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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1612.02841 | Fulvio Piccinini | Carlo Michel Carloni Calame, Mauro Chiesa, Homero Martinez, Guido
Montagna, Oreste Nicrosini, Fulvio Piccinini, Alessandro Vicini | Precision Measurement of the W-Boson Mass: Theoretical Contributions and
Uncertainties | 51 pages, 10 figures and 16 tables. Minor corrections: new citations
and reference to the svn revisions of the POWHEG code. Numerical results and
conclusions unchanged | Phys. Rev. D 96, 093005 (2017) | 10.1103/PhysRevD.96.093005 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We perform a comprehensive analysis of electroweak, QED and mixed
QCD-electroweak corrections underlying the precise measurement of the W-boson
mass M_W at hadron colliders. By applying a template fitting technique, we
detail the impact on M_W of next-to-leading order electroweak and QCD
corrections, multiple photon emission, lepton pair radiation and factorizable
QCD-electroweak contributions. As a by-product, we provide an up-to-date
estimate of the main theoretical uncertainties of perturbative nature. Our
results can serve as a guideline for the assessment of the theoretical
systematics at the Tevatron and LHC and allow a more robust precision
measurement of the W-boson mass at hadron colliders.
| [
{
"created": "Thu, 8 Dec 2016 21:12:03 GMT",
"version": "v1"
},
{
"created": "Tue, 21 Mar 2017 16:00:14 GMT",
"version": "v2"
}
] | 2017-11-22 | [
[
"Calame",
"Carlo Michel Carloni",
""
],
[
"Chiesa",
"Mauro",
""
],
[
"Martinez",
"Homero",
""
],
[
"Montagna",
"Guido",
""
],
[
"Nicrosini",
"Oreste",
""
],
[
"Piccinini",
"Fulvio",
""
],
[
"Vicini",
"Alessandr... | We perform a comprehensive analysis of electroweak, QED and mixed QCD-electroweak corrections underlying the precise measurement of the W-boson mass M_W at hadron colliders. By applying a template fitting technique, we detail the impact on M_W of next-to-leading order electroweak and QCD corrections, multiple photon emission, lepton pair radiation and factorizable QCD-electroweak contributions. As a by-product, we provide an up-to-date estimate of the main theoretical uncertainties of perturbative nature. Our results can serve as a guideline for the assessment of the theoretical systematics at the Tevatron and LHC and allow a more robust precision measurement of the W-boson mass at hadron colliders. |
1902.03839 | Guo-Yuan Huang | Guo-yuan Huang and Shun Zhou | Impact of an eV-mass sterile neutrino on the neutrinoless double-beta
decays: a Bayesian analysis | 16 pages, 5 figures | null | 10.1016/j.nuclphysb.2019.114691 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | To quantitatively assess the impact of an eV-mass sterile neutrino on the
neutrinoless double-beta ($0\nu \beta \beta$) decays, we calculate the
posterior probability distribution of the relevant effective neutrino mass
$|m^\prime_{ee}|$ in the (3+1)$\nu$ mixing scenario, following the Bayesian
statistical approach. The latest global-fit analysis of neutrino oscillation
data, the cosmological bound on the sum of three active neutrino masses from
{\it Planck}, and the constraints from current $0\nu\beta\beta$ decay
experiments are taken into account in our calculations. Based on the resultant
posterior distributions, we find that the average value of the effective
neutrino mass is shifted from $\overline{|m^{}_{ee}|} = 3.37\times 10^{-3}~{\rm
eV}$ (or $7.71\times 10^{-3}~{\rm eV}$) in the standard 3$\nu$ mixing scenario
to $\overline{|m^{\prime}_{ee}|}=2.54\times 10^{-2}~{\rm eV}$ (or $2.56\times
10^{-2}~{\rm eV}$) in the (3+1)$\nu$ mixing scenario, with the logarithmically
uniform prior on the lightest neutrino mass (or on the sum of three active
neutrino masses). Therefore, a null signal from the future $0\nu\beta\beta$
decay experiment with a sensitivity to $|m^{}_{ee}| \approx
\mathcal{O}(10^{-2}_{})~{\rm eV}$ will be able to set a very stringent
constraint on the sterile neutrino mass and the active-sterile mixing angle.
| [
{
"created": "Mon, 11 Feb 2019 12:14:35 GMT",
"version": "v1"
}
] | 2019-09-04 | [
[
"Huang",
"Guo-yuan",
""
],
[
"Zhou",
"Shun",
""
]
] | To quantitatively assess the impact of an eV-mass sterile neutrino on the neutrinoless double-beta ($0\nu \beta \beta$) decays, we calculate the posterior probability distribution of the relevant effective neutrino mass $|m^\prime_{ee}|$ in the (3+1)$\nu$ mixing scenario, following the Bayesian statistical approach. The latest global-fit analysis of neutrino oscillation data, the cosmological bound on the sum of three active neutrino masses from {\it Planck}, and the constraints from current $0\nu\beta\beta$ decay experiments are taken into account in our calculations. Based on the resultant posterior distributions, we find that the average value of the effective neutrino mass is shifted from $\overline{|m^{}_{ee}|} = 3.37\times 10^{-3}~{\rm eV}$ (or $7.71\times 10^{-3}~{\rm eV}$) in the standard 3$\nu$ mixing scenario to $\overline{|m^{\prime}_{ee}|}=2.54\times 10^{-2}~{\rm eV}$ (or $2.56\times 10^{-2}~{\rm eV}$) in the (3+1)$\nu$ mixing scenario, with the logarithmically uniform prior on the lightest neutrino mass (or on the sum of three active neutrino masses). Therefore, a null signal from the future $0\nu\beta\beta$ decay experiment with a sensitivity to $|m^{}_{ee}| \approx \mathcal{O}(10^{-2}_{})~{\rm eV}$ will be able to set a very stringent constraint on the sterile neutrino mass and the active-sterile mixing angle. |
0901.1145 | Brent D. Nelson | Baris Altunkaynak (1), Phillip Grajek (2), Michael Holmes (1), Gordon
Kane (2), and Brent D. Nelson (1) ((1) Northeastern University, (2)
University of Michigan) | Studying Gaugino Mass Unification at the LHC | null | JHEP 0904:114,2009 | 10.1088/1126-6708/2009/04/114 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We begin a systematic study of how gaugino mass unification can be probed at
the CERN Large Hadron Collider (LHC) in a quasi-model independent manner. As a
first step in that direction we focus our attention on the theoretically
well-motivated mirage pattern of gaugino masses, a one-parameter family of
models of which universal (high scale) gaugino masses are a limiting case. We
improve on previous methods to define an analytic expression for the metric on
signature space and use it to study one-parameter deviations from universality
in the gaugino sector, randomizing over other soft supersymmetry-breaking
parameters. We put forward three ensembles of observables targeted at the
physics of the gaugino sector, allowing for a determination of this
non-universality parameter without reconstructing individual mass eigenvalues
or the soft supersymmetry-breaking gaugino masses themselves. In this
controlled environment we find that approximately 80% of the supersymmetric
parameter space would give rise to a model for which our method will detect
non-universality in the gaugino mass sector at the 10% level with an integrated
luminosity of order 10 inverse femptobarns. We discuss strategies for improving
the method and for adding more realism in dealing with the actual experimental
circumstances of the LHC.
| [
{
"created": "Thu, 8 Jan 2009 22:13:12 GMT",
"version": "v1"
}
] | 2010-04-15 | [
[
"Altunkaynak",
"Baris",
""
],
[
"Grajek",
"Phillip",
""
],
[
"Holmes",
"Michael",
""
],
[
"Kane",
"Gordon",
""
],
[
"Nelson",
"Brent D.",
""
]
] | We begin a systematic study of how gaugino mass unification can be probed at the CERN Large Hadron Collider (LHC) in a quasi-model independent manner. As a first step in that direction we focus our attention on the theoretically well-motivated mirage pattern of gaugino masses, a one-parameter family of models of which universal (high scale) gaugino masses are a limiting case. We improve on previous methods to define an analytic expression for the metric on signature space and use it to study one-parameter deviations from universality in the gaugino sector, randomizing over other soft supersymmetry-breaking parameters. We put forward three ensembles of observables targeted at the physics of the gaugino sector, allowing for a determination of this non-universality parameter without reconstructing individual mass eigenvalues or the soft supersymmetry-breaking gaugino masses themselves. In this controlled environment we find that approximately 80% of the supersymmetric parameter space would give rise to a model for which our method will detect non-universality in the gaugino mass sector at the 10% level with an integrated luminosity of order 10 inverse femptobarns. We discuss strategies for improving the method and for adding more realism in dealing with the actual experimental circumstances of the LHC. |
hep-ph/0011290 | Laura Reina | Sally Dawson (BNL), Laura Reina (FSU) | Associated Top-Higgs production at future colliders | 4 pages, 4 figures. Talk given at DPF 2000: The Meeting of the
Division of Particles and Fields of the American Physical Society, Columbus,
Ohio, 9-12 Aug 2000 | Int.J.Mod.Phys. A16S1A (2001) 375-378 | 10.1142/S0217751X01006978 | FSU-HEP-2000-1122 | hep-ph | null | We discuss the relevance of the associated production of a Higgs boson with a
pair of top-antitop quarks at both the LHC and a future high energy e^+e^-
collider.
| [
{
"created": "Wed, 22 Nov 2000 23:17:38 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Dawson",
"Sally",
"",
"BNL"
],
[
"Reina",
"Laura",
"",
"FSU"
]
] | We discuss the relevance of the associated production of a Higgs boson with a pair of top-antitop quarks at both the LHC and a future high energy e^+e^- collider. |
1604.08333 | Gao-Liang Zhou | Gao-Liang Zhou | Cancellation of Infrared Divergence in Inclusive Production of Lepton
Pair Near the Threshold of Heavy Quarkonia | 10 pages, 13 figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The detailed proof of cancellation of topologically unfactorized infrared
divergences in the inclusive production of lepton pair close to the threshold
of heavy quarkonia is presented. To make the effects of transition between
states containing heavy quark pairs, which is important in such cancellation,
the final detected states are constrained to be lepton pair near the threshold
of the heavy quarkonia instead of heavy quarkonia themselves. Such cancellation
is crucial for the NRQCD factorization of these processes.
| [
{
"created": "Thu, 28 Apr 2016 07:43:30 GMT",
"version": "v1"
}
] | 2016-04-29 | [
[
"Zhou",
"Gao-Liang",
""
]
] | The detailed proof of cancellation of topologically unfactorized infrared divergences in the inclusive production of lepton pair close to the threshold of heavy quarkonia is presented. To make the effects of transition between states containing heavy quark pairs, which is important in such cancellation, the final detected states are constrained to be lepton pair near the threshold of the heavy quarkonia instead of heavy quarkonia themselves. Such cancellation is crucial for the NRQCD factorization of these processes. |
1604.04782 | Francesco Giacosa | Francesco Giacosa | The eLSM at nonzero density | Based on the presentation given at FAIRNESS 2016, Workshop for young
scientists with research interests focused on physics at FAIR, 14-19 February
2016, Garmisch-Partenkirchen, Germany. 5 pages, 1 figure | null | 10.1088/1742-6596/742/1/012010 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The extended Linear Sigma Model (eLSM) is an effective model of QCD which
includes in the mesonic sector (pseudo)scalar and (axial-)vector quarkonia
mesons as well as one dilaton/glueball field and in the baryonic sector the
nucleon doublet and its chiral partner in the mirror assignment. The chiral
partner of the pion turns out to be the resonance $f_{0}(1370),$ which is then
predominantly a quarkonium state. As a consequence, $f_{0}(500)$ is
predominately not a quarkonium state but a four-quark object and is at first
not part of the model. Yet, $f_{0}(500)$ is important in the baryonic sector
and affects nuclear matter saturation, the high-density behavior, and
nucleon-nucleon scattering. In these proceedings, we show how to enlarge the
two-flavour version of the eLSM in order to include the four-quark field
$f_{0}(500)$ in a chiral invariant manner. We then discuss homogeneous and
inhomogeneous chiral restoration in a dense medium.
| [
{
"created": "Sat, 16 Apr 2016 18:15:53 GMT",
"version": "v1"
}
] | 2016-11-03 | [
[
"Giacosa",
"Francesco",
""
]
] | The extended Linear Sigma Model (eLSM) is an effective model of QCD which includes in the mesonic sector (pseudo)scalar and (axial-)vector quarkonia mesons as well as one dilaton/glueball field and in the baryonic sector the nucleon doublet and its chiral partner in the mirror assignment. The chiral partner of the pion turns out to be the resonance $f_{0}(1370),$ which is then predominantly a quarkonium state. As a consequence, $f_{0}(500)$ is predominately not a quarkonium state but a four-quark object and is at first not part of the model. Yet, $f_{0}(500)$ is important in the baryonic sector and affects nuclear matter saturation, the high-density behavior, and nucleon-nucleon scattering. In these proceedings, we show how to enlarge the two-flavour version of the eLSM in order to include the four-quark field $f_{0}(500)$ in a chiral invariant manner. We then discuss homogeneous and inhomogeneous chiral restoration in a dense medium. |
hep-ph/0609012 | Natalia Toro | Jared Kaplan, Philip C. Schuster, and Natalia Toro | Avoiding an Empty Universe in RS I Models and Large-N Gauge Theories | 23 pages, 3 figures | null | null | HUTP-06/A0038 | hep-ph | null | Many proposed solutions to the hierarchy problem rely on dimensional
transmutation in asymptotically free gauge theories, and these theories often
have dual descriptions in terms of a warped extra dimension. Gravitational
calculations show that the confining phase transition in Randall-Sundrum models
is first-order and parametrically slower than the rate expected in large-N
gauge theories. This is dangerous because it leads to an empty universe
problem. We argue that this rate suppression arises from approximate conformal
symmetry. Though this empty universe problem cannot be solved by using the
radion for low-scale inflation, we argue that if the radion potential is
asymptotically free, another instanton for the RS phase transition can proceed
as $e^{-N^2}$. We also discuss the existence of light magnetic monopoles ($\sim
100$ TeV) as a possible signature of such a phase transition.
| [
{
"created": "Fri, 1 Sep 2006 20:16:01 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Kaplan",
"Jared",
""
],
[
"Schuster",
"Philip C.",
""
],
[
"Toro",
"Natalia",
""
]
] | Many proposed solutions to the hierarchy problem rely on dimensional transmutation in asymptotically free gauge theories, and these theories often have dual descriptions in terms of a warped extra dimension. Gravitational calculations show that the confining phase transition in Randall-Sundrum models is first-order and parametrically slower than the rate expected in large-N gauge theories. This is dangerous because it leads to an empty universe problem. We argue that this rate suppression arises from approximate conformal symmetry. Though this empty universe problem cannot be solved by using the radion for low-scale inflation, we argue that if the radion potential is asymptotically free, another instanton for the RS phase transition can proceed as $e^{-N^2}$. We also discuss the existence of light magnetic monopoles ($\sim 100$ TeV) as a possible signature of such a phase transition. |
1602.07820 | Kapil Saraswat | Kapil Saraswat, Prashant Shukla, Vineet Kumar and Venktesh Singh | Coherent Pion Production in Neutrino Nucleus Scattering | null | Phys. Rev. C 93, 035504 (2016) | 10.1103/PhysRevC.93.035504 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this article, we study the coherent pion production in neutrino-nucleus
interaction in the resonance region using the formalism based on partially
conserved axial current (PCAC) theorem which relates the neutrino-nucleus cross
section to the pion-nucleus elastic cross section. The pion nucleus elastic
cross section is calculated using the Glauber model in terms of pion-nucleon
cross sections obtained by parameterizing the experimental data. We calculate
the differential and integrated cross sections for charged current coherent
pion production in neutrino carbon scattering. The results of integrated cross
section calculations are compared with the measured data. Predictions for the
differential and integrated cross sections for coherent pion productions in
neutrino iron scattering using above formalism are also made.
| [
{
"created": "Thu, 25 Feb 2016 06:52:24 GMT",
"version": "v1"
},
{
"created": "Tue, 22 Mar 2016 05:49:09 GMT",
"version": "v2"
}
] | 2016-04-06 | [
[
"Saraswat",
"Kapil",
""
],
[
"Shukla",
"Prashant",
""
],
[
"Kumar",
"Vineet",
""
],
[
"Singh",
"Venktesh",
""
]
] | In this article, we study the coherent pion production in neutrino-nucleus interaction in the resonance region using the formalism based on partially conserved axial current (PCAC) theorem which relates the neutrino-nucleus cross section to the pion-nucleus elastic cross section. The pion nucleus elastic cross section is calculated using the Glauber model in terms of pion-nucleon cross sections obtained by parameterizing the experimental data. We calculate the differential and integrated cross sections for charged current coherent pion production in neutrino carbon scattering. The results of integrated cross section calculations are compared with the measured data. Predictions for the differential and integrated cross sections for coherent pion productions in neutrino iron scattering using above formalism are also made. |
0910.5243 | Andrei Mironov | Andrei Mironov, Sergey Mironov, Alexei Morozov and Andrey Morozov | Resolving Puzzles of Massive Gravity with and without violation of
Lorentz symmetry | 46 pages | Class. Quant.Grav.27:125005, 2010 | 10.1088/0264-9381/27/12/125005 | FIAN/TD-04/09 ITEP/TH-77/08 | hep-ph gr-qc hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We perform a systematic study of various versions of massive gravity with and
without violation of Lorentz symmetry in arbitrary dimension. These theories
are well known to possess very unusual properties, unfamiliar from studies of
gauge and Lorentz invariant models. These peculiarities are caused by mixing of
familiar transverse fields with revived longitudinal and pure gauge
(Stueckelberg) fields and are all seen already in quadratic approximation. They
are all associated with non-trivial dispersion laws, which easily allow
superluminal propagation, ghosts, tachyons and essential irrationalities.
Moreover, coefficients in front of emerging modes are small, what makes the
theories essentially non-perturbative within a large Vainshtein radius.
Attempts to get rid of unwanted degrees of freedom by giving them infinite
masses lead to DVZ discontinuities in parameter (moduli) space, caused by
un-permutability of different limits. Also, the condition m_{gh}=\infty can not
be preserved already in non-trivial gravitational backgrounds and is unstable
under any other perturbations of linearized gravity. At the same time an {\it a
priori} healthy model of massive gravity in quadratic approximation definitely
exists: provided by any mass level of Kaluza-Klein tower. It bypasses the
problems because gravity field is mixed with other fields, and this explains
why such mixing helps in other models. At the same time this can imply that the
really healthy massive gravity can still require infinite number of extra
fields beyond quadratic approximation.
| [
{
"created": "Wed, 28 Oct 2009 17:17:45 GMT",
"version": "v1"
}
] | 2014-11-20 | [
[
"Mironov",
"Andrei",
""
],
[
"Mironov",
"Sergey",
""
],
[
"Morozov",
"Alexei",
""
],
[
"Morozov",
"Andrey",
""
]
] | We perform a systematic study of various versions of massive gravity with and without violation of Lorentz symmetry in arbitrary dimension. These theories are well known to possess very unusual properties, unfamiliar from studies of gauge and Lorentz invariant models. These peculiarities are caused by mixing of familiar transverse fields with revived longitudinal and pure gauge (Stueckelberg) fields and are all seen already in quadratic approximation. They are all associated with non-trivial dispersion laws, which easily allow superluminal propagation, ghosts, tachyons and essential irrationalities. Moreover, coefficients in front of emerging modes are small, what makes the theories essentially non-perturbative within a large Vainshtein radius. Attempts to get rid of unwanted degrees of freedom by giving them infinite masses lead to DVZ discontinuities in parameter (moduli) space, caused by un-permutability of different limits. Also, the condition m_{gh}=\infty can not be preserved already in non-trivial gravitational backgrounds and is unstable under any other perturbations of linearized gravity. At the same time an {\it a priori} healthy model of massive gravity in quadratic approximation definitely exists: provided by any mass level of Kaluza-Klein tower. It bypasses the problems because gravity field is mixed with other fields, and this explains why such mixing helps in other models. At the same time this can imply that the really healthy massive gravity can still require infinite number of extra fields beyond quadratic approximation. |
1605.08577 | A. Cooper-Sarkar | A. M Cooper-Sarkar, I. Abt, B. Foster, M. Wing, V. Myronenko, K.
Wichmann | Study of HERA data at Low Q^2 and Low x | 5 pages, 6 figures, proceedings of XXIV International Workshop on
Deep-Inelastic Scattering and Related Subjects | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the HERAPDF2.0 PDF analysis it was noted that the fit $\chi^2$ worsens
significantly at low $Q^2$ for both NLO and NNLO fits. The turn over of the
reduced cross section at low-$x$ and low $Q^2$ due to the contribution of the
longitudinal cross section $F_L$ is also not very well described. In this paper
the prediction for $F_L$ is highlighted and the corresponding extraction of
$F_2$ from the data is further investigated, showing discrepancies with
description of HERAPDF2.0 at low $x$ and $Q^2$. The effect of adding a simple
higher twist term of the form ~$F_L*A/Q^2$ to the description of $F_L$ is
investigated. This results in a significantly better description of the reduced
cross-sections, $F_2$ and $F_L$ at low $x$, $Q^2$ and a significantly lower
$\chi^2$ for the NNLO fit as compared to the NLO fit. This is not the case if
the higher twist term is added to $F_2$
| [
{
"created": "Fri, 27 May 2016 10:54:27 GMT",
"version": "v1"
}
] | 2016-05-30 | [
[
"Cooper-Sarkar",
"A. M",
""
],
[
"Abt",
"I.",
""
],
[
"Foster",
"B.",
""
],
[
"Wing",
"M.",
""
],
[
"Myronenko",
"V.",
""
],
[
"Wichmann",
"K.",
""
]
] | In the HERAPDF2.0 PDF analysis it was noted that the fit $\chi^2$ worsens significantly at low $Q^2$ for both NLO and NNLO fits. The turn over of the reduced cross section at low-$x$ and low $Q^2$ due to the contribution of the longitudinal cross section $F_L$ is also not very well described. In this paper the prediction for $F_L$ is highlighted and the corresponding extraction of $F_2$ from the data is further investigated, showing discrepancies with description of HERAPDF2.0 at low $x$ and $Q^2$. The effect of adding a simple higher twist term of the form ~$F_L*A/Q^2$ to the description of $F_L$ is investigated. This results in a significantly better description of the reduced cross-sections, $F_2$ and $F_L$ at low $x$, $Q^2$ and a significantly lower $\chi^2$ for the NNLO fit as compared to the NLO fit. This is not the case if the higher twist term is added to $F_2$ |
2003.07374 | Michael Spannowsky | Steven Abel, Nicholas Chancellor and Michael Spannowsky | Quantum Computing for Quantum Tunnelling | 6 pages, 4 figures | Phys. Rev. D 103, 016008 (2021) | 10.1103/PhysRevD.103.016008 | IPPP/20/8 | hep-ph cond-mat.stat-mech hep-th quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We demonstrate how quantum field theory problems can be embedded on quantum
annealers. The general method we use is a discretisation of the field theory
problem into a general Ising model, with the continuous field values being
encoded into Ising spin chains. To illustrate the method, and as a simple proof
of principle, we use a (hybrid) quantum annealer to recover the correct profile
of the thin-wall tunnelling solution. This method is applicable to many
nonperturbative problems.
| [
{
"created": "Mon, 16 Mar 2020 18:00:16 GMT",
"version": "v1"
}
] | 2021-01-20 | [
[
"Abel",
"Steven",
""
],
[
"Chancellor",
"Nicholas",
""
],
[
"Spannowsky",
"Michael",
""
]
] | We demonstrate how quantum field theory problems can be embedded on quantum annealers. The general method we use is a discretisation of the field theory problem into a general Ising model, with the continuous field values being encoded into Ising spin chains. To illustrate the method, and as a simple proof of principle, we use a (hybrid) quantum annealer to recover the correct profile of the thin-wall tunnelling solution. This method is applicable to many nonperturbative problems. |
hep-ph/0612009 | Takahiro Nagai | M. Hirai, S. Kumano, T.-H. Nagai, and K. Sudoh | Determination of fragmentation functions and their uncertainties from e+
+ e- -> h + X data | 4 pages, LaTeX, 5 eps files, to be published in AIP proceedings of
the 17th International Spin Physics Symposium (SPIN2006), Oct. 2-7, 2006,
Kyoto, Japan | AIPConf.Proc.915:749-752,2007 | 10.1063/1.2750887 | KEK-TH-1114 | hep-ph hep-ex nucl-ex nucl-th | null | Fragmentation functions are determined for pions, kaons, and nucleons by a
global analysis of charged-hadron production data in electron-positron
annihilation. The optimum functions are obtained in both leading order (LO) and
next-to-leading order (NLO) of alpha_s. It is important that uncertainties of
the fragmentation functions are estimated in this work by the Hessian method.
We found that the uncertainties are large at small Q^2 and that they are
generally reduced in the NLO in comparison with the LO ones. We supply a code
for calculating the fragmentation functions and their uncertainties for the
pions, kaons, and nucleons at given z and Q^2.
| [
{
"created": "Fri, 1 Dec 2006 13:05:43 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Hirai",
"M.",
""
],
[
"Kumano",
"S.",
""
],
[
"Nagai",
"T. -H.",
""
],
[
"Sudoh",
"K.",
""
]
] | Fragmentation functions are determined for pions, kaons, and nucleons by a global analysis of charged-hadron production data in electron-positron annihilation. The optimum functions are obtained in both leading order (LO) and next-to-leading order (NLO) of alpha_s. It is important that uncertainties of the fragmentation functions are estimated in this work by the Hessian method. We found that the uncertainties are large at small Q^2 and that they are generally reduced in the NLO in comparison with the LO ones. We supply a code for calculating the fragmentation functions and their uncertainties for the pions, kaons, and nucleons at given z and Q^2. |
2301.13562 | Timo Jan{\ss}en | Timo Jan{\ss}en, Daniel Ma\^itre, Steffen Schumann, Frank Siegert,
Henry Truong | Unweighting multijet event generation using factorisation-aware neural
networks | 29 pages, 11 figures, minor revision | SciPost Phys. 15, 107 (2023) | 10.21468/SciPostPhys.15.3.107 | MCNET-23-01, IPPP/23/04 | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | In this article we combine a recently proposed method for factorisation-aware
matrix element surrogates with an unbiased unweighting algorithm. We show that
employing a sophisticated neural network emulation of QCD multijet matrix
elements based on dipole factorisation can lead to a drastic acceleration of
unweighted event generation. We train neural networks for a selection of
partonic channels contributing at the tree-level to $Z+4,5$ jets and
$t\bar{t}+3,4$ jets production at the LHC which necessitates a generalisation
of the dipole emulation model to include initial state partons as well as
massive final state quarks. We also present first steps towards the emulation
of colour-sampled amplitudes. We incorporate these emulations as fast and
accurate surrogates in a two-stage rejection sampling algorithm within the
Sherpa Monte Carlo that yields unbiased unweighted events suitable for
phenomenological analyses and post-processing in experimental workflows, e.g.
as input to a time-consuming detector simulation. For the computational cost of
unweighted events we achieve a reduction by factors between $16$ and $350$ for
the considered channels.
| [
{
"created": "Tue, 31 Jan 2023 11:19:02 GMT",
"version": "v1"
},
{
"created": "Tue, 16 May 2023 16:23:26 GMT",
"version": "v2"
}
] | 2023-09-20 | [
[
"Janßen",
"Timo",
""
],
[
"Maître",
"Daniel",
""
],
[
"Schumann",
"Steffen",
""
],
[
"Siegert",
"Frank",
""
],
[
"Truong",
"Henry",
""
]
] | In this article we combine a recently proposed method for factorisation-aware matrix element surrogates with an unbiased unweighting algorithm. We show that employing a sophisticated neural network emulation of QCD multijet matrix elements based on dipole factorisation can lead to a drastic acceleration of unweighted event generation. We train neural networks for a selection of partonic channels contributing at the tree-level to $Z+4,5$ jets and $t\bar{t}+3,4$ jets production at the LHC which necessitates a generalisation of the dipole emulation model to include initial state partons as well as massive final state quarks. We also present first steps towards the emulation of colour-sampled amplitudes. We incorporate these emulations as fast and accurate surrogates in a two-stage rejection sampling algorithm within the Sherpa Monte Carlo that yields unbiased unweighted events suitable for phenomenological analyses and post-processing in experimental workflows, e.g. as input to a time-consuming detector simulation. For the computational cost of unweighted events we achieve a reduction by factors between $16$ and $350$ for the considered channels. |
1811.07590 | Sebastian Steinbei{\ss}er | Jorge Segovia, Sebastian Steinbei{\ss}er, Antonio Vairo | Electric dipole transitions of $1P$ bottomonia | 21 pages, 17 figures, changes: added appendix, reference removed | Phys. Rev. D 99, 074011 (2019) | 10.1103/PhysRevD.99.074011 | TUM-EFT 86/16 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We compute the electric dipole transitions $\chi_{bJ}(1P)\to
\gamma\Upsilon(1S)$, with $J=0,1,2$, and $h_{b}(1P)\to \gamma\eta_{b}(1S)$ in a
model-independent way. We use potential non-relativistic QCD (pNRQCD) at weak
coupling with either the Coulomb potential or the complete static potential
incorporated in the leading order Hamiltonian. In the last case, the
perturbative series shows very mild scale dependence and a good convergence
pattern, allowing predictions for all the transition widths. Assuming
$\Lambda_{\text{QCD}} \ll mv^2$, the precision that we reach is
$k_{\gamma}^{3}/(mv)^{2} \times \mathcal{O}(v^{2})$, where $k_{\gamma}$ is the
photon energy, $m$ is the mass of the heavy quark and $v$ its relative
velocity. Our results are: $\Gamma(\chi_{b0}(1P)\to \gamma\Upsilon(1S)) =
28^{+2}_{-2}~\text{keV}$, $\Gamma(\chi_{b1}(1P)\to \gamma\Upsilon(1S)) =
37^{+2}_{-2}~\text{keV}$, $\Gamma(\chi_{b2}(1P)\to \gamma\Upsilon(1S)) =
45^{+3}_{-3}~\text{keV}$ and $\Gamma(h_b(1P)\to \gamma\eta_b(1S)) =
63^{+6}_{-6}~\text{keV}$.
| [
{
"created": "Mon, 19 Nov 2018 10:16:12 GMT",
"version": "v1"
},
{
"created": "Tue, 23 Apr 2019 07:48:46 GMT",
"version": "v2"
}
] | 2019-04-24 | [
[
"Segovia",
"Jorge",
""
],
[
"Steinbeißer",
"Sebastian",
""
],
[
"Vairo",
"Antonio",
""
]
] | We compute the electric dipole transitions $\chi_{bJ}(1P)\to \gamma\Upsilon(1S)$, with $J=0,1,2$, and $h_{b}(1P)\to \gamma\eta_{b}(1S)$ in a model-independent way. We use potential non-relativistic QCD (pNRQCD) at weak coupling with either the Coulomb potential or the complete static potential incorporated in the leading order Hamiltonian. In the last case, the perturbative series shows very mild scale dependence and a good convergence pattern, allowing predictions for all the transition widths. Assuming $\Lambda_{\text{QCD}} \ll mv^2$, the precision that we reach is $k_{\gamma}^{3}/(mv)^{2} \times \mathcal{O}(v^{2})$, where $k_{\gamma}$ is the photon energy, $m$ is the mass of the heavy quark and $v$ its relative velocity. Our results are: $\Gamma(\chi_{b0}(1P)\to \gamma\Upsilon(1S)) = 28^{+2}_{-2}~\text{keV}$, $\Gamma(\chi_{b1}(1P)\to \gamma\Upsilon(1S)) = 37^{+2}_{-2}~\text{keV}$, $\Gamma(\chi_{b2}(1P)\to \gamma\Upsilon(1S)) = 45^{+3}_{-3}~\text{keV}$ and $\Gamma(h_b(1P)\to \gamma\eta_b(1S)) = 63^{+6}_{-6}~\text{keV}$. |
hep-ph/0404150 | Johan Bijnens | Johan Bijnens, Pierre Dhonte (Lund) and Pere Talavera (Politecnica
Barcelona) | $\pi K$ Scattering in Three Flavour ChPT | 23 pages | JHEP 0405:036,2004 | 10.1088/1126-6708/2004/05/036 | LU TP 04-19 | hep-ph | null | We present the scattering lengths for the $\pi K$ processes in the three
flavour Chiral Perturbation Theory (ChPT) framework at next-to-next-to-leading
order (NNLO). The calculation has been performed analytically but we only
include analytical results for the dependence on the low-energy constants
(LECs) at NNLO due to the size of the expressions. These results, together with
resonance estimates of the NNLO LECs are used to obtain constraints on the
Zweig rule suppressed LECs at NLO, $L_4^r$ and $L_6^r$. Contrary to
expectations from NLO order calculations we find them to be compatible with
zero. We do a preliminary study of combining the results from $\pi\pi$
scattering, $\pi K$ scattering and the scalar form-factors and find only a
marginal compatibility with all experimental/dispersive input data.
| [
{
"created": "Mon, 19 Apr 2004 09:08:18 GMT",
"version": "v1"
}
] | 2011-03-22 | [
[
"Bijnens",
"Johan",
"",
"Lund"
],
[
"Dhonte",
"Pierre",
"",
"Lund"
],
[
"Talavera",
"Pere",
"",
"Politecnica\n Barcelona"
]
] | We present the scattering lengths for the $\pi K$ processes in the three flavour Chiral Perturbation Theory (ChPT) framework at next-to-next-to-leading order (NNLO). The calculation has been performed analytically but we only include analytical results for the dependence on the low-energy constants (LECs) at NNLO due to the size of the expressions. These results, together with resonance estimates of the NNLO LECs are used to obtain constraints on the Zweig rule suppressed LECs at NLO, $L_4^r$ and $L_6^r$. Contrary to expectations from NLO order calculations we find them to be compatible with zero. We do a preliminary study of combining the results from $\pi\pi$ scattering, $\pi K$ scattering and the scalar form-factors and find only a marginal compatibility with all experimental/dispersive input data. |
2012.14071 | BoQiang Lu | Cheng-Wei Chiang and Bo-Qiang Lu | Testing clockwork axion with gravitational waves | 29 pages, 10 figures, 1 table, comments are welcome | null | 10.1088/1475-7516/2021/05/049 | null | hep-ph gr-qc | http://creativecommons.org/licenses/by-sa/4.0/ | We investigate the gravitational waves (GWs) produced from the Peccei-Quinn
(PQ) phase transition associated with the clockwork axion. The PQ phase
transition can be first-order when the dimension-6 operator is included into
the scalar potential. The GWs from the PQ phase transition at scale in the
range of $10^3-10^6$ GeV are detectable for the BBO and ALIA interferometers.
The LISA and Taiji interferometers can probe the GWs from the PQ scale
$f\lesssim 10^4$ GeV, while the GW signals from the scale $f\gtrsim 10^5$ GeV
can be detected by the ground-based GW observatories ET and CE. We find that
the parameter space $\kappa_m\sim 0.06-0.001$, $\kappa_l\sim 0.04-0.001$, and
$\varepsilon\sim 0.1-0.01$ at the scale $f=10^5$ GeV and most of the parameter
regions at the scale $f=10^6$ GeV have been excluded by the LIGO O2 run. The
LIGO O3 and design phases can further probe the remaining parameter space. We
show that the GWs from the annihilation of domain walls with a PQ scale
$f\simeq 2\times 10^5$ GeV can induce the stochastic signals indicated by the
12.5-year observation of NANOGrav. The LIGO O3 run has the opportunity of
detecting the GW signals from the first-order PQ phase transition around this
scale.
| [
{
"created": "Mon, 28 Dec 2020 02:40:06 GMT",
"version": "v1"
}
] | 2021-05-26 | [
[
"Chiang",
"Cheng-Wei",
""
],
[
"Lu",
"Bo-Qiang",
""
]
] | We investigate the gravitational waves (GWs) produced from the Peccei-Quinn (PQ) phase transition associated with the clockwork axion. The PQ phase transition can be first-order when the dimension-6 operator is included into the scalar potential. The GWs from the PQ phase transition at scale in the range of $10^3-10^6$ GeV are detectable for the BBO and ALIA interferometers. The LISA and Taiji interferometers can probe the GWs from the PQ scale $f\lesssim 10^4$ GeV, while the GW signals from the scale $f\gtrsim 10^5$ GeV can be detected by the ground-based GW observatories ET and CE. We find that the parameter space $\kappa_m\sim 0.06-0.001$, $\kappa_l\sim 0.04-0.001$, and $\varepsilon\sim 0.1-0.01$ at the scale $f=10^5$ GeV and most of the parameter regions at the scale $f=10^6$ GeV have been excluded by the LIGO O2 run. The LIGO O3 and design phases can further probe the remaining parameter space. We show that the GWs from the annihilation of domain walls with a PQ scale $f\simeq 2\times 10^5$ GeV can induce the stochastic signals indicated by the 12.5-year observation of NANOGrav. The LIGO O3 run has the opportunity of detecting the GW signals from the first-order PQ phase transition around this scale. |
1108.3613 | Qing-Hong Cao | Edmond L. Berger, Qing-Hong Cao, Jiang-Hao Yu, C.-P. Yuan | Calculation of Associated Production of a Top Quark and a W' at the LHC | null | Phys. Rev. D84, 095026 (2011) | 10.1103/PhysRevD.84.095026 | ANL-HEP-PR-11-44; MSUHEP-110725; NSF-KITP-11-131 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate collider signatures of a top-philic W' model, in which the W'
boson couples only to the third-generation quarks of the standard model. The
main discovery channel for this W' is through associated production of the W'
and top quark, yielding a top-quark pair plus an extra bottom quark jet as a
signal. We do a full simulation of the signal and relevant backgrounds. We
develop a method of analysis that allows us to conclude that discovery of the
W' is promising at the LHC despite large standard model backgrounds. Bottom
quark tagging of the extra jet is key to suppressing the backgrounds.
| [
{
"created": "Thu, 18 Aug 2011 03:31:25 GMT",
"version": "v1"
}
] | 2011-12-02 | [
[
"Berger",
"Edmond L.",
""
],
[
"Cao",
"Qing-Hong",
""
],
[
"Yu",
"Jiang-Hao",
""
],
[
"Yuan",
"C. -P.",
""
]
] | We investigate collider signatures of a top-philic W' model, in which the W' boson couples only to the third-generation quarks of the standard model. The main discovery channel for this W' is through associated production of the W' and top quark, yielding a top-quark pair plus an extra bottom quark jet as a signal. We do a full simulation of the signal and relevant backgrounds. We develop a method of analysis that allows us to conclude that discovery of the W' is promising at the LHC despite large standard model backgrounds. Bottom quark tagging of the extra jet is key to suppressing the backgrounds. |
hep-ph/9804266 | Oleg Yakovlev | Oleg Yakovlev and Alexander Yelkhovsky | Top quark production near threshold: on resummation of O(
(\beta_0\alpha_s)^n) QCD corrections | LaTeX, 9 pages, 2 ps figures | Phys.Lett. B438 (1998) 341-346 | 10.1016/S0370-2693(98)00985-X | WUE-ITP-98-010 | hep-ph | null | We discuss the resummation of the potentially large O((\beta_0\alpha_s)^n)
QCD corrections to the total cross section of the process e^+e^- \to t \bar t
near the threshold. In this approximation, the cross section factorization into
the short- and long-distance parts is valid. The short-distance correction is
reduced to the production vertex renormalization. It amounts to -9.5% and is
well under control. The long distance corrections are accounted for as the
effect of the coupling's running in the QCD potential. We argue that the
accuracy of present predictions for the cross section in the scheme with the
running QCD coupling is about 10%.
| [
{
"created": "Thu, 9 Apr 1998 15:04:19 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Yakovlev",
"Oleg",
""
],
[
"Yelkhovsky",
"Alexander",
""
]
] | We discuss the resummation of the potentially large O((\beta_0\alpha_s)^n) QCD corrections to the total cross section of the process e^+e^- \to t \bar t near the threshold. In this approximation, the cross section factorization into the short- and long-distance parts is valid. The short-distance correction is reduced to the production vertex renormalization. It amounts to -9.5% and is well under control. The long distance corrections are accounted for as the effect of the coupling's running in the QCD potential. We argue that the accuracy of present predictions for the cross section in the scheme with the running QCD coupling is about 10%. |
hep-ph/0208258 | Wally Melnitchouk | W. Melnitchouk | Quark-hadron duality in electron-pion scattering | 23 pages, 7 figures, to appear in Eur. J. Phys. A | Eur.Phys.J.A17:223-234,2003 | 10.1140/epja/i2003-10006-6 | JLAB-THY-02-34 | hep-ph hep-ex nucl-ex nucl-th | null | We explore the relationship between exclusive and inclusive electromagnetic
scattering from the pion, focusing on the transition region at intermediate
Q^2. Combining Drell-Yan data on the leading twist quark distribution in the
pion with a model for the resonance region at large x, we calculate QCD moments
of the pion structure function over a range of Q^2, and quantify the role of
higher twist corrections. Using a parameterization of the pion elastic form
factor and phenomenological models for the pi -> rho transition form factor, we
further test the extent to which local duality may be valid for the pion.
| [
{
"created": "Wed, 28 Aug 2002 19:29:01 GMT",
"version": "v1"
},
{
"created": "Wed, 2 Apr 2003 15:09:51 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"Melnitchouk",
"W.",
""
]
] | We explore the relationship between exclusive and inclusive electromagnetic scattering from the pion, focusing on the transition region at intermediate Q^2. Combining Drell-Yan data on the leading twist quark distribution in the pion with a model for the resonance region at large x, we calculate QCD moments of the pion structure function over a range of Q^2, and quantify the role of higher twist corrections. Using a parameterization of the pion elastic form factor and phenomenological models for the pi -> rho transition form factor, we further test the extent to which local duality may be valid for the pion. |
1712.00091 | Alexander Ilyichev Dr. | Igor Akushevich and Alexander Ilyichev | Radiative effects in deep virtual Compton scattering | 9 pages, 6 figures | Phys. Rev. D 98, 013005 (2018) | 10.1103/PhysRevD.98.013005 | JLAB-PHY-17-2605 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Radiative corrections to the cross sections of photon electroproduction and
the single spin asymmetries induced by the interference between the Bethe
Heitler and deep virtual Compton scattering amplitudes are calculated within
the leading log approximation. The deep virtual Compton scattering amplitude is
presented in the Belitsky, M\"uller, and Kirchner approximation for the
polarized initial particles. The Fortran code for estimation of the radiative
effects in a given kinematic point and Monte Carlo generator for simulation of
one or two photons are developed. Numerical results are performed for beam-spin
asymmetries in kinematical conditions of current experiments in the Jefferson
Laboratory.
| [
{
"created": "Thu, 30 Nov 2017 21:39:13 GMT",
"version": "v1"
}
] | 2018-07-25 | [
[
"Akushevich",
"Igor",
""
],
[
"Ilyichev",
"Alexander",
""
]
] | Radiative corrections to the cross sections of photon electroproduction and the single spin asymmetries induced by the interference between the Bethe Heitler and deep virtual Compton scattering amplitudes are calculated within the leading log approximation. The deep virtual Compton scattering amplitude is presented in the Belitsky, M\"uller, and Kirchner approximation for the polarized initial particles. The Fortran code for estimation of the radiative effects in a given kinematic point and Monte Carlo generator for simulation of one or two photons are developed. Numerical results are performed for beam-spin asymmetries in kinematical conditions of current experiments in the Jefferson Laboratory. |
1810.06375 | Felipe Rojas Abatte | Bastian D\'iaz S\'aez, Felipe Rojas-Abatte and Alfonso R. Zerwekh | Dark Matter from a Vector Field in the Fundamental Representation of
$SU(2)_L$ | 30 pages, 30 figures, 3 tables | Phys. Rev. D 99, 075026 (2019) | 10.1103/PhysRevD.99.075026 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We explore an extension to the Standard Model which incorporates a vector
field in the fundamental representation of $SU(2)_L$ as the only non-standard
degree of freedom. This kind of field may appear in different scenarios such as
Compositness, Gauge-Higgs unification and extradimensional scenarios. We study
the model in which a $Z_2$ symmetry is manifest, making the neutral CP-even
component of the new vector field a vectorial dark matter candidate. We
constraint the parameter space through LEP and LHC data, as well as from
current dark matter searches. Additionally, comment on the implications of
perturbative unitarity are presented. We find that the model is highly
constrained but a small region of the parameter space can provide a viable DM
candidate. On the other hand, unitarity demands an UV completion at an scale
below 10 TeV. Finally we contrast our predictions on mono-jet, -$Z$, -Higgs
production with the ones obtained in the inert Two Higgs Doublet Model.
| [
{
"created": "Mon, 15 Oct 2018 14:27:20 GMT",
"version": "v1"
}
] | 2019-05-01 | [
[
"Sáez",
"Bastian Díaz",
""
],
[
"Rojas-Abatte",
"Felipe",
""
],
[
"Zerwekh",
"Alfonso R.",
""
]
] | We explore an extension to the Standard Model which incorporates a vector field in the fundamental representation of $SU(2)_L$ as the only non-standard degree of freedom. This kind of field may appear in different scenarios such as Compositness, Gauge-Higgs unification and extradimensional scenarios. We study the model in which a $Z_2$ symmetry is manifest, making the neutral CP-even component of the new vector field a vectorial dark matter candidate. We constraint the parameter space through LEP and LHC data, as well as from current dark matter searches. Additionally, comment on the implications of perturbative unitarity are presented. We find that the model is highly constrained but a small region of the parameter space can provide a viable DM candidate. On the other hand, unitarity demands an UV completion at an scale below 10 TeV. Finally we contrast our predictions on mono-jet, -$Z$, -Higgs production with the ones obtained in the inert Two Higgs Doublet Model. |
hep-ph/0210042 | Nicos Stefanis | A. I. Karanikas (U. of Athens), C. N. Ktorides (U. of Athens), N. G.
Stefanis (U. of Bochum) | World-line techniques for resumming gluon radiative corrections at the
cross-section level | 21 pages, using RevTeX. Three figures as EPS files. To appear in Eur.
Phys. J. C | Eur.Phys.J.C26:445-455,2003 | 10.1140/epjc/s2002-01068-3 | UA/NPPS-2-02, RUB-TPII-03/02 | hep-ph | null | We employ the Polyakov world-line path-integral version of QCD to identify
and resum at leading perturbative order enhanced radiative gluon contributions
to the Drell-Yan type ($q\bar{q}$ pair annihilation) cross-sections. We
emphasize that this is the first time that world-line techniques are applied to
cross-section calculations.
| [
{
"created": "Wed, 2 Oct 2002 17:52:45 GMT",
"version": "v1"
}
] | 2009-01-07 | [
[
"Karanikas",
"A. I.",
"",
"U. of Athens"
],
[
"Ktorides",
"C. N.",
"",
"U. of Athens"
],
[
"Stefanis",
"N. G.",
"",
"U. of Bochum"
]
] | We employ the Polyakov world-line path-integral version of QCD to identify and resum at leading perturbative order enhanced radiative gluon contributions to the Drell-Yan type ($q\bar{q}$ pair annihilation) cross-sections. We emphasize that this is the first time that world-line techniques are applied to cross-section calculations. |
hep-ph/0408358 | Andreas Ipp | Andreas Ipp | Thermodynamics of Deconfined QCD at Small and Large Chemical Potential | 5 pages, to appear in the proceedings of SEWM 2004, Helsinki, 16-19
June 2004 | null | 10.1142/9789812702159_0034 | TUW-04-24 | hep-ph | null | We present large $N_f$ QCD/QED as a test bed for improved pressure
calculations, show how to apply the hints obtained on optimized renormalization
scales at large $N_f$ to finite $N_f=2$, and compare the results to recent
lattice data.
| [
{
"created": "Tue, 31 Aug 2004 15:51:57 GMT",
"version": "v1"
}
] | 2017-08-23 | [
[
"Ipp",
"Andreas",
""
]
] | We present large $N_f$ QCD/QED as a test bed for improved pressure calculations, show how to apply the hints obtained on optimized renormalization scales at large $N_f$ to finite $N_f=2$, and compare the results to recent lattice data. |
hep-ph/9704361 | Joakim Edsjo | J. Edsjo (Uppsala University) and P. Gondolo (Max-Planck-Inttitut fur
Physik) | Neutralino Relic Density including Coannihilations | LaTeX, 14 embedded eps figures, uses epsfig. For paper with full
resolution figures, see http://www.teorfys.uu.se/~edsjo/Welcome.html A few
typos corrected | Phys.Rev.D56:1879-1894,1997 | 10.1103/PhysRevD.56.1879 | UUITP-11/97, MPI-PhT/97-27 | hep-ph astro-ph | null | We evaluate the relic density of the lightest neutralino, the lightest
supersymmetric particle, in the Minimal Supersymmetric extension of the
Standard Model (MSSM). For the first time, we include all coannihilation
processes between neutralinos and charginos for any neutralino mass and
composition. We use the most sophisticated routines for integrating the cross
sections and the Boltzmann equation. We properly treat (sub)threshold and
resonant annihilations. We also include one-loop corrections to neutralino
masses. We find that coannihilation processes are important not only for light
higgsino-like neutralinos, as pointed out before, but also for heavy higgsinos
and for mixed and gaugino-like neutralinos. Indeed, coannihilations should be
included whenever $|\mu| \lsim 2 |M_1|$, independently of the neutralino
composition. When $|\mu| \sim |M_1|$, coannihilations can increase or decrease
the relic density in and out of the cosmologically interesting region. We find
that there is still a window of light higgsino-like neutralinos that are viable
dark matter candidates and that coannihilations shift the cosmological upper
bound on the neutralino mass from 3 to 7 TeV.
| [
{
"created": "Sun, 20 Apr 1997 14:45:48 GMT",
"version": "v1"
},
{
"created": "Wed, 11 Jun 1997 12:33:02 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Edsjo",
"J.",
"",
"Uppsala University"
],
[
"Gondolo",
"P.",
"",
"Max-Planck-Inttitut fur\n Physik"
]
] | We evaluate the relic density of the lightest neutralino, the lightest supersymmetric particle, in the Minimal Supersymmetric extension of the Standard Model (MSSM). For the first time, we include all coannihilation processes between neutralinos and charginos for any neutralino mass and composition. We use the most sophisticated routines for integrating the cross sections and the Boltzmann equation. We properly treat (sub)threshold and resonant annihilations. We also include one-loop corrections to neutralino masses. We find that coannihilation processes are important not only for light higgsino-like neutralinos, as pointed out before, but also for heavy higgsinos and for mixed and gaugino-like neutralinos. Indeed, coannihilations should be included whenever $|\mu| \lsim 2 |M_1|$, independently of the neutralino composition. When $|\mu| \sim |M_1|$, coannihilations can increase or decrease the relic density in and out of the cosmologically interesting region. We find that there is still a window of light higgsino-like neutralinos that are viable dark matter candidates and that coannihilations shift the cosmological upper bound on the neutralino mass from 3 to 7 TeV. |
1901.08018 | Johannes Bl\"umlein | J. Bl\"umlein, A. De Freitas, C.G. Raab and K. Sch\"onwald | The $O(\alpha^2)$ Initial State QED Corrections to $e^+e^-$ Annihilation
to a Neutral Vector Boson Revisited | 4 pages Latex, 2 Figures, several style files | null | 10.1016/j.physletb.2019.02.038 | DESY 18--226, DO--TH 18/30 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We calculate the non-singlet, the pure singlet contribution, and their
interference term, at $O(\alpha^2)$ due to electron-pair initial state
radiation to $e^+ e^-$ annihilation into a neutral vector boson in a direct
analytic computation without any approximation. The correction is represented
in terms of iterated incomplete elliptic integrals. Performing the limit $s \gg
m_e^2$ we find discrepancies with the earlier results of
Ref.~\cite{Berends:1987ab} and confirm results obtained in
Ref.~\cite{Blumlein:2011mi} where the effective method of massive operator
matrix elements has been used, which works for all but the power corrections in
$m^2/s$. In this way, we also confirm the validity of the factorization of
massive partons in the Drell-Yan process. We also add non-logarithmic terms at
$O(\alpha^2)$ which have not been considered in \cite{Berends:1987ab}. The
corrections are of central importance for precision analyzes in $e^+e^-$
annihilation into $\gamma^*/Z^*$ at high luminosity.
| [
{
"created": "Wed, 23 Jan 2019 17:28:24 GMT",
"version": "v1"
}
] | 2019-02-27 | [
[
"Blümlein",
"J.",
""
],
[
"De Freitas",
"A.",
""
],
[
"Raab",
"C. G.",
""
],
[
"Schönwald",
"K.",
""
]
] | We calculate the non-singlet, the pure singlet contribution, and their interference term, at $O(\alpha^2)$ due to electron-pair initial state radiation to $e^+ e^-$ annihilation into a neutral vector boson in a direct analytic computation without any approximation. The correction is represented in terms of iterated incomplete elliptic integrals. Performing the limit $s \gg m_e^2$ we find discrepancies with the earlier results of Ref.~\cite{Berends:1987ab} and confirm results obtained in Ref.~\cite{Blumlein:2011mi} where the effective method of massive operator matrix elements has been used, which works for all but the power corrections in $m^2/s$. In this way, we also confirm the validity of the factorization of massive partons in the Drell-Yan process. We also add non-logarithmic terms at $O(\alpha^2)$ which have not been considered in \cite{Berends:1987ab}. The corrections are of central importance for precision analyzes in $e^+e^-$ annihilation into $\gamma^*/Z^*$ at high luminosity. |
1502.07952 | Javier Rubio | Javier Rubio | Higgs inflation and vacuum stability | 11 pages, 14 figures, contribution to proceedings DISCRETE 2014 | null | 10.1088/1742-6596/631/1/012032 | null | hep-ph astro-ph.CO gr-qc | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Inflation is nowadays a well-established paradigm consistent with all the
observations. The precise nature of the inflaton is however unknown and its
role could be played by any candidate able to imitate a scalar condensate in
the slow-roll regime. The discovery of a fundamental scalar in the LHC provides
the less speculative candidate. Could the Higgs field itself be responsible for
inflation? Do we really need to advocate new physics to explain the properties
of the Universe at large scales? Which is the relation between the Standard
Model parameters and the inflationary observables? What happens if our vacuum
becomes unstable below the scale of inflation? We present an overview of Higgs
inflation trying to provide answers to the previous questions with special
emphasis on the vacuum stability issue.
| [
{
"created": "Fri, 27 Feb 2015 16:19:47 GMT",
"version": "v1"
}
] | 2015-09-02 | [
[
"Rubio",
"Javier",
""
]
] | Inflation is nowadays a well-established paradigm consistent with all the observations. The precise nature of the inflaton is however unknown and its role could be played by any candidate able to imitate a scalar condensate in the slow-roll regime. The discovery of a fundamental scalar in the LHC provides the less speculative candidate. Could the Higgs field itself be responsible for inflation? Do we really need to advocate new physics to explain the properties of the Universe at large scales? Which is the relation between the Standard Model parameters and the inflationary observables? What happens if our vacuum becomes unstable below the scale of inflation? We present an overview of Higgs inflation trying to provide answers to the previous questions with special emphasis on the vacuum stability issue. |
hep-ph/9811465 | Mikhail Bilenky | Mikhail Bilenky, German Rodrigo and Arcadi Santamaria | NLO calculations of the three-jet heavy quark production in
e^+e^--annihilation: status and applications | LaTeX, 5 pages, 6 figures, uses ltwol2e.sty Reference to Phys.Lett.
B418(1998)430 is corrected. Contribution to the XXIX International Conference
on High Energy Physics, (Vancouver, Canada, July 1998) | null | null | FTUV/98-79, IFIC/98-80 | hep-ph | null | Next-to-leading order calculations for heavy quark three-jet production in
e+e- annihilation are reviewed. Their applications for the measurement of the
b-quark mass at LEP/SLC and for the test of flavour independence of the strong
coupling constant are discussed.
| [
{
"created": "Wed, 25 Nov 1998 10:25:28 GMT",
"version": "v1"
},
{
"created": "Sun, 24 Jan 1999 21:10:03 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Bilenky",
"Mikhail",
""
],
[
"Rodrigo",
"German",
""
],
[
"Santamaria",
"Arcadi",
""
]
] | Next-to-leading order calculations for heavy quark three-jet production in e+e- annihilation are reviewed. Their applications for the measurement of the b-quark mass at LEP/SLC and for the test of flavour independence of the strong coupling constant are discussed. |
hep-ph/9906487 | Ed Stoeffhaas | V. Barger, S. Geer, and K. Whisnant | Long Baseline Neutrino Physics with a Muon Storage Ring Neutrino Source | 38 pages, Revtex with epsf.sty, 21 postscript figures. Minor text
revisions, some new numbers in Tables II and III | Phys.Rev.D61:053004,2000 | 10.1103/PhysRevD.61.053004 | FERMILAB-Pub-99-187-T, MADPH-99-1122, AMES-HET-99-05 | hep-ph hep-ex | null | We examine the physics capabilities of known flavor neutrino beams from
intense muon sources. We find that long-baseline neutrino experiments based on
such beams can provide precise measurements of neutrino oscillation mass and
mixing parameters. Furthermore, they can test whether the dominant atmospheric
neutrino oscillations are \nu_\mu --> \nu_\tau and/or \nu_\mu --> \nu_s,
determine the \nu_\mu --> \nu_e content of atmospheric neutrino oscillations,
and measure \nu_e --> \nu_\tau appearance. Depending on the oscillation
parameters, they may be able to detect Earth matter and CP violation effects
and to determine the ordering of some of the mass eigenstates.
| [
{
"created": "Thu, 24 Jun 1999 17:02:48 GMT",
"version": "v1"
},
{
"created": "Fri, 30 Jul 1999 19:01:17 GMT",
"version": "v2"
}
] | 2009-09-25 | [
[
"Barger",
"V.",
""
],
[
"Geer",
"S.",
""
],
[
"Whisnant",
"K.",
""
]
] | We examine the physics capabilities of known flavor neutrino beams from intense muon sources. We find that long-baseline neutrino experiments based on such beams can provide precise measurements of neutrino oscillation mass and mixing parameters. Furthermore, they can test whether the dominant atmospheric neutrino oscillations are \nu_\mu --> \nu_\tau and/or \nu_\mu --> \nu_s, determine the \nu_\mu --> \nu_e content of atmospheric neutrino oscillations, and measure \nu_e --> \nu_\tau appearance. Depending on the oscillation parameters, they may be able to detect Earth matter and CP violation effects and to determine the ordering of some of the mass eigenstates. |
1609.03527 | Wen Yin | Wen Yin | Fixed Point and Anomaly Mediation in Partially $N = 2$ Supersymmetric
Standard Models | 27 pages, 4 figures, v3 typo corrected | Chinese Physics C Vol. 42, No. 1 (2018) 013104 | 10.1088/1674-1137/42/1/013104 | TU-1029 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Motivated by the simple toroidal compactification of extra-dimensional SUSY
theories, we investigate on a partially $N=2$ supersymmetric (SUSY) extension
of the standard model which has an $N=2$ SUSY sector and an $N=1$ SUSY sector.
We point out that below the scale of the partially breaking of $N=2$ to $N=1$,
the ratio of Yukawa to gauge couplings embedded in the original $N=2$ gauge
interaction in the $N=2$ sector becomes greater due to a fixed point. Since at
the partially breaking scale the sfermion masses in the $N=2$ sector is
suppressed due to the $N=2$ non-renormalization theorem, the anomaly mediation
effect becomes important. If dominant, the anomaly induced masses for the
sfermions in the $N=2$ sector are almost UV-insensitive due to the fixed point.
Interestingly, these masses are always positive, i.e. no tachyonic slepton
problem. From an example model, we show interesting phenomena differing from
the ordinary MSSM. In particular, the dark matter can be a sbino, i.e. the
scalar component of the $N=2$ vector multiplet of $\rm U(1)_Y$. To obtain the
correct dark matter abundance, the mass of sbino, as well as the MSSM
sparticles in the $N=2$ sector which have a typical mass pattern of anomaly
mediation, is required to be small. Therefore, this scenario can be tested and
confirmed in the LHC and may be further confirmed by the measurement of the
$N=2$ Yukawa couplings in future colliders. This model can explain dark matter,
muon $g-2$ anomaly, gauge coupling unification and relaxes some ordinary
problems within the MSSM. Also, it is compatible with thermal leptogenesis.
| [
{
"created": "Mon, 12 Sep 2016 18:59:03 GMT",
"version": "v1"
},
{
"created": "Fri, 3 Nov 2017 17:25:47 GMT",
"version": "v2"
},
{
"created": "Tue, 12 Dec 2017 15:14:31 GMT",
"version": "v3"
}
] | 2017-12-13 | [
[
"Yin",
"Wen",
""
]
] | Motivated by the simple toroidal compactification of extra-dimensional SUSY theories, we investigate on a partially $N=2$ supersymmetric (SUSY) extension of the standard model which has an $N=2$ SUSY sector and an $N=1$ SUSY sector. We point out that below the scale of the partially breaking of $N=2$ to $N=1$, the ratio of Yukawa to gauge couplings embedded in the original $N=2$ gauge interaction in the $N=2$ sector becomes greater due to a fixed point. Since at the partially breaking scale the sfermion masses in the $N=2$ sector is suppressed due to the $N=2$ non-renormalization theorem, the anomaly mediation effect becomes important. If dominant, the anomaly induced masses for the sfermions in the $N=2$ sector are almost UV-insensitive due to the fixed point. Interestingly, these masses are always positive, i.e. no tachyonic slepton problem. From an example model, we show interesting phenomena differing from the ordinary MSSM. In particular, the dark matter can be a sbino, i.e. the scalar component of the $N=2$ vector multiplet of $\rm U(1)_Y$. To obtain the correct dark matter abundance, the mass of sbino, as well as the MSSM sparticles in the $N=2$ sector which have a typical mass pattern of anomaly mediation, is required to be small. Therefore, this scenario can be tested and confirmed in the LHC and may be further confirmed by the measurement of the $N=2$ Yukawa couplings in future colliders. This model can explain dark matter, muon $g-2$ anomaly, gauge coupling unification and relaxes some ordinary problems within the MSSM. Also, it is compatible with thermal leptogenesis. |
0710.4749 | Ansgar Denner | Mariano Ciccolini, Ansgar Denner and Stefan Dittmaier | Electroweak and QCD corrections to Higgs production via vector-boson
fusion at the LHC | 33 pages, LaTeX, 24 postscript figures | Phys.Rev.D77:013002,2008 | 10.1103/PhysRevD.77.013002 | MPP-2007-152, PSI-PR-07-06, UWThPh-2007-26 | hep-ph | null | The radiative corrections of the strong and electroweak interactions are
calculated at next-to-leading order for Higgs-boson production in the
weak-boson-fusion channel at hadron colliders. Specifically, the calculation
includes all weak-boson fusion and quark--antiquark annihilation diagrams to
Higgs-boson production in association with two hard jets, including all
corresponding interferences. The results on the QCD corrections confirm that
previously made approximations of neglecting s-channel diagrams and
interferences are well suited for predictions of Higgs production with
dedicated vector-boson fusion cuts at the LHC. The electroweak corrections,
which also include real corrections from incoming photons and leading
heavy-Higgs-boson effects at two-loop order, are of the same size as the QCD
corrections, viz. typically at the level of 5-10% for a Higgs-boson mass up to
\sim 700 GeV. In general, both types of corrections do not simply rescale
differential distributions, but induce distortions at the level of 10%. The
discussed corrections have been implemented in a flexible Monte Carlo event
generator.
| [
{
"created": "Thu, 25 Oct 2007 10:26:59 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Ciccolini",
"Mariano",
""
],
[
"Denner",
"Ansgar",
""
],
[
"Dittmaier",
"Stefan",
""
]
] | The radiative corrections of the strong and electroweak interactions are calculated at next-to-leading order for Higgs-boson production in the weak-boson-fusion channel at hadron colliders. Specifically, the calculation includes all weak-boson fusion and quark--antiquark annihilation diagrams to Higgs-boson production in association with two hard jets, including all corresponding interferences. The results on the QCD corrections confirm that previously made approximations of neglecting s-channel diagrams and interferences are well suited for predictions of Higgs production with dedicated vector-boson fusion cuts at the LHC. The electroweak corrections, which also include real corrections from incoming photons and leading heavy-Higgs-boson effects at two-loop order, are of the same size as the QCD corrections, viz. typically at the level of 5-10% for a Higgs-boson mass up to \sim 700 GeV. In general, both types of corrections do not simply rescale differential distributions, but induce distortions at the level of 10%. The discussed corrections have been implemented in a flexible Monte Carlo event generator. |
0712.2966 | Nils Lavesson | Nils Lavesson, Leif Lonnblad | Merging parton showers and matrix elements -- back to basics | null | JHEP 0804:085,2008 | 10.1088/1126-6708/2008/04/085 | LU-TP 07-38 | hep-ph | null | We make a thorough comparison between different schemes of merging
fixed-order tree-level matrix element generators with parton-shower models. We
use the most basic benchmark of the O(alpha_S) correction to e+e- -> jets,
where the simple kinematics allows us to study in detail the transition between
the matrix-element and parton-shower regions. We find that the CKKW-based
schemes give a reasonably smooth transition between these regions, although
problems may occur if the parton shower used is not ordered in transverse
momentum. However, the so-called Pseudo-Shower and MLM schemes turn out to have
potentially serious problems due to different scale definitions in different
regions of phase space, and due to sensitivity to the details in the initial
conditions of the parton shower programs used.
| [
{
"created": "Tue, 18 Dec 2007 14:09:55 GMT",
"version": "v1"
},
{
"created": "Wed, 23 Apr 2008 09:11:56 GMT",
"version": "v2"
}
] | 2009-04-30 | [
[
"Lavesson",
"Nils",
""
],
[
"Lonnblad",
"Leif",
""
]
] | We make a thorough comparison between different schemes of merging fixed-order tree-level matrix element generators with parton-shower models. We use the most basic benchmark of the O(alpha_S) correction to e+e- -> jets, where the simple kinematics allows us to study in detail the transition between the matrix-element and parton-shower regions. We find that the CKKW-based schemes give a reasonably smooth transition between these regions, although problems may occur if the parton shower used is not ordered in transverse momentum. However, the so-called Pseudo-Shower and MLM schemes turn out to have potentially serious problems due to different scale definitions in different regions of phase space, and due to sensitivity to the details in the initial conditions of the parton shower programs used. |
2305.03102 | Reuven Balkin | Akitaka Ariga, Reuven Balkin, Iftah Galon, Enrique Kajomovitz and
Yotam Soreq | Hunting muonic forces at emulsion detectors | 13 pages + appendices, 11 figures | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | Only two types of Standard Model particles are able to propagate the
$480\,$meters separating the ATLAS interaction point and FASER: neutrinos and
muons. Furthermore, muons are copiously produced in proton collisions. We
propose to use FASER$\nu$ as a muon fixed target experiment in order to search
for new bosonic degrees of freedom coupled predominantly to muons. These muon
force carriers are particularly interesting in light of the recent measurement
of the muon anomalous magnetic moment. Using a novel analysis technique, we
show that even in the current LHC run, FASER$\nu$ could potentially probe
previously unexplored parts of the parameter space. In the high-luminosity
phase of the LHC, we find that the improved sensitivity of FASER$\nu2$ will
probe unexplored parameter space and may be competitive with dedicated search
proposals.
| [
{
"created": "Thu, 4 May 2023 18:35:33 GMT",
"version": "v1"
}
] | 2023-05-08 | [
[
"Ariga",
"Akitaka",
""
],
[
"Balkin",
"Reuven",
""
],
[
"Galon",
"Iftah",
""
],
[
"Kajomovitz",
"Enrique",
""
],
[
"Soreq",
"Yotam",
""
]
] | Only two types of Standard Model particles are able to propagate the $480\,$meters separating the ATLAS interaction point and FASER: neutrinos and muons. Furthermore, muons are copiously produced in proton collisions. We propose to use FASER$\nu$ as a muon fixed target experiment in order to search for new bosonic degrees of freedom coupled predominantly to muons. These muon force carriers are particularly interesting in light of the recent measurement of the muon anomalous magnetic moment. Using a novel analysis technique, we show that even in the current LHC run, FASER$\nu$ could potentially probe previously unexplored parts of the parameter space. In the high-luminosity phase of the LHC, we find that the improved sensitivity of FASER$\nu2$ will probe unexplored parameter space and may be competitive with dedicated search proposals. |
hep-ph/0402211 | Luca Trentadue | A. B. Arbuzov, D. Haidt, C. Matteuzzi, M. Paganoni and L. Trentadue | The running of the electromagnetic coupling alpha in small-angle Bhabha
scattering | 15 pages, 3 Postscript figures | Eur.Phys.J. C34 (2004) 267-275 | 10.1140/epjc/s2004-01649-0 | CERN-PH-TH/2004-016 | hep-ph | null | A method to determine the running of alpha from a measurement of small-angle
Bhabha scattering is proposed and worked out. The method is suited to high
statistics experiments at e+e- colliders, which are equipped with luminometers
in the appropriate angular region. A new simulation code predicting small-angle
Bhabha scattering is also presented
| [
{
"created": "Thu, 19 Feb 2004 17:37:20 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Arbuzov",
"A. B.",
""
],
[
"Haidt",
"D.",
""
],
[
"Matteuzzi",
"C.",
""
],
[
"Paganoni",
"M.",
""
],
[
"Trentadue",
"L.",
""
]
] | A method to determine the running of alpha from a measurement of small-angle Bhabha scattering is proposed and worked out. The method is suited to high statistics experiments at e+e- colliders, which are equipped with luminometers in the appropriate angular region. A new simulation code predicting small-angle Bhabha scattering is also presented |
hep-ph/0703059 | Gergely G\'abor Barnaf\"oldi | G.G. Barnafoldi, P. Levai, G. Fai, G. Papp, B.A. Cole | Does the Cronin Peak Disappear at LHC Energies? | 6 Pages, 4 figure, Contribution to the Quark Matter 2006 | Int.J.Mod.Phys.E16:1923-1929,2007 | 10.1142/S0218301307007234 | null | hep-ph | null | In this work we compare the nuclear modification factors in proton (deuteron)
-- nucleus collisions at CERN SPS, FNAL and RHIC energies in a wide p_T range.
In these experiments the nuclear modification factor has shown an enhancement
at p_T ~ 4 GeV/c. The height of this "Cronin peak" depends on the c.m. energy
of the collision, as it is subject to stronger shadowing at higher energies.
One of the aims of this contribution is to analyze the shadowing phenomenon at
lower (2 GeV/c < p_T < 4 GeV/c) and intermediate (4 GeV/c < p_T < 8 GeV/c)
transverse momentum. Different shadowing parameterizations are considered and
the obtained Cronin peaks are investigated at RHIC and LHC energies.
| [
{
"created": "Tue, 6 Mar 2007 02:17:23 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Barnafoldi",
"G. G.",
""
],
[
"Levai",
"P.",
""
],
[
"Fai",
"G.",
""
],
[
"Papp",
"G.",
""
],
[
"Cole",
"B. A.",
""
]
] | In this work we compare the nuclear modification factors in proton (deuteron) -- nucleus collisions at CERN SPS, FNAL and RHIC energies in a wide p_T range. In these experiments the nuclear modification factor has shown an enhancement at p_T ~ 4 GeV/c. The height of this "Cronin peak" depends on the c.m. energy of the collision, as it is subject to stronger shadowing at higher energies. One of the aims of this contribution is to analyze the shadowing phenomenon at lower (2 GeV/c < p_T < 4 GeV/c) and intermediate (4 GeV/c < p_T < 8 GeV/c) transverse momentum. Different shadowing parameterizations are considered and the obtained Cronin peaks are investigated at RHIC and LHC energies. |
1704.03382 | Hiroshi Okada | Takaaki Nomura, Hiroshi Okada | Loop suppressed light fermion masses with $U(1)_R$ gauge symmetry | 27 pages, 3 figures, 4 tables: version accepted for publication in
Physical Review D | Phys. Rev. D 96, 015016 (2017) | 10.1103/PhysRevD.96.015016 | KIAS-P17023 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose a model with two Higgs doublet where quark and charged-lepton
masses in the first and second families are induced at one-loop level, and
neutrino masses are induced at the two-loop level. In our model we introduce an
extra $U(1)_R$ gauge symmetry that plays a crucial role in achieving desired
terms in no conflict with anomaly cancellation. We show the mechanism to
generate fermion masses, the resultant mass matrices and Yukawa interactions in
mass eigenstates, and discuss several interesting phenomenologies such as muon
anomalous magnetic dipole moment and dark matter candidate that are arisen from
this model.
| [
{
"created": "Tue, 11 Apr 2017 15:57:09 GMT",
"version": "v1"
},
{
"created": "Thu, 22 Jun 2017 18:09:04 GMT",
"version": "v2"
}
] | 2017-07-19 | [
[
"Nomura",
"Takaaki",
""
],
[
"Okada",
"Hiroshi",
""
]
] | We propose a model with two Higgs doublet where quark and charged-lepton masses in the first and second families are induced at one-loop level, and neutrino masses are induced at the two-loop level. In our model we introduce an extra $U(1)_R$ gauge symmetry that plays a crucial role in achieving desired terms in no conflict with anomaly cancellation. We show the mechanism to generate fermion masses, the resultant mass matrices and Yukawa interactions in mass eigenstates, and discuss several interesting phenomenologies such as muon anomalous magnetic dipole moment and dark matter candidate that are arisen from this model. |
1410.4323 | Aiichi Iwazaki | A. Iwazaki | Axion Stars and Fast Radio Bursts | 4 pages, no figure | null | 10.1103/PhysRevD.91.023008 | Nisho-3-2014 | hep-ph astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We show that fast radio bursts arise from collisions between axion stars and
neutron stars. The bursts are emitted in the atmosphere of the neutron stars.
The observed frequencies of the bursts are given by the axion mass $m_a$ such
as $m_a/2\pi\simeq 1.4\,\mbox{GHz}\,\big(m_a/(6\times 10^{-6}\mbox{eV})\big)$.
From the event rate $\sim 10^{-3}$ per year in a galaxy, we can determine the
mass $\sim 10^{-11}M_{\odot}$ of the axion stars. Using these values we can
explain short durations ( $\sim $ms ) and amount of radiation energies ( $\sim
10^{43}$GeV ) of the bursts.
| [
{
"created": "Thu, 16 Oct 2014 08:00:34 GMT",
"version": "v1"
},
{
"created": "Thu, 23 Oct 2014 02:45:03 GMT",
"version": "v2"
}
] | 2015-06-23 | [
[
"Iwazaki",
"A.",
""
]
] | We show that fast radio bursts arise from collisions between axion stars and neutron stars. The bursts are emitted in the atmosphere of the neutron stars. The observed frequencies of the bursts are given by the axion mass $m_a$ such as $m_a/2\pi\simeq 1.4\,\mbox{GHz}\,\big(m_a/(6\times 10^{-6}\mbox{eV})\big)$. From the event rate $\sim 10^{-3}$ per year in a galaxy, we can determine the mass $\sim 10^{-11}M_{\odot}$ of the axion stars. Using these values we can explain short durations ( $\sim $ms ) and amount of radiation energies ( $\sim 10^{43}$GeV ) of the bursts. |
1109.5448 | Shinya Matsuzaki | Shinya Matsuzaki and Koichi Yamawaki | Techni-dilaton signatures at LHC | latex, 14 pages, 5 eps figure files; version to appear in PTP | Prog. Theor. Phys. 127 (2012), 209-228 | 10.1143/PTP.127.209 | MISC-2011-15 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We explore discovery signatures of techni-dilaton (TD) at LHC. The TD was
predicted long ago as a composite pseudo Nambu-Goldstone boson (pNGB)
associated with the spontaneous breaking of the approximate scale symmetry in
the walking technicolor (WTC). Being pNGB, whose mass arises from the explicit
scale-symmetry breaking due to the dynamical mass generation, the TD should
have a mass MTD lighter than other techni-hadrons, say MTD \simeq 600GeV for
the typical WTC model, which is well in the discovery range of the ongoing LHC
experiment. We develop a spurion method of nonlinear realization to calculate
the TD couplings to the standard model (SM) particles and explicitly evaluate
the TD LHC production cross sections at sqrt{s}=7TeV times the branching ratios
in terms of MTD as an input parameter for 200GeV<MTD<1TeV in the typical WTC
models: one-doublet model (1DM) and one-family model (1FM). It turns out that
the TD signatures are quite different from those of the SM Higgs. We compare
the TD->WW/ZZ signature with the recent ATLAS and CMS bounds and find that in
the case of 1DM the signature is consistent over the whole mass range due to
the large suppression of TD couplings, and by the same token the signal is too
tiny for the TD to be visible through this channel at LHC. As for the 1FM, on
the other hand, a severe constraint is given on MTD to exclude the TD with
MTD<600GeV, which, however, would imply an emergence of somewhat dramatic
excess as the TD signature at MTD>600GeV in the near future. We further find a
characteristic signature coming from the gamma gamma mode in the 1FM. In sharp
contrast to the SM Higgs case, it provides highly enhanced cross
section~0.10--1.0fb at around MTD \simeq 600GeV, which is large enough to be
discovered during the first few year's run at LHC.
| [
{
"created": "Mon, 26 Sep 2011 05:26:27 GMT",
"version": "v1"
},
{
"created": "Wed, 28 Dec 2011 09:10:18 GMT",
"version": "v2"
}
] | 2012-03-03 | [
[
"Matsuzaki",
"Shinya",
""
],
[
"Yamawaki",
"Koichi",
""
]
] | We explore discovery signatures of techni-dilaton (TD) at LHC. The TD was predicted long ago as a composite pseudo Nambu-Goldstone boson (pNGB) associated with the spontaneous breaking of the approximate scale symmetry in the walking technicolor (WTC). Being pNGB, whose mass arises from the explicit scale-symmetry breaking due to the dynamical mass generation, the TD should have a mass MTD lighter than other techni-hadrons, say MTD \simeq 600GeV for the typical WTC model, which is well in the discovery range of the ongoing LHC experiment. We develop a spurion method of nonlinear realization to calculate the TD couplings to the standard model (SM) particles and explicitly evaluate the TD LHC production cross sections at sqrt{s}=7TeV times the branching ratios in terms of MTD as an input parameter for 200GeV<MTD<1TeV in the typical WTC models: one-doublet model (1DM) and one-family model (1FM). It turns out that the TD signatures are quite different from those of the SM Higgs. We compare the TD->WW/ZZ signature with the recent ATLAS and CMS bounds and find that in the case of 1DM the signature is consistent over the whole mass range due to the large suppression of TD couplings, and by the same token the signal is too tiny for the TD to be visible through this channel at LHC. As for the 1FM, on the other hand, a severe constraint is given on MTD to exclude the TD with MTD<600GeV, which, however, would imply an emergence of somewhat dramatic excess as the TD signature at MTD>600GeV in the near future. We further find a characteristic signature coming from the gamma gamma mode in the 1FM. In sharp contrast to the SM Higgs case, it provides highly enhanced cross section~0.10--1.0fb at around MTD \simeq 600GeV, which is large enough to be discovered during the first few year's run at LHC. |
hep-ph/9608206 | Stephen Davis | Anne-Christine Davis and Stephen C. Davis (DAMTP, UK) | Microphysics of SO(10) Cosmic Strings | 34 pages, LATEX. Replaced version is restructured, and has small
correction to fermion zero mode analysis. To be published in Physical Review
D | Phys.Rev. D55 (1997) 1879-1895 | 10.1103/PhysRevD.55.1879 | DAMTP/96-72 | hep-ph | null | We uncover a rich microphysical structure for SO(10) cosmic strings. For the
abelian string the electroweak symmetry is restored around it in a region
depending on the electroweak scale. A rich structure of nonabelian strings is
found. Some of these also restore the electroweak symmetry. We investigate the
zero mode structure of our strings. Whilst there are right handed neutrino zero
modes for the abelian string, they do not survive the electroweak phase
transition. In general the nonabelian strings do not have fermion zero modes.
We consider the generalisation of our results to other theories and consider
cosmological consequences of them.
| [
{
"created": "Thu, 1 Aug 1996 15:54:50 GMT",
"version": "v1"
},
{
"created": "Fri, 7 Feb 1997 14:27:07 GMT",
"version": "v2"
}
] | 2009-10-28 | [
[
"Davis",
"Anne-Christine",
"",
"DAMTP, UK"
],
[
"Davis",
"Stephen C.",
"",
"DAMTP, UK"
]
] | We uncover a rich microphysical structure for SO(10) cosmic strings. For the abelian string the electroweak symmetry is restored around it in a region depending on the electroweak scale. A rich structure of nonabelian strings is found. Some of these also restore the electroweak symmetry. We investigate the zero mode structure of our strings. Whilst there are right handed neutrino zero modes for the abelian string, they do not survive the electroweak phase transition. In general the nonabelian strings do not have fermion zero modes. We consider the generalisation of our results to other theories and consider cosmological consequences of them. |
2305.16609 | Hongxia Huang | Ye Yan, Yuheng Wu, Hongxia Huang, Jialun Ping and Xinmei Zhu | Prediction of charmed-bottom pentaquarks in quark model | 12 pages, 3 figures | null | 10.1140/epjc/s10052-023-11810-6 | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | Inspired by the fully heavy tetraquark states reported by the LHCb, ATLAS and
CMS Collaborations, we perform a systemical investigation of the low-lying
fully heavy pentaquark systems composed of charm and bottom quarks (anti-quark)
in the chiral quark model. With the help of the channel-coupling, we obtain
several fully heavy pentaquark candidates, which are $cccc\bar{b}$ and
$bbbb\bar{c}$ systems with $J^P = 1/2^-$ and $3/2^-$, $cccb\bar{c}$,
$bbbc\bar{b}$, $cccb\bar{b}$ and $bbbc\bar{c}$ systems with $J^P = 5/2^-$. The
binding energies of these states are all below 10 MeV and the root mean square
(RMS) are around 1.8 fm, which indicates that these states are likely to be
molecular states. These predicted exotic states may provide new ideas for
experimental searches and we expect more experimental and theoretical
researches to study and understand the fully heavy states in future.
| [
{
"created": "Fri, 26 May 2023 04:02:51 GMT",
"version": "v1"
}
] | 2023-08-02 | [
[
"Yan",
"Ye",
""
],
[
"Wu",
"Yuheng",
""
],
[
"Huang",
"Hongxia",
""
],
[
"Ping",
"Jialun",
""
],
[
"Zhu",
"Xinmei",
""
]
] | Inspired by the fully heavy tetraquark states reported by the LHCb, ATLAS and CMS Collaborations, we perform a systemical investigation of the low-lying fully heavy pentaquark systems composed of charm and bottom quarks (anti-quark) in the chiral quark model. With the help of the channel-coupling, we obtain several fully heavy pentaquark candidates, which are $cccc\bar{b}$ and $bbbb\bar{c}$ systems with $J^P = 1/2^-$ and $3/2^-$, $cccb\bar{c}$, $bbbc\bar{b}$, $cccb\bar{b}$ and $bbbc\bar{c}$ systems with $J^P = 5/2^-$. The binding energies of these states are all below 10 MeV and the root mean square (RMS) are around 1.8 fm, which indicates that these states are likely to be molecular states. These predicted exotic states may provide new ideas for experimental searches and we expect more experimental and theoretical researches to study and understand the fully heavy states in future. |
1404.5061 | Feng Luo | Nishita Desai, John Ellis, Feng Luo and Jad Marrouche | Closing in on the Tip of the CMSSM Stau Coannihilation Strip | 19 pages, 6 figures. Fig. 1 and the corresponding text are changed
due to the updated ATLAS result (ref.[16]). More details of our simulation
are provided in Section 3.1. The caption of Fig. 6 and the corresponding text
are changed. Matches the published version | null | 10.1103/PhysRevD.90.055031 | KCL-PH-TH/2014-13; LCTS/2014-13; CERN-PH-TH/2014-060 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Near the tip of the stau coannihilation strip in the CMSSM with a neutralino
LSP, the astrophysical cold dark matter density constraint forces the
stau-neutralino mass difference to be small. If this mass difference is smaller
than the tau mass, the stau may decay either in the outer part of an LHC
detector - the `disappearing track' signature - or be sufficiently long-lived
to leave the detector before decaying - the long-lived massive charged-particle
signature. We combine searches for these signatures with conventional missing
transverse energy searches during LHC Run 1, identifying the small remaining
parts of the CMSSM stau coannihilation strip region that have not yet been
excluded, and discussing how they may be explored during Run 2 of the LHC.
| [
{
"created": "Sun, 20 Apr 2014 18:08:59 GMT",
"version": "v1"
},
{
"created": "Sun, 21 Sep 2014 12:11:14 GMT",
"version": "v2"
}
] | 2015-06-19 | [
[
"Desai",
"Nishita",
""
],
[
"Ellis",
"John",
""
],
[
"Luo",
"Feng",
""
],
[
"Marrouche",
"Jad",
""
]
] | Near the tip of the stau coannihilation strip in the CMSSM with a neutralino LSP, the astrophysical cold dark matter density constraint forces the stau-neutralino mass difference to be small. If this mass difference is smaller than the tau mass, the stau may decay either in the outer part of an LHC detector - the `disappearing track' signature - or be sufficiently long-lived to leave the detector before decaying - the long-lived massive charged-particle signature. We combine searches for these signatures with conventional missing transverse energy searches during LHC Run 1, identifying the small remaining parts of the CMSSM stau coannihilation strip region that have not yet been excluded, and discussing how they may be explored during Run 2 of the LHC. |
0907.4091 | Adi Armoni | Adi Armoni | The Conformal Window from the Worldline Formalism | 14 pages. 4 eps figures. v2: refs. added. To appear in Nuclear
Physics B | Nucl.Phys.B826:328-336,2010 | 10.1016/j.nuclphysb.2009.10.010 | null | hep-ph hep-lat hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We use the worldline formalism to derive a universal relation for the lower
boundary of the conformal window in non-supersymmetric QCD-like theories. The
derivation relies on the convergence of the expansion of the fermionic
determinant in terms of Wilson loops. The expansion shares a similarity with
the lattice strong coupling expansion and the genus expansion in string theory.
Our result relates the lower boundary of the conformal window in theories with
different representations and different gauge groups. Finally, we use SQCD to
estimate the boundary of the conformal window in QCD-like theories and compare
it with other approaches.
| [
{
"created": "Thu, 23 Jul 2009 14:58:11 GMT",
"version": "v1"
},
{
"created": "Fri, 9 Oct 2009 13:00:39 GMT",
"version": "v2"
}
] | 2009-11-18 | [
[
"Armoni",
"Adi",
""
]
] | We use the worldline formalism to derive a universal relation for the lower boundary of the conformal window in non-supersymmetric QCD-like theories. The derivation relies on the convergence of the expansion of the fermionic determinant in terms of Wilson loops. The expansion shares a similarity with the lattice strong coupling expansion and the genus expansion in string theory. Our result relates the lower boundary of the conformal window in theories with different representations and different gauge groups. Finally, we use SQCD to estimate the boundary of the conformal window in QCD-like theories and compare it with other approaches. |
1907.06473 | Hee Sok Chung | Nora Brambilla, Hee Sok Chung, Wai Kin Lai, Vladyslav Shtabovenko,
Antonio Vairo | Order $v^4$ corrections to Higgs boson decay into $J/\psi + \gamma$ | 40 pages, 2 figures, minor corrections, version published in Phys.
Rev. D | Phys. Rev. D 100, 054038 (2019) | 10.1103/PhysRevD.100.054038 | TUM-EFT 123/19, P3H-19-016, TTP19-019 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The process $H \to J/\psi + \gamma$, where $H$ is the Higgs particle,
provides a way to probe the size and the sign of the Higgs-charm coupling. In
order to improve the theoretical control of the decay rate, we compute order
$v^4$ corrections to the decay rate based on the nonrelativistic QCD
factorization formalism. The perturbative calculation is carried out by using
automated computer codes. We also resum logarithms of the ratio of the masses
of the Higgs boson and the $J/\psi$ to all orders in the strong coupling
constant $\alpha_s$ to next-to-leading logarithmic accuracy. In our numerical
result for the decay rate, we improve the theoretical uncertainty, while our
central value is in agreement with previous studies within errors. We also
present numerical results for $H \to \Upsilon(nS) + \gamma$ for $n=1,2$, and 3,
which turn out to be extremely sensitive to the Higgs bottom coupling.
| [
{
"created": "Mon, 15 Jul 2019 12:46:39 GMT",
"version": "v1"
},
{
"created": "Thu, 26 Sep 2019 16:06:39 GMT",
"version": "v2"
}
] | 2019-09-27 | [
[
"Brambilla",
"Nora",
""
],
[
"Chung",
"Hee Sok",
""
],
[
"Lai",
"Wai Kin",
""
],
[
"Shtabovenko",
"Vladyslav",
""
],
[
"Vairo",
"Antonio",
""
]
] | The process $H \to J/\psi + \gamma$, where $H$ is the Higgs particle, provides a way to probe the size and the sign of the Higgs-charm coupling. In order to improve the theoretical control of the decay rate, we compute order $v^4$ corrections to the decay rate based on the nonrelativistic QCD factorization formalism. The perturbative calculation is carried out by using automated computer codes. We also resum logarithms of the ratio of the masses of the Higgs boson and the $J/\psi$ to all orders in the strong coupling constant $\alpha_s$ to next-to-leading logarithmic accuracy. In our numerical result for the decay rate, we improve the theoretical uncertainty, while our central value is in agreement with previous studies within errors. We also present numerical results for $H \to \Upsilon(nS) + \gamma$ for $n=1,2$, and 3, which turn out to be extremely sensitive to the Higgs bottom coupling. |
hep-ph/9503311 | Chi-Sing Lam | Y.J. Feng and C.S. Lam | DIAGRAMMATIC ANALYSIS OF QCD GAUGE TRANSFORMATIONS AND GAUGE
CANCELLATIONS | Latex, with 40 diagrams in a uuencoded postscript file. 27 pages in
total. | Phys.Rev. D53 (1996) 2115-2127 | 10.1103/PhysRevD.53.2115 | McGill/95--12 | hep-ph hep-th | null | Diagrammatic techniques are invented to implement QCD gauge transformations.
These techniques can be used to discover how gauge-dependent terms are
cancelled among diagrams to yield gauge-invariant results in the sum. In this
way a multiloop pinching technique can be developed to change ordinary vertices
into background-gauge vertices. The techniques can also be used to design new
gauges to simplify calculations by reducing the number of gauge-dependent terms
present in the intermediate steps. Two examples are discussed to illustrate
this aspect of the applications.
| [
{
"created": "Mon, 13 Mar 1995 15:43:55 GMT",
"version": "v1"
}
] | 2016-09-01 | [
[
"Feng",
"Y. J.",
""
],
[
"Lam",
"C. S.",
""
]
] | Diagrammatic techniques are invented to implement QCD gauge transformations. These techniques can be used to discover how gauge-dependent terms are cancelled among diagrams to yield gauge-invariant results in the sum. In this way a multiloop pinching technique can be developed to change ordinary vertices into background-gauge vertices. The techniques can also be used to design new gauges to simplify calculations by reducing the number of gauge-dependent terms present in the intermediate steps. Two examples are discussed to illustrate this aspect of the applications. |
0802.4143 | Naoki Yamamoto | Tetsuo Hatsuda, Motoi Tachibana, Naoki Yamamoto | Spectral Continuity in Dense QCD | 4 pages, 3 figures; version to appear in Phys. Rev. D | Phys.Rev.D78:011501,2008 | 10.1103/PhysRevD.78.011501 | TKYNT-08-01, SAGA-HE-241 | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The vector mesons in three-flavor quark matter with chiral and diquark
condensates are studied using the in-medium QCD sum rules. The diquark
condensate leads to a mass splitting between the flavor-octet and
flavor-singlet channels. At high density, the singlet vector meson disappears
from the low-energy spectrum, while the octet vector mesons survive as light
excitations with a mass comparable to the fermion gap. A possible connection
between the light gluonic modes and the flavor-octet vector mesons at high
density is also discussed.
| [
{
"created": "Thu, 28 Feb 2008 08:37:18 GMT",
"version": "v1"
},
{
"created": "Mon, 30 Jun 2008 08:13:44 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Hatsuda",
"Tetsuo",
""
],
[
"Tachibana",
"Motoi",
""
],
[
"Yamamoto",
"Naoki",
""
]
] | The vector mesons in three-flavor quark matter with chiral and diquark condensates are studied using the in-medium QCD sum rules. The diquark condensate leads to a mass splitting between the flavor-octet and flavor-singlet channels. At high density, the singlet vector meson disappears from the low-energy spectrum, while the octet vector mesons survive as light excitations with a mass comparable to the fermion gap. A possible connection between the light gluonic modes and the flavor-octet vector mesons at high density is also discussed. |
2405.09363 | Zhicheng Liu | Zhen-hua Zhao and Zhi-Cheng Liu | Tri-resonant leptogenesis from modular symmetry neutrino models | null | null | null | null | hep-ph | http://creativecommons.org/licenses/by-nc-nd/4.0/ | In this paper, we have studied the consequences of some representative
modular symmetry neutrino models for tri-resonant leptogenesis (which is
realized by having three nearly degenerate right-handed neutrinos). To be
specific, we have considered modular ${\rm A}^{}_4$, ${\rm S}^{}_4$ and ${\rm
A}^{}_5$ symmetry models that have a right-handed neutrino mass matrix
$M^{}_{\rm R}$ as shown in Eq.~(\ref{5}) which gives three degenerate
right-handed neutrino masses and consequently prohibits the leptogenesis
mechanism to work. For these models, we have considered two minimal ways to
generate the desired small mass splittings among the three right-handed
neutrinos: one scenario is to modify $M^{}_{\rm R}$ to a form as shown in
Eq.~(\ref{7}), while another scenario is to consider the renormalization-group
corrections for the right-handed neutrino masses. In the former scenario, for
the considered models, the observed value of $\eta^{}_{\rm B}$ can always be
successfully reproduced for appropriate values of $\mu$. But in the latter
scenario not all the considered models can successfully reproduce the observed
value of $\eta^{}_{\rm B}$.
| [
{
"created": "Wed, 15 May 2024 14:16:48 GMT",
"version": "v1"
}
] | 2024-05-16 | [
[
"Zhao",
"Zhen-hua",
""
],
[
"Liu",
"Zhi-Cheng",
""
]
] | In this paper, we have studied the consequences of some representative modular symmetry neutrino models for tri-resonant leptogenesis (which is realized by having three nearly degenerate right-handed neutrinos). To be specific, we have considered modular ${\rm A}^{}_4$, ${\rm S}^{}_4$ and ${\rm A}^{}_5$ symmetry models that have a right-handed neutrino mass matrix $M^{}_{\rm R}$ as shown in Eq.~(\ref{5}) which gives three degenerate right-handed neutrino masses and consequently prohibits the leptogenesis mechanism to work. For these models, we have considered two minimal ways to generate the desired small mass splittings among the three right-handed neutrinos: one scenario is to modify $M^{}_{\rm R}$ to a form as shown in Eq.~(\ref{7}), while another scenario is to consider the renormalization-group corrections for the right-handed neutrino masses. In the former scenario, for the considered models, the observed value of $\eta^{}_{\rm B}$ can always be successfully reproduced for appropriate values of $\mu$. But in the latter scenario not all the considered models can successfully reproduce the observed value of $\eta^{}_{\rm B}$. |
hep-ph/0611076 | Carlo Ewerz | Carlo Ewerz, Otto Nachtmann | Bounds on Ratios of DIS Structure Functions from the Color Dipole
Picture | 10 pages, 4 figures; v2: comments and reference added, journal
version | Phys.Lett.B648:279-283,2007 | 10.1016/j.physletb.2007.03.028 | ECT*-06-18, HD-THEP-06-29 | hep-ph hep-ex | null | We derive bounds on ratios of deep inelastic nucleon structure functions from
the color dipole picture of high energy photon-hadron scattering. We find an
upper bound on the ratio R=sigma_L/sigma_T of the total cross sections for
longitudinally and transversely polarized photons. We further obtain bounds on
the ratio of deep inelastic structure functions F_2 taken at the same energy
but at different photon virtualities. It is shown that these bounds can be used
to constrain the range of applicability of the dipole picture.
| [
{
"created": "Tue, 7 Nov 2006 18:53:26 GMT",
"version": "v1"
},
{
"created": "Tue, 5 Jun 2007 10:25:03 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Ewerz",
"Carlo",
""
],
[
"Nachtmann",
"Otto",
""
]
] | We derive bounds on ratios of deep inelastic nucleon structure functions from the color dipole picture of high energy photon-hadron scattering. We find an upper bound on the ratio R=sigma_L/sigma_T of the total cross sections for longitudinally and transversely polarized photons. We further obtain bounds on the ratio of deep inelastic structure functions F_2 taken at the same energy but at different photon virtualities. It is shown that these bounds can be used to constrain the range of applicability of the dipole picture. |
1509.06060 | Kei Yagyu | Shinya Kanemura, Kei Yagyu | Unitarity bound in the most general two Higgs doublet model | Version published in Physics Letters B | null | null | UT-HET 107 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate unitarity bounds in the most general two Higgs doublet model
without a discrete $Z_2$ symmetry nor CP conservation. S-wave amplitudes for
two-body elastic scatterings of Nambu-Goldstone bosons and physical Higgs
bosons are calculated at high energies for all possible initial and final
states (14 neutral, 8 singly-charged and 3 doubly-charged states). We obtain
analytic formulae for the block-diagonalized scattering matrix by the
classification of the two body scattering states using the conserved quantum
numbers at high energies. Imposing the condition of perturbative unitarity to
the eigenvalues of the scattering matrix, constraints on the model parameters
can be obtained. We apply our results to constrain the mass range of the
next--to--lightest Higgs state in the model.
| [
{
"created": "Sun, 20 Sep 2015 21:35:36 GMT",
"version": "v1"
},
{
"created": "Sun, 18 Oct 2015 18:12:36 GMT",
"version": "v2"
},
{
"created": "Tue, 1 Dec 2015 09:33:53 GMT",
"version": "v3"
}
] | 2015-12-02 | [
[
"Kanemura",
"Shinya",
""
],
[
"Yagyu",
"Kei",
""
]
] | We investigate unitarity bounds in the most general two Higgs doublet model without a discrete $Z_2$ symmetry nor CP conservation. S-wave amplitudes for two-body elastic scatterings of Nambu-Goldstone bosons and physical Higgs bosons are calculated at high energies for all possible initial and final states (14 neutral, 8 singly-charged and 3 doubly-charged states). We obtain analytic formulae for the block-diagonalized scattering matrix by the classification of the two body scattering states using the conserved quantum numbers at high energies. Imposing the condition of perturbative unitarity to the eigenvalues of the scattering matrix, constraints on the model parameters can be obtained. We apply our results to constrain the mass range of the next--to--lightest Higgs state in the model. |
2110.13011 | Vitaly Beylin | V. Beylin, V. Kuksa, M. Bezuglov, D. Sopin | The multicomponent dark matter structure and its possible observed
manifestations | This paper will be published in Proceedings of the 24th Bled Workshop
"What Comes Beyond Standard Models", 2021 yr | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the framework of hypercolor extension of the Standard Model having
vectorlike hyperquarks and two stable dark matter candidates originated from
different hyper-currents, we consider some effects which result from reactions
with participation of the dark matter components. Namely, there are decays of
charged hyperpions into leptons and neutral component, annihilation and
transitions of heavy dark matter candidates into the light ones. In the last
case, low energy photon radiation from intermediate charged states is possible.
This type of the dark matter luminescence is analyzed in more detail.
| [
{
"created": "Mon, 25 Oct 2021 14:50:32 GMT",
"version": "v1"
}
] | 2021-10-26 | [
[
"Beylin",
"V.",
""
],
[
"Kuksa",
"V.",
""
],
[
"Bezuglov",
"M.",
""
],
[
"Sopin",
"D.",
""
]
] | In the framework of hypercolor extension of the Standard Model having vectorlike hyperquarks and two stable dark matter candidates originated from different hyper-currents, we consider some effects which result from reactions with participation of the dark matter components. Namely, there are decays of charged hyperpions into leptons and neutral component, annihilation and transitions of heavy dark matter candidates into the light ones. In the last case, low energy photon radiation from intermediate charged states is possible. This type of the dark matter luminescence is analyzed in more detail. |
hep-ph/9909509 | null | S. Kasuya and M. Kawasaki | Q-ball Formation through Affleck-Dine Mechanism | 4 pages, RevTex, 3 postscript figures included, the published version | Phys.Rev.D61:041301,2000 | 10.1103/PhysRevD.61.041301 | null | hep-ph | null | We present the full nonlinear calculation of the formation of a Q-ball
through the Affleck-Dine (AD) mechanism by numerical simulations. It is shown
that large Q-balls are actually produced by the fragmentation of the condensate
of a scalar field whose potential is very flat. We find that the typical size
of a Q-ball is determined by the most developed mode of linearized
fluctuations, and almost all the initial charges which the AD condensate
carries are absorbed into the formed Q-balls, whose sizes and the charges
depend only on the initial charge densities.
| [
{
"created": "Sat, 25 Sep 1999 09:25:47 GMT",
"version": "v1"
},
{
"created": "Wed, 6 Oct 1999 08:17:38 GMT",
"version": "v2"
},
{
"created": "Mon, 28 Feb 2000 09:04:41 GMT",
"version": "v3"
}
] | 2009-12-30 | [
[
"Kasuya",
"S.",
""
],
[
"Kawasaki",
"M.",
""
]
] | We present the full nonlinear calculation of the formation of a Q-ball through the Affleck-Dine (AD) mechanism by numerical simulations. It is shown that large Q-balls are actually produced by the fragmentation of the condensate of a scalar field whose potential is very flat. We find that the typical size of a Q-ball is determined by the most developed mode of linearized fluctuations, and almost all the initial charges which the AD condensate carries are absorbed into the formed Q-balls, whose sizes and the charges depend only on the initial charge densities. |
hep-ph/0607296 | Matthew Schwartz | Christian W. Bauer and Matthew D. Schwartz | Event Generation from Effective Field Theory | 42 pages, 3 figures | Phys.Rev.D76:074004,2007 | 10.1103/PhysRevD.76.074004 | null | hep-ph | null | A procedure is developed for using Soft Collinear Effective Theory (SCET) to
generate fully exclusive events, which can then be compared to data from
collider experiments. We show that SCET smoothly interpolates between QCD for
hard emissions, and the parton shower for soft emissions, while resumming all
large logarithms. In SCET, logarithms are resummed using the renormalization
group, instead of classical Sudakov factors, so subleading logarithms can be
resummed as well. In addition, all loop effects of QCD can be reproduced in
SCET, which allows the effective theory to incorporate next-to-leading and
higher-order effects. We also show through SCET that in the soft/collinear
limit, successive branchings factorize, a fact which is essential to parton
showers, and that the splitting functions of QCD are reproduced. Finally,
combining these results, we present a example of an algorithm that incorporates
the SCET results into an event generator which is systematically improvable.
| [
{
"created": "Thu, 27 Jul 2006 14:48:25 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Bauer",
"Christian W.",
""
],
[
"Schwartz",
"Matthew D.",
""
]
] | A procedure is developed for using Soft Collinear Effective Theory (SCET) to generate fully exclusive events, which can then be compared to data from collider experiments. We show that SCET smoothly interpolates between QCD for hard emissions, and the parton shower for soft emissions, while resumming all large logarithms. In SCET, logarithms are resummed using the renormalization group, instead of classical Sudakov factors, so subleading logarithms can be resummed as well. In addition, all loop effects of QCD can be reproduced in SCET, which allows the effective theory to incorporate next-to-leading and higher-order effects. We also show through SCET that in the soft/collinear limit, successive branchings factorize, a fact which is essential to parton showers, and that the splitting functions of QCD are reproduced. Finally, combining these results, we present a example of an algorithm that incorporates the SCET results into an event generator which is systematically improvable. |
1910.09663 | Digesh Raut | Nobuchika Okada and Digesh Raut | Hunting Inflaton at FASER | 8 pages, 4 figures, (updated) version to be published in PRD | Phys. Rev. D 103, 055022 (2021) | 10.1103/PhysRevD.103.055022 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We explore a possibility that an inflaton, which drives the cosmological
inflation in the early Universe, can be detected by the recently approved FASER
at the High-Luminosity LHC (HL-LHC). We consider nonminimal quartic inflation
scenario in the minimal U(1)$_X$ extension of the Standard Model (SM) with the
classical conformal invariance, where the inflaton is identified with the
U(1)$_X$ Higgs field ($\phi$). By virtue of the classical conformal invariance
and the radiative U(1)$_X$ symmetry breaking via the Coleman-Weinberg
mechanism, the inflationary predictions (in particular, the tensor-to-scaler
ratio ($r$)), the U(1)$_X$ coupling ($g_X$) and the U(1)$_X$ gauge boson mass
($m_{Z^\prime}$), are all determined by only two free parameters, the inflaton
mass ($m_\phi$) and its mixing angle ($\theta$) with the SM Higgs field. The
FASER can search for the inflaton for the parameter ranges of $0.1 \lesssim
m_\phi[{\rm GeV}] \lesssim 4$ and $10^{-5} \lesssim \theta \lesssim 10^{-3}$.
Because of the direct connection among $r$, $g_X$ and $m_{Z^\prime}$, the
$Z^\prime$ boson resonance search at the HL-LHC and the future measurement of
the primordial gravitational wave are complementary to the inflaton search at
the FASER.
| [
{
"created": "Mon, 21 Oct 2019 21:17:48 GMT",
"version": "v1"
},
{
"created": "Mon, 28 Oct 2019 17:32:17 GMT",
"version": "v2"
},
{
"created": "Sun, 7 Mar 2021 20:27:45 GMT",
"version": "v3"
}
] | 2021-04-07 | [
[
"Okada",
"Nobuchika",
""
],
[
"Raut",
"Digesh",
""
]
] | We explore a possibility that an inflaton, which drives the cosmological inflation in the early Universe, can be detected by the recently approved FASER at the High-Luminosity LHC (HL-LHC). We consider nonminimal quartic inflation scenario in the minimal U(1)$_X$ extension of the Standard Model (SM) with the classical conformal invariance, where the inflaton is identified with the U(1)$_X$ Higgs field ($\phi$). By virtue of the classical conformal invariance and the radiative U(1)$_X$ symmetry breaking via the Coleman-Weinberg mechanism, the inflationary predictions (in particular, the tensor-to-scaler ratio ($r$)), the U(1)$_X$ coupling ($g_X$) and the U(1)$_X$ gauge boson mass ($m_{Z^\prime}$), are all determined by only two free parameters, the inflaton mass ($m_\phi$) and its mixing angle ($\theta$) with the SM Higgs field. The FASER can search for the inflaton for the parameter ranges of $0.1 \lesssim m_\phi[{\rm GeV}] \lesssim 4$ and $10^{-5} \lesssim \theta \lesssim 10^{-3}$. Because of the direct connection among $r$, $g_X$ and $m_{Z^\prime}$, the $Z^\prime$ boson resonance search at the HL-LHC and the future measurement of the primordial gravitational wave are complementary to the inflaton search at the FASER. |
2006.03956 | Loutfy Abou Salem L.I. Abou-Salem | R. Hussien, Sh. M. Sewailem and L. I. Abou-Salem | Study of the ground state energies of some nuclei using hybrid model | null | null | null | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The quark-quark QQ interaction as a perturbed term to the nucleon-nucleon
interaction NN without any coupling between them is studied in a hybrid model.
This model is used to calculate the ground-state energies of 2H1 and 4He2
nuclei. In a semi-relativistic framework, this model is encouraged for light
nuclei and the instanton induced interaction by using the QQ potential and the
NN interaction for a small scale around the hadron boundaries. This hybrid
model depends on two theories, the one-boson exchange potential OBEP and the
Cornell-dressed potential CDP for QQ. A small effect of quark-quark interaction
is obtained on the values of the ground state energies, around 6.7 for 2H1 and
1.2 for 4He2 by using the considered hybrid model.
| [
{
"created": "Sat, 6 Jun 2020 19:53:35 GMT",
"version": "v1"
},
{
"created": "Sun, 8 Aug 2021 17:06:11 GMT",
"version": "v2"
},
{
"created": "Tue, 10 Aug 2021 01:02:07 GMT",
"version": "v3"
}
] | 2021-08-11 | [
[
"Hussien",
"R.",
""
],
[
"Sewailem",
"Sh. M.",
""
],
[
"Abou-Salem",
"L. I.",
""
]
] | The quark-quark QQ interaction as a perturbed term to the nucleon-nucleon interaction NN without any coupling between them is studied in a hybrid model. This model is used to calculate the ground-state energies of 2H1 and 4He2 nuclei. In a semi-relativistic framework, this model is encouraged for light nuclei and the instanton induced interaction by using the QQ potential and the NN interaction for a small scale around the hadron boundaries. This hybrid model depends on two theories, the one-boson exchange potential OBEP and the Cornell-dressed potential CDP for QQ. A small effect of quark-quark interaction is obtained on the values of the ground state energies, around 6.7 for 2H1 and 1.2 for 4He2 by using the considered hybrid model. |
hep-ph/0102058 | Yasuhiro Okada | Yasuhiro Okada (KEK) | Higgs and SUSY Higgs bosons at future linear collider | 14 page, 4 figures, Talk given at Linear Collider Workshop 2000,
October 24 -28, 2000, Fermilab | null | 10.1063/1.1394309 | KEK-TH-745 | hep-ph | null | Theoretical overview on phenomenology of Higgs boson and SUSY Higgs boson at
a future linear collider experiment is given as a Higgs and SUSY Higgs working
group summary report for LCWS 2000.
| [
{
"created": "Tue, 6 Feb 2001 06:35:23 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Okada",
"Yasuhiro",
"",
"KEK"
]
] | Theoretical overview on phenomenology of Higgs boson and SUSY Higgs boson at a future linear collider experiment is given as a Higgs and SUSY Higgs working group summary report for LCWS 2000. |
hep-ph/9712369 | Cesareo A. Dominguez | C. A. Dominguez, L. Pirovano, and K. Schilcher | The strange-quark mass from QCD sum rules in the pseudoscalar channel | 10 pages. Latex file. 2 Figures obtained from author CAD upon request | Phys.Lett.B425:193-198,1998 | 10.1016/S0370-2693(98)00222-6 | UCT-TP-246/97 | hep-ph | null | QCD Laplace transform sum rules, involving the axial-vector current
divergences, are used in order to determine the strange quark mass. The
two-point function is known in QCD up to four loops in perturbation theory, and
up to dimension-six in the non-perturbative sector. The hadronic spectral
function is reconstructed using threshold normalization from chiral symmetry,
together with experimental data for the two radial excitations of the kaon. The
result for the running strange quark mass, in the $\bar{MS}$ scheme at a scale
of 1 ${GeV}^{2}$ is: ${\bar m}_{s}(1 GeV^{2}) = 155 \pm 25 {MeV}$.
| [
{
"created": "Sat, 13 Dec 1997 15:47:15 GMT",
"version": "v1"
}
] | 2009-09-25 | [
[
"Dominguez",
"C. A.",
""
],
[
"Pirovano",
"L.",
""
],
[
"Schilcher",
"K.",
""
]
] | QCD Laplace transform sum rules, involving the axial-vector current divergences, are used in order to determine the strange quark mass. The two-point function is known in QCD up to four loops in perturbation theory, and up to dimension-six in the non-perturbative sector. The hadronic spectral function is reconstructed using threshold normalization from chiral symmetry, together with experimental data for the two radial excitations of the kaon. The result for the running strange quark mass, in the $\bar{MS}$ scheme at a scale of 1 ${GeV}^{2}$ is: ${\bar m}_{s}(1 GeV^{2}) = 155 \pm 25 {MeV}$. |
1501.02625 | Ernesto A. Matute | Ernesto A. Matute | Neutrino mass generation with extra right-handed fields in a Dirac
scenario via the type-I seesaw mechanism | 12 pages | Mod. Phys. Lett. A 29 (2014) 1450212 | 10.1142/S0217732314502125 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | An extension of the Standard Model (SM) is studied in which two right-handed
(RH) neutrinos per generation are incorporated, but considering the hypothesis
of the symmetry of lepton and quark contents in order to deprive the number of
RH neutrinos of freedom, generate Dirac neutrinos and accommodate naturally
tiny values for their masses. The high scale type-I seesaw regime is applied to
the first, ordinary RH neutrino, whereas a low scale pseudo-Dirac scenario is
used for the second, adulterant RH neutrino, implying that the first RH
neutrino decouples at the high scale, while the second RH neutrino survives
down to the low scale to pair off in a Dirac-like form with the corresponding
left-handed (LH) neutrino. The small mass and couplings of this extra RH
neutrino are explained by means of the statement of the symmetry of fermionic
content, only regarded as a guideline to the natural choice of parameters since
it is not a proper symmetry in the Lagrangian.
| [
{
"created": "Mon, 12 Jan 2015 12:50:58 GMT",
"version": "v1"
}
] | 2015-01-13 | [
[
"Matute",
"Ernesto A.",
""
]
] | An extension of the Standard Model (SM) is studied in which two right-handed (RH) neutrinos per generation are incorporated, but considering the hypothesis of the symmetry of lepton and quark contents in order to deprive the number of RH neutrinos of freedom, generate Dirac neutrinos and accommodate naturally tiny values for their masses. The high scale type-I seesaw regime is applied to the first, ordinary RH neutrino, whereas a low scale pseudo-Dirac scenario is used for the second, adulterant RH neutrino, implying that the first RH neutrino decouples at the high scale, while the second RH neutrino survives down to the low scale to pair off in a Dirac-like form with the corresponding left-handed (LH) neutrino. The small mass and couplings of this extra RH neutrino are explained by means of the statement of the symmetry of fermionic content, only regarded as a guideline to the natural choice of parameters since it is not a proper symmetry in the Lagrangian. |
1807.02392 | Anna Tokareva | Dmitry Gorbunov, Anna Tokareva | Scalaron the healer: removing the strong-coupling in the Higgs- and
Higgs-dilaton inflations | Journal version | null | 10.1016/j.physletb.2018.11.015 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We show that introducing $R^2$-term makes the Higgs-inflation and
Higgs-dilaton inflation consistent models: the strong coupling energy scales in
scalar, gauge and gravity sectors all are lifted up to the Planck scale.
| [
{
"created": "Fri, 6 Jul 2018 13:11:54 GMT",
"version": "v1"
},
{
"created": "Mon, 10 Dec 2018 20:18:06 GMT",
"version": "v2"
}
] | 2018-12-12 | [
[
"Gorbunov",
"Dmitry",
""
],
[
"Tokareva",
"Anna",
""
]
] | We show that introducing $R^2$-term makes the Higgs-inflation and Higgs-dilaton inflation consistent models: the strong coupling energy scales in scalar, gauge and gravity sectors all are lifted up to the Planck scale. |
1606.01350 | Vadim Guzey | V. Guzey (PNPI, Gatchina) and M. Klasen (Muenster U.) | A fresh look at factorization breaking in diffractive photoproduction of
dijets at HERA at next-to-leading order QCD | 9 pages, 4 figures. Final published version | null | 10.1140/epjc/s10052-016-4304-5 | MS-TP-16-15 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We calculate the cross section of diffractive dijet photoproduction in $ep$
scattering at next-to-leading order (NLO) of perturbative QCD (pQCD), which we
supplement by a model of factorization breaking for the resolved-photon
contribution. In this model, the suppression depends on the flavor and momentum
fraction of the partons in the photon. We show that within experimental and
theoretical uncertainties, the resulting approach provides a good description
of the available HERA data in most of the bins. Hence, taken together with the
observation that NLO pQCD explains well the data on diffractive photoproduction
of open charm in $ep$ scattering, our model of factorization breaking presents
a viable alternative to the scheme based on the global suppression factor.
| [
{
"created": "Sat, 4 Jun 2016 09:17:05 GMT",
"version": "v1"
},
{
"created": "Wed, 24 Aug 2016 08:22:07 GMT",
"version": "v2"
}
] | 2016-09-21 | [
[
"Guzey",
"V.",
"",
"PNPI, Gatchina"
],
[
"Klasen",
"M.",
"",
"Muenster U."
]
] | We calculate the cross section of diffractive dijet photoproduction in $ep$ scattering at next-to-leading order (NLO) of perturbative QCD (pQCD), which we supplement by a model of factorization breaking for the resolved-photon contribution. In this model, the suppression depends on the flavor and momentum fraction of the partons in the photon. We show that within experimental and theoretical uncertainties, the resulting approach provides a good description of the available HERA data in most of the bins. Hence, taken together with the observation that NLO pQCD explains well the data on diffractive photoproduction of open charm in $ep$ scattering, our model of factorization breaking presents a viable alternative to the scheme based on the global suppression factor. |
hep-ph/0307111 | Hee-Jung Lee | Hee-Jung Lee, Byung-Yoon Park, Mannque Rho, Vicente Vento | The Pion Velocity in Dense Skyrmion Matter | 11 pages, 4 figures; added references, changed content | Nucl.Phys.A741:161-178,2004 | 10.1016/j.nuclphysa.2004.06.010 | null | hep-ph nucl-th | null | We have developed a field theory formalism to calculate $in$-$medium$
properties of hadrons within a unified approach that exploits a single
Lagrangian to describe simultaneously both matter background and meson
fluctuations. In this paper we discuss the consequences on physical observables
of a possible phase transition of hadronic matter taking place in the chiral
limit. We pay special attention to the pion velocity $v_\pi$, which controls,
through a dispersion relation, the pion propagation in the hadronic medium. The
$v_\pi$ is defined in terms of parameters related to the matrix element in
matter of the axial-vector current, namely, the in-medium pion decay constants,
$f_t$ and $f_s$. Both of the pion decay constants change dramatically with
density and even vanish in the chiral limit when chiral symmetry is restored,
but the pion velocity does not go to zero, decreasing at most 10% over the
whole density range studied. A possible pseudogap structure is indicated.
| [
{
"created": "Tue, 8 Jul 2003 11:38:37 GMT",
"version": "v1"
},
{
"created": "Thu, 10 Jul 2003 16:09:34 GMT",
"version": "v2"
},
{
"created": "Tue, 11 May 2004 14:08:41 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Lee",
"Hee-Jung",
""
],
[
"Park",
"Byung-Yoon",
""
],
[
"Rho",
"Mannque",
""
],
[
"Vento",
"Vicente",
""
]
] | We have developed a field theory formalism to calculate $in$-$medium$ properties of hadrons within a unified approach that exploits a single Lagrangian to describe simultaneously both matter background and meson fluctuations. In this paper we discuss the consequences on physical observables of a possible phase transition of hadronic matter taking place in the chiral limit. We pay special attention to the pion velocity $v_\pi$, which controls, through a dispersion relation, the pion propagation in the hadronic medium. The $v_\pi$ is defined in terms of parameters related to the matrix element in matter of the axial-vector current, namely, the in-medium pion decay constants, $f_t$ and $f_s$. Both of the pion decay constants change dramatically with density and even vanish in the chiral limit when chiral symmetry is restored, but the pion velocity does not go to zero, decreasing at most 10% over the whole density range studied. A possible pseudogap structure is indicated. |
1110.6507 | Asmaa Abada | A. Abada | Flavour Violation in charged leptons: Present and Future | 8 pages, 6 figures; to appear in C. R. Physique (2011) | null | 10.1016/j.crhy.2011.09.006 | LPT-Orsay 11-80 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the absence of a fundamental principle preventing charged lepton flavour
violation, one expects that extensions of the Standard Model accommodating
neutrino masses and mixings should also allow for charged lepton flavour
violating processes such as $\ell_i \to \ell_j\gamma$, $\ell_i \to \ell_j
\ell_k \ell_m $ and $\mu - e$ conversion in nuclei, for which the rates depend
in general on the mechanism of neutrino mass generation. In addition to
low-energy experiments, there are also searches for lepton flavour violation at
colliders, where new physics can be directly probed through flavour violating
production and/or decays of heavy states. In a model independent way, we
briefly use effective operators responsible for these processes to derive
information about the underlying framework of new physics. We then consider
some specific classes of models (supersymmetry, extra dimensions, grand unified
theories) that account for rich scenarios of charged lepton flavour violation.
We also comment on the r\^ole of charged lepton flavour violation in
disentangling models of new physics.
| [
{
"created": "Sat, 29 Oct 2011 08:56:41 GMT",
"version": "v1"
}
] | 2015-06-03 | [
[
"Abada",
"A.",
""
]
] | In the absence of a fundamental principle preventing charged lepton flavour violation, one expects that extensions of the Standard Model accommodating neutrino masses and mixings should also allow for charged lepton flavour violating processes such as $\ell_i \to \ell_j\gamma$, $\ell_i \to \ell_j \ell_k \ell_m $ and $\mu - e$ conversion in nuclei, for which the rates depend in general on the mechanism of neutrino mass generation. In addition to low-energy experiments, there are also searches for lepton flavour violation at colliders, where new physics can be directly probed through flavour violating production and/or decays of heavy states. In a model independent way, we briefly use effective operators responsible for these processes to derive information about the underlying framework of new physics. We then consider some specific classes of models (supersymmetry, extra dimensions, grand unified theories) that account for rich scenarios of charged lepton flavour violation. We also comment on the r\^ole of charged lepton flavour violation in disentangling models of new physics. |
hep-ph/0207177 | Cheng Jian-Feng | Jian-Feng Cheng and Chao-Shang Huang | B\to \pi\phi in SM and MSSM | 10 pages, 1 figure (some errors corrected and results refreshed) | Phys.Lett. B554 (2003) 155-163 | 10.1016/S0370-2693(03)00009-1 | null | hep-ph | null | We investigate the pure penguin decays $B\to \pi\phi$ in the Standard
Model(SM) and in the Constrained Minimal Supersymmetric Standard Model (CMSSM)
using the QCD factorization approach and consider the Sudakov effects in the
twist-3 contribution. We find ${\rm Br}(B^-\to \pi^-\phi) = (1.95-5.70)\times
10^{-9}$ in SM and $(1.1-2.4)\times 10^{-8}$ in CMSSM with large $\tan\beta $
which is about one order of magnitude larger than that in SM.
| [
{
"created": "Mon, 15 Jul 2002 03:28:01 GMT",
"version": "v1"
},
{
"created": "Sat, 30 Nov 2002 02:55:00 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Cheng",
"Jian-Feng",
""
],
[
"Huang",
"Chao-Shang",
""
]
] | We investigate the pure penguin decays $B\to \pi\phi$ in the Standard Model(SM) and in the Constrained Minimal Supersymmetric Standard Model (CMSSM) using the QCD factorization approach and consider the Sudakov effects in the twist-3 contribution. We find ${\rm Br}(B^-\to \pi^-\phi) = (1.95-5.70)\times 10^{-9}$ in SM and $(1.1-2.4)\times 10^{-8}$ in CMSSM with large $\tan\beta $ which is about one order of magnitude larger than that in SM. |
2401.17729 | Francesca Capel | Francesca Capel and Ritu Aggarwal and Michiel Botje and Allen Caldwell
and Oliver Schulz and Andrii Verbytskyi | PartonDensity.jl: a novel parton density determination code | Accepted version. Code available here:
https://github.com/cescalara/PartonDensity.jl | null | 10.1103/PhysRevD.110.014024 | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | We introduce our novel Bayesian parton density determination code,
PartonDensity.jl. The motivation for this new code, the framework and its
validation are described. As we show, PartonDensity.jl provides both a flexible
environment for the determination of parton densities and a wealth of
information concerning the knowledge update provided by the analyzed data set.
| [
{
"created": "Wed, 31 Jan 2024 10:50:03 GMT",
"version": "v1"
},
{
"created": "Sat, 22 Jun 2024 11:50:44 GMT",
"version": "v2"
}
] | 2024-08-06 | [
[
"Capel",
"Francesca",
""
],
[
"Aggarwal",
"Ritu",
""
],
[
"Botje",
"Michiel",
""
],
[
"Caldwell",
"Allen",
""
],
[
"Schulz",
"Oliver",
""
],
[
"Verbytskyi",
"Andrii",
""
]
] | We introduce our novel Bayesian parton density determination code, PartonDensity.jl. The motivation for this new code, the framework and its validation are described. As we show, PartonDensity.jl provides both a flexible environment for the determination of parton densities and a wealth of information concerning the knowledge update provided by the analyzed data set. |
hep-ph/0111436 | Ubi Wichoski | Jane H. MacGibbon and Ubi F. Wichoski | High Energy Tau Neutrinos | 3 pages, 3 figures. To appear in the Proceedings of TAUP2001,
September 8-12, 2001 - Gran Sasso Laboratory, Italy | Nucl.Phys.Proc.Suppl. 110 (2002) 528-530 | 10.1016/S0920-5632(02)01556-6 | null | hep-ph | null | The intrinsic tau neutrino flux from cosmological and astrophysical sources
has usually been considered negligible in comparison to the electron and muon
neutrino fluxes. However, the inclusion of the tau neutrino component coming
from hadronic decay at the source can significantly modify the tau neutrino
spectrum expected at Earth. We report our results on the high energy tau
neutrino production and its implications for the observation of high energy
neutrino events.
| [
{
"created": "Thu, 29 Nov 2001 22:26:16 GMT",
"version": "v1"
}
] | 2015-06-25 | [
[
"MacGibbon",
"Jane H.",
""
],
[
"Wichoski",
"Ubi F.",
""
]
] | The intrinsic tau neutrino flux from cosmological and astrophysical sources has usually been considered negligible in comparison to the electron and muon neutrino fluxes. However, the inclusion of the tau neutrino component coming from hadronic decay at the source can significantly modify the tau neutrino spectrum expected at Earth. We report our results on the high energy tau neutrino production and its implications for the observation of high energy neutrino events. |
1805.01970 | Roberto Vega-Morales | Roberto Vega, Roberto Vega-Morales, Keping Xie | Light (and darkness) from a light hidden Higgs | references added, typos corrected, version to be published | null | 10.1007/JHEP06(2018)137 | UG-FT 327/18, CAFPE 197/18, SMU-HEP-18-08, FERMILAB-PUB-18-159-T | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We examine light diphoton signals from extended Higgs sectors possessing
(approximate) fermiophobia with Standard Model (SM) fermions as well as
custodial symmetry. This class of Higgs sectors can be realized in various
beyond the SM scenarios and is able to evade many experimental limits, even at
light masses, which are otherwise strongly constraining. Below the $WW$
threshold, the most robust probes of the neutral component are di and
multi-photon searches. Utilizing the dominant Drell-Yan Higgs pair production
mechanism and combining it with updated LHC diphoton data, we derive robust
upper bounds on the allowed branching ratio for masses between $45 - 160$ GeV.
Furthermore, masses $\lesssim 110$ GeV are ruled out if the coupling to photons
is dominated by $W$ boson loops. We then examine two simple ways to evade these
bounds via cancellations between different loop contributions or by introducing
decays into an invisible sector. This also opens up the possibility of future
LHC diphoton signals from a light hidden Higgs sector. As explicit
realizations, we consider the Georgi-Machacek (GM) and Supersymmetric GM (SGM)
models which contain custodial (degenerate) Higgs bosons with suppressed
couplings to SM fermions and, in the SGM model, a (neutralino) LSP. We also
breifly examine the recent $\sim 3\sigma$ CMS diphoton excess at $\sim 95$ GeV.
| [
{
"created": "Sat, 5 May 2018 00:11:46 GMT",
"version": "v1"
},
{
"created": "Wed, 20 Jun 2018 13:45:03 GMT",
"version": "v2"
}
] | 2018-08-01 | [
[
"Vega",
"Roberto",
""
],
[
"Vega-Morales",
"Roberto",
""
],
[
"Xie",
"Keping",
""
]
] | We examine light diphoton signals from extended Higgs sectors possessing (approximate) fermiophobia with Standard Model (SM) fermions as well as custodial symmetry. This class of Higgs sectors can be realized in various beyond the SM scenarios and is able to evade many experimental limits, even at light masses, which are otherwise strongly constraining. Below the $WW$ threshold, the most robust probes of the neutral component are di and multi-photon searches. Utilizing the dominant Drell-Yan Higgs pair production mechanism and combining it with updated LHC diphoton data, we derive robust upper bounds on the allowed branching ratio for masses between $45 - 160$ GeV. Furthermore, masses $\lesssim 110$ GeV are ruled out if the coupling to photons is dominated by $W$ boson loops. We then examine two simple ways to evade these bounds via cancellations between different loop contributions or by introducing decays into an invisible sector. This also opens up the possibility of future LHC diphoton signals from a light hidden Higgs sector. As explicit realizations, we consider the Georgi-Machacek (GM) and Supersymmetric GM (SGM) models which contain custodial (degenerate) Higgs bosons with suppressed couplings to SM fermions and, in the SGM model, a (neutralino) LSP. We also breifly examine the recent $\sim 3\sigma$ CMS diphoton excess at $\sim 95$ GeV. |
hep-ph/9208213 | John Collins | John Collins | Fragmentation of Transversely Polarized Quarks Probed in Transverse
Momentum Distributions | 22 pages + 4 figures (included), LaTeX. V. 2 has misprints corrected
and an appendix added, as in the published version | Nucl.Phys. B396 (1993) 161-182 | 10.1016/0550-3213(93)90262-N | null | hep-ph | null | It is shown that the azimuthal dependence of the distribution of hadrons in a
quark jet is a probe of the transverse spin of the quark initiating the jet.
This results in a new spin-dependent fragmentation function that acts at the
twist-2 level. One example of a process where it contributes is semi-inclusive
deeply inelastic scattering with a transversely polarized nucleon target but
with an {\em unpolarized} electron beam. This process is treated in detail.
Another process is the cross section for singly polarized hadron-hadron
scattering when two high $p_{\perp}$ hadrons are measured in the final state
and are close to back-to-back in azimuth. The new fragmentation function is
sensitive to the coupling of the fragmentation process to (spontaneous) chiral
symmetry breaking.
| [
{
"created": "Thu, 6 Aug 1992 21:52:09 GMT",
"version": "v1"
},
{
"created": "Fri, 10 May 2002 15:54:13 GMT",
"version": "v2"
}
] | 2009-10-22 | [
[
"Collins",
"John",
""
]
] | It is shown that the azimuthal dependence of the distribution of hadrons in a quark jet is a probe of the transverse spin of the quark initiating the jet. This results in a new spin-dependent fragmentation function that acts at the twist-2 level. One example of a process where it contributes is semi-inclusive deeply inelastic scattering with a transversely polarized nucleon target but with an {\em unpolarized} electron beam. This process is treated in detail. Another process is the cross section for singly polarized hadron-hadron scattering when two high $p_{\perp}$ hadrons are measured in the final state and are close to back-to-back in azimuth. The new fragmentation function is sensitive to the coupling of the fragmentation process to (spontaneous) chiral symmetry breaking. |
hep-ph/9811243 | Stephane Bronoff groupe | S. Bronoff, C.P. Korthals Altes | Phase diagram of 3D SU(3) gauge-adjoint Higgs system and C- violation in
hot QCD | 6 pages, 3 figures, LaTeX and revtex additional references, corrected
typos | Phys.Lett. B448 (1999) 85-92 | 10.1016/S0370-2693(99)00030-1 | null | hep-ph | null | Thermally reduced QCD leads to three dimensional SU(3) gaugefields coupled to
an adjoint scalar field $A_0$. We compute the effective potential in the
one-loop approximation and evaluate the VEV's of $TrA_0^2$ and $TrA_0^3$. In
the Higgs phase not only the former, but also the latter has a VEV. This
happens where the SU(3) gauge symmetry is broken minimally with U(2) still
unbroken. The VEV of the cubic invariant breaks charge conjugation and CP. It
is plausible that in the Higgs phase one has a transition for large enough
Higgs selfcoupling to a region where $TrA_0^3$ has no VEV and where the
gaugesymmetry is broken maximally to $U(1)\times U(1)$. For a number of colours
larger than 3 an even richer phase structure is possible.
| [
{
"created": "Wed, 4 Nov 1998 16:42:50 GMT",
"version": "v1"
},
{
"created": "Mon, 4 Jan 1999 15:35:48 GMT",
"version": "v2"
}
] | 2009-10-31 | [
[
"Bronoff",
"S.",
""
],
[
"Altes",
"C. P. Korthals",
""
]
] | Thermally reduced QCD leads to three dimensional SU(3) gaugefields coupled to an adjoint scalar field $A_0$. We compute the effective potential in the one-loop approximation and evaluate the VEV's of $TrA_0^2$ and $TrA_0^3$. In the Higgs phase not only the former, but also the latter has a VEV. This happens where the SU(3) gauge symmetry is broken minimally with U(2) still unbroken. The VEV of the cubic invariant breaks charge conjugation and CP. It is plausible that in the Higgs phase one has a transition for large enough Higgs selfcoupling to a region where $TrA_0^3$ has no VEV and where the gaugesymmetry is broken maximally to $U(1)\times U(1)$. For a number of colours larger than 3 an even richer phase structure is possible. |
2205.08470 | Tomona Kinugawa | Tomona Kinugawa and Tetsuo Hyodo | Structure of exotic hadrons by a weak-binding relation with finite-range
correction | 18 pages, 11 figures, 5 tables, published version | Phys. Rev. C 106, 015205 (2022) | 10.1103/PhysRevC.106.015205 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The composite nature of a shallow bound state is studied by using the
weak-binding relation, which connects the compositeness of the bound state with
observables. We first show that the previous weak-binding relation cannot be
applied to the system with a large effective range. To overcome this
difficulty, we introduce the finite-range correction by redefining the typical
length scale in the weak-binding relation. A method to estimate the uncertainty
of the compositeness is proposed. It is numerically demonstrated that the range
correction enlarges the applicable region of the weak-binding relation.
Finally, we apply the improved weak-binding relation to the actual hadrons,
nuclei, and atomic systems [deuteron, $X(3872)$, $D^{*}_{s0}(2317)$,
$D_{s1}(2460)$, $N\Omega$ dibaryon, $\Omega\Omega$ dibaryon,
${}^{3}_{\Lambda}{\rm H}$, and ${}^{4}{\rm He}$ dimer] to discuss their
internal structure from the compositeness. We present a reasonable estimation
of the compositeness of the deuteron by properly taking into account the
uncertainty. The results of $X(3872)$ and the $N\Omega$ dibaryon show that the
range correction is important to estimate the compositeness of physical states.
| [
{
"created": "Tue, 17 May 2022 16:22:40 GMT",
"version": "v1"
},
{
"created": "Tue, 24 May 2022 16:35:44 GMT",
"version": "v2"
},
{
"created": "Wed, 20 Jul 2022 07:12:28 GMT",
"version": "v3"
}
] | 2022-07-21 | [
[
"Kinugawa",
"Tomona",
""
],
[
"Hyodo",
"Tetsuo",
""
]
] | The composite nature of a shallow bound state is studied by using the weak-binding relation, which connects the compositeness of the bound state with observables. We first show that the previous weak-binding relation cannot be applied to the system with a large effective range. To overcome this difficulty, we introduce the finite-range correction by redefining the typical length scale in the weak-binding relation. A method to estimate the uncertainty of the compositeness is proposed. It is numerically demonstrated that the range correction enlarges the applicable region of the weak-binding relation. Finally, we apply the improved weak-binding relation to the actual hadrons, nuclei, and atomic systems [deuteron, $X(3872)$, $D^{*}_{s0}(2317)$, $D_{s1}(2460)$, $N\Omega$ dibaryon, $\Omega\Omega$ dibaryon, ${}^{3}_{\Lambda}{\rm H}$, and ${}^{4}{\rm He}$ dimer] to discuss their internal structure from the compositeness. We present a reasonable estimation of the compositeness of the deuteron by properly taking into account the uncertainty. The results of $X(3872)$ and the $N\Omega$ dibaryon show that the range correction is important to estimate the compositeness of physical states. |
hep-ph/9709252 | Helmut Eberl | A. Bartl, H. Eberl, T. Gajdosik, S. Kraml, W. Majerotto, W. Porod, and
A. Sopczak | Production and Decay of Stops and Sbottoms, and Determination of SUSY
Parameters | 7 pages, LaTeX, 5 figures, uses epsfig, contribution to the
"ECFA/DESY Study on Physics and Detectors for the Linear Collider", DESY
97-123E, ed. R. Settles | null | null | UWThPh-1997-29, HEPHY-PUB 673/97, DESY 97-169 | hep-ph | null | We present numerical predictions for the decay branching ratios of the
heavier stop and sbottom mass eigenstates. We estimate the precision to be
expected for the determination of the underlying supersymmetry parameters of
the stop and sbottom systems.
| [
{
"created": "Fri, 5 Sep 1997 08:57:41 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Bartl",
"A.",
""
],
[
"Eberl",
"H.",
""
],
[
"Gajdosik",
"T.",
""
],
[
"Kraml",
"S.",
""
],
[
"Majerotto",
"W.",
""
],
[
"Porod",
"W.",
""
],
[
"Sopczak",
"A.",
""
]
] | We present numerical predictions for the decay branching ratios of the heavier stop and sbottom mass eigenstates. We estimate the precision to be expected for the determination of the underlying supersymmetry parameters of the stop and sbottom systems. |
hep-ph/0206071 | Servant | Geraldine Servant and Tim M.P. Tait | Is the Lightest Kaluza-Klein Particle a Viable Dark Matter Candidate? | 31 pages, 12 figures; v2: A couple of references added, a few minor
clarifications (on KK parity and on the 6d case) | Nucl.Phys.B650:391-419,2003 | 10.1016/S0550-3213(02)01012-X | ANL-HEP-PR-02-032, EFI-02-74 | hep-ph astro-ph hep-th | null | In models with universal extra dimensions (i.e. in which all Standard Model
fields, including fermions, propagate into compact extra dimensions) momentum
conservation in the extra dimensions leads to the conservation of Kaluza--Klein
(KK) number at each vertex. KK number is violated by loop effects because of
the orbifold imposed to reproduce the chiral Standard Model with zero modes,
however, a KK parity remains at any order in perturbation theory which leads to
the existence of a stable lightest KK particle (LKP). In addition, the
degeneracy in the KK spectrum is lifted by radiative corrections so that all
other KK particles eventually decay into the LKP. We investigate cases where
the Standard Model lives in five or six dimensions with compactification radius
of TeV$^{-1}$ size and the LKP is the first massive state in the KK tower of
either the photon or the neutrino. We derive the relic density of the LKP under
a variety of assumptions about the spectrum of first tier KK modes. We find
that both the KK photon and the KK neutrino, with masses at the TeV scale, may
have appropriate annihilation cross sections to account for the dark matter,
$\Omega_M \sim 0.3$.
| [
{
"created": "Thu, 6 Jun 2002 16:59:25 GMT",
"version": "v1"
},
{
"created": "Mon, 23 Sep 2002 23:12:10 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Servant",
"Geraldine",
""
],
[
"Tait",
"Tim M. P.",
""
]
] | In models with universal extra dimensions (i.e. in which all Standard Model fields, including fermions, propagate into compact extra dimensions) momentum conservation in the extra dimensions leads to the conservation of Kaluza--Klein (KK) number at each vertex. KK number is violated by loop effects because of the orbifold imposed to reproduce the chiral Standard Model with zero modes, however, a KK parity remains at any order in perturbation theory which leads to the existence of a stable lightest KK particle (LKP). In addition, the degeneracy in the KK spectrum is lifted by radiative corrections so that all other KK particles eventually decay into the LKP. We investigate cases where the Standard Model lives in five or six dimensions with compactification radius of TeV$^{-1}$ size and the LKP is the first massive state in the KK tower of either the photon or the neutrino. We derive the relic density of the LKP under a variety of assumptions about the spectrum of first tier KK modes. We find that both the KK photon and the KK neutrino, with masses at the TeV scale, may have appropriate annihilation cross sections to account for the dark matter, $\Omega_M \sim 0.3$. |
1605.06029 | Dr. Rukmani Mohanta | Sruthilaya M., R. Mohanta | Non-zero $\theta_{13}$ and leptonic CP phase with $A_4$ Symmetry | 17 pages, 4 figures, typos corrected | Eur. Phys. C 77:140 (2017) | 10.1140/epjc/s10052-017-4706-z | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider a model based on $A_4$ symmetry to explain the phenomenon of
neutrino mixing. The spontaneous symmetry breaking of $A_4$ symmetry leads to a
co-bimaximal mixing matrix at leading order. We consider the effect of higher
order corrections in neutrino sector and find that the mixing angles thus
obtained, come well within the $3\sigma$ ranges of their experimental values.
We study the implications of this formalism on the other phenomenological
observables, such as CP violating phase, Jarlskog invariant and the effective
Majorana mass $|M_{ee}|$. We also obtain the branching ratio of the lepton
flavour violating decay $\mu\rightarrow e \gamma$ in the context of this model
and find that it can be less than its present experimental upper bound.
| [
{
"created": "Thu, 19 May 2016 16:15:44 GMT",
"version": "v1"
},
{
"created": "Mon, 20 Feb 2017 12:57:14 GMT",
"version": "v2"
},
{
"created": "Mon, 6 Mar 2017 16:07:14 GMT",
"version": "v3"
}
] | 2017-04-05 | [
[
"M.",
"Sruthilaya",
""
],
[
"Mohanta",
"R.",
""
]
] | We consider a model based on $A_4$ symmetry to explain the phenomenon of neutrino mixing. The spontaneous symmetry breaking of $A_4$ symmetry leads to a co-bimaximal mixing matrix at leading order. We consider the effect of higher order corrections in neutrino sector and find that the mixing angles thus obtained, come well within the $3\sigma$ ranges of their experimental values. We study the implications of this formalism on the other phenomenological observables, such as CP violating phase, Jarlskog invariant and the effective Majorana mass $|M_{ee}|$. We also obtain the branching ratio of the lepton flavour violating decay $\mu\rightarrow e \gamma$ in the context of this model and find that it can be less than its present experimental upper bound. |
hep-ph/9612207 | Arcadi Santamaria | D. Comelli, J. Bernabeu, A. Pich and A. Santamaria | Hard $m_t$ Corrections as a Probe of the Symmetry Breaking Sector | LaTex, 8 pages, 1 postscript figure included | Phys.Rev.Lett. 78 (1997) 2902-2905 | 10.1103/PhysRevLett.78.2902 | FTUV/96-85 | hep-ph | null | Non-decoupling effects related to a large $m_t$ affecting non-oblique
radiative corrections in vertices ($Z\bar{b}b$) and boxes ($B$-$\bar{B}$ mixing
and $\epsilon_K$) are very sensitive to the particular mechanism of spontaneous
symmetry breaking. We analyze these corrections in the framework of a chiral
electroweak standard model and find that there is only one operator in the
effective lagrangian which modifies the longitudinal part of the $W^+$ boson
without touching the oblique corrections. The inclusion of this operator
affects the $Z\bar{b}b$ vertex, the $B$-$\bar{B}$ mixing and the CP-violating
parameter $\epsilon_K$, generating interesting correlations among the hard
$m_t^4 \log m_t^2$ corrections to these observables, for example, the maximum
vertex $Z b\bar{b}$ correction allowed by low energy physics is about one
percent.
| [
{
"created": "Fri, 29 Nov 1996 15:06:02 GMT",
"version": "v1"
}
] | 2016-09-06 | [
[
"Comelli",
"D.",
""
],
[
"Bernabeu",
"J.",
""
],
[
"Pich",
"A.",
""
],
[
"Santamaria",
"A.",
""
]
] | Non-decoupling effects related to a large $m_t$ affecting non-oblique radiative corrections in vertices ($Z\bar{b}b$) and boxes ($B$-$\bar{B}$ mixing and $\epsilon_K$) are very sensitive to the particular mechanism of spontaneous symmetry breaking. We analyze these corrections in the framework of a chiral electroweak standard model and find that there is only one operator in the effective lagrangian which modifies the longitudinal part of the $W^+$ boson without touching the oblique corrections. The inclusion of this operator affects the $Z\bar{b}b$ vertex, the $B$-$\bar{B}$ mixing and the CP-violating parameter $\epsilon_K$, generating interesting correlations among the hard $m_t^4 \log m_t^2$ corrections to these observables, for example, the maximum vertex $Z b\bar{b}$ correction allowed by low energy physics is about one percent. |
hep-ph/9906542 | Daniel J. H. Chung | Daniel J. H. Chung and Katherine Freese | Cosmological Challenges in Theories with Extra Dimensions and Remarks on
the Horizon Problem | 15 page REVTeX file; to appear in Phys. Rev. D; clarified the
statement of being able to obtain any power dependence of the Hubble
expansion rate on the energy density; added references | Phys. Rev. D 61, 023511 (1999) | 10.1103/PhysRevD.61.023511 | null | hep-ph astro-ph hep-th | null | We consider the cosmology that results if our observable universe is a
3-brane in a higher dimensional universe. In particular, we focus on the case
where our 3-brane is located at the $Z_2$ symmetry fixed plane of a $Z_2$
symmetric five-dimensional spacetime, as in the Ho\v{r}ava-Witten model
compactified on a Calabi-Yau manifold. As our first result, we find that there
can be substantial modifications to the standard Friedmann-Robertson-Walker
(FRW) cosmology; as a consequence, a large class of such models is
observationally inconsistent. In particular, any relationship between the
Hubble constant and the energy density on our brane is possible, including (but
not only) FRW. Generically, due to the existence of the bulk and the boundary
conditions on the orbifold fixed plane, the relationship is not FRW, and hence
cosmological constraints coming from big bang nucleosynthesis, structure
formation, and the age of the universe difficult to satisfy. We do wish to
point out, however, that some specific choices for the bulk stress-energy
tensor components do reproduce normal FRW cosmology on our brane, and we have
constructed an explicit example. As our second result, for a broad class of
models, we find a somewhat surprising fact: the stabilization of the radius of
the extra dimension and hence the four dimensional Planck mass requires
unrealistic fine-tuning of the equation of state on our 3-brane. In the last
third of the paper, we make remarks about causality and the horizon problem
that apply to {\it any} theory in which the volume of the extra dimension
determines the four-dimensional gravitational coupling. We point out that some
of the assumptions that lead to the usual inflationary requirements are
modified.
| [
{
"created": "Tue, 29 Jun 1999 23:59:28 GMT",
"version": "v1"
},
{
"created": "Tue, 2 Nov 1999 23:58:03 GMT",
"version": "v2"
}
] | 2016-08-25 | [
[
"Chung",
"Daniel J. H.",
""
],
[
"Freese",
"Katherine",
""
]
] | We consider the cosmology that results if our observable universe is a 3-brane in a higher dimensional universe. In particular, we focus on the case where our 3-brane is located at the $Z_2$ symmetry fixed plane of a $Z_2$ symmetric five-dimensional spacetime, as in the Ho\v{r}ava-Witten model compactified on a Calabi-Yau manifold. As our first result, we find that there can be substantial modifications to the standard Friedmann-Robertson-Walker (FRW) cosmology; as a consequence, a large class of such models is observationally inconsistent. In particular, any relationship between the Hubble constant and the energy density on our brane is possible, including (but not only) FRW. Generically, due to the existence of the bulk and the boundary conditions on the orbifold fixed plane, the relationship is not FRW, and hence cosmological constraints coming from big bang nucleosynthesis, structure formation, and the age of the universe difficult to satisfy. We do wish to point out, however, that some specific choices for the bulk stress-energy tensor components do reproduce normal FRW cosmology on our brane, and we have constructed an explicit example. As our second result, for a broad class of models, we find a somewhat surprising fact: the stabilization of the radius of the extra dimension and hence the four dimensional Planck mass requires unrealistic fine-tuning of the equation of state on our 3-brane. In the last third of the paper, we make remarks about causality and the horizon problem that apply to {\it any} theory in which the volume of the extra dimension determines the four-dimensional gravitational coupling. We point out that some of the assumptions that lead to the usual inflationary requirements are modified. |
hep-ph/0411349 | Ricardo Gonzalez Felipe | R. Gonzalez Felipe | Natural braneworld inflation and baryogenesis | 12 pages, 2 figures; comments added, references updated. Final
version to appear in Phys. Lett. B | Phys.Lett. B618 (2005) 7-13 | 10.1016/j.physletb.2005.05.055 | null | hep-ph | null | In natural inflation models, the inflaton is a pseudo Nambu-Goldstone boson
and the flatness of the potential is protected by shift symmetries. In this
framework, a successful inflation requires the global symmetry to be
spontaneously broken at a scale close to the Planck mass. Such a high value of
the spontaneous breaking scale may not be legitimate in an effective field
theory. On the other hand, if natural inflation occurs during the
nonconventional high-energy era in braneworld cosmology, the conditions for the
inflaton slow rolling can be eased and the spontaneous breaking scale can be
lowered to values below the Planck scale. We examine the observational
constraints on this scenario and study the possibility that the baryon
asymmetry of the universe is generated by the decay of the pseudo
Nambu-Goldstone boson during the reheating era.
| [
{
"created": "Fri, 26 Nov 2004 20:05:27 GMT",
"version": "v1"
},
{
"created": "Sun, 29 May 2005 20:44:27 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Felipe",
"R. Gonzalez",
""
]
] | In natural inflation models, the inflaton is a pseudo Nambu-Goldstone boson and the flatness of the potential is protected by shift symmetries. In this framework, a successful inflation requires the global symmetry to be spontaneously broken at a scale close to the Planck mass. Such a high value of the spontaneous breaking scale may not be legitimate in an effective field theory. On the other hand, if natural inflation occurs during the nonconventional high-energy era in braneworld cosmology, the conditions for the inflaton slow rolling can be eased and the spontaneous breaking scale can be lowered to values below the Planck scale. We examine the observational constraints on this scenario and study the possibility that the baryon asymmetry of the universe is generated by the decay of the pseudo Nambu-Goldstone boson during the reheating era. |
2209.13888 | Shivam Verma | Shivam Verma, Sanjoy Biswas, Anirban Chatterjee, Joy Ganguly | Exploring maverick top partner decays at the LHC | 31 pages, 18 figures, 12 tables. Additional background contributions
has been added and Fig. 16 has been updated with mass dependent bound.
Matches with version published in Phys. Rev. D | Phys. Rev. D 107, 115024 (2023) | 10.1103/PhysRevD.107.115024 | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | In this work, we have considered an extension of the standard model (SM) with
a $SU(2)_L$ singlet vectorlike quark (VLQ) with electric charge $Q=+2/3$. The
model also contains an additional local $U(1)_d$ symmetry group and the
corresponding gauge boson is the dark photon. The VLQ is charged while all the
SM particles are neutral under the new $U(1)_d$ gauge group. Even though in
this model the VLQ possesses many properties qualitatively similar to that of
the traditional top partner ($T_p$), there are some compelling differences as
well. In particular, its branching ratio to the traditional modes ($T_p \to bW,
tZ, th$) are suppressed which in turn helps to evade many of the existing
bound, mainly coming from the LHC experiments. In an earlier work, such a VLQ
is referred to as ``maverick top partner". It has been shown that the top
partner in this model predominantly decays to a top quark and a dark
photon/dark higgs pair ($T_p \to t\gamma_d ,~th_d$) over a large region of the
parameter space. The dark photon can be made invisible and consequently, it
gives rise to the missing transverse energy ($\not\!\!{E} _{T}$) signature at
the LHC detector. We have mainly focused on the LHC signatures and future
prospects of such top partners. In particular, we have studied the
$t\bar{t}+\not\!\!{E}_{T}$ and $t+\not\!\!{E}_{T}$ signatures in the context of
the LHC via pair and single productions of the top partner, respectively at 13
and 14 TeV LHC center of mass energies assuming that the dark photon either
decays into an invisible mode or it is invisible at the length scale of the
detector. We have shown that one can exclude $\sin\theta_L \sim 0.025$ (0.05)
for $m_{_{T_p}} \leq $ 2.0 (2.6) TeV at $\sqrt{s}=14$ TeV with an integrated
luminosity of 3 ab$^{-1}$ using the single top partner production channel.
| [
{
"created": "Wed, 28 Sep 2022 07:39:40 GMT",
"version": "v1"
},
{
"created": "Tue, 18 Oct 2022 15:43:59 GMT",
"version": "v2"
},
{
"created": "Tue, 20 Jun 2023 16:20:23 GMT",
"version": "v3"
}
] | 2023-06-21 | [
[
"Verma",
"Shivam",
""
],
[
"Biswas",
"Sanjoy",
""
],
[
"Chatterjee",
"Anirban",
""
],
[
"Ganguly",
"Joy",
""
]
] | In this work, we have considered an extension of the standard model (SM) with a $SU(2)_L$ singlet vectorlike quark (VLQ) with electric charge $Q=+2/3$. The model also contains an additional local $U(1)_d$ symmetry group and the corresponding gauge boson is the dark photon. The VLQ is charged while all the SM particles are neutral under the new $U(1)_d$ gauge group. Even though in this model the VLQ possesses many properties qualitatively similar to that of the traditional top partner ($T_p$), there are some compelling differences as well. In particular, its branching ratio to the traditional modes ($T_p \to bW, tZ, th$) are suppressed which in turn helps to evade many of the existing bound, mainly coming from the LHC experiments. In an earlier work, such a VLQ is referred to as ``maverick top partner". It has been shown that the top partner in this model predominantly decays to a top quark and a dark photon/dark higgs pair ($T_p \to t\gamma_d ,~th_d$) over a large region of the parameter space. The dark photon can be made invisible and consequently, it gives rise to the missing transverse energy ($\not\!\!{E} _{T}$) signature at the LHC detector. We have mainly focused on the LHC signatures and future prospects of such top partners. In particular, we have studied the $t\bar{t}+\not\!\!{E}_{T}$ and $t+\not\!\!{E}_{T}$ signatures in the context of the LHC via pair and single productions of the top partner, respectively at 13 and 14 TeV LHC center of mass energies assuming that the dark photon either decays into an invisible mode or it is invisible at the length scale of the detector. We have shown that one can exclude $\sin\theta_L \sim 0.025$ (0.05) for $m_{_{T_p}} \leq $ 2.0 (2.6) TeV at $\sqrt{s}=14$ TeV with an integrated luminosity of 3 ab$^{-1}$ using the single top partner production channel. |
hep-ph/9707347 | Antonio Pich | F. Guerrero and A. Pich | Effective Field Theory Description of the Pion Form Factor | 10 pages, latex, 2 Postscript figures | Phys.Lett.B412:382-388,1997 | 10.1016/S0370-2693(97)01070-8 | FTUV/97-42, IFIC/97-42 | hep-ph | null | Using our present knowledge on effective hadronic theories, short-distance
QCD information, the $1/N_C$ expansion, analyticity and unitarity, we derive an
expression for the pion form factor, in terms of $m_\pi, m_K, M_\rho$ and
$f_\pi$. This parameter-free prediction provides a surprisingly good
description of the experimental data up to energies of the order of 1 GeV.
| [
{
"created": "Mon, 14 Jul 1997 16:52:25 GMT",
"version": "v1"
}
] | 2011-05-05 | [
[
"Guerrero",
"F.",
""
],
[
"Pich",
"A.",
""
]
] | Using our present knowledge on effective hadronic theories, short-distance QCD information, the $1/N_C$ expansion, analyticity and unitarity, we derive an expression for the pion form factor, in terms of $m_\pi, m_K, M_\rho$ and $f_\pi$. This parameter-free prediction provides a surprisingly good description of the experimental data up to energies of the order of 1 GeV. |
2011.11423 | Elena V. Arbuzova | E.V. Arbuzova | Superheavy dark matter in $R^2$-cosmology | 12 pages, 1 figure, submitted to IJMPD. arXiv admin note: text
overlap with arXiv:1811.05399 | null | 10.1142/S0218271821400022 | null | hep-ph astro-ph.CO | http://creativecommons.org/licenses/by/4.0/ | The conventional Friedmann cosmology is known to be in tension with the
existence of stable particles having interaction strength typical for
supersymmetry and heavier than several TeV. A possible way to save life of such
particles may be a modification of the standard cosmological expansion law in
such a way that the density of these heavy relics would be significantly
reduced. We study particle creation in the Starobinsky inflationary model for
different decay channels of the scalaron. It is shown that in the process of
thermalization superheavy stable particles with the coupling strength typical
for the GUT SUSY could be created with the density equal to the observed
density of dark matter.
| [
{
"created": "Fri, 20 Nov 2020 12:48:41 GMT",
"version": "v1"
}
] | 2022-02-16 | [
[
"Arbuzova",
"E. V.",
""
]
] | The conventional Friedmann cosmology is known to be in tension with the existence of stable particles having interaction strength typical for supersymmetry and heavier than several TeV. A possible way to save life of such particles may be a modification of the standard cosmological expansion law in such a way that the density of these heavy relics would be significantly reduced. We study particle creation in the Starobinsky inflationary model for different decay channels of the scalaron. It is shown that in the process of thermalization superheavy stable particles with the coupling strength typical for the GUT SUSY could be created with the density equal to the observed density of dark matter. |
hep-ph/0303128 | Joao Pacheco B. C. de Melo | E.F. Suisso (Dep. de Fisica, Instituto Tecnologico da Aeronautica
Centro Tecnico Aeroespacial, Sao Jose dos Campos, SP, Brazil), J. P. B. C. de
Melo (Instituto de Fisica Teorica, Universidade Estadual Paulista, Sao Paulo,
SP, Brazil) and T. Frederico (Dep. de Fisica, ITA, Centro Tecnico
Aeroespacial, Sao Jose dos Campos, SP, Brazil) | Ground State Masses and Biding Energies of the Nucleon, Hyperon and
Heavy Baryons in a Light-Front Model | 13 pages, include 4 eps figures, use latex, revtex | Braz.J.Phys. 33 (2003) 306-310 | 10.1590/S0103-97332003000200028 | null | hep-ph nucl-th | null | The ground state masses and binding energies of the nucleon,
$\Lambda^0$, $\Lambda^+_c$, $\Lambda^0_b$ are studied within a constituent
quark QCD-inspired light-front model. The light-front Faddeev equations for the
$Qqq$ composite spin 1/2 baryons, are derived and solved numerically. The
experimental data for the masses are qualitatively described by a flavor
independent effective interaction.
| [
{
"created": "Fri, 14 Mar 2003 20:58:54 GMT",
"version": "v1"
}
] | 2015-06-25 | [
[
"Suisso",
"E. F.",
"",
"Dep. de Fisica, Instituto Tecnologico da Aeronautica\n Centro Tecnico Aeroespacial, Sao Jose dos Campos, SP, Brazil"
],
[
"de Melo",
"J. P. B. C.",
"",
"Instituto de Fisica Teorica, Universidade Estadual Paulista, Sao Paulo,\n SP, Brazil"
],
[
... | The ground state masses and binding energies of the nucleon, $\Lambda^0$, $\Lambda^+_c$, $\Lambda^0_b$ are studied within a constituent quark QCD-inspired light-front model. The light-front Faddeev equations for the $Qqq$ composite spin 1/2 baryons, are derived and solved numerically. The experimental data for the masses are qualitatively described by a flavor independent effective interaction. |
0710.5491 | Pedro Fernando Simoes Costa | Pedro Costa, M. C. Ruivo, C. A. de Sousa | Effects of the Regularization on the Restoration of Chiral and Axial
Symmetries | 15 pages, 5 figures; PRD version | Phys.Rev.D77:096009,2008 | 10.1103/PhysRevD.77.096009 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The effects of a type of regularization for finite temperatures on the
estoration of chiral and axial symmetries are investigated within the SU(3)
Nambu-Jona-Lasinio model. The regularization consists in using an infinite
cutoff in the integrals that are convergent at finite temperature, a procedure
that allows one to take into account the effects of high momentum quarks at
high temperatures. It is found that the critical temperature for the phase
transition is closer to lattice results than the one obtained with the
conventional regularization, and the restoration of chiral and axial
symmetries, signaled by the behavior of several observables, occurs
simultaneously and at a higher temperature. The restoration of the axial
symmetry appears as a natural consequence of the full recovering of the chiral
symmetry that was dynamically broken. By using an additional ansatz that
simulates instanton suppression effects, by means of a convenient temperature
dependence of the anomaly coefficient, we found that the restoration of U(2)
symmetry is shifted to lower values, but the dominant effect at high
temperatures comes from the new regularization that enhances the decrease of
quark condensates, especially in the strange sector.
| [
{
"created": "Mon, 29 Oct 2007 17:48:26 GMT",
"version": "v1"
},
{
"created": "Tue, 17 Jun 2008 08:12:47 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Costa",
"Pedro",
""
],
[
"Ruivo",
"M. C.",
""
],
[
"de Sousa",
"C. A.",
""
]
] | The effects of a type of regularization for finite temperatures on the estoration of chiral and axial symmetries are investigated within the SU(3) Nambu-Jona-Lasinio model. The regularization consists in using an infinite cutoff in the integrals that are convergent at finite temperature, a procedure that allows one to take into account the effects of high momentum quarks at high temperatures. It is found that the critical temperature for the phase transition is closer to lattice results than the one obtained with the conventional regularization, and the restoration of chiral and axial symmetries, signaled by the behavior of several observables, occurs simultaneously and at a higher temperature. The restoration of the axial symmetry appears as a natural consequence of the full recovering of the chiral symmetry that was dynamically broken. By using an additional ansatz that simulates instanton suppression effects, by means of a convenient temperature dependence of the anomaly coefficient, we found that the restoration of U(2) symmetry is shifted to lower values, but the dominant effect at high temperatures comes from the new regularization that enhances the decrease of quark condensates, especially in the strange sector. |
hep-ph/0310202 | Jens Erler | Jens Erler | Constraining Electroweak Physics | 8 pages, 6 figures, Talk presented at the 2nd International
Conference on String Phenomenology 2003, Durham, England, July 29 - August 4,
2003 | null | null | FT2003-03 | hep-ph | null | I summarize the status of the Standard Model after the 2003 summer
conferences.
| [
{
"created": "Thu, 16 Oct 2003 23:03:13 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Erler",
"Jens",
""
]
] | I summarize the status of the Standard Model after the 2003 summer conferences. |
hep-ph/0702272 | Jan Nemchik | B.Z. Kopeliovich (Santa Maria U., Valparaiso & Dubna, JINR), J.
Nemchik (IEP SAS, Kosice), Ivan Schmidt (Santa Maria U., Valparaiso) | Color Transparency at Low Energies: Predictions for JLAB | 16 pages including 2 figures | Phys.Rev.C76:015205,2007 | 10.1103/PhysRevC.76.015205 | USM-TH-206 | hep-ph | null | The study of color transparency (CT) in elastic electroproduction of vector
mesons off nuclei encounters the problem of the onset of coherence length (CL)
effects. The problem of CT-CL separation arises especially at medium energies,
corresponding to HERMES experiment, when the coherence length is of the order
of the nuclear radius R_A. Only at asymptotic large energies, corresponding to
large CL, l_c >> R_A, the CT-CL mixing can be eliminated. On the other hand,
the net CT effects can be studied in the kinematic range accessible by the CLAS
experiment, since in this case the CL is much smaller than the nuclear radius.
Using light-cone quantum chromodynamics (QCD) dipole formalism we investigate
manifestations of CT effects in electroproduction of vector mesons. Motivated
by expected data from the CLAS experiment at JLab, we predict the A and Q^2
dependence of nuclear transparency for rho^0 mesons produced incoherently off
nuclei. We demonstrate that in the CLAS kinematical region the CL effects are
weak enough to keep the photon energy at such values as to obtain maximal
photon virtualities keeping optimal statistics of the data. This has a clear
advantage in comparison with a standard investigation of net CT effects fixing
CL.
| [
{
"created": "Tue, 27 Feb 2007 09:12:15 GMT",
"version": "v1"
},
{
"created": "Thu, 1 Mar 2007 11:50:03 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Kopeliovich",
"B. Z.",
"",
"Santa Maria U., Valparaiso & Dubna, JINR"
],
[
"Nemchik",
"J.",
"",
"IEP SAS, Kosice"
],
[
"Schmidt",
"Ivan",
"",
"Santa Maria U., Valparaiso"
]
] | The study of color transparency (CT) in elastic electroproduction of vector mesons off nuclei encounters the problem of the onset of coherence length (CL) effects. The problem of CT-CL separation arises especially at medium energies, corresponding to HERMES experiment, when the coherence length is of the order of the nuclear radius R_A. Only at asymptotic large energies, corresponding to large CL, l_c >> R_A, the CT-CL mixing can be eliminated. On the other hand, the net CT effects can be studied in the kinematic range accessible by the CLAS experiment, since in this case the CL is much smaller than the nuclear radius. Using light-cone quantum chromodynamics (QCD) dipole formalism we investigate manifestations of CT effects in electroproduction of vector mesons. Motivated by expected data from the CLAS experiment at JLab, we predict the A and Q^2 dependence of nuclear transparency for rho^0 mesons produced incoherently off nuclei. We demonstrate that in the CLAS kinematical region the CL effects are weak enough to keep the photon energy at such values as to obtain maximal photon virtualities keeping optimal statistics of the data. This has a clear advantage in comparison with a standard investigation of net CT effects fixing CL. |
1507.05176 | Xing-Gang Wu | Chao-Hsi Chang, Xian-You Wang and Xing-Gang Wu | BCVEGPY2.2: A Newly Upgraded Version for Hadronic Production of the
Meson $B_c$ and Its Excited States | 4 pages, 1 figures | Comput. Phys. Commun. 197 (2015) 335-338 | 10.1016/j.cpc.2015.07.015 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A newly upgraded version of the BCVEGPY, a generator for hadronic production
of the meson $B_c$ and its excited states, is available. In comparison with the
previous one [C.H. Chang, J.X. Wang and X.G. Wu, Comput. Phys. Commun. {\bf
175}, 624 (2006)], the new version is to apply an improved hit-and-miss
technology to generating the un-weighted events much more efficiently under
various simulation environments. The codes for production of $2S$-wave $B_c$
states are also given here.
| [
{
"created": "Sat, 18 Jul 2015 12:07:40 GMT",
"version": "v1"
}
] | 2015-09-28 | [
[
"Chang",
"Chao-Hsi",
""
],
[
"Wang",
"Xian-You",
""
],
[
"Wu",
"Xing-Gang",
""
]
] | A newly upgraded version of the BCVEGPY, a generator for hadronic production of the meson $B_c$ and its excited states, is available. In comparison with the previous one [C.H. Chang, J.X. Wang and X.G. Wu, Comput. Phys. Commun. {\bf 175}, 624 (2006)], the new version is to apply an improved hit-and-miss technology to generating the un-weighted events much more efficiently under various simulation environments. The codes for production of $2S$-wave $B_c$ states are also given here. |
2309.14939 | Gero von Gersdorff | Gero von Gersdorff | Factorization of covariant Feynman graphs for the effective action | null | null | null | null | hep-ph hep-th | http://creativecommons.org/licenses/by/4.0/ | We prove a neat factorization property of Feynman graphs in covariant
perturbation theory. The contribution of the graph to the effective action is
written as a product of a massless scalar momentum integral that only depends
on the basic graph topology, and a background-field dependent piece that
contains all the information of spin, gauge representations, masses etc. We
give a closed expression for the momentum integral in terms of four graph
polynomials whose properties we derive in some detail. Our results can also be
useful for standard (non-covariant) perturbation theory.
| [
{
"created": "Tue, 26 Sep 2023 13:52:26 GMT",
"version": "v1"
}
] | 2023-09-27 | [
[
"von Gersdorff",
"Gero",
""
]
] | We prove a neat factorization property of Feynman graphs in covariant perturbation theory. The contribution of the graph to the effective action is written as a product of a massless scalar momentum integral that only depends on the basic graph topology, and a background-field dependent piece that contains all the information of spin, gauge representations, masses etc. We give a closed expression for the momentum integral in terms of four graph polynomials whose properties we derive in some detail. Our results can also be useful for standard (non-covariant) perturbation theory. |
2105.11254 | Sergio Campos | S. D. Campos | Chiral Symmetry Restoration using the Running Coupling Constant from the
Light-Front Approach to QCD | 16 pages, 2 figures. This improved version contains corrections for
some typos as well as some development in discussions along the text | null | null | null | hep-ph hep-lat hep-th | http://creativecommons.org/licenses/by/4.0/ | In this work, the distance between a quark-antiquark pair is analyzed through
both the confinement potential as well as the hadronic total cross section.
Using the Helmholtz free energy, entropy is calculated near the minimum of the
total cross section through the confinement potential. A fitting procedure for
the proton-proton total cross section is performed, defining the fitting
parameters. Therefore, the only free parameter remaining in the model is the
mass scale $\kappa$ used to define the running coupling constant of the
light-front approach to QCD. The mass scale controls the distance $r$ between
the quark-antiquark pair and, under some conditions, it allows the occurrence
of free quarks even in the confinement regime of QCD.
| [
{
"created": "Mon, 24 May 2021 13:11:27 GMT",
"version": "v1"
},
{
"created": "Thu, 5 Aug 2021 14:42:48 GMT",
"version": "v2"
}
] | 2021-08-06 | [
[
"Campos",
"S. D.",
""
]
] | In this work, the distance between a quark-antiquark pair is analyzed through both the confinement potential as well as the hadronic total cross section. Using the Helmholtz free energy, entropy is calculated near the minimum of the total cross section through the confinement potential. A fitting procedure for the proton-proton total cross section is performed, defining the fitting parameters. Therefore, the only free parameter remaining in the model is the mass scale $\kappa$ used to define the running coupling constant of the light-front approach to QCD. The mass scale controls the distance $r$ between the quark-antiquark pair and, under some conditions, it allows the occurrence of free quarks even in the confinement regime of QCD. |
2111.05153 | Luca Silvestrini | M. Ciuchini, E. Franco, V. Lubicz, G. Martinelli, L. Silvestrini, C.
Tarantino | Power corrections to the CP-violation parameter $\varepsilon_K$ | 23 pages, 2 figures. v2: added references and CKM parameter values.
v3: matches published version | null | 10.1007/JHEP02(2022)181 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the calculation of the short-distance power corrections to the
CP-violation parameter $\varepsilon_K$ coming from dimension-8 operators in the
$\Delta S=2$ effective Hamiltonian. A first estimate of this contribution,
obtained for large-$N_c$ and in the chiral limit, was provided in ref.
[arXiv:hep-ph/0406094]. Here we evaluate and include the
$\mathcal{O}(m_K^2/m_c^2)$ and $\mathcal{O}(\Lambda_{QCD}^2/m_c^2)$
contributions that, a priori, could induce $\mathcal{O}(1)$ corrections to
previous estimates, as $m_K$ is numerically of order $\Lambda_{QCD}$. Our
computation shows that there are several dimension-8 operators besides the one
considered before. Their effect on $\varepsilon_K$, however, accidentally
cancels out to a large extent, leaving the final correction at the level of 1%.
| [
{
"created": "Tue, 9 Nov 2021 13:58:04 GMT",
"version": "v1"
},
{
"created": "Thu, 9 Dec 2021 10:29:55 GMT",
"version": "v2"
},
{
"created": "Mon, 14 Feb 2022 13:42:33 GMT",
"version": "v3"
}
] | 2022-03-09 | [
[
"Ciuchini",
"M.",
""
],
[
"Franco",
"E.",
""
],
[
"Lubicz",
"V.",
""
],
[
"Martinelli",
"G.",
""
],
[
"Silvestrini",
"L.",
""
],
[
"Tarantino",
"C.",
""
]
] | We present the calculation of the short-distance power corrections to the CP-violation parameter $\varepsilon_K$ coming from dimension-8 operators in the $\Delta S=2$ effective Hamiltonian. A first estimate of this contribution, obtained for large-$N_c$ and in the chiral limit, was provided in ref. [arXiv:hep-ph/0406094]. Here we evaluate and include the $\mathcal{O}(m_K^2/m_c^2)$ and $\mathcal{O}(\Lambda_{QCD}^2/m_c^2)$ contributions that, a priori, could induce $\mathcal{O}(1)$ corrections to previous estimates, as $m_K$ is numerically of order $\Lambda_{QCD}$. Our computation shows that there are several dimension-8 operators besides the one considered before. Their effect on $\varepsilon_K$, however, accidentally cancels out to a large extent, leaving the final correction at the level of 1%. |
hep-ph/9812532 | null | S. A. Kulagin | Nuclear Shadowing in Neutrino Deep Inelastic Scattering | 8 pages, 3 figures, Talk given at XIV International Seminar on High
Energy Physics Problems `Relativistic Nuclear Physics And Quantum
Chromodynamics', Dubna, August 17-22, 1998 | null | null | null | hep-ph | null | We discuss effect of nuclear shadowing in neutrino deep-inelastic scattering
in terms of non perturbative parton model. We found that for small Bjorken $x$
and large $Q^2$ the structure function $F_3$ is shadowed in nuclei about two
times as stronger as $F_2$. The underlying reason and phenomenological aspects
of this observation are discussed.
| [
{
"created": "Thu, 31 Dec 1998 11:47:05 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Kulagin",
"S. A.",
""
]
] | We discuss effect of nuclear shadowing in neutrino deep-inelastic scattering in terms of non perturbative parton model. We found that for small Bjorken $x$ and large $Q^2$ the structure function $F_3$ is shadowed in nuclei about two times as stronger as $F_2$. The underlying reason and phenomenological aspects of this observation are discussed. |
hep-ph/0304137 | Manoranjan Guchait | R. M. Godbole, M. Guchait, K. Mazumdar, S. Moretti, D. P. Roy | Search for `invisible' Higgs signals at LHC via Associated Production
with Gauge Bosons | 12 pages, 2 Figures, LateX; minor revision; few references added;
version to appear in PLB | Phys.Lett. B571 (2003) 184-192 | 10.1016/j.physletb.2003.06.066 | DESY-03-042, SHEP-03-06, TIFR-EHEP-03-03, TIFR-TH-03-08 | hep-ph | null | A light Higgs boson with substantial branching ratio into invisible channels
can occur in a variety of models with: light neutralinos, spontaneously broken
lepton number, radiatively generated neutrino masses, additional singlet
scalar(s) and/or right handed neutrinos in the extra dimensions of TeV scale
gravity. We study the observability of the WH and ZH modes at LHC with H
decaying invisibly, by carrying out a detailed simulation with two event
generators HERWIG and PYTHIA and realistic detector simulations (GETJET and
CMSJET). We find that the signal with `single lepton plus missing $E_T$'
resulting from WH production suffers from a very large background due to the
(off-shell) $W^{*}$ production via the Drell-Yan process. In contrast, the ZH
mode provides a clean signal in the `dilepton plus missing $E_T$' channel. By
exploiting this second signature, we show that invisible branching ratios of
Higgs bosons, ${BR}_{inv}$, larger than $\sim 0.42(0.70)$ can be probed at
5$\sigma$ level for $M_H = 120$(160) GeV respectively, assuming an accumulated
luminosity of L=100 fb$^{-1}$.
| [
{
"created": "Tue, 15 Apr 2003 06:36:32 GMT",
"version": "v1"
},
{
"created": "Tue, 15 Jul 2003 09:23:39 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Godbole",
"R. M.",
""
],
[
"Guchait",
"M.",
""
],
[
"Mazumdar",
"K.",
""
],
[
"Moretti",
"S.",
""
],
[
"Roy",
"D. P.",
""
]
] | A light Higgs boson with substantial branching ratio into invisible channels can occur in a variety of models with: light neutralinos, spontaneously broken lepton number, radiatively generated neutrino masses, additional singlet scalar(s) and/or right handed neutrinos in the extra dimensions of TeV scale gravity. We study the observability of the WH and ZH modes at LHC with H decaying invisibly, by carrying out a detailed simulation with two event generators HERWIG and PYTHIA and realistic detector simulations (GETJET and CMSJET). We find that the signal with `single lepton plus missing $E_T$' resulting from WH production suffers from a very large background due to the (off-shell) $W^{*}$ production via the Drell-Yan process. In contrast, the ZH mode provides a clean signal in the `dilepton plus missing $E_T$' channel. By exploiting this second signature, we show that invisible branching ratios of Higgs bosons, ${BR}_{inv}$, larger than $\sim 0.42(0.70)$ can be probed at 5$\sigma$ level for $M_H = 120$(160) GeV respectively, assuming an accumulated luminosity of L=100 fb$^{-1}$. |
hep-ph/0412217 | Olga Voskresenskaya | A.N. Sissakian, A.V. Tarasov, H.T. Torosyan and O.O. Voskresenskaya | $e^+e^-$ pair production in relativistic ions collision and its
correspondence to electron-ion scattering | 5 pages, no figures, LaTEX; submitted to Physics Letters B | null | null | null | hep-ph | null | It is shown that the amplitudes of electron-ion scattering and $e^+e^-$ pair
production in the Coulomb field of two colliding ions are sxpressed in the
terms of electron scattering amplitudes in the fields of the individual ions
via the Watson expansion. We have obtained the compact expressions for these
amplitudes valid in the high energy limit and discuss the crossing symmetry
relations among the considered processes.
| [
{
"created": "Wed, 15 Dec 2004 18:30:21 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Sissakian",
"A. N.",
""
],
[
"Tarasov",
"A. V.",
""
],
[
"Torosyan",
"H. T.",
""
],
[
"Voskresenskaya",
"O. O.",
""
]
] | It is shown that the amplitudes of electron-ion scattering and $e^+e^-$ pair production in the Coulomb field of two colliding ions are sxpressed in the terms of electron scattering amplitudes in the fields of the individual ions via the Watson expansion. We have obtained the compact expressions for these amplitudes valid in the high energy limit and discuss the crossing symmetry relations among the considered processes. |
hep-ph/9707490 | null | Yu.S.Kalashnikova, A.V.Nefediev (ITEP) | Potential regime for heavy quarks dynamics and Lorentz nature of
confinement | 10 pages, LaTeX2e, no figures | Phys.Lett. B414 (1997) 149-156 | 10.1016/S0370-2693(97)01157-X | ITEP-28-97 | hep-ph | null | Propagation of the heavy quark in the field of a static antiquark source is
studied in the framework of effective Dirac equation. The model of QCD vacuum
is described by bilocal gluonic correlators. In the heavy quark limit the
effective interaction is reduced to the potential one with 5/6 Lorentz scalar
and 1/6 Lorentz vector linear confinement, while spin-orbit term is in
agreement with Eichten-Feinberg-Gromes results. New spin-independent
corrections to the leading confining regime are identified, which arise due to
the nonlocality of the interaction in time direction and quark Zitterbewegung.
| [
{
"created": "Mon, 28 Jul 1997 14:41:21 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Kalashnikova",
"Yu. S.",
"",
"ITEP"
],
[
"Nefediev",
"A. V.",
"",
"ITEP"
]
] | Propagation of the heavy quark in the field of a static antiquark source is studied in the framework of effective Dirac equation. The model of QCD vacuum is described by bilocal gluonic correlators. In the heavy quark limit the effective interaction is reduced to the potential one with 5/6 Lorentz scalar and 1/6 Lorentz vector linear confinement, while spin-orbit term is in agreement with Eichten-Feinberg-Gromes results. New spin-independent corrections to the leading confining regime are identified, which arise due to the nonlocality of the interaction in time direction and quark Zitterbewegung. |
hep-ph/0108155 | Yue-Liang Wu | Yue-Liang Wu (ITP, Beijing) | Consistent Prediction for Direct CP Violation and \Delta I = 1/2 Rule | Plenary Talk presented at the International Conference on Flavor
Physics (ICFP2001), May 31-June 6, 2001 at Zhang-Jia-Jie | null | 10.1142/9789812777379_0019 | null | hep-ph | null | The theoretical status of direct CP violation $\epsilon'/\epsilon$ is briefly
reviewed. Special attention is paid to the recent new consistent predictions
for both the ratio $\epsilon'/\epsilon$ and the $\Delta I = 1/2$ rule within
the standard model. In particular, two matching conditions resulting from the
matching between the QCD and chiral perturbation theory(ChPT), and also some
algebraic relations of chiral operators are found to be very useful. It is of
interest that the new predictions are no longer sensitive to the strange quark
mass, and are also renormalization scale and scheme independent in the leading
QCD and chiral loop approximation with large $N_c$ approach. The new prediction
for the direct CP violation with the value $\epsilon'/\epsilon= (20 \pm 4)
\times 10^{-4} [Im\lambda_t /1.2\times 10^{-4}]$ is consistent with the most
recent experimental results reported by the NA48 and KTeV groups.
| [
{
"created": "Mon, 20 Aug 2001 03:02:14 GMT",
"version": "v1"
}
] | 2017-08-23 | [
[
"Wu",
"Yue-Liang",
"",
"ITP, Beijing"
]
] | The theoretical status of direct CP violation $\epsilon'/\epsilon$ is briefly reviewed. Special attention is paid to the recent new consistent predictions for both the ratio $\epsilon'/\epsilon$ and the $\Delta I = 1/2$ rule within the standard model. In particular, two matching conditions resulting from the matching between the QCD and chiral perturbation theory(ChPT), and also some algebraic relations of chiral operators are found to be very useful. It is of interest that the new predictions are no longer sensitive to the strange quark mass, and are also renormalization scale and scheme independent in the leading QCD and chiral loop approximation with large $N_c$ approach. The new prediction for the direct CP violation with the value $\epsilon'/\epsilon= (20 \pm 4) \times 10^{-4} [Im\lambda_t /1.2\times 10^{-4}]$ is consistent with the most recent experimental results reported by the NA48 and KTeV groups. |
2309.02599 | Adrian Thompson | A.A. Aguilar-Arevalo, S. Biedron, J. Boissevain, M. Borrego, L. Bugel,
M. Chavez-Estrada, J.M. Conrad, R.L. Cooper, A. Diaz, J.R. Distel, J.C.
D'Olivo, E. Dunton, B. Dutta, D. Fields, J.R. Gochanour, M. Gold, E.
Guardincerri, E.C. Huang, N. Kamp, D. Kim, K. Knickerbocker, W.C. Louis,
J.T.M. Lyles, R. Mahapatra, S. Maludze, J. Mirabal, D. Newmark, P.
deNiverville, V. Pandey, D. Poulson, H. Ray, E. Renner, T.J. Schaub, A.
Schneider, M.H. Shaevitz, D. Smith, W. Sondheim, A.M. Szelc, C. Taylor, A.
Thompson, W.H. Thompson, M. Tripathi, R.T. Thornton, R. Van Berg, R.G. Van de
Water | Testing Meson Portal Dark Sector Solutions to the MiniBooNE Anomaly at
CCM | Added sensitivity forecast for a future MicroBooNE search (with more
exposure and increased signal efficiency) for the single-photon, zero nucleon
final state | Phys.Rev.D 109 (2024) 9, 095017 | null | LA-UR-23-29529 | hep-ph hep-ex | http://creativecommons.org/publicdomain/zero/1.0/ | A solution to the MiniBooNE excess invoking rare three-body decays of the
charged pions and kaons to new states in the MeV mass scale was recently
proposed as a dark-sector explanation. This class of solution illuminates the
fact that, while the charged pions were focused in the target-mode run, their
decay products were isotropically suppressed in the beam-dump-mode run in which
no excess was observed. This suggests a new physics solution correlated to the
mesonic sector. We investigate an extended set of phenomenological models that
can explain the MiniBooNE excess as a dark sector solution, utilizing
long-lived particles that might be produced in the three-body decays of the
charged mesons and the two-body anomalous decays of the neutral mesons. Over a
broad set of interactions with the long-lived particles, we show that these
scenarios can be compatible with constraints from LSND, KARMEN, and MicroBooNE,
and evaluate the sensitivity of the ongoing and future data taken by the
Coherent CAPTAIN Mills experiment (CCM) to a potential discovery in this
parameter space.
| [
{
"created": "Tue, 5 Sep 2023 22:07:58 GMT",
"version": "v1"
},
{
"created": "Fri, 22 Mar 2024 22:32:00 GMT",
"version": "v2"
},
{
"created": "Sat, 4 May 2024 15:11:03 GMT",
"version": "v3"
},
{
"created": "Tue, 6 Aug 2024 20:46:23 GMT",
"version": "v4"
}
] | 2024-08-08 | [
[
"Aguilar-Arevalo",
"A. A.",
""
],
[
"Biedron",
"S.",
""
],
[
"Boissevain",
"J.",
""
],
[
"Borrego",
"M.",
""
],
[
"Bugel",
"L.",
""
],
[
"Chavez-Estrada",
"M.",
""
],
[
"Conrad",
"J. M.",
""
],
[
"C... | A solution to the MiniBooNE excess invoking rare three-body decays of the charged pions and kaons to new states in the MeV mass scale was recently proposed as a dark-sector explanation. This class of solution illuminates the fact that, while the charged pions were focused in the target-mode run, their decay products were isotropically suppressed in the beam-dump-mode run in which no excess was observed. This suggests a new physics solution correlated to the mesonic sector. We investigate an extended set of phenomenological models that can explain the MiniBooNE excess as a dark sector solution, utilizing long-lived particles that might be produced in the three-body decays of the charged mesons and the two-body anomalous decays of the neutral mesons. Over a broad set of interactions with the long-lived particles, we show that these scenarios can be compatible with constraints from LSND, KARMEN, and MicroBooNE, and evaluate the sensitivity of the ongoing and future data taken by the Coherent CAPTAIN Mills experiment (CCM) to a potential discovery in this parameter space. |
hep-ph/0410260 | Fayet | C. Bouchiat and P. Fayet | Constraints on the parity-violating couplings of a new gauge boson | 6 pages | Phys.Lett.B608:87-94,2005 | 10.1016/j.physletb.2004.12.065 | LPTENS-04/45 | hep-ph | null | High-energy particle physics experiments allow for the possible existence of
a new light, very weakly coupled, neutral gauge boson (the U boson). This one
permits for light (spin-1/2 or spin-0) particles to be acceptable Dark Matter
candidates, by inducing sufficient (stronger than weak) annihilation cross
sections into e+e-. They could be responsible for the bright 511 keV gamma ray
line observed by INTEGRAL from the galactic bulge.
Such a new interaction may have important consequences, especially at lower
energies. Parity-violation atomic-physics experiments provide strong
constraints on such a U boson, if its couplings to quarks and electrons violate
parity. With the constraints coming from an unobserved axionlike behaviour of
this particle, they privilegiate a pure vector coupling of the U boson to
quarks and leptons, unless the corresponding symmetry is broken sufficiently
above the electroweak scale.
| [
{
"created": "Tue, 19 Oct 2004 13:33:51 GMT",
"version": "v1"
}
] | 2009-02-20 | [
[
"Bouchiat",
"C.",
""
],
[
"Fayet",
"P.",
""
]
] | High-energy particle physics experiments allow for the possible existence of a new light, very weakly coupled, neutral gauge boson (the U boson). This one permits for light (spin-1/2 or spin-0) particles to be acceptable Dark Matter candidates, by inducing sufficient (stronger than weak) annihilation cross sections into e+e-. They could be responsible for the bright 511 keV gamma ray line observed by INTEGRAL from the galactic bulge. Such a new interaction may have important consequences, especially at lower energies. Parity-violation atomic-physics experiments provide strong constraints on such a U boson, if its couplings to quarks and electrons violate parity. With the constraints coming from an unobserved axionlike behaviour of this particle, they privilegiate a pure vector coupling of the U boson to quarks and leptons, unless the corresponding symmetry is broken sufficiently above the electroweak scale. |
hep-ph/0703156 | Thomas McElmurry | Fabio Maltoni, Thomas McElmurry, Robert Putman, Scott Willenbrock | Choosing the Factorization Scale in Perturbative QCD | 25 pages, 18 figures | null | null | CP3-07-10 | hep-ph | null | We define the collinear factorization scheme, which absorbs only the
collinear physics into the parton distribution functions. In order to isolate
the collinear physics, we introduce a procedure to combine real and virtual
corrections, canceling infrared singularities prior to integration. In the
collinear scheme, the factorization scale $\mu$ has a simple physical
interpretation as a collinear cutoff. We present a method for choosing the
factorization scale and apply it to the Drell-Yan process; we find $\mu \approx
Q/2$, where $Q$ is the vector-boson invariant mass. We show that, for a wide
variety of collision energies and $Q$, the radiative corrections are small in
the collinear scheme for this choice of factorization scale.
| [
{
"created": "Wed, 14 Mar 2007 19:31:47 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Maltoni",
"Fabio",
""
],
[
"McElmurry",
"Thomas",
""
],
[
"Putman",
"Robert",
""
],
[
"Willenbrock",
"Scott",
""
]
] | We define the collinear factorization scheme, which absorbs only the collinear physics into the parton distribution functions. In order to isolate the collinear physics, we introduce a procedure to combine real and virtual corrections, canceling infrared singularities prior to integration. In the collinear scheme, the factorization scale $\mu$ has a simple physical interpretation as a collinear cutoff. We present a method for choosing the factorization scale and apply it to the Drell-Yan process; we find $\mu \approx Q/2$, where $Q$ is the vector-boson invariant mass. We show that, for a wide variety of collision energies and $Q$, the radiative corrections are small in the collinear scheme for this choice of factorization scale. |
1510.03143 | Marcin Badziak | Ben Allanach, Marcin Badziak, Cyril Hugonie, Robert Ziegler | Gauge Mediation in the NMSSM with a Light Singlet: Sparticles within the
Reach of LHC Run II | Talk given at 18th International Conference From the Planck Scale to
the Electroweak Scale, 25-29 May 2015 Ioannina, Greece, based on
arXiv:1502.05836 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Relatively light stops in gauge mediation models are usually made compatible
with the Higgs mass of 125 GeV by introducing direct Higgs-messenger couplings.
We show that such couplings are not necessary in a simple and predictive model
that combines minimal gauge mediation and the next-to-minimal supersymmetric
standard model (NMSSM). We show that one can obtain a 125 GeV Standard
Model-like Higgs boson with stops as light as 1.1 TeV, thanks to the mixing of
the Higgs with a singlet state at ${\cal O}(90-100)$ GeV that can explain the
LEP excess. In this scenario the singlet-higgs-higgs superfields coupling
$\lambda$ is small and $\tan\beta$ large. Sparticle searches at the LHC may
come with additional $b-$jets or taus and may involve displaced vertices. The
sparticle production cross-section at the 13 TeV LHC can be ${\mathcal
O}(10-100)$ fb, leading to great prospects for discovery in the early phase of
LHC Run II.
| [
{
"created": "Mon, 12 Oct 2015 05:22:16 GMT",
"version": "v1"
}
] | 2015-10-13 | [
[
"Allanach",
"Ben",
""
],
[
"Badziak",
"Marcin",
""
],
[
"Hugonie",
"Cyril",
""
],
[
"Ziegler",
"Robert",
""
]
] | Relatively light stops in gauge mediation models are usually made compatible with the Higgs mass of 125 GeV by introducing direct Higgs-messenger couplings. We show that such couplings are not necessary in a simple and predictive model that combines minimal gauge mediation and the next-to-minimal supersymmetric standard model (NMSSM). We show that one can obtain a 125 GeV Standard Model-like Higgs boson with stops as light as 1.1 TeV, thanks to the mixing of the Higgs with a singlet state at ${\cal O}(90-100)$ GeV that can explain the LEP excess. In this scenario the singlet-higgs-higgs superfields coupling $\lambda$ is small and $\tan\beta$ large. Sparticle searches at the LHC may come with additional $b-$jets or taus and may involve displaced vertices. The sparticle production cross-section at the 13 TeV LHC can be ${\mathcal O}(10-100)$ fb, leading to great prospects for discovery in the early phase of LHC Run II. |
hep-ph/0205118 | Silvano Simula | S. Simula, M. Osipenko, G. Ricco and M. Taiuti | Leading and higher twists in the proton polarised structure function g1p
at large Bjorken-x | Proc. of the IX International Conference on the Structure of Baryons,
Jefferson Lab, March 3-8, 2002 | null | null | preprint RM3-TH/02-9 | hep-ph nucl-th | null | Power corrections to the Q**2 behavior of the Nachtmann moments of the proton
polarized structure function g1p are investigated at large Bjorken-x by
developing a phenomenological fit of both the resonance (including the photon
point) and deep inelastic data up to Q**2 ~ 50 (GeV/c)**2. The leading twist is
treated at NLO in the strong coupling constant and the effects of higher orders
of the perturbative series are estimated using soft-gluon resummation
techniques. In case of the first moment higher-twist effects are found to be
quite small for
Q**2 > 1 (GeV/c)**2, and the singlet axial charge is determined to be a0[10
(GeV/c)**2] = 0.16 +/- 0.09. In case of higher order moments, which are
sensitive to the large-x region, higher-twist effects are significantly reduced
by the introduction of soft gluon contributions, but they are still relevant at
Q**2 ~ few (GeV/c)**2 at variance with the case of the unpolarized transverse
structure function of the proton. This finding suggests that spin-dependent
correlations among partons may have more impact than spin-independent ones. It
is also shown that the parton-hadron local duality is violated in the region of
polarized electroproduction of the Delta(1232) resonance.
| [
{
"created": "Mon, 13 May 2002 06:46:27 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Simula",
"S.",
""
],
[
"Osipenko",
"M.",
""
],
[
"Ricco",
"G.",
""
],
[
"Taiuti",
"M.",
""
]
] | Power corrections to the Q**2 behavior of the Nachtmann moments of the proton polarized structure function g1p are investigated at large Bjorken-x by developing a phenomenological fit of both the resonance (including the photon point) and deep inelastic data up to Q**2 ~ 50 (GeV/c)**2. The leading twist is treated at NLO in the strong coupling constant and the effects of higher orders of the perturbative series are estimated using soft-gluon resummation techniques. In case of the first moment higher-twist effects are found to be quite small for Q**2 > 1 (GeV/c)**2, and the singlet axial charge is determined to be a0[10 (GeV/c)**2] = 0.16 +/- 0.09. In case of higher order moments, which are sensitive to the large-x region, higher-twist effects are significantly reduced by the introduction of soft gluon contributions, but they are still relevant at Q**2 ~ few (GeV/c)**2 at variance with the case of the unpolarized transverse structure function of the proton. This finding suggests that spin-dependent correlations among partons may have more impact than spin-independent ones. It is also shown that the parton-hadron local duality is violated in the region of polarized electroproduction of the Delta(1232) resonance. |
2107.00545 | Seddigheh Tizchang | S. M. Etesami, R. Jafari, M. Mohammadi Najafabadi, S. Tizchang | Searching for lepton flavor violating interactions at future
electron-positron colliders | 13 pages, 2 figures, 3 tables | Phys. Rev. D 104, 015034 (2021) | 10.1103/PhysRevD.104.015034 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Lepton flavor violating interactions are absent in the standard model but are
expected in various beyond standard models. In this work, the potential of the
future circular electron-positron collider to probe the four fermion lepton
flavor couplings via the $e^{+}e^{-}\rightarrow e^{\pm}\tau^{\mp}$ process is
revisited by means of an effective field theory approach. We provide
constraints at $95\%$ CL on the dimension-six Wilson coefficients including
major sources of background processes and considering realistic detector
effects at four expected operation energies $\sqrt{s}=157.5$, $162.5$, $240$
and $365$ GeV according to their corresponding integrated luminosities. We
demonstrate that statistical combination of the results from four
center-of-mass energies improves the sensitivity to the LFV couplings
significantly. We compare the results with the prospects from Belle II with
$50~ ab^{-1}$ and other studies at electron-positron colliders.
| [
{
"created": "Thu, 1 Jul 2021 15:36:31 GMT",
"version": "v1"
},
{
"created": "Sun, 1 Aug 2021 11:44:49 GMT",
"version": "v2"
},
{
"created": "Sun, 26 Sep 2021 11:03:20 GMT",
"version": "v3"
}
] | 2021-09-28 | [
[
"Etesami",
"S. M.",
""
],
[
"Jafari",
"R.",
""
],
[
"Najafabadi",
"M. Mohammadi",
""
],
[
"Tizchang",
"S.",
""
]
] | Lepton flavor violating interactions are absent in the standard model but are expected in various beyond standard models. In this work, the potential of the future circular electron-positron collider to probe the four fermion lepton flavor couplings via the $e^{+}e^{-}\rightarrow e^{\pm}\tau^{\mp}$ process is revisited by means of an effective field theory approach. We provide constraints at $95\%$ CL on the dimension-six Wilson coefficients including major sources of background processes and considering realistic detector effects at four expected operation energies $\sqrt{s}=157.5$, $162.5$, $240$ and $365$ GeV according to their corresponding integrated luminosities. We demonstrate that statistical combination of the results from four center-of-mass energies improves the sensitivity to the LFV couplings significantly. We compare the results with the prospects from Belle II with $50~ ab^{-1}$ and other studies at electron-positron colliders. |
1007.0432 | Pran Nath | Tarek Ibrahim and Pran Nath | The top quark electric dipole moment in an MSSM extension with vector
like multiplets | 21 pages and 5 figues. Accepted for publication in Physical Review D | Phys.Rev.D82:055001,2010 | 10.1103/PhysRevD.82.055001 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The electric dipole moment (EDM) of the top quark is calculated in a model
with a vector like multiplet which mixes with the third generation in an
extension of the MSSM. Such mixings allow for new CP violating phases.
Including these new CP phases, the EDM of the top in this class of models is
computed. The top EDM arises from loops involving the exchange of the W, the Z
as well as from the exchange involving the charginos, the neutralinos, the
gluino, and the vector like multiplet and their superpartners. The analysis of
the EDM of the top is more complicated than for the light quarks because the
mass of the external fermion, in this case the top quark mass cannot be ignored
relative to the masses inside the loops. A numerical analysis is presented and
it is shown that the top EDM could be close to $10^{-19} ecm$ consistent with
the current limits on the EDM of the electron, the neutron and on atomic EDMs.
A top EDM of size $10^{-19}ecm$ could be accessible in collider experiments
such as the ILC.
| [
{
"created": "Fri, 2 Jul 2010 19:09:51 GMT",
"version": "v1"
},
{
"created": "Mon, 9 Aug 2010 17:09:12 GMT",
"version": "v2"
}
] | 2014-11-21 | [
[
"Ibrahim",
"Tarek",
""
],
[
"Nath",
"Pran",
""
]
] | The electric dipole moment (EDM) of the top quark is calculated in a model with a vector like multiplet which mixes with the third generation in an extension of the MSSM. Such mixings allow for new CP violating phases. Including these new CP phases, the EDM of the top in this class of models is computed. The top EDM arises from loops involving the exchange of the W, the Z as well as from the exchange involving the charginos, the neutralinos, the gluino, and the vector like multiplet and their superpartners. The analysis of the EDM of the top is more complicated than for the light quarks because the mass of the external fermion, in this case the top quark mass cannot be ignored relative to the masses inside the loops. A numerical analysis is presented and it is shown that the top EDM could be close to $10^{-19} ecm$ consistent with the current limits on the EDM of the electron, the neutron and on atomic EDMs. A top EDM of size $10^{-19}ecm$ could be accessible in collider experiments such as the ILC. |
hep-ph/9907430 | Carlo Ewerz | Carlo Ewerz, Bryan R. Webber | Multiplicity of (Mini-)Jets at Small x | 14 pages, 5 figures | JHEP 9908 (1999) 019 | 10.1088/1126-6708/1999/08/019 | Cavendish-HEP-99/05, CERN-TH/99-220, DAMTP-1999-79 | hep-ph | null | We derive closed expressions for the mean and variance of the (mini-)jet
multiplicity distribution in hard scattering processes at low x. Here
(mini-)jets are defined as those due to initial-state radiation of gluons with
transverse momenta greater than some resolution scale m_R, where Lambda^2 <<
m_R^2 << Q^2, Lambda being the intrinsic QCD scale and Q the momentum transfer
scale of the hard scattering. Our results are valid to leading order in
log(1/x) but include all sub-leading logarithms of Q^2/m_R^2. As an
illustration, we predict the mini-jet multiplicity in Higgs boson production at
the Large Hadron Collider.
| [
{
"created": "Tue, 20 Jul 1999 14:07:31 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Ewerz",
"Carlo",
""
],
[
"Webber",
"Bryan R.",
""
]
] | We derive closed expressions for the mean and variance of the (mini-)jet multiplicity distribution in hard scattering processes at low x. Here (mini-)jets are defined as those due to initial-state radiation of gluons with transverse momenta greater than some resolution scale m_R, where Lambda^2 << m_R^2 << Q^2, Lambda being the intrinsic QCD scale and Q the momentum transfer scale of the hard scattering. Our results are valid to leading order in log(1/x) but include all sub-leading logarithms of Q^2/m_R^2. As an illustration, we predict the mini-jet multiplicity in Higgs boson production at the Large Hadron Collider. |
1503.05213 | Tigran Kalaydzhyan | Tigran Kalaydzhyan and Edward Shuryak | Collective flow in high-multiplicity proton-proton collisions | 5 pages | Phys. Rev. C 91, 054913 (2015) | 10.1103/PhysRevC.91.054913 | null | hep-ph hep-th nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present an evidence of strong radial flow in high-multiplicity pp
collisions. We analyze the CMS data on the inclusive spectra of the charged
pions, kaons and protons in the LHC $\sqrt{s}=7$ TeV collisions. For
$<N_{\mathrm{tracks}} >\gtrsim 75$ we demonstrate the consistency of the
hydrodynamic description with the (idealized) Gubser's flow. Using a one
parameter fit of the model to experimental data, we obtain the initial fireball
size to be of the order of 1 fm. At smaller multiplicities, the fit cannot be
performed which shows a limitation of the hydrodynamic approach and provides us
with falsifiability of our theory.
| [
{
"created": "Tue, 17 Mar 2015 20:32:21 GMT",
"version": "v1"
}
] | 2015-06-03 | [
[
"Kalaydzhyan",
"Tigran",
""
],
[
"Shuryak",
"Edward",
""
]
] | We present an evidence of strong radial flow in high-multiplicity pp collisions. We analyze the CMS data on the inclusive spectra of the charged pions, kaons and protons in the LHC $\sqrt{s}=7$ TeV collisions. For $<N_{\mathrm{tracks}} >\gtrsim 75$ we demonstrate the consistency of the hydrodynamic description with the (idealized) Gubser's flow. Using a one parameter fit of the model to experimental data, we obtain the initial fireball size to be of the order of 1 fm. At smaller multiplicities, the fit cannot be performed which shows a limitation of the hydrodynamic approach and provides us with falsifiability of our theory. |
2401.17416 | Anil Kumar | Anil Kumar, Anuj Kumar Upadhyay, Sanjib Kumar Agarwalla, Amol Dighe | Probing the interior of Earth using oscillating neutrinos at INO-ICAL | 4 pages, 2 figures; contribution to proceedings of The European
Physical Society Conference on High Energy Physics (EPS-HEP2023) | null | 10.22323/1.449.0198 | null | hep-ph hep-ex physics.ins-det | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Atmospheric neutrinos offer the possibility of exploring the internal
structure of Earth. This information is complementary to the traditional probes
of seismic and gravitational studies. While propagating through Earth, the
multi-GeV neutrinos encounter the Earth's matter effects due to the coherent
forward scattering with the ambient electrons, which alters the neutrino
oscillation probabilities. We present how well an atmospheric neutrino
oscillation experiment like the 50 kt Iron Calorimeter (ICAL) detector at
India-based Neutrino Observatory would validate the presence of Earth's core,
measure the location of the core-mantle boundary (CMB), and probe the dark
matter (DM) inside the Earth in a unique way through Earth matter effects in
neutrino oscillations. Owing to good angular resolution, ICAL can observe the
core-passing neutrinos efficiently. Due to its magnetized setup, it would be
able to observe neutrinos and antineutrinos separately. With 500 kt$\cdot$yr
exposure, the presence of Earth's core can be independently confirmed at ICAL
with a median $\Delta\chi^2$ of 7.45 (4.83) for normal (inverted) mass
ordering. With 1000 kt$\cdot$yr exposure, ICAL would be able to locate the CMB
with a precision of about $\pm$ 250 km at $1\sigma$. It would also be sensitive
to the possible presence of dark matter with 3.5% of the mass of Earth at
$1\sigma$. The charge identification capability of ICAL would play an important
role in achieving these precisions.
| [
{
"created": "Tue, 30 Jan 2024 20:13:51 GMT",
"version": "v1"
}
] | 2024-02-01 | [
[
"Kumar",
"Anil",
""
],
[
"Upadhyay",
"Anuj Kumar",
""
],
[
"Agarwalla",
"Sanjib Kumar",
""
],
[
"Dighe",
"Amol",
""
]
] | Atmospheric neutrinos offer the possibility of exploring the internal structure of Earth. This information is complementary to the traditional probes of seismic and gravitational studies. While propagating through Earth, the multi-GeV neutrinos encounter the Earth's matter effects due to the coherent forward scattering with the ambient electrons, which alters the neutrino oscillation probabilities. We present how well an atmospheric neutrino oscillation experiment like the 50 kt Iron Calorimeter (ICAL) detector at India-based Neutrino Observatory would validate the presence of Earth's core, measure the location of the core-mantle boundary (CMB), and probe the dark matter (DM) inside the Earth in a unique way through Earth matter effects in neutrino oscillations. Owing to good angular resolution, ICAL can observe the core-passing neutrinos efficiently. Due to its magnetized setup, it would be able to observe neutrinos and antineutrinos separately. With 500 kt$\cdot$yr exposure, the presence of Earth's core can be independently confirmed at ICAL with a median $\Delta\chi^2$ of 7.45 (4.83) for normal (inverted) mass ordering. With 1000 kt$\cdot$yr exposure, ICAL would be able to locate the CMB with a precision of about $\pm$ 250 km at $1\sigma$. It would also be sensitive to the possible presence of dark matter with 3.5% of the mass of Earth at $1\sigma$. The charge identification capability of ICAL would play an important role in achieving these precisions. |
2305.09704 | Narmin Huseynova Dr. | Shahin Mamedov, Narmin Akbarova, Minaya Allahverdiyeva | The deuteron charge rad{\i}us $r_c$ in the framework of the hard-wall
AdS/QCD model | 5 pages, 1 table, AYSS-2022 Conference | null | null | null | hep-ph nucl-th | http://creativecommons.org/licenses/by-nc-nd/4.0/ | We study the deuteron charge radius in the framework of a hard-wall AdS/QCD
model. We present basic elements of the hard-wall model and write metrics for
the AdS space. We introduce a vector field with twist $\tau=6$ describing
deuteron in the bulk of AdS space and other vector fields to describe photon
respectively, write an effective action for the bulk fields interactions, find
a $G_1(Q^2)$, $G_2(Q^2)$ and $G_3(Q^2)$ form factors, then quadrupole
$G_Q(Q^2)$ and charge $G_C(Q^2)$ form-factors of a deuteron. Thus, from the
charge $G_C(Q^2)$ form factor we find the deuteron charge radius $R_C$ in the
framework of a hard-wall AdS/QCD model. Then we compare our result with the
results soft-wall model and experimental data.
| [
{
"created": "Tue, 16 May 2023 12:14:44 GMT",
"version": "v1"
}
] | 2023-05-18 | [
[
"Mamedov",
"Shahin",
""
],
[
"Akbarova",
"Narmin",
""
],
[
"Allahverdiyeva",
"Minaya",
""
]
] | We study the deuteron charge radius in the framework of a hard-wall AdS/QCD model. We present basic elements of the hard-wall model and write metrics for the AdS space. We introduce a vector field with twist $\tau=6$ describing deuteron in the bulk of AdS space and other vector fields to describe photon respectively, write an effective action for the bulk fields interactions, find a $G_1(Q^2)$, $G_2(Q^2)$ and $G_3(Q^2)$ form factors, then quadrupole $G_Q(Q^2)$ and charge $G_C(Q^2)$ form-factors of a deuteron. Thus, from the charge $G_C(Q^2)$ form factor we find the deuteron charge radius $R_C$ in the framework of a hard-wall AdS/QCD model. Then we compare our result with the results soft-wall model and experimental data. |
hep-ph/0503070 | Kalmykov Mikhail | M.Yu.Kalmykov (Baylor U. & JINR, Dubna) | About higher order epsilon-expansion of some massive two- and three-loop
master-integrals | 17 pages, LaTeX, 1-eps figure; v3: journal version; new references
added; some unessential typos corrected | Nucl.Phys. B718 (2005) 276-292 | 10.1016/j.nuclphysb.2005.04.027 | null | hep-ph hep-th math-ph math.MP | null | For certain dimensionally-regulated massive two- and three-loop
propagator-type diagrams the higher order epsilon-expansion is constructed.
| [
{
"created": "Mon, 7 Mar 2005 23:07:49 GMT",
"version": "v1"
},
{
"created": "Fri, 11 Mar 2005 00:45:09 GMT",
"version": "v2"
},
{
"created": "Fri, 3 Jun 2005 00:44:39 GMT",
"version": "v3"
}
] | 2010-04-05 | [
[
"Kalmykov",
"M. Yu.",
"",
"Baylor U. & JINR, Dubna"
]
] | For certain dimensionally-regulated massive two- and three-loop propagator-type diagrams the higher order epsilon-expansion is constructed. |
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