id stringlengths 9 14 | submitter stringlengths 1 56 ⌀ | authors stringlengths 5 7.68k | title stringlengths 3 299 | comments stringlengths 1 1.15k ⌀ | journal-ref stringlengths 9 298 ⌀ | doi stringlengths 12 97 ⌀ | report-no stringlengths 3 341 ⌀ | categories stringclasses 869 values | license stringclasses 9 values | orig_abstract stringlengths 16 2.44k | versions listlengths 1 39 | update_date stringlengths 10 10 | authors_parsed listlengths 1 565 | abstract stringlengths 13 2.44k |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
2109.14799 | Daiki Suenaga | Daiki Suenaga, Yasufumi Araki, Kei Suzuki, and Shigehiro Yasui | Heavy-quark spin polarization induced by the Kondo effect in a magnetic
field | 19 pages, 12 figures | Phys. Rev. D 105, 074028 (2022) | 10.1103/PhysRevD.105.074028 | RIKEN-iTHEMS-Report-21 | hep-ph hep-lat nucl-th | http://creativecommons.org/licenses/by/4.0/ | We propose a new mechanism of the heavy-quark spin polarization (HQSP) in
quark matter induced by the Kondo effect under external magnetic field. The
Kondo effect is caused by a condensate between a heavy and a light quark called
the Kondo condensate leading to a mixing of the heavy and light quark spins.
Thus the HQSP is driven through the Kondo effect from light quarks coupling
with the magnetic field in quark matter. For demonstration, we employ the
Nambu--Jona-Lasinio type model under a magnetic field, and investigate the HQSP
within the linear response theory with vertex corrections required by the
$U(1)_{\rm EM}$ electromagnetic gauge invariance. As a result, we find that the
HQSP arises significantly with the appearance of the Kondo effect. Our findings
are testable in future sign-problem-free lattice simulations.
| [
{
"created": "Thu, 30 Sep 2021 01:57:12 GMT",
"version": "v1"
},
{
"created": "Wed, 27 Apr 2022 07:33:09 GMT",
"version": "v2"
}
] | 2022-04-28 | [
[
"Suenaga",
"Daiki",
""
],
[
"Araki",
"Yasufumi",
""
],
[
"Suzuki",
"Kei",
""
],
[
"Yasui",
"Shigehiro",
""
]
] | We propose a new mechanism of the heavy-quark spin polarization (HQSP) in quark matter induced by the Kondo effect under external magnetic field. The Kondo effect is caused by a condensate between a heavy and a light quark called the Kondo condensate leading to a mixing of the heavy and light quark spins. Thus the HQSP is driven through the Kondo effect from light quarks coupling with the magnetic field in quark matter. For demonstration, we employ the Nambu--Jona-Lasinio type model under a magnetic field, and investigate the HQSP within the linear response theory with vertex corrections required by the $U(1)_{\rm EM}$ electromagnetic gauge invariance. As a result, we find that the HQSP arises significantly with the appearance of the Kondo effect. Our findings are testable in future sign-problem-free lattice simulations. |
2309.01337 | Zhi-Gang Wang | Zhi-Gang Wang | Three-body strong decays of the $Y(4230)$ via the light-cone QCD sum
rules | 13 pages, 4 figures. arXiv admin note: text overlap with
arXiv:2304.14153 | Int. J. Mod. Phys. A38 (2023) 2350175 | 10.1142/S0217751X23501750 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We tentatively assign the $Y(4230)$ as the vector tetraquark state with a
relative P-wave between the scalar diquark pair, and explore the three-body
strong decays $Y(4230) \to \bar{D}^{*-}D^{*0}\pi^+$, $\bar{D}^{*-}D^0\pi^+$,
$J/\psi\pi^+\pi^- $ and $ J/\psi K^+K^-$ with the light-cone QCD sum rules by
assuming contact four-meson coupling constants. The resulting partial decay
widths are too small to account for the experimental data, and we expect those
decays take place through an intermediate meson. We can search for the
intermediate states and precisely measure the branching fractions to diagnose
the nature of the $Y$ states.
| [
{
"created": "Mon, 4 Sep 2023 03:45:35 GMT",
"version": "v1"
},
{
"created": "Wed, 22 Nov 2023 07:47:23 GMT",
"version": "v2"
}
] | 2024-02-13 | [
[
"Wang",
"Zhi-Gang",
""
]
] | We tentatively assign the $Y(4230)$ as the vector tetraquark state with a relative P-wave between the scalar diquark pair, and explore the three-body strong decays $Y(4230) \to \bar{D}^{*-}D^{*0}\pi^+$, $\bar{D}^{*-}D^0\pi^+$, $J/\psi\pi^+\pi^- $ and $ J/\psi K^+K^-$ with the light-cone QCD sum rules by assuming contact four-meson coupling constants. The resulting partial decay widths are too small to account for the experimental data, and we expect those decays take place through an intermediate meson. We can search for the intermediate states and precisely measure the branching fractions to diagnose the nature of the $Y$ states. |
hep-ph/9404285 | Martin Savage | Martin J. Savage | $\Lambda (1405)$ Contribution to Kaon-Nucleon Scattering Lengths In
Chiral Perturbation Theory | 11 pages, figure not included, uses harvmac, CMU-HEP 94-11,
NSF-ITP-94-33 | Phys.Lett.B331:411-417,1994 | 10.1016/0370-2693(94)91072-3 | null | hep-ph nucl-th | null | We examine the role of the $\Lambda(1405)$ in kaon-nucleon scattering lengths
using chiral perturbation theory. The leading nonanalytic SU(3) corrections
reduce the coupling of the $\Lambda (1405)$ to $KN$ compared to $\Sigma\pi$.
S-wave $K^-p$ scattering is the only channel significantly affected by the $
\Lambda (1405)$ pole which substantially cancels against the leading term fixed
by the vector current. This cancellation and the close proximity of the
$\Lambda (1405)$ pole makes this SU(3) correction to $a(K^-p)$ large and at
lowest order leaves the sign of $a(K^-p)$ undetermined. We extract two linear
combinations of constants appearing at higher order in the chiral expansion
from measurements of $KN$ scattering lengths. These constants are important for
the offshell behaviour of $KN$ scattering amplitudes that play a central role
in kaon condensation. The recent claims about the calculability of these
constants are discussed.
| [
{
"created": "Mon, 18 Apr 1994 21:04:24 GMT",
"version": "v1"
}
] | 2011-07-19 | [
[
"Savage",
"Martin J.",
""
]
] | We examine the role of the $\Lambda(1405)$ in kaon-nucleon scattering lengths using chiral perturbation theory. The leading nonanalytic SU(3) corrections reduce the coupling of the $\Lambda (1405)$ to $KN$ compared to $\Sigma\pi$. S-wave $K^-p$ scattering is the only channel significantly affected by the $ \Lambda (1405)$ pole which substantially cancels against the leading term fixed by the vector current. This cancellation and the close proximity of the $\Lambda (1405)$ pole makes this SU(3) correction to $a(K^-p)$ large and at lowest order leaves the sign of $a(K^-p)$ undetermined. We extract two linear combinations of constants appearing at higher order in the chiral expansion from measurements of $KN$ scattering lengths. These constants are important for the offshell behaviour of $KN$ scattering amplitudes that play a central role in kaon condensation. The recent claims about the calculability of these constants are discussed. |
hep-ph/0012181 | James Wells | James D. Wells | The role of supersymmetry phenomenology in particle physics | 11 pages, LaTeX | null | null | null | hep-ph | null | Supersymmetry phenomenology is an important component of particle physics
today. I provide a definition of supersymmetry phenomenology, outline the scope
of its activity, and argue its legitimacy. This essay derives from a
presentation given at the 2000 SLAC Summer Institute.
| [
{
"created": "Thu, 14 Dec 2000 23:10:30 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Wells",
"James D.",
""
]
] | Supersymmetry phenomenology is an important component of particle physics today. I provide a definition of supersymmetry phenomenology, outline the scope of its activity, and argue its legitimacy. This essay derives from a presentation given at the 2000 SLAC Summer Institute. |
hep-ph/0202187 | Hans-Christian Pauli | Hans-Christian Pauli (MPI Kernphysik, Heidelberg) | On flavor mixing by an effective Light-Cone QCD-Hamiltonian | LaTeX, 8 pages, 1 figure, 6 tables, 8 references. Submitted to
Nuclear Physics B (2002) | null | null | null | hep-ph | null | The $\uparrow\downarrow$-model has produced the physical masses of all
flavor-asymmetric mesons like the $\pi^\pm$ or the $\rho^\pm$. Can the same
model also account for the flavor-symmetric mesons like the $\pi^0$ or the
$\rho^0$? -- By adjusting one parameter in a $5\times5$-matrix, the
$\pi$-$\eta$ degeneracy is lifted and the $\eta-\eta'$ splitting falls into the
right ball park. The isospin triplets for pions and rhos are caused the
mass-degeneracy of the up and down quark.
| [
{
"created": "Tue, 19 Feb 2002 17:24:06 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Pauli",
"Hans-Christian",
"",
"MPI Kernphysik, Heidelberg"
]
] | The $\uparrow\downarrow$-model has produced the physical masses of all flavor-asymmetric mesons like the $\pi^\pm$ or the $\rho^\pm$. Can the same model also account for the flavor-symmetric mesons like the $\pi^0$ or the $\rho^0$? -- By adjusting one parameter in a $5\times5$-matrix, the $\pi$-$\eta$ degeneracy is lifted and the $\eta-\eta'$ splitting falls into the right ball park. The isospin triplets for pions and rhos are caused the mass-degeneracy of the up and down quark. |
hep-ph/0506289 | John M. Campbell | John Campbell and Francesco Tramontano | Next-to-leading order corrections to Wt production and decay | 31 pages, 12 figures | Nucl.Phys.B726:109-130,2005 | 10.1016/j.nuclphysb.2005.08.015 | CERN-PH-TH/2005-110, DSF-18/2005 | hep-ph | null | We present the results of a next-to-leading order calculation of Wt
production, including the decays of both the top quark and the W boson. The
effects of radiation in the decay of the top quark are also included. The
separation of diagrams which appear in the real corrections, into singly- and
doubly-resonant contributions, is performed using a b-jet veto which is
motivated by the use of the bottom quark distribution function. We find that,
for a choice of scale which is suitable for this approach, the QCD corrections
are very mild and only change the cross section by up to 10% at the LHC,
depending on the severity of the b-jet veto. When further cuts are applied,
applicable for a Higgs boson search in the H->WW channel, we find that the
radiative effects greatly decrease the number of background events expected
from this process. In addition, the shapes of relevant distributions can be
significantly changed at next-to-leading order.
| [
{
"created": "Tue, 28 Jun 2005 12:11:50 GMT",
"version": "v1"
}
] | 2009-02-05 | [
[
"Campbell",
"John",
""
],
[
"Tramontano",
"Francesco",
""
]
] | We present the results of a next-to-leading order calculation of Wt production, including the decays of both the top quark and the W boson. The effects of radiation in the decay of the top quark are also included. The separation of diagrams which appear in the real corrections, into singly- and doubly-resonant contributions, is performed using a b-jet veto which is motivated by the use of the bottom quark distribution function. We find that, for a choice of scale which is suitable for this approach, the QCD corrections are very mild and only change the cross section by up to 10% at the LHC, depending on the severity of the b-jet veto. When further cuts are applied, applicable for a Higgs boson search in the H->WW channel, we find that the radiative effects greatly decrease the number of background events expected from this process. In addition, the shapes of relevant distributions can be significantly changed at next-to-leading order. |
2201.04492 | Yan-Qing Ma | An-Ping Chen, Xiao-Bo Jin, Yan-Qing Ma, Ce Meng | Color-octet contributions for $J/\psi$ inclusive production at B
factories in soft gluon factorization | 35 pages, 5 figures, published version | JHEP03(2022)202 | 10.1007/JHEP03(2022)202 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We have studied color-octet contributions for $J/\psi$ inclusive production
at B factories, i.e., $e^+e^-\to J/\psi(^3P_J^{[8]},^1S_0^{[8]}) +
X_{\mathrm{non}-c\bar c}$, using the soft gluon factorization (SGF) approach,
in which the $J/\psi$ energy spectrum is expressed in a form of perturbatively
calculable short-distance hard parts convoluted with one-dimensional soft gluon
distributions (SGDs). The series of velocity corrections originated from
kinematic effect can be naturally resummed in this approach. Short-distance
hard parts have been calculated analytically to next-to-leading order in
$\alpha_s$. Renormalization group equations for SGDs have been derived and
solved, which resums Sudakov logarithms originated from soft gluon emissions.
Our final result gives a upper bound for color-octet matrix elements consistent
with that extracted from hadron colliders. This may relieve the well-known
universality problem in the NRQCD factorization.
As a comparison, we also analytically calculated short-distance hard parts in
the NRQCD factorization, with Sudakov logarithms resummed by using soft
collinear effective theory. The comparison shows that velocity corrections from
kinematic effect, which have been resummed in SGF, are significant for
phenomenological study. Furthermore, it is found that Sudakov logarithms
originated from soft gluon emissions are very important, while it is not the
case for Sudakov logarithms originated from jet function. Therefore, the
partial Sudakov resummation in SGF has already captured the main physics.
| [
{
"created": "Wed, 12 Jan 2022 14:43:44 GMT",
"version": "v1"
},
{
"created": "Thu, 31 Mar 2022 14:35:29 GMT",
"version": "v2"
}
] | 2022-04-01 | [
[
"Chen",
"An-Ping",
""
],
[
"Jin",
"Xiao-Bo",
""
],
[
"Ma",
"Yan-Qing",
""
],
[
"Meng",
"Ce",
""
]
] | We have studied color-octet contributions for $J/\psi$ inclusive production at B factories, i.e., $e^+e^-\to J/\psi(^3P_J^{[8]},^1S_0^{[8]}) + X_{\mathrm{non}-c\bar c}$, using the soft gluon factorization (SGF) approach, in which the $J/\psi$ energy spectrum is expressed in a form of perturbatively calculable short-distance hard parts convoluted with one-dimensional soft gluon distributions (SGDs). The series of velocity corrections originated from kinematic effect can be naturally resummed in this approach. Short-distance hard parts have been calculated analytically to next-to-leading order in $\alpha_s$. Renormalization group equations for SGDs have been derived and solved, which resums Sudakov logarithms originated from soft gluon emissions. Our final result gives a upper bound for color-octet matrix elements consistent with that extracted from hadron colliders. This may relieve the well-known universality problem in the NRQCD factorization. As a comparison, we also analytically calculated short-distance hard parts in the NRQCD factorization, with Sudakov logarithms resummed by using soft collinear effective theory. The comparison shows that velocity corrections from kinematic effect, which have been resummed in SGF, are significant for phenomenological study. Furthermore, it is found that Sudakov logarithms originated from soft gluon emissions are very important, while it is not the case for Sudakov logarithms originated from jet function. Therefore, the partial Sudakov resummation in SGF has already captured the main physics. |
hep-ph/0211395 | Gouranga C. Nayak | Gouranga C. Nayak (LANL) | Graviton and Radion Production at LHC: From pp and PbPb Collisions | 8 pages latex (double column), 7 eps figures | null | null | null | hep-ph gr-qc hep-th nucl-th | null | If the Planck scale is around a TeV in theories with large extra dimension,
then gravitons should be produced in high energy hadronic collisions at the
LHC. In this paper we compute the direct graviton production cross section in a
pp and PbPb collision at LHC at \sqrt s^{NN}= 14 TeV and 5.5 TeV respectively.
The graviton production cross section in a lead-lead collision is enhanced in
comparison to a pp collision at LHC depending upon the minimum transverse
energy of the jet E_{T,jet}^{min} above which the graviton production cross
section is computed. For two extra dimensions and above E_{T,jet}^{min} = 100,
500, 1000, 1500 GeV the ratio of graviton production cross sections in a PbPb
collision to that in a pp collision is found to be 2220, 400, 43, 2. For four
extra dimensions this ratio is found to be 470, 100, 10, 0.5. In the
Randall-Sundrum model the radion production cross section is also found to be
enhanced in a lead-lead collision over that in a pp collision at LHC. The ratio
of the radion production cross sections in a PbPb collision to that in a pp
collision at LHC is found to be 1650, 460, 180, 67, 23, 1 for radion of masses
100, 500, 1000, 1500, 2000, 3000 GeV respectively.
| [
{
"created": "Tue, 26 Nov 2002 19:55:35 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Nayak",
"Gouranga C.",
"",
"LANL"
]
] | If the Planck scale is around a TeV in theories with large extra dimension, then gravitons should be produced in high energy hadronic collisions at the LHC. In this paper we compute the direct graviton production cross section in a pp and PbPb collision at LHC at \sqrt s^{NN}= 14 TeV and 5.5 TeV respectively. The graviton production cross section in a lead-lead collision is enhanced in comparison to a pp collision at LHC depending upon the minimum transverse energy of the jet E_{T,jet}^{min} above which the graviton production cross section is computed. For two extra dimensions and above E_{T,jet}^{min} = 100, 500, 1000, 1500 GeV the ratio of graviton production cross sections in a PbPb collision to that in a pp collision is found to be 2220, 400, 43, 2. For four extra dimensions this ratio is found to be 470, 100, 10, 0.5. In the Randall-Sundrum model the radion production cross section is also found to be enhanced in a lead-lead collision over that in a pp collision at LHC. The ratio of the radion production cross sections in a PbPb collision to that in a pp collision at LHC is found to be 1650, 460, 180, 67, 23, 1 for radion of masses 100, 500, 1000, 1500, 2000, 3000 GeV respectively. |
1312.3830 | Qiang Li | Qiang Li, Qi-Shu Yan, Xiaoran Zhao | Higgs Pair Production: Improved Description by Matrix Element Matching | accepted version in Phys. Rev. D. arXiv admin note: substantial text
overlap with arXiv:1110.1728 | Phys. Rev. D 89, 033015 (2014) | 10.1103/PhysRevD.89.033015 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Higgs pair production is crucial for measuring the Higgs boson self-coupling.
The dominant channel at hadron colliders is gluon fusion via heavy-quark loops.
We present the results of a fully exclusive simulation of gluon fusion Higgs
pair production based on the matrix elements for hh + 0, 1 partons including
full heavy-quark loop dependence, matched to a parton shower. We examine and
validate this new description by comparing it with (a) Higgs Effective Theory
predictions, (b) exact hh + 0-parton sample showered by pythia, and (c) exact
hh+1-parton distributions, by looking at the most relevant kinematic
distributions, such as PTh, PThh, Mhh spectra, and jet rate as well. We find
that matched samples provide an state-of-the-art accurate exclusive description
of the final state. The relevant LHE files for Higgs pair productions at the
LHC can be accessed via http://hepfarm02.phy.pku.edu.cn/foswiki/CMS/HH, which
can be used for relevant experimental analysis.
| [
{
"created": "Fri, 13 Dec 2013 15:10:12 GMT",
"version": "v1"
},
{
"created": "Tue, 4 Feb 2014 15:46:06 GMT",
"version": "v2"
}
] | 2014-03-05 | [
[
"Li",
"Qiang",
""
],
[
"Yan",
"Qi-Shu",
""
],
[
"Zhao",
"Xiaoran",
""
]
] | Higgs pair production is crucial for measuring the Higgs boson self-coupling. The dominant channel at hadron colliders is gluon fusion via heavy-quark loops. We present the results of a fully exclusive simulation of gluon fusion Higgs pair production based on the matrix elements for hh + 0, 1 partons including full heavy-quark loop dependence, matched to a parton shower. We examine and validate this new description by comparing it with (a) Higgs Effective Theory predictions, (b) exact hh + 0-parton sample showered by pythia, and (c) exact hh+1-parton distributions, by looking at the most relevant kinematic distributions, such as PTh, PThh, Mhh spectra, and jet rate as well. We find that matched samples provide an state-of-the-art accurate exclusive description of the final state. The relevant LHE files for Higgs pair productions at the LHC can be accessed via http://hepfarm02.phy.pku.edu.cn/foswiki/CMS/HH, which can be used for relevant experimental analysis. |
hep-ph/0211103 | Abdelkader-Salim Safir | A. Salim Safir (DESY, Hamburg) | Theoretical studies of exclusive rare B decays in the Standard Model and
Supersymmetric theories | Ph.D. Thesis, 126 pages, 41 figures (requires epsfig, psfrag) | null | null | DESY-THESIS-2002-040 | hep-ph | null | We calculate the independent helicity amplitudes in the decays $B \to K^*
\ell^+ \ell^-$ and $B \to \rho \ell \nu_\ell$ in the so-called
Large-Energy-Effective-Theory (LEET). Taking into account the dominant
$O(\alpha_s)$ and SU(3) symmetry-breaking effects, we calculate various Dalitz
distributions in these decays making use of the presently available data and
decay form factors calculated in the QCD sum rule approach. Differential decay
rates in the dilepton invariant mass and the Forward-Backward asymmetry in $B
\to K^* \ell^+ \ell^-$ are worked out. We also present the decay amplitudes in
the transversity basis which has been used in the analysis of data on the
resonant decay $B \to K^* J/\psi (\to \ell^+ \ell^-)$. Measurements of the
ratios $R_i(s) \equiv d \Gamma_{H_i}(s)(B \to K^* \ell^+ \ell^-)/ d
\Gamma_{H_i}(s)(B \to \rho \ell \nu_\ell)$, involving the helicity amplitudes
$H_i(s)$, $i=0,+1, -1$, as precision tests of the standard model in
semileptonic rare B-decays are emphasized. We argue that $R_0(s)$ and
$R_{-}(s)$ can be used to determine the CKM ratio $| V_{ub}|/| V_{ts} |$ and
search for new physics, where the later is illustrated by supersymmetry.
| [
{
"created": "Thu, 7 Nov 2002 16:43:18 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Safir",
"A. Salim",
"",
"DESY, Hamburg"
]
] | We calculate the independent helicity amplitudes in the decays $B \to K^* \ell^+ \ell^-$ and $B \to \rho \ell \nu_\ell$ in the so-called Large-Energy-Effective-Theory (LEET). Taking into account the dominant $O(\alpha_s)$ and SU(3) symmetry-breaking effects, we calculate various Dalitz distributions in these decays making use of the presently available data and decay form factors calculated in the QCD sum rule approach. Differential decay rates in the dilepton invariant mass and the Forward-Backward asymmetry in $B \to K^* \ell^+ \ell^-$ are worked out. We also present the decay amplitudes in the transversity basis which has been used in the analysis of data on the resonant decay $B \to K^* J/\psi (\to \ell^+ \ell^-)$. Measurements of the ratios $R_i(s) \equiv d \Gamma_{H_i}(s)(B \to K^* \ell^+ \ell^-)/ d \Gamma_{H_i}(s)(B \to \rho \ell \nu_\ell)$, involving the helicity amplitudes $H_i(s)$, $i=0,+1, -1$, as precision tests of the standard model in semileptonic rare B-decays are emphasized. We argue that $R_0(s)$ and $R_{-}(s)$ can be used to determine the CKM ratio $| V_{ub}|/| V_{ts} |$ and search for new physics, where the later is illustrated by supersymmetry. |
0812.4392 | Helmut Eberl Dr. | E. Christova, H. Eberl, E. Ginina, W. Majerotto | CP violation in $H^\pm t$ production at the LHC | version published in PRD | Phys.Rev.D79:096005,2009 | 10.1103/PhysRevD.79.096005 | HEPHY-PUB 876/08 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study effects of CP violation in the associated production of a charged
Higgs boson and a top quark at the LHC, $pp \to tH^\pm + X$. We calculate the
CP violating asymmetry between the total cross section for $H^+$ and $H^-$
production at next-to-leading order in the MSSM, and perform a detailed
numerical analysis. In the production the asymmetry is of the order of 20%. The
asymmetry in the production and any subsequent decay of an on-shell charged
Higgs boson is to a good approximation the sum of the asymmetry in the
production and the asymmetry in the decay. We consider subsequent decays of
$H^\pm $ to $t b$, $\nu_\tau \tau^\pm$ and $W h^0$. In the case with $H^\pm \to
t b$ decay, mainly due to CP violating box graphs with gluino, the asymmetry
can go up to $\sim$ 12%.
| [
{
"created": "Tue, 23 Dec 2008 15:54:04 GMT",
"version": "v1"
},
{
"created": "Fri, 27 Feb 2009 15:04:15 GMT",
"version": "v2"
},
{
"created": "Tue, 23 Jun 2009 15:07:53 GMT",
"version": "v3"
}
] | 2009-10-29 | [
[
"Christova",
"E.",
""
],
[
"Eberl",
"H.",
""
],
[
"Ginina",
"E.",
""
],
[
"Majerotto",
"W.",
""
]
] | We study effects of CP violation in the associated production of a charged Higgs boson and a top quark at the LHC, $pp \to tH^\pm + X$. We calculate the CP violating asymmetry between the total cross section for $H^+$ and $H^-$ production at next-to-leading order in the MSSM, and perform a detailed numerical analysis. In the production the asymmetry is of the order of 20%. The asymmetry in the production and any subsequent decay of an on-shell charged Higgs boson is to a good approximation the sum of the asymmetry in the production and the asymmetry in the decay. We consider subsequent decays of $H^\pm $ to $t b$, $\nu_\tau \tau^\pm$ and $W h^0$. In the case with $H^\pm \to t b$ decay, mainly due to CP violating box graphs with gluino, the asymmetry can go up to $\sim$ 12%. |
2010.03297 | Marzia Bordone | Marzia Bordone, Oscar Cata, Thorsten Feldmann, Rusa Mandal | Constraining flavour patterns of scalar leptoquarks in the effective
field theory | 45 pages, 2 figures, 4 tables; v2 as published in JHEP | null | 10.1007/JHEP03(2021)122 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the viability of extending the Standard Model with $S_1$ and
$S_3$ scalar leptoquarks when the flavour structure is parametrized in terms of
Froggatt-Nielsen charges. In contrast to a similar analysis with a vector
leptoquark, we find essentially two solutions for the charges that fit the
experimental constraints, which are dominated by the current tensions in $B$
decays. These two scenarios differ in their estimate of the anomalous magnetic
moment of the muon, $(g-2)$, but they both predict sizeable contributions to
$\tau\to\mu\gamma$, $\bar B_s\to\tau^\pm\mu^\mp$ and $B^+\to K^+\tau^+\mu^-$
decays, whose branching ratios are close to the current experimental limits.
| [
{
"created": "Wed, 7 Oct 2020 09:21:55 GMT",
"version": "v1"
},
{
"created": "Tue, 16 Mar 2021 15:03:22 GMT",
"version": "v2"
}
] | 2021-03-17 | [
[
"Bordone",
"Marzia",
""
],
[
"Cata",
"Oscar",
""
],
[
"Feldmann",
"Thorsten",
""
],
[
"Mandal",
"Rusa",
""
]
] | We investigate the viability of extending the Standard Model with $S_1$ and $S_3$ scalar leptoquarks when the flavour structure is parametrized in terms of Froggatt-Nielsen charges. In contrast to a similar analysis with a vector leptoquark, we find essentially two solutions for the charges that fit the experimental constraints, which are dominated by the current tensions in $B$ decays. These two scenarios differ in their estimate of the anomalous magnetic moment of the muon, $(g-2)$, but they both predict sizeable contributions to $\tau\to\mu\gamma$, $\bar B_s\to\tau^\pm\mu^\mp$ and $B^+\to K^+\tau^+\mu^-$ decays, whose branching ratios are close to the current experimental limits. |
2105.03355 | Benoit Loiseau | J.-P.Dedonder, R. Kami\'nski, L. Le\'sniak, B. Loiseau | Dalitz plot studies of $D^0 \to K^0_S K^+ K^-$ decays in a factorization
approach | 50 pages, 17 figures; v2: figure 10 is now cited in the text, typos
corrected, matches the published (PRD) version | Phys. Rev. D 103, 114028 (2021) | 10.1103/PhysRevD.103.114028 | null | hep-ph hep-ex nucl-th | http://creativecommons.org/licenses/by/4.0/ | The $\textit{BABAR}$ Collaboration data of the $D^0 \to K^0_S K^+ K^-$
process are analyzed within a quasi two-body factorization framework. In
earlier studies, assuming $D^0$ transitions to two kaons and the transitions
between one kaon and two kaons to proceed through the dominant intermediate
resonances, we approximated them as being proportional to the kaon form
factors. To obtain good fits, one has to multiply the scalar-kaon form factors,
derived from unitary relativistic coupled-channel models or in a dispersion
relation approach, by phenomenological energy-dependent functions. The final
state kaon-kaon interactions in the $S$-, $P$- and $D$- waves are taken into
account. All $S$-wave channels are treated in a unitary way. The $K^+K^-$ and
$\bar K^0 K^+$ $S$-wave effective mass squared distributions, corrected for
phase space, are shown, in a model-independent manner, to be significantly
different. Then the $f_0(980)$ resonance must be included at variance with the
BABAR analysis. The best fit has 19 free parameters and indicates i) the
dominance of annihilation amplitudes, ii) a large dominance of the $f_0(980)$
meson in the near threshold $K^+K^-$ invariant mass distribution and iii) a
sizable branching fraction to the $K_S^0 \ [\rho(770)^+ + \rho(1450)^+ +
\rho(1700)^+] $ final states. An appendix provides an update of the
determination of the isoscalar-scalar meson-meson amplitudes based on an
enlarged set of data. A second appendix proposes two alternative fits based on
scalar-kaon form factors calculated from the Muskhelishvili-Omn\`es dispersion
relation approach. These fits have $\chi^2$ quite close to that of the best fit
but they show important contributions from both the $f_0$ and $a_0^0$ mesons
and a weaker role of the $\rho^+$ mesons.
| [
{
"created": "Fri, 7 May 2021 16:12:32 GMT",
"version": "v1"
},
{
"created": "Thu, 1 Jul 2021 09:03:40 GMT",
"version": "v2"
}
] | 2021-07-02 | [
[
"Dedonder",
"J. -P.",
""
],
[
"Kamiński",
"R.",
""
],
[
"Leśniak",
"L.",
""
],
[
"Loiseau",
"B.",
""
]
] | The $\textit{BABAR}$ Collaboration data of the $D^0 \to K^0_S K^+ K^-$ process are analyzed within a quasi two-body factorization framework. In earlier studies, assuming $D^0$ transitions to two kaons and the transitions between one kaon and two kaons to proceed through the dominant intermediate resonances, we approximated them as being proportional to the kaon form factors. To obtain good fits, one has to multiply the scalar-kaon form factors, derived from unitary relativistic coupled-channel models or in a dispersion relation approach, by phenomenological energy-dependent functions. The final state kaon-kaon interactions in the $S$-, $P$- and $D$- waves are taken into account. All $S$-wave channels are treated in a unitary way. The $K^+K^-$ and $\bar K^0 K^+$ $S$-wave effective mass squared distributions, corrected for phase space, are shown, in a model-independent manner, to be significantly different. Then the $f_0(980)$ resonance must be included at variance with the BABAR analysis. The best fit has 19 free parameters and indicates i) the dominance of annihilation amplitudes, ii) a large dominance of the $f_0(980)$ meson in the near threshold $K^+K^-$ invariant mass distribution and iii) a sizable branching fraction to the $K_S^0 \ [\rho(770)^+ + \rho(1450)^+ + \rho(1700)^+] $ final states. An appendix provides an update of the determination of the isoscalar-scalar meson-meson amplitudes based on an enlarged set of data. A second appendix proposes two alternative fits based on scalar-kaon form factors calculated from the Muskhelishvili-Omn\`es dispersion relation approach. These fits have $\chi^2$ quite close to that of the best fit but they show important contributions from both the $f_0$ and $a_0^0$ mesons and a weaker role of the $\rho^+$ mesons. |
1310.5758 | Jared Evans | Jared A. Evans, Yevgeny Kats, David Shih, and Matthew J. Strassler | Toward Full LHC Coverage of Natural Supersymmetry | 53 pages, 16 figures, journal version | JHEP 1407 (2014) 101 | 10.1007/JHEP07(2014)101 | RUNHETC-2013-19 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We argue that combining just a handful of searches for new physics at Run I
of the LHC is sufficient to exclude most supersymmetric extensions of the
Standard Model in which the gluino is kinematically accessible and the spectrum
is natural. Such models typically give rise to significant MET, top quarks
and/or high object multiplicity, and we show that having even one of these
signatures generally results in stringent limits. We also identify, among
models that lack these signatures, the few gaps in coverage remaining, and
propose search strategies to close these gaps. Our results are general and
independent of the details of the spectrum, assumptions about minimality,
R-parity, etc. Our analysis strategy should remain applicable when the LHC
moves to higher energy. Central to our argument are ATLAS and CMS searches for
many jets and low MET, a proposed lepton + many jets search, an ATLAS search
for 6-7 high-pT jets, and a reexamination of the control and signal regions of
the CMS black hole search.
| [
{
"created": "Mon, 21 Oct 2013 23:31:05 GMT",
"version": "v1"
},
{
"created": "Thu, 7 Aug 2014 18:32:55 GMT",
"version": "v2"
}
] | 2015-06-17 | [
[
"Evans",
"Jared A.",
""
],
[
"Kats",
"Yevgeny",
""
],
[
"Shih",
"David",
""
],
[
"Strassler",
"Matthew J.",
""
]
] | We argue that combining just a handful of searches for new physics at Run I of the LHC is sufficient to exclude most supersymmetric extensions of the Standard Model in which the gluino is kinematically accessible and the spectrum is natural. Such models typically give rise to significant MET, top quarks and/or high object multiplicity, and we show that having even one of these signatures generally results in stringent limits. We also identify, among models that lack these signatures, the few gaps in coverage remaining, and propose search strategies to close these gaps. Our results are general and independent of the details of the spectrum, assumptions about minimality, R-parity, etc. Our analysis strategy should remain applicable when the LHC moves to higher energy. Central to our argument are ATLAS and CMS searches for many jets and low MET, a proposed lepton + many jets search, an ATLAS search for 6-7 high-pT jets, and a reexamination of the control and signal regions of the CMS black hole search. |
1908.09864 | Thomas Hambye | Thomas Hambye, Michel H.G. Tytgat, J\'er\^ome Vandecasteele, Laurent
Vanderheyden | Dark matter from dark photons: a taxonomy of dark matter production | 18 pages, 14 figures | Phys. Rev. D 100, 095018 (2019) | 10.1103/PhysRevD.100.095018 | ULB-TH/19-07 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We analyse how dark matter (DM) can be produced in the early universe,
working in the framework of a hidden sector charged under a U(1)' gauge
symmetry and interacting with the Standard Model through kinetic mixing.
Depending on the masses of the dark matter particle and of the dark photon, as
well as on the hidden U(1)' gauge coupling and the kinetic mixing parameter, we
classify all the distinct regimes along which the observed dark matter relic
density can be accounted for. We find that 9 regimes are potentially operative
to produce the DM particles and this along 5 distinct dynamical mechanisms.
Among these, 4 regimes are new and correspond to regimes in which the DM
particles are produced by on-shell dark photons. One of them proceeds along a
new dynamical mechanism, which we dub sequential freeze-in. We argue that such
regimes and the associated dynamical mechanisms are characteristic of DM models
for which, on top of the Standard Model and the dark sector, there are other
massive, but relatively light particles -- akin to the dark photon -- that
interact both with the SM and the DM sectors.
| [
{
"created": "Mon, 26 Aug 2019 18:12:31 GMT",
"version": "v1"
}
] | 2019-11-27 | [
[
"Hambye",
"Thomas",
""
],
[
"Tytgat",
"Michel H. G.",
""
],
[
"Vandecasteele",
"Jérôme",
""
],
[
"Vanderheyden",
"Laurent",
""
]
] | We analyse how dark matter (DM) can be produced in the early universe, working in the framework of a hidden sector charged under a U(1)' gauge symmetry and interacting with the Standard Model through kinetic mixing. Depending on the masses of the dark matter particle and of the dark photon, as well as on the hidden U(1)' gauge coupling and the kinetic mixing parameter, we classify all the distinct regimes along which the observed dark matter relic density can be accounted for. We find that 9 regimes are potentially operative to produce the DM particles and this along 5 distinct dynamical mechanisms. Among these, 4 regimes are new and correspond to regimes in which the DM particles are produced by on-shell dark photons. One of them proceeds along a new dynamical mechanism, which we dub sequential freeze-in. We argue that such regimes and the associated dynamical mechanisms are characteristic of DM models for which, on top of the Standard Model and the dark sector, there are other massive, but relatively light particles -- akin to the dark photon -- that interact both with the SM and the DM sectors. |
2111.14760 | Lingxiao Wang | Lingxiao Wang, Shuzhe Shi, Kai Zhou | Reconstructing spectral functions via automatic differentiation | 9 pages, 10 figures. Updated to the published version | Phys.Rev.D 106 (2022) 5, L051502 | 10.1103/PhysRevD.106.L051502 | null | hep-ph cs.LG hep-lat | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Reconstructing spectral functions from Euclidean Green's functions is an
important inverse problem in many-body physics. However, the inversion is
proved to be ill-posed in the realistic systems with noisy Green's functions.
In this Letter, we propose an automatic differentiation(AD) framework as a
generic tool for the spectral reconstruction from propagator observable.
Exploiting the neural networks' regularization as a non-local smoothness
regulator of the spectral function, we represent spectral functions by neural
networks and use the propagator's reconstruction error to optimize the network
parameters unsupervisedly. In the training process, except for the
positive-definite form for the spectral function, there are no other explicit
physical priors embedded into the neural networks. The reconstruction
performance is assessed through relative entropy and mean square error for two
different network representations. Compared to the maximum entropy method, the
AD framework achieves better performance in the large-noise situation. It is
noted that the freedom of introducing non-local regularization is an inherent
advantage of the present framework and may lead to substantial improvements in
solving inverse problems.
| [
{
"created": "Mon, 29 Nov 2021 18:09:49 GMT",
"version": "v1"
},
{
"created": "Sat, 1 Jan 2022 23:21:17 GMT",
"version": "v2"
},
{
"created": "Tue, 20 Sep 2022 18:59:18 GMT",
"version": "v3"
}
] | 2022-09-22 | [
[
"Wang",
"Lingxiao",
""
],
[
"Shi",
"Shuzhe",
""
],
[
"Zhou",
"Kai",
""
]
] | Reconstructing spectral functions from Euclidean Green's functions is an important inverse problem in many-body physics. However, the inversion is proved to be ill-posed in the realistic systems with noisy Green's functions. In this Letter, we propose an automatic differentiation(AD) framework as a generic tool for the spectral reconstruction from propagator observable. Exploiting the neural networks' regularization as a non-local smoothness regulator of the spectral function, we represent spectral functions by neural networks and use the propagator's reconstruction error to optimize the network parameters unsupervisedly. In the training process, except for the positive-definite form for the spectral function, there are no other explicit physical priors embedded into the neural networks. The reconstruction performance is assessed through relative entropy and mean square error for two different network representations. Compared to the maximum entropy method, the AD framework achieves better performance in the large-noise situation. It is noted that the freedom of introducing non-local regularization is an inherent advantage of the present framework and may lead to substantial improvements in solving inverse problems. |
1112.1685 | Francisco Larios | F. Larios and M. A. Perez | New Physics effects on hadronic decay asymmetries of the Top quark | null | null | 10.1103/PhysRevD.85.017503 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study some New Physics effects on the hadronic decays of the Top quark,
like t-> b bbar c, and on a forward-backward-like CP even asymmetry A_t
constructed in such a way that it is zero in the SM. We find that an anomalous
right-handed contribution of the effective tbW vertex may induce an asymmetry
A_t of the order of 20 %. A light W' boson with pure right handed couplings
tdW' may induce an asymmetry A_t of the same order of magnitude.
| [
{
"created": "Wed, 7 Dec 2011 20:43:37 GMT",
"version": "v1"
}
] | 2013-05-30 | [
[
"Larios",
"F.",
""
],
[
"Perez",
"M. A.",
""
]
] | We study some New Physics effects on the hadronic decays of the Top quark, like t-> b bbar c, and on a forward-backward-like CP even asymmetry A_t constructed in such a way that it is zero in the SM. We find that an anomalous right-handed contribution of the effective tbW vertex may induce an asymmetry A_t of the order of 20 %. A light W' boson with pure right handed couplings tdW' may induce an asymmetry A_t of the same order of magnitude. |
1910.10166 | Zhong-Bo Kang | Zhong-Bo Kang, Xiaohui Liu | Power Counting the Small-$x$ Observables | 5 pages, 2 figures, statements clarified and references added | null | null | null | hep-ph hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We emphasize the importance of applying power counting to the small-$x$
observables, which introduces novel soft contributions usually missing and
allows for a unified treatment of the Balitsky-Kovchegov (BK) evolution and
various Sudakov logarithms. We use $pA \to h(p_{h\perp})X$ at forward rapidity
to highlight how the power counting yields a partonic cross section with
collinear and soft sectors. We show how the kinematic constraints can be
obtained in the soft sector without violating the power counting. We further
show how one can resum the threshold Sudakov logarithms systematically to all
orders in a re-factorized framework with additional collinear-soft
contributions. Direct applications to other small-$x$ processes involving heavy
particles, jet (sub-)observables and EIC physics are straightforward.
| [
{
"created": "Tue, 22 Oct 2019 18:00:08 GMT",
"version": "v1"
},
{
"created": "Mon, 28 Oct 2019 15:48:06 GMT",
"version": "v2"
}
] | 2019-10-29 | [
[
"Kang",
"Zhong-Bo",
""
],
[
"Liu",
"Xiaohui",
""
]
] | We emphasize the importance of applying power counting to the small-$x$ observables, which introduces novel soft contributions usually missing and allows for a unified treatment of the Balitsky-Kovchegov (BK) evolution and various Sudakov logarithms. We use $pA \to h(p_{h\perp})X$ at forward rapidity to highlight how the power counting yields a partonic cross section with collinear and soft sectors. We show how the kinematic constraints can be obtained in the soft sector without violating the power counting. We further show how one can resum the threshold Sudakov logarithms systematically to all orders in a re-factorized framework with additional collinear-soft contributions. Direct applications to other small-$x$ processes involving heavy particles, jet (sub-)observables and EIC physics are straightforward. |
0808.0702 | Thomas Dent | Thomas Dent, Steffen Stern and Christof Wetterich | Unifying cosmological and recent time variations of fundamental
couplings | Formatting changes and minor typos, equivalent to published version.
35 pages (11pt article format), 8 figures | Phys.Rev.D78:103518,2008 | 10.1103/PhysRevD.78.103518 | HD-THEP-08-18 | hep-ph astro-ph gr-qc | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A number of positive and null results on the time variation of fundamental
constants have been reported. It is difficult to judge whether or not these
claims are mutually consistent, since the observable quantities depend on
several parameters, namely the coupling strengths and masses of particles. The
evolution of these coupling-parameters over cosmological history is also a
priori unknown. A direct comparison requires a relation between the couplings.
We explore several distinct scenarios based on unification of gauge couplings,
providing a representative (though not exhaustive) sample of such relations.
For each scenario we obtain a characteristic time dependence and discuss
whether a monotonic time evolution is allowed. For all scenarios, some
contradictions between different observations appear. We show how a clear
observational determination of non-zero variations would test the dominant
mechanism of varying couplings within unified theories.
| [
{
"created": "Tue, 5 Aug 2008 18:30:18 GMT",
"version": "v1"
},
{
"created": "Tue, 25 Nov 2008 20:07:54 GMT",
"version": "v2"
}
] | 2009-02-23 | [
[
"Dent",
"Thomas",
""
],
[
"Stern",
"Steffen",
""
],
[
"Wetterich",
"Christof",
""
]
] | A number of positive and null results on the time variation of fundamental constants have been reported. It is difficult to judge whether or not these claims are mutually consistent, since the observable quantities depend on several parameters, namely the coupling strengths and masses of particles. The evolution of these coupling-parameters over cosmological history is also a priori unknown. A direct comparison requires a relation between the couplings. We explore several distinct scenarios based on unification of gauge couplings, providing a representative (though not exhaustive) sample of such relations. For each scenario we obtain a characteristic time dependence and discuss whether a monotonic time evolution is allowed. For all scenarios, some contradictions between different observations appear. We show how a clear observational determination of non-zero variations would test the dominant mechanism of varying couplings within unified theories. |
hep-ph/9509315 | null | Ion I. Cot\u{a}escu (The West University of Timi\c{s}oara,
Timi\c{s}oara, Romania) | $SU(n)\otimes U(1)_c$ gauge models with spontaneous symmetry breaking | 41 pages, REVTeX | Int.J.Mod.Phys. A12 (1997) 1483-1510 | 10.1142/S0217751X97001067 | UTFT-S-1 | hep-ph | null | A possible generalization of the technique of the standard model to
$SU(n)\otimes U(1)$ gauge models is proposed. A special Higgs mechanism and a
new kind of Yukawa couplings in unitary gauge are introduced. These allow us to
obtain a general method of deriving boson mass spectrum and coupling
coefficients which will be used to find an exact solution of the Pisano-Pleitez
three-generation $SU(3)\otimes U(1)$ model. A new anomaly-free one-generation
model is briefly discussed.
| [
{
"created": "Fri, 15 Sep 1995 14:19:03 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Cotăescu",
"Ion I.",
"",
"The West University of Timişoara,\n Timişoara, Romania"
]
] | A possible generalization of the technique of the standard model to $SU(n)\otimes U(1)$ gauge models is proposed. A special Higgs mechanism and a new kind of Yukawa couplings in unitary gauge are introduced. These allow us to obtain a general method of deriving boson mass spectrum and coupling coefficients which will be used to find an exact solution of the Pisano-Pleitez three-generation $SU(3)\otimes U(1)$ model. A new anomaly-free one-generation model is briefly discussed. |
1608.07339 | Bowen Xiao | A. H. Mueller, Bin Wu, Bo-Wen Xiao, Feng Yuan | Medium Induced Transverse Momentum Broadening in Hard Processes | 16 pages, 8 figures; v2, minor revision | Phys. Rev. D 95, 034007 (2017) | 10.1103/PhysRevD.95.034007 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Using deep inelastic scattering on a large nucleus as an example, we consider
the transverse momentum broadening of partons in hard processes in the presence
of medium. We find that one can factorize the vacuum radiation contribution and
medium related $P_T$ broadening effects into the Sudakov factor and medium
dependent distributions, respectively. Our derivations can be generalized to
other hard processes, such as dijet productions, which can be used as a probe
to measure the medium $P_T$ broadening effects in heavy ion collisions when
Sudakov effects are not overwhelming.
| [
{
"created": "Thu, 25 Aug 2016 23:48:57 GMT",
"version": "v1"
},
{
"created": "Wed, 14 Sep 2016 18:50:53 GMT",
"version": "v2"
}
] | 2017-02-15 | [
[
"Mueller",
"A. H.",
""
],
[
"Wu",
"Bin",
""
],
[
"Xiao",
"Bo-Wen",
""
],
[
"Yuan",
"Feng",
""
]
] | Using deep inelastic scattering on a large nucleus as an example, we consider the transverse momentum broadening of partons in hard processes in the presence of medium. We find that one can factorize the vacuum radiation contribution and medium related $P_T$ broadening effects into the Sudakov factor and medium dependent distributions, respectively. Our derivations can be generalized to other hard processes, such as dijet productions, which can be used as a probe to measure the medium $P_T$ broadening effects in heavy ion collisions when Sudakov effects are not overwhelming. |
1801.10161 | Yue Zhao | Aaron Pierce, Keith Riles, Yue Zhao | Searching for Dark Photon Dark Matter with Gravitational Wave Detectors | 6 pages, 2 figures | Phys. Rev. Lett. 121, 061102 (2018) | 10.1103/PhysRevLett.121.061102 | LCTP-18-04 | hep-ph astro-ph.HE gr-qc | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | If dark matter stems from the background of a very light gauge boson, this
gauge boson could exert forces on test masses in gravitational wave detectors,
resulting in displacements with a characteristic frequency set by the gauge
boson mass. We outline a novel search strategy to hunt for such dark matter,
and show that both ground-based and future space-based gravitational wave
detectors have the capability to make a 5$\sigma$ discovery in unexplored
parameter regimes.
| [
{
"created": "Tue, 30 Jan 2018 19:00:01 GMT",
"version": "v1"
}
] | 2018-08-15 | [
[
"Pierce",
"Aaron",
""
],
[
"Riles",
"Keith",
""
],
[
"Zhao",
"Yue",
""
]
] | If dark matter stems from the background of a very light gauge boson, this gauge boson could exert forces on test masses in gravitational wave detectors, resulting in displacements with a characteristic frequency set by the gauge boson mass. We outline a novel search strategy to hunt for such dark matter, and show that both ground-based and future space-based gravitational wave detectors have the capability to make a 5$\sigma$ discovery in unexplored parameter regimes. |
0804.0177 | Ingo Augustin | I. Augustin, H.H. Gutbrod, D. Kraemer, K. Langanke, H. Stoecker | New Physics at the International Facility for Antiproton and Ion
Research (FAIR) Next to GSI | 7 pages, 1 figure. Invited Talk presented at the "Fourth
International Conference on Fission and Properties of Neutron-Rich nuclei",
held at Sanibel Island, Florida, November 11-17, 2007 | null | 10.1142/9789812833433_0016 | null | hep-ph nucl-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The project of the international Facility for Antiproton and Ion Research
(FAIR), co-located to the GSI facility in Darmstadt, has been officially
started on November 7, 2007. The current plans of the facility and the planned
research program will be described. An investment of about 1 billion euro will
permit new physics programs in the areas of low and medium energy antiproton
research, heavy ion physics complementary to LHC, as well as in nuclear
structure and astrophysics. The facility will comprise about a dozen
accelerators and storage rings, which will enable simultaneous operations of up
to four different beams.
| [
{
"created": "Tue, 1 Apr 2008 13:48:41 GMT",
"version": "v1"
}
] | 2017-08-23 | [
[
"Augustin",
"I.",
""
],
[
"Gutbrod",
"H. H.",
""
],
[
"Kraemer",
"D.",
""
],
[
"Langanke",
"K.",
""
],
[
"Stoecker",
"H.",
""
]
] | The project of the international Facility for Antiproton and Ion Research (FAIR), co-located to the GSI facility in Darmstadt, has been officially started on November 7, 2007. The current plans of the facility and the planned research program will be described. An investment of about 1 billion euro will permit new physics programs in the areas of low and medium energy antiproton research, heavy ion physics complementary to LHC, as well as in nuclear structure and astrophysics. The facility will comprise about a dozen accelerators and storage rings, which will enable simultaneous operations of up to four different beams. |
1607.08614 | Dorival Goncalves | Dorival Goncalves, David Lopez-Val | Boosting to identify: pseudoscalar searches with di-leptonic tops | 10 pages, 7 figures, 4 tables | Phys. Rev. D 94, 095005 (2016) | 10.1103/PhysRevD.94.095005 | IPPP/16/76, DCPT/16/152 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The quest for new heavy states is a critical component of the LHC physics
program. In this letter, we study the search for pseudoscalar bosons produced
in association with a $t\bar{t}$ pair. We consider the final state $t\bar{t} A
\to t\bar{t} b\bar{b}$ with di-leptonic top pair signature, and reconstruct the
boosted $A \to b\bar{b}$ candidate with jet substructure techniques, achieving
a remarkable sensitivity over a broad range of pseudoscalar masses and Yukawa
couplings. We apply this strategy to a Type-I Two-Higgs-Doublet Model,
demonstrating its ability to probe a realistic, UV-complete extended Higgs
sector. In particular, we find that the $13~TeV$ LHC with $300~fb^{-1}$ of data
can constrain the region $\tan\beta>1.5$ at 95$\%$ CL for a light pseudoscalar
with $m_A = 50$ GeV. Moreover, the whole mass range $20~GeV<m_A<210~GeV$ can be
ruled out for $\tan\beta \leq 1$. Finally, we show that it is also possible to
directly probe the CP-structure of the heavy scalar, and hence to distinguish a
CP-odd (A) from a CP-even (H) 2HDM resonance.
| [
{
"created": "Thu, 28 Jul 2016 20:00:02 GMT",
"version": "v1"
}
] | 2016-11-09 | [
[
"Goncalves",
"Dorival",
""
],
[
"Lopez-Val",
"David",
""
]
] | The quest for new heavy states is a critical component of the LHC physics program. In this letter, we study the search for pseudoscalar bosons produced in association with a $t\bar{t}$ pair. We consider the final state $t\bar{t} A \to t\bar{t} b\bar{b}$ with di-leptonic top pair signature, and reconstruct the boosted $A \to b\bar{b}$ candidate with jet substructure techniques, achieving a remarkable sensitivity over a broad range of pseudoscalar masses and Yukawa couplings. We apply this strategy to a Type-I Two-Higgs-Doublet Model, demonstrating its ability to probe a realistic, UV-complete extended Higgs sector. In particular, we find that the $13~TeV$ LHC with $300~fb^{-1}$ of data can constrain the region $\tan\beta>1.5$ at 95$\%$ CL for a light pseudoscalar with $m_A = 50$ GeV. Moreover, the whole mass range $20~GeV<m_A<210~GeV$ can be ruled out for $\tan\beta \leq 1$. Finally, we show that it is also possible to directly probe the CP-structure of the heavy scalar, and hence to distinguish a CP-odd (A) from a CP-even (H) 2HDM resonance. |
hep-ph/0008169 | Ted Barnes | T.Barnes (1-4) ((1) Physics Division ORNL, (2) Department of Physics
and Astronomy, University of Tennessee, (3) ITKP, University of Bonn, (4)
IKP, Forschungszentrum Juelich) | MESON2000 Conference Summary | 11 pages, 3 figures, uses appolb.cps and epsfig. MESON2000 Conference
Summary Talk | Acta Phys.Polon. B31 (2000) 2745-2754 | null | null | hep-ph nucl-th | null | This short contribution is a {\it lite} MESON2000 conference summary. As
appropriate for the 600th anniversary of the Jagellonian University, it begins
with a brief summary of the last 600 years of European history and its place in
hadron physics. Next a ``physicist chirality'' order parameter PC is
introduced. When applied to MESON2000 plenary speakers this order parameter
illustrates the separation of hadron physicists into disjoint communities. The
individual plenary talks in MESON2000 are next sorted according to the
subconference associated with each of the 36 plenary speakers. Finally, I
conclude with a previously unreported Feynman story regarding the use of models
in hadron physics.
| [
{
"created": "Wed, 16 Aug 2000 16:02:28 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Barnes",
"T.",
"",
"1-4"
]
] | This short contribution is a {\it lite} MESON2000 conference summary. As appropriate for the 600th anniversary of the Jagellonian University, it begins with a brief summary of the last 600 years of European history and its place in hadron physics. Next a ``physicist chirality'' order parameter PC is introduced. When applied to MESON2000 plenary speakers this order parameter illustrates the separation of hadron physicists into disjoint communities. The individual plenary talks in MESON2000 are next sorted according to the subconference associated with each of the 36 plenary speakers. Finally, I conclude with a previously unreported Feynman story regarding the use of models in hadron physics. |
2108.10730 | Paul Frampton | Paul H. Frampton | Additional Baryons and Mesons | 11 pages LaTeX | null | 10.1142/S0217732321501790 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | In a particle theory model whose most readily discovered new particle is the
$\sim 1$TeV bilepton resonance in same-sign leptons, currently being sought at
CERN's LHC, there exist three quarks ${\cal D, S, T}$ which will be bound by
QCD into baryons and mesons. We consider the decays of these additional baryons
and mesons whose detailed experimental study will be beyond the reach of the 14
TeV CERN collider and accessible only at an O(100 TeV) collider.
| [
{
"created": "Tue, 17 Aug 2021 20:05:39 GMT",
"version": "v1"
}
] | 2021-09-06 | [
[
"Frampton",
"Paul H.",
""
]
] | In a particle theory model whose most readily discovered new particle is the $\sim 1$TeV bilepton resonance in same-sign leptons, currently being sought at CERN's LHC, there exist three quarks ${\cal D, S, T}$ which will be bound by QCD into baryons and mesons. We consider the decays of these additional baryons and mesons whose detailed experimental study will be beyond the reach of the 14 TeV CERN collider and accessible only at an O(100 TeV) collider. |
hep-ph/0412184 | Kaminski | M. Gozdz, W. A. Kaminski | Localization on Fat Branes as the Source of Neutrino Mixing | null | Int.J.Mod.Phys. E14 (2005) 471-476 | 10.1142/S0218301305003296 | null | hep-ph | null | The localization of fermions in extra dimensions, proposed by Arkani-Hamed
and Schmaltz, is discussed as the source of the phenomenon of particle mixing.
We work out the example of neutrinos in detail.
| [
{
"created": "Tue, 14 Dec 2004 14:31:04 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Gozdz",
"M.",
""
],
[
"Kaminski",
"W. A.",
""
]
] | The localization of fermions in extra dimensions, proposed by Arkani-Hamed and Schmaltz, is discussed as the source of the phenomenon of particle mixing. We work out the example of neutrinos in detail. |
hep-ph/9903297 | Edward Shuryak | E.V.Shuryak | New phases of QCD, the tricritical point, and RHIC as a ``nutcracker'' | Talk at 15-th Winter School on Nuclear Dynamics, Parkcity Utah,
Jan.99 | null | null | null | hep-ph | null | Because too many interesting things are going on now, I have tried to squeeze
three different subjects into one talk. The first is a brief summary of the
color super-conductivity. During the last year we learned that
instanton-induced forces can not only break chiral symmetry in the QCD vacuum,
but also create correlated scalar diquarks and form new phases,some similar to
the Higgs phase of the Standard model. The second issue I discuss is the
remnant of the so called $tricritical$ point, which in QCD with physical masses
is the endpoint of the first order transition. I will argue that exchange of
sigmas (which are massless at this point even with quark masses included)
create interesting event-by-event fluctuations, which can be used to locate it.
Finally I describe first results on $flow$ calculations for non-central
collisions at RHIC. It was found that it is extremely sensitive to Equation of
State (EOS). Furthermore, the unusual ``nutcracker'' picture emerges for
lattice-motivated EOS, which is formation of two $shells$ which are physically
separated $before$ the freeze-out.
| [
{
"created": "Tue, 9 Mar 1999 14:56:25 GMT",
"version": "v1"
}
] | 2016-09-06 | [
[
"Shuryak",
"E. V.",
""
]
] | Because too many interesting things are going on now, I have tried to squeeze three different subjects into one talk. The first is a brief summary of the color super-conductivity. During the last year we learned that instanton-induced forces can not only break chiral symmetry in the QCD vacuum, but also create correlated scalar diquarks and form new phases,some similar to the Higgs phase of the Standard model. The second issue I discuss is the remnant of the so called $tricritical$ point, which in QCD with physical masses is the endpoint of the first order transition. I will argue that exchange of sigmas (which are massless at this point even with quark masses included) create interesting event-by-event fluctuations, which can be used to locate it. Finally I describe first results on $flow$ calculations for non-central collisions at RHIC. It was found that it is extremely sensitive to Equation of State (EOS). Furthermore, the unusual ``nutcracker'' picture emerges for lattice-motivated EOS, which is formation of two $shells$ which are physically separated $before$ the freeze-out. |
1103.2616 | Yoni BenTov | Yoni BenTov and A. Zee | Neutrino Mass Matrices with $M_{ee} = 0$ | 23 pages, 26 figures. v2: Added references | null | 10.1103/PhysRevD.84.073012 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Motivated by the possibility that the amplitude for neutrinoless double beta
decay may be much smaller than the planned sensitivity of future experiments,
we study ansatze for the neutrino mass matrix with $M_{ee} = 0$. For the case
in which CP is conserved, we consider two classes of real-valued mass matrices:
"Class I" defined by $|M_{e\mu}| = |M_{e\tau}|$, and "Class II" defined by
$|M_{\mu\mu}| = |M_{\tau\tau}|$. The important phenomenological distinction
between the two is that Class I permits only "small" values of $V_{e3}$ up to
$\sim 0.03$, while Class II admits "large" values of $V_{e3}$ up to its
empirical upper limit of 0.22. Then we introduce CP-violating complex phases
into the mass matrix. We show that it is possible to have tribimaximal mixing
with $M_{ee} = 0$ and $|M_{\mu\tau}| = |M_{\mu\mu}| = |M_{\tau\tau}|$ if the
Majorana phase angles are $\pm\pi/4$. Alternatively, for smaller values of
$|M_{\mu\tau}| = |M_{\mu\mu}| = |M_{\tau\tau}|$ it is possible to obtain
$|V_{e3}| \sim 0.2$ and generate relatively large CP-violating amplitudes. To
eliminate phase redundancy, we emphasize rephasing any mass matrix with $M_{ee}
= 0$ into a standard form with two complex phases. The discussion alternates
between analytical and numerical but remains purely phenomenological, without
any attempt to derive mass matrices from a fundamental theory.
| [
{
"created": "Mon, 14 Mar 2011 10:00:56 GMT",
"version": "v1"
},
{
"created": "Wed, 23 Mar 2011 14:59:17 GMT",
"version": "v2"
}
] | 2013-01-15 | [
[
"BenTov",
"Yoni",
""
],
[
"Zee",
"A.",
""
]
] | Motivated by the possibility that the amplitude for neutrinoless double beta decay may be much smaller than the planned sensitivity of future experiments, we study ansatze for the neutrino mass matrix with $M_{ee} = 0$. For the case in which CP is conserved, we consider two classes of real-valued mass matrices: "Class I" defined by $|M_{e\mu}| = |M_{e\tau}|$, and "Class II" defined by $|M_{\mu\mu}| = |M_{\tau\tau}|$. The important phenomenological distinction between the two is that Class I permits only "small" values of $V_{e3}$ up to $\sim 0.03$, while Class II admits "large" values of $V_{e3}$ up to its empirical upper limit of 0.22. Then we introduce CP-violating complex phases into the mass matrix. We show that it is possible to have tribimaximal mixing with $M_{ee} = 0$ and $|M_{\mu\tau}| = |M_{\mu\mu}| = |M_{\tau\tau}|$ if the Majorana phase angles are $\pm\pi/4$. Alternatively, for smaller values of $|M_{\mu\tau}| = |M_{\mu\mu}| = |M_{\tau\tau}|$ it is possible to obtain $|V_{e3}| \sim 0.2$ and generate relatively large CP-violating amplitudes. To eliminate phase redundancy, we emphasize rephasing any mass matrix with $M_{ee} = 0$ into a standard form with two complex phases. The discussion alternates between analytical and numerical but remains purely phenomenological, without any attempt to derive mass matrices from a fundamental theory. |
0706.3717 | Igor Ivanov | I. P. Ivanov, S. Pacetti | Corrections to the generalized vector dominance due to diffractive rho_3
production | 12 pages, 2 figures | Eur.Phys.J.C53:559-566,2008 | 10.1140/epjc/s10052-007-0488-z | null | hep-ph hep-ex | null | The idea of the vector dominance is still in use in various analyses of
experimental data of photon-hadron reactions. It makes sense, therefore, to
recast results of microscopic calculations of such reactions in this language.
Here we present the diffractive DIS $\rho_3$ production as a specific
correction to the generalized vector dominance. We perform a coupled channel
analysis of spin-orbital excitations in diffractive photoproduction and
reiterate the point that rho_3 in diffractive DIS will be sensitive to a novel
aspect of diffraction.
| [
{
"created": "Mon, 25 Jun 2007 21:46:54 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Ivanov",
"I. P.",
""
],
[
"Pacetti",
"S.",
""
]
] | The idea of the vector dominance is still in use in various analyses of experimental data of photon-hadron reactions. It makes sense, therefore, to recast results of microscopic calculations of such reactions in this language. Here we present the diffractive DIS $\rho_3$ production as a specific correction to the generalized vector dominance. We perform a coupled channel analysis of spin-orbital excitations in diffractive photoproduction and reiterate the point that rho_3 in diffractive DIS will be sensitive to a novel aspect of diffraction. |
hep-ph/9801246 | Pran Nath | R. Arnowitt and Pran Nath | Limits on SUSY particle Spectra from Proton Stability and Dark Matter
Constraints | 13 pages including 5 figures | Phys.Lett.B437:344-350,1998 | 10.1016/S0370-2693(98)00931-9 | null | hep-ph hep-ex | null | It is shown that the combined constraints on the amount of cold dark matter
and of proton stability produce a stringent upper limit on the gluino mass
$m_{\tilde g}$ (and hence on the lightest neutralino mass $m_{\chi_1^0}\simeq
m_{\tilde g}/7$) for a large class of gravity mediated supergravity unified
models. One finds that for the minimal SU(5) model current data (Kamiokande)
restricts $m_{\tilde g}\leq 400$ GeV for a scalar soft breaking mass $m_0\leq
1$ TeV. Expected future data from Super Kamionkande and ICARUS will be
sensitive to the entire range of gluino mass for $m_0\leq 1$ TeV, and be able
to exclude the region $m_{\tilde g}\geq 500$ GeV for $m_0\leq 5$ TeV. Effects
of quark mass textures are studied and one finds that the bound $m_{\tilde
g}\leq 500$ GeV holds when the experimental proton lifetime for the $p\to \bar
\nu K^+$ mode becomes $\geq 5\times 10^{32}$ yr.Implications of these results
for a test of these models at the Tevatron and at the LHC are discussed. The
effects of non-universal soft breaking in the Higgs and the third generation
squark sectors are also examined, and it is found that the proton lifetime is
sensitive to these non-universal effects. The current data already eliminates
some regions of non-universalities. The constraints of proton stability on the
direct detection of dark matter are seen to reduce the maximum event rates by
as much as a factor of $10^3$.
| [
{
"created": "Thu, 8 Jan 1998 20:14:14 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Arnowitt",
"R.",
""
],
[
"Nath",
"Pran",
""
]
] | It is shown that the combined constraints on the amount of cold dark matter and of proton stability produce a stringent upper limit on the gluino mass $m_{\tilde g}$ (and hence on the lightest neutralino mass $m_{\chi_1^0}\simeq m_{\tilde g}/7$) for a large class of gravity mediated supergravity unified models. One finds that for the minimal SU(5) model current data (Kamiokande) restricts $m_{\tilde g}\leq 400$ GeV for a scalar soft breaking mass $m_0\leq 1$ TeV. Expected future data from Super Kamionkande and ICARUS will be sensitive to the entire range of gluino mass for $m_0\leq 1$ TeV, and be able to exclude the region $m_{\tilde g}\geq 500$ GeV for $m_0\leq 5$ TeV. Effects of quark mass textures are studied and one finds that the bound $m_{\tilde g}\leq 500$ GeV holds when the experimental proton lifetime for the $p\to \bar \nu K^+$ mode becomes $\geq 5\times 10^{32}$ yr.Implications of these results for a test of these models at the Tevatron and at the LHC are discussed. The effects of non-universal soft breaking in the Higgs and the third generation squark sectors are also examined, and it is found that the proton lifetime is sensitive to these non-universal effects. The current data already eliminates some regions of non-universalities. The constraints of proton stability on the direct detection of dark matter are seen to reduce the maximum event rates by as much as a factor of $10^3$. |
hep-ph/0506167 | Ismail Turan | Shaouly Bar-Shalom (1), Gad Eilam (1,2), Mariana Frank (3) and Ismail
Turan (3,4) ((1)TECHNION,(2)Univ. of Wisconsin, (3)Concordia Univ.,
(4)William and Mary) | Width Effects on Near Threshold Decays of the Top Quark t-> cWW,cZZ and
of Neutral Higgs Bosons | 18 pages, 6 figures, uses axodraw.sty, minor correction in few
sentences, one equatin and 3 references added. To be published in Phys.Rev.D | Phys.Rev. D72 (2005) 055018 | 10.1103/PhysRevD.72.055018 | MADPH-05-1425, CUMQ/HEP-134, WM-05-108 | hep-ph | null | The nonzero widths of heavy particles become significant when they appear in
the final state of any decay occurring just around its kinematical threshold.
To take into account such effects, a procedure, called the convolution method,
was proposed by Altarelli, Conti and Lubicz. We expand their study which
included only threshold effects for t-> bWZ in the standard model. We discuss
finite width effects in the three body decays t-> cWW,cZZ and A^0(h^0)->tbW in
the type III version of a two Higgs doublet model. In particular, we find a
substantial enhancement in the decay t->cZZ, which brings its branching ratio
to BR(t->cZZ)~10^-3, and in the decay A^0->tbW, which, unlike the h^0 case,
becomes competitive with the A^0 two-body decay modes.
| [
{
"created": "Thu, 16 Jun 2005 19:41:54 GMT",
"version": "v1"
},
{
"created": "Tue, 20 Sep 2005 23:49:47 GMT",
"version": "v2"
}
] | 2009-11-11 | [
[
"Bar-Shalom",
"Shaouly",
""
],
[
"Eilam",
"Gad",
""
],
[
"Frank",
"Mariana",
""
],
[
"Turan",
"Ismail",
""
]
] | The nonzero widths of heavy particles become significant when they appear in the final state of any decay occurring just around its kinematical threshold. To take into account such effects, a procedure, called the convolution method, was proposed by Altarelli, Conti and Lubicz. We expand their study which included only threshold effects for t-> bWZ in the standard model. We discuss finite width effects in the three body decays t-> cWW,cZZ and A^0(h^0)->tbW in the type III version of a two Higgs doublet model. In particular, we find a substantial enhancement in the decay t->cZZ, which brings its branching ratio to BR(t->cZZ)~10^-3, and in the decay A^0->tbW, which, unlike the h^0 case, becomes competitive with the A^0 two-body decay modes. |
1109.2554 | Michio Hashimoto | Michio Hashimoto | A note on the coupling of the techni-dilaton to the weak bosons | 3 pages, 2 figures; minor changes, a reference added, to appear in
PRD | null | 10.1103/PhysRevD.84.111901 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this note, we study the coupling of the techni-dilaton to the weak bosons.
We consider two cases: (1) The dilaton directly couples to the weak bosons
similarly to the SM. (2) The coupling in question is effectively induced only
through the techni-fermion loops. In both cases, we find that the coupling is
essentially determined by the mass-squared of the weak bosons over the dilaton
decay constant.
| [
{
"created": "Mon, 12 Sep 2011 18:13:32 GMT",
"version": "v1"
},
{
"created": "Thu, 15 Sep 2011 10:33:30 GMT",
"version": "v2"
},
{
"created": "Sun, 11 Dec 2011 10:07:50 GMT",
"version": "v3"
}
] | 2013-05-29 | [
[
"Hashimoto",
"Michio",
""
]
] | In this note, we study the coupling of the techni-dilaton to the weak bosons. We consider two cases: (1) The dilaton directly couples to the weak bosons similarly to the SM. (2) The coupling in question is effectively induced only through the techni-fermion loops. In both cases, we find that the coupling is essentially determined by the mass-squared of the weak bosons over the dilaton decay constant. |
2406.08016 | Robert J. Perry | {\L}ukasz Bibrzycki, Nadine Hammoud, Vincent Mathieu, Robert J. Perry,
Alex Akridge, C\'esar Fern\'andez-Ram\'irez, Gloria Monta\~na, Alessandro
Pilloni, Arkaitz Rodas, Vanamali Shastry, Wyatt A. Smith, Daniel Winney, Adam
P. Szczepaniak | Studying $\pi^+\pi^-$ photoproduction beyond Pomeron exchange | 30 pages, 21 figures | null | null | JLAB-THY-24-4078 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Forward photoproduction of $\pi^+\pi^-$ pairs with invariant mass of the
order of $m_\rho\sim 770$ MeV is traditionally understood to be produced via
Pomeron exchange. Based on a detailed analysis of the CLAS photoproduction
data, it is shown that the dynamics of two-pion photoproduction for $|t|\gtrsim
0.5$ GeV$^2$ cannot be explained by Pomeron exchange alone. This motivates the
development of a new theoretical model of two-pion photoproduction which
incorporates both two-pion and pion-nucleon resonant contributions. After
fitting free parameters, the model provides an excellent description of the low
moments of the angular distribution measured at CLAS, and enables an assessment
of the relative contributions of particular production mechanisms and an
interpretation of the various features of the data in terms of these
mechanisms.
| [
{
"created": "Wed, 12 Jun 2024 09:11:49 GMT",
"version": "v1"
}
] | 2024-06-13 | [
[
"Bibrzycki",
"Łukasz",
""
],
[
"Hammoud",
"Nadine",
""
],
[
"Mathieu",
"Vincent",
""
],
[
"Perry",
"Robert J.",
""
],
[
"Akridge",
"Alex",
""
],
[
"Fernández-Ramírez",
"César",
""
],
[
"Montaña",
"Gloria",
""
],
[
"Pilloni",
"Alessandro",
""
],
[
"Rodas",
"Arkaitz",
""
],
[
"Shastry",
"Vanamali",
""
],
[
"Smith",
"Wyatt A.",
""
],
[
"Winney",
"Daniel",
""
],
[
"Szczepaniak",
"Adam P.",
""
]
] | Forward photoproduction of $\pi^+\pi^-$ pairs with invariant mass of the order of $m_\rho\sim 770$ MeV is traditionally understood to be produced via Pomeron exchange. Based on a detailed analysis of the CLAS photoproduction data, it is shown that the dynamics of two-pion photoproduction for $|t|\gtrsim 0.5$ GeV$^2$ cannot be explained by Pomeron exchange alone. This motivates the development of a new theoretical model of two-pion photoproduction which incorporates both two-pion and pion-nucleon resonant contributions. After fitting free parameters, the model provides an excellent description of the low moments of the angular distribution measured at CLAS, and enables an assessment of the relative contributions of particular production mechanisms and an interpretation of the various features of the data in terms of these mechanisms. |
1008.2570 | Tony Gherghetta | Tony Gherghetta | TASI Lectures on a Holographic View of Beyond the Standard Model Physics | 66 pages, 15 figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We provide an introduction to the physics of a warped extra dimension and the
AdS/CFT correspondence. An AdS/CFT dictionary is given which leads to a 4D
holographic view of the 5th dimension. With a particular emphasis on beyond the
standard model physics, this provides a window into the strong dynamics
associated with either electroweak symmetry breaking or supersymmetry breaking.
In this way hierarchies associated with either the electroweak or supersymmetry
breaking scale, together with the fermion mass spectrum, can be addressed in a
consistent framework.
| [
{
"created": "Mon, 16 Aug 2010 04:15:49 GMT",
"version": "v1"
}
] | 2010-08-17 | [
[
"Gherghetta",
"Tony",
""
]
] | We provide an introduction to the physics of a warped extra dimension and the AdS/CFT correspondence. An AdS/CFT dictionary is given which leads to a 4D holographic view of the 5th dimension. With a particular emphasis on beyond the standard model physics, this provides a window into the strong dynamics associated with either electroweak symmetry breaking or supersymmetry breaking. In this way hierarchies associated with either the electroweak or supersymmetry breaking scale, together with the fermion mass spectrum, can be addressed in a consistent framework. |
1610.02189 | Richard Keith Ellis | John M. Campbell and R. Keith Ellis | Top-quark loop corrections in Z+jet and Z+2 jet production | 33 pages, 9 figures | null | 10.1007/JHEP01(2017)020 | Fermilab-PUB-16-429-T, IPPP/16/88 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The sophistication of current predictions for $Z+$jet production at hadron
colliders necessitates a re-evaluation of any approximations inherent in the
theoretical calculations. In this paper we address one such issue, the
inclusion of mass effects in top-quark loops. We ameliorate an existing
calculation of $Z+1$~jet and $Z+2$~jet production by presenting exact analytic
formulae for amplitudes containing top-quark loops that enter at
next-to-leading order in QCD. Although approximations based on an expansion in
powers of $1/m_t^2$ can lead to poor high-energy behavior, an exact treatment
of top-quark loops demonstrates that their effect is small and has limited
phenomenological interest.
| [
{
"created": "Fri, 7 Oct 2016 08:49:28 GMT",
"version": "v1"
}
] | 2017-02-01 | [
[
"Campbell",
"John M.",
""
],
[
"Ellis",
"R. Keith",
""
]
] | The sophistication of current predictions for $Z+$jet production at hadron colliders necessitates a re-evaluation of any approximations inherent in the theoretical calculations. In this paper we address one such issue, the inclusion of mass effects in top-quark loops. We ameliorate an existing calculation of $Z+1$~jet and $Z+2$~jet production by presenting exact analytic formulae for amplitudes containing top-quark loops that enter at next-to-leading order in QCD. Although approximations based on an expansion in powers of $1/m_t^2$ can lead to poor high-energy behavior, an exact treatment of top-quark loops demonstrates that their effect is small and has limited phenomenological interest. |
2007.08125 | Xiao-Dong Ma | Yi Liao and Xiao-Dong Ma | An explicit construction of the dimension-9 operator basis in the
standard model effective field theory | 31 pages, 10 tables; Section 3 is expanded with discussion on
relevant phenomenologies; Typos are corrected; The version to be appear in
JHEP | JHEP11(2020)152 | 10.1007/JHEP11(2020)152 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate systematically dimension-9 operators in the standard model
effective field theory which contains only standard model fields and respects
its gauge symmetry. With the help of the Hilbert series approach to classifying
operators according to their lepton and baryon numbers and their field
contents, we construct the basis of operators explicitly. We remove redundant
operators by employing various kinematic and algebraic relations including
integration by parts, equations of motion, Schouten identities, Dirac matrix
and Fierz identities, and Bianchi identities. We confirm counting of
independent operators by analyzing their flavor symmetry relations. All
operators violate lepton or baryon number or both, and are thus non-Hermitian.
Including Hermitian conjugated operators there are $384|^{\Delta L=\pm
2}_{\Delta B=0}+10|^{\Delta L=0}_{\Delta B=\pm 2}+4|^{\Delta L=\pm3}_{\Delta
B=\pm1}+236|^{\Delta L=\mp 1}_{\Delta B=\pm1}$ operators without referring to
fermion generations, and $44874|^{\Delta L=\pm 2}_{\Delta B=0}+2862|^{\Delta
L=0}_{\Delta B=\pm 2}+486|^{\Delta L=\pm3}_{\Delta B=\pm1}+42234|^{\Delta L=\pm
1}_{\Delta B=\mp1}$ operators when three generations of fermions are referred
to, where $\Delta L,~\Delta B$ denote the net lepton and baryon numbers of the
operators. Our result provides a starting point for consistent phenomenological
studies associated with dimension-9 operators.
| [
{
"created": "Thu, 16 Jul 2020 05:55:30 GMT",
"version": "v1"
},
{
"created": "Wed, 28 Oct 2020 12:13:47 GMT",
"version": "v2"
}
] | 2020-11-30 | [
[
"Liao",
"Yi",
""
],
[
"Ma",
"Xiao-Dong",
""
]
] | We investigate systematically dimension-9 operators in the standard model effective field theory which contains only standard model fields and respects its gauge symmetry. With the help of the Hilbert series approach to classifying operators according to their lepton and baryon numbers and their field contents, we construct the basis of operators explicitly. We remove redundant operators by employing various kinematic and algebraic relations including integration by parts, equations of motion, Schouten identities, Dirac matrix and Fierz identities, and Bianchi identities. We confirm counting of independent operators by analyzing their flavor symmetry relations. All operators violate lepton or baryon number or both, and are thus non-Hermitian. Including Hermitian conjugated operators there are $384|^{\Delta L=\pm 2}_{\Delta B=0}+10|^{\Delta L=0}_{\Delta B=\pm 2}+4|^{\Delta L=\pm3}_{\Delta B=\pm1}+236|^{\Delta L=\mp 1}_{\Delta B=\pm1}$ operators without referring to fermion generations, and $44874|^{\Delta L=\pm 2}_{\Delta B=0}+2862|^{\Delta L=0}_{\Delta B=\pm 2}+486|^{\Delta L=\pm3}_{\Delta B=\pm1}+42234|^{\Delta L=\pm 1}_{\Delta B=\mp1}$ operators when three generations of fermions are referred to, where $\Delta L,~\Delta B$ denote the net lepton and baryon numbers of the operators. Our result provides a starting point for consistent phenomenological studies associated with dimension-9 operators. |
hep-ph/0009217 | Eugene Levin | Eugene Levin (Tel Aviv U./DESY),Uri Maor (Tel Aviv U.) | A manifestation of a gluon saturation in e-A DIS | 13 pages,11 figures in eps files | null | null | TAUP-2643-2000 | hep-ph | null | This is a short presentation of our talks given at eRHIC Workshop at the BNL.
We give here a status report of our attempts to understand how gluon saturation
will manifest itself in deep inelastic scattering with nuclei. This summary
reflects our current understanding and shows directions of our research rather
then a final answer to the question. Nevertheless, we are able to share with
our reader our tentative answer to the question:``Why do we need to measure DIS
with nuclei and why these data will be complementary to the information
obtained from proton DIS".
| [
{
"created": "Tue, 19 Sep 2000 09:33:54 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Levin",
"Eugene",
"",
"Tel Aviv U./DESY"
],
[
"Maor",
"Uri",
"",
"Tel Aviv U."
]
] | This is a short presentation of our talks given at eRHIC Workshop at the BNL. We give here a status report of our attempts to understand how gluon saturation will manifest itself in deep inelastic scattering with nuclei. This summary reflects our current understanding and shows directions of our research rather then a final answer to the question. Nevertheless, we are able to share with our reader our tentative answer to the question:``Why do we need to measure DIS with nuclei and why these data will be complementary to the information obtained from proton DIS". |
hep-ph/0512338 | Marian Jurcisin | E. Jurcisinova, M. Jurcisin | Focus points and the Lightest Higgs Boson Mass in the Minimal
Supersymmetric Standard Model | latex, 7 pages, 4 figures, references are added, one e-mail is
corrected | Mod.Phys.Lett.A21:1923-1929,2006 | 10.1142/S021773230602130X | null | hep-ph | null | We investigate focus points of the renormalization group equations of the
Minimal Supersymmetric Standard Model. We show that within this model the up-
and down-type Higgs mass soft supersymmetry breaking parameters have focus
point behavior at the electroweak scale simultaneously when appropriate
conditions are fulfilled. The focus point scenario is holding for large $\tan
\beta$. This two focus point scenario allows to fix the pole top-quark mass
which is within the experimentally allowed interval. The main goal of the
present paper is the investigation of the influence of the existence of focus
points on the determination of the mass of the lightest Higgs boson.
| [
{
"created": "Tue, 27 Dec 2005 12:48:26 GMT",
"version": "v1"
},
{
"created": "Fri, 20 Jan 2006 08:36:11 GMT",
"version": "v2"
}
] | 2010-11-11 | [
[
"Jurcisinova",
"E.",
""
],
[
"Jurcisin",
"M.",
""
]
] | We investigate focus points of the renormalization group equations of the Minimal Supersymmetric Standard Model. We show that within this model the up- and down-type Higgs mass soft supersymmetry breaking parameters have focus point behavior at the electroweak scale simultaneously when appropriate conditions are fulfilled. The focus point scenario is holding for large $\tan \beta$. This two focus point scenario allows to fix the pole top-quark mass which is within the experimentally allowed interval. The main goal of the present paper is the investigation of the influence of the existence of focus points on the determination of the mass of the lightest Higgs boson. |
2201.00048 | Giorgio Busoni | Giorgio Busoni | Capture of Dark Matter in Neutron Stars | 6 pages, 2 figures | null | 10.3103/S0027134922020205 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The extreme conditions in Neutron Stars make them ideal test facilities for
fundamental interactions. A Neutron Star can capture Dark Matter via
scattering. As a result of the scattering, Dark Matter kinetic energy is
transferred to the star. An observational consequence of this can be the
warming of old neutron stars to near-infrared temperatures. Different
approximations or simplifications have been applied to previous analyses of the
capture process. In this article, we summarise a significantly improved
treatment of Dark Matter capture, which properly accounts for all relevant
physical effects over a wide range of Dark Matter masses. Among them are
gravitational focusing, a fully relativistic scattering treatment, Pauli
blocking, neutron star opacity and multiple scattering effects. This paper
cites general expressions that allow the capture rate to be computed
numerically, and simplified expressions for particular types of interactions or
mass regimes, which greatly increase the efficiency of computation. As a result
of our method, we are able to model the scattering of Dark Matter from any
neutron star constituent as well as the capture of Dark Matter in other compact
objects. Our results are applied to scattering of Dark Matter from neutrons,
protons, leptons and exotic baryons.
| [
{
"created": "Fri, 31 Dec 2021 20:18:15 GMT",
"version": "v1"
},
{
"created": "Tue, 15 Mar 2022 07:05:56 GMT",
"version": "v2"
}
] | 2022-09-21 | [
[
"Busoni",
"Giorgio",
""
]
] | The extreme conditions in Neutron Stars make them ideal test facilities for fundamental interactions. A Neutron Star can capture Dark Matter via scattering. As a result of the scattering, Dark Matter kinetic energy is transferred to the star. An observational consequence of this can be the warming of old neutron stars to near-infrared temperatures. Different approximations or simplifications have been applied to previous analyses of the capture process. In this article, we summarise a significantly improved treatment of Dark Matter capture, which properly accounts for all relevant physical effects over a wide range of Dark Matter masses. Among them are gravitational focusing, a fully relativistic scattering treatment, Pauli blocking, neutron star opacity and multiple scattering effects. This paper cites general expressions that allow the capture rate to be computed numerically, and simplified expressions for particular types of interactions or mass regimes, which greatly increase the efficiency of computation. As a result of our method, we are able to model the scattering of Dark Matter from any neutron star constituent as well as the capture of Dark Matter in other compact objects. Our results are applied to scattering of Dark Matter from neutrons, protons, leptons and exotic baryons. |
hep-ph/9711232 | Alessandro Strumia | R. Barbieri | Unified theories | 11 pages, 2 figures | null | null | talk given at LP97 | hep-ph | null | The present status of Unified Theories is summarized with special emphasis on
their possible experimental tests. Outline: i) Unification of couplings; ii)
Where can a positive signal come from? iii) HERA anomaly and Unification; iv)
Recent progress in model building; v) Flavour and Unification.
| [
{
"created": "Tue, 4 Nov 1997 16:14:31 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Barbieri",
"R.",
""
]
] | The present status of Unified Theories is summarized with special emphasis on their possible experimental tests. Outline: i) Unification of couplings; ii) Where can a positive signal come from? iii) HERA anomaly and Unification; iv) Recent progress in model building; v) Flavour and Unification. |
hep-ph/9409410 | null | AD Martin, WJ Stirling and RG Roberts | Parton Distributions for Low Q^2 | University of Durham preprint DTP/94/78 Rutherford Appleton
Laboratory preprint RAL-94-104 11 pages and 9 figures available from authors | Phys.Rev. D51 (1995) 4756-4762 | 10.1103/PhysRevD.51.4756 | null | hep-ph | null | We extend the MRS(A) set of parton distributions, which provides an
up-to-date description of the structure of the proton probed by hard
interactions, into the region of $Q^2$ below $5\ {\rm GeV}^2$. After
physically-motivated modifications, we obtain a smooth description of the data
on the structure function $F_2(x,Q^2)$ all the way from $Q^2 = 10^{-1}$ to
$10^3\ {\rm GeV}^2$.
| [
{
"created": "Mon, 26 Sep 1994 09:27:31 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Martin",
"AD",
""
],
[
"Stirling",
"WJ",
""
],
[
"Roberts",
"RG",
""
]
] | We extend the MRS(A) set of parton distributions, which provides an up-to-date description of the structure of the proton probed by hard interactions, into the region of $Q^2$ below $5\ {\rm GeV}^2$. After physically-motivated modifications, we obtain a smooth description of the data on the structure function $F_2(x,Q^2)$ all the way from $Q^2 = 10^{-1}$ to $10^3\ {\rm GeV}^2$. |
1712.03533 | Bruce Hoeneisen | B. Hoeneisen | Constraints on neutrino masses from Baryon Acoustic Oscillation
measurements | 2 pages, 0 figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | From 21 independent Baryon Acoustic Oscillation (BAO) measurements we obtain
the following sum of masses of active Dirac or Majorana neutrinos: $\sum m_\nu
= 0.711 - 0.335 \cdot \delta h + 0.050 \cdot \delta b \pm 0.063 \textrm{ eV,}$
where $\delta h \equiv (h - 0.678) / 0.009$ and $\delta b \equiv (\Omega_b h^2
- 0.02226) / 0.00023$. This result may be combined with independent
measurements that constrain the parameters $\sum m_\nu$, $h$, and $\Omega_b
h^2$. For $\delta h = \pm 1$ and $\delta b = \pm 1$, we obtain $m_\nu < 0.43$
eV at 95\% confidence.
| [
{
"created": "Sun, 10 Dec 2017 14:17:30 GMT",
"version": "v1"
}
] | 2017-12-12 | [
[
"Hoeneisen",
"B.",
""
]
] | From 21 independent Baryon Acoustic Oscillation (BAO) measurements we obtain the following sum of masses of active Dirac or Majorana neutrinos: $\sum m_\nu = 0.711 - 0.335 \cdot \delta h + 0.050 \cdot \delta b \pm 0.063 \textrm{ eV,}$ where $\delta h \equiv (h - 0.678) / 0.009$ and $\delta b \equiv (\Omega_b h^2 - 0.02226) / 0.00023$. This result may be combined with independent measurements that constrain the parameters $\sum m_\nu$, $h$, and $\Omega_b h^2$. For $\delta h = \pm 1$ and $\delta b = \pm 1$, we obtain $m_\nu < 0.43$ eV at 95\% confidence. |
1306.1612 | Maryam Soleymaninia | M. Soleymaninia, A. N. Khorramian, S. M. Moosavi Nejad, F. Arbabifar | Determination of pion and kaon fragmentation functions including spin
asymmetries data in a global analysis | 18 pages, 16 figures and 8 tables | Phys. Rev. D 88, 054019 (2013) | 10.1103/PhysRevD.88.054019 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present new functional form of pion and kaon fragmentation functions up to
next-to-leading order obtained through a global fit to single-inclusive
electron-positron annihilation data and also employ, the semi-inclusive deep
inelastic scattering asymmetry data from HERMES and COMPASS to determine
fragmentation functions. Also we apply very recently electron-positron
annihilation data from BaBar and Belle at $\sqrt{s}=10.54$ GeV and
$\sqrt{s}=10.52$ GeV, respectively. In this analysis we consider the impression
of semi-inclusive deep inelastic scattering asymmetry data on the fragmentation
functions, where the produced hadrons of different electric charge are
identified. We break symmetry assumption between quark and anti-quark
fragmentation functions for favored partons by using the asymmetry data. The
results of our analysis are in good agreement with electron-positron
annihilation data and also with all the semi-inclusive deep inelastic
scattering asymmetry data. Also we apply the obtained fragmentation functions
to predict the scaled-energy distribution of $\pi^+/K^+$ inclusively produced
in top-quark decays at next-to-leading order using the zero-mass
variable-flavor-number scheme exploiting the universality and scaling
violations of fragmentation functions.
| [
{
"created": "Fri, 7 Jun 2013 05:15:36 GMT",
"version": "v1"
},
{
"created": "Fri, 14 Feb 2014 05:31:08 GMT",
"version": "v2"
}
] | 2019-03-08 | [
[
"Soleymaninia",
"M.",
""
],
[
"Khorramian",
"A. N.",
""
],
[
"Nejad",
"S. M. Moosavi",
""
],
[
"Arbabifar",
"F.",
""
]
] | We present new functional form of pion and kaon fragmentation functions up to next-to-leading order obtained through a global fit to single-inclusive electron-positron annihilation data and also employ, the semi-inclusive deep inelastic scattering asymmetry data from HERMES and COMPASS to determine fragmentation functions. Also we apply very recently electron-positron annihilation data from BaBar and Belle at $\sqrt{s}=10.54$ GeV and $\sqrt{s}=10.52$ GeV, respectively. In this analysis we consider the impression of semi-inclusive deep inelastic scattering asymmetry data on the fragmentation functions, where the produced hadrons of different electric charge are identified. We break symmetry assumption between quark and anti-quark fragmentation functions for favored partons by using the asymmetry data. The results of our analysis are in good agreement with electron-positron annihilation data and also with all the semi-inclusive deep inelastic scattering asymmetry data. Also we apply the obtained fragmentation functions to predict the scaled-energy distribution of $\pi^+/K^+$ inclusively produced in top-quark decays at next-to-leading order using the zero-mass variable-flavor-number scheme exploiting the universality and scaling violations of fragmentation functions. |
0801.2361 | Seung Woo Ham | S. W. Ham, Taeil Hur, P. Ko, and S.K. OH | Neutral scalar Higgs bosons in the USSM at the LHC | 18 pages; changed content; JPhysG | J.Phys.G35:095007,2008 | 10.1088/0954-3899/35/9/095007 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the possibility of discovering neutral scalar Higgs bosons in the
$U(1)'$-extended supersymmetric standard model (USSM) at the CERN Large Hadron
Collider (LHC), by examining their productions via the exotic quark loop in the
gluon fusion process at leading order. It is possible in some parameter region
that the neutral scalar Higgs bosons may have stronger couplings with the
exotic quarks than with top quark. In this case, the exotic quarks may
contribute more significantly than top quark in productions of the neutral
scalar Higgs bosons in the gluon fusion process. We find that there is indeed
some parameter region in the USSM that supports our speculations.
| [
{
"created": "Tue, 15 Jan 2008 18:55:31 GMT",
"version": "v1"
},
{
"created": "Tue, 18 Mar 2008 02:12:27 GMT",
"version": "v2"
},
{
"created": "Fri, 18 Jul 2008 00:07:44 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Ham",
"S. W.",
""
],
[
"Hur",
"Taeil",
""
],
[
"Ko",
"P.",
""
],
[
"OH",
"S. K.",
""
]
] | We study the possibility of discovering neutral scalar Higgs bosons in the $U(1)'$-extended supersymmetric standard model (USSM) at the CERN Large Hadron Collider (LHC), by examining their productions via the exotic quark loop in the gluon fusion process at leading order. It is possible in some parameter region that the neutral scalar Higgs bosons may have stronger couplings with the exotic quarks than with top quark. In this case, the exotic quarks may contribute more significantly than top quark in productions of the neutral scalar Higgs bosons in the gluon fusion process. We find that there is indeed some parameter region in the USSM that supports our speculations. |
0705.4525 | Gary Goldstein | Gary R. Goldstein (1) and Kameshwar C. Wali (2) ((1) Tufts University,
(2) Syracuse University) | Baryons and Mesons with Beauty | 9 pages, 5 figures, plain LateX | null | null | null | hep-ph | null | Recent experimental findings of several mesons and baryons with "beauty" and
"charm" as flavors remind us of the days when strangeness was discovered, and
how its inclusion led to SU(3)-flavor symmetry with enormous success in the
classification of the "proliferated" states into SU(3) multiplets. One of the
key elements was the successful application of the first order perturbation in
symmetry breaking, albeit what then appeared to be huge mass differences, and
the prediction of new states that were confirmed by experiments. In this note,
we venture into the past and, applying the same techniques, predict some new
"beauty-" and "charm-" flavored hadrons. If these new states are confirmed
experimentally, it may provide a useful phenomenological model for classifying
numerous states that are found to be in the PDG data and could invite further
theoretical challenges towards our understanding of symmetry breaking.
| [
{
"created": "Thu, 31 May 2007 06:34:06 GMT",
"version": "v1"
}
] | 2007-06-01 | [
[
"Goldstein",
"Gary R.",
""
],
[
"Wali",
"Kameshwar C.",
""
]
] | Recent experimental findings of several mesons and baryons with "beauty" and "charm" as flavors remind us of the days when strangeness was discovered, and how its inclusion led to SU(3)-flavor symmetry with enormous success in the classification of the "proliferated" states into SU(3) multiplets. One of the key elements was the successful application of the first order perturbation in symmetry breaking, albeit what then appeared to be huge mass differences, and the prediction of new states that were confirmed by experiments. In this note, we venture into the past and, applying the same techniques, predict some new "beauty-" and "charm-" flavored hadrons. If these new states are confirmed experimentally, it may provide a useful phenomenological model for classifying numerous states that are found to be in the PDG data and could invite further theoretical challenges towards our understanding of symmetry breaking. |
1103.0857 | Daijiro Suematsu | Daijiro Suematsu | Thermal leptogenesis in a TeV scale model for neutrino masses | 21 pages, 3 figures, v2:large improvement by the analysis of
Boltzmann equations, title changed, v3: abstract rewritten, some references
added, accepted version for publication | null | 10.1140/epjc/s10052-012-1951-z | KANAZAWA-11-04 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | It is known that the radiative neutrino mass model proposed by Ma could be a
consistent framework for dark matter, leptogenesis and suppressed lepton flavor
violation if a neutral component of the inert doublet is identified as dark
matter and the right-handed neutrinos are of O(10^7) GeV or more. In the same
model we explore another scenario such that right-handed neutrinos are in TeV
regions and their lightest one is dark matter. It is shown that this scenario
requires fine mass degeneracy to generate the appropriate baryon number
asymmetry as in the case of resonant leptogenesis. As long as we impose the
model to induce the baryon number asymmetry on the basis of thermal
leptogenesis, we find that dark matter abundance can not be explained. If this
scenario is adopted, the model has to be extended to include some new mechanism
to explain it.
| [
{
"created": "Fri, 4 Mar 2011 10:32:40 GMT",
"version": "v1"
},
{
"created": "Mon, 6 Feb 2012 04:39:20 GMT",
"version": "v2"
},
{
"created": "Wed, 14 Mar 2012 04:25:51 GMT",
"version": "v3"
}
] | 2015-05-27 | [
[
"Suematsu",
"Daijiro",
""
]
] | It is known that the radiative neutrino mass model proposed by Ma could be a consistent framework for dark matter, leptogenesis and suppressed lepton flavor violation if a neutral component of the inert doublet is identified as dark matter and the right-handed neutrinos are of O(10^7) GeV or more. In the same model we explore another scenario such that right-handed neutrinos are in TeV regions and their lightest one is dark matter. It is shown that this scenario requires fine mass degeneracy to generate the appropriate baryon number asymmetry as in the case of resonant leptogenesis. As long as we impose the model to induce the baryon number asymmetry on the basis of thermal leptogenesis, we find that dark matter abundance can not be explained. If this scenario is adopted, the model has to be extended to include some new mechanism to explain it. |
1102.2397 | Andrzej Bialas | A. Bialas | Balance functions revisited | null | Phys.Rev.C83:024914,2011 | 10.1103/PhysRevC.83.024914 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The idea of glue clusters, i.e. short-range correlations in the quark-gluon
plasma close to freeze-out, is used to estimate the width of balance functions
in momentum space. A good agreement is found with the recent measurements of
STAR collaboration for central $Au-Au$ collisions.
| [
{
"created": "Fri, 11 Feb 2011 17:17:16 GMT",
"version": "v1"
}
] | 2011-03-22 | [
[
"Bialas",
"A.",
""
]
] | The idea of glue clusters, i.e. short-range correlations in the quark-gluon plasma close to freeze-out, is used to estimate the width of balance functions in momentum space. A good agreement is found with the recent measurements of STAR collaboration for central $Au-Au$ collisions. |
0710.5581 | Sho Ozaki | S. Ozaki, H. Nagahiro and A. Hosaka (RCNP, Osaka University) | Magnetic interaction induced by the anomaly in kaon-photoproductions | 8 pages, 3 figures | Phys.Lett.B665:178-181,2008 | 10.1016/j.physletb.2008.06.020 | RCNP-Th07015 | hep-ph | null | We study the role of magnetic interaction in the photoproduction of the kaon
and hyperon. We find that the inclusion of a higher order diagram induced by
the Wess-Zumio-Witten term has a significant contribution to the magnetic
amplitude, which is compatible to the observed photon asymmetry in the forward
angle region. This enables us to use the K^* coupling constants which have been
determined in a microscopic way rather than the phenomenological ones which
differ largely from the microscopic ones.
| [
{
"created": "Tue, 30 Oct 2007 07:27:03 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Ozaki",
"S.",
"",
"RCNP, Osaka University"
],
[
"Nagahiro",
"H.",
"",
"RCNP, Osaka University"
],
[
"Hosaka",
"A.",
"",
"RCNP, Osaka University"
]
] | We study the role of magnetic interaction in the photoproduction of the kaon and hyperon. We find that the inclusion of a higher order diagram induced by the Wess-Zumio-Witten term has a significant contribution to the magnetic amplitude, which is compatible to the observed photon asymmetry in the forward angle region. This enables us to use the K^* coupling constants which have been determined in a microscopic way rather than the phenomenological ones which differ largely from the microscopic ones. |
hep-ph/9306236 | S. F. King | Stephen F. King | Low Scale Technicolour at LEP | 12 pages+1 figure (available by post), Latex, SHEP92/93-22 | Phys.Lett. B314 (1993) 364-370 | 10.1016/0370-2693(93)91250-Q | null | hep-ph | null | We discuss the phenomenology of an $SU(2)_{TC}$ technicolour model with a low
technicolour confinement scale ${\Lambda}_{TC} \sim 50-100 GeV$. Such a low
technicolour scale may give rise to the first hints of technicolour being seen
at LEPI and spectacular technicolour signals at LEPII.
| [
{
"created": "Mon, 7 Jun 1993 11:48:57 GMT",
"version": "v1"
}
] | 2009-10-22 | [
[
"King",
"Stephen F.",
""
]
] | We discuss the phenomenology of an $SU(2)_{TC}$ technicolour model with a low technicolour confinement scale ${\Lambda}_{TC} \sim 50-100 GeV$. Such a low technicolour scale may give rise to the first hints of technicolour being seen at LEPI and spectacular technicolour signals at LEPII. |
hep-ph/9803450 | Juan Carlos Montero | J. C. Montero, V. Pleitez and M. C. Rodriguez | Left-right asymmetries in polarized $e-\mu$ scattering | RevTeX, 9 pages, 5 gif figures | Phys.Rev. D58 (1998) 097505 | 10.1103/PhysRevD.58.097505 | IFT-P.019/98 | hep-ph | null | We consider, in the electroweak standard model context, several left-right
asymmetries in $\mu e$ elastic scattering at fixed target and collider
experiments. For the former case, we show that the muon mass effects are
important in a wide energy range. We also show that these asymmetries are
sensitive to the electroweak mixing angle $\theta_W$. The effect of an extra
$Z'$ neutral vector boson appearing in a 331 model is also considered. The
capabilities of these asymmetries in the search of this extra $Z'$ are
addressed.
| [
{
"created": "Wed, 25 Mar 1998 20:19:56 GMT",
"version": "v1"
}
] | 2016-09-06 | [
[
"Montero",
"J. C.",
""
],
[
"Pleitez",
"V.",
""
],
[
"Rodriguez",
"M. C.",
""
]
] | We consider, in the electroweak standard model context, several left-right asymmetries in $\mu e$ elastic scattering at fixed target and collider experiments. For the former case, we show that the muon mass effects are important in a wide energy range. We also show that these asymmetries are sensitive to the electroweak mixing angle $\theta_W$. The effect of an extra $Z'$ neutral vector boson appearing in a 331 model is also considered. The capabilities of these asymmetries in the search of this extra $Z'$ are addressed. |
2211.06949 | Taewook Youn | Matthew Gignac, Can Kilic, Rakhi Mahbubani, Taewook Youn | Optimizing pixel tracklet searches for shorter lifetimes | 27 pages, 12 figures; v2: Minor changes. Matches published version | null | 10.1007/JHEP03(2023)040 | UTWI-14-2022, RBI-ThPhys-2022-41 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Pixel tracklets, disappearing tracks reconstructed with only pixel hits, have
proven to be a promising technique in LHC analyses to search for dark matter
candidates at the LHC that belong to a nearly-degenerate electroweak multiplet.
However, a Pseudo-Dirac electroweak doublet fermion, arguably the most
interesting such possibility, has a shorter lifetime and therefore existing
tracklet searches are less sensitive in this case. We assess the performance of
a tracklet search optimized for shorter lifetimes by requiring only three pixel
hits for the tracklet reconstruction, and by demanding an accompanying soft
track for suppressing backgrounds. We estimate how far the sensitivity of
existing searches can be extended into the region of parameter space with this
optimized search.
| [
{
"created": "Sun, 13 Nov 2022 16:46:07 GMT",
"version": "v1"
},
{
"created": "Wed, 8 Mar 2023 19:21:54 GMT",
"version": "v2"
}
] | 2023-03-22 | [
[
"Gignac",
"Matthew",
""
],
[
"Kilic",
"Can",
""
],
[
"Mahbubani",
"Rakhi",
""
],
[
"Youn",
"Taewook",
""
]
] | Pixel tracklets, disappearing tracks reconstructed with only pixel hits, have proven to be a promising technique in LHC analyses to search for dark matter candidates at the LHC that belong to a nearly-degenerate electroweak multiplet. However, a Pseudo-Dirac electroweak doublet fermion, arguably the most interesting such possibility, has a shorter lifetime and therefore existing tracklet searches are less sensitive in this case. We assess the performance of a tracklet search optimized for shorter lifetimes by requiring only three pixel hits for the tracklet reconstruction, and by demanding an accompanying soft track for suppressing backgrounds. We estimate how far the sensitivity of existing searches can be extended into the region of parameter space with this optimized search. |
hep-ph/0106131 | Jure Zupan | S. Fajfer, P. Singer, J. Zupan | The Search for New Physics in D^0 --> gamma gamma Decay | 7 pages, 3 figures, Contributed Paper for LPO1 | null | null | null | hep-ph | null | We present main results of the investigation of the rare decay mode D^0
-->gamma gamma, in which the long distance contributions are expected to be
dominant. Using the Heavy Quark Chiral Lagrangian we have considered the
anomaly contribution which relates to the annihilation part of the weak
Lagrangian and the one - loop pi, K diagrams. The loop contributions which are
proportional to g and contain the a_1 Wilson coefficient are found to dominate
the decay amplitude. The branching ratio is then calculated to be (1.0+-0.5)x
10^{-8}. Observation of an order of magnitude larger branching ratio could
signal new physics.
| [
{
"created": "Wed, 13 Jun 2001 08:06:25 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Fajfer",
"S.",
""
],
[
"Singer",
"P.",
""
],
[
"Zupan",
"J.",
""
]
] | We present main results of the investigation of the rare decay mode D^0 -->gamma gamma, in which the long distance contributions are expected to be dominant. Using the Heavy Quark Chiral Lagrangian we have considered the anomaly contribution which relates to the annihilation part of the weak Lagrangian and the one - loop pi, K diagrams. The loop contributions which are proportional to g and contain the a_1 Wilson coefficient are found to dominate the decay amplitude. The branching ratio is then calculated to be (1.0+-0.5)x 10^{-8}. Observation of an order of magnitude larger branching ratio could signal new physics. |
1401.0391 | Wen-Fei Wang | Wen-Fei Wang, Xin Yu, Cai-Dian L\"u, and Zhen-Jun Xiao | Semileptonic decays $B_c^+\to D^{(*)}_{(s)}(l^+\nu,l^+l^-,\nu\bar\nu)$
in the perturbative QCD approach | 13 pages, 1 figure | Phys. Rev. D 90, 094018 (2014) | 10.1103/PhysRevD.90.094018 | null | hep-ph | http://creativecommons.org/licenses/by/3.0/ | In this paper we study the semileptonic decays of $B_c^+\to
D^{(*)}_{(s)}(l^+\nu_l,l^+l^-,\nu\bar\nu)$ (here $l$ stands for $e$, $\mu$, or
$\tau$). After evaluating the $B_c^+ \to (D_{(s)},D^*_{(s)})$ transition form
factors $F_{0,+,T}(q^2)$ and $V(q^2), A_{0,1,2}(q^2), T_{1,2,3}(q^2)$ by
employing the perturbative QCD factorization approach, we calculate the
branching ratios for all these semileptonic decays. Our predictions for the
values of the $B_c^+ \to D_{(s)}$ and $B_c^+ \to D^*_{(s)}$ transition form
factors are consistent with those obtained by using other methods. The
branching ratios of the decay modes with $\bar\nu\nu$ are almost an order of
magnitude larger than the corresponding decays with $l^+l^-$ after the
summation over the three neutrino generations. The branching ratios for the
decays with $b\to d$ transitions are much smaller than those decays with the
$b\to s$ transitions, due to the Cabibbo-Kobayashi-Maskawa suppression. We
define ratios $R_D$ and $R_{D^*}$ for the branching ratios with the $\tau$
lepton versus $\mu$, $e$ lepton final states to cancel the uncertainties of the
form factors, which could possibly be tested in the near future.
| [
{
"created": "Thu, 2 Jan 2014 08:55:35 GMT",
"version": "v1"
},
{
"created": "Sun, 13 Jul 2014 03:33:10 GMT",
"version": "v2"
},
{
"created": "Sat, 15 Nov 2014 06:28:02 GMT",
"version": "v3"
}
] | 2014-11-18 | [
[
"Wang",
"Wen-Fei",
""
],
[
"Yu",
"Xin",
""
],
[
"Lü",
"Cai-Dian",
""
],
[
"Xiao",
"Zhen-Jun",
""
]
] | In this paper we study the semileptonic decays of $B_c^+\to D^{(*)}_{(s)}(l^+\nu_l,l^+l^-,\nu\bar\nu)$ (here $l$ stands for $e$, $\mu$, or $\tau$). After evaluating the $B_c^+ \to (D_{(s)},D^*_{(s)})$ transition form factors $F_{0,+,T}(q^2)$ and $V(q^2), A_{0,1,2}(q^2), T_{1,2,3}(q^2)$ by employing the perturbative QCD factorization approach, we calculate the branching ratios for all these semileptonic decays. Our predictions for the values of the $B_c^+ \to D_{(s)}$ and $B_c^+ \to D^*_{(s)}$ transition form factors are consistent with those obtained by using other methods. The branching ratios of the decay modes with $\bar\nu\nu$ are almost an order of magnitude larger than the corresponding decays with $l^+l^-$ after the summation over the three neutrino generations. The branching ratios for the decays with $b\to d$ transitions are much smaller than those decays with the $b\to s$ transitions, due to the Cabibbo-Kobayashi-Maskawa suppression. We define ratios $R_D$ and $R_{D^*}$ for the branching ratios with the $\tau$ lepton versus $\mu$, $e$ lepton final states to cancel the uncertainties of the form factors, which could possibly be tested in the near future. |
2301.11814 | M. Cristina Volpe | M. Cristina Volpe | Neutrinos from dense environments : Flavor mechanisms, theoretical
approaches, observations, and new directions | 58 pages, text and References added, minor corrections | null | null | null | hep-ph astro-ph.SR hep-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Neutrino masses and mixings produce vacuum oscillations, an established
quantum mechanical phenomenon. In matter, the Mikheev-Smirnov-Wolfenstein
effect, due to neutrino interactions with the background particles, triggers
resonant flavor modification. In dense environments, such as core-collapse
supernovae or compact mergers, sizable neutrino-neutrino interactions, shock
waves and turbulence impact the neutrino flavor content under a variety of
phenomena. Theoretical approaches of neutrino propagation range from the
mean-field approximation to the full quantum kinetic equations. Intriguing
connections have been uncovered between weakly interacting dense neutrino gases
and other many-body systems and domains, from condensed matter and nuclear
physics to quantum computing. Besides the intrinsic theoretical interest,
establishing how neutrinos change flavor contributes to answer the longstanding
open questions of how massive stars explode and of the r-process sites. It is
also important for future observations of core-collapse supernova neutrinos and
of the diffuse supernova neutrino background that should be discovered in the
foreseeable future.
| [
{
"created": "Fri, 27 Jan 2023 16:07:03 GMT",
"version": "v1"
},
{
"created": "Tue, 23 Jan 2024 14:34:24 GMT",
"version": "v2"
},
{
"created": "Tue, 20 Feb 2024 23:21:15 GMT",
"version": "v3"
}
] | 2024-02-22 | [
[
"Volpe",
"M. Cristina",
""
]
] | Neutrino masses and mixings produce vacuum oscillations, an established quantum mechanical phenomenon. In matter, the Mikheev-Smirnov-Wolfenstein effect, due to neutrino interactions with the background particles, triggers resonant flavor modification. In dense environments, such as core-collapse supernovae or compact mergers, sizable neutrino-neutrino interactions, shock waves and turbulence impact the neutrino flavor content under a variety of phenomena. Theoretical approaches of neutrino propagation range from the mean-field approximation to the full quantum kinetic equations. Intriguing connections have been uncovered between weakly interacting dense neutrino gases and other many-body systems and domains, from condensed matter and nuclear physics to quantum computing. Besides the intrinsic theoretical interest, establishing how neutrinos change flavor contributes to answer the longstanding open questions of how massive stars explode and of the r-process sites. It is also important for future observations of core-collapse supernova neutrinos and of the diffuse supernova neutrino background that should be discovered in the foreseeable future. |
2304.05586 | Sudhakantha Girmohanta | Sudhakantha Girmohanta, Seung J. Lee, Yuichiro Nakai, and Motoo Suzuki | Multi-brane cosmology | 35 pages, 6 figures. v2: matches published version | JHEP 07 (2023) 182 | 10.1007/JHEP07(2023)182 | null | hep-ph astro-ph.CO hep-th | http://creativecommons.org/licenses/by/4.0/ | 5D warped extra dimension models with multiple 3-branes can naturally realize
multiple hierarchical mass scales which are ubiquitous in physics beyond the
Standard Model. We discuss cosmological consequences of such multi-brane models
with stabilized radions. It is confirmed that for temperatures below the scale
of the IR brane at the end of the extra dimension, we recover the ordinary
expansion of the Universe, with the Hubble expansion rate determined by sum of
the physical energy densities on all 3-branes where they are localized. In
addition, we explore the cosmology for temperatures above the scales of the
intermediate and IR branes where the Universe is described by a spacetime with
the 3-branes replaced by an event horizon. As the temperature of the Universe
cools down, phase transitions are expected to take place, and the intermediate
and IR branes come out from behind the event horizon. The Goldberger-Wise
mechanism for radion stabilization has a well-known problem of having a
supercooled phase transition, which typically does not get completed in time.
This problem is even more severe when an intermediate brane is introduced,
whose scale is well above TeV, as the corresponding Hubble rate is much larger.
We circumvent the problem by employing an alternative mechanism for radion
stabilization with dark Yang-Mills fields, which prevents a long supercooling
epoch, but still allows the strong first order phase transitions. As a result,
the phase transitions in our multi-brane Universe predict a stochastic
gravitational wave background with a unique multi-peak signature, which is
within the sensitivity reach of future space-based gravitational wave
observers. We also show that there are $N-1$ radions for an $N$ 3-brane set-up,
unlike a recent claim that there exists only one radion.
| [
{
"created": "Wed, 12 Apr 2023 03:13:42 GMT",
"version": "v1"
},
{
"created": "Tue, 25 Jul 2023 03:26:26 GMT",
"version": "v2"
}
] | 2023-07-26 | [
[
"Girmohanta",
"Sudhakantha",
""
],
[
"Lee",
"Seung J.",
""
],
[
"Nakai",
"Yuichiro",
""
],
[
"Suzuki",
"Motoo",
""
]
] | 5D warped extra dimension models with multiple 3-branes can naturally realize multiple hierarchical mass scales which are ubiquitous in physics beyond the Standard Model. We discuss cosmological consequences of such multi-brane models with stabilized radions. It is confirmed that for temperatures below the scale of the IR brane at the end of the extra dimension, we recover the ordinary expansion of the Universe, with the Hubble expansion rate determined by sum of the physical energy densities on all 3-branes where they are localized. In addition, we explore the cosmology for temperatures above the scales of the intermediate and IR branes where the Universe is described by a spacetime with the 3-branes replaced by an event horizon. As the temperature of the Universe cools down, phase transitions are expected to take place, and the intermediate and IR branes come out from behind the event horizon. The Goldberger-Wise mechanism for radion stabilization has a well-known problem of having a supercooled phase transition, which typically does not get completed in time. This problem is even more severe when an intermediate brane is introduced, whose scale is well above TeV, as the corresponding Hubble rate is much larger. We circumvent the problem by employing an alternative mechanism for radion stabilization with dark Yang-Mills fields, which prevents a long supercooling epoch, but still allows the strong first order phase transitions. As a result, the phase transitions in our multi-brane Universe predict a stochastic gravitational wave background with a unique multi-peak signature, which is within the sensitivity reach of future space-based gravitational wave observers. We also show that there are $N-1$ radions for an $N$ 3-brane set-up, unlike a recent claim that there exists only one radion. |
1912.04697 | Xiu-Lei Ren | X.-L. Ren, B. B. Malabarba, L.-S. Geng, K. P. Khemchandani, and A.
Martinez Torres | Heavy $K^*(4307)$ meson with hidden charm | Proceeding Hadron 2019, Guilin, China, 16-21 August 2019 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We report on a robust prediction of heavy $K^*$ meson by solving the Faddeev
equations with fixed-center approximation for the three-body $KD\bar{D}^*$
system. As the excited Kaon state, $K^*$ is an exotic hidden charm meson with
$M-i\Gamma/2=4307\pm2-i9\pm2$ MeV and $I(J^P)=1/2(1^-)$. We further performed
the evaluation of the decay width of $K^*(4307)$ to the open two-body channels.
We expect that the above findings inspire an experimental investigation of this
exotic $K^*$ meson and to study the so far unexplored heavy strange meson
sector.
| [
{
"created": "Tue, 10 Dec 2019 14:13:54 GMT",
"version": "v1"
}
] | 2019-12-11 | [
[
"Ren",
"X. -L.",
""
],
[
"Malabarba",
"B. B.",
""
],
[
"Geng",
"L. -S.",
""
],
[
"Khemchandani",
"K. P.",
""
],
[
"Torres",
"A. Martinez",
""
]
] | We report on a robust prediction of heavy $K^*$ meson by solving the Faddeev equations with fixed-center approximation for the three-body $KD\bar{D}^*$ system. As the excited Kaon state, $K^*$ is an exotic hidden charm meson with $M-i\Gamma/2=4307\pm2-i9\pm2$ MeV and $I(J^P)=1/2(1^-)$. We further performed the evaluation of the decay width of $K^*(4307)$ to the open two-body channels. We expect that the above findings inspire an experimental investigation of this exotic $K^*$ meson and to study the so far unexplored heavy strange meson sector. |
1007.5313 | Giulia Zanderighi | Tom Melia, Kirill Melnikov, Raoul Rontsch, Giulia Zanderighi | Next-to-leading order QCD predictions for W+W+jj production at the LHC | 15 pages, 5 (lovely) figures, v3 accepted for publication in JHEP,
corrects tables in appendix | JHEP 1012:053,2010 | 10.1007/JHEP12(2010)053 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Because the LHC is a proton-proton collider, sizable production of two
positively charged W-bosons in association with two jets is possible. This
process leads to a distinct signature of same sign high-pt leptons, missing
energy and jets. We compute the NLO QCD corrections to the QCD-mediated part of
pp -> W+W+jj. These corrections reduce the dependence of the production
cross-section on the renormalization and factorization scale to about +- 10
percent. We find that a large number of W+W+jj events contain a relatively hard
third jet. The presence of this jet should help to either pick up the W+W+jj
signal or to reject it as an unwanted background.
| [
{
"created": "Thu, 29 Jul 2010 20:00:24 GMT",
"version": "v1"
},
{
"created": "Sun, 6 Mar 2011 07:18:44 GMT",
"version": "v2"
},
{
"created": "Thu, 26 May 2011 10:28:21 GMT",
"version": "v3"
}
] | 2011-05-27 | [
[
"Melia",
"Tom",
""
],
[
"Melnikov",
"Kirill",
""
],
[
"Rontsch",
"Raoul",
""
],
[
"Zanderighi",
"Giulia",
""
]
] | Because the LHC is a proton-proton collider, sizable production of two positively charged W-bosons in association with two jets is possible. This process leads to a distinct signature of same sign high-pt leptons, missing energy and jets. We compute the NLO QCD corrections to the QCD-mediated part of pp -> W+W+jj. These corrections reduce the dependence of the production cross-section on the renormalization and factorization scale to about +- 10 percent. We find that a large number of W+W+jj events contain a relatively hard third jet. The presence of this jet should help to either pick up the W+W+jj signal or to reject it as an unwanted background. |
1903.10253 | Luciano Maiani prof | L. Maiani, A. D. Polosa, V. Riquer | The Hydrogen Bond of QCD | 5 pages, 3 figures, comments and references added. Table 1 extended | Phys. Rev. D 100, 014002 (2019) | 10.1103/PhysRevD.100.014002 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Using the Born-Oppenheimer approximation, we show that exotic resonances, X
and Z, may emerge as QCD molecular objects made of colored two-quark lumps,
states with heavy-light diquarks spatially separated from antidiquarks. With
the same method we confirm that doubly heavy tetraquarks are stable against
strong decays. Tetraquarks described here provide a new picture of exotic
hadrons, as formed by the QCD analog of the hydrogen bond of molecular physics.
| [
{
"created": "Mon, 25 Mar 2019 11:48:44 GMT",
"version": "v1"
},
{
"created": "Fri, 17 May 2019 14:08:24 GMT",
"version": "v2"
}
] | 2019-07-10 | [
[
"Maiani",
"L.",
""
],
[
"Polosa",
"A. D.",
""
],
[
"Riquer",
"V.",
""
]
] | Using the Born-Oppenheimer approximation, we show that exotic resonances, X and Z, may emerge as QCD molecular objects made of colored two-quark lumps, states with heavy-light diquarks spatially separated from antidiquarks. With the same method we confirm that doubly heavy tetraquarks are stable against strong decays. Tetraquarks described here provide a new picture of exotic hadrons, as formed by the QCD analog of the hydrogen bond of molecular physics. |
1602.04970 | Aleksey Pivovarov | M.K. Volkov and A.A. Pivovarov | The decays $\tau \rightarrow (\eta,\eta') K^{-} \nu_{\tau}$ in the
extended Nambu-Jona-Lasinio model | 8 pages, 4 figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The decays $\tau \rightarrow (\eta,\eta') K^{-} \nu_{\tau}$ are described in
the framework of the extended Nambu-Jona-Lasinio model. Both full and
differential widths of these decays are calculated. The vector and scalar
channels are considered. In the vector channels, the subprocesses with
intermediate $K^{*}(892)$ and $K^{*}(1410)$ mesons play the main role. In the
scalar channels, the subprocesses with intermediate $K_{0}^{*}(800)$ and
$K_{0}^{*}(1430)$ mesons are taken into account. Scalar channels play a less
important role in calculation of the full width of the decay $\tau \rightarrow
(\eta,\eta') K^{-} \nu_{\tau}$. The obtained results are in satisfactory
agreement with the experimental data.
| [
{
"created": "Tue, 16 Feb 2016 10:13:16 GMT",
"version": "v1"
},
{
"created": "Wed, 15 Feb 2017 09:08:26 GMT",
"version": "v2"
}
] | 2017-02-16 | [
[
"Volkov",
"M. K.",
""
],
[
"Pivovarov",
"A. A.",
""
]
] | The decays $\tau \rightarrow (\eta,\eta') K^{-} \nu_{\tau}$ are described in the framework of the extended Nambu-Jona-Lasinio model. Both full and differential widths of these decays are calculated. The vector and scalar channels are considered. In the vector channels, the subprocesses with intermediate $K^{*}(892)$ and $K^{*}(1410)$ mesons play the main role. In the scalar channels, the subprocesses with intermediate $K_{0}^{*}(800)$ and $K_{0}^{*}(1430)$ mesons are taken into account. Scalar channels play a less important role in calculation of the full width of the decay $\tau \rightarrow (\eta,\eta') K^{-} \nu_{\tau}$. The obtained results are in satisfactory agreement with the experimental data. |
1503.03966 | Antonio Palazzo | Antonio Palazzo | Consistent analysis of the $\nu_\mu \to \nu_e$ sterile neutrinos
searches of ICARUS and OPERA | 5 pages, 5 figures; references updated; to appear in PRD as a Rapid
Communication | null | 10.1103/PhysRevD.91.091301 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The two long-baseline experiments ICARUS and OPERA have recently provided
bounds on light ($\sim$ eV) sterile neutrinos exploiting the negative results
of the $\nu_\mu \to \nu_e$ appearance searches. Both collaborations have
performed the data analysis using an effective 2-flavor description. We show
that such a simplified treatment neglects sizable genuine 4-flavor effects,
which are induced by the interference of the new large squared-mass splitting
$\Delta m^2 _{14}$ with the atmospheric one. The inclusion in the data analysis
of such effects weakens the upper bounds on the effective appearance amplitude
$\sin^2 2\theta_{\mu e}$ approximately by a factor of two. In addition, we
evidence that, in a 4-flavor scheme, the flavor oscillations involve also the
$\nu_e$ component of the CNGS beam and can suppress the theoretical expectation
of the background in a substantial way. The inclusion in the data analysis of
the $\nu_e$ disappearance effects leads to a further weakening of the upper
bounds on $\sin^2 2\theta_{\mu e}$, which overall are relaxed by a factor of
three with respect to those obtained in the effective 2-flavor description.
| [
{
"created": "Fri, 13 Mar 2015 07:08:59 GMT",
"version": "v1"
},
{
"created": "Tue, 24 Mar 2015 13:23:15 GMT",
"version": "v2"
},
{
"created": "Wed, 6 May 2015 10:19:41 GMT",
"version": "v3"
}
] | 2015-06-11 | [
[
"Palazzo",
"Antonio",
""
]
] | The two long-baseline experiments ICARUS and OPERA have recently provided bounds on light ($\sim$ eV) sterile neutrinos exploiting the negative results of the $\nu_\mu \to \nu_e$ appearance searches. Both collaborations have performed the data analysis using an effective 2-flavor description. We show that such a simplified treatment neglects sizable genuine 4-flavor effects, which are induced by the interference of the new large squared-mass splitting $\Delta m^2 _{14}$ with the atmospheric one. The inclusion in the data analysis of such effects weakens the upper bounds on the effective appearance amplitude $\sin^2 2\theta_{\mu e}$ approximately by a factor of two. In addition, we evidence that, in a 4-flavor scheme, the flavor oscillations involve also the $\nu_e$ component of the CNGS beam and can suppress the theoretical expectation of the background in a substantial way. The inclusion in the data analysis of the $\nu_e$ disappearance effects leads to a further weakening of the upper bounds on $\sin^2 2\theta_{\mu e}$, which overall are relaxed by a factor of three with respect to those obtained in the effective 2-flavor description. |
1010.4187 | S. Weinzierl | Sebastian Becker, Christian Reuschle and Stefan Weinzierl | Numerical NLO QCD calculations | 62 pages, version to be published | JHEP 1012:013,2010 | 10.1007/JHEP12(2010)013 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present an algorithm for the numerical calculation of one-loop QCD
amplitudes. The algorithm consists of subtraction terms, approximating the
soft, collinear and ultraviolet divergences of one-loop amplitudes and a method
to deform the integration contour for the loop integration into the complex
space. The algorithm is formulated at the amplitude level and does not rely on
Feynman graphs. Therefore all required ingredients can be calculated
efficiently using recurrence relations. The algorithm applies to massless
partons as well as to massive partons.
| [
{
"created": "Wed, 20 Oct 2010 13:00:31 GMT",
"version": "v1"
},
{
"created": "Mon, 22 Nov 2010 12:37:44 GMT",
"version": "v2"
}
] | 2010-12-09 | [
[
"Becker",
"Sebastian",
""
],
[
"Reuschle",
"Christian",
""
],
[
"Weinzierl",
"Stefan",
""
]
] | We present an algorithm for the numerical calculation of one-loop QCD amplitudes. The algorithm consists of subtraction terms, approximating the soft, collinear and ultraviolet divergences of one-loop amplitudes and a method to deform the integration contour for the loop integration into the complex space. The algorithm is formulated at the amplitude level and does not rely on Feynman graphs. Therefore all required ingredients can be calculated efficiently using recurrence relations. The algorithm applies to massless partons as well as to massive partons. |
1908.08811 | Xiaoyun Chen | Xiaoyun Chen | Fully-heavy tetraquarks: $bb\bar{c}\bar{c}$ and $bc\bar{b}\bar{c}$ | arXiv admin note: text overlap with arXiv:1902.00008 | Phys. Rev. D 100, 094009 (2019) | 10.1103/PhysRevD.100.094009 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the framework of a nonrelativistic chiral quark model, we continue to
study the mass spectra of the fully-heavy $bb\bar{c}\bar{c}$ and
$bc\bar{b}\bar{c}$ tetraquarks. In the present calculations, two structures,
meson-meson [$\bar{Q}Q$][$\bar{Q}Q$] and diquark-antidiquark
[$QQ$][$\bar{Q}\bar{Q}$] ($Q$ = $c$ or $b$), and their mixing, along with all
possible color, spin configurations are considered. The calculations suggest
that no bound state can be formed for $bb\bar{c}\bar{c}$ and $bc\bar{b}\bar{c}$
systems. However, resonances are possible because of the color structure.
Several resonances are predicted and their stabilities are checked using the
real scaling method.
| [
{
"created": "Thu, 22 Aug 2019 11:46:18 GMT",
"version": "v1"
},
{
"created": "Wed, 16 Oct 2019 11:35:38 GMT",
"version": "v2"
}
] | 2019-11-20 | [
[
"Chen",
"Xiaoyun",
""
]
] | In the framework of a nonrelativistic chiral quark model, we continue to study the mass spectra of the fully-heavy $bb\bar{c}\bar{c}$ and $bc\bar{b}\bar{c}$ tetraquarks. In the present calculations, two structures, meson-meson [$\bar{Q}Q$][$\bar{Q}Q$] and diquark-antidiquark [$QQ$][$\bar{Q}\bar{Q}$] ($Q$ = $c$ or $b$), and their mixing, along with all possible color, spin configurations are considered. The calculations suggest that no bound state can be formed for $bb\bar{c}\bar{c}$ and $bc\bar{b}\bar{c}$ systems. However, resonances are possible because of the color structure. Several resonances are predicted and their stabilities are checked using the real scaling method. |
1707.00272 | Gennady Kozlov | G. Kozlov | CP and particle correlations under thermal influence | Talk given at Workshop of Particle Correlations and Femtoscopy (XII
WPCF), 12th to 16th of June 2017, Amsterdam, The Netherlands | null | null | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the phase transition of nuclear (baryonic) matter in the model of
one-dimensional random fluctuation walk. The stochastic fields (forces)
influence intrinsic to Bose-Einstein correlations between two identical
particles is a particular ingridient of the model. The solution in terms of the
characteristic functional equation contains the regular (homogenious) and the
singular non-analytical (non-homogenious) parts for baryonic matter (BM) and
anomaly matter (AM), respectively. The conditions to phase transition from BM
to AM are found.
| [
{
"created": "Sun, 2 Jul 2017 10:00:15 GMT",
"version": "v1"
}
] | 2017-07-04 | [
[
"Kozlov",
"G.",
""
]
] | We study the phase transition of nuclear (baryonic) matter in the model of one-dimensional random fluctuation walk. The stochastic fields (forces) influence intrinsic to Bose-Einstein correlations between two identical particles is a particular ingridient of the model. The solution in terms of the characteristic functional equation contains the regular (homogenious) and the singular non-analytical (non-homogenious) parts for baryonic matter (BM) and anomaly matter (AM), respectively. The conditions to phase transition from BM to AM are found. |
1908.06986 | Hongwan Liu | Hongwan Liu, Nadav Joseph Outmezguine, Diego Redigolo and Tomer
Volansky | Reviving Millicharged Dark Matter for 21-cm Cosmology | 11 pages + appendices, 7 figures | Phys. Rev. D 100, 123011 (2019) | 10.1103/PhysRevD.100.123011 | MIT-CTP/5126 | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The existence of millicharged dark matter (mDM) can leave a measurable
imprint on 21-cm cosmology through mDM-baryon scattering. However, the minimal
scenario is severely constrained by existing cosmological bounds on both the
fraction of dark matter that can be millicharged and the mass of mDM particles.
We point out that introducing a long-range force between a millicharged
subcomponent of dark matter and the dominant cold dark matter (CDM) component
leads to efficient cooling of baryons in the early universe, while also
significantly extending the range of viable mDM masses. Such a scenario can
explain the anomalous absorption signal in the sky-averaged 21-cm spectrum
observed by EDGES, and leads to a number of testable predictions for the
properties of the dark sector. The mDM mass can then lie between 10 MeV and a
few hundreds of GeVs, and its scattering cross section with baryons lies within
an unconstrained window of parameter space above direct detection limits and
below current bounds from colliders. In this allowed region, mDM can make up as
little as $10^{-8}$ of the total dark matter energy density. The CDM mass
ranges from 10 MeV to a few GeVs, and has an interaction cross section with the
Standard Model that is induced by a loop of mDM particles. This cross section
is generically within reach of near-future low-threshold direct detection
experiments.
| [
{
"created": "Mon, 19 Aug 2019 18:00:01 GMT",
"version": "v1"
}
] | 2019-12-25 | [
[
"Liu",
"Hongwan",
""
],
[
"Outmezguine",
"Nadav Joseph",
""
],
[
"Redigolo",
"Diego",
""
],
[
"Volansky",
"Tomer",
""
]
] | The existence of millicharged dark matter (mDM) can leave a measurable imprint on 21-cm cosmology through mDM-baryon scattering. However, the minimal scenario is severely constrained by existing cosmological bounds on both the fraction of dark matter that can be millicharged and the mass of mDM particles. We point out that introducing a long-range force between a millicharged subcomponent of dark matter and the dominant cold dark matter (CDM) component leads to efficient cooling of baryons in the early universe, while also significantly extending the range of viable mDM masses. Such a scenario can explain the anomalous absorption signal in the sky-averaged 21-cm spectrum observed by EDGES, and leads to a number of testable predictions for the properties of the dark sector. The mDM mass can then lie between 10 MeV and a few hundreds of GeVs, and its scattering cross section with baryons lies within an unconstrained window of parameter space above direct detection limits and below current bounds from colliders. In this allowed region, mDM can make up as little as $10^{-8}$ of the total dark matter energy density. The CDM mass ranges from 10 MeV to a few GeVs, and has an interaction cross section with the Standard Model that is induced by a loop of mDM particles. This cross section is generically within reach of near-future low-threshold direct detection experiments. |
1401.1827 | Maxim Perelstein | Andrey Katz and Maxim Perelstein | Higgs Couplings and Electroweak Phase Transition | 27 pages, 6 figures. v2: typos fixed, some clarifications added,
results and conclusions unchanged | null | 10.1007/JHEP07(2014)108 | null | hep-ph astro-ph.CO hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We argue that extensions of the Standard Model (SM) with a strongly
first-order electroweak phase transition generically predict significant
deviations of the Higgs couplings to gluons, photons, and Z bosons from their
SM values. Precise experimental measurements of the Higgs couplings at the LHC
and at the proposed next-generation facilities will allow for a robust test of
the phase transition dynamics. To illustrate this point, in this paper we focus
on the scenario in which loops of a new scalar field are responsible for the
first-order phase transition, and study a selection of benchmark models with
various SM gauge quantum numbers of the new scalar. We find that the current
LHC measurement of the Higgs coupling to gluons already excludes the
possibility of a first-order phase transition induced by a scalar in a sextet,
or larger, representation of the SU(3)_c. Future LHC experiments (including
HL-LHC) will be able to definitively probe the case when the new scalar is a
color triplet. If the new scalar is not colored, an electron-positron Higgs
factory, such as the proposed ILC or TLEP, would be required to test the nature
of the phase transition. The extremely precise measurement of the
Higgsstrahlung cross section possible at such machines will allow for a
comprehensive and definitive probe of the possibility of a first-order
electroweak phase transition in all models we considered, including the case
when the new scalar is a pure gauge singlet.
| [
{
"created": "Wed, 8 Jan 2014 21:04:18 GMT",
"version": "v1"
},
{
"created": "Mon, 14 Jul 2014 19:52:34 GMT",
"version": "v2"
}
] | 2015-06-18 | [
[
"Katz",
"Andrey",
""
],
[
"Perelstein",
"Maxim",
""
]
] | We argue that extensions of the Standard Model (SM) with a strongly first-order electroweak phase transition generically predict significant deviations of the Higgs couplings to gluons, photons, and Z bosons from their SM values. Precise experimental measurements of the Higgs couplings at the LHC and at the proposed next-generation facilities will allow for a robust test of the phase transition dynamics. To illustrate this point, in this paper we focus on the scenario in which loops of a new scalar field are responsible for the first-order phase transition, and study a selection of benchmark models with various SM gauge quantum numbers of the new scalar. We find that the current LHC measurement of the Higgs coupling to gluons already excludes the possibility of a first-order phase transition induced by a scalar in a sextet, or larger, representation of the SU(3)_c. Future LHC experiments (including HL-LHC) will be able to definitively probe the case when the new scalar is a color triplet. If the new scalar is not colored, an electron-positron Higgs factory, such as the proposed ILC or TLEP, would be required to test the nature of the phase transition. The extremely precise measurement of the Higgsstrahlung cross section possible at such machines will allow for a comprehensive and definitive probe of the possibility of a first-order electroweak phase transition in all models we considered, including the case when the new scalar is a pure gauge singlet. |
1810.04441 | Pouya Bakhti | Pouya Bakhti, Yasaman Farzan, Meshkat Rajaee | Secret interactions of neutrinos with light gauge boson at the DUNE near
detector | 11 pages, 6 figures | Phys. Rev. D 99, 055019 (2019) | 10.1103/PhysRevD.99.055019 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Secret interactions of neutrinos with light new gauge bosons, $Z^\prime$, can
lead to a rich phenomenology in supernova explosion as well as in the early
Universe. This interaction can also lead to new decay modes for charged mesons,
$\pi^+ (K^+) \to e^+ \nu Z'$, and subsequently to $Z'\to \nu \bar{\nu}$. After
demonstrating that such an interaction can be accommodated within viable
electroweak symmetric models, we study how the near detector (ND) of DUNE can
probe this scenario. We also discuss how the DUNE ND can make it possible to
reconstruct the flavor structure of the $Z^\prime$ coupling to neutrinos.
| [
{
"created": "Wed, 10 Oct 2018 10:02:07 GMT",
"version": "v1"
},
{
"created": "Fri, 5 Apr 2019 11:57:03 GMT",
"version": "v2"
}
] | 2019-04-08 | [
[
"Bakhti",
"Pouya",
""
],
[
"Farzan",
"Yasaman",
""
],
[
"Rajaee",
"Meshkat",
""
]
] | Secret interactions of neutrinos with light new gauge bosons, $Z^\prime$, can lead to a rich phenomenology in supernova explosion as well as in the early Universe. This interaction can also lead to new decay modes for charged mesons, $\pi^+ (K^+) \to e^+ \nu Z'$, and subsequently to $Z'\to \nu \bar{\nu}$. After demonstrating that such an interaction can be accommodated within viable electroweak symmetric models, we study how the near detector (ND) of DUNE can probe this scenario. We also discuss how the DUNE ND can make it possible to reconstruct the flavor structure of the $Z^\prime$ coupling to neutrinos. |
1407.0378 | Edgar Perez | Edgar Perez, Guy Paic, Antonio Ortiz, Eleazar Cuautle | Study of the PYTHIA $\Delta\eta\Delta\phi$ correlation as a function of
multiplicity and transverse sphericity in proton-proton collisions at 7 TeV | 6 pages, 4 figures | Journal of Physics: Conf. Ser. 578 012005, 2015 | 10.1088/1742-6596/578/1/012005 | null | hep-ph nucl-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The study and understanding of the details of proton-proton collisions is
important since they are the benchmark for the comparison with heavy ion
results. In the present work we have studied the $\Delta\eta\Delta\phi$
correlations as a function of the event multiplicity and transverse sphericity
in pp collisions at $\sqrt{s}$ = 7 TeV using PYTHIA 8.180. The results show
large variation in the shape of the correlation as a function of the sphericity
and multiplicity indicating the importance of slicing the data in bins of both
observables to better understand the complexity of the interactions. Motivated
by the radial flow patterns originated by color reconnection (CR), results with
and without CR together with dihadron correlations are discussed.
| [
{
"created": "Tue, 1 Jul 2014 19:48:10 GMT",
"version": "v1"
}
] | 2015-01-29 | [
[
"Perez",
"Edgar",
""
],
[
"Paic",
"Guy",
""
],
[
"Ortiz",
"Antonio",
""
],
[
"Cuautle",
"Eleazar",
""
]
] | The study and understanding of the details of proton-proton collisions is important since they are the benchmark for the comparison with heavy ion results. In the present work we have studied the $\Delta\eta\Delta\phi$ correlations as a function of the event multiplicity and transverse sphericity in pp collisions at $\sqrt{s}$ = 7 TeV using PYTHIA 8.180. The results show large variation in the shape of the correlation as a function of the sphericity and multiplicity indicating the importance of slicing the data in bins of both observables to better understand the complexity of the interactions. Motivated by the radial flow patterns originated by color reconnection (CR), results with and without CR together with dihadron correlations are discussed. |
hep-ph/0312135 | Siannah Penaranda | A. M. Curiel, M. J. Herrero, W. Hollik, F. Merz and S. Penaranda | SUSY-electroweak one-loop contributions to Flavour-Changing Higgs-Boson
Decays | LaTeX, 25 pages, 12 figures. Text improved and References added.
Version to appear in Phys.Rev.D | Phys.Rev. D69 (2004) 075009 | 10.1103/PhysRevD.69.075009 | MPP-2003-134, FTUAM-03-23, IFT-UAM/CSIC-03-52 | hep-ph | null | The SUSY-EW one-loop quantum contributions to flavour-changing MSSM
Higgs-boson decays into $b \bar s$ and $s \bar b$ are computed and discussed.
We use the full diagrammatic approach that is valid for all $\tan \beta$ values
and do not rely on the mass-insertion approximation for the characteristic
flavour-changing parameter. We analyze in full detail the dependence of these
flavour-changing partial widths on all the relevant MSSM parameters and also
study the non-decoupling behaviour of these widths with the SUSY mass
parameters. We find that these contributions are sizable as compared to the SM
ones, and together with the SUSY-QCD contributions they can be very efficient
as an indirect method in the future search for Supersymmetry.
| [
{
"created": "Wed, 10 Dec 2003 13:17:13 GMT",
"version": "v1"
},
{
"created": "Wed, 11 Feb 2004 16:21:08 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Curiel",
"A. M.",
""
],
[
"Herrero",
"M. J.",
""
],
[
"Hollik",
"W.",
""
],
[
"Merz",
"F.",
""
],
[
"Penaranda",
"S.",
""
]
] | The SUSY-EW one-loop quantum contributions to flavour-changing MSSM Higgs-boson decays into $b \bar s$ and $s \bar b$ are computed and discussed. We use the full diagrammatic approach that is valid for all $\tan \beta$ values and do not rely on the mass-insertion approximation for the characteristic flavour-changing parameter. We analyze in full detail the dependence of these flavour-changing partial widths on all the relevant MSSM parameters and also study the non-decoupling behaviour of these widths with the SUSY mass parameters. We find that these contributions are sizable as compared to the SM ones, and together with the SUSY-QCD contributions they can be very efficient as an indirect method in the future search for Supersymmetry. |
hep-ph/0308296 | Werner Bernreuther | Werner Bernreuther, Michael Fuecker and Yoshiaki Umeda | Semileptonic decays of polarised top quarks: V + A admixture and QCD
corrections | 7 pages, 2 figures, Latex | Phys.Lett. B582 (2004) 32-38 | 10.1016/j.physletb.2003.12.010 | PITHA 03/08 | hep-ph | null | The semileptonic decays of polarised top quarks are analysed for a general
chirality-conserving tbW vertex. We calculate double differential distributions
for the charged lepton and the neutrino to order \alpha_s in the QCD coupling.
We present these QCD corrections in terms of compact parameterisations that
should be useful for the future investigation of the structure of the top decay
vertex on the basis of large data samples.
| [
{
"created": "Thu, 28 Aug 2003 11:49:17 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Bernreuther",
"Werner",
""
],
[
"Fuecker",
"Michael",
""
],
[
"Umeda",
"Yoshiaki",
""
]
] | The semileptonic decays of polarised top quarks are analysed for a general chirality-conserving tbW vertex. We calculate double differential distributions for the charged lepton and the neutrino to order \alpha_s in the QCD coupling. We present these QCD corrections in terms of compact parameterisations that should be useful for the future investigation of the structure of the top decay vertex on the basis of large data samples. |
hep-ph/9206232 | null | Robert H. Brandenberger (Brown), Anne-Christine Davis (DAMTP,
Cambridge), Andrew M. Matheson (Brown) and Mark Trodden (Cambridge) | Superconducting Cosmc Strings and Primordial Magnetic Fields | BROWN-HET-830, 14 pages, use phyzzx | Phys.Lett. B293 (1992) 287-293 | 10.1016/0370-2693(92)90885-8 | null | hep-ph astro-ph | null | We consider grand unified theories with superconducting cosmic strings and
which admit the mechanism for generating primordial magnetic fields recently
discussed by Vachaspati. We show that these models are severely constrained by
cosmological arguments. Quite generically, either stable springs or vortons
will form. Provided the mass per unit length of the strings is sufficiently
large, these stable configurations will overclose the Universe.
| [
{
"created": "Thu, 18 Jun 1992 06:49:44 GMT",
"version": "v1"
}
] | 2009-10-22 | [
[
"Brandenberger",
"Robert H.",
"",
"Brown"
],
[
"Davis",
"Anne-Christine",
"",
"DAMTP,\n Cambridge"
],
[
"Matheson",
"Andrew M.",
"",
"Brown"
],
[
"Trodden",
"Mark",
"",
"Cambridge"
]
] | We consider grand unified theories with superconducting cosmic strings and which admit the mechanism for generating primordial magnetic fields recently discussed by Vachaspati. We show that these models are severely constrained by cosmological arguments. Quite generically, either stable springs or vortons will form. Provided the mass per unit length of the strings is sufficiently large, these stable configurations will overclose the Universe. |
hep-ph/0502254 | Arunansu Sil | Qaisar Shafi, Arunansu Sil, Siew-Phang Ng | Hybrid Inflation, Dark Energy And Dark Matter | 11 pages, no figures | Phys.Lett. B620 (2005) 105-110 | 10.1016/j.physletb.2005.06.024 | null | hep-ph | null | It has been suggested that the dark energy density \rho_v ~ 10^{-12} eV^4 in
the universe is associated with a metastable (false) vacuum, while the true
vacuum has a vanishing cosmological constant. By including supergravity
corrections we show how this is naturally realized in realistic supersymmetric
hybrid inflation models. With a fundamental supersymmetry breaking scale ~ TeV,
the LSP is not a suitable candidate for cold dark matter. We consider axion
physics to overcome this and simultaneously provide a resolution of the MSSM
\mu problem.
| [
{
"created": "Mon, 28 Feb 2005 20:18:44 GMT",
"version": "v1"
}
] | 2009-11-11 | [
[
"Shafi",
"Qaisar",
""
],
[
"Sil",
"Arunansu",
""
],
[
"Ng",
"Siew-Phang",
""
]
] | It has been suggested that the dark energy density \rho_v ~ 10^{-12} eV^4 in the universe is associated with a metastable (false) vacuum, while the true vacuum has a vanishing cosmological constant. By including supergravity corrections we show how this is naturally realized in realistic supersymmetric hybrid inflation models. With a fundamental supersymmetry breaking scale ~ TeV, the LSP is not a suitable candidate for cold dark matter. We consider axion physics to overcome this and simultaneously provide a resolution of the MSSM \mu problem. |
2404.13962 | Zhun Lu | Xiaoyan Luan and Zhun Lu | Chiral-odd generalized parton distributions of sea quarks at $\xi=0$ in
the light-cone quark model | 13 pages, 8 figures | null | null | null | hep-ph | http://creativecommons.org/licenses/by-nc-sa/4.0/ | We study the chiral-odd generalized parton distributions (GPDs) of the
$\bar{u}$ and $\bar{d}$ quarks inside the proton at zero skewness using the
overlap representation within the light cone formalism. Using the light cone
wave functions (LCWFs) of the proton obtained from the baryon-meson fluctuation
model in terms of the $|q\bar{q}B\rangle$ Fock states, we provide the
expressions of the GPDs $\widetilde{H}^{\bar{q}/P}_T(x,0,t)$,
$H_T^{\bar{q}/P}(x,0,t)$ and $E_T^{\bar{q}/P}(x,0,t)$ for $\bar{q}=\bar{u}$ and
$\bar{d}$. Numerical results for these GPDs in momentum space as well as in
impact parameter space are presented. We further investigate certain
combinations of the chiral-odd GPDs in impact parameter space to the spin-orbit
correlation effect of the sea quarks.
| [
{
"created": "Mon, 22 Apr 2024 08:08:45 GMT",
"version": "v1"
}
] | 2024-04-23 | [
[
"Luan",
"Xiaoyan",
""
],
[
"Lu",
"Zhun",
""
]
] | We study the chiral-odd generalized parton distributions (GPDs) of the $\bar{u}$ and $\bar{d}$ quarks inside the proton at zero skewness using the overlap representation within the light cone formalism. Using the light cone wave functions (LCWFs) of the proton obtained from the baryon-meson fluctuation model in terms of the $|q\bar{q}B\rangle$ Fock states, we provide the expressions of the GPDs $\widetilde{H}^{\bar{q}/P}_T(x,0,t)$, $H_T^{\bar{q}/P}(x,0,t)$ and $E_T^{\bar{q}/P}(x,0,t)$ for $\bar{q}=\bar{u}$ and $\bar{d}$. Numerical results for these GPDs in momentum space as well as in impact parameter space are presented. We further investigate certain combinations of the chiral-odd GPDs in impact parameter space to the spin-orbit correlation effect of the sea quarks. |
1405.2637 | Riccardo Catena | Riccardo Catena and Paolo Gondolo | Global fits of the dark matter-nucleon effective interactions | 32 pages, 11 figures, replaced to match the published version | JCAP 1409 (2014) 09, 045 | 10.1088/1475-7516/2014/09/045 | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The effective theory of isoscalar dark matter-nucleon interactions mediated
by heavy spin-one or spin-zero particles depends on 10 coupling constants
besides the dark matter particle mass. Here we compare this 11-dimensional
effective theory to current observations in a comprehensive statistical
analysis of several direct detection experiments, including the recent LUX,
SuperCDMS and CDMSlite results. From a multidimensional scan with about 3
million likelihood evaluations, we extract the marginalized posterior
probability density functions (a Bayesian approach) and the profile likelihoods
(a frequentist approach), as well as the associated credible regions and
confidence levels, for each coupling constant vs dark matter mass and for each
pair of coupling constants. We compare the Bayesian and frequentist approach in
the light of the currently limited amount of data. We find that current direct
detection data contain sufficient information to simultaneously constrain not
only the familiar spin-independent and spin-dependent interactions, but also
the remaining velocity and momentum dependent couplings predicted by the dark
matter-nucleon effective theory. For current experiments associated with a null
result, we find strong correlations between some pairs of coupling constants.
For experiments that claim a signal (i.e., CoGeNT and DAMA), we find that pairs
of coupling constants produce degenerate results.
| [
{
"created": "Mon, 12 May 2014 06:28:47 GMT",
"version": "v1"
},
{
"created": "Fri, 17 Jul 2015 15:19:02 GMT",
"version": "v2"
}
] | 2015-07-20 | [
[
"Catena",
"Riccardo",
""
],
[
"Gondolo",
"Paolo",
""
]
] | The effective theory of isoscalar dark matter-nucleon interactions mediated by heavy spin-one or spin-zero particles depends on 10 coupling constants besides the dark matter particle mass. Here we compare this 11-dimensional effective theory to current observations in a comprehensive statistical analysis of several direct detection experiments, including the recent LUX, SuperCDMS and CDMSlite results. From a multidimensional scan with about 3 million likelihood evaluations, we extract the marginalized posterior probability density functions (a Bayesian approach) and the profile likelihoods (a frequentist approach), as well as the associated credible regions and confidence levels, for each coupling constant vs dark matter mass and for each pair of coupling constants. We compare the Bayesian and frequentist approach in the light of the currently limited amount of data. We find that current direct detection data contain sufficient information to simultaneously constrain not only the familiar spin-independent and spin-dependent interactions, but also the remaining velocity and momentum dependent couplings predicted by the dark matter-nucleon effective theory. For current experiments associated with a null result, we find strong correlations between some pairs of coupling constants. For experiments that claim a signal (i.e., CoGeNT and DAMA), we find that pairs of coupling constants produce degenerate results. |
2006.02225 | Sabir Ramazanov Dr. | E. Babichev, D. Gorbunov, S. Ramazanov, L. Reverberi | Gravitational reheating and superheavy Dark Matter creation after
inflation with non-minimal coupling | 26 pages, 3 figures; minor changes; matches journal version | JCAP09(2020)059 | 10.1088/1475-7516/2020/09/059 | INR-TH-2020-029 | hep-ph astro-ph.CO hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss the gravitational creation of superheavy particles $\chi$ in an
inflationary scenario with a quartic potential and a non-minimal coupling
between the inflaton $\varphi$ and the Ricci curvature: $\xi \varphi^2 R/2$. We
show that for large constants $\xi >> 1$, there can be abundant production of
particles $\chi$ with masses largely exceeding the inflationary Hubble rate
$H_{infl}$, up to $(a~few) \times \xi H_{infl}$, even if they are conformally
coupled to gravity. We discuss two scenarios involving these gravitationally
produced particles $\chi$. In the first scenario, the inflaton has only
gravitational interactions with the matter sector and the particles $\chi$
reheat the Universe. In this picture, the inflaton decays only due to the
cosmic expansion, and effectively contributes to dark radiation, which can be
of the observable size. The existing limits on dark radiation lead to an upper
bound on the reheating temperature. In the second scenario, the particles
$\chi$ constitute Dark Matter, if substantially stable. In this case, their
typical masses should be in the ballpark of the Grand Unification scale.
| [
{
"created": "Wed, 3 Jun 2020 12:37:34 GMT",
"version": "v1"
},
{
"created": "Wed, 30 Sep 2020 22:10:30 GMT",
"version": "v2"
}
] | 2020-10-14 | [
[
"Babichev",
"E.",
""
],
[
"Gorbunov",
"D.",
""
],
[
"Ramazanov",
"S.",
""
],
[
"Reverberi",
"L.",
""
]
] | We discuss the gravitational creation of superheavy particles $\chi$ in an inflationary scenario with a quartic potential and a non-minimal coupling between the inflaton $\varphi$ and the Ricci curvature: $\xi \varphi^2 R/2$. We show that for large constants $\xi >> 1$, there can be abundant production of particles $\chi$ with masses largely exceeding the inflationary Hubble rate $H_{infl}$, up to $(a~few) \times \xi H_{infl}$, even if they are conformally coupled to gravity. We discuss two scenarios involving these gravitationally produced particles $\chi$. In the first scenario, the inflaton has only gravitational interactions with the matter sector and the particles $\chi$ reheat the Universe. In this picture, the inflaton decays only due to the cosmic expansion, and effectively contributes to dark radiation, which can be of the observable size. The existing limits on dark radiation lead to an upper bound on the reheating temperature. In the second scenario, the particles $\chi$ constitute Dark Matter, if substantially stable. In this case, their typical masses should be in the ballpark of the Grand Unification scale. |
1002.0103 | Ishikawa Hirohisa | Susumu Furuichi (Department of Physics, Rikkyo University, Toshima
Tokyo 171-8501, Japan), Hirohisa Ishikawa (Department of Economy, Meikai
University, Urayasu Chiba, 279-8550, Japan), Keiji Watanbe (Department of
Physics, Meisei University, Hino Tokyo 191-8506, Japan) | Dispersion Relation for the Nucleon Electromagnetic Form Factors | 16pages 9figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Elastic electromagnetic form factors of nucleons are investigated both for
the time-like and the space-like momentums by using the unsubtracted dispersion
relation with QCD constraints. It is shown that the calculated form factors
reproduce the experimental data reasonably well; they agree with recent
experimental data for the neutron magnetic form factors for the space-like data
obtained by the CLAS collaboration and are compatible with the ratio of the
electric and magnetic form factors for the time-like momentum obtained by the
BABAR collaboration.
| [
{
"created": "Sun, 31 Jan 2010 01:36:48 GMT",
"version": "v1"
}
] | 2010-02-02 | [
[
"Furuichi",
"Susumu",
"",
"Department of Physics, Rikkyo University, Toshima\n Tokyo 171-8501, Japan"
],
[
"Ishikawa",
"Hirohisa",
"",
"Department of Economy, Meikai\n University, Urayasu Chiba, 279-8550, Japan"
],
[
"Watanbe",
"Keiji",
"",
"Department of\n Physics, Meisei University, Hino Tokyo 191-8506, Japan"
]
] | Elastic electromagnetic form factors of nucleons are investigated both for the time-like and the space-like momentums by using the unsubtracted dispersion relation with QCD constraints. It is shown that the calculated form factors reproduce the experimental data reasonably well; they agree with recent experimental data for the neutron magnetic form factors for the space-like data obtained by the CLAS collaboration and are compatible with the ratio of the electric and magnetic form factors for the time-like momentum obtained by the BABAR collaboration. |
hep-ph/9505242 | D. R. T. Jones | I. Jack, D.R.T. Jones and K.L. Roberts | Universality and the sparticle spectrum | 18 pages, tex, six figures in a uuencoded postscript file. Uses
harvmac and epsf; Revised version interprets universality conditions as an
infra--red limit for the evolution of couplings and masses. The low energy
phenomenology is unaffected | Nucl.Phys. B455 (1995) 83-96 | null | LTH 374 | hep-ph | null | We calculate the particle spectrum of the SSM which follows from the
assumption that the commonly assumed universal form of the soft supersymmetry
--breaking terms is invariant under renormalisation. It is argued that this
``strong'' universality might be approached as an infra--red fixed point for
the unified theory above the unification scale.
| [
{
"created": "Fri, 5 May 1995 14:54:32 GMT",
"version": "v1"
},
{
"created": "Tue, 30 May 1995 09:45:59 GMT",
"version": "v2"
}
] | 2008-02-03 | [
[
"Jack",
"I.",
""
],
[
"Jones",
"D. R. T.",
""
],
[
"Roberts",
"K. L.",
""
]
] | We calculate the particle spectrum of the SSM which follows from the assumption that the commonly assumed universal form of the soft supersymmetry --breaking terms is invariant under renormalisation. It is argued that this ``strong'' universality might be approached as an infra--red fixed point for the unified theory above the unification scale. |
1511.00907 | Alexander V. Kuznetsov | A.V. Kuznetsov, D.A. Rumyantsev (Yaroslavl State P.G. Demidov
University, Russia) and V.N. Savin (Yaroslavl Higher Military School of Air
Defence, Russia) | Neutrino processes $\nu \bar\nu \to e^- e^+$ and $\nu \to \nu e^- e^+$
in a strong magnetic field | 4 pages, LaTeX, 1 EPS figure, based on the talk presented by V.N.
Savin at the International Conference on Particle Physics and Astrophysics,
Moscow, MEPhI, October 5-10, 2015, to be submitted to J. Phys.: Conf. Series.
arXiv admin note: substantial text overlap with arXiv:1408.6985 | null | 10.1088/1742-6596/675/3/032019 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The processes of neutrino production of electron-positron pairs, $\nu \bar\nu
\to e^- e^+$ and $\nu \to \nu e^- e^+$, in a magnetic field of arbitrary
strength, where electrons and positrons can be created in the states
corresponding to excited Landau levels, are analysed. The results can be
applied for calculating the efficiency of the electron-positron plasma
production by neutrinos in the conditions of the Kerr black hole accretion disc
considered by experts as the most possible source of a short cosmological gamma
burst.
| [
{
"created": "Tue, 3 Nov 2015 13:44:16 GMT",
"version": "v1"
}
] | 2016-02-17 | [
[
"Kuznetsov",
"A. V.",
"",
"Yaroslavl State P.G. Demidov\n University, Russia"
],
[
"Rumyantsev",
"D. A.",
"",
"Yaroslavl State P.G. Demidov\n University, Russia"
],
[
"Savin",
"V. N.",
"",
"Yaroslavl Higher Military School of Air\n Defence, Russia"
]
] | The processes of neutrino production of electron-positron pairs, $\nu \bar\nu \to e^- e^+$ and $\nu \to \nu e^- e^+$, in a magnetic field of arbitrary strength, where electrons and positrons can be created in the states corresponding to excited Landau levels, are analysed. The results can be applied for calculating the efficiency of the electron-positron plasma production by neutrinos in the conditions of the Kerr black hole accretion disc considered by experts as the most possible source of a short cosmological gamma burst. |
1004.0884 | Daniel Elbio L\'opez-Fogliani | Daniel E. Lopez-Fogliani | The seesaw mechanism in the $\mu \nu$SSM | 7 pages, 1 figure. Talk given at "BUE, CTP International Conference
on Neutrino Physics in the LHC Era", Luxor, Egypt, 15-19 Nov. 2009. | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The $\mu \nu$SSM proposes to use right-handed neutrino supermultiplets in
order to generate the $\mu$ term and neutrino masses simultaneously. We discuss
neutrino physics and the associated electroweak seesaw mechanism in this model.
We show how to obtain, from the neutralino-neutrino mass matrix of the $\mu
\nu$SSM, the effective neutrino mass matrix. In particular we discuss certain
limits of this matrix that clarify the neutrino-sector behavior of the model.
We also show that current data on neutrino masses and mixing angles can easily
be reproduced. These constraints can be fulfilled even with a diagonal neutrino
Yukawa matrix, since this seesaw does not involve only the right-handed
neutrinos but also the MSSM neutralinos. To obtain the correct neutrino angles
turns out to be easy due to the following characteristics of this seesaw:
R-parity is broken and the relevant scale is the electroweak one.
| [
{
"created": "Tue, 6 Apr 2010 16:18:17 GMT",
"version": "v1"
}
] | 2010-04-07 | [
[
"Lopez-Fogliani",
"Daniel E.",
""
]
] | The $\mu \nu$SSM proposes to use right-handed neutrino supermultiplets in order to generate the $\mu$ term and neutrino masses simultaneously. We discuss neutrino physics and the associated electroweak seesaw mechanism in this model. We show how to obtain, from the neutralino-neutrino mass matrix of the $\mu \nu$SSM, the effective neutrino mass matrix. In particular we discuss certain limits of this matrix that clarify the neutrino-sector behavior of the model. We also show that current data on neutrino masses and mixing angles can easily be reproduced. These constraints can be fulfilled even with a diagonal neutrino Yukawa matrix, since this seesaw does not involve only the right-handed neutrinos but also the MSSM neutralinos. To obtain the correct neutrino angles turns out to be easy due to the following characteristics of this seesaw: R-parity is broken and the relevant scale is the electroweak one. |
hep-ph/0012018 | Francesco Vissani | Francesco Vissani (Gran Sasso) | Non-Oscillation Searches of Neutrino Mass in the Age of Oscillations | 3 pages, 1 figure. Matches the version to appear in the Proceedings
of NOW 2000 Workshop | Nucl.Phys.Proc.Suppl. 100 (2001) 273-275 | 10.1016/S0920-5632(01)01454-2 | null | hep-ph | null | We focus on the implications of the oscillations for the shape of nuclear
beta-spectrum (=direct search for nu mass). This is of interest because of the
existing bound, m_(nu_e)<2.2 eV, that could improve by one order of magnitude
with future experiments. We stress important connections with the results of
Liquid Scintillator Neutrino Detector, nu_e disappearance experiments,
supernova neutrinos and neutrinoless double beta decay.
| [
{
"created": "Sat, 2 Dec 2000 12:38:25 GMT",
"version": "v1"
},
{
"created": "Fri, 15 Dec 2000 19:01:14 GMT",
"version": "v2"
}
] | 2009-10-31 | [
[
"Vissani",
"Francesco",
"",
"Gran Sasso"
]
] | We focus on the implications of the oscillations for the shape of nuclear beta-spectrum (=direct search for nu mass). This is of interest because of the existing bound, m_(nu_e)<2.2 eV, that could improve by one order of magnitude with future experiments. We stress important connections with the results of Liquid Scintillator Neutrino Detector, nu_e disappearance experiments, supernova neutrinos and neutrinoless double beta decay. |
2112.13011 | Andreas Windisch | Andreas Windisch, Thomas Gallien, Christopher Schwarzlmueller | A machine learning pipeline for autonomous numerical analytic
continuation of Dyson-Schwinger equations | Proceedings of 'A Virtual Tribute to Quark Confinement and the Hadron
Spectrum', August 2021 | null | 10.1051/epjconf/202225809003 | null | hep-ph cs.LG hep-th | http://creativecommons.org/licenses/by-nc-nd/4.0/ | Dyson-Schwinger equations (DSEs) are a non-perturbative way to express
n-point functions in quantum field theory. Working in Euclidean space and in
Landau gauge, for example, one can study the quark propagator Dyson-Schwinger
equation in the real and complex domain, given that a suitable and tractable
truncation has been found. When aiming for solving these equations in the
complex domain, that is, for complex external momenta, one has to deform the
integration contour of the radial component in the complex plane of the loop
momentum expressed in hyper-spherical coordinates. This has to be done in order
to avoid poles and branch cuts in the integrand of the self-energy loop. Since
the nature of Dyson-Schwinger equations is such, that they have to be solved in
a self-consistent way, one cannot analyze the analytic properties of the
integrand after every iteration step, as this would not be feasible. In these
proceedings, we suggest a machine learning pipeline based on deep learning (DL)
approaches to computer vision (CV), as well as deep reinforcement learning
(DRL), that could solve this problem autonomously by detecting poles and branch
cuts in the numerical integrand after every iteration step and by suggesting
suitable integration contour deformations that avoid these obstructions. We
sketch out a proof of principle for both of these tasks, that is, the pole and
branch cut detection, as well as the contour deformation.
| [
{
"created": "Fri, 24 Dec 2021 09:56:42 GMT",
"version": "v1"
}
] | 2022-02-16 | [
[
"Windisch",
"Andreas",
""
],
[
"Gallien",
"Thomas",
""
],
[
"Schwarzlmueller",
"Christopher",
""
]
] | Dyson-Schwinger equations (DSEs) are a non-perturbative way to express n-point functions in quantum field theory. Working in Euclidean space and in Landau gauge, for example, one can study the quark propagator Dyson-Schwinger equation in the real and complex domain, given that a suitable and tractable truncation has been found. When aiming for solving these equations in the complex domain, that is, for complex external momenta, one has to deform the integration contour of the radial component in the complex plane of the loop momentum expressed in hyper-spherical coordinates. This has to be done in order to avoid poles and branch cuts in the integrand of the self-energy loop. Since the nature of Dyson-Schwinger equations is such, that they have to be solved in a self-consistent way, one cannot analyze the analytic properties of the integrand after every iteration step, as this would not be feasible. In these proceedings, we suggest a machine learning pipeline based on deep learning (DL) approaches to computer vision (CV), as well as deep reinforcement learning (DRL), that could solve this problem autonomously by detecting poles and branch cuts in the numerical integrand after every iteration step and by suggesting suitable integration contour deformations that avoid these obstructions. We sketch out a proof of principle for both of these tasks, that is, the pole and branch cut detection, as well as the contour deformation. |
hep-ph/0304249 | Schierholz | M. G\"ockeler, R. Horsley, D. Pleiter, P.E.L. Rakow, A. Sch\"afer, G.
Schierholz and W. Schroers | Generalized Parton Distributions from Lattice QCD | 11 pages, 4 figures; final version, to be published in Phys. Rev.
Lett | Phys.Rev.Lett.92:042002,2004 | 10.1103/PhysRevLett.92.042002 | DESY 03-051, LU-ITP 2003/006, Edinburgh-2003/04, LTH-573,
MIT-CTP-3365 | hep-ph hep-lat | null | We perform a quenched lattice calculation of the first moment of twist-two
generalized parton distribution functions of the proton, and assess the total
quark (spin and orbital angular momentum) contribution to the spin of the
proton.
| [
{
"created": "Sat, 26 Apr 2003 16:26:01 GMT",
"version": "v1"
},
{
"created": "Mon, 29 Dec 2003 14:15:31 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Göckeler",
"M.",
""
],
[
"Horsley",
"R.",
""
],
[
"Pleiter",
"D.",
""
],
[
"Rakow",
"P. E. L.",
""
],
[
"Schäfer",
"A.",
""
],
[
"Schierholz",
"G.",
""
],
[
"Schroers",
"W.",
""
]
] | We perform a quenched lattice calculation of the first moment of twist-two generalized parton distribution functions of the proton, and assess the total quark (spin and orbital angular momentum) contribution to the spin of the proton. |
hep-ph/9910513 | Stefan Hesselbach | S. Hesselbach and H. Fraas | Selectron Mass Effects in Neutralino Production | 5 pages, LaTeX, 8 eps figures, uses appolb.cls which is included;
talk presented at the XXIII School of Theoretical Physics, Ustron, Poland,
September 15-22, 1999 | Acta Phys.Polon.B30:3423-3428,1999 | null | WUE-ITP-99-026 | hep-ph | null | We study the possibility to measure the masses of the selectrons in
neutralino production at an e^+ e^- linear collider with polarized beams. The
cross sections and polarization asymmetries of neutralinos with gaugino
character strongly depend on the masses of the exchanged selectrons. If the
usual GUT relations of the selectron masses in the MSSM are relaxed large
effects are possible especially in the polarization asymmetries. These can be
used to determine the masses of both selectrons.
| [
{
"created": "Wed, 27 Oct 1999 15:41:06 GMT",
"version": "v1"
}
] | 2011-04-15 | [
[
"Hesselbach",
"S.",
""
],
[
"Fraas",
"H.",
""
]
] | We study the possibility to measure the masses of the selectrons in neutralino production at an e^+ e^- linear collider with polarized beams. The cross sections and polarization asymmetries of neutralinos with gaugino character strongly depend on the masses of the exchanged selectrons. If the usual GUT relations of the selectron masses in the MSSM are relaxed large effects are possible especially in the polarization asymmetries. These can be used to determine the masses of both selectrons. |
hep-ph/9503211 | null | D. Schildknecht | A Remark on the $Z^0 \to b\bar b$ Width | 8 pages uuencoded postscript including 2 figures | Phys.Lett. B355 (1995) 325-328 | 10.1016/0370-2693(95)00662-5 | BI-TP 95/09 | hep-ph | null | The $Z^0 \to b\bar b$ width, $\Gamma_b$, is analysed in conjunction with the
total and hadronic $Z^0$ widths, $\Gamma_T$ and $\Gamma_h$. Assuming,
tentatively, that the present 2$\sigma$ discrepancy in $\Gamma_b$ will
substantiate as time goes on, for large values of $m_H$ it will be sufficient
to modify the $Z^0 b \bar b$ vertex only. In contrast, for small values of
$m_H$, the theoretical predictions for both the $Z^0$ width into light quarks
and leptons as well as the $Z^0 \to b\bar b$ vertex will have to be modified.
| [
{
"created": "Thu, 2 Mar 1995 13:57:00 GMT",
"version": "v1"
}
] | 2016-09-01 | [
[
"Schildknecht",
"D.",
""
]
] | The $Z^0 \to b\bar b$ width, $\Gamma_b$, is analysed in conjunction with the total and hadronic $Z^0$ widths, $\Gamma_T$ and $\Gamma_h$. Assuming, tentatively, that the present 2$\sigma$ discrepancy in $\Gamma_b$ will substantiate as time goes on, for large values of $m_H$ it will be sufficient to modify the $Z^0 b \bar b$ vertex only. In contrast, for small values of $m_H$, the theoretical predictions for both the $Z^0$ width into light quarks and leptons as well as the $Z^0 \to b\bar b$ vertex will have to be modified. |
1012.5620 | Zoltan Ligeti | Zoltan Ligeti | Supermodels: Early new physics at the LHC? | 5 pages, 2 figures, talk given at the 35th International Conference
on High Energy Physics (ICHEP 2010), Paris, France, July 22-28, 2010 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate new physics that could be discovered with very little LHC
data, beyond the expected sensitivity of the Tevatron. We construct
"supermodels", for which the LHC sensitivity with 10 pb-1 luminosity is already
greater than that of the Tevatron with 10 fb-1. The simplest supermodels
involve s-channel resonances in the quark-antiquark and especially in the
quark-quark channels. In the latter case, the LHC sensitivity with 0.1 pb-1 can
already be greater than that of the Tevatron with 10 fb-1. We concentrate on
easily visible final states with small standard model backgrounds, and find
that there are simple searches, besides those for Z' states, which could
discover new physics in early LHC data. Many of these are well-suited to test
searches for "conventional" models, often discussed for larger data sets.
| [
{
"created": "Mon, 27 Dec 2010 15:04:47 GMT",
"version": "v1"
}
] | 2010-12-30 | [
[
"Ligeti",
"Zoltan",
""
]
] | We investigate new physics that could be discovered with very little LHC data, beyond the expected sensitivity of the Tevatron. We construct "supermodels", for which the LHC sensitivity with 10 pb-1 luminosity is already greater than that of the Tevatron with 10 fb-1. The simplest supermodels involve s-channel resonances in the quark-antiquark and especially in the quark-quark channels. In the latter case, the LHC sensitivity with 0.1 pb-1 can already be greater than that of the Tevatron with 10 fb-1. We concentrate on easily visible final states with small standard model backgrounds, and find that there are simple searches, besides those for Z' states, which could discover new physics in early LHC data. Many of these are well-suited to test searches for "conventional" models, often discussed for larger data sets. |
hep-ph/0608097 | Vadim Bednyakov | V. A. Bednyakov (JINR, Dubna), F. Simkovic (Comenius University,
Bratislava) | Nuclear spin structure in dark matter search: The finite momentum
transfer limit | 39 pages, 12 figures, a review in revtex4 | Phys.Part.Nucl. 37 (2006) S106-S128 | 10.1134/S1063779606070057 | null | hep-ph | null | Spin-dependent elastic scattering of weakly interacting massive dark matter
particles (WIMP) off nuclei is reviewed. All available, within different
nuclear models, structure functions S(q) for finite momentum transfer (q>0) are
presented. These functions describe the recoil energy dependence of the
differential event rate due to the spin-dependent WIMP-nucleon interactions.
This paper, together with the previous paper ``Nuclear spin structure in dark
matter search: The zero momentum transfer limit'', completes our review of the
nuclear spin structure calculations involved in the problem of direct dark
matter search.
| [
{
"created": "Wed, 9 Aug 2006 10:20:29 GMT",
"version": "v1"
}
] | 2009-11-11 | [
[
"Bednyakov",
"V. A.",
"",
"JINR, Dubna"
],
[
"Simkovic",
"F.",
"",
"Comenius University,\n Bratislava"
]
] | Spin-dependent elastic scattering of weakly interacting massive dark matter particles (WIMP) off nuclei is reviewed. All available, within different nuclear models, structure functions S(q) for finite momentum transfer (q>0) are presented. These functions describe the recoil energy dependence of the differential event rate due to the spin-dependent WIMP-nucleon interactions. This paper, together with the previous paper ``Nuclear spin structure in dark matter search: The zero momentum transfer limit'', completes our review of the nuclear spin structure calculations involved in the problem of direct dark matter search. |
hep-ph/9609310 | Ulrich Nierste | Ulrich Nierste | Phenomenology of epsilon_K in the top era | Talk given at the wokshop on K physics, Orsay, France, 30 May - 4
June 1996, 10 pages, LATEX2e, uses cite,subeqn,epsf,rotate,times. Two typos
corrected. PostScript file now also available via anonymous ftp at
ftp://feynman.t30.physik.tu-muenchen.de/pub/preprints/tum-254-96.ps.gz | null | null | TUM-HEP-254/96 | hep-ph | null | Todays key information on the shape of the unitarity triangle is obtained
from the well-measured quantity epsilon_K characterizing the CP-violation in
|Delta S|=2 transitions. The phenomenological analysis requires the input of
four key quantities: The magnitudes of the CKM elements V_cb and V_ub, the top
quark mass and the non-perturbative parameter B_K. In the recent years all of
them have been determined with increasing precision. In order to keep up with
this progress the |Delta S|=2-hamiltonian had to be obtained in the
next-to-leading order (NLO) of renormalization group improved perturbation
theory. I present the NLO results for the QCD coefficients eta_1 and eta_3,
which have been calculated by Stefan Herrlich and myself, and briefly sketch
some aspects of the calculation. Then I give an update of the Unitarity
Triangle using the summer 1996 data for the input parameters. The results for
the improved Wolfenstein parameters rho-bar and eta-bar and the CKM phase delta
are -0.21 < rho-bar < 0.22, 0.27 < eta-bar < 0.43 and 57 degrees < delta < 122
degrees. The range for the quantity sin(2 beta) entering CP asymmetries in
B-decays is found as 0.46 < sin(2 beta) < 0.79. The given ranges correspond to
one standard deviation in the input parameters. Finally I briefly discuss the
K_L-K_S mass difference.
| [
{
"created": "Tue, 10 Sep 1996 17:47:21 GMT",
"version": "v1"
},
{
"created": "Mon, 16 Sep 1996 18:29:10 GMT",
"version": "v2"
}
] | 2008-02-03 | [
[
"Nierste",
"Ulrich",
""
]
] | Todays key information on the shape of the unitarity triangle is obtained from the well-measured quantity epsilon_K characterizing the CP-violation in |Delta S|=2 transitions. The phenomenological analysis requires the input of four key quantities: The magnitudes of the CKM elements V_cb and V_ub, the top quark mass and the non-perturbative parameter B_K. In the recent years all of them have been determined with increasing precision. In order to keep up with this progress the |Delta S|=2-hamiltonian had to be obtained in the next-to-leading order (NLO) of renormalization group improved perturbation theory. I present the NLO results for the QCD coefficients eta_1 and eta_3, which have been calculated by Stefan Herrlich and myself, and briefly sketch some aspects of the calculation. Then I give an update of the Unitarity Triangle using the summer 1996 data for the input parameters. The results for the improved Wolfenstein parameters rho-bar and eta-bar and the CKM phase delta are -0.21 < rho-bar < 0.22, 0.27 < eta-bar < 0.43 and 57 degrees < delta < 122 degrees. The range for the quantity sin(2 beta) entering CP asymmetries in B-decays is found as 0.46 < sin(2 beta) < 0.79. The given ranges correspond to one standard deviation in the input parameters. Finally I briefly discuss the K_L-K_S mass difference. |
hep-ph/9509358 | null | Laurent Lellouch (CPT, Luminy) | Lattice-Constrained Unitarity Bounds for $\bar B^0 \to \pi^+ l^- \bar
\nu_l$ Decays | LaTeX, 34 pages, and 6 PostScript figures. Version to appear in
Nuclear Physics B. Small changes in the numerical results as well as a few
other minor changes | Nucl.Phys.B479:353-391,1996 | 10.1016/0550-3213(96)00443-9 | CPT-95/P.3236 | hep-ph hep-lat | null | Lattice results, kinematical constraints and QCD dispersion relations are
combined for the first time to derive model-independent bounds for QCD form
factors and corresponding rates. To take into account the error bars on the
lattice results we develop a general formalism which ascribes well-defined
statistical properties to these bounds. We concentrate on $\bar B^0 \to \pi^+
l^- \bar\nu_l$ decays because of the relative simplicity of the analytical
behavior of the relevant polarization functions and because of their immediate
phenomenological relevance. To determine the range of applicability of the
dispersive matching required to obtain the bounds, we have evaluated the
leading perturbative and non-perturbative QCD corrections to the relevant
polarization functions. Despite the lattice results' large error bars and
limited kinematical range, the bounds we obtain appear to favor certain
parametrizations for the form factors over others. The bounds also enable the
determination of $|V_{ub}|$ from the total experimental rate with a theoretical
error ranging from 27% to 37%, depending on the assumptions made. The
techniques developed here are, in fact, quite general and are not limited to
use with lattice results nor to semileptonic $\bar B^0 \to \pi^+ l^- \bar\nu_l$
decays.
| [
{
"created": "Fri, 22 Sep 1995 10:10:45 GMT",
"version": "v1"
},
{
"created": "Sun, 24 Sep 1995 20:30:32 GMT",
"version": "v2"
},
{
"created": "Thu, 28 Sep 1995 01:25:12 GMT",
"version": "v3"
},
{
"created": "Tue, 3 Oct 1995 11:36:26 GMT",
"version": "v4"
},
{
"created": "Sun, 30 Jun 1996 19:53:54 GMT",
"version": "v5"
},
{
"created": "Wed, 25 Sep 1996 14:03:40 GMT",
"version": "v6"
}
] | 2011-05-05 | [
[
"Lellouch",
"Laurent",
"",
"CPT, Luminy"
]
] | Lattice results, kinematical constraints and QCD dispersion relations are combined for the first time to derive model-independent bounds for QCD form factors and corresponding rates. To take into account the error bars on the lattice results we develop a general formalism which ascribes well-defined statistical properties to these bounds. We concentrate on $\bar B^0 \to \pi^+ l^- \bar\nu_l$ decays because of the relative simplicity of the analytical behavior of the relevant polarization functions and because of their immediate phenomenological relevance. To determine the range of applicability of the dispersive matching required to obtain the bounds, we have evaluated the leading perturbative and non-perturbative QCD corrections to the relevant polarization functions. Despite the lattice results' large error bars and limited kinematical range, the bounds we obtain appear to favor certain parametrizations for the form factors over others. The bounds also enable the determination of $|V_{ub}|$ from the total experimental rate with a theoretical error ranging from 27% to 37%, depending on the assumptions made. The techniques developed here are, in fact, quite general and are not limited to use with lattice results nor to semileptonic $\bar B^0 \to \pi^+ l^- \bar\nu_l$ decays. |
hep-ph/0512058 | Matthias Steinhauser | Y. Schroder, M. Steinhauser | Four-Loop Decoupling Relations for the Strong Coupling | 11 pages | JHEP 0601 (2006) 051 | 10.1088/1126-6708/2006/01/051 | BI-TP 2005/44, SFB/CPP-05-70, TTP05-21 | hep-ph | null | We compute the matching relation for the strong coupling constant within the
framework of QCD up to four-loop order. This allows a consistent five-loop
running (once the $\beta$ function is available to this order) taking into
account threshold effects. As a side product we obtain the effective coupling
of a Higgs boson to gluons with five-loop accuracy.
| [
{
"created": "Mon, 5 Dec 2005 10:23:04 GMT",
"version": "v1"
}
] | 2009-11-11 | [
[
"Schroder",
"Y.",
""
],
[
"Steinhauser",
"M.",
""
]
] | We compute the matching relation for the strong coupling constant within the framework of QCD up to four-loop order. This allows a consistent five-loop running (once the $\beta$ function is available to this order) taking into account threshold effects. As a side product we obtain the effective coupling of a Higgs boson to gluons with five-loop accuracy. |
2303.10869 | Wei-Jie Fu | Chuang Huang, Yang-yang Tan, Rui Wen, Shi Yin, Wei-jie Fu | Reconstruction of baryon number distributions | 11 pages, 8 figures, 2 tables | null | null | null | hep-ph nucl-th | http://creativecommons.org/licenses/by/4.0/ | The maximum entropy method (MEM) and the Gaussian process (GP) regression,
which are both well-suited for the treatment of inverse problems, are used to
reconstruct net-baryon number distributions based on a finite number of
cumulants of the distribution. Baryon number distributions across the chiral
phase transition are reconstructed. It is found that with the increase of the
order of cumulants, distribution in the long tails, i.e., far away from the
central number, would become more and more important. We also reconstruct the
distribution function based on the experimentally measured cumulants at the
collision energy $\sqrt{s_{NN}}=7.7$ GeV. Given the sizable error of the
fourth-order cumulant measured in experiments, the calculation of MEM shows
that with the increasing fourth-order cumulant, there is another peak in the
distribution function developed in the region of large baryon number. This
unnaturalness observed in the reconstructed distribution function might in turn
be used to constrain the cumulants measured in experiments.
| [
{
"created": "Mon, 20 Mar 2023 05:08:25 GMT",
"version": "v1"
}
] | 2023-03-21 | [
[
"Huang",
"Chuang",
""
],
[
"Tan",
"Yang-yang",
""
],
[
"Wen",
"Rui",
""
],
[
"Yin",
"Shi",
""
],
[
"Fu",
"Wei-jie",
""
]
] | The maximum entropy method (MEM) and the Gaussian process (GP) regression, which are both well-suited for the treatment of inverse problems, are used to reconstruct net-baryon number distributions based on a finite number of cumulants of the distribution. Baryon number distributions across the chiral phase transition are reconstructed. It is found that with the increase of the order of cumulants, distribution in the long tails, i.e., far away from the central number, would become more and more important. We also reconstruct the distribution function based on the experimentally measured cumulants at the collision energy $\sqrt{s_{NN}}=7.7$ GeV. Given the sizable error of the fourth-order cumulant measured in experiments, the calculation of MEM shows that with the increasing fourth-order cumulant, there is another peak in the distribution function developed in the region of large baryon number. This unnaturalness observed in the reconstructed distribution function might in turn be used to constrain the cumulants measured in experiments. |
hep-ph/9602323 | Patricia Ball | P. Ball, V.M. Braun | The $\rho$ Meson Light-Cone Distribution Amplitudes of Leading Twist
Revisited | 21 pages, latex2e, requires a4wide.sty and epsf.sty, 6 PS figures
included | Phys. Rev. D 54, 2182 (1996) | 10.1103/PhysRevD.54.2182 | CERN-TH/96-12 | hep-ph | null | We give a complete re-analysis of the leading twist quark-antiquark
light-cone distribution amplitudes of longitudinal and transverse $\rho$
mesons. We derive Wandzura-Wilczek type relations between different
distributions and update the coefficients in their conformal expansion using
QCD sum rules including next-to-leading order radiative corrections. We find
that the distribution amplitudes of quarks inside longitudinally and
transversely polarized $\rho$ mesons have a similar shape, which is in
contradiction to previous analyses.
| [
{
"created": "Thu, 15 Feb 1996 23:31:37 GMT",
"version": "v1"
}
] | 2016-08-24 | [
[
"Ball",
"P.",
""
],
[
"Braun",
"V. M.",
""
]
] | We give a complete re-analysis of the leading twist quark-antiquark light-cone distribution amplitudes of longitudinal and transverse $\rho$ mesons. We derive Wandzura-Wilczek type relations between different distributions and update the coefficients in their conformal expansion using QCD sum rules including next-to-leading order radiative corrections. We find that the distribution amplitudes of quarks inside longitudinally and transversely polarized $\rho$ mesons have a similar shape, which is in contradiction to previous analyses. |
hep-ph/0607234 | J. P. Ma | J.P. Ma and Q. Wang | Transverse-Momentum Dependent Factorization for gamma^* pi^0 to gamma | Published version in Phys.Rev.D75:014014,2007 | Phys.Rev.D75:014014,2007 | 10.1103/PhysRevD.75.014014 | null | hep-ph | null | With a consistent definition of transverse-momentum dependent (TMD)
light-cone wave function, we show that the amplitude for the process $\gamma^*
\pi^0 \to\gamma$ can be factorized when the virtuality of the initial photon is
large. In contrast to the collinear factorization in which the amplitude is
factorized as a convolution of the standard light-cone wave function and a hard
part, the TMD factorization yields a convolution of a TMD light-cone wave
function, a soft factor and a hard part. We explicitly show that the TMD
factorization holds at one loop level. It is expected that the factorization
holds beyond one-loop level because the cancelation of soft divergences is on a
diagram-by-diagram basis. We also show that the TMD factorization helps to
resum large logarithms of type $\ln^2x$.
| [
{
"created": "Fri, 21 Jul 2006 02:33:19 GMT",
"version": "v1"
},
{
"created": "Wed, 18 Oct 2006 01:20:23 GMT",
"version": "v2"
},
{
"created": "Tue, 6 Feb 2007 02:40:32 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Ma",
"J. P.",
""
],
[
"Wang",
"Q.",
""
]
] | With a consistent definition of transverse-momentum dependent (TMD) light-cone wave function, we show that the amplitude for the process $\gamma^* \pi^0 \to\gamma$ can be factorized when the virtuality of the initial photon is large. In contrast to the collinear factorization in which the amplitude is factorized as a convolution of the standard light-cone wave function and a hard part, the TMD factorization yields a convolution of a TMD light-cone wave function, a soft factor and a hard part. We explicitly show that the TMD factorization holds at one loop level. It is expected that the factorization holds beyond one-loop level because the cancelation of soft divergences is on a diagram-by-diagram basis. We also show that the TMD factorization helps to resum large logarithms of type $\ln^2x$. |
hep-ph/0307348 | Akira Niegawa | A. Niegawa | Self-energy-part resummed quark and gluon propagators in a
spin-polarized quark matter and generalized Boltzmann equations | 57 pages | Phys.Rev. D68 (2003) 116007 | 10.1103/PhysRevD.68.116007 | OCU-PHYS 202 | hep-ph | null | We construct perturbative frameworks for studying nonequilibrium
spin-polarized quark matter. We employ the closed-time-path formalism and use
the gradient approximation in the derivative expansion. After constructing
self-energy-part resummed quark and gluon propagators, we formulate two kind of
mutually equivalent perturbative frameworks: The first one is formulated on the
basis of the initial-particle distribution function, and the second one is
formulated on the basis of `` physical''-particle distribution function. In the
course of construction of the second framework, the generalized Boltzmann
equations and their relatives {\em directly} come out, which describe the
evolution of the system. The frameworks are relevant to the study of a magnetic
character of quark matters, e.g., possible quark stars.
| [
{
"created": "Tue, 29 Jul 2003 09:39:08 GMT",
"version": "v1"
},
{
"created": "Mon, 1 Dec 2003 06:27:29 GMT",
"version": "v2"
},
{
"created": "Thu, 25 Nov 2004 07:31:59 GMT",
"version": "v3"
}
] | 2009-11-10 | [
[
"Niegawa",
"A.",
""
]
] | We construct perturbative frameworks for studying nonequilibrium spin-polarized quark matter. We employ the closed-time-path formalism and use the gradient approximation in the derivative expansion. After constructing self-energy-part resummed quark and gluon propagators, we formulate two kind of mutually equivalent perturbative frameworks: The first one is formulated on the basis of the initial-particle distribution function, and the second one is formulated on the basis of `` physical''-particle distribution function. In the course of construction of the second framework, the generalized Boltzmann equations and their relatives {\em directly} come out, which describe the evolution of the system. The frameworks are relevant to the study of a magnetic character of quark matters, e.g., possible quark stars. |
2209.10777 | Xu-Dong Huang | Xu-Dong Huang, Xing-Gang Wu, Xu-Chang Zheng, Jiang Yan, Zhi-Fei Wu and
Hong-Hao Ma | Precise determination of the top-quark on-shell mass $M_t$ via its
scale-invariant perturbative relation to the top-quark $\overline{\rm MS}$
mass ${\overline m}_t({\overline m}_t)$ | 15 pages, 2 figures, to be published in Chinese Physics C | Chin. Phys. C 48, 053113 (2024) | 10.1088/1674-1137/ad2dbf | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | It has been shown that the principle of maximum conformality (PMC) provides a
systematic way to solve conventional renormalization scheme and scale
ambiguities. The scale-fixed predictions for physical observables using the PMC
are independent of the choice of renormalization scheme -- a key requirement of
renormalization group invariance. In the paper, we derive new degeneracy
relations based on the renormalization group equations that involve both the
usual $\beta$-function and the quark mass anomalous dimension
$\gamma_m$-function, respectively. These new degeneracy relations lead to an
improved PMC scale-setting procedures, such that the correct magnitudes of the
strong coupling constant and the $\overline{\rm MS}$-running quark mass can be
fixed simultaneously. By using the improved PMC scale-setting procedures, the
renormalization scale dependence of the $\overline{\rm MS}$-on-shell quark mass
relation can be eliminated systematically. Consequently, the top-quark on-shell
(or $\overline{\rm MS}$) mass can be determined without conventional
renormalization scale ambiguity. Taking the top-quark $\overline{\rm MS}$ mass
${\overline m}_t({\overline m}_t)=162.5^{+2.1}_{-1.5}$ GeV as the input, we
obtain $M_t\simeq 172.41^{+2.21}_{-1.57}$ GeV. Here the uncertainties are
combined errors with those also from $\Delta \alpha_s(M_Z)$ and the approximate
uncertainty stemming from the uncalculated five-loop terms predicted through
the Pad\'{e} approximation approach.
| [
{
"created": "Thu, 22 Sep 2022 04:39:59 GMT",
"version": "v1"
},
{
"created": "Sun, 25 Feb 2024 11:02:05 GMT",
"version": "v2"
}
] | 2024-04-11 | [
[
"Huang",
"Xu-Dong",
""
],
[
"Wu",
"Xing-Gang",
""
],
[
"Zheng",
"Xu-Chang",
""
],
[
"Yan",
"Jiang",
""
],
[
"Wu",
"Zhi-Fei",
""
],
[
"Ma",
"Hong-Hao",
""
]
] | It has been shown that the principle of maximum conformality (PMC) provides a systematic way to solve conventional renormalization scheme and scale ambiguities. The scale-fixed predictions for physical observables using the PMC are independent of the choice of renormalization scheme -- a key requirement of renormalization group invariance. In the paper, we derive new degeneracy relations based on the renormalization group equations that involve both the usual $\beta$-function and the quark mass anomalous dimension $\gamma_m$-function, respectively. These new degeneracy relations lead to an improved PMC scale-setting procedures, such that the correct magnitudes of the strong coupling constant and the $\overline{\rm MS}$-running quark mass can be fixed simultaneously. By using the improved PMC scale-setting procedures, the renormalization scale dependence of the $\overline{\rm MS}$-on-shell quark mass relation can be eliminated systematically. Consequently, the top-quark on-shell (or $\overline{\rm MS}$) mass can be determined without conventional renormalization scale ambiguity. Taking the top-quark $\overline{\rm MS}$ mass ${\overline m}_t({\overline m}_t)=162.5^{+2.1}_{-1.5}$ GeV as the input, we obtain $M_t\simeq 172.41^{+2.21}_{-1.57}$ GeV. Here the uncertainties are combined errors with those also from $\Delta \alpha_s(M_Z)$ and the approximate uncertainty stemming from the uncalculated five-loop terms predicted through the Pad\'{e} approximation approach. |
0903.2266 | Stephan Narison | Stephan Narison, (CNRS-IN2P3 & Univ-Montpellier) | 1^{-+} light exotic mesons in QCD | Misprints corrected. Version to appear in Phys. Lett. B 8 pages, 1
table, 7 figures (available with a better resolution) | Phys.Lett.B675:319-325,2009 | 10.1016/j.physletb.2009.04.012 | null | hep-ph hep-ex hep-lat nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We systematically re-examine the extraction of the masses and couplings of
the 1^{-+} hybrid, four-quark and molecule mesons from QCD spectral sum rules
(QSSR). To NLO for the perturbative and power corrections, the hybrid mass is
M_H=1.81(6) GeV and M_H < 2.2(2) GeV from the positivity of the spectral
function. In the same way, but to LO, the four-quark state mass is M_{4q}=
1.70(4) GeV and M_{4q} < 2.4(1) GeV, while the molecule mass is about 1.3(1)
GeV. The observed \pi_1(1400) and \pi_1(1600) might be explained by a
two-component mixing with the set of input masses (1.2-1.3 ; 1.70-1.74) GeV and
with a mixing angle \theta= -(11.7+- 2.2)^0, which slightly favours a
molecule/four-quark mixing, and which eventually suggests that the \pi_1(2015)
is mostly an hybrid meson. Isospin and non-exotic partners of the previous
states and some of their radial excitations are also expected to be found in
the energy region around 2 GeV. Further tests of this phenomenological scenario
are required.
| [
{
"created": "Thu, 12 Mar 2009 20:23:22 GMT",
"version": "v1"
},
{
"created": "Tue, 14 Apr 2009 17:32:12 GMT",
"version": "v2"
}
] | 2014-11-18 | [
[
"Narison",
"Stephan",
""
]
] | We systematically re-examine the extraction of the masses and couplings of the 1^{-+} hybrid, four-quark and molecule mesons from QCD spectral sum rules (QSSR). To NLO for the perturbative and power corrections, the hybrid mass is M_H=1.81(6) GeV and M_H < 2.2(2) GeV from the positivity of the spectral function. In the same way, but to LO, the four-quark state mass is M_{4q}= 1.70(4) GeV and M_{4q} < 2.4(1) GeV, while the molecule mass is about 1.3(1) GeV. The observed \pi_1(1400) and \pi_1(1600) might be explained by a two-component mixing with the set of input masses (1.2-1.3 ; 1.70-1.74) GeV and with a mixing angle \theta= -(11.7+- 2.2)^0, which slightly favours a molecule/four-quark mixing, and which eventually suggests that the \pi_1(2015) is mostly an hybrid meson. Isospin and non-exotic partners of the previous states and some of their radial excitations are also expected to be found in the energy region around 2 GeV. Further tests of this phenomenological scenario are required. |
2011.05378 | Thomas Edwards | Thomas D. P. Edwards, Bradley J. Kavanagh, Luca Visinelli, Christoph
Weniger | Transient Radio Signatures from Neutron Star Encounters with QCD Axion
Miniclusters | 11 pages, 5 figures. Code is available online at
https://github.com/bradkav/axion-miniclusters/ (archived at
https://doi.org/10.5281/zenodo.4006128 ). Joint submission with "Stellar
Disruption of Axion Miniclusters in the Milky Way" in astro-ph
(arXiv:2011.05377). Updated to match published version | Phys. Rev. Lett. 127, 131103 (2021) | 10.1103/PhysRevLett.127.131103 | null | hep-ph astro-ph.CO astro-ph.GA | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The QCD axion is expected to form dense structures known as axion
miniclusters if the Peccei-Quinn symmetry is broken after inflation.
Miniclusters that have survived until today will interact with neutron stars
(NSs) in the Milky Way to produce transient radio signals from axion-photon
conversion in the NS magnetosphere. We quantify the properties of these
encounters and find that they occur frequently
($\mathcal{O}(1-100)\,\mathrm{day}^{-1}$); last between a day and a few months;
are spatially clustered towards the Galactic center; and can reach observable
fluxes. These radio transients are within reach of current generation
telescopes and therefore offer a promising pathway to discovering QCD axion
dark matter.
| [
{
"created": "Tue, 10 Nov 2020 20:17:35 GMT",
"version": "v1"
},
{
"created": "Wed, 16 Dec 2020 17:55:51 GMT",
"version": "v2"
},
{
"created": "Fri, 22 Oct 2021 11:21:05 GMT",
"version": "v3"
}
] | 2021-10-25 | [
[
"Edwards",
"Thomas D. P.",
""
],
[
"Kavanagh",
"Bradley J.",
""
],
[
"Visinelli",
"Luca",
""
],
[
"Weniger",
"Christoph",
""
]
] | The QCD axion is expected to form dense structures known as axion miniclusters if the Peccei-Quinn symmetry is broken after inflation. Miniclusters that have survived until today will interact with neutron stars (NSs) in the Milky Way to produce transient radio signals from axion-photon conversion in the NS magnetosphere. We quantify the properties of these encounters and find that they occur frequently ($\mathcal{O}(1-100)\,\mathrm{day}^{-1}$); last between a day and a few months; are spatially clustered towards the Galactic center; and can reach observable fluxes. These radio transients are within reach of current generation telescopes and therefore offer a promising pathway to discovering QCD axion dark matter. |
2108.02540 | Abigail Keats MPhys | Fedor Bezrukov and Abigail Keats | Light inflaton model in a metastable Universe | 22 pages, 2 figures Version accepted in PRD, improved plots | null | 10.1103/PhysRevD.104.075020 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We minimally extend the SM with a Z$_2$ symmetric potential containing a
single scalar field, serving as our inflaton with a quartic self-coupling. In
the model we have symmetry breaking in both sectors, and with the addition of
an inflaton-Higgs portal, the Universe is able to efficiently reheat via 2-2
inflaton-Higgs scattering. Assuming that the Universe with a positive
cosmological constant should be metastable, only one particular symmetry
breaking pattern in the vacuum is possible, without the need to finely-tune the
Higgs' quartic self-coupling. Inflaton with masses in the range $O(10^{-3})\leq
m_{\chi}\leq m_{h}$ and mixing angles that span
$\theta_{m}^{2}=O(10^{-11}-10^{-2})$ evade all current cosmological,
experimental and stability constraints required for a metastable EW vacuum.
Upgraded particle physics experiments may be able to probe the parameter space
with $\theta_{m}^{2}\geq O(10^{-4})$, where we would observe trilinear Higgs
couplings suppressed by up to $2\%$ compared to the SM value. However to access
the parameter space of very weakly-coupled inflaton, we rely on the proposals
to build experiments that target the hidden sector.
| [
{
"created": "Thu, 5 Aug 2021 11:52:04 GMT",
"version": "v1"
},
{
"created": "Thu, 30 Sep 2021 15:44:54 GMT",
"version": "v2"
}
] | 2021-10-27 | [
[
"Bezrukov",
"Fedor",
""
],
[
"Keats",
"Abigail",
""
]
] | We minimally extend the SM with a Z$_2$ symmetric potential containing a single scalar field, serving as our inflaton with a quartic self-coupling. In the model we have symmetry breaking in both sectors, and with the addition of an inflaton-Higgs portal, the Universe is able to efficiently reheat via 2-2 inflaton-Higgs scattering. Assuming that the Universe with a positive cosmological constant should be metastable, only one particular symmetry breaking pattern in the vacuum is possible, without the need to finely-tune the Higgs' quartic self-coupling. Inflaton with masses in the range $O(10^{-3})\leq m_{\chi}\leq m_{h}$ and mixing angles that span $\theta_{m}^{2}=O(10^{-11}-10^{-2})$ evade all current cosmological, experimental and stability constraints required for a metastable EW vacuum. Upgraded particle physics experiments may be able to probe the parameter space with $\theta_{m}^{2}\geq O(10^{-4})$, where we would observe trilinear Higgs couplings suppressed by up to $2\%$ compared to the SM value. However to access the parameter space of very weakly-coupled inflaton, we rely on the proposals to build experiments that target the hidden sector. |
0802.4364 | Stephane Peigne | Stephane Peigne, Andre Peshier | Collisional energy loss of a fast heavy quark in a quark-gluon plasma | 6 pages | Phys.Rev.D77:114017,2008 | 10.1103/PhysRevD.77.114017 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss the average collisional energy loss dE/dx of a heavy quark
crossing a quark-gluon plasma, in the limit of high quark energy E >> M^2/T,
where M is the quark mass and T >> M is the plasma temperature. In the fixed
coupling approximation, at leading order dE/dx \propto \alpha_s^2, with a
coefficient which is logarithmically enhanced. The soft logarithm arising from
t-channel scattering off thermal partons is well-known, but a collinear
logarithm from u-channel exchange had previously been overlooked. We also
determine the constant beyond those leading logarithms. We then generalize our
calculation of dE/dx to the case of running coupling. We estimate the remaining
theoretical uncertainty of dE/dx, which turns out to be quite large under RHIC
conditions. Finally, we point out an approximate relation between dE/dx and the
QCD Debye mass, from which we derive an upper bound to dE/dx for all quark
energies.
| [
{
"created": "Fri, 29 Feb 2008 11:23:09 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Peigne",
"Stephane",
""
],
[
"Peshier",
"Andre",
""
]
] | We discuss the average collisional energy loss dE/dx of a heavy quark crossing a quark-gluon plasma, in the limit of high quark energy E >> M^2/T, where M is the quark mass and T >> M is the plasma temperature. In the fixed coupling approximation, at leading order dE/dx \propto \alpha_s^2, with a coefficient which is logarithmically enhanced. The soft logarithm arising from t-channel scattering off thermal partons is well-known, but a collinear logarithm from u-channel exchange had previously been overlooked. We also determine the constant beyond those leading logarithms. We then generalize our calculation of dE/dx to the case of running coupling. We estimate the remaining theoretical uncertainty of dE/dx, which turns out to be quite large under RHIC conditions. Finally, we point out an approximate relation between dE/dx and the QCD Debye mass, from which we derive an upper bound to dE/dx for all quark energies. |
2003.07626 | Wei Cheng | Hai-Bing Fu, Wei Cheng, Long Zeng, Dan-Dan Hu and Tao Zhong | Branching fractions and polarizations of $D\to V(\omega,\rho, K^*) \ell
\nu_\ell$ within QCD LCSR | 15 pages, 5 figures, 7 tables; minor changes; revised version to
appear in Physical Review Research | Phys. Rev. Research 2, 043129 (2020) | 10.1103/PhysRevResearch.2.043129 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper, we make a detailed study about the $D\to V$ helicity form
factors (HFFs) within the framework of QCD light-cone sum rule (LCSR) up to
twist-4 accuracy. After extrapolating the LCSR predictions of HFFs to the whole
physical $q^2$-region, we get the longitudinal, transverse and total
$|V_{cq}|$-independent decay widths of semileptonic decay $D\to
V\ell^+\nu_\ell$. Meanwhile, the branching fractions of these decays are also
obtained by using the $D^0(D^+)$-meson lifetime, which agree well with the
BES-III results within errors. As a further step, we also investigate the
differential and mean predictions for charged lepton (vector meson)
polarization in the final state $P_{\rm L,T}^\ell$ ($F_{\rm L,T}^\ell$), the
forward-backward asymmetry ${\cal A}_{\rm FB}^\ell$, and the lepton-side
convexity parameters ${\cal C}_{\rm F}^\ell$. Our predictions are consistent
with Covariant Confining Quark Model results within the errors. Thus, we think
the LCSR approach for HFFs is applicable for dealing with the $D$-meson
semileptonic decays.
| [
{
"created": "Tue, 17 Mar 2020 10:34:32 GMT",
"version": "v1"
},
{
"created": "Wed, 25 Mar 2020 02:24:16 GMT",
"version": "v2"
},
{
"created": "Sun, 4 Oct 2020 13:11:29 GMT",
"version": "v3"
}
] | 2020-10-28 | [
[
"Fu",
"Hai-Bing",
""
],
[
"Cheng",
"Wei",
""
],
[
"Zeng",
"Long",
""
],
[
"Hu",
"Dan-Dan",
""
],
[
"Zhong",
"Tao",
""
]
] | In this paper, we make a detailed study about the $D\to V$ helicity form factors (HFFs) within the framework of QCD light-cone sum rule (LCSR) up to twist-4 accuracy. After extrapolating the LCSR predictions of HFFs to the whole physical $q^2$-region, we get the longitudinal, transverse and total $|V_{cq}|$-independent decay widths of semileptonic decay $D\to V\ell^+\nu_\ell$. Meanwhile, the branching fractions of these decays are also obtained by using the $D^0(D^+)$-meson lifetime, which agree well with the BES-III results within errors. As a further step, we also investigate the differential and mean predictions for charged lepton (vector meson) polarization in the final state $P_{\rm L,T}^\ell$ ($F_{\rm L,T}^\ell$), the forward-backward asymmetry ${\cal A}_{\rm FB}^\ell$, and the lepton-side convexity parameters ${\cal C}_{\rm F}^\ell$. Our predictions are consistent with Covariant Confining Quark Model results within the errors. Thus, we think the LCSR approach for HFFs is applicable for dealing with the $D$-meson semileptonic decays. |
hep-ph/0411360 | Toru Goto | Toru Goto (YITP, Kyoto U) | Neutralino polarization effect in the squark cascade decay at LHC | 4 pages. Talk given at the 12th International Conference on
Suypersymmetry and Unification of the Fundamental Interactions (SUSY04), June
17-23, 2004, in Epochal Tsukuba, Tsukuba, Japan | null | null | null | hep-ph | null | We study the effect of the neutralino polarization in a squark cascade decay
$\tilde{q} \to q \tilde{\chi}^0_2 \to q l^\pm \tilde{l}^\mp \to q l^\pm
\tilde{l}^\mp \to q l^\pm l^\mp \tilde{\chi}^0_1$. Charge asymmetry in the
lepton-jet invariant mass distribution appears depending on the chirality
structure of the sfermion-fermion-neutralino coupling. With use of the Monte
Carlo simulation, we show that the asymmetry is measurable in LHC. We also show
that the distribution of the charge asymmetry is sensitive to the (s)lepton
flavor.
| [
{
"created": "Sun, 28 Nov 2004 09:20:56 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Goto",
"Toru",
"",
"YITP, Kyoto U"
]
] | We study the effect of the neutralino polarization in a squark cascade decay $\tilde{q} \to q \tilde{\chi}^0_2 \to q l^\pm \tilde{l}^\mp \to q l^\pm \tilde{l}^\mp \to q l^\pm l^\mp \tilde{\chi}^0_1$. Charge asymmetry in the lepton-jet invariant mass distribution appears depending on the chirality structure of the sfermion-fermion-neutralino coupling. With use of the Monte Carlo simulation, we show that the asymmetry is measurable in LHC. We also show that the distribution of the charge asymmetry is sensitive to the (s)lepton flavor. |
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