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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
hep-ph/9602432 | Alberto Gabutti | A. Gabutti, M. Olechowski, S. Cooper, S. Pokorski, L. Stodolski | Light Neutralinos as Dark Matter in the Unconstrained Minimal
Supersymmetric Standard Model | Submitted to Astroparticle Physics, 19 Feb. 96, Latex 23 pages with
24 figures in a gzip compressed file FIGURE.PS.GZ available via anonymous ftp
from ftp://iws104.mppmu.mpg.de/pub/gabutti | Astropart.Phys.6:1-24,1996 | 10.1016/S0927-6505(96)00031-X | MPI-PhE/96-02, DFFT 1/96 | hep-ph astro-ph | null | The allowed parameter space for the lightest neutralino as the dark matter is
explored using the Minimal Supersymmetric Standard Model as the low-energy
effective theory without further theoretical constraints such as GUT. Selecting
values of the parameters which are in agreement with present experimental
limits and applying the additional requirement that the lightest neutralino be
in a cosmologically interesting range, we give limits on the neutralino mass
and composition. A similar analysis is also performed implementing the grand
unification constraints. The elastic scattering cross section of the selected
neutralinos on $^{27}$Al and on other materials for dark matter experiments is
discussed.
| [
{
"created": "Thu, 29 Feb 1996 14:33:00 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Gabutti",
"A.",
""
],
[
"Olechowski",
"M.",
""
],
[
"Cooper",
"S.",
""
],
[
"Pokorski",
"S.",
""
],
[
"Stodolski",
"L.",
""
]
] | The allowed parameter space for the lightest neutralino as the dark matter is explored using the Minimal Supersymmetric Standard Model as the low-energy effective theory without further theoretical constraints such as GUT. Selecting values of the parameters which are in agreement with present experimental limits and applying the additional requirement that the lightest neutralino be in a cosmologically interesting range, we give limits on the neutralino mass and composition. A similar analysis is also performed implementing the grand unification constraints. The elastic scattering cross section of the selected neutralinos on $^{27}$Al and on other materials for dark matter experiments is discussed. |
1906.02755 | Pranjal Ralegankar | Peter Adshead, Pranjal Ralegankar and Jessie Shelton | Reheating in two-sector cosmology | 29 pages + 21 pages appendices; matches version accepted in JHEP | null | 10.1007/JHEP08(2019)151 | null | hep-ph astro-ph.CO hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We analyze reheating scenarios where a hidden sector is populated during
reheating along with the sector containing the Standard Model. We numerically
solve the Boltzmann equations describing perturbative reheating of the two
sectors, including the full dependence on quantum statistics, and study how
quantum statistical effects during reheating as well as the non-equilibrium
inflaton-mediated energy transfer between the two sectors affects the
temperature evolution of the two radiation baths. We obtain new power laws
describing the temperature evolution of fermions and bosons when quantum
statistics are important during reheating. We show that inflaton-mediated
scattering is generically most important at radiation temperatures $T\sim
M_\phi/4$, and build on this observation to obtain analytic estimates for the
temperature asymmetry produced by asymmetric reheating. We find that for
reheating temperatures $T_{\textrm{rh}} \ll M_{\phi}/4$, classical perturbative
reheating provides an excellent approximation to the final temperature
asymmetry, while for $T_{\textrm{rh}}\gg M_{\phi}/4$, inflaton-mediated
scattering dominates the population of the colder sector and thus the final
temperature asymmetry. We additionally present new techniques to calculate
energy transfer rates between two relativistic species at different
temperatures.
| [
{
"created": "Thu, 6 Jun 2019 18:00:22 GMT",
"version": "v1"
},
{
"created": "Tue, 13 Aug 2019 15:18:35 GMT",
"version": "v2"
}
] | 2019-10-02 | [
[
"Adshead",
"Peter",
""
],
[
"Ralegankar",
"Pranjal",
""
],
[
"Shelton",
"Jessie",
""
]
] | We analyze reheating scenarios where a hidden sector is populated during reheating along with the sector containing the Standard Model. We numerically solve the Boltzmann equations describing perturbative reheating of the two sectors, including the full dependence on quantum statistics, and study how quantum statistical effects during reheating as well as the non-equilibrium inflaton-mediated energy transfer between the two sectors affects the temperature evolution of the two radiation baths. We obtain new power laws describing the temperature evolution of fermions and bosons when quantum statistics are important during reheating. We show that inflaton-mediated scattering is generically most important at radiation temperatures $T\sim M_\phi/4$, and build on this observation to obtain analytic estimates for the temperature asymmetry produced by asymmetric reheating. We find that for reheating temperatures $T_{\textrm{rh}} \ll M_{\phi}/4$, classical perturbative reheating provides an excellent approximation to the final temperature asymmetry, while for $T_{\textrm{rh}}\gg M_{\phi}/4$, inflaton-mediated scattering dominates the population of the colder sector and thus the final temperature asymmetry. We additionally present new techniques to calculate energy transfer rates between two relativistic species at different temperatures. |
hep-ph/0305025 | Ted Barnes | T.Barnes (1,2), F.E.Close (3) and H.J.Lipkin (4,5,6) ((1) Physics
Division, Oak Ridge National Laboratory, (2) Department of Physics and
Astronomy, University of Tennessee, (3) Department of Theoretical Physics,
University of Oxford, (4) Department of Particle Physics, Weizmann Institute
of Science, (5) Faculty of Exact Sciences, Tel Aviv University, (6) High
Energy Physics Division, Argonne National Laboratory) | Implications of a DK Molecule at 2.32 GeV | 6 pages, 1 figure | Phys.Rev.D68:054006,2003 | 10.1103/PhysRevD.68.054006 | null | hep-ph nucl-th | null | We discuss the implications of a possible quasinuclear DK bound state at 2.32
GeV. Evidence for such a state was recently reported in D_s^+pi^o by the BaBar
Collaboration. We first note that a conventional quark model c-sbar assignment
is implausible, and then consider other options involving multiquark systems.
An I=0 c sbar n nbar baryonium assignment is one possibility. We instead favor
a DK meson molecule assignment, which can account for the mass and quantum
numbers of this state. The higher-mass scalar c-sbar state expected at 2.48 GeV
is predicted to have a very large DK coupling, which would encourage formation
of an I=0 DK molecule. Isospin mixing is expected in hadron molecules, and a
dominantly I=0 DK state with some I=1 admixture could explain both the narrow
total width of the 2.32 GeV state as well as the observed decay to D_s^+ pi^o.
Additional measurements that can be used to test this and related scenarios are
discussed.
| [
{
"created": "Fri, 2 May 2003 19:45:14 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Barnes",
"T.",
""
],
[
"Close",
"F. E.",
""
],
[
"Lipkin",
"H. J.",
""
]
] | We discuss the implications of a possible quasinuclear DK bound state at 2.32 GeV. Evidence for such a state was recently reported in D_s^+pi^o by the BaBar Collaboration. We first note that a conventional quark model c-sbar assignment is implausible, and then consider other options involving multiquark systems. An I=0 c sbar n nbar baryonium assignment is one possibility. We instead favor a DK meson molecule assignment, which can account for the mass and quantum numbers of this state. The higher-mass scalar c-sbar state expected at 2.48 GeV is predicted to have a very large DK coupling, which would encourage formation of an I=0 DK molecule. Isospin mixing is expected in hadron molecules, and a dominantly I=0 DK state with some I=1 admixture could explain both the narrow total width of the 2.32 GeV state as well as the observed decay to D_s^+ pi^o. Additional measurements that can be used to test this and related scenarios are discussed. |
2010.13709 | Felipe J. Llanes-Estrada | Alexandre Salas-Bern\'ardez, Felipe J. Llanes-Estrada, Juan
Escudero-Pedrosa (Univ. Complutense Madrid) and Jose Antonio Oller (Univ.
Murcia) | Systematizing and addressing theory uncertainties of unitarization with
the Inverse Amplitude Method | Revised version, 47 pages in SciPost format, with 13 captioned
figures | SciPost Phys. 11, 020 (2021) | 10.21468/SciPostPhys.11.2.020 | doi: 10.21468/SciPostPhys.11.2.020 | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Effective Field Theories (EFTs) constructed as derivative expansions in
powers of momentum, in the spirit of Chiral Perturbation Theory (ChPT), are a
controllable approximation to strong dynamics as long as the energy of the
interacting particles remains small, as they do not respect exact elastic
unitarity. This limits their predictive power towards new physics at a higher
scale if small separations from the Standard Model are found at the LHC or
elsewhere. Unitarized chiral perturbation theory techniques have been devised
to extend the reach of the EFT to regimes where partial waves are saturating
unitarity, but their uncertainties have hitherto not been addressed thoroughly.
Here we take one of the best known of them, the Inverse Amplitude Method (IAM),
and carefully following its derivation, we quantify the uncertainty introduced
at each step. We compare its hadron ChPT and its electroweak sector Higgs EFT
applications. We find that the relative theoretical uncertainty of the IAM at
the mass of the first resonance encountered in a partial-wave is of the same
order in the counting as the starting uncertainty of the EFT at near-threshold
energies, so that its unitarized extension should \textit{a priori} be expected
to be reasonably successful. This is so provided a check for zeroes of the
partial wave amplitude is carried out and, if they appear near the resonance
region, we show how to modify adequately the IAM to take them into account.
| [
{
"created": "Mon, 26 Oct 2020 16:52:33 GMT",
"version": "v1"
},
{
"created": "Fri, 4 Jun 2021 08:32:34 GMT",
"version": "v2"
}
] | 2021-08-11 | [
[
"Salas-Bernárdez",
"Alexandre",
"",
"Univ. Complutense Madrid"
],
[
"Llanes-Estrada",
"Felipe J.",
"",
"Univ. Complutense Madrid"
],
[
"Escudero-Pedrosa",
"Juan",
"",
"Univ. Complutense Madrid"
],
[
"Oller",
"Jose Antonio",
"",
"Univ.\n ... | Effective Field Theories (EFTs) constructed as derivative expansions in powers of momentum, in the spirit of Chiral Perturbation Theory (ChPT), are a controllable approximation to strong dynamics as long as the energy of the interacting particles remains small, as they do not respect exact elastic unitarity. This limits their predictive power towards new physics at a higher scale if small separations from the Standard Model are found at the LHC or elsewhere. Unitarized chiral perturbation theory techniques have been devised to extend the reach of the EFT to regimes where partial waves are saturating unitarity, but their uncertainties have hitherto not been addressed thoroughly. Here we take one of the best known of them, the Inverse Amplitude Method (IAM), and carefully following its derivation, we quantify the uncertainty introduced at each step. We compare its hadron ChPT and its electroweak sector Higgs EFT applications. We find that the relative theoretical uncertainty of the IAM at the mass of the first resonance encountered in a partial-wave is of the same order in the counting as the starting uncertainty of the EFT at near-threshold energies, so that its unitarized extension should \textit{a priori} be expected to be reasonably successful. This is so provided a check for zeroes of the partial wave amplitude is carried out and, if they appear near the resonance region, we show how to modify adequately the IAM to take them into account. |
2211.14110 | Juliane Haug | Juliane Haug and Fabian Wunder | The massless single off-shell scalar box integral -- branch cut
structure and all-order epsilon expansion | 29 pages, 5 figures, , updated to match version published in JHEP | JHEP 02 (2023) 177 | 10.1007/JHEP02(2023)177 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We investigate the single off-shell scalar box integral with massless
internal lines in dimensional regularization. A special emphasis is given to
higher orders in the dimensional regularization parameter epsilon, its branch
cut structure, and kinematic limits. Common representations of the box integral
introduce superficial branch cuts, which we eliminate to all orders in the
epsilon expansion. In the literature so far a satisfactory solution for this
issue only exists up to finite order in the epsilon expansion. However, for
calculations at NNLO in perturbation theory, higher orders in epsilon of this
integral are required. In this paper, we present results to all orders in
epsilon in terms of single-valued polylogarithms and explicitly determine the
real and imaginary part of the box integral in all kinematic regions.
| [
{
"created": "Fri, 25 Nov 2022 13:51:02 GMT",
"version": "v1"
},
{
"created": "Mon, 30 Jan 2023 15:05:11 GMT",
"version": "v2"
},
{
"created": "Thu, 11 May 2023 08:59:02 GMT",
"version": "v3"
}
] | 2023-05-12 | [
[
"Haug",
"Juliane",
""
],
[
"Wunder",
"Fabian",
""
]
] | We investigate the single off-shell scalar box integral with massless internal lines in dimensional regularization. A special emphasis is given to higher orders in the dimensional regularization parameter epsilon, its branch cut structure, and kinematic limits. Common representations of the box integral introduce superficial branch cuts, which we eliminate to all orders in the epsilon expansion. In the literature so far a satisfactory solution for this issue only exists up to finite order in the epsilon expansion. However, for calculations at NNLO in perturbation theory, higher orders in epsilon of this integral are required. In this paper, we present results to all orders in epsilon in terms of single-valued polylogarithms and explicitly determine the real and imaginary part of the box integral in all kinematic regions. |
2309.16576 | Renaud Boussarie | Renaud Boussarie, Yacine Mehtar-Tani | Low and moderate $x$ gluon contribution to exclusive Compton scattering
processes | 43 pages, 5 figures | null | null | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We revisit the high energy semi-classical description of the exclusive
processes DVCS, TCS, and Double DVCS by explicitly keeping track of the Feynman
$x$ dependence in both the hard and the hadronic matrix elements. This is
achieved by a modification of the standard shock wave approximation to derive
the effective Feynman rules, which leads to a generic expression on which we
then perform a partial twist expansion to get rid of quantities suppressed by
the proper physical scales. We obtain a compact factorized master formula that
can be used to investigate the Bjorken limit at leading twist. In particular,
we recover the full one-loop result in the collinear limit for pure gluon
exchange with the target. Finally, we discuss the subtleties in taking the
simultaneous collinear and small $x$ limit.
| [
{
"created": "Thu, 28 Sep 2023 16:33:00 GMT",
"version": "v1"
}
] | 2023-09-29 | [
[
"Boussarie",
"Renaud",
""
],
[
"Mehtar-Tani",
"Yacine",
""
]
] | We revisit the high energy semi-classical description of the exclusive processes DVCS, TCS, and Double DVCS by explicitly keeping track of the Feynman $x$ dependence in both the hard and the hadronic matrix elements. This is achieved by a modification of the standard shock wave approximation to derive the effective Feynman rules, which leads to a generic expression on which we then perform a partial twist expansion to get rid of quantities suppressed by the proper physical scales. We obtain a compact factorized master formula that can be used to investigate the Bjorken limit at leading twist. In particular, we recover the full one-loop result in the collinear limit for pure gluon exchange with the target. Finally, we discuss the subtleties in taking the simultaneous collinear and small $x$ limit. |
1207.3588 | Satyanarayan Mukhopadhyay | Shankha Banerjee, Satyanarayan Mukhopadhyay and Biswarup Mukhopadhyaya | New Higgs interactions and recent data from the LHC and the Tevatron | 18 pages, 4 figures; v2: minor additions to text | JHEP10 (2012) 062 | 10.1007/JHEP10(2012)062 | RECAPP-HRI-2012-008 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We perform a multi-parameter global analysis of all data available till date
from the ATLAS, CMS and Tevatron experiments, on the signals of a Higgs boson,
to investigate how much scope exists for departure from the standard model
prediction. We adopt a very general and model-independent scenario, where
separate deviations from standard model values are possible for couplings of
the observed scalar with up-and down-type fermions, W-and Z-boson pairs, as
well as gluon and photon pair effective interactions. An arbitrary phase in the
coupling with the top-pair, and the provision for an invisible decay width for
the scalar are also introduced. After performing a global fit with seven
parameters, we find that their values at 95% confidence level can be
considerably different from standard model expectations. Moreover, rather
striking implications of the phase in top-quark coupling are noticed. We also
note that the invisible branching ratio can be sizeable, especially when the
couplings of the Higgs to W-and Z-pairs are allowed to be different.
| [
{
"created": "Mon, 16 Jul 2012 07:43:46 GMT",
"version": "v1"
},
{
"created": "Thu, 11 Oct 2012 05:54:57 GMT",
"version": "v2"
}
] | 2012-10-12 | [
[
"Banerjee",
"Shankha",
""
],
[
"Mukhopadhyay",
"Satyanarayan",
""
],
[
"Mukhopadhyaya",
"Biswarup",
""
]
] | We perform a multi-parameter global analysis of all data available till date from the ATLAS, CMS and Tevatron experiments, on the signals of a Higgs boson, to investigate how much scope exists for departure from the standard model prediction. We adopt a very general and model-independent scenario, where separate deviations from standard model values are possible for couplings of the observed scalar with up-and down-type fermions, W-and Z-boson pairs, as well as gluon and photon pair effective interactions. An arbitrary phase in the coupling with the top-pair, and the provision for an invisible decay width for the scalar are also introduced. After performing a global fit with seven parameters, we find that their values at 95% confidence level can be considerably different from standard model expectations. Moreover, rather striking implications of the phase in top-quark coupling are noticed. We also note that the invisible branching ratio can be sizeable, especially when the couplings of the Higgs to W-and Z-pairs are allowed to be different. |
hep-ph/0101227 | Anatoly Radyushkin | A.V. Radyushkin | Introduction to QCD Sum Rule Approach | Published in " Strong Interactions at Low and Intermediate Energies",
Proceedings of the 13th Annual HUGS at CEBAF, 26May-12 June 1998; Edited by
J.L. Goity, World Scientific (2000) pp. 91-150 | null | null | null | hep-ph | null | In these lectures, I describe the techniques used within the QCD sum rule
approach. The basic concepts of the approach are introduced using a simple
model of quantum-mechanical oscillator in 2+1 dimensions. Then I discuss their
field-theoretical extension and the construction of the operator product
expansion for current correlators in QCD. The calculation of static parameters
is illustrated on the example of sum rules in the vector and axial meson
channels. Finally, the QCD sum rule calculation of the pion electromagnetic
form factor is presented as an example of application of the method to dynamic
characteristics of the hadrons.
| [
{
"created": "Fri, 19 Jan 2001 21:02:02 GMT",
"version": "v1"
},
{
"created": "Wed, 24 Jan 2001 19:25:55 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Radyushkin",
"A. V.",
""
]
] | In these lectures, I describe the techniques used within the QCD sum rule approach. The basic concepts of the approach are introduced using a simple model of quantum-mechanical oscillator in 2+1 dimensions. Then I discuss their field-theoretical extension and the construction of the operator product expansion for current correlators in QCD. The calculation of static parameters is illustrated on the example of sum rules in the vector and axial meson channels. Finally, the QCD sum rule calculation of the pion electromagnetic form factor is presented as an example of application of the method to dynamic characteristics of the hadrons. |
hep-ph/0210297 | Volodymyr Magas | L.P. Csernai, M.I. Gorenstein, L.L. Jenkovszky, I. Lovas, V.K. Magas | Can supercooling explain the HBT puzzle? | 9 pages, 2 figures | Phys.Lett. B551 (2003) 121-126 | 10.1016/S0370-2693(02)03003-4 | null | hep-ph | null | Possible hadronization of supercooled QGP, created in heavy ion collisions at
RHIC and SPS, is discussed within a Bjorken hydrodynamic model. Such a
hadronization is expected to be a very fast shock-like process, what, if
hadronization coincides or shortly followed by freeze out, could explain a part
of the HBT puzzle, i.e. the flash-like particle emission
($R_{out}/R_{side}\approx 1$). HBT data also show that the expansion time
before freeze out is very short ($\sim 6-10 fm/c$). In this work we discuss
question of supercooled QGP and the timescale of the reaction.
| [
{
"created": "Tue, 22 Oct 2002 13:13:51 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Csernai",
"L. P.",
""
],
[
"Gorenstein",
"M. I.",
""
],
[
"Jenkovszky",
"L. L.",
""
],
[
"Lovas",
"I.",
""
],
[
"Magas",
"V. K.",
""
]
] | Possible hadronization of supercooled QGP, created in heavy ion collisions at RHIC and SPS, is discussed within a Bjorken hydrodynamic model. Such a hadronization is expected to be a very fast shock-like process, what, if hadronization coincides or shortly followed by freeze out, could explain a part of the HBT puzzle, i.e. the flash-like particle emission ($R_{out}/R_{side}\approx 1$). HBT data also show that the expansion time before freeze out is very short ($\sim 6-10 fm/c$). In this work we discuss question of supercooled QGP and the timescale of the reaction. |
2204.04116 | Di Wang | Di Wang | Pursuit of new physics within the $\Lambda_c\to \Delta K$ decays | 13 pages, 1 figure, published version | Eur. Phys. J. C 82, 1071 (2022) | 10.1140/epjc/s10052-022-11013-5 | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | We point out the $CP$ asymmetry in the chain decay of $\Lambda_c^+\to
\Delta^+K(t)(\to \pi^+\pi^-)$ is determined by the branching fractions of
$\Lambda^+_c\to \Delta^{++} K^-$, $\Lambda^+_c\to \Delta^{+} K^0_{S,L}$ and
$\Lambda^+_c\to \Delta^{0} K^+$ modes under the isospin symmetry. The
ambiguities from loop-induced quantities and $SU(3)_F$ breaking hadronic
effects are avoided. Once the $CP$ asymmetry in the $\Lambda_c^+$ decays into
$\Delta^+$ and neutral kaons is confirmed by experiments, we can check if it is
beyond the Standard Model, or verify the $CP$-violating effect resulted from
the interference between the Cabibbo-favored and the doubly Cabibbo-suppressed
amplitudes with the neutral kaon mixing. Future measurements of branching
fractions play a critical role in reducing the uncertainties.
| [
{
"created": "Fri, 8 Apr 2022 15:16:01 GMT",
"version": "v1"
},
{
"created": "Tue, 13 Sep 2022 13:34:34 GMT",
"version": "v2"
},
{
"created": "Tue, 29 Nov 2022 10:27:04 GMT",
"version": "v3"
}
] | 2022-11-30 | [
[
"Wang",
"Di",
""
]
] | We point out the $CP$ asymmetry in the chain decay of $\Lambda_c^+\to \Delta^+K(t)(\to \pi^+\pi^-)$ is determined by the branching fractions of $\Lambda^+_c\to \Delta^{++} K^-$, $\Lambda^+_c\to \Delta^{+} K^0_{S,L}$ and $\Lambda^+_c\to \Delta^{0} K^+$ modes under the isospin symmetry. The ambiguities from loop-induced quantities and $SU(3)_F$ breaking hadronic effects are avoided. Once the $CP$ asymmetry in the $\Lambda_c^+$ decays into $\Delta^+$ and neutral kaons is confirmed by experiments, we can check if it is beyond the Standard Model, or verify the $CP$-violating effect resulted from the interference between the Cabibbo-favored and the doubly Cabibbo-suppressed amplitudes with the neutral kaon mixing. Future measurements of branching fractions play a critical role in reducing the uncertainties. |
0810.4988 | Alfredo Valcarce | J. Vijande, A. Valcarce, F. Fernandez | A multiquark description of the $D_{sJ}(2860)$ and $D_{sJ}(2700)$ | 10 pages, 5 tables | Phys. Rev. D 79, 037501 (2009) | 10.1103/PhysRevD.79.037501 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Within a theoretical framework that accounts for all open-charm mesons,
including the $D_0^*(2308)$, the $D_{sJ}^*(2317)$ and the $D_{sJ}(2460)$, we
analyze the structure and explore possible quantum number assignments for the
$D_{sJ}(2860)$ and the $D_{sJ}(2700)$ mesons reported by BABAR and Belle
Collaborations. The open-charm sector is properly described if considered as a
combination of conventional quark-antiquark states and four--quark components.
All negative parity and $2^+$ states can be understood in terms only of $q\bar
q$ components, however the description of the $0^+$ and $1^+$ mesons is
improved whenever the mixing between two-- and four--quarks configurations is
included. We analyze all possible quantum number assignments for the
$D_{sJ}(2860)$ in terms of both $c\bar s$ and $cn\bar s\bar n$ configurations.
We discuss the role played by the electromagnetic and strong decay widths as
basic tools to distinguish among them. The broad structure reported by BABAR
near 2.7 GeV is also analyzed.
| [
{
"created": "Tue, 28 Oct 2008 08:53:44 GMT",
"version": "v1"
},
{
"created": "Thu, 5 Feb 2009 15:46:57 GMT",
"version": "v2"
}
] | 2009-02-05 | [
[
"Vijande",
"J.",
""
],
[
"Valcarce",
"A.",
""
],
[
"Fernandez",
"F.",
""
]
] | Within a theoretical framework that accounts for all open-charm mesons, including the $D_0^*(2308)$, the $D_{sJ}^*(2317)$ and the $D_{sJ}(2460)$, we analyze the structure and explore possible quantum number assignments for the $D_{sJ}(2860)$ and the $D_{sJ}(2700)$ mesons reported by BABAR and Belle Collaborations. The open-charm sector is properly described if considered as a combination of conventional quark-antiquark states and four--quark components. All negative parity and $2^+$ states can be understood in terms only of $q\bar q$ components, however the description of the $0^+$ and $1^+$ mesons is improved whenever the mixing between two-- and four--quarks configurations is included. We analyze all possible quantum number assignments for the $D_{sJ}(2860)$ in terms of both $c\bar s$ and $cn\bar s\bar n$ configurations. We discuss the role played by the electromagnetic and strong decay widths as basic tools to distinguish among them. The broad structure reported by BABAR near 2.7 GeV is also analyzed. |
hep-ph/9905439 | Antal Jakovac | A. Jakovac, A. Patkos, P. Petreczky and Zs. Szep | Effective theory for the soft fluctuation modes in the spontaneously
broken phase of the N-component scalar field theory | 21 pages, LaTeX; final version to appear in Phys. Rev. D | Phys.Rev. D61 (2000) 025006 | 10.1103/PhysRevD.61.025006 | null | hep-ph | null | The effective dynamics of the low-frequency modes is derived for the O(N)
symmetric scalar field theory in the broken symmetry phase. The effect of the
high-frequency fluctuations is taken into account at one-loop level exactly. A
new length scale is shown to govern the long-time asymptotics of the linear
response function of the Goldstone modes. The large time asymptotic decay of an
arbitrary fluctuation is determined in the linear regime. We propose a set of
local equations for the numerical solution of the effective non-linear
dynamics. The applicability of the usual gradient expansion is carefully
assessed.
| [
{
"created": "Fri, 21 May 1999 13:53:35 GMT",
"version": "v1"
},
{
"created": "Wed, 6 Oct 1999 14:43:52 GMT",
"version": "v2"
}
] | 2009-10-31 | [
[
"Jakovac",
"A.",
""
],
[
"Patkos",
"A.",
""
],
[
"Petreczky",
"P.",
""
],
[
"Szep",
"Zs.",
""
]
] | The effective dynamics of the low-frequency modes is derived for the O(N) symmetric scalar field theory in the broken symmetry phase. The effect of the high-frequency fluctuations is taken into account at one-loop level exactly. A new length scale is shown to govern the long-time asymptotics of the linear response function of the Goldstone modes. The large time asymptotic decay of an arbitrary fluctuation is determined in the linear regime. We propose a set of local equations for the numerical solution of the effective non-linear dynamics. The applicability of the usual gradient expansion is carefully assessed. |
hep-ph/9702391 | Myriam Mondragon | J. Kubo (Kanazawa Univ.), M. Mondragon (IF-UNAM, Mexico), G. Zoupanos
(Nat. Tech. Univ., Athens) | Gauge-Yukawa Unified Models | Presented by G. Zoupanos at ICHEP 96 | null | null | NTUA58/96 | hep-ph | null | Gauge-Yukawa Unification (GYU) is obtained in GUTs by searching for
renormalization group invariant relations among gauge and Yukawa couplings
beyond the unification scale. Of particular interest are two supersymmetric
GUTs, the finite and the minimal SU(5) models. Both models provided us,among
others,with predictions of the top quark mass which so far have passed
successfully the tests of progressively more accurate measurements.
| [
{
"created": "Fri, 21 Feb 1997 20:14:43 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Kubo",
"J.",
"",
"Kanazawa Univ."
],
[
"Mondragon",
"M.",
"",
"IF-UNAM, Mexico"
],
[
"Zoupanos",
"G.",
"",
"Nat. Tech. Univ., Athens"
]
] | Gauge-Yukawa Unification (GYU) is obtained in GUTs by searching for renormalization group invariant relations among gauge and Yukawa couplings beyond the unification scale. Of particular interest are two supersymmetric GUTs, the finite and the minimal SU(5) models. Both models provided us,among others,with predictions of the top quark mass which so far have passed successfully the tests of progressively more accurate measurements. |
2211.16818 | Francesco Giovanni Celiberto | Andr\`ee Dafne Bolognino, Francesco Giovanni Celiberto, Michael
Fucilla, Dmitry Yu. Ivanov, Mohammed M.A. Mohammed, Alessandro Papa | High-energy signals from heavy-flavor physics | 6 pages, 1 figure. Presented by Michael Fucilla at "Diffraction and
Low-$x$ 2022", Corigliano Calabro (Italy), September 24-30, 2022 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Working in the hybrid high-energy/collinear factorization, where the
next-to-leading resummation of energy logarithms is combined with collinear
parton densities and fragmentation functions, we study observables sensitive to
high-energy dynamics in the context of heavy-flavor physics.
| [
{
"created": "Wed, 30 Nov 2022 08:32:22 GMT",
"version": "v1"
}
] | 2022-12-01 | [
[
"Bolognino",
"Andrèe Dafne",
""
],
[
"Celiberto",
"Francesco Giovanni",
""
],
[
"Fucilla",
"Michael",
""
],
[
"Ivanov",
"Dmitry Yu.",
""
],
[
"Mohammed",
"Mohammed M. A.",
""
],
[
"Papa",
"Alessandro",
""
]
] | Working in the hybrid high-energy/collinear factorization, where the next-to-leading resummation of energy logarithms is combined with collinear parton densities and fragmentation functions, we study observables sensitive to high-energy dynamics in the context of heavy-flavor physics. |
0911.3027 | Ahmed Ali | Ahmed Ali, Eduard A. Kuraev, Yury Bystritskiy | Radiatively corrected lepton energy distributions in top quark decays $t
\to bW^+ \to b(\ell^+ \nu_\ell)$ and $t \to bH^+ \to b (\tau^+ \nu_\tau)$ and
single charged prong energy distributions from subsequent $\tau^+$ decays | 39 pages, 18 figures | Eur.Phys.J.C67:377-395,2010 | 10.1140/epjc/s10052-010-1300-z | DESY 09-115 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We calculate the QED and QCD radiative corrections to the charged lepton
energy distributions in the dominant semileptonic decays of the top quark $t
\to b W^+ \to b(\ell^+ \nu_\ell)$ $(\ell=e, \mu, \tau)$ in the standard
model(SM), and for the decay $t \to b H^+ \to b(\tau^+ \nu_\tau)$ in an
extension of the SM having a charged Higgs boson $H^\pm$ with $m_{H^\pm} < m_t
-m_b$. The QCD corrections are calculated in the leading and next-to-leading
logarithmic approximations, but the QED corrections are considered in the
leading logarithmic approximation only. These corrections are numerically
important for precisely testing the universality of the charged current weak
interactions in $t$-quark decays. As the $\tau^+$ leptons arising from the
decays $W^+ \to \tau^+ \nu_\tau$ and $H^+\to \tau^+ \nu_\tau$ are predominantly
left- and right-polarised, respectively, influencing the energy distributions
of the decay products in the subsequent decays of the $\tau^+$, we work out the
effect of the radiative corrections on such distributions in the dominant
(one-charged prong) decay channels
$ \tau^+ \to \pi^+ \bar{\nu}_\tau, \rho^+ \bar{\nu}_\tau, a_1^+
\bar{\nu}_\tau$ and $\ell^+ \nu_\ell \bar{\nu}_\tau$. The inclusive $\pi^+$
energy spectra in the decay chains $t \to b(W^+,H^+) \to b (\tau^+ \nu_\tau)
\to b (\pi^+ \bar{\nu}_\tau \nu_\tau +X)$ are calculated, which can help in
searching for the induced $H^\pm$ effects at the Tevatron and the LHC.
| [
{
"created": "Mon, 16 Nov 2009 15:49:03 GMT",
"version": "v1"
}
] | 2014-11-20 | [
[
"Ali",
"Ahmed",
""
],
[
"Kuraev",
"Eduard A.",
""
],
[
"Bystritskiy",
"Yury",
""
]
] | We calculate the QED and QCD radiative corrections to the charged lepton energy distributions in the dominant semileptonic decays of the top quark $t \to b W^+ \to b(\ell^+ \nu_\ell)$ $(\ell=e, \mu, \tau)$ in the standard model(SM), and for the decay $t \to b H^+ \to b(\tau^+ \nu_\tau)$ in an extension of the SM having a charged Higgs boson $H^\pm$ with $m_{H^\pm} < m_t -m_b$. The QCD corrections are calculated in the leading and next-to-leading logarithmic approximations, but the QED corrections are considered in the leading logarithmic approximation only. These corrections are numerically important for precisely testing the universality of the charged current weak interactions in $t$-quark decays. As the $\tau^+$ leptons arising from the decays $W^+ \to \tau^+ \nu_\tau$ and $H^+\to \tau^+ \nu_\tau$ are predominantly left- and right-polarised, respectively, influencing the energy distributions of the decay products in the subsequent decays of the $\tau^+$, we work out the effect of the radiative corrections on such distributions in the dominant (one-charged prong) decay channels $ \tau^+ \to \pi^+ \bar{\nu}_\tau, \rho^+ \bar{\nu}_\tau, a_1^+ \bar{\nu}_\tau$ and $\ell^+ \nu_\ell \bar{\nu}_\tau$. The inclusive $\pi^+$ energy spectra in the decay chains $t \to b(W^+,H^+) \to b (\tau^+ \nu_\tau) \to b (\pi^+ \bar{\nu}_\tau \nu_\tau +X)$ are calculated, which can help in searching for the induced $H^\pm$ effects at the Tevatron and the LHC. |
hep-ph/0407184 | Kopylov | Anatoly Kopylov | A Remark on A Remark on Neutrino Oscillations Observed in KamLAND
Experiment | 1 page | null | null | null | hep-ph | null | It is shown that equal magnitudes of the transitions $\bar \nu_e \to \bar
\nu_{\mu}$ and $\bar \nu_e \to \bar \nu_{\tau}$ in the disappearance of reactor
$\bar \nu_e$ discovered in the KamLAND experiment just follows at
$\theta_{23}=\pi/4$ and $\theta_{13}=0$ from pure symmetry of $\nu_{\mu}$ and
$\nu_{\tau}$ states relatively the mass states.
| [
{
"created": "Fri, 16 Jul 2004 07:00:13 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Kopylov",
"Anatoly",
""
]
] | It is shown that equal magnitudes of the transitions $\bar \nu_e \to \bar \nu_{\mu}$ and $\bar \nu_e \to \bar \nu_{\tau}$ in the disappearance of reactor $\bar \nu_e$ discovered in the KamLAND experiment just follows at $\theta_{23}=\pi/4$ and $\theta_{13}=0$ from pure symmetry of $\nu_{\mu}$ and $\nu_{\tau}$ states relatively the mass states. |
1409.8005 | Gui-Jun Ding | Gui-Jun Ding, Stephen F. King and Thomas Neder | Generalised CP and $\Delta (6n^2)$ Family Symmetry in Semi-Direct Models
of Leptons | 65 pages, 19 figures, and the predictions for neutrinoless double
beta decay are updated | null | 10.1007/JHEP12(2014)007 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We perform a detailed analysis of $\Delta (6n^2)$ family symmetry combined
with a generalised CP symmetry in the lepton sector, breaking to different
remnant symmetries $G_{\nu}$ in the neutrino and $G_{l}$ in the charged lepton
sector, together with different remnant CP symmetries in each sector. We
discuss the resulting mass and mixing predictions for $G_{\nu}=Z_2$ with
$G_{l}=K_4,Z_p,p>2$ and $G_{\nu}=K_4$ with $G_{l}=Z_2$. All cases correspond to
the preserved symmetry smaller than the full Klein symmetry, as in the
semi-direct approach, leading to predictions which depend on a single
undetermined real parameter, which mainly determines the reactor angle. We
focus on five phenomenologically allowed cases for which we present the
resulting predictions for the PMNS parameters as a function of $n$, as well as
the predictions for neutrinoless double beta decay.
| [
{
"created": "Mon, 29 Sep 2014 06:53:53 GMT",
"version": "v1"
},
{
"created": "Fri, 17 Oct 2014 13:30:30 GMT",
"version": "v2"
}
] | 2015-06-23 | [
[
"Ding",
"Gui-Jun",
""
],
[
"King",
"Stephen F.",
""
],
[
"Neder",
"Thomas",
""
]
] | We perform a detailed analysis of $\Delta (6n^2)$ family symmetry combined with a generalised CP symmetry in the lepton sector, breaking to different remnant symmetries $G_{\nu}$ in the neutrino and $G_{l}$ in the charged lepton sector, together with different remnant CP symmetries in each sector. We discuss the resulting mass and mixing predictions for $G_{\nu}=Z_2$ with $G_{l}=K_4,Z_p,p>2$ and $G_{\nu}=K_4$ with $G_{l}=Z_2$. All cases correspond to the preserved symmetry smaller than the full Klein symmetry, as in the semi-direct approach, leading to predictions which depend on a single undetermined real parameter, which mainly determines the reactor angle. We focus on five phenomenologically allowed cases for which we present the resulting predictions for the PMNS parameters as a function of $n$, as well as the predictions for neutrinoless double beta decay. |
2404.11642 | Evan McDonough | Stephon Alexander, Tucker Manton, and Evan McDonough | The Field Theory Axiverse | null | null | null | null | hep-ph astro-ph.CO hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Axion and axion-like particles (ALPs) are a prominent candidate for physics
beyond the Standard Model, and can play an important role in cosmology, serving
as dark matter or dark energy, or both, drawing motivation in part from the
string theory axiverse. Axion-like particles (ALPs) can also arise as composite
degrees of freedom following chiral symmetry breaking in a dark confining gauge
theory, analogous to the Standard Model (SM) pion. A dark sector with arbitrary
$N_f$ flavors of dark quarks leads to $N_f^2-1$ axion-like states, effectively
a field theory axiverse (or '$\pi$-axiverse'). A portal to the visible sector
can be achieved through the standard kinetic mixing between the dark photon and
SM photon, generating millicharges for the dark quarks and consequently
couplings, both parity-even and parity-odd, between the SM and the dark pions.
This scenario has been studied for the $N_f=2$ case and more recently for a
dark Standard Model with $N_f=6$. In this work, we study the spectrum of this
field theory axiverse for an arbitrary number of flavors, and apply this to the
example $N_f=10$. We calculate the couplings to the SM photon analogous to the
conventional axion-photon coupling, including the $N_f$ and $N_c$ dependence,
and compute the present and future constraints on the $N_f=10$, $N_c=3$,
$\pi$-axiverse. We elucidate the accompanying 'bary-verse' of superheavy dark
baryons, namely an ensemble of charged and neutral dark baryons with a mass set
by the dark pion decay constant.
| [
{
"created": "Wed, 17 Apr 2024 18:00:00 GMT",
"version": "v1"
}
] | 2024-04-19 | [
[
"Alexander",
"Stephon",
""
],
[
"Manton",
"Tucker",
""
],
[
"McDonough",
"Evan",
""
]
] | Axion and axion-like particles (ALPs) are a prominent candidate for physics beyond the Standard Model, and can play an important role in cosmology, serving as dark matter or dark energy, or both, drawing motivation in part from the string theory axiverse. Axion-like particles (ALPs) can also arise as composite degrees of freedom following chiral symmetry breaking in a dark confining gauge theory, analogous to the Standard Model (SM) pion. A dark sector with arbitrary $N_f$ flavors of dark quarks leads to $N_f^2-1$ axion-like states, effectively a field theory axiverse (or '$\pi$-axiverse'). A portal to the visible sector can be achieved through the standard kinetic mixing between the dark photon and SM photon, generating millicharges for the dark quarks and consequently couplings, both parity-even and parity-odd, between the SM and the dark pions. This scenario has been studied for the $N_f=2$ case and more recently for a dark Standard Model with $N_f=6$. In this work, we study the spectrum of this field theory axiverse for an arbitrary number of flavors, and apply this to the example $N_f=10$. We calculate the couplings to the SM photon analogous to the conventional axion-photon coupling, including the $N_f$ and $N_c$ dependence, and compute the present and future constraints on the $N_f=10$, $N_c=3$, $\pi$-axiverse. We elucidate the accompanying 'bary-verse' of superheavy dark baryons, namely an ensemble of charged and neutral dark baryons with a mass set by the dark pion decay constant. |
hep-ph/9402301 | null | Hong-Jian He, Zhaoming Qiu, Chia-Hsiung Tze | Inconsistency of QED in the Presence of Dirac Monopoles II | Pages: 8; Report#: VPI-IHEP-93-13 | Z. Phys. C65 (1995) 175 | 10.1007/BF01571318 | null | hep-ph | null | We enlarge the local gauge invariance of QED from $~U(1)_A~$ to $~U(1)_A
\times U(1)_{\Theta}~$ by introducing another unphysical pure gauge field
$~\Theta~$ with an independent, unphysical gauge coupling $~\tilde{e}~$. This
pure gauge field can be gauge-transformed away and the resulting theory is {\it
identical to} standard QED. We then re-examine the Dirac quantization condition
(DQC) for point monopoles and find that two essentially different DQCs can be
derived. One DQC involves a gauge coupling $~e~$ in the $~U(1)_A~$ group and
the other only the unphysical gauge coupling $~\tilde{e}~$ in the
$~U(1)_{\Theta}~$ group. The unique physically consistent solution of these two
DQCs is a vanishing magnetic charge, which implies that no Dirac monopole
exists in nature.
| [
{
"created": "Wed, 16 Feb 1994 19:46:35 GMT",
"version": "v1"
}
] | 2015-06-25 | [
[
"He",
"Hong-Jian",
""
],
[
"Qiu",
"Zhaoming",
""
],
[
"Tze",
"Chia-Hsiung",
""
]
] | We enlarge the local gauge invariance of QED from $~U(1)_A~$ to $~U(1)_A \times U(1)_{\Theta}~$ by introducing another unphysical pure gauge field $~\Theta~$ with an independent, unphysical gauge coupling $~\tilde{e}~$. This pure gauge field can be gauge-transformed away and the resulting theory is {\it identical to} standard QED. We then re-examine the Dirac quantization condition (DQC) for point monopoles and find that two essentially different DQCs can be derived. One DQC involves a gauge coupling $~e~$ in the $~U(1)_A~$ group and the other only the unphysical gauge coupling $~\tilde{e}~$ in the $~U(1)_{\Theta}~$ group. The unique physically consistent solution of these two DQCs is a vanishing magnetic charge, which implies that no Dirac monopole exists in nature. |
hep-ph/0109014 | Pietro Rotelli | S. De Leo (DMA-UniCamp), P. Rotelli (DF-UniLE) | Timelapse | 5 pages [2 figs], ReV-TeX | JETP Lett. 76 (2002) 56-60; Pisma Zh.Eksp.Teor.Fiz. 76 (2002)
63-67 | 10.1134/1.1507228 | null | hep-ph | null | We discuss the existence in an arbitrary frame of a finite time for the
transformation of an initial quantum state into another e.g. in a decay.
This leads to the introduction of a timelapse $\tilde{\tau}$ in analogy with
the lifetime of a particle. An argument based upon the Heisenberg uncertainty
principle suggests the value of $\tilde{\tau}=1 / M_0$. Consequences for the
exponential decay formula and the modifications that $\tilde{\tau}$ introduces
into the Breit-Wigner mass formula are described.
| [
{
"created": "Mon, 3 Sep 2001 09:44:38 GMT",
"version": "v1"
},
{
"created": "Wed, 13 Mar 2002 08:58:01 GMT",
"version": "v2"
}
] | 2015-06-25 | [
[
"De Leo",
"S.",
"",
"DMA-UniCamp"
],
[
"Rotelli",
"P.",
"",
"DF-UniLE"
]
] | We discuss the existence in an arbitrary frame of a finite time for the transformation of an initial quantum state into another e.g. in a decay. This leads to the introduction of a timelapse $\tilde{\tau}$ in analogy with the lifetime of a particle. An argument based upon the Heisenberg uncertainty principle suggests the value of $\tilde{\tau}=1 / M_0$. Consequences for the exponential decay formula and the modifications that $\tilde{\tau}$ introduces into the Breit-Wigner mass formula are described. |
hep-ph/0401163 | Durmus Demir | Durmus A. Demir | Nonlinearly Realized Local Scale Invariance: Gravity and Matter | 12pp, added a reference | Phys.Lett. B584 (2004) 133-140 | 10.1016/j.physletb.2004.01.044 | IZTECH-P01/2004 | hep-ph astro-ph gr-qc hep-th | null | That the scalar field theories with no dimensional couplings possess local
scale invariance (LSI) via the curvature gauging is utilized to show that the
Goldstone boson, released by the spontaneous LSI breakdown, is swallowed by the
spacetime curvature in order to generate Newton's constant in the same spirit
as the induction of vector boson masses via spontaneous gauge symmetry
breaking. For Einstein gravity to be reproduced correctly, the Goldstone boson
of spontaneous LSI breaking must be endowed with ghost dynamics. The matter
sector, taken to be the standard model spectrum, gains full LSI with the
physical Higgs boson acting as the Goldstone boson released by LSI breakdown at
the weak scale. The pattern of particle masses is identical to that of the
standard model. There are unitary LSI gauges in which either the Goldstone
ghost from gravity sector or the Higgs boson from matter sector is eliminated
from the spectrum. The heavy right-handed neutrinos as well as softly broken
supersymmetry naturally fit into the nonlinearly realized LSI framework.
| [
{
"created": "Thu, 22 Jan 2004 14:19:56 GMT",
"version": "v1"
},
{
"created": "Mon, 26 Jan 2004 13:29:53 GMT",
"version": "v2"
},
{
"created": "Mon, 9 Feb 2004 13:56:54 GMT",
"version": "v3"
}
] | 2009-11-10 | [
[
"Demir",
"Durmus A.",
""
]
] | That the scalar field theories with no dimensional couplings possess local scale invariance (LSI) via the curvature gauging is utilized to show that the Goldstone boson, released by the spontaneous LSI breakdown, is swallowed by the spacetime curvature in order to generate Newton's constant in the same spirit as the induction of vector boson masses via spontaneous gauge symmetry breaking. For Einstein gravity to be reproduced correctly, the Goldstone boson of spontaneous LSI breaking must be endowed with ghost dynamics. The matter sector, taken to be the standard model spectrum, gains full LSI with the physical Higgs boson acting as the Goldstone boson released by LSI breakdown at the weak scale. The pattern of particle masses is identical to that of the standard model. There are unitary LSI gauges in which either the Goldstone ghost from gravity sector or the Higgs boson from matter sector is eliminated from the spectrum. The heavy right-handed neutrinos as well as softly broken supersymmetry naturally fit into the nonlinearly realized LSI framework. |
1407.4110 | Farinaldo Queiroz | Farinaldo S. Queiroz, Kuver Sinha, William Wester | A Rich Tapestry: Supersymmetric Axions, Dark Radiation, and Inflationary
Reheating | 8 pages, 2 figures. To appear in Phys. Rev. D | Phys. Rev. D 90, 115009 (2014) | 10.1103/PhysRevD.90.115009 | CETUP2013-026 | hep-ph astro-ph.CO hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We exploit the complementarity among supersymmetry, inflation, axions, Big
Bang Nucleosynthesis (BBN) and Cosmic Microwave Background Radiation (CMB) to
constrain supersymmetric axion models in the light of the recent Planck and
BICEP results. In particular, we derive BBN bounds coming from altering the
light element abundances by taking into account hadronic and electromagnetic
energy injection, and CMB constraints from black-body spectrum distortion.
Lastly, we outline the viable versus excluded region of these supersymetric
models that might account for the mild dark radiation observed.
| [
{
"created": "Tue, 15 Jul 2014 19:48:22 GMT",
"version": "v1"
},
{
"created": "Sat, 29 Nov 2014 04:48:39 GMT",
"version": "v2"
}
] | 2014-12-17 | [
[
"Queiroz",
"Farinaldo S.",
""
],
[
"Sinha",
"Kuver",
""
],
[
"Wester",
"William",
""
]
] | We exploit the complementarity among supersymmetry, inflation, axions, Big Bang Nucleosynthesis (BBN) and Cosmic Microwave Background Radiation (CMB) to constrain supersymmetric axion models in the light of the recent Planck and BICEP results. In particular, we derive BBN bounds coming from altering the light element abundances by taking into account hadronic and electromagnetic energy injection, and CMB constraints from black-body spectrum distortion. Lastly, we outline the viable versus excluded region of these supersymetric models that might account for the mild dark radiation observed. |
hep-ph/0112359 | null | A. Kageyama, S. Kaneko, N. Shimoyama and M. Tanimoto | Lepton Flavor Violating Process in Bi-maximal texture of Neutrino
Mixings | Latex file, 38 pages, 10 figures, revised version | Phys.Rev. D65 (2002) 096010 | 10.1103/PhysRevD.65.096010 | null | hep-ph | null | We investigate the lepton flavor violation in the framework of the MSSM with
right-handed neutrinos taking the large mixing angle MSW solution in the
quasi-degenerate and the inverse-hierarchical neutrino masses. We predict the
branching ratio of $\mu \to e+\gamma$ and $\tau \to \mu+\gamma$ processes
assuming the degenerate right-handed Majorana neutrino masses. We find that the
branching ratio in the quasi-degenerate neutrino mass spectrum is 100 times
smaller than the ones in the inverse-hierarchical and the hierarchical neutrino
spectra. We emphasize that the magnitude of $U_{e3}$ is one of important
ingredients to predict BR($\mu \to e +\gamma $). The effect of the deviation
from the complete-degenerate right-handed Majorana neutrino masses are also
estimated. Furtheremore, we examine the $S_{3\sL}\times S_{3\sR}$ model, which
gives the quasi-degenerate neutrino masses, and the Shafi-Tavartkiladze model,
which gives the inverse-hierarchical neutrino masses. Both predicted branching
ratios of $\mu\to e+\gamma$ are smaller than the experimantal bound.
| [
{
"created": "Sun, 30 Dec 2001 06:20:30 GMT",
"version": "v1"
},
{
"created": "Tue, 19 Feb 2002 17:28:18 GMT",
"version": "v2"
}
] | 2016-09-06 | [
[
"Kageyama",
"A.",
""
],
[
"Kaneko",
"S.",
""
],
[
"Shimoyama",
"N.",
""
],
[
"Tanimoto",
"M.",
""
]
] | We investigate the lepton flavor violation in the framework of the MSSM with right-handed neutrinos taking the large mixing angle MSW solution in the quasi-degenerate and the inverse-hierarchical neutrino masses. We predict the branching ratio of $\mu \to e+\gamma$ and $\tau \to \mu+\gamma$ processes assuming the degenerate right-handed Majorana neutrino masses. We find that the branching ratio in the quasi-degenerate neutrino mass spectrum is 100 times smaller than the ones in the inverse-hierarchical and the hierarchical neutrino spectra. We emphasize that the magnitude of $U_{e3}$ is one of important ingredients to predict BR($\mu \to e +\gamma $). The effect of the deviation from the complete-degenerate right-handed Majorana neutrino masses are also estimated. Furtheremore, we examine the $S_{3\sL}\times S_{3\sR}$ model, which gives the quasi-degenerate neutrino masses, and the Shafi-Tavartkiladze model, which gives the inverse-hierarchical neutrino masses. Both predicted branching ratios of $\mu\to e+\gamma$ are smaller than the experimantal bound. |
1503.08645 | Jose Rodriguez-Quintero | L. Chang, C. Mezrag, H. Moutarde, C. D. Roberts, J.
Rodr\'iguez-Quintero, F. Sabati\'e | DSE inspired model for the pion's valence dressed-quark GPD | 4th Symposium on Prospects in the Physics of Discrete Symmetries
(DISCRETE 2014); CNUM: C14-12-02.1 | null | 10.1088/1742-6596/631/1/012062 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We sketch here an approach to the computation of generalised parton
distributions (GPDs), based upon a rainbow-ladder (RL) truncation of QCD's
Dyson-Schwinger equations and exemplified via the pion's valence dressed-quark
GPD, $H_\pi^{\rm v}(x,\xi,t)$. Our analysis focuses on the case of zero
skewness, $\xi=0$, and underlines that the impulse-approximation used hitherto
to define the pion's valence dressed-quark GPD is generally invalid owing to
omission of contributions from the gluons which bind dressed-quarks into the
pion. A simple correction enables us to identify a practicable improvement to
the approximation for $H_\pi^{\rm v}(x,0,t)$, expressed as the Radon transform
of a single amplitude. Therewith we obtain results for $H_\pi^{\rm v}(x,0,t)$
and the associated impact-parameter dependent distribution, $q_\pi^{\rm
v}(x,|\vec{b}_\perp|)$, which provide a qualitatively sound picture of the
pion's dressed-quark structure at an hadronic scale.
| [
{
"created": "Mon, 30 Mar 2015 11:27:12 GMT",
"version": "v1"
}
] | 2015-09-02 | [
[
"Chang",
"L.",
""
],
[
"Mezrag",
"C.",
""
],
[
"Moutarde",
"H.",
""
],
[
"Roberts",
"C. D.",
""
],
[
"Rodríguez-Quintero",
"J.",
""
],
[
"Sabatié",
"F.",
""
]
] | We sketch here an approach to the computation of generalised parton distributions (GPDs), based upon a rainbow-ladder (RL) truncation of QCD's Dyson-Schwinger equations and exemplified via the pion's valence dressed-quark GPD, $H_\pi^{\rm v}(x,\xi,t)$. Our analysis focuses on the case of zero skewness, $\xi=0$, and underlines that the impulse-approximation used hitherto to define the pion's valence dressed-quark GPD is generally invalid owing to omission of contributions from the gluons which bind dressed-quarks into the pion. A simple correction enables us to identify a practicable improvement to the approximation for $H_\pi^{\rm v}(x,0,t)$, expressed as the Radon transform of a single amplitude. Therewith we obtain results for $H_\pi^{\rm v}(x,0,t)$ and the associated impact-parameter dependent distribution, $q_\pi^{\rm v}(x,|\vec{b}_\perp|)$, which provide a qualitatively sound picture of the pion's dressed-quark structure at an hadronic scale. |
hep-ph/9804370 | Qinghui Zhang | Q. H. Zhang, X.Q. Li, C.S. Gao and W.Q. Chao | Finite coherent length and multi-pion correlation effects on two-pion
interferometry | 5 pages, two figures | J.Phys.G24:175,1998 | 10.1088/0954-3899/24/1/021 | null | hep-ph | null | The effects of multi-pion correlations and finite coherent length on two-pion
interferometry are studied. It was shown that as the pion multiplicity and
coherent length become larger, the apparent radius and the apparent coherent
parameters derived from two-pion interferometry become smaller. The influence
of the coherent length on the effective temperature is discussed.
| [
{
"created": "Thu, 23 Apr 1998 10:31:41 GMT",
"version": "v1"
}
] | 2019-08-17 | [
[
"Zhang",
"Q. H.",
""
],
[
"Li",
"X. Q.",
""
],
[
"Gao",
"C. S.",
""
],
[
"Chao",
"W. Q.",
""
]
] | The effects of multi-pion correlations and finite coherent length on two-pion interferometry are studied. It was shown that as the pion multiplicity and coherent length become larger, the apparent radius and the apparent coherent parameters derived from two-pion interferometry become smaller. The influence of the coherent length on the effective temperature is discussed. |
hep-ph/0210279 | Nicola Fabiano | Nicola Fabiano, Giulia Pancheri | Two photon width of heavy pseudoscalar mesons | To appear in the proceedings of ``First international Workshop on
Frontier Science, October 6-11, 2002 INFN Laboratory, Frascati, Italy''. 2
pages, uses frascatiphys_SP.sty | null | null | null | hep-ph | null | We discuss the partial width of the pseudoscalar charmonium state eta_c and
bottomonium state eta_b into two photons. Predictions from potential models are
examined and compared with experimental values for the eta_c case. Through the
NRQCD factorisation procedure results for eta_c are also compared with those
from J/psi data, and results for eta_b to the Upsilon decay data.
| [
{
"created": "Mon, 21 Oct 2002 12:48:13 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Fabiano",
"Nicola",
""
],
[
"Pancheri",
"Giulia",
""
]
] | We discuss the partial width of the pseudoscalar charmonium state eta_c and bottomonium state eta_b into two photons. Predictions from potential models are examined and compared with experimental values for the eta_c case. Through the NRQCD factorisation procedure results for eta_c are also compared with those from J/psi data, and results for eta_b to the Upsilon decay data. |
0910.0372 | Francesca Borzumati | F.Borzumati and T.Yamashita | The nrMSSU(5) and universality of soft masses | 4 pages, LateX, to appear in the proceedings of SUSY09, Boston, MA,
USA, 5-10 June 2009 | AIP Conf.Proc.1200:916-919,2010 | 10.1063/1.3327762 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss the problem of universality of the soft, supersymmetry-breaking
terms in the minimal supersymmetric SU(5) model (MSSU(5)) completed with
flavor-dependent nonrenormalizable operators (NROs), or nrMSSU(5). These are
exploited to correct the wrong fermion spectrum and to slow down the too-fast
decay rate of the proton that the MSSU(5) model predicts. In general, the
presence of such operators in the superpotential and K\"ahler potential gives
rise to tree-level flavor- and CP-violating entries in the sfermion mass
matrices at the cutoff scale, even when the mediation of supersymmetry (SUSY)
breaking is generation and field-type independent. We identify the conditions
under which such terms can be avoided.
| [
{
"created": "Fri, 2 Oct 2009 10:41:39 GMT",
"version": "v1"
},
{
"created": "Sun, 4 Oct 2009 14:02:01 GMT",
"version": "v2"
}
] | 2015-05-14 | [
[
"Borzumati",
"F.",
""
],
[
"Yamashita",
"T.",
""
]
] | We discuss the problem of universality of the soft, supersymmetry-breaking terms in the minimal supersymmetric SU(5) model (MSSU(5)) completed with flavor-dependent nonrenormalizable operators (NROs), or nrMSSU(5). These are exploited to correct the wrong fermion spectrum and to slow down the too-fast decay rate of the proton that the MSSU(5) model predicts. In general, the presence of such operators in the superpotential and K\"ahler potential gives rise to tree-level flavor- and CP-violating entries in the sfermion mass matrices at the cutoff scale, even when the mediation of supersymmetry (SUSY) breaking is generation and field-type independent. We identify the conditions under which such terms can be avoided. |
1208.6432 | Luigi Delle Rose | Luigi Delle Rose, Mirko Serino | Dilaton Interactions in QCD and in the Electroweak Sector of the
Standard Model | 4 pages, presented at the workshop "QCD@work", Lecce June 18-21 2012 | null | 10.1063/1.4763519 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We overview the structure of the effective action involving a dilaton and a
Higgs in the Standard Model, which has been computed recently for the neutral
currents sector. We discuss the role of the dilatation current ($J_D$) and of
an effective degree of freedom appearing in the $J_D V V'$ correlator, with $V$
any neutral current, which can be interpreted as a Nambu-Goldstone mode
generated by the anomalous breaking of the dilatation symmetry.
| [
{
"created": "Fri, 31 Aug 2012 09:15:10 GMT",
"version": "v1"
},
{
"created": "Wed, 5 Sep 2012 09:29:08 GMT",
"version": "v2"
}
] | 2015-06-11 | [
[
"Rose",
"Luigi Delle",
""
],
[
"Serino",
"Mirko",
""
]
] | We overview the structure of the effective action involving a dilaton and a Higgs in the Standard Model, which has been computed recently for the neutral currents sector. We discuss the role of the dilatation current ($J_D$) and of an effective degree of freedom appearing in the $J_D V V'$ correlator, with $V$ any neutral current, which can be interpreted as a Nambu-Goldstone mode generated by the anomalous breaking of the dilatation symmetry. |
hep-ph/0005266 | null | Somasundaram Arunagiri (U. Madras) and Hitoshi Yamamoto (U. Hawaii) | Inclusive charmless semileptonic decay of \Lambda_b and Br(b ---> X_u l
\nu_l) | Five pages (in RevTex) including a figure | null | null | UOM/NPh/HQP/00-3; UH-511-962-00 | hep-ph | null | We study the inclusive charmless semileptonic decay of $\Lambda_b$,
$\Lambda_b \to X_u l \nu_l$, in the framework of heavy quark expansion and find
that the rate is substantially enhanced by spectator effect. We obtain $Br(b
\to X_u l \nu_l)$ to be $1.13 \times 10^{-3}$ for $|V_{ub}| = 3.3 \times
10^{-3}$. We discuss our result in light of the recent LEP measurements of the
charmless semileptonic branching ratio where such enhancement was not taken
into account in extracting $|V_{ub}|$.
| [
{
"created": "Fri, 26 May 2000 05:49:23 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Arunagiri",
"Somasundaram",
"",
"U. Madras"
],
[
"Yamamoto",
"Hitoshi",
"",
"U. Hawaii"
]
] | We study the inclusive charmless semileptonic decay of $\Lambda_b$, $\Lambda_b \to X_u l \nu_l$, in the framework of heavy quark expansion and find that the rate is substantially enhanced by spectator effect. We obtain $Br(b \to X_u l \nu_l)$ to be $1.13 \times 10^{-3}$ for $|V_{ub}| = 3.3 \times 10^{-3}$. We discuss our result in light of the recent LEP measurements of the charmless semileptonic branching ratio where such enhancement was not taken into account in extracting $|V_{ub}|$. |
2111.06792 | Alessio Maiezza | Alessio Maiezza, Juan Carlos Vasquez | The QCD Adler function and the muon $g-2$ anomaly from renormalons | Updated and extended version to appear in Symmetry | Symmetry 2022, 14(9), 1878 | 10.3390/sym14091878 | null | hep-ph hep-lat hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We describe the Adler function in Quantum Chromodynamics using a transseries
representation within a resurgent framework. The approach is based on a
Borel-Ecalle resummation of the infrared renormalons combined with an effective
running for the strong coupling. The new approach is flexible enough to give
values in agreement with the current Adler function determinations. We then
apply our finding to the muon's anomalous magnetic moment studying the
possibility of saturating, solely in terms of the vacuum polarization function,
the current discrepancy between the best Standard Model value for the muon's
anomalous magnetic moment and the experimental value obtained by the most
recent muon g-2 collaboration. The latter shows that the Adler function's new
representation can also be consistent with recent lattice determinations.
| [
{
"created": "Fri, 12 Nov 2021 16:09:11 GMT",
"version": "v1"
},
{
"created": "Mon, 22 Nov 2021 15:32:11 GMT",
"version": "v2"
},
{
"created": "Mon, 5 Sep 2022 08:50:58 GMT",
"version": "v3"
}
] | 2022-09-26 | [
[
"Maiezza",
"Alessio",
""
],
[
"Vasquez",
"Juan Carlos",
""
]
] | We describe the Adler function in Quantum Chromodynamics using a transseries representation within a resurgent framework. The approach is based on a Borel-Ecalle resummation of the infrared renormalons combined with an effective running for the strong coupling. The new approach is flexible enough to give values in agreement with the current Adler function determinations. We then apply our finding to the muon's anomalous magnetic moment studying the possibility of saturating, solely in terms of the vacuum polarization function, the current discrepancy between the best Standard Model value for the muon's anomalous magnetic moment and the experimental value obtained by the most recent muon g-2 collaboration. The latter shows that the Adler function's new representation can also be consistent with recent lattice determinations. |
1803.11226 | Melahat Bayar | Natsumi Ikeno, Melahat Bayar, Eulogio Oset | Semileptonic decay of $B^{-}_c$ into $X(3930)$, $X(3940)$, $X(4160)$ | 7 pages, 9 figures | null | 10.1140/epjc/s10052-018-5898-6 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the semileptonic decay of $B^{-}_c$ meson into $\bar{\nu} l^-$ and
the isospin zero $X(3930)~(2^{++})$, $X(3940)~(0^{++})$, $X(4160)~(2^{++})$
resonances. We look at the reaction from the perspective that these resonaces
appear as dynamically generated from the vector-vector interaction in the charm
sector, and couple strongly to $D^{*}\bar{D^{*}}$ and
$D^{*}_{s}\bar{D_{s}^{*}}$. We also look into the $B^{-}_c \rightarrow
\bar{\nu}_{l} l^- D^{*}\bar{D^{*}}$ and $B^{-}_c \rightarrow \bar{\nu}_{l} l^-
D^{*}_{s}\bar{D_{s}^{*}}$ reactions close to threshold and relate the
$D^{*}\bar{D^{*}}$ and $D^{*}_{s}\bar{D_{s}^{*}}$ mass distribution to the rate
of production of the $X$ resonances.
| [
{
"created": "Thu, 29 Mar 2018 19:08:54 GMT",
"version": "v1"
}
] | 2018-07-04 | [
[
"Ikeno",
"Natsumi",
""
],
[
"Bayar",
"Melahat",
""
],
[
"Oset",
"Eulogio",
""
]
] | We study the semileptonic decay of $B^{-}_c$ meson into $\bar{\nu} l^-$ and the isospin zero $X(3930)~(2^{++})$, $X(3940)~(0^{++})$, $X(4160)~(2^{++})$ resonances. We look at the reaction from the perspective that these resonaces appear as dynamically generated from the vector-vector interaction in the charm sector, and couple strongly to $D^{*}\bar{D^{*}}$ and $D^{*}_{s}\bar{D_{s}^{*}}$. We also look into the $B^{-}_c \rightarrow \bar{\nu}_{l} l^- D^{*}\bar{D^{*}}$ and $B^{-}_c \rightarrow \bar{\nu}_{l} l^- D^{*}_{s}\bar{D_{s}^{*}}$ reactions close to threshold and relate the $D^{*}\bar{D^{*}}$ and $D^{*}_{s}\bar{D_{s}^{*}}$ mass distribution to the rate of production of the $X$ resonances. |
hep-ph/9403333 | Teruya Yamanishi | T.Morii, S.Tanaka and T.Yamanishi | A Way to Measure Polarized Gluon Distributions | LaTeX file, 6 pages+5 figures available upon request, KOBE-FHD-94-01,
Talk delivered at meeting on "Particle Physics and its Future", YITP (Japan),
Jan. 17-21, 1994 | null | null | null | hep-ph | null | Effects of the spin-dependent gluon distributions on J/$\psi$ productions in
polarized ep and pp collisions are investigated. These productions serve as a
very clean probe of the spin-dependent gluon distributions in a proton.
| [
{
"created": "Tue, 22 Mar 1994 04:53:27 GMT",
"version": "v1"
}
] | 2009-09-25 | [
[
"Morii",
"T.",
""
],
[
"Tanaka",
"S.",
""
],
[
"Yamanishi",
"T.",
""
]
] | Effects of the spin-dependent gluon distributions on J/$\psi$ productions in polarized ep and pp collisions are investigated. These productions serve as a very clean probe of the spin-dependent gluon distributions in a proton. |
1109.6520 | Susan Gardner | Susan Gardner | Superluminal Neutrinos without Revolution | 7 pages, 1 figure, SN1987A discussion modified, added comments re the
evasion of the Cohen-Glashow constraint and how c(z) can exist w/o OPERA | null | null | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The velocity anomaly recently reported by the OPERA collaboration appears
strikingly at odds with the theory of special relativity. I offer a
reinterpretation which removes this conflict, to wit that neutrinos yield a
truer measurement of Einstein's limiting speed, and that light and indeed all
other matter are retarded by additional interactions with the dark universe. I
discuss existing experimental constraints and show that such a notion,
considered cosmologically, can be subsumed in the dark-energy equation of state
in an expanding Friedman-Robertson-Walker (FRW) universe. Planned measurements
of the temporal variation in redshift have the potential to distinguish the
possibilities.
| [
{
"created": "Thu, 29 Sep 2011 13:17:09 GMT",
"version": "v1"
},
{
"created": "Tue, 4 Oct 2011 14:31:47 GMT",
"version": "v2"
},
{
"created": "Tue, 6 Dec 2011 14:17:29 GMT",
"version": "v3"
}
] | 2011-12-07 | [
[
"Gardner",
"Susan",
""
]
] | The velocity anomaly recently reported by the OPERA collaboration appears strikingly at odds with the theory of special relativity. I offer a reinterpretation which removes this conflict, to wit that neutrinos yield a truer measurement of Einstein's limiting speed, and that light and indeed all other matter are retarded by additional interactions with the dark universe. I discuss existing experimental constraints and show that such a notion, considered cosmologically, can be subsumed in the dark-energy equation of state in an expanding Friedman-Robertson-Walker (FRW) universe. Planned measurements of the temporal variation in redshift have the potential to distinguish the possibilities. |
2201.01006 | Swagata Ghosh | Swagata Ghosh | Oblique parameters of BSM models with three CP-even neutral scalars | 15 pages | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We express the oblique parameters $S$, $T$, $U$, $V$, $W$, and $X$ in terms
of the corresponding mixing matrices in the framework of three BSM models with
three CP-even neutral scalars. We consider three types of the extension of the
scalar sector of the SM with non-standard (i) two real singlet scalars, (ii)
one complex doublet and one real singlet scalar, and (iii) two complex
doublets. We present the expressions such that one can use these when all the
neutral CP-even scalars have VEV, or one of them does not have any VEV. The
principal benifit of presenting the oblique parameters in this way is, the sole
knowledge of the mixing matrices in the corresponding scalar sector is enough
to extract the expression of the oblique parameter of that particular BSM
model.
| [
{
"created": "Tue, 4 Jan 2022 06:49:05 GMT",
"version": "v1"
}
] | 2022-01-05 | [
[
"Ghosh",
"Swagata",
""
]
] | We express the oblique parameters $S$, $T$, $U$, $V$, $W$, and $X$ in terms of the corresponding mixing matrices in the framework of three BSM models with three CP-even neutral scalars. We consider three types of the extension of the scalar sector of the SM with non-standard (i) two real singlet scalars, (ii) one complex doublet and one real singlet scalar, and (iii) two complex doublets. We present the expressions such that one can use these when all the neutral CP-even scalars have VEV, or one of them does not have any VEV. The principal benifit of presenting the oblique parameters in this way is, the sole knowledge of the mixing matrices in the corresponding scalar sector is enough to extract the expression of the oblique parameter of that particular BSM model. |
hep-ph/0610372 | M. E. Carrington | M.E. Carrington | The soft fermion dispersion relation at next-to-leading order in hot QED | 15 pages, 5 figures | Phys.Rev.D75:045019,2007 | 10.1103/PhysRevD.75.045019 | null | hep-ph | null | We study next-to-leading order contributions to the soft static fermion
dispersion relation in hot QED. We derive an expression for the complete
next-to-leading order contribution to the retarded fermion self-energy. The
real and imaginary parts of this expression give the next-to-leading order
contributions to the mass and damping rate of the fermionic quasi-particle.
Many of the terms that are expected to contribute according to the traditional
power counting argument are actually subleading. We explain why the power
counting method over estimates the contribution from these terms. For the
electron damping rate in QED we obtain: $\gamma_{QED} = \frac{e^2
T}{4\pi}(2.70)$. We check our method by calculating the next-to-leading order
contribution to the damping rate for the case of QCD with two flavours and
three coulours. Our result agrees with the result obtained previously in the
literature. The numerical evaluation of the nlo contribution to the mass is
left to a future publication.
| [
{
"created": "Fri, 27 Oct 2006 16:34:47 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Carrington",
"M. E.",
""
]
] | We study next-to-leading order contributions to the soft static fermion dispersion relation in hot QED. We derive an expression for the complete next-to-leading order contribution to the retarded fermion self-energy. The real and imaginary parts of this expression give the next-to-leading order contributions to the mass and damping rate of the fermionic quasi-particle. Many of the terms that are expected to contribute according to the traditional power counting argument are actually subleading. We explain why the power counting method over estimates the contribution from these terms. For the electron damping rate in QED we obtain: $\gamma_{QED} = \frac{e^2 T}{4\pi}(2.70)$. We check our method by calculating the next-to-leading order contribution to the damping rate for the case of QCD with two flavours and three coulours. Our result agrees with the result obtained previously in the literature. The numerical evaluation of the nlo contribution to the mass is left to a future publication. |
hep-ph/9807496 | Ji-Ho Jang | Ji-Ho Jang and Pyungwon Ko | A new method for extracting the weak phase gamma from B ---> D K(*)
decays | 10 pages with 2 figures | Phys.Rev.D58:111302,1998 | 10.1103/PhysRevD.58.111302 | KAIST-14/98, SNUTP 98-079 | hep-ph | null | A new method to extract the weak phase $\gamma$ is suggested by exploiting B
---> D K^{(*)} decay modes that are not Cabibbo suppressed, using the isospin
relations, and ignoring the annihilation diagram as usual. Assuming $3 \times
10^8 B\bar{B}$ pair at $B$ factories, one can determine $\gamma$ with
$3-\sigma$ accuracy for 80^o < $\gamma$ < 150^o using B ---> D K modes and for
50^o < $\gamma$ < 170^o using B ---> D K^* modes.
| [
{
"created": "Mon, 27 Jul 1998 01:05:14 GMT",
"version": "v1"
}
] | 2009-12-30 | [
[
"Jang",
"Ji-Ho",
""
],
[
"Ko",
"Pyungwon",
""
]
] | A new method to extract the weak phase $\gamma$ is suggested by exploiting B ---> D K^{(*)} decay modes that are not Cabibbo suppressed, using the isospin relations, and ignoring the annihilation diagram as usual. Assuming $3 \times 10^8 B\bar{B}$ pair at $B$ factories, one can determine $\gamma$ with $3-\sigma$ accuracy for 80^o < $\gamma$ < 150^o using B ---> D K modes and for 50^o < $\gamma$ < 170^o using B ---> D K^* modes. |
hep-ph/9505359 | Raymond Volkas | R. Foot and R. R. Volkas | Neutrino physics and the mirror world: how exact parity symmetry
explains the solar neutrino deficit, the atmospheric neutrino anomaly and the
LSND experiment | 27 pages, LaTeX, no figures, additional discussion on big bang
nucleosynthesis, some additional references, to appear in Phys. Rev. D | Phys.Rev. D52 (1995) 6595-6606 | 10.1103/PhysRevD.52.6595 | UM-P-95/49 | hep-ph astro-ph | null | Evidence for $\bar \nu_{\mu} \rightarrow \bar \nu_e$ oscillations has been
reported at LAMPF using the LSND detector. Further evidence for neutrino mixing
comes from the solar neutrino deficit and the atmospheric neutrino anomaly. All
of these anomalies require new physics. We show that all of these anomalies can
be explained if the standard model is enlarged so that an unbroken parity
symmetry can be defined. This explanation holds independently of the actual
model for neutrino masses. Thus, we argue that parity symmetry is not only a
beautiful candidate for a symmetry beyond the standard model, but it can also
explain the known neutrino physics anomalies.
| [
{
"created": "Tue, 23 May 1995 04:21:38 GMT",
"version": "v1"
},
{
"created": "Wed, 8 Nov 1995 05:50:22 GMT",
"version": "v2"
}
] | 2009-10-28 | [
[
"Foot",
"R.",
""
],
[
"Volkas",
"R. R.",
""
]
] | Evidence for $\bar \nu_{\mu} \rightarrow \bar \nu_e$ oscillations has been reported at LAMPF using the LSND detector. Further evidence for neutrino mixing comes from the solar neutrino deficit and the atmospheric neutrino anomaly. All of these anomalies require new physics. We show that all of these anomalies can be explained if the standard model is enlarged so that an unbroken parity symmetry can be defined. This explanation holds independently of the actual model for neutrino masses. Thus, we argue that parity symmetry is not only a beautiful candidate for a symmetry beyond the standard model, but it can also explain the known neutrino physics anomalies. |
hep-ph/0006301 | Leonard Lesniak | R. Kaminski, L. Lesniak and K. Rybicki | Theoretical constraints on interaction amplitudes of light mesons | presented by L. Lesniak at the Meson 2000 Conference, Cracow, Poland,
May 19-23, 2000; 5 pages, to appear in Acta Physica Polonica B | Acta Phys.Polon. B31 (2000) 2265-2268 | null | null | hep-ph | null | We impose unitarity constraints on the S-wave isoscalar pion-pion amplitudes
extracted from the analysis of the pi- p ---> pi+ pi- n data which have been
measured by the CERN-Cracow-Munich collaboration on a transversely polarized
target at 17.2 GeV/c pi- momentum. Two "steep" solutions contain a narrow
S-wave f0(750) resonance under the rho(770) and exhibit a considerable
inelasticity eta which is in disagreement with the four pion production data
below the KKbar threshold. We impose eta= 1 for all data points and examine
four sets of solutions for the S-wave isoscalar phase-shifts. The "down-flat"
and "up-flat" solutions easily pass the eta=1 constraint but the remaining
"down-steep" and "up-steep" are eliminated. We conclude that the 17.2 GeV data
cannot be described by a relatively narrow f0(750).
| [
{
"created": "Tue, 27 Jun 2000 11:07:44 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Kaminski",
"R.",
""
],
[
"Lesniak",
"L.",
""
],
[
"Rybicki",
"K.",
""
]
] | We impose unitarity constraints on the S-wave isoscalar pion-pion amplitudes extracted from the analysis of the pi- p ---> pi+ pi- n data which have been measured by the CERN-Cracow-Munich collaboration on a transversely polarized target at 17.2 GeV/c pi- momentum. Two "steep" solutions contain a narrow S-wave f0(750) resonance under the rho(770) and exhibit a considerable inelasticity eta which is in disagreement with the four pion production data below the KKbar threshold. We impose eta= 1 for all data points and examine four sets of solutions for the S-wave isoscalar phase-shifts. The "down-flat" and "up-flat" solutions easily pass the eta=1 constraint but the remaining "down-steep" and "up-steep" are eliminated. We conclude that the 17.2 GeV data cannot be described by a relatively narrow f0(750). |
1305.0070 | Jia-Shu Lu | Chun Liu and Jia-Shu Lu | Dark Matter and Gauge Coupling Unification in A Supersymmetry Model with
Vector-like Matter | 19 pages, 1 figure. Accepted for publication in JHEP | null | 10.1007/JHEP05(2013)040 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | WIMP dark matter and gauge coupling unification are considered in an R-parity
violating MSSM with vector-like matter. Dark matter is contained in an
additional vector-like SU(2)$_L$ doublet which possesses a new U(1) gauge
symmetry. The Higgs fields are extended to be in a ${\bf 5\oplus \bar{5}}$
representation of SU(5). The stability of dark matter is a result of gauge
symmetries, and the mass of the dark matter particle is between (1.1-1.5) TeV.
Dark matter has a very small cross section with nucleis, thus the model is
consistent with current dark matter direct detection experiments such as
Xenon100. The model also predicts new charged and colored particles to be
observed at LHC.
| [
{
"created": "Wed, 1 May 2013 02:29:12 GMT",
"version": "v1"
}
] | 2013-05-14 | [
[
"Liu",
"Chun",
""
],
[
"Lu",
"Jia-Shu",
""
]
] | WIMP dark matter and gauge coupling unification are considered in an R-parity violating MSSM with vector-like matter. Dark matter is contained in an additional vector-like SU(2)$_L$ doublet which possesses a new U(1) gauge symmetry. The Higgs fields are extended to be in a ${\bf 5\oplus \bar{5}}$ representation of SU(5). The stability of dark matter is a result of gauge symmetries, and the mass of the dark matter particle is between (1.1-1.5) TeV. Dark matter has a very small cross section with nucleis, thus the model is consistent with current dark matter direct detection experiments such as Xenon100. The model also predicts new charged and colored particles to be observed at LHC. |
hep-ph/0008160 | Csaba Balazs | C. Balazs | Higgs Transverse Momentum at the LHC | 5 pages, 1 figure. Talk given at the XXXVth Rencontres de Moriond,
QCD and High Energy Hadronic Interactions, Les Arcs, France, March 18-25,
2000 | null | null | UH-511-970-00 | hep-ph | null | Resummed QCD corrections to the transverse momentum ($Q_T$) distribution of
the Standard Model Higgs boson, produced at the CERN Large Hadron Collider, are
presented. The small $Q_T$ factorization formalism is reviewed, which is used
to extend the standard hadronic factorization theorem to the low $Q_T$ region,
with emphasis on the matching to the standard hadronic factorization.
Comparison of the $Q_T$ predictions from the extended factorization and the
parton shower method is performed.
| [
{
"created": "Wed, 16 Aug 2000 04:15:07 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Balazs",
"C.",
""
]
] | Resummed QCD corrections to the transverse momentum ($Q_T$) distribution of the Standard Model Higgs boson, produced at the CERN Large Hadron Collider, are presented. The small $Q_T$ factorization formalism is reviewed, which is used to extend the standard hadronic factorization theorem to the low $Q_T$ region, with emphasis on the matching to the standard hadronic factorization. Comparison of the $Q_T$ predictions from the extended factorization and the parton shower method is performed. |
hep-ph/0410036 | David Atwood | David Atwood, Tim Gershon, Masashi Hazumi, Amarjit Soni | Mixing-Induced CP Violation in B -> P_1 P_2 gamma in Search of Clean New
Physics Signals | 13 pages 4 figures Version 4: We have added a para (2nd para below
Eqn.39, Section VII) and a new Ref. (#20) | Phys.Rev.D71:076003,2005 | 10.1103/PhysRevD.71.076003 | BNL-HET-04/18 | hep-ph hep-ex | null | We show that in a decay of the form B_d or B_s-> P_1 P_2 gamma (where P_1 and
P_2 are pseudoscalar mesons), through a flavor changing dipole transition, time
dependent oscillations can reveal the presence of physics beyond the Standard
Model. If P_1 and P_2 are CP eigenstates (e.g. as in B_d -> K_S pi0 gamma), the
oscillation is independent of the resonance structure. Thus data from
resonances as well as from nonresonant decays can be included. This may
significantly enhance the sensitivity to new physics of the method. If P_1 is a
charged particle, and P_2 its anti-particle (e.g. as in B_d -> pi+ pi- gamma),
one has the additional advantage that both the magnitude and the weak phase of
any new physics contribution can be determined from a study of the angular
distribution. These signals offer excellent ways to detect new physics because
they are suppressed in the Standard Model. We also show that the potential
contamination of these signals originating from the Standard Model annihilation
diagram gives rise to photons with, to a very good approximation, the same
helicity as the dominant penguin graph and thus causes no serious difficulty.
| [
{
"created": "Sun, 3 Oct 2004 03:04:29 GMT",
"version": "v1"
},
{
"created": "Fri, 10 Dec 2004 08:06:07 GMT",
"version": "v2"
},
{
"created": "Wed, 23 Feb 2005 19:53:50 GMT",
"version": "v3"
},
{
"created": "Thu, 24 Feb 2005 10:26:26 GMT",
"version": "v4"
}
] | 2014-11-18 | [
[
"Atwood",
"David",
""
],
[
"Gershon",
"Tim",
""
],
[
"Hazumi",
"Masashi",
""
],
[
"Soni",
"Amarjit",
""
]
] | We show that in a decay of the form B_d or B_s-> P_1 P_2 gamma (where P_1 and P_2 are pseudoscalar mesons), through a flavor changing dipole transition, time dependent oscillations can reveal the presence of physics beyond the Standard Model. If P_1 and P_2 are CP eigenstates (e.g. as in B_d -> K_S pi0 gamma), the oscillation is independent of the resonance structure. Thus data from resonances as well as from nonresonant decays can be included. This may significantly enhance the sensitivity to new physics of the method. If P_1 is a charged particle, and P_2 its anti-particle (e.g. as in B_d -> pi+ pi- gamma), one has the additional advantage that both the magnitude and the weak phase of any new physics contribution can be determined from a study of the angular distribution. These signals offer excellent ways to detect new physics because they are suppressed in the Standard Model. We also show that the potential contamination of these signals originating from the Standard Model annihilation diagram gives rise to photons with, to a very good approximation, the same helicity as the dominant penguin graph and thus causes no serious difficulty. |
1007.5049 | John F. Donoghue | John F. Donoghue, Mohamed Anber and Ufuk Aydemir | Gauge non-invariance as tests of emergent gauge symmetry | 5 pages, Invited talk presented at the Fifth Meeting on CPT and
Lorentz Symmetry, Bloomington, Indiana, June 28-July 2, 2010 | null | 10.1142/9789814327688_0022 | null | hep-ph gr-qc hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We motivate the concept of emergent gauge symmetry and discuss ways that this
concept can be tested. The key idea is that if a symmetry is emergent, one
should look for small violations of this symmetry because the underlying
fundamental theory does not contain the symmetry. We describe our recent work
implementing this idea in the gravity sector. We also describe the reasons why
violations of gauge symmetry may well be linked to violations of Lorentz
invariance.
| [
{
"created": "Wed, 28 Jul 2010 19:14:27 GMT",
"version": "v1"
}
] | 2017-08-23 | [
[
"Donoghue",
"John F.",
""
],
[
"Anber",
"Mohamed",
""
],
[
"Aydemir",
"Ufuk",
""
]
] | We motivate the concept of emergent gauge symmetry and discuss ways that this concept can be tested. The key idea is that if a symmetry is emergent, one should look for small violations of this symmetry because the underlying fundamental theory does not contain the symmetry. We describe our recent work implementing this idea in the gravity sector. We also describe the reasons why violations of gauge symmetry may well be linked to violations of Lorentz invariance. |
hep-ph/9810218 | Lori Paniak | L.D. Paniak and G.W. Semenoff | Characterizing Phases of the non-Abelian Coulomb Gas | 9 pages two column PRL, APS LaTeX, 6 eps figures, uses epsf.
Presented by G.W.S at the 5th International Workshop on Thermal Field
Theories and their Applications, Regensburg, Germany, August 10-14, 1998 | null | null | null | hep-ph | null | The thermodynamic problem of a gas of static quarks carrying U(N) charges and
interacting with each other via U(N) electric gauge fields is formulated and
solved in the large N limit. In a lattice theory, the solution can be found in
any dimension. In particular, in 1+1-dimensions, the continuum model can also
be solved. In that case, and when the quarks are in the adjoint representation,
the explicit solution exhibits a first order quark confinement-deconfinement
transition at a critical temperature and density. We also show that, when there
are fundamental representation quarks, this phase transition persists until the
relative density of fundamental quarks is comparable to the density of adjoint
quarks, where it becomes a third order transition. We discuss the possible
interpretation of the third order transition as deconfinement.
| [
{
"created": "Fri, 2 Oct 1998 01:19:12 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Paniak",
"L. D.",
""
],
[
"Semenoff",
"G. W.",
""
]
] | The thermodynamic problem of a gas of static quarks carrying U(N) charges and interacting with each other via U(N) electric gauge fields is formulated and solved in the large N limit. In a lattice theory, the solution can be found in any dimension. In particular, in 1+1-dimensions, the continuum model can also be solved. In that case, and when the quarks are in the adjoint representation, the explicit solution exhibits a first order quark confinement-deconfinement transition at a critical temperature and density. We also show that, when there are fundamental representation quarks, this phase transition persists until the relative density of fundamental quarks is comparable to the density of adjoint quarks, where it becomes a third order transition. We discuss the possible interpretation of the third order transition as deconfinement. |
hep-ph/0405063 | Vladimir Zoller | V.R. Zoller | Absorption in Ultra-Peripheral Nucleus-Atom Collisions in Crystal | 8 pages, LaTeX | JETP Lett. 79 (2004) 602-605; Pisma Zh.Eksp.Teor.Fiz. 79 (2004)
738-741 | 10.1134/1.1790015 | ITEP-PH-1/2004 | hep-ph | null | The Glauber theory description of particle- and nucleus-crystal Coulomb
interactions at high-energy is developed. The allowance for the lattice thermal
vibrations is shown to produce strong absorption effect which is of prime
importance for quantitative understanding of the coherent Coulomb excitation of
ultra-relativistic particles and nuclei passing through the crystal.
| [
{
"created": "Fri, 7 May 2004 10:48:06 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Zoller",
"V. R.",
""
]
] | The Glauber theory description of particle- and nucleus-crystal Coulomb interactions at high-energy is developed. The allowance for the lattice thermal vibrations is shown to produce strong absorption effect which is of prime importance for quantitative understanding of the coherent Coulomb excitation of ultra-relativistic particles and nuclei passing through the crystal. |
1311.5666 | Tanmoy Mondal | Joydeep Chakrabortty, Partha Konar, Tanmoy Mondal | Copositive Criteria and Boundedness of the Scalar Potential | v2 : Version to appear in PRD. Footnote and references added. 39
pages, 1 figure | Phys.Rev. D89 (2014) 095008 | 10.1103/PhysRevD.89.095008 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | To understand physics beyond the Standard Model (SM) it is important to have
the precise knowledge of Higgs boson and top quark masses as well as strong
coupling. Recently discovered new boson which is likely to be the SM Higgs with
mass 123-127 GeV has a submissive impact on the stability of the new physics
beyond standard model (BSM). The beyond standard model scenarios that include
many scalar fields posses scalar potential with many quartic couplings. Due to
the complicated structures of such scalar potentials it is indeed difficult to
adjudge the stability of the vacuum. Thus one needs to formulate a proper
prescription for computing the vacuum stability criteria. In this paper we have
used the idea of copositive matrices to deduce the conditions that guarantee
the boundedness of the scalar potential. We have discussed the basic idea
behind the copositivity and then used that to determine the vacuum stability
criteria for the Left-Right symmetric models with doublet, and triplet scalars
and Type-II seesaw. As this idea is based on the strong mathematical arguments
it helps to compute simple and unique stability criteria embracing the maximum
allowed parameter space.
| [
{
"created": "Fri, 22 Nov 2013 07:55:01 GMT",
"version": "v1"
},
{
"created": "Tue, 6 May 2014 06:01:27 GMT",
"version": "v2"
}
] | 2014-05-30 | [
[
"Chakrabortty",
"Joydeep",
""
],
[
"Konar",
"Partha",
""
],
[
"Mondal",
"Tanmoy",
""
]
] | To understand physics beyond the Standard Model (SM) it is important to have the precise knowledge of Higgs boson and top quark masses as well as strong coupling. Recently discovered new boson which is likely to be the SM Higgs with mass 123-127 GeV has a submissive impact on the stability of the new physics beyond standard model (BSM). The beyond standard model scenarios that include many scalar fields posses scalar potential with many quartic couplings. Due to the complicated structures of such scalar potentials it is indeed difficult to adjudge the stability of the vacuum. Thus one needs to formulate a proper prescription for computing the vacuum stability criteria. In this paper we have used the idea of copositive matrices to deduce the conditions that guarantee the boundedness of the scalar potential. We have discussed the basic idea behind the copositivity and then used that to determine the vacuum stability criteria for the Left-Right symmetric models with doublet, and triplet scalars and Type-II seesaw. As this idea is based on the strong mathematical arguments it helps to compute simple and unique stability criteria embracing the maximum allowed parameter space. |
1908.09100 | Manfred Kraus | Manfred Kraus, Till Martini, Sascha Peitzsch, Peter Uwer | Exploring BSM Higgs couplings in single top-quark production | 6 pages, 6 figures | null | null | HU-EP-19/21 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this article we study a Standard Model extension modifying the top-quark
Yukawa coupling to the Higgs boson by allowing a mixture of CP-odd and -even
couplings. Single top-quark production in association with an additional Higgs
boson provides a natural laboratory to search for such extensions. However,
because of the small cross section the experimental analysis is challenging.
Already the measurement of the cross section for this process is highly
non-trivial. Furthermore, using only cross section measurements, a certain
parameter region would escape detection. Using an explicit BSM scenario we show
that employing the Matrix Element Method a precise measurement becomes
feasible. Ignoring signal detection efficiencies an integrated luminosity of
about 20 fb^-1 would allow a discovery. Assuming signal detection efficiencies
at the level of a few percent a potential signal could be established in the
high luminosity phase of the LHC.
| [
{
"created": "Sat, 24 Aug 2019 06:47:53 GMT",
"version": "v1"
}
] | 2019-08-27 | [
[
"Kraus",
"Manfred",
""
],
[
"Martini",
"Till",
""
],
[
"Peitzsch",
"Sascha",
""
],
[
"Uwer",
"Peter",
""
]
] | In this article we study a Standard Model extension modifying the top-quark Yukawa coupling to the Higgs boson by allowing a mixture of CP-odd and -even couplings. Single top-quark production in association with an additional Higgs boson provides a natural laboratory to search for such extensions. However, because of the small cross section the experimental analysis is challenging. Already the measurement of the cross section for this process is highly non-trivial. Furthermore, using only cross section measurements, a certain parameter region would escape detection. Using an explicit BSM scenario we show that employing the Matrix Element Method a precise measurement becomes feasible. Ignoring signal detection efficiencies an integrated luminosity of about 20 fb^-1 would allow a discovery. Assuming signal detection efficiencies at the level of a few percent a potential signal could be established in the high luminosity phase of the LHC. |
hep-ph/0401137 | Fridger Schrempp | F. Schrempp (DESY), A. Utermann (Heidelberg U.) | Instanton-Driven Saturation at Small x | 14 pages, 9 figures | null | 10.1142/9789812702722_0026 | DESY 03-217 | hep-ph | null | We report on the interesting possibility of instanton-driven gluon saturation
in lepton-nucleon scattering at small Bjorken-x. Our results crucially involve
non-perturbative information from high-quality lattice simulations. The
conspicuous, intrinsic instanton size scale < rho > ~ 0.5 fm, as known from the
lattice, turns out to determine the saturation scale. A central result is the
identification of the ``colour glass condensate'' with the QCD-sphaleron state.
| [
{
"created": "Mon, 19 Jan 2004 17:38:25 GMT",
"version": "v1"
}
] | 2017-08-23 | [
[
"Schrempp",
"F.",
"",
"DESY"
],
[
"Utermann",
"A.",
"",
"Heidelberg U."
]
] | We report on the interesting possibility of instanton-driven gluon saturation in lepton-nucleon scattering at small Bjorken-x. Our results crucially involve non-perturbative information from high-quality lattice simulations. The conspicuous, intrinsic instanton size scale < rho > ~ 0.5 fm, as known from the lattice, turns out to determine the saturation scale. A central result is the identification of the ``colour glass condensate'' with the QCD-sphaleron state. |
hep-ph/0006320 | Antoni Szczurek | Antoni Szczurek | On the range of validity of the parton model | 2 pages, LaTeX with 1 eps figure, a talk at DIS2000, Liverpool | null | null | null | hep-ph | null | Based on the world DIS data we extract $F_2^p - F_2^n$ as a function of
Bjorken $x$ and photon virtuality $Q^2$. The standard PDFs fail to describe the
experimental data below $Q^2 <$ 7 GeV$^2$. The trend of the data is
approximately explained by our recent model.
| [
{
"created": "Wed, 28 Jun 2000 14:32:14 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Szczurek",
"Antoni",
""
]
] | Based on the world DIS data we extract $F_2^p - F_2^n$ as a function of Bjorken $x$ and photon virtuality $Q^2$. The standard PDFs fail to describe the experimental data below $Q^2 <$ 7 GeV$^2$. The trend of the data is approximately explained by our recent model. |
1206.6123 | Tseh Liou | Tseh Liou | Color-neutral heavy particle production in nucleus-nucleus collisions in
the quasi-classical approximation | 25 pages, 29 figures, v2: extended and improved discussion, a new
appendix and references added | Nuclear Physics A, 2013, 897, 122-140 | 10.1016/j.nuclphysa.2012.11.005 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We use a diagrammatic approach to study color-neutral heavy particle
production in nucleus-nucleus collisions in a quasi-classical approximation
without small-$x$ evolution. In order to treat the two nuclei symmetrically, we
use the Coulomb gauge which gives the appropriate light cone gauge for each
nucleus. The resulting cross section is factorized into a product of two
Weizs\"{a}cker-Williams gluon distributions of the two nuclei when the
transverse momentum of the produced scalar particle is around the saturation
momentum. We confirm our results in covariant gauge where the transverse
momentum broadening of hard gluons can be described as a diffusion process. The
transverse momentum factorization manifests itself in light cone gauge but not
so clearly in covariant gauge.
| [
{
"created": "Tue, 26 Jun 2012 20:55:38 GMT",
"version": "v1"
},
{
"created": "Fri, 16 Nov 2012 18:41:35 GMT",
"version": "v2"
}
] | 2012-12-07 | [
[
"Liou",
"Tseh",
""
]
] | We use a diagrammatic approach to study color-neutral heavy particle production in nucleus-nucleus collisions in a quasi-classical approximation without small-$x$ evolution. In order to treat the two nuclei symmetrically, we use the Coulomb gauge which gives the appropriate light cone gauge for each nucleus. The resulting cross section is factorized into a product of two Weizs\"{a}cker-Williams gluon distributions of the two nuclei when the transverse momentum of the produced scalar particle is around the saturation momentum. We confirm our results in covariant gauge where the transverse momentum broadening of hard gluons can be described as a diffusion process. The transverse momentum factorization manifests itself in light cone gauge but not so clearly in covariant gauge. |
1904.00018 | Jacob Ethier | Rabah Abdul Khalek, Jacob J. Ethier, and Juan Rojo | Nuclear Parton Distributions from Lepton-Nucleus Scattering and the
Impact of an Electron-Ion Collider | 50 pages, 24 figures | Eur. Phys. J. C 79 (2019) no. 3, 035201 | 10.1140/epjc/s10052-019-6983-1 | Nikhef-2019-005 | hep-ph hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a first determination of the nuclear parton distribution functions
(nPDF) based on the NNPDF methodology: nNNPDF1.0. This analysis is based on
neutral-current deep-inelastic structure function data and is performed up to
NNLO in QCD calculations with heavy quark mass effects. For the first time in
the NNPDF fits, the $\chi^2$ minimization is achieved using stochastic gradient
descent with reverse-mode automatic differentiation (backpropagation). We
validate the robustness of the fitting methodology through closure tests,
assess the perturbative stability of the resulting nPDFs, and compare them with
other recent analyses. The nNNPDF1.0 distributions satisfy the boundary
condition whereby the NNPDF3.1 proton PDF central values and uncertainties are
reproduced at $A=1$, which introduces important constraints particularly for
low-$A$ nuclei. We also investigate the information that would be provided by
an Electron-Ion Collider (EIC), finding that EIC measurements would
significantly constrain the nPDFs down to $x\simeq 5\times 10^{-4}$. Our
results represent the first-ever nPDF determination obtained using a Monte
Carlo methodology consistent with that of state-of-the-art proton PDF fits, and
provide the foundation for a subsequent global nPDF analyses including also
proton-nucleus data.
| [
{
"created": "Fri, 29 Mar 2019 18:00:02 GMT",
"version": "v1"
},
{
"created": "Thu, 4 Apr 2019 14:05:30 GMT",
"version": "v2"
},
{
"created": "Mon, 22 Jul 2019 10:04:14 GMT",
"version": "v3"
}
] | 2019-07-23 | [
[
"Khalek",
"Rabah Abdul",
""
],
[
"Ethier",
"Jacob J.",
""
],
[
"Rojo",
"Juan",
""
]
] | We present a first determination of the nuclear parton distribution functions (nPDF) based on the NNPDF methodology: nNNPDF1.0. This analysis is based on neutral-current deep-inelastic structure function data and is performed up to NNLO in QCD calculations with heavy quark mass effects. For the first time in the NNPDF fits, the $\chi^2$ minimization is achieved using stochastic gradient descent with reverse-mode automatic differentiation (backpropagation). We validate the robustness of the fitting methodology through closure tests, assess the perturbative stability of the resulting nPDFs, and compare them with other recent analyses. The nNNPDF1.0 distributions satisfy the boundary condition whereby the NNPDF3.1 proton PDF central values and uncertainties are reproduced at $A=1$, which introduces important constraints particularly for low-$A$ nuclei. We also investigate the information that would be provided by an Electron-Ion Collider (EIC), finding that EIC measurements would significantly constrain the nPDFs down to $x\simeq 5\times 10^{-4}$. Our results represent the first-ever nPDF determination obtained using a Monte Carlo methodology consistent with that of state-of-the-art proton PDF fits, and provide the foundation for a subsequent global nPDF analyses including also proton-nucleus data. |
hep-ph/0106278 | Giulia Zanderighi | A. Banfi, G. Marchesini, G. Smye, G. Zanderighi | Out-of-plane QCD radiation in hadronic Z0 production | 36 pages, 3 figures, JHEP class included | JHEP 0108:047,2001 | 10.1088/1126-6708/2001/08/047 | null | hep-ph | null | We present the QCD analysis of the cumulative out-of-event-plane momentum
distribution in the process proton-antiproton into Z0 and a hard jet (event
plane defined by the proton, antiproton and Z0 momenta). Particular attention
is placed on the near-to-planar events for which we derive the all-order
resummed result to next-to-leading accuracy. We consider also the leading power
correction originating from the fact that, even in hard processes, the resummed
QCD coupling runs into the infrared region. We aim at the same level of
accuracy which, in e+e- annihilation, seems to be sufficient for making
predictions. Contributions from a ``soft underlying event'' due to beam remnant
interactions are discussed. Experimental data (not yet available) are needed to
cast light on the predictive level of standard QCD analysis in hard
hadron-hadron collisions. We plot examples of the predicted distribution at
Tevatron energies. The techniques here developed can be extended to other hard
hadron-hadron and hadron-lepton processes.
| [
{
"created": "Mon, 25 Jun 2001 16:23:04 GMT",
"version": "v1"
}
] | 2010-02-03 | [
[
"Banfi",
"A.",
""
],
[
"Marchesini",
"G.",
""
],
[
"Smye",
"G.",
""
],
[
"Zanderighi",
"G.",
""
]
] | We present the QCD analysis of the cumulative out-of-event-plane momentum distribution in the process proton-antiproton into Z0 and a hard jet (event plane defined by the proton, antiproton and Z0 momenta). Particular attention is placed on the near-to-planar events for which we derive the all-order resummed result to next-to-leading accuracy. We consider also the leading power correction originating from the fact that, even in hard processes, the resummed QCD coupling runs into the infrared region. We aim at the same level of accuracy which, in e+e- annihilation, seems to be sufficient for making predictions. Contributions from a ``soft underlying event'' due to beam remnant interactions are discussed. Experimental data (not yet available) are needed to cast light on the predictive level of standard QCD analysis in hard hadron-hadron collisions. We plot examples of the predicted distribution at Tevatron energies. The techniques here developed can be extended to other hard hadron-hadron and hadron-lepton processes. |
hep-ph/0411016 | Sachiko Takeuchi | Sachiko Takeuchi (Japan Coll. Social Work, Tokyo) and Kiyotaka Shimizu
(Sophia U.) | Pentaquark with diquark correlations in a quark model | 8 pages, 1 figure, Talk given at International Workshop PENTAQUARK04
at SPring-8, Japan, July 20-23, 2004 | null | 10.1142/9789812701855_0038 | null | hep-ph | null | We have investigated uudd\sbar pentaquarks by employing quark models with the
meson exchange and the effective gluon exchange as qq and q\qbar interactions.
The system for five quarks is dynamically solved; two quarks are allowed to
have a diquark-like qq correlation. It is found that the lowest mass of the
pentaquark is about 1947 -- 2144 MeV. There are parameter sets where the mass
of the lowest positive-parity state become lower than that of the
negative-parity states. Which parity corresponds to the observed peak is still
an open question. Relative distance of two quarks with the attractive
interaction is found to be by about 1.2 -- 1.3 times closer than that of the
repulsive one. The diquark-like quark correlation seems to play an important
role in the pentaquark systems.
| [
{
"created": "Mon, 1 Nov 2004 12:08:23 GMT",
"version": "v1"
}
] | 2017-08-23 | [
[
"Takeuchi",
"Sachiko",
"",
"Japan Coll. Social Work, Tokyo"
],
[
"Shimizu",
"Kiyotaka",
"",
"Sophia U."
]
] | We have investigated uudd\sbar pentaquarks by employing quark models with the meson exchange and the effective gluon exchange as qq and q\qbar interactions. The system for five quarks is dynamically solved; two quarks are allowed to have a diquark-like qq correlation. It is found that the lowest mass of the pentaquark is about 1947 -- 2144 MeV. There are parameter sets where the mass of the lowest positive-parity state become lower than that of the negative-parity states. Which parity corresponds to the observed peak is still an open question. Relative distance of two quarks with the attractive interaction is found to be by about 1.2 -- 1.3 times closer than that of the repulsive one. The diquark-like quark correlation seems to play an important role in the pentaquark systems. |
1206.0894 | A. Cooper-Sarkar | Amanda Cooper-Sarkar | What did HERA teach us about the structure of the proton? | 49 pages, 49 figures, to be published in J.Phys.G | null | 10.1088/0954-3899/39/9/093001 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Starting in 2008 the H1 and ZEUS experiments have been combining their data
in order to provide the most complete and accurate set of deep-inelastic data
as the legacy of HERA. The present review presents these combinations, both
published and preliminary, and explores how they have been used to give
information on the structure of the proton. The HERAPDF parton distribution
functions (PDFs) are presented and compared with other current PDFs and with
data from the Tevatron and LHC colliders.
| [
{
"created": "Tue, 5 Jun 2012 12:03:27 GMT",
"version": "v1"
}
] | 2015-06-05 | [
[
"Cooper-Sarkar",
"Amanda",
""
]
] | Starting in 2008 the H1 and ZEUS experiments have been combining their data in order to provide the most complete and accurate set of deep-inelastic data as the legacy of HERA. The present review presents these combinations, both published and preliminary, and explores how they have been used to give information on the structure of the proton. The HERAPDF parton distribution functions (PDFs) are presented and compared with other current PDFs and with data from the Tevatron and LHC colliders. |
hep-ph/0307391 | Siannah Penaranda | A. Arhrib, M. Capdequi Peyranere, W. Hollik, S. Penaranda | Higgs decays in the Two Higgs Doublet Model: Large quantum effects in
the decoupling regime | LaTeX, 13 pages, 5 figures. Improved text, added references, appendix
removed. Version to appear in PLB | Phys.Lett. B579 (2004) 361-370 | 10.1016/j.physletb.2003.10.006 | MPP-2003-42, PM 03-21 | hep-ph | null | We study the Higgs-boson decays h0 -> b \bar{b}, h0 -> \gamma \gamma and h0
-> \gamma Z within the framework of the Two Higgs Doublet Model (THDM) in the
context of the decoupling regime, together with tree level unitarity
constraints. We show that when the light CP-even Higgs boson of the THDM mimics
the Standard-Model Higgs boson, not only the one-loop effects to h0 -> {\gamma
\gamma ,\gamma Z} but also the one-loop contribution to h0 -> b \bar{b} can be
used to distinguish between THDM and SM. The size of the quantum effects in h0
-> b \bar{b} are of the same order as in h0 -> {\gamma \gamma ,\gamma Z} and
can reach 25% in both cases.
| [
{
"created": "Thu, 31 Jul 2003 14:09:23 GMT",
"version": "v1"
},
{
"created": "Thu, 16 Oct 2003 15:04:50 GMT",
"version": "v2"
}
] | 2014-02-18 | [
[
"Arhrib",
"A.",
""
],
[
"Peyranere",
"M. Capdequi",
""
],
[
"Hollik",
"W.",
""
],
[
"Penaranda",
"S.",
""
]
] | We study the Higgs-boson decays h0 -> b \bar{b}, h0 -> \gamma \gamma and h0 -> \gamma Z within the framework of the Two Higgs Doublet Model (THDM) in the context of the decoupling regime, together with tree level unitarity constraints. We show that when the light CP-even Higgs boson of the THDM mimics the Standard-Model Higgs boson, not only the one-loop effects to h0 -> {\gamma \gamma ,\gamma Z} but also the one-loop contribution to h0 -> b \bar{b} can be used to distinguish between THDM and SM. The size of the quantum effects in h0 -> b \bar{b} are of the same order as in h0 -> {\gamma \gamma ,\gamma Z} and can reach 25% in both cases. |
2404.04168 | Oleh Fedkevych | Yang-Ting Chien, Oleh Fedkevych, Daniel Reichelt and Steffen Schumann | Jet angularities in dijet production in proton-proton and heavy-ion
collisions at RHIC | null | null | null | MCNET-24-04 IPPP/24/14 | hep-ph hep-ex nucl-ex nucl-th | http://creativecommons.org/licenses/by/4.0/ | We study jet angularities for dijet production at the Relativistic Heavy Ion
Collider (RHIC) in proton-proton (pp) and nucleus-nucleus (AA) collisions at
200 GeV nucleon-nucleon center-of-mass collision energy. In particular, we
provide $\mathrm{NLL}$ resummed predictions for angularity observables of
groomed and ungroomed jets produced in $\rm pp$ collisions matched to
next-to-leading order QCD calculations resulting in $\mathrm{NLO+NLL^\prime}$
accuracy. Our parton-level predictions are corrected for non-perturbative
effects, such as hadronization and underlying event, using parton-to-hadron
level transfer matrices obtained with the Sherpa event generator. Furthermore,
we use the Q-Pythia and JEWEL generators to estimate the impact of the
interaction between quarks and gluons produced by the parton shower with the
dense medium formed in heavy-ion collisions on the considered jet angularities.
| [
{
"created": "Fri, 5 Apr 2024 15:20:31 GMT",
"version": "v1"
}
] | 2024-04-08 | [
[
"Chien",
"Yang-Ting",
""
],
[
"Fedkevych",
"Oleh",
""
],
[
"Reichelt",
"Daniel",
""
],
[
"Schumann",
"Steffen",
""
]
] | We study jet angularities for dijet production at the Relativistic Heavy Ion Collider (RHIC) in proton-proton (pp) and nucleus-nucleus (AA) collisions at 200 GeV nucleon-nucleon center-of-mass collision energy. In particular, we provide $\mathrm{NLL}$ resummed predictions for angularity observables of groomed and ungroomed jets produced in $\rm pp$ collisions matched to next-to-leading order QCD calculations resulting in $\mathrm{NLO+NLL^\prime}$ accuracy. Our parton-level predictions are corrected for non-perturbative effects, such as hadronization and underlying event, using parton-to-hadron level transfer matrices obtained with the Sherpa event generator. Furthermore, we use the Q-Pythia and JEWEL generators to estimate the impact of the interaction between quarks and gluons produced by the parton shower with the dense medium formed in heavy-ion collisions on the considered jet angularities. |
1804.11018 | Robert Foot | R. Foot | DAMA annual modulation from electron recoils | 12 pages, matches published version | Phys. Lett. B785 (2018) 403-408 | 10.1016/j.physletb.2018.08.070 | null | hep-ph astro-ph.GA | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Plasma dark matter, which arises in dissipative dark matter models, can give
rise to large annual modulation signals from keV electron recoils. Previous
work has argued that the DAMA annual modulation signal could have an
explanation within such a scenario. However, detailed predictions are difficult
due to the inherent complexities involved in modelling the halo plasma
interactions with Earth-bound dark matter. Here, we consider a simple
phenomenological model for the dark matter velocity function relevant for
direct detection experiments, and compare the resulting electron scattering
rate with the new DAMA/LIBRA phase 2 data. We also consider the constraints
from other experiments, including XENON100 and DarkSide-50.
| [
{
"created": "Mon, 30 Apr 2018 01:52:00 GMT",
"version": "v1"
},
{
"created": "Fri, 11 May 2018 13:55:35 GMT",
"version": "v2"
},
{
"created": "Wed, 15 Aug 2018 01:50:44 GMT",
"version": "v3"
},
{
"created": "Wed, 12 Sep 2018 03:07:23 GMT",
"version": "v4"
}
] | 2018-09-13 | [
[
"Foot",
"R.",
""
]
] | Plasma dark matter, which arises in dissipative dark matter models, can give rise to large annual modulation signals from keV electron recoils. Previous work has argued that the DAMA annual modulation signal could have an explanation within such a scenario. However, detailed predictions are difficult due to the inherent complexities involved in modelling the halo plasma interactions with Earth-bound dark matter. Here, we consider a simple phenomenological model for the dark matter velocity function relevant for direct detection experiments, and compare the resulting electron scattering rate with the new DAMA/LIBRA phase 2 data. We also consider the constraints from other experiments, including XENON100 and DarkSide-50. |
hep-ph/9610384 | null | K.Dannbom, L. Ya. Glozman, C. Helminen, D. O. Riska | Baryon Magnetic Moments and Axial Coupling Constants with Relativistic
and Exchange Current Effects | Confinement exchange current contribution included, results improved,
coauthor list expanded | Nucl.Phys. A616 (1997) 555-574 | 10.1016/S0375-9474(97)81119-0 | null | hep-ph | null | The large relativistic corrections to the constituent quark current operators
improve the predictions for the axial couplings of the baryons, but worsen
those for their magnetic moments. The exchange current corrections that are
associated with flavor and spin dependent hyperfine interactions between the
quarks with a form suggested by pseudoscalar meson exchange can compensate the
relativistic corrections to the baryon magnetic moments. This is demonstrated
by a calculation of the magnetic moments of the non-strange and strange baryons
using wave functions and exchange current operators, which correspond to a
recent phenomenological spin- and flavor dependent interquark interaction model
with a linear confining interaction, which yields a spectrum close to the
empirical one. The possibility that part of the flavor and spin dependent
interaction could be due to vector and axial-vector exchange is explored.
| [
{
"created": "Thu, 17 Oct 1996 06:15:50 GMT",
"version": "v1"
},
{
"created": "Wed, 23 Oct 1996 10:50:45 GMT",
"version": "v2"
},
{
"created": "Mon, 11 Nov 1996 12:38:06 GMT",
"version": "v3"
}
] | 2009-10-30 | [
[
"Dannbom",
"K.",
""
],
[
"Glozman",
"L. Ya.",
""
],
[
"Helminen",
"C.",
""
],
[
"Riska",
"D. O.",
""
]
] | The large relativistic corrections to the constituent quark current operators improve the predictions for the axial couplings of the baryons, but worsen those for their magnetic moments. The exchange current corrections that are associated with flavor and spin dependent hyperfine interactions between the quarks with a form suggested by pseudoscalar meson exchange can compensate the relativistic corrections to the baryon magnetic moments. This is demonstrated by a calculation of the magnetic moments of the non-strange and strange baryons using wave functions and exchange current operators, which correspond to a recent phenomenological spin- and flavor dependent interquark interaction model with a linear confining interaction, which yields a spectrum close to the empirical one. The possibility that part of the flavor and spin dependent interaction could be due to vector and axial-vector exchange is explored. |
hep-ph/9908487 | Heinz Juergen Schreiber | E. Boos, V. Ilyin, A. Pukhov (Moscow State University), M. Sachwitz
and H.J. Schreiber (DESY Zeuthen) | Branching Fraction Measurements of the SM Higgs with a Mass of 160 GeV
at Future Linear \ee Colliders | 17 pages Latex, including 7 figures | Eur.Phys.J.direct C2 (2000) 5 | null | DESY 99-109 | hep-ph | null | Assuming an integrated luminosity of 500 fb$^{-1}$ and a center-of-mass
energy of 350 GeV, we examine the prospects for measuring branching fractions
of a Standard Model-like Higgs boson with a mass of 160 GeV at the future
linear \ee collider TESLA when the Higgs is produced via the Higgsstrahlung
mechanism, \ee \pfr HZ. We study in detail the precisions achievable for the
branching fractions of the Higgs into WW$^*$, ZZ$^*$ and \bb. However, the
measurement of BF(H \pfr \gaga) remains a great challence. Combined with the
expected error for the inclusive Higgsstrahlung production rate the uncertainty
for the total width of the Higgs is estimated.
| [
{
"created": "Fri, 27 Aug 1999 16:11:30 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Boos",
"E.",
"",
"Moscow State University"
],
[
"Ilyin",
"V.",
"",
"Moscow State University"
],
[
"Pukhov",
"A.",
"",
"Moscow State University"
],
[
"Sachwitz",
"M.",
"",
"DESY Zeuthen"
],
[
"Schreiber",
"H. J.",
"",
... | Assuming an integrated luminosity of 500 fb$^{-1}$ and a center-of-mass energy of 350 GeV, we examine the prospects for measuring branching fractions of a Standard Model-like Higgs boson with a mass of 160 GeV at the future linear \ee collider TESLA when the Higgs is produced via the Higgsstrahlung mechanism, \ee \pfr HZ. We study in detail the precisions achievable for the branching fractions of the Higgs into WW$^*$, ZZ$^*$ and \bb. However, the measurement of BF(H \pfr \gaga) remains a great challence. Combined with the expected error for the inclusive Higgsstrahlung production rate the uncertainty for the total width of the Higgs is estimated. |
1204.4537 | Andrej Arbuzov | M. K. Volkov, A. B. Arbuzov, D. G. Kostunin | The decay $\tau \to \pi\omega\nu$ in the extended NJL model | 5 pages | null | 10.1103/PhysRevD.86.057301 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The decay width $\tau\to\pi\omega\nu$ in the framework of the extended NJL
model is calculated. The contributions of the intermediate vector mesons
$\rho(770)$ and $\rho'(1450)$ are taken into account. The computed partial
width and the spectral function of the decay $\tau\to\pi\omega\nu$ are in
satisfactory agreement with experimental data.
| [
{
"created": "Fri, 20 Apr 2012 06:14:01 GMT",
"version": "v1"
}
] | 2013-05-30 | [
[
"Volkov",
"M. K.",
""
],
[
"Arbuzov",
"A. B.",
""
],
[
"Kostunin",
"D. G.",
""
]
] | The decay width $\tau\to\pi\omega\nu$ in the framework of the extended NJL model is calculated. The contributions of the intermediate vector mesons $\rho(770)$ and $\rho'(1450)$ are taken into account. The computed partial width and the spectral function of the decay $\tau\to\pi\omega\nu$ are in satisfactory agreement with experimental data. |
1005.2525 | Maria Cabrera | Maria Eugenia Cabrera | Bayesian Study and Naturalness in MSSM Forecast for the LHC | Presented at Recontres de Moriond EW 2010, 6-13 March 2010 | null | null | IFT-UAM/CSIC-10-36 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We perform a forecast of the CMSSM for the LHC based in an improved Bayesian
analysis taking into account the present theoretical and experimental wisdom
about the model. In this way we obtain a map of the preferred regions of the
CMSSM parameter space and show that fine-tuning penalization arises from the
Bayesian analysis itself when the experimental value of Mz is considered. The
results are remarkable stable when using different priors
| [
{
"created": "Fri, 14 May 2010 13:38:02 GMT",
"version": "v1"
}
] | 2010-05-17 | [
[
"Cabrera",
"Maria Eugenia",
""
]
] | We perform a forecast of the CMSSM for the LHC based in an improved Bayesian analysis taking into account the present theoretical and experimental wisdom about the model. In this way we obtain a map of the preferred regions of the CMSSM parameter space and show that fine-tuning penalization arises from the Bayesian analysis itself when the experimental value of Mz is considered. The results are remarkable stable when using different priors |
hep-ph/0207328 | Jose Illana | J.I. Illana and M. Masip (Granada U.) | Lepton Flavor Violation in Z and Lepton Decays in Supersymmetric Models | 23 pages, 6 figures. Version to appear in Phys. Rev. D | Phys.Rev. D67 (2003) 035004 | 10.1103/PhysRevD.67.035004 | UG-FT-137/02, CAFPE-7/02 | hep-ph | null | The observation of charged lepton flavor non-conservation would be a clear
signature of physics beyond the Standard Model. In particular, supersymmetric
(SUSY) models introduce mixings in the sneutrino and the charged slepton
sectors which could imply flavor-changing processes at rates accessible to
upcoming experiments. In this paper we analyze the possibility to observe Z -->
lep_I lep_J in the GigaZ option of TESLA at DESY. We show that although models
with SUSY masses above the current limits could predict a branching ratio BR(Z
--> mu e) accessible to the experiment, they would imply an unobserved rate of
mu --> e gamma and thus are excluded. In models with a small mixing angle
between the first and the third (or the second and the third) slepton families
GigaZ could observe Z --> tau mu (or Z --> tau e) consistently with present
bounds on lep_J --> lep_I gamma. In contrast, if the mixing angles between the
three slepton families are large the bounds from mu --> e gamma push these
processes below the reach of GigaZ. We show that in this case the masses of the
three slepton families must be strongly degenerated (with mass differences of
order 10^{-3}). We update the limits on the slepton mass insertions
delta_{LL,RR,LR} and discuss the correlation between flavor changing and g_mu-2
in SUSY models.
| [
{
"created": "Fri, 26 Jul 2002 16:42:56 GMT",
"version": "v1"
},
{
"created": "Tue, 30 Jul 2002 12:12:55 GMT",
"version": "v2"
},
{
"created": "Tue, 10 Dec 2002 14:12:53 GMT",
"version": "v3"
}
] | 2009-11-07 | [
[
"Illana",
"J. I.",
"",
"Granada U."
],
[
"Masip",
"M.",
"",
"Granada U."
]
] | The observation of charged lepton flavor non-conservation would be a clear signature of physics beyond the Standard Model. In particular, supersymmetric (SUSY) models introduce mixings in the sneutrino and the charged slepton sectors which could imply flavor-changing processes at rates accessible to upcoming experiments. In this paper we analyze the possibility to observe Z --> lep_I lep_J in the GigaZ option of TESLA at DESY. We show that although models with SUSY masses above the current limits could predict a branching ratio BR(Z --> mu e) accessible to the experiment, they would imply an unobserved rate of mu --> e gamma and thus are excluded. In models with a small mixing angle between the first and the third (or the second and the third) slepton families GigaZ could observe Z --> tau mu (or Z --> tau e) consistently with present bounds on lep_J --> lep_I gamma. In contrast, if the mixing angles between the three slepton families are large the bounds from mu --> e gamma push these processes below the reach of GigaZ. We show that in this case the masses of the three slepton families must be strongly degenerated (with mass differences of order 10^{-3}). We update the limits on the slepton mass insertions delta_{LL,RR,LR} and discuss the correlation between flavor changing and g_mu-2 in SUSY models. |
0811.1641 | Andrey Grozin | A. G. Grozin, I. B. Khriplovich, A. S. Rudenko | Electric dipole moments, from e to tau | 4 pages; v2: a typo in the formula (8) fixed, Ref. [6] updated | Phys.Atom.Nucl.72:1203-1205,2009 | 10.1134/S1063778809070138 | null | hep-ph physics.atom-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We derive an upper limit on the electric dipole moment (EDM) of the
tau-lepton, which follows from the precision measurements of the electron EDM.
| [
{
"created": "Tue, 11 Nov 2008 07:39:48 GMT",
"version": "v1"
},
{
"created": "Fri, 12 Dec 2008 10:08:39 GMT",
"version": "v2"
}
] | 2009-08-05 | [
[
"Grozin",
"A. G.",
""
],
[
"Khriplovich",
"I. B.",
""
],
[
"Rudenko",
"A. S.",
""
]
] | We derive an upper limit on the electric dipole moment (EDM) of the tau-lepton, which follows from the precision measurements of the electron EDM. |
1704.03565 | Miguel Fiolhais | S. Amor dos Santos, M.C.N. Fiolhais, R. Frederix, R. Gon\c{c}alo, E.
Gouveia, R. Martins, A. Onofre, C.M. Pease, H. Peixoto, A. Reigoto, R.
Santos, J. Silva | Probing the CP nature of the Higgs coupling in $t{\bar t}h$ events at
the LHC | 19 pages, 15 figures | Phys. Rev. D 96, 013004 (2017) | 10.1103/PhysRevD.96.013004 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The determination of the CP nature of the Higgs coupling to top quarks is
addressed in this paper, using $t{\bar t} h$ events produced in $\sqrt{s} = 13$
TeV proton-proton collisions at the LHC. Dileptonic final states are employed,
with two oppositely charged leptons and four jets, corresponding to the decays
$t\rightarrow bW^+ \rightarrow b \ell^+\nu_\ell$, $\bar{t}\rightarrow
\bar{b}W^- \rightarrow \bar{b} \ell^-\bar{\nu}_\ell$ and $h\rightarrow
b\bar{b}$. Pure scalar ($h=H$), pure pseudo-scalar ($h=A$) and CP-violating
Higgs boson signal events, generated with MadGraph5_aMC@NLO, are fully
reconstructed through a kinematic fit. We furthermore generate samples that
have both a CP-even and a CP-odd component in the $t \bar t h$ coupling in
order to probe the ratio of the two components. New angular distributions of
the decay products, as well as CP angular asymmetries, are explored in order to
separate the scalar from the pseudo-scalar components of the Higgs boson and
reduce the contribution from the dominant irreducible background, $t{\bar
t}b{\bar b}$. Significant differences between the angular distributions and
asymmetries are observed, even after the full kinematic fit reconstruction of
the events, allowing to define the best observables for a global fit of the
Higgs couplings parameters.
| [
{
"created": "Tue, 11 Apr 2017 23:01:48 GMT",
"version": "v1"
}
] | 2017-07-21 | [
[
"Santos",
"S. Amor dos",
""
],
[
"Fiolhais",
"M. C. N.",
""
],
[
"Frederix",
"R.",
""
],
[
"Gonçalo",
"R.",
""
],
[
"Gouveia",
"E.",
""
],
[
"Martins",
"R.",
""
],
[
"Onofre",
"A.",
""
],
[
"Pease",... | The determination of the CP nature of the Higgs coupling to top quarks is addressed in this paper, using $t{\bar t} h$ events produced in $\sqrt{s} = 13$ TeV proton-proton collisions at the LHC. Dileptonic final states are employed, with two oppositely charged leptons and four jets, corresponding to the decays $t\rightarrow bW^+ \rightarrow b \ell^+\nu_\ell$, $\bar{t}\rightarrow \bar{b}W^- \rightarrow \bar{b} \ell^-\bar{\nu}_\ell$ and $h\rightarrow b\bar{b}$. Pure scalar ($h=H$), pure pseudo-scalar ($h=A$) and CP-violating Higgs boson signal events, generated with MadGraph5_aMC@NLO, are fully reconstructed through a kinematic fit. We furthermore generate samples that have both a CP-even and a CP-odd component in the $t \bar t h$ coupling in order to probe the ratio of the two components. New angular distributions of the decay products, as well as CP angular asymmetries, are explored in order to separate the scalar from the pseudo-scalar components of the Higgs boson and reduce the contribution from the dominant irreducible background, $t{\bar t}b{\bar b}$. Significant differences between the angular distributions and asymmetries are observed, even after the full kinematic fit reconstruction of the events, allowing to define the best observables for a global fit of the Higgs couplings parameters. |
hep-ph/0310093 | Yukinari Sumino | Y. Sumino | Renormalon Cancellation and Perturbative QCD Potential as a
Coulomb+Linear Potential | Minor changes, References added; 11 pages, 7 figures, Talk given at
"Confinement 2003", Riken, Tokyo, July 2003 | null | 10.1142/9789812702845_0015 | TU-698 | hep-ph hep-lat hep-th | null | Recently evidence has been found that the perturbative QCD potential agrees
well with phenomenological potentials and lattice computations of the QCD
potential. We review the present status of the perturbative QCD potential and
theoretical backgrounds. We also report our recent analysis which shows
analytically, on the basis of renormalon dominance picture, that the
perturbative QCD potential quickly ``converges'' to a Coulomb-plus-linear form.
The Coulomb-plus-linear potential can be computed systematically as we include
more terms of the perturbative series; up to three-loop running (our current
best knowledge), it shows a convergence towards lattice results. e.g. At
one-loop running, the linear potential is sigma*r with sigma = (2*pi*C_F/beta0)
Lambda_MSbar^2.
| [
{
"created": "Wed, 8 Oct 2003 00:19:01 GMT",
"version": "v1"
},
{
"created": "Fri, 24 Oct 2003 04:47:52 GMT",
"version": "v2"
}
] | 2017-08-23 | [
[
"Sumino",
"Y.",
""
]
] | Recently evidence has been found that the perturbative QCD potential agrees well with phenomenological potentials and lattice computations of the QCD potential. We review the present status of the perturbative QCD potential and theoretical backgrounds. We also report our recent analysis which shows analytically, on the basis of renormalon dominance picture, that the perturbative QCD potential quickly ``converges'' to a Coulomb-plus-linear form. The Coulomb-plus-linear potential can be computed systematically as we include more terms of the perturbative series; up to three-loop running (our current best knowledge), it shows a convergence towards lattice results. e.g. At one-loop running, the linear potential is sigma*r with sigma = (2*pi*C_F/beta0) Lambda_MSbar^2. |
1102.1690 | Bilal Masud | Nosheen Akbar and Bilal Masud | Dynamical implications of gluonic excitations in meson-meson systems | 26 pages, 10 figures | Eur. Phys. J. A (2012) 48: 25 | 10.1140/epja/i2012-12025-6 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study meson-meson interactions using an extended $q^2\bar{q}^2(g)$ basis
that allows calculating coupling of an ordinary meson-meson system to a
hybrid-hybrid one. We use a potential model matrix in this extended basis which
at quark level is known to provide a good fit to numerical simulations of a
$q^2\bar{q}^2$ system in pure gluonic theory for static quarks in a selection
of geometries. We use a combination of resonating group method formalism and
Born approximation to include the quark motion using wave functions of a
$q\bar{q}$ potential within a cluster. This potential is taken to be quadratic
for ground states and has an additional smeared $\frac{1}{r}$ (Gaussian) for
the matrix elements between hybrid mesons. For the parameters of this
potential, we use values chosen to 1) minimize the error resulting from our use
of a quadratic potential and 2) best fit the lattice data for differences of
$\Sigma_{g}$ and $\Pi_{u}$ configurations of the gluonic field between a quark
and an antiquark. At the quark (static) level, including the gluonic
excitations was noted to partially replace the need for introducing many-body
terms in a multi-quark potential. We study how successful such a replacement is
at the (dynamical) hadronic level of relevance to actual hard experiments. Thus
we study effects of both gluonic excitations and many-body terms on mesonic
transition amplitudes and the energy shifts resulting from the second order
perturbation theory (i.e. from the respective hadron loops). The study suggests
introducing both energy and orbital excitations in wave functions of scalar
mesons that are modelled as meson-meson molecules or are supposed to have a
meson-meson component in their wave functions.
| [
{
"created": "Tue, 8 Feb 2011 19:08:10 GMT",
"version": "v1"
},
{
"created": "Sun, 22 May 2011 20:03:40 GMT",
"version": "v2"
},
{
"created": "Mon, 5 Mar 2012 06:35:23 GMT",
"version": "v3"
}
] | 2015-03-18 | [
[
"Akbar",
"Nosheen",
""
],
[
"Masud",
"Bilal",
""
]
] | We study meson-meson interactions using an extended $q^2\bar{q}^2(g)$ basis that allows calculating coupling of an ordinary meson-meson system to a hybrid-hybrid one. We use a potential model matrix in this extended basis which at quark level is known to provide a good fit to numerical simulations of a $q^2\bar{q}^2$ system in pure gluonic theory for static quarks in a selection of geometries. We use a combination of resonating group method formalism and Born approximation to include the quark motion using wave functions of a $q\bar{q}$ potential within a cluster. This potential is taken to be quadratic for ground states and has an additional smeared $\frac{1}{r}$ (Gaussian) for the matrix elements between hybrid mesons. For the parameters of this potential, we use values chosen to 1) minimize the error resulting from our use of a quadratic potential and 2) best fit the lattice data for differences of $\Sigma_{g}$ and $\Pi_{u}$ configurations of the gluonic field between a quark and an antiquark. At the quark (static) level, including the gluonic excitations was noted to partially replace the need for introducing many-body terms in a multi-quark potential. We study how successful such a replacement is at the (dynamical) hadronic level of relevance to actual hard experiments. Thus we study effects of both gluonic excitations and many-body terms on mesonic transition amplitudes and the energy shifts resulting from the second order perturbation theory (i.e. from the respective hadron loops). The study suggests introducing both energy and orbital excitations in wave functions of scalar mesons that are modelled as meson-meson molecules or are supposed to have a meson-meson component in their wave functions. |
hep-ph/9908282 | Marcus J. Thatcher | Marcus J. Thatcher and Michael J. Morgan | Birefringent Electroweak Textures | 10 pages | Int.J.Mod.Phys. A17 (2002) 1953-1964 | 10.1142/S0217751X02010583 | null | hep-ph | null | The behaviour of electromagnetic waves propagating through an electroweak
homilia string network is examined. This string network is topologically stable
as a cosmic texture, and is characterized by the spatial variation of the
isospin rotation of the Higgs field. As a consequence the photon field couples
to the intermediate vector bosons, producing a finite range electromagnetic
field. It is found that the propagation speed of the photon depends on its
polarization vector, whence an homilia string network acts as a birefringent
medium. We estimate the birefringent scale for this texture and show that it
depends on the frequency of the electromagnetic wave and the length scale of
the homilia string network.
| [
{
"created": "Fri, 6 Aug 1999 09:15:46 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Thatcher",
"Marcus J.",
""
],
[
"Morgan",
"Michael J.",
""
]
] | The behaviour of electromagnetic waves propagating through an electroweak homilia string network is examined. This string network is topologically stable as a cosmic texture, and is characterized by the spatial variation of the isospin rotation of the Higgs field. As a consequence the photon field couples to the intermediate vector bosons, producing a finite range electromagnetic field. It is found that the propagation speed of the photon depends on its polarization vector, whence an homilia string network acts as a birefringent medium. We estimate the birefringent scale for this texture and show that it depends on the frequency of the electromagnetic wave and the length scale of the homilia string network. |
1709.03284 | Tadashi Ishikawa | Tadashi Ishikawa (1), Nobuya Nakazawa (2) and Yoshiaki Yasui (3) ((1)
High Energy Accelerator Organization (KEK), Tsukuba Ibaraki, Japan (2)
Department of Physics, Kogakuin University, Shinjuku, Tokyo, Japan (3)
Department of Management, Tokyo Management College, Ichikawa, Chiba Japan) | Automatic calculation of two-loop ELWK corrections to the muon ($g$-2) | null | null | 10.1088/1742-6596/920/1/012009 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | Two-loop electroweak corrections to the muon anomalous magnetic moment are
automatically calculated by using GRACE-FORM system, as a trial to extend our
system for two-loop calculation. We adopt the non-linear gauge (NLG) to check
the reliability of our calculation. In total 1780 two-loop diagrams consisting
of 14 different topological types and 70 one-loop diagrams composed of counter
terms are calculated. We check UV- and IR-divergences cancellation and the
independence of the results from NLG parameters. As for the numerical
calculation, we adopt trapezoidal rule with Double Exponential method (DE).
Linear extrapolation method (LE) is introduced to regularize UV- and IR-
divergence and to get finite values.
| [
{
"created": "Mon, 11 Sep 2017 07:56:24 GMT",
"version": "v1"
},
{
"created": "Sat, 23 Sep 2017 08:02:36 GMT",
"version": "v2"
}
] | 2018-10-31 | [
[
"Ishikawa",
"Tadashi",
""
],
[
"Nakazawa",
"Nobuya",
""
],
[
"Yasui",
"Yoshiaki",
""
]
] | Two-loop electroweak corrections to the muon anomalous magnetic moment are automatically calculated by using GRACE-FORM system, as a trial to extend our system for two-loop calculation. We adopt the non-linear gauge (NLG) to check the reliability of our calculation. In total 1780 two-loop diagrams consisting of 14 different topological types and 70 one-loop diagrams composed of counter terms are calculated. We check UV- and IR-divergences cancellation and the independence of the results from NLG parameters. As for the numerical calculation, we adopt trapezoidal rule with Double Exponential method (DE). Linear extrapolation method (LE) is introduced to regularize UV- and IR- divergence and to get finite values. |
hep-ph/9503325 | null | Z. FODOR | PERTURBATIVE STUDY OF THE ELECTROWEAK PHASE TRANSITION | 3 pages, 3 figures (included), talk presented at the 27th Int. Conf.
on High Energy Physics (ICHEP), Glasgow, Scotland, 20-27 Jul 1994. | null | null | null | hep-ph | null | The electroweak phase transition is studied at finite temperature. The
effective action is given to higher orders, including wave function correction
factors and the full $g^4,\lambda^2$ effective potential. An upper bound for
the Higgs mass $m_{H} \approx 70\ GeV$ is concluded for the reliability of the
perturbative approach. A gauge invariant treatment of the phase transition is
presented.
| [
{
"created": "Tue, 14 Mar 1995 14:07:43 GMT",
"version": "v1"
}
] | 2016-09-01 | [
[
"FODOR",
"Z.",
""
]
] | The electroweak phase transition is studied at finite temperature. The effective action is given to higher orders, including wave function correction factors and the full $g^4,\lambda^2$ effective potential. An upper bound for the Higgs mass $m_{H} \approx 70\ GeV$ is concluded for the reliability of the perturbative approach. A gauge invariant treatment of the phase transition is presented. |
hep-ph/9808217 | Aoki Mayumi | Mayumi Aoki (Graduate School of Humanities and Sciences, Ochanomizu
University), Noriyuki Oshimo (Institute for Cosmic Ray Research, University
of Tokyo) | Decay Rate Asymmetry of Top Squark | 11 pages, 1 figure | Mod.Phys.Lett. A13 (1998) 3225-3234 | 10.1142/S0217732398003430 | ICRR-Report-428-98-24,OCHA-PP-119 | hep-ph | null | We discuss a decay rate asymmetry of the top squark, which is induced by a
new source of CP violation intrinsic in the supersymmetric standard model.
Although new sources of CP violation in this model are severely constrained
from the electric dipole moment of the neutron, an unsuppressed CP-violating
phase can still coexist with a top squark whose mass is accessible by
near-future colliders. Then the dominant decay mode of the top squark has a
width different from its CP conjugate process. The magnitude of this $CP$
asymmetry becomes of order $10^{-3}$.
| [
{
"created": "Tue, 4 Aug 1998 13:10:38 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Aoki",
"Mayumi",
"",
"Graduate School of Humanities and Sciences, Ochanomizu\n University"
],
[
"Oshimo",
"Noriyuki",
"",
"Institute for Cosmic Ray Research, University\n of Tokyo"
]
] | We discuss a decay rate asymmetry of the top squark, which is induced by a new source of CP violation intrinsic in the supersymmetric standard model. Although new sources of CP violation in this model are severely constrained from the electric dipole moment of the neutron, an unsuppressed CP-violating phase can still coexist with a top squark whose mass is accessible by near-future colliders. Then the dominant decay mode of the top squark has a width different from its CP conjugate process. The magnitude of this $CP$ asymmetry becomes of order $10^{-3}$. |
1408.4097 | Diptimoy Ghosh | Diptimoy Ghosh, Marco Nardecchia, S. A. Renner | Hint of Lepton Flavour Non-Universality in $B$ Meson Decays | Final version, to appear in JHEP | null | 10.1007/JHEP12(2014)131 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The LHCb collaboration has recently presented their result on R_K = BR(B+ ->
K+ mu+ mu-)/ BR(B+ -> K+ e+ e-) for the dilepton invariant mass bin m_{ll}^2 =
1-6 GeV^2 (l = mu, e). The measurement shows an intriguing 2.6 sigma deviation
from the Standard Model (SM) prediction. In view of this, we study model
independent New Physics (NP) explanations of R_K consistent with other
measurements involving b -> s l l transition, relaxing the assumption of lepton
universality. We perform a Bayesian statistical fit to the NP Wilson
Coefficients and compare the Bayes Factors of the different hypotheses in order
to quantify their goodness-of-fit. We show that the data slightly favours NP in
the muon sector over NP in the electron sector.
| [
{
"created": "Mon, 18 Aug 2014 19:01:01 GMT",
"version": "v1"
},
{
"created": "Wed, 29 Oct 2014 16:53:58 GMT",
"version": "v2"
},
{
"created": "Tue, 2 Dec 2014 10:12:02 GMT",
"version": "v3"
}
] | 2015-06-22 | [
[
"Ghosh",
"Diptimoy",
""
],
[
"Nardecchia",
"Marco",
""
],
[
"Renner",
"S. A.",
""
]
] | The LHCb collaboration has recently presented their result on R_K = BR(B+ -> K+ mu+ mu-)/ BR(B+ -> K+ e+ e-) for the dilepton invariant mass bin m_{ll}^2 = 1-6 GeV^2 (l = mu, e). The measurement shows an intriguing 2.6 sigma deviation from the Standard Model (SM) prediction. In view of this, we study model independent New Physics (NP) explanations of R_K consistent with other measurements involving b -> s l l transition, relaxing the assumption of lepton universality. We perform a Bayesian statistical fit to the NP Wilson Coefficients and compare the Bayes Factors of the different hypotheses in order to quantify their goodness-of-fit. We show that the data slightly favours NP in the muon sector over NP in the electron sector. |
hep-ph/9801241 | null | P. Ao (Umea University) | Double Counting of `Chiral Anomaly' in a Model Study of Primordial
Baryogenesis | null | null | null | null | hep-ph cond-mat | null | In this comment to the Nature paper of Bevan et al I point out that their
interpretation of experimental data is based on a double counting of the
`chiral anomaly' due to a vortex motion: using the calculation far away from
the vortex core (Berry phase) to cancel the equivalent calculation at the core
(spectral flow). The relaxation time approximation in force or momentum balance
equation involved in their theory is also wrong, which has been rigorous proved
in transport theory since 60's. Hence their affirmative conclusion is
premature.
| [
{
"created": "Thu, 8 Jan 1998 09:11:45 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Ao",
"P.",
"",
"Umea University"
]
] | In this comment to the Nature paper of Bevan et al I point out that their interpretation of experimental data is based on a double counting of the `chiral anomaly' due to a vortex motion: using the calculation far away from the vortex core (Berry phase) to cancel the equivalent calculation at the core (spectral flow). The relaxation time approximation in force or momentum balance equation involved in their theory is also wrong, which has been rigorous proved in transport theory since 60's. Hence their affirmative conclusion is premature. |
hep-ph/0203232 | Tommaso Spadaro | The KLOE Collaboration | Measurement of the branching fraction for the decay KS --> pi e nu | 9 pages, 5 Encapsulated Postscript figures. Submitted to Phys. Lett.
B | Phys.Lett.B535:37-42,2002 | 10.1016/S0370-2693(02)01733-1 | LNF-02/001 | hep-ph hep-ex | null | We present a measurement of the branching ratio BR(KS --> pi e nu) performed
using the KLOE detector. KS mesons are produced in the reaction e+ e- --> phi
--> KS KL at the DAFNE collider. In a sample of about 5 million KS-tagged
events we find 624 +- 30 semileptonic KS decays. Normalizing to the KS --> pi+
pi- count in the same data sample, we obtain BR(KS --> pi e nu) = (6.91 +-
0.37) 10^-4, in agreement with the Standard Model expectation.
| [
{
"created": "Mon, 25 Mar 2002 13:48:54 GMT",
"version": "v1"
}
] | 2012-08-27 | [
[
"The KLOE Collaboration",
"",
""
]
] | We present a measurement of the branching ratio BR(KS --> pi e nu) performed using the KLOE detector. KS mesons are produced in the reaction e+ e- --> phi --> KS KL at the DAFNE collider. In a sample of about 5 million KS-tagged events we find 624 +- 30 semileptonic KS decays. Normalizing to the KS --> pi+ pi- count in the same data sample, we obtain BR(KS --> pi e nu) = (6.91 +- 0.37) 10^-4, in agreement with the Standard Model expectation. |
2211.13949 | Alfredo Valcarce | H. Garcilazo, A. Valcarce | Hidden-flavor pentaquarks | 18 pages. Accepted for publication in Phy. Rev. D. arXiv admin note:
substantial text overlap with arXiv:2207.02757 | Physical Review D 106, 114012 (2022) | 10.1103/PhysRevD.106.114012 | null | hep-ph nucl-th | http://creativecommons.org/licenses/by/4.0/ | We have recently studied hidden-charm pentaquarks, $c\bar c qqq$, using
dynamical correlations between the heavy quarks arising from the Coulomb-like
nature of the short-range interaction. A pattern was obtained that compares
well with the experimental data. We extend our description to other flavor
sectors which can be framed within the same type of structures discussed in the
original paper. A detailed comparison is made with other results in the
literature and with experimental data. Predictions will be a useful tool to
discriminate between different models of multiquark system dynamics.
| [
{
"created": "Fri, 25 Nov 2022 08:18:55 GMT",
"version": "v1"
}
] | 2022-12-16 | [
[
"Garcilazo",
"H.",
""
],
[
"Valcarce",
"A.",
""
]
] | We have recently studied hidden-charm pentaquarks, $c\bar c qqq$, using dynamical correlations between the heavy quarks arising from the Coulomb-like nature of the short-range interaction. A pattern was obtained that compares well with the experimental data. We extend our description to other flavor sectors which can be framed within the same type of structures discussed in the original paper. A detailed comparison is made with other results in the literature and with experimental data. Predictions will be a useful tool to discriminate between different models of multiquark system dynamics. |
hep-ph/9511458 | Rogerio Rosenfeld | R. Rosenfeld (IFT), L.A. Barreiro, C.O. Escobar and M. Nielsen (USP) | Can $\Omega^- \to \Xi^- \gamma$ be sensitive to new physics beyond the
Standard Model ? | 9 pages, RevTex, no figures | Phys.Rev. D54 (1996) 3645-3648 | 10.1103/PhysRevD.54.3645 | IFT-P.061/95, IFUSP/P-1191 | hep-ph | null | We investigate the impact of new physics beyond the Standard Model to the $s
\rightarrow d \gamma$ process, which is responsible for the short-distance
contribution to the radiative decay $\Otogamma$. We study three representative
extensions of the Standard Model, namely a one-family technicolor model, a two
Higgs doublet model and a model containing scalar leptoquarks. When constraints
arising from the observed $b \to s \gamma$ transition and the upper limit on
$D^0 - \bar{D}^0$ mixing are taken into account, we find no significant
contributions of new physics to the $s \to d \gamma$ process.
| [
{
"created": "Wed, 29 Nov 1995 20:54:34 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Rosenfeld",
"R.",
"",
"IFT"
],
[
"Barreiro",
"L. A.",
"",
"USP"
],
[
"Escobar",
"C. O.",
"",
"USP"
],
[
"Nielsen",
"M.",
"",
"USP"
]
] | We investigate the impact of new physics beyond the Standard Model to the $s \rightarrow d \gamma$ process, which is responsible for the short-distance contribution to the radiative decay $\Otogamma$. We study three representative extensions of the Standard Model, namely a one-family technicolor model, a two Higgs doublet model and a model containing scalar leptoquarks. When constraints arising from the observed $b \to s \gamma$ transition and the upper limit on $D^0 - \bar{D}^0$ mixing are taken into account, we find no significant contributions of new physics to the $s \to d \gamma$ process. |
hep-ph/0008084 | Aldo Deandrea | A. Deandrea and A.D. Polosa | B->rho pi decays, resonant and nonresonant contributions | 5 pages, 2 figures, few references and minor comments added | Phys.Rev.Lett. 86 (2001) 216-219 | 10.1103/PhysRevLett.86.216 | CERN-TH/2000-242 | hep-ph | null | We point out that a new contribution to B decays to three pions is relevant
in explaining recent data from the CLEO and BABAR collaborations, in particular
the results on quasi-two-body decays via a rho meson. We also discuss the
relevance of these contribution to the measurement of CP violations.
| [
{
"created": "Wed, 9 Aug 2000 16:56:22 GMT",
"version": "v1"
},
{
"created": "Tue, 14 Nov 2000 18:58:33 GMT",
"version": "v2"
}
] | 2009-10-31 | [
[
"Deandrea",
"A.",
""
],
[
"Polosa",
"A. D.",
""
]
] | We point out that a new contribution to B decays to three pions is relevant in explaining recent data from the CLEO and BABAR collaborations, in particular the results on quasi-two-body decays via a rho meson. We also discuss the relevance of these contribution to the measurement of CP violations. |
hep-ph/0403148 | Rishikesh Vaidya | Otto C.W.Kong and Rishikesh Vaidya | Radiative B decays in Supersymmetry without R-parity | 26 pages, 13 figures. A few typos corrected and a few references
added. Contents and results unchanged | Phys.Rev. D71 (2005) 055003 | 10.1103/PhysRevD.71.055003 | NCU-HEP-k014 | hep-ph | null | We present a systematic analysis of all the contributions at the leading log
order to the branching ratio of the inclusive radiative B decay, B --> X_s +
gamma in the framework of supersymmetry without R-parity. The relevant set of
four-quark operators involved in QCD running are extended from 6 (within SM and
MSSM) to 24, with also many new contributions to the Wilson coefficients of
(chromo)magnetic penguins for either chiral structure. We present complete
analytical results here without any a priori assumptions on the form of
R-parity violation. Mass eigenstate expressions are given, hence the results
are free from the commonly adopted mass-insertion approximation. In the
numerical analysis, we focus here only on the influence of the trilinear
lambda-prime couplings and report on the possibility of a few orders of
magnitude improvement for the bounds on a few combinations of the lambda-prime
couplings. Our study shows that the Wilson coefficients of the current-current
operators due to R-parity violation dominate over the direct contributions to
the penguins. However, the inter-play of various contributions is complicated
due to the QCD corrections which we elaborate here.
| [
{
"created": "Sun, 14 Mar 2004 08:56:39 GMT",
"version": "v1"
},
{
"created": "Fri, 13 Aug 2004 09:41:00 GMT",
"version": "v2"
},
{
"created": "Tue, 16 Nov 2004 04:02:28 GMT",
"version": "v3"
}
] | 2009-11-10 | [
[
"Kong",
"Otto C. W.",
""
],
[
"Vaidya",
"Rishikesh",
""
]
] | We present a systematic analysis of all the contributions at the leading log order to the branching ratio of the inclusive radiative B decay, B --> X_s + gamma in the framework of supersymmetry without R-parity. The relevant set of four-quark operators involved in QCD running are extended from 6 (within SM and MSSM) to 24, with also many new contributions to the Wilson coefficients of (chromo)magnetic penguins for either chiral structure. We present complete analytical results here without any a priori assumptions on the form of R-parity violation. Mass eigenstate expressions are given, hence the results are free from the commonly adopted mass-insertion approximation. In the numerical analysis, we focus here only on the influence of the trilinear lambda-prime couplings and report on the possibility of a few orders of magnitude improvement for the bounds on a few combinations of the lambda-prime couplings. Our study shows that the Wilson coefficients of the current-current operators due to R-parity violation dominate over the direct contributions to the penguins. However, the inter-play of various contributions is complicated due to the QCD corrections which we elaborate here. |
0706.0771 | Vishnu Bannur M | Vishnu M. Bannur | Fully nonlinear excitations of non-Abelian plasma | 8 pages, 2 figures, article | Phys.Rev.C76:024913,2007 | 10.1103/PhysRevC.76.024913 | null | hep-ph | null | We investigate fully nonlinear, non-Abelian excitations of quark-antiquark
plasma, using relativistic fluid theory in cold plasma approximation. There are
mainly three important nonlinearities, coming from various sources such as
non-Abelian interactions of Yang-Mills (YM) fields, Wong's color dynamics and
plasma nonlinearity, in our model. By neglecting nonlinearities due to plasma
and color dynamics we get back the earlier results of Blaizot {\it et. al.},
Phys. Rev. Lett. 72, 3317 (1994). Similarly, by neglecting YM fields
nonlinearity and plasma nonlinearity, it reduces to the model of Gupta {\it et.
al.}, Phys. Lett. B498, 223 (2005). Thus we have the most general non-Abelian
mode of quark-gluon plasma (QGP). Further, our model resembles the problem of
propagation of laser beam through relativistic plasma, Physica 9D, 96 (1983).
in the absence of all non-Abelian interactions.
| [
{
"created": "Wed, 6 Jun 2007 06:09:23 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Bannur",
"Vishnu M.",
""
]
] | We investigate fully nonlinear, non-Abelian excitations of quark-antiquark plasma, using relativistic fluid theory in cold plasma approximation. There are mainly three important nonlinearities, coming from various sources such as non-Abelian interactions of Yang-Mills (YM) fields, Wong's color dynamics and plasma nonlinearity, in our model. By neglecting nonlinearities due to plasma and color dynamics we get back the earlier results of Blaizot {\it et. al.}, Phys. Rev. Lett. 72, 3317 (1994). Similarly, by neglecting YM fields nonlinearity and plasma nonlinearity, it reduces to the model of Gupta {\it et. al.}, Phys. Lett. B498, 223 (2005). Thus we have the most general non-Abelian mode of quark-gluon plasma (QGP). Further, our model resembles the problem of propagation of laser beam through relativistic plasma, Physica 9D, 96 (1983). in the absence of all non-Abelian interactions. |
hep-ph/0110370 | Carlos Bertulani | V.P. Goncalves and C.A. Bertulani | Peripheral heavy ion collisions as a probe of the nuclear gluon
distribution | 8 figures, accepted for publication in Physicsl review C | Phys.Rev. C65 (2002) 054905 | 10.1103/PhysRevC.65.054905 | null | hep-ph nucl-th | null | At high energies a quark-gluon plasma is expected to be formed in heavy ion
collisions at RHIC and LHC. The theoretical description of these processes is
directly associated to a complete knowledge of the details of medium effects in
the nuclear gluon distribution. In this paper we analyze the possibility to
constraint the behavior of this distribution considering peripheral heavy ion
collisions. We reanalyze the photoproduction of heavy quarks for the deduction
of the in-medium gluon distribution using three current parameterizations for
this parton distribution. Moreover, we show that the elastic photoproduction of
vector mesons is a potential process to probe the nuclear gluon distribution.
| [
{
"created": "Mon, 29 Oct 2001 15:47:04 GMT",
"version": "v1"
},
{
"created": "Tue, 30 Oct 2001 16:00:12 GMT",
"version": "v2"
},
{
"created": "Thu, 14 Mar 2002 19:24:05 GMT",
"version": "v3"
}
] | 2009-11-07 | [
[
"Goncalves",
"V. P.",
""
],
[
"Bertulani",
"C. A.",
""
]
] | At high energies a quark-gluon plasma is expected to be formed in heavy ion collisions at RHIC and LHC. The theoretical description of these processes is directly associated to a complete knowledge of the details of medium effects in the nuclear gluon distribution. In this paper we analyze the possibility to constraint the behavior of this distribution considering peripheral heavy ion collisions. We reanalyze the photoproduction of heavy quarks for the deduction of the in-medium gluon distribution using three current parameterizations for this parton distribution. Moreover, we show that the elastic photoproduction of vector mesons is a potential process to probe the nuclear gluon distribution. |
hep-ph/9211332 | Ahmady Mohammad | Mohammad R. Ahmady and Dongsheng Liu | Exclusive Decays $B \rightarrow K \psi , B \rightarrow K^* \psi $ using
Heavy Quark Symmetries | 7 pages | Phys.Lett.B302:491-494,1993 | 10.1016/0370-2693(93)90431-G | null | hep-ph | null | We use the new symmetries in the heavy quark limit to calculate the exclusive
B-decays $B \rightarrow K \psi ({\psi}^{\prime})$ and $B \rightarrow K^* \psi
({\psi}^{\prime})$. The estimated decay rates are compared with experimental
values. We also estimate rare $B \rightarrow K^* \gamma $ decay rate, based on
these experimental data and heavy quark symmetry.
| [
{
"created": "Mon, 30 Nov 1992 14:19:26 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"Ahmady",
"Mohammad R.",
""
],
[
"Liu",
"Dongsheng",
""
]
] | We use the new symmetries in the heavy quark limit to calculate the exclusive B-decays $B \rightarrow K \psi ({\psi}^{\prime})$ and $B \rightarrow K^* \psi ({\psi}^{\prime})$. The estimated decay rates are compared with experimental values. We also estimate rare $B \rightarrow K^* \gamma $ decay rate, based on these experimental data and heavy quark symmetry. |
0809.4853 | Carl E. Carlson | Carl E. Carlson (William and Mary) | Hadron Form Factors in AdS/QCD | Invited talk at the Eighth International Conference on Hyperons,
Charm and Beauty Hadrons (BEACH 2008), Columbia, SC, USA, 22--28 June 2008 | null | 10.1016/j.nuclphysbps.2009.01.027 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss how to calculate form factors using a holographic model of QCD,
mainly focusing on vector, axial, and pseudoscalar mesons. We illustrate the
techniques on gravitational form factors (which are useful for constraining the
generalized parton distributions) as well as quoting the results for
electromagnetic form factors. One striking outcome, comparing the several types
of calculated form factors, is that mesons appear noticeably more compact when
measured by the gravitational form factors than when measured by the charge
form factor.
| [
{
"created": "Sun, 28 Sep 2008 16:19:01 GMT",
"version": "v1"
}
] | 2009-11-13 | [
[
"Carlson",
"Carl E.",
"",
"William and Mary"
]
] | We discuss how to calculate form factors using a holographic model of QCD, mainly focusing on vector, axial, and pseudoscalar mesons. We illustrate the techniques on gravitational form factors (which are useful for constraining the generalized parton distributions) as well as quoting the results for electromagnetic form factors. One striking outcome, comparing the several types of calculated form factors, is that mesons appear noticeably more compact when measured by the gravitational form factors than when measured by the charge form factor. |
hep-ph/0403290 | Dieter Gromes | Dieter Gromes | Singular behavior of ^1P_1^{+-} quarkonium and positronium annihilation
decays and relevance of relative energy | 13 pages, 2 figures, errors corrected | Eur.Phys.J.C36:169-175,2004 | 10.1140/epjc/s2004-01966-2 | HD-THEP-04-12 | hep-ph | null | Using a four dimensional approach, we show that the singularities for small
gluon momenta, which arise in the usual three dimensional treatment of the
annihilation decay, disappear if all poles in the relative energy are taken
into account correctly in the integration. We obtain an explicit formula for
the decay width which involves a non locality originating from the kinetic
energy. We calculate not only the familiar logarithmic dependence on the
binding energy, but also the constant to be added to the logarithm. For
positronium this differs from an earlier result in the literature and leads to
a modified life time. In QCD there is a non abelian loop graph which
contributes to the decay amplitude to the same order as the tree graph.
Contrary to the original version, which contained some errors, the constant
turns out to be large and negative.
For reasonable parameters, this negative constant practically cancels the
positive logarithm, so that the whole approach of expanding with respect to the
binding energy breaks down.
| [
{
"created": "Tue, 30 Mar 2004 14:47:31 GMT",
"version": "v1"
},
{
"created": "Thu, 3 Mar 2005 13:34:52 GMT",
"version": "v2"
}
] | 2011-07-19 | [
[
"Gromes",
"Dieter",
""
]
] | Using a four dimensional approach, we show that the singularities for small gluon momenta, which arise in the usual three dimensional treatment of the annihilation decay, disappear if all poles in the relative energy are taken into account correctly in the integration. We obtain an explicit formula for the decay width which involves a non locality originating from the kinetic energy. We calculate not only the familiar logarithmic dependence on the binding energy, but also the constant to be added to the logarithm. For positronium this differs from an earlier result in the literature and leads to a modified life time. In QCD there is a non abelian loop graph which contributes to the decay amplitude to the same order as the tree graph. Contrary to the original version, which contained some errors, the constant turns out to be large and negative. For reasonable parameters, this negative constant practically cancels the positive logarithm, so that the whole approach of expanding with respect to the binding energy breaks down. |
2403.12914 | Andr\'e Milagre | Andr\'e Milagre and Lu\'is Lavoura | Unitarity constraints on large multiplets of arbitrary gauge groups | 29 pages, 4 figures, 10 tables | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We impose partial-wave unitarity on $2 \to 2$ tree-level scattering processes
to derive constraints on the dimensions of large scalar and fermionic
multiplets of arbitrary gauge groups. We apply our results to scalar and
fermionic extensions of the Standard Model, and also to the Grand Unified
Theories (GUTs) based on the groups $SU(5)$, $SO(10)$, and $E_6$. We find
scenarios within the latter two GUTs that violate the unitarity condition; this
may require a reevaluation of the validity of perturbation theory in those
scenarios.
| [
{
"created": "Tue, 19 Mar 2024 17:12:43 GMT",
"version": "v1"
},
{
"created": "Wed, 3 Apr 2024 16:38:13 GMT",
"version": "v2"
}
] | 2024-04-04 | [
[
"Milagre",
"André",
""
],
[
"Lavoura",
"Luís",
""
]
] | We impose partial-wave unitarity on $2 \to 2$ tree-level scattering processes to derive constraints on the dimensions of large scalar and fermionic multiplets of arbitrary gauge groups. We apply our results to scalar and fermionic extensions of the Standard Model, and also to the Grand Unified Theories (GUTs) based on the groups $SU(5)$, $SO(10)$, and $E_6$. We find scenarios within the latter two GUTs that violate the unitarity condition; this may require a reevaluation of the validity of perturbation theory in those scenarios. |
hep-ph/0003030 | Kimball A. Milton | K. A. Milton, I. L. Solovtsov, O. P.Solovtsova, V. I. Yasnov | Renormalization Scheme and Higher Loop Stability in Hadronic $\tau$
Decay within Analytic Perturbation Theory | 15 pages, 2 eps figures, revtex | Eur.Phys.J.C14:495-501,2000 | 10.1007/s100520000370 | null | hep-ph | null | We apply an analytic description to the inclusive decay of the $\tau$ lepton.
We argue that this method gives not only a self-consistent description of the
process both in the timelike region by using the initial expression for
$R_\tau$ and in the spacelike domain by using the analytic properties of the
hadronic correlator, but also leads to the fact that theoretical uncertainties
associated with unknown higher-loop contributions and renormalization scheme
dependence can be reduced dramatically.
| [
{
"created": "Fri, 3 Mar 2000 23:08:38 GMT",
"version": "v1"
}
] | 2011-09-13 | [
[
"Milton",
"K. A.",
""
],
[
"Solovtsov",
"I. L.",
""
],
[
"Solovtsova",
"O. P.",
""
],
[
"Yasnov",
"V. I.",
""
]
] | We apply an analytic description to the inclusive decay of the $\tau$ lepton. We argue that this method gives not only a self-consistent description of the process both in the timelike region by using the initial expression for $R_\tau$ and in the spacelike domain by using the analytic properties of the hadronic correlator, but also leads to the fact that theoretical uncertainties associated with unknown higher-loop contributions and renormalization scheme dependence can be reduced dramatically. |
1111.3534 | Slava Rychkov | Axel Orgogozo, Slava Rychkov | Exploring T and S parameters in Vector Meson Dominance Models of Strong
Electroweak Symmetry Breaking | 35 pages, 7 figures; v3: refs added, to appear in JHEP | null | 10.1007/JHEP03(2012)046 | LPTENS-11/41 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We revisit the electroweak precision tests for Higgsless models of strong
EWSB. We use the Vector Meson Dominance approach and express S and T via
couplings characterizing vector and axial spin-1 resonances of the strong
sector. These couplings are constrained by the elastic unitarity and by
requiring a good UV behavior of various formfactors. We pay particular
attention to the one-loop contribution of resonances to T (beyond the chiral
log), and to how it can improve the fit. We also make contact with the recent
studies of Conformal Technicolor. We explain why the second Weinberg sum rule
never converges in these models, and formulate a condition necessary for
preserving the custodial symmetry in the IR.
| [
{
"created": "Tue, 15 Nov 2011 14:34:39 GMT",
"version": "v1"
},
{
"created": "Wed, 4 Jan 2012 17:24:38 GMT",
"version": "v2"
},
{
"created": "Wed, 15 Feb 2012 20:14:17 GMT",
"version": "v3"
}
] | 2015-06-03 | [
[
"Orgogozo",
"Axel",
""
],
[
"Rychkov",
"Slava",
""
]
] | We revisit the electroweak precision tests for Higgsless models of strong EWSB. We use the Vector Meson Dominance approach and express S and T via couplings characterizing vector and axial spin-1 resonances of the strong sector. These couplings are constrained by the elastic unitarity and by requiring a good UV behavior of various formfactors. We pay particular attention to the one-loop contribution of resonances to T (beyond the chiral log), and to how it can improve the fit. We also make contact with the recent studies of Conformal Technicolor. We explain why the second Weinberg sum rule never converges in these models, and formulate a condition necessary for preserving the custodial symmetry in the IR. |
hep-ph/0107091 | F. Cano | F. Cano and J.-M. Laget | Quark correlations and gluon propagators in elastic vector meson
production | 4 pages, 2 figures, espcrc1.sty included, Proceedings of the Third
International Conference on Perspectives in Hadronic Physics | Nucl.Phys. A699 (2002) 356-359 | 10.1016/S0375-9474(01)01520-2 | DAPNIA/SPHN-01-24 | hep-ph nucl-th | null | We study the behavior of the differential cross section for vector meson
photoproduction at large momentum transfer in the two-gluon exchange model. We
focus on the treatment of two-quark correlation function in the proton and on
gluon propagators with a dynamically generated mass. We find that only the
large t region is sensitive to the particular details of these inputs.
| [
{
"created": "Mon, 9 Jul 2001 14:38:34 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Cano",
"F.",
""
],
[
"Laget",
"J. -M.",
""
]
] | We study the behavior of the differential cross section for vector meson photoproduction at large momentum transfer in the two-gluon exchange model. We focus on the treatment of two-quark correlation function in the proton and on gluon propagators with a dynamically generated mass. We find that only the large t region is sensitive to the particular details of these inputs. |
0804.1922 | Boris Ermolaev | B.I. Ermolaev, M. Greco, S.I. Troyan | Comment on the recent COMPASS data on the spin structure function g_1 | 8 pages, 1 figure | Eur.Phys.J.C58:29-35,2008 | 10.1140/epjc/s10052-008-0739-7 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We examine the recent COMPASS data on the spin structure function g_1
singlet. We show that it is rather difficult to use the data in the present
form in order to draw conclusions on the initial parton densities. However, our
tentative estimate is that the data better agree with positive rather than
negative initial gluon densities.
| [
{
"created": "Fri, 11 Apr 2008 15:51:32 GMT",
"version": "v1"
},
{
"created": "Thu, 12 Jun 2008 09:56:11 GMT",
"version": "v2"
}
] | 2010-03-25 | [
[
"Ermolaev",
"B. I.",
""
],
[
"Greco",
"M.",
""
],
[
"Troyan",
"S. I.",
""
]
] | We examine the recent COMPASS data on the spin structure function g_1 singlet. We show that it is rather difficult to use the data in the present form in order to draw conclusions on the initial parton densities. However, our tentative estimate is that the data better agree with positive rather than negative initial gluon densities. |
1403.4616 | Claude Duhr | Charalampos Anastasiou, Claude Duhr, Falko Dulat, Elisabetta Furlan,
Thomas Gehrmann, Franz Herzog, Bernhard Mistlberger | Higgs boson gluon-fusion production at threshold in N3LO QCD | 4 pages, 1 figure | null | 10.1016/j.physletb.2014.08.067 | IPPP/14/17, DCPT/14/34, ZU-TH 07/14, CERN-PH-TH/2014-042,
FERMILAB-PUB-14-052-T | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the cross-section for the threshold production of the Higgs boson
at hadron-colliders at next-to-next-to-next-to-leading order (N3LO) in
perturbative QCD. We present an analytic expression for the partonic
cross-section at threshold and the impact of these corrections on the numerical
estimates for the hadronic cross-section at the LHC. With this result we
achieve a major milestone towards a complete evaluation of the cross-section at
N3LO which will reduce the theoretical uncertainty in the determination of the
strengths of the Higgs boson interactions.
| [
{
"created": "Tue, 18 Mar 2014 20:22:51 GMT",
"version": "v1"
}
] | 2015-06-19 | [
[
"Anastasiou",
"Charalampos",
""
],
[
"Duhr",
"Claude",
""
],
[
"Dulat",
"Falko",
""
],
[
"Furlan",
"Elisabetta",
""
],
[
"Gehrmann",
"Thomas",
""
],
[
"Herzog",
"Franz",
""
],
[
"Mistlberger",
"Bernhard",
"... | We present the cross-section for the threshold production of the Higgs boson at hadron-colliders at next-to-next-to-next-to-leading order (N3LO) in perturbative QCD. We present an analytic expression for the partonic cross-section at threshold and the impact of these corrections on the numerical estimates for the hadronic cross-section at the LHC. With this result we achieve a major milestone towards a complete evaluation of the cross-section at N3LO which will reduce the theoretical uncertainty in the determination of the strengths of the Higgs boson interactions. |
1912.13284 | Xin Wang | Xin Wang | Lepton Flavor Mixing and CP Violation in the Minimal Type-(I+II) Seesaw
Model with a Modular $A_4$ Symmetry | 25 pages, 5 figures. Matches version published in NPB. arXiv admin
note: text overlap with arXiv:1910.09473 | null | 10.1016/j.nuclphysb.2020.115105 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper, we study the implications of the modular $A^{}_4$ flavor
symmetry in constructing a supersymmetric minimal type-(I+II) seesaw model, in
which only one right-handed neutrino and two Higgs triplets are introduced to
account for the tiny neutrino masses, flavor mixing and CP violation. The
right-handed neutrino as well as the Higgs triplets in this model are assigned
into the trivial one-dimensional irreducible representation of the modular
group $A^{}_{4}$. We show that the individual contributions to the neutrino
masses from the right-handed neutrino and the Higgs triplet are comparable. We
also find that the neutrino mass matrix can possess an approximate $\mu-\tau$
reflection symmetry for some specific values of free model parameters.
Moreover, our model predicts relatively large masses of three light neutrinos,
thus can be easily tested in future neutrino experiments.
| [
{
"created": "Tue, 31 Dec 2019 12:13:26 GMT",
"version": "v1"
},
{
"created": "Sun, 12 Jul 2020 05:28:09 GMT",
"version": "v2"
}
] | 2020-08-26 | [
[
"Wang",
"Xin",
""
]
] | In this paper, we study the implications of the modular $A^{}_4$ flavor symmetry in constructing a supersymmetric minimal type-(I+II) seesaw model, in which only one right-handed neutrino and two Higgs triplets are introduced to account for the tiny neutrino masses, flavor mixing and CP violation. The right-handed neutrino as well as the Higgs triplets in this model are assigned into the trivial one-dimensional irreducible representation of the modular group $A^{}_{4}$. We show that the individual contributions to the neutrino masses from the right-handed neutrino and the Higgs triplet are comparable. We also find that the neutrino mass matrix can possess an approximate $\mu-\tau$ reflection symmetry for some specific values of free model parameters. Moreover, our model predicts relatively large masses of three light neutrinos, thus can be easily tested in future neutrino experiments. |
hep-ph/9403380 | Thomas Meissner | Chuan-Tsung Chan, E.M.Henley and Th.Meissner | Pi- Eta Mixing from QCD Sum Rules | 14 pages (written in REVTEX) + 1 fig. (available as hardcopy only on
request), preprint no.DOE/ER/40561-133-INT94-0053 | Phys.Lett. B343 (1995) 7-12 | 10.1016/0370-2693(94)01461-K | null | hep-ph nucl-th | null | The $q^2$ dependence of the $\pi$-$\eta$ mixing amplitude is examined with
the use of QCD sum rules. The linear slope of the mixing function $\theta(q^2)$
is found to be much smaller than that for $\rho$-$\omega$ mixing. Thus the
mixing amplitude is approximately the same in the space-like region as in the
time-like one, and one may neglect the $q^2$ dependence of the mixing. A
comparison between a hadron-meson, an effective chiral model, and the QCD sum
rules approaches is made.
| [
{
"created": "Mon, 28 Mar 1994 22:45:40 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Chan",
"Chuan-Tsung",
""
],
[
"Henley",
"E. M.",
""
],
[
"Meissner",
"Th.",
""
]
] | The $q^2$ dependence of the $\pi$-$\eta$ mixing amplitude is examined with the use of QCD sum rules. The linear slope of the mixing function $\theta(q^2)$ is found to be much smaller than that for $\rho$-$\omega$ mixing. Thus the mixing amplitude is approximately the same in the space-like region as in the time-like one, and one may neglect the $q^2$ dependence of the mixing. A comparison between a hadron-meson, an effective chiral model, and the QCD sum rules approaches is made. |
1206.7055 | Thomas G. Rizzo | Thomas G. Rizzo | Possible Suppression of Resonant Signals for Split-UED by Mixing at the
LHC? | 10 pages, 2 figures; discussion and references added | null | 10.1103/PhysRevD.86.055024 | SLAC-PUB-14954 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The mixing of the imaginary parts of the transition amplitudes of nearby
resonances via the breakdown of the Breit-Wigner approximation has been shown
to lead to potentially large modifications in the signal rates for new physics
at colliders. In the case of suppression, this effect may be significant enough
to lead to some new physics signatures being initially missed in searches at,
e.g., the LHC. Here we explore the influence of this `width mixing' on the
production of the nearly degenerate, level-2 Kaluza-Klein (KK) neutral gauge
bosons present in Split-UED. We demonstrate that in this particular case large
cross section modifications in the resonance region are necessarily absent and
explain why this is so based on the group theoretical structure of the SM.
| [
{
"created": "Fri, 29 Jun 2012 15:32:18 GMT",
"version": "v1"
},
{
"created": "Mon, 13 Aug 2012 14:21:59 GMT",
"version": "v2"
}
] | 2013-05-30 | [
[
"Rizzo",
"Thomas G.",
""
]
] | The mixing of the imaginary parts of the transition amplitudes of nearby resonances via the breakdown of the Breit-Wigner approximation has been shown to lead to potentially large modifications in the signal rates for new physics at colliders. In the case of suppression, this effect may be significant enough to lead to some new physics signatures being initially missed in searches at, e.g., the LHC. Here we explore the influence of this `width mixing' on the production of the nearly degenerate, level-2 Kaluza-Klein (KK) neutral gauge bosons present in Split-UED. We demonstrate that in this particular case large cross section modifications in the resonance region are necessarily absent and explain why this is so based on the group theoretical structure of the SM. |
1306.6464 | Kentarou Mawatari | P. Artoisenet, P. de Aquino, F. Demartin, R. Frederix, S. Frixione, F.
Maltoni, M. K. Mandal, P. Mathews, K. Mawatari, V. Ravindran, S. Seth, P.
Torrielli, M. Zaro | A framework for Higgs characterisation | 36 pages, 13 figures, 3 tables; v2: some issues clarified and
references added, version to appear in JHEP; v3: sign error of g_AVV in table
2 corrected | null | 10.1007/JHEP11(2013)043 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We introduce a framework, based on an effective field theory approach, that
allows one to perform characterisation studies of the boson recently discovered
at the LHC, for all the relevant channels and in a consistent, systematic and
accurate way. The production and decay of such a boson with various spin and
parity assignments can be simulated by means of multi-parton, tree-level matrix
elements and of next-to-leading order QCD calculations, both matched with
parton showers. Several sample applications are presented which show, in
particular, that beyond-leading-order effects in QCD have non-trivial
phenomenological implications.
| [
{
"created": "Thu, 27 Jun 2013 11:03:11 GMT",
"version": "v1"
},
{
"created": "Fri, 8 Nov 2013 00:08:46 GMT",
"version": "v2"
},
{
"created": "Fri, 31 Jan 2014 19:52:01 GMT",
"version": "v3"
}
] | 2015-06-16 | [
[
"Artoisenet",
"P.",
""
],
[
"de Aquino",
"P.",
""
],
[
"Demartin",
"F.",
""
],
[
"Frederix",
"R.",
""
],
[
"Frixione",
"S.",
""
],
[
"Maltoni",
"F.",
""
],
[
"Mandal",
"M. K.",
""
],
[
"Mathews",
... | We introduce a framework, based on an effective field theory approach, that allows one to perform characterisation studies of the boson recently discovered at the LHC, for all the relevant channels and in a consistent, systematic and accurate way. The production and decay of such a boson with various spin and parity assignments can be simulated by means of multi-parton, tree-level matrix elements and of next-to-leading order QCD calculations, both matched with parton showers. Several sample applications are presented which show, in particular, that beyond-leading-order effects in QCD have non-trivial phenomenological implications. |
1309.6571 | Yukinari Sumino | Y. Kiyo and Y. Sumino | Perturbative heavy quarkonium spectrum at
next-to-next-to-next-to-leading order | Short review on non-perturbative contributions included at the end;
version to appear in Phys.Lett.; 7 pages, 2 figures | null | 10.1016/j.physletb.2014.01.030 | TU-947 | hep-ph hep-lat | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We compute the energy levels of some of the lower-lying heavy quarkonium
states perturbatively up to O(alpha_s^5*m) and O(alpha_s^5*m*log[alpha_s]).
Stability of the predictions depends crucially on the unknown 4-loop pole-MSbar
mass relation. We discuss the current status of the predictions with respect to
the observed bottomonium spectrum.
| [
{
"created": "Wed, 25 Sep 2013 16:57:05 GMT",
"version": "v1"
},
{
"created": "Thu, 23 Jan 2014 08:43:10 GMT",
"version": "v2"
}
] | 2015-06-17 | [
[
"Kiyo",
"Y.",
""
],
[
"Sumino",
"Y.",
""
]
] | We compute the energy levels of some of the lower-lying heavy quarkonium states perturbatively up to O(alpha_s^5*m) and O(alpha_s^5*m*log[alpha_s]). Stability of the predictions depends crucially on the unknown 4-loop pole-MSbar mass relation. We discuss the current status of the predictions with respect to the observed bottomonium spectrum. |
1201.6336 | Franz Gross | Franz Gross, G. Ramalho and M. T. Pena | Covariant nucleon wave function with S, D, and P-state components | 13 pages and 1 figure | Rev. D 85, 093005 (2012) [13 pages] | 10.1103/PhysRevD.85.093005 | JLAB-THY-12-1481 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Expressions for the nucleon wave functions in the covariant spectator theory
(CST) are derived. The nucleon is described as a system with a off-mass-shell
constituent quark, free to interact with an external probe, and two spectator
constituent quarks on their mass shell. Integrating over the internal momentum
of the on-mass-shell quark pair allows us to derive an effective nucleon wave
function that can be written only in terms of the quark and diquark
(quark-pair) variables. The derived nucleon wave function includes
contributions from S, P and D-waves.
| [
{
"created": "Mon, 30 Jan 2012 20:15:41 GMT",
"version": "v1"
}
] | 2012-05-24 | [
[
"Gross",
"Franz",
""
],
[
"Ramalho",
"G.",
""
],
[
"Pena",
"M. T.",
""
]
] | Expressions for the nucleon wave functions in the covariant spectator theory (CST) are derived. The nucleon is described as a system with a off-mass-shell constituent quark, free to interact with an external probe, and two spectator constituent quarks on their mass shell. Integrating over the internal momentum of the on-mass-shell quark pair allows us to derive an effective nucleon wave function that can be written only in terms of the quark and diquark (quark-pair) variables. The derived nucleon wave function includes contributions from S, P and D-waves. |
1205.5005 | Junya Nakamura | Kaoru Hagiwara, Junya Nakamura | Diquark contributions to Top quark charge asymmetry at the Tevatron and
LHC | 18 pages,7 figures, 1 table. Accepted version for publication in JHEP | null | 10.1007/JHEP02(2013)100 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study contributions of a scalar diquark particle in a color representation
of anti-triplet and sextet to the top quark pair production at the Tevatron and
the Large hadron collider (LHC). The model can give Forward-Backward (FB)
asymmetry at the Tevatron while can avoid the same sign top quark production at
the LHC by assuming the top-number conserving diquark couplings. We study
compatibility between the large positive FB asymmetry observed at the Tevatron
and non-observation of the charge asymmetry at the LHC, by including
contributions from the single and pair production of diquarks. We find that the
whole parameter space of the models can soon be explored at the LHC by
measuring the total t-tbar production cross section and the inclusive charge
asymmetry with smaller uncertainties. In addition, we compare the statistical
significance of the charge asymmetry measured at the LHC with that of the
optimal observable of the subprocess FB asymmetry, and find that they are
comparable even when we ignore the uncertainty in the parton distribution
functions.
| [
{
"created": "Tue, 22 May 2012 18:56:28 GMT",
"version": "v1"
},
{
"created": "Sun, 27 Jan 2013 09:30:00 GMT",
"version": "v2"
}
] | 2015-06-05 | [
[
"Hagiwara",
"Kaoru",
""
],
[
"Nakamura",
"Junya",
""
]
] | We study contributions of a scalar diquark particle in a color representation of anti-triplet and sextet to the top quark pair production at the Tevatron and the Large hadron collider (LHC). The model can give Forward-Backward (FB) asymmetry at the Tevatron while can avoid the same sign top quark production at the LHC by assuming the top-number conserving diquark couplings. We study compatibility between the large positive FB asymmetry observed at the Tevatron and non-observation of the charge asymmetry at the LHC, by including contributions from the single and pair production of diquarks. We find that the whole parameter space of the models can soon be explored at the LHC by measuring the total t-tbar production cross section and the inclusive charge asymmetry with smaller uncertainties. In addition, we compare the statistical significance of the charge asymmetry measured at the LHC with that of the optimal observable of the subprocess FB asymmetry, and find that they are comparable even when we ignore the uncertainty in the parton distribution functions. |
2109.01284 | Yun Guo | Lihua Dong, Yun Guo, Ajaharul Islam, and Michael Strickland | Effective Debye Screening Mass in an Anisotropic Quark Gluon Plasma | final version, published in PRD | null | 10.1103/PhysRevD.104.096017 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Due to the rapid longitudinal expansion of the quark-gluon plasma created in
heavy-ion collisions, large local-rest-frame momentum-space anisotropies are
generated during the system's evolution. These momentum-space anisotropies
complicate the modeling of heavy-quarkonium dynamics in the quark-gluon plasma
due to the fact that the resulting inter-quark potentials are spatially
anisotropic, requiring real-time solution of the 3D Schr\"odinger equation.
Herein, we introduce a method for reducing anisotropic heavy-quark potentials
to isotropic ones by introducing an effective screening mass that depends on
the quantum numbers $l$ and $m$ of a given state. We demonstrate that, using
the resulting effective Debye screening masses, one can solve a 1D
Schr\"odinger equation and reproduce the full 3D results for the energies and
binding energies of low-lying heavy-quarkonium bound states to relatively high
accuracy. The resulting effective isotropic potential models could provide an
efficient method for including momentum-anisotropy effects in open quantum
system simulations of heavy-quarkonium dynamics in the quark-gluon plasma.
| [
{
"created": "Fri, 3 Sep 2021 02:48:25 GMT",
"version": "v1"
},
{
"created": "Sun, 26 Dec 2021 04:05:04 GMT",
"version": "v2"
}
] | 2021-12-28 | [
[
"Dong",
"Lihua",
""
],
[
"Guo",
"Yun",
""
],
[
"Islam",
"Ajaharul",
""
],
[
"Strickland",
"Michael",
""
]
] | Due to the rapid longitudinal expansion of the quark-gluon plasma created in heavy-ion collisions, large local-rest-frame momentum-space anisotropies are generated during the system's evolution. These momentum-space anisotropies complicate the modeling of heavy-quarkonium dynamics in the quark-gluon plasma due to the fact that the resulting inter-quark potentials are spatially anisotropic, requiring real-time solution of the 3D Schr\"odinger equation. Herein, we introduce a method for reducing anisotropic heavy-quark potentials to isotropic ones by introducing an effective screening mass that depends on the quantum numbers $l$ and $m$ of a given state. We demonstrate that, using the resulting effective Debye screening masses, one can solve a 1D Schr\"odinger equation and reproduce the full 3D results for the energies and binding energies of low-lying heavy-quarkonium bound states to relatively high accuracy. The resulting effective isotropic potential models could provide an efficient method for including momentum-anisotropy effects in open quantum system simulations of heavy-quarkonium dynamics in the quark-gluon plasma. |
1607.02082 | Andre Veiga Giannini | F.O. Dur\~aes, A.V. Giannini, V.P. Goncalves and F.S. Navarra | Testing the running coupling $k_{T}$-factorization formula for the
inclusive gluon production | 9 pages and 4 figures | Phys. Rev. D 94, 054023 (2016) | 10.1103/PhysRevD.94.054023 | null | hep-ph hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The inclusive gluon production at midrapidities is described in the Color
Glass Condensate formalism using the $k_T$ - factorization formula, which was
derived at fixed coupling constant considering the scattering of a dilute
system of partons with a dense one. Recent analysis demonstrated that this
approach provides a satisfactory description of the experimental data for the
inclusive hadron production in $pp/pA/AA$ collisions. However, these studies
are based on the fixed coupling $k_T$ - factorization formula, which does not
take into account the running coupling corrections, which are important to set
the scales present in the cross section. In this paper we consider the running
coupling corrected $k_T$ - factorization formula conjectured some years ago and
investigate the impact of the running coupling corrections on the observables.
In particular, the pseudorapidity distributions and charged hadrons
multiplicity are calculated considering $pp$, $dAu/pPb$ and $AuAu/PbPb$
collisions at RHIC and LHC energies. We compare the corrected running coupling
predictions with those obtained using the original $k_T$ - factorization
assuming a fixed coupling or a prescription for the inclusion of the running of
the coupling. Considering the Kharzeev - Levin - Nardi unintegrated gluon
distribution and a simplified model for the nuclear geometry, we demonstrate
that the distinct predictions are similar for the pseudorapidity distributions
in $pp/pA/AA$ collisions and for the charged hadrons multiplicity in $pp/pA$
collisions. On the other hand, the running coupling corrected $k_T$ -
factorization formula predicts a smoother energy dependence for $dN/d\eta$ in
$AA$ collisions.
| [
{
"created": "Thu, 7 Jul 2016 16:59:33 GMT",
"version": "v1"
}
] | 2016-09-28 | [
[
"Durães",
"F. O.",
""
],
[
"Giannini",
"A. V.",
""
],
[
"Goncalves",
"V. P.",
""
],
[
"Navarra",
"F. S.",
""
]
] | The inclusive gluon production at midrapidities is described in the Color Glass Condensate formalism using the $k_T$ - factorization formula, which was derived at fixed coupling constant considering the scattering of a dilute system of partons with a dense one. Recent analysis demonstrated that this approach provides a satisfactory description of the experimental data for the inclusive hadron production in $pp/pA/AA$ collisions. However, these studies are based on the fixed coupling $k_T$ - factorization formula, which does not take into account the running coupling corrections, which are important to set the scales present in the cross section. In this paper we consider the running coupling corrected $k_T$ - factorization formula conjectured some years ago and investigate the impact of the running coupling corrections on the observables. In particular, the pseudorapidity distributions and charged hadrons multiplicity are calculated considering $pp$, $dAu/pPb$ and $AuAu/PbPb$ collisions at RHIC and LHC energies. We compare the corrected running coupling predictions with those obtained using the original $k_T$ - factorization assuming a fixed coupling or a prescription for the inclusion of the running of the coupling. Considering the Kharzeev - Levin - Nardi unintegrated gluon distribution and a simplified model for the nuclear geometry, we demonstrate that the distinct predictions are similar for the pseudorapidity distributions in $pp/pA/AA$ collisions and for the charged hadrons multiplicity in $pp/pA$ collisions. On the other hand, the running coupling corrected $k_T$ - factorization formula predicts a smoother energy dependence for $dN/d\eta$ in $AA$ collisions. |
hep-ph/0005248 | David London | David London, Nita Sinha and Rahul Sinha | Extracting Weak Phase Information from B -> V_1 V_2 Decays | 4 pages, RevTeX, no figures | Phys.Rev.Lett. 85 (2000) 1807-1810 | 10.1103/PhysRevLett.85.1807 | UdeM-GPP-TH-00-72, IMSc-00/05/17 | hep-ph | null | We describe a new method for extracting weak, CP-violating phase information,
with no hadronic uncertainties, from an angular analysis of B -> V_1 V_2
decays, where V_1 and V_2 are vector mesons. The quantity $\sin^2 (2\beta +
\gamma)$ can be cleanly obtained from the study of decays such as B_d^0(t) ->
D^{*\pm} \rho^\mp, D^{*\pm} a_1^{\mp}, D^{*0} K^{*0}, etc. Similarly, one can
use B_s^0(t) -> D_s^{*\pm} K^{*\mp} to extract $\sin^2 \gamma$. There are no
penguin contributions to these decays. It is possible that $\sin^2 (2\beta +
\gamma)$ will be the second function of CP phases, after $\sin 2\beta$, to be
measured at B-factories.
| [
{
"created": "Wed, 24 May 2000 20:33:51 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"London",
"David",
""
],
[
"Sinha",
"Nita",
""
],
[
"Sinha",
"Rahul",
""
]
] | We describe a new method for extracting weak, CP-violating phase information, with no hadronic uncertainties, from an angular analysis of B -> V_1 V_2 decays, where V_1 and V_2 are vector mesons. The quantity $\sin^2 (2\beta + \gamma)$ can be cleanly obtained from the study of decays such as B_d^0(t) -> D^{*\pm} \rho^\mp, D^{*\pm} a_1^{\mp}, D^{*0} K^{*0}, etc. Similarly, one can use B_s^0(t) -> D_s^{*\pm} K^{*\mp} to extract $\sin^2 \gamma$. There are no penguin contributions to these decays. It is possible that $\sin^2 (2\beta + \gamma)$ will be the second function of CP phases, after $\sin 2\beta$, to be measured at B-factories. |
hep-ph/0311343 | Gergely G\'abor Barnaf\"oldi | G.G. Barnafoldi, P. Levai, G. Papp, G. Fai and M. Gyulassy | Jet Tomography Studies in AuAu Collision at RHIC Energies | Talk given at European Physical Society International Europhysics
Conference on High Energy Physics HEP2003, July 17-23. 2003, in Aachen,
Germany 3 pages in LaTeX, 2 EPS figure. (Accepted for publication in European
Physical Journal C direct) | Eur.Phys.J.C33:s609-s611,2004 | 10.1140/epjcd/s2004-03-1838-x | null | hep-ph | null | Recent RHIC results on pion production in AuAu collision at sqrt(s)=130 and
200 AGeV display a strong suppression effect at high p_T. This suppression can
be connected to final state effects, namely jet energy loss induced by the
produced dense colored matter. Applying our pQCD-based parton model we perform
a quantitative analysis of the measured suppression pattern and determine the
opacity of the produced deconfined matter.
| [
{
"created": "Wed, 26 Nov 2003 16:35:08 GMT",
"version": "v1"
}
] | 2009-10-09 | [
[
"Barnafoldi",
"G. G.",
""
],
[
"Levai",
"P.",
""
],
[
"Papp",
"G.",
""
],
[
"Fai",
"G.",
""
],
[
"Gyulassy",
"M.",
""
]
] | Recent RHIC results on pion production in AuAu collision at sqrt(s)=130 and 200 AGeV display a strong suppression effect at high p_T. This suppression can be connected to final state effects, namely jet energy loss induced by the produced dense colored matter. Applying our pQCD-based parton model we perform a quantitative analysis of the measured suppression pattern and determine the opacity of the produced deconfined matter. |
1608.04940 | Maxim Dvornikov | Maxim Dvornikov (IZMIRAN, Tomsk State University, University of
Hamburg) | Role of particle masses in the magnetic field generation driven by the
parity violating interaction | 5 pages in pdflatex, Elsevier latex style | Phys. Lett. B 760, 406-410 (2016) | 10.1016/j.physletb.2016.07.020 | null | hep-ph astro-ph.HE hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Recently the new model for the generation of strong large scale magnetic
fields in neutron stars, driven by the parity violating interaction, was
proposed. In this model, the magnetic field instability results from the
modification of the chiral magnetic effect in presence of the electroweak
interaction between ultrarelativistic electrons and nucleons. In the present
work we study how a nonzero mass of charged particles, which are degenerate
relativistic electrons and nonrelativistic protons, influences the generation
of the magnetic field in frames of this approach. For this purpose we calculate
the induced electric current of these charged particles, electroweakly
interacting with background neutrons and an external magnetic field, exactly
accounting for the particle mass. This current is calculated by two methods:
using the exact solution of the Dirac equation for a charged particle in
external fields and computing the polarization operator of a photon in matter
composed of background neutrons. We show that the induced current is vanishing
in both approaches leading to the zero contribution of massive particles to the
generated magnetic field. We discuss the implication of our results for the
problem of the magnetic field generation in compact stars.
| [
{
"created": "Wed, 17 Aug 2016 12:26:05 GMT",
"version": "v1"
}
] | 2016-08-18 | [
[
"Dvornikov",
"Maxim",
"",
"IZMIRAN, Tomsk State University, University of\n Hamburg"
]
] | Recently the new model for the generation of strong large scale magnetic fields in neutron stars, driven by the parity violating interaction, was proposed. In this model, the magnetic field instability results from the modification of the chiral magnetic effect in presence of the electroweak interaction between ultrarelativistic electrons and nucleons. In the present work we study how a nonzero mass of charged particles, which are degenerate relativistic electrons and nonrelativistic protons, influences the generation of the magnetic field in frames of this approach. For this purpose we calculate the induced electric current of these charged particles, electroweakly interacting with background neutrons and an external magnetic field, exactly accounting for the particle mass. This current is calculated by two methods: using the exact solution of the Dirac equation for a charged particle in external fields and computing the polarization operator of a photon in matter composed of background neutrons. We show that the induced current is vanishing in both approaches leading to the zero contribution of massive particles to the generated magnetic field. We discuss the implication of our results for the problem of the magnetic field generation in compact stars. |
1412.0708 | David Latimer | Audrey K. Kvam and David C. Latimer | Astrophysical constraints on millicharged atomic dark matter | null | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Some models of inelastic dark matter posit the existence of bound states
under some new $U(1)'$ gauge symmetry. If this new dark photon kinetically
mixes with the standard model photon, then the constituent particles in these
bound states can acquire a fractional electric charge. This electric charge
renders a dark-matter medium dispersive. We compute this frequency-dependent
index of refraction for such a medium and use the frequency-dependent arrival
time of light from astrophysical sources to constrain the properties of dark
atoms in the medium. Using optical-wavelength observations from the Crab
Pulsar, we find the electric millicharge of dark (electrons) protons to be
smaller than the electric charge $e$ for dark atom masses below 100 keV,
assuming a dark fine structure constant $\boldsymbol{\alpha}=1$. We estimate
that future broadband observations of gamma-ray bursts can produce constraints
on the millicharge of dark atoms with masses in the keV range that are
competitive with existing collider constraints.
| [
{
"created": "Mon, 1 Dec 2014 22:24:01 GMT",
"version": "v1"
}
] | 2014-12-03 | [
[
"Kvam",
"Audrey K.",
""
],
[
"Latimer",
"David C.",
""
]
] | Some models of inelastic dark matter posit the existence of bound states under some new $U(1)'$ gauge symmetry. If this new dark photon kinetically mixes with the standard model photon, then the constituent particles in these bound states can acquire a fractional electric charge. This electric charge renders a dark-matter medium dispersive. We compute this frequency-dependent index of refraction for such a medium and use the frequency-dependent arrival time of light from astrophysical sources to constrain the properties of dark atoms in the medium. Using optical-wavelength observations from the Crab Pulsar, we find the electric millicharge of dark (electrons) protons to be smaller than the electric charge $e$ for dark atom masses below 100 keV, assuming a dark fine structure constant $\boldsymbol{\alpha}=1$. We estimate that future broadband observations of gamma-ray bursts can produce constraints on the millicharge of dark atoms with masses in the keV range that are competitive with existing collider constraints. |
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