id stringlengths 9 14 | submitter stringlengths 1 56 ⌀ | authors stringlengths 5 7.68k | title stringlengths 3 299 | comments stringlengths 1 1.15k ⌀ | journal-ref stringlengths 9 298 ⌀ | doi stringlengths 12 97 ⌀ | report-no stringlengths 3 341 ⌀ | categories stringclasses 869 values | license stringclasses 9 values | orig_abstract stringlengths 16 2.44k | versions listlengths 1 39 | update_date stringlengths 10 10 | authors_parsed listlengths 1 565 | abstract stringlengths 13 2.44k |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
hep-ph/9903401 | Alexander Ya. Parkhomenko | N.V. Mikheev, A.Ya. Parkhomenko and L.A. Vassilevskaya (Yaroslavl
State (Demidov) University, Russia) | Axion Decay of a Photon in an External Electromagnetic Field | 7 pages, latex, 1 PS figure | Mod.Phys.Lett. A13 (1998) 1899-1905 | 10.1142/S021773239800200X | YARU-HE-98/11 | hep-ph | null | An interaction of a pseudoscalar particle with two photons induced by an
external electromagnetic field is used to study the photon decay $\gamma \to
\gamma a$ where a is a pseudoscalar particle associated with the Peccei-Quinn
U(1) symmetry. The field-induced axion emission by photon is analyzed as a
possible source of energy losses by astrophysical objects.
| [
{
"created": "Thu, 18 Mar 1999 14:22:45 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Mikheev",
"N. V.",
"",
"Yaroslavl\n State"
],
[
"Parkhomenko",
"A. Ya.",
"",
"Yaroslavl\n State"
],
[
"Vassilevskaya",
"L. A.",
"",
"Yaroslavl\n State"
]
] | An interaction of a pseudoscalar particle with two photons induced by an external electromagnetic field is used to study the photon decay $\gamma \to \gamma a$ where a is a pseudoscalar particle associated with the Peccei-Quinn U(1) symmetry. The field-induced axion emission by photon is analyzed as a possible source of energy losses by astrophysical objects. |
1403.7684 | Nikolaos Mavromatos | Nick E. Mavromatos | Pseudoscalar Fields in Torsionful Geometries of the Early Universe, the
Baryon Asymmetry and Majorana Neutrino Mass Generation | 14 pages bibtex, one eps figure incorporated, uses special macros;
Invited plenary talk at XIV Mexican Workshop on Particles and Fields,
November 25-29 2013, Oaxaca (Mexico) | null | null | LCTS/2014-03, KCL-PH-TH/2014-03 | hep-ph gr-qc hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss here a specific field-theory model, inspired from string theory,
in which the generation of a matter-antimatter asymmetry in the Cosmos is due
to the propagation of fermions in a non-trivial, spherically asymmetric (and
hence Lorentz violating) gravitational background that may characterise the
epochs of the early universe. The background induces different dispersion
relations, hence populations, between fermions and antifermions, and thus CPT
Violation (CPTV) already in thermal equilibrium. Species populations may freeze
out leading to leptogenesis and baryogenesis. More specifically, after
reviewing some generic models of background-induced CPTV in early epochs of the
Universe, we consider a string-inspired scenario, in which the CPTV is
associated with a cosmological background with torsion provided by the
Kalb-Ramond (KR) antisymemtric tensor field of the string gravitational
multiplet. In a four-dimensional space time this field is dual to a
pseudoscalar ``axion-like'' field. The thermalising processes in this model are
(right-handed) Majorana neutrino-antineutrino oscillations, which are induced
in the presence of the KR axion background. These processes freeze out at a
(high) temperature $T_c >> m$, where $m$ is the Majorana neutrino mass, at
which the KR background goes to zero or is diminished significantly, through
appropriate phase transitions of the (string) universe. An additional, but
equally important, r\^ole, of the KR field is that its quantum fluctuations and
mixing with an ordinary axion, which couples to the Majorana neutrinos via
appropriate Yukawa couplings, can also lead to the generation of a Majorana
neutrino mass through quantum anomalies. This provides a novel way for
generating neutrino masses, independent of the traditional seesaw mechanism.
| [
{
"created": "Sun, 30 Mar 2014 00:38:28 GMT",
"version": "v1"
}
] | 2014-04-01 | [
[
"Mavromatos",
"Nick E.",
""
]
] | We discuss here a specific field-theory model, inspired from string theory, in which the generation of a matter-antimatter asymmetry in the Cosmos is due to the propagation of fermions in a non-trivial, spherically asymmetric (and hence Lorentz violating) gravitational background that may characterise the epochs of the early universe. The background induces different dispersion relations, hence populations, between fermions and antifermions, and thus CPT Violation (CPTV) already in thermal equilibrium. Species populations may freeze out leading to leptogenesis and baryogenesis. More specifically, after reviewing some generic models of background-induced CPTV in early epochs of the Universe, we consider a string-inspired scenario, in which the CPTV is associated with a cosmological background with torsion provided by the Kalb-Ramond (KR) antisymemtric tensor field of the string gravitational multiplet. In a four-dimensional space time this field is dual to a pseudoscalar ``axion-like'' field. The thermalising processes in this model are (right-handed) Majorana neutrino-antineutrino oscillations, which are induced in the presence of the KR axion background. These processes freeze out at a (high) temperature $T_c >> m$, where $m$ is the Majorana neutrino mass, at which the KR background goes to zero or is diminished significantly, through appropriate phase transitions of the (string) universe. An additional, but equally important, r\^ole, of the KR field is that its quantum fluctuations and mixing with an ordinary axion, which couples to the Majorana neutrinos via appropriate Yukawa couplings, can also lead to the generation of a Majorana neutrino mass through quantum anomalies. This provides a novel way for generating neutrino masses, independent of the traditional seesaw mechanism. |
1309.7342 | Shufang Su | Mikael Berggren (DESY), Tao Han (University of Pittsburgh), Jenny List
(DESY), Sanjay Padhi (University of California, San Diego), Shufang Su
(University of Arizona), Tomohiko Tanabe (University of Tokyo) | Electroweakino Searches: A Comparative Study for LHC and ILC (A Snowmass
White Paper) | 12 pages, 3 figures | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We make a systematic and comparative study for the LHC and ILC for the
electroweakino searches in the Minimal Supersymmetric Standard Model. We adopt
a general bottom-up approach and scan over the parameter regions for all the
three cases of the lightest supersymmetric particle being Bino-, Wino-, and
Higgsino-like. The electroweakino signal from pair production and subsequent
decay to Wh (h to b\bar b) final state may yield a sensitivity of 95% C.L.
exclusion (5sigma discovery) to the mass scale M_2, mu ~ 250-400 GeV (200-250
GeV) at the 14 TeV LHC with an luminosity of 300 fb^{-1}. Combining with all
the other decay channels, the 95% C.L. exclusion (5sigma discovery) may be
extended to M_2, mu ~ 480-700 GeV (320-500 GeV). At the ILC, the
electroweakinos could be readily discovered once the kinematical threshold is
crossed, and their properties could be thoroughly studied.
| [
{
"created": "Fri, 27 Sep 2013 19:53:36 GMT",
"version": "v1"
}
] | 2013-10-01 | [
[
"Berggren",
"Mikael",
"",
"DESY"
],
[
"Han",
"Tao",
"",
"University of Pittsburgh"
],
[
"List",
"Jenny",
"",
"DESY"
],
[
"Padhi",
"Sanjay",
"",
"University of California, San Diego"
],
[
"Su",
"Shufang",
"",
"Universit... | We make a systematic and comparative study for the LHC and ILC for the electroweakino searches in the Minimal Supersymmetric Standard Model. We adopt a general bottom-up approach and scan over the parameter regions for all the three cases of the lightest supersymmetric particle being Bino-, Wino-, and Higgsino-like. The electroweakino signal from pair production and subsequent decay to Wh (h to b\bar b) final state may yield a sensitivity of 95% C.L. exclusion (5sigma discovery) to the mass scale M_2, mu ~ 250-400 GeV (200-250 GeV) at the 14 TeV LHC with an luminosity of 300 fb^{-1}. Combining with all the other decay channels, the 95% C.L. exclusion (5sigma discovery) may be extended to M_2, mu ~ 480-700 GeV (320-500 GeV). At the ILC, the electroweakinos could be readily discovered once the kinematical threshold is crossed, and their properties could be thoroughly studied. |
1003.2644 | Ted Barnes | T.Barnes (1 and 2) ((1) Physics Division, ORNL, Oak Ridge, TN (2)
Dept. of Physics and Astronomy, University of Tennessee, Knoxville, TN) | Update on Charmonium Theory | 8 pp., 3 figures. Invited contribution to HADRON 2009 (XIIIth
Internatl. Conf. on Hadron Spectroscopy, Tallahassee, FL, Nov.29 - Dec.4
2009). | null | 10.1063/1.3483307 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this invited presentation I review some recent developments in the theory
of charmonium that appear likely to be of importance for future experimental
studies in this field. The specific areas considered are double charmonium
production, LQCD studies of charmonium, recent results for hadron loops, c-cbar
production cross sections at PANDA, charm molecules, and two recent
developments, "charmiscelleny".
| [
{
"created": "Fri, 12 Mar 2010 21:37:25 GMT",
"version": "v1"
}
] | 2015-05-18 | [
[
"Barnes",
"T.",
"",
"1 and 2"
]
] | In this invited presentation I review some recent developments in the theory of charmonium that appear likely to be of importance for future experimental studies in this field. The specific areas considered are double charmonium production, LQCD studies of charmonium, recent results for hadron loops, c-cbar production cross sections at PANDA, charm molecules, and two recent developments, "charmiscelleny". |
hep-ph/0205190 | Fis. Teorica. Valladolid. | Francisco J. Herranz | New quantum (anti)de Sitter algebras and discrete symmetries | 10 pages, LaTeX | Phys.Lett. B543 (2002) 89-97 | 10.1016/S0370-2693(02)02452-8 | null | hep-ph hep-th math.QA | null | Two new quantum anti-de Sitter so(4,2) and de Sitter so(5,1) algebras are
presented. These deformations are called either time-type or space-type
according to the dimensional properties of the deformation parameter. Their
Hopf structure, universal R matrix and differential-difference realization are
obtained in a unified setting by considering a contraction parameter related to
the speed of light, which ensures a well defined non-relativistic limit. Such
quantum algebras are shown to be symmetry algebras of either time or space
discretizations of wave/Laplace equations on uniform lattices. These results
lead to a proposal fortime and space discrete Maxwell equations with quantum
algebra symmetry.
| [
{
"created": "Fri, 17 May 2002 10:59:17 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Herranz",
"Francisco J.",
""
]
] | Two new quantum anti-de Sitter so(4,2) and de Sitter so(5,1) algebras are presented. These deformations are called either time-type or space-type according to the dimensional properties of the deformation parameter. Their Hopf structure, universal R matrix and differential-difference realization are obtained in a unified setting by considering a contraction parameter related to the speed of light, which ensures a well defined non-relativistic limit. Such quantum algebras are shown to be symmetry algebras of either time or space discretizations of wave/Laplace equations on uniform lattices. These results lead to a proposal fortime and space discrete Maxwell equations with quantum algebra symmetry. |
hep-ph/9605436 | Dominique Toublan | G. Wanders (University of Lausanne) | Determination of the chiral pion-pion scattering parameters: a proposal | 14 pages plain latex, 2 figures, uuencoded, tarred and compressed | Helv.Phys.Acta 70 (1997) 287-301 | null | null | hep-ph | null | An explicitly crossing-symmetric decomposition of the pion-pion scattering
amplitudes into low- and high-energy components is established. The high-energy
components are entirely determined by absorptive parts at high energies. With
the exception of the two leading-order parameters, all the parameters appearing
in the one- and two-loop chiral amplitudes are determined by the high-energy
components of the exact amplitudes.
| [
{
"created": "Thu, 30 May 1996 11:14:58 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Wanders",
"G.",
"",
"University of Lausanne"
]
] | An explicitly crossing-symmetric decomposition of the pion-pion scattering amplitudes into low- and high-energy components is established. The high-energy components are entirely determined by absorptive parts at high energies. With the exception of the two leading-order parameters, all the parameters appearing in the one- and two-loop chiral amplitudes are determined by the high-energy components of the exact amplitudes. |
1011.2397 | Carl E. Carlson | Benjamin C. Rislow and Carl E. Carlson (William and Mary, and
Helmholtz Institute, Johannes Gutenberg University, Mainz) | Gamma-Z box contributions to parity violating elastic e-p scattering | 4 pages, 4 figures, v2: reference added, typo fixed | Phys.Rev.D83:113007,2011 | 10.1103/PhysRevD.83.113007 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Parity-violating (PV) elastic electron-proton scattering measures Q-weak for
the proton, $Q_W^p$. To extract $Q_W^p$ from data, all radiative corrections
must be well-known. Recently, disagreement on the gamma-Z box contribution to
$Q_W^p$ has prompted the need for further analysis of this term. Here, we
support one choice of a debated factor, go beyond the previously assumed
equality of electromagnetic and gamma-Z structure functions, and find an
analytic result for one of the gamma-Z box integrals. Our numerical evaluation
of the gamma-Z box is in agreement within errors with previous reports, albeit
somewhat larger in central value, and is within the uncertainty requirements of
current experiments.
| [
{
"created": "Wed, 10 Nov 2010 15:01:21 GMT",
"version": "v1"
},
{
"created": "Mon, 15 Nov 2010 13:10:27 GMT",
"version": "v2"
}
] | 2011-07-04 | [
[
"Rislow",
"Benjamin C.",
"",
"William and Mary, and\n Helmholtz Institute, Johannes Gutenberg University, Mainz"
],
[
"Carlson",
"Carl E.",
"",
"William and Mary, and\n Helmholtz Institute, Johannes Gutenberg University, Mainz"
]
] | Parity-violating (PV) elastic electron-proton scattering measures Q-weak for the proton, $Q_W^p$. To extract $Q_W^p$ from data, all radiative corrections must be well-known. Recently, disagreement on the gamma-Z box contribution to $Q_W^p$ has prompted the need for further analysis of this term. Here, we support one choice of a debated factor, go beyond the previously assumed equality of electromagnetic and gamma-Z structure functions, and find an analytic result for one of the gamma-Z box integrals. Our numerical evaluation of the gamma-Z box is in agreement within errors with previous reports, albeit somewhat larger in central value, and is within the uncertainty requirements of current experiments. |
2002.04822 | Yongchao Zhang | P. S. Bhupal Dev, Werner Rodejohann, Xun-Jie Xu, Yongchao Zhang | MUonE sensitivity to new physics explanations of the muon anomalous
magnetic moment | 30 pages, 12 figures, minor corrections and changes, more references,
version to appear in JHEP | JHEP 05 (2020), 053 | 10.1007/JHEP05(2020)053 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The MUonE experiment aims at a precision measurement of the hadronic vacuum
polarization contribution to the muon $g-2$, via elastic muon-electron
scattering. Since the current muon $g-2$ anomaly hints at the potential
existence of new physics (NP) related to the muon, the question then arises as
to whether the measurement of hadronic vacuum polarization in MUonE could be
affected by the same NP as well. In this work, we address this question by
investigating a variety of NP explanations of the muon $g-2$ anomaly via either
vector or scalar mediators with either flavor-universal, non-universal or even
flavor-violating couplings to electrons and muons. We derive the corresponding
MUonE sensitivity in each case and find that the measurement of hadronic vacuum
polarization at the MUonE is not vulnerable to any of these NP scenarios.
| [
{
"created": "Wed, 12 Feb 2020 07:11:02 GMT",
"version": "v1"
},
{
"created": "Fri, 8 May 2020 17:17:01 GMT",
"version": "v2"
}
] | 2020-05-14 | [
[
"Dev",
"P. S. Bhupal",
""
],
[
"Rodejohann",
"Werner",
""
],
[
"Xu",
"Xun-Jie",
""
],
[
"Zhang",
"Yongchao",
""
]
] | The MUonE experiment aims at a precision measurement of the hadronic vacuum polarization contribution to the muon $g-2$, via elastic muon-electron scattering. Since the current muon $g-2$ anomaly hints at the potential existence of new physics (NP) related to the muon, the question then arises as to whether the measurement of hadronic vacuum polarization in MUonE could be affected by the same NP as well. In this work, we address this question by investigating a variety of NP explanations of the muon $g-2$ anomaly via either vector or scalar mediators with either flavor-universal, non-universal or even flavor-violating couplings to electrons and muons. We derive the corresponding MUonE sensitivity in each case and find that the measurement of hadronic vacuum polarization at the MUonE is not vulnerable to any of these NP scenarios. |
hep-ph/9904449 | null | Hsiang-nan Li | Perturbative QCD analysis of b-hadron lifetimes | 18 pages in revtex, 1 figure in postscript file | null | null | NCKU-HEP-99-05 | hep-ph | null | We develop perturbative QCD factorization theorems for inclusive b-hadron
decays, in which radiative corrections characterized by the hadronic scale, the
b-hadron mass, and the W boson mass are absorbed into a heavy hadron
distribution function, a hard b quark decay amplitude, and a "harder" function,
respectively. Double logarithmic corrections associated with a light energetic
final-state quark, which appear at kinematic end points, are absorbed into a
jet function. Various large logarithms contained in the above functions are
summed to all orders, leading to the evolution factors among the three
characteristic scales. The heavy hadron distribution function is identical to
the one constructed in the framework of heavy quark effective theory. It is
shown that hadron kinematics must be employed in factorization theorems, and
that perturbative contributions, depending on hadron kinematics, distinguish
the lifetimes of the b-hadrons $B_d, B_s$ and $\Lambda_b$. Assuming the same
heavy-quark-effective-theory parametesr $\lambda_1$ for these hadrons, we
predict the lifetimes $\tau(B_d)=1.56$ ps, $\tau(B_s)=1.46$ ps and
$\tau(\Lambda_b)=1.22$ ps. We also predict the $B_u$ meson lifetime
$\tau(B_u)=1.62$ ps by varying the B meson distribution function slightly. All
the above results are consistent with experimental data.
| [
{
"created": "Mon, 26 Apr 1999 08:45:22 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Li",
"Hsiang-nan",
""
]
] | We develop perturbative QCD factorization theorems for inclusive b-hadron decays, in which radiative corrections characterized by the hadronic scale, the b-hadron mass, and the W boson mass are absorbed into a heavy hadron distribution function, a hard b quark decay amplitude, and a "harder" function, respectively. Double logarithmic corrections associated with a light energetic final-state quark, which appear at kinematic end points, are absorbed into a jet function. Various large logarithms contained in the above functions are summed to all orders, leading to the evolution factors among the three characteristic scales. The heavy hadron distribution function is identical to the one constructed in the framework of heavy quark effective theory. It is shown that hadron kinematics must be employed in factorization theorems, and that perturbative contributions, depending on hadron kinematics, distinguish the lifetimes of the b-hadrons $B_d, B_s$ and $\Lambda_b$. Assuming the same heavy-quark-effective-theory parametesr $\lambda_1$ for these hadrons, we predict the lifetimes $\tau(B_d)=1.56$ ps, $\tau(B_s)=1.46$ ps and $\tau(\Lambda_b)=1.22$ ps. We also predict the $B_u$ meson lifetime $\tau(B_u)=1.62$ ps by varying the B meson distribution function slightly. All the above results are consistent with experimental data. |
hep-ph/0703177 | David McKeen | David McKeen, Jonathan L. Rosner, Arun M. Thalapillil | Masses and Mixings in a Grand Unified Toy Model | 21 pages, 2 figures, RevTeX, v2: references updated and typos
corrected, v3: updated top quark mass, comments on MiniBooNE result, and
typos corrected | Phys.Rev.D76:073014,2007 | 10.1103/PhysRevD.76.073014 | EFI 07-07 | hep-ph | null | The generation of the fermion mass hierarchy in the standard model of
particle physics is a long-standing puzzle. The recent discoveries from
neutrino physics suggests that the mixing in the lepton sector is large
compared to the quark mixings. To understand this asymmetry between the quark
and lepton mixings is an important aim for particle physics. In this regard,
two promising approaches from the theoretical side are grand unified theories
and family symmetries. In this note we try to understand certain general
features of grand unified theories with Abelian family symmetries by taking the
simplest SU(5) grand unified theory as a prototype. We construct an SU(5) toy
model with $U(1)_F \otimes Z'_2\otimes Z''_2 \otimes Z'''_2$ family symmetry
that, in a natural way, duplicates the observed mass hierarchy and mixing
matrices to lowest approximation. The system for generating the mass hierarchy
is through a Froggatt-Nielsen type mechanism. One idea that we use in the model
is that the quark and charged lepton sectors are hierarchical with small mixing
angles while the light neutrino sector is democratic with larger mixing angles.
We also discuss some of the difficulties in incorporating finer details into
the model without making further assumptions or adding a large scalar sector.
| [
{
"created": "Fri, 16 Mar 2007 15:04:44 GMT",
"version": "v1"
},
{
"created": "Fri, 6 Apr 2007 21:52:52 GMT",
"version": "v2"
},
{
"created": "Fri, 20 Apr 2007 21:26:38 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"McKeen",
"David",
""
],
[
"Rosner",
"Jonathan L.",
""
],
[
"Thalapillil",
"Arun M.",
""
]
] | The generation of the fermion mass hierarchy in the standard model of particle physics is a long-standing puzzle. The recent discoveries from neutrino physics suggests that the mixing in the lepton sector is large compared to the quark mixings. To understand this asymmetry between the quark and lepton mixings is an important aim for particle physics. In this regard, two promising approaches from the theoretical side are grand unified theories and family symmetries. In this note we try to understand certain general features of grand unified theories with Abelian family symmetries by taking the simplest SU(5) grand unified theory as a prototype. We construct an SU(5) toy model with $U(1)_F \otimes Z'_2\otimes Z''_2 \otimes Z'''_2$ family symmetry that, in a natural way, duplicates the observed mass hierarchy and mixing matrices to lowest approximation. The system for generating the mass hierarchy is through a Froggatt-Nielsen type mechanism. One idea that we use in the model is that the quark and charged lepton sectors are hierarchical with small mixing angles while the light neutrino sector is democratic with larger mixing angles. We also discuss some of the difficulties in incorporating finer details into the model without making further assumptions or adding a large scalar sector. |
hep-ph/9502314 | Andreas Wirzba | Andreas Wirzba (TH Darmstadt), Vesteinn Thorsson (NORDITA) | In-medium effective chiral lagrangians and the pion mass in nuclear
matter | 14 pages, LaTeX, some typographical errors corrected | null | null | IKDA 95/4 | hep-ph nucl-th | null | We argue that the effective pion mass in nuclear matter obtained from chiral
effective lagrangians is unique and does not depend on off-mass-shell
extensions of the pion fields as e.g. the PCAC choice. The effective pion mass
in isospin symmetric nuclear matter is predicted to increase slightly with
increasing nuclear density, whereas the effective time-like pion decay constant
and the magnitude of the density-dependent quark condensate decrease
appreciably. The in-medium Gell-Mann-Oakes-Renner relation as well as other
in-medium identities are studied in addition. Finally, several constraints on
effective lagrangians for the description of the pion propagation in isospin
symmetric, isotropic and homogenous nuclear matter are discussed. (Talk
presented at the workshop ``Hirschegg '95: Hadrons in Nuclear Matter'',
Hirschegg, Kleinwalsertal, Austria, January 16-21, 1995)
| [
{
"created": "Thu, 16 Feb 1995 08:26:00 GMT",
"version": "v1"
},
{
"created": "Mon, 20 Feb 1995 10:11:55 GMT",
"version": "v2"
}
] | 2016-09-01 | [
[
"Wirzba",
"Andreas",
"",
"TH Darmstadt"
],
[
"Thorsson",
"Vesteinn",
"",
"NORDITA"
]
] | We argue that the effective pion mass in nuclear matter obtained from chiral effective lagrangians is unique and does not depend on off-mass-shell extensions of the pion fields as e.g. the PCAC choice. The effective pion mass in isospin symmetric nuclear matter is predicted to increase slightly with increasing nuclear density, whereas the effective time-like pion decay constant and the magnitude of the density-dependent quark condensate decrease appreciably. The in-medium Gell-Mann-Oakes-Renner relation as well as other in-medium identities are studied in addition. Finally, several constraints on effective lagrangians for the description of the pion propagation in isospin symmetric, isotropic and homogenous nuclear matter are discussed. (Talk presented at the workshop ``Hirschegg '95: Hadrons in Nuclear Matter'', Hirschegg, Kleinwalsertal, Austria, January 16-21, 1995) |
1401.2704 | Hai-Bin Zhang | Hai-Bin Zhang, Tai-Fu Feng, Zhao-Feng Ge, Shu-Min Zhao | Transition magnetic moment of Majorana neutrinos in the $\mu\nu$SSM | 20 pages, 2 figures, accepted for publication in JHEP. arXiv admin
note: text overlap with arXiv:1305.4352, arXiv:1304.6248 | JHEP02(2014)012 | 10.1007/JHEP02(2014)012 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The nonzero vacuum expectative values of sneutrinos induce spontaneously
R-parity and lepton number violation, and generate three tiny Majorana neutrino
masses through the seesaw mechanism in the $\mu\nu$SSM, which is one of
Supersymmetric extensions beyond Standard Model. Applying effective Lagrangian
method, we study the transition magnetic moment of Majorana neutrinos in the
model here. Under the constraints from neutrino oscillations, we consider the
two possibilities on the neutrino mass spectrum with normal or inverted
ordering.
| [
{
"created": "Mon, 13 Jan 2014 04:00:55 GMT",
"version": "v1"
}
] | 2014-02-06 | [
[
"Zhang",
"Hai-Bin",
""
],
[
"Feng",
"Tai-Fu",
""
],
[
"Ge",
"Zhao-Feng",
""
],
[
"Zhao",
"Shu-Min",
""
]
] | The nonzero vacuum expectative values of sneutrinos induce spontaneously R-parity and lepton number violation, and generate three tiny Majorana neutrino masses through the seesaw mechanism in the $\mu\nu$SSM, which is one of Supersymmetric extensions beyond Standard Model. Applying effective Lagrangian method, we study the transition magnetic moment of Majorana neutrinos in the model here. Under the constraints from neutrino oscillations, we consider the two possibilities on the neutrino mass spectrum with normal or inverted ordering. |
0804.1546 | Walter Winter | Svenja Niehage, Walter Winter | Entangled maximal mixings in U_PMNS=U_l^dagger U_nu, and a connection to
complex mass textures | 27 pages, 6 tables, 1 figure. Shortened version to appear in Phys.
Rev. D | Phys.Rev.D78:013007,2008 | 10.1103/PhysRevD.78.013007 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss two different configurations of U_PMNS=U_l^dagger U_nu with
maximal mixings in both U_l and U_nu. The non-maximal mixing angles are assumed
to be small, which means that they can be expanded in. Since we are
particularly interested in the implications for CP violation, we fully take
into account complex phases. We demonstrate that one possibility leads to
intrinsically large theta_13 and strong deviations from maximal mixings. The
other possibility is generically close to tri-bimaximal mixing, and allows for
large CP violation. We demonstrate how the determination of the theta_23 octant
and the precision measurement of delta_CP could discriminate among different
qualitative sub-cases. In order to constrain the unphysical and observable
phases even further, we relate our configurations to complex mass matrix
textures. In particular, we focus on phase patterns which could be generated by
powers of a single complex quantity eta=theta_C exp(i Phi), which can be
motivated by Froggatt-Nielsen-like models. For example, it turns out that in
all of the discussed cases, one of the Majorana phases is proportional to Phi
to leading order. In the entire study, we encounter three different classes of
sum rules, which we systematically classify.
| [
{
"created": "Thu, 10 Apr 2008 12:23:52 GMT",
"version": "v1"
},
{
"created": "Fri, 18 Apr 2008 12:21:35 GMT",
"version": "v2"
},
{
"created": "Wed, 18 Jun 2008 09:50:31 GMT",
"version": "v3"
}
] | 2008-12-18 | [
[
"Niehage",
"Svenja",
""
],
[
"Winter",
"Walter",
""
]
] | We discuss two different configurations of U_PMNS=U_l^dagger U_nu with maximal mixings in both U_l and U_nu. The non-maximal mixing angles are assumed to be small, which means that they can be expanded in. Since we are particularly interested in the implications for CP violation, we fully take into account complex phases. We demonstrate that one possibility leads to intrinsically large theta_13 and strong deviations from maximal mixings. The other possibility is generically close to tri-bimaximal mixing, and allows for large CP violation. We demonstrate how the determination of the theta_23 octant and the precision measurement of delta_CP could discriminate among different qualitative sub-cases. In order to constrain the unphysical and observable phases even further, we relate our configurations to complex mass matrix textures. In particular, we focus on phase patterns which could be generated by powers of a single complex quantity eta=theta_C exp(i Phi), which can be motivated by Froggatt-Nielsen-like models. For example, it turns out that in all of the discussed cases, one of the Majorana phases is proportional to Phi to leading order. In the entire study, we encounter three different classes of sum rules, which we systematically classify. |
1905.06957 | Pavel Nadolsky | Karol Kovarik, Pavel M. Nadolsky, Davison E. Soper | Hadron structure in high-energy collisions | 60 pages, 16 figures, published version | Rev. Mod. Phys. 92, 45003 (2020) | 10.1103/RevModPhys.92.045003 | MS-TP-19-09, SMU-HEP-19-05 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Parton distribution functions (PDFs) describe the structure of hadrons as
composed of quarks and gluons. They are needed to make predictions for
short-distance processes in high-energy collisions and are determined by
fitting to cross section data. We review definitions of the PDFs and their
relations to high-energy cross sections. We focus on the PDFs in protons, but
also discuss PDFs in nuclei. We review in some detail the standard statistical
treatment needed to fit the PDFs to data using the Hessian method. We discuss
tests that can be used to critically examine whether the assumptions are indeed
valid. We also present some ideas of what one can do in the case that the tests
indicate that the assumptions fail.
| [
{
"created": "Thu, 16 May 2019 18:00:02 GMT",
"version": "v1"
},
{
"created": "Mon, 27 Jul 2020 22:06:25 GMT",
"version": "v2"
}
] | 2020-11-11 | [
[
"Kovarik",
"Karol",
""
],
[
"Nadolsky",
"Pavel M.",
""
],
[
"Soper",
"Davison E.",
""
]
] | Parton distribution functions (PDFs) describe the structure of hadrons as composed of quarks and gluons. They are needed to make predictions for short-distance processes in high-energy collisions and are determined by fitting to cross section data. We review definitions of the PDFs and their relations to high-energy cross sections. We focus on the PDFs in protons, but also discuss PDFs in nuclei. We review in some detail the standard statistical treatment needed to fit the PDFs to data using the Hessian method. We discuss tests that can be used to critically examine whether the assumptions are indeed valid. We also present some ideas of what one can do in the case that the tests indicate that the assumptions fail. |
1710.06260 | Hao Sun | Hao Sun | Overview of top quark physics at the ep colliders | 5pages. to appear in the proceedings of 25th International Workshop
on Deep Inelastic Scattering and Related Topics (DIS 2017), 3-7 April 2017,
University of Birmingham, UK | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this talk we present a short overview of top physics at the
electron-proton (ep) colliders. Currently, the proposed ep collider is the
Large Hadron Electron Collider (LHeC), which is a combination of 60 GeV
electron beam and 7 TeV proton beam of the LHC tunnel. This may be extended to
Future Circular electron-hadron Collider (FCC-eh), which features a 60 GeV (or
higher) electron beam with the 50 TeV proton beam from the Future Circular
hadron Collider (FCC-hh). Selected topics include but not limited to top
structure function, top parton distribution functions, top spin polarization,
top electric charge, measurement of $\rm V_{tb}$, anomalous $\rm tt\gamma$,
ttZ, tbW, $\rm tq\gamma$, tqH couplings and CP phase of ttH coupling.
| [
{
"created": "Tue, 17 Oct 2017 13:29:24 GMT",
"version": "v1"
}
] | 2017-10-18 | [
[
"Sun",
"Hao",
""
]
] | In this talk we present a short overview of top physics at the electron-proton (ep) colliders. Currently, the proposed ep collider is the Large Hadron Electron Collider (LHeC), which is a combination of 60 GeV electron beam and 7 TeV proton beam of the LHC tunnel. This may be extended to Future Circular electron-hadron Collider (FCC-eh), which features a 60 GeV (or higher) electron beam with the 50 TeV proton beam from the Future Circular hadron Collider (FCC-hh). Selected topics include but not limited to top structure function, top parton distribution functions, top spin polarization, top electric charge, measurement of $\rm V_{tb}$, anomalous $\rm tt\gamma$, ttZ, tbW, $\rm tq\gamma$, tqH couplings and CP phase of ttH coupling. |
hep-ph/0205255 | Jonathan L. Rosner | Stephen Godfrey and Jonathan L. Rosner | Production of singlet P-wave $c \bar c$ and $b \bar b$ states | 13 pages, LaTeX, 1 figure, to be published Phys. Rev. D. Some
equation numbers and one table number corrected | Phys.Rev.D66:014012,2002 | 10.1103/PhysRevD.66.014012 | EFI 02-79 | hep-ph | null | No spin-singlet $b \bar b$ quarkonium state has yet been observed. In this
paper we discuss the production of the singlet P-wave $b\bar{b}$ and $c\bar{c}$
$^1P_1$ states $h_b$ and $h_c$. We consider two possibilities. In the first the
$^1P_1$ states are produced via the electromagnetic cascades $\ups(3S) \to
\eta_b(2S) + \gamma \to h_b + \gamma \gamma \to \eta_b +\gamma\gamma\gamma $
and $\psi'\to \eta_c' + \gamma \to h_c + \gamma \gamma \to \eta_c +
\gamma\gamma\gamma$. A more promising process consists of single pion
transition to the $^1P_1$ state followed by the radiative transition to the
$1^1S_0$ state: $\ups(3S)\to h_b + \pi^0 \to \eta_b + \pi^0 +\gamma$ and $\psi'
\to h_c + \pi^0 \to \eta_c + \pi^0 +\gamma$. For a million $\ups(3S)$ or
$\psi'$'s produced we expect these processes to produce several hundred events.
| [
{
"created": "Wed, 22 May 2002 20:29:35 GMT",
"version": "v1"
},
{
"created": "Tue, 18 Jun 2002 18:59:22 GMT",
"version": "v2"
}
] | 2011-06-24 | [
[
"Godfrey",
"Stephen",
""
],
[
"Rosner",
"Jonathan L.",
""
]
] | No spin-singlet $b \bar b$ quarkonium state has yet been observed. In this paper we discuss the production of the singlet P-wave $b\bar{b}$ and $c\bar{c}$ $^1P_1$ states $h_b$ and $h_c$. We consider two possibilities. In the first the $^1P_1$ states are produced via the electromagnetic cascades $\ups(3S) \to \eta_b(2S) + \gamma \to h_b + \gamma \gamma \to \eta_b +\gamma\gamma\gamma $ and $\psi'\to \eta_c' + \gamma \to h_c + \gamma \gamma \to \eta_c + \gamma\gamma\gamma$. A more promising process consists of single pion transition to the $^1P_1$ state followed by the radiative transition to the $1^1S_0$ state: $\ups(3S)\to h_b + \pi^0 \to \eta_b + \pi^0 +\gamma$ and $\psi' \to h_c + \pi^0 \to \eta_c + \pi^0 +\gamma$. For a million $\ups(3S)$ or $\psi'$'s produced we expect these processes to produce several hundred events. |
hep-ph/0308217 | Zhenwei Yang | Zhenwei Yang and Pengfei Zhuang | Deconfinement Phase Transition in an Expanding Quark system in
Relaxation Time Approximation | 7 pages, 7 figures | Phys.Rev. C69 (2004) 035203 | 10.1103/PhysRevC.69.035203 | null | hep-ph | null | We investigated the effects of nonequilibrium and collision terms on the
deconfinement phase transition of an expanding quark system in Friedberg-Lee
model in relaxation time approximation. By calculating the effective quark
potential, the critical temperature of the phase transition is dominated by the
mean field, while the collisions among quarks and mesons change the time
structure of the phase transition significantly.
| [
{
"created": "Thu, 21 Aug 2003 08:56:10 GMT",
"version": "v1"
},
{
"created": "Sat, 8 Nov 2003 07:24:40 GMT",
"version": "v2"
},
{
"created": "Sat, 20 Dec 2003 03:37:50 GMT",
"version": "v3"
}
] | 2009-11-10 | [
[
"Yang",
"Zhenwei",
""
],
[
"Zhuang",
"Pengfei",
""
]
] | We investigated the effects of nonequilibrium and collision terms on the deconfinement phase transition of an expanding quark system in Friedberg-Lee model in relaxation time approximation. By calculating the effective quark potential, the critical temperature of the phase transition is dominated by the mean field, while the collisions among quarks and mesons change the time structure of the phase transition significantly. |
1110.5182 | Malgorzata Worek | Malgorzata Worek | Phenomenological studies of top-pair production at Next-to-Leading order | 10 pages, 3 figures, 2 tables. Presented at the XXXV International
Conference of Theoretical Physics, Matter to the Deepest: Recent Developments
in Physics of Fundamental Interactions, Ustron11, 12-18 September 2011,
Ustron, Poland | Acta Phys.Polon.B42:2415-2423,2011 | 10.5506/APhysPolB.42.2415 | WUB/11-17 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The calculation of NLO QCD corrections to the $t\bar{t}\to
W^{+}W^{-}b\bar{b}\to e^{+}\nu_e \mu^{-}\bar{\nu}_{\mu}b\bar{b}$ process with
complete off-shell effects, is briefly summarized. Besides the total cross
section and its scale dependence, a few differential distributions at the
TeVatron run II and LHC are given. All results presented in this contribution
have been obtained with the help of the HELAC-NLO Monte Carlo framework.
| [
{
"created": "Mon, 24 Oct 2011 09:53:36 GMT",
"version": "v1"
}
] | 2011-11-24 | [
[
"Worek",
"Malgorzata",
""
]
] | The calculation of NLO QCD corrections to the $t\bar{t}\to W^{+}W^{-}b\bar{b}\to e^{+}\nu_e \mu^{-}\bar{\nu}_{\mu}b\bar{b}$ process with complete off-shell effects, is briefly summarized. Besides the total cross section and its scale dependence, a few differential distributions at the TeVatron run II and LHC are given. All results presented in this contribution have been obtained with the help of the HELAC-NLO Monte Carlo framework. |
1201.2111 | George Lazarides | N. Karagiannakis, G. Lazarides, C. Pallis | Dark Matter and Higgs Mass in the CMSSM with Yukawa Quasi-Unification | 13 pages including 4 figures and 1 table, talk given by G. Lazarides
at the 7th International Workshop on the Dark Side of the Universe, KITPC,
Beijing, China, September 26-30, 2011 (to appear in the proceedings) | null | 10.1088/1742-6596/384/1/012012 | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present an updated analysis of the constrained minimal supersymmetric
standard model with mu>0 supplemented by an `asymptotic' Yukawa coupling
quasi-unification condition, which allows an acceptable b-quark mass. Imposing
constraints from the cold dark matter abundance in the universe, B physics, the
muon anomalous magnetic moment, and the mass m_h of the lightest neutral
CP-even Higgs boson, we find that the lightest neutralino cannot act as a cold
dark matter candidate. This is mainly because the upper bound on the lightest
neutralino relic abundance from cold dark matter considerations, despite the
fact that this abundance is drastically reduced by neutralino-stau
coannihilations, is incompatible with the recent data on the branching ratio of
B_s --> mu^+ mu^-. Allowing for a different particle, such as the axino or the
gravitino, to be the lightest supersymmetric particle and, thus, constitute the
cold dark matter in the universe, we find that the predicted m_h's in our model
favor the range (119-126) GeV.
| [
{
"created": "Tue, 10 Jan 2012 16:56:49 GMT",
"version": "v1"
},
{
"created": "Fri, 13 Jan 2012 11:19:39 GMT",
"version": "v2"
}
] | 2015-06-03 | [
[
"Karagiannakis",
"N.",
""
],
[
"Lazarides",
"G.",
""
],
[
"Pallis",
"C.",
""
]
] | We present an updated analysis of the constrained minimal supersymmetric standard model with mu>0 supplemented by an `asymptotic' Yukawa coupling quasi-unification condition, which allows an acceptable b-quark mass. Imposing constraints from the cold dark matter abundance in the universe, B physics, the muon anomalous magnetic moment, and the mass m_h of the lightest neutral CP-even Higgs boson, we find that the lightest neutralino cannot act as a cold dark matter candidate. This is mainly because the upper bound on the lightest neutralino relic abundance from cold dark matter considerations, despite the fact that this abundance is drastically reduced by neutralino-stau coannihilations, is incompatible with the recent data on the branching ratio of B_s --> mu^+ mu^-. Allowing for a different particle, such as the axino or the gravitino, to be the lightest supersymmetric particle and, thus, constitute the cold dark matter in the universe, we find that the predicted m_h's in our model favor the range (119-126) GeV. |
2404.15138 | Raghunath Sahoo | Bhagyarathi Sahoo, Captain R. Singh, and Raghunath Sahoo | Estimating Longitudinal Polarization of $\Lambda$ and $\bar{\Lambda}$
Hyperons at Relativistic Energies using Hydrodynamic and Transport models | 9 pages and two captioned figures. Submitted for publication | null | null | null | hep-ph hep-ex nucl-ex nucl-th | http://creativecommons.org/licenses/by-sa/4.0/ | The global and local polarization measurements of $\Lambda$ ($\bar{\Lambda}$)
hyperons by STAR and ALICE Collaborations open up an immense interest in
investigating the polarization dynamics in heavy-ion collisions. Recent studies
suggest the transverse component of the vorticity field is responsible for the
global spin polarization, while the longitudinal component of the vorticity
field accounts for the local polarization. The local polarization of
$\Lambda$-hyperons arises due to the anisotropic flows in the transverse plane,
indicating a quadrupole pattern of the longitudinal vorticity along the beam
direction. The present study focuses on the local (longitudinal) polarization
of $\Lambda$ and $\bar{\Lambda}$ in Au$+$Au and Pb$+$Pb collisions at
$\sqrt{s_{NN}}$ = 200 GeV and 5.02 TeV, respectively. Further, we explore the
centrality and transverse momentum ($p_{\rm T}$) dependence of longitudinal
polarization using hydrodynamic and transport models. All these models predict
a maximum longitudinal polarization in mid-central collisions around 30-50 \%
centrality at $p_{\rm T} \approx$ 2.0 - 3.0 GeV/c. These findings on
longitudinal polarization advocate the existence of a thermal medium in
non-central heavy-ion collisions. Our findings are in agreement with
corresponding experimental data at the RHIC and LHC energies.
| [
{
"created": "Tue, 23 Apr 2024 15:43:49 GMT",
"version": "v1"
}
] | 2024-04-24 | [
[
"Sahoo",
"Bhagyarathi",
""
],
[
"Singh",
"Captain R.",
""
],
[
"Sahoo",
"Raghunath",
""
]
] | The global and local polarization measurements of $\Lambda$ ($\bar{\Lambda}$) hyperons by STAR and ALICE Collaborations open up an immense interest in investigating the polarization dynamics in heavy-ion collisions. Recent studies suggest the transverse component of the vorticity field is responsible for the global spin polarization, while the longitudinal component of the vorticity field accounts for the local polarization. The local polarization of $\Lambda$-hyperons arises due to the anisotropic flows in the transverse plane, indicating a quadrupole pattern of the longitudinal vorticity along the beam direction. The present study focuses on the local (longitudinal) polarization of $\Lambda$ and $\bar{\Lambda}$ in Au$+$Au and Pb$+$Pb collisions at $\sqrt{s_{NN}}$ = 200 GeV and 5.02 TeV, respectively. Further, we explore the centrality and transverse momentum ($p_{\rm T}$) dependence of longitudinal polarization using hydrodynamic and transport models. All these models predict a maximum longitudinal polarization in mid-central collisions around 30-50 \% centrality at $p_{\rm T} \approx$ 2.0 - 3.0 GeV/c. These findings on longitudinal polarization advocate the existence of a thermal medium in non-central heavy-ion collisions. Our findings are in agreement with corresponding experimental data at the RHIC and LHC energies. |
1905.00583 | Jialun Ping | Xuejie Liu, Hongxia Huang, Jialun Ping | Investigate the pentaquark resonance in the $NK$ system | 7 pages, 4 figures | Phys. Rev. C 100, 025203 (2019) | 10.1103/PhysRevC.100.025203 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A dynamical calculation of pentaquark systems with quark contents
$uudd\bar{s}$ is performed in the framework of quark delocalization color
screening model with the help of resonating group method. The effective
potentials between baryon and meson clusters are given, and the possible bound
states or resonances are investigated. The single calculations show that the
$NK^{*}$ with $I=0, J^{P}=\frac{1}{2}^{-}$, $\Delta K^{*}$ with $I=1,
J^{P}=\frac{1}{2}^{-}$, and $\Delta K^{*}$ with $I=2, J^{P}=\frac{3}{2}^{-}$
are all bound, but they all turns into scattering states by coupling with the
corresponding open channels. A possible resonance state $\Delta K^{*}$ with
$I=1, J^{P}=\frac{5}{2}^{-}$ is proposed. The mass is around $2110.5$ MeV, and
the decay modes are $NK$ in $D$-wave or $NK\pi\pi$ in $P$-waves.
| [
{
"created": "Thu, 2 May 2019 06:18:37 GMT",
"version": "v1"
}
] | 2019-08-14 | [
[
"Liu",
"Xuejie",
""
],
[
"Huang",
"Hongxia",
""
],
[
"Ping",
"Jialun",
""
]
] | A dynamical calculation of pentaquark systems with quark contents $uudd\bar{s}$ is performed in the framework of quark delocalization color screening model with the help of resonating group method. The effective potentials between baryon and meson clusters are given, and the possible bound states or resonances are investigated. The single calculations show that the $NK^{*}$ with $I=0, J^{P}=\frac{1}{2}^{-}$, $\Delta K^{*}$ with $I=1, J^{P}=\frac{1}{2}^{-}$, and $\Delta K^{*}$ with $I=2, J^{P}=\frac{3}{2}^{-}$ are all bound, but they all turns into scattering states by coupling with the corresponding open channels. A possible resonance state $\Delta K^{*}$ with $I=1, J^{P}=\frac{5}{2}^{-}$ is proposed. The mass is around $2110.5$ MeV, and the decay modes are $NK$ in $D$-wave or $NK\pi\pi$ in $P$-waves. |
1806.04140 | Anatoli Fedynitch | Anatoli Fedynitch, Felix Riehn, Ralph Engel, Thomas K. Gaisser, Todor
Stanev | The hadronic interaction model Sibyll-2.3c and inclusive lepton fluxes | null | Phys. Rev. D 100, 103018 (2019) | 10.1103/PhysRevD.100.103018 | null | hep-ph astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Muons and neutrinos from cosmic ray interactions in the atmosphere originate
from decays of mesons in air-showers. Sibyll-2.3c aims to give a precise
description of hadronic interactions in the relevant phase space for
conventional and prompt leptons in light of new accelerator data, including
that from the LHC. Sibyll is designed primarily as an event generator for use
in simulation of extensive air showers. Because it has been tuned for forward
physics as well as the central region, it can also be used to calculate
inclusive fluxes. The purpose of this paper is to describe the use of
Sibyll-2.3c for calculation of fluxes of atmospheric leptons.
| [
{
"created": "Mon, 11 Jun 2018 18:00:00 GMT",
"version": "v1"
},
{
"created": "Fri, 5 Jun 2020 07:05:59 GMT",
"version": "v2"
}
] | 2020-06-08 | [
[
"Fedynitch",
"Anatoli",
""
],
[
"Riehn",
"Felix",
""
],
[
"Engel",
"Ralph",
""
],
[
"Gaisser",
"Thomas K.",
""
],
[
"Stanev",
"Todor",
""
]
] | Muons and neutrinos from cosmic ray interactions in the atmosphere originate from decays of mesons in air-showers. Sibyll-2.3c aims to give a precise description of hadronic interactions in the relevant phase space for conventional and prompt leptons in light of new accelerator data, including that from the LHC. Sibyll is designed primarily as an event generator for use in simulation of extensive air showers. Because it has been tuned for forward physics as well as the central region, it can also be used to calculate inclusive fluxes. The purpose of this paper is to describe the use of Sibyll-2.3c for calculation of fluxes of atmospheric leptons. |
1406.2591 | Chong Sheng Li | Fa Peng Huang, Chong Sheng Li, Hai Tao Li, Jian Wang | Renormalization-group improved predictions for Higgs boson production at
large $p_T$ | 31 pages, 17 figures, version published in Phys.Rev.D | Phys. Rev. D 90, 094024 (2014) | 10.1103/PhysRevD.90.094024 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the next-to-next-to-leading logarithmic order resummation for the
large $p_T$ Higgs boson production at the LHC in the framework of
soft-collinear effective theory. We find that the resummation effects reduce
the scale uncertainty significantly and decrease the QCD NLO results by about
$11\%$ in the large $p_T$ region. The finite top quark mass effects and the
effects of the NNLO singular terms are also discussed.
| [
{
"created": "Tue, 10 Jun 2014 15:23:25 GMT",
"version": "v1"
},
{
"created": "Wed, 11 Jun 2014 10:52:02 GMT",
"version": "v2"
},
{
"created": "Tue, 18 Nov 2014 16:03:06 GMT",
"version": "v3"
}
] | 2014-11-26 | [
[
"Huang",
"Fa Peng",
""
],
[
"Li",
"Chong Sheng",
""
],
[
"Li",
"Hai Tao",
""
],
[
"Wang",
"Jian",
""
]
] | We study the next-to-next-to-leading logarithmic order resummation for the large $p_T$ Higgs boson production at the LHC in the framework of soft-collinear effective theory. We find that the resummation effects reduce the scale uncertainty significantly and decrease the QCD NLO results by about $11\%$ in the large $p_T$ region. The finite top quark mass effects and the effects of the NNLO singular terms are also discussed. |
hep-ph/0201108 | Sachiko Takeuchi | Sachiko Takeuchi and Kiyotaka Shimizu | Quark Model and Equivalent Local Potential | 11 pages including 15 figures | Phys.Rev. C65 (2002) 064006 | 10.1103/PhysRevC.65.064006 | null | hep-ph | null | In this paper, we investigate the short-range repulsion given by the quark
cluster model employing an inverse scattering problem. We find that the local
potential which reproduces the same phase shifts to those given by the quark
cluster model has a strong repulsion at short distances in the NN1s0 channel.
There, however, appears an attractive pocket at very short distances due to a
rather weak repulsive behavior at very high energy region. This
repulsion-attractive-pocket structure becomes more manifest in the channel
which has an almost forbidden state, SigmaN(T=3/2)3s1. In order to see what
kinds of effects are important to reproduce the short-range repulsion in the
quark cluster model, we investigate the contribution coming from the
one-gluon-exchange potential and the normalization separately. It is clarified
that the gluon exchange constructs the short-range repulsion in the NN1s0 while
the quark Pauli-blocking effect governs the feature of the repulsive behavior
in the SigmaN(T=3/2)3s1 channel.
| [
{
"created": "Sun, 13 Jan 2002 11:58:20 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Takeuchi",
"Sachiko",
""
],
[
"Shimizu",
"Kiyotaka",
""
]
] | In this paper, we investigate the short-range repulsion given by the quark cluster model employing an inverse scattering problem. We find that the local potential which reproduces the same phase shifts to those given by the quark cluster model has a strong repulsion at short distances in the NN1s0 channel. There, however, appears an attractive pocket at very short distances due to a rather weak repulsive behavior at very high energy region. This repulsion-attractive-pocket structure becomes more manifest in the channel which has an almost forbidden state, SigmaN(T=3/2)3s1. In order to see what kinds of effects are important to reproduce the short-range repulsion in the quark cluster model, we investigate the contribution coming from the one-gluon-exchange potential and the normalization separately. It is clarified that the gluon exchange constructs the short-range repulsion in the NN1s0 while the quark Pauli-blocking effect governs the feature of the repulsive behavior in the SigmaN(T=3/2)3s1 channel. |
1005.1382 | Gergely Fejos | G. Fejos and A. Patkos | A renormalized large-n solution of the U(n) x U(n) linear sigma model in
the broken symmetry phase | RevTeX4, 14 pages, 2 figures. Version published in Phys. Rev. D | Phys.Rev.D82:045011,2010 | 10.1103/PhysRevD.82.045011 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Dyson-Schwinger equations for the U(n) x U(n) symmetric matrix sigma model
reformulated with two auxiliary fields in a background breaking the symmetry to
U(n) are studied in the so-called bare vertex approximation. A large n solution
is constructed under the supplementary assumption so that the scalar components
are much heavier than the pseudoscalars. The renormalizability of the solution
is investigated by explicit construction of the counterterms.
| [
{
"created": "Sun, 9 May 2010 10:59:39 GMT",
"version": "v1"
},
{
"created": "Mon, 9 Aug 2010 15:28:35 GMT",
"version": "v2"
}
] | 2014-11-21 | [
[
"Fejos",
"G.",
""
],
[
"Patkos",
"A.",
""
]
] | Dyson-Schwinger equations for the U(n) x U(n) symmetric matrix sigma model reformulated with two auxiliary fields in a background breaking the symmetry to U(n) are studied in the so-called bare vertex approximation. A large n solution is constructed under the supplementary assumption so that the scalar components are much heavier than the pseudoscalars. The renormalizability of the solution is investigated by explicit construction of the counterterms. |
1502.03459 | Juan M. Torres-Rincon | Juan M. Torres-Rincon, Benjamin Sintes and Joerg Aichelin | Flavor dependence of baryon melting temperature in effective models of
QCD | 23 pages, 12 figures, 6 appendices. v2: Quark condensates and
susceptibilities are presented. One parameter of the PNJL model is modified
to account for its dependence on the number of flavors; this brings a better
agreement between the NJL and PNJL models. Typos are corrected and new
references added. Version accepted for its publication in the Physical Review
C journal | Phys. Rev. C 91, 065206 (2015) | 10.1103/PhysRevC.91.065206 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We apply the three-flavor (Polyakov-)Nambu-Jona-Lasinio model to generate
baryons as quark-diquark bound states using many-body techniques at finite
temperature. All the baryonic states belonging to the octet and decuplet flavor
representations are generated in the isospin-symmetric case. For each state we
extract the melting temperature at which the baryon may decay into a
quark-diquark pair. We seek for an evidence of the strangeness dependence of
the baryon melting temperature as suggested by the statistical thermal models
and supported by lattice-QCD results. A clear and robust signal for this claim
is found, pointing to a flavor dependence of the hadronic deconfinement
temperature.
| [
{
"created": "Wed, 11 Feb 2015 21:18:51 GMT",
"version": "v1"
},
{
"created": "Tue, 16 Jun 2015 20:16:08 GMT",
"version": "v2"
}
] | 2015-07-01 | [
[
"Torres-Rincon",
"Juan M.",
""
],
[
"Sintes",
"Benjamin",
""
],
[
"Aichelin",
"Joerg",
""
]
] | We apply the three-flavor (Polyakov-)Nambu-Jona-Lasinio model to generate baryons as quark-diquark bound states using many-body techniques at finite temperature. All the baryonic states belonging to the octet and decuplet flavor representations are generated in the isospin-symmetric case. For each state we extract the melting temperature at which the baryon may decay into a quark-diquark pair. We seek for an evidence of the strangeness dependence of the baryon melting temperature as suggested by the statistical thermal models and supported by lattice-QCD results. A clear and robust signal for this claim is found, pointing to a flavor dependence of the hadronic deconfinement temperature. |
0907.4932 | Shao-Long Chen | Shmuel Nussinov, Chen Jacoby | Some Comments on the `Quirks' Scenario | 14 pages | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss various aspects of models with long-lived or stable colored
particles. In particular we focus on an ideal Quirk model with electroweak
neutral heavy (O(TeV)) particles which carry ordinary color and another $
SU'(3)$ color with a very low scale $\Lambda'$. We show that contrary to what
one might think, such a model is cosmologically consistent and evades many
"Pitfalls" even for very low O(10 eV) $\Lambda'$ and without assuming a low
reheat temperature. We also show that the expected production of Quirks by
cosmic rays which are incorporated in heavy Isotopes in Ocean water is
consistent with the highly stringent bounds on the latter. This evades a real
threat to the Quirk model which would have excluded it regardless of Cosmology.
Finally we briefly comment on possible LHC signatures.
| [
{
"created": "Tue, 28 Jul 2009 15:20:32 GMT",
"version": "v1"
}
] | 2009-07-29 | [
[
"Nussinov",
"Shmuel",
""
],
[
"Jacoby",
"Chen",
""
]
] | We discuss various aspects of models with long-lived or stable colored particles. In particular we focus on an ideal Quirk model with electroweak neutral heavy (O(TeV)) particles which carry ordinary color and another $ SU'(3)$ color with a very low scale $\Lambda'$. We show that contrary to what one might think, such a model is cosmologically consistent and evades many "Pitfalls" even for very low O(10 eV) $\Lambda'$ and without assuming a low reheat temperature. We also show that the expected production of Quirks by cosmic rays which are incorporated in heavy Isotopes in Ocean water is consistent with the highly stringent bounds on the latter. This evades a real threat to the Quirk model which would have excluded it regardless of Cosmology. Finally we briefly comment on possible LHC signatures. |
hep-ph/0110399 | A. A. Arkhipov | A.A. Arkhipov | On a Manifestation of Dibaryon Resonances in the Structure of
Proton-Proton Total Cross-Section at Low Energies | The talk presented at the IXth International Conference on Hadron
Spectroscopy HADRON 2001, Protvino, Russia, August 25-September 1, 2001; 3
eps-figures | AIP Conf.Proc. 619 (2002) 771-776 | 10.1063/1.1482536 | IHEP 2001-44 | hep-ph | null | A manifestation of narrow diproton resonances in the early discovered global
structure of proton-proton total cross section at low energies is discussed. It
is also discussed the existence of new particle with the mass $1.833 MeV$
predicted early.
| [
{
"created": "Wed, 31 Oct 2001 14:37:55 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Arkhipov",
"A. A.",
""
]
] | A manifestation of narrow diproton resonances in the early discovered global structure of proton-proton total cross section at low energies is discussed. It is also discussed the existence of new particle with the mass $1.833 MeV$ predicted early. |
hep-ph/0107146 | Thorsten Renk | T. Renk, R.A. Schneider and W. Weise | Hadronic and Quark-Gluon Excitations of Dense and Hot Matter | 9 pages, 7 figures, Invited talk presented by W. Weise at the 3rd
International Conference on Perspectives in Hadron Physics, ICTP, Trieste,
7-11 May 2001 | Nucl.Phys. A699 (2002) 1-9 | 10.1016/S0375-9474(01)01463-4 | null | hep-ph | null | We summarize recent developments in our understanding of low-mass
quark-antiquark excitations in hadronic matter under various different
conditions. This includes the thermodynamics of the chiral condensate, pions as
Goldstone bosons in normal nuclear matter, and excursions into extreme
territory of the QCD phase diagram: lepton pair production from a fireball
expanding through the transition boundary between the quark-gluon and hadron
pha ses of QCD.
| [
{
"created": "Fri, 13 Jul 2001 08:44:47 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Renk",
"T.",
""
],
[
"Schneider",
"R. A.",
""
],
[
"Weise",
"W.",
""
]
] | We summarize recent developments in our understanding of low-mass quark-antiquark excitations in hadronic matter under various different conditions. This includes the thermodynamics of the chiral condensate, pions as Goldstone bosons in normal nuclear matter, and excursions into extreme territory of the QCD phase diagram: lepton pair production from a fireball expanding through the transition boundary between the quark-gluon and hadron pha ses of QCD. |
1512.04259 | Masaki Yamada | Masahiro Kawasaki, Masaki Yamada, Tsutomu T. Yanagida, Norimi Yokozaki | High-scale SUSY from an R-invariant New Inflation in the Landscape | 17 pages, 1 figure | Phys. Rev. D 93, 055022 (2016) | 10.1103/PhysRevD.93.055022 | IPMU 15-0210 | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We provide an anthropic reason that the supersymmetry breaking scale is much
higher than the electroweak scale as indicated by the null result of collider
experiments and observed 125 GeV Higgs boson. We focus on a new inflation model
as a typical low-scale inflation model that may be expected in the string
landscape. In this model, the R-symmetry is broken at the minimum of the
inflaton potential and its breaking scale is related to the reheating
temperature. Once we admit that the anthropic principle requires thermal
leptogenesis, we obtain a lower bound on gravitino mass, which is related to
R-symmetry breaking scale. This scenario and resulting gravitino mass predict
the consistent amplitude of density perturbations. We also find that string
axions and saxions are consistently implemented in this scenario.
| [
{
"created": "Mon, 14 Dec 2015 11:13:34 GMT",
"version": "v1"
}
] | 2016-03-23 | [
[
"Kawasaki",
"Masahiro",
""
],
[
"Yamada",
"Masaki",
""
],
[
"Yanagida",
"Tsutomu T.",
""
],
[
"Yokozaki",
"Norimi",
""
]
] | We provide an anthropic reason that the supersymmetry breaking scale is much higher than the electroweak scale as indicated by the null result of collider experiments and observed 125 GeV Higgs boson. We focus on a new inflation model as a typical low-scale inflation model that may be expected in the string landscape. In this model, the R-symmetry is broken at the minimum of the inflaton potential and its breaking scale is related to the reheating temperature. Once we admit that the anthropic principle requires thermal leptogenesis, we obtain a lower bound on gravitino mass, which is related to R-symmetry breaking scale. This scenario and resulting gravitino mass predict the consistent amplitude of density perturbations. We also find that string axions and saxions are consistently implemented in this scenario. |
2405.12972 | Congqiao Li | Congqiao Li, Antonios Agapitos, Jovin Drews, Javier Duarte, Dawei Fu,
Leyun Gao, Raghav Kansal, Gregor Kasieczka, Louis Moureaux, Huilin Qu,
Cristina Mantilla Suarez, Qiang Li | Accelerating Resonance Searches via Signature-Oriented Pre-training | 14 pages, 5 figures | null | null | null | hep-ph hep-ex physics.data-an | http://creativecommons.org/licenses/by/4.0/ | The search for heavy resonances beyond the Standard Model (BSM) is a key
objective at the LHC. While the recent use of advanced deep neural networks for
boosted-jet tagging significantly enhances the sensitivity of dedicated
searches, it is limited to specific final states, leaving vast potential BSM
phase space underexplored. We introduce a novel experimental method,
Signature-Oriented Pre-training for Heavy-resonance ObservatioN (Sophon), which
leverages deep learning to cover an extensive number of boosted final states.
Pre-trained on the comprehensive JetClass-II dataset, the Sophon model learns
intricate jet signatures, ensuring the optimal constructions of various jet
tagging discriminates and enabling high-performance transfer learning
capabilities. We show that the method can not only push widespread
model-specific searches to their sensitivity frontier, but also greatly improve
model-agnostic approaches, accelerating LHC resonance searches in a broad
sense.
| [
{
"created": "Tue, 21 May 2024 17:54:53 GMT",
"version": "v1"
}
] | 2024-05-22 | [
[
"Li",
"Congqiao",
""
],
[
"Agapitos",
"Antonios",
""
],
[
"Drews",
"Jovin",
""
],
[
"Duarte",
"Javier",
""
],
[
"Fu",
"Dawei",
""
],
[
"Gao",
"Leyun",
""
],
[
"Kansal",
"Raghav",
""
],
[
"Kasieczka"... | The search for heavy resonances beyond the Standard Model (BSM) is a key objective at the LHC. While the recent use of advanced deep neural networks for boosted-jet tagging significantly enhances the sensitivity of dedicated searches, it is limited to specific final states, leaving vast potential BSM phase space underexplored. We introduce a novel experimental method, Signature-Oriented Pre-training for Heavy-resonance ObservatioN (Sophon), which leverages deep learning to cover an extensive number of boosted final states. Pre-trained on the comprehensive JetClass-II dataset, the Sophon model learns intricate jet signatures, ensuring the optimal constructions of various jet tagging discriminates and enabling high-performance transfer learning capabilities. We show that the method can not only push widespread model-specific searches to their sensitivity frontier, but also greatly improve model-agnostic approaches, accelerating LHC resonance searches in a broad sense. |
1101.4760 | Daniel Mueller | Jochen Wambach | Recent Theoretical Developments in the QCD Phase Diagram | 9 pages, 11 figures, proceedings for the International Workshop on
Hot and Cold Baryonic Matter 2010, Budapest, Aug. 15-20, 2010 | null | 10.1051/epjconf/20111302002 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this talk I discuss three recent developments in the theoretical
understanding of the phase diagram of the strong interaction. The first topic
deals with the comparison of model calculations of the quark-hadron transition
at vanishing quark chemical potential with state-of-the-art lattice QCD
results. In the second relates to the size of a possible 'quarkyonic phase'.
The third deals with the occurence of inhomogeneous chiral phases.
| [
{
"created": "Tue, 25 Jan 2011 10:01:15 GMT",
"version": "v1"
}
] | 2017-08-23 | [
[
"Wambach",
"Jochen",
""
]
] | In this talk I discuss three recent developments in the theoretical understanding of the phase diagram of the strong interaction. The first topic deals with the comparison of model calculations of the quark-hadron transition at vanishing quark chemical potential with state-of-the-art lattice QCD results. In the second relates to the size of a possible 'quarkyonic phase'. The third deals with the occurence of inhomogeneous chiral phases. |
hep-ph/0406071 | Tsuneo Uematsu | Ken Sasaki and Tsuneo Uematsu | Mass effects in the polarized virtual photon structure | 5 pages, LaTeX, 4 eps figures, npb.sty file included, Talk given at
Loops and Legs 2004, Zinnowitz, Germany, April 25-30, 2004, to appear in the
Proceedings | null | 10.1016/j.nuclphysbps.2004.09.047 | YNU-HEPTh-04-101, KUNS-1922 | hep-ph | null | We discuss target mass effects in the polarized virtual photon structure
functions $g_1^\gamma (x,Q^2,P^2)$, $g_2^\gamma (x,Q^2,P^2)$ for the kinematic
region $\Lambda^2\ll P^2 \ll Q^2$, where $-Q^2 (-P^2)$ is the mass squared of
the probe (target) photon. We obtain the expressions for the structure
functions in closed form by inverting the Nachtmann moments for the twist-2 and
twist-3 operators. Numerical analysis shows that target mass effects appear at
large $x$ and become sizable near the maximal value of $x$, as the ratio
$P^2/Q^2$ increases. Target mass effects for the QCD sum rules of $g_1^\gamma$
and $g_2^\gamma$ are also investigated.
| [
{
"created": "Mon, 7 Jun 2004 05:54:16 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Sasaki",
"Ken",
""
],
[
"Uematsu",
"Tsuneo",
""
]
] | We discuss target mass effects in the polarized virtual photon structure functions $g_1^\gamma (x,Q^2,P^2)$, $g_2^\gamma (x,Q^2,P^2)$ for the kinematic region $\Lambda^2\ll P^2 \ll Q^2$, where $-Q^2 (-P^2)$ is the mass squared of the probe (target) photon. We obtain the expressions for the structure functions in closed form by inverting the Nachtmann moments for the twist-2 and twist-3 operators. Numerical analysis shows that target mass effects appear at large $x$ and become sizable near the maximal value of $x$, as the ratio $P^2/Q^2$ increases. Target mass effects for the QCD sum rules of $g_1^\gamma$ and $g_2^\gamma$ are also investigated. |
1012.2022 | Hong-Hao Zhang | Jia-Ming Zheng, Zhao-Huan Yu, Jun-Wen Shao, Xiao-Jun Bi, Zhibing Li,
Hong-Hao Zhang | Constraining the interaction strength between dark matter and visible
matter: I. fermionic dark matter | 21 pages, 14 figures, errors in thermal averages corrected,
conclusions unaffected. Version to be published in Nucl. Phys. B | Nucl.Phys.B854:350-374,2012 | 10.1016/j.nuclphysb.2011.09.009 | null | hep-ph astro-ph.CO astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this work we study the constraints on the dark matter interaction with the
standard model particles, from the observations of dark matter relic density,
the direct detection experiments of CDMS and XENON, and the indirect detection
of the antiproton-to-proton ratio by PAMELA. A model independent way is adopted
in the study by constructing the effective interaction operators between dark
matter and standard model particles. The most general 4-fermion operators are
investigated. We find that the constraints from different observations are
complementary with each other. Especially the spin independent scattering gives
very strong constraints for corresponding operators. In some cases the indirect
detection of antiproton-to-proton data can actually be more sensitive than the
direct detection or relic density for light dark matter (less than 70 GeV).
| [
{
"created": "Thu, 9 Dec 2010 14:59:11 GMT",
"version": "v1"
},
{
"created": "Wed, 15 Dec 2010 14:44:34 GMT",
"version": "v2"
},
{
"created": "Wed, 14 Sep 2011 17:41:28 GMT",
"version": "v3"
}
] | 2011-10-07 | [
[
"Zheng",
"Jia-Ming",
""
],
[
"Yu",
"Zhao-Huan",
""
],
[
"Shao",
"Jun-Wen",
""
],
[
"Bi",
"Xiao-Jun",
""
],
[
"Li",
"Zhibing",
""
],
[
"Zhang",
"Hong-Hao",
""
]
] | In this work we study the constraints on the dark matter interaction with the standard model particles, from the observations of dark matter relic density, the direct detection experiments of CDMS and XENON, and the indirect detection of the antiproton-to-proton ratio by PAMELA. A model independent way is adopted in the study by constructing the effective interaction operators between dark matter and standard model particles. The most general 4-fermion operators are investigated. We find that the constraints from different observations are complementary with each other. Especially the spin independent scattering gives very strong constraints for corresponding operators. In some cases the indirect detection of antiproton-to-proton data can actually be more sensitive than the direct detection or relic density for light dark matter (less than 70 GeV). |
hep-ph/9806446 | Indranil Dasgupta | Indranil Dasgupta and L. C. R. Wijewardhana | Chiral Symmetry Breaking in 2+1 dimensions due to Sphalerons | 15 pages, LaTex, 1 figure, uses epsf | Phys. Rev. D 58, 116004 (1998) | 10.1103/PhysRevD.58.116004 | UCTP 109/98 | hep-ph | null | In 2+1 dimensional gauge thories with $SU(N_c)$ color and $2N_f$ flavors of
quarks in the fundamental representation, sphalerons, if present may lead to
quark condensation and chiral symmetry breaking. The effect is similar to
instanton induced chiral symmetry breaking in 3+1 dimensions and is due to the
interaction of quark propagators with sphalerons. The existence of sphalerons
requires that color symmetries be broken by a Higgs in the fundamental
representation. We show that the sphaleron effect may persist for arbitrarily
large $N_f$ but vanishes along with the mass of the gauge fields corresponding
to broken generators of $SU(N_c)$. The effect is inherently non-Abelian and
absent for QED.
| [
{
"created": "Mon, 22 Jun 1998 22:00:49 GMT",
"version": "v1"
}
] | 2016-08-25 | [
[
"Dasgupta",
"Indranil",
""
],
[
"Wijewardhana",
"L. C. R.",
""
]
] | In 2+1 dimensional gauge thories with $SU(N_c)$ color and $2N_f$ flavors of quarks in the fundamental representation, sphalerons, if present may lead to quark condensation and chiral symmetry breaking. The effect is similar to instanton induced chiral symmetry breaking in 3+1 dimensions and is due to the interaction of quark propagators with sphalerons. The existence of sphalerons requires that color symmetries be broken by a Higgs in the fundamental representation. We show that the sphaleron effect may persist for arbitrarily large $N_f$ but vanishes along with the mass of the gauge fields corresponding to broken generators of $SU(N_c)$. The effect is inherently non-Abelian and absent for QED. |
2006.09974 | Sorina Lazanu | Ionel Lazanu, Sorina Lazanu and Mihaela P\^arvu | About detecting very low mass black holes in LAr detectors | substantially improved version | JCAP 10 (2020) 046 | 10.1088/1475-7516/2020/10/046 | null | hep-ph astro-ph.IM physics.ins-det | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The nature of dark matter is still an open problem. The simplest assumption
is that gravity is the only force coupled certainly to dark matter and thus the
micro black holes could be a viable candidate. We investigated the possibility
of direct detection of micro black holes with masses around and upward the
Planck scale (10$^{-5}$ g), ensuring classical gravitational treatment of these
objects in the next generation of huge LAr detectors. We show that the signals
(ionization and scintillation) produced in LAr enable the discrimination
between micro black holes or other particles. It is expected that the
trajectories of these micro black holes will appear as crossing the whole
active medium, in any direction, producing uniform ionization and scintillation
on all the path.
| [
{
"created": "Fri, 12 Jun 2020 18:43:58 GMT",
"version": "v1"
},
{
"created": "Thu, 22 Oct 2020 05:54:17 GMT",
"version": "v2"
}
] | 2020-10-23 | [
[
"Lazanu",
"Ionel",
""
],
[
"Lazanu",
"Sorina",
""
],
[
"Pârvu",
"Mihaela",
""
]
] | The nature of dark matter is still an open problem. The simplest assumption is that gravity is the only force coupled certainly to dark matter and thus the micro black holes could be a viable candidate. We investigated the possibility of direct detection of micro black holes with masses around and upward the Planck scale (10$^{-5}$ g), ensuring classical gravitational treatment of these objects in the next generation of huge LAr detectors. We show that the signals (ionization and scintillation) produced in LAr enable the discrimination between micro black holes or other particles. It is expected that the trajectories of these micro black holes will appear as crossing the whole active medium, in any direction, producing uniform ionization and scintillation on all the path. |
1509.02528 | Nikolaos Kidonakis | Nikolaos Kidonakis | N$^3$LO calculations for top-quark differential cross sections near
partonic threshold | 10 pages, 7 figures; presented at Radcor 2015 and Loopfest XIV, Los
Angeles, California, 15-19 June 2015; to appear in PoS(RADCOR2015). arXiv
admin note: text overlap with arXiv:1506.04068 | PoS (RADCOR2015) 033 | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | I present calculations of approximate corrections from NNLL soft-gluon
resummation for total and differential cross sections in top-antitop pair
production and single-top production in hadronic collisions. I show that
soft-gluon corrections from partonic threshold are the dominant contribution to
top-quark production and closely approximate exact results. I present aN$^3$LO
results for the total $t{\bar t}$ cross section, the top-quark $p_T$ and
rapidity distributions, and the top-quark forward-backward asymmetry. I also
provide updates for single-top production in the $t$, $s$, and $tW$ channels.
Finally, I discuss top-quark production via anomalous gluon couplings.
| [
{
"created": "Tue, 8 Sep 2015 20:08:16 GMT",
"version": "v1"
}
] | 2023-02-21 | [
[
"Kidonakis",
"Nikolaos",
""
]
] | I present calculations of approximate corrections from NNLL soft-gluon resummation for total and differential cross sections in top-antitop pair production and single-top production in hadronic collisions. I show that soft-gluon corrections from partonic threshold are the dominant contribution to top-quark production and closely approximate exact results. I present aN$^3$LO results for the total $t{\bar t}$ cross section, the top-quark $p_T$ and rapidity distributions, and the top-quark forward-backward asymmetry. I also provide updates for single-top production in the $t$, $s$, and $tW$ channels. Finally, I discuss top-quark production via anomalous gluon couplings. |
0807.3385 | A. B. Balantekin | A.B. Balantekin, I. Sahin, and B. Sahin | Tests of flavor universality for neutrino-Z couplings in future neutrino
experiments | LaTeX with 6 figures | Phys.Rev.D78:073003,2008 | 10.1103/PhysRevD.78.073003 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the physics potential of NuSOnG experiment to probe new
physics contributions to Z-neutrino-neutrino couplings in muon-neutrino
electron elastic and neutral-current deep-inelastic scattering processes. We
employ an effective Lagrangian approach and do not a priori assume universality
of the coupling of neutrinos to Z. We obtain 95% C.L. limits on possible
universality violating couplings.
| [
{
"created": "Tue, 22 Jul 2008 03:34:59 GMT",
"version": "v1"
},
{
"created": "Wed, 22 Oct 2008 22:34:17 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Balantekin",
"A. B.",
""
],
[
"Sahin",
"I.",
""
],
[
"Sahin",
"B.",
""
]
] | We investigate the physics potential of NuSOnG experiment to probe new physics contributions to Z-neutrino-neutrino couplings in muon-neutrino electron elastic and neutral-current deep-inelastic scattering processes. We employ an effective Lagrangian approach and do not a priori assume universality of the coupling of neutrinos to Z. We obtain 95% C.L. limits on possible universality violating couplings. |
hep-ph/0003034 | Mitesh Patel | Mitesh Patel, George M. Fuller (UCSD) | What are sterile neutrinos good for? | 8 pages REVTeX, 2 epsf figures, in proceedings of the American
Physical Society Division of Particles and Fields Conference (DPF'99), UCLA,
Jan. 1999, ed. K. Arisaka & Z. Bern | null | null | null | hep-ph astro-ph | null | Taken at face value, current experimental data indicate the existence of a
new particle, the sterile neutrino, which must be a singlet under the Standard
Model gauge group. Although they are not detectable through traditional means,
such particles have interesting observable consequences for particle
astrophysics and cosmology. Here we examine these implications and discuss, in
particular, sterile neutrino dark matter and the relationship between
matter-enhanced active-sterile neutrino transformation and the synthesis of
heavy elements in supernovae.
| [
{
"created": "Sun, 5 Mar 2000 05:28:08 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Patel",
"Mitesh",
"",
"UCSD"
],
[
"Fuller",
"George M.",
"",
"UCSD"
]
] | Taken at face value, current experimental data indicate the existence of a new particle, the sterile neutrino, which must be a singlet under the Standard Model gauge group. Although they are not detectable through traditional means, such particles have interesting observable consequences for particle astrophysics and cosmology. Here we examine these implications and discuss, in particular, sterile neutrino dark matter and the relationship between matter-enhanced active-sterile neutrino transformation and the synthesis of heavy elements in supernovae. |
hep-ph/9809486 | Wolfgang Kilian | W. Kilian and P.M. Zerwas | Aspects of Higgs physics and physics beyond the Standard Model at LHC
and e+e- linear colliders | 6 pages, LaTeX2e, uses ltwol2e.sty [included]. Summary of
contributions to PA10 at ICHEP'98 (Vancouver); to appear in the Proceedings | null | null | HD-THEP 98-49 | hep-ph hep-ex | null | Recent developments in prospects of searching for Higgs particles and testing
their properties at the LHC and at TeV e+e- linear colliders are summarized.
The discovery limits of supersymmetric particles at the LHC are presented and
the accuracy is explored with which the fundamental SUSY parameters in the
context of supergravity models can be determined at high-luminosity linear
colliders. Finally, new discovery limits for gauge bosons in left-right
symmetric models at the LHC are presented.
| [
{
"created": "Tue, 22 Sep 1998 21:42:01 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Kilian",
"W.",
""
],
[
"Zerwas",
"P. M.",
""
]
] | Recent developments in prospects of searching for Higgs particles and testing their properties at the LHC and at TeV e+e- linear colliders are summarized. The discovery limits of supersymmetric particles at the LHC are presented and the accuracy is explored with which the fundamental SUSY parameters in the context of supergravity models can be determined at high-luminosity linear colliders. Finally, new discovery limits for gauge bosons in left-right symmetric models at the LHC are presented. |
hep-ph/0309163 | Zong-Kuan Guo | Zong-Kuan Guo, Hong-Sheng Zhang and Yuan-Zhong Zhang | Inflationary Attractor in Braneworld Scenario | 7 pages, 8 figures, RevTeX, to appear in Phys. Rev. D69 (2004) | Phys.Rev. D69 (2004) 063502 | 10.1103/PhysRevD.69.063502 | null | hep-ph | null | We demonstrate the attractor behavior of inflation driven by a scalar field
or a tachyon field in the context of recently proposed four-dimensional
effective gravity induced on the world-volume of a three-brane in
five-dimensional Einstein gravity, and we obtain a set of exact inflationary
solutions. Phase portraits indicate that an initial kinetic term decays rapidly
and it does not prevent the onset of inflation. The trajectories more rapidly
reach the slow-roll curve than in the standard cosmology.
| [
{
"created": "Mon, 15 Sep 2003 08:56:10 GMT",
"version": "v1"
},
{
"created": "Tue, 10 Feb 2004 11:40:46 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Guo",
"Zong-Kuan",
""
],
[
"Zhang",
"Hong-Sheng",
""
],
[
"Zhang",
"Yuan-Zhong",
""
]
] | We demonstrate the attractor behavior of inflation driven by a scalar field or a tachyon field in the context of recently proposed four-dimensional effective gravity induced on the world-volume of a three-brane in five-dimensional Einstein gravity, and we obtain a set of exact inflationary solutions. Phase portraits indicate that an initial kinetic term decays rapidly and it does not prevent the onset of inflation. The trajectories more rapidly reach the slow-roll curve than in the standard cosmology. |
1401.7207 | Michael Klasen | M. Klasen | Parton density constraints from massive vector boson production at the
LHC | 6 pages, 3 figures. Proceedings of the 9th International Workshop on
High-pT Physics at LHC | null | 10.1088/1742-6596/589/1/012012 | MS-TP-14-05 | hep-ph hep-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We demonstrate that not only the production of virtual photons decaying into
low-mass lepton pairs, but also the one of weak bosons at large transverse
momenta is dominated by quark-gluon scattering. Measurements of these processes
at the LHC can therefore provide useful constraints on the parton densities in
the proton, in particular the one of the gluon, and their nuclear
modifications.
| [
{
"created": "Tue, 28 Jan 2014 15:04:26 GMT",
"version": "v1"
}
] | 2015-06-18 | [
[
"Klasen",
"M.",
""
]
] | We demonstrate that not only the production of virtual photons decaying into low-mass lepton pairs, but also the one of weak bosons at large transverse momenta is dominated by quark-gluon scattering. Measurements of these processes at the LHC can therefore provide useful constraints on the parton densities in the proton, in particular the one of the gluon, and their nuclear modifications. |
1601.01813 | Dani\"el Boer | Dani\"el Boer | Gluon TMD studies at EIC | 6 pages, no figures, contribution to the proceedings of the 6th
International conference on Physics Opportunities at an ElecTron-Ion Collider
(POETIC VI), \'Ecole Polytechnique, Palaiseau, France, September 7-11, 2015 | null | 10.1051/epjconf/201611202003 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A high-energy Electron-Ion Collider (EIC) would offer a most promising tool
to study in detail the transverse momentum distributions of gluons inside
hadrons. This applies to unpolarized as well as linearly polarized gluons
inside unpolarized protons, and to left-right asymmetric distributions of
gluons inside transversely polarized protons, the so-called gluon Sivers
effect. The inherent process dependence of these distributions can be studied
by comparing to similar, but often complementary observables at LHC.
| [
{
"created": "Fri, 8 Jan 2016 10:10:17 GMT",
"version": "v1"
}
] | 2016-04-20 | [
[
"Boer",
"Daniël",
""
]
] | A high-energy Electron-Ion Collider (EIC) would offer a most promising tool to study in detail the transverse momentum distributions of gluons inside hadrons. This applies to unpolarized as well as linearly polarized gluons inside unpolarized protons, and to left-right asymmetric distributions of gluons inside transversely polarized protons, the so-called gluon Sivers effect. The inherent process dependence of these distributions can be studied by comparing to similar, but often complementary observables at LHC. |
hep-ph/0211256 | Giacomo Morpurgo | G.Dillon, G.Morpurgo | Chiral QCD, General QCD Parameterization and Constituent Quark Models | 10 pages, Latex; abridged version (same results), removed some
references | Phys.Rev. D68 (2003) 014001 | 10.1103/PhysRevD.68.014001 | INFN-GEF-Th-13/02 | hep-ph | null | Several recent papers -using effective QCD chiral Lagrangians- reproduced
results obtained with the general QCD parameterization (GP). These include the
baryon 8+10 mass formula, the octet magnetic moments and the coincidental
nature of the "perfect" -3/2 ratio between the magnetic moments of p and n.
Although we anticipated that the GP covers the case of chiral treatments, the
above results explicitly exemplify this fact. Also we show by the GP that -in
any model or theory (chiral or non chiral) reproducing the results of exact
QCD- the Franklin (Coleman Glashow) sum rule for the octet magnetic moments
must be violated.
| [
{
"created": "Sat, 16 Nov 2002 15:57:17 GMT",
"version": "v1"
},
{
"created": "Tue, 11 Mar 2003 15:09:07 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Dillon",
"G.",
""
],
[
"Morpurgo",
"G.",
""
]
] | Several recent papers -using effective QCD chiral Lagrangians- reproduced results obtained with the general QCD parameterization (GP). These include the baryon 8+10 mass formula, the octet magnetic moments and the coincidental nature of the "perfect" -3/2 ratio between the magnetic moments of p and n. Although we anticipated that the GP covers the case of chiral treatments, the above results explicitly exemplify this fact. Also we show by the GP that -in any model or theory (chiral or non chiral) reproducing the results of exact QCD- the Franklin (Coleman Glashow) sum rule for the octet magnetic moments must be violated. |
hep-ph/0404159 | Domenico Falcone | F. Buccella, D. Falcone | Neutrinoless double beta decay in SO(10) inspired seesaw models | 9 pages, RevTex4. Revised, title changed | Mod.Phys.Lett. A19 (2004) 2993 | 10.1142/S0217732304016317 | DSF-44/2003 | hep-ph | null | By requiring the lower limit for the lightest right-handed neutrino mass,
obtained in the baryogenesis from leptogenesis scenario, and a Dirac neutrino
mass matrix similar to the up-quark mass matrix we predict small values for the
$\nu_e$ mass and for the matrix element $m_{ee}$ responsible of the
neutrinoless double beta decay, $m_{\nu_e}$ around $5\cdot10^{-3}$ eV and
$m_{ee}$ smaller than $ 10^{-3}$ eV, respectively. The allowed range for the
mass of the heaviest right-handed neutrino is centered around the value of the
scale of B - L breaking in the SO(10) gauge theory with Pati-Salam intermediate
symmetry.
| [
{
"created": "Mon, 19 Apr 2004 19:24:14 GMT",
"version": "v1"
},
{
"created": "Mon, 19 Apr 2004 20:00:24 GMT",
"version": "v2"
},
{
"created": "Sun, 2 Jan 2005 13:02:56 GMT",
"version": "v3"
}
] | 2009-11-10 | [
[
"Buccella",
"F.",
""
],
[
"Falcone",
"D.",
""
]
] | By requiring the lower limit for the lightest right-handed neutrino mass, obtained in the baryogenesis from leptogenesis scenario, and a Dirac neutrino mass matrix similar to the up-quark mass matrix we predict small values for the $\nu_e$ mass and for the matrix element $m_{ee}$ responsible of the neutrinoless double beta decay, $m_{\nu_e}$ around $5\cdot10^{-3}$ eV and $m_{ee}$ smaller than $ 10^{-3}$ eV, respectively. The allowed range for the mass of the heaviest right-handed neutrino is centered around the value of the scale of B - L breaking in the SO(10) gauge theory with Pati-Salam intermediate symmetry. |
2002.07038 | Elena Accomando | E. Accomando, M. Chapman, A. Maury and S. Moretti | Below-threshold CP-odd Higgs boson search via A -> Z* h at the LHC | 8 pages, 4 figures. arXiv admin note: text overlap with
arXiv:1905.07313 | Published in Phys.Lett.B 818(2021)136342 | 10.1016/j.physletb.2021.136342 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the process q q, g g -> A -> Z* h in a 2-Higgs Doublet Model Type-II
where the mass of the CP-odd Higgs state A is lower than the rest mass of the Z
and h particles (the latter being the Standard Model-like Higgs state), i.e.,
mA < mZ + mh = 215 GeV. This is a mass range which is not being currently
tested by ATLAS and CMS in this channel, yet we show that there can be
sensitivity to it already during Runs 2 and 3, assuming leptonic decays of the
gauge boson and bottom-antibottom quark ones for the Higgs boson.
| [
{
"created": "Thu, 13 Feb 2020 22:43:21 GMT",
"version": "v1"
},
{
"created": "Thu, 7 Oct 2021 08:49:17 GMT",
"version": "v2"
}
] | 2021-10-08 | [
[
"Accomando",
"E.",
""
],
[
"Chapman",
"M.",
""
],
[
"Maury",
"A.",
""
],
[
"Moretti",
"S.",
""
]
] | We study the process q q, g g -> A -> Z* h in a 2-Higgs Doublet Model Type-II where the mass of the CP-odd Higgs state A is lower than the rest mass of the Z and h particles (the latter being the Standard Model-like Higgs state), i.e., mA < mZ + mh = 215 GeV. This is a mass range which is not being currently tested by ATLAS and CMS in this channel, yet we show that there can be sensitivity to it already during Runs 2 and 3, assuming leptonic decays of the gauge boson and bottom-antibottom quark ones for the Higgs boson. |
2109.11176 | Hannah Rasmussen | Hannah Rasmussen (1), Alex McNichol (1), George M. Fuller (2), Chad T.
Kishimoto (1 and 2) ((1) Department of Physics and Biophysics, University of
San Diego, (2) Center for Astrophysics and Space Sciences, University of
California, San Diego) | Effects of an Intermediate Mass Sterile Neutrino Population on the Early
Universe | 13 pages, 11 figures | null | 10.1103/PhysRevD.105.083513 | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The hot and dense early Universe combined with the promise of high-precision
cosmological observations provide an intriguing laboratory for Beyond Standard
Model (BSM) physics. We simulate the early Universe to examine the effects of
the decay of thermally populated sterile neutrino states into Standard Model
products around the time of weak decoupling. These decays deposit a significant
amount of entropy into the plasma as well as produce a population of
high-energy out-of-equilibrium active neutrinos. As a result, we can constrain
these models by their inferred value of $N_{\rm eff}$, the effective number of
relativistic degrees of freedom. In this work, we explore a variety of models
with $N_{\rm eff}{}$ values consistent with CMB observations, but with vastly
different active neutrino spectra which will challenge the standard
cosmological model, affect lepton capture rates on free nucleons, and may
significantly affect Big Bang Nucleosynthesis (BBN).
| [
{
"created": "Thu, 23 Sep 2021 07:11:28 GMT",
"version": "v1"
}
] | 2022-05-04 | [
[
"Rasmussen",
"Hannah",
"",
"1 and 2"
],
[
"McNichol",
"Alex",
"",
"1 and 2"
],
[
"Fuller",
"George M.",
"",
"1 and 2"
],
[
"Kishimoto",
"Chad T.",
"",
"1 and 2"
]
] | The hot and dense early Universe combined with the promise of high-precision cosmological observations provide an intriguing laboratory for Beyond Standard Model (BSM) physics. We simulate the early Universe to examine the effects of the decay of thermally populated sterile neutrino states into Standard Model products around the time of weak decoupling. These decays deposit a significant amount of entropy into the plasma as well as produce a population of high-energy out-of-equilibrium active neutrinos. As a result, we can constrain these models by their inferred value of $N_{\rm eff}$, the effective number of relativistic degrees of freedom. In this work, we explore a variety of models with $N_{\rm eff}{}$ values consistent with CMB observations, but with vastly different active neutrino spectra which will challenge the standard cosmological model, affect lepton capture rates on free nucleons, and may significantly affect Big Bang Nucleosynthesis (BBN). |
1405.7662 | James Pinfold | B. Acharya, J. Alexandre, J. Bernab\'eu, M. Campbell, S. Cecchini, J.
Chwastowski, M. De Montigny, D. Derendarz, A. De Roeck, J. R. Ellis, M.
Fairbairn, D. Felea, M. Frank, D. Frekers, C. Garcia, G. Giacomelli, M.
Giorgini, D. Ha\c{S}egan, T. Hott, J. Jak\r{u}bek, A. Katre, D-W Kim, M.G.L.
King, K. Kinoshita, D. Lacarrere, S. C. Lee, C. Leroy, A. Margiotta, N.
Mauri, N. E. Mavromatos, P. Mermod, V. A. Mitsou, R. Orava, L. Pasqualini, L.
Patrizii, G. E. P\u{a}v\u{a}la\c{s}, J. L. Pinfold, M. Platkev\v{c}, V. Popa,
M. Pozzato, S. Pospisil, A. Rajantie, Z. Sahnoun, M. Sakellariadou, S.
Sarkar, G. Semenoff, G. Sirri, K. Sliwa, R. Soluk, M. Spurio, Y.N.
Srivastava, R. Staszewski, J. Swain, M. Tenti, V. Togo, M. Trzebinski, J. A.
Tuszy\'nski, V. Vento, O. Vives, Z. Vykydal, and A. Widom, J. H. Yoon | The Physics Programme Of The MoEDAL Experiment At The LHC | null | Int.J.Mod.Phys. A29 (2014) 1430050 | 10.1142/S0217751X14300506 | KCL-PH-TH/2014-02, LCTS/2014-02, CERN-PH-TH/2014-021, IFIC/14-16,
Imperial/TP/2014/AR/1 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The MoEDAL experiment at Point 8 of the LHC ring is the seventh and newest
LHC experiment. It is dedicated to the search for highly ionizing particle
avatars of physics beyond the Standard Model, extending significantly the
discovery horizon of the LHC. A MoEDAL discovery would have revolutionary
implications for our fundamental understanding of the Microcosm. MoEDAL is an
unconventional and largely passive LHC detector comprised of the largest array
of Nuclear Track Detector stacks ever deployed at an accelerator, surrounding
the intersection region at Point 8 on the LHC ring. Another novel feature is
the use of paramagnetic trapping volumes to capture both electrically and
magnetically charged highly-ionizing particles predicted in new physics
scenarios. It includes an array of TimePix pixel devices for monitoring
highly-ionizing particle backgrounds. The main passive elements of the MoEDAL
detector do not require a trigger system, electronic readout, or online
computerized data acquisition. The aim of this paper is to give an overview of
the MoEDAL physics reach, which is largely complementary to the programs of the
large multi-purpose LHC detectors ATLAS and CMS.
| [
{
"created": "Thu, 29 May 2014 19:16:21 GMT",
"version": "v1"
},
{
"created": "Tue, 15 Jul 2014 19:55:06 GMT",
"version": "v2"
},
{
"created": "Sat, 26 Jul 2014 20:15:55 GMT",
"version": "v3"
},
{
"created": "Thu, 28 Aug 2014 19:16:01 GMT",
"version": "v4"
}
] | 2020-02-06 | [
[
"Acharya",
"B.",
""
],
[
"Alexandre",
"J.",
""
],
[
"Bernabéu",
"J.",
""
],
[
"Campbell",
"M.",
""
],
[
"Cecchini",
"S.",
""
],
[
"Chwastowski",
"J.",
""
],
[
"De Montigny",
"M.",
""
],
[
"Derendarz... | The MoEDAL experiment at Point 8 of the LHC ring is the seventh and newest LHC experiment. It is dedicated to the search for highly ionizing particle avatars of physics beyond the Standard Model, extending significantly the discovery horizon of the LHC. A MoEDAL discovery would have revolutionary implications for our fundamental understanding of the Microcosm. MoEDAL is an unconventional and largely passive LHC detector comprised of the largest array of Nuclear Track Detector stacks ever deployed at an accelerator, surrounding the intersection region at Point 8 on the LHC ring. Another novel feature is the use of paramagnetic trapping volumes to capture both electrically and magnetically charged highly-ionizing particles predicted in new physics scenarios. It includes an array of TimePix pixel devices for monitoring highly-ionizing particle backgrounds. The main passive elements of the MoEDAL detector do not require a trigger system, electronic readout, or online computerized data acquisition. The aim of this paper is to give an overview of the MoEDAL physics reach, which is largely complementary to the programs of the large multi-purpose LHC detectors ATLAS and CMS. |
0901.3164 | Matthew Sexton | Matthew G. Sexton (Minnesota U.) | The evolution and decay of supersymmetric flat directions in the early
universe and their role in thermalizing the universe | 193 Pages, Ph. D. Thesis | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | I study the post-inflation oscillation and decay of light coherent scalar
field condensates that may develop during an inflationary phase of the
universe. In particular, the light scalars studied are a composition of the
scalar particles of a supersymmetric theory which correspond to the flat
directions of the theory's scalar potential. Some toy models that possess
supersymmetric flat directions are presented and numerical solutions for the
evolution of the scalar fields are obtained. Both analytic and numeric results
suggest that such condensates, if they existed in the early universe, can decay
through a rapid and nonperturbative process long before these condensates could
significantly affect the thermalization of the universe.
| [
{
"created": "Wed, 21 Jan 2009 16:49:32 GMT",
"version": "v1"
}
] | 2009-01-22 | [
[
"Sexton",
"Matthew G.",
"",
"Minnesota U."
]
] | I study the post-inflation oscillation and decay of light coherent scalar field condensates that may develop during an inflationary phase of the universe. In particular, the light scalars studied are a composition of the scalar particles of a supersymmetric theory which correspond to the flat directions of the theory's scalar potential. Some toy models that possess supersymmetric flat directions are presented and numerical solutions for the evolution of the scalar fields are obtained. Both analytic and numeric results suggest that such condensates, if they existed in the early universe, can decay through a rapid and nonperturbative process long before these condensates could significantly affect the thermalization of the universe. |
1310.8448 | Bronislav Zakharov | B.G. Zakharov | Jet tomography of AA-collisions at RHIC and LHC energies | 4 pages, 4 figures, talk presented at 48th Rencontres de Moriond on
QCD and Hadronic Interactions, La Thuile, Italy, 9-16 Mar 2013 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present our recent results on jet tomography of AA-collisions at RHIC and
LHC. We focus on flavor dependence of the nuclear modification factor. The
computations are performed accounting for radiative and collisional parton
energy loss with running coupling constant.
| [
{
"created": "Thu, 31 Oct 2013 10:23:18 GMT",
"version": "v1"
}
] | 2013-11-01 | [
[
"Zakharov",
"B. G.",
""
]
] | We present our recent results on jet tomography of AA-collisions at RHIC and LHC. We focus on flavor dependence of the nuclear modification factor. The computations are performed accounting for radiative and collisional parton energy loss with running coupling constant. |
2106.06207 | Stefano Scopel | Injun Jeong, Sunghyun Kang, Stefano Scopel (Sogang U.), Gaurav Tomar
(Technical U. of Munich) | WimPyDD: an object-oriented Python code for the calculation of WIMP
direct detection signals | 33 pages, 4 figure, 4 tables. WimPyDD can be downloaded from
https://wimpydd.hepforge.org/ | null | 10.1016/j.cpc.2022.108342 | CQUeST-2021-0663, TUM-HEP 1343/21 | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We introduce WimPyDD, a modular, object-oriented and customizable Python code
that calculates accurate predictions for the expected rates in Weakly
Interacting Massive Particle (WIMP) direct-detection experiments within the
framework of Galilean-invariant non-relativistic effective theory in virtually
any scenario, including inelastic scattering, an arbitrary WIMP spin and a
generic WIMP velocity distribution in the Galactic halo. WimPyDD exploits the
factorization of the three main components that enter in the calculation of
direct detection signals: i) the Wilson coefficients that encode the dependence
of the signals on the ultraviolet completion of the effective theory; ii) a
response function that depends on the nuclear physics and on the main features
of the experimental detector (acceptance, energy resolution, response to
nuclear recoils); iii) a halo function that depends on the WIMP velocity
distribution and that encodes the astrophysical inputs. In WimPyDD these three
components are calculated and stored separately for later interpolation and
combined together only as the last step of the signal evaluation procedure.
This makes the phenomenological study of the direct detection scattering rate
with WimPyDD transparent and fast also when the parameter space of the WIMP
model has a large dimensionality.
| [
{
"created": "Fri, 11 Jun 2021 07:27:58 GMT",
"version": "v1"
}
] | 2022-04-13 | [
[
"Jeong",
"Injun",
"",
"Sogang U."
],
[
"Kang",
"Sunghyun",
"",
"Sogang U."
],
[
"Scopel",
"Stefano",
"",
"Sogang U."
],
[
"Tomar",
"Gaurav",
"",
"Technical U. of Munich"
]
] | We introduce WimPyDD, a modular, object-oriented and customizable Python code that calculates accurate predictions for the expected rates in Weakly Interacting Massive Particle (WIMP) direct-detection experiments within the framework of Galilean-invariant non-relativistic effective theory in virtually any scenario, including inelastic scattering, an arbitrary WIMP spin and a generic WIMP velocity distribution in the Galactic halo. WimPyDD exploits the factorization of the three main components that enter in the calculation of direct detection signals: i) the Wilson coefficients that encode the dependence of the signals on the ultraviolet completion of the effective theory; ii) a response function that depends on the nuclear physics and on the main features of the experimental detector (acceptance, energy resolution, response to nuclear recoils); iii) a halo function that depends on the WIMP velocity distribution and that encodes the astrophysical inputs. In WimPyDD these three components are calculated and stored separately for later interpolation and combined together only as the last step of the signal evaluation procedure. This makes the phenomenological study of the direct detection scattering rate with WimPyDD transparent and fast also when the parameter space of the WIMP model has a large dimensionality. |
2402.07993 | Vaisakh Plakkot | W. Dekens, J. de Vries, D. Castillo, J. Men\'endez, E. Mereghetti, V.
Plakkot, P. Soriano, G. Zhou | Neutrinoless double beta decay rates in the presence of light sterile
neutrinos | null | null | null | LA-UR-24-21117, INT-PUB-24-007 | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate neutrinoless double-beta decay ($0\nu\beta\beta$) in minimal
extensions of the Standard Model of particle physics where gauge-singlet
right-handed neutrinos give rise to Dirac and Majorana neutrino mass terms. We
argue that the standard treatment of these scenarios, based on mass-dependent
nuclear matrix elements, is missing important contributions to the
$0\nu\beta\beta$ amplitude. First, new effects arise from the exchange of
neutrinos with very small (ultrasoft) momenta, for which we compute the
associated nuclear matrix elements for the decays of ${}^{76}$Ge and
${}^{136}$Xe. These contributions can dominate the $0\nu\beta\beta$ rate in
cases with light sterile neutrinos. The ultrasoft terms are also relevant in
the more standard scenario of just three light Majorana neutrinos where they
lead to a $10\%$ reduction of the total $0\nu\beta\beta$ amplitude. Secondly,
we highlight the importance of short-range terms associated with medium-heavy
sterile neutrinos and provide explicit formulae that can be used in
phenomenological analyses. As examples we discuss impact of these new effects
in several explicit scenarios, including a realistic $3+2$ model with two
right-handed gauge-singlet neutrinos.
| [
{
"created": "Mon, 12 Feb 2024 19:01:08 GMT",
"version": "v1"
}
] | 2024-02-14 | [
[
"Dekens",
"W.",
""
],
[
"de Vries",
"J.",
""
],
[
"Castillo",
"D.",
""
],
[
"Menéndez",
"J.",
""
],
[
"Mereghetti",
"E.",
""
],
[
"Plakkot",
"V.",
""
],
[
"Soriano",
"P.",
""
],
[
"Zhou",
"G.",
... | We investigate neutrinoless double-beta decay ($0\nu\beta\beta$) in minimal extensions of the Standard Model of particle physics where gauge-singlet right-handed neutrinos give rise to Dirac and Majorana neutrino mass terms. We argue that the standard treatment of these scenarios, based on mass-dependent nuclear matrix elements, is missing important contributions to the $0\nu\beta\beta$ amplitude. First, new effects arise from the exchange of neutrinos with very small (ultrasoft) momenta, for which we compute the associated nuclear matrix elements for the decays of ${}^{76}$Ge and ${}^{136}$Xe. These contributions can dominate the $0\nu\beta\beta$ rate in cases with light sterile neutrinos. The ultrasoft terms are also relevant in the more standard scenario of just three light Majorana neutrinos where they lead to a $10\%$ reduction of the total $0\nu\beta\beta$ amplitude. Secondly, we highlight the importance of short-range terms associated with medium-heavy sterile neutrinos and provide explicit formulae that can be used in phenomenological analyses. As examples we discuss impact of these new effects in several explicit scenarios, including a realistic $3+2$ model with two right-handed gauge-singlet neutrinos. |
hep-ph/0012286 | Tsou Sheung Tsun | HM Chan (Rutherford Appleton Lab) | Experimental implications of the dual colour solution to the generation
puzzle | 3 pages, latex, uses ltwol.sty included, invited lecture at the 3rd
Joint Meeting of Chinese Physicists Worldwide, Hong Kong, August 2000 | null | null | null | hep-ph | null | Apart from offering explanations not only for the distinctive fermion mass
and mixing patterns but also for the actual values of the mass and mixing
parameters, the dual colour solution to the generation puzzle gives numerous
detailed predictions ranging from rare FCNC meson decays and $\mu$-$e$
conversions in nuclei at low energies to cosmic ray air showers with energies
beyond $10^{20}$ eV at the extreme end of the experimental range. Besides, it
predicts a new class of flavour-violating phenomena (called transmutations) due
to the rotating fermion mass matrix which are unambiguously calculable.
Comparison with experiment of these many ``parameter-free'' predictions reveals
no violation of existing bounds but identifies several striking effects which
can be tested with present experimental sensitivity.
| [
{
"created": "Thu, 21 Dec 2000 12:56:30 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Chan",
"HM",
"",
"Rutherford Appleton Lab"
]
] | Apart from offering explanations not only for the distinctive fermion mass and mixing patterns but also for the actual values of the mass and mixing parameters, the dual colour solution to the generation puzzle gives numerous detailed predictions ranging from rare FCNC meson decays and $\mu$-$e$ conversions in nuclei at low energies to cosmic ray air showers with energies beyond $10^{20}$ eV at the extreme end of the experimental range. Besides, it predicts a new class of flavour-violating phenomena (called transmutations) due to the rotating fermion mass matrix which are unambiguously calculable. Comparison with experiment of these many ``parameter-free'' predictions reveals no violation of existing bounds but identifies several striking effects which can be tested with present experimental sensitivity. |
hep-ph/9603278 | Ulf Meissner | V. Bernard, N. Kaiser and Ulf-G. Mei{\ss}ner | Chiral corrections to the Kroll-Ruderman theorem | 7 pp, LaTeX | Phys.Lett. B383 (1996) 116-120 | 10.1016/0370-2693(96)00699-5 | CRN 96-10 and TK 96 08 | hep-ph nucl-th | null | We calculate the one--loop corrections to the Kroll--Ruderman low--energy
theorems for charged pion photoproduction in the framework of heavy baryon
chiral perturbation theory. We predict the threshold S--wave multipole $E_{0+}$
to be $E_{0+}^{\rm thr}(\gamma p \to \pi^+ n) = ( 28.2 \pm 0.6 )\cdot
10^{-3}/M_{\pi}$ and $E_{0+}^{\rm thr} (\gamma n \to\pi^- p) = ( -32.7 \pm 0.6
)\cdot 10^{-3}/M_{\pi}$, respectively, for a fixed pion--nucleon coupling
constant, $g_{\pi N} = 13.4$. A comparison to the existing data is also given.
| [
{
"created": "Tue, 12 Mar 1996 11:46:10 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Bernard",
"V.",
""
],
[
"Kaiser",
"N.",
""
],
[
"Meißner",
"Ulf-G.",
""
]
] | We calculate the one--loop corrections to the Kroll--Ruderman low--energy theorems for charged pion photoproduction in the framework of heavy baryon chiral perturbation theory. We predict the threshold S--wave multipole $E_{0+}$ to be $E_{0+}^{\rm thr}(\gamma p \to \pi^+ n) = ( 28.2 \pm 0.6 )\cdot 10^{-3}/M_{\pi}$ and $E_{0+}^{\rm thr} (\gamma n \to\pi^- p) = ( -32.7 \pm 0.6 )\cdot 10^{-3}/M_{\pi}$, respectively, for a fixed pion--nucleon coupling constant, $g_{\pi N} = 13.4$. A comparison to the existing data is also given. |
hep-ph/9405214 | Martin B. Einhorn | C. Arzt, M.B. Einhorn, and J. Wudka | Patterns of Deviation from the Standard Model | 37 pages, UM-TH-94-15. Four figures and one table are embedded in
text. This file requires as inputs epsf.tex and the IAS version of
phyzzx.tex. The complete manuscript is available as a postscript file via
anonymous FTP to williams.physics.lsa.umich.edu. It is called deviation.ps in
the /pub subdirectory. (Modified to add a table and to make minor
corrections.) | Nucl.Phys. B433 (1995) 41-66 | 10.1016/0550-3213(94)00336-D | null | hep-ph | null | Effective Lagrangians can be used to parametrize the effects of physics
beyond the standard model. Assuming the complete theory is a gauge theory, we
determine which effective operators may be generated at tree level, and which
are only generated at loop level. The latter are be suppressed by factors of
$1/ 16\pi^2$ and will therefore be quite difficult to detect. In particular,
all operators changing the Standard-Model structure of the triple-gauge-vector
couplings fall into this category. We also point out that in certain cases,
dimension-eight operators may be more important than dimension-six operators.
We discuss both the linear and non-linear representation of the Higgs sector.
| [
{
"created": "Tue, 3 May 1994 17:36:05 GMT",
"version": "v1"
},
{
"created": "Thu, 5 May 1994 14:40:24 GMT",
"version": "v2"
},
{
"created": "Fri, 13 May 1994 21:41:55 GMT",
"version": "v3"
},
{
"created": "Tue, 17 May 1994 10:55:06 GMT",
"version": "v4"
},
{
"cre... | 2009-10-28 | [
[
"Arzt",
"C.",
""
],
[
"Einhorn",
"M. B.",
""
],
[
"Wudka",
"J.",
""
]
] | Effective Lagrangians can be used to parametrize the effects of physics beyond the standard model. Assuming the complete theory is a gauge theory, we determine which effective operators may be generated at tree level, and which are only generated at loop level. The latter are be suppressed by factors of $1/ 16\pi^2$ and will therefore be quite difficult to detect. In particular, all operators changing the Standard-Model structure of the triple-gauge-vector couplings fall into this category. We also point out that in certain cases, dimension-eight operators may be more important than dimension-six operators. We discuss both the linear and non-linear representation of the Higgs sector. |
0902.4601 | Eugene Zabrodin | E. Zabrodin, I.C. Arsene, J. Bleibel, M. Bleicher, L.V. Bravina, G.
Burau, Amand Faessler, C. Fuchs, M.S. Nilsson, K. Tywoniuk, H. Stoecker | Equation of state at FAIR energies and the role of resonances | SQM2008 proceedings, 6 pages | J.Phys.G36:064065,2009 | 10.1088/0954-3899/36/6/064065 | null | hep-ph nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Two microscopic models, UrQMD and QGSM, are used to extract the effective
equation of state (EOS) of locally equilibrated nuclear matter produced in
heavy-ion collisions at energies from 11.6 AGeV to 160 AGeV. Analysis is
performed for the fixed central cubic cell of volume V = 125 fm**3 and for the
expanding cell that followed the growth of the central area with uniformly
distributed energy. For all reactions the state of local equilibrium is nearly
approached in both models after a certain relaxation period. The EOS has a
simple linear dependence P/e = c_s**2 with 0.12 < c_s**2 < 0.145. Heavy
resonances are shown to be responsible for deviations of the c_s**2(T) and
c_s**2(mu_B) from linear behavior. In the T-mu_B and T-mu_S planes the EOS has
also almost linear dependence and demonstrates kinks related not to the
deconfinement phase transition but to inelastic freeze-out in the system.
| [
{
"created": "Thu, 26 Feb 2009 14:57:51 GMT",
"version": "v1"
}
] | 2010-01-15 | [
[
"Zabrodin",
"E.",
""
],
[
"Arsene",
"I. C.",
""
],
[
"Bleibel",
"J.",
""
],
[
"Bleicher",
"M.",
""
],
[
"Bravina",
"L. V.",
""
],
[
"Burau",
"G.",
""
],
[
"Faessler",
"Amand",
""
],
[
"Fuchs",
"... | Two microscopic models, UrQMD and QGSM, are used to extract the effective equation of state (EOS) of locally equilibrated nuclear matter produced in heavy-ion collisions at energies from 11.6 AGeV to 160 AGeV. Analysis is performed for the fixed central cubic cell of volume V = 125 fm**3 and for the expanding cell that followed the growth of the central area with uniformly distributed energy. For all reactions the state of local equilibrium is nearly approached in both models after a certain relaxation period. The EOS has a simple linear dependence P/e = c_s**2 with 0.12 < c_s**2 < 0.145. Heavy resonances are shown to be responsible for deviations of the c_s**2(T) and c_s**2(mu_B) from linear behavior. In the T-mu_B and T-mu_S planes the EOS has also almost linear dependence and demonstrates kinks related not to the deconfinement phase transition but to inelastic freeze-out in the system. |
hep-ph/0501289 | Martin Beneke | M. Beneke, Y. Kiyo, K. Schuller (RWTH Aachen) | Third-order Coulomb corrections to the S-wave Green function, energy
levels and wave functions at the origin | 24 pages, LaTeX, v2: eq.(30) corrected (-13/8->-15/8) | Nucl.Phys.B714:67-90,2005 | 10.1016/j.nuclphysb.2005.02.028 | PITHA 05/01 | hep-ph | null | We obtain analytic expressions for the third-order corrections due to the
strong interaction Coulomb potential to the S-wave Green function, energy
levels and wave functions at the origin for arbitrary principal quantum number
n. Together with the known non-Coulomb correction this results in the complete
spectrum of S-states up to order alpha_s^5. The numerical impact of these
corrections on the Upsilon spectrum and the top quark pair production cross
section near threshold is estimated.
| [
{
"created": "Mon, 31 Jan 2005 15:12:33 GMT",
"version": "v1"
},
{
"created": "Wed, 30 May 2007 15:19:30 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Beneke",
"M.",
"",
"RWTH Aachen"
],
[
"Kiyo",
"Y.",
"",
"RWTH Aachen"
],
[
"Schuller",
"K.",
"",
"RWTH Aachen"
]
] | We obtain analytic expressions for the third-order corrections due to the strong interaction Coulomb potential to the S-wave Green function, energy levels and wave functions at the origin for arbitrary principal quantum number n. Together with the known non-Coulomb correction this results in the complete spectrum of S-states up to order alpha_s^5. The numerical impact of these corrections on the Upsilon spectrum and the top quark pair production cross section near threshold is estimated. |
1811.05263 | Juergen Reuter | J\"urgen Reuter | The Role of Positron Polarization for the initial 250 GeV stage of the
ILC | 4 pages, to be submitted to proceedings of ICHEP 2018, presented on
behalf of the Physics Working Group of the LCC Collaboration | null | null | DESY 18-193 | hep-ph hep-ex physics.ins-det | http://creativecommons.org/licenses/by/4.0/ | The International Linear Collider is now proposed with a staged machine
design, with the first stage at $\sqrt{s}=250$ GeV and an integrated luminosity
goal of 2 ab${}^{-1}$. One of the questions for the machine design is the
importance of positron polarization. In this report, we review the impact of
positron polarization on the physics goals of the 250 GeV stage of the ILC and
demonstrate that positron polarization has distinct advantages.
| [
{
"created": "Tue, 13 Nov 2018 12:47:16 GMT",
"version": "v1"
}
] | 2018-11-14 | [
[
"Reuter",
"Jürgen",
""
]
] | The International Linear Collider is now proposed with a staged machine design, with the first stage at $\sqrt{s}=250$ GeV and an integrated luminosity goal of 2 ab${}^{-1}$. One of the questions for the machine design is the importance of positron polarization. In this report, we review the impact of positron polarization on the physics goals of the 250 GeV stage of the ILC and demonstrate that positron polarization has distinct advantages. |
1011.6163 | Stefan Liebler | Stefan Liebler, Werner Porod | Electroweak corrections to Neutralino and Chargino decays into a W-boson
in the (N)MSSM | 42 pages, 15 figures; discussion of on-shell masses added,
renormalization of the electric charge and Bremsstrahlung integrals
corrected, published in Nuclear Physics B | Nucl.Phys. B849 (2011) 213-249, Erratum-ibid. B856 (2012) 125-127 | 10.1016/j.nuclphysb.2011.03.018 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the complete electroweak one-loop corrections to the partial
widths for two-body decays of a chargino (neutralino) into a W-boson and a
neutralino (chargino). We perform the calculation for the minimal and the
next-to-minimal supersymmetric standard model using an on-shell renormalization
scheme. Particular attention is paid to the question of gauge invariance which
is achieved using the so-called pinch technique. Furthermore we show that these
corrections show a strong parameter dependence and usually are in the range of
1-10 percent if the neutralino involved is a higgsino or wino like state.
However, in case of a bino-like or a singlino-like neutralino the corrections
can go up to 50% and more. Moreover we present the public program CNNDecays
performing these calculations.
| [
{
"created": "Mon, 29 Nov 2010 09:32:27 GMT",
"version": "v1"
},
{
"created": "Fri, 15 Apr 2011 08:24:30 GMT",
"version": "v2"
},
{
"created": "Tue, 6 Dec 2011 16:30:29 GMT",
"version": "v3"
}
] | 2015-03-17 | [
[
"Liebler",
"Stefan",
""
],
[
"Porod",
"Werner",
""
]
] | We present the complete electroweak one-loop corrections to the partial widths for two-body decays of a chargino (neutralino) into a W-boson and a neutralino (chargino). We perform the calculation for the minimal and the next-to-minimal supersymmetric standard model using an on-shell renormalization scheme. Particular attention is paid to the question of gauge invariance which is achieved using the so-called pinch technique. Furthermore we show that these corrections show a strong parameter dependence and usually are in the range of 1-10 percent if the neutralino involved is a higgsino or wino like state. However, in case of a bino-like or a singlino-like neutralino the corrections can go up to 50% and more. Moreover we present the public program CNNDecays performing these calculations. |
hep-ph/9603201 | Jes Madsen | Steen Hannestad and Jes Madsen (University of Aarhus, Denmark) | Nucleosynthesis and the mass of the tau neutrino | 10 pages (REVTeX), 4 ps figures. To appear in Physical Review Letters | Phys.Rev.Lett.76:2848-2851,1996; Erratum-ibid.77:5148,1996 | 10.1103/PhysRevLett.76.2848 | null | hep-ph astro-ph | null | The primordial abundance of long-lived heavy Majorana neutrinos is calculated
from the full Boltzmann equation. Inclusion of scattering reactions drastically
change the predicted abundance of a heavy neutrino species. This loosens the
well known mass constraint on MeV neutrinos from Big Bang nucleosynthesis, and
allows for the existence of a Majorana tau neutrino with mass m > 11 MeV.
Further experimental efforts are therefore needed to investigate the range 11
MeV < m < 24 MeV. Some interesting cosmological consequences of an MeV nu_tau
are also pointed out.
| [
{
"created": "Fri, 1 Mar 1996 09:10:54 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Hannestad",
"Steen",
"",
"University of Aarhus, Denmark"
],
[
"Madsen",
"Jes",
"",
"University of Aarhus, Denmark"
]
] | The primordial abundance of long-lived heavy Majorana neutrinos is calculated from the full Boltzmann equation. Inclusion of scattering reactions drastically change the predicted abundance of a heavy neutrino species. This loosens the well known mass constraint on MeV neutrinos from Big Bang nucleosynthesis, and allows for the existence of a Majorana tau neutrino with mass m > 11 MeV. Further experimental efforts are therefore needed to investigate the range 11 MeV < m < 24 MeV. Some interesting cosmological consequences of an MeV nu_tau are also pointed out. |
hep-ph/0007163 | Massimo Giovannini | Massimo Giovannini (Institute for Theoretical Physics, Lausanne
University) | Magnetogenesis and the dynamics of internal dimensions | 27 in RevTex style, four figures | Phys.Rev. D62 (2000) 123505 | 10.1103/PhysRevD.62.123505 | UNIL-IPT-00-16, June 2000 | hep-ph astro-ph | null | The dynamical evolution of internal space-like dimensions breaks the
invariance of the Maxwell's equations under Weyl rescaling of the (conformally
flat) four-dimensional metric. Depending upon the number and upon the dynamics
of internal dimensions large scale magnetic fields can be created. The
requirements coming from magnetogenesis together with the other cosmological
constraints are examined under the assumption that the internal dimensions
either grow or shrink (in conformal time) prior to a radiation dominated epoch.
If the internal dimensions are growing the magnitude of the generated magnetic
fields can seed the galactic dynamo mechanism.
| [
{
"created": "Sat, 15 Jul 2000 20:06:48 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Giovannini",
"Massimo",
"",
"Institute for Theoretical Physics, Lausanne\n University"
]
] | The dynamical evolution of internal space-like dimensions breaks the invariance of the Maxwell's equations under Weyl rescaling of the (conformally flat) four-dimensional metric. Depending upon the number and upon the dynamics of internal dimensions large scale magnetic fields can be created. The requirements coming from magnetogenesis together with the other cosmological constraints are examined under the assumption that the internal dimensions either grow or shrink (in conformal time) prior to a radiation dominated epoch. If the internal dimensions are growing the magnitude of the generated magnetic fields can seed the galactic dynamo mechanism. |
hep-ph/0207201 | T. Becher | Thomas Becher and Kirill Melnikov | The Asymptotic Expansion of Lattice Loop Integrals Around the Continuum
Limit | 9 pages, 2 figures | Phys.Rev. D66 (2002) 074508 | 10.1103/PhysRevD.66.074508 | SLAC-PUB-9296 | hep-ph hep-lat | null | We present a method of computing any one-loop integral in lattice
perturbation theory by systematically expanding around its continuum limit. At
any order in the expansion in the lattice spacing, the result can be written as
a sum of continuum loop integrals in analytic regularization and a few genuine
lattice integrals (``master integrals''). These lattice master integrals are
independent of external momenta and masses and can be computed numerically. At
the one-loop level, there are four master integrals in a theory with only
bosonic fields, seven in HQET and sixteen in QED or QCD with Wilson fermions.
| [
{
"created": "Wed, 17 Jul 2002 00:53:17 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Becher",
"Thomas",
""
],
[
"Melnikov",
"Kirill",
""
]
] | We present a method of computing any one-loop integral in lattice perturbation theory by systematically expanding around its continuum limit. At any order in the expansion in the lattice spacing, the result can be written as a sum of continuum loop integrals in analytic regularization and a few genuine lattice integrals (``master integrals''). These lattice master integrals are independent of external momenta and masses and can be computed numerically. At the one-loop level, there are four master integrals in a theory with only bosonic fields, seven in HQET and sixteen in QED or QCD with Wilson fermions. |
1806.06220 | Mario E. Gomez | M.E. Gomez, S. Lola, R. Ruiz de Austri, Q. Shafi | Dark Matter, Sparticle Spectroscopy and Muon $(g-2)$ in $SU(4)_c \times
SU(2)_L \times SU(2)_R$ | 21 pages, 8 figs | null | 10.1007/JHEP10(2018)062 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We explore the sparticle mass spectra including LSP dark matter within the
framework of supersymmetric $SU(4)_c \times SU(2)_L \times SU(2)_R$ (422)
models, taking into account the constraints from extensive LHC and cold dark
matter searches. The soft supersymmetry-breaking parameters at $M_{GUT}$ can be
non-universal, but consistent with the 422 symmetry. We identify a variety of
coannihilation scenarios compatible with LSP dark matter, and study the
implications for future supersymmetry searches and the ongoing muon g-2
experiment.
| [
{
"created": "Sat, 16 Jun 2018 10:50:29 GMT",
"version": "v1"
}
] | 2018-11-14 | [
[
"Gomez",
"M. E.",
""
],
[
"Lola",
"S.",
""
],
[
"de Austri",
"R. Ruiz",
""
],
[
"Shafi",
"Q.",
""
]
] | We explore the sparticle mass spectra including LSP dark matter within the framework of supersymmetric $SU(4)_c \times SU(2)_L \times SU(2)_R$ (422) models, taking into account the constraints from extensive LHC and cold dark matter searches. The soft supersymmetry-breaking parameters at $M_{GUT}$ can be non-universal, but consistent with the 422 symmetry. We identify a variety of coannihilation scenarios compatible with LSP dark matter, and study the implications for future supersymmetry searches and the ongoing muon g-2 experiment. |
1611.09237 | Ferruccio Feruglio | Ferruccio Feruglio | Aspects of Leptonic Flavour Mixing | Talk given at Neutrino 2016 (London, 4-9 July 2016) and Now 2016
(Otranto, 4-11 September 2016) | null | 10.1088/1742-6596/888/1/012026 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Since the discovery of neutrino oscillations many ideas have been put forward
to explain the special features of the leptonic mixing and the differences with
respect to the quark sector. In this talk I review some of these proposals,
emphasizing especially their predictability. In the light of the new data, I
first revisit fixed-point relations among mixing angles and phases. Then I
briefly comment on radiative neutrino masses. Finally I discuss the role of
flavour symmetries. Given the very many existing models I focus on two classes
of models. On the one hand I illustrate the ability of models based on a
generalization of the anarchy idea in reproducing the main features of both the
quark and the lepton spectrum, also in a GUT framework. On the other hand I
discuss less ambitious but more predictive models based on discrete flavour
symmetries, centered on the properties of the leptonic mixing matrix.
| [
{
"created": "Mon, 28 Nov 2016 16:52:17 GMT",
"version": "v1"
}
] | 2017-10-11 | [
[
"Feruglio",
"Ferruccio",
""
]
] | Since the discovery of neutrino oscillations many ideas have been put forward to explain the special features of the leptonic mixing and the differences with respect to the quark sector. In this talk I review some of these proposals, emphasizing especially their predictability. In the light of the new data, I first revisit fixed-point relations among mixing angles and phases. Then I briefly comment on radiative neutrino masses. Finally I discuss the role of flavour symmetries. Given the very many existing models I focus on two classes of models. On the one hand I illustrate the ability of models based on a generalization of the anarchy idea in reproducing the main features of both the quark and the lepton spectrum, also in a GUT framework. On the other hand I discuss less ambitious but more predictive models based on discrete flavour symmetries, centered on the properties of the leptonic mixing matrix. |
0809.2441 | Chung-Lin Shan | Manuel Drees, Chung-Lin Shan | Constraining the Spin-Independent WIMP-Nucleon Coupling from Direct Dark
Matter Detection Data | 5 pages, 4 figures, plots updated, to appear in the proceedings of
Identification of Dark Matter (IDM 2008), Stockholm, Sweden, 18-22 August,
2008 | PoS idm2008:110,2008 | null | null | hep-ph astro-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Weakly Interacting Massive Particles (WIMPs) are one of the leading
candidates for Dark Matter. For understanding the properties of WIMPs and
identifying them among new particles produced at colliders (hopefully in the
near future), determinations of their mass and their couplings on nucleons from
direct Dark Matter detection experiments are essential. Based on our method for
determining the WIMP mass model-independently from experimental data, we
present a way to also estimate the spin-independent (SI) WIMP-nucleon coupling
by using measured recoil energies directly. This method isindependent of the as
yet unknown velocity distribution of halo WIMPs. In spite of the uncertainty of
the local WIMP density (of a factor of ~ 2), at least an upper limit on the SI
WIMP-nucleon coupling could be given, once two (or more) experiments with
different target nuclei obtain positive signals. In a background-free
environment, for a WIMP mass of 100 GeV its SI coupling on nucleons could in
principle be estimated with a statistical error of only ~ 15% with just 50
events from each experiment.
| [
{
"created": "Mon, 15 Sep 2008 04:27:13 GMT",
"version": "v1"
},
{
"created": "Thu, 19 Mar 2009 10:21:38 GMT",
"version": "v2"
}
] | 2010-02-17 | [
[
"Drees",
"Manuel",
""
],
[
"Shan",
"Chung-Lin",
""
]
] | Weakly Interacting Massive Particles (WIMPs) are one of the leading candidates for Dark Matter. For understanding the properties of WIMPs and identifying them among new particles produced at colliders (hopefully in the near future), determinations of their mass and their couplings on nucleons from direct Dark Matter detection experiments are essential. Based on our method for determining the WIMP mass model-independently from experimental data, we present a way to also estimate the spin-independent (SI) WIMP-nucleon coupling by using measured recoil energies directly. This method isindependent of the as yet unknown velocity distribution of halo WIMPs. In spite of the uncertainty of the local WIMP density (of a factor of ~ 2), at least an upper limit on the SI WIMP-nucleon coupling could be given, once two (or more) experiments with different target nuclei obtain positive signals. In a background-free environment, for a WIMP mass of 100 GeV its SI coupling on nucleons could in principle be estimated with a statistical error of only ~ 15% with just 50 events from each experiment. |
1211.0999 | Shehu AbdusSalam | Shehu S. AbdusSalam | LHC-7 supersymmetry search interpretation within the pMSSM | 11 pages, 2 figures | null | 10.1103/PhysRevD.87.115012 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The ATLAS collaboration published supersymmetry limits based on up to about
4.7 \ifb data collected over the year 2011 from LHC runs at 7 TeV. These were
mainly interpreted within restricted, particular or simplified models for
supersymmetry breaking schemes or scenarios. The pMSSM is an alternative and
more generic supersymmetry framework which captures broader phenomenological
features. Searching for more generic conclusions from the supersymmetry limits
interpretation, we update a Bayesian global fit of the pMSSM to pre-LHC data
using the LHC-7 limits. The posterior distributions show the most up to date
features, revealing allowed versus excluded regions in sparticle mass planes
within the MSSM.
| [
{
"created": "Mon, 5 Nov 2012 20:48:49 GMT",
"version": "v1"
}
] | 2013-06-12 | [
[
"AbdusSalam",
"Shehu S.",
""
]
] | The ATLAS collaboration published supersymmetry limits based on up to about 4.7 \ifb data collected over the year 2011 from LHC runs at 7 TeV. These were mainly interpreted within restricted, particular or simplified models for supersymmetry breaking schemes or scenarios. The pMSSM is an alternative and more generic supersymmetry framework which captures broader phenomenological features. Searching for more generic conclusions from the supersymmetry limits interpretation, we update a Bayesian global fit of the pMSSM to pre-LHC data using the LHC-7 limits. The posterior distributions show the most up to date features, revealing allowed versus excluded regions in sparticle mass planes within the MSSM. |
1201.2179 | Matthew McCullough | Nathaniel Craig, Matthew McCullough, Jesse Thaler | The New Flavor of Higgsed Gauge Mediation | 13 pages, 3 figures; v2: typos corrected, references added | null | 10.1007/JHEP03(2012)049 | MIT-CTP 4338; RU-NHETC 2011-26 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Recent LHC bounds on squark masses combined with naturalness and flavor
considerations motivate non-trivial sfermion mass spectra in the supersymmetric
Standard Model. These can arise if supersymmetry breaking is communicated to
the visible sector via new extended gauge symmetries. Such extended symmetries
must be spontaneously broken, or confined, complicating the calculation of soft
masses. We develop a new formalism for calculating perturbative gauge-mediated
two-loop soft masses for gauge groups with arbitrary patterns of spontaneous
symmetry breaking, simplifying the framework of "Higgsed gauge mediation." The
resulting expressions can be applied to Abelian and non-Abelian gauge groups,
opening new avenues for supersymmetric model building. We present a number of
examples using our method, ranging from grand unified threshold corrections in
standard gauge mediation to soft masses in gauge extensions of the Higgs sector
that can raise the Higgs mass through non-decoupling D-terms. We also outline a
new mediation mechanism called "flavor mediation", where supersymmetry breaking
is communicated via a gauged subgroup of Standard Model flavor symmetries.
Flavor mediation can automatically generate suppressed masses for
third-generation squarks and implies a nearly exact U(2) symmetry in the first
two generations, yielding a "natural SUSY" spectrum without imposing ad hoc
global symmetries or giving preferential treatment to particular generations.
| [
{
"created": "Tue, 10 Jan 2012 21:00:07 GMT",
"version": "v1"
},
{
"created": "Tue, 24 Jan 2012 20:58:54 GMT",
"version": "v2"
}
] | 2015-06-03 | [
[
"Craig",
"Nathaniel",
""
],
[
"McCullough",
"Matthew",
""
],
[
"Thaler",
"Jesse",
""
]
] | Recent LHC bounds on squark masses combined with naturalness and flavor considerations motivate non-trivial sfermion mass spectra in the supersymmetric Standard Model. These can arise if supersymmetry breaking is communicated to the visible sector via new extended gauge symmetries. Such extended symmetries must be spontaneously broken, or confined, complicating the calculation of soft masses. We develop a new formalism for calculating perturbative gauge-mediated two-loop soft masses for gauge groups with arbitrary patterns of spontaneous symmetry breaking, simplifying the framework of "Higgsed gauge mediation." The resulting expressions can be applied to Abelian and non-Abelian gauge groups, opening new avenues for supersymmetric model building. We present a number of examples using our method, ranging from grand unified threshold corrections in standard gauge mediation to soft masses in gauge extensions of the Higgs sector that can raise the Higgs mass through non-decoupling D-terms. We also outline a new mediation mechanism called "flavor mediation", where supersymmetry breaking is communicated via a gauged subgroup of Standard Model flavor symmetries. Flavor mediation can automatically generate suppressed masses for third-generation squarks and implies a nearly exact U(2) symmetry in the first two generations, yielding a "natural SUSY" spectrum without imposing ad hoc global symmetries or giving preferential treatment to particular generations. |
1703.08215 | Dietrich Bodeker | Dietrich Bodeker, Guy D. Moore | Electroweak Bubble Wall Speed Limit | 14 pages, 1 figure; version to appear in JCAP | null | 10.1088/1475-7516/2017/05/025 | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In extensions of the Standard Model with extra scalars, the electroweak phase
transition can be very strong, and the bubble walls can be highly relativistic.
We revisit our previous argument that electroweak bubble walls can "run away,"
that is, achieve extreme ultrarelativistic velocities $\gamma \sim 10^{14}$. We
show that, when particles cross the bubble wall, they can emit transition
radiation. Wall-frame soft processes, though suppressed by a power of the
coupling $\alpha$, have a significance enhanced by the $\gamma$-factor of the
wall, limiting wall velocities to $\gamma \sim 1/\alpha$. Though the bubble
walls can move at almost the speed of light, they carry an infinitesimal share
of the plasma's energy.
| [
{
"created": "Thu, 23 Mar 2017 19:51:47 GMT",
"version": "v1"
},
{
"created": "Fri, 12 May 2017 18:56:59 GMT",
"version": "v2"
}
] | 2017-05-24 | [
[
"Bodeker",
"Dietrich",
""
],
[
"Moore",
"Guy D.",
""
]
] | In extensions of the Standard Model with extra scalars, the electroweak phase transition can be very strong, and the bubble walls can be highly relativistic. We revisit our previous argument that electroweak bubble walls can "run away," that is, achieve extreme ultrarelativistic velocities $\gamma \sim 10^{14}$. We show that, when particles cross the bubble wall, they can emit transition radiation. Wall-frame soft processes, though suppressed by a power of the coupling $\alpha$, have a significance enhanced by the $\gamma$-factor of the wall, limiting wall velocities to $\gamma \sim 1/\alpha$. Though the bubble walls can move at almost the speed of light, they carry an infinitesimal share of the plasma's energy. |
hep-ph/9811452 | Iiro Vilja | I. Vilja | Non-Equilibrium Universe and Black Hole Evaporation | 9 pages, 4 figures | Phys.Lett. B465 (1999) 86-94 | 10.1016/S0370-2693(99)01028-X | TURKU-FL/P32-98 | hep-ph astro-ph | null | The evaporation of the black holes during the very early universe is studied.
Starting from black hole filled universe, the distiributions of particle
species are calculated and showed, that they differ remarkably from the
corresponding equilibrium distributions. This may have great impact to the
physics of the very early universe. Also the evolution of the universe during
the evaporation has been studied.
| [
{
"created": "Tue, 24 Nov 1998 09:44:24 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Vilja",
"I.",
""
]
] | The evaporation of the black holes during the very early universe is studied. Starting from black hole filled universe, the distiributions of particle species are calculated and showed, that they differ remarkably from the corresponding equilibrium distributions. This may have great impact to the physics of the very early universe. Also the evolution of the universe during the evaporation has been studied. |
0705.2925 | Schoeffel Laurent | Laurent Schoeffel | Deeply Virtual Compton Scattering at HERA II | 4 pages, 3 figures, prepared for the International Workshop on
Deep-Inelastic Scattering and Related Subjets April 16-20, 2007, Munich,
Germany | null | null | null | hep-ph | null | A new measurement is presented of elastic deeply virtual Compton scattering
(DVCS) based on data taken by the H1 detector during the complete HERA II
period. The data are well described by QCD based calculations. For the first
time, a beam charge asymmetry is obtained in a colliding mode, using data
recorded in $e^-p$ and $e^+p$. A significant non zero value is measured,
related to the interference of QCD and QED processes, namely the DVCS and
Bethe-Heitler reactions.
| [
{
"created": "Mon, 21 May 2007 07:22:41 GMT",
"version": "v1"
},
{
"created": "Tue, 22 May 2007 08:46:05 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Schoeffel",
"Laurent",
""
]
] | A new measurement is presented of elastic deeply virtual Compton scattering (DVCS) based on data taken by the H1 detector during the complete HERA II period. The data are well described by QCD based calculations. For the first time, a beam charge asymmetry is obtained in a colliding mode, using data recorded in $e^-p$ and $e^+p$. A significant non zero value is measured, related to the interference of QCD and QED processes, namely the DVCS and Bethe-Heitler reactions. |
1109.0127 | Wolfgang Schweiger | R. Kleinhappel, W. Schweiger | Hadron Resonances Within a Constituent-Quark Model | 2 pages, 1 figure, poster presented by R. Kleinhappel at "Hadron
2011", Munich, June 13-17, 2011 | null | null | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In order to get a more realistic description of the hadron spectrum we extend
a constituent-quark model by explicit mesonic degrees of freedom. The resulting
system of constituent (anti)quarks, which are subject to an instantaneous
confining force, and mesons, which couple directly to the quarks, is treated by
means of a relativistic coupled-channel framework. It can be formally shown
that the mass-eigenvalue problem for such a system is equivalent to a hadronic
eigenvalue problem in which the eigenstates of the pure confinement potential
(bare hadrons) are coupled via meson loops. Following this kind of approach we
have calculated hadron masses and decay widths for a simple toy model.
| [
{
"created": "Thu, 1 Sep 2011 08:46:59 GMT",
"version": "v1"
}
] | 2011-09-02 | [
[
"Kleinhappel",
"R.",
""
],
[
"Schweiger",
"W.",
""
]
] | In order to get a more realistic description of the hadron spectrum we extend a constituent-quark model by explicit mesonic degrees of freedom. The resulting system of constituent (anti)quarks, which are subject to an instantaneous confining force, and mesons, which couple directly to the quarks, is treated by means of a relativistic coupled-channel framework. It can be formally shown that the mass-eigenvalue problem for such a system is equivalent to a hadronic eigenvalue problem in which the eigenstates of the pure confinement potential (bare hadrons) are coupled via meson loops. Following this kind of approach we have calculated hadron masses and decay widths for a simple toy model. |
2307.01382 | Elmer Ramirez Barreto | Elmer Ramirez Barreto, Alex G. Dias | Fractionary Charged Particles Confronting Lepton Flavor Violation and
the Muon's Anomalous Magnetic Moment | 17 pages, 6 figures | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In light of the recent result published by the Fermilab Muon $(g-2)$
experiment, we investigate a simple model that includes particles of fractional
electric charges: a colour-singlet fermion and a scalar with charges $2/3e$ and
$1/3e$, respectively. The impact of these particles on the anomalous muon's
magnetic moment is examined, particularly the restrictions on their Yukawa
couplings with the light leptons. Given that lepton flavor violation processes
impose stringent constraints on certain scenarios beyond the Standard Model, we
asses the one-loop contribution of the new particles to $(g-2)$ in order to
identify regions in the parameter space consistent with the Fermilab results
and compatible with the current and projected limits on the branching ratio
$Br(\mu \rightarrow e \gamma)$. Taking into account the current lower bound for
the masses of fractionary charged particles, which is around 634 GeV, we show
that the mass of the scalar particle with fractional charge must exceed 1 TeV.
In particular, we present some estimatives for double production of the
colour-singlet fermion at the 14 TeV LHC. Finally, we also study the validity
of our model in light of the QCD lattice results on the muon $(g-2)$.
| [
{
"created": "Mon, 3 Jul 2023 22:27:07 GMT",
"version": "v1"
},
{
"created": "Thu, 1 Feb 2024 15:19:05 GMT",
"version": "v2"
}
] | 2024-02-02 | [
[
"Barreto",
"Elmer Ramirez",
""
],
[
"Dias",
"Alex G.",
""
]
] | In light of the recent result published by the Fermilab Muon $(g-2)$ experiment, we investigate a simple model that includes particles of fractional electric charges: a colour-singlet fermion and a scalar with charges $2/3e$ and $1/3e$, respectively. The impact of these particles on the anomalous muon's magnetic moment is examined, particularly the restrictions on their Yukawa couplings with the light leptons. Given that lepton flavor violation processes impose stringent constraints on certain scenarios beyond the Standard Model, we asses the one-loop contribution of the new particles to $(g-2)$ in order to identify regions in the parameter space consistent with the Fermilab results and compatible with the current and projected limits on the branching ratio $Br(\mu \rightarrow e \gamma)$. Taking into account the current lower bound for the masses of fractionary charged particles, which is around 634 GeV, we show that the mass of the scalar particle with fractional charge must exceed 1 TeV. In particular, we present some estimatives for double production of the colour-singlet fermion at the 14 TeV LHC. Finally, we also study the validity of our model in light of the QCD lattice results on the muon $(g-2)$. |
1409.7182 | Florian Staub | Florian Staub | Beyond-MSSM Higgs sectors | Invited talk given at Prospects for Charged Higgs Discovery at
Colliders - CHARGED 2014, 16-18 September 2014, Uppsala. 9+6 pages; 4
Figures; v2: updated/extended references | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This is a compact overview of Higgs sectors in extensions of the MSSM. The
focus is on the summary of the main features of models with additional singlets
and triplets as well as of models with Dirac gauginos. In addition, also
important aspects of models with an extended gauge sector are shown. Finally, I
comment on available tools which can be used for an adequate study of
non-minimal SUSY models.
| [
{
"created": "Thu, 25 Sep 2014 08:40:47 GMT",
"version": "v1"
},
{
"created": "Tue, 28 Oct 2014 10:10:22 GMT",
"version": "v2"
}
] | 2014-10-29 | [
[
"Staub",
"Florian",
""
]
] | This is a compact overview of Higgs sectors in extensions of the MSSM. The focus is on the summary of the main features of models with additional singlets and triplets as well as of models with Dirac gauginos. In addition, also important aspects of models with an extended gauge sector are shown. Finally, I comment on available tools which can be used for an adequate study of non-minimal SUSY models. |
1307.5015 | Michael Seymour | Michael H. Seymour and Andrzej Siodmok (University of Manchester) | Constraining MPI models using sigma_effective and recent Tevatron and
LHC Underlying Event data | null | null | 10.1007/JHEP10(2013)113 | MAN/HEP/2013/14, MCnet-13-08 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We review the modelling of multiple interactions in the event generator
Herwig++ and study implications of recent tuning efforts to Tevatron and LHC
data. It is often said that measurements of the effective cross section for
double-parton scattering, sigma_effective, are in contradiction with models of
the final state of multi-parton interactions, but we show that the Herwig++
model is consistent with both and gives stable predictions for underlying event
observables at 14 TeV.
| [
{
"created": "Thu, 18 Jul 2013 17:15:47 GMT",
"version": "v1"
},
{
"created": "Tue, 17 Sep 2013 14:37:49 GMT",
"version": "v2"
}
] | 2015-06-16 | [
[
"Seymour",
"Michael H.",
"",
"University of Manchester"
],
[
"Siodmok",
"Andrzej",
"",
"University of Manchester"
]
] | We review the modelling of multiple interactions in the event generator Herwig++ and study implications of recent tuning efforts to Tevatron and LHC data. It is often said that measurements of the effective cross section for double-parton scattering, sigma_effective, are in contradiction with models of the final state of multi-parton interactions, but we show that the Herwig++ model is consistent with both and gives stable predictions for underlying event observables at 14 TeV. |
2110.03984 | Takuya Mizoguchi | Takuya Mizoguchi, Seiji Matsumoto, Minoru Biyajima | Analysis of OPAL Bose-Einstein Correlation at $Z^0$-pole by the second
conventional formula | null | null | 10.1142/S0217751X22501482 | null | hep-ph hep-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We can obtain a second conventional formula (${\rm CF_{II}}$) with two
components by extending the conventional formula ${\rm CF_{I}}$ with one
component for Bose-Einstein Correlation (BEC). We used ${\rm CF_{II}}$ to
analyze the BEC at $Z^0$-pole as part of the OPAL collaboration. $R_1({\rm
G})=0.91\pm 0.03$ fm ($\lambda_1=0.61\pm 0.03$) and $R_2({\rm G})=2.57\pm 0.44$
fm ($\lambda_1=0.35\pm 0.09$) are the estimated interaction region, where
$\lambda_1$ and $\lambda_2$ are the degrees of coherence, and G is the Gaussian
distribution, respectively. Long range correlation (LRC) is also studied.
| [
{
"created": "Fri, 8 Oct 2021 09:03:31 GMT",
"version": "v1"
},
{
"created": "Fri, 8 Jul 2022 15:09:41 GMT",
"version": "v2"
}
] | 2022-11-23 | [
[
"Mizoguchi",
"Takuya",
""
],
[
"Matsumoto",
"Seiji",
""
],
[
"Biyajima",
"Minoru",
""
]
] | We can obtain a second conventional formula (${\rm CF_{II}}$) with two components by extending the conventional formula ${\rm CF_{I}}$ with one component for Bose-Einstein Correlation (BEC). We used ${\rm CF_{II}}$ to analyze the BEC at $Z^0$-pole as part of the OPAL collaboration. $R_1({\rm G})=0.91\pm 0.03$ fm ($\lambda_1=0.61\pm 0.03$) and $R_2({\rm G})=2.57\pm 0.44$ fm ($\lambda_1=0.35\pm 0.09$) are the estimated interaction region, where $\lambda_1$ and $\lambda_2$ are the degrees of coherence, and G is the Gaussian distribution, respectively. Long range correlation (LRC) is also studied. |
hep-ph/9501307 | null | R. K. Ellis, F. Hautmann and B. R. Webber | QCD Scaling Violation at Small x | 8 pages, Latex, 3 uuencoded figures | Phys.Lett.B348:582-588,1995 | 10.1016/0370-2693(95)00148-E | Cavendish-HEP-94/18, Fermilab-PUB-95/006-T | hep-ph | null | We investigate the evolution of parton densities at small values of the
momentum fraction, x, by including resummed anomalous dimensions in the
renormalization group equations. The resummation takes into account the
leading-logarithmic contributions (\alpha_S \ln x)^k given by the BFKL equation
and the next-to-leading-logarithmic corrections from quark evolution. We
present numerical results for the parton densities and the deep inelastic
structure function F_2.
| [
{
"created": "Mon, 16 Jan 1995 14:39:08 GMT",
"version": "v1"
}
] | 2016-09-01 | [
[
"Ellis",
"R. K.",
""
],
[
"Hautmann",
"F.",
""
],
[
"Webber",
"B. R.",
""
]
] | We investigate the evolution of parton densities at small values of the momentum fraction, x, by including resummed anomalous dimensions in the renormalization group equations. The resummation takes into account the leading-logarithmic contributions (\alpha_S \ln x)^k given by the BFKL equation and the next-to-leading-logarithmic corrections from quark evolution. We present numerical results for the parton densities and the deep inelastic structure function F_2. |
1512.07531 | Stephen King | Stephen F. King | Littlest Seesaw | 35 pages, 2 figures, published in JHEP | JHEP 1602 (2016) 085 | 10.1007/JHEP02(2016)085 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose the Littlest Seesaw (LS) model consisting of just two right-handed
neutrinos, where one of them, dominantly responsible for the atmospheric
neutrino mass, has couplings to $(\nu_e,\nu_{\mu},\nu_{\tau})$ proportional to
$(0,1,1)$, while the subdominant right-handed neutrino, mainly responsible for
the solar neutrino mass, has couplings to $(\nu_e,\nu_{\mu},\nu_{\tau})$
proportional to $(1,n,n-2)$. This constrained sequential dominance (CSD) model
preserves the first column of the tri-bimaximal (TB) mixing matrix (TM1) and
has a reactor angle $\theta_{13} \sim (n-1) \frac{\sqrt{2}}{3}
\frac{m_2}{m_3}$. This is a generalisation of CSD ($n=1$) which led to TB
mixing and arises almost as easily if $n\geq 1$ is a real number. We derive
exact analytic formulas for the neutrino masses, lepton mixing angles and CP
phases in terms of the four input parameters and discuss exact sum rules. We
show how CSD ($n=3$) may arise from vacuum alignment due to residual symmetries
of $S_4$. We propose a benchmark model based on $S_4\times Z_3\times Z'_3$,
which fixes $n=3$ and the leptogenesis phase $\eta = 2\pi/3$, leaving only two
inputs $m_a$ and $m_b=m_{ee}$ describing $\Delta m^2_{31}$, $\Delta m^2_{21}$
and $U_{PMNS}$. The LS model predicts a normal mass hierarchy with a massless
neutrino $m_1=0$ and TM1 atmospheric sum rules. The benchmark LS model
additionally predicts: solar angle $\theta_{12}=34^\circ$, reactor angle
$\theta_{13}=8.7^\circ$, atmospheric angle $\theta_{23}=46^\circ$, and Dirac
phase $\delta_{CP}=-87^{\circ}$.
| [
{
"created": "Wed, 23 Dec 2015 16:13:57 GMT",
"version": "v1"
},
{
"created": "Tue, 1 Mar 2016 09:20:16 GMT",
"version": "v2"
}
] | 2016-03-23 | [
[
"King",
"Stephen F.",
""
]
] | We propose the Littlest Seesaw (LS) model consisting of just two right-handed neutrinos, where one of them, dominantly responsible for the atmospheric neutrino mass, has couplings to $(\nu_e,\nu_{\mu},\nu_{\tau})$ proportional to $(0,1,1)$, while the subdominant right-handed neutrino, mainly responsible for the solar neutrino mass, has couplings to $(\nu_e,\nu_{\mu},\nu_{\tau})$ proportional to $(1,n,n-2)$. This constrained sequential dominance (CSD) model preserves the first column of the tri-bimaximal (TB) mixing matrix (TM1) and has a reactor angle $\theta_{13} \sim (n-1) \frac{\sqrt{2}}{3} \frac{m_2}{m_3}$. This is a generalisation of CSD ($n=1$) which led to TB mixing and arises almost as easily if $n\geq 1$ is a real number. We derive exact analytic formulas for the neutrino masses, lepton mixing angles and CP phases in terms of the four input parameters and discuss exact sum rules. We show how CSD ($n=3$) may arise from vacuum alignment due to residual symmetries of $S_4$. We propose a benchmark model based on $S_4\times Z_3\times Z'_3$, which fixes $n=3$ and the leptogenesis phase $\eta = 2\pi/3$, leaving only two inputs $m_a$ and $m_b=m_{ee}$ describing $\Delta m^2_{31}$, $\Delta m^2_{21}$ and $U_{PMNS}$. The LS model predicts a normal mass hierarchy with a massless neutrino $m_1=0$ and TM1 atmospheric sum rules. The benchmark LS model additionally predicts: solar angle $\theta_{12}=34^\circ$, reactor angle $\theta_{13}=8.7^\circ$, atmospheric angle $\theta_{23}=46^\circ$, and Dirac phase $\delta_{CP}=-87^{\circ}$. |
hep-ph/0211295 | Adrian Signer | K. L. Adamson, D. de Florian, A. Signer | Gluon induced contributions to Z gamma production at hadron colliders | 7 pages, 1 figure | Phys.Rev.D67:034016,2003 | 10.1103/PhysRevD.67.034016 | IPPP/02/65 | hep-ph | null | We study the contribution of gluon induced partonic subprocesses to Z gamma
pair production at hadron colliders. These processes contribute only at
next-to-next-to-leading order but are potentially enhanced by two factors of
the gluon parton densities. However, we find that their contribution is modest
and that next-to-leading order calculations give reliable predictions.
| [
{
"created": "Tue, 19 Nov 2002 09:41:15 GMT",
"version": "v1"
}
] | 2011-03-23 | [
[
"Adamson",
"K. L.",
""
],
[
"de Florian",
"D.",
""
],
[
"Signer",
"A.",
""
]
] | We study the contribution of gluon induced partonic subprocesses to Z gamma pair production at hadron colliders. These processes contribute only at next-to-next-to-leading order but are potentially enhanced by two factors of the gluon parton densities. However, we find that their contribution is modest and that next-to-leading order calculations give reliable predictions. |
hep-ph/0004215 | J. William GARY | I.M. Dremin and J.W. Gary | Hadron Multiplicities | 140 pages, 33 figures, version for Physics Reports | Phys.Rept. 349 (2001) 301-393 | 10.1016/S0370-1573(00)00117-4 | FIAN TD31/00 and UCRHEP-E273 | hep-ph | null | We review results on hadron multiplicities in high energy particle
collisions. Both theory and experiment are discussed. The general procedures
used to describe particle multiplicity in Quantum Chromodynamics (QCD) are
summarized. The QCD equations for the generating functions of the multiplicity
distributions are presented both for fixed and running coupling strengths. The
mean multiplicities of gluon and quark jets, their ratio, higher moments, and
the slopes of multiplicities as a function of energy scale, are among the main
global features of multiplicity for which QCD results exist. Recent data from
high energy e+e- experiments, including results for separated quark and gluon
jets, allow rather direct tests of these results. The theoretical predictions
are generally quite successful when confronted with data. Jet and subjet
multiplicities are described. Multiplicity in limited regions of phase space is
discussed in the context of intermittency and fractality. The problem of
singularities in the generating functions is formulated. Some special features
of average multiplicities in heavy quark jets are described.
| [
{
"created": "Mon, 24 Apr 2000 16:10:10 GMT",
"version": "v1"
},
{
"created": "Tue, 19 Sep 2000 14:12:58 GMT",
"version": "v2"
}
] | 2009-10-31 | [
[
"Dremin",
"I. M.",
""
],
[
"Gary",
"J. W.",
""
]
] | We review results on hadron multiplicities in high energy particle collisions. Both theory and experiment are discussed. The general procedures used to describe particle multiplicity in Quantum Chromodynamics (QCD) are summarized. The QCD equations for the generating functions of the multiplicity distributions are presented both for fixed and running coupling strengths. The mean multiplicities of gluon and quark jets, their ratio, higher moments, and the slopes of multiplicities as a function of energy scale, are among the main global features of multiplicity for which QCD results exist. Recent data from high energy e+e- experiments, including results for separated quark and gluon jets, allow rather direct tests of these results. The theoretical predictions are generally quite successful when confronted with data. Jet and subjet multiplicities are described. Multiplicity in limited regions of phase space is discussed in the context of intermittency and fractality. The problem of singularities in the generating functions is formulated. Some special features of average multiplicities in heavy quark jets are described. |
0802.2955 | Vladimir Sauli | V. Sauli | Solving the Bethe-Salpeter equation for a pseudoscalar meson in
Minkowski space | null | J.Phys.G35:035005,2008 | 10.1088/0954-3899/35/3/035005 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A new method of solution of the Bethe-Salpeter equation for a pseudoscalar
quark-antiquark bound state is proposed. With the help of an integral
representation, the results are directly obtained in Minkowski space. Dressing
of Green's functions is naturally taken into account, thus providing the
possible inclusion of a running coupling constant as well as quark propagators.
First numerical results are presented for a simplified ladder approximation.
| [
{
"created": "Wed, 20 Feb 2008 22:27:59 GMT",
"version": "v1"
}
] | 2014-11-18 | [
[
"Sauli",
"V.",
""
]
] | A new method of solution of the Bethe-Salpeter equation for a pseudoscalar quark-antiquark bound state is proposed. With the help of an integral representation, the results are directly obtained in Minkowski space. Dressing of Green's functions is naturally taken into account, thus providing the possible inclusion of a running coupling constant as well as quark propagators. First numerical results are presented for a simplified ladder approximation. |
2008.10513 | Francesco Giovanni Celiberto | Francesco Giovanni Celiberto, Dmitry Yu. Ivanov, Alessandro Papa | Diffractive production of $\Lambda$ hyperons in the high-energy limit of
strong interactions | 23 pages, 6 figures; updated references; slight changes in Eq. (14),
updated Section 2.3, added 2 plots (Figs. 6 and 8), version published in
Phys. Rev. D | null | 10.1103/PhysRevD.102.094019 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose the study of the inclusive production of two $\Lambda$ hyperons or
a single $\Lambda$-particle in association with a jet, featuring high
transverse momenta and large separation in rapidity, as a probe channel of the
resummation of energy logarithms in the QCD perturbative series. We give
predictions, shaped on kinematic ranges typical of CMS and of the backward
CASTOR detector, for cross section and azimuthal-correlation moments between
the two emitted objects, showing how considering the tag of $\Lambda$ baryons
eases the comparison between theoretical results and experimental data in the
phenomenological context of semi-hard reactions.
| [
{
"created": "Mon, 24 Aug 2020 15:27:12 GMT",
"version": "v1"
},
{
"created": "Tue, 25 Aug 2020 08:15:20 GMT",
"version": "v2"
},
{
"created": "Mon, 31 Aug 2020 14:48:20 GMT",
"version": "v3"
},
{
"created": "Sun, 29 Nov 2020 22:19:40 GMT",
"version": "v4"
}
] | 2020-12-30 | [
[
"Celiberto",
"Francesco Giovanni",
""
],
[
"Ivanov",
"Dmitry Yu.",
""
],
[
"Papa",
"Alessandro",
""
]
] | We propose the study of the inclusive production of two $\Lambda$ hyperons or a single $\Lambda$-particle in association with a jet, featuring high transverse momenta and large separation in rapidity, as a probe channel of the resummation of energy logarithms in the QCD perturbative series. We give predictions, shaped on kinematic ranges typical of CMS and of the backward CASTOR detector, for cross section and azimuthal-correlation moments between the two emitted objects, showing how considering the tag of $\Lambda$ baryons eases the comparison between theoretical results and experimental data in the phenomenological context of semi-hard reactions. |
2309.01162 | Kento Asai | Kento Asai, Tomoya Asano, Joe Sato, Masaki J. S. Yang | Contribution of Majoron to Hubble tension in gauged
U(1)$_{L_\mu-L_\tau}$ Model | 24 pages, 4 figures | null | null | STUPP-23-263 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper, we analyze parameter regions that can alleviate the Hubble
tension in the U(1)$_{L_\mu - L_\tau}$ model with the broken lepton number
U(1)$_L$ symmetry. As new particles, this model has a U(1)$_{L_\mu - L_\tau}$
gauge boson $Z'$ and a Majoron $\phi$, which can affect the early universe and
the effective number of neutrino species $N_{\rm eff}$. If $Z'$ and $\phi$
simultaneously exist in the early universe, $Z'\,$-$\,\phi$ interaction
processes such as $Z'\nu_\alpha \leftrightarrow \phi\bar{\nu}_\beta$ occur. The
comparison of $N_{\rm eff}$ between the cases with and without the
$Z'\,$-$\,\phi$ interaction processes shows that these processes make a small
contribution of $\mathcal{O}(10^{-4})$ to $N_{\rm eff}$, and it does not need
to be considered for the alleviation of the Hubble tension. Based on these
facts, we calculated $N_{\rm eff}$ for various Majoron parameters without the
$Z'\,$-$\,\phi$ interaction processes to search parameters that could alleviate
the Hubble tension. As a result, we found that the U(1)$_{L_\mu - L_\tau}$
gauge boson and Majoron can alleviate the Hubble tension in some parameter
regions, and there is a non-trivial synergy contribution between $Z'$ and
$\phi$. Moreover, the parameter region with a lighter mass $m_\phi \lesssim 2$
MeV and a larger coupling $\lambda \gtrsim 10^{-8}$ is excluded because it
predicts too large $N_{\rm eff}$, i.e. $N_{\rm eff} \gtrsim 3.5$. The favored
and restricted regions of the Majoron parameters depend on the $Z'$ parameters
because of the presence of the $Z'$ contribution and synergy one.
| [
{
"created": "Sun, 3 Sep 2023 12:46:02 GMT",
"version": "v1"
}
] | 2023-09-06 | [
[
"Asai",
"Kento",
""
],
[
"Asano",
"Tomoya",
""
],
[
"Sato",
"Joe",
""
],
[
"Yang",
"Masaki J. S.",
""
]
] | In this paper, we analyze parameter regions that can alleviate the Hubble tension in the U(1)$_{L_\mu - L_\tau}$ model with the broken lepton number U(1)$_L$ symmetry. As new particles, this model has a U(1)$_{L_\mu - L_\tau}$ gauge boson $Z'$ and a Majoron $\phi$, which can affect the early universe and the effective number of neutrino species $N_{\rm eff}$. If $Z'$ and $\phi$ simultaneously exist in the early universe, $Z'\,$-$\,\phi$ interaction processes such as $Z'\nu_\alpha \leftrightarrow \phi\bar{\nu}_\beta$ occur. The comparison of $N_{\rm eff}$ between the cases with and without the $Z'\,$-$\,\phi$ interaction processes shows that these processes make a small contribution of $\mathcal{O}(10^{-4})$ to $N_{\rm eff}$, and it does not need to be considered for the alleviation of the Hubble tension. Based on these facts, we calculated $N_{\rm eff}$ for various Majoron parameters without the $Z'\,$-$\,\phi$ interaction processes to search parameters that could alleviate the Hubble tension. As a result, we found that the U(1)$_{L_\mu - L_\tau}$ gauge boson and Majoron can alleviate the Hubble tension in some parameter regions, and there is a non-trivial synergy contribution between $Z'$ and $\phi$. Moreover, the parameter region with a lighter mass $m_\phi \lesssim 2$ MeV and a larger coupling $\lambda \gtrsim 10^{-8}$ is excluded because it predicts too large $N_{\rm eff}$, i.e. $N_{\rm eff} \gtrsim 3.5$. The favored and restricted regions of the Majoron parameters depend on the $Z'$ parameters because of the presence of the $Z'$ contribution and synergy one. |
1911.08507 | Sevgi Karada\u{g} | Sevgi Karada\u{g} and Mehmet Cem G\"u\c{c}l\"u | Multiple scattering production of lepton-pairs in ultraperipheral
heavy-ion collisions | 8 pages, 12 figures | Phys. Rev. C 102, 014904 (2020) | 10.1103/PhysRevC.102.014904 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Ultra-relativistic peripheral collisions of heavy ions at LHC can produce
copies of numbers of lepton pairs via the two-photon process. Since the energy
of the heavy ions is so high, multi-pair production cross-sections of the light
leptons especially electrons are quite large so that it is possible to measure
them experimentally. To calculate the multi-pair production probabilities,
first, we should have an impact parameter dependence cross-section. We have
obtained a well-behaved impact parameter dependence cross-section and by using
the Monte-Carlo methods, we have calculated multi-pair production
cross-sections of electrons and muons in Pb-Pb heavy-ion collisions at LHC
energies. We have also used some experimental restrictions in our calculation
to compare our findings with the experimental results.
| [
{
"created": "Tue, 19 Nov 2019 19:08:20 GMT",
"version": "v1"
},
{
"created": "Thu, 12 Mar 2020 10:13:21 GMT",
"version": "v2"
}
] | 2020-07-15 | [
[
"Karadağ",
"Sevgi",
""
],
[
"Güçlü",
"Mehmet Cem",
""
]
] | Ultra-relativistic peripheral collisions of heavy ions at LHC can produce copies of numbers of lepton pairs via the two-photon process. Since the energy of the heavy ions is so high, multi-pair production cross-sections of the light leptons especially electrons are quite large so that it is possible to measure them experimentally. To calculate the multi-pair production probabilities, first, we should have an impact parameter dependence cross-section. We have obtained a well-behaved impact parameter dependence cross-section and by using the Monte-Carlo methods, we have calculated multi-pair production cross-sections of electrons and muons in Pb-Pb heavy-ion collisions at LHC energies. We have also used some experimental restrictions in our calculation to compare our findings with the experimental results. |
2404.05294 | Shijun Mao | Shijun Mao | Reduction of (pseudo-)Critical Temperatures of Chiral Restoration and
Deconfinement Phase Transitions in a Magnetized PNJL Model | 7 pages, 4 figs, 1 table | null | null | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the chiral restoration and deconfinement phase transitions
under external magnetic field in frame of a Pauli-Villars regularized PNJL
model. A running Polyakov loop scale parameter $T_0(eB)$ is introduced to mimic
the reaction of the gluon sector to the presence of magnetic fields. It is
found that a decreasing $T_0(eB)$ with magnetic fields can realize the inverse
magnetic catalysis phenomena of chiral condensates of $u$ and $d$ quarks,
increase of Polyakov loop and the reduction of (pseudo-)critical temperatures
of chiral restoration and deconfinement phase transitions.
| [
{
"created": "Mon, 8 Apr 2024 08:32:24 GMT",
"version": "v1"
}
] | 2024-04-09 | [
[
"Mao",
"Shijun",
""
]
] | We investigate the chiral restoration and deconfinement phase transitions under external magnetic field in frame of a Pauli-Villars regularized PNJL model. A running Polyakov loop scale parameter $T_0(eB)$ is introduced to mimic the reaction of the gluon sector to the presence of magnetic fields. It is found that a decreasing $T_0(eB)$ with magnetic fields can realize the inverse magnetic catalysis phenomena of chiral condensates of $u$ and $d$ quarks, increase of Polyakov loop and the reduction of (pseudo-)critical temperatures of chiral restoration and deconfinement phase transitions. |
hep-ph/0212190 | Robert Ferdinand Wagenbrunn | R.F. Wagenbrunn (1), S. Boffi (2), L.Ya. Glozman (1), W. Klink (3), W.
Plessas (1), M. Radici (2) ((1) University of Graz, (2) University of Pavia,
(3) University of Iowa) | Nucleon electromagnetic and axial form factors in point-form
relativistic quantum mechanics | 4 pages, 6 figures, contribution to XVIII European Conference on
Few-Body Problems in Physics, September 2002, Bled, Slovenia | Few Body Syst.Suppl. 14 (2003) 411-414 | null | null | hep-ph | null | Results for the proton and neutron electric and magnetic form factors as well
as the nucleon axial form factor are presented for constituent quark models,
based on either one-gluon-exchange and Goldstone-boson-exchange dynamics. The
calculations are performed in a covariant framework using the point-form
approach to relativistic quantum mechanics. The only input to the calculations
is the nucleon wave function of the corresponding constituent quark model. A
comparison is given to results of the instanton-induced constituent quark model
treated with the Bethe-Salpeter equation.
| [
{
"created": "Fri, 13 Dec 2002 13:15:50 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Wagenbrunn",
"R. F.",
""
],
[
"Boffi",
"S.",
""
],
[
"Glozman",
"L. Ya.",
""
],
[
"Klink",
"W.",
""
],
[
"Plessas",
"W.",
""
],
[
"Radici",
"M.",
""
]
] | Results for the proton and neutron electric and magnetic form factors as well as the nucleon axial form factor are presented for constituent quark models, based on either one-gluon-exchange and Goldstone-boson-exchange dynamics. The calculations are performed in a covariant framework using the point-form approach to relativistic quantum mechanics. The only input to the calculations is the nucleon wave function of the corresponding constituent quark model. A comparison is given to results of the instanton-induced constituent quark model treated with the Bethe-Salpeter equation. |
0904.2870 | Bowen Xiao | Jian-Hua Gao and Bo-Wen Xiao | Polarized Deep Inelastic and Elastic Scattering From Gauge/String
Duality | 21 pages, 3 figues.v2:fixed a few typos, ref added. v3: more typos
fixed, context edited, ref updated; v4: comments added, 1 more figure added | Phys.Rev.D80:015025,2009 | 10.1103/PhysRevD.80.015025 | null | hep-ph hep-th nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper, we investigate deep inelastic and elastic scattering on a
polarized spin-1/2 hadron using gauge/string duality. This spin-1/2 hadron
corresponds to a supergravity mode of the dilatino. The polarized deep
inelastic structure functions are computed in supergravity approximation at
large t' Hooft coupling $\lambda$ and finite $x$ with $\lambda^{-1/2}\ll x<1$.
Furthermore, we discuss the moments of all structure functions, and propose an
interesting sum rule $\int_{0}^{1} \textrm{d}x g_2(x, q^2) =0$ for $g_2$
structure function which is known as the Burkhardt-Cottingham sum rule in QCD.
In the end, the elastic scattering is studied and elastic form factors of the
spin-1/2 hadron are calculated within the same framework.
| [
{
"created": "Mon, 20 Apr 2009 02:58:49 GMT",
"version": "v1"
},
{
"created": "Tue, 12 May 2009 18:22:31 GMT",
"version": "v2"
},
{
"created": "Wed, 24 Jun 2009 07:46:20 GMT",
"version": "v3"
},
{
"created": "Fri, 10 Jul 2009 01:28:44 GMT",
"version": "v4"
}
] | 2009-09-02 | [
[
"Gao",
"Jian-Hua",
""
],
[
"Xiao",
"Bo-Wen",
""
]
] | In this paper, we investigate deep inelastic and elastic scattering on a polarized spin-1/2 hadron using gauge/string duality. This spin-1/2 hadron corresponds to a supergravity mode of the dilatino. The polarized deep inelastic structure functions are computed in supergravity approximation at large t' Hooft coupling $\lambda$ and finite $x$ with $\lambda^{-1/2}\ll x<1$. Furthermore, we discuss the moments of all structure functions, and propose an interesting sum rule $\int_{0}^{1} \textrm{d}x g_2(x, q^2) =0$ for $g_2$ structure function which is known as the Burkhardt-Cottingham sum rule in QCD. In the end, the elastic scattering is studied and elastic form factors of the spin-1/2 hadron are calculated within the same framework. |
hep-ph/0207010 | Howard E. Haber | John F. Gunion and Howard E. Haber | The CP-conserving two-Higgs-doublet model: the approach to the
decoupling limit | 54 pages, 2 tables, revtex4 format, some new material added
(including elegant forms for the three-Higgs and four-Higgs couplings) and
typographical errors fixed | Phys.Rev.D67:075019,2003 | 10.1103/PhysRevD.67.075019 | SCIPP 02/10 | hep-ph | null | A CP-even neutral Higgs boson with Standard-Model-like couplings may be the
lightest scalar of a two-Higgs-doublet model. We study the decoupling limit of
the most general CP-conserving two-Higgs-doublet model, where the mass of the
lightest Higgs scalar is significantly smaller than the masses of the other
Higgs bosons of the model. In this case, the properties of the lightest Higgs
boson are nearly indistinguishable from those of the Standard Model Higgs
boson. The first non-trivial corrections to Higgs couplings in the approach to
the decoupling limit are also evaluated. The importance of detecting such
deviations in precision Higgs measurements at future colliders is emphasized.
We also clarify the case in which a neutral Higgs boson can possess
Standard-Model-like couplings in a regime where the decoupling limit does not
apply. The two-Higgs-doublet sector of the minimal supersymmetric model
illustrates many of the above features.
| [
{
"created": "Sun, 30 Jun 2002 23:13:40 GMT",
"version": "v1"
},
{
"created": "Thu, 28 Nov 2002 02:59:46 GMT",
"version": "v2"
},
{
"created": "Sun, 1 Dec 2002 10:39:52 GMT",
"version": "v3"
},
{
"created": "Thu, 2 Jan 2003 02:33:01 GMT",
"version": "v4"
},
{
"cre... | 2014-11-17 | [
[
"Gunion",
"John F.",
""
],
[
"Haber",
"Howard E.",
""
]
] | A CP-even neutral Higgs boson with Standard-Model-like couplings may be the lightest scalar of a two-Higgs-doublet model. We study the decoupling limit of the most general CP-conserving two-Higgs-doublet model, where the mass of the lightest Higgs scalar is significantly smaller than the masses of the other Higgs bosons of the model. In this case, the properties of the lightest Higgs boson are nearly indistinguishable from those of the Standard Model Higgs boson. The first non-trivial corrections to Higgs couplings in the approach to the decoupling limit are also evaluated. The importance of detecting such deviations in precision Higgs measurements at future colliders is emphasized. We also clarify the case in which a neutral Higgs boson can possess Standard-Model-like couplings in a regime where the decoupling limit does not apply. The two-Higgs-doublet sector of the minimal supersymmetric model illustrates many of the above features. |
2207.10704 | Nahuel Barrios | Nahuel Barrios, Marcela Pel\'aez and Urko Reinosa | Two-loop three-gluon vertex from the Curci-Ferrari model and its leading
infrared behavior to all loop orders | 25 pages, 11 figures | null | 10.1103/PhysRevD.106.114039 | null | hep-ph hep-lat hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We evaluate the three-gluon vertex with one vanishing external momentum
within the Curci-Ferrari (CF) model at two-loop order and compare our results
to Landau-gauge lattice simulations of the same vertex function for the SU(2)
and SU(3) gauge groups in four dimensions. The parameters of the model being
adjusted by fitting the two-point functions to lattice data, our evaluation of
the three-gluon vertex arises as a pure prediction. We find that two-loop
corrections systematically improve the agreement between the model and the
lattice data as compared to earlier one-loop calculations, with a better
agreement in the SU(3) case, as already seen in previous studies [1,2]. We also
analyze the renormalization scheme dependence of our calculation. In all cases,
this dependence diminishes when two-loop corrections are included, which is
consistent with the perturbative CF paradigm. In addition, we study the low
momentum regime of the three-gluon vertex in relation with the possibility of
zero-crossing. Within the CF model, we show that the leading infrared behavior
of the exact vertex is given by the same linear logarithm that arises at
one-loop order, multiplied by the all orders cubic ghost dressing function at
zero-momentum (we provide similar exact results for other vertex functions). We
argue that this property remains true within the FP framework under the
assumption that the resummed gluon propagator features a decoupling behavior.
This shows that the zero-crossing is a property of the exact three-gluon vertex
function. Within the CF model, we find however that the scale of the
zero-crossing is considerably reduced when going from one- to two-loop order.
This seems consistent with some recent lattice simulations [3]. Our analysis
also allows us to support recent claims about the dominance of the tree-level
tensor component [4].
| [
{
"created": "Thu, 21 Jul 2022 18:39:01 GMT",
"version": "v1"
},
{
"created": "Wed, 10 Aug 2022 13:16:27 GMT",
"version": "v2"
}
] | 2023-01-10 | [
[
"Barrios",
"Nahuel",
""
],
[
"Peláez",
"Marcela",
""
],
[
"Reinosa",
"Urko",
""
]
] | We evaluate the three-gluon vertex with one vanishing external momentum within the Curci-Ferrari (CF) model at two-loop order and compare our results to Landau-gauge lattice simulations of the same vertex function for the SU(2) and SU(3) gauge groups in four dimensions. The parameters of the model being adjusted by fitting the two-point functions to lattice data, our evaluation of the three-gluon vertex arises as a pure prediction. We find that two-loop corrections systematically improve the agreement between the model and the lattice data as compared to earlier one-loop calculations, with a better agreement in the SU(3) case, as already seen in previous studies [1,2]. We also analyze the renormalization scheme dependence of our calculation. In all cases, this dependence diminishes when two-loop corrections are included, which is consistent with the perturbative CF paradigm. In addition, we study the low momentum regime of the three-gluon vertex in relation with the possibility of zero-crossing. Within the CF model, we show that the leading infrared behavior of the exact vertex is given by the same linear logarithm that arises at one-loop order, multiplied by the all orders cubic ghost dressing function at zero-momentum (we provide similar exact results for other vertex functions). We argue that this property remains true within the FP framework under the assumption that the resummed gluon propagator features a decoupling behavior. This shows that the zero-crossing is a property of the exact three-gluon vertex function. Within the CF model, we find however that the scale of the zero-crossing is considerably reduced when going from one- to two-loop order. This seems consistent with some recent lattice simulations [3]. Our analysis also allows us to support recent claims about the dominance of the tree-level tensor component [4]. |
1304.2533 | Vsevolod Orlovsky | M. A. Andreichikov, B. O. Kerbikov, V. D. Orlovsky and Yu. A. Simonov | Meson Spectrum in Strong Magnetic Fields | 9 pages, 2 figures. arXiv admin note: substantial text overlap with
arXiv:1210.0227 | Phys.Rev. D87 (2013) 094029 | 10.1103/PhysRevD.87.094029 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the relativistic quark-antiquark system embedded in magnetic field.
The Hamiltonian containing confinement, one gluon exchange and spin-spin
interaction is derived. We analytically follow the evolution of the lowest
meson states as a functions of MF strength. Calculating the one gluon exchange
interaction energy <V_OGE> and spin-spin contribution <a_SS> we have observed,
that these corrections remain finite at large magnetic fields, preventing the
vanishing of the total rho-meson mass at some B_crit, as previously thought. We
display the rho masses as functions of magnetic field in comparison with recent
lattice data.
| [
{
"created": "Tue, 9 Apr 2013 11:18:11 GMT",
"version": "v1"
}
] | 2014-01-21 | [
[
"Andreichikov",
"M. A.",
""
],
[
"Kerbikov",
"B. O.",
""
],
[
"Orlovsky",
"V. D.",
""
],
[
"Simonov",
"Yu. A.",
""
]
] | We study the relativistic quark-antiquark system embedded in magnetic field. The Hamiltonian containing confinement, one gluon exchange and spin-spin interaction is derived. We analytically follow the evolution of the lowest meson states as a functions of MF strength. Calculating the one gluon exchange interaction energy <V_OGE> and spin-spin contribution <a_SS> we have observed, that these corrections remain finite at large magnetic fields, preventing the vanishing of the total rho-meson mass at some B_crit, as previously thought. We display the rho masses as functions of magnetic field in comparison with recent lattice data. |
hep-ph/0301249 | Raphael Micha | R. Micha and I. Tkachev | Preheating and Thermalization after Inflation | 10 pages, 3 figures; invited talk at the Workshop on Strong and
Electroweak Matter (SEWM 2002), October 2-5, 2002, Heidelberg, Germany | null | 10.1142/9789812704498_0020 | null | hep-ph | null | After a short review of inlationary preheating, we discuss the development of
equilibrium in the frameworks of massless $\lambda \Phi^4$ model. It is shown
that the process is characterised by the appearance of Kolmogorov spectra and
the evolution towards thermal equilibrium follows self-similar dynamics.
Simplified kinetic theory gives values for all characteristic exponents which
are close to what is observed in lattice simulations. This allows estimation of
the resulting reheating temperature.
| [
{
"created": "Tue, 28 Jan 2003 17:21:59 GMT",
"version": "v1"
}
] | 2017-08-23 | [
[
"Micha",
"R.",
""
],
[
"Tkachev",
"I.",
""
]
] | After a short review of inlationary preheating, we discuss the development of equilibrium in the frameworks of massless $\lambda \Phi^4$ model. It is shown that the process is characterised by the appearance of Kolmogorov spectra and the evolution towards thermal equilibrium follows self-similar dynamics. Simplified kinetic theory gives values for all characteristic exponents which are close to what is observed in lattice simulations. This allows estimation of the resulting reheating temperature. |
2007.08526 | Kevin Kelly | Kevin J. Kelly, Pedro A.N. Machado, Stephen J. Parke, Yuber F.
Perez-Gonzalez, and Renata Zukanovich Funchal | Back to (Mass-)Square(d) One: The Neutrino Mass Ordering in Light of
Recent Data | 5 pages, 3 figures + 1 appendix (1 figure). Updated NOvA analysis,
matches published version | Phys. Rev. D 103, 013004 (2021) | 10.1103/PhysRevD.103.013004 | FERMILAB-PUB-20-330-T | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | We inspect recently updated neutrino oscillation data -- specifically coming
from the Tokai to Kamioka and NuMI Off-axis $\nu_e$ Appearance experiments --
and how they are analyzed to determine whether the neutrino mass ordering is
normal ($m_1 < m_2 < m_3$) or inverted ($m_3 < m_1 < m_2$). We show that,
despite previous results giving a strong preference for the normal ordering,
with the newest data from T2K and NOvA, this preference has all but vanished.
Additionally, we highlight the importance of this result for non-oscillation
probes of neutrinos, including neutrinoless double beta decay and cosmology.
Future experiments, including JUNO, DUNE, and T2HK will provide valuable
information and determine the mass ordering at a high confidence level.
| [
{
"created": "Thu, 16 Jul 2020 18:00:00 GMT",
"version": "v1"
},
{
"created": "Mon, 11 Jan 2021 18:33:12 GMT",
"version": "v2"
}
] | 2021-01-12 | [
[
"Kelly",
"Kevin J.",
""
],
[
"Machado",
"Pedro A. N.",
""
],
[
"Parke",
"Stephen J.",
""
],
[
"Perez-Gonzalez",
"Yuber F.",
""
],
[
"Funchal",
"Renata Zukanovich",
""
]
] | We inspect recently updated neutrino oscillation data -- specifically coming from the Tokai to Kamioka and NuMI Off-axis $\nu_e$ Appearance experiments -- and how they are analyzed to determine whether the neutrino mass ordering is normal ($m_1 < m_2 < m_3$) or inverted ($m_3 < m_1 < m_2$). We show that, despite previous results giving a strong preference for the normal ordering, with the newest data from T2K and NOvA, this preference has all but vanished. Additionally, we highlight the importance of this result for non-oscillation probes of neutrinos, including neutrinoless double beta decay and cosmology. Future experiments, including JUNO, DUNE, and T2HK will provide valuable information and determine the mass ordering at a high confidence level. |
0912.0165 | Massimo Mannarelli | Massimo Mannarelli, Cristina Manuel, Sergi Gonzalez-Solis, Michael
Strickland | Jet energy loss in the quark-gluon plasma by stream instabilities | 10 pages, 3 figures | Phys.Rev.D81:074036,2010 | 10.1103/PhysRevD.81.074036 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the evolution of the plasma instabilities induced by two jets of
particles propagating in opposite directions and crossing a thermally
equilibrated non-Abelian plasma. In order to simplify the analysis we assume
that the two jets of partons can be described with uniform distribution
functions in coordinate space and by Gaussian distribution functions in
momentum space. We find that while crossing the quark-gluon plasma, the jets of
particles excite unstable chromomagnetic and chromoelectric modes. These fields
interact with the particles (or hard modes) of the plasma inducing the
production of currents; thus, the energy lost by the jets is absorbed by both
the gauge fields and the hard modes of the plasma. We compare the outcome of
the numerical simulations with the analytical calculation performed assuming
that the jets of particles can be described by a tsunami-like distribution
function. We find qualitative and semi-quantitative agreement between the
results obtained with the two methods.
| [
{
"created": "Tue, 1 Dec 2009 14:55:12 GMT",
"version": "v1"
}
] | 2014-11-20 | [
[
"Mannarelli",
"Massimo",
""
],
[
"Manuel",
"Cristina",
""
],
[
"Gonzalez-Solis",
"Sergi",
""
],
[
"Strickland",
"Michael",
""
]
] | We study the evolution of the plasma instabilities induced by two jets of particles propagating in opposite directions and crossing a thermally equilibrated non-Abelian plasma. In order to simplify the analysis we assume that the two jets of partons can be described with uniform distribution functions in coordinate space and by Gaussian distribution functions in momentum space. We find that while crossing the quark-gluon plasma, the jets of particles excite unstable chromomagnetic and chromoelectric modes. These fields interact with the particles (or hard modes) of the plasma inducing the production of currents; thus, the energy lost by the jets is absorbed by both the gauge fields and the hard modes of the plasma. We compare the outcome of the numerical simulations with the analytical calculation performed assuming that the jets of particles can be described by a tsunami-like distribution function. We find qualitative and semi-quantitative agreement between the results obtained with the two methods. |
2308.06114 | Abhishek Chikkaballi | Abhishek Chikkaballi, Kamila Kowalska, Enrico Maria Sessolo | Naturally small neutrino mass with asymptotic safety and
gravitational-wave signatures | 39 pages, 5 figures, 2 tables. References added, typos corrected,
matches the published version | JHEP 11 (2023) 224 | 10.1007/JHEP11(2023)224 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We revisit the dynamical generation of an arbitrarily small neutrino Yukawa
coupling in the Standard Model with trans-Planckian asymptotic safety and apply
the same mechanism to the gauged $B-L$ model. We show that thanks to the
presence of additional irrelevant couplings, the described neutrino-mass
generation in the $B-L$ model is potentially more in line with existing
theoretical calculations in quantum gravity. Interestingly, the model can
accommodate, in full naturalness and without extensions, the possibility of
purely Dirac, pseudo-Dirac, and Majorana neutrinos with any see-saw scale. We
investigate eventual distinctive signatures of these cases in the detection of
gravitational waves from first-order phase transitions. We find that, while it
is easy to produce a signal observable in new-generation interferometers, its
discriminating features are washed out by the strong dependence of the
gravitational-wave spectrum on the relevant parameters of the scalar potential.
| [
{
"created": "Fri, 11 Aug 2023 13:04:46 GMT",
"version": "v1"
},
{
"created": "Mon, 27 Nov 2023 13:48:24 GMT",
"version": "v2"
}
] | 2023-12-05 | [
[
"Chikkaballi",
"Abhishek",
""
],
[
"Kowalska",
"Kamila",
""
],
[
"Sessolo",
"Enrico Maria",
""
]
] | We revisit the dynamical generation of an arbitrarily small neutrino Yukawa coupling in the Standard Model with trans-Planckian asymptotic safety and apply the same mechanism to the gauged $B-L$ model. We show that thanks to the presence of additional irrelevant couplings, the described neutrino-mass generation in the $B-L$ model is potentially more in line with existing theoretical calculations in quantum gravity. Interestingly, the model can accommodate, in full naturalness and without extensions, the possibility of purely Dirac, pseudo-Dirac, and Majorana neutrinos with any see-saw scale. We investigate eventual distinctive signatures of these cases in the detection of gravitational waves from first-order phase transitions. We find that, while it is easy to produce a signal observable in new-generation interferometers, its discriminating features are washed out by the strong dependence of the gravitational-wave spectrum on the relevant parameters of the scalar potential. |
2102.05138 | Konstantin Stankevich | Konstantin Stankevich and Alexander Studenikin | Collective neutrino oscillations accounting for neutrino quantum
decoherence | 3 pages in LaTex, based on the presentation at the 40th International
Conference on High Energy Physics (ICHEP 2020), 28 July - 6 August 2020,
Prague, Czech Republic | null | 10.22323/1.390.0216 | null | hep-ph | http://creativecommons.org/publicdomain/zero/1.0/ | In our previous studies (see [1] and references therein) we developed a new
theoretical framework that enabled one to consider a new mechanism of neutrino
quantum decoherence engendered by the neutrino radiative decay. In parallel,
another framework was developed (see [2] and references therein) for the
description of the neutrino quantum decoherence due to the non-forward neutrino
scattering processes. Both mechanisms are described by the master equations in
the Lindblad form.
We study the influence of the neutrino quantum decoherence on collective
neutrino oscillations. In the present studies we are are not interested in a
specific mechanism of neutrino quantum decoherence. Therefore, we use the
general Lindblad master equation for the description of the neutrino quantum
decoherence and do not fix an analytical expressions for the decoherence and
relaxation parameters.
| [
{
"created": "Tue, 9 Feb 2021 21:27:41 GMT",
"version": "v1"
}
] | 2022-09-21 | [
[
"Stankevich",
"Konstantin",
""
],
[
"Studenikin",
"Alexander",
""
]
] | In our previous studies (see [1] and references therein) we developed a new theoretical framework that enabled one to consider a new mechanism of neutrino quantum decoherence engendered by the neutrino radiative decay. In parallel, another framework was developed (see [2] and references therein) for the description of the neutrino quantum decoherence due to the non-forward neutrino scattering processes. Both mechanisms are described by the master equations in the Lindblad form. We study the influence of the neutrino quantum decoherence on collective neutrino oscillations. In the present studies we are are not interested in a specific mechanism of neutrino quantum decoherence. Therefore, we use the general Lindblad master equation for the description of the neutrino quantum decoherence and do not fix an analytical expressions for the decoherence and relaxation parameters. |
2012.09170 | Melissa van Beekveld | Melissa van Beekveld, Wim Beenakker | The role of the threshold variable in soft-gluon resummation of the
$t\bar{t}h$ production process | Code available upon request | null | 10.1007/JHEP05(2021)196 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the role of the threshold variable in soft-gluon threshold
resummation. We focus on the computation of the resummed total cross section,
the final-state invariant-mass distribution, and transverse-momentum
distribution of the Higgs boson when produced in association with a
top-anti-top quark pair for the Large Hadron Collider operating at 13 TeV. We
show that different choices for the threshold variable result in differences at
next-to-leading power, i.e. contributions that are down by one power of the
threshold variable. These contributions are noticeable numerically, although
their effect on the resummed observables lies within the scale uncertainty of
those observables. The average central results, obtained after combining
several central-scale choices, agree remarkably well for different choices of
the threshold variable. However, different threshold choices do effect the
resulting scale uncertainty. To compute our results, we introduce a novel
numerical method that we call the deformation method, which aids the
stabilization of the inverse Mellin transform in cases where the analytical
Mellin transform of the partonic cross section is unknown. We show that this
method leads to a factor of 10 less function evaluations, while gaining a
factor of 4-5 in numerical precision when compared to the standard method.
| [
{
"created": "Wed, 16 Dec 2020 19:00:00 GMT",
"version": "v1"
}
] | 2023-01-11 | [
[
"van Beekveld",
"Melissa",
""
],
[
"Beenakker",
"Wim",
""
]
] | We study the role of the threshold variable in soft-gluon threshold resummation. We focus on the computation of the resummed total cross section, the final-state invariant-mass distribution, and transverse-momentum distribution of the Higgs boson when produced in association with a top-anti-top quark pair for the Large Hadron Collider operating at 13 TeV. We show that different choices for the threshold variable result in differences at next-to-leading power, i.e. contributions that are down by one power of the threshold variable. These contributions are noticeable numerically, although their effect on the resummed observables lies within the scale uncertainty of those observables. The average central results, obtained after combining several central-scale choices, agree remarkably well for different choices of the threshold variable. However, different threshold choices do effect the resulting scale uncertainty. To compute our results, we introduce a novel numerical method that we call the deformation method, which aids the stabilization of the inverse Mellin transform in cases where the analytical Mellin transform of the partonic cross section is unknown. We show that this method leads to a factor of 10 less function evaluations, while gaining a factor of 4-5 in numerical precision when compared to the standard method. |
1905.04498 | Yao Ji | V. M. Braun, Yao Ji, and A. N. Manashov | Two-loop evolution equation for the B-meson distribution amplitude | 6 pages, 1 figure | Phys. Rev. D 100, 014023 (2019) | 10.1103/PhysRevD.100.014023 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We derive the two-loop evolution equation of the B-meson light-cone
distribution amplitude which is the last missing element for the
next-to-next-to-leading logarithmic resummation of QCD corrections to B decays
in QCD factorization. We argue that the evolution kernel to all orders in
perturbation theory can be written as a logarithm of the generator of special
conformal transformations times the cusp anomalous dimension, up to a
scheme-dependent overall constant. Up to this constant term, the evolution
kernel to a given order in perturbation theory can be obtained from the
calculation of special conformal anomaly at one order less.
| [
{
"created": "Sat, 11 May 2019 10:51:12 GMT",
"version": "v1"
}
] | 2019-07-24 | [
[
"Braun",
"V. M.",
""
],
[
"Ji",
"Yao",
""
],
[
"Manashov",
"A. N.",
""
]
] | We derive the two-loop evolution equation of the B-meson light-cone distribution amplitude which is the last missing element for the next-to-next-to-leading logarithmic resummation of QCD corrections to B decays in QCD factorization. We argue that the evolution kernel to all orders in perturbation theory can be written as a logarithm of the generator of special conformal transformations times the cusp anomalous dimension, up to a scheme-dependent overall constant. Up to this constant term, the evolution kernel to a given order in perturbation theory can be obtained from the calculation of special conformal anomaly at one order less. |
1006.4998 | Suyong Choi | Suyong Choi | Construction of a Kinematic Variable Sensitive to the Mass of the
Standard Model Higgs Boson in H->WW*->l l nu nu-bar using Symbolic Regression | 10 pages, 8 figures | JHEP 1108:110,2011 | 10.1007/JHEP08(2011)110 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We derive a kinematic variable that is sensitive to the mass of the Standard
Model Higgs boson (M_H) in the H->WW*->l l nu nu-bar channel using symbolic
regression method. Explicit mass reconstruction is not possible in this channel
due to the presence of two neutrinos which escape detection. Mass determination
problem is that of finding a mass-sensitive function that depends on the
measured observables. We use symbolic regression, which is an analytical
approach to the problem of non-linear regression, to derive an analytic formula
sensitive to M_H from the two lepton momenta and the missing transverse
momentum. Using the newly-derived mass-sensitive variable, we expect Higgs mass
resolutions between 1 to 4 GeV for M_H between 130 and 190 GeV at the LHC with
10 fb^-1 of data. This is the first time symbolic regression method has been
applied to a particle physics problem.
| [
{
"created": "Fri, 25 Jun 2010 13:56:16 GMT",
"version": "v1"
}
] | 2011-08-31 | [
[
"Choi",
"Suyong",
""
]
] | We derive a kinematic variable that is sensitive to the mass of the Standard Model Higgs boson (M_H) in the H->WW*->l l nu nu-bar channel using symbolic regression method. Explicit mass reconstruction is not possible in this channel due to the presence of two neutrinos which escape detection. Mass determination problem is that of finding a mass-sensitive function that depends on the measured observables. We use symbolic regression, which is an analytical approach to the problem of non-linear regression, to derive an analytic formula sensitive to M_H from the two lepton momenta and the missing transverse momentum. Using the newly-derived mass-sensitive variable, we expect Higgs mass resolutions between 1 to 4 GeV for M_H between 130 and 190 GeV at the LHC with 10 fb^-1 of data. This is the first time symbolic regression method has been applied to a particle physics problem. |
hep-ph/0509046 | Xiao-Ming Xu | Xiao-Ming Xu, Peng Ru, H.J. Weber | Triple-quark elastic scatterings and thermalization | 19 pages, 4 figures, 1 table, LaTex, define u12,u13,u21,u23,u31,u32 | Phys.Lett. B629 (2005) 68-76 | 10.1016/j.physletb.2005.09.051 | null | hep-ph | null | Triple-quark elastic scattering amplitudes from perturbative QCD are first
calculated and then used in a transport equation to study the thermalization of
quark matter. By examining momentum isotropy to which the transport equation
leads, we can determine thermalization time and offer an initial thermal quark
distribution function. With an anisotropic initial quark distribution, which is
relevant to quark matter initially created in a central Au-Au collision at
\sqrt {s_{NN}}=200 GeV, the transport equation gives a time of the order of 1.8
fm/c for quark matter itself to thermalize by the triple-quark scatterings.
| [
{
"created": "Tue, 6 Sep 2005 12:25:51 GMT",
"version": "v1"
},
{
"created": "Sun, 2 Oct 2005 13:29:41 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Xu",
"Xiao-Ming",
""
],
[
"Ru",
"Peng",
""
],
[
"Weber",
"H. J.",
""
]
] | Triple-quark elastic scattering amplitudes from perturbative QCD are first calculated and then used in a transport equation to study the thermalization of quark matter. By examining momentum isotropy to which the transport equation leads, we can determine thermalization time and offer an initial thermal quark distribution function. With an anisotropic initial quark distribution, which is relevant to quark matter initially created in a central Au-Au collision at \sqrt {s_{NN}}=200 GeV, the transport equation gives a time of the order of 1.8 fm/c for quark matter itself to thermalize by the triple-quark scatterings. |
0904.3103 | Hooman Davoudiasl | Hooman Davoudiasl | Dark Matter with Time-Varying Leptophilic Couplings | 5 pages, Revtex 4. Estimates of possible gamma ray signals, a note
regarding the recent Fermi-LAT results, and several new references added in
this version | Phys.Rev.D80:043502,2009 | 10.1103/PhysRevD.80.043502 | null | hep-ph astro-ph.HE hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Two general problems arise when interpreting the recent cosmic ray data as
signals of Dark Matter (DM) annihilation: (i) the required cross section is too
large by O(100), and (ii) the annihilation products seem to be mostly leptonic.
We propose to address these two problems by assuming that the couplings of DM
to leptons grow with time. This can be achieved by a dynamic localization of DM
in extra dimensions. A possible outcome of this proposal is a time (red-shift)
dependent annihilation signal, in terms of strength and dominant final states.
| [
{
"created": "Tue, 21 Apr 2009 18:53:40 GMT",
"version": "v1"
},
{
"created": "Thu, 16 Jul 2009 20:39:27 GMT",
"version": "v2"
}
] | 2009-08-18 | [
[
"Davoudiasl",
"Hooman",
""
]
] | Two general problems arise when interpreting the recent cosmic ray data as signals of Dark Matter (DM) annihilation: (i) the required cross section is too large by O(100), and (ii) the annihilation products seem to be mostly leptonic. We propose to address these two problems by assuming that the couplings of DM to leptons grow with time. This can be achieved by a dynamic localization of DM in extra dimensions. A possible outcome of this proposal is a time (red-shift) dependent annihilation signal, in terms of strength and dominant final states. |
0710.3325 | Jun-Qing Xia | Jun-Qing Xia, Hong Li, Xiulian Wang, Xinmin Zhang | Testing CPT Symmetry with CMB Measurements | 4 pages, 2 figures, 1 table, Accepted for publication on A&A | Astron.Astrophys.483:715-718,2008 | 10.1051/0004-6361:200809410 | null | hep-ph astro-ph gr-qc hep-th | null | In this paper we study the possibility of testing \emph{CPT} symmetry with
Cosmic Microwave Background (CMB) measurements. Working with an effective
lagrangian of the photon with \emph{CPT} violation ${\cal L} \sim
p_{\mu}A_{\nu}\tilde F^{\mu\nu}$ which causes the polarization vectors of the
propagating CMB photons rotated, we determine the rotation angle $\Delta\alpha$
using the BOOMERanG 2003 and the WMAP3 angular power spectra. In this analysis
we have included the newly released $TC$ and $GC$ ($l<450$) information of
WMAP3 and found $\Delta\alpha=-6.2\pm3.8$ deg at $1\sigma$ confidence level.
This result increases slightly the significance for the \emph{CPT} violation
obtained in our previous paper (Feng \emph{et al.}, 2006) $\Delta\alpha=-6.0
\pm 4.0$ deg (1$\sigma$). Furthermore we examine the constraint on the rotation
angle with the simulated Planck data. Our results show that the Planck will be
sensitive to $\Delta \alpha$ at the level of 0.057 deg and able to test the
\emph{CPT} symmetry with a higher precision.
| [
{
"created": "Wed, 17 Oct 2007 15:37:07 GMT",
"version": "v1"
},
{
"created": "Wed, 27 Feb 2008 15:36:59 GMT",
"version": "v2"
}
] | 2008-11-07 | [
[
"Xia",
"Jun-Qing",
""
],
[
"Li",
"Hong",
""
],
[
"Wang",
"Xiulian",
""
],
[
"Zhang",
"Xinmin",
""
]
] | In this paper we study the possibility of testing \emph{CPT} symmetry with Cosmic Microwave Background (CMB) measurements. Working with an effective lagrangian of the photon with \emph{CPT} violation ${\cal L} \sim p_{\mu}A_{\nu}\tilde F^{\mu\nu}$ which causes the polarization vectors of the propagating CMB photons rotated, we determine the rotation angle $\Delta\alpha$ using the BOOMERanG 2003 and the WMAP3 angular power spectra. In this analysis we have included the newly released $TC$ and $GC$ ($l<450$) information of WMAP3 and found $\Delta\alpha=-6.2\pm3.8$ deg at $1\sigma$ confidence level. This result increases slightly the significance for the \emph{CPT} violation obtained in our previous paper (Feng \emph{et al.}, 2006) $\Delta\alpha=-6.0 \pm 4.0$ deg (1$\sigma$). Furthermore we examine the constraint on the rotation angle with the simulated Planck data. Our results show that the Planck will be sensitive to $\Delta \alpha$ at the level of 0.057 deg and able to test the \emph{CPT} symmetry with a higher precision. |
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