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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
hep-ph/9610494 | Christian Cardall | Christian Y. Cardall and George M. Fuller (UC San Diego) | Neutrino oscillations in curved spacetime: an heuristic treatment | 7 pages, REVTeX and 1 included style file. Submitted to Phys. Rev. D | Phys.Rev. D55 (1997) 7960-7966 | 10.1103/PhysRevD.55.7960 | null | hep-ph astro-ph gr-qc | null | We discuss neutrino oscillations in curved spacetime. Our heuristic approach
can accomodate matter effects and gravitational contributions to neutrino spin
precession in the presence of a magnetic field. By way of illustration, we
perform explicit calculations in the Schwarzschild geometry. In this case,
gravitational effects on neutrino oscillations are intimately related to the
redshift. We discuss how spacetime curvature could affect the resonance
position and adiabaticity of matter-enhanced neutrino flavor conversion.
| [
{
"created": "Fri, 25 Oct 1996 23:06:27 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Cardall",
"Christian Y.",
"",
"UC San Diego"
],
[
"Fuller",
"George M.",
"",
"UC San Diego"
]
] | We discuss neutrino oscillations in curved spacetime. Our heuristic approach can accomodate matter effects and gravitational contributions to neutrino spin precession in the presence of a magnetic field. By way of illustration, we perform explicit calculations in the Schwarzschild geometry. In this case, gravitational effects on neutrino oscillations are intimately related to the redshift. We discuss how spacetime curvature could affect the resonance position and adiabaticity of matter-enhanced neutrino flavor conversion. |
1805.04597 | Daniel Gomez Dumm | D. G\'omez Dumm, M.F. Izzo Villafa\~ne, S. Noguera, V. Pagura, N.N.
Scoccola | Effects of strong magnetic fields on quark matter and $\pi^0$ properties
within nonlocal chiral quark models | 6 pages, 4 figures. Invited talk presented at the XIV International
Workshop on Hadron Physics, Florian\'opolis, Brazil, March 2018 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the behavior of strongly interacting matter under a strong external
magnetic field in the context of chiral quark models that include nonlocal
interactions. In particular, we analyze the influence of a constant magnetic
field on the chiral quark condensates at zero and finite temperature, studying
the deconfinement and chiral restoration critical temperatures and discussing
the observed "magnetic catalysis" and "inverse magnetic catalysis" effects. In
addition, we analyze in this framework the behavior of the $\pi^0$ mass and
decay constant. The predictions of nonlocal chiral quark models are compared
with results obtained in lattice QCD.
| [
{
"created": "Fri, 11 May 2018 21:30:22 GMT",
"version": "v1"
},
{
"created": "Tue, 17 Jul 2018 23:35:47 GMT",
"version": "v2"
}
] | 2018-07-19 | [
[
"Dumm",
"D. Gómez",
""
],
[
"Villafañe",
"M. F. Izzo",
""
],
[
"Noguera",
"S.",
""
],
[
"Pagura",
"V.",
""
],
[
"Scoccola",
"N. N.",
""
]
] | We study the behavior of strongly interacting matter under a strong external magnetic field in the context of chiral quark models that include nonlocal interactions. In particular, we analyze the influence of a constant magnetic field on the chiral quark condensates at zero and finite temperature, studying the deconfinement and chiral restoration critical temperatures and discussing the observed "magnetic catalysis" and "inverse magnetic catalysis" effects. In addition, we analyze in this framework the behavior of the $\pi^0$ mass and decay constant. The predictions of nonlocal chiral quark models are compared with results obtained in lattice QCD. |
hep-ph/9810229 | Jyh-Liong Lim | Jyh-Liong Lim | A New Unified Evolution Equation | 4 pages in 1 LaTex file with 3 .eps file | null | null | jllim-001 | hep-ph | null | WE propose a new unified evolution equation for parton distribution functions
appropriate for both large and small Bjorken x. Compared with the Ciafaloni-
Catani-Fiorani-Marchesini equation, the cancellation of soft poles between
virtual and real gluon emissions is made explicitly without introducing
infrared cutoffs, next-to-leading contributions to the Sudakov resummation can
be included systematically, and the scales of the running coupling constants
are determined unambiguously.
| [
{
"created": "Fri, 2 Oct 1998 14:49:05 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Lim",
"Jyh-Liong",
""
]
] | WE propose a new unified evolution equation for parton distribution functions appropriate for both large and small Bjorken x. Compared with the Ciafaloni- Catani-Fiorani-Marchesini equation, the cancellation of soft poles between virtual and real gluon emissions is made explicitly without introducing infrared cutoffs, next-to-leading contributions to the Sudakov resummation can be included systematically, and the scales of the running coupling constants are determined unambiguously. |
hep-ph/0702196 | Francesco Hautmann | F. Hautmann | Endpoint singularities in unintegrated parton distributions | null | Phys.Lett.B655:26-31,2007 | 10.1016/j.physletb.2007.08.081 | null | hep-ph | null | We examine the singular behavior from the endpoint region x -> 1 in parton
distributions unintegrated in both longitudinal and transverse momenta. We
identify and regularize the singularities by using the subtraction method, and
compare this with the cut-off regularization method. The counterterms for the
distributions with subtractive regularization are given in coordinate space by
compact all-order expressions in terms of eikonal-line operators. We carry out
an explicit calculation at one loop for the unintegrated quark distribution. We
discuss the relation of the unintegrated parton distributions in subtractive
regularization with the ordinary parton distributions.
| [
{
"created": "Mon, 19 Feb 2007 18:57:47 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Hautmann",
"F.",
""
]
] | We examine the singular behavior from the endpoint region x -> 1 in parton distributions unintegrated in both longitudinal and transverse momenta. We identify and regularize the singularities by using the subtraction method, and compare this with the cut-off regularization method. The counterterms for the distributions with subtractive regularization are given in coordinate space by compact all-order expressions in terms of eikonal-line operators. We carry out an explicit calculation at one loop for the unintegrated quark distribution. We discuss the relation of the unintegrated parton distributions in subtractive regularization with the ordinary parton distributions. |
0805.4069 | Tadeusz Wibig | Tadeusz Wibig | On the Discovery of the GZK Cut-off | 10 pages | Pramana 73:807-820,2009 | 10.1007/s12043-009-0149-x | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The recent claim of the '5 sigma' observation of the Greisen and Zatzepin and
Kuzmin cut-off by the HiRes group based on their nine years data is a
significant step toward the eventual solution of the one of the most intriguing
questions which has been present in physics for more than forty years. However
the word 'significance' is used in the mentioned paper in the sense which is
not quite obvious. In the present paper we persuade that this claim is a little
premature.
| [
{
"created": "Tue, 27 May 2008 08:22:39 GMT",
"version": "v1"
}
] | 2010-11-02 | [
[
"Wibig",
"Tadeusz",
""
]
] | The recent claim of the '5 sigma' observation of the Greisen and Zatzepin and Kuzmin cut-off by the HiRes group based on their nine years data is a significant step toward the eventual solution of the one of the most intriguing questions which has been present in physics for more than forty years. However the word 'significance' is used in the mentioned paper in the sense which is not quite obvious. In the present paper we persuade that this claim is a little premature. |
2005.00292 | Florian Nortier | Florian Nortier | Compactified Spacelike Extra Dimension & Brane-Higgs Field | 244 pages. PhD thesis manuscript. Part I "State of the Art" in French
and Part II "Original Research Work" in English | null | 10.5281/zenodo.4974619 | tel-02976693, 2020UPASS070 | hep-ph hep-th quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the paradigm with a small warped Spacelike Extra Dimensions (SED), the
Higgs field is in general localized at a boundary of the SED (TeV-brane) where
the gravity scale is redshifted to the TeV by a warp factor. If the SM gauge
bosons and fermions propagate into the warped SED, one can generate the mass
hierarchy for fermions. It is thus crucial to treat carefully the TeV-brane
localized masses for such fermions, which is done in the literature by applying
a regularization process suffering from a lack of consistency and more
importantly being useless, as we demonstrate in detail in the present thesis.
The first part of the thesis is devoted to the treatment of brane localized
mass terms for 5D fermions, which requires the introduction of new Lagrangian
terms at the SED boundaries, similar to the Gibbons-Hawking terms in gravity.
The second part consists in applying different methods (function/distribution
fields, 4D/5D calculations, etc) to various brane localized terms (kinetic
terms, Majorana masses, etc), as well as a generalization to several classified
models (flat/warped dimensions, intervalle/orbifold, etc). In the third part,
we propose to compactify a flat SED on a star/rose graph with a large number of
identical small leaves/petals. We obtain a compactified space with a large
volume without a large compactification length to stabilize. We use the
approach of 5D fermions to build a toy model of small Dirac neutrino masses
(brane localized left-handed neutrinos and bulk right-handed ones).
| [
{
"created": "Fri, 1 May 2020 10:08:27 GMT",
"version": "v1"
},
{
"created": "Sun, 2 Aug 2020 10:11:40 GMT",
"version": "v2"
}
] | 2021-06-18 | [
[
"Nortier",
"Florian",
""
]
] | In the paradigm with a small warped Spacelike Extra Dimensions (SED), the Higgs field is in general localized at a boundary of the SED (TeV-brane) where the gravity scale is redshifted to the TeV by a warp factor. If the SM gauge bosons and fermions propagate into the warped SED, one can generate the mass hierarchy for fermions. It is thus crucial to treat carefully the TeV-brane localized masses for such fermions, which is done in the literature by applying a regularization process suffering from a lack of consistency and more importantly being useless, as we demonstrate in detail in the present thesis. The first part of the thesis is devoted to the treatment of brane localized mass terms for 5D fermions, which requires the introduction of new Lagrangian terms at the SED boundaries, similar to the Gibbons-Hawking terms in gravity. The second part consists in applying different methods (function/distribution fields, 4D/5D calculations, etc) to various brane localized terms (kinetic terms, Majorana masses, etc), as well as a generalization to several classified models (flat/warped dimensions, intervalle/orbifold, etc). In the third part, we propose to compactify a flat SED on a star/rose graph with a large number of identical small leaves/petals. We obtain a compactified space with a large volume without a large compactification length to stabilize. We use the approach of 5D fermions to build a toy model of small Dirac neutrino masses (brane localized left-handed neutrinos and bulk right-handed ones). |
2107.13815 | Jan Nemchik | M. Krelina, J. Nemchik | Momentum transfer dependence of heavy quarkonium electroproduction | 5 pages, submission to SciPost, proceedings of DIS2021 | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We investigate the momentum transfer dependence of differential cross
sections $d\sigma/dt$ in diffractive electroproduction of heavy quarkonia on
proton targets. Model predictions for $d\sigma/dt$ within the light-front QCD
dipole formalism are based on a realistic model for a proper correlation
between the impact parameter $\vec b$ of a collision and color dipole
orientation $\vec r$. We demonstrate a significance of $\vec b-\vec r$
correlation by comparing with a standard simplification
$\vec{b}\parallel\vec{r}$, frequently used in the literature.
| [
{
"created": "Thu, 29 Jul 2021 08:26:02 GMT",
"version": "v1"
}
] | 2021-07-30 | [
[
"Krelina",
"M.",
""
],
[
"Nemchik",
"J.",
""
]
] | We investigate the momentum transfer dependence of differential cross sections $d\sigma/dt$ in diffractive electroproduction of heavy quarkonia on proton targets. Model predictions for $d\sigma/dt$ within the light-front QCD dipole formalism are based on a realistic model for a proper correlation between the impact parameter $\vec b$ of a collision and color dipole orientation $\vec r$. We demonstrate a significance of $\vec b-\vec r$ correlation by comparing with a standard simplification $\vec{b}\parallel\vec{r}$, frequently used in the literature. |
hep-ph/0212339 | K. S. Babu | K.S. Babu, Ilia Gogoladze and Kai Wang (Oklahoma State University) | Stabilizing the Axion by Discrete Gauge Symmetries | 14 pages LateX | Phys.Lett. B560 (2003) 214-222 | 10.1016/S0370-2693(03)00411-8 | OSU-HEP-02-18 | hep-ph | null | The axion solution to the strong CP problem makes use of a global
Peccei-Quinn U(1) symmetry which is susceptible to violations from quantum
gravitational effects. We show how discrete gauge symmetries can protect the
axion from such violations. PQ symmetry emerges as an approximate global
symmetry from discrete gauge symmetries. Simple models based on Z_N symmetries
with N =11,12, etc are presented realizing the DFSZ axion and the KSVZ axion.
The discrete gauge anomalies are cancelled by a discrete version of the
Green-Schwarz mechanism. In the supersymmetric extension our models provide a
natural link between the SUSY breaking scale, the axion scale, and the
SUSY-preserving \mu term.
| [
{
"created": "Mon, 23 Dec 2002 11:24:14 GMT",
"version": "v1"
}
] | 2010-04-05 | [
[
"Babu",
"K. S.",
"",
"Oklahoma State University"
],
[
"Gogoladze",
"Ilia",
"",
"Oklahoma State University"
],
[
"Wang",
"Kai",
"",
"Oklahoma State University"
]
] | The axion solution to the strong CP problem makes use of a global Peccei-Quinn U(1) symmetry which is susceptible to violations from quantum gravitational effects. We show how discrete gauge symmetries can protect the axion from such violations. PQ symmetry emerges as an approximate global symmetry from discrete gauge symmetries. Simple models based on Z_N symmetries with N =11,12, etc are presented realizing the DFSZ axion and the KSVZ axion. The discrete gauge anomalies are cancelled by a discrete version of the Green-Schwarz mechanism. In the supersymmetric extension our models provide a natural link between the SUSY breaking scale, the axion scale, and the SUSY-preserving \mu term. |
1806.02370 | Saurabh Bansal | Saurabh Bansal, Rodolfo M. Capdevilla, Antonio Delgado, Christopher
Kolda, Adam Martin, Nirmal Raj | Hunting leptoquarks in monolepton searches | 9 pages, 5 figures | Phys. Rev. D 98, 015037 (2018) | 10.1103/PhysRevD.98.015037 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We show that stringent limits on leptoquarks that couple to first-generation
quarks and left-handed electrons or muons can be derived from the spectral
shape of the charged-current Drell-Yan process ($p p \to \ell^\pm \nu$) at Run
2 of the LHC. We identify and examine all six leptoquark species that can
generate such a monolepton signal, including both scalar and vector
leptoquarks, and find cases where the leptoquark exchange interferes
constructively, destructively or not at all with the Standard Model signal.
When combined with the corresponding leptoquark-mediated neutral-current ($p p
\to \ell^+ \ell^-$) process, we find the most stringent limits obtained to
date, outperforming bounds from pair production and atomic parity violation. We
show that, with 3000 fb$^{-1}$ of data, combined measurements of the transverse
mass in $p p \to \ell^\pm \nu$ events and invariant mass in $p p \to \ell^+
\ell^-$ events can probe masses between 8 TeV and 18 TeV, depending on the
species of leptoquark, for electroweak-sized couplings. In light of such robust
sensitivities, we strongly encourage the LHC experiments to interpret Drell-Yan
(dilepton and monolepton) events in terms of leptoquarks, alongside usual
scenarios like $Z'$ bosons and contact interactions.
| [
{
"created": "Wed, 6 Jun 2018 18:22:20 GMT",
"version": "v1"
}
] | 2018-08-01 | [
[
"Bansal",
"Saurabh",
""
],
[
"Capdevilla",
"Rodolfo M.",
""
],
[
"Delgado",
"Antonio",
""
],
[
"Kolda",
"Christopher",
""
],
[
"Martin",
"Adam",
""
],
[
"Raj",
"Nirmal",
""
]
] | We show that stringent limits on leptoquarks that couple to first-generation quarks and left-handed electrons or muons can be derived from the spectral shape of the charged-current Drell-Yan process ($p p \to \ell^\pm \nu$) at Run 2 of the LHC. We identify and examine all six leptoquark species that can generate such a monolepton signal, including both scalar and vector leptoquarks, and find cases where the leptoquark exchange interferes constructively, destructively or not at all with the Standard Model signal. When combined with the corresponding leptoquark-mediated neutral-current ($p p \to \ell^+ \ell^-$) process, we find the most stringent limits obtained to date, outperforming bounds from pair production and atomic parity violation. We show that, with 3000 fb$^{-1}$ of data, combined measurements of the transverse mass in $p p \to \ell^\pm \nu$ events and invariant mass in $p p \to \ell^+ \ell^-$ events can probe masses between 8 TeV and 18 TeV, depending on the species of leptoquark, for electroweak-sized couplings. In light of such robust sensitivities, we strongly encourage the LHC experiments to interpret Drell-Yan (dilepton and monolepton) events in terms of leptoquarks, alongside usual scenarios like $Z'$ bosons and contact interactions. |
hep-ph/9409326 | Pittau | F. Berends, R, Kleiss and R. Pittau | EXCALIBUR -- a Monte Carlo program to evaluate all four fermion
processes at LEP 200 and beyond | INLO-PUB-12/94, 24 pages including figures, Latex file | Comput.Phys.Commun. 85 (1995) 437-452 | 10.1016/0010-4655(94)00138-R | null | hep-ph | null | A Monte Carlo program is presented that computes all four fermion processes
in $e^+ e^-$ annihilation. QED initial state corrections and QCD contributions
are included. Fermions are taken to be massless, allowing a very fast
evaluation of the matrix element. A systematic, modular and self-optimizing
strategy has been adopted for the Monte Carlo integration, that serves also as
an example for further event generators in high energy particle physics.
| [
{
"created": "Thu, 15 Sep 1994 19:04:56 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Berends",
"F.",
""
],
[
"R",
"",
""
],
[
"Kleiss",
"",
""
],
[
"Pittau",
"R.",
""
]
] | A Monte Carlo program is presented that computes all four fermion processes in $e^+ e^-$ annihilation. QED initial state corrections and QCD contributions are included. Fermions are taken to be massless, allowing a very fast evaluation of the matrix element. A systematic, modular and self-optimizing strategy has been adopted for the Monte Carlo integration, that serves also as an example for further event generators in high energy particle physics. |
1507.02229 | Joan Sola | Joan Sol\`a | Fundamental Constants in Physics and Their Time Variation | 6 pages. Preface to the Special Issue on Fundamental Constants in
Physics and Their Time Variation. Typo corrected | Modern Physics Letters A Vol. 30, No. 22 (2015) 1502004 | 10.1142/S0217732315020046 | null | hep-ph astro-ph.CO gr-qc hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | There is no doubt that the field of Fundamental Constants in Physics and
Their Time Variation is one of the hottest subjects in modern theoretical and
experimental physics, with potential implications in all fundamental areas of
physics research, such as particle physics, gravitation, astrophysics and
cosmology. In this Special Issue, the state-of-the-art in the field is
presented in detail.
| [
{
"created": "Wed, 8 Jul 2015 17:18:23 GMT",
"version": "v1"
},
{
"created": "Sun, 12 Jul 2015 21:26:03 GMT",
"version": "v2"
}
] | 2015-07-14 | [
[
"Solà",
"Joan",
""
]
] | There is no doubt that the field of Fundamental Constants in Physics and Their Time Variation is one of the hottest subjects in modern theoretical and experimental physics, with potential implications in all fundamental areas of physics research, such as particle physics, gravitation, astrophysics and cosmology. In this Special Issue, the state-of-the-art in the field is presented in detail. |
hep-ph/0606286 | Alexei Prokudin | M. Anselmino, M. Boglione, A. Prokudin, C. Turk | Semi-Inclusive Deep Inelastic Scattering processes from small to large
P_T | 14 pages, 17 figures, uses revtex4 | Eur.Phys.J.A31:373-381,2007 | 10.1140/epja/i2007-10003-9 | null | hep-ph | null | We consider the azimuthal and $P_T$ dependence of hadrons produced in
unpolarized Semi-Inclusive Deep Inelastic Scattering (SIDIS) processes, within
the factorized QCD parton model. It is shown that at small $P_T$ values, $P_T
\lsim 1$ GeV/c, lowest order contributions, coupled to unintegrated (Transverse
Momentum Dependent) quark distribution and fragmentation functions, describe
all data. At larger $P_T$ values, $P_T \gsim 1$ GeV/c, the usual pQCD higher
order collinear contributions dominate. Having explained the full $P_T$ range
of available data, we give new detailed predictions concerning the azimuthal
and $P_T$ dependence of hadrons which could be measured in ongoing or planned
experiments by HERMES, COMPASS and JLab collaborations.
| [
{
"created": "Wed, 28 Jun 2006 13:32:12 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Anselmino",
"M.",
""
],
[
"Boglione",
"M.",
""
],
[
"Prokudin",
"A.",
""
],
[
"Turk",
"C.",
""
]
] | We consider the azimuthal and $P_T$ dependence of hadrons produced in unpolarized Semi-Inclusive Deep Inelastic Scattering (SIDIS) processes, within the factorized QCD parton model. It is shown that at small $P_T$ values, $P_T \lsim 1$ GeV/c, lowest order contributions, coupled to unintegrated (Transverse Momentum Dependent) quark distribution and fragmentation functions, describe all data. At larger $P_T$ values, $P_T \gsim 1$ GeV/c, the usual pQCD higher order collinear contributions dominate. Having explained the full $P_T$ range of available data, we give new detailed predictions concerning the azimuthal and $P_T$ dependence of hadrons which could be measured in ongoing or planned experiments by HERMES, COMPASS and JLab collaborations. |
1007.4984 | Guido Montagna Prof | L. Barze', G. Balossini, C. Bignamini, C.M. Carloni Calame, G.
Montagna, O. Nicrosini and F. Piccinini | Radiative Events as a Probe of Dark Forces at GeV-Scale e+ e- Colliders | 8 pages, 9 figures. New numerical results and references added.
Revised version accepted for publication in EPJ C | Eur.Phys.J.C71:1680,2011 | 10.1140/epjc/s10052-011-1680-8 | FNT/T 2010/01 | hep-ph astro-ph.HE hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | High-luminosity e+ e- colliders at the GeV scale (flavor factories) have been
recently recognized to be an ideal environment to search for a light weakly
coupled vector boson U (dark photon) emerging in several new physics models
able to interpret anomalous astrophysical observations in terms of dark matter.
At flavor factories a particularly clean channel is the production of the U
boson in association with a photon, followed by the decay of the U boson into
lepton pairs. Beyond the approximations addressed in previous works, we revisit
the reach potential of this channel by performing an exact lowest-order
calculation of the signal and background processes. We also include the effect
of initial and final state QED corrections neglected so far, to show how they
affect the distributions of experimental interest. We present new results for
the expected statistical significance to a dark photon signal at KLOE/KLOE-2
and future super-B factories. The calculation is implemented in a new release
of the event generator BabaYaga@NLO, which is available for full event
simulations and data analysis.
| [
{
"created": "Wed, 28 Jul 2010 14:09:58 GMT",
"version": "v1"
},
{
"created": "Mon, 13 Jun 2011 15:58:28 GMT",
"version": "v2"
}
] | 2011-06-28 | [
[
"Barze'",
"L.",
""
],
[
"Balossini",
"G.",
""
],
[
"Bignamini",
"C.",
""
],
[
"Calame",
"C. M. Carloni",
""
],
[
"Montagna",
"G.",
""
],
[
"Nicrosini",
"O.",
""
],
[
"Piccinini",
"F.",
""
]
] | High-luminosity e+ e- colliders at the GeV scale (flavor factories) have been recently recognized to be an ideal environment to search for a light weakly coupled vector boson U (dark photon) emerging in several new physics models able to interpret anomalous astrophysical observations in terms of dark matter. At flavor factories a particularly clean channel is the production of the U boson in association with a photon, followed by the decay of the U boson into lepton pairs. Beyond the approximations addressed in previous works, we revisit the reach potential of this channel by performing an exact lowest-order calculation of the signal and background processes. We also include the effect of initial and final state QED corrections neglected so far, to show how they affect the distributions of experimental interest. We present new results for the expected statistical significance to a dark photon signal at KLOE/KLOE-2 and future super-B factories. The calculation is implemented in a new release of the event generator BabaYaga@NLO, which is available for full event simulations and data analysis. |
1507.06926 | Arsham Farzinnia | Arsham Farzinnia | Prospects for Discovering the Higgs-like Pseudo-Nambu-Goldstone Boson of
the Classical Scale Symmetry | 17 pages, 6 figures. Fig. 6 added, typos corrected, published version | Phys. Rev. D 92, 095012 (2015) | 10.1103/PhysRevD.92.095012 | CTPU-15-10 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We examine the impact of the expected reach of the LHC and the XENON1T
experiments on the parameter space of the minimal classically scale invariant
extension of the standard model (SM), where all the mass scales are induced
dynamically by means of the Coleman-Weinberg mechanism. In this framework, the
SM content is enlarged by the addition of one complex gauge singlet scalar with
a scale invariant and $CP$-symmetric potential. The massive pseudoscalar
component, protected by the $CP$-symmetry, forms a viable dark matter
candidate, and three flavors of the right-handed Majorana neutrinos are
included to account for the nonzero masses of the SM neutrinos via the see-saw
mechanism. The projected constraints on the parameter space arise by applying
the ATLAS heavy Higgs discovery prospects, with an integrated luminosity of 300
and 3000~fb$^{-1}$ at $\sqrt s = 14$~TeV, to the pseudo-Nambu-Goldstone boson
of the (approximate) scale symmetry, as well as by utilizing the expected reach
of the XENON1T direct detection experiment for the discovery of the
pseudoscalar dark matter candidate. A null-signal discovery by these future
experiments implies that vast regions of the model's parameter space can be
thoroughly explored; the combined projections are expected to confine a mixing
between the SM and the singlet sector to very small values, while probing the
viability of the TeV~scale pseudoscalar's thermal relic abundance as the
dominant dark matter component in the Universe. Furthermore, the vacuum
stability and triviality requirements of the framework up to the Planck scale
are studied and the viable region of the parameter space is identified. The
results are summarized in extensive exclusion plots, incorporating additionally
the prior theoretical and experimental bounds for comparison.
| [
{
"created": "Fri, 24 Jul 2015 17:32:59 GMT",
"version": "v1"
},
{
"created": "Wed, 30 Dec 2015 10:49:45 GMT",
"version": "v2"
}
] | 2015-12-31 | [
[
"Farzinnia",
"Arsham",
""
]
] | We examine the impact of the expected reach of the LHC and the XENON1T experiments on the parameter space of the minimal classically scale invariant extension of the standard model (SM), where all the mass scales are induced dynamically by means of the Coleman-Weinberg mechanism. In this framework, the SM content is enlarged by the addition of one complex gauge singlet scalar with a scale invariant and $CP$-symmetric potential. The massive pseudoscalar component, protected by the $CP$-symmetry, forms a viable dark matter candidate, and three flavors of the right-handed Majorana neutrinos are included to account for the nonzero masses of the SM neutrinos via the see-saw mechanism. The projected constraints on the parameter space arise by applying the ATLAS heavy Higgs discovery prospects, with an integrated luminosity of 300 and 3000~fb$^{-1}$ at $\sqrt s = 14$~TeV, to the pseudo-Nambu-Goldstone boson of the (approximate) scale symmetry, as well as by utilizing the expected reach of the XENON1T direct detection experiment for the discovery of the pseudoscalar dark matter candidate. A null-signal discovery by these future experiments implies that vast regions of the model's parameter space can be thoroughly explored; the combined projections are expected to confine a mixing between the SM and the singlet sector to very small values, while probing the viability of the TeV~scale pseudoscalar's thermal relic abundance as the dominant dark matter component in the Universe. Furthermore, the vacuum stability and triviality requirements of the framework up to the Planck scale are studied and the viable region of the parameter space is identified. The results are summarized in extensive exclusion plots, incorporating additionally the prior theoretical and experimental bounds for comparison. |
hep-ph/0607207 | Hai-Xia Zhang | H. X. Zhang, W. L. Wang, Y.-B. Dai and Z. Y. Zhang | Chiral SU(3) Quark Model Study of Tetraquark States: $cn\bar{n}\bar{s} /
cs\bar{s}\bar{s}$ | 20 pages | Commun.Theor.Phys.49:414-420,2008 | 10.1088/0253-6102/49/2/35 | null | hep-ph | null | The new members of the charm-strange family $D_{sJ}^{*}(2317)$,
$D_{sJ}(2460)$ and $D_s(2632)$, which have the surprising properties, are
challenging the present models. Many theoretical interpretations have been
devoted to this issue. Most of authors suggest that they are not the
conventional $c\bar s$ quark model states, but possibly are four-quark states,
molecule states or mixtures of a P-wave $c\bar s$ and a four-quark state. In
this work, we follow the four-quark-state picture, and study the masses of
$cn\bar n\bar s/cs\bar s\bar s$ states ($n$ is $u$ or $d$ quark) in the chiral
SU(3) quark model. The numerical results show that the mass of the mixed
four-quark state ($cn\bar n\bar s/cs\bar s\bar s$) with spin parity $J^P=0^{+}$
might not be $D_s(2632)$. At the same time, we also conclude that
$D_{sJ}^{*}(2317)$ and $D_{sJ}(2460)$ cannot be explained as the pure
four-quark state.
| [
{
"created": "Wed, 19 Jul 2006 09:07:47 GMT",
"version": "v1"
},
{
"created": "Tue, 5 Dec 2006 09:46:01 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Zhang",
"H. X.",
""
],
[
"Wang",
"W. L.",
""
],
[
"Dai",
"Y. -B.",
""
],
[
"Zhang",
"Z. Y.",
""
]
] | The new members of the charm-strange family $D_{sJ}^{*}(2317)$, $D_{sJ}(2460)$ and $D_s(2632)$, which have the surprising properties, are challenging the present models. Many theoretical interpretations have been devoted to this issue. Most of authors suggest that they are not the conventional $c\bar s$ quark model states, but possibly are four-quark states, molecule states or mixtures of a P-wave $c\bar s$ and a four-quark state. In this work, we follow the four-quark-state picture, and study the masses of $cn\bar n\bar s/cs\bar s\bar s$ states ($n$ is $u$ or $d$ quark) in the chiral SU(3) quark model. The numerical results show that the mass of the mixed four-quark state ($cn\bar n\bar s/cs\bar s\bar s$) with spin parity $J^P=0^{+}$ might not be $D_s(2632)$. At the same time, we also conclude that $D_{sJ}^{*}(2317)$ and $D_{sJ}(2460)$ cannot be explained as the pure four-quark state. |
1805.03636 | Jaume Guasch | Jorge Alda, Jaume Guasch, Siannah Pe\~naranda | Some results on Lepton Flavour Universality Violation | LaTeX, 16 pages, 6 figures, 4 tables. Analysis extended and updated.
Comments and discussions added, references added, two new figures added.
Conclusions unchanged. Version to appear in Eur. Phys. J. C | null | 10.1140/epjc/s10052-019-7092-x | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Motivated by recent experimental measurements on flavour physics, in tension
with Standard Model predictions, we perform an updated analysis of New Physics
violating Lepton Flavour Universality, by using the effective Lagrangian
approach and in the Z' and S_3 leptoquark models. We explicitly analyze the
impact of considering complex Wilson coefficients in the analysis of
B-anomalies, by performing a global fit of R_K and R_K*0 observables, together
with \Delta Ms and A_CP^mix. The inclusion of complex couplings provides a
slightly improved global fit, and a marginally improved \Delta Ms prediction.
| [
{
"created": "Wed, 9 May 2018 17:56:47 GMT",
"version": "v1"
},
{
"created": "Tue, 19 Jun 2018 09:44:57 GMT",
"version": "v2"
},
{
"created": "Tue, 9 Jul 2019 10:09:45 GMT",
"version": "v3"
}
] | 2019-09-04 | [
[
"Alda",
"Jorge",
""
],
[
"Guasch",
"Jaume",
""
],
[
"Peñaranda",
"Siannah",
""
]
] | Motivated by recent experimental measurements on flavour physics, in tension with Standard Model predictions, we perform an updated analysis of New Physics violating Lepton Flavour Universality, by using the effective Lagrangian approach and in the Z' and S_3 leptoquark models. We explicitly analyze the impact of considering complex Wilson coefficients in the analysis of B-anomalies, by performing a global fit of R_K and R_K*0 observables, together with \Delta Ms and A_CP^mix. The inclusion of complex couplings provides a slightly improved global fit, and a marginally improved \Delta Ms prediction. |
1102.3301 | Kwang Sik Jeong | Kwang Sik Jeong, Masahiro Yamaguchi | Axion model in gauge-mediated supersymmetry breaking and a solution to
the mu/Bmu problem | 28 pages, 2 figures; references added | JHEP 1107:124,2011 | 10.1007/JHEP07(2011)124 | TU-879 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a simple supersymmetric axion model that can naturally explain the
origin of the Higgs mu and Bmu terms in gauge mediation while solving the
strong CP problem. To stabilize the Peccei-Quinn scale, we consider mixing
between the messenger fields that communicate the supersymmetry and
Peccei-Quinn symmetry breaking to the visible sector. Such mixing leads to the
radiative stabilization of the Peccei-Quinn scale. In the model, a Higgs
coupling to the axion superfield generates the B parameter at the soft mass
scale while a small mu term is induced after the Peccei-Quinn symmetry
breaking. We also explore the phenomenological and cosmological aspects of the
model, which crucially depend on the saxion and axino interactions with the
ordinary particles induced by the Higgs coupling to the axion superfield.
| [
{
"created": "Wed, 16 Feb 2011 11:06:46 GMT",
"version": "v1"
},
{
"created": "Fri, 25 Feb 2011 12:18:52 GMT",
"version": "v2"
},
{
"created": "Mon, 25 Apr 2011 19:19:14 GMT",
"version": "v3"
},
{
"created": "Tue, 17 May 2011 14:00:58 GMT",
"version": "v4"
}
] | 2011-08-01 | [
[
"Jeong",
"Kwang Sik",
""
],
[
"Yamaguchi",
"Masahiro",
""
]
] | We present a simple supersymmetric axion model that can naturally explain the origin of the Higgs mu and Bmu terms in gauge mediation while solving the strong CP problem. To stabilize the Peccei-Quinn scale, we consider mixing between the messenger fields that communicate the supersymmetry and Peccei-Quinn symmetry breaking to the visible sector. Such mixing leads to the radiative stabilization of the Peccei-Quinn scale. In the model, a Higgs coupling to the axion superfield generates the B parameter at the soft mass scale while a small mu term is induced after the Peccei-Quinn symmetry breaking. We also explore the phenomenological and cosmological aspects of the model, which crucially depend on the saxion and axino interactions with the ordinary particles induced by the Higgs coupling to the axion superfield. |
2404.12325 | Simon Badger | Simon Badger, Matteo Becchetti, Nicol\`o Giraudo, Simone Zoia | Two-loop integrals for $t \bar{t} +$jet production at hadron colliders
in the leading colour approximation | 22 pages, 7 figures, 3 tables, 3 appendices | null | null | CERN-TH-2024-048, ZU-TH 22/24 | hep-ph hep-th | http://creativecommons.org/licenses/by/4.0/ | We compute the differential equations for the two remaining integral
topologies contributing to the leading colour two-loop amplitudes for $pp
\rightarrow t\bar{t}j$. We derive differential equations for the master
integrals by solving the integration-by-parts identities over finite fields. Of
the two systems of differential equations, one is presented in canonical '${\rm
d} \log$' form, while the other is found to have an elliptic sector. For the
elliptic topology we identify the relevant elliptic curve, and present the
differential equations in a more general form which depends quadratically on
$\epsilon$ and contains non-logarithmic one-forms in addition to the canonical
${\rm d} \log$'s. We solve the systems of differential equations numerically
using generalised series expansions with the boundary terms obtained using the
auxiliary mass flow method. A summary of all one-loop and two-loop planar
topologies is presented including the list of alphabet letters for the '${\rm
d} \log$' form systems and high-precision boundary values.
| [
{
"created": "Thu, 18 Apr 2024 16:54:05 GMT",
"version": "v1"
},
{
"created": "Mon, 29 Apr 2024 10:18:29 GMT",
"version": "v2"
},
{
"created": "Tue, 30 Apr 2024 09:06:12 GMT",
"version": "v3"
}
] | 2024-05-01 | [
[
"Badger",
"Simon",
""
],
[
"Becchetti",
"Matteo",
""
],
[
"Giraudo",
"Nicolò",
""
],
[
"Zoia",
"Simone",
""
]
] | We compute the differential equations for the two remaining integral topologies contributing to the leading colour two-loop amplitudes for $pp \rightarrow t\bar{t}j$. We derive differential equations for the master integrals by solving the integration-by-parts identities over finite fields. Of the two systems of differential equations, one is presented in canonical '${\rm d} \log$' form, while the other is found to have an elliptic sector. For the elliptic topology we identify the relevant elliptic curve, and present the differential equations in a more general form which depends quadratically on $\epsilon$ and contains non-logarithmic one-forms in addition to the canonical ${\rm d} \log$'s. We solve the systems of differential equations numerically using generalised series expansions with the boundary terms obtained using the auxiliary mass flow method. A summary of all one-loop and two-loop planar topologies is presented including the list of alphabet letters for the '${\rm d} \log$' form systems and high-precision boundary values. |
hep-ph/0102160 | Ulrich Baur | Arie Bodek (Rochester) and Ulrich Baur (Buffalo) | Implications of a 300-500 GeV/c^2 Z' boson on p\bar{p} collider data at
\sqrt{s}=1.8 TeV | 4 pages, revtex, 3 postscript figures, 2 tables, to be submitted for
publication, further corrections to references | Eur.Phys.J.C21:607-611,2001 | 10.1007/s100520100778 | UR-1617, UB-HET-01-02 | hep-ph hep-ex | null | Recent analyses of precision low energy electroweak data indicate that the
deviation from the Standard Model predictions of the measurement of atomic
parity violation (2.3\sigma), the effective number of massless neutrinos
(2\sigma), and A_b (2.7\sigma) could be better described if the existence of an
extra Z' neutral gauge boson is assumed. We investigate the implications of a
300-500 GeV/c^2 extra Z' on current p\bar{p} collider data at \sqrt{s}=1.8 TeV,
including the forward-backward charge asymmetry for very high mass e^+e^-
pairs, and the invariant mass spectrum of high mass e^+e^-, \mu^+\mu^-, t\bar t
and b\bar b pairs. For example, a 500 GeV/c^2 Z' with a total production cross
section of \approx 3 pb and enhanced coupling to the third generation, better
describes both the low energy and the Tevatron data.
| [
{
"created": "Wed, 14 Feb 2001 01:21:11 GMT",
"version": "v1"
},
{
"created": "Thu, 15 Feb 2001 20:45:11 GMT",
"version": "v2"
},
{
"created": "Sun, 18 Feb 2001 18:38:08 GMT",
"version": "v3"
}
] | 2011-03-23 | [
[
"Bodek",
"Arie",
"",
"Rochester"
],
[
"Baur",
"Ulrich",
"",
"Buffalo"
]
] | Recent analyses of precision low energy electroweak data indicate that the deviation from the Standard Model predictions of the measurement of atomic parity violation (2.3\sigma), the effective number of massless neutrinos (2\sigma), and A_b (2.7\sigma) could be better described if the existence of an extra Z' neutral gauge boson is assumed. We investigate the implications of a 300-500 GeV/c^2 extra Z' on current p\bar{p} collider data at \sqrt{s}=1.8 TeV, including the forward-backward charge asymmetry for very high mass e^+e^- pairs, and the invariant mass spectrum of high mass e^+e^-, \mu^+\mu^-, t\bar t and b\bar b pairs. For example, a 500 GeV/c^2 Z' with a total production cross section of \approx 3 pb and enhanced coupling to the third generation, better describes both the low energy and the Tevatron data. |
2401.02874 | Deeptak Biswas | Deeptak Biswas, Peter Petreczky and Sayantan Sharma | Chiral condensate and the equation of state at nonzero baryon density
from the hadron resonance gas model with a repulsive mean field | Matched with published version | Phys. Rev. C 109, 055206, 2024 | 10.1103/PhysRevC.109.055206 | null | hep-ph hep-lat nucl-th | http://creativecommons.org/licenses/by/4.0/ | We study the QCD equation of state and the chiral condensate using the hadron
resonance gas model with repulsive mean-field interactions. We find that the
repulsive interactions improve the agreement with the lattice results on the
derivatives of the pressure with respect to the baryon chemical potential up to
eighth order. From the temperature dependence of the chiral condensate we
estimate the crossover temperature as a function of baryon chemical potential,
$T_{pc}(\mu_B)$. We find that the chiral crossover line starts to deviate
significantly from the chemical freeze-out line already for $\mu_B>400$ MeV.
Furthermore, we find that the chiral pseudocritical line can be parametrized as
$T_{pc}(\mu_B)/T_{pc}(0)=1-\kappa_2 (\mu_B/T_{pc} (0))^2-\kappa_4 (\mu_B/T_{pc}
(0))^4$ with $\kappa_2=0.0150(2)$ and $\kappa_4=3.1(6) \times 10^{-5}$, which
are in agreement with lattice QCD results for small values of $\mu_B$. For the
first time we find a tiny but non-zero value of $\kappa_4$ in our study.
| [
{
"created": "Fri, 5 Jan 2024 16:05:11 GMT",
"version": "v1"
},
{
"created": "Sun, 2 Jun 2024 10:01:06 GMT",
"version": "v2"
}
] | 2024-06-04 | [
[
"Biswas",
"Deeptak",
""
],
[
"Petreczky",
"Peter",
""
],
[
"Sharma",
"Sayantan",
""
]
] | We study the QCD equation of state and the chiral condensate using the hadron resonance gas model with repulsive mean-field interactions. We find that the repulsive interactions improve the agreement with the lattice results on the derivatives of the pressure with respect to the baryon chemical potential up to eighth order. From the temperature dependence of the chiral condensate we estimate the crossover temperature as a function of baryon chemical potential, $T_{pc}(\mu_B)$. We find that the chiral crossover line starts to deviate significantly from the chemical freeze-out line already for $\mu_B>400$ MeV. Furthermore, we find that the chiral pseudocritical line can be parametrized as $T_{pc}(\mu_B)/T_{pc}(0)=1-\kappa_2 (\mu_B/T_{pc} (0))^2-\kappa_4 (\mu_B/T_{pc} (0))^4$ with $\kappa_2=0.0150(2)$ and $\kappa_4=3.1(6) \times 10^{-5}$, which are in agreement with lattice QCD results for small values of $\mu_B$. For the first time we find a tiny but non-zero value of $\kappa_4$ in our study. |
1306.2657 | Antal Jakovac | A. Jakovac | Hadron melting and QCD thermodynamics | 10 pages, 12 figures, revtex4 | null | 10.1103/PhysRevD.88.065012 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study in this paper mechanisms of hadron melting based on the spectral
representation of hadronic quantum channels, and examine the hadron width
dependence of the pressure. The findings are applied to a statistical hadron
model of QCD thermodynamics, where hadron masses are distributed by the
Hagedorn model and a uniform mechanism for producing hadron widths is assumed.
According to this model the hadron - quark gluon plasma transition occurs at
$T\approx 200$-250 MeV, the numerically observable $T_c=156$ MeV crossover
temperature is relevant for the onset of the hadron melting process.
| [
{
"created": "Tue, 11 Jun 2013 20:47:20 GMT",
"version": "v1"
}
] | 2013-09-18 | [
[
"Jakovac",
"A.",
""
]
] | We study in this paper mechanisms of hadron melting based on the spectral representation of hadronic quantum channels, and examine the hadron width dependence of the pressure. The findings are applied to a statistical hadron model of QCD thermodynamics, where hadron masses are distributed by the Hagedorn model and a uniform mechanism for producing hadron widths is assumed. According to this model the hadron - quark gluon plasma transition occurs at $T\approx 200$-250 MeV, the numerically observable $T_c=156$ MeV crossover temperature is relevant for the onset of the hadron melting process. |
hep-ph/0404153 | Adam Bzdak | Adam Bzdak | Production of gluon jets in pp collisions by double pomeron exchange in
the Landshoff-Nachtmann model | 11 pages, 8 figures. Submitted to Acta Phys. Pol. B | Acta Phys.Polon. B35 (2004) 1733-1746 | null | null | hep-ph | null | Using the Landshoff-Nachtmann two-gluon exchange model of the pomeron, the
double pomeron exchange contribution to production of gluon pairs in the
central region of rapidity is calculated. The results are compared with those
for production of quark-antiquark pairs.
| [
{
"created": "Mon, 19 Apr 2004 13:51:59 GMT",
"version": "v1"
},
{
"created": "Tue, 27 Apr 2004 10:03:26 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Bzdak",
"Adam",
""
]
] | Using the Landshoff-Nachtmann two-gluon exchange model of the pomeron, the double pomeron exchange contribution to production of gluon pairs in the central region of rapidity is calculated. The results are compared with those for production of quark-antiquark pairs. |
0812.0529 | Peter Richardson | M. Bahr, S. Gieseke, M. Gigg, D. Grellscheid, K. Hamilton, S. Platzer,
P. Richardson, M.H. Seymour, J. Tully | Herwig++ 2.3 Release Note | Program and additional information available from
http://projects.hepforge.org/herwig/ | null | null | CERN-PH-TH/2008-213, CP3-08-51, IPPP/08/75, DCPT/08/150,
KA-TP-27-2008 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A new release of the Monte Carlo program Herwig++ (version 2.3) is now
available. This version includes a number of improvements including: the
extension of the program to lepton-hadron collisions; the inclusion of several
processes accurate at next-to-leading order in the POsitive Weight Hardest
Emission Generator (POWHEG) scheme; the inclusion of three-body decays and
finite-width effects in Beyond the Standard Model (BSM) physics processes; a
new procedure for reconstructing the kinematics of the parton shower based on
the colour structure of the hard scattering process; a new model for baryon
decays including excited baryon multiplets; the addition of a soft component to
the multiple scattering model of the underlying event; new matrix elements for
Deep Inelastic Scattering (DIS) and e+e- processes.
| [
{
"created": "Tue, 2 Dec 2008 15:31:06 GMT",
"version": "v1"
}
] | 2008-12-03 | [
[
"Bahr",
"M.",
""
],
[
"Gieseke",
"S.",
""
],
[
"Gigg",
"M.",
""
],
[
"Grellscheid",
"D.",
""
],
[
"Hamilton",
"K.",
""
],
[
"Platzer",
"S.",
""
],
[
"Richardson",
"P.",
""
],
[
"Seymour",
"M. H.",
""
],
[
"Tully",
"J.",
""
]
] | A new release of the Monte Carlo program Herwig++ (version 2.3) is now available. This version includes a number of improvements including: the extension of the program to lepton-hadron collisions; the inclusion of several processes accurate at next-to-leading order in the POsitive Weight Hardest Emission Generator (POWHEG) scheme; the inclusion of three-body decays and finite-width effects in Beyond the Standard Model (BSM) physics processes; a new procedure for reconstructing the kinematics of the parton shower based on the colour structure of the hard scattering process; a new model for baryon decays including excited baryon multiplets; the addition of a soft component to the multiple scattering model of the underlying event; new matrix elements for Deep Inelastic Scattering (DIS) and e+e- processes. |
1703.05791 | Bijan Chokoufe Nejad | J\"urgen Reuter, Bijan Chokoufe Nejad, Christian Weiss | NLO QCD Corrections to Off-shell $t\,\bar{t}$ and $t\,\bar{t}\,H$ at the
ILC | 12 page, 4 figures, Talk presented at the International Workshop on
Future Linear Colliders (LCWS2016), Morioka, Japan, 5-9 December 2016.
C16-12-05.4 | null | null | DESY 17-041 | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | We discuss top-quark physics at the ILC with a focus on the full off-shell
processes for $t\bar{t}$ and $t\bar{t}H$ production, including top-quark decays
and also leptonic $W$ decays. A special focus is on the matching of the
resummed vNRQCD threshold calculation and the fixed-order NLO QCD continuum
calculation, where we present an update on the validation of the matching. All
of the calculations have been performed in the \wz event generator framework.
| [
{
"created": "Thu, 16 Mar 2017 18:48:32 GMT",
"version": "v1"
}
] | 2017-03-20 | [
[
"Reuter",
"Jürgen",
""
],
[
"Nejad",
"Bijan Chokoufe",
""
],
[
"Weiss",
"Christian",
""
]
] | We discuss top-quark physics at the ILC with a focus on the full off-shell processes for $t\bar{t}$ and $t\bar{t}H$ production, including top-quark decays and also leptonic $W$ decays. A special focus is on the matching of the resummed vNRQCD threshold calculation and the fixed-order NLO QCD continuum calculation, where we present an update on the validation of the matching. All of the calculations have been performed in the \wz event generator framework. |
2212.06163 | Joe Davighi | Joe Davighi, Gino Isidori, Marko Pesut | Electroweak-flavour and quark-lepton unification: a family non-universal
path | 34 pages. Minor modifications of the phenomenological discussion in
view of new results on RK(*), which reinforce the consistency of the model | null | 10.1007/JHEP04(2023)030 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a family-non-universal extension of the Standard Model where the
the first two families feature both quark-lepton and electroweak-flavour
unification, via the $SU(4) \times Sp(4)_L \times Sp(4)_R$ gauge group, whereas
quark-lepton unification for the third family is realised \`a la Pati-Salam.
Via staggered symmetry breaking steps, this construction offers a natural
explanation for the observed hierarchical pattern of fermion masses and
mixings, while providing a natural suppression for flavour-changing processes
involving the first two generations. The last-but-one step in the
symmetry-breaking chain is a non-universal 4321 model, characterised by a
vector leptoquark naturally coupled mainly to the third generation. The
stability of the Higgs sector points to a 4321$\to$SM symmetry-breaking scale
around the TeV, with interesting phenomenological consequences in $B$ physics
and collider processes that differ from those of other known 4321 completions.
| [
{
"created": "Mon, 12 Dec 2022 19:00:01 GMT",
"version": "v1"
},
{
"created": "Thu, 5 Jan 2023 14:53:34 GMT",
"version": "v2"
}
] | 2023-04-26 | [
[
"Davighi",
"Joe",
""
],
[
"Isidori",
"Gino",
""
],
[
"Pesut",
"Marko",
""
]
] | We present a family-non-universal extension of the Standard Model where the the first two families feature both quark-lepton and electroweak-flavour unification, via the $SU(4) \times Sp(4)_L \times Sp(4)_R$ gauge group, whereas quark-lepton unification for the third family is realised \`a la Pati-Salam. Via staggered symmetry breaking steps, this construction offers a natural explanation for the observed hierarchical pattern of fermion masses and mixings, while providing a natural suppression for flavour-changing processes involving the first two generations. The last-but-one step in the symmetry-breaking chain is a non-universal 4321 model, characterised by a vector leptoquark naturally coupled mainly to the third generation. The stability of the Higgs sector points to a 4321$\to$SM symmetry-breaking scale around the TeV, with interesting phenomenological consequences in $B$ physics and collider processes that differ from those of other known 4321 completions. |
1502.01361 | Christian Gross | Adam Falkowski, Christian Gross, Oleg Lebedev | A second Higgs from the Higgs portal | 16 pages, updated figures 3 and 4 with new limits from Higgs-searches
at the LHC, minor text adjustments, references added | null | 10.1007/JHEP05(2015)057 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the Higgs portal framework, the Higgs field generally mixes with the
Standard Model singlet leading to the existence of two states, one of which is
identified with the 125 GeV scalar observed at the LHC. In this work, we
analyse direct and indirect constraints on the second mass eigenstate and the
corresponding mixing angle. The existence of the additional scalar can be
beneficial as it can stabilise the otherwise-metastable electroweak vacuum. We
find parameter regions where all of the bounds, including the stability
constraints, are satisfied. We also study prospects for observing the decay of
the heavier state into a pair of the 125 GeV Higgs-like scalars.
| [
{
"created": "Wed, 4 Feb 2015 21:21:31 GMT",
"version": "v1"
},
{
"created": "Wed, 18 Feb 2015 15:53:08 GMT",
"version": "v2"
},
{
"created": "Wed, 15 Apr 2015 13:22:06 GMT",
"version": "v3"
}
] | 2015-06-11 | [
[
"Falkowski",
"Adam",
""
],
[
"Gross",
"Christian",
""
],
[
"Lebedev",
"Oleg",
""
]
] | In the Higgs portal framework, the Higgs field generally mixes with the Standard Model singlet leading to the existence of two states, one of which is identified with the 125 GeV scalar observed at the LHC. In this work, we analyse direct and indirect constraints on the second mass eigenstate and the corresponding mixing angle. The existence of the additional scalar can be beneficial as it can stabilise the otherwise-metastable electroweak vacuum. We find parameter regions where all of the bounds, including the stability constraints, are satisfied. We also study prospects for observing the decay of the heavier state into a pair of the 125 GeV Higgs-like scalars. |
hep-ph/0701007 | Torsten Bringmann | Francesca Borzumati, Torsten Bringmann, Piero Ullio | Dark matter from late decays and the small-scale structure problems | Small changes, matches the published version | Phys.Rev.D77:063514,2008 | 10.1103/PhysRevD.77.063514 | null | hep-ph astro-ph | null | The generation of dark matter in late decays of quasi-stable massive
particles has been proposed as a viable framework to address the excess of
power found in numerical N-body simulations for cold dark matter cosmologies.
We identify a convenient set of variables to illustrate which requirements need
to be satisfied in any generic particle physics model to address the small
scale problems and to fulfill other astrophysical constraints. As a result of
this model-independent analysis, we point out that meeting these requirements
in a completely natural way is inherently difficult. In particular, we
re-examine the role of gravitinos and Kaluza-Klein gravitons in this context
and find them disfavoured as a solution to the small-scale problems in case
they are DM candidates generated in the decay of thermally produced WIMPs. We
propose right-handed sneutrinos and right-handed Kaluza-Klein neutrinos as
alternatives. We find that they are viable dark matter candidates, but that
they can contribute to a solution of the small scale problems only in case the
associated Dirac neutrino mass term appears as a subdominant contribution in
the neutrino mass matrix.
| [
{
"created": "Sun, 31 Dec 2006 17:41:18 GMT",
"version": "v1"
},
{
"created": "Fri, 14 Mar 2008 13:43:16 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Borzumati",
"Francesca",
""
],
[
"Bringmann",
"Torsten",
""
],
[
"Ullio",
"Piero",
""
]
] | The generation of dark matter in late decays of quasi-stable massive particles has been proposed as a viable framework to address the excess of power found in numerical N-body simulations for cold dark matter cosmologies. We identify a convenient set of variables to illustrate which requirements need to be satisfied in any generic particle physics model to address the small scale problems and to fulfill other astrophysical constraints. As a result of this model-independent analysis, we point out that meeting these requirements in a completely natural way is inherently difficult. In particular, we re-examine the role of gravitinos and Kaluza-Klein gravitons in this context and find them disfavoured as a solution to the small-scale problems in case they are DM candidates generated in the decay of thermally produced WIMPs. We propose right-handed sneutrinos and right-handed Kaluza-Klein neutrinos as alternatives. We find that they are viable dark matter candidates, but that they can contribute to a solution of the small scale problems only in case the associated Dirac neutrino mass term appears as a subdominant contribution in the neutrino mass matrix. |
hep-ph/9610381 | Adam Leibovich | Adam K. Leibovich | $\psi'$ Polarization due to Color-Octet Quarkonia Production | 10 pages revtex, uses epsf, some formulae corrected | Phys. Rev. D 56, 4412 (1997) | 10.1103/PhysRevD.56.4412 | CALT-68-2082 | hep-ph | null | We calculated the polarization of \psi' due to gg \to Q\bar{Q}[^3P_J^(8)]g
\to \psi^\lambda color-octet quarkonia production. We find that at low
transverse momenta the \psi' is unpolarized due to the contributions
proportional to the L=S=0 and L=S=1 color-octet matrix elements. As p_\perp
increases, the \psi' mesons become 100% polarized, as predicted by
fragmentation calculations. Polarization due to lowest order color-singlet
production is also considered, which qualitatively has a similar shape to the
color-octet production.
| [
{
"created": "Wed, 16 Oct 1996 20:06:56 GMT",
"version": "v1"
},
{
"created": "Fri, 25 Apr 1997 20:46:07 GMT",
"version": "v2"
}
] | 2016-08-25 | [
[
"Leibovich",
"Adam K.",
""
]
] | We calculated the polarization of \psi' due to gg \to Q\bar{Q}[^3P_J^(8)]g \to \psi^\lambda color-octet quarkonia production. We find that at low transverse momenta the \psi' is unpolarized due to the contributions proportional to the L=S=0 and L=S=1 color-octet matrix elements. As p_\perp increases, the \psi' mesons become 100% polarized, as predicted by fragmentation calculations. Polarization due to lowest order color-singlet production is also considered, which qualitatively has a similar shape to the color-octet production. |
hep-ph/9707309 | Zoltan Trocsanyi | Zolt\'an Nagy and Zolt\'an Tr\'ocs\'anyi | Next-to-Leading Order Calculation of Four-Jet Shape Variables | 11 pages, latex with aps, epsf, rotate styles 3 tables, 3 figures
typo in eq. 10 corrected, note and reference added, introduction revised | Phys.Rev.Lett. 79 (1997) 3604-3607 | 10.1103/PhysRevLett.79.3604 | null | hep-ph | null | We present the next-to-leading order calculation of two four-jet event shape
variables, the D parameter and acoplanarity differential distributions. We find
large, more than 100% radiative corrections. The theoretical prediction for the
D parameter is compared to L3 data obtained at the Z peak and corrected to
hadron level.
| [
{
"created": "Thu, 10 Jul 1997 19:00:57 GMT",
"version": "v1"
},
{
"created": "Mon, 22 Dec 1997 17:22:21 GMT",
"version": "v2"
}
] | 2009-10-30 | [
[
"Nagy",
"Zoltán",
""
],
[
"Trócsányi",
"Zoltán",
""
]
] | We present the next-to-leading order calculation of two four-jet event shape variables, the D parameter and acoplanarity differential distributions. We find large, more than 100% radiative corrections. The theoretical prediction for the D parameter is compared to L3 data obtained at the Z peak and corrected to hadron level. |
hep-ph/0505152 | D. Toublan | A. Tawfik and D. Toublan | Quark-Antiquark Condensates in the Hadronic Phase | 5 pages, 7 figures | Phys.Lett. B623 (2005) 48-54 | 10.1016/j.physletb.2005.07.025 | null | hep-ph hep-lat nucl-th | null | We use a hadron resonance gas model to calculate the quark-antiquark
condensates for light (up and down) and strange quark flavors at finite
temperatures and chemical potentials. At zero chemical potentials, we find that
at the temperature where the light quark-antiquark condensates entirely vanish
the strange quark-antiquark condensate still keeps a relatively large fraction
of its value in the vacuum. This is in agreement with results obtained in
lattice simulations and in chiral perturbation theory at finite temperature and
zero chemical potentials. Furthermore, we find that this effect slowly
disappears at larger baryon chemical potential. These results might have
significant consequences for our understanding of QCD at finite temperatures
and chemical potentials. Concretely, our results imply that there might be a
domain of temperatures where chiral symmetry is restored for light quarks, but
still broken for strange quark that persists at small chemical potentials. This
might have practical consequences for heavy ion collision experiments.
| [
{
"created": "Tue, 17 May 2005 19:03:59 GMT",
"version": "v1"
}
] | 2009-11-11 | [
[
"Tawfik",
"A.",
""
],
[
"Toublan",
"D.",
""
]
] | We use a hadron resonance gas model to calculate the quark-antiquark condensates for light (up and down) and strange quark flavors at finite temperatures and chemical potentials. At zero chemical potentials, we find that at the temperature where the light quark-antiquark condensates entirely vanish the strange quark-antiquark condensate still keeps a relatively large fraction of its value in the vacuum. This is in agreement with results obtained in lattice simulations and in chiral perturbation theory at finite temperature and zero chemical potentials. Furthermore, we find that this effect slowly disappears at larger baryon chemical potential. These results might have significant consequences for our understanding of QCD at finite temperatures and chemical potentials. Concretely, our results imply that there might be a domain of temperatures where chiral symmetry is restored for light quarks, but still broken for strange quark that persists at small chemical potentials. This might have practical consequences for heavy ion collision experiments. |
1504.00111 | Rahul Srivastava | Ernest Ma, Rahul Srivastava | Dirac or Inverse Seesaw Neutrino Masses from Gauged B - L Symmetry | 12 Pages, Contribution to the proceedings of International Conference
on Massive Neutrinos - 2015 | null | 10.1142/S0217732315300207 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The gauged $B - L$ symmetry is one of the simplest and well studied extension
of standard model. In the conventional case, addition of three singlet right
handed neutrinos each transforming as $-1$ under the $B - L$ symmetry renders
it anomaly free. It is usually assumed that the $B - L$ symmetry is
spontaneously broken by a singlet scalar having two units of $B - L$ charge,
resulting in a natural implementation of Majorana seesaw mechanism for
neutrinos. However, as we discuss in this proceeding, there is another simple
anomaly free solution which leads to Dirac or inverse seesaw masses for
neutrinos. These new possibilities are explored along with an application to
neutrino mixing with $S_3$ flavour symmetry.
| [
{
"created": "Wed, 1 Apr 2015 06:06:15 GMT",
"version": "v1"
}
] | 2015-09-02 | [
[
"Ma",
"Ernest",
""
],
[
"Srivastava",
"Rahul",
""
]
] | The gauged $B - L$ symmetry is one of the simplest and well studied extension of standard model. In the conventional case, addition of three singlet right handed neutrinos each transforming as $-1$ under the $B - L$ symmetry renders it anomaly free. It is usually assumed that the $B - L$ symmetry is spontaneously broken by a singlet scalar having two units of $B - L$ charge, resulting in a natural implementation of Majorana seesaw mechanism for neutrinos. However, as we discuss in this proceeding, there is another simple anomaly free solution which leads to Dirac or inverse seesaw masses for neutrinos. These new possibilities are explored along with an application to neutrino mixing with $S_3$ flavour symmetry. |
2110.09682 | Bowen Fu | Bowen Fu | Brief on Dark Matter in the Type Ib Seesaw Model: a GeV-scale Dirac
neutrino portal | 4 pages, 2 figures, 1 table, contribution to the conference
proceedings of EPS-HEP2021 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The type Ib seesaw, as an alternative explanation to the origin of neutrino
mass, provides a new intriguing way to connect the neutrino physics to
cosmology. In this proceeding, we consider a minimal type Ib seesaw model where
the effective neutrino mass operator involves two different Higgs doublets and
a heavy Dirac mass. We propose a minimal dark matter extension of this model,
in which the Dirac heavy neutrino is coupled to a dark Dirac fermion and a dark
complex scalar field, both odd under a discrete $Z_2$ symmetry, where the
lighter one serves as a dark matter candidate. Focussing on the fermionic dark
matter case, we explore the parameter space of the seesaw Yukawa couplings, the
neutrino portal couplings and dark scalar to dark fermion mass ratio, where
correct dark matter relic abundance can be produced by the freeze-in mechanism.
By considering the mixing between the standard model neutrinos and the heavy
neutrino, a connection can be built between dark matter production and
laboratory experiments.
| [
{
"created": "Tue, 19 Oct 2021 01:24:34 GMT",
"version": "v1"
}
] | 2021-10-20 | [
[
"Fu",
"Bowen",
""
]
] | The type Ib seesaw, as an alternative explanation to the origin of neutrino mass, provides a new intriguing way to connect the neutrino physics to cosmology. In this proceeding, we consider a minimal type Ib seesaw model where the effective neutrino mass operator involves two different Higgs doublets and a heavy Dirac mass. We propose a minimal dark matter extension of this model, in which the Dirac heavy neutrino is coupled to a dark Dirac fermion and a dark complex scalar field, both odd under a discrete $Z_2$ symmetry, where the lighter one serves as a dark matter candidate. Focussing on the fermionic dark matter case, we explore the parameter space of the seesaw Yukawa couplings, the neutrino portal couplings and dark scalar to dark fermion mass ratio, where correct dark matter relic abundance can be produced by the freeze-in mechanism. By considering the mixing between the standard model neutrinos and the heavy neutrino, a connection can be built between dark matter production and laboratory experiments. |
hep-ph/0304136 | Xue-Qian Li | Chao-Hsi Chang, Peng Guo, Xue-Qian Li and Guo-Li Wang | Non-spectator Contributions To The Lifetime of $\Lambda_{b}$ | null | Commun.Theor.Phys. 42 (2004) 723-734 | 10.1088/0253-6102/42/5/723 | null | hep-ph | null | In this work, we evaluate the contributions of non-spectator effects to the
lifetimes of $\Lambda_b$ and B-mesons. Based on the well-established models and
within a reasonable range of the concerned parameters, the contributions can
reduce the lifetime of $\Lambda_b$ by $7 \sim 8%$ compared to that of B-mesons
which are not significantly affected. This might partly explain the measured
ratio $\tau(\Lambda_{b})/\tau(B^{0})=0.79 $ \cite{Data}, which has been a
long-standing discrepancy between theory and experimental data.
| [
{
"created": "Tue, 15 Apr 2003 01:31:30 GMT",
"version": "v1"
}
] | 2018-01-17 | [
[
"Chang",
"Chao-Hsi",
""
],
[
"Guo",
"Peng",
""
],
[
"Li",
"Xue-Qian",
""
],
[
"Wang",
"Guo-Li",
""
]
] | In this work, we evaluate the contributions of non-spectator effects to the lifetimes of $\Lambda_b$ and B-mesons. Based on the well-established models and within a reasonable range of the concerned parameters, the contributions can reduce the lifetime of $\Lambda_b$ by $7 \sim 8%$ compared to that of B-mesons which are not significantly affected. This might partly explain the measured ratio $\tau(\Lambda_{b})/\tau(B^{0})=0.79 $ \cite{Data}, which has been a long-standing discrepancy between theory and experimental data. |
hep-ph/9701323 | Zhukovsky Vladimir | D. Ebert, V.Ch. Zhukovsky | Chiral phase transitions in strong chromomagnetic fields at finite
temperature and dimensional reduction | LATEX file, 12 pages, no figures | Mod.Phys.Lett. A12 (1997) 2567-2576 | 10.1142/S0217732397002697 | HUB-EP-96 | hep-ph | null | Dynamical fermion mass generation in external chromomagnetic fields is
considered at non--zero temperature. The general features of dynamical chiral
symmetry breaking ($D\chi SB$) are investigated for several field
configurations in relation to their symmetry properties and the form of the
quark spectrum. According to the fields, there arises dimensional reduction by
one or two units. In all cases there exists $D\chi SB$ even at weak quark
attraction, confirming the idea about the dimensional insensitivity of this
mechanism in a chromomagnetic field.
| [
{
"created": "Fri, 17 Jan 1997 16:00:48 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Ebert",
"D.",
""
],
[
"Zhukovsky",
"V. Ch.",
""
]
] | Dynamical fermion mass generation in external chromomagnetic fields is considered at non--zero temperature. The general features of dynamical chiral symmetry breaking ($D\chi SB$) are investigated for several field configurations in relation to their symmetry properties and the form of the quark spectrum. According to the fields, there arises dimensional reduction by one or two units. In all cases there exists $D\chi SB$ even at weak quark attraction, confirming the idea about the dimensional insensitivity of this mechanism in a chromomagnetic field. |
1301.4186 | Kwei-Chou Yang | Ho-Chin Tsai, Kwei-Chou Yang | Dark Matter Mass Constrained by the Relic Abundance, Direct Detections,
and Colliders | 25 pages, 9 figures, statements revised, dijet results corrected | null | 10.1103/PhysRevD.87.115016 | CYCU-HEP-13-01 | hep-ph astro-ph.CO astro-ph.GA astro-ph.HE hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We take into account a generic form of a Dirac fermionic dark matter (DM),
which communicates with the Standard Model quarks via a scalar mediator, in a
model-independent way. Four special interaction scenarios are investigated,
where one is parity conserving and the other three are parity violating. Three
of them result in the $v$ suppressed DM-nucleon cross sections, where $v \sim
10^{-3} c$ is the velocity of the DM in the laboratory frame. We constrain the
masses of the dark matter and mediator as well as the couplings from the
thermal relic abundance, and the recent results of the XENON100 direct
detection and collider experiments involving the two channels: (i) monojet plus
large missing transverse energy, and (ii) dijet. The current monojet constraint
is not stronger than that from the requirement of the correct relic density and
the null result by the XENON100 direct detection. We find that the dijet
resonance measurements can exclude a large part of the parameter space
$(m_\chi, m_Y)$, where the couplings for the mediator coupled to the dark
matter and to the quarks are small and have roughly the same magnitude. The
constraint from indirect detections and diphoton resonance searches is also
briefly discussed.
| [
{
"created": "Thu, 17 Jan 2013 18:51:17 GMT",
"version": "v1"
},
{
"created": "Mon, 27 May 2013 18:04:10 GMT",
"version": "v2"
}
] | 2013-06-19 | [
[
"Tsai",
"Ho-Chin",
""
],
[
"Yang",
"Kwei-Chou",
""
]
] | We take into account a generic form of a Dirac fermionic dark matter (DM), which communicates with the Standard Model quarks via a scalar mediator, in a model-independent way. Four special interaction scenarios are investigated, where one is parity conserving and the other three are parity violating. Three of them result in the $v$ suppressed DM-nucleon cross sections, where $v \sim 10^{-3} c$ is the velocity of the DM in the laboratory frame. We constrain the masses of the dark matter and mediator as well as the couplings from the thermal relic abundance, and the recent results of the XENON100 direct detection and collider experiments involving the two channels: (i) monojet plus large missing transverse energy, and (ii) dijet. The current monojet constraint is not stronger than that from the requirement of the correct relic density and the null result by the XENON100 direct detection. We find that the dijet resonance measurements can exclude a large part of the parameter space $(m_\chi, m_Y)$, where the couplings for the mediator coupled to the dark matter and to the quarks are small and have roughly the same magnitude. The constraint from indirect detections and diphoton resonance searches is also briefly discussed. |
1112.0271 | Magno Machado | M. V. T. Machado | Investigating the central diffractive f0(980) and f2(1270) meson
production at the LHC | 7 pages, 4 tables. Final version to be published in Physical Review
D. arXiv admin note: text overlap with arXiv:hep-ph/0508196,
arXiv:hep-ph/0506101 by other authors | null | 10.1103/PhysRevD.86.014029 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The central diffractive production of mesons f0(980) and f2(1270) at the
energy of CERN-LHC experiment on proton-proton collisions is investigated. The
processes initiated by quasi-real photon-photon collisions and by central
diffraction processes are considered. The role played by the photon-Odderon
production channel is also studied. The cross sections for these distinct
production channels are compared and analyzed.
| [
{
"created": "Thu, 1 Dec 2011 19:01:37 GMT",
"version": "v1"
},
{
"created": "Mon, 2 Jul 2012 20:48:03 GMT",
"version": "v2"
}
] | 2013-05-30 | [
[
"Machado",
"M. V. T.",
""
]
] | The central diffractive production of mesons f0(980) and f2(1270) at the energy of CERN-LHC experiment on proton-proton collisions is investigated. The processes initiated by quasi-real photon-photon collisions and by central diffraction processes are considered. The role played by the photon-Odderon production channel is also studied. The cross sections for these distinct production channels are compared and analyzed. |
1909.02013 | Alexander Penin A. | Alexander A. Penin | Regge Limit of Gauge Theory Amplitudes beyond Leading Power
Approximation | 5 pages, 2 figures | null | 10.1007/JHEP04(2020)156 | ALBERTA-THY-08-19 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the high-energy small-angle {\it Regge} limit of the
fermion-antifermion scattering in gauge theories and consider the part of the
amplitude suppressed by a power of the scattering angle. For abelian gauge
group all-order resummation of the double-logarithmic radiative corrections to
the leading power-suppressed term is performed. We find that when the logarithm
of the scattering angle is comparable to the inverse gauge coupling constant
the asymptotic double-logarithmic enhancement overcomes the power suppression,
a formally subleading term becomes dominant, and the small-angle expansion
breaks down. For the nonabelian gauge group we show that in the color-singlet
channel for sufficiently small scattering angles the power-suppressed
contribution becomes comparable to the one of BFKL pomeron. Possible role of
the subleading-power effects for the solution of the unitarity problem of
perturbative Regge analysis in QED and QCD is discussed. An intriguing relation
between the asymptotic behavior of the power-suppressed amplitudes in Regge and
Sudakov limits is discovered.
| [
{
"created": "Wed, 4 Sep 2019 18:00:02 GMT",
"version": "v1"
}
] | 2020-05-20 | [
[
"Penin",
"Alexander A.",
""
]
] | We study the high-energy small-angle {\it Regge} limit of the fermion-antifermion scattering in gauge theories and consider the part of the amplitude suppressed by a power of the scattering angle. For abelian gauge group all-order resummation of the double-logarithmic radiative corrections to the leading power-suppressed term is performed. We find that when the logarithm of the scattering angle is comparable to the inverse gauge coupling constant the asymptotic double-logarithmic enhancement overcomes the power suppression, a formally subleading term becomes dominant, and the small-angle expansion breaks down. For the nonabelian gauge group we show that in the color-singlet channel for sufficiently small scattering angles the power-suppressed contribution becomes comparable to the one of BFKL pomeron. Possible role of the subleading-power effects for the solution of the unitarity problem of perturbative Regge analysis in QED and QCD is discussed. An intriguing relation between the asymptotic behavior of the power-suppressed amplitudes in Regge and Sudakov limits is discovered. |
1806.09364 | De-Liang Yao | De-Liang Yao, Luis Alvarez-Ruso, Astrid N. Hiller Blin, M. J. Vicente
Vacas | Weak pion production off the nucleon in covariant chiral perturbation
theory | 38 pages, 8 figures, 2 tables. Version to appear in PRD, with more
discussions | Phys. Rev. D 98, 076004 (2018) | 10.1103/PhysRevD.98.076004 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Weak pion production off the nucleon at low energies has been systematically
investigated in manifestly relativistic baryon chiral perturbation theory with
explicit inclusion of the $\Delta$(1232) resonance. Most of the involved
low-energy constants have been previously determined in other processes such as
pion-nucleon elastic scattering and electromagnetic pion production off the
nucleon. For numerical estimates, the few remaining constants are set to be of
natural size. As a result, the total cross sections for single pion production
on neutrons and protons, induced either by neutrino or antineutrino, are
predicted. Our results are consistent with the scarce existing experimental
data except in the $\nu_\mu n\to \mu^-n\pi^+$ channel, where higher-order
contributions might still be significant. The $\Delta$ resonance mechanisms
lead to sizeable contributions in all channels, especially in $\nu_\mu p\to
\mu^- p\pi^+$, even though the considered energies are close to the production
threshold. The present study provides a well founded low-energy benchmark for
phenomenological models aimed at the description of weak pion production
processes in the broad kinematic range of interest for current and future
neutrino-oscillation experiments.
| [
{
"created": "Mon, 25 Jun 2018 10:22:36 GMT",
"version": "v1"
},
{
"created": "Thu, 4 Oct 2018 12:37:21 GMT",
"version": "v2"
}
] | 2018-10-10 | [
[
"Yao",
"De-Liang",
""
],
[
"Alvarez-Ruso",
"Luis",
""
],
[
"Blin",
"Astrid N. Hiller",
""
],
[
"Vacas",
"M. J. Vicente",
""
]
] | Weak pion production off the nucleon at low energies has been systematically investigated in manifestly relativistic baryon chiral perturbation theory with explicit inclusion of the $\Delta$(1232) resonance. Most of the involved low-energy constants have been previously determined in other processes such as pion-nucleon elastic scattering and electromagnetic pion production off the nucleon. For numerical estimates, the few remaining constants are set to be of natural size. As a result, the total cross sections for single pion production on neutrons and protons, induced either by neutrino or antineutrino, are predicted. Our results are consistent with the scarce existing experimental data except in the $\nu_\mu n\to \mu^-n\pi^+$ channel, where higher-order contributions might still be significant. The $\Delta$ resonance mechanisms lead to sizeable contributions in all channels, especially in $\nu_\mu p\to \mu^- p\pi^+$, even though the considered energies are close to the production threshold. The present study provides a well founded low-energy benchmark for phenomenological models aimed at the description of weak pion production processes in the broad kinematic range of interest for current and future neutrino-oscillation experiments. |
hep-ph/9807414 | null | M. Suzuki (LBNL and Ucb) | The final-state interaction in the two-body nonleptonic decay of a heavy
particle | 24 pages and one eps figure | null | null | LBNL-42025 | hep-ph | null | We attempt to understand the final-state interaction in the two-body
nonleptonic decay of a heavy particle for which many multibody decay channels
are also open. No matter how many multibody channels couple to the two-body
channels, the analyticity of the S-matrix relates the phase and the magnitude
of the two-body decay amplitude through a dispersion relation. In general,
however, the phase cannot be determined by strong interactions alone. The
dispersion relation requires on a general ground that the final-state
interaction phases be small for the two-body decay amplitudes when the initial
particle is very heavy. We then analyze the final-state interaction phases in
terms of the s-channel eigenstates of the S-matrix and obtain semiquantitative
results applicable to the B decay with a random S-matrix hypothesis. We use the
high-energy scattering date and the dual resonance model as a guide to the
relevant aspects of strong interactions at long and intermediate distances.
| [
{
"created": "Sat, 18 Jul 1998 19:23:27 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Suzuki",
"M.",
"",
"LBNL and Ucb"
]
] | We attempt to understand the final-state interaction in the two-body nonleptonic decay of a heavy particle for which many multibody decay channels are also open. No matter how many multibody channels couple to the two-body channels, the analyticity of the S-matrix relates the phase and the magnitude of the two-body decay amplitude through a dispersion relation. In general, however, the phase cannot be determined by strong interactions alone. The dispersion relation requires on a general ground that the final-state interaction phases be small for the two-body decay amplitudes when the initial particle is very heavy. We then analyze the final-state interaction phases in terms of the s-channel eigenstates of the S-matrix and obtain semiquantitative results applicable to the B decay with a random S-matrix hypothesis. We use the high-energy scattering date and the dual resonance model as a guide to the relevant aspects of strong interactions at long and intermediate distances. |
1603.02531 | Ales Cieply | A. Ciepl\'y, M. Mai, Ulf-G. Mei{\ss}ner, J. Smejkal | On the pole content of coupled channels chiral approaches used for the
$\bar{K}N$ system | 24 pages, 15 figures, to appear in Nuclear Physics A special issue on
Strangeness and Charm Nuclear Physics; v2 - several paragraphs modified or
extended, version accepted for publication | null | null | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Several theoretical groups describe the antikaon-nucleon interaction at low
energies within approaches based on the chiral SU(3) dynamics and including
next-to-leading order contributions. We present a comparative analysis of the
pertinent models and discuss in detail their pole contents. It is demonstrated
that the approaches lead to very different predictions for the $K^{-}p$
amplitude extrapolated to subthreshold energies as well as for the $K^{-}n$
amplitude. The origin of the poles generated by the models is traced to the
so-called zero coupling limit, in which the inter-channel couplings are
switched off. This provides new insights into the pole contents of the various
approaches. In particular, different concepts of forming the $\Lambda(1405)$
resonance are revealed and constraints related to the appearance of such poles
in a given approach are discussed.
| [
{
"created": "Tue, 8 Mar 2016 14:23:35 GMT",
"version": "v1"
},
{
"created": "Fri, 22 Apr 2016 13:32:48 GMT",
"version": "v2"
}
] | 2016-04-25 | [
[
"Cieplý",
"A.",
""
],
[
"Mai",
"M.",
""
],
[
"Meißner",
"Ulf-G.",
""
],
[
"Smejkal",
"J.",
""
]
] | Several theoretical groups describe the antikaon-nucleon interaction at low energies within approaches based on the chiral SU(3) dynamics and including next-to-leading order contributions. We present a comparative analysis of the pertinent models and discuss in detail their pole contents. It is demonstrated that the approaches lead to very different predictions for the $K^{-}p$ amplitude extrapolated to subthreshold energies as well as for the $K^{-}n$ amplitude. The origin of the poles generated by the models is traced to the so-called zero coupling limit, in which the inter-channel couplings are switched off. This provides new insights into the pole contents of the various approaches. In particular, different concepts of forming the $\Lambda(1405)$ resonance are revealed and constraints related to the appearance of such poles in a given approach are discussed. |
hep-ph/9603316 | Geoffrey B. West | Geoffrey B. West (Los Alamos National Laboratory) | Theorem on the Lightest Glueball State | 9 pages, using harvmac | Phys.Rev.Lett. 77 (1996) 2622-2625 | 10.1103/PhysRevLett.77.2622 | LA-UR-96-827 | hep-ph hep-lat hep-th | null | This paper is devoted to proving that, in QCD, the lightest glueball state
must be the scalar with $J^{PC} = 0^{++}$. The proof relies upon the positivity
of the path integral measure in Euclidean space and the fact that interpolating
fields for all spins can be bounded by powers of the scalar glueball operator.
The problem presented by the presence of vacuum condensates is circumvented by
considering the time evolution of the propagators and exploiting the positivity
of the Hamiltonian.
| [
{
"created": "Thu, 14 Mar 1996 23:48:21 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"West",
"Geoffrey B.",
"",
"Los Alamos National Laboratory"
]
] | This paper is devoted to proving that, in QCD, the lightest glueball state must be the scalar with $J^{PC} = 0^{++}$. The proof relies upon the positivity of the path integral measure in Euclidean space and the fact that interpolating fields for all spins can be bounded by powers of the scalar glueball operator. The problem presented by the presence of vacuum condensates is circumvented by considering the time evolution of the propagators and exploiting the positivity of the Hamiltonian. |
hep-ph/9910289 | Yu-Ping Kuang | Qing Wang, Yu-Ping Kuang, Xue-Lei Wang, Ming Xiao | Derivation of the Gasser-Leutwyler Lagrangian from QCD | 4 pages in RevTex | null | null | TU-HEP-TH-99/105 | hep-ph | null | The normal part of the Gasser-Leutwyler formulation of the chiral Lagrangian
is formally derived from the first principles of QCD without taking
approximations. All the coefficients are expressed in terms of certain Green's
functions in QCD, which can be regarded as the general QCD definitions of the
normal part of the coefficients. The approximate values of the coefficients are
also presented.
| [
{
"created": "Sun, 10 Oct 1999 09:09:18 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Wang",
"Qing",
""
],
[
"Kuang",
"Yu-Ping",
""
],
[
"Wang",
"Xue-Lei",
""
],
[
"Xiao",
"Ming",
""
]
] | The normal part of the Gasser-Leutwyler formulation of the chiral Lagrangian is formally derived from the first principles of QCD without taking approximations. All the coefficients are expressed in terms of certain Green's functions in QCD, which can be regarded as the general QCD definitions of the normal part of the coefficients. The approximate values of the coefficients are also presented. |
1106.3482 | Gary Brawn | Richard A. Battye, Gary D. Brawn and Apostolos Pilaftsis | Vacuum Topology of the Two Higgs Doublet Model | 89 pages, 13 tables and 12 figures (version as to appear in JHEP) | JHEP 1108:020,2011 | 10.1007/JHEP08(2011)020 | null | hep-ph astro-ph.CO hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We perform a systematic study of generic accidental Higgs-family and CP
symmetries that could occur in the two-Higgs-doublet-model potential, based on
a Majorana scalar-field formalism which realizes a subgroup of GL(8,C). We
derive the general conditions of convexity and stability of the scalar
potential and present analytical solutions for two non-zero neutral vacuum
expectation values of the Higgs doublets for a typical set of six symmetries,
in terms of the gauge-invariant parameters of the theory. By means of a
homotopy-group analysis, we identify the topological defects associated with
the spontaneous symmetry breaking of each symmetry, as well as the massless
Goldstone bosons emerging from the breaking of the continuous symmetries. We
find the existence of domain walls from the breaking of Z_2, CP1 and CP2
discrete symmetries, vortices in models with broken U(1)_PQ and CP3 symmetries
and a global monopole in the SO(3)_HF-broken model. The spatial profile of the
topological defect solutions is studied in detail, as functions of the
potential parameters of the two-Higgs doublet model. The application of our
Majorana scalar-field formalism in studying more general scalar potentials that
are not constrained by the U(1)_Y hypercharge symmetry is discussed. In
particular, the same formalism may be used to properly identify seven
additional symmetries that may take place in a U(1)_Y-invariant scalar
potential.
| [
{
"created": "Fri, 17 Jun 2011 13:51:11 GMT",
"version": "v1"
},
{
"created": "Tue, 21 Jun 2011 16:56:04 GMT",
"version": "v2"
},
{
"created": "Wed, 17 Aug 2011 11:47:37 GMT",
"version": "v3"
}
] | 2015-05-28 | [
[
"Battye",
"Richard A.",
""
],
[
"Brawn",
"Gary D.",
""
],
[
"Pilaftsis",
"Apostolos",
""
]
] | We perform a systematic study of generic accidental Higgs-family and CP symmetries that could occur in the two-Higgs-doublet-model potential, based on a Majorana scalar-field formalism which realizes a subgroup of GL(8,C). We derive the general conditions of convexity and stability of the scalar potential and present analytical solutions for two non-zero neutral vacuum expectation values of the Higgs doublets for a typical set of six symmetries, in terms of the gauge-invariant parameters of the theory. By means of a homotopy-group analysis, we identify the topological defects associated with the spontaneous symmetry breaking of each symmetry, as well as the massless Goldstone bosons emerging from the breaking of the continuous symmetries. We find the existence of domain walls from the breaking of Z_2, CP1 and CP2 discrete symmetries, vortices in models with broken U(1)_PQ and CP3 symmetries and a global monopole in the SO(3)_HF-broken model. The spatial profile of the topological defect solutions is studied in detail, as functions of the potential parameters of the two-Higgs doublet model. The application of our Majorana scalar-field formalism in studying more general scalar potentials that are not constrained by the U(1)_Y hypercharge symmetry is discussed. In particular, the same formalism may be used to properly identify seven additional symmetries that may take place in a U(1)_Y-invariant scalar potential. |
hep-ph/0507009 | Thomas Hahn | T. Hahn, S. Heinemeyer, W. Hollik, G. Weiglein | Precision Higgs Masses with FeynHiggs 2.2 | 6 pages, to appear in the proceedings of the 2005 International
Linear Collider Workshop (LCWS 2005), Stanford, California, 18-22 Mar 2005 | null | null | MPP-2005-72, CERN-PH-TH/2005-123, IPPP/05/38, DCPT/05/76 | hep-ph | null | FeynHiggs is a program for computing MSSM Higgs-boson masses and related
observables, such as mixing angles, branching ratios, and couplings, including
state-of-the-art higher-order contributions. The centerpiece is a Fortran
library for use with Fortran and C/C++. Alternatively, FeynHiggs has a
command-line, Mathematica, and Web interface. The command-line interface can
process, besides its native format, files in SUSY Les Houches Accord format.
FeynHiggs is an open-source program and easy to install.
| [
{
"created": "Fri, 1 Jul 2005 11:42:08 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Hahn",
"T.",
""
],
[
"Heinemeyer",
"S.",
""
],
[
"Hollik",
"W.",
""
],
[
"Weiglein",
"G.",
""
]
] | FeynHiggs is a program for computing MSSM Higgs-boson masses and related observables, such as mixing angles, branching ratios, and couplings, including state-of-the-art higher-order contributions. The centerpiece is a Fortran library for use with Fortran and C/C++. Alternatively, FeynHiggs has a command-line, Mathematica, and Web interface. The command-line interface can process, besides its native format, files in SUSY Les Houches Accord format. FeynHiggs is an open-source program and easy to install. |
0906.0736 | Carlos E. Yaguna | Ki-Young Choi and Carlos E. Yaguna | Implications of an astrophysical interpretation of PAMELA and Fermi-LAT
data for future searches of a positron signal from dark matter annihilations | 8 pages, 7 figures. To be published in PRD | Phys.Rev.D81:023502,2010 | 10.1103/PhysRevD.81.023502 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The recent data from PAMELA and Fermi-LAT can be interpreted as evidence of
new astrophysical sources of high energy positrons. In that case, such
astrophysical positrons constitute an additional background against the
positrons from dark matter annihilation. In this paper, we study the effect of
that background on the prospects for the detection of a positron dark matter
signal in future experiments. In particular, we determine the new regions in
the (mass, $\sigmav$) plane that are detectable by the AMS-02 experiment for
several dark matter scenarios and different propagation models. We find that,
due to the increased background, these regions feature annihilation rates that
are up to a factor or three larger than those obtained for the conventional
background. That is, an astrophysical interpretation of the present data by
PAMELA and Fermi-LAT implies that the detection of positrons from dark matter
annihilation is slightly more challenging than previously believed.
| [
{
"created": "Wed, 3 Jun 2009 16:02:27 GMT",
"version": "v1"
},
{
"created": "Thu, 17 Dec 2009 19:57:56 GMT",
"version": "v2"
}
] | 2010-01-27 | [
[
"Choi",
"Ki-Young",
""
],
[
"Yaguna",
"Carlos E.",
""
]
] | The recent data from PAMELA and Fermi-LAT can be interpreted as evidence of new astrophysical sources of high energy positrons. In that case, such astrophysical positrons constitute an additional background against the positrons from dark matter annihilation. In this paper, we study the effect of that background on the prospects for the detection of a positron dark matter signal in future experiments. In particular, we determine the new regions in the (mass, $\sigmav$) plane that are detectable by the AMS-02 experiment for several dark matter scenarios and different propagation models. We find that, due to the increased background, these regions feature annihilation rates that are up to a factor or three larger than those obtained for the conventional background. That is, an astrophysical interpretation of the present data by PAMELA and Fermi-LAT implies that the detection of positrons from dark matter annihilation is slightly more challenging than previously believed. |
0709.1745 | Seung-il Nam | Seung-il Nam and Hyun-Chul Kim | Electromagnetic form factors of the pion and kaon from the instanton
vacuum | 11 pages, 5 figures, submitted to PRD | Phys.Rev.D77:094014,2008 | 10.1103/PhysRevD.77.094014 | YITP-07-52,PNU-NTG-10/2007,PNU-NuRI-10/2007 | hep-ph | null | We investigate the pion and kaon (pi^+, K^+, K^0) electromagnetic form
factors in the space-like region: Q^2 ~< 1 GeV, based on the gauged low-energy
effective chiral action from the instanton vacuum in the large N_c limit.
Explicit flavor SU(3) symmetry breaking is taken into account. The nonlocal
contributions turn out to be crucial to reproduce the experimental data. While
the pion electromagnetic form factor is in good agreement with the data, the
kaon one seems underestimated. We also calculate the electromagnetic charge
radii for the pion and kaon: <r^2>_{pi^+}=0.455 fm^2, <r^2>_{K^+}=0.486 fm^2
and <r^2>_{K^0}=-0.055 fm^2 without any adjustable free parameter except for
the average instanton size and inter-instanton distance, and they are
compatible with the experimental data. The low-energy constant L_9 in the large
N_c limit is estimated to be 8.42*10^{-3} from the pion charge radius.
| [
{
"created": "Wed, 12 Sep 2007 02:17:30 GMT",
"version": "v1"
},
{
"created": "Tue, 1 Apr 2008 08:27:37 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Nam",
"Seung-il",
""
],
[
"Kim",
"Hyun-Chul",
""
]
] | We investigate the pion and kaon (pi^+, K^+, K^0) electromagnetic form factors in the space-like region: Q^2 ~< 1 GeV, based on the gauged low-energy effective chiral action from the instanton vacuum in the large N_c limit. Explicit flavor SU(3) symmetry breaking is taken into account. The nonlocal contributions turn out to be crucial to reproduce the experimental data. While the pion electromagnetic form factor is in good agreement with the data, the kaon one seems underestimated. We also calculate the electromagnetic charge radii for the pion and kaon: <r^2>_{pi^+}=0.455 fm^2, <r^2>_{K^+}=0.486 fm^2 and <r^2>_{K^0}=-0.055 fm^2 without any adjustable free parameter except for the average instanton size and inter-instanton distance, and they are compatible with the experimental data. The low-energy constant L_9 in the large N_c limit is estimated to be 8.42*10^{-3} from the pion charge radius. |
1606.08356 | Wolfgang Hollik | Wolfgang Gregor Hollik | A new view on vacuum stability in the MSSM | 32 pages, 10 figures; v3: typos corrected, matches version to be
published in JHEP | JHEP 08 (2016) 126 | 10.1007/JHEP08(2016)126 | DESY 16-114 | hep-ph | http://creativecommons.org/licenses/by/4.0/ | A consistent theoretical description of physics at high energies requires an
assessment of vacuum stability in either the Standard Model or any extension of
it. Especially supersymmetric extensions allow for several vacua and the choice
of the desired electroweak one gives strong constraints on the parameter space.
As the general parameter space in the Minimal Supersymmetric Standard Model is
huge, any severe constraint on it unrelated to direct phenomenological
observations enhances the predictability of the model. We perform an updated
analysis of possible charge and color breaking minima without relying on fixed
directions in field space that minimize certain terms in the potential (known
as "D-flat" directions). Concerning the cosmological stability of false vacua,
we argue that there are always directions in configuration space which lead to
very short-lived vacua and therefore such exclusions are strict. In addition to
existing strong constraints on the parameter space, we find even stronger
constraints extending the field space compared to previous analyses and combine
those constraints with predictions for the light CP-even Higgs mass in the
Minimal Supersymmetric Standard Model. Low masses for supersymmetric partners
are excluded from vacuum stability in combination with the 125 GeV Higgs and
the allowed parameter space opens at a few TeV.
| [
{
"created": "Mon, 27 Jun 2016 16:34:35 GMT",
"version": "v1"
},
{
"created": "Mon, 4 Jul 2016 17:24:36 GMT",
"version": "v2"
},
{
"created": "Fri, 19 Aug 2016 18:01:55 GMT",
"version": "v3"
}
] | 2016-08-26 | [
[
"Hollik",
"Wolfgang Gregor",
""
]
] | A consistent theoretical description of physics at high energies requires an assessment of vacuum stability in either the Standard Model or any extension of it. Especially supersymmetric extensions allow for several vacua and the choice of the desired electroweak one gives strong constraints on the parameter space. As the general parameter space in the Minimal Supersymmetric Standard Model is huge, any severe constraint on it unrelated to direct phenomenological observations enhances the predictability of the model. We perform an updated analysis of possible charge and color breaking minima without relying on fixed directions in field space that minimize certain terms in the potential (known as "D-flat" directions). Concerning the cosmological stability of false vacua, we argue that there are always directions in configuration space which lead to very short-lived vacua and therefore such exclusions are strict. In addition to existing strong constraints on the parameter space, we find even stronger constraints extending the field space compared to previous analyses and combine those constraints with predictions for the light CP-even Higgs mass in the Minimal Supersymmetric Standard Model. Low masses for supersymmetric partners are excluded from vacuum stability in combination with the 125 GeV Higgs and the allowed parameter space opens at a few TeV. |
hep-ph/0609225 | Zuo-Tang Liang | Zuo-tang Liang and Xin-Nian Wang | Azimuthal and single spin asymmetry in deep-inelastic lepton-nucleon
scattering | 9 pages, 1 figure | Phys.Rev.D75:094002,2007 | 10.1103/PhysRevD.75.094002 | LBNL-61449 | hep-ph | null | We derive a general framework for describing semi-inclusive deep-inelastic
lepton-nucleon scattering in terms of the unintegrated parton distributions and
other higher twist parton correlations. Such a framework provides a consistent
approach to the calculation of inclusive and semi-inclusive cross sections
including higher twist effects. As an example, we calculate the azimuthal
asymmetries to the order of 1/Q in semi-inclusive process with transversely
polarized target. A non-vanishing single-spin asymmetry in the ``triggered
inclusive process'' is predicted to be 1/Q suppressed with a part of the
coefficient related to a moment of the Sivers function.
| [
{
"created": "Thu, 21 Sep 2006 18:40:59 GMT",
"version": "v1"
},
{
"created": "Thu, 3 May 2007 10:39:32 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Liang",
"Zuo-tang",
""
],
[
"Wang",
"Xin-Nian",
""
]
] | We derive a general framework for describing semi-inclusive deep-inelastic lepton-nucleon scattering in terms of the unintegrated parton distributions and other higher twist parton correlations. Such a framework provides a consistent approach to the calculation of inclusive and semi-inclusive cross sections including higher twist effects. As an example, we calculate the azimuthal asymmetries to the order of 1/Q in semi-inclusive process with transversely polarized target. A non-vanishing single-spin asymmetry in the ``triggered inclusive process'' is predicted to be 1/Q suppressed with a part of the coefficient related to a moment of the Sivers function. |
hep-ph/0606094 | Cai-Dian Lu | Cai-Dian Lu (IHEP, Beijing) | Polarization Study in B Decays to Vector Final States | 4 pages; Talk presented at the 41th Rencontres de Moriond on QCD and
High Energy Hadronic Interactions, La Thuile, Italy, March 18-25, 2006 | null | null | null | hep-ph | null | The small longitudinal polarization fractions (50%) of $B \to \phi K^*$
measured by B factories contradict with the naive theoretical counting rules.
We review the current theoretical status of the $B\to VV$ decay studies and
calculate many of them in the perturbative QCD factorization approach based on
$k_T$ factorization. We find that the penguin annihilation and non-factorizable
emission diagrams can enhance the transverse polarization fractions. The PQCD
results agree with experiments for the measured $B\to \phi K^*$, $B\to \rho
K^*$ and $B\to \rho \rho$ channels, and we also predict new results (some
different from other approaches) for those not yet measured channels.
| [
{
"created": "Thu, 8 Jun 2006 07:29:51 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Lu",
"Cai-Dian",
"",
"IHEP, Beijing"
]
] | The small longitudinal polarization fractions (50%) of $B \to \phi K^*$ measured by B factories contradict with the naive theoretical counting rules. We review the current theoretical status of the $B\to VV$ decay studies and calculate many of them in the perturbative QCD factorization approach based on $k_T$ factorization. We find that the penguin annihilation and non-factorizable emission diagrams can enhance the transverse polarization fractions. The PQCD results agree with experiments for the measured $B\to \phi K^*$, $B\to \rho K^*$ and $B\to \rho \rho$ channels, and we also predict new results (some different from other approaches) for those not yet measured channels. |
hep-ph/0612323 | M.I. Vyazovsky | M.A.Braun and M.I.Vyazovsky | The Reggeon $\to$ 2 Reggeons $+$ Particle vertex in the Lipatov
effective action formalism | 4 figures; misprints corrected; to be published in Eur.Phys.J. C | Eur.Phys.J.C51:103-111,2007 | 10.1140/epjc/s10052-007-0270-2 | null | hep-ph | null | The vertex for gluon emission during the splitting of a reggeized gluon into
two is constructed in the framework of Lipatov effective action formalism. Its
reduction to a pure transverse form for the diffractive amplitude gives the
standard Bartels vertex plus an additional contribution corresponding to the
emission from a pointlike splitting vertex. This additional contribution turns
out to be given by a longitudinal integral divergent both in the ultraviolet
and infrared. A certain specific recipe for this part, including the principal
value prescription for the integration, allows to eliminate this unwanted
contribution.
| [
{
"created": "Sat, 23 Dec 2006 20:07:39 GMT",
"version": "v1"
},
{
"created": "Sun, 25 Feb 2007 05:34:03 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Braun",
"M. A.",
""
],
[
"Vyazovsky",
"M. I.",
""
]
] | The vertex for gluon emission during the splitting of a reggeized gluon into two is constructed in the framework of Lipatov effective action formalism. Its reduction to a pure transverse form for the diffractive amplitude gives the standard Bartels vertex plus an additional contribution corresponding to the emission from a pointlike splitting vertex. This additional contribution turns out to be given by a longitudinal integral divergent both in the ultraviolet and infrared. A certain specific recipe for this part, including the principal value prescription for the integration, allows to eliminate this unwanted contribution. |
0711.1311 | Itzhak Baum | Itzhak Baum | Top quark rare decays in a two Higgs doublet model for the top | M.Sc. thesis, 45 pages | null | null | null | hep-ph | null | The two Higgs doublet model for the top (T2HDM) is a 2HDM in which the top
quark receives a special status, which endows it with a naturally large mass,
and also gives rise to unique FC charged and neutral scalar interactions. We
calculate the BR of the t->ch and h->tc rare decays in the T2HDM, at 1-loop and
tree level. We find that the FC scalar interactions play a significant role in
these decays. We find that the BR of these decays at 1-loop level in the T2HDM
can be significantly enhanced over the 2HDM-I,II, reaching up to ~10^-4, and
that the BR(t->ch) in the T2HDM can be detected at the LHC.
| [
{
"created": "Thu, 8 Nov 2007 16:35:33 GMT",
"version": "v1"
}
] | 2007-11-09 | [
[
"Baum",
"Itzhak",
""
]
] | The two Higgs doublet model for the top (T2HDM) is a 2HDM in which the top quark receives a special status, which endows it with a naturally large mass, and also gives rise to unique FC charged and neutral scalar interactions. We calculate the BR of the t->ch and h->tc rare decays in the T2HDM, at 1-loop and tree level. We find that the FC scalar interactions play a significant role in these decays. We find that the BR of these decays at 1-loop level in the T2HDM can be significantly enhanced over the 2HDM-I,II, reaching up to ~10^-4, and that the BR(t->ch) in the T2HDM can be detected at the LHC. |
hep-ph/0401199 | Per Osland | E.W. Dvergsnes, P. Osland (Bergen), A.A. Pankov (Gomel, Trieste) and
N. Paver (Trieste) | Center-Edge Asymmetry at Hadron Colliders | 23 pages, including figures | Phys.Rev. D69 (2004) 115001 | 10.1103/PhysRevD.69.115001 | null | hep-ph | null | We investigate the possibility of using the center-edge asymmetry to
distinguish graviton exchange from other new physics effects at hadron
colliders. Specifically, we study lepton-pair production within the ADD and RS
scenarios. At the Tevatron, the graviton-Z interference is the most important
contribution to the center-edge asymmetry, whereas at the LHC, the dominant
contribution comes from gluon fusion via graviton exchange, which has no
analogue at e^+ e^- colliders. We find that spin-2 and spin-1 exchange can be
distinguished up to an ADD cut-off scale, M_H, of about 5 TeV, at the 95% CL.
In the RS scenario, spin-2 resonances can be identified in most of the favored
parameter space.
| [
{
"created": "Mon, 26 Jan 2004 09:00:25 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Dvergsnes",
"E. W.",
"",
"Bergen"
],
[
"Osland",
"P.",
"",
"Bergen"
],
[
"Pankov",
"A. A.",
"",
"Gomel, Trieste"
],
[
"Paver",
"N.",
"",
"Trieste"
]
] | We investigate the possibility of using the center-edge asymmetry to distinguish graviton exchange from other new physics effects at hadron colliders. Specifically, we study lepton-pair production within the ADD and RS scenarios. At the Tevatron, the graviton-Z interference is the most important contribution to the center-edge asymmetry, whereas at the LHC, the dominant contribution comes from gluon fusion via graviton exchange, which has no analogue at e^+ e^- colliders. We find that spin-2 and spin-1 exchange can be distinguished up to an ADD cut-off scale, M_H, of about 5 TeV, at the 95% CL. In the RS scenario, spin-2 resonances can be identified in most of the favored parameter space. |
0707.2643 | Stanley J. Brodsky | Stanley J. Brodsky | Novel QCD Phenomena | Invited talk presented at the Workshop on High PT Physics at the LHC
(LHC07), Jyvaskyla, Finland, 23-27 March 2007; typos corrected; added
reference;resolution of figures improved | PoS LHC07:002,2007 | null | SLAC-PUB-12632 | hep-ph | null | I discuss a number of novel topics in QCD, including the use of the AdS/CFT
correspondence between Anti-de Sitter space and conformal gauge theories to
obtain an analytically tractable approximation to QCD in the regime where the
QCD coupling is large and constant. In particular, there is an exact
correspondence between the fifth-dimension coordinate z of AdS space and a
specific impact variable zeta which measures the separation of the quark
constituents within the hadron in ordinary space-time. This connection allows
one to compute the analytic form of the frame-independent light-front
wavefunctions of mesons and baryons, the fundamental entities which encode
hadron properties and allow the computation of exclusive scattering amplitudes.
I also discuss a number of novel phenomenological features of QCD. Initial- and
final-state interactions from gluon-exchange, normally neglected in the parton
model, have a profound effect in QCD hard-scattering reactions, leading to
leading-twist single-spin asymmetries, diffractive deep inelastic scattering,
diffractive hard hadronic reactions, the breakdown of the Lam Tung relation in
Drell-Yan reactions, and nuclear shadowing and non-universal
antishadowing--leading-twist physics not incorporated in the light-front
wavefunctions of the target computed in isolation. I also discuss tests of
hidden color in nuclear wavefunctions, the use of diffraction to materialize
the Fock states of a hadronic projectile and test QCD color transparency, and
anomalous heavy quark effects. The presence of direct higher-twist processes
where a proton is produced in the hard subprocess can explain the large
proton-to-pion ratio seen in high-centrality heavy-ion collisions.
| [
{
"created": "Wed, 18 Jul 2007 06:21:18 GMT",
"version": "v1"
},
{
"created": "Sat, 21 Jul 2007 07:50:29 GMT",
"version": "v2"
},
{
"created": "Tue, 24 Jul 2007 07:40:57 GMT",
"version": "v3"
}
] | 2009-09-11 | [
[
"Brodsky",
"Stanley J.",
""
]
] | I discuss a number of novel topics in QCD, including the use of the AdS/CFT correspondence between Anti-de Sitter space and conformal gauge theories to obtain an analytically tractable approximation to QCD in the regime where the QCD coupling is large and constant. In particular, there is an exact correspondence between the fifth-dimension coordinate z of AdS space and a specific impact variable zeta which measures the separation of the quark constituents within the hadron in ordinary space-time. This connection allows one to compute the analytic form of the frame-independent light-front wavefunctions of mesons and baryons, the fundamental entities which encode hadron properties and allow the computation of exclusive scattering amplitudes. I also discuss a number of novel phenomenological features of QCD. Initial- and final-state interactions from gluon-exchange, normally neglected in the parton model, have a profound effect in QCD hard-scattering reactions, leading to leading-twist single-spin asymmetries, diffractive deep inelastic scattering, diffractive hard hadronic reactions, the breakdown of the Lam Tung relation in Drell-Yan reactions, and nuclear shadowing and non-universal antishadowing--leading-twist physics not incorporated in the light-front wavefunctions of the target computed in isolation. I also discuss tests of hidden color in nuclear wavefunctions, the use of diffraction to materialize the Fock states of a hadronic projectile and test QCD color transparency, and anomalous heavy quark effects. The presence of direct higher-twist processes where a proton is produced in the hard subprocess can explain the large proton-to-pion ratio seen in high-centrality heavy-ion collisions. |
1210.3150 | Lance Labun | Lance Labun and Johann Rafelski | Higgs two-gluon decay and the top-quark chromomagnetic moment | 4 pages, 3 figures, elsarticle format, v2 added section "Gluon Fusion
into Higgs" | null | null | CERN-PH-TH/2012-265 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the top quark chromomagnetic factor $\kappa_t$-dependence of the
effective interaction ${\cal L}_{hgg}$ and apply the result to the case of
Higgs two gluon decay rate $\Gamma_{h\to gg}$. Perturbative standard model
provides $\kappa_t< 2$, and for the standard model value $\Gamma_{h\to
gg}(\kappa_t)$ is suppressed by 9% as compared to $\kappa_t= 2$. We further
show that in the leading order $\Gamma_{h\to gg}$ for $\kappa_t\simeq \pm 1.2$
can be very small due to complete cancelation between the top and bottom quark
fluctuations. We discuss the extension of our results to $\kappa_t>2$ and
consider potential paths to obtain experimental information for the $h\to gg$
rate.
| [
{
"created": "Thu, 11 Oct 2012 08:23:10 GMT",
"version": "v1"
},
{
"created": "Fri, 12 Apr 2013 07:52:35 GMT",
"version": "v2"
}
] | 2013-04-15 | [
[
"Labun",
"Lance",
""
],
[
"Rafelski",
"Johann",
""
]
] | We study the top quark chromomagnetic factor $\kappa_t$-dependence of the effective interaction ${\cal L}_{hgg}$ and apply the result to the case of Higgs two gluon decay rate $\Gamma_{h\to gg}$. Perturbative standard model provides $\kappa_t< 2$, and for the standard model value $\Gamma_{h\to gg}(\kappa_t)$ is suppressed by 9% as compared to $\kappa_t= 2$. We further show that in the leading order $\Gamma_{h\to gg}$ for $\kappa_t\simeq \pm 1.2$ can be very small due to complete cancelation between the top and bottom quark fluctuations. We discuss the extension of our results to $\kappa_t>2$ and consider potential paths to obtain experimental information for the $h\to gg$ rate. |
hep-ph/9412325 | Takeshi Nihei | Takeshi Nihei and Jiro Arafune | The Two Loop Long Range Effect on the Proton Decay Effective Lagrangian | 11 pages, 1 figures(uuencoded postscript file) | Prog.Theor.Phys. 93 (1995) 665-669 | 10.1143/ptp/93.3.665 | ICRR-Report-334-94-29 | hep-ph | null | We calculate the two loop long range effect on the proton decay effective
Lagrangian. Numerical calculation for suppression factor gives $ A_L($2-loop$)
= 0.321$ for the value of the strong coupling constant $ \alpha_s(m_Z) = 0.116
$. Two loop effect to more general effective Lagrangian is also given.
| [
{
"created": "Tue, 20 Dec 1994 02:57:38 GMT",
"version": "v1"
}
] | 2017-02-01 | [
[
"Nihei",
"Takeshi",
""
],
[
"Arafune",
"Jiro",
""
]
] | We calculate the two loop long range effect on the proton decay effective Lagrangian. Numerical calculation for suppression factor gives $ A_L($2-loop$) = 0.321$ for the value of the strong coupling constant $ \alpha_s(m_Z) = 0.116 $. Two loop effect to more general effective Lagrangian is also given. |
2106.02962 | Tania Robens | Tania Robens | The THDMa revisited | 30 pages, 8 figures; v2: 33 pages, 8 figures, corresponds to
published journal version (slight style differences) | null | 10.3390/sym13122341 | RBI-ThPhys-2021-25 | hep-ph | http://creativecommons.org/licenses/by/4.0/ | The THDMa is a new physics model that extends the scalar sector of the
Standard Model by an additional doublet as well as a pseudoscalar singlet and
allows for mixing between all possible scalar states. In the gauge-eigenbasis,
the additional pseudoscalar serves as a portal to the dark sector, with a
priori any dark matter spins states. The option where dark matter is fermionic
is currently one of the standard benchmarks for the experimental
collaborations, and several searches at the LHC constrain the corresponding
parameter space. However, most current studies constrain regions in parameter
space by setting all but 2 of the 12 free parameters to fixed values. In this
work, we perform a generic scan on this model, allowing all parameters to
float. We apply all current theoretical and experimental constraints, including
bounds from current searches, recent results from B-physics, in particular B_s
-> X_s gamma, as well as bounds from astroparticle physics. We identify regions
in the parameter space which are still allowed after these have been applied
and which might be interesting for an investigation at current and future
collider machines.
| [
{
"created": "Sat, 5 Jun 2021 20:56:36 GMT",
"version": "v1"
},
{
"created": "Tue, 14 Dec 2021 18:38:16 GMT",
"version": "v2"
}
] | 2021-12-15 | [
[
"Robens",
"Tania",
""
]
] | The THDMa is a new physics model that extends the scalar sector of the Standard Model by an additional doublet as well as a pseudoscalar singlet and allows for mixing between all possible scalar states. In the gauge-eigenbasis, the additional pseudoscalar serves as a portal to the dark sector, with a priori any dark matter spins states. The option where dark matter is fermionic is currently one of the standard benchmarks for the experimental collaborations, and several searches at the LHC constrain the corresponding parameter space. However, most current studies constrain regions in parameter space by setting all but 2 of the 12 free parameters to fixed values. In this work, we perform a generic scan on this model, allowing all parameters to float. We apply all current theoretical and experimental constraints, including bounds from current searches, recent results from B-physics, in particular B_s -> X_s gamma, as well as bounds from astroparticle physics. We identify regions in the parameter space which are still allowed after these have been applied and which might be interesting for an investigation at current and future collider machines. |
hep-ph/9612346 | Marta Losada | Glennys R. Farrar and Marta Losada | SUSY and the Electroweak Phase Transition | 17 pages, 6 figures, uses epsf | Phys.Lett. B406 (1997) 60-65 | 10.1016/S0370-2693(97)00663-1 | RU-96-26 | hep-ph | null | We analyze the effective 3 dimensional theory previously constructed for the
MSSM and multi-Higgs models to determine the regions of parameter space in
which the electroweak phase transition is sufficiently strong for a $B+L$
asymmetry to survive in the low temperature phase. We find that the inclusion
of all supersymmetric scalars and all 1-loop corrections has the effect of
enhancing the strength of the phase transition. Without a light stop or
extension of the MSSM the phase transition is sufficiently first order only if
the lightest Higgs mass $M_{h}\lsi 70$ GeV and $tan\beta\lsi 1.75$.
| [
{
"created": "Thu, 12 Dec 1996 22:43:19 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Farrar",
"Glennys R.",
""
],
[
"Losada",
"Marta",
""
]
] | We analyze the effective 3 dimensional theory previously constructed for the MSSM and multi-Higgs models to determine the regions of parameter space in which the electroweak phase transition is sufficiently strong for a $B+L$ asymmetry to survive in the low temperature phase. We find that the inclusion of all supersymmetric scalars and all 1-loop corrections has the effect of enhancing the strength of the phase transition. Without a light stop or extension of the MSSM the phase transition is sufficiently first order only if the lightest Higgs mass $M_{h}\lsi 70$ GeV and $tan\beta\lsi 1.75$. |
hep-ph/9807384 | Judith McGovern | Judith A. McGovern, Michael C. Birse | On the absence of fifth-order contributions to the nucleon mass in
heavy-baryon chiral perturbation theory | 4 pages RevTex, 4 eps figures | Phys.Lett. B446 (1999) 300-305 | 10.1016/S0370-2693(98)01550-0 | MC/TH 98/13 | hep-ph nucl-th | null | (New version with some expanded discussion; figures and minor typos
corrected.)
We have calculated the contribution proportional to the fifth power of the
pion mass in the chiral expansion of the nucleon mass in two flavour HBCPT.
Only one irreducible two-loop integral enters, and this vanishes. All other
corrections in the heavy-baryon limit can be absorbed in the physical
pion-nucleon coupling constant which enters in the third order term, and so
there are no contributions at fifth order. Including finite nucleon mass
corrections, the only contribution agrees with the expansion of the
relativistic one-loop graph in powers of the ration of the pion and nucleon
masses, and is only 0.3% of the third order term. This is an encouraging result
for the convergence of two-flavour heavy-baryon chiral perturbation theory.
| [
{
"created": "Wed, 15 Jul 1998 16:18:09 GMT",
"version": "v1"
},
{
"created": "Tue, 22 Dec 1998 12:04:59 GMT",
"version": "v2"
}
] | 2009-10-31 | [
[
"McGovern",
"Judith A.",
""
],
[
"Birse",
"Michael C.",
""
]
] | (New version with some expanded discussion; figures and minor typos corrected.) We have calculated the contribution proportional to the fifth power of the pion mass in the chiral expansion of the nucleon mass in two flavour HBCPT. Only one irreducible two-loop integral enters, and this vanishes. All other corrections in the heavy-baryon limit can be absorbed in the physical pion-nucleon coupling constant which enters in the third order term, and so there are no contributions at fifth order. Including finite nucleon mass corrections, the only contribution agrees with the expansion of the relativistic one-loop graph in powers of the ration of the pion and nucleon masses, and is only 0.3% of the third order term. This is an encouraging result for the convergence of two-flavour heavy-baryon chiral perturbation theory. |
hep-ph/0310318 | Peter Schweitzer | P.Schweitzer, A.Bacchetta | Azimuthal single spin asymmetries in SIDIS in the light of chiral
symmetry breaking | 14 pages, 18 figures | Nucl.Phys. A732 (2004) 106-124 | 10.1016/j.nuclphysa.2003.12.010 | null | hep-ph | null | An attempt is made to understand the z-dependence of the azimuthal single
spin asymmetries observed by the HERMES collaboration in terms of chiral models
based on effective quark and Goldstone boson degrees of freedom. The effects of
respectively neglecting and considering Gaussian intrinsic parton transverse
momenta and the Sivers effect are explored. Predictions for the transverse
target polarization experiment at HERMES are presented.
| [
{
"created": "Tue, 28 Oct 2003 19:15:29 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Schweitzer",
"P.",
""
],
[
"Bacchetta",
"A.",
""
]
] | An attempt is made to understand the z-dependence of the azimuthal single spin asymmetries observed by the HERMES collaboration in terms of chiral models based on effective quark and Goldstone boson degrees of freedom. The effects of respectively neglecting and considering Gaussian intrinsic parton transverse momenta and the Sivers effect are explored. Predictions for the transverse target polarization experiment at HERMES are presented. |
hep-ph/9603273 | Mccsnrw | Niels R. Walet (UMIST) | Quantising the B=2 and B=3 Skyrmion systems | 32 pages, 19 Postscript figures, uses epsfig.sty and elsart.sty | Nucl.Phys. A606 (1996) 429-458 | 10.1016/0375-9474(96)00219-9 | UMIST/TP/96-1 | hep-ph | null | We examine the quantisation of a collective Hamiltonian for the two-baryon
system derived by us in a previous paper. We show that by increasing the
sophistication of the approximations we can obtain a bound state - or a
resonance - not too far removed from the threshold with the quantum numbers of
the deuteron. The energy of this state is shown to depend very sensitively on
the parameters of the model. Subsequently we construct part of a collective
Hamiltonian for the three baryon system. Large-amplitude quantum fluctuations
play an important r\^ole in the intrinsic wave function of the ground-state,
changing its symmetry from octahedral to cubic. Apart from the tetrahedron
describing the minimum of the potential, we identify a ``doughnut'' and a
``pretzel'' as the most important saddle points in the potential energy
surface. We show that it is likely that inclusion of fluctuations through these
saddle points lead to an energy close to the triton's value.
| [
{
"created": "Mon, 11 Mar 1996 16:08:11 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Walet",
"Niels R.",
"",
"UMIST"
]
] | We examine the quantisation of a collective Hamiltonian for the two-baryon system derived by us in a previous paper. We show that by increasing the sophistication of the approximations we can obtain a bound state - or a resonance - not too far removed from the threshold with the quantum numbers of the deuteron. The energy of this state is shown to depend very sensitively on the parameters of the model. Subsequently we construct part of a collective Hamiltonian for the three baryon system. Large-amplitude quantum fluctuations play an important r\^ole in the intrinsic wave function of the ground-state, changing its symmetry from octahedral to cubic. Apart from the tetrahedron describing the minimum of the potential, we identify a ``doughnut'' and a ``pretzel'' as the most important saddle points in the potential energy surface. We show that it is likely that inclusion of fluctuations through these saddle points lead to an energy close to the triton's value. |
hep-ph/9512256 | V. L. Yudichev | A.A.Andrianov, V.A.Andrianov, V.L.Yudichev ( Institute of Physics,
Sankt-Petersburg, Russia ) | Dynamical P-parity Breaking in Effective Quark Model | 7 pages of text in TeX. (To appear in Proceedings of X International
Workshop on HEP and QFT, Zvenigorod, Russia, ed. B.B.Levtchenko: MSU publ.
1995.) | null | null | null | hep-ph | null | Fermion models with selfinteraction including derivatives of fields are
investigated in the strong coupling regime. The existence of three phases is
established in the two channel model near tricritical point. The special phase
of dynamical P-parity breaking is found.
| [
{
"created": "Thu, 7 Dec 1995 17:06:27 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Andrianov",
"A. A.",
"",
"Institute of Physics,\n Sankt-Petersburg, Russia"
],
[
"Andrianov",
"V. A.",
"",
"Institute of Physics,\n Sankt-Petersburg, Russia"
],
[
"Yudichev",
"V. L.",
"",
"Institute of Physics,\n Sankt-Petersburg, Russia"
]
] | Fermion models with selfinteraction including derivatives of fields are investigated in the strong coupling regime. The existence of three phases is established in the two channel model near tricritical point. The special phase of dynamical P-parity breaking is found. |
hep-ph/9410392 | Georg Botz | G. W. Botz, P. Haberl, and O. Nachtmann | Soft Photons in Hadron-Hadron Collisions: Synchrotron Radiation from the
QCD Vacuum? | Heidelberg preprint HD-THEP-94-36, 31 pages, LaTeX + ZJCITE.sty
(included), 12 figures appended as uuencoded compressed ps-file | Z.Phys. C67 (1995) 143-158 | 10.1007/BF01564830 | null | hep-ph nucl-th | null | We discuss the production of soft photons in high energy hadron-hadron
collisions. We present a model where quarks and antiquarks in the hadrons emit
``synchrotron light'' when being deflected by the chromomagnetic fields of the
QCD vacuum, which we assume to have a nonperturbative structure. This gives a
source of prompt soft photons with frequencies $\omega <= 300 MeV$ in the c.m.
system of the collision in addition to hadronic bremsstrahlung. In comparing
the frequency spectrum and rate of ``synchrotron'' photons to experimental
results we find some supporting evidence for their existence. We make an
exclusive--inclusive connection argument to deduce from the ``synchrotron''
effect a behaviour of the neutron electric formfactor $G_E^n(Q^2)$ proportional
to $(Q^2)^{1/6}$ for $Q^2 < 20 fm^{-2}$. We find this to be consistent with
available data. In our view, soft photon production in high energy
hadron-hadron and lepton-hadron collisions as well as the behaviour of
electromagnetic hadron formfactors for low $Q^2$ are thus sensitive probes of
the nonperturbative structure of the QCD vacuum.
| [
{
"created": "Thu, 27 Oct 1994 13:47:31 GMT",
"version": "v1"
},
{
"created": "Fri, 28 Oct 1994 18:21:02 GMT",
"version": "v2"
}
] | 2009-10-28 | [
[
"Botz",
"G. W.",
""
],
[
"Haberl",
"P.",
""
],
[
"Nachtmann",
"O.",
""
]
] | We discuss the production of soft photons in high energy hadron-hadron collisions. We present a model where quarks and antiquarks in the hadrons emit ``synchrotron light'' when being deflected by the chromomagnetic fields of the QCD vacuum, which we assume to have a nonperturbative structure. This gives a source of prompt soft photons with frequencies $\omega <= 300 MeV$ in the c.m. system of the collision in addition to hadronic bremsstrahlung. In comparing the frequency spectrum and rate of ``synchrotron'' photons to experimental results we find some supporting evidence for their existence. We make an exclusive--inclusive connection argument to deduce from the ``synchrotron'' effect a behaviour of the neutron electric formfactor $G_E^n(Q^2)$ proportional to $(Q^2)^{1/6}$ for $Q^2 < 20 fm^{-2}$. We find this to be consistent with available data. In our view, soft photon production in high energy hadron-hadron and lepton-hadron collisions as well as the behaviour of electromagnetic hadron formfactors for low $Q^2$ are thus sensitive probes of the nonperturbative structure of the QCD vacuum. |
hep-ph/9707411 | null | Frank X. Lee (U. of Colorado) | Magnetic Moments of $\Delta^{++}$ and $\Omega^-$ from QCD Sum Rules | 10 pages, RevTex, 1 PS figure embedded with psfig.sty | Phys.Lett. B419 (1998) 14-18 | 10.1016/S0370-2693(97)01312-9 | CU-NPL-1149 | hep-ph nucl-th | null | QCD sum rules for the magnetic moments of $\Delta^{++}$ and $\Omega^-$ are
derived using the external field method. They are analyzed by a Monte-Carlo
based procedure, using realistic estimates of the QCD input parameters. The
results are consistent with the measured values, despite relatively large
errors that can be attributed mostly to the poorly-known vacuum susceptibility
$\chi$. It is shown that a 30% level accuracy can be achieved in the derived
sum rules, provided the QCD input parameters are improved to the 10% level.
| [
{
"created": "Mon, 21 Jul 1997 21:09:38 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Lee",
"Frank X.",
"",
"U. of Colorado"
]
] | QCD sum rules for the magnetic moments of $\Delta^{++}$ and $\Omega^-$ are derived using the external field method. They are analyzed by a Monte-Carlo based procedure, using realistic estimates of the QCD input parameters. The results are consistent with the measured values, despite relatively large errors that can be attributed mostly to the poorly-known vacuum susceptibility $\chi$. It is shown that a 30% level accuracy can be achieved in the derived sum rules, provided the QCD input parameters are improved to the 10% level. |
hep-ph/9806538 | Adam Falk | Adam F. Falk | Final State Interactions in Hadronic B Decays | 10 pages, uses sprocl.sty. To appear in the proceedings of Continuous
Advances in QCD 1998, Theoretical Physics Institute, University of Minnesota,
April 16-19, 1998 | null | null | JHU-TIPAC-98008 | hep-ph | null | I discuss the effect of final state interactions on the determination of the
CKM angle \gamma from B -> K + pi decays. Using a simple Regge-based model for
rescattering processes, I argue that such effects could be substantial enough
to make it problematic to obtain reliable limits on \gamma in this way.
Fortunately, an analysis of B -> K + K decays may provide model-independent
bounds on rescattering contributions.
| [
{
"created": "Tue, 30 Jun 1998 20:23:22 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Falk",
"Adam F.",
""
]
] | I discuss the effect of final state interactions on the determination of the CKM angle \gamma from B -> K + pi decays. Using a simple Regge-based model for rescattering processes, I argue that such effects could be substantial enough to make it problematic to obtain reliable limits on \gamma in this way. Fortunately, an analysis of B -> K + K decays may provide model-independent bounds on rescattering contributions. |
1410.6193 | Warren Wright | Irina Mocioiu and Warren Wright | Non-Standard Neutrino Interactions in the mu-tau sector | 17 pages, 11 figures | null | 10.1016/j.nuclphysb.2015.02.016 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss the effects of non-standard neutrino interactions on muon rates in
high statistics atmospheric neutrino oscillation experiments like IceCube
DeepCore. We concentrate on the mu-tau sector, which is presently the least
constrained. It is shown that the magnitude of the effects depends strongly on
the sign of the Epsilon_MuTau parameter describing this non-standard
interactions. A simple analytic model is used to understand the parameter space
where differences between the two signs are maximized. We discuss how this
effect is partially degenerate with changing the neutrino mass hierarchy, as
well as how this degeneracy could be lifted.
| [
{
"created": "Wed, 22 Oct 2014 21:07:41 GMT",
"version": "v1"
}
] | 2015-05-20 | [
[
"Mocioiu",
"Irina",
""
],
[
"Wright",
"Warren",
""
]
] | We discuss the effects of non-standard neutrino interactions on muon rates in high statistics atmospheric neutrino oscillation experiments like IceCube DeepCore. We concentrate on the mu-tau sector, which is presently the least constrained. It is shown that the magnitude of the effects depends strongly on the sign of the Epsilon_MuTau parameter describing this non-standard interactions. A simple analytic model is used to understand the parameter space where differences between the two signs are maximized. We discuss how this effect is partially degenerate with changing the neutrino mass hierarchy, as well as how this degeneracy could be lifted. |
1110.1174 | Chun Hay Kom | Jonathan R. Gaunt, C. H. Kom, A. Kulesza, W. J. Stirling | Probing double parton scattering with leptonic final states at the LHC | 8 pages, 3 figures. Contribution to the proceedings of the MPI@LHC
2010 workshop in Glasgow UK | null | null | Cavendish-HEP-2011-19, DAMTP-2011-70, TTK-11-42 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss the prospects of observing double parton scattering (DPS)
processes with purely leptonic final states at the LHC. We first study
same-sign W pair production, which is particularly suited for studying momentum
and valence number conservation effects, followed by discussions on double
Drell-Yan and production of J/psi pairs. The effects of initial state and
intrinsic transverse momentum smearing on pair-wise transverse momentum balance
characteristic to DPS are studied quantitatively. We also present a new
technique, based on rapidity differences, to extract the DPS component from a
double J/psi sample recently studied at the LHCb.
| [
{
"created": "Thu, 6 Oct 2011 08:05:47 GMT",
"version": "v1"
}
] | 2011-10-07 | [
[
"Gaunt",
"Jonathan R.",
""
],
[
"Kom",
"C. H.",
""
],
[
"Kulesza",
"A.",
""
],
[
"Stirling",
"W. J.",
""
]
] | We discuss the prospects of observing double parton scattering (DPS) processes with purely leptonic final states at the LHC. We first study same-sign W pair production, which is particularly suited for studying momentum and valence number conservation effects, followed by discussions on double Drell-Yan and production of J/psi pairs. The effects of initial state and intrinsic transverse momentum smearing on pair-wise transverse momentum balance characteristic to DPS are studied quantitatively. We also present a new technique, based on rapidity differences, to extract the DPS component from a double J/psi sample recently studied at the LHCb. |
hep-ph/0002144 | Daniel Ashery | D. Ashery (Tel Aviv University) and H.J. Lipkin (Weizmann Institute
and Tel Aviv University) | The contribution of $\Sigma^* \to \Lambda\pi$ to measured $\Lambda$
polarization | 6 pages, 1 figure | null | null | null | hep-ph | null | Calculations of the polarization of $\Lambda$ and $\bar{\Lambda}$ particles
after fragmentation of a polarized quark produced in processes like $Z$-decay
and deep inelastic polarized lepton scattering must include $\Lambda$ and
$\bar{\Lambda}$ produced as decay products of $\Sigma^0$ and $\Sigma^*$ as well
as those produced directly. These decay contributions are significant and not
feasibly included in theoretical calculations based on QCD without additional
input from other experimental data. Furthermore these contributions depend on
the spin structure of the $\Sigma^0$ or $\Sigma^*$ and are not directly related
to the structure function of the $\Lambda$
| [
{
"created": "Mon, 14 Feb 2000 12:22:18 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Ashery",
"D.",
"",
"Tel Aviv University"
],
[
"Lipkin",
"H. J.",
"",
"Weizmann Institute\n and Tel Aviv University"
]
] | Calculations of the polarization of $\Lambda$ and $\bar{\Lambda}$ particles after fragmentation of a polarized quark produced in processes like $Z$-decay and deep inelastic polarized lepton scattering must include $\Lambda$ and $\bar{\Lambda}$ produced as decay products of $\Sigma^0$ and $\Sigma^*$ as well as those produced directly. These decay contributions are significant and not feasibly included in theoretical calculations based on QCD without additional input from other experimental data. Furthermore these contributions depend on the spin structure of the $\Sigma^0$ or $\Sigma^*$ and are not directly related to the structure function of the $\Lambda$ |
hep-ph/9603348 | null | Maciej A. Nowak, G\'abor Papp and Ismail Zahed | QCD-Inspired Spectra from Blue's Functions | 7 pages, LaTEX using RevTEX, 7 eps figures included. (comments on the
Wilson fermions added) | Phys.Lett. B389 (1996) 137-143 | 10.1016/S0370-2693(96)01238-5 | null | hep-ph cond-mat hep-lat hep-th | null | We use the law of addition in random matrix theory to analyze the spectral
distributions of a variety of chiral random matrix models as inspired from QCD
whether through symmetries or models. In terms of the Blue's functions recently
discussed by Zee, we show that most of the spectral distributions in the
macroscopic limit and the quenched approximation, follow algebraically from the
discontinuity of a pertinent solution to a cubic (Cardano) or a quartic
(Ferrari) equation. We use the end-point equation of the energy spectra in
chiral random matrix models to argue for novel phase structures, in which the
Dirac density of states plays the role of an order parameter.
| [
{
"created": "Tue, 19 Mar 1996 20:35:48 GMT",
"version": "v1"
},
{
"created": "Sun, 24 Mar 1996 20:14:27 GMT",
"version": "v2"
},
{
"created": "Thu, 4 Apr 1996 09:52:35 GMT",
"version": "v3"
}
] | 2009-10-28 | [
[
"Nowak",
"Maciej A.",
""
],
[
"Papp",
"Gábor",
""
],
[
"Zahed",
"Ismail",
""
]
] | We use the law of addition in random matrix theory to analyze the spectral distributions of a variety of chiral random matrix models as inspired from QCD whether through symmetries or models. In terms of the Blue's functions recently discussed by Zee, we show that most of the spectral distributions in the macroscopic limit and the quenched approximation, follow algebraically from the discontinuity of a pertinent solution to a cubic (Cardano) or a quartic (Ferrari) equation. We use the end-point equation of the energy spectra in chiral random matrix models to argue for novel phase structures, in which the Dirac density of states plays the role of an order parameter. |
1206.1502 | Andrey Tayduganov | Damir Becirevic, Emi Kou, Alain Le Yaouanc and Andrey Tayduganov | Future prospects for the determination of the Wilson coefficient
$C_{7\gamma}^\prime$ | 34 pages, 10 figures | null | 10.1007/JHEP08(2012)090 | LPT-ORSAY 12-38; LAL 12-146 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss the possibilities of assessing a non-zero $C_{7\gamma}^\prime$
from the direct and the indirect measurements of the photon polarization in the
exclusive $b \to s\gamma^{(*)}$ decays. We focus on three methods and explore
the following three decay modes: $B \to K^*(\to K_S\pi^0)\gamma$, $B \to
K_1(\to K\pi\pi)\gamma$, and $B \to K^*(\to K\pi)\ell^+\ell^-$. By studying
different New Physics scenarios we show that the future measurement of
conveniently defined observables in these decays could provide us with the full
determination of $C_{7\gamma}$ and $C_{7\gamma}^\prime$.
| [
{
"created": "Thu, 7 Jun 2012 14:05:40 GMT",
"version": "v1"
},
{
"created": "Fri, 22 Jun 2012 11:58:16 GMT",
"version": "v2"
}
] | 2015-06-05 | [
[
"Becirevic",
"Damir",
""
],
[
"Kou",
"Emi",
""
],
[
"Yaouanc",
"Alain Le",
""
],
[
"Tayduganov",
"Andrey",
""
]
] | We discuss the possibilities of assessing a non-zero $C_{7\gamma}^\prime$ from the direct and the indirect measurements of the photon polarization in the exclusive $b \to s\gamma^{(*)}$ decays. We focus on three methods and explore the following three decay modes: $B \to K^*(\to K_S\pi^0)\gamma$, $B \to K_1(\to K\pi\pi)\gamma$, and $B \to K^*(\to K\pi)\ell^+\ell^-$. By studying different New Physics scenarios we show that the future measurement of conveniently defined observables in these decays could provide us with the full determination of $C_{7\gamma}$ and $C_{7\gamma}^\prime$. |
1812.03028 | Avelino Vicente | Avelino Vicente | Flavor and Dark Matter connection | Contribution to the proceedings of the 16th Conference on Flavor
Physics & CP Violation (FPCP 2018), Hyderabad, India, July 14-18, 2018 | null | null | IFIC/18-45 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In recent years, the LHCb collaboration has published results on the
measurement of several observables associated to semileptonic $b \to s$
transitions. Interestingly, various deviations from their expected values in
the Standard Model have been found, including some tantalizing hints pointing
towards the violation of Lepton Flavor Universality. We discuss New Physics
models that address these anomalies and explore their possible connection to
the dark matter of the Universe.
| [
{
"created": "Fri, 7 Dec 2018 14:05:48 GMT",
"version": "v1"
}
] | 2018-12-10 | [
[
"Vicente",
"Avelino",
""
]
] | In recent years, the LHCb collaboration has published results on the measurement of several observables associated to semileptonic $b \to s$ transitions. Interestingly, various deviations from their expected values in the Standard Model have been found, including some tantalizing hints pointing towards the violation of Lepton Flavor Universality. We discuss New Physics models that address these anomalies and explore their possible connection to the dark matter of the Universe. |
hep-ph/0406284 | Elizabeth Rodriguez Querts | H. Perez Rojas and E. Rodriguez Querts | Vacuum pressures and energy in a strong magnetic field | Presented in the International Workshop on Strong Magnetic Fields and
Neutron Stars, Havana, Cuba, April 2003 | null | null | null | hep-ph | null | We study vacuum in a strong magnetic field. It shows a nonlinear response, as
a ferromagnetic medium. Anisotropic pressures arise, and a negative pressure is
exerted in the direction perpendicular to the field. The analogy of this effect
with the Casimir effect is analyzed. The vacuum transverse pressure is found to
be of the same order of the statistical pressure for $B\sim10^{15}G$ and
$N\sim10^{33}electrons/cm^{3}$. Vacuum interaction with the field is studied
also for $B\sim10^{16}G$ and larger, including the electron anomalous magnetic
moment. We estimate quark contribution to vacuum behavior.
| [
{
"created": "Fri, 25 Jun 2004 09:22:21 GMT",
"version": "v1"
},
{
"created": "Fri, 23 Jul 2004 18:58:24 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Rojas",
"H. Perez",
""
],
[
"Querts",
"E. Rodriguez",
""
]
] | We study vacuum in a strong magnetic field. It shows a nonlinear response, as a ferromagnetic medium. Anisotropic pressures arise, and a negative pressure is exerted in the direction perpendicular to the field. The analogy of this effect with the Casimir effect is analyzed. The vacuum transverse pressure is found to be of the same order of the statistical pressure for $B\sim10^{15}G$ and $N\sim10^{33}electrons/cm^{3}$. Vacuum interaction with the field is studied also for $B\sim10^{16}G$ and larger, including the electron anomalous magnetic moment. We estimate quark contribution to vacuum behavior. |
hep-ph/9905443 | Nir Polonsky | Francesca Borzumati, Jean-Loic Kneur, and Nir Polonsky | Charged Higgs- and R-Parity-Violating Slepton-Strahlung at Hadron
Colliders | 23 pages, LaTex + RevTex, 11 figures (included). Title modified.
(Published version.) | Phys.Rev.D60:115011,1999 | 10.1103/PhysRevD.60.115011 | CERN-TH/99-118, PM/98-38, RU-98-45 | hep-ph | null | It is shown that the radiation of a charged Higgs boson off a
third-generation quark (charged-Higgs-strahlung) provides an important channel
for the discovery of the charged Higgs at hadron colliders. Equivalently, in
supersymmetric models with explicit lepton-number (R-parity) violation,
sleptons may also be produced in association with quarks (slepton-strahlung).
Higgs- and slepton-strahlung production cross sections are given for both the
Tevatron and the LHC. The LHC cross sections imply that heavy ${\cal{O}}$(TeV)
charged Higgs bosons can be produced via charged-Higgs-strahlung and that
strahlung production of charged sleptons is possible even for small R-parity
violating couplings. The possible discovery of sleptons through this channel
offers a surprising handle on models of neutrino masses.
| [
{
"created": "Fri, 21 May 1999 15:58:10 GMT",
"version": "v1"
},
{
"created": "Wed, 12 Jan 2000 19:26:05 GMT",
"version": "v2"
}
] | 2009-07-09 | [
[
"Borzumati",
"Francesca",
""
],
[
"Kneur",
"Jean-Loic",
""
],
[
"Polonsky",
"Nir",
""
]
] | It is shown that the radiation of a charged Higgs boson off a third-generation quark (charged-Higgs-strahlung) provides an important channel for the discovery of the charged Higgs at hadron colliders. Equivalently, in supersymmetric models with explicit lepton-number (R-parity) violation, sleptons may also be produced in association with quarks (slepton-strahlung). Higgs- and slepton-strahlung production cross sections are given for both the Tevatron and the LHC. The LHC cross sections imply that heavy ${\cal{O}}$(TeV) charged Higgs bosons can be produced via charged-Higgs-strahlung and that strahlung production of charged sleptons is possible even for small R-parity violating couplings. The possible discovery of sleptons through this channel offers a surprising handle on models of neutrino masses. |
1904.07558 | Soumita Pramanick | Soumita Pramanick (Harish-Chandra Research Institute, India) | Scotogenic S3 symmetric generation of realistic neutrino mixing | 15 pages, 2 figures, 3 tables, v2: version published in Physical
Review D | Phys. Rev. D 100, 035009 (2019) | 10.1103/PhysRevD.100.035009 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Realistic neutrino mixing is achieved at one-loop level radiatively using
$S3\times Z_2$ symmetry. The model comprises of two right-handed neutrinos,
maximally mixed to produce the structure of the left-handed Majorana neutrino
mass matrix characterized by $\theta_{13}=0$, $\theta_{23}=\pi/4$ and any value
of $\theta_{12}^0$ particular to the Tribimaximal (TBM), Bimaximal (BM) and
Golden Ratio (GR) or other mixings. A small deviation from this maximal mixing
between the two right-handed neutrinos could generate non-zero $\theta_{13}$,
shifts of the atmospheric mixing angle $\theta_{23}$ from $\pi/4$ and also
could correct the solar mixing angle $\theta_{12}$ by a small amount altogether
in a single step. In this scotogenic mechanism of generating non-zero
$\theta_{13}$ by shifting from maximal mixing in the right-handed neutrino
sector, two $Z_2$ odd inert scalar $SU(2)_L$ doublets were used, the lightest
of which can serve as a dark matter candidate.
| [
{
"created": "Tue, 16 Apr 2019 09:44:37 GMT",
"version": "v1"
},
{
"created": "Tue, 17 Sep 2019 07:29:37 GMT",
"version": "v2"
}
] | 2019-09-18 | [
[
"Pramanick",
"Soumita",
"",
"Harish-Chandra Research Institute, India"
]
] | Realistic neutrino mixing is achieved at one-loop level radiatively using $S3\times Z_2$ symmetry. The model comprises of two right-handed neutrinos, maximally mixed to produce the structure of the left-handed Majorana neutrino mass matrix characterized by $\theta_{13}=0$, $\theta_{23}=\pi/4$ and any value of $\theta_{12}^0$ particular to the Tribimaximal (TBM), Bimaximal (BM) and Golden Ratio (GR) or other mixings. A small deviation from this maximal mixing between the two right-handed neutrinos could generate non-zero $\theta_{13}$, shifts of the atmospheric mixing angle $\theta_{23}$ from $\pi/4$ and also could correct the solar mixing angle $\theta_{12}$ by a small amount altogether in a single step. In this scotogenic mechanism of generating non-zero $\theta_{13}$ by shifting from maximal mixing in the right-handed neutrino sector, two $Z_2$ odd inert scalar $SU(2)_L$ doublets were used, the lightest of which can serve as a dark matter candidate. |
hep-ph/0612002 | Hisakazu Minakata | Hisakazu Minakata, Shoichi Uchinami | On in situ Determination of Earth Matter Density in Neutrino Factory | 21 pages, 4 figures, version to appear in PRD | Phys.Rev.D75:073013,2007 | 10.1103/PhysRevD.75.073013 | null | hep-ph hep-ex physics.geo-ph | null | We point out that an accurate in situ determination of the earth matter
density \rho is possible in neutrino factory by placing a detector at the magic
baseline, L = \sqrt{2} \pi / G_{F} N_{e} where N_{e} denotes electron number
density. The accuracy of matter density determination is excellent in a region
of relatively large theta_{13} with fractional uncertainty \delta \rho / \rho
of about 0.43%, 1.3%, and \lsim 3% at 1 sigma CL at sin^2 2theta_{13}=0.1,
10^{-2}, and 3 x 10^{-3}, respectively. At smaller theta_{13} the uncertainty
depends upon the CP phase delta, but it remains small, 3%-7% in more than 3/4
of the entire region of delta at sin^2 2theta_{13} = 10^{-4}. The results would
allow us to solve the problem of obscured CP violation due to the uncertainty
of earth matter density in a wide range of theta_{13} and delta. It may provide
a test for the geophysical model of the earth, or it may serve as a method for
stringent test of the MSW theory of neutrino propagation in matter once an
accurate geophysical estimation of the matter density is available.
| [
{
"created": "Fri, 1 Dec 2006 04:19:02 GMT",
"version": "v1"
},
{
"created": "Sat, 2 Dec 2006 14:23:36 GMT",
"version": "v2"
},
{
"created": "Fri, 16 Mar 2007 09:24:44 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Minakata",
"Hisakazu",
""
],
[
"Uchinami",
"Shoichi",
""
]
] | We point out that an accurate in situ determination of the earth matter density \rho is possible in neutrino factory by placing a detector at the magic baseline, L = \sqrt{2} \pi / G_{F} N_{e} where N_{e} denotes electron number density. The accuracy of matter density determination is excellent in a region of relatively large theta_{13} with fractional uncertainty \delta \rho / \rho of about 0.43%, 1.3%, and \lsim 3% at 1 sigma CL at sin^2 2theta_{13}=0.1, 10^{-2}, and 3 x 10^{-3}, respectively. At smaller theta_{13} the uncertainty depends upon the CP phase delta, but it remains small, 3%-7% in more than 3/4 of the entire region of delta at sin^2 2theta_{13} = 10^{-4}. The results would allow us to solve the problem of obscured CP violation due to the uncertainty of earth matter density in a wide range of theta_{13} and delta. It may provide a test for the geophysical model of the earth, or it may serve as a method for stringent test of the MSW theory of neutrino propagation in matter once an accurate geophysical estimation of the matter density is available. |
hep-ph/0005092 | Elena Boglione | M. Boglione and E. Leader | Semi-inclusive hadron-hadron transverse spin asymmetries and their
implication for polarized DIS | 12 pages, LaTeX. References added | null | null | null | hep-ph | null | We discuss a possible explanation of the 25 year old mystery of the large
transverse spin asymmetries found in many semi-inclusive hadron-hadron
reactions. We obtain the first reliable information about the transverse
polarized quark densities Delta_T q(x) and we find surprising implications for
the usual, longitudinal, polarized DIS. The plan of the presentation is as
follows: 1) A brief reminder about the internal structure of the nucleon. 2)
The transverse asymmetries. 3) Why it is so difficult to explain the
asymmetries. 4) Failure and then success using a new soft mechanism. 5)
implications for polarized DIS.
| [
{
"created": "Wed, 10 May 2000 15:27:17 GMT",
"version": "v1"
},
{
"created": "Fri, 12 May 2000 09:33:55 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Boglione",
"M.",
""
],
[
"Leader",
"E.",
""
]
] | We discuss a possible explanation of the 25 year old mystery of the large transverse spin asymmetries found in many semi-inclusive hadron-hadron reactions. We obtain the first reliable information about the transverse polarized quark densities Delta_T q(x) and we find surprising implications for the usual, longitudinal, polarized DIS. The plan of the presentation is as follows: 1) A brief reminder about the internal structure of the nucleon. 2) The transverse asymmetries. 3) Why it is so difficult to explain the asymmetries. 4) Failure and then success using a new soft mechanism. 5) implications for polarized DIS. |
0901.0248 | Werner Rodejohann | Werner Rodejohann | Deviations from tri-bimaximal mixing | 3 pages. Talk given at NOW2008, Conca Specchiulla, Otranto, Italy,
September 6-13, 2008 | null | 10.1016/j.nuclphysbps.2009.02.078 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Current data indicates that lepton mixing is very close to the tri-bimaximal
mixing scenario. In general, however, one expects deviations from any mixing
scenario. We discuss several examples to perturb tri-bimaximal mixing, namely
soft breaking, renormalization group running and charged lepton corrections. We
also present a convenient parametrization of the PMNS matrix which takes
advantage of the apparently close to tri-bimaximal mixing pattern. Finally, it
is discussed how to generate values of U_{e3} which correspond to the recently
found hint for non-zero U_{e3}.
| [
{
"created": "Fri, 2 Jan 2009 16:21:08 GMT",
"version": "v1"
}
] | 2009-04-13 | [
[
"Rodejohann",
"Werner",
""
]
] | Current data indicates that lepton mixing is very close to the tri-bimaximal mixing scenario. In general, however, one expects deviations from any mixing scenario. We discuss several examples to perturb tri-bimaximal mixing, namely soft breaking, renormalization group running and charged lepton corrections. We also present a convenient parametrization of the PMNS matrix which takes advantage of the apparently close to tri-bimaximal mixing pattern. Finally, it is discussed how to generate values of U_{e3} which correspond to the recently found hint for non-zero U_{e3}. |
1708.00892 | Jos\'e Francisco Zurita | Jose Zurita | Di-Higgs production at the LHC and beyond | Proceedings of the 5th LHCP Conference, Shanghai, 2017. 6 pages, 4
figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this talk I discuss the status and future prospects of testing the Higgs
self-couplings at the High Luminosity LHC (HL-LHC) as well as several Beyond
Standard Model (BSM) scenarios that could be probed via Higgs pair production
in the coming years.
| [
{
"created": "Wed, 2 Aug 2017 18:51:20 GMT",
"version": "v1"
}
] | 2017-08-04 | [
[
"Zurita",
"Jose",
""
]
] | In this talk I discuss the status and future prospects of testing the Higgs self-couplings at the High Luminosity LHC (HL-LHC) as well as several Beyond Standard Model (BSM) scenarios that could be probed via Higgs pair production in the coming years. |
2305.00964 | Ji-Chong Yang Mr | Yu-Chen Guo, Fan Feng, An Di, Shi-Qi Lu, Ji-Chong Yang | MLAnalysis: An open-source program for high energy physics analyses | 21 pages, 4 figures | Computer Physics Communications, Volume 294, January 2024, 108957 | 10.1016/j.cpc.2023.108957 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a python-based program for phenomenological investigations in
particle physics using machine learning algorithms, called \verb"MLAnalysis".
The program is able to convert LHE and LHCO files generated by
\verb"MadGraph5_aMC@NLO" into data sets for machine learning algorithms, which
can analyze the information of the events. At present, it contains three
machine learning (ML) algorithms: isolation forest (IF) algorithm, nested
isolation forest (NIF) algorithm, kmeans anomaly detection (KMAD), and some
basic functionality to analyze the kinematic features of a data set. Users can
use this program to improve the efficiency of searching for new physics
signals.
| [
{
"created": "Mon, 1 May 2023 17:54:07 GMT",
"version": "v1"
},
{
"created": "Tue, 17 Oct 2023 14:26:02 GMT",
"version": "v2"
}
] | 2023-10-18 | [
[
"Guo",
"Yu-Chen",
""
],
[
"Feng",
"Fan",
""
],
[
"Di",
"An",
""
],
[
"Lu",
"Shi-Qi",
""
],
[
"Yang",
"Ji-Chong",
""
]
] | We present a python-based program for phenomenological investigations in particle physics using machine learning algorithms, called \verb"MLAnalysis". The program is able to convert LHE and LHCO files generated by \verb"MadGraph5_aMC@NLO" into data sets for machine learning algorithms, which can analyze the information of the events. At present, it contains three machine learning (ML) algorithms: isolation forest (IF) algorithm, nested isolation forest (NIF) algorithm, kmeans anomaly detection (KMAD), and some basic functionality to analyze the kinematic features of a data set. Users can use this program to improve the efficiency of searching for new physics signals. |
1812.11133 | Simon May | Juri Fiaschi, Michael Klasen, Simon May | Singlet-doublet fermion and triplet scalar dark matter with radiative
neutrino masses | 24 pages, 12 figures; version accepted by and published in JHEP | J. High Energ. Phys. (2019) 2019: 15 | 10.1007/JHEP05(2019)015 | MS-TP-18-33 | hep-ph astro-ph.CO | http://creativecommons.org/licenses/by/4.0/ | We present a detailed study of a combined singlet-doublet fermion and triplet
scalar model for dark matter. These models have only been studied separately in
the past. Together, they form a simple extension of the Standard Model that can
account for dark matter and explain the existence of neutrino masses, which are
generated radiatively. This holds even if singlet-doublet fermions and triplet
scalars never contribute simultaneously to the dark matter abundance. However,
this also implies the existence of lepton flavour violating processes. In
addition, this particular model allows for gauge coupling unification. The new
fields are odd under a new $\mathbb{Z}_2$ symmetry to stabilise the dark matter
candidate. We analyse the dark matter, neutrino mass and lepton flavour
violation aspects both separately and in conjunction, exploring the viable
parameter space of the model. This is done using a numerical random scan
imposing successively the neutrino mass and mixing, relic density, Higgs mass,
direct detection, collider and lepton flavour violation constraints. We find
that dark matter in this model is fermionic for masses below about 1 TeV and
scalar above. The narrow mass regions found previously for the two separate
models are enlarged by their coupling. While coannihilations of the weak
isospin partners are sizeable, this is not the case for fermions and scalars
despite their often similar masses due to the relatively small coupling of the
two sectors, imposed by the small neutrino masses. We observe a high degree of
complementarity between direct detection and lepton flavour violation
experiments, which should soon allow to fully probe the fermionic dark matter
sector and at least partially the scalar dark matter sector.
| [
{
"created": "Fri, 28 Dec 2018 17:53:06 GMT",
"version": "v1"
},
{
"created": "Tue, 7 May 2019 22:47:12 GMT",
"version": "v2"
}
] | 2019-05-09 | [
[
"Fiaschi",
"Juri",
""
],
[
"Klasen",
"Michael",
""
],
[
"May",
"Simon",
""
]
] | We present a detailed study of a combined singlet-doublet fermion and triplet scalar model for dark matter. These models have only been studied separately in the past. Together, they form a simple extension of the Standard Model that can account for dark matter and explain the existence of neutrino masses, which are generated radiatively. This holds even if singlet-doublet fermions and triplet scalars never contribute simultaneously to the dark matter abundance. However, this also implies the existence of lepton flavour violating processes. In addition, this particular model allows for gauge coupling unification. The new fields are odd under a new $\mathbb{Z}_2$ symmetry to stabilise the dark matter candidate. We analyse the dark matter, neutrino mass and lepton flavour violation aspects both separately and in conjunction, exploring the viable parameter space of the model. This is done using a numerical random scan imposing successively the neutrino mass and mixing, relic density, Higgs mass, direct detection, collider and lepton flavour violation constraints. We find that dark matter in this model is fermionic for masses below about 1 TeV and scalar above. The narrow mass regions found previously for the two separate models are enlarged by their coupling. While coannihilations of the weak isospin partners are sizeable, this is not the case for fermions and scalars despite their often similar masses due to the relatively small coupling of the two sectors, imposed by the small neutrino masses. We observe a high degree of complementarity between direct detection and lepton flavour violation experiments, which should soon allow to fully probe the fermionic dark matter sector and at least partially the scalar dark matter sector. |
hep-ph/9503496 | Afsar Abbas | Afsar Abbas | Phase Transition in the Early Universe and Charge Quantisation | 7 pages | null | null | IP/BBSR/95-26 | hep-ph astro-ph | null | It is shown, for the first time , that surprisingly the electric charge loses
all physical meaning above the electro-weak phase transition temperature.
Implications of this discovery in the context of the early universe within the
framework of various unified models are discussed.
| [
{
"created": "Fri, 31 Mar 1995 18:09:08 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Abbas",
"Afsar",
""
]
] | It is shown, for the first time , that surprisingly the electric charge loses all physical meaning above the electro-weak phase transition temperature. Implications of this discovery in the context of the early universe within the framework of various unified models are discussed. |
1112.5734 | Alexander Bylinkin | A. A. Bylinkin (1), A. A. Rostovtsev (1) ((1) Institute for
Theoretical and Experimental Physics, ITEP, Moscow, Russia) | Anomalous behavior of pion production in high energy particle collisions | 4 pages, 6 figures | null | 10.1140/epjc/s10052-012-1961-x | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A shape of invariant differential cross section for charged hadron production
as function of transverse momentum measured in various collider experiments is
analyzed. Contrary to the behavior of produced charged kaons, protons and
antiprotons, the pion spectra require an anomalously high contribution of an
exponential term to describe the shape.
| [
{
"created": "Sat, 24 Dec 2011 15:55:23 GMT",
"version": "v1"
}
] | 2015-06-03 | [
[
"Bylinkin",
"A. A.",
""
],
[
"Rostovtsev",
"A. A.",
""
]
] | A shape of invariant differential cross section for charged hadron production as function of transverse momentum measured in various collider experiments is analyzed. Contrary to the behavior of produced charged kaons, protons and antiprotons, the pion spectra require an anomalously high contribution of an exponential term to describe the shape. |
1406.3262 | Marco Zaro | F. Maltoni, M. L. Mangano, I. Tsinikos, M. Zaro | Top-quark charge asymmetry and polarization in $t\bar{t}W^\pm$
production at the LHC | 11 pages (with figures), version accepted by PLB for publication | null | 10.1016/j.physletb.2014.07.033 | CP3-14-23, CERN-PH-TH-2014-102, LPN14-075 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the charge asymmetry between the $t$ and $\bar t$ quark at the LHC,
when they are produced in association with a $W$ boson. Though sizably reducing
the cross section with respect to the inclusive production, requiring a $W$
boson in the final state has two important implications. First, at leading
order in QCD, $t \bar t W^{\pm}$ production can only occur via $q \bar q$
annihilation. As a result, the asymmetry between the $t$ and $\bar t$ generated
at NLO in QCD is significantly larger than that of inclusive $t \bar t$
production, which is dominated by gluon fusion. Second, the top quarks tend to
inherit the polarization of the initial-state quarks as induced by the
$W$-boson emission. Hence, the decay products of the top quarks display a
sizable asymmetry already at the leading order in QCD. We study the relevant
distributions and their uncertainties in the standard model, compare them to
those obtained in a simple axigluon model and discuss prospects for
measurements at the LHC and beyond.
| [
{
"created": "Thu, 12 Jun 2014 15:04:26 GMT",
"version": "v1"
},
{
"created": "Fri, 25 Jul 2014 08:10:32 GMT",
"version": "v2"
}
] | 2015-06-19 | [
[
"Maltoni",
"F.",
""
],
[
"Mangano",
"M. L.",
""
],
[
"Tsinikos",
"I.",
""
],
[
"Zaro",
"M.",
""
]
] | We study the charge asymmetry between the $t$ and $\bar t$ quark at the LHC, when they are produced in association with a $W$ boson. Though sizably reducing the cross section with respect to the inclusive production, requiring a $W$ boson in the final state has two important implications. First, at leading order in QCD, $t \bar t W^{\pm}$ production can only occur via $q \bar q$ annihilation. As a result, the asymmetry between the $t$ and $\bar t$ generated at NLO in QCD is significantly larger than that of inclusive $t \bar t$ production, which is dominated by gluon fusion. Second, the top quarks tend to inherit the polarization of the initial-state quarks as induced by the $W$-boson emission. Hence, the decay products of the top quarks display a sizable asymmetry already at the leading order in QCD. We study the relevant distributions and their uncertainties in the standard model, compare them to those obtained in a simple axigluon model and discuss prospects for measurements at the LHC and beyond. |
1604.04791 | Gerhard Mallot | F. Bradamante and G.K. Mallot | Why there is no crisis of the "spin crisis" | 2 pages, no figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In a recent eprint [1] it is argued that the experimental determinations of
the spin-dependent structure function g1 have been done incorrectly and that a
reanalysis of those data suggests that the original motivation to argue fora
"spin crisis", namely the small contribution of quark spins to the nucleon
spin, is invalid. In a subsequent note [2] the theoretical understanding, as it
has evolved from almost 30 years of theoretical and experimental scrutiny, has
been shortly summarised. In this short note, arguments are presented that the
line of reasoning in Ref. [1] does not apply, at least not for the Compass
data.
| [
{
"created": "Sat, 16 Apr 2016 20:20:33 GMT",
"version": "v1"
}
] | 2016-04-19 | [
[
"Bradamante",
"F.",
""
],
[
"Mallot",
"G. K.",
""
]
] | In a recent eprint [1] it is argued that the experimental determinations of the spin-dependent structure function g1 have been done incorrectly and that a reanalysis of those data suggests that the original motivation to argue fora "spin crisis", namely the small contribution of quark spins to the nucleon spin, is invalid. In a subsequent note [2] the theoretical understanding, as it has evolved from almost 30 years of theoretical and experimental scrutiny, has been shortly summarised. In this short note, arguments are presented that the line of reasoning in Ref. [1] does not apply, at least not for the Compass data. |
hep-ph/9603287 | Le Yaouanc | A. Le Yaouanc, L. Oliver, O. P\`ene and J.-C. Raynal | Exact Duality and Bjorken Sum Rule in Heavy Quark Models \`a la
Bakamjian-Thomas | 14 pages | Phys.Lett. B386 (1996) 304-314 | 10.1016/0370-2693(96)00971-9 | LPTHE-Orsay 96/05 | hep-ph | null | The heavy mass limit of quark models based on the Bakamjian-Thomas
cons\-truction reveals remarkable features. In addition to previously
demonstrated properties of covariance and Isgur-Wise scaling, exact duality,
leading to the Bjorken-Isgur-Wise sum rule, is proven, for the first time to
our knowledge in relativistic quark models. Inelastic as well as elastic
contributions to the sum rule are then discussed in terms of ground state
averages of a few number of operators corresponding to the nonrelativistic
dipole operator and various relativistic corrections.
| [
{
"created": "Tue, 12 Mar 1996 17:42:33 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Yaouanc",
"A. Le",
""
],
[
"Oliver",
"L.",
""
],
[
"Pène",
"O.",
""
],
[
"Raynal",
"J. -C.",
""
]
] | The heavy mass limit of quark models based on the Bakamjian-Thomas cons\-truction reveals remarkable features. In addition to previously demonstrated properties of covariance and Isgur-Wise scaling, exact duality, leading to the Bjorken-Isgur-Wise sum rule, is proven, for the first time to our knowledge in relativistic quark models. Inelastic as well as elastic contributions to the sum rule are then discussed in terms of ground state averages of a few number of operators corresponding to the nonrelativistic dipole operator and various relativistic corrections. |
hep-ph/9809331 | Zhang Ai Lin | Tao Huang, Hongying Jin, Ailin Zhang | The $0^{++}$ and $0^{-+}$ mass of light-quark hybrid in QCD sum rules | 11 pages, Latex, 5 ps figures | Eur.Phys.J.C8:465-471,1999 | 10.1007/s100529901071 | null | hep-ph | null | We calculate masses of the light-quark hybrid mesons with the quantum number
$0^{++}$ and $0^{-+}$ by using the QCD sum rules. Two kinds of the interpolated
currents with the same quantum number are employed. We find that the
approximately equal mass is predicted for the $0^{-+}$ hybrid state from the
different current and the different mass is obtained for the $0^{++}$ hybrid
state from the different current. The prediction depends on the interaction
between the gluon and quarks in the low-lying hybrid mesons. The mixing effect
on the mass of the light-quark hybrid meson through Low-energy theorem has been
examined too, and it is found that this mixing shifts the mass of hybrid meson
and glueball a little.
| [
{
"created": "Fri, 11 Sep 1998 02:29:43 GMT",
"version": "v1"
}
] | 2011-09-13 | [
[
"Huang",
"Tao",
""
],
[
"Jin",
"Hongying",
""
],
[
"Zhang",
"Ailin",
""
]
] | We calculate masses of the light-quark hybrid mesons with the quantum number $0^{++}$ and $0^{-+}$ by using the QCD sum rules. Two kinds of the interpolated currents with the same quantum number are employed. We find that the approximately equal mass is predicted for the $0^{-+}$ hybrid state from the different current and the different mass is obtained for the $0^{++}$ hybrid state from the different current. The prediction depends on the interaction between the gluon and quarks in the low-lying hybrid mesons. The mixing effect on the mass of the light-quark hybrid meson through Low-energy theorem has been examined too, and it is found that this mixing shifts the mass of hybrid meson and glueball a little. |
1708.06284 | Cesar Ayala | Cesar Ayala, Gorazd Cvetic, Anatoly V. Kotikov, Binur G. Shaikhatdenov | Bjorken sum rule in QCD frameworks with analytic (holomorphic) coupling | 22 pages, 6 figures; v3: improved text, to appear in Int.J.Mod.Phys.A | Int.J.Mod.Phys. A33 (2018) no.18n19, 1850112 | 10.1142/S0217751X18501129 | USM-TH-353 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the Bjorken polarized sum rule (BSR) in three approaches to
QCD with analytic (holomorphic) coupling: Analytic Perturbation Theory (APT),
Two-delta analytic QCD (2$\delta$anQCD), and Three-delta lattice-motivated
analytic QCD in the three-loop and four-loop MOM scheme (3l3$\delta$anQCD,
4l3$\delta$anQCD). These couplings do not have unphysical (Landau)
singularities, and have finite values when the transferred momentum goes to
zero, which allows us to explore the infrared regime. With the exception of
APT, these theories at high momenta practically coincide with the underlying
perturbative QCD (pQCD) in the same scheme. We apply them in order to verify
the Bjorken sum rule within the range of energies available in the data
collected by the experimental JLAB collaboration, i.e., $0.05 GeV^2 <Q^2< 3
GeV^2$ and compare the results with those obtained by using the perturbative
QCD coupling. The results of the new frameworks with respective couplings
(2$\delta$ and 3$\delta$) are in good agreement with the experimental data for
$0.5 GeV^2<Q^2<3 GeV^2$ already when only one higher-twist term is used. In the
low-$Q^2$ regime ($Q^2 \lesssim 1 GeV^2$) we use $\chi$PT-motivated expression
or an expression motivated by the light-front holography (LFH) QCD used earlier
in the literature.
| [
{
"created": "Mon, 21 Aug 2017 15:23:55 GMT",
"version": "v1"
},
{
"created": "Tue, 29 Aug 2017 20:26:06 GMT",
"version": "v2"
},
{
"created": "Wed, 13 Jun 2018 19:20:51 GMT",
"version": "v3"
}
] | 2018-07-10 | [
[
"Ayala",
"Cesar",
""
],
[
"Cvetic",
"Gorazd",
""
],
[
"Kotikov",
"Anatoly V.",
""
],
[
"Shaikhatdenov",
"Binur G.",
""
]
] | We investigate the Bjorken polarized sum rule (BSR) in three approaches to QCD with analytic (holomorphic) coupling: Analytic Perturbation Theory (APT), Two-delta analytic QCD (2$\delta$anQCD), and Three-delta lattice-motivated analytic QCD in the three-loop and four-loop MOM scheme (3l3$\delta$anQCD, 4l3$\delta$anQCD). These couplings do not have unphysical (Landau) singularities, and have finite values when the transferred momentum goes to zero, which allows us to explore the infrared regime. With the exception of APT, these theories at high momenta practically coincide with the underlying perturbative QCD (pQCD) in the same scheme. We apply them in order to verify the Bjorken sum rule within the range of energies available in the data collected by the experimental JLAB collaboration, i.e., $0.05 GeV^2 <Q^2< 3 GeV^2$ and compare the results with those obtained by using the perturbative QCD coupling. The results of the new frameworks with respective couplings (2$\delta$ and 3$\delta$) are in good agreement with the experimental data for $0.5 GeV^2<Q^2<3 GeV^2$ already when only one higher-twist term is used. In the low-$Q^2$ regime ($Q^2 \lesssim 1 GeV^2$) we use $\chi$PT-motivated expression or an expression motivated by the light-front holography (LFH) QCD used earlier in the literature. |
1010.3077 | Rohit Dhir | Neelesh Sharma, Rohit Dhir, R.C. Verma | Decays of bottom mesons emitting tensor meson in final state using ISGW
II model | 32 pages, to be published in Phys. Rev. D | Phys.Rev.D83:014007,2011 | 10.1103/PhysRevD.83.014007 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper, we investigate phenomenologically two-body weak decays of the
bottom mesons emitting pseudoscalar/vector meson and a tensor meson. Form
factors are obtained using the improved ISGW II model. Consequently, branching
ratios for the CKM-favored and CKM-suppressed decays are calculated.
| [
{
"created": "Fri, 15 Oct 2010 06:24:47 GMT",
"version": "v1"
}
] | 2011-02-02 | [
[
"Sharma",
"Neelesh",
""
],
[
"Dhir",
"Rohit",
""
],
[
"Verma",
"R. C.",
""
]
] | In this paper, we investigate phenomenologically two-body weak decays of the bottom mesons emitting pseudoscalar/vector meson and a tensor meson. Form factors are obtained using the improved ISGW II model. Consequently, branching ratios for the CKM-favored and CKM-suppressed decays are calculated. |
1804.03657 | Dreyer Fr\'ed\'eric | Fr\'ed\'eric A. Dreyer, Lina Necib, Gregory Soyez, and Jesse Thaler | Recursive Soft Drop | 20+14 pages, 17 figures, v2 updated to match published version | null | 10.1007/JHEP06(2018)093 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We introduce a new jet substructure technique called Recursive Soft Drop,
which generalizes the Soft Drop algorithm to have multiple grooming layers.
Like the original Soft Drop method, this new recursive variant traverses a jet
clustering tree to remove soft wide-angle contamination. By enforcing the Soft
Drop condition N times, Recursive Soft Drop improves the jet mass resolution
for boosted hadronic objects like W bosons, top quarks, and Higgs bosons. We
further show that this improvement in mass resolution persists when including
the effects of pileup, up to large pileup multiplicities. In the limit that N
goes to infinity, the resulting groomed jets formally have zero catchment area.
As an alternative approach, we present a bottom-up version of Recursive Soft
Drop which, in its local form, is similar to Recursive Soft Drop and which, in
its global form, can be used to perform event-wide grooming.
| [
{
"created": "Tue, 10 Apr 2018 18:00:00 GMT",
"version": "v1"
},
{
"created": "Fri, 29 Jun 2018 03:40:32 GMT",
"version": "v2"
}
] | 2018-08-01 | [
[
"Dreyer",
"Frédéric A.",
""
],
[
"Necib",
"Lina",
""
],
[
"Soyez",
"Gregory",
""
],
[
"Thaler",
"Jesse",
""
]
] | We introduce a new jet substructure technique called Recursive Soft Drop, which generalizes the Soft Drop algorithm to have multiple grooming layers. Like the original Soft Drop method, this new recursive variant traverses a jet clustering tree to remove soft wide-angle contamination. By enforcing the Soft Drop condition N times, Recursive Soft Drop improves the jet mass resolution for boosted hadronic objects like W bosons, top quarks, and Higgs bosons. We further show that this improvement in mass resolution persists when including the effects of pileup, up to large pileup multiplicities. In the limit that N goes to infinity, the resulting groomed jets formally have zero catchment area. As an alternative approach, we present a bottom-up version of Recursive Soft Drop which, in its local form, is similar to Recursive Soft Drop and which, in its global form, can be used to perform event-wide grooming. |
hep-ph/0503103 | Pedro Jimenez Delgado | M. Gl\"uck, P. Jimenez-Delgado, E. Reya | Radiatively Generated Isospin Violations in the Nucleon and the NuTeV
Anomaly | 10 pages, 2 figures | Phys.Rev.Lett. 95 (2005) 022002 | 10.1103/PhysRevLett.95.022002 | DO-TH 2005/03 | hep-ph | null | Predictions of isospin asymmetries of valence and sea distributions are
presented which are generated by QED leading ${\cal{O}}(\alpha)$ photon
bremsstrahlung effects. Together with isospin violations arising from
nonperturbative hadronic sources (such as quark and target mass differences) as
well as with even a conservative contribution from a strangeness asymmetry
($s\neq \bar{s}$), the discrepancy between the large NuTeV `anomaly' result for
$\sin^2\theta_W$ and the world average of other measurements is removed.
| [
{
"created": "Fri, 11 Mar 2005 10:24:02 GMT",
"version": "v1"
}
] | 2009-11-11 | [
[
"Glück",
"M.",
""
],
[
"Jimenez-Delgado",
"P.",
""
],
[
"Reya",
"E.",
""
]
] | Predictions of isospin asymmetries of valence and sea distributions are presented which are generated by QED leading ${\cal{O}}(\alpha)$ photon bremsstrahlung effects. Together with isospin violations arising from nonperturbative hadronic sources (such as quark and target mass differences) as well as with even a conservative contribution from a strangeness asymmetry ($s\neq \bar{s}$), the discrepancy between the large NuTeV `anomaly' result for $\sin^2\theta_W$ and the world average of other measurements is removed. |
2402.18460 | Krzysztof M\k{e}ka{\l}a | Kateryna Korshynska, Maximilian L\"oschner, Mariia Marinichenko,
Krzysztof M\k{e}ka{\l}a, J\"urgen Reuter | Z' boson mass reach and model discrimination at muon colliders | 14 pages, 7 figures | null | null | DESY-24-028 | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We study the discrimination power of future multi-TeV muon colliders for a
large set of models with extended gauge symmetries and additional neutral gauge
bosons ("$Z'$-models"). Our study is carried out using a $\chi^2$-analysis of
leptonic observables of s-channel scattering in effective $Z'$-models. We make
use of angular and chiral asymmetries induced in such models to find the
discovery reach of a given muon collider setup in terms of the $Z'$ mass and to
discriminate between the different scenarios. In this context, we discuss how
polarized beams - should they become available at muon colliders - or
polarization measurements can help in the discrimination. Our results show that
typical muon collider setups which are currently under consideration can give a
significantly higher reach compared to existing bounds and projections for
high-luminosity LHC.
| [
{
"created": "Wed, 28 Feb 2024 16:36:44 GMT",
"version": "v1"
}
] | 2024-02-29 | [
[
"Korshynska",
"Kateryna",
""
],
[
"Löschner",
"Maximilian",
""
],
[
"Marinichenko",
"Mariia",
""
],
[
"Mękała",
"Krzysztof",
""
],
[
"Reuter",
"Jürgen",
""
]
] | We study the discrimination power of future multi-TeV muon colliders for a large set of models with extended gauge symmetries and additional neutral gauge bosons ("$Z'$-models"). Our study is carried out using a $\chi^2$-analysis of leptonic observables of s-channel scattering in effective $Z'$-models. We make use of angular and chiral asymmetries induced in such models to find the discovery reach of a given muon collider setup in terms of the $Z'$ mass and to discriminate between the different scenarios. In this context, we discuss how polarized beams - should they become available at muon colliders - or polarization measurements can help in the discrimination. Our results show that typical muon collider setups which are currently under consideration can give a significantly higher reach compared to existing bounds and projections for high-luminosity LHC. |
hep-ph/9205216 | Juan Garcia-Bellido | Juan Garcia-Bellido | Dark Matter with Variable Masses | 14pp., LaTeX, no figures, preprint IEM-FT-54/92 | Int.J.Mod.Phys.D2:85-95,1993 | 10.1142/S0218271893000076 | null | hep-ph | null | String effective theories contain a dilaton scalar field which couples to
gravity, matter and radiation. In general, particle masses will have different
dilaton couplings. We can always choose a conformal frame in which baryons have
constant masses while (non--baryonic) dark matter have variable masses, in the
context of a scalar--tensor gravity theory. We are interested in the
phenomenology of this scenario. Dark matter with variable masses could have a
measurable effect on the dynamical motion of the halo of spiral galaxies, which
may affect cold dark matter models of galaxy formation. As a consequence of
variable masses, the energy--momentum tensor is not conserved; there is a
dissipative effect, due to the dilaton coupling, associated with a ``dark
entropy" production. In particular, if axions had variable masses they could be
diluted away, thus opening the ``axion window". Assuming that dark matter with
variable masses dominates the cosmological evolution during the matter era, it
will affect the primordial nucleosynthesis predictions on the abundances of
light elements. Furthermore, the dilaton also couples to radiation in the form
of a variable gauge coupling. Experimental bounds will constrain the parameters
of this model.
| [
{
"created": "Mon, 11 May 1992 10:17:41 GMT",
"version": "v1"
}
] | 2010-11-30 | [
[
"Garcia-Bellido",
"Juan",
""
]
] | String effective theories contain a dilaton scalar field which couples to gravity, matter and radiation. In general, particle masses will have different dilaton couplings. We can always choose a conformal frame in which baryons have constant masses while (non--baryonic) dark matter have variable masses, in the context of a scalar--tensor gravity theory. We are interested in the phenomenology of this scenario. Dark matter with variable masses could have a measurable effect on the dynamical motion of the halo of spiral galaxies, which may affect cold dark matter models of galaxy formation. As a consequence of variable masses, the energy--momentum tensor is not conserved; there is a dissipative effect, due to the dilaton coupling, associated with a ``dark entropy" production. In particular, if axions had variable masses they could be diluted away, thus opening the ``axion window". Assuming that dark matter with variable masses dominates the cosmological evolution during the matter era, it will affect the primordial nucleosynthesis predictions on the abundances of light elements. Furthermore, the dilaton also couples to radiation in the form of a variable gauge coupling. Experimental bounds will constrain the parameters of this model. |
hep-ph/0508057 | Gleb Fedotov V | I.G. Aznauryan, V.D.Burkert, G.V. Fedotov, B.S. Ishkhanov, V.I. Mokeev | Electroexcitation of nucleon resonances at Q^2=0.65 GeV/c^2 from a
combined analysis of single- and double-pion electroproduction data | 12 pages, 12 figures (eps), Published in PHYSICAL REVIEW C 72, 045201
(2005) | Phys.Rev.C72:045201,2005 | 10.1103/PhysRevC.72.045201 | JLAB-PHY-05-392 | hep-ph | null | Data on single- and double-charged pion electroproduction off protons are
successfully described in the second and third nucleon resonance regions with
common N* photocouplings. The analysis was carried out using separate isobar
models for both reactions. From the combined analysis of two exclusive
channels, the gamma* p --> N*+ helicity amplitudes are obtained for the
resonances P11(1440), D13(1520), S31(1620), S11(1650), F15(1680), D33(1700),
D13(1700), and P13(1720) at Q2=0.65 GeV/c^2.
| [
{
"created": "Thu, 4 Aug 2005 13:35:01 GMT",
"version": "v1"
},
{
"created": "Wed, 19 Oct 2005 22:29:40 GMT",
"version": "v2"
},
{
"created": "Fri, 21 Oct 2005 03:51:52 GMT",
"version": "v3"
}
] | 2014-11-18 | [
[
"Aznauryan",
"I. G.",
""
],
[
"Burkert",
"V. D.",
""
],
[
"Fedotov",
"G. V.",
""
],
[
"Ishkhanov",
"B. S.",
""
],
[
"Mokeev",
"V. I.",
""
]
] | Data on single- and double-charged pion electroproduction off protons are successfully described in the second and third nucleon resonance regions with common N* photocouplings. The analysis was carried out using separate isobar models for both reactions. From the combined analysis of two exclusive channels, the gamma* p --> N*+ helicity amplitudes are obtained for the resonances P11(1440), D13(1520), S31(1620), S11(1650), F15(1680), D33(1700), D13(1700), and P13(1720) at Q2=0.65 GeV/c^2. |
2010.16334 | Monojit Ghosh | Sandhya Choubey, Monojit Ghosh, Daniel Kempe and Tommy Ohlsson | Exploring invisible neutrino decay at ESSnuSB | 22 pages, 10 figures, 4 tables, Version accepted for publication in
JHEP | null | 10.1007/JHEP05(2021)133 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We explore invisible neutrino decay in which a heavy active neutrino state
decays into a light sterile neutrino state and present a comparative analysis
of two baseline options, $540~$km and $360~$km, for the ESSnuSB experimental
setup. Our analysis shows that ESSnuSB can put a bound on the decay parameter
$\tau_3/m_3 = 2.64~(1.68) \times 10^{-11}~$s/eV for the baseline option of
$360~(540)~$km at $3 \sigma$. The expected bound obtained for $360~$km is
slightly better than the corresponding one of DUNE for a charged current (CC)
analysis. Furthermore, we show that the capability of ESSnuSB to discover
decay, and to measure the decay parameter precisely, is better for the baseline
option of $540~$km than that of $360~$km. Regarding effects of decay in
$\delta_{\rm CP}$ measurements, we find that in general the CP violation
discovery potential is better in the presence of decay. The change in CP
precision is significant if one assumes decay in data but no decay in theory.
| [
{
"created": "Fri, 30 Oct 2020 15:48:16 GMT",
"version": "v1"
},
{
"created": "Tue, 11 May 2021 15:15:22 GMT",
"version": "v2"
}
] | 2021-06-02 | [
[
"Choubey",
"Sandhya",
""
],
[
"Ghosh",
"Monojit",
""
],
[
"Kempe",
"Daniel",
""
],
[
"Ohlsson",
"Tommy",
""
]
] | We explore invisible neutrino decay in which a heavy active neutrino state decays into a light sterile neutrino state and present a comparative analysis of two baseline options, $540~$km and $360~$km, for the ESSnuSB experimental setup. Our analysis shows that ESSnuSB can put a bound on the decay parameter $\tau_3/m_3 = 2.64~(1.68) \times 10^{-11}~$s/eV for the baseline option of $360~(540)~$km at $3 \sigma$. The expected bound obtained for $360~$km is slightly better than the corresponding one of DUNE for a charged current (CC) analysis. Furthermore, we show that the capability of ESSnuSB to discover decay, and to measure the decay parameter precisely, is better for the baseline option of $540~$km than that of $360~$km. Regarding effects of decay in $\delta_{\rm CP}$ measurements, we find that in general the CP violation discovery potential is better in the presence of decay. The change in CP precision is significant if one assumes decay in data but no decay in theory. |
1005.3305 | Markos Maniatis | Ernest Ma, Markos Maniatis | Effective Two Higgs Doublets in Nonminimal Supersymmetric Models | 8 pages, 1 table, 3 figures | Eur.Phys.J.C71:1610,2011 | 10.1140/epjc/s10052-011-1610-9 | UCRHEP-T491, HD-THEP-10-9 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The Higgs sectors of supersymmetric extensions of the Standard Model have two
doublets in the minimal version (MSSM), and two doublets plus a singlet in two
others: with (UMSSM) and without (NMSSM) an extra U(1)'. A very concise
comparison of these three models is possible if we assume that the singlet has
a somewhat larger breaking scale compared to the electroweak scale. In that
case, the UMSSM and the NMSSM become effectively two-Higgs-doublet models
(THDM), like the MSSM. As expected, the mass of the lightest CP-even neutral
Higgs boson has an upper bound in each case. We find that in the NMSSM, this
bound exceeds not very much that of the MSSM, unless tan(beta) is near one.
However, the upper bound in the UMSSM may be substantially enhanced.
| [
{
"created": "Tue, 18 May 2010 20:00:05 GMT",
"version": "v1"
}
] | 2011-04-20 | [
[
"Ma",
"Ernest",
""
],
[
"Maniatis",
"Markos",
""
]
] | The Higgs sectors of supersymmetric extensions of the Standard Model have two doublets in the minimal version (MSSM), and two doublets plus a singlet in two others: with (UMSSM) and without (NMSSM) an extra U(1)'. A very concise comparison of these three models is possible if we assume that the singlet has a somewhat larger breaking scale compared to the electroweak scale. In that case, the UMSSM and the NMSSM become effectively two-Higgs-doublet models (THDM), like the MSSM. As expected, the mass of the lightest CP-even neutral Higgs boson has an upper bound in each case. We find that in the NMSSM, this bound exceeds not very much that of the MSSM, unless tan(beta) is near one. However, the upper bound in the UMSSM may be substantially enhanced. |
hep-ph/0409247 | Ansgar Denner | E. Accomando, A. Denner, A. Kaiser | Logarithmic electroweak corrections to gauge-boson pair production at
the LHC | 47 pages, LaTeX, 18 eps figures | Nucl.Phys.B706:325-371,2005 | 10.1016/j.nuclphysb.2004.11.019 | PSI-PR-04-08, ZU-TH 13/04, DFTT 19/04 | hep-ph | null | We have studied the effects of the complete logarithmic electroweak O(alpha)
corrections on the production of vector-boson pairs WZ, ZZ, and WW at the LHC.
These corrections are implemented into a Monte Carlo program for pp -> 4f
(+\gamma) with final states involving four or two leptons using the double-pole
approximation. We numerically investigate purely leptonic final states and find
that electroweak corrections lower the predictions by 5-30% in the physically
interesting region of large di-boson invariant mass and large angle of the
produced vector bosons.
| [
{
"created": "Tue, 21 Sep 2004 14:16:41 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Accomando",
"E.",
""
],
[
"Denner",
"A.",
""
],
[
"Kaiser",
"A.",
""
]
] | We have studied the effects of the complete logarithmic electroweak O(alpha) corrections on the production of vector-boson pairs WZ, ZZ, and WW at the LHC. These corrections are implemented into a Monte Carlo program for pp -> 4f (+\gamma) with final states involving four or two leptons using the double-pole approximation. We numerically investigate purely leptonic final states and find that electroweak corrections lower the predictions by 5-30% in the physically interesting region of large di-boson invariant mass and large angle of the produced vector bosons. |
0811.3775 | Gerhart Seidl | Gerhart Seidl | Unified model of fermion masses with Wilson line flavor symmetry
breaking | 12 pages, 1 figure, 1 table, discussion of Wilson lines extended,
comments on symmetries added, effect of CP-violating phases included, typos
corrected, final version to appear in Phys. Rev. D | Phys.Rev.D81:025004,2010 | 10.1103/PhysRevD.81.025004 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a supersymmetric SU(5) GUT model with a discrete non-Abelian
flavor symmetry that is broken by Wilson lines. The model is formulated in 4+3
dimensions compactified on a manifold S^3/Z_n. Symmetry breaking by Wilson
lines is topological and allows to realize the necessary flavor symmetry
breaking without a vacuum alignment mechanism. The model predicts the
hierarchical pattern of charged fermion masses and quark mixing angles. Small
normal hierarchical neutrino masses are generated by the type-I seesaw
mechanism. The non-Abelian flavor symmetry predicts to leading order exact
maximal atmospheric mixing while the solar angle emerges from a variant of
quark-lepton complementarity. As a consequence, the resulting leptonic mixing
matrix is in excellent agreement with current data and could be tested in
future neutrino oscillation experiments.
| [
{
"created": "Mon, 24 Nov 2008 17:08:29 GMT",
"version": "v1"
},
{
"created": "Mon, 21 Dec 2009 21:02:27 GMT",
"version": "v2"
}
] | 2010-04-06 | [
[
"Seidl",
"Gerhart",
""
]
] | We present a supersymmetric SU(5) GUT model with a discrete non-Abelian flavor symmetry that is broken by Wilson lines. The model is formulated in 4+3 dimensions compactified on a manifold S^3/Z_n. Symmetry breaking by Wilson lines is topological and allows to realize the necessary flavor symmetry breaking without a vacuum alignment mechanism. The model predicts the hierarchical pattern of charged fermion masses and quark mixing angles. Small normal hierarchical neutrino masses are generated by the type-I seesaw mechanism. The non-Abelian flavor symmetry predicts to leading order exact maximal atmospheric mixing while the solar angle emerges from a variant of quark-lepton complementarity. As a consequence, the resulting leptonic mixing matrix is in excellent agreement with current data and could be tested in future neutrino oscillation experiments. |
hep-ph/9701314 | Andrea Erdas | A. Erdas, C. W. Kim, T. H. Lee | Magnetic properties of neutrinos in high temperature SU(2)XU(1) gauge
theory | 13 pp, RevTeX, no figures | Phys.Lett. B406 (1997) 347-354 | 10.1016/S0370-2693(97)00699-0 | JHU-TIPAC-97001 , KIAS-P97001 | hep-ph | null | We calculate the finite temperature self-energy for neutrinos in the presence
of a constant magnetic field in a medium in the unbroken $SU(2) \otimes U(1)$
model. We obtain the exact dispersion relation for such neutrinos and find that
the thermal effective mass is modified by the magnetic field. We also find a
simple analytic expression for the dispersion relation and obtain the index of
refraction for large neutrino momentum.
| [
{
"created": "Thu, 16 Jan 1997 22:43:17 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Erdas",
"A.",
""
],
[
"Kim",
"C. W.",
""
],
[
"Lee",
"T. H.",
""
]
] | We calculate the finite temperature self-energy for neutrinos in the presence of a constant magnetic field in a medium in the unbroken $SU(2) \otimes U(1)$ model. We obtain the exact dispersion relation for such neutrinos and find that the thermal effective mass is modified by the magnetic field. We also find a simple analytic expression for the dispersion relation and obtain the index of refraction for large neutrino momentum. |
hep-ph/0312189 | Michele Caffo | M. Caffo, H. Czyz, A. Grzelinska and E. Remiddi | Numerical evaluation of the general massive 2-loop 4-denominator
self-mass master integral from differential equations | Latex, 20 pages, 7 figures | Nucl.Phys. B681 (2004) 230-246 | 10.1016/j.nuclphysb.2004.01.019 | null | hep-ph | null | The differential equation in the external invariant p^2 satisfied by the
master integral of the general massive 2-loop 4-denominator self-mass diagram
is exploited and the expansion of the master integral at p^2=0 is obtained
analytically. The system composed by this differential equation with those of
the master integrals related to the general massive 2-loop sunrise diagram is
numerically solved by the Runge-Kutta method in the complex p^2 plane. A
numerical method to obtain results for values of p^2 at and close to thresholds
and pseudo-thresholds is discussed in details.
| [
{
"created": "Mon, 15 Dec 2003 18:26:29 GMT",
"version": "v1"
}
] | 2010-04-05 | [
[
"Caffo",
"M.",
""
],
[
"Czyz",
"H.",
""
],
[
"Grzelinska",
"A.",
""
],
[
"Remiddi",
"E.",
""
]
] | The differential equation in the external invariant p^2 satisfied by the master integral of the general massive 2-loop 4-denominator self-mass diagram is exploited and the expansion of the master integral at p^2=0 is obtained analytically. The system composed by this differential equation with those of the master integrals related to the general massive 2-loop sunrise diagram is numerically solved by the Runge-Kutta method in the complex p^2 plane. A numerical method to obtain results for values of p^2 at and close to thresholds and pseudo-thresholds is discussed in details. |
hep-ph/0111242 | Jean-Marc Virey | P. Taxil, E. Tugcu and J.-M. Virey | Constraints on leptophobic gauge bosons with polarized neutrons and
protons at RHIC | Latex file, 19 pages and 4 ps fig included | Eur.Phys.J.C24:149-157,2002 | 10.1007/s100520200900 | CPT-01/P.4263 | hep-ph | null | We explore the sensitivity and the physics interest of the measurement of
parity-violating spin asymmetries in one-jet production in the presence of a
new leptophobic neutral gauge boson Z', within polarized hadronic collisions at
the BNL RHIC. We focus on polarized neutron collisions which could be achieved
in a realistic upgrade of the RHIC-Spin program. We show that, in case of a
discovery, a compilation of the information coming from both polarized pp and
nn collisions should constrain the number of Higgs doublets and the presence or
absence of trilinear fermion mass terms in the underlying model of New Physics.
| [
{
"created": "Tue, 20 Nov 2001 12:05:40 GMT",
"version": "v1"
}
] | 2011-09-13 | [
[
"Taxil",
"P.",
""
],
[
"Tugcu",
"E.",
""
],
[
"Virey",
"J. -M.",
""
]
] | We explore the sensitivity and the physics interest of the measurement of parity-violating spin asymmetries in one-jet production in the presence of a new leptophobic neutral gauge boson Z', within polarized hadronic collisions at the BNL RHIC. We focus on polarized neutron collisions which could be achieved in a realistic upgrade of the RHIC-Spin program. We show that, in case of a discovery, a compilation of the information coming from both polarized pp and nn collisions should constrain the number of Higgs doublets and the presence or absence of trilinear fermion mass terms in the underlying model of New Physics. |
hep-ph/0610246 | Joaquim Prades | Elvira Gamiz, Matthias Jamin, Antonio Pich, Joaquim Prades and Felix
Schwab | |V_us| from Strange Hadronic Tau Data | 7 pages, no figures. Invited talk given by J.P. at ICHEP'06, 26 July
to 2 August, Moscow, Russia | null | 10.1142/9789812790873_0161 | CERN-PH-TH/2006-204; UAB-FT-614 | hep-ph hep-ex | null | We report on recent work to determine the CKM matrix element |V_{us}| using
strange hadronic \tau decay data. We use the recent OPAL update of the strange
spectral function, while on the theory side we update the dimension-two
perturbative contribution including the recently calculated \alpha_s^3 terms.
Our result |V_{us}|=0.2220 \pm 0.0033 is already competitive with the standard
extraction from K_{e3} decays and other new proposals to determine |V_{us}|.
The actual uncertainty on |V_{us}| from \tau data is dominated largely by
experiment and will eventually be much reduced by B-factories and future
\tau-charm factory data, providing one of the most accurate determinations of
this Standard Model parameter.
| [
{
"created": "Thu, 19 Oct 2006 10:24:03 GMT",
"version": "v1"
}
] | 2017-08-23 | [
[
"Gamiz",
"Elvira",
""
],
[
"Jamin",
"Matthias",
""
],
[
"Pich",
"Antonio",
""
],
[
"Prades",
"Joaquim",
""
],
[
"Schwab",
"Felix",
""
]
] | We report on recent work to determine the CKM matrix element |V_{us}| using strange hadronic \tau decay data. We use the recent OPAL update of the strange spectral function, while on the theory side we update the dimension-two perturbative contribution including the recently calculated \alpha_s^3 terms. Our result |V_{us}|=0.2220 \pm 0.0033 is already competitive with the standard extraction from K_{e3} decays and other new proposals to determine |V_{us}|. The actual uncertainty on |V_{us}| from \tau data is dominated largely by experiment and will eventually be much reduced by B-factories and future \tau-charm factory data, providing one of the most accurate determinations of this Standard Model parameter. |
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