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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0803.2231
|
Michael Seymour
|
Michael H. Seymour (Manchester/CERN), Christopher Tevlin (Manchester)
|
TeVJet: A general framework for the calculation of jet observables in
NLO QCD
|
52 pages, program available from
http://www.hep.man.ac.uk/u/chris/tevjet
| null | null |
MAN/HEP/2008/3, CERN-PH-TH/2008-044
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In this paper we present the parton level Monte Carlo program TeVJet, a
direct implementation of the dipole subtraction method for calculating jet
cross sections in NLO QCD. It has been written so as to allow the inclusion of
new processes in as straightforward a way as possible. The user must provide
the usual ingredients for an NLO calculation and from these the
process-independent parts required to make the phase space integrals finite in
4 dimensions are automatically generated. These integrals are then performed
using Monte Carlo techniques. We present the results for a few example
processes.
|
[
{
"created": "Fri, 14 Mar 2008 19:56:59 GMT",
"version": "v1"
}
] |
2008-03-17
|
[
[
"Seymour",
"Michael H.",
"",
"Manchester/CERN"
],
[
"Tevlin",
"Christopher",
"",
"Manchester"
]
] |
In this paper we present the parton level Monte Carlo program TeVJet, a direct implementation of the dipole subtraction method for calculating jet cross sections in NLO QCD. It has been written so as to allow the inclusion of new processes in as straightforward a way as possible. The user must provide the usual ingredients for an NLO calculation and from these the process-independent parts required to make the phase space integrals finite in 4 dimensions are automatically generated. These integrals are then performed using Monte Carlo techniques. We present the results for a few example processes.
|
hep-ph/9612242
| null |
R. Delbourgo and D. Liu (University of Tasmania)
|
The gauge technique for heavy quarks
|
12 pages, RevTex format. Typographical errors corrected (factors of 2
in eqs 25 and 26)
|
Phys.Rev.D56:27-31,1997
|
10.1103/PhysRevD.56.27
|
UTAS-PHYS-96-56
|
hep-ph
| null |
It is possible to determine a propapagator for heavy quarks to order 1/m in
any covariant gauge, which applies universally to all quarks, by using the
gauge technique. The leading behaviour is given by a _0F_2 function and the
result is reliable in the infrared limit, accounting for soft-gluon corrections
to the quark in internal loops.
|
[
{
"created": "Wed, 4 Dec 1996 14:46:00 GMT",
"version": "v1"
},
{
"created": "Thu, 5 Dec 1996 22:02:00 GMT",
"version": "v2"
}
] |
2008-11-26
|
[
[
"Delbourgo",
"R.",
"",
"University of Tasmania"
],
[
"Liu",
"D.",
"",
"University of Tasmania"
]
] |
It is possible to determine a propapagator for heavy quarks to order 1/m in any covariant gauge, which applies universally to all quarks, by using the gauge technique. The leading behaviour is given by a _0F_2 function and the result is reliable in the infrared limit, accounting for soft-gluon corrections to the quark in internal loops.
|
0912.1557
|
N. D. Tracas
|
G. K. Leontaris, N.D. Tracas
|
Gauge coupling flux thresholds, exotic matter and the unification scale
in F-SU(5) GUT
|
20 pages, 3 figures, references and extended comments on KK
thresholds effects added
|
Eur.Phys.J.C67:489-498,2010
|
10.1140/epjc/s10052-010-1298-2
| null |
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We explore the gauge coupling relations and the unification scale in F-theory
SU(5) GUT broken down to the Standard Model by an internal U(1)Y gauge flux. We
consider variants with exotic matter representations which may appear in these
constructions and investigate their role in the effective field theory model.
We make a detailed investigation on the conditions imposed on the extraneous
matter to raise the unification scale and make the color triplets heavy in
order to avoid fast proton decay. We also discuss in brief the implications on
the gaugino masses.
|
[
{
"created": "Tue, 8 Dec 2009 18:05:15 GMT",
"version": "v1"
},
{
"created": "Mon, 14 Dec 2009 14:34:18 GMT",
"version": "v2"
},
{
"created": "Sun, 4 Jul 2010 07:14:56 GMT",
"version": "v3"
}
] |
2010-07-06
|
[
[
"Leontaris",
"G. K.",
""
],
[
"Tracas",
"N. D.",
""
]
] |
We explore the gauge coupling relations and the unification scale in F-theory SU(5) GUT broken down to the Standard Model by an internal U(1)Y gauge flux. We consider variants with exotic matter representations which may appear in these constructions and investigate their role in the effective field theory model. We make a detailed investigation on the conditions imposed on the extraneous matter to raise the unification scale and make the color triplets heavy in order to avoid fast proton decay. We also discuss in brief the implications on the gaugino masses.
|
1802.02801
|
Stefan Leupold
|
Shankar Sunil Nair, Elisabetta Perotti, Stefan Leupold (UU)
|
Constraining P and CP violation in the main decay of the neutral Sigma
hyperon
|
13 pages
| null |
10.1016/j.physletb.2018.09.065
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
On general grounds based on quantum field theory the decay amplitude for
$\Sigma^0 \to \Lambda \gamma$ consists of a parity conserving magnetic and a
parity violating electric dipole transition moment. Because of the subsequent
self-analyzing weak decay of the $\Lambda$ hyperon the interference between
magnetic and electric dipole transition moment leads to an asymmetry in the
angular distribution. Comparing the decay distributions for the $\Sigma^0$
hyperon and its antiparticle gives access to possible C and CP violation. Based
on flavor SU(3) symmetry the present upper limit on the neutron electric dipole
moment can be translated to an upper limit for the angular asymmetry. It turns
out to be far below any experimental resolution that one can expect in the
foreseeable future. Thus any true observation of a CP violating angular
asymmetry would constitute physics beyond the standard model, even if extended
by a CP violating QCD theta-vacuum-angle term.
|
[
{
"created": "Thu, 8 Feb 2018 10:52:18 GMT",
"version": "v1"
}
] |
2018-12-05
|
[
[
"Nair",
"Shankar Sunil",
"",
"UU"
],
[
"Perotti",
"Elisabetta",
"",
"UU"
],
[
"Leupold",
"Stefan",
"",
"UU"
]
] |
On general grounds based on quantum field theory the decay amplitude for $\Sigma^0 \to \Lambda \gamma$ consists of a parity conserving magnetic and a parity violating electric dipole transition moment. Because of the subsequent self-analyzing weak decay of the $\Lambda$ hyperon the interference between magnetic and electric dipole transition moment leads to an asymmetry in the angular distribution. Comparing the decay distributions for the $\Sigma^0$ hyperon and its antiparticle gives access to possible C and CP violation. Based on flavor SU(3) symmetry the present upper limit on the neutron electric dipole moment can be translated to an upper limit for the angular asymmetry. It turns out to be far below any experimental resolution that one can expect in the foreseeable future. Thus any true observation of a CP violating angular asymmetry would constitute physics beyond the standard model, even if extended by a CP violating QCD theta-vacuum-angle term.
|
1404.1053
|
Stefano Porto
|
Stefano Porto, Gudrid A. Moortgat-Pick, Krzysztof Rolbiecki
|
Towards discrimination of MSSM and NMSSM scenarios at colliders
|
9 pages, 10 figures. Talk presented at the International Workshop on
Future Linear Colliders (LCWS13), Tokyo, Japan, 11-15 November 2013
| null | null |
DESY 14-042
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
One of the challenging tasks at future experiments is the clear
identification of the underlying new physics model. In this study we
concentrate on the distinction between different supersymmetric models, the
MSSM and the NMSSM, exploring the gaugino/higgsino sector as an alternative to
the Higgs sector. Under the assumption that only the light chargino and
neutralino masses and polarized cross sections $e^+e^-\to
\tilde{\chi}^0_i\tilde{\chi}^0_j$, $\tilde{\chi}^+_i\tilde{\chi}^-_j$ have been
measured, we perform a fit of the fundamental MSSM parameters $M_1$, $M_2$,
$\mu$ and $\tan\beta$ and study whether a model distinction is possible. We
focus here on the challenging cases of scenarios with a relatively heavy
singlino and address two classes of neutralino mixing,
$\tilde{\chi}^0_1\sim$higgsino-like versus $\tilde{\chi}^0_1\sim$gaugino-like.
|
[
{
"created": "Thu, 3 Apr 2014 19:28:15 GMT",
"version": "v1"
}
] |
2014-04-04
|
[
[
"Porto",
"Stefano",
""
],
[
"Moortgat-Pick",
"Gudrid A.",
""
],
[
"Rolbiecki",
"Krzysztof",
""
]
] |
One of the challenging tasks at future experiments is the clear identification of the underlying new physics model. In this study we concentrate on the distinction between different supersymmetric models, the MSSM and the NMSSM, exploring the gaugino/higgsino sector as an alternative to the Higgs sector. Under the assumption that only the light chargino and neutralino masses and polarized cross sections $e^+e^-\to \tilde{\chi}^0_i\tilde{\chi}^0_j$, $\tilde{\chi}^+_i\tilde{\chi}^-_j$ have been measured, we perform a fit of the fundamental MSSM parameters $M_1$, $M_2$, $\mu$ and $\tan\beta$ and study whether a model distinction is possible. We focus here on the challenging cases of scenarios with a relatively heavy singlino and address two classes of neutralino mixing, $\tilde{\chi}^0_1\sim$higgsino-like versus $\tilde{\chi}^0_1\sim$gaugino-like.
|
hep-ph/0510221
|
Markus Diehl
|
M. Diehl
|
Generalized parton distributions from form factors
|
10 pages, 11 figures. To appear in: Procs. of the Workshop on
Light-Cone QCD and Nonperturbative Hadron Physics 2005 (LC 2005), Cairns,
Australia, 2005
| null |
10.1016/j.nuclphysbps.2006.08.048
|
DESY-05-204
|
hep-ph
| null |
The electromagnetic nucleon form factors provide constraints on generalized
quark distributions. Key results of the study presented here are a strong
dependence of the average impact parameter of quarks on their longitudinal
momentum fraction, a striking difference in the t dependence of u and d quark
contributions to elastic form factors, and an estimate of the orbital angular
momentum carried by valence quarks in the nucleon.
|
[
{
"created": "Mon, 17 Oct 2005 16:24:59 GMT",
"version": "v1"
}
] |
2009-11-11
|
[
[
"Diehl",
"M.",
""
]
] |
The electromagnetic nucleon form factors provide constraints on generalized quark distributions. Key results of the study presented here are a strong dependence of the average impact parameter of quarks on their longitudinal momentum fraction, a striking difference in the t dependence of u and d quark contributions to elastic form factors, and an estimate of the orbital angular momentum carried by valence quarks in the nucleon.
|
1208.3162
|
Alejandro Ibarra
|
Dieter Hehn, Alejandro Ibarra
|
A radiative model with a naturally mild neutrino mass hierarchy
|
8 pages, 2 figures
| null |
10.1016/j.physletb.2012.11.034
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Many neutrino mass models postulate the existence of at least two extra
fermions in order to account for the measured solar and atmospheric mass
splittings. In these models, however, the predicted hierarchy between the two
mass splittings is generically much larger than the observed one, unless extra
flavor symmetries are introduced. We present in this letter a radiative
neutrino mass model consisting of the Standard Model extended by one heavy
fermionic singlet and two scalars which predicts, under very general
conditions, a neutrino mass hierarchy in qualitative agreement with the
experimental value.
|
[
{
"created": "Wed, 15 Aug 2012 17:24:25 GMT",
"version": "v1"
}
] |
2015-06-11
|
[
[
"Hehn",
"Dieter",
""
],
[
"Ibarra",
"Alejandro",
""
]
] |
Many neutrino mass models postulate the existence of at least two extra fermions in order to account for the measured solar and atmospheric mass splittings. In these models, however, the predicted hierarchy between the two mass splittings is generically much larger than the observed one, unless extra flavor symmetries are introduced. We present in this letter a radiative neutrino mass model consisting of the Standard Model extended by one heavy fermionic singlet and two scalars which predicts, under very general conditions, a neutrino mass hierarchy in qualitative agreement with the experimental value.
|
0805.3762
|
Bodo Lampe
|
Bodo Lampe
|
Further Development of the Tetron Model
|
24 pages, 5 tables
|
Found.Phys.39:215-236,2009; Erratum-ibid.40:573-574,2010
|
10.1007/s10701-009-9278-9 10.1007/s10701-010-9416-4
|
6/2008
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
After a prologue which clarifies some issues left open in my last paper, the
main features of the tetron model of elementary particles are discussed in the
light of recent developments, in particular the formation of strong and
electroweak vector bosons and a microscopic understanding of how the observed
tetrahedral symmetry of the fermion spectrum may arise.
|
[
{
"created": "Sat, 24 May 2008 13:25:31 GMT",
"version": "v1"
}
] |
2014-11-18
|
[
[
"Lampe",
"Bodo",
""
]
] |
After a prologue which clarifies some issues left open in my last paper, the main features of the tetron model of elementary particles are discussed in the light of recent developments, in particular the formation of strong and electroweak vector bosons and a microscopic understanding of how the observed tetrahedral symmetry of the fermion spectrum may arise.
|
0808.1680
|
Benjamin Fuks
|
B. Fuks, J. J. van der Bij, Q. Xu
|
High-dimensional Z' phenomenology at hadron colliders
|
9 pages, 8 figures; version accepted by Phys.Rev.D
|
Phys.Rev.D78:074016,2008
|
10.1103/PhysRevD.78.074016
|
FREIBURG PHENO-08-09
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study the phenomenology of a Z'-boson field coupled to hypercharge. The Z'
propagator has a non-trivial K\"all\'en-Lehmann spectral density due to the
mixing with a higher dimensional inert vector field. As a consequence detection
possibilities at hadron colliders are reduced. We determine the range of
parameters where this field can be studied at the Tevatron and the LHC through
its production cross section via the Drell-Yan mechanism.
|
[
{
"created": "Tue, 12 Aug 2008 15:11:25 GMT",
"version": "v1"
},
{
"created": "Tue, 7 Oct 2008 14:41:50 GMT",
"version": "v2"
}
] |
2008-11-26
|
[
[
"Fuks",
"B.",
""
],
[
"van der Bij",
"J. J.",
""
],
[
"Xu",
"Q.",
""
]
] |
We study the phenomenology of a Z'-boson field coupled to hypercharge. The Z' propagator has a non-trivial K\"all\'en-Lehmann spectral density due to the mixing with a higher dimensional inert vector field. As a consequence detection possibilities at hadron colliders are reduced. We determine the range of parameters where this field can be studied at the Tevatron and the LHC through its production cross section via the Drell-Yan mechanism.
|
1801.02734
|
Giovanna Cottin
|
Giovanna Cottin, Juan Carlos Helo, Martin Hirsch
|
Searches for light sterile neutrinos with multitrack displaced vertices
|
6 pages, 4 figures. v2: added references, corrected typos,
clarification on WR production in the abstract, extended arguments in the
introduction, section 2 and section 3. Results unchanged. Version accepted
for publication in PRD. v3 : New Figure 4, matches corrected version in PRD
|
Phys. Rev. D 97, 055025 (2018)
|
10.1103/PhysRevD.97.055025
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study discovery prospects for long-lived sterile neutrinos at the LHC with
multitrack displaced vertices, with masses below the electroweak scale. We
reinterpret current displaced vertex searches making use of publicly available,
parametrized selection efficiencies for modeling the detector response to
displaced vertices. We focus on production of right-handed $W_{R}$ bosons and
neutrinos $N$ in a left-right symmetric model, and find poor sensitivity. After
proposing a different trigger strategy (considering the prompt lepton
accompanying the neutrino displaced vertex) and optimized cuts in the invariant
mass and track multiplicity of the vertex, we find that the LHC with
$\sqrt{s}=13$ TeV and 300 fb$^{-1}$ is able to probe sterile neutrino masses
between $10\hspace{0.1cm}\mbox{GeV}<m_{N}<20$ GeV (for a right-handed gauge
boson mass of $2\hspace{0.1cm}\mbox{TeV}<m_{W_{R}}<3.5$ TeV). To probe higher
masses up to $m_{N}\sim 30$ GeV and $m_{W_{R}}<5$ TeV, 3000 fb$^{-1}$ will be
needed. This work joins other efforts in motivating dedicated experimental
searches to target this low sterile neutrino mass region.
|
[
{
"created": "Tue, 9 Jan 2018 00:51:36 GMT",
"version": "v1"
},
{
"created": "Thu, 1 Mar 2018 03:59:51 GMT",
"version": "v2"
},
{
"created": "Fri, 22 Mar 2019 04:25:00 GMT",
"version": "v3"
}
] |
2019-03-25
|
[
[
"Cottin",
"Giovanna",
""
],
[
"Helo",
"Juan Carlos",
""
],
[
"Hirsch",
"Martin",
""
]
] |
We study discovery prospects for long-lived sterile neutrinos at the LHC with multitrack displaced vertices, with masses below the electroweak scale. We reinterpret current displaced vertex searches making use of publicly available, parametrized selection efficiencies for modeling the detector response to displaced vertices. We focus on production of right-handed $W_{R}$ bosons and neutrinos $N$ in a left-right symmetric model, and find poor sensitivity. After proposing a different trigger strategy (considering the prompt lepton accompanying the neutrino displaced vertex) and optimized cuts in the invariant mass and track multiplicity of the vertex, we find that the LHC with $\sqrt{s}=13$ TeV and 300 fb$^{-1}$ is able to probe sterile neutrino masses between $10\hspace{0.1cm}\mbox{GeV}<m_{N}<20$ GeV (for a right-handed gauge boson mass of $2\hspace{0.1cm}\mbox{TeV}<m_{W_{R}}<3.5$ TeV). To probe higher masses up to $m_{N}\sim 30$ GeV and $m_{W_{R}}<5$ TeV, 3000 fb$^{-1}$ will be needed. This work joins other efforts in motivating dedicated experimental searches to target this low sterile neutrino mass region.
|
2405.08724
|
Pouya Bakhti
|
Pouya Bakhti, Min-Gwa Park, Meshkat Rajaee, Chang Sub Shin, Seodong
Shin
|
Revisiting Reactor Anti-Neutrino 5 MeV Bump with $^{13}$C
Neutral-Current Interaction
|
6 pages, 3 figures
| null | null | null |
hep-ph hep-ex
|
http://creativecommons.org/licenses/by/4.0/
|
For the first time, we systematically investigate the potential of
neutrino-nucleus neutral current interactions with $^{13}$C to identify the
origin of the 5 MeV bump observed in reactor anti-neutrino spectra in the
inverse beta decay process. The distinctive signal is obtained from the
de-excitation of $^{13}$C$^*$ into the ground state emitting a 3.685 MeV photon
in various liquid scintillator detectors. Such an interaction predominantly
occurs for the reactor anti-neutrinos within the energy range coinciding with
the 5 MeV bump. For a detector that has a capability of 95\% level photon and
electron separation and small thorium contamination below $5 \times 10^{-17}$
gr/gr located in a site with an overburden of about a few hundred m.w.e, such
as the location of near detectors of RENO and Daya Bay will have a great
sensitivity to resolve the 5 MeV bump. In addition, we propose a novel approach
to track the time evolution of reactor isotopes by analyzing our $^{13}$C
signal shedding light on the contributions from $^{235}$U or $^{239}$Pu to the
observed bump. This provides an extra powerful tool in both discriminating the
flux models and testing any new physics possibilities for the 5 MeV bump at
3$\sigma$ to 5$\sigma$ level with much less systematic uncertainties and
assuming 10 kt.year of data collection. Our detector requirements are
realistic, aligning well with recent studies conducted for existing or
forthcoming experiments.
|
[
{
"created": "Tue, 14 May 2024 16:09:52 GMT",
"version": "v1"
}
] |
2024-05-15
|
[
[
"Bakhti",
"Pouya",
""
],
[
"Park",
"Min-Gwa",
""
],
[
"Rajaee",
"Meshkat",
""
],
[
"Shin",
"Chang Sub",
""
],
[
"Shin",
"Seodong",
""
]
] |
For the first time, we systematically investigate the potential of neutrino-nucleus neutral current interactions with $^{13}$C to identify the origin of the 5 MeV bump observed in reactor anti-neutrino spectra in the inverse beta decay process. The distinctive signal is obtained from the de-excitation of $^{13}$C$^*$ into the ground state emitting a 3.685 MeV photon in various liquid scintillator detectors. Such an interaction predominantly occurs for the reactor anti-neutrinos within the energy range coinciding with the 5 MeV bump. For a detector that has a capability of 95\% level photon and electron separation and small thorium contamination below $5 \times 10^{-17}$ gr/gr located in a site with an overburden of about a few hundred m.w.e, such as the location of near detectors of RENO and Daya Bay will have a great sensitivity to resolve the 5 MeV bump. In addition, we propose a novel approach to track the time evolution of reactor isotopes by analyzing our $^{13}$C signal shedding light on the contributions from $^{235}$U or $^{239}$Pu to the observed bump. This provides an extra powerful tool in both discriminating the flux models and testing any new physics possibilities for the 5 MeV bump at 3$\sigma$ to 5$\sigma$ level with much less systematic uncertainties and assuming 10 kt.year of data collection. Our detector requirements are realistic, aligning well with recent studies conducted for existing or forthcoming experiments.
|
2305.00614
|
Danny Marfatia
|
Alakabha Datta, Danny Marfatia, Lopamudra Mukherjee
|
Hint of a new scalar interaction in LHCb data?
|
7 pages, 2 figures, 3 tables
|
Eur. Phys. J. C 84, 556 (2024)
|
10.1140/epjc/s10052-024-12890-8
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We explain recent LHCb measurements of the lepton universality ratios,
$R_{D^{(*)}}^{\tau/\ell}\equiv \frac{\mathcal{B}(\bar B \to D^{(*)+} \tau^-
\bar\nu_\tau)} {\mathcal{B}(\bar B \to D^{(*)+}\ell^- \bar\nu_\ell)}$ and
${R(\Lambda_c^+)}^{\tau/\ell} \equiv \frac{\mathcal{B}(\Lambda_b \to
\Lambda_c^+ \tau^- \bar{\nu}_{\tau})}{\mathcal{B}(\Lambda_b \to \Lambda_c^+
\ell^- \bar{\nu}_{\ell})}$ with $\ell=\mu$, via new physics that affects
$R_D^{\tau/\ell}$ and $R(\Lambda_c^+)^{\tau/\ell}$ but not
$R_{D^*}^{\tau/\ell}$. The scalar operator in the effective theory for new
physics is indicated. We find that the forward-backward asymmetry and $\tau$
polarization in $\bar{B} \to D^+ \tau^{-} \bar{\nu}_{\tau}$ and $\Lambda_b \to
\Lambda_c^+ \tau^- \bar{\nu}_{\tau}$ decays are significantly affected by the
scalar interaction. We construct a simple two Higgs doublet model as a
realization of our scenario and consider lepton universality in semileptonic
charm and top decays, radiative $B$ decay, $B$-mixing, and $Z \to b \bar b$.
|
[
{
"created": "Mon, 1 May 2023 00:46:51 GMT",
"version": "v1"
},
{
"created": "Mon, 8 May 2023 05:44:53 GMT",
"version": "v2"
},
{
"created": "Sat, 10 Feb 2024 18:31:37 GMT",
"version": "v3"
}
] |
2024-06-05
|
[
[
"Datta",
"Alakabha",
""
],
[
"Marfatia",
"Danny",
""
],
[
"Mukherjee",
"Lopamudra",
""
]
] |
We explain recent LHCb measurements of the lepton universality ratios, $R_{D^{(*)}}^{\tau/\ell}\equiv \frac{\mathcal{B}(\bar B \to D^{(*)+} \tau^- \bar\nu_\tau)} {\mathcal{B}(\bar B \to D^{(*)+}\ell^- \bar\nu_\ell)}$ and ${R(\Lambda_c^+)}^{\tau/\ell} \equiv \frac{\mathcal{B}(\Lambda_b \to \Lambda_c^+ \tau^- \bar{\nu}_{\tau})}{\mathcal{B}(\Lambda_b \to \Lambda_c^+ \ell^- \bar{\nu}_{\ell})}$ with $\ell=\mu$, via new physics that affects $R_D^{\tau/\ell}$ and $R(\Lambda_c^+)^{\tau/\ell}$ but not $R_{D^*}^{\tau/\ell}$. The scalar operator in the effective theory for new physics is indicated. We find that the forward-backward asymmetry and $\tau$ polarization in $\bar{B} \to D^+ \tau^{-} \bar{\nu}_{\tau}$ and $\Lambda_b \to \Lambda_c^+ \tau^- \bar{\nu}_{\tau}$ decays are significantly affected by the scalar interaction. We construct a simple two Higgs doublet model as a realization of our scenario and consider lepton universality in semileptonic charm and top decays, radiative $B$ decay, $B$-mixing, and $Z \to b \bar b$.
|
1212.5325
|
Jian-Rong Zhang
|
Jian-Rong Zhang
|
$S$-wave $D^{(*)}N$ molecular states: $\Sigma_{c}(2800)$ and
$\Lambda_{c}(2940)^{+}$?
|
the version accepted for publication in Phys. Rev. D; more
discussions added; 12 pages, 8 eps figures
|
Phys. Rev. D. 89, 096006 (2014)
|
10.1103/PhysRevD.89.096006
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Theoretically, some works have proposed the hadronic resonances
$\Sigma_{c}(2800)$ and $\Lambda_{c}(2940)^{+}$ to be $S$-wave $DN$ and $D^{*}N$
molecular candidates, respectively. In the framework of QCD sum rules, we
investigate that whether $\Sigma_{c}(2800)$ and $\Lambda_{c}(2940)^{+}$ could
be explained as the $S$-wave $DN$ state with $J^{P}=\frac{1}{2}^{-}$ and the
$S$-wave $D^{*}N$ state with $J^{P}=\frac{3}{2}^{-}$, respectively.
Technically, contributions of operators up to dimension $12$ are included in
the operator product expansion (OPE). The final results are
$3.64\pm0.33~\mbox{GeV}$ and $3.73\pm0.35~\mbox{GeV}$ for the $S$-wave $DN$
state of $J^{P}=\frac{1}{2}^{-}$ and the $S$-wave $D^{*}N$ state of
$J^{P}=\frac{3}{2}^{-}$, respectively. They are somewhat bigger than the
experimental data of $\Sigma_{c}(2800)$ and $\Lambda_{c}(2940)^{+}$,
respectively. In view of that corresponding molecular currents are constructed
from local operators of hadrons, the possibility of $\Sigma_c(2800)$ and
$\Lambda_{c}(2940)^{+}$ as molecular states can not be arbitrarily excluded
merely from these disagreements between molecular masses using local currents
and experimental data. But then these results imply that $\Sigma_{c}(2800)$ and
$\Lambda_{c}(2940)^{+}$ could not be compact states. This may suggest a
limitation of the QCD sum rule using the local current to determine whether
some state is a molecular state or not. As byproducts, masses for their bottom
partners are predicted to be $6.97\pm0.34~\mbox{GeV}$ for the $S$-wave
$\bar{B}N$ state of $J^{P}=\frac{1}{2}^{-}$ and $6.98\pm0.34~\mbox{GeV}$ for
the $S$-wave $\bar{B}^{*}N$ state of $J^{P}=\frac{3}{2}^{-}$.
|
[
{
"created": "Fri, 21 Dec 2012 03:29:44 GMT",
"version": "v1"
},
{
"created": "Thu, 1 May 2014 17:56:16 GMT",
"version": "v2"
}
] |
2014-05-16
|
[
[
"Zhang",
"Jian-Rong",
""
]
] |
Theoretically, some works have proposed the hadronic resonances $\Sigma_{c}(2800)$ and $\Lambda_{c}(2940)^{+}$ to be $S$-wave $DN$ and $D^{*}N$ molecular candidates, respectively. In the framework of QCD sum rules, we investigate that whether $\Sigma_{c}(2800)$ and $\Lambda_{c}(2940)^{+}$ could be explained as the $S$-wave $DN$ state with $J^{P}=\frac{1}{2}^{-}$ and the $S$-wave $D^{*}N$ state with $J^{P}=\frac{3}{2}^{-}$, respectively. Technically, contributions of operators up to dimension $12$ are included in the operator product expansion (OPE). The final results are $3.64\pm0.33~\mbox{GeV}$ and $3.73\pm0.35~\mbox{GeV}$ for the $S$-wave $DN$ state of $J^{P}=\frac{1}{2}^{-}$ and the $S$-wave $D^{*}N$ state of $J^{P}=\frac{3}{2}^{-}$, respectively. They are somewhat bigger than the experimental data of $\Sigma_{c}(2800)$ and $\Lambda_{c}(2940)^{+}$, respectively. In view of that corresponding molecular currents are constructed from local operators of hadrons, the possibility of $\Sigma_c(2800)$ and $\Lambda_{c}(2940)^{+}$ as molecular states can not be arbitrarily excluded merely from these disagreements between molecular masses using local currents and experimental data. But then these results imply that $\Sigma_{c}(2800)$ and $\Lambda_{c}(2940)^{+}$ could not be compact states. This may suggest a limitation of the QCD sum rule using the local current to determine whether some state is a molecular state or not. As byproducts, masses for their bottom partners are predicted to be $6.97\pm0.34~\mbox{GeV}$ for the $S$-wave $\bar{B}N$ state of $J^{P}=\frac{1}{2}^{-}$ and $6.98\pm0.34~\mbox{GeV}$ for the $S$-wave $\bar{B}^{*}N$ state of $J^{P}=\frac{3}{2}^{-}$.
|
2107.07890
|
Roberto A. Morales
|
Maria J. Herrero and Roberto A. Morales
|
One-loop renormalization of VBS with the electroweak chiral Lagrangian
in covariant gauges
|
Published version. 37 pages + 4 appendices, 13 figures, 5 tables
|
Phys. Rev. D 104 (2021), 075013
|
10.1103/PhysRevD.104.075013
|
IFT-UAM/CSIC-21-30
|
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
This work presents a first full one-loop computation of vector boson
scattering (VBS) within the non-linear effective field theory given by the
bosonic sector of the usually called electroweak chiral Lagrangian (EChL). The
computation is performed in the most general case of covariant $R_\xi$ gauges
and is compared through all this work with the Standard Model case, whose
computation in these covariant gauges is also novel and is presented also here.
The calculation of the one-loop VBS amplitude is performed using the
diagrammatic method by means of the one-particle-irreducible (1PI) Green
functions that are involved in these scattering processes. The central part of
this work is then devoted to the renormalization of all the n-legs one-loop 1PI
Green functions involved. This renormalization is performed in the most general
off-shell case with arbitrary external legs momenta. We then describe in full
detail the renormalization program, which within this context of the EChL,
implies to derive all the counterterms for both the electroweak parameters,
like boson masses and gauge couplings, and those for the EChL coefficients.
These later are crucial for the renormalization of the new divergences
typically appearing when computing loops with the lowest chiral dimension
Lagrangian. We present here the full list of involved divergences and
counterterms in the $R_\xi$ gauges and derive the complete set of
renormalization group equations for the EChL coefficients. In the last part of
this work, we present the EChL numerical results for the one-loop cross section
in the WZ channel and compare them with the SM results.
|
[
{
"created": "Fri, 16 Jul 2021 13:23:05 GMT",
"version": "v1"
},
{
"created": "Wed, 20 Oct 2021 19:07:20 GMT",
"version": "v2"
}
] |
2021-10-22
|
[
[
"Herrero",
"Maria J.",
""
],
[
"Morales",
"Roberto A.",
""
]
] |
This work presents a first full one-loop computation of vector boson scattering (VBS) within the non-linear effective field theory given by the bosonic sector of the usually called electroweak chiral Lagrangian (EChL). The computation is performed in the most general case of covariant $R_\xi$ gauges and is compared through all this work with the Standard Model case, whose computation in these covariant gauges is also novel and is presented also here. The calculation of the one-loop VBS amplitude is performed using the diagrammatic method by means of the one-particle-irreducible (1PI) Green functions that are involved in these scattering processes. The central part of this work is then devoted to the renormalization of all the n-legs one-loop 1PI Green functions involved. This renormalization is performed in the most general off-shell case with arbitrary external legs momenta. We then describe in full detail the renormalization program, which within this context of the EChL, implies to derive all the counterterms for both the electroweak parameters, like boson masses and gauge couplings, and those for the EChL coefficients. These later are crucial for the renormalization of the new divergences typically appearing when computing loops with the lowest chiral dimension Lagrangian. We present here the full list of involved divergences and counterterms in the $R_\xi$ gauges and derive the complete set of renormalization group equations for the EChL coefficients. In the last part of this work, we present the EChL numerical results for the one-loop cross section in the WZ channel and compare them with the SM results.
|
1206.5310
|
Satoshi Nakamura
|
Satoshi X. Nakamura (Jefferson Lab)
|
Meson spectroscopy with unitary coupled-channels model for heavy-meson
decay into three mesons
|
6 pages, 8 figures, Contribution to the Sixth International
Conference on Quarks and Nuclear Physics (QNP2012), April 16-20, 2012, Ecole
Polytechnique, Palaiseau, France
| null | null | null |
hep-ph hep-ex nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We develop a model for describing excited mesons decay into three mesons. The
properties of the excited mesons can be extracted with this model. The model
maintains the three-body unitarity that has been missed in previous data
analyses based on the conventional isobar models. We study an importance of the
three-body unitarity in extracting hadron properties from data. For this
purpose, we use the unitary and isobar models to analyze the same pseudo data
of gamma p -> pi+pi+pi-n, and extract the properties of excited mesons. We find
a significant difference between the unitary and isobar models in the extracted
properties of excited mesons, such as the mass, width and coupling strength to
decay channels.
|
[
{
"created": "Thu, 21 Jun 2012 04:16:44 GMT",
"version": "v1"
}
] |
2012-06-26
|
[
[
"Nakamura",
"Satoshi X.",
"",
"Jefferson Lab"
]
] |
We develop a model for describing excited mesons decay into three mesons. The properties of the excited mesons can be extracted with this model. The model maintains the three-body unitarity that has been missed in previous data analyses based on the conventional isobar models. We study an importance of the three-body unitarity in extracting hadron properties from data. For this purpose, we use the unitary and isobar models to analyze the same pseudo data of gamma p -> pi+pi+pi-n, and extract the properties of excited mesons. We find a significant difference between the unitary and isobar models in the extracted properties of excited mesons, such as the mass, width and coupling strength to decay channels.
|
hep-ph/0411222
|
Fei Huang
|
F. Huang, Z.Y. Zhang, Y.W. Yu
|
N K Pi molecular state with I=1 and J(Pi)=3/2-
|
11 pages, 3 figures; accepted for publication in Phys. Rev. C
|
Phys.Rev.C72:065208,2005
|
10.1103/PhysRevC.72.065208
| null |
hep-ph hep-ex nucl-th
| null |
The structure of the molecule-like state of $NK\pi$ with spin-parity
$J^{\pi}={3/2}^-$ and isospin I=1 is studied within the chiral SU(3) quark
model. First we calculate the $NK$, $N\pi$, and $K\pi$ phase shifts in the
framework of the resonating group method (RGM), and a qualitative agreement
with the experimental data is obtained. Then we perform a rough estimation for
the energy of $(NK\pi)_{J^{\pi}={3/2}^-,I=1}$, and the effect of the mixing to
the configuration $(\Delta K)_{J^{\pi}={3/2}^-,I=1}$ is also considered. The
calculated energy is very close to the threshold of the $NK\pi$ system. A
detailed investigation is worth doing in the further study.
|
[
{
"created": "Wed, 17 Nov 2004 02:13:45 GMT",
"version": "v1"
},
{
"created": "Mon, 21 Nov 2005 14:51:36 GMT",
"version": "v2"
},
{
"created": "Wed, 21 Dec 2005 14:25:41 GMT",
"version": "v3"
}
] |
2008-11-26
|
[
[
"Huang",
"F.",
""
],
[
"Zhang",
"Z. Y.",
""
],
[
"Yu",
"Y. W.",
""
]
] |
The structure of the molecule-like state of $NK\pi$ with spin-parity $J^{\pi}={3/2}^-$ and isospin I=1 is studied within the chiral SU(3) quark model. First we calculate the $NK$, $N\pi$, and $K\pi$ phase shifts in the framework of the resonating group method (RGM), and a qualitative agreement with the experimental data is obtained. Then we perform a rough estimation for the energy of $(NK\pi)_{J^{\pi}={3/2}^-,I=1}$, and the effect of the mixing to the configuration $(\Delta K)_{J^{\pi}={3/2}^-,I=1}$ is also considered. The calculated energy is very close to the threshold of the $NK\pi$ system. A detailed investigation is worth doing in the further study.
|
hep-ph/9401242
| null |
Elena Accomando and Silvano Petrarca
|
Searching a doubly charged Higgs boson at Hera
|
9 pages, Prep. Univ. of Rome "La Sapienza" n. 980 15/11/1993 3
figures not included Latex file (PETRARCA@ROMA1.INFN.IT)
|
Phys.Lett. B323 (1994) 212-215
|
10.1016/0370-2693(94)90293-3
| null |
hep-ph
| null |
The production of a single exotic Higgs particle is studied at Hera. Within
the present limits on the Yukawa couplings this doubly charged particle,
suggested by the left-right symmetric models, can be observed at Hera up to
values of its mass of about 150 GeV.
|
[
{
"created": "Wed, 12 Jan 1994 08:23:00 GMT",
"version": "v1"
}
] |
2009-10-28
|
[
[
"Accomando",
"Elena",
""
],
[
"Petrarca",
"Silvano",
""
]
] |
The production of a single exotic Higgs particle is studied at Hera. Within the present limits on the Yukawa couplings this doubly charged particle, suggested by the left-right symmetric models, can be observed at Hera up to values of its mass of about 150 GeV.
|
hep-ph/9905208
|
Jeannerot
|
R. Jeannerot (ICTP, Trieste) and J. Lesgourgues (SISSA, Trieste)
|
Supersymmetry breaking and loop corrections at the end of inflation
|
minor corrections; version to be published in Phys. Rev. D
|
Phys.Rev. D62 (2000) 023514
|
10.1103/PhysRevD.62.023514
|
ICTP IC/99/43, SISSA 45/99/EP
|
hep-ph astro-ph hep-th
| null |
We show that quantum corrections to the effective potential in supersymmetric
hybrid inflation can be calculated all the way from the inflationary period -
when the Universe is dominated by a false vacuum energy density - till the
fields settle down to the global supersymmetric minimum of the potential. These
are crucial for getting a continuous description of the evolution of the
fields.
|
[
{
"created": "Mon, 3 May 1999 14:55:26 GMT",
"version": "v1"
},
{
"created": "Mon, 21 Feb 2000 11:23:29 GMT",
"version": "v2"
},
{
"created": "Wed, 23 Feb 2000 17:59:31 GMT",
"version": "v3"
}
] |
2009-10-31
|
[
[
"Jeannerot",
"R.",
"",
"ICTP, Trieste"
],
[
"Lesgourgues",
"J.",
"",
"SISSA, Trieste"
]
] |
We show that quantum corrections to the effective potential in supersymmetric hybrid inflation can be calculated all the way from the inflationary period - when the Universe is dominated by a false vacuum energy density - till the fields settle down to the global supersymmetric minimum of the potential. These are crucial for getting a continuous description of the evolution of the fields.
|
hep-ph/0602114
|
Paolo Amore Dr
|
Paolo Amore, Arturo De Pace, Jorge Lopez
|
Analytical approximations to the spectra of quark-antiquark potentials
|
12 pages, 4 figures, 1 table
|
J.Phys. G32 (2006) 1061-1072
|
10.1088/0954-3899/32/7/014
| null |
hep-ph
| null |
A method, recently devised to obtain analytical approximations to certain
classes of integrals, is used in combination with the WKB expansion to derive
accurate analytical expressions for the spectrum of quantum potentials. The
accuracy of our results is verified by comparing them both with the literature
on the subject and with the numerical results obtained with a Fortran code. As
an application of the method that we propose, we consider the meson
spectroscopy with various phenomenological potentials.
|
[
{
"created": "Mon, 13 Feb 2006 18:47:47 GMT",
"version": "v1"
}
] |
2009-11-11
|
[
[
"Amore",
"Paolo",
""
],
[
"De Pace",
"Arturo",
""
],
[
"Lopez",
"Jorge",
""
]
] |
A method, recently devised to obtain analytical approximations to certain classes of integrals, is used in combination with the WKB expansion to derive accurate analytical expressions for the spectrum of quantum potentials. The accuracy of our results is verified by comparing them both with the literature on the subject and with the numerical results obtained with a Fortran code. As an application of the method that we propose, we consider the meson spectroscopy with various phenomenological potentials.
|
hep-ph/0304261
|
Raymond R. Volkas
|
R. Foot and R. R. Volkas
|
Was ordinary matter synthesised from mirror matter? An attempt to
explain why $\Omega_{Baryon} \approx 0.2\Omega_{Dark}$
|
6 pages, RevTeX; minor changes and additional explanations; version
accepted by Phys Rev D Rapid Communications
|
Phys.Rev.D68:021304,2003
|
10.1103/PhysRevD.68.021304
| null |
hep-ph astro-ph
| null |
The cosmological dust has begun to settle. A likely picture is a universe
comprised (predominantly) of three components: ordinary baryons ($\Omega_B
\approx 0.05$), non-baryonic dark matter ($\Omega_{Dark} \approx 0.22$) and
dark energy ($\Omega_{\Lambda} \approx 0.7$). We suggest that the observed
similarity of the abundances of ordinary baryons and non-baryonic dark matter
($\Omega_{B}/\Omega_{Dark} \approx 0.20$) hints at an underlying similarity
between the fundamental properties of ordinary and dark matter particles. This
is necessarily the case if dark matter is identified with mirror matter. We
examine a specific mirror matter scenario where $\Omega_B/\Omega_{Dark} \approx
0.20$ is naturally obtained.
|
[
{
"created": "Mon, 28 Apr 2003 09:28:24 GMT",
"version": "v1"
},
{
"created": "Tue, 3 Jun 2003 00:35:44 GMT",
"version": "v2"
}
] |
2008-11-26
|
[
[
"Foot",
"R.",
""
],
[
"Volkas",
"R. R.",
""
]
] |
The cosmological dust has begun to settle. A likely picture is a universe comprised (predominantly) of three components: ordinary baryons ($\Omega_B \approx 0.05$), non-baryonic dark matter ($\Omega_{Dark} \approx 0.22$) and dark energy ($\Omega_{\Lambda} \approx 0.7$). We suggest that the observed similarity of the abundances of ordinary baryons and non-baryonic dark matter ($\Omega_{B}/\Omega_{Dark} \approx 0.20$) hints at an underlying similarity between the fundamental properties of ordinary and dark matter particles. This is necessarily the case if dark matter is identified with mirror matter. We examine a specific mirror matter scenario where $\Omega_B/\Omega_{Dark} \approx 0.20$ is naturally obtained.
|
2103.15117
|
Rohit Gupta
|
Shubahngi Jain, Rohit Gupta and Satyajit Jena
|
Study of Isothermal Compressibility and Speed of Sound in the Hadronic
Matter Formed in Heavy-Ion Collision using Unified Formalism
| null |
Universe 9 (2023) 4, 170
|
10.3390/universe9040170
| null |
hep-ph
|
http://creativecommons.org/licenses/by-nc-nd/4.0/
|
The thermodynamical quantities and response functions are useful to describe
the particle production in heavy-ion collisions as they reveal crucial
information about the produced system. While the study of isothermal
compressibility provides an inference about the viscosity of the medium, speed
of sound helps in understanding the equation of state. With an aim towards
understanding the system produced in the heavy-ion collision, we have made an
attempt to study isothermal compressibility and speed of sound as function of
charged particle multiplicity in heavy-ion collisions at $\sqrt{s_{NN}}$ =
$2.76$ TeV, $5.02$ TeV, and $5.44$ TeV using unified formalism.
|
[
{
"created": "Sun, 28 Mar 2021 12:46:30 GMT",
"version": "v1"
},
{
"created": "Thu, 6 Apr 2023 13:40:48 GMT",
"version": "v2"
}
] |
2023-04-07
|
[
[
"Jain",
"Shubahngi",
""
],
[
"Gupta",
"Rohit",
""
],
[
"Jena",
"Satyajit",
""
]
] |
The thermodynamical quantities and response functions are useful to describe the particle production in heavy-ion collisions as they reveal crucial information about the produced system. While the study of isothermal compressibility provides an inference about the viscosity of the medium, speed of sound helps in understanding the equation of state. With an aim towards understanding the system produced in the heavy-ion collision, we have made an attempt to study isothermal compressibility and speed of sound as function of charged particle multiplicity in heavy-ion collisions at $\sqrt{s_{NN}}$ = $2.76$ TeV, $5.02$ TeV, and $5.44$ TeV using unified formalism.
|
2112.11097
|
Giulio Gambuti
|
Fabrizio Caola, Amlan Chakraborty, Giulio Gambuti, Andreas von
Manteuffel, Lorenzo Tancredi
|
Three-loop gluon scattering in QCD and the gluon Regge trajectory
|
12 pages, 1 figure; v2: minor corrections
|
Phys.Rev.Lett. 128 (2022) 21, 212001
|
10.1103/PhysRevLett.128.212001
|
OUTP-21-28P, MSUHEP-21-035, TUM-HEP-1382/21
|
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We compute the three-loop helicity amplitudes for the scattering of four
gluons in QCD. We employ projectors in the 't Hooft-Veltman scheme and
construct the amplitudes from a minimal set of physical building blocks, which
allows us to keep the computational complexity under control. We obtain
relatively compact results that can be expressed in terms of harmonic
polylogarithms. In addition, we consider the Regge limit of our amplitude and
extract the gluon Regge trajectory in full three-loop QCD. This is the last
missing ingredient required for studying single-Reggeon exchanges at
next-to-next-to-leading logarithmic accuracy.
|
[
{
"created": "Tue, 21 Dec 2021 10:59:29 GMT",
"version": "v1"
},
{
"created": "Wed, 29 Nov 2023 12:25:58 GMT",
"version": "v2"
}
] |
2023-11-30
|
[
[
"Caola",
"Fabrizio",
""
],
[
"Chakraborty",
"Amlan",
""
],
[
"Gambuti",
"Giulio",
""
],
[
"von Manteuffel",
"Andreas",
""
],
[
"Tancredi",
"Lorenzo",
""
]
] |
We compute the three-loop helicity amplitudes for the scattering of four gluons in QCD. We employ projectors in the 't Hooft-Veltman scheme and construct the amplitudes from a minimal set of physical building blocks, which allows us to keep the computational complexity under control. We obtain relatively compact results that can be expressed in terms of harmonic polylogarithms. In addition, we consider the Regge limit of our amplitude and extract the gluon Regge trajectory in full three-loop QCD. This is the last missing ingredient required for studying single-Reggeon exchanges at next-to-next-to-leading logarithmic accuracy.
|
1003.1921
|
Andre Rubbia
|
A. Rubbia
|
A CERN-based high-intensity high-energy proton source for long baseline
neutrino oscillation experiments with next-generation large underground
detectors for proton decay searches and neutrino physics and astrophysics
|
16 pages, 5 figures, based on a document submitted to the CERN SPC
Panel on Future Neutrino Facilities (November 2009).
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The feasibility of a European next-generation very massive neutrino
observatory in seven potential candidate sites located at distances from CERN
ranging from 130 km to 2300 km, is being considered within the LAGUNA design
study. The study is providing a coordinated technical design and assessment of
the underground research infrastructure in the various sites, and its coherent
cost estimation. It aims at a prioritization of the sites within summer 2010
and a start of operation around 2020. In addition to a rich non-accelerator
based physics programme including the GUT-scale with proton decay searches, the
detection of a next-generation neutrino superbeam tuned to measure the
flavor-conversion oscillatory pattern (i.e. 1st and 2nd oscillation maxima)
would allow to complete our understanding of the leptonic mixing matrix, in
particular by determining the neutrino mass hierarchy and by studying
CP-violation in the leptonic sector, thereby addressing the outstanding puzzle
of the origin of the excess of matter over antimatter created in the very early
stages of evolution of the Universe. We focus on a multi-MW-power neutrino
superbeam (="hyperbeam") produced by high-intensity primary protons of energy
30$\div$50 GeV. We argue that this option is an effective way to establish long
baseline neutrino physics in Europe with the high-stake prospects of measuring
$\theta_{13}$ and addressing CP-violation in the leptonic sector.
|
[
{
"created": "Tue, 9 Mar 2010 16:29:08 GMT",
"version": "v1"
}
] |
2010-03-10
|
[
[
"Rubbia",
"A.",
""
]
] |
The feasibility of a European next-generation very massive neutrino observatory in seven potential candidate sites located at distances from CERN ranging from 130 km to 2300 km, is being considered within the LAGUNA design study. The study is providing a coordinated technical design and assessment of the underground research infrastructure in the various sites, and its coherent cost estimation. It aims at a prioritization of the sites within summer 2010 and a start of operation around 2020. In addition to a rich non-accelerator based physics programme including the GUT-scale with proton decay searches, the detection of a next-generation neutrino superbeam tuned to measure the flavor-conversion oscillatory pattern (i.e. 1st and 2nd oscillation maxima) would allow to complete our understanding of the leptonic mixing matrix, in particular by determining the neutrino mass hierarchy and by studying CP-violation in the leptonic sector, thereby addressing the outstanding puzzle of the origin of the excess of matter over antimatter created in the very early stages of evolution of the Universe. We focus on a multi-MW-power neutrino superbeam (="hyperbeam") produced by high-intensity primary protons of energy 30$\div$50 GeV. We argue that this option is an effective way to establish long baseline neutrino physics in Europe with the high-stake prospects of measuring $\theta_{13}$ and addressing CP-violation in the leptonic sector.
|
1204.1252
|
Alexander Lenz
|
Abdelhak Djouadi and Alexander Lenz
|
Sealing the fate of a fourth generation of fermions
|
8 pages, 3 figures; Discussion of the recent Higgs results in a Note
added
| null |
10.1016/j.physletb.2012.07.060
|
LPT-Orsay-12/31, CERN-PH-TH/2012-087
|
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The search for the effects of heavy fermions in the extension of the Standard
Model with a fourth generation is part of the experimental program of the
Tevatron and LHC experiments. Besides being directly produced, these states
affect drastically the production and decay properties of the Higgs boson. In
this note, we first reemphasize the known fact that in the case of a light and
long-lived fourth neutrino, the present collider searches do not permit to
exclude a Higgs boson with a mass below the WW threshold. In a second step, we
show that the recent results from the ATLAS and CMS collaborations which
observe an excess in the $\gamma \gamma$ and $4\ell^\pm$ search channels
corresponding to a Higgs boson with a mass $M_H \approx 125$ GeV, cannot rule
out the fourth generation possibility if the $H \to \gamma \gamma$ decay rate
is evaluated when naively implementing the leading ${\cal O}(G_F m_{f'}^2)$
electroweak corrections. Including the exact next-to-leading order electroweak
corrections leads to a strong suppression of the $H \to \gamma \gamma$ rate and
makes this channel unobservable with present data. Finally, we point out that
the observation by the Tevatron collaborations of a $\gsim 2\sigma$ excess in
the mass range $M_H = 115$-135 GeV in the channel $q\bar q \to WH \to Wb\bar b$
can definitely not be accommodated by the fourth generation fermion scenario.
All in all, if the excesses observed at the LHC and the Tevatron are indeed due
to a Higgs boson, they unambiguously exclude the perturbative fermionic fourth
generation case. In passing, we also point out that the Tevatron excess
definitely rules out the fermiophobic Higgs scenario as well as scenarios in
which the Higgs couplings to gauge bosons and bottom quarks are significantly
reduced.
|
[
{
"created": "Thu, 5 Apr 2012 15:10:18 GMT",
"version": "v1"
},
{
"created": "Wed, 4 Jul 2012 19:53:34 GMT",
"version": "v2"
}
] |
2015-06-04
|
[
[
"Djouadi",
"Abdelhak",
""
],
[
"Lenz",
"Alexander",
""
]
] |
The search for the effects of heavy fermions in the extension of the Standard Model with a fourth generation is part of the experimental program of the Tevatron and LHC experiments. Besides being directly produced, these states affect drastically the production and decay properties of the Higgs boson. In this note, we first reemphasize the known fact that in the case of a light and long-lived fourth neutrino, the present collider searches do not permit to exclude a Higgs boson with a mass below the WW threshold. In a second step, we show that the recent results from the ATLAS and CMS collaborations which observe an excess in the $\gamma \gamma$ and $4\ell^\pm$ search channels corresponding to a Higgs boson with a mass $M_H \approx 125$ GeV, cannot rule out the fourth generation possibility if the $H \to \gamma \gamma$ decay rate is evaluated when naively implementing the leading ${\cal O}(G_F m_{f'}^2)$ electroweak corrections. Including the exact next-to-leading order electroweak corrections leads to a strong suppression of the $H \to \gamma \gamma$ rate and makes this channel unobservable with present data. Finally, we point out that the observation by the Tevatron collaborations of a $\gsim 2\sigma$ excess in the mass range $M_H = 115$-135 GeV in the channel $q\bar q \to WH \to Wb\bar b$ can definitely not be accommodated by the fourth generation fermion scenario. All in all, if the excesses observed at the LHC and the Tevatron are indeed due to a Higgs boson, they unambiguously exclude the perturbative fermionic fourth generation case. In passing, we also point out that the Tevatron excess definitely rules out the fermiophobic Higgs scenario as well as scenarios in which the Higgs couplings to gauge bosons and bottom quarks are significantly reduced.
|
1903.00166
|
Seong Youl Choi
|
Seong Youl Choi, Jae Hoon Jeong, Ji Ho Song
|
General Spin Analysis from Angular Correlations in Two-Body Decays
|
43 pages, 9 figures
| null | null | null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Determining the spin of any new particle and measuring its couplings to other
particles and/or itself are crucial in reconstructing the structure of any
quantum field theory containing the particle. A general helicity formalism is
employed to describe the polarization of the particle $Y$ in a two-body decay
$X_2\to Y X_1$ with polarized $X_2$ for the purpose of diagnosing the dynamical
properties of three involved particles and for determining their spins
altogether. We perform a general and comprehensive analytic analysis with our
special focus on grasping fully how to connect the decay helicity amplitudes
and decay distributions in the $X_2$ rest frame and those in a laboratory frame
with $X_2$ moving with a non-zero velocity through Wick helicity rotation on
helicity states and amplitudes. This theoretical framework is demonstrated in a
detailed illustrative manner with the Standard Model (SM) processes, the
sequential process $e^-e^+\to Z\to \tau^-\tau^+$ followed by $\tau^-\to
\rho^-\nu_\tau\to (\pi^-\pi^0)\nu_\tau$ and the sequential process $e^-e^+\to
t\bar{t}$ followed by $t\to W^+ b \to (\ell^+\nu_\ell)b$, and one non-standard
decay process of a new vectorlike heavy top quark, $T\to Z t$, followed by
$Z\to \ell^-\ell^+$. All the useful formulas directly applicable to any
combinations of spins and any types of couplings in the two-body decay $X_2\to
Y X_1$ followed by suitable $Y$ two-body decays processes are collected and
described in detail.
|
[
{
"created": "Fri, 1 Mar 2019 06:05:10 GMT",
"version": "v1"
}
] |
2019-03-05
|
[
[
"Choi",
"Seong Youl",
""
],
[
"Jeong",
"Jae Hoon",
""
],
[
"Song",
"Ji Ho",
""
]
] |
Determining the spin of any new particle and measuring its couplings to other particles and/or itself are crucial in reconstructing the structure of any quantum field theory containing the particle. A general helicity formalism is employed to describe the polarization of the particle $Y$ in a two-body decay $X_2\to Y X_1$ with polarized $X_2$ for the purpose of diagnosing the dynamical properties of three involved particles and for determining their spins altogether. We perform a general and comprehensive analytic analysis with our special focus on grasping fully how to connect the decay helicity amplitudes and decay distributions in the $X_2$ rest frame and those in a laboratory frame with $X_2$ moving with a non-zero velocity through Wick helicity rotation on helicity states and amplitudes. This theoretical framework is demonstrated in a detailed illustrative manner with the Standard Model (SM) processes, the sequential process $e^-e^+\to Z\to \tau^-\tau^+$ followed by $\tau^-\to \rho^-\nu_\tau\to (\pi^-\pi^0)\nu_\tau$ and the sequential process $e^-e^+\to t\bar{t}$ followed by $t\to W^+ b \to (\ell^+\nu_\ell)b$, and one non-standard decay process of a new vectorlike heavy top quark, $T\to Z t$, followed by $Z\to \ell^-\ell^+$. All the useful formulas directly applicable to any combinations of spins and any types of couplings in the two-body decay $X_2\to Y X_1$ followed by suitable $Y$ two-body decays processes are collected and described in detail.
|
1808.05450
|
Gabriela Vitti Stenico
|
G. V. Stenico, D. V. Forero and O. L. G. Peres
|
A Short Travel for Neutrinos in Large Extra Dimensions
|
21 pages, 6 figures, 2 tables
| null |
10.1007/JHEP11(2018)155
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Neutrino oscillations successfully explain the flavor transitions observed in
neutrinos produced in natural sources like the center of the sun and the earth
atmosphere, and also from man-made sources like reactors and accelerators.
These oscillations are driven by two mass-squared differences, solar and
atmospheric, at the sub-eV scale. However, longstanding anomalies at
short-baselines might imply the existence of new oscillation frequencies at the
eV-scale and the possibility of this sterile state(s) to mix with the three
active neutrinos. One of the many future neutrino programs that are expected to
provide a final word on this issue is the Short-Baseline Neutrino Program (SBN)
at FERMILAB. In this letter, we consider a specific model of Large Extra
Dimensions (LED) which provides interesting signatures of oscillation of extra
sterile states. We started re-creating sensitivity analyses for sterile
neutrinos in the 3+1 scenario, previously done by the SBN collaboration, by
simulating neutrino events in the three SBN detectors from both muon neutrino
disappearance and electron neutrino appearance. Then, we implemented neutrino
oscillations as predicted in the LED model and also we have performed
sensitivity analysis to the LED parameters. Finally, we studied the SBN power
of discriminating between the two models, the 3+1 and the LED. We have found
that SBN is sensitive to the oscillations predicted in the LED model and have
the potential to constrain the LED parameter space better than any other
oscillation experiment, for $m_{1}^D<0.1\,\text{eV}$. In case SBN observes a
departure from the three active neutrino framework, it also has the power of
discriminating between sterile oscillations predicted in the 3+1 framework and
the LED ones.
|
[
{
"created": "Thu, 16 Aug 2018 12:43:18 GMT",
"version": "v1"
},
{
"created": "Tue, 28 Aug 2018 19:48:13 GMT",
"version": "v2"
}
] |
2018-12-05
|
[
[
"Stenico",
"G. V.",
""
],
[
"Forero",
"D. V.",
""
],
[
"Peres",
"O. L. G.",
""
]
] |
Neutrino oscillations successfully explain the flavor transitions observed in neutrinos produced in natural sources like the center of the sun and the earth atmosphere, and also from man-made sources like reactors and accelerators. These oscillations are driven by two mass-squared differences, solar and atmospheric, at the sub-eV scale. However, longstanding anomalies at short-baselines might imply the existence of new oscillation frequencies at the eV-scale and the possibility of this sterile state(s) to mix with the three active neutrinos. One of the many future neutrino programs that are expected to provide a final word on this issue is the Short-Baseline Neutrino Program (SBN) at FERMILAB. In this letter, we consider a specific model of Large Extra Dimensions (LED) which provides interesting signatures of oscillation of extra sterile states. We started re-creating sensitivity analyses for sterile neutrinos in the 3+1 scenario, previously done by the SBN collaboration, by simulating neutrino events in the three SBN detectors from both muon neutrino disappearance and electron neutrino appearance. Then, we implemented neutrino oscillations as predicted in the LED model and also we have performed sensitivity analysis to the LED parameters. Finally, we studied the SBN power of discriminating between the two models, the 3+1 and the LED. We have found that SBN is sensitive to the oscillations predicted in the LED model and have the potential to constrain the LED parameter space better than any other oscillation experiment, for $m_{1}^D<0.1\,\text{eV}$. In case SBN observes a departure from the three active neutrino framework, it also has the power of discriminating between sterile oscillations predicted in the 3+1 framework and the LED ones.
|
1302.0518
|
Alexander Nesterenko
|
A.V. Nesterenko
|
Inclusive tau lepton decay: the effects due to hadronization
|
Talk given at 10th International Conference on Quark Confinement and
the Hadron Spectrum, 8 - 12 October 2012, Munich, Germany; 8 pages, 3 figures
|
PoS ConfinementX, 350 (2013)
| null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The inclusive tau lepton hadronic decay and its description within Dispersive
approach to Quantum Chromodynamics are briefly discussed.
|
[
{
"created": "Sun, 3 Feb 2013 18:04:36 GMT",
"version": "v1"
}
] |
2016-04-26
|
[
[
"Nesterenko",
"A. V.",
""
]
] |
The inclusive tau lepton hadronic decay and its description within Dispersive approach to Quantum Chromodynamics are briefly discussed.
|
hep-ph/9703249
|
Takashi Satou
|
T. Morozumi, T. Satou, M. N. Rebelo, M. Tanimoto
|
The top quark mass and flavor mixing in a Seesaw model of Quark Masses
|
13 pgs. LaTeX form
|
Phys.Lett.B410:233-240,1997
|
10.1016/S0370-2693(97)01021-6
|
HUPD-9704, FISIST/6-97/CFIF
|
hep-ph
| null |
The top quark mass and the flavor mixing are studied in the context of a
Seesaw model of Quark Masses based on the gauge group $SU(2)_L \times SU(2)_R
\times U(1)$. Six isosinglet quarks are introduced to give rise to the mass
hierarchy of ordinary quarks. In this scheme, we reexamine a mechanism for the
generation of the top quark mass. It is shown that, in order to prevent the
Seesaw mechanism to act for the top quark, the mass parameter of its isosinglet
partner must be much smaller than the breaking scale of $SU(2)_R$. As a result
the fourth lightest up quark must have a mass of the order of the breaking
scale of $SU(2)_R$, and a large mixing between the right-handed top quark and
its singlet partner occurs. We also show that this mechanism is compatible with
the mass spectrum of light quarks and their flavor mixing.
|
[
{
"created": "Thu, 6 Mar 1997 05:13:06 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Morozumi",
"T.",
""
],
[
"Satou",
"T.",
""
],
[
"Rebelo",
"M. N.",
""
],
[
"Tanimoto",
"M.",
""
]
] |
The top quark mass and the flavor mixing are studied in the context of a Seesaw model of Quark Masses based on the gauge group $SU(2)_L \times SU(2)_R \times U(1)$. Six isosinglet quarks are introduced to give rise to the mass hierarchy of ordinary quarks. In this scheme, we reexamine a mechanism for the generation of the top quark mass. It is shown that, in order to prevent the Seesaw mechanism to act for the top quark, the mass parameter of its isosinglet partner must be much smaller than the breaking scale of $SU(2)_R$. As a result the fourth lightest up quark must have a mass of the order of the breaking scale of $SU(2)_R$, and a large mixing between the right-handed top quark and its singlet partner occurs. We also show that this mechanism is compatible with the mass spectrum of light quarks and their flavor mixing.
|
1504.05937
|
Koichi Hamaguchi
|
Koichi Hamaguchi, Takeo Moroi, Kazunori Nakayama
|
AMS-02 Antiprotons from Annihilating or Decaying Dark Matter
|
12 pages, 3 figures
| null | null |
UT-15-14, IPMU-15-0055
|
hep-ph astro-ph.CO
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Recently the AMS-02 experiment reported an excess of cosmic ray antiprotons
over the expected astrophysical background. We interpret the excess as a signal
from annihilating or decaying dark matter and find that the observed spectrum
is well fitted by adding contributions from the annihilation or decay of dark
matter with mass of O(TeV) or larger. Interestingly, Wino dark matter with mass
of around 3 TeV, whose thermal relic abundance is consistent with present dark
matter abundance, can explain the antiproton excess. We also discuss the
implications for the decaying gravitino dark matter with R-parity violation.
|
[
{
"created": "Wed, 22 Apr 2015 19:42:00 GMT",
"version": "v1"
}
] |
2015-04-23
|
[
[
"Hamaguchi",
"Koichi",
""
],
[
"Moroi",
"Takeo",
""
],
[
"Nakayama",
"Kazunori",
""
]
] |
Recently the AMS-02 experiment reported an excess of cosmic ray antiprotons over the expected astrophysical background. We interpret the excess as a signal from annihilating or decaying dark matter and find that the observed spectrum is well fitted by adding contributions from the annihilation or decay of dark matter with mass of O(TeV) or larger. Interestingly, Wino dark matter with mass of around 3 TeV, whose thermal relic abundance is consistent with present dark matter abundance, can explain the antiproton excess. We also discuss the implications for the decaying gravitino dark matter with R-parity violation.
|
1111.1220
|
Frank Siegert
|
Stefan Hoeche, Frank Krauss, Marek Schonherr, Frank Siegert
|
A critical appraisal of NLO+PS matching methods
|
34 pages, 25 figures; v2 as accepted for publication in JHEP
|
JHEP09(2012)049
|
10.1007/JHEP09(2012)049
|
SLAC-PUB 14661; IPPP/11/67; DCPT/11/134; LPN11-58;
FR-PHENO-2011-019; MCNET-11-24
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In this publication, uncertainties in and differences between the MC@NLO and
POWHEG methods for matching next-to-leading order QCD calculations with parton
showers are discussed. Implementations of both algorithms within the event
generator Sherpa and based on Catani-Seymour subtraction are employed to assess
the impact on a representative selection of observables. In the case of MC@NLO
a substantial simplification is achieved by using dipole subtraction terms to
generate the first emission. A phase space restriction is employed, which
allows to vary in a transparent way the amount of non-singular radiative
corrections that are exponentiated. Effects on various observables are
investigated, using the production of a Higgs boson in gluon fusion, with or
without an associated jet, as a benchmark process. The case of H+jet production
is presented for the first time in an NLO+PS matched simulation. Uncertainties
due to scale choices and non-perturbative effects are explored in the
production of W and Z bosons in association with a jet. Corresponding results
are compared to data from the Tevatron and LHC experiments.
|
[
{
"created": "Fri, 4 Nov 2011 19:28:26 GMT",
"version": "v1"
},
{
"created": "Mon, 24 Sep 2012 07:37:07 GMT",
"version": "v2"
}
] |
2012-09-25
|
[
[
"Hoeche",
"Stefan",
""
],
[
"Krauss",
"Frank",
""
],
[
"Schonherr",
"Marek",
""
],
[
"Siegert",
"Frank",
""
]
] |
In this publication, uncertainties in and differences between the MC@NLO and POWHEG methods for matching next-to-leading order QCD calculations with parton showers are discussed. Implementations of both algorithms within the event generator Sherpa and based on Catani-Seymour subtraction are employed to assess the impact on a representative selection of observables. In the case of MC@NLO a substantial simplification is achieved by using dipole subtraction terms to generate the first emission. A phase space restriction is employed, which allows to vary in a transparent way the amount of non-singular radiative corrections that are exponentiated. Effects on various observables are investigated, using the production of a Higgs boson in gluon fusion, with or without an associated jet, as a benchmark process. The case of H+jet production is presented for the first time in an NLO+PS matched simulation. Uncertainties due to scale choices and non-perturbative effects are explored in the production of W and Z bosons in association with a jet. Corresponding results are compared to data from the Tevatron and LHC experiments.
|
2211.10557
|
Tania Robens
|
Tania Robens
|
LHC Benchmark scenarios in the TRSM
|
4 pages, 2 figures; proceedings of 41st International Conference on
High Energy physics - ICHEP2022
| null | null |
RBI-ThPhys-2022-45
|
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
The TRSM is a new physics model that extends the scalar sector of the
Standard Model by two additional CP even scalars. It leads to a large variety
of interesting signatures, some of which have not yet been explored by the LHC
experiments. I will also discuss the option to explore the hhh final state
within this model.
|
[
{
"created": "Thu, 17 Nov 2022 15:38:33 GMT",
"version": "v1"
}
] |
2022-11-22
|
[
[
"Robens",
"Tania",
""
]
] |
The TRSM is a new physics model that extends the scalar sector of the Standard Model by two additional CP even scalars. It leads to a large variety of interesting signatures, some of which have not yet been explored by the LHC experiments. I will also discuss the option to explore the hhh final state within this model.
|
hep-ph/9510207
|
A. A. Pivovarov
|
N.V. Krasnikov and A.A. Pivovarov
|
Running coupling at small momenta, renormalization schemes and
renormalons
|
revised version to be published in Yad. Fiz., misprints corrected,
references updated, 19 pages, latex
|
Phys.Atom.Nucl. 64 (2001) 1500-1507; Yad.Fiz. 64 (2001) 1576-1583
|
10.1134/1.1398943
|
INR-0903-95
|
hep-ph
| null |
We suggest a method of summing the perturbation theory (PT) asymptotic series
related to infrared (IR) renormalons in QCD by using special renormalization
schemes in which the running coupling can be integrated over the region of
small momenta. For the method to work, one should consider higher order PT
corrections to the standard bubble-chain diagrams. High-order corrections allow
one to choose a scheme in which the coupling evolution can smoothly be
extrapolated to small momenta. In such schemes the sum of an (extended)
IR-renormalon asymptotic series is defined as an integral of the running
coupling over the IR region. We give explicit examples of renormalization
schemes in QCD which can be used for summing IR-renormalon asymptotic series
according to our definition.
|
[
{
"created": "Mon, 2 Oct 1995 15:30:54 GMT",
"version": "v1"
},
{
"created": "Sat, 18 Nov 2000 13:30:29 GMT",
"version": "v2"
}
] |
2009-10-28
|
[
[
"Krasnikov",
"N. V.",
""
],
[
"Pivovarov",
"A. A.",
""
]
] |
We suggest a method of summing the perturbation theory (PT) asymptotic series related to infrared (IR) renormalons in QCD by using special renormalization schemes in which the running coupling can be integrated over the region of small momenta. For the method to work, one should consider higher order PT corrections to the standard bubble-chain diagrams. High-order corrections allow one to choose a scheme in which the coupling evolution can smoothly be extrapolated to small momenta. In such schemes the sum of an (extended) IR-renormalon asymptotic series is defined as an integral of the running coupling over the IR region. We give explicit examples of renormalization schemes in QCD which can be used for summing IR-renormalon asymptotic series according to our definition.
|
hep-ph/0001305
|
Giovanni Amelino-Camelia
|
Giovanni Amelino-Camelia and Franco Buccella
|
Testing kappa-Poincare' with neutral kaons
|
9 pages, LaTex
|
Mod.Phys.Lett. A15 (2000) 2119-2128
|
10.1142/S0217732300002474
|
CERN-TH/2000-034
|
hep-ph
| null |
In recent work on experimental tests of quantum-gravity-motivated
phenomenological models, a significant role has been played by the so-called
``$\kappa$'' deformations of Poincar\'e symmetries. Sensitivity to values of
the relevant deformation length $\lambda$ as small as $5 \cdot 10^{-33}m$ has
been achieved in recent analyses comparing the structure of $\kappa$-Poincar\'e
symmetries with data on the gamma rays we detect from distant astrophysical
sources. We investigate violations of CPT symmetry which may be associated with
$\kappa$-Poincar\'e in the physics of the neutral-kaon system. A simple
estimate indicates that experiments on the neutral kaons may actually be more
$\lambda$-sensitive than corresponding astrophysical experiments, and may
already allow to probe values of $\lambda$ of order the Planck length.
|
[
{
"created": "Fri, 28 Jan 2000 23:44:04 GMT",
"version": "v1"
}
] |
2009-10-31
|
[
[
"Amelino-Camelia",
"Giovanni",
""
],
[
"Buccella",
"Franco",
""
]
] |
In recent work on experimental tests of quantum-gravity-motivated phenomenological models, a significant role has been played by the so-called ``$\kappa$'' deformations of Poincar\'e symmetries. Sensitivity to values of the relevant deformation length $\lambda$ as small as $5 \cdot 10^{-33}m$ has been achieved in recent analyses comparing the structure of $\kappa$-Poincar\'e symmetries with data on the gamma rays we detect from distant astrophysical sources. We investigate violations of CPT symmetry which may be associated with $\kappa$-Poincar\'e in the physics of the neutral-kaon system. A simple estimate indicates that experiments on the neutral kaons may actually be more $\lambda$-sensitive than corresponding astrophysical experiments, and may already allow to probe values of $\lambda$ of order the Planck length.
|
1104.2362
|
Kwanghyun Jo
|
Kwanghyun Jo, Mannque Rho, Yunseok Seo and Sang-Jin Sin
|
The Dropping of In-Medium Hadron Mass in Holographic QCD
|
20 pages, 7 figures
|
JHEP 1107:008,2011
|
10.1007/JHEP07(2011)008
| null |
hep-ph hep-th nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study the baryon density dependence of the vector meson spectrum using the
D4/D6 system together with the compact D4 baryon vertex. We find that the
vector meson mass decreases almost linearly in density at low density for small
quark mass, but saturates to a finite non-zero value for large density. We also
compute the density dependence of the $\eta\prime$ mass and the $\eta\prime$
velocity. We find that in medium, our model is consistent with the GMOR
relation up to a few times the normal nuclear density. We compare our hQCD
predictions with predictions made based on hidden local gauge theory that is
constructed to model QCD.
|
[
{
"created": "Wed, 13 Apr 2011 01:25:12 GMT",
"version": "v1"
}
] |
2015-03-19
|
[
[
"Jo",
"Kwanghyun",
""
],
[
"Rho",
"Mannque",
""
],
[
"Seo",
"Yunseok",
""
],
[
"Sin",
"Sang-Jin",
""
]
] |
We study the baryon density dependence of the vector meson spectrum using the D4/D6 system together with the compact D4 baryon vertex. We find that the vector meson mass decreases almost linearly in density at low density for small quark mass, but saturates to a finite non-zero value for large density. We also compute the density dependence of the $\eta\prime$ mass and the $\eta\prime$ velocity. We find that in medium, our model is consistent with the GMOR relation up to a few times the normal nuclear density. We compare our hQCD predictions with predictions made based on hidden local gauge theory that is constructed to model QCD.
|
2301.03607
|
Giulia Zanderighi
|
Paolo Nason and Giulia Zanderighi
|
Fits of $\alpha_s$ using power corrections in the three-jet region
|
38 pages, 9 figures
| null |
10.1007/JHEP06(2023)058
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In this work we study the impact of recent findings regarding
non-perturbative corrections in the three-jet region to $e^+e^-$ hadronic
observables, by performing a simultaneous fit of the strong coupling constant
$\alpha_s$ and the non-perturbative parameter $\alpha_0$. We extend the
calculation of these power corrections, already known for thrust and
C-parameter, to other $e^+e^-$ hadronic observables. We find that for some
observables the non-perturbative corrections are reasonably well behaved in the
two-jet limit, while for others they have a more problematic behaviour. If one
limits the fit to the three-jet region and to the well-behaved observables, one
finds in general very good results, with the extracted value of $\alpha_s$
agreeing well with the world average. This is the case in particular for the
thrust and $C$-parameter for which notably small values of $\alpha_s$ have been
reported when non-perturbative corrections have been computed using analytic
methods. Furthermore, the more problematic variables are also well described
provided one stays far enough from the two-jet limit, while in this same region
they cannot be described using the traditional implementation of
power-corrections based on two-jet kinematics.
|
[
{
"created": "Mon, 9 Jan 2023 19:00:01 GMT",
"version": "v1"
}
] |
2023-06-28
|
[
[
"Nason",
"Paolo",
""
],
[
"Zanderighi",
"Giulia",
""
]
] |
In this work we study the impact of recent findings regarding non-perturbative corrections in the three-jet region to $e^+e^-$ hadronic observables, by performing a simultaneous fit of the strong coupling constant $\alpha_s$ and the non-perturbative parameter $\alpha_0$. We extend the calculation of these power corrections, already known for thrust and C-parameter, to other $e^+e^-$ hadronic observables. We find that for some observables the non-perturbative corrections are reasonably well behaved in the two-jet limit, while for others they have a more problematic behaviour. If one limits the fit to the three-jet region and to the well-behaved observables, one finds in general very good results, with the extracted value of $\alpha_s$ agreeing well with the world average. This is the case in particular for the thrust and $C$-parameter for which notably small values of $\alpha_s$ have been reported when non-perturbative corrections have been computed using analytic methods. Furthermore, the more problematic variables are also well described provided one stays far enough from the two-jet limit, while in this same region they cannot be described using the traditional implementation of power-corrections based on two-jet kinematics.
|
1702.07840
|
Toshitaka Tatsumi
|
T. Tatsumi, R. Yoshiike, T.-G. Lee
|
Fluctuations In The Inhomogeneous Chiral Transition
|
8 pages, 3 figures, Proc. of INPC 2016. arXiv admin note: text
overlap with arXiv:1702.01511
| null | null | null |
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Chiral pair fluctuation are considered near the phase boundary of the
inhomogeneous chiral phase (iCP). The fluctuations are then bosonized and an
effective action for the chiral pair fluctuation is basically constructed by
considering the ring diagram of the polarization function. We can evaluate the
self-energy and effective four point interaction among fluctuations in a
consistent way. The peculiar dispersion of the fluctuation, reflecting the
spatially inhomogeneous transition, gives rise to interesting and qualitative
results. Thermal fluctuations prohibit the second-order transition, while the
effect of the quantum fluctuations is rather modest. Quantum and thermal
fluctuations changes the second-order transition to the first one by changing
the sign of the effective four-point interaction between effective mesons.
These features may be observed by relativistic heavy-ion collisions through the
analysis of the thermodynamic observables. Distinct from the second-order phase
transition, the first moment such as entropy production exhibits an anomalous
behavior due to fluctuations, which is one of the signals of the phase
transition to iCP. Some similar aspects are also remarked between iCP and the
FFLO state in superconductivity.
|
[
{
"created": "Sat, 25 Feb 2017 06:59:02 GMT",
"version": "v1"
}
] |
2017-02-28
|
[
[
"Tatsumi",
"T.",
""
],
[
"Yoshiike",
"R.",
""
],
[
"Lee",
"T. -G.",
""
]
] |
Chiral pair fluctuation are considered near the phase boundary of the inhomogeneous chiral phase (iCP). The fluctuations are then bosonized and an effective action for the chiral pair fluctuation is basically constructed by considering the ring diagram of the polarization function. We can evaluate the self-energy and effective four point interaction among fluctuations in a consistent way. The peculiar dispersion of the fluctuation, reflecting the spatially inhomogeneous transition, gives rise to interesting and qualitative results. Thermal fluctuations prohibit the second-order transition, while the effect of the quantum fluctuations is rather modest. Quantum and thermal fluctuations changes the second-order transition to the first one by changing the sign of the effective four-point interaction between effective mesons. These features may be observed by relativistic heavy-ion collisions through the analysis of the thermodynamic observables. Distinct from the second-order phase transition, the first moment such as entropy production exhibits an anomalous behavior due to fluctuations, which is one of the signals of the phase transition to iCP. Some similar aspects are also remarked between iCP and the FFLO state in superconductivity.
|
1306.3234
|
Sannino Francesco
|
Oleg Antipin, Marc Gillioz, Jens Krog, Esben M{\o}lgaard, Francesco
Sannino (CP3-Origins and DIAS)
|
Standard Model Vacuum Stability and Weyl Consistency Conditions
|
RevTeX, 13 pages, 5 figures
| null |
10.1007/JHEP08(2013)034
|
CP3-Origins-2013-20, DIAS-2013-20
|
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
At high energy the standard model possesses conformal symmetry at the
classical level. This is reflected at the quantum level by relations between
the different beta functions of the model. These relations are known as the
Weyl consistency conditions. We show that it is possible to satisfy them order
by order in perturbation theory, provided that a suitable coupling constant
counting scheme is used. As a direct phenomenological application, we study the
stability of the standard model vacuum at high energies and compare with
previous computations violating the Weyl consistency conditions.
|
[
{
"created": "Thu, 13 Jun 2013 20:01:05 GMT",
"version": "v1"
}
] |
2015-06-16
|
[
[
"Antipin",
"Oleg",
"",
"CP3-Origins and DIAS"
],
[
"Gillioz",
"Marc",
"",
"CP3-Origins and DIAS"
],
[
"Krog",
"Jens",
"",
"CP3-Origins and DIAS"
],
[
"Mølgaard",
"Esben",
"",
"CP3-Origins and DIAS"
],
[
"Sannino",
"Francesco",
"",
"CP3-Origins and DIAS"
]
] |
At high energy the standard model possesses conformal symmetry at the classical level. This is reflected at the quantum level by relations between the different beta functions of the model. These relations are known as the Weyl consistency conditions. We show that it is possible to satisfy them order by order in perturbation theory, provided that a suitable coupling constant counting scheme is used. As a direct phenomenological application, we study the stability of the standard model vacuum at high energies and compare with previous computations violating the Weyl consistency conditions.
|
1512.00232
|
Francesco Giacosa
|
Francesco Giacosa
|
Decay law and time dilatation
|
11 pages, 2 figures
| null |
10.5506/APhysPolB.47.2135
| null |
hep-ph quant-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study the decay law for a moving unstable particle. The usual
time-dilatation formula states that the decay width for an unstable state
moving with a momentum $p$ and mass $M$ is $\tilde{\Gamma}_{p}=\Gamma
M/\sqrt{p^{2}+M^{2}}$ with $\Gamma$ being the decay width in the rest frame. In
agreement with previous studies, we show that in the context of QM as well as
QFT this equation is \textit{not} correct provided that the quantum measurement
is performed in a reference frame in which the unstable particle has momentum
$p$ (note, a momentum eigenstate is \textit{not} a velocity eigenstate in QM).
We then give, to our knowledge for the first time, an analytic expression of an
improved formula and we show that the deviation from $\tilde{\Gamma}_{p}$ has a
maximum for $p/M=\sqrt{2/3},$ but is typically \textit{very} small. Then, the
result can be easily generalized to a momentum wave packet and also to an
arbitrary initial state. Here, we give a very general expression of the
non-decay probability. As a next step, we show that care is needed when one
makes a boost of an unstable state with zero momentum/velocity: namely, the
resulting state has zero overlap with the elements of the basis of unstable
states (it is already decayed!). However, when considering a spread in
velocity, one finds again that $\tilde{\Gamma }_{p}$ is typically a very good
approximation. The study of a velocity wave-packet represents an interesting
subject which constitutes one of the main outcomes of the present
manuscript.\textbf{ }In the end, it should be stressed that there is no
whatsoever breaking of special relativity, but as usual in QM, one should
specify which kind of measurement on which kind of state is performed.
|
[
{
"created": "Tue, 1 Dec 2015 11:44:30 GMT",
"version": "v1"
},
{
"created": "Mon, 11 Apr 2016 19:49:28 GMT",
"version": "v2"
},
{
"created": "Sat, 16 Apr 2016 18:17:46 GMT",
"version": "v3"
}
] |
2016-11-03
|
[
[
"Giacosa",
"Francesco",
""
]
] |
We study the decay law for a moving unstable particle. The usual time-dilatation formula states that the decay width for an unstable state moving with a momentum $p$ and mass $M$ is $\tilde{\Gamma}_{p}=\Gamma M/\sqrt{p^{2}+M^{2}}$ with $\Gamma$ being the decay width in the rest frame. In agreement with previous studies, we show that in the context of QM as well as QFT this equation is \textit{not} correct provided that the quantum measurement is performed in a reference frame in which the unstable particle has momentum $p$ (note, a momentum eigenstate is \textit{not} a velocity eigenstate in QM). We then give, to our knowledge for the first time, an analytic expression of an improved formula and we show that the deviation from $\tilde{\Gamma}_{p}$ has a maximum for $p/M=\sqrt{2/3},$ but is typically \textit{very} small. Then, the result can be easily generalized to a momentum wave packet and also to an arbitrary initial state. Here, we give a very general expression of the non-decay probability. As a next step, we show that care is needed when one makes a boost of an unstable state with zero momentum/velocity: namely, the resulting state has zero overlap with the elements of the basis of unstable states (it is already decayed!). However, when considering a spread in velocity, one finds again that $\tilde{\Gamma }_{p}$ is typically a very good approximation. The study of a velocity wave-packet represents an interesting subject which constitutes one of the main outcomes of the present manuscript.\textbf{ }In the end, it should be stressed that there is no whatsoever breaking of special relativity, but as usual in QM, one should specify which kind of measurement on which kind of state is performed.
|
2011.11949
|
Shi-Ping He
|
Shi-Ping He
|
Di-Higgs production as a probe of flavor changing neutral Yukawa
couplings
|
30 pages, 8 figures, and 5 tables. References added and typos
corrected. Comments are welcome
| null |
10.1088/1674-1137/abfb50
| null |
hep-ph hep-ex
|
http://creativecommons.org/licenses/by/4.0/
|
Top partners are well motivated in many new physics models. Usually, vector
like quarks $T_{L,R}$ are introduced to avoid the quantum anomaly. It is
crucial to probe their interactions with the standard model particles. However,
flavor changing neutral couplings are always difficult to detect directly in
the current and future experiments. In this paper, we will show how to
constrain the flavor changing neutral Yukawa coupling $Tth$ through the
di-Higgs production indirectly. We consider the simplified model including a
pair of gauge singlet $T_{L,R}$. Under the perturbative unitarity and
experimental constraints, we choose $m_T=400~\mathrm{GeV},s_L=0.2$ and
$m_T=800~\mathrm{GeV},s_L=0.1$ as benchmark points. After the analysis of
amplitude and evaluation of the numerical cross sections, we find that the
present constraints from di-Higgs production have already surpassed the
unitarity bound because of the $(y_{L,R}^{tT})^4$ behavior. For the case of
$m_T=400~\mathrm{GeV}$ and $s_L=0.2$, $\mathrm{Re}y_{L,R}^{tT}$ and
$\mathrm{Im}y_{L,R}^{tT}$ can be bounded optimally in the range $(-0.4, 0.4)$
at HL-LHC with $2\sigma$ CL. For the case of $m_T=800~\mathrm{GeV}$ and
$s_L=0.1$, $\mathrm{Re}y_{L,R}^{tT}$ and $\mathrm{Im}y_{L,R}^{tT}$ can be
bounded optimally in the range $(-0.5, 0.5)$ at HL-LHC with $2\sigma$ CL. The
anomalous triple Higgs coupling $\delta_{hhh}$ can also affect the constraints
on $y_{L,R}^{tT}$. Finally, we find that the top quark electric dipole moment
can give stronger bounds of $y_{L,R}^{tT}$ in the off-axis regions for some
scenarios.
|
[
{
"created": "Tue, 24 Nov 2020 08:05:42 GMT",
"version": "v1"
},
{
"created": "Sat, 5 Dec 2020 03:56:14 GMT",
"version": "v2"
}
] |
2021-09-01
|
[
[
"He",
"Shi-Ping",
""
]
] |
Top partners are well motivated in many new physics models. Usually, vector like quarks $T_{L,R}$ are introduced to avoid the quantum anomaly. It is crucial to probe their interactions with the standard model particles. However, flavor changing neutral couplings are always difficult to detect directly in the current and future experiments. In this paper, we will show how to constrain the flavor changing neutral Yukawa coupling $Tth$ through the di-Higgs production indirectly. We consider the simplified model including a pair of gauge singlet $T_{L,R}$. Under the perturbative unitarity and experimental constraints, we choose $m_T=400~\mathrm{GeV},s_L=0.2$ and $m_T=800~\mathrm{GeV},s_L=0.1$ as benchmark points. After the analysis of amplitude and evaluation of the numerical cross sections, we find that the present constraints from di-Higgs production have already surpassed the unitarity bound because of the $(y_{L,R}^{tT})^4$ behavior. For the case of $m_T=400~\mathrm{GeV}$ and $s_L=0.2$, $\mathrm{Re}y_{L,R}^{tT}$ and $\mathrm{Im}y_{L,R}^{tT}$ can be bounded optimally in the range $(-0.4, 0.4)$ at HL-LHC with $2\sigma$ CL. For the case of $m_T=800~\mathrm{GeV}$ and $s_L=0.1$, $\mathrm{Re}y_{L,R}^{tT}$ and $\mathrm{Im}y_{L,R}^{tT}$ can be bounded optimally in the range $(-0.5, 0.5)$ at HL-LHC with $2\sigma$ CL. The anomalous triple Higgs coupling $\delta_{hhh}$ can also affect the constraints on $y_{L,R}^{tT}$. Finally, we find that the top quark electric dipole moment can give stronger bounds of $y_{L,R}^{tT}$ in the off-axis regions for some scenarios.
|
0806.3166
|
Xiang-Song Chen
|
Xiang-Song Chen, Xiao-Fu L\"u, Wei-Min Sun, Fan Wang, and T. Goldman
|
Spin and orbital angular momentum in gauge theories: Nucleon spin
structure and multipole radiation revisited
|
4 pages, no figure
|
Phys.Rev.Lett.100:232002,2008
|
10.1103/PhysRevLett.100.232002
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We address and solve the long-standing gauge-invariance problem of the
nucleon spin structure. Explicitly gauge-invariant spin and orbital angular
momentum operators of quarks and gluons are obtained. This was previously
thought to be an impossible task, and opens a more promising avenue towards the
understanding of the nucleon spin. Our research also justifies the traditional
use of the canonical, gauge-dependent angular momentum operators of photons and
electrons in the multipole-radiation analysis and labeling of atomic states;
and sheds much light on the related energy-momentum problem in gauge theories,
especially in connection with the nucleon momentum.
|
[
{
"created": "Thu, 19 Jun 2008 09:53:47 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Chen",
"Xiang-Song",
""
],
[
"Lü",
"Xiao-Fu",
""
],
[
"Sun",
"Wei-Min",
""
],
[
"Wang",
"Fan",
""
],
[
"Goldman",
"T.",
""
]
] |
We address and solve the long-standing gauge-invariance problem of the nucleon spin structure. Explicitly gauge-invariant spin and orbital angular momentum operators of quarks and gluons are obtained. This was previously thought to be an impossible task, and opens a more promising avenue towards the understanding of the nucleon spin. Our research also justifies the traditional use of the canonical, gauge-dependent angular momentum operators of photons and electrons in the multipole-radiation analysis and labeling of atomic states; and sheds much light on the related energy-momentum problem in gauge theories, especially in connection with the nucleon momentum.
|
1109.3439
|
Orlando Oliveira
|
Orlando Oliveira, P. Bicudo, D. Dudal, T. Frederico, W. de Paula, N.
Vandersickel
|
From Running Gluon Mass to Chiral Symmetry Breaking
|
Talk at 11th Workshop on Non-Perturbative Quantum Chromodynamics,
Paris June 6-10, 2011. Two references added
| null | null | null |
hep-ph hep-lat
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The gluon propagator is one of the fundamental Green's functions of QCD. It
is an essential ingredient in, for example, the modeling of the Schwinger-Dyson
equation used to describe hadronic phenomenology. From the Landau gauge gluon
propagator, computed with lattice QCD methods, we discuss its interpretation as
a massive propagator and measure the gluon mass as a function of the momenta.
Special attention is given to the mass at infrared scales. In the last part of
the talk, the gluon mass and chiral symmetry breaking are related via an
effective model for QCD.
|
[
{
"created": "Thu, 15 Sep 2011 19:37:28 GMT",
"version": "v1"
},
{
"created": "Sat, 17 Sep 2011 20:50:33 GMT",
"version": "v2"
}
] |
2011-09-20
|
[
[
"Oliveira",
"Orlando",
""
],
[
"Bicudo",
"P.",
""
],
[
"Dudal",
"D.",
""
],
[
"Frederico",
"T.",
""
],
[
"de Paula",
"W.",
""
],
[
"Vandersickel",
"N.",
""
]
] |
The gluon propagator is one of the fundamental Green's functions of QCD. It is an essential ingredient in, for example, the modeling of the Schwinger-Dyson equation used to describe hadronic phenomenology. From the Landau gauge gluon propagator, computed with lattice QCD methods, we discuss its interpretation as a massive propagator and measure the gluon mass as a function of the momenta. Special attention is given to the mass at infrared scales. In the last part of the talk, the gluon mass and chiral symmetry breaking are related via an effective model for QCD.
|
hep-ph/0110317
|
Adam Falk
|
Adam F. Falk, Yuval Grossman, Zoltan Ligeti, Alexey A. Petrov
|
SU(3) Breaking and D0-D0bar Mixing
|
18 pages; minor corrections, version to appear in Phys. Rev. D
|
Phys.Rev.D65:054034,2002
|
10.1103/PhysRevD.65.054034
|
JHU-TIPAC-2001-04, LBNL-48969, WSU-HEP-0101
|
hep-ph
| null |
The main challenge in the Standard Model calculation of the mass and width
difference in the D0-D0bar system is to estimate the size of SU(3) breaking
effects. We prove that D meson mixing occurs in the Standard Model only at
second order in SU(3) violation. We consider the possibility that phase space
effects may be the dominant source of SU(3) breaking. We find that y=(Delta
Gamma)/(2Gamma) of the order of one percent is natural in the Standard Model,
potentially reducing the sensitivity to new physics of measurements of D meson
mixing.
|
[
{
"created": "Wed, 24 Oct 2001 20:14:43 GMT",
"version": "v1"
},
{
"created": "Wed, 14 Nov 2001 16:11:44 GMT",
"version": "v2"
}
] |
2014-11-17
|
[
[
"Falk",
"Adam F.",
""
],
[
"Grossman",
"Yuval",
""
],
[
"Ligeti",
"Zoltan",
""
],
[
"Petrov",
"Alexey A.",
""
]
] |
The main challenge in the Standard Model calculation of the mass and width difference in the D0-D0bar system is to estimate the size of SU(3) breaking effects. We prove that D meson mixing occurs in the Standard Model only at second order in SU(3) violation. We consider the possibility that phase space effects may be the dominant source of SU(3) breaking. We find that y=(Delta Gamma)/(2Gamma) of the order of one percent is natural in the Standard Model, potentially reducing the sensitivity to new physics of measurements of D meson mixing.
|
hep-ph/9710394
|
Christine Davies
|
C. T. H. Davies
|
The Heavy Hadron Spectrum
|
64 pages, Latex, lectures at Schladming Winter School 1997
| null |
10.1007/BFb0106892
| null |
hep-ph hep-lat
| null |
I discuss the spectrum of hadrons containing heavy quarks ($b$ or $c$), and
how well the experimental results are matched by theoretical ideas. Useful
insights come from potential models and applications of Heavy Quark Symmetry
and these can be compared with new numerical results from the ab initio methods
of Lattice QCD.
|
[
{
"created": "Fri, 17 Oct 1997 23:06:46 GMT",
"version": "v1"
}
] |
2009-10-30
|
[
[
"Davies",
"C. T. H.",
""
]
] |
I discuss the spectrum of hadrons containing heavy quarks ($b$ or $c$), and how well the experimental results are matched by theoretical ideas. Useful insights come from potential models and applications of Heavy Quark Symmetry and these can be compared with new numerical results from the ab initio methods of Lattice QCD.
|
0801.1425
|
Sergey Kiselev
|
S. M. Kiselev
|
Direct Photons in Nuclear Collisions at FAIR Energies
|
9 pages, 5 figures, Talk at the session of Russian Academy of
Sciences, ITEP, Moscow, 26 - 30 November 2007
| null |
10.1134/S1063778809030168
| null |
hep-ph
| null |
Using the extrapolation of existing data estimations of prompt photon
production at FAIR energies have been made. At $y=y_{c.m.}$ the rapidity
density of prompt photons with $p_{t}>$ 1.5 GeV/c per central Au+Au event at 25
AGeV is estimated as $\sim 10^{-4}$ . With the planed beam intensity $10^{9}$
per second and 1% interaction probability, for 10% of most central events one
can expect the prompt photon rate $\sim 10^{2}$ photons per second.
Direct photons from the hadron scenario of ion collisions generated by the
Hadron-String-Dynamics (HSD) transport approach with implemented meson
scatterings $\pi\rho\to\pi\gamma, \pi\pi\to\rho\gamma$ have been analyzed.
Photons from short-living resonances (e.g. $\omega \to \pi^{0} \gamma$)
decaying during the dense phase of the collision should be considered as direct
photons. They contribute significantly in the direct photon spectrum at
$p_{t}=0.5 - 1$ GeV/c. At the FAIR energy 25 AGeV in Au+Au central collisions
the HSD generator predicts, as a lower estimate,
$\gamma_{direct}/\gamma_{\pi^{0}} \simeq$ 0.5% in the region $p_{t}=0.5 - 1$
GeV/c. At $p_{t}=1.5 - 2$ GeV/c $\gamma_{prompt}/\gamma_{\pi^{0}} \simeq$ 2%.
Thermal direct photons have been evaluated with the Bjorken Hydro-Dynamics
(BHD) model. The BHD spectra differ strongly from the HSD predictions. The
direct photon spectrum is very sensitive to the initial temperature parameter
$T_{0}$ of the model. The 10 MeV increase in the $T_{0}$ value leads to $\sim$
2 times higher photon yield.
|
[
{
"created": "Wed, 9 Jan 2008 13:33:07 GMT",
"version": "v1"
}
] |
2009-11-13
|
[
[
"Kiselev",
"S. M.",
""
]
] |
Using the extrapolation of existing data estimations of prompt photon production at FAIR energies have been made. At $y=y_{c.m.}$ the rapidity density of prompt photons with $p_{t}>$ 1.5 GeV/c per central Au+Au event at 25 AGeV is estimated as $\sim 10^{-4}$ . With the planed beam intensity $10^{9}$ per second and 1% interaction probability, for 10% of most central events one can expect the prompt photon rate $\sim 10^{2}$ photons per second. Direct photons from the hadron scenario of ion collisions generated by the Hadron-String-Dynamics (HSD) transport approach with implemented meson scatterings $\pi\rho\to\pi\gamma, \pi\pi\to\rho\gamma$ have been analyzed. Photons from short-living resonances (e.g. $\omega \to \pi^{0} \gamma$) decaying during the dense phase of the collision should be considered as direct photons. They contribute significantly in the direct photon spectrum at $p_{t}=0.5 - 1$ GeV/c. At the FAIR energy 25 AGeV in Au+Au central collisions the HSD generator predicts, as a lower estimate, $\gamma_{direct}/\gamma_{\pi^{0}} \simeq$ 0.5% in the region $p_{t}=0.5 - 1$ GeV/c. At $p_{t}=1.5 - 2$ GeV/c $\gamma_{prompt}/\gamma_{\pi^{0}} \simeq$ 2%. Thermal direct photons have been evaluated with the Bjorken Hydro-Dynamics (BHD) model. The BHD spectra differ strongly from the HSD predictions. The direct photon spectrum is very sensitive to the initial temperature parameter $T_{0}$ of the model. The 10 MeV increase in the $T_{0}$ value leads to $\sim$ 2 times higher photon yield.
|
1202.4024
|
Pedro Miguel Martins Ferreira
|
P. M. Ferreira, L. Lavoura
|
Texture-zero model for the lepton mass matrices
|
10 pages, 3 figures; version for journal: new fit to data, new plots
| null |
10.1142/S0217732312501593
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We suggest a simple model, based on the type-I seesaw mechanism, for the
lepton mass matrices. The model hinges on an Abelian symmetry which leads to
mass matrices with some vanishing matrix elements. The model predicts one
massless neutrino and $M_{e\mu} = 0$ ($M$ is the effective light-neutrino
Majorana mass matrix). We show that these predictions perfectly agree with the
present experimental data if the neutrino mass spectrum is inverted, i.e. if
$m_3 = 0$, provided the Dirac phase $\delta$ is very close to maximal ($\pm \pi
/ 2$). In the case of a normal neutrino mass spectrum, i.e. when $m_1 = 0$, the
agreement of our model with the data is less than optimal---the reactor mixing
angle $\theta_{13}$ is too small in our model. Minimal leptogenesis is not an
option in our model due to the vanishing elements in the Yukawa-coupling
matrices.
|
[
{
"created": "Fri, 17 Feb 2012 21:07:12 GMT",
"version": "v1"
},
{
"created": "Mon, 27 Feb 2012 17:10:04 GMT",
"version": "v2"
},
{
"created": "Thu, 1 Mar 2012 16:46:30 GMT",
"version": "v3"
},
{
"created": "Mon, 1 Oct 2012 14:35:50 GMT",
"version": "v4"
}
] |
2015-06-04
|
[
[
"Ferreira",
"P. M.",
""
],
[
"Lavoura",
"L.",
""
]
] |
We suggest a simple model, based on the type-I seesaw mechanism, for the lepton mass matrices. The model hinges on an Abelian symmetry which leads to mass matrices with some vanishing matrix elements. The model predicts one massless neutrino and $M_{e\mu} = 0$ ($M$ is the effective light-neutrino Majorana mass matrix). We show that these predictions perfectly agree with the present experimental data if the neutrino mass spectrum is inverted, i.e. if $m_3 = 0$, provided the Dirac phase $\delta$ is very close to maximal ($\pm \pi / 2$). In the case of a normal neutrino mass spectrum, i.e. when $m_1 = 0$, the agreement of our model with the data is less than optimal---the reactor mixing angle $\theta_{13}$ is too small in our model. Minimal leptogenesis is not an option in our model due to the vanishing elements in the Yukawa-coupling matrices.
|
hep-ph/0610158
|
Walter Grimus
|
W. Grimus
|
Realizations of mu-tau interchange symmetry
|
4 pages, talk presented at ICHEP06, Moscow, July 26 - August 2, 2006
| null | null |
UWThPh-2006-25
|
hep-ph
| null |
Some models for the lepton sector, based on seesaw extensions of the Standard
Model, are discussed in which the mu-tau interchange symmetry is realized in
various ways. The symmetries defining such models and their characteristic
predictions for lepton mixing are presented.
|
[
{
"created": "Fri, 13 Oct 2006 07:00:03 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Grimus",
"W.",
""
]
] |
Some models for the lepton sector, based on seesaw extensions of the Standard Model, are discussed in which the mu-tau interchange symmetry is realized in various ways. The symmetries defining such models and their characteristic predictions for lepton mixing are presented.
|
1309.4892
|
Yohei Saito
|
Yohei Saito, Hirotsugu Fujii, Kazunori Itakura and Osamu Morimatsu
|
Microscopic identification of dissipative modes in relativistic field
theories
|
16 pages, 11 figures
| null |
10.1093/ptep/ptv065
| null |
hep-ph cond-mat.stat-mech
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We present an argument to support the existence of dissipative modes in
relativistic field theories. In an O(N) $\varphi^4$ theory in spatial dimension
$d\le 3$, a relaxation constant $\Gamma$ of a two-point function in an infrared
region is shown to be finite within the two-particle irreducible (2PI)
framework at the next-leading order (NLO) of 1/N expansion. This immediately
implies that a slow dissipative mode with a dispersion $p_0\sim i\Gamma \p^2$
is microscopically identified in the two-point function. Contrary, NLO
calculation in the one-particle irreducible (1PI) framework fails to yield a
finite relaxation constant. Comparing the results in 1PI and 2PI frameworks,
one concludes that dissipation emerges from multiple scattering of a particle
with a heat bath, which is appropriately treated in the 2PI-NLO calculation
through the resummation of secular terms to improve long-time behavior of the
two-point function. Assuming that this slow dissipative mode survives at the
critical point, one can identify the dynamic critical exponent $z$ for the
two-point function as $z=2-\eta$. We also discuss possible improvement of the
result.
|
[
{
"created": "Thu, 19 Sep 2013 08:53:30 GMT",
"version": "v1"
}
] |
2015-05-27
|
[
[
"Saito",
"Yohei",
""
],
[
"Fujii",
"Hirotsugu",
""
],
[
"Itakura",
"Kazunori",
""
],
[
"Morimatsu",
"Osamu",
""
]
] |
We present an argument to support the existence of dissipative modes in relativistic field theories. In an O(N) $\varphi^4$ theory in spatial dimension $d\le 3$, a relaxation constant $\Gamma$ of a two-point function in an infrared region is shown to be finite within the two-particle irreducible (2PI) framework at the next-leading order (NLO) of 1/N expansion. This immediately implies that a slow dissipative mode with a dispersion $p_0\sim i\Gamma \p^2$ is microscopically identified in the two-point function. Contrary, NLO calculation in the one-particle irreducible (1PI) framework fails to yield a finite relaxation constant. Comparing the results in 1PI and 2PI frameworks, one concludes that dissipation emerges from multiple scattering of a particle with a heat bath, which is appropriately treated in the 2PI-NLO calculation through the resummation of secular terms to improve long-time behavior of the two-point function. Assuming that this slow dissipative mode survives at the critical point, one can identify the dynamic critical exponent $z$ for the two-point function as $z=2-\eta$. We also discuss possible improvement of the result.
|
1110.2463
|
Tim Morris
|
Tim R. Morris
|
Superluminal group velocity through near-maximal neutrino oscillations
|
Reworking includes corrections due to finite width of the wave
packet, further references, and comments on other corrections, causality, the
new OPERA results, and why the size of neutrino wave packet provides
important constraints
|
J. Phys. G: Nucl. Part. Phys. 39 (2012) 045010
|
10.1088/0954-3899/39/4/045010
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Recently it was suggested that the observation of superluminal neutrinos by
the OPERA collaboration may be due to group velocity effects resulting from
close-to-maximal oscillation between neutrino mass eigenstates, in analogy to
known effects in optics. We show that superluminal propagation does occur
through this effect for a series of very narrow energy ranges, but this
phenomenum cannot explain the OPERA measurement.
|
[
{
"created": "Tue, 11 Oct 2011 18:51:14 GMT",
"version": "v1"
},
{
"created": "Wed, 12 Oct 2011 20:01:23 GMT",
"version": "v2"
},
{
"created": "Thu, 15 Dec 2011 18:58:25 GMT",
"version": "v3"
}
] |
2012-03-20
|
[
[
"Morris",
"Tim R.",
""
]
] |
Recently it was suggested that the observation of superluminal neutrinos by the OPERA collaboration may be due to group velocity effects resulting from close-to-maximal oscillation between neutrino mass eigenstates, in analogy to known effects in optics. We show that superluminal propagation does occur through this effect for a series of very narrow energy ranges, but this phenomenum cannot explain the OPERA measurement.
|
hep-ph/0510167
|
Yukio Nemoto
|
Masakiyo Kitazawa, Teiji Kunihiro, Yukio Nemoto
|
Quark Spectrum above but near Critical Temperature of Chiral Transition
|
6 pages, 12 eps figures, typos corrected and references updated,
version to appear in Phys. Lett. B
|
Phys.Lett. B633 (2006) 269-274
|
10.1016/j.physletb.2005.11.076
| null |
hep-ph nucl-th
| null |
We explore the quark properties at finite temperature near but above the
critical temperature of the chiral phase transition. We investigate the effects
of the precursory soft mode of the phase transition on the quark dispersion
relation and the spectral function. It is found that there appear novel
excitation spectra of quasi-quarks and quasi-antiquarks with a three-peak
structure, which are not attributed to the hard-thermal-loop approximation. We
show that the new spectra originate from the mixing between a quark
(anti-quark) and an anti-quark hole (quark hole) caused by a ``resonant
scattering'' of the quasi-fermions with the thermally-excited soft mode which
has a small but finite excitation energy.
|
[
{
"created": "Thu, 13 Oct 2005 01:15:02 GMT",
"version": "v1"
},
{
"created": "Fri, 9 Dec 2005 13:41:25 GMT",
"version": "v2"
}
] |
2009-11-11
|
[
[
"Kitazawa",
"Masakiyo",
""
],
[
"Kunihiro",
"Teiji",
""
],
[
"Nemoto",
"Yukio",
""
]
] |
We explore the quark properties at finite temperature near but above the critical temperature of the chiral phase transition. We investigate the effects of the precursory soft mode of the phase transition on the quark dispersion relation and the spectral function. It is found that there appear novel excitation spectra of quasi-quarks and quasi-antiquarks with a three-peak structure, which are not attributed to the hard-thermal-loop approximation. We show that the new spectra originate from the mixing between a quark (anti-quark) and an anti-quark hole (quark hole) caused by a ``resonant scattering'' of the quasi-fermions with the thermally-excited soft mode which has a small but finite excitation energy.
|
0807.4199
|
Jennifer Kile
|
Jennifer Kile, Amarjit Soni
|
Model-Independent Constraints on Lepton-Flavor-Violating Decays of the
Top Quark
|
15 pages, 5 figures; v2: slightly revised references, small changes
in wording, two results expanded to include 2nd lepton flavor case
|
Phys.Rev.D78:094008,2008
|
10.1103/PhysRevD.78.094008
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The imminent start of the Large Hadron Collider, which is expected to produce
$\sim 10^8$ $t\bar{t}$ pairs per year, provides an unprecedented opportunity
for top physics. As the top quark is widely expected to be rather sensitive to
effects of new physics, a detailed study of its properties, including rare
decays, is called for. A possible, experimentally distinctive decay is the case
where a top decays to a light quark and a flavor-violating lepton-antilepton
pair. We use an effective operator analysis to place model-independent bounds
on contributions to the decays $t\to u e^{\pm} \mu^{\mp}$ and $t\to c e^{\pm}
\mu^{\mp}$. We enumerate the dimension-six operators which contribute to these
decays and which are invariant under the Standard Model gauge group. We
separate these operators into two classes, one with operators where the top
quark belongs to an SU(2) doublet and thus can contribute at tree level to
low-energy processes, and one class with operators where the top quark is a
right-handed singlet and can only contribute to low-energy processes via loop
diagrams. We use $B$ and $K$ decays to place limits on the coefficients of some
of these operators, but find that several remain unconstrained and could
potentially make observable contributions to top decay.
|
[
{
"created": "Fri, 25 Jul 2008 22:52:39 GMT",
"version": "v1"
},
{
"created": "Thu, 21 Aug 2008 21:14:23 GMT",
"version": "v2"
}
] |
2010-05-12
|
[
[
"Kile",
"Jennifer",
""
],
[
"Soni",
"Amarjit",
""
]
] |
The imminent start of the Large Hadron Collider, which is expected to produce $\sim 10^8$ $t\bar{t}$ pairs per year, provides an unprecedented opportunity for top physics. As the top quark is widely expected to be rather sensitive to effects of new physics, a detailed study of its properties, including rare decays, is called for. A possible, experimentally distinctive decay is the case where a top decays to a light quark and a flavor-violating lepton-antilepton pair. We use an effective operator analysis to place model-independent bounds on contributions to the decays $t\to u e^{\pm} \mu^{\mp}$ and $t\to c e^{\pm} \mu^{\mp}$. We enumerate the dimension-six operators which contribute to these decays and which are invariant under the Standard Model gauge group. We separate these operators into two classes, one with operators where the top quark belongs to an SU(2) doublet and thus can contribute at tree level to low-energy processes, and one class with operators where the top quark is a right-handed singlet and can only contribute to low-energy processes via loop diagrams. We use $B$ and $K$ decays to place limits on the coefficients of some of these operators, but find that several remain unconstrained and could potentially make observable contributions to top decay.
|
hep-ph/9907223
|
Edi Halyo
|
Edi Halyo
|
Late D-term Inflation and the Cosmological Moduli Problem in TeV Scale
Strings
|
12 pages in phyzzx.tex, one reference added
|
JHEP 9909:012,1999
|
10.1088/1126-6708/1999/09/012
| null |
hep-ph
| null |
We show that a short period of late D-term inflation can solve the
cosmological moduli (radion) problem of (asymmetric) inflation at the TeV
scale. Late inflation happens after the large compact dimensions are stabilized
which is crucial for obtaining the extremely small Hubble constant and inflaton
mass required.
|
[
{
"created": "Mon, 5 Jul 1999 02:35:47 GMT",
"version": "v1"
},
{
"created": "Tue, 27 Jul 1999 22:00:44 GMT",
"version": "v2"
}
] |
2010-02-03
|
[
[
"Halyo",
"Edi",
""
]
] |
We show that a short period of late D-term inflation can solve the cosmological moduli (radion) problem of (asymmetric) inflation at the TeV scale. Late inflation happens after the large compact dimensions are stabilized which is crucial for obtaining the extremely small Hubble constant and inflaton mass required.
|
0908.0240
|
Emiliano Molinaro
|
C. Hagedorn, E. Molinaro, S.T. Petcov
|
Majorana Phases and Leptogenesis in See-Saw Models with A_4 Symmetry
|
matches published version
|
JHEP 0909:115,2009
|
10.1088/1126-6708/2009/09/115
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The related issues of Majorana CP violation in the lepton sector and
leptogenesis are investigated in detail in two rather generic supersymmetric
models with type I see-saw mechanism of neutrino mass generation and A_4
flavour symmetry, which naturally lead at leading order to tri-bimaximal
neutrino mixing. The neutrino sector in this class of models is described at
leading order by just two real parameters and one phase. This leads, in
particular, to significant low energy constraints on the Majorana phases
\alpha_{21} and \alpha_{31} in the PMNS matrix, which play the role of
leptogenesis CP violating parameters in the generation of the baryon asymmetry
of the Universe. We find that it is possible to generate the correct size and
sign of the baryon asymmetry in both A_4 models. The sign of the baryon
asymmetry is directly related to the signs of sin\alpha_{21} and/or
sin\alpha_{31}.
|
[
{
"created": "Mon, 3 Aug 2009 13:27:21 GMT",
"version": "v1"
},
{
"created": "Mon, 28 Sep 2009 14:31:34 GMT",
"version": "v2"
}
] |
2010-01-08
|
[
[
"Hagedorn",
"C.",
""
],
[
"Molinaro",
"E.",
""
],
[
"Petcov",
"S. T.",
""
]
] |
The related issues of Majorana CP violation in the lepton sector and leptogenesis are investigated in detail in two rather generic supersymmetric models with type I see-saw mechanism of neutrino mass generation and A_4 flavour symmetry, which naturally lead at leading order to tri-bimaximal neutrino mixing. The neutrino sector in this class of models is described at leading order by just two real parameters and one phase. This leads, in particular, to significant low energy constraints on the Majorana phases \alpha_{21} and \alpha_{31} in the PMNS matrix, which play the role of leptogenesis CP violating parameters in the generation of the baryon asymmetry of the Universe. We find that it is possible to generate the correct size and sign of the baryon asymmetry in both A_4 models. The sign of the baryon asymmetry is directly related to the signs of sin\alpha_{21} and/or sin\alpha_{31}.
|
1901.11238
|
Oleg Boyarkin
|
O.M.Boyarkin, G.G.Boyarkina, D.S.Vasileuskaya
|
Neutrino mixings as a source of lepton flavor violations
|
12 pages, 1 figures
|
Int. J. Mod. Phys. A, 2018.- Vol. 33. P. 1850201-1850214
|
10.1142/S0217751X18502019
| null |
hep-ph
|
http://creativecommons.org/licenses/by-sa/4.0/
|
Within the left-right symmetric model (LRM) the $Z$ boson decay into the
channel $Z\to\tau\mu$ are investigated. The branching ratios of this decay is
found in the third order of the perturbation theory. The obtained expression
does not equal to zero only at the existence of the neutrino mixings. It means
that from the point of view of the LRM nonconservation both of neutral and of
charged lepton flavors has the same nature. As a result, elucidation of the
decays $Z\to\l_i\overline{l}_k$ ($i\neq k$) could provide data concerned the
neutrino sector structure of the LRM. The neutrino sector parameters which
could be measured in that case are as follows: (i) difference of the heavy
neutrino masses; (ii) heavy-heavy neutrino mixing; (iii) heavy-light neutrino
mixing.
|
[
{
"created": "Thu, 31 Jan 2019 07:04:28 GMT",
"version": "v1"
}
] |
2019-02-06
|
[
[
"Boyarkin",
"O. M.",
""
],
[
"Boyarkina",
"G. G.",
""
],
[
"Vasileuskaya",
"D. S.",
""
]
] |
Within the left-right symmetric model (LRM) the $Z$ boson decay into the channel $Z\to\tau\mu$ are investigated. The branching ratios of this decay is found in the third order of the perturbation theory. The obtained expression does not equal to zero only at the existence of the neutrino mixings. It means that from the point of view of the LRM nonconservation both of neutral and of charged lepton flavors has the same nature. As a result, elucidation of the decays $Z\to\l_i\overline{l}_k$ ($i\neq k$) could provide data concerned the neutrino sector structure of the LRM. The neutrino sector parameters which could be measured in that case are as follows: (i) difference of the heavy neutrino masses; (ii) heavy-heavy neutrino mixing; (iii) heavy-light neutrino mixing.
|
hep-ph/9911426
|
Pierre Marage
|
P. Marage
|
Hadronic structure, low x physics and diffraction
|
Plenary report presented at the Int. Europhys. Conf. on HEP,
EPS-HEP99, Tampere, Finland, July 1999; 21 pages, 45 figures, 110 references
| null | null | null |
hep-ph
| null |
A review is presented of numerous recent results, particularly those
submitted to the EPS-HEP99 conference: very high Q^2 ep interactions and direct
tests of the Standard Model, new measurements of the structure of the proton
(including high x parton distributions and tests of QCD involving the gluon
distribution), low x physics (tests of the BFKL evolution), diffraction in DIS
at HERA, hard diffraction at the Tevatron and exclusive production of vector
particles at HERA. The focus is on hard QCD features.
|
[
{
"created": "Sun, 21 Nov 1999 18:01:35 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Marage",
"P.",
""
]
] |
A review is presented of numerous recent results, particularly those submitted to the EPS-HEP99 conference: very high Q^2 ep interactions and direct tests of the Standard Model, new measurements of the structure of the proton (including high x parton distributions and tests of QCD involving the gluon distribution), low x physics (tests of the BFKL evolution), diffraction in DIS at HERA, hard diffraction at the Tevatron and exclusive production of vector particles at HERA. The focus is on hard QCD features.
|
2204.01741
|
Seth Koren
|
Seth Koren
|
A Note on Proton Stability in the Standard Model
|
Three pages. I suspect this is known to some experts, but I think
such an important result deserves to have an accessible explanation available
and to be more widely-known. v2: Minor text edits to match published version
|
Universe 2022, 8(6), 308
|
10.3390/universe8060308
| null |
hep-ph hep-th
|
http://creativecommons.org/licenses/by/4.0/
|
In this short note we describe the symmetry responsible for absolute,
nonperturbative proton stability in the Standard Model. The SM with $N_c$
colors and ${N_g}$ generations has an exact, anomaly-free,
generation-independent, global symmetry group $U(1)_{B-N_c L} \times
\mathbb{Z}_{N_g}^L$, which contains a subgroup of baryon plus lepton number of
order $2 N_c {N_g}$. This disallows proton decay for ${N_g}>1$. Many
well-studied models beyond the SM explicitly break this global symmetry, and
the alternative deserves further attention.
|
[
{
"created": "Mon, 4 Apr 2022 18:00:00 GMT",
"version": "v1"
},
{
"created": "Mon, 11 Jul 2022 20:09:45 GMT",
"version": "v2"
}
] |
2022-07-13
|
[
[
"Koren",
"Seth",
""
]
] |
In this short note we describe the symmetry responsible for absolute, nonperturbative proton stability in the Standard Model. The SM with $N_c$ colors and ${N_g}$ generations has an exact, anomaly-free, generation-independent, global symmetry group $U(1)_{B-N_c L} \times \mathbb{Z}_{N_g}^L$, which contains a subgroup of baryon plus lepton number of order $2 N_c {N_g}$. This disallows proton decay for ${N_g}>1$. Many well-studied models beyond the SM explicitly break this global symmetry, and the alternative deserves further attention.
|
hep-ph/0303073
|
Igor Shovkovy
|
Igor A. Shovkovy and Paul J. Ellis
|
Impact of CFL Quark Matter on the Cooling of Compact Stars
|
7 pages. Talk presented at 2002 International Workshop "On Strong
Coupling Gauge Theories And Effective Field Theories" (SCGT 02), 10-13
December 2002, Nagoya, Japan
| null |
10.1142/9789812795120_0019
| null |
hep-ph astro-ph hep-th nucl-th
| null |
The cooling mechanism of compact stars with quark cores in the color-flavor
locked phase is discussed. It is argued that the high thermal conductivity of
the quark core plays a key role in the stellar cooling. It implies that the
cooling time of compact stars with color-flavor locked quark cores is similar
to that of ordinary neutron stars, unless the star is almost completely made of
color-flavor locked quark matter.
|
[
{
"created": "Mon, 10 Mar 2003 17:17:21 GMT",
"version": "v1"
}
] |
2017-08-23
|
[
[
"Shovkovy",
"Igor A.",
""
],
[
"Ellis",
"Paul J.",
""
]
] |
The cooling mechanism of compact stars with quark cores in the color-flavor locked phase is discussed. It is argued that the high thermal conductivity of the quark core plays a key role in the stellar cooling. It implies that the cooling time of compact stars with color-flavor locked quark cores is similar to that of ordinary neutron stars, unless the star is almost completely made of color-flavor locked quark matter.
|
2103.08507
|
Feng Feng
|
Feng Feng, Yi-Fan Xie, Qiu-Chen Zhou, Shan-Rong Tang
|
HepLib: A C++ Library for High Energy Physics
|
26 pages, 1 figure
| null |
10.1016/j.cpc.2021.107982
| null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
HepLib is a C++ Library for computations in High Energy Physics, it works on
top of GiNaC, a well-established C++ library used to perform symbolic
computations. HepLib combines serval well-known packages to get high
efficiency, including Qgraf to generate Feynman aptitudes, FORM to perform
Dirac/Color matrix related computations, and FIRE or KIRA for
integration-by-parts (IBP) reduction. Another core feature of HepLib lies in
the numerical evaluation of master integrals using sector decomposition, which
is a general method widely used in high-order numerical computation and has
been implemented in many public packages in many different languages, and we
present another implementation in the language of C++ with many new features.
We use GiNaC to handle the symbolic operations, and export the corresponding
integrand into an optimized C++ code, that will be compiled internally and
linked dynamically, a customizable numerical integrator is selected to perform
the numerical integration, while the integrand can be evaluated in different
float precisions, including the arbitrary precision supported by MPFR.
|
[
{
"created": "Mon, 15 Mar 2021 16:27:44 GMT",
"version": "v1"
}
] |
2021-05-19
|
[
[
"Feng",
"Feng",
""
],
[
"Xie",
"Yi-Fan",
""
],
[
"Zhou",
"Qiu-Chen",
""
],
[
"Tang",
"Shan-Rong",
""
]
] |
HepLib is a C++ Library for computations in High Energy Physics, it works on top of GiNaC, a well-established C++ library used to perform symbolic computations. HepLib combines serval well-known packages to get high efficiency, including Qgraf to generate Feynman aptitudes, FORM to perform Dirac/Color matrix related computations, and FIRE or KIRA for integration-by-parts (IBP) reduction. Another core feature of HepLib lies in the numerical evaluation of master integrals using sector decomposition, which is a general method widely used in high-order numerical computation and has been implemented in many public packages in many different languages, and we present another implementation in the language of C++ with many new features. We use GiNaC to handle the symbolic operations, and export the corresponding integrand into an optimized C++ code, that will be compiled internally and linked dynamically, a customizable numerical integrator is selected to perform the numerical integration, while the integrand can be evaluated in different float precisions, including the arbitrary precision supported by MPFR.
|
1603.03568
|
Takumi Kuwahara
|
Borut Bajc, Junji Hisano, Takumi Kuwahara and Yuji Omura
|
Threshold Corrections to Dimension-six Proton Decay Operators in
Non-minimal SUSY SU(5) GUTs
|
26 pages, 3 figures. Version accepted for publication in Nuclear
Physics B (typos and numerical errors are corrected, and texts are added)
| null |
10.1016/j.nuclphysb.2016.06.017
|
IPMU16-0026
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We calculate the high and low scale threshold corrections to the D=6 proton
decay mode in supersymmetric SU(5) grand unified theories with
higher-dimensional representation Higgs multiplets. In particular, we focus on
a missing-partner model in which the grand unified group is spontaneously
broken by the 75-dimensional Higgs multiplet and the doublet-triplet splitting
problem is solved. We find that in the missing-partner model the D=6 proton
decay rate gets suppressed by about 60%, mainly due to the threshold effect at
the GUT scale, while the SUSY-scale threshold corrections are found to be less
prominent when sfermions are heavy.
|
[
{
"created": "Fri, 11 Mar 2016 09:06:55 GMT",
"version": "v1"
},
{
"created": "Wed, 13 Jul 2016 03:29:58 GMT",
"version": "v2"
}
] |
2016-07-14
|
[
[
"Bajc",
"Borut",
""
],
[
"Hisano",
"Junji",
""
],
[
"Kuwahara",
"Takumi",
""
],
[
"Omura",
"Yuji",
""
]
] |
We calculate the high and low scale threshold corrections to the D=6 proton decay mode in supersymmetric SU(5) grand unified theories with higher-dimensional representation Higgs multiplets. In particular, we focus on a missing-partner model in which the grand unified group is spontaneously broken by the 75-dimensional Higgs multiplet and the doublet-triplet splitting problem is solved. We find that in the missing-partner model the D=6 proton decay rate gets suppressed by about 60%, mainly due to the threshold effect at the GUT scale, while the SUSY-scale threshold corrections are found to be less prominent when sfermions are heavy.
|
hep-ph/0012044
|
Carlo Giunti
|
M.V. Garzelli, C. Giunti
|
A frequentist analysis of solar neutrino data
|
4 pages. Talk presented by M.V. Garzelli at the EuroConference on
"Frontiers in Particle Astrophysics and Cosmology", San Feliu de Guixols,
Spain, 30 Sep. - 5 Oct. 2000
|
Nucl.Phys.Proc.Suppl. 95 (2001) 146-149
|
10.1016/S0920-5632(01)01071-4
|
DFTT 45/00
|
hep-ph
| null |
We present a Monte Carlo analysis in terms of neutrino oscillations of the
total rates measured in solar neutrino experiments in the framework of
frequentist statistics. We show that the goodness of fit and the confidence
level of the allowed regions in the space of the neutrino oscillation
parameters are significantly overestimated in the standard method. We also
present a calculation of exact allowed regions with correct frequentist
coverage. We show that the exact VO, LMA and LOW regions are much larger than
the standard ones and merge together giving an allowed band at large mixing
angles for all Delta m^2 > 10^{-10} eV^2.
|
[
{
"created": "Tue, 5 Dec 2000 10:06:32 GMT",
"version": "v1"
}
] |
2009-10-31
|
[
[
"Garzelli",
"M. V.",
""
],
[
"Giunti",
"C.",
""
]
] |
We present a Monte Carlo analysis in terms of neutrino oscillations of the total rates measured in solar neutrino experiments in the framework of frequentist statistics. We show that the goodness of fit and the confidence level of the allowed regions in the space of the neutrino oscillation parameters are significantly overestimated in the standard method. We also present a calculation of exact allowed regions with correct frequentist coverage. We show that the exact VO, LMA and LOW regions are much larger than the standard ones and merge together giving an allowed band at large mixing angles for all Delta m^2 > 10^{-10} eV^2.
|
1704.04708
|
Kang Xian-Wei
|
I. I. Bigi, Xian-Wei Kang, and Hai-Bo Li
|
CP Asymmetries in Strange Baryon Decays
|
final version, slight typos corrected
|
Chin. Phys. C42 (2018) no.1, 013101
|
10.1088/1674-1137/42/1/013101
|
UND-HEP-17-BIG; IHEP-BESIII-LI01
|
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
While indirect & direct CP violations (CPV) had been established in the
decays of strange & beauty mesons, none have been done for baryons. There are
different "roads" for finding CP asymmetries in the decays of strange baryons;
they are highly non-trivial ones. The HyperCP Collaboration had probed CPV in
the decays of single $\Xi$ & $\Lambda$ [Phys.Rev.Lett 93 (2004) 262001]. We
talk about future lessons from $e^+e^-$ collisions at BESIII/BEPCII: probing
decays of pairs of strange baryons, namely $\Lambda$, $\Sigma$ & $\Xi$.
Realistic goals are to learn about non-perturbative QCD. One can hope to find
CPV in the decays of strange baryons; one can also dream to find impact of New
Dynamics (ND). We point out that a new important era starts with the
BESIII/BEPCII data accumulated by the end of 2018.
|
[
{
"created": "Sun, 16 Apr 2017 01:41:44 GMT",
"version": "v1"
},
{
"created": "Sat, 22 Apr 2017 03:07:45 GMT",
"version": "v2"
},
{
"created": "Thu, 19 Oct 2017 03:01:41 GMT",
"version": "v3"
},
{
"created": "Wed, 22 Nov 2017 13:57:41 GMT",
"version": "v4"
}
] |
2017-11-23
|
[
[
"Bigi",
"I. I.",
""
],
[
"Kang",
"Xian-Wei",
""
],
[
"Li",
"Hai-Bo",
""
]
] |
While indirect & direct CP violations (CPV) had been established in the decays of strange & beauty mesons, none have been done for baryons. There are different "roads" for finding CP asymmetries in the decays of strange baryons; they are highly non-trivial ones. The HyperCP Collaboration had probed CPV in the decays of single $\Xi$ & $\Lambda$ [Phys.Rev.Lett 93 (2004) 262001]. We talk about future lessons from $e^+e^-$ collisions at BESIII/BEPCII: probing decays of pairs of strange baryons, namely $\Lambda$, $\Sigma$ & $\Xi$. Realistic goals are to learn about non-perturbative QCD. One can hope to find CPV in the decays of strange baryons; one can also dream to find impact of New Dynamics (ND). We point out that a new important era starts with the BESIII/BEPCII data accumulated by the end of 2018.
|
hep-ph/0104097
|
Dima Kuzmenko
|
A.M.Badalian, D.S.Kuzmenko (ITEP, Moscow)
|
Freezing of QCD coupling affects the short distance static potential
|
LaTeX2e, 17 pages, 6 PostScript figures, 1 GIF figure, final version
to appear in Phys. Rev. D
|
Phys.Rev. D65 (2002) 016004
|
10.1103/PhysRevD.65.016004
| null |
hep-ph hep-lat
| null |
A striking contradiction between lattice short range static potential (nf=0)
and standard perturbative potential, observed by Bali G.S., is investigated in
the framework of the background perturbation theory. With the use of the
background coupling which contains the only background parameter - mass mB,
fixed by fine structure fit in bottomonium, the lattice data are nicely
explained without introduction of exotic short range linear potential with
large "string tension" approx. 1 GeV squared. A significant difference between
the background coupling and standard perturbative coupling is found in the
range 0.05 fm < r<0.15 fm, while at larger distances, r > 0.3 fm the background
coupling fast approaches the freezing value. Some problems concerning the
strong coupling properties at short and long distances are discussed and
solutions are suggested.
|
[
{
"created": "Tue, 10 Apr 2001 14:49:24 GMT",
"version": "v1"
},
{
"created": "Tue, 29 May 2001 10:57:14 GMT",
"version": "v2"
},
{
"created": "Thu, 31 May 2001 14:31:00 GMT",
"version": "v3"
},
{
"created": "Wed, 12 Sep 2001 12:50:31 GMT",
"version": "v4"
},
{
"created": "Mon, 5 Nov 2001 08:15:23 GMT",
"version": "v5"
}
] |
2009-11-07
|
[
[
"Badalian",
"A. M.",
"",
"ITEP, Moscow"
],
[
"Kuzmenko",
"D. S.",
"",
"ITEP, Moscow"
]
] |
A striking contradiction between lattice short range static potential (nf=0) and standard perturbative potential, observed by Bali G.S., is investigated in the framework of the background perturbation theory. With the use of the background coupling which contains the only background parameter - mass mB, fixed by fine structure fit in bottomonium, the lattice data are nicely explained without introduction of exotic short range linear potential with large "string tension" approx. 1 GeV squared. A significant difference between the background coupling and standard perturbative coupling is found in the range 0.05 fm < r<0.15 fm, while at larger distances, r > 0.3 fm the background coupling fast approaches the freezing value. Some problems concerning the strong coupling properties at short and long distances are discussed and solutions are suggested.
|
0903.4760
|
Andrey Grozin
|
S. Bekavac, A. G. Grozin, D. Seidel, V. A. Smirnov
|
Three-loop on-shell Feynman integrals with two masses
|
22 pages; complete results as Mathematica files are available at
http://www-ttp.particle.uni-karlsruhe.de/Progdata/ttp09/ttp09-08/ v2: 2
references added, v3: Ref. [16] corrected
|
Nucl.Phys.B819:183-200,2009
|
10.1016/j.nuclphysb.2009.04.015
|
TTP09-08, SFB/CPP-09-29, Alberta Thy 05-09
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
All three-loop on-shell QCD Feynman integrals with two masses can be reduced
to 27 master integrals. Here we calculate these master integrals, expanded in
epsilon, both exactly in the mass ratio and as series in limiting cases.
|
[
{
"created": "Fri, 27 Mar 2009 10:23:14 GMT",
"version": "v1"
},
{
"created": "Mon, 30 Mar 2009 13:22:04 GMT",
"version": "v2"
},
{
"created": "Sun, 27 Dec 2009 14:51:42 GMT",
"version": "v3"
}
] |
2009-12-27
|
[
[
"Bekavac",
"S.",
""
],
[
"Grozin",
"A. G.",
""
],
[
"Seidel",
"D.",
""
],
[
"Smirnov",
"V. A.",
""
]
] |
All three-loop on-shell QCD Feynman integrals with two masses can be reduced to 27 master integrals. Here we calculate these master integrals, expanded in epsilon, both exactly in the mass ratio and as series in limiting cases.
|
hep-ph/0505135
|
Rafael Montemayor
|
R. Montemayor and L.F. Urrutia
|
Synchrotron Radiation in Lorentz-violating Electrodynamics: the
Myers-Pospelov model
|
33 pages, 2 tables. A new brief section (Section VII) has been added
with a discussion of the contributions of dimension six operators, and the
Introduction has been enlarged with some comments about numerical values of
current bounds to LIV parameters and additional references
|
Phys.Rev. D72 (2005) 045018
|
10.1103/PhysRevD.72.045018
| null |
hep-ph
| null |
We develop a detailed analysis of synchrotron radiation in the effective
Lorentz invariance violating (LIV) model of Myers-Pospelov, considering
explicitly both the dynamics of the charge producing the radiation and the
dynamics of the electromagnetic field itself. Within the radiation
approximation we compute exact expressions in the LIV parameters for the
electric and magnetic fields, the angular distribution of the power spectrum,
the total emitted power in the m-th harmonic and the polarization. We also
perform expansions of the exact results in terms of the LIV parameters to
identify the dominant effects, and study the main features of the high energy
limit of the spectrum. A very interesting consequence is the appearance of
rather unexpected and large amplifying factors associated with the LIV effects,
which go along with the usual contributions of the expansion parameter. This
opens up the possibility of looking for astrophysical sources where these
amplifying factors are important to further explore the constraints imposed
upon the LIV parameters by synchrotron radiation measurements. We briefly
sketch some phenomenological applications in the case of SNRs and GRBs.
|
[
{
"created": "Mon, 16 May 2005 03:42:45 GMT",
"version": "v1"
},
{
"created": "Mon, 15 Aug 2005 19:57:34 GMT",
"version": "v2"
}
] |
2009-11-11
|
[
[
"Montemayor",
"R.",
""
],
[
"Urrutia",
"L. F.",
""
]
] |
We develop a detailed analysis of synchrotron radiation in the effective Lorentz invariance violating (LIV) model of Myers-Pospelov, considering explicitly both the dynamics of the charge producing the radiation and the dynamics of the electromagnetic field itself. Within the radiation approximation we compute exact expressions in the LIV parameters for the electric and magnetic fields, the angular distribution of the power spectrum, the total emitted power in the m-th harmonic and the polarization. We also perform expansions of the exact results in terms of the LIV parameters to identify the dominant effects, and study the main features of the high energy limit of the spectrum. A very interesting consequence is the appearance of rather unexpected and large amplifying factors associated with the LIV effects, which go along with the usual contributions of the expansion parameter. This opens up the possibility of looking for astrophysical sources where these amplifying factors are important to further explore the constraints imposed upon the LIV parameters by synchrotron radiation measurements. We briefly sketch some phenomenological applications in the case of SNRs and GRBs.
|
hep-ph/0308270
|
Athar Husain
|
H. Athar, Jie-Jun Tseng, Guey-Lin Lin
|
High energy tau neutrinos: production, propagation and prospects of
observations
|
4 pages, 2 figs, talk given at 28th International Cosmic Ray
Conference (ICRC 2003), Tsukuba, Japan, 31 July-7 Aug, 2003, appeared in its
proceedings edited by T. Kajita et al., HE, pp. 1431-1434
| null | null | null |
hep-ph astro-ph
| null |
High energy tau neutrinos with energy greater than several thousands of GeV
may be produced in some astrophysical sites. A summary of the intrinsic high
energy tau neutrino flux estimates from some representative astrophysical sites
is presented including the effects of neutrino flavor oscillations. The
presently envisaged prospects of observations of the oscillated high energy tau
neutrino flux are mentioned. In particular, a recently suggested possibility of
future observations of Earth-skimming high energy tau neutrinos is briefly
discussed.
|
[
{
"created": "Wed, 27 Aug 2003 04:57:23 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Athar",
"H.",
""
],
[
"Tseng",
"Jie-Jun",
""
],
[
"Lin",
"Guey-Lin",
""
]
] |
High energy tau neutrinos with energy greater than several thousands of GeV may be produced in some astrophysical sites. A summary of the intrinsic high energy tau neutrino flux estimates from some representative astrophysical sites is presented including the effects of neutrino flavor oscillations. The presently envisaged prospects of observations of the oscillated high energy tau neutrino flux are mentioned. In particular, a recently suggested possibility of future observations of Earth-skimming high energy tau neutrinos is briefly discussed.
|
hep-ph/0504254
|
S. M. Gerasyuta
|
S. M. Gerasyuta, V. I. Kochkin
|
Relativistic five-quark equations and negative parity pentaquarks
|
18 pages, pdf, published version
|
Phys.Rev. D72 (2005) 016002
|
10.1103/PhysRevD.72.016002
| null |
hep-ph
| null |
The relativistic five-quark equations are found in the framework of the
dispersion relation technique. The solutions of these equations using the
method based on the extraction of the leading singularities of the amplitudes
are obtained. The five-quark amplitudes for the low-lying pentaquarks including
the u, d, s- quarks are calculated. The poles of these amplitudes determine the
masses of the negative parity pentaquarks with I = 0, 1 and spin 3/2-, 5/2-.
The mass of the lowest pentaquark with I = 0 and spin 3/2- is equal to 1514
MeV.
|
[
{
"created": "Wed, 27 Apr 2005 09:08:31 GMT",
"version": "v1"
},
{
"created": "Sat, 29 Oct 2005 07:36:52 GMT",
"version": "v2"
}
] |
2009-11-11
|
[
[
"Gerasyuta",
"S. M.",
""
],
[
"Kochkin",
"V. I.",
""
]
] |
The relativistic five-quark equations are found in the framework of the dispersion relation technique. The solutions of these equations using the method based on the extraction of the leading singularities of the amplitudes are obtained. The five-quark amplitudes for the low-lying pentaquarks including the u, d, s- quarks are calculated. The poles of these amplitudes determine the masses of the negative parity pentaquarks with I = 0, 1 and spin 3/2-, 5/2-. The mass of the lowest pentaquark with I = 0 and spin 3/2- is equal to 1514 MeV.
|
1504.03230
|
Alexander Kartavtsev
|
A. Kartavtsev, G. Raffelt, and H. Vogel
|
Neutrino propagation in media: Flavor-, helicity-, and pair correlations
|
21 pages, matches the published version
|
Phys. Rev. D 91, 125020 (2015)
|
10.1103/PhysRevD.91.125020
|
MPP-2015-45
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Neutrinos propagating in media (matter and electromagnetic fields) undergo
flavor and helicity oscillations, where helicity transitions are instigated
both by electromagnetic fields and matter currents. In addition, it has been
shown that correlations between neutrinos and antineutrinos of opposite
momentum can build up in anisotropic media. We re-derive the neutrino equations
of motion in the mean-field approximation for homogeneous yet anisotropic
media, confirming previous results except for a small correction in the
Majorana case. Furthermore, we derive the mean-field Hamiltonian induced by
neutrino electromagnetic interactions. We also provide a phenomenological
discussion of pair correlations in comparison with helicity correlations.
|
[
{
"created": "Thu, 9 Apr 2015 20:00:43 GMT",
"version": "v1"
},
{
"created": "Wed, 17 Jun 2015 08:55:05 GMT",
"version": "v2"
}
] |
2015-06-18
|
[
[
"Kartavtsev",
"A.",
""
],
[
"Raffelt",
"G.",
""
],
[
"Vogel",
"H.",
""
]
] |
Neutrinos propagating in media (matter and electromagnetic fields) undergo flavor and helicity oscillations, where helicity transitions are instigated both by electromagnetic fields and matter currents. In addition, it has been shown that correlations between neutrinos and antineutrinos of opposite momentum can build up in anisotropic media. We re-derive the neutrino equations of motion in the mean-field approximation for homogeneous yet anisotropic media, confirming previous results except for a small correction in the Majorana case. Furthermore, we derive the mean-field Hamiltonian induced by neutrino electromagnetic interactions. We also provide a phenomenological discussion of pair correlations in comparison with helicity correlations.
|
hep-ph/9712296
|
Mohammad Ahmady
|
M. R. Ahmady (RIKEN), E. Kou and A. Sugamoto (Ochanomizu Univ.)
|
Non-spectator contributions to B->X_s eta'
|
5 Pages. Latex (using sprocl.sty), Talk presented at the Pacific
Particle Physics Phenomenology Workshop, Seoul, Oct. 31- Nov. 2, 1997
| null | null | null |
hep-ph
| null |
We propose a nonspectator mechanism in which eta' is produced by two gluon
fusion as the underlying process to explain the inclusive B-> X_s eta' as well
as the exclusive B -> K^(*) eta' decays.
|
[
{
"created": "Mon, 8 Dec 1997 13:24:39 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Ahmady",
"M. R.",
"",
"RIKEN"
],
[
"Kou",
"E.",
"",
"Ochanomizu Univ."
],
[
"Sugamoto",
"A.",
"",
"Ochanomizu Univ."
]
] |
We propose a nonspectator mechanism in which eta' is produced by two gluon fusion as the underlying process to explain the inclusive B-> X_s eta' as well as the exclusive B -> K^(*) eta' decays.
|
0705.0180
|
Dietrich Bodeker
|
D. Bodeker (Bielefeld U), K. Rummukainen (Oulu U)
|
Non-abelian plasma instabilities for strong anisotropy
|
28 pages, 17 figures
|
JHEP0707:022,2007
|
10.1088/1126-6708/2007/07/022
| null |
hep-ph
| null |
We numerically investigate gauge field instabilities in anisotropic SU(2)
plasmas using weak field initial conditions. The growth of unstable modes is
stopped by non-abelian effects for moderate anisotropy. If we increase the
anisotropy the growth continues beyond the non-abelian saturation bound. We
find strong indications that the continued growth is not due to over-saturation
of infrared field modes, but instead due to very rapid growth of high momentum
modes which are not unstable in the weak field limit. The saturation amplitude
strongly depends on the initial conditions. For strong initial fields we do not
observe the sustained growth.
|
[
{
"created": "Tue, 1 May 2007 20:56:41 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Bodeker",
"D.",
"",
"Bielefeld U"
],
[
"Rummukainen",
"K.",
"",
"Oulu U"
]
] |
We numerically investigate gauge field instabilities in anisotropic SU(2) plasmas using weak field initial conditions. The growth of unstable modes is stopped by non-abelian effects for moderate anisotropy. If we increase the anisotropy the growth continues beyond the non-abelian saturation bound. We find strong indications that the continued growth is not due to over-saturation of infrared field modes, but instead due to very rapid growth of high momentum modes which are not unstable in the weak field limit. The saturation amplitude strongly depends on the initial conditions. For strong initial fields we do not observe the sustained growth.
|
0911.1962
|
Walter T. Giele
|
Walter Giele, Zoltan Kunszt and Jan Winter
|
Efficient Color-Dressed Calculation of Virtual Corrections
|
48 pages, 23 figures
|
Nucl.Phys.B840:214-270,2010
|
10.1016/j.nuclphysb.2010.07.007
|
Fermilab-PUB-09-406-T
|
hep-ph
|
http://creativecommons.org/licenses/publicdomain/
|
With the advent of generalized unitarity and parametric integration
techniques, the construction of a generic Next-to-Leading Order Monte Carlo
becomes feasible. Such a generator will entail the treatment of QCD color in
the amplitudes. We extend the concept of color dressing to one-loop amplitudes,
resulting in the formulation of an explicit algorithmic solution for the
calculation of arbitrary scattering processes at Next-to-Leading order. The
resulting algorithm is of exponential complexity, that is the numerical
evaluation time of the virtual corrections grows by a constant multiplicative
factor as the number of external partons is increased. To study the properties
of the method, we calculate the virtual corrections to $n$-gluon scattering.
|
[
{
"created": "Tue, 10 Nov 2009 18:27:35 GMT",
"version": "v1"
}
] |
2014-11-20
|
[
[
"Giele",
"Walter",
""
],
[
"Kunszt",
"Zoltan",
""
],
[
"Winter",
"Jan",
""
]
] |
With the advent of generalized unitarity and parametric integration techniques, the construction of a generic Next-to-Leading Order Monte Carlo becomes feasible. Such a generator will entail the treatment of QCD color in the amplitudes. We extend the concept of color dressing to one-loop amplitudes, resulting in the formulation of an explicit algorithmic solution for the calculation of arbitrary scattering processes at Next-to-Leading order. The resulting algorithm is of exponential complexity, that is the numerical evaluation time of the virtual corrections grows by a constant multiplicative factor as the number of external partons is increased. To study the properties of the method, we calculate the virtual corrections to $n$-gluon scattering.
|
hep-ph/0106290
|
Carl E. Carlson
|
Carl E. Carlson (William and Mary)
|
Baryon Form Factors in QCD
|
Invited talk (W09) at Workshop on "e+e- Physics at Intermediate
Energies", SLAC, April 30 - May 2, 2001, Latex, 5 pages, 1 figures, uses
JAC2000.cls
|
eConf C010430 (2001) W09
| null |
WM-01-109
|
hep-ph
| null |
This is a summary of perturbative QCD calculations of baryon form factors.
For e^+ e^- going to baryon-antibaryon pairs, normalized calculations are
available and reported for the entire ground state octet and decuplet,
including off-diagonal form factors, and for the S_{11}(1535)-antiS_{11}. (The
latter results are new for this report.) We also include some explanation of
how the results come to be.
|
[
{
"created": "Tue, 26 Jun 2001 18:56:30 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Carlson",
"Carl E.",
"",
"William and Mary"
]
] |
This is a summary of perturbative QCD calculations of baryon form factors. For e^+ e^- going to baryon-antibaryon pairs, normalized calculations are available and reported for the entire ground state octet and decuplet, including off-diagonal form factors, and for the S_{11}(1535)-antiS_{11}. (The latter results are new for this report.) We also include some explanation of how the results come to be.
|
1812.06225
|
Dmytro Oliinychenko
|
Dmytro Oliinychenko, Long-Gang Pang, Hannah Elfner and Volker Koch
|
Centrality dependence of deuteron production in Pb+Pb collisions at 2.76
TeV via hydrodynamics and hadronic afterburner
|
Proceedings of Hot Quarks 2018, 4 pages, 2 figures
| null | null | null |
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The deuteron binding energy is only 2.2 MeV. At the same time, its yield in
Pb+Pb collisions at $\sqrt{s_{NN}} = $2.76 TeV corresponds to a thermal yield
at the temperature around 155 MeV, which is too hot to keep deuterons bound.
This puzzle is not completely resolved yet. In general, the mechanism of light
nuclei production in ultra-high energy heavy ion collisions remains under
debate. In a previous work [1] we suggest a microscopic explanation of the
deuteron production in central ultra-relativistic Pb+Pb collisions, the main
mechanism being $\pi pn \leftrightarrow \pi d$ reactions in the hadronic phase
of the collision. We use a state-of-the-art hybrid approach, combining
relativistic hydrodynamics for the hot and dense stage and hadronic transport
for a later, more dilute stage. Deuteron rescattering in the hadronic stage is
implemented explicitly, using its experimentally measured vacuum
cross-sections. In these proceedings we extend our previous work to non-central
collisions, keeping exactly the same methodology and parameters. We find that
our approach leads to a good description of the measured deuteron transverse
momentum spectra at centralities up to 40%, and underestimates the amount of
deuterons at low transverse momentum at higher centralities. Nevertheless, the
coalescence parameter $B_2$, measured by ALICE collaboration, is reproduced
well in our approach even for peripheral collisions.
|
[
{
"created": "Sat, 15 Dec 2018 02:43:35 GMT",
"version": "v1"
}
] |
2019-05-07
|
[
[
"Oliinychenko",
"Dmytro",
""
],
[
"Pang",
"Long-Gang",
""
],
[
"Elfner",
"Hannah",
""
],
[
"Koch",
"Volker",
""
]
] |
The deuteron binding energy is only 2.2 MeV. At the same time, its yield in Pb+Pb collisions at $\sqrt{s_{NN}} = $2.76 TeV corresponds to a thermal yield at the temperature around 155 MeV, which is too hot to keep deuterons bound. This puzzle is not completely resolved yet. In general, the mechanism of light nuclei production in ultra-high energy heavy ion collisions remains under debate. In a previous work [1] we suggest a microscopic explanation of the deuteron production in central ultra-relativistic Pb+Pb collisions, the main mechanism being $\pi pn \leftrightarrow \pi d$ reactions in the hadronic phase of the collision. We use a state-of-the-art hybrid approach, combining relativistic hydrodynamics for the hot and dense stage and hadronic transport for a later, more dilute stage. Deuteron rescattering in the hadronic stage is implemented explicitly, using its experimentally measured vacuum cross-sections. In these proceedings we extend our previous work to non-central collisions, keeping exactly the same methodology and parameters. We find that our approach leads to a good description of the measured deuteron transverse momentum spectra at centralities up to 40%, and underestimates the amount of deuterons at low transverse momentum at higher centralities. Nevertheless, the coalescence parameter $B_2$, measured by ALICE collaboration, is reproduced well in our approach even for peripheral collisions.
|
hep-ph/9812407
|
Michael Spira
|
Michael Spira
|
SUSY Particle Production at Hadron Colliders
|
10 pages, latex, 9 figures
| null | null |
DESY 98-207
|
hep-ph
| null |
The determination of the full SUSY QCD corrections to the production of
squarks, gluinos and gauginos at hadron colliders is reviewed. The NLO
corrections stabilize the theoretical predictions of the various production
cross sections significantly and lead to sizeable enhancements of the most
relevant cross sections. We discuss the phenomenological consequences of the
results on present and future experimental analyses.
|
[
{
"created": "Thu, 17 Dec 1998 08:02:25 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Spira",
"Michael",
""
]
] |
The determination of the full SUSY QCD corrections to the production of squarks, gluinos and gauginos at hadron colliders is reviewed. The NLO corrections stabilize the theoretical predictions of the various production cross sections significantly and lead to sizeable enhancements of the most relevant cross sections. We discuss the phenomenological consequences of the results on present and future experimental analyses.
|
hep-ph/9904340
|
Walter Grimus
|
W. Grimus (Univ. Vienna), S. Mohanty (PRL, Ahmedabad), P. Stockinger
(PRL, Ahmedabad)
|
Field-theoretical treatment of neutrino oscillations
|
6 pages, revtex, talk presented by W. Grimus at WIN99, Capetown,
South Africa, January 24-30, 1999
| null | null |
UWThPh-1999-25, PRL-TH-1999
|
hep-ph
| null |
We discuss the field-theoretical approach to neutrino oscillations. This
approach includes the neutrino source and detector processes and allows to
obtain the neutrino transition or survival probabilities as cross sections
derived from the Feynman diagram of the combined source -- detection process.
In this context, the neutrinos which are supposed to oscillate appear as
propagators of the neutrino mass eigenfields, connecting the source and
detection processes.
|
[
{
"created": "Thu, 15 Apr 1999 08:53:21 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Grimus",
"W.",
"",
"Univ. Vienna"
],
[
"Mohanty",
"S.",
"",
"PRL, Ahmedabad"
],
[
"Stockinger",
"P.",
"",
"PRL, Ahmedabad"
]
] |
We discuss the field-theoretical approach to neutrino oscillations. This approach includes the neutrino source and detector processes and allows to obtain the neutrino transition or survival probabilities as cross sections derived from the Feynman diagram of the combined source -- detection process. In this context, the neutrinos which are supposed to oscillate appear as propagators of the neutrino mass eigenfields, connecting the source and detection processes.
|
2405.18101
|
Sam Van Thurenhout
|
S. Van Thurenhout
|
Anomalous dimensions for hard exclusive processes
|
15 pages, LateX, 1 figure, Proceedings to the XXXI International
Workshop on Deep Inelastic Scattering and Related Subjects (DIS2024)
| null | null | null |
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We give an overview of recent developments in the computation of the
anomalous dimension matrix of composite operators in non-forward kinematics.
The elements of this matrix determine the scale dependence of non-perturbative
parton distributions, such as GPDs, and hence constitute important input for
phenomenological studies of exclusive processes like deeply-virtual Compton
scattering. Particular emphasis will be put on a recently developed method that
exploits consistency relations for the anomalous dimension matrix which follow
from the renormalization structure of the operators.
|
[
{
"created": "Tue, 28 May 2024 12:08:37 GMT",
"version": "v1"
}
] |
2024-05-29
|
[
[
"Van Thurenhout",
"S.",
""
]
] |
We give an overview of recent developments in the computation of the anomalous dimension matrix of composite operators in non-forward kinematics. The elements of this matrix determine the scale dependence of non-perturbative parton distributions, such as GPDs, and hence constitute important input for phenomenological studies of exclusive processes like deeply-virtual Compton scattering. Particular emphasis will be put on a recently developed method that exploits consistency relations for the anomalous dimension matrix which follow from the renormalization structure of the operators.
|
hep-ph/0104219
|
Dr A. N. Mitra
|
A. N. Mitra and B. M. Sodermark
|
Markov-Yukawa Transversality On Covariant Null-Plane: Baryon Form Factor
And Magnetic Moments
|
LaTeX file, 16 pages dvi
| null | null | null |
hep-ph nucl-th
| null |
The baryon-$qqq$ vertex function governed by the Markov-Yukawa Transversality
Principle ($MYTP$), is formulated via the Covariant Null-Plane Ansatz ($CNPA$)
as a 3-body generalization of the corresponding $q{\bar q}$ problem, and
employed to calculate the proton e.m. form factor and baryon octet magnetic
moments.The e.m. coupling scheme is specified by letting the e.m. field
interact by turn with the `spectator' while the two interacting quarks fold
back into the baryon. The $S_3$ symmetry of the matrix element is preserved in
all d.o.f.'s together. The $CNPA$ formulation ensures, as in the $q{\bar q}$
case, that the loop integral is free from the Lorentz mismatch disease of
covariant instantaneity ($CIA$), while the simple trick of `Lorentz
completion'ensures a Lorentz invariant structure. The $k^{-4}$ scaling
behaviour at large $k^2$ is reproduced. And with the infrared structure of the
gluonic propagator attuned to spectroscopy, the charge radius of the proton
comes out at $0.96 fm$. The magnetic moments of the baryon octet, also in good
accord with data, are expressible as $(a+b\lambda)/(2+\lambda)$, where $a,b$
are purely geometrical numbers and $\lambda$ a dynamics-dependent quantity.
PACS: 11.10.St ; 12.90.+b ; 13.40.Fn Key Words : Baryon-$qqq$ Vertex;
Markov-Yukawa Principle (MYTP); 3D-4D Interlinkage; Covariant null-plane
(CNPA); e.m.form factor;baryon magneton.
|
[
{
"created": "Sun, 22 Apr 2001 17:33:33 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Mitra",
"A. N.",
""
],
[
"Sodermark",
"B. M.",
""
]
] |
The baryon-$qqq$ vertex function governed by the Markov-Yukawa Transversality Principle ($MYTP$), is formulated via the Covariant Null-Plane Ansatz ($CNPA$) as a 3-body generalization of the corresponding $q{\bar q}$ problem, and employed to calculate the proton e.m. form factor and baryon octet magnetic moments.The e.m. coupling scheme is specified by letting the e.m. field interact by turn with the `spectator' while the two interacting quarks fold back into the baryon. The $S_3$ symmetry of the matrix element is preserved in all d.o.f.'s together. The $CNPA$ formulation ensures, as in the $q{\bar q}$ case, that the loop integral is free from the Lorentz mismatch disease of covariant instantaneity ($CIA$), while the simple trick of `Lorentz completion'ensures a Lorentz invariant structure. The $k^{-4}$ scaling behaviour at large $k^2$ is reproduced. And with the infrared structure of the gluonic propagator attuned to spectroscopy, the charge radius of the proton comes out at $0.96 fm$. The magnetic moments of the baryon octet, also in good accord with data, are expressible as $(a+b\lambda)/(2+\lambda)$, where $a,b$ are purely geometrical numbers and $\lambda$ a dynamics-dependent quantity. PACS: 11.10.St ; 12.90.+b ; 13.40.Fn Key Words : Baryon-$qqq$ Vertex; Markov-Yukawa Principle (MYTP); 3D-4D Interlinkage; Covariant null-plane (CNPA); e.m.form factor;baryon magneton.
|
2211.16539
|
Stephen P. Martin
|
Stephen P. Martin
|
Evaluation of three-loop self-energy master integrals with four or five
propagators
|
36 pages, 2 ancillary files. v2 contains a new section on numerical
evaluation, including some benchmarks, and some more explanations
| null |
10.1103/PhysRevD.107.053005
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
I obtain identities satisfied by the 3-loop self-energy master integrals with
four or five propagators with generic masses, including the derivatives with
respect to each of the squared masses and the external momentum invariant.
These identities are then recast in terms of the corresponding renormalized
master integrals, enabling straightforward numerical evaluation of them by the
differential equations approach. Some benchmark examples are provided. The
method used to obtain the derivative identities relies only on the general form
implied by integration by parts relations, without actually following the usual
integration by parts reduction procedure. As a byproduct, I find a simple
formula giving the expansion of the master integrals to arbitrary order in the
external momentum invariant, in terms of known derivatives of the corresponding
vacuum integrals.
|
[
{
"created": "Tue, 29 Nov 2022 19:03:55 GMT",
"version": "v1"
},
{
"created": "Mon, 6 Feb 2023 04:13:29 GMT",
"version": "v2"
}
] |
2023-03-29
|
[
[
"Martin",
"Stephen P.",
""
]
] |
I obtain identities satisfied by the 3-loop self-energy master integrals with four or five propagators with generic masses, including the derivatives with respect to each of the squared masses and the external momentum invariant. These identities are then recast in terms of the corresponding renormalized master integrals, enabling straightforward numerical evaluation of them by the differential equations approach. Some benchmark examples are provided. The method used to obtain the derivative identities relies only on the general form implied by integration by parts relations, without actually following the usual integration by parts reduction procedure. As a byproduct, I find a simple formula giving the expansion of the master integrals to arbitrary order in the external momentum invariant, in terms of known derivatives of the corresponding vacuum integrals.
|
hep-ph/9511210
|
Nils A. Tornqvist
|
Nils A. Tornqvist and Matts Roos (Helsinki)
|
Resurrection of the Sigma Meson
|
13 pages in Latex using RevTex (and psfig.sty), 4 figures available
as ps files from N. To"rnqvist (Tornqvist@phcu.Helsinki.Fi) on request
|
Phys.Rev.Lett.76:1575-1578,1996
|
10.1103/PhysRevLett.76.1575
|
HU-SEFT-R-1995-15
|
hep-ph nucl-th
| null |
It is shown from a very general model and an analysis of data on the lightest
0++ meson nonet that the f0(980) and f0(1200) resonance poles are two
manifestations of the same ss state. Similarily the a0(980) and the a0(1450)
are likely to be two manifestations of the same qq state. On the other hand,
the uu+dd state, when unitarized and strongly distorted by hadronic mass
shifts, becomes an extremely broad Breit-Wigner-like background, m=860 MeV,
Gamma=880 MeV, with its pole at s=(0.158-i0.235) GeV^2. This we identify with
the sigma meson required by models for spontaneous breaking of chiral symmetry.
|
[
{
"created": "Thu, 2 Nov 1995 07:11:52 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Tornqvist",
"Nils A.",
"",
"Helsinki"
],
[
"Roos",
"Matts",
"",
"Helsinki"
]
] |
It is shown from a very general model and an analysis of data on the lightest 0++ meson nonet that the f0(980) and f0(1200) resonance poles are two manifestations of the same ss state. Similarily the a0(980) and the a0(1450) are likely to be two manifestations of the same qq state. On the other hand, the uu+dd state, when unitarized and strongly distorted by hadronic mass shifts, becomes an extremely broad Breit-Wigner-like background, m=860 MeV, Gamma=880 MeV, with its pole at s=(0.158-i0.235) GeV^2. This we identify with the sigma meson required by models for spontaneous breaking of chiral symmetry.
|
1510.02233
|
Raquel Gomez-Ambrosio
|
Raquel Gomez-Ambrosio
|
Effective field theories and pseudo-observables in the quest for physics
beyond the Standard Model
|
Proceeding for the 18th International Conference From the Planck
Scale to the Electroweak Scale (Ioannina, Greece, 25-29 May 2015), 10 pages
|
PoS(PLANCK 2015)049
| null | null |
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We discuss briefly the kappa framework, proposed originally as a test for the
Higgs couplings of the Standard Model (SM). Further, we discuss a
generalization of this idea in terms of effective field theory. We sketch how
to add dimension 6 operators to the SM Lagrangian and the renormalization
process. Finally we show how to study the amplitudes of the resulting model at
next-to-leading order and discuss possible experimental approaches.
|
[
{
"created": "Thu, 8 Oct 2015 08:33:12 GMT",
"version": "v1"
}
] |
2015-10-12
|
[
[
"Gomez-Ambrosio",
"Raquel",
""
]
] |
We discuss briefly the kappa framework, proposed originally as a test for the Higgs couplings of the Standard Model (SM). Further, we discuss a generalization of this idea in terms of effective field theory. We sketch how to add dimension 6 operators to the SM Lagrangian and the renormalization process. Finally we show how to study the amplitudes of the resulting model at next-to-leading order and discuss possible experimental approaches.
|
hep-ph/9702222
|
Jordi Vidal-Perona
|
J. Bernabeu, G.A. Gonzalez-Sprinberg, J. Vidal
|
The Weak-Magnetic Moment of Heavy Quarks
|
12 pages, 1 Postscript figure, LaTeX. 1 reference corrected.
Published in Phys. Lett. B
|
Phys.Lett.B397:255-262,1997
|
10.1016/S0370-2693(97)00185-8
| null |
hep-ph
| null |
With initial and final particles on-shell, the anomalous weak-magnetic dipole
moments of b and c quarks are electroweak gauge invariant quantities of the
effective couplings Zb\bar{b} and Zc\bar{c}, respectively, and good candidates
to test the Standard Model and/or new physics. Here we present a complete
computation of these quantities within the Standard Model. We show that
decoupling properties with respect to heavy particles do take place in the weak
magnetic moment. The obtained values, a_b(M_Z^2)=(2.98-1.56i)x10^(-4) and
a_c(M_Z^2)=(-2.80+1.09i)x10^(-5) are dominated by one-gluon exchange diagrams.
The electroweak corrections are less than 1% of the total magnitude.
|
[
{
"created": "Mon, 3 Feb 1997 11:32:59 GMT",
"version": "v1"
},
{
"created": "Fri, 18 Apr 1997 14:40:03 GMT",
"version": "v2"
}
] |
2011-01-25
|
[
[
"Bernabeu",
"J.",
""
],
[
"Gonzalez-Sprinberg",
"G. A.",
""
],
[
"Vidal",
"J.",
""
]
] |
With initial and final particles on-shell, the anomalous weak-magnetic dipole moments of b and c quarks are electroweak gauge invariant quantities of the effective couplings Zb\bar{b} and Zc\bar{c}, respectively, and good candidates to test the Standard Model and/or new physics. Here we present a complete computation of these quantities within the Standard Model. We show that decoupling properties with respect to heavy particles do take place in the weak magnetic moment. The obtained values, a_b(M_Z^2)=(2.98-1.56i)x10^(-4) and a_c(M_Z^2)=(-2.80+1.09i)x10^(-5) are dominated by one-gluon exchange diagrams. The electroweak corrections are less than 1% of the total magnitude.
|
hep-ph/0510104
|
Dan Pirjol
|
Benjamin Grinstein and Dan Pirjol
|
The CP asymmetry in B^0(t) -> K_S \pi^0 \gamma in the Standard Model
|
11 pages, 4 figures. Final version to appear in Physical Review D
|
Phys.Rev.D73:014013,2006
|
10.1103/PhysRevD.73.014013
|
UCSD/PTH 05-12, MIT-CTP 3674
|
hep-ph hep-ex
| null |
The time-dependent CP asymmetry in exclusive B^0(t) -> K^{*0}\gamma decays
has been proposed as a probe of new physics in B decays. Recently, this method
was extended to radiative decays into multibody hadronic final states such as
B^0(t)-> K_S\pi^0\gamma and B^0(t)-> \pi^+\pi^-\gamma. The CP asymmetry in
these decays vanishes to the extent that the photon is completely polarized. In
the Standard Model, the photon emitted in b-> s\gamma has high left-handed
polarization, but right-handed contamination enters already at leading order in
\Lambda/m_b even for vanishing light quark masses. We compute here the
magnitude of this effect and the time dependent CP asymmetry parameter S_{K_S
\pi^0\gamma}. We find that the Standard Model can easily accomodate values of S
as large as 10%, but a precise value cannot be obtained at present because of
strong interactions uncertainties.
|
[
{
"created": "Mon, 10 Oct 2005 18:04:16 GMT",
"version": "v1"
},
{
"created": "Tue, 11 Oct 2005 16:11:04 GMT",
"version": "v2"
},
{
"created": "Sun, 8 Jan 2006 05:16:09 GMT",
"version": "v3"
}
] |
2014-11-18
|
[
[
"Grinstein",
"Benjamin",
""
],
[
"Pirjol",
"Dan",
""
]
] |
The time-dependent CP asymmetry in exclusive B^0(t) -> K^{*0}\gamma decays has been proposed as a probe of new physics in B decays. Recently, this method was extended to radiative decays into multibody hadronic final states such as B^0(t)-> K_S\pi^0\gamma and B^0(t)-> \pi^+\pi^-\gamma. The CP asymmetry in these decays vanishes to the extent that the photon is completely polarized. In the Standard Model, the photon emitted in b-> s\gamma has high left-handed polarization, but right-handed contamination enters already at leading order in \Lambda/m_b even for vanishing light quark masses. We compute here the magnitude of this effect and the time dependent CP asymmetry parameter S_{K_S \pi^0\gamma}. We find that the Standard Model can easily accomodate values of S as large as 10%, but a precise value cannot be obtained at present because of strong interactions uncertainties.
|
hep-ph/0108124
|
Luba Razdolskaya
|
E.Gedalin, A.Moalem and L.Razdolskaya
|
A Chiral Effective Field Theory and Radiative Decays of Mesons
|
15 pages
| null | null | null |
hep-ph
| null |
An extended $U(3)_L\bigotimes U(3)_R$ chiral effective field theory which
includes pseudoscalar and vector meson nonets as dynamic variables is
presented. The theory combines a hidden symmetry approach with a general
procedure of including the $\eta'$ meson into chiral theory, and accounts for
$direct$ and $indirect$ symmetry breaking effects via a mechanism based on the
quark mass matrix. The theory is applied to anomalous radiative decays using
particle mixing schemes, corresponding to different symmetry breaking
assumptions and uniquely determined by the lagarngian presumed. Radiative
decays of light flavor mesons are best explained within the framework of a one
mixing angle scheme and provide evidence for $SU(3)_F$ and nonet symmetry
breaking.
|
[
{
"created": "Wed, 15 Aug 2001 07:15:29 GMT",
"version": "v1"
},
{
"created": "Wed, 2 Jan 2002 10:37:21 GMT",
"version": "v2"
}
] |
2007-05-23
|
[
[
"Gedalin",
"E.",
""
],
[
"Moalem",
"A.",
""
],
[
"Razdolskaya",
"L.",
""
]
] |
An extended $U(3)_L\bigotimes U(3)_R$ chiral effective field theory which includes pseudoscalar and vector meson nonets as dynamic variables is presented. The theory combines a hidden symmetry approach with a general procedure of including the $\eta'$ meson into chiral theory, and accounts for $direct$ and $indirect$ symmetry breaking effects via a mechanism based on the quark mass matrix. The theory is applied to anomalous radiative decays using particle mixing schemes, corresponding to different symmetry breaking assumptions and uniquely determined by the lagarngian presumed. Radiative decays of light flavor mesons are best explained within the framework of a one mixing angle scheme and provide evidence for $SU(3)_F$ and nonet symmetry breaking.
|
1207.2301
|
Jakub Wagner
|
B. Pire, L. Szymanowski and J. Wagner
|
Timelike Compton Scattering from JLAB to RHIC and LHC energies
|
Presented at Sixth International Conference on Quarks and Nuclear
Physics, April 16-20, 2012, Ecole Polytechnique, Palaiseau, France
| null | null | null |
hep-ph hep-ex nucl-ex nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Timelike Compton scattering (TCS) i.e. the exclusive photoproduction of a
lepton pair with large invariant mass nicely complements the already successful
experimental study of deeply virtual Compton scattering (DVCS). The same
Generalized Parton Distributions enter both amplitudes, which offer a
promissing way to access the quark and gluon nucleon structure. We review
recent progress in this domain, emphasizing the fact that analyticity and
factorization properties dictate the relation of the NLO corrections to TCS to
those of DVCS. We also stress that data on TCS at high energy should be
available soon thanks to the proposed experimental program at JLab at 12 GeV,
and that, before the future high energy electron ion colliders become reality,
the study of ultraperipheral collisions at the RHIC and LHC may open a window
on quark and gluon GPDs at very small skewness. .
|
[
{
"created": "Tue, 10 Jul 2012 10:41:06 GMT",
"version": "v1"
}
] |
2012-07-12
|
[
[
"Pire",
"B.",
""
],
[
"Szymanowski",
"L.",
""
],
[
"Wagner",
"J.",
""
]
] |
Timelike Compton scattering (TCS) i.e. the exclusive photoproduction of a lepton pair with large invariant mass nicely complements the already successful experimental study of deeply virtual Compton scattering (DVCS). The same Generalized Parton Distributions enter both amplitudes, which offer a promissing way to access the quark and gluon nucleon structure. We review recent progress in this domain, emphasizing the fact that analyticity and factorization properties dictate the relation of the NLO corrections to TCS to those of DVCS. We also stress that data on TCS at high energy should be available soon thanks to the proposed experimental program at JLab at 12 GeV, and that, before the future high energy electron ion colliders become reality, the study of ultraperipheral collisions at the RHIC and LHC may open a window on quark and gluon GPDs at very small skewness. .
|
hep-ph/0107188
|
Hanqing Zheng
|
Zhiguang Xiao and Hanqing Zheng
|
The Use of Analyticity in the $\pi\pi$ and $K\bar K$ Coupled Channel
System
|
Summary of talks given at International Conference on Flavor Physics
2001, Zhangjiajie, Hunan, May 30th, 2001, at BES annual meeting, and at
Eurodaphne workshop on Nonperturbative Methods in Chiral Theories, Valencia,
Spain, June 28th, 2001. To appear in the proceedings
| null | null | null |
hep-ph
| null |
Studies on the IJ=00 $\pi\pi$ and $K\bar K$ coupled--channel system are made
using newly derived dispersion relations between the phase shifts and poles and
cuts. It is found that the $\sigma$ resonance must be introduced to explain the
experimental phase shifts, after evaluating the cut contribution. The effects
of nearby branch point singularities to the determination of the $f_0(980)$
resonance are also carefully clarified.
|
[
{
"created": "Tue, 17 Jul 2001 10:26:25 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Xiao",
"Zhiguang",
""
],
[
"Zheng",
"Hanqing",
""
]
] |
Studies on the IJ=00 $\pi\pi$ and $K\bar K$ coupled--channel system are made using newly derived dispersion relations between the phase shifts and poles and cuts. It is found that the $\sigma$ resonance must be introduced to explain the experimental phase shifts, after evaluating the cut contribution. The effects of nearby branch point singularities to the determination of the $f_0(980)$ resonance are also carefully clarified.
|
hep-ph/9606407
|
Jerry Franklin
|
Jerrold Franklin
|
The proper identification of the heavy baryons
|
The two paragraphs following Eq. (7) have been revised, with no
change in the conclusion. Five pages in LaTeX
| null | null |
TUHE-9662
|
hep-ph
| null |
The new designation of heavy baryons proposed by Falk (hep-ph/9603389) is
shown to violate minimal symmetry sum rules.
|
[
{
"created": "Fri, 21 Jun 1996 17:32:16 GMT",
"version": "v1"
},
{
"created": "Tue, 25 Jun 1996 19:04:37 GMT",
"version": "v2"
}
] |
2008-02-03
|
[
[
"Franklin",
"Jerrold",
""
]
] |
The new designation of heavy baryons proposed by Falk (hep-ph/9603389) is shown to violate minimal symmetry sum rules.
|
2204.04200
|
Tobias Neumann
|
Fernando Febres Cordero, Andreas von Manteuffel and Tobias Neumann
|
Computational challenges for multi-loop collider phenomenology
|
29 pages, 1 figure, white paper contribution to the Snowmass 2021
computational frontier
|
Comput.Softw.Big Sci. 6 (2022) 1, 14
|
10.1007/s41781-022-00088-0
|
MSUHEP-22-016
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Precision measurements at the LHC and future colliders require theory
predictions with uncertainties at the percent level for many observables.
Theory uncertainties due to the perturbative truncation are particularly
relevant and must be reduced to fully exploit the physics potential of collider
experiments. In recent years the theoretical high energy physics community has
made tremendous analytical and numerical advances to address this challenge. In
this white paper, we survey state-of-the-art calculations in perturbative
quantum field theory for collider phenomenology with a particular focus on the
computational requirements at high perturbative orders. We show that these
calculations can have specific high-performance-computing (HPC) profiles that
should to be taken into account in future HPC resource planning.
|
[
{
"created": "Fri, 8 Apr 2022 17:51:51 GMT",
"version": "v1"
}
] |
2022-09-14
|
[
[
"Cordero",
"Fernando Febres",
""
],
[
"von Manteuffel",
"Andreas",
""
],
[
"Neumann",
"Tobias",
""
]
] |
Precision measurements at the LHC and future colliders require theory predictions with uncertainties at the percent level for many observables. Theory uncertainties due to the perturbative truncation are particularly relevant and must be reduced to fully exploit the physics potential of collider experiments. In recent years the theoretical high energy physics community has made tremendous analytical and numerical advances to address this challenge. In this white paper, we survey state-of-the-art calculations in perturbative quantum field theory for collider phenomenology with a particular focus on the computational requirements at high perturbative orders. We show that these calculations can have specific high-performance-computing (HPC) profiles that should to be taken into account in future HPC resource planning.
|
2308.13227
|
Pheiroijam Wilina
|
Ph. Wilina and N. Nimai Singh
|
Deviations from $\mu$-$\tau$ symmetry using $\Delta$(27) group on
neutrino masses and mixings
|
23 pages, 20 figures, 5 tables
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Implication of neutrino mass model based on $\Delta$(27) discrete flavor
symmetry, on parameters of neutrino oscillations, CP violation and effective
neutrino masses is studied using type-I seesaw mechanism. The Standard Model
particle content is extended by adding two additional Higgs doublets, three
right-handed neutrinos and two scalar triplets under $\Delta$(27) symmetry
predicting diagonal charged lepton mass matrix. This can generate the desired
deviation from $\mu - \tau$ symmetry. The resulting neutrino oscillation
parameters are well agreed with the latest global fit oscillation data. The sum
of the three absolute neutrino mass eigenvalues, $\sum\limits_{i}|m_{i}|$
(i=1,2,3) is found to be consistent with that of the value given by latest
Planck cosmological data, $\sum\limits_{i}|m_{i}|<$0.12 eV. The model further
predicts effective neutrino masses for neutrinoless double beta decay, 4.15 meV
$\leq m_{ee}\leq$ 30.6 meV, tritium beta decay, 8.4 meV $\leq m_{\beta}\leq$
30.5 meV, Jarlskog invariant, $J_{CP}=\pm 0.022$ for CP violation, baryon
asymmetry $Y_{B}=1.15 \times 10^{-10}$ for normal hierarchical case; and also
49.5 meV $\leq m_{ee}\leq$ 51.7 meV, 49.5 meV $\leq m_{\beta}\leq$ 51.4 meV,
$J_{CP}=\pm 0.022$, $Y_{B}=1.12\times 10^{-10}$ for inverted hierarchical case
respectively.
|
[
{
"created": "Fri, 25 Aug 2023 07:56:00 GMT",
"version": "v1"
},
{
"created": "Mon, 18 Dec 2023 05:34:32 GMT",
"version": "v2"
}
] |
2023-12-19
|
[
[
"Wilina",
"Ph.",
""
],
[
"Singh",
"N. Nimai",
""
]
] |
Implication of neutrino mass model based on $\Delta$(27) discrete flavor symmetry, on parameters of neutrino oscillations, CP violation and effective neutrino masses is studied using type-I seesaw mechanism. The Standard Model particle content is extended by adding two additional Higgs doublets, three right-handed neutrinos and two scalar triplets under $\Delta$(27) symmetry predicting diagonal charged lepton mass matrix. This can generate the desired deviation from $\mu - \tau$ symmetry. The resulting neutrino oscillation parameters are well agreed with the latest global fit oscillation data. The sum of the three absolute neutrino mass eigenvalues, $\sum\limits_{i}|m_{i}|$ (i=1,2,3) is found to be consistent with that of the value given by latest Planck cosmological data, $\sum\limits_{i}|m_{i}|<$0.12 eV. The model further predicts effective neutrino masses for neutrinoless double beta decay, 4.15 meV $\leq m_{ee}\leq$ 30.6 meV, tritium beta decay, 8.4 meV $\leq m_{\beta}\leq$ 30.5 meV, Jarlskog invariant, $J_{CP}=\pm 0.022$ for CP violation, baryon asymmetry $Y_{B}=1.15 \times 10^{-10}$ for normal hierarchical case; and also 49.5 meV $\leq m_{ee}\leq$ 51.7 meV, 49.5 meV $\leq m_{\beta}\leq$ 51.4 meV, $J_{CP}=\pm 0.022$, $Y_{B}=1.12\times 10^{-10}$ for inverted hierarchical case respectively.
|
hep-ph/9812281
|
Mike Seymour
|
Richard Nisius (CERN), Michael H. Seymour (RAL)
|
QED Structure Functions of the Photon
|
7 pages, 3 eps figures
|
Phys.Lett. B452 (1999) 409-413
|
10.1016/S0370-2693(99)00261-0
|
RAL-TR-1998-079
|
hep-ph
| null |
In deep inelastic electron-photon scattering in leading order QED,
egamma->egamma*gamma->effbar, there are four non-zero structure functions. We
calculate them for real photons retaining the full dependence on the fermion
mass, and show numerical results of its effect.
|
[
{
"created": "Tue, 8 Dec 1998 18:04:27 GMT",
"version": "v1"
}
] |
2009-10-31
|
[
[
"Nisius",
"Richard",
"",
"CERN"
],
[
"Seymour",
"Michael H.",
"",
"RAL"
]
] |
In deep inelastic electron-photon scattering in leading order QED, egamma->egamma*gamma->effbar, there are four non-zero structure functions. We calculate them for real photons retaining the full dependence on the fermion mass, and show numerical results of its effect.
|
2311.09296
|
Tony Menzo
|
Christian Bierlich, Phil Ilten, Tony Menzo, Stephen Mrenna, Manuel
Szewc, Michael K. Wilkinson, Ahmed Youssef, Jure Zupan
|
Towards a data-driven model of hadronization using normalizing flows
|
26 pages, 9 figures, public code available
|
SciPost Phys. 17, 045 (2024)
|
10.21468/SciPostPhys.17.2.045
|
FERMILAB-PUB-23-698-CSAID
|
hep-ph hep-ex
|
http://creativecommons.org/licenses/by/4.0/
|
We introduce a model of hadronization based on invertible neural networks
that faithfully reproduces a simplified version of the Lund string model for
meson hadronization. Additionally, we introduce a new training method for
normalizing flows, termed MAGIC, that improves the agreement between simulated
and experimental distributions of high-level (macroscopic) observables by
adjusting single-emission (microscopic) dynamics. Our results constitute an
important step toward realizing a machine-learning based model of hadronization
that utilizes experimental data during training. Finally, we demonstrate how a
Bayesian extension to this normalizing-flow architecture can be used to provide
analysis of statistical and modeling uncertainties on the generated observable
distributions.
|
[
{
"created": "Wed, 15 Nov 2023 19:00:04 GMT",
"version": "v1"
},
{
"created": "Fri, 19 Apr 2024 18:32:46 GMT",
"version": "v2"
}
] |
2024-08-14
|
[
[
"Bierlich",
"Christian",
""
],
[
"Ilten",
"Phil",
""
],
[
"Menzo",
"Tony",
""
],
[
"Mrenna",
"Stephen",
""
],
[
"Szewc",
"Manuel",
""
],
[
"Wilkinson",
"Michael K.",
""
],
[
"Youssef",
"Ahmed",
""
],
[
"Zupan",
"Jure",
""
]
] |
We introduce a model of hadronization based on invertible neural networks that faithfully reproduces a simplified version of the Lund string model for meson hadronization. Additionally, we introduce a new training method for normalizing flows, termed MAGIC, that improves the agreement between simulated and experimental distributions of high-level (macroscopic) observables by adjusting single-emission (microscopic) dynamics. Our results constitute an important step toward realizing a machine-learning based model of hadronization that utilizes experimental data during training. Finally, we demonstrate how a Bayesian extension to this normalizing-flow architecture can be used to provide analysis of statistical and modeling uncertainties on the generated observable distributions.
|
2406.09705
|
Koji Ishiwata
|
Koji Ishiwata, Kentaro Nomura
|
Collective excitations in magnetic topological insulators and axion dark
matter search
|
18 pages, 13 figures
| null | null |
KANAZAWA-24-06
|
hep-ph astro-ph.CO cond-mat.str-el
|
http://creativecommons.org/licenses/by/4.0/
|
We investigate collective excitations in magnetic topological insulators
(TIs) and their impact on particle axion detection. In the three-dimensional TI
model with the Hubbard term, the effective action of magnons and amplitude
modes is formulated by dynamical susceptibility under the antiferromagnetic and
ferromagnetic states. One of the amplitude modes is identified as ``axionic''
quasi-particle and its effective coupling to the electromagnetic fields turns
out to be enhanced by about four orders of magnitude larger than the previous
estimate, which may drastically change the sensitivity of the particle axion
search using ``axion'' in magnetic TIs.
|
[
{
"created": "Fri, 14 Jun 2024 04:21:07 GMT",
"version": "v1"
}
] |
2024-06-17
|
[
[
"Ishiwata",
"Koji",
""
],
[
"Nomura",
"Kentaro",
""
]
] |
We investigate collective excitations in magnetic topological insulators (TIs) and their impact on particle axion detection. In the three-dimensional TI model with the Hubbard term, the effective action of magnons and amplitude modes is formulated by dynamical susceptibility under the antiferromagnetic and ferromagnetic states. One of the amplitude modes is identified as ``axionic'' quasi-particle and its effective coupling to the electromagnetic fields turns out to be enhanced by about four orders of magnitude larger than the previous estimate, which may drastically change the sensitivity of the particle axion search using ``axion'' in magnetic TIs.
|
hep-ph/9212291
|
Carsten Grosse-Knetter
|
R. Boenisch (Universitaet Muenchen), C. Grosse-Knetter and R.
Koegerler (Universitaet Bielefeld)
|
Bounds on Bess Model Parameters from Vector-Boson Production in e+e-
Collisions
|
December 1992, 8 pages LaTeX, 6 figures (not included but available
on request), BI-TP 92/59, LMU-92/15
|
Z.Phys. C59 (1993) 109-117
|
10.1007/BF01555845
| null |
hep-ph
| null |
The BESS model is the Higgs-less alternative to the standard model of
electroweak interaction, based on nonlinearly realized spontaneous symmetry
breaking. Since it is nonrenormalizable, new couplings (not existing in the SM)
are induced at each loop order. On the basis of the one loop induced
vector-boson self-couplings we study the two- and three-vector-boson-production
processes in $e^+e^-$ collisions at $\sqrt{s}=500 GeV$, the expected energy of
the next $ e^+e^-$ linear collider (NLC). Assuming that NLC results will agree
with the SM predictions within given accuracy we identify the bounds for the
free parameters of the BESS model.
|
[
{
"created": "Mon, 21 Dec 1992 21:51:24 GMT",
"version": "v1"
}
] |
2009-10-22
|
[
[
"Boenisch",
"R.",
"",
"Universitaet Muenchen"
],
[
"Grosse-Knetter",
"C.",
"",
"Universitaet Bielefeld"
],
[
"Koegerler",
"R.",
"",
"Universitaet Bielefeld"
]
] |
The BESS model is the Higgs-less alternative to the standard model of electroweak interaction, based on nonlinearly realized spontaneous symmetry breaking. Since it is nonrenormalizable, new couplings (not existing in the SM) are induced at each loop order. On the basis of the one loop induced vector-boson self-couplings we study the two- and three-vector-boson-production processes in $e^+e^-$ collisions at $\sqrt{s}=500 GeV$, the expected energy of the next $ e^+e^-$ linear collider (NLC). Assuming that NLC results will agree with the SM predictions within given accuracy we identify the bounds for the free parameters of the BESS model.
|
hep-ph/9408249
|
Jean Cleymans
|
N. Bili\'c, J. Cleymans, I. Dadi\'c and D. Hislop
|
Gluon Decay as a Mechanism for Strangeness Production in a Quark-Gluon
Plasma
|
10 pages, LATeX, 4 figures available as postscript files from the
authors. report University of Cape Town UCT-TP 213/94
|
Phys.Rev.C52:401-407,1995
|
10.1103/PhysRevC.52.401
| null |
hep-ph
| null |
A calculation of thermal gluon decay shows that this process contributes
significantly to strangeness production in a quark-gluon plasma. Our analysis
does not support recent claims that this is the dominant process. In our
calculations we take into account the resummed form of the transverse and
longitudinal parts of the gluon propagator following the Braaten-Pisarski
method. Our results are subject to the uncertainty concerning the estimate of
the damping rate entering the effective gluon propagator.
|
[
{
"created": "Mon, 8 Aug 1994 12:21:58 GMT",
"version": "v1"
}
] |
2009-09-25
|
[
[
"Bilić",
"N.",
""
],
[
"Cleymans",
"J.",
""
],
[
"Dadić",
"I.",
""
],
[
"Hislop",
"D.",
""
]
] |
A calculation of thermal gluon decay shows that this process contributes significantly to strangeness production in a quark-gluon plasma. Our analysis does not support recent claims that this is the dominant process. In our calculations we take into account the resummed form of the transverse and longitudinal parts of the gluon propagator following the Braaten-Pisarski method. Our results are subject to the uncertainty concerning the estimate of the damping rate entering the effective gluon propagator.
|
0908.3969
|
Radja Boughezal
|
Radja Boughezal
|
QCD-electroweak effects and a new prediction for Higgs production in
gluon fusion process
|
5 pages, 1 figure, 1 table, talk presented at the 2009 Europhysics
Conference on High Energy Physics, 16-22 July 2009, Krakow, Poland
|
PoS EPS-HEP2009:233,2009
| null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We discuss the recent derivation of the three-loop ${\cal O}(\alpha\alpha_s)$
contribution to the Higgs boson production cross section via gluon fusion
arising from diagrams with light quarks, using an effective theory approach. We
show results for the updated prediction of this process accounting for all the
new theoretical calculations and the newest MSTW PDFs.
|
[
{
"created": "Thu, 27 Aug 2009 10:17:40 GMT",
"version": "v1"
}
] |
2014-11-20
|
[
[
"Boughezal",
"Radja",
""
]
] |
We discuss the recent derivation of the three-loop ${\cal O}(\alpha\alpha_s)$ contribution to the Higgs boson production cross section via gluon fusion arising from diagrams with light quarks, using an effective theory approach. We show results for the updated prediction of this process accounting for all the new theoretical calculations and the newest MSTW PDFs.
|
2103.05002
|
Duarte Fontes
|
Duarte Fontes, Maximilian L\"oschner, Jorge C. Rom\~ao, Jo\~ao P.
Silva
|
Leaks of CP violation in the real two-Higgs doublet model
|
12 pages, matches published version
| null |
10.1140/epjc/s10052-021-09332-0
| null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
We discuss the $Z_2$ symmetric two Higgs doublet model with a real soft
breaking term (real 2HDM). We explain in detail why it is not tenable to assume
CP conservation in the scalar sector to keep the dimension two term real, while
CP is violated by the dimension four Yukawa couplings. We propose the
calculation of the infinite tadpole of the (would-be) pseudoscalar neutral
scalar. We construct a simple toy model with the same flaws, where the
unrenormalizable infinity is easier to calculate. We then turn our attention to
the same tadpole in the real 2HDM. We spearhead this effort focusing on
diagrams involving solely bare quantities. This involves hundreds of Feynman
three-loop diagrams that could feed the CP violation from the quark into the
scalar sector, and is only possible with state of the art automatic computation
tools. Remarkably, some intermediate results agree when using three independent
derivations, including the peculiar cancellation of the leading pole divergence
due to a subtle interplay between masses and the Jarlskog invariant, which we
calculate analytically. The calculation is not complete however, since the full
two-loop renormalization of the real 2HDM is not yet available in the
literature. Still, we argue convincingly that there is an irremovable infinity.
|
[
{
"created": "Mon, 8 Mar 2021 19:00:01 GMT",
"version": "v1"
},
{
"created": "Mon, 28 Jun 2021 07:56:50 GMT",
"version": "v2"
}
] |
2021-07-14
|
[
[
"Fontes",
"Duarte",
""
],
[
"Löschner",
"Maximilian",
""
],
[
"Romão",
"Jorge C.",
""
],
[
"Silva",
"João P.",
""
]
] |
We discuss the $Z_2$ symmetric two Higgs doublet model with a real soft breaking term (real 2HDM). We explain in detail why it is not tenable to assume CP conservation in the scalar sector to keep the dimension two term real, while CP is violated by the dimension four Yukawa couplings. We propose the calculation of the infinite tadpole of the (would-be) pseudoscalar neutral scalar. We construct a simple toy model with the same flaws, where the unrenormalizable infinity is easier to calculate. We then turn our attention to the same tadpole in the real 2HDM. We spearhead this effort focusing on diagrams involving solely bare quantities. This involves hundreds of Feynman three-loop diagrams that could feed the CP violation from the quark into the scalar sector, and is only possible with state of the art automatic computation tools. Remarkably, some intermediate results agree when using three independent derivations, including the peculiar cancellation of the leading pole divergence due to a subtle interplay between masses and the Jarlskog invariant, which we calculate analytically. The calculation is not complete however, since the full two-loop renormalization of the real 2HDM is not yet available in the literature. Still, we argue convincingly that there is an irremovable infinity.
|
1110.1835
|
Omar Benhar
|
Omar Benhar
|
Confronting electron- and neutrino-nucleus scattering
|
Invited paper to NUFACT 11, XIIIth International Workshop on Neutrino
Factories, Super Beams and Beta Beams, 1-6 August 2011, CERN and University
of Geneva (submitted to IOP conference series)
|
J. Phys. Conf. Ser. 408, 012042 (2013)
| null | null |
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The analysis of the sample of charged current quasi elastic events collected
by the MiniBooNE Collaboration suggests that the scheme successfully employed
to describe electron-nucleus scattering fails to explain neutrino-nucleus cross
sections. I argue that, due to flux average, the double differential
neutrino-nucleus cross section does not allow for a clearcut determination of
the dominant reaction mechanism. A systematic study of the large body of
electron scattering data may help to identify the processes, other than single
nucleon knockout, contributing to the observed neutrino cross section.
|
[
{
"created": "Sun, 9 Oct 2011 13:27:44 GMT",
"version": "v1"
}
] |
2013-02-18
|
[
[
"Benhar",
"Omar",
""
]
] |
The analysis of the sample of charged current quasi elastic events collected by the MiniBooNE Collaboration suggests that the scheme successfully employed to describe electron-nucleus scattering fails to explain neutrino-nucleus cross sections. I argue that, due to flux average, the double differential neutrino-nucleus cross section does not allow for a clearcut determination of the dominant reaction mechanism. A systematic study of the large body of electron scattering data may help to identify the processes, other than single nucleon knockout, contributing to the observed neutrino cross section.
|
2112.13282
|
Hesham El Faham
|
Hesham El Faham
|
$tWZ$ production at NLO in QCD in the SMEFT
|
7 pages with figures and tables. Proceeding: 14th International
Workshop on Top Quark Physics (videoconference), 13-17 September 2021
| null | null | null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
At NLO in QCD, the $tWZ$ production process interferes with resonant LO
processes, $t\bar{t}Z$ and $t\bar{t}$, and a method to meaningfully disentangle
these overlapping processes needs to be employed. I discuss the diagram-removal
procedure needed to obtain an operative definition of $tWZ$ at NLO accuracy. I
also show the predictions we obtain in the context of the Standard Model and in
the Standard Model Effective Field Theory including the relevant dimension-six
SMEFT operators.
|
[
{
"created": "Sat, 25 Dec 2021 20:25:52 GMT",
"version": "v1"
}
] |
2021-12-28
|
[
[
"Faham",
"Hesham El",
""
]
] |
At NLO in QCD, the $tWZ$ production process interferes with resonant LO processes, $t\bar{t}Z$ and $t\bar{t}$, and a method to meaningfully disentangle these overlapping processes needs to be employed. I discuss the diagram-removal procedure needed to obtain an operative definition of $tWZ$ at NLO accuracy. I also show the predictions we obtain in the context of the Standard Model and in the Standard Model Effective Field Theory including the relevant dimension-six SMEFT operators.
|
1908.04075
|
Sunil Mukhi
|
Sunil Mukhi
|
Renormalisation in Quantum Field Theory
|
126 pages. Based on lecture notes originally taken by Shibasis Roy
and Anirban Karan
| null | null | null |
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
An introductory review, based on a series of lectures delivered at the XXXI
SERC School, Kalyani University, 9--18 January 2017.
|
[
{
"created": "Mon, 12 Aug 2019 10:09:14 GMT",
"version": "v1"
}
] |
2019-08-13
|
[
[
"Mukhi",
"Sunil",
""
]
] |
An introductory review, based on a series of lectures delivered at the XXXI SERC School, Kalyani University, 9--18 January 2017.
|
hep-ph/9710234
| null |
M. Giovannini (DAMTP, Cambridge) and M. E. Shaposhnikov (CERN)
|
Primordial Hypermagnetic Fields and Triangle Anomaly
|
Latex, 53 pages, 8 eps figures
|
Phys.Rev. D57 (1998) 2186-2206
|
10.1103/PhysRevD.57.2186
|
CERN-TH-97-264, DAMTP-97-108
|
hep-ph astro-ph
| null |
The high-temperature plasma above the electroweak scale $\sim 100$ GeV may
have contained a primordial hypercharge magnetic field whose anomalous coupling
to the fermions induces a transformation of the hypermagnetic energy density
into fermionic number. In order to describe this process, we generalize the
ordinary magnetohydrodynamical equations to the anomalous case. We show that a
not completely homogeneous hypermagnetic background induces fermion number
fluctuations, which can be expressed in terms of a generic hypermagnetic field
configuration. We argue that, depending upon the various particle physics
parameters involved in our estimate (electron Yukawa coupling, strength of the
electroweak phase transition) and upon the hypermagnetic energy spectrum,
sizeable matter-antimatter fluctuations can be generated in the plasma. These
fluctuations may modify the predictions of the standard Big Bang
nucleosynthesis (BBN). We derive constraints on the magnetic fields from the
requirement that the homogeneous BBN is not changed. We analyse the influence
of primordial magnetic fields on the electroweak phase transition and show that
some specific configurations of the magnetic field may be converted into net
baryon number at the electroweak scale.
|
[
{
"created": "Fri, 3 Oct 1997 12:45:31 GMT",
"version": "v1"
}
] |
2009-10-30
|
[
[
"Giovannini",
"M.",
"",
"DAMTP, Cambridge"
],
[
"Shaposhnikov",
"M. E.",
"",
"CERN"
]
] |
The high-temperature plasma above the electroweak scale $\sim 100$ GeV may have contained a primordial hypercharge magnetic field whose anomalous coupling to the fermions induces a transformation of the hypermagnetic energy density into fermionic number. In order to describe this process, we generalize the ordinary magnetohydrodynamical equations to the anomalous case. We show that a not completely homogeneous hypermagnetic background induces fermion number fluctuations, which can be expressed in terms of a generic hypermagnetic field configuration. We argue that, depending upon the various particle physics parameters involved in our estimate (electron Yukawa coupling, strength of the electroweak phase transition) and upon the hypermagnetic energy spectrum, sizeable matter-antimatter fluctuations can be generated in the plasma. These fluctuations may modify the predictions of the standard Big Bang nucleosynthesis (BBN). We derive constraints on the magnetic fields from the requirement that the homogeneous BBN is not changed. We analyse the influence of primordial magnetic fields on the electroweak phase transition and show that some specific configurations of the magnetic field may be converted into net baryon number at the electroweak scale.
|
hep-ph/9811294
|
Valentine Zakharov
|
V.I. Zakharov
|
QCD '98: status of the power corrections
|
7 pages, LaTeX using espcrc2.sty; talk given at the Conference QCD'98
(Montpellier, July 1998)
|
Nucl.Phys.Proc.Suppl. 74 (1999) 392-398
|
10.1016/S0920-5632(99)00204-2
|
MPI-PhT/98-82
|
hep-ph
| null |
We review status of the power corrections in QCD. The topics include shape
variables, unconventional 1/Q^2 corrections, tachyonic gluon mass as a fit
parameter to the 1/Q^2 corrections. The selection of the material is determined
mostly by results presented at the Conference QCD'98 (Montpellier, July 1998).
Some background comments are also included.
|
[
{
"created": "Tue, 10 Nov 1998 18:27:59 GMT",
"version": "v1"
}
] |
2009-10-31
|
[
[
"Zakharov",
"V. I.",
""
]
] |
We review status of the power corrections in QCD. The topics include shape variables, unconventional 1/Q^2 corrections, tachyonic gluon mass as a fit parameter to the 1/Q^2 corrections. The selection of the material is determined mostly by results presented at the Conference QCD'98 (Montpellier, July 1998). Some background comments are also included.
|
hep-ph/0503250
|
Lianyi He
|
Pengfei Zhuang
|
Phase Structure of Color Superconductivity
|
Talk presented at Conference on Non-Perturbative Quantum Field
Theory: Lattice and Beyond, Guangzhou, China, Dec.16--18, 2004
|
Mod.Phys.Lett.A22:607-613,2007
|
10.1142/S0217732307023195
| null |
hep-ph
| null |
We investigate color superconductivity and chiral symmetry restoration at
finite temperature and baryon density in the frame of standard two flavor
Nambu--Jona-Lasinio model. We derive the diquark mass in RPA, discuss its
constraint on the coupling constant in the diquark channel, and find a strong
competition between the two phase transitions when the coupling constant is
large enough.
|
[
{
"created": "Thu, 24 Mar 2005 07:11:09 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Zhuang",
"Pengfei",
""
]
] |
We investigate color superconductivity and chiral symmetry restoration at finite temperature and baryon density in the frame of standard two flavor Nambu--Jona-Lasinio model. We derive the diquark mass in RPA, discuss its constraint on the coupling constant in the diquark channel, and find a strong competition between the two phase transitions when the coupling constant is large enough.
|
2207.10111
|
Cem Er\"oncel
|
Cem Er\"oncel, G\'eraldine Servant
|
ALP Dark Matter Mini-Clusters from Kinetic Fragmentation
|
60 pages, 23 figures, minor changes based on the referee comments.
Published version
|
JCAP 01 (2023) 009
|
10.1088/1475-7516/2023/01/009
|
DESY 22-115
|
hep-ph astro-ph.CO
|
http://creativecommons.org/licenses/by/4.0/
|
We show that very compact axion mini-clusters can form in models where
axion-like-particle (ALP) dark matter is produced via the kinetic misalignment
mechanism, which is well-motivated in pre-inflationary $U(1)$ symmetry breaking
scenarios. This is due to ALP fragmentation. We predict denser halos than what
has been obtained so far in the literature from standard misalignment in
post-inflationary $U(1)$ breaking scenarios or from large misalignment. The
main reason is that adiabatic fluctuations are significant at early times;
therefore, even if amplification from parametric resonance effects is moderate,
the final size of ALP fluctuations is larger in kinetic misalignment. We
compare halo mass functions and halo spectra obtained in kinetic misalignment,
large misalignment, and standard misalignment, respectively. Our analysis does
not depend on the specific model realization of the kinetic misalignment
mechanism. We present our results generally as a function of the ALP mass and
the ALP decay constant only. We show that a sizable region of this ALP
parameter space can be tested by future experiments that probe small-scale
structures.
|
[
{
"created": "Wed, 20 Jul 2022 18:00:47 GMT",
"version": "v1"
},
{
"created": "Thu, 2 May 2024 19:31:00 GMT",
"version": "v2"
}
] |
2024-05-06
|
[
[
"Eröncel",
"Cem",
""
],
[
"Servant",
"Géraldine",
""
]
] |
We show that very compact axion mini-clusters can form in models where axion-like-particle (ALP) dark matter is produced via the kinetic misalignment mechanism, which is well-motivated in pre-inflationary $U(1)$ symmetry breaking scenarios. This is due to ALP fragmentation. We predict denser halos than what has been obtained so far in the literature from standard misalignment in post-inflationary $U(1)$ breaking scenarios or from large misalignment. The main reason is that adiabatic fluctuations are significant at early times; therefore, even if amplification from parametric resonance effects is moderate, the final size of ALP fluctuations is larger in kinetic misalignment. We compare halo mass functions and halo spectra obtained in kinetic misalignment, large misalignment, and standard misalignment, respectively. Our analysis does not depend on the specific model realization of the kinetic misalignment mechanism. We present our results generally as a function of the ALP mass and the ALP decay constant only. We show that a sizable region of this ALP parameter space can be tested by future experiments that probe small-scale structures.
|
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