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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1311.2370
|
Hai-Yang Cheng
|
Hai-Yang Cheng
|
Mixing angle of $K_1$ axial vector mesons
|
5 pages, talk presented in The XV International Conference on Hadron
Spectroscopy, 4-8 November 2013, Nara,Japan
| null | null | null |
hep-ph hep-ex nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Analyses of various experimental measurements all indicate that the mixing
angle $\theta_{K_1}$ of $K_1(1270)$ and $K_1(1400)$ is in the vicinity of
$33^\circ$ or $57^\circ$. However, whether $\theta_{K_1}$ is greater or less
than $45^\circ$ is still quite controversial. For example, there were two very
recent studies of the strong decays of $K_1$ mesons. One group claimed that
$\theta_{K_1}\approx 60^\circ$, while the other group obtained
$\theta_{K_1}=(33.6\pm4.3)^\circ$. Since the determination of the mixing angles
$\alpha_{^3\!P_1}$ and $\alpha_{^1\!P_1}$ with the former (latter) being the
mixing angle of $f_1(1285)$ ($h_1(1170)$) and $f_1(1420)$ ($h_1(1380)$) in the
flavor basis through mass relations depend on $\theta_{K_1}$, we show that
$\theta_{K_1}\approx 57^\circ$ is ruled out as it leads to a too large
deviation from ideal mixing in the $^1\!P_1$ sector, inconsistent with the
lattice calculation of $\alpha_{^1\!P_1}$ and the observation of strong decays
of $h_1(1170)$ and $h_1(1380)$. We find that for $\theta_{K_1}\approx
(28-30)^\circ$, the corresponding $\alpha_{^3\!P_1}$ and $\alpha_{^1\!P_1}$
agree well with all lattice and phenomenological analyses. This again
reinforces the statement that $\theta_{K_1}\sim 33^\circ$ is much more favored
than $57^\circ$.
|
[
{
"created": "Mon, 11 Nov 2013 08:13:04 GMT",
"version": "v1"
}
] |
2013-11-15
|
[
[
"Cheng",
"Hai-Yang",
""
]
] |
Analyses of various experimental measurements all indicate that the mixing angle $\theta_{K_1}$ of $K_1(1270)$ and $K_1(1400)$ is in the vicinity of $33^\circ$ or $57^\circ$. However, whether $\theta_{K_1}$ is greater or less than $45^\circ$ is still quite controversial. For example, there were two very recent studies of the strong decays of $K_1$ mesons. One group claimed that $\theta_{K_1}\approx 60^\circ$, while the other group obtained $\theta_{K_1}=(33.6\pm4.3)^\circ$. Since the determination of the mixing angles $\alpha_{^3\!P_1}$ and $\alpha_{^1\!P_1}$ with the former (latter) being the mixing angle of $f_1(1285)$ ($h_1(1170)$) and $f_1(1420)$ ($h_1(1380)$) in the flavor basis through mass relations depend on $\theta_{K_1}$, we show that $\theta_{K_1}\approx 57^\circ$ is ruled out as it leads to a too large deviation from ideal mixing in the $^1\!P_1$ sector, inconsistent with the lattice calculation of $\alpha_{^1\!P_1}$ and the observation of strong decays of $h_1(1170)$ and $h_1(1380)$. We find that for $\theta_{K_1}\approx (28-30)^\circ$, the corresponding $\alpha_{^3\!P_1}$ and $\alpha_{^1\!P_1}$ agree well with all lattice and phenomenological analyses. This again reinforces the statement that $\theta_{K_1}\sim 33^\circ$ is much more favored than $57^\circ$.
|
1103.5977
|
Peter Schweitzer
|
B.Pasquini, P.Schweitzer
|
Naive time-reversal odd phenomena in semi-inclusive deep-inelastic
scattering from light-cone constituent quark models
|
10 pages, 7 figures, discussion of evolution effects extended, to
appear in Phys.Rev.D
|
Phys.Rev.D83:114044,2011
|
10.1103/PhysRevD.83.114044
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We present results for leading-twist azimuthal asymmetries in semi-inclusive
lepton-nucleon deep-inelastic scattering due to naively time-reversal odd
transverse-momentum dependent parton distribution functions from the light-cone
constituent quark model. We carefully discuss the range of applicability of the
model, especially with regard to positivity constraints and evolution effects.
We find good agreement with available experimental data from COMPASS and
HERMES, and present predictions to be tested in forthcoming experiments at
Jefferson Lab.
|
[
{
"created": "Wed, 30 Mar 2011 16:07:13 GMT",
"version": "v1"
},
{
"created": "Wed, 1 Jun 2011 18:45:39 GMT",
"version": "v2"
}
] |
2011-07-08
|
[
[
"Pasquini",
"B.",
""
],
[
"Schweitzer",
"P.",
""
]
] |
We present results for leading-twist azimuthal asymmetries in semi-inclusive lepton-nucleon deep-inelastic scattering due to naively time-reversal odd transverse-momentum dependent parton distribution functions from the light-cone constituent quark model. We carefully discuss the range of applicability of the model, especially with regard to positivity constraints and evolution effects. We find good agreement with available experimental data from COMPASS and HERMES, and present predictions to be tested in forthcoming experiments at Jefferson Lab.
|
1612.05558
|
Diogo Boito
|
Diogo Boito, Matthias Jamin, and Ramon Miravitllas
|
Scheme variations of the QCD coupling and tau decays
|
4 pages, 3 figures. Contribution to "The 14th International Workshop
on Tau Lepton Physics", 19--23 September 2016, IHEP, Beijing, China
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The QCD coupling, $\alpha_s$, is not a physical observable since it depends
on conventions related to the renormalization procedure. Here we discuss a
redefinition of the coupling where changes of scheme are parametrised by a
single parameter $C$. The new coupling is denoted $\hat \alpha_s$ and its
running is scheme independent. Moreover, scheme variations become completely
analogous to renormalization scale variations. We discuss how the coupling
$\hat \alpha_s$ can be used in order to optimize predictions for the inclusive
hadronic decays of the tau lepton. Preliminary investigations of the $C$-scheme
in the presence of higher-order terms of the perturbative series are discussed
here for the first time.
|
[
{
"created": "Fri, 16 Dec 2016 17:10:27 GMT",
"version": "v1"
}
] |
2016-12-19
|
[
[
"Boito",
"Diogo",
""
],
[
"Jamin",
"Matthias",
""
],
[
"Miravitllas",
"Ramon",
""
]
] |
The QCD coupling, $\alpha_s$, is not a physical observable since it depends on conventions related to the renormalization procedure. Here we discuss a redefinition of the coupling where changes of scheme are parametrised by a single parameter $C$. The new coupling is denoted $\hat \alpha_s$ and its running is scheme independent. Moreover, scheme variations become completely analogous to renormalization scale variations. We discuss how the coupling $\hat \alpha_s$ can be used in order to optimize predictions for the inclusive hadronic decays of the tau lepton. Preliminary investigations of the $C$-scheme in the presence of higher-order terms of the perturbative series are discussed here for the first time.
|
0808.0626
|
Samu Kurki
|
Paul Hoyer, Matti Jarvinen and Samu Kurki
|
Factorization at fixed Q^2(1-x)
|
18 pages, 6 figures. v2: Version published in JHEP. Text modified as
suggested by the referee
|
JHEP 0810:086,2008
|
10.1088/1126-6708/2008/10/086
|
HIP-2008-26/TH
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider QCD factorization between hard and soft subprocesses in inclusive
reactions where the momentum fraction x of one parton approaches unity as the
hard scale Q^2 -> \infty, such that Q^2(1-x) is fixed. In this "BB limit" the
entire (multi-parton) Fock state containing the high x parton is coherent with
the hard subprocess. The soft contribution is given by a forward multiparton
matrix element. The BB limit corresponds to a fixed (large or small) missing
mass and is thus closely connected to exclusive production. We analyze the
Drell-Yan process h + N -> \gamma^* + X in detail, explaining why the virtual
photon is longitudinally polarized for h = \pi and transversely polarized for h
= p. The BB limit may be relevant also for other phenomena observed at high x,
such as the large single spin asymmetries of p p -> \Lambda^\uparrow X and in p
p^\uparrow -> \pi X.
|
[
{
"created": "Tue, 5 Aug 2008 15:31:56 GMT",
"version": "v1"
},
{
"created": "Fri, 24 Oct 2008 17:00:37 GMT",
"version": "v2"
}
] |
2009-02-18
|
[
[
"Hoyer",
"Paul",
""
],
[
"Jarvinen",
"Matti",
""
],
[
"Kurki",
"Samu",
""
]
] |
We consider QCD factorization between hard and soft subprocesses in inclusive reactions where the momentum fraction x of one parton approaches unity as the hard scale Q^2 -> \infty, such that Q^2(1-x) is fixed. In this "BB limit" the entire (multi-parton) Fock state containing the high x parton is coherent with the hard subprocess. The soft contribution is given by a forward multiparton matrix element. The BB limit corresponds to a fixed (large or small) missing mass and is thus closely connected to exclusive production. We analyze the Drell-Yan process h + N -> \gamma^* + X in detail, explaining why the virtual photon is longitudinally polarized for h = \pi and transversely polarized for h = p. The BB limit may be relevant also for other phenomena observed at high x, such as the large single spin asymmetries of p p -> \Lambda^\uparrow X and in p p^\uparrow -> \pi X.
|
hep-ph/0510411
|
Jorge C. Romao
|
J. C. Romao
|
Neutrino Properties in Supersymmetric Models with R-parity Breaking
|
19 pages, 17 Figures in Postscript. Based on talks given at the
Symposium in Honour of Gustavo C. Branco, Lisbon, 19-20 July 2005, and at the
Corfu Summer Institute on EPP, Corfu, 11-18 September 2005. To appear in the
Proceedings. Uses the appolb.cls LaTeX class
| null | null | null |
hep-ph
| null |
We review supersymmetric models where R-parity is broken either explicitly or
spontaneously. The simplest unified extension of the MSSM with explicit
bilinear R--Parity violation provides a predictive scheme for neutrino masses
and mixings which can account for the observed atmospheric and solar neutrino
anomalies. Despite the smallness of neutrino masses R-parity violation is
observable at present and future high-energy colliders, providing an
unambiguous cross-check of the model. This model can be shown to be an
effective model for the, more theoretically satisfying, spontaneous broken
theory. The main difference in this last case is the appearance of a massless
particle, the majoron, that can modify the decay modes of the Higgs boson,
making it decay invisibly most of the time.
|
[
{
"created": "Mon, 31 Oct 2005 13:06:08 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Romao",
"J. C.",
""
]
] |
We review supersymmetric models where R-parity is broken either explicitly or spontaneously. The simplest unified extension of the MSSM with explicit bilinear R--Parity violation provides a predictive scheme for neutrino masses and mixings which can account for the observed atmospheric and solar neutrino anomalies. Despite the smallness of neutrino masses R-parity violation is observable at present and future high-energy colliders, providing an unambiguous cross-check of the model. This model can be shown to be an effective model for the, more theoretically satisfying, spontaneous broken theory. The main difference in this last case is the appearance of a massless particle, the majoron, that can modify the decay modes of the Higgs boson, making it decay invisibly most of the time.
|
hep-ph/9509242
|
Wang
|
R. D. Peccei and K. Wang
|
Natural Mass Matrices
|
28 pages, LaTex, Sec.5 on strong CP revised
|
Phys.Rev. D53 (1996) 2712-2723
|
10.1103/PhysRevD.53.2712
|
UCLA/95/TEP/29
|
hep-ph
| null |
We introduce the idea of natural mass matrices, an organizing principle
useful in the search for GUT scale quark mass matrix patterns that are
consistent with known CKM constraints and quark mass eigenvalues. An
application of this idea is made in the context of SUSY GUTs and some
potentially ``successful'' GUT scale mass patterns are found. The CKM
predictions of these patterns are presented and some relevant strong CP issues
are discussed.
|
[
{
"created": "Thu, 7 Sep 1995 04:27:13 GMT",
"version": "v1"
},
{
"created": "Fri, 17 Nov 1995 04:57:34 GMT",
"version": "v2"
}
] |
2009-10-28
|
[
[
"Peccei",
"R. D.",
""
],
[
"Wang",
"K.",
""
]
] |
We introduce the idea of natural mass matrices, an organizing principle useful in the search for GUT scale quark mass matrix patterns that are consistent with known CKM constraints and quark mass eigenvalues. An application of this idea is made in the context of SUSY GUTs and some potentially ``successful'' GUT scale mass patterns are found. The CKM predictions of these patterns are presented and some relevant strong CP issues are discussed.
|
hep-ph/0006291
|
O. S. Pavlova
|
A.E. Lobanov and O.S. Pavlova
|
On classical description of radiation from neutral fermion with
anomalous magnetic moment
|
6 pages,latex, v2, typos corrected
|
Phys.Lett. A275 (2000) 1-4
|
10.1016/S0375-9601(00)00471-0
|
DTP-MSU/00-08
|
hep-ph
| null |
Electromagnetic radiation from an uncharged spin 1/2 particle with an
anomalous magnetic moment moving in the classical electromagnetic external
field originates from quantum spin-flip transitions. Although this process has
a purely quantum nature, it was observed for certain particular external field
configurations that, when quantum recoil is neglected, the radiation power
corresponds to the classical radiation from an evolving magnetic dipole. We
argue that this correspondence has a more general validity in the case of an
unpolarized particle and derive a general formula for radiation in terms of the
external field strength and its derivatives. A classical dynamics of the spin
is described by the Bargmann-Michel-Telegdi equation.
|
[
{
"created": "Mon, 26 Jun 2000 12:56:48 GMT",
"version": "v1"
},
{
"created": "Mon, 3 Jul 2000 12:02:50 GMT",
"version": "v2"
}
] |
2009-10-31
|
[
[
"Lobanov",
"A. E.",
""
],
[
"Pavlova",
"O. S.",
""
]
] |
Electromagnetic radiation from an uncharged spin 1/2 particle with an anomalous magnetic moment moving in the classical electromagnetic external field originates from quantum spin-flip transitions. Although this process has a purely quantum nature, it was observed for certain particular external field configurations that, when quantum recoil is neglected, the radiation power corresponds to the classical radiation from an evolving magnetic dipole. We argue that this correspondence has a more general validity in the case of an unpolarized particle and derive a general formula for radiation in terms of the external field strength and its derivatives. A classical dynamics of the spin is described by the Bargmann-Michel-Telegdi equation.
|
1011.3410
|
Jean-Philippe Lansberg
|
J.P. Lansberg, B. Pire, L. Szymanowski
|
Hard exclusive processes in the backward region
|
Contributed to the 35th International Conference on High Energy
Physics -- ICHEP 2010, Paris, France, July 22-28, 2010. 5 pages, 3 figures,
uses PoS.cls (included)
| null | null |
CPHT-PC100.1110
|
hep-ph hep-ex nucl-ex nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We review the potentialities offered by the study of backward exclusive
processes in a new scaling regime, i.e. involving a large -timelike or
spacelike- Q2 photon and a baryonic exchange in the t-channel. We recall the
concept of Transition Distribution Amplitudes (TDAs) containing unique
information on the hadron structure, then discuss how they enter the
description of processes such as backward electroproduction of a pion,
antiproton-proton annihilations into a dilepton + meson as well as into J/psi +
meson. We then discuss first phenomenological studies for processes that are
being analysed at JLAB and HERMES or that will be measured by Panda at
GSI-FAIR. Finally we present outlooks for their theoretical studies based on
approaches such as the pion-cloud model.
|
[
{
"created": "Mon, 15 Nov 2010 14:55:56 GMT",
"version": "v1"
}
] |
2010-11-16
|
[
[
"Lansberg",
"J. P.",
""
],
[
"Pire",
"B.",
""
],
[
"Szymanowski",
"L.",
""
]
] |
We review the potentialities offered by the study of backward exclusive processes in a new scaling regime, i.e. involving a large -timelike or spacelike- Q2 photon and a baryonic exchange in the t-channel. We recall the concept of Transition Distribution Amplitudes (TDAs) containing unique information on the hadron structure, then discuss how they enter the description of processes such as backward electroproduction of a pion, antiproton-proton annihilations into a dilepton + meson as well as into J/psi + meson. We then discuss first phenomenological studies for processes that are being analysed at JLAB and HERMES or that will be measured by Panda at GSI-FAIR. Finally we present outlooks for their theoretical studies based on approaches such as the pion-cloud model.
|
2111.14472
|
Di Wang
|
Qin Qin, Chao Wang, Di Wang, Si-Hong Zhou
|
The factorization-assisted topological-amplitude approach and its
applications
|
Invited review paper for the special issue "Heavy Flavor Physics and
CP Violation" of Advances in High Energy Physics
| null | null | null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
Heavy meson decays provide an important platform for studies of both QCD and
electroweak dynamics, which may contain some portals to understanding of
nonperturbative QCD and physics beyond the Standard Model. The
factorization-assisted topological-amplitude approach was proposed to study
two-body non-leptonic $D$ meson decays, where a promising QCD inspired approach
from first principles is still missing. It was also applied to $B$ meson decays
whose subleading power contributions are difficult to calculate. By factorizing
topological amplitudes into short distance Wilson coefficients and long
distance hadronic matrix elements either to be calculated or to be
parameterized, it provides an effective framework to extract information of
nonperturbative dynamics involved. With important flavor SU(3) breaking effects
taken into account, the data of the decay branching ratios (and also CP
asymmetries in $B$ decays) can be fitted well. The extracted amplitudes were
further applied to make predictions for other observables, such as CP
asymmetries in $D$ decays, mixing parameters in the $D^0-\bar{D}^0$ system, and
so on. By this review, we will describe the formulation of the
factorization-assisted topological-amplitude approach and summarize its
applications in $D$ and $B$ meson decays and highlight some of its
achievements.
|
[
{
"created": "Mon, 29 Nov 2021 11:37:55 GMT",
"version": "v1"
}
] |
2021-11-30
|
[
[
"Qin",
"Qin",
""
],
[
"Wang",
"Chao",
""
],
[
"Wang",
"Di",
""
],
[
"Zhou",
"Si-Hong",
""
]
] |
Heavy meson decays provide an important platform for studies of both QCD and electroweak dynamics, which may contain some portals to understanding of nonperturbative QCD and physics beyond the Standard Model. The factorization-assisted topological-amplitude approach was proposed to study two-body non-leptonic $D$ meson decays, where a promising QCD inspired approach from first principles is still missing. It was also applied to $B$ meson decays whose subleading power contributions are difficult to calculate. By factorizing topological amplitudes into short distance Wilson coefficients and long distance hadronic matrix elements either to be calculated or to be parameterized, it provides an effective framework to extract information of nonperturbative dynamics involved. With important flavor SU(3) breaking effects taken into account, the data of the decay branching ratios (and also CP asymmetries in $B$ decays) can be fitted well. The extracted amplitudes were further applied to make predictions for other observables, such as CP asymmetries in $D$ decays, mixing parameters in the $D^0-\bar{D}^0$ system, and so on. By this review, we will describe the formulation of the factorization-assisted topological-amplitude approach and summarize its applications in $D$ and $B$ meson decays and highlight some of its achievements.
|
1002.4170
|
Gilberto Ramalho
|
G. Ramalho, M.T. Pena and Franz Gross
|
Electromagnetic form factors of the Delta with D-waves
|
Accepted for publication in PRD. Version with typographic and
orthographic corrections. 30 pages, 11 figures
|
Phys.Rev.D81:113011,2010
|
10.1103/PhysRevD.81.113011
|
JLAB-THY-10-1139
|
hep-ph hep-lat nucl-ex nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The electromagnetic form factors of the Delta baryon are evaluated within the
framework of a covariant spectator quark model, where S and D-states are
included in the $\Delta$ wave function. We predict all the four Delta multipole
form factors: the electric charge GE0, the magnetic dipole GM1, the electric
quadrupole GE2 and the magnetic octupole GM3. We compare our predictions with
other theoretical calculations. Our results are compatible with the available
experimental data and recent lattice QCD data.
|
[
{
"created": "Mon, 22 Feb 2010 19:22:23 GMT",
"version": "v1"
},
{
"created": "Sat, 26 Jun 2010 17:55:24 GMT",
"version": "v2"
}
] |
2014-11-20
|
[
[
"Ramalho",
"G.",
""
],
[
"Pena",
"M. T.",
""
],
[
"Gross",
"Franz",
""
]
] |
The electromagnetic form factors of the Delta baryon are evaluated within the framework of a covariant spectator quark model, where S and D-states are included in the $\Delta$ wave function. We predict all the four Delta multipole form factors: the electric charge GE0, the magnetic dipole GM1, the electric quadrupole GE2 and the magnetic octupole GM3. We compare our predictions with other theoretical calculations. Our results are compatible with the available experimental data and recent lattice QCD data.
|
1011.1435
|
Bertram Klein
|
Bertram Klein (1), Jens Braun (2), Bernd-Jochen Schaefer (3) ((1)
Technische Universit\"at M\"unchen, (2) Universit\"at Jena, (3) Universit\"at
Graz)
|
Curvature of the QCD phase transition line in a finite volume
|
7 pages, 2 figures, talk given at the XXVIII International Symposium
on Lattice Field Theory, Lattice2010
|
PoS Lattice2010:193,2010
| null | null |
hep-ph hep-lat
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The curvature which characterizes the QCD phase transition at finite
temperature and small values of the chemical potential is accessible to lattice
simulations. The results for this quantity which have been obtained by several
different lattice simulation methods differ due to different numbers of
flavors, different pion masses and different sizes of the simulation volume. In
order to reconcile these results, it is important to investigate finite-volume
effects on the curvature. We investigate the curvature of the chiral phase
transition line at finite temperature and chemical potential in a finite
volume. We use a phenomenological model for chiral symmetry breaking and apply
non-perturbative functional renormalization group methods which account for
critical long-range fluctuations at the phase transition. We find an
intermediate volume region in which the curvature of the phase transition line
is actually reduced relative to its infinite-volume value, provided periodic
spatial boundary conditions are chosen for the quark fields. Size and location
of this region depend on the value of the pion mass. Such an effect could
account for differences in the curvature between lattice simulations in
differently sized volumes and from functional methods in the infinite volume
limit. We discuss implications of our results for the QCD phase diagram.
|
[
{
"created": "Fri, 5 Nov 2010 15:46:08 GMT",
"version": "v1"
}
] |
2011-04-20
|
[
[
"Klein",
"Bertram",
""
],
[
"Braun",
"Jens",
""
],
[
"Schaefer",
"Bernd-Jochen",
""
]
] |
The curvature which characterizes the QCD phase transition at finite temperature and small values of the chemical potential is accessible to lattice simulations. The results for this quantity which have been obtained by several different lattice simulation methods differ due to different numbers of flavors, different pion masses and different sizes of the simulation volume. In order to reconcile these results, it is important to investigate finite-volume effects on the curvature. We investigate the curvature of the chiral phase transition line at finite temperature and chemical potential in a finite volume. We use a phenomenological model for chiral symmetry breaking and apply non-perturbative functional renormalization group methods which account for critical long-range fluctuations at the phase transition. We find an intermediate volume region in which the curvature of the phase transition line is actually reduced relative to its infinite-volume value, provided periodic spatial boundary conditions are chosen for the quark fields. Size and location of this region depend on the value of the pion mass. Such an effect could account for differences in the curvature between lattice simulations in differently sized volumes and from functional methods in the infinite volume limit. We discuss implications of our results for the QCD phase diagram.
|
hep-ph/9405367
|
Annette Holtkamp
|
G. Ingelman and J. Rathmans
|
Renormalization scale uncertainty in tne DIS 2+1 jet cross-section
|
24 pages, uuencoded compressed tar file, DESY 94-082, TSL-ISV-94-0096
|
Z.Phys. C63 (1994) 589-600
|
10.1007/BF01557625
| null |
hep-ph
| null |
The deep inelastic scattering 2+1 jet cross- section is a useful observable
for precision tests of QCD, e.g. measuring the strong coupling constant
alpha(s). A consistent analysis requires a good understanding of the
theoretical uncertainties and one of the most fundamental ones in QCD is due to
the renormalization scheme and scale ambiguity. Different methods, which have
been proposed to resolve the scale ambiguity, are applied to the 2+1 jet
cross-section and the uncertainty is estimated. It is shown that the
uncertainty can be made smaller by choosing the jet definition in a suitable
way.
|
[
{
"created": "Tue, 24 May 1994 08:35:57 GMT",
"version": "v1"
}
] |
2015-06-25
|
[
[
"Ingelman",
"G.",
""
],
[
"Rathmans",
"J.",
""
]
] |
The deep inelastic scattering 2+1 jet cross- section is a useful observable for precision tests of QCD, e.g. measuring the strong coupling constant alpha(s). A consistent analysis requires a good understanding of the theoretical uncertainties and one of the most fundamental ones in QCD is due to the renormalization scheme and scale ambiguity. Different methods, which have been proposed to resolve the scale ambiguity, are applied to the 2+1 jet cross-section and the uncertainty is estimated. It is shown that the uncertainty can be made smaller by choosing the jet definition in a suitable way.
|
1112.2539
|
Ludwig Greil
|
Ludwig Greil, Thomas R. Hemmert, Andreas Sch\"afer
|
Finite volume corrections to the electromagnetic current of the nucleon
| null | null |
10.1140/epja/i2012-12053-2
| null |
hep-ph hep-lat
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We compute corrections to both the isovector anomalous magnetic moment and
the isovector electromagnetic current of the nucleon to $O(p^3)$ in the
framework of covariant two-flavor Baryon Chiral Perturbation Theory. We then
apply these corrections to lattice data for the anomalous magnetic moment from
the LHPC, RBC & UKQCD and QCDSF collaborations.
|
[
{
"created": "Mon, 12 Dec 2011 13:14:39 GMT",
"version": "v1"
}
] |
2015-06-03
|
[
[
"Greil",
"Ludwig",
""
],
[
"Hemmert",
"Thomas R.",
""
],
[
"Schäfer",
"Andreas",
""
]
] |
We compute corrections to both the isovector anomalous magnetic moment and the isovector electromagnetic current of the nucleon to $O(p^3)$ in the framework of covariant two-flavor Baryon Chiral Perturbation Theory. We then apply these corrections to lattice data for the anomalous magnetic moment from the LHPC, RBC & UKQCD and QCDSF collaborations.
|
hep-ph/9910302
|
Robert Lindebaum
|
R. J. Lindebaum, G. B. Tupper and R. D. Viollier
|
Gauging the Shadow Sector with SO(3)
|
8 pages
|
Mod.Phys.Lett. A15 (2000) 1221-1226
|
10.1142/S0217732300001493
| null |
hep-ph
| null |
We examine the phenomenology of a low-energy extension of the Standard Model,
based on the gauge group SU(3) x SU(2) x U(1) x SO(3), with SO(3) operating in
the shadow sector. This model offers $\nu_{e} \to \nu_{s}$ and $\nu_{\mu} \to
\nu_{\tau}$ oscillations as the solution of the solar and atmospheric neutrino
problems. Moreover, it provides a neutral heavy shadow lepton X that could play
the role of a cold dark matter particle.
|
[
{
"created": "Tue, 12 Oct 1999 03:27:42 GMT",
"version": "v1"
}
] |
2009-10-31
|
[
[
"Lindebaum",
"R. J.",
""
],
[
"Tupper",
"G. B.",
""
],
[
"Viollier",
"R. D.",
""
]
] |
We examine the phenomenology of a low-energy extension of the Standard Model, based on the gauge group SU(3) x SU(2) x U(1) x SO(3), with SO(3) operating in the shadow sector. This model offers $\nu_{e} \to \nu_{s}$ and $\nu_{\mu} \to \nu_{\tau}$ oscillations as the solution of the solar and atmospheric neutrino problems. Moreover, it provides a neutral heavy shadow lepton X that could play the role of a cold dark matter particle.
|
0807.3666
|
Jean-Philippe Lansberg
|
J.P. Lansberg, A. Rakotozafindrabe, P. Artoisenet, D. Blaschke, J.
Cugnon, D. d'Enterria, A. C. Kraan, F. Maltoni, D. Prorok, H. Satz
|
Perspectives on heavy-quarkonium production at the LHC
|
Summary of the round table on quarkonium production held at the Joint
Meeting Heidelberg-Liege-Paris-Wroclaw: Three Days of Strong Interactions and
Astrophysics (HLPW08), Spa, Liege, Belgium, 6-8 March 2008. 30 pages, 12
figures, LaTeX, uses aip-6s.clo, aipproc.cls and aipxfm.sty (included)
| null |
10.1063/1.2987169
| null |
hep-ph hep-ex nucl-ex nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We summarise the perspectives on heavy-quarkonium production at the LHC, both
for proton-proton and heavy-ion runs, as emanating from the round table held at
the HLPW 2008 Conference. The main topics are: present experimental and
theoretical knowledge, experimental capabilities, open questions, recent
theoretical advances and potentialities linked to some new observables.
|
[
{
"created": "Wed, 23 Jul 2008 13:40:57 GMT",
"version": "v1"
}
] |
2009-11-13
|
[
[
"Lansberg",
"J. P.",
""
],
[
"Rakotozafindrabe",
"A.",
""
],
[
"Artoisenet",
"P.",
""
],
[
"Blaschke",
"D.",
""
],
[
"Cugnon",
"J.",
""
],
[
"d'Enterria",
"D.",
""
],
[
"Kraan",
"A. C.",
""
],
[
"Maltoni",
"F.",
""
],
[
"Prorok",
"D.",
""
],
[
"Satz",
"H.",
""
]
] |
We summarise the perspectives on heavy-quarkonium production at the LHC, both for proton-proton and heavy-ion runs, as emanating from the round table held at the HLPW 2008 Conference. The main topics are: present experimental and theoretical knowledge, experimental capabilities, open questions, recent theoretical advances and potentialities linked to some new observables.
|
1612.08047
|
Eric Braaten
|
Eric Braaten, Hans-Werner Hammer, and G. Peter Lepage
|
Open Effective Field Theories from Highly Inelastic Reactions
|
6 pages, presented at 38th International Conference on High Energy
Physics
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The loss of particles due to highly inelastic reactions has previously been
taken into account in effective field theories for low-energy particles by
adding local anti-Hermitian terms to the effective Hamiltonian. An additional
modification is required in the time evolution equation for the density matrix
of a multi-particle system. An effective density matrix can be defined by
tracing over states containing high-momentum particles produced by the highly
inelastic reactions and by a time average that eliminates short-time
correlations. The effective density matrix satisfies the Lindblad equation,
with local Lindblad operators that are determined by the anti-Hermitian terms
in the effective Hamiltonian.
|
[
{
"created": "Fri, 23 Dec 2016 17:29:29 GMT",
"version": "v1"
}
] |
2016-12-26
|
[
[
"Braaten",
"Eric",
""
],
[
"Hammer",
"Hans-Werner",
""
],
[
"Lepage",
"G. Peter",
""
]
] |
The loss of particles due to highly inelastic reactions has previously been taken into account in effective field theories for low-energy particles by adding local anti-Hermitian terms to the effective Hamiltonian. An additional modification is required in the time evolution equation for the density matrix of a multi-particle system. An effective density matrix can be defined by tracing over states containing high-momentum particles produced by the highly inelastic reactions and by a time average that eliminates short-time correlations. The effective density matrix satisfies the Lindblad equation, with local Lindblad operators that are determined by the anti-Hermitian terms in the effective Hamiltonian.
|
hep-ph/0111316
|
Liangsb
|
Chongxing Yue, Hong Li, and Xuelei Wang
|
Signatures of the neutral top-pion in $e\gamma$ collisions
|
latex files,11 pages, 3 figures
|
Mod.Phys.Lett. A17 (2002) 2349
|
10.1142/S0217732302008836
| null |
hep-ph
| null |
We calculate the contributions of the neutral top-pion $\pi_{t}^0$ to the
process $e^-\gamma\to e^-\bar{t}c$ in the framework of topcolor-assisted
technicolor(TC2) models and discuss the possible of detecting $\pi_t^0$ at the
high energy linear $e^+e^-$ collider(LC). Our results show that $\pi_t^0$ can
give significant contributions to this process. With reasonable values of the
parameters in TC2 models, the cross section $\sigma$ can reach 0.19 fb which
may be detected at the $e\gamma$ collisions based on the future LC experiments.
|
[
{
"created": "Sat, 24 Nov 2001 02:18:17 GMT",
"version": "v1"
}
] |
2009-11-07
|
[
[
"Yue",
"Chongxing",
""
],
[
"Li",
"Hong",
""
],
[
"Wang",
"Xuelei",
""
]
] |
We calculate the contributions of the neutral top-pion $\pi_{t}^0$ to the process $e^-\gamma\to e^-\bar{t}c$ in the framework of topcolor-assisted technicolor(TC2) models and discuss the possible of detecting $\pi_t^0$ at the high energy linear $e^+e^-$ collider(LC). Our results show that $\pi_t^0$ can give significant contributions to this process. With reasonable values of the parameters in TC2 models, the cross section $\sigma$ can reach 0.19 fb which may be detected at the $e\gamma$ collisions based on the future LC experiments.
|
1206.1637
|
Taekoon Lee
|
Taekoon Lee
|
Vacuum quark condensate, chiral Lagrangian, and Bose-Einstein statistics
|
4 Pages, To appear in Phys. Lett. B
|
Physics Letters B 713 (2012) pp. 270-272
|
10.1016/j.physletb.2012.06.014
| null |
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In a series of articles it was recently claimed that the quantum
chromodynamic (QCD) condensates are not the properties of the vacuum but of the
hadrons and are confined inside them. We point out that this claim is
incompatible with the chiral Lagrangian and Bose-Einstein statistics of the
Goldstone bosons (pions) in chiral limit and conclude that the quark condensate
must be the property of the QCD vacuum.
|
[
{
"created": "Thu, 7 Jun 2012 22:21:31 GMT",
"version": "v1"
}
] |
2015-06-05
|
[
[
"Lee",
"Taekoon",
""
]
] |
In a series of articles it was recently claimed that the quantum chromodynamic (QCD) condensates are not the properties of the vacuum but of the hadrons and are confined inside them. We point out that this claim is incompatible with the chiral Lagrangian and Bose-Einstein statistics of the Goldstone bosons (pions) in chiral limit and conclude that the quark condensate must be the property of the QCD vacuum.
|
1012.0180
|
Hannu Holopainen
|
Hannu Holopainen, Harri Niemi, Kari J. Eskola
|
Elliptic flow from event-by-event hydrodynamics with fluctuating initial
state
|
4 pages, 5 figures. Talk given at Hard Probes 2010, Eilat, Israel,
10-15 October, 2010
| null |
10.1016/j.nuclphysa.2011.02.112
| null |
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We develop an event-by-event ideal hydrodynamical framework where initial
state density fluctuations are present and where we use a similar flow-analysis
method as in the experiments to make a one-to-one $v_2$ comparison with the
measured data. Our studies also show that the participant plane is quite a good
approximation for the event plane.
|
[
{
"created": "Wed, 1 Dec 2010 12:56:36 GMT",
"version": "v1"
}
] |
2015-05-20
|
[
[
"Holopainen",
"Hannu",
""
],
[
"Niemi",
"Harri",
""
],
[
"Eskola",
"Kari J.",
""
]
] |
We develop an event-by-event ideal hydrodynamical framework where initial state density fluctuations are present and where we use a similar flow-analysis method as in the experiments to make a one-to-one $v_2$ comparison with the measured data. Our studies also show that the participant plane is quite a good approximation for the event plane.
|
hep-ph/0309049
|
Gilberto Colangelo
|
Matthias Buchler and Gilberto Colangelo
|
Renormalization group equations for effective field theories
|
40 pages, 4 figures, plain Latex
|
Eur.Phys.J. C32 (2003) 427-442
|
10.1140/epjc/s2003-01390-2
| null |
hep-ph
| null |
We derive the renormalization group equations for a generic nonrenormalizable
theory. We show that the equations allow one to derive the structure of the
leading divergences at any loop order in terms of one-loop diagrams only. In
chiral perturbation theory, e.g., this means that one can obtain the series of
leading chiral logs by calculating only one loop diagrams. We discuss also the
renormalization group equations for the subleading divergences, and the crucial
role of counterterms that vanish at the equations of motion. Finally, we show
that the renormalization group equations obtained here apply equally well also
to renormalizable theories.
|
[
{
"created": "Thu, 4 Sep 2003 16:49:22 GMT",
"version": "v1"
}
] |
2009-11-10
|
[
[
"Buchler",
"Matthias",
""
],
[
"Colangelo",
"Gilberto",
""
]
] |
We derive the renormalization group equations for a generic nonrenormalizable theory. We show that the equations allow one to derive the structure of the leading divergences at any loop order in terms of one-loop diagrams only. In chiral perturbation theory, e.g., this means that one can obtain the series of leading chiral logs by calculating only one loop diagrams. We discuss also the renormalization group equations for the subleading divergences, and the crucial role of counterterms that vanish at the equations of motion. Finally, we show that the renormalization group equations obtained here apply equally well also to renormalizable theories.
|
hep-ph/9512207
|
Luca Salasnich
|
Luca Salasnich
|
Instabilities, Point Attractors and Limit Cycles in a Inflationary
Universe
|
Latex, 11 pages, 3 figures (available upon request), to be published
in Modern Physics Letters A
|
Mod.Phys.Lett. A10 (1995) 3119-3128
|
10.1142/S0217732395003276
| null |
hep-ph astro-ph
| null |
We study the stability of a scalar inflaton field and analyze its point
attractors in the phase space. We show that the value of the inflaton field in
the vacuum is a bifurcation parameter and prove the possible existence of a
limit cycle by using analytical and numerical arguments.
|
[
{
"created": "Fri, 1 Dec 1995 15:24:53 GMT",
"version": "v1"
}
] |
2009-10-28
|
[
[
"Salasnich",
"Luca",
""
]
] |
We study the stability of a scalar inflaton field and analyze its point attractors in the phase space. We show that the value of the inflaton field in the vacuum is a bifurcation parameter and prove the possible existence of a limit cycle by using analytical and numerical arguments.
|
hep-ph/0210032
|
Taekoon Lee
|
Taekoon Lee
|
Surviving the renormalon in heavy quark potential
|
14 pages, 3 figures, references added, to appear in PRD
|
Phys.Rev. D67 (2003) 014020
|
10.1103/PhysRevD.67.014020
| null |
hep-ph hep-lat
| null |
We show that the Borel resummed perturbative static potential at N_f=0
converges well, and is in a remarkable agreement with the quenched lattice
calculation at distances 1/r > 660 MeV. This shows that Borel resummation is
very good at handling the renormalon in the static potential (and in the pole
mass), and allows one to use the pole mass in perturbative calculation of heavy
quark physics.
|
[
{
"created": "Wed, 2 Oct 2002 10:55:27 GMT",
"version": "v1"
},
{
"created": "Wed, 9 Oct 2002 12:58:57 GMT",
"version": "v2"
},
{
"created": "Mon, 2 Dec 2002 06:49:48 GMT",
"version": "v3"
}
] |
2009-11-07
|
[
[
"Lee",
"Taekoon",
""
]
] |
We show that the Borel resummed perturbative static potential at N_f=0 converges well, and is in a remarkable agreement with the quenched lattice calculation at distances 1/r > 660 MeV. This shows that Borel resummation is very good at handling the renormalon in the static potential (and in the pole mass), and allows one to use the pole mass in perturbative calculation of heavy quark physics.
|
hep-ph/9508309
|
Ivanov D. Y.
|
I.F. Ginzburg, D.Yu. Ivanov, V.G. Serbo
|
Semihard diffractive production of neutral mesons by off shell photons
and the range of pQCD validity
|
LateX, 5 PostScript figures. Some improvements in the text. Two new
figures added
| null | null |
Novosibirsk, Institute of Mathematics, TP-208
|
hep-ph
| null |
We study the dependence on photon virtuality $Q^2$ for the semihard
quasi--elastic photoproduction of neutral vector mesons on a quark, gluon or
real photon (at $s\gg p_{\bot}^2, Q^2; p_{\bot}^2 \gg \mu^2 \approx (0.3$
GeV)$^2$). To this end we calculate the corresponding amplitudes (in an
analytical form) in the lowest nontrivial approximation of the perturbative
QCD. The amplitudes for the production of mesons consisting of light quarks
vary very rapidly with the photon virtuality near $Q^2=0$.
We estimate the bound of the pQCD validity region for such processes. For the
process with mass shell photon the obtained bound is very high, and this region
seems beyond opportunities of real experiment. This bound decreases fast with
the increase of $Q^2$, and we expect that the virtual photoproduction at HERA
provides the opportunity to test the pQCD results. The signature of this region
is discussed.
|
[
{
"created": "Wed, 16 Aug 1995 10:37:53 GMT",
"version": "v1"
},
{
"created": "Thu, 17 Aug 1995 07:07:53 GMT",
"version": "v2"
},
{
"created": "Thu, 2 Nov 1995 15:09:36 GMT",
"version": "v3"
},
{
"created": "Sat, 4 Nov 1995 11:04:55 GMT",
"version": "v4"
}
] |
2008-02-03
|
[
[
"Ginzburg",
"I. F.",
""
],
[
"Ivanov",
"D. Yu.",
""
],
[
"Serbo",
"V. G.",
""
]
] |
We study the dependence on photon virtuality $Q^2$ for the semihard quasi--elastic photoproduction of neutral vector mesons on a quark, gluon or real photon (at $s\gg p_{\bot}^2, Q^2; p_{\bot}^2 \gg \mu^2 \approx (0.3$ GeV)$^2$). To this end we calculate the corresponding amplitudes (in an analytical form) in the lowest nontrivial approximation of the perturbative QCD. The amplitudes for the production of mesons consisting of light quarks vary very rapidly with the photon virtuality near $Q^2=0$. We estimate the bound of the pQCD validity region for such processes. For the process with mass shell photon the obtained bound is very high, and this region seems beyond opportunities of real experiment. This bound decreases fast with the increase of $Q^2$, and we expect that the virtual photoproduction at HERA provides the opportunity to test the pQCD results. The signature of this region is discussed.
|
hep-ph/0010234
|
Rajesh Parwani
|
Rajesh R. Parwani
|
Borel Resummation of the Perturbative Free Energy of Hot Yang-Mills
Theory
|
Revised, Journal version,11 pages Latex, 7 figures
|
Phys.Rev. D63 (2001) 054014
|
10.1103/PhysRevD.63.054014
| null |
hep-ph hep-th
| null |
The divergent perturbative expansion of the free-energy density of thermal
SU(3) gauge theory is resummed into a rapidly convergent series using a novel,
variational, implementation of the method of conformal mapping of the
corresponding Borel series. The resummed result differs significantly from
non-perturbative lattice simulations and the discrepancy is attributed to the
presence of a pole on the positive axis of the Borel plane. The position of
that pole is determined numerically and the difference between the lattice data
and the resummed series is related to a phenomenological bag `constant'.
|
[
{
"created": "Fri, 20 Oct 2000 03:33:58 GMT",
"version": "v1"
},
{
"created": "Sun, 25 Feb 2001 10:52:10 GMT",
"version": "v2"
}
] |
2009-10-31
|
[
[
"Parwani",
"Rajesh R.",
""
]
] |
The divergent perturbative expansion of the free-energy density of thermal SU(3) gauge theory is resummed into a rapidly convergent series using a novel, variational, implementation of the method of conformal mapping of the corresponding Borel series. The resummed result differs significantly from non-perturbative lattice simulations and the discrepancy is attributed to the presence of a pole on the positive axis of the Borel plane. The position of that pole is determined numerically and the difference between the lattice data and the resummed series is related to a phenomenological bag `constant'.
|
hep-ph/0505004
|
Yasaman Farzan
|
Yasaman Farzan
|
On Effects of the Large Neutrino B-Term on Low Energy Physics
|
6 pages, 3 figures, talk presented at the XXXXth Moriond conference
on electroweak interactions and unified theories; v2: minor changes
| null | null |
IPM/P-2005/033
|
hep-ph
| null |
To embed the seesaw mechanism in the MSSM, two or three right-handed neutrino
supermultiplets, $N_i$, have to be added to the model. In this framework, the
supersymmetry breaking potential will include a new term called neutrino
$B$-term: $MB_\nu \tilde{N} \tilde{N}/2$. In this talk, we present a toy model
that generates a large neutrino $B$-term keeping other supersymmetry breaking
parameters small. We then review the consequences of having a large neutrino
$B$-term on the electroweak symmetry breaking parameters and electric dipole
moments (EDMs) of elementary particles.
|
[
{
"created": "Sat, 30 Apr 2005 06:53:07 GMT",
"version": "v1"
},
{
"created": "Tue, 10 May 2005 06:15:01 GMT",
"version": "v2"
}
] |
2007-05-23
|
[
[
"Farzan",
"Yasaman",
""
]
] |
To embed the seesaw mechanism in the MSSM, two or three right-handed neutrino supermultiplets, $N_i$, have to be added to the model. In this framework, the supersymmetry breaking potential will include a new term called neutrino $B$-term: $MB_\nu \tilde{N} \tilde{N}/2$. In this talk, we present a toy model that generates a large neutrino $B$-term keeping other supersymmetry breaking parameters small. We then review the consequences of having a large neutrino $B$-term on the electroweak symmetry breaking parameters and electric dipole moments (EDMs) of elementary particles.
|
hep-ph/9904383
|
Merab Gogberashvili
|
Merab Gogberashvili
|
Four Dimensionality in Non-compact Kaluza-Klein Model
|
6 pages, LaTEX file, no figures, no macros
|
Mod.Phys.Lett. A14 (1999) 2025-2032
|
10.1142/S021773239900208X
| null |
hep-ph gr-qc hep-th
| null |
Five dimensional model with extended dimensions investigated. It is shown
that four dimensionality of our world is the result of stability requirement.
Extra component of Einstein equations giving trapping solution for matter
fields coincides with the one of conditions of stability.
|
[
{
"created": "Mon, 19 Apr 1999 08:17:05 GMT",
"version": "v1"
}
] |
2009-10-31
|
[
[
"Gogberashvili",
"Merab",
""
]
] |
Five dimensional model with extended dimensions investigated. It is shown that four dimensionality of our world is the result of stability requirement. Extra component of Einstein equations giving trapping solution for matter fields coincides with the one of conditions of stability.
|
1008.0593
|
Yoshimi Kanehata
|
Yoshimi Kanehata, Tatsuo Kobayashi, Yasufumi Konishi, Takashi
Shimomura
|
Constraints from Unrealistic Vacua in Supersymmetric Standard Model with
Neutrino Mass Operators
|
11 pages, 4 figures
|
Phys.Rev.D82:075018,2010
|
10.1103/PhysRevD.82.075018
|
YITP-10-65, KUNS-2285, MISC-2010-07, OCHA-PP-302
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We analyze a scalar potential of the minimal supersymmetric standard model
(MSSM) with neutrino mass operators along Unbounded-From-Below (UFB) and Color
and/or Charged Breaking (CCB) directions. We show necessary conditions to avoid
the potential minima which can be deeper than the realistic vacuum. These
conditions would constrain more strongly than conditions in the MSSM without
taking into account neutrino mass operators, and can improve the predictive
power of supersymmetric models with neutrino mass operators.
|
[
{
"created": "Tue, 3 Aug 2010 16:54:34 GMT",
"version": "v1"
}
] |
2010-11-11
|
[
[
"Kanehata",
"Yoshimi",
""
],
[
"Kobayashi",
"Tatsuo",
""
],
[
"Konishi",
"Yasufumi",
""
],
[
"Shimomura",
"Takashi",
""
]
] |
We analyze a scalar potential of the minimal supersymmetric standard model (MSSM) with neutrino mass operators along Unbounded-From-Below (UFB) and Color and/or Charged Breaking (CCB) directions. We show necessary conditions to avoid the potential minima which can be deeper than the realistic vacuum. These conditions would constrain more strongly than conditions in the MSSM without taking into account neutrino mass operators, and can improve the predictive power of supersymmetric models with neutrino mass operators.
|
1212.2266
|
Hyung Do Kim
|
Hyung Do Kim
|
New SUSY Thought
|
6 pages, 4 figures, Plenary Talk given at BSM of Particle Physics
2012, Qui Nhon, Vietnam, 15-21 July 2012
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
New SUSY thought is presented. Maximal stop mixing needed for 125 GeV Higgs
is linked to the tachyonic stop at the UV boundary. Large $\mu$ does not mean
the severe fine tuning if Higgs comes out as a pseudo-Goldstone boson. The
small mass of the pseudo-Goldstone Higgs is overcome with extra vector-like
fermions needed to explain the Higgs to di-photon rates.
|
[
{
"created": "Tue, 11 Dec 2012 01:09:06 GMT",
"version": "v1"
}
] |
2012-12-12
|
[
[
"Kim",
"Hyung Do",
""
]
] |
New SUSY thought is presented. Maximal stop mixing needed for 125 GeV Higgs is linked to the tachyonic stop at the UV boundary. Large $\mu$ does not mean the severe fine tuning if Higgs comes out as a pseudo-Goldstone boson. The small mass of the pseudo-Goldstone Higgs is overcome with extra vector-like fermions needed to explain the Higgs to di-photon rates.
|
hep-ph/9705453
|
Susan Gardner
|
S. Gardner, H.B. O'Connell (Kentucky), A.W. Thomas (Adelaide)
|
Rho-Omega Mixing and Direct CP Violation in Hadronic B-Decays
|
9 pages, REVTeX, 1 ps figure, major style changes, results unchanged
|
Phys.Rev.Lett.80:1834-1837,1998
|
10.1103/PhysRevLett.80.1834
|
UK/TP 97-09, ADP-97-15/T252
|
hep-ph
| null |
The extraction of CKM-matrix-element information from hadronic B-decays
generally suffers from discrete ambiguities, hampering the diagnosis of physics
beyond the Standard Model. We show that a measurement of the rate asymmetry,
which is CP-violating, in
$B^{\pm}\to\rho^{\pm}\rho^0(\omega)\to\rho^{\pm}\pi^+\pi^-$, where the
invariant mass of the $\pi^+\pi^-$ pair is in the vicinity of the $\omega$
resonance, can remove the mod($\pi$) uncertainty in $\alpha\equiv arg [-V_{td}
V_{tb}^\ast/(V_{ud}V_{ub}^\ast)]$ present in standard analyses.
|
[
{
"created": "Wed, 28 May 1997 16:37:35 GMT",
"version": "v1"
},
{
"created": "Fri, 17 Apr 1998 02:14:27 GMT",
"version": "v2"
}
] |
2008-11-26
|
[
[
"Gardner",
"S.",
"",
"Kentucky"
],
[
"O'Connell",
"H. B.",
"",
"Kentucky"
],
[
"Thomas",
"A. W.",
"",
"Adelaide"
]
] |
The extraction of CKM-matrix-element information from hadronic B-decays generally suffers from discrete ambiguities, hampering the diagnosis of physics beyond the Standard Model. We show that a measurement of the rate asymmetry, which is CP-violating, in $B^{\pm}\to\rho^{\pm}\rho^0(\omega)\to\rho^{\pm}\pi^+\pi^-$, where the invariant mass of the $\pi^+\pi^-$ pair is in the vicinity of the $\omega$ resonance, can remove the mod($\pi$) uncertainty in $\alpha\equiv arg [-V_{td} V_{tb}^\ast/(V_{ud}V_{ub}^\ast)]$ present in standard analyses.
|
hep-ph/0510026
|
Carlos A. Salgado
|
Carlos A. Salgado
|
Medium-Modified Jet Shapes in Heavy-Ion Collisions
|
4 pages.Contribution to the XIth International Conference on Elastic
and Diffractive Scattering. Blois 2005
| null | null |
CERN-PH-TH/2005-187
|
hep-ph
| null |
Jet quenching has been established as one of the main tools to study the
properties of the medium produced in heavy ion collisions. Most of the
experimental effort has been, up to now, on the measurements of inclusive
particle suppression. This observable suffers, however, of limitations due to
different trigger-bias effects. The study of jets (or particle correlations) in
a medium is the most promising way out for a better characterization of the
medium properties. I will present how these more differential measurements can
be used to study not only the density of the medium (the traditional parameter
fixed by jet quenching measurements) but also more dynamical quantities as flow
fields.
|
[
{
"created": "Mon, 3 Oct 2005 15:32:07 GMT",
"version": "v1"
}
] |
2016-09-06
|
[
[
"Salgado",
"Carlos A.",
""
]
] |
Jet quenching has been established as one of the main tools to study the properties of the medium produced in heavy ion collisions. Most of the experimental effort has been, up to now, on the measurements of inclusive particle suppression. This observable suffers, however, of limitations due to different trigger-bias effects. The study of jets (or particle correlations) in a medium is the most promising way out for a better characterization of the medium properties. I will present how these more differential measurements can be used to study not only the density of the medium (the traditional parameter fixed by jet quenching measurements) but also more dynamical quantities as flow fields.
|
hep-ph/9301214
| null |
George Triantaphyllou
|
QED Radiative Corrections to the Decay $\pi^{0} \rightarrow e^{+}e^{-}$
|
16 Latex pages, 3 figures not included, available upon request,
YCTP-P1-93
|
Mod.Phys.Lett. A8 (1993) 1691-1700
|
10.1142/S0217732393001434
| null |
hep-ph
| null |
In view of the recent interest in the decays of mesons into a pair of light
leptons, a computation of the QED radiative corrections to the decay of
$\pi^{0}$ into an electron-positron pair is presented here. The results
indicate that the peak value of the differential decay rate is reduced by about
$50 \%$, because of soft-photon radiation. The number of $e^{+}e^{-}$ pairs
having invariant masses in an energy bin of 0.5 MeV centered around $m_{\pi}$
is found to be about $20 \%$ smaller than the one it would be if radiative
corrections were neglected.
|
[
{
"created": "Thu, 7 Jan 1993 16:16:16 GMT",
"version": "v1"
}
] |
2015-06-25
|
[
[
"Triantaphyllou",
"George",
""
]
] |
In view of the recent interest in the decays of mesons into a pair of light leptons, a computation of the QED radiative corrections to the decay of $\pi^{0}$ into an electron-positron pair is presented here. The results indicate that the peak value of the differential decay rate is reduced by about $50 \%$, because of soft-photon radiation. The number of $e^{+}e^{-}$ pairs having invariant masses in an energy bin of 0.5 MeV centered around $m_{\pi}$ is found to be about $20 \%$ smaller than the one it would be if radiative corrections were neglected.
|
0707.4442
|
Wanda Maria Alberico
|
W.M. Alberico, S. Chiacchiera, H. Hansen, A. Molinari and M. Nardi
|
Shear Viscosity of Quark Matter
|
15 pages, 4 figures
|
Eur.Phys.J.A38:97-103,2008
|
10.1140/epja/i2008-10648-8
| null |
hep-ph
| null |
We consider the shear viscosity of a system of quarks and its ratio to the
entropy density above the critical temperature for deconfinement. Both
quantities are derived and computed for different modeling of the quark
self-energy, also allowing for a temperature dependence of the effective mass
and width. The behaviour of the viscosity and the entropy density is argued in
terms of the strength of the coupling and of the main characteristics of the
quark self-energy. A comparison with existing results is also discussed.
|
[
{
"created": "Mon, 30 Jul 2007 16:54:19 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Alberico",
"W. M.",
""
],
[
"Chiacchiera",
"S.",
""
],
[
"Hansen",
"H.",
""
],
[
"Molinari",
"A.",
""
],
[
"Nardi",
"M.",
""
]
] |
We consider the shear viscosity of a system of quarks and its ratio to the entropy density above the critical temperature for deconfinement. Both quantities are derived and computed for different modeling of the quark self-energy, also allowing for a temperature dependence of the effective mass and width. The behaviour of the viscosity and the entropy density is argued in terms of the strength of the coupling and of the main characteristics of the quark self-energy. A comparison with existing results is also discussed.
|
hep-ph/9708329
|
Raman Sundrum
|
Raman Sundrum (Boston University)
|
Towards an Effective Particle-String Resolution of the Cosmological
Constant Problem
|
25 pages, Latex. References added. Section 4 re-written
|
JHEP 9907:001,1999
|
10.1088/1126-6708/1999/07/001
|
BUHEP-97-24
|
hep-ph gr-qc hep-th
| null |
The Cosmological Constant Problem is re-examined from an effective field
theory perspective. While the connection between gravity and particle physics
has not been experimentally probed in the quantum regime, it is severely
constrained by the successes of Standard Model quantum field theory at short
distances, and classical General Relativity at large distances. At first sight,
it appears that combining particle physics and gravity inevitably leads to an
effective field theory below the weak scale which suffers from large radiative
corrections to the cosmological constant. Consequently, this parameter must be
very finely tuned to lie within the experimental bounds. An analog of just this
type of predicament, and its resolution, are described in some detail using
only familiar quantum field theory. The loop-hole abstracted from the analogy
is the possibility of graviton ``compositeness'' at a scale less than $10^{-2}$
eV, which cuts off the large contributions to the cosmological constant from
standard model physics. Experimentally, this would show up as a dramatic
breakdown of Newton's Law in upcoming sub-centimeter tests of gravity.
Currently, strings are the only known example of such compositeness. It is
proposed that the gravitational sector comprises strings of very low tension,
which couple to a stringy ``halo'' surrounding each point-like standard model
particle.
|
[
{
"created": "Tue, 12 Aug 1997 19:51:52 GMT",
"version": "v1"
},
{
"created": "Wed, 21 Jan 1998 22:16:23 GMT",
"version": "v2"
}
] |
2009-10-30
|
[
[
"Sundrum",
"Raman",
"",
"Boston University"
]
] |
The Cosmological Constant Problem is re-examined from an effective field theory perspective. While the connection between gravity and particle physics has not been experimentally probed in the quantum regime, it is severely constrained by the successes of Standard Model quantum field theory at short distances, and classical General Relativity at large distances. At first sight, it appears that combining particle physics and gravity inevitably leads to an effective field theory below the weak scale which suffers from large radiative corrections to the cosmological constant. Consequently, this parameter must be very finely tuned to lie within the experimental bounds. An analog of just this type of predicament, and its resolution, are described in some detail using only familiar quantum field theory. The loop-hole abstracted from the analogy is the possibility of graviton ``compositeness'' at a scale less than $10^{-2}$ eV, which cuts off the large contributions to the cosmological constant from standard model physics. Experimentally, this would show up as a dramatic breakdown of Newton's Law in upcoming sub-centimeter tests of gravity. Currently, strings are the only known example of such compositeness. It is proposed that the gravitational sector comprises strings of very low tension, which couple to a stringy ``halo'' surrounding each point-like standard model particle.
|
1608.05353
|
Daniel Pitonyak
|
D. Pitonyak
|
Transverse spin observables in hard-scattering hadronic processes within
collinear factorization
|
Typos corrected, references added/updated, invited review accepted in
International Journal of Modern Physics A; 32 pages, 9 figures, 2 tables
| null |
10.1142/S0217751X16300490
|
RBRC-1201
|
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We review what is currently known about the transverse spin structure of
hadrons, in particular from observables that can be analyzed within a collinear
framework. These effects have been around for 40 years and represent a critical
test of perturbative QCD. We look at both proton-proton and lepton-nucleon
collisions for various final states. While the main focus is on transverse
single-spin asymmetries, we also discuss how longitudinal-transverse
double-spin asymmetries offer a complimentary, yet equally important, source of
information on the quark-gluon content of hadrons. We also summarize some
recent progress in solidifying the theoretical formalism behind these
observables and give an outlook on future directions of research.
|
[
{
"created": "Thu, 18 Aug 2016 18:07:01 GMT",
"version": "v1"
},
{
"created": "Mon, 26 Sep 2016 16:36:21 GMT",
"version": "v2"
}
] |
2016-12-21
|
[
[
"Pitonyak",
"D.",
""
]
] |
We review what is currently known about the transverse spin structure of hadrons, in particular from observables that can be analyzed within a collinear framework. These effects have been around for 40 years and represent a critical test of perturbative QCD. We look at both proton-proton and lepton-nucleon collisions for various final states. While the main focus is on transverse single-spin asymmetries, we also discuss how longitudinal-transverse double-spin asymmetries offer a complimentary, yet equally important, source of information on the quark-gluon content of hadrons. We also summarize some recent progress in solidifying the theoretical formalism behind these observables and give an outlook on future directions of research.
|
1906.07163
|
Inbum Lee
|
I. Lee, J. Shortino, J. Biermen, A. Din, A. Grossman, M. Gabel, E.
Guess, C.-Y. Liu, J.C. Long, S. Reger, A. Reid, M. Severinov, B. Short, W.M.
Snow, E. Smith, M. Zhang, and the ARIADNE Collaboration
|
Exotic Spin-Dependent Interaction Searches at Indiana University
|
Presented at the Eighth Meeting on CPT and Lorentz Symmetry,
Bloomington, Indiana, May 12-16, 2019
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The axion is a hypothesized particle appearing in various theories beyond the
Standard Model. It is a light spin-0 boson initially postulated to solve the
strong CP problem and is also a strong candidate for dark matter. If the axion
or an axion-like particle exists, it would mediate a P-odd and T-odd
spin-dependent interaction. We describe two experiments under development at
Indiana University-Bloomington to search for such an interaction.
|
[
{
"created": "Fri, 14 Jun 2019 21:01:59 GMT",
"version": "v1"
}
] |
2019-06-19
|
[
[
"Lee",
"I.",
""
],
[
"Shortino",
"J.",
""
],
[
"Biermen",
"J.",
""
],
[
"Din",
"A.",
""
],
[
"Grossman",
"A.",
""
],
[
"Gabel",
"M.",
""
],
[
"Guess",
"E.",
""
],
[
"Liu",
"C. -Y.",
""
],
[
"Long",
"J. C.",
""
],
[
"Reger",
"S.",
""
],
[
"Reid",
"A.",
""
],
[
"Severinov",
"M.",
""
],
[
"Short",
"B.",
""
],
[
"Snow",
"W. M.",
""
],
[
"Smith",
"E.",
""
],
[
"Zhang",
"M.",
""
],
[
"Collaboration",
"the ARIADNE",
""
]
] |
The axion is a hypothesized particle appearing in various theories beyond the Standard Model. It is a light spin-0 boson initially postulated to solve the strong CP problem and is also a strong candidate for dark matter. If the axion or an axion-like particle exists, it would mediate a P-odd and T-odd spin-dependent interaction. We describe two experiments under development at Indiana University-Bloomington to search for such an interaction.
|
hep-ph/0305119
|
Jose Santiago
|
F. del Aguila, M. Perez-Victoria, J. Santiago
|
Some consequences of brane kinetic terms for bulk fermions
|
6 pages. Based on the talk given by J.S. at the XXXVIII Rencontres de
Moriond (Electroweak Session), includes style file
| null | null |
IPPP/03/26
|
hep-ph
| null |
In theories with extra dimensions there are generically brane kinetic terms
for fields living in the bulk. These modify the masses and wave functions of
the Kaluza-Klein expansions, and then the effective four dimensional gauge and
Yukawa couplings of the corresponding modes. Here, we discuss some
phenomenological consequences of fermion brane kinetic terms, emphasizing their
implications for models with low compactification scales, whose agreement with
experiment can be improved, and observable effects at collider energies, like
the production of new fermions.
|
[
{
"created": "Mon, 12 May 2003 11:05:57 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"del Aguila",
"F.",
""
],
[
"Perez-Victoria",
"M.",
""
],
[
"Santiago",
"J.",
""
]
] |
In theories with extra dimensions there are generically brane kinetic terms for fields living in the bulk. These modify the masses and wave functions of the Kaluza-Klein expansions, and then the effective four dimensional gauge and Yukawa couplings of the corresponding modes. Here, we discuss some phenomenological consequences of fermion brane kinetic terms, emphasizing their implications for models with low compactification scales, whose agreement with experiment can be improved, and observable effects at collider energies, like the production of new fermions.
|
hep-ph/9308337
|
Chris Quigg
|
Estia J. Eichten, Christopher T. Hill, and Chris Quigg
|
Properties of Orbitally Excited Heavy-Light Mesons
|
10 pages, FERMILAB--Pub--93/255--T (uses REVTEX macros)
|
Phys.Rev.Lett.71:4116-4119,1993
|
10.1103/PhysRevLett.71.4116
| null |
hep-ph
| null |
Orbitally excited heavy-light mesons are potentially important as tools for
tagging the flavors and momenta of ground-state pseudoscalars detected through
weak decays. We use heavy-quark symmetry supplemented by insights gleaned from
potential models to estimate masses and widths of $p$-wave $B$, $B_s$, and
$D_s$ mesons. We generalize these results to higher excitations.
|
[
{
"created": "Wed, 25 Aug 1993 21:10:59 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Eichten",
"Estia J.",
""
],
[
"Hill",
"Christopher T.",
""
],
[
"Quigg",
"Chris",
""
]
] |
Orbitally excited heavy-light mesons are potentially important as tools for tagging the flavors and momenta of ground-state pseudoscalars detected through weak decays. We use heavy-quark symmetry supplemented by insights gleaned from potential models to estimate masses and widths of $p$-wave $B$, $B_s$, and $D_s$ mesons. We generalize these results to higher excitations.
|
1502.07824
|
Yuji Omura
|
Yuji Omura, Eibun Senaha, Kazuhiro Tobe
|
Lepton-flavor-violating Higgs decay $h \to \mu\tau$ and muon anomalous
magnetic moment in a general two Higgs doublet model
|
6 pages, 3 figures, revised Fig.3, corrected Eq. (12), added
references, accepted for publication in JHEP
| null |
10.1007/JHEP05(2015)028
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
A two Higgs doublet model (2HDM) is one of the minimal extensions of the
Standard Model (SM), and it is well-known that the general setup predicts the
flavor-violating phenomena, mediated by neutral Higgs interactions. Recently
the CMS collaboration has reported an excess of the lepton-flavor-violating
Higgs decay in $h \rightarrow \mu \tau$ channel with a significance of 2.5 $
\sigma$. We investigate the CMS excess in a general 2HDM with tree-level Flavor
Changing Neutral Currents (FCNCs), and discuss its impact on the other physical
observations. Especially, we see that the FCNCs relevant to the excess can
enhance the neutral Higgs contributions to the muon anomalous magnetic moment,
and can resolve the discrepancy between the measured value and the SM
prediction. We also find that the couplings to be consistent with the muon g-2
anomaly as well as the CMS excess in $h\rightarrow \mu\tau$ predict the sizable
rate of $ \tau \rightarrow \mu \gamma$, which is within the reach of future B
factory.
|
[
{
"created": "Fri, 27 Feb 2015 07:08:42 GMT",
"version": "v1"
},
{
"created": "Sat, 4 Jul 2015 11:47:46 GMT",
"version": "v2"
}
] |
2017-09-13
|
[
[
"Omura",
"Yuji",
""
],
[
"Senaha",
"Eibun",
""
],
[
"Tobe",
"Kazuhiro",
""
]
] |
A two Higgs doublet model (2HDM) is one of the minimal extensions of the Standard Model (SM), and it is well-known that the general setup predicts the flavor-violating phenomena, mediated by neutral Higgs interactions. Recently the CMS collaboration has reported an excess of the lepton-flavor-violating Higgs decay in $h \rightarrow \mu \tau$ channel with a significance of 2.5 $ \sigma$. We investigate the CMS excess in a general 2HDM with tree-level Flavor Changing Neutral Currents (FCNCs), and discuss its impact on the other physical observations. Especially, we see that the FCNCs relevant to the excess can enhance the neutral Higgs contributions to the muon anomalous magnetic moment, and can resolve the discrepancy between the measured value and the SM prediction. We also find that the couplings to be consistent with the muon g-2 anomaly as well as the CMS excess in $h\rightarrow \mu\tau$ predict the sizable rate of $ \tau \rightarrow \mu \gamma$, which is within the reach of future B factory.
|
0812.2958
|
Alfredo Aranda
|
Alfredo Aranda (Colima U.)
|
Electroweak scale neutrinos and Higgses
|
8 pages, 3 figures, talk given at the XIII Mexican School of
Particles and Fields, 2-11 October, 2008, Sonora, Mexico
|
AIP Conf.Proc.1116:227-234,2009
|
10.1063/1.3131560
|
DCP-08-05
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We present two different models with electroweak scale right-handed
neutrinos. One of the models is created under the constraint that any addition
to the Standard Model must not introduce new higher scales. The model contains
right-handed neutrinos with electroweak scale masses and a lepton number
violating singlet scalar field. The scalar phenomenology is also presented. The
second model is a triplet Higgs model where again the right-handed neutrinos
have electroweak scale masses. In this case the model has a rich scalar
phenomenology and in particular we present the analysis involving the doubly
charged Higgs.
|
[
{
"created": "Tue, 16 Dec 2008 02:12:10 GMT",
"version": "v1"
}
] |
2009-04-24
|
[
[
"Aranda",
"Alfredo",
"",
"Colima U."
]
] |
We present two different models with electroweak scale right-handed neutrinos. One of the models is created under the constraint that any addition to the Standard Model must not introduce new higher scales. The model contains right-handed neutrinos with electroweak scale masses and a lepton number violating singlet scalar field. The scalar phenomenology is also presented. The second model is a triplet Higgs model where again the right-handed neutrinos have electroweak scale masses. In this case the model has a rich scalar phenomenology and in particular we present the analysis involving the doubly charged Higgs.
|
1407.4922
|
Qiang Li
|
Yiwen Wen, Huilin Qu, Daneng Yang, Qi-shu Yan, Qiang Li, Yajun Mao
|
Probing Triple-W Production and Anomalous WWWW Coupling at the CERN LHC
and future 100TeV proton-proton collider
|
Accepted version by JHEP
| null |
10.1007/JHEP03(2015)025
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Triple gauge boson production at the LHC can be used to test the robustness
of the Standard Model and provide useful information for VBF di-boson
scattering measurement. Especially, any derivations from SM prediction will
indicate possible new physics. In this paper we present a detailed Monte Carlo
study on measuring WWW production in pure leptonic and semileptonic decays, and
probing anomalous quartic gauge WWWW couplings at the CERN LHC and future
hadron collider, with parton shower and detector simulation effects taken into
account. Apart from cut-based method, multivariate boosted decision tree method
has been exploited for possible improvement. For the leptonic decay channel,
our results show that at the sqrt{s}=8(14)[100] TeV pp collider with integrated
luminosity of 20(100)[3000] fb-1, one can reach a significance of
0.4(1.2)[10]sigma to observe the SM WWW production. For the semileptonic decay
channel, one can have 0.5(2)[14]sigma to observe the SM WWW production. We also
give constraints on relevant Dim-8 anomalous WWWW coupling parameters.
|
[
{
"created": "Fri, 18 Jul 2014 09:06:10 GMT",
"version": "v1"
},
{
"created": "Wed, 18 Feb 2015 07:14:31 GMT",
"version": "v2"
}
] |
2015-06-22
|
[
[
"Wen",
"Yiwen",
""
],
[
"Qu",
"Huilin",
""
],
[
"Yang",
"Daneng",
""
],
[
"Yan",
"Qi-shu",
""
],
[
"Li",
"Qiang",
""
],
[
"Mao",
"Yajun",
""
]
] |
Triple gauge boson production at the LHC can be used to test the robustness of the Standard Model and provide useful information for VBF di-boson scattering measurement. Especially, any derivations from SM prediction will indicate possible new physics. In this paper we present a detailed Monte Carlo study on measuring WWW production in pure leptonic and semileptonic decays, and probing anomalous quartic gauge WWWW couplings at the CERN LHC and future hadron collider, with parton shower and detector simulation effects taken into account. Apart from cut-based method, multivariate boosted decision tree method has been exploited for possible improvement. For the leptonic decay channel, our results show that at the sqrt{s}=8(14)[100] TeV pp collider with integrated luminosity of 20(100)[3000] fb-1, one can reach a significance of 0.4(1.2)[10]sigma to observe the SM WWW production. For the semileptonic decay channel, one can have 0.5(2)[14]sigma to observe the SM WWW production. We also give constraints on relevant Dim-8 anomalous WWWW coupling parameters.
|
hep-ph/0405164
|
Valery Lyubovitskij
|
Amand Faessler (Tuebingen U.), Th. Gutsche (Tuebingen U.), Sergey
Kovalenko (Santa Maria U., Valparaiso), V. E. Lyubovitskij (Tuebingen U.),
Ivan Schmidt (Santa Maria U., Valparaiso), F. Simkovic (Tuebingen U.)
|
Effective Lagrangian approach to nuclear mu-e conversion and the role of
vector mesons
|
19 pages, 3 figures, to be published in Phys Rev D
|
Phys.Rev. D70 (2004) 055008
|
10.1103/PhysRevD.70.055008
|
Preprint USM-TH-153
|
hep-ph
| null |
We study nuclear mu-e conversion in the general framework of an effective
Lagrangian approach without referring to any specific realization of the
physics beyond the standard model (SM) responsible for lepton flavor violation
(LFV). We examine the impact of a specific hadronization prescription on the
analysis of new physics in nuclear mu-e conversion and stress the importance of
vector meson exchange between lepton and nucleon currents. A new issue of this
mechanism is the presence of the strange quark vector current contribution
induced by the phi meson. This allows us to extract new limits on the LFV
lepton-quark effective couplings from the existing experimental data.
|
[
{
"created": "Tue, 18 May 2004 09:58:15 GMT",
"version": "v1"
},
{
"created": "Mon, 26 Jul 2004 13:13:12 GMT",
"version": "v2"
}
] |
2007-05-23
|
[
[
"Faessler",
"Amand",
"",
"Tuebingen U."
],
[
"Gutsche",
"Th.",
"",
"Tuebingen U."
],
[
"Kovalenko",
"Sergey",
"",
"Santa Maria U., Valparaiso"
],
[
"Lyubovitskij",
"V. E.",
"",
"Tuebingen U."
],
[
"Schmidt",
"Ivan",
"",
"Santa Maria U., Valparaiso"
],
[
"Simkovic",
"F.",
"",
"Tuebingen U."
]
] |
We study nuclear mu-e conversion in the general framework of an effective Lagrangian approach without referring to any specific realization of the physics beyond the standard model (SM) responsible for lepton flavor violation (LFV). We examine the impact of a specific hadronization prescription on the analysis of new physics in nuclear mu-e conversion and stress the importance of vector meson exchange between lepton and nucleon currents. A new issue of this mechanism is the presence of the strange quark vector current contribution induced by the phi meson. This allows us to extract new limits on the LFV lepton-quark effective couplings from the existing experimental data.
|
2306.15471
|
Hiroyuki Ishida
|
He-Xu Zhang, Hiroyuki Ishida, Shinya Matsuzaki
|
Dynamical realization of the small field inflation of Coleman-Weinberg
type in the post supercooled universe
|
7 pages, 2 figures, version accepted for publication in PLB
| null |
10.1016/j.physletb.2023.138256
| null |
hep-ph astro-ph.CO hep-th
|
http://creativecommons.org/licenses/by/4.0/
|
The small field inflation (SFI) of Coleman-Weinberg (CW) type suffers from
precise tuning of the initial inflaton field value to be away from the true
vacuum one. We propose a dynamical trapping mechanism to solve this problem: an
ultra-supercooling caused by an almost scale-invariant CW potential traps the
inflaton at the false vacuum, far away from the true vacuum dominantly created
by the quantum scale anomaly, and allows the inflaton to dynamically start the
slow-roll down due to a classical explicit-scale breaking effect. To be
concrete, we employ a successful CW-SFI model and show that the proposed
mechanism works consistently with the observed bounds on the inflation
parameters. The proposed new mechanism thus provides new insights for
developing small field inflation models.
|
[
{
"created": "Tue, 27 Jun 2023 13:45:44 GMT",
"version": "v1"
},
{
"created": "Wed, 18 Oct 2023 07:01:32 GMT",
"version": "v2"
}
] |
2023-10-19
|
[
[
"Zhang",
"He-Xu",
""
],
[
"Ishida",
"Hiroyuki",
""
],
[
"Matsuzaki",
"Shinya",
""
]
] |
The small field inflation (SFI) of Coleman-Weinberg (CW) type suffers from precise tuning of the initial inflaton field value to be away from the true vacuum one. We propose a dynamical trapping mechanism to solve this problem: an ultra-supercooling caused by an almost scale-invariant CW potential traps the inflaton at the false vacuum, far away from the true vacuum dominantly created by the quantum scale anomaly, and allows the inflaton to dynamically start the slow-roll down due to a classical explicit-scale breaking effect. To be concrete, we employ a successful CW-SFI model and show that the proposed mechanism works consistently with the observed bounds on the inflation parameters. The proposed new mechanism thus provides new insights for developing small field inflation models.
|
hep-ph/9401321
|
Hatsuda
|
T. Hatsuda
|
QCD and Quark/Hadron Matter
|
LaTeX 9 pages (with 7 figures), UTHEP-271 (figures will be mailed on
request.)
| null | null | null |
hep-ph nucl-th
| null |
A brief review on the recent theoretical progress in hot/dense QCD is given.
Special emphasis is put on the non-perturbative aspects of QCD plasma and the
modification of hadron proporties near the critical temperature of chiral
transition.
|
[
{
"created": "Tue, 25 Jan 1994 08:15:50 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Hatsuda",
"T.",
""
]
] |
A brief review on the recent theoretical progress in hot/dense QCD is given. Special emphasis is put on the non-perturbative aspects of QCD plasma and the modification of hadron proporties near the critical temperature of chiral transition.
|
0711.2931
|
Francesco Knechtli
|
F. Knechtli, N. Irges and M. Luz
|
New Higgs mechanism from the lattice
|
7 pages, 5 figures. Presented at International Europhysics Conference
on High Energy Physics (EPS-HEP2007), Manchester, England, 19-25 Jul 2007
|
J.Phys.Conf.Ser.110:102006,2008
|
10.1088/1742-6596/110/10/102006
|
WUB/07-10
|
hep-ph hep-lat
| null |
Spontaneous symmetry breaking has been observed in lattice simulations of
five-dimensional gauge theories on an orbifold. This effect is reproduced by
perturbation theory if it is modified to account for a finite cut-off. We
present a comparison of lattice and analytic results for bulk gauge group
SU(2).
|
[
{
"created": "Mon, 19 Nov 2007 13:51:17 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Knechtli",
"F.",
""
],
[
"Irges",
"N.",
""
],
[
"Luz",
"M.",
""
]
] |
Spontaneous symmetry breaking has been observed in lattice simulations of five-dimensional gauge theories on an orbifold. This effect is reproduced by perturbation theory if it is modified to account for a finite cut-off. We present a comparison of lattice and analytic results for bulk gauge group SU(2).
|
hep-ph/0011373
|
Konstantin Chetyrkin
|
J.J. van der Bij, K.G. Chetyrkin, M. Faisst, G. Jikia and T.
Seidensticker
|
Three-Loop Leading Top Mass Contributions to the rho Parameter
|
10 pages, 2 figures, Latex. v2: two minor corrections in the
references. Accepted for publication in Phys. lett. B. The complete paper is
also available via the www at
http://www-ttp.physik.uni-karlsruhe.de/Preprints/
|
Phys.Lett. B498 (2001) 156-162
|
10.1016/S0370-2693(01)00002-8
|
Freiburg-THEP 00/16, TTP 00--26
|
hep-ph
| null |
We present analytical results for the leading contributions of the top quark
to the electroweak rho parameter at order GF^3 Mt^6 and GF^2 Mt^4 alpha_s. The
Higgs boson and the gauge bosons are taken to be massless in this limit. The
correction of order GF^3 Mt^6 is found to be sizeable in comparison to the the
leading two-loop GF^2 Mt^4 correction, however it is much smaller than the
subleading GF^2 Mt^2 MZ^2 correction.
|
[
{
"created": "Wed, 29 Nov 2000 19:08:29 GMT",
"version": "v1"
},
{
"created": "Tue, 19 Dec 2000 09:05:39 GMT",
"version": "v2"
}
] |
2009-10-31
|
[
[
"van der Bij",
"J. J.",
""
],
[
"Chetyrkin",
"K. G.",
""
],
[
"Faisst",
"M.",
""
],
[
"Jikia",
"G.",
""
],
[
"Seidensticker",
"T.",
""
]
] |
We present analytical results for the leading contributions of the top quark to the electroweak rho parameter at order GF^3 Mt^6 and GF^2 Mt^4 alpha_s. The Higgs boson and the gauge bosons are taken to be massless in this limit. The correction of order GF^3 Mt^6 is found to be sizeable in comparison to the the leading two-loop GF^2 Mt^4 correction, however it is much smaller than the subleading GF^2 Mt^2 MZ^2 correction.
|
2207.03862
|
Pramod Sharma
|
Pramod Sharma, Ambresh Shivaji
|
Probing non-standard $HVV (V=W, Z)$ couplings in single Higgs production
at future electron-proton collider
|
21 pages, 9 figures, 4 tables
| null | null | null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The couplings of the Higgs boson ($H$) with massive gauge bosons of weak
interaction ($V= W, Z$), can be probed in single Higgs boson production at the
proposed future Large Hadron-Electron Collider (LHeC). In the collision of an
electron with a proton, single Higgs production takes place via so-called
charged-current ($e^-p \to \nu_e H j$) and neutral-current ($e^-p \to e^-H j$)
processes. We explore the potential of the azimuthal angle correlation between
the forward jet and scattered neutrino or electron in probing the non-standard
$HVV$ couplings at the collider center-of-mass energy of $\sqrt{s} \approx
1.3$~TeV. We choose the most general modifications (of $CP$-even and $CP$-odd
nature) to these couplings due to new physics effects beyond the standard
model. We derive exclusion limits on new physics parameters of $HVV$ couplings
as a function of integrated luminosity at $95\%$ C.L. using the azimuthal
angular correlations in charged- and neutral-current processes. We find that
using 1000 $fb^{-1}$ data, the standard model-like new physics parameters in
$HWW$ and $HZZ$ couplings can be constrained with accuracies of $4\%$ and
$15\%$, respectively. The least constrained $CP$-even parameters of $HWW$
coupling can be as large as 0.04, while those of $HZZ$ coupling can have values
around 0.31. Allowed values of $CP$-odd parameters in $HWW$ and $HZZ$ couplings
are found to be around 0.14 and 0.34, respectively. We also study changes in
the allowed values of non-trivial new physics parameters in the presence of
other parameters.
|
[
{
"created": "Fri, 8 Jul 2022 12:37:42 GMT",
"version": "v1"
}
] |
2022-07-11
|
[
[
"Sharma",
"Pramod",
""
],
[
"Shivaji",
"Ambresh",
""
]
] |
The couplings of the Higgs boson ($H$) with massive gauge bosons of weak interaction ($V= W, Z$), can be probed in single Higgs boson production at the proposed future Large Hadron-Electron Collider (LHeC). In the collision of an electron with a proton, single Higgs production takes place via so-called charged-current ($e^-p \to \nu_e H j$) and neutral-current ($e^-p \to e^-H j$) processes. We explore the potential of the azimuthal angle correlation between the forward jet and scattered neutrino or electron in probing the non-standard $HVV$ couplings at the collider center-of-mass energy of $\sqrt{s} \approx 1.3$~TeV. We choose the most general modifications (of $CP$-even and $CP$-odd nature) to these couplings due to new physics effects beyond the standard model. We derive exclusion limits on new physics parameters of $HVV$ couplings as a function of integrated luminosity at $95\%$ C.L. using the azimuthal angular correlations in charged- and neutral-current processes. We find that using 1000 $fb^{-1}$ data, the standard model-like new physics parameters in $HWW$ and $HZZ$ couplings can be constrained with accuracies of $4\%$ and $15\%$, respectively. The least constrained $CP$-even parameters of $HWW$ coupling can be as large as 0.04, while those of $HZZ$ coupling can have values around 0.31. Allowed values of $CP$-odd parameters in $HWW$ and $HZZ$ couplings are found to be around 0.14 and 0.34, respectively. We also study changes in the allowed values of non-trivial new physics parameters in the presence of other parameters.
|
2002.03021
|
Mikolaj Misiak
|
M. Misiak, A. Rehman, M. Steinhauser
|
On charm-mass dependent NNLO corrections to B -> Xs gamma
|
8 pages, 3 figures. Contribution to the proceedings of RADCOR 2019 -
14th International Symposium on Radiative Corrections: Applications of
Quantum Field Theory to Phenomenology, 9-13 September, 2019, Avignon, France.
The version at arXiv is updated with respect to the one at PoS
| null | null |
Report no. TTP19-046, P3H-19-052
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The inclusive radiative decay of the B meson is known to provide strong
constraints on many popular extensions of the Standard Model. Such constraints
crucially depend on precision of the Standard Model predictions. One of the
main contributions to the theoretical uncertainty is due to certain
Next-to-Next-to-Leading Order QCD corrections whose values at the physical
charm quark mass m_c have been estimated using interpolation between the m_c=0
and m_c >> m_b limits. A direct determination of such corrections at the
physical value of m_c requires calculating hundreds of two-scale four-loop
propagator diagrams with unitarity cuts. Applying the integration-by-parts
method, we express the corrections in terms of master integrals. Asymptotic
expansions of these integrals at m_c >> m_b serve as boundary conditions for
differential equations in z=m_c^2/m_b^2 that are being numerically solved.
Here, we present our final results for the diagrams involving massless and
massive fermion loops on the gluon lines. For the two-body cuts, we confirm the
analytical expressions and/or numerical fits that are already present in the
literature. In the four-body case, we make the correction complete by including
several diagrams that have previously been only estimated using interpolation
in m_c. We also report the status of the ongoing calculation of the remaining
diagrams where no closed fermion loops on the gluon lines are present.
|
[
{
"created": "Fri, 7 Feb 2020 21:34:13 GMT",
"version": "v1"
}
] |
2020-02-11
|
[
[
"Misiak",
"M.",
""
],
[
"Rehman",
"A.",
""
],
[
"Steinhauser",
"M.",
""
]
] |
The inclusive radiative decay of the B meson is known to provide strong constraints on many popular extensions of the Standard Model. Such constraints crucially depend on precision of the Standard Model predictions. One of the main contributions to the theoretical uncertainty is due to certain Next-to-Next-to-Leading Order QCD corrections whose values at the physical charm quark mass m_c have been estimated using interpolation between the m_c=0 and m_c >> m_b limits. A direct determination of such corrections at the physical value of m_c requires calculating hundreds of two-scale four-loop propagator diagrams with unitarity cuts. Applying the integration-by-parts method, we express the corrections in terms of master integrals. Asymptotic expansions of these integrals at m_c >> m_b serve as boundary conditions for differential equations in z=m_c^2/m_b^2 that are being numerically solved. Here, we present our final results for the diagrams involving massless and massive fermion loops on the gluon lines. For the two-body cuts, we confirm the analytical expressions and/or numerical fits that are already present in the literature. In the four-body case, we make the correction complete by including several diagrams that have previously been only estimated using interpolation in m_c. We also report the status of the ongoing calculation of the remaining diagrams where no closed fermion loops on the gluon lines are present.
|
1805.01393
|
Faisal Munir Bhutta
|
Aqsa Nasrullah, Faisal Munir Bhutta, M. Jamil Aslam
|
The $\Lambda_b \to \Lambda\ (\to p \pi^-)\mu^+\mu^-$ decay in the
$\text{RS}_{c}$ model
|
22 pages, 2 figures, references added, minor changes, matches
published version
|
J.Phys. G45 (2018) no.9, 095007
|
10.1088/1361-6471/aad53a
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study the four body decay $\Lambda_b \rightarrow \Lambda ( \rightarrow p
\pi^-) \mu^{+} \mu^{-}$ in the Randall-Sundrum model with custodial protection
$(\text{RS}_c)$. By considering the constraints coming from the direct searches
of the lightest Kaluza-Klein (KK) excitation of the gluon, electroweak
precision tests, the measurements of the Higgs signal strengths at the LHC and
from $\Delta F=2$ flavor observables, we perform a scan of the parameter space
of the $\text{RS}_c$ model and obtain the maximum allowed deviations of the
Wilson coefficients $\Delta C^{(\prime)}_{7,\; 9,\; 10}$ for different values
of the lightest KK gluon mass $M_{g^{(1)}}$. Later, their implications on the
observables such as differential branching fraction, longitudinal polarization
of the daughter baryon $\Lambda$, forward-backward asymmetry with respect to
leptonic, hadronic and combined lepton-hadron angles are discussed where we
present the analysis of these observables in different bins of di-muon
invariant mass squared $s\;(= q^2)$. It is observed that with the current
constraints the Wilson coefficients in $\text{RS}_c$ model show slight
deviations from their Standard Model values and hence can not accommodate the
discrepancies between the Standard Model calculations of various observables
and the LHCb measurements in $\Lambda_b$ decays.
|
[
{
"created": "Thu, 3 May 2018 16:04:04 GMT",
"version": "v1"
},
{
"created": "Sat, 17 Nov 2018 16:14:35 GMT",
"version": "v2"
}
] |
2018-11-22
|
[
[
"Nasrullah",
"Aqsa",
""
],
[
"Bhutta",
"Faisal Munir",
""
],
[
"Aslam",
"M. Jamil",
""
]
] |
We study the four body decay $\Lambda_b \rightarrow \Lambda ( \rightarrow p \pi^-) \mu^{+} \mu^{-}$ in the Randall-Sundrum model with custodial protection $(\text{RS}_c)$. By considering the constraints coming from the direct searches of the lightest Kaluza-Klein (KK) excitation of the gluon, electroweak precision tests, the measurements of the Higgs signal strengths at the LHC and from $\Delta F=2$ flavor observables, we perform a scan of the parameter space of the $\text{RS}_c$ model and obtain the maximum allowed deviations of the Wilson coefficients $\Delta C^{(\prime)}_{7,\; 9,\; 10}$ for different values of the lightest KK gluon mass $M_{g^{(1)}}$. Later, their implications on the observables such as differential branching fraction, longitudinal polarization of the daughter baryon $\Lambda$, forward-backward asymmetry with respect to leptonic, hadronic and combined lepton-hadron angles are discussed where we present the analysis of these observables in different bins of di-muon invariant mass squared $s\;(= q^2)$. It is observed that with the current constraints the Wilson coefficients in $\text{RS}_c$ model show slight deviations from their Standard Model values and hence can not accommodate the discrepancies between the Standard Model calculations of various observables and the LHCb measurements in $\Lambda_b$ decays.
|
1105.1423
|
Shuji Sasagawa
|
S. Sasagawa and H. Tanaka
|
Spectral Functions at finite temperature and chemical potential
|
8 pages
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
There are two formulations at non-zero chemical potential; one is the
formulation that a Lagrangian includes a chemical potential, the other is the
formulation that a Lagrangian does not include a chemical potential. The
existence of two formulations makes a calculation complicated. The results from
those formulations are not corresponding directly. This discrepancy exists in
the imaginary time formalism and the real time formalism. However, since this
is essentially caused by a difference of a frequency, the discrepancy vanishes
by modifying the Fourier transform. We show a calculational procedure with a
spectral function to understand this.
|
[
{
"created": "Sat, 7 May 2011 08:00:28 GMT",
"version": "v1"
}
] |
2011-05-10
|
[
[
"Sasagawa",
"S.",
""
],
[
"Tanaka",
"H.",
""
]
] |
There are two formulations at non-zero chemical potential; one is the formulation that a Lagrangian includes a chemical potential, the other is the formulation that a Lagrangian does not include a chemical potential. The existence of two formulations makes a calculation complicated. The results from those formulations are not corresponding directly. This discrepancy exists in the imaginary time formalism and the real time formalism. However, since this is essentially caused by a difference of a frequency, the discrepancy vanishes by modifying the Fourier transform. We show a calculational procedure with a spectral function to understand this.
|
1002.1967
|
Clifford Cheung
|
Clifford Cheung, Yasunori Nomura, and Jesse Thaler
|
Goldstini
|
14 pages, 7 figures; references added
| null |
10.1007/JHEP03(2010)073
|
UCB-PTH-09/04, MIT-CTP-4116
|
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Supersymmetric phenomenology has been largely bound to the hypothesis that
supersymmetry breaking originates from a single source. In this paper, we relax
this underlying assumption and consider a multiplicity of sectors which
independently break supersymmetry, thus yielding a corresponding multiplicity
of goldstini. While one linear combination of goldstini is eaten via the
super-Higgs mechanism, the orthogonal combinations remain in the spectrum as
physical degrees of freedom. Interestingly, supergravity effects induce a
universal tree-level mass for the goldstini which is exactly twice the
gravitino mass. Since visible sector fields can couple dominantly to the
goldstini rather than the gravitino, this framework allows for substantial
departures from conventional supersymmetric phenomenology. In fact, this even
occurs when a conventional mediation scheme is augmented by additional
supersymmetry breaking sectors which are fully sequestered. We discuss a number
of striking collider signatures, including various novel decay modes for the
lightest observable-sector supersymmetric particle, gravitinoless
gauge-mediated spectra, and events with multiple displaced vertices. We also
describe goldstini cosmology and the possibility of goldstini dark matter.
|
[
{
"created": "Tue, 9 Feb 2010 22:07:04 GMT",
"version": "v1"
},
{
"created": "Tue, 16 Feb 2010 22:17:21 GMT",
"version": "v2"
}
] |
2015-05-18
|
[
[
"Cheung",
"Clifford",
""
],
[
"Nomura",
"Yasunori",
""
],
[
"Thaler",
"Jesse",
""
]
] |
Supersymmetric phenomenology has been largely bound to the hypothesis that supersymmetry breaking originates from a single source. In this paper, we relax this underlying assumption and consider a multiplicity of sectors which independently break supersymmetry, thus yielding a corresponding multiplicity of goldstini. While one linear combination of goldstini is eaten via the super-Higgs mechanism, the orthogonal combinations remain in the spectrum as physical degrees of freedom. Interestingly, supergravity effects induce a universal tree-level mass for the goldstini which is exactly twice the gravitino mass. Since visible sector fields can couple dominantly to the goldstini rather than the gravitino, this framework allows for substantial departures from conventional supersymmetric phenomenology. In fact, this even occurs when a conventional mediation scheme is augmented by additional supersymmetry breaking sectors which are fully sequestered. We discuss a number of striking collider signatures, including various novel decay modes for the lightest observable-sector supersymmetric particle, gravitinoless gauge-mediated spectra, and events with multiple displaced vertices. We also describe goldstini cosmology and the possibility of goldstini dark matter.
|
hep-ph/9502418
|
Yuval Grossman
|
Yuval Grossman and Yosef Nir
|
Lepton Mass Matrix Models
|
25 pages, uses harvmac; no figures
|
Nucl.Phys. B448 (1995) 30-50
|
10.1016/0550-3213(95)00203-5
|
WIS-95/7/Mar-PH
|
hep-ph
| null |
The smallness and hierarchy in fermion parameters could be the result of
selection rules due to an Abelian horizontal symmetry broken by a small
parameter. When applied to the lepton sector, then for a large class of models,
a number of interesting order of magnitude relations arise: with $i<j$,
$m(\nu_i)/m(\nu_j)\sim\sin^2\theta_{ij}$;
$m(\ell^-_i)/m(\ell^-_j)\lsim\sin\theta_{ij}$; $m(\nu_i)/m(\nu_j)\gsim
m^2(\ell^-_i)/m^2(\ell^-_j)$; $m(\nu_e)\lsim m(\nu_\mu)\lsim m(\nu_\tau)$. The
relations between neutrino masses and mixings may become exact if the
horizontal symmetry together with holomorphy induce certain zero entries in the
lepton mass matrices. A full high energy theory is likely to include scalars
with flavor changing couplings and heavy leptons in vector representations;
however, the masses of these particles are too heavy to be directly observed in
experiment. Indirect evidence for the horizontal symmetry may arise from other
sectors of the theory: non-degenerate sleptons are allowed as the symmetry
aligns lepton and slepton mass matrices; light leptoquarks are allowed as the
symmetry can make their couplings diagonal and chiral.
|
[
{
"created": "Wed, 1 Mar 1995 06:45:59 GMT",
"version": "v1"
}
] |
2016-09-01
|
[
[
"Grossman",
"Yuval",
""
],
[
"Nir",
"Yosef",
""
]
] |
The smallness and hierarchy in fermion parameters could be the result of selection rules due to an Abelian horizontal symmetry broken by a small parameter. When applied to the lepton sector, then for a large class of models, a number of interesting order of magnitude relations arise: with $i<j$, $m(\nu_i)/m(\nu_j)\sim\sin^2\theta_{ij}$; $m(\ell^-_i)/m(\ell^-_j)\lsim\sin\theta_{ij}$; $m(\nu_i)/m(\nu_j)\gsim m^2(\ell^-_i)/m^2(\ell^-_j)$; $m(\nu_e)\lsim m(\nu_\mu)\lsim m(\nu_\tau)$. The relations between neutrino masses and mixings may become exact if the horizontal symmetry together with holomorphy induce certain zero entries in the lepton mass matrices. A full high energy theory is likely to include scalars with flavor changing couplings and heavy leptons in vector representations; however, the masses of these particles are too heavy to be directly observed in experiment. Indirect evidence for the horizontal symmetry may arise from other sectors of the theory: non-degenerate sleptons are allowed as the symmetry aligns lepton and slepton mass matrices; light leptoquarks are allowed as the symmetry can make their couplings diagonal and chiral.
|
1508.00327
|
Masato Yamanaka
|
Masato Yamanaka
|
Way to crosscheck $\mu$-$e$ conversion in the case of no signals of $\mu
\to e \gamma$ and $\mu \to 3e$
|
Proceedings of Flavor Physics \& CP Violation 2015 (FPCP 2015), 25-29
May 2015, Nagoya, Japan. arXiv admin note: substantial text overlap with
arXiv:1410.0512
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider the case that $\mu$-$e$ conversion signal is discovered but other
charged lepton flavor violating (cLFV) processes will never be found. In such a
case, we need other approaches to confirm the $\mu$-$e$ conversion and its
underlying physics without conventional cLFV searches. We study R-parity
violating (RPV) SUSY models as a benchmark. We briefly review that our
interesting case is realized in RPV SUSY models with reasonable settings
according to current theoretical/experimental status. We focus on the exotic
collider signatures at the LHC ($pp \to \mu^- e^+$ and $pp \to jj$) as the
other approaches. We show the correlations between the branching ratio of
$\mu$-$e$ conversion process and cross sections of these processes. It is first
time that the correlations are graphically shown. We exhibit the RPV parameter
dependence of the branching ratio and the cross sections, and discuss the
feasibility to determine the parameters.
|
[
{
"created": "Mon, 3 Aug 2015 07:08:26 GMT",
"version": "v1"
}
] |
2015-08-04
|
[
[
"Yamanaka",
"Masato",
""
]
] |
We consider the case that $\mu$-$e$ conversion signal is discovered but other charged lepton flavor violating (cLFV) processes will never be found. In such a case, we need other approaches to confirm the $\mu$-$e$ conversion and its underlying physics without conventional cLFV searches. We study R-parity violating (RPV) SUSY models as a benchmark. We briefly review that our interesting case is realized in RPV SUSY models with reasonable settings according to current theoretical/experimental status. We focus on the exotic collider signatures at the LHC ($pp \to \mu^- e^+$ and $pp \to jj$) as the other approaches. We show the correlations between the branching ratio of $\mu$-$e$ conversion process and cross sections of these processes. It is first time that the correlations are graphically shown. We exhibit the RPV parameter dependence of the branching ratio and the cross sections, and discuss the feasibility to determine the parameters.
|
1505.04155
|
Patryk Kubiczek
|
Patryk Kubiczek, Stanislaw D. Glazek
|
Manifestation of proton structure in the initial-state anisotropies in
high-energy proton-proton collisions
|
15 pages, 7 figures, submitted to Lith. J. Phys, corrected plots
|
Lith. J. Phys. 55, 155 (2015)
|
10.3952/physics.v55i3.3144
| null |
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Ridge-like correlations in high-energy proton-proton collisions reported by
the CMS collaboration suggest a collective flow that resembles the one in
heavy-ion collisions. If the hydrodynamic description is valid then the effect
results from the initial anisotropy of the colliding matter which depends on
the structure of protons. Following recent theoretical developments, we propose
several phenomenological models of the proton structure and calculate the
anisotropy coefficients using the Monte Carlo Glauber model. Our estimates
suggest that the event multiplicity dependence allows one to discriminate
between different proton models.
|
[
{
"created": "Fri, 15 May 2015 18:51:48 GMT",
"version": "v1"
},
{
"created": "Mon, 22 Jun 2015 10:14:28 GMT",
"version": "v2"
},
{
"created": "Tue, 14 Jul 2015 19:55:00 GMT",
"version": "v3"
},
{
"created": "Fri, 9 Oct 2015 09:47:07 GMT",
"version": "v4"
}
] |
2015-12-01
|
[
[
"Kubiczek",
"Patryk",
""
],
[
"Glazek",
"Stanislaw D.",
""
]
] |
Ridge-like correlations in high-energy proton-proton collisions reported by the CMS collaboration suggest a collective flow that resembles the one in heavy-ion collisions. If the hydrodynamic description is valid then the effect results from the initial anisotropy of the colliding matter which depends on the structure of protons. Following recent theoretical developments, we propose several phenomenological models of the proton structure and calculate the anisotropy coefficients using the Monte Carlo Glauber model. Our estimates suggest that the event multiplicity dependence allows one to discriminate between different proton models.
|
1010.1912
|
Yadong Yang
|
Xing-Bo Yuan, Yang Hao, Ya-Dong Yang
|
B -> Xs\gamma constraints on the top quark anomalous t-> c\gamma
coupling
|
15 pages, 5 figures. Revised. To appear in PRD
|
Phys.Rev.D83:013004,2011
|
10.1103/PhysRevD.83.013004
| null |
hep-ph hep-ex
|
http://creativecommons.org/licenses/by/3.0/
|
Observation of top quark flavor changing neutral process $t\to c +\gamma$ at
the LHC would be the signal of physics beyond the Standard Model. If anomalous
$t\to c\gamma$ coupling exists, it will affect the precisely measured
$\mathcal{B}(\bar{B} \to X_s \gamma)$. In this paper, we study the effects of a
dimension 5 anomalous $ tc \gamma$ operator in $\bar{B} \to X_s \gamma$ decay
to derive constraints on its possible strength. It is found that, for real
anomalous $t\to c\gamma$ coupling $\kappa_{\rm{tcR}}^\gamma$, the constraints
correspond to the upper bounds $\mathcal B (t \to c + \gamma)<6.54 \times
10^{-5}$ (for $\kappa_{\rm{tcR}}^\gamma>0$) and $\mathcal B (t \to c +
\gamma)<8.52 \times 10^{-5}$ (for $\kappa_{\rm{tcR}}^\gamma<0$), respectively,
which are about the same order as the $5\sigma$ discovery potential of ATLAS
($9.4\times 10^{-5}$) and slightly lower than that of CMS ($4.1\times 10^{-4}$)
with $10 \ \rm{fb}^{-1}$ integrated luminosity operating at $\sqrt{s} =14$ TeV.
|
[
{
"created": "Sun, 10 Oct 2010 11:40:44 GMT",
"version": "v1"
},
{
"created": "Mon, 18 Oct 2010 11:36:08 GMT",
"version": "v2"
},
{
"created": "Fri, 19 Nov 2010 09:08:49 GMT",
"version": "v3"
},
{
"created": "Wed, 12 Jan 2011 08:37:43 GMT",
"version": "v4"
}
] |
2011-02-01
|
[
[
"Yuan",
"Xing-Bo",
""
],
[
"Hao",
"Yang",
""
],
[
"Yang",
"Ya-Dong",
""
]
] |
Observation of top quark flavor changing neutral process $t\to c +\gamma$ at the LHC would be the signal of physics beyond the Standard Model. If anomalous $t\to c\gamma$ coupling exists, it will affect the precisely measured $\mathcal{B}(\bar{B} \to X_s \gamma)$. In this paper, we study the effects of a dimension 5 anomalous $ tc \gamma$ operator in $\bar{B} \to X_s \gamma$ decay to derive constraints on its possible strength. It is found that, for real anomalous $t\to c\gamma$ coupling $\kappa_{\rm{tcR}}^\gamma$, the constraints correspond to the upper bounds $\mathcal B (t \to c + \gamma)<6.54 \times 10^{-5}$ (for $\kappa_{\rm{tcR}}^\gamma>0$) and $\mathcal B (t \to c + \gamma)<8.52 \times 10^{-5}$ (for $\kappa_{\rm{tcR}}^\gamma<0$), respectively, which are about the same order as the $5\sigma$ discovery potential of ATLAS ($9.4\times 10^{-5}$) and slightly lower than that of CMS ($4.1\times 10^{-4}$) with $10 \ \rm{fb}^{-1}$ integrated luminosity operating at $\sqrt{s} =14$ TeV.
|
hep-ph/0403005
|
Michio Hashimoto
|
Michio Hashimoto (Pusan Natl. U.), Shinya Kanemura (Osaka U.)
|
New mechanism for the top-bottom mass hierarchy
|
5 pages, 3 figures, Version accepted for publication in Physical
Review D
|
Phys.Rev.D70:055006,2004; Erratum-ibid.D70:119901,2004
|
10.1103/PhysRevD.70.055006 10.1103/PhysRevD.70.119901
| null |
hep-ph hep-ex
| null |
We propose a mechanism to generate hierarchy between masses of the top and
bottom quarks without fine tuning of the Yukawa coupling constants in the
context of the two Higgs doublet model (THDM). In the THDM with a discrete
symmetry, there exists the vacuum where only the top quark receives the mass of
the order of the electroweak symmetry breaking scale $v(\simeq 246 GeV)$, while
the bottom quark remains massless. By introducing a small soft-breaking
parameter $m_3^2$ of the discrete symmetry, the bottom quark perturbatively
acquires a nonzero mass. We show a model in which the small $m_3^2 [\sim
v^2/(4\pi)^2]$ is generated by the dynamics above the cutoff scale of the THDM.
The ratio $\tan\beta$ of the two vacuum expectation values is necessarily very
large; i.e., $\tan \beta \sim m_t/m_b$. We also find a salient relation,
$1/\tan\beta \simeq m_3^2/m_H^2$, where $m_H$ is the mass of the extra CP-even
Higgs boson. Our scenario yields some specific features that can be tested in
future collider experiments.
|
[
{
"created": "Sat, 28 Feb 2004 08:23:05 GMT",
"version": "v1"
},
{
"created": "Fri, 23 Jul 2004 16:21:39 GMT",
"version": "v2"
}
] |
2014-11-17
|
[
[
"Hashimoto",
"Michio",
"",
"Pusan Natl. U."
],
[
"Kanemura",
"Shinya",
"",
"Osaka U."
]
] |
We propose a mechanism to generate hierarchy between masses of the top and bottom quarks without fine tuning of the Yukawa coupling constants in the context of the two Higgs doublet model (THDM). In the THDM with a discrete symmetry, there exists the vacuum where only the top quark receives the mass of the order of the electroweak symmetry breaking scale $v(\simeq 246 GeV)$, while the bottom quark remains massless. By introducing a small soft-breaking parameter $m_3^2$ of the discrete symmetry, the bottom quark perturbatively acquires a nonzero mass. We show a model in which the small $m_3^2 [\sim v^2/(4\pi)^2]$ is generated by the dynamics above the cutoff scale of the THDM. The ratio $\tan\beta$ of the two vacuum expectation values is necessarily very large; i.e., $\tan \beta \sim m_t/m_b$. We also find a salient relation, $1/\tan\beta \simeq m_3^2/m_H^2$, where $m_H$ is the mass of the extra CP-even Higgs boson. Our scenario yields some specific features that can be tested in future collider experiments.
|
hep-ph/0404177
|
Enrico Cattaruzza
|
E. Cattaruzza, A. Del Fabbro and D. Treleani
|
Heavy-Quark production in proton-nucleus collision at the LHC
|
12 pages, 6 figures, submitted to Phys.Rev.D
|
Phys.Rev.D70:034022,2004
|
10.1103/PhysRevD.70.034022
| null |
hep-ph
| null |
A sizable rate of events, with several pairs of heavy-quarks produced
contemporarily by multiple parton interactions, may be expected at very high
energies as a consequence of the large parton luminosities. The production
rates are enhanced in hadron-nucleus reactions, which may represent a
convenient tool to study the phenomenon. We compare the different contributions
to ccbar bbar pairs production due to single and double parton scatterings, in
collisions of protons with nuclei at the CERN-LHC.
|
[
{
"created": "Wed, 21 Apr 2004 15:00:43 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Cattaruzza",
"E.",
""
],
[
"Del Fabbro",
"A.",
""
],
[
"Treleani",
"D.",
""
]
] |
A sizable rate of events, with several pairs of heavy-quarks produced contemporarily by multiple parton interactions, may be expected at very high energies as a consequence of the large parton luminosities. The production rates are enhanced in hadron-nucleus reactions, which may represent a convenient tool to study the phenomenon. We compare the different contributions to ccbar bbar pairs production due to single and double parton scatterings, in collisions of protons with nuclei at the CERN-LHC.
|
2207.06600
|
Carlos Andres Escobar Ruiz
|
C. A. Escobar, A. Mart\'in-Ruiz, A. M. Escobar-Ruiz and Rom\'an
Linares
|
Testing the scalar sector of the Standard-Model Extension with neutron
gravity experiments
|
12 Pages, 5 Figures
| null | null | null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
In the present study we analyse, within the scalar sector of the
Standard-Model Extension (SME) framework, the influence of a spontaneous
Lorentz symmetry breaking on gravitational quantum states of ultracold
neutrons. The model is framed according to the laboratory conditions of the
recent high-sensitivity GRANIT and $q$Bounce experiments. The high-precision
data achieved in such experiments allow us to set bounds on the symmetry
breaking parameters of the model. The effective Hamiltonian governing the
neutron's motion along the axis of free fall is derived explicitly. It
describes a particle in a gravitational field with an effective gravitational
constant controlled non-trivially by the Lorentz-violating parameters. In
particular, using the exact wave functions and the energy spectrum, we evaluate
both the heights associated with the quantum states and the transition
frequencies between neighborhoring quantum states. By comparing our theoretical
results with those reported in the GRANIT and the $q$Bounce experiments, upper
bounds on the Lorentz-violating parameters are determined. We also consider for
the first time the gravity-induced interference pattern in a COW-type
experiment to test Lorenz-invariance. In this case, an upper bound for the
parameters is established as well.
|
[
{
"created": "Thu, 14 Jul 2022 01:39:03 GMT",
"version": "v1"
}
] |
2022-07-15
|
[
[
"Escobar",
"C. A.",
""
],
[
"Martín-Ruiz",
"A.",
""
],
[
"Escobar-Ruiz",
"A. M.",
""
],
[
"Linares",
"Román",
""
]
] |
In the present study we analyse, within the scalar sector of the Standard-Model Extension (SME) framework, the influence of a spontaneous Lorentz symmetry breaking on gravitational quantum states of ultracold neutrons. The model is framed according to the laboratory conditions of the recent high-sensitivity GRANIT and $q$Bounce experiments. The high-precision data achieved in such experiments allow us to set bounds on the symmetry breaking parameters of the model. The effective Hamiltonian governing the neutron's motion along the axis of free fall is derived explicitly. It describes a particle in a gravitational field with an effective gravitational constant controlled non-trivially by the Lorentz-violating parameters. In particular, using the exact wave functions and the energy spectrum, we evaluate both the heights associated with the quantum states and the transition frequencies between neighborhoring quantum states. By comparing our theoretical results with those reported in the GRANIT and the $q$Bounce experiments, upper bounds on the Lorentz-violating parameters are determined. We also consider for the first time the gravity-induced interference pattern in a COW-type experiment to test Lorenz-invariance. In this case, an upper bound for the parameters is established as well.
|
2101.03173
|
Gonzalo Alonso-\'Alvarez
|
Gonzalo Alonso-\'Alvarez, Fatih Ertas, Joerg Jaeckel, Felix
Kahlhoefer, and Lennert J. Thormaehlen
|
Leading Logs in QCD Axion Effective Field Theory
|
28 pages + appendices. v3: revised text, main results unchanged
| null |
10.1007/JHEP07(2021)059
|
TTK-21-02
|
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The axion is much lighter than all other degrees of freedom introduced by the
Peccei-Quinn mechanism to solve the strong CP problem. It is therefore natural
to use an effective field theory (EFT) to describe its interactions. Loop
processes calculated in the EFT may, however, explicitly depend on the
ultraviolet cutoff. In general the UV cutoff is not uniquely defined, but the
dimensionful couplings suggest to identify it with the Peccei-Quinn
symmetry-breaking scale. An example are $K \rightarrow \pi + a$ decays that
will soon be tested to improved precision in NA62 and KOTO and whose amplitude
is dominated by the term logarithmically dependent on the cutoff. In this
paper, we critically examine the adequacy of using such a naive EFT approach to
study loop processes by comparing EFT calculations with ones performed in
complete QCD axion models. In DFSZ models, for example, the cutoff is found to
be set by additional Higgs degrees of freedom and to therefore be much closer
to the electroweak scale than to the Peccei-Quinn scale. In fact, there are
non-trivial requirements on axion models where the cutoff scale of loop
processes is close to the Peccei-Quinn scale, such that the naive EFT result is
reproduced. This suggests that the existence of a suitable UV embedding may
impose restrictions on axion EFTs. We provide an explicit construction of a
model with suitable fermion couplings and find promising prospects for NA62 and
IAXO.
|
[
{
"created": "Fri, 8 Jan 2021 19:00:00 GMT",
"version": "v1"
},
{
"created": "Sat, 20 Feb 2021 14:31:16 GMT",
"version": "v2"
},
{
"created": "Fri, 25 Jun 2021 09:15:45 GMT",
"version": "v3"
}
] |
2021-07-28
|
[
[
"Alonso-Álvarez",
"Gonzalo",
""
],
[
"Ertas",
"Fatih",
""
],
[
"Jaeckel",
"Joerg",
""
],
[
"Kahlhoefer",
"Felix",
""
],
[
"Thormaehlen",
"Lennert J.",
""
]
] |
The axion is much lighter than all other degrees of freedom introduced by the Peccei-Quinn mechanism to solve the strong CP problem. It is therefore natural to use an effective field theory (EFT) to describe its interactions. Loop processes calculated in the EFT may, however, explicitly depend on the ultraviolet cutoff. In general the UV cutoff is not uniquely defined, but the dimensionful couplings suggest to identify it with the Peccei-Quinn symmetry-breaking scale. An example are $K \rightarrow \pi + a$ decays that will soon be tested to improved precision in NA62 and KOTO and whose amplitude is dominated by the term logarithmically dependent on the cutoff. In this paper, we critically examine the adequacy of using such a naive EFT approach to study loop processes by comparing EFT calculations with ones performed in complete QCD axion models. In DFSZ models, for example, the cutoff is found to be set by additional Higgs degrees of freedom and to therefore be much closer to the electroweak scale than to the Peccei-Quinn scale. In fact, there are non-trivial requirements on axion models where the cutoff scale of loop processes is close to the Peccei-Quinn scale, such that the naive EFT result is reproduced. This suggests that the existence of a suitable UV embedding may impose restrictions on axion EFTs. We provide an explicit construction of a model with suitable fermion couplings and find promising prospects for NA62 and IAXO.
|
hep-ph/9703442
|
Mikolaj Misiak
|
Mikolaj Misiak, Stefan Pokorski and Janusz Rosiek
|
Supersymmetry and FCNC effects
|
45 pages, 19 figures, uses epsfig.sty, (axodraw.sty included) To
appear in the Review Volume ``Heavy Flavours II'', eds. A.J. Buras and M.
Lindner, Advanced Series on Directions in High Energy Physics, World
Scientific Publishing Co., Singapore. Revision made on November 19, 1997
amounts to including "note added" concerning bounds on delta_LR from
charginos, and a few correlated minor changes. Misprint in eq. (A.5)
corrected
| null |
10.1142/9789812812667_0012
|
IFT 3/97
|
hep-ph
| null |
We consider Flavour Changing Neutral Current processes in the framework of
the supersymmetric extension of the Standard Model. FCNC constraints on the
structure of sfermion mass matrices are reviewed. Furthermore, we analyze
supersymmetric contributions to FCNC transitions which remain in the limit of
flavour-conserving sfermion mass matrices. Implications of the FCNC constraints
on the structure of sfermion mass matrices for SUSY breaking and sfermion mass
generation are discussed. We conclude that the supersymmetric flavour problem
is intriguing but perhaps not as severe as it is commonly believed.
|
[
{
"created": "Thu, 27 Mar 1997 15:22:35 GMT",
"version": "v1"
},
{
"created": "Wed, 19 Nov 1997 20:16:25 GMT",
"version": "v2"
}
] |
2016-11-03
|
[
[
"Misiak",
"Mikolaj",
""
],
[
"Pokorski",
"Stefan",
""
],
[
"Rosiek",
"Janusz",
""
]
] |
We consider Flavour Changing Neutral Current processes in the framework of the supersymmetric extension of the Standard Model. FCNC constraints on the structure of sfermion mass matrices are reviewed. Furthermore, we analyze supersymmetric contributions to FCNC transitions which remain in the limit of flavour-conserving sfermion mass matrices. Implications of the FCNC constraints on the structure of sfermion mass matrices for SUSY breaking and sfermion mass generation are discussed. We conclude that the supersymmetric flavour problem is intriguing but perhaps not as severe as it is commonly believed.
|
hep-ph/9808476
|
Guenter Sigl
|
Georg Raffelt (MPI, Muenchen, Germany), Guenter Sigl (Univ. of
Chicago, USA)
|
Numerical Toy-Model Calculation of the Nucleon Spin Autocorrelation
Function in a Supernova Core
|
14 latex pages in two-column format, 15 postscript figures included,
uses revtex.sty and epsf.sty. Submitted to Physical Review D
|
Phys.Rev. D60 (1999) 023001
|
10.1103/PhysRevD.60.023001
| null |
hep-ph astro-ph
| null |
We develop a simple model for the evolution of a nucleon spin in a hot and
dense nuclear medium. A given nucleon is limited to one-dimensional motion in a
distribution of external, spin-dependent scattering potentials. We calculate
the nucleon spin autocorrelation function numerically for a variety of
potential densities and distributions which are meant to bracket realistic
conditions in a supernova core. For all plausible configurations the width of
the spin-density structure function is found to be less than the temperature.
This is in contrast with a naive perturbative calculation based on the one-pion
exchange potential which overestimates the width and thus suggests a large
suppression of the neutrino opacities by nucleon spin fluctuations. Our results
suggest that it may be justified to neglect the collisional broadening of the
spin-density structure function for the purpose of estimating the neutrino
opacities in the deep inner core of a supernova. On the other hand, we find no
indication that processes such as axion or neutrino pair emission, which depend
on nucleon spin fluctuations, are substantially suppressed beyond the
multiple-scattering effect already discussed in the literature. Aside from
these practical conclusions, our model reveals a number of interesting and
unexpected insights. For example, the spin-relaxation rate saturates with
increasing potential strength only if bound states are not allowed to form by
including a repulsive core. There is no saturation with increasing density of
scattering potentials until localized eigenstates of energy begin to form.
|
[
{
"created": "Sun, 30 Aug 1998 19:25:06 GMT",
"version": "v1"
}
] |
2009-10-31
|
[
[
"Raffelt",
"Georg",
"",
"MPI, Muenchen, Germany"
],
[
"Sigl",
"Guenter",
"",
"Univ. of\n Chicago, USA"
]
] |
We develop a simple model for the evolution of a nucleon spin in a hot and dense nuclear medium. A given nucleon is limited to one-dimensional motion in a distribution of external, spin-dependent scattering potentials. We calculate the nucleon spin autocorrelation function numerically for a variety of potential densities and distributions which are meant to bracket realistic conditions in a supernova core. For all plausible configurations the width of the spin-density structure function is found to be less than the temperature. This is in contrast with a naive perturbative calculation based on the one-pion exchange potential which overestimates the width and thus suggests a large suppression of the neutrino opacities by nucleon spin fluctuations. Our results suggest that it may be justified to neglect the collisional broadening of the spin-density structure function for the purpose of estimating the neutrino opacities in the deep inner core of a supernova. On the other hand, we find no indication that processes such as axion or neutrino pair emission, which depend on nucleon spin fluctuations, are substantially suppressed beyond the multiple-scattering effect already discussed in the literature. Aside from these practical conclusions, our model reveals a number of interesting and unexpected insights. For example, the spin-relaxation rate saturates with increasing potential strength only if bound states are not allowed to form by including a repulsive core. There is no saturation with increasing density of scattering potentials until localized eigenstates of energy begin to form.
|
hep-ph/9608454
|
Vittorio Del Duca
|
Vittorio Del Duca
|
Theory of Double Hard Diffraction
|
LaTeX, 11 pages (including 2 figures). To appear in the Proceedings
of the XI Topical Workshop on P-Pbar Collider Physics, Abano Terme, Italy,
May 1996
| null | null |
EDINBURGH 96/11
|
hep-ph
| null |
In this review talk I consider the physics of rapidity gaps between two jets
at hadron colliders, as a preliminary investigation toward understanding the
production of a Higgs boson via weak boson fusion at the LHC.
|
[
{
"created": "Tue, 27 Aug 1996 17:50:11 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Del Duca",
"Vittorio",
""
]
] |
In this review talk I consider the physics of rapidity gaps between two jets at hadron colliders, as a preliminary investigation toward understanding the production of a Higgs boson via weak boson fusion at the LHC.
|
1510.02080
|
Igor Altsybeev
|
Igor Altsybeev, Grigory Feofilov, Ewen Lawson Gillies
|
Forward-backward correlations with strange particles in PYTHIA
|
To be published in Proceedings of Strangeness in Quark Matter
Conference, SQM 2015 Dubna
| null |
10.1088/1742-6596/668/1/012034
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We present studies of strange particle yields and correlations in $pp$
collisions in the PYTHIA8 event generator by studying forward-backward
correlations. Several key processes that give rise to these correlative effects
are identified and manipulated to probe the fundamental properties of strange
particle emitting sources. The sensitivity of strange particle production and
correlations to PYTHIA's multiparton interaction, color reconnection, and
explicit strangeness suppression are shown.
|
[
{
"created": "Wed, 7 Oct 2015 19:54:20 GMT",
"version": "v1"
}
] |
2016-02-17
|
[
[
"Altsybeev",
"Igor",
""
],
[
"Feofilov",
"Grigory",
""
],
[
"Gillies",
"Ewen Lawson",
""
]
] |
We present studies of strange particle yields and correlations in $pp$ collisions in the PYTHIA8 event generator by studying forward-backward correlations. Several key processes that give rise to these correlative effects are identified and manipulated to probe the fundamental properties of strange particle emitting sources. The sensitivity of strange particle production and correlations to PYTHIA's multiparton interaction, color reconnection, and explicit strangeness suppression are shown.
|
hep-ph/9501381
| null |
J. Kodaira (Dept. of Physics, Hiroshima Univ.)
|
PERTURBATIVE QCD AND NUCLEON STRUCTURE FUNCTIONS.
|
31pp, Latex, psfig.sty, 3 figures are included as an uuencoded
commpressed ps file. Invited talk at the YITP Workshop on ``From Hadronic
Matter to Quark Matter: Evolving View of Hadronic Matter" YITP, Kyoto Japan,
October 1994
|
Prog.Theor.Phys.Suppl.120:37-56,1995
|
10.1143/PTPS.120.37
|
HUPD-9504
|
hep-ph
| null |
We review the basic aspects of the perturbative QCD based on the operator
product expansion to analyze the nucleon structure functions in a pedagogical
way. We explain the non-trivial relation between the QCD results and the parton
model especially to understand the polarized nucleon structure functions which
deserve much attentions in recent years.
|
[
{
"created": "Thu, 26 Jan 1995 02:14:39 GMT",
"version": "v1"
}
] |
2016-09-01
|
[
[
"Kodaira",
"J.",
"",
"Dept. of Physics, Hiroshima Univ."
]
] |
We review the basic aspects of the perturbative QCD based on the operator product expansion to analyze the nucleon structure functions in a pedagogical way. We explain the non-trivial relation between the QCD results and the parton model especially to understand the polarized nucleon structure functions which deserve much attentions in recent years.
|
1012.5242
|
Chihiro Sasaki
|
Chihiro Sasaki
|
Chiral thermodynamics of dense hadronic matter
|
8 pages, 2 figures, to appear in the proceedings of 6th International
Workshop on Critical Point and Onset of Deconfinement (CPOD), 23-29 August
2010 at Joint Institute for Nuclear Research, Dubna, Russia
| null |
10.1134/S1063778812050225
| null |
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We discuss phases of hot and dense hadronic matter using chiral Lagrangians.
A two-flavored parity doublet model constrained by the nuclear matter ground
state predicts chiral symmetry restoration. The model thermodynamics is shown
within the mean field approximation. A field-theoretical constraint on possible
phases from the anomaly matching is also discussed.
|
[
{
"created": "Thu, 23 Dec 2010 16:14:13 GMT",
"version": "v1"
}
] |
2015-05-20
|
[
[
"Sasaki",
"Chihiro",
""
]
] |
We discuss phases of hot and dense hadronic matter using chiral Lagrangians. A two-flavored parity doublet model constrained by the nuclear matter ground state predicts chiral symmetry restoration. The model thermodynamics is shown within the mean field approximation. A field-theoretical constraint on possible phases from the anomaly matching is also discussed.
|
1801.08611
|
Scott A. Yost
|
Stanislaw Jadach, Scott Yost
|
QED Interference in Charge Asymmetry Near the Z Resonance at Future
Electron-Positron Colliders
|
51 pages, 46 figures. Version 3 is updated to agree with the final
version to appear in Phys. Rev. D. There are minor corrections to some
equations
|
Phys. Rev. D 100, 013002 (2019)
|
10.1103/PhysRevD.100.013002
|
IFJPAN-IV-2017-11
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The measurement of the charge asymmetry $A_{FB}(e^-e^+\to \mu^-\mu^+)$ will
play an important role at the high-luminosity circular electron-positron
collider FCCee considered for construction at CERN. In particular, near the Z
resonance, $\sqrt{s} \simeq M_Z \pm 3.5$ GeV, $A_{FB}$ will provide a very
precise value of the pure electromagnetic coupling constant
$\alpha_{QED}(M_Z)$, which is vitally important for overall tests of the
Standard Model. For this purpose, $A_{FB}$ will be measured at the FCCee with
an experimental error better than $\delta A_{FB} \simeq 3\cdot 10^{-5},$ at
least a factor 100 more precisely than at past LEP experiments! The important
question is whether the effect of interference between photon emission in the
initial and final state can be removed from the $A_{FB}$ data at the same
precision level using perturbative QED calculations. A first quantitative study
of this problem is presented here, with the help of the KKMC program and a
newly developed calculation based on soft photon resummation, matched with NLO
and NNLO fixed-order calculations. It is concluded that a factor of 10
improvement with respect to the LEP era is obtained. We also present a clear
indication that reducing the uncertainty of charge asymmetry near the Z peak
due to IFI down to $\delta A_{FB} \simeq 3\cdot 10^{-5}$, i.e. the expected
experimental precision at FCCee, is feasible.
|
[
{
"created": "Thu, 25 Jan 2018 21:54:43 GMT",
"version": "v1"
},
{
"created": "Fri, 30 Nov 2018 00:36:48 GMT",
"version": "v2"
},
{
"created": "Fri, 7 Jun 2019 11:42:21 GMT",
"version": "v3"
},
{
"created": "Tue, 16 Jul 2019 22:17:18 GMT",
"version": "v4"
}
] |
2019-07-24
|
[
[
"Jadach",
"Stanislaw",
""
],
[
"Yost",
"Scott",
""
]
] |
The measurement of the charge asymmetry $A_{FB}(e^-e^+\to \mu^-\mu^+)$ will play an important role at the high-luminosity circular electron-positron collider FCCee considered for construction at CERN. In particular, near the Z resonance, $\sqrt{s} \simeq M_Z \pm 3.5$ GeV, $A_{FB}$ will provide a very precise value of the pure electromagnetic coupling constant $\alpha_{QED}(M_Z)$, which is vitally important for overall tests of the Standard Model. For this purpose, $A_{FB}$ will be measured at the FCCee with an experimental error better than $\delta A_{FB} \simeq 3\cdot 10^{-5},$ at least a factor 100 more precisely than at past LEP experiments! The important question is whether the effect of interference between photon emission in the initial and final state can be removed from the $A_{FB}$ data at the same precision level using perturbative QED calculations. A first quantitative study of this problem is presented here, with the help of the KKMC program and a newly developed calculation based on soft photon resummation, matched with NLO and NNLO fixed-order calculations. It is concluded that a factor of 10 improvement with respect to the LEP era is obtained. We also present a clear indication that reducing the uncertainty of charge asymmetry near the Z peak due to IFI down to $\delta A_{FB} \simeq 3\cdot 10^{-5}$, i.e. the expected experimental precision at FCCee, is feasible.
|
hep-ph/9911466
|
Yue-liang Wu
|
K.C. Chou (CAS), W. Palmer (OSU), E.A. Paschos (DOU) and Y.L. Wu (ITP)
|
Searching for Rephase-Invariant CP- and CPT-violating Observables in
Meson Decays
|
21 pages, no figures, revised version for more readable and
references added
|
Eur.Phys.J.C16:279-287,2000
|
10.1007/s100520050020
|
DO-TH-99-21, OHSTPY-HEP-T-99-026
|
hep-ph
| null |
We present a general model-independent and rephase-invariant formalism that
cleanly relates CP and CPT noninvariant observables to the fundamental
parameters. Different types of CP and CPT violations in the K^0-, B^0-, B_s^0-
and D^0-systems are explicitly defined. Their importance for interpreting
experimental measurements of CP and CPT violations is emphasized. In
particular, we show that the time-dependent measurements allow one to extract a
clean signature of CPT violation.
|
[
{
"created": "Wed, 24 Nov 1999 13:23:30 GMT",
"version": "v1"
},
{
"created": "Fri, 4 Feb 2000 03:25:07 GMT",
"version": "v2"
}
] |
2011-09-13
|
[
[
"Chou",
"K. C.",
"",
"CAS"
],
[
"Palmer",
"W.",
"",
"OSU"
],
[
"Paschos",
"E. A.",
"",
"DOU"
],
[
"Wu",
"Y. L.",
"",
"ITP"
]
] |
We present a general model-independent and rephase-invariant formalism that cleanly relates CP and CPT noninvariant observables to the fundamental parameters. Different types of CP and CPT violations in the K^0-, B^0-, B_s^0- and D^0-systems are explicitly defined. Their importance for interpreting experimental measurements of CP and CPT violations is emphasized. In particular, we show that the time-dependent measurements allow one to extract a clean signature of CPT violation.
|
hep-ph/9812370
|
Catherine Bourge
|
Michel Davier
|
Evaluation of $\alpha(M_{\rm Z}^2)$ and $(g-2)_\mu$
|
13 pages
|
Nucl.Phys.Proc.Suppl. 76 (1999) 327-338
|
10.1016/S0920-5632(99)00486-7
|
LAL 98-87
|
hep-ph
| null |
This talk summarizes the recent developments in the evaluation of the leading
order hadronic contributions to the running of the QED fine structure constant
$\alpha(s)$, at $s=M_{\rm Z}^2$, and to the anomalous magnetic moment of the
muon $(g-2)_\mu$. The accuracy of the theoretical prediction of these
observables is limited by the uncertainties on the hadronic contributions.
Significant improvement has been achieved in a series of new analyses which is
presented historically in three steps: (I), use of $\tau$ spectral functions in
addition to $e^+e^-$ cross sections, (II), extended use of perturbative QCD and
(III), application of QCD sum rule techniques. The most precise values obtained
are: $\Delta\alpha_{\rm had}(M_{\rm Z}^2)$, $=(276.3\pm1.6)\times10^{-4}$,
yielding $\alpha^{-1}(M_{\rm Z}^2)=128.933\pm0.021$, and $a_\mu^{\rm
had}=(692.4\pm6.2)\times 10^{-10}$ with which one finds for the complete
Standard Model prediction $a_\mu^{\rm SM}=(11 659 159.6\pm6.7)\times10^{-10}$.
For the electron $(g-2)_e$, the hadronic contribution is $a_e^{\rm
had}=(187.5\pm1.8)\times 10^{-14}$.
|
[
{
"created": "Tue, 15 Dec 1998 15:32:58 GMT",
"version": "v1"
},
{
"created": "Thu, 17 Dec 1998 10:01:31 GMT",
"version": "v2"
}
] |
2009-10-31
|
[
[
"Davier",
"Michel",
""
]
] |
This talk summarizes the recent developments in the evaluation of the leading order hadronic contributions to the running of the QED fine structure constant $\alpha(s)$, at $s=M_{\rm Z}^2$, and to the anomalous magnetic moment of the muon $(g-2)_\mu$. The accuracy of the theoretical prediction of these observables is limited by the uncertainties on the hadronic contributions. Significant improvement has been achieved in a series of new analyses which is presented historically in three steps: (I), use of $\tau$ spectral functions in addition to $e^+e^-$ cross sections, (II), extended use of perturbative QCD and (III), application of QCD sum rule techniques. The most precise values obtained are: $\Delta\alpha_{\rm had}(M_{\rm Z}^2)$, $=(276.3\pm1.6)\times10^{-4}$, yielding $\alpha^{-1}(M_{\rm Z}^2)=128.933\pm0.021$, and $a_\mu^{\rm had}=(692.4\pm6.2)\times 10^{-10}$ with which one finds for the complete Standard Model prediction $a_\mu^{\rm SM}=(11 659 159.6\pm6.7)\times10^{-10}$. For the electron $(g-2)_e$, the hadronic contribution is $a_e^{\rm had}=(187.5\pm1.8)\times 10^{-14}$.
|
hep-ph/0112134
|
Spanos Vassilis
|
A.B. Lahanas, D.V. Nanopoulos and V.C. Spanos
|
Combining Supersymmetric Dark Matter with Recent Accelerator Data
|
11 pages, 5 figures. Talk at COSMO-01 Workshop, Rovaniemi, Finland,
August 30 - September 4, 2001. Full quality figures can be obtained from
http://wwwhephy.oeaw.ac.at/u3w/s/spanos/www
| null | null | null |
hep-ph astro-ph gr-qc
| null |
In the framework of the Constrained Minimal Supersymmetric Standard Model we
discuss the impact of the recent experimental information, especially from the
E821 Brookhaven experiment on $g_{\mu}-2$ along with the light Higgs boson mass
bound from LEP, in delineating regions of the parameters which are consistent
with cosmological data. The effect of these to the Dark Matter direct searches
is also discussed.
|
[
{
"created": "Mon, 10 Dec 2001 12:53:52 GMT",
"version": "v1"
},
{
"created": "Thu, 13 Dec 2001 10:25:03 GMT",
"version": "v2"
}
] |
2007-05-23
|
[
[
"Lahanas",
"A. B.",
""
],
[
"Nanopoulos",
"D. V.",
""
],
[
"Spanos",
"V. C.",
""
]
] |
In the framework of the Constrained Minimal Supersymmetric Standard Model we discuss the impact of the recent experimental information, especially from the E821 Brookhaven experiment on $g_{\mu}-2$ along with the light Higgs boson mass bound from LEP, in delineating regions of the parameters which are consistent with cosmological data. The effect of these to the Dark Matter direct searches is also discussed.
|
1510.04906
|
Gergely G\'abor Barnaf\"oldi
|
P\'eter P\'osfay, Gergely G\'abor Barnaf\"oldi, Antal Jakov\'ac
|
FRG Approach to Nuclear Matter at Extreme Conditions
|
6 pages, 3 figures
| null | null | null |
hep-ph astro-ph.HE nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Functional renormalization group (FRG) is an exact method for taking into
account the effect of quantum fluctuations in the effective action of the
system. The FRG method applied to effective theories of nuclear matter yields
equation of state which incorporates quantum fluctuations of the fields. Using
the local potential approximation (LPA) the equation of state for Walecka-type
models of nuclear matter under extreme conditions could be determined. These
models can be tested by solving the corresponding Tolman--Oppenheimer--Volkov
(TOV) equations and investigating the properties (mass and radius) of the
corresponding compact star models. Here, we present the first steps on this
way, we obtained a Maxwell construction within the FRG-based framework using a
Walecka-type Lagrangian.
|
[
{
"created": "Fri, 16 Oct 2015 14:59:57 GMT",
"version": "v1"
}
] |
2022-12-01
|
[
[
"Pósfay",
"Péter",
""
],
[
"Barnaföldi",
"Gergely Gábor",
""
],
[
"Jakovác",
"Antal",
""
]
] |
Functional renormalization group (FRG) is an exact method for taking into account the effect of quantum fluctuations in the effective action of the system. The FRG method applied to effective theories of nuclear matter yields equation of state which incorporates quantum fluctuations of the fields. Using the local potential approximation (LPA) the equation of state for Walecka-type models of nuclear matter under extreme conditions could be determined. These models can be tested by solving the corresponding Tolman--Oppenheimer--Volkov (TOV) equations and investigating the properties (mass and radius) of the corresponding compact star models. Here, we present the first steps on this way, we obtained a Maxwell construction within the FRG-based framework using a Walecka-type Lagrangian.
|
hep-ph/9801260
|
Xiangdong Ji
|
Xiangdong Ji and Jonathan Osborne
|
One-Loop Corrections and All Order Factorization In Deeply Virtual
Compton Scattering
|
Replaced with the version submitted to Phys. Rev. D
|
Phys.Rev. D58 (1998) 094018
|
10.1103/PhysRevD.58.094018
| null |
hep-ph
| null |
We calculate the one-loop corrections to a general off-forward deeply-virtual
Compton process at leading twist for both parton helicity-dependent and
independent cases. We show that the infrared divergences can be factorized
entirely into off-forward parton distributions, even when one of the two
photons is onshell. We argue that this property persists to all orders in
perturbation theory. We obtain the next-to-leading order Wilson coefficients
for the general leading-twist expansion of the product of two electromagnetic
currents in the \overline{\rm MS} scheme.
|
[
{
"created": "Sat, 10 Jan 1998 00:40:20 GMT",
"version": "v1"
},
{
"created": "Tue, 13 Jan 1998 00:17:04 GMT",
"version": "v2"
},
{
"created": "Wed, 21 Jan 1998 00:09:39 GMT",
"version": "v3"
}
] |
2009-10-31
|
[
[
"Ji",
"Xiangdong",
""
],
[
"Osborne",
"Jonathan",
""
]
] |
We calculate the one-loop corrections to a general off-forward deeply-virtual Compton process at leading twist for both parton helicity-dependent and independent cases. We show that the infrared divergences can be factorized entirely into off-forward parton distributions, even when one of the two photons is onshell. We argue that this property persists to all orders in perturbation theory. We obtain the next-to-leading order Wilson coefficients for the general leading-twist expansion of the product of two electromagnetic currents in the \overline{\rm MS} scheme.
|
1910.11530
|
Yi-Lun Du
|
Yi-Lun Du, Kai Zhou, Jan Steinheimer, Long-Gang Pang, Anton
Motornenko, Hong-Shi Zong, Xin-Nian Wang, Horst St\"ocker
|
Identifying the nature of the QCD transition in relativistic collision
of heavy nuclei with deep learning
|
16 pages, 21 figures. Updated version for the publication in Eur.
Phys. J. C
|
Eur. Phys. J. C 80, 516 (2020)
|
10.1140/epjc/s10052-020-8030-7
| null |
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Using deep convolutional neural network (CNN), the nature of the QCD
transition can be identified from the final-state pion spectra from hybrid
model simulations of heavy-ion collisions that combines a viscous hydrodynamic
model with a hadronic cascade "after-burner". Two different types of equations
of state (EoS) of the medium are used in the hydrodynamic evolution. The
resulting spectra in transverse momentum and azimuthal angle are used as the
input data to train the neural network to distinguish different EoS. Different
scenarios for the input data are studied and compared in a systematic way. A
clear hierarchy is observed in the prediction accuracy when using the
event-by-event, cascade-coarse-grained and event-fine-averaged spectra as input
for the network, which are about 80%, 90% and 99%, respectively. A comparison
with the prediction performance by deep neural network (DNN) with only the
normalized pion transverse momentum spectra is also made. High-level features
of pion spectra captured by a carefully-trained neural network were found to be
able to distinguish the nature of the QCD transition even in a simulation
scenario which is close to the experiments.
|
[
{
"created": "Fri, 25 Oct 2019 05:20:25 GMT",
"version": "v1"
},
{
"created": "Sun, 14 Jun 2020 21:47:04 GMT",
"version": "v2"
}
] |
2020-06-16
|
[
[
"Du",
"Yi-Lun",
""
],
[
"Zhou",
"Kai",
""
],
[
"Steinheimer",
"Jan",
""
],
[
"Pang",
"Long-Gang",
""
],
[
"Motornenko",
"Anton",
""
],
[
"Zong",
"Hong-Shi",
""
],
[
"Wang",
"Xin-Nian",
""
],
[
"Stöcker",
"Horst",
""
]
] |
Using deep convolutional neural network (CNN), the nature of the QCD transition can be identified from the final-state pion spectra from hybrid model simulations of heavy-ion collisions that combines a viscous hydrodynamic model with a hadronic cascade "after-burner". Two different types of equations of state (EoS) of the medium are used in the hydrodynamic evolution. The resulting spectra in transverse momentum and azimuthal angle are used as the input data to train the neural network to distinguish different EoS. Different scenarios for the input data are studied and compared in a systematic way. A clear hierarchy is observed in the prediction accuracy when using the event-by-event, cascade-coarse-grained and event-fine-averaged spectra as input for the network, which are about 80%, 90% and 99%, respectively. A comparison with the prediction performance by deep neural network (DNN) with only the normalized pion transverse momentum spectra is also made. High-level features of pion spectra captured by a carefully-trained neural network were found to be able to distinguish the nature of the QCD transition even in a simulation scenario which is close to the experiments.
|
hep-ph/9904371
| null |
David H. Lyth
|
The parameter space for tree-level hybrid inflation
|
7 pages latex
| null | null |
LANCS-TH/9823
|
hep-ph
| null |
In a large region of parameter space, the tree-level hybrid inflation model
is likely to be be invalidated by loop corrections. In particular, this is
likely to be the case if both quartic couplings are of order unity, as is often
supposed. It is likely also to be the case if there is an ultra-violet cutoff
far below the Planck scale, ($\luv\lsim 10^9\GeV(V_0^{1/4}/1\MeV)^{2/5}$, where
$V_0$ is the height of the potential) unless one allows field values bigger
than the cutoff.
|
[
{
"created": "Sat, 17 Apr 1999 10:00:27 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Lyth",
"David H.",
""
]
] |
In a large region of parameter space, the tree-level hybrid inflation model is likely to be be invalidated by loop corrections. In particular, this is likely to be the case if both quartic couplings are of order unity, as is often supposed. It is likely also to be the case if there is an ultra-violet cutoff far below the Planck scale, ($\luv\lsim 10^9\GeV(V_0^{1/4}/1\MeV)^{2/5}$, where $V_0$ is the height of the potential) unless one allows field values bigger than the cutoff.
|
hep-ph/0006349
|
Taekoon Lee
|
Taekoon Lee
|
Resolution of the strong CP problem
|
9 pages;v2 slightly rewritten and expanded;v3 a few points
clarified;v4 minor changes, journal version
|
Int.J.Mod.Phys. A16 (2001) 4321-4330
|
10.1142/S0217751X01005365
| null |
hep-ph hep-th
| null |
It is shown that the quark mass aligns QCD $\theta$ vacuum in such a way that
the strong CP is conserved, resolving the strong CP problem.
|
[
{
"created": "Fri, 30 Jun 2000 18:20:41 GMT",
"version": "v1"
},
{
"created": "Thu, 6 Jul 2000 00:57:04 GMT",
"version": "v2"
},
{
"created": "Thu, 19 Oct 2000 13:13:11 GMT",
"version": "v3"
},
{
"created": "Sun, 22 Jul 2001 22:43:15 GMT",
"version": "v4"
}
] |
2009-10-31
|
[
[
"Lee",
"Taekoon",
""
]
] |
It is shown that the quark mass aligns QCD $\theta$ vacuum in such a way that the strong CP is conserved, resolving the strong CP problem.
|
0804.1265
|
Shun Zhou
|
Wei Chao, Zong-Guo Si, Zhi-zhong Xing and Shun Zhou
|
Correlative signatures of heavy Majorana neutrinos and doubly-charged
Higgs bosons at the Large Hadron Collider
|
RevTEX4 11 pages, 1 figure, more discussions added, published in
Phys. Lett. B
|
Phys.Lett.B666:451-454,2008
|
10.1016/j.physletb.2008.08.003
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We explore an intriguing possibility to test the type-II seesaw mechanism of
neutrino mass generation at the Large Hadron Collider (LHC). We show that the
lepton-number-violating signatures of heavy Majorana neutrinos N_i (for i=1, 2,
3) and doubly-charged Higgs bosons H^++(H^--) can be closely correlated with
each other in a class of TeV-scale type-II seesaw models. Taking the minimal
version of such models for example, we calculate the cross sections of pp ->
l^+_\alpha l^+_\beta X (l^-_\alpha l^-_\beta X) processes mediated separately
by N_1 and H^++(H^--), and illustrate their nontrivial correlation at the LHC.
|
[
{
"created": "Tue, 8 Apr 2008 13:36:12 GMT",
"version": "v1"
},
{
"created": "Thu, 10 Apr 2008 12:41:29 GMT",
"version": "v2"
},
{
"created": "Thu, 28 Aug 2008 09:18:38 GMT",
"version": "v3"
}
] |
2008-11-26
|
[
[
"Chao",
"Wei",
""
],
[
"Si",
"Zong-Guo",
""
],
[
"Xing",
"Zhi-zhong",
""
],
[
"Zhou",
"Shun",
""
]
] |
We explore an intriguing possibility to test the type-II seesaw mechanism of neutrino mass generation at the Large Hadron Collider (LHC). We show that the lepton-number-violating signatures of heavy Majorana neutrinos N_i (for i=1, 2, 3) and doubly-charged Higgs bosons H^++(H^--) can be closely correlated with each other in a class of TeV-scale type-II seesaw models. Taking the minimal version of such models for example, we calculate the cross sections of pp -> l^+_\alpha l^+_\beta X (l^-_\alpha l^-_\beta X) processes mediated separately by N_1 and H^++(H^--), and illustrate their nontrivial correlation at the LHC.
|
1005.0769
|
Felix Riek
|
F. Riek and R. Rapp (Texas A&M, Cyclotron Inst. & Texas A&M)
|
Quarkonia and Heavy-Quark Relaxation Times in the Quark-Gluon Plasma
|
33 pages, 28 figures
|
Phys.Rev.C82:035201,2010
|
10.1103/PhysRevC.82.035201
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
A thermodynamic T-matrix approach for elastic 2-body interactions is employed
to calculate spectral functions of open and hidden heavy-quark systems in the
Quark-Gluon Plasma. This enables the evaluation of quarkonium bound-state
properties and heavy-quark diffusion on a common basis and thus to obtain
mutual constraints. The two-body interaction kernel is approximated within a
potential picture for spacelike momentum transfers. An effective
field-theoretical model combining color-Coulomb and confining terms is
implemented with relativistic corrections and for different color channels.
Four pertinent model parameters, characterizing the coupling strengths and
screening, are adjusted to reproduce the color-average heavy-quark free energy
as computed in thermal lattice QCD. The approach is tested against vacuum
spectroscopy in the open (D, B) and hidden (Psi and Upsilon) flavor sectors, as
well as in the high-energy limit of elastic perturbative QCD scattering.
Theoretical uncertainties in the static reduction scheme of the 4-dimensional
Bethe-Salpeter equation are elucidated. The quarkonium spectral functions are
used to calculate Euclidean correlators which are discussed in light of lattice
QCD results, while heavy-quark relaxation rates and diffusion coefficients are
extracted utilizing a Fokker-Planck equation.
|
[
{
"created": "Wed, 5 May 2010 14:56:45 GMT",
"version": "v1"
}
] |
2014-11-21
|
[
[
"Riek",
"F.",
"",
"Texas A&M, Cyclotron Inst. & Texas A&M"
],
[
"Rapp",
"R.",
"",
"Texas A&M, Cyclotron Inst. & Texas A&M"
]
] |
A thermodynamic T-matrix approach for elastic 2-body interactions is employed to calculate spectral functions of open and hidden heavy-quark systems in the Quark-Gluon Plasma. This enables the evaluation of quarkonium bound-state properties and heavy-quark diffusion on a common basis and thus to obtain mutual constraints. The two-body interaction kernel is approximated within a potential picture for spacelike momentum transfers. An effective field-theoretical model combining color-Coulomb and confining terms is implemented with relativistic corrections and for different color channels. Four pertinent model parameters, characterizing the coupling strengths and screening, are adjusted to reproduce the color-average heavy-quark free energy as computed in thermal lattice QCD. The approach is tested against vacuum spectroscopy in the open (D, B) and hidden (Psi and Upsilon) flavor sectors, as well as in the high-energy limit of elastic perturbative QCD scattering. Theoretical uncertainties in the static reduction scheme of the 4-dimensional Bethe-Salpeter equation are elucidated. The quarkonium spectral functions are used to calculate Euclidean correlators which are discussed in light of lattice QCD results, while heavy-quark relaxation rates and diffusion coefficients are extracted utilizing a Fokker-Planck equation.
|
hep-ph/0302007
|
Dieter Mueller
|
A. Kirchner and D. M\"uller
|
Deeply virtual Compton scattering off nuclei
|
50 pages LaTeX, 7 figures, 3 tables, page style fixed
|
Eur.Phys.J. C32 (2003) 347-375
|
10.1140/epjc/s2003-01415-x
| null |
hep-ph
| null |
We consider the hard leptoproduction of a photon off nuclei up to spin-1. As
a new result we present here the general azimuthal angular dependence of the
differential cross section for a spin-1 target. Its twist-two Fourier
coefficients of the interference and squared deeply virtual Compton scattering
amplitude are evaluated in leading order approximation of perturbation theory
in terms of generalized parton distributions, while the pure Bethe--Heitler
cross section is exactly calculated in terms of electromagnetic form factors.
Relying on a simple model for the nucleon generalized parton distribution $H$,
which describes the existing DVCS data for a proton target, we estimate the
size of unpolarized cross sections, beam and longitudinal target spin as well
as unpolarized charge asymmetries for present fixed target experiments with
nuclei. These estimates are confronted with preliminary HERMES data for
deuterium and neon.
|
[
{
"created": "Sun, 2 Feb 2003 11:47:42 GMT",
"version": "v1"
},
{
"created": "Wed, 5 Feb 2003 21:54:47 GMT",
"version": "v2"
}
] |
2009-11-10
|
[
[
"Kirchner",
"A.",
""
],
[
"Müller",
"D.",
""
]
] |
We consider the hard leptoproduction of a photon off nuclei up to spin-1. As a new result we present here the general azimuthal angular dependence of the differential cross section for a spin-1 target. Its twist-two Fourier coefficients of the interference and squared deeply virtual Compton scattering amplitude are evaluated in leading order approximation of perturbation theory in terms of generalized parton distributions, while the pure Bethe--Heitler cross section is exactly calculated in terms of electromagnetic form factors. Relying on a simple model for the nucleon generalized parton distribution $H$, which describes the existing DVCS data for a proton target, we estimate the size of unpolarized cross sections, beam and longitudinal target spin as well as unpolarized charge asymmetries for present fixed target experiments with nuclei. These estimates are confronted with preliminary HERMES data for deuterium and neon.
|
hep-ph/0004030
|
Francesco Caravaglios
|
Francesco Caravaglios
|
How to Integrate Divergent Integrals: a Pure Numerical Approach to
Complex Loop Calculations
|
13 pages, 1 Postscript figure
|
Nucl.Phys. B589 (2000) 475-486
|
10.1016/S0550-3213(00)00391-6
|
LPT-ORSAY 0036
|
hep-ph
| null |
Loop calculations involve the evaluation of divergent integrals.
Usually [1] one computes them in a number of dimensions different than four
where the integral is convergent and then one performs the analytical
continuation and considers the Laurent expansion in powers of epsilon =n-4. In
this paper we discuss a method to extract directly all coefficients of this
expansion by means of concrete and well defined integrals in a five dimensional
space. We by-pass the formal and symbolic procedure of analytic continuation;
instead we can numerically compute the integrals to extract directly both the
coefficient of the pole 1/epsilon and the finite part.
|
[
{
"created": "Tue, 4 Apr 2000 17:21:17 GMT",
"version": "v1"
}
] |
2009-10-31
|
[
[
"Caravaglios",
"Francesco",
""
]
] |
Loop calculations involve the evaluation of divergent integrals. Usually [1] one computes them in a number of dimensions different than four where the integral is convergent and then one performs the analytical continuation and considers the Laurent expansion in powers of epsilon =n-4. In this paper we discuss a method to extract directly all coefficients of this expansion by means of concrete and well defined integrals in a five dimensional space. We by-pass the formal and symbolic procedure of analytic continuation; instead we can numerically compute the integrals to extract directly both the coefficient of the pole 1/epsilon and the finite part.
|
2208.14746
|
Hagop Sazdjian
|
Hagop Sazdjian
|
Impact of clustering inside compact tetraquarks
|
7 pages, 5 figures. Talk given at the International Workshop QCD@Work
- Theory and Experiment, Lecce (Italy), 27-30 June 2022
|
EPJ Web Conf. 270, 00011 (2022)
|
10.1051/epjconf/202227000011
| null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
Due to the reducibility of tetraquark operators into mesonic clusters, a
strong interplay exists in tetraquarks between compact and molecular
structures. This issue is studied within an effective field theory approach,
where the compact tetraquark is treated as an elementary particle. Under the
influence of the coupling to the mesonic clusters, an initially formed compact
tetraquark bound state is deformed towards a new structure of the molecular
type, having the attributes of a shallow bound state.
|
[
{
"created": "Wed, 31 Aug 2022 09:48:35 GMT",
"version": "v1"
}
] |
2022-12-01
|
[
[
"Sazdjian",
"Hagop",
""
]
] |
Due to the reducibility of tetraquark operators into mesonic clusters, a strong interplay exists in tetraquarks between compact and molecular structures. This issue is studied within an effective field theory approach, where the compact tetraquark is treated as an elementary particle. Under the influence of the coupling to the mesonic clusters, an initially formed compact tetraquark bound state is deformed towards a new structure of the molecular type, having the attributes of a shallow bound state.
|
1312.6862
|
Shinsuke Yoshida
|
Hiroo Beppu (Niigata U), Koichi Kanazawa (Niigata U, Temple U), Yuji
Koike (Niigata U) and Shinsuke Yoshida (RIKEN, BNL)
|
Three-gluon contribution to the single spin asymmetry for light hadron
production in pp collision
|
16 pages, 11figures
| null |
10.1103/PhysRevD.89.034029
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study the twist-3 three-gluon contribution to the single spin asymmetry in
the light-hadron production in pp collision in the framework of the collinear
factorization. We derive the corresponding cross section formula in the leading
order with respect to the QCD coupling constant. We also present a numerical
calculation of the asymmetry at the RHIC energy, using a model for the
three-gluon correlation functions suggested by the asymmetry observed in the
$D$-meson production at RHIC.
|
[
{
"created": "Tue, 24 Dec 2013 18:09:42 GMT",
"version": "v1"
}
] |
2015-06-18
|
[
[
"Beppu",
"Hiroo",
"",
"Niigata U"
],
[
"Kanazawa",
"Koichi",
"",
"Niigata U, Temple U"
],
[
"Koike",
"Yuji",
"",
"Niigata U"
],
[
"Yoshida",
"Shinsuke",
"",
"RIKEN, BNL"
]
] |
We study the twist-3 three-gluon contribution to the single spin asymmetry in the light-hadron production in pp collision in the framework of the collinear factorization. We derive the corresponding cross section formula in the leading order with respect to the QCD coupling constant. We also present a numerical calculation of the asymmetry at the RHIC energy, using a model for the three-gluon correlation functions suggested by the asymmetry observed in the $D$-meson production at RHIC.
|
1404.1825
|
Luis Anchordoqui
|
Luis A. Anchordoqui, Haim Goldberg, Xing Huang, Brian J. Vlcek
|
Reconciling BICEP2 and Planck results with right-handed Dirac neutrinos
in the fundamental representation of grand unified E_6
|
14 pages revtex, 4 figures
| null |
10.1088/1475-7516/2014/06/042
| null |
hep-ph astro-ph.CO
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The tensor-to-scalar ratio (r = 0.20^{+0.07}_{-0.05}) inferred from the
excess B-mode power observed by the Background Imaging of Cosmic Extragalactic
Polarization (BICEP2) experiment is almost twice as large as the 95% CL upper
limits derived from temperature measurements of the WMAP (r<0.13) and Planck
(r<0.11) space missions. Very recently, it was suggested that additional
relativistic degrees of freedom beyond the three active neutrinos and photons
can help to relieve this tension: the data favor an effective number of light
neutrino species N_{eff} = 3.86 \pm 0.25. Since the BICEP2 ratio implies the
energy scale of inflation (V_*^{1/4} \sim 2 \times 10^{16} GeV) is comparable
to the grand unification scale, in this paper we investigate whether we can
accommodate the required N_{eff} with three right-handed (partners of the
left-handed standard model) neutrinos living in the fundamental representation
of a grand unified exceptional E_6 group. We show that the superweak
interactions of these Dirac states (through their coupling to a TeV-scale Z'
gauge boson) lead to decoupling of right-handed neutrino just above the QCD
cross over transition: 175 MeV < T_{\nu_R}^{dec} < 250 MeV. For decoupling in
this transition region, the contribution of the three right-handed neutrinos to
N_{eff} is suppressed by heating of the left-handed neutrinos (and photons).
Consistency (within 1\sigma) with the favored N_{eff} is achieved for 4.5 TeV <
M_{Z'} < 7.5 TeV. The model is fully predictive and can be confronted with
future data from LHC14.
|
[
{
"created": "Mon, 7 Apr 2014 16:01:25 GMT",
"version": "v1"
}
] |
2015-06-19
|
[
[
"Anchordoqui",
"Luis A.",
""
],
[
"Goldberg",
"Haim",
""
],
[
"Huang",
"Xing",
""
],
[
"Vlcek",
"Brian J.",
""
]
] |
The tensor-to-scalar ratio (r = 0.20^{+0.07}_{-0.05}) inferred from the excess B-mode power observed by the Background Imaging of Cosmic Extragalactic Polarization (BICEP2) experiment is almost twice as large as the 95% CL upper limits derived from temperature measurements of the WMAP (r<0.13) and Planck (r<0.11) space missions. Very recently, it was suggested that additional relativistic degrees of freedom beyond the three active neutrinos and photons can help to relieve this tension: the data favor an effective number of light neutrino species N_{eff} = 3.86 \pm 0.25. Since the BICEP2 ratio implies the energy scale of inflation (V_*^{1/4} \sim 2 \times 10^{16} GeV) is comparable to the grand unification scale, in this paper we investigate whether we can accommodate the required N_{eff} with three right-handed (partners of the left-handed standard model) neutrinos living in the fundamental representation of a grand unified exceptional E_6 group. We show that the superweak interactions of these Dirac states (through their coupling to a TeV-scale Z' gauge boson) lead to decoupling of right-handed neutrino just above the QCD cross over transition: 175 MeV < T_{\nu_R}^{dec} < 250 MeV. For decoupling in this transition region, the contribution of the three right-handed neutrinos to N_{eff} is suppressed by heating of the left-handed neutrinos (and photons). Consistency (within 1\sigma) with the favored N_{eff} is achieved for 4.5 TeV < M_{Z'} < 7.5 TeV. The model is fully predictive and can be confronted with future data from LHC14.
|
1207.0179
|
Koji Tsumura
|
Hiroaki Sugiyama, Koji Tsumura, Hiroshi Yokoya
|
Discrimination of models including doubly charged scalar bosons by using
tau lepton decay distributions
|
13 pages, 8 eps files; published in Physics Letter B
| null |
10.1016/j.physletb.2012.09.044
|
UT-HET 070
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The doubly charged scalar boson (H^{\pm\pm}) is introduced in several models
of the new physics beyond the standard model. The H^{\pm\pm} has Yukawa
interactions with two left-handed charged leptons or two right-handed charged
leptons depending on the models. We study kinematical properties of H^{\pm\pm}
decay products through tau leptons in order to discriminate the chiral
structures of the new Yukawa interaction. The chirality of tau leptons can be
measured by the energy distributions of the tau decay products, and thus the
chiral structure of the new Yukawa interaction can be traced in the
invariant-mass distributions of the H^{\pm\pm} decay products. We perform
simulation studies for the typical decay patterns of the H^{\pm\pm} with simple
event selections and tau-tagging procedures, and show that the chiral structure
of the Yukawa interactions of H^{\pm\pm} can be distinguished by measuring the
invariant-mass distributions.
|
[
{
"created": "Sun, 1 Jul 2012 05:31:46 GMT",
"version": "v1"
},
{
"created": "Fri, 5 Oct 2012 07:05:44 GMT",
"version": "v2"
}
] |
2015-06-05
|
[
[
"Sugiyama",
"Hiroaki",
""
],
[
"Tsumura",
"Koji",
""
],
[
"Yokoya",
"Hiroshi",
""
]
] |
The doubly charged scalar boson (H^{\pm\pm}) is introduced in several models of the new physics beyond the standard model. The H^{\pm\pm} has Yukawa interactions with two left-handed charged leptons or two right-handed charged leptons depending on the models. We study kinematical properties of H^{\pm\pm} decay products through tau leptons in order to discriminate the chiral structures of the new Yukawa interaction. The chirality of tau leptons can be measured by the energy distributions of the tau decay products, and thus the chiral structure of the new Yukawa interaction can be traced in the invariant-mass distributions of the H^{\pm\pm} decay products. We perform simulation studies for the typical decay patterns of the H^{\pm\pm} with simple event selections and tau-tagging procedures, and show that the chiral structure of the Yukawa interactions of H^{\pm\pm} can be distinguished by measuring the invariant-mass distributions.
|
1106.0764
|
Joern Kersten
|
Jan Heisig and Joern Kersten
|
Production of long-lived staus in the Drell-Yan process
|
15 pages + references, 12 eps figures; v2: analysis for 7 TeV LHC
added, other results unchanged, minor improvements in presentation,
references added; v3: presentation improved, matches journal version
|
Phys. Rev. D 84, 115009 (2011)
|
10.1103/PhysRevD.84.115009
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We investigate the phenomenology of the gravitino dark matter scenario with a
stau as the next-to-lightest supersymmetric particle at the LHC. For a wide
range of gravitino masses the lighter stau is stable on the scale of a detector
and gives rise to a prominent signature as a "slow muon". The direct stau
production via the Drell-Yan process is always present and independent of the
mass spectrum of the other superparticles, thus providing a lower bound for the
discovery potential of this scenario. Performing a careful analysis with
particular emphasis on the criteria for observing stau pairs and for
distinguishing them from the background, we find that the 14 TeV run of the LHC
has a promising potential for finding long-lived staus from Drell-Yan
production up to very large stau masses.
|
[
{
"created": "Fri, 3 Jun 2011 20:57:20 GMT",
"version": "v1"
},
{
"created": "Tue, 26 Jul 2011 17:15:50 GMT",
"version": "v2"
},
{
"created": "Thu, 15 Dec 2011 17:04:01 GMT",
"version": "v3"
}
] |
2011-12-16
|
[
[
"Heisig",
"Jan",
""
],
[
"Kersten",
"Joern",
""
]
] |
We investigate the phenomenology of the gravitino dark matter scenario with a stau as the next-to-lightest supersymmetric particle at the LHC. For a wide range of gravitino masses the lighter stau is stable on the scale of a detector and gives rise to a prominent signature as a "slow muon". The direct stau production via the Drell-Yan process is always present and independent of the mass spectrum of the other superparticles, thus providing a lower bound for the discovery potential of this scenario. Performing a careful analysis with particular emphasis on the criteria for observing stau pairs and for distinguishing them from the background, we find that the 14 TeV run of the LHC has a promising potential for finding long-lived staus from Drell-Yan production up to very large stau masses.
|
1001.5193
|
Guy F. de T\'eramond
|
Guy F. de Teramond and Stanley J. Brodsky
|
Light-Front Quantization Approach to the Gauge-Gravity Correspondence
and Hadron Spectroscopy
|
17 pages, 2 figures, Invited talk presented at Hadron 2009, The
International Conference on Hadron Spectroscopy, Florida State University,
Tallahassee, November 29 - December 4, 2009
| null |
10.1063/1.3483402
|
SLAC-PUB-13875
|
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We find a correspondence between semiclassical QCD quantized on the
light-front and a dual gravity model in anti--de Sitter (AdS) space, thus
providing an initial approximation to QCD in its strongly coupled regime. This
correspondence -- light-front holography -- leads to a light-front Hamiltonian
and relativistic bound-state wave equations that are functions of an invariant
impact variable $\zeta$ which measures the separation of the quark and gluonic
constituents within hadrons at equal light-front time. The eigenvalues of the
resulting light-front Schr\"odinger and Dirac equations are consistent with the
observed light meson and baryon spectrum, and the eigenmodes provide the
light-front wavefunctions, the probability amplitudes describing the dynamics
of the hadronic constituents. The light-front equations of motion, which are
dual to an effective classical gravity theory, possess remarkable algebraic and
integrability properties which are dictated by the underlying conformal
properties of the theory. We extend the algebraic construction to include a
confining potential while preserving the integrability of the mesonic and
baryonic bound-state equations.
|
[
{
"created": "Thu, 28 Jan 2010 20:59:58 GMT",
"version": "v1"
},
{
"created": "Fri, 29 Jan 2010 00:28:29 GMT",
"version": "v2"
}
] |
2015-05-18
|
[
[
"de Teramond",
"Guy F.",
""
],
[
"Brodsky",
"Stanley J.",
""
]
] |
We find a correspondence between semiclassical QCD quantized on the light-front and a dual gravity model in anti--de Sitter (AdS) space, thus providing an initial approximation to QCD in its strongly coupled regime. This correspondence -- light-front holography -- leads to a light-front Hamiltonian and relativistic bound-state wave equations that are functions of an invariant impact variable $\zeta$ which measures the separation of the quark and gluonic constituents within hadrons at equal light-front time. The eigenvalues of the resulting light-front Schr\"odinger and Dirac equations are consistent with the observed light meson and baryon spectrum, and the eigenmodes provide the light-front wavefunctions, the probability amplitudes describing the dynamics of the hadronic constituents. The light-front equations of motion, which are dual to an effective classical gravity theory, possess remarkable algebraic and integrability properties which are dictated by the underlying conformal properties of the theory. We extend the algebraic construction to include a confining potential while preserving the integrability of the mesonic and baryonic bound-state equations.
|
hep-ph/9901203
|
Gerald Cleaver
|
Gerald B. Cleaver
|
M-fluences on String Model Building
|
CPT '98 Talk. 7 pages. Standard Latex. Discussion of material in
hep-ph/9811427 revised to conform to changes in published version of
hep-ph/9811427. Reference updates and correction
| null | null |
CTP-TAMU-46/98
|
hep-ph hep-th
| null |
Common to many classes of three family SU(3)_C x SU(2)_L x U(1)_Y string
models are an additional anomalous U(1)_A and numerous, often fractionally
charged, exotic particles beyond the minimal supersymmetric standard model
(MSSM). I present one string model with both of these properties. Using this
model as an example, I show how sometimes (near) string scale vacuum
expectation values that are both D- and F-flat (to all orders in the
superpotential) can simultaneously break the anomalous U(1)_A and give heavy
mass to all phenomenologically dangerous exotic states, decoupling them from
the low energy spectrum. For this model, some anomaly cancelling directions
actually decouple all MSSM exotics, producing the MSSM as the effective field
theory just below the string scale. This model realizes Witten's conjecture of
possible equivalence between the string scale M_S and the MSSM unification
scale M_MSSM. Talk presented at CPT '98, Bloomington, Indiana, 6--8 November
1998
|
[
{
"created": "Fri, 1 Jan 1999 21:00:19 GMT",
"version": "v1"
},
{
"created": "Mon, 26 Apr 1999 21:11:35 GMT",
"version": "v2"
}
] |
2007-05-23
|
[
[
"Cleaver",
"Gerald B.",
""
]
] |
Common to many classes of three family SU(3)_C x SU(2)_L x U(1)_Y string models are an additional anomalous U(1)_A and numerous, often fractionally charged, exotic particles beyond the minimal supersymmetric standard model (MSSM). I present one string model with both of these properties. Using this model as an example, I show how sometimes (near) string scale vacuum expectation values that are both D- and F-flat (to all orders in the superpotential) can simultaneously break the anomalous U(1)_A and give heavy mass to all phenomenologically dangerous exotic states, decoupling them from the low energy spectrum. For this model, some anomaly cancelling directions actually decouple all MSSM exotics, producing the MSSM as the effective field theory just below the string scale. This model realizes Witten's conjecture of possible equivalence between the string scale M_S and the MSSM unification scale M_MSSM. Talk presented at CPT '98, Bloomington, Indiana, 6--8 November 1998
|
1410.8056
|
Ivan Girardi
|
I. Girardi, S. T. Petcov and A. V. Titov
|
Determining the Dirac CP Violation Phase in the Neutrino Mixing Matrix
from Sum Rules
|
37 pages, includes 18 figures and 10 tables; results in v.4
unchanged; typos corrected; matches published version.
|
Nucl. Phys. B 894 (2015) 733-768
|
10.1016/j.nuclphysb.2015.03.026
|
SISSA 58/2014/FISI; IPMU14-0331
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Using the fact that the neutrino mixing matrix $U = U^\dagger_{e}U_{\nu}$,
where $U_{e}$ and $U_{\nu}$ result from the diagonalisation of the charged
lepton and neutrino mass matrices, we analyse the sum rules which the Dirac
phase $\delta$ present in $U$ satisfies when $U_{\nu}$ has a form dictated by
flavour symmetries and $U_e$ has a "minimal" form (in terms of angles and
phases it contains) that can provide the requisite corrections to $U_{\nu}$, so
that reactor, atmospheric and solar neutrino mixing angles $\theta_{13}$,
$\theta_{23}$ and $\theta_{12}$ have values compatible with the current data.
The following symmetry forms are considered: i) tri-bimaximal (TBM), ii)
bimaximal (BM) (or corresponding to the conservation of the lepton charge $L' =
L_e - L_\mu - L_{\tau}$ (LC)), iii) golden ratio type A (GRA), iv) golden ratio
type B (GRB), and v) hexagonal (HG). We investigate the predictions for
$\delta$ in the cases of TBM, BM (LC), GRA, GRB and HG forms using the exact
and the leading order sum rules for $\cos\delta$ proposed in the literature,
taking into account also the uncertainties in the measured values of
$\sin^2\theta_{12}$, $\sin^2\theta_{23}$ and $\sin^2\theta_{13}$. This allows
us, in particular, to assess the accuracy of the predictions for $\cos\delta$
based on the leading order sum rules and its dependence on the values of the
indicated neutrino mixing parameters when the latter are varied in their
respective 3$\sigma$ experimentally allowed ranges.
|
[
{
"created": "Wed, 29 Oct 2014 16:45:48 GMT",
"version": "v1"
},
{
"created": "Mon, 10 Nov 2014 17:57:59 GMT",
"version": "v2"
},
{
"created": "Tue, 23 Dec 2014 16:43:06 GMT",
"version": "v3"
},
{
"created": "Thu, 5 Mar 2015 11:27:00 GMT",
"version": "v4"
},
{
"created": "Mon, 13 Apr 2015 17:08:31 GMT",
"version": "v5"
}
] |
2015-04-24
|
[
[
"Girardi",
"I.",
""
],
[
"Petcov",
"S. T.",
""
],
[
"Titov",
"A. V.",
""
]
] |
Using the fact that the neutrino mixing matrix $U = U^\dagger_{e}U_{\nu}$, where $U_{e}$ and $U_{\nu}$ result from the diagonalisation of the charged lepton and neutrino mass matrices, we analyse the sum rules which the Dirac phase $\delta$ present in $U$ satisfies when $U_{\nu}$ has a form dictated by flavour symmetries and $U_e$ has a "minimal" form (in terms of angles and phases it contains) that can provide the requisite corrections to $U_{\nu}$, so that reactor, atmospheric and solar neutrino mixing angles $\theta_{13}$, $\theta_{23}$ and $\theta_{12}$ have values compatible with the current data. The following symmetry forms are considered: i) tri-bimaximal (TBM), ii) bimaximal (BM) (or corresponding to the conservation of the lepton charge $L' = L_e - L_\mu - L_{\tau}$ (LC)), iii) golden ratio type A (GRA), iv) golden ratio type B (GRB), and v) hexagonal (HG). We investigate the predictions for $\delta$ in the cases of TBM, BM (LC), GRA, GRB and HG forms using the exact and the leading order sum rules for $\cos\delta$ proposed in the literature, taking into account also the uncertainties in the measured values of $\sin^2\theta_{12}$, $\sin^2\theta_{23}$ and $\sin^2\theta_{13}$. This allows us, in particular, to assess the accuracy of the predictions for $\cos\delta$ based on the leading order sum rules and its dependence on the values of the indicated neutrino mixing parameters when the latter are varied in their respective 3$\sigma$ experimentally allowed ranges.
|
2406.19179
|
Gurucharan Mohanta
|
Gurucharan Mohanta, Ketan M. Patel
|
Loop-induced masses for the first two generations with optimum flavour
violation
|
32 pages, 4 tables, 6 figures
| null | null | null |
hep-ph hep-th
|
http://creativecommons.org/licenses/by/4.0/
|
A mechanism for the masses of third, second, and first generation charged
fermions at the tree, 1-loop, and 2-loop levels, respectively, is proposed. The
fermionic self-energy corrections that lead to this arrangement are induced
through heavy vector bosons of a new gauged flavour symmetry group $G_F$. It is
shown that a single Abelian group suffices as $G_F$. Moreover, the gauge
charges are optimized to result in relatively smaller flavour violations in
processes involving the first and second generation fermions. The scheme is
explicitly implemented on the Standard Model fermions in an anomaly-free manner
and is shown to be viable with observed charged fermion masses and quark
mixings. Constraints from flavour violations dictate the lower limit on the new
physics scale in these types of frameworks. Through optimal flavour violation,
it is shown that nearly two orders of magnitude improvement can be achieved on
the lower limit, leading to the new physics scale $\ge 10^3$ TeV in this case.
Further improvements are possible at the cost of the down quark mass deviating
more than $3 \sigma$ from its value extracted from lattice calculations.
Options for inducing tiny masses for light neutrinos are also discussed.
|
[
{
"created": "Thu, 27 Jun 2024 13:55:36 GMT",
"version": "v1"
}
] |
2024-06-28
|
[
[
"Mohanta",
"Gurucharan",
""
],
[
"Patel",
"Ketan M.",
""
]
] |
A mechanism for the masses of third, second, and first generation charged fermions at the tree, 1-loop, and 2-loop levels, respectively, is proposed. The fermionic self-energy corrections that lead to this arrangement are induced through heavy vector bosons of a new gauged flavour symmetry group $G_F$. It is shown that a single Abelian group suffices as $G_F$. Moreover, the gauge charges are optimized to result in relatively smaller flavour violations in processes involving the first and second generation fermions. The scheme is explicitly implemented on the Standard Model fermions in an anomaly-free manner and is shown to be viable with observed charged fermion masses and quark mixings. Constraints from flavour violations dictate the lower limit on the new physics scale in these types of frameworks. Through optimal flavour violation, it is shown that nearly two orders of magnitude improvement can be achieved on the lower limit, leading to the new physics scale $\ge 10^3$ TeV in this case. Further improvements are possible at the cost of the down quark mass deviating more than $3 \sigma$ from its value extracted from lattice calculations. Options for inducing tiny masses for light neutrinos are also discussed.
|
1903.12336
|
Yu-xin Liu
|
Zhan Bai, Yu-xin Liu
|
Determining Hadron-Quark Phase Transition Chemical Potential via
Astronomical Observations
|
14 pages, 5 figures, 3 tables. Version to appear in Phys. Rev. D
| null | null | null |
hep-ph astro-ph.HE
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We propose a scheme to determine the chemical potential and baryon number
density of the hadron-quark phase transition in cold dense strong interaction
matter (compact star matter). The hadron matter is described with the
relativistic mean field theory, and the quark matter is described with the
Dyson-Schwinger equation approach of QCD. To study the first-order phase
transition, we take the sound speed as the interpolation objective to construct
the equation of state in the middle density region. With the maximum mass, the
tidal deformability and the radius of neutron stars being taken as calibration
quantities, the phase transition chemical potential is constrained to a quite
small range. And the most probable value of the phase transition chemical
potential is found.
|
[
{
"created": "Fri, 29 Mar 2019 02:45:09 GMT",
"version": "v1"
},
{
"created": "Thu, 25 May 2023 03:43:58 GMT",
"version": "v2"
}
] |
2023-05-26
|
[
[
"Bai",
"Zhan",
""
],
[
"Liu",
"Yu-xin",
""
]
] |
We propose a scheme to determine the chemical potential and baryon number density of the hadron-quark phase transition in cold dense strong interaction matter (compact star matter). The hadron matter is described with the relativistic mean field theory, and the quark matter is described with the Dyson-Schwinger equation approach of QCD. To study the first-order phase transition, we take the sound speed as the interpolation objective to construct the equation of state in the middle density region. With the maximum mass, the tidal deformability and the radius of neutron stars being taken as calibration quantities, the phase transition chemical potential is constrained to a quite small range. And the most probable value of the phase transition chemical potential is found.
|
hep-ph/0307064
|
Alan D. Martin
|
A.B. Kaidalov, V.A. Khoze, A.D. Martin and M.G. Ryskin
|
Central exclusive diffractive production as a spin--parity analyser:
from hadrons to Higgs
|
19 pages, 7 figures. Version to be published in EPJC: Subsection 3.2
and one reference added; Figures 4,5,6,7 modified
|
Eur.Phys.J. C31 (2003) 387-396
|
10.1140/epjc/s2003-01371-5
|
IPPP/03/35, DCPT/03/70
|
hep-ph
| null |
We present the general rules for double-Reggeon production of objects with
different spins and parities. The existing experimental information on
resonance production in these central exclusive diffractive processes is
discussed. The absorptive corrections are calculated and found to depend
strongly on the quantum numbers of the produced states. The central exclusive
diffractive production of 0^+ and 0^- Higgs bosons is studied as an
illustrative topical example of the use of the general rules. The signal for
diffractive 0^+ and 0^- Higgs production at the LHC is evaluated using, as an
example, the minimal supersymmetric model, with large tan(beta).
|
[
{
"created": "Fri, 4 Jul 2003 14:23:38 GMT",
"version": "v1"
},
{
"created": "Mon, 29 Sep 2003 09:51:15 GMT",
"version": "v2"
}
] |
2009-11-10
|
[
[
"Kaidalov",
"A. B.",
""
],
[
"Khoze",
"V. A.",
""
],
[
"Martin",
"A. D.",
""
],
[
"Ryskin",
"M. G.",
""
]
] |
We present the general rules for double-Reggeon production of objects with different spins and parities. The existing experimental information on resonance production in these central exclusive diffractive processes is discussed. The absorptive corrections are calculated and found to depend strongly on the quantum numbers of the produced states. The central exclusive diffractive production of 0^+ and 0^- Higgs bosons is studied as an illustrative topical example of the use of the general rules. The signal for diffractive 0^+ and 0^- Higgs production at the LHC is evaluated using, as an example, the minimal supersymmetric model, with large tan(beta).
|
2008.11741
|
Pierluca Carenza
|
Francesca Calore, Pierluca Carenza, Maurizio Giannotti, Joerg Jaeckel,
Alessandro Mirizzi
|
Bounds on axion-like particles from the diffuse supernova flux
|
12 pages, 7 figures. v2: minor changes to match the published version
|
Phys. Rev. D 102, 123005 (2020)
|
10.1103/PhysRevD.102.123005
| null |
hep-ph astro-ph.HE
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The cumulative emission of Axion-Like Particles (ALPs) from all past
core-collapse supernovae (SNe) would lead to a diffuse flux with energies
${\mathcal O}(50)$ MeV. We use this to constrain ALPs featuring couplings to
photons and to nucleons. ALPs coupled only to photons are produced in the SN
core via the Primakoff process, and then converted into gamma rays in the
Galactic magnetic field. We set a bound on $g_{a\gamma} \lesssim 5 \times
10^{-10}~{\rm GeV}^{-1}$ for $m_a \lesssim 10^{-11}~{\rm eV}$, using recent
measurements of the diffuse gamma-ray flux observed by the Fermi-LAT telescope.
However, if ALPs couple also with nucleons, their production rate in SN can be
considerably enhanced due to the ALPs nucleon-nucleon bremsstrahlung process.
Assuming the largest ALP-nucleon coupling phenomenologically allowed, bounds on
the diffuse gamma-ray flux lead to a much stronger $g_{a\gamma} \lesssim 6
\times 10^{-13}~{\rm GeV}^{-1}$ for the same mass range. If ALPs are heavier
than $\sim$ keV, the decay into photons becomes significant, leading again to a
diffuse gamma-ray flux. In the case of only photon coupling, we find, e.g.
$g_{a\gamma} \lesssim 5 \times 10^{-11}~{\rm GeV}^{-1}$ for $m_a \sim 5~{\rm
keV}$. Allowing for a (maximal) coupling to nucleons, the limit improves to the
level of $g_{a\gamma} \lesssim 10^{-19}~{\rm GeV}^{-1}$ for $m_a \sim 20~{\rm
MeV}$, which represents the strongest constraint to date.
|
[
{
"created": "Wed, 26 Aug 2020 18:00:06 GMT",
"version": "v1"
},
{
"created": "Wed, 2 Dec 2020 07:15:34 GMT",
"version": "v2"
}
] |
2020-12-03
|
[
[
"Calore",
"Francesca",
""
],
[
"Carenza",
"Pierluca",
""
],
[
"Giannotti",
"Maurizio",
""
],
[
"Jaeckel",
"Joerg",
""
],
[
"Mirizzi",
"Alessandro",
""
]
] |
The cumulative emission of Axion-Like Particles (ALPs) from all past core-collapse supernovae (SNe) would lead to a diffuse flux with energies ${\mathcal O}(50)$ MeV. We use this to constrain ALPs featuring couplings to photons and to nucleons. ALPs coupled only to photons are produced in the SN core via the Primakoff process, and then converted into gamma rays in the Galactic magnetic field. We set a bound on $g_{a\gamma} \lesssim 5 \times 10^{-10}~{\rm GeV}^{-1}$ for $m_a \lesssim 10^{-11}~{\rm eV}$, using recent measurements of the diffuse gamma-ray flux observed by the Fermi-LAT telescope. However, if ALPs couple also with nucleons, their production rate in SN can be considerably enhanced due to the ALPs nucleon-nucleon bremsstrahlung process. Assuming the largest ALP-nucleon coupling phenomenologically allowed, bounds on the diffuse gamma-ray flux lead to a much stronger $g_{a\gamma} \lesssim 6 \times 10^{-13}~{\rm GeV}^{-1}$ for the same mass range. If ALPs are heavier than $\sim$ keV, the decay into photons becomes significant, leading again to a diffuse gamma-ray flux. In the case of only photon coupling, we find, e.g. $g_{a\gamma} \lesssim 5 \times 10^{-11}~{\rm GeV}^{-1}$ for $m_a \sim 5~{\rm keV}$. Allowing for a (maximal) coupling to nucleons, the limit improves to the level of $g_{a\gamma} \lesssim 10^{-19}~{\rm GeV}^{-1}$ for $m_a \sim 20~{\rm MeV}$, which represents the strongest constraint to date.
|
1108.6172
|
Peter Zeiler Skands
|
Aude Gehrmann-De Ridder, Mathias Ritzmann, Peter Skands
|
Timelike Dipole-Antenna Showers with Massive Fermions
|
50 pages; v3: corrected typo in eq.(35)
| null |
10.1103/PhysRevD.85.014013
|
CERN-TH-2011-133; MCNET-11-19
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We present a complete formalism for final-state (timelike) dipole-antenna
showers including fermion masses, but neglecting polarization and finite-width
effects. We make several comparisons of tree-level expansions of this shower
algorithm to fixed-order matrix elements for hadronic Z decays, up to and
including Z to 6 partons, to which the algorithm can be consistently matched
over all of phase space. We also compare to analytical resummations at the NLL
level. The shower algorithm has been implemented in the publicly available
VINCIA plugin to the PYTHIA 8 event generator, which enables us to compare to
experimental data at the fully hadronized level. We also include comparisons to
selected observables in b-tagged Z decays.
|
[
{
"created": "Wed, 31 Aug 2011 09:32:50 GMT",
"version": "v1"
},
{
"created": "Thu, 1 Dec 2011 14:11:02 GMT",
"version": "v2"
},
{
"created": "Wed, 21 Nov 2018 02:31:33 GMT",
"version": "v3"
}
] |
2018-11-22
|
[
[
"Ridder",
"Aude Gehrmann-De",
""
],
[
"Ritzmann",
"Mathias",
""
],
[
"Skands",
"Peter",
""
]
] |
We present a complete formalism for final-state (timelike) dipole-antenna showers including fermion masses, but neglecting polarization and finite-width effects. We make several comparisons of tree-level expansions of this shower algorithm to fixed-order matrix elements for hadronic Z decays, up to and including Z to 6 partons, to which the algorithm can be consistently matched over all of phase space. We also compare to analytical resummations at the NLL level. The shower algorithm has been implemented in the publicly available VINCIA plugin to the PYTHIA 8 event generator, which enables us to compare to experimental data at the fully hadronized level. We also include comparisons to selected observables in b-tagged Z decays.
|
hep-ph/9510291
|
L. L. Frankfurt
|
Leonid Frankfurt (Tel Aviv Univ.) and Mark Strikman (Penn. State
Univ.)
|
QCD and Diffraction in DIS
|
Talk at the Workshop on Deep Inelastic Scattering and QCD, Paris,
April 1995, 17 pages LATEX, uses "qcdparis.sty" needed (appended at end), one
ps figure in separeted uuncode file
| null | null | null |
hep-ph
| null |
Coherence phenomena, and the non-universality of parton structure of the
effective Pomeron are explained. New hard phenomena directly calculable in QCD
such as diffractive electroproduction of states with $M^2\ll Q^2$ as well as
new options to measure the light-cone wave functions of various hadrons are
considered. An analogue of Bjorken scaling is predicted for the diffractive
electroproduction of $\rho$ mesons at large momentum transfers and for the
production of large rapidity gap events, as observed at HERA. A
phenomenological QCD evolution equation is suggested to calculate the basic
characteristics of the large rapidity gap events. The increase of parton
densities at small $x$ as well as new means to disentangle experimentally soft
and hard physics are considered. We discuss constraints on the increase of deep
inelastic amplitudes with $Q^2$ derived from unitarity of the S matrix for
collisions of wave packets. New ways to probe QCD physics of hard processes at
large longitudinal distances and to answer the long standing problems on the
origin of the Pomeron are suggested. Unresolved problems and perspectives of
small $x$ physics are also outlined.
|
[
{
"created": "Sun, 15 Oct 1995 19:03:35 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Frankfurt",
"Leonid",
"",
"Tel Aviv Univ."
],
[
"Strikman",
"Mark",
"",
"Penn. State\n Univ."
]
] |
Coherence phenomena, and the non-universality of parton structure of the effective Pomeron are explained. New hard phenomena directly calculable in QCD such as diffractive electroproduction of states with $M^2\ll Q^2$ as well as new options to measure the light-cone wave functions of various hadrons are considered. An analogue of Bjorken scaling is predicted for the diffractive electroproduction of $\rho$ mesons at large momentum transfers and for the production of large rapidity gap events, as observed at HERA. A phenomenological QCD evolution equation is suggested to calculate the basic characteristics of the large rapidity gap events. The increase of parton densities at small $x$ as well as new means to disentangle experimentally soft and hard physics are considered. We discuss constraints on the increase of deep inelastic amplitudes with $Q^2$ derived from unitarity of the S matrix for collisions of wave packets. New ways to probe QCD physics of hard processes at large longitudinal distances and to answer the long standing problems on the origin of the Pomeron are suggested. Unresolved problems and perspectives of small $x$ physics are also outlined.
|
1910.06126
|
Qi-Fang Lu
|
Qi-Fang L\"u, Xian-Hui Zhong
|
Strong decays of the higher excited $\Lambda_Q$ and $\Sigma_Q$ baryons
|
16 pages, 9 figures, 17 tables, version accepted by Physical Review D
|
Phys. Rev. D 101, 014017 (2020)
|
10.1103/PhysRevD.101.014017
| null |
hep-ph hep-ex nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In this work, we preform a systematic study of the strong decays for the
higher singly heavy baryon resonances $\Lambda_Q(3S)$, $\Lambda_Q(2P)$,
$\Lambda_Q(2D)$, $\Lambda_Q(1F)$, $\Sigma_Q(3S)$, $\Sigma_Q(2P)$,
$\Sigma_Q(2D)$, and $\Sigma_Q(1F)$ within the $^3P_0$ model. Our results show
that most of the $\lambda-$mode higher excited $\Lambda_Q$ and $\Sigma_Q$
states have a relatively narrow width, and mainly decay into two-body final
states with one heavy meson plus one light baryon. Our calculations provide
abundant theoretical information and demonstrate the general feature for these
higher states, which may be valuable for future experimental searches and
establishing the singly heavy baryon spectrum.
|
[
{
"created": "Mon, 14 Oct 2019 13:17:44 GMT",
"version": "v1"
},
{
"created": "Tue, 7 Jan 2020 03:06:56 GMT",
"version": "v2"
}
] |
2020-01-29
|
[
[
"Lü",
"Qi-Fang",
""
],
[
"Zhong",
"Xian-Hui",
""
]
] |
In this work, we preform a systematic study of the strong decays for the higher singly heavy baryon resonances $\Lambda_Q(3S)$, $\Lambda_Q(2P)$, $\Lambda_Q(2D)$, $\Lambda_Q(1F)$, $\Sigma_Q(3S)$, $\Sigma_Q(2P)$, $\Sigma_Q(2D)$, and $\Sigma_Q(1F)$ within the $^3P_0$ model. Our results show that most of the $\lambda-$mode higher excited $\Lambda_Q$ and $\Sigma_Q$ states have a relatively narrow width, and mainly decay into two-body final states with one heavy meson plus one light baryon. Our calculations provide abundant theoretical information and demonstrate the general feature for these higher states, which may be valuable for future experimental searches and establishing the singly heavy baryon spectrum.
|
1509.05771
|
Enrico Maria Sessolo
|
Arghya Choudhury, Kamila Kowalska, Leszek Roszkowski, Enrico Maria
Sessolo, Andrew J. Williams
|
Less-simplified models of dark matter for direct detection and the LHC
|
29 pages, 9 figures. Text matches published version. References added
|
JHEP 1604 (2016) 182
|
10.1007/JHEP04(2016)182
| null |
hep-ph astro-ph.CO hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We construct models of dark matter with suppressed spin-independent
scattering cross section utilizing the existing simplified model framework.
Even simple combinations of simplified models can exhibit interference effects
that cause the tree level contribution to the scattering cross section to
vanish, thus demonstrating that direct detection limits on simplified models
are not robust when embedded in a more complicated and realistic framework. In
general for fermionic WIMP masses >10 GeV direct detection limits on the
spin-independent scattering cross section are much stronger than those coming
from the LHC. However these model combinations, which we call less-simplified
models, represent situations where LHC searches become more competitive than
direct detection experiments even for moderate dark matter mass. We show that a
complementary use of several searches at the LHC can strongly constrain the
direct detection blind spots by setting limits on the coupling constants and
mediators' mass. We derive the strongest limits for combinations of vector +
scalar, vector + "squark", and "squark" + scalar mediator, and present the
corresponding projections for the LHC 14 TeV for a number of searches:
mono-jet, jets + missing energy, and searches for heavy vector resonances.
|
[
{
"created": "Fri, 18 Sep 2015 20:03:51 GMT",
"version": "v1"
},
{
"created": "Wed, 6 Apr 2016 10:18:09 GMT",
"version": "v2"
},
{
"created": "Fri, 27 May 2016 12:50:18 GMT",
"version": "v3"
}
] |
2016-05-30
|
[
[
"Choudhury",
"Arghya",
""
],
[
"Kowalska",
"Kamila",
""
],
[
"Roszkowski",
"Leszek",
""
],
[
"Sessolo",
"Enrico Maria",
""
],
[
"Williams",
"Andrew J.",
""
]
] |
We construct models of dark matter with suppressed spin-independent scattering cross section utilizing the existing simplified model framework. Even simple combinations of simplified models can exhibit interference effects that cause the tree level contribution to the scattering cross section to vanish, thus demonstrating that direct detection limits on simplified models are not robust when embedded in a more complicated and realistic framework. In general for fermionic WIMP masses >10 GeV direct detection limits on the spin-independent scattering cross section are much stronger than those coming from the LHC. However these model combinations, which we call less-simplified models, represent situations where LHC searches become more competitive than direct detection experiments even for moderate dark matter mass. We show that a complementary use of several searches at the LHC can strongly constrain the direct detection blind spots by setting limits on the coupling constants and mediators' mass. We derive the strongest limits for combinations of vector + scalar, vector + "squark", and "squark" + scalar mediator, and present the corresponding projections for the LHC 14 TeV for a number of searches: mono-jet, jets + missing energy, and searches for heavy vector resonances.
|
2205.03000
|
Tingfei Li
|
Bo Feng, Chang Hu, Tingfei Li and Yuekai Song
|
Reduction with Degenerate Gram matrix for One-loop Integrals
|
46 pages, no figures
| null |
10.1007/JHEP08(2022)110
| null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
An improved PV-reduction method for one-loop integrals with auxiliary vector
$R$ has been proposed in \cite{Feng:2021enk,Hu:2021nia}. It has also been shown
that the new method is a self-completed method in \cite{Feng:2022uqp}. Analytic
reduction coefficients can be easily produced by recursion relations in this
method, where the Gram determinant appears in denominators. The singularity
caused by Gram determinant is a well-known fact and it is important to address
these divergences in a given frame. In this paper, we propose a systematical
algorithm to deal with this problem in our method. The key idea is that now the
master integral of the highest topology will be decomposed into combinations of
master integrals of lower topologies. By demanding the cancellation of
divergence for obtained general reduction coefficients, we solve decomposition
coefficients as a Taylor series of the Gram determinant. Moreover, the same
idea can be applied to other kinds of divergences.
|
[
{
"created": "Fri, 6 May 2022 03:51:20 GMT",
"version": "v1"
},
{
"created": "Wed, 22 Jun 2022 01:47:57 GMT",
"version": "v2"
}
] |
2022-08-24
|
[
[
"Feng",
"Bo",
""
],
[
"Hu",
"Chang",
""
],
[
"Li",
"Tingfei",
""
],
[
"Song",
"Yuekai",
""
]
] |
An improved PV-reduction method for one-loop integrals with auxiliary vector $R$ has been proposed in \cite{Feng:2021enk,Hu:2021nia}. It has also been shown that the new method is a self-completed method in \cite{Feng:2022uqp}. Analytic reduction coefficients can be easily produced by recursion relations in this method, where the Gram determinant appears in denominators. The singularity caused by Gram determinant is a well-known fact and it is important to address these divergences in a given frame. In this paper, we propose a systematical algorithm to deal with this problem in our method. The key idea is that now the master integral of the highest topology will be decomposed into combinations of master integrals of lower topologies. By demanding the cancellation of divergence for obtained general reduction coefficients, we solve decomposition coefficients as a Taylor series of the Gram determinant. Moreover, the same idea can be applied to other kinds of divergences.
|
0705.1503
|
Sacha Davidson
|
Sacha Davidson, Julia Garayoa, Federica Palorini, Nuria Rius
|
Insensitivity of flavoured leptogenesis to low energy CP violation
|
4 pages, 1 figure; version accepted for publication, added
explanations, notation clarified
|
Phys.Rev.Lett.99:161801,2007
|
10.1103/PhysRevLett.99.161801
| null |
hep-ph
| null |
If the baryon asymmetry of the Universe is produced by leptogenesis, CP
violation is required in the lepton sector. In the seesaw extension of the
Standard Model with three hierarchical right-handed neutrinos, we show that the
baryon asymmetry is insensitive to the PMNS phases: thermal leptogenesis can
work for any value of the observable phases. This result was well-known when
there are no flavour effects in leptogenesis; we show that it remains true when
flavour effects are included.
|
[
{
"created": "Thu, 10 May 2007 16:05:45 GMT",
"version": "v1"
},
{
"created": "Mon, 21 May 2007 12:55:20 GMT",
"version": "v2"
},
{
"created": "Mon, 15 Oct 2007 10:18:27 GMT",
"version": "v3"
}
] |
2008-11-26
|
[
[
"Davidson",
"Sacha",
""
],
[
"Garayoa",
"Julia",
""
],
[
"Palorini",
"Federica",
""
],
[
"Rius",
"Nuria",
""
]
] |
If the baryon asymmetry of the Universe is produced by leptogenesis, CP violation is required in the lepton sector. In the seesaw extension of the Standard Model with three hierarchical right-handed neutrinos, we show that the baryon asymmetry is insensitive to the PMNS phases: thermal leptogenesis can work for any value of the observable phases. This result was well-known when there are no flavour effects in leptogenesis; we show that it remains true when flavour effects are included.
|
1107.2646
|
Kuang-Ta Chao
|
Kai Wang, Yan-Qing Ma, Kuang-Ta Chao
|
QCD corrections to e^+ e^- to J/\psi(\psi(2S))+\chi_{cJ} (J=0,1,2) at B
Factories
|
Version published in PRD, 6 pages, 3 figures, 2 tables, one reference
added
|
Phys.Rev.D84:034022,2011
|
10.1103/PhysRevD.84.034022
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We analytically calculate the cross sections of double charmonium production
in $e^+ e^- \to J/\psi(\psi(2S))\chi_{cJ}$ (J=0,1,2) at next-to-leading order
(NLO) in $\alpha_s$ in nonrelativistic QCD, and confirm factorization of these
processes. In contrast to $\chi_{c0}$ production, for which the NLO correction
is large and positive, the NLO corrections for $\chi_{c1,2}$ production can be
negative, resulting in decreased $K$ factors of 0.91 and 0.78 for J=1 and 2
respectively when $\mu = 2 m_{c}$. Consequently, the NLO QCD corrections
markedly enlarge the difference between cross sections of $\chi_{c0}$ and
$\chi_{c1,2}$. This may explain why $e^+ e^- \to J/\psi(\psi(2S))\chi_{c0}$ but
not $e^+ e^- \to J/\psi(\psi(2S))\chi_{c1,2}$ is observed experimentally.
Moreover, for $J/\psi(\psi(2S))\chi_{c1,2}$, the NLO QCD corrections
substantially reduce the $\mu$ dependence and lead to predictions with small
theoretical uncertainties.
|
[
{
"created": "Wed, 13 Jul 2011 19:56:16 GMT",
"version": "v1"
},
{
"created": "Mon, 15 Aug 2011 17:27:15 GMT",
"version": "v2"
}
] |
2011-09-08
|
[
[
"Wang",
"Kai",
""
],
[
"Ma",
"Yan-Qing",
""
],
[
"Chao",
"Kuang-Ta",
""
]
] |
We analytically calculate the cross sections of double charmonium production in $e^+ e^- \to J/\psi(\psi(2S))\chi_{cJ}$ (J=0,1,2) at next-to-leading order (NLO) in $\alpha_s$ in nonrelativistic QCD, and confirm factorization of these processes. In contrast to $\chi_{c0}$ production, for which the NLO correction is large and positive, the NLO corrections for $\chi_{c1,2}$ production can be negative, resulting in decreased $K$ factors of 0.91 and 0.78 for J=1 and 2 respectively when $\mu = 2 m_{c}$. Consequently, the NLO QCD corrections markedly enlarge the difference between cross sections of $\chi_{c0}$ and $\chi_{c1,2}$. This may explain why $e^+ e^- \to J/\psi(\psi(2S))\chi_{c0}$ but not $e^+ e^- \to J/\psi(\psi(2S))\chi_{c1,2}$ is observed experimentally. Moreover, for $J/\psi(\psi(2S))\chi_{c1,2}$, the NLO QCD corrections substantially reduce the $\mu$ dependence and lead to predictions with small theoretical uncertainties.
|
1410.1947
|
Xu Sun
|
X. Sun, H. Masui, A. M. Poskanzer and A. Schmah
|
Blast Wave Fits to Elliptic Flow Data at $\sqrt{s_{\rm NN}} =$ 7.7--2760
GeV
|
7 pages, 4 figures
|
Phys. Rev. C 91, 024903 (2015)
|
10.1103/PhysRevC.91.024903
| null |
hep-ph nucl-ex nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We present blast wave fits to elliptic flow ($v_{2}(p_{\rm T})$) data in
minimum bias collisions from the $\sqrt{s_{\rm NN}} =$ 7.7--200 GeV at RHIC,
and 2.76 TeV at LHC. The fits are performed separately for particles and
corresponding anti-particles. The mean transverse velocity parameter $\beta$
shows an energy dependent difference between particles and corresponding
anti-particles, which increases as the beam energy decreases. Possible effects
of feed down, baryon stopping, anti-particle absorption, and early production
times for anti-particles are discussed.
|
[
{
"created": "Wed, 8 Oct 2014 00:01:27 GMT",
"version": "v1"
},
{
"created": "Wed, 18 Feb 2015 03:55:35 GMT",
"version": "v2"
}
] |
2015-03-05
|
[
[
"Sun",
"X.",
""
],
[
"Masui",
"H.",
""
],
[
"Poskanzer",
"A. M.",
""
],
[
"Schmah",
"A.",
""
]
] |
We present blast wave fits to elliptic flow ($v_{2}(p_{\rm T})$) data in minimum bias collisions from the $\sqrt{s_{\rm NN}} =$ 7.7--200 GeV at RHIC, and 2.76 TeV at LHC. The fits are performed separately for particles and corresponding anti-particles. The mean transverse velocity parameter $\beta$ shows an energy dependent difference between particles and corresponding anti-particles, which increases as the beam energy decreases. Possible effects of feed down, baryon stopping, anti-particle absorption, and early production times for anti-particles are discussed.
|
hep-ph/9903317
|
Vicente Pleitez
|
J. C. Montero, V. Pleitez and M. C. Rodriguez
|
L-R asymmetries and signals for new bosons
|
Revtex, 7 pages, one .eps figure. Contribution to the VIII Mexican
School of Particles and Fields, Oaxaca de Ju\'arez, Oax, M\'exico, November
20--29, 1998
|
AIP Conf.Proc.490:397-400,1999
|
10.1063/1.1301408
|
IFT-P.024/99
|
hep-ph
| null |
Several left-right parity violating asymmetries in lepton-lepton scattering
in fixed target and collider experiments are considered as signals for doubly
charged vector bosons (bileptons).
|
[
{
"created": "Wed, 10 Mar 1999 20:26:04 GMT",
"version": "v1"
}
] |
2010-12-13
|
[
[
"Montero",
"J. C.",
""
],
[
"Pleitez",
"V.",
""
],
[
"Rodriguez",
"M. C.",
""
]
] |
Several left-right parity violating asymmetries in lepton-lepton scattering in fixed target and collider experiments are considered as signals for doubly charged vector bosons (bileptons).
|
hep-ph/0110170
|
Basarab Nicolescu
|
B. Nicolescu, J. R. Cudell, V. V. Ezhela, P. Gauron, K. Kang, Yu. V.
Kuyanov, S. B. Lugovsky, and N. P. Tkachenko
|
Analytic parametrizations of the non-perturbative Pomeron and
QCD-inspired models
|
11 pages, 2 tables, Presented at the 9th Blois Workshop on Elastic
and Diffractive Scattering, Pruhonice, Czech Republic, 9-15 June 2001
| null | null |
LPNHE 2001-09
|
hep-ph
| null |
We consider several classes of analytic parametrizations of hadronic
scattering amplitudes, and compare their predictions to all available forward
data (proton- proton, antiproton-proton, pion-proton, kaon-proton,
photon-proton, photon- photon, sigma-proton). Although these parametrizations
are very close for energy larger than 9 GeV, it turns out that they differ
markedly at low energy, where a universal Pomeron term ~(ln s)**2 enables one
to extend the fit down to 4 GeV.
|
[
{
"created": "Fri, 12 Oct 2001 16:17:50 GMT",
"version": "v1"
},
{
"created": "Tue, 30 Oct 2001 17:54:57 GMT",
"version": "v2"
},
{
"created": "Tue, 27 Nov 2001 14:56:15 GMT",
"version": "v3"
}
] |
2007-05-23
|
[
[
"Nicolescu",
"B.",
""
],
[
"Cudell",
"J. R.",
""
],
[
"Ezhela",
"V. V.",
""
],
[
"Gauron",
"P.",
""
],
[
"Kang",
"K.",
""
],
[
"Kuyanov",
"Yu. V.",
""
],
[
"Lugovsky",
"S. B.",
""
],
[
"Tkachenko",
"N. P.",
""
]
] |
We consider several classes of analytic parametrizations of hadronic scattering amplitudes, and compare their predictions to all available forward data (proton- proton, antiproton-proton, pion-proton, kaon-proton, photon-proton, photon- photon, sigma-proton). Although these parametrizations are very close for energy larger than 9 GeV, it turns out that they differ markedly at low energy, where a universal Pomeron term ~(ln s)**2 enables one to extend the fit down to 4 GeV.
|
1209.4904
|
Yuri Shirman
|
Mohammad Abdullah, Iftah Galon, Yael Shadmi, and Yuri Shirman
|
Flavored Gauge Mediation, A Heavy Higgs, and Supersymmetric Alignment
|
30 pages, 4 figures. Allowed regions of the FGM parameter space
modified based on corrected expressions for the superpartner masses at the
messenger scale. A new appendix added with a detailed discussion of the
derivation of the FGM formulas, based both on the analytic continuation
method and an explicit two-loop calculation. References added
| null |
10.1007/JHEP06(2013)057
| null |
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We show that the messenger-matter couplings of Flavored Gauge Mediation
Models can generate substantial stop mixing, leading to Higgs masses around 126
GeV with colored superpartners below 2 TeV and even a TeV. These results are
largely independent of the messenger scale. We study the spectra of a few
examples with a single messenger pair coupling dominantly to the top, for
different messenger scales. Flavor constraints in these models are obeyed by
virtue of supersymmetric alignment: the same flavor symmetry that explains
fermion masses dictates the structure of the matter-messenger couplings, and
this structure is inherited by the soft terms. We also present the leading
1-loop and 2-loop contributions to the soft terms for general coupling matrices
in generation space.
|
[
{
"created": "Fri, 21 Sep 2012 20:00:13 GMT",
"version": "v1"
},
{
"created": "Tue, 9 Apr 2013 17:09:30 GMT",
"version": "v2"
}
] |
2015-06-11
|
[
[
"Abdullah",
"Mohammad",
""
],
[
"Galon",
"Iftah",
""
],
[
"Shadmi",
"Yael",
""
],
[
"Shirman",
"Yuri",
""
]
] |
We show that the messenger-matter couplings of Flavored Gauge Mediation Models can generate substantial stop mixing, leading to Higgs masses around 126 GeV with colored superpartners below 2 TeV and even a TeV. These results are largely independent of the messenger scale. We study the spectra of a few examples with a single messenger pair coupling dominantly to the top, for different messenger scales. Flavor constraints in these models are obeyed by virtue of supersymmetric alignment: the same flavor symmetry that explains fermion masses dictates the structure of the matter-messenger couplings, and this structure is inherited by the soft terms. We also present the leading 1-loop and 2-loop contributions to the soft terms for general coupling matrices in generation space.
|
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