating temperature. This primordial neutrino signal can be strong enough that it can be detected in IceCube. More speculatively, for a reheating temperature and inflaton mass satisfying $T_R={\cal O}(1-100)\, {\rm MeV}$, and $m_\phi={\cal O}(10^{16-19})\,$GeV they may even explain the observed PeV events. Also more general relativistic dark particles can play the role of such messengers, potentially not only allowing for the PeV events but also alleviating the $H_0$-tension .
[ { "created": "Wed, 29 Jul 2020 18:00:01 GMT", "version": "v1" } ]
2021-03-03
[ [ "Jaeckel", "Joerg", "" ], [ "Yin", "Wen", "" ] ]
Usually information from early eras such as reheating is hard to come by. In this paper we argue that, given the right circumstances, right-handed sterile neutrinos decaying to left-handed active ones at relatively late times can carry information from reheating by propagating freely over the thermal history. For not too small mixing angles, suitable right-handed neutrino masses are around ${\cal O}$(MeV-GeV). We identify the typical spectra and argue that they provide information on the ratio of the inflaton mass to the reheating temperature. This primordial neutrino signal can be strong enough that it can be detected in IceCube. More speculatively, for a reheating temperature and inflaton mass satisfying $T_R={\cal O}(1-100)\, {\rm MeV}$, and $m_\phi={\cal O}(10^{16-19})\,$GeV they may even explain the observed PeV events. Also more general relativistic dark particles can play the role of such messengers, potentially not only allowing for the PeV events but also alleviating the $H_0$-tension .
1309.1689
Leonard Lesniak
Leonard Lesniak, Piotr Zenczykowski
Dalitz-plot dependence of CP asymmetry in B+- --> K+- K+ K- decays
11 pages, 6 figures
Physics Letters B737(2014)201
10.1016/j.physletb.2014.08.052
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A large CP asymmetry predicted recently in the framework of the QCD factorization model for the B+- --> K+- K+ K- decays in the range of the K+ K- invariant masses above the phi(1020) resonance has been confirmed by the LHCb Collaboration. We discuss the emergence and size of this asymmetry in an extended model involving S- and P-waves together with the contribution from the D-wave f2(1270) resonance and compare our model with the experimental data of the LHCb and BABAR Collaborations.
[ { "created": "Fri, 6 Sep 2013 16:13:15 GMT", "version": "v1" }, { "created": "Tue, 16 Sep 2014 14:34:30 GMT", "version": "v2" } ]
2014-09-17
[ [ "Lesniak", "Leonard", "" ], [ "Zenczykowski", "Piotr", "" ] ]
A large CP asymmetry predicted recently in the framework of the QCD factorization model for the B+- --> K+- K+ K- decays in the range of the K+ K- invariant masses above the phi(1020) resonance has been confirmed by the LHCb Collaboration. We discuss the emergence and size of this asymmetry in an extended model involving S- and P-waves together with the contribution from the D-wave f2(1270) resonance and compare our model with the experimental data of the LHCb and BABAR Collaborations.
hep-ph/9908386
Sinead Ryan
Sinead Ryan
Lattice determinations of the strange quark mass
7 pages, invited talk at KAON'99, University of Chicago, June 21-26, 1999, typos corrected
null
null
Fermilab-Conf-99/222-T
hep-ph hep-lat
null
Lattice calculations of the mass of the strange quark are reviewed. In particular, the reason for the spread in values is explained with emphasis on the effects that recently implemented improvements have had on the lattice determinations.
[ { "created": "Tue, 17 Aug 1999 16:07:52 GMT", "version": "v1" }, { "created": "Wed, 18 Aug 1999 19:10:24 GMT", "version": "v2" } ]
2007-05-23
[ [ "Ryan", "Sinead", "" ] ]
Lattice calculations of the mass of the strange quark are reviewed. In particular, the reason for the spread in values is explained with emphasis on the effects that recently implemented improvements have had on the lattice determinations.
1705.05282
Hisaki Hatanaka
Shuichiro Funatsu, Hisaki Hatanaka, Yutaka Hosotani and Yuta Orikasa
Distinct signals of the gauge-Higgs unification in $e^+e^-$ collider experiments
16 pages, 5 figures, 7 tables (v3) numerical evaluations renewed, comments and references added, 4 tables added
Physics Letters B 775 (2017) 297-302
10.1016/j.physletb.2017.10.068
KEK-TH-1978, OU-HET 934
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Effects of Kaluza-Klein excited neutral vector bosons ($Z'$ bosons) in the gauge-Higgs unification on $e^+e^- \to \bar{q}q, \ell^+\ell^-$ cross sections are studied, particularly in future $e^+ e^-$ collider experiments with polarized beams. Significant deviations in the energy and polarization dependence in $\sigma(\mu^+\mu^-)$, the lepton forward-backward asymmetry, $R_b(\mu) \equiv \sigma(\bar{b}b)/\sigma(\mu^+\mu^-)$ and the left-right asymmetry from the standard model are predicted.
[ { "created": "Mon, 15 May 2017 15:08:41 GMT", "version": "v1" }, { "created": "Wed, 19 Jul 2017 14:44:57 GMT", "version": "v2" }, { "created": "Thu, 5 Oct 2017 02:43:32 GMT", "version": "v3" } ]
2017-11-20
[ [ "Funatsu", "Shuichiro", "" ], [ "Hatanaka", "Hisaki", "" ], [ "Hosotani", "Yutaka", "" ], [ "Orikasa", "Yuta", "" ] ]
Effects of Kaluza-Klein excited neutral vector bosons ($Z'$ bosons) in the gauge-Higgs unification on $e^+e^- \to \bar{q}q, \ell^+\ell^-$ cross sections are studied, particularly in future $e^+ e^-$ collider experiments with polarized beams. Significant deviations in the energy and polarization dependence in $\sigma(\mu^+\mu^-)$, the lepton forward-backward asymmetry, $R_b(\mu) \equiv \sigma(\bar{b}b)/\sigma(\mu^+\mu^-)$ and the left-right asymmetry from the standard model are predicted.
1306.4655
Christophe Grojean
Christophe Grojean, Oleksii Matsedonskyi, Giuliano Panico
Light top partners and precision physics
55 pages. V2: Typos corrected and references added. Matches published version
null
10.1007/JHEP10(2013)160
CERN-PH-TH/2013-144
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the corrections to the precision EW observables in minimal composite Higgs models by using a general effective parametrization which also includes the lightest fermionic resonances. A new, possibly large, logarithmically divergent contribution to S is identified, which comes purely from the strong dynamics. It can be interpreted as a running of S induced by the non-renormalizable Higgs interactions due to the non-linear sigma-model structure. As expected, the corrections to the T parameter coming from fermion loops are finite and dominated by the contributions of the lightest composite states. The fit of the oblique parameters suggests a rather stringent lower bound on the sigma-model scale f > 750GeV. The corrections to the Z bL bL vertex coming from the lowest-order operators in the effective Lagrangian are finite and somewhat correlated to the corrections to T. Large additional contributions are generated by contact interactions with 4 composite fermions. In this case a logarithmic divergence can be generated and the correlation with T is removed. We also analyze the tree-level corrections to the top couplings, which are expected to be large due to the sizable degree of compositeness of the third generation quarks. We find that for a moderate amount of tuning the deviation in Vtb can be of order 5% while the distortion of the Z tL tL vertex can be 10%.
[ { "created": "Wed, 19 Jun 2013 19:34:59 GMT", "version": "v1" }, { "created": "Mon, 4 Nov 2013 10:51:42 GMT", "version": "v2" } ]
2015-06-16
[ [ "Grojean", "Christophe", "" ], [ "Matsedonskyi", "Oleksii", "" ], [ "Panico", "Giuliano", "" ] ]
We analyze the corrections to the precision EW observables in minimal composite Higgs models by using a general effective parametrization which also includes the lightest fermionic resonances. A new, possibly large, logarithmically divergent contribution to S is identified, which comes purely from the strong dynamics. It can be interpreted as a running of S induced by the non-renormalizable Higgs interactions due to the non-linear sigma-model structure. As expected, the corrections to the T parameter coming from fermion loops are finite and dominated by the contributions of the lightest composite states. The fit of the oblique parameters suggests a rather stringent lower bound on the sigma-model scale f > 750GeV. The corrections to the Z bL bL vertex coming from the lowest-order operators in the effective Lagrangian are finite and somewhat correlated to the corrections to T. Large additional contributions are generated by contact interactions with 4 composite fermions. In this case a logarithmic divergence can be generated and the correlation with T is removed. We also analyze the tree-level corrections to the top couplings, which are expected to be large due to the sizable degree of compositeness of the third generation quarks. We find that for a moderate amount of tuning the deviation in Vtb can be of order 5% while the distortion of the Z tL tL vertex can be 10%.
hep-ph/0312312
Jeff Forshaw
Rikard Enberg, Jeff Forshaw, Leszek Motyka and Gavin Poludniowski
Diffractive Vector Meson Production with a Large Momentum Transfer
Talk presented at EPS2003, Aachen, July 2003. 4 pages
Eur.Phys.J.C33:s512-s514,2004
10.1140/epjcd/s2004-03-1584-y
null
hep-ph
null
We summarise recent progress in the computation of helicity amplitudes for diffractive vector meson production at large momentum transfer and their comparison to data collected at the HERA collider.
[ { "created": "Mon, 22 Dec 2003 14:20:42 GMT", "version": "v1" } ]
2008-11-26
[ [ "Enberg", "Rikard", "" ], [ "Forshaw", "Jeff", "" ], [ "Motyka", "Leszek", "" ], [ "Poludniowski", "Gavin", "" ] ]
We summarise recent progress in the computation of helicity amplitudes for diffractive vector meson production at large momentum transfer and their comparison to data collected at the HERA collider.
hep-ph/9509387
Smirnov A. Y.
A.Yu. Smirnov
Solar Neutrinos: Expecting 1996
14 pages, LaTeX, Talk given at the International workshop on Particle Physics: Present and Future, Valencia, June 1995
null
null
YITP-95-3
hep-ph
null
These are remarks (mainly on the solar neutrinos) written in anticipation of 1996 - the year which can be crucial for the neutrino physics. Recent results on solar neutrinos are discussed. The topics include: (solar) model independent approach to the solar neutrino problem, status of different solutions of the problem, standard and non-standard scenarios of the lepton mixing, light singlet fermions and the neutrino phenomenology.
[ { "created": "Tue, 26 Sep 1995 01:46:57 GMT", "version": "v1" } ]
2007-05-23
[ [ "Smirnov", "A. Yu.", "" ] ]
These are remarks (mainly on the solar neutrinos) written in anticipation of 1996 - the year which can be crucial for the neutrino physics. Recent results on solar neutrinos are discussed. The topics include: (solar) model independent approach to the solar neutrino problem, status of different solutions of the problem, standard and non-standard scenarios of the lepton mixing, light singlet fermions and the neutrino phenomenology.
0807.3736
Keith Olive
John Ellis, Keith A. Olive, and Yudi Santoso
Sneutrino NLSP Scenarios in the NUHM with Gravitino Dark Matter
29 pages, 13 eps figures
JHEP 0810:005,2008
10.1088/1126-6708/2008/10/005
CERN-PH-TH/2008-159, UMN-TH-2708/08, FTPI-MINN-08/28, IPPP/08/53, DCPT/08/106
hep-ph astro-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze scenarios in which some flavour of sneutrino is the next-to-lightest supersymmetric particle (NLSP), assuming that the gravitino is the lightest supersymmetric particle (LSP) and provides the cold dark matter. Such scenarios do not arise in the constrained supersymmetric extension of the Standard Model (CMSSM) with universal gaugino and scalar masses input at the GUT scale. However, models with non-universal Higgs masses (NUHM) do allow scenarios with a sneutrino NLSP, which are quite generic. We illustrate how such scenarios may arise, analyze the possible metastable sneutrino lifetime, and explore the theoretical, phenomenological, experimental and cosmological constraints on such scenarios. We also discuss the collider signatures of such scenarios, how they may be distinguished from neutralino LSP scenarios, and how different flavours of sneutrino NLSP may be distinguished.
[ { "created": "Wed, 23 Jul 2008 19:51:59 GMT", "version": "v1" } ]
2009-01-06
[ [ "Ellis", "John", "" ], [ "Olive", "Keith A.", "" ], [ "Santoso", "Yudi", "" ] ]
We analyze scenarios in which some flavour of sneutrino is the next-to-lightest supersymmetric particle (NLSP), assuming that the gravitino is the lightest supersymmetric particle (LSP) and provides the cold dark matter. Such scenarios do not arise in the constrained supersymmetric extension of the Standard Model (CMSSM) with universal gaugino and scalar masses input at the GUT scale. However, models with non-universal Higgs masses (NUHM) do allow scenarios with a sneutrino NLSP, which are quite generic. We illustrate how such scenarios may arise, analyze the possible metastable sneutrino lifetime, and explore the theoretical, phenomenological, experimental and cosmological constraints on such scenarios. We also discuss the collider signatures of such scenarios, how they may be distinguished from neutralino LSP scenarios, and how different flavours of sneutrino NLSP may be distinguished.
hep-ph/0109282
Otmar Biebel
O. Biebel (MPI Munich), P. Nason (Uni Milan-Bicocca), B.R. Webber (Uni Cambridge)
Jet fragmentation in e^+e^- annihilation
27 pages, LaTeX2e, 12 .eps-files included, revised and corrected version, Fig. 9 and Tab.1 corrected and updated
null
null
Bicocca-FT-01-20, Cavendish-HEP-01/12, MPI-PhE/2001-14 (September 28, 2001, rev. November 9, 2001)
hep-ph
null
A short review of theoretical and experimental results on fragmentation in e^+e^- annihilation is presented. Starting with an introduction of the concept of fragmentation functions in e^+e^- annihilation, aspects of scaling violation, multiplicities, small and large x, longitudinal, gluon, light and heavy quark fragmentation are summarized.
[ { "created": "Fri, 28 Sep 2001 13:26:30 GMT", "version": "v1" }, { "created": "Fri, 9 Nov 2001 20:21:54 GMT", "version": "v2" } ]
2007-05-23
[ [ "Biebel", "O.", "", "MPI Munich" ], [ "Nason", "P.", "", "Uni Milan-Bicocca" ], [ "Webber", "B. R.", "", "Uni\n Cambridge" ] ]
A short review of theoretical and experimental results on fragmentation in e^+e^- annihilation is presented. Starting with an introduction of the concept of fragmentation functions in e^+e^- annihilation, aspects of scaling violation, multiplicities, small and large x, longitudinal, gluon, light and heavy quark fragmentation are summarized.
hep-ph/0312347
Toshitaka Tatsumi
Toshitaka Tatsumi, Tomoyuki Maruyama, Eiji Nakano
Ferromagnetism and Superconductivity in Quark Matter - Color magnetic superconductivity -
Proc. of Int. Workshop, "Finite Density QCD", 2003
Prog.Theor.Phys.Suppl.153:190-197,2004
10.1143/PTPS.153.190
null
hep-ph
null
A coexistent phase of spin polarization and color superconductivity in high-density QCD is studied at zero temperature. The axial-vector self-energy stemming from the Fock exchange term of the one-gluon-exchange interaction has a central role to cause spin polarization. As a significant feature, the Fermi surface is deformed by the axial-vector self-energy and then rotation symmetry is spontaneously broken down. The gap function results in being anisotropic in the momentum space in accordance with the deformation. It is found that spin polarization barely conflicts with color superconductivity, and almost coexists with it.
[ { "created": "Thu, 25 Dec 2003 11:24:37 GMT", "version": "v1" } ]
2008-11-26
[ [ "Tatsumi", "Toshitaka", "" ], [ "Maruyama", "Tomoyuki", "" ], [ "Nakano", "Eiji", "" ] ]
A coexistent phase of spin polarization and color superconductivity in high-density QCD is studied at zero temperature. The axial-vector self-energy stemming from the Fock exchange term of the one-gluon-exchange interaction has a central role to cause spin polarization. As a significant feature, the Fermi surface is deformed by the axial-vector self-energy and then rotation symmetry is spontaneously broken down. The gap function results in being anisotropic in the momentum space in accordance with the deformation. It is found that spin polarization barely conflicts with color superconductivity, and almost coexists with it.
1007.2919
Xavier Calmet
Xavier Calmet
Primordial Black Holes and a Large Hidden Sector
6 pages
Phys.Rev.D82:087501,2010
10.1103/PhysRevD.82.087501
null
hep-ph astro-ph.CO gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this note we point out that primordial black holes could be much shorter lived than usually assumed if there is a large hidden sector of particles that only interacts gravitationally with the particles of the standard model. The observation of the explosion of one of these black holes would severely constrain the energy scale at which gravity becomes strong.
[ { "created": "Sat, 17 Jul 2010 11:37:47 GMT", "version": "v1" }, { "created": "Mon, 1 Nov 2010 13:14:06 GMT", "version": "v2" } ]
2010-11-02
[ [ "Calmet", "Xavier", "" ] ]
In this note we point out that primordial black holes could be much shorter lived than usually assumed if there is a large hidden sector of particles that only interacts gravitationally with the particles of the standard model. The observation of the explosion of one of these black holes would severely constrain the energy scale at which gravity becomes strong.
1102.3997
Chiu Man Ho
Chiu Man Ho, Pham Q. Hung and Thomas W. Kephart
Conformal Completion of the Standard Model with a Fourth Generation
7 pages, v3: version to appear in JHEP
JHEP 1206 (2012) 045
10.1007/JHEP06(2012)045
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study dynamical electroweak symmetry breaking with a fourth generation within the $Z_n$ orbifolded $AdS_5\otimes S^5$ framework. A realistic $Z_7$ example is discussed. The initial theory reduces dynamically, due to the induced condensates, to a four-family trinification near a TeV-scale conformal fixed point where the gauge hierarchy problem does not exist. We predict new gauge bosons and bifundamental fermions and scalars accessible by the LHC.
[ { "created": "Sat, 19 Feb 2011 16:09:27 GMT", "version": "v1" }, { "created": "Fri, 13 Jan 2012 05:34:55 GMT", "version": "v2" }, { "created": "Sun, 27 May 2012 18:49:37 GMT", "version": "v3" } ]
2015-05-27
[ [ "Ho", "Chiu Man", "" ], [ "Hung", "Pham Q.", "" ], [ "Kephart", "Thomas W.", "" ] ]
We study dynamical electroweak symmetry breaking with a fourth generation within the $Z_n$ orbifolded $AdS_5\otimes S^5$ framework. A realistic $Z_7$ example is discussed. The initial theory reduces dynamically, due to the induced condensates, to a four-family trinification near a TeV-scale conformal fixed point where the gauge hierarchy problem does not exist. We predict new gauge bosons and bifundamental fermions and scalars accessible by the LHC.
hep-ph/0411055
Yili Wang
Tao Han, German Valencia and Yili Wang
New Signatures For Top In Hadron Collider
4 pages, 2 figures. Presented at the 2004 Meeting of the APS Division of Particles and Fields, University of California, Riverside, CA, Aug 26-31, 2004
Int.J.Mod.Phys. A20 (2005) 3214
10.1142/S0217751X05026182
null
hep-ph
null
We study the signatures for new TeV resonances that couple to top or bottom quarks both at the Tevatron Run II and at the LHC. We find that it is possible to study these resonances when they are produced in association with a pair of heavy quarks or in association with a single top at the LHC. In particular, with an integrated luminosity of 300 fb$^{-1}$ at the LHC, it is possible to probe resonance masses up to around 2 TeV.
[ { "created": "Wed, 3 Nov 2004 19:12:24 GMT", "version": "v1" } ]
2009-11-10
[ [ "Han", "Tao", "" ], [ "Valencia", "German", "" ], [ "Wang", "Yili", "" ] ]
We study the signatures for new TeV resonances that couple to top or bottom quarks both at the Tevatron Run II and at the LHC. We find that it is possible to study these resonances when they are produced in association with a pair of heavy quarks or in association with a single top at the LHC. In particular, with an integrated luminosity of 300 fb$^{-1}$ at the LHC, it is possible to probe resonance masses up to around 2 TeV.
1908.04659
Aleksander Filip Zarnecki
Aleksander Filip Zarnecki, Jan Kalinowski, Jan Klamka, Pawel Sopicki, Wojciech Kotlarski, Tania Robens and Dorota Sokolowska
Inert Doublet Model Signatures at Future e+e- Colliders
6 pages, 9 figures, submitted to proceedings of ALPS'2019
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Inert Doublet Model is one of the simplest extensions of the Standard Model, providing a dark matter candidate. It is a two Higgs doublet model with a discrete $Z_2$ symmetry, that prevents the scalars of the second doublet (inert scalars) from coupling to the Standard Model fermions and makes the lightest of them stable. We study a large number of Inert Doublet Model scenarios, which are consistent with current constraints on direct detection, including the most recent bounds from the XENON1T experiment and relic density of dark matter, as well as collider and low-energy limits. We use a set of benchmark points with different kinematic features, that promise detectable signals at future $e^+e^-$ colliders. Two inert scalar pair-production processes are considered, $e^+e^- \to A~H $ and $e^+e^- \to H^+H^-$, followed by decays of $H^\pm$ and $A$ into the final states which include the lightest and stable neutral scalar dark matter candidate $H$. Significance of the expected observations is studied for different benchmark models and different running scenarios, for centre-of-mass energies up to 3 TeV. Numerical results are presented for the signal signatures with two muons or an electron and a muon in the final state, while the qualitative conclusions can also be drawn for the semi-leptonic signatures.
[ { "created": "Tue, 13 Aug 2019 14:30:11 GMT", "version": "v1" } ]
2019-08-14
[ [ "Zarnecki", "Aleksander Filip", "" ], [ "Kalinowski", "Jan", "" ], [ "Klamka", "Jan", "" ], [ "Sopicki", "Pawel", "" ], [ "Kotlarski", "Wojciech", "" ], [ "Robens", "Tania", "" ], [ "Sokolowska", "Dorota", ...
The Inert Doublet Model is one of the simplest extensions of the Standard Model, providing a dark matter candidate. It is a two Higgs doublet model with a discrete $Z_2$ symmetry, that prevents the scalars of the second doublet (inert scalars) from coupling to the Standard Model fermions and makes the lightest of them stable. We study a large number of Inert Doublet Model scenarios, which are consistent with current constraints on direct detection, including the most recent bounds from the XENON1T experiment and relic density of dark matter, as well as collider and low-energy limits. We use a set of benchmark points with different kinematic features, that promise detectable signals at future $e^+e^-$ colliders. Two inert scalar pair-production processes are considered, $e^+e^- \to A~H $ and $e^+e^- \to H^+H^-$, followed by decays of $H^\pm$ and $A$ into the final states which include the lightest and stable neutral scalar dark matter candidate $H$. Significance of the expected observations is studied for different benchmark models and different running scenarios, for centre-of-mass energies up to 3 TeV. Numerical results are presented for the signal signatures with two muons or an electron and a muon in the final state, while the qualitative conclusions can also be drawn for the semi-leptonic signatures.
0709.2111
Marco Guzzi
Roberta Armillis, Claudio Coriano, Marco Guzzi
The Search for Extra Neutral Currents at the LHC: QCD and Anomalous Gauge Interactions
Talk given at QCD@work 2007, Martina Franca, Italy, 16-20 June 2007, 5 pages, 2 figures. To be published in the American Institute of Physics (AIP) conference proceedings
AIPConf.Proc.964:212-217,2007
10.1063/1.2823852
null
hep-ph
null
Extensions of the Standard Model with extra neutral currents due to additional anomalous abelian gauge factors are considered. We summarize the main features of the effective action associated to these theories. They are characterized by an axion-like particle (the {\em axi-higgs}) which can be (almost) massless, with its mass generated non-perturbatively in the QCD vacuum as for an ordinary Peccei-Quinn axion, but that can also mix with the scalars of the Higgs sector, becoming a heavy axion. We briefly describe the interplay between the electroweak and the QCD sectors in these types of theories, which emerge either from special vacua of string/brane theory; from partial decoupling of a heavier fermion sector or from an anomaly inflow in the context of models with extra dimensions.
[ { "created": "Thu, 13 Sep 2007 16:15:01 GMT", "version": "v1" }, { "created": "Fri, 14 Sep 2007 09:54:41 GMT", "version": "v2" } ]
2008-11-26
[ [ "Armillis", "Roberta", "" ], [ "Coriano", "Claudio", "" ], [ "Guzzi", "Marco", "" ] ]
Extensions of the Standard Model with extra neutral currents due to additional anomalous abelian gauge factors are considered. We summarize the main features of the effective action associated to these theories. They are characterized by an axion-like particle (the {\em axi-higgs}) which can be (almost) massless, with its mass generated non-perturbatively in the QCD vacuum as for an ordinary Peccei-Quinn axion, but that can also mix with the scalars of the Higgs sector, becoming a heavy axion. We briefly describe the interplay between the electroweak and the QCD sectors in these types of theories, which emerge either from special vacua of string/brane theory; from partial decoupling of a heavier fermion sector or from an anomaly inflow in the context of models with extra dimensions.
0711.0456
Georg Weiglein
S. Heinemeyer, W. Hollik, A.M. Weber and G. Weiglein
High-Precision Tests of the MSSM with GigaZ
6 pages, contribution to the proceedings of LCWS/ILC 2007
ECONF C0705302:TEV03,2007
null
IPPP/07/78, DCPT/07/156
hep-ph
null
We review the physics potential of the GigaZ option of the International Linear Collider (ILC) for probing the Minimal Supersymmetric Standard Model (MSSM) via the sensitivity of the electroweak precision observables measured at the ILC to quantum corrections. A particular focus is put on the effective leptonic weak mixing angle, sin^2_theta_eff. The MSSM predictions take into account the complete one-loop results including the full complex phase dependence, all available MSSM two-loop corrections as well as the full Standard Model (SM) results. We find that the anticipated experimental accuracy at the ILC with GigaZ option may resolve the virtual effects of SUSY particles even in scenarios where the SUSY particles are so heavy that they escape direct detection at the LHC and the first phase of the ILC.
[ { "created": "Sat, 3 Nov 2007 14:26:39 GMT", "version": "v1" } ]
2009-02-16
[ [ "Heinemeyer", "S.", "" ], [ "Hollik", "W.", "" ], [ "Weber", "A. M.", "" ], [ "Weiglein", "G.", "" ] ]
We review the physics potential of the GigaZ option of the International Linear Collider (ILC) for probing the Minimal Supersymmetric Standard Model (MSSM) via the sensitivity of the electroweak precision observables measured at the ILC to quantum corrections. A particular focus is put on the effective leptonic weak mixing angle, sin^2_theta_eff. The MSSM predictions take into account the complete one-loop results including the full complex phase dependence, all available MSSM two-loop corrections as well as the full Standard Model (SM) results. We find that the anticipated experimental accuracy at the ILC with GigaZ option may resolve the virtual effects of SUSY particles even in scenarios where the SUSY particles are so heavy that they escape direct detection at the LHC and the first phase of the ILC.
hep-ph/0611139
Alexander Bakulev P.
A. P. Bakulev
Pion distribution amplitude and form-factors: Improved Gaussian model of QCD vacuum
10 pages, 8 figures, invited talk at the International Conference on New Trends in High-Energy Physics, Yalta, Crimea, Ukraine, September 16--23, 2006
null
null
null
hep-ph
null
We describe the present status of the pion distribution amplitude (DA) as it originated from several sources: (i) a nonperturbative approach, based on QCD sum rules with nonlocal condensates, (ii) an O(\alpha_s) QCD analysis of the CLEO data on F^{\gamma\gamma^*\pi}(Q^2) with asymptotic and renormalon models for higher twists, and (iii) recent high-precision lattice QCD calculations of the second moment of the pion DA. Then we show the comparison of the results for the pion electromagnetic form factor, obtained in analytic perturbation theory, with JLab data on F_{\pi}(Q^2). After that we introduce the improved model for nonlocal condensates in QCD and show its consequences for the pion DA and \gamma\gamma^*\to\pi transition form factor. In order to facilitate possible applications of BMS and improved ``bunches'' we suggest approximate analytic descriptions of their boundaries.
[ { "created": "Fri, 10 Nov 2006 10:35:00 GMT", "version": "v1" } ]
2007-05-23
[ [ "Bakulev", "A. P.", "" ] ]
We describe the present status of the pion distribution amplitude (DA) as it originated from several sources: (i) a nonperturbative approach, based on QCD sum rules with nonlocal condensates, (ii) an O(\alpha_s) QCD analysis of the CLEO data on F^{\gamma\gamma^*\pi}(Q^2) with asymptotic and renormalon models for higher twists, and (iii) recent high-precision lattice QCD calculations of the second moment of the pion DA. Then we show the comparison of the results for the pion electromagnetic form factor, obtained in analytic perturbation theory, with JLab data on F_{\pi}(Q^2). After that we introduce the improved model for nonlocal condensates in QCD and show its consequences for the pion DA and \gamma\gamma^*\to\pi transition form factor. In order to facilitate possible applications of BMS and improved ``bunches'' we suggest approximate analytic descriptions of their boundaries.
0812.3900
Zohar Komargodski
Zohar Komargodski and Nathan Seiberg
mu and General Gauge Mediation
21 pages. v2: minor corrections. v3: added reference
JHEP 0903:072,2009
10.1088/1126-6708/2009/03/072
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We address the mu-problem in the context of General Gauge Mediation (GGM). We classify possible models depending on the way the Higgs fields couple to the supersymmetry breaking hidden-sector. The different types of models have distinct signatures in the MSSM parameters. We find concrete and surprisingly simple examples based on messengers in each class. These examples lead to all the soft masses and a consistent Higgs-sector.
[ { "created": "Sun, 21 Dec 2008 04:31:09 GMT", "version": "v1" }, { "created": "Thu, 29 Jan 2009 21:18:25 GMT", "version": "v2" }, { "created": "Sat, 14 Feb 2009 17:13:32 GMT", "version": "v3" } ]
2010-04-15
[ [ "Komargodski", "Zohar", "" ], [ "Seiberg", "Nathan", "" ] ]
We address the mu-problem in the context of General Gauge Mediation (GGM). We classify possible models depending on the way the Higgs fields couple to the supersymmetry breaking hidden-sector. The different types of models have distinct signatures in the MSSM parameters. We find concrete and surprisingly simple examples based on messengers in each class. These examples lead to all the soft masses and a consistent Higgs-sector.
hep-ph/9605226
Ariel Zhitnitsky
Ariel Zhitnitsky
Constituent Quark Model versus Nonperturbative QCD
13 pages, latex, no figures. Talk given at the Workshop ``Continuous Advances in QCD,96''. Theoretical Physics Institute, University of Minnesota, Minneapolis, MN, March 28-31, 1996
null
null
null
hep-ph
null
We discuss a few, apparently different (but actually, tightly related) problems: 1. The relation between QCD and valence quark model, 2. The asymptotic behavior of the nonperturbative pion wave function $\psi(\k, x)$ at $x\rightarrow 0,~1, \k \rightarrow \infty$ and 3. The dimensional counting rules in the intermediate region of energy. The analysis is based on such general methods as dispersion relations, duality and PCAC. We calculate the asymptotic behavior of the wave function ($wf$) at the end-point region ($x\rightarrow 1$ and $\k\rightarrow\infty$) by analysing the corresponding large $n-$th moments in transverse $\la\vec{k}_{\perp}^{2n}\ra \sim n!$ and longitudinal $\la (2x-1)^n\ra \sim 1/n^2$ directions. This information fixes the asymptotic behavior of $wf$ at large $\k$ ( which is turned out to be Gaussian commonly used in the phenomenological analyses). We discuss some applications of the obtained results. In particular, we calculate the nonleading ``soft" contribution to the pion form factor at intermediate momentum transfer. We argue, that due to the specific properties of $\psi(\k, x)$, the corresponding contribution can temporarily {\bf simulate} the leading twist behavior in the extent region of $ Q^2 $. The same effect also takes place for the nucleon formfactor. Such a mechanism, if it is correct, would be an explanation of the phenomenological success of the dimensional counting rules at available, very modest energies for many different processes. We discuss some inclusive amplitudes also.
[ { "created": "Sun, 5 May 1996 21:39:46 GMT", "version": "v1" } ]
2007-05-23
[ [ "Zhitnitsky", "Ariel", "" ] ]
We discuss a few, apparently different (but actually, tightly related) problems: 1. The relation between QCD and valence quark model, 2. The asymptotic behavior of the nonperturbative pion wave function $\psi(\k, x)$ at $x\rightarrow 0,~1, \k \rightarrow \infty$ and 3. The dimensional counting rules in the intermediate region of energy. The analysis is based on such general methods as dispersion relations, duality and PCAC. We calculate the asymptotic behavior of the wave function ($wf$) at the end-point region ($x\rightarrow 1$ and $\k\rightarrow\infty$) by analysing the corresponding large $n-$th moments in transverse $\la\vec{k}_{\perp}^{2n}\ra \sim n!$ and longitudinal $\la (2x-1)^n\ra \sim 1/n^2$ directions. This information fixes the asymptotic behavior of $wf$ at large $\k$ ( which is turned out to be Gaussian commonly used in the phenomenological analyses). We discuss some applications of the obtained results. In particular, we calculate the nonleading ``soft" contribution to the pion form factor at intermediate momentum transfer. We argue, that due to the specific properties of $\psi(\k, x)$, the corresponding contribution can temporarily {\bf simulate} the leading twist behavior in the extent region of $ Q^2 $. The same effect also takes place for the nucleon formfactor. Such a mechanism, if it is correct, would be an explanation of the phenomenological success of the dimensional counting rules at available, very modest energies for many different processes. We discuss some inclusive amplitudes also.
1406.7700
Scientific Information Service CERN
Emi Kou (Orsay, LAL)
Flavour physics and CP violation (CERN-2014-001)
26 pages, contribution to the 1st Asia-Europe-Pacific School of High-Energy Physics, Fukuoka, Japan, 14 - 27 Oct 2012
CERN Yellow Report CERN-2014-001, pp.151-176
10.5170/CERN-2014-001.151
null
hep-ph
http://creativecommons.org/licenses/by/3.0/
In these three lectures, I overview the theoretical framework of the flavour physics and CP violation. The first lecture is the introduction to the flavour physics. Namely, I give theoretical basics of the weak interaction. I follow also some historical aspect, discovery of the CP violation, phenomenological studies of charged and neutral currents and the success of the GIM mechanism. In the second lecture, I describe the flavour physics and CP violating phenomena in the Standard Model (SM). I also give the latest experimental observation of the CP Violation at the B factories and the LHC and discuss its interpretation. In the third lecture, I discuss the on-going search of the signals beyond SM in the flavour physics and also the future prospects.
[ { "created": "Mon, 30 Jun 2014 12:38:22 GMT", "version": "v1" } ]
2014-07-01
[ [ "Kou", "Emi", "", "Orsay, LAL" ] ]
In these three lectures, I overview the theoretical framework of the flavour physics and CP violation. The first lecture is the introduction to the flavour physics. Namely, I give theoretical basics of the weak interaction. I follow also some historical aspect, discovery of the CP violation, phenomenological studies of charged and neutral currents and the success of the GIM mechanism. In the second lecture, I describe the flavour physics and CP violating phenomena in the Standard Model (SM). I also give the latest experimental observation of the CP Violation at the B factories and the LHC and discuss its interpretation. In the third lecture, I discuss the on-going search of the signals beyond SM in the flavour physics and also the future prospects.
1702.07479
Mikko Laine
M. Laine, M. Meyer, G. Nardini
Thermal phase transition with full 2-loop effective potential
42 pages. v3: many clarifications added, published version
Nucl. Phys. B 920 (2017) 565-600
10.1016/j.nuclphysb.2017.04.023
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Theories with extended Higgs sectors constructed in view of cosmological ramifications (gravitational wave signal, baryogenesis, dark matter) are often faced with conflicting requirements for their couplings; in particular those influencing the strength of a phase transition may be large. Large couplings compromise perturbative studies, as well as the high-temperature expansion that is invoked in dimensionally reduced lattice investigations. With the example of the inert doublet extension of the Standard Model (IDM), we show how a resummed 2-loop effective potential can be computed without a high-T expansion, and use the result to scrutinize its accuracy. With the exception of Tc, which is sensitive to contributions from heavy modes, the high-T expansion is found to perform well. 2-loop corrections weaken the transition in IDM, but they are moderate, whereby a strong transition remains an option.
[ { "created": "Fri, 24 Feb 2017 07:16:16 GMT", "version": "v1" }, { "created": "Wed, 1 Mar 2017 09:46:12 GMT", "version": "v2" }, { "created": "Fri, 19 May 2017 08:57:09 GMT", "version": "v3" } ]
2017-05-22
[ [ "Laine", "M.", "" ], [ "Meyer", "M.", "" ], [ "Nardini", "G.", "" ] ]
Theories with extended Higgs sectors constructed in view of cosmological ramifications (gravitational wave signal, baryogenesis, dark matter) are often faced with conflicting requirements for their couplings; in particular those influencing the strength of a phase transition may be large. Large couplings compromise perturbative studies, as well as the high-temperature expansion that is invoked in dimensionally reduced lattice investigations. With the example of the inert doublet extension of the Standard Model (IDM), we show how a resummed 2-loop effective potential can be computed without a high-T expansion, and use the result to scrutinize its accuracy. With the exception of Tc, which is sensitive to contributions from heavy modes, the high-T expansion is found to perform well. 2-loop corrections weaken the transition in IDM, but they are moderate, whereby a strong transition remains an option.
1910.11418
Jack Y. Araz
Jack Y. Araz, Mariana Frank and Benjamin Fuks
Reinterpreting the results of the LHC with MadAnalysis 5: uncertainties and higher-luminosity estimates
19 pages, 15 figures, The European Physical Journal C approved version
Eur. Phys. J. C 80 (2020) 531
10.1140/epjc/s10052-020-8076-6
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The MadAnalysis 5 framework can be used to assess the potential of various LHC analyses for unravelling any specific new physics signal. We present an extension of the LHC reinterpretation capabilities of the programme allowing for the inclusion of theoretical and systematical uncertainties on the signal in the reinterpretation procedure. We have implemented extra methods dedicated to the extrapolation of the impact of a given analysis to higher luminosities, including various options for the treatment of the errors. As an application, we study three classes of new physics models. We first focus on a simplified model in which the Standard Model is supplemented by a gluino and a neutralino. We show that uncertainties could in particular degrade the bounds by several hundreds of GeV when considering 3000 fb$^{-1}$ of future LHC data. We next investigate another supersymmetry-inspired simplified model, in which the Standard Model is extended by a first generation squark species and a neutralino. We reach similar conclusions. Finally, we study a class of s-channel dark matter setups and compare the expectation for two types of scenarios differing in the details of the implementation of the mediation between the dark and Standard Model sectors.
[ { "created": "Thu, 24 Oct 2019 20:53:12 GMT", "version": "v1" }, { "created": "Wed, 3 Jun 2020 14:26:04 GMT", "version": "v2" } ]
2020-06-17
[ [ "Araz", "Jack Y.", "" ], [ "Frank", "Mariana", "" ], [ "Fuks", "Benjamin", "" ] ]
The MadAnalysis 5 framework can be used to assess the potential of various LHC analyses for unravelling any specific new physics signal. We present an extension of the LHC reinterpretation capabilities of the programme allowing for the inclusion of theoretical and systematical uncertainties on the signal in the reinterpretation procedure. We have implemented extra methods dedicated to the extrapolation of the impact of a given analysis to higher luminosities, including various options for the treatment of the errors. As an application, we study three classes of new physics models. We first focus on a simplified model in which the Standard Model is supplemented by a gluino and a neutralino. We show that uncertainties could in particular degrade the bounds by several hundreds of GeV when considering 3000 fb$^{-1}$ of future LHC data. We next investigate another supersymmetry-inspired simplified model, in which the Standard Model is extended by a first generation squark species and a neutralino. We reach similar conclusions. Finally, we study a class of s-channel dark matter setups and compare the expectation for two types of scenarios differing in the details of the implementation of the mediation between the dark and Standard Model sectors.
1708.04384
Li-Ye Xiao
Li-Ye Xiao, Kai-Lei Wang, Qi-Fang L\"u, Xian-Hui Zhong, and Shi-Lin Zhu
Strong and radiative decays of the doubly charmed baryons
10 pages, 7 figures
Phys. Rev. D 96, 094005 (2017)
10.1103/PhysRevD.96.094005
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We have systematically studied the strong and radiative decays of the low-lying $1P$-wave doubly charmed baryons. Some interesting observations are: (i) The states $\Xi_{cc}^*$ and $\Omega_{cc}^*$ with $J^P=3/2^+$ have a fairly large decay rate into the $\Xi_{cc}\gamma$ and $\Omega_{cc}\gamma$ channels with a width $\sim 15$ and $\sim7$ keV, respectively. (ii) The lowest lying excited doubly charmed baryons are dominated by the $1P$ $\rho$ mode excitations, which should be quite narrow states. They decay into the ground state with $J^P=1/2^+$ through the radiative transitions with a significant ratio. (iii) The total decay widths of the first orbital excitations of $\lambda$ mode ($1P_{\lambda}$ states with $J^P=1/2^-$, $3/2^-$, $5/2^-$) are about $\Gamma\sim100$ MeV, and the ratio between the radiative and hadronic decay widths is about $\mathcal{O}(10^{-3})$.
[ { "created": "Tue, 15 Aug 2017 02:36:05 GMT", "version": "v1" }, { "created": "Sat, 26 Aug 2017 02:21:16 GMT", "version": "v2" } ]
2017-11-22
[ [ "Xiao", "Li-Ye", "" ], [ "Wang", "Kai-Lei", "" ], [ "Lü", "Qi-Fang", "" ], [ "Zhong", "Xian-Hui", "" ], [ "Zhu", "Shi-Lin", "" ] ]
We have systematically studied the strong and radiative decays of the low-lying $1P$-wave doubly charmed baryons. Some interesting observations are: (i) The states $\Xi_{cc}^*$ and $\Omega_{cc}^*$ with $J^P=3/2^+$ have a fairly large decay rate into the $\Xi_{cc}\gamma$ and $\Omega_{cc}\gamma$ channels with a width $\sim 15$ and $\sim7$ keV, respectively. (ii) The lowest lying excited doubly charmed baryons are dominated by the $1P$ $\rho$ mode excitations, which should be quite narrow states. They decay into the ground state with $J^P=1/2^+$ through the radiative transitions with a significant ratio. (iii) The total decay widths of the first orbital excitations of $\lambda$ mode ($1P_{\lambda}$ states with $J^P=1/2^-$, $3/2^-$, $5/2^-$) are about $\Gamma\sim100$ MeV, and the ratio between the radiative and hadronic decay widths is about $\mathcal{O}(10^{-3})$.
1109.3396
Gianluca Blankenburg
Gianluca Blankenburg, Stefano Morisi
Fermion masses and mixing with tri-bimaximal in SO(10) with type-I seesaw
13 pages, journal version, minor comments and reference added
JHEP 1201: 016,2012
10.1007/JHEP01(2012)016
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study a class of models for tri-bimaximal neutrino mixing in SO(10) grand unified SUSY framework. Neutrino masses arise from both type-I and type-II seesaw mechanisms. We use dimension five operators in order to not spoil tri-bimaximal mixing by means of type-I contribution in the neutrino sector. We show that it is possible to fit all fermion masses and mixings including also the recent T2K result as deviation from the tri-bimaximal.
[ { "created": "Thu, 15 Sep 2011 16:04:27 GMT", "version": "v1" }, { "created": "Tue, 27 Sep 2011 06:56:57 GMT", "version": "v2" }, { "created": "Tue, 17 Jan 2012 09:16:44 GMT", "version": "v3" } ]
2015-05-30
[ [ "Blankenburg", "Gianluca", "" ], [ "Morisi", "Stefano", "" ] ]
We study a class of models for tri-bimaximal neutrino mixing in SO(10) grand unified SUSY framework. Neutrino masses arise from both type-I and type-II seesaw mechanisms. We use dimension five operators in order to not spoil tri-bimaximal mixing by means of type-I contribution in the neutrino sector. We show that it is possible to fit all fermion masses and mixings including also the recent T2K result as deviation from the tri-bimaximal.
hep-ph/9904325
Muneyuki Ishida
Rukmani Mohanta, Anjan K. Giri, Mohinder P. Khanna (Panjab University), Muneyuki Ishida(TIT) and Shin Ishida(Nihon University)
Exclusive Weak Radiative Decays of B Mesons in the Covariant Oscillator Quark Model
9 pages, uses ptptex.sty
Prog.Theor.Phys.101:1083-1091,1999
10.1143/PTP.101.1083
NUP-A-99-6
hep-ph
null
Exclusive weak radiative B meson decays are studied using the covariant oscillator quark model. The branching ratios for the processes B0 to K*0 gamma and B to K* gamma have been estimated. These are in reasonable agreement with the available experimental data. The calculation has been extended to the CKM-suppressed decay processes B- to rho- gamma and Bs to K*0 gamma .
[ { "created": "Wed, 14 Apr 1999 03:44:48 GMT", "version": "v1" } ]
2014-11-17
[ [ "Mohanta", "Rukmani", "", "Panjab\n University" ], [ "Giri", "Anjan K.", "", "Panjab\n University" ], [ "Khanna", "Mohinder P.", "", "Panjab\n University" ], [ "Ishida", "Muneyuki", "", "TIT" ], [ "Ishida", "Shin", "", ...
Exclusive weak radiative B meson decays are studied using the covariant oscillator quark model. The branching ratios for the processes B0 to K*0 gamma and B to K* gamma have been estimated. These are in reasonable agreement with the available experimental data. The calculation has been extended to the CKM-suppressed decay processes B- to rho- gamma and Bs to K*0 gamma .
hep-ph/0001088
Peter Soldan
T. Hambye (Frascati), G.O. Koehler, E.A. Paschos, P.H. Soldan (Dortmund U.)
Analyzing epsilon'/epsilon in the 1/N_c Expansion
One reference corrected. 5 pages, talk presented by P.H. Soldan at the 3. International Conference on B Physics and CP Violation, Taipei, Taiwan, December 3 - 7, 1999. Slightly expanded version of the article submitted to the proceedings
null
10.1142/9789812791870_0052
DO--TH 00/01, LNF-00/001 (P)
hep-ph
null
We present a recent analysis of epsilon'/epsilon in the 1/N_c expansion. We show that the 1/N_c corrections to the matrix element of Q_6 are large and positive, indicating a Delta I=1/2 enhancement similar to the one of Q_1 and Q_2 which dominate the CP conserving amplitude. This enhances the CP ratio and can bring the standard model prediction close to the measured value for central values of the parameters.
[ { "created": "Tue, 11 Jan 2000 16:44:37 GMT", "version": "v1" }, { "created": "Fri, 21 Jan 2000 15:12:29 GMT", "version": "v2" } ]
2016-11-23
[ [ "Hambye", "T.", "", "Frascati" ], [ "Koehler", "G. O.", "", "Dortmund U." ], [ "Paschos", "E. A.", "", "Dortmund U." ], [ "Soldan", "P. H.", "", "Dortmund U." ] ]
We present a recent analysis of epsilon'/epsilon in the 1/N_c expansion. We show that the 1/N_c corrections to the matrix element of Q_6 are large and positive, indicating a Delta I=1/2 enhancement similar to the one of Q_1 and Q_2 which dominate the CP conserving amplitude. This enhances the CP ratio and can bring the standard model prediction close to the measured value for central values of the parameters.
0912.3715
Stefan H\"oche
Tancredi Carli, Thomas Gehrmann, Stefan H\"oche
Hadronic final states in deep-inelastic scattering with Sherpa
32 pages, 22 figures
Eur.Phys.J.C67:73-97,2010
10.1140/epjc/s10052-010-1261-2
ZU-TH 20/09, MCNET/09/19
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We extend the multi-purpose Monte-Carlo event generator Sherpa to include processes in deeply inelastic lepton-nucleon scattering. Hadronic final states in this kinematical setting are characterised by the presence of multiple kinematical scales, which were up to now accounted for only by specific resummations in individual kinematical regions. Using an extension of the recently introduced method for merging truncated parton showers with higher-order tree-level matrix elements, it is possible to obtain predictions which are reliable in all kinematical limits. Different hadronic final states, defined by jets or individual hadrons, in deep-inelastic scattering are analysed and the corresponding results are compared to HERA data. The various sources of theoretical uncertainties of the approach are discussed and quantified. The extension to deeply inelastic processes provides the opportunity to validate the merging of matrix elements and parton showers in multi-scale kinematics inaccessible in other collider environments. It also allows to use HERA data on hadronic final states in the tuning of hadronisation models.
[ { "created": "Fri, 18 Dec 2009 16:02:37 GMT", "version": "v1" } ]
2015-09-22
[ [ "Carli", "Tancredi", "" ], [ "Gehrmann", "Thomas", "" ], [ "Höche", "Stefan", "" ] ]
We extend the multi-purpose Monte-Carlo event generator Sherpa to include processes in deeply inelastic lepton-nucleon scattering. Hadronic final states in this kinematical setting are characterised by the presence of multiple kinematical scales, which were up to now accounted for only by specific resummations in individual kinematical regions. Using an extension of the recently introduced method for merging truncated parton showers with higher-order tree-level matrix elements, it is possible to obtain predictions which are reliable in all kinematical limits. Different hadronic final states, defined by jets or individual hadrons, in deep-inelastic scattering are analysed and the corresponding results are compared to HERA data. The various sources of theoretical uncertainties of the approach are discussed and quantified. The extension to deeply inelastic processes provides the opportunity to validate the merging of matrix elements and parton showers in multi-scale kinematics inaccessible in other collider environments. It also allows to use HERA data on hadronic final states in the tuning of hadronisation models.
2307.09987
Wenyang Qian
Wenyang Qian
Quantum simulation of jet evolution in a medium
6 pages, 4 figures, Proceeding on 11th International Conference on Hard and Electromagnetic Probes of High Energy Nuclear Collisions (Hard Probe 2023), 26-31 March 2023, Aschaffenburg, Germany. This proceeding is based on our recent work, arXiv:2307.01792
null
null
null
hep-ph quant-ph
http://creativecommons.org/licenses/by-nc-nd/4.0/
Jets provide one of the primary probes of the quark-gluon plasma produced in ultrarelativistic heavy ion collisions and the cold nuclear matter explored in deep inelastic scattering experiments. However, despite important developments in the last years, a description of the real-time evolution of QCD jets inside a medium is still far from complete. In our previous work, we have explored quantum technologies as a promising alternative theoretical laboratory to simulate jet evolution in QCD matter, to overcome inherent technical difficulties in present calculations. Here, we extend our previous investigation from the single particle to the multiple particle Fock spaces, taking into account gluon production. Based on the light-front Hamiltonian formalism, we construct a digital quantum circuit that tracks the evolution of a multi-particle jet probe in the presence of a stochastic color background. Using the quantum simulation algorithm, we show the medium-induced modification to the jet evolution in both the momentum broadening and gluon production.
[ { "created": "Wed, 19 Jul 2023 13:45:59 GMT", "version": "v1" } ]
2023-07-24
[ [ "Qian", "Wenyang", "" ] ]
Jets provide one of the primary probes of the quark-gluon plasma produced in ultrarelativistic heavy ion collisions and the cold nuclear matter explored in deep inelastic scattering experiments. However, despite important developments in the last years, a description of the real-time evolution of QCD jets inside a medium is still far from complete. In our previous work, we have explored quantum technologies as a promising alternative theoretical laboratory to simulate jet evolution in QCD matter, to overcome inherent technical difficulties in present calculations. Here, we extend our previous investigation from the single particle to the multiple particle Fock spaces, taking into account gluon production. Based on the light-front Hamiltonian formalism, we construct a digital quantum circuit that tracks the evolution of a multi-particle jet probe in the presence of a stochastic color background. Using the quantum simulation algorithm, we show the medium-induced modification to the jet evolution in both the momentum broadening and gluon production.
2210.13402
Yi Chung
Yi Chung
Explaining the $R_{K^{(*)}}$ anomalies and the CDF $M_W$ in Flavorful Top Seesaw Models with Gauged $U(1)_{L(-R)}$
27 pages, 4 figures; v2: some typos corrected and comments added; v3: some equations corrected and comments on new LHCb measurements added
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
A new heavy $Z'$ vector boson provides a possible explanation for the neutral current B anomalies and points to the scale where we expect the solution to the hierarchy problem to appear. In this paper, we explore a modified Top Seesaw model based on the global symmetry breaking of $U(3)_L$ to $U(2)_L$. The symmetry is partially gauged such that the breaking introduces not only a composite Higgs doublet but also a TeV-scale $Z'$ boson. The $U(3)_L/U(2)_L$ Top Seesaw model predicts a light Higgs boson as well as a large top Yukawa coupling. Additional $U(1)'$ symmetry is gauged such that a flavorful TeV-scale $Z'$ boson is introduced to address the B anomalies. The existence of a heavy vector-like top quark and $Z-Z'$ mixing breaks the custodial symmetry, which predicts a heavier $W$ mass as observed by the CDF collaboration. Two possible candidates for the $U(1)'$ symmetry corresponding to the $Z'$ boson, $U(1)_L$ and $U(1)_{L-R}$, are discussed in detail. The parameter space for the models to address both anomalies is presented. The direct searches of the $Z'$ boson from dilepton channels are also studied. Based on the assumptions, a TeV-scale $Z'$ boson is still viable and can be probed in the near future.
[ { "created": "Mon, 24 Oct 2022 16:57:08 GMT", "version": "v1" }, { "created": "Mon, 31 Oct 2022 19:18:04 GMT", "version": "v2" }, { "created": "Thu, 9 Mar 2023 21:25:50 GMT", "version": "v3" } ]
2023-03-13
[ [ "Chung", "Yi", "" ] ]
A new heavy $Z'$ vector boson provides a possible explanation for the neutral current B anomalies and points to the scale where we expect the solution to the hierarchy problem to appear. In this paper, we explore a modified Top Seesaw model based on the global symmetry breaking of $U(3)_L$ to $U(2)_L$. The symmetry is partially gauged such that the breaking introduces not only a composite Higgs doublet but also a TeV-scale $Z'$ boson. The $U(3)_L/U(2)_L$ Top Seesaw model predicts a light Higgs boson as well as a large top Yukawa coupling. Additional $U(1)'$ symmetry is gauged such that a flavorful TeV-scale $Z'$ boson is introduced to address the B anomalies. The existence of a heavy vector-like top quark and $Z-Z'$ mixing breaks the custodial symmetry, which predicts a heavier $W$ mass as observed by the CDF collaboration. Two possible candidates for the $U(1)'$ symmetry corresponding to the $Z'$ boson, $U(1)_L$ and $U(1)_{L-R}$, are discussed in detail. The parameter space for the models to address both anomalies is presented. The direct searches of the $Z'$ boson from dilepton channels are also studied. Based on the assumptions, a TeV-scale $Z'$ boson is still viable and can be probed in the near future.
1512.05364
Domenico Bonocore
Domenico Bonocore
Universal structure of the Drell-Yan process beyond threshold
10 pages, Proceedings of the 12th International Symposium on Radiative Corrections (Radcor 2015) and LoopFest XIV (Radiative Corrections for the LHC and Future Colliders)
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review recent results in the investigation of threshold logarithms at next-to-leading power considering the case of the Drell-Yan cross section at NNLO. We first show how they can be reproduced with a method of region calculation. Then we move to an approach based on soft- collinear factorization, showing that the entire logarithmic structure can be reproduced by means of universal functions.
[ { "created": "Wed, 16 Dec 2015 21:00:16 GMT", "version": "v1" } ]
2015-12-18
[ [ "Bonocore", "Domenico", "" ] ]
We review recent results in the investigation of threshold logarithms at next-to-leading power considering the case of the Drell-Yan cross section at NNLO. We first show how they can be reproduced with a method of region calculation. Then we move to an approach based on soft- collinear factorization, showing that the entire logarithmic structure can be reproduced by means of universal functions.
2312.13278
Manuel Ettengruber
Gia Dvali, Manuel Ettengruber, Anja Stuhlfauth
Kaluza-Klein Spectroscopy from Neutron Oscillations into Hidden Dimensions
16 pages
null
null
null
hep-ph gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
Neutrons and neutrinos are natural probes for new physics. Since they carry no conserved gauge quantum numbers, both can easily mix with the fermions from hidden sectors. A particularly interesting effect is the oscillation of a neutron or a neutrino into a fermion propagating in large extra dimensions. In fact, such a mixing has been identified as the possible origin of small neutrino mass. In this paper, we study neutron oscillations into an extra-dimensional fermion and show that this effect provides a resonance imaging of the Kaluza-Klein tower. The remarkable feature of this phenomenon is its generic nature: because of a fine spacing of the Kaluza-Klein tower, neutrons at a variety of energy levels, both free or within nuclei, find a bulk oscillation partner. In particular, the partner can be a Kaluza-Klein mode of the same species that gives mass to the neutrino. The existence of bulk states matching the neutron energy levels of nuclear spectra gives rise to tight constraints as well as to potentially observable effects. For a free neutron, we predict recurrent resonant oscillations occurring with the values of the magnetic field correlated with the KK levels. We derive bounds on extra dimensions from ultra-cold neutron experiments and suggest signatures for refined measurements, which, in particular, can probe the parameter space motivated by the Hierarchy Problem. Ultra-cold neutron experiments offer a unique way of Kaluza-Klein spectroscopy.
[ { "created": "Wed, 20 Dec 2023 18:57:06 GMT", "version": "v1" } ]
2023-12-21
[ [ "Dvali", "Gia", "" ], [ "Ettengruber", "Manuel", "" ], [ "Stuhlfauth", "Anja", "" ] ]
Neutrons and neutrinos are natural probes for new physics. Since they carry no conserved gauge quantum numbers, both can easily mix with the fermions from hidden sectors. A particularly interesting effect is the oscillation of a neutron or a neutrino into a fermion propagating in large extra dimensions. In fact, such a mixing has been identified as the possible origin of small neutrino mass. In this paper, we study neutron oscillations into an extra-dimensional fermion and show that this effect provides a resonance imaging of the Kaluza-Klein tower. The remarkable feature of this phenomenon is its generic nature: because of a fine spacing of the Kaluza-Klein tower, neutrons at a variety of energy levels, both free or within nuclei, find a bulk oscillation partner. In particular, the partner can be a Kaluza-Klein mode of the same species that gives mass to the neutrino. The existence of bulk states matching the neutron energy levels of nuclear spectra gives rise to tight constraints as well as to potentially observable effects. For a free neutron, we predict recurrent resonant oscillations occurring with the values of the magnetic field correlated with the KK levels. We derive bounds on extra dimensions from ultra-cold neutron experiments and suggest signatures for refined measurements, which, in particular, can probe the parameter space motivated by the Hierarchy Problem. Ultra-cold neutron experiments offer a unique way of Kaluza-Klein spectroscopy.
hep-ph/9910265
Yu-Ping Kuang
Ling Zhang, Xue-Lei Wang, Yu-Ping Kuang, Hong-Yi Zhou
Pseudo-Goldstone Boson Effects in Top-Antitop Productions at High Energy Hadron Colliders and Testing Technicolor Models
10 pages in RevTex and 4 PS-files for the figures. Paramemter range is changed, and some references are added. Version for publication in Phys. Rev. D
Phys.Rev. D61 (2000) 115007
10.1103/PhysRevD.61.115007
TU-HEP-TH-99/103
hep-ph
null
We study the top quark pair production process p+p(anti-p)-->top+antitop in various kinds of technicolor (TC) models at the Fermilab Tevatron Run II and the CERN LHC. The s-channel neutral pseudo-Goldstone bosons (PGB's) contribute dominately to the production amplitudes from its coupling to the gluons through the triangle loops of techniquarks and the top quark. Cross sections in different TC models with s-channel PGB contributions are calculated. It is shown that the PGB effects can be experimentally tested and different TC models under consideration can be distinguished at the LHC. Therefore, the p+p-->top+antitop process at the LHC provides feasible tests of the TC models.
[ { "created": "Thu, 7 Oct 1999 12:29:35 GMT", "version": "v1" }, { "created": "Sat, 9 Oct 1999 07:58:45 GMT", "version": "v2" }, { "created": "Sun, 20 Feb 2000 10:51:38 GMT", "version": "v3" } ]
2009-10-31
[ [ "Zhang", "Ling", "" ], [ "Wang", "Xue-Lei", "" ], [ "Kuang", "Yu-Ping", "" ], [ "Zhou", "Hong-Yi", "" ] ]
We study the top quark pair production process p+p(anti-p)-->top+antitop in various kinds of technicolor (TC) models at the Fermilab Tevatron Run II and the CERN LHC. The s-channel neutral pseudo-Goldstone bosons (PGB's) contribute dominately to the production amplitudes from its coupling to the gluons through the triangle loops of techniquarks and the top quark. Cross sections in different TC models with s-channel PGB contributions are calculated. It is shown that the PGB effects can be experimentally tested and different TC models under consideration can be distinguished at the LHC. Therefore, the p+p-->top+antitop process at the LHC provides feasible tests of the TC models.
1611.08591
Fabien Besnard
Fabien Besnard
A remark on the mathematics of the seesaw mechanism
null
null
null
null
hep-ph hep-th math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
To demonstrate that matrices of seesaw type lead to a hieararchy in the neutrino masses, i.e. that there is a large gap in the singular spectrum of these matrices, one generally uses an approximate block-diagonalization procedure. In this note we show that no approximation is required to prove this gap property if the Courant-Fisher-Weyl theorem is used instead. This simple observation might not be original, however it does not seem to show up in the literature. We also sketch the proof of additional inequalities for the singular values of matrices of seesaw type.
[ { "created": "Fri, 25 Nov 2016 09:41:57 GMT", "version": "v1" } ]
2016-11-29
[ [ "Besnard", "Fabien", "" ] ]
To demonstrate that matrices of seesaw type lead to a hieararchy in the neutrino masses, i.e. that there is a large gap in the singular spectrum of these matrices, one generally uses an approximate block-diagonalization procedure. In this note we show that no approximation is required to prove this gap property if the Courant-Fisher-Weyl theorem is used instead. This simple observation might not be original, however it does not seem to show up in the literature. We also sketch the proof of additional inequalities for the singular values of matrices of seesaw type.
0810.2128
Gary Goldstein
Gary R. Goldstein, Simonetta Liuti and Saeed Ahmad
Transversity via Exclusive pi0 Electroproduction
10 pages, 3 figures, presented at Transversity 2008, Second International Workshop on Transverse Polarization Phenomena in Hard Processes, Ferrara, Italy, May 28-31, 2008 Corrected references
null
10.1142/9789814277785_0011
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Exclusive pi0 electroproduction from nucleons can be related to transversity, the tensor charge, and other quantities related to transversity. This process isolates C-parity odd and chiral odd combinations of t-channel exchange quantum numbers. In a hadronic picture the meson production amplitudes for intermediate energy and Q are determined by C-odd Regge exchanges with final state interactions. The helicity structure for this C-odd process relates to the quark helicity flip, or chiral odd generalized parton distributions (GPDs).Various cross sections and asymmetries will be sensitive to the transversity.
[ { "created": "Sun, 12 Oct 2008 21:35:48 GMT", "version": "v1" }, { "created": "Mon, 20 Oct 2008 22:51:01 GMT", "version": "v2" } ]
2017-08-23
[ [ "Goldstein", "Gary R.", "" ], [ "Liuti", "Simonetta", "" ], [ "Ahmad", "Saeed", "" ] ]
Exclusive pi0 electroproduction from nucleons can be related to transversity, the tensor charge, and other quantities related to transversity. This process isolates C-parity odd and chiral odd combinations of t-channel exchange quantum numbers. In a hadronic picture the meson production amplitudes for intermediate energy and Q are determined by C-odd Regge exchanges with final state interactions. The helicity structure for this C-odd process relates to the quark helicity flip, or chiral odd generalized parton distributions (GPDs).Various cross sections and asymmetries will be sensitive to the transversity.
hep-ph/0312267
Steven Oliver
Z.Chacko, Lawrence J. Hall, Takemichi Okui and Steven J. Oliver
CMB Signals of Neutrino Mass Generation
40 pages, 4 figures
Phys.Rev. D70 (2004) 085008
10.1103/PhysRevD.70.085008
UCB-PTH-03/34 LBNL-54211 BUHEP-03-22
hep-ph astro-ph
null
We propose signals in the cosmic microwave background to probe the type and spectrum of neutrino masses. In theories that have spontaneous breaking of approximate lepton flavor symmetries at or below the weak scale, light pseudo-Goldstone bosons recouple to the cosmic neutrinos after nucleosynthesis and affect the acoustic oscillations of the electron-photon fluid during the eV era. Deviations from the Standard Model are predicted for both the total energy density in radiation during this epoch, \Delta N_nu, and for the multipole of the n'th CMB peak at large n, \Delta l_n. The latter signal is difficult to reproduce other than by scattering of the known neutrinos, and is therefore an ideal test of our class of theories. In many models, the large shift, \Delta l_n \approx 8 n_S, depends on the number of neutrino species that scatter via the pseudo-Goldstone boson interaction. This interaction is proportional to the neutrino masses, so that the signal reflects the neutrino spectrum. The prediction for \Delta N_nu is highly model dependent, but can be accurately computed within any given model. It is very sensitive to the number of pseudo-Goldstone bosons, and therefore to the underlying symmetries of the leptons, and is typically in the region of 0.03 < \Delta N_nu < 1. This signal is significantly larger for Majorana neutrinos than for Dirac neutrinos, and, like the scattering signal, varies as the spectrum of neutrinos is changed from hierarchical to inverse hierarchical to degenerate.
[ { "created": "Thu, 18 Dec 2003 20:32:49 GMT", "version": "v1" } ]
2009-11-10
[ [ "Chacko", "Z.", "" ], [ "Hall", "Lawrence J.", "" ], [ "Okui", "Takemichi", "" ], [ "Oliver", "Steven J.", "" ] ]
We propose signals in the cosmic microwave background to probe the type and spectrum of neutrino masses. In theories that have spontaneous breaking of approximate lepton flavor symmetries at or below the weak scale, light pseudo-Goldstone bosons recouple to the cosmic neutrinos after nucleosynthesis and affect the acoustic oscillations of the electron-photon fluid during the eV era. Deviations from the Standard Model are predicted for both the total energy density in radiation during this epoch, \Delta N_nu, and for the multipole of the n'th CMB peak at large n, \Delta l_n. The latter signal is difficult to reproduce other than by scattering of the known neutrinos, and is therefore an ideal test of our class of theories. In many models, the large shift, \Delta l_n \approx 8 n_S, depends on the number of neutrino species that scatter via the pseudo-Goldstone boson interaction. This interaction is proportional to the neutrino masses, so that the signal reflects the neutrino spectrum. The prediction for \Delta N_nu is highly model dependent, but can be accurately computed within any given model. It is very sensitive to the number of pseudo-Goldstone bosons, and therefore to the underlying symmetries of the leptons, and is typically in the region of 0.03 < \Delta N_nu < 1. This signal is significantly larger for Majorana neutrinos than for Dirac neutrinos, and, like the scattering signal, varies as the spectrum of neutrinos is changed from hierarchical to inverse hierarchical to degenerate.
hep-ph/0603167
Ezio Maina
E. Accomando, A. Ballestrero, A. Belhouari, E. Maina
Boson Fusion and Higgs production at the LHC in six fermion final states with one charged lepton pair
Final version published in Phys.Rev.D
Phys.Rev.D75:113006,2007
10.1103/PhysRevD.75.113006
DFTT 04/2006
hep-ph
null
Boson boson scattering and Higgs production in boson boson fusion will be actively investigated at the LHC. We have performed a parton level study of all processes of the type $q_1 q_2 \to q_3 q_4 q_5 q_6 l^+l^-$ using for the first time a full fledged six fermion Monte Carlo event generator which employs exact matrix elements at $\O(\alpha_{em}^6)$. We have examined Higgs production in vector boson fusion followed by the decay chain $H\to ZZ\to l^+l^-jj$, including exactly all electroweak irreducible backgrounds. In the high mass region we have compared the case of a relatively light Higgs with the no-Higgs case. The integrated cross section for the latter case is more than twice that in the former for a minimum invariant mass of the $ZV$ pair of about 800 \GeV. We find, in a preliminary anlysis at parton level that, summing up the muon and the electron channels, about 30 events are expected in the light Higgs case for L=100 $fb^{-1}$.
[ { "created": "Tue, 21 Mar 2006 18:55:00 GMT", "version": "v1" }, { "created": "Thu, 13 Apr 2006 09:43:19 GMT", "version": "v2" }, { "created": "Wed, 27 Sep 2006 18:06:57 GMT", "version": "v3" }, { "created": "Wed, 1 Aug 2007 13:53:53 GMT", "version": "v4" } ]
2009-09-29
[ [ "Accomando", "E.", "" ], [ "Ballestrero", "A.", "" ], [ "Belhouari", "A.", "" ], [ "Maina", "E.", "" ] ]
Boson boson scattering and Higgs production in boson boson fusion will be actively investigated at the LHC. We have performed a parton level study of all processes of the type $q_1 q_2 \to q_3 q_4 q_5 q_6 l^+l^-$ using for the first time a full fledged six fermion Monte Carlo event generator which employs exact matrix elements at $\O(\alpha_{em}^6)$. We have examined Higgs production in vector boson fusion followed by the decay chain $H\to ZZ\to l^+l^-jj$, including exactly all electroweak irreducible backgrounds. In the high mass region we have compared the case of a relatively light Higgs with the no-Higgs case. The integrated cross section for the latter case is more than twice that in the former for a minimum invariant mass of the $ZV$ pair of about 800 \GeV. We find, in a preliminary anlysis at parton level that, summing up the muon and the electron channels, about 30 events are expected in the light Higgs case for L=100 $fb^{-1}$.
hep-ph/9910227
Thomas Hahn
T. Hahn
Loop Calculations with FeynArts, FormCalc, and LoopTools
LaTeX, 7 pages, uses axodraw and appolb.cls. Talk given at the XXIII School of Theoretical Physics, Ustron, Poland, September 1999
Acta Phys.Polon.B30:3469-3475,1999
null
KA-TP-17-1999
hep-ph
null
Three programs are presented for automatically generating and calculating Feynman diagrams: the diagrams are generated with FeynArts, algebraically simplified with FormCalc, and finally evaluated numerically using the LoopTools package. The calculations are performed analytically as far as possible, with results given in a form well suited for numerical evaluation. The latter is then straightforward using the implementations of the one-loop integrals in LoopTools.
[ { "created": "Mon, 4 Oct 1999 21:30:02 GMT", "version": "v1" } ]
2011-04-15
[ [ "Hahn", "T.", "" ] ]
Three programs are presented for automatically generating and calculating Feynman diagrams: the diagrams are generated with FeynArts, algebraically simplified with FormCalc, and finally evaluated numerically using the LoopTools package. The calculations are performed analytically as far as possible, with results given in a form well suited for numerical evaluation. The latter is then straightforward using the implementations of the one-loop integrals in LoopTools.
1903.12190
Digvijay Wadekar
Digvijay Wadekar, Glennys R. Farrar
Gas-rich dwarf galaxies as a new probe of dark matter interactions with ordinary matter
5+10 pages, 4+6 figures. Version appearing in PRD. Title and abstract revised to reflect the primary message of the paper. Minor changes to figures, conclusions unchanged. The code associated with this paper is available at https://github.com/JayWadekar/Gas_rich_dwarfs
Phys. Rev. D 103, 123028 (2021)
10.1103/PhysRevD.103.123028
null
hep-ph astro-ph.GA
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We use observations of gas-rich dwarf galaxies to derive constraints on dark matter scattering with ordinary matter. We require that heating/cooling due to DM interacting with gas in the Leo T dwarf galaxy not exceed the ultra-low radiative cooling rate of the gas. This enables us to set $(i)$ stronger bounds than all the previous literature on ultra-light hidden photon DM for nearly all of the mass range $10^{-23}\lesssim m_\mathrm{DM} \lesssim 10^{-10}$ eV, $(ii)$ limits on sub-GeV millicharged DM which add to the constraints on the recent EDGES 21cm absorption anomaly, and $(iii)$ constraints on DM-baryon interactions directly at low relative velocities $v_\mathrm{rel}\sim 17$ km/s. Our study opens a new direction at using observations of gas-rich dwarf galaxies from previous, current and upcoming optical and 21cm surveys to probe physics beyond the standard model.
[ { "created": "Thu, 28 Mar 2019 18:00:19 GMT", "version": "v1" }, { "created": "Sun, 12 Jul 2020 16:10:44 GMT", "version": "v2" }, { "created": "Wed, 30 Jun 2021 18:00:02 GMT", "version": "v3" } ]
2021-07-02
[ [ "Wadekar", "Digvijay", "" ], [ "Farrar", "Glennys R.", "" ] ]
We use observations of gas-rich dwarf galaxies to derive constraints on dark matter scattering with ordinary matter. We require that heating/cooling due to DM interacting with gas in the Leo T dwarf galaxy not exceed the ultra-low radiative cooling rate of the gas. This enables us to set $(i)$ stronger bounds than all the previous literature on ultra-light hidden photon DM for nearly all of the mass range $10^{-23}\lesssim m_\mathrm{DM} \lesssim 10^{-10}$ eV, $(ii)$ limits on sub-GeV millicharged DM which add to the constraints on the recent EDGES 21cm absorption anomaly, and $(iii)$ constraints on DM-baryon interactions directly at low relative velocities $v_\mathrm{rel}\sim 17$ km/s. Our study opens a new direction at using observations of gas-rich dwarf galaxies from previous, current and upcoming optical and 21cm surveys to probe physics beyond the standard model.
1406.5885
Piotr Pietrulewicz
Andre H. Hoang, Piotr Pietrulewicz, Daniel Samitz
Variable Flavor Number Scheme for Final State Jets
7 pages, 4 figures, Proceedings of the XXII. International Workshop on Deep-Inelastic Scattering and Related Subjects, 28 April - 2 May 2014, Warsaw, Poland
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss a variable flavor number scheme (VFNS) for final state jets which can account for the effects of arbitrary finite quark masses in inclusive jet observables. The scheme is a generalization of the VFNS scheme for PDFs applied to setups with additional dynamical scales and relies on appropriate renormalization conditions for the matrix elements in the factorization theorem. We illustrate general properties by means of the example of deep-inelastic scattering (DIS) in the endpoint region $x\rightarrow 1$ and event shapes in the dijet limit, in particular the calculations of threshold corrections, consistency conditions and relations to mass singularities found in fixed-order massive calculations.
[ { "created": "Mon, 23 Jun 2014 12:40:09 GMT", "version": "v1" } ]
2015-01-05
[ [ "Hoang", "Andre H.", "" ], [ "Pietrulewicz", "Piotr", "" ], [ "Samitz", "Daniel", "" ] ]
We discuss a variable flavor number scheme (VFNS) for final state jets which can account for the effects of arbitrary finite quark masses in inclusive jet observables. The scheme is a generalization of the VFNS scheme for PDFs applied to setups with additional dynamical scales and relies on appropriate renormalization conditions for the matrix elements in the factorization theorem. We illustrate general properties by means of the example of deep-inelastic scattering (DIS) in the endpoint region $x\rightarrow 1$ and event shapes in the dijet limit, in particular the calculations of threshold corrections, consistency conditions and relations to mass singularities found in fixed-order massive calculations.
hep-ph/0605278
Dimitris Gioutsos
D. V. Gioutsos
Unification and fermion mass relations in low string scale D-brane models
10 pages, 3 figures. Talk presented at the ``Corfu Summer Institute'', Corfu-Greece, September 4-14, 2005. To appear in the proceedings of RTN workshop on the Quest for Unification Theory Confronts Experiment
null
10.1088/1742-6596/53/1/044
null
hep-ph
null
In this talk, gauge coupling evolution is analyzed in D-brane inspired models with two Higgs doublets and a U(3)xU(2)xU(1)^N gauge symmetry. In particular, we focus on D-brane configurations with two or three abelian factors. We find that the correct hypercharge assignment of the Standard Model particles is reproduced for six viable models distinguished by different brane configurations. We also investigate the bottom tau quark mass relation and find that the correct low energy m_b / m_\tau ratio is obtained for equal b-\tau Yukawa couplings at a string scale around 10^3 TeV.
[ { "created": "Thu, 25 May 2006 20:31:39 GMT", "version": "v1" } ]
2015-06-25
[ [ "Gioutsos", "D. V.", "" ] ]
In this talk, gauge coupling evolution is analyzed in D-brane inspired models with two Higgs doublets and a U(3)xU(2)xU(1)^N gauge symmetry. In particular, we focus on D-brane configurations with two or three abelian factors. We find that the correct hypercharge assignment of the Standard Model particles is reproduced for six viable models distinguished by different brane configurations. We also investigate the bottom tau quark mass relation and find that the correct low energy m_b / m_\tau ratio is obtained for equal b-\tau Yukawa couplings at a string scale around 10^3 TeV.
hep-ph/9907560
Fu-Guang Cao
Fu-Guang Cao and A. I. Signal (Institute of Fundamental Sciences, Massey University, New Zealand)
The flavour asymmetry and quark-antiquark asymmetry in the $\Sigma^+$-sea
RevTex, 12 pages, 4 Postscript figures. The effects from the input parton distribution evolution are discussed. Conclusions remain. Version to appear in Phys. Lett. B
Phys.Lett. B474 (2000) 138-144
10.1016/S0370-2693(99)01509-9
null
hep-ph
null
The sea quark content of the $\Sigma^+$ baryon is investigated using light-cone baryon-meson fluctuation model suggested by Brodsky and Ma. It is found that the $\Sigma^+$ sea is flavour asymmetric ($\dbar > \ubar > \sbar$) and quark-antiquark asymmetric ($q \not= \qbar$). Our prediction for the flavour asymmetry, $\dbar > \ubar > \sbar$, is significantly different from the SU(3) prediction ($\dbar < \ubar < \sbar$), while our prediction for the $d$-$\dbar$ asymmetry is consistent with the SU(3) prediction.
[ { "created": "Fri, 30 Jul 1999 09:32:11 GMT", "version": "v1" }, { "created": "Wed, 4 Aug 1999 22:38:03 GMT", "version": "v2" }, { "created": "Tue, 4 Jan 2000 23:36:26 GMT", "version": "v3" } ]
2009-10-31
[ [ "Cao", "Fu-Guang", "", "Institute of Fundamental Sciences,\n Massey University, New Zealand" ], [ "Signal", "A. I.", "", "Institute of Fundamental Sciences,\n Massey University, New Zealand" ] ]
The sea quark content of the $\Sigma^+$ baryon is investigated using light-cone baryon-meson fluctuation model suggested by Brodsky and Ma. It is found that the $\Sigma^+$ sea is flavour asymmetric ($\dbar > \ubar > \sbar$) and quark-antiquark asymmetric ($q \not= \qbar$). Our prediction for the flavour asymmetry, $\dbar > \ubar > \sbar$, is significantly different from the SU(3) prediction ($\dbar < \ubar < \sbar$), while our prediction for the $d$-$\dbar$ asymmetry is consistent with the SU(3) prediction.
hep-ph/0106087
Theodore Garavaglia
T. Garavaglia
Jets signal for Higgs particle detection at LHC
Lepton Photon Symposium 2001, Rome, 5 pages, plain tex, 1 ps figure
null
null
dias-stp-01-09
hep-ph
null
A method using jets is investigated for detecting the Higgs boson at LHC in the mass range about 114 \GeVc2, suggested by LEP experiments. Higgs bosons are produced in association with a $t \bar{t}$ pair, and both t and $\bar{t}$ decay semileptonically to reduce the QCD background. After appropriate cuts, the signal is compared with the main background, $t \bar{t} + 2$ jets. This estimate, using a reasonable approximation for the dominant background $t\bar {t}gg$, suggests a $5.1\sigma$ effect. This method is seen to be complimentary to the two gamma signal. The $t\bar{t}Z$ channel, with Z decaying to $l^+ l^-$, may be used to reduce theoretical uncertainties in determining the $t \bar{t}H$ signal.
[ { "created": "Fri, 8 Jun 2001 10:21:15 GMT", "version": "v1" } ]
2016-09-06
[ [ "Garavaglia", "T.", "" ] ]
A method using jets is investigated for detecting the Higgs boson at LHC in the mass range about 114 \GeVc2, suggested by LEP experiments. Higgs bosons are produced in association with a $t \bar{t}$ pair, and both t and $\bar{t}$ decay semileptonically to reduce the QCD background. After appropriate cuts, the signal is compared with the main background, $t \bar{t} + 2$ jets. This estimate, using a reasonable approximation for the dominant background $t\bar {t}gg$, suggests a $5.1\sigma$ effect. This method is seen to be complimentary to the two gamma signal. The $t\bar{t}Z$ channel, with Z decaying to $l^+ l^-$, may be used to reduce theoretical uncertainties in determining the $t \bar{t}H$ signal.
1312.4157
Nobuhito Maru
H. Itoyama and Nobuhito Maru
126 GeV Higgs Boson Associated with D-term Triggered Dynamical Supersymmetry Breaking
11 pages, 1 figure, A reference corrected, the argument of anomaly cancellation for an overall U(1) added
null
null
OCU-PHYS 395
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Continuing with our previous work on D-term triggered dynamical supersymmetry breaking, we consider a system in which our generic N=1 action is minimally extended to include the pair of Higgs doublet superfields charged under the overall U(1) as well as mu and B mu terms. The gauge group is taken to be SU(3)_C times SU(2)_L times U(1)_Y times U(1). We point out, among other things, that the Higgs mass less than the Z-boson mass at tree level can be pushed up to be around 126 GeV by D-term contributions of the overall U(1). This is readily realized by taking a U(1) gauge coupling of O(1).
[ { "created": "Sun, 15 Dec 2013 15:15:32 GMT", "version": "v1" }, { "created": "Wed, 18 Dec 2013 04:46:12 GMT", "version": "v2" }, { "created": "Thu, 18 Dec 2014 01:32:07 GMT", "version": "v3" } ]
2014-12-19
[ [ "Itoyama", "H.", "" ], [ "Maru", "Nobuhito", "" ] ]
Continuing with our previous work on D-term triggered dynamical supersymmetry breaking, we consider a system in which our generic N=1 action is minimally extended to include the pair of Higgs doublet superfields charged under the overall U(1) as well as mu and B mu terms. The gauge group is taken to be SU(3)_C times SU(2)_L times U(1)_Y times U(1). We point out, among other things, that the Higgs mass less than the Z-boson mass at tree level can be pushed up to be around 126 GeV by D-term contributions of the overall U(1). This is readily realized by taking a U(1) gauge coupling of O(1).
2008.04908
Patricio Gaete
Patricio Gaete, J. A. Helay\"el-Neto and L. P. R. Ospedal
Remarks on an anomalous triple gauge boson couplings
5 pages
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We address the effect of an anomalous triple gauge boson couplings on a physical observable for the electroweak sector of the Standard Model, when the $SU(2)_{L}\otimes U(1)_{Y}$ symmetry is spontaneously broken by the Higgs mechanism to $U(1)_{em}$. Our calculation is done within the framework of the gauge-invariant, but path-dependent variable formalism which is alternative to the Wilson loop approach. Our result shows that the interaction energy is the sum of a Yukawa and a linear potential, leading to the confinement of static probe charges. The point we wish to emphasize, however, is that the anomalous triple gauge boson couplings ($Z \gamma \gamma$) contributes to the confinement for distances on the intranuclear scale.
[ { "created": "Tue, 11 Aug 2020 15:45:38 GMT", "version": "v1" }, { "created": "Tue, 1 Dec 2020 17:42:50 GMT", "version": "v2" } ]
2020-12-02
[ [ "Gaete", "Patricio", "" ], [ "Helayël-Neto", "J. A.", "" ], [ "Ospedal", "L. P. R.", "" ] ]
We address the effect of an anomalous triple gauge boson couplings on a physical observable for the electroweak sector of the Standard Model, when the $SU(2)_{L}\otimes U(1)_{Y}$ symmetry is spontaneously broken by the Higgs mechanism to $U(1)_{em}$. Our calculation is done within the framework of the gauge-invariant, but path-dependent variable formalism which is alternative to the Wilson loop approach. Our result shows that the interaction energy is the sum of a Yukawa and a linear potential, leading to the confinement of static probe charges. The point we wish to emphasize, however, is that the anomalous triple gauge boson couplings ($Z \gamma \gamma$) contributes to the confinement for distances on the intranuclear scale.
1708.02138
Hiroki Matsui
Kazunori Kohri, Hiroki Matsui
Electroweak Vacuum Collapse induced by Vacuum Fluctuations of the Higgs Field around Evaporating Black Holes
10 pages, 3 figure, References added, Published version in PRD
Phys. Rev. D 98, 123509 (2018)
10.1103/PhysRevD.98.123509
KEK-TH-1989, KEK-Cosmo-208
hep-ph astro-ph.CO gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we discuss the Higgs vacuum stability around evaporating black holes. We provide a new approach to investigate the false vacuum decay around the black hole and clearly show how vacuum fluctuations of the Higgs induce a gravitational collapse of the vacuum. Furthermore, we point out that the backreaction of the Hawking radiation can not be ignored and the gravitational vacuum decay is exponentially suppressed. However, a large number of the evaporating (or evaporated) primordial black holes threaten the existence of the Universe and we obtain a new upper bound on the evaporating PBH abundance from the vacuum stability. Finally, we show that the high-order corrections of the BSM or QG would not destabilize the Higgs potential, otherwise even a single evaporating black hole triggers a collapse of the electroweak vacuum.
[ { "created": "Mon, 7 Aug 2017 14:46:02 GMT", "version": "v1" }, { "created": "Thu, 25 Oct 2018 12:23:59 GMT", "version": "v2" }, { "created": "Mon, 10 Dec 2018 12:22:47 GMT", "version": "v3" } ]
2018-12-14
[ [ "Kohri", "Kazunori", "" ], [ "Matsui", "Hiroki", "" ] ]
In this paper, we discuss the Higgs vacuum stability around evaporating black holes. We provide a new approach to investigate the false vacuum decay around the black hole and clearly show how vacuum fluctuations of the Higgs induce a gravitational collapse of the vacuum. Furthermore, we point out that the backreaction of the Hawking radiation can not be ignored and the gravitational vacuum decay is exponentially suppressed. However, a large number of the evaporating (or evaporated) primordial black holes threaten the existence of the Universe and we obtain a new upper bound on the evaporating PBH abundance from the vacuum stability. Finally, we show that the high-order corrections of the BSM or QG would not destabilize the Higgs potential, otherwise even a single evaporating black hole triggers a collapse of the electroweak vacuum.
hep-ph/9912404
null
A.A. Osipov, B. Hiller, A.H. Blin (University of Coimbra, Portugal)
One-Loop Determinant of Dirac Operator in Non-Renormalizable Models
8 pages, LaTex
Phys.Lett. B475 (2000) 324-328
10.1016/S0370-2693(00)00106-4
null
hep-ph
null
We use proper-time regularizations to define the one-loop fermion determinant in the form suggested by Gasser and Leutwyler some years ago. We show how to obtain the polynomial by which this definition of ln det D needs to be modified in order to arrive at the fermion determinant whose modulus is invarinat under chiral transformations. As an example it is shown how the fundamental symmetries associated with the NJL model are preserved in a consistent way.
[ { "created": "Fri, 17 Dec 1999 14:58:28 GMT", "version": "v1" } ]
2009-10-31
[ [ "Osipov", "A. A.", "", "University of Coimbra, Portugal" ], [ "Hiller", "B.", "", "University of Coimbra, Portugal" ], [ "Blin", "A. H.", "", "University of Coimbra, Portugal" ] ]
We use proper-time regularizations to define the one-loop fermion determinant in the form suggested by Gasser and Leutwyler some years ago. We show how to obtain the polynomial by which this definition of ln det D needs to be modified in order to arrive at the fermion determinant whose modulus is invarinat under chiral transformations. As an example it is shown how the fundamental symmetries associated with the NJL model are preserved in a consistent way.
1609.03698
Alka Upadhyay
Amanpreet Kaur, Alka Upadhyay
J/P=1/2+, J/P=3/2+ masses in statistical model
14 pages, 4 tables
Eur.Phys.J. A52 (2016) no.11, 332 (2016-11-16)
10.1140/epja/i2016-16332-6
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The mass formulae for the baryon octet and decuplet are calculated. These formulae are function of constituent quark masses and spin spin interaction terms for the quarks inside the baryons. The coefficients in the mass formulae is estimated by the statistical model for J/P=1/2+, J/P=3/2+, incorporating the contributions from \sea" containing uu; dd; ss pairs and gluons . The measured masses are presented and found to be matching good with some of the experimental and theoretical data.
[ { "created": "Tue, 13 Sep 2016 06:49:54 GMT", "version": "v1" } ]
2018-01-08
[ [ "Kaur", "Amanpreet", "" ], [ "Upadhyay", "Alka", "" ] ]
The mass formulae for the baryon octet and decuplet are calculated. These formulae are function of constituent quark masses and spin spin interaction terms for the quarks inside the baryons. The coefficients in the mass formulae is estimated by the statistical model for J/P=1/2+, J/P=3/2+, incorporating the contributions from \sea" containing uu; dd; ss pairs and gluons . The measured masses are presented and found to be matching good with some of the experimental and theoretical data.
hep-ph/9806521
Isi Dunietz
Isard Dunietz
CP Asymmetries in (Semi-)Inclusive B0 Decays
RevTex, 20 pages, no figures
Eur.Phys.J.C7:197-203,1999
10.1007/s100529801005
FERMILAB--PUB--97/323--T
hep-ph
null
It was recently pointed out that inclusive B^0(t) decays could show CP violation. The totally inclusive asymmetry is expected to be tiny [O(10^{-3})] because of large cancellations among the asymmetries in the charmless, single charm and double charm final states. Enriching particular final state configurations could significantly increase the CP-asymmetry and observability. Such studies can extract fundamental CKM (Cabibbo-Kobayashi-Maskawa) parameters, and (perhaps) even Delta m(B_s). A superb vertex detector could see CP violation with 10^5 (10^6) flavor-tagged B_s (B_d) mesons within the CKM model. Because the effects could be significantly larger due to new physics, they should be searched for in existing or soon available data samples.
[ { "created": "Mon, 29 Jun 1998 20:15:54 GMT", "version": "v1" } ]
2014-11-17
[ [ "Dunietz", "Isard", "" ] ]
It was recently pointed out that inclusive B^0(t) decays could show CP violation. The totally inclusive asymmetry is expected to be tiny [O(10^{-3})] because of large cancellations among the asymmetries in the charmless, single charm and double charm final states. Enriching particular final state configurations could significantly increase the CP-asymmetry and observability. Such studies can extract fundamental CKM (Cabibbo-Kobayashi-Maskawa) parameters, and (perhaps) even Delta m(B_s). A superb vertex detector could see CP violation with 10^5 (10^6) flavor-tagged B_s (B_d) mesons within the CKM model. Because the effects could be significantly larger due to new physics, they should be searched for in existing or soon available data samples.
hep-ph/0304289
Herbert Dreiner
H. K. Dreiner (Bonn U.), C. Hanhart (FZ-Julich), U. Langenfeld (Bonn U.), and D. R. Phillips (Ohio U.)
Supernovae and Light Neutralinos: SN1987A Bounds on Supersymmetry Revisited
29 pages, Latex, 9 figures, axodraw.sty
Phys.Rev.D68:055004,2003
10.1103/PhysRevD.68.055004
BONN-TH-2003-01; FZJ-IKP-TH-2003-3
hep-ph astro-ph
null
For non-universal gaugino masses, collider experiments do not provide any lower bound on the mass of the lightest neutralino. We review the supersymmetric parameter space which leads to light neutralinos, $M_\lsp \lsim {\cal O}(1\gev)$, and find that such neutralinos are almost pure bino. In light of this, we examine the neutralino lower mass bound obtained from supernova 1987A (SN1987A). We consider the production of binos in both electron-positron annihilation and nucleon-nucleon binostrahlung. For electron-positron annihilation, we take into account the radial and temporal dependence of the temperature and degeneracy of the supernova core. We also separately consider the Raffelt criterion and show that the two lead to consistent results. For the case of bino production in $NN$ collisions, we use the Raffelt criterion and incorporate recent advances in the understanding of the strong-interaction part of the calculation in order to estimate the impact of bino radiation on the SN1987A neutrino signal. Considering these two bino production channels allows us to determine separate and combined limits on the neutralino mass as a function of the selectron and squark masses. For $M_\lsp \sim 100 \mev$ values of the selectron mass between 300 and 900 GeV are inconsistent with the supernova neutrino signal. On the other hand, in contrast to previous works, we find that SN1987A provides almost no bound on the squark masses: only a small window of values around 300 GeV can be excluded, and even then this window closes once $M_\lsp \gsim 20 \mev$.
[ { "created": "Wed, 30 Apr 2003 12:55:32 GMT", "version": "v1" } ]
2009-04-17
[ [ "Dreiner", "H. K.", "", "Bonn U." ], [ "Hanhart", "C.", "", "FZ-Julich" ], [ "Langenfeld", "U.", "", "Bonn\n U." ], [ "Phillips", "D. R.", "", "Ohio U." ] ]
For non-universal gaugino masses, collider experiments do not provide any lower bound on the mass of the lightest neutralino. We review the supersymmetric parameter space which leads to light neutralinos, $M_\lsp \lsim {\cal O}(1\gev)$, and find that such neutralinos are almost pure bino. In light of this, we examine the neutralino lower mass bound obtained from supernova 1987A (SN1987A). We consider the production of binos in both electron-positron annihilation and nucleon-nucleon binostrahlung. For electron-positron annihilation, we take into account the radial and temporal dependence of the temperature and degeneracy of the supernova core. We also separately consider the Raffelt criterion and show that the two lead to consistent results. For the case of bino production in $NN$ collisions, we use the Raffelt criterion and incorporate recent advances in the understanding of the strong-interaction part of the calculation in order to estimate the impact of bino radiation on the SN1987A neutrino signal. Considering these two bino production channels allows us to determine separate and combined limits on the neutralino mass as a function of the selectron and squark masses. For $M_\lsp \sim 100 \mev$ values of the selectron mass between 300 and 900 GeV are inconsistent with the supernova neutrino signal. On the other hand, in contrast to previous works, we find that SN1987A provides almost no bound on the squark masses: only a small window of values around 300 GeV can be excluded, and even then this window closes once $M_\lsp \gsim 20 \mev$.
1409.4198
C. Q. Geng
Wei-Chi Chiu, Chao-Qiang Geng, Da Huang
Correlation Between Muon $g-2$ and $\mu\rightarrow{e}{\gamma}$
22 pages, 4 figures, updated version accepted by PRD
Phys. Rev. D91, 013006 (2015)
10.1103/PhysRevD.91.013006
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
While the muon $g-2$ anomaly can be successfully explained by some new physics models, most of them are severely constrained by the $\mu \to e \gamma$ bound. This tension is more transparent from the effective field theory perspective, in which the two phenomena are encoded in two very similar operators. However, with the ${\cal O}(1)$ Wilson coefficients, the current upper bound on $\mu \to e \gamma$ indicates a new-physics cutoff scale five orders smaller than that needed to eliminate the $(g-2)_\mu$ anomaly. By summarizing all the formulae from the one-loop contributions to the muon $g-2$ with the internal-particle spin not larger than 1, we point out two general methods to reconcile the conflict between the muon $g-2$ and $\mu \to e \gamma$: the GIM mechanism and the non-universal couplings. For the latter method, we use a simple scalar leptoquark model as an illustration.
[ { "created": "Mon, 15 Sep 2014 10:10:08 GMT", "version": "v1" }, { "created": "Sat, 20 Sep 2014 08:30:28 GMT", "version": "v2" }, { "created": "Sat, 20 Dec 2014 00:11:31 GMT", "version": "v3" } ]
2015-01-20
[ [ "Chiu", "Wei-Chi", "" ], [ "Geng", "Chao-Qiang", "" ], [ "Huang", "Da", "" ] ]
While the muon $g-2$ anomaly can be successfully explained by some new physics models, most of them are severely constrained by the $\mu \to e \gamma$ bound. This tension is more transparent from the effective field theory perspective, in which the two phenomena are encoded in two very similar operators. However, with the ${\cal O}(1)$ Wilson coefficients, the current upper bound on $\mu \to e \gamma$ indicates a new-physics cutoff scale five orders smaller than that needed to eliminate the $(g-2)_\mu$ anomaly. By summarizing all the formulae from the one-loop contributions to the muon $g-2$ with the internal-particle spin not larger than 1, we point out two general methods to reconcile the conflict between the muon $g-2$ and $\mu \to e \gamma$: the GIM mechanism and the non-universal couplings. For the latter method, we use a simple scalar leptoquark model as an illustration.
2211.10548
Ian Nugent Dr.
Ian M. Nugent
{\tt ee$\in$MC}: Arbitrary Initial Spin States for the Production of $\bf e^{+}e^{-} \to \tau^{+}\tau^{-} (\gamma) $ Events and the Impact on Spin Correlations
6 pages, 2 Figures
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a modified spin algorithm, including spin correlations, which has been implemented in {\tt ee$\in$MC} for the simulation of $e^{+}e^{-} \to \tau^{+}\tau^{-} (\gamma)$ events with an arbitrary initial spin configuration. This algorithm is suitable for the proposed BELLE-II polarization upgrade to SuperKEKB, both for the ideal case and for the case where there are misalignments, radiative effects and allows for changing polarization conditions. The spin $1/2$ states of the polarized beams are constructed in terms of a super-positioning of the helicity states corresponding to the polarimetric-vector describing the overall beam polarization and implemented both through a modification of the initial state in the modified Altrelli-Parsis Density Function as well as a change of basis of the helicity states.
[ { "created": "Sat, 19 Nov 2022 00:51:06 GMT", "version": "v1" }, { "created": "Tue, 22 Nov 2022 17:54:22 GMT", "version": "v2" }, { "created": "Wed, 7 Dec 2022 00:32:44 GMT", "version": "v3" } ]
2022-12-08
[ [ "Nugent", "Ian M.", "" ] ]
We present a modified spin algorithm, including spin correlations, which has been implemented in {\tt ee$\in$MC} for the simulation of $e^{+}e^{-} \to \tau^{+}\tau^{-} (\gamma)$ events with an arbitrary initial spin configuration. This algorithm is suitable for the proposed BELLE-II polarization upgrade to SuperKEKB, both for the ideal case and for the case where there are misalignments, radiative effects and allows for changing polarization conditions. The spin $1/2$ states of the polarized beams are constructed in terms of a super-positioning of the helicity states corresponding to the polarimetric-vector describing the overall beam polarization and implemented both through a modification of the initial state in the modified Altrelli-Parsis Density Function as well as a change of basis of the helicity states.
2105.02160
Alexander A. Osipov
M.K. Volkov, A.A. Osipov, A.A. Pivovarov, K. Nurlan
$1/N_c$ approximation and universality of vector mesons
9 pages, 2 figuras, the version accepted for publication in Physical Review D
Phys. Rev. D 104, 034021 (2021)
10.1103/PhysRevD.104.034021
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this work, we argue that the observed differences in the value of the vector coupling constant extracted from the decays $\rho\to \pi\pi$ ($g_{\rho} = 6.0$), $\rho\to l^+l^-$ ($g_{\rho} = 5.0 $) and $\omega\to l^+ l^-$ ($g_{\rho} = 5.7$), where $l=e,\mu $, are an indication of the important role played by the $1/N_c$ corrections in the description of these processes. We show that an emission of a photon by charged meson loops in the $\rho^0, \omega,\phi\to\gamma$ transitions is a key process that allows to describe above vector meson decays into two leptons with a single value $g_\rho = 6.0$. Our result supports the idea of universality of neutral vector mesons and clarifies the role of accounting of $1/N_c$ corrections to its fulfilment.
[ { "created": "Wed, 5 May 2021 16:14:48 GMT", "version": "v1" }, { "created": "Wed, 4 Aug 2021 18:54:42 GMT", "version": "v2" } ]
2021-08-23
[ [ "Volkov", "M. K.", "" ], [ "Osipov", "A. A.", "" ], [ "Pivovarov", "A. A.", "" ], [ "Nurlan", "K.", "" ] ]
In this work, we argue that the observed differences in the value of the vector coupling constant extracted from the decays $\rho\to \pi\pi$ ($g_{\rho} = 6.0$), $\rho\to l^+l^-$ ($g_{\rho} = 5.0 $) and $\omega\to l^+ l^-$ ($g_{\rho} = 5.7$), where $l=e,\mu $, are an indication of the important role played by the $1/N_c$ corrections in the description of these processes. We show that an emission of a photon by charged meson loops in the $\rho^0, \omega,\phi\to\gamma$ transitions is a key process that allows to describe above vector meson decays into two leptons with a single value $g_\rho = 6.0$. Our result supports the idea of universality of neutral vector mesons and clarifies the role of accounting of $1/N_c$ corrections to its fulfilment.
2306.10266
Mohd Siddique Akbar Alam Khan
M. S. A. Alam Khan
Renormalization group improved determination of light quark masses from Borel-Laplace sum rules
21 pages and 21 figures. Figures updated, new section added, equations corrected, references updated, and other text correction. Version accepted for publication is Phys. Rev. D
null
null
null
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We determine masses of light quarks ($m_u$,$m_d$,$m_s$) using Borel-Laplace sum rules and renormalization group summed perturbation theory (RGSPT) from the divergence of the axial vector current. The RGSPT significantly reduces the scale dependence of the finite order perturbative series for the renormalization group (RG) invariant quantities such as spectral function, the second derivative of the polarization function of the pseudoscalar current correlator, and its Borel transformation. In addition, the convergence of the spectral function is significantly improved by summing all running logarithms and kinematical $\pi^2$-terms. Using RGSPT, we find $m_s(2 GeV)=104.34_{-4.21}^{+4.23}\hs\MeV$, and $m_d(2 GeV)=4.21_{-0.45}^{+0.48}\hs\MeV$ leading to $m_u(2 GeV)=2.00_{-0.40}^{+0.33}\hs\MeV$.
[ { "created": "Sat, 17 Jun 2023 05:58:31 GMT", "version": "v1" }, { "created": "Tue, 27 Jun 2023 16:54:31 GMT", "version": "v2" }, { "created": "Mon, 16 Oct 2023 17:42:02 GMT", "version": "v3" } ]
2023-10-17
[ [ "Khan", "M. S. A. Alam", "" ] ]
We determine masses of light quarks ($m_u$,$m_d$,$m_s$) using Borel-Laplace sum rules and renormalization group summed perturbation theory (RGSPT) from the divergence of the axial vector current. The RGSPT significantly reduces the scale dependence of the finite order perturbative series for the renormalization group (RG) invariant quantities such as spectral function, the second derivative of the polarization function of the pseudoscalar current correlator, and its Borel transformation. In addition, the convergence of the spectral function is significantly improved by summing all running logarithms and kinematical $\pi^2$-terms. Using RGSPT, we find $m_s(2 GeV)=104.34_{-4.21}^{+4.23}\hs\MeV$, and $m_d(2 GeV)=4.21_{-0.45}^{+0.48}\hs\MeV$ leading to $m_u(2 GeV)=2.00_{-0.40}^{+0.33}\hs\MeV$.
hep-ph/0008031
David Miller
David E. Miller
Gluon condensates at finite temperature
10 pages, 2 ps-figures, Latex 2e
null
null
BI-TP 2000/17
hep-ph hep-lat
null
We consider various special cases of gluon condensates at finite temperature. The gluon condensate for an ideal gas of gluons with a given vacuum expectation value is introduced for the sake of comparison with that calculated using the recent finite temperature lattice gauge simulations for a pure Yang-Mills SU(3) gauge theory at the known critical temperature. We extend this comparison using the high precision lattice data for two light dynamical quarks. The investigation of these three cases show some interesting differences arising from the strong interaction alone and in the presence of quarks. In this context we discuss some newer simulations for heavier quarks and other properties related to gluon condensation.
[ { "created": "Thu, 3 Aug 2000 13:06:27 GMT", "version": "v1" } ]
2007-05-23
[ [ "Miller", "David E.", "" ] ]
We consider various special cases of gluon condensates at finite temperature. The gluon condensate for an ideal gas of gluons with a given vacuum expectation value is introduced for the sake of comparison with that calculated using the recent finite temperature lattice gauge simulations for a pure Yang-Mills SU(3) gauge theory at the known critical temperature. We extend this comparison using the high precision lattice data for two light dynamical quarks. The investigation of these three cases show some interesting differences arising from the strong interaction alone and in the presence of quarks. In this context we discuss some newer simulations for heavier quarks and other properties related to gluon condensation.
1312.5318
Manuel Krauss
Manuel E. Krauss, Werner Porod, Florian Staub, Asmaa Abada, Avelino Vicente and C\'edric Weiland
Decoupling of heavy sneutrinos in low-scale seesaw models
7 pages, 2 figures; v2: minor changes, appendix added; matches published version in PRD
Phys. Rev. D 90, 013008 (2014)
10.1103/PhysRevD.90.013008
Bonn-TH-2013-09, LPT-Orsay-13-140, FTUAM-14-39, IFT-UAM/CSIC-14-065
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
There have been some recent claims in the literature about large right-handed sneutrinos contributions to lepton flavor violating observables like $\mu \to 3e$ or $\mu - e$ conversion in nuclei in supersymmetric low-scale seesaw models. These large contributions originate from $Z$-penguin diagrams which show a much weaker dependence on the heavy masses than the photonic contributions. We have traced this to an error in the evaluation of the corresponding loop amplitudes which has propagated in the literature. We explicitly show that after correcting this mistake the $Z$-penguins show the expected decoupling behavior. Moreover, the reported dominance of the $Z$-penguin over the photonic contributions disappears as well.
[ { "created": "Wed, 18 Dec 2013 21:00:05 GMT", "version": "v1" }, { "created": "Fri, 11 Jul 2014 13:34:49 GMT", "version": "v2" } ]
2014-07-14
[ [ "Krauss", "Manuel E.", "" ], [ "Porod", "Werner", "" ], [ "Staub", "Florian", "" ], [ "Abada", "Asmaa", "" ], [ "Vicente", "Avelino", "" ], [ "Weiland", "Cédric", "" ] ]
There have been some recent claims in the literature about large right-handed sneutrinos contributions to lepton flavor violating observables like $\mu \to 3e$ or $\mu - e$ conversion in nuclei in supersymmetric low-scale seesaw models. These large contributions originate from $Z$-penguin diagrams which show a much weaker dependence on the heavy masses than the photonic contributions. We have traced this to an error in the evaluation of the corresponding loop amplitudes which has propagated in the literature. We explicitly show that after correcting this mistake the $Z$-penguins show the expected decoupling behavior. Moreover, the reported dominance of the $Z$-penguin over the photonic contributions disappears as well.
1711.02864
Simone Biondini
Simone Biondini, Dietrich Bodeker, Nora Brambilla, Mathias Garny, Jacopo Ghiglieri, Andreas Hohenegger, Mikko Laine, Sebastian Mendizabal, Peter Millington, Alberto Salvio and Antonio Vairo
Status of rates and rate equations for thermal leptogenesis
31 pages, 6 figures. Chapter 4 of the review volume "Leptogenesis: Current Challenges for Model Building, Phenomenology and Non-Equilibrium Field Theory"
Int.J.Mod.Phys. A33 (2018) no.05n06, 1842004
10.1142/S0217751X18420046
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In many realizations of leptogenesis, heavy right-handed neutrinos play the main role in the generation of an imbalance between matter and antimatter in the early Universe. Hence, it is relevant to address quantitatively their dynamics in a hot and dense environment by taking into account the various thermal aspects of the problem at hand. The strong washout regime offers an interesting framework to carry out calculations systematically and reduce theoretical uncertainties. Indeed, any matter-antimatter asymmetry generated when the temperature of the hot plasma $T$ exceeds the right-handed neutrino mass scale $M$ is efficiently erased, and one can focus on the temperature window $T \ll M$. We review recent progresses in the thermal field theoretic derivation of the key ingredients for the leptogenesis mechanism: the right-handed neutrino production rate, the CP asymmetry in the heavy-neutrino decays and the washout rates. The derivation of evolution equations for the heavy-neutrino and lepton-asymmetry number densities, their rigorous formulation and applicability are also discussed.
[ { "created": "Wed, 8 Nov 2017 08:15:07 GMT", "version": "v1" }, { "created": "Fri, 9 Mar 2018 13:03:48 GMT", "version": "v2" } ]
2018-03-12
[ [ "Biondini", "Simone", "" ], [ "Bodeker", "Dietrich", "" ], [ "Brambilla", "Nora", "" ], [ "Garny", "Mathias", "" ], [ "Ghiglieri", "Jacopo", "" ], [ "Hohenegger", "Andreas", "" ], [ "Laine", "Mikko", "" ]...
In many realizations of leptogenesis, heavy right-handed neutrinos play the main role in the generation of an imbalance between matter and antimatter in the early Universe. Hence, it is relevant to address quantitatively their dynamics in a hot and dense environment by taking into account the various thermal aspects of the problem at hand. The strong washout regime offers an interesting framework to carry out calculations systematically and reduce theoretical uncertainties. Indeed, any matter-antimatter asymmetry generated when the temperature of the hot plasma $T$ exceeds the right-handed neutrino mass scale $M$ is efficiently erased, and one can focus on the temperature window $T \ll M$. We review recent progresses in the thermal field theoretic derivation of the key ingredients for the leptogenesis mechanism: the right-handed neutrino production rate, the CP asymmetry in the heavy-neutrino decays and the washout rates. The derivation of evolution equations for the heavy-neutrino and lepton-asymmetry number densities, their rigorous formulation and applicability are also discussed.
hep-ph/0001174
Liao Wei
Chao-Shang Huang, Liao Wei
The Electric Dipole Moment and CP Violation in $B \to X_s l^+ l^-$ in SUGRA Models with Nonuniversal Gaugino Masses
12 pages, latex, 4 figures, a few changes
Phys.Rev. D62 (2000) 016008
10.1103/PhysRevD.62.016008
null
hep-ph
null
The constraints of electric dipole moments (EDMs) of electron and neutron on the parameter space in supergravity (SUGRA) models with nonuniversal gaugino masses are analyzed. It is shown that with a light sparticle spectrum, the sufficient cancellations in the calculation of EDMs can happen for all phases being order of one in the small tan$\beta$ case and all phases but $\phi_{\mu}$ ($|\phi_{\mu}| <\sim \pi/6$) order of one in the large tan$\beta$ case. This is in contrast to the case of mSUGRA in which in the parameter space where cancellations among various SUSY contributions to EDMs happen $|\phi_{\mu}|$ must be less than $\pi/10$ for small $tan\beta$ and ${\cal{O}}(10^{-2})$ for large $tan\beta$. Direct CP asymmetries and the T-odd polarization of lepton in $B\to X_s l^+l^-$ are investigated in the models. In the large tan$\beta$ case, $A_{CP}^2$ and $P_N$ for l=$\mu$ ($\tau$) can be enhanced by about a factor of ten (ten) and ten (three) respectively compared to those of mSUGRA.
[ { "created": "Tue, 18 Jan 2000 05:12:23 GMT", "version": "v1" }, { "created": "Wed, 1 Mar 2000 06:48:56 GMT", "version": "v2" }, { "created": "Sun, 14 May 2000 08:59:57 GMT", "version": "v3" } ]
2016-09-06
[ [ "Huang", "Chao-Shang", "" ], [ "Wei", "Liao", "" ] ]
The constraints of electric dipole moments (EDMs) of electron and neutron on the parameter space in supergravity (SUGRA) models with nonuniversal gaugino masses are analyzed. It is shown that with a light sparticle spectrum, the sufficient cancellations in the calculation of EDMs can happen for all phases being order of one in the small tan$\beta$ case and all phases but $\phi_{\mu}$ ($|\phi_{\mu}| <\sim \pi/6$) order of one in the large tan$\beta$ case. This is in contrast to the case of mSUGRA in which in the parameter space where cancellations among various SUSY contributions to EDMs happen $|\phi_{\mu}|$ must be less than $\pi/10$ for small $tan\beta$ and ${\cal{O}}(10^{-2})$ for large $tan\beta$. Direct CP asymmetries and the T-odd polarization of lepton in $B\to X_s l^+l^-$ are investigated in the models. In the large tan$\beta$ case, $A_{CP}^2$ and $P_N$ for l=$\mu$ ($\tau$) can be enhanced by about a factor of ten (ten) and ten (three) respectively compared to those of mSUGRA.
0901.2534
Jose Edelstein
Jose D. Edelstein, Jonathan P. Shock, Dimitrios Zoakos
The AdS/CFT Correspondence and Non-perturbative QCD
20 pages, 8 figures, summary of the general overview lecture and the technical talk given by JDE in the XIII Mexican School of Particles and Fields held at San Carlos, October 2008; v2: minor amendments, figures and bibliography improved, final version
AIP Conf.Proc.1116:265-284,2009
10.1063/1.3131566
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We aim at providing an overview on the applications of the AdS/CFT correspondence to non-perturbative aspects of non-Abelian gauge theories, addressed to particle physicists. The finite temperature case, in connection with the physics of the quark-gluon plasma, is emphasized.
[ { "created": "Fri, 16 Jan 2009 17:49:59 GMT", "version": "v1" }, { "created": "Tue, 27 Jan 2009 19:01:24 GMT", "version": "v2" } ]
2009-05-29
[ [ "Edelstein", "Jose D.", "" ], [ "Shock", "Jonathan P.", "" ], [ "Zoakos", "Dimitrios", "" ] ]
We aim at providing an overview on the applications of the AdS/CFT correspondence to non-perturbative aspects of non-Abelian gauge theories, addressed to particle physicists. The finite temperature case, in connection with the physics of the quark-gluon plasma, is emphasized.
hep-ph/0210252
Piotr Golonka
P. Golonka, T. Pierzchala, Z. Was
MC-TESTER: a universal tool for comparisons of Monte Carlo predictions for particle decays in high energy physics
Version as published in Computer Physics Communications, 157(2004) 1, pp 39-62
Comput.Phys.Commun. 157 (2004) 39-62
10.1016/S0010-4655(03)00466-1
CERN-TH/2002-271 ; TP-USl-01/02
hep-ph
null
Theoretical predictions in high energy physics are routinely provided in the form of Monte Carlo generators. Comparisons of predictions from different programs and/or different initialization set-ups are often necessary. MC-TESTER can be used for such tests of decays of intermediate states (particles or resonances) in a semi-automated way. Our test consists of two steps. Different Monte Carlo programs are run; events with decays of a chosen particle are searched, decay trees are analysed and appropriate information is stored. Then, at the analysis step, a list of all found decay modes is defined and branching ratios are calculated for both runs. Histograms of all scalar Lorentz-invariant masses constructed from the decay products are plotted and compared for each decay mode found in both runs. For each plot a measure of the difference of the distributions is calculated and its maximal value over all histograms for each decay channel is printed in a summary table. As an example of MC-TESTER application, we include a test with the tau lepton decay Monte Carlo generators, TAUOLA and PYTHIA. The HEPEVT (or LUJETS) common block is used as exclusive source of information on the generated events.
[ { "created": "Thu, 17 Oct 2002 17:53:31 GMT", "version": "v1" }, { "created": "Fri, 6 Feb 2004 10:08:16 GMT", "version": "v2" } ]
2007-05-23
[ [ "Golonka", "P.", "" ], [ "Pierzchala", "T.", "" ], [ "Was", "Z.", "" ] ]
Theoretical predictions in high energy physics are routinely provided in the form of Monte Carlo generators. Comparisons of predictions from different programs and/or different initialization set-ups are often necessary. MC-TESTER can be used for such tests of decays of intermediate states (particles or resonances) in a semi-automated way. Our test consists of two steps. Different Monte Carlo programs are run; events with decays of a chosen particle are searched, decay trees are analysed and appropriate information is stored. Then, at the analysis step, a list of all found decay modes is defined and branching ratios are calculated for both runs. Histograms of all scalar Lorentz-invariant masses constructed from the decay products are plotted and compared for each decay mode found in both runs. For each plot a measure of the difference of the distributions is calculated and its maximal value over all histograms for each decay channel is printed in a summary table. As an example of MC-TESTER application, we include a test with the tau lepton decay Monte Carlo generators, TAUOLA and PYTHIA. The HEPEVT (or LUJETS) common block is used as exclusive source of information on the generated events.
0908.2219
Krzysztof Urbanowski
K. Urbanowski, J. Piskorski
Energy of unstable states at long times
21 pages, 9 figures, Talk given at the "14th Lomonosov Conference on Elementary Particle Physics", Moscow, Russia, August 19 -- 25, 2009; 1 Figure added, typos corrected
null
null
null
hep-ph astro-ph.CO quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An effect generated by the nonexponential behavior of the survival amplitude of an unstable state in the long time region is considered. In 1957 Khalfin proved that this amplitude tends to zero as $t\to\infty$ more slowly than any exponential function of $t$. For a time-dependent decay rate $\gamma(t)$ Khalfin's result means that this $\gamma(t)$ is not a constant for large $t$ but that it tends to zero as $t\to\infty$. We find that a similar conclusion can be drawn for the instantaneous energy of the unstable state for a large class of models of unstable states: This energy tends to the minimal energy of the system ${\cal E}_{min}$ as $t\to\infty$ which is much smaller than the energy of this state for $t$ of the order of the lifetime of the considered state. Analyzing the transition time region between exponential and non-exponential form of the survival amplitude we find that the instantaneous energy of a considered unstable state can take large values, much larger than the energy of this state for $t$ from the exponential time region. Taking into account results obtained for a model considered, it is hypothesized that this purely quantum mechanical effect may be responsible for the properties of broad resonances such as $\sigma$ meson as well as having astrophysical and cosmological consequences.
[ { "created": "Sun, 16 Aug 2009 07:59:15 GMT", "version": "v1" }, { "created": "Fri, 28 Aug 2009 11:15:37 GMT", "version": "v2" } ]
2009-09-02
[ [ "Urbanowski", "K.", "" ], [ "Piskorski", "J.", "" ] ]
An effect generated by the nonexponential behavior of the survival amplitude of an unstable state in the long time region is considered. In 1957 Khalfin proved that this amplitude tends to zero as $t\to\infty$ more slowly than any exponential function of $t$. For a time-dependent decay rate $\gamma(t)$ Khalfin's result means that this $\gamma(t)$ is not a constant for large $t$ but that it tends to zero as $t\to\infty$. We find that a similar conclusion can be drawn for the instantaneous energy of the unstable state for a large class of models of unstable states: This energy tends to the minimal energy of the system ${\cal E}_{min}$ as $t\to\infty$ which is much smaller than the energy of this state for $t$ of the order of the lifetime of the considered state. Analyzing the transition time region between exponential and non-exponential form of the survival amplitude we find that the instantaneous energy of a considered unstable state can take large values, much larger than the energy of this state for $t$ from the exponential time region. Taking into account results obtained for a model considered, it is hypothesized that this purely quantum mechanical effect may be responsible for the properties of broad resonances such as $\sigma$ meson as well as having astrophysical and cosmological consequences.
1408.7048
Michael Strickland
Gabriel S. Denicol (McGill), Ulrich W. Heinz (Ohio State), Mauricio Martinez (Ohio State), Jorge Noronha (Univ. Sao Paulo), Michael Strickland (Kent State)
Studying the validity of relativistic hydrodynamics with a new exact solution of the Boltzmann equation
37 pages, 10 figures; v1.1 of code is included as ancillary files; v3 - published version
Phys. Rev. D 90, 125026 (2014)
10.1103/PhysRevD.90.125026
null
hep-ph cond-mat.stat-mech nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an exact solution to the Boltzmann equation which describes a system undergoing boost-invariant longitudinal and azimuthally symmetric radial expansion for arbitrary shear viscosity to entropy density ratio. This new solution is constructed by considering the conformal map between Minkowski space and the direct product of three dimensional de Sitter space with a line. The resulting solution respects SO(3)_q x SO(1,1) x Z_2 symmetry. We compare the exact kinetic solution with exact solutions of the corresponding macroscopic equations that were obtained from the kinetic theory in ideal and second-order viscous hydrodynamic approximations. The macroscopic solutions are obtained in de Sitter space and are subject to the same symmetries used to obtain the exact kinetic solution.
[ { "created": "Fri, 29 Aug 2014 15:04:02 GMT", "version": "v1" }, { "created": "Wed, 10 Sep 2014 14:56:31 GMT", "version": "v2" }, { "created": "Thu, 25 Dec 2014 17:43:44 GMT", "version": "v3" } ]
2014-12-30
[ [ "Denicol", "Gabriel S.", "", "McGill" ], [ "Heinz", "Ulrich W.", "", "Ohio State" ], [ "Martinez", "Mauricio", "", "Ohio State" ], [ "Noronha", "Jorge", "", "Univ. Sao Paulo" ], [ "Strickland", "Michael", "", "Kent Sta...
We present an exact solution to the Boltzmann equation which describes a system undergoing boost-invariant longitudinal and azimuthally symmetric radial expansion for arbitrary shear viscosity to entropy density ratio. This new solution is constructed by considering the conformal map between Minkowski space and the direct product of three dimensional de Sitter space with a line. The resulting solution respects SO(3)_q x SO(1,1) x Z_2 symmetry. We compare the exact kinetic solution with exact solutions of the corresponding macroscopic equations that were obtained from the kinetic theory in ideal and second-order viscous hydrodynamic approximations. The macroscopic solutions are obtained in de Sitter space and are subject to the same symmetries used to obtain the exact kinetic solution.
0709.0395
Peter Landshoff
P. V. Landshoff
The total cross section at the LHC
Lectures at School on QCD, Calabria, July 2007
Acta Phys.Polon.B39:2063-2094,2008
null
DAMTP-2007-82
hep-ph hep-ex
null
We do not have the ability to perform precise calculations of long-range strong interaction effects, because the effective QCD coupling is not small and so we cannot use perturbation theory. Nevertheless, I show that we know a lot, though not nearly enough. As a measure of our lack of knowledge, the best prediction for the total cross section at LHC energy is 125 +/- 25 mb.
[ { "created": "Tue, 4 Sep 2007 14:05:44 GMT", "version": "v1" } ]
2008-12-19
[ [ "Landshoff", "P. V.", "" ] ]
We do not have the ability to perform precise calculations of long-range strong interaction effects, because the effective QCD coupling is not small and so we cannot use perturbation theory. Nevertheless, I show that we know a lot, though not nearly enough. As a measure of our lack of knowledge, the best prediction for the total cross section at LHC energy is 125 +/- 25 mb.
1109.1096
Chung Wen Kao
Chung Wen Kao and Seung-il Nam
QCD Chiral restoration at finite $T$ under the Magnetic field: Studies based on the instanton vacuum model
4 pages, 1 table, 6figs. arXiv admin note: significant text overlap with arXiv:1103.6057
null
10.1007/s00601-012-0352-z
KIAS-P11050,CYCU-HEP-11-16
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the chiral restoration at finite temperature $(T)$ under the strong external magnetic field $\vec{B}=B_{0}\hat{z}$ of the SU(2) light-flavor QCD matter. We employ the instanton-liquid QCD vacuum configuration accompanied with the linear Schwinger method for inducing the magnetic field. The Harrington-Shepard caloron solution is used to modify the instanton parameters, i.e. the average instanton size $(\bar{\rho})$ and inter-instanton distance $(\bar{R})$, as functions of $T$. In addition, we include the meson-loop corrections (MLC) as the large-$N_{c}$ corrections because they are critical for reproducing the universal chiral restoration pattern. We present the numerical results for the constituent-quark mass as well as chiral condensate which signal the spontaneous breakdown of chiral-symmetry (SB$\chi$S), as functions of $T$ and $B$. Besides we find that the changes for the $F_\pi$ and $m_\pi$ due to the magnetic field is relatively small, in comparison to those caused by the finite $T$ effect.
[ { "created": "Tue, 6 Sep 2011 07:34:05 GMT", "version": "v1" } ]
2015-05-30
[ [ "Kao", "Chung Wen", "" ], [ "Nam", "Seung-il", "" ] ]
We investigate the chiral restoration at finite temperature $(T)$ under the strong external magnetic field $\vec{B}=B_{0}\hat{z}$ of the SU(2) light-flavor QCD matter. We employ the instanton-liquid QCD vacuum configuration accompanied with the linear Schwinger method for inducing the magnetic field. The Harrington-Shepard caloron solution is used to modify the instanton parameters, i.e. the average instanton size $(\bar{\rho})$ and inter-instanton distance $(\bar{R})$, as functions of $T$. In addition, we include the meson-loop corrections (MLC) as the large-$N_{c}$ corrections because they are critical for reproducing the universal chiral restoration pattern. We present the numerical results for the constituent-quark mass as well as chiral condensate which signal the spontaneous breakdown of chiral-symmetry (SB$\chi$S), as functions of $T$ and $B$. Besides we find that the changes for the $F_\pi$ and $m_\pi$ due to the magnetic field is relatively small, in comparison to those caused by the finite $T$ effect.
1211.2277
Jian-Rong Zhang
Jian-Rong Zhang
Study of $X_{c}(3250)$ as a $D_{0}^{*}(2400)N$ molecular state
8 pages, 4 eps figures, some references and more discussions added
Phys. Rev. D 87, 076008 (2013)
10.1103/PhysRevD.87.076008
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a QCD sum rule analysis for the newly observed resonance $X_{c}(3250)$ by assuming it as a $D_{0}^{*}(2400)N$ molecular state. Technically, contributions of operators up to dimension 12 are included in the operator product expansion (OPE). We find that it is difficult to find the conventional OPE convergence in this work. By trying releasing the rigid OPE convergence criterion, one could find that the OPE convergence is still under control in the present work and the numerical result for $D_{0}^{*}(2400)N$ state is $3.18\pm0.51 {GeV}$, which is in agreement with the experimental data of $X_{c}(3250)$. In view of that the conventional OPE convergence is not obtained here, thus only weak conclusions can be drawn regarding the explanation of $X_{c}(3250)$ in terms of a $D_{0}^{*}(2400)N$ molecular state. As a byproduct, the mass for the bottom counterpart $\bar{B}_{0}^{*}N$ state is predicted to be $6.50\pm0.49 {GeV}$.
[ { "created": "Sat, 10 Nov 2012 01:41:46 GMT", "version": "v1" }, { "created": "Fri, 12 Apr 2013 02:53:16 GMT", "version": "v2" } ]
2013-04-15
[ [ "Zhang", "Jian-Rong", "" ] ]
We present a QCD sum rule analysis for the newly observed resonance $X_{c}(3250)$ by assuming it as a $D_{0}^{*}(2400)N$ molecular state. Technically, contributions of operators up to dimension 12 are included in the operator product expansion (OPE). We find that it is difficult to find the conventional OPE convergence in this work. By trying releasing the rigid OPE convergence criterion, one could find that the OPE convergence is still under control in the present work and the numerical result for $D_{0}^{*}(2400)N$ state is $3.18\pm0.51 {GeV}$, which is in agreement with the experimental data of $X_{c}(3250)$. In view of that the conventional OPE convergence is not obtained here, thus only weak conclusions can be drawn regarding the explanation of $X_{c}(3250)$ in terms of a $D_{0}^{*}(2400)N$ molecular state. As a byproduct, the mass for the bottom counterpart $\bar{B}_{0}^{*}N$ state is predicted to be $6.50\pm0.49 {GeV}$.
hep-ph/9401253
null
P. Q. Hung
A phenomenological Theory of Fermion Masses and Mixings
13 pages RevTeX, INPP-UVA-94-1
Mod.Phys.Lett.A9:1745-1754,1994
10.1142/S0217732394001593
null
hep-ph
null
A phenomenological theory of fermion masses and mixings is constructed within the framework of a four- family symmetry. It is found that the most favored set of relevant CKM elements are $|V_{us}|\approx 0.222$, $|V_{cb}|\approx 0.044$, $|V_{ub}/V_{cb}|\approx 0.082$, $|V_{ud}|\approx 0.974$, $|V_{cs}|\approx 0.9736$, $|V_{cd}|\approx 0.224$ with $\hat{B}_K \approx 0.8$. The top quark mass is predicted to be 258 GeV at 1 GeV with its physical mass approximately equal to 153 GeV. The Majorana scale associated with the fourth neutrino is bound from above to be 6.4 TeV.
[ { "created": "Fri, 14 Jan 1994 09:34:42 GMT", "version": "v1" } ]
2010-11-01
[ [ "Hung", "P. Q.", "" ] ]
A phenomenological theory of fermion masses and mixings is constructed within the framework of a four- family symmetry. It is found that the most favored set of relevant CKM elements are $|V_{us}|\approx 0.222$, $|V_{cb}|\approx 0.044$, $|V_{ub}/V_{cb}|\approx 0.082$, $|V_{ud}|\approx 0.974$, $|V_{cs}|\approx 0.9736$, $|V_{cd}|\approx 0.224$ with $\hat{B}_K \approx 0.8$. The top quark mass is predicted to be 258 GeV at 1 GeV with its physical mass approximately equal to 153 GeV. The Majorana scale associated with the fourth neutrino is bound from above to be 6.4 TeV.
1908.05309
Yonghui Lin
Yong-Hui Lin and Bing-Song Zou
Strong decays of the latest LHCb pentaquark candidates in hadronic molecule pictures
13 pages,8 figures
Phys. Rev. D 100, 056005 (2019)
10.1103/PhysRevD.100.056005
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the observed pentaquark candidates $P_c(4312)$, $P_c(4440)$ and $P_c(4457)$ from the latest LHCb measurement, as well as four possible spin partners in the $\bar{D}^{(*)}\Sigma_c^*$ system predicted from the heavy quark spin symmetry with the hadronic molecule scenarios. Similar to the previous calculation on $P_c(4380)$ and $P_c(4450)$, the partial widths of all the allowed decay channels for these $P_c$ states are estimated with the effective Lagrangian method. The cutoff dependence of our numerical results are also presented. Comparing with the experimental widths, our results show that $P_c(4312)$, $P_c(4440)$ and $P_c(4457)$ can be described well with the spin-parity-$1/2^-$-$\bar{D}\Sigma_c$, $1/2^-$-$\bar{D}^*\Sigma_c$ and $3/2^-$-$\bar{D}^*\Sigma_c$ molecule pictures, respectively.
[ { "created": "Wed, 14 Aug 2019 18:53:05 GMT", "version": "v1" } ]
2019-09-18
[ [ "Lin", "Yong-Hui", "" ], [ "Zou", "Bing-Song", "" ] ]
We investigate the observed pentaquark candidates $P_c(4312)$, $P_c(4440)$ and $P_c(4457)$ from the latest LHCb measurement, as well as four possible spin partners in the $\bar{D}^{(*)}\Sigma_c^*$ system predicted from the heavy quark spin symmetry with the hadronic molecule scenarios. Similar to the previous calculation on $P_c(4380)$ and $P_c(4450)$, the partial widths of all the allowed decay channels for these $P_c$ states are estimated with the effective Lagrangian method. The cutoff dependence of our numerical results are also presented. Comparing with the experimental widths, our results show that $P_c(4312)$, $P_c(4440)$ and $P_c(4457)$ can be described well with the spin-parity-$1/2^-$-$\bar{D}\Sigma_c$, $1/2^-$-$\bar{D}^*\Sigma_c$ and $3/2^-$-$\bar{D}^*\Sigma_c$ molecule pictures, respectively.
hep-ph/9811355
Jing Wang
G. Cleaver, M. Cvetic, J. R. Espinosa, L. Everett, P. Langacker and J. Wang
Physics Implications of Flat Directions in Free Fermionic Superstring Models II: Renormalization Group Analysis
38 pages, 5 figures, LaTex. Minor corrections
Phys.Rev.D59:115003,1999
10.1103/PhysRevD.59.115003
null
hep-ph hep-th
null
We continue the investigation of the physics implications of a class of flat directions for a prototype quasi-realistic free fermionic string model (CHL5), building upon the results of the previous paper in which the complete mass spectrum and effective trilinear couplings of the observable sector were calculated to all orders in the superpotential. We introduce soft supersymmetry breaking mass parameters into the model, and investigate the gauge symmetry breaking patterns and the renormalization group analysis for two representative flat directions, which leave an additional $U(1)'$ as well as the SM gauge group unbroken at the string scale. We study symmetry breaking patterns that lead to a phenomenologically acceptable $Z-Z'$ hierarchy, $M_{Z^{'}} \sim {\cal O}(1~{\rm TeV})$ and $ 10^{12}~{\rm GeV}$ for electroweak and intermediate scale $U(1)^{'}$ symmetry breaking, respectively, and the associated mass spectra after electroweak symmetry breaking. The fermion mass spectrum exhibits unrealistic features, including massless exotic fermions, but has an interesting $d$-quark hierarchy and associated CKM matrix in one case. There are (some) non-canonical effective $\mu$ terms, which lead to a non-minimal Higgs sector with more than two Higgs doublets involved in the symmetry breaking, and a rich structure of Higgs particles, charginos, and neutralinos, some of which, however, are massless or ultralight. In the electroweak scale cases the scale of supersymmetry breaking is set by the $Z^{'}$ mass, with the sparticle masses in the several TeV range.
[ { "created": "Mon, 16 Nov 1998 23:04:44 GMT", "version": "v1" }, { "created": "Fri, 18 Dec 1998 00:01:40 GMT", "version": "v2" } ]
2009-09-17
[ [ "Cleaver", "G.", "" ], [ "Cvetic", "M.", "" ], [ "Espinosa", "J. R.", "" ], [ "Everett", "L.", "" ], [ "Langacker", "P.", "" ], [ "Wang", "J.", "" ] ]
We continue the investigation of the physics implications of a class of flat directions for a prototype quasi-realistic free fermionic string model (CHL5), building upon the results of the previous paper in which the complete mass spectrum and effective trilinear couplings of the observable sector were calculated to all orders in the superpotential. We introduce soft supersymmetry breaking mass parameters into the model, and investigate the gauge symmetry breaking patterns and the renormalization group analysis for two representative flat directions, which leave an additional $U(1)'$ as well as the SM gauge group unbroken at the string scale. We study symmetry breaking patterns that lead to a phenomenologically acceptable $Z-Z'$ hierarchy, $M_{Z^{'}} \sim {\cal O}(1~{\rm TeV})$ and $ 10^{12}~{\rm GeV}$ for electroweak and intermediate scale $U(1)^{'}$ symmetry breaking, respectively, and the associated mass spectra after electroweak symmetry breaking. The fermion mass spectrum exhibits unrealistic features, including massless exotic fermions, but has an interesting $d$-quark hierarchy and associated CKM matrix in one case. There are (some) non-canonical effective $\mu$ terms, which lead to a non-minimal Higgs sector with more than two Higgs doublets involved in the symmetry breaking, and a rich structure of Higgs particles, charginos, and neutralinos, some of which, however, are massless or ultralight. In the electroweak scale cases the scale of supersymmetry breaking is set by the $Z^{'}$ mass, with the sparticle masses in the several TeV range.
1905.03764
Aleandro Nisati
J. de Blas (1 and 2), M. Cepeda (3), J. D'Hondt (4), R. K. Ellis (5), C. Grojean (6 and 7), B. Heinemann (6 and 8), F. Maltoni (9 and 10), A. Nisati (11), E. Petit (12), R. Rattazzi (13), W. Verkerke (14) ((1) Dipartimento di Fisica e Astronomia Galileo Galilei, Universita di Padova, Italy, (2) Istituto Nazionale di Fisica Nucleare (INFN), Italy, (3) Centro de Investigaciones Energ\'eticas, Medioambientales y Tecnol\'ogicas (CIEMAT), Spain, (4) Inter-University Institute for High Energies (IIHE), Vrije Universiteit Brussel, Belgium, (5) IPPP, University of Durham, UK, (6) Deutsches Elektronen-Synchrotron (DESY), Germany, (7) Institut f\"ur Physik, Humboldt-Universit\"at, Germany, (8) Albert-Ludwigs-Universit\"at Freiburg, Germany, (9) Centre for Cosmology, Particle Physics and Phenomenology, Universit\'e catholique de Louvain, Belgium, (10) Dipartimento di Fisica e Astronomia, Universit\`a di Bologna and INFN, Sezione di Bologna, Italy, (11) Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Roma, Italy, (12) Aix Marseille Univ, CNRS/IN2P3, CPPM, Marseille, France, (13) Theoretical Particle Physics Laboratory (LPTP), EPFL, Switzerland, (14) Nikhef and University of Amsterdam, the Netherlands)
Higgs Boson Studies at Future Particle Colliders
75 pages
null
10.1007/JHEP01(2020)139
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
This document aims to provide an assessment of the potential of future colliding beam facilities to perform Higgs boson studies. The analysis builds on the submissions made by the proponents of future colliders to the European Strategy Update process, and takes as its point of departure the results expected at the completion of the HL-LHC program. This report presents quantitative results on many aspects of Higgs physics for future collider projects of sufficient maturity using uniform methodologies. A first version of this report was prepared for the purposes of discussion at the Open Symposium in Granada (13-16/05/2019). Comments and feedback received led to the consideration of additional run scenarios as well as a refined analysis of the impact of electroweak measurements on the Higgs coupling extraction.
[ { "created": "Thu, 9 May 2019 17:34:52 GMT", "version": "v1" }, { "created": "Wed, 25 Sep 2019 16:40:26 GMT", "version": "v2" } ]
2020-02-19
[ [ "de Blas", "J.", "", "1 and 2" ], [ "Cepeda", "M.", "", "6 and 7" ], [ "D'Hondt", "J.", "", "6 and 7" ], [ "Ellis", "R. K.", "", "6 and 7" ], [ "Grojean", "C.", "", "6 and 7" ], [ "Heinemann", "B.", "",...
This document aims to provide an assessment of the potential of future colliding beam facilities to perform Higgs boson studies. The analysis builds on the submissions made by the proponents of future colliders to the European Strategy Update process, and takes as its point of departure the results expected at the completion of the HL-LHC program. This report presents quantitative results on many aspects of Higgs physics for future collider projects of sufficient maturity using uniform methodologies. A first version of this report was prepared for the purposes of discussion at the Open Symposium in Granada (13-16/05/2019). Comments and feedback received led to the consideration of additional run scenarios as well as a refined analysis of the impact of electroweak measurements on the Higgs coupling extraction.
hep-ph/9606213
Jorge Portoles
G. D'Ambrosio, J. Portoles (INFN-Sezione di Napoli)
Unitarity and vector meson contributions to K^+ -> pi^+ gamma gamma
15 pages, LaTex, 4 figures included as PS files, uuencoded with uufiles, submitted to Phys. Lett. B
Phys.Lett. B386 (1996) 403-412; Phys.Lett. B389 (1996) 770-780
10.1016/S0370-2693(96)01476-1
INFNNA-IV-96/12,DSFNA-IV-96/12
hep-ph
null
We compute the one-loop unitarity corrections O(p^6) from K^+ -> pi^+ pi^+ pi^- to K^+ -> pi^+ gamma gamma and we find they are relevant, increasing the leading order prediction for the width in a 30-40%. The contributions of local O(p^6) amplitudes, generated by vector meson exchange, are discussed in several models and we conclude that the vector resonance contribution should be negligible compared to the unitarity corrections.
[ { "created": "Mon, 3 Jun 1996 21:54:44 GMT", "version": "v1" } ]
2009-10-28
[ [ "D'Ambrosio", "G.", "", "INFN-Sezione di Napoli" ], [ "Portoles", "J.", "", "INFN-Sezione di Napoli" ] ]
We compute the one-loop unitarity corrections O(p^6) from K^+ -> pi^+ pi^+ pi^- to K^+ -> pi^+ gamma gamma and we find they are relevant, increasing the leading order prediction for the width in a 30-40%. The contributions of local O(p^6) amplitudes, generated by vector meson exchange, are discussed in several models and we conclude that the vector resonance contribution should be negligible compared to the unitarity corrections.
1405.0206
Ipsita Saha
Dilip Kumar Ghosh, Subhadeep Mondal, Ipsita Saha
Confronting the Galactic Center Gamma Ray Excess With a Light Scalar Dark Matter
19 pages, 5 figures, version accepted for publication in JCAP
null
10.1088/1475-7516/2015/02/035
null
hep-ph astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Fermi Large Area Telescope observed an excess in gamma ray emission spectrum coming from the center of the Milky Way galaxy. This data reveals that a light Dark Matter (DM) candidate of mass in the range 31-40 GeV, dominantly decaying into $b\bar b$ final state, can explain the presence of the observed bump in photon energy. We try to interpret this observed phenomena by sneutrino DM annihilation into pair of fermions in the Supersymmetric Inverse Seesaw Model (SISM). This model can also account for tiny non-zero neutrino masses satisfying existing neutrino oscillation data. We show that a Higgs portal DM in this model is in perfect agreement with this new interpretation besides satisfying all other existing collider, cosmological and low energy experimental constraints.
[ { "created": "Thu, 1 May 2014 16:12:18 GMT", "version": "v1" }, { "created": "Mon, 26 Jan 2015 16:05:22 GMT", "version": "v2" } ]
2015-06-19
[ [ "Ghosh", "Dilip Kumar", "" ], [ "Mondal", "Subhadeep", "" ], [ "Saha", "Ipsita", "" ] ]
The Fermi Large Area Telescope observed an excess in gamma ray emission spectrum coming from the center of the Milky Way galaxy. This data reveals that a light Dark Matter (DM) candidate of mass in the range 31-40 GeV, dominantly decaying into $b\bar b$ final state, can explain the presence of the observed bump in photon energy. We try to interpret this observed phenomena by sneutrino DM annihilation into pair of fermions in the Supersymmetric Inverse Seesaw Model (SISM). This model can also account for tiny non-zero neutrino masses satisfying existing neutrino oscillation data. We show that a Higgs portal DM in this model is in perfect agreement with this new interpretation besides satisfying all other existing collider, cosmological and low energy experimental constraints.
1305.3892
Alexander Mitov
Michal Czakon, Paul Fiedler, Alexander Mitov and Juan Rojo
Further exploration of top pair hadroproduction at NNLO
8 pages, 8 figures. Contribution to the proceedings of the twenty-seventh workshop "Les Rencontres de Physique de la Vall\'ee d'Aoste", held 24 Feb.-02 Mar. 2013 in La Thuile, Aosta Valley, Italy
null
null
CERN-PH-TH/2013-100, TTK-13-15
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Top quark pair production is one of the cornerstones of the physics program at hadron colliders. In this contribution, we further explore the phenomenological implications of the recent NNLO calculation of the total inclusive cross-section. We provide a comparison of the scale dependence of the top pair hadroproduction cross section at different perturbative orders and study its perturbative convergence (with and without soft-gluon resummation). We also sketch how the NNLO top quark cross-section could be used to improve searches of physics beyond the Standard Model.
[ { "created": "Thu, 16 May 2013 19:19:13 GMT", "version": "v1" } ]
2013-05-17
[ [ "Czakon", "Michal", "" ], [ "Fiedler", "Paul", "" ], [ "Mitov", "Alexander", "" ], [ "Rojo", "Juan", "" ] ]
Top quark pair production is one of the cornerstones of the physics program at hadron colliders. In this contribution, we further explore the phenomenological implications of the recent NNLO calculation of the total inclusive cross-section. We provide a comparison of the scale dependence of the top pair hadroproduction cross section at different perturbative orders and study its perturbative convergence (with and without soft-gluon resummation). We also sketch how the NNLO top quark cross-section could be used to improve searches of physics beyond the Standard Model.
1909.07070
Chen Gang
Zhi-Lei She, Gang Chen, Feng-Xian Liu, Liang Zheng and Yi-Long Xie
Study of nuclear modification factors of (anti-)hadrons and light (anti-)nuclei in Pb-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 2.76 TeV
8 pages, 5 figures
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The nuclear modification factors ($R_{AA}$) of $\pi^{\pm}, p(\bar p)$, and $d(\bar d)$ with $|y|<0.5, p_T<20.0$~GeV/c in peripheral (40-60\%) and central (0-5\%) Pb-Pb collisions at $\sqrt {s_{NN}}=2.76$ TeV have been studied using the parton and hadron cascade ({\footnotesize PACIAE}) model plus the dynamically constrained phase space coalescence ({\footnotesize DCPC}) model. It is found that the $R_{AA}$ of light (anti)nuclei ($d, \bar d$) is similar to that of hadrons ($\pi^\pm, p, \bar p$), and the $R_{AA}$ of antiparticles is the same as that of particles. The suppression of $R_{AA}$ at high-$p_T$ strongly depends on event centrality and mass of the particles, i.e., the central collision is more suppressed than the peripheral collision. Besides, the yield ratios and double ratios for different particle species in $pp$ and Pb-Pb collisions are discussed, respectively. It is observed that the yield ratios and double ratios of $d$ to $p$ and $p$ to $\pi$ are similar to those of their anti-particles in three different collision systems, suggesting that the suppressions of matter ($\pi^{+}, p, d$) and the corresponding antimatter ($\pi^{-},\bar{p},\bar{d}$) are around the same level.
[ { "created": "Mon, 16 Sep 2019 08:58:42 GMT", "version": "v1" }, { "created": "Sun, 19 Jul 2020 04:33:02 GMT", "version": "v2" }, { "created": "Mon, 23 Nov 2020 13:28:26 GMT", "version": "v3" } ]
2020-11-24
[ [ "She", "Zhi-Lei", "" ], [ "Chen", "Gang", "" ], [ "Liu", "Feng-Xian", "" ], [ "Zheng", "Liang", "" ], [ "Xie", "Yi-Long", "" ] ]
The nuclear modification factors ($R_{AA}$) of $\pi^{\pm}, p(\bar p)$, and $d(\bar d)$ with $|y|<0.5, p_T<20.0$~GeV/c in peripheral (40-60\%) and central (0-5\%) Pb-Pb collisions at $\sqrt {s_{NN}}=2.76$ TeV have been studied using the parton and hadron cascade ({\footnotesize PACIAE}) model plus the dynamically constrained phase space coalescence ({\footnotesize DCPC}) model. It is found that the $R_{AA}$ of light (anti)nuclei ($d, \bar d$) is similar to that of hadrons ($\pi^\pm, p, \bar p$), and the $R_{AA}$ of antiparticles is the same as that of particles. The suppression of $R_{AA}$ at high-$p_T$ strongly depends on event centrality and mass of the particles, i.e., the central collision is more suppressed than the peripheral collision. Besides, the yield ratios and double ratios for different particle species in $pp$ and Pb-Pb collisions are discussed, respectively. It is observed that the yield ratios and double ratios of $d$ to $p$ and $p$ to $\pi$ are similar to those of their anti-particles in three different collision systems, suggesting that the suppressions of matter ($\pi^{+}, p, d$) and the corresponding antimatter ($\pi^{-},\bar{p},\bar{d}$) are around the same level.
hep-ph/0610358
Yu-Xin Liu
Yue Zhao, Lei Chang, Wei Yuan, and Yu-xin Liu
Relation Between Chiral Susceptibility and Solutions of Gap Equation in Nambu--Jona-Lasinio Model
21 pages, 6 figures, misprints are corrected
European Physical Journal C 56: 483-492 (2008)
10.1140/epjc/s10052-008-0673-8
null
hep-ph nucl-th
null
We study the solutions of the gap equation, the thermodynamic potential and the chiral susceptibility in and beyond the chiral limit at finite chemical potential in the Nambu--Jona-Lasinio (NJL) model. We give an explicit relation between the chiral susceptibility and the thermodynamic potential in the NJL model. We find that the chiral susceptibility is a quantity being able to represent the furcation of the solutions of the gap equation and the concavo-convexity of the thermodynamic potential in NJL model. It indicates that the chiral susceptibility can identify the stable state and the possibility of the chiral phase transition in NJL model.
[ { "created": "Thu, 26 Oct 2006 17:27:18 GMT", "version": "v1" }, { "created": "Sat, 28 Oct 2006 15:43:38 GMT", "version": "v2" } ]
2017-01-11
[ [ "Zhao", "Yue", "" ], [ "Chang", "Lei", "" ], [ "Yuan", "Wei", "" ], [ "Liu", "Yu-xin", "" ] ]
We study the solutions of the gap equation, the thermodynamic potential and the chiral susceptibility in and beyond the chiral limit at finite chemical potential in the Nambu--Jona-Lasinio (NJL) model. We give an explicit relation between the chiral susceptibility and the thermodynamic potential in the NJL model. We find that the chiral susceptibility is a quantity being able to represent the furcation of the solutions of the gap equation and the concavo-convexity of the thermodynamic potential in NJL model. It indicates that the chiral susceptibility can identify the stable state and the possibility of the chiral phase transition in NJL model.
1601.04788
Yusuke Shimizu
Yu Muramatsu, Takaaki Nomura, and Yusuke Shimizu
Mass Limit for Light Flavon with Residual $Z_3$ Symmetry
14 pages, final version
null
10.1007/JHEP03(2016)192
KIAS-Q16001
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a modified Altarelli and Feruglio $A_4$ model where an additional $A_4$ singlet-prime flavon is introduced. In this model, non-zero $\theta _{13}$ is given by this additional $A_4$ singlet-prime flavon which breaks tri-bimaximal mixing. In the framework of the supersymmetry with $U(1)_R$ symmetry, we obtain vacuum expectation values (VEVs) and VEV alignments of flavons through driving fields. It is considered that flavon induces distinctive flavor violating process if flavon mass is light. Assuming mass of SUSY particles are sufficiently heavy so that the SUSY contributions can be negligible, we discuss the flavor violating Yukawa interaction through flavon exchange in the charged lepton sector. According to the potential analysis, the VEV of flavon breaks $A_4$ down to $Z_3$ in the charged lepton sector and relation among flavon masses is determined. Thanks for the residual $Z_3$ symmetry, many lepton flavor violating decay modes are forbidden except for $\tau \rightarrow \mu \mu \bar{e}$ and $\tau \rightarrow e e \bar{\mu}$. A mass limit of the flavon from these three-body decay modes is $60$~GeV taking into account the current experimental lower bounds at the Belle experiment. In our model, we predict a ratio of the branching ratios $\tau \rightarrow \mu \mu \bar{e}$ and $\tau \rightarrow e e \bar{\mu}$ by using known charged lepton masses. We also find that the production cross section for the flavon can be $\mathcal{O}(1)$ fb. Thus the flavon would be found at the LHC run 2 by searching for 4-tau lepton signal.
[ { "created": "Tue, 19 Jan 2016 03:58:00 GMT", "version": "v1" }, { "created": "Tue, 26 Jan 2016 04:31:20 GMT", "version": "v2" }, { "created": "Tue, 26 Apr 2016 12:45:47 GMT", "version": "v3" } ]
2016-04-27
[ [ "Muramatsu", "Yu", "" ], [ "Nomura", "Takaaki", "" ], [ "Shimizu", "Yusuke", "" ] ]
We present a modified Altarelli and Feruglio $A_4$ model where an additional $A_4$ singlet-prime flavon is introduced. In this model, non-zero $\theta _{13}$ is given by this additional $A_4$ singlet-prime flavon which breaks tri-bimaximal mixing. In the framework of the supersymmetry with $U(1)_R$ symmetry, we obtain vacuum expectation values (VEVs) and VEV alignments of flavons through driving fields. It is considered that flavon induces distinctive flavor violating process if flavon mass is light. Assuming mass of SUSY particles are sufficiently heavy so that the SUSY contributions can be negligible, we discuss the flavor violating Yukawa interaction through flavon exchange in the charged lepton sector. According to the potential analysis, the VEV of flavon breaks $A_4$ down to $Z_3$ in the charged lepton sector and relation among flavon masses is determined. Thanks for the residual $Z_3$ symmetry, many lepton flavor violating decay modes are forbidden except for $\tau \rightarrow \mu \mu \bar{e}$ and $\tau \rightarrow e e \bar{\mu}$. A mass limit of the flavon from these three-body decay modes is $60$~GeV taking into account the current experimental lower bounds at the Belle experiment. In our model, we predict a ratio of the branching ratios $\tau \rightarrow \mu \mu \bar{e}$ and $\tau \rightarrow e e \bar{\mu}$ by using known charged lepton masses. We also find that the production cross section for the flavon can be $\mathcal{O}(1)$ fb. Thus the flavon would be found at the LHC run 2 by searching for 4-tau lepton signal.
2404.09731
Petja Paakkinen
Kari J. Eskola, Vadim Guzey, Ilkka Helenius, Petja Paakkinen, Hannu Paukkunen
Nuclear spatial resolution in near-encounter UPC dijet photoproduction
12 pages, 10 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present next-to-leading order perturbative QCD predictions for inclusive dijet photoproduction in ultra-peripheral nucleus-nucleus collisions (UPCs) within the impact-parameter dependent equivalent photon approximation. Taking into account the finite size of both the photon-emitting and the target nucleus, we show that this process is sensitive to the transverse-plane geometry of the UPC events. We show that this leads to a sizeable, 20-40% effect for large values of the $z_\gamma$ variable in the dijet photoproduction cross section in lead-lead UPCs at 5.02 TeV compared to the widely-used pointlike approximation where the nuclear radius is accounted only as a sharp cut-off in the photon flux calculation. This resolution of the spatial degrees of freedom is a result of having high-transverse-momentum jets in the final state, which at the large-$z_\gamma$ kinematics requires a highly energetic photon in the initial state, thus biasing the collisions to small impact-parameter ''near-encounter'' configurations. We further discuss the role of the forward-neutron event-class selection in isolating the photonuclear cross section in the nucleus-nucleus collisions, and employ the needed electromagnetic breakup survival factor in our predictions.
[ { "created": "Mon, 15 Apr 2024 12:30:47 GMT", "version": "v1" } ]
2024-04-16
[ [ "Eskola", "Kari J.", "" ], [ "Guzey", "Vadim", "" ], [ "Helenius", "Ilkka", "" ], [ "Paakkinen", "Petja", "" ], [ "Paukkunen", "Hannu", "" ] ]
We present next-to-leading order perturbative QCD predictions for inclusive dijet photoproduction in ultra-peripheral nucleus-nucleus collisions (UPCs) within the impact-parameter dependent equivalent photon approximation. Taking into account the finite size of both the photon-emitting and the target nucleus, we show that this process is sensitive to the transverse-plane geometry of the UPC events. We show that this leads to a sizeable, 20-40% effect for large values of the $z_\gamma$ variable in the dijet photoproduction cross section in lead-lead UPCs at 5.02 TeV compared to the widely-used pointlike approximation where the nuclear radius is accounted only as a sharp cut-off in the photon flux calculation. This resolution of the spatial degrees of freedom is a result of having high-transverse-momentum jets in the final state, which at the large-$z_\gamma$ kinematics requires a highly energetic photon in the initial state, thus biasing the collisions to small impact-parameter ''near-encounter'' configurations. We further discuss the role of the forward-neutron event-class selection in isolating the photonuclear cross section in the nucleus-nucleus collisions, and employ the needed electromagnetic breakup survival factor in our predictions.
0811.0550
Aurore Courtoy
A. Courtoy, S. Noguera
Enhancement effects in exclusive $\pi\pi$ and $\rho\pi$ production in $\gamma^{\ast}\gamma$ scattering
Corrected typos, version accepted for publication in Phys. Lett. B
null
10.1016/j.physletb.2009.03.070
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The exclusive $\pi\pi$ and $\rho\pi$ production in hard $\gamma^{\ast}\gamma$ scattering in the forward kinematical region where the virtual photon is highly off-shell is studied using the $\gamma\to\pi^-$ Transition Distribution Amplitudes obtained in realistic models for the pion. For $\rho\pi$ production we confirm the previous estimates before QCD evolution. Nevertheless, once evolution is taken into account this cross section grows one order of magnitude. In the case of $\pi\pi$ production we have evaluated the cross section including the pion pole contribution. We observe that this contribution is responsible for an enhancement of two orders of magnitude with respect to the cross section evaluated without the pion pole term.
[ { "created": "Tue, 4 Nov 2008 16:31:26 GMT", "version": "v1" }, { "created": "Fri, 3 Apr 2009 09:17:17 GMT", "version": "v2" } ]
2015-05-13
[ [ "Courtoy", "A.", "" ], [ "Noguera", "S.", "" ] ]
The exclusive $\pi\pi$ and $\rho\pi$ production in hard $\gamma^{\ast}\gamma$ scattering in the forward kinematical region where the virtual photon is highly off-shell is studied using the $\gamma\to\pi^-$ Transition Distribution Amplitudes obtained in realistic models for the pion. For $\rho\pi$ production we confirm the previous estimates before QCD evolution. Nevertheless, once evolution is taken into account this cross section grows one order of magnitude. In the case of $\pi\pi$ production we have evaluated the cross section including the pion pole contribution. We observe that this contribution is responsible for an enhancement of two orders of magnitude with respect to the cross section evaluated without the pion pole term.
1001.1335
Ted Barnes
T.Barnes (1 and 2), Xiaoguang Li (2), W.Roberts (3) ((1) Physics Division, Oak Ridge National Laboratory, (2) Department of Physics and Astronomy, University of Tennessee, (3) Department of Physics and Astronomy, Florida State University)
Meson Emission Model of Psi to N Nbar m Charmonium Strong Decays
10 pages, 5 figures
Phys.Rev.D81:034025,2010
10.1103/PhysRevD.81.034025
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we consider a sequential "meson emission" mechanism for charmonium decays of the type Psi -> N Nbar m, where Psi is a generic charmonium state, N is a nucleon and m is a light meson. This decay mechanism, which may not be dominant in general, assumes that an NNbar pair is created during charmonium annihilation, and the light meson m is emitted from the outgoing nucleon or antinucleon line. A straightforward generalization of this model can incorporate intermediate N* resonances. We derive Dalitz plot event densities for the cases Psi = eta_c, J/psi, chi_c0, chi_c1} and psi' and m = pi0, f0 and omega (and implicitly, any 0^{-+}, 0^{++} or 1^{--} final light meson). It may be possible to separate the contribution of this decay mechanism to the full decay amplitude through characteristic event densities. For the decay subset Psi -> p pbar pi0 the two model parameters are known, so we are able to predict absolute numerical partial widths for Gamma(Psi -> p pbar pi0). In the specific case J/psi -> p pbar pi0 the predicted partial width and M_{p pi0} event distribution are intriguingly close to experiment. We also consider the possibility of scalar meson and glueball searches in Psi -> p pbar f0. If the meson emission contributions to Psi -> N Nbar m decays can be isolated and quantified, they can be used to estimate meson-nucleon strong couplings {g_NNm}, which are typically poorly known, and are a crucial input in meson exchange models of the NN interaction. The determination of g_NNpi from J\psi -> p pbar pi0 and the (poorly known) g_NNomega and the anomalous "strong magnetic" coupling kappa_{NNomega} from J/psi -> p pbar omega are considered as examples.
[ { "created": "Fri, 8 Jan 2010 18:47:55 GMT", "version": "v1" }, { "created": "Thu, 28 Jan 2010 16:15:20 GMT", "version": "v2" } ]
2010-05-28
[ [ "Barnes", "T.", "", "1 and 2" ], [ "Li", "Xiaoguang", "" ], [ "Roberts", "W.", "" ] ]
In this paper we consider a sequential "meson emission" mechanism for charmonium decays of the type Psi -> N Nbar m, where Psi is a generic charmonium state, N is a nucleon and m is a light meson. This decay mechanism, which may not be dominant in general, assumes that an NNbar pair is created during charmonium annihilation, and the light meson m is emitted from the outgoing nucleon or antinucleon line. A straightforward generalization of this model can incorporate intermediate N* resonances. We derive Dalitz plot event densities for the cases Psi = eta_c, J/psi, chi_c0, chi_c1} and psi' and m = pi0, f0 and omega (and implicitly, any 0^{-+}, 0^{++} or 1^{--} final light meson). It may be possible to separate the contribution of this decay mechanism to the full decay amplitude through characteristic event densities. For the decay subset Psi -> p pbar pi0 the two model parameters are known, so we are able to predict absolute numerical partial widths for Gamma(Psi -> p pbar pi0). In the specific case J/psi -> p pbar pi0 the predicted partial width and M_{p pi0} event distribution are intriguingly close to experiment. We also consider the possibility of scalar meson and glueball searches in Psi -> p pbar f0. If the meson emission contributions to Psi -> N Nbar m decays can be isolated and quantified, they can be used to estimate meson-nucleon strong couplings {g_NNm}, which are typically poorly known, and are a crucial input in meson exchange models of the NN interaction. The determination of g_NNpi from J\psi -> p pbar pi0 and the (poorly known) g_NNomega and the anomalous "strong magnetic" coupling kappa_{NNomega} from J/psi -> p pbar omega are considered as examples.
hep-ph/0104116
Chi-Sing Lam
C.S. Lam
A 2-3 Symmetry in Neutrino Oscillations
to appear in Phys. Lett. B
Phys.Lett. B507 (2001) 214-218
10.1016/S0370-2693(01)00465-8
null
hep-ph
null
Maximum mixing in atmospheric neutrino oscillation, as well as vanishing of the MNS matrix element $U_{e3}$, are consequences of a 2-3 symmetry, under which the neutrino mass matrix is invariant under the interchange of second and third generation neutrinos. These predictions of the 2-3 symmetry are consistent with the results of Super-Kamiokande, K2K, and CHOOZ experiments. If the symmetry is exact at a high-energy scale set by right-handed neutrinos, a deviation from these predictions generated by renormalization-group corrections will occur at experimental energies. With an MSSM dynamics, the result can be made to agree with a global fit of the neutrino data, if normal hierarchy is assumed on the neutrino mass spectrum and if the mass of the electron-neutrino is at least about 0.025 eV. The presence of this mass lower bound is a novel and interesting feature of the symmetry that can be falsified by future experiments. Of the three viable solar neutrino solutions, only LMA gives a sizable MNS matrix element $U_{e3}$ that can hopefully be detected in future reactor experiments. Inverted neutrino mass hierarchy is not permitted by this symmetry.
[ { "created": "Wed, 11 Apr 2001 17:38:38 GMT", "version": "v1" } ]
2009-11-07
[ [ "Lam", "C. S.", "" ] ]
Maximum mixing in atmospheric neutrino oscillation, as well as vanishing of the MNS matrix element $U_{e3}$, are consequences of a 2-3 symmetry, under which the neutrino mass matrix is invariant under the interchange of second and third generation neutrinos. These predictions of the 2-3 symmetry are consistent with the results of Super-Kamiokande, K2K, and CHOOZ experiments. If the symmetry is exact at a high-energy scale set by right-handed neutrinos, a deviation from these predictions generated by renormalization-group corrections will occur at experimental energies. With an MSSM dynamics, the result can be made to agree with a global fit of the neutrino data, if normal hierarchy is assumed on the neutrino mass spectrum and if the mass of the electron-neutrino is at least about 0.025 eV. The presence of this mass lower bound is a novel and interesting feature of the symmetry that can be falsified by future experiments. Of the three viable solar neutrino solutions, only LMA gives a sizable MNS matrix element $U_{e3}$ that can hopefully be detected in future reactor experiments. Inverted neutrino mass hierarchy is not permitted by this symmetry.
hep-ph/0603116
Koichi Yoshioka
Naoyuki Haba, Atsushi Watanabe and Koichi Yoshioka
Twisted Flavors and Tri/bi-Maximal Neutrino Mixing
11 pages
Phys.Rev.Lett. 97 (2006) 041601
10.1103/PhysRevLett.97.041601
TUM-HEP-621/06, KYUSHU-HET-93
hep-ph
null
A new framework for handling flavor symmetry breaking in the neutrino sector is discussed where the source of symmetry breaking is traced to the global property of right-handed neutrinos in extra-dimensional space. Light neutrino phenomenology has rich and robust predictions such as the tri/bi-maximal form of generation mixing, controlled mass spectrum, and no need of flavor mixing couplings in the theory.
[ { "created": "Wed, 15 Mar 2006 19:08:48 GMT", "version": "v1" } ]
2009-11-11
[ [ "Haba", "Naoyuki", "" ], [ "Watanabe", "Atsushi", "" ], [ "Yoshioka", "Koichi", "" ] ]
A new framework for handling flavor symmetry breaking in the neutrino sector is discussed where the source of symmetry breaking is traced to the global property of right-handed neutrinos in extra-dimensional space. Light neutrino phenomenology has rich and robust predictions such as the tri/bi-maximal form of generation mixing, controlled mass spectrum, and no need of flavor mixing couplings in the theory.
1205.5194
Ali N. Khorramian
H. Khanpour, Ali N. Khorramian, S. Atashbar Tehrani
New parton distributions in fixed flavour factorization scheme from recent deep-inelastic-scattering data
23 pages, 26 figures and 4 tables. V3: Only few comments and references added in the replaced version, results unchanged. Code can be found at http://particles.ipm.ir/links/QCD.htm
null
10.1088/0954-3899/40/4/045002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present our QCD analysis of the proton structure function $F_2^p(x,Q^2)$ to determine the parton distributions at the next-to-leading order (NLO). The heavy quark contributions to $F_2^i(x,Q^2)$, with $i$ = $c$, $b$ have been included in the framework of the `fixed flavour number scheme' (FFNS). The results obtained in the FFNS are compared with available results such as the general-mass variable-flavour-number scheme (GM-VFNS) and other prescriptions used in global fits of PDFs. In the present QCD analysis, we use a wide range of the inclusive neutral-current deep-inelastic-scattering (NC DIS) data, including the most recent data for charm $F_2^c$, bottom $F_2^b$, longitudinal $F_L$ structure functions and also the reduced DIS cross sections $\sigma_{r,NC}^\pm$ from HERA experiments. The most recent HERMES data for proton and deuteron structure functions are also added. We take into account ZEUS neutral current $e^ \pm p$ DIS inclusive jet cross section data from HERA together with the recent Tevatron Run-II inclusive jet cross section data from CDF and D{\O}. The impact of these recent DIS data on the PDFs extracted from the global fits are studied. We present two families of PDFs, {\tt KKT12} and {\tt KKT12C}, without and with HERA `combined' data sets on $e^{\pm}p$ DIS. We find these are in good agreement with the available theoretical models.
[ { "created": "Wed, 23 May 2012 14:55:47 GMT", "version": "v1" }, { "created": "Fri, 20 Jul 2012 10:16:32 GMT", "version": "v2" }, { "created": "Mon, 30 Jul 2012 10:20:12 GMT", "version": "v3" } ]
2015-06-05
[ [ "Khanpour", "H.", "" ], [ "Khorramian", "Ali N.", "" ], [ "Tehrani", "S. Atashbar", "" ] ]
We present our QCD analysis of the proton structure function $F_2^p(x,Q^2)$ to determine the parton distributions at the next-to-leading order (NLO). The heavy quark contributions to $F_2^i(x,Q^2)$, with $i$ = $c$, $b$ have been included in the framework of the `fixed flavour number scheme' (FFNS). The results obtained in the FFNS are compared with available results such as the general-mass variable-flavour-number scheme (GM-VFNS) and other prescriptions used in global fits of PDFs. In the present QCD analysis, we use a wide range of the inclusive neutral-current deep-inelastic-scattering (NC DIS) data, including the most recent data for charm $F_2^c$, bottom $F_2^b$, longitudinal $F_L$ structure functions and also the reduced DIS cross sections $\sigma_{r,NC}^\pm$ from HERA experiments. The most recent HERMES data for proton and deuteron structure functions are also added. We take into account ZEUS neutral current $e^ \pm p$ DIS inclusive jet cross section data from HERA together with the recent Tevatron Run-II inclusive jet cross section data from CDF and D{\O}. The impact of these recent DIS data on the PDFs extracted from the global fits are studied. We present two families of PDFs, {\tt KKT12} and {\tt KKT12C}, without and with HERA `combined' data sets on $e^{\pm}p$ DIS. We find these are in good agreement with the available theoretical models.
hep-ph/9207207
Cliff Burgess
C.P. Burgess and James M. Cline
Majorons from Double Beta Decay
5 pages, McGill/92-27
null
null
null
hep-ph
null
Wrong preprint number changed on previous version.
[ { "created": "Thu, 2 Jul 1992 21:02:58 GMT", "version": "v1" }, { "created": "Sat, 29 Aug 1992 14:21:50 GMT", "version": "v2" }, { "created": "Tue, 29 Sep 1992 14:41:11 GMT", "version": "v3" }, { "created": "Wed, 30 Sep 1992 21:40:36 GMT", "version": "v4" } ]
2008-02-03
[ [ "Burgess", "C. P.", "" ], [ "Cline", "James M.", "" ] ]
Wrong preprint number changed on previous version.
2311.09894
Andrey Grozin
Andrey Grozin
Anomalous dimension of the heavy-light quark current in HQET up to four loops
12 pages, no figures; v2: some info on $1/m$ corrections included, 5 new references; v3: some info on the large $\beta_0$ limit and summing divergent perturbative series included, very slight changes of some numbers, 8 new references
JHEP 02 (2024) 198
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The anomalous dimension of the heavy-light quark current in HQET is calculated up to four loops. The N$^3$LL perturbative correction to $f_B/f_D$ is obtained.
[ { "created": "Thu, 16 Nov 2023 13:43:56 GMT", "version": "v1" }, { "created": "Thu, 7 Dec 2023 14:48:49 GMT", "version": "v2" }, { "created": "Fri, 26 Jan 2024 15:04:34 GMT", "version": "v3" } ]
2024-02-29
[ [ "Grozin", "Andrey", "" ] ]
The anomalous dimension of the heavy-light quark current in HQET is calculated up to four loops. The N$^3$LL perturbative correction to $f_B/f_D$ is obtained.
2101.08789
Sebastian Hoof
Sebastian Hoof, Joerg Jaeckel, Lennert J. Thormaehlen
Quantifying uncertainties in the solar axion flux and their impact on determining axion model parameters
35 + 10 pages, 12 figures. V3 includes extended discussions and an additional appendix on the Primakoff form factor correction; matches the published version. Code available at https://github.com/sebhoof/SolarAxionFlux
JCAP 09(2021)006
10.1088/1475-7516/2021/09/006
null
hep-ph astro-ph.SR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the calculation of the solar axion flux from axion-photon and axion-electron interactions and discuss the size of various effects neglected in current calculations. For the Primakoff flux we then explicitly include the partial degeneracy of electrons. We survey the available solar models and opacity codes and develop a publicly available C++/Python code to quantify the associated systematic differences and statistical uncertainties. The number of axions emitted in helioseismological solar models is systematically larger by about 5% compared to photospheric models, while the overall statistical uncertainties in solar models are typically at the percent level in both helioseismological and photospheric models. However, for specific energies, the statistical fluctuations can reach up to about 5% as well. Taking these uncertainties into account, we investigate the ability of the upcoming helioscope IAXO to discriminate KSVZ axion models. Such a discrimination is possible for a number of models, and a discovery of KSVZ axions with high $E/N$ ratios could potentially help to solve the solar abundance problem. We discuss limitations of the axion emission calculations and identify potential improvements, which would help to determine axion model parameters more accurately.
[ { "created": "Thu, 21 Jan 2021 19:00:01 GMT", "version": "v1" }, { "created": "Thu, 6 May 2021 12:09:59 GMT", "version": "v2" }, { "created": "Wed, 8 Sep 2021 08:54:19 GMT", "version": "v3" } ]
2021-09-09
[ [ "Hoof", "Sebastian", "" ], [ "Jaeckel", "Joerg", "" ], [ "Thormaehlen", "Lennert J.", "" ] ]
We review the calculation of the solar axion flux from axion-photon and axion-electron interactions and discuss the size of various effects neglected in current calculations. For the Primakoff flux we then explicitly include the partial degeneracy of electrons. We survey the available solar models and opacity codes and develop a publicly available C++/Python code to quantify the associated systematic differences and statistical uncertainties. The number of axions emitted in helioseismological solar models is systematically larger by about 5% compared to photospheric models, while the overall statistical uncertainties in solar models are typically at the percent level in both helioseismological and photospheric models. However, for specific energies, the statistical fluctuations can reach up to about 5% as well. Taking these uncertainties into account, we investigate the ability of the upcoming helioscope IAXO to discriminate KSVZ axion models. Such a discrimination is possible for a number of models, and a discovery of KSVZ axions with high $E/N$ ratios could potentially help to solve the solar abundance problem. We discuss limitations of the axion emission calculations and identify potential improvements, which would help to determine axion model parameters more accurately.