id stringlengths 9 14 | submitter stringlengths 1 56 ⌀ | authors stringlengths 5 7.68k | title stringlengths 3 299 | comments stringlengths 1 1.15k ⌀ | journal-ref stringlengths 9 298 ⌀ | doi stringlengths 12 97 ⌀ | report-no stringlengths 3 341 ⌀ | categories stringclasses 869 values | license stringclasses 9 values | orig_abstract stringlengths 16 2.44k | versions listlengths 1 39 | update_date stringlengths 10 10 | authors_parsed listlengths 1 565 | abstract stringlengths 13 2.44k |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
hep-ph/0608001 | Jean-Marc Richard | Franco Buccella, Hallstein Hogaasen, Jean-Marc Richard, Paul Sorba | Chromomagnetism, flavour symmetry breaking and S-wave tetraquarks | 16 pages, 2 figures, RevTeX, Refs. updated, further typos corrected,
to appear in EPJC | Eur.Phys.J.C49:743-754,2007 | 10.1140/epjc/s10052-006-0142-1 | DSF/13(2006), LAPTH-1150/06,LPSC-06-37 | hep-ph | null | The chromomagnetic interaction, with full account for flavour-symmetry
breaking, is applied to S-wave configurations containing two quarks and two
antiquarks. Phenomenological implications are discussed for light, charmed,
charmed and strange, hidden-charm and double-charm mesons, and extended to
their analogues with beauty.
| [
{
"created": "Tue, 1 Aug 2006 07:51:33 GMT",
"version": "v1"
},
{
"created": "Mon, 7 Aug 2006 05:35:53 GMT",
"version": "v2"
},
{
"created": "Tue, 10 Oct 2006 10:36:53 GMT",
"version": "v3"
},
{
"created": "Sat, 20 Jan 2007 08:00:10 GMT",
"version": "v4"
}
] | 2008-11-26 | [
[
"Buccella",
"Franco",
""
],
[
"Hogaasen",
"Hallstein",
""
],
[
"Richard",
"Jean-Marc",
""
],
[
"Sorba",
"Paul",
""
]
] | The chromomagnetic interaction, with full account for flavour-symmetry breaking, is applied to S-wave configurations containing two quarks and two antiquarks. Phenomenological implications are discussed for light, charmed, charmed and strange, hidden-charm and double-charm mesons, and extended to their analogues with beauty. |
hep-ph/9909237 | Spencer Klein | Spencer R. Klein and Joakim Nystrand | Interference in Exclusive Vector Meson Production in Heavy Ion
Collisions | 13 pages with 3 figures; submitted to Physical Review Letters | Phys.Rev.Lett.84:2330-2333,2000 | 10.1103/PhysRevLett.84.2330 | LBNL-PUB-43907 | hep-ph nucl-th quant-ph | null | Photons emitted from the electromagnetic fields of relativistic heavy ions
can fluctuate into quark anti-quark pairs and scatter from a target nucleus,
emerging as vector mesons. These coherent interactions are identifiable by
final states consisting of the two nuclei and a vector meson with a small
transverse momentum. The emitters and targets can switch roles, and the two
possibilities are indistinguishable, so interference may occur. Vector mesons
are negative parity so the amplitudes have opposite signs. When the meson
transverse wavelength is larger than the impact parameter, the interference is
large and destructive.
The short-lived vector mesons decay before amplitudes from the two sources
can overlap, and so cannot interfere directly. However, the decay products are
emitted in an entangled state, and the interference depends on observing the
complete final state. The non-local wave function is an example of the
Einstein-Podolsky-Rosen paradox.
| [
{
"created": "Fri, 3 Sep 1999 01:42:38 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"Klein",
"Spencer R.",
""
],
[
"Nystrand",
"Joakim",
""
]
] | Photons emitted from the electromagnetic fields of relativistic heavy ions can fluctuate into quark anti-quark pairs and scatter from a target nucleus, emerging as vector mesons. These coherent interactions are identifiable by final states consisting of the two nuclei and a vector meson with a small transverse momentum. The emitters and targets can switch roles, and the two possibilities are indistinguishable, so interference may occur. Vector mesons are negative parity so the amplitudes have opposite signs. When the meson transverse wavelength is larger than the impact parameter, the interference is large and destructive. The short-lived vector mesons decay before amplitudes from the two sources can overlap, and so cannot interfere directly. However, the decay products are emitted in an entangled state, and the interference depends on observing the complete final state. The non-local wave function is an example of the Einstein-Podolsky-Rosen paradox. |
2405.18990 | Sarah Alanazi | A.G. Akeroyd, S. Alanazi and S. Moretti | The Process $gg\to h^0 Z^{*}$ in the Inverted Hierarchy Scenario of the
2HDM Type-I at the LHC | 19 pages, 7 figures. arXiv admin note: text overlap with
arXiv:2301.00728 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | While searching at the Large Hadron Collider (LHC) for the production and
decay of the CP-odd scalar ($A^0$) in the 2-Higgs-Doublet Model (2HDM) with
Natural Flavour Conservation (NFC) via the channels $gg\to A^0$ (through
one-loop triangle diagrams) and $A^0\to h^0 Z^*$ (with $m_{h^0} =125$ GeV or
$m_{h^0} < 125$ GeV, with $Z$ off-shell), respectively, a factorisation of the
two processes is normally performed, with the $A^0$ state being on-shell. While
this approach is gauge-invariant, it is not capturing the presence of either of
the following two channels: $gg\to Z^*\to h^0Z^*$ (through one-loop triangle
diagrams) or $gg\to h^0Z^*$ (through one-loop box diagrams). As the resolution
of the $A^0$ mass cannot be infinitely precise, we affirm that all such
contributions should be computed simultaneously, whichever the $h^0$($Z^{*}$)
decay(splitting) products, thereby including all possible interferences amongst
themselves. The cross section of the ensuing complete process is significantly
different from that obtained in the factorisation case, being of the order up
to ten percent in either direction at the integrated level and larger
(including changes in the shape of kinematical observables) at the differential
level. We thus suggest that the complete calculation ought to be performed
while searching for $A^0$ in this channel. We illustrate this need for the case
of a 2HDM of Type-I in the inverted hierarchy scenario with $m_{h^0}<125$ GeV.
| [
{
"created": "Wed, 29 May 2024 11:10:06 GMT",
"version": "v1"
}
] | 2024-05-30 | [
[
"Akeroyd",
"A. G.",
""
],
[
"Alanazi",
"S.",
""
],
[
"Moretti",
"S.",
""
]
] | While searching at the Large Hadron Collider (LHC) for the production and decay of the CP-odd scalar ($A^0$) in the 2-Higgs-Doublet Model (2HDM) with Natural Flavour Conservation (NFC) via the channels $gg\to A^0$ (through one-loop triangle diagrams) and $A^0\to h^0 Z^*$ (with $m_{h^0} =125$ GeV or $m_{h^0} < 125$ GeV, with $Z$ off-shell), respectively, a factorisation of the two processes is normally performed, with the $A^0$ state being on-shell. While this approach is gauge-invariant, it is not capturing the presence of either of the following two channels: $gg\to Z^*\to h^0Z^*$ (through one-loop triangle diagrams) or $gg\to h^0Z^*$ (through one-loop box diagrams). As the resolution of the $A^0$ mass cannot be infinitely precise, we affirm that all such contributions should be computed simultaneously, whichever the $h^0$($Z^{*}$) decay(splitting) products, thereby including all possible interferences amongst themselves. The cross section of the ensuing complete process is significantly different from that obtained in the factorisation case, being of the order up to ten percent in either direction at the integrated level and larger (including changes in the shape of kinematical observables) at the differential level. We thus suggest that the complete calculation ought to be performed while searching for $A^0$ in this channel. We illustrate this need for the case of a 2HDM of Type-I in the inverted hierarchy scenario with $m_{h^0}<125$ GeV. |
2406.03540 | Marc Riembau | Timothy Cohen, Marc Riembau | Recursion for Wilson-line Form Factors | 28 pages + appendix | null | null | CERN-TH-2024-069 | hep-ph hep-th | http://creativecommons.org/licenses/by/4.0/ | Matrix elements of Wilson-line dressed operators play a central role in the
factorization of soft and collinear modes in gauge theories. When expressed
using spinor helicity variables, these so-called form factors admit a
classification starting from a Maximally Helicity Violating configuration, in
close analogy with gauge theory amplitudes. We show that a single-line complex
momentum shift can be used to derive recursion relations that efficiently
compute these helicity form factors at tree-level: a combination of lower point
form factors and on-shell amplitudes serve as the input building blocks. We
obtain novel compact expressions for the $1\to 2$ and $1\to 3$ splitting
functions in QCD, which also serves to validate our methods.
| [
{
"created": "Wed, 5 Jun 2024 18:00:03 GMT",
"version": "v1"
}
] | 2024-06-07 | [
[
"Cohen",
"Timothy",
""
],
[
"Riembau",
"Marc",
""
]
] | Matrix elements of Wilson-line dressed operators play a central role in the factorization of soft and collinear modes in gauge theories. When expressed using spinor helicity variables, these so-called form factors admit a classification starting from a Maximally Helicity Violating configuration, in close analogy with gauge theory amplitudes. We show that a single-line complex momentum shift can be used to derive recursion relations that efficiently compute these helicity form factors at tree-level: a combination of lower point form factors and on-shell amplitudes serve as the input building blocks. We obtain novel compact expressions for the $1\to 2$ and $1\to 3$ splitting functions in QCD, which also serves to validate our methods. |
hep-ph/0106260 | Yuji Koike | Yuji Koike (Niigata Univ.) | Single-spin asymmetries and soft-gluon poles | Talk presented at the conference DIS2001 held at Bologna, Italy from
April 27 to May 1, 2001. 4 pages with 2 figures in Latex | null | 10.1142/9789812778345_0090 | null | hep-ph | null | Mechanism for the single transverse spin asymmeties in the pion production,
p^\uparrow + p'\to \pi(\ell_T) + X, and the \Lambda hyperon polarization, p +
p' \to \Lambda^\uparrow (\ell_T)+ X, is investigated in the framework of QCD
factorization theorem. We identify all the soft-gluon pole contributions coming
from the twist-3 distribution and/or fragmentation functions and show that they
give rise to large asymmetries at large x_F.
| [
{
"created": "Sat, 23 Jun 2001 04:27:47 GMT",
"version": "v1"
}
] | 2015-06-25 | [
[
"Koike",
"Yuji",
"",
"Niigata Univ."
]
] | Mechanism for the single transverse spin asymmeties in the pion production, p^\uparrow + p'\to \pi(\ell_T) + X, and the \Lambda hyperon polarization, p + p' \to \Lambda^\uparrow (\ell_T)+ X, is investigated in the framework of QCD factorization theorem. We identify all the soft-gluon pole contributions coming from the twist-3 distribution and/or fragmentation functions and show that they give rise to large asymmetries at large x_F. |
hep-ph/9709427 | Giovanni Ridolfi | G. Ridolfi (INFN Genoa, Italy) | Heavy quark production: recent developments | 5 pages Latex, uses epsfig.sty,aipproc.sty, 7 eps figures included.
Talk given at the 5th International Workshop on Deep Inelastic Scattering and
QCD (DIS 97), Chicago, IL, 14-18 Apr 1997 | null | 10.1063/1.53736 | null | hep-ph | null | I discuss some aspects of the comparison between QCD predictions and
experimental data in charm and bottom production.
| [
{
"created": "Tue, 23 Sep 1997 12:22:20 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Ridolfi",
"G.",
"",
"INFN Genoa, Italy"
]
] | I discuss some aspects of the comparison between QCD predictions and experimental data in charm and bottom production. |
2009.01917 | Ahmad Hoseinpour | Hassan Manshouri, Ahmad Hoseinpour and Moslem Zarei | Quantum Boltzmann equation for fermions: An attempt to calculate the NMR
relaxation and decoherence times using quantum field theory techniques | 20 pages, 5 figures | Phys. Rev. D 103, 096020 (2021) | 10.1103/PhysRevD.103.096020 | null | hep-ph cond-mat.quant-gas quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Extracting macroscopic properties of a system from microscopic interactions
has always been an interesting topic with the most diverse applications. Here,
we use the quantum Boltzmann equation to investigate the density matrix
evolution of a system of nucleons. Using the quantum field theory tools for
constructing the density matrix operators and calculating the interactions is
the main advantage of this equation. The right-hand side of this equation
involves forward scattering and usual collision terms. As examples of
application, we calculate the standard Bloch equations for the nucleon system
in the presence of a constant and an oscillating magnetic field from the
forward scattering term. We find the longitudinal and transverse (decoherence)
relaxation times from the collision term by considering the nucleon-nucleon
scattering.
| [
{
"created": "Thu, 3 Sep 2020 20:41:49 GMT",
"version": "v1"
},
{
"created": "Tue, 22 Sep 2020 18:07:08 GMT",
"version": "v2"
},
{
"created": "Sat, 12 Jun 2021 07:19:13 GMT",
"version": "v3"
}
] | 2021-06-15 | [
[
"Manshouri",
"Hassan",
""
],
[
"Hoseinpour",
"Ahmad",
""
],
[
"Zarei",
"Moslem",
""
]
] | Extracting macroscopic properties of a system from microscopic interactions has always been an interesting topic with the most diverse applications. Here, we use the quantum Boltzmann equation to investigate the density matrix evolution of a system of nucleons. Using the quantum field theory tools for constructing the density matrix operators and calculating the interactions is the main advantage of this equation. The right-hand side of this equation involves forward scattering and usual collision terms. As examples of application, we calculate the standard Bloch equations for the nucleon system in the presence of a constant and an oscillating magnetic field from the forward scattering term. We find the longitudinal and transverse (decoherence) relaxation times from the collision term by considering the nucleon-nucleon scattering. |
hep-ph/9412204 | Vadim Zeitlin | Vadim Zeitlin (P.N.Lebedev Physical Institute) | Low-Temperature QED with External Magnetic Field | 9 pages, LaTeX | null | null | FIAN/TD/94-10 | hep-ph cond-mat | null | Low-temperature expansion of the effective Lagrangian of the QED$_{3+1}$ with
a uniform magnetic field and a finite chemical potential is performed.
Temperature corrections, as well as zero-temperature expression for the
effective Lagrangian are presented as finite sums over partially filled Landau
levels.
| [
{
"created": "Thu, 1 Dec 1994 12:41:05 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Zeitlin",
"Vadim",
"",
"P.N.Lebedev Physical Institute"
]
] | Low-temperature expansion of the effective Lagrangian of the QED$_{3+1}$ with a uniform magnetic field and a finite chemical potential is performed. Temperature corrections, as well as zero-temperature expression for the effective Lagrangian are presented as finite sums over partially filled Landau levels. |
0712.3193 | Ivanov Dmitry | D.Yu. Ivanov | Exclusive vector meson electroproduction | 7 pages; Talk given at 12th International Conference on Elastic and
Diffractive Scattering: Forward Physics and QCD, Hamburg, DESY, Germany,
21-25 May 2007 | null | null | null | hep-ph | null | We discuss exclusive vector meson electroproduction within the QCD collinear
factorization framework. In Bjorken kinematics the amplitude factorizes in a
convolution of the nonperturbative meson distribution amplitude and the
generalized parton densities with the perturbatively calculable hard-scattering
amplitudes, which are presently known to next-to-leading order (NLO). At small
$x_{\rm B}$ NLO corrections are very large. It is related to appearance of BFKL
type logarithms in the hard-scattering amplitudes, that calls for a resummation
of these effects at higher orders. Here we report the first results of such
resummation.
| [
{
"created": "Wed, 19 Dec 2007 14:29:32 GMT",
"version": "v1"
}
] | 2007-12-20 | [
[
"Ivanov",
"D. Yu.",
""
]
] | We discuss exclusive vector meson electroproduction within the QCD collinear factorization framework. In Bjorken kinematics the amplitude factorizes in a convolution of the nonperturbative meson distribution amplitude and the generalized parton densities with the perturbatively calculable hard-scattering amplitudes, which are presently known to next-to-leading order (NLO). At small $x_{\rm B}$ NLO corrections are very large. It is related to appearance of BFKL type logarithms in the hard-scattering amplitudes, that calls for a resummation of these effects at higher orders. Here we report the first results of such resummation. |
2311.02149 | Xucheng Gan | Xucheng Gan, Lian-Tao Wang, Huangyu Xiao | Detecting Axion Dark Matter with Black Hole Polarimetry | 13 pages, 4 appendices, 3 figures | null | null | FERMILAB-PUB-23-635-T | hep-ph astro-ph.CO astro-ph.GA astro-ph.HE | http://creativecommons.org/licenses/by/4.0/ | The axion, as a leading dark matter candidate, is the target of many on-going
and proposed experimental searches based on its coupling to photons. Ultralight
axions that couple to photons can also cause polarization rotation of light
which can be probed by cosmic microwave background. In this work, we show that
a large axion field is inevitably developed around black holes due to the
Bose-Einstein condensation of axions, enhancing the induced birefringence
effects. Therefore, we propose measuring the modulation of supermassive black
hole imaging polarization angles as a new probe to the axion-photon coupling of
axion dark matter. The oscillating axion field around black holes induces
polarization rotation on the black hole image, which is detectable and
distinguishable from astrophysical effects on the polarization angle, as it
exhibits distinctive temporal variability and frequency invariability. We
present the range of axion-photon couplings within the axion mass range
$10^{-21}-10^{-16}\text{eV}$ that can be probed by the Event Horizon Telescope.
The axion parameter space probed by black hole polarimetry will expand with the
improvement in sensitivity on the polarization measurement and more black hole
polarimetry targets with determined black hole masses.
| [
{
"created": "Fri, 3 Nov 2023 18:00:00 GMT",
"version": "v1"
}
] | 2023-11-07 | [
[
"Gan",
"Xucheng",
""
],
[
"Wang",
"Lian-Tao",
""
],
[
"Xiao",
"Huangyu",
""
]
] | The axion, as a leading dark matter candidate, is the target of many on-going and proposed experimental searches based on its coupling to photons. Ultralight axions that couple to photons can also cause polarization rotation of light which can be probed by cosmic microwave background. In this work, we show that a large axion field is inevitably developed around black holes due to the Bose-Einstein condensation of axions, enhancing the induced birefringence effects. Therefore, we propose measuring the modulation of supermassive black hole imaging polarization angles as a new probe to the axion-photon coupling of axion dark matter. The oscillating axion field around black holes induces polarization rotation on the black hole image, which is detectable and distinguishable from astrophysical effects on the polarization angle, as it exhibits distinctive temporal variability and frequency invariability. We present the range of axion-photon couplings within the axion mass range $10^{-21}-10^{-16}\text{eV}$ that can be probed by the Event Horizon Telescope. The axion parameter space probed by black hole polarimetry will expand with the improvement in sensitivity on the polarization measurement and more black hole polarimetry targets with determined black hole masses. |
hep-ph/0408193 | Adriano Gomes doff | A. Doff and A. A. Natale | A dynamical mechanism to explain the top-bottom quark mass hierarchy | Changes are made in sections I, II and IV; an new figure added;
results unchanged; accepted for publication in Int. J. Mod. Phys. A | Int.J.Mod.Phys.A20:7567-7578,2005 | 10.1142/S0217751X05021269 | null | hep-ph | null | We discuss the mass splitting between the the top and bottom quarks in a
technicolor scenario. The model proposed here contains a left-right electroweak
gauge group. An extended technicolor group and mirror fermions are introduced.
The top-bottom quark mass splitting turns out to be intimately connected to the
breaking of the left-right gauge symmetry. Weak isospin violation occurs within
the experimental limits.
| [
{
"created": "Tue, 17 Aug 2004 19:09:36 GMT",
"version": "v1"
},
{
"created": "Wed, 18 Aug 2004 18:20:49 GMT",
"version": "v2"
},
{
"created": "Tue, 21 Sep 2004 02:48:38 GMT",
"version": "v3"
},
{
"created": "Thu, 20 Jan 2005 12:13:54 GMT",
"version": "v4"
}
] | 2011-01-27 | [
[
"Doff",
"A.",
""
],
[
"Natale",
"A. A.",
""
]
] | We discuss the mass splitting between the the top and bottom quarks in a technicolor scenario. The model proposed here contains a left-right electroweak gauge group. An extended technicolor group and mirror fermions are introduced. The top-bottom quark mass splitting turns out to be intimately connected to the breaking of the left-right gauge symmetry. Weak isospin violation occurs within the experimental limits. |
2305.02682 | Luca Paolo Wiggering | Luca Paolo Wiggering | Radiative corrections to stop-antistop annihilation | 4 pages, 3 figures, contribution to the 2023 Electroweak session of
the 57th Rencontres de Moriond | null | null | MS-TP-23-17 | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We compute the full $\mathcal{O}(\alpha_s)$ corrections to stop-antistop
annihilation into two gluons and a light quark-antiquark pair within the
framework of the Minimal Supersymmetric Standard Model (MSSM), including the
non-perturbative Sommerfeld enhancement effect. Numerical results for the total
annihilation cross section are shown and the effect on the neutralino relic
density is discussed for an example scenario in the phenomenological MSSM.
| [
{
"created": "Thu, 4 May 2023 09:53:48 GMT",
"version": "v1"
}
] | 2023-05-05 | [
[
"Wiggering",
"Luca Paolo",
""
]
] | We compute the full $\mathcal{O}(\alpha_s)$ corrections to stop-antistop annihilation into two gluons and a light quark-antiquark pair within the framework of the Minimal Supersymmetric Standard Model (MSSM), including the non-perturbative Sommerfeld enhancement effect. Numerical results for the total annihilation cross section are shown and the effect on the neutralino relic density is discussed for an example scenario in the phenomenological MSSM. |
2102.05124 | Taegyun Kim | Taegyun Kim and Adam Martin | A $W^\pm$ polarization analyzer from Deep Neural Networks | null | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper, we train a Convolutional Neural Network to classify
longitudinally and transversely polarized hadronic $W^\pm$ using the images of
boosted $W^{\pm}$ jets as input. The images capture angular and energy
information from the jet constituents that is faithful to properties of the
original quark/anti-quark $W^{\pm}$ decay products without the need for
invasive substructure cuts. We find that the difference between the
polarizations is too subtle for the network to be used as an event-by-event
tagger. However, given an ensemble of $W^{\pm}$ events with unknown
polarization, the average network output from that ensemble can be used to
extract the longitudinal fraction $f_L$. We test the network on Standard Model
$pp \to W^{\pm}Z$ events and on $pp \to W^{\pm}Z$ in the presence of
dimension-6 operators that perturb the polarization composition.
| [
{
"created": "Tue, 9 Feb 2021 20:49:13 GMT",
"version": "v1"
}
] | 2021-02-11 | [
[
"Kim",
"Taegyun",
""
],
[
"Martin",
"Adam",
""
]
] | In this paper, we train a Convolutional Neural Network to classify longitudinally and transversely polarized hadronic $W^\pm$ using the images of boosted $W^{\pm}$ jets as input. The images capture angular and energy information from the jet constituents that is faithful to properties of the original quark/anti-quark $W^{\pm}$ decay products without the need for invasive substructure cuts. We find that the difference between the polarizations is too subtle for the network to be used as an event-by-event tagger. However, given an ensemble of $W^{\pm}$ events with unknown polarization, the average network output from that ensemble can be used to extract the longitudinal fraction $f_L$. We test the network on Standard Model $pp \to W^{\pm}Z$ events and on $pp \to W^{\pm}Z$ in the presence of dimension-6 operators that perturb the polarization composition. |
1801.10244 | Takahiro Morishima | Takahiro Morishima, Toshifumi Futamase, Hirohiko M. Shimizu | The general relativistic effects to the magnetic moment in the Earth's
gravity | This is a revised version of arXiv:1801.10244. Our three submitted
papers of series (arXiv:1801.10244, arXiv:1801.10245, arXiv:1801.10246) are
combined into a single paper | Prog. Theor. Exp. Phys. 063B07 (2018) | 10.1093/ptep/pty066 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The magnetic moment of free fermions in the Earth's gravitational field has
been studied on the basis of the general relativity. Adopting the Schwarzschild
metric for the background spacetime, the dipole coupling between the magnetic
moment and the magnetic field has been found to be dependent of the gravity in
the calculation up to the post-Newtonian order $O(1/c^2)$. The
gravity-dependence can be formulated by employing the effective value of the
magnetic moment as a gravity-dependent quantity ${\mu}_{\rm m}^{\rm eff}=
(1+3\phi/c^2) \,\,{\mu}_{\rm m} $ commonly for the cases of minimal coupling,
non-minimal coupling and their mixture. The gravitationally induced anomaly is
found to be canceled in the experimental values of the anomalous magnetic
moment measured in the Penning trap and storage ring methods.
| [
{
"created": "Tue, 30 Jan 2018 22:29:34 GMT",
"version": "v1"
},
{
"created": "Tue, 27 Mar 2018 09:28:04 GMT",
"version": "v2"
},
{
"created": "Thu, 17 May 2018 05:47:12 GMT",
"version": "v3"
}
] | 2018-07-02 | [
[
"Morishima",
"Takahiro",
""
],
[
"Futamase",
"Toshifumi",
""
],
[
"Shimizu",
"Hirohiko M.",
""
]
] | The magnetic moment of free fermions in the Earth's gravitational field has been studied on the basis of the general relativity. Adopting the Schwarzschild metric for the background spacetime, the dipole coupling between the magnetic moment and the magnetic field has been found to be dependent of the gravity in the calculation up to the post-Newtonian order $O(1/c^2)$. The gravity-dependence can be formulated by employing the effective value of the magnetic moment as a gravity-dependent quantity ${\mu}_{\rm m}^{\rm eff}= (1+3\phi/c^2) \,\,{\mu}_{\rm m} $ commonly for the cases of minimal coupling, non-minimal coupling and their mixture. The gravitationally induced anomaly is found to be canceled in the experimental values of the anomalous magnetic moment measured in the Penning trap and storage ring methods. |
2308.14438 | Peiwen Wu | Chengcheng Han, Peiwen Wu, Jin Min Yang, Mengchao Zhang | Freeze-in bino dark matter in high scale supersymmetry | 23 pages, 4 figures, revised version accepted by Physical Review D
for publication | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We explore a scenario of high scale supersymmetry where all supersymmetric
particles except gauginos stay at a high energy scale $M_{\rm SUSY}$ which is
much larger than the reheating temperature $T_\text{RH}$. The dark matter is
dominated by bino component with mass around the electroweak scale and the
observed relic abundance is mainly generated by the freeze-in process during
the early universe. Considering the various constraints, we identify two
available scenarios in which the supersymmetric sector at an energy scale below
$T_\text{RH}$ consists of: a) bino; b) bino and wino. Typically, for a bino
mass around 0.1-1 TeV and a wino mass around 2 TeV, we find that $M_{\rm SUSY}$
should be around $10^{12-14}$ GeV with $T_\text{RH}$ around $10^{4-6}$ GeV.
| [
{
"created": "Mon, 28 Aug 2023 09:24:11 GMT",
"version": "v1"
},
{
"created": "Fri, 8 Dec 2023 08:36:15 GMT",
"version": "v2"
}
] | 2023-12-11 | [
[
"Han",
"Chengcheng",
""
],
[
"Wu",
"Peiwen",
""
],
[
"Yang",
"Jin Min",
""
],
[
"Zhang",
"Mengchao",
""
]
] | We explore a scenario of high scale supersymmetry where all supersymmetric particles except gauginos stay at a high energy scale $M_{\rm SUSY}$ which is much larger than the reheating temperature $T_\text{RH}$. The dark matter is dominated by bino component with mass around the electroweak scale and the observed relic abundance is mainly generated by the freeze-in process during the early universe. Considering the various constraints, we identify two available scenarios in which the supersymmetric sector at an energy scale below $T_\text{RH}$ consists of: a) bino; b) bino and wino. Typically, for a bino mass around 0.1-1 TeV and a wino mass around 2 TeV, we find that $M_{\rm SUSY}$ should be around $10^{12-14}$ GeV with $T_\text{RH}$ around $10^{4-6}$ GeV. |
2212.06491 | Steven Cotterill | R. A. Battye, S. J. Cotterill | Pinching instabilities in superconducting strings | 14 pages, 7 figures | null | 10.1103/PhysRevD.107.063534 | null | hep-ph astro-ph.CO hep-th | http://creativecommons.org/licenses/by/4.0/ | Superconducting cosmic strings can exhibit longitudinal, pinching
instabilities in some regions of the parameter space. We make predictions about
the onset of this instability using the thin string approximation (TSA) and
develop an improved analysis that remains applicable for small wavelength
perturbations, where the TSA breaks down. We use simulations of perturbed
strings to assess the accuracy of the TSA, test the predictions of our new
analysis and demonstrate an improvement over previous methods in the
literature. Notably, it appears that the instabilities are typically present
for a larger range of magnetic strings than previously expected, and we show
examples of pinching instabilities also occurring in electric strings. However,
both our simulations and predictions agree that strings near the chiral limit
are free from pinching instabilities and in particular our results support our
previously published claim that vortons can be stable to all classical
perturbations if they are sufficiently large.
| [
{
"created": "Tue, 13 Dec 2022 11:17:02 GMT",
"version": "v1"
}
] | 2023-03-29 | [
[
"Battye",
"R. A.",
""
],
[
"Cotterill",
"S. J.",
""
]
] | Superconducting cosmic strings can exhibit longitudinal, pinching instabilities in some regions of the parameter space. We make predictions about the onset of this instability using the thin string approximation (TSA) and develop an improved analysis that remains applicable for small wavelength perturbations, where the TSA breaks down. We use simulations of perturbed strings to assess the accuracy of the TSA, test the predictions of our new analysis and demonstrate an improvement over previous methods in the literature. Notably, it appears that the instabilities are typically present for a larger range of magnetic strings than previously expected, and we show examples of pinching instabilities also occurring in electric strings. However, both our simulations and predictions agree that strings near the chiral limit are free from pinching instabilities and in particular our results support our previously published claim that vortons can be stable to all classical perturbations if they are sufficiently large. |
0911.2242 | Rabindra N. Mohapatra | Bhaskar Dutta, Yukihiro Mimura and R.N. Mohapatra | An SO(10) Grand Unified Theory of Flavor | Final version of the paper as it will appear in JHEP. | JHEP 1005:034,2010 | 10.1007/JHEP05(2010)034 | MIFP-09-45, UMD-PP-09-059 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a supersymmetric SO(10) grand unified theory (GUT) of flavor based
on an $S_4$ family symmetry. It makes use of our recent proposal to use SO(10)
with type II seesaw mechanism for neutrino masses combined with a simple ansatz
that the dominant Yukawa matrix (the {\bf 10}-Higgs coupling to matter) has
rank one. In this paper, we show how the rank one model can arise within some
plausible assumptions as an effective field theory from vectorlike {\bf 16}
dimensional matter fields with masses above the GUT scale. In order to obtain
the desired fermion flavor texture we use $S_4$ flavon multiplets which acquire
vevs in the ground state of the theory. By supplementing the $S_4$ theory with
an additional discrete symmetry, we find that the flavon vacuum field
alignments take a discrete set of values provided some of the higher
dimensional couplings are small. Choosing a particular set of these vacuum
alignments appears to lead to an unified understanding of observed quark-lepton
flavor:
(i) the lepton mixing matrix that is dominantly tri-bi-maximal with small
corrections related to quark mixings; (ii) quark lepton mass relations at GUT
scale: $m_b\simeq m_{\tau}$ and $m_\mu\simeq 3 m_s$ and (iii) the solar to
atmospheric neutrino mass ratio $m_\odot/m_{\rm atm}\simeq \theta_{\rm
Cabibbo}$ in agreement with observations. The model predicts the neutrino
mixing parameter, $U_{e3} \simeq \theta_{\rm Cabibbo}/(3\sqrt2) \sim 0.05$,
which should be observable in planned long baseline experiments.
| [
{
"created": "Wed, 11 Nov 2009 21:10:47 GMT",
"version": "v1"
},
{
"created": "Thu, 17 Dec 2009 19:33:19 GMT",
"version": "v2"
},
{
"created": "Sun, 25 Apr 2010 17:52:47 GMT",
"version": "v3"
}
] | 2010-05-28 | [
[
"Dutta",
"Bhaskar",
""
],
[
"Mimura",
"Yukihiro",
""
],
[
"Mohapatra",
"R. N.",
""
]
] | We present a supersymmetric SO(10) grand unified theory (GUT) of flavor based on an $S_4$ family symmetry. It makes use of our recent proposal to use SO(10) with type II seesaw mechanism for neutrino masses combined with a simple ansatz that the dominant Yukawa matrix (the {\bf 10}-Higgs coupling to matter) has rank one. In this paper, we show how the rank one model can arise within some plausible assumptions as an effective field theory from vectorlike {\bf 16} dimensional matter fields with masses above the GUT scale. In order to obtain the desired fermion flavor texture we use $S_4$ flavon multiplets which acquire vevs in the ground state of the theory. By supplementing the $S_4$ theory with an additional discrete symmetry, we find that the flavon vacuum field alignments take a discrete set of values provided some of the higher dimensional couplings are small. Choosing a particular set of these vacuum alignments appears to lead to an unified understanding of observed quark-lepton flavor: (i) the lepton mixing matrix that is dominantly tri-bi-maximal with small corrections related to quark mixings; (ii) quark lepton mass relations at GUT scale: $m_b\simeq m_{\tau}$ and $m_\mu\simeq 3 m_s$ and (iii) the solar to atmospheric neutrino mass ratio $m_\odot/m_{\rm atm}\simeq \theta_{\rm Cabibbo}$ in agreement with observations. The model predicts the neutrino mixing parameter, $U_{e3} \simeq \theta_{\rm Cabibbo}/(3\sqrt2) \sim 0.05$, which should be observable in planned long baseline experiments. |
1506.06128 | Igor M. Suslov | I. M. Suslov (Kapitza Institute for Physical Problems, Moscow, Russia) | A thorny path of field theory: from triviality to interaction and
confinement | Review article, 30 pages, 15 figures. arXiv admin note: substantial
text overlap with arXiv:1102.4534, arXiv:0911.1149 | null | null | null | hep-ph cond-mat.stat-mech hep-lat hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Summation of the perturbation series for the Gell-Mann--Low function \beta(g)
of \phi^4 theory leads to the asymptotics \beta(g)=\beta_\infty g^\alpha at
g\to\infty, where \alpha\approx 1 for space dimensions d=2,3,4. The natural
hypothesis arises, that asymptotic behavior is \beta(g) \sim g for all d.
Consideration of the "toy" zero-dimensional model confirms the hypothesis and
reveals the origin of this result: it is related with a zero of a certain
functional integral. This mechanism remains valid for arbitrary space
dimensionality d. The same result for the asymptotics is obtained for
explicitly accepted lattice regularization, while the use of high-temperature
expansions allows to calculate the whole \beta-function. As a result, the
\beta-function of four-dimensional \phi^4 theory is appeared to be
non-alternating and has a linear asymptotics at infinity. The analogous
situation is valid for QED. According to the Bogoliubov and Shirkov
classification, it means possibility to construct the continuous theory with
finite interaction at large distances. This conclusion is in visible
contradiction with the lattice results indicating triviality of \phi^4 theory.
This contradiction is resolved by a special character of renormalizability in
\phi^4 theory: to obtain the continuous renormalized theory, there is no need
to eliminate a lattice from the bare theory. In fact, such kind of
renormalizability is not accidental and can be understood in the framework of
Wilson's many-parameter renormalization group. Application of these ideas to
QCD shows that Wilson's theory of confinement is not purely illustrative, but
has a direct relation to a real situation. As a result, the problem of
analytical proof of confinement and a mass gap can be considered as solved, at
least on the physical level of rigor.
| [
{
"created": "Thu, 18 Jun 2015 23:59:27 GMT",
"version": "v1"
}
] | 2015-06-24 | [
[
"Suslov",
"I. M.",
"",
"Kapitza Institute for Physical Problems, Moscow, Russia"
]
] | Summation of the perturbation series for the Gell-Mann--Low function \beta(g) of \phi^4 theory leads to the asymptotics \beta(g)=\beta_\infty g^\alpha at g\to\infty, where \alpha\approx 1 for space dimensions d=2,3,4. The natural hypothesis arises, that asymptotic behavior is \beta(g) \sim g for all d. Consideration of the "toy" zero-dimensional model confirms the hypothesis and reveals the origin of this result: it is related with a zero of a certain functional integral. This mechanism remains valid for arbitrary space dimensionality d. The same result for the asymptotics is obtained for explicitly accepted lattice regularization, while the use of high-temperature expansions allows to calculate the whole \beta-function. As a result, the \beta-function of four-dimensional \phi^4 theory is appeared to be non-alternating and has a linear asymptotics at infinity. The analogous situation is valid for QED. According to the Bogoliubov and Shirkov classification, it means possibility to construct the continuous theory with finite interaction at large distances. This conclusion is in visible contradiction with the lattice results indicating triviality of \phi^4 theory. This contradiction is resolved by a special character of renormalizability in \phi^4 theory: to obtain the continuous renormalized theory, there is no need to eliminate a lattice from the bare theory. In fact, such kind of renormalizability is not accidental and can be understood in the framework of Wilson's many-parameter renormalization group. Application of these ideas to QCD shows that Wilson's theory of confinement is not purely illustrative, but has a direct relation to a real situation. As a result, the problem of analytical proof of confinement and a mass gap can be considered as solved, at least on the physical level of rigor. |
hep-ph/9806396 | Javier Magnin | J.C. Anjos, J. Magnin, F.R.A. Simao and J. Solano | Asymmetry studies in Lambda 0/Lambda 0-bar, Xi-/Xi+ and Omega-/Omega+
production | One reference corrected | null | 10.1063/1.56627 | CBPF-NF-045/98 | hep-ph | null | We present a study on hyperon/anti-hyperon production asymmetries in the
framework of the recombination model. The production asymmetries for Lambda
0/Lambda 0-bar, Xi-/Xi+ and Omega-/Omega+ are studied as a function of x_F.
Predictions of the model are compared to preliminary data on
hyperon/anti-hyperon production asymmetries in 500 GeV/c pi- p interactions
from the Fermilab E791 experiment. The model predicts a growing asymmetry with
the number of valence quarks shared by the target and the produced hyperons in
the x_F < 0 region. In the positive x_F region, the model predicts constant
asymmetries for Lambda 0/Lambda 0-bar and Omega-/Omega+ production and a
growing asymmetry with x_F for Xi-/Xi+. We found a qualitatively good agreement
between the model predictions and data, showing that recombination is a
competitive mechanism in the hadronization process.
| [
{
"created": "Wed, 17 Jun 1998 19:31:35 GMT",
"version": "v1"
},
{
"created": "Fri, 19 Jun 1998 12:00:38 GMT",
"version": "v2"
},
{
"created": "Wed, 24 Jun 1998 20:30:54 GMT",
"version": "v3"
}
] | 2009-10-31 | [
[
"Anjos",
"J. C.",
""
],
[
"Magnin",
"J.",
""
],
[
"Simao",
"F. R. A.",
""
],
[
"Solano",
"J.",
""
]
] | We present a study on hyperon/anti-hyperon production asymmetries in the framework of the recombination model. The production asymmetries for Lambda 0/Lambda 0-bar, Xi-/Xi+ and Omega-/Omega+ are studied as a function of x_F. Predictions of the model are compared to preliminary data on hyperon/anti-hyperon production asymmetries in 500 GeV/c pi- p interactions from the Fermilab E791 experiment. The model predicts a growing asymmetry with the number of valence quarks shared by the target and the produced hyperons in the x_F < 0 region. In the positive x_F region, the model predicts constant asymmetries for Lambda 0/Lambda 0-bar and Omega-/Omega+ production and a growing asymmetry with x_F for Xi-/Xi+. We found a qualitatively good agreement between the model predictions and data, showing that recombination is a competitive mechanism in the hadronization process. |
2205.05145 | Andreas Ekstedt | Andreas Ekstedt | Convergence of the nucleation rate for first-order phase transitions | 6 pages, 3 figures | null | 10.1103/PhysRevD.106.095026 | null | hep-ph hep-th | http://creativecommons.org/licenses/by/4.0/ | This paper investigates the importance of radiative corrections for
first-order phase transitions, with particular focus on the bubble-nucleation
rate. All calculations are done with a strict power-counting, and observables
are consistently calculated at every order. This ensures that physical
quantities are gauge and renormalization-scale invariant. Furthermore, to avoid
large logarithms at high-temperatures, an effective three-dimensional theory is
used. This effective theory automatically incorporates higher-order thermal
masses. The results of this paper indicate that sub-leading corrections to the
rate can be large. This is partly because radiative corrections are enhanced
for large bubbles. To illustrate the calculations, three models are considered:
a real-scalar model, a radiative-barrier model, and a model with an effective
dimension $6$ operator. Relevant observables are calculated for each model, and
the reliability of perturbation theory is discussed.
| [
{
"created": "Tue, 10 May 2022 19:55:05 GMT",
"version": "v1"
}
] | 2022-12-07 | [
[
"Ekstedt",
"Andreas",
""
]
] | This paper investigates the importance of radiative corrections for first-order phase transitions, with particular focus on the bubble-nucleation rate. All calculations are done with a strict power-counting, and observables are consistently calculated at every order. This ensures that physical quantities are gauge and renormalization-scale invariant. Furthermore, to avoid large logarithms at high-temperatures, an effective three-dimensional theory is used. This effective theory automatically incorporates higher-order thermal masses. The results of this paper indicate that sub-leading corrections to the rate can be large. This is partly because radiative corrections are enhanced for large bubbles. To illustrate the calculations, three models are considered: a real-scalar model, a radiative-barrier model, and a model with an effective dimension $6$ operator. Relevant observables are calculated for each model, and the reliability of perturbation theory is discussed. |
1501.03604 | Jinn-Ouk Gong | Jinn-Ouk Gong, Shi Pi and Godfrey Leung | Probing reheating with primordial spectrum | (v1) 12 pages, 2 figures; (v2) references added; (v3) typos
corrected, figures improved with Planck 2015 data, to appear in Journal of
Cosmology and Astroparticle Physics | null | 10.1088/1475-7516/2015/05/027 | APCTP-Pre2015-001 | hep-ph astro-ph.CO gr-qc hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the impacts of reheating temperature on the inflationary predictions
of the spectral index and tensor-to-scalar ratio. Assuming sinusoidal
oscillations and that reheating process is very fast, the reheating temperature
can be constrained for sinusoidal oscillation within a factor of 10 - 100 or
even better with the prospect of future observations. Beyond this, we find that
the predictions can also be insensitive to the reheating temperature in certain
models, including Higgs inflation.
| [
{
"created": "Thu, 15 Jan 2015 09:09:19 GMT",
"version": "v1"
},
{
"created": "Thu, 29 Jan 2015 02:16:49 GMT",
"version": "v2"
},
{
"created": "Mon, 11 May 2015 13:39:35 GMT",
"version": "v3"
}
] | 2015-05-27 | [
[
"Gong",
"Jinn-Ouk",
""
],
[
"Pi",
"Shi",
""
],
[
"Leung",
"Godfrey",
""
]
] | We study the impacts of reheating temperature on the inflationary predictions of the spectral index and tensor-to-scalar ratio. Assuming sinusoidal oscillations and that reheating process is very fast, the reheating temperature can be constrained for sinusoidal oscillation within a factor of 10 - 100 or even better with the prospect of future observations. Beyond this, we find that the predictions can also be insensitive to the reheating temperature in certain models, including Higgs inflation. |
2104.03223 | Norimi Yokozaki | Sho Iwamoto, Tsutomu T. Yanagida and Norimi Yokozaki | Wino-Higgsino dark matter in the MSSM from the $g-2$ anomaly | Figures and benchmark point for tanb=40 added, typos corrected | null | 10.1016/j.physletb.2021.136768 | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | In this letter, we show that the wino-Higgsino dark matter (DM) is detectable
in near future DM direct detection experiments for almost all consistent
parameter space in the spontaneously broken supergravity (SUGRA) if the muon
g-2 anomaly is explained by the wino-Higgsino loop diagrams. We also point out
that the present and future LHC experiments can exclude or confirm this SUGRA
explanation of the observed muon g-2 anomaly.
| [
{
"created": "Wed, 7 Apr 2021 16:23:13 GMT",
"version": "v1"
},
{
"created": "Thu, 8 Apr 2021 14:52:30 GMT",
"version": "v2"
}
] | 2021-11-10 | [
[
"Iwamoto",
"Sho",
""
],
[
"Yanagida",
"Tsutomu T.",
""
],
[
"Yokozaki",
"Norimi",
""
]
] | In this letter, we show that the wino-Higgsino dark matter (DM) is detectable in near future DM direct detection experiments for almost all consistent parameter space in the spontaneously broken supergravity (SUGRA) if the muon g-2 anomaly is explained by the wino-Higgsino loop diagrams. We also point out that the present and future LHC experiments can exclude or confirm this SUGRA explanation of the observed muon g-2 anomaly. |
1112.5978 | Mikolaj Misiak | Mikolaj Misiak | Rare B-Meson Decays | Talk presented at the 15th Lomonosov Conference on Elementary
Particle Physics, Moscow, Russia, August 18-24th, 2011. 5 pages, no figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Rare decays of the B-meson that arise due to loop-mediated FCNC transitions
are known to provide important constraints on beyond-SM theories. Basic
properties of several such decays are reviewed here.
| [
{
"created": "Tue, 27 Dec 2011 15:46:58 GMT",
"version": "v1"
}
] | 2011-12-30 | [
[
"Misiak",
"Mikolaj",
""
]
] | Rare decays of the B-meson that arise due to loop-mediated FCNC transitions are known to provide important constraints on beyond-SM theories. Basic properties of several such decays are reviewed here. |
hep-ph/0409271 | Ulrich Jentschura | Ulrich D. Jentschura | Two-Loop Bethe Logarithms for Higher Excited S Levels | 14 pages, RevTeX, to appear in Phys. Rev. A | Phys.Rev. A70 (2004) 052108 | 10.1103/PhysRevA.70.052108 | null | hep-ph | null | Processes mediated by two virtual low-energy photons contribute quite
significantly to the energy of hydrogenic S states. The corresponding level
shift is of the order of (alpha/pi)^2 (Zalpha)^6 m_e c^2 and may be ascribed to
a two-loop generalization of the Bethe logarithm. For 1S and 2S states, the
correction has recently been evaluated by Pachucki and Jentschura [Phys. Rev.
Lett. vol. 91, 113005 (2003)]. Here, we generalize the approach to higher
excited S states, which in contrast to the 1S and 2S states can decay to P
states via the electric-dipole (E1) channel. The more complex structure of the
excited-state wave functions and the necessity to subtract P-state poles lead
to additional calculational problems. In addition to the calculation of the
excited-state two-loop energy shift, we investigate the ambiguity in the energy
level definition due to squared decay rates.
| [
{
"created": "Thu, 23 Sep 2004 15:12:06 GMT",
"version": "v1"
},
{
"created": "Thu, 23 Sep 2004 21:36:04 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Jentschura",
"Ulrich D.",
""
]
] | Processes mediated by two virtual low-energy photons contribute quite significantly to the energy of hydrogenic S states. The corresponding level shift is of the order of (alpha/pi)^2 (Zalpha)^6 m_e c^2 and may be ascribed to a two-loop generalization of the Bethe logarithm. For 1S and 2S states, the correction has recently been evaluated by Pachucki and Jentschura [Phys. Rev. Lett. vol. 91, 113005 (2003)]. Here, we generalize the approach to higher excited S states, which in contrast to the 1S and 2S states can decay to P states via the electric-dipole (E1) channel. The more complex structure of the excited-state wave functions and the necessity to subtract P-state poles lead to additional calculational problems. In addition to the calculation of the excited-state two-loop energy shift, we investigate the ambiguity in the energy level definition due to squared decay rates. |
hep-ph/0306078 | Luis Anchordoqui | Luis A. Anchordoqui | Prospects for discovery of physics beyond the Standard Model at the
Pierre Auger Observatory | (v1) Talk given at the SUGRA 20 Meeting, Boston 2003.
http://www.sugra20.neu.edu To be published in the Conference Proceedings.
(v2) References added | null | null | null | hep-ph astro-ph gr-qc hep-ex | null | I summarize the discovery potential for physics beyond the electroweak scale
at the Pierre Auger Observatory. This observatory is designed to study
ultra-high energy cosmic rays with unprecedented precision, with the primary
goal of shedding light on their composition and origins. In addition, since the
center-of-mass energies of Auger events are well beyond those reached at
terrestrial colliders, they provide an opportunity to search for new physics. I
discuss here some of the relevant observables and techniques which may be used
to weed out theories beyond the standard model.
| [
{
"created": "Tue, 10 Jun 2003 15:24:27 GMT",
"version": "v1"
},
{
"created": "Mon, 7 Jul 2003 15:07:20 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Anchordoqui",
"Luis A.",
""
]
] | I summarize the discovery potential for physics beyond the electroweak scale at the Pierre Auger Observatory. This observatory is designed to study ultra-high energy cosmic rays with unprecedented precision, with the primary goal of shedding light on their composition and origins. In addition, since the center-of-mass energies of Auger events are well beyond those reached at terrestrial colliders, they provide an opportunity to search for new physics. I discuss here some of the relevant observables and techniques which may be used to weed out theories beyond the standard model. |
hep-ph/9512363 | null | C. Glenn Boyd and Richard F. Lebed | Improved QCD Form Factor Constraints and Lambda_b --> Lambda_c l nu | 19 pages, 2 figures, one in eps, one in ps; uses epsf.tex and
lanlmac.tex (harvmac.tex). Version accepted by Nuc. Phys. B. Includes a more
detailed discussion of branch cuts and minor modifications to wording and
numerical results | Nucl.Phys. B485 (1997) 275-290 | null | UCSD/PTH 95-23 | hep-ph | null | We construct model-independent parametrizations of the individual QCD form
factors relevant to Lambda_b --> Lambda_c l nu decays. These results follow
from dispersion relations and analyticity, and incorporate an improvement in
the technique that reduces the number of necessary parameters. To describe most
form factors with 5%--10% accuracy over the entire kinematic range, three
parameters are necessary, one of which is its normalization at zero recoil. We
also apply the improvement to meson decays, and find, using the heavy quark
form factor normalization, that almost every B --> D l nu and B --> D^* l nu
form factor is well-described by a single-variable parametrization. B --> pi l
nu requires a total of only 3 to 5 parameters, depending on the desired
accuracy.
| [
{
"created": "Wed, 20 Dec 1995 00:00:50 GMT",
"version": "v1"
},
{
"created": "Thu, 17 Oct 1996 17:53:15 GMT",
"version": "v2"
}
] | 2008-02-03 | [
[
"Boyd",
"C. Glenn",
""
],
[
"Lebed",
"Richard F.",
""
]
] | We construct model-independent parametrizations of the individual QCD form factors relevant to Lambda_b --> Lambda_c l nu decays. These results follow from dispersion relations and analyticity, and incorporate an improvement in the technique that reduces the number of necessary parameters. To describe most form factors with 5%--10% accuracy over the entire kinematic range, three parameters are necessary, one of which is its normalization at zero recoil. We also apply the improvement to meson decays, and find, using the heavy quark form factor normalization, that almost every B --> D l nu and B --> D^* l nu form factor is well-described by a single-variable parametrization. B --> pi l nu requires a total of only 3 to 5 parameters, depending on the desired accuracy. |
hep-ph/0111029 | Csaba Balazs | Howard Baer, Csaba Balazs, J.Kenichi Mizukoshi | The complementary roles of the LHC and the LC in discovering
supersymmetry | 3 pages, 4 figures. Contribution to Snowmass 2001 | eConf C010630 (2001) P348 | null | null | hep-ph | null | We address the complementarity of the CERN Large Hadron Collider and an $e^+
e^-$ Linear Collider in determining SUSY model parameters for a particular
SO(10) SUSY GUT case study.
| [
{
"created": "Fri, 2 Nov 2001 20:37:28 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Baer",
"Howard",
""
],
[
"Balazs",
"Csaba",
""
],
[
"Mizukoshi",
"J. Kenichi",
""
]
] | We address the complementarity of the CERN Large Hadron Collider and an $e^+ e^-$ Linear Collider in determining SUSY model parameters for a particular SO(10) SUSY GUT case study. |
1608.03982 | Alfredo Valcarce | J. Vijande, A. Valcarce, J.-M. Richard, and P. Sorba | Search for doubly-heavy dibaryons in a quark model | 6 pages. To be published in Phys. Rev. D | Phys. Rev. D 94, 034038 (2016) | 10.1103/PhysRevD.94.034038 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the stability of hexaquark systems containing two heavy quarks and
four light quarks within a simple quark model. No bound or metastable state is
found. The reason stems on a delicate interplay between chromoelectric and
chromomagnetic effects. Our calculation provides also information about
anticharmed pentaquarks that are seemingly unbound in simple quark models.
| [
{
"created": "Sat, 13 Aug 2016 13:38:49 GMT",
"version": "v1"
}
] | 2016-08-26 | [
[
"Vijande",
"J.",
""
],
[
"Valcarce",
"A.",
""
],
[
"Richard",
"J. -M.",
""
],
[
"Sorba",
"P.",
""
]
] | We study the stability of hexaquark systems containing two heavy quarks and four light quarks within a simple quark model. No bound or metastable state is found. The reason stems on a delicate interplay between chromoelectric and chromomagnetic effects. Our calculation provides also information about anticharmed pentaquarks that are seemingly unbound in simple quark models. |
hep-ph/0701100 | Marcelo Loewe | M.L. El-Sheikh and M. Loewe | Isospin Chemical potential and temperature effects in the Linear Sigma
Model | 12 pages, 10 figures. A new reference has been added and some typos
have been corrected | null | null | null | hep-ph | null | In this letter we explore the temperature and isospin chemical potential
($\mu_I$) dependence of the vacuum structure and the meson masses in the linear
sigma model, at the one loop level. The sigma meson mass grows steadily with
temperature. This behavior does not agree with previous mean field
calculations. For the pion our results show the same behavior as the mean field
approach. The stability of the vacuum has a very soft dependence on $\mu_I$
since this is a second order effect in the tadpole diagrams.
| [
{
"created": "Fri, 12 Jan 2007 20:13:43 GMT",
"version": "v1"
},
{
"created": "Wed, 17 Jan 2007 14:48:49 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"El-Sheikh",
"M. L.",
""
],
[
"Loewe",
"M.",
""
]
] | In this letter we explore the temperature and isospin chemical potential ($\mu_I$) dependence of the vacuum structure and the meson masses in the linear sigma model, at the one loop level. The sigma meson mass grows steadily with temperature. This behavior does not agree with previous mean field calculations. For the pion our results show the same behavior as the mean field approach. The stability of the vacuum has a very soft dependence on $\mu_I$ since this is a second order effect in the tadpole diagrams. |
hep-ph/0702130 | Felipe J. Llanes-Estrada | Antonio Dobado Gonzalez, Felipe J. Llanes-Estrada and Juan M. Torres
Rincon (U. Complutense Madrid) | Heat conductivity of a pion gas | 3 pgs., 3 figs., Contribution to the proceedings of QNP06, IVth
Intnal. Conference on Quarks and Nuclear Physics, Madrid June 5th-10th 2006 | null | null | null | hep-ph | null | We evaluate the heat conductivity of a dilute pion gas employing the
Uehling-Uehlenbeck equation and experimental phase-shifts parameterized by
means of the SU(2) Inverse Amplitude Method. Our results are consistent with
previous evaluations. For comparison we also give results for an (unphysical)
hard sphere gas.
| [
{
"created": "Tue, 13 Feb 2007 15:07:32 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Gonzalez",
"Antonio Dobado",
"",
"U. Complutense Madrid"
],
[
"Llanes-Estrada",
"Felipe J.",
"",
"U. Complutense Madrid"
],
[
"Rincon",
"Juan M. Torres",
"",
"U. Complutense Madrid"
]
] | We evaluate the heat conductivity of a dilute pion gas employing the Uehling-Uehlenbeck equation and experimental phase-shifts parameterized by means of the SU(2) Inverse Amplitude Method. Our results are consistent with previous evaluations. For comparison we also give results for an (unphysical) hard sphere gas. |
hep-ph/0012294 | null | Alexandre A. Osipov and Brigitte Hiller (University of Coimbra,
Portugal) | Generalized Proper-Time Approach For The Case Of Broken Isospin Symmetry | 24 pages, plain LaTeX, no figures | Phys.Rev.D63:094009,2001 | 10.1103/PhysRevD.63.094009 | null | hep-ph | null | We present a derivation of the low-energy effective meson Lagrangian of the
Nambu -- Jona-Lasinio (NJL) model on the basis of Schwinger's proper-time
regularization of the one-loop fermion determinant. We consider the case in
which the $SU(2)\times SU(2)$ chiral symmetry of the NJL Lagrangian is broken
by the current quark mass matrix with $\hat{m}_u\ne\hat{m}_d$. The
non-degeneracy of $d$ and $u$ masses destroys one of the most crucial features
of the proper-time expansion -- the chiral-invariant structure of Seeley --
DeWitt coefficients. We show however that systematic resummations inside the
proper-time expansion are still possible and derive a result which is in full
agreement with the chiral Ward -- Takahashi identities.
| [
{
"created": "Thu, 21 Dec 2000 17:36:19 GMT",
"version": "v1"
}
] | 2011-02-01 | [
[
"Osipov",
"Alexandre A.",
"",
"University of Coimbra,\n Portugal"
],
[
"Hiller",
"Brigitte",
"",
"University of Coimbra,\n Portugal"
]
] | We present a derivation of the low-energy effective meson Lagrangian of the Nambu -- Jona-Lasinio (NJL) model on the basis of Schwinger's proper-time regularization of the one-loop fermion determinant. We consider the case in which the $SU(2)\times SU(2)$ chiral symmetry of the NJL Lagrangian is broken by the current quark mass matrix with $\hat{m}_u\ne\hat{m}_d$. The non-degeneracy of $d$ and $u$ masses destroys one of the most crucial features of the proper-time expansion -- the chiral-invariant structure of Seeley -- DeWitt coefficients. We show however that systematic resummations inside the proper-time expansion are still possible and derive a result which is in full agreement with the chiral Ward -- Takahashi identities. |
0801.0041 | Nick Kersting | P. Huang, N. Kersting, H.H. Yang | Extracting MSSM Masses From Heavy Higgs Decays to Four Leptons at the
LHC | version to be published in PRD | Phys.Rev.D77:075011,2008 | 10.1103/PhysRevD.77.075011 | SCUPHY-TH-08001 | hep-ph | null | It is well known that finding and measuring the masses of particles in the
Minimal Supersymmetric Standard Model (MSSM) at the Large Hadron Collider (LHC)
may be possible using invariant mass distributions in exclusive channels
containing n_j jets and n_l leptons. We perform this analysis for the (n_j,
n_l) = (0,4) decay of heavy Higgs bosons to neutralinos, pp \to H/A \to \chi_i
\chi_j (i,j =2,3,4), which then decay to four leptons and two lightest
neutralinos \chi_1 via on-shell sleptons. When i=j and the sleptons are
degenerate, our Monte Carlo study shows that the LHC will be able to measure
the Higgs and relevant neutralino and slepton masses to roughly
30%; however, if one of these is already known within 5%, the other three may
be found to equal or better accuracy. This would provide the first accurate
measurement of the H/A mass via invariant mass distribution techniques.
| [
{
"created": "Sat, 29 Dec 2007 14:12:19 GMT",
"version": "v1"
},
{
"created": "Thu, 10 Jan 2008 18:03:07 GMT",
"version": "v2"
},
{
"created": "Tue, 11 Mar 2008 13:55:55 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Huang",
"P.",
""
],
[
"Kersting",
"N.",
""
],
[
"Yang",
"H. H.",
""
]
] | It is well known that finding and measuring the masses of particles in the Minimal Supersymmetric Standard Model (MSSM) at the Large Hadron Collider (LHC) may be possible using invariant mass distributions in exclusive channels containing n_j jets and n_l leptons. We perform this analysis for the (n_j, n_l) = (0,4) decay of heavy Higgs bosons to neutralinos, pp \to H/A \to \chi_i \chi_j (i,j =2,3,4), which then decay to four leptons and two lightest neutralinos \chi_1 via on-shell sleptons. When i=j and the sleptons are degenerate, our Monte Carlo study shows that the LHC will be able to measure the Higgs and relevant neutralino and slepton masses to roughly 30%; however, if one of these is already known within 5%, the other three may be found to equal or better accuracy. This would provide the first accurate measurement of the H/A mass via invariant mass distribution techniques. |
hep-ph/9808401 | Tony Gherghetta | T.Gherghetta, G.F.Giudice and A.Riotto | Nucleosynthesis Bounds in Gauge-Mediated Supersymmetry Breaking Theories | 13 pages, 4 figures, LaTeX | Phys.Lett. B446 (1999) 28-36 | 10.1016/S0370-2693(98)01527-5 | CERN-TH/98-271 | hep-ph astro-ph | null | In gauge-mediated supersymmetry breaking theories the next-to-lightest
supersymmetric particle can decay during or after the nucleosynthesis epoch.
The decay products such as photons and hadrons can destroy the light element
abundances. Restricting the damage that these decays can do leads to
constraints on the abundance and lifetime of the NLSP. We compute the freezeout
abundance of the NLSP by including all coannhilation thresholds which are
particularly important in the case in which the NLSP is the lightest stau. We
find that the upper bound on the messenger scale can be as stringent as 10^12
GeV when the NLSP is the lightest neutralino and 10^13 GeV when the NLSP is the
lightest stau. Our findings disfavour models of gauge mediation where the
messenger scale is close to the GUT scale or results from balancing
renormalisable interactions with non-renormalisable operators at the Planck
scale. When combined with the requirement of no gravitino overabundance, our
bound implies that the reheating temperature after inflation must be less than
10^7 GeV.
| [
{
"created": "Mon, 24 Aug 1998 17:41:22 GMT",
"version": "v1"
}
] | 2015-06-25 | [
[
"Gherghetta",
"T.",
""
],
[
"Giudice",
"G. F.",
""
],
[
"Riotto",
"A.",
""
]
] | In gauge-mediated supersymmetry breaking theories the next-to-lightest supersymmetric particle can decay during or after the nucleosynthesis epoch. The decay products such as photons and hadrons can destroy the light element abundances. Restricting the damage that these decays can do leads to constraints on the abundance and lifetime of the NLSP. We compute the freezeout abundance of the NLSP by including all coannhilation thresholds which are particularly important in the case in which the NLSP is the lightest stau. We find that the upper bound on the messenger scale can be as stringent as 10^12 GeV when the NLSP is the lightest neutralino and 10^13 GeV when the NLSP is the lightest stau. Our findings disfavour models of gauge mediation where the messenger scale is close to the GUT scale or results from balancing renormalisable interactions with non-renormalisable operators at the Planck scale. When combined with the requirement of no gravitino overabundance, our bound implies that the reheating temperature after inflation must be less than 10^7 GeV. |
hep-ph/0410016 | Biagio Lucini | Biagio Lucini | The large $N$ limit from the lattice | Talk presented at Light-Cone 2004, Amsterdam, 16 - 20 August 2004. 6
pages, 4 figures. Include latex style files | Few Body Syst. 36 (2005) 161-166 | 10.1007/s00601-004-0094-7 | null | hep-ph hep-lat hep-th | null | A numerical study of the string tension and of the masses of the lowest-lying
glueballs is performed in SU($N$) gauge theories for $2 \le N \le 8$ in D=3+1
and $2 \le N \le 6$ in D=2+1. It is shown that for the string tension a smooth
$N \to \infty$ limit exists that depends only on the 't Hooft coupling $\lambda
= g^2 N$. An extrapolation of the masses of the lightest glueballs to $N =
\infty$ using a power series in $1/N^2$ shows that the leading correction to
the infinite $N$ value accounts for finite $N$ effects for $N$ at least as
small as 3 and all the way down to N=2 in many cases. $k$-string tension ratios
and possible issues connected with correlation functions at large $N$ are also
discussed.
| [
{
"created": "Fri, 1 Oct 2004 14:44:14 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Lucini",
"Biagio",
""
]
] | A numerical study of the string tension and of the masses of the lowest-lying glueballs is performed in SU($N$) gauge theories for $2 \le N \le 8$ in D=3+1 and $2 \le N \le 6$ in D=2+1. It is shown that for the string tension a smooth $N \to \infty$ limit exists that depends only on the 't Hooft coupling $\lambda = g^2 N$. An extrapolation of the masses of the lightest glueballs to $N = \infty$ using a power series in $1/N^2$ shows that the leading correction to the infinite $N$ value accounts for finite $N$ effects for $N$ at least as small as 3 and all the way down to N=2 in many cases. $k$-string tension ratios and possible issues connected with correlation functions at large $N$ are also discussed. |
1306.0252 | Zakhar Khaidukov | Zakhar Khaidukov | Q-balls and the chiral vortical effect | 5 pages | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The paper considers the possibility of the existence of the axial current,
that is directed along the axis of rotation and arises due to the presence of
the Q-ball.
| [
{
"created": "Sun, 2 Jun 2013 21:41:05 GMT",
"version": "v1"
}
] | 2013-06-04 | [
[
"Khaidukov",
"Zakhar",
""
]
] | The paper considers the possibility of the existence of the axial current, that is directed along the axis of rotation and arises due to the presence of the Q-ball. |
hep-ph/9701375 | Matthias Neubert | G. Amor\'os, M. Beneke and M. Neubert (CERN) | Two-Loop Anomalous Dimension of the Chromo-Magnetic Moment of a Heavy
Quark | 13 pages, 4 figures | Phys.Lett. B401 (1997) 81-90 | 10.1016/S0370-2693(97)00345-6 | CERN-TH/97-3 | hep-ph | null | We find that the anomalous dimension (in the $\bar{MS}$ scheme) of the
chromo-magnetic operator $g_s\bar h_v\sigma_{\mu\nu} G^{\mu\nu} h_v$ in the
heavy-quark effective theory is \gamma_{mag} = (C_A\alpha_s / 2\pi) [1 + (
17/18 C_A - 13/18 T_F n_f)\alpha_s/\pi + O(\alpha_s^2)] generalizing the
one-loop expression known previously. To derive the two-loop result, we use the
reparametrization invariance and the virial theorem. After performing infrared
subtractions, all two-loop integrals are of propagator type and are evaluated
by a recurrence relation for tensor integrals.
| [
{
"created": "Fri, 24 Jan 1997 18:32:56 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Amorós",
"G.",
"",
"CERN"
],
[
"Beneke",
"M.",
"",
"CERN"
],
[
"Neubert",
"M.",
"",
"CERN"
]
] | We find that the anomalous dimension (in the $\bar{MS}$ scheme) of the chromo-magnetic operator $g_s\bar h_v\sigma_{\mu\nu} G^{\mu\nu} h_v$ in the heavy-quark effective theory is \gamma_{mag} = (C_A\alpha_s / 2\pi) [1 + ( 17/18 C_A - 13/18 T_F n_f)\alpha_s/\pi + O(\alpha_s^2)] generalizing the one-loop expression known previously. To derive the two-loop result, we use the reparametrization invariance and the virial theorem. After performing infrared subtractions, all two-loop integrals are of propagator type and are evaluated by a recurrence relation for tensor integrals. |
hep-ph/9711425 | Cliff Burgess | C.P. Burgess | Solar Fluctuations and the MSW Effect | 10 pages, LaTeX, talk given at the Erice School on Neutrinos in
Astro, Particle and Nuclear Physics | Prog.Part.Nucl.Phys. 40 (1998) 137-146 | 10.1016/S0146-6410(98)00018-0 | McGill-97/32 | hep-ph astro-ph nucl-th | null | This talk summarizes the results of recent calculations of how fluctuations
within the solar medium can influence resonant neutrino oscillations within the
sun. Although initial calculations pointed to helioseismic waves as possibly
producing detectable effects, recent more careful calculations show this not to
be true. Those features of fluctuations which maximize their influence on
neutrino propagation are identified, and are likely to have implications for
supernovae and the early universe.
| [
{
"created": "Fri, 21 Nov 1997 22:34:08 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Burgess",
"C. P.",
""
]
] | This talk summarizes the results of recent calculations of how fluctuations within the solar medium can influence resonant neutrino oscillations within the sun. Although initial calculations pointed to helioseismic waves as possibly producing detectable effects, recent more careful calculations show this not to be true. Those features of fluctuations which maximize their influence on neutrino propagation are identified, and are likely to have implications for supernovae and the early universe. |
1107.1343 | Chun-Yu Cui | Chun-Yu Cui, Yong-Lu Liu and Ming-Qiu Huang | Investigating different structures of the Z_{b}(10610) and Z_{b}(10650) | 17 pages, 9 figures | Phys. Rev. D 85, 074014 (2012) | 10.1103/PhysRevD.85.074014 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The recently observed narrow resonance $Z_{b}(10610)$ is examined with the
assumptions both as a $B^{*}\bar{B}$ molecular state and a
$[bd][\bar{b}\bar{u}]$ tetraquark state with quantum numbers
$I^{G}J^{P}=1^{+}1^{+}$. Possible interpolating currents are constructed to
describe the $Z_{b}(10650)$ as an axial-vector $B^{*}\bar{B}^{*}$ molecular
state or a $[bd][\bar{b}\bar{u}]$ tetraquark state. Using QCD sum rules
(QCDSR), we consider contributions up to dimension six in the operator product
expansion (OPE) at the leading order in $\alpha_{s}$. The mass is obtained as
$(10.44\pm0.23) GeV$ for molecular state and $(10.50\pm0.19) GeV$ for
tetraquark state, both of which coincide with the $Z_{b}(10610)$. The results
$m_{B^{*}\bar{B}^{*}}=(10.45\pm0.31) GeV$ and
$m_{[bd][\bar{b}\bar{u}]}=(10.48\pm0.33) GeV$ are consistent with the
$Z_{b}(10650)$.
| [
{
"created": "Thu, 7 Jul 2011 11:09:13 GMT",
"version": "v1"
},
{
"created": "Fri, 11 Nov 2011 18:10:09 GMT",
"version": "v2"
},
{
"created": "Wed, 18 Apr 2012 07:42:42 GMT",
"version": "v3"
}
] | 2012-04-19 | [
[
"Cui",
"Chun-Yu",
""
],
[
"Liu",
"Yong-Lu",
""
],
[
"Huang",
"Ming-Qiu",
""
]
] | The recently observed narrow resonance $Z_{b}(10610)$ is examined with the assumptions both as a $B^{*}\bar{B}$ molecular state and a $[bd][\bar{b}\bar{u}]$ tetraquark state with quantum numbers $I^{G}J^{P}=1^{+}1^{+}$. Possible interpolating currents are constructed to describe the $Z_{b}(10650)$ as an axial-vector $B^{*}\bar{B}^{*}$ molecular state or a $[bd][\bar{b}\bar{u}]$ tetraquark state. Using QCD sum rules (QCDSR), we consider contributions up to dimension six in the operator product expansion (OPE) at the leading order in $\alpha_{s}$. The mass is obtained as $(10.44\pm0.23) GeV$ for molecular state and $(10.50\pm0.19) GeV$ for tetraquark state, both of which coincide with the $Z_{b}(10610)$. The results $m_{B^{*}\bar{B}^{*}}=(10.45\pm0.31) GeV$ and $m_{[bd][\bar{b}\bar{u}]}=(10.48\pm0.33) GeV$ are consistent with the $Z_{b}(10650)$. |
hep-ph/9512308 | Kraizelman Riva | Paul Singer(Technion,Haifa,Israel) | Weak Radiative Decays of Hyperons and of Charm and Beauty Baryons | 9 pages. Invited Lecture at the Conference on "Production and Decay
of Hyperons, Charm and Beauty Hadrons",September 5-8,1995;Strasbourg, France | Nucl.Phys.Proc.Suppl. 50 (1996) 202-210 | 10.1016/0920-5632(96)00392-1 | null | hep-ph | null | A review is presented of the weak radiative decays of baryons.It includes an
anlysis of the possible contributions of electromagnetic penguins to these
decays,a survey of the difficulties still encountered in the sector of hyperon
decays and a short account on some new developments on this topic. The
theoretical treatments on charm and beauty baryon decays are summarized,with a
good outlook for their detection.
| [
{
"created": "Thu, 14 Dec 1995 11:38:22 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Singer",
"Paul",
"",
"Technion,Haifa,Israel"
]
] | A review is presented of the weak radiative decays of baryons.It includes an anlysis of the possible contributions of electromagnetic penguins to these decays,a survey of the difficulties still encountered in the sector of hyperon decays and a short account on some new developments on this topic. The theoretical treatments on charm and beauty baryon decays are summarized,with a good outlook for their detection. |
2112.14076 | Fernando Alvarado | Fernando Alvarado and Luis Alvarez-Ruso | Light-quark mass dependence of the nucleon axial charge and pion-nucleon
scattering phenomenology | Minor change: corrected a term in the expression "dZDlessp3" in the
Mathematica notebook | Phys. Rev. D 105, 074001 (2022) | 10.1103/PhysRevD.105.074001 | null | hep-ph hep-lat nucl-th | http://creativecommons.org/licenses/by/4.0/ | The light-quark mass dependence of the nucleon axial isovector charge ($g_A$)
has been studied up to next-to-next-to-leading order, $O(p^4)$, in relativistic
chiral perturbation theory using extended-on-mass-shell renormalization,
without and with explicit $\Delta (1232)$ degrees of freedom. We show that in
the $\Delta$-less case, at this order, the flat trend of $g_A (M_{\pi})$
exhibited by state-of-the-art lattice QCD (LQCD) results cannot be reproduced
using low energy constants (LECs) extracted from pion-nucleon elastic and
inelastic scattering. A satisfactory description of these LQCD data is only
achieved in the theory with $\Delta$. From this fit we report $g_A
(M_{\pi\rm{(phys)}}) = 1.260 \pm 0.012$, close to the experimental result, and
$d_{16}= -0.88\pm 0.88$ GeV$^{-2}$, in agreement with its empirical value. The
large uncertainties are of theoretical origin, reflecting the difference
between $O(p^3)$ and $O(p^4)$ that still persists at large $M_{\pi}$ in
presence of the $\Delta$.
| [
{
"created": "Tue, 28 Dec 2021 10:17:34 GMT",
"version": "v1"
},
{
"created": "Thu, 14 Apr 2022 09:32:05 GMT",
"version": "v2"
},
{
"created": "Wed, 29 Jun 2022 15:46:04 GMT",
"version": "v3"
}
] | 2022-06-30 | [
[
"Alvarado",
"Fernando",
""
],
[
"Alvarez-Ruso",
"Luis",
""
]
] | The light-quark mass dependence of the nucleon axial isovector charge ($g_A$) has been studied up to next-to-next-to-leading order, $O(p^4)$, in relativistic chiral perturbation theory using extended-on-mass-shell renormalization, without and with explicit $\Delta (1232)$ degrees of freedom. We show that in the $\Delta$-less case, at this order, the flat trend of $g_A (M_{\pi})$ exhibited by state-of-the-art lattice QCD (LQCD) results cannot be reproduced using low energy constants (LECs) extracted from pion-nucleon elastic and inelastic scattering. A satisfactory description of these LQCD data is only achieved in the theory with $\Delta$. From this fit we report $g_A (M_{\pi\rm{(phys)}}) = 1.260 \pm 0.012$, close to the experimental result, and $d_{16}= -0.88\pm 0.88$ GeV$^{-2}$, in agreement with its empirical value. The large uncertainties are of theoretical origin, reflecting the difference between $O(p^3)$ and $O(p^4)$ that still persists at large $M_{\pi}$ in presence of the $\Delta$. |
1210.5347 | Tom Zirke | Oliver Brein, Robert V. Harlander, Tom J. E. Zirke | vh@nnlo - Higgs Strahlung at hadron colliders | 16 pages, 4 Figures; v2: reference added, some typos removed, version
published in CPC | Computer Physics Communications 184 (2013) pp. 998-1003 | 10.1016/j.cpc.2012.11.002 | WUB/12-20 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A numerical program for the evaluation of the inclusive cross section for
associated Higgs production with a massive weak gauge boson at hadron colliders
is described, sigma(pp/pbar p -> HV), V=W,Z. The calculation is performed in
the framework of the Standard Model and includes next-to-next-to-leading order
QCD as well as next-to-leading order electro-weak effects.
| [
{
"created": "Fri, 19 Oct 2012 09:04:24 GMT",
"version": "v1"
},
{
"created": "Thu, 13 Dec 2012 08:44:17 GMT",
"version": "v2"
}
] | 2012-12-20 | [
[
"Brein",
"Oliver",
""
],
[
"Harlander",
"Robert V.",
""
],
[
"Zirke",
"Tom J. E.",
""
]
] | A numerical program for the evaluation of the inclusive cross section for associated Higgs production with a massive weak gauge boson at hadron colliders is described, sigma(pp/pbar p -> HV), V=W,Z. The calculation is performed in the framework of the Standard Model and includes next-to-next-to-leading order QCD as well as next-to-leading order electro-weak effects. |
hep-ph/0603152 | Alison Demaria | Alison Demaria, Catherine I. Low and Raymond R. Volkas | Neutrino masses in quartification schemes | 12 pages, minor changes. To appear in Phys. Rev.D | Phys.Rev. D74 (2006) 033005 | 10.1103/PhysRevD.74.033005 | null | hep-ph | null | The idea of quark-lepton universality at high energies has recently been
explored in unified theories based upon the quartification gauge group SU(3)^4.
These schemes encompass a quark-lepton exchange symmetry that results upon the
introduction of leptonic colour. It has been demonstrated that in models in
which the quartification gauge symmetry is broken down to the standard model
gauge group, gauge coupling constant unification can be achieved, and there is
no unique scenario. The same is also true when the leptonic colour gauge group
is only partially broken, leaving a remnant SU(2)_\ell symmetry at the standard
model level. Here we perform an analysis of the neutrino mass spectrum of such
models. We show that these models do not naturally generate small Majorana
neutrino masses, thus correcting an error in our earlier quartification paper,
but with the addition of one singlet neutral fermion per family there is a
realisation of see-saw suppressed masses for the neutrinos. We also show that
these schemes are consistent with proton decay.
| [
{
"created": "Mon, 20 Mar 2006 22:29:28 GMT",
"version": "v1"
},
{
"created": "Thu, 20 Jul 2006 23:36:18 GMT",
"version": "v2"
}
] | 2009-11-11 | [
[
"Demaria",
"Alison",
""
],
[
"Low",
"Catherine I.",
""
],
[
"Volkas",
"Raymond R.",
""
]
] | The idea of quark-lepton universality at high energies has recently been explored in unified theories based upon the quartification gauge group SU(3)^4. These schemes encompass a quark-lepton exchange symmetry that results upon the introduction of leptonic colour. It has been demonstrated that in models in which the quartification gauge symmetry is broken down to the standard model gauge group, gauge coupling constant unification can be achieved, and there is no unique scenario. The same is also true when the leptonic colour gauge group is only partially broken, leaving a remnant SU(2)_\ell symmetry at the standard model level. Here we perform an analysis of the neutrino mass spectrum of such models. We show that these models do not naturally generate small Majorana neutrino masses, thus correcting an error in our earlier quartification paper, but with the addition of one singlet neutral fermion per family there is a realisation of see-saw suppressed masses for the neutrinos. We also show that these schemes are consistent with proton decay. |
1607.03125 | Sylvain Fichet | Sylvain Fichet, Gero von Gersdorff, Eduardo Ponton, Rogerio Rosenfeld | The Excitation of the Global Symmetry-Breaking Vacuum in Composite Higgs
Models | 27 pages, 2 figures. v3: References and comments added. Matches JHEP
version | null | 10.1007/JHEP09(2016)158 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider scenarios of Higgs compositeness where the Higgs doublet arises
as a pseudo-Nambu Goldstone boson. Our focus is the physical scalar ("radial")
excitation associated with the global symmetry breaking vacuum, which we call
the "global Higgs". For the minimal case of a $SO(5)/SO(4)$ coset, the
couplings of the global Higgs to Standard Model (SM) particles are fully
determined by group theoretical factors and two decay constants. The global
Higgs also couples to the composite resonances of the theory, inducing an
interaction with the SM gauge bosons at one-loop. We thoroughly analyze
representative fermionic sectors, considering a global Higgs both in the $\bf
5$ and $\bf 14$ representations of $SO(5)$ and taking into account the
renormalization group evolution of couplings in the composite sector. We derive
the one-loop effective couplings and all decays of the global Higgs, showing
that its decay width over mass can range from $ O (10^{-3})$ to $ O(1)$.
Because of the multiplicity of the resonances, the coupling of the global Higgs
to gluons is sizeable, potentially opening a new window into composite models
at the LHC.
| [
{
"created": "Mon, 11 Jul 2016 20:02:48 GMT",
"version": "v1"
},
{
"created": "Wed, 10 Aug 2016 18:20:31 GMT",
"version": "v2"
},
{
"created": "Wed, 28 Sep 2016 04:58:32 GMT",
"version": "v3"
}
] | 2016-11-03 | [
[
"Fichet",
"Sylvain",
""
],
[
"von Gersdorff",
"Gero",
""
],
[
"Ponton",
"Eduardo",
""
],
[
"Rosenfeld",
"Rogerio",
""
]
] | We consider scenarios of Higgs compositeness where the Higgs doublet arises as a pseudo-Nambu Goldstone boson. Our focus is the physical scalar ("radial") excitation associated with the global symmetry breaking vacuum, which we call the "global Higgs". For the minimal case of a $SO(5)/SO(4)$ coset, the couplings of the global Higgs to Standard Model (SM) particles are fully determined by group theoretical factors and two decay constants. The global Higgs also couples to the composite resonances of the theory, inducing an interaction with the SM gauge bosons at one-loop. We thoroughly analyze representative fermionic sectors, considering a global Higgs both in the $\bf 5$ and $\bf 14$ representations of $SO(5)$ and taking into account the renormalization group evolution of couplings in the composite sector. We derive the one-loop effective couplings and all decays of the global Higgs, showing that its decay width over mass can range from $ O (10^{-3})$ to $ O(1)$. Because of the multiplicity of the resonances, the coupling of the global Higgs to gluons is sizeable, potentially opening a new window into composite models at the LHC. |
hep-ph/0102001 | Chikage Habe | K. Fujii, C. Habe (Hokkaido Univi.), T. Yabuki (Rakunou Gakuen Univ.) | Remarks on flavor-neutrino propagators and oscillation formulae | revtex, 16 pages | Phys.Rev. D64 (2001) 013011 | 10.1103/PhysRevD.64.013011 | null | hep-ph | null | We examine the general structure of the formulae of neutrino oscillations
proposed by Blasone and Vitiello(BV). Reconstructing their formulae with the
retarded propagators of the flavor neutrino fields for the case of many
flavors, we can get easily the formulae which satisfy the suitable boundary
conditions and are independent of arbitrary mass parameters $\{\mu_{\rho}\}$,
as is obtained by BV for the case of two flavors. In this two flavor case, our
formulae reduce to those obtained by BV under $T$-invariance condition.
Furthermore, the reconstructed probabilities are shown to coincide with those
derived with recourse to the mass Hilbert space ${\cal H}_{m}$ which is
unitarily inequivalent to the flavor Hilbert space ${\cal H}_{f}$. Such a
situation is not found in the corresponding construction a la BV. Then the new
factors in the BV's formulae, which modify the usual oscill ation formulae, are
not the trace of the flavor Hilbert space construction, but come from
Bogolyubov transformation among the operators of spin-1/2 ne utrino with
different masses.
| [
{
"created": "Thu, 1 Feb 2001 05:47:16 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Fujii",
"K.",
"",
"Hokkaido Univi."
],
[
"Habe",
"C.",
"",
"Hokkaido Univi."
],
[
"Yabuki",
"T.",
"",
"Rakunou Gakuen Univ."
]
] | We examine the general structure of the formulae of neutrino oscillations proposed by Blasone and Vitiello(BV). Reconstructing their formulae with the retarded propagators of the flavor neutrino fields for the case of many flavors, we can get easily the formulae which satisfy the suitable boundary conditions and are independent of arbitrary mass parameters $\{\mu_{\rho}\}$, as is obtained by BV for the case of two flavors. In this two flavor case, our formulae reduce to those obtained by BV under $T$-invariance condition. Furthermore, the reconstructed probabilities are shown to coincide with those derived with recourse to the mass Hilbert space ${\cal H}_{m}$ which is unitarily inequivalent to the flavor Hilbert space ${\cal H}_{f}$. Such a situation is not found in the corresponding construction a la BV. Then the new factors in the BV's formulae, which modify the usual oscill ation formulae, are not the trace of the flavor Hilbert space construction, but come from Bogolyubov transformation among the operators of spin-1/2 ne utrino with different masses. |
0810.4303 | J. -Alexis Rodriguez L. | R. Martinez, J.-Alexis Rodriguez and S. Sanchez | Charged Higgs production at photon colliders in 2HDM-III | 5 pages, 4 figures, to appear Brazilian Journal of Physics | Braz.J.Phys.38:507-510,2008 | 10.1590/S0103-97332008000400025 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study charged Higgs production in the process $\gamma\gamma\to A^0\to W^-
H^+$. The processes $\gamma\gamma\to A^0$ are loop mediated in a 2HDM. This is
due to the fact that photons only couple directly to charged particles and the
Higgs only couples to particles with mass acquired via Higgs mechanism.
Although in MSSM the contribution from the process $\gamma\gamma\to A^0$ is too
small, it has been found that in a more general 2HDM it could be enhanced. On
the other hand, the boson $A^0$ can decay in $W^- H^+$ at tree level and the
charged Higgs can decay in fermions. So, the whole process under study is
$\gamma\gamma\to A^0\to (W^-\to l\nu) (H^+\to f_if_j)$ in 2HDM-III. Evidence
about charged Higgs existence could demonstrate that structure of the Higgs
sector has several multiplets.
| [
{
"created": "Thu, 23 Oct 2008 15:33:55 GMT",
"version": "v1"
}
] | 2011-08-31 | [
[
"Martinez",
"R.",
""
],
[
"Rodriguez",
"J. -Alexis",
""
],
[
"Sanchez",
"S.",
""
]
] | We study charged Higgs production in the process $\gamma\gamma\to A^0\to W^- H^+$. The processes $\gamma\gamma\to A^0$ are loop mediated in a 2HDM. This is due to the fact that photons only couple directly to charged particles and the Higgs only couples to particles with mass acquired via Higgs mechanism. Although in MSSM the contribution from the process $\gamma\gamma\to A^0$ is too small, it has been found that in a more general 2HDM it could be enhanced. On the other hand, the boson $A^0$ can decay in $W^- H^+$ at tree level and the charged Higgs can decay in fermions. So, the whole process under study is $\gamma\gamma\to A^0\to (W^-\to l\nu) (H^+\to f_if_j)$ in 2HDM-III. Evidence about charged Higgs existence could demonstrate that structure of the Higgs sector has several multiplets. |
0805.1965 | Bob Holdom | B. Holdom | New Flavor Interactions at the LHC | 11 pages, 3 figures, improved version to appear in Physics Letters B | Phys.Lett.B666:77-81,2008 | 10.1016/j.physletb.2008.07.001 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | For a new family-nonuniversal gauge interaction to be accessible at the LHC
it will most likely couple preferentially to the third family. By coupling to
all members of the third family the production of a new gauge boson (the $X$
with $M_X\approx1$ TeV) will lead to final states with a distinctive
$\tau^+\tau^-$ pair. We study the mass reconstruction of the $X$ and the cuts
that can enhance signal to background. The $X$ boson should be associated with
the physics of flavor and in the simplest picture a fourth family. We discuss
how the mass mixing between the third and fourth families affects the $X$
couplings and a possible mixing with the $Z$.
| [
{
"created": "Wed, 14 May 2008 03:16:38 GMT",
"version": "v1"
},
{
"created": "Wed, 2 Jul 2008 01:05:53 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Holdom",
"B.",
""
]
] | For a new family-nonuniversal gauge interaction to be accessible at the LHC it will most likely couple preferentially to the third family. By coupling to all members of the third family the production of a new gauge boson (the $X$ with $M_X\approx1$ TeV) will lead to final states with a distinctive $\tau^+\tau^-$ pair. We study the mass reconstruction of the $X$ and the cuts that can enhance signal to background. The $X$ boson should be associated with the physics of flavor and in the simplest picture a fourth family. We discuss how the mass mixing between the third and fourth families affects the $X$ couplings and a possible mixing with the $Z$. |
0705.2705 | Vasile Topor Pop N | V. Topor Pop, J. Barrette, C. Gale, S. Jeon (McGill Univ., Canada), M.
Gyulassy (Columbia Univ.NY, USA and FIAS, Frankfurt am Main, Germany) | (Multi)Strangeness Production in Pb+Pb collisions at LHC. HIJING/BBar
v2.0 predictions | Comments: 3 pages, 2 figures, submitted to the CERN Theory Institute
Workshop, Heavy Ion Collisions at the LHC. Last Call Predictions, May 14 -
June 8, 2007 | null | null | null | hep-ph | null | Strangeness and multi-strangeness particles production can be used to explore
the initial transient field fluctuations in heavy ion collisions. We emphasize
the role played by Junction anti-Junction (JJbar) loops and strong color
electric fields (SCF) in these collisions. Transient field fluctuations of SCF
on the baryon production in central (0-5%) Pb+Pb collisions at nucleon-nucleon
centre of mass energy of 5.5 TeV will be discussed in the framework of
HIJING/BBbar v2.0 model, looking in particular to the predicted evolution of
nuclear modification factors R_AA from RHIC to LHC energies. Our results
indicate the importance of a good description of the baseline elementary p+p
collisions at this energy.
| [
{
"created": "Fri, 18 May 2007 19:04:49 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Pop",
"V. Topor",
"",
"McGill Univ., Canada"
],
[
"Barrette",
"J.",
"",
"McGill Univ., Canada"
],
[
"Gale",
"C.",
"",
"McGill Univ., Canada"
],
[
"Jeon",
"S.",
"",
"McGill Univ., Canada"
],
[
"Gyulassy",
"M.",
"",
"Co... | Strangeness and multi-strangeness particles production can be used to explore the initial transient field fluctuations in heavy ion collisions. We emphasize the role played by Junction anti-Junction (JJbar) loops and strong color electric fields (SCF) in these collisions. Transient field fluctuations of SCF on the baryon production in central (0-5%) Pb+Pb collisions at nucleon-nucleon centre of mass energy of 5.5 TeV will be discussed in the framework of HIJING/BBbar v2.0 model, looking in particular to the predicted evolution of nuclear modification factors R_AA from RHIC to LHC energies. Our results indicate the importance of a good description of the baseline elementary p+p collisions at this energy. |
hep-ph/9503223 | null | Julian Borrill, T.W.B. Kibble, Tanmay Vachaspati and Alexander
Vilenkin | Defect Production in Slow First Order Phase Transitions | 13 pages, RevTeX, 15 uuencoded postscript figures | Phys.Rev.D52:1934-1943,1995 | 10.1103/PhysRevD.52.1934 | IMPERIAL/TP/94-95/18, CWRU-P2-1995, NI94043 | hep-ph astro-ph | null | We study the formation of vortices in a U(1) gauge theory following a
first-order transition proceeding by bubble nucleation, in particular the
effect of a low velocity of expansion of the bubble walls. To do this, we use a
two-dimensional model in which bubbles are nucleated at random points in a
plane and at random times and then expand at some velocity $v_{\rm b}<c$.
Within each bubble, the phase angle is assigned one of three discrete values.
When bubbles collide, magnetic `fluxons' appear: if the phases are different, a
fluxon--anti-fluxon pair is formed. These fluxons are eventually trapped in
three-bubble collisions when they may annihilate or form quantized vortices. We
study in particular the effect of changing the bubble expansion speed on the
vortex density and the extent of vortex--anti-vortex correlation.
| [
{
"created": "Fri, 3 Mar 1995 11:42:31 GMT",
"version": "v1"
}
] | 2010-11-01 | [
[
"Borrill",
"Julian",
""
],
[
"Kibble",
"T. W. B.",
""
],
[
"Vachaspati",
"Tanmay",
""
],
[
"Vilenkin",
"Alexander",
""
]
] | We study the formation of vortices in a U(1) gauge theory following a first-order transition proceeding by bubble nucleation, in particular the effect of a low velocity of expansion of the bubble walls. To do this, we use a two-dimensional model in which bubbles are nucleated at random points in a plane and at random times and then expand at some velocity $v_{\rm b}<c$. Within each bubble, the phase angle is assigned one of three discrete values. When bubbles collide, magnetic `fluxons' appear: if the phases are different, a fluxon--anti-fluxon pair is formed. These fluxons are eventually trapped in three-bubble collisions when they may annihilate or form quantized vortices. We study in particular the effect of changing the bubble expansion speed on the vortex density and the extent of vortex--anti-vortex correlation. |
hep-ph/9303306 | null | S. Kumano (U. Mainz and Indiana U.) | Nuclear Shadowing in a Parton Recombination Model | preprint MKPH-T-93-04, IU/NTC 92-20, 25 pages, TEX file (without
Figs. 1-14)., (address after April 1: Saga U., Japan) | Phys.Rev.C48:2016-2028,1993 | 10.1103/PhysRevC.48.2016 | null | hep-ph nucl-th | null | Deep inelastic structure functions $F_2^A(x)$ are investigated in a $Q^2$
rescaling model with parton recombination effects. We find that the model can
explain experimentally measured $F_2^A(x)$ structure functions reasonably well
in the wide Bjorken$-x$ range ($0.005<x<0.8$). In the very small $x$ region
($x<0.02$), recombination results are very sensitive to input sea-quark and
gluon distributions.
| [
{
"created": "Thu, 25 Mar 1993 17:10:00 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Kumano",
"S.",
"",
"U. Mainz and Indiana U."
]
] | Deep inelastic structure functions $F_2^A(x)$ are investigated in a $Q^2$ rescaling model with parton recombination effects. We find that the model can explain experimentally measured $F_2^A(x)$ structure functions reasonably well in the wide Bjorken$-x$ range ($0.005<x<0.8$). In the very small $x$ region ($x<0.02$), recombination results are very sensitive to input sea-quark and gluon distributions. |
1108.4640 | Bachir Moussallam | B. Moussallam | Properties of light scalar mesons in the complex plane | Talk given at the XIV international conference on hadron spectroscopy
(hadron 2011), june 2011 Munich | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The flavour and glue structure of the light scalar mesons in QCD are probed
by studying the couplings of the $\sigma(600)$ and $f_0(980)$ to the operators
$\bar{q}q$, $\theta_\mu^\mu$ and to two photons.
| [
{
"created": "Tue, 23 Aug 2011 15:51:32 GMT",
"version": "v1"
}
] | 2011-08-24 | [
[
"Moussallam",
"B.",
""
]
] | The flavour and glue structure of the light scalar mesons in QCD are probed by studying the couplings of the $\sigma(600)$ and $f_0(980)$ to the operators $\bar{q}q$, $\theta_\mu^\mu$ and to two photons. |
1802.00064 | Marco Bonvini | xFitter Developers' team: Hamed Abdolmaleki, Valerio Bertone, Daniel
Britzger, Stefano Camarda, Amanda Cooper-Sarkar, Francesco Giuli, Alexander
Glazov, Aleksander Kusina, Agnieszka Luszczak, Fred Olness, Andrey Sapronov,
Pavel Shvydkin, Katarzyna Wichmann, Oleksandr Zenaiev, and Marco Bonvini | Impact of low-$x$ resummation on QCD analysis of HERA data | 14 pages, 12 figures. Additional studies and various improvements.
EPJC version | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Fits to the final combined HERA deep-inelastic scattering cross-section data
within the conventional DGLAP framework of QCD have shown some tension at low
$x$ and low $Q^2$. A resolution of this tension incorporating
$\ln(1/x)$-resummation terms into the HERAPDF fits is investigated using the
xFitter program. The kinematic region where this resummation is important is
delineated. Such high-energy resummation not only gives a better description of
the data, particularly of the longitudinal structure function $F_L$, it also
results in a gluon PDF which is steeply rising at low $x$ for low scales, $Q^2
\simeq 2.5$ GeV$^2$, contrary to the fixed-order NLO and NNLO gluon PDF.
| [
{
"created": "Wed, 31 Jan 2018 21:00:14 GMT",
"version": "v1"
},
{
"created": "Tue, 24 Jul 2018 16:23:30 GMT",
"version": "v2"
}
] | 2018-07-25 | [
[
"team",
"xFitter Developers'",
""
],
[
":",
"",
""
],
[
"Abdolmaleki",
"Hamed",
""
],
[
"Bertone",
"Valerio",
""
],
[
"Britzger",
"Daniel",
""
],
[
"Camarda",
"Stefano",
""
],
[
"Cooper-Sarkar",
"Amanda",
"... | Fits to the final combined HERA deep-inelastic scattering cross-section data within the conventional DGLAP framework of QCD have shown some tension at low $x$ and low $Q^2$. A resolution of this tension incorporating $\ln(1/x)$-resummation terms into the HERAPDF fits is investigated using the xFitter program. The kinematic region where this resummation is important is delineated. Such high-energy resummation not only gives a better description of the data, particularly of the longitudinal structure function $F_L$, it also results in a gluon PDF which is steeply rising at low $x$ for low scales, $Q^2 \simeq 2.5$ GeV$^2$, contrary to the fixed-order NLO and NNLO gluon PDF. |
hep-ph/0204119 | Durmus Demir | D. A. Demir, Keith A. Olive, and M.B. Voloshin | The Forward-Backward Asymmetry of B to (pi,K) l^+ l^-: Supersymmetry at
Work | 18 pages; 11 eps figures; minor changes in text; journal version | Phys.Rev.D66:034015,2002 | 10.1103/PhysRevD.66.034015 | UMN-TH-2047/02, TPI-MINN-02/07 | hep-ph | null | We analyze the forward-backward asymmetry of the decays B to (pi,K) l^+ l^-
with l = mu or tau in the framework of the constrained minimal supersymmetric
standard model. We find that, the asymmetry is enhanced at large tan beta and
depends strongly on the sign of the mu parameter. For mu > 0, the asymmetry is
typically large and observable whereas for mu < 0, it changes the sign and is
suppressed by an order of magnitude. Including cosmological constraints we find
that the asymmetry has a maximal value of about 30 %, produced when Higgs- and
gauge- induced flavor violations are of comparable size, at a value of tan beta
simeq 35. The present constraints from the B-factories are too weak to
constrain parameter space, and the regions excluded by them are already
disfavoured by at least one of B to X_s gamma, g-2, and/or cosmology. The size
of the asymmetry is mainly determined by the flavor of the final state lepton
rather than the flavor of the pseudoscalar.
| [
{
"created": "Wed, 10 Apr 2002 18:53:48 GMT",
"version": "v1"
},
{
"created": "Wed, 10 Apr 2002 20:44:49 GMT",
"version": "v2"
},
{
"created": "Tue, 25 Jun 2002 21:44:58 GMT",
"version": "v3"
}
] | 2009-09-15 | [
[
"Demir",
"D. A.",
""
],
[
"Olive",
"Keith A.",
""
],
[
"Voloshin",
"M. B.",
""
]
] | We analyze the forward-backward asymmetry of the decays B to (pi,K) l^+ l^- with l = mu or tau in the framework of the constrained minimal supersymmetric standard model. We find that, the asymmetry is enhanced at large tan beta and depends strongly on the sign of the mu parameter. For mu > 0, the asymmetry is typically large and observable whereas for mu < 0, it changes the sign and is suppressed by an order of magnitude. Including cosmological constraints we find that the asymmetry has a maximal value of about 30 %, produced when Higgs- and gauge- induced flavor violations are of comparable size, at a value of tan beta simeq 35. The present constraints from the B-factories are too weak to constrain parameter space, and the regions excluded by them are already disfavoured by at least one of B to X_s gamma, g-2, and/or cosmology. The size of the asymmetry is mainly determined by the flavor of the final state lepton rather than the flavor of the pseudoscalar. |
hep-ph/0703024 | Howard Baer | Howard Baer, Eun-Kyung Park, Xerxes Tata and Ting T. Wang | Collider and Dark Matter Phenomenology of Models with Mirage Unification | 34 pages plus 42 EPS figures; version with high resolution figures is
at http://www.hep.fsu.edu/~baer | JHEP 0706:033,2007 | 10.1088/1126-6708/2007/06/033 | FSU-HEP-070228, UH-511-1100-07 | hep-ph | null | We examine supersymmetric models with mixed modulus-anomaly mediated SUSY
breaking (MM-AMSB) soft terms which get comparable contributions to SUSY
breaking from moduli-mediation and anomaly-mediation. The apparent (mirage)
unification of soft SUSY breaking terms at Q=mu_mir not associated with any
physical threshold is the hallmark of this scenario. The MM-AMSB structure of
soft terms arises in models of string compactification with fluxes, where the
addition of an anti-brane leads to an uplifting potential and a de Sitter
universe, as first constructed by Kachru {\it et al.}. The phenomenology mainly
depends on the relative strength of moduli- and anomaly-mediated SUSY breaking
contributions, and on the Higgs and matter field modular weights, which are
determined by the location of these fields in the extra dimensions. We
delineate the allowed parameter space for a low and high value of tan(beta),
for a wide range of modular weight choices. We calculate the neutralino relic
density and display the WMAP-allowed regions. We show the reach of the CERN LHC
and of the International Linear Collider. We discuss aspects of MM-AMSB models
for Tevatron, LHC and ILC searches, muon g-2 and b->s \gamma branching
fraction. We also calculate direct and indirect dark matter detection rates,
and show that almost all WMAP-allowed models should be accessible to a
ton-scale noble gas detector. Finally, we comment on the potential of colliders
to measure the mirage unification scale and modular weights in the difficult
case where mu_mir>>M_GUT.
| [
{
"created": "Fri, 2 Mar 2007 16:10:27 GMT",
"version": "v1"
},
{
"created": "Thu, 3 May 2007 15:52:23 GMT",
"version": "v2"
}
] | 2010-10-27 | [
[
"Baer",
"Howard",
""
],
[
"Park",
"Eun-Kyung",
""
],
[
"Tata",
"Xerxes",
""
],
[
"Wang",
"Ting T.",
""
]
] | We examine supersymmetric models with mixed modulus-anomaly mediated SUSY breaking (MM-AMSB) soft terms which get comparable contributions to SUSY breaking from moduli-mediation and anomaly-mediation. The apparent (mirage) unification of soft SUSY breaking terms at Q=mu_mir not associated with any physical threshold is the hallmark of this scenario. The MM-AMSB structure of soft terms arises in models of string compactification with fluxes, where the addition of an anti-brane leads to an uplifting potential and a de Sitter universe, as first constructed by Kachru {\it et al.}. The phenomenology mainly depends on the relative strength of moduli- and anomaly-mediated SUSY breaking contributions, and on the Higgs and matter field modular weights, which are determined by the location of these fields in the extra dimensions. We delineate the allowed parameter space for a low and high value of tan(beta), for a wide range of modular weight choices. We calculate the neutralino relic density and display the WMAP-allowed regions. We show the reach of the CERN LHC and of the International Linear Collider. We discuss aspects of MM-AMSB models for Tevatron, LHC and ILC searches, muon g-2 and b->s \gamma branching fraction. We also calculate direct and indirect dark matter detection rates, and show that almost all WMAP-allowed models should be accessible to a ton-scale noble gas detector. Finally, we comment on the potential of colliders to measure the mirage unification scale and modular weights in the difficult case where mu_mir>>M_GUT. |
1004.4692 | Ben Kain | Ben Kain and Hong Y. Ling | Vortices in Bose-Einstein Condensate Dark Matter | 10 pages, 3 figures; minor corrections, references added | Phys.Rev.D82:064042,2010 | 10.1103/PhysRevD.82.064042 | null | hep-ph astro-ph.CO astro-ph.GA | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | If dark matter in the galactic halo is composed of bosons that form a
Bose-Einstein condensate then it is likely that the rotation of the halo will
lead to the nucleation of vortices. After a review of the Gross-Pitaevskii
equation, the Thomas-Fermi approximation and vortices in general, we consider
vortices in detail. We find strong bounds for the boson mass, interaction
strength, the shape and quantity of vortices in the halo, the critical
rotational velocity for the nucleation of vortices and, in the Thomas-Fermi
regime, an exact solution for the mass density of a single, axisymmetric
vortex.
| [
{
"created": "Tue, 27 Apr 2010 01:53:51 GMT",
"version": "v1"
},
{
"created": "Thu, 30 Sep 2010 14:26:44 GMT",
"version": "v2"
}
] | 2014-11-20 | [
[
"Kain",
"Ben",
""
],
[
"Ling",
"Hong Y.",
""
]
] | If dark matter in the galactic halo is composed of bosons that form a Bose-Einstein condensate then it is likely that the rotation of the halo will lead to the nucleation of vortices. After a review of the Gross-Pitaevskii equation, the Thomas-Fermi approximation and vortices in general, we consider vortices in detail. We find strong bounds for the boson mass, interaction strength, the shape and quantity of vortices in the halo, the critical rotational velocity for the nucleation of vortices and, in the Thomas-Fermi regime, an exact solution for the mass density of a single, axisymmetric vortex. |
1804.10777 | Sergei Demidov | Mikhail Danilov, Sergey Demidov, Dmitry Gorbunov | Constraints on hidden photons produced in nuclear reactors | 5 pages, 1 figure, version accepted by PRL | Phys. Rev. Lett. 122, 041801 (2019) | 10.1103/PhysRevLett.122.041801 | INR-TH-2018-009 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | New light vector particles - hidden photons - are present in many extensions
of the Standard Model of particle physics. They can be produced in nuclear
reactors and registered by neutrino detectors. We obtain new limits on the
models with the hidden photons from an analysis of published results of the
TEXONO neutrino experiment. Accounting for oscillations between the visible and
hidden photons, we find that the neutrino experiments are generally insensitive
to the hidden photons lighter than $\sim 0.1$\,eV.
| [
{
"created": "Sat, 28 Apr 2018 09:52:07 GMT",
"version": "v1"
},
{
"created": "Tue, 22 Jan 2019 10:09:17 GMT",
"version": "v2"
}
] | 2019-02-06 | [
[
"Danilov",
"Mikhail",
""
],
[
"Demidov",
"Sergey",
""
],
[
"Gorbunov",
"Dmitry",
""
]
] | New light vector particles - hidden photons - are present in many extensions of the Standard Model of particle physics. They can be produced in nuclear reactors and registered by neutrino detectors. We obtain new limits on the models with the hidden photons from an analysis of published results of the TEXONO neutrino experiment. Accounting for oscillations between the visible and hidden photons, we find that the neutrino experiments are generally insensitive to the hidden photons lighter than $\sim 0.1$\,eV. |
2203.07729 | Tarik Akan | Tarik Akan, Elif Cincioglu, Altug Ozpineci, Adnan Tegmen | Semileptonic B_c decays to P-wave charmonia in the light-cone QCDSR | 25 pages, 9 figures, 7 tables, minor changes, typos corrected | null | 10.1016/j.nuclphysa.2023.122642 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | B_c mesons are laboratories for probing heavy quark physics. Furthermore,
they decay into charmonia and hence their decays can be used to analyze
possible exotic charmonium. In this work, the semileptonic decays of B_c mesons
into P wave charmonia are analysed using light cone QCD sum rules (LCSR). The
distributions amplitudes for the charmonia are taken from a quark model
computation. The obtained decay rates for the ground state and excited
charmonia are compared with the results found in the literature.
| [
{
"created": "Tue, 15 Mar 2022 08:49:40 GMT",
"version": "v1"
},
{
"created": "Tue, 6 Sep 2022 07:54:01 GMT",
"version": "v2"
},
{
"created": "Mon, 27 Mar 2023 11:32:53 GMT",
"version": "v3"
}
] | 2023-03-28 | [
[
"Akan",
"Tarik",
""
],
[
"Cincioglu",
"Elif",
""
],
[
"Ozpineci",
"Altug",
""
],
[
"Tegmen",
"Adnan",
""
]
] | B_c mesons are laboratories for probing heavy quark physics. Furthermore, they decay into charmonia and hence their decays can be used to analyze possible exotic charmonium. In this work, the semileptonic decays of B_c mesons into P wave charmonia are analysed using light cone QCD sum rules (LCSR). The distributions amplitudes for the charmonia are taken from a quark model computation. The obtained decay rates for the ground state and excited charmonia are compared with the results found in the literature. |
2205.01574 | Shokoufe Faraji | Shokoufe Faraji | Summary of the parallel session HR3 | null | null | null | null | hep-ph gr-qc physics.hist-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This is the summary of the parallel session entitled "Time and Philosophy in
Physics", chaired by Shokoufe Faraji at the sixteenth Marcel Grossmann Meeting.
This parallel session aimed to discuss open issues related to Time and
fundamental laws from different perspectives in a complementary point of view.
| [
{
"created": "Sun, 1 May 2022 03:46:19 GMT",
"version": "v1"
}
] | 2022-05-04 | [
[
"Faraji",
"Shokoufe",
""
]
] | This is the summary of the parallel session entitled "Time and Philosophy in Physics", chaired by Shokoufe Faraji at the sixteenth Marcel Grossmann Meeting. This parallel session aimed to discuss open issues related to Time and fundamental laws from different perspectives in a complementary point of view. |
1710.07758 | Stefan Groote Dr. | S. Groote and J.G. K\"orner | Bread and butter physics: NLO electroweak corrections to polarized top
quark decays | 10 pages, 2 figures. Contribution to the proceedings of the XVII
Workshop on High Energy Spin Physics DSPIN-17, September 11-15, Dubna
(Russia) | Journal of Physics: Conference Series 938 (2018) 012053 | 10.1088/1742-6596/938/1/012053 | MITP/17-072 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We report on the status of an ongoing calculation of the NLO electroweak
corrections to sequential polarized top quark decays $t(\uparrow) \to X_b +W^+
(\to \ell^+ +\nu_\ell)$.
| [
{
"created": "Sat, 21 Oct 2017 06:04:34 GMT",
"version": "v1"
},
{
"created": "Mon, 8 Jan 2018 12:10:05 GMT",
"version": "v2"
}
] | 2018-01-09 | [
[
"Groote",
"S.",
""
],
[
"Körner",
"J. G.",
""
]
] | We report on the status of an ongoing calculation of the NLO electroweak corrections to sequential polarized top quark decays $t(\uparrow) \to X_b +W^+ (\to \ell^+ +\nu_\ell)$. |
1310.5991 | Osamu Seto | Nobuchika Okada and Osamu Seto | Gamma ray emission in Fermi bubbles and Higgs portal dark matter | 13 pages, 4 figures, discussions and references added. typos
corrected. the final journal version | Phys. Rev. D 89, 043525 (2014) | 10.1103/PhysRevD.89.043525 | HGU-CAP 026 | hep-ph astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | It has been recently pointed out that the excess of the gamma ray spectrum in
the Fermi Bubbles at low latitude can be well explained by the annihilation of
dark matter particles. The best-fit candidate corresponds to the annihilation
of a dark matter with mass of around $62$ GeV into $b \bar{b}$ with the cross
section, $\sigma v \simeq 3.3 \times 10^{-26}$ cm$^3$/s, or the annihilation of
a dark matter with mass of around $10$ GeV into a tau lepton pair with the
cross section, $\sigma v \simeq 5.6 \times 10^{-27}$ cm$^3$/s. We point out
that the Higgs portal dark matter models are perfectly compatible with this
interpretation of the dark matter annihilation, satisfying other
phenomenological constraints. We also show that the parameter region which
reproduces the bet-fit values can be partly explored by the future direct dark
matter search at the XENON1T.
| [
{
"created": "Tue, 22 Oct 2013 17:20:13 GMT",
"version": "v1"
},
{
"created": "Tue, 11 Mar 2014 07:33:34 GMT",
"version": "v2"
}
] | 2015-06-17 | [
[
"Okada",
"Nobuchika",
""
],
[
"Seto",
"Osamu",
""
]
] | It has been recently pointed out that the excess of the gamma ray spectrum in the Fermi Bubbles at low latitude can be well explained by the annihilation of dark matter particles. The best-fit candidate corresponds to the annihilation of a dark matter with mass of around $62$ GeV into $b \bar{b}$ with the cross section, $\sigma v \simeq 3.3 \times 10^{-26}$ cm$^3$/s, or the annihilation of a dark matter with mass of around $10$ GeV into a tau lepton pair with the cross section, $\sigma v \simeq 5.6 \times 10^{-27}$ cm$^3$/s. We point out that the Higgs portal dark matter models are perfectly compatible with this interpretation of the dark matter annihilation, satisfying other phenomenological constraints. We also show that the parameter region which reproduces the bet-fit values can be partly explored by the future direct dark matter search at the XENON1T. |
hep-ph/0601031 | Bo-Qiang Ma | Nan Li, Bo-Qiang Ma | Energy scale independence of Koide's relation for quark and lepton
masses | 16 Latex pages, 2 figures, final version to appear in PRD | Phys.Rev. D73 (2006) 013009 | 10.1103/PhysRevD.73.013009 | null | hep-ph | null | Koide's mass relation of charged leptons has been extended to quarks and
neutrinos, and we prove here that this relation is independent of energy scale
in a huge energy range from $1 {GeV}$ to $2\times10^{16} {GeV}$. By using the
parameters $k_u$, $k_d$ and $k_{\nu}$ to describe the deviations of quarks and
neutrinos from the exact Koide's relation, we also check the quark-lepton
complementarity of masses such as $k_{l}+k_{d} \approx k_{\nu}+k_{u} \approx
2$, and show that it is also independent (or insensitive) of energy scale.
| [
{
"created": "Thu, 5 Jan 2006 01:17:19 GMT",
"version": "v1"
},
{
"created": "Sun, 15 Jan 2006 04:19:37 GMT",
"version": "v2"
}
] | 2009-11-11 | [
[
"Li",
"Nan",
""
],
[
"Ma",
"Bo-Qiang",
""
]
] | Koide's mass relation of charged leptons has been extended to quarks and neutrinos, and we prove here that this relation is independent of energy scale in a huge energy range from $1 {GeV}$ to $2\times10^{16} {GeV}$. By using the parameters $k_u$, $k_d$ and $k_{\nu}$ to describe the deviations of quarks and neutrinos from the exact Koide's relation, we also check the quark-lepton complementarity of masses such as $k_{l}+k_{d} \approx k_{\nu}+k_{u} \approx 2$, and show that it is also independent (or insensitive) of energy scale. |
1204.5495 | Min-Seok Seo | Jihn E. Kim, Min-Seok Seo | Mixing of axino and goldstino, and axino mass | 11 pages, 5 figures, Formulae corrected | null | 10.1016/j.nuclphysb.2012.06.018 | null | hep-ph astro-ph.CO hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Axino, related to the SUSY transformation of axion, can mix with goldstino in
principle. This case is realized when some superfields carrying nonvanishing
Peccei-Quinn charges develop both scalar VEVs and F-terms. In this case, we
present a proper definition of axion and axino. With this definition, we
present the QCD axino mass in the most general framework, including non-minimal
K\"ahler potential. The axino mass is known to have a hierarchical mass
structure depending on accidental symmetries. With only one axino, if $G_A=0$
where $G=K+\ln|W|^2$, we obtain $m_{\tilde a}=m_{3/2}$. For $G_A\ne 0$, the
axino mass depends on the details of the K\"ahler potential. In the gauge
mediation scenario, the gaugino mass is the dominant axino mass parameter.
Therefore, we can take the theoretical QCD axino mass as a free parameter in
the study of its cosmological effects, ranging from eV to multi-TeV scales,
without a present knowledge on its ultraviolet completion.
| [
{
"created": "Tue, 24 Apr 2012 21:00:20 GMT",
"version": "v1"
},
{
"created": "Mon, 2 Jul 2012 00:52:57 GMT",
"version": "v2"
}
] | 2015-06-04 | [
[
"Kim",
"Jihn E.",
""
],
[
"Seo",
"Min-Seok",
""
]
] | Axino, related to the SUSY transformation of axion, can mix with goldstino in principle. This case is realized when some superfields carrying nonvanishing Peccei-Quinn charges develop both scalar VEVs and F-terms. In this case, we present a proper definition of axion and axino. With this definition, we present the QCD axino mass in the most general framework, including non-minimal K\"ahler potential. The axino mass is known to have a hierarchical mass structure depending on accidental symmetries. With only one axino, if $G_A=0$ where $G=K+\ln|W|^2$, we obtain $m_{\tilde a}=m_{3/2}$. For $G_A\ne 0$, the axino mass depends on the details of the K\"ahler potential. In the gauge mediation scenario, the gaugino mass is the dominant axino mass parameter. Therefore, we can take the theoretical QCD axino mass as a free parameter in the study of its cosmological effects, ranging from eV to multi-TeV scales, without a present knowledge on its ultraviolet completion. |
2212.08685 | Daniel Green | Daniel Green | TASI Lectures on Cosmic Signals of Fundamental Physics | 72 pages, 14 figures, 2 tables | null | null | null | hep-ph astro-ph.CO gr-qc hep-th | http://creativecommons.org/licenses/by/4.0/ | The history of the Universe and the forces that shaped it are encoded in maps
of the cosmos. From understanding these maps, we gain insights into nature that
are inaccessible by other means. Unfortunately, the connection between
fundamental physics and cosmic observables is often left to experts (and/or
computers), making the general lessons from data obscure to many particle
theorists. Fortunately, the same basic principles that govern the interactions
of particles, like locality and causality, also control the evolution of the
Universe as a whole and the manifestation of new physics in data. By focusing
on these principles, we can understand more intuitively how the next generation
of cosmic surveys will inform our understanding of fundamental physics. In
these lectures, we will explore this relationship between theory and data
through three examples: light relics ($N_{\rm eff}$) and the cosmic microwave
background (CMB), neutrino mass and gravitational lensing of the CMB, and
primordial non-Gaussianity and the distribution of galaxies. We will discuss
both the theoretical underpinnings of these signals and the real-world
obstacles to making the measurements.
| [
{
"created": "Fri, 16 Dec 2022 19:29:09 GMT",
"version": "v1"
}
] | 2022-12-20 | [
[
"Green",
"Daniel",
""
]
] | The history of the Universe and the forces that shaped it are encoded in maps of the cosmos. From understanding these maps, we gain insights into nature that are inaccessible by other means. Unfortunately, the connection between fundamental physics and cosmic observables is often left to experts (and/or computers), making the general lessons from data obscure to many particle theorists. Fortunately, the same basic principles that govern the interactions of particles, like locality and causality, also control the evolution of the Universe as a whole and the manifestation of new physics in data. By focusing on these principles, we can understand more intuitively how the next generation of cosmic surveys will inform our understanding of fundamental physics. In these lectures, we will explore this relationship between theory and data through three examples: light relics ($N_{\rm eff}$) and the cosmic microwave background (CMB), neutrino mass and gravitational lensing of the CMB, and primordial non-Gaussianity and the distribution of galaxies. We will discuss both the theoretical underpinnings of these signals and the real-world obstacles to making the measurements. |
2405.07165 | Surender Verma Ph. D. | Labh Singh, Monal Kashav and Surender Verma | Minimal Type-I Dirac seesaw and Leptogenesis under $A_{4}$ modular
invariance | 22 pages, 8 figures | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We present a Dirac mass model based on $A_{4}$ modular symmetry within Type-I
seesaw framework. This extension of Standard Model requires three right-handed
neutrinos and three heavy Dirac fermions superfields, all singlet under
$SU(2)_{L}$ symmetry. The scalar sector is extended by the inclusion of a
$SU(2)_{L}$ singlet superfield, $\chi$. Here, the modular symmetry plays a
crucial role as the Yukawa couplings acquire modular forms, which are expressed
in terms of Dedekind eta function $\eta(\tau)$. Therefore, the Yukawa couplings
follow transformations akin to other matter fields, thereby obviating the
necessity of additional flavon fields. The acquisition of $vev$ by complex
modulus $\tau$ leads to the breaking of $A_{4}$ modular symmetry. We have
obtained predictions on neutrino oscillation parameters, for example, the model
favours ( \theta_{23} ) to be in the lower octant and normal hierarchy for
neutrino mass spectrum. Furthermore, we find that heavy Dirac fermions, in our
model, can decay to produce observed baryon asymmetry of the Universe through
Dirac leptogenesis.
| [
{
"created": "Sun, 12 May 2024 05:16:26 GMT",
"version": "v1"
}
] | 2024-05-14 | [
[
"Singh",
"Labh",
""
],
[
"Kashav",
"Monal",
""
],
[
"Verma",
"Surender",
""
]
] | We present a Dirac mass model based on $A_{4}$ modular symmetry within Type-I seesaw framework. This extension of Standard Model requires three right-handed neutrinos and three heavy Dirac fermions superfields, all singlet under $SU(2)_{L}$ symmetry. The scalar sector is extended by the inclusion of a $SU(2)_{L}$ singlet superfield, $\chi$. Here, the modular symmetry plays a crucial role as the Yukawa couplings acquire modular forms, which are expressed in terms of Dedekind eta function $\eta(\tau)$. Therefore, the Yukawa couplings follow transformations akin to other matter fields, thereby obviating the necessity of additional flavon fields. The acquisition of $vev$ by complex modulus $\tau$ leads to the breaking of $A_{4}$ modular symmetry. We have obtained predictions on neutrino oscillation parameters, for example, the model favours ( \theta_{23} ) to be in the lower octant and normal hierarchy for neutrino mass spectrum. Furthermore, we find that heavy Dirac fermions, in our model, can decay to produce observed baryon asymmetry of the Universe through Dirac leptogenesis. |
1606.06695 | Heinrich P\"as | Elke Aeikens, Heinrich P\"as, Sandip Pakvasa, Thomas J. Weiler | Big Bang Nucleosynthesis in the presence of sterile neutrinos with
altered dispersion relations | 15 pages, 7 figures | Phys. Rev. D 94, 113010 (2016) | 10.1103/PhysRevD.94.113010 | null | hep-ph astro-ph.CO nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Big Bang Nucleosynthesis imposes stringent bounds on light sterile neutrinos
mixing with the active flavors. Here we discuss how altered dispersion
relations can weaken such bounds and allow compatibility of new sterile
neutrino degrees of freedom with a successful generation of the light elements
in the early Universe.
| [
{
"created": "Tue, 21 Jun 2016 18:26:44 GMT",
"version": "v1"
}
] | 2016-12-28 | [
[
"Aeikens",
"Elke",
""
],
[
"Päs",
"Heinrich",
""
],
[
"Pakvasa",
"Sandip",
""
],
[
"Weiler",
"Thomas J.",
""
]
] | Big Bang Nucleosynthesis imposes stringent bounds on light sterile neutrinos mixing with the active flavors. Here we discuss how altered dispersion relations can weaken such bounds and allow compatibility of new sterile neutrino degrees of freedom with a successful generation of the light elements in the early Universe. |
0805.3719 | Marcelo Loewe | M. Loewe, Jorge Ruiz A. and J. C. Rojas | Thermal Behaviour of $\pi-\pi$ Scattering Lengths in the
Nambu--Jona-Lasinio model | Revtex4, 6 pages, 5 figures | Phys.Rev.D78:096007,2008 | 10.1103/PhysRevD.78.096007 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We calculate the thermal evolution of $\pi-\pi$ scattering lengths, in the
frame of the Nambu--Jona-Lasinio model. The thermal corrections were calculated
at the one loop level using Thermofield Dynamics. We present also results for
the pion thermal mass. Our procedure implies the modeling of a propagating
scalar meson as a resumation of chains of quark bubbles, which is presented
explicitly. We compare our results with previous analysis of this problem in
the frame of different theoretical approaches.
| [
{
"created": "Fri, 23 May 2008 20:57:44 GMT",
"version": "v1"
}
] | 2008-12-18 | [
[
"Loewe",
"M.",
""
],
[
"A.",
"Jorge Ruiz",
""
],
[
"Rojas",
"J. C.",
""
]
] | We calculate the thermal evolution of $\pi-\pi$ scattering lengths, in the frame of the Nambu--Jona-Lasinio model. The thermal corrections were calculated at the one loop level using Thermofield Dynamics. We present also results for the pion thermal mass. Our procedure implies the modeling of a propagating scalar meson as a resumation of chains of quark bubbles, which is presented explicitly. We compare our results with previous analysis of this problem in the frame of different theoretical approaches. |
1108.0909 | Keith Hamilton | Simone Alioli, Keith Hamilton, Emanuele Re | Practical improvements and merging of POWHEG simulations for vector
boson production | 41 pages, 19 figures. Figures updated from v1.5 to 1.6 of external
Rivet program, reference line in figs. 4,5,11 corrected. Citations added,
text unchanged | null | 10.1007/JHEP09(2011)104 | DESY 11-133, IPPP/11/43, DCPT/11/86, MCnet/11/17, LPN11-43 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this article we generalise POWHEG next-to-leading order parton shower
(NLOPS) simulations of vector boson production and vector boson production in
association with a single jet, to give matrix element corrected MENLOPS
simulations. In so doing we extend and provide, for the first time, an exact
and faithful implementation of the MENLOPS formalism in hadronic collisions. We
also consider merging the resulting event samples according to a phase space
partition defined in terms of an effective jet clustering scale. The merging
scale is restricted such that the component generated by the associated
production simulation does not impact on the NLO accuracy of inclusive vector
boson production observables. The dependence of the predictions on the
unphysical merging scale is demonstrated. Comparisons with Tevatron and LHC
data are presented.
| [
{
"created": "Wed, 3 Aug 2011 18:28:04 GMT",
"version": "v1"
},
{
"created": "Wed, 10 Aug 2011 15:58:17 GMT",
"version": "v2"
}
] | 2015-05-30 | [
[
"Alioli",
"Simone",
""
],
[
"Hamilton",
"Keith",
""
],
[
"Re",
"Emanuele",
""
]
] | In this article we generalise POWHEG next-to-leading order parton shower (NLOPS) simulations of vector boson production and vector boson production in association with a single jet, to give matrix element corrected MENLOPS simulations. In so doing we extend and provide, for the first time, an exact and faithful implementation of the MENLOPS formalism in hadronic collisions. We also consider merging the resulting event samples according to a phase space partition defined in terms of an effective jet clustering scale. The merging scale is restricted such that the component generated by the associated production simulation does not impact on the NLO accuracy of inclusive vector boson production observables. The dependence of the predictions on the unphysical merging scale is demonstrated. Comparisons with Tevatron and LHC data are presented. |
2405.16162 | Zhen-Yu Li | Zhen-Yu Li, Guo-Liang Yu, Zhi-Gang Wang, Jian-Zhong Gu | Heavy-quark dominance and fine structure of excited heavy baryons
$\Sigma_{Q}$, $\Xi '_{Q}$ and $\Omega_{Q}$ | 8 pages, 3 figures, 2 tables | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | In the framework of the relativized quark model, the calculation of
spin-orbit interactions is improved by considering the contribution from the
light quark cluster in a singly heavy baryon. It modifies the energy level
splitting of the orbital excitation significantly and causes the emergence of
fine structures for $\Sigma_{Q}$, $\Xi '_{Q}$ and $\Omega_{Q}$ baryons. Based
on this improvement, we systematically analyze the fine structures and retest
the heavy quark dominance mechanism. This mechanism is found to be violated in
the $1P$-wave states of the $\Sigma_{c}$, $\Xi '_{c}$ and $\Omega_{c}$ baryons
although it remains effective overall, which may help to understand the nature
of the heavy quarks and strong interactions. With the predicted fine
structures, we make the precise assignments of those observed heavy baryons
which once could not be accurately explained due to their close mass values.
The method used in this work is instructive and applicable for the study of
more complex exotic hadrons, such as the heavy tetraquarks and pentaquarks.
| [
{
"created": "Sat, 25 May 2024 10:10:52 GMT",
"version": "v1"
},
{
"created": "Sat, 3 Aug 2024 02:28:24 GMT",
"version": "v2"
}
] | 2024-08-06 | [
[
"Li",
"Zhen-Yu",
""
],
[
"Yu",
"Guo-Liang",
""
],
[
"Wang",
"Zhi-Gang",
""
],
[
"Gu",
"Jian-Zhong",
""
]
] | In the framework of the relativized quark model, the calculation of spin-orbit interactions is improved by considering the contribution from the light quark cluster in a singly heavy baryon. It modifies the energy level splitting of the orbital excitation significantly and causes the emergence of fine structures for $\Sigma_{Q}$, $\Xi '_{Q}$ and $\Omega_{Q}$ baryons. Based on this improvement, we systematically analyze the fine structures and retest the heavy quark dominance mechanism. This mechanism is found to be violated in the $1P$-wave states of the $\Sigma_{c}$, $\Xi '_{c}$ and $\Omega_{c}$ baryons although it remains effective overall, which may help to understand the nature of the heavy quarks and strong interactions. With the predicted fine structures, we make the precise assignments of those observed heavy baryons which once could not be accurately explained due to their close mass values. The method used in this work is instructive and applicable for the study of more complex exotic hadrons, such as the heavy tetraquarks and pentaquarks. |
2405.06509 | Julien Froustey | Julien Froustey, Cyril Pitrou | Constraints on primordial lepton asymmetries with full neutrino
transport | 22 pages, 16 figures. Datasets available at
[https://doi.org/10.5281/zenodo.11123226] | null | null | N3AS-24-015 | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Primordial neutrino-antineutrino asymmetries can be constrained through
big-bang nucleosynthesis (BBN) relic abundances and cosmic microwave background
(CMB) anisotropies, both observables being sensitive to neutrino properties.
The latter constraint, which is due to gravitational effects from all neutrino
flavors, is very minute since it is at least quadratic in the asymmetries. On
the contrary, the constraints from primordial abundances presently dominate,
although these abundances are almost only sensitive to the electron flavor
asymmetry. It is generally assumed that neutrino asymmetries are sufficiently
averaged by flavor oscillations prior to BBN, which allows to constrain a
common primordial neutrino asymmetry at the epoch of BBN. This simplified
approach suffers two caveats that we deal with in this article, combining a
neutrino evolution code and BBN calculation throughout the MeV era. First,
flavor "equilibration" is not true in general, therefore an accurate dynamical
evolution of asymmetries is needed to connect experimental observables to the
primordial asymmetries. Second, the approximate averaging of asymmetries
through flavor oscillations is associated to a reheating of the primordial
plasma. It is therefore crucial to correctly describe the interplay between
flavor equilibration and neutrino decoupling, as an energy redistribution prior
to decoupling does not significantly alter the final effective number of
neutrino species' value. Overall, we find that the space of allowed initial
asymmetries is generically unbound when using currently available primordial
abundances and CMB measurements. We forecast constraints using future CMB
experiment capabilities, which should reverse this experimental misfortune.
| [
{
"created": "Fri, 10 May 2024 14:42:38 GMT",
"version": "v1"
}
] | 2024-05-13 | [
[
"Froustey",
"Julien",
""
],
[
"Pitrou",
"Cyril",
""
]
] | Primordial neutrino-antineutrino asymmetries can be constrained through big-bang nucleosynthesis (BBN) relic abundances and cosmic microwave background (CMB) anisotropies, both observables being sensitive to neutrino properties. The latter constraint, which is due to gravitational effects from all neutrino flavors, is very minute since it is at least quadratic in the asymmetries. On the contrary, the constraints from primordial abundances presently dominate, although these abundances are almost only sensitive to the electron flavor asymmetry. It is generally assumed that neutrino asymmetries are sufficiently averaged by flavor oscillations prior to BBN, which allows to constrain a common primordial neutrino asymmetry at the epoch of BBN. This simplified approach suffers two caveats that we deal with in this article, combining a neutrino evolution code and BBN calculation throughout the MeV era. First, flavor "equilibration" is not true in general, therefore an accurate dynamical evolution of asymmetries is needed to connect experimental observables to the primordial asymmetries. Second, the approximate averaging of asymmetries through flavor oscillations is associated to a reheating of the primordial plasma. It is therefore crucial to correctly describe the interplay between flavor equilibration and neutrino decoupling, as an energy redistribution prior to decoupling does not significantly alter the final effective number of neutrino species' value. Overall, we find that the space of allowed initial asymmetries is generically unbound when using currently available primordial abundances and CMB measurements. We forecast constraints using future CMB experiment capabilities, which should reverse this experimental misfortune. |
hep-ph/0212382 | Alan Kostelecky | Alan Kostelecky and Austin Pickering | Vacuum Photon Splitting in Lorentz-Violating Quantum Electrodynamics | 4 pages, minor wording changes, references added, accepted in
Physical Review Letters | Phys.Rev.Lett.91:031801,2003 | 10.1103/PhysRevLett.91.031801 | IUHET 453, December 2002 | hep-ph hep-th | null | Radiative corrections arising from Lorentz violation in the fermion sector
induce a nonzero amplitude for vacuum photon splitting. At one loop, the
on-shell amplitude acquires both CPT-even and CPT-odd contributions forbidden
in conventional electrodynamics.
| [
{
"created": "Sat, 28 Dec 2002 16:20:44 GMT",
"version": "v1"
},
{
"created": "Fri, 20 Jun 2003 20:12:36 GMT",
"version": "v2"
}
] | 2009-09-25 | [
[
"Kostelecky",
"Alan",
""
],
[
"Pickering",
"Austin",
""
]
] | Radiative corrections arising from Lorentz violation in the fermion sector induce a nonzero amplitude for vacuum photon splitting. At one loop, the on-shell amplitude acquires both CPT-even and CPT-odd contributions forbidden in conventional electrodynamics. |
hep-ph/9406337 | null | Stephen Mrenna and G.L. Kane | Possible Detection of a Higgs Boson at Higher Luminosity Hadron
Colliders | 20 REVTEX pages plus 3 figures using psfig.sty, CIT 68--1938 | null | null | null | hep-ph | null | We have examined how a Standard Model or Supersymmetric Higgs boson h might
be detected at possible hadron colliders. The channels W(to ell nu)h(to b b~),
Z(to ell ell~)h(to b b~) and W/Z(to jets)h(to tau+ tau-) are most useful. The
results imply that h with mass M_h can be detected or excluded for M_h between
about 80--130 GeV at any hadron collider with energy greater or similar to 2
TeV and an integrated luminosity greater or similar to 10 fb^{-1}; high
luminosity is the essential requirement. We comment on measuring $h$ couplings
and branching ratios.
| [
{
"created": "Sat, 18 Jun 1994 00:34:30 GMT",
"version": "v1"
}
] | 2016-09-01 | [
[
"Mrenna",
"Stephen",
""
],
[
"Kane",
"G. L.",
""
]
] | We have examined how a Standard Model or Supersymmetric Higgs boson h might be detected at possible hadron colliders. The channels W(to ell nu)h(to b b~), Z(to ell ell~)h(to b b~) and W/Z(to jets)h(to tau+ tau-) are most useful. The results imply that h with mass M_h can be detected or excluded for M_h between about 80--130 GeV at any hadron collider with energy greater or similar to 2 TeV and an integrated luminosity greater or similar to 10 fb^{-1}; high luminosity is the essential requirement. We comment on measuring $h$ couplings and branching ratios. |
hep-ph/9702331 | Hoang | A.H. Hoang (University of California, San Diego) | The Vacuum Polarization Function to O(alpha^2) Accuracy Near Threshold
and Darwin Corrections | 26 pages, latex, five ps figures included | Phys. Rev. D 57, 1615 (1998) | 10.1103/PhysRevD.57.1615 | UCSD/PTH 97-04 | hep-ph | null | The QED vacuum polarization function is calculated to O(alpha^2)
(next-to-leading order) accuracy in the threshold regime by using the concept
of effective field theories to resum diagrams with the instantaneous Coulomb
exchange of longitudinally polarized photons. It is shown that the O(alpha^2)
contributions are of order alpha^2 in size rather than alpha^2/Pi^2. The vacuum
polarization contributions to the O(alpha^6) hyperfine splitting of the
positronium ground state are recalculated and differences with an older
calculation are pointed out. The results are used to determine O(C_F^2
alpha_s^2) (next-to-next-to-leading order) Darwin corrections to heavy
quark-antiquark bound state l=0 wave functions at the origin and to the heavy
quark-antiquark production cross section in e^+e^- collisions in the threshold
region. The absolute value of the corrections amounts to 10%-20% and 17%-34% in
the modulus squared of the ground state wave functions at the origin for the
$b\bar b$ and $c\bar c$ systems, respectively. In the case of the $t\bar t$
production cross section in the threshold region the absolute value of the
corrections is between 2% and 6% around the 1S peak and between 1% and 2% for
higher energies. A critical comment on recent QCD sum rule calculations for the
$\Upsilon$ system is made.
| [
{
"created": "Thu, 13 Feb 1997 21:08:35 GMT",
"version": "v1"
}
] | 2016-08-25 | [
[
"Hoang",
"A. H.",
"",
"University of California, San Diego"
]
] | The QED vacuum polarization function is calculated to O(alpha^2) (next-to-leading order) accuracy in the threshold regime by using the concept of effective field theories to resum diagrams with the instantaneous Coulomb exchange of longitudinally polarized photons. It is shown that the O(alpha^2) contributions are of order alpha^2 in size rather than alpha^2/Pi^2. The vacuum polarization contributions to the O(alpha^6) hyperfine splitting of the positronium ground state are recalculated and differences with an older calculation are pointed out. The results are used to determine O(C_F^2 alpha_s^2) (next-to-next-to-leading order) Darwin corrections to heavy quark-antiquark bound state l=0 wave functions at the origin and to the heavy quark-antiquark production cross section in e^+e^- collisions in the threshold region. The absolute value of the corrections amounts to 10%-20% and 17%-34% in the modulus squared of the ground state wave functions at the origin for the $b\bar b$ and $c\bar c$ systems, respectively. In the case of the $t\bar t$ production cross section in the threshold region the absolute value of the corrections is between 2% and 6% around the 1S peak and between 1% and 2% for higher energies. A critical comment on recent QCD sum rule calculations for the $\Upsilon$ system is made. |
1502.07987 | Peter Millington | P. S. Bhupal Dev, Peter Millington, Apostolos Pilaftsis, Daniele
Teresi | Flavour effects in Resonant Leptogenesis from semi-classical and
Kadanoff-Baym approaches | 15 pages, 4 figures; one reference added; contribution to the
Proceedings of DISCRETE 2014, London | 2015 J. Phys.: Conf. Ser. 631 012087 | 10.1088/1742-6596/631/1/012087 | MAN/HEP/2015/01, TUM-HEP-982-15 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Flavour effects play an important role in the statistical evolution of
particle number densities in several particle physics phenomena. We present a
fully flavour-covariant formalism for transport phenomena, in order to
consistently capture all flavour effects in the system. We explicitly study the
scenario of Resonant Leptogenesis (RL), and show that flavour covariance
requires one to consider generically off-diagonal number densities, rank-4 rate
tensors in flavour space, and non-trivial generalization of the discrete
symmetries C, P and T. The flavour-covariant transport equations, obtained in
our semi-classical framework, describe the effects of three relevant physical
phenomena: coherent heavy-neutrino oscillations, quantum decoherence in the
charged-lepton sector, and resonant CP violation due to heavy-neutrino mixing.
We show quantitatively that the final asymmetry is enhanced by up to an order
of magnitude, for electroweak-scale heavy neutrinos, as compared to that
obtained from flavour-diagonal or partially flavour off-diagonal equations. A
full field-theoretic treatment in the weakly-resonant regime, based on the
Kadanoff-Baym (KB) equations, confirms that heavy-neutrino oscillations and
mixing are two distinct phenomena, and reproduces the results obtained in our
semi-classical framework. Finally, we show that the quasi-particle ansaetze,
often employed in KB approaches to RL, discard the phenomenon of mixing,
capturing only oscillations and leading to an underestimate of the final
asymmetry by a factor of order 2.
| [
{
"created": "Fri, 27 Feb 2015 17:56:04 GMT",
"version": "v1"
},
{
"created": "Fri, 24 Apr 2015 16:30:23 GMT",
"version": "v2"
},
{
"created": "Wed, 26 Aug 2015 06:41:58 GMT",
"version": "v3"
}
] | 2015-08-27 | [
[
"Dev",
"P. S. Bhupal",
""
],
[
"Millington",
"Peter",
""
],
[
"Pilaftsis",
"Apostolos",
""
],
[
"Teresi",
"Daniele",
""
]
] | Flavour effects play an important role in the statistical evolution of particle number densities in several particle physics phenomena. We present a fully flavour-covariant formalism for transport phenomena, in order to consistently capture all flavour effects in the system. We explicitly study the scenario of Resonant Leptogenesis (RL), and show that flavour covariance requires one to consider generically off-diagonal number densities, rank-4 rate tensors in flavour space, and non-trivial generalization of the discrete symmetries C, P and T. The flavour-covariant transport equations, obtained in our semi-classical framework, describe the effects of three relevant physical phenomena: coherent heavy-neutrino oscillations, quantum decoherence in the charged-lepton sector, and resonant CP violation due to heavy-neutrino mixing. We show quantitatively that the final asymmetry is enhanced by up to an order of magnitude, for electroweak-scale heavy neutrinos, as compared to that obtained from flavour-diagonal or partially flavour off-diagonal equations. A full field-theoretic treatment in the weakly-resonant regime, based on the Kadanoff-Baym (KB) equations, confirms that heavy-neutrino oscillations and mixing are two distinct phenomena, and reproduces the results obtained in our semi-classical framework. Finally, we show that the quasi-particle ansaetze, often employed in KB approaches to RL, discard the phenomenon of mixing, capturing only oscillations and leading to an underestimate of the final asymmetry by a factor of order 2. |
hep-ph/9508202 | Alexander Krasnitz | J. Ambj{\o}rn and A. Krasnitz | The classical sphaleron transition rate exists and is equal to
$1.1(\alpha_w T)^4$ | 12 pages, plain LaTeX, figures part of the LaTeX source, minor errors
corrected, acknowledgment added, to be published in Phys. Lett. B | Phys.Lett. B362 (1995) 97-104 | 10.1016/0370-2693(95)01157-L | NBI-HE-95-23 | hep-ph hep-lat hep-th | null | Results of a large scale numerical simulation show that the high temperature
Chern-Simons number diffusion rate in the electroweak theory has a classical
limit $\Gamma = \kappa (\alpha_w T)^4$, where $\kappa = 1.09\pm 0.04$ and
$\alpha_w$ is the weak fine structure constant.
| [
{
"created": "Tue, 1 Aug 1995 11:42:15 GMT",
"version": "v1"
},
{
"created": "Tue, 26 Sep 1995 12:52:08 GMT",
"version": "v2"
}
] | 2009-10-28 | [
[
"Ambjørn",
"J.",
""
],
[
"Krasnitz",
"A.",
""
]
] | Results of a large scale numerical simulation show that the high temperature Chern-Simons number diffusion rate in the electroweak theory has a classical limit $\Gamma = \kappa (\alpha_w T)^4$, where $\kappa = 1.09\pm 0.04$ and $\alpha_w$ is the weak fine structure constant. |
hep-ph/0609232 | Mikolaj Misiak | M.Misiak, H.M.Asatrian, K.Bieri, M.Czakon, A.Czarnecki, T.Ewerth,
A.Ferroglia, P.Gambino, M.Gorbahn, C.Greub, U.Haisch, A.Hovhannisyan,
T.Hurth, A.Mitov, V.Poghosyan, M.Slusarczyk and M.Steinhauser | Estimate of BR(B -> X_s gamma) at O(alpha_s^2) | 4 pages, 4 figures. Version accepted by the PRL. Words disallowed by
the journal removed from the title. References updated and a note added | Phys.Rev.Lett.98:022002,2007 | 10.1103/PhysRevLett.98.022002 | IFT-18/2006, CERN-PH-TH/2006-184, YERPHI-1608(6), Freiburg-THEP
06/13, DFTT-20/2006, SFB/CPP-06-45, TTP06-26, ZU-TH 22/06, SLAC-PUB-12117,
DESY 06-168 | hep-ph | null | Combining our results for various O(alpha_s^2) corrections to the weak
radiative B-meson decay, we are able to present the first estimate of the
branching ratio at the next-to-next-to-leading order in QCD. We find BR(B ->
X_s gamma) = (3.15 +_ 0.23) x 10^-4 for E_gamma > 1.6 GeV in the B-meson rest
frame. The four types of uncertainties: non-perturbative (5%), parametric (3%),
higher-order (3%) and m_c-interpolation ambiguity (3%) have been added in
quadrature to obtain the total error.
| [
{
"created": "Fri, 22 Sep 2006 17:36:46 GMT",
"version": "v1"
},
{
"created": "Sun, 31 Dec 2006 19:05:03 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Misiak",
"M.",
""
],
[
"Asatrian",
"H. M.",
""
],
[
"Bieri",
"K.",
""
],
[
"Czakon",
"M.",
""
],
[
"Czarnecki",
"A.",
""
],
[
"Ewerth",
"T.",
""
],
[
"Ferroglia",
"A.",
""
],
[
"Gambino",
"P.",... | Combining our results for various O(alpha_s^2) corrections to the weak radiative B-meson decay, we are able to present the first estimate of the branching ratio at the next-to-next-to-leading order in QCD. We find BR(B -> X_s gamma) = (3.15 +_ 0.23) x 10^-4 for E_gamma > 1.6 GeV in the B-meson rest frame. The four types of uncertainties: non-perturbative (5%), parametric (3%), higher-order (3%) and m_c-interpolation ambiguity (3%) have been added in quadrature to obtain the total error. |
1209.6375 | Gustavo Marques Tavares | Christian Gross, Gustavo Marques Tavares, Martin Schmaltz and
Christian Spethmann | Light axigluon explanation of the Tevatron ttbar asymmetry and multijet
signals at the LHC | 35 pages, 15 figures; references added | null | 10.1103/PhysRevD.87.014004 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The ttbar asymmetry measured at the Tevatron continues to disagree with
Standard Model predictions at the 3 sigma level. We update the status of the
phenomenological light axigluon model in explaining the asymmetry data, taking
into account constraints from the charge asymmetry at the LHC and the ttbar
cross section at both Tevatron and LHC. We find that an axigluon with a mass
between 100 and 400 GeV provides an excellent fit to the data. Recent searches
by ATLAS and CMS for pair production of heavy resonances which decay to dijets
rule out axigluons with large branching fractions to dijets. However axigluons
which predominantly decay to multijets via intermediate resonances are still a
possibility. We outline four distinct scenarios which cover the most important
decay topologies and discuss how one might exclude or discover axigluons as
multijet resonances at the LHC. MadGraph implementations for each of the
scenarios are provided.
| [
{
"created": "Thu, 27 Sep 2012 20:57:12 GMT",
"version": "v1"
},
{
"created": "Wed, 17 Oct 2012 19:38:15 GMT",
"version": "v2"
}
] | 2013-05-30 | [
[
"Gross",
"Christian",
""
],
[
"Tavares",
"Gustavo Marques",
""
],
[
"Schmaltz",
"Martin",
""
],
[
"Spethmann",
"Christian",
""
]
] | The ttbar asymmetry measured at the Tevatron continues to disagree with Standard Model predictions at the 3 sigma level. We update the status of the phenomenological light axigluon model in explaining the asymmetry data, taking into account constraints from the charge asymmetry at the LHC and the ttbar cross section at both Tevatron and LHC. We find that an axigluon with a mass between 100 and 400 GeV provides an excellent fit to the data. Recent searches by ATLAS and CMS for pair production of heavy resonances which decay to dijets rule out axigluons with large branching fractions to dijets. However axigluons which predominantly decay to multijets via intermediate resonances are still a possibility. We outline four distinct scenarios which cover the most important decay topologies and discuss how one might exclude or discover axigluons as multijet resonances at the LHC. MadGraph implementations for each of the scenarios are provided. |
1502.07260 | Yithsbey Giraldo | Yithsbey Giraldo | Reply to "Comment on "Texture Zeros and WB Transformations in the Quark
Sector of the Standard Model" | null | Phys. Rev. D 91, 038302 (2015) | 10.1103/PhysRevD.91.038302 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We respond to the comments of S. Sharma et al. [Phys. Rev. D 91, 038301
(2015)] on my recent paper, Y. Giraldo [Phys. Rev. D 86, 093021 (2012)]. In
their comments, they begin discussing a particular class of five-zero texture
non-Fritzsch-like quark mass matrix, which was proposed by me, and questioning
its validity. Then, they put in doubt the phases included in the unitary
matrices used for diagonalizing the quark mass matrices, from which they claim
that the CP violating parameter $\epsilon_k$ obtained does not agree with the
experimental value. Because of these comments, finally, they recommend being
careful while analyzing the implications of Weak Basis transformations on
textures. Other minor points are also discussed by them.
In the following, I will show that the mentioned five-zero texture
non-Fritzsch-like quark mass matrices is completely valid and generates all the
physical quantities involved, including the CP violating parameter
$\epsilon_k$, for which is required the inclusion of phases in the unitary
matrices used for diagonalizing the quark mass matrices in order to put the CKM
matrix in standard form. These phases can be rotated away so they do not have
any physical meaning. Finally, the relevance of the weak basis transformation
is appreciated: which is {\it complete} and facilitates calculations,
especially of textures zeros.
| [
{
"created": "Wed, 25 Feb 2015 17:19:45 GMT",
"version": "v1"
}
] | 2015-06-24 | [
[
"Giraldo",
"Yithsbey",
""
]
] | We respond to the comments of S. Sharma et al. [Phys. Rev. D 91, 038301 (2015)] on my recent paper, Y. Giraldo [Phys. Rev. D 86, 093021 (2012)]. In their comments, they begin discussing a particular class of five-zero texture non-Fritzsch-like quark mass matrix, which was proposed by me, and questioning its validity. Then, they put in doubt the phases included in the unitary matrices used for diagonalizing the quark mass matrices, from which they claim that the CP violating parameter $\epsilon_k$ obtained does not agree with the experimental value. Because of these comments, finally, they recommend being careful while analyzing the implications of Weak Basis transformations on textures. Other minor points are also discussed by them. In the following, I will show that the mentioned five-zero texture non-Fritzsch-like quark mass matrices is completely valid and generates all the physical quantities involved, including the CP violating parameter $\epsilon_k$, for which is required the inclusion of phases in the unitary matrices used for diagonalizing the quark mass matrices in order to put the CKM matrix in standard form. These phases can be rotated away so they do not have any physical meaning. Finally, the relevance of the weak basis transformation is appreciated: which is {\it complete} and facilitates calculations, especially of textures zeros. |
hep-ph/0403095 | Josep F. Oliver | Josep F. Oliver | Aspects of universal extra dimensional models and their latticized
versions | Ph.D. Thesis, 94 pages | null | null | null | hep-ph | null | In this work some aspects of models with universal extra dimensions are
studied. In particular, in the case of models with one universal extra
dimension their phenomenology is investigated and used to extract bounds on the
size of the extra dimension. In addition, the phenomenology of their latticized
counterparts is also investigated. The running of the gauge coupling constants
in models with an arbitrary number of universal extra dimensions is revisited.
The possible reliable determination of the power corrections that appear is
studied. Finally, a model with one non-universal extra dimension is presented
to compare the results in these kind of scenarios with the universal ones.
| [
{
"created": "Tue, 9 Mar 2004 09:38:20 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Oliver",
"Josep F.",
""
]
] | In this work some aspects of models with universal extra dimensions are studied. In particular, in the case of models with one universal extra dimension their phenomenology is investigated and used to extract bounds on the size of the extra dimension. In addition, the phenomenology of their latticized counterparts is also investigated. The running of the gauge coupling constants in models with an arbitrary number of universal extra dimensions is revisited. The possible reliable determination of the power corrections that appear is studied. Finally, a model with one non-universal extra dimension is presented to compare the results in these kind of scenarios with the universal ones. |
1112.0626 | Stanley J. Brodsky | Stanley J. Brodsky | Transversity from First Principles in QCD | Presented at Transversity 2011: The 3rd International Workshop On
Transverse Polarization Phenomena In Hard Scattering, 29 August - 2 September
2011, Veli Lozinj, Croatia | null | 10.1393/ncc/i2012-11180-2 | SLAC-PUB-14704 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Transversity observables, such as the T-odd single-spin asymmetry measured in
deep inelastic lepton scattering on polarized protons, and the distributions
which are measured in deeply virtual Compton scattering provide important
constraints on the fundamental quark and gluon structure of the proton. In this
talk I discuss the challenge of computing these observables from first
principles; i.e., quantum chromodynamics, itself. A key step is the
determination of the frame-independent light-front wavefunctions (LFWFs) of
hadrons -- the QCD eigensolutions which are analogs of the Schrodinger
wavefunctions of atomic physics. The lensing effects of initial-state and
final-state interactions, acting on LFWFs with different orbital angular
momentum, lead to the T-odd transversity observables such as the Sivers,
Collins, and Boer-Mulders distributions. The lensing effect also leads to
leading-twist phenomena which break leading-twist factorization, such as the
breakdown of the Lam-Tung relation in Drell-Yan reactions. A similar
rescattering mechanism also leads to diffractive deep inelastic scattering, as
well as nuclear shadowing and non-universal antishadowing. It is thus important
to distinguish "static" structure functions, the probability distributions
computed from the target hadron's light-front wavefunctions, versus "dynamical"
structure functions which include the effects of initial- and final-state
rescattering. I also discuss related effects, such as the J=0 fixed pole
contribution which appears in the real part of the virtual Compton amplitude.
AdS/QCD, together with "Light-Front Holography", provides a simple
Lorentz-invariant color-confining approximation to QCD which is successful in
accounting for light-quark meson and baryon spectroscopy as well as hadronic
LFWFs.
| [
{
"created": "Sat, 3 Dec 2011 07:21:37 GMT",
"version": "v1"
},
{
"created": "Wed, 7 Dec 2011 06:29:27 GMT",
"version": "v2"
}
] | 2022-03-02 | [
[
"Brodsky",
"Stanley J.",
""
]
] | Transversity observables, such as the T-odd single-spin asymmetry measured in deep inelastic lepton scattering on polarized protons, and the distributions which are measured in deeply virtual Compton scattering provide important constraints on the fundamental quark and gluon structure of the proton. In this talk I discuss the challenge of computing these observables from first principles; i.e., quantum chromodynamics, itself. A key step is the determination of the frame-independent light-front wavefunctions (LFWFs) of hadrons -- the QCD eigensolutions which are analogs of the Schrodinger wavefunctions of atomic physics. The lensing effects of initial-state and final-state interactions, acting on LFWFs with different orbital angular momentum, lead to the T-odd transversity observables such as the Sivers, Collins, and Boer-Mulders distributions. The lensing effect also leads to leading-twist phenomena which break leading-twist factorization, such as the breakdown of the Lam-Tung relation in Drell-Yan reactions. A similar rescattering mechanism also leads to diffractive deep inelastic scattering, as well as nuclear shadowing and non-universal antishadowing. It is thus important to distinguish "static" structure functions, the probability distributions computed from the target hadron's light-front wavefunctions, versus "dynamical" structure functions which include the effects of initial- and final-state rescattering. I also discuss related effects, such as the J=0 fixed pole contribution which appears in the real part of the virtual Compton amplitude. AdS/QCD, together with "Light-Front Holography", provides a simple Lorentz-invariant color-confining approximation to QCD which is successful in accounting for light-quark meson and baryon spectroscopy as well as hadronic LFWFs. |
0905.3329 | Dmitri Antonov | Dmitri Antonov | Shear viscosity of the gluon plasma in the stochastic-vacuum approach | 19 pages, 4 figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Shear viscosity of the gluon plasma in SU(3) YM theory is calculated
nonperturbatively, within the stochastic vacuum model. The result for the ratio
of the shear viscosity to the entropy density, proportional to the squared
chromo-magnetic gluon condensate and the fifth power of the correlation length
of the chromo-magnetic vacuum, falls off with the increase of temperature. At
temperatures larger than the deconfinement critical temperature by a factor of
2, this fall-off is determined by the sixth power of the temperature-dependent
strong-coupling constant and yields an asymptotic approach to the conjectured
lower bound of 1/(4\pi), achievable in {\cal N}=4 SYM theory. As a by-product
of the calculation, we find a particular form of the two-point correlation
function of gluonic field strengths, which is the only one consistent with the
Lorentzian shape of the shear-viscosity spectral function.
| [
{
"created": "Wed, 20 May 2009 15:02:17 GMT",
"version": "v1"
}
] | 2009-05-21 | [
[
"Antonov",
"Dmitri",
""
]
] | Shear viscosity of the gluon plasma in SU(3) YM theory is calculated nonperturbatively, within the stochastic vacuum model. The result for the ratio of the shear viscosity to the entropy density, proportional to the squared chromo-magnetic gluon condensate and the fifth power of the correlation length of the chromo-magnetic vacuum, falls off with the increase of temperature. At temperatures larger than the deconfinement critical temperature by a factor of 2, this fall-off is determined by the sixth power of the temperature-dependent strong-coupling constant and yields an asymptotic approach to the conjectured lower bound of 1/(4\pi), achievable in {\cal N}=4 SYM theory. As a by-product of the calculation, we find a particular form of the two-point correlation function of gluonic field strengths, which is the only one consistent with the Lorentzian shape of the shear-viscosity spectral function. |
1301.5167 | Luis Ibanez | Luis E. Ibanez and Irene Valenzuela | The Higgs Mass as a Signature of Heavy SUSY | 25 pages, 7 figures. Slight changes in figures. Conclusions unchanged | null | 10.1007/JHEP05(2013)064 | IFT-UAM/CSIC-13-008; FTUAM-13-126 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We compute the mass of the Higgs particle in a scheme in which SUSY is broken
at a large scale M_{SS} well above the electroweak scale M_{EW}. Below M_{SS}
one assumes one is just left with the SM with a fine-tuned Higgs potential.
Under standard unification assumptions one can compute the mass of the Higgs
particle as a function of the SUSY breaking scale M_{SS}. For M_{SS} > 10^{10}
GeV one obtains m_H=126 \pm 3 GeV, consistent with CMS and ATLAS results. For
lower values of M_{SS} the values of the Higgs mass tend to those of a
fine-tuned MSSM with m_H < 130 GeV. These results support the idea that the
measured value of the Higgs mass at LHC may be considered as indirect evidence
for the existence of SUSY at some (not necessarily low) mass scale.
| [
{
"created": "Tue, 22 Jan 2013 12:25:38 GMT",
"version": "v1"
},
{
"created": "Wed, 20 Feb 2013 10:56:03 GMT",
"version": "v2"
},
{
"created": "Fri, 1 Mar 2013 09:18:07 GMT",
"version": "v3"
}
] | 2015-06-12 | [
[
"Ibanez",
"Luis E.",
""
],
[
"Valenzuela",
"Irene",
""
]
] | We compute the mass of the Higgs particle in a scheme in which SUSY is broken at a large scale M_{SS} well above the electroweak scale M_{EW}. Below M_{SS} one assumes one is just left with the SM with a fine-tuned Higgs potential. Under standard unification assumptions one can compute the mass of the Higgs particle as a function of the SUSY breaking scale M_{SS}. For M_{SS} > 10^{10} GeV one obtains m_H=126 \pm 3 GeV, consistent with CMS and ATLAS results. For lower values of M_{SS} the values of the Higgs mass tend to those of a fine-tuned MSSM with m_H < 130 GeV. These results support the idea that the measured value of the Higgs mass at LHC may be considered as indirect evidence for the existence of SUSY at some (not necessarily low) mass scale. |
1904.11249 | Antonio Capolupo Dr | A. Capolupo and S.M. Giampaolo | Neutrino nature, total and geometric phase | 5 pages, 2 figures, presented at 9th International Conference
DICE2018: Spacetime - Matter - Quantum Mechanics : From discrete structures
and dynamics to top-down causation | Physics Letters B Volume 792, 10 May 2019, Pages 298-303 | 10.1088/1742-6596/1275/1/012053 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the total and the geometric phase associated with neutrino mixing
and we show that the phases produced by the neutrino oscillations have
different values depending on the representation of the mixing matrix and on
the neutrino nature. Therefore the phases represent a possible probe to
distinguish between Dirac and Majorana neutrinos.
| [
{
"created": "Thu, 25 Apr 2019 10:16:36 GMT",
"version": "v1"
}
] | 2020-01-08 | [
[
"Capolupo",
"A.",
""
],
[
"Giampaolo",
"S. M.",
""
]
] | We study the total and the geometric phase associated with neutrino mixing and we show that the phases produced by the neutrino oscillations have different values depending on the representation of the mixing matrix and on the neutrino nature. Therefore the phases represent a possible probe to distinguish between Dirac and Majorana neutrinos. |
hep-ph/0406220 | Sergey Kulagin | S.A. Kulagin (Institute for Nuclear Research, Moscow) | On the Paschos-Wolfenstein Relationship for Nuclei | 6 pages, talk at XXXIX Recontres de Moriond "Electroweak Interactions
and Unified Theories", La Thuile, March 21-28, 2004 | null | null | null | hep-ph | null | Nuclear effects and QCD perturbative corrections to the Paschos-Wolfenstein
relationship are discussed. We argue that perturbative corrections largely
cancel out in this relationship for total cross sections while the neutron
excess correction in heavy nuclei is enhanced by Fermi motion and nuclear
binding effects. These observations are discussed in the context of NuTeV
measurement of the Weinberg mixing angle.
| [
{
"created": "Mon, 21 Jun 2004 11:58:26 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Kulagin",
"S. A.",
"",
"Institute for Nuclear Research, Moscow"
]
] | Nuclear effects and QCD perturbative corrections to the Paschos-Wolfenstein relationship are discussed. We argue that perturbative corrections largely cancel out in this relationship for total cross sections while the neutron excess correction in heavy nuclei is enhanced by Fermi motion and nuclear binding effects. These observations are discussed in the context of NuTeV measurement of the Weinberg mixing angle. |
1104.5613 | Rikkert Frederix | Rikkert Frederix, Stefano Frixione, Valentin Hirschi, Fabio Maltoni,
Roberto Pittau, Paolo Torrielli | Scalar and pseudoscalar Higgs production in association with a
top-antitop pair | 15 pages, 8 figures, published version. (2 references added, improved
description of the decay of the top and Higgs bosons) | Phys.Lett.B701:427-433,2011 | 10.1016/j.physletb.2011.06.012 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the calculation of scalar and pseudoscalar Higgs production in
association with a top-antitop pair to the next-to-leading order (NLO) accuracy
in QCD, interfaced with parton showers according to the MC@NLO formalism. We
apply our results to the cases of light and very light Higgs boson production
at the LHC, giving results for total rates as well as for sample differential
distributions, relevant to the Higgs, to the top quarks, and to their decay
products. This work constitutes the first phenomenological application of
aMC@NLO, a fully automated approach to complete event generation at NLO in QCD.
| [
{
"created": "Fri, 29 Apr 2011 12:32:25 GMT",
"version": "v1"
},
{
"created": "Fri, 17 Jun 2011 22:03:58 GMT",
"version": "v2"
}
] | 2011-07-06 | [
[
"Frederix",
"Rikkert",
""
],
[
"Frixione",
"Stefano",
""
],
[
"Hirschi",
"Valentin",
""
],
[
"Maltoni",
"Fabio",
""
],
[
"Pittau",
"Roberto",
""
],
[
"Torrielli",
"Paolo",
""
]
] | We present the calculation of scalar and pseudoscalar Higgs production in association with a top-antitop pair to the next-to-leading order (NLO) accuracy in QCD, interfaced with parton showers according to the MC@NLO formalism. We apply our results to the cases of light and very light Higgs boson production at the LHC, giving results for total rates as well as for sample differential distributions, relevant to the Higgs, to the top quarks, and to their decay products. This work constitutes the first phenomenological application of aMC@NLO, a fully automated approach to complete event generation at NLO in QCD. |
0806.4503 | Piet Mulders J | P.J. Mulders | Single spin asymmetries and gluonic pole matrix elements | 4 pages, 1 figure, contribution to DIS2008 (April 2008), London (UK) | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the emergence of single spin asymmetries (SSA) in hard
processes using transverse momentum dependent (TMD) distribution and
fragmentation functions. Specifically, the description of SSA involves time
reversal-odd functions. Process-dependence (non-universality) in measurements
of SSA can be attributed to the non-trivial gauge link structure in the TMD
correlator. Finding the appropriate gauge links, however, also enables us to
characterize the non-universality
| [
{
"created": "Fri, 27 Jun 2008 12:23:28 GMT",
"version": "v1"
}
] | 2008-06-30 | [
[
"Mulders",
"P. J.",
""
]
] | We investigate the emergence of single spin asymmetries (SSA) in hard processes using transverse momentum dependent (TMD) distribution and fragmentation functions. Specifically, the description of SSA involves time reversal-odd functions. Process-dependence (non-universality) in measurements of SSA can be attributed to the non-trivial gauge link structure in the TMD correlator. Finding the appropriate gauge links, however, also enables us to characterize the non-universality |
2406.03755 | Jan Nemchik | B.Z. Kopeliovich and J. Nemchik | Flavor-independent yield of high-$p_T$ hadrons from nuclear collisions | 9 pages, 5 figures | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | Data on high-$p_T$ hadron production in heavy ion collisions at Feynman
$x_F=0$ indicate at universality of the observed nuclear suppression. Our
analysis of the production mechanisms demonstrates important role of the color
transparency effects which make the survival probability of a quark-antiquark
dipole independent of the quark flavor, provided that the hadron wave function
is formed outside the medium. The latter condition imposes restrictions on the
range of $p_T$, which should be sufficiently high to make the nuclear
suppression universal. We also found that the in-medium broadening rate $\hat
q$ (frequently called transport coefficient) significantly depends on the quark
flavor, diminishing for heavy quarks.
| [
{
"created": "Thu, 6 Jun 2024 05:35:33 GMT",
"version": "v1"
}
] | 2024-06-07 | [
[
"Kopeliovich",
"B. Z.",
""
],
[
"Nemchik",
"J.",
""
]
] | Data on high-$p_T$ hadron production in heavy ion collisions at Feynman $x_F=0$ indicate at universality of the observed nuclear suppression. Our analysis of the production mechanisms demonstrates important role of the color transparency effects which make the survival probability of a quark-antiquark dipole independent of the quark flavor, provided that the hadron wave function is formed outside the medium. The latter condition imposes restrictions on the range of $p_T$, which should be sufficiently high to make the nuclear suppression universal. We also found that the in-medium broadening rate $\hat q$ (frequently called transport coefficient) significantly depends on the quark flavor, diminishing for heavy quarks. |
1206.4038 | Pilar Coloma | Pilar Coloma, Tracey Li and Silvia Pascoli | A comparative study of long-baseline superbeams within LAGUNA for large
$\theta_{13}$ | 32 pages, 10 figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The Daya Bay and RENO experiments have recently observed a non-zero
$\theta_{13}$ at more than $5\sigma$ CL. This has important consequences for
future neutrino oscillation experiments. We analyze these within the LAGUNA
design study which considers seven possible locations for a European neutrino
observatory for proton decay, neutrino, and astroparticle physics. The
megaton-scale detector would be an ideal target for a CERN-based neutrino beam
with baselines ranging from 130 km to 2300 km. We perform a detailed study to
assess the physics reach of the three detector options - a 440 kton water
\v{C}erenkov, a 100 kton liquid argon and a 50 kton liquid scintillator
detector - at each of the possible locations, taking into account the recent
measurement of $\theta_{13}$. We study the impact of the beam properties and
detector performances on the sensitivity to CP-violation and the mass
hierarchy. We find that a liquid argon or water \v{C}erenkov detector can make
a $3\sigma$ discovery of CP violation for $60%-70%$ of the parameter space for
any of the baselines under consideration, although the results for the liquid
argon detector placed at 130 km are slightly worse and only $40%-50%$ is
achieved in this case. The performance of the liquid scintillator detector is
affected by its level of neutral-current background at all baselines. A
$3\sigma$ determination of the mass hierarchy is possible for all values of
$\delta$, for the values of $\theta_{13}$ favoured at $3\sigma$ by Daya Bay and
RENO, for almost all setups with $L\gtrsim 650$ km.
| [
{
"created": "Mon, 18 Jun 2012 19:53:28 GMT",
"version": "v1"
}
] | 2012-06-19 | [
[
"Coloma",
"Pilar",
""
],
[
"Li",
"Tracey",
""
],
[
"Pascoli",
"Silvia",
""
]
] | The Daya Bay and RENO experiments have recently observed a non-zero $\theta_{13}$ at more than $5\sigma$ CL. This has important consequences for future neutrino oscillation experiments. We analyze these within the LAGUNA design study which considers seven possible locations for a European neutrino observatory for proton decay, neutrino, and astroparticle physics. The megaton-scale detector would be an ideal target for a CERN-based neutrino beam with baselines ranging from 130 km to 2300 km. We perform a detailed study to assess the physics reach of the three detector options - a 440 kton water \v{C}erenkov, a 100 kton liquid argon and a 50 kton liquid scintillator detector - at each of the possible locations, taking into account the recent measurement of $\theta_{13}$. We study the impact of the beam properties and detector performances on the sensitivity to CP-violation and the mass hierarchy. We find that a liquid argon or water \v{C}erenkov detector can make a $3\sigma$ discovery of CP violation for $60%-70%$ of the parameter space for any of the baselines under consideration, although the results for the liquid argon detector placed at 130 km are slightly worse and only $40%-50%$ is achieved in this case. The performance of the liquid scintillator detector is affected by its level of neutral-current background at all baselines. A $3\sigma$ determination of the mass hierarchy is possible for all values of $\delta$, for the values of $\theta_{13}$ favoured at $3\sigma$ by Daya Bay and RENO, for almost all setups with $L\gtrsim 650$ km. |
2312.10296 | Xianhui Zhong | Qian Deng, Ru-Hui Ni, Qi Li, and Xian-Hui Zhong | Charmonia in an unquenched quark model | 24 pages, 3 figures, 15 tables | null | null | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | In this work, we study the charmonium spectrum within an unquenched quark
model including coupled-channel effects. In couple-channel calculations, we
include all of the opened charmed meson channels with the once-subtracted
method, meanwhile adopt a suppressed factor to soften the hard vertices given
by the $^3P_0$ model in the high momentum region. We obtain a good description
of both the masses and widths for the well-established states in the charmonium
spectrum. Furthermore, we give predictions for the higher $S$-, $P$- and
$D$-wave charmonium states up to mass region of $\sim 5.0$ GeV. The magnitude
of mass shifts due to the coupled-channel effects is estimated to be about
$10s$ MeV. Although many decay channels are opened for the higher charmonium
states, they are relatively narrow states. Their widths scatter in the range of
$\sim 10s-100$ MeV. Many charmonium-like states, such as $\chi_{c1}(3872)$,
$\chi_{c1}(4274)$, $\chi_{c0}(3915)$, $\chi_{c0}(4500)$, $\chi_{c0}(4700)$,
$X(4160)$, $X(4350)$, $Y(4500)$, and $\psi(4660)$/$Y(4710)$, can be
accommodated by the charmonium spectrum when the unquenched coupled-channel
effects are carefully considered.
| [
{
"created": "Sat, 16 Dec 2023 02:47:27 GMT",
"version": "v1"
}
] | 2023-12-19 | [
[
"Deng",
"Qian",
""
],
[
"Ni",
"Ru-Hui",
""
],
[
"Li",
"Qi",
""
],
[
"Zhong",
"Xian-Hui",
""
]
] | In this work, we study the charmonium spectrum within an unquenched quark model including coupled-channel effects. In couple-channel calculations, we include all of the opened charmed meson channels with the once-subtracted method, meanwhile adopt a suppressed factor to soften the hard vertices given by the $^3P_0$ model in the high momentum region. We obtain a good description of both the masses and widths for the well-established states in the charmonium spectrum. Furthermore, we give predictions for the higher $S$-, $P$- and $D$-wave charmonium states up to mass region of $\sim 5.0$ GeV. The magnitude of mass shifts due to the coupled-channel effects is estimated to be about $10s$ MeV. Although many decay channels are opened for the higher charmonium states, they are relatively narrow states. Their widths scatter in the range of $\sim 10s-100$ MeV. Many charmonium-like states, such as $\chi_{c1}(3872)$, $\chi_{c1}(4274)$, $\chi_{c0}(3915)$, $\chi_{c0}(4500)$, $\chi_{c0}(4700)$, $X(4160)$, $X(4350)$, $Y(4500)$, and $\psi(4660)$/$Y(4710)$, can be accommodated by the charmonium spectrum when the unquenched coupled-channel effects are carefully considered. |
hep-ph/0112038 | Ma Jian-ping | J.P. Ma | Spin Alignment of Heavy Meson Revisited | 6 pages, Talk given at 3rd Circum-Pan-Pacific Symposium on "High
Energy Spin Physics", Beijing, China, 8-13, 2001 | Int.J.Mod.Phys. A18 (2003) 1351-1356 | 10.1142/S0217751X03014708 | null | hep-ph | null | Using heavy quark effective theory a factorized form for inclusive production
rate of a heavy meson can be obtained, in which the nonperturbative effect
related to the heavy meson can be characterized by matrix elements defined in
the heavy quark effective theory. Using this factorization, predictions for the
full spin density matrix of a spin-1 and spin-2 meson can be obtained and they
are characterized only by one coefficient representing the nonperturbative
effect. Predictions for spin-1 heavy meson are compared with experiment
performed at $e^+e^-$ colliders in the energy range from $\sqrt{s}=10.5$GeV to
$\sqrt{s}=91$GeV, a complete agreement is found for $D^*$- and $B^*$-meson.
There are distinct differences from the existing approach and they are
discussed.
| [
{
"created": "Tue, 4 Dec 2001 01:01:05 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Ma",
"J. P.",
""
]
] | Using heavy quark effective theory a factorized form for inclusive production rate of a heavy meson can be obtained, in which the nonperturbative effect related to the heavy meson can be characterized by matrix elements defined in the heavy quark effective theory. Using this factorization, predictions for the full spin density matrix of a spin-1 and spin-2 meson can be obtained and they are characterized only by one coefficient representing the nonperturbative effect. Predictions for spin-1 heavy meson are compared with experiment performed at $e^+e^-$ colliders in the energy range from $\sqrt{s}=10.5$GeV to $\sqrt{s}=91$GeV, a complete agreement is found for $D^*$- and $B^*$-meson. There are distinct differences from the existing approach and they are discussed. |
1710.02319 | Alexander Rothkopf | Brandon Krouppa, Alexander Rothkopf and Michael Strickland | Bottomonium suppression using a lattice QCD vetted potential | 27 pages, 6 figures | Phys. Rev. D 97, 016017 (2018) | 10.1103/PhysRevD.97.016017 | null | hep-ph nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We estimate bottomonium yields in relativistic heavy-ion collisions using a
lattice QCD vetted, complex-valued, heavy-quark potential embedded in a
realistic, hydrodynamically evolving medium background. We find that the
lattice-vetted functional form and temperature dependence of the proper
heavy-quark potential dramatically reduces the dependence of the yields on
parameters other than the temperature evolution, strengthening the picture of
bottomonium as QGP thermometer. Our results also show improved agreement
between computed yields and experimental data produced in RHIC 200 GeV/nucleon
collisions. For LHC 2.76 TeV/nucleon collisions, the excited states, whose
suppression has been used as a vital sign for quark-gluon-plasma production in
a heavy-ion collision, are reproduced better than previous
perturbatively-motivated potential models; however, at the highest LHC energies
our estimates for bottomonium suppression begin to underestimate the data.
Possible paths to remedy this situation are discussed.
| [
{
"created": "Fri, 6 Oct 2017 09:09:30 GMT",
"version": "v1"
}
] | 2018-01-31 | [
[
"Krouppa",
"Brandon",
""
],
[
"Rothkopf",
"Alexander",
""
],
[
"Strickland",
"Michael",
""
]
] | We estimate bottomonium yields in relativistic heavy-ion collisions using a lattice QCD vetted, complex-valued, heavy-quark potential embedded in a realistic, hydrodynamically evolving medium background. We find that the lattice-vetted functional form and temperature dependence of the proper heavy-quark potential dramatically reduces the dependence of the yields on parameters other than the temperature evolution, strengthening the picture of bottomonium as QGP thermometer. Our results also show improved agreement between computed yields and experimental data produced in RHIC 200 GeV/nucleon collisions. For LHC 2.76 TeV/nucleon collisions, the excited states, whose suppression has been used as a vital sign for quark-gluon-plasma production in a heavy-ion collision, are reproduced better than previous perturbatively-motivated potential models; however, at the highest LHC energies our estimates for bottomonium suppression begin to underestimate the data. Possible paths to remedy this situation are discussed. |
hep-ph/0003043 | Willy van Neerven | W.L. van Neerven | Higher Order Corrections in Perturbative Quantum Chromo Dynamics | 10 pages, LaTex. To appear in PRAMANA journal of physics | Pramana 55:101-111,2000 | 10.1007/s12043-000-0087-0 | null | hep-ph | null | We present some techniques which have been developed recently or in the
recent past to compute Feynman graphs beyond one-loop order. These techniques
are useful to compute the three-loop splitting functions in QCD and to obtain
the complete second order QED corrections to Bhabha scattering.
| [
{
"created": "Mon, 6 Mar 2000 17:06:32 GMT",
"version": "v1"
}
] | 2015-06-25 | [
[
"van Neerven",
"W. L.",
""
]
] | We present some techniques which have been developed recently or in the recent past to compute Feynman graphs beyond one-loop order. These techniques are useful to compute the three-loop splitting functions in QCD and to obtain the complete second order QED corrections to Bhabha scattering. |
hep-ph/9505330 | James V. Steele | James V. Steele, Hidenaga Yamagishi, and Ismail Zahed | Master Formula Approach to Chiral Symmetry Breaking: Pi-Pi scattering | 17 pages, LaTeX, 1 postscript file of 12 figures in addition.
Equation 2 is changed, the rest is the same | Nucl.Phys. A615 (1997) 305-324 | 10.1016/S0375-9474(96)00488-5 | SUNY-NTG-95-14 | hep-ph | null | The master formula approach to chiral symmetry breaking is used to analyze
the phase shifts for $\pi\pi$ scattering in the elastic region. The results are
in excellent agreement with the data for the phase shifts up to the K-K bar
threshold. Our analysis shows that the pi-pi data near threshold in the scalar
channel favors a large quark condensate in the vacuum, i.e. <q bar q> \sim
-(240 MeV)^3.
| [
{
"created": "Wed, 17 May 1995 13:23:00 GMT",
"version": "v1"
},
{
"created": "Sun, 28 May 1995 22:23:00 GMT",
"version": "v2"
}
] | 2009-10-28 | [
[
"Steele",
"James V.",
""
],
[
"Yamagishi",
"Hidenaga",
""
],
[
"Zahed",
"Ismail",
""
]
] | The master formula approach to chiral symmetry breaking is used to analyze the phase shifts for $\pi\pi$ scattering in the elastic region. The results are in excellent agreement with the data for the phase shifts up to the K-K bar threshold. Our analysis shows that the pi-pi data near threshold in the scalar channel favors a large quark condensate in the vacuum, i.e. <q bar q> \sim -(240 MeV)^3. |
hep-ph/0003254 | Martin Maul | Martin Maul (Lund U) | Semi-classical Description of Exclusive Meson Pair Production in
$\gamma^*\gamma$ Scattering | 26 pages, Revtex, one minor typo corrected (proof reading) | Phys.Rev.D63:036003,2001 | 10.1103/PhysRevD.63.036003 | LU TP 00-08 | hep-ph | null | A semi-classical picture is given for the production of exclusive meson pairs
in \gamma\gamma^* scattering using elements of the Lund string fragmentation
model, spin and C-parity conservation. The model can be generalized to the
production of any few meson states in scattering reactions at intermediate
momentum transfers. As an example we show that we get a consistent description
for the time-like pion form factor. For the reaction \gamma\gamma^*\to
\pi^+\pi^- we find a seizable cross section at LEP2 energies.
| [
{
"created": "Sun, 26 Mar 2000 16:31:57 GMT",
"version": "v1"
},
{
"created": "Mon, 19 Jun 2000 12:04:11 GMT",
"version": "v2"
},
{
"created": "Fri, 17 Nov 2000 13:33:47 GMT",
"version": "v3"
},
{
"created": "Sat, 6 Jan 2001 15:35:31 GMT",
"version": "v4"
}
] | 2011-07-19 | [
[
"Maul",
"Martin",
"",
"Lund U"
]
] | A semi-classical picture is given for the production of exclusive meson pairs in \gamma\gamma^* scattering using elements of the Lund string fragmentation model, spin and C-parity conservation. The model can be generalized to the production of any few meson states in scattering reactions at intermediate momentum transfers. As an example we show that we get a consistent description for the time-like pion form factor. For the reaction \gamma\gamma^*\to \pi^+\pi^- we find a seizable cross section at LEP2 energies. |
hep-ph/0004192 | Nora Brambilla | N. Brambilla and A. Vairo | The Role of the QCD Vacuum in the Heavy-Quark Bound State Dynamics | Invited talk presented at the Fifth Workshop on Quantum
Chromodynamics, Villefranche-sur-Mer, France, 3-7 January 2000; 9 pages,
sprocl.sty | Proceedings of the Fifth Workshop on Quantum Chromodynamics, 8-17,
ed. H. Fried, B. Mueller and Y. Gabellini (World Scientific, Singapore, 2000) | null | HD-THEP-00-24 | hep-ph hep-lat | null | The effective field theory approach allows a rigorous disentangling of high
and low energy effects in the heavy quarkonium dynamics. Focusing in particular
on the spectrum, we describe the nature of the non-perturbative effects and
discuss our present knowledge of them.
| [
{
"created": "Thu, 20 Apr 2000 11:53:13 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Brambilla",
"N.",
""
],
[
"Vairo",
"A.",
""
]
] | The effective field theory approach allows a rigorous disentangling of high and low energy effects in the heavy quarkonium dynamics. Focusing in particular on the spectrum, we describe the nature of the non-perturbative effects and discuss our present knowledge of them. |
hep-ph/9309334 | null | R. Casalbuoni, P. Chiappetta, A. Deandrea, S. De Curtis, D. Dominici
and R. Gatto | The Bess Model at e+ e- Colliders | 14 pages and 6 figures, TeX (uses epsf.tex for figures), UGVA-DPT
1993/09-836 | null | null | null | hep-ph | null | We consider the possibility of detecting vector resonances from a strong
electroweak sector, in the framework of the BESS model, at future $e^+ e^-$
colliders up to the TeV range. If the mass $M_V$ of the new vector boson
multiplet is not far above or if it is below the maximum machine energy, such a
contribution would be manifest. The process of $W$-pair production by $e^+e^-$
annihilation allows for sensitive tests of the strong sector, especially if the
$W$ polarizations are reconstructed. Contribution to the proceedings of the
Workshop on Physics and Experiment at Linear $e^+ e^-$ Colliders - Munich,
Annecy, Hamburg 1993.
| [
{
"created": "Wed, 29 Sep 1993 17:05:00 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Casalbuoni",
"R.",
""
],
[
"Chiappetta",
"P.",
""
],
[
"Deandrea",
"A.",
""
],
[
"De Curtis",
"S.",
""
],
[
"Dominici",
"D.",
""
],
[
"Gatto",
"R.",
""
]
] | We consider the possibility of detecting vector resonances from a strong electroweak sector, in the framework of the BESS model, at future $e^+ e^-$ colliders up to the TeV range. If the mass $M_V$ of the new vector boson multiplet is not far above or if it is below the maximum machine energy, such a contribution would be manifest. The process of $W$-pair production by $e^+e^-$ annihilation allows for sensitive tests of the strong sector, especially if the $W$ polarizations are reconstructed. Contribution to the proceedings of the Workshop on Physics and Experiment at Linear $e^+ e^-$ Colliders - Munich, Annecy, Hamburg 1993. |
2301.06311 | B\'arbara Cid-Mora | B.A. Cid-Mora, T.G. Steele | NLO Effects in QCD Sum-Rule Analyses of $f_{0}(500)$ as a Tetraquark
state | null | PoS \textbf{LATTICE2022} (2023) | 10.22323/1.430.0258 | 258 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | QCD sum-rule studies have been useful to understand and get an insight on the
structure of exotic states, such as tetraquark systems. Moreover, the majority
of these studies are performed only at leading-order (LO) within the light
tetraquarks systems picture, overlooking the effects of higher order
corrections, thus motivating our analysis. Our study focused on the effects of
next-to-leading order (NLO) contributions to the mass estimates of the lightest
tetraquark state ($J^{PC} = 0^{++}$), the so-called $\sigma$ or $f_{0}(500)$,
using ratios of QCD Laplace sum-rules. A variety of different models were used,
which included multiple resonances and width effects, resulting in a final mass
prediction of $0.52\,\text{GeV}< m_{\sigma}< 0.77\,\text{GeV}$. Even though the
ratios of sum-rules demonstrated some insensitivity under superficially large
NLO contributions, they added the beneficial feature of canceling the
dependence on the anomalous dimension. Our findings were in good agreement with
patterns found in Chiral Lagrangian studies regarding the four-quark structure
of the $\sigma$ state, including the relative coupling strengths within the
multiple resonance analysis.
| [
{
"created": "Mon, 16 Jan 2023 08:53:55 GMT",
"version": "v1"
}
] | 2024-01-22 | [
[
"Cid-Mora",
"B. A.",
""
],
[
"Steele",
"T. G.",
""
]
] | QCD sum-rule studies have been useful to understand and get an insight on the structure of exotic states, such as tetraquark systems. Moreover, the majority of these studies are performed only at leading-order (LO) within the light tetraquarks systems picture, overlooking the effects of higher order corrections, thus motivating our analysis. Our study focused on the effects of next-to-leading order (NLO) contributions to the mass estimates of the lightest tetraquark state ($J^{PC} = 0^{++}$), the so-called $\sigma$ or $f_{0}(500)$, using ratios of QCD Laplace sum-rules. A variety of different models were used, which included multiple resonances and width effects, resulting in a final mass prediction of $0.52\,\text{GeV}< m_{\sigma}< 0.77\,\text{GeV}$. Even though the ratios of sum-rules demonstrated some insensitivity under superficially large NLO contributions, they added the beneficial feature of canceling the dependence on the anomalous dimension. Our findings were in good agreement with patterns found in Chiral Lagrangian studies regarding the four-quark structure of the $\sigma$ state, including the relative coupling strengths within the multiple resonance analysis. |
2310.12420 | Waqas Ahmed | Imtiaz Khan, Waqas Ahmed, Tianjun Li, Shabbar Raza | Revisit a realistic intersecting D6-brane with modified soft SUSY terms | 18 pages, 6 figures | null | null | null | hep-ph hep-th | http://creativecommons.org/licenses/by-nc-nd/4.0/ | Because there are a few typos in the supersymmetry breaking sfermion masses
and trilinear soft term, regarding the current Large Hadron Collider (LHC) and
dark matter searches, we revisit a three-family Pati-Salam model based on
intersecting D6-branes in Type IIA string theory on a $\mathbf{T^6/(\Z_2\times
\Z_2)}$ orientifold with a realistic phenomenology. We study the viable
parameter space and discuss the spectrum consistent with the current LHC
Supersymmetry searches along with the dark matter relic density bounds from the
Planck 2018 data. For the gluinos and first two generations of sfermions, we
observe that the gluino mass is in the range [2, 14] TeV, the squarks mass
range is [2, 13] TeV and the sleptons mass is in the range [1, 5] TeV. We
achieve the cold dark matter relic density consistent with 5$\sigma$ Planck
2018 bounds via A-funnel and coannihilation channels such as stop-neutralino,
stau-neutralino, and chargino-neutralino. Except for a few chargino-neutralino
coannihilation solutions, these solutions also satisfy current
nucleon-neutralino spin-independent and spin-dependent scattering
cross-sections and may be probed by future dark matter searches.
| [
{
"created": "Thu, 19 Oct 2023 02:14:36 GMT",
"version": "v1"
}
] | 2023-10-20 | [
[
"Khan",
"Imtiaz",
""
],
[
"Ahmed",
"Waqas",
""
],
[
"Li",
"Tianjun",
""
],
[
"Raza",
"Shabbar",
""
]
] | Because there are a few typos in the supersymmetry breaking sfermion masses and trilinear soft term, regarding the current Large Hadron Collider (LHC) and dark matter searches, we revisit a three-family Pati-Salam model based on intersecting D6-branes in Type IIA string theory on a $\mathbf{T^6/(\Z_2\times \Z_2)}$ orientifold with a realistic phenomenology. We study the viable parameter space and discuss the spectrum consistent with the current LHC Supersymmetry searches along with the dark matter relic density bounds from the Planck 2018 data. For the gluinos and first two generations of sfermions, we observe that the gluino mass is in the range [2, 14] TeV, the squarks mass range is [2, 13] TeV and the sleptons mass is in the range [1, 5] TeV. We achieve the cold dark matter relic density consistent with 5$\sigma$ Planck 2018 bounds via A-funnel and coannihilation channels such as stop-neutralino, stau-neutralino, and chargino-neutralino. Except for a few chargino-neutralino coannihilation solutions, these solutions also satisfy current nucleon-neutralino spin-independent and spin-dependent scattering cross-sections and may be probed by future dark matter searches. |
hep-ph/0010121 | Abdelkader-Salim Safir | F. Iddir and A. S. Safir | The decay of the observed $J^{PC}=1^{-+}$ (1400) and
$J^{PC}=1^{-+}$(1600) hybrid candidates | 13 pages, 1 figure | Phys.Lett.B507:183-192,2001 | 10.1016/S0370-2693(01)00470-1 | null | hep-ph | null | We study the possible interpretation of the two exotic resonances $J^{PC}=
1^{-+}$ at 1400 and 1600 MeV, claimed to be observed by BNL, decaying
respectively into $\eta\pi$, $\eta'\pi$, $f_{1}\pi$ and $\rho\pi$. These
objects are interpreted as hybrid mesons, in the quark-gluon constituent model
using a chromoharmonic confining potentiel.
The quantum numbers $J^{PC}I^{G} = 1^{-+} 1^{-}$ can be considered in a
constituent model as an hybrid meson ($q \bar q g$). The lowest $J^{PC}=
1^{-+}$states may be built in two ways : $l_{g}$=1 (gluon-excited)
corresponding to an angular momentum between the gluon and ($q \bar q$) system,
while $l_{q \bar q}=1$ (quarks-excited) corresponds to an angular momentum
between $q$ and $\bar q$. For the gluon-excited mode $1^{-+}$ hybrids, we find
the decay dominated by the $b_{1}\pi$ channel, and by the $\rho \pi$ channel
for the quark-excited mode. In our model, neither the quark-excited nor the
gluon-excited $1^{-+}$ (1400 MeV) hybrids can decay into $\eta\pi$ and
$\eta'\pi$, in contradiction with experiment. Hence, the 1400 MeV resonance
seems unlikely to be an hybrid state. The $1^{-+}$ (1600 MeV) gluon-excited
hybrid is predicted with too large a total decay width, to be considered as an
hybrid candidate. On the contrary the quark-excited mode has a total decay
width around 165 MeV, with a $\rho \pi$ preferred decay channel, in agreement
with BNL. Our conclusion is that {\it{this resonance may be considered as a
hybrid meson in the quark-excited mode}}
| [
{
"created": "Thu, 12 Oct 2000 14:46:22 GMT",
"version": "v1"
},
{
"created": "Tue, 20 Mar 2001 14:43:45 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Iddir",
"F.",
""
],
[
"Safir",
"A. S.",
""
]
] | We study the possible interpretation of the two exotic resonances $J^{PC}= 1^{-+}$ at 1400 and 1600 MeV, claimed to be observed by BNL, decaying respectively into $\eta\pi$, $\eta'\pi$, $f_{1}\pi$ and $\rho\pi$. These objects are interpreted as hybrid mesons, in the quark-gluon constituent model using a chromoharmonic confining potentiel. The quantum numbers $J^{PC}I^{G} = 1^{-+} 1^{-}$ can be considered in a constituent model as an hybrid meson ($q \bar q g$). The lowest $J^{PC}= 1^{-+}$states may be built in two ways : $l_{g}$=1 (gluon-excited) corresponding to an angular momentum between the gluon and ($q \bar q$) system, while $l_{q \bar q}=1$ (quarks-excited) corresponds to an angular momentum between $q$ and $\bar q$. For the gluon-excited mode $1^{-+}$ hybrids, we find the decay dominated by the $b_{1}\pi$ channel, and by the $\rho \pi$ channel for the quark-excited mode. In our model, neither the quark-excited nor the gluon-excited $1^{-+}$ (1400 MeV) hybrids can decay into $\eta\pi$ and $\eta'\pi$, in contradiction with experiment. Hence, the 1400 MeV resonance seems unlikely to be an hybrid state. The $1^{-+}$ (1600 MeV) gluon-excited hybrid is predicted with too large a total decay width, to be considered as an hybrid candidate. On the contrary the quark-excited mode has a total decay width around 165 MeV, with a $\rho \pi$ preferred decay channel, in agreement with BNL. Our conclusion is that {\it{this resonance may be considered as a hybrid meson in the quark-excited mode}} |
hep-ph/0601069 | Jing-Jing Liu | Wu Peng, Ma Wen-Gan, Zhang Ren-You, Jiang Yi, Han Liang, Guo Lei | NLO supersymmetric QCD corrections to the $t \bar b H^-$ associated
production at hadron colliders | Latex files, 26 eps figures included. Accepted for publication in
Phys. Rev. D | Phys.Rev.D73:015012,2006; Erratum-ibid.D80:059901,2009 | 10.1103/PhysRevD.73.015012 10.1103/PhysRevD.80.059901 | null | hep-ph | null | We present the next-to-leading order QCD corrected total cross sections and
the distributions of the transverse momenta of the final anti-bottom-quark,
top-quark and charged Higgs-boson for the processes of $p\bar p/pp \to t\bar b
H^-+X$ in the minimal supersymmetric standard model(MSSM) at the Tevatron and
the LHC. We find that the NLO QCD corrections significantly modify the
leading-order distributions of the transverse momenta of final
particles($p_T^b$, $p_T^t$ and $p_T^{H^-}$), and the total NLO QCD corrections
reduce the dependence of the cross section on the renormalization and
factorization scales, especially the NLO QCD corrected cross sections at the
LHC are nearly independent of these scales. Our results show that the relative
correction is obviously related to $m_{H^-}$ and $\tan\beta$, and the total NLO
QCD relative corrections can be beyond -50% at the Tevatron and approach -40%
at the LHC in our chosen parameter space.
| [
{
"created": "Tue, 10 Jan 2006 08:56:01 GMT",
"version": "v1"
}
] | 2014-11-18 | [
[
"Peng",
"Wu",
""
],
[
"Wen-Gan",
"Ma",
""
],
[
"Ren-You",
"Zhang",
""
],
[
"Yi",
"Jiang",
""
],
[
"Liang",
"Han",
""
],
[
"Lei",
"Guo",
""
]
] | We present the next-to-leading order QCD corrected total cross sections and the distributions of the transverse momenta of the final anti-bottom-quark, top-quark and charged Higgs-boson for the processes of $p\bar p/pp \to t\bar b H^-+X$ in the minimal supersymmetric standard model(MSSM) at the Tevatron and the LHC. We find that the NLO QCD corrections significantly modify the leading-order distributions of the transverse momenta of final particles($p_T^b$, $p_T^t$ and $p_T^{H^-}$), and the total NLO QCD corrections reduce the dependence of the cross section on the renormalization and factorization scales, especially the NLO QCD corrected cross sections at the LHC are nearly independent of these scales. Our results show that the relative correction is obviously related to $m_{H^-}$ and $\tan\beta$, and the total NLO QCD relative corrections can be beyond -50% at the Tevatron and approach -40% at the LHC in our chosen parameter space. |
hep-ph/0205016 | Osman Yilmaz | A. Gokalp, A. Kucukarslan, S. Solmaz, O. Yilmaz (Middle East Technical
University, Ankara-Turkey) | Scalar $a_0(980)$ meson in $\phi\to \pi^{0}\eta\gamma$ decay | 18 pages, RevTeX, 6 PS figures. A rounding-off error in printing the
horizontal axes of figures resulting from the computer program Grapher is
corrected. Journal Ref.: J. Phys. G: Nucl. Part. Phys. 28 (2002) 2783-2793 | J.Phys.G28:2783-2793,2002; Erratum-ibid.G28:3021,2002 | 10.1088/0954-3899/28/11/304 | null | hep-ph | null | We study the radiative decay $\phi\to\pi^{0}\eta\gamma$ within the framework
of a phenomenological approach in which the contributions of $\rho$-meson,
chiral loop and $a_0$-meson are considered. We analyze the interference effects
between different contributions and utilizing the experimental branching ratio
and invariant $\pi^0\eta$ mass spectrum for $\phi\to\pi^{0}\eta\gamma$ decay we
estimate the branching ratio of $\phi\to a_0\gamma$ decay.
| [
{
"created": "Thu, 2 May 2002 11:01:20 GMT",
"version": "v1"
},
{
"created": "Wed, 30 Oct 2002 14:34:32 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Gokalp",
"A.",
"",
"Middle East Technical\n University, Ankara-Turkey"
],
[
"Kucukarslan",
"A.",
"",
"Middle East Technical\n University, Ankara-Turkey"
],
[
"Solmaz",
"S.",
"",
"Middle East Technical\n University, Ankara-Turkey"
],
[
"Yilmaz",
... | We study the radiative decay $\phi\to\pi^{0}\eta\gamma$ within the framework of a phenomenological approach in which the contributions of $\rho$-meson, chiral loop and $a_0$-meson are considered. We analyze the interference effects between different contributions and utilizing the experimental branching ratio and invariant $\pi^0\eta$ mass spectrum for $\phi\to\pi^{0}\eta\gamma$ decay we estimate the branching ratio of $\phi\to a_0\gamma$ decay. |
hep-ph/0104009 | Dr Rukmani Mohanta | A. K. Giri, R. Mohanta and M. P. Khanna | Determination of the angle $\gamma$ from nonleptonic $B_c \to D_s D^0$
decays | 12 pages, LaTeX, 2 references added, Minor changes in the text, to
appear in Phys. Rev. D | Phys.Rev.D65:034016,2002 | 10.1103/PhysRevD.65.034016 | null | hep-ph | null | We note that the two body nonleptonic pure tree decays $B_c^\pm \to D_s^\pm
D^0(\bar D^0)$ and the corresponding vector-vector modes $B_c^\pm \to D_s^{*
\pm} D^{*0}(\bar D^{* 0}) $ are well suited to extract the weak phase $\gamma$
of the unitarity triangle. The CP violating phase $\gamma$ can be determined
cleanly as these decay modes are free from the penguin pollutions.
| [
{
"created": "Mon, 2 Apr 2001 07:47:53 GMT",
"version": "v1"
},
{
"created": "Mon, 17 Dec 2001 03:03:59 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"Giri",
"A. K.",
""
],
[
"Mohanta",
"R.",
""
],
[
"Khanna",
"M. P.",
""
]
] | We note that the two body nonleptonic pure tree decays $B_c^\pm \to D_s^\pm D^0(\bar D^0)$ and the corresponding vector-vector modes $B_c^\pm \to D_s^{* \pm} D^{*0}(\bar D^{* 0}) $ are well suited to extract the weak phase $\gamma$ of the unitarity triangle. The CP violating phase $\gamma$ can be determined cleanly as these decay modes are free from the penguin pollutions. |
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