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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
hep-ph/0205028 | Takashi Inoue | T. Inoue and E. Oset | eta in the nuclear medium within a chiral unitary approach | LaTeX, 13 pages, 9 figures | Nucl.Phys. A710 (2002) 354-370 | 10.1016/S0375-9474(02)01167-3 | null | hep-ph nucl-th | null | The self-energy of an eta meson in the nuclear medium is calculated in a
chiral unitary approach.
A coupled channel Bethe-Salpeter equation is solved to obtain the effective
eta-N interaction in the medium.
The base model reproduces well the free space pi-N elastic and inelastic
scattering at the eta-N threshold or N^*(1535) region.
The Pauli blocking on the nucleons, binding potentials for the baryons and
self-energies of the mesons are incorporated, including the eta self-energy in
a self-consistent way.
Our calculation predicts about -54 -i29 MeV for the optical potential at
normal nuclear matter for an eta at threshold but also shows a strong energy
dependence of the potential.
| [
{
"created": "Thu, 2 May 2002 18:55:07 GMT",
"version": "v1"
}
] | 2016-09-06 | [
[
"Inoue",
"T.",
""
],
[
"Oset",
"E.",
""
]
] | The self-energy of an eta meson in the nuclear medium is calculated in a chiral unitary approach. A coupled channel Bethe-Salpeter equation is solved to obtain the effective eta-N interaction in the medium. The base model reproduces well the free space pi-N elastic and inelastic scattering at the eta-N threshold or N^*(1535) region. The Pauli blocking on the nucleons, binding potentials for the baryons and self-energies of the mesons are incorporated, including the eta self-energy in a self-consistent way. Our calculation predicts about -54 -i29 MeV for the optical potential at normal nuclear matter for an eta at threshold but also shows a strong energy dependence of the potential. |
1501.07766 | Xiang Liu | Kan Chen, Cheng-Qun Pang, Xiang Liu and Takayuki Matsuki | Light axial vector mesons | 18 pages, 11 tables and 25 figures. More discussion added and typos
corrected. Accepted by Phys. Rev. D | Phys. Rev. D 91, 074025 (2015) | 10.1103/PhysRevD.91.074025 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Inspired by the abundant experimental observation of axial-vector states, we
study whether the observed axial-vector states can be categorized into the
conventional axial-vector meson family. In this paper we carry out an analysis
based on the mass spectra and two-body Okubo-Zweig-Iizuka-allowed decays.
Besides testing the possible axial-vector meson assignments, we also predict
abundant information for their decays and the properties of some missing
axial-vector mesons, which are valuable for further experimental exploration of
the observed and predicted axial-vector mesons.
| [
{
"created": "Fri, 30 Jan 2015 13:32:33 GMT",
"version": "v1"
},
{
"created": "Tue, 7 Apr 2015 02:16:42 GMT",
"version": "v2"
},
{
"created": "Sat, 18 Apr 2015 03:18:14 GMT",
"version": "v3"
}
] | 2015-04-23 | [
[
"Chen",
"Kan",
""
],
[
"Pang",
"Cheng-Qun",
""
],
[
"Liu",
"Xiang",
""
],
[
"Matsuki",
"Takayuki",
""
]
] | Inspired by the abundant experimental observation of axial-vector states, we study whether the observed axial-vector states can be categorized into the conventional axial-vector meson family. In this paper we carry out an analysis based on the mass spectra and two-body Okubo-Zweig-Iizuka-allowed decays. Besides testing the possible axial-vector meson assignments, we also predict abundant information for their decays and the properties of some missing axial-vector mesons, which are valuable for further experimental exploration of the observed and predicted axial-vector mesons. |
1111.3027 | Ajit Mohan Srivastava | Abhishek Atreya, Anjishnu Sarkar, Ajit M. Srivastava | Spontaneous CP violation in quark scattering from QCD Z(3) interfaces | 13 pages, Latex, 7 figures, Two different effective potentials
studied with similar temperatures showing consistent results. Final published
version | Physical Review D 85, 014009 (2012) | 10.1103/PhysRevD.85.014009 | null | hep-ph astro-ph.CO nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper, we explore the possibility of spontaneous CP violation in the
scattering of quarks and anti-quarks from QCD Z(3) domain walls. The CP
violation here arises from the nontrivial profile of the background gauge field
$(A_{0})$ between different Z(3) vacua. We calculate the spatial variation of
$A_{0}$ across the Z(3) interface from the profile of the Polyakov loop
$L(\vec{x})$ for the Z(3) interface and calculate the reflection of quarks and
antiquarks using the Dirac equation. This spontaneous CP violation has
interesting consequences for the relativistic heavy-ion collision experiments,
such as baryon enhancement at high $P_{T}$. It also acts as a source of
additional J/$\psi$ suppression. We also discuss its implications for the early
universe.
| [
{
"created": "Sun, 13 Nov 2011 16:09:03 GMT",
"version": "v1"
},
{
"created": "Mon, 30 Jan 2012 17:02:54 GMT",
"version": "v2"
}
] | 2012-01-31 | [
[
"Atreya",
"Abhishek",
""
],
[
"Sarkar",
"Anjishnu",
""
],
[
"Srivastava",
"Ajit M.",
""
]
] | In this paper, we explore the possibility of spontaneous CP violation in the scattering of quarks and anti-quarks from QCD Z(3) domain walls. The CP violation here arises from the nontrivial profile of the background gauge field $(A_{0})$ between different Z(3) vacua. We calculate the spatial variation of $A_{0}$ across the Z(3) interface from the profile of the Polyakov loop $L(\vec{x})$ for the Z(3) interface and calculate the reflection of quarks and antiquarks using the Dirac equation. This spontaneous CP violation has interesting consequences for the relativistic heavy-ion collision experiments, such as baryon enhancement at high $P_{T}$. It also acts as a source of additional J/$\psi$ suppression. We also discuss its implications for the early universe. |
1911.03840 | Yizhuang Liu | Xiangdong Ji, Yizhuang Liu, and Yu-Sheng Liu | Transverse-Momentum-Dependent Parton Distribution Functions from
Large-Momentum Effective Theory | 8 pages, 4 figures | null | 10.1016/j.physletb.2020.135946 | null | hep-ph hep-ex hep-lat nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We show that transverse-momentum-dependent parton distribution functions
(TMDPDFs), important non-perturbative quantities for describing the properties
of hadrons in high-energy scattering processes such as Drell-Yan and
semi-inclusive deep-inelastic scattering with observed small transverse
momentum, can be obtained from Euclidean QCD calculations in the framework of
large-momentum effective theory (LaMET). We present a LaMET factorization of
the Euclidean quasi-TMDPDFs in terms of the physical TMDPDFs and off-light-cone
soft function at leading order in $1/P^z$ expansion, with the perturbative
matching coefficient satisfying a renormalization group equation. We also
discuss the implementation in lattice QCD with finite-length gauge links as
well as the rapidity-regularization-independent factorization for Drell-Yan
cross section.
| [
{
"created": "Sun, 10 Nov 2019 03:01:33 GMT",
"version": "v1"
},
{
"created": "Mon, 9 Nov 2020 17:22:31 GMT",
"version": "v2"
}
] | 2020-12-30 | [
[
"Ji",
"Xiangdong",
""
],
[
"Liu",
"Yizhuang",
""
],
[
"Liu",
"Yu-Sheng",
""
]
] | We show that transverse-momentum-dependent parton distribution functions (TMDPDFs), important non-perturbative quantities for describing the properties of hadrons in high-energy scattering processes such as Drell-Yan and semi-inclusive deep-inelastic scattering with observed small transverse momentum, can be obtained from Euclidean QCD calculations in the framework of large-momentum effective theory (LaMET). We present a LaMET factorization of the Euclidean quasi-TMDPDFs in terms of the physical TMDPDFs and off-light-cone soft function at leading order in $1/P^z$ expansion, with the perturbative matching coefficient satisfying a renormalization group equation. We also discuss the implementation in lattice QCD with finite-length gauge links as well as the rapidity-regularization-independent factorization for Drell-Yan cross section. |
1305.1797 | Thomas Lang | Thomas Lang, Hendrik van Hees, Jan Steinheimer, Marcus Bleicher | Elliptic flow and nuclear modification factors of D-mesons at FAIR in a
Hybrid-Langevin approach | 10 pages, 8 figures | null | null | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The Compressed Baryonic Matter (CBM) experiment at the Facility for
Anti-proton and Ion Research (FAIR) will provide new possibilities for
charm-quark ($D$-meson) observables in heavy-ion collisions at low collision
energies and high baryon densities. To predict the collective flow and nuclear
modification factors of charm quarks in this environment, we apply a Langevin
approach for the transport of charm quarks in the UrQMD (hydrodynamics +
Boltzmann) hybrid model. Due to the inclusion of event-by-event fluctuations
and a full (3+1) dimensional hydrodynamical evolution, the UrQMD hybrid
approach provides a realistic evolution of the matter produced in heavy-ion
collisions.
As drag and diffusion coefficients we use a resonance approach for elastic
heavy-quark scattering and assume a decoupling temperature of the charm quarks
from the hot medium of $130\, \MeV$. Hadronization of the charm quarks to
$D$-mesons by coalescence is included. Since the initial charm-quark
distribution at FAIR is unknown, we utilize two different initial charm-quark
distributions in our approach to estimate the uncertainty of these predictions.
We present calculations of the nuclear modification factor, $R_{AA}$, as well
as for the elliptic flow, $v_2$, in Pb+Pb collisions at
$E_{lab}=25\,\text{AGeV}$. The different medium modifications of $D$-mesons and
$\bar{D}$-mesons at high baryon-chemical potential are explored by modified
drag- and diffusion-coefficients using the corresponding fugacity factor. Here
we find a considerably larger medium modification for $\bar{\mathrm{D}}$- than
for $D$-mesons.
| [
{
"created": "Wed, 8 May 2013 12:46:09 GMT",
"version": "v1"
}
] | 2013-05-09 | [
[
"Lang",
"Thomas",
""
],
[
"van Hees",
"Hendrik",
""
],
[
"Steinheimer",
"Jan",
""
],
[
"Bleicher",
"Marcus",
""
]
] | The Compressed Baryonic Matter (CBM) experiment at the Facility for Anti-proton and Ion Research (FAIR) will provide new possibilities for charm-quark ($D$-meson) observables in heavy-ion collisions at low collision energies and high baryon densities. To predict the collective flow and nuclear modification factors of charm quarks in this environment, we apply a Langevin approach for the transport of charm quarks in the UrQMD (hydrodynamics + Boltzmann) hybrid model. Due to the inclusion of event-by-event fluctuations and a full (3+1) dimensional hydrodynamical evolution, the UrQMD hybrid approach provides a realistic evolution of the matter produced in heavy-ion collisions. As drag and diffusion coefficients we use a resonance approach for elastic heavy-quark scattering and assume a decoupling temperature of the charm quarks from the hot medium of $130\, \MeV$. Hadronization of the charm quarks to $D$-mesons by coalescence is included. Since the initial charm-quark distribution at FAIR is unknown, we utilize two different initial charm-quark distributions in our approach to estimate the uncertainty of these predictions. We present calculations of the nuclear modification factor, $R_{AA}$, as well as for the elliptic flow, $v_2$, in Pb+Pb collisions at $E_{lab}=25\,\text{AGeV}$. The different medium modifications of $D$-mesons and $\bar{D}$-mesons at high baryon-chemical potential are explored by modified drag- and diffusion-coefficients using the corresponding fugacity factor. Here we find a considerably larger medium modification for $\bar{\mathrm{D}}$- than for $D$-mesons. |
hep-ph/0403063 | Grzegorz Wilk | M.Biyajima, M.Kaneyama, T.Mizoguchi and G.Wilk | Analyses of k_t distributions at RHIC by means of some selected
statistical and stochastic models | Modified version. One new figure, one new table and one reference
addeed | Eur.Phys.J. C40 (2005) 243-250 | 10.1140/epjc/s2005-02140-2 | null | hep-ph cond-mat.stat-mech nucl-th | null | The new data on k_t distributions obtained at RHIC are analysed by means of
selected models of statistical and stochastic origin in order to estimate their
importance in providing new information on hadronization process, in particular
on the value of the temperature at freeze-out to hadronic phase.
| [
{
"created": "Fri, 5 Mar 2004 12:12:23 GMT",
"version": "v1"
},
{
"created": "Thu, 11 Mar 2004 09:34:52 GMT",
"version": "v2"
},
{
"created": "Sat, 15 May 2004 14:20:58 GMT",
"version": "v3"
},
{
"created": "Thu, 16 Dec 2004 11:44:38 GMT",
"version": "v4"
}
] | 2009-11-10 | [
[
"Biyajima",
"M.",
""
],
[
"Kaneyama",
"M.",
""
],
[
"Mizoguchi",
"T.",
""
],
[
"Wilk",
"G.",
""
]
] | The new data on k_t distributions obtained at RHIC are analysed by means of selected models of statistical and stochastic origin in order to estimate their importance in providing new information on hadronization process, in particular on the value of the temperature at freeze-out to hadronic phase. |
2203.10986 | Magno Machado | G.S. Ramos, M.V.T. Machado | Investigating the QCD dynamical entropy in high-energy hadronic
collisions | 08 pages, 4 figures | null | 10.1103/PhysRevD.105.094009 | null | hep-ph hep-ex hep-th | http://creativecommons.org/licenses/by/4.0/ | The dynamical entropy of dense gluonic states in proton-proton collisions at
high energies is studied by using phenomenological models for the unintegrated
gluon distribution. The corresponding transverse momentum probability
distributions are evaluated in terms of rapidity. The dynamical entropy density
is obtained in the rapidity range relevant for the collisions at the Large
Hadron Collider. The total entropy density for the dense system is computed as
a function of the rapidity evolution $\Delta Y = Y-Y_0$ given an initial
rapidity $Y_0$. The theoretical uncertainties are investigated and comparison
with related approaches in literature is done.
| [
{
"created": "Mon, 21 Mar 2022 13:48:12 GMT",
"version": "v1"
}
] | 2022-05-25 | [
[
"Ramos",
"G. S.",
""
],
[
"Machado",
"M. V. T.",
""
]
] | The dynamical entropy of dense gluonic states in proton-proton collisions at high energies is studied by using phenomenological models for the unintegrated gluon distribution. The corresponding transverse momentum probability distributions are evaluated in terms of rapidity. The dynamical entropy density is obtained in the rapidity range relevant for the collisions at the Large Hadron Collider. The total entropy density for the dense system is computed as a function of the rapidity evolution $\Delta Y = Y-Y_0$ given an initial rapidity $Y_0$. The theoretical uncertainties are investigated and comparison with related approaches in literature is done. |
2305.14273 | Hyun Jeong | Hyun Jeong, Kohei Kamada, Alexei A. Starobinsky, Jun'ichi Yokoyama | Reheating process in the $R^2$ inflationary model with the baryogenesis
scenario | Presentation expanded, the case of hierarchical Yukawa matrix is
considered, and previous conclusions unchanged (29 pages, 12 figures) | null | null | RESCEU-13/23 | hep-ph astro-ph.CO | http://creativecommons.org/licenses/by/4.0/ | Post-inflationary evolution and (re)heating of the viable inflationary model,
the $R^2$ one, is made more realistic by including the leptogenesis scenario
into it. For this purpose, right-handed Majorana neutrinos with a large mass
are added to the matter sector of the Standard Model to explain the neutrino
oscillation experiments and the baryon asymmetry of the Universe. We have found
parameters that characterize this model: non-minimal coupling of the Higgs
field $\xi$, the mass of the right-handed Majorana neutrino $M_{N_\alpha}$ and
the Yukawa coupling matrix components for the right-handed Majorana neutrino.
We have analyzed the effect of these parameters on the reheating process and
leptogenesis in this model and how they affect the resultant physical
quantities: spectral parameters of primordial perturbations and baryon
asymmetry.
| [
{
"created": "Tue, 23 May 2023 17:23:42 GMT",
"version": "v1"
},
{
"created": "Fri, 25 Aug 2023 16:00:32 GMT",
"version": "v2"
}
] | 2023-08-28 | [
[
"Jeong",
"Hyun",
""
],
[
"Kamada",
"Kohei",
""
],
[
"Starobinsky",
"Alexei A.",
""
],
[
"Yokoyama",
"Jun'ichi",
""
]
] | Post-inflationary evolution and (re)heating of the viable inflationary model, the $R^2$ one, is made more realistic by including the leptogenesis scenario into it. For this purpose, right-handed Majorana neutrinos with a large mass are added to the matter sector of the Standard Model to explain the neutrino oscillation experiments and the baryon asymmetry of the Universe. We have found parameters that characterize this model: non-minimal coupling of the Higgs field $\xi$, the mass of the right-handed Majorana neutrino $M_{N_\alpha}$ and the Yukawa coupling matrix components for the right-handed Majorana neutrino. We have analyzed the effect of these parameters on the reheating process and leptogenesis in this model and how they affect the resultant physical quantities: spectral parameters of primordial perturbations and baryon asymmetry. |
0710.2010 | Tania Robens | Tania Robens | NLO Event Simulation for Chargino Production at the ILC | 4 pages, 6 figures; submitted for the SUSY07 proceedings | null | null | PITHA 07/12, SFB/CPP-07-67 | hep-ph | null | We present an extension of the Monte Carlo Event Generator Whizard which
includes chargino production at the ILC at NLO. We include photons using both a
fixed order and a resummation approach. While the fixed order approach suffers
from negative event weights, the resummation method solves this problem and
automatically includes leading higher order corrections. We present results for
cross sections and event generation for both methods and evaluate the
systematic errors due to soft and collinear approximations. In the resummation
approach, the residual uncertainty can be brought down to the per-mil level.
| [
{
"created": "Wed, 10 Oct 2007 13:55:54 GMT",
"version": "v1"
}
] | 2007-10-11 | [
[
"Robens",
"Tania",
""
]
] | We present an extension of the Monte Carlo Event Generator Whizard which includes chargino production at the ILC at NLO. We include photons using both a fixed order and a resummation approach. While the fixed order approach suffers from negative event weights, the resummation method solves this problem and automatically includes leading higher order corrections. We present results for cross sections and event generation for both methods and evaluate the systematic errors due to soft and collinear approximations. In the resummation approach, the residual uncertainty can be brought down to the per-mil level. |
hep-ph/0001175 | S. Y. Choi | S.Y. Choi (KIAS), M. Guchait (DESY), J. Kalinowski (Warsaw U.) and
P.M. Zerwas (DESY) | Chargino Pair Production at $e^+e^-$ Colliders with Polarized Beams | 19 pages including 4 figures | Phys.Lett. B479 (2000) 235-244 | 10.1016/S0370-2693(00)00293-8 | DESY 99-198, KIAS-P99111, IFT-99/34 | hep-ph | null | The chargino $\tilde{\chi}^\pm_{1,2}$ system can be reconstructed completely
in $e^+e^-$ collisions. By measuring the total cross sections and the
asymmetries with polarized beams in $e^+e^-\to\tilde{\chi}_i^+ \tilde{\chi}_j^-
[i,j=1,2]$, the chargino masses and the gaugino-higgsino mixing angles of these
states can be determined very accurately. If only the lightest charginos
$\tilde{\chi}_1^\pm$ are kinematically accessible, transverse beam polarization
is needed to determine the mixing angles unambiguously. From these observables
the fundamental SUSY parameters can be derived: the SU(2) gaugino mass $M_2$,
the modulus and the cosine of the CP-violating phase of the higgsino mass
parameter $\mu$, and $\tan\beta = v_2/v_1$, the ratio of the vacuum expectation
values of the two neutral Higgs doublet fields. [The remaining two-fold
ambiguity of the phase can be resolved by measuring the normal polarization of
the charginos.]
| [
{
"created": "Tue, 18 Jan 2000 08:16:57 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Choi",
"S. Y.",
"",
"KIAS"
],
[
"Guchait",
"M.",
"",
"DESY"
],
[
"Kalinowski",
"J.",
"",
"Warsaw U."
],
[
"Zerwas",
"P. M.",
"",
"DESY"
]
] | The chargino $\tilde{\chi}^\pm_{1,2}$ system can be reconstructed completely in $e^+e^-$ collisions. By measuring the total cross sections and the asymmetries with polarized beams in $e^+e^-\to\tilde{\chi}_i^+ \tilde{\chi}_j^- [i,j=1,2]$, the chargino masses and the gaugino-higgsino mixing angles of these states can be determined very accurately. If only the lightest charginos $\tilde{\chi}_1^\pm$ are kinematically accessible, transverse beam polarization is needed to determine the mixing angles unambiguously. From these observables the fundamental SUSY parameters can be derived: the SU(2) gaugino mass $M_2$, the modulus and the cosine of the CP-violating phase of the higgsino mass parameter $\mu$, and $\tan\beta = v_2/v_1$, the ratio of the vacuum expectation values of the two neutral Higgs doublet fields. [The remaining two-fold ambiguity of the phase can be resolved by measuring the normal polarization of the charginos.] |
2309.15922 | Shuang-Yong Zhou | Qing Chen, Ken Mimasu, Tong Arthur Wu, Guo-Dong Zhang, Shuang-Yong
Zhou | Capping the positivity cone: dimension-8 Higgs operators in the SMEFT | 32 pages + appendices, 9 figures; to appear in JHEP | null | null | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | SMEFT Wilson coefficients are subject to various positivity bounds in order
to be consistent with the fundamental principles of S-matrix. Previous bounds
on dimension-8 SMEFT operators have been obtained using the positivity part of
UV partial wave unitarity and form a (projective) convex cone. We derive a set
of linear UV unitarity conditions that go beyond positivity and are easy to
implement in an optimization scheme with dispersion relations in a multi-field
EFT. Using Higgs scattering as an example, we demonstrate how to obtain closed
bounds in the space of the three relevant dimension-8 coefficients, making use
of the UV unitarity conditions as well as so-called null constraints that arise
from full crossing symmetry. Specifically, we show that they are bounded by
inequalities schematically going like $C<O\left((4\pi)^2\right)$. We compare
the newly obtained upper bounds with the traditional perturbative unitarity
bounds from within the EFT, and discuss some phenomenological implications of
the two-sided positivity bounds in the context of experimental probes of Vector
Boson Scattering.
| [
{
"created": "Wed, 27 Sep 2023 18:01:01 GMT",
"version": "v1"
},
{
"created": "Sat, 9 Mar 2024 07:01:49 GMT",
"version": "v2"
}
] | 2024-03-12 | [
[
"Chen",
"Qing",
""
],
[
"Mimasu",
"Ken",
""
],
[
"Wu",
"Tong Arthur",
""
],
[
"Zhang",
"Guo-Dong",
""
],
[
"Zhou",
"Shuang-Yong",
""
]
] | SMEFT Wilson coefficients are subject to various positivity bounds in order to be consistent with the fundamental principles of S-matrix. Previous bounds on dimension-8 SMEFT operators have been obtained using the positivity part of UV partial wave unitarity and form a (projective) convex cone. We derive a set of linear UV unitarity conditions that go beyond positivity and are easy to implement in an optimization scheme with dispersion relations in a multi-field EFT. Using Higgs scattering as an example, we demonstrate how to obtain closed bounds in the space of the three relevant dimension-8 coefficients, making use of the UV unitarity conditions as well as so-called null constraints that arise from full crossing symmetry. Specifically, we show that they are bounded by inequalities schematically going like $C<O\left((4\pi)^2\right)$. We compare the newly obtained upper bounds with the traditional perturbative unitarity bounds from within the EFT, and discuss some phenomenological implications of the two-sided positivity bounds in the context of experimental probes of Vector Boson Scattering. |
2108.07740 | Shu-Yi Wei | Kai-bao Chen, Zuo-tang Liang, Yu-kun Song, Shu-yi Wei | Longitudinal and transverse polarizations of $\Lambda$ hyperon in
unpolarized SIDIS and $e^+e^-$ annihilation | 13 pages, 7 figures; to be published on PRD | null | 10.1103/PhysRevD.105.034027 | null | hep-ph hep-ex nucl-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We make a systematic study of $\Lambda$ hyperon polarizations in unpolarized
lepton induced semi-inclusive reactions such as $e^-N\to e^-\Lambda X$ and
$e^+e^-\to\Lambda h X$. We present the general form of cross sections in terms
of structure functions obtained from a general kinematic analysis. This already
shows that the produced hyperons can be polarized in three orthogonal
directions, i.e., the longitudinal direction along the hyperon momentum, the
normal direction of the production plane, and the transverse direction in the
production plane. We present the parton model results at the leading twist and
leading order in perturbative QCD and provide the expressions for these
structure functions and polarizations in terms of parton distribution functions
and fragmentation functions. We emphasize in particular that by studying the
longitudinal polarization and the transverse polarization in the production
plane, we can extract the corresponding chiral-odd fragmentation functions
$H_{1Lq}^{\perp\Lambda}$, $H_{1Tq}^{\Lambda}$ and $H_{1Tq}^{\perp\Lambda}$. We
also present numerical results of rough estimates utilizing available
parameterizations of fragmentation functions and approximations. We discuss how
to measure these polarizations and point out in particular that they can be
carried out in future EIC and/or $e^+e^-$ annihilation experiments such as
Belle.
| [
{
"created": "Tue, 17 Aug 2021 16:21:42 GMT",
"version": "v1"
},
{
"created": "Tue, 31 Aug 2021 10:24:36 GMT",
"version": "v2"
},
{
"created": "Sat, 19 Feb 2022 07:20:52 GMT",
"version": "v3"
}
] | 2022-03-14 | [
[
"Chen",
"Kai-bao",
""
],
[
"Liang",
"Zuo-tang",
""
],
[
"Song",
"Yu-kun",
""
],
[
"Wei",
"Shu-yi",
""
]
] | We make a systematic study of $\Lambda$ hyperon polarizations in unpolarized lepton induced semi-inclusive reactions such as $e^-N\to e^-\Lambda X$ and $e^+e^-\to\Lambda h X$. We present the general form of cross sections in terms of structure functions obtained from a general kinematic analysis. This already shows that the produced hyperons can be polarized in three orthogonal directions, i.e., the longitudinal direction along the hyperon momentum, the normal direction of the production plane, and the transverse direction in the production plane. We present the parton model results at the leading twist and leading order in perturbative QCD and provide the expressions for these structure functions and polarizations in terms of parton distribution functions and fragmentation functions. We emphasize in particular that by studying the longitudinal polarization and the transverse polarization in the production plane, we can extract the corresponding chiral-odd fragmentation functions $H_{1Lq}^{\perp\Lambda}$, $H_{1Tq}^{\Lambda}$ and $H_{1Tq}^{\perp\Lambda}$. We also present numerical results of rough estimates utilizing available parameterizations of fragmentation functions and approximations. We discuss how to measure these polarizations and point out in particular that they can be carried out in future EIC and/or $e^+e^-$ annihilation experiments such as Belle. |
hep-ph/9507444 | Chris Traxler | Christoph T. Traxler and Markus H. Thoma | Photon Emission from a Parton Gas at Chemical Non-Equilibrium | 17 pages, uuencoded Postscript file, figures included | Phys.Rev.C53:1348-1352,1996 | 10.1103/PhysRevC.53.1348 | UGI-95-06 | hep-ph nucl-th | null | We compute the hard photon production rate of a chemically non-equilibrated
quark-gluon plasma. We assume that the plasma is already thermally
equilibrated, i.~e. describable by a temperature, but with a phase-space
distribution that deviates from the Fermi/Bose distribution by a time dependent
factor (fugacity). The photon spectrum is obtained by integrating the photon
rate over the space-time evolution of the quark-gluon plasma. Some consequences
for ultrarelativistic heavy ion collisions are discussed.
| [
{
"created": "Fri, 28 Jul 1995 12:11:50 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Traxler",
"Christoph T.",
""
],
[
"Thoma",
"Markus H.",
""
]
] | We compute the hard photon production rate of a chemically non-equilibrated quark-gluon plasma. We assume that the plasma is already thermally equilibrated, i.~e. describable by a temperature, but with a phase-space distribution that deviates from the Fermi/Bose distribution by a time dependent factor (fugacity). The photon spectrum is obtained by integrating the photon rate over the space-time evolution of the quark-gluon plasma. Some consequences for ultrarelativistic heavy ion collisions are discussed. |
hep-ph/0406237 | Tetsuo Nishikawa | Tetsuo Nishikawa | Flavour-singlet g_A and the QCD sum rule incorporating instanton effects | 15 pages, 2 figures | Phys.Lett. B597 (2004) 173-181 | 10.1016/j.physletb.2004.07.003 | KEK-TH-967 | hep-ph | null | We derive a QCD sum rule for the flavour-singlet axial coupling constant
$g_A^{(0)}$ from a two point correlation function of flavour-singlet axial
vector currents in a one-nucleon state. In evaluating the correlation function
by an operator product expansion we take into account the terms up to dimension
6. This correlation function receives an additional two-loop diagram which
comes from an (anti-)instanton. If we do not include it, $g_A^{(0)}$ is
estimated to be 0.8. However, the additional diagram due to instantons
contributes negatively and reduces $g_A^{(0)}$ towards the experimental value.
| [
{
"created": "Tue, 22 Jun 2004 04:42:15 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Nishikawa",
"Tetsuo",
""
]
] | We derive a QCD sum rule for the flavour-singlet axial coupling constant $g_A^{(0)}$ from a two point correlation function of flavour-singlet axial vector currents in a one-nucleon state. In evaluating the correlation function by an operator product expansion we take into account the terms up to dimension 6. This correlation function receives an additional two-loop diagram which comes from an (anti-)instanton. If we do not include it, $g_A^{(0)}$ is estimated to be 0.8. However, the additional diagram due to instantons contributes negatively and reduces $g_A^{(0)}$ towards the experimental value. |
1102.0188 | Maxim Chernodub | M. N. Chernodub and A. S. Nedelin | Phase diagram of chirally imbalanced QCD matter | 6 pages, 4 figures, RevTeX 4.1 | Phys.Rev.D83:105008,2011 | 10.1103/PhysRevD.83.105008 | UUITP-01/11 | hep-ph hep-lat hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We compute the QCD phase diagram in the plane of the chiral chemical
potential and temperature using the linear sigma model coupled to quarks and to
the Polyakov loop. The chiral chemical potential accounts for effects of
imbalanced chirality due to QCD sphaleron transitions which may emerge in
heavy-ion collisions. We found three effects caused by the chiral chemical
potential: the imbalanced chirality (i) tightens the link between deconfinement
and chiral phase transitions; (ii) lowers the common critical temperature;
(iii) strengthens the order of the phase transition by converting the crossover
into the strong first order phase transition passing via the second order
end-point. Since the fermionic determinant with the chiral chemical potential
has no sign problem, the chirally imbalanced QCD matter can be studied in
numerical lattice simulations.
| [
{
"created": "Tue, 1 Feb 2011 15:44:13 GMT",
"version": "v1"
}
] | 2015-03-18 | [
[
"Chernodub",
"M. N.",
""
],
[
"Nedelin",
"A. S.",
""
]
] | We compute the QCD phase diagram in the plane of the chiral chemical potential and temperature using the linear sigma model coupled to quarks and to the Polyakov loop. The chiral chemical potential accounts for effects of imbalanced chirality due to QCD sphaleron transitions which may emerge in heavy-ion collisions. We found three effects caused by the chiral chemical potential: the imbalanced chirality (i) tightens the link between deconfinement and chiral phase transitions; (ii) lowers the common critical temperature; (iii) strengthens the order of the phase transition by converting the crossover into the strong first order phase transition passing via the second order end-point. Since the fermionic determinant with the chiral chemical potential has no sign problem, the chirally imbalanced QCD matter can be studied in numerical lattice simulations. |
0901.1553 | Hanqing Zheng | Ou Zhang, C. Meng, H. Q. Zheng | Ambiversion of X(3872) | Slightly revised version accepted for publication in Physics Letter B | Phys.Lett.B680:453-458,2009 | 10.1016/j.physletb.2009.09.033 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | An analysis including most recent Belle data on X(3872) is performed, using
coupled channel Flatt\'e formula. A third sheet pole close to but
\textit{below} $D^0D^{*0}$ threshold is found, besides the bound state/virtual
state pole discussed in previous literature. The co-existence of two poles near
the $D^0D^{*0}$ threshold indicates that the X(3872) may be of ordinary $c\bar
c$ $2 ^3P_1$ state origin, distorted by strong coupled channel effects. The
latter manifests itself as a molecular bound state (or a virtual state).
| [
{
"created": "Mon, 12 Jan 2009 11:15:35 GMT",
"version": "v1"
},
{
"created": "Sun, 6 Sep 2009 12:24:21 GMT",
"version": "v2"
}
] | 2009-10-06 | [
[
"Zhang",
"Ou",
""
],
[
"Meng",
"C.",
""
],
[
"Zheng",
"H. Q.",
""
]
] | An analysis including most recent Belle data on X(3872) is performed, using coupled channel Flatt\'e formula. A third sheet pole close to but \textit{below} $D^0D^{*0}$ threshold is found, besides the bound state/virtual state pole discussed in previous literature. The co-existence of two poles near the $D^0D^{*0}$ threshold indicates that the X(3872) may be of ordinary $c\bar c$ $2 ^3P_1$ state origin, distorted by strong coupled channel effects. The latter manifests itself as a molecular bound state (or a virtual state). |
1802.01769 | Zhong-Jun Yang | Zhong-Jun Yang, Shu-Min Zhao, Xing-Xing Dong, Xi-Jie Zhan, Hai-Bin
Zhang, Tai-Fu Feng | Corrections to $R_{D}$ and $R_{D^{*}}$ in the BLMSSM | null | Chin.Phys.C42(2018)no.11,113105 | 10.1088/1674-1137/42/11/113104 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The deviation of the measurement of $R_{D}$ ($R_{D^{*}}$) from the Standard
Model (SM) expectation is $2.3\sigma$ ($3.1\sigma$). $R_{D}$ ($R_{D^{*}}$) is
the ratio of the branching fraction of $\overline{B} \rightarrow
D\tau\overline{\nu}_{\tau}$ ($\overline{B} \rightarrow
D^{*}\tau\overline{\nu}_{\tau}$) to that of $\overline{B} \rightarrow
Dl\overline{\nu}_{l}$ ($\overline{B} \rightarrow D^{*}l\overline{\nu}_{l}$),
where $l = e$ or $\mu$. This anomaly may imply the existence of new physics
(NP). In this paper, we restudy this problem in the supersymmetric extension of
the Standard Model with local gauged baryon and lepton numbers (BLMSSM), and
give one-loop corrections to $R_{D}$ ($R_{D^{*}}$).
| [
{
"created": "Tue, 6 Feb 2018 02:56:55 GMT",
"version": "v1"
},
{
"created": "Tue, 19 Jun 2018 05:03:45 GMT",
"version": "v2"
},
{
"created": "Fri, 24 Aug 2018 02:01:31 GMT",
"version": "v3"
},
{
"created": "Thu, 18 Oct 2018 14:08:47 GMT",
"version": "v4"
}
] | 2018-10-30 | [
[
"Yang",
"Zhong-Jun",
""
],
[
"Zhao",
"Shu-Min",
""
],
[
"Dong",
"Xing-Xing",
""
],
[
"Zhan",
"Xi-Jie",
""
],
[
"Zhang",
"Hai-Bin",
""
],
[
"Feng",
"Tai-Fu",
""
]
] | The deviation of the measurement of $R_{D}$ ($R_{D^{*}}$) from the Standard Model (SM) expectation is $2.3\sigma$ ($3.1\sigma$). $R_{D}$ ($R_{D^{*}}$) is the ratio of the branching fraction of $\overline{B} \rightarrow D\tau\overline{\nu}_{\tau}$ ($\overline{B} \rightarrow D^{*}\tau\overline{\nu}_{\tau}$) to that of $\overline{B} \rightarrow Dl\overline{\nu}_{l}$ ($\overline{B} \rightarrow D^{*}l\overline{\nu}_{l}$), where $l = e$ or $\mu$. This anomaly may imply the existence of new physics (NP). In this paper, we restudy this problem in the supersymmetric extension of the Standard Model with local gauged baryon and lepton numbers (BLMSSM), and give one-loop corrections to $R_{D}$ ($R_{D^{*}}$). |
0808.3909 | C. A. Dominguez | C.A. Dominguez, N.F. Nasrallah, R. R\"ontsch K. Schilcher | Light quark masses from QCD sum rules with minimal hadronic bias | In Memoriam: Giuseppe (Beppe) Nardulli, Jan Stern, and Francisco
(Paco) Yndurain. Invited talk given by C.A. Dominguez at QCD-08, 14th
International QCD Conference, Montpellier, France, July 2008 | Nucl.Phys.Proc.Suppl.186:133-136,2009 | 10.1016/j.nuclphysbps.2008.12.031 | UCT-TP-275/08 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The light quark masses are determined using a new QCD Finite Energy Sum Rule
(FESR) in the pseudoscalar channel. This FESR involves an integration kernel
designed to reduce considerably the contribution of the (unmeasured) hadronic
resonance spectral functions. The QCD sector of the FESR includes perturbative
QCD (PQCD) to five loop order, and the leading non-perturbative terms. In the
hadronic sector the dominant contribution is from the pseudoscalar meson pole.
Using Contour Improved Perturbation Theory (CIPT) the results for the quark
masses at a scale of 2 GeV are $m_u(Q= 2 {GeV}) = 2.9 \pm 0.2 {MeV}$, $m_d(Q= 2
{GeV}) = 5.3 \pm 0.4 {MeV}$, and $m_s(Q= 2 {GeV}) = 102 \pm 8 {MeV}$, for
$\Lambda = 381 \pm 16 {MeV}$, corresponding to $\alpha_s(M_\tau^2) = 0.344
\pm0.009$. In this framework the systematic uncertainty in the quark masses
from the unmeasured hadronic resonance spectral function amounts to less than 2
- 3 %. The remaining uncertainties above arise from those in $\Lambda$, the
unknown six-loop PQCD contribution, and the gluon condensate, which are all
potentially subject to improvement.
| [
{
"created": "Thu, 28 Aug 2008 13:50:08 GMT",
"version": "v1"
}
] | 2009-05-12 | [
[
"Dominguez",
"C. A.",
""
],
[
"Nasrallah",
"N. F.",
""
],
[
"Schilcher",
"R. Röntsch K.",
""
]
] | The light quark masses are determined using a new QCD Finite Energy Sum Rule (FESR) in the pseudoscalar channel. This FESR involves an integration kernel designed to reduce considerably the contribution of the (unmeasured) hadronic resonance spectral functions. The QCD sector of the FESR includes perturbative QCD (PQCD) to five loop order, and the leading non-perturbative terms. In the hadronic sector the dominant contribution is from the pseudoscalar meson pole. Using Contour Improved Perturbation Theory (CIPT) the results for the quark masses at a scale of 2 GeV are $m_u(Q= 2 {GeV}) = 2.9 \pm 0.2 {MeV}$, $m_d(Q= 2 {GeV}) = 5.3 \pm 0.4 {MeV}$, and $m_s(Q= 2 {GeV}) = 102 \pm 8 {MeV}$, for $\Lambda = 381 \pm 16 {MeV}$, corresponding to $\alpha_s(M_\tau^2) = 0.344 \pm0.009$. In this framework the systematic uncertainty in the quark masses from the unmeasured hadronic resonance spectral function amounts to less than 2 - 3 %. The remaining uncertainties above arise from those in $\Lambda$, the unknown six-loop PQCD contribution, and the gluon condensate, which are all potentially subject to improvement. |
1011.6507 | Lars T. Kyllingstad | Rashid Khan and Lars T. Kyllingstad | The chiral phase transition and the role of vacuum fluctuations | Talk given at the IX International Conference on Quark Confinement
and the Hadron Spectrum (QCHS9), Madrid, 2010. 3 pages, 4 figures | AIP Conf.Proc.1343:504-506,2011 | 10.1063/1.3575076 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the chiral phase transition in the quark-meson effective model
using optimised perturbation theory to one loop. Certain terms in the free
energy are frequently omitted in calculations, on the assumption that their
contribution is negligible. We show that this is not necessarily the case, and
that the order of the phase transition, as well as the critical temperature,
depends heavily on which contributions are included.
| [
{
"created": "Tue, 30 Nov 2010 09:59:58 GMT",
"version": "v1"
}
] | 2011-07-13 | [
[
"Khan",
"Rashid",
""
],
[
"Kyllingstad",
"Lars T.",
""
]
] | We investigate the chiral phase transition in the quark-meson effective model using optimised perturbation theory to one loop. Certain terms in the free energy are frequently omitted in calculations, on the assumption that their contribution is negligible. We show that this is not necessarily the case, and that the order of the phase transition, as well as the critical temperature, depends heavily on which contributions are included. |
1403.1128 | Sreemoyee Sarkar | Sreemoyee Sarkar | Modification of heavy quark energy loss due to shear flow in hot QCD
plasma | arXiv admin note: text overlap with arXiv:1205.4895 | null | null | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the derivation of heavy quark energy loss in a viscous QCD plasma
using kinetic theory. Shear flow changes both boson and fermion distribution
functions which eventually modify heavy quark energy loss. Due to presence of
non-zero flow gradient in the medium all the bath particles here are out of
equilibrium. In these types of plasmas we show that without plasma screening
effects heavy quark energy loss suffers similar type of infrared divergence as
one encounters in non-viscous plasma. The screening effects are incorporated
consistently through Hard Thermal Loop resummation perturbation theory in the
small-momentum-transfer region to obtain finite leading order result in
$\eta/s$. We also quantify the importance of the result and demonstrate that
shear flow has significant effect on the heavy quark energy loss.
| [
{
"created": "Wed, 5 Mar 2014 13:47:10 GMT",
"version": "v1"
}
] | 2014-03-06 | [
[
"Sarkar",
"Sreemoyee",
""
]
] | We present the derivation of heavy quark energy loss in a viscous QCD plasma using kinetic theory. Shear flow changes both boson and fermion distribution functions which eventually modify heavy quark energy loss. Due to presence of non-zero flow gradient in the medium all the bath particles here are out of equilibrium. In these types of plasmas we show that without plasma screening effects heavy quark energy loss suffers similar type of infrared divergence as one encounters in non-viscous plasma. The screening effects are incorporated consistently through Hard Thermal Loop resummation perturbation theory in the small-momentum-transfer region to obtain finite leading order result in $\eta/s$. We also quantify the importance of the result and demonstrate that shear flow has significant effect on the heavy quark energy loss. |
2307.10361 | Thomas Steingasser | Thomas Steingasser, David I. Kaiser | Higgs Criticality beyond the Standard Model | 17 pages, 7 figures. Minor revisions and references added to match
the published version in Physical Review D | null | null | MIT-CTP/5581 | hep-ph hep-th | http://creativecommons.org/licenses/by/4.0/ | Both parameters in the Higgs field's potential, its mass and quartic
coupling, appear fine-tuned to near-critical values, which gives rise to the
hierarchy problem and the metastability of the electroweak vacuum. Whereas such
behavior appears puzzling in the context of particle physics, it is a common
feature of dynamical systems, which has led to the suggestion that the
parameters of the Higgs potential could be set through some dynamical process.
In this article, we discuss how this notion could be extended to physics beyond
the Standard Model (SM). We first review in which sense the SM Higgs parameters
can be understood as near-critical and show that this notion can be
extrapolated in a unique way for a generic class of SM extensions. Our main
result is a prediction for the parameters of such models in terms of their
corresponding Standard Model effective field theory Wilson coefficients and
corresponding matching scale. For generic models, our result suggests that the
scale of new (bosonic) physics lies close to the instability scale. We explore
the potentially observable consequences of this connection, and illustrate
aspects of our analysis with a concrete example. Lastly, we discuss
implications of our results for several mechanisms of dynamical vacuum
selection associated with various Beyond-Standard-Model (BSM) constructions.
| [
{
"created": "Wed, 19 Jul 2023 18:00:01 GMT",
"version": "v1"
},
{
"created": "Mon, 6 Nov 2023 00:08:13 GMT",
"version": "v2"
}
] | 2023-11-07 | [
[
"Steingasser",
"Thomas",
""
],
[
"Kaiser",
"David I.",
""
]
] | Both parameters in the Higgs field's potential, its mass and quartic coupling, appear fine-tuned to near-critical values, which gives rise to the hierarchy problem and the metastability of the electroweak vacuum. Whereas such behavior appears puzzling in the context of particle physics, it is a common feature of dynamical systems, which has led to the suggestion that the parameters of the Higgs potential could be set through some dynamical process. In this article, we discuss how this notion could be extended to physics beyond the Standard Model (SM). We first review in which sense the SM Higgs parameters can be understood as near-critical and show that this notion can be extrapolated in a unique way for a generic class of SM extensions. Our main result is a prediction for the parameters of such models in terms of their corresponding Standard Model effective field theory Wilson coefficients and corresponding matching scale. For generic models, our result suggests that the scale of new (bosonic) physics lies close to the instability scale. We explore the potentially observable consequences of this connection, and illustrate aspects of our analysis with a concrete example. Lastly, we discuss implications of our results for several mechanisms of dynamical vacuum selection associated with various Beyond-Standard-Model (BSM) constructions. |
1911.10886 | Victor Goncalves | V. P. Goncalves, M. M. Jaime | Photoproduction of pentaquarks states at the LHC | 6 pages, 4 figures. Improved version published in Physics Letters B | null | 10.1016/j.physletb.2020.135447 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper we investigate the production of pentaquark states in the
photon -- proton interactions present in hadronic collisions at the RHIC and
LHC. We consider two phenomenological models for the $J/\Psi$ photoproduction
that consider the presence of the $P_c(4312)$, $P_c(4440)$ and $P_c(4457)$
resonances in the $s$ -- channel of the $\gamma p \rightarrow J/\Psi p$
reaction. The rapidity distribution is estimated for $pA$ collisions at the
RHIC and LHC. Predictions for $pPb$, $Pb \, Ar$ and $Pb \,He$ fixed -- target
collisions at the LHC are also presented. We demonstrate that the experimental
analysis of the $J/\Psi$ photoproduction in fixed -- target collisions can
provide complementary and independent checks on these states, and help to
understand their underlying nature.
| [
{
"created": "Mon, 25 Nov 2019 13:06:36 GMT",
"version": "v1"
},
{
"created": "Wed, 13 May 2020 15:13:01 GMT",
"version": "v2"
}
] | 2020-05-20 | [
[
"Goncalves",
"V. P.",
""
],
[
"Jaime",
"M. M.",
""
]
] | In this paper we investigate the production of pentaquark states in the photon -- proton interactions present in hadronic collisions at the RHIC and LHC. We consider two phenomenological models for the $J/\Psi$ photoproduction that consider the presence of the $P_c(4312)$, $P_c(4440)$ and $P_c(4457)$ resonances in the $s$ -- channel of the $\gamma p \rightarrow J/\Psi p$ reaction. The rapidity distribution is estimated for $pA$ collisions at the RHIC and LHC. Predictions for $pPb$, $Pb \, Ar$ and $Pb \,He$ fixed -- target collisions at the LHC are also presented. We demonstrate that the experimental analysis of the $J/\Psi$ photoproduction in fixed -- target collisions can provide complementary and independent checks on these states, and help to understand their underlying nature. |
0707.0946 | Carlos Merino | C. Merino, C. Pajares, and Yu. M. Shabelski | Open Charm Production in pp and Heavy Ion Collisions in QCD | Talk given at the Ninth Workshop on Non-Perturbative Quantum
Chromodynamics, Paris (France), June 4th-8th, 2007 (8 pages and 3 figures) | ECONFC0706044:20,2007 | null | null | hep-ph | null | The RHIC data on charm production are compared with the kT-factorization
approach predictions, both standard NLO QCD and FONLL. The calculated results
underestimate the STAR Collaboration data. The role of possible nuclear effects
is discussed.
| [
{
"created": "Fri, 6 Jul 2007 11:02:40 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Merino",
"C.",
""
],
[
"Pajares",
"C.",
""
],
[
"Shabelski",
"Yu. M.",
""
]
] | The RHIC data on charm production are compared with the kT-factorization approach predictions, both standard NLO QCD and FONLL. The calculated results underestimate the STAR Collaboration data. The role of possible nuclear effects is discussed. |
2301.09267 | June-Young Kim | Ki-Hoon Hong, June-Young Kim, Hyun-Chul Kim | Two-dimensional charge distributions of the $\Delta$ baryon:
Interpolation between the nonrelativistic and ultrarelativistic limit | 22 pages, 12 figures | null | 10.1103/PhysRevD.107.074004 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate how the charge distributions of both the unpolarized and
transversely polarized $\Delta$ baryon change as the longitudinal
momentum~($P_{z}$) of the $\Delta$ baryon increases from $P_{z}=0$ to
$P_{z}=\infty$ in a Wigner phase-space perspective. When the $\Delta$ baryon is
longitudinally polarized, its two-dimensional charge distribution is kept to be
spherically symmetric with $P_{z}$ varied, whereas when the $\Delta$ baryon is
transversely polarized along the $x$-axis, the quadrupole contribution emerges
at the rest frame ($P_{z}=0$). When $P_{z}$ grows, the electric dipole and
octupole moments are induced. The induced dipole moment dominates over other
higher multipole contributions and governs the deformation of the charge
distribution of the $\Delta$ baryon.
| [
{
"created": "Mon, 23 Jan 2023 04:33:31 GMT",
"version": "v1"
}
] | 2023-04-19 | [
[
"Hong",
"Ki-Hoon",
""
],
[
"Kim",
"June-Young",
""
],
[
"Kim",
"Hyun-Chul",
""
]
] | We investigate how the charge distributions of both the unpolarized and transversely polarized $\Delta$ baryon change as the longitudinal momentum~($P_{z}$) of the $\Delta$ baryon increases from $P_{z}=0$ to $P_{z}=\infty$ in a Wigner phase-space perspective. When the $\Delta$ baryon is longitudinally polarized, its two-dimensional charge distribution is kept to be spherically symmetric with $P_{z}$ varied, whereas when the $\Delta$ baryon is transversely polarized along the $x$-axis, the quadrupole contribution emerges at the rest frame ($P_{z}=0$). When $P_{z}$ grows, the electric dipole and octupole moments are induced. The induced dipole moment dominates over other higher multipole contributions and governs the deformation of the charge distribution of the $\Delta$ baryon. |
1706.06047 | Konrad Tywoniuk | Yacine Mehtar-Tani and Konrad Tywoniuk | Radiative energy loss of neighboring subjets | 34 pages, 15 figures | null | 10.1016/j.nuclphysa.2018.09.041 | INT-PUB-17-022, CERN-TH-2017-134 | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We compute the in-medium energy loss probability distribution of two
neighboring subjets at leading order, in the large-$N_c$ approximation. Our
result exhibits a gradual onset of color decoherence of the system and accounts
for two expected limiting cases. When the angular separation is smaller than
the characteristic angle for medium-induced radiation, the two-pronged
substructure lose energy coherently as a single color charge, namely that of
the parent parton. At large angular separation the two subjets lose energy
independently. Our result is a first step towards quantifying effects of energy
loss as a result of the fluctuation of the multi-parton jet substructure and
therefore goes beyond the standard approach to jet quenching based on single
parton energy loss. We briefly discuss applications to jet observables in
heavy-ion collisions.
| [
{
"created": "Mon, 19 Jun 2017 16:37:10 GMT",
"version": "v1"
},
{
"created": "Fri, 10 Aug 2018 15:35:37 GMT",
"version": "v2"
}
] | 2018-10-17 | [
[
"Mehtar-Tani",
"Yacine",
""
],
[
"Tywoniuk",
"Konrad",
""
]
] | We compute the in-medium energy loss probability distribution of two neighboring subjets at leading order, in the large-$N_c$ approximation. Our result exhibits a gradual onset of color decoherence of the system and accounts for two expected limiting cases. When the angular separation is smaller than the characteristic angle for medium-induced radiation, the two-pronged substructure lose energy coherently as a single color charge, namely that of the parent parton. At large angular separation the two subjets lose energy independently. Our result is a first step towards quantifying effects of energy loss as a result of the fluctuation of the multi-parton jet substructure and therefore goes beyond the standard approach to jet quenching based on single parton energy loss. We briefly discuss applications to jet observables in heavy-ion collisions. |
hep-ph/0001257 | Dmitri Kazakov | D.I. Kazakov (BLTP, JINR, Dubna and ITEP, Moscow) | Supersymmetry in Particle Physics: The Renormalization Group Viewpoint | 45 pages, LaTeX, 11 .eps figures, review talk given at the Conference
``Renormalization Group at the Turn of the Millennium'', Taxco, Mexico,
January 1999 | Phys.Rept.344:309-353,2001 | 10.1016/S0370-1573(00)00129-0 | null | hep-ph | null | An attempt is made to present modern hopes to find manifestation of
supersymmetry, a new symmetry that relates bosons and fermions, in particle
physics from the point of view of renormalization group flow. The Standard
Model of particle interactions is briefly reviewed, the main notions of
supersymmetry are introduced. In more detail the RG flow in the Minimal
Supersymmetric Standard Model is considered. Predictions of particle spectrum
are obtained based on the RG fixed points.
| [
{
"created": "Tue, 25 Jan 2000 12:48:17 GMT",
"version": "v1"
}
] | 2009-09-25 | [
[
"Kazakov",
"D. I.",
"",
"BLTP, JINR, Dubna and ITEP, Moscow"
]
] | An attempt is made to present modern hopes to find manifestation of supersymmetry, a new symmetry that relates bosons and fermions, in particle physics from the point of view of renormalization group flow. The Standard Model of particle interactions is briefly reviewed, the main notions of supersymmetry are introduced. In more detail the RG flow in the Minimal Supersymmetric Standard Model is considered. Predictions of particle spectrum are obtained based on the RG fixed points. |
hep-ph/9405304 | Martin Beneke | M.Beneke, V.M.Braun and V.I.Zakharov | Bloch-Nordsieck cancellations beyond logarithms in heavy particle decays | LATEX, 7 pages, one figure appended as uu-encoded ps-file,
MPI-PhT/94-18 | Phys.Rev.Lett. 73 (1994) 3058-3061 | 10.1103/PhysRevLett.73.3058 | null | hep-ph | null | We investigate the one-loop radiative corrections to the semileptonic decay
of a charged particle at finite gauge boson mass. Extending the Bloch-Nordsieck
cancellation of infrared logarithms, the subsequent non-analytic terms are also
found to vanish after eliminating the pole mass in favor of a mass defined at
short distances. This observation justifies the operator product expansion for
inclusive decays of heavy mesons and implies that infrared effects associated
with the summation of the radiative corrections are suppressed by at least
three powers of the mass of the heavy decaying particle.
| [
{
"created": "Mon, 16 May 1994 15:04:17 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Beneke",
"M.",
""
],
[
"Braun",
"V. M.",
""
],
[
"Zakharov",
"V. I.",
""
]
] | We investigate the one-loop radiative corrections to the semileptonic decay of a charged particle at finite gauge boson mass. Extending the Bloch-Nordsieck cancellation of infrared logarithms, the subsequent non-analytic terms are also found to vanish after eliminating the pole mass in favor of a mass defined at short distances. This observation justifies the operator product expansion for inclusive decays of heavy mesons and implies that infrared effects associated with the summation of the radiative corrections are suppressed by at least three powers of the mass of the heavy decaying particle. |
2404.03666 | Dhananjay Saikumar Mr | Dhananjay Saikumar | Exploring the Frontiers: Challenges and Theories Beyond the Standard
Model | null | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | Quantum Field Theory (QFT) forms the bedrock of the Standard Model (SM) of
particle physics, a powerful framework that delineates the fundamental
constituents and interactions of the universe. However, the SM's narrative is
incomplete, as it conspicuously fails to account for several empirical
phenomena that challenge our current understanding of particle physics. This
review meticulously examines three paramount anomalies that elude SM
predictions: the elusive nature of dark matter, the Higgs boson's anomalously
low mass, and the intricate puzzle of neutrino masses. Through a critical
analysis, it delves into the forefront of theoretical advancements proposed to
bridge these gaps, notably the Weakly Interacting Massive Particles (WIMPs),
Supersymmetry (SUSY), and the intriguing hypothesis of right-handed neutrinos.
By synthesizing current research and theoretical models, this review not only
elucidates these profound mysteries but also underscores the imperative for a
more comprehensive and unified theory of particle physics, setting the stage
for future discoveries and theoretical breakthroughs.
| [
{
"created": "Fri, 16 Feb 2024 17:17:57 GMT",
"version": "v1"
}
] | 2024-04-08 | [
[
"Saikumar",
"Dhananjay",
""
]
] | Quantum Field Theory (QFT) forms the bedrock of the Standard Model (SM) of particle physics, a powerful framework that delineates the fundamental constituents and interactions of the universe. However, the SM's narrative is incomplete, as it conspicuously fails to account for several empirical phenomena that challenge our current understanding of particle physics. This review meticulously examines three paramount anomalies that elude SM predictions: the elusive nature of dark matter, the Higgs boson's anomalously low mass, and the intricate puzzle of neutrino masses. Through a critical analysis, it delves into the forefront of theoretical advancements proposed to bridge these gaps, notably the Weakly Interacting Massive Particles (WIMPs), Supersymmetry (SUSY), and the intriguing hypothesis of right-handed neutrinos. By synthesizing current research and theoretical models, this review not only elucidates these profound mysteries but also underscores the imperative for a more comprehensive and unified theory of particle physics, setting the stage for future discoveries and theoretical breakthroughs. |
hep-ph/0602063 | Kirill Tuchin | Dmitri Kharzeev, Eugene Levin, Kirill Tuchin | Multi-particle Production and Thermalization in High-Energy QCD | 25 pages, 4 figures; typos fixed; discussions expanded; we added a
new section IV in which we argue that at high energies the production
mechanism discussed in the paper is parametrically enhanced by ln(1/x) with
respect to the quasi-classical result | Phys.Rev.C75:044903,2007 | 10.1103/PhysRevC.75.044903 | BNL-NT-06/8, TAUP 2821/06 | hep-ph | null | We argue that multi-particle production in high energy hadron and nuclear
collisions can be considered as proceeding through the production of gluons in
the background classical field. In this approach we derive the gluon spectrum
immediately after the collision and find that at high energies it is
parametrically enhanced by ln(1/x) with respect to the quasi-classical result
(x is the Bjorken variable). We show that the produced gluon spectrum becomes
thermal (in three dimensions) with an effective temperature determined by the
saturation momentum Qs, T= c Qs/2pi during the time ~1/T; we estimate
c=sqrt{2pi}/2 ~ 1.2. Although this result by itself does not imply that the
gluon spectrum will remain thermal at later times, it has an interesting
applications to heavy ion collisions. In particular, we discuss the possibility
of Bose-Einstein condensation of the produced gluon pairs and estimate the
viscosity of the produced gluon system.
| [
{
"created": "Tue, 7 Feb 2006 15:36:51 GMT",
"version": "v1"
},
{
"created": "Wed, 22 Feb 2006 20:49:57 GMT",
"version": "v2"
},
{
"created": "Wed, 28 Feb 2007 20:13:32 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Kharzeev",
"Dmitri",
""
],
[
"Levin",
"Eugene",
""
],
[
"Tuchin",
"Kirill",
""
]
] | We argue that multi-particle production in high energy hadron and nuclear collisions can be considered as proceeding through the production of gluons in the background classical field. In this approach we derive the gluon spectrum immediately after the collision and find that at high energies it is parametrically enhanced by ln(1/x) with respect to the quasi-classical result (x is the Bjorken variable). We show that the produced gluon spectrum becomes thermal (in three dimensions) with an effective temperature determined by the saturation momentum Qs, T= c Qs/2pi during the time ~1/T; we estimate c=sqrt{2pi}/2 ~ 1.2. Although this result by itself does not imply that the gluon spectrum will remain thermal at later times, it has an interesting applications to heavy ion collisions. In particular, we discuss the possibility of Bose-Einstein condensation of the produced gluon pairs and estimate the viscosity of the produced gluon system. |
hep-ph/0506281 | Ivan Vitev | Ivan Vitev | Large angle hadron correlations from medium-induced gluon radiation | To appear in the proceedings of the MIT workshop "Correlations and
Fluctuations 2005". 10 pages, 5 eps figures | J.Phys.Conf.Ser. 27 (2005) 11-21 | 10.1088/1742-6596/27/1/002 | LA-UR-05-0621 | hep-ph | null | Final state medium-induced gluon radiation in ultradense nuclear matter is
shown to favor large angle emission when compared to vacuum bremsstrahlung due
to the suppression of collinear gluons. In a simple model of momentum transfers
from the medium to the jet+gluon system the phase space distribution of
non-Abelian bremsstrahlung is examined to first order in opacity. Perturbative
expression for the contribution of the hadronic fragments from medium-induced
gluons to the back-to-back particle correlations is derived. It is found that
in the limit of large jet energy loss gluon radiation determines the yield and
angular distribution of $|\Delta \phi | \geq \frac{\pi}{2}$ di-hadrons to high
transverse momenta $p_{T_2}$ of the associated particles. Clear transition from
enhancement to suppression of the away-side di-hadron correlations is
established at moderate $p_{T_2}$ and its experimentally accessible features
are predicted versus the trigger particle momentum $p_{T_1}$. The measured
away-side correlation function is shown to be sensitive to the broad rapidity
distribution of di-jets and their vacuum and medium-induced acoplanarity.
| [
{
"created": "Mon, 27 Jun 2005 22:10:18 GMT",
"version": "v1"
}
] | 2009-11-11 | [
[
"Vitev",
"Ivan",
""
]
] | Final state medium-induced gluon radiation in ultradense nuclear matter is shown to favor large angle emission when compared to vacuum bremsstrahlung due to the suppression of collinear gluons. In a simple model of momentum transfers from the medium to the jet+gluon system the phase space distribution of non-Abelian bremsstrahlung is examined to first order in opacity. Perturbative expression for the contribution of the hadronic fragments from medium-induced gluons to the back-to-back particle correlations is derived. It is found that in the limit of large jet energy loss gluon radiation determines the yield and angular distribution of $|\Delta \phi | \geq \frac{\pi}{2}$ di-hadrons to high transverse momenta $p_{T_2}$ of the associated particles. Clear transition from enhancement to suppression of the away-side di-hadron correlations is established at moderate $p_{T_2}$ and its experimentally accessible features are predicted versus the trigger particle momentum $p_{T_1}$. The measured away-side correlation function is shown to be sensitive to the broad rapidity distribution of di-jets and their vacuum and medium-induced acoplanarity. |
1902.08766 | Cheng-Jun Xia | Cheng-Jun Xia and Toshiki Maruyama and Nobutoshi Yasutake and
Toshitaka Tatsumi | Constraining quark-hadron interface tension in the multi-messenger era | null | Phys. Rev. D 99, 103017 (2019) | 10.1103/PhysRevD.99.103017 | null | hep-ph astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the interface effects of quark-hadron mixed phase in compact stars.
The properties of nuclear matter are obtained based on the
relativistic-mean-field model. For the quark phase, we adopt perturbation model
with running quark masses and coupling constant. At certain choices of
parameter sets, it is found that varying the quark-hadron interface tension
will have sizable effects on the radii ($\Delta R \approx 600$ m) and tidal
deformabilities ($\Delta \Lambda/\Lambda \approx 50\%$) of hybrid stars. These
provide possibilities for us to constrain the quark-hadron interface tension
with future gravitational wave observations as well as the ongoing NICER
mission.
| [
{
"created": "Sat, 23 Feb 2019 09:40:18 GMT",
"version": "v1"
},
{
"created": "Sat, 1 Jun 2019 08:50:20 GMT",
"version": "v2"
}
] | 2019-06-05 | [
[
"Xia",
"Cheng-Jun",
""
],
[
"Maruyama",
"Toshiki",
""
],
[
"Yasutake",
"Nobutoshi",
""
],
[
"Tatsumi",
"Toshitaka",
""
]
] | We study the interface effects of quark-hadron mixed phase in compact stars. The properties of nuclear matter are obtained based on the relativistic-mean-field model. For the quark phase, we adopt perturbation model with running quark masses and coupling constant. At certain choices of parameter sets, it is found that varying the quark-hadron interface tension will have sizable effects on the radii ($\Delta R \approx 600$ m) and tidal deformabilities ($\Delta \Lambda/\Lambda \approx 50\%$) of hybrid stars. These provide possibilities for us to constrain the quark-hadron interface tension with future gravitational wave observations as well as the ongoing NICER mission. |
1112.1340 | Claudia Hagedorn | Reinier de Adelhart Toorop, Ferruccio Feruglio, Claudia Hagedorn | Finite Modular Groups and Lepton Mixing | 27 pages + 8 pages of appendices, 1 figure | null | 10.1016/j.nuclphysb.2012.01.017 | DFPD-11/TH/18 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study lepton mixing patterns which are derived from finite modular groups
Gamma_N, requiring subgroups G_nu and G_e to be preserved in the neutrino and
charged lepton sectors, respectively. We show that only six groups Gamma_N with
N=3,4,5,7,8,16 are relevant. A comprehensive analysis is presented for G_e
arbitrary and G_nu=Z2 x Z2, as demanded if neutrinos are Majorana particles. We
discuss interesting patterns arising from both groups G_e and G_nu being
arbitrary. Several of the most promising patterns are specific deviations from
tri-bimaximal mixing, all predicting theta_13 non-zero as favoured by the
latest experimental data. We also comment on prospects to extend this idea to
the quark sector.
| [
{
"created": "Tue, 6 Dec 2011 16:37:40 GMT",
"version": "v1"
}
] | 2015-06-03 | [
[
"Toorop",
"Reinier de Adelhart",
""
],
[
"Feruglio",
"Ferruccio",
""
],
[
"Hagedorn",
"Claudia",
""
]
] | We study lepton mixing patterns which are derived from finite modular groups Gamma_N, requiring subgroups G_nu and G_e to be preserved in the neutrino and charged lepton sectors, respectively. We show that only six groups Gamma_N with N=3,4,5,7,8,16 are relevant. A comprehensive analysis is presented for G_e arbitrary and G_nu=Z2 x Z2, as demanded if neutrinos are Majorana particles. We discuss interesting patterns arising from both groups G_e and G_nu being arbitrary. Several of the most promising patterns are specific deviations from tri-bimaximal mixing, all predicting theta_13 non-zero as favoured by the latest experimental data. We also comment on prospects to extend this idea to the quark sector. |
0901.3528 | Dennis D. Dietrich | Dennis D. Dietrich and Matti Jarvinen | Pion masses in quasiconformal gauge field theories | 4 pages, 1 figure | Phys.Rev.D79:057903,2009 | 10.1103/PhysRevD.79.057903 | CP3-Origins: 2009-4 | hep-ph hep-th nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study modifications to Weinberg-like sum rules in quasiconformal gauge
field theories. Beyond the two Weinberg sum rules and the oblique S parameter
we study the pion mass and the X parameter. Especially, we evaluate the pion
mass for walking technicolour theories, in particular also minimal walking
technicolour, and find contributions of the order of up to several hundred GeV.
| [
{
"created": "Thu, 22 Jan 2009 18:27:36 GMT",
"version": "v1"
}
] | 2009-07-30 | [
[
"Dietrich",
"Dennis D.",
""
],
[
"Jarvinen",
"Matti",
""
]
] | We study modifications to Weinberg-like sum rules in quasiconformal gauge field theories. Beyond the two Weinberg sum rules and the oblique S parameter we study the pion mass and the X parameter. Especially, we evaluate the pion mass for walking technicolour theories, in particular also minimal walking technicolour, and find contributions of the order of up to several hundred GeV. |
hep-ph/9907272 | Otto Kong | Ashok Das and Otto C. W. Kong (Rochester U.) | On Neutrino Masses and Mixings from Extra Dimensions | 16 pages latex, no figure; small modifications in discussions;
version to appear in Phys.Lett. B | Phys.Lett. B470 (1999) 149-156 | 10.1016/S0370-2693(99)01340-4 | UR-1576 | hep-ph | null | In the framework of a Kaluza-Klein type theory with the Standard Model fields
localized on a 4-dimensional section while gravity propagates in a full
$4+\delta$-dimensional space-time, we examine a mechanism of naturally small
neutrino mass generation through couplings of Standard Model singlet fermion(s)
living also in the full space-time. A numerical studies is carried out on the
charged current universality constraint from the ratio of pion decay partial
widths. The bounds obtained on the fundamental mass scale could be stringent.
| [
{
"created": "Wed, 7 Jul 1999 20:30:25 GMT",
"version": "v1"
},
{
"created": "Fri, 12 Nov 1999 16:46:19 GMT",
"version": "v2"
}
] | 2009-10-31 | [
[
"Das",
"Ashok",
"",
"Rochester U."
],
[
"Kong",
"Otto C. W.",
"",
"Rochester U."
]
] | In the framework of a Kaluza-Klein type theory with the Standard Model fields localized on a 4-dimensional section while gravity propagates in a full $4+\delta$-dimensional space-time, we examine a mechanism of naturally small neutrino mass generation through couplings of Standard Model singlet fermion(s) living also in the full space-time. A numerical studies is carried out on the charged current universality constraint from the ratio of pion decay partial widths. The bounds obtained on the fundamental mass scale could be stringent. |
hep-ph/9612441 | Ming Lu | C. Glenn Boyd, Ming Lu, Martin J. Savage | Heavy Baryon Mixing in Chiral Perturbation Theory | 10 pages, LaTex, uses revtex, two eps figures | Phys.Rev.D55:5474-5478,1997 | 10.1103/PhysRevD.55.5474 | CMU-HEP96-15, DOE/ER/41014-06-N97 | hep-ph | null | We discuss the SU(3) and heavy quark spin-symmetry breaking mixing between
the Xi_c and Xi'_c charmed baryons. Chromomagnetic hyperfine interactions are
the leading source of spin-symmetry breaking and together with the SU(3)
breaking mass differences between the lightest pseudo-Goldstone bosons gives
the leading contribution to the mixing. Such contributions are computed in
chiral perturbation theory and compared to quark model expectations. We also
compute the leading contribution to the semileptonic decay Xi_b -> Xi'_c l nu
at zero recoil, and find that it is an order of magnitude smaller than naive
power counting would suggest. It appears that Xi_b -> Xi'_c l nu is dominated
by incalculable counterterms, and we discuss the implications for quark models
based on the essential role of hyperfine interactions.
| [
{
"created": "Fri, 20 Dec 1996 22:42:54 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"Boyd",
"C. Glenn",
""
],
[
"Lu",
"Ming",
""
],
[
"Savage",
"Martin J.",
""
]
] | We discuss the SU(3) and heavy quark spin-symmetry breaking mixing between the Xi_c and Xi'_c charmed baryons. Chromomagnetic hyperfine interactions are the leading source of spin-symmetry breaking and together with the SU(3) breaking mass differences between the lightest pseudo-Goldstone bosons gives the leading contribution to the mixing. Such contributions are computed in chiral perturbation theory and compared to quark model expectations. We also compute the leading contribution to the semileptonic decay Xi_b -> Xi'_c l nu at zero recoil, and find that it is an order of magnitude smaller than naive power counting would suggest. It appears that Xi_b -> Xi'_c l nu is dominated by incalculable counterterms, and we discuss the implications for quark models based on the essential role of hyperfine interactions. |
0706.2694 | Robert Foot | R. Foot | Mirror dark matter | about 7 pages | Int.J.Mod.Phys.A22:4951-4957,2007 | 10.1142/S0217751X0703830X | null | hep-ph astro-ph | null | A mirror sector of particles and forces provides a simple explanation of the
inferred dark matter of the Universe. The status of this theory is reviewed -
with emphasis on how the theory explains the impressive DAMA/NaI annual
modulation signal, whilst also being consistent with the null results of the
other direct detection experiments.
| [
{
"created": "Tue, 19 Jun 2007 00:35:29 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Foot",
"R.",
""
]
] | A mirror sector of particles and forces provides a simple explanation of the inferred dark matter of the Universe. The status of this theory is reviewed - with emphasis on how the theory explains the impressive DAMA/NaI annual modulation signal, whilst also being consistent with the null results of the other direct detection experiments. |
1212.4383 | Javier Vijande Asenjo | J. Vijande, A. Valcarce, T.F. Caram\'es, H. Garcilazo | Heavy hadron spectroscopy: a quark model perspective | Invited talk at the 11th International Conference on Hypernuclear and
Strange Particle Physics, Barcelona (Spain) | Int. J. Mod. Phys. E Vol. 22 (2013) 1330011 | 10.1142/S0218301313300117 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present recent results of hadron spectroscopy and hadron-hadron
interaction from the perspective of constituent quark models. We pay special
attention to the role played by higher order Fock space components in the
hadron spectra and the connection of this extension with the hadron-hadron
interaction. The main goal of our description is to obtain a coherent
understanding of the lowenergy hadron phenomenology without enforcing any
particular model, to constrain its characteristics and learn about low-energy
realization of the theory.
| [
{
"created": "Tue, 18 Dec 2012 15:32:11 GMT",
"version": "v1"
}
] | 2015-06-12 | [
[
"Vijande",
"J.",
""
],
[
"Valcarce",
"A.",
""
],
[
"Caramés",
"T. F.",
""
],
[
"Garcilazo",
"H.",
""
]
] | We present recent results of hadron spectroscopy and hadron-hadron interaction from the perspective of constituent quark models. We pay special attention to the role played by higher order Fock space components in the hadron spectra and the connection of this extension with the hadron-hadron interaction. The main goal of our description is to obtain a coherent understanding of the lowenergy hadron phenomenology without enforcing any particular model, to constrain its characteristics and learn about low-energy realization of the theory. |
hep-ph/0509064 | Tomohiro Matsuda | Tomohiro Matsuda | Dark matter production from cosmic necklaces | 27 pages, 5 figures, added many comments and 3 figures, accepted for
publication in JCAP | JCAP 0604 (2006) 005 | 10.1088/1475-7516/2006/04/005 | null | hep-ph astro-ph hep-th | null | Cosmic strings have gained a great interest, since they are formed in a large
class of brane inflationary models. The most interesting story is that cosmic
strings in brane models are distinguished in future cosmological observations.
If the strings in brane models are branes or superstrings that can move along
compactified space, and also if there are degenerated vacua along the
compactified space, kinks interpolate between degenerated vacua become
``beads'' on the strings. In this case, strings turn into necklaces. In the
case that the compact manifold in not simply connected, a string loop that
winds around a nontrivial circle is stable due to the topological reason. Since
the existence of the (quasi-)degenerated vacua and the nontrivial circle is a
common feature of the brane models, it is important to study cosmological
constraints on the cosmic necklaces and the stable winding states. In this
paper, we consider dark matter production from loops of the cosmic necklaces.
Our result suggests that necklaces can put stringent bound on certain kinds of
brane models.
| [
{
"created": "Wed, 7 Sep 2005 11:21:25 GMT",
"version": "v1"
},
{
"created": "Mon, 28 Nov 2005 10:36:55 GMT",
"version": "v2"
},
{
"created": "Thu, 29 Dec 2005 03:42:52 GMT",
"version": "v3"
},
{
"created": "Sun, 2 Apr 2006 05:28:12 GMT",
"version": "v4"
}
] | 2009-11-11 | [
[
"Matsuda",
"Tomohiro",
""
]
] | Cosmic strings have gained a great interest, since they are formed in a large class of brane inflationary models. The most interesting story is that cosmic strings in brane models are distinguished in future cosmological observations. If the strings in brane models are branes or superstrings that can move along compactified space, and also if there are degenerated vacua along the compactified space, kinks interpolate between degenerated vacua become ``beads'' on the strings. In this case, strings turn into necklaces. In the case that the compact manifold in not simply connected, a string loop that winds around a nontrivial circle is stable due to the topological reason. Since the existence of the (quasi-)degenerated vacua and the nontrivial circle is a common feature of the brane models, it is important to study cosmological constraints on the cosmic necklaces and the stable winding states. In this paper, we consider dark matter production from loops of the cosmic necklaces. Our result suggests that necklaces can put stringent bound on certain kinds of brane models. |
1312.2212 | Vsevolod Orlovsky | M.A. Andreichikov, B.O. Kerbikov, V.D. Orlovsky, Yu.A. Simonov | Neutron in Strong Magnetic Fields | 29 pages, 4 figures | Phys. Rev. D 89, 074033 (2014) | 10.1103/PhysRevD.89.074033 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Relativistic world-line Hamiltonian for strongly interacting 3q systems in
magnetic field is derived from the path integral for the corresponding Green's
function. The neutral baryon Hamiltonian in magnetic field obeys the
pseudomomentum conservation and allows a factorization of the c.m. and internal
motion. The resulting expression for the baryon mass in magnetic field is
written explicitly with the account of hyperfine, OPE and OGE (color Coulomb)
interaction. The neutron mass is fast decreasing with magnetic field, losing
1/2 of its value at eB~0.25 GeV^2 and is nearly zero at eB~0.5 GeV^2. Possible
physical consequences of the calculated mass trajectory of the neutron, M_n(B),
are presented and discussed.
| [
{
"created": "Sun, 8 Dec 2013 13:43:01 GMT",
"version": "v1"
}
] | 2014-04-23 | [
[
"Andreichikov",
"M. A.",
""
],
[
"Kerbikov",
"B. O.",
""
],
[
"Orlovsky",
"V. D.",
""
],
[
"Simonov",
"Yu. A.",
""
]
] | Relativistic world-line Hamiltonian for strongly interacting 3q systems in magnetic field is derived from the path integral for the corresponding Green's function. The neutral baryon Hamiltonian in magnetic field obeys the pseudomomentum conservation and allows a factorization of the c.m. and internal motion. The resulting expression for the baryon mass in magnetic field is written explicitly with the account of hyperfine, OPE and OGE (color Coulomb) interaction. The neutron mass is fast decreasing with magnetic field, losing 1/2 of its value at eB~0.25 GeV^2 and is nearly zero at eB~0.5 GeV^2. Possible physical consequences of the calculated mass trajectory of the neutron, M_n(B), are presented and discussed. |
1809.01140 | Patrick Komiske | Patrick T. Komiske, Eric M. Metodiev, Jesse Thaler | An operational definition of quark and gluon jets | 38 pages, 10 figures, 1 table; v2: updated to match JHEP version | JHEP 11 (2018) 059 | 10.1007/JHEP11(2018)059 | MIT-CTP 5042 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | While "quark" and "gluon" jets are often treated as separate, well-defined
objects in both theoretical and experimental contexts, no precise, practical,
and hadron-level definition of jet flavor presently exists. To remedy this
issue, we develop and advocate for a data-driven, operational definition of
quark and gluon jets that is readily applicable at colliders. Rather than
specifying a per-jet flavor label, we aggregately define quark and gluon jets
at the distribution level in terms of measured hadronic cross sections.
Intuitively, quark and gluon jets emerge as the two maximally separable
categories within two jet samples in data. Benefiting from recent work on
data-driven classifiers and topic modeling for jets, we show that the practical
tools needed to implement our definition already exist for experimental
applications. As an informative example, we demonstrate the power of our
operational definition using Z+jet and dijet samples, illustrating that pure
quark and gluon distributions and fractions can be successfully extracted in a
fully well-defined manner.
| [
{
"created": "Tue, 4 Sep 2018 18:00:00 GMT",
"version": "v1"
},
{
"created": "Fri, 9 Nov 2018 23:14:37 GMT",
"version": "v2"
}
] | 2018-11-13 | [
[
"Komiske",
"Patrick T.",
""
],
[
"Metodiev",
"Eric M.",
""
],
[
"Thaler",
"Jesse",
""
]
] | While "quark" and "gluon" jets are often treated as separate, well-defined objects in both theoretical and experimental contexts, no precise, practical, and hadron-level definition of jet flavor presently exists. To remedy this issue, we develop and advocate for a data-driven, operational definition of quark and gluon jets that is readily applicable at colliders. Rather than specifying a per-jet flavor label, we aggregately define quark and gluon jets at the distribution level in terms of measured hadronic cross sections. Intuitively, quark and gluon jets emerge as the two maximally separable categories within two jet samples in data. Benefiting from recent work on data-driven classifiers and topic modeling for jets, we show that the practical tools needed to implement our definition already exist for experimental applications. As an informative example, we demonstrate the power of our operational definition using Z+jet and dijet samples, illustrating that pure quark and gluon distributions and fractions can be successfully extracted in a fully well-defined manner. |
1102.2896 | James Unwin | James Unwin | Vacuum stability and the Cholesky decomposition | 7 pages | Eur.Phys.J.C71:1663,2011 | 10.1140/epjc/s10052-011-1663-9 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss how the Cholesky decomposition may be used to ascertain whether a
critical point of the field theory scalar potential provides a stable vacuum
configuration. We then use this method to derive the stability conditions in a
specific example.
| [
{
"created": "Mon, 14 Feb 2011 21:01:03 GMT",
"version": "v1"
}
] | 2011-06-13 | [
[
"Unwin",
"James",
""
]
] | We discuss how the Cholesky decomposition may be used to ascertain whether a critical point of the field theory scalar potential provides a stable vacuum configuration. We then use this method to derive the stability conditions in a specific example. |
hep-ph/0110272 | Anjan Joshipura | Srubabati Goswami and Anjan S. Joshipura | Neutrino Anomalies and Quasi-Dirac neutrinos | 15 pages, LATEX, minor corrections; addition of few references | Phys.Rev. D65 (2002) 073025 | 10.1103/PhysRevD.65.073025 | null | hep-ph | null | We discuss possibility of describing solar, atmospheric and LSND results with
four neutrinos forming two quasi-degenerate pairs. The simplest versions of
this 2+2 scheme with either $\nu_e$ or $\nu_\mu$ mixing exclusively with
sterile neutrino is disfavored by the SNO and atmospheric neutrino results
respectively. A generalized scheme with sterile state participating in both the
solar and atmospheric oscillations is still allowed. We show thasolar and
atmospheric oscillations is still allowed. We show that the complex pattern of
mixing needed for this purpose follows from a simple L_e+L_\mu-L_\tau-L_s
symmetry. Specific form of L_e+L_\mu-L_\tau-L_s symmetric mass matrix is
determined from experimental results. Two theoretical schemes which lead to
this form and a proper breaking of L_e+L_\mu-L_\tau-L_s symmetry are discussed.
| [
{
"created": "Sat, 20 Oct 2001 08:12:40 GMT",
"version": "v1"
},
{
"created": "Tue, 6 Nov 2001 08:39:08 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Goswami",
"Srubabati",
""
],
[
"Joshipura",
"Anjan S.",
""
]
] | We discuss possibility of describing solar, atmospheric and LSND results with four neutrinos forming two quasi-degenerate pairs. The simplest versions of this 2+2 scheme with either $\nu_e$ or $\nu_\mu$ mixing exclusively with sterile neutrino is disfavored by the SNO and atmospheric neutrino results respectively. A generalized scheme with sterile state participating in both the solar and atmospheric oscillations is still allowed. We show thasolar and atmospheric oscillations is still allowed. We show that the complex pattern of mixing needed for this purpose follows from a simple L_e+L_\mu-L_\tau-L_s symmetry. Specific form of L_e+L_\mu-L_\tau-L_s symmetric mass matrix is determined from experimental results. Two theoretical schemes which lead to this form and a proper breaking of L_e+L_\mu-L_\tau-L_s symmetry are discussed. |
2205.13889 | Maciej Rybczynski | Maciej Rybczy\'nski and Zbigniew W{\l}odarczyk | Non-exponential decay in classical stochastic processes with memory | null | Acta Phys. Pol. B 54, 2-A2 (2023) | 10.5506/APhysPolB.54.2-A2 | null | hep-ph math.PR | http://creativecommons.org/licenses/by/4.0/ | The initial time-dependence of a state in circumstances where it makes
transitions to, or decay to, a second state has been investigated. In classical
stochastic processes, the observed time dependence of transition or decay
proportional to $t^2$ is attributed to the noise with memory. In contrast to
quantum mechanics, the quadratic form of initial decay is unable to decelerate
the evolution of the system.
| [
{
"created": "Fri, 27 May 2022 10:41:26 GMT",
"version": "v1"
},
{
"created": "Mon, 12 Sep 2022 14:56:05 GMT",
"version": "v2"
},
{
"created": "Tue, 7 Mar 2023 14:43:16 GMT",
"version": "v3"
}
] | 2023-03-15 | [
[
"Rybczyński",
"Maciej",
""
],
[
"Włodarczyk",
"Zbigniew",
""
]
] | The initial time-dependence of a state in circumstances where it makes transitions to, or decay to, a second state has been investigated. In classical stochastic processes, the observed time dependence of transition or decay proportional to $t^2$ is attributed to the noise with memory. In contrast to quantum mechanics, the quadratic form of initial decay is unable to decelerate the evolution of the system. |
1010.0272 | Matti Jarvinen | Matti Jarvinen | Electroweak phase transition in technicolor | 6 pages, 4 figures. Talk at PASCOS 2010 conference, Valencia, 19-23
July 2010 | null | 10.1088/1742-6596/259/1/012053 | CP3-Origins-2010-42, CCTP-2010-14 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Several phenomenologically viable walking technicolor models have been
proposed recently. I demonstrate that these models can have first order
electroweak phase transitions, which are sufficiently strong for electroweak
baryogenesis. Strong dynamics can also lead to several separate transitions at
the electroweak scale, with the possibility of a temporary restoration and an
extra breaking of the electroweak symmetry. First order phase transitions will
produce gravitational waves, which may be detectable at future experiments.
| [
{
"created": "Fri, 1 Oct 2010 22:25:14 GMT",
"version": "v1"
}
] | 2015-05-20 | [
[
"Jarvinen",
"Matti",
""
]
] | Several phenomenologically viable walking technicolor models have been proposed recently. I demonstrate that these models can have first order electroweak phase transitions, which are sufficiently strong for electroweak baryogenesis. Strong dynamics can also lead to several separate transitions at the electroweak scale, with the possibility of a temporary restoration and an extra breaking of the electroweak symmetry. First order phase transitions will produce gravitational waves, which may be detectable at future experiments. |
2011.12123 | Nils Hermansson-Truedsson | Johan Bijnens, Nils Hermansson-Truedsson, Laetitia Laub, Antonio
Rodriguez-Sanchez | Short-distance HLbL contributions to the muon g-2 | Proceedings for talk given at 23rd International Conference in
Quantum Chromodynamics (QCD 20), 27 October - 30 October 2020, Montpellier -
FR | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | The current $3.7\sigma$ discrepancy between the Standard Model prediction and
the experimental value of the muon anomalous magnetic moment could be a hint
for the existence of new physics. The hadronic light-by-light contribution is
one of the pieces requiring improved precision on the theory side, and an
important step is to derive short-distance constraints for this quantity
containing four electromagnetic currents. Here, we derive such short-distance
constraints for three large photon loop virtualities and the external fourth
photon in the static limit. The static photon is considered as a background
field and we construct a systematic operator product expansion in the presence
of this field. We show that the massless quark loop, i.e. the leading term, is
numerically dominant over non-perturbative contributions up to next-to-next-to
leading order, both those suppressed by quark masses and those that are not.
| [
{
"created": "Tue, 24 Nov 2020 14:30:45 GMT",
"version": "v1"
}
] | 2020-11-25 | [
[
"Bijnens",
"Johan",
""
],
[
"Hermansson-Truedsson",
"Nils",
""
],
[
"Laub",
"Laetitia",
""
],
[
"Rodriguez-Sanchez",
"Antonio",
""
]
] | The current $3.7\sigma$ discrepancy between the Standard Model prediction and the experimental value of the muon anomalous magnetic moment could be a hint for the existence of new physics. The hadronic light-by-light contribution is one of the pieces requiring improved precision on the theory side, and an important step is to derive short-distance constraints for this quantity containing four electromagnetic currents. Here, we derive such short-distance constraints for three large photon loop virtualities and the external fourth photon in the static limit. The static photon is considered as a background field and we construct a systematic operator product expansion in the presence of this field. We show that the massless quark loop, i.e. the leading term, is numerically dominant over non-perturbative contributions up to next-to-next-to leading order, both those suppressed by quark masses and those that are not. |
hep-ph/0304286 | Yasuhiro Okada | Yasuhiro Okada (KEK) | Theoretical introduction to linear collider phyiscs | 18 pages, 12 figures, talk given at International Workshop on Linear
Colliders, August 26 - 30, 2002, Jeju Island, Korea | null | null | KEK-TH-884 | hep-ph | null | Physics at an e^+e^- linear collider is described as a theoretical
introduction to Linear Collider Workshop 2002.
| [
{
"created": "Wed, 30 Apr 2003 11:31:33 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Okada",
"Yasuhiro",
"",
"KEK"
]
] | Physics at an e^+e^- linear collider is described as a theoretical introduction to Linear Collider Workshop 2002. |
hep-ph/0312008 | Hitoshi Murayama | Hitoshi Murayama | Impact of Neutrino Oscillation Measurements on Theory | 8 pages, uses aipproc, 6 figures. Plenary talk presented at Nufact
03, 5th International Workshop on Neutrino Factories & Superbeams, Columbia
University, New York, 5-11 June 2003 | AIP Conf.Proc.721:122-129,2004 | 10.1063/1.1818385 | null | hep-ph | null | Neutrino oscillation data had been a big surprise to theorists, and indeed
they have ongoing impact on theory. I review what the impact has been, and what
measurements will have critical impact on theory in the future.
| [
{
"created": "Sun, 30 Nov 2003 04:29:00 GMT",
"version": "v1"
}
] | 2009-09-29 | [
[
"Murayama",
"Hitoshi",
""
]
] | Neutrino oscillation data had been a big surprise to theorists, and indeed they have ongoing impact on theory. I review what the impact has been, and what measurements will have critical impact on theory in the future. |
2003.08200 | Piotr Lebiedowicz | Piotr Lebiedowicz, Rafa{\l} Maciu{\l}a, Antoni Szczurek | Production of $f_{0}(980)$ meson at the LHC: Color evaporation versus
color-singlet gluon-gluon fusion | 20 pages, 12 figures | Physics Letters B 806 (2020) 135475 | 10.1016/j.physletb.2020.135475 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The production of the $f_{0}(980)$ meson at high energies is not well
understood. We investigate two different potential mechanisms for inclusive
scalar meson production in the $k_t$-factorization approach: color-singlet
gluon-gluon fusion and color evaporation model. The $\gamma^* \gamma^* \to
f_0(980)$ form factor(s) can be constraint from the $f_0(980)$ radiative decay
width. The $g^* g^* \to f_0(980)$ form factors are obtained by a replacement of
$\alpha_{\rm{em}}$ electromagnetic coupling constant by $\alpha_{\rm{s}}$
strong coupling constant and appropriate color factors. The form factors for
the two couplings are parametrized with a function motivated by recent results
for scalar quarkonia. The differential cross sections are calculated in the
$k_t$-factorization approach with modern unintegrated gluon distributions.
Unlike for quarkonia it seems rather difficult to describe a preliminary ALICE
data for inclusive production of $f_0(980)$ exclusively by the color singlet
gluon-gluon fusion mechanism. Two different scenarios for flavor structure of
$f_0(980)$ are considered in this context. We consider also mechanism of fusion
of quark-antiquark associated with soft gluon emission in a phenomenological
color evaporation model (CEM) used sometimes for quarkonium production. Here we
use $k_t$-factorization version of CEM to include higher-order contributions.
In addition, for comparison we consider also NLO collinear approach with $q
\bar{q} q$ and $q \bar{q} g$ color octet partonic final states. Both approaches
lead to a similar result. However, very large probabilities are required to
describe the preliminary ALICE data. The pomeron-pomeron fusion mechanism is
also discussed and results are quantified.
| [
{
"created": "Wed, 18 Mar 2020 13:12:01 GMT",
"version": "v1"
},
{
"created": "Sun, 17 May 2020 17:13:58 GMT",
"version": "v2"
}
] | 2020-05-19 | [
[
"Lebiedowicz",
"Piotr",
""
],
[
"Maciuła",
"Rafał",
""
],
[
"Szczurek",
"Antoni",
""
]
] | The production of the $f_{0}(980)$ meson at high energies is not well understood. We investigate two different potential mechanisms for inclusive scalar meson production in the $k_t$-factorization approach: color-singlet gluon-gluon fusion and color evaporation model. The $\gamma^* \gamma^* \to f_0(980)$ form factor(s) can be constraint from the $f_0(980)$ radiative decay width. The $g^* g^* \to f_0(980)$ form factors are obtained by a replacement of $\alpha_{\rm{em}}$ electromagnetic coupling constant by $\alpha_{\rm{s}}$ strong coupling constant and appropriate color factors. The form factors for the two couplings are parametrized with a function motivated by recent results for scalar quarkonia. The differential cross sections are calculated in the $k_t$-factorization approach with modern unintegrated gluon distributions. Unlike for quarkonia it seems rather difficult to describe a preliminary ALICE data for inclusive production of $f_0(980)$ exclusively by the color singlet gluon-gluon fusion mechanism. Two different scenarios for flavor structure of $f_0(980)$ are considered in this context. We consider also mechanism of fusion of quark-antiquark associated with soft gluon emission in a phenomenological color evaporation model (CEM) used sometimes for quarkonium production. Here we use $k_t$-factorization version of CEM to include higher-order contributions. In addition, for comparison we consider also NLO collinear approach with $q \bar{q} q$ and $q \bar{q} g$ color octet partonic final states. Both approaches lead to a similar result. However, very large probabilities are required to describe the preliminary ALICE data. The pomeron-pomeron fusion mechanism is also discussed and results are quantified. |
1809.05526 | Yair Mulian | Edmond Iancu, Yair Mulian | Forward trijet production in proton-nucleus collisions | 63 pages, 31 figures | null | 10.1016/j.nuclphysa.2019.02.003 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Using the formalism of the light-cone wave function in perturbative QCD
together with the hybrid factorization, we compute the cross-section for three
particle production at forward rapidities in proton-nucleus collisions. We
focus on the quark channel, in which the three produced partons -- a quark
accompanied by a gluon pair, or two quarks plus one antiquark -- are all
generated via two successive splittings starting with a quark that was
originally collinear with the proton. The three partons are put on-shell by
their scattering off the nuclear target, described as a Lorentz-contracted
"shockwave". The three-parton component of the quark light-cone wave function
that we compute on this occasion is also an ingredient for other interesting
calculations, like the next-to-leading order correction to the cross-section
for the production of a pair of jets.
| [
{
"created": "Fri, 14 Sep 2018 17:57:21 GMT",
"version": "v1"
}
] | 2019-03-27 | [
[
"Iancu",
"Edmond",
""
],
[
"Mulian",
"Yair",
""
]
] | Using the formalism of the light-cone wave function in perturbative QCD together with the hybrid factorization, we compute the cross-section for three particle production at forward rapidities in proton-nucleus collisions. We focus on the quark channel, in which the three produced partons -- a quark accompanied by a gluon pair, or two quarks plus one antiquark -- are all generated via two successive splittings starting with a quark that was originally collinear with the proton. The three partons are put on-shell by their scattering off the nuclear target, described as a Lorentz-contracted "shockwave". The three-parton component of the quark light-cone wave function that we compute on this occasion is also an ingredient for other interesting calculations, like the next-to-leading order correction to the cross-section for the production of a pair of jets. |
hep-ph/9209264 | null | S. Y. Choi and H. S. Song | Exclusive heavy meson pair production by $\gamma\gamma$ collision in
heavy quark effective theory | 10pages (LaTex) (two figures, available on request), SNUTP 92-57 | Phys.Lett. B296 (1992) 420-424 | 10.1016/0370-2693(92)91342-7 | null | hep-ph | null | The spin and flavor symmetries of the heavy quark effective theory are
employed to discuss the exclusive cross sections for pair production of heavy
mesons in photon-photon collision. The ratios of the exclusive cross sections
for heavy mesons are obtained explicitly and the validity of results is
discussed.
| [
{
"created": "Tue, 22 Sep 1992 19:17:12 GMT",
"version": "v1"
}
] | 2009-10-22 | [
[
"Choi",
"S. Y.",
""
],
[
"Song",
"H. S.",
""
]
] | The spin and flavor symmetries of the heavy quark effective theory are employed to discuss the exclusive cross sections for pair production of heavy mesons in photon-photon collision. The ratios of the exclusive cross sections for heavy mesons are obtained explicitly and the validity of results is discussed. |
2205.07912 | Rahool Kumar Barman | Rahool Kumar Barman and Ahmed Ismail | Constraining the top electroweak sector of the SMEFT through $Z$
associated top pair and single top production at the HL-LHC | 19 pages, 9 figures, 8 tables | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We study the processes $pp \to t\bar{t}Z$ and $pp \to tZj$ in the framework
of Standard Model Effective Field Theory (SMEFT), employing conventional
cut-and-count as well as machine learning techniques to take advantage of
kinematic information in complex final states involving multiple leptons and
$b$ jets. We explore the projected sensitivity for two SMEFT operators,
$\mathcal{O}_{tZ}$ and $\mathcal{O}_{tW}$, that induce electroweak dipole
moment interactions for top quarks, through direct searches in these
electroweak top production processes at the HL-LHC. New physics modifications
to dominant backgrounds are also considered. We show that the new physics
sensitivity can be enhanced through a combination of differential distributions
for relevant kinematic observables and machine learning techniques. Searches in
$t\bar{t}Z$ and $tZj$ production result in stronger constraints on
$\mathcal{C}_{tZ}$ and $\mathcal{C}_{tW}$, respectively. At the HL-LHC,
$\mathcal{C}_{tZ}$ can be probed up to $-0.41 \lesssim \mathcal{C}_{tZ}
\lesssim 0.47$ through searches in the $pp \to t\bar{t}Z + tWZ \to 3\ell + 2b\
+ \geq 2j$ channel while $\mathcal{C}_{tW}$ can be probed up to $-0.14 \lesssim
\mathcal{C}_{tW} < 0.11$ from searches in the $pp \to tZj + t\bar{t}Z + tWZ \to
3\ell + 1b + 1/2j$ channel, at $95\%$ CL.
| [
{
"created": "Mon, 16 May 2022 18:01:06 GMT",
"version": "v1"
}
] | 2022-05-18 | [
[
"Barman",
"Rahool Kumar",
""
],
[
"Ismail",
"Ahmed",
""
]
] | We study the processes $pp \to t\bar{t}Z$ and $pp \to tZj$ in the framework of Standard Model Effective Field Theory (SMEFT), employing conventional cut-and-count as well as machine learning techniques to take advantage of kinematic information in complex final states involving multiple leptons and $b$ jets. We explore the projected sensitivity for two SMEFT operators, $\mathcal{O}_{tZ}$ and $\mathcal{O}_{tW}$, that induce electroweak dipole moment interactions for top quarks, through direct searches in these electroweak top production processes at the HL-LHC. New physics modifications to dominant backgrounds are also considered. We show that the new physics sensitivity can be enhanced through a combination of differential distributions for relevant kinematic observables and machine learning techniques. Searches in $t\bar{t}Z$ and $tZj$ production result in stronger constraints on $\mathcal{C}_{tZ}$ and $\mathcal{C}_{tW}$, respectively. At the HL-LHC, $\mathcal{C}_{tZ}$ can be probed up to $-0.41 \lesssim \mathcal{C}_{tZ} \lesssim 0.47$ through searches in the $pp \to t\bar{t}Z + tWZ \to 3\ell + 2b\ + \geq 2j$ channel while $\mathcal{C}_{tW}$ can be probed up to $-0.14 \lesssim \mathcal{C}_{tW} < 0.11$ from searches in the $pp \to tZj + t\bar{t}Z + tWZ \to 3\ell + 1b + 1/2j$ channel, at $95\%$ CL. |
1808.07470 | Fredrick Olness | Bo-Ting Wang, T. J. Hobbs, Sean Doyle, Jun Gao, Tie-Jiun Hou, Pavel M.
Nadolsky, Fredrick I. Olness | PDFSense: Mapping the sensitivity of hadronic experiments to nucleon
structure | 6 pages, 3 figures. arXiv admin note: substantial text overlap with
arXiv:1803.02777 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Recent high precision experimental data from a variety of hadronic processes
opens new opportunities for determination of the collinear parton distribution
functions (PDFs) of the proton. In fact, the wealth of information from
experiments such as the Large Hadron Collider (LHC) and others, makes it
difficult to quickly assess the impact on the PDFs, short of performing
computationally expensive global fits. As an alternative, we explore new
methods for quantifying the potential impact of experimental data on the
extraction of proton PDFs. Our approach relies crucially on the correlation
between theory-data residuals and the PDFs themselves, as well as on a newly
defined quantity --- the sensitivity --- which represents an extension of the
correlation and reflects both PDF-driven and experimental uncertainties. This
approach is realized in a new, publicly available analysis package PDFSense,
which operates with these statistical measures to identify particularly
sensitive experiments, weigh their relative or potential impact on PDFs, and
visualize their detailed distributions in a space of the parton momentum
fraction x and factorization scale \mu. This tool offers a new means of
understanding the influence of individual measurements in existing fits, as
well as a predictive device for directing future fits toward the highest impact
data and assumptions.
| [
{
"created": "Tue, 21 Aug 2018 20:12:42 GMT",
"version": "v1"
}
] | 2018-08-24 | [
[
"Wang",
"Bo-Ting",
""
],
[
"Hobbs",
"T. J.",
""
],
[
"Doyle",
"Sean",
""
],
[
"Gao",
"Jun",
""
],
[
"Hou",
"Tie-Jiun",
""
],
[
"Nadolsky",
"Pavel M.",
""
],
[
"Olness",
"Fredrick I.",
""
]
] | Recent high precision experimental data from a variety of hadronic processes opens new opportunities for determination of the collinear parton distribution functions (PDFs) of the proton. In fact, the wealth of information from experiments such as the Large Hadron Collider (LHC) and others, makes it difficult to quickly assess the impact on the PDFs, short of performing computationally expensive global fits. As an alternative, we explore new methods for quantifying the potential impact of experimental data on the extraction of proton PDFs. Our approach relies crucially on the correlation between theory-data residuals and the PDFs themselves, as well as on a newly defined quantity --- the sensitivity --- which represents an extension of the correlation and reflects both PDF-driven and experimental uncertainties. This approach is realized in a new, publicly available analysis package PDFSense, which operates with these statistical measures to identify particularly sensitive experiments, weigh their relative or potential impact on PDFs, and visualize their detailed distributions in a space of the parton momentum fraction x and factorization scale \mu. This tool offers a new means of understanding the influence of individual measurements in existing fits, as well as a predictive device for directing future fits toward the highest impact data and assumptions. |
hep-ph/9807332 | Michael Melles | Michael Melles, W. James Stirling | All-Orders Resummation of Leading Logarithmic Contributions to Heavy
Quark Production in Polarized \gamma \gamma Collisions | 30 pages, Latex2e with eps-figure format, submitted to Phys. Rev. D | Phys.Rev.D59:094009,1999 | 10.1103/PhysRevD.59.094009 | DTP/98/42 | hep-ph | null | The measurements of the $\gamma\gamma$ and $b \bar b$ partial decay widths of
an intermediate-mass Standard Model Higgs boson are among the most important
goals of a future photon linear collider. While in an initially polarized
$J_z=0$ state the background process $\gamma\gamma \to b \bar b$ is suppressed
by $\frac{m^2_b}{s}$, radiative corrections remove this suppression and are
known to be very sizable at theone-loop level. In particular a new type of
purely hard double logarithmic (DL) correction can even make the cross section
negative at this order in perturbation theory. The second order term of the
series is also known and enters with a positive sign at the two loop level.
From a theoretical as well as a practical point of view it is
clearlydesirable to resum this series and to know its high energy behavior.
In this paper, we derive the series of these novel ``non-Sudakov'' logarithms
to all orders and calculate the high energy limit analytically. We also give
explicit three loop corrections in the DL-approximation as a check of our
results and show that the three loop structure also reveals the higher order
behavior of mixed hard and soft double logarithms. We are thus able to resum
the virtual DL-corrections to $\gamma\gamma (J_z=0) \to b \bar b$ to all
orders.
| [
{
"created": "Fri, 10 Jul 1998 16:06:55 GMT",
"version": "v1"
}
] | 2011-01-25 | [
[
"Melles",
"Michael",
""
],
[
"Stirling",
"W. James",
""
]
] | The measurements of the $\gamma\gamma$ and $b \bar b$ partial decay widths of an intermediate-mass Standard Model Higgs boson are among the most important goals of a future photon linear collider. While in an initially polarized $J_z=0$ state the background process $\gamma\gamma \to b \bar b$ is suppressed by $\frac{m^2_b}{s}$, radiative corrections remove this suppression and are known to be very sizable at theone-loop level. In particular a new type of purely hard double logarithmic (DL) correction can even make the cross section negative at this order in perturbation theory. The second order term of the series is also known and enters with a positive sign at the two loop level. From a theoretical as well as a practical point of view it is clearlydesirable to resum this series and to know its high energy behavior. In this paper, we derive the series of these novel ``non-Sudakov'' logarithms to all orders and calculate the high energy limit analytically. We also give explicit three loop corrections in the DL-approximation as a check of our results and show that the three loop structure also reveals the higher order behavior of mixed hard and soft double logarithms. We are thus able to resum the virtual DL-corrections to $\gamma\gamma (J_z=0) \to b \bar b$ to all orders. |
1407.6703 | A. H. Rezaeian | N\'estor Armesto, Amir H. Rezaeian | Diffractive photoproduction of vector mesons at the LHC | 7 pages, 9 figures, to appear in proceedings of DIS 2014, XXII.
International Workshop on Deep-Inelastic Scattering and Related Subjects, 28
April - 2 May 2014, Warsaw, Poland | null | null | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We confront saturation-based results for diffractive $\psi(2s)$ and $\rho$
production at HERA and $J/\psi$ photoproduction with all available data
including recent ones from HERA, ALICE and LHCb, finding a good agreement. We
show that the $t$-distribution of differential cross-section of photoproduction
of vector mesons offers a unique opportunity to discriminate among saturation
and non-saturation models. This is due to emergence of a pronounced dip (or
multiple dips) in the $t$-distribution of diffractive photoproduction of vector
mesons at relatively large, but potentially accessible $|t|$ that can be traced
back to the unitarity features of colour dipole amplitude in the saturation
regime. We provide various predictions for exclusive (photo)-production of
different vector mesons including the ratio of $\psi(2s)/J/\psi$ at HERA, the
LHC and at future colliders.
| [
{
"created": "Thu, 24 Jul 2014 19:51:54 GMT",
"version": "v1"
}
] | 2014-07-25 | [
[
"Armesto",
"Néstor",
""
],
[
"Rezaeian",
"Amir H.",
""
]
] | We confront saturation-based results for diffractive $\psi(2s)$ and $\rho$ production at HERA and $J/\psi$ photoproduction with all available data including recent ones from HERA, ALICE and LHCb, finding a good agreement. We show that the $t$-distribution of differential cross-section of photoproduction of vector mesons offers a unique opportunity to discriminate among saturation and non-saturation models. This is due to emergence of a pronounced dip (or multiple dips) in the $t$-distribution of diffractive photoproduction of vector mesons at relatively large, but potentially accessible $|t|$ that can be traced back to the unitarity features of colour dipole amplitude in the saturation regime. We provide various predictions for exclusive (photo)-production of different vector mesons including the ratio of $\psi(2s)/J/\psi$ at HERA, the LHC and at future colliders. |
hep-ph/9403308 | Choong Sun Kim | C.S. Kim, Daesung Hwang, Pyungwon Ko and Wuk Namgung | Measuring $|V_{ub}|$ at future B-Factories | 9 pages (1 fugure not included) | Nucl.Phys.Proc.Suppl.37A:69-74,1994 | 10.1016/0920-5632(94)90736-6 | MAD/PH/817, YUMS 94-03, SNUTP 94-11 | hep-ph | null | We calculate the so--called Fermi motion parameter $p_{_F}$ of ACCMM model
using the variational method in a potential model approach. We also propose
hadronic invariant mass distribution as an alternative experimental observable
to measure $V_{ub}$ at future asymmetric $B$ factories.
| [
{
"created": "Fri, 18 Mar 1994 06:09:46 GMT",
"version": "v1"
}
] | 2015-06-25 | [
[
"Kim",
"C. S.",
""
],
[
"Hwang",
"Daesung",
""
],
[
"Ko",
"Pyungwon",
""
],
[
"Namgung",
"Wuk",
""
]
] | We calculate the so--called Fermi motion parameter $p_{_F}$ of ACCMM model using the variational method in a potential model approach. We also propose hadronic invariant mass distribution as an alternative experimental observable to measure $V_{ub}$ at future asymmetric $B$ factories. |
1403.6897 | Oleksandr Gituliar | Oleksandr Gituliar | Higher-Order Corrections in QCD Evolution Equations and Tools for Their
Calculation | PhD thesis | null | null | IFJPAN-IV-2014-4 | hep-ph | http://creativecommons.org/licenses/by-nc-sa/3.0/ | In this thesis we calculate the NLO one-loop virtual contributions to the QCD
DGLAP splitting functions in a form suitable for Monte Carlo simulations. We
use the standard technique based on the factorization properties of mass
singularities in the light-cone axial gauge \cite{EGMPR79,CFP80} but we propose
a modification to this approach by introducing a New Principal Value
prescription \cite{GJKS14} in which we use the PV prescription for
regularization of {\em all} singularities in the light-cone plus components of
the four-momenta. The main advantage of the NPV prescription is that exclusive
splitting functions calculated with its help can be used for construction of
the Monte-Carlo parton showers. The reason for this is that in the NPV
prescription some of the higher order poles in dimensional $\epsilon$ parameter
are replaced by the logarithms of a cut-off parameter $\delta$ which has a
geometrical meaning in four dimensions. As a consequence, cancellation of the
higher order poles between real and virtual components is reduced. On the other
hand, at the inclusive level the NPV results agree with the results in the
standard PV prescription which shows compatibility of both approaches.
With the help of the NPV prescription, we calculate virtual one-loop
contributions to the NLO non-singlet splitting function $P_{q\to q}^{NLO}$ and
selected contributions to the singlet $P_{g\to g}^{NLO}$ one. We also discuss
the dependence of the results on the choice of the integration variable related
to the evolution time in Monte Carlo parton showers. Finally, we present the
{\tt Axiloop} package written in Wolfram Mathematica language, that is
dedicated to perform NLO calculations in the axial gauge. Results presented in
this thesis were obtained with the help of the {\tt Axiloop} package.
| [
{
"created": "Thu, 27 Mar 2014 00:57:17 GMT",
"version": "v1"
},
{
"created": "Tue, 29 Apr 2014 13:21:59 GMT",
"version": "v2"
}
] | 2014-04-30 | [
[
"Gituliar",
"Oleksandr",
""
]
] | In this thesis we calculate the NLO one-loop virtual contributions to the QCD DGLAP splitting functions in a form suitable for Monte Carlo simulations. We use the standard technique based on the factorization properties of mass singularities in the light-cone axial gauge \cite{EGMPR79,CFP80} but we propose a modification to this approach by introducing a New Principal Value prescription \cite{GJKS14} in which we use the PV prescription for regularization of {\em all} singularities in the light-cone plus components of the four-momenta. The main advantage of the NPV prescription is that exclusive splitting functions calculated with its help can be used for construction of the Monte-Carlo parton showers. The reason for this is that in the NPV prescription some of the higher order poles in dimensional $\epsilon$ parameter are replaced by the logarithms of a cut-off parameter $\delta$ which has a geometrical meaning in four dimensions. As a consequence, cancellation of the higher order poles between real and virtual components is reduced. On the other hand, at the inclusive level the NPV results agree with the results in the standard PV prescription which shows compatibility of both approaches. With the help of the NPV prescription, we calculate virtual one-loop contributions to the NLO non-singlet splitting function $P_{q\to q}^{NLO}$ and selected contributions to the singlet $P_{g\to g}^{NLO}$ one. We also discuss the dependence of the results on the choice of the integration variable related to the evolution time in Monte Carlo parton showers. Finally, we present the {\tt Axiloop} package written in Wolfram Mathematica language, that is dedicated to perform NLO calculations in the axial gauge. Results presented in this thesis were obtained with the help of the {\tt Axiloop} package. |
2012.01537 | Gretel Quintero Angulo Dr. | G. Quintero Angulo, L. C. Su\'arez Gonz\'alez, A. P\'erez Mart\'inez
and H. P\'erez Rojas | Magnetized vector boson gas at any temperature | 26 pages, 7 figures | Phys. Rev. C 104, 035803 (2021) | 10.1103/PhysRevC.104.035803 | null | hep-ph astro-ph.HE cond-mat.quant-gas | http://creativecommons.org/licenses/by/4.0/ | We study the thermodynamic properties of a relativistic magnetized neutral
vector boson gas at any temperature. By comparing the results with the low
temperature and the non relativistic descriptions of this gas, we found that
the fully relativistic case can be separated in two regimes according to
temperature. For low temperatures, magnetic field effects dominate and the
system shows a spontaneous magnetization, its pressure splits in two components
and, eventually, a transversal magnetic collapse might occur. In the high
temperature region, the gas behavior is led by pair production. The presence of
antiparticles preserves the isotropy in the pressure, and increases the
magnetization and the total pressure of the system by several orders.
Astrophysical implications of those behaviors are discussed.
| [
{
"created": "Wed, 2 Dec 2020 21:22:29 GMT",
"version": "v1"
},
{
"created": "Tue, 19 Jan 2021 21:57:14 GMT",
"version": "v2"
},
{
"created": "Fri, 3 Sep 2021 21:12:29 GMT",
"version": "v3"
}
] | 2021-09-22 | [
[
"Angulo",
"G. Quintero",
""
],
[
"González",
"L. C. Suárez",
""
],
[
"Martínez",
"A. Pérez",
""
],
[
"Rojas",
"H. Pérez",
""
]
] | We study the thermodynamic properties of a relativistic magnetized neutral vector boson gas at any temperature. By comparing the results with the low temperature and the non relativistic descriptions of this gas, we found that the fully relativistic case can be separated in two regimes according to temperature. For low temperatures, magnetic field effects dominate and the system shows a spontaneous magnetization, its pressure splits in two components and, eventually, a transversal magnetic collapse might occur. In the high temperature region, the gas behavior is led by pair production. The presence of antiparticles preserves the isotropy in the pressure, and increases the magnetization and the total pressure of the system by several orders. Astrophysical implications of those behaviors are discussed. |
hep-ph/9610236 | prof. Shmuel Nussinov | Shmuel Nussinov | Comments on glueballinos (R0 particles) and R0 searches | LaTeX, 28 pages | Phys.Rev. D57 (1998) 7006-7018 | 10.1103/PhysRevD.57.7006 | TPI-MINN-96/18-T | hep-ph | null | We propose a search strategy for the light R0 (glueballino) particle
suggested by G.Farrar in connection with the light gluino scenario. The basic
idea is to moderate and stop the R0 particles and then observe their decay to
almost monochromatic pions - at an appropriate time delay relative to a primary
collision event, where a gluino jet, likely to fragment into the R0, was
produced. This technique is optimized at colliders and depends on qualitative
features of the R0 hadronic interactions which we discuss in detail.
| [
{
"created": "Thu, 3 Oct 1996 19:11:52 GMT",
"version": "v1"
},
{
"created": "Tue, 8 Oct 1996 23:23:37 GMT",
"version": "v2"
}
] | 2009-10-28 | [
[
"Nussinov",
"Shmuel",
""
]
] | We propose a search strategy for the light R0 (glueballino) particle suggested by G.Farrar in connection with the light gluino scenario. The basic idea is to moderate and stop the R0 particles and then observe their decay to almost monochromatic pions - at an appropriate time delay relative to a primary collision event, where a gluino jet, likely to fragment into the R0, was produced. This technique is optimized at colliders and depends on qualitative features of the R0 hadronic interactions which we discuss in detail. |
hep-ph/0204354 | Abdelhak Djouadi | Aseshkrishna Datta, Abdelhak Djouadi and Margarete Muhlleitner (LPMT
Montpellier) | Associated production of sfermions and gauginos at high-energy e+e-
colliders: the case of selectrons and electronic sneutrinos | 24 pages, latex, axodraw.sty, 6 figures | Eur.Phys.J.C25:539-551,2002 | 10.1007/s10052-002-1027-6 | PM/02-09 | hep-ph | null | We analyze the associated production at future high--energy $e^+e^-$
colliders, of first generation sleptons with neutralinos and charginos in the
modes $e^+ e^-$ and $e \gamma$, in the framework of the Minimal Supersymmetric
extension of the Standard Model. We show that the production rates, in
particular for associated production of right--handed selectrons and the
lightest neutralino which in general is the first accessible kinematically, can
be much larger than the corresponding ones for second and third generation
scalar leptons and for scalar quarks. With the high--luminosities expected at
these colliders, the detection of first generation sleptons with masses
significantly above the kinematical two--body threshold, $\sqrt{s}=
2m_{\tilde{l}}$, is thus possible in favourable regions of the parameter space.
| [
{
"created": "Tue, 30 Apr 2002 13:57:24 GMT",
"version": "v1"
}
] | 2009-01-07 | [
[
"Datta",
"Aseshkrishna",
"",
"LPMT\n Montpellier"
],
[
"Djouadi",
"Abdelhak",
"",
"LPMT\n Montpellier"
],
[
"Muhlleitner",
"Margarete",
"",
"LPMT\n Montpellier"
]
] | We analyze the associated production at future high--energy $e^+e^-$ colliders, of first generation sleptons with neutralinos and charginos in the modes $e^+ e^-$ and $e \gamma$, in the framework of the Minimal Supersymmetric extension of the Standard Model. We show that the production rates, in particular for associated production of right--handed selectrons and the lightest neutralino which in general is the first accessible kinematically, can be much larger than the corresponding ones for second and third generation scalar leptons and for scalar quarks. With the high--luminosities expected at these colliders, the detection of first generation sleptons with masses significantly above the kinematical two--body threshold, $\sqrt{s}= 2m_{\tilde{l}}$, is thus possible in favourable regions of the parameter space. |
1509.00146 | Yuki Kamiya | Yuki Kamiya, Tetsuo Hyodo | Structure of near-threshold quasi-bound states | 5 pages, no figure, v3: published version | Phys. Rev. C 93, 035203 (2016) | 10.1103/PhysRevC.93.035203 | null | hep-ph hep-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the compositeness of near-threshold quasi-bound states in the
framework of effective field theory. From the viewpoint of the low-energy
universality, we revisit the model-independent relations between the structure
of the bound state and the observables in the weak binding limit. The effective
field theory is utilized to generalize the weak-binding relation of the stable
bound states to unstable quasi-bound states with decay modes. We present the
interpretation of the complex values of the compositeness for the unstable
states. Combining the model-independent relation and the threshold observables
extracted from the experimental data, we show that Lambda(1405) is dominated by
the Kbar N molecular structure and that a_0(980) is dominated by the non-Kbar K
component.
| [
{
"created": "Tue, 1 Sep 2015 05:28:03 GMT",
"version": "v1"
},
{
"created": "Sun, 6 Sep 2015 07:49:50 GMT",
"version": "v2"
},
{
"created": "Sun, 22 May 2016 07:02:09 GMT",
"version": "v3"
}
] | 2016-05-24 | [
[
"Kamiya",
"Yuki",
""
],
[
"Hyodo",
"Tetsuo",
""
]
] | We study the compositeness of near-threshold quasi-bound states in the framework of effective field theory. From the viewpoint of the low-energy universality, we revisit the model-independent relations between the structure of the bound state and the observables in the weak binding limit. The effective field theory is utilized to generalize the weak-binding relation of the stable bound states to unstable quasi-bound states with decay modes. We present the interpretation of the complex values of the compositeness for the unstable states. Combining the model-independent relation and the threshold observables extracted from the experimental data, we show that Lambda(1405) is dominated by the Kbar N molecular structure and that a_0(980) is dominated by the non-Kbar K component. |
1805.01295 | A. A. Natale | D. A. Fagundes, E. G. S. Luna, A. A. Natale and M. Pelaez | Exclusive production of pions and the pion distribution amplitude | 9 pages, 5 figures, extended discussion, new references, version to
appear in J. Phys. G | null | null | null | hep-ph hep-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Considering, as a limit case, an approximately flat pion distribution
amplitude, which is determined from the hardest, in momentum space, solution of
the Bethe-Salpeter equation for the pion wave function, we compute the pion
transition form factor $F_{\pi\gamma\gamma^{*}}(Q^{2})$ and the pion form
factor $F_{\pi}(Q^2)$, taking into account the LO as well as NLO form of the
hard coefficient function entering the leading-twist factorization formula. We
also compute the exclusive photoproduction of pions pairs at high energies,
$\gamma \gamma \to \pi^{+}\pi^{-}$, where perturbative QCD can be used to
compute the hard scattering matrix elements. We verify that the existent data
for exclusive pion production can be reasonably described as a function of such
flat distribution amplitude.
| [
{
"created": "Wed, 2 May 2018 13:51:26 GMT",
"version": "v1"
},
{
"created": "Tue, 8 Oct 2019 15:39:33 GMT",
"version": "v2"
},
{
"created": "Mon, 20 Jan 2020 12:58:23 GMT",
"version": "v3"
}
] | 2020-01-22 | [
[
"Fagundes",
"D. A.",
""
],
[
"Luna",
"E. G. S.",
""
],
[
"Natale",
"A. A.",
""
],
[
"Pelaez",
"M.",
""
]
] | Considering, as a limit case, an approximately flat pion distribution amplitude, which is determined from the hardest, in momentum space, solution of the Bethe-Salpeter equation for the pion wave function, we compute the pion transition form factor $F_{\pi\gamma\gamma^{*}}(Q^{2})$ and the pion form factor $F_{\pi}(Q^2)$, taking into account the LO as well as NLO form of the hard coefficient function entering the leading-twist factorization formula. We also compute the exclusive photoproduction of pions pairs at high energies, $\gamma \gamma \to \pi^{+}\pi^{-}$, where perturbative QCD can be used to compute the hard scattering matrix elements. We verify that the existent data for exclusive pion production can be reasonably described as a function of such flat distribution amplitude. |
1805.07101 | Takaaki Nomura | Tatsuo Kobayashi, Takaaki Nomura, Hiroshi Okada | Predictive neutrino mass textures with origin of flavor symmetries | 23 pages, 3 figures, version accepted for publication in physical
review D | Phys. Rev. D 98, 055025 (2018) | 10.1103/PhysRevD.98.055025 | EPHOU-18-004, KIAS-P18042, APCTP Pre2018 - 011 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate origins of predictive one-zero neutrino mass textures in a
systematic way. Here we search Abelian continuous(discrete) global symmetries,
and non-Abelian discrete symmetries, and show how to realize these neutrino
masses. Then we propose a concrete model involving a dark matter candidate and
an extra gauge boson, and show their phenomenologies.
| [
{
"created": "Fri, 18 May 2018 08:54:35 GMT",
"version": "v1"
},
{
"created": "Wed, 5 Sep 2018 12:54:26 GMT",
"version": "v2"
}
] | 2018-09-26 | [
[
"Kobayashi",
"Tatsuo",
""
],
[
"Nomura",
"Takaaki",
""
],
[
"Okada",
"Hiroshi",
""
]
] | We investigate origins of predictive one-zero neutrino mass textures in a systematic way. Here we search Abelian continuous(discrete) global symmetries, and non-Abelian discrete symmetries, and show how to realize these neutrino masses. Then we propose a concrete model involving a dark matter candidate and an extra gauge boson, and show their phenomenologies. |
hep-ph/9902389 | Mauro Moretti | C. Broggini, I. Masina, M. Moretti | The relevance of the vertex bremsstrahlung photon detection in the
electron-neutrino (antineutrino) electron scattering experiments at low
energy | Plain Latex plus six postscript figures not included in the text | Phys.Lett. B452 (1999) 137-142 | 10.1016/S0370-2693(99)00250-6 | null | hep-ph | null | We discuss the size of the electron-antineutrino electron into
electron-antineutrino electron cross section reduction due to the rejection of
the events with a vertex bremsstrahlung photon above a certain energy in the
final state. In particular we analyze the effect in experiments designed to
detect the low energy electron-antineutrino and electron-neutrino from a
nuclear reactor and from the Sun. We find that such reduction has to be
considered in a relatively high statistic reactor experiment, while it is
negligible for pp and 7Be solar neutrino detection.
| [
{
"created": "Thu, 18 Feb 1999 14:19:18 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Broggini",
"C.",
""
],
[
"Masina",
"I.",
""
],
[
"Moretti",
"M.",
""
]
] | We discuss the size of the electron-antineutrino electron into electron-antineutrino electron cross section reduction due to the rejection of the events with a vertex bremsstrahlung photon above a certain energy in the final state. In particular we analyze the effect in experiments designed to detect the low energy electron-antineutrino and electron-neutrino from a nuclear reactor and from the Sun. We find that such reduction has to be considered in a relatively high statistic reactor experiment, while it is negligible for pp and 7Be solar neutrino detection. |
1604.05328 | Bakul Agarwal ` | Bakul Agarwal, Joshua Isaacson and Kirtimaan A. Mohan | Minimal Dilaton Model and the Diphoton Excess | 27 pages, 14 figures | Phys. Rev. D 94, 035027 (2016) | 10.1103/PhysRevD.94.035027 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In light of the recent 750 GeV diphoton excesses reported by the ATLAS and
CMS collaborations, we investigate the possibility of explaining this excess
using the Minimal Dilaton Model. We find that this model is able to explain the
observed excess with the presence of additional top partner(s), with same
charge as the top quark, but with mass in the TeV region. First, we constrain
model parameters using in addition to the 750 GeV diphoton signal strength,
precision electroweak tests, single top production measurements, as well as
Higgs signal strength data collected in the earlier runs of the LHC. In
addition we discuss interesting phenomenolgy that could arise in this model,
relevant for future runs of the LHC.
| [
{
"created": "Mon, 18 Apr 2016 20:00:27 GMT",
"version": "v1"
}
] | 2016-09-07 | [
[
"Agarwal",
"Bakul",
""
],
[
"Isaacson",
"Joshua",
""
],
[
"Mohan",
"Kirtimaan A.",
""
]
] | In light of the recent 750 GeV diphoton excesses reported by the ATLAS and CMS collaborations, we investigate the possibility of explaining this excess using the Minimal Dilaton Model. We find that this model is able to explain the observed excess with the presence of additional top partner(s), with same charge as the top quark, but with mass in the TeV region. First, we constrain model parameters using in addition to the 750 GeV diphoton signal strength, precision electroweak tests, single top production measurements, as well as Higgs signal strength data collected in the earlier runs of the LHC. In addition we discuss interesting phenomenolgy that could arise in this model, relevant for future runs of the LHC. |
hep-ph/0204280 | Helmut Eberl | H. Eberl, W. Majerotto, and V. C. Spanos | Radiative corrections to single Higgs boson production in $e^+ e^-$
annihilation | Version to appear in Phys. Lett. B | Phys.Lett. B538 (2002) 353-358 | 10.1016/S0370-2693(02)02031-2 | HEPHY-PUB 754/02 | hep-ph | null | For energies relevant to future linear colliders, $\sqrt{s} \gsim 500$ GeV,
the WW fusion channel dominates the Higgs boson production cross section $e^+
e^- \to \bar{\nu} \nu h^0$. We have calculated the one-loop corrections to this
process due to fermion and sfermion loops in the context of the MSSM. As a
special case, the contribution of the fermion loops in the SM has also been
studied. In general, the correction is negative and sizeable of the order of 10
percent, the bulk of it being due to fermion loops.
| [
{
"created": "Wed, 24 Apr 2002 12:45:49 GMT",
"version": "v1"
},
{
"created": "Tue, 30 Apr 2002 15:52:53 GMT",
"version": "v2"
},
{
"created": "Wed, 29 May 2002 15:32:32 GMT",
"version": "v3"
}
] | 2015-06-25 | [
[
"Eberl",
"H.",
""
],
[
"Majerotto",
"W.",
""
],
[
"Spanos",
"V. C.",
""
]
] | For energies relevant to future linear colliders, $\sqrt{s} \gsim 500$ GeV, the WW fusion channel dominates the Higgs boson production cross section $e^+ e^- \to \bar{\nu} \nu h^0$. We have calculated the one-loop corrections to this process due to fermion and sfermion loops in the context of the MSSM. As a special case, the contribution of the fermion loops in the SM has also been studied. In general, the correction is negative and sizeable of the order of 10 percent, the bulk of it being due to fermion loops. |
1412.8333 | Debasish Borah | Rupam Kalita, Debasish Borah and Mrinal Kumar Das | Corrections to Scaling Neutrino Mixing: Non-zero $\theta_{13},
\delta_{CP}$ and Baryon Asymmetry | 30 pages, 7 figures, to appear in Nucl. Phys. B | null | 10.1016/j.nuclphysb.2015.03.007 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study a very specific type of neutrino mass and mixing structure based on
the idea of Strong Scaling Ansatz (SSA) where the ratios of neutrino mass
matrix elements belonging to two different columns are equal. There are three
such possibilities, all of which are disfavored by the latest neutrino
oscillation data. We focus on the specific scenario which predicts vanishing
reactor mixing angle $\theta_{13}$ and inverted hierarchy with vanishing
lightest neutrino mass. Motivated by several recent attempts to explain
non-zero $\theta_{13}$ by incorporating corrections to a leading order neutrino
mass or mixing matrix giving $\theta_{13}=0$, here we study the origin of
non-zero $\theta_{13}$ as well as leptonic Dirac CP phase $\delta_{CP}$ by
incorporating two different corrections to scaling neutrino mass and mixing:
one where type II seesaw acts as a correction to scaling neutrino mass matrix
and the other with charged lepton correction to scaling neutrino mixing.
Although scaling neutrino mass matrix originating from type I seesaw predicts
inverted hierarchy, the total neutrino mass matrix after type II seesaw
correction can give rise to either normal or inverted hierarchy. However,
charged lepton corrections do not disturb the inverted hierarchy prediction of
scaling neutrino mass matrix. We further discriminate between neutrino
hierarchies, different choices of lightest neutrino mass and Dirac CP phase by
calculating baryon asymmetry and comparing with the observations made by the
Planck experiment.
| [
{
"created": "Mon, 29 Dec 2014 13:28:05 GMT",
"version": "v1"
},
{
"created": "Wed, 11 Mar 2015 17:58:15 GMT",
"version": "v2"
}
] | 2015-06-23 | [
[
"Kalita",
"Rupam",
""
],
[
"Borah",
"Debasish",
""
],
[
"Das",
"Mrinal Kumar",
""
]
] | We study a very specific type of neutrino mass and mixing structure based on the idea of Strong Scaling Ansatz (SSA) where the ratios of neutrino mass matrix elements belonging to two different columns are equal. There are three such possibilities, all of which are disfavored by the latest neutrino oscillation data. We focus on the specific scenario which predicts vanishing reactor mixing angle $\theta_{13}$ and inverted hierarchy with vanishing lightest neutrino mass. Motivated by several recent attempts to explain non-zero $\theta_{13}$ by incorporating corrections to a leading order neutrino mass or mixing matrix giving $\theta_{13}=0$, here we study the origin of non-zero $\theta_{13}$ as well as leptonic Dirac CP phase $\delta_{CP}$ by incorporating two different corrections to scaling neutrino mass and mixing: one where type II seesaw acts as a correction to scaling neutrino mass matrix and the other with charged lepton correction to scaling neutrino mixing. Although scaling neutrino mass matrix originating from type I seesaw predicts inverted hierarchy, the total neutrino mass matrix after type II seesaw correction can give rise to either normal or inverted hierarchy. However, charged lepton corrections do not disturb the inverted hierarchy prediction of scaling neutrino mass matrix. We further discriminate between neutrino hierarchies, different choices of lightest neutrino mass and Dirac CP phase by calculating baryon asymmetry and comparing with the observations made by the Planck experiment. |
1506.06386 | Jonathan Rosner | Marek Karliner and Jonathan L. Rosner | New Exotic Meson and Baryon Resonances from Doubly-Heavy Hadronic
Molecules | 8 pages, no figures, additional text and references, to be published
in Phys. Rev. Letters | Phys. Rev. Lett. 115, 122001 (2015) | 10.1103/PhysRevLett.115.122001 | EFI 15-20, TAUP 2997/15 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We predict several new exotic doubly-heavy hadronic resonances, inferring
from the observed exotic bottomonium-like and charmonium-like narrow states
$X(3872)$, $Z_b(10610)$, $Z_b(10650)$, $Z_c(3900)$, and $Z_c(4020/4025)$. We
interpret the binding mechanism as mostly molecular-like isospin-exchange
attraction between two heavy-light mesons in a relative S-wave state. We then
generalize it to other systems containing two heavy hadrons which can couple
through isospin exchange. The new predicted states include resonances in
meson-meson, meson-baryon, baryon-baryon, and baryon-antibaryon channels. These
include those giving rise to final states involving a heavy quark $Q=c,b$ and
antiquark $\bar Q' = \bar c,\bar b$, namely $D \bar D^*$, $D^* \bar D^*$, $D^*
B^*$, $\bar B B^*$, $\bar B^* B^*$, $\Sigma_c \bar D^*$, $\Sigma_c B^*$,
$\Sigma_b \bar D^*$, $\Sigma_b B^*$, $\Sigma_c \bar \Sigma_c$, $\Sigma_c \bar
\Lambda_c$, $\Sigma_c \bar \Lambda_b$, $\Sigma_b \bar \Sigma_b$, $\Sigma_b \bar
\Lambda_b$, and $\Sigma_b \bar \Lambda_c$, as well as corresponding S-wave
states giving rise to $Q Q'$ or $\bar Q \bar Q'$.
| [
{
"created": "Sun, 21 Jun 2015 16:32:53 GMT",
"version": "v1"
},
{
"created": "Fri, 26 Jun 2015 16:17:03 GMT",
"version": "v2"
},
{
"created": "Mon, 13 Jul 2015 18:55:56 GMT",
"version": "v3"
},
{
"created": "Mon, 24 Aug 2015 16:46:18 GMT",
"version": "v4"
}
] | 2015-09-23 | [
[
"Karliner",
"Marek",
""
],
[
"Rosner",
"Jonathan L.",
""
]
] | We predict several new exotic doubly-heavy hadronic resonances, inferring from the observed exotic bottomonium-like and charmonium-like narrow states $X(3872)$, $Z_b(10610)$, $Z_b(10650)$, $Z_c(3900)$, and $Z_c(4020/4025)$. We interpret the binding mechanism as mostly molecular-like isospin-exchange attraction between two heavy-light mesons in a relative S-wave state. We then generalize it to other systems containing two heavy hadrons which can couple through isospin exchange. The new predicted states include resonances in meson-meson, meson-baryon, baryon-baryon, and baryon-antibaryon channels. These include those giving rise to final states involving a heavy quark $Q=c,b$ and antiquark $\bar Q' = \bar c,\bar b$, namely $D \bar D^*$, $D^* \bar D^*$, $D^* B^*$, $\bar B B^*$, $\bar B^* B^*$, $\Sigma_c \bar D^*$, $\Sigma_c B^*$, $\Sigma_b \bar D^*$, $\Sigma_b B^*$, $\Sigma_c \bar \Sigma_c$, $\Sigma_c \bar \Lambda_c$, $\Sigma_c \bar \Lambda_b$, $\Sigma_b \bar \Sigma_b$, $\Sigma_b \bar \Lambda_b$, and $\Sigma_b \bar \Lambda_c$, as well as corresponding S-wave states giving rise to $Q Q'$ or $\bar Q \bar Q'$. |
2011.10959 | Zhi-Gang Wang | Zhi-Gang Wang | Analysis of the $Z_{cs}(3985)$ as the axialvector tetraquark state | 13 pages, 4 figures | Chin. Phys. C45 (2021) 073107 | 10.1088/1674-1137/abfa83 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | In this paper, we choose the scalar and axialvector diquark operators in the
color antitriplet as the fundamental building blocks to construct the
four-quark currents and investigate the diquark-antidiquark type axialvector
tetraquark states $c\bar{c}u\bar{s}$ in the framework of the QCD sum rules. The
predicted tetraquark mass $M_Z=3.99\pm0.09\,\rm{GeV}$ is in excellent agreement
with the experimental value $3985.2^{+2.1}_{-2.0}\pm1.7\,\rm{MeV}$ from the
BESIII collaboration, which supports identifying the $Z_{cs}(3985)$ as the
cousin of the $Z_c(3900)$ with the quantum numbers $J^{PC}=1^{+-}$. We take
into account the light flavor $SU(3)$ mass-breaking effect to estimate the mass
spectrum of the diquark-antidiquark type hidden-charm tetraquark states having
the strangeness according to the previous works.
| [
{
"created": "Sun, 22 Nov 2020 07:12:01 GMT",
"version": "v1"
},
{
"created": "Mon, 29 Mar 2021 13:48:02 GMT",
"version": "v2"
}
] | 2021-05-27 | [
[
"Wang",
"Zhi-Gang",
""
]
] | In this paper, we choose the scalar and axialvector diquark operators in the color antitriplet as the fundamental building blocks to construct the four-quark currents and investigate the diquark-antidiquark type axialvector tetraquark states $c\bar{c}u\bar{s}$ in the framework of the QCD sum rules. The predicted tetraquark mass $M_Z=3.99\pm0.09\,\rm{GeV}$ is in excellent agreement with the experimental value $3985.2^{+2.1}_{-2.0}\pm1.7\,\rm{MeV}$ from the BESIII collaboration, which supports identifying the $Z_{cs}(3985)$ as the cousin of the $Z_c(3900)$ with the quantum numbers $J^{PC}=1^{+-}$. We take into account the light flavor $SU(3)$ mass-breaking effect to estimate the mass spectrum of the diquark-antidiquark type hidden-charm tetraquark states having the strangeness according to the previous works. |
2008.12838 | Eric S. Swanson | T.J. Burns and E.S. Swanson | Kinematical Cusp and Resonance Interpretations of the $X(2900)$ | 10 pages, 3 figures. Version to appear in Physics Letters B | null | 10.1016/j.physletb.2020.136057 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We examine whether the LHCb vector $ud\bar{c}\bar{s}$ state $X(2900)$ can be
interpreted as a kinematical cusp effect arising from $\bar D^*K^*$ and $\bar
D_1 K^*$ interactions. The production amplitude is modelled as a triangle
diagram with hadronic final state interactions. A satisfactory fit to the
Dalitz plot projection is obtained that leverages the singularities of the
production diagram without the need for $\bar{D}K$ resonances. A somewhat
better fit is obtained if the final state interactions are strong enough to
generate resonances, although the evidence in favour of this scenario is not
conclusive.
| [
{
"created": "Fri, 28 Aug 2020 20:37:06 GMT",
"version": "v1"
},
{
"created": "Fri, 1 Jan 2021 23:14:54 GMT",
"version": "v2"
}
] | 2021-01-06 | [
[
"Burns",
"T. J.",
""
],
[
"Swanson",
"E. S.",
""
]
] | We examine whether the LHCb vector $ud\bar{c}\bar{s}$ state $X(2900)$ can be interpreted as a kinematical cusp effect arising from $\bar D^*K^*$ and $\bar D_1 K^*$ interactions. The production amplitude is modelled as a triangle diagram with hadronic final state interactions. A satisfactory fit to the Dalitz plot projection is obtained that leverages the singularities of the production diagram without the need for $\bar{D}K$ resonances. A somewhat better fit is obtained if the final state interactions are strong enough to generate resonances, although the evidence in favour of this scenario is not conclusive. |
2404.07842 | Filip Rescic | J. M. Carmona, J. L. Cort\'es, F. Rescic, M. A. Reyes, T. Terzi\'c, F.
I. Vrban | Approaches to photon absorption in a Lorentz invariance violation
scenario | 11 pages, 10 figures | null | null | null | hep-ph astro-ph.HE gr-qc | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We examine the Universe's transparency to gamma rays within a Lorentz
Invariance Violation (LIV) framework, focusing on photon subluminal quadratic
corrections driven by a high-energy scale. Based on an explicit calculation, we
provide a new expression for the cross section that overcomes the limitations
of previous approaches and refines existing constraints for the LIV scale,
while we introduce a new approximation that may be useful in LIV scenarios
beyond effective field theory. These improvements appear essential for setting
constraints on LIV effects with future observations at ultra-high energies,
where previous approximations may fall short.
| [
{
"created": "Thu, 11 Apr 2024 15:30:57 GMT",
"version": "v1"
}
] | 2024-04-12 | [
[
"Carmona",
"J. M.",
""
],
[
"Cortés",
"J. L.",
""
],
[
"Rescic",
"F.",
""
],
[
"Reyes",
"M. A.",
""
],
[
"Terzić",
"T.",
""
],
[
"Vrban",
"F. I.",
""
]
] | We examine the Universe's transparency to gamma rays within a Lorentz Invariance Violation (LIV) framework, focusing on photon subluminal quadratic corrections driven by a high-energy scale. Based on an explicit calculation, we provide a new expression for the cross section that overcomes the limitations of previous approaches and refines existing constraints for the LIV scale, while we introduce a new approximation that may be useful in LIV scenarios beyond effective field theory. These improvements appear essential for setting constraints on LIV effects with future observations at ultra-high energies, where previous approximations may fall short. |
0809.2788 | Joao Silva | P. M. Ferreira and Joao P. Silva | Discrete and continuous symmetries in multi-Higgs-doublet models | 13 pages, RevTex, references added | Phys.Rev.D78:116007,2008 | 10.1103/PhysRevD.78.116007 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider the Higgs sector of multi-Higgs-doublet models in the presence of
simple symmetries relating the various fields. We construct basis invariant
observables which may in principle be used to detect these symmetries for any
number of doublets. A categorization of the symmetries into classes is
required, which we perform in detail for the case of two and three Higgs
doublets.
| [
{
"created": "Tue, 16 Sep 2008 20:01:36 GMT",
"version": "v1"
},
{
"created": "Mon, 29 Sep 2008 18:26:19 GMT",
"version": "v2"
}
] | 2010-04-15 | [
[
"Ferreira",
"P. M.",
""
],
[
"Silva",
"Joao P.",
""
]
] | We consider the Higgs sector of multi-Higgs-doublet models in the presence of simple symmetries relating the various fields. We construct basis invariant observables which may in principle be used to detect these symmetries for any number of doublets. A categorization of the symmetries into classes is required, which we perform in detail for the case of two and three Higgs doublets. |
hep-ph/0411207 | Tomoi Koide | T. Koide | Phenomenological approach to the critical dynamics of the QCD phase
transition revisited | 13 pages, the Curie principle is discussed in S.2, to appear in
J.Phys.G | J.Phys. G31 (2005) 1055-1066 | 10.1088/0954-3899/31/9/008 | null | hep-ph cond-mat.stat-mech nucl-th | null | The phenomenological dynamics of the QCD critical phenomena is revisited.
Recently, Son and Stephanov claimed that the dynamical universality class of
the QCD phase transition belongs to model H. In their discussion, they employed
a time-dependent Ginzburg-Landau equation for the net baryon number density,
which is a conserved quantity. We derive the Langevin equation for the net
baryon number density, i.e., the Cahn-Hilliard equation. Furthermore, they
discussed the mode coupling induced through the {\it irreversible} current.
Here, we show the {\it reversible} coupling can play a dominant role for
describing the QCD critical dynamics and that the dynamical universality class
does not necessarily belong to model H.
| [
{
"created": "Tue, 16 Nov 2004 11:35:59 GMT",
"version": "v1"
},
{
"created": "Tue, 12 Jul 2005 15:32:50 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Koide",
"T.",
""
]
] | The phenomenological dynamics of the QCD critical phenomena is revisited. Recently, Son and Stephanov claimed that the dynamical universality class of the QCD phase transition belongs to model H. In their discussion, they employed a time-dependent Ginzburg-Landau equation for the net baryon number density, which is a conserved quantity. We derive the Langevin equation for the net baryon number density, i.e., the Cahn-Hilliard equation. Furthermore, they discussed the mode coupling induced through the {\it irreversible} current. Here, we show the {\it reversible} coupling can play a dominant role for describing the QCD critical dynamics and that the dynamical universality class does not necessarily belong to model H. |
hep-ph/0504244 | Christian Fischer | Christian S. Fischer and Daniel Zwanziger | Infrared Behaviour and Running Couplings in Interpolating Gauges in QCD | 8 pages, 2 figures; v2: minor changes, version published in PRD | Phys.Rev. D72 (2005) 054005 | 10.1103/PhysRevD.72.054005 | IPPP/05/05 DCPT/05/10 | hep-ph hep-lat hep-th | null | We consider the class of gauges that interpolates between Landau- and
Coulomb-gauge QCD, and show the non-renormalisation of the two independent
ghost-gluon vertices. This implies the existence of two RG-invariant running
couplings, one of which is interpreted as an RG-invariant gauge parameter. We
also present the asymptotic infrared limit of solutions of the Dyson-Schwinger
equations in interpolating gauges. The infrared critical exponents of these
solutions as well as the resulting infrared fixed point of one of the couplings
are independent of the gauge parameter. This coupling also has a fixed point in
the Coulomb gauge limit and constitutes a second invariant charge besides the
well known colour-Coulomb potential.
| [
{
"created": "Tue, 26 Apr 2005 15:50:46 GMT",
"version": "v1"
},
{
"created": "Mon, 22 Aug 2005 10:16:38 GMT",
"version": "v2"
}
] | 2009-11-11 | [
[
"Fischer",
"Christian S.",
""
],
[
"Zwanziger",
"Daniel",
""
]
] | We consider the class of gauges that interpolates between Landau- and Coulomb-gauge QCD, and show the non-renormalisation of the two independent ghost-gluon vertices. This implies the existence of two RG-invariant running couplings, one of which is interpreted as an RG-invariant gauge parameter. We also present the asymptotic infrared limit of solutions of the Dyson-Schwinger equations in interpolating gauges. The infrared critical exponents of these solutions as well as the resulting infrared fixed point of one of the couplings are independent of the gauge parameter. This coupling also has a fixed point in the Coulomb gauge limit and constitutes a second invariant charge besides the well known colour-Coulomb potential. |
hep-ph/9803282 | Sasaki Ken | Ken Sasaki | Spin Structure Function g_2(x,Q^2) and Twist-3 Operators in large-N_C
QCD | Corrected Ref.[15] | Phys.Rev.D58:094007,1998 | 10.1103/PhysRevD.58.094007 | YNU-HEPTh-98-101 | hep-ph | null | It is shown in the framework of the operator product expansion and the
renormalization group method that the twist-3 part of flavour nonsinglet spin
structure function g_2(x,Q^2) obeys a simple Dokshitzer-Gribov-
Lipatov-Altarelli-Parisi (DGLAP) equation in the large N_C limit even in the
case of massive quarks (N_C is the number of colours). There are four different
types of twist-3 operators which contribute to g_2, including
quark-mass-dependent operators and the ones proportional to the equation of
motion. They are not all independent but are constrained by one relation. A new
choice of the independent operator bases leads to a simple form of the
evolution equation for g_2 at large N_C.
| [
{
"created": "Mon, 9 Mar 1998 12:33:39 GMT",
"version": "v1"
},
{
"created": "Tue, 10 Mar 1998 08:45:19 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"Sasaki",
"Ken",
""
]
] | It is shown in the framework of the operator product expansion and the renormalization group method that the twist-3 part of flavour nonsinglet spin structure function g_2(x,Q^2) obeys a simple Dokshitzer-Gribov- Lipatov-Altarelli-Parisi (DGLAP) equation in the large N_C limit even in the case of massive quarks (N_C is the number of colours). There are four different types of twist-3 operators which contribute to g_2, including quark-mass-dependent operators and the ones proportional to the equation of motion. They are not all independent but are constrained by one relation. A new choice of the independent operator bases leads to a simple form of the evolution equation for g_2 at large N_C. |
1307.2393 | Andrey Kozhushko | Alexey Gulov, Andrey Kozhushko | Estimates for the Abelian $Z'$ Couplings from the LHC Data | revtex, 9 pages, 8 figures. Title and abstract rewritten, figures
added, mixing angle investigated (thanks for the hint from the anonymous
IJMPA referee). v3 coincides with the published version | Int. J. Mod. Phys. A 29, 1450001 (2014) | 10.1142/S0217751X14500018 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper, we investigate the Drell-Yan process with the intermediate
heavy $Z'$ boson. We use a general approach to the Abelian $Z'$ that utilizes
the renormalization-group relations between the $Z'$ couplings and allows to
reduce the number of unknown $Z'$ parameters significantly. In a newly proposed
strategy, we estimate the LHC-driven constraints for the $Z'$ couplings to
lepton and quark vector currents. To do this, we calculate the $Z'$-related
contribution in the narrow-width approximation and compare the obtained values
to the experimental data presented by the ATLAS and CMS collaborations. Our
method allows to estimate the values of $Z'$ couplings to the $u$ and $d$
quarks and to final-state leptons.
| [
{
"created": "Tue, 9 Jul 2013 10:28:39 GMT",
"version": "v1"
},
{
"created": "Sun, 28 Jul 2013 07:07:16 GMT",
"version": "v2"
},
{
"created": "Mon, 13 Jan 2014 18:47:26 GMT",
"version": "v3"
}
] | 2014-01-14 | [
[
"Gulov",
"Alexey",
""
],
[
"Kozhushko",
"Andrey",
""
]
] | In this paper, we investigate the Drell-Yan process with the intermediate heavy $Z'$ boson. We use a general approach to the Abelian $Z'$ that utilizes the renormalization-group relations between the $Z'$ couplings and allows to reduce the number of unknown $Z'$ parameters significantly. In a newly proposed strategy, we estimate the LHC-driven constraints for the $Z'$ couplings to lepton and quark vector currents. To do this, we calculate the $Z'$-related contribution in the narrow-width approximation and compare the obtained values to the experimental data presented by the ATLAS and CMS collaborations. Our method allows to estimate the values of $Z'$ couplings to the $u$ and $d$ quarks and to final-state leptons. |
2207.04126 | Kamel Khelifa-Kerfa | K. Khelifa-Kerfa, Y. Delenda, N. Ziani | Jet shapes in H/V boson + jet with $k_t$ clustering at hadron colliders | Presented at DIS2022: XXIX International Workshop on Deep-Inelastic
Scattering and Related Subjects, May 2 - 6, 2022, Santiago de Compostela,
Spain | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present analytical calculations of the distribution of non-global jet
shapes in Higgs/vector boson + jet production at hadron colliders. Within the
eikonal-limit framework and implementing various jet algorithms, we compute the
full distribution of the particular jet mass shape observable at 2-loops,
including the large single-logarithms known as non-global logs and clustering
logs. We compare our next-to-leading-log analytical resummation to parton
showers and, after matching and including non-perturbative effects, to
experimental data. A good agreement is shown for all comparisons.
| [
{
"created": "Fri, 8 Jul 2022 21:01:15 GMT",
"version": "v1"
}
] | 2022-07-12 | [
[
"Khelifa-Kerfa",
"K.",
""
],
[
"Delenda",
"Y.",
""
],
[
"Ziani",
"N.",
""
]
] | We present analytical calculations of the distribution of non-global jet shapes in Higgs/vector boson + jet production at hadron colliders. Within the eikonal-limit framework and implementing various jet algorithms, we compute the full distribution of the particular jet mass shape observable at 2-loops, including the large single-logarithms known as non-global logs and clustering logs. We compare our next-to-leading-log analytical resummation to parton showers and, after matching and including non-perturbative effects, to experimental data. A good agreement is shown for all comparisons. |
hep-ph/0506280 | Michael Andreas Schmidt | Manfred Lindner, Michael Ratz, Michael Andreas Schmidt | Renormalization Group Evolution of Dirac Neutrino Masses | 19 pages, 5 figures; error in eq. 8 corrected, references added | JHEP0509:081,2005 | 10.1088/1126-6708/2005/09/081 | TUM-HEP-589/05 | hep-ph | null | There are good reasons why neutrinos could be Majorana particles, but there
exist also a number of very good reasons why neutrinos could have Dirac masses.
The latter option deserves more attention and we derive therefore analytic
expressions describing the renormalization group evolution of mixing angles and
of the CP phase for Dirac neutrinos. Radiative corrections to leptonic mixings
are in this case enhanced compared to the quark mixings because the hierarchy
of neutrino masses is milder and because the mixing angles are larger. The
renormalization group effects are compared to the precision of current and
future neutrino experiments. We find that, in the MSSM framework, radiative
corrections of the mixing angles are for large \tan\beta comparable to the
precision of future experiments.
| [
{
"created": "Tue, 28 Jun 2005 09:46:29 GMT",
"version": "v1"
},
{
"created": "Fri, 30 Sep 2005 20:02:04 GMT",
"version": "v2"
}
] | 2009-11-11 | [
[
"Lindner",
"Manfred",
""
],
[
"Ratz",
"Michael",
""
],
[
"Schmidt",
"Michael Andreas",
""
]
] | There are good reasons why neutrinos could be Majorana particles, but there exist also a number of very good reasons why neutrinos could have Dirac masses. The latter option deserves more attention and we derive therefore analytic expressions describing the renormalization group evolution of mixing angles and of the CP phase for Dirac neutrinos. Radiative corrections to leptonic mixings are in this case enhanced compared to the quark mixings because the hierarchy of neutrino masses is milder and because the mixing angles are larger. The renormalization group effects are compared to the precision of current and future neutrino experiments. We find that, in the MSSM framework, radiative corrections of the mixing angles are for large \tan\beta comparable to the precision of future experiments. |
hep-ph/9701347 | Marc Flesch | W. Bernreuther, A. Brandenburg, and M. Flesch (RWTH Aachen) | QCD Corrections to Decay Distributions of Neutral Higgs Bosons with
(In)definite CP Parity | 32 pages, REVTeX, uses: psfig,amssym,aps,preprint 14 ps figures | Phys. Rev. D 56, 90 (1997) | 10.1103/PhysRevD.56.90 | PITHA 97/4 | hep-ph | null | We compute the order $\alpha_s$ QCD corrections to the density matrix for the
decay of a neutral Higgs boson $\phi$ with (in)definite CP parity into a quark
antiquark pair, respectively the QED corrections for the decay into a pair of
charged leptons. We classify and calculate single spin asymmetries and
spin-spin correlations which are generated by the scalar and pseudoscalar
Yukawa couplings. These spin effects can be traced in $\phi \to \tau^-\tau^+$
and, for heavy Higgs bosons, in $\phi \to t\bar{t}$. We also calculate
resulting correlations among the final states and estimate, for the respective
decay modes, the number of events needed to measure the Yukawa couplings with
these correlations at the 3 sigma level.
| [
{
"created": "Wed, 22 Jan 1997 12:46:43 GMT",
"version": "v1"
}
] | 2016-08-24 | [
[
"Bernreuther",
"W.",
"",
"RWTH Aachen"
],
[
"Brandenburg",
"A.",
"",
"RWTH Aachen"
],
[
"Flesch",
"M.",
"",
"RWTH Aachen"
]
] | We compute the order $\alpha_s$ QCD corrections to the density matrix for the decay of a neutral Higgs boson $\phi$ with (in)definite CP parity into a quark antiquark pair, respectively the QED corrections for the decay into a pair of charged leptons. We classify and calculate single spin asymmetries and spin-spin correlations which are generated by the scalar and pseudoscalar Yukawa couplings. These spin effects can be traced in $\phi \to \tau^-\tau^+$ and, for heavy Higgs bosons, in $\phi \to t\bar{t}$. We also calculate resulting correlations among the final states and estimate, for the respective decay modes, the number of events needed to measure the Yukawa couplings with these correlations at the 3 sigma level. |
2306.06854 | Lei Meng | Junjie Cao, Lei Meng, Yuanfang Yue | Electron and Muon Anomalous Magnetic Moment in the $\mathbb{Z}_3$-NMSSM | 38 pages, 4 figures, 6 tables | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | Inspired by the recent measurements of the muon and electron anomalous
magnetic moments, the rapid progress of the LHC search for supersymmetry, and
the significantly improved sensitivities of dark matter direct detection
experiments, we studied the supersymmetric contribution to the electron
\texorpdfstring{$g-2$}{}, $a_e^{\rm SUSY}$, in the Next-to-Minimal
Supersymmetric Standard Model with a discrete $\mathbb{Z}_3$ symmetry. We
concluded that $a_e^{\rm SUSY}$ was mainly correlated with $a_\mu^{\rm SUSY}$
by the formula $a_e^{\rm SUSY}/m_e^2 \simeq a_\mu^{\rm SUSY}/m_\mu^2$, and
significant violations of this correlation might occur only in rare cases. As a
result, $a_e^{\rm SUSY}$ was typically around $5 \times 10^{-14}$ when
$a_\mu^{\rm SUSY} \simeq 2.5 \times 10^{-9}$. We also concluded that the dark
matter direct detection and LHC experiments played crucial roles in determining
the maximum reach of $a_e^{\rm SUSY}$. Concretely, $a_e^{\rm SUSY}$ might be
around $3 \times 10^{-13}$ in the optimum cases if one used the XENON-1T
experiment to limit the supersymmetry parameter space. This prediction,
however, was reduced to $1.5 \times 10^{-13}$ after implementing the LZ
restrictions and $1.0 \times 10^{-13}$ when further considering the LHC
restrictions.
| [
{
"created": "Mon, 12 Jun 2023 04:01:42 GMT",
"version": "v1"
}
] | 2023-06-13 | [
[
"Cao",
"Junjie",
""
],
[
"Meng",
"Lei",
""
],
[
"Yue",
"Yuanfang",
""
]
] | Inspired by the recent measurements of the muon and electron anomalous magnetic moments, the rapid progress of the LHC search for supersymmetry, and the significantly improved sensitivities of dark matter direct detection experiments, we studied the supersymmetric contribution to the electron \texorpdfstring{$g-2$}{}, $a_e^{\rm SUSY}$, in the Next-to-Minimal Supersymmetric Standard Model with a discrete $\mathbb{Z}_3$ symmetry. We concluded that $a_e^{\rm SUSY}$ was mainly correlated with $a_\mu^{\rm SUSY}$ by the formula $a_e^{\rm SUSY}/m_e^2 \simeq a_\mu^{\rm SUSY}/m_\mu^2$, and significant violations of this correlation might occur only in rare cases. As a result, $a_e^{\rm SUSY}$ was typically around $5 \times 10^{-14}$ when $a_\mu^{\rm SUSY} \simeq 2.5 \times 10^{-9}$. We also concluded that the dark matter direct detection and LHC experiments played crucial roles in determining the maximum reach of $a_e^{\rm SUSY}$. Concretely, $a_e^{\rm SUSY}$ might be around $3 \times 10^{-13}$ in the optimum cases if one used the XENON-1T experiment to limit the supersymmetry parameter space. This prediction, however, was reduced to $1.5 \times 10^{-13}$ after implementing the LZ restrictions and $1.0 \times 10^{-13}$ when further considering the LHC restrictions. |
1607.06812 | Saul Ramos-Sanchez | Brenda Carballo-Perez, Eduardo Peinado, Saul Ramos-Sanchez | Delta(54) flavor phenomenology and strings | 21 pages, 2 figures; v2: fig. and appendix added, matches the version
published in JHEP | null | 10.1007/JHEP12(2016)131 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Delta(54) can serve as a flavor symmetry in particle physics, but remains
almost unexplored. We show that in a classification of semi-realistic Z3xZ3
heterotic string orbifolds, Delta(54) turns out to be the most natural flavor
symmetry, providing additional motivation for its study. We revisit its
phenomenological potential from a low-energy perspective and subject to the
constraints of string models. We find a model with Delta(54) arising from
heterotic orbifolds that leads to the Gatto-Sartori-Tonin relation for quarks
and charged-leptons. Additionally, in the neutrino sector, it leads to a normal
hierarchy for neutrino masses and a correlation between the reactor and the
atmospheric mixing angles, the latter taking values in the second octant and
being compatible at three sigmas with experimental data.
| [
{
"created": "Fri, 22 Jul 2016 20:00:01 GMT",
"version": "v1"
},
{
"created": "Fri, 23 Dec 2016 04:33:44 GMT",
"version": "v2"
}
] | 2017-02-01 | [
[
"Carballo-Perez",
"Brenda",
""
],
[
"Peinado",
"Eduardo",
""
],
[
"Ramos-Sanchez",
"Saul",
""
]
] | Delta(54) can serve as a flavor symmetry in particle physics, but remains almost unexplored. We show that in a classification of semi-realistic Z3xZ3 heterotic string orbifolds, Delta(54) turns out to be the most natural flavor symmetry, providing additional motivation for its study. We revisit its phenomenological potential from a low-energy perspective and subject to the constraints of string models. We find a model with Delta(54) arising from heterotic orbifolds that leads to the Gatto-Sartori-Tonin relation for quarks and charged-leptons. Additionally, in the neutrino sector, it leads to a normal hierarchy for neutrino masses and a correlation between the reactor and the atmospheric mixing angles, the latter taking values in the second octant and being compatible at three sigmas with experimental data. |
hep-ph/9504240 | Lahanas Athanasios | A. B. Lahanas | Static Quantities of the W bosons in the MSSM | 14 pages+2 figures , Latex, uses revtex[aps,aipbook,floats,epsfig]
(The two figures in a separate uuencode file ). Talk given at the
International Symposium on Gauge Boson self-interactions, UCLA, February 1-3,
1995 Los Angeles | null | 10.1063/1.49297 | null | hep-ph | null | I discuss the static quantities of the W boson, magnetic dipole and electric
quadrupole moments, in the context of the minimal supersymmetric standard
model, in which supersymmetry is broken by soft terms $A_o,\, m_o,\, M_{1/2}$.
Following a renormalization group analysis it is found that the supersymmetric
values of $\Delta k_{\gamma}$ and $\Delta Q_{\gamma}$ can be largely different,
in some cases, from the standard model predictions but of the same order of
magnitude for values of \quad $A_0,m_0,M_{1/2} \leq {\cal O}(1 TeV) $.
Therefore possible supersymmetric structure can be probed provided the accuracy
of measurements for $\Delta k_{\gamma}$, $\Delta Q_{\gamma}$ reaches
$10^{-2}-10^{-3}$ and hence hard to be detected at LEP2. In cases where
$M_{1/2} \ll A_0,m_0 $, the charginos and neutralinos may give substantial
contributions saturating the LEP2 sensitivity limits. This occurs when their
masses $m_{\tilde C},m_{\tilde Z}$ turn out to be both light satisfying
$m_{\tilde C}+m_{\tilde Z} \simeq M_W $. However these extreme cases are
perturbatively untrustworthy and besides unnatural for they occupy a small
region in the parameter space.
| [
{
"created": "Thu, 6 Apr 1995 08:04:46 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Lahanas",
"A. B.",
""
]
] | I discuss the static quantities of the W boson, magnetic dipole and electric quadrupole moments, in the context of the minimal supersymmetric standard model, in which supersymmetry is broken by soft terms $A_o,\, m_o,\, M_{1/2}$. Following a renormalization group analysis it is found that the supersymmetric values of $\Delta k_{\gamma}$ and $\Delta Q_{\gamma}$ can be largely different, in some cases, from the standard model predictions but of the same order of magnitude for values of \quad $A_0,m_0,M_{1/2} \leq {\cal O}(1 TeV) $. Therefore possible supersymmetric structure can be probed provided the accuracy of measurements for $\Delta k_{\gamma}$, $\Delta Q_{\gamma}$ reaches $10^{-2}-10^{-3}$ and hence hard to be detected at LEP2. In cases where $M_{1/2} \ll A_0,m_0 $, the charginos and neutralinos may give substantial contributions saturating the LEP2 sensitivity limits. This occurs when their masses $m_{\tilde C},m_{\tilde Z}$ turn out to be both light satisfying $m_{\tilde C}+m_{\tilde Z} \simeq M_W $. However these extreme cases are perturbatively untrustworthy and besides unnatural for they occupy a small region in the parameter space. |
hep-ph/0310118 | Michael Trusov A. | I.M.Narodetskii, Yu.A.Simonov, M.A.Trusov, A.I.Veselov | Pentaquark spectrum in string dynamics | 6 pages, 1 figure included, LaTeX2e; several references added;
misprints corrected; to appear in Physics Letters B | Phys.Lett. B578 (2004) 318-322 | 10.1016/j.physletb.2003.11.010 | null | hep-ph | null | The masses of $uudd\bar s $ and $uudd\bar d$ pentaquarks are evaluated in a
framework of the Effective Hamiltonian approach to QCD using the Jaffe-Wilczek
$[ud]^2\bar q$ approximation. The mass of the $[ud]^2\bar s$ state is found to
be $\sim 300-500$ MeV higher than the observed $\Theta^+(1540)$ mass.
| [
{
"created": "Thu, 9 Oct 2003 17:05:07 GMT",
"version": "v1"
},
{
"created": "Wed, 15 Oct 2003 14:39:43 GMT",
"version": "v2"
},
{
"created": "Mon, 1 Dec 2003 15:57:41 GMT",
"version": "v3"
}
] | 2015-06-25 | [
[
"Narodetskii",
"I. M.",
""
],
[
"Simonov",
"Yu. A.",
""
],
[
"Trusov",
"M. A.",
""
],
[
"Veselov",
"A. I.",
""
]
] | The masses of $uudd\bar s $ and $uudd\bar d$ pentaquarks are evaluated in a framework of the Effective Hamiltonian approach to QCD using the Jaffe-Wilczek $[ud]^2\bar q$ approximation. The mass of the $[ud]^2\bar s$ state is found to be $\sim 300-500$ MeV higher than the observed $\Theta^+(1540)$ mass. |
hep-ph/9406276 | Stephen Man Hoe Wong | S. Peign\'e and S.M.H. Wong | Non-Debye Screening in Finite Temperature QCD | LPTHE-Orsay 94/46.12 pages (latex), (Due to the appearance of more
recent related works, we changed our conclusion somewhat.) | Phys.Lett. B346 (1995) 322-328 | 10.1016/0370-2693(95)00020-L | null | hep-ph | null | We study the non-abelian, gauge invariant, screening potential between two
charges in a quark-gluon plasma. Using Braaten and Pisarski resummed
perturbation theory in temporal axial gauge, we find a repulsive power screened
potential which behaves as $\sim 1/r^6$ at large distance. This questions
either the physical meaning of the Debye mass or the known pragmatic treatment
of the temporal axial gauge propagator.
| [
{
"created": "Fri, 10 Jun 1994 14:11:38 GMT",
"version": "v1"
},
{
"created": "Mon, 13 Jun 1994 21:42:58 GMT",
"version": "v2"
},
{
"created": "Tue, 14 Jun 1994 14:01:50 GMT",
"version": "v3"
},
{
"created": "Mon, 21 Nov 1994 19:52:49 GMT",
"version": "v4"
}
] | 2009-10-28 | [
[
"Peigné",
"S.",
""
],
[
"Wong",
"S. M. H.",
""
]
] | We study the non-abelian, gauge invariant, screening potential between two charges in a quark-gluon plasma. Using Braaten and Pisarski resummed perturbation theory in temporal axial gauge, we find a repulsive power screened potential which behaves as $\sim 1/r^6$ at large distance. This questions either the physical meaning of the Debye mass or the known pragmatic treatment of the temporal axial gauge propagator. |
hep-ph/0212068 | Georg Weiglein | Ayres Freitas, Sven Heinemeyer and Georg Weiglein | Two-Loop Results for M_W in the Standard Model and the MSSM | 6 pages, Proceedings contribution to RADCOR 2002 - Loops & Legs 2002,
Kloster Banz, Germany, Sept. 2002 | Nucl.Phys.Proc.Suppl.116:331-335,2003 | 10.1016/S0920-5632(03)80194-9 | DCPT/02/150, IPPP/02/75, FERMILAB-Conf-02/312-T, LMU 14/02 | hep-ph | null | Recent higher-order results for the prediction of the W-boson mass, M_W,
within the Standard Model are reviewed and an estimate of the remaining
theoretical uncertainties of the electroweak precision observables is given. An
updated version of a simple numerical parameterisation of the result for M_W is
presented. Furthermore, leading electroweak two-loop contributions to the
precision observables within the MSSM are discussed.
| [
{
"created": "Wed, 4 Dec 2002 18:22:54 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Freitas",
"Ayres",
""
],
[
"Heinemeyer",
"Sven",
""
],
[
"Weiglein",
"Georg",
""
]
] | Recent higher-order results for the prediction of the W-boson mass, M_W, within the Standard Model are reviewed and an estimate of the remaining theoretical uncertainties of the electroweak precision observables is given. An updated version of a simple numerical parameterisation of the result for M_W is presented. Furthermore, leading electroweak two-loop contributions to the precision observables within the MSSM are discussed. |
1209.5859 | Rui-Lin Zhu | Cong-Feng Qiao, Peng Sun, Deshan Yang and Rui-Lin Zhu | $B_c$ Exclusive Decays to Charmonium and a Light Meson at
Next-to-Leading Order Accuracy | 20 pages, 7 figures and 5 tables | Phys. Rev. D 89, 034008 (2014) | 10.1103/PhysRevD.89.034008 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper the next-to-leading order (NLO) corrections to $B_c$ meson
exclusive decays to S-wave charmonia and light pseudoscalar or vector mesons,
i.e. $\pi$, $K$, $\rho$, and $K^*$, are performed within non-relativistic (NR)
QCD approach. The non-factorizable contribution is included, which is absent in
traditional naive factorization (NF). And the theoretical uncertainties for
their branching ratios are reduced compared with that of direct tree level
calculation. Numerical results show that NLO QCD corrections markedly enhance
the branching ratio with a K factor of 1.75 for $B_{c}^{\pm}\to \eta_{c}
\pi^{\pm}$ and 1.31 for $B_{c}^{\pm}\to J/\psi \pi^{\pm}$. In order to
investigate the asymptotic behavior, the analytic form is obtained in the heavy
quark limit, i.e. $m_b \to \infty$. We note that annihilation topologies
contribute trivia in this limit, and the corrections at leading order in $z=
m_c/m_b$ expansion come from form factors and hard spectator interactions. At
last, some related phenomenologies are also discussed.
| [
{
"created": "Wed, 26 Sep 2012 08:05:50 GMT",
"version": "v1"
},
{
"created": "Mon, 2 Dec 2013 20:15:04 GMT",
"version": "v2"
}
] | 2014-02-12 | [
[
"Qiao",
"Cong-Feng",
""
],
[
"Sun",
"Peng",
""
],
[
"Yang",
"Deshan",
""
],
[
"Zhu",
"Rui-Lin",
""
]
] | In this paper the next-to-leading order (NLO) corrections to $B_c$ meson exclusive decays to S-wave charmonia and light pseudoscalar or vector mesons, i.e. $\pi$, $K$, $\rho$, and $K^*$, are performed within non-relativistic (NR) QCD approach. The non-factorizable contribution is included, which is absent in traditional naive factorization (NF). And the theoretical uncertainties for their branching ratios are reduced compared with that of direct tree level calculation. Numerical results show that NLO QCD corrections markedly enhance the branching ratio with a K factor of 1.75 for $B_{c}^{\pm}\to \eta_{c} \pi^{\pm}$ and 1.31 for $B_{c}^{\pm}\to J/\psi \pi^{\pm}$. In order to investigate the asymptotic behavior, the analytic form is obtained in the heavy quark limit, i.e. $m_b \to \infty$. We note that annihilation topologies contribute trivia in this limit, and the corrections at leading order in $z= m_c/m_b$ expansion come from form factors and hard spectator interactions. At last, some related phenomenologies are also discussed. |
1002.4718 | Juan Antonio Aguilar-Saavedra | J. A. Aguilar-Saavedra, A. Onofre | Using single top rapidity to measure V_td, V_ts, V_tb at hadron
colliders | LaTeX 19 pages, 48 PS figures. A section added with estimations of
systematics, LO/NLO comparison and a fast detector simulation. Final version
to appear in PRD | Phys.Rev.D83:073003,2011 | 10.1103/PhysRevD.83.073003 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Single top production processes are usually regarded as the ones in which
V_tb can be directly measured at hadron colliders. We show that the analysis of
the single top rapidity distribution in t-channel and tW production can also
set direct limits on V_td. At LHC with 10 fb^-1 at 14 TeV the combined limits
on V_td may be reduced by almost a factor of two when the top rapidity
distribution is used. This also implies that the limits on V_tb can also be
reduced by 15%, since both parameters as well as V_ts must be simultaneously
obtained from a global fit to data. At Tevatron the explotation of this
distribution would require very high statistics.
| [
{
"created": "Thu, 25 Feb 2010 12:14:11 GMT",
"version": "v1"
},
{
"created": "Tue, 8 Mar 2011 08:51:10 GMT",
"version": "v2"
}
] | 2011-04-22 | [
[
"Aguilar-Saavedra",
"J. A.",
""
],
[
"Onofre",
"A.",
""
]
] | Single top production processes are usually regarded as the ones in which V_tb can be directly measured at hadron colliders. We show that the analysis of the single top rapidity distribution in t-channel and tW production can also set direct limits on V_td. At LHC with 10 fb^-1 at 14 TeV the combined limits on V_td may be reduced by almost a factor of two when the top rapidity distribution is used. This also implies that the limits on V_tb can also be reduced by 15%, since both parameters as well as V_ts must be simultaneously obtained from a global fit to data. At Tevatron the explotation of this distribution would require very high statistics. |
2110.12240 | Jorge Alda | Jorge Alda, Jaume Guasch, Siannah Penaranda | Exploring B-physics anomalies at colliders | 4 pages, 2 figures; contribution to the proceedings of the EPS-HEP
2021 conference | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Several experimental measurements of $B$ meson decays, in tension with
Standard Model predictions, exhibit large sources of Lepton Flavour
Universality violation. We perform an analysis of the effects of the global
fits to the Wilson coefficients assuming a model independent effective
Hamiltonian approach, by including a proposal of different scenarios to include
the New Physics contributions. Both the current fits at the LHC and the ILC
projections are considered. We found that for a simultaneous analysis of
predictions for the $R_{D^{(*)}}$ and $R_{K^{(*)}}$ observables, the scenarios
with three non-universal Wilson coefficients are favoured.
| [
{
"created": "Sat, 23 Oct 2021 15:20:17 GMT",
"version": "v1"
}
] | 2021-10-26 | [
[
"Alda",
"Jorge",
""
],
[
"Guasch",
"Jaume",
""
],
[
"Penaranda",
"Siannah",
""
]
] | Several experimental measurements of $B$ meson decays, in tension with Standard Model predictions, exhibit large sources of Lepton Flavour Universality violation. We perform an analysis of the effects of the global fits to the Wilson coefficients assuming a model independent effective Hamiltonian approach, by including a proposal of different scenarios to include the New Physics contributions. Both the current fits at the LHC and the ILC projections are considered. We found that for a simultaneous analysis of predictions for the $R_{D^{(*)}}$ and $R_{K^{(*)}}$ observables, the scenarios with three non-universal Wilson coefficients are favoured. |
hep-ph/0208257 | Adam Ritz | D.A. Demir, M. Pospelov, A. Ritz | Hadronic EDMs, the Weinberg Operator, and Light Gluinos | 6 pages, RevTeX, 3 figures; v2: references added; v3: typos
corrected, to appear in Phys. Rev. D | Phys.Rev. D67 (2003) 015007 | 10.1103/PhysRevD.67.015007 | null | hep-ph | null | We re-examine questions concerning the contribution of the three-gluon
Weinberg operator to the electric dipole moment of the neutron, and provide
several QCD sum rule-based arguments that the result is smaller than - but
nevertheless consistent with - estimates which invoke naive dimensional
analysis. We also point out a regime of the MSSM parameter space with light
gluinos for which this operator provides the dominant contribution to the
neutron electric dipole moment due to enhancement via the dimension five color
electric dipole moment of the gluino.
| [
{
"created": "Wed, 28 Aug 2002 15:04:56 GMT",
"version": "v1"
},
{
"created": "Fri, 30 Aug 2002 16:11:48 GMT",
"version": "v2"
},
{
"created": "Wed, 8 Jan 2003 11:46:20 GMT",
"version": "v3"
}
] | 2009-11-07 | [
[
"Demir",
"D. A.",
""
],
[
"Pospelov",
"M.",
""
],
[
"Ritz",
"A.",
""
]
] | We re-examine questions concerning the contribution of the three-gluon Weinberg operator to the electric dipole moment of the neutron, and provide several QCD sum rule-based arguments that the result is smaller than - but nevertheless consistent with - estimates which invoke naive dimensional analysis. We also point out a regime of the MSSM parameter space with light gluinos for which this operator provides the dominant contribution to the neutron electric dipole moment due to enhancement via the dimension five color electric dipole moment of the gluino. |
1801.07928 | Avik Paul | Avik Paul, Debasish Majumdar, Kamakshya Prasad Modak | Neutron Star Cooling via Axion Emission by Nucleon-Nucleon Axion
Bremsstrahlung | 17 pages, 10 Figures, minor changes | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Neutron stars generally cools off by the emission of gamma rays and
neutrinos. But axions can also be produced inside a neutron star by the process
of nucleon-nucleon axion bremsstrahlung. The escape of these axions adds to the
cooling process of neutron star. We explore the nature of cooling of neutron
stars including the axion emission and compare our result with the scenario
when the neutron star is cooled by only the emission of gamma rays and
neutrinos. In our calculations we consider both the degenerate and
non-degenerate limits for such axion energy loss rate and the resulting
variation of luminosity with time and variation of surface temperature with
time of the neutron star. In short the thermal evolution of a neutron star is
studied with three neutron star masses (1.0, 1.4, 1.8 solar masses) and by
including the effect of axion emission for different axion masses
($m_{a}=10^{-5}\rm{eV}, 10^{-3}\rm{eV}, 10^{-2}\rm{eV}$) and compared with the
same when the axion emission is not considered. We compared theoretical cooling
curve with the observational data of three pulsars PSR B056+14, Geminga and PSR
B1055-52 and finally give an upper bound on axion mass limits
$m_{a}\leq10^{-3}$ eV which implies that the axion decay constant
$f_{a}\geq0.6\times10^{10}\hspace{1mm}\rm{GeV}$.
| [
{
"created": "Wed, 24 Jan 2018 11:13:18 GMT",
"version": "v1"
},
{
"created": "Tue, 30 Jan 2018 08:49:24 GMT",
"version": "v2"
},
{
"created": "Thu, 7 Feb 2019 13:22:03 GMT",
"version": "v3"
}
] | 2019-02-08 | [
[
"Paul",
"Avik",
""
],
[
"Majumdar",
"Debasish",
""
],
[
"Modak",
"Kamakshya Prasad",
""
]
] | Neutron stars generally cools off by the emission of gamma rays and neutrinos. But axions can also be produced inside a neutron star by the process of nucleon-nucleon axion bremsstrahlung. The escape of these axions adds to the cooling process of neutron star. We explore the nature of cooling of neutron stars including the axion emission and compare our result with the scenario when the neutron star is cooled by only the emission of gamma rays and neutrinos. In our calculations we consider both the degenerate and non-degenerate limits for such axion energy loss rate and the resulting variation of luminosity with time and variation of surface temperature with time of the neutron star. In short the thermal evolution of a neutron star is studied with three neutron star masses (1.0, 1.4, 1.8 solar masses) and by including the effect of axion emission for different axion masses ($m_{a}=10^{-5}\rm{eV}, 10^{-3}\rm{eV}, 10^{-2}\rm{eV}$) and compared with the same when the axion emission is not considered. We compared theoretical cooling curve with the observational data of three pulsars PSR B056+14, Geminga and PSR B1055-52 and finally give an upper bound on axion mass limits $m_{a}\leq10^{-3}$ eV which implies that the axion decay constant $f_{a}\geq0.6\times10^{10}\hspace{1mm}\rm{GeV}$. |
1004.1555 | Wayne de Paula | W. de Paula and T. Frederico | Mesonic Spectrum from a Dynamical Gravity/Gauge model | Talk given at Light Cone 2009: Relativistic Hadronic and Particle
Physics (LC 2009), Sao Jose dos Campos, Brazil, 8-13 Jul 2009. | null | 10.1016/j.nuclphysbps.2010.02.014 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Within a formulation of a Dynamical AdS/QCD model we calculate the spectrum
of light flavored mesons. The background fields of the model correspond to an
IR deformed Anti de Sitter metric coupled to a dilaton field. Confinement comes
as a consequence of the dilaton dynamics coupled to gravity. Additionally to
the Regge-like spectrum of light- scalar, vector and higher spin mesons, we
obtain the decay width of scalar mesons into two pions.
| [
{
"created": "Fri, 9 Apr 2010 13:46:51 GMT",
"version": "v1"
}
] | 2015-05-18 | [
[
"de Paula",
"W.",
""
],
[
"Frederico",
"T.",
""
]
] | Within a formulation of a Dynamical AdS/QCD model we calculate the spectrum of light flavored mesons. The background fields of the model correspond to an IR deformed Anti de Sitter metric coupled to a dilaton field. Confinement comes as a consequence of the dilaton dynamics coupled to gravity. Additionally to the Regge-like spectrum of light- scalar, vector and higher spin mesons, we obtain the decay width of scalar mesons into two pions. |
2211.04403 | Rohan Pramanick | Rohan Pramanick, Tirtha Sankar Ray and Avirup Shaw | Neutrino mass and leptogenesis in a hybrid seesaw model with a
spontaneously broken CP | 28 pages, 4 tables, 10 captioned figures; updated text, new appendix
added | JHEP 06 (2023) 099 | 10.1007/JHEP06(2023)099 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We introduce a novel hybrid framework combining type I and type II seesaw
models for neutrino mass where a complex vacuum expectation value of a singlet
scalar field breaks CP spontaneously. Using pragmatic organizing symmetries we
demonstrate that such a model can simultaneously explain the neutrino
oscillation data and generate observed baryon asymmetry through leptogenesis.
Interestingly, natural choice of parameters leads to a mixed leptogenesis
scenario driven by nearly degenerate scalar triplet and right handed singlet
neutrino fields for which we present a detailed quantitative analysis.
| [
{
"created": "Tue, 8 Nov 2022 17:45:11 GMT",
"version": "v1"
},
{
"created": "Wed, 31 May 2023 17:58:17 GMT",
"version": "v2"
}
] | 2023-06-21 | [
[
"Pramanick",
"Rohan",
""
],
[
"Ray",
"Tirtha Sankar",
""
],
[
"Shaw",
"Avirup",
""
]
] | We introduce a novel hybrid framework combining type I and type II seesaw models for neutrino mass where a complex vacuum expectation value of a singlet scalar field breaks CP spontaneously. Using pragmatic organizing symmetries we demonstrate that such a model can simultaneously explain the neutrino oscillation data and generate observed baryon asymmetry through leptogenesis. Interestingly, natural choice of parameters leads to a mixed leptogenesis scenario driven by nearly degenerate scalar triplet and right handed singlet neutrino fields for which we present a detailed quantitative analysis. |
1205.0362 | A. Tolga Tasci | A. T. Tasci, A. Senol and C. Verep | Analyzing the anomalous dipole moment type couplings of heavy quarks
with FCNC interactions at the CLIC | 13 pages, 10 figures | Advances in High Energy Physics, vol. 2014, Article ID 717848,
2014 | 10.1155/2014/717848 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this study we examine both anomalous magnetic and dipole moment type
couplings of a heavy quark via its single production with subsequent dominant
Standard Model decay modes at the Compact Linear Collider (CLIC). The signal
and background cross sections are analyzed for heavy quark masses 600 and 700
GeV. We make the analysis to delimitate these couplings as well as to find the
attainable integrated luminosities or 3$\sigma$ observation limit.
| [
{
"created": "Wed, 2 May 2012 09:58:17 GMT",
"version": "v1"
},
{
"created": "Wed, 9 May 2012 19:12:17 GMT",
"version": "v2"
},
{
"created": "Thu, 10 Apr 2014 07:26:17 GMT",
"version": "v3"
}
] | 2014-04-15 | [
[
"Tasci",
"A. T.",
""
],
[
"Senol",
"A.",
""
],
[
"Verep",
"C.",
""
]
] | In this study we examine both anomalous magnetic and dipole moment type couplings of a heavy quark via its single production with subsequent dominant Standard Model decay modes at the Compact Linear Collider (CLIC). The signal and background cross sections are analyzed for heavy quark masses 600 and 700 GeV. We make the analysis to delimitate these couplings as well as to find the attainable integrated luminosities or 3$\sigma$ observation limit. |
hep-ph/9907201 | Stephen Mrenna | S. Mrenna (Univ. of California, Davis) | Technihadron Production and Decay at LEP2 | 18 pages (5 figures) in Latex format | Phys.Lett. B461 (1999) 352-362 | 10.1016/S0370-2693(99)00867-9 | UCD-99-13 | hep-ph | null | The simple "straw-man" model of low-scale technicolor contains light
color--singlet technihadrons, which mix with the electroweak gauge bosons. We
present lepton collider production rates at the parton level, and show that
experiments at LEP2 may be sensitive to the presence of technirho and
techniomega states with masses 10-20 GeV beyond the center-of-mass energy
because of the mixing. The exact sensitivity depends on several parameters,
such as the technipion mass, the technipion mixing angle, and the charge of the
technifermions. In an appendix, we describe the implementation of the model
into the event generator PYTHIA for particle-level studies at lepton and hadron
colliders.
| [
{
"created": "Thu, 1 Jul 1999 23:49:32 GMT",
"version": "v1"
}
] | 2016-09-06 | [
[
"Mrenna",
"S.",
"",
"Univ. of California, Davis"
]
] | The simple "straw-man" model of low-scale technicolor contains light color--singlet technihadrons, which mix with the electroweak gauge bosons. We present lepton collider production rates at the parton level, and show that experiments at LEP2 may be sensitive to the presence of technirho and techniomega states with masses 10-20 GeV beyond the center-of-mass energy because of the mixing. The exact sensitivity depends on several parameters, such as the technipion mass, the technipion mixing angle, and the charge of the technifermions. In an appendix, we describe the implementation of the model into the event generator PYTHIA for particle-level studies at lepton and hadron colliders. |
hep-ph/0411296 | Stefan Scherer | Stefan Scherer (J.W.Goethe-Universitaet) | Exotic hadrons from dynamical clustering of quarks in ultrarelativistic
heavy ion collisions | 4 pages, 5 figures, to appear in the proceedings of Strangeness in
Quark Matter 2004 (SQM2004), Cape Town, South Africa, 15-20 September 2004 | J.Phys. G31 (2005) S1199-S1202 | 10.1088/0954-3899/31/6/087 | null | hep-ph | null | Results from a model study on the formation of exotic quark clusters at the
hadronization stage of a heavy ion collision are presented. The dynamical quark
molecular dynamics (qMD) model which is used is sketched, and results for
exotica made of up to six (anti-)quarks are shown. The second part focuses on
pentaquarks. The rapidity distribution are shown, and the distribution of
strangeness is found to yield an indicator of thermalization and homogenisation
of the deconfined quark system. Relative Theta^+ yields are found to be lower
than thermal model estimates.
| [
{
"created": "Mon, 22 Nov 2004 15:55:13 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Scherer",
"Stefan",
"",
"J.W.Goethe-Universitaet"
]
] | Results from a model study on the formation of exotic quark clusters at the hadronization stage of a heavy ion collision are presented. The dynamical quark molecular dynamics (qMD) model which is used is sketched, and results for exotica made of up to six (anti-)quarks are shown. The second part focuses on pentaquarks. The rapidity distribution are shown, and the distribution of strangeness is found to yield an indicator of thermalization and homogenisation of the deconfined quark system. Relative Theta^+ yields are found to be lower than thermal model estimates. |
hep-ph/9807359 | John LoSecco | J.M. LoSecco | Problems with Atmospheric Neutrino Oscillations | 10 pages, 7 figures | null | null | UNDPDK-98-02 | hep-ph hep-ex | null | The neutrino oscillation hypothesis does a poor job of representing the
atmospheric neutrino anomaly. The anomaly is observed over 4 decades in path
length and at least a factor of 30 in energy. This restricts the potential
oscillation solutions to those with large amplitudes and mixing mass
differences that are ruled out by other observations. The $\Delta m^{2}$ region
in the range $10^{-4} - 10^{-2}$ leads to inconsistencies within the
atmospheric neutrino data itself. The observed value of $R$ seems to be
incompatible with the $\Delta m^{2}$ implied by recent results
| [
{
"created": "Mon, 13 Jul 1998 14:50:01 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"LoSecco",
"J. M.",
""
]
] | The neutrino oscillation hypothesis does a poor job of representing the atmospheric neutrino anomaly. The anomaly is observed over 4 decades in path length and at least a factor of 30 in energy. This restricts the potential oscillation solutions to those with large amplitudes and mixing mass differences that are ruled out by other observations. The $\Delta m^{2}$ region in the range $10^{-4} - 10^{-2}$ leads to inconsistencies within the atmospheric neutrino data itself. The observed value of $R$ seems to be incompatible with the $\Delta m^{2}$ implied by recent results |
hep-ph/9511255 | Stefano Bertolini | V. Antonelli, S. Bertolini, J.O. Eeg, M. Fabbrichesi, E.I. Lashin | The $\Delta S = 1$ Weak Chiral Lagrangian as the Effective Theory of the
Chiral Quark Model | Revised version to appear in Nucl. Phys. B 48 pages, uuencoded LATEX
file including 4 eps figures | Nucl.Phys. B469 (1996) 143-180 | 10.1016/0550-3213(96)00144-7 | SISSA 43/95/EP | hep-ph | null | We use the chiral quark model to estimate the coefficients of the weak chiral
lagrangian as obtained from the bosonization of the ten relevant operators of
the $\Delta S = 1$ effective quark lagrangian. All contributions of order
$N_c^2$ as well as $N_c$ and $\alpha_s N_c$ are included. The chiral
coefficients are given in terms of $f_{\pi}$, the quark and gluon condensates
and the scale-dependent NLO Wilson coefficients of the corresponding operators.
In addition, they depend on the constituent quark mass $M$, a parameter
characteristic of the model. The $\gamma_5$-scheme dependence of the chiral
coefficients, computed via dimensional regularization, and the Fierz
transformation properties of the operator basis are discussed in detail. We
apply our result to the evaluation of the hadronic matrix elements for the
decay $K^0 \rightarrow 2 \pi$, consistently including the renormalization
induced by the meson loops. The effect of this renormalization is sizable and
introduces a long-distance scale dependence that matches in the physical
amplitudes the short-distance scale dependence of the Wilson coefficients.
| [
{
"created": "Tue, 7 Nov 1995 08:20:55 GMT",
"version": "v1"
},
{
"created": "Tue, 14 Nov 1995 11:43:04 GMT",
"version": "v2"
},
{
"created": "Wed, 13 Mar 1996 15:03:10 GMT",
"version": "v3"
},
{
"created": "Tue, 11 Jun 1996 08:16:15 GMT",
"version": "v4"
}
] | 2009-10-28 | [
[
"Antonelli",
"V.",
""
],
[
"Bertolini",
"S.",
""
],
[
"Eeg",
"J. O.",
""
],
[
"Fabbrichesi",
"M.",
""
],
[
"Lashin",
"E. I.",
""
]
] | We use the chiral quark model to estimate the coefficients of the weak chiral lagrangian as obtained from the bosonization of the ten relevant operators of the $\Delta S = 1$ effective quark lagrangian. All contributions of order $N_c^2$ as well as $N_c$ and $\alpha_s N_c$ are included. The chiral coefficients are given in terms of $f_{\pi}$, the quark and gluon condensates and the scale-dependent NLO Wilson coefficients of the corresponding operators. In addition, they depend on the constituent quark mass $M$, a parameter characteristic of the model. The $\gamma_5$-scheme dependence of the chiral coefficients, computed via dimensional regularization, and the Fierz transformation properties of the operator basis are discussed in detail. We apply our result to the evaluation of the hadronic matrix elements for the decay $K^0 \rightarrow 2 \pi$, consistently including the renormalization induced by the meson loops. The effect of this renormalization is sizable and introduces a long-distance scale dependence that matches in the physical amplitudes the short-distance scale dependence of the Wilson coefficients. |
1210.7153 | Enrique Ruiz Arriola | Enrique Ruiz Arriola, Wojciech Broniowski, Pere Masjuan | Hadron resonances, large Nc, and the half-width rule | 6 pages, 4 figures. Presented by ERA at Light Cone 2012, Cracow, 8-13
July 2012 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We suggest using the half-width rule to make an estimate of the 1/Nc errors
in hadronic models containing resonances. We show simple consequences ranging
from the analysis of meson Regge trajectories, the hadron resonance gas at
finite temperature and generalized hadronic form factors.
| [
{
"created": "Fri, 26 Oct 2012 14:22:09 GMT",
"version": "v1"
}
] | 2012-10-29 | [
[
"Arriola",
"Enrique Ruiz",
""
],
[
"Broniowski",
"Wojciech",
""
],
[
"Masjuan",
"Pere",
""
]
] | We suggest using the half-width rule to make an estimate of the 1/Nc errors in hadronic models containing resonances. We show simple consequences ranging from the analysis of meson Regge trajectories, the hadron resonance gas at finite temperature and generalized hadronic form factors. |
1009.6095 | Giovanni Marco Pruna Mr | L. Basso, A. Belyaev, S. Moretti and G. M. Pruna | Higgs phenomenology in the minimal $B-L$ extension of the Standard Model
at LHC | 6 pages, 3 figures, PASCOS2010 International Symposium proceeding | J.Phys.Conf.Ser.259:012062,2010 | 10.1088/1742-6596/259/1/012062 | 10-32 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present some phenomenology of the Higgs sector of the Minimal $B-L$ U(1)
Extension of the Standard Model at the Large Hadron Collider. In this model,
the existence of an extra gauge boson ($Z'$) and an extra scalar (heavy Higgs)
are predicted as naturally related with the breaking of the $B-L$ (baryon minus
lepton number) symmetry. For this, we have started by deriving the unitarity
bounds in the high energy limit for the Minimal $B-L$ Model parameter space.
This was accomplished by analysing the full class of Higgs and would-be
Goldstone boson two-to-two scatterings at tree level (exploiting the
Equivalence Theorem). Hence, we studied some peculiar signature that could be
observed at the CERN machine in the search of both light and heavy Higgs
bosons.
| [
{
"created": "Thu, 30 Sep 2010 10:37:58 GMT",
"version": "v1"
},
{
"created": "Mon, 1 Nov 2010 23:55:29 GMT",
"version": "v2"
}
] | 2011-01-03 | [
[
"Basso",
"L.",
""
],
[
"Belyaev",
"A.",
""
],
[
"Moretti",
"S.",
""
],
[
"Pruna",
"G. M.",
""
]
] | We present some phenomenology of the Higgs sector of the Minimal $B-L$ U(1) Extension of the Standard Model at the Large Hadron Collider. In this model, the existence of an extra gauge boson ($Z'$) and an extra scalar (heavy Higgs) are predicted as naturally related with the breaking of the $B-L$ (baryon minus lepton number) symmetry. For this, we have started by deriving the unitarity bounds in the high energy limit for the Minimal $B-L$ Model parameter space. This was accomplished by analysing the full class of Higgs and would-be Goldstone boson two-to-two scatterings at tree level (exploiting the Equivalence Theorem). Hence, we studied some peculiar signature that could be observed at the CERN machine in the search of both light and heavy Higgs bosons. |
hep-ph/0312299 | Hans-Christian Pauli | Hans-Christian Pauli | A linear potential in a light cone QCD inspired model | LaTeX2e, 5 pages, 11 references. Paper 4 of 5 | null | null | null | hep-ph | null | The general equation from previous work is specialized to a linear potential
$V(r)=-a+F r$ acting in the space of spherically symmetric S wave functions.
The fine and hyperfine interaction creates then a $\frac1r$-dependence in the
effective potential energy equation and a position dependent mass $\widetilde
m(r)$ in the effective kinetic energy of the associated Schr\"odinger equation.
The results are compared with the available experimental and theoretical
spectral data on the $\pi$ and $\rho$. Solving the eigenvalue problem within
the analytically tractable Airy-function approach induces a certain amount of
arbitrariness (fudge factors). Despite of this, the agreement with experimental
data is good and partially better than other calculations, including Godfrey
and Isgur \cite{GodIsg85} and Baldicchi and Prosperi \cite{BalPro02}. The short
comings of the present model can be removed easily in more elaborate work.
| [
{
"created": "Sat, 20 Dec 2003 19:21:56 GMT",
"version": "v1"
}
] | 2016-08-16 | [
[
"Pauli",
"Hans-Christian",
""
]
] | The general equation from previous work is specialized to a linear potential $V(r)=-a+F r$ acting in the space of spherically symmetric S wave functions. The fine and hyperfine interaction creates then a $\frac1r$-dependence in the effective potential energy equation and a position dependent mass $\widetilde m(r)$ in the effective kinetic energy of the associated Schr\"odinger equation. The results are compared with the available experimental and theoretical spectral data on the $\pi$ and $\rho$. Solving the eigenvalue problem within the analytically tractable Airy-function approach induces a certain amount of arbitrariness (fudge factors). Despite of this, the agreement with experimental data is good and partially better than other calculations, including Godfrey and Isgur \cite{GodIsg85} and Baldicchi and Prosperi \cite{BalPro02}. The short comings of the present model can be removed easily in more elaborate work. |
hep-ph/0311011 | Dr. Rukmani Mohanta | A.K.Giri and R.Mohanta | Direct CP violation and new physics effects in the decay mode B^+ -> phi
K^+ | 17 pages, 2 figures, typos corrected, more references added, to be
published in Modern Physics Letters A | Mod.Phys.Lett. A19 (2004) 1903-1918 | 10.1142/S021773230401518X | null | hep-ph | null | We study the direct CP violation effect in the decay mode $B^+ \to \phi K^+$.
This decay mode is dominated by the loop induced $\bar b \to \bar s s \bar s$
penguin diagram with a tiny contribution from annihilation diagram. Therefore,
the standard model expectation of direct CP violation is negligibly small.
Using QCD factorization approach we find the CP asymmetry in the standard model
to be at percent level. We consider then two scenarios beyond the standard
model, the model with an extra vector like down quark (VLDQ) and the R-parity
violating supersymmetric model (RPV) and show that the direct CP violating
asymmetry in $B^+ \to \phi K^+ $ could be as large as ~85% (70%) in VLDQ (RPV)
model.
| [
{
"created": "Sun, 2 Nov 2003 03:48:31 GMT",
"version": "v1"
},
{
"created": "Tue, 4 Nov 2003 10:02:05 GMT",
"version": "v2"
},
{
"created": "Tue, 29 Jun 2004 07:01:32 GMT",
"version": "v3"
}
] | 2009-11-10 | [
[
"Giri",
"A. K.",
""
],
[
"Mohanta",
"R.",
""
]
] | We study the direct CP violation effect in the decay mode $B^+ \to \phi K^+$. This decay mode is dominated by the loop induced $\bar b \to \bar s s \bar s$ penguin diagram with a tiny contribution from annihilation diagram. Therefore, the standard model expectation of direct CP violation is negligibly small. Using QCD factorization approach we find the CP asymmetry in the standard model to be at percent level. We consider then two scenarios beyond the standard model, the model with an extra vector like down quark (VLDQ) and the R-parity violating supersymmetric model (RPV) and show that the direct CP violating asymmetry in $B^+ \to \phi K^+ $ could be as large as ~85% (70%) in VLDQ (RPV) model. |
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