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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1106.4589 | Gil Paz | Gil Paz | Direct CP Asymmetry in B->X_{s,d}+gamma Decays | 4 pages, invited talk at Rencontres de Moriond 2011, QCD and High
Energy Interactions, La Thuile, Italy, 20-27 March 2011, to appear in the
Proceedings, and eConf C110809 (2012) | Proceedings of the 47th Rencontres de Moriond - 2011 QCD and High
Energy Interactions, Th\^e Gi\'oi Publishers, Vietnam, pages 139 - 142 | null | EFI Preprint 11-14 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The CP asymmetry in inclusive B->X_{s,d}+gamma decays is an important probe
of new physics. The theoretical prediction was thought to be of a perturbative
origin, and in the standard model, to be about 0.5 percent. In a recent work
with M. Benzke, S.J. Lee and M. Neubert, we have shown that the asymmetry is in
fact dominated by non-perturbative effects. Since these are hard to estimate,
it reduces the sensitivity to new physics effects. On the other hand, these new
non-perturbative effects suggest a new test of new physics by looking at the
difference of the CP asymmetries in charged versus neutral B-meson decays.
| [
{
"created": "Wed, 22 Jun 2011 22:27:13 GMT",
"version": "v1"
}
] | 2012-06-18 | [
[
"Paz",
"Gil",
""
]
] | The CP asymmetry in inclusive B->X_{s,d}+gamma decays is an important probe of new physics. The theoretical prediction was thought to be of a perturbative origin, and in the standard model, to be about 0.5 percent. In a recent work with M. Benzke, S.J. Lee and M. Neubert, we have shown that the asymmetry is in fact dominated by non-perturbative effects. Since these are hard to estimate, it reduces the sensitivity to new physics effects. On the other hand, these new non-perturbative effects suggest a new test of new physics by looking at the difference of the CP asymmetries in charged versus neutral B-meson decays. |
2408.04776 | Takeshi Fukuyama | Takeshi Fukuyama | Ultralight axion and modern cosmology tensions | 9 pages 1 figure | null | null | null | hep-ph astro-ph.CO gr-qc | http://creativecommons.org/licenses/by/4.0/ | String-inspired axion model is considered to comprehensively solve the
problems of modern cosmology, Hubble tension problem, the origin of the
stochastic gravitational wave background, and too early formation of
supermassive black holes at high $z$.
| [
{
"created": "Thu, 8 Aug 2024 22:18:49 GMT",
"version": "v1"
}
] | 2024-08-12 | [
[
"Fukuyama",
"Takeshi",
""
]
] | String-inspired axion model is considered to comprehensively solve the problems of modern cosmology, Hubble tension problem, the origin of the stochastic gravitational wave background, and too early formation of supermassive black holes at high $z$. |
hep-ph/0703069 | Anatoly Radyushkin | Hovhannes R. Grigoryan and Anatoly V. Radyushkin | Form Factors and Wave Functions of Vector Mesons in Holographic QCD | 7 pages, RevTex. References were added, some modifications in the
text were made | Phys.Lett.B650:421-427,2007 | 10.1016/j.physletb.2007.05.044 | JLAB-THY-07-624 | hep-ph hep-lat hep-th nucl-th | null | Within the framework of a holographic dual model of QCD, we develop a
formalism for calculating form factors of vector mesons. We show that the
holographic bound states can be described not only in terms of eigenfunctions
of the equation of motion, but also in terms of conjugate wave functions that
are close analogues of quantum-mechanical bound state wave functions. We derive
a generalized VMD representation for form factors, and find a very specific VMD
pattern, in which form factors are essentially given by contributions due to
the first two bound states in the Q^2-channel. We calculate electric radius of
the rho-meson, finding the value <r_rho^2>_C = 0.53 fm^2.
| [
{
"created": "Tue, 6 Mar 2007 17:59:17 GMT",
"version": "v1"
},
{
"created": "Wed, 23 May 2007 17:26:17 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Grigoryan",
"Hovhannes R.",
""
],
[
"Radyushkin",
"Anatoly V.",
""
]
] | Within the framework of a holographic dual model of QCD, we develop a formalism for calculating form factors of vector mesons. We show that the holographic bound states can be described not only in terms of eigenfunctions of the equation of motion, but also in terms of conjugate wave functions that are close analogues of quantum-mechanical bound state wave functions. We derive a generalized VMD representation for form factors, and find a very specific VMD pattern, in which form factors are essentially given by contributions due to the first two bound states in the Q^2-channel. We calculate electric radius of the rho-meson, finding the value <r_rho^2>_C = 0.53 fm^2. |
1608.05782 | Manjunath Bhat | Antony Prakash Monteiro, Manjunath Bhat, K. B. Vijaya Kumar | $c\bar{b}$ spectrum and decay properties with coupled channel effects | 15 pages. arXiv admin note: substantial text overlap with
arXiv:1601.05874, arXiv:1607.07594 | Phys. Rev. D 95, 054016 (2017) | 10.1103/PhysRevD.95.054016 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | The mass spectrum of $c\bar{b}$ states has been obtained using the
phenomenological relativistic quark model (RQM) with coupled channel effects.
The Hamiltonian used in the investigation has confinement potential and
confined one gluon exchange potential (COGEP). In the frame work of RQM a study
of M1 and E1 radiative decays of $c\bar{b}$ states has been made. The weak
decay widths in the spectator quark approximation have been estimated. An
overall agreement is obtained with the experimental masses and decay widths.
| [
{
"created": "Sat, 20 Aug 2016 05:08:02 GMT",
"version": "v1"
},
{
"created": "Thu, 6 Oct 2016 12:16:44 GMT",
"version": "v2"
},
{
"created": "Wed, 22 Feb 2017 11:57:49 GMT",
"version": "v3"
}
] | 2017-03-24 | [
[
"Monteiro",
"Antony Prakash",
""
],
[
"Bhat",
"Manjunath",
""
],
[
"Kumar",
"K. B. Vijaya",
""
]
] | The mass spectrum of $c\bar{b}$ states has been obtained using the phenomenological relativistic quark model (RQM) with coupled channel effects. The Hamiltonian used in the investigation has confinement potential and confined one gluon exchange potential (COGEP). In the frame work of RQM a study of M1 and E1 radiative decays of $c\bar{b}$ states has been made. The weak decay widths in the spectator quark approximation have been estimated. An overall agreement is obtained with the experimental masses and decay widths. |
1708.04093 | Zolt\'an Tulip\'ant | Zolt\'an Tulip\'ant, Adam Kardos and G\'abor Somogyi | Energy-energy correlation in electron-positron annihilation at NNLL+NNLO
accuracy | 24 pages, 7 figures and 1 table, published version | null | 10.1140/epjc/s10052-017-5320-9 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the computation of energy-energy correlation in $e^+e^-$
collisions in the back-to-back region at next-to-next-to-leading logarithmic
accuracy matched with the next-to-next-to-leading order perturbative
prediction. We study the effect of the fixed higher order corrections in a
comparison of our results to LEP and SLC data. The next-to-next-to-leading
order correction has a sizable impact on the extracted value of
$\alpha_{\mathrm S}(M_Z)$, hence its inclusion is mandatory for a precise
measurement of the strong coupling using energy-energy correlation.
| [
{
"created": "Mon, 14 Aug 2017 12:21:51 GMT",
"version": "v1"
},
{
"created": "Wed, 15 Nov 2017 10:00:27 GMT",
"version": "v2"
}
] | 2017-12-06 | [
[
"Tulipánt",
"Zoltán",
""
],
[
"Kardos",
"Adam",
""
],
[
"Somogyi",
"Gábor",
""
]
] | We present the computation of energy-energy correlation in $e^+e^-$ collisions in the back-to-back region at next-to-next-to-leading logarithmic accuracy matched with the next-to-next-to-leading order perturbative prediction. We study the effect of the fixed higher order corrections in a comparison of our results to LEP and SLC data. The next-to-next-to-leading order correction has a sizable impact on the extracted value of $\alpha_{\mathrm S}(M_Z)$, hence its inclusion is mandatory for a precise measurement of the strong coupling using energy-energy correlation. |
hep-ph/0504048 | Edward Shuryak | E.Shuryak | Interactions between hadrons are strongly modified near the QCD
(tri)critical point | null | null | null | null | hep-ph | null | The QCD (tri)critical point, a genuine second-order phase transition, implies
existence of a massless scalar mode, and singular behavior near it. In this
work we however focus on the finite region around it, defined by a condition
$m_\sigma=2m_\pi$. We point out that in this region the inter-hadron
interaction should be dramatically changed. Light sigma should increase
attractive mean field potentials for baryons and non-Goldstone mesons. The same
effect can be observed in additional downward shift of the mass of vector
mesons $\rho,\omega,\phi$, accessible via dilepton experiments. For pions we
predict that the mean change due to light sigma is in fact a
$repulsive$ mean potential. The implications of these effects for collective
pion and nucleon flows, radial directed and elliptic, are estimated. Finally,
we speculate tha unusual behavior of flows observed by NA49 at 40 GeV PbPb
collisions at SPS may be explained by location of the critical point region
nearby.
| [
{
"created": "Wed, 6 Apr 2005 16:39:05 GMT",
"version": "v1"
}
] | 2016-09-06 | [
[
"Shuryak",
"E.",
""
]
] | The QCD (tri)critical point, a genuine second-order phase transition, implies existence of a massless scalar mode, and singular behavior near it. In this work we however focus on the finite region around it, defined by a condition $m_\sigma=2m_\pi$. We point out that in this region the inter-hadron interaction should be dramatically changed. Light sigma should increase attractive mean field potentials for baryons and non-Goldstone mesons. The same effect can be observed in additional downward shift of the mass of vector mesons $\rho,\omega,\phi$, accessible via dilepton experiments. For pions we predict that the mean change due to light sigma is in fact a $repulsive$ mean potential. The implications of these effects for collective pion and nucleon flows, radial directed and elliptic, are estimated. Finally, we speculate tha unusual behavior of flows observed by NA49 at 40 GeV PbPb collisions at SPS may be explained by location of the critical point region nearby. |
1708.09768 | Peter Hayman | C.P. Burgess, P. Hayman, Markus Rummel, Laszlo Zalavari | Reduced Theoretical Error for QED Tests with 4He+ Spectroscopy | 21 pages, 4 plots; This version greatly expands the mathematical
background and detailed derivations of our results. Application of our
results to available experimental data is also included | Phys. Rev. A 98, 052510 (2018) | 10.1103/PhysRevA.98.052510 | null | hep-ph hep-th physics.atom-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We apply point-particle effective field theory (PPEFT) to electronic and
muonic 4He+ ions, and use it to identify linear combinations of spectroscopic
measurements for which the theoretical uncertainties are much smaller than for
any particular energy levels. The error is reduced because these combinations
are independent of all short-range physics effects up to a given order in the
expansion in the small parameters R/a_B and(Z alpha) (where R and a_B are the
ion's nuclear and Bohr radii). In particular, the theory error is not limited
by the precision with which nuclear matrix elements can be computed, or
compromised by the existence of any novel short-range interactions, should
these exist. These combinations of 4He+ measurements therefore provide
particularly precise tests of QED. The restriction to 4He+ arises because our
analysis assumes a spherically symmetric nucleus, but the argument used is more
general and extendable to both nuclei with spin, and to higher orders in R/a_B
and (Z alpha).
| [
{
"created": "Thu, 31 Aug 2017 15:14:50 GMT",
"version": "v1"
},
{
"created": "Thu, 25 Jan 2018 19:27:31 GMT",
"version": "v2"
},
{
"created": "Tue, 23 Oct 2018 20:44:55 GMT",
"version": "v3"
}
] | 2018-11-28 | [
[
"Burgess",
"C. P.",
""
],
[
"Hayman",
"P.",
""
],
[
"Rummel",
"Markus",
""
],
[
"Zalavari",
"Laszlo",
""
]
] | We apply point-particle effective field theory (PPEFT) to electronic and muonic 4He+ ions, and use it to identify linear combinations of spectroscopic measurements for which the theoretical uncertainties are much smaller than for any particular energy levels. The error is reduced because these combinations are independent of all short-range physics effects up to a given order in the expansion in the small parameters R/a_B and(Z alpha) (where R and a_B are the ion's nuclear and Bohr radii). In particular, the theory error is not limited by the precision with which nuclear matrix elements can be computed, or compromised by the existence of any novel short-range interactions, should these exist. These combinations of 4He+ measurements therefore provide particularly precise tests of QED. The restriction to 4He+ arises because our analysis assumes a spherically symmetric nucleus, but the argument used is more general and extendable to both nuclei with spin, and to higher orders in R/a_B and (Z alpha). |
0901.1546 | Jignesh Pandya | Ajay Kumar Rai, J N Pandya and P C Vinodkumar | Decay rates of quarkonia with NRQCD formalism using spectroscopic
parameters of potential models | 15 pages | Eur.Phys.J.A38:77-84,2008 | 10.1140/epja/i2008-10639-9 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Decay rates of quarkonia are studied within the framework of NRQCD formalism.
The basic parameters of the formalism have been obtained from different
potential schemes studied for the spectra of quarkonia. We estimate the heavy
quarkonia mass spectra, radiative and leptonic widths and compare them with
other contemporary theoretical approaches and experimental results.
| [
{
"created": "Mon, 12 Jan 2009 10:51:15 GMT",
"version": "v1"
}
] | 2009-02-25 | [
[
"Rai",
"Ajay Kumar",
""
],
[
"Pandya",
"J N",
""
],
[
"Vinodkumar",
"P C",
""
]
] | Decay rates of quarkonia are studied within the framework of NRQCD formalism. The basic parameters of the formalism have been obtained from different potential schemes studied for the spectra of quarkonia. We estimate the heavy quarkonia mass spectra, radiative and leptonic widths and compare them with other contemporary theoretical approaches and experimental results. |
2211.13209 | John Terry | Leonard Gamberg, Zhong-Bo Kang, Ding Yu Shao, John Terry, and Fanyi
Zhao | Transverse-momentum-dependent factorization at next-to-leading power | 60 pages, 15 figures. In this update, we added additional
clarification and discussion in the introduction and conclusion | null | null | null | hep-ph nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study transverse momentum dependent factorization and resummation at
sub-leading power in Drell-Yan and semi-inclusive deep inelastic scattering. In
these processes the sub-leading power contributions to the cross section enter
as a kinematic power correction to the leptonic tensor, and the kinematic,
intrinsic, and dynamic sub-leading contributions to the hadronic tensor. By
consistently treating the power counting of the interactions, we demonstrate
renormalization group consistency. We calculate the anomalous dimensions of the
kinematic and intrinsic sub-leading correlation functions at one loop and find
that the evolution equations give rise to anomalous dimension matrices which
mix leading and sub-leading power distribution functions. Additionally we
calculate the hard and soft functions associated with each of these
contributions. We find that these hard and soft contributions differ from those
at the leading power. Finally, we calculate the rapidity anomalous dimension
for the dynamic sub-leading distributions and find that it is the same as the
leading power anomalous dimension. We then comment on the implications for the
soft function associated with this contribution. Using this information, we
establish the factorization formalism at sub-leading power for these processes
at the one-loop level.
| [
{
"created": "Wed, 23 Nov 2022 18:51:28 GMT",
"version": "v1"
},
{
"created": "Tue, 14 Feb 2023 16:56:26 GMT",
"version": "v2"
}
] | 2023-02-15 | [
[
"Gamberg",
"Leonard",
""
],
[
"Kang",
"Zhong-Bo",
""
],
[
"Shao",
"Ding Yu",
""
],
[
"Terry",
"John",
""
],
[
"Zhao",
"Fanyi",
""
]
] | We study transverse momentum dependent factorization and resummation at sub-leading power in Drell-Yan and semi-inclusive deep inelastic scattering. In these processes the sub-leading power contributions to the cross section enter as a kinematic power correction to the leptonic tensor, and the kinematic, intrinsic, and dynamic sub-leading contributions to the hadronic tensor. By consistently treating the power counting of the interactions, we demonstrate renormalization group consistency. We calculate the anomalous dimensions of the kinematic and intrinsic sub-leading correlation functions at one loop and find that the evolution equations give rise to anomalous dimension matrices which mix leading and sub-leading power distribution functions. Additionally we calculate the hard and soft functions associated with each of these contributions. We find that these hard and soft contributions differ from those at the leading power. Finally, we calculate the rapidity anomalous dimension for the dynamic sub-leading distributions and find that it is the same as the leading power anomalous dimension. We then comment on the implications for the soft function associated with this contribution. Using this information, we establish the factorization formalism at sub-leading power for these processes at the one-loop level. |
hep-ph/0002070 | Sergey Kovalenko | T.S. Kosmas and Sergey Kovalenko | Lepton Flavor Violation: Constraints from exotic muon to electron
conversion | 14 pages, 2 figures. Based on the Invited talk given by T.S. Kosmas
at the International Conference on Non-Accelerator New Physics(NANP'99),
Dubna, Russia, 1999 | Phys.Atom.Nucl.63:1158-1164,2000; Yad.Fiz.63N7:1234-1239,2000 | 10.1134/1.855761 | null | hep-ph nucl-th | null | The exotic neutrinoless $\mu^- - e^-$ nuclear conversion is studied within
the conventional extensions of the standard model as well as in the minimal
supersymmetric (SUSY) models with and without R-parity conservation. The
dependence of the $\mu^- - e^-$ conversion rates on the nucleon and nuclear
structure is consistently taken into account. Using our calculated transition
matrix elements and the available experimental data on the branching ratio
$R_{\mu e^-}$ for $^{48}$Ti and $^{208}$Pb as well as the expected experimental
sensitivity for $^{27}$Al employed as a target in the planned at Brookhaven
$\mu^--e^-$ conversion (MECO) experiment, we extract very severe constraints
for the flavor violation parameters. We especially emphasize on the constraints
resulting for SUSY R-parity violating parameters.
| [
{
"created": "Mon, 7 Feb 2000 16:25:25 GMT",
"version": "v1"
}
] | 2011-04-15 | [
[
"Kosmas",
"T. S.",
""
],
[
"Kovalenko",
"Sergey",
""
]
] | The exotic neutrinoless $\mu^- - e^-$ nuclear conversion is studied within the conventional extensions of the standard model as well as in the minimal supersymmetric (SUSY) models with and without R-parity conservation. The dependence of the $\mu^- - e^-$ conversion rates on the nucleon and nuclear structure is consistently taken into account. Using our calculated transition matrix elements and the available experimental data on the branching ratio $R_{\mu e^-}$ for $^{48}$Ti and $^{208}$Pb as well as the expected experimental sensitivity for $^{27}$Al employed as a target in the planned at Brookhaven $\mu^--e^-$ conversion (MECO) experiment, we extract very severe constraints for the flavor violation parameters. We especially emphasize on the constraints resulting for SUSY R-parity violating parameters. |
hep-ph/0509140 | Xiang Liu | Xiao-Gang He, Xue-Qian Li, Xiang Liu and J.P. Ma | Some properties of the newly observed X(1835) state at BES | 13 pages, 3 figures. The final version to appear at EPJC | Eur.Phys.J.C49:731-736,2007 | 10.1140/epjc/s10052-006-0129-y | null | hep-ph | null | Recently the BES collaboration has announced observation of a resonant state
in the $\pi^+\pi^- \eta'$ spectrum in $J/\psi \to \gamma \pi^+\pi^-\eta'$
decay. Fitting the data with a $0^{-+}$ state, the mass is determined to be
1833.7 MeV with $7.7\sigma$ statistic significance. This state is consistent
with the one extracted from previously reported $p \bar p$ threshold
enhancement data in $J/\psi \to \gamma p \bar p$. We study the properties of
this state using QCD anomaly and QCD sum rules assuming X(1835) to be a
pseudoscalar and show that it is consistent with data. We find that this state
has a sizeable matrix element $<0|G\tilde G|G_p>$ leading to branching ratios
of $(2.61\sim 7.37)\times 10^{-3}$ and $(2.21\sim 10.61)\times 10^{-2}$ for
$J/\psi \to \gamma G_p$ and for $G_p \to \pi^+\pi^- \eta'$, respectively.
Combining the calculated branching ratio of $J/\psi \to \gamma G_p$ and data on
threshold enhancement in $J/\psi \to \gamma p \bar p$, we determine the
coupling for $G_p- p-\bar p$ interaction. We finally study branching ratios of
other $J/\psi \to \gamma + {three mesons}$ decay modes. We find that $J/\psi
\to \gamma G_p \to \gamma (\pi^+\pi^- \eta, K K \pi^0)$ can provide useful
tests for the mechanism proposed.
| [
{
"created": "Wed, 14 Sep 2005 09:04:36 GMT",
"version": "v1"
},
{
"created": "Mon, 26 Sep 2005 13:08:30 GMT",
"version": "v2"
},
{
"created": "Mon, 19 Dec 2005 13:59:19 GMT",
"version": "v3"
},
{
"created": "Thu, 28 Sep 2006 11:06:39 GMT",
"version": "v4"
}
] | 2008-11-26 | [
[
"He",
"Xiao-Gang",
""
],
[
"Li",
"Xue-Qian",
""
],
[
"Liu",
"Xiang",
""
],
[
"Ma",
"J. P.",
""
]
] | Recently the BES collaboration has announced observation of a resonant state in the $\pi^+\pi^- \eta'$ spectrum in $J/\psi \to \gamma \pi^+\pi^-\eta'$ decay. Fitting the data with a $0^{-+}$ state, the mass is determined to be 1833.7 MeV with $7.7\sigma$ statistic significance. This state is consistent with the one extracted from previously reported $p \bar p$ threshold enhancement data in $J/\psi \to \gamma p \bar p$. We study the properties of this state using QCD anomaly and QCD sum rules assuming X(1835) to be a pseudoscalar and show that it is consistent with data. We find that this state has a sizeable matrix element $<0|G\tilde G|G_p>$ leading to branching ratios of $(2.61\sim 7.37)\times 10^{-3}$ and $(2.21\sim 10.61)\times 10^{-2}$ for $J/\psi \to \gamma G_p$ and for $G_p \to \pi^+\pi^- \eta'$, respectively. Combining the calculated branching ratio of $J/\psi \to \gamma G_p$ and data on threshold enhancement in $J/\psi \to \gamma p \bar p$, we determine the coupling for $G_p- p-\bar p$ interaction. We finally study branching ratios of other $J/\psi \to \gamma + {three mesons}$ decay modes. We find that $J/\psi \to \gamma G_p \to \gamma (\pi^+\pi^- \eta, K K \pi^0)$ can provide useful tests for the mechanism proposed. |
2010.05464 | Jinmian Li | Jun Guo, Jinmian Li, Tianjun Li, Rao Zhang | The Boosted Higgs Jet Reconstruction via Graph Neural Network | 18 pages, 8 figures, version accepted for publication in PRD | Phys. Rev. D 103, 116025 (2021) | 10.1103/PhysRevD.103.116025 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | By representing each collider event as a point cloud, we adopt the Graphic
Convolutional Network (GCN) with focal loss to reconstruct the Higgs jet in it.
This method provides higher Higgs tagging efficiency and better reconstruction
accuracy than the traditional methods which use jet substructure information.
The GCN, which is trained on events of the $H$+jets process, is capable of
detecting a Higgs jet in events of several different processes, even though the
performance degrades when there are boosted heavy particles other than the
Higgs in the event. We also demonstrate the signal and background
discrimination capacity of the GCN by applying it to the $t\bar{t}$ process.
Taking the outputs of the network as new features to complement the traditional
jet substructure variables, the $t\bar{t}$ events can be separated further from
the $H$+jets events.
| [
{
"created": "Mon, 12 Oct 2020 05:43:40 GMT",
"version": "v1"
},
{
"created": "Wed, 9 Jun 2021 04:25:54 GMT",
"version": "v2"
}
] | 2021-07-07 | [
[
"Guo",
"Jun",
""
],
[
"Li",
"Jinmian",
""
],
[
"Li",
"Tianjun",
""
],
[
"Zhang",
"Rao",
""
]
] | By representing each collider event as a point cloud, we adopt the Graphic Convolutional Network (GCN) with focal loss to reconstruct the Higgs jet in it. This method provides higher Higgs tagging efficiency and better reconstruction accuracy than the traditional methods which use jet substructure information. The GCN, which is trained on events of the $H$+jets process, is capable of detecting a Higgs jet in events of several different processes, even though the performance degrades when there are boosted heavy particles other than the Higgs in the event. We also demonstrate the signal and background discrimination capacity of the GCN by applying it to the $t\bar{t}$ process. Taking the outputs of the network as new features to complement the traditional jet substructure variables, the $t\bar{t}$ events can be separated further from the $H$+jets events. |
hep-ph/0309082 | Luis Anchordoqui | Luis A. Anchordoqui, Jonathan L. Feng, Haim Goldberg, Alfred D.
Shapere | Quest for Black Holes and Superstring Excitations in Cosmic Ray Data | Talk given at the International Workshop on Particle Physics and the
Early Universe -COSMO 03- Ambleside, Lake District, U.K. (August 25-29, 2003)
Website at http://www.ippp.dur.ac.uk/cosmo03/ (reference added) | null | null | null | hep-ph astro-ph gr-qc hep-ex hep-th | null | In this talk we discuss aspects of TeV-scale gravitational collapse to black
holes and string balls and their subsequent evaporation. Special emphasis is
placed on the interplay of the string/black hole correspondence principle.
These ideas are then explored in the context of cosmic ray physics. First, the
potential for observing showers mediated by black holes or superstring
excitations is examined. Next, existing data from neutrino telescopes are used
to constrain the parameter space for the unseen dimensions of the universe.
Finally, we close with a discussion of future prospects.
| [
{
"created": "Tue, 9 Sep 2003 19:46:53 GMT",
"version": "v1"
},
{
"created": "Tue, 9 Sep 2003 22:17:20 GMT",
"version": "v2"
},
{
"created": "Wed, 24 Sep 2003 20:05:01 GMT",
"version": "v3"
},
{
"created": "Wed, 22 Oct 2003 20:44:26 GMT",
"version": "v4"
}
] | 2007-05-23 | [
[
"Anchordoqui",
"Luis A.",
""
],
[
"Feng",
"Jonathan L.",
""
],
[
"Goldberg",
"Haim",
""
],
[
"Shapere",
"Alfred D.",
""
]
] | In this talk we discuss aspects of TeV-scale gravitational collapse to black holes and string balls and their subsequent evaporation. Special emphasis is placed on the interplay of the string/black hole correspondence principle. These ideas are then explored in the context of cosmic ray physics. First, the potential for observing showers mediated by black holes or superstring excitations is examined. Next, existing data from neutrino telescopes are used to constrain the parameter space for the unseen dimensions of the universe. Finally, we close with a discussion of future prospects. |
1110.2483 | Stefano Forte | Richard D.Ball, Valerio Bertone, Luigi Del Debbio, Stefano Forte,
Alberto Guffanti, Jose I.Latorre, Simone Lionetti, Juan Rojo and Maria Ubiali | Precision NNLO determination of alpha_s(M_Z) using an unbiased global
parton set | 11 pages, 6 figures. Various small corrections and improvements: Chi2
values for PDF fits provided, discussion of pulls clarified. Final version,
to be published in Phys.Lett.B | null | 10.1016/j.physletb.2011.11.053 | CERN-PH-TH/2011-225; Edinburgh 2011/29; FR-PHENO-2011-018;
IFUM-985-FT; TTK-11-50 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We determine the strong coupling alpha_s at NNLO in perturbative QCD using
the global dataset input to the NNPDF2.1 NNLO parton fit: data from neutral and
charged current deep-inelastic scattering, Drell-Yan, vector boson production
and inclusive jets. We find alpha_s(M_Z)=0.1173+- 0.0007 (stat), where the
statistical uncertainty comes from the underlying data and uncertainties due to
the analysis procedure are negligible. We show that the distribution of alpha_s
values preferred by different experiments in the global fit is statistically
consistent, without need for rescaling uncertainties by a "tolerance" factor.
We show that if deep-inelastic data only are used, the best-fit value of
alpha_s is somewhat lower, but consistent within one sigma with the global
determination. We estimate the dominant theoretical uncertainty, from higher
orders corrections, to be Delta alpha_s (pert) ~ 0.0009.
| [
{
"created": "Tue, 11 Oct 2011 20:00:00 GMT",
"version": "v1"
},
{
"created": "Fri, 9 Dec 2011 12:15:22 GMT",
"version": "v2"
}
] | 2015-05-30 | [
[
"Ball",
"Richard D.",
""
],
[
"Bertone",
"Valerio",
""
],
[
"Del Debbio",
"Luigi",
""
],
[
"Forte",
"Stefano",
""
],
[
"Guffanti",
"Alberto",
""
],
[
"Latorre",
"Jose I.",
""
],
[
"Lionetti",
"Simone",
""
... | We determine the strong coupling alpha_s at NNLO in perturbative QCD using the global dataset input to the NNPDF2.1 NNLO parton fit: data from neutral and charged current deep-inelastic scattering, Drell-Yan, vector boson production and inclusive jets. We find alpha_s(M_Z)=0.1173+- 0.0007 (stat), where the statistical uncertainty comes from the underlying data and uncertainties due to the analysis procedure are negligible. We show that the distribution of alpha_s values preferred by different experiments in the global fit is statistically consistent, without need for rescaling uncertainties by a "tolerance" factor. We show that if deep-inelastic data only are used, the best-fit value of alpha_s is somewhat lower, but consistent within one sigma with the global determination. We estimate the dominant theoretical uncertainty, from higher orders corrections, to be Delta alpha_s (pert) ~ 0.0009. |
0906.2595 | Howard Baer | Howard Baer, Andrew D. Box and Heaya Summy | Mainly axion cold dark matter in the minimal supergravity model | 17 pages with 10 .eps figures; this version contains low resolution
figures; this version is slightly updated | JHEP 0908:080,2009 | 10.1088/1126-6708/2009/08/080 | null | hep-ph astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We examine the minimal supergravity (mSUGRA) model under the assumption that
the strong CP problem is solved by the Peccei-Quinn mechanism. In this case,
the relic dark matter (DM) abundance consists of three components: {\it i}).
cold axions, {\it ii}). warm axinos from neutralino decay, and {\it iii}). cold
or warm thermally produced axinos. To sustain a high enough re-heat temperature
(T_R\agt 10^6 GeV) for many baryogenesis mechanisms to function, we find that
the bulk of DM should consist of cold axions, while the admixture of cold and
warm axinos should be rather slight, with a very light axino of mass \sim 100
keV. For mSUGRA with mainly axion cold DM (CDM), the most DM-preferred
parameter space regions are precisely those which are least preferred in the
case of neutralino DM. Thus, rather different SUSY signatures are expected at
the LHC in the case of mSUGRA with mainly axion CDM, as compared to mSUGRA with
neutralino CDM.
| [
{
"created": "Mon, 15 Jun 2009 02:54:30 GMT",
"version": "v1"
},
{
"created": "Wed, 12 Aug 2009 20:09:26 GMT",
"version": "v2"
}
] | 2009-09-28 | [
[
"Baer",
"Howard",
""
],
[
"Box",
"Andrew D.",
""
],
[
"Summy",
"Heaya",
""
]
] | We examine the minimal supergravity (mSUGRA) model under the assumption that the strong CP problem is solved by the Peccei-Quinn mechanism. In this case, the relic dark matter (DM) abundance consists of three components: {\it i}). cold axions, {\it ii}). warm axinos from neutralino decay, and {\it iii}). cold or warm thermally produced axinos. To sustain a high enough re-heat temperature (T_R\agt 10^6 GeV) for many baryogenesis mechanisms to function, we find that the bulk of DM should consist of cold axions, while the admixture of cold and warm axinos should be rather slight, with a very light axino of mass \sim 100 keV. For mSUGRA with mainly axion cold DM (CDM), the most DM-preferred parameter space regions are precisely those which are least preferred in the case of neutralino DM. Thus, rather different SUSY signatures are expected at the LHC in the case of mSUGRA with mainly axion CDM, as compared to mSUGRA with neutralino CDM. |
hep-ph/0102228 | Masaki Yasue | Teruyuki Kitabayashi and Masaki Yasue | Large Mixing Angle MSW Solution in an SU(3)_LxU(1)_N Gauge Model with
Two-loop Radiative Mechanism | RevTex file, 10 pages including 1 eps figure, discussins on U_{e3}
added and typos error corrected, version to appear in Physics Letters B | Phys.Lett. B508 (2001) 85-95 | 10.1016/S0370-2693(01)00397-5 | TOKAI-HEP/TH-0102 | hep-ph | null | An SU(3)_L x U(1)_N gauge model, where E^{-i} (i=1,2,3) as heavy leptons are
placed in the third member of lepton triplets, is shown to provide the large
mixing angle (LMA) MSW solution to the solar neutrino problem. By introducing
approximate conservation of L_e-L_mu-L_tau (\equiv L') into the model, we have
estimated \Delta m_\odot^2 \sim \sqrt{2}\epsilon \Delta
m_{atm}^2m_{E^1}/(m_{E^2}+m_{E^3}), where \epsilon represents L'-breaking
effects and m_{E^i} is a mass of E^{-i}. Since \Delta m_{atm}^2 \sim 3 x
10^{-3} eV^2, the LMA solution is obtained for \epsilon\sim 0.01-0.1 in the
case of m_{E^1} \sim m_{E^{2,3}}. This mechanism utilizes two-loop radiative
mechanism, which contains a triplet version of the singly charged Zee boson,
h^+, given by \xi = (\xi^{++}, {\bar \xi}^+, h^+)^T. Almost bimaximal mixing is
dynamically realized by the approximate equality between the \xi-couplings of
the first family to the second and third families.
| [
{
"created": "Mon, 19 Feb 2001 11:45:26 GMT",
"version": "v1"
},
{
"created": "Tue, 20 Feb 2001 12:55:15 GMT",
"version": "v2"
},
{
"created": "Wed, 14 Mar 2001 14:32:22 GMT",
"version": "v3"
}
] | 2009-11-07 | [
[
"Kitabayashi",
"Teruyuki",
""
],
[
"Yasue",
"Masaki",
""
]
] | An SU(3)_L x U(1)_N gauge model, where E^{-i} (i=1,2,3) as heavy leptons are placed in the third member of lepton triplets, is shown to provide the large mixing angle (LMA) MSW solution to the solar neutrino problem. By introducing approximate conservation of L_e-L_mu-L_tau (\equiv L') into the model, we have estimated \Delta m_\odot^2 \sim \sqrt{2}\epsilon \Delta m_{atm}^2m_{E^1}/(m_{E^2}+m_{E^3}), where \epsilon represents L'-breaking effects and m_{E^i} is a mass of E^{-i}. Since \Delta m_{atm}^2 \sim 3 x 10^{-3} eV^2, the LMA solution is obtained for \epsilon\sim 0.01-0.1 in the case of m_{E^1} \sim m_{E^{2,3}}. This mechanism utilizes two-loop radiative mechanism, which contains a triplet version of the singly charged Zee boson, h^+, given by \xi = (\xi^{++}, {\bar \xi}^+, h^+)^T. Almost bimaximal mixing is dynamically realized by the approximate equality between the \xi-couplings of the first family to the second and third families. |
hep-ph/0501079 | Tsedenbaljir Enkhbat | K.S. Babu, Ts. Enkhbat (Oklahoma State University) and Biswarup
Mukhopadhyaya (Harish-Chandra Research Institute) | Split Supersymmetry from Anomalous U(1) | 20 pages in LaTeX, version published in NPHB | Nucl.Phys. B720 (2005) 47-63 | 10.1016/j.nuclphysb.2005.05.006 | OSU-HEP-05-01 | hep-ph | null | We present a scenario wherein the anomalous U(1) D-term of string origin
triggers supersymmetry breaking and generates naturally a Split Supersymmetry
spectrum. When the gaugino and the Higgsino masses (which are of the same order
of magnitude) are set at the TeV scale, we find the scalar masses to be in the
range (10^6 - 10^8) GeV. The U(1) D-term provides a small expansion parameter
which we use to explain the mass and mixing hierarchies of quarks and leptons.
Explicit models utilizing exact results of N = 1 suersymmetric gauge theories
consistent with anomaly constraints, fermion mass hierarchy, and supersymmetry
breaking are presented.
| [
{
"created": "Mon, 10 Jan 2005 22:09:56 GMT",
"version": "v1"
},
{
"created": "Fri, 19 Aug 2005 18:07:27 GMT",
"version": "v2"
}
] | 2009-11-11 | [
[
"Babu",
"K. S.",
"",
"Oklahoma State University"
],
[
"Enkhbat",
"Ts.",
"",
"Oklahoma State University"
],
[
"Mukhopadhyaya",
"Biswarup",
"",
"Harish-Chandra Research Institute"
]
] | We present a scenario wherein the anomalous U(1) D-term of string origin triggers supersymmetry breaking and generates naturally a Split Supersymmetry spectrum. When the gaugino and the Higgsino masses (which are of the same order of magnitude) are set at the TeV scale, we find the scalar masses to be in the range (10^6 - 10^8) GeV. The U(1) D-term provides a small expansion parameter which we use to explain the mass and mixing hierarchies of quarks and leptons. Explicit models utilizing exact results of N = 1 suersymmetric gauge theories consistent with anomaly constraints, fermion mass hierarchy, and supersymmetry breaking are presented. |
hep-ph/0202018 | Yangmz | Zheng-Tao Wei and Mao-Zhi Yang | The systematic study of $B\to \pi$ form factors in pQCD approach and its
reliability | 30 pages, latex, some typos corrected, to appear in Nucl. Phys. B | Nucl.Phys. B642 (2002) 263-289 | 10.1016/S0550-3213(02)00623-5 | BIHEP-TH-2002-9 | hep-ph | null | The study of exclusive B decays in perturbative QCD are complicated by the
endpoint problem. In order to perform the perturbative calculation, the Sudakov
effects are introduced to regulate the endpoint singularity. We provide a
systematic analysis with leading and next-to-leading twist corrections for
$B\to\pi$ form factors in pQCD approach. The intrinsic transverse momentum
dependence of hadronic wave function and threshold resummation effects are
included in pQCD approach. There are two leading twist B meson distribution
amplitudes (or generally wave functions) in general. The QCD equations of
motion provide important constraints on B meson wave functions. The reliability
of pQCD approach in \bpi form factors is discussed. 70% of the result comes
from the region $\alpha_s(t)/\pi<0.2$ and 38% comes from the region where the
momentum transfer $t\geq 1\GeV$. The conceptual problems of pQCD approach are
discussed in brief. Our conclusion is that pQCD approach in the present form
cannot provide a precise prediction for \bpi transition form factors.
| [
{
"created": "Mon, 4 Feb 2002 10:18:17 GMT",
"version": "v1"
},
{
"created": "Wed, 26 Jun 2002 10:56:31 GMT",
"version": "v2"
},
{
"created": "Mon, 2 Sep 2002 08:04:19 GMT",
"version": "v3"
}
] | 2009-11-07 | [
[
"Wei",
"Zheng-Tao",
""
],
[
"Yang",
"Mao-Zhi",
""
]
] | The study of exclusive B decays in perturbative QCD are complicated by the endpoint problem. In order to perform the perturbative calculation, the Sudakov effects are introduced to regulate the endpoint singularity. We provide a systematic analysis with leading and next-to-leading twist corrections for $B\to\pi$ form factors in pQCD approach. The intrinsic transverse momentum dependence of hadronic wave function and threshold resummation effects are included in pQCD approach. There are two leading twist B meson distribution amplitudes (or generally wave functions) in general. The QCD equations of motion provide important constraints on B meson wave functions. The reliability of pQCD approach in \bpi form factors is discussed. 70% of the result comes from the region $\alpha_s(t)/\pi<0.2$ and 38% comes from the region where the momentum transfer $t\geq 1\GeV$. The conceptual problems of pQCD approach are discussed in brief. Our conclusion is that pQCD approach in the present form cannot provide a precise prediction for \bpi transition form factors. |
1006.3636 | George Lazarides | George Lazarides | The Standard-smooth Variant of Hybrid Inflation | 10 pages including 1 figure, uses aipproc.cls, talk given at the
BUE,CTP International Conference on Neutrino Physics in the LHC Era, Luxor,
Egypt, 15-19 November 2009 (to appear in the proceedings) | null | null | UT-STPD-1/10 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider the extension of the supersymmetric Pati-Salam model introduced
in order to solve the b-quark mass problem in supersymmetric theories with
Yukawa unification, universal boundary conditions and mu>0. This model
naturally leads to the new shifted and new smooth hybrid inflation scenarios,
which, however, yield, in minimal supergravity, too large values of the
spectral index n_s. We show that this problem can also be resolved within the
same model by a two-stage inflationary scenario based only on renormalizable
superpotential interactions. The first stage is of the standard and the second
of the new smooth hybrid type. The cosmological scales exit the horizon during
the first stage of inflation and acceptable n_s's can be achieved by
restricting the number of e-foldings of our present horizon during this
inflationary stage. The additional e-foldings needed for solving the horizon
and flatness problems are naturally provided by the second stage of inflation.
Monopoles are formed at the end of the first stage of inflation and are,
subsequently, diluted by the second stage of inflation so that their density in
the present universe is utterly negligible.
| [
{
"created": "Fri, 18 Jun 2010 08:44:42 GMT",
"version": "v1"
}
] | 2010-06-21 | [
[
"Lazarides",
"George",
""
]
] | We consider the extension of the supersymmetric Pati-Salam model introduced in order to solve the b-quark mass problem in supersymmetric theories with Yukawa unification, universal boundary conditions and mu>0. This model naturally leads to the new shifted and new smooth hybrid inflation scenarios, which, however, yield, in minimal supergravity, too large values of the spectral index n_s. We show that this problem can also be resolved within the same model by a two-stage inflationary scenario based only on renormalizable superpotential interactions. The first stage is of the standard and the second of the new smooth hybrid type. The cosmological scales exit the horizon during the first stage of inflation and acceptable n_s's can be achieved by restricting the number of e-foldings of our present horizon during this inflationary stage. The additional e-foldings needed for solving the horizon and flatness problems are naturally provided by the second stage of inflation. Monopoles are formed at the end of the first stage of inflation and are, subsequently, diluted by the second stage of inflation so that their density in the present universe is utterly negligible. |
hep-ph/9407224 | Jean Marc Richard | Jean-Marc Richard (Grenoble) | Hadrons with Two Heavy Quarks | Talk given at the CHARM 2000 Workshop, Fermilab, June 1994 to appear
in the Proceedings Latex, style file "charm2000" appended | null | null | null | hep-ph | null | We review the spectroscopy and some properties of hadrons containing two
charmed quarks, or more generally, two heavy quarks. This includes heavy
baryons such as $(bcu)$, and possible exotic multiquark states.
| [
{
"created": "Tue, 5 Jul 1994 10:56:52 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Richard",
"Jean-Marc",
"",
"Grenoble"
]
] | We review the spectroscopy and some properties of hadrons containing two charmed quarks, or more generally, two heavy quarks. This includes heavy baryons such as $(bcu)$, and possible exotic multiquark states. |
0809.2614 | Jae-hyeon Park | Jae-hyeon Park (INFN Padova) and Masahiro Yamaguchi (Tohoku
University) | B_s mixing phase and lepton flavor violation in supersymmetric SU(5) | 11 pages, updated using phi_s from HFAG, conclusion unchanged | Phys.Lett.B670:356-362,2009 | 10.1016/j.physletb.2008.11.023 | TU-813 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We inspect consequences of the latest B_s mixing phase measurements on lepton
flavor violation in a supersymmetric SU(5) theory. The O(1) phase, preferring a
non-vanishing squark mixing, generically implies tau -> (e + mu) gamma and mu
-> e gamma. Depending on the gaugino and the scalar mass parameters as well as
tan beta, the rates turn out to be detectable or even already excessive, if the
RR mass insertion of down-type squarks is nonzero. We find that it becomes easy
to reconcile B_s mixing phase with lepton flavor violation given: gaugino to
scalar squared mass ratio around 1/12, both LL and RR insertions with decent
sizes, and low tan beta.
| [
{
"created": "Mon, 15 Sep 2008 20:34:50 GMT",
"version": "v1"
},
{
"created": "Sun, 28 Sep 2008 23:47:10 GMT",
"version": "v2"
}
] | 2009-01-16 | [
[
"Park",
"Jae-hyeon",
"",
"INFN Padova"
],
[
"Yamaguchi",
"Masahiro",
"",
"Tohoku\n University"
]
] | We inspect consequences of the latest B_s mixing phase measurements on lepton flavor violation in a supersymmetric SU(5) theory. The O(1) phase, preferring a non-vanishing squark mixing, generically implies tau -> (e + mu) gamma and mu -> e gamma. Depending on the gaugino and the scalar mass parameters as well as tan beta, the rates turn out to be detectable or even already excessive, if the RR mass insertion of down-type squarks is nonzero. We find that it becomes easy to reconcile B_s mixing phase with lepton flavor violation given: gaugino to scalar squared mass ratio around 1/12, both LL and RR insertions with decent sizes, and low tan beta. |
hep-ph/0508286 | Tatsuo Kobayashi | Tatsuo Kobayashi and Carlos Munoz | More about soft terms and FCNC in realistic string constructions | 14 pages, latex. Misprints corrected | JHEP 0601 (2006) 044 | 10.1088/1126-6708/2006/01/044 | KUNS-1984, KAIST-TH 2005/13, FTUAM 05/11, IFT-UAM/CSIC-05-32 | hep-ph hep-th | null | In realistic four-dimensional string constructions the presence of anomalous
U(1)'s is generic. In addition, the associated Fayet-Iliopoulos contribution to
the D-term can break the extra gauge symmetries. As a consequence, physical
particles can appear combined with other states. We show that even if a
three-generation standard-like model has originally flavour-independent soft
scalar masses, the particle mixing contribution may generate non-universality
among them. Thus FCNC effects which were apparently absent reappear. We also
discuss the size of these contributions in an explicit model, and how they can
be suppressed.
| [
{
"created": "Mon, 29 Aug 2005 06:20:12 GMT",
"version": "v1"
},
{
"created": "Mon, 17 Oct 2005 23:14:42 GMT",
"version": "v2"
}
] | 2009-11-11 | [
[
"Kobayashi",
"Tatsuo",
""
],
[
"Munoz",
"Carlos",
""
]
] | In realistic four-dimensional string constructions the presence of anomalous U(1)'s is generic. In addition, the associated Fayet-Iliopoulos contribution to the D-term can break the extra gauge symmetries. As a consequence, physical particles can appear combined with other states. We show that even if a three-generation standard-like model has originally flavour-independent soft scalar masses, the particle mixing contribution may generate non-universality among them. Thus FCNC effects which were apparently absent reappear. We also discuss the size of these contributions in an explicit model, and how they can be suppressed. |
1712.07295 | Li-Ye Xiao | Li-Ye Xiao, Qi-Fang L\"u and Shi-Lin Zhu | Strong decays of the 1P and 2D doubly charmed states | 12 pages,7 figures | Phys. Rev. D 97, 074005 (2018) | 10.1103/PhysRevD.97.074005 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We perform a systematical investigation of the strong decay properties of the
low-lying $1P$- and $2D$-wave doubly charmed baryons with the $^3P_0$ quark
pair creation model. The main predictions include: (i) in the $\Xi_{cc}$ and
$\Omega_{cc}$ family, the $1P~\rho$ mode excitations with $J^P=1/2^-$ and
$3/2^-$ should be the fairly narrow states. (ii) For the $1P~\lambda$ mode
excitations, $|^2P_{\lambda}\frac{3}{2}^-\rangle$ and
$|^4P_{\lambda}\frac{3}{2}^-\rangle$ have a width of $\Gamma\sim150$ MeV, and
mainly decay into the $J^P=3/2^+$ ground state. Meanwhile,
$|^2P_{\lambda}\frac{1}{2}^-\rangle$ and $|^4P_{\lambda}\frac{5}{2}^-\rangle$
are the narrow states with a width of $\Gamma\sim40$ MeV, and mainly decay into
the ground state with $J^P=1/2^+$. (iii) The $2D_{\rho\rho}$ states mainly
decay via emitting a heavy-light meson if their masses are above the threshold
of $\Lambda_cD$ or $\Xi_cD$, respectively. Their strong decay widths are
sensitive to the masses and can reach several tens MeV. (iv) The
$2D_{\lambda\lambda}$ states may be broad states with a width of $\Gamma>100$
MeV. It should be emphasized that the states with $J^P=3/2^+$ and $5/2^+$
mainly decay into the ground state with $J^P=3/2^+$ plus a light-flavor meson,
while the states with $J^P=1/2^+$ and $7/2^+$ mainly decay into the ground
state with $J^P=1/2^+$ plus a light-flavor meson.
| [
{
"created": "Wed, 20 Dec 2017 02:51:14 GMT",
"version": "v1"
}
] | 2018-04-11 | [
[
"Xiao",
"Li-Ye",
""
],
[
"Lü",
"Qi-Fang",
""
],
[
"Zhu",
"Shi-Lin",
""
]
] | We perform a systematical investigation of the strong decay properties of the low-lying $1P$- and $2D$-wave doubly charmed baryons with the $^3P_0$ quark pair creation model. The main predictions include: (i) in the $\Xi_{cc}$ and $\Omega_{cc}$ family, the $1P~\rho$ mode excitations with $J^P=1/2^-$ and $3/2^-$ should be the fairly narrow states. (ii) For the $1P~\lambda$ mode excitations, $|^2P_{\lambda}\frac{3}{2}^-\rangle$ and $|^4P_{\lambda}\frac{3}{2}^-\rangle$ have a width of $\Gamma\sim150$ MeV, and mainly decay into the $J^P=3/2^+$ ground state. Meanwhile, $|^2P_{\lambda}\frac{1}{2}^-\rangle$ and $|^4P_{\lambda}\frac{5}{2}^-\rangle$ are the narrow states with a width of $\Gamma\sim40$ MeV, and mainly decay into the ground state with $J^P=1/2^+$. (iii) The $2D_{\rho\rho}$ states mainly decay via emitting a heavy-light meson if their masses are above the threshold of $\Lambda_cD$ or $\Xi_cD$, respectively. Their strong decay widths are sensitive to the masses and can reach several tens MeV. (iv) The $2D_{\lambda\lambda}$ states may be broad states with a width of $\Gamma>100$ MeV. It should be emphasized that the states with $J^P=3/2^+$ and $5/2^+$ mainly decay into the ground state with $J^P=3/2^+$ plus a light-flavor meson, while the states with $J^P=1/2^+$ and $7/2^+$ mainly decay into the ground state with $J^P=1/2^+$ plus a light-flavor meson. |
0810.3607 | V Braguta | V.V. Braguta, A.K. Likhoded, A.V. Luchinsky | Leading twist distribution amplitudes of P-wave nonrelativistic mesons | 9 pages, minor corrections, reference updated, version to be
published in Phys. Rev. D | Phys.Rev.D79:074004,2009 | 10.1103/PhysRevD.79.074004 | null | hep-ph | http://creativecommons.org/licenses/by/3.0/ | This paper is devoted to the study of the leading twist distribution
amplitudes of P-wave nonrelativistic mesons. It is shown that at the leading
order approximation in relative velocity of quark-antiquark pair inside the
mesons these distribution amplitudes can be expressed through one universal
function. As an example, the distribution amplitudes of the P-wave charmonia
mesons are considered. Within QCD sum rules the model for the universal
function of P-wave charmonia mesons is built. In addition, it is found the
relations between the moments of the universal function and the nonrelativistic
QCD matrix elements that control relativistic corrections to any amplitude
involving P-wave charmonia. Our calculation shows that characteristic size of
these corrections is of order of ~30 %.
| [
{
"created": "Mon, 20 Oct 2008 17:05:06 GMT",
"version": "v1"
},
{
"created": "Fri, 20 Mar 2009 06:58:58 GMT",
"version": "v2"
}
] | 2009-04-22 | [
[
"Braguta",
"V. V.",
""
],
[
"Likhoded",
"A. K.",
""
],
[
"Luchinsky",
"A. V.",
""
]
] | This paper is devoted to the study of the leading twist distribution amplitudes of P-wave nonrelativistic mesons. It is shown that at the leading order approximation in relative velocity of quark-antiquark pair inside the mesons these distribution amplitudes can be expressed through one universal function. As an example, the distribution amplitudes of the P-wave charmonia mesons are considered. Within QCD sum rules the model for the universal function of P-wave charmonia mesons is built. In addition, it is found the relations between the moments of the universal function and the nonrelativistic QCD matrix elements that control relativistic corrections to any amplitude involving P-wave charmonia. Our calculation shows that characteristic size of these corrections is of order of ~30 %. |
2202.13283 | Guy F. de T\'eramond | Stanley J. Brodsky and Guy F. de Teramond | Onset of color transparency in holographic light-front QCD | 19 pages, 3 figures, contributed to the MDPI special issue for the
special issue "The Future of Color Transparency, Hadronization and
Short-Range Nucleon-Nucleon Correlation Studies" | Physics 4, 633 (2022) | 10.3390/physics4020042 | SLAC-PUB-17656 | hep-ph nucl-ex nucl-th | http://creativecommons.org/licenses/by/4.0/ | The color transparency (CT) of a hadron, propagating with reduced absorption
in a nucleus, is a fundamental property of QCD (quantum chromodynamics)
reflecting its internal structure and effective size when it is produced at
high transverse momentum, $Q$. CT has been confirmed in many experiments, such
as semi-exclusive hard electroproduction, $e A \to e' \pi X$ for mesons
produced at $Q^2 > 3 ~ {\rm GeV}^2$. However, a recent JLab (Jefferson
Laboratory) measurement for a proton electroproduced in carbon $e\, {\rm C}\to
e' p X$, where $X$ stands for the inclusive sum of all produced final states,
fails to observe CT at $Q^2$ up to 14.2 GeV$^2$. In this paper, the onset of CT
is determined by comparing the $Q^2$-dependence of the hadronic cross sections
for the initial formation of a small color-singlet configuration using the
generalized parton distributions from holographic light-front QCD. A critical
dependence on the hadron's twist, $\tau$, the number of hadron constituents, is
found for the onset of CT, with no significant effects from the nuclear medium.
This effect can explain the absence of proton CT in the present kinematic range
of the JLab experiment. The proton is predicted to have a "two-stage" color
transparency with the onset of CT differing for the spin-conserving (twist-3,
$\tau=3$) Dirac form factor with a higher onset in $Q^2$ for the spin-flip
Pauli (twist-4) form factor. In contrast, the neutron is predicted to have a
"one-stage" color transparency with the onset at higher $Q^2$ because of the
dominance of its Pauli form factor. The model also predicts a strong dependence
at low energies on the flavor of the quark current coupling to the hadron.
| [
{
"created": "Sun, 27 Feb 2022 03:40:29 GMT",
"version": "v1"
},
{
"created": "Thu, 3 Mar 2022 17:19:29 GMT",
"version": "v2"
},
{
"created": "Wed, 11 May 2022 03:03:51 GMT",
"version": "v3"
},
{
"created": "Wed, 1 Jun 2022 02:23:53 GMT",
"version": "v4"
}
] | 2022-06-02 | [
[
"Brodsky",
"Stanley J.",
""
],
[
"de Teramond",
"Guy F.",
""
]
] | The color transparency (CT) of a hadron, propagating with reduced absorption in a nucleus, is a fundamental property of QCD (quantum chromodynamics) reflecting its internal structure and effective size when it is produced at high transverse momentum, $Q$. CT has been confirmed in many experiments, such as semi-exclusive hard electroproduction, $e A \to e' \pi X$ for mesons produced at $Q^2 > 3 ~ {\rm GeV}^2$. However, a recent JLab (Jefferson Laboratory) measurement for a proton electroproduced in carbon $e\, {\rm C}\to e' p X$, where $X$ stands for the inclusive sum of all produced final states, fails to observe CT at $Q^2$ up to 14.2 GeV$^2$. In this paper, the onset of CT is determined by comparing the $Q^2$-dependence of the hadronic cross sections for the initial formation of a small color-singlet configuration using the generalized parton distributions from holographic light-front QCD. A critical dependence on the hadron's twist, $\tau$, the number of hadron constituents, is found for the onset of CT, with no significant effects from the nuclear medium. This effect can explain the absence of proton CT in the present kinematic range of the JLab experiment. The proton is predicted to have a "two-stage" color transparency with the onset of CT differing for the spin-conserving (twist-3, $\tau=3$) Dirac form factor with a higher onset in $Q^2$ for the spin-flip Pauli (twist-4) form factor. In contrast, the neutron is predicted to have a "one-stage" color transparency with the onset at higher $Q^2$ because of the dominance of its Pauli form factor. The model also predicts a strong dependence at low energies on the flavor of the quark current coupling to the hadron. |
2005.08590 | Zhi-Hui Wang | Zhi-Hui Wang, Yi Zhang, Tian-hong Wang, Yue Jiang, Guo-Li Wang | The weak decay $B_c$ to $Z(3930)$ and $X(4160)$ by Bethe-Salpeter method | arXiv admin note: substantial text overlap with arXiv:1605.09091 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Considering $Z(3930)$ and $X(4160)$ as $\chi_{c2}(2P)$ and $\chi_{c2}(3P)$
states, the semileptonic and nonleptonic of $B_c$ decays to $Z(3930)$ and
$X(4160)$ are studied by the improved Bethe-Salpeter(B-S) Method. The form
factors of decay are calculated through the overlap integrals of the meson wave
functions in the whole accessible kinematical range. The influence of
relativistic corrections are considered in the exclusive decays. Branching
ratios of $B_c$ weak decays to $Z(3930)$ and $X(4160)$ are predicted. Some of
the branching ratios are: $Br(B_c^+\to
Z(3930)e^+\nu_e)$$=(3.03^{+0.09}_{-0.16})\times 10^{-4}$ and $Br(B_c^+\to
X(4160)e^+\nu_e)$$=(3.55^{+0.83}_{-0.35})\times 10^{-6}$. These results may
provide useful information to discover $Z(3930)$ and $X(4160)$ and the
necessary information for the phenomenological study of $B_c$ physics.
| [
{
"created": "Mon, 18 May 2020 11:04:55 GMT",
"version": "v1"
},
{
"created": "Mon, 10 Aug 2020 00:43:44 GMT",
"version": "v2"
}
] | 2020-08-11 | [
[
"Wang",
"Zhi-Hui",
""
],
[
"Zhang",
"Yi",
""
],
[
"Wang",
"Tian-hong",
""
],
[
"Jiang",
"Yue",
""
],
[
"Wang",
"Guo-Li",
""
]
] | Considering $Z(3930)$ and $X(4160)$ as $\chi_{c2}(2P)$ and $\chi_{c2}(3P)$ states, the semileptonic and nonleptonic of $B_c$ decays to $Z(3930)$ and $X(4160)$ are studied by the improved Bethe-Salpeter(B-S) Method. The form factors of decay are calculated through the overlap integrals of the meson wave functions in the whole accessible kinematical range. The influence of relativistic corrections are considered in the exclusive decays. Branching ratios of $B_c$ weak decays to $Z(3930)$ and $X(4160)$ are predicted. Some of the branching ratios are: $Br(B_c^+\to Z(3930)e^+\nu_e)$$=(3.03^{+0.09}_{-0.16})\times 10^{-4}$ and $Br(B_c^+\to X(4160)e^+\nu_e)$$=(3.55^{+0.83}_{-0.35})\times 10^{-6}$. These results may provide useful information to discover $Z(3930)$ and $X(4160)$ and the necessary information for the phenomenological study of $B_c$ physics. |
hep-ph/9712330 | Bernd Kniehl | A. Djouadi (U. Montpellier), P. Gambino (TU Munich), B.A. Kniehl (MPI
Munich) | Two-Loop Electroweak Heavy-Fermion Corrections to Higgs-Boson Production
and Decay | 29 pages (Latex), 3 figures (Postscript) | Nucl.Phys. B523 (1998) 17-39 | 10.1016/S0550-3213(98)00147-3 | PM 97/45, MPI/PhT/97-71, TUM-HEP-301/97 | hep-ph | null | The dominant electroweak corrections to the production cross sections and
partial decay widths of a light Standard-Model Higgs boson, with mass M_H <<
2m_t, are due to top-quark loops. By means of a low-energy theorem, we study at
the two-loop level the leading shifts in the Higgs-boson couplings to pairs of
light fermions and gauge bosons induced by a sequential isodoublet of high-mass
fermions. For tree-level and loop-induced Higgs-boson couplings, these
corrections are of relative orders O(G_mu^2 m_F^4) and O(G_mu m_F^2),
respectively, where m_F represents a generic heavy-fermion mass, with m_F >>
M_W, M_H. Except for the Hbb-bar coupling, all results carry over to the case
of the top-quark-induced corrections. We discuss possible phenomenological
consequences of our results.
| [
{
"created": "Wed, 10 Dec 1997 15:05:37 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Djouadi",
"A.",
"",
"U. Montpellier"
],
[
"Gambino",
"P.",
"",
"TU Munich"
],
[
"Kniehl",
"B. A.",
"",
"MPI\n Munich"
]
] | The dominant electroweak corrections to the production cross sections and partial decay widths of a light Standard-Model Higgs boson, with mass M_H << 2m_t, are due to top-quark loops. By means of a low-energy theorem, we study at the two-loop level the leading shifts in the Higgs-boson couplings to pairs of light fermions and gauge bosons induced by a sequential isodoublet of high-mass fermions. For tree-level and loop-induced Higgs-boson couplings, these corrections are of relative orders O(G_mu^2 m_F^4) and O(G_mu m_F^2), respectively, where m_F represents a generic heavy-fermion mass, with m_F >> M_W, M_H. Except for the Hbb-bar coupling, all results carry over to the case of the top-quark-induced corrections. We discuss possible phenomenological consequences of our results. |
hep-ph/0007047 | Daniel Boer | Daniel Boer (RIKEN-BNL Research Center) | Transversely polarized Lambda production | 4 pages, Latex, 3 Postscript figures; Talk presented at the 7th
Conference on Intersections of Particle and Nuclear Physics (CIPANP 2000),
Quebec City, Canada, May 2000 | AIP Conf.Proc. 549 (2002) 701-704 | 10.1063/1.1345350 | null | hep-ph | null | Transversely polarized Lambda production in hard scattering processes is
discussed in terms of a leading twist T-odd fragmentation function which
describes the fragmentation of an unpolarized quark into a transversely
polarized Lambda. We focus on the properties of this function and its relevance
for the RHIC and HERMES experiments.
| [
{
"created": "Wed, 5 Jul 2000 17:42:39 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Boer",
"Daniel",
"",
"RIKEN-BNL Research Center"
]
] | Transversely polarized Lambda production in hard scattering processes is discussed in terms of a leading twist T-odd fragmentation function which describes the fragmentation of an unpolarized quark into a transversely polarized Lambda. We focus on the properties of this function and its relevance for the RHIC and HERMES experiments. |
2110.02818 | Konstantin Asteriadis | Konstantin Asteriadis, Fabrizio Caola, Kirill Melnikov, Raoul
R\"ontsch | NNLO QCD corrections to weak boson fusion Higgs boson production in the
$H \to b\bar b$ and $H \to WW^* \to 4l$ decay channels | 30 pages, 7 figures | null | 10.1007/JHEP02(2022)046 | OUTP-21-23P, TTP21-032, P3H-21-066, CERN-TH-2021-146,
TIF-UNIMI-2021-15 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We compute the next-to-next-to-leading order QCD corrections to Higgs boson
production in weak boson fusion followed by its decay to a $b\bar b$ pair or to
a pair of leptonically-decaying $W$ bosons. Our calculation allows us to
compute realistic fiducial cross sections and assess the impact of fiducial
cuts applied to the Higgs boson decay products on the magnitude of QCD
radiative corrections in weak boson fusion.
| [
{
"created": "Wed, 6 Oct 2021 14:43:40 GMT",
"version": "v1"
}
] | 2022-02-23 | [
[
"Asteriadis",
"Konstantin",
""
],
[
"Caola",
"Fabrizio",
""
],
[
"Melnikov",
"Kirill",
""
],
[
"Röntsch",
"Raoul",
""
]
] | We compute the next-to-next-to-leading order QCD corrections to Higgs boson production in weak boson fusion followed by its decay to a $b\bar b$ pair or to a pair of leptonically-decaying $W$ bosons. Our calculation allows us to compute realistic fiducial cross sections and assess the impact of fiducial cuts applied to the Higgs boson decay products on the magnitude of QCD radiative corrections in weak boson fusion. |
hep-ph/9510290 | null | M. M. Block (Northwestern), A. R. White (Argonne), B. Margolis
(McGill) | The High Energy Behavior of the Forward Scattering Parameters---An
Amplitude Analysis Update | 7 pages in LaTeX, 4 figures and 5 files, uuencoded in file
"sigall.uu" | null | null | N.U.H.E.P. 490, September, 1995 | hep-ph | null | Utilizing the most recent experimental data, we reanalyze high energy \pbar p
and pp data, using the asymptotic amplitude analysis, under the assumption that
we have reached `asymptopia'. This analysis gives strong evidence for a $\log
\,(s/s_0)$ dependence at {\em current} energies and {\em not} $\log^2 (s/s_0)$,
and also demonstrates that odderons are {\em not} necessary to explain the
experimental data.
| [
{
"created": "Sat, 14 Oct 1995 00:30:55 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Block",
"M. M.",
"",
"Northwestern"
],
[
"White",
"A. R.",
"",
"Argonne"
],
[
"Margolis",
"B.",
"",
"McGill"
]
] | Utilizing the most recent experimental data, we reanalyze high energy \pbar p and pp data, using the asymptotic amplitude analysis, under the assumption that we have reached `asymptopia'. This analysis gives strong evidence for a $\log \,(s/s_0)$ dependence at {\em current} energies and {\em not} $\log^2 (s/s_0)$, and also demonstrates that odderons are {\em not} necessary to explain the experimental data. |
2208.06232 | Chun-Hao Lee | Chun-Hao Lee, Reinard Primulando, Martin Spinrath | Discovery prospects for heavy dark matter in KAGRA | 22 pages, 8 figures | Phys. Rev. D 107 (2023) 035029 | 10.1103/PhysRevD.107.035029 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss the discovery prospects for kg-scale dark matter with a
Yukawa-like long-range interaction in Kamioka Gravitational Wave Detector
(KAGRA). We consider the interaction range to be in the order of kilometers,
thus the dark matter may interact with multiple KAGRA mirrors simultaneously.
The induced signal strain is in many cases dominated by frequencies below about
130 Hz. Due to the geometry of the detector there is some strong directional
sensitivity. It turns out that KAGRA would be able to constrain such kind of
dark matter within a few years of operation. With our set of assumptions we
expect that KAGRA could detect a few events per year for 10 kg dark matter,
with a Yukawa interaction with a range of 10 km and an effective coupling
constant around $10^6$.
| [
{
"created": "Fri, 12 Aug 2022 11:54:26 GMT",
"version": "v1"
},
{
"created": "Sat, 4 Mar 2023 17:52:35 GMT",
"version": "v2"
}
] | 2023-03-07 | [
[
"Lee",
"Chun-Hao",
""
],
[
"Primulando",
"Reinard",
""
],
[
"Spinrath",
"Martin",
""
]
] | We discuss the discovery prospects for kg-scale dark matter with a Yukawa-like long-range interaction in Kamioka Gravitational Wave Detector (KAGRA). We consider the interaction range to be in the order of kilometers, thus the dark matter may interact with multiple KAGRA mirrors simultaneously. The induced signal strain is in many cases dominated by frequencies below about 130 Hz. Due to the geometry of the detector there is some strong directional sensitivity. It turns out that KAGRA would be able to constrain such kind of dark matter within a few years of operation. With our set of assumptions we expect that KAGRA could detect a few events per year for 10 kg dark matter, with a Yukawa interaction with a range of 10 km and an effective coupling constant around $10^6$. |
1404.5839 | Robert Schabinger | Ye Li, Andreas von Manteuffel, Robert M. Schabinger, and Hua Xing Zhu | N$^3$LO Higgs and Drell-Yan production at threshold: the one-loop
two-emission contribution | 19 pages, 1 figure. Version 2 is the final, published version of this
article | Phys. Rev. D 90, 053006 (2014) | 10.1103/PhysRevD.90.053006 | MITP/14-029, SLAC-PUB-15946 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper, we study phenomenologically interesting soft radiation
distributions in massless QCD. Specifically, we consider the emission of two
soft partons off of a pair of light-like Wilson lines, in either the
fundamental or the adjoint representation, at next-to-leading order. Our
results are an essential component of the next-to-next-to-next-to-leading order
threshold corrections to both Higgs boson production in the gluon fusion
channel and Drell-Yan lepton production. Our calculations are consistent with
the recently published results for Higgs boson production. As a non-trivial
cross-check on our analysis, we rederive a recent prediction for the Drell-Yan
threshold cross section using a completely different strategy. Our results are
compact, valid to all orders in the dimensional regularization parameter, and
expressed in terms of pure functions.
| [
{
"created": "Wed, 23 Apr 2014 14:39:12 GMT",
"version": "v1"
},
{
"created": "Sun, 14 Dec 2014 14:35:50 GMT",
"version": "v2"
}
] | 2014-12-16 | [
[
"Li",
"Ye",
""
],
[
"von Manteuffel",
"Andreas",
""
],
[
"Schabinger",
"Robert M.",
""
],
[
"Zhu",
"Hua Xing",
""
]
] | In this paper, we study phenomenologically interesting soft radiation distributions in massless QCD. Specifically, we consider the emission of two soft partons off of a pair of light-like Wilson lines, in either the fundamental or the adjoint representation, at next-to-leading order. Our results are an essential component of the next-to-next-to-next-to-leading order threshold corrections to both Higgs boson production in the gluon fusion channel and Drell-Yan lepton production. Our calculations are consistent with the recently published results for Higgs boson production. As a non-trivial cross-check on our analysis, we rederive a recent prediction for the Drell-Yan threshold cross section using a completely different strategy. Our results are compact, valid to all orders in the dimensional regularization parameter, and expressed in terms of pure functions. |
2104.10699 | Basabendu Barman | Basabendu Barman, Nicol\'as Bernal | Gravitational SIMPs | 27 pages, 5 figures, 1 table, version accepted in JCAP | null | 10.1088/1475-7516/2021/06/011 | PI/UAN-2021-688FT | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We study the impact of thermalization and number-changing processes in the
dark sector on the yield of gravitationally produced dark matter (DM). We take
into account the DM production through the $s$-channel exchange of a massless
graviton both from the scattering of inflatons during the reheating era, and
from the Standard Model bath via the UV freeze-in mechanism. By considering the
DM to be a scalar, a fermion, and a vector boson we show, in a
model-independent way, that DM self-interaction gives rise to a larger viable
parameter space by allowing lower reheating temperature to be compatible with
Planck observed relic abundance. As an example, we also discuss our findings in
the ontext of the $\mathbb{Z}_2$-symmetric scalar singlet DM model.
| [
{
"created": "Wed, 21 Apr 2021 18:00:37 GMT",
"version": "v1"
},
{
"created": "Wed, 26 May 2021 19:02:10 GMT",
"version": "v2"
}
] | 2021-06-23 | [
[
"Barman",
"Basabendu",
""
],
[
"Bernal",
"Nicolás",
""
]
] | We study the impact of thermalization and number-changing processes in the dark sector on the yield of gravitationally produced dark matter (DM). We take into account the DM production through the $s$-channel exchange of a massless graviton both from the scattering of inflatons during the reheating era, and from the Standard Model bath via the UV freeze-in mechanism. By considering the DM to be a scalar, a fermion, and a vector boson we show, in a model-independent way, that DM self-interaction gives rise to a larger viable parameter space by allowing lower reheating temperature to be compatible with Planck observed relic abundance. As an example, we also discuss our findings in the ontext of the $\mathbb{Z}_2$-symmetric scalar singlet DM model. |
1909.09879 | Dubravko Klabu\v{c}ar | Davor Horvati\'c, Dalibor Kekez and Dubravko Klabu\v{c}ar | Temperature Dependence of the Axion Mass in a Scenario Where the
Restoration of Chiral Symmetry Drives the Restoration of the $U_A(1)$
Symmetry | 23 pages, 7 figures, title changed, references added, minor style and
language changes, version published in Universe 5 (2019) no.10, 208, | Universe 5 (2019) no.10, 208 | 10.3390/universe5100208 | ZTF-EP-19-04 | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The temperature ($T$) dependence of the axion mass is predicted for $T$'s up
to $\sim 2.3 \times$ the chiral restoration temperature of QCD. The axion is
related to the $U_A(1)$ anomaly. The squared axion mass $m_a(T)^2$ is, modulo
the presently undetermined scale of spontaneous breaking of Peccei-Quinn
symmetry $f_a$ (squared), equal to QCD topological susceptibility $\chi(T)$ for
all $T$. We obtain $\chi(T)$ by using quark condensates calculated in two
effective Dyson-Schwinger models of nonperturbative QCD. They exhibit the
correct chiral behavior, including the dynamical breaking of chiral symmetry
and its restoration at high $T$. This is reflected in the $U_A(1)$ symmetry
breaking and restoration through $\chi(T)$. In our previous studies, such
$\chi(T)$ yields the $T$-dependence of the $U_A(1)$-anomaly-influenced masses
of $\eta'$ and $\eta$ mesons consistent with experiment. This in turn supports
our prediction for the $T$-dependence of the axion mass. Another support is a
rather good agreement with the pertinent lattice results. This agreement is not
spoiled by our varying $u$ and $d$ quark mass parameters out of the isospin
limit.
| [
{
"created": "Sat, 21 Sep 2019 19:40:20 GMT",
"version": "v1"
},
{
"created": "Mon, 28 Oct 2019 21:05:12 GMT",
"version": "v2"
}
] | 2019-10-30 | [
[
"Horvatić",
"Davor",
""
],
[
"Kekez",
"Dalibor",
""
],
[
"Klabučar",
"Dubravko",
""
]
] | The temperature ($T$) dependence of the axion mass is predicted for $T$'s up to $\sim 2.3 \times$ the chiral restoration temperature of QCD. The axion is related to the $U_A(1)$ anomaly. The squared axion mass $m_a(T)^2$ is, modulo the presently undetermined scale of spontaneous breaking of Peccei-Quinn symmetry $f_a$ (squared), equal to QCD topological susceptibility $\chi(T)$ for all $T$. We obtain $\chi(T)$ by using quark condensates calculated in two effective Dyson-Schwinger models of nonperturbative QCD. They exhibit the correct chiral behavior, including the dynamical breaking of chiral symmetry and its restoration at high $T$. This is reflected in the $U_A(1)$ symmetry breaking and restoration through $\chi(T)$. In our previous studies, such $\chi(T)$ yields the $T$-dependence of the $U_A(1)$-anomaly-influenced masses of $\eta'$ and $\eta$ mesons consistent with experiment. This in turn supports our prediction for the $T$-dependence of the axion mass. Another support is a rather good agreement with the pertinent lattice results. This agreement is not spoiled by our varying $u$ and $d$ quark mass parameters out of the isospin limit. |
hep-ph/0407045 | Johannes Bluemlein | J. Bl\"umlein and V. Ravindran | NNLO coefficient functions of Higgs and Drell--Yan cross sections in
Mellin space | 1 latex file, 1 style file, Contribution to the Proceedings of "Loops
and Legs in Quantum Field Theory 2004", Zinnowitz, Usedom Island, Germany,
April 2004 | null | 10.1016/j.nuclphysbps.2004.09.005 | DESY 04-115, SFB/CPP-04-24 | hep-ph hep-th | null | We calculate the Mellin moments of next-to-next-to-leading order coefficient
functions of the Drell-Yan and Higgs production cross sections. The results can
be expressed in term of finite harmonic sums which are maximally threefold up
to weight four. Various algebraic relations among these finite sums reduce the
complexity of the results suitable for fast numerical evaluations. It is shown
that only five non--trivial functions occur besides Euler's $\psi$--function in
the representation of these Wilson coefficients.
| [
{
"created": "Mon, 5 Jul 2004 15:16:52 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Blümlein",
"J.",
""
],
[
"Ravindran",
"V.",
""
]
] | We calculate the Mellin moments of next-to-next-to-leading order coefficient functions of the Drell-Yan and Higgs production cross sections. The results can be expressed in term of finite harmonic sums which are maximally threefold up to weight four. Various algebraic relations among these finite sums reduce the complexity of the results suitable for fast numerical evaluations. It is shown that only five non--trivial functions occur besides Euler's $\psi$--function in the representation of these Wilson coefficients. |
hep-ph/0001041 | Evgeny Akhmedov | E. Kh. Akhmedov | Seesaw mechanism and the neutrino mass matrix | LaTeX, 3 pages, no figures. Talk given at 6th International Workshop
on Topics in Astroparticle and Underground Physics (TAUP 99), September 6-10,
1999, Paris, France | Nucl.Phys.Proc.Suppl.87:321-323,2000 | 10.1016/S0920-5632(00)00692-7 | null | hep-ph astro-ph hep-ex | null | The seesaw mechanism of neutrino mass generation is analysed under the
following assumptions: (1) minimal seesaw with no Higgs triplets, (2)
hierarchical Dirac masses of neutrinos, (3) large lepton mixing primarily or
solely due to the mixing in the right-handed neutrino sector, and (4) unrelated
Dirac and Majorana sectors of neutrino masses. It is shown that large mixing
governing the dominant channel of the atmospheric neutrino oscillations can be
naturally obtained and that this constrained seesaw mechanism favours the
normal mass hierarchy for the light neutrinos leading to a small $U_{e3}$ entry
of the lepton mixing matrix and a mass scale of the lightest right handed
neutrino $M\simeq 10^{10} - 10^{11}$ GeV. Any of the three main neutrino
oscillation solutions to the solar neutrino problem can be accommodated. The
inverted mass hierarchy and quasi-degeneracy of neutrinos are disfavoured in
our scheme.
| [
{
"created": "Wed, 5 Jan 2000 19:42:10 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Akhmedov",
"E. Kh.",
""
]
] | The seesaw mechanism of neutrino mass generation is analysed under the following assumptions: (1) minimal seesaw with no Higgs triplets, (2) hierarchical Dirac masses of neutrinos, (3) large lepton mixing primarily or solely due to the mixing in the right-handed neutrino sector, and (4) unrelated Dirac and Majorana sectors of neutrino masses. It is shown that large mixing governing the dominant channel of the atmospheric neutrino oscillations can be naturally obtained and that this constrained seesaw mechanism favours the normal mass hierarchy for the light neutrinos leading to a small $U_{e3}$ entry of the lepton mixing matrix and a mass scale of the lightest right handed neutrino $M\simeq 10^{10} - 10^{11}$ GeV. Any of the three main neutrino oscillation solutions to the solar neutrino problem can be accommodated. The inverted mass hierarchy and quasi-degeneracy of neutrinos are disfavoured in our scheme. |
1305.2905 | Ibragim Alikhanov | I. Alikhanov | Do leptoquarks manifest themselves in ultra-high energy neutrino
interactions? | 14 pages, 5 figures. Version accepted for publication in JHEP | JHEP07(2013)093 | 10.1007/JHEP07(2013)093 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | It is assumed that neutrino-nucleon scattering at ultra-high energies
effectively proceeds through excitations of leptoquarks in neutrino-quark
subprocesses. This approach reproduces the behavior of the energy dependence of
the ultra-high energy neutrino-nucleon scattering cross sections and allows to
estimate masses as well as the decay widths of the involved leptoquarks. For
instance, this leads to the leptoquark mass $1353\pm230$ GeV in a way
independent on the leptoquark quantum numbers. The discovery potential of the
LHC for the leptoquarks is evaluated.
| [
{
"created": "Mon, 13 May 2013 19:54:49 GMT",
"version": "v1"
},
{
"created": "Wed, 22 May 2013 13:01:35 GMT",
"version": "v2"
},
{
"created": "Tue, 2 Jul 2013 16:51:27 GMT",
"version": "v3"
}
] | 2013-07-23 | [
[
"Alikhanov",
"I.",
""
]
] | It is assumed that neutrino-nucleon scattering at ultra-high energies effectively proceeds through excitations of leptoquarks in neutrino-quark subprocesses. This approach reproduces the behavior of the energy dependence of the ultra-high energy neutrino-nucleon scattering cross sections and allows to estimate masses as well as the decay widths of the involved leptoquarks. For instance, this leads to the leptoquark mass $1353\pm230$ GeV in a way independent on the leptoquark quantum numbers. The discovery potential of the LHC for the leptoquarks is evaluated. |
hep-ph/0209064 | Mario Everaldo de Souza | Mario Everaldo de Souza | Calculation of the energy levels and sizes of baryons with a noncentral
harmonic potential | 20 pages, Latex, presented at Hadron2002, submitted to EPJC | null | null | UFS-09-2002 | hep-ph hep-ex hep-th | null | It is considered that the effective interaction between any two quarks in a
baryon can be approximately described by a simple harmonic potential. Also, it
is made use of the nonrelativistic approximation. The problem is firstly solved
in Cartesian coordinates in order to find the energy levels irrespective of
their angular momenta and then it is also solved in polar cilindrical
coordinates for taking into account the angular momenta of the levels. The only
parameters used in the calculation are the constituent masses of quarks. By
making a comparison between the two solutions the energies and the
corresponding angular momenta (and parity) of almost all baryon levels are
described. The agreement with the experimental data is quite impressive. The
solution in Cartesian coordinates also produces some very important figures for
the sizes of baryons and for the harmonic oscillator constant which is clearly
related to confinement.
| [
{
"created": "Thu, 5 Sep 2002 19:37:10 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"de Souza",
"Mario Everaldo",
""
]
] | It is considered that the effective interaction between any two quarks in a baryon can be approximately described by a simple harmonic potential. Also, it is made use of the nonrelativistic approximation. The problem is firstly solved in Cartesian coordinates in order to find the energy levels irrespective of their angular momenta and then it is also solved in polar cilindrical coordinates for taking into account the angular momenta of the levels. The only parameters used in the calculation are the constituent masses of quarks. By making a comparison between the two solutions the energies and the corresponding angular momenta (and parity) of almost all baryon levels are described. The agreement with the experimental data is quite impressive. The solution in Cartesian coordinates also produces some very important figures for the sizes of baryons and for the harmonic oscillator constant which is clearly related to confinement. |
hep-ph/9204229 | null | Adam F. Falk, Matthias Neubert and Michael Luke | The Residual Mass Term in the Heavy Quark Effective Theory | 14 pages | Nucl.Phys.B388:363-375,1992 | 10.1016/0550-3213(92)90617-K | null | hep-ph | null | We reformulate the heavy quark effective theory in the presence of a residual
mass term, which has been taken to vanish in previous analyses. While such a
convention is permitted, the inclusion of a residual mass allows us to resolve
a potential ambiguity in the choice of the expansion parameter which defines
the effective theory. We show to subleading order in the mass expansion that
physical quantities computed in the effective theory do not depend on the
expansion parameter.
| [
{
"created": "Thu, 23 Apr 1992 01:22:00 GMT",
"version": "v1"
}
] | 2010-11-01 | [
[
"Falk",
"Adam F.",
""
],
[
"Neubert",
"Matthias",
""
],
[
"Luke",
"Michael",
""
]
] | We reformulate the heavy quark effective theory in the presence of a residual mass term, which has been taken to vanish in previous analyses. While such a convention is permitted, the inclusion of a residual mass allows us to resolve a potential ambiguity in the choice of the expansion parameter which defines the effective theory. We show to subleading order in the mass expansion that physical quantities computed in the effective theory do not depend on the expansion parameter. |
1309.7330 | Cheuk-Yin Wong | Cheuk-Yin Wong, Grzegorz Wilk | Relativistic Hard-Scattering and Tsallis Fits to pT Spectra in pp
Collisions at the LHC | 10 pages, 2 figures, presented at the Low-x Workshop, May 30 - June
4, 2013, Rehovot and Eilat, Israel | null | null | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Motivated by the good Tsallis fits to the high-pT spectra in pp collisions at
the LHC, we study the relativistic hard-scattering model and obtain an
approximate analytical expression for the differential hard-scattering cross
section at \eta ~ 0. The power-law behaviour of the transverse spectra, in the
form of d\sigma/dpT^2 \propto 1/pT^n, gives a power index n in the range of
4.5-5.5 for jet production as predicted by pQCD, after the dependencies of the
structure functions and the running coupling constant are properly taken into
account. The power indices for hadron production n are slightly greater than
those for jet production.
| [
{
"created": "Fri, 27 Sep 2013 18:49:14 GMT",
"version": "v1"
}
] | 2013-09-30 | [
[
"Wong",
"Cheuk-Yin",
""
],
[
"Wilk",
"Grzegorz",
""
]
] | Motivated by the good Tsallis fits to the high-pT spectra in pp collisions at the LHC, we study the relativistic hard-scattering model and obtain an approximate analytical expression for the differential hard-scattering cross section at \eta ~ 0. The power-law behaviour of the transverse spectra, in the form of d\sigma/dpT^2 \propto 1/pT^n, gives a power index n in the range of 4.5-5.5 for jet production as predicted by pQCD, after the dependencies of the structure functions and the running coupling constant are properly taken into account. The power indices for hadron production n are slightly greater than those for jet production. |
hep-ph/9811380 | Pierre Desgrolard | P. Desgrolard, A. Lengyel, E. Martynov | The proton structure function and a soft Regge Dipole Pomeron: a test
with recent data | 5 pages (LaTeX), 4 figures (Encapsulated PS) | null | null | LYCEN 98102 | hep-ph hep-ex | null | A recently published soft Regge Dipole Pomeron model intended for all $x$ and
$Q^2$ is proved to give a good agreement with (non fitted) recent HERA data
from ZEUS (SVX95) on the protonstructure function $F_2^p(x,Q^2)$ at low $Q^2$
and low $x$. The model also reproduces (without fit) the recently estimated
experimental derivatives ${\partial F_2^p\over\partial\ell n Q^2}$ and
${\partial \ell n F_2^p\over\partial\ell n (1/x)}$ in a wide $x$ and
$Q^2$-region.
| [
{
"created": "Wed, 18 Nov 1998 10:01:09 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Desgrolard",
"P.",
""
],
[
"Lengyel",
"A.",
""
],
[
"Martynov",
"E.",
""
]
] | A recently published soft Regge Dipole Pomeron model intended for all $x$ and $Q^2$ is proved to give a good agreement with (non fitted) recent HERA data from ZEUS (SVX95) on the protonstructure function $F_2^p(x,Q^2)$ at low $Q^2$ and low $x$. The model also reproduces (without fit) the recently estimated experimental derivatives ${\partial F_2^p\over\partial\ell n Q^2}$ and ${\partial \ell n F_2^p\over\partial\ell n (1/x)}$ in a wide $x$ and $Q^2$-region. |
1909.06202 | Arpan Das | Arpan Das, Hiranmaya Mishra, Ranjita K. Mohapatra | Transport coefficients of hot and dense hadron gas in a magnetic field:
a relaxation time approach | 22 pages, 11 figures. arXiv admin note: text overlap with
arXiv:1903.03938 | Phys. Rev. D 100, 114004 (2019) | 10.1103/PhysRevD.100.114004 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We estimate various transport coefficients of hot and dense hadronic matter
in the presence of magnetic field. The estimation is done through solutions of
the relativistic Boltzmann transport equation in the relaxation time
approximation.We have investigated the temperature and the baryon chemical
potential dependence of these transport coefficients. Explicit calculations are
done for the hadronic matter in the ambit of hadron resonance gas model. We
estimate thermal conductivity, electrical conductivity and the shear viscosity
of hadronic matter in the presence of a uniform magnetic field. Magnetic field,
in general, makes the transport coefficients anisotropic. It is also observed
that all the transport coefficients perpendicular to the magnetic field are
smaller compared to their isotropic counterpart.
| [
{
"created": "Thu, 12 Sep 2019 10:57:46 GMT",
"version": "v1"
}
] | 2019-12-11 | [
[
"Das",
"Arpan",
""
],
[
"Mishra",
"Hiranmaya",
""
],
[
"Mohapatra",
"Ranjita K.",
""
]
] | We estimate various transport coefficients of hot and dense hadronic matter in the presence of magnetic field. The estimation is done through solutions of the relativistic Boltzmann transport equation in the relaxation time approximation.We have investigated the temperature and the baryon chemical potential dependence of these transport coefficients. Explicit calculations are done for the hadronic matter in the ambit of hadron resonance gas model. We estimate thermal conductivity, electrical conductivity and the shear viscosity of hadronic matter in the presence of a uniform magnetic field. Magnetic field, in general, makes the transport coefficients anisotropic. It is also observed that all the transport coefficients perpendicular to the magnetic field are smaller compared to their isotropic counterpart. |
0709.4090 | Sergey Troshin | S.M. Troshin, N.E. Tyurin | Directed flow as effect of transient matter rotation in hadron and
nucleus collisions | 18 pages, 6 figures | Int.J.Mod.Phys.E17:1619-1633,2008 | 10.1142/S0218301308010489 | null | hep-ph | null | We discuss directed flow introduced for description of nucleus collisions and
consider its possible behavior in hadronic and nuclei reactions due to rotation
of the transient matter.
| [
{
"created": "Wed, 26 Sep 2007 07:21:38 GMT",
"version": "v1"
},
{
"created": "Fri, 2 Nov 2007 13:20:41 GMT",
"version": "v2"
},
{
"created": "Mon, 26 Nov 2007 08:52:16 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Troshin",
"S. M.",
""
],
[
"Tyurin",
"N. E.",
""
]
] | We discuss directed flow introduced for description of nucleus collisions and consider its possible behavior in hadronic and nuclei reactions due to rotation of the transient matter. |
1711.07349 | \"Ozen\c{c} G\"ung\"or | \"Ozen\c{c} G\"ung\"or, Bryan W. Lynn and Glenn D. Starkman | Global $SU(2)_L \otimes$BRST symmetry and its LSS theorem:
Ward-Takahashi identities governing Green's functions, on-shell T-Matrix
elements, and $V_{eff}$, in the scalar-sector of certain spontaneously broken
non-Abelian gauge theories | 39 pages, 2 figures. arXiv admin note: text overlap with
arXiv:1509.06471 | null | null | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This work is dedicated to the memory of Raymond Stora (1930-2015). $SU(2)_L$
is the simplest spontaneous symmetry breaking (SSB) non-Abelian gauge theory: a
complex scalar doublet $\phi=\frac{1}{\sqrt{2}}\begin{bmatrix}H+i\pi_3-\pi_2
+i\pi_1\end{bmatrix}\equiv\frac{1}{\sqrt{2}}\tilde{H}e^{2i\tilde{t}\cdot\tilde{\vec{\pi}}/<H>}\begin{bmatrix}10\end{bmatrix}$
and a vector $\vec{W}^\mu$. In Landau gauge, $\vec{W}^\mu$ is transverse,
$\vec{\tilde{\pi}}$ are massless derivatively coupled Nambu-Goldstone bosons
(NGB). A global shift symmetry enforces $m^{2}_{\tilde{\pi}}=0$. We observe
that on-shell T-matrix elements of physical states $\vec{W}^\mu$,$\phi$ are
independent of global $SU(2)_{L}$ transformations, and the associated global
current is exactly conserved for amplitudes of physical states. We identify two
towers of "1-soft-pion" global Ward-Takahashi Identities (WTI), which govern
the $\phi$-sector, and represent a new global symmetry, $SU(2)_L\otimes$BRST, a
symmetry not of the Lagrangian but of the physical states. The first gives
relations among 1-$\phi$-I (but one $W^{\mu},B^{\mu}$ reducible) off-shell
Green's functions, the second governs on-shell T-matrix elements, replacing the
Adler self-consistency conditions. These WTI constrain the all-loop-orders
scalar-sector effective Lagrangian and guarantee IR finiteness of the theory.
These on-shell WTI include a Lee-Stora-Symanzik (LSS) theorem, which enforces
the condition $m_{\pi}^2=0$ (far stronger than $m_{\tilde{\pi}}^2=0$) and
causes all relevant-operator contributions to the effective Lagrangian to
vanish exactly. The global $SU(2)_L$ and the BRST transformations commute in
$R_\xi$ gauges. With the on-shell T-matrix constraints, the physics therefore
has more symmetry than does its BRST invariant Lagrangian. We also show that
the statements made above hold for the electroweak sector of the Standard Model
bosons.
| [
{
"created": "Thu, 16 Nov 2017 20:34:08 GMT",
"version": "v1"
},
{
"created": "Fri, 16 Feb 2018 18:28:37 GMT",
"version": "v2"
},
{
"created": "Tue, 17 Apr 2018 19:25:44 GMT",
"version": "v3"
}
] | 2018-04-20 | [
[
"Güngör",
"Özenç",
""
],
[
"Lynn",
"Bryan W.",
""
],
[
"Starkman",
"Glenn D.",
""
]
] | This work is dedicated to the memory of Raymond Stora (1930-2015). $SU(2)_L$ is the simplest spontaneous symmetry breaking (SSB) non-Abelian gauge theory: a complex scalar doublet $\phi=\frac{1}{\sqrt{2}}\begin{bmatrix}H+i\pi_3-\pi_2 +i\pi_1\end{bmatrix}\equiv\frac{1}{\sqrt{2}}\tilde{H}e^{2i\tilde{t}\cdot\tilde{\vec{\pi}}/<H>}\begin{bmatrix}10\end{bmatrix}$ and a vector $\vec{W}^\mu$. In Landau gauge, $\vec{W}^\mu$ is transverse, $\vec{\tilde{\pi}}$ are massless derivatively coupled Nambu-Goldstone bosons (NGB). A global shift symmetry enforces $m^{2}_{\tilde{\pi}}=0$. We observe that on-shell T-matrix elements of physical states $\vec{W}^\mu$,$\phi$ are independent of global $SU(2)_{L}$ transformations, and the associated global current is exactly conserved for amplitudes of physical states. We identify two towers of "1-soft-pion" global Ward-Takahashi Identities (WTI), which govern the $\phi$-sector, and represent a new global symmetry, $SU(2)_L\otimes$BRST, a symmetry not of the Lagrangian but of the physical states. The first gives relations among 1-$\phi$-I (but one $W^{\mu},B^{\mu}$ reducible) off-shell Green's functions, the second governs on-shell T-matrix elements, replacing the Adler self-consistency conditions. These WTI constrain the all-loop-orders scalar-sector effective Lagrangian and guarantee IR finiteness of the theory. These on-shell WTI include a Lee-Stora-Symanzik (LSS) theorem, which enforces the condition $m_{\pi}^2=0$ (far stronger than $m_{\tilde{\pi}}^2=0$) and causes all relevant-operator contributions to the effective Lagrangian to vanish exactly. The global $SU(2)_L$ and the BRST transformations commute in $R_\xi$ gauges. With the on-shell T-matrix constraints, the physics therefore has more symmetry than does its BRST invariant Lagrangian. We also show that the statements made above hold for the electroweak sector of the Standard Model bosons. |
hep-ph/0111208 | Sergei Fedorov | N.O. Agasian, S.M. Fedorov | Instanton IR stabilization in the nonperturbative confining vacuum | 10 pages, 4 figures; v2: minor corrections, to appear in JHEP | JHEP 0112:019,2001 | 10.1088/1126-6708/2001/12/019 | ITEP-PH-5/2001 | hep-ph hep-lat hep-th | null | The influence of nonperturbative fields on instantons in quantum
chromodynamics is studied. Nonperturbative vacuum is described in terms of
nonlocal gauge invariant vacuum averages of gluon field strength. Effective
action for instanton is derived in bilocal approximation and it is demonstrated
that stochastic background gluon fields are responsible for infra-red (IR)
stabilization of instantons. Dependence of characteristic instanton size on
gluon condensate and correlation length in nonperturbative vacuum is found. It
is shown that instanton size in QCD is of order of 0.25 fm. Comparison of
obtained instanton size distribution with lattice data is made.
| [
{
"created": "Fri, 16 Nov 2001 18:16:32 GMT",
"version": "v1"
},
{
"created": "Fri, 14 Dec 2001 12:07:53 GMT",
"version": "v2"
}
] | 2010-02-03 | [
[
"Agasian",
"N. O.",
""
],
[
"Fedorov",
"S. M.",
""
]
] | The influence of nonperturbative fields on instantons in quantum chromodynamics is studied. Nonperturbative vacuum is described in terms of nonlocal gauge invariant vacuum averages of gluon field strength. Effective action for instanton is derived in bilocal approximation and it is demonstrated that stochastic background gluon fields are responsible for infra-red (IR) stabilization of instantons. Dependence of characteristic instanton size on gluon condensate and correlation length in nonperturbative vacuum is found. It is shown that instanton size in QCD is of order of 0.25 fm. Comparison of obtained instanton size distribution with lattice data is made. |
2103.14495 | Tolga Altinoluk | Tolga Altinoluk, Cyrille Marquet, Pieter Taels | Low-$x$ improved TMD approach to the lepto- and hadroproduction of a
heavy-quark pair | 18 pages, 5 figures | null | 10.1007/JHEP06(2021)085 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study lepto- and hadroproduction of a heavy-quark pair in the ITMD
factorization framework for dilute-dense collisions. Due to the presence of a
nonzero quark mass and/or nonzero photon virtuality, new contributions appear
compared to the cases of photo- and hadroproduction of dijets, for which the
ITMD framework was originally derived. The extra terms are sensitive to gluons
that are not fully linearly polarized. At small $x$ those gluons emerge only
when saturation effects are taken into account, and in a proper way. As a
result, in linear small-$x$ frameworks where gluon are fully linearly
polarized, such contributions are absent. We show however that they are not
always negligible, even for large gluon transverse momentum, due to the
behavior of the off-shell hard factors.
| [
{
"created": "Fri, 26 Mar 2021 14:35:45 GMT",
"version": "v1"
}
] | 2021-06-30 | [
[
"Altinoluk",
"Tolga",
""
],
[
"Marquet",
"Cyrille",
""
],
[
"Taels",
"Pieter",
""
]
] | We study lepto- and hadroproduction of a heavy-quark pair in the ITMD factorization framework for dilute-dense collisions. Due to the presence of a nonzero quark mass and/or nonzero photon virtuality, new contributions appear compared to the cases of photo- and hadroproduction of dijets, for which the ITMD framework was originally derived. The extra terms are sensitive to gluons that are not fully linearly polarized. At small $x$ those gluons emerge only when saturation effects are taken into account, and in a proper way. As a result, in linear small-$x$ frameworks where gluon are fully linearly polarized, such contributions are absent. We show however that they are not always negligible, even for large gluon transverse momentum, due to the behavior of the off-shell hard factors. |
1703.09675 | Hajime Fukuda | Hajime Fukuda, Natsumi Nagata, Hidetoshi Otono and Satoshi Shirai | Higgsino Dark Matter or Not: Role of Disappearing Track Searches at the
LHC and Future Colliders | 7 pages, 3 figures | null | 10.1016/j.physletb.2018.03.088 | IPMU 17-0050, UT-17-11, KYUSHU-RCAPP-2017-03 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Higgsino in supersymmetric standard models is known to be a promising
candidate for dark matter in the Universe. Its phenomenological property is
strongly affected by the gaugino fraction in the Higgsino-like state. If this
is sizable, in other words, if gaugino masses are less than ${\cal O}(10)$ TeV,
we may probe the Higgsino dark matter in future non-accelerator experiments
such as dark matter direct searches and measurements of electric dipole
moments. On the other hand, if gauginos are much heavier, then it is hard to
search for Higgsino in these experiments. In this case, due to a lack of
gaugino components, the mass difference between the neutral and charged
Higgsinos is uniquely determined by electroweak interactions to be around $350$
MeV, which makes the heavier charged state rather long-lived, with a decay
length of about $1$ cm. In this letter, we argue that a charged particle with a
flight length of ${\cal O}(1)$ cm can be probed in disappearing-track searches
if we require only two hits in the pixel detector. Even in this case, we can
reduce background events with the help of the displaced-vertex reconstruction
technique. We study the prospects of this search strategy at the LHC and future
colliders for the Higgsino dark matter scenario. It is found that an almost
pure Higgsino is indeed within the reach of the future $33$ TeV collider
experiments. We then discuss that the interplay among collider and
non-accelerator experiments plays a crucial role in testing the Higgsino dark
matter scenarios. Our strategy for disappearing-track searches can also enlarge
the discovery potential of pure wino dark matter as well as other
electroweak-charged dark matter candidates.
| [
{
"created": "Tue, 28 Mar 2017 17:16:55 GMT",
"version": "v1"
}
] | 2018-04-11 | [
[
"Fukuda",
"Hajime",
""
],
[
"Nagata",
"Natsumi",
""
],
[
"Otono",
"Hidetoshi",
""
],
[
"Shirai",
"Satoshi",
""
]
] | Higgsino in supersymmetric standard models is known to be a promising candidate for dark matter in the Universe. Its phenomenological property is strongly affected by the gaugino fraction in the Higgsino-like state. If this is sizable, in other words, if gaugino masses are less than ${\cal O}(10)$ TeV, we may probe the Higgsino dark matter in future non-accelerator experiments such as dark matter direct searches and measurements of electric dipole moments. On the other hand, if gauginos are much heavier, then it is hard to search for Higgsino in these experiments. In this case, due to a lack of gaugino components, the mass difference between the neutral and charged Higgsinos is uniquely determined by electroweak interactions to be around $350$ MeV, which makes the heavier charged state rather long-lived, with a decay length of about $1$ cm. In this letter, we argue that a charged particle with a flight length of ${\cal O}(1)$ cm can be probed in disappearing-track searches if we require only two hits in the pixel detector. Even in this case, we can reduce background events with the help of the displaced-vertex reconstruction technique. We study the prospects of this search strategy at the LHC and future colliders for the Higgsino dark matter scenario. It is found that an almost pure Higgsino is indeed within the reach of the future $33$ TeV collider experiments. We then discuss that the interplay among collider and non-accelerator experiments plays a crucial role in testing the Higgsino dark matter scenarios. Our strategy for disappearing-track searches can also enlarge the discovery potential of pure wino dark matter as well as other electroweak-charged dark matter candidates. |
hep-ph/9403274 | Oleg Tarasov | D.J. Broadhurst, P.A. Baikov, V.A. Ilyin, J. Fleischer, O.V. Tarasov,
V.A. Smirnov | Two-Loop Gluon-Condensate Contributions To Heavy-Quark Current
Correlators: Exact Results And Approximations | 9 pages | Phys.Lett.B329:103-110,1994 | 10.1016/0370-2693(94)90524-X | OUT--4102--49, INP--94--1/323, BI--TP/94--02,PI--PhT/94--2 | hep-ph | null | The coefficient functions of the gluon condensate $<G^2>$, in the correlators
of heavy-quark vector, axial, scalar and pseudoscalar currents, are obtained
analytically, to two loops, for all values of $z=q^2/4m^2$. In the limiting
cases $z\to0$, $z\to1$, and $z\to-\infty$, comparisons are made with previous
partial results. Approximation methods, based on these limiting cases, are
critically assessed, with a view to three-loop work. High accuracy is achieved
using a few moments as input. A {\em single} moment, combined with only the
{\em leading} threshold and asymptotic behaviours, gives the two-loop
corrections to better than 1% in the next 10 moments. A two-loop fit to vector
data yields $<\frac{\alpha_{\rm s}}{\pi}G^2>\approx0.021$ GeV$^4$.
| [
{
"created": "Fri, 11 Mar 1994 16:49:02 GMT",
"version": "v1"
}
] | 2010-11-01 | [
[
"Broadhurst",
"D. J.",
""
],
[
"Baikov",
"P. A.",
""
],
[
"Ilyin",
"V. A.",
""
],
[
"Fleischer",
"J.",
""
],
[
"Tarasov",
"O. V.",
""
],
[
"Smirnov",
"V. A.",
""
]
] | The coefficient functions of the gluon condensate $<G^2>$, in the correlators of heavy-quark vector, axial, scalar and pseudoscalar currents, are obtained analytically, to two loops, for all values of $z=q^2/4m^2$. In the limiting cases $z\to0$, $z\to1$, and $z\to-\infty$, comparisons are made with previous partial results. Approximation methods, based on these limiting cases, are critically assessed, with a view to three-loop work. High accuracy is achieved using a few moments as input. A {\em single} moment, combined with only the {\em leading} threshold and asymptotic behaviours, gives the two-loop corrections to better than 1% in the next 10 moments. A two-loop fit to vector data yields $<\frac{\alpha_{\rm s}}{\pi}G^2>\approx0.021$ GeV$^4$. |
1803.03589 | Raghav Kunnawalkam Elayavalli | Yang-Ting Chien and Raghav Kunnawalkam Elayavalli | Probing heavy ion collisions using quark and gluon jet substructure | 36 pages, 20 figures | null | null | MIT-CTP 4947, WSU-HEP 1802 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the phenomenon of jet quenching utilizing quark and gluon jet
substructures as independent probes of heavy ion collisions. We exploit jet and
subjet features to highlight differences between quark and gluon jets in vacuum
and in a medium with the jet-quenching model implemented in JEWEL. We begin
with a physics-motivated, multivariate analysis of jet substructure observables
including the jet mass, the radial moments, the $p_T^D$ and the pixel
multiplicity. In comparison, we employ state-of-the-art image-recognition
techniques by training a deep convolutional neutral network on jet images. To
systematically extract jet substructure information, we introduce the
telescoping deconstruction framework exploiting subjet kinematics at multiple
angular scales. We draw connections to the soft-drop subjet distribution and
illuminate medium-induced jet modifications using Lund diagrams. We find that
the quark gluon discrimination performance worsens in heavy ion jets due to
significant soft event activity affecting the soft jet substructure. Our work
suggests a systematically improvable framework for studying modifications to
quark and gluon jet substructures and facilitating direct comparisons between
theoretical calculations, simulations and measurements in heavy ion collisions.
| [
{
"created": "Fri, 9 Mar 2018 16:30:18 GMT",
"version": "v1"
}
] | 2018-03-12 | [
[
"Chien",
"Yang-Ting",
""
],
[
"Elayavalli",
"Raghav Kunnawalkam",
""
]
] | We study the phenomenon of jet quenching utilizing quark and gluon jet substructures as independent probes of heavy ion collisions. We exploit jet and subjet features to highlight differences between quark and gluon jets in vacuum and in a medium with the jet-quenching model implemented in JEWEL. We begin with a physics-motivated, multivariate analysis of jet substructure observables including the jet mass, the radial moments, the $p_T^D$ and the pixel multiplicity. In comparison, we employ state-of-the-art image-recognition techniques by training a deep convolutional neutral network on jet images. To systematically extract jet substructure information, we introduce the telescoping deconstruction framework exploiting subjet kinematics at multiple angular scales. We draw connections to the soft-drop subjet distribution and illuminate medium-induced jet modifications using Lund diagrams. We find that the quark gluon discrimination performance worsens in heavy ion jets due to significant soft event activity affecting the soft jet substructure. Our work suggests a systematically improvable framework for studying modifications to quark and gluon jet substructures and facilitating direct comparisons between theoretical calculations, simulations and measurements in heavy ion collisions. |
0708.3790 | K. S. Babu | K. S. Babu (Oklahoma State University) and Ernest Ma (University of
California, Riverside) | Singlet fermion dark matter and electroweak baryogenesis with radiative
neutrino mass | 9 pages, no figures | Int.J.Mod.Phys.A23:1813-1819,2008 | 10.1142/S0217751X08040299 | OSU-HEP-07-03 and UCRHEP-T438 | hep-ph | null | The model of radiative neutrino mass with dark matter proposed by one of us
is extended to include a real singlet scalar field. There are then two
important new consequences. One is the realistic possibility of having the
lightest neutral singlet fermion (instead of the lightest neutral component of
the dark scalar doublet) as the dark matter of the Universe. The other is a
modification of the effective Higgs potential of the Standard Model, consistent
with electroweak baryogenesis.
| [
{
"created": "Tue, 28 Aug 2007 13:55:23 GMT",
"version": "v1"
},
{
"created": "Thu, 6 Sep 2007 13:41:15 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Babu",
"K. S.",
"",
"Oklahoma State University"
],
[
"Ma",
"Ernest",
"",
"University of\n California, Riverside"
]
] | The model of radiative neutrino mass with dark matter proposed by one of us is extended to include a real singlet scalar field. There are then two important new consequences. One is the realistic possibility of having the lightest neutral singlet fermion (instead of the lightest neutral component of the dark scalar doublet) as the dark matter of the Universe. The other is a modification of the effective Higgs potential of the Standard Model, consistent with electroweak baryogenesis. |
hep-ph/9510423 | Elaine Remillard | W.M. Kloet and F. Myhrer | An amplitude analysis of the $\overline{N}N \to \pi^- \pi^+$ reaction | 16 pages (revtex), 8 figures available on request, submitted to Phys.
Rev. D | Phys.Rev.D53:6120-6126,1996 | 10.1103/PhysRevD.53.6120 | RU9571 and USC(NT)-95-3 | hep-ph nucl-th | null | A simple partial wave amplitude analysis of $\overline{p}p \rightarrow \pi^-
\pi^+$ has been performed for data in the range p$_{\sl lab}$ = 360 -- 1000
MeV/c. Remarkably few partial waves are required to fit the data, while the
number of required $J$ values barely changes over this energy range. However,
the resulting set of partial wave amplitudes is not unique. We discuss possible
measurements with polarized beam and target which will severely restrict and
help resolve the present analysis ambiguities. New data from the reaction
$\overline{p}p \rightarrow \pi^0 \pi^0$ alone, are insufficient for that
purpose.
| [
{
"created": "Thu, 26 Oct 1995 19:34:29 GMT",
"version": "v1"
}
] | 2009-09-25 | [
[
"Kloet",
"W. M.",
""
],
[
"Myhrer",
"F.",
""
]
] | A simple partial wave amplitude analysis of $\overline{p}p \rightarrow \pi^- \pi^+$ has been performed for data in the range p$_{\sl lab}$ = 360 -- 1000 MeV/c. Remarkably few partial waves are required to fit the data, while the number of required $J$ values barely changes over this energy range. However, the resulting set of partial wave amplitudes is not unique. We discuss possible measurements with polarized beam and target which will severely restrict and help resolve the present analysis ambiguities. New data from the reaction $\overline{p}p \rightarrow \pi^0 \pi^0$ alone, are insufficient for that purpose. |
1005.4922 | Guidal | M. Guidal | Constraints on the $\tilde{H}$ Generalized Parton Distribution from Deep
Virtual Compton Scattering Measured at HERMES | 14 pages, 5 figures | Phys.Lett.B693:17-23,2010 | 10.1016/j.physletb.2010.07.059 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We have analyzed the longitudinally polarized proton target asymmetry data of
the Deep Virtual Compton process recently published by the HERMES collaboration
in terms of Generalized Parton Distributions. We have fitted these new data in
a largely model-independent fashion and the procedure results in numerical
constraints on the $\tilde{H}_\mathrm{Im}$ Compton Form Factor. We present its
$t-$ and $\xi-$ dependencies. We also find improvement on the determination of
two other Compton Form Factors, $H_\mathrm{Re}$ and $H_\mathrm{Im}$.
| [
{
"created": "Wed, 26 May 2010 19:52:59 GMT",
"version": "v1"
}
] | 2014-11-21 | [
[
"Guidal",
"M.",
""
]
] | We have analyzed the longitudinally polarized proton target asymmetry data of the Deep Virtual Compton process recently published by the HERMES collaboration in terms of Generalized Parton Distributions. We have fitted these new data in a largely model-independent fashion and the procedure results in numerical constraints on the $\tilde{H}_\mathrm{Im}$ Compton Form Factor. We present its $t-$ and $\xi-$ dependencies. We also find improvement on the determination of two other Compton Form Factors, $H_\mathrm{Re}$ and $H_\mathrm{Im}$. |
hep-ph/0108118 | A. A. Arkhipov | A.A.Arkhipov | Proton-Proton Total Cross-Sections from the Window of Cosmic Ray
Experiments | The talk presented at the IXth Blois Workshop, Pruhonice near Prague,
June 9-15, 2001, Latex2e, 7 figures, this version was sent for publication in
the Physics Letters B; misprints in caption for figures removed, improved
cosmic ray data from current database included | null | null | IHEP 2001-23 | hep-ph astro-ph | null | The importance of cosmic-ray experimental measurements of proton-proton total
cross sections to understand the underlying fundamental dynamics is discussed.
It is shown that early discovered global structure of proton-proton total cross
section [5,17] is completely compatible with the values obtained from
cosmic-ray experiments.
| [
{
"created": "Tue, 14 Aug 2001 14:22:34 GMT",
"version": "v1"
},
{
"created": "Fri, 30 Nov 2001 19:26:20 GMT",
"version": "v2"
},
{
"created": "Fri, 20 Dec 2002 19:06:55 GMT",
"version": "v3"
}
] | 2007-05-23 | [
[
"Arkhipov",
"A. A.",
""
]
] | The importance of cosmic-ray experimental measurements of proton-proton total cross sections to understand the underlying fundamental dynamics is discussed. It is shown that early discovered global structure of proton-proton total cross section [5,17] is completely compatible with the values obtained from cosmic-ray experiments. |
1506.08805 | Mateusz Duch | Mateusz Duch, Bohdan Grzadkowski, Moritz McGarrie | A stable Higgs portal with vector dark matter | 32 pages, 18 figures, v2: references added, minor corrections,
published in JHEP | JHEP 1509 (2015) 162 | 10.1007/JHEP09(2015)162 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We explore an extension of the Standard Model by an additional U (1) gauge
group and a complex scalar Higgs portal. As the scalar is charged under this
gauge factor this simple model supplies a vector dark matter candidate
satisfying the observed relic abundance and limits from direct dark matter
searches. An additional Higgs-like state, that may be heavier or lighter than
the observed Higgs, is present and satisfies LEP and LHC bounds whilst allowing
for absolute stability of the electroweak vacuum in a range of parameter space.
| [
{
"created": "Mon, 29 Jun 2015 19:58:23 GMT",
"version": "v1"
},
{
"created": "Wed, 23 Sep 2015 18:26:26 GMT",
"version": "v2"
}
] | 2015-09-24 | [
[
"Duch",
"Mateusz",
""
],
[
"Grzadkowski",
"Bohdan",
""
],
[
"McGarrie",
"Moritz",
""
]
] | We explore an extension of the Standard Model by an additional U (1) gauge group and a complex scalar Higgs portal. As the scalar is charged under this gauge factor this simple model supplies a vector dark matter candidate satisfying the observed relic abundance and limits from direct dark matter searches. An additional Higgs-like state, that may be heavier or lighter than the observed Higgs, is present and satisfies LEP and LHC bounds whilst allowing for absolute stability of the electroweak vacuum in a range of parameter space. |
0710.1044 | Peihong Gu | Pei-Hong Gu | Unified picture for Dirac neutrinos, dark matter, dark energy and
matter-antimatter asymmetry | 5 pages, 3 figures. Title changed. Abstract, introduction and summary
revised. References added. Model and conclusion unchanged | Phys.Lett.B661:290-294,2008 | 10.1016/j.physletb.2008.02.030 | null | hep-ph | null | We propose a unified scenario to generate the masses of Dirac neutrinos and
cold dark matter at the TeV scale, understand the origin of dark energy and
explain the matter-antimatter asymmetry of the universe. This model can lead to
significant impact on the Higgs searches at LHC.
| [
{
"created": "Thu, 4 Oct 2007 18:30:08 GMT",
"version": "v1"
},
{
"created": "Tue, 16 Oct 2007 13:48:48 GMT",
"version": "v2"
},
{
"created": "Sat, 27 Oct 2007 15:28:31 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Gu",
"Pei-Hong",
""
]
] | We propose a unified scenario to generate the masses of Dirac neutrinos and cold dark matter at the TeV scale, understand the origin of dark energy and explain the matter-antimatter asymmetry of the universe. This model can lead to significant impact on the Higgs searches at LHC. |
2010.08907 | Ahmed Rashed Dr | Stefan Antusch, A. Hammad and Ahmed Rashed | Searching for charged lepton flavor violation at $ep$ colliders | 17 pages, 12 figures; matches version published in JHEP | JHEP 03(2021)230 | 10.1007/JHEP03(2021)230 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the sensitivity of electron-proton ($ep$) colliders for
charged lepton flavor violation (cLFV) in an effective theory approach,
considering a general effective Lagrangian for the conversion of an electron
into a muon or a tau via the effective coupling to a neutral gauge boson or a
neutral scalar field. For the photon, the $Z$ boson and the Higgs particle of
the Standard Model, we present the sensitivities of the LHeC for the
coefficients of the effective operators, calculated from an analysis at the
reconstructed level. As an example model where such flavor changing neutral
current (FCNC) operators are generated at loop level, we consider the extension
of the Standard Model by sterile neutrinos. We show that the LHeC could already
probe the LFV conversion of an electron into a muon beyond the current
experimental bounds, and could reach more than an order of magnitude higher
sensitivity than the present limits for LFV conversion of an electron into a
tau. We discuss that the high sensitivities are possible because the converted
charged lepton is dominantly emitted in the backward direction, enabling an
efficient separation of the signal from the background.
| [
{
"created": "Sun, 18 Oct 2020 02:44:41 GMT",
"version": "v1"
},
{
"created": "Mon, 29 Mar 2021 07:38:44 GMT",
"version": "v2"
},
{
"created": "Sat, 5 Jun 2021 02:00:08 GMT",
"version": "v3"
}
] | 2021-06-08 | [
[
"Antusch",
"Stefan",
""
],
[
"Hammad",
"A.",
""
],
[
"Rashed",
"Ahmed",
""
]
] | We investigate the sensitivity of electron-proton ($ep$) colliders for charged lepton flavor violation (cLFV) in an effective theory approach, considering a general effective Lagrangian for the conversion of an electron into a muon or a tau via the effective coupling to a neutral gauge boson or a neutral scalar field. For the photon, the $Z$ boson and the Higgs particle of the Standard Model, we present the sensitivities of the LHeC for the coefficients of the effective operators, calculated from an analysis at the reconstructed level. As an example model where such flavor changing neutral current (FCNC) operators are generated at loop level, we consider the extension of the Standard Model by sterile neutrinos. We show that the LHeC could already probe the LFV conversion of an electron into a muon beyond the current experimental bounds, and could reach more than an order of magnitude higher sensitivity than the present limits for LFV conversion of an electron into a tau. We discuss that the high sensitivities are possible because the converted charged lepton is dominantly emitted in the backward direction, enabling an efficient separation of the signal from the background. |
hep-ph/9702368 | Andrew Liddle | Ana Achucarro, Julian Borrill and Andrew R Liddle | Semilocal string formation in two dimensions | 9 pages RevTeX file with five figures incorporated (uses RevTeX and
epsf). Also available by WWW at
http://star-www.cpes.susx.ac.uk/people/arl_recent.html where you can also
find a 100 frame MPEG movie (0.5Mb) of one of the simulations. Matches
published version | Phys.Rev. D57 (1998) 3742-3748 | 10.1103/PhysRevD.57.3742 | EHU-FT/9702, DART-HEP-97/02, SUSSEX-AST 97/2-1 | hep-ph | null | We present a toy model for the investigation of the formation of semilocal
strings, where a planar symmetry is employed to reduce the system to two
dimensions. We approximate the symmetry breaking using an extension of the
Vachaspati-Vilenkin algorithm, where we throw down random phases for the scalar
fields and then find the gauge field configuration which minimizes gradient
energy in this fixed scalar background. We show this procedure reproduces the
standard estimate for the formation rate of cosmic strings. For semilocal
strings the configurations generated by this method are ambiguous, and we
numerically evolve the configurations forward in time to identify which regions
form strings. We find a significant rate of formation, depending on the ratio
of couplings $\beta$. For low $\beta$ the formation rate is about one quarter
that of cosmic strings; this falls as $\beta$ is increased and above $\beta =
1$, where the string solution is dynamically unstable, no semilocal strings
form. We show the results are robust by examining different initial conditions
where, as expected in a thermal environment, the initial scalar field need not
be on the vacuum. We discuss implications for the three-dimensional case.
| [
{
"created": "Wed, 19 Feb 1997 08:49:04 GMT",
"version": "v1"
},
{
"created": "Tue, 13 Jan 1998 15:17:35 GMT",
"version": "v2"
}
] | 2009-10-30 | [
[
"Achucarro",
"Ana",
""
],
[
"Borrill",
"Julian",
""
],
[
"Liddle",
"Andrew R",
""
]
] | We present a toy model for the investigation of the formation of semilocal strings, where a planar symmetry is employed to reduce the system to two dimensions. We approximate the symmetry breaking using an extension of the Vachaspati-Vilenkin algorithm, where we throw down random phases for the scalar fields and then find the gauge field configuration which minimizes gradient energy in this fixed scalar background. We show this procedure reproduces the standard estimate for the formation rate of cosmic strings. For semilocal strings the configurations generated by this method are ambiguous, and we numerically evolve the configurations forward in time to identify which regions form strings. We find a significant rate of formation, depending on the ratio of couplings $\beta$. For low $\beta$ the formation rate is about one quarter that of cosmic strings; this falls as $\beta$ is increased and above $\beta = 1$, where the string solution is dynamically unstable, no semilocal strings form. We show the results are robust by examining different initial conditions where, as expected in a thermal environment, the initial scalar field need not be on the vacuum. We discuss implications for the three-dimensional case. |
hep-ph/9308227 | Michel van Eijck | M.A. van Eijck, C.R. Stephens and Ch.G. van Weert | Temperature Dependence of the QCD Coupling | 10 pages, LaTeX (5 postscript figures available),
ITFA-93-11,THU-93/08 | Mod.Phys.Lett.A9:309-320,1994 | 10.1142/S0217732394000320 | null | hep-ph | null | We present a one-loop calculation of a gauge invariant QCD beta function.
Using both momentum and temperature renormalization group equations we
investigate the running coupling in the magnetic sector as a function of
temperature and momentum scale. At fixed momentum scale we find that, in
contrast to $\lambda\phi^4$ or QED, high-temperature QCD is strongly coupled,
even after renormalization group improvement. However, if the momentum scale is
changed simultaneously with temperature in a specified manner, the coupling
decreases. We also point out in what regime dimensional reduction occurs. Both
the cases $N_f$ smaller and larger than $\frac{11}{2} N_c$ are discussed.
| [
{
"created": "Wed, 4 Aug 1993 13:23:05 GMT",
"version": "v1"
}
] | 2016-09-01 | [
[
"van Eijck",
"M. A.",
""
],
[
"Stephens",
"C. R.",
""
],
[
"van Weert",
"Ch. G.",
""
]
] | We present a one-loop calculation of a gauge invariant QCD beta function. Using both momentum and temperature renormalization group equations we investigate the running coupling in the magnetic sector as a function of temperature and momentum scale. At fixed momentum scale we find that, in contrast to $\lambda\phi^4$ or QED, high-temperature QCD is strongly coupled, even after renormalization group improvement. However, if the momentum scale is changed simultaneously with temperature in a specified manner, the coupling decreases. We also point out in what regime dimensional reduction occurs. Both the cases $N_f$ smaller and larger than $\frac{11}{2} N_c$ are discussed. |
1211.4685 | Amin Rezaei Akbarieh | Yasaman Farzan and Amin Rezaei Akbarieh | Natural explanation for 130 GeV photon line within vector boson dark
matter model | 11 pages,4 figures,Discussion of the generalized Chern-Simons term is
added | null | 10.1016/j.physletb.2013.06.004 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a dark matter model for explaining the observed 130 GeV photon
line from the galaxy center. The dark matter candidate is a vector boson of
mass $m_V$ with a dimensionless coupling to the photon and $Z$ boson. The model
predicts a double line photon spectrum at energies equal to $m_V$ and
$m_V(1-m_Z^2/4m_V^2)$ originating from the dark matter annihilation. The same
coupling leads to a mono-photon plus missing energy signal at the LHC. The
entire perturbative parameter space can be probed by the 14 TeV LHC run. The
model has also a good prospect of being probed by direct dark matter searches
as well as the measurement of the rates of $h \to \gamma \gamma$ and $h \to Z
\gamma$ at the LHC.
| [
{
"created": "Tue, 20 Nov 2012 08:33:34 GMT",
"version": "v1"
},
{
"created": "Fri, 7 Dec 2012 09:59:47 GMT",
"version": "v2"
},
{
"created": "Thu, 30 May 2013 16:28:14 GMT",
"version": "v3"
}
] | 2015-06-12 | [
[
"Farzan",
"Yasaman",
""
],
[
"Akbarieh",
"Amin Rezaei",
""
]
] | We present a dark matter model for explaining the observed 130 GeV photon line from the galaxy center. The dark matter candidate is a vector boson of mass $m_V$ with a dimensionless coupling to the photon and $Z$ boson. The model predicts a double line photon spectrum at energies equal to $m_V$ and $m_V(1-m_Z^2/4m_V^2)$ originating from the dark matter annihilation. The same coupling leads to a mono-photon plus missing energy signal at the LHC. The entire perturbative parameter space can be probed by the 14 TeV LHC run. The model has also a good prospect of being probed by direct dark matter searches as well as the measurement of the rates of $h \to \gamma \gamma$ and $h \to Z \gamma$ at the LHC. |
hep-ph/0301040 | Heather E. Logan | Tao Han, Heather E. Logan, Bob McElrath, and Lian-Tao Wang | Phenomenology of the Little Higgs Model | 43 pages, 6 figures; v2: discussion clarified, typos corrected; v3:
version to appear in PRD; v4: typos fixed in Feynman rules | Phys.Rev. D67 (2003) 095004 | 10.1103/PhysRevD.67.095004 | MADPH-02-1317 | hep-ph | null | We study the low energy phenomenology of the little Higgs model. We first
discuss the linearized effective theory of the "littlest Higgs model" and study
the low energy constraints on the model parameters. We identify sources of the
corrections to low energy observables, discuss model-dependent arbitrariness,
and outline some possible directions of extensions of the model in order to
evade the precision electroweak constraints. We then explore the characteristic
signatures to test the model in the current and future collider experiments. We
find that the LHC has great potential to discover the new SU(2) gauge bosons
and the possible new U(1) gauge boson to the multi-TeV mass scale. Other states
such as the colored vector-like quark T and doubly-charged Higgs boson Phi^{++}
may also provide interesting signals. At a linear collider, precision
measurements on the triple gauge boson couplings could be sensitive to the new
physics scale of a few TeV. We provide a comprehensive list of the linearized
interactions and vertices for the littlest Higgs model in the appendices.
| [
{
"created": "Wed, 8 Jan 2003 18:18:47 GMT",
"version": "v1"
},
{
"created": "Sun, 2 Feb 2003 17:38:53 GMT",
"version": "v2"
},
{
"created": "Wed, 26 Mar 2003 17:17:05 GMT",
"version": "v3"
},
{
"created": "Fri, 2 Apr 2004 19:20:46 GMT",
"version": "v4"
}
] | 2009-11-10 | [
[
"Han",
"Tao",
""
],
[
"Logan",
"Heather E.",
""
],
[
"McElrath",
"Bob",
""
],
[
"Wang",
"Lian-Tao",
""
]
] | We study the low energy phenomenology of the little Higgs model. We first discuss the linearized effective theory of the "littlest Higgs model" and study the low energy constraints on the model parameters. We identify sources of the corrections to low energy observables, discuss model-dependent arbitrariness, and outline some possible directions of extensions of the model in order to evade the precision electroweak constraints. We then explore the characteristic signatures to test the model in the current and future collider experiments. We find that the LHC has great potential to discover the new SU(2) gauge bosons and the possible new U(1) gauge boson to the multi-TeV mass scale. Other states such as the colored vector-like quark T and doubly-charged Higgs boson Phi^{++} may also provide interesting signals. At a linear collider, precision measurements on the triple gauge boson couplings could be sensitive to the new physics scale of a few TeV. We provide a comprehensive list of the linearized interactions and vertices for the littlest Higgs model in the appendices. |
hep-ph/9510270 | null | Stephan Narison (Univ. Montpellier II-France) | Heavy flavours from QCD spectral sum rules | 10 pages on Latex file. published version: minor modifications
compared with the previous version. Contribution to the session on
non-perturbative methods, EPS conference HEP (July 1995) Brussells | null | null | Montpellier preprint 95/43 | hep-ph | null | We present a summary update of the QCD spectral sum rule (QSSR) results for
the running and {\it perturbative pole} quark masses, the $f_D$ and $f_B$
leptonic decay constants, the heavy-to-light and heavy-to-heavy exclusive
transition-form factors. Analytic expressions of these latter quantities are
presented, which give a deeper understanding of their $q^2$- and infinite
mass-behaviours. A short comparison of the QSSR results with alternative
approaches is done.
| [
{
"created": "Wed, 11 Oct 1995 10:17:08 GMT",
"version": "v1"
},
{
"created": "Tue, 21 Nov 1995 13:23:27 GMT",
"version": "v2"
}
] | 2008-02-03 | [
[
"Narison",
"Stephan",
"",
"Univ. Montpellier II-France"
]
] | We present a summary update of the QCD spectral sum rule (QSSR) results for the running and {\it perturbative pole} quark masses, the $f_D$ and $f_B$ leptonic decay constants, the heavy-to-light and heavy-to-heavy exclusive transition-form factors. Analytic expressions of these latter quantities are presented, which give a deeper understanding of their $q^2$- and infinite mass-behaviours. A short comparison of the QSSR results with alternative approaches is done. |
1903.07506 | Rabindra N. Mohapatra | Yukihiro Mimura, Rabindra N. Mohapatra and Matt Severson | A Grand Unified Parity Solution to Strong CP Problem | 5 pages, 1 figure | Phys. Rev. D 99, 115025 (2019) | 10.1103/PhysRevD.99.115025 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A beyond the standard model theory that respects parity symmetry at short
distances is known to provide a solution to the strong CP problem without the
need for an axion, while keeping the CKM phase unconstrained. In this paper we
present a supersymmetric SO(10) grand unified embedding of this idea with
Yukawa couplings generated by {\bf 10}, ${\bf \overline{126}}$ and {\bf 120}
Higgs fields. This model is known to provide a unified description of masses
and mixings of quarks and leptons. When CP symmetry is imposed on this model,
the discrete gauge subgroup C of SO(10) combines with it to generate an
effective parity symmetry, leading to hermitian quark mass matrices. Imposing
an additional discrete symmetry, $G$, we show that there are no other tree
level sources of $\theta$ in the model; $G$ also guarantees that the one- and
two-loop contributions to $\theta$ vanish. We then show that the leading
three-loop effects and the effect of higher-dimensional operators invariant
under $G$ give rise to $\theta$ near the current experimental bound, making the
model testable in the current searches for neutron electric dipole moment.
| [
{
"created": "Mon, 18 Mar 2019 15:26:14 GMT",
"version": "v1"
}
] | 2019-06-26 | [
[
"Mimura",
"Yukihiro",
""
],
[
"Mohapatra",
"Rabindra N.",
""
],
[
"Severson",
"Matt",
""
]
] | A beyond the standard model theory that respects parity symmetry at short distances is known to provide a solution to the strong CP problem without the need for an axion, while keeping the CKM phase unconstrained. In this paper we present a supersymmetric SO(10) grand unified embedding of this idea with Yukawa couplings generated by {\bf 10}, ${\bf \overline{126}}$ and {\bf 120} Higgs fields. This model is known to provide a unified description of masses and mixings of quarks and leptons. When CP symmetry is imposed on this model, the discrete gauge subgroup C of SO(10) combines with it to generate an effective parity symmetry, leading to hermitian quark mass matrices. Imposing an additional discrete symmetry, $G$, we show that there are no other tree level sources of $\theta$ in the model; $G$ also guarantees that the one- and two-loop contributions to $\theta$ vanish. We then show that the leading three-loop effects and the effect of higher-dimensional operators invariant under $G$ give rise to $\theta$ near the current experimental bound, making the model testable in the current searches for neutron electric dipole moment. |
2211.14465 | Di-Lun Yang | Naoki Yamamoto, Di-Lun Yang | Effective Chiral Magnetic Effect from Neutrino Radiation | 6 pages, 1 figure, journal version | Phys. Rev. Lett. 131, 012701 (2023) | 10.1103/PhysRevLett.131.012701 | null | hep-ph astro-ph.HE nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We develop an approach to chiral kinetic theories for electrons close to
equilibrium and neutrinos away from equilibrium based on a systematic power
counting scheme for different timescales of electromagnetic and weak
interactions. Under this framework, we derive electric and energy currents
along magnetic fields induced by neutrino radiation in general nonequilibrium
states. This may be regarded as an effective chiral magnetic effect (CME),
which is present without a chiral chemical potential, unlike the conventional
CME. We also consider the so-called gain region of core-collapse supernovae as
an example and find that the effective CME enhanced by persistent neutrino
emission in time is sufficiently large to lead to the inverse cascade of
magnetic and fluid kinetic energies and observed magnitudes of pulsar kicks.
Our framework may also be applicable to other dense-matter systems involving
nonequilibrium neutrinos.
| [
{
"created": "Sat, 26 Nov 2022 03:12:38 GMT",
"version": "v1"
},
{
"created": "Sat, 8 Jul 2023 05:54:47 GMT",
"version": "v2"
}
] | 2023-07-11 | [
[
"Yamamoto",
"Naoki",
""
],
[
"Yang",
"Di-Lun",
""
]
] | We develop an approach to chiral kinetic theories for electrons close to equilibrium and neutrinos away from equilibrium based on a systematic power counting scheme for different timescales of electromagnetic and weak interactions. Under this framework, we derive electric and energy currents along magnetic fields induced by neutrino radiation in general nonequilibrium states. This may be regarded as an effective chiral magnetic effect (CME), which is present without a chiral chemical potential, unlike the conventional CME. We also consider the so-called gain region of core-collapse supernovae as an example and find that the effective CME enhanced by persistent neutrino emission in time is sufficiently large to lead to the inverse cascade of magnetic and fluid kinetic energies and observed magnitudes of pulsar kicks. Our framework may also be applicable to other dense-matter systems involving nonequilibrium neutrinos. |
hep-ph/9412215 | Yoshimasa Kurihara | Y. Kurihara, D. Perret-Gallix, Y. Shimizu | $e^+ e^- \to e^- {\bar \nu_e} u {\bar d}$ from LEP to linear collider
energies | 18 pages, uses epsfig.sty, 10 postscript figures. revised for minor
change of the text at Dec 6 1994 | Phys.Lett. B349 (1995) 367-374 | 10.1016/0370-2693(95)00298-Y | KEK preprint 94-150, KEK CP-021, LAPP-EXP-94.23 | hep-ph | null | The complete tree level cross section for the process $e^+e^- \to e^-
\bar\nu_e u \bar{d}$ is computed using the GRACE system, a program package for
automatic amplitude calculation. Special attention is brought to the gauge
violation problem induced by the finite width of the $W$-boson. The {\it
preserved gauge scheme} is introduced and an event generator which includes
double-resonant, single-resonant and non-resonant diagrams with no need for a
cut on the electron polar angle is presented. Since no cut needs to be applied
to the electron, the generator can be used to estimate background for searches
involving jets and missing energy. A monojet event rate estimation based on
this process at LEP-I energy is discussed.
| [
{
"created": "Fri, 2 Dec 1994 09:25:02 GMT",
"version": "v1"
},
{
"created": "Tue, 6 Dec 1994 02:48:45 GMT",
"version": "v2"
}
] | 2009-10-28 | [
[
"Kurihara",
"Y.",
""
],
[
"Perret-Gallix",
"D.",
""
],
[
"Shimizu",
"Y.",
""
]
] | The complete tree level cross section for the process $e^+e^- \to e^- \bar\nu_e u \bar{d}$ is computed using the GRACE system, a program package for automatic amplitude calculation. Special attention is brought to the gauge violation problem induced by the finite width of the $W$-boson. The {\it preserved gauge scheme} is introduced and an event generator which includes double-resonant, single-resonant and non-resonant diagrams with no need for a cut on the electron polar angle is presented. Since no cut needs to be applied to the electron, the generator can be used to estimate background for searches involving jets and missing energy. A monojet event rate estimation based on this process at LEP-I energy is discussed. |
1108.2525 | Di-Lun Yang | Di-Lun Yang and Berndt M\"uller | $J/\psi$ Production by Magnetic Excitation of $\eta_c$ | 7 pages, minor modification, references added | J. Phys. G: Nucl. Part. Phys. 39 (2012) 015007 | 10.1088/0954-3899/39/1/015007 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We compute the probability of $J/\psi$ production from the interaction
between $\eta_c$ and the strong magnetic field generated in relativistic heavy
ion collisions. The computation is first carried out in the heavy quark
effective model, in which the M1 radiative transition is considered. Then we
investigate the transition in the framework of non-relativistic heavy hadron
chiral perturbation theory and show that the polarization of $J/\psi$ produced
by this process is parallel to the direction of magnetic field and thus
perpendicular to the reaction plane. The transition probability obtained in
both approaches is of order $2\times 10^{-4}$.
| [
{
"created": "Thu, 11 Aug 2011 21:22:38 GMT",
"version": "v1"
},
{
"created": "Mon, 22 Aug 2011 16:29:47 GMT",
"version": "v2"
},
{
"created": "Thu, 8 Sep 2011 04:05:18 GMT",
"version": "v3"
},
{
"created": "Mon, 3 Oct 2011 15:33:15 GMT",
"version": "v4"
},
{
"cre... | 2011-12-14 | [
[
"Yang",
"Di-Lun",
""
],
[
"Müller",
"Berndt",
""
]
] | We compute the probability of $J/\psi$ production from the interaction between $\eta_c$ and the strong magnetic field generated in relativistic heavy ion collisions. The computation is first carried out in the heavy quark effective model, in which the M1 radiative transition is considered. Then we investigate the transition in the framework of non-relativistic heavy hadron chiral perturbation theory and show that the polarization of $J/\psi$ produced by this process is parallel to the direction of magnetic field and thus perpendicular to the reaction plane. The transition probability obtained in both approaches is of order $2\times 10^{-4}$. |
1201.2608 | Stefan Lanz | Johan Bijnens, Karol Kampf, Stefan Lanz | Leading logarithms in the anomalous sector of two-flavour QCD | 27 pages, 8 figures, 7 tables, published version | Nucl.Phys.B860:245-266,2012 | 10.1016/j.nuclphysb.2012.02.014 | LU TP 12-02 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We add the Wess-Zumino-Witten term to the N=3 massive nonlinear sigma model
and study the leading logarithms in the anomalous sector. We obtain the leading
logarithms to six loops for \pi^0 --> \gamma^*\gamma^* and to five loops for
\gamma^*\pi\pi\pi. In addition we extend the earlier work on the mass and decay
constant to six loops and the vector form factor to five loops. We present
numerical result for the anomalous processes and the vector form factor. In all
cases the series are found to converge rapidly.
| [
{
"created": "Thu, 12 Jan 2012 16:17:30 GMT",
"version": "v1"
},
{
"created": "Tue, 20 Mar 2012 07:49:52 GMT",
"version": "v2"
}
] | 2012-03-21 | [
[
"Bijnens",
"Johan",
""
],
[
"Kampf",
"Karol",
""
],
[
"Lanz",
"Stefan",
""
]
] | We add the Wess-Zumino-Witten term to the N=3 massive nonlinear sigma model and study the leading logarithms in the anomalous sector. We obtain the leading logarithms to six loops for \pi^0 --> \gamma^*\gamma^* and to five loops for \gamma^*\pi\pi\pi. In addition we extend the earlier work on the mass and decay constant to six loops and the vector form factor to five loops. We present numerical result for the anomalous processes and the vector form factor. In all cases the series are found to converge rapidly. |
2403.01729 | Hugues Beauchesne | Hugues Beauchesne and Cheng-Wei Chiang | Dark matter semi-annihilation for inert scalar multiplets | 26 pages, 4 figures, references added, treatment of SE improved,
matches published version | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Dark matter semi-annihilation is a process through which two dark matter
candidates annihilate to a single dark matter particle and a non-dark matter
particle. Such processes are common when the symmetry stabilizing the dark
matter differs from $\mathbb{Z}_2$ and can lead to qualitatively different
phenomenology. In this work, we study the viability of semi-annihilation models
including one or two inert multiplets. For one multiplet, we show that there
does not exist any viable model in which semi-annihilation is efficient. For
two multiplets, semi-annihilation can be efficient, but the number of viable
and technically natural models is limited. We then perform a detailed study of
the most promising model, showing that the correct relic abundance can be
obtained for a wide range of masses.
| [
{
"created": "Mon, 4 Mar 2024 04:43:33 GMT",
"version": "v1"
},
{
"created": "Mon, 15 Apr 2024 11:14:05 GMT",
"version": "v2"
},
{
"created": "Thu, 27 Jun 2024 07:34:13 GMT",
"version": "v3"
}
] | 2024-06-28 | [
[
"Beauchesne",
"Hugues",
""
],
[
"Chiang",
"Cheng-Wei",
""
]
] | Dark matter semi-annihilation is a process through which two dark matter candidates annihilate to a single dark matter particle and a non-dark matter particle. Such processes are common when the symmetry stabilizing the dark matter differs from $\mathbb{Z}_2$ and can lead to qualitatively different phenomenology. In this work, we study the viability of semi-annihilation models including one or two inert multiplets. For one multiplet, we show that there does not exist any viable model in which semi-annihilation is efficient. For two multiplets, semi-annihilation can be efficient, but the number of viable and technically natural models is limited. We then perform a detailed study of the most promising model, showing that the correct relic abundance can be obtained for a wide range of masses. |
2110.13792 | Ming-Zhu Liu | Xi-Zhe Ling, Ming-Zhu Liu, and Li-Sheng Geng | Masses and strong decays of open charm hexaquark states
$\Sigma_{c}^{(\ast)}{\Sigma}_{c}^{(\ast)}$ | null | null | 10.1140/epjc/s10052-021-09867-2 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | Inspired by the recent discovery of the doubly charmed tetraquark state
$T_{cc}^{+}$ by the LHCb Collaboration, we perform a systematic study of masses
and strong decays of open charm hexaquark states
${\Sigma}_{c}^{(\ast)}\Sigma_{c}^{(\ast)}$. Taking into account heavy quark
spin symmetry breaking, we predict several bound states of isospin $I=0$,
$I=1$, and $I=2$ in the one boson exchange model. Moreover, we adopt the
effective Lagrangian approach to estimate the decay widths of
${\Sigma}_{c}^{(\ast)}\Sigma_{c}^{(\ast)} \to \Lambda_{c}\Lambda_{c}$ and their
relevant ratios via the triangle diagram mechanism, which range from a few MeV
to a few tens of MeV. We strongly recommend future experimental searches for
the ${\Sigma}_{c}^{(\ast)}\Sigma_{c}^{(\ast)}$ hexaquark states in the
$\Lambda_c\Lambda_c$ invariant mass distributions.
| [
{
"created": "Tue, 26 Oct 2021 15:45:19 GMT",
"version": "v1"
}
] | 2022-01-05 | [
[
"Ling",
"Xi-Zhe",
""
],
[
"Liu",
"Ming-Zhu",
""
],
[
"Geng",
"Li-Sheng",
""
]
] | Inspired by the recent discovery of the doubly charmed tetraquark state $T_{cc}^{+}$ by the LHCb Collaboration, we perform a systematic study of masses and strong decays of open charm hexaquark states ${\Sigma}_{c}^{(\ast)}\Sigma_{c}^{(\ast)}$. Taking into account heavy quark spin symmetry breaking, we predict several bound states of isospin $I=0$, $I=1$, and $I=2$ in the one boson exchange model. Moreover, we adopt the effective Lagrangian approach to estimate the decay widths of ${\Sigma}_{c}^{(\ast)}\Sigma_{c}^{(\ast)} \to \Lambda_{c}\Lambda_{c}$ and their relevant ratios via the triangle diagram mechanism, which range from a few MeV to a few tens of MeV. We strongly recommend future experimental searches for the ${\Sigma}_{c}^{(\ast)}\Sigma_{c}^{(\ast)}$ hexaquark states in the $\Lambda_c\Lambda_c$ invariant mass distributions. |
hep-ph/9409256 | Kiselev | V.V.Kiselev | Lambda-bar from QCD sum rules for heavy quarkonium | Preprint IHEP 94-89, 4 LATEX pages | JETP Lett. 60 (1994) 509-512; Pisma Zh.Eksp.Teor.Fiz. 60 (1994)
498-500 | null | null | hep-ph | null | Using a specific scheme of the QCD sum rules for heavy quarkonium in the
leading approximation over the inverse heavy quark mass, one gets the estimate
of the difference between the masses of the heavy meson and heavy quark $\bar
\Lambda = 0.59\pm 0.02$ GeV.
| [
{
"created": "Thu, 8 Sep 1994 14:27:36 GMT",
"version": "v1"
},
{
"created": "Fri, 9 Sep 1994 15:09:53 GMT",
"version": "v2"
}
] | 2008-02-03 | [
[
"Kiselev",
"V. V.",
""
]
] | Using a specific scheme of the QCD sum rules for heavy quarkonium in the leading approximation over the inverse heavy quark mass, one gets the estimate of the difference between the masses of the heavy meson and heavy quark $\bar \Lambda = 0.59\pm 0.02$ GeV. |
1312.2747 | Philippe Brax | Philippe Brax and Amol Upadhye | Chameleon Fragmentation | 27 pages, 7 figures | null | 10.1088/1475-7516/2014/02/018 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A scalar field dark energy candidate could couple to ordinary matter and
photons, enabling its detection in laboratory experiments. Here we study the
quantum properties of the chameleon field, one such dark energy candidate, in
an "afterglow" experiment designed to produce, trap, and detect chameleon
particles. In particular, we investigate the possible fragmentation of a beam
of chameleon particles into multiple particle states due to the highly
non-linear interaction terms in the chameleon Lagrangian. Fragmentation could
weaken the constraints of an afterglow experiment by reducing the energy of the
regenerated photons, but this energy reduction also provides a unique signature
which could be detected by a properly-designed experiment. We show that
constraints from the CHASE experiment are essentially unaffected by
fragmentation for $\phi^4$ and $1/\phi$ potentials, but are weakened for
steeper potentials, and we discuss possible future afterglow experiments.
| [
{
"created": "Tue, 10 Dec 2013 10:25:59 GMT",
"version": "v1"
}
] | 2015-06-18 | [
[
"Brax",
"Philippe",
""
],
[
"Upadhye",
"Amol",
""
]
] | A scalar field dark energy candidate could couple to ordinary matter and photons, enabling its detection in laboratory experiments. Here we study the quantum properties of the chameleon field, one such dark energy candidate, in an "afterglow" experiment designed to produce, trap, and detect chameleon particles. In particular, we investigate the possible fragmentation of a beam of chameleon particles into multiple particle states due to the highly non-linear interaction terms in the chameleon Lagrangian. Fragmentation could weaken the constraints of an afterglow experiment by reducing the energy of the regenerated photons, but this energy reduction also provides a unique signature which could be detected by a properly-designed experiment. We show that constraints from the CHASE experiment are essentially unaffected by fragmentation for $\phi^4$ and $1/\phi$ potentials, but are weakened for steeper potentials, and we discuss possible future afterglow experiments. |
hep-ph/9605222 | Masahiro Yamaguchi | Stefano Borgani, Antonio Masiero, Masahiro Yamaguchi | Light Gravitinos as Mixed Dark Matter | 18 pages, LaTeX, no figure | Phys.Lett. B386 (1996) 189-197 | 10.1016/0370-2693(96)00956-2 | TUM-HEP-242/96, SFB-375/95 | hep-ph astro-ph | null | In theories with a gauge-mediated mechanism of supersymmetry breaking the
gravitino is likely to be the lightest superparticle and, hence, a candidate
for dark matter. We show that the decay of the next-to-lightest superparticle
into a gravitino can yield a non-thermal population of gravitinos which behave
as a hot dark matter component. Together with the warm component, which is
provided by the population of gravitinos of thermal origin, they can give rise
to viable schemes of mixed dark matter. This realization has some specific and
testable features both in particle physics and astrophysics. We outline under
which conditions the mechanism remains viable even when R parity is broken.
| [
{
"created": "Fri, 3 May 1996 15:29:21 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Borgani",
"Stefano",
""
],
[
"Masiero",
"Antonio",
""
],
[
"Yamaguchi",
"Masahiro",
""
]
] | In theories with a gauge-mediated mechanism of supersymmetry breaking the gravitino is likely to be the lightest superparticle and, hence, a candidate for dark matter. We show that the decay of the next-to-lightest superparticle into a gravitino can yield a non-thermal population of gravitinos which behave as a hot dark matter component. Together with the warm component, which is provided by the population of gravitinos of thermal origin, they can give rise to viable schemes of mixed dark matter. This realization has some specific and testable features both in particle physics and astrophysics. We outline under which conditions the mechanism remains viable even when R parity is broken. |
hep-ph/9711365 | U. Meissner | Ulf-G. Mei{\ss}ner | Chiral nucleon dynamics | 46 pp, LaTeX, uses epsf, lectures delivered at the 12th Annual
Hampton University Graduate Studies (HUGS) at CEBAF, Newport News, June 2-20,
1997, to appear in the proceedings | null | null | KFA-IKP(TH)-97-20 | hep-ph nucl-th | null | These lectures give an introduction to baryon chiral perturbation theory. I
show in detail how to construct the chiral effective pion-nucleon Lagrangian in
the one loop approximation. Particular emphasis is put on the physics related
to electromagnetic probes, as manifest in pion photo- and electroproduction,
Compton scattering off nucleons and the electroweak form factors of the
nucleon. Other topics discussed in some detail are the meaning of low-energy
theorems, pion-nucleon scattering, the reaction $\pi N \to \pi \pi N$ and
isospin violation in the pion-nucleon system. The chiral predictions are
confronted with the existing data. Some remaining problems and new developments
are outlined.
| [
{
"created": "Tue, 18 Nov 1997 12:46:26 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Meißner",
"Ulf-G.",
""
]
] | These lectures give an introduction to baryon chiral perturbation theory. I show in detail how to construct the chiral effective pion-nucleon Lagrangian in the one loop approximation. Particular emphasis is put on the physics related to electromagnetic probes, as manifest in pion photo- and electroproduction, Compton scattering off nucleons and the electroweak form factors of the nucleon. Other topics discussed in some detail are the meaning of low-energy theorems, pion-nucleon scattering, the reaction $\pi N \to \pi \pi N$ and isospin violation in the pion-nucleon system. The chiral predictions are confronted with the existing data. Some remaining problems and new developments are outlined. |
1111.5830 | Piero Nicolini | Jonas Mureika, Piero Nicolini, Euro Spallucci | Could any black holes be produced at the LHC? | v1: 10 pages, 1 figure; v2: 11 pages, 1 figure, additional
references, minor modifications; v3: new title, expanded discussion with
updated production estimates, additional references, 4 figures, 19 pages,
version accepted for publication on Physical Review D | Phys. Rev. D 85, 106007 (2012) | 10.1103/PhysRevD.85.106007 | null | hep-ph gr-qc hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We introduce analytical quantum gravity modifications of the production cross
section for terascale black holes by employing an effective ultraviolet cut off
$l$. We find the new cross sections approach the usual "black disk" form at
high energy, while they differ significantly near the fundamental scale from
the standard increase with respect to $s$. We show that the heretofore
discontinuous step function used to represent the cross section threshold can
realistically be modeled by two functions representing the incoming and final
parton states in a high energy collision. The growth of the cross section with
collision energy is thus a unique signature of $l$ and number of spatial
dimensions $d$. Contrary to the classical black disk result, our cross section
is able to explain why black holes might not be observable in LHC experiments
while they could be still at the reach of ultra-high energy cosmic ray events.
| [
{
"created": "Thu, 24 Nov 2011 18:43:30 GMT",
"version": "v1"
},
{
"created": "Mon, 12 Dec 2011 23:52:51 GMT",
"version": "v2"
},
{
"created": "Mon, 16 Apr 2012 17:00:13 GMT",
"version": "v3"
}
] | 2012-05-21 | [
[
"Mureika",
"Jonas",
""
],
[
"Nicolini",
"Piero",
""
],
[
"Spallucci",
"Euro",
""
]
] | We introduce analytical quantum gravity modifications of the production cross section for terascale black holes by employing an effective ultraviolet cut off $l$. We find the new cross sections approach the usual "black disk" form at high energy, while they differ significantly near the fundamental scale from the standard increase with respect to $s$. We show that the heretofore discontinuous step function used to represent the cross section threshold can realistically be modeled by two functions representing the incoming and final parton states in a high energy collision. The growth of the cross section with collision energy is thus a unique signature of $l$ and number of spatial dimensions $d$. Contrary to the classical black disk result, our cross section is able to explain why black holes might not be observable in LHC experiments while they could be still at the reach of ultra-high energy cosmic ray events. |
1909.02484 | Anton Ilderton | Anton Ilderton | Exact results for scattering on ultra-short plane wave backgrounds | 9 pages, 4 pdf figures | Phys. Rev. D 100, 125018 (2019) | 10.1103/PhysRevD.100.125018 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We give exact results for the emission spectra of both nonlinear
Breit-Wheeler pair production and nonlinear Compton scattering in
ultra-intense, ultra-short duration plane wave backgrounds, modelled as
delta-function pulses. This includes closed form expressions for total
scattering probabilities. We show explicitly that these probabilities do not
exhibit the power-law scaling with intensity associated with the conjectured
breakdown of (Furry picture) perturbation theory, instead scaling
logarithmically in the high-intensity limit.
| [
{
"created": "Thu, 5 Sep 2019 15:36:59 GMT",
"version": "v1"
}
] | 2019-12-25 | [
[
"Ilderton",
"Anton",
""
]
] | We give exact results for the emission spectra of both nonlinear Breit-Wheeler pair production and nonlinear Compton scattering in ultra-intense, ultra-short duration plane wave backgrounds, modelled as delta-function pulses. This includes closed form expressions for total scattering probabilities. We show explicitly that these probabilities do not exhibit the power-law scaling with intensity associated with the conjectured breakdown of (Furry picture) perturbation theory, instead scaling logarithmically in the high-intensity limit. |
hep-ph/0408177 | Pedro Fernando Simoes Costa | Pedro Costa, M. C. Ruivo, C. A. de Sousa and Yu. L. Kalinovsky | Effective restoration of the U_A(1) symmetry with temperature and
density | 5 pages, 2 figures; PRD version | Phys.Rev. D70 (2004) 116013 | 10.1103/PhysRevD.70.116013 | null | hep-ph | null | We investigate the full U(3)$\otimes$U(3) chiral symmetry restoration, at
finite temperature and density, on the basis of a quark model which
incorporates the most relevant properties of QCD in this context: explicit and
spontaneous breaking of chiral symmetry and axial U$_A$(1) symmetry breaking. A
specific lattice-inspired behavior of the topological susceptibility, combined
with the convergence of chiral partners, signals the onset of an effective
chiral symmetry restoration. The results suggest that the axial part of the
symmetry is restored before the possible restoration of the full
U(3)$\otimes$U(3) chiral symmetry can occur. This conclusion is valid in the
context of both finite temperature and density.
| [
{
"created": "Mon, 16 Aug 2004 16:43:29 GMT",
"version": "v1"
},
{
"created": "Thu, 30 Dec 2004 16:35:55 GMT",
"version": "v2"
}
] | 2016-09-06 | [
[
"Costa",
"Pedro",
""
],
[
"Ruivo",
"M. C.",
""
],
[
"de Sousa",
"C. A.",
""
],
[
"Kalinovsky",
"Yu. L.",
""
]
] | We investigate the full U(3)$\otimes$U(3) chiral symmetry restoration, at finite temperature and density, on the basis of a quark model which incorporates the most relevant properties of QCD in this context: explicit and spontaneous breaking of chiral symmetry and axial U$_A$(1) symmetry breaking. A specific lattice-inspired behavior of the topological susceptibility, combined with the convergence of chiral partners, signals the onset of an effective chiral symmetry restoration. The results suggest that the axial part of the symmetry is restored before the possible restoration of the full U(3)$\otimes$U(3) chiral symmetry can occur. This conclusion is valid in the context of both finite temperature and density. |
hep-ph/0511052 | Stanislaw Mrowczynski | Stanislaw Mrowczynski | Instabilities driven equilibration of the quark-gluon plasma | review, 21 pages, new section on various approaches to QGP
equilibration | Acta Phys.Polon. B37 (2006) 427-454 | null | null | hep-ph nucl-ex nucl-th | null | Due to anisotropic momentum distributions the parton system produced at the
early stage of relativistic heavy-ion collisions is unstable with respect to
the magnetic plasma modes. The instabilities isotropize the system and thus
speed up the process of its equilibration. The whole scenario of the
instabilities driven isotropization is reviewed.
| [
{
"created": "Fri, 4 Nov 2005 18:50:21 GMT",
"version": "v1"
},
{
"created": "Mon, 28 Nov 2005 17:54:13 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Mrowczynski",
"Stanislaw",
""
]
] | Due to anisotropic momentum distributions the parton system produced at the early stage of relativistic heavy-ion collisions is unstable with respect to the magnetic plasma modes. The instabilities isotropize the system and thus speed up the process of its equilibration. The whole scenario of the instabilities driven isotropization is reviewed. |
1507.01584 | Julian Heeck | Julian Heeck, Sudhanwa Patra | Minimal Left-Right Symmetric Dark Matter | 6 pages, 4 figures; minor improvements; to appear in PRL | Phys. Rev. Lett. 115, 121804 (2015) | 10.1103/PhysRevLett.115.121804 | ULB-TH/15-10 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We show that left-right symmetric models can easily accommodate stable
TeV-scale dark matter particles without the need for an ad-hoc stabilizing
symmetry. The stability of a newly introduced multiplet arises either
accidentally as in the Minimal Dark Matter framework or comes courtesy of the
remaining unbroken $\mathbb{Z}_2$ subgroup of $B-L$. Only one new parameter is
introduced: the mass of the new multiplet. As minimal examples we study
left-right fermion triplets and quintuplets and show that they can form viable
two-component dark matter. This approach is in particular valid for
$SU(2)\times SU(2)\times U(1)$ models that explain the recent diboson excess at
ATLAS in terms of a new charged gauge boson of mass 2 TeV.
| [
{
"created": "Mon, 6 Jul 2015 19:59:28 GMT",
"version": "v1"
},
{
"created": "Tue, 14 Jul 2015 12:08:45 GMT",
"version": "v2"
},
{
"created": "Thu, 3 Sep 2015 08:31:01 GMT",
"version": "v3"
}
] | 2015-09-21 | [
[
"Heeck",
"Julian",
""
],
[
"Patra",
"Sudhanwa",
""
]
] | We show that left-right symmetric models can easily accommodate stable TeV-scale dark matter particles without the need for an ad-hoc stabilizing symmetry. The stability of a newly introduced multiplet arises either accidentally as in the Minimal Dark Matter framework or comes courtesy of the remaining unbroken $\mathbb{Z}_2$ subgroup of $B-L$. Only one new parameter is introduced: the mass of the new multiplet. As minimal examples we study left-right fermion triplets and quintuplets and show that they can form viable two-component dark matter. This approach is in particular valid for $SU(2)\times SU(2)\times U(1)$ models that explain the recent diboson excess at ATLAS in terms of a new charged gauge boson of mass 2 TeV. |
2304.02988 | Ruben Concei\c{c}\~ao | A. Bakalov\'a, R. Concei\c{c}\~ao, L. Gibilisco, V. Novotn\'y, M.
Pimenta, B. Tom\'e, J. V\'icha | Azimuthal fluctuations and number of muons at the ground in
muon-depleted proton air showers at PeV energies | null | null | null | null | hep-ph astro-ph.HE hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Muon counting is an effective strategy for discriminating between gamma and
hadron-initiated air showers. However, their detection, which requires shielded
detectors, is highly costly and almost impossible to implement in large ${\rm
km^2}$ environmentally sensitive areas. This work shows that the gamma/hadron
discriminators, based on the new $LCm$ variable and the number of muons, have
equivalent proton rejection levels at the PeV energies. It is, therefore,
possible to build, at an affordable cost, a large, high-performant, wide
field-of-view gamma-ray observatory.
| [
{
"created": "Thu, 6 Apr 2023 10:49:04 GMT",
"version": "v1"
}
] | 2023-04-07 | [
[
"Bakalová",
"A.",
""
],
[
"Conceição",
"R.",
""
],
[
"Gibilisco",
"L.",
""
],
[
"Novotný",
"V.",
""
],
[
"Pimenta",
"M.",
""
],
[
"Tomé",
"B.",
""
],
[
"Vícha",
"J.",
""
]
] | Muon counting is an effective strategy for discriminating between gamma and hadron-initiated air showers. However, their detection, which requires shielded detectors, is highly costly and almost impossible to implement in large ${\rm km^2}$ environmentally sensitive areas. This work shows that the gamma/hadron discriminators, based on the new $LCm$ variable and the number of muons, have equivalent proton rejection levels at the PeV energies. It is, therefore, possible to build, at an affordable cost, a large, high-performant, wide field-of-view gamma-ray observatory. |
1009.1537 | Steven Weinberg | Steven Weinberg | Pions in Large-$N$ Quantum Chromodynamics | Version to be published in Phys. Rev. Letters. Two figures added,
text and abstract revised and shortened. Clearer statement of aims of work. 9
pages | Phys.Rev.Lett.105:261601,2010 | 10.1103/PhysRevLett.105.261601 | UTTG-10-10 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | An effective field theory of quarks, gluons, and pions, with the number $N$
of colors treated as large, is proposed as a basis for calculations of hadronic
phenomena at moderate energies. The qualitative consequences of the large $N$
limit are similar though not identical to those in pure quantum chromodynamics,
but because constituent quark masses appear in the effective Lagrangian, the `t
Hooft coupling in the effective theory need not be strong at moderate energies.
To leading order in $1/N$ the effective theory is renormalizable, with only a
finite number of terms in the Lagrangian.
| [
{
"created": "Wed, 8 Sep 2010 14:10:46 GMT",
"version": "v1"
},
{
"created": "Tue, 14 Dec 2010 17:31:35 GMT",
"version": "v2"
}
] | 2010-12-28 | [
[
"Weinberg",
"Steven",
""
]
] | An effective field theory of quarks, gluons, and pions, with the number $N$ of colors treated as large, is proposed as a basis for calculations of hadronic phenomena at moderate energies. The qualitative consequences of the large $N$ limit are similar though not identical to those in pure quantum chromodynamics, but because constituent quark masses appear in the effective Lagrangian, the `t Hooft coupling in the effective theory need not be strong at moderate energies. To leading order in $1/N$ the effective theory is renormalizable, with only a finite number of terms in the Lagrangian. |
hep-ph/9705392 | null | M. Maris, S. T. Petcov | A Study of the Day - Night Effect for the Super-Kamiokande Detector: II.
Electron Spectrum Deformations and Day - Night Asymmetries | LaTeX, 18 pages, 3 Tables, 16 Figures in 7 postscript files | Phys. Rev. D 56, 7444 (1997) | 10.1103/PhysRevD.56.7444 | SISSA 17/97/EP | hep-ph astro-ph | null | Using the results of a high precision calculation of the solar neutrino
survival probability for Earth crossing neutrinos in the case of MSW $\nu_e \to
\nu_{\mu(\tau)}$ transition solution of the solar neutrino problem, performed
in an earlier study, we derive predictions for the one-year averaged day-night
(D-N) asymmetry in the deformations of the $e^-$ - spectrum to be measured with
the Super - Kamiokande detector, and for the D-N asymmetry in the energy-
integrated one year signal in this detector. The asymmetries are calculated for
solar $\nu_e$ crossing the Earth mantle only, the core and the (mantle + core)
for a large representative set of values of the MSW transition parameters
$\Delta m^2$ and $\sin^2 2\theta_v$ from the ``conservative'' MSW solution
region obtained by taking into account possible uncertainties in the values of
the $^8$B and $^7$Be neutrino fluxes. The effect of the uncertainties in the
value of the bulk matter density and in the chemical composition of the core,
on the D-N asymmetry predictions is discussed. It is shown, in particular, that
for $\sin^2 2\theta_v \leq 0.013$ the one year average D-N asymmetry for
neutrinos crossing the Earth core can be larger than the asymmetry for (only
mantle crossing + core crossing) neutrinos by a factor of up to six. Iso -
(D-N) asymmetry contours in the $\Delta m^2 - \sin^2 2\theta_v$ plane for the
Super - Kamiokande detector are derived in the region $\sin^2 2\theta_v \gsim
10^{-4}$ for only mantle crossing, core crossing and (only mantle crossing +
core crossing) neutrinos. Our results indicate that the Super - Kamiokande
experiment might be able to test the $\sin^2 2\theta_v \le 0.01$ region of the
MSW solution of the solar neutrino problem by performing selective D-N
asymmetry measurements.
| [
{
"created": "Thu, 22 May 1997 16:11:16 GMT",
"version": "v1"
}
] | 2016-08-25 | [
[
"Maris",
"M.",
""
],
[
"Petcov",
"S. T.",
""
]
] | Using the results of a high precision calculation of the solar neutrino survival probability for Earth crossing neutrinos in the case of MSW $\nu_e \to \nu_{\mu(\tau)}$ transition solution of the solar neutrino problem, performed in an earlier study, we derive predictions for the one-year averaged day-night (D-N) asymmetry in the deformations of the $e^-$ - spectrum to be measured with the Super - Kamiokande detector, and for the D-N asymmetry in the energy- integrated one year signal in this detector. The asymmetries are calculated for solar $\nu_e$ crossing the Earth mantle only, the core and the (mantle + core) for a large representative set of values of the MSW transition parameters $\Delta m^2$ and $\sin^2 2\theta_v$ from the ``conservative'' MSW solution region obtained by taking into account possible uncertainties in the values of the $^8$B and $^7$Be neutrino fluxes. The effect of the uncertainties in the value of the bulk matter density and in the chemical composition of the core, on the D-N asymmetry predictions is discussed. It is shown, in particular, that for $\sin^2 2\theta_v \leq 0.013$ the one year average D-N asymmetry for neutrinos crossing the Earth core can be larger than the asymmetry for (only mantle crossing + core crossing) neutrinos by a factor of up to six. Iso - (D-N) asymmetry contours in the $\Delta m^2 - \sin^2 2\theta_v$ plane for the Super - Kamiokande detector are derived in the region $\sin^2 2\theta_v \gsim 10^{-4}$ for only mantle crossing, core crossing and (only mantle crossing + core crossing) neutrinos. Our results indicate that the Super - Kamiokande experiment might be able to test the $\sin^2 2\theta_v \le 0.01$ region of the MSW solution of the solar neutrino problem by performing selective D-N asymmetry measurements. |
hep-ph/0610018 | Alessandro Vicini | C.M. Carloni Calame, G. Montagna, O. Nicrosini, A. Vicini | Electroweak corrections to the charged current Drell-Yan process | 4 pages, talk given at IFAE 2006, Pavia, April 19-21 2006 | null | null | null | hep-ph | null | A concise review about the status of the calculation of radiative corrections
to the Drell-Yan processes is presented. The effect of matching together exact
electroweak O(alpha) corrections with higher-order QED effects due to multiple
photon emission is displayed in some physical distributions in the charged
current channel, which have obtained with the new version of the event
generator HORACE.
| [
{
"created": "Mon, 2 Oct 2006 12:36:11 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Calame",
"C. M. Carloni",
""
],
[
"Montagna",
"G.",
""
],
[
"Nicrosini",
"O.",
""
],
[
"Vicini",
"A.",
""
]
] | A concise review about the status of the calculation of radiative corrections to the Drell-Yan processes is presented. The effect of matching together exact electroweak O(alpha) corrections with higher-order QED effects due to multiple photon emission is displayed in some physical distributions in the charged current channel, which have obtained with the new version of the event generator HORACE. |
hep-ph/0511263 | Jorge Casalderrey-Solana | J.Casalderrey-Solana, E.V. Shuryak | Conical flow in a medium with variable speed of sound | null | null | null | null | hep-ph | null | In high energy nuclear collisions, QCD jets deposit a large fraction of their
energy into the produced matter. It has been proposed that as such matter
behaves as a liquid with a very small viscosity, a fraction of this energy goes
into a collective excitation called the ``conical flow'', similar e.g. to the
sonic booms generated by the supersonic planes. In this work we study the
effect of time-dependent speed of sound on the development of the conical wave.
We show that the expansion of matter and the decrease of $c_s$ leads to an
increase of observable manifestations of the conical flow. We also show that if
the QCD phase transition is of the first order (and thus with vanishing speed
of sound in the mixed phase) the wave must split into two, with opposite
directions. We then argue that it is not the case experimentally, which
supports the conclusion that the QCD phase transition is $not$ of the first
order.
| [
{
"created": "Tue, 22 Nov 2005 21:01:59 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Casalderrey-Solana",
"J.",
""
],
[
"Shuryak",
"E. V.",
""
]
] | In high energy nuclear collisions, QCD jets deposit a large fraction of their energy into the produced matter. It has been proposed that as such matter behaves as a liquid with a very small viscosity, a fraction of this energy goes into a collective excitation called the ``conical flow'', similar e.g. to the sonic booms generated by the supersonic planes. In this work we study the effect of time-dependent speed of sound on the development of the conical wave. We show that the expansion of matter and the decrease of $c_s$ leads to an increase of observable manifestations of the conical flow. We also show that if the QCD phase transition is of the first order (and thus with vanishing speed of sound in the mixed phase) the wave must split into two, with opposite directions. We then argue that it is not the case experimentally, which supports the conclusion that the QCD phase transition is $not$ of the first order. |
hep-ph/0101229 | Per Osland | Ilya F. Ginzburg (Novosibirsk), Maria Krawczyk (Warsaw), Per Osland
(Bergen) | Potential of Photon Collider in resolving SM-like scenarios | 9 pages, LaTeX, with figures | Nucl.Instrum.Meth. A472 (2001) 149-154 | 10.1016/S0168-9002(01)01174-3 | null | hep-ph | null | After operations at the LHC and e^+e^- Linear Colliders it may be found that
a Standard-Model-like scenario is realized. In this scenario no new particle
will be discovered, except a single Higgs boson having partial widths or
coupling constants squared with fundamental particles close, within anticipated
experimental uncertainty, to those of the SM. Experiments at a Photon Collider
can resolve whether the SM model or e.g. the Two Higgs Doublet Model is
realized in Nature.
For the SM-like version of the 2HDM (II) we study the loop couplings of the
Higgs boson with \gamma\gamma and Z \gamma, and also with gluons. The deviation
of the two-photon width from its SM value is generally higher than the expected
inaccuracy in the measurement of \Gamma_{\gamma \gamma} at a Photon Collider.
The result is sensitive to the parameters of the Higgs self interaction.
| [
{
"created": "Sat, 20 Jan 2001 12:33:05 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Ginzburg",
"Ilya F.",
"",
"Novosibirsk"
],
[
"Krawczyk",
"Maria",
"",
"Warsaw"
],
[
"Osland",
"Per",
"",
"Bergen"
]
] | After operations at the LHC and e^+e^- Linear Colliders it may be found that a Standard-Model-like scenario is realized. In this scenario no new particle will be discovered, except a single Higgs boson having partial widths or coupling constants squared with fundamental particles close, within anticipated experimental uncertainty, to those of the SM. Experiments at a Photon Collider can resolve whether the SM model or e.g. the Two Higgs Doublet Model is realized in Nature. For the SM-like version of the 2HDM (II) we study the loop couplings of the Higgs boson with \gamma\gamma and Z \gamma, and also with gluons. The deviation of the two-photon width from its SM value is generally higher than the expected inaccuracy in the measurement of \Gamma_{\gamma \gamma} at a Photon Collider. The result is sensitive to the parameters of the Higgs self interaction. |
1802.02729 | Harleen Dahiya Dr. | Navdeep Kaur and Harleen Dahiya | Transverse momentum distributions of electron in simulated QED model | 4 pages, 3 figures. Prepared for proceedings of Light Cone Conference
2017 held in Mumbai September 18-22, 2017 | Few Body Syst. 59 (2018) 39 | 10.1007/s00601-018-1359-x | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the present work, we have studied the transverse momentum distributions
(TMDs) for the electron in simulated QED model. We have used the overlap
representation of light-front wave functions (LFWFs) where the spin-1/2
relativistic composite system consists of spin-1/2 fermion and spin-1 vector
boson. The results have been obtained for T-even TMDs in transverse momentum
plane for fixed value of longitudinal momentum fraction $x$.
| [
{
"created": "Thu, 8 Feb 2018 07:15:29 GMT",
"version": "v1"
}
] | 2018-03-28 | [
[
"Kaur",
"Navdeep",
""
],
[
"Dahiya",
"Harleen",
""
]
] | In the present work, we have studied the transverse momentum distributions (TMDs) for the electron in simulated QED model. We have used the overlap representation of light-front wave functions (LFWFs) where the spin-1/2 relativistic composite system consists of spin-1/2 fermion and spin-1 vector boson. The results have been obtained for T-even TMDs in transverse momentum plane for fixed value of longitudinal momentum fraction $x$. |
1404.5626 | Alexander Kartavtsev | Alexander Kartavtsev | Relating quantum mechanics and kinetics of neutrino oscillations | 29 pages, matches the published version, title changed, extended
discussion of neutrino propagation in matter, appendix added | High Energ. Phys. (2020) 2020: 138 | 10.1007/JHEP01(2020)138 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Simultaneous treatment of neutrino oscillations and collisions in
astrophysical environments requires the use of (quantum) kinetic equations.
Despite major advances in the field of quantum kinetics, the structure of the
kinetic equations and their consistency with the uncertainty principle are
still debated. The goals of the present work are threefold. First, it clarifies
the structure of the Liouville term in the presence of mixing. Second, we
derive evolution equation for neutrinos propagating in vacuum or matter from
the Schrodinger equation and show that in the relativistic limit its form
matches the form of the (collisionless part of the) kinetic equation derived by
Sigl and Raffelt. Third, by constructing solutions of the evolution equation
from the known solutions of the Schrodinger equation, we show that the former
also admits solutions consistent with the uncertainty principle and accounts
for neutrino wave packet separation. The obtained results speak in favor of a
(quantum) kinetic approach to the analysis of neutrino propagation in exploding
supernovae where neutrino oscillations and collisions, as well as the effect of
wave packet separation, might be equally important.
| [
{
"created": "Tue, 22 Apr 2014 20:00:16 GMT",
"version": "v1"
},
{
"created": "Thu, 27 Dec 2018 23:07:07 GMT",
"version": "v2"
},
{
"created": "Fri, 24 Jan 2020 16:21:56 GMT",
"version": "v3"
}
] | 2020-01-27 | [
[
"Kartavtsev",
"Alexander",
""
]
] | Simultaneous treatment of neutrino oscillations and collisions in astrophysical environments requires the use of (quantum) kinetic equations. Despite major advances in the field of quantum kinetics, the structure of the kinetic equations and their consistency with the uncertainty principle are still debated. The goals of the present work are threefold. First, it clarifies the structure of the Liouville term in the presence of mixing. Second, we derive evolution equation for neutrinos propagating in vacuum or matter from the Schrodinger equation and show that in the relativistic limit its form matches the form of the (collisionless part of the) kinetic equation derived by Sigl and Raffelt. Third, by constructing solutions of the evolution equation from the known solutions of the Schrodinger equation, we show that the former also admits solutions consistent with the uncertainty principle and accounts for neutrino wave packet separation. The obtained results speak in favor of a (quantum) kinetic approach to the analysis of neutrino propagation in exploding supernovae where neutrino oscillations and collisions, as well as the effect of wave packet separation, might be equally important. |
1807.07788 | Daniel Pablos | Jorge Casalderrey-Solana, Zachary Hulcher, Guilherme Milhano, Daniel
Pablos and Krishna Rajagopal | A simultaneous understanding of jet and hadron suppression | 4 pages, 2 figures, Quark Matter 2018 proceedings | null | 10.1016/j.nuclphysa.2018.12.014 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the context of the hybrid strong/weak coupling model for jet quenching, we
perform a global fit to hadron and jet data in the most central bins both at
RHIC and LHC. The qualitative and quantitative success of the analysis is
attributed to the fact that the model correctly captures the fact that wider
jets lose, on average, more energy than the narrower ones, to which high energy
hadrons belong. We show how one can understand the relative jet and hadron
suppression by analyzing the jet fragmentation functions, and also discuss the
role of plasma finite resolution effects.
| [
{
"created": "Fri, 20 Jul 2018 11:14:27 GMT",
"version": "v1"
}
] | 2019-02-20 | [
[
"Casalderrey-Solana",
"Jorge",
""
],
[
"Hulcher",
"Zachary",
""
],
[
"Milhano",
"Guilherme",
""
],
[
"Pablos",
"Daniel",
""
],
[
"Rajagopal",
"Krishna",
""
]
] | In the context of the hybrid strong/weak coupling model for jet quenching, we perform a global fit to hadron and jet data in the most central bins both at RHIC and LHC. The qualitative and quantitative success of the analysis is attributed to the fact that the model correctly captures the fact that wider jets lose, on average, more energy than the narrower ones, to which high energy hadrons belong. We show how one can understand the relative jet and hadron suppression by analyzing the jet fragmentation functions, and also discuss the role of plasma finite resolution effects. |
1511.02785 | Samuel Wallon | R. Boussarie, A. V. Grabovsky, L. Szymanowski and S. Wallon | Diffractive production of jets at high-energy in the QCD shock-wave
approach | 10 pages, 6 figures; proceedings of PHOTON 2015: International
Conference on the Structure and the Interactions of the Photon, Novosibirsk,
Russia, 15 - 19 June, 2015 | null | null | LPT-Orsay-15-82 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In view of future phenomenological applications, we study the impact factor
for the photon to quark, antiquark and gluon transition within Balitsky's
shock-wave formalism. The aim of the present program is to extend existing
results beyond approximations discussed in the literature. We present our
results of the real contribution, and report on recent progress in calculating
the virtual contributions for the photon to quark, antiquark transition.
| [
{
"created": "Mon, 9 Nov 2015 17:54:10 GMT",
"version": "v1"
}
] | 2015-11-10 | [
[
"Boussarie",
"R.",
""
],
[
"Grabovsky",
"A. V.",
""
],
[
"Szymanowski",
"L.",
""
],
[
"Wallon",
"S.",
""
]
] | In view of future phenomenological applications, we study the impact factor for the photon to quark, antiquark and gluon transition within Balitsky's shock-wave formalism. The aim of the present program is to extend existing results beyond approximations discussed in the literature. We present our results of the real contribution, and report on recent progress in calculating the virtual contributions for the photon to quark, antiquark transition. |
hep-ph/9303202 | null | M. Carena, S. Pokorski and C.E.M. Wagner | On the Unification of Couplings in the Minimal Supersymmetric Standard
Model | 40 pages, MPI-Ph/93-10 | Nucl.Phys.B406:59-89,1993 | 10.1016/0550-3213(93)90161-H | null | hep-ph | null | The unification of gauge and Yukawa couplings within the minimal
supersymmetric standard model is studied at the two loop level. We derive an
expression for the effective scale, $T_{SUSY}$, which characterizes the
supersymmetric particle threshold corrections to the gauge couplings, and
demonstrate that $T_{SUSY}$ is only slightly dependent on the squark and
slepton masses, and strongly dependent on the Higgsino masses as well as on the
mass ratio of the gauginos of the strong and weak interactions. Moreover, the
value of the top quark Yukawa coupling necessary to achieve the unification of
bottom and tau Yukawa couplings is also governed by $T_{SUSY}$, and it yields
predictions for the top quark mass which are close to the quasi infrared fixed
point results associated with the triviality bounds on this quantity. From the
requirement of perturbative consistency of the top quark Yukawa sector of the
theory, we obtain constraints on the allowed splitting of the supersymmetric
spectrum, which, for certain values of the running bottom quark mass, are
stronger than those ones coming from the experimental constraints on the strong
gauge coupling.
| [
{
"created": "Mon, 1 Mar 1993 23:42:02 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Carena",
"M.",
""
],
[
"Pokorski",
"S.",
""
],
[
"Wagner",
"C. E. M.",
""
]
] | The unification of gauge and Yukawa couplings within the minimal supersymmetric standard model is studied at the two loop level. We derive an expression for the effective scale, $T_{SUSY}$, which characterizes the supersymmetric particle threshold corrections to the gauge couplings, and demonstrate that $T_{SUSY}$ is only slightly dependent on the squark and slepton masses, and strongly dependent on the Higgsino masses as well as on the mass ratio of the gauginos of the strong and weak interactions. Moreover, the value of the top quark Yukawa coupling necessary to achieve the unification of bottom and tau Yukawa couplings is also governed by $T_{SUSY}$, and it yields predictions for the top quark mass which are close to the quasi infrared fixed point results associated with the triviality bounds on this quantity. From the requirement of perturbative consistency of the top quark Yukawa sector of the theory, we obtain constraints on the allowed splitting of the supersymmetric spectrum, which, for certain values of the running bottom quark mass, are stronger than those ones coming from the experimental constraints on the strong gauge coupling. |
1112.0091 | Soo-hyeon Nam | Kihyeon Cho and Soo-hyeon Nam | Right-handed current contributions in B -> K pi decays | 9 pages, 4 figures, Numerical results changed with updated
experimental data, journal version | null | 10.1103/PhysRevD.88.035012 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We reexamine the right-handed current effects in $b \to s$ transitions in
nonmanifest left-right models. Using the effective Hamiltonian approach
including all possible low-energy operators, we obtain especially the B \to K
\pi decay amplitudes including annihilation contributions, and investigate the
right-handed current contributions to CP asymmetries in $B \to K \pi$ decays.
Taking into account the constraints from global analysis of muon decay
measurements, |V_{ub}| measurements in inclusive and exclusive B decays, and
$B_s^0-\bar{B_s^0}$ mixing measurements, we find the allowed regions of new
physics parameters satisfying the current experimental data.
| [
{
"created": "Thu, 1 Dec 2011 06:24:44 GMT",
"version": "v1"
},
{
"created": "Mon, 8 Jul 2013 14:01:36 GMT",
"version": "v2"
},
{
"created": "Mon, 12 Aug 2013 07:25:00 GMT",
"version": "v3"
}
] | 2013-08-13 | [
[
"Cho",
"Kihyeon",
""
],
[
"Nam",
"Soo-hyeon",
""
]
] | We reexamine the right-handed current effects in $b \to s$ transitions in nonmanifest left-right models. Using the effective Hamiltonian approach including all possible low-energy operators, we obtain especially the B \to K \pi decay amplitudes including annihilation contributions, and investigate the right-handed current contributions to CP asymmetries in $B \to K \pi$ decays. Taking into account the constraints from global analysis of muon decay measurements, |V_{ub}| measurements in inclusive and exclusive B decays, and $B_s^0-\bar{B_s^0}$ mixing measurements, we find the allowed regions of new physics parameters satisfying the current experimental data. |
hep-ph/9608337 | null | J.G. K\"orner | Constituent Quark Model Approach to Heavy Baryon Transitions | Invited talk given at the III German-Russian Workshop on Heavy Quark
Physics, Dubna, Russia, May 20-22, 1996, to appear in the Proceedings. 6
pages and 1 figure | null | null | Mainz MZ-TH/96-24 | hep-ph | null | I discuss the structure of current-induced bottom baryon to charm baryon
transitions, and the structure of pion and photon transitions between heavy
charm or bottom baryons in the Heavy Quark Symmetry (HQS) limit as
$m_Q\rightarrow\infty$. By doing a spin-parity analysis I derive a general
formula which allows one to enumerate the independent HQS amplitudes in the
three types of transitions. I go on to show that use of the constituent quark
model for the light-side diquark transitions leads to a considerable reduction
in the number of independent amplitudes derived in the HQS limit. The
discussion includes the ground state $s$-wave as well as the $p$-wave heavy
baryons.
| [
{
"created": "Thu, 15 Aug 1996 16:28:24 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Körner",
"J. G.",
""
]
] | I discuss the structure of current-induced bottom baryon to charm baryon transitions, and the structure of pion and photon transitions between heavy charm or bottom baryons in the Heavy Quark Symmetry (HQS) limit as $m_Q\rightarrow\infty$. By doing a spin-parity analysis I derive a general formula which allows one to enumerate the independent HQS amplitudes in the three types of transitions. I go on to show that use of the constituent quark model for the light-side diquark transitions leads to a considerable reduction in the number of independent amplitudes derived in the HQS limit. The discussion includes the ground state $s$-wave as well as the $p$-wave heavy baryons. |
hep-ph/9311250 | Marek Karliner | Y. Frishman, A. Hanany and M. Karliner | Quark Solitons from Effective Action of QCD | 19 pages (phyzzx macropackage) WIS-93/110/Nov-PH, TAUP 2117-93. Some
sign changes, one sentence added following eq(3.9), and one ref. [23] added | Nucl.Phys. B424 (1994) 3-17 | 10.1016/0550-3213(94)90085-X | null | hep-ph | null | We derive an effective low energy action for QCD in 4 dimensions. The low
energy dynamics is described by chiral fields transforming non-trivially under
both color and flavor. We use the method of anomaly integration from the QCD
action. The solitons of the theory have the quantum numbers of quarks. They are
expected to be the constituent quarks of hadrons. In two dimensions our result
is exact, namely the bosonic gauged action of WZW.
| [
{
"created": "Tue, 9 Nov 1993 19:44:00 GMT",
"version": "v1"
},
{
"created": "Fri, 3 Dec 1993 12:50:00 GMT",
"version": "v2"
}
] | 2009-10-22 | [
[
"Frishman",
"Y.",
""
],
[
"Hanany",
"A.",
""
],
[
"Karliner",
"M.",
""
]
] | We derive an effective low energy action for QCD in 4 dimensions. The low energy dynamics is described by chiral fields transforming non-trivially under both color and flavor. We use the method of anomaly integration from the QCD action. The solitons of the theory have the quantum numbers of quarks. They are expected to be the constituent quarks of hadrons. In two dimensions our result is exact, namely the bosonic gauged action of WZW. |
0708.2079 | Apostolos Pilaftsis | John Ellis, Jae Sik Lee and Apostolos Pilaftsis | B-Meson Observables in the Maximally CP-Violating MSSM with Minimal
Flavour Violation | 47 pages, 8 eps figures, comments and references added, accepted for
publication in Physical Review D, Eq.(3.2) corrected | Phys.Rev.D76:115011,2007 | 10.1103/PhysRevD.76.115011 | CERN-PH-TH/2007-136, MAN/HEP/2007/13 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Additional sources of CP violation in the MSSM may affect B-meson mixings and
decays, even in scenarios with minimal flavour violation (MFV). We formulate
the maximally CP-violating and minimally flavour-violating (MCPMFV) variant of
the MSSM, which has 19 parameters, including 6 phases that violate CP. We then
develop a manifestly flavour-covariant effective Lagrangian formalism for
calculating Higgs-mediated FCNC observables in the MSSM at large tan(beta), and
analyze within the MCPMFV framework FCNC and other processes involving B
mesons. We include a new class of dominant subleading contributions due to
non-decoupling effects of the third-generation quarks. We present illustrative
numerical results that include effects of the CP-odd MCPMFV parameters on Higgs
and sparticle masses, the B_s and B_d mass differences, and on the decays B_s
--> mu+ mu-, B_u --> tau nu and b --> s gamma. We use these results to derive
illustrative constraints on the MCPMFV parameters imposed by D0, CDF, BELLE and
BABAR measurements of B mesons, demonstrating how a potentially observable
contribution to the CP asymmetry in the b --> s gamma decay may arise in the
MSSM with MCPMFV.
| [
{
"created": "Wed, 15 Aug 2007 18:47:54 GMT",
"version": "v1"
},
{
"created": "Sat, 27 Oct 2007 06:38:24 GMT",
"version": "v2"
},
{
"created": "Tue, 20 Nov 2007 04:56:49 GMT",
"version": "v3"
},
{
"created": "Fri, 12 Sep 2008 15:15:47 GMT",
"version": "v4"
}
] | 2008-11-26 | [
[
"Ellis",
"John",
""
],
[
"Lee",
"Jae Sik",
""
],
[
"Pilaftsis",
"Apostolos",
""
]
] | Additional sources of CP violation in the MSSM may affect B-meson mixings and decays, even in scenarios with minimal flavour violation (MFV). We formulate the maximally CP-violating and minimally flavour-violating (MCPMFV) variant of the MSSM, which has 19 parameters, including 6 phases that violate CP. We then develop a manifestly flavour-covariant effective Lagrangian formalism for calculating Higgs-mediated FCNC observables in the MSSM at large tan(beta), and analyze within the MCPMFV framework FCNC and other processes involving B mesons. We include a new class of dominant subleading contributions due to non-decoupling effects of the third-generation quarks. We present illustrative numerical results that include effects of the CP-odd MCPMFV parameters on Higgs and sparticle masses, the B_s and B_d mass differences, and on the decays B_s --> mu+ mu-, B_u --> tau nu and b --> s gamma. We use these results to derive illustrative constraints on the MCPMFV parameters imposed by D0, CDF, BELLE and BABAR measurements of B mesons, demonstrating how a potentially observable contribution to the CP asymmetry in the b --> s gamma decay may arise in the MSSM with MCPMFV. |
1909.10384 | Yu. A. Simonov | M. S. Lukashov and Yu. A. Simonov | Scalar mesons in the chiral theory with quark degrees of freedom | v5: 29 pages, 6 figures; version accepted to PRD, new equations with
explanations are added, several important insertions are made, the list of
references is correspondingly enlarged | null | 10.1103/PhysRevD.101.094028 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The Chiral Confining Lagrangian, based on the chiral theory with quark
degrees of freedom, is used to study the spectroscopy of scalar mesons. The
formalism does not contain arbitrary fitting parameters and takes into account
infinite number of transitions from meson-meson to quark-antiquark states.
Starting from known $q\bar q$ poles the transition coefficients ensure the
strong shift of the poles for the $\pi\pi$ and much smaller shift for the
$K\bar K$ systems. The resulting amplitudes $f_{\pi\pi}$ and $f_{K\bar K}$ are
calculated in terms of the $q\bar q$ and the free meson Green's functions. With
the account of the $\pi\pi/K\bar{K}$ channel coupling one obtains two
resonances: a wide resonance $E_1$ in the range 500-700 MeV and narrow $E_2 $
near 1 GeV, which can be associated with $f_0(500)$ and $f_0(980)$. A similar
analysis, applied to the $I=1$ channel, shows that in this case two very close
poles in different sheets appear near $E=980$ MeV, which can be associated with
the $a_0 (980)$ resonance. The obtained $\pi\pi$ interaction amplitudes,
$\operatorname{Re} f_{\pi\pi} (E)$ and $\operatorname{Im} f_{\pi\pi}(E)$ are
compared with the known data.
| [
{
"created": "Mon, 23 Sep 2019 14:25:42 GMT",
"version": "v1"
},
{
"created": "Mon, 30 Sep 2019 14:22:19 GMT",
"version": "v2"
},
{
"created": "Mon, 14 Oct 2019 15:02:10 GMT",
"version": "v3"
},
{
"created": "Tue, 25 Feb 2020 20:50:19 GMT",
"version": "v4"
},
{
"c... | 2020-06-24 | [
[
"Lukashov",
"M. S.",
""
],
[
"Simonov",
"Yu. A.",
""
]
] | The Chiral Confining Lagrangian, based on the chiral theory with quark degrees of freedom, is used to study the spectroscopy of scalar mesons. The formalism does not contain arbitrary fitting parameters and takes into account infinite number of transitions from meson-meson to quark-antiquark states. Starting from known $q\bar q$ poles the transition coefficients ensure the strong shift of the poles for the $\pi\pi$ and much smaller shift for the $K\bar K$ systems. The resulting amplitudes $f_{\pi\pi}$ and $f_{K\bar K}$ are calculated in terms of the $q\bar q$ and the free meson Green's functions. With the account of the $\pi\pi/K\bar{K}$ channel coupling one obtains two resonances: a wide resonance $E_1$ in the range 500-700 MeV and narrow $E_2 $ near 1 GeV, which can be associated with $f_0(500)$ and $f_0(980)$. A similar analysis, applied to the $I=1$ channel, shows that in this case two very close poles in different sheets appear near $E=980$ MeV, which can be associated with the $a_0 (980)$ resonance. The obtained $\pi\pi$ interaction amplitudes, $\operatorname{Re} f_{\pi\pi} (E)$ and $\operatorname{Im} f_{\pi\pi}(E)$ are compared with the known data. |
hep-ph/9905230 | Peter Landshoff | P V Landshoff | Urgent problems at small x | Talk at DIS99, Zeuthen, April 1999. 3 pages, latex, 3 figures | Nucl.Phys.Proc.Suppl.79:204-206,1999 | 10.1016/S0920-5632(99)00676-3 | DAMTP-1999-58 | hep-ph | null | Regge theory provides an excellent fit to small-x structure-function data
from Q^2=0 right up to the highest available values, but it also teaches us
that conventional approaches to perturbative evolution are incorrect.
| [
{
"created": "Tue, 4 May 1999 09:05:17 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"Landshoff",
"P V",
""
]
] | Regge theory provides an excellent fit to small-x structure-function data from Q^2=0 right up to the highest available values, but it also teaches us that conventional approaches to perturbative evolution are incorrect. |
2309.03655 | Avijit Hazra Mr. | Avijit Hazra, Thejus Mary S., Neelesh Sharma, Rohit Dhir | $B_c$ to $A$ Transition Form Factors and Semileptonic Decays in
Self-consistent Covariant Light-front Approach | 68 pages, 16 figures, 8 tables. Revised manuscript | null | null | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | We present a comprehensive analysis of the semileptonic weak decays of $B_c$
meson decaying to axial-vector ($A$) mesons for bottom-conserving and
bottom-changing decay modes. We employ self-consistent covariant light-front
quark model (CLFQM) that uses type-II correspondence to eliminate
inconsistencies in the traditional type-I CLFQM. As a fresh attempt, we test
the self-consistency in CLFQM through type-II correspondence for $B_c \to A$
meson transition form factors. We establish that in type-II correspondence the
form factors for longitudinal and transverse polarization states are
numerically equal and are free from zero-mode contributions, which confirms the
self-consistency of type-II correspondence for $B_c \to A$ transition form
factors. Furthermore, we ascertain that the problems of inconsistency and
violation of covariance of CLFQM within the type-I correspondence are resolved
in type-II correspondence for $B_c \to A$ transitions. We thoroughly
investigate the effects of self-consistency between type-I and type-II schemes
using a comparative analysis. We also study the $q^2$ dependence of the form
factors in weak hadronic currents for the whole accessible kinematic range $0
\leqslant q^2 \leqslant q^2_{max}$ for both bottom-conserving as well as
bottom-changing transitions. In addition, we extend our analysis to predict the
branching ratios of the semileptonic weak decays of $B_c$ meson involving
axial-vector meson in the final state to quantify the effects of
self-consistency in these decays that were not studied before. We evaluate the
lepton mass effect on these branching ratios and various other important
physical observables, such as forward-backward asymmetries, lepton-side
convexity parameter, asymmetry parameter, and longitudinal polarization
asymmetries and fractions. Finally, we obtain the lepton flavor universality
ratios for various decays.
| [
{
"created": "Thu, 7 Sep 2023 11:49:01 GMT",
"version": "v1"
},
{
"created": "Mon, 29 Jan 2024 13:22:36 GMT",
"version": "v2"
},
{
"created": "Sun, 12 May 2024 14:37:32 GMT",
"version": "v3"
}
] | 2024-05-14 | [
[
"Hazra",
"Avijit",
""
],
[
"S.",
"Thejus Mary",
""
],
[
"Sharma",
"Neelesh",
""
],
[
"Dhir",
"Rohit",
""
]
] | We present a comprehensive analysis of the semileptonic weak decays of $B_c$ meson decaying to axial-vector ($A$) mesons for bottom-conserving and bottom-changing decay modes. We employ self-consistent covariant light-front quark model (CLFQM) that uses type-II correspondence to eliminate inconsistencies in the traditional type-I CLFQM. As a fresh attempt, we test the self-consistency in CLFQM through type-II correspondence for $B_c \to A$ meson transition form factors. We establish that in type-II correspondence the form factors for longitudinal and transverse polarization states are numerically equal and are free from zero-mode contributions, which confirms the self-consistency of type-II correspondence for $B_c \to A$ transition form factors. Furthermore, we ascertain that the problems of inconsistency and violation of covariance of CLFQM within the type-I correspondence are resolved in type-II correspondence for $B_c \to A$ transitions. We thoroughly investigate the effects of self-consistency between type-I and type-II schemes using a comparative analysis. We also study the $q^2$ dependence of the form factors in weak hadronic currents for the whole accessible kinematic range $0 \leqslant q^2 \leqslant q^2_{max}$ for both bottom-conserving as well as bottom-changing transitions. In addition, we extend our analysis to predict the branching ratios of the semileptonic weak decays of $B_c$ meson involving axial-vector meson in the final state to quantify the effects of self-consistency in these decays that were not studied before. We evaluate the lepton mass effect on these branching ratios and various other important physical observables, such as forward-backward asymmetries, lepton-side convexity parameter, asymmetry parameter, and longitudinal polarization asymmetries and fractions. Finally, we obtain the lepton flavor universality ratios for various decays. |
hep-ph/0312183 | Jorge Portoles | D. Gomez Dumm (1), A. Pich (2), J. Portoles (2) ((1) IFLP-La Plata
(Argentina), (2) IFIC-Valencia (Spain)) | tau -> (3 pions) nu_tau decays in the Resonance Effective Theory | 24 pages, 7 figures | Phys.Rev.D69:073002,2004 | 10.1103/PhysRevD.69.073002 | IFIC/03-38, FTUV/03-1215 | hep-ph hep-ex | null | tau -> (3 pions) nu_tau decays are analysed within the framework of the
resonance effective theory of QCD. We work out the relevant Lagrangian that
describes the axial-vector current hadronization contributing to these
processes, in particular the local a_1(1260)-rho(770)-Goldstone interactions.
The new coupling constants are constrained by imposing the asymptotic behaviour
of the corresponding spectral function within QCD. Hence we compare the
theoretical framework with the experimental data, obtaining a good quality fit
from the ALEPH spectral function and branching ratio. We also get values for
the mass and on-shell width of the a_1(1260) resonance. In this way we are able
to provide the structure functions that have been measured by OPAL and CLEO-II
and we find an excellent agreement.
| [
{
"created": "Mon, 15 Dec 2003 14:52:27 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Dumm",
"D. Gomez",
""
],
[
"Pich",
"A.",
""
],
[
"Portoles",
"J.",
""
]
] | tau -> (3 pions) nu_tau decays are analysed within the framework of the resonance effective theory of QCD. We work out the relevant Lagrangian that describes the axial-vector current hadronization contributing to these processes, in particular the local a_1(1260)-rho(770)-Goldstone interactions. The new coupling constants are constrained by imposing the asymptotic behaviour of the corresponding spectral function within QCD. Hence we compare the theoretical framework with the experimental data, obtaining a good quality fit from the ALEPH spectral function and branching ratio. We also get values for the mass and on-shell width of the a_1(1260) resonance. In this way we are able to provide the structure functions that have been measured by OPAL and CLEO-II and we find an excellent agreement. |
hep-ph/0703151 | Verissimo Aquino de | Verissimo M. de Aquino and J. S. S. de Oliveira | Aproximative solutions to the neutrino oscillation problem in matter | 12 pages, 5 figures | Phys.Scripta77:045101,2008 | 10.1088/0031-8949/77/04/045101 | null | hep-ph | null | We present approximative solutions to the neutrino evolution equation
calculated by different methods. In a two neutrino framework, using the
physical parameters which gives the main effects to neutrino oscillations from
nu{e} to another flavors for L=3000Km and E=1GeV, the results for the
transition probability calculated by using series solutions, by to take the
neutrino evolution operator as a product of ordered partial operators and by
numerical methods, for a linearly and sinusoidally varying matter density are
compared. The extension to an arbitrary density profile is discussed and the
evolution operator as a product of partial operators in the three neutrino case
is obtained.
| [
{
"created": "Wed, 14 Mar 2007 16:49:25 GMT",
"version": "v1"
},
{
"created": "Wed, 21 Mar 2007 12:37:09 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"de Aquino",
"Verissimo M.",
""
],
[
"de Oliveira",
"J. S. S.",
""
]
] | We present approximative solutions to the neutrino evolution equation calculated by different methods. In a two neutrino framework, using the physical parameters which gives the main effects to neutrino oscillations from nu{e} to another flavors for L=3000Km and E=1GeV, the results for the transition probability calculated by using series solutions, by to take the neutrino evolution operator as a product of ordered partial operators and by numerical methods, for a linearly and sinusoidally varying matter density are compared. The extension to an arbitrary density profile is discussed and the evolution operator as a product of partial operators in the three neutrino case is obtained. |
2008.03527 | Oleksandr Tomalak | Oleksandr Tomalak | Axial and pseudoscalar form factors from charged current quasielastic
neutrino-nucleon scattering | 30 pages, 18 figures, v2: journal version; structure and references
added; figures, text and expressions added, corrected and described | Phys. Rev. D 103, 013006 (2021) | 10.1103/PhysRevD.103.013006 | FERMILAB-PUB-20-418-T | hep-ph hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the scattering of neutrinos on polarized and unpolarized free
nucleons, and also the polarization of recoil particles in these scatters. In
contrast to electromagnetic processes, the parity-violating weak interaction
gives rise to large spin asymmetries at leading order. Future polarization
measurements could provide independent access to the proton axial structure and
allow the first extraction of the pseudoscalar form factor from neutrino data
without the conventional partially conserved axial current (PCAC) ansatz and
assumptions about the pion-pole dominance. The pseudoscalar form factor can be
accessed with precise measurements with muon (anti)neutrinos of a few hundreds
$\mathrm{MeV}$ of energy or with tau (anti)neutrinos. The axial form factor can
be extracted from scattering measurements using accelerator neutrinos of all
energies.
| [
{
"created": "Sat, 8 Aug 2020 14:00:36 GMT",
"version": "v1"
},
{
"created": "Wed, 13 Jan 2021 05:19:49 GMT",
"version": "v2"
}
] | 2021-01-20 | [
[
"Tomalak",
"Oleksandr",
""
]
] | We study the scattering of neutrinos on polarized and unpolarized free nucleons, and also the polarization of recoil particles in these scatters. In contrast to electromagnetic processes, the parity-violating weak interaction gives rise to large spin asymmetries at leading order. Future polarization measurements could provide independent access to the proton axial structure and allow the first extraction of the pseudoscalar form factor from neutrino data without the conventional partially conserved axial current (PCAC) ansatz and assumptions about the pion-pole dominance. The pseudoscalar form factor can be accessed with precise measurements with muon (anti)neutrinos of a few hundreds $\mathrm{MeV}$ of energy or with tau (anti)neutrinos. The axial form factor can be extracted from scattering measurements using accelerator neutrinos of all energies. |
1908.01389 | Ulrich Jentschura | U. D. Jentschura, I. Nandori and G. Somogyi | Lorentz Breaking and SU(2)_L x U(1)_Y Gauge Invariance for Neutrino
Decays | 18 pages; LaTeX; some typographical errors corrected | Int. J. Mod. Phys. E 28 (2019) 1950072 | 10.1142/S0218301319500721 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Conceivable Lorentz-violating effects in the neutrino sector remain a
research area of great general interest, as they touch upon the very
foundations on which the Standard Model and our general understanding of
fundamental interactions is laid. Here, we investigate the relation of Lorentz
violation in the neutrino sector in light of the fact that neutrinos and
corresponding left-handed charged leptons form SU(2)_L doublets under the
electroweak gauge group. Lorentz-violating effects thus cannot be fully
separated from questions related to gauge invariance. The model dependence of
the effective interaction Lagrangians used in various recent investigations is
investigated, with a special emphasis on neutrino splitting, otherwise known as
neutrino-pair Cerenkov radiation, NPCR, and vacuum pair emission
(electron-positron-pair Cerenkov radiation, LPCR). We investigate two scenarios
in which Lorentz violating effects do not necessarily also break electroweak
gauge invarianceThe first of these involves a restricted set of gauge
transformation, a subgroup of SU(2)_L x U(1)_Y, while in the second,
differential Lorentz violation is exclusively introduced by the mixing of the
neutrino flavor and mass eigenstates. Our study culminates in a model which
fully preserves SU(2)_L x U(1)_Y gauge invariance, involves flavor-dependent
Lorentz-breaking parameters, and still allows for NPCR and LPCR decays to
proceed.
| [
{
"created": "Sun, 4 Aug 2019 19:21:47 GMT",
"version": "v1"
},
{
"created": "Thu, 3 Oct 2019 13:09:32 GMT",
"version": "v2"
}
] | 2020-01-16 | [
[
"Jentschura",
"U. D.",
""
],
[
"Nandori",
"I.",
""
],
[
"Somogyi",
"G.",
""
]
] | Conceivable Lorentz-violating effects in the neutrino sector remain a research area of great general interest, as they touch upon the very foundations on which the Standard Model and our general understanding of fundamental interactions is laid. Here, we investigate the relation of Lorentz violation in the neutrino sector in light of the fact that neutrinos and corresponding left-handed charged leptons form SU(2)_L doublets under the electroweak gauge group. Lorentz-violating effects thus cannot be fully separated from questions related to gauge invariance. The model dependence of the effective interaction Lagrangians used in various recent investigations is investigated, with a special emphasis on neutrino splitting, otherwise known as neutrino-pair Cerenkov radiation, NPCR, and vacuum pair emission (electron-positron-pair Cerenkov radiation, LPCR). We investigate two scenarios in which Lorentz violating effects do not necessarily also break electroweak gauge invarianceThe first of these involves a restricted set of gauge transformation, a subgroup of SU(2)_L x U(1)_Y, while in the second, differential Lorentz violation is exclusively introduced by the mixing of the neutrino flavor and mass eigenstates. Our study culminates in a model which fully preserves SU(2)_L x U(1)_Y gauge invariance, involves flavor-dependent Lorentz-breaking parameters, and still allows for NPCR and LPCR decays to proceed. |
0809.4801 | Matthew Mewes | Matthew Mewes | Bounds on Lorentz and CPT Violation from the Earth-Ionosphere Cavity | 8 pages REVTex | Phys.Rev.D78:096008,2008 | 10.1103/PhysRevD.78.096008 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Electromagnetic resonant cavities form the basis of many tests of Lorentz
invariance involving photons. The effects of some forms of Lorentz violation
scale with cavity size. We investigate possible signals of violations in the
naturally occurring resonances formed in the Earth-ionosphere cavity.
Comparison with observed resonances places the first terrestrial constraints on
coefficients associated with dimension-three Lorentz-violating operators at the
level of 10^{-20} GeV.
| [
{
"created": "Sat, 27 Sep 2008 21:35:13 GMT",
"version": "v1"
}
] | 2010-04-21 | [
[
"Mewes",
"Matthew",
""
]
] | Electromagnetic resonant cavities form the basis of many tests of Lorentz invariance involving photons. The effects of some forms of Lorentz violation scale with cavity size. We investigate possible signals of violations in the naturally occurring resonances formed in the Earth-ionosphere cavity. Comparison with observed resonances places the first terrestrial constraints on coefficients associated with dimension-three Lorentz-violating operators at the level of 10^{-20} GeV. |
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