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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
hep-ph/9705477
|
Stephen Pinsky
|
S. Brodsky, H-C Pauli and S. Pinsky
|
Quantum Chromodynamics and Other Field Theories on the Light Cone
|
206 pages Latex, figures included, Submitted to Physics Reports
|
Phys.Rept.301:299-486,1998
|
10.1016/S0370-1573(97)00089-6
|
MPIH-V1-1997, SLAC-PUB-7484
|
hep-ph
| null |
We discuss the light-cone quantization of gauge theories as a calculational
tool for representing hadrons as QCD bound-states of relativistic quarks and
gluons, and also as a novel method for simulating quantum field theory on a
computer. The light-cone Fock state expansion of wavefunctions provides a
precise definition of the parton model and a general calculus for hadronic
matrix elements. We present several new applications of light-cone Fock
methods, including calculations of exclusive weak decays of heavy hadrons, and
intrinsic heavy-quark contributions to structure functions. Discretized
light-cone quantization, is outlined and applied to several gauge theories. We
also discuss the construction of the light-cone Fock basis, the structure of
the light-cone vacuum, and outline the renormalization techniques required for
solving gauge theories within the Hamiltonian formalism on the light cone.
|
[
{
"created": "Thu, 29 May 1997 16:45:16 GMT",
"version": "v1"
}
] |
2009-09-25
|
[
[
"Brodsky",
"S.",
""
],
[
"Pauli",
"H-C",
""
],
[
"Pinsky",
"S.",
""
]
] |
We discuss the light-cone quantization of gauge theories as a calculational tool for representing hadrons as QCD bound-states of relativistic quarks and gluons, and also as a novel method for simulating quantum field theory on a computer. The light-cone Fock state expansion of wavefunctions provides a precise definition of the parton model and a general calculus for hadronic matrix elements. We present several new applications of light-cone Fock methods, including calculations of exclusive weak decays of heavy hadrons, and intrinsic heavy-quark contributions to structure functions. Discretized light-cone quantization, is outlined and applied to several gauge theories. We also discuss the construction of the light-cone Fock basis, the structure of the light-cone vacuum, and outline the renormalization techniques required for solving gauge theories within the Hamiltonian formalism on the light cone.
|
2010.09749
|
Ian Shoemaker
|
James B. Dent, Bhaskar Dutta, Jayden L. Newstead, Ian M. Shoemaker,
and Natalia Tapia Arellano
|
Present and future status of light dark matter models from cosmic-ray
electron upscattering
|
17 pages, 6 figures
|
Phys. Rev. D 103, 095015 (2021)
|
10.1103/PhysRevD.103.095015
| null |
hep-ph astro-ph.CO hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Non-relativistic Dark Matter (DM) can be accelerated by scattering on
high-energy cosmic-ray (CR) electrons. This process leads to a sub-population
of relativistic or semi-relativistic DM which extends the experimental reach
for direct detection in the sub-GeV mass regime. In this paper we examine the
current and future potential of this mechanism for constraining models of light
dark matter. In particular, we find that Super-Kamiokande and XENON1T data can
already provide leading constraints on the flux of dark matter that has been
accelerated to high energies from cosmic ray electrons. We also examine future
projected sensitivities for DUNE and Hyper-K, and contrary to previous
findings, conclude that DUNE will be able supersede Super-K bounds on
cosmic-ray upscattered DM for a variety of DM models.
|
[
{
"created": "Mon, 19 Oct 2020 18:00:34 GMT",
"version": "v1"
}
] |
2021-05-26
|
[
[
"Dent",
"James B.",
""
],
[
"Dutta",
"Bhaskar",
""
],
[
"Newstead",
"Jayden L.",
""
],
[
"Shoemaker",
"Ian M.",
""
],
[
"Arellano",
"Natalia Tapia",
""
]
] |
Non-relativistic Dark Matter (DM) can be accelerated by scattering on high-energy cosmic-ray (CR) electrons. This process leads to a sub-population of relativistic or semi-relativistic DM which extends the experimental reach for direct detection in the sub-GeV mass regime. In this paper we examine the current and future potential of this mechanism for constraining models of light dark matter. In particular, we find that Super-Kamiokande and XENON1T data can already provide leading constraints on the flux of dark matter that has been accelerated to high energies from cosmic ray electrons. We also examine future projected sensitivities for DUNE and Hyper-K, and contrary to previous findings, conclude that DUNE will be able supersede Super-K bounds on cosmic-ray upscattered DM for a variety of DM models.
|
1602.05137
|
Carlos E. Yaguna
|
Michael Klasen, David R. Lamprea, Carlos E. Yaguna
|
Lepton flavor violation and scalar dark matter in a radiative model of
neutrino masses
|
20 pages
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider a simple extension of the Standard Model that can account for the
dark matter and explain the existence of neutrino masses. The model includes a
vector-like doublet of SU(2), a singlet fermion, and two scalar singlets, all
of them odd under a new Z$_2$ symmetry. Neutrino masses are generated
radiatively by one-loop processes involving the new fields, while the dark
matter candidate is the lightest neutral particle among them. We focus
specifically on the case where the dark matter particle is one of the scalars
and its relic density is determined by its Yukawa interactions. The
phenomenology of this setup, including neutrino masses, dark matter and lepton
flavor violation, is analyzed in some detail. We find that the dark matter mass
must be below $500$ GeV to satisfy the relic density constraint. Lepton flavor
violating processes are shown to provide the most promising way to test this
scenario. Future $\mu\to 3e$ and $\mu$-$e$ conversion experiments, in
particular, have the potential to probe the entire viable parameter space of
this model.
|
[
{
"created": "Tue, 16 Feb 2016 18:51:23 GMT",
"version": "v1"
}
] |
2016-02-17
|
[
[
"Klasen",
"Michael",
""
],
[
"Lamprea",
"David R.",
""
],
[
"Yaguna",
"Carlos E.",
""
]
] |
We consider a simple extension of the Standard Model that can account for the dark matter and explain the existence of neutrino masses. The model includes a vector-like doublet of SU(2), a singlet fermion, and two scalar singlets, all of them odd under a new Z$_2$ symmetry. Neutrino masses are generated radiatively by one-loop processes involving the new fields, while the dark matter candidate is the lightest neutral particle among them. We focus specifically on the case where the dark matter particle is one of the scalars and its relic density is determined by its Yukawa interactions. The phenomenology of this setup, including neutrino masses, dark matter and lepton flavor violation, is analyzed in some detail. We find that the dark matter mass must be below $500$ GeV to satisfy the relic density constraint. Lepton flavor violating processes are shown to provide the most promising way to test this scenario. Future $\mu\to 3e$ and $\mu$-$e$ conversion experiments, in particular, have the potential to probe the entire viable parameter space of this model.
|
2011.01005
|
Marcin Chrzaszcz Dr
|
Marcin Chrzaszcz, Marco Drewes, Jan Hajer
|
HECATE: A long lived particle detector concept for the FCC-ee or CEPC
|
5 pages, 1 figure
|
The European Physical Journal C volume 81, Article number: 546
(2021)
|
10.1140/epjc/s10052-021-09253-y
|
CP3-20-48
|
hep-ph hep-ex physics.ins-det
|
http://creativecommons.org/licenses/by/4.0/
|
The next generation of circular high energy collider is expected to be a
lepton collider, FCC-ee at CERN or CEPC in China. However, the civil
engineering concepts foresee to equip these colliders with bigger detector
caverns than one would need for a lepton collider, so that they can be used for
a hadron collider that may be installed in the same tunnel without further
civil engineering. This opens up the possibility to install extra
instrumentation at the cavern walls to search for new long-lived particles at
the lepton collider. We use the example of heavy neutral leptons to show that
such an installation could improve the sensitivity to the squared mixing
parameter by almost half an order of magnitude.
|
[
{
"created": "Mon, 2 Nov 2020 14:23:45 GMT",
"version": "v1"
},
{
"created": "Tue, 10 Nov 2020 14:07:40 GMT",
"version": "v2"
},
{
"created": "Tue, 29 Jun 2021 09:05:15 GMT",
"version": "v3"
}
] |
2021-06-30
|
[
[
"Chrzaszcz",
"Marcin",
""
],
[
"Drewes",
"Marco",
""
],
[
"Hajer",
"Jan",
""
]
] |
The next generation of circular high energy collider is expected to be a lepton collider, FCC-ee at CERN or CEPC in China. However, the civil engineering concepts foresee to equip these colliders with bigger detector caverns than one would need for a lepton collider, so that they can be used for a hadron collider that may be installed in the same tunnel without further civil engineering. This opens up the possibility to install extra instrumentation at the cavern walls to search for new long-lived particles at the lepton collider. We use the example of heavy neutral leptons to show that such an installation could improve the sensitivity to the squared mixing parameter by almost half an order of magnitude.
|
1103.1697
|
JoAnne Hewett
|
John A. Conley, James S. Gainer, JoAnne L. Hewett, My Phuong Le,
Thomas G. Rizzo
|
Supersymmetry Without Prejudice at the 7 TeV LHC
|
51 pages, 26 figures
| null | null |
SLAC-PUB-14382, ANL-HEP-PR-11-13, NUHEP-TH/11-014, BONN-TH-2011-05
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We investigate the model independent nature of the Supersymmetry search
strategies at the 7 TeV LHC. To this end, we study the
missing-transverse-energy-based searches developed by the ATLAS Collaboration
that were essentially designed for mSUGRA. We simulate the signals for ~71k
models in the 19-dimensional parameter space of the pMSSM. These models have
been found to satisfy existing experimental and theoretical constraints and
provide insight into general features of the MSSM without reference to a
particular SUSY breaking scenario or any other assumptions at the GUT scale.
Using backgrounds generated by ATLAS, we find that imprecise knowledge of these
estimated backgrounds is a limiting factor in the potential discovery of these
models and that some channels become systematics-limited at larger
luminosities. As this systematic error is varied between 20-100%, roughly half
to 90% of this model sample is observable with significance S>5 for 1 fb^{-1}
of integrated luminosity. We then examine the model characteristics for the
cases which cannot be discovered and find several contributing factors. We find
that a blanket statement that squarks and gluinos are excluded with masses
below a specific value cannot be made. We next explore possible modifications
to the kinematic cuts in these analyses that may improve the pMSSM model
coverage. Lastly, we examine the implications of a null search at the 7 TeV LHC
in terms of the degree of fine-tuning that would be present in this model set
and for sparticle production at the 500 GeV and 1 TeV Linear Collider.
|
[
{
"created": "Wed, 9 Mar 2011 04:08:30 GMT",
"version": "v1"
}
] |
2011-03-10
|
[
[
"Conley",
"John A.",
""
],
[
"Gainer",
"James S.",
""
],
[
"Hewett",
"JoAnne L.",
""
],
[
"Le",
"My Phuong",
""
],
[
"Rizzo",
"Thomas G.",
""
]
] |
We investigate the model independent nature of the Supersymmetry search strategies at the 7 TeV LHC. To this end, we study the missing-transverse-energy-based searches developed by the ATLAS Collaboration that were essentially designed for mSUGRA. We simulate the signals for ~71k models in the 19-dimensional parameter space of the pMSSM. These models have been found to satisfy existing experimental and theoretical constraints and provide insight into general features of the MSSM without reference to a particular SUSY breaking scenario or any other assumptions at the GUT scale. Using backgrounds generated by ATLAS, we find that imprecise knowledge of these estimated backgrounds is a limiting factor in the potential discovery of these models and that some channels become systematics-limited at larger luminosities. As this systematic error is varied between 20-100%, roughly half to 90% of this model sample is observable with significance S>5 for 1 fb^{-1} of integrated luminosity. We then examine the model characteristics for the cases which cannot be discovered and find several contributing factors. We find that a blanket statement that squarks and gluinos are excluded with masses below a specific value cannot be made. We next explore possible modifications to the kinematic cuts in these analyses that may improve the pMSSM model coverage. Lastly, we examine the implications of a null search at the 7 TeV LHC in terms of the degree of fine-tuning that would be present in this model set and for sparticle production at the 500 GeV and 1 TeV Linear Collider.
|
1304.0365
|
Yu. A. Simonov
|
Yu. A. Simonov (Institute of Theoretical and Experimental Physics,
Moscow, Russia)
|
Spin interactions in mesons in strong magnetic field
|
26 pages
|
Phys. Rev. D 88, 053004 (2013)
|
10.1103/PhysRevD.88.053004
| null |
hep-ph hep-lat
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Spin interactions in relativistic quark-antiquark system in magnetic field is
considered in the framework of the relativistic Hamiltonian, derived from the
QCD path integral. The formalism allows to separate spin-dependent terms from
the basic spin-independent interaction, contained in the Wilson loop, and
producing confining and gluon exchange interaction. As a result one obtains
relativistic spin-spin interaction $V_{ss}$, generalizing its nonrelativistic
analog. It is shown, that in large magnetic field $eB, V_{ss}$ modifies and
produces hyperfine shifts which grow linearly with $eB$ and preclude the use of
perturbation theory. We also show, that tensor forces for $eB \neq 0$ are
active in all meson states, but do not grow with $eB$
|
[
{
"created": "Mon, 1 Apr 2013 14:33:00 GMT",
"version": "v1"
},
{
"created": "Thu, 25 Apr 2013 11:04:16 GMT",
"version": "v2"
}
] |
2014-01-29
|
[
[
"Simonov",
"Yu. A.",
"",
"Institute of Theoretical and Experimental Physics,\n Moscow, Russia"
]
] |
Spin interactions in relativistic quark-antiquark system in magnetic field is considered in the framework of the relativistic Hamiltonian, derived from the QCD path integral. The formalism allows to separate spin-dependent terms from the basic spin-independent interaction, contained in the Wilson loop, and producing confining and gluon exchange interaction. As a result one obtains relativistic spin-spin interaction $V_{ss}$, generalizing its nonrelativistic analog. It is shown, that in large magnetic field $eB, V_{ss}$ modifies and produces hyperfine shifts which grow linearly with $eB$ and preclude the use of perturbation theory. We also show, that tensor forces for $eB \neq 0$ are active in all meson states, but do not grow with $eB$
|
0712.4111
|
Fuqiang Xu
|
Fuqiang Xu, Jin Min Yang
|
An Extension for Direct Gauge Mediation of Metastable Supersymmetry
Breaking
|
version in Europhys. Lett
|
Europhys.Lett.85:61001,2009
|
10.1209/0295-5075/85/61001
| null |
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study the direct mediation of metastable supersymmetry breaking by a
\Phi^2-deformation to the ISS model and extend it by splitting both Tr\Phi and
Tr\Phi^2 terms in the superpotential and gauging the flavor symmetry. We find
that with such an extension the enough long-lived metastable vacua can be
obtained and the proper gaugino masses can be generated. Also, this allows for
constructing a kind of models which can avoid the Landau pole problem.
Especially, in our metastable vacua there exist a large region for the
parameter m_3 which can satisfy the phenomenology requirements and allow for a
low SUSY breaking scale (\sim 100 TeV).
|
[
{
"created": "Wed, 26 Dec 2007 08:49:08 GMT",
"version": "v1"
},
{
"created": "Fri, 28 Dec 2007 03:31:31 GMT",
"version": "v2"
},
{
"created": "Fri, 24 Oct 2008 14:15:57 GMT",
"version": "v3"
},
{
"created": "Fri, 3 Apr 2009 09:33:44 GMT",
"version": "v4"
}
] |
2009-05-29
|
[
[
"Xu",
"Fuqiang",
""
],
[
"Yang",
"Jin Min",
""
]
] |
We study the direct mediation of metastable supersymmetry breaking by a \Phi^2-deformation to the ISS model and extend it by splitting both Tr\Phi and Tr\Phi^2 terms in the superpotential and gauging the flavor symmetry. We find that with such an extension the enough long-lived metastable vacua can be obtained and the proper gaugino masses can be generated. Also, this allows for constructing a kind of models which can avoid the Landau pole problem. Especially, in our metastable vacua there exist a large region for the parameter m_3 which can satisfy the phenomenology requirements and allow for a low SUSY breaking scale (\sim 100 TeV).
|
0905.1201
|
Mihoko Nojiri
|
Johan Alwall, Kenji Hiramatsu, Mihoko M. Nojiri, and Yasuhiro Shimizu
|
Novel reconstruction technique for New Physics processes with initial
state radiation
|
4 pages, 5 figures
|
Phys.Rev.Lett.103:151802,2009
|
10.1103/PhysRevLett.103.151802
|
KEK-TH 1312
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
At hadron colliders, the production of heavy new particles is associated with
additional quarks and gluons with significant transeverse momentum. The
additional jets complicates the reconstruction of new particle masses. Taking
gluino pair production and decay at the Large Hadron Collider as an example, we
develop a novel technique to reduce these effects, and to reconstruct a clear
kinematical endpoint for the gluino decay products.
|
[
{
"created": "Fri, 8 May 2009 08:27:00 GMT",
"version": "v1"
}
] |
2009-10-29
|
[
[
"Alwall",
"Johan",
""
],
[
"Hiramatsu",
"Kenji",
""
],
[
"Nojiri",
"Mihoko M.",
""
],
[
"Shimizu",
"Yasuhiro",
""
]
] |
At hadron colliders, the production of heavy new particles is associated with additional quarks and gluons with significant transeverse momentum. The additional jets complicates the reconstruction of new particle masses. Taking gluino pair production and decay at the Large Hadron Collider as an example, we develop a novel technique to reduce these effects, and to reconstruct a clear kinematical endpoint for the gluino decay products.
|
hep-ph/9806407
|
Klaus Werner
|
H.J. Drescher, M. Hladik, S. Ostapchenko, K. Werner
|
Hadronic Interactions for High Energy Cosmic Ray Air Showers
|
4 pages, no figures; Proc. of "Physics at Cosmic Accelerators", Burg
Liebenzell, Germany, April 1-5, 1998
| null | null |
SUBATECH 98-08
|
hep-ph
| null |
Understanding hadronic interactions at high energies represents a very
important ingredient for modeling high energy cosmic ray air showers. In this
paper, we present a new approach to simulate hadronic interactions, including
hadron-hadron, hadron-nucleus, and nucleus-nucleus scattering, in the energy
range roughly between 10^11 and 10^17 eV. Such collisions are very complex,
being composed of many components, and therefore some strategy is needed to
construct a reliable model. The central point of our approach is the
hypothesis, that the behavior of high energy interactions is universal
(universality hypothesis). So, for example, the hadronization of partons in
nuclear interactions follows the same rules as the one in electron-positron
annihilation ; the radiation of off-shell partons in hadronic collisions is
based on the same principles as the one in deep inelastic scattering. We
construct a model for hadronic interactions in a modular fashion. The
individual modules, based on the universality hypothesis, are identified as
building blocks for more elementary interactions (like e^+ e^-, lepton-proton),
and can therefore be studied in a much simpler context. With these building
blocks under control, we can provide a quite reliable model for
nucleus-nucleus, hadron-nucleus and hadron-hadron scattering, providing in
particular very useful tests for the complicated numerical procedures using
Monte Carlo techniques.
|
[
{
"created": "Thu, 18 Jun 1998 17:08:35 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Drescher",
"H. J.",
""
],
[
"Hladik",
"M.",
""
],
[
"Ostapchenko",
"S.",
""
],
[
"Werner",
"K.",
""
]
] |
Understanding hadronic interactions at high energies represents a very important ingredient for modeling high energy cosmic ray air showers. In this paper, we present a new approach to simulate hadronic interactions, including hadron-hadron, hadron-nucleus, and nucleus-nucleus scattering, in the energy range roughly between 10^11 and 10^17 eV. Such collisions are very complex, being composed of many components, and therefore some strategy is needed to construct a reliable model. The central point of our approach is the hypothesis, that the behavior of high energy interactions is universal (universality hypothesis). So, for example, the hadronization of partons in nuclear interactions follows the same rules as the one in electron-positron annihilation ; the radiation of off-shell partons in hadronic collisions is based on the same principles as the one in deep inelastic scattering. We construct a model for hadronic interactions in a modular fashion. The individual modules, based on the universality hypothesis, are identified as building blocks for more elementary interactions (like e^+ e^-, lepton-proton), and can therefore be studied in a much simpler context. With these building blocks under control, we can provide a quite reliable model for nucleus-nucleus, hadron-nucleus and hadron-hadron scattering, providing in particular very useful tests for the complicated numerical procedures using Monte Carlo techniques.
|
hep-ph/9610426
|
Frank Close
|
Frank Close
|
The current picture of Glueballs
|
Rapporteur talk at LEAP96, Dinkelsbuhl, Germany; 27-31 Aug 1996
(based on work with C.Amsler, with G.Farrar and Z.P.Li, and with M.Teper)
|
Nucl.Phys.Proc.Suppl. 56A (1997) 248-255
|
10.1016/S0920-5632(97)00283-1
|
RAL-96-085
|
hep-ph
| null |
Some recent developments in the phenomenology of the lightest scalar glueball
are summarised. Tools for determining the gluonic content of a resonance of
known mass, width and $J^{PC}$ from its branching fraction in radiative
quarkonium decays and production cross section in $\gamma \gamma$ collisions
are presented. Two $q\bar{q} - G$ mixing schemes for $J^{PC} = 0^{++}$,
inspired by the lattice, are shown to lead to similar phenomenology that may be
tested at BEPC and in $\gamma \gamma$ production at LEP2.
|
[
{
"created": "Mon, 21 Oct 1996 09:03:03 GMT",
"version": "v1"
}
] |
2009-10-30
|
[
[
"Close",
"Frank",
""
]
] |
Some recent developments in the phenomenology of the lightest scalar glueball are summarised. Tools for determining the gluonic content of a resonance of known mass, width and $J^{PC}$ from its branching fraction in radiative quarkonium decays and production cross section in $\gamma \gamma$ collisions are presented. Two $q\bar{q} - G$ mixing schemes for $J^{PC} = 0^{++}$, inspired by the lattice, are shown to lead to similar phenomenology that may be tested at BEPC and in $\gamma \gamma$ production at LEP2.
|
1708.06455
|
Ryo Takahashi
|
Kunio Kaneta, Osamu Seto, Ryo Takahashi
|
Very low scale Coleman-Weinberg inflation with non-minimal coupling
|
14 pages, 9 figures, published version
|
Phys. Rev. D 97, 063004 (2018)
|
10.1103/PhysRevD.97.063004
|
CTPU-17-32, EPHOU-17-012
|
hep-ph astro-ph.CO hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study viable small-field Coleman-Weinberg (CW) inflation models with the
help of non-minimal coupling to gravity. The simplest small-field CW inflation
model (with a low-scale potential minimum) is incompatible with the
cosmological constraint on the scalar spectral index. However, there are
possibilities to make the model realistic. First, we revisit the CW inflation
model supplemented with a linear potential term. We next consider the CW
inflation model with a logarithmic non-minimal coupling and illustrate that the
model can open a new viable parameter space that includes the model with a
linear potential term. We also show parameter spaces where the Hubble scale
during the inflation can be as small as $10^{-4} $ GeV, $1$ GeV, $10^4 $ GeV,
and $10^8$ GeV for the number of $e$-folds of $40,~45,~50$, and $55$,
respectively, with other cosmological constraints being satisfied.
|
[
{
"created": "Tue, 22 Aug 2017 00:24:23 GMT",
"version": "v1"
},
{
"created": "Tue, 27 Mar 2018 04:21:09 GMT",
"version": "v2"
}
] |
2018-03-28
|
[
[
"Kaneta",
"Kunio",
""
],
[
"Seto",
"Osamu",
""
],
[
"Takahashi",
"Ryo",
""
]
] |
We study viable small-field Coleman-Weinberg (CW) inflation models with the help of non-minimal coupling to gravity. The simplest small-field CW inflation model (with a low-scale potential minimum) is incompatible with the cosmological constraint on the scalar spectral index. However, there are possibilities to make the model realistic. First, we revisit the CW inflation model supplemented with a linear potential term. We next consider the CW inflation model with a logarithmic non-minimal coupling and illustrate that the model can open a new viable parameter space that includes the model with a linear potential term. We also show parameter spaces where the Hubble scale during the inflation can be as small as $10^{-4} $ GeV, $1$ GeV, $10^4 $ GeV, and $10^8$ GeV for the number of $e$-folds of $40,~45,~50$, and $55$, respectively, with other cosmological constraints being satisfied.
|
1908.02852
|
Ahmed Hammad
|
Stefan Antusch, Oliver Fischer, A. Hammad
|
Lepton-Trijet and Displaced Vertex Searches for Heavy Neutrinos at
Future Electron-Proton Colliders
|
16 pages, 7 figures, 1 table
| null |
10.1007/JHEP03(2020)110
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Electron proton (ep) colliders could provide particle collisions at TeV
energies with large data rates while maintaining the clean and pile~up-free
environment of lepton colliders, which makes them very attractive for heavy
neutrino searches. Heavy (mainly sterile) neutrinos with masses around the
electroweak scale are proposed in low scale seesaw models for neutrino mass
generation. In this paper, we analyse two of the most promising signatures of
heavy neutrinos at ep colliders, the lepton-flavour violating (LFV)
lepton-trijet signature and the displaced vertex signature. In the considered
benchmark model, we find that for heavy neutrino masses around a few hundred
GeV, the LFV lepton-trijet signature at ep colliders yields the best
sensitivity of all currently discussed heavy neutrino signatures (analysed at
the reconstructed level) up to now.
|
[
{
"created": "Wed, 7 Aug 2019 21:50:48 GMT",
"version": "v1"
}
] |
2020-04-22
|
[
[
"Antusch",
"Stefan",
""
],
[
"Fischer",
"Oliver",
""
],
[
"Hammad",
"A.",
""
]
] |
Electron proton (ep) colliders could provide particle collisions at TeV energies with large data rates while maintaining the clean and pile~up-free environment of lepton colliders, which makes them very attractive for heavy neutrino searches. Heavy (mainly sterile) neutrinos with masses around the electroweak scale are proposed in low scale seesaw models for neutrino mass generation. In this paper, we analyse two of the most promising signatures of heavy neutrinos at ep colliders, the lepton-flavour violating (LFV) lepton-trijet signature and the displaced vertex signature. In the considered benchmark model, we find that for heavy neutrino masses around a few hundred GeV, the LFV lepton-trijet signature at ep colliders yields the best sensitivity of all currently discussed heavy neutrino signatures (analysed at the reconstructed level) up to now.
|
0705.0431
|
Ayres Freitas
|
C. Balazs, M. Carena, A. Freitas, C.E.M. Wagner
|
Phenomenology of the nMSSM from colliders to cosmology
|
44 pp, 10 figures; Fig.9 replaced; discussion on CP violation
extended and references added; few minor additions in text about details of
the cuts
|
JHEP 0706:066,2007
|
10.1088/1126-6708/2007/06/066
|
ANL-HEP-PR-07-22; EFI-07-09; FERMILAB-PUB-07-080-T; ZU-TH 11/07
|
hep-ph
| null |
Low energy supersymmetric models provide a solution to the hierarchy problem
and also have the necessary ingredients to solve two of the most outstanding
issues in cosmology: the origin of dark matter and baryonic matter. One of the
most attractive features of this framework is that the relevant physical
processes are related to interactions at the weak scale and therefore may be
tested in collider experiments in the near future. This is true for the Minimal
Supersymmetric Standard Model (MSSM) as well as for its extension with the
addition of one singlet chiral superfield, the so-called nMSSM. It has been
recently shown that within the nMSSM an elegant solution to both the problem of
baryogenesis and dark matter may be found, that relies mostly on the mixing of
the singlet sector with the Higgs sector of the theory. In this work we review
the nMSSM model constraints from cosmology and present the associated collider
phenomenology at the LHC and the ILC. We show that the ILC will efficiently
probe the neutralino, chargino and Higgs sectors, allowing to confront
cosmological observations with computations based on collider measurements. We
also investigate the prospects for a direct detection of dark matter and the
constraints imposed by the current bounds of the electron electric dipole
moment in this model.
|
[
{
"created": "Thu, 3 May 2007 10:28:17 GMT",
"version": "v1"
},
{
"created": "Mon, 28 May 2007 10:39:34 GMT",
"version": "v2"
},
{
"created": "Thu, 14 Feb 2008 15:20:35 GMT",
"version": "v3"
}
] |
2009-11-13
|
[
[
"Balazs",
"C.",
""
],
[
"Carena",
"M.",
""
],
[
"Freitas",
"A.",
""
],
[
"Wagner",
"C. E. M.",
""
]
] |
Low energy supersymmetric models provide a solution to the hierarchy problem and also have the necessary ingredients to solve two of the most outstanding issues in cosmology: the origin of dark matter and baryonic matter. One of the most attractive features of this framework is that the relevant physical processes are related to interactions at the weak scale and therefore may be tested in collider experiments in the near future. This is true for the Minimal Supersymmetric Standard Model (MSSM) as well as for its extension with the addition of one singlet chiral superfield, the so-called nMSSM. It has been recently shown that within the nMSSM an elegant solution to both the problem of baryogenesis and dark matter may be found, that relies mostly on the mixing of the singlet sector with the Higgs sector of the theory. In this work we review the nMSSM model constraints from cosmology and present the associated collider phenomenology at the LHC and the ILC. We show that the ILC will efficiently probe the neutralino, chargino and Higgs sectors, allowing to confront cosmological observations with computations based on collider measurements. We also investigate the prospects for a direct detection of dark matter and the constraints imposed by the current bounds of the electron electric dipole moment in this model.
|
1405.6873
|
Lev Leinson
|
Lev B. Leinson
|
Axion mass limit from observations of the neutron star in Cassiopeia A
|
10 pages, 1 figure
|
J. Cosmol. Astropart. Phys. 08 (2014) 031
|
10.1088/1475-7516/2014/08/031
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Direct Chandra observations of a surface temperature of isolated neutron star
in Cassiopeia A (Cas A NS) and its cooling scenario which has been recently
simultaneously suggested by several scientific teams put stringent constraints
on poorly known properties of the superfluid neutron star core. It was found
also that the thermal energy losses from Cas A NS are approximately twice more
intensive than it can be explained by the neutrino emission. We use these
unique data and well-defined cooling scenario to estimate the strength of KSVZ
axion interactions with neutrons. We speculate that enlarged energy losses
occur owing to emission of axions from superfluid core of the neutron star. If
the axion and neutrino losses are comparable we find $c_{n}^{2}m_{a}^{2}\sim
5.7\times 10^{-6}\,\text{eV}^2$, where $m_{a}$ is the axion mass, and $c_{n}$
is the effective Peccei-Quinn charge of the neutron. (Given the QCD
uncertainties of the hadronic axion models, the dimensionless constant $c_{n}$
could range from $-0.05$ to $ 0.14$.)
|
[
{
"created": "Tue, 27 May 2014 11:30:51 GMT",
"version": "v1"
},
{
"created": "Sat, 26 Jul 2014 14:25:55 GMT",
"version": "v2"
},
{
"created": "Thu, 14 Aug 2014 11:23:14 GMT",
"version": "v3"
}
] |
2014-08-15
|
[
[
"Leinson",
"Lev B.",
""
]
] |
Direct Chandra observations of a surface temperature of isolated neutron star in Cassiopeia A (Cas A NS) and its cooling scenario which has been recently simultaneously suggested by several scientific teams put stringent constraints on poorly known properties of the superfluid neutron star core. It was found also that the thermal energy losses from Cas A NS are approximately twice more intensive than it can be explained by the neutrino emission. We use these unique data and well-defined cooling scenario to estimate the strength of KSVZ axion interactions with neutrons. We speculate that enlarged energy losses occur owing to emission of axions from superfluid core of the neutron star. If the axion and neutrino losses are comparable we find $c_{n}^{2}m_{a}^{2}\sim 5.7\times 10^{-6}\,\text{eV}^2$, where $m_{a}$ is the axion mass, and $c_{n}$ is the effective Peccei-Quinn charge of the neutron. (Given the QCD uncertainties of the hadronic axion models, the dimensionless constant $c_{n}$ could range from $-0.05$ to $ 0.14$.)
|
hep-ph/0110321
|
Igor N. Mishustin
|
I. N. Mishustin (1,2,3), J. I. Kapusta (1) ((1) University of
Minnesota, (2) Niels Bohr Institute, Copenhagen, (3) Kurchatov Institute,
Moscow)
|
Collective Deceleration of Ultrarelativistic Nuclei and Creation of
Quark-Gluon Plasma
|
11 pages in revtex, 2 eps figures
|
Phys.Rev.Lett. 88 (2002) 112501
|
10.1103/PhysRevLett.88.112501
|
NUC-MINN-14/01-T
|
hep-ph
| null |
We propose a unified space-time picture of baryon stopping and quark-gluon
plasma creation in ultrarelativistic heavy-ion collisions. It is assumed that
the highly Lorentz contracted nuclei are decelerated by the coherent color
field which is formed between them after they pass through each other. This
process continues until the field is neutralized by the Schwinger mechanism.
Conservation of energy and momentum allow us to calculate the energy losses of
the nuclear slabs and the initial energy density of the quark-gluon plasma.
|
[
{
"created": "Thu, 25 Oct 2001 19:06:39 GMT",
"version": "v1"
}
] |
2009-11-07
|
[
[
"Mishustin",
"I. N.",
""
],
[
"Kapusta",
"J. I.",
""
]
] |
We propose a unified space-time picture of baryon stopping and quark-gluon plasma creation in ultrarelativistic heavy-ion collisions. It is assumed that the highly Lorentz contracted nuclei are decelerated by the coherent color field which is formed between them after they pass through each other. This process continues until the field is neutralized by the Schwinger mechanism. Conservation of energy and momentum allow us to calculate the energy losses of the nuclear slabs and the initial energy density of the quark-gluon plasma.
|
hep-ph/9312246
|
van der Bij
|
J. J. van der Bij
|
The Hill Theorem
|
6 pages, Freiburg-THEP 93/28
| null | null | null |
hep-ph
| null |
It is studied how strong interactions in the Higgs sector can lead to
deviations in vector boson selfcouplings. Normally such effects are small due
to Veltman's screening theorem. It is shown that strong interactions are
possible, if there is a hierarchy of strong interactions in the Higgs sector.
This is called Hill's theorem.
|
[
{
"created": "Wed, 8 Dec 1993 19:44:41 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"van der Bij",
"J. J.",
""
]
] |
It is studied how strong interactions in the Higgs sector can lead to deviations in vector boson selfcouplings. Normally such effects are small due to Veltman's screening theorem. It is shown that strong interactions are possible, if there is a hierarchy of strong interactions in the Higgs sector. This is called Hill's theorem.
|
hep-ph/9411294
|
Lyndon Alvero
|
Lyndon Alvero (ITP, SUNY at Stony Brook; Physics Dept, PSU) and Harry
Contopanagos (Argonne National Lab.)
|
The Dilepton-Production Cross Section in Principal Value Resummation
|
23 pages, LaTeX. 15 figures. Replaced with final version that will
appear in Nucl. Phys. B. Changes consist of the inclusion of an additional
term in the resummed hard part and revised sets of tables and figures
|
Nucl.Phys. B456 (1995) 497-530
|
10.1016/0550-3213(95)00102-7
|
ITP-SB-94-41, ANL-HEP-PR-94-59
|
hep-ph
| null |
Using a recent calculation of the perturbative hard part for dilepton
production that sums large threshold corrections to all orders in perturbative
QCD, we compute the corresponding cross sections. The hard part has been
evaluated using principal value resummation and contains all singular
momentum-dependent corrections. We also include a resummation of large Sudakov
terms, which are independent of parton momenta. We give predictions for the
dilepton-mass distribution, the rapidity distribution and the
rapidity-integrated $K$-factor at fixed-target energies and compare with
various experimental results in several kinematic regimes. We find that
principal value resummation produces cross sections that are finite and
well-behaved. For both protons and anti-protons on fixed targets, the resummed
cross sections are, in general, in excellent agreement with the data.
|
[
{
"created": "Mon, 14 Nov 1994 23:07:38 GMT",
"version": "v1"
},
{
"created": "Wed, 18 Oct 1995 21:03:44 GMT",
"version": "v2"
}
] |
2009-10-28
|
[
[
"Alvero",
"Lyndon",
"",
"ITP, SUNY at Stony Brook; Physics Dept, PSU"
],
[
"Contopanagos",
"Harry",
"",
"Argonne National Lab."
]
] |
Using a recent calculation of the perturbative hard part for dilepton production that sums large threshold corrections to all orders in perturbative QCD, we compute the corresponding cross sections. The hard part has been evaluated using principal value resummation and contains all singular momentum-dependent corrections. We also include a resummation of large Sudakov terms, which are independent of parton momenta. We give predictions for the dilepton-mass distribution, the rapidity distribution and the rapidity-integrated $K$-factor at fixed-target energies and compare with various experimental results in several kinematic regimes. We find that principal value resummation produces cross sections that are finite and well-behaved. For both protons and anti-protons on fixed targets, the resummed cross sections are, in general, in excellent agreement with the data.
|
0806.4673
|
Jihn E. Kim
|
Jihn E. Kim
|
String Compactification and Unification of Forces
|
18 pages with 11 figures. Talk presented at "GUT Worksop",
Ritsumeikan Univ., Japan, 17-19 Dec. 2007
|
AIP Conf.Proc.1015:107-124,2008
|
10.1063/1.2939044
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
I review our recent attempts toward obtaining the MSSM from string orbifold
compactification. The required constraints are the existence of three families
and R parity, vectorlike exotics, one pair of Higgs doublets, and the SU(5)$'$
hidden sector for dynamical breaking of SUSY toward a GMSB scenario. We also
comment on the threshold correction which are influenced by a power law
evolution of gauge couplings through the KK radius in non-prime orbifolds and
can be used to fit the couplings.
|
[
{
"created": "Sat, 28 Jun 2008 08:46:50 GMT",
"version": "v1"
}
] |
2009-03-12
|
[
[
"Kim",
"Jihn E.",
""
]
] |
I review our recent attempts toward obtaining the MSSM from string orbifold compactification. The required constraints are the existence of three families and R parity, vectorlike exotics, one pair of Higgs doublets, and the SU(5)$'$ hidden sector for dynamical breaking of SUSY toward a GMSB scenario. We also comment on the threshold correction which are influenced by a power law evolution of gauge couplings through the KK radius in non-prime orbifolds and can be used to fit the couplings.
|
2101.02492
|
Wei Liao
|
Haojie Shen, Yu Cheng, Wei Liao
|
Gauge invariance of the vector meson mass in the Coleman-Weinberg model
|
18 pages, 4 figures, version published in PRD
|
Phys. Rev. D 103, 076016 (2021)
|
10.1103/PhysRevD.103.076016
| null |
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We revisit the problem of the gauge invariance in the Coleman-Weinberg model
in which a $U(1)$ gauge symmetry is driven spontaneously broken by radiative
corrections. It was noticed in previous work that masses in this model are not
gauge invariant at one-loop order. In our analysis, we use the dressed
propagators of scalars which include a resummation of the one-loop self-energy
correction to the tree-level propagator. We calculate the one-loop self-energy
correction to the vector meson using these dressed propagators. We find that
the pole mass of the vector meson calculated using the dressed propagator is
gauge invariant at the vacuum determined using the effective potential
calculated with a resummation of daisy diagrams.
|
[
{
"created": "Thu, 7 Jan 2021 11:21:26 GMT",
"version": "v1"
},
{
"created": "Wed, 19 May 2021 13:01:17 GMT",
"version": "v2"
}
] |
2021-05-20
|
[
[
"Shen",
"Haojie",
""
],
[
"Cheng",
"Yu",
""
],
[
"Liao",
"Wei",
""
]
] |
We revisit the problem of the gauge invariance in the Coleman-Weinberg model in which a $U(1)$ gauge symmetry is driven spontaneously broken by radiative corrections. It was noticed in previous work that masses in this model are not gauge invariant at one-loop order. In our analysis, we use the dressed propagators of scalars which include a resummation of the one-loop self-energy correction to the tree-level propagator. We calculate the one-loop self-energy correction to the vector meson using these dressed propagators. We find that the pole mass of the vector meson calculated using the dressed propagator is gauge invariant at the vacuum determined using the effective potential calculated with a resummation of daisy diagrams.
|
hep-ph/0002078
|
Werner Vogelsang
|
Eric Laenen (NIKHEF), George Sterman, Werner Vogelsang (YITP, SUNY
Stony Brook)
|
Higher-Order QCD Corrections in Prompt Photon Production
|
9 Pages, LaTeX, two figures as eps files
|
Phys.Rev.Lett.84:4296-4299,2000
|
10.1103/PhysRevLett.84.4296
|
YITP-99-69, NIKHEF/2000-002
|
hep-ph
| null |
We exhibit a method for simultaneously treating recoil and threshold
corrections in single-photon inclusive cross sections, working within the
formalism of collinear factorization. This approach conserves both the energy
and transverse momentum of resummed radiation. At moderate p_T, we find the
potential for substantial enhancements from higher-order perturbative and
power-law nonperturbative corrections.
|
[
{
"created": "Mon, 7 Feb 2000 20:40:58 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Laenen",
"Eric",
"",
"NIKHEF"
],
[
"Sterman",
"George",
"",
"YITP, SUNY\n Stony Brook"
],
[
"Vogelsang",
"Werner",
"",
"YITP, SUNY\n Stony Brook"
]
] |
We exhibit a method for simultaneously treating recoil and threshold corrections in single-photon inclusive cross sections, working within the formalism of collinear factorization. This approach conserves both the energy and transverse momentum of resummed radiation. At moderate p_T, we find the potential for substantial enhancements from higher-order perturbative and power-law nonperturbative corrections.
|
1209.6063
|
Anirban Kundu
|
Anirban Kundu, Soumitra Nandi, Sunando Kumar Patra, Amarjit Soni
|
$B_s\to D_s K$ as a Probe of CPT Violation
|
v2: Discussions about LHCb reach added, final version to be published
in Phys. Rev. D
| null |
10.1103/PhysRevD.87.016005
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We discuss some possible signals of CPT violation in the $B_s$ system that
may be probed at the Large Hadron Collider (LHC). We show how one can construct
combinations ofobservables coming from tagged and untagged decay rates of
$B_s\to D_s^\pm K^\mp$ that can unambiguously differentiate between CPT
violating and CPT conserving new physics (NP) models contributing in $B_s-\bar
B_s$ mixing. We choose this particular mode as an illustrative example for two
reasons: (i) In the Standard Model, there is only one decay amplitude, so it is
easier to untangle any new physics; (ii) $B_s$ being a neutral meson, it is
possible to unambiguously identify any sign of CPT violation that occurs only
in mixing but not in decay. We define an observable which is useful to extract
the CPT violating parameter in $B_s$ decay, and also discuss how far the
results are applicable even if CPT violation is present in both mixing and
decay.
|
[
{
"created": "Wed, 26 Sep 2012 20:04:55 GMT",
"version": "v1"
},
{
"created": "Fri, 4 Jan 2013 03:03:59 GMT",
"version": "v2"
}
] |
2013-05-30
|
[
[
"Kundu",
"Anirban",
""
],
[
"Nandi",
"Soumitra",
""
],
[
"Patra",
"Sunando Kumar",
""
],
[
"Soni",
"Amarjit",
""
]
] |
We discuss some possible signals of CPT violation in the $B_s$ system that may be probed at the Large Hadron Collider (LHC). We show how one can construct combinations ofobservables coming from tagged and untagged decay rates of $B_s\to D_s^\pm K^\mp$ that can unambiguously differentiate between CPT violating and CPT conserving new physics (NP) models contributing in $B_s-\bar B_s$ mixing. We choose this particular mode as an illustrative example for two reasons: (i) In the Standard Model, there is only one decay amplitude, so it is easier to untangle any new physics; (ii) $B_s$ being a neutral meson, it is possible to unambiguously identify any sign of CPT violation that occurs only in mixing but not in decay. We define an observable which is useful to extract the CPT violating parameter in $B_s$ decay, and also discuss how far the results are applicable even if CPT violation is present in both mixing and decay.
|
hep-ph/0312214
|
G. N. Shestakov
|
N.N. Achasov and G.N. Shestakov (Institute for Mathematics,
Novosibirsk, Russia)
|
Proposed Search for $a^0_0(980)-f_0(980)$ Mixing in Polarization
Phenomena
|
RevTeX, 9 pages, 1 figure. A number of typographical and grammatical
errors corrected
|
Phys.Rev.Lett. 92 (2004) 182001
|
10.1103/PhysRevLett.92.182001
| null |
hep-ph hep-ex nucl-ex nucl-th
| null |
The $K^+$ and $K^0$ meson mass difference induces the mixing of the
$a^0_0(980)$ and $f_0(980)$ resonances, the amplitude of which, between the
$K^+K^-$ and $K^0\bar K^0$ thresholds, is large in magnitude, of the order of $
m_{K}\sqrt{m^2_{K^0}-m^2_{K^+}}\approx\sqrt\alpha m^2_K$, and possesses the
phase sharply varying by about 90$^\circ$. We suggest performing the polarized
target experiments on the reaction $\pi^-p\to\eta\pi^0n$ at high energy in
which the fact of the existence of $a^0_0(980)-f_0(980)$ mixing can be
unambiguously and very easily established through the presence of a strong jump
in the azimuthal asymmetry of the $\eta\pi^0$ $S$ wave production cross section
near the $K\bar K$ thresholds. The presented estimates of the polarization
effect to be expected in experiment are to a great extent model independent.
|
[
{
"created": "Tue, 16 Dec 2003 15:09:30 GMT",
"version": "v1"
},
{
"created": "Thu, 6 May 2004 07:32:38 GMT",
"version": "v2"
}
] |
2009-11-10
|
[
[
"Achasov",
"N. N.",
"",
"Institute for Mathematics,\n Novosibirsk, Russia"
],
[
"Shestakov",
"G. N.",
"",
"Institute for Mathematics,\n Novosibirsk, Russia"
]
] |
The $K^+$ and $K^0$ meson mass difference induces the mixing of the $a^0_0(980)$ and $f_0(980)$ resonances, the amplitude of which, between the $K^+K^-$ and $K^0\bar K^0$ thresholds, is large in magnitude, of the order of $ m_{K}\sqrt{m^2_{K^0}-m^2_{K^+}}\approx\sqrt\alpha m^2_K$, and possesses the phase sharply varying by about 90$^\circ$. We suggest performing the polarized target experiments on the reaction $\pi^-p\to\eta\pi^0n$ at high energy in which the fact of the existence of $a^0_0(980)-f_0(980)$ mixing can be unambiguously and very easily established through the presence of a strong jump in the azimuthal asymmetry of the $\eta\pi^0$ $S$ wave production cross section near the $K\bar K$ thresholds. The presented estimates of the polarization effect to be expected in experiment are to a great extent model independent.
|
2305.07999
|
Kazem Azizi
|
A. R. Olamaei, S. Rostami, K. Azizi
|
Charm content of the proton: An analytic calculation
|
6 Pages and 2 Figures
| null | null | null |
hep-ph hep-ex hep-lat nucl-th
|
http://creativecommons.org/licenses/by/4.0/
|
According to general understanding, the proton as one of the main ingredients
of the nucleus is composed of one down and two up quarks bound together by
gluons, described by Quantum Chromodynamics (QCD). In this view, heavy quarks
do not contribute to the primary wave function of the proton. Heavy quarks
arise in the proton perturbatively by gluon splitting and the probability
gradually increases as $Q^2$ increases (extrinsic heavy quarks). In addition,
the existence of non-perturbative intrinsic charm quarks in the proton has also
been predicted by QCD. In this picture, the heavy quarks also exist in the
proton's wave function. In fact, the wave function has a five-quark structure $
\vert u u d c \bar{c}\rangle $ in addition to the three-quark bound state $
\vert u u d\rangle $. So far, many studies have been done to confirm or reject
this additional component. One of the recent studies has been done by the NNPDF
collaboration. They established the existence of an intrinsic charm component
at the 3-standard-deviation level in the proton from the structure function
measurements. Most of the studies performed to calculate the contribution of
the intrinsic charm so far have been based on the global analyses of the
experimental data. In this article, for the first time we directly calculate
this contribution by an analytic method. We estimate a $x^{c\bar{c}} = (1.36
\pm 0.67)\% $ contribution for the $ \vert u u d c \bar{c}\rangle $ component
of the proton.
|
[
{
"created": "Sat, 13 May 2023 20:42:09 GMT",
"version": "v1"
},
{
"created": "Sun, 16 Jul 2023 12:52:29 GMT",
"version": "v2"
},
{
"created": "Fri, 8 Dec 2023 18:14:10 GMT",
"version": "v3"
},
{
"created": "Thu, 21 Dec 2023 08:07:52 GMT",
"version": "v4"
}
] |
2023-12-22
|
[
[
"Olamaei",
"A. R.",
""
],
[
"Rostami",
"S.",
""
],
[
"Azizi",
"K.",
""
]
] |
According to general understanding, the proton as one of the main ingredients of the nucleus is composed of one down and two up quarks bound together by gluons, described by Quantum Chromodynamics (QCD). In this view, heavy quarks do not contribute to the primary wave function of the proton. Heavy quarks arise in the proton perturbatively by gluon splitting and the probability gradually increases as $Q^2$ increases (extrinsic heavy quarks). In addition, the existence of non-perturbative intrinsic charm quarks in the proton has also been predicted by QCD. In this picture, the heavy quarks also exist in the proton's wave function. In fact, the wave function has a five-quark structure $ \vert u u d c \bar{c}\rangle $ in addition to the three-quark bound state $ \vert u u d\rangle $. So far, many studies have been done to confirm or reject this additional component. One of the recent studies has been done by the NNPDF collaboration. They established the existence of an intrinsic charm component at the 3-standard-deviation level in the proton from the structure function measurements. Most of the studies performed to calculate the contribution of the intrinsic charm so far have been based on the global analyses of the experimental data. In this article, for the first time we directly calculate this contribution by an analytic method. We estimate a $x^{c\bar{c}} = (1.36 \pm 0.67)\% $ contribution for the $ \vert u u d c \bar{c}\rangle $ component of the proton.
|
1510.01684
|
Omar Gustavo Miranda
|
B. C. Canas, O. G. Miranda, A. Parada, M. Tortola, J. W. F. Valle
|
Updating neutrino magnetic moment constraints
|
20 pages, 4 figures, Addendum on the limit from the Borexino data
| null |
10.1016/j.physletb.2015.12.011
|
IFIC/15-XX
|
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In this paper we provide an updated analysis of the neutrino magnetic moments
(NMMs), discussing both the constraints on the magnitudes of the three
transition moments Lambda_i as well as the role of the CP violating phases
present both in the mixing matrix and in the NMM matrix. The scattering of
solar neutrinos off electrons in Borexino provides the most stringent
restrictions, due to its robust statistics and the low energies observed, below
1 MeV. Our new limit on the effective neutrino magnetic moment which follows
from the most recent Borexino data is 3.1 x 10^-11 mu_B at 90% C.L. This
corresponds to the individual transition magnetic moment constraints:
|Lambda_1| < 5.6 x10^-11 mu_B, |Lambda_2| < 4.0 x 10^-11 mu_B, and |Lambda_3| <
3.1 x 10^-11 mu_B (90% C.L.), irrespective of any complex phase. Indeed, the
incoherent admixture of neutrino mass eigenstates present in the solar flux
makes Borexino insensitive to the Majorana phases present in the NMM matrix.
For this reason we also provide a global analysis including the case of reactor
and accelerator neutrino sources, and presenting the resulting constraints for
different values of the relevant CP phases. Improved reactor and accelerator
neutrino experiments will be needed in order to underpin the full profile of
the neutrino electromagnetic properties.
|
[
{
"created": "Tue, 6 Oct 2015 18:22:40 GMT",
"version": "v1"
},
{
"created": "Thu, 10 Mar 2016 12:07:21 GMT",
"version": "v2"
}
] |
2016-03-11
|
[
[
"Canas",
"B. C.",
""
],
[
"Miranda",
"O. G.",
""
],
[
"Parada",
"A.",
""
],
[
"Tortola",
"M.",
""
],
[
"Valle",
"J. W. F.",
""
]
] |
In this paper we provide an updated analysis of the neutrino magnetic moments (NMMs), discussing both the constraints on the magnitudes of the three transition moments Lambda_i as well as the role of the CP violating phases present both in the mixing matrix and in the NMM matrix. The scattering of solar neutrinos off electrons in Borexino provides the most stringent restrictions, due to its robust statistics and the low energies observed, below 1 MeV. Our new limit on the effective neutrino magnetic moment which follows from the most recent Borexino data is 3.1 x 10^-11 mu_B at 90% C.L. This corresponds to the individual transition magnetic moment constraints: |Lambda_1| < 5.6 x10^-11 mu_B, |Lambda_2| < 4.0 x 10^-11 mu_B, and |Lambda_3| < 3.1 x 10^-11 mu_B (90% C.L.), irrespective of any complex phase. Indeed, the incoherent admixture of neutrino mass eigenstates present in the solar flux makes Borexino insensitive to the Majorana phases present in the NMM matrix. For this reason we also provide a global analysis including the case of reactor and accelerator neutrino sources, and presenting the resulting constraints for different values of the relevant CP phases. Improved reactor and accelerator neutrino experiments will be needed in order to underpin the full profile of the neutrino electromagnetic properties.
|
2006.15451
|
Vladyslav Shtabovenko
|
Nora Brambilla, Hee Sok Chung, Vladyslav Shtabovenko, Antonio Vairo
|
FeynOnium: Using FeynCalc for automatic calculations in Nonrelativistic
Effective Field Theories
|
61 pages, no figures, matches the version accepted in JHEP. To obtain
the programs, see https://github.com/FeynCalc
|
JHEP 11 (2020) 130
|
10.1007/JHEP11(2020)130
|
TUM-EFT 75/15, TTP19-021
|
hep-ph cond-mat.str-el hep-lat hep-th nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We present new results on FeynOnium, an ongoing project to develop a general
purpose software toolkit for semi-automatic symbolic calculations in
nonrelativistic Effective Field Theories (EFTs). Building upon FeynCalc, an
existing Mathematica package for symbolic evaluation of Feynman diagrams, we
have created a powerful framework for automatizing calculations in
nonrelativistic EFTs (NREFTs) at tree- and 1-loop level. This is achieved by
exploiting the novel features of FeynCalc that support manipulations of
Cartesian tensors, Pauli matrices and nonstandard loop integrals. Additional
operations that are common in nonrelativistic EFT calculations are implemented
in a dedicated add-on called FeynOnium. While our current focus is on EFTs for
strong interactions of heavy quarks, extensions to other systems that admit a
nonrelativistic EFT description are planned for the future. All our codes are
open-source and publicly available. Furthermore, we provide several example
calculations that demonstrate how FeynOnium can be employed to reproduce known
results from the literature.
|
[
{
"created": "Sat, 27 Jun 2020 21:35:55 GMT",
"version": "v1"
},
{
"created": "Mon, 30 Nov 2020 17:43:42 GMT",
"version": "v2"
}
] |
2020-12-01
|
[
[
"Brambilla",
"Nora",
""
],
[
"Chung",
"Hee Sok",
""
],
[
"Shtabovenko",
"Vladyslav",
""
],
[
"Vairo",
"Antonio",
""
]
] |
We present new results on FeynOnium, an ongoing project to develop a general purpose software toolkit for semi-automatic symbolic calculations in nonrelativistic Effective Field Theories (EFTs). Building upon FeynCalc, an existing Mathematica package for symbolic evaluation of Feynman diagrams, we have created a powerful framework for automatizing calculations in nonrelativistic EFTs (NREFTs) at tree- and 1-loop level. This is achieved by exploiting the novel features of FeynCalc that support manipulations of Cartesian tensors, Pauli matrices and nonstandard loop integrals. Additional operations that are common in nonrelativistic EFT calculations are implemented in a dedicated add-on called FeynOnium. While our current focus is on EFTs for strong interactions of heavy quarks, extensions to other systems that admit a nonrelativistic EFT description are planned for the future. All our codes are open-source and publicly available. Furthermore, we provide several example calculations that demonstrate how FeynOnium can be employed to reproduce known results from the literature.
|
1205.6382
|
Alexander Bylinkin
|
A. A. Bylinkin, A. A. Rostovtsev (Institute for Theoretical and
Experimental Physics, ITEP, Moscow, Russia)
|
A variation of the charged particle spectrum shape as function of
rapidity in high energy pp collisions
| null | null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The shapes of invariant differential cross section for charged particle
production as function of transverse momentum measured in pp collisions by the
UA1 detector are analyzed. The spectra shape varies with the produced
particle's pseudorapidity changing. To describe this and several other recently
observed effects a simple qualitative model for hadroproduction mechanism was
proposed.
|
[
{
"created": "Tue, 29 May 2012 15:02:04 GMT",
"version": "v1"
}
] |
2012-05-30
|
[
[
"Bylinkin",
"A. A.",
"",
"Institute for Theoretical and\n Experimental Physics, ITEP, Moscow, Russia"
],
[
"Rostovtsev",
"A. A.",
"",
"Institute for Theoretical and\n Experimental Physics, ITEP, Moscow, Russia"
]
] |
The shapes of invariant differential cross section for charged particle production as function of transverse momentum measured in pp collisions by the UA1 detector are analyzed. The spectra shape varies with the produced particle's pseudorapidity changing. To describe this and several other recently observed effects a simple qualitative model for hadroproduction mechanism was proposed.
|
1707.08124
|
Anders Johan Andreassen
|
Anders Andreassen, William Frost, and Matthew D. Schwartz
|
Scale Invariant Instantons and the Complete Lifetime of the Standard
Model
|
Typos corrected, numbers updated
|
Phys. Rev. D 97, 056006 (2018)
|
10.1103/PhysRevD.97.056006
| null |
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In a classically scale-invariant quantum field theory, tunneling rates are
infrared divergent due to the existence of instantons of any size. While one
expects such divergences to be resolved by quantum effects, it has been unclear
how higher-loop corrections can resolve a problem appearing already at one
loop. With a careful power counting, we uncover a series of loop contributions
that dominate over the one-loop result and sum all the necessary terms. We also
clarify previously incomplete treatments of related issues pertaining to global
symmetries, gauge fixing and finite mass effects. In addition, we produce exact
closed-form solutions for the functional determinants over scalars, fermions
and vector bosons around the scale-invariant bounce, demonstrating manifest
gauge invariance in the vector case.
With these problems solved, we produce the first complete calculation of the
lifetime of our universe: 10^139 years. With 95% confidence, we expect our
universe to last more than 10^58 years. The uncertainty is part experimental
uncertainty on the top quark mass and on ${\alpha}s$ and part theory
uncertainty from electroweak threshold corrections. Using our complete result,
we provide phase diagrams in the $mt/mh$ and the $mt/{\alpha}s$ planes, with
uncertainty bands. To rule out absolute stability to $3{\sigma}$ confidence,
the uncertainty on the top quark pole mass would have to be pushed below 250
MeV or the uncertainty on ${\alpha}s(mZ)$ pushed below 0.00025.
|
[
{
"created": "Tue, 25 Jul 2017 18:00:04 GMT",
"version": "v1"
},
{
"created": "Thu, 31 Aug 2017 16:04:02 GMT",
"version": "v2"
},
{
"created": "Sat, 3 Feb 2018 19:02:40 GMT",
"version": "v3"
},
{
"created": "Wed, 2 May 2018 20:13:30 GMT",
"version": "v4"
}
] |
2018-05-04
|
[
[
"Andreassen",
"Anders",
""
],
[
"Frost",
"William",
""
],
[
"Schwartz",
"Matthew D.",
""
]
] |
In a classically scale-invariant quantum field theory, tunneling rates are infrared divergent due to the existence of instantons of any size. While one expects such divergences to be resolved by quantum effects, it has been unclear how higher-loop corrections can resolve a problem appearing already at one loop. With a careful power counting, we uncover a series of loop contributions that dominate over the one-loop result and sum all the necessary terms. We also clarify previously incomplete treatments of related issues pertaining to global symmetries, gauge fixing and finite mass effects. In addition, we produce exact closed-form solutions for the functional determinants over scalars, fermions and vector bosons around the scale-invariant bounce, demonstrating manifest gauge invariance in the vector case. With these problems solved, we produce the first complete calculation of the lifetime of our universe: 10^139 years. With 95% confidence, we expect our universe to last more than 10^58 years. The uncertainty is part experimental uncertainty on the top quark mass and on ${\alpha}s$ and part theory uncertainty from electroweak threshold corrections. Using our complete result, we provide phase diagrams in the $mt/mh$ and the $mt/{\alpha}s$ planes, with uncertainty bands. To rule out absolute stability to $3{\sigma}$ confidence, the uncertainty on the top quark pole mass would have to be pushed below 250 MeV or the uncertainty on ${\alpha}s(mZ)$ pushed below 0.00025.
|
hep-ph/9706483
|
FJ Yndurain
|
F. J. Yndurain
|
Dynamically generated masses in supersymmetric QCD and quark mass
problems
|
plain TeX file. Two figures
|
Phys.Lett. B416 (1998) 341-344
|
10.1016/S0370-2693(97)01334-8
|
FTUAM 97-1/UM-TH-97-15
|
hep-ph
| null |
We consider possible mechanical masses that could appear in supersymmetry,
other than by direct Higgs coupling to fermions and we speculate that the
existence of such a type of mass would allow one to have the Higgs mass of the
$u$ quark zero, and the Higgs mass of the $d$ quark (at 1 \gev) of $\approx 1
\to 2 MeV$, thus solving at the same time the strong CP problem and arranging
the grand unification prediction $m_{\mu}/m_{e} = m_{s, Higgs}/m_{d, Higgs}.$
One possible mechanism for this is related to, but not identical with the quark
condensate. Here a mass is generated which is the same for all quarks, and
which adds to the Higgs type mass. Unfortunately, the numerical value of the
generated mass falls short of the desired value (some 5 MeV) by orders of
magnitude. An alternate mechanism, through Higgs-induced left-right couplings
in the squark sector may produce masses of the correct order of magnitude if
the mixing angles are diferent in the squark and quark sectors. To get the
desired result for the $u$ quark mass, we need a stop component mixing of 1/20
for the $LR$ $\tilde{u}$ squark coupling, so the strong CP problem may still be
solved. For the $d$ mass, this mechanism is not really sufficient to solve the
grand unification mass ratio problem.
|
[
{
"created": "Tue, 24 Jun 1997 12:04:49 GMT",
"version": "v1"
}
] |
2009-10-30
|
[
[
"Yndurain",
"F. J.",
""
]
] |
We consider possible mechanical masses that could appear in supersymmetry, other than by direct Higgs coupling to fermions and we speculate that the existence of such a type of mass would allow one to have the Higgs mass of the $u$ quark zero, and the Higgs mass of the $d$ quark (at 1 \gev) of $\approx 1 \to 2 MeV$, thus solving at the same time the strong CP problem and arranging the grand unification prediction $m_{\mu}/m_{e} = m_{s, Higgs}/m_{d, Higgs}.$ One possible mechanism for this is related to, but not identical with the quark condensate. Here a mass is generated which is the same for all quarks, and which adds to the Higgs type mass. Unfortunately, the numerical value of the generated mass falls short of the desired value (some 5 MeV) by orders of magnitude. An alternate mechanism, through Higgs-induced left-right couplings in the squark sector may produce masses of the correct order of magnitude if the mixing angles are diferent in the squark and quark sectors. To get the desired result for the $u$ quark mass, we need a stop component mixing of 1/20 for the $LR$ $\tilde{u}$ squark coupling, so the strong CP problem may still be solved. For the $d$ mass, this mechanism is not really sufficient to solve the grand unification mass ratio problem.
|
hep-ph/9609448
|
Thomas Teubner
|
A. D. Martin (Centre for Particle Theory, Durham), M. G. Ryskin (Nucl.
Phys. Inst., Petersburg) and T. Teubner (CPT, Durham)
|
The QCD description of diffractive rho meson electroproduction
|
19 pages, LaTeX, 6 Postscript figures. The complete paper, including
figures, is also available via anonymous ftp at
ftp://cpt1.dur.ac.uk/pub/preprints/dtp96/dtp9664/
|
Phys. Rev. D 55, 4329 (1997)
|
10.1103/PhysRevD.55.4329
|
DTP/96/64
|
hep-ph
| null |
We critically review the QCD predictions for the cross sections sigma_L and
sigma_T for diffractive rho meson electroproduction in longitudinally and
transversely polarised states in the HERA energy region. We show that both
perturbative and non-perturbative approaches which involve convolution with the
rho meson wave function predict values of sigma_T which fall-off too quickly
with increasing Q^2, in comparison with the data. We present a perturbative QCD
model based on the open production of light qqbar pairs and parton-hadron
duality, which describes all features of the data for rho electroproduction at
high Q^2 and, in particular, predicts a satisfactory Q^2 behaviour of
sigma_L/sigma_T. We find that precise measurements of the latter can give
valuable information on the Q^2 behaviour of the gluon distribution at small x.
|
[
{
"created": "Tue, 24 Sep 1996 13:50:18 GMT",
"version": "v1"
}
] |
2016-08-24
|
[
[
"Martin",
"A. D.",
"",
"Centre for Particle Theory, Durham"
],
[
"Ryskin",
"M. G.",
"",
"Nucl.\n Phys. Inst., Petersburg"
],
[
"Teubner",
"T.",
"",
"CPT, Durham"
]
] |
We critically review the QCD predictions for the cross sections sigma_L and sigma_T for diffractive rho meson electroproduction in longitudinally and transversely polarised states in the HERA energy region. We show that both perturbative and non-perturbative approaches which involve convolution with the rho meson wave function predict values of sigma_T which fall-off too quickly with increasing Q^2, in comparison with the data. We present a perturbative QCD model based on the open production of light qqbar pairs and parton-hadron duality, which describes all features of the data for rho electroproduction at high Q^2 and, in particular, predicts a satisfactory Q^2 behaviour of sigma_L/sigma_T. We find that precise measurements of the latter can give valuable information on the Q^2 behaviour of the gluon distribution at small x.
|
2210.01547
|
Alexei Smirnov Yu
|
Evgeny Akhmedov and Alexei Y. Smirnov
|
Reply to "Comment on "Damping of neutrino oscillations, decoherence and
the lengths of neutrino wave packets""
|
3 pages, 1 figure
| null | null | null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
In arXiv:2209.00561 our treatment arXiv:2208.03736 of effects of particles
emitted together with neutrinos on neutrino wave packets is criticized on
several grounds. We show here that this criticism is based on misinterpretation
of our results and is invalid. Our conclusions and, in particular, the
conclusion that neutrino wave packet separation effects are unobservable in
reactor and neutrino source experiments, remain unchanged.
|
[
{
"created": "Tue, 4 Oct 2022 12:19:08 GMT",
"version": "v1"
}
] |
2022-10-05
|
[
[
"Akhmedov",
"Evgeny",
""
],
[
"Smirnov",
"Alexei Y.",
""
]
] |
In arXiv:2209.00561 our treatment arXiv:2208.03736 of effects of particles emitted together with neutrinos on neutrino wave packets is criticized on several grounds. We show here that this criticism is based on misinterpretation of our results and is invalid. Our conclusions and, in particular, the conclusion that neutrino wave packet separation effects are unobservable in reactor and neutrino source experiments, remain unchanged.
|
0710.5791
|
Richard Hill
|
Richard J. Hill (Fermilab)
|
Topological physics in the standard model and beyond
|
6 pages, 2 figures, submitted for the SUSY07 proceedings
| null | null |
FERMILAB-CONF-07-584-T
|
hep-ph
| null |
Topological interactions are an essential ingredient for building consistent
low-energy theories of fermions, gauge fields and Nambu-Goldstone bosons in the
absence of explicit UV completions, such as in Little Higgs models. These
interactions are also a probe of UV completion physics that may be out of
direct experimental reach. The technology of topological, or Wess-Zumino-Witten
interactions is described, using explicit examples in the standard model and in
Little Higgs models. The construction of a simple topological action on
SU(3)/SU(2) is described. Inconsistencies in some popular Little Higgs models
are pointed out.
|
[
{
"created": "Wed, 31 Oct 2007 16:53:41 GMT",
"version": "v1"
}
] |
2007-11-01
|
[
[
"Hill",
"Richard J.",
"",
"Fermilab"
]
] |
Topological interactions are an essential ingredient for building consistent low-energy theories of fermions, gauge fields and Nambu-Goldstone bosons in the absence of explicit UV completions, such as in Little Higgs models. These interactions are also a probe of UV completion physics that may be out of direct experimental reach. The technology of topological, or Wess-Zumino-Witten interactions is described, using explicit examples in the standard model and in Little Higgs models. The construction of a simple topological action on SU(3)/SU(2) is described. Inconsistencies in some popular Little Higgs models are pointed out.
|
1601.03671
|
Ramona Gr\"ober
|
A. Agostini, G. Degrassi, R. Gr\"ober and P. Slavich
|
NLO-QCD corrections to Higgs pair production in the MSSM
|
32 pages, 2 figures, v2: version to appear in JHEP
| null |
10.1007/JHEP04(2016)106
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We take a step towards a complete NLO-QCD determination of the production of
a pair of Higgs scalars in the MSSM. Exploiting a low-energy theorem that
connects the Higgs-gluon interactions to the derivatives of the gluon
self-energy, we obtain analytic results for the one- and two-loop squark
contributions to Higgs pair production in the limit of vanishing external
momenta. We find that the two-loop squark contributions can have non-negligible
effects in MSSM scenarios with stop masses below the TeV scale. We also show
how our results can be adapted to the case of Higgs pair production in the
NMSSM.
|
[
{
"created": "Thu, 14 Jan 2016 17:25:09 GMT",
"version": "v1"
},
{
"created": "Mon, 18 Apr 2016 08:51:55 GMT",
"version": "v2"
}
] |
2016-05-04
|
[
[
"Agostini",
"A.",
""
],
[
"Degrassi",
"G.",
""
],
[
"Gröber",
"R.",
""
],
[
"Slavich",
"P.",
""
]
] |
We take a step towards a complete NLO-QCD determination of the production of a pair of Higgs scalars in the MSSM. Exploiting a low-energy theorem that connects the Higgs-gluon interactions to the derivatives of the gluon self-energy, we obtain analytic results for the one- and two-loop squark contributions to Higgs pair production in the limit of vanishing external momenta. We find that the two-loop squark contributions can have non-negligible effects in MSSM scenarios with stop masses below the TeV scale. We also show how our results can be adapted to the case of Higgs pair production in the NMSSM.
|
hep-ph/0404248
|
BingAn Li
|
Bing An Li
|
ee^+-->\pi^0\gamma and form factor of \pi^0\gamma^*\gamma^*
|
18 pages 5 figures
| null | null | null |
hep-ph
| null |
The form factor \pi^0\gamma^*\gamma^* is obtained to the next leading order
of derivative expansion of the chiral anomaly and the VMD. As a test the form
factor has been used to calculate the cross section of ee^+-->\pi^0\gamma.
Theory agrees with data.
|
[
{
"created": "Tue, 27 Apr 2004 20:00:54 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Li",
"Bing An",
""
]
] |
The form factor \pi^0\gamma^*\gamma^* is obtained to the next leading order of derivative expansion of the chiral anomaly and the VMD. As a test the form factor has been used to calculate the cross section of ee^+-->\pi^0\gamma. Theory agrees with data.
|
hep-ph/9409428
| null |
S. Narison
|
{$K^0$}-{$\overline{K}^0$} mixing and the CKM parameters $(\rho,\eta)$
from the Laplace sum rules
|
6 pages in latex file + 3 figure in ps files (sent by requests),
CERN-TH.7441/94 (1994) (some missprints in the previous version may lead to
some confusion)
|
Phys.Lett.B351:369-374,1995
|
10.1016/0370-2693(95)00295-V
| null |
hep-ph hep-lat
| null |
Using the Laplace sum rule (LSR) approach, which is less affected by the
contribution of the higher mass hadronic states than the Finite Energy Sum Rule
(FESR), we test the reliability of the existing estimate of the
$K^0$-$\overline {K}^0$ mixing parameter from the four-quark two-point
correlator. We obtain, for the renormalization group invariant $B$-parameter
$\Big[ f_K/(1.2f_\pi)\Big]^2 \hat {B}_K$, the upper bound: 0.83 and the $best$
estimate: $0.55 \pm 0.09$. Combining the previous estimate with the updated
value of $f_B\sqrt{B_B}=(1.49\pm 0.14)f_\pi$ obtained from the same LSR method,
one can deduce the $best$ fitted values $(\rho,\eta)\approx (0.41,0.09)$ of the
CKM parameters.
|
[
{
"created": "Tue, 27 Sep 1994 20:47:29 GMT",
"version": "v1"
},
{
"created": "Wed, 28 Sep 1994 20:43:31 GMT",
"version": "v2"
}
] |
2010-11-01
|
[
[
"Narison",
"S.",
""
]
] |
Using the Laplace sum rule (LSR) approach, which is less affected by the contribution of the higher mass hadronic states than the Finite Energy Sum Rule (FESR), we test the reliability of the existing estimate of the $K^0$-$\overline {K}^0$ mixing parameter from the four-quark two-point correlator. We obtain, for the renormalization group invariant $B$-parameter $\Big[ f_K/(1.2f_\pi)\Big]^2 \hat {B}_K$, the upper bound: 0.83 and the $best$ estimate: $0.55 \pm 0.09$. Combining the previous estimate with the updated value of $f_B\sqrt{B_B}=(1.49\pm 0.14)f_\pi$ obtained from the same LSR method, one can deduce the $best$ fitted values $(\rho,\eta)\approx (0.41,0.09)$ of the CKM parameters.
|
1506.00417
|
Takehiko Asaka
|
Takehiko Asaka, Shintaro Eijima and Kazuhiro Takeda
|
Probing Baryon Asymmetry of the Universe by Using Lepton Universality
|
4 pages, 2 figures, Talk given by T. Asaka at the 2nd Toyama
International Workshop on "Higgs as a Probe of New Physics 2015" (HPNP2015),
Toyama, Japan, February 11-15, 2015
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study the model with three right-handed neutrinos which masses are smaller
than the weak scale ${\cal O}(10^2)$ GeV (called as the $\nu$MSM). The model
can explain the origin of neutrino masses by the seesaw mechanism, offer a
candidate of dark matter and realize the baryogenesis via neutrino oscillation.
The seesaw mechanism at such energy scales can induce phenomenon which are
observable by experiments. As an example, we discuss the lepton universality of
charged kaon decays in this model. It is shown that the heavy neutral leptons
accounting for the neutrino masses and the cosmic baryon asymmetry can give a
significant correction to the lepton universality, and that the deviation from
the Standard Model prediction can be large as ${\cal O}(10^{-3})$ which will be
probed by near future experiments.
|
[
{
"created": "Mon, 1 Jun 2015 10:06:36 GMT",
"version": "v1"
}
] |
2015-06-02
|
[
[
"Asaka",
"Takehiko",
""
],
[
"Eijima",
"Shintaro",
""
],
[
"Takeda",
"Kazuhiro",
""
]
] |
We study the model with three right-handed neutrinos which masses are smaller than the weak scale ${\cal O}(10^2)$ GeV (called as the $\nu$MSM). The model can explain the origin of neutrino masses by the seesaw mechanism, offer a candidate of dark matter and realize the baryogenesis via neutrino oscillation. The seesaw mechanism at such energy scales can induce phenomenon which are observable by experiments. As an example, we discuss the lepton universality of charged kaon decays in this model. It is shown that the heavy neutral leptons accounting for the neutrino masses and the cosmic baryon asymmetry can give a significant correction to the lepton universality, and that the deviation from the Standard Model prediction can be large as ${\cal O}(10^{-3})$ which will be probed by near future experiments.
|
1011.3202
|
Larry McLerran
|
Larry McLerran
|
Gluon Evolution and Saturation Proceedings
|
Presented at the Gribov Memorial Workshop on Quantum Chromodynamics
and Beyond
| null |
10.1142/9789814350198_0011
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Almost 40 years ago, Gribov and colleagues at the Leningrad Nuclear Physics
Institute developed the ideas that led to the
Dokhsitzer-Gribov-Altarelli-Parisi the Baltisky-Fadin-Kuraev-Lipatov equations.
These equations describe the evolution of the distributions for quarks and
gluon inside a hadron to increased resolution scale of a probe or to smaller
values of the fractional momentum of a hadronic constituent. I motivate and
discuss the generalization required of these equations needed for high energy
processes when the density of constituents is large. This leads to a theory of
saturation realized by the Color Glass Condensate
|
[
{
"created": "Sun, 14 Nov 2010 09:37:19 GMT",
"version": "v1"
}
] |
2017-08-23
|
[
[
"McLerran",
"Larry",
""
]
] |
Almost 40 years ago, Gribov and colleagues at the Leningrad Nuclear Physics Institute developed the ideas that led to the Dokhsitzer-Gribov-Altarelli-Parisi the Baltisky-Fadin-Kuraev-Lipatov equations. These equations describe the evolution of the distributions for quarks and gluon inside a hadron to increased resolution scale of a probe or to smaller values of the fractional momentum of a hadronic constituent. I motivate and discuss the generalization required of these equations needed for high energy processes when the density of constituents is large. This leads to a theory of saturation realized by the Color Glass Condensate
|
1011.0204
|
Gerhart Seidl
|
Gerhart Seidl
|
Unbroken discrete supersymmetry
|
21 pages in LaTeX, 4 figures, extended discussion included,
references added, major results unchanged
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We demonstrate, by giving a specific example, that supersymmetry can be left
unbroken without running into conflict with observation. The key idea is to
employ a discrete form of supersymmetry. Amongst other interesting features,
this construction goes roughly half the way in removing the hierarchy between
the observed cosmological constant and the vacuum energies expected from field
theory.
|
[
{
"created": "Sun, 31 Oct 2010 20:36:03 GMT",
"version": "v1"
},
{
"created": "Mon, 25 Feb 2013 23:34:40 GMT",
"version": "v2"
},
{
"created": "Sun, 15 Mar 2015 08:39:48 GMT",
"version": "v3"
}
] |
2015-03-17
|
[
[
"Seidl",
"Gerhart",
""
]
] |
We demonstrate, by giving a specific example, that supersymmetry can be left unbroken without running into conflict with observation. The key idea is to employ a discrete form of supersymmetry. Amongst other interesting features, this construction goes roughly half the way in removing the hierarchy between the observed cosmological constant and the vacuum energies expected from field theory.
|
hep-ph/9610544
|
Ian Hinchliffe
|
I. Hinchliffe, F.E. Paige, M.D. Shapiro, J. Soderqvist, and W. Yao
|
Precision SUSY Measurements at LHC
|
52 pages, Latex with 42 postscript figures. Postscript version also
at http://www-physics.lbl.gov/www/theorygroup/papers/39412.ps
|
Phys.Rev.D55:5520-5540,1997
|
10.1103/PhysRevD.55.5520
|
LBNL-39412
|
hep-ph
| null |
If supersymmetry exists at the electroweak scale, then it should be
discovered at the LHC. Determining masses, of supersymmetric particles however,
is more difficult. In this paper, methods are discussed to determine
combinations of masses and of branching ratios precisely from experimentally
observable distributions. In many cases such measurements alone can greatly
constrain the particular supersymmetric model and determine its parameters with
an accuracy of a few percent. Most of the results shown correspond to one year
of running at LHC at ``low luminosity'.
|
[
{
"created": "Wed, 30 Oct 1996 17:59:48 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Hinchliffe",
"I.",
""
],
[
"Paige",
"F. E.",
""
],
[
"Shapiro",
"M. D.",
""
],
[
"Soderqvist",
"J.",
""
],
[
"Yao",
"W.",
""
]
] |
If supersymmetry exists at the electroweak scale, then it should be discovered at the LHC. Determining masses, of supersymmetric particles however, is more difficult. In this paper, methods are discussed to determine combinations of masses and of branching ratios precisely from experimentally observable distributions. In many cases such measurements alone can greatly constrain the particular supersymmetric model and determine its parameters with an accuracy of a few percent. Most of the results shown correspond to one year of running at LHC at ``low luminosity'.
|
hep-ph/9411432
|
Alakabha Datta
|
T.J. Weiler, W.A. Simmons, S. Pakvasa and J.G. Learned
|
Gamma--Ray Bursters, Neutrinos, and Cosmology
|
21 pages, latex, two figures (part of the latex file)
| null | null |
UH-511-801-94 and VAND-TH-94-20
|
hep-ph astro-ph gr-qc
| null |
Gamma ray burst (GRB) objects are now widely thought to be at cosmological
distances, and thus represent enormous energy emission. Gamma ray spectra
extending to $GeV$ energies suggest the possiblity of accompanying neutrino
emission, and there are several models proposed suggesting the potential
detectability of such coincident neutrino bursts. With this in view, we examine
possible measurements that might be conducted to give experimental data useful
for astronomy, for cosmology and also neutrino properties. Of interest to
astronomy and cosmology, we show how measurement of neutrino flavor ratios
yields information on the nature and relative distance of the source. We point
out that cosmological time dilation might be measured for these sources using
neutrinos, as has been done for photons, and that neutrino oscillation lengths
in the range of $1$ to $10^5~Mpc$ can be probed with GRB neutrinos. We thus
note that these sources may make possible the first non-electromagnetic
measurements of the scale size of the universe. We discuss tests of the weak
equivalence principle, tests for flavor dependent gravitational couplings, and
tests for long time scale variation of physical constants. We also show that a
number of new bounds on neutrino properties (charge, mass, speed, lifetime)
could be facilitated to levels well beyond those already inferred from the
neutrino observation of SN1987A. We also examine the implications of these
physics opportunities for designers of neutrino telescopes. We conclude that
detection may be possible in planned instruments if the spectra are power law
extending to the $TeV$ energy region, and if the neutrino fluxes are equal to
or greater than the gamma ray fluxes. We emphasize the importance of low energy
detection in future experiments
|
[
{
"created": "Wed, 30 Nov 1994 03:06:42 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Weiler",
"T. J.",
""
],
[
"Simmons",
"W. A.",
""
],
[
"Pakvasa",
"S.",
""
],
[
"Learned",
"J. G.",
""
]
] |
Gamma ray burst (GRB) objects are now widely thought to be at cosmological distances, and thus represent enormous energy emission. Gamma ray spectra extending to $GeV$ energies suggest the possiblity of accompanying neutrino emission, and there are several models proposed suggesting the potential detectability of such coincident neutrino bursts. With this in view, we examine possible measurements that might be conducted to give experimental data useful for astronomy, for cosmology and also neutrino properties. Of interest to astronomy and cosmology, we show how measurement of neutrino flavor ratios yields information on the nature and relative distance of the source. We point out that cosmological time dilation might be measured for these sources using neutrinos, as has been done for photons, and that neutrino oscillation lengths in the range of $1$ to $10^5~Mpc$ can be probed with GRB neutrinos. We thus note that these sources may make possible the first non-electromagnetic measurements of the scale size of the universe. We discuss tests of the weak equivalence principle, tests for flavor dependent gravitational couplings, and tests for long time scale variation of physical constants. We also show that a number of new bounds on neutrino properties (charge, mass, speed, lifetime) could be facilitated to levels well beyond those already inferred from the neutrino observation of SN1987A. We also examine the implications of these physics opportunities for designers of neutrino telescopes. We conclude that detection may be possible in planned instruments if the spectra are power law extending to the $TeV$ energy region, and if the neutrino fluxes are equal to or greater than the gamma ray fluxes. We emphasize the importance of low energy detection in future experiments
|
hep-ph/9305239
|
Zoltan Trocsanyi
|
Zoltan Kunszt, Adrian Signer and Zolt\'an Tr\'ocs\'anyi
|
One-loop helicity amplitudes for all 2 -> 2 processes in QCD and N=1
supersymmetric Yang-Mills theory
|
40 pages + 1 table, uses LaTeX and table.tex, ETH-TH/93-11
|
Nucl.Phys. B411 (1994) 397-442
|
10.1016/0550-3213(94)90456-1
| null |
hep-ph
| null |
One loop corrections to the helicity amplitudes of all 2 -> 2 subprocesses
are calculated in QCD and in N=1 supersymmetric Yang-Mills theory using two
versions of dimensional regularization: the `t~Hooft-Veltman scheme and
dimensional reduction. Studying the structure of the soft and collinear
singularities, we found universal transition rules for the squared matrix
element which can be used to translate the results obtained in these schemes to
the results valid in the conventional dimensional regularization scheme. With
explicit calculation it is demonstrated that the one loop helicity amplitudes
of the 2 -> 2 subprocesses calculated using dimensional reduction in the N=1
supersymmetric $SU(N)$ gauge theory respect the supersymmetry Ward identities.
Our transition rules can also be used to calculate the next-to-leading order
Altarelli-Parisi kernels in the dimensional reduction scheme when they satisfy
supersymmetry Ward identities as well.
|
[
{
"created": "Tue, 11 May 1993 13:25:16 GMT",
"version": "v1"
}
] |
2009-10-22
|
[
[
"Kunszt",
"Zoltan",
""
],
[
"Signer",
"Adrian",
""
],
[
"Trócsányi",
"Zoltán",
""
]
] |
One loop corrections to the helicity amplitudes of all 2 -> 2 subprocesses are calculated in QCD and in N=1 supersymmetric Yang-Mills theory using two versions of dimensional regularization: the `t~Hooft-Veltman scheme and dimensional reduction. Studying the structure of the soft and collinear singularities, we found universal transition rules for the squared matrix element which can be used to translate the results obtained in these schemes to the results valid in the conventional dimensional regularization scheme. With explicit calculation it is demonstrated that the one loop helicity amplitudes of the 2 -> 2 subprocesses calculated using dimensional reduction in the N=1 supersymmetric $SU(N)$ gauge theory respect the supersymmetry Ward identities. Our transition rules can also be used to calculate the next-to-leading order Altarelli-Parisi kernels in the dimensional reduction scheme when they satisfy supersymmetry Ward identities as well.
|
hep-ph/0212256
|
Eugenio Marco Rubio
|
B. Borasoy, E. Marco, S. Wetzel
|
Eta, eta-prime photoproduction and electroproduction off nucleons
|
26 pages
|
Phys.Rev. C66 (2002) 055208
|
10.1103/PhysRevC.66.055208
| null |
hep-ph nucl-th
| null |
The photo- and electroproduction of eta, eta-prime mesons on nucleons are
investigated within a relativistic chiral unitary approach based on coupled
channels. The s-wave potentials for electroproduction and meson-baryon
scattering are derived from a chiral effective Lagrangian which includes the
eta-prime as an explicit degree of freedom and incorporates important features
of the underlying QCD Lagrangian such as the axial U(1) anomaly. The effective
potentials are iterated in a Bethe-Salpeter equation and cross sections for
eta, eta-prime photo- and electroproduction from nucleons are obtained. The
results for the eta-prime photoproduction cross section on protons reproduce
the appearance of an S_{11} resonance around 1.9 GeV observed at ELSA. The
inclusion of electromagnetic form factors increases the predicted eta
electroproduction cross sections on the proton, providing a qualitative
explanation for the hard form factor of the photocoupling amplitude observed at
CLAS.
|
[
{
"created": "Tue, 17 Dec 2002 21:16:07 GMT",
"version": "v1"
}
] |
2009-11-07
|
[
[
"Borasoy",
"B.",
""
],
[
"Marco",
"E.",
""
],
[
"Wetzel",
"S.",
""
]
] |
The photo- and electroproduction of eta, eta-prime mesons on nucleons are investigated within a relativistic chiral unitary approach based on coupled channels. The s-wave potentials for electroproduction and meson-baryon scattering are derived from a chiral effective Lagrangian which includes the eta-prime as an explicit degree of freedom and incorporates important features of the underlying QCD Lagrangian such as the axial U(1) anomaly. The effective potentials are iterated in a Bethe-Salpeter equation and cross sections for eta, eta-prime photo- and electroproduction from nucleons are obtained. The results for the eta-prime photoproduction cross section on protons reproduce the appearance of an S_{11} resonance around 1.9 GeV observed at ELSA. The inclusion of electromagnetic form factors increases the predicted eta electroproduction cross sections on the proton, providing a qualitative explanation for the hard form factor of the photocoupling amplitude observed at CLAS.
|
0901.4345
|
Joshua Wickman
|
Mansoor Ur Rehman, Qaisar Shafi, Joshua R. Wickman
|
Hybrid Inflation Revisited in Light of WMAP5
|
18 pages (double spaced), including 6 figures and 1 table (v1); 13
pages (single spaced), added 3 references to Ref. [14] and modified placement
of table and some figures (v2)
|
Phys.Rev.D79:103503,2009
|
10.1103/PhysRevD.79.103503
|
BA-09-02
|
hep-ph astro-ph.CO
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study the effects of including one-loop radiative corrections in a
non-supersymmetric hybrid inflationary model. These corrections can arise from
Yukawa couplings between the inflaton and right-handed neutrinos, and induce a
maximum in the potential which admits hilltop-type solutions in addition to the
standard hybrid solutions. We obtain a red-tilted spectral index $n_s$,
consistent with WMAP5 data, for sub-Planckian values of the field. This is in
contrast to the tree level hybrid analysis, in which a red-tilted spectrum is
achieved only for trans-Planckian values of the field. Successful reheating is
obtained at the end of the inflationary phase via conversion of the inflaton
and waterfall fields into right-handed neutrinos, whose subsequent decay can
explain the observed baryon asymmetry via leptogenesis.
|
[
{
"created": "Tue, 27 Jan 2009 21:02:53 GMT",
"version": "v1"
},
{
"created": "Thu, 12 Feb 2009 18:20:15 GMT",
"version": "v2"
}
] |
2009-10-29
|
[
[
"Rehman",
"Mansoor Ur",
""
],
[
"Shafi",
"Qaisar",
""
],
[
"Wickman",
"Joshua R.",
""
]
] |
We study the effects of including one-loop radiative corrections in a non-supersymmetric hybrid inflationary model. These corrections can arise from Yukawa couplings between the inflaton and right-handed neutrinos, and induce a maximum in the potential which admits hilltop-type solutions in addition to the standard hybrid solutions. We obtain a red-tilted spectral index $n_s$, consistent with WMAP5 data, for sub-Planckian values of the field. This is in contrast to the tree level hybrid analysis, in which a red-tilted spectrum is achieved only for trans-Planckian values of the field. Successful reheating is obtained at the end of the inflationary phase via conversion of the inflaton and waterfall fields into right-handed neutrinos, whose subsequent decay can explain the observed baryon asymmetry via leptogenesis.
|
hep-ph/0310310
|
Jim Bashford
|
J.D. Bashford
|
On the Standard Model and Strongly-Correlated Electron Systems
|
7 pages, 1 postscript figure
| null | null |
UTAS-PHYS-2003-06
|
hep-ph cond-mat.str-el
| null |
Higlighting certain similarities between the two-dimensional Luttinger liquid
model and the effective fermionic theory obtained from the hypercharge
Lagrangian, we argue the case for a new type of Standard Model extension.
|
[
{
"created": "Tue, 28 Oct 2003 10:25:46 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Bashford",
"J. D.",
""
]
] |
Higlighting certain similarities between the two-dimensional Luttinger liquid model and the effective fermionic theory obtained from the hypercharge Lagrangian, we argue the case for a new type of Standard Model extension.
|
hep-ph/9607351
|
John F. Donoghue
|
John F. Donoghue (Univ. of Massachusetts, Amherst)
|
Dispersion Relations and Effective Field Theory
|
21 pages, Latex, Lecture presented at the International School on
Effective Field Theories, Almunecar, Spain, June 1995. Admin note: two
figures not supplied
| null | null | null |
hep-ph
| null |
The techniques of dispersion relations match very well with those of
effective field theory. I describe the techniques for using dispersion
relations effectively, and give some pedagogical examples to illustrate the
range of applications.
|
[
{
"created": "Wed, 17 Jul 1996 14:29:00 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Donoghue",
"John F.",
"",
"Univ. of Massachusetts, Amherst"
]
] |
The techniques of dispersion relations match very well with those of effective field theory. I describe the techniques for using dispersion relations effectively, and give some pedagogical examples to illustrate the range of applications.
|
2404.02746
|
Victor Goncalves
|
Victor P. Goncalves, Bruno D. Moreira, Luana Santana
|
Probing the spatial distribution of gluons within the proton in the
coherent vector meson production at large $|t|$
|
9 pages, 5 figures, 1 table
| null | null | null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The coherent production of vector mesons in photon-hadron interactions is
considered one of the most promising observables to probe the QCD dynamics at
high energies and the transverse spatial distribution of the gluons in the
hadron wave function. In this letter, we perform an exploratory study about the
dependence of the transverse momentum distributions, $d\sigma/dt$, on the model
assumed for the proton density profile. We consider a set of non-Gaussian
profiles and include them in the forward dipole-proton scattering amplitude
associated with the IP-sat model. We demonstrate that the predictions for
$d\sigma/dt$ are similar in the HERA kinematical range, but are very distinct
for values of $t$ that will be probed in future colliders. In particular, the
presence of diffractive dips in the $t$-distributions associated with the
production of $J/\Psi$ and $\rho$ mesons is strongly dependent on the model
assumed for the density profile. Similar conclusions are also derived when the
non-linear effects on the dipole-target interaction are disregarded. Our
results indicate that a future study of the coherent vector meson production at
large $t$ will be useful to constrain the spatial distribution of gluons within
the proton.
|
[
{
"created": "Wed, 3 Apr 2024 13:43:56 GMT",
"version": "v1"
}
] |
2024-04-04
|
[
[
"Goncalves",
"Victor P.",
""
],
[
"Moreira",
"Bruno D.",
""
],
[
"Santana",
"Luana",
""
]
] |
The coherent production of vector mesons in photon-hadron interactions is considered one of the most promising observables to probe the QCD dynamics at high energies and the transverse spatial distribution of the gluons in the hadron wave function. In this letter, we perform an exploratory study about the dependence of the transverse momentum distributions, $d\sigma/dt$, on the model assumed for the proton density profile. We consider a set of non-Gaussian profiles and include them in the forward dipole-proton scattering amplitude associated with the IP-sat model. We demonstrate that the predictions for $d\sigma/dt$ are similar in the HERA kinematical range, but are very distinct for values of $t$ that will be probed in future colliders. In particular, the presence of diffractive dips in the $t$-distributions associated with the production of $J/\Psi$ and $\rho$ mesons is strongly dependent on the model assumed for the density profile. Similar conclusions are also derived when the non-linear effects on the dipole-target interaction are disregarded. Our results indicate that a future study of the coherent vector meson production at large $t$ will be useful to constrain the spatial distribution of gluons within the proton.
|
hep-ph/9905502
|
Toru Umekawa
|
T. Umekawa, K. Naito and M. Oka
|
Renormalization Group Approach to the O(N) linear Sigma Model at Finite
Temperature
|
21 pages, LaTex, 15 figures
| null | null |
TIT/HEP-420/NP
|
hep-ph
| null |
The Wilsonian renormalization group (RG) method is applied to finite
temperature systems for the study of non-perturbative methods in the field
theory. We choose the O(N) linear sigma model as the first step. Under the
local potential approximation, we solve the Wilsonian RG equation as a
non-linear partial differential equation numerically. The evolution of the
domain is taken into account using the naive cut and extrapolation procedure.
Our procedure is shown to yield the correct solution obtained by the auxiliary
field method in the large $N$ limit. To introduce thermal effects, we consider
two schemes. One in which the sum of the Matsubara frequencies are taken before
the scale is introduced is found to give more physical results. We observe a
second order phase transition in both the schemes. The critical exponents are
calculated and are shown to agree with the results from lattice calculations.
|
[
{
"created": "Thu, 27 May 1999 09:09:47 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Umekawa",
"T.",
""
],
[
"Naito",
"K.",
""
],
[
"Oka",
"M.",
""
]
] |
The Wilsonian renormalization group (RG) method is applied to finite temperature systems for the study of non-perturbative methods in the field theory. We choose the O(N) linear sigma model as the first step. Under the local potential approximation, we solve the Wilsonian RG equation as a non-linear partial differential equation numerically. The evolution of the domain is taken into account using the naive cut and extrapolation procedure. Our procedure is shown to yield the correct solution obtained by the auxiliary field method in the large $N$ limit. To introduce thermal effects, we consider two schemes. One in which the sum of the Matsubara frequencies are taken before the scale is introduced is found to give more physical results. We observe a second order phase transition in both the schemes. The critical exponents are calculated and are shown to agree with the results from lattice calculations.
|
2404.06533
|
Claudio Toni
|
David Marzocca, Marco Nardecchia, Alfredo Stanzione and Claudio Toni
|
Implications of $B \to K \nu \bar{\nu}$ under Rank-One Flavor Violation
hypothesis
|
34 pages, 13 figures
| null | null | null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
We study the implications of the observed excess in $B^+ \to K^+ \nu
\bar{\nu}$ under the assumption of Rank-One Flavour Violation, i.e. that New
Physics couples to a single specific direction in flavour space. By varying
this direction we perform analyses at the level of the low-energy EFT, the
SMEFT, and with explicit mediators such as leptoquarks and colorless vectors
($Z^\prime$ and $V^\prime$). We study correlations with other flavour,
electroweak and collider observables, finding that the most interesting ones
are with $K \to \pi \nu \bar{\nu}$, $B_s \to \mu^+ \mu^-$, meson mixing and the
LHC searches in $\tau^+ \tau^-$ high-energy tails. Among the various mediators,
the scalar leptoquarks $\tilde{R}_2$ and $S_1$ offer the best fits of the
Belle-II excess, while being consistent with the other bounds. On the other
hand, colorless vectors are strongly constrained by meson mixing and resonance
searches in $p p \to \tau^+ \tau^-$. In all cases we find that a flavour
alignment close to the third generation is generically preferred.
|
[
{
"created": "Tue, 9 Apr 2024 18:00:01 GMT",
"version": "v1"
}
] |
2024-04-11
|
[
[
"Marzocca",
"David",
""
],
[
"Nardecchia",
"Marco",
""
],
[
"Stanzione",
"Alfredo",
""
],
[
"Toni",
"Claudio",
""
]
] |
We study the implications of the observed excess in $B^+ \to K^+ \nu \bar{\nu}$ under the assumption of Rank-One Flavour Violation, i.e. that New Physics couples to a single specific direction in flavour space. By varying this direction we perform analyses at the level of the low-energy EFT, the SMEFT, and with explicit mediators such as leptoquarks and colorless vectors ($Z^\prime$ and $V^\prime$). We study correlations with other flavour, electroweak and collider observables, finding that the most interesting ones are with $K \to \pi \nu \bar{\nu}$, $B_s \to \mu^+ \mu^-$, meson mixing and the LHC searches in $\tau^+ \tau^-$ high-energy tails. Among the various mediators, the scalar leptoquarks $\tilde{R}_2$ and $S_1$ offer the best fits of the Belle-II excess, while being consistent with the other bounds. On the other hand, colorless vectors are strongly constrained by meson mixing and resonance searches in $p p \to \tau^+ \tau^-$. In all cases we find that a flavour alignment close to the third generation is generically preferred.
|
hep-ph/0301133
|
Thorsten Renk
|
Thorsten Renk
|
Emission of thermal photons and the equilibration time in Heavy-Ion
collisions
|
12 pages, 5 figures, accepted for publication at Phys. Rev. C
|
Phys.Rev. C67 (2003) 064901
|
10.1103/PhysRevC.67.064901
| null |
hep-ph
| null |
The emission of hard real photons from thermalized expanding hadronic matter
is dominated by the initial high-temperature expansion phase. Therefore, a
measurement of photon emission in ultrarelativistic heavy-ion collisions
provides valuable insights into the early conditions realized in such a
collision. In particular, the initial temperature of the expanding fireball or
equivalently the equilibration time of the strongly interacting matter are of
great interest. An accurate determination of these quantities could help to
answer the question whether or not partonic matter (the quark gluon plasma) is
created in such collisions. In this work, we investigate the emission of real
photons using a model which is based on the thermodynamics of QCD matter and
which has been shown to reproduce a large variety of other observables. With
the fireball evolution fixed beforehand, we are able to extract limits for the
equilibration time by a comparison with photon emission data measured by WA98.
|
[
{
"created": "Fri, 17 Jan 2003 12:55:41 GMT",
"version": "v1"
},
{
"created": "Fri, 2 May 2003 08:53:11 GMT",
"version": "v2"
}
] |
2009-11-10
|
[
[
"Renk",
"Thorsten",
""
]
] |
The emission of hard real photons from thermalized expanding hadronic matter is dominated by the initial high-temperature expansion phase. Therefore, a measurement of photon emission in ultrarelativistic heavy-ion collisions provides valuable insights into the early conditions realized in such a collision. In particular, the initial temperature of the expanding fireball or equivalently the equilibration time of the strongly interacting matter are of great interest. An accurate determination of these quantities could help to answer the question whether or not partonic matter (the quark gluon plasma) is created in such collisions. In this work, we investigate the emission of real photons using a model which is based on the thermodynamics of QCD matter and which has been shown to reproduce a large variety of other observables. With the fireball evolution fixed beforehand, we are able to extract limits for the equilibration time by a comparison with photon emission data measured by WA98.
|
hep-ph/0003055
|
K. Matsuda
|
K.Matsuda, N.Takeda, T.Fukuyama, H.Nishiura
|
CP Violations in Lepton Number Violation Processes and Neutrino
Oscillations
|
21pp, REVTeX, 9 Figures
|
Phys.Rev.D62:093001,2000
|
10.1103/PhysRevD.62.093001
| null |
hep-ph
| null |
We examine the constraints on the MNS lepton mixing matrix from the present
and future experimental data of the neutrino oscillation and lepton number
violation processes. We introduce a graphical representation of the CP
violation phases which appear in the lepton number violation processes such as
neutrinoless double beta decay, the $\mu^--e^+$ conversion, and the K decay,
$K^-\to\pi^+\mu^-\mu^-.$ Using this graphical representation, we derive the
constraints on the CP violation phases in the lepton sector.
|
[
{
"created": "Tue, 7 Mar 2000 11:56:30 GMT",
"version": "v1"
}
] |
2014-11-17
|
[
[
"Matsuda",
"K.",
""
],
[
"Takeda",
"N.",
""
],
[
"Fukuyama",
"T.",
""
],
[
"Nishiura",
"H.",
""
]
] |
We examine the constraints on the MNS lepton mixing matrix from the present and future experimental data of the neutrino oscillation and lepton number violation processes. We introduce a graphical representation of the CP violation phases which appear in the lepton number violation processes such as neutrinoless double beta decay, the $\mu^--e^+$ conversion, and the K decay, $K^-\to\pi^+\mu^-\mu^-.$ Using this graphical representation, we derive the constraints on the CP violation phases in the lepton sector.
|
hep-ph/0012216
|
Yuval Grossman
|
Yuval Grossman
|
Beyond the standard model with B physics
|
8 pages, LaTeX, no figures; to be published in Proceedings of Beauty
2000, Kibbutz Maagan, Israel, September 13-18, 2000, edited by S. Erhan, Y.
Rozen, and P.E. Schlein, Nucl. Inst. Meth. A, 2001
|
Nucl.Instrum.Meth.A462:52-56,2001
|
10.1016/S0168-9002(01)00023-7
| null |
hep-ph
| null |
Extensions of the Standard Model may have significant effects on B physics
observables. Two examples of methods that may find such effects are reviewed:
Resolving discrete ambiguities in CP asymmetries and detecting right handed
currents in radiative B decays.
|
[
{
"created": "Mon, 18 Dec 2000 08:38:42 GMT",
"version": "v1"
}
] |
2014-11-17
|
[
[
"Grossman",
"Yuval",
""
]
] |
Extensions of the Standard Model may have significant effects on B physics observables. Two examples of methods that may find such effects are reviewed: Resolving discrete ambiguities in CP asymmetries and detecting right handed currents in radiative B decays.
|
hep-ph/9710346
|
Boris Kastening
|
Boris Kastening (Universitaet Freiburg)
|
Five-Loop Vacuum Energy Beta Function in phi^4 Theory with
O(N)-Symmetric and Cubic Interactions
|
16 pages, LaTeX; "note added" fixed
|
Phys.Rev. D57 (1998) 3567-3578
|
10.1103/PhysRevD.57.3567
|
Freiburg-THEP 97/22
|
hep-ph cond-mat.stat-mech hep-th
| null |
The beta function of the vacuum energy density is analytically computed at
the five-loop level in O(N)-symmetric phi^4 theory, using dimensional
regularization in conjunction with the MSbar scheme. The result for the case of
a cubic anisotropy is also given. It is pointed out how to also obtain the beta
function of the coupling and the gamma function of the mass from vacuum graphs.
This method may be easier than traditional approaches.
|
[
{
"created": "Tue, 14 Oct 1997 14:09:19 GMT",
"version": "v1"
},
{
"created": "Wed, 14 Jan 1998 07:12:30 GMT",
"version": "v2"
},
{
"created": "Wed, 28 Jan 1998 14:08:43 GMT",
"version": "v3"
},
{
"created": "Tue, 31 Mar 1998 17:38:57 GMT",
"version": "v4"
}
] |
2007-05-23
|
[
[
"Kastening",
"Boris",
"",
"Universitaet Freiburg"
]
] |
The beta function of the vacuum energy density is analytically computed at the five-loop level in O(N)-symmetric phi^4 theory, using dimensional regularization in conjunction with the MSbar scheme. The result for the case of a cubic anisotropy is also given. It is pointed out how to also obtain the beta function of the coupling and the gamma function of the mass from vacuum graphs. This method may be easier than traditional approaches.
|
hep-ph/0006184
|
Anna M. Stasto
|
M.A. Kimber, J. Kwiecinski, A.D. Martin and A.M. Stasto
|
The unintegrated gluon distribution from the CCFM equation
|
16 pages LaTeX, 3 eps figures
|
Phys.Rev.D62:094006,2000
|
10.1103/PhysRevD.62.094006
|
DTP/00/34
|
hep-ph
| null |
The gluon distribution f(x, k_t^2,mu^2), unintegrated over the transverse
momentum k_t of the gluon, satisfies the angular-ordered CCFM equation which
interlocks the dependence on the scale k_t with the scale \mu of the probe. We
show how, to leading logarithmic accuracy, the equation can be simplified to a
single scale problem. In particular we demonstrate how to determine the
two-scale unintegrated distribution f(x,k_t^2,mu^2) from knowledge of the
integrated gluon obtained from a unified scheme embodying both BFKL and DGLAP
evolution.
|
[
{
"created": "Fri, 16 Jun 2000 07:35:24 GMT",
"version": "v1"
}
] |
2014-11-17
|
[
[
"Kimber",
"M. A.",
""
],
[
"Kwiecinski",
"J.",
""
],
[
"Martin",
"A. D.",
""
],
[
"Stasto",
"A. M.",
""
]
] |
The gluon distribution f(x, k_t^2,mu^2), unintegrated over the transverse momentum k_t of the gluon, satisfies the angular-ordered CCFM equation which interlocks the dependence on the scale k_t with the scale \mu of the probe. We show how, to leading logarithmic accuracy, the equation can be simplified to a single scale problem. In particular we demonstrate how to determine the two-scale unintegrated distribution f(x,k_t^2,mu^2) from knowledge of the integrated gluon obtained from a unified scheme embodying both BFKL and DGLAP evolution.
|
1308.4664
|
Fernando Iguaz\'u Ram\'irez Zavaleta
|
J. I. Aranda, F. Ramirez-Zavaleta, F. J. Tlachino, J. J. Toscano and
E. S. Tututi
|
Lorentz-violating effects on pair production of W bosons in photon
collisions
|
25 pages and 23 figures. arXiv admin note: substantial text overlap
with arXiv:1305.4265
| null |
10.1142/S0217751X14501802
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We examine Lorentz-violating effects that could appear through deviations of
the Standard Model gauge couplings WWgamma and WWgammagamma. These new physics
effects are explored on the gamma gamma -> WW reaction at the International
Linear Collider. In particular, the associated helicity amplitudes are computed
in the context of the Standard Model Extension (which is a model-independent
approach to CPT and Lorentz violation) and the Effective Lagrangian Model
(which incorporates new physics effects that respect CPT and Lorentz
violation). We perform an exhaustive study of the polarized differential cross
sections to stand out effects related to Lorentz symmetry violation, where it
is evidenced that the effects of Lorentz symmetry violation are more sensitive
to the presence of the b constant background field. We found that for the
$(\pm,\pm,(L,T+T,L))$ polarization state, only Standard Model Extension and
Effective Lagrangian Model contribute at the lowest order, however, both types
of new physics effects are clearly distinguished, being dominant the convoluted
cross section of the Standard Model Extension in around 4 orders of magnitude.
For this polarization state, at the last stage of operation of International
Linear Collider, it is expected an integrated luminosity of 10^3 fb^{-1},
finding around of 2 events for a Lorentz-violating energy scale of 32 TeV.
|
[
{
"created": "Wed, 21 Aug 2013 19:14:18 GMT",
"version": "v1"
}
] |
2015-06-17
|
[
[
"Aranda",
"J. I.",
""
],
[
"Ramirez-Zavaleta",
"F.",
""
],
[
"Tlachino",
"F. J.",
""
],
[
"Toscano",
"J. J.",
""
],
[
"Tututi",
"E. S.",
""
]
] |
We examine Lorentz-violating effects that could appear through deviations of the Standard Model gauge couplings WWgamma and WWgammagamma. These new physics effects are explored on the gamma gamma -> WW reaction at the International Linear Collider. In particular, the associated helicity amplitudes are computed in the context of the Standard Model Extension (which is a model-independent approach to CPT and Lorentz violation) and the Effective Lagrangian Model (which incorporates new physics effects that respect CPT and Lorentz violation). We perform an exhaustive study of the polarized differential cross sections to stand out effects related to Lorentz symmetry violation, where it is evidenced that the effects of Lorentz symmetry violation are more sensitive to the presence of the b constant background field. We found that for the $(\pm,\pm,(L,T+T,L))$ polarization state, only Standard Model Extension and Effective Lagrangian Model contribute at the lowest order, however, both types of new physics effects are clearly distinguished, being dominant the convoluted cross section of the Standard Model Extension in around 4 orders of magnitude. For this polarization state, at the last stage of operation of International Linear Collider, it is expected an integrated luminosity of 10^3 fb^{-1}, finding around of 2 events for a Lorentz-violating energy scale of 32 TeV.
|
hep-ph/0401071
|
Wayne W. Repko
|
Alberto Devoto, Stefano Di Chiara and Wayne W. Repko
|
Noncommutative QCD corrections to the gluonic decays of heavy quarkonia
|
Version accepted for publication
|
Phys.Lett. B588 (2004) 85-89
|
10.1016/j.physletb.2004.03.028
| null |
hep-ph
| null |
We compute the Noncommutative QCD (NCQCD) contributions to the three gluon
decay modes of heavy quarkonia. For triplet quarkonia (ortho-quarkonia), the
NCQCD correction to the QCD three gluon decay mode, like the standard model
contribution, is infrared finite. In the case of singlet quarkonia
(para-quarkonia), whose QCD three gluon decay mode has infrared singularities
which are removed using one-loop corrections to the two gluon mode, we find
that NCQCD contribution is also infrared finite. The calculations are performed
in the weak binding limit and do not require the introduction of additional
effective couplings.
|
[
{
"created": "Sun, 11 Jan 2004 22:02:11 GMT",
"version": "v1"
},
{
"created": "Wed, 25 Feb 2004 22:30:26 GMT",
"version": "v2"
},
{
"created": "Wed, 10 Mar 2004 18:56:53 GMT",
"version": "v3"
}
] |
2009-11-10
|
[
[
"Devoto",
"Alberto",
""
],
[
"Di Chiara",
"Stefano",
""
],
[
"Repko",
"Wayne W.",
""
]
] |
We compute the Noncommutative QCD (NCQCD) contributions to the three gluon decay modes of heavy quarkonia. For triplet quarkonia (ortho-quarkonia), the NCQCD correction to the QCD three gluon decay mode, like the standard model contribution, is infrared finite. In the case of singlet quarkonia (para-quarkonia), whose QCD three gluon decay mode has infrared singularities which are removed using one-loop corrections to the two gluon mode, we find that NCQCD contribution is also infrared finite. The calculations are performed in the weak binding limit and do not require the introduction of additional effective couplings.
|
hep-ph/9610446
|
Bhashyam Balaji
|
B. Balaji
|
Top Decay in Topcolor-Assisted Technicolor
|
10 pages, 1 figure, TeX, harvmac.tex
|
Phys.Lett. B393 (1997) 89-93
|
10.1016/S0370-2693(96)01606-1
|
BUHEP-96-29
|
hep-ph
| null |
Conventional technicolor models with light charged technipions ($\pi ^{\pm}
_T$) lead to an unacceptably large contribution to $t\ra {\pi ^+_T} b$ decay
rate. Topcolor-assisted technicolor models also have additional PGBs called
top-pions ($\pi ^{\pm}_t$) which may contribute to this decay. We study the
potentially dangerous mixing of charged top-pion and technipions in toy models
of `natural' topcolor-assisted technicolor. We find that the $t\ra {\pi
^+_{t,T}} b$ decay rate in such models can be within experimental limits due to
a combination of heavy top-pion and small $\pi _t - \pi_T$ mixing.
|
[
{
"created": "Tue, 22 Oct 1996 22:22:54 GMT",
"version": "v1"
}
] |
2009-10-30
|
[
[
"Balaji",
"B.",
""
]
] |
Conventional technicolor models with light charged technipions ($\pi ^{\pm} _T$) lead to an unacceptably large contribution to $t\ra {\pi ^+_T} b$ decay rate. Topcolor-assisted technicolor models also have additional PGBs called top-pions ($\pi ^{\pm}_t$) which may contribute to this decay. We study the potentially dangerous mixing of charged top-pion and technipions in toy models of `natural' topcolor-assisted technicolor. We find that the $t\ra {\pi ^+_{t,T}} b$ decay rate in such models can be within experimental limits due to a combination of heavy top-pion and small $\pi _t - \pi_T$ mixing.
|
2106.11319
|
Kirill Boguslavski
|
Kirill Boguslavski, Tuomas Lappi, Mark Mace, S\"oren Schlichting
|
Spectral function of fermions in a highly occupied non-Abelian plasma
|
13 pages, 6 figures; v2: minor revision, data and plot files
attached, published in Phys. Lett. B
| null |
10.1016/j.physletb.2022.136963
| null |
hep-ph hep-lat nucl-th
|
http://creativecommons.org/licenses/by/4.0/
|
We develop a method to obtain fermion spectral functions non-perturbatively
in a non-Abelian gauge theory with high occupation numbers of gauge fields.
After recovering the free field case, we extract the spectral function of
fermions in a highly occupied non-Abelian plasma close to its non-thermal fixed
point, i.e., in a self-similar regime of the non-equilibrium dynamics. We find
good agreement with hard loop perturbation theory for medium-induced masses,
dispersion relations and quasiparticle residues. We also extract the full
momentum dependence of the damping rate of the collective excitations.
|
[
{
"created": "Mon, 21 Jun 2021 18:00:01 GMT",
"version": "v1"
},
{
"created": "Thu, 8 Dec 2022 19:20:23 GMT",
"version": "v2"
}
] |
2022-12-12
|
[
[
"Boguslavski",
"Kirill",
""
],
[
"Lappi",
"Tuomas",
""
],
[
"Mace",
"Mark",
""
],
[
"Schlichting",
"Sören",
""
]
] |
We develop a method to obtain fermion spectral functions non-perturbatively in a non-Abelian gauge theory with high occupation numbers of gauge fields. After recovering the free field case, we extract the spectral function of fermions in a highly occupied non-Abelian plasma close to its non-thermal fixed point, i.e., in a self-similar regime of the non-equilibrium dynamics. We find good agreement with hard loop perturbation theory for medium-induced masses, dispersion relations and quasiparticle residues. We also extract the full momentum dependence of the damping rate of the collective excitations.
|
1608.06773
|
Nikita Agasian
|
N.O. Agasian
|
Low-energy relation for the trace of the energy-momentum tensor in QCD
and the gluon condensate in a magnetic field
|
8 pages
|
JETP Lett. 104 (2016) no.2, 71-74; Pisma Zh.Eksp.Teor.Fiz. 104
(2016) no.2, 71-74
|
10.1134/S002136401614006X
| null |
hep-ph hep-lat
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
A treatment is given of the nonperturbative QCD vacuum in a magnetic field.
The low-energy equation for the trace of the energy-momentum tensor in a
magnetic field is derived. It is shown that the derivatives with respect to a
magnetic field of the quark and gluon contributions to the trace of the
energy-momentum tensor are equal. The dependence of the gluon condensate on the
magnetic field strength is derived both for strong and weak fields.
|
[
{
"created": "Wed, 24 Aug 2016 10:30:12 GMT",
"version": "v1"
}
] |
2016-11-21
|
[
[
"Agasian",
"N. O.",
""
]
] |
A treatment is given of the nonperturbative QCD vacuum in a magnetic field. The low-energy equation for the trace of the energy-momentum tensor in a magnetic field is derived. It is shown that the derivatives with respect to a magnetic field of the quark and gluon contributions to the trace of the energy-momentum tensor are equal. The dependence of the gluon condensate on the magnetic field strength is derived both for strong and weak fields.
|
2204.09477
|
Shiyu Wang
|
Junjie Cao, Lei Meng, Liangliang Shang, Shiyu Wang, Bingfang Yang
|
Interpreting the $W$ mass anomaly in the vector-like quark models
|
33 pages, 7 figures. A factor 1/2 is added to Eq. 17 (thanks to the
comments of Dr. S. P. He), all figures are updated, and the conclusions in
the previous version are unchanged. Published in PRD 106 (2022) 5, 055042
| null | null | null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
The new measurement of $W$-boson mass by the CDF collaboration revealed a
remarkable $7\sigma$ disagreement with the Standard Model (SM) prediction. If
confirmed by other experiments, then the disagreement strongly indicates the
existence of new physics beyond the SM. In this work, seven vectorlike quark
(VLQ) extensions of the SM are investigated to interpret the anomaly, and it is
found that three can explain the anomaly in broad parameter space. The
explanations are consistent with the constraints from oblique parameters, the
LHC search for VLQs, the measurements of the properties for the top quark,
bottom quark, and Higgs boson, and the perturbativity criterion. The typical
size of the involved Yukawa coupling is around 1, which is comparable to the
top quark Yukawa coupling in the SM. The other extensions, however, either
predict a negative correction to the mass in reasonable parameter space or
explain the anomaly by unnatural theoretical input parameters.
|
[
{
"created": "Wed, 20 Apr 2022 14:19:27 GMT",
"version": "v1"
},
{
"created": "Thu, 21 Apr 2022 17:37:35 GMT",
"version": "v2"
},
{
"created": "Tue, 12 Jul 2022 12:32:06 GMT",
"version": "v3"
},
{
"created": "Tue, 20 Sep 2022 12:28:16 GMT",
"version": "v4"
},
{
"created": "Tue, 18 Oct 2022 10:42:31 GMT",
"version": "v5"
}
] |
2022-10-19
|
[
[
"Cao",
"Junjie",
""
],
[
"Meng",
"Lei",
""
],
[
"Shang",
"Liangliang",
""
],
[
"Wang",
"Shiyu",
""
],
[
"Yang",
"Bingfang",
""
]
] |
The new measurement of $W$-boson mass by the CDF collaboration revealed a remarkable $7\sigma$ disagreement with the Standard Model (SM) prediction. If confirmed by other experiments, then the disagreement strongly indicates the existence of new physics beyond the SM. In this work, seven vectorlike quark (VLQ) extensions of the SM are investigated to interpret the anomaly, and it is found that three can explain the anomaly in broad parameter space. The explanations are consistent with the constraints from oblique parameters, the LHC search for VLQs, the measurements of the properties for the top quark, bottom quark, and Higgs boson, and the perturbativity criterion. The typical size of the involved Yukawa coupling is around 1, which is comparable to the top quark Yukawa coupling in the SM. The other extensions, however, either predict a negative correction to the mass in reasonable parameter space or explain the anomaly by unnatural theoretical input parameters.
|
1501.04915
|
Mariusz Sadzikowski
|
Leszek Motyka and Mariusz Sadzikowski
|
On relevance of triple gluon fusion in $J/\psi$ hadroproduction
|
20 pp, 9 figures
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
A contribution to $J/\psi$ hadroproduction is analyzed in which the meson
production is mediated by three-gluon partonic state, with two gluons coming
from the target and one gluon from the projectile. This mechanism involves
double gluon density in one of the protons, hence this contribution enters at a
non-leading twist. It is, however, relevant due to an enhancement factor coming
from large double gluon density at small~$x$. We calculate the three-gluon
contribution to $J/\psi$ hadroproduction within perturbative QCD in the
$k_T$-factorization framework. Results are obtained for differential
$p_T$-dependent cross-sections for all $J/\psi$ polarizations and for the sum
over the polarization components. The rescattering contribution is found to
provide a significant correction to the standard leading twist cross-section at
the energies of the Tevatron or the LHC at moderate $p_T$. We suggest $J/\psi$
production in proton-nucleus collision as a possible probe of the triple gluon
mechanism.
|
[
{
"created": "Tue, 20 Jan 2015 18:49:16 GMT",
"version": "v1"
}
] |
2015-01-21
|
[
[
"Motyka",
"Leszek",
""
],
[
"Sadzikowski",
"Mariusz",
""
]
] |
A contribution to $J/\psi$ hadroproduction is analyzed in which the meson production is mediated by three-gluon partonic state, with two gluons coming from the target and one gluon from the projectile. This mechanism involves double gluon density in one of the protons, hence this contribution enters at a non-leading twist. It is, however, relevant due to an enhancement factor coming from large double gluon density at small~$x$. We calculate the three-gluon contribution to $J/\psi$ hadroproduction within perturbative QCD in the $k_T$-factorization framework. Results are obtained for differential $p_T$-dependent cross-sections for all $J/\psi$ polarizations and for the sum over the polarization components. The rescattering contribution is found to provide a significant correction to the standard leading twist cross-section at the energies of the Tevatron or the LHC at moderate $p_T$. We suggest $J/\psi$ production in proton-nucleus collision as a possible probe of the triple gluon mechanism.
|
hep-ph/0409003
|
Xiaofei Zhang
|
George Fai (Kent State University), Jianwei Qiu (Iowa State
University), and Xiaofei Zhang (Kent State University)
|
Probing small-$x$ gluons by low-mass Drell-Yan pairs at colliders
|
25 pages, 16 figures
|
Phys.Rev. C71 (2005) 014901
|
10.1103/PhysRevC.71.014901
| null |
hep-ph
| null |
The transverse-momentum ($Q_T$) distribution of low-mass Drell-Yan pairs is
calculated in QCD perturbation theory with all-order resummation of $\alpha_s
(\alpha_s \ln(Q^2_T/Q^2))^n$ type terms. We demonstrate that the rapidity
distribution of low-mass Drell-Yan pairs at large-enough transverse momentum is
an advantageous source of constraints on the gluon distribution and its nuclear
dependence. We argue that low-mass Drell-Yan pairs in the forward region
provide a good and clean probe of small-$x$ gluons at collider energies.
|
[
{
"created": "Tue, 31 Aug 2004 20:17:57 GMT",
"version": "v1"
}
] |
2009-11-10
|
[
[
"Fai",
"George",
"",
"Kent State University"
],
[
"Qiu",
"Jianwei",
"",
"Iowa State\n University"
],
[
"Zhang",
"Xiaofei",
"",
"Kent State University"
]
] |
The transverse-momentum ($Q_T$) distribution of low-mass Drell-Yan pairs is calculated in QCD perturbation theory with all-order resummation of $\alpha_s (\alpha_s \ln(Q^2_T/Q^2))^n$ type terms. We demonstrate that the rapidity distribution of low-mass Drell-Yan pairs at large-enough transverse momentum is an advantageous source of constraints on the gluon distribution and its nuclear dependence. We argue that low-mass Drell-Yan pairs in the forward region provide a good and clean probe of small-$x$ gluons at collider energies.
|
hep-ph/9911272
| null |
R. N. Mohapatra
|
Supersymmetric Grandunification: An Update
|
77 pages; four figures; Lectures presented at the Trieste summer
school in July, 1999; UMD-PP-00-038; (parts of the article appeared before in
the TASI97 lectures by the author); typos corrected and one reference added
| null | null | null |
hep-ph
| null |
Recent developments in supersymmetric unified theories are reviewed, with
particular emphasis on supersymmetric grand unification and a brief discussion
of recent ideas about extra dimensions.
|
[
{
"created": "Mon, 8 Nov 1999 17:28:51 GMT",
"version": "v1"
},
{
"created": "Thu, 27 Jul 2000 16:47:18 GMT",
"version": "v2"
}
] |
2007-05-23
|
[
[
"Mohapatra",
"R. N.",
""
]
] |
Recent developments in supersymmetric unified theories are reviewed, with particular emphasis on supersymmetric grand unification and a brief discussion of recent ideas about extra dimensions.
|
1608.01643
|
G\'abor B\'ir\'o
|
G\'abor B\'ir\'o and Gergely G\'abor Barnaf\"oldi and Tam\'as S\'andor
Bir\'o and K\'aroly \"Urm\"ossy
|
Application of the Non-extensive Statistical Approach to High Energy
Particle Collisions
| null | null |
10.1063/1.4985366
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In high-energy collisions the number of the created particles is far less
than the thermodynamic limit, especially in small colliding systems (e.g.
proton-proton). Therefore final-state effects and fluctuations in the
one-particle energy distribution are appreciable. As a consequence the
characterization of identified hadron spectra with the Boltzmann\,--\,Gibbs
thermodynamical approach is insufficient. Instead particle spectra measured in
high-energy collisions can be described very well with Tsallis\,--\,Pareto
distributions, derived from non-extensive thermodynamics. Using the Tsallis
q-entropy formula, a generalization of the Boltzmann\,--\,Gibbs entropy, we
interpret the microscopical physics by analysing the Tsallis $q$ and $T$
parameters. In this paper we give a quick overview on these parameters,
analyzing identified hadron spectra from recent years in a wide center of mass
energy range. We demonstrate that the fitted Tsallis-parameters show dependency
on this energy and on the particle species. Our findings are described well by
a QCD inspired evolution ansatz.
|
[
{
"created": "Thu, 4 Aug 2016 18:53:20 GMT",
"version": "v1"
}
] |
2017-06-28
|
[
[
"Bíró",
"Gábor",
""
],
[
"Barnaföldi",
"Gergely Gábor",
""
],
[
"Biró",
"Tamás Sándor",
""
],
[
"Ürmössy",
"Károly",
""
]
] |
In high-energy collisions the number of the created particles is far less than the thermodynamic limit, especially in small colliding systems (e.g. proton-proton). Therefore final-state effects and fluctuations in the one-particle energy distribution are appreciable. As a consequence the characterization of identified hadron spectra with the Boltzmann\,--\,Gibbs thermodynamical approach is insufficient. Instead particle spectra measured in high-energy collisions can be described very well with Tsallis\,--\,Pareto distributions, derived from non-extensive thermodynamics. Using the Tsallis q-entropy formula, a generalization of the Boltzmann\,--\,Gibbs entropy, we interpret the microscopical physics by analysing the Tsallis $q$ and $T$ parameters. In this paper we give a quick overview on these parameters, analyzing identified hadron spectra from recent years in a wide center of mass energy range. We demonstrate that the fitted Tsallis-parameters show dependency on this energy and on the particle species. Our findings are described well by a QCD inspired evolution ansatz.
|
1010.4737
|
Werner Porod
|
Werner Porod
|
LHC phenomenology of supersymmetric models beyond the MSSM
|
Contribution to the 16th International Symposium on Particles,
Strings and Cosmology (PASCOS 2010), Valencia (Spain), July 19-23, 2010
|
J.Phys.Conf.Ser.259:012002,2010
|
10.1088/1742-6596/259/1/012002
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We discuss various phenomenological aspects of supersymmetric models beyond
the MSSM. A particular focus is on models which can correctly explain neutrino
data and the possiblities of LHC to identify the underlying scenario.
|
[
{
"created": "Fri, 22 Oct 2010 15:24:02 GMT",
"version": "v1"
}
] |
2011-01-27
|
[
[
"Porod",
"Werner",
""
]
] |
We discuss various phenomenological aspects of supersymmetric models beyond the MSSM. A particular focus is on models which can correctly explain neutrino data and the possiblities of LHC to identify the underlying scenario.
|
hep-ph/0212128
|
Marty Stock
|
Frank Wilczek
|
Inventory and Outlook of High Energy Physics
|
21 pp., 19 figures; email correspondence to wilczek@mit.edu
|
Nucl.Phys.Proc.Suppl.117:410-430,2003
|
10.1016/S0920-5632(03)01431-2
|
MIT-CTP-3829
|
hep-ph hep-ex hep-th
| null |
Summary talk at ICHEP 2002, Amsterdam, July 2002. I have kept very close to
the content and style of the talk as it was delivered. You may access the
associated PowerPoint presentation through a link at
http://www.ichep02.nl/MainPages/PlenaryProgram.html
|
[
{
"created": "Mon, 9 Dec 2002 20:38:59 GMT",
"version": "v1"
}
] |
2010-11-23
|
[
[
"Wilczek",
"Frank",
""
]
] |
Summary talk at ICHEP 2002, Amsterdam, July 2002. I have kept very close to the content and style of the talk as it was delivered. You may access the associated PowerPoint presentation through a link at http://www.ichep02.nl/MainPages/PlenaryProgram.html
|
1703.00054
|
Dimitrios K. Papoulias
|
T.S. Kosmas, D.K. Papoulias, M. Tortola, J.W.F. Valle
|
Probing light sterile neutrino signatures at reactor and Spallation
Neutron Source neutrino experiments
|
PRD version, 12 pages, 8 figures, updated figures, updated
sensitivity analysis including syst. and stat. uncertainties, updated
references
|
Phys. Rev. D 96, 063013 (2017)
|
10.1103/PhysRevD.96.063013
|
IFIC/17-XXX
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We investigate the impact of a fourth sterile neutrino at reactor and
Spallation Neutron Source neutrino detectors. Specifically, we explore the
discovery potential of the TEXONO and COHERENT experiments to subleading
sterile neutrino effects through the measurement of the coherent elastic
neutrino-nucleus scattering event rate. Our dedicated $\chi^2$-sensitivity
analysis employs realistic nuclear structure calculations adequate for high
purity sub-keV threshold Germanium detectors.
|
[
{
"created": "Tue, 28 Feb 2017 20:54:23 GMT",
"version": "v1"
},
{
"created": "Tue, 19 Sep 2017 09:01:27 GMT",
"version": "v2"
}
] |
2017-09-26
|
[
[
"Kosmas",
"T. S.",
""
],
[
"Papoulias",
"D. K.",
""
],
[
"Tortola",
"M.",
""
],
[
"Valle",
"J. W. F.",
""
]
] |
We investigate the impact of a fourth sterile neutrino at reactor and Spallation Neutron Source neutrino detectors. Specifically, we explore the discovery potential of the TEXONO and COHERENT experiments to subleading sterile neutrino effects through the measurement of the coherent elastic neutrino-nucleus scattering event rate. Our dedicated $\chi^2$-sensitivity analysis employs realistic nuclear structure calculations adequate for high purity sub-keV threshold Germanium detectors.
|
2104.09051
|
Alessandro Morandini
|
Thorben Finke, Michael Kr\"amer, Alessandro Morandini, Alexander
M\"uck, Ivan Oleksiyuk
|
Autoencoders for unsupervised anomaly detection in high energy physics
|
32 pages, 20 figures
|
JHEP 06 (2021) 161
|
10.1007/JHEP06(2021)161
|
TTK-21-12
|
hep-ph cs.LG physics.data-an
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Autoencoders are widely used in machine learning applications, in particular
for anomaly detection. Hence, they have been introduced in high energy physics
as a promising tool for model-independent new physics searches. We scrutinize
the usage of autoencoders for unsupervised anomaly detection based on
reconstruction loss to show their capabilities, but also their limitations. As
a particle physics benchmark scenario, we study the tagging of top jet images
in a background of QCD jet images. Although we reproduce the positive results
from the literature, we show that the standard autoencoder setup cannot be
considered as a model-independent anomaly tagger by inverting the task: due to
the sparsity and the specific structure of the jet images, the autoencoder
fails to tag QCD jets if it is trained on top jets even in a semi-supervised
setup. Since the same autoencoder architecture can be a good tagger for a
specific example of an anomaly and a bad tagger for a different example, we
suggest improved performance measures for the task of model-independent anomaly
detection. We also improve the capability of the autoencoder to learn
non-trivial features of the jet images, such that it is able to achieve both
top jet tagging and the inverse task of QCD jet tagging with the same setup.
However, we want to stress that a truly model-independent and powerful
autoencoder-based unsupervised jet tagger still needs to be developed.
|
[
{
"created": "Mon, 19 Apr 2021 05:06:57 GMT",
"version": "v1"
}
] |
2021-07-15
|
[
[
"Finke",
"Thorben",
""
],
[
"Krämer",
"Michael",
""
],
[
"Morandini",
"Alessandro",
""
],
[
"Mück",
"Alexander",
""
],
[
"Oleksiyuk",
"Ivan",
""
]
] |
Autoencoders are widely used in machine learning applications, in particular for anomaly detection. Hence, they have been introduced in high energy physics as a promising tool for model-independent new physics searches. We scrutinize the usage of autoencoders for unsupervised anomaly detection based on reconstruction loss to show their capabilities, but also their limitations. As a particle physics benchmark scenario, we study the tagging of top jet images in a background of QCD jet images. Although we reproduce the positive results from the literature, we show that the standard autoencoder setup cannot be considered as a model-independent anomaly tagger by inverting the task: due to the sparsity and the specific structure of the jet images, the autoencoder fails to tag QCD jets if it is trained on top jets even in a semi-supervised setup. Since the same autoencoder architecture can be a good tagger for a specific example of an anomaly and a bad tagger for a different example, we suggest improved performance measures for the task of model-independent anomaly detection. We also improve the capability of the autoencoder to learn non-trivial features of the jet images, such that it is able to achieve both top jet tagging and the inverse task of QCD jet tagging with the same setup. However, we want to stress that a truly model-independent and powerful autoencoder-based unsupervised jet tagger still needs to be developed.
|
hep-ph/0307224
|
Srubabati Goswami
|
Srubabati Goswami
|
Solar Neutrino Oscillation Phenomenology
|
12 pages, Plenary talk at 9th International Symposium on Particles,
Strings and Cosmology (PASCOS 03), Mumbai, India, 3-8 Jan 2003
|
Pramana62:241-254,2004
|
10.1007/BF02705086
| null |
hep-ph
| null |
This article summarises the status of the solar neutrino oscillation
phenomenology at the end of 2002 in the light of the SNO and KamLAND results.
We first present the allowed areas obtained from global solar analysis and
demonstrate the preference of the solar data towards the Large-Mixing-Angle
(LMA) MSW solution. A clear confirmation in favor of the LMA solution comes
from the \kl reactor neutrino data. The \kl spectral data in conjunction with
the global solar data further narrows down the allowed LMA region and splits it
into two allowed zones -- a low $\Delta m^2$ region (low-LMA) and high $\Delta
m^2$ region (high-LMA). We demonstrate through a projected analysis that with
an exposure of 3 kton-year (kTy) \kl can remove this ambiguity.
|
[
{
"created": "Thu, 17 Jul 2003 17:53:57 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Goswami",
"Srubabati",
""
]
] |
This article summarises the status of the solar neutrino oscillation phenomenology at the end of 2002 in the light of the SNO and KamLAND results. We first present the allowed areas obtained from global solar analysis and demonstrate the preference of the solar data towards the Large-Mixing-Angle (LMA) MSW solution. A clear confirmation in favor of the LMA solution comes from the \kl reactor neutrino data. The \kl spectral data in conjunction with the global solar data further narrows down the allowed LMA region and splits it into two allowed zones -- a low $\Delta m^2$ region (low-LMA) and high $\Delta m^2$ region (high-LMA). We demonstrate through a projected analysis that with an exposure of 3 kton-year (kTy) \kl can remove this ambiguity.
|
2304.08118
|
Christoph Englert
|
Spyros Argyropoulos, Clare Burrage, Christoph Englert
|
Environmentally aware displaced vertices
|
6 pages, 3 figures
| null | null | null |
hep-ph hep-ex
|
http://creativecommons.org/licenses/by/4.0/
|
Dynamical theories of dark energy predict new degrees of freedom with
particular environmental sensitivity to avoid constraints on fifth forces. We
show that the similar, yet complementary multi-purpose detector setup of the
ATLAS and CMS experiments provides a unique opportunity to place sensitivity on
such scenarios in a narrow, yet relevant parameter range. Furthermore, our
investigation gives rise to a novel phenomenological signature that the LHC
experiments can pursue to exploit their complementary detector design from a
BSM perspective.
|
[
{
"created": "Mon, 17 Apr 2023 09:52:52 GMT",
"version": "v1"
}
] |
2023-04-18
|
[
[
"Argyropoulos",
"Spyros",
""
],
[
"Burrage",
"Clare",
""
],
[
"Englert",
"Christoph",
""
]
] |
Dynamical theories of dark energy predict new degrees of freedom with particular environmental sensitivity to avoid constraints on fifth forces. We show that the similar, yet complementary multi-purpose detector setup of the ATLAS and CMS experiments provides a unique opportunity to place sensitivity on such scenarios in a narrow, yet relevant parameter range. Furthermore, our investigation gives rise to a novel phenomenological signature that the LHC experiments can pursue to exploit their complementary detector design from a BSM perspective.
|
1303.7320
|
Brian Feldstein
|
Brian Feldstein, Alexander Kusenko, Shigeki Matsumoto and Tsutomu T.
Yanagida
|
Neutrinos at IceCube from Heavy Decaying Dark Matter
|
18 pages, 1 figure; v2: footnote concerning electroweak
bremsstrahlung added
| null |
10.1103/PhysRevD.88.015004
| null |
hep-ph astro-ph.HE
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
A monochromatic line in the cosmic neutrino spectrum would be a smoking gun
signature of dark matter. It is intriguing that the IceCube experiment has
recently reported two PeV neutrino events with energies that may be equal up to
experimental uncertainties, and which have a probability of being a background
fluctuation estimated to be less than a percent. Here we explore prospects for
these events to be the first indication of a monochromatic line signal from
dark matter. While measurable annihilation signatures would seem to be
impossible at such energies, we discuss the dark matter quantum numbers,
effective operators, and lifetimes which could lead to an appropriate signal
from dark matter decays. We will show that the set of possible decay operators
is rather constrained, and will focus on several viable candidates which could
explain the IceCube events; R-parity violating gravitinos, hidden sector gauge
bosons, and singlet fermions in an extra dimension. In essentially all cases we
find that a PeV neutrino line signal from dark matter would be accompanied by a
potentially observable continuum spectrum of neutrinos rising towards lower
energies.
|
[
{
"created": "Fri, 29 Mar 2013 07:54:21 GMT",
"version": "v1"
},
{
"created": "Fri, 14 Jun 2013 05:57:56 GMT",
"version": "v2"
}
] |
2013-10-30
|
[
[
"Feldstein",
"Brian",
""
],
[
"Kusenko",
"Alexander",
""
],
[
"Matsumoto",
"Shigeki",
""
],
[
"Yanagida",
"Tsutomu T.",
""
]
] |
A monochromatic line in the cosmic neutrino spectrum would be a smoking gun signature of dark matter. It is intriguing that the IceCube experiment has recently reported two PeV neutrino events with energies that may be equal up to experimental uncertainties, and which have a probability of being a background fluctuation estimated to be less than a percent. Here we explore prospects for these events to be the first indication of a monochromatic line signal from dark matter. While measurable annihilation signatures would seem to be impossible at such energies, we discuss the dark matter quantum numbers, effective operators, and lifetimes which could lead to an appropriate signal from dark matter decays. We will show that the set of possible decay operators is rather constrained, and will focus on several viable candidates which could explain the IceCube events; R-parity violating gravitinos, hidden sector gauge bosons, and singlet fermions in an extra dimension. In essentially all cases we find that a PeV neutrino line signal from dark matter would be accompanied by a potentially observable continuum spectrum of neutrinos rising towards lower energies.
|
1812.07004
|
Shohei Okawa
|
Junichiro Kawamura, Shohei Okawa, Yuji Omura, Yong Tang
|
WIMP dark matter in the parity solution to the strong CP problem
|
35 pages, 5 figures, v2: references added, version published in JHEP
|
JHEP 1904 (2019) 162
|
10.1007/JHEP04(2019)162
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We extend the Standard Model (SM) with parity symmetry, motivated by the
strong CP problem and dark matter. In our model, parity symmetry is conserved
at high energy by introducing a mirror sector with the extra gauge symmetry, $
SU(2)_R \times U(1)_R$. The charges of $SU(2)_R \times U(1)_R$ are assigned to
the mirror fields in the same way as in the SM, but the chiralities of the
mirror fermions are opposite to respect the parity symmetry. The strong CP
problem is resolved, since the mirror quarks are also charged under the
$SU(3)_c$ in the SM. In the minimal setup, the mirror gauge symmetry leads to
stable colored particles which would be inconsistent with the observed data, so
that we introduce two scalars in order to deplete the stable colored particles.
Interestingly, one of the scalars becomes stable because of the gauge symmetry
and therefore can be a good dark matter candidate. We especially study the
phenomenology relevant to the dark matter, i.e. thermal relic density, direct
and indirect searches for the dark matter. The bounds from the LHC experiment
and the Landau pole are also taken into account. As a result, we find that a
limited region is viable: the mirror up quark mass is around [600\,GeV, 3\,TeV]
and the relative mass difference between the dark matter and the mirror up
quark or electron is about ${\cal O}$(1-10\,\%). We also discuss the neutrino
sector and show that the right-handed neutrinos in the mirror sector can
increase the effective number of neutrinos or dark radiation by $0.14$.
|
[
{
"created": "Mon, 17 Dec 2018 19:05:26 GMT",
"version": "v1"
},
{
"created": "Tue, 14 May 2019 02:20:44 GMT",
"version": "v2"
}
] |
2019-05-15
|
[
[
"Kawamura",
"Junichiro",
""
],
[
"Okawa",
"Shohei",
""
],
[
"Omura",
"Yuji",
""
],
[
"Tang",
"Yong",
""
]
] |
We extend the Standard Model (SM) with parity symmetry, motivated by the strong CP problem and dark matter. In our model, parity symmetry is conserved at high energy by introducing a mirror sector with the extra gauge symmetry, $ SU(2)_R \times U(1)_R$. The charges of $SU(2)_R \times U(1)_R$ are assigned to the mirror fields in the same way as in the SM, but the chiralities of the mirror fermions are opposite to respect the parity symmetry. The strong CP problem is resolved, since the mirror quarks are also charged under the $SU(3)_c$ in the SM. In the minimal setup, the mirror gauge symmetry leads to stable colored particles which would be inconsistent with the observed data, so that we introduce two scalars in order to deplete the stable colored particles. Interestingly, one of the scalars becomes stable because of the gauge symmetry and therefore can be a good dark matter candidate. We especially study the phenomenology relevant to the dark matter, i.e. thermal relic density, direct and indirect searches for the dark matter. The bounds from the LHC experiment and the Landau pole are also taken into account. As a result, we find that a limited region is viable: the mirror up quark mass is around [600\,GeV, 3\,TeV] and the relative mass difference between the dark matter and the mirror up quark or electron is about ${\cal O}$(1-10\,\%). We also discuss the neutrino sector and show that the right-handed neutrinos in the mirror sector can increase the effective number of neutrinos or dark radiation by $0.14$.
|
1503.03450
|
Maarten F. L. Golterman
|
Diogo Boito, Anthony Francis, Maarten Golterman, Renwick Hudspith,
Randy Lewis, Kim Maltman, Santiago Peris
|
Low-energy constants and condensates from ALEPH hadronic $\tau$ decay
data
|
16 pages, revtex
|
Phys. Rev. D 92, 114501 (2015)
|
10.1103/PhysRevD.92.114501
| null |
hep-ph hep-lat
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We determine the NLO chiral low-energy constant $L_{10}^r$, and combinations
$C_{12}^r\pm C_{61}^r+C_{80}^r$, $C_{13}^r-C_{62}^r+C_{81}^r$, $C_{61}^r$, and
$C_{87}^r$, of the NNLO chiral low-energy constants incorporating recently
revised ALEPH results for the non-strange vector ($V$) and axial-vector ($A$)
hadronic $\tau$ decay distributions and recently updated RBC/UKQCD lattice data
for the non-strange $V-A$ two-point function. In the $\bar{\rm MS}$ scheme, at
renormalization scale $\mu=770\ {MeV}$, we find $L_{10}^r=-0.00350(17)$,
$C_{12}^r+C_{61}^r+C_{80}^r=0.00237(16)\ {GeV}^{-2}$,
$C_{12}^r-C_{61}^r+C_{80}^r=-0.00056(15)\ {GeV}^{-2}$,
$C_{13}^r-C_{62}^r+C_{81}^r=0.00046(9)\ {GeV}^{-2}$, $C_{61}^r=0.00146(15)\
{GeV}^{-2}$, and $C_{87}^r=0.00510(22)\ {GeV}^{-2}$. With errors here at or
below the level expected for contributions of yet higher order in the chiral
expansion, the analysis exhausts the possibilities of what can be meaningfully
achieved in an NNLO analysis. We also consider the dimension six and dimension
eight coefficients in the operator product expansion in the $V-A$ channel.
|
[
{
"created": "Wed, 11 Mar 2015 19:03:14 GMT",
"version": "v1"
}
] |
2015-12-09
|
[
[
"Boito",
"Diogo",
""
],
[
"Francis",
"Anthony",
""
],
[
"Golterman",
"Maarten",
""
],
[
"Hudspith",
"Renwick",
""
],
[
"Lewis",
"Randy",
""
],
[
"Maltman",
"Kim",
""
],
[
"Peris",
"Santiago",
""
]
] |
We determine the NLO chiral low-energy constant $L_{10}^r$, and combinations $C_{12}^r\pm C_{61}^r+C_{80}^r$, $C_{13}^r-C_{62}^r+C_{81}^r$, $C_{61}^r$, and $C_{87}^r$, of the NNLO chiral low-energy constants incorporating recently revised ALEPH results for the non-strange vector ($V$) and axial-vector ($A$) hadronic $\tau$ decay distributions and recently updated RBC/UKQCD lattice data for the non-strange $V-A$ two-point function. In the $\bar{\rm MS}$ scheme, at renormalization scale $\mu=770\ {MeV}$, we find $L_{10}^r=-0.00350(17)$, $C_{12}^r+C_{61}^r+C_{80}^r=0.00237(16)\ {GeV}^{-2}$, $C_{12}^r-C_{61}^r+C_{80}^r=-0.00056(15)\ {GeV}^{-2}$, $C_{13}^r-C_{62}^r+C_{81}^r=0.00046(9)\ {GeV}^{-2}$, $C_{61}^r=0.00146(15)\ {GeV}^{-2}$, and $C_{87}^r=0.00510(22)\ {GeV}^{-2}$. With errors here at or below the level expected for contributions of yet higher order in the chiral expansion, the analysis exhausts the possibilities of what can be meaningfully achieved in an NNLO analysis. We also consider the dimension six and dimension eight coefficients in the operator product expansion in the $V-A$ channel.
|
1703.08457
|
M. N. Rebelo
|
D. Emmanuel-Costa, O. M. Ogreid, P. Osland and M. N. Rebelo
|
Spontaneous symmetry breaking in three-Higgs-doublet $S_3$-symmetric
models
|
11 pages, no figures. Prepared for the proceedings of DISCRETE2016:
the Fifth Symposium on Prospects in the Physics of Discrete Symmetries, 28
November-3 December 2016, University of Warsaw, Poland, to appear in the
Journal of Physics: Conference Series (JPCS)
| null |
10.1088/1742-6596/873/1/012007
|
CERN-TH-2017-070
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The talk summarises work done by the authors consisting of a detailed study
of the possible vacua in models with three Higgs doublets with $S_3$ symmetry
and without explicit CP violation. Different vacua require special regions of
the parameter space which were analysed in our work. We establish the
possibility of spontaneous CP violation in this framework and we also show
which complex vacua conserve CP. In our work we discussed constraints from
vacuum stability. The results presented here are relevant for model building.
|
[
{
"created": "Fri, 24 Mar 2017 15:19:25 GMT",
"version": "v1"
}
] |
2017-09-13
|
[
[
"Emmanuel-Costa",
"D.",
""
],
[
"Ogreid",
"O. M.",
""
],
[
"Osland",
"P.",
""
],
[
"Rebelo",
"M. N.",
""
]
] |
The talk summarises work done by the authors consisting of a detailed study of the possible vacua in models with three Higgs doublets with $S_3$ symmetry and without explicit CP violation. Different vacua require special regions of the parameter space which were analysed in our work. We establish the possibility of spontaneous CP violation in this framework and we also show which complex vacua conserve CP. In our work we discussed constraints from vacuum stability. The results presented here are relevant for model building.
|
1212.4508
|
Gabriel Lee
|
Richard J. Hill, Gabriel Lee, Gil Paz, and Mikhail P. Solon
|
The NRQED lagrangian at order 1/M^4
|
21 pages, 3 figures
| null |
10.1103/PhysRevD.87.053017
|
EFI Preprint 12-8
|
hep-ph hep-lat nucl-th physics.atom-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The parity and time-reversal invariant effective lagrangian for a heavy
fermion interacting with an abelian gauge field, i.e., NRQED, is constructed
through order $1/M^4$. The implementation of Lorentz invariance in the
effective theory becomes nontrivial at this order, and a complete solution for
Wilson coefficient constraints is obtained. Matching conditions in the
one-fermion sector are presented in terms of form factors and two-photon matrix
elements of the nucleon. The extension of NRQED to describe interactions of the
heavy fermion with a light fermion is introduced. Sample applications are
discussed; these include the computation of nuclear structure effects in atomic
bound states, the model-independent analysis of radiative corrections to
low-energy lepton-nucleon scattering, and the study of static electromagnetic
properties of nucleons.
|
[
{
"created": "Tue, 18 Dec 2012 21:17:33 GMT",
"version": "v1"
},
{
"created": "Thu, 21 Mar 2013 14:04:49 GMT",
"version": "v2"
}
] |
2013-04-03
|
[
[
"Hill",
"Richard J.",
""
],
[
"Lee",
"Gabriel",
""
],
[
"Paz",
"Gil",
""
],
[
"Solon",
"Mikhail P.",
""
]
] |
The parity and time-reversal invariant effective lagrangian for a heavy fermion interacting with an abelian gauge field, i.e., NRQED, is constructed through order $1/M^4$. The implementation of Lorentz invariance in the effective theory becomes nontrivial at this order, and a complete solution for Wilson coefficient constraints is obtained. Matching conditions in the one-fermion sector are presented in terms of form factors and two-photon matrix elements of the nucleon. The extension of NRQED to describe interactions of the heavy fermion with a light fermion is introduced. Sample applications are discussed; these include the computation of nuclear structure effects in atomic bound states, the model-independent analysis of radiative corrections to low-energy lepton-nucleon scattering, and the study of static electromagnetic properties of nucleons.
|
2401.12304
|
Fulvia De Fazio
|
Pietro Colangelo, Fulvia De Fazio, Francesco Loparco, Nicola Losacco
|
New Physics couplings from angular coefficient functions of $\bar B \to
D^* (D \pi) \ell \bar \nu_\ell$
|
RevTex, 8 pages, 6 figures. Added clarifications and references.
Matches the published version
| null | null |
BARI-TH/754-24
|
hep-ph hep-ex hep-lat
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The Belle Collaboration has recently measured the complete set of angular
coefficient functions for the exclusive decays $\bar B \to D^* (D \pi) \ell
\bar \nu_\ell$, with $\ell=e,\,\mu$, in four bins of the parameter
$w=\displaystyle\frac{m_B^2+m_{D^*}^2-q^2}{2m_B m_{D^*}}$, with $q$ the lepton
pair momentum. Under the assumption that physics beyond the Standard Model does
not contribute to such modes, the measurements are useful to determine the
hadronic form factors describing the $B \to D^*$ matrix elements of the
Standard Model weak current, and to improve the determination of $|V_{cb}|$. On
the other hand, they can be used to assess the impact of possible new physics
contributions. In a bottom-up approach, we extend the Standard Model effective
Hamiltonian governing this mode with the inclusion of the full set of Lorentz
invariant d=6 operators compatible with the gauge symmetry of the theory. The
measured angular coefficient functions can tightly constrain the couplings in
the generalized Hamiltonian. We present the first results of this analysis,
discussing how improvements can be achieved when more complete data on the
angular coefficient functions will be available.
|
[
{
"created": "Mon, 22 Jan 2024 19:02:30 GMT",
"version": "v1"
},
{
"created": "Thu, 25 Apr 2024 14:46:25 GMT",
"version": "v2"
}
] |
2024-04-26
|
[
[
"Colangelo",
"Pietro",
""
],
[
"De Fazio",
"Fulvia",
""
],
[
"Loparco",
"Francesco",
""
],
[
"Losacco",
"Nicola",
""
]
] |
The Belle Collaboration has recently measured the complete set of angular coefficient functions for the exclusive decays $\bar B \to D^* (D \pi) \ell \bar \nu_\ell$, with $\ell=e,\,\mu$, in four bins of the parameter $w=\displaystyle\frac{m_B^2+m_{D^*}^2-q^2}{2m_B m_{D^*}}$, with $q$ the lepton pair momentum. Under the assumption that physics beyond the Standard Model does not contribute to such modes, the measurements are useful to determine the hadronic form factors describing the $B \to D^*$ matrix elements of the Standard Model weak current, and to improve the determination of $|V_{cb}|$. On the other hand, they can be used to assess the impact of possible new physics contributions. In a bottom-up approach, we extend the Standard Model effective Hamiltonian governing this mode with the inclusion of the full set of Lorentz invariant d=6 operators compatible with the gauge symmetry of the theory. The measured angular coefficient functions can tightly constrain the couplings in the generalized Hamiltonian. We present the first results of this analysis, discussing how improvements can be achieved when more complete data on the angular coefficient functions will be available.
|
1405.3083
|
Michael Klasen
|
M. Klasen, C. Klein-B\"osing, K. Kovarik, G. Kramer, M. Topp, J.
Wessels
|
NLO Monte Carlo predictions for heavy-quark production at the LHC: pp
collisions in ALICE
|
19 pages, 7 figures
| null |
10.1007/JHEP08(2014)109
|
DESY 14-074, MS-TP-14-21
|
hep-ph nucl-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Next-to-leading order (NLO) QCD predictions for the production of heavy
quarks in proton-proton collisions are presented within three different
approaches to quark mass, resummation and fragmentation effects. In particular,
new NLO and parton shower simulations with POWHEG are performed in the ALICE
kinematic regime at three different centre-of-mass energies, including scale
and parton density variations, in order to establish a reliable baseline for
future detailed studies of heavy-quark suppression in heavy-ion collisions.
Very good agreement of POWHEG is found with FONLL, in particular for centrally
produced D^0, D^+ and D^*+ mesons and electrons from charm and bottom quark
decays, but also with the generally somewhat higher GM-VFNS predictions within
the theoretical uncertainties. The latter are dominated by scale rather than
quark mass variations. Parton density uncertainties for charm and bottom quark
production are computed here with POWHEG for the first time and shown to be
dominant in the forward regime, e.g. for muons coming from heavy-flavour
decays. The fragmentation into D_s^+ mesons seems to require further tuning
within the NLO Monte Carlo approach.
|
[
{
"created": "Tue, 13 May 2014 10:00:53 GMT",
"version": "v1"
}
] |
2015-06-19
|
[
[
"Klasen",
"M.",
""
],
[
"Klein-Bösing",
"C.",
""
],
[
"Kovarik",
"K.",
""
],
[
"Kramer",
"G.",
""
],
[
"Topp",
"M.",
""
],
[
"Wessels",
"J.",
""
]
] |
Next-to-leading order (NLO) QCD predictions for the production of heavy quarks in proton-proton collisions are presented within three different approaches to quark mass, resummation and fragmentation effects. In particular, new NLO and parton shower simulations with POWHEG are performed in the ALICE kinematic regime at three different centre-of-mass energies, including scale and parton density variations, in order to establish a reliable baseline for future detailed studies of heavy-quark suppression in heavy-ion collisions. Very good agreement of POWHEG is found with FONLL, in particular for centrally produced D^0, D^+ and D^*+ mesons and electrons from charm and bottom quark decays, but also with the generally somewhat higher GM-VFNS predictions within the theoretical uncertainties. The latter are dominated by scale rather than quark mass variations. Parton density uncertainties for charm and bottom quark production are computed here with POWHEG for the first time and shown to be dominant in the forward regime, e.g. for muons coming from heavy-flavour decays. The fragmentation into D_s^+ mesons seems to require further tuning within the NLO Monte Carlo approach.
|
hep-ph/0203090
|
Shinya Kanemura
|
Hong-Jian He, Shinya Kanemura, C.-P. Yuan
|
Determining the Chirality of Yukawa Couplings via Single Charged Higgs
Boson Production in Polarized Photon Collision
|
Version accepted by Physical Review Letters (references added, minor
rewording, RevTex4)
|
Phys.Rev.Lett. 89 (2002) 101803
|
10.1103/PhysRevLett.89.101803
| null |
hep-ph hep-ex
| null |
When the charged Higgs boson is too heavy to be produced in pairs, the
predominant production mechanism at Linear Colliders is via the single charged
Higgs boson production processes, such as $e^-e^+ \to b \bar c H^+, \tau \bar
\nu H^+$ and $\gamma\gamma \to b \bar c H^+, \tau \bar \nu H^+$. We show that
the yield of a heavy charged Higgs boson at a $\gamma\gamma$ collider is
typically one or two orders of magnitude larger than that at an $e^-e^+$
collider. Furthermore, a polarized $\gamma\gamma$ collider can determine the
chirality of the Yukawa couplings of fermions with charged Higgs boson via
single charged Higgs boson production, and thus discriminate models of new
physics.
|
[
{
"created": "Fri, 8 Mar 2002 19:10:24 GMT",
"version": "v1"
},
{
"created": "Wed, 31 Jul 2002 03:14:06 GMT",
"version": "v2"
}
] |
2009-11-07
|
[
[
"He",
"Hong-Jian",
""
],
[
"Kanemura",
"Shinya",
""
],
[
"Yuan",
"C. -P.",
""
]
] |
When the charged Higgs boson is too heavy to be produced in pairs, the predominant production mechanism at Linear Colliders is via the single charged Higgs boson production processes, such as $e^-e^+ \to b \bar c H^+, \tau \bar \nu H^+$ and $\gamma\gamma \to b \bar c H^+, \tau \bar \nu H^+$. We show that the yield of a heavy charged Higgs boson at a $\gamma\gamma$ collider is typically one or two orders of magnitude larger than that at an $e^-e^+$ collider. Furthermore, a polarized $\gamma\gamma$ collider can determine the chirality of the Yukawa couplings of fermions with charged Higgs boson via single charged Higgs boson production, and thus discriminate models of new physics.
|
hep-ph/0204059
|
Ernest Ma
|
Ernest Ma (UC Riverside)
|
New Perspective on Fermion Mass Matrices
|
revised version to appear in PLB
|
Phys.Lett. B541 (2002) 288-290
|
10.1016/S0370-2693(02)02229-3
|
UCRHEP-T335 (April 2002)
|
hep-ph
| null |
It is shown that any $n \times n$ Dirac fermion mass matrix may be written as
the sum of $n$ states of equal ``mass''. However, these states are in general
not orthogonal. Thus the texture of any such fermion mass matrix may be
understood as the nonzero overlap among these states.
|
[
{
"created": "Thu, 4 Apr 2002 21:11:33 GMT",
"version": "v1"
},
{
"created": "Mon, 1 Jul 2002 18:13:41 GMT",
"version": "v2"
}
] |
2009-11-07
|
[
[
"Ma",
"Ernest",
"",
"UC Riverside"
]
] |
It is shown that any $n \times n$ Dirac fermion mass matrix may be written as the sum of $n$ states of equal ``mass''. However, these states are in general not orthogonal. Thus the texture of any such fermion mass matrix may be understood as the nonzero overlap among these states.
|
hep-ph/0009155
|
Joaquim Prades
|
Johan Bijnens and Joaquim Prades
|
Epsilon'/Epsilon in the Chiral Limit using Large N_c
|
Talk given by J.B. at Chiral Dynamics 2000, 17-22 July, Jefferson
Lab, Newport News, VA, USA. Three pages, uses ws-p8-50x6-00.cls
| null |
10.1142/9789812810977_0028
| null |
hep-ph
| null |
The K to pi pi system is analyzed in the chiral limit and at NLO in 1/N_c.
The Delta I = 1/2 rule is reproduced and we obtain a large value for epsilon' /
epsilon.
|
[
{
"created": "Wed, 13 Sep 2000 16:25:58 GMT",
"version": "v1"
}
] |
2017-08-23
|
[
[
"Bijnens",
"Johan",
""
],
[
"Prades",
"Joaquim",
""
]
] |
The K to pi pi system is analyzed in the chiral limit and at NLO in 1/N_c. The Delta I = 1/2 rule is reproduced and we obtain a large value for epsilon' / epsilon.
|
2303.12204
|
Karol Kolodziej
|
Karol Kolodziej
|
PSGen, a generator of phase space parameterizations for the multichannel
Monte Carlo integration
|
11 pages, the version to be published in Comput. Phys. Commun
| null | null | null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
PSGen is a new general purpose Fortran program which has been written to
facilitate the Monte Carlo phase space integration of the S matrix element of
any 2 -> n scattering process, with n=2,...,9, provided by the user. The
program is written in Fortran 90/95. It uses a new very fast algorithm that
automatically generates calls to Fortran subroutines containing different phase
space parameterizations of the considered class of processes.The
parameterizations take into account mappings of poles due to the Feynman
propagators of unstable heavy particles decaying into 2 or 3 on shell final
state particles according to predefined patterns, possible single or double
$t$-channel poles and peaks due to one on shell photon or gluon radiation. The
individual subroutines are organized in a single multichannel kinematics
subroutine which can be easily called while computing the phase space integral
of the S matrix element as a function of generated particle four momenta, in
either the leading or higher orders of the perturbation series. The particle
four momenta can be used in a quadruple precision version, if necessary.
|
[
{
"created": "Tue, 21 Mar 2023 21:39:11 GMT",
"version": "v1"
},
{
"created": "Mon, 4 Sep 2023 15:51:03 GMT",
"version": "v2"
}
] |
2023-09-06
|
[
[
"Kolodziej",
"Karol",
""
]
] |
PSGen is a new general purpose Fortran program which has been written to facilitate the Monte Carlo phase space integration of the S matrix element of any 2 -> n scattering process, with n=2,...,9, provided by the user. The program is written in Fortran 90/95. It uses a new very fast algorithm that automatically generates calls to Fortran subroutines containing different phase space parameterizations of the considered class of processes.The parameterizations take into account mappings of poles due to the Feynman propagators of unstable heavy particles decaying into 2 or 3 on shell final state particles according to predefined patterns, possible single or double $t$-channel poles and peaks due to one on shell photon or gluon radiation. The individual subroutines are organized in a single multichannel kinematics subroutine which can be easily called while computing the phase space integral of the S matrix element as a function of generated particle four momenta, in either the leading or higher orders of the perturbation series. The particle four momenta can be used in a quadruple precision version, if necessary.
|
hep-ph/0111463
|
Jerome Damet
|
J.Damet (Uppsala University), G.Ingelman (Uppsala University & DESY),
C. B. Mariotto (IF-UFRGS & Uppsala University)
|
Prompt J/psi production at the LHC
|
8 pages, 8 eps figures
|
JHEP 0209:014,2002
|
10.1088/1126-6708/2002/09/014
|
TSL/ISV-2001-0243
|
hep-ph
| null |
Models with essential non-perturbative QCD dynamics for the production of
charmonium are extrapolated to give predictions of prompt J/psi production at
the LHC. Differences of up to an order of magnitude occurs, although the
different models all describe the Tevatron data on high-pT charmonium. An
important point is here the treatment of higher order perturbative QCD effects.
We also discuss the large rate of prompt J/psi from these models as a
background to CP violation studies.
|
[
{
"created": "Fri, 30 Nov 2001 13:16:48 GMT",
"version": "v1"
},
{
"created": "Wed, 16 Oct 2002 12:37:44 GMT",
"version": "v2"
}
] |
2011-03-23
|
[
[
"Damet",
"J.",
"",
"Uppsala University"
],
[
"Ingelman",
"G.",
"",
"Uppsala University & DESY"
],
[
"Mariotto",
"C. B.",
"",
"IF-UFRGS & Uppsala University"
]
] |
Models with essential non-perturbative QCD dynamics for the production of charmonium are extrapolated to give predictions of prompt J/psi production at the LHC. Differences of up to an order of magnitude occurs, although the different models all describe the Tevatron data on high-pT charmonium. An important point is here the treatment of higher order perturbative QCD effects. We also discuss the large rate of prompt J/psi from these models as a background to CP violation studies.
|
hep-ph/9606321
|
Sibaji Raha
|
Abhijit Bhattacharyya, Jan-e Alam, Sibaji Raha and Bikash Sinha
|
Can Dilepton Suppression be seen in Heavy Ion Experiments ?
|
Latex file (figures included)
| null | null | null |
hep-ph
| null |
Effects of finite temperature correction to the dilepton emission rate in
ultrarelativistic heavy ion collisions have been looked into. It has been seen
that although the $\rho$-peak in the dilepton spectra from the hadronic sector
is suppressed at very high temperatures, almost no effect can be observed in
the space time integrated count rate.
|
[
{
"created": "Thu, 13 Jun 1996 15:51:00 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Bhattacharyya",
"Abhijit",
""
],
[
"Alam",
"Jan-e",
""
],
[
"Raha",
"Sibaji",
""
],
[
"Sinha",
"Bikash",
""
]
] |
Effects of finite temperature correction to the dilepton emission rate in ultrarelativistic heavy ion collisions have been looked into. It has been seen that although the $\rho$-peak in the dilepton spectra from the hadronic sector is suppressed at very high temperatures, almost no effect can be observed in the space time integrated count rate.
|
hep-ph/9806491
|
Keh-Fei Liu
|
K.F. Liu, S.J. Dong, T. Draper, D. Leinweber, J. Sloan, W. Wilcox, and
R. M. Woloshyn
|
Valence QCD: Connecting QCD to the Quark Model
|
68 pages, LaTex, 36 postscript figures including 1 color figure
|
Phys.Rev.D59:112001,1999
|
10.1103/PhysRevD.59.112001
|
UK/98-03
|
hep-ph hep-lat nucl-th
| null |
A valence QCD theory is developed to study the valence quark properties of
hadrons. To keep only the valence degrees of freedom, the pair creation through
the Z graphs is deleted in the connected insertions; whereas, the sea quarks
are eliminated in the disconnected insertions. This is achieved with a new
``valence QCD'' lagrangian where the action in the time direction is modified
so that the particle and antiparticle decouple. The theory has the vector and
axial $U(2N_F)$ symmetry in the particle-antiparticle space. Through lattice
simulation, it appears that this is dynamically broken down to $U_q(N_F) \times
U_{\bar{q}}(N_F)$. Furthermore, the lattice simulation reveals spin degeneracy
in the hadron masses and SU(6) relations in the ratios of $F_A/D_A, F_S/D_S$,
and $\mu^n/\mu^p$. This leads to an approximate $U_q(2N_F) \times
U_{\bar{q}}(2N_F)$ symmetry which is the basis for the valence quark model. We
find that the masses of N, $\Delta, \rho, \pi, a_1$, and $a_0$ all drop
precipitously compared to their counterparts in the quenched QCD calculation.
This is interpreted as due to the disapperance of the `constituent' quark mass
which is dynamically generated through tadpole diagrams. Form the near
degeneracy between N and $\Delta$ for the quark masses we have studied (ranging
from one to four times the strange mass), we conclude that the origin of the
hyper-fine splitting in the baryon is largely attibuted to the Goldstone boson
exchanges between the quarks. These are the consequences of lacking chiral
symmetry in valence QCD. We discuss its implication on the models of hadrons.
|
[
{
"created": "Fri, 26 Jun 1998 03:07:53 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Liu",
"K. F.",
""
],
[
"Dong",
"S. J.",
""
],
[
"Draper",
"T.",
""
],
[
"Leinweber",
"D.",
""
],
[
"Sloan",
"J.",
""
],
[
"Wilcox",
"W.",
""
],
[
"Woloshyn",
"R. M.",
""
]
] |
A valence QCD theory is developed to study the valence quark properties of hadrons. To keep only the valence degrees of freedom, the pair creation through the Z graphs is deleted in the connected insertions; whereas, the sea quarks are eliminated in the disconnected insertions. This is achieved with a new ``valence QCD'' lagrangian where the action in the time direction is modified so that the particle and antiparticle decouple. The theory has the vector and axial $U(2N_F)$ symmetry in the particle-antiparticle space. Through lattice simulation, it appears that this is dynamically broken down to $U_q(N_F) \times U_{\bar{q}}(N_F)$. Furthermore, the lattice simulation reveals spin degeneracy in the hadron masses and SU(6) relations in the ratios of $F_A/D_A, F_S/D_S$, and $\mu^n/\mu^p$. This leads to an approximate $U_q(2N_F) \times U_{\bar{q}}(2N_F)$ symmetry which is the basis for the valence quark model. We find that the masses of N, $\Delta, \rho, \pi, a_1$, and $a_0$ all drop precipitously compared to their counterparts in the quenched QCD calculation. This is interpreted as due to the disapperance of the `constituent' quark mass which is dynamically generated through tadpole diagrams. Form the near degeneracy between N and $\Delta$ for the quark masses we have studied (ranging from one to four times the strange mass), we conclude that the origin of the hyper-fine splitting in the baryon is largely attibuted to the Goldstone boson exchanges between the quarks. These are the consequences of lacking chiral symmetry in valence QCD. We discuss its implication on the models of hadrons.
|
hep-ph/9711429
|
Hong-Jian He
|
T. Han (Wisconsin & Davis), H.-J. He (MSU & Desy), C.-P. Yuan (MSU)
|
Quartic Gauge Boson Couplings at Linear Colliders ---Interplay of
WWZ/ZZZ Production and WW-Fusion--
|
Latex, 15pp, 3eps-Figs, Refs added, To appear in Phys. Lett. B (1998)
|
Phys.Lett. B422 (1998) 294-304
|
10.1016/S0370-2693(98)00052-5
|
MADPH-97-1025, UCD-97-22, MSUHEP-70930
|
hep-ph
| null |
We study new physics effects to the quartic gauge boson couplings formulated
by the electroweak chiral Lagrangian. Five next-to-leading order operators
characterize the anomalous quartic gauge interactions which involve pure
Goldstone boson dynamics for the electroweak symmetry breaking. We estimate the
typical size of these couplings in different strongly-interacting models and
examine the sensitivity to directly probing them via the WWZ/ZZZ triple gauge
boson production at the high energy linear colliders. The important roles of
polarized e- and e+ beams are stressed. We then compare the results with those
from the W-pair production of the WW-fusion processes, and analyze the
interplay of these two production mechanisms for an improved probe of the
quartic gauge boson interactions.
|
[
{
"created": "Mon, 24 Nov 1997 07:02:27 GMT",
"version": "v1"
},
{
"created": "Tue, 25 Nov 1997 01:23:57 GMT",
"version": "v2"
},
{
"created": "Tue, 13 Jan 1998 23:11:23 GMT",
"version": "v3"
}
] |
2009-10-30
|
[
[
"Han",
"T.",
"",
"Wisconsin & Davis"
],
[
"He",
"H. -J.",
"",
"MSU & Desy"
],
[
"Yuan",
"C. -P.",
"",
"MSU"
]
] |
We study new physics effects to the quartic gauge boson couplings formulated by the electroweak chiral Lagrangian. Five next-to-leading order operators characterize the anomalous quartic gauge interactions which involve pure Goldstone boson dynamics for the electroweak symmetry breaking. We estimate the typical size of these couplings in different strongly-interacting models and examine the sensitivity to directly probing them via the WWZ/ZZZ triple gauge boson production at the high energy linear colliders. The important roles of polarized e- and e+ beams are stressed. We then compare the results with those from the W-pair production of the WW-fusion processes, and analyze the interplay of these two production mechanisms for an improved probe of the quartic gauge boson interactions.
|
2301.10786
|
Ritu Dcruz
|
Ritu Dcruz
|
Flavor Physics Constraints on Left-Right Symmetric Models with Universal
Seesaw
|
41 pages, 11 figures, 23 tables
| null |
10.1016/j.nuclphysb.2024.116519
| null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
We study the phenomenological constraints on the parameter space in the
parity symmetric scenario of a class of left-right symmetric models in which
the fermion masses are generated through a universal seesaw mechanism. The
model, motivated by the axionless solution to the strong $\mathcal{CP}$
problem, has a simple Higgs sector consisting of left- and right-handed
doublets. The fermion masses are then generated through their mixing with heavy
vector-like fermions, which leads to flavor changing neutral currents arising
at tree-level and also introduces non-unitarity in the charged current
interactions. These new contributions lead to flavor and flavor universality
violating processes and forbidden decays, which are used to derive constraints
on the parameter space of the model. We also argue that although the model has
the potential to resolve flavor anomalies, it fails to do so in the case of
B-anomalies $R_{K^{(*)}}$ and anomalous magnetic moment of muon $(g-2)_\mu$.
|
[
{
"created": "Wed, 25 Jan 2023 19:00:09 GMT",
"version": "v1"
},
{
"created": "Sun, 7 Jul 2024 02:04:19 GMT",
"version": "v2"
}
] |
2024-07-09
|
[
[
"Dcruz",
"Ritu",
""
]
] |
We study the phenomenological constraints on the parameter space in the parity symmetric scenario of a class of left-right symmetric models in which the fermion masses are generated through a universal seesaw mechanism. The model, motivated by the axionless solution to the strong $\mathcal{CP}$ problem, has a simple Higgs sector consisting of left- and right-handed doublets. The fermion masses are then generated through their mixing with heavy vector-like fermions, which leads to flavor changing neutral currents arising at tree-level and also introduces non-unitarity in the charged current interactions. These new contributions lead to flavor and flavor universality violating processes and forbidden decays, which are used to derive constraints on the parameter space of the model. We also argue that although the model has the potential to resolve flavor anomalies, it fails to do so in the case of B-anomalies $R_{K^{(*)}}$ and anomalous magnetic moment of muon $(g-2)_\mu$.
|
hep-ph/9204208
|
Aneesh V. Manohar
|
Aneesh V. Manohar
|
An Introduction to Spin Dependent Deep Inelastic Scattering
|
48 Pages, 8 Figures; 7th Lake Louise Winter Institute, eds. Campbell
et al. (Lectures presented at the Lake Louise Winter Institute, February,
1992)
| null | null | null |
hep-ph
| null |
The main focus of these lectures is on those aspects of deep inelastic
scattering that can be derived directly from QCD using quantum field theory,
without recourse to phenomenological models. The emphasis is on spin dependent
scattering, but the theory of spin averaged scattering is also discussed. A
detailed analysis is given for the case of spin 1/2 targets, with a brief
discussion of higher spin targets at the end. The QCD derivation of the
Callan-Gross relation, the longitudinal structure function $F_L$, and the
Bjorken and Ellis-Jaffe sum rules is presented. I also discuss the
Wilczek-Wandzura contribution to $g_2$, and why the Gottfried sum rule does not
hold in QCD.
|
[
{
"created": "Sun, 5 Apr 1992 21:15:09 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Manohar",
"Aneesh V.",
""
]
] |
The main focus of these lectures is on those aspects of deep inelastic scattering that can be derived directly from QCD using quantum field theory, without recourse to phenomenological models. The emphasis is on spin dependent scattering, but the theory of spin averaged scattering is also discussed. A detailed analysis is given for the case of spin 1/2 targets, with a brief discussion of higher spin targets at the end. The QCD derivation of the Callan-Gross relation, the longitudinal structure function $F_L$, and the Bjorken and Ellis-Jaffe sum rules is presented. I also discuss the Wilczek-Wandzura contribution to $g_2$, and why the Gottfried sum rule does not hold in QCD.
|
1712.03805
|
Lata Thakur
|
Guruprasad Kadam, Hiranmaya Mishra, Lata Thakur
|
Electrical and thermal conductivities of hot and dense hadron gas
|
18 pages, 5 figures, Added discussions, typos corrected, version to
appear in Phys. Rev. D
|
Phys. Rev. D 98, 114001 (2018)
|
10.1103/PhysRevD.98.114001
| null |
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We estimate the electrical and thermal conductivities of hot and dense
hadronic matter in the relaxation time approximation of the Boltzmann equation.
We estimate the thermodynamical quantities of hot and dense hadronic matter
within the ambit of the excluded volume hadron resonance gas model. The
relaxation time for all the hadrons is estimated assuming the constant cross
section with uniform as well as mass dependent hard-core radius. We compare our
results with various existing results. Finally we give an estimate of
electrical and thermal conductivities in the context of heavy ion collision
experiments.
|
[
{
"created": "Mon, 11 Dec 2017 15:02:02 GMT",
"version": "v1"
},
{
"created": "Wed, 21 Nov 2018 15:37:53 GMT",
"version": "v2"
}
] |
2018-12-12
|
[
[
"Kadam",
"Guruprasad",
""
],
[
"Mishra",
"Hiranmaya",
""
],
[
"Thakur",
"Lata",
""
]
] |
We estimate the electrical and thermal conductivities of hot and dense hadronic matter in the relaxation time approximation of the Boltzmann equation. We estimate the thermodynamical quantities of hot and dense hadronic matter within the ambit of the excluded volume hadron resonance gas model. The relaxation time for all the hadrons is estimated assuming the constant cross section with uniform as well as mass dependent hard-core radius. We compare our results with various existing results. Finally we give an estimate of electrical and thermal conductivities in the context of heavy ion collision experiments.
|
hep-ph/9406358
| null |
J. Bernab\'eu, S.M. Bilenky, F.J. Botella, J.A. Pe\~narrocha and J.
Segura
|
Neutrino Mass and Magnetic Moment from Neutrino-Electron Scattering
|
13 pages (+6 figures, available upon request),Standard Latex,
FTUV/94-29,Submitted to ICHEP94
| null | null | null |
hep-ph
| null |
We study both the elastic ($\nu e \rightarrow \nu e$) and the radiative
process ($\nu e \rightarrow \nu e \gamma$) and discuss how these processes can
shed light on some current topics in neutrino physics such as a neutrino
magnetic moment and neutrino oscillations. The radiative process allows to
reach low values of $Q^2$ without the need to operate at very small energies of
recoil electrons, a favourable scenario to search for a neutrino magnetic
moment. The elastic cross section contains a dynamical zero at $E_{\nu}=m/(4
sin^2\theta_{W})$ and forward electrons for the electron antineutrino channel,
which is reachable at reactor facilities and accessible after the convolution
with the antineutrino spectrum. The implication for lepton flavour changing
transitions in that energy region searched for in neutrino oscillation
experiments, which combine disappearance and appearance rates, is discussed.
|
[
{
"created": "Wed, 22 Jun 1994 09:57:13 GMT",
"version": "v1"
}
] |
2016-08-14
|
[
[
"Bernabéu",
"J.",
""
],
[
"Bilenky",
"S. M.",
""
],
[
"Botella",
"F. J.",
""
],
[
"Peñarrocha",
"J. A.",
""
],
[
"Segura",
"J.",
""
]
] |
We study both the elastic ($\nu e \rightarrow \nu e$) and the radiative process ($\nu e \rightarrow \nu e \gamma$) and discuss how these processes can shed light on some current topics in neutrino physics such as a neutrino magnetic moment and neutrino oscillations. The radiative process allows to reach low values of $Q^2$ without the need to operate at very small energies of recoil electrons, a favourable scenario to search for a neutrino magnetic moment. The elastic cross section contains a dynamical zero at $E_{\nu}=m/(4 sin^2\theta_{W})$ and forward electrons for the electron antineutrino channel, which is reachable at reactor facilities and accessible after the convolution with the antineutrino spectrum. The implication for lepton flavour changing transitions in that energy region searched for in neutrino oscillation experiments, which combine disappearance and appearance rates, is discussed.
|
0808.2058
|
St\'ephane Lavignac
|
Asmaa Abada, Pierre Hosteins, Francois-Xavier Josse-Michaux, Stephane
Lavignac
|
Successful Leptogenesis in SO(10) Unification with a Left-Right
Symmetric Seesaw Mechanism
|
32 pages, 23 figures. v2: 2 comments [below Eq. (53) and at the end
of the conclusions] and 1 reference added, typos corrected. Version to be
published in Nucl. Phys. B
|
Nucl.Phys.B809:183-217,2009
|
10.1016/j.nuclphysb.2008.09.043
|
SACLAY-T08/069, LPT-Orsay/08-01
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study thermal leptogenesis in a broad class of supersymmetric SO(10)
models with a left-right symmetric seesaw mechanism, taking into account
flavour effects and the contribution of the next-to-lightest right-handed
neutrino supermultiplet. Assuming M_D = M_u and a normal hierarchy of light
neutrino masses, we show that four out of the eight right-handed neutrino mass
spectra reconstructed from low-energy neutrino data can lead to successful
leptogenesis with a reheating temperature in the (10^9 - 10^10) GeV range. In
the remaining four solutions, leptogenesis is dominated by N_2 decays, as in
the type I seesaw case. We find that some of these spectra can generate the
observed baryon asymmetry for reheating temperatures above 10^10 GeV, in
contrast to the type I case. Together with flavour effects, an accurate
description of charged fermion masses turns out to be a crucial ingredient in
the analysis.
|
[
{
"created": "Thu, 14 Aug 2008 20:24:03 GMT",
"version": "v1"
},
{
"created": "Mon, 13 Oct 2008 10:45:59 GMT",
"version": "v2"
}
] |
2008-12-18
|
[
[
"Abada",
"Asmaa",
""
],
[
"Hosteins",
"Pierre",
""
],
[
"Josse-Michaux",
"Francois-Xavier",
""
],
[
"Lavignac",
"Stephane",
""
]
] |
We study thermal leptogenesis in a broad class of supersymmetric SO(10) models with a left-right symmetric seesaw mechanism, taking into account flavour effects and the contribution of the next-to-lightest right-handed neutrino supermultiplet. Assuming M_D = M_u and a normal hierarchy of light neutrino masses, we show that four out of the eight right-handed neutrino mass spectra reconstructed from low-energy neutrino data can lead to successful leptogenesis with a reheating temperature in the (10^9 - 10^10) GeV range. In the remaining four solutions, leptogenesis is dominated by N_2 decays, as in the type I seesaw case. We find that some of these spectra can generate the observed baryon asymmetry for reheating temperatures above 10^10 GeV, in contrast to the type I case. Together with flavour effects, an accurate description of charged fermion masses turns out to be a crucial ingredient in the analysis.
|
1311.2198
|
B. Lee Roberts
|
Thomas Blum, Achim Denig, Ivan Logashenko, Eduardo de Rafael, B. Lee
Roberts, Thomas Teubner, Graziano Venanzoni
|
The Muon (g-2) Theory Value: Present and Future
|
Whitepaper prepared for the US Particle Physics "Snowmass" Self Study
| null | null | null |
hep-ph hep-ex hep-lat
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
This White Paper briefly reviews the present status of the muon (g-2)
Standard-Model prediction. This value results in a 3 - 4 standard-deviation
difference with the experimental result from Brookhaven E821. The present
experimental uncertainty is $\pm 63 \times 10^{-11}$ (0.54~ppm), and the
Standard-Model uncertainty is $\simeq \pm 49 \times 10^{-11}$. Fermilab
experiment E989 has the goal to reduce the experimental error to $\pm 16 \times
10^{-11}$. Improvements in the Standard-Model value, which should be achieved
between now and when the first results from Fermilab E989 could be available,
should lead to a Standard-Model uncertainty of $\sim \,\pm 35 \times 10^{-11}$.
These improvements would halve the uncertainty on the difference between
experiment and theory, and should clarify whether the current difference points
toward New Physics, or to a statistical fluctuation. At present, the (g-2)
result is arguably the most compelling indicator of physics beyond the Standard
Model and, at the very least, it represents a major constraint for speculative
new theories such as supersymmetry, dark gauge bosons or extra dimensions.
|
[
{
"created": "Sat, 9 Nov 2013 18:46:41 GMT",
"version": "v1"
}
] |
2013-11-12
|
[
[
"Blum",
"Thomas",
""
],
[
"Denig",
"Achim",
""
],
[
"Logashenko",
"Ivan",
""
],
[
"de Rafael",
"Eduardo",
""
],
[
"Roberts",
"B. Lee",
""
],
[
"Teubner",
"Thomas",
""
],
[
"Venanzoni",
"Graziano",
""
]
] |
This White Paper briefly reviews the present status of the muon (g-2) Standard-Model prediction. This value results in a 3 - 4 standard-deviation difference with the experimental result from Brookhaven E821. The present experimental uncertainty is $\pm 63 \times 10^{-11}$ (0.54~ppm), and the Standard-Model uncertainty is $\simeq \pm 49 \times 10^{-11}$. Fermilab experiment E989 has the goal to reduce the experimental error to $\pm 16 \times 10^{-11}$. Improvements in the Standard-Model value, which should be achieved between now and when the first results from Fermilab E989 could be available, should lead to a Standard-Model uncertainty of $\sim \,\pm 35 \times 10^{-11}$. These improvements would halve the uncertainty on the difference between experiment and theory, and should clarify whether the current difference points toward New Physics, or to a statistical fluctuation. At present, the (g-2) result is arguably the most compelling indicator of physics beyond the Standard Model and, at the very least, it represents a major constraint for speculative new theories such as supersymmetry, dark gauge bosons or extra dimensions.
|
hep-ph/9811510
| null |
Jihn E. Kim, Bumseok Kyae, and Jae Sik Lee
|
R_F Parity and Almost Massless Up Quark
|
7 pages by revtex
|
Phys.Lett. B447 (1999) 110-115
|
10.1016/S0370-2693(98)01587-1
|
KIAS-P98041 and SNUTP-98130
|
hep-ph
| null |
We introduce a parity $R_F$ to introduce naturally small masses for the first
family members and in particular almost massless $u$ quark toward the strong CP
solution. We also discuss the phenomenological implications of this model on
the proton decay and the neutrino mass. Furthermore, it is possible to embed
this $R_F$ parity to local $U(1)_R$ gauge symmetry.
|
[
{
"created": "Mon, 30 Nov 1998 22:54:53 GMT",
"version": "v1"
}
] |
2009-10-31
|
[
[
"Kim",
"Jihn E.",
""
],
[
"Kyae",
"Bumseok",
""
],
[
"Lee",
"Jae Sik",
""
]
] |
We introduce a parity $R_F$ to introduce naturally small masses for the first family members and in particular almost massless $u$ quark toward the strong CP solution. We also discuss the phenomenological implications of this model on the proton decay and the neutrino mass. Furthermore, it is possible to embed this $R_F$ parity to local $U(1)_R$ gauge symmetry.
|
hep-ph/0512035
|
Jozsef Zimanyi
|
J. Zimanyi
|
Evolution of the concept of Quark Matter: the Ianus face of the heavy
ion collisions
|
Talk given at 18th International Conference on Ultrarelativistic
Nucleus-Nucleus Collisions: Quark Matter 2005 (QM 2005), Budapest, Hungary,
4-9 Aug 2005. 10 pages, 7 figures
|
Nucl.Phys. A774 (2006) 25-34
|
10.1016/j.nuclphysa.2006.06.010
| null |
hep-ph
| null |
Since the beginning of the efforts to produce and understand quark matter
large changes developed in the ideas of description of this matter. In the
present paper we summarize some aspects of this development.
|
[
{
"created": "Fri, 2 Dec 2005 13:48:45 GMT",
"version": "v1"
}
] |
2009-11-11
|
[
[
"Zimanyi",
"J.",
""
]
] |
Since the beginning of the efforts to produce and understand quark matter large changes developed in the ideas of description of this matter. In the present paper we summarize some aspects of this development.
|
hep-ph/0507184
|
Jean-Philippe Lansberg
|
J.P. Lansberg
|
Ambiguities in the calculation of leptonic decays of excited heavy
quarkonium
|
Presented at HADRONIC PHYSICS (HLPR 2004): Joint
Meeting-Heidelberg-Liege-Paris-Rostock, Spa, Belgium, 16-18 December 2004, 11
pages, 11 figures, LaTeX, uses aip-6s.clo, aipproc.cls and aipxfm.sty
(included); Figure 9 corrected
|
AIP Conf.Proc. 775 (2005) 11
|
10.1063/1.1961038
| null |
hep-ph
| null |
We point out that the determination of the leptonic decay width of
radially-excited quarkonia is strongly dependent on the position of the node
typical of these excitations. We suggest that this feature could be related
with the longstanding rho-pi puzzle.
|
[
{
"created": "Fri, 15 Jul 2005 09:39:36 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Lansberg",
"J. P.",
""
]
] |
We point out that the determination of the leptonic decay width of radially-excited quarkonia is strongly dependent on the position of the node typical of these excitations. We suggest that this feature could be related with the longstanding rho-pi puzzle.
|
2008.08606
|
Tom Steudtner
|
Gudrun Hiller, Clara Hormigos-Feliu, Daniel F. Litim, Tom Steudtner
|
Model Building from Asymptotic Safety with Higgs and Flavor Portals
|
40 pages, 23 figures, 11 tables
| null |
10.1103/PhysRevD.102.095023
|
DO-TH 20/08
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We perform a comprehensive search for Standard Model extensions inspired by
asymptotic safety. Our models feature a singlet matrix scalar field, three
generations of vector-like leptons, and direct links to the Higgs and flavor
sectors via new Yukawa and portal couplings. A novel feature is that the
enlarged scalar sector may spontaneously break lepton flavor universality. We
provide a complete two-loop renormalization group analysis of the running
gauge, Yukawa, and quartic couplings to find ultraviolet fixed points and the
BSM critical surface of parameters, $i.e.$ the set of boundary conditions at
the TeV scale for which models remain well-behaved and predictive up to the
Planck scale without encountering Landau poles or instabilities. This includes
templates for asymptotically safe Standard Model extensions which match the
measured values of gauge couplings and the Higgs, top, and bottom masses. We
further detail the phenomenology of our models covering production, decay,
fermion mixing, anomalous magnetic moments, effects from scalar mixing and
chiral enhancement, and constraints on model parameters from data. Signatures
at proton-proton and lepton colliders such as lepton flavor violation and
displaced vertices, and the prospect for electric dipole moments or charged
lepton-flavor-violating type processes, are also indicated.
|
[
{
"created": "Wed, 19 Aug 2020 18:00:13 GMT",
"version": "v1"
}
] |
2020-12-30
|
[
[
"Hiller",
"Gudrun",
""
],
[
"Hormigos-Feliu",
"Clara",
""
],
[
"Litim",
"Daniel F.",
""
],
[
"Steudtner",
"Tom",
""
]
] |
We perform a comprehensive search for Standard Model extensions inspired by asymptotic safety. Our models feature a singlet matrix scalar field, three generations of vector-like leptons, and direct links to the Higgs and flavor sectors via new Yukawa and portal couplings. A novel feature is that the enlarged scalar sector may spontaneously break lepton flavor universality. We provide a complete two-loop renormalization group analysis of the running gauge, Yukawa, and quartic couplings to find ultraviolet fixed points and the BSM critical surface of parameters, $i.e.$ the set of boundary conditions at the TeV scale for which models remain well-behaved and predictive up to the Planck scale without encountering Landau poles or instabilities. This includes templates for asymptotically safe Standard Model extensions which match the measured values of gauge couplings and the Higgs, top, and bottom masses. We further detail the phenomenology of our models covering production, decay, fermion mixing, anomalous magnetic moments, effects from scalar mixing and chiral enhancement, and constraints on model parameters from data. Signatures at proton-proton and lepton colliders such as lepton flavor violation and displaced vertices, and the prospect for electric dipole moments or charged lepton-flavor-violating type processes, are also indicated.
|
hep-ph/9812301
|
Jonathan R. Ellis
|
C.H. Llewellyn Smith (CERN)
|
Inelastic Sum Rules
|
Talk given at the Sid Drell Symposium, SLAC, Stanford, California,
July 31st, 1998, 17 pages LaTeX, 2 figures, uses cernart.cls (included)
| null | null |
CERN-DG/98-3534
|
hep-ph
| null |
The history and present status of several sum rules for deep-inelastic lepton
scattering are reviewed, with particular attention to the discovery of scaling,
partons, quarks and QCD. Two outstanding issues are then discussed in more
detail: the singlet (Ellis-Jaffe) nucleon spin sum rule and the
Drell-Hearn-Gerasimov-Iddings sum rule.
|
[
{
"created": "Wed, 9 Dec 1998 17:44:29 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Smith",
"C. H. Llewellyn",
"",
"CERN"
]
] |
The history and present status of several sum rules for deep-inelastic lepton scattering are reviewed, with particular attention to the discovery of scaling, partons, quarks and QCD. Two outstanding issues are then discussed in more detail: the singlet (Ellis-Jaffe) nucleon spin sum rule and the Drell-Hearn-Gerasimov-Iddings sum rule.
|
hep-ph/0012017
|
Ed Stoeffhaas
|
V. Barger, S. Geer, R. Raja, and K. Whisnant
|
Exploring Neutrino Oscillations with Superbeams
|
Revtex (singlespaced), 41 pages, uses epsf.sty, 12 postscript
figures. Minor corrections and notation changes, expanded discussions, x-axis
numbers added to Fig.9(a),(c). To be published in Phys. Rev. D
|
Phys.Rev.D63:113011,2001
|
10.1103/PhysRevD.63.113011
|
MADPH-00-1199, FERMILAB-Pub-00/318-T, AMES-HET-00-12
|
hep-ph
| null |
We consider the medium- and long-baseline oscillation physics capabilities of
intense muon-neutrino and muon-antineutrino beams produced using future
upgraded megawatt-scale high-energy proton beams. In particular we consider the
potential of these conventional neutrino ``superbeams'' for observing
\nu_\mu\to\nu_e oscillations, determining the hierarchy of neutrino mass
eigenstates, and measuring CP-violation in the lepton sector. The physics
capabilities of superbeams are explored as a function of the beam energy,
baseline, and the detector parameters. The trade-offs between very large
detectors with poor background rejection and smaller detectors with excellent
background rejection are illustrated. We find that it may be possible to
observe \nu_\mu\to\nu_e oscillations with a superbeam provided that the
amplitude parameter \sin^2 2\theta_{13} is larger than a few \times 10^{-3}. If
\sin^2 2\theta_{13} is of order 10^{-2} or larger, then the neutrino mass
hierarchy can be determined in long-baseline experiments, and if in addition
the large mixing angle MSW solution describes the solar neutrino deficit then
there is a small region of parameter space within which maximal CP-violation in
the lepton sector would be observable in a low-energy medium-baseline
experiment. We explicitly consider massive water Cherenkov and liquid argon
detectors at superbeams with neutrino energies ranging from 1 GeV to 15 GeV,
and baselines from 295 km to 9300 km. Finally, we compare the oscillation
physics prospects at superbeams with the corresponding prospects at neutrino
factories. The sensitivity at a neutrino factory to CP violation and the
neutrino mass hierarchy extends to values of the amplitude parameter \sin^2
2\theta_{13} that are one to two orders of magnitude lower than at a superbeam.
|
[
{
"created": "Fri, 1 Dec 2000 22:31:12 GMT",
"version": "v1"
},
{
"created": "Fri, 27 Apr 2001 17:09:27 GMT",
"version": "v2"
}
] |
2009-09-15
|
[
[
"Barger",
"V.",
""
],
[
"Geer",
"S.",
""
],
[
"Raja",
"R.",
""
],
[
"Whisnant",
"K.",
""
]
] |
We consider the medium- and long-baseline oscillation physics capabilities of intense muon-neutrino and muon-antineutrino beams produced using future upgraded megawatt-scale high-energy proton beams. In particular we consider the potential of these conventional neutrino ``superbeams'' for observing \nu_\mu\to\nu_e oscillations, determining the hierarchy of neutrino mass eigenstates, and measuring CP-violation in the lepton sector. The physics capabilities of superbeams are explored as a function of the beam energy, baseline, and the detector parameters. The trade-offs between very large detectors with poor background rejection and smaller detectors with excellent background rejection are illustrated. We find that it may be possible to observe \nu_\mu\to\nu_e oscillations with a superbeam provided that the amplitude parameter \sin^2 2\theta_{13} is larger than a few \times 10^{-3}. If \sin^2 2\theta_{13} is of order 10^{-2} or larger, then the neutrino mass hierarchy can be determined in long-baseline experiments, and if in addition the large mixing angle MSW solution describes the solar neutrino deficit then there is a small region of parameter space within which maximal CP-violation in the lepton sector would be observable in a low-energy medium-baseline experiment. We explicitly consider massive water Cherenkov and liquid argon detectors at superbeams with neutrino energies ranging from 1 GeV to 15 GeV, and baselines from 295 km to 9300 km. Finally, we compare the oscillation physics prospects at superbeams with the corresponding prospects at neutrino factories. The sensitivity at a neutrino factory to CP violation and the neutrino mass hierarchy extends to values of the amplitude parameter \sin^2 2\theta_{13} that are one to two orders of magnitude lower than at a superbeam.
|
1803.01297
|
Zheng-Tao Wei
|
Jie Zhu, Zheng-Tao Wei, and Hong-Wei Ke
|
The semi-leptonic and non-leptonic weak decays of $\Lambda_b^0$
|
66 pages, 6 figures
|
Phys. Rev. D 99, 054020 (2019)
|
10.1103/PhysRevD.99.054020
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The recent experimental developments require a more precise theoretical study
of weak decays of heavy baryon $\Lambda_b^0$. In this work, we provide an
updated and systematic analysis of both the semi-leptonic and nonleptonic
decays of $\Lambda^0_b$ into baryons $\Lambda^+_c$, $\Lambda$, $p$, and $n$.
The diquark approximation is adopted so that the methods developed in the $B$
meson system can be extended into the baryon system. The baryon-to-baryon
transition form factors are calculated in the framework of a covariant
light-front quark model. The form factors $f_3, ~g_3$ can be extracted and are
found to be non-negligible. The semi-leptonic processes of $\Lambda^0_b\to
\Lambda^+_c(p)l^-\bar\nu_l$ are calculated and the results are consistent with
the experiment. We study the non-leptonic processes within the QCD
factorization approach. The decay amplitudes are calculated at the
next-to-leading order in strong coupling constant $\alpha_s$. We calculate the
non-leptonic decays of $\Lambda^0_b$ into a baryon and a s-wave meson
(pseudoscalar or vector) including 44 processes in total. The branching ratios
and direct CP asymmetries are predicted. The numerical results are compared to
the experimental data and those in the other theoretical approaches. Our
results show validity of the diquark approximation and application of QCD
factorization approach into the heavy baryon system.
|
[
{
"created": "Sun, 4 Mar 2018 04:14:47 GMT",
"version": "v1"
}
] |
2019-04-03
|
[
[
"Zhu",
"Jie",
""
],
[
"Wei",
"Zheng-Tao",
""
],
[
"Ke",
"Hong-Wei",
""
]
] |
The recent experimental developments require a more precise theoretical study of weak decays of heavy baryon $\Lambda_b^0$. In this work, we provide an updated and systematic analysis of both the semi-leptonic and nonleptonic decays of $\Lambda^0_b$ into baryons $\Lambda^+_c$, $\Lambda$, $p$, and $n$. The diquark approximation is adopted so that the methods developed in the $B$ meson system can be extended into the baryon system. The baryon-to-baryon transition form factors are calculated in the framework of a covariant light-front quark model. The form factors $f_3, ~g_3$ can be extracted and are found to be non-negligible. The semi-leptonic processes of $\Lambda^0_b\to \Lambda^+_c(p)l^-\bar\nu_l$ are calculated and the results are consistent with the experiment. We study the non-leptonic processes within the QCD factorization approach. The decay amplitudes are calculated at the next-to-leading order in strong coupling constant $\alpha_s$. We calculate the non-leptonic decays of $\Lambda^0_b$ into a baryon and a s-wave meson (pseudoscalar or vector) including 44 processes in total. The branching ratios and direct CP asymmetries are predicted. The numerical results are compared to the experimental data and those in the other theoretical approaches. Our results show validity of the diquark approximation and application of QCD factorization approach into the heavy baryon system.
|
2407.05923
|
Wei Kou
|
Chengdong Han, Xiaopeng Wang, Wei Kou, Xurong Chen
|
Maximum Entropy Method for Valence Quark Distributions in Exotic
Hadrons: A Study of the $Z_c(3900)$ Case
|
7 pages, 7 figures
| null | null | null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
In this study we demonstrate the application of the Maximum Entropy Method
(MEM) to determine the valence quark distribution of exotic hadrons. Our
investigation yields three key findings. Firstly, we observe a significant
shift towards smaller Bjorken scale $x$ in the peak position of the valence
quark distribution for hadrons with an increasing number of valence quarks,
consistent with previous results by Kawamura and Kumano. Secondly, assuming
that the $Z_c(3900)$ initially consists of four valence quarks, we employ MEM
to determine its initial valence quark distribution, estimating a radius of
$r_c=1.276$ fm at an extremely low resolution scale $Q^2$. Furthermore, we
identify a notable discrepancy between our computed charge form factor $G_c(q)$
at leading order and the outcomes of hadron molecular state calculations. We
propose that this form factor can be extracted from the QCD counting rule
cross-section, which is grounded in Generalized Distribution Amplitudes (GDA)
linked to the multi-quark states.
|
[
{
"created": "Mon, 8 Jul 2024 13:31:18 GMT",
"version": "v1"
}
] |
2024-07-09
|
[
[
"Han",
"Chengdong",
""
],
[
"Wang",
"Xiaopeng",
""
],
[
"Kou",
"Wei",
""
],
[
"Chen",
"Xurong",
""
]
] |
In this study we demonstrate the application of the Maximum Entropy Method (MEM) to determine the valence quark distribution of exotic hadrons. Our investigation yields three key findings. Firstly, we observe a significant shift towards smaller Bjorken scale $x$ in the peak position of the valence quark distribution for hadrons with an increasing number of valence quarks, consistent with previous results by Kawamura and Kumano. Secondly, assuming that the $Z_c(3900)$ initially consists of four valence quarks, we employ MEM to determine its initial valence quark distribution, estimating a radius of $r_c=1.276$ fm at an extremely low resolution scale $Q^2$. Furthermore, we identify a notable discrepancy between our computed charge form factor $G_c(q)$ at leading order and the outcomes of hadron molecular state calculations. We propose that this form factor can be extracted from the QCD counting rule cross-section, which is grounded in Generalized Distribution Amplitudes (GDA) linked to the multi-quark states.
|
hep-ph/9604302
|
Alon Faraggi
|
Alon E. Faraggi and Manuel Masip
|
Leptophobic Z' from Superstring Derived Models
|
15 pages. Standard Latex. Four tables. reference added. Table
modified to fit page
|
Phys.Lett.B388:524-531,1996
|
10.1016/S0370-2693(96)01187-2
|
UFIFT-HEP-96-11
|
hep-ph hep-th
| null |
It was recently suggested that the reported anomalies in $R_b$ and $R_c$ can
be interpreted as the effect of a heavy vector boson that couples to quarks and
is universally decoupled from leptons. We examine how an extra gauge boson with
this property can arise from superstring derived models. In a specific three
generation model we show that the $U(1)_{B-L}$ symmetry combines with the
horizontal flavor symmetries to form a universal leptophobic $U(1)$ symmetry.
In our model there is an enhancement of the color gauge group from twisted
sectors. The enhancement occurs after the breaking of the unifying gauge
symmetry by ``Wilson lines''. The leptophobic $U(1)$ symmetry then becomes a
generator of the color $SU(4)$ gauge group. We examine how similar symmetries
may appear in other string models without the enhancement. We propose that if
the current LEP anomalies persist it may be evidence for a certain class of
un--unified superstring models.
|
[
{
"created": "Fri, 12 Apr 1996 05:49:16 GMT",
"version": "v1"
},
{
"created": "Mon, 15 Apr 1996 16:29:48 GMT",
"version": "v2"
}
] |
2011-01-25
|
[
[
"Faraggi",
"Alon E.",
""
],
[
"Masip",
"Manuel",
""
]
] |
It was recently suggested that the reported anomalies in $R_b$ and $R_c$ can be interpreted as the effect of a heavy vector boson that couples to quarks and is universally decoupled from leptons. We examine how an extra gauge boson with this property can arise from superstring derived models. In a specific three generation model we show that the $U(1)_{B-L}$ symmetry combines with the horizontal flavor symmetries to form a universal leptophobic $U(1)$ symmetry. In our model there is an enhancement of the color gauge group from twisted sectors. The enhancement occurs after the breaking of the unifying gauge symmetry by ``Wilson lines''. The leptophobic $U(1)$ symmetry then becomes a generator of the color $SU(4)$ gauge group. We examine how similar symmetries may appear in other string models without the enhancement. We propose that if the current LEP anomalies persist it may be evidence for a certain class of un--unified superstring models.
|
hep-ph/9610367
|
A. Khodjamirian
|
A. Khodjamirian and R. R\"uckl
|
Sum-Rule Results on Exclusive Decays of Heavy Mesons
|
6 pages, LaTex, 2 figures, epsf; talk presented by A. Khodjamirian at
28th International Conference on High Energy Physics, Warsaw, July 1996
| null | null |
WUE-ITP-96-020, MPI-PhT/96-108
|
hep-ph
| null |
We review QCD sum rule applications to hadronic matrix elements of exclusive
$B$ and $D$ decays. Results are presented for the form factors $f^+$ and $F_0$
of $B \rightarrow \pi$ and $D\rightarrow \pi$ transitions. The predictions are
used to compute the width of $D^* \rightarrow D \pi$, and to extract the CKM
parameter $V_{ub}$ from the measured $B \rightarrow \pi e \nu$ width.
Furthermore, we comment on weak annihilation in $B \rightarrow \rho \gamma$, as
well as on the radiative decays $D \rightarrow \rho \gamma$, $D \rightarrow K^*
\gamma$, and $B \rightarrow \mu \nu \gamma$.
|
[
{
"created": "Tue, 15 Oct 1996 16:12:59 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Khodjamirian",
"A.",
""
],
[
"Rückl",
"R.",
""
]
] |
We review QCD sum rule applications to hadronic matrix elements of exclusive $B$ and $D$ decays. Results are presented for the form factors $f^+$ and $F_0$ of $B \rightarrow \pi$ and $D\rightarrow \pi$ transitions. The predictions are used to compute the width of $D^* \rightarrow D \pi$, and to extract the CKM parameter $V_{ub}$ from the measured $B \rightarrow \pi e \nu$ width. Furthermore, we comment on weak annihilation in $B \rightarrow \rho \gamma$, as well as on the radiative decays $D \rightarrow \rho \gamma$, $D \rightarrow K^* \gamma$, and $B \rightarrow \mu \nu \gamma$.
|
1309.3247
|
Stuart Raby
|
Stuart Raby
|
SO(10) Yukawa Unification after the First Run of the LHC
|
12 pages, talk presented at the VIIth International Conference on
Interconnections between Particle Physics and Cosmology and CETUP* 2013,
Lead, SD
| null |
10.1063/1.4883439
|
OHSTPY-HEP-T-13-004
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In this talk we discuss SO(10) Yukawa unification and its ramifications for
phenomenology. The initial constraints come from fitting the top, bottom and
tau masses, requiring large $\tan\beta \sim 50$ and particular values for soft
SUSY breaking parameters. We perform a global $\chi^2$ analysis, fitting the
recently observed `Higgs' with mass of order 125 GeV in addition to fermion
masses and mixing angles and several flavor violating observables. We discuss
two distinct GUT scale boundary conditions for soft SUSY breaking masses. In
both cases we have a universal cubic scalar parameter, $A_0$. In the first case
we consider universal gaugino masses, and universal scalar masses, $m_{16}$,
for squarks and sleptons; while in the latter case we have non-universal
gaugino masses and either universal scalar masses, $m_{16}$, for squarks and
sleptons or D-term splitting of scalar masses. We discuss the spectrum of SUSY
particle masses and consequences for the LHC.
|
[
{
"created": "Thu, 12 Sep 2013 19:18:12 GMT",
"version": "v1"
},
{
"created": "Fri, 13 Sep 2013 12:16:42 GMT",
"version": "v2"
}
] |
2015-06-17
|
[
[
"Raby",
"Stuart",
""
]
] |
In this talk we discuss SO(10) Yukawa unification and its ramifications for phenomenology. The initial constraints come from fitting the top, bottom and tau masses, requiring large $\tan\beta \sim 50$ and particular values for soft SUSY breaking parameters. We perform a global $\chi^2$ analysis, fitting the recently observed `Higgs' with mass of order 125 GeV in addition to fermion masses and mixing angles and several flavor violating observables. We discuss two distinct GUT scale boundary conditions for soft SUSY breaking masses. In both cases we have a universal cubic scalar parameter, $A_0$. In the first case we consider universal gaugino masses, and universal scalar masses, $m_{16}$, for squarks and sleptons; while in the latter case we have non-universal gaugino masses and either universal scalar masses, $m_{16}$, for squarks and sleptons or D-term splitting of scalar masses. We discuss the spectrum of SUSY particle masses and consequences for the LHC.
|
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