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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
2206.14243 | Ashik Ikbal Sheikh | Ashik Ikbal Sheikh | Effect of thermal gluon absorption and medium fluctuations on heavy
flavour nuclear modification factor at RHIC and LHC energies | Published in EPJA | Eur. Phys. J. A 57, 323 (2021) | 10.1140/epja/s10050-021-00636-z | null | hep-ph nucl-ex nucl-th | http://creativecommons.org/licenses/by-sa/4.0/ | The presence of thermal gluons reduces the stimulated gluon emission off a
heavy quark propagating in the quark-gluon plasma (QGP) while absorption causes
reduction of the radiative energy loss. On the other hand, the
chromo-electromagnetic field fluctuations present in the QGP lead to
collisional energy gain of the heavy quark. The net effect of the thermal gluon
absorption and field fluctuations is a reduction of the total energy loss of
the heavy quark, prominent at the lower momenta. We consider both kind of the
energy gains along with the usual losses, and compute the nuclear modification
factor ($R_{AA}$) of heavy mesons, viz., $D$ and $B$ mesons. The calculations
have been compared with the experimental measurements in Au-Au collisions at
$\sqrt{s_{NN}} = 200$ GeV from STAR and PHENIX experiments at the RHIC and
Pb-Pb collisions at $\sqrt{s_{NN}} = 2.76$ TeV and $5.02$ TeV from CMS and
ALICE experiments at the LHC. We find a significant effect of the total energy
gain due to thermal gluon absorption and field fluctuations on heavy flavour
suppression, especially at the lower transverse momenta.
| [
{
"created": "Tue, 28 Jun 2022 18:40:30 GMT",
"version": "v1"
}
] | 2022-06-30 | [
[
"Sheikh",
"Ashik Ikbal",
""
]
] | The presence of thermal gluons reduces the stimulated gluon emission off a heavy quark propagating in the quark-gluon plasma (QGP) while absorption causes reduction of the radiative energy loss. On the other hand, the chromo-electromagnetic field fluctuations present in the QGP lead to collisional energy gain of the heavy quark. The net effect of the thermal gluon absorption and field fluctuations is a reduction of the total energy loss of the heavy quark, prominent at the lower momenta. We consider both kind of the energy gains along with the usual losses, and compute the nuclear modification factor ($R_{AA}$) of heavy mesons, viz., $D$ and $B$ mesons. The calculations have been compared with the experimental measurements in Au-Au collisions at $\sqrt{s_{NN}} = 200$ GeV from STAR and PHENIX experiments at the RHIC and Pb-Pb collisions at $\sqrt{s_{NN}} = 2.76$ TeV and $5.02$ TeV from CMS and ALICE experiments at the LHC. We find a significant effect of the total energy gain due to thermal gluon absorption and field fluctuations on heavy flavour suppression, especially at the lower transverse momenta. |
2103.08407 | Ritesh Ghosh | Ritesh Ghosh, Bithika Karmakar and Munshi Golam Mustafa | Chiral susceptibility in dense thermo-magnetic QCD medium within HTL
approximation | 22 pages, 5 figures | Phys. Rev. D 103, 074019 (2021) | 10.1103/PhysRevD.103.074019 | null | hep-ph hep-lat nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We have computed the chiral susceptibility in quark-gluon plasma in presence
of finite chemical potential and weak magnetic field within hard thermal loop
approximation. First we construct the massive effective quark propagator in a
thermomagnetic medium. Then we obtain completely analytic expression for the
chiral susceptibility in weak magnetic field approximation. In the absence of
magnetic field the thermal chiral susceptibility increases in presence of
finite chemical potential. The effect of thermomagnetic correction is found to
be very marginal as temperature is the dominant scale in weak field
approximation.
| [
{
"created": "Mon, 15 Mar 2021 14:33:24 GMT",
"version": "v1"
}
] | 2021-04-28 | [
[
"Ghosh",
"Ritesh",
""
],
[
"Karmakar",
"Bithika",
""
],
[
"Mustafa",
"Munshi Golam",
""
]
] | We have computed the chiral susceptibility in quark-gluon plasma in presence of finite chemical potential and weak magnetic field within hard thermal loop approximation. First we construct the massive effective quark propagator in a thermomagnetic medium. Then we obtain completely analytic expression for the chiral susceptibility in weak magnetic field approximation. In the absence of magnetic field the thermal chiral susceptibility increases in presence of finite chemical potential. The effect of thermomagnetic correction is found to be very marginal as temperature is the dominant scale in weak field approximation. |
1703.09532 | Vladimir Braun M | V. M. Braun, A. N. Manashov, S. Moch and M. Strohmaier | Three-loop evolution equation for flavor-nonsinglet operators in
off-forward kinematics | 31 pages, 2 figures | null | 10.1007/JHEP06(2017)037 | DESY 17-045 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Using the approach based on conformal symmetry we calculate the three-loop
(NNLO) contribution to the evolution equation for flavor-nonsinglet leading
twist operators in the $\overline{\text{MS}}$ scheme. The explicit expression
for the three-loop kernel is derived for the corresponding light-ray operator
in coordinate space. The expansion in local operators is performed and explicit
results are given for the matrix of the anomalous dimensions for the operators
up to seven covariant derivatives. The results are directly applicable to the
renormalization of the pion light-cone distribution amplitude and
flavor-nonsinglet generalized parton distributions.
| [
{
"created": "Tue, 28 Mar 2017 12:15:29 GMT",
"version": "v1"
}
] | 2017-06-28 | [
[
"Braun",
"V. M.",
""
],
[
"Manashov",
"A. N.",
""
],
[
"Moch",
"S.",
""
],
[
"Strohmaier",
"M.",
""
]
] | Using the approach based on conformal symmetry we calculate the three-loop (NNLO) contribution to the evolution equation for flavor-nonsinglet leading twist operators in the $\overline{\text{MS}}$ scheme. The explicit expression for the three-loop kernel is derived for the corresponding light-ray operator in coordinate space. The expansion in local operators is performed and explicit results are given for the matrix of the anomalous dimensions for the operators up to seven covariant derivatives. The results are directly applicable to the renormalization of the pion light-cone distribution amplitude and flavor-nonsinglet generalized parton distributions. |
1111.6765 | Vladimir Braun M | V. M. Braun and A. N. Manashov | Operator product expansion in QCD in off-forward kinematics: Separation
of kinematic and dynamical contributions | 68 pages, 2 figures. Misprints in Eq.(5.64) and several equations in
Sec.6 are corrected. For readers' convenience all corrections are marked in
red | JHEP 1201 (2012) 085 | 10.1007/JHEP01(2012)085 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We develop a general approach to the calculation of target mass and finite
t=(p'-p)^2 corrections in hard processes which can be studied in the framework
of the operator product expansion and involve momentum transfer from the
initial to the final hadron state. Such corrections, which are usually referred
to as kinematic, can be defined as contributions of operators of all twists
that can be reduced to total derivatives of the leading twist operators. As the
principal result, we provide a set of projection operators that pick up the
"kinematic" part of an arbitrary flavor-nonsinglet twist-four operator in QCD.
A complete expression is derived for the time-ordered product of two
electromagnetic currents that includes all kinematic corrections to twist-four
accuracy. The results are immediately applicable to the studies of
deeply-virtual Compton scattering, transition gamma^*-> M gamma form factors
and related processes. As a byproduct of this study, we find a series of
"genuine" twist-four flavor-nonsinglet quark-antiquark-gluon operators which
have the same anomalous dimensions as the leading twist quark-antiquark
operators.
| [
{
"created": "Tue, 29 Nov 2011 11:20:04 GMT",
"version": "v1"
},
{
"created": "Thu, 11 Apr 2013 11:21:24 GMT",
"version": "v2"
}
] | 2015-06-03 | [
[
"Braun",
"V. M.",
""
],
[
"Manashov",
"A. N.",
""
]
] | We develop a general approach to the calculation of target mass and finite t=(p'-p)^2 corrections in hard processes which can be studied in the framework of the operator product expansion and involve momentum transfer from the initial to the final hadron state. Such corrections, which are usually referred to as kinematic, can be defined as contributions of operators of all twists that can be reduced to total derivatives of the leading twist operators. As the principal result, we provide a set of projection operators that pick up the "kinematic" part of an arbitrary flavor-nonsinglet twist-four operator in QCD. A complete expression is derived for the time-ordered product of two electromagnetic currents that includes all kinematic corrections to twist-four accuracy. The results are immediately applicable to the studies of deeply-virtual Compton scattering, transition gamma^*-> M gamma form factors and related processes. As a byproduct of this study, we find a series of "genuine" twist-four flavor-nonsinglet quark-antiquark-gluon operators which have the same anomalous dimensions as the leading twist quark-antiquark operators. |
hep-ph/0301122 | Thomas A. Trainor | Thomas A. Trainor | What Does the Balance Function Measure? | 16 pages, 5 figures | null | null | null | hep-ph | null | The balance function has been proposed to `clock' hadronization by measuring
the charge-dependent correlation length on rapidity. According to the proposal
a narrowed balance function would imply reduced hadron diffusion time and
therefore delayed hadronization due to a long-lived prehadronic state, a
quark-gluon plasma or QGP. I examine this chain of argument in the context of
hadronization and rescattering. I then consider the algebraic structure of the
balance function and its systematic dependence on the charge correlation length
on rapidity. I conclude that the width of the balance function cannot determine
a time interval from hadronization to kinetic decoupling, nor can the width
determine the existence or temporal extent of a QGP.
| [
{
"created": "Thu, 16 Jan 2003 19:49:59 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Trainor",
"Thomas A.",
""
]
] | The balance function has been proposed to `clock' hadronization by measuring the charge-dependent correlation length on rapidity. According to the proposal a narrowed balance function would imply reduced hadron diffusion time and therefore delayed hadronization due to a long-lived prehadronic state, a quark-gluon plasma or QGP. I examine this chain of argument in the context of hadronization and rescattering. I then consider the algebraic structure of the balance function and its systematic dependence on the charge correlation length on rapidity. I conclude that the width of the balance function cannot determine a time interval from hadronization to kinetic decoupling, nor can the width determine the existence or temporal extent of a QGP. |
hep-ph/0506088 | Dean Lee J | Dean Lee, Richard Thomson | Mass inequality for the quark propagator | 8 pages, no figures | null | null | null | hep-ph hep-lat nucl-th | null | We show that for any gauge-fixing scheme with positive semi-definite
functional integral measure, the inverse correlation length of the quark
propagator is bounded below by one-half the pion mass.
| [
{
"created": "Thu, 9 Jun 2005 02:05:33 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Lee",
"Dean",
""
],
[
"Thomson",
"Richard",
""
]
] | We show that for any gauge-fixing scheme with positive semi-definite functional integral measure, the inverse correlation length of the quark propagator is bounded below by one-half the pion mass. |
2407.01181 | Valery Lyubovitskij | Sergei N. Gninenko, Dmitry V. Kirpichnikov, Nikolai V. Krasnikov,
Sergey Kuleshov, Valery E. Lyubovitskij, Alexey S. Zhevlakov | Probing leptophobic dark sector with a pseudoscalar portal in the NA64
experiment at CERN | 17 pages, 1 figure | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We consider the possibility of discovering a light pseudoscalar particle $a$,
which could the axion or an axion-like particle (ALP), interacting mainly with
quarks using the electron and photon scattering reaction chain $e + Z
\rightarrow e + \gamma + Z$; $\gamma + Z \rightarrow a + Z$ on nuclei in the
NA64 experiment at the CERN SPS. New bounds on the coupling strengths of the
axion/ALP with quarks and of pseudoscalar mesons $P = \pi, \eta, \eta'$ with
dark fermions are obtained by using existing upper bounds on invisible decay
modes of $P$s including those recently derived by NA64. We also study a
scenario when the $a$ plays the role of a messenger in the communication
between our world and the dark sector.
| [
{
"created": "Mon, 1 Jul 2024 11:14:03 GMT",
"version": "v1"
}
] | 2024-07-02 | [
[
"Gninenko",
"Sergei N.",
""
],
[
"Kirpichnikov",
"Dmitry V.",
""
],
[
"Krasnikov",
"Nikolai V.",
""
],
[
"Kuleshov",
"Sergey",
""
],
[
"Lyubovitskij",
"Valery E.",
""
],
[
"Zhevlakov",
"Alexey S.",
""
]
] | We consider the possibility of discovering a light pseudoscalar particle $a$, which could the axion or an axion-like particle (ALP), interacting mainly with quarks using the electron and photon scattering reaction chain $e + Z \rightarrow e + \gamma + Z$; $\gamma + Z \rightarrow a + Z$ on nuclei in the NA64 experiment at the CERN SPS. New bounds on the coupling strengths of the axion/ALP with quarks and of pseudoscalar mesons $P = \pi, \eta, \eta'$ with dark fermions are obtained by using existing upper bounds on invisible decay modes of $P$s including those recently derived by NA64. We also study a scenario when the $a$ plays the role of a messenger in the communication between our world and the dark sector. |
hep-ph/0306145 | Rasulkhozha S. Sharafiddinov | Rasulkhozha S. Sharafiddinov | Mass of the Neutrino and Its Axial-Vector Electromagnetic Nature | 4 pages, LaTex. This version is better for pdf | Spacetime Subst. 5 (2004) 32-33 | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A neutrino possesses the anapole and electric dipole moments. Their
interaction with field of emission can also lead to the neutrino elastic
scattering by spinless nuclei. In this letter, we present some implications
implied from the process cross sections. One of them states that there exists a
hard connection between the neutrino magnetic and anapole moments. An equation
for the anapole and electric dipole form factors is also obtained. They define
the electronic neutrino axial-vector moments. All findings are generalized to
the case of a Majorana neutrino.
| [
{
"created": "Tue, 17 Jun 2003 03:52:30 GMT",
"version": "v1"
},
{
"created": "Mon, 7 Jun 2004 08:27:10 GMT",
"version": "v2"
},
{
"created": "Thu, 9 Dec 2010 07:42:40 GMT",
"version": "v3"
}
] | 2010-12-10 | [
[
"Sharafiddinov",
"Rasulkhozha S.",
""
]
] | A neutrino possesses the anapole and electric dipole moments. Their interaction with field of emission can also lead to the neutrino elastic scattering by spinless nuclei. In this letter, we present some implications implied from the process cross sections. One of them states that there exists a hard connection between the neutrino magnetic and anapole moments. An equation for the anapole and electric dipole form factors is also obtained. They define the electronic neutrino axial-vector moments. All findings are generalized to the case of a Majorana neutrino. |
1607.08241 | Christoph Gnendiger | Christoph Gnendiger, Adrian Signer, Andrea Visconti | Regularization-scheme dependence of QCD amplitudes in the massive case | 24 pages, 9 figures, small changes in the text, references updated | null | 10.1007/JHEP10(2016)034 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate QCD amplitudes with massive quarks computed in the
four-dimensional helicity scheme (FDH) and dimensional reduction at NNLO and
describe how they are related to the corresponding amplitudes computed in
conventional dimensional regularization. To this end, the scheme dependence of
the heavy quark and the velocity-dependent cusp anomalous dimensions is
determined using soft-collinear effective theory. The results are checked
against explicit computations of massive form factors in FDH at NNLO. Our
results complete the description of the scheme dependence of QCD amplitudes at
NNLO.
| [
{
"created": "Wed, 27 Jul 2016 20:00:02 GMT",
"version": "v1"
},
{
"created": "Wed, 5 Oct 2016 15:09:13 GMT",
"version": "v2"
}
] | 2016-11-23 | [
[
"Gnendiger",
"Christoph",
""
],
[
"Signer",
"Adrian",
""
],
[
"Visconti",
"Andrea",
""
]
] | We investigate QCD amplitudes with massive quarks computed in the four-dimensional helicity scheme (FDH) and dimensional reduction at NNLO and describe how they are related to the corresponding amplitudes computed in conventional dimensional regularization. To this end, the scheme dependence of the heavy quark and the velocity-dependent cusp anomalous dimensions is determined using soft-collinear effective theory. The results are checked against explicit computations of massive form factors in FDH at NNLO. Our results complete the description of the scheme dependence of QCD amplitudes at NNLO. |
0710.1321 | Pavel Fileviez Perez | Pavel Fileviez Perez (UW-Madison) | Unification with and without Supersymmetry: Adjoint SU(5) | Submitted for the SUSY07 proceedings | null | null | null | hep-ph | null | I present two new renormalizable grand unified theories where the neutrino
masses are generated through the type I and type III seesaw mechanisms. These
theories can be considered as the simplest (SUSY) renormalizable grand unified
theories based on the SU(5) gauge symmetry. Several phenomenological and
cosmological aspects of these proposals are discussed.
| [
{
"created": "Fri, 5 Oct 2007 22:37:48 GMT",
"version": "v1"
}
] | 2007-10-11 | [
[
"Perez",
"Pavel Fileviez",
"",
"UW-Madison"
]
] | I present two new renormalizable grand unified theories where the neutrino masses are generated through the type I and type III seesaw mechanisms. These theories can be considered as the simplest (SUSY) renormalizable grand unified theories based on the SU(5) gauge symmetry. Several phenomenological and cosmological aspects of these proposals are discussed. |
1511.05518 | Stanislav Iablokov | Stanislav Iablokov | Quantum Cherenkov radiation by spinless and spin-1/2 particles | null | null | null | null | hep-ph physics.optics quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper, the Cherenkov radiation process is investigated in the frame
of the Quantum Field Theory, both for the spinless and spin-1/2 charged
particles. In the latter case, the polarization density matrix technique was
used to account for the spin flip. If compared with the Classical
Electrodynamics results, in both cases several quantum corrections arise,
coinciding up to the photon's energy linear term. It is shown that, while the
absolute value of these corrections significantly relies on the refractive
index, the relative quantum correction stays independent of the medium in the
case of the ultrarelativistic particles. It the case of the spin-1/2 particles
it turns out that the spin flip practically never occurs in this process. For
both cases, spinless and spin-1/2, the outgoing photon polarization vector lies
always in the plane formed by the initial particle's momentum vector and the
final photon's wave vector.
| [
{
"created": "Tue, 17 Nov 2015 19:41:34 GMT",
"version": "v1"
}
] | 2015-11-18 | [
[
"Iablokov",
"Stanislav",
""
]
] | In this paper, the Cherenkov radiation process is investigated in the frame of the Quantum Field Theory, both for the spinless and spin-1/2 charged particles. In the latter case, the polarization density matrix technique was used to account for the spin flip. If compared with the Classical Electrodynamics results, in both cases several quantum corrections arise, coinciding up to the photon's energy linear term. It is shown that, while the absolute value of these corrections significantly relies on the refractive index, the relative quantum correction stays independent of the medium in the case of the ultrarelativistic particles. It the case of the spin-1/2 particles it turns out that the spin flip practically never occurs in this process. For both cases, spinless and spin-1/2, the outgoing photon polarization vector lies always in the plane formed by the initial particle's momentum vector and the final photon's wave vector. |
2307.04168 | Chen Rui | Rui Chen, Qi Huang | Possible open charm molecular pentaquarks from
$\Lambda_cK^{(*)}/\Sigma_cK^{(*)}$ interactions | 9 pages, 1 figure. arXiv admin note: text overlap with
arXiv:2208.10196 | Phys. Rev. D 108, 054011 (2023) | 10.1103/PhysRevD.108.054011 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | In this work, we adopt the one-boson-exchange model to study the $Y_cK^{(*)}
(Y_c=\Lambda_c, \Sigma_c)$ interactions. After considering both of the $S-D$
wave mixing effects and the coupled channel effects, we can predict several
possible open-charm molecular pentaquarks, i.e., the single $\Sigma_cK^*$
molecular states with $I(J^P)=1/2(1/2^-)$, $1/2(3/2^-)$ and $3/2(1/2^-)$, the
coupled $\Lambda_cK^*/\Sigma_cK^*$ molecular states with $1/2(1/2^-)$ and
$1/2(3/2^-)$, and the coupled $\Sigma_cK/\Lambda_cK^*/\Sigma_cK^*$ molecular
state with $1/2(1/2^-)$. Meanwhile, we extend our study to the
$Y_c\bar{K}^{(*)}$ interactions, our results suggest the $\Sigma_c\bar{K}$
system with $I(J^P)=1/2(1/2^-)$, the $\Sigma_c\bar{K}^*$ systems with
$1/2(1/2^-)$, $1/2(3/2^-)$, and $3/2(3/2^-)$, the coupled
$\Lambda_c\bar{K}^*/\Sigma_c\bar K^*$ system with $1/2(1/2^-)$, and the
$\Sigma_c\bar{K}/\Lambda_c\bar{K}^*/\Sigma_c\bar K^*$ system with $1/2(1/2^-)$
can be the prime molecular candidates.
| [
{
"created": "Sun, 9 Jul 2023 13:30:56 GMT",
"version": "v1"
}
] | 2023-09-28 | [
[
"Chen",
"Rui",
""
],
[
"Huang",
"Qi",
""
]
] | In this work, we adopt the one-boson-exchange model to study the $Y_cK^{(*)} (Y_c=\Lambda_c, \Sigma_c)$ interactions. After considering both of the $S-D$ wave mixing effects and the coupled channel effects, we can predict several possible open-charm molecular pentaquarks, i.e., the single $\Sigma_cK^*$ molecular states with $I(J^P)=1/2(1/2^-)$, $1/2(3/2^-)$ and $3/2(1/2^-)$, the coupled $\Lambda_cK^*/\Sigma_cK^*$ molecular states with $1/2(1/2^-)$ and $1/2(3/2^-)$, and the coupled $\Sigma_cK/\Lambda_cK^*/\Sigma_cK^*$ molecular state with $1/2(1/2^-)$. Meanwhile, we extend our study to the $Y_c\bar{K}^{(*)}$ interactions, our results suggest the $\Sigma_c\bar{K}$ system with $I(J^P)=1/2(1/2^-)$, the $\Sigma_c\bar{K}^*$ systems with $1/2(1/2^-)$, $1/2(3/2^-)$, and $3/2(3/2^-)$, the coupled $\Lambda_c\bar{K}^*/\Sigma_c\bar K^*$ system with $1/2(1/2^-)$, and the $\Sigma_c\bar{K}/\Lambda_c\bar{K}^*/\Sigma_c\bar K^*$ system with $1/2(1/2^-)$ can be the prime molecular candidates. |
2110.01236 | Phung Van Dong | Duong Van Loi, Phung Van Dong | Gauge origin of double dark parity and implication for dark matter | 18 pages, 3 figures | Commun.in Phys. 32 (2022) 101 | 10.15625/0868-3166/16784 | null | hep-ph hep-th | http://creativecommons.org/licenses/by/4.0/ | Dark matter must be stabilized over the cosmological timescale, which demands
the existence of a stabilizing symmetry, derived by a dark charge, $D$. The
existence of this dark charge may affect the quantization of electric charge,
which theoretically shifts the electric charge, thus the hypercharge to a novel
gauge extension, $SU(3)_C\otimes SU(2)_L\otimes U(1)_Y\otimes U(1)_N$, where
$N$ determines $D=T_3+N$, similar to $Q=T_3+Y$. New observation of this work is
that the dark charge is broken down to two kinds of dark parity, $Z_2$ and
$Z'_2$, which subsequently imply three scenarios of dark matter. The relic
density and direct detection for the scenario of two-component dark matter are
investigated in detail.
| [
{
"created": "Mon, 4 Oct 2021 07:57:53 GMT",
"version": "v1"
}
] | 2022-05-10 | [
[
"Van Loi",
"Duong",
""
],
[
"Van Dong",
"Phung",
""
]
] | Dark matter must be stabilized over the cosmological timescale, which demands the existence of a stabilizing symmetry, derived by a dark charge, $D$. The existence of this dark charge may affect the quantization of electric charge, which theoretically shifts the electric charge, thus the hypercharge to a novel gauge extension, $SU(3)_C\otimes SU(2)_L\otimes U(1)_Y\otimes U(1)_N$, where $N$ determines $D=T_3+N$, similar to $Q=T_3+Y$. New observation of this work is that the dark charge is broken down to two kinds of dark parity, $Z_2$ and $Z'_2$, which subsequently imply three scenarios of dark matter. The relic density and direct detection for the scenario of two-component dark matter are investigated in detail. |
hep-ph/9801446 | Michael Graesser | K. Agashe and M. Graesser (UC Berkeley and LBNL) | Supersymmetry Breaking and the Supersymmetric Flavour Problem: An
Analysis of Decoupling the First Two Generation Scalars | Latex, 40 pages, 14 figures. Replacing an earlier version of the
manuscript. Extra section added discussing limits on $\delta$ from
finetuning, positivity and $\Delta m_K$. Earlier version did not include the
one-loop hypercharge $D-$term; this has been corrected, and our conclusions
remain unchanged | Phys.Rev.D59:015007,1999 | 10.1103/PhysRevD.59.015007 | LBNL-41338, UCB-PTH-97/65 | hep-ph | null | The supersymmetric contributions to the Flavor Changing Neutral Current
processes may be suppressed by decoupling the scalars of the first and second
generations. It is known, however, that the heavy scalars drive the stop mass
squareds negative through the two-loop Renormalization Group evolution. This
tension is studied in detail. Two new items are included in this analysis: the
effect of the top quark Yukawa coupling and the QCD corrections to the
supersymmetric contributions to $\Delta m_K$. Even with Cabibbo-like degeneracy
between the squarks of the first two generations, these squarks must be heavier
than $\sim 40$ TeV to suppress $\Delta m_K$. This implies, in the case of a
high scale of supersymmetry breaking, that the boundary value of the stop mass
has to be greater than $\sim 7$ TeV to keep the stop mass squared positive at
the weak scale. Low-energy supersymmetry breaking at a scale that is of the
same order as the mass of the heavy scalars is also considered. In this case
the finite parts of the two-loop diagrams are computed to estimate the
contribution of the heavy scalar masses to the stop mass squared. It is found
that for Cabibbo-like mixing between the squarks, the stop mass at the boundary
needs to be larger than $\sim 2$ TeV. Thus, for both cases, the large boundary
value of the stop masses leads to an unnatural amount of fine tuning to obtain
the correct $Z$ mass.
| [
{
"created": "Thu, 29 Jan 1998 23:53:23 GMT",
"version": "v1"
},
{
"created": "Wed, 1 Jul 1998 21:20:50 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"Agashe",
"K.",
"",
"UC Berkeley and LBNL"
],
[
"Graesser",
"M.",
"",
"UC Berkeley and LBNL"
]
] | The supersymmetric contributions to the Flavor Changing Neutral Current processes may be suppressed by decoupling the scalars of the first and second generations. It is known, however, that the heavy scalars drive the stop mass squareds negative through the two-loop Renormalization Group evolution. This tension is studied in detail. Two new items are included in this analysis: the effect of the top quark Yukawa coupling and the QCD corrections to the supersymmetric contributions to $\Delta m_K$. Even with Cabibbo-like degeneracy between the squarks of the first two generations, these squarks must be heavier than $\sim 40$ TeV to suppress $\Delta m_K$. This implies, in the case of a high scale of supersymmetry breaking, that the boundary value of the stop mass has to be greater than $\sim 7$ TeV to keep the stop mass squared positive at the weak scale. Low-energy supersymmetry breaking at a scale that is of the same order as the mass of the heavy scalars is also considered. In this case the finite parts of the two-loop diagrams are computed to estimate the contribution of the heavy scalar masses to the stop mass squared. It is found that for Cabibbo-like mixing between the squarks, the stop mass at the boundary needs to be larger than $\sim 2$ TeV. Thus, for both cases, the large boundary value of the stop masses leads to an unnatural amount of fine tuning to obtain the correct $Z$ mass. |
hep-ph/0303258 | N. D. Tracas | A. Prikas, N.D. Tracas (National Technical University, Athens, Greece) | Gauge Unification and Quark Masses in a Pati-Salam Model from Branes | 11 pages, LaTeX, 7 figures included | New J.Phys. 5 (2003) 144 | 10.1088/1367-2630/5/1/144 | null | hep-ph | null | We investigate the phase space of parameters in the Pati-Salam model derived
in the context of D-branes scenarios, requiring low energy string scale. We
find that a non-supersymmetric version complies with a string scale as low as
10 TeV, while in the supersymmetric version the string scale raises up to ~2 x
10^7 TeV. The limited energy region for RGE running demands a large tan(beta)
in order to have experimentally acceptable masses for the top and bottom
quarks.
| [
{
"created": "Mon, 31 Mar 2003 09:37:03 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Prikas",
"A.",
"",
"National Technical University, Athens, Greece"
],
[
"Tracas",
"N. D.",
"",
"National Technical University, Athens, Greece"
]
] | We investigate the phase space of parameters in the Pati-Salam model derived in the context of D-branes scenarios, requiring low energy string scale. We find that a non-supersymmetric version complies with a string scale as low as 10 TeV, while in the supersymmetric version the string scale raises up to ~2 x 10^7 TeV. The limited energy region for RGE running demands a large tan(beta) in order to have experimentally acceptable masses for the top and bottom quarks. |
hep-ph/9611257 | Piotr Raczka | Piotr A. Raczka (Institute of Theoretical Physics, Warsaw University,
Warsaw, Poland) | Analysis of the renormalization scheme ambiguities in the QCD
corrections to hadronic decays of the tau lepton | 4 pages LateX, 2 figures in PostScript, uses stwol.sty and
epsfig.sty, to appear in the Proceedings of the 28th International Conference
on High Energy Physics, Warsaw, Poland, 25-31 July, 1996 | null | null | IFT-12/96 | hep-ph | null | The QCD corrections to the R_{\tau}^{12} moment of the invariant mass
distribution in hadronic decays of the tau lepton are discussed. The
next-to-next-to-leading order prediction is shown to be stable with respect to
change of the renormalization scheme, provided that the contour integral
expression is used. The optimized predictions are obtained using the principle
of minimal sensitivity to select the preferred renormalization scheme. The
optimized predictions for R_{\tau}^{12} and R_{\tau} are used in a simplified
fit to the experimental data to determine the strong coupling constant and the
parameter characterizing the nonperturbative contribution.
| [
{
"created": "Wed, 6 Nov 1996 18:12:44 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Raczka",
"Piotr A.",
"",
"Institute of Theoretical Physics, Warsaw University,\n Warsaw, Poland"
]
] | The QCD corrections to the R_{\tau}^{12} moment of the invariant mass distribution in hadronic decays of the tau lepton are discussed. The next-to-next-to-leading order prediction is shown to be stable with respect to change of the renormalization scheme, provided that the contour integral expression is used. The optimized predictions are obtained using the principle of minimal sensitivity to select the preferred renormalization scheme. The optimized predictions for R_{\tau}^{12} and R_{\tau} are used in a simplified fit to the experimental data to determine the strong coupling constant and the parameter characterizing the nonperturbative contribution. |
hep-ph/9712511 | Sergo Gerasimov | S.B.Gerasimov | On Electroweak Moments of Baryons and Spin-Flavour Structure of the
Nucleon | 8 pages, Latex, no figures, Talk given at the VII-th International
Workshop on High Energy Spin Physics, Dubna, 7-12 July 1997, to be published
in Proceedings | null | null | null | hep-ph | null | The phenomenological sum-rule-based approach is used to discuss the quark
composition dependence of some static and quasi-static electroweak
characteristics of nucleons.The role of nonvalence degrees of freedom, the
nucleon sea partons and/or peripheral meson currents, is shown to be important
to select and make use of the relevant symmetry parametrization of hadron
observables. With our preferable universal value of the SU(3)-symmetry
parameter $\alpha_{D}=D/F+D=.58$, taken for both magnetic moments and
axial-vector constants entering into the semi-leptonic baryon decays, we obtain
the following values for moments $\Delta q$ of the spin-dependent structure
function of the proton: $\Delta u \simeq .84(.82), \Delta d \simeq -.42(-.44),
\Delta s=-.22 \pm .05 (-.10 \pm .03)$, where the values in parentheses
correspond to the widely used "standard" value of $\alpha^{axial}_{D}=.63$. The
estimations of the strange sea contributions to the nucleon magnetic moments
and rms are also presented.
| [
{
"created": "Tue, 23 Dec 1997 17:45:32 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Gerasimov",
"S. B.",
""
]
] | The phenomenological sum-rule-based approach is used to discuss the quark composition dependence of some static and quasi-static electroweak characteristics of nucleons.The role of nonvalence degrees of freedom, the nucleon sea partons and/or peripheral meson currents, is shown to be important to select and make use of the relevant symmetry parametrization of hadron observables. With our preferable universal value of the SU(3)-symmetry parameter $\alpha_{D}=D/F+D=.58$, taken for both magnetic moments and axial-vector constants entering into the semi-leptonic baryon decays, we obtain the following values for moments $\Delta q$ of the spin-dependent structure function of the proton: $\Delta u \simeq .84(.82), \Delta d \simeq -.42(-.44), \Delta s=-.22 \pm .05 (-.10 \pm .03)$, where the values in parentheses correspond to the widely used "standard" value of $\alpha^{axial}_{D}=.63$. The estimations of the strange sea contributions to the nucleon magnetic moments and rms are also presented. |
hep-ph/9612285 | Georg Raffelt | Ara N. Ioannisian (Technion, Haifa), Georg G. Raffelt (MPI, Munich) | Cherenkov radiation by massless neutrinos in a magnetic field | 6 pages, REVTEX. Factor of 2 correction of final result. Reference
updates. To be published in Physical Review D | Phys. Rev. D 55, 7038 (1997) | 10.1103/PhysRevD.55.7038 | TECHNION-PH-96-23, MPI-PhT/96-126 | hep-ph astro-ph | null | We calculate the Cherenkov process nu -> nu+photon in the presence of a
homogeneous magnetic field. The neutrinos are taken to be massless with only
standard-model couplings. The magnetic field fulfills the dual purpose of
inducing an effective neutrino-photon vertex and of modifying the photon
dispersion relation such that the Cherenkov condition is fulfilled. Our effect
is closely related to photon splitting that occurs in magnetic fields and that
may be astrophysically important in the strong magnetic fields of pulsars. It
is also closely related to magnetic-field enhanced radiative decays nu ->
nu'+photon that have been extensively discussed in the recent literature. In
the appropriate limits we agree with these results, but we disagree with
earlier explicit calculations of the Cherenkov process. For a field strength
B_crit = m_e^2/e = 4.41E13 Gauss and for E=2m_e the Cherenkov rate is about
6E-11/sec and thus too small to be of practical importance for pulsar physics.
| [
{
"created": "Sun, 8 Dec 1996 12:15:07 GMT",
"version": "v1"
},
{
"created": "Tue, 18 Mar 1997 10:47:41 GMT",
"version": "v2"
}
] | 2016-08-24 | [
[
"Ioannisian",
"Ara N.",
"",
"Technion, Haifa"
],
[
"Raffelt",
"Georg G.",
"",
"MPI, Munich"
]
] | We calculate the Cherenkov process nu -> nu+photon in the presence of a homogeneous magnetic field. The neutrinos are taken to be massless with only standard-model couplings. The magnetic field fulfills the dual purpose of inducing an effective neutrino-photon vertex and of modifying the photon dispersion relation such that the Cherenkov condition is fulfilled. Our effect is closely related to photon splitting that occurs in magnetic fields and that may be astrophysically important in the strong magnetic fields of pulsars. It is also closely related to magnetic-field enhanced radiative decays nu -> nu'+photon that have been extensively discussed in the recent literature. In the appropriate limits we agree with these results, but we disagree with earlier explicit calculations of the Cherenkov process. For a field strength B_crit = m_e^2/e = 4.41E13 Gauss and for E=2m_e the Cherenkov rate is about 6E-11/sec and thus too small to be of practical importance for pulsar physics. |
hep-ph/0407029 | Leonard S. Kisslinger | Leonard S. Kisslinger (Carnegie Mellon University), Wei-hsing Ma
(CCAST (World Laboratory) and Institute of High Energy Physics, Academia
Sinica, Beijing, P. R. China), Pengnian Shen (CCAST (World Laboratory) and
Institute of High Energy Physics, Academia Sinica, Beijing, P. R. China) | Single and Double Peripheral Production of Sigmas in Proton Proton
Collisions | Revtex4 file, 8 Figures | Phys.Rev. D71 (2005) 094021 | 10.1103/PhysRevD.71.094021 | null | hep-ph | null | The Pomeron, which dominates high energy elastic and diffractive hadronic
processes, must be largely gluonic in nature. We use a recent picture of a
scalar glueball/sigma system with coupling of the sigma to glue determined from
experiment to predict strong peripheral sigma production in the pp$\pi^0\pi^0$
and double sigma production in the pp$\pi^0\pi^0\pi^0\pi^0$ channels.
| [
{
"created": "Fri, 2 Jul 2004 14:14:35 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Kisslinger",
"Leonard S.",
"",
"Carnegie Mellon University"
],
[
"Ma",
"Wei-hsing",
"",
"CCAST"
],
[
"Shen",
"Pengnian",
"",
"CCAST"
]
] | The Pomeron, which dominates high energy elastic and diffractive hadronic processes, must be largely gluonic in nature. We use a recent picture of a scalar glueball/sigma system with coupling of the sigma to glue determined from experiment to predict strong peripheral sigma production in the pp$\pi^0\pi^0$ and double sigma production in the pp$\pi^0\pi^0\pi^0\pi^0$ channels. |
1905.05640 | Stefan Scherer | Murray Moinester and Stefan Scherer | Compton Scattering off Pions and Electromagnetic Polarizabilities | 64 pages, 13 figures, preprint of a review article submitted for
consideration in International Journal of Modern Physics A \c{opyright}
[2019] [copyright World Scientific Publishing Company]
[https://www.worldscientific.com/worldscinet/ijmpa] | null | 10.1142/S0217751X19300084 | MITP/19-034 | hep-ph hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The electric ($\alpha_\pi$) and magnetic ($\beta_\pi$) Compton
polarizabilities of both the charged and the neutral pion are of fundamental
interest in the low-energy sector of quantum chromodynamics (QCD). Pion
polarizabilities affect the shape of the $\gamma\pi\to\gamma\pi$ Compton
scattering angular distribution at back scattering angles and
$\gamma\gamma\to\pi\pi$ absolute cross sections. Theory derivations are given
of the $\gamma\pi\to\gamma\pi$ Compton scattering differential cross section,
dispersion relations, and sum rules in terms of the polarizabilities. We review
experimental charged and neutral polarizability studies and theoretical
predictions. The $\pi^0$ polarizabilities were deduced from DESY Crystal Ball
$\gamma\gamma\to\pi^0\pi^0$ data, but with large uncertainties. The charged
pion polarizabilities were deduced most recently from (1) radiative pion
Primakoff scattering $\pi^- Z \to \pi^-Z\gamma$ at CERN COMPASS, (2) two-photon
pion pair production $\gamma\gamma\to\pi^+\pi^-$ at SLAC Mark II, and (3)
radiative pion photoproduction $\gamma p\to\gamma \pi^+ n$ from the proton at
MAMI in Mainz. A stringent test of chiral perturbation theory (ChPT) is
possible based on comparisons of precision experimental charged pion
polarizabilities with ChPT predictions. Only the CERN COMPASS charged pion
polarizability measurement has acceptably small uncertainties. Its value
$\alpha_{\pi^\pm}-\beta_{\pi^\pm} = (4.0\pm 1.8)\times 10^{-4}\,\text{fm}^3$
agrees well with the two-loop ChPT prediction
$\alpha_{\pi^\pm}-\beta_{\pi^\pm}=(5.7\pm 1.0)\times 10^{-4}\,\text{fm}^3$,
strengthening the identification of the pion with the Goldstone boson of chiral
symmetry breaking in QCD.
| [
{
"created": "Tue, 14 May 2019 14:29:32 GMT",
"version": "v1"
}
] | 2019-06-26 | [
[
"Moinester",
"Murray",
""
],
[
"Scherer",
"Stefan",
""
]
] | The electric ($\alpha_\pi$) and magnetic ($\beta_\pi$) Compton polarizabilities of both the charged and the neutral pion are of fundamental interest in the low-energy sector of quantum chromodynamics (QCD). Pion polarizabilities affect the shape of the $\gamma\pi\to\gamma\pi$ Compton scattering angular distribution at back scattering angles and $\gamma\gamma\to\pi\pi$ absolute cross sections. Theory derivations are given of the $\gamma\pi\to\gamma\pi$ Compton scattering differential cross section, dispersion relations, and sum rules in terms of the polarizabilities. We review experimental charged and neutral polarizability studies and theoretical predictions. The $\pi^0$ polarizabilities were deduced from DESY Crystal Ball $\gamma\gamma\to\pi^0\pi^0$ data, but with large uncertainties. The charged pion polarizabilities were deduced most recently from (1) radiative pion Primakoff scattering $\pi^- Z \to \pi^-Z\gamma$ at CERN COMPASS, (2) two-photon pion pair production $\gamma\gamma\to\pi^+\pi^-$ at SLAC Mark II, and (3) radiative pion photoproduction $\gamma p\to\gamma \pi^+ n$ from the proton at MAMI in Mainz. A stringent test of chiral perturbation theory (ChPT) is possible based on comparisons of precision experimental charged pion polarizabilities with ChPT predictions. Only the CERN COMPASS charged pion polarizability measurement has acceptably small uncertainties. Its value $\alpha_{\pi^\pm}-\beta_{\pi^\pm} = (4.0\pm 1.8)\times 10^{-4}\,\text{fm}^3$ agrees well with the two-loop ChPT prediction $\alpha_{\pi^\pm}-\beta_{\pi^\pm}=(5.7\pm 1.0)\times 10^{-4}\,\text{fm}^3$, strengthening the identification of the pion with the Goldstone boson of chiral symmetry breaking in QCD. |
1209.4610 | Kuang-Ta Chao | Hua-Sheng Shao, Kuang-Ta Chao | Spin correlations in polarizations of P-wave charmonia $\chi_{cJ}$ and
impact on $J/\psi$ polarization | Version published in PRD, 23 pages, 18 figures | Phys. Rev. D 90, 014002 (2014) | 10.1103/PhysRevD.90.014002 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Based on a general form of the effective vertex functions for the decays of
P-wave charmonia $\chicj$, angular distribution formulas for the subsequent
decays $\chicj\rightarrow \jpsi \gamma$ and $\jpsi \to \mu^+\mu^-$ are derived.
The formulas are the same as those obtained in a different approach in the
literature. Our formulas are expressed in a more general form, including parity
violation effects and the full angular dependence of $\jpsi$ and muon in the
cascade decay $\chicj\to\jpsi\gamma\to\mu^+\mu^-\gamma$. The $\chicj$
polarization observables are expressed in terms of rational functions of the
spin density matrix elements of $\chicj$ production. Generalized
rotation-invariant relations for arbitrary integer-spin particles are also
derived and their expressions in terms of observable angular distribution
parameters are given in the $\chi_{c1}$ and $\chi_{c2}$. To complement our
previous direct-$\jpsi$ polarization result, we also discuss the impact on the
observable prompt-$\jpsi$ polarization. As an illustrative application of our
angular distribution formulas, we present the angular distributions in terms of
the tree-level spin density matrix elements of $\chi_{c1}$ and $\chi_{c2}$
production in several different frames at the Large Hadron Collider. Moreover,
a reweighting method is also proposed to determine the entire set of the
production spin density matrix elements of the $\chi_{c2}$, some of which
disappear or are suppressed for vanishing higher-order multipole effects making
the complete extraction difficult experimentally.
| [
{
"created": "Thu, 20 Sep 2012 18:57:39 GMT",
"version": "v1"
},
{
"created": "Wed, 2 Jul 2014 05:58:17 GMT",
"version": "v2"
}
] | 2014-07-09 | [
[
"Shao",
"Hua-Sheng",
""
],
[
"Chao",
"Kuang-Ta",
""
]
] | Based on a general form of the effective vertex functions for the decays of P-wave charmonia $\chicj$, angular distribution formulas for the subsequent decays $\chicj\rightarrow \jpsi \gamma$ and $\jpsi \to \mu^+\mu^-$ are derived. The formulas are the same as those obtained in a different approach in the literature. Our formulas are expressed in a more general form, including parity violation effects and the full angular dependence of $\jpsi$ and muon in the cascade decay $\chicj\to\jpsi\gamma\to\mu^+\mu^-\gamma$. The $\chicj$ polarization observables are expressed in terms of rational functions of the spin density matrix elements of $\chicj$ production. Generalized rotation-invariant relations for arbitrary integer-spin particles are also derived and their expressions in terms of observable angular distribution parameters are given in the $\chi_{c1}$ and $\chi_{c2}$. To complement our previous direct-$\jpsi$ polarization result, we also discuss the impact on the observable prompt-$\jpsi$ polarization. As an illustrative application of our angular distribution formulas, we present the angular distributions in terms of the tree-level spin density matrix elements of $\chi_{c1}$ and $\chi_{c2}$ production in several different frames at the Large Hadron Collider. Moreover, a reweighting method is also proposed to determine the entire set of the production spin density matrix elements of the $\chi_{c2}$, some of which disappear or are suppressed for vanishing higher-order multipole effects making the complete extraction difficult experimentally. |
2308.02697 | Subhadeep Sarkar | Arghya Choudhury, Arpita Mondal, Subhadeep Mondal and Subhadeep Sarkar | Improving sensitivity of trilinear RPV SUSY searches using machine
learning at the LHC | 37 pages, 10 figures, 13 tables | null | null | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | In this work, we have explored the sensitivity of multilepton final states in
probing the gaugino sector of R-parity violating supersymmetric scenario with
specific lepton number violating trilinear couplings ($\lambda_{ijk}$) being
non-zero. The gaugino spectrum is such that the charged leptons in the final
state can arise from the R-parity violating decays of the lightest
supersymmetric particle (LSP) as well as R-parity conserving decays of the
next-to-LSP (NLSP). Apart from a detailed cut-based analysis, we have also
performed a machine learning-based analysis using boosted decision tree
algorithm which provides much better sensitivity. In the scenarios with
non-zero $\lambda_{121}$ and/or $\lambda_{122}$ couplings, the LSP pair in the
final states decays to $4l~(l = e, \mu) + \rm E{\!\!\!/}_T$ final states with
$100\%$ branching ratio. We have shown that under this circumstance, a final
state with $\ge 4l$ has the highest sensitivity in probing the gaugino masses.
We also discuss how the sensitivity can change in the presence of $\tau$
lepton(s) in the final state due to other choices of trilinear couplings. We
present our results through the estimation of the discovery and exclusion
contours in the gaugino mass plane for both the HL-LHC and the HE-LHC. For
$\lambda_{121}$ and/or $\lambda_{122}$ nonzero scenario, the projected
2$\sigma$ exclusion limit on NLSP masses reaches upto 2.37 TeV and 4 TeV for
the HL-LHC and the HE-LHC respectively by using a machine learning based
algorithm. We obtain an enhancement of $\sim$ 380 (190) GeV in the projected
2$\sigma$ exclusion limit on the NLSP masses at the 27 (14) TeV LHC.
Considering the same final state ($N_l \geq 4$) for $\lambda_{133}$ and/or
$\lambda_{233}$ non-zero scenario, we find that the corresponding 2$\sigma$
projected limits are $\sim$ 1.97 TeV and $\sim$ 3.25 TeV for the HL-LHC and
HE-LHC respectively.
| [
{
"created": "Fri, 4 Aug 2023 20:23:34 GMT",
"version": "v1"
}
] | 2023-08-08 | [
[
"Choudhury",
"Arghya",
""
],
[
"Mondal",
"Arpita",
""
],
[
"Mondal",
"Subhadeep",
""
],
[
"Sarkar",
"Subhadeep",
""
]
] | In this work, we have explored the sensitivity of multilepton final states in probing the gaugino sector of R-parity violating supersymmetric scenario with specific lepton number violating trilinear couplings ($\lambda_{ijk}$) being non-zero. The gaugino spectrum is such that the charged leptons in the final state can arise from the R-parity violating decays of the lightest supersymmetric particle (LSP) as well as R-parity conserving decays of the next-to-LSP (NLSP). Apart from a detailed cut-based analysis, we have also performed a machine learning-based analysis using boosted decision tree algorithm which provides much better sensitivity. In the scenarios with non-zero $\lambda_{121}$ and/or $\lambda_{122}$ couplings, the LSP pair in the final states decays to $4l~(l = e, \mu) + \rm E{\!\!\!/}_T$ final states with $100\%$ branching ratio. We have shown that under this circumstance, a final state with $\ge 4l$ has the highest sensitivity in probing the gaugino masses. We also discuss how the sensitivity can change in the presence of $\tau$ lepton(s) in the final state due to other choices of trilinear couplings. We present our results through the estimation of the discovery and exclusion contours in the gaugino mass plane for both the HL-LHC and the HE-LHC. For $\lambda_{121}$ and/or $\lambda_{122}$ nonzero scenario, the projected 2$\sigma$ exclusion limit on NLSP masses reaches upto 2.37 TeV and 4 TeV for the HL-LHC and the HE-LHC respectively by using a machine learning based algorithm. We obtain an enhancement of $\sim$ 380 (190) GeV in the projected 2$\sigma$ exclusion limit on the NLSP masses at the 27 (14) TeV LHC. Considering the same final state ($N_l \geq 4$) for $\lambda_{133}$ and/or $\lambda_{233}$ non-zero scenario, we find that the corresponding 2$\sigma$ projected limits are $\sim$ 1.97 TeV and $\sim$ 3.25 TeV for the HL-LHC and HE-LHC respectively. |
1111.0238 | Alexander Semke | A. Semke and M. F. M. Lutz | On the quark-mass dependence of the baryon ground-state masses | 22 pages, 3 figures, 3 tables. 2nd version: typos corrected, wording
adjusted according to the journal style, figures improved and corrected | null | 10.1103/PhysRevD.85.034001 | null | hep-ph hep-lat | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We perform a chiral extrapolation of the baryon octet and decuplet masses in
a relativistic formulation of chiral perturbation theory. A partial summation
is assumed as implied by the use of physical baryon and meson masses in the
one-loop diagrams. Upon a chiral expansion, our results are consistent with
strict chiral perturbation theory at the next-to-next-to-next-to-leading order.
All counter terms are correlated by a large-$N_c$ operator analysis. Our
results are confronted with recent results of unquenched three-flavor lattice
simulations. We adjust the parameter set to the pion-mass dependence of the
nucleon and omega masses as computed by the BMW Collaboration and predict the
pion-mass dependence of the remaining baryon octet and decuplet states. The
current lattice simulations can be described accurately and smoothly up to pion
masses of about 600 MeV. In particular, we recover the recent results of HSC
without any further adjustments.
| [
{
"created": "Tue, 1 Nov 2011 16:46:35 GMT",
"version": "v1"
},
{
"created": "Sat, 4 Feb 2012 10:54:41 GMT",
"version": "v2"
}
] | 2015-06-03 | [
[
"Semke",
"A.",
""
],
[
"Lutz",
"M. F. M.",
""
]
] | We perform a chiral extrapolation of the baryon octet and decuplet masses in a relativistic formulation of chiral perturbation theory. A partial summation is assumed as implied by the use of physical baryon and meson masses in the one-loop diagrams. Upon a chiral expansion, our results are consistent with strict chiral perturbation theory at the next-to-next-to-next-to-leading order. All counter terms are correlated by a large-$N_c$ operator analysis. Our results are confronted with recent results of unquenched three-flavor lattice simulations. We adjust the parameter set to the pion-mass dependence of the nucleon and omega masses as computed by the BMW Collaboration and predict the pion-mass dependence of the remaining baryon octet and decuplet states. The current lattice simulations can be described accurately and smoothly up to pion masses of about 600 MeV. In particular, we recover the recent results of HSC without any further adjustments. |
0806.4317 | Douglas Shaw | John D. Barrow, Douglas J. Shaw | Varying Alpha: New Constraints from Seasonal Variations | 4 pages, 1 figure | Phys.Rev.D78:067304,2008 | 10.1103/PhysRevD.78.067304 | null | hep-ph astro-ph gr-qc | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We analyse the constraints obtained from new atomic clock data on the
possible time variation of the fine structure `constant' and the
electron-proton mass ratio and show how they are strengthened when the seasonal
variation of Sun's gravitational field at the Earth's surface is taken into
account. We compare these bounds with those obtainable from tests of the Weak
Equivalence Principle and high-redshift observations of quasar absorption
spectra consistent with time variations in the fine structure constant.
| [
{
"created": "Thu, 26 Jun 2008 14:18:23 GMT",
"version": "v1"
},
{
"created": "Mon, 13 Oct 2008 16:10:13 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Barrow",
"John D.",
""
],
[
"Shaw",
"Douglas J.",
""
]
] | We analyse the constraints obtained from new atomic clock data on the possible time variation of the fine structure `constant' and the electron-proton mass ratio and show how they are strengthened when the seasonal variation of Sun's gravitational field at the Earth's surface is taken into account. We compare these bounds with those obtainable from tests of the Weak Equivalence Principle and high-redshift observations of quasar absorption spectra consistent with time variations in the fine structure constant. |
hep-ph/0108037 | Ulrich Nierste | A. Dedes, H.K. Dreiner and U. Nierste | Correlation of B_s -> mu^+ mu^- and (g-2)_mu in Minimal Supergravity | bug in numerics (affecting the figs.) fixed, discussion of A_0<>0
added, accepted by PRL | Phys.Rev.Lett.87:251804,2001 | 10.1103/PhysRevLett.87.251804 | CERN-TH/2001-211 | hep-ph | null | We analyse the rare decay mode B_s -> mu^+ mu^- in the minimal supergravity
scenario (mSUGRA). We find a strong correlation with the muon anomalous
magnetic moment (g-2)_mu. An interpretation of the recently measured excess in
(g-2)_mu in terms of mSUGRA corrections implies a substantial supersymmetric
enhancement of the branching ratio Br(B_s -> mu^+ mu^-): if (g-2)_mu exceeds
the Standard Model prediction by 4*10^{-9}, Br(B_s -> mu^+ mu^-) is larger by a
factor of 10-100 than in the Standard Model and within reach of Run-II of the
Tevatron. Thus an experimental search for B_s -> mu^+ mu^- is a stringent test
of the mSUGRA GUT scale boundary conditions. If the decay B_s -> mu^+ mu^- is
observed at Run-II of the Tevatron, then we predict the mass of the lightest
supersymmetric Higgs boson to be less than 120 GeV. The decay B_s -> mu^+ mu^-
can also significantly probe the favoured parameter range in SO(10) SUSY GUT
models.
| [
{
"created": "Fri, 3 Aug 2001 15:21:34 GMT",
"version": "v1"
},
{
"created": "Fri, 24 Aug 2001 17:47:04 GMT",
"version": "v2"
},
{
"created": "Sun, 28 Oct 2001 15:43:53 GMT",
"version": "v3"
}
] | 2011-03-23 | [
[
"Dedes",
"A.",
""
],
[
"Dreiner",
"H. K.",
""
],
[
"Nierste",
"U.",
""
]
] | We analyse the rare decay mode B_s -> mu^+ mu^- in the minimal supergravity scenario (mSUGRA). We find a strong correlation with the muon anomalous magnetic moment (g-2)_mu. An interpretation of the recently measured excess in (g-2)_mu in terms of mSUGRA corrections implies a substantial supersymmetric enhancement of the branching ratio Br(B_s -> mu^+ mu^-): if (g-2)_mu exceeds the Standard Model prediction by 4*10^{-9}, Br(B_s -> mu^+ mu^-) is larger by a factor of 10-100 than in the Standard Model and within reach of Run-II of the Tevatron. Thus an experimental search for B_s -> mu^+ mu^- is a stringent test of the mSUGRA GUT scale boundary conditions. If the decay B_s -> mu^+ mu^- is observed at Run-II of the Tevatron, then we predict the mass of the lightest supersymmetric Higgs boson to be less than 120 GeV. The decay B_s -> mu^+ mu^- can also significantly probe the favoured parameter range in SO(10) SUSY GUT models. |
2012.06595 | Matteo Maltoni | Celine Degrande, Matteo Maltoni | Reviving the interference: framework and proof-of-principle for the
anomalous gluon self-interaction in the SMEFT | 5 pages, 4 figures | Phys. Rev. D 103, 095009 (2021) | 10.1103/PhysRevD.103.095009 | CP3-20-58 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Interferences are not positive-definite and therefore they can change sign
over the phase space. If the contributions of the regions where the
interference is positive and negative nearly cancel each other, interference
effects are hard to measure. In this paper, we propose a method to quantify the
ability of an observable to separate an interference positive and negative
contributions and therefore to revive the interference effects in measurements.
We apply this method to the anomalous gluon operator in the SMEFT for which the
interference suppression is well-known. We show that we can get contraints on
its coefficient, using the interference only, similar to those obtained by
including the square of the new physics amplitude.
| [
{
"created": "Fri, 11 Dec 2020 19:01:05 GMT",
"version": "v1"
}
] | 2021-05-19 | [
[
"Degrande",
"Celine",
""
],
[
"Maltoni",
"Matteo",
""
]
] | Interferences are not positive-definite and therefore they can change sign over the phase space. If the contributions of the regions where the interference is positive and negative nearly cancel each other, interference effects are hard to measure. In this paper, we propose a method to quantify the ability of an observable to separate an interference positive and negative contributions and therefore to revive the interference effects in measurements. We apply this method to the anomalous gluon operator in the SMEFT for which the interference suppression is well-known. We show that we can get contraints on its coefficient, using the interference only, similar to those obtained by including the square of the new physics amplitude. |
2407.09614 | Sven Fabian | Subhaditya Bhattacharya, Sven Fabian, Johannes Herms, Sudip Jana | Flavor-Specific Dark Matter Signatures through the Lens of Neutrino
Oscillations | 34 pages, 13 figures, 6 tables | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We investigate the flavor-specific properties of leptophilic dark matter in
neutrino mass models, where dark matter signals are directly correlated with
the neutrino oscillation data, providing complementary insights into the
neutrino mass hierarchy and CP phases. Notably, this can be accomplished
without introducing a flavor-specific portal to dark matter, imposing any new
flavor symmetry, or involving flavon fields. As a case study, we analyze the
correlation between the flavor-philic nature of dark matter and neutrino
oscillation data in the type-II seesaw and Zee-Babu models, and extend this
discussion to other neutrino mass models. We analyze the indirect signatures of
such leptophilic dark matter, specifically examining the spectrum of the cosmic
ray electron/positron flux resulting from the pair annihilation of dark matter
in the Galactic halo, and explore correlated lepton-specific signals at
collider experiments sensitive to neutrino oscillation data.
| [
{
"created": "Fri, 12 Jul 2024 18:00:50 GMT",
"version": "v1"
}
] | 2024-07-16 | [
[
"Bhattacharya",
"Subhaditya",
""
],
[
"Fabian",
"Sven",
""
],
[
"Herms",
"Johannes",
""
],
[
"Jana",
"Sudip",
""
]
] | We investigate the flavor-specific properties of leptophilic dark matter in neutrino mass models, where dark matter signals are directly correlated with the neutrino oscillation data, providing complementary insights into the neutrino mass hierarchy and CP phases. Notably, this can be accomplished without introducing a flavor-specific portal to dark matter, imposing any new flavor symmetry, or involving flavon fields. As a case study, we analyze the correlation between the flavor-philic nature of dark matter and neutrino oscillation data in the type-II seesaw and Zee-Babu models, and extend this discussion to other neutrino mass models. We analyze the indirect signatures of such leptophilic dark matter, specifically examining the spectrum of the cosmic ray electron/positron flux resulting from the pair annihilation of dark matter in the Galactic halo, and explore correlated lepton-specific signals at collider experiments sensitive to neutrino oscillation data. |
hep-ph/0606074 | Leonid Satarov | L.M. Satarov, I.N. Mishustin, A.V. Merdeev, and H. Stoecker | Longitudinal fluid dynamics for ultrarelativistic heavy-ion collisions | 22 pages, 8 figures; 4 figures and 12 references added | Phys.Rev.C75:024903,2007 | 10.1103/PhysRevC.75.024903 | null | hep-ph | null | We develop a 1+1 dimensional hydrodynamical model for central heavy-ion
collisions at ultrarelativistic energies. Deviations from Bjorken's scaling are
taken into account by implementing finite-size profiles for the initial energy
density. The calculated rapidity distributions of pions, kaons and antiprotons
in central Au+Au collisions at the c.m. energy 200 AGeV are compared with
experimental data of the BRAHMS Collaboration. The sensitivity of the results
to the choice of the equation of state, the parameters of initial state and the
freeze-out conditions is investigated. Experimental constraints on the total
energy of produced particles are used to reduce the number of model parameters.
The best fits of experimental data are obtained for soft equations of state and
Gaussian-like initial profiles of the energy density. It is found that initial
energy densities required for fitting experimental data decrease with
increasing critical temperature of the phase transition.
| [
{
"created": "Wed, 7 Jun 2006 09:36:02 GMT",
"version": "v1"
},
{
"created": "Fri, 22 Jun 2007 09:18:24 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Satarov",
"L. M.",
""
],
[
"Mishustin",
"I. N.",
""
],
[
"Merdeev",
"A. V.",
""
],
[
"Stoecker",
"H.",
""
]
] | We develop a 1+1 dimensional hydrodynamical model for central heavy-ion collisions at ultrarelativistic energies. Deviations from Bjorken's scaling are taken into account by implementing finite-size profiles for the initial energy density. The calculated rapidity distributions of pions, kaons and antiprotons in central Au+Au collisions at the c.m. energy 200 AGeV are compared with experimental data of the BRAHMS Collaboration. The sensitivity of the results to the choice of the equation of state, the parameters of initial state and the freeze-out conditions is investigated. Experimental constraints on the total energy of produced particles are used to reduce the number of model parameters. The best fits of experimental data are obtained for soft equations of state and Gaussian-like initial profiles of the energy density. It is found that initial energy densities required for fitting experimental data decrease with increasing critical temperature of the phase transition. |
1111.4008 | Antonio Delgado | Antonio Delgado, Christopher Kolda and Alejandro de la Puente | Solving the Hierarchy Problem with a Light Singlet and Supersymmetric
Mass Terms | 14 pages, 4 figures | null | 10.1016/j.physletb.2012.03.034 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A generalization of the Next-to-Minimal Supersymmetric Model (NMSSM) is
studied in which an explicit \mu-term as well as a small supersymmetric mass
term for the singlet superfield are incorporated. We study the possibility of
raising the Standard Model-like Higgs mass at tree level through its mixing
with a light, mostly-singlet, CP-even scalar. We are able to generate Higgs
boson masses up to 145 GeV with top squarks below 1.1 TeV and without the need
to fine tune parameters in the scalar potential. This model yields light
singlet-like scalars and pseudoscalars passing all collider constraints.
| [
{
"created": "Thu, 17 Nov 2011 02:25:08 GMT",
"version": "v1"
}
] | 2015-06-03 | [
[
"Delgado",
"Antonio",
""
],
[
"Kolda",
"Christopher",
""
],
[
"de la Puente",
"Alejandro",
""
]
] | A generalization of the Next-to-Minimal Supersymmetric Model (NMSSM) is studied in which an explicit \mu-term as well as a small supersymmetric mass term for the singlet superfield are incorporated. We study the possibility of raising the Standard Model-like Higgs mass at tree level through its mixing with a light, mostly-singlet, CP-even scalar. We are able to generate Higgs boson masses up to 145 GeV with top squarks below 1.1 TeV and without the need to fine tune parameters in the scalar potential. This model yields light singlet-like scalars and pseudoscalars passing all collider constraints. |
1703.08125 | Triparno Bandyopadhyay | Triparno Bandyopadhyay (Calcutta Univ.) and Amitava Raychaudhuri
(Calcutta Univ.) | Left-right model with TeV fermionic dark matter and unification | Published version. 11 Pages, 4 figures. More details provided for
unification of gauge couplings and for proton decay lifetime estimate.
References added | Phys. Lett. B 771 (2017) 206 | 10.1016/j.physletb.2017.05.042 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The ingredients for a model with a TeV right-handed scale, gauge coupling
unification, and suitable dark matter candidates lie at the heart of left-right
symmetry with broken D-parity. After detailing the contents of such a model,
with SU(2)R self-conjugate fermions at the right-handed scale aiding in
unification of couplings, we explore its dark matter implications and collider
signatures.
| [
{
"created": "Thu, 23 Mar 2017 16:12:24 GMT",
"version": "v1"
},
{
"created": "Fri, 24 Mar 2017 17:47:34 GMT",
"version": "v2"
},
{
"created": "Fri, 2 Jun 2017 17:53:28 GMT",
"version": "v3"
}
] | 2017-06-05 | [
[
"Bandyopadhyay",
"Triparno",
"",
"Calcutta Univ."
],
[
"Raychaudhuri",
"Amitava",
"",
"Calcutta Univ."
]
] | The ingredients for a model with a TeV right-handed scale, gauge coupling unification, and suitable dark matter candidates lie at the heart of left-right symmetry with broken D-parity. After detailing the contents of such a model, with SU(2)R self-conjugate fermions at the right-handed scale aiding in unification of couplings, we explore its dark matter implications and collider signatures. |
1011.0704 | Joerg Jaeckel | Joerg Jaeckel | Low energy laboratory searches for WISPs | 9 pages, 2 figures, contributed to the proceedings of "The 6th Patras
Workshop on Axions, WIMPs and WISPs", Zurich, Switzerland, 5-9 Jul 2010 | null | null | IPPP/10/91; DCPT/10/182 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present an overview over the current status of laboratory experiments
searching for (very) weakly coupled slim particles (WISPs). These experiments
at the high precision frontier explore new physics beyond the standard model in
a complementary way to high energy accelerators. The multitude of active and
planned experiments shows a lively field and promises interesting new data in
the near future.
| [
{
"created": "Tue, 2 Nov 2010 18:57:12 GMT",
"version": "v1"
}
] | 2010-11-03 | [
[
"Jaeckel",
"Joerg",
""
]
] | We present an overview over the current status of laboratory experiments searching for (very) weakly coupled slim particles (WISPs). These experiments at the high precision frontier explore new physics beyond the standard model in a complementary way to high energy accelerators. The multitude of active and planned experiments shows a lively field and promises interesting new data in the near future. |
hep-ph/0501245 | Stenzel Hasko | H.Stenzel | Theoretical uncertainties for measurements of alpha_s from electroweak
observables | v4: Revised version with new tables and figures | JHEP0507:0132,2005 | 10.1088/1126-6708/2005/07/013 | null | hep-ph | null | One of the most precise measurements of the strong coupling constant
alpha_s(MZ) is obtained in the context of global analyses of precision
electroweak data. This article reviews the sensitivity of different electroweak
observables to alpha_s and describes the perturbative uncertainties related to
missing higher orders. The complete renormalisation scale dependence for the
relevant observables is calculated at next-to-next-to-leading order and a new
method is presented to determine the corresponding perturbative uncertainty for
measurements of alpha_s based on these observables.
| [
{
"created": "Wed, 26 Jan 2005 16:39:08 GMT",
"version": "v1"
},
{
"created": "Thu, 27 Jan 2005 16:25:47 GMT",
"version": "v2"
},
{
"created": "Thu, 24 Feb 2005 09:29:13 GMT",
"version": "v3"
},
{
"created": "Fri, 20 May 2005 13:03:50 GMT",
"version": "v4"
}
] | 2009-11-11 | [
[
"Stenzel",
"H.",
""
]
] | One of the most precise measurements of the strong coupling constant alpha_s(MZ) is obtained in the context of global analyses of precision electroweak data. This article reviews the sensitivity of different electroweak observables to alpha_s and describes the perturbative uncertainties related to missing higher orders. The complete renormalisation scale dependence for the relevant observables is calculated at next-to-next-to-leading order and a new method is presented to determine the corresponding perturbative uncertainty for measurements of alpha_s based on these observables. |
hep-ph/9203206 | null | R. Holman, S.D.H. Hsu, T. Kephart, E. Kolb, R. Watkins and L. Widrow | Solutions to the strong CP problem in a world with gravity | 10 pages | Phys.Lett.B282:132-136,1992 | 10.1016/0370-2693(92)90491-L | null | hep-ph | null | We examine the sensitivity of several solutions of the strong-CP problem to
violations of global symmetries by Planck scale physics. We find that the
Peccei-Quinn solution is extremely sensitive to U(1)_PQ violating operators of
dimension less than 10. We construct models in which the PQ symmetry is
protected by gauge symmetries to the requisite level.
| [
{
"created": "Mon, 9 Mar 1992 19:44:08 GMT",
"version": "v1"
}
] | 2010-11-01 | [
[
"Holman",
"R.",
""
],
[
"Hsu",
"S. D. H.",
""
],
[
"Kephart",
"T.",
""
],
[
"Kolb",
"E.",
""
],
[
"Watkins",
"R.",
""
],
[
"Widrow",
"L.",
""
]
] | We examine the sensitivity of several solutions of the strong-CP problem to violations of global symmetries by Planck scale physics. We find that the Peccei-Quinn solution is extremely sensitive to U(1)_PQ violating operators of dimension less than 10. We construct models in which the PQ symmetry is protected by gauge symmetries to the requisite level. |
hep-ph/9208201 | null | M. Jamin, M. Muenz | Current correlators to all orders in the quark masses | 24 pages, LateX file, TUM-T31-21/92, 1 postscript file included | Z.Phys. C60 (1993) 569-578 | 10.1007/BF01560056 | null | hep-ph | null | The contributions to the coefficient functions of the quark and the mixed
quark-gluon condensate to mesonic correlators are calculated for the first time
to all orders in the quark masses, and to lowest order in the strong coupling
constant. Existing results on the coefficient functions of the unit operator
and the gluon condensate are reviewed. The proper factorization of short- and
long-distance contributions in the operator product expansion is discussed in
detail. It is found that to accomplish this task rigorously the operator
product expansion has to be performed in terms of non-normal-ordered
condensates. The resulting coefficient functions are improved with the help of
the renormalization group. The scale invariant combination of dimension 5
operators, including mixing with the mass operator, which is needed for the
renormalization group improvement, is calculated in the leading order.
| [
{
"created": "Mon, 3 Aug 1992 16:42:37 GMT",
"version": "v1"
}
] | 2009-10-22 | [
[
"Jamin",
"M.",
""
],
[
"Muenz",
"M.",
""
]
] | The contributions to the coefficient functions of the quark and the mixed quark-gluon condensate to mesonic correlators are calculated for the first time to all orders in the quark masses, and to lowest order in the strong coupling constant. Existing results on the coefficient functions of the unit operator and the gluon condensate are reviewed. The proper factorization of short- and long-distance contributions in the operator product expansion is discussed in detail. It is found that to accomplish this task rigorously the operator product expansion has to be performed in terms of non-normal-ordered condensates. The resulting coefficient functions are improved with the help of the renormalization group. The scale invariant combination of dimension 5 operators, including mixing with the mass operator, which is needed for the renormalization group improvement, is calculated in the leading order. |
hep-ph/9505326 | Steve King | S. F. King and P. L. White | Resolving the Constrained Minimal and Next-to-Minimal Supersymmetric
Standard Models | 76 pages, latex, no macros, uuencoded figures included separately.
This version (to appear in Phys. Rev. D) contains various minor changes | Phys. Rev. D 52, 4183 (1995) | 10.1103/PhysRevD.52.4183 | SHEP 95-17, OUTP-9519P | hep-ph | null | We perform a detailed analysis of the next-to-minimal supersymmetric standard
model (NMSSM), imposing the constraints of two-loop gauge coupling unification,
universal soft supersymmetry breaking and the correct pattern of electroweak
symmetry breaking. We compare our results with those for the minimal
supersymmetric standard model (MSSM) using closely related techniques and, as
far as possible, a common set of input and output variables. In general, in the
constrained NMSSM, there are much stronger correlations between parameters than
in the constrained MSSM, and we map out the allowed parameter space. We also
give a detailed discussion of how to resolve the two models experimentally,
concentrating primarily on the prospects at LEPII.
| [
{
"created": "Wed, 17 May 1995 11:21:04 GMT",
"version": "v1"
},
{
"created": "Thu, 5 Oct 1995 15:52:42 GMT",
"version": "v2"
},
{
"created": "Fri, 6 Oct 1995 11:13:07 GMT",
"version": "v3"
}
] | 2016-08-24 | [
[
"King",
"S. F.",
""
],
[
"White",
"P. L.",
""
]
] | We perform a detailed analysis of the next-to-minimal supersymmetric standard model (NMSSM), imposing the constraints of two-loop gauge coupling unification, universal soft supersymmetry breaking and the correct pattern of electroweak symmetry breaking. We compare our results with those for the minimal supersymmetric standard model (MSSM) using closely related techniques and, as far as possible, a common set of input and output variables. In general, in the constrained NMSSM, there are much stronger correlations between parameters than in the constrained MSSM, and we map out the allowed parameter space. We also give a detailed discussion of how to resolve the two models experimentally, concentrating primarily on the prospects at LEPII. |
2106.00238 | Shi Pu | Cong Yi, Shi Pu and Di-Lun Yang | Reexamination of local spin polarization beyond global equilibrium in
relativistic heavy ion collisions | 22 pages, 5 figures; matched the journal version, typos for T in
Fig.3 corrected | null | 10.1103/PhysRevC.104.064901 | null | hep-ph nucl-th | http://creativecommons.org/licenses/by/4.0/ | We study local spin polarization in the relativistic hydrodynamic model.
Generalizing the Wigner functions previously obtained from chiral kinetic
theory by Y. Hidaka et al. [Phys. Rev. D 97, 016004 (2018)] to the massive
case, we present the possible contributions up to the order of $\hbar$ from
thermal vorticity, shear viscous tensor, other terms associated with the
temperature and chemical-potential gradients, and electromagnetic fields to the
local spin polarization. We then implement the (3+1)-dimensional viscous
hydrodynamic model to study the spin polarizations from these sources with a
small chemical potential and ignorance of electromagnetic fields by adopting an
equation of state different from those in other recent studies. Although the
shear correction alone upon the local polarization results in a sign and
azimuthal-angle dependence more consistent with experimental observations, as
also discovered in other recent studies, it is mostly suppressed by the
contributions from thermal vorticity and other terms that yield an opposite
trend. It is found that the total local spin polarization can be very sensitive
to the equation of states, the ratio of shear viscosity to entropy density, and
the freeze-out temperature.
| [
{
"created": "Tue, 1 Jun 2021 05:30:47 GMT",
"version": "v1"
},
{
"created": "Wed, 9 Jun 2021 07:20:04 GMT",
"version": "v2"
},
{
"created": "Fri, 24 Dec 2021 07:41:06 GMT",
"version": "v3"
}
] | 2021-12-28 | [
[
"Yi",
"Cong",
""
],
[
"Pu",
"Shi",
""
],
[
"Yang",
"Di-Lun",
""
]
] | We study local spin polarization in the relativistic hydrodynamic model. Generalizing the Wigner functions previously obtained from chiral kinetic theory by Y. Hidaka et al. [Phys. Rev. D 97, 016004 (2018)] to the massive case, we present the possible contributions up to the order of $\hbar$ from thermal vorticity, shear viscous tensor, other terms associated with the temperature and chemical-potential gradients, and electromagnetic fields to the local spin polarization. We then implement the (3+1)-dimensional viscous hydrodynamic model to study the spin polarizations from these sources with a small chemical potential and ignorance of electromagnetic fields by adopting an equation of state different from those in other recent studies. Although the shear correction alone upon the local polarization results in a sign and azimuthal-angle dependence more consistent with experimental observations, as also discovered in other recent studies, it is mostly suppressed by the contributions from thermal vorticity and other terms that yield an opposite trend. It is found that the total local spin polarization can be very sensitive to the equation of states, the ratio of shear viscosity to entropy density, and the freeze-out temperature. |
hep-ph/0702112 | Bhaskar Dutta | Rouzbeh Allahverdi, Bhaskar Dutta, Anupam Mazumdar | Probing the parameter space for an MSSM inflation and the neutralino
dark matter | 9 pages, 6 figures, Latex | Phys.Rev.D75:075018,2007 | 10.1103/PhysRevD.75.075018 | MIFP-07-06 | hep-ph | null | The flat directions LLe and udd within the minimal supersymmetric Standard
Model provide all the necessary ingredients for a successful inflation with the
right amplitude of the scalar density perturbations, negligible gravity waves
and the spectral tilt within 2\sigma observed range 0.92 \leq n_s \leq 1.0. In
this paper we explore the available parameter space for inflation in
conjunction with a thermal cold dark matter abundance within the minimal
supergravity model. Remarkably for the inflaton, which is a combination of
squarks and sleptons, there is a stau-neutralino coannihilation region below
the inflaton mass 500 GeV for the observed density perturbations and the tilt
of the spectrum. For such a low mass of the inflaton the LHC is capable of
discovering the inflaton candidates within a short period of its operation.
Inflation is also compatible with the focus point region which opens up for the
inflaton masses above TeV. We show that embedding MSSM within SO(10) can
naturally favor this region.
| [
{
"created": "Sun, 11 Feb 2007 18:41:18 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Allahverdi",
"Rouzbeh",
""
],
[
"Dutta",
"Bhaskar",
""
],
[
"Mazumdar",
"Anupam",
""
]
] | The flat directions LLe and udd within the minimal supersymmetric Standard Model provide all the necessary ingredients for a successful inflation with the right amplitude of the scalar density perturbations, negligible gravity waves and the spectral tilt within 2\sigma observed range 0.92 \leq n_s \leq 1.0. In this paper we explore the available parameter space for inflation in conjunction with a thermal cold dark matter abundance within the minimal supergravity model. Remarkably for the inflaton, which is a combination of squarks and sleptons, there is a stau-neutralino coannihilation region below the inflaton mass 500 GeV for the observed density perturbations and the tilt of the spectrum. For such a low mass of the inflaton the LHC is capable of discovering the inflaton candidates within a short period of its operation. Inflation is also compatible with the focus point region which opens up for the inflaton masses above TeV. We show that embedding MSSM within SO(10) can naturally favor this region. |
hep-ph/0412426 | Kei Iida | Kei Iida (RIKEN BNL) | Magnetic vortex in color-flavor locked quark matter | 8 pages, 1 figure | Phys.Rev. D71 (2005) 054011 | 10.1103/PhysRevD.71.054011 | null | hep-ph | null | Within Ginzburg-Landau theory, we study the structure of a magnetic vortex in
color-flavor locked quark matter. This vortex is characterized by winding of
the SU(3) phase in color-flavor space, as well as by the presence of a
color-flavor unlocked condensate in the core. We estimate the upper and lower
critical fields and the critical Ginzburg-Landau parameter that distinguishes
between type I and type II superconductors.
| [
{
"created": "Fri, 31 Dec 2004 07:43:53 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Iida",
"Kei",
"",
"RIKEN BNL"
]
] | Within Ginzburg-Landau theory, we study the structure of a magnetic vortex in color-flavor locked quark matter. This vortex is characterized by winding of the SU(3) phase in color-flavor space, as well as by the presence of a color-flavor unlocked condensate in the core. We estimate the upper and lower critical fields and the critical Ginzburg-Landau parameter that distinguishes between type I and type II superconductors. |
0812.2966 | Diana Nicmorus | D. Nicmorus, G. Eichmann, A. Krassnigg, R. Alkofer | Faddeev equations: a view of baryon properties | 5 pages, 2 figures. Contributed to the 8th Conference Quark
Confinement and the Hadron Spectrum, Mainz, Germany, 1-6 September 2008 | PoS Confinement8:052,2008 | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a calculation of the three-quark core contribution to the mass of
the Delta-baryon in a Poincare-covariant Faddeev framework. A consistent setup
for the dressed-quark propagator, the quark-quark and quark-diquark
interactions is used, where all the ingredients are solutions of their
respective Dyson-Schwinger or Bethe-Salpeter equations in rainbow-ladder
truncation. We discuss the evolution of the Delta mass with the current-quark
mass and compare to the previously obtained mass of the nucleon.
| [
{
"created": "Tue, 16 Dec 2008 04:07:26 GMT",
"version": "v1"
}
] | 2009-06-25 | [
[
"Nicmorus",
"D.",
""
],
[
"Eichmann",
"G.",
""
],
[
"Krassnigg",
"A.",
""
],
[
"Alkofer",
"R.",
""
]
] | We present a calculation of the three-quark core contribution to the mass of the Delta-baryon in a Poincare-covariant Faddeev framework. A consistent setup for the dressed-quark propagator, the quark-quark and quark-diquark interactions is used, where all the ingredients are solutions of their respective Dyson-Schwinger or Bethe-Salpeter equations in rainbow-ladder truncation. We discuss the evolution of the Delta mass with the current-quark mass and compare to the previously obtained mass of the nucleon. |
hep-ph/0106203 | Dimitri Melikhov | M. Beyer, D. Melikhov, N. Nikitin, and B. Stech | Weak annihilation in the rare radiative $B\to \rho\gamma$ decay | revtex, 11 pages | Phys.Rev. D64 (2001) 094006 | 10.1103/PhysRevD.64.094006 | HD-THEP-01-18 | hep-ph | null | The ampitude of the $B\to\rho\gamma$ decay induced by the flavour-changing
neutral currents contains the penguin contribution and the weak-annihilation
contribution generated by the 4-quark operators in the effective Hamiltonian.
The penguin contribution is known quite well. We analyse the weak-annihilation
which is suppressed by the heavy-quark mass compared to the penguin
contribution.
In the factorization approximation, the weak annihilation amplitude is
represented in terms of the leptonic decay constants and the meson-photon
matrix elements of the weak currents. The latter contain the $B\gamma$,
$\rho\gamma$ transition form factors and contact terms determined by the
equations of motion. We calculate the $B\gamma$ and $\rho\gamma$ form factors
within the relativistic dispersion approach and obtain numerical estimates for
the weak annihilation amplitude.
| [
{
"created": "Mon, 18 Jun 2001 20:41:23 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Beyer",
"M.",
""
],
[
"Melikhov",
"D.",
""
],
[
"Nikitin",
"N.",
""
],
[
"Stech",
"B.",
""
]
] | The ampitude of the $B\to\rho\gamma$ decay induced by the flavour-changing neutral currents contains the penguin contribution and the weak-annihilation contribution generated by the 4-quark operators in the effective Hamiltonian. The penguin contribution is known quite well. We analyse the weak-annihilation which is suppressed by the heavy-quark mass compared to the penguin contribution. In the factorization approximation, the weak annihilation amplitude is represented in terms of the leptonic decay constants and the meson-photon matrix elements of the weak currents. The latter contain the $B\gamma$, $\rho\gamma$ transition form factors and contact terms determined by the equations of motion. We calculate the $B\gamma$ and $\rho\gamma$ form factors within the relativistic dispersion approach and obtain numerical estimates for the weak annihilation amplitude. |
2405.09326 | David Cabo-Almeida | David Cabo-Almeida | Exploring $t$-Channel Models for Dark Matter | 4 pages, 3 figures, contribution to the 2024 Electroweak session of
the 58th Rencontres de Moriond | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We report on a comprehensive study of the Direct Detection phenomenology of
singlet Dark Matter $t$-channel portal models. For that purpose, we present a
complete computation of the loop-induced direct detection cross-section for
both scalar and fermionic Dark Matter candidates. We complete the study by
comparing the results with current and future bounds from Direct Detection
experiments and requiring the correct Dark Matter relic density.
| [
{
"created": "Wed, 15 May 2024 13:26:26 GMT",
"version": "v1"
}
] | 2024-05-16 | [
[
"Cabo-Almeida",
"David",
""
]
] | We report on a comprehensive study of the Direct Detection phenomenology of singlet Dark Matter $t$-channel portal models. For that purpose, we present a complete computation of the loop-induced direct detection cross-section for both scalar and fermionic Dark Matter candidates. We complete the study by comparing the results with current and future bounds from Direct Detection experiments and requiring the correct Dark Matter relic density. |
1011.3901 | Sun YanJun | Yan-Jun Sun, Zuo-Hong Li, Tao Huang | $B_{(s)}\to S$ transitions in the light cone sum rules with the chiral
current | 22 pages,16 figures | Phys.Rev.D83:025024,2011 | 10.1103/PhysRevD.83.025024 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | $B_{(s)}$ semi-leptonic decays to the light scalar meson, $B_{(s)}\to S
l\bar{\nu}_l, S l \bar{l}\,\,(l=e,\mu,\tau)$, are investigated in the QCD
light-cone sum rules (LCSR) with chiral current correlator. Having little
knowledge of ingredients of the scalar mesons, we confine ourself to the two
quark picture for them and work with the two possible Scenarios. The resulting
sum rules for the form factors receive no contributions from the twist-3
distribution amplitudes (DA's), in comparison with the calculation of the
conventional LCSR approach where the twist-3 parts play usually an important
role. We specify the range of the squared momentum transfer $q^2$, in which the
operator product expansion (OPE) for the correlators remains valid
approximately. It is found that the form factors satisfy a relation consistent
with the prediction of soft collinear effective theory (SCET). In the effective
range we investigate behaviors of the form factors and differential decay
widthes and compare our calculations with the observations from other
approaches. The present findings can be beneficial to experimentally identify
physical properties of the scalar mesons.
| [
{
"created": "Wed, 17 Nov 2010 07:27:22 GMT",
"version": "v1"
},
{
"created": "Mon, 17 Jan 2011 08:45:06 GMT",
"version": "v2"
}
] | 2015-03-17 | [
[
"Sun",
"Yan-Jun",
""
],
[
"Li",
"Zuo-Hong",
""
],
[
"Huang",
"Tao",
""
]
] | $B_{(s)}$ semi-leptonic decays to the light scalar meson, $B_{(s)}\to S l\bar{\nu}_l, S l \bar{l}\,\,(l=e,\mu,\tau)$, are investigated in the QCD light-cone sum rules (LCSR) with chiral current correlator. Having little knowledge of ingredients of the scalar mesons, we confine ourself to the two quark picture for them and work with the two possible Scenarios. The resulting sum rules for the form factors receive no contributions from the twist-3 distribution amplitudes (DA's), in comparison with the calculation of the conventional LCSR approach where the twist-3 parts play usually an important role. We specify the range of the squared momentum transfer $q^2$, in which the operator product expansion (OPE) for the correlators remains valid approximately. It is found that the form factors satisfy a relation consistent with the prediction of soft collinear effective theory (SCET). In the effective range we investigate behaviors of the form factors and differential decay widthes and compare our calculations with the observations from other approaches. The present findings can be beneficial to experimentally identify physical properties of the scalar mesons. |
1811.09603 | Monika Blanke | Monika Blanke, Andreas Crivellin, Stefan de Boer, Teppei Kitahara,
Marta Moscati, Ulrich Nierste and Ivan Ni\v{s}and\v{z}i\'c | Impact of polarization observables and $ B_c\to \tau \nu$ on new physics
explanations of the $b\to c \tau \nu$ anomaly | 16 pages, 6 figures; v2: clarifying comments and few references
added, matches version published in PRD; v3: typo corrected in eq. (28).
Updated results based on the HFLAV average for spring 2019 are available in
arXiv:1905.08253 | Phys. Rev. D 99, 075006 (2019) | 10.1103/PhysRevD.99.075006 | PSI-PR-18-16; TTP-18-42 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The combined analysis of the BaBar, Belle, and LHCb data on $B\to D\tau\nu$,
$B\to D^*\tau\nu$ and $B_c\to J/\Psi\tau\nu$ decay observables shows evidence
of physics beyond the Standard Model (SM). In this article, we study all the
one- and two-dimensional scenarios which can be generated by adding a single
new particle to the SM. We put special emphasis on the model-discriminating
power of $F_L(D^*)$ and of the $\tau$ polarizations, and especially on the
constraint from the branching fraction ${\rm BR}(B_c\to\tau\nu)$. We critically
review this constraint and do not support the aggressive limit of ${\rm
BR}(B_c\to\tau\nu)<10\%$ used in some analyses. While the impact of $F_L(D^*)$
is currently still limited, the ${\rm BR}(B_c\to\tau\nu)$ constraint has a
significant impact: depending on whether one uses a limit of $60\%$, $30\%$ or
$10\%$, the pull for new physics (NP) in scalar operators changes drastically.
More specifically, for a conservative $60\%$ limit a scenario with scalar
operators gives the best fit to data, while for an aggressive $10\%$ limit this
scenario is strongly disfavored and the best fit is obtained in a scenario in
which only a left-handed vector operator is generated. We find a sum rule for
the branching ratios of $B\to D\tau\nu$, $B\to D^*\tau\nu$ and $\Lambda_b\to
\Lambda_c\tau\nu$ which holds for any NP contribution to the Wilson
coefficients. This sum rule entails an enhancement of ${\rm BR}(\Lambda_b\to
\Lambda_c\tau\nu)$ over its SM prediction by $(24\pm 6)\%$ for the current
$\mathcal{R}(D^{(*)})$ data.
| [
{
"created": "Fri, 23 Nov 2018 18:57:36 GMT",
"version": "v1"
},
{
"created": "Tue, 2 Apr 2019 15:12:05 GMT",
"version": "v2"
},
{
"created": "Wed, 22 May 2019 08:09:57 GMT",
"version": "v3"
}
] | 2019-05-23 | [
[
"Blanke",
"Monika",
""
],
[
"Crivellin",
"Andreas",
""
],
[
"de Boer",
"Stefan",
""
],
[
"Kitahara",
"Teppei",
""
],
[
"Moscati",
"Marta",
""
],
[
"Nierste",
"Ulrich",
""
],
[
"Nišandžić",
"Ivan",
""
]
] | The combined analysis of the BaBar, Belle, and LHCb data on $B\to D\tau\nu$, $B\to D^*\tau\nu$ and $B_c\to J/\Psi\tau\nu$ decay observables shows evidence of physics beyond the Standard Model (SM). In this article, we study all the one- and two-dimensional scenarios which can be generated by adding a single new particle to the SM. We put special emphasis on the model-discriminating power of $F_L(D^*)$ and of the $\tau$ polarizations, and especially on the constraint from the branching fraction ${\rm BR}(B_c\to\tau\nu)$. We critically review this constraint and do not support the aggressive limit of ${\rm BR}(B_c\to\tau\nu)<10\%$ used in some analyses. While the impact of $F_L(D^*)$ is currently still limited, the ${\rm BR}(B_c\to\tau\nu)$ constraint has a significant impact: depending on whether one uses a limit of $60\%$, $30\%$ or $10\%$, the pull for new physics (NP) in scalar operators changes drastically. More specifically, for a conservative $60\%$ limit a scenario with scalar operators gives the best fit to data, while for an aggressive $10\%$ limit this scenario is strongly disfavored and the best fit is obtained in a scenario in which only a left-handed vector operator is generated. We find a sum rule for the branching ratios of $B\to D\tau\nu$, $B\to D^*\tau\nu$ and $\Lambda_b\to \Lambda_c\tau\nu$ which holds for any NP contribution to the Wilson coefficients. This sum rule entails an enhancement of ${\rm BR}(\Lambda_b\to \Lambda_c\tau\nu)$ over its SM prediction by $(24\pm 6)\%$ for the current $\mathcal{R}(D^{(*)})$ data. |
2008.06545 | Sascha Diefenbacher | Anja Butter, Sascha Diefenbacher, Gregor Kasieczka, Benjamin Nachman,
and Tilman Plehn | GANplifying Event Samples | 15 pages, 7 figures, fixed two equations, extended acknowledgments,
addressed referee comments, improved figure readability | SciPost Phys. 10, 139 (2021) | 10.21468/SciPostPhys.10.6.139 | null | hep-ph hep-ex physics.data-an stat.ML | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A critical question concerning generative networks applied to event
generation in particle physics is if the generated events add statistical
precision beyond the training sample. We show for a simple example with
increasing dimensionality how generative networks indeed amplify the training
statistics. We quantify their impact through an amplification factor or
equivalent numbers of sampled events.
| [
{
"created": "Fri, 14 Aug 2020 19:00:21 GMT",
"version": "v1"
},
{
"created": "Wed, 16 Sep 2020 15:31:52 GMT",
"version": "v2"
},
{
"created": "Thu, 25 Mar 2021 17:34:25 GMT",
"version": "v3"
}
] | 2021-06-11 | [
[
"Butter",
"Anja",
""
],
[
"Diefenbacher",
"Sascha",
""
],
[
"Kasieczka",
"Gregor",
""
],
[
"Nachman",
"Benjamin",
""
],
[
"Plehn",
"Tilman",
""
]
] | A critical question concerning generative networks applied to event generation in particle physics is if the generated events add statistical precision beyond the training sample. We show for a simple example with increasing dimensionality how generative networks indeed amplify the training statistics. We quantify their impact through an amplification factor or equivalent numbers of sampled events. |
hep-ph/0010180 | Houri Ziaeepour | Houri Ziaeepour | Two-Brane Models and BBN | 8 pages, 3 figures; All comments are welcome. A typo has been removed
from equations 19, 21, and 24 | null | null | null | hep-ph astro-ph gr-qc hep-th | null | We obtain a class of solutions for the AdS$_5$ two-brane models by imposing
the observed value of cosmological constant and Newton coupling constant on the
visible brane. When all terms up to the first order of matter density are
included, the cosmological evolution on the observable brane depends on the
equation of state of the matter and consequently when the pressure exists, the
cosmology of these models deviates from FLRW cosmology. We show that it is
possible to choose the matter equation of state on the hidden brane to
neutralize its contribution on the cosmological evolution of the visible brane.
We compare the prediction of these models for primordial {\it $^4$He} yield
with observations. In standard BBN with $n_{\nu}^{light} = 3$ this brane model
is ruled out. If in addition to 3 SM neutrinos there is one light sterile
neutrino, this model reconciles the observed {\it $^4$He} yield with a high
${\Omega}_b \sim 0.033 h^{-2}$ suggested by BOOMERANG and MAXIMA experiments.
| [
{
"created": "Tue, 17 Oct 2000 08:43:14 GMT",
"version": "v1"
},
{
"created": "Fri, 27 Jul 2001 14:48:51 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Ziaeepour",
"Houri",
""
]
] | We obtain a class of solutions for the AdS$_5$ two-brane models by imposing the observed value of cosmological constant and Newton coupling constant on the visible brane. When all terms up to the first order of matter density are included, the cosmological evolution on the observable brane depends on the equation of state of the matter and consequently when the pressure exists, the cosmology of these models deviates from FLRW cosmology. We show that it is possible to choose the matter equation of state on the hidden brane to neutralize its contribution on the cosmological evolution of the visible brane. We compare the prediction of these models for primordial {\it $^4$He} yield with observations. In standard BBN with $n_{\nu}^{light} = 3$ this brane model is ruled out. If in addition to 3 SM neutrinos there is one light sterile neutrino, this model reconciles the observed {\it $^4$He} yield with a high ${\Omega}_b \sim 0.033 h^{-2}$ suggested by BOOMERANG and MAXIMA experiments. |
2402.15581 | Erwin Handoko Tanin | Michael A. Fedderke, David E. Kaplan, Anubhav Mathur, Surjeet
Rajendran, and Erwin H. Tanin | Fireball anti-nucleosynthesis | 42 pages, 10 figures, journal version | Phys.Rev.D 109 (2024) 12, 123028 | 10.1103/PhysRevD.109.123028 | null | hep-ph astro-ph.CO astro-ph.GA astro-ph.HE | http://creativecommons.org/licenses/by/4.0/ | The tentative identification of approximately ten relativistic anti-helium
cosmic-ray events at AMS-02 would, if confirmed, challenge our understanding of
the astrophysical synthesis of heavy anti-nuclei. We propose a novel scenario
for the enhanced production of such anti-nuclei that is triggered by isolated,
catastrophic injections of large quantities of energetic Standard Model (SM)
anti-quarks in our galaxy by physics beyond the Standard Model (BSM). We
demonstrate that SM anti-nucleosynthetic processes that occur in the resulting
rapidly expanding, thermalized fireballs of SM plasma can, for a reasonable
range of parameters, produce the reported tentative $\sim 2:1$ ratio of
anti-helium-3 to anti-helium-4 events at AMS-02, as well as their relativistic
boosts. Moreover, we show that this can be achieved without violating
anti-deuterium or anti-proton flux constraints for the appropriate anti-helium
fluxes. A plausible BSM paradigm for the catastrophic injections is the
collision of macroscopic composite dark-matter objects carrying large net
anti-baryon number. Such a scenario would require these objects to be
cosmologically stable, but to destabilize upon collision, promptly releasing a
fraction of their mass energy into SM anti-particles within a tiny volume. We
show that, in principle, the injection rate needed to attain the necessary
anti-helium fluxes and the energetic conditions required to seed the fireballs
appear possible to obtain in such a paradigm. We leave open the question of
constructing a BSM particle physics model to realize this, but we suggest two
concrete scenarios as promising targets for further investigation.
| [
{
"created": "Fri, 23 Feb 2024 19:40:09 GMT",
"version": "v1"
},
{
"created": "Tue, 18 Jun 2024 05:38:26 GMT",
"version": "v2"
}
] | 2024-06-28 | [
[
"Fedderke",
"Michael A.",
""
],
[
"Kaplan",
"David E.",
""
],
[
"Mathur",
"Anubhav",
""
],
[
"Rajendran",
"Surjeet",
""
],
[
"Tanin",
"Erwin H.",
""
]
] | The tentative identification of approximately ten relativistic anti-helium cosmic-ray events at AMS-02 would, if confirmed, challenge our understanding of the astrophysical synthesis of heavy anti-nuclei. We propose a novel scenario for the enhanced production of such anti-nuclei that is triggered by isolated, catastrophic injections of large quantities of energetic Standard Model (SM) anti-quarks in our galaxy by physics beyond the Standard Model (BSM). We demonstrate that SM anti-nucleosynthetic processes that occur in the resulting rapidly expanding, thermalized fireballs of SM plasma can, for a reasonable range of parameters, produce the reported tentative $\sim 2:1$ ratio of anti-helium-3 to anti-helium-4 events at AMS-02, as well as their relativistic boosts. Moreover, we show that this can be achieved without violating anti-deuterium or anti-proton flux constraints for the appropriate anti-helium fluxes. A plausible BSM paradigm for the catastrophic injections is the collision of macroscopic composite dark-matter objects carrying large net anti-baryon number. Such a scenario would require these objects to be cosmologically stable, but to destabilize upon collision, promptly releasing a fraction of their mass energy into SM anti-particles within a tiny volume. We show that, in principle, the injection rate needed to attain the necessary anti-helium fluxes and the energetic conditions required to seed the fireballs appear possible to obtain in such a paradigm. We leave open the question of constructing a BSM particle physics model to realize this, but we suggest two concrete scenarios as promising targets for further investigation. |
hep-ph/0606048 | Nikolaos Mavromatos | N.E. Mavromatos (King's Coll. London) and Sarben Sarkar (King's Coll.
London) | Methods of approaching decoherence in the flavour sector due to
space-time foam | 35 pages revtex, no figures, typos corrected in section III | Phys.Rev. D74 (2006) 036007 | 10.1103/PhysRevD.74.036007 | null | hep-ph gr-qc hep-th | null | In the first part of this work we discuss possible effects of stochastic
space-time foam configurations of quantum gravity on the propagation of
``flavoured'' (Klein-Gordon and Dirac) neutral particles, such as neutral
mesons and neutrinos. The formalism is not the usually assumed Lindblad one,
but it is based on random averages of quantum fluctuations of space time
metrics over which the propagation of the matter particles is considered. We
arrive at expressions for the respective oscillation probabilities between
flavours which are quite distinct from the ones pertaining to Lindblad-type
decoherence, including in addition to the (expected) Gaussian decay with time,
a modification to oscillation behaviour, as well as a power-law cutoff of the
time-profile of the respective probability. In the second part we consider
space-time foam configurations of quantum-fluctuating charged black holes as a
way of generating (parts of) neutrino mass differences, mimicking appropriately
the celebrated MSW effects of neutrinos in stochastically fluctuating random
media. We pay particular attention to disentangling genuine quantum-gravity
effects from ordinary effects due to the propagation of a neutrino through
ordinary matter. Our results are of interest to precision tests of quantum
gravity models using neutrinos as probes.
| [
{
"created": "Mon, 5 Jun 2006 14:39:13 GMT",
"version": "v1"
},
{
"created": "Thu, 8 Jun 2006 09:23:40 GMT",
"version": "v2"
}
] | 2009-11-11 | [
[
"Mavromatos",
"N. E.",
"",
"King's Coll. London"
],
[
"Sarkar",
"Sarben",
"",
"King's Coll.\n London"
]
] | In the first part of this work we discuss possible effects of stochastic space-time foam configurations of quantum gravity on the propagation of ``flavoured'' (Klein-Gordon and Dirac) neutral particles, such as neutral mesons and neutrinos. The formalism is not the usually assumed Lindblad one, but it is based on random averages of quantum fluctuations of space time metrics over which the propagation of the matter particles is considered. We arrive at expressions for the respective oscillation probabilities between flavours which are quite distinct from the ones pertaining to Lindblad-type decoherence, including in addition to the (expected) Gaussian decay with time, a modification to oscillation behaviour, as well as a power-law cutoff of the time-profile of the respective probability. In the second part we consider space-time foam configurations of quantum-fluctuating charged black holes as a way of generating (parts of) neutrino mass differences, mimicking appropriately the celebrated MSW effects of neutrinos in stochastically fluctuating random media. We pay particular attention to disentangling genuine quantum-gravity effects from ordinary effects due to the propagation of a neutrino through ordinary matter. Our results are of interest to precision tests of quantum gravity models using neutrinos as probes. |
1006.5249 | Lei Guo | Liu Ning, Guo Lei, Ma Wen-Gan, Zhang Ren-You, and Han Liang | Supersymmetric QCD and CP-violation effects in $t \bar t Z^0$ production
at the LHC | 30pages, 24 figures, to be published in Phys. Rev. D | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the NLO QCD and the CP-violation effects in $t\bar{t}Z^0$
production at the Large Hadron Collider(LHC) in the minimal supersymmetric
standard model(MSSM). Our calculation shows that the total NLO QCD correction
in the framework of the CP-conserving MSSM significantly improves the scale
uncertainty at the leading order, and the contribution from the pure
supersymmetric QCD (pSQCD) correction can exceed $-8\%$ with the restrictions
of $90~GeV < p_T^t < 120~GeV$ and $120~GeV < p_T^Z < 150~GeV$, where $p_T^t$
and $p_T^Z$ are the transverse momenta of the top-quark and $Z^0$ gauge boson,
respectively. Our numerical results demonstrate that the pure SUSY QCD
correction generally suppresses the total SM-like QCD correction in the
CP-conserving MSSM, and tends to be a constant when either $\tilde{t}_1$ or
$\tilde{g}$ is heavy enough. We find also that the CP-odd asymmetry ${\cal
A}_{\Phi}$ can reach $2.17 \times 10^{-3}$, if the CP-phase angle really exists
in the coupling of gluino-stop-top.
| [
{
"created": "Mon, 28 Jun 2010 00:57:02 GMT",
"version": "v1"
},
{
"created": "Tue, 20 Jul 2010 07:23:27 GMT",
"version": "v2"
}
] | 2010-07-21 | [
[
"Ning",
"Liu",
""
],
[
"Lei",
"Guo",
""
],
[
"Wen-Gan",
"Ma",
""
],
[
"Ren-You",
"Zhang",
""
],
[
"Liang",
"Han",
""
]
] | We investigate the NLO QCD and the CP-violation effects in $t\bar{t}Z^0$ production at the Large Hadron Collider(LHC) in the minimal supersymmetric standard model(MSSM). Our calculation shows that the total NLO QCD correction in the framework of the CP-conserving MSSM significantly improves the scale uncertainty at the leading order, and the contribution from the pure supersymmetric QCD (pSQCD) correction can exceed $-8\%$ with the restrictions of $90~GeV < p_T^t < 120~GeV$ and $120~GeV < p_T^Z < 150~GeV$, where $p_T^t$ and $p_T^Z$ are the transverse momenta of the top-quark and $Z^0$ gauge boson, respectively. Our numerical results demonstrate that the pure SUSY QCD correction generally suppresses the total SM-like QCD correction in the CP-conserving MSSM, and tends to be a constant when either $\tilde{t}_1$ or $\tilde{g}$ is heavy enough. We find also that the CP-odd asymmetry ${\cal A}_{\Phi}$ can reach $2.17 \times 10^{-3}$, if the CP-phase angle really exists in the coupling of gluino-stop-top. |
hep-ph/9205201 | Drew Peterson | Heinz K\"onig and K. A. Peterson | Production of the Lightest Supersymmetric Particle in Electron-Photon
Collisions | 14 pages, 5 figures(not included) | Phys.Lett. B294 (1992) 110-114 | 10.1016/0370-2693(92)91648-S | null | hep-ph | null | We present cross sections for the production of the lightest supersymmetric
particle as a neutralino state in the minimal supersymmetric standard model at
electron-photon colliders. The lightest supersymmetric particle mass is taken
at a value of 30 GeV which is slightly higher than its lowest experimental
bound of 20 GeV, and the masses of the scalar electron are varied. We show
partial cross sections of the energy and angular distribution of the outgoing
electron for different values of the centre of mass energy. As a result we show
that electron-photon collider experiments could be quite sensitive to the
detection of supersymmetric particles.
| [
{
"created": "Mon, 4 May 1992 20:46:05 GMT",
"version": "v1"
}
] | 2009-10-22 | [
[
"König",
"Heinz",
""
],
[
"Peterson",
"K. A.",
""
]
] | We present cross sections for the production of the lightest supersymmetric particle as a neutralino state in the minimal supersymmetric standard model at electron-photon colliders. The lightest supersymmetric particle mass is taken at a value of 30 GeV which is slightly higher than its lowest experimental bound of 20 GeV, and the masses of the scalar electron are varied. We show partial cross sections of the energy and angular distribution of the outgoing electron for different values of the centre of mass energy. As a result we show that electron-photon collider experiments could be quite sensitive to the detection of supersymmetric particles. |
2302.09747 | Hiroshi Okada | Jongkuk Kim, Hiroshi Okada | Fermi-LAT GeV excess and muon $g-2$ in a modular $A_4$ symmetry | 12 pages, 1 figure, 1 table | null | null | null | hep-ph | http://creativecommons.org/publicdomain/zero/1.0/ | The recent measurement of muon anomalous magnetic dipole moment (muon $g-2$)
suggests that there might exist new physics that dominantly interacts with
muons. The observed gamma-ray excess from Fermi-LAT indicates that dark matter
annihilates into a specific charged fermions. We propose a successful model
simultaneously to explain the Fermi-LAT GeV gamma-ray excess and sizable muon
$g-2$ with a modular $A_4$ symmetry. Due to nature of this symmetry, our DM
only interacts with pairs of muon and we explain sizable muon $g-2$ without
suffering from constraints of any lepton flavor violations. We numerically show
our allowed spaces on each measurements of Fermi-LAT, relic density of DM and
muon $g-2$, randomly scanning our input parameters.
| [
{
"created": "Mon, 20 Feb 2023 03:55:21 GMT",
"version": "v1"
}
] | 2023-02-21 | [
[
"Kim",
"Jongkuk",
""
],
[
"Okada",
"Hiroshi",
""
]
] | The recent measurement of muon anomalous magnetic dipole moment (muon $g-2$) suggests that there might exist new physics that dominantly interacts with muons. The observed gamma-ray excess from Fermi-LAT indicates that dark matter annihilates into a specific charged fermions. We propose a successful model simultaneously to explain the Fermi-LAT GeV gamma-ray excess and sizable muon $g-2$ with a modular $A_4$ symmetry. Due to nature of this symmetry, our DM only interacts with pairs of muon and we explain sizable muon $g-2$ without suffering from constraints of any lepton flavor violations. We numerically show our allowed spaces on each measurements of Fermi-LAT, relic density of DM and muon $g-2$, randomly scanning our input parameters. |
hep-ph/9508275 | Raymond Volkas | R. Foot and R. R. Volkas | Reconciling sterile neutrinos with big bang nucleosynthesis | 11 pages, LaTeX, no figures, several minor changes have been made, to
appear in Phys. Rev. Lett | Phys.Rev.Lett. 75 (1995) 4350 | 10.1103/PhysRevLett.75.4350 | UM-P-95/75 | hep-ph astro-ph | null | We re-examine the big bang nucleosynthesis (BBN) bounds on the mixing of
neutrinos with sterile species. These bounds depend on the assumption that the
relic neutrino asymmetry $L_{\nu}$ is very small. We show that for $L_{\nu}$
large enough (greater than about $10^{-5}$) the standard BBN bounds do not
apply. We apply this result to the sterile neutrino solution to the atmospheric
neutrino anomaly and show that for $L_{\nu} > 7 \times 10^{-5}$ it is
consistent with BBN. The BBN bounds on sterile neutrinos mixing with electron
neutrinos can also be weakened considerably.
| [
{
"created": "Thu, 10 Aug 1995 06:28:35 GMT",
"version": "v1"
},
{
"created": "Wed, 8 Nov 1995 05:48:07 GMT",
"version": "v2"
}
] | 2009-10-28 | [
[
"Foot",
"R.",
""
],
[
"Volkas",
"R. R.",
""
]
] | We re-examine the big bang nucleosynthesis (BBN) bounds on the mixing of neutrinos with sterile species. These bounds depend on the assumption that the relic neutrino asymmetry $L_{\nu}$ is very small. We show that for $L_{\nu}$ large enough (greater than about $10^{-5}$) the standard BBN bounds do not apply. We apply this result to the sterile neutrino solution to the atmospheric neutrino anomaly and show that for $L_{\nu} > 7 \times 10^{-5}$ it is consistent with BBN. The BBN bounds on sterile neutrinos mixing with electron neutrinos can also be weakened considerably. |
hep-ph/0201166 | Stephen Wong | J.I. Kapusta and S.M.H. Wong | Possible Evidence of Disoriented Chiral Condensates from the Anomaly in
Omega and AntiOmega Abundances at the SPS | paper presented at the ICPAQGP-2001, Jaipur, India | Pramana60:1099-1102,2002 | 10.1007/BF02707038 | null | hep-ph nucl-ex nucl-th | null | No conventional picture of nucleus-nucleus collisions has yet been able to
explain the abundance of Omega and AntiOmega in central collisions between Pb
nuclei at 158 A GeV at the CERN SPS. We argue that such a deviation from
predictions of statistical thermal models and numerical simulations is evidence
that they are produced as topological defects in the form of skyrmions arising
from the formation of disoriented chiral condensates. The estimated domain size
falls in the right range to be consistent with the so far non-observation of
DCC from the distribution of neutral pions.
| [
{
"created": "Fri, 18 Jan 2002 00:07:26 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Kapusta",
"J. I.",
""
],
[
"Wong",
"S. M. H.",
""
]
] | No conventional picture of nucleus-nucleus collisions has yet been able to explain the abundance of Omega and AntiOmega in central collisions between Pb nuclei at 158 A GeV at the CERN SPS. We argue that such a deviation from predictions of statistical thermal models and numerical simulations is evidence that they are produced as topological defects in the form of skyrmions arising from the formation of disoriented chiral condensates. The estimated domain size falls in the right range to be consistent with the so far non-observation of DCC from the distribution of neutral pions. |
1006.2738 | Carlos Louren\c{c}o | Pietro Faccioli, Carlos Lourenco, Joao Seixas and Hermine K. Woehri | Towards the experimental clarification of quarkonium polarization | Submitted to EPJC | Eur.Phys.J.C69:657-673,2010 | 10.1140/epjc/s10052-010-1420-5 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We highlight issues which are often underestimated in the experimental
analyses on quarkonium polarization: the relation between the parameters of the
angular distributions and the angular momentum composition of the quarkonium,
the importance of the choice of the reference frame, the interplay between
observed decay and production kinematics, and the consequent influence of the
experimental acceptance on the comparison between experimental measurements and
theoretical calculations. Given the puzzles raised by the available
experimental results, new measurements must provide more detailed information,
such that physical conclusions can be derived without relying on
model-dependent assumptions. We describe a frame-invariant formalism which
minimizes the dependence of the measurements on the experimental acceptance,
facilitates the comparison with theoretical calculations, and probes systematic
effects due to experimental biases. This formalism is a direct and generic
consequence of the rotational invariance of the dilepton decay distribution and
is independent of any assumptions specific to particular models of quarkonium
production. The use of this improved approach, which exploits the intrinsic
multidimensionality of the problem, will significantly contribute to a faster
progress in our understanding of quarkonium production, especially if adopted
as a common analysis framework by the LHC experiments, which will soon perform
analyses of quarkonium polarization in proton-proton collisions.
| [
{
"created": "Mon, 14 Jun 2010 15:19:51 GMT",
"version": "v1"
}
] | 2014-11-21 | [
[
"Faccioli",
"Pietro",
""
],
[
"Lourenco",
"Carlos",
""
],
[
"Seixas",
"Joao",
""
],
[
"Woehri",
"Hermine K.",
""
]
] | We highlight issues which are often underestimated in the experimental analyses on quarkonium polarization: the relation between the parameters of the angular distributions and the angular momentum composition of the quarkonium, the importance of the choice of the reference frame, the interplay between observed decay and production kinematics, and the consequent influence of the experimental acceptance on the comparison between experimental measurements and theoretical calculations. Given the puzzles raised by the available experimental results, new measurements must provide more detailed information, such that physical conclusions can be derived without relying on model-dependent assumptions. We describe a frame-invariant formalism which minimizes the dependence of the measurements on the experimental acceptance, facilitates the comparison with theoretical calculations, and probes systematic effects due to experimental biases. This formalism is a direct and generic consequence of the rotational invariance of the dilepton decay distribution and is independent of any assumptions specific to particular models of quarkonium production. The use of this improved approach, which exploits the intrinsic multidimensionality of the problem, will significantly contribute to a faster progress in our understanding of quarkonium production, especially if adopted as a common analysis framework by the LHC experiments, which will soon perform analyses of quarkonium polarization in proton-proton collisions. |
hep-ph/9904406 | Dr Tsou Sheung Tsun | HM Chan (Rutherford Appleton Lab) and ST Tsou (Oxford) | The Dualized Standard Model and its Applications---an Interim Report | 36 pages, Latex, 6 figures using eps; invited review to appear in
Int. J. Mod. Phys | null | null | RAL-TR-1999-015 | hep-ph | null | Based on a nonabelian generalization of electric-magnetic duality, the
Dualized Standard Model (DSM) suggests a natural explanation for exactly 3
generations of fermions as the `dual colour' $\widetilde{SU}(3)$ symmetry
broken in a particular manner. The resulting scheme then offers on the one hand
a fermion mass hierarchy and a perturbative method for calculating the mass and
mixing parameters of the Standard Model fermions, and on the other testable
predictions for new phenomena ranging from rare meson decays to ultra-high
energy cosmic rays. Calculations to 1-loop order gives, at the cost of
adjusting only 3 real parameters, values for the following quantities all
(except one) in very good agreement with experiment: the quark CKM matrix
elements $|V_{rs}|$, the lepton CKM matrix elements $|U_{rs}|$, and the second
generation masses $m_c, m_s, m_\mu$. This means, in particular, that it gives
near maximal mixing $U_{\mu3}$ between $\nu_\mu$ and $\nu_\tau$ as observed by
SuperKamiokande, Kamiokande and Soudan, while keeping small the corresponding
quark angles $V_{cb}, V_{ts}$. In addition, the scheme gives (i) rough
order-of-magnitude estimates for the masses of the lowest generation, (ii)
predictions for low energy FCNC effects such as $K_L \to e \mu$, (iii) a
possible explanation for the long-standing puzzle of air showers beyond the GZK
cut-off. All these together, however, still represent but a portion of the
possible physical consequences derivable from the DSM scheme the majority of
which are yet to be explored.
| [
{
"created": "Tue, 20 Apr 1999 16:15:18 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Chan",
"HM",
"",
"Rutherford Appleton Lab"
],
[
"Tsou",
"ST",
"",
"Oxford"
]
] | Based on a nonabelian generalization of electric-magnetic duality, the Dualized Standard Model (DSM) suggests a natural explanation for exactly 3 generations of fermions as the `dual colour' $\widetilde{SU}(3)$ symmetry broken in a particular manner. The resulting scheme then offers on the one hand a fermion mass hierarchy and a perturbative method for calculating the mass and mixing parameters of the Standard Model fermions, and on the other testable predictions for new phenomena ranging from rare meson decays to ultra-high energy cosmic rays. Calculations to 1-loop order gives, at the cost of adjusting only 3 real parameters, values for the following quantities all (except one) in very good agreement with experiment: the quark CKM matrix elements $|V_{rs}|$, the lepton CKM matrix elements $|U_{rs}|$, and the second generation masses $m_c, m_s, m_\mu$. This means, in particular, that it gives near maximal mixing $U_{\mu3}$ between $\nu_\mu$ and $\nu_\tau$ as observed by SuperKamiokande, Kamiokande and Soudan, while keeping small the corresponding quark angles $V_{cb}, V_{ts}$. In addition, the scheme gives (i) rough order-of-magnitude estimates for the masses of the lowest generation, (ii) predictions for low energy FCNC effects such as $K_L \to e \mu$, (iii) a possible explanation for the long-standing puzzle of air showers beyond the GZK cut-off. All these together, however, still represent but a portion of the possible physical consequences derivable from the DSM scheme the majority of which are yet to be explored. |
hep-ph/9706274 | Carsten Paetzold | Jurgen Baacke, Katrin Heitmann, Carsten Patzold (Dortmund University) | Renormalization of nonequilibrium dynamics in FRW cosmology | 14 pages, RevTeX, some obvious typos corrected | Phys.Rev.D56:6556-6565,1997 | 10.1103/PhysRevD.56.6556 | DO-TH 97/11 | hep-ph gr-qc hep-th | null | We derive the renormalized nonequilibrium equations of motion for a scalar
field and its quantum back reaction in a conformally flat
Friedmann-Robertson-Walker universe. We use a fully covariant formalism
proposed by us recently for handling numerically and analytically
nonequilibrium dynamics in one-loop approximation. The system is assumed to be
in a conformal vacuum state initially. We use dimensional regularization; we
find that the counter terms can be chosen independent of the initial conditions
though the divergent leading order graphs do depend on them.
| [
{
"created": "Fri, 6 Jun 1997 14:21:05 GMT",
"version": "v1"
},
{
"created": "Mon, 28 Jul 1997 13:13:36 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"Baacke",
"Jurgen",
"",
"Dortmund University"
],
[
"Heitmann",
"Katrin",
"",
"Dortmund University"
],
[
"Patzold",
"Carsten",
"",
"Dortmund University"
]
] | We derive the renormalized nonequilibrium equations of motion for a scalar field and its quantum back reaction in a conformally flat Friedmann-Robertson-Walker universe. We use a fully covariant formalism proposed by us recently for handling numerically and analytically nonequilibrium dynamics in one-loop approximation. The system is assumed to be in a conformal vacuum state initially. We use dimensional regularization; we find that the counter terms can be chosen independent of the initial conditions though the divergent leading order graphs do depend on them. |
1906.07037 | Alessandro Bacchetta | Alessandro Bacchetta, Giuseppe Bozzi, Miguel G. Echevarria, Cristian
Pisano, Alexey Prokudin, Marco Radici | Azimuthal asymmetries in unpolarized SIDIS and Drell-Yan processes: a
case study towards TMD factorization at subleading twist | null | null | 10.1016/j.physletb.2019.134850 | JLAB-THY-19-2963 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider the azimuthal distribution of the final observed hadron in
semi-inclusive deep-inelastic scattering and the lepton pair in the Drell-Yan
process. In particular, we focus on the $\cos \phi$ modulation of the
unpolarized cross section and on its dependence upon transverse momentum. At
low transverse momentum, for these observables we propose a factorized
expression based on tree-level approach and conjecture that the same formula is
valid in transverse-momentum dependent (TMD) factorization when written in
terms of subtracted TMD parton distributions. Our formula correctly matches
with the collinear factorization results at high transverse momentum, solves a
long-standing problem and is a necessary step towards the extension of the TMD
factorization theorems up to the subleading twist.
| [
{
"created": "Mon, 17 Jun 2019 13:50:18 GMT",
"version": "v1"
}
] | 2019-08-14 | [
[
"Bacchetta",
"Alessandro",
""
],
[
"Bozzi",
"Giuseppe",
""
],
[
"Echevarria",
"Miguel G.",
""
],
[
"Pisano",
"Cristian",
""
],
[
"Prokudin",
"Alexey",
""
],
[
"Radici",
"Marco",
""
]
] | We consider the azimuthal distribution of the final observed hadron in semi-inclusive deep-inelastic scattering and the lepton pair in the Drell-Yan process. In particular, we focus on the $\cos \phi$ modulation of the unpolarized cross section and on its dependence upon transverse momentum. At low transverse momentum, for these observables we propose a factorized expression based on tree-level approach and conjecture that the same formula is valid in transverse-momentum dependent (TMD) factorization when written in terms of subtracted TMD parton distributions. Our formula correctly matches with the collinear factorization results at high transverse momentum, solves a long-standing problem and is a necessary step towards the extension of the TMD factorization theorems up to the subleading twist. |
0711.2950 | Thomas Schwetz | Patrick Huber, Mauro Mezzetto, Thomas Schwetz | On the impact of systematical uncertainties for the CP violation
measurement in superbeam experiments | 30 pages, 10 figures, version accepted for publication in JHEP | JHEP 0803:021,2008 | 10.1088/1126-6708/2008/03/021 | CERN-PH-TH/2007-227, VPI-IPNAS-07-09 | hep-ph hep-ex | null | Superbeam experiments can, in principle, achieve impressive sensitivities for
CP violation in neutrino oscillations for large $\theta_{13}$. We study how
those sensitivities depend on assumptions about systematical uncertainties. We
focus on the second phase of T2K, the so-called T2HK experiment, and we
explicitly include a near detector in the analysis. Our main result is that
even an idealised near detector cannot remove the dependence on systematical
uncertainties completely. Thus additional information is required. We identify
certain combinations of uncertainties, which are the key to improve the
sensitivity to CP violation, for example the ratio of electron to muon neutrino
cross sections and efficiencies. For uncertainties on this ratio larger than
2%, T2HK is systematics dominated. We briefly discuss how our results apply to
a possible two far detector configuration, called T2KK. We do not find a
significant advantage with respect to the reduction of systematical errors for
the measurement of CP violation for this setup.
| [
{
"created": "Mon, 19 Nov 2007 15:00:08 GMT",
"version": "v1"
},
{
"created": "Thu, 28 Feb 2008 10:14:45 GMT",
"version": "v2"
}
] | 2009-01-06 | [
[
"Huber",
"Patrick",
""
],
[
"Mezzetto",
"Mauro",
""
],
[
"Schwetz",
"Thomas",
""
]
] | Superbeam experiments can, in principle, achieve impressive sensitivities for CP violation in neutrino oscillations for large $\theta_{13}$. We study how those sensitivities depend on assumptions about systematical uncertainties. We focus on the second phase of T2K, the so-called T2HK experiment, and we explicitly include a near detector in the analysis. Our main result is that even an idealised near detector cannot remove the dependence on systematical uncertainties completely. Thus additional information is required. We identify certain combinations of uncertainties, which are the key to improve the sensitivity to CP violation, for example the ratio of electron to muon neutrino cross sections and efficiencies. For uncertainties on this ratio larger than 2%, T2HK is systematics dominated. We briefly discuss how our results apply to a possible two far detector configuration, called T2KK. We do not find a significant advantage with respect to the reduction of systematical errors for the measurement of CP violation for this setup. |
1607.01001 | Alexandros Karam | Alexandros Karam and Kyriakos Tamvakis | Dark Matter from a Classically Scale-Invariant $SU(3)_X$ | 39 pp, 5 figures, 3 tables, comments added, minor corrections,
updated references, matches version published in PRD | Phys. Rev. D 94, 055004 (2016) | 10.1103/PhysRevD.94.055004 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this work we study a classically scale-invariant extension of the Standard
Model in which the dark matter and electroweak scales are generated through the
Coleman-Weinberg mechanism. The extra $SU(3)_X$ gauge factor gets completely
broken by the vacuum expectation values of two scalar triplets. Out of the
eight resulting massive vector bosons the three lightest are stable due to an
intrinsic $Z_2\times Z_2'$ discrete symmetry and can constitute dark matter
candidates. We analyze the phenomenological viability of the predicted
multi-Higgs sector imposing theoretical and experimental constraints. We
perform a comprehensive analysis of the dark matter predictions of the model
solving numerically the set of coupled Boltzmann equations involving all
relevant dark matter processes and explore the direct detection prospects of
the dark matter candidates.
| [
{
"created": "Mon, 4 Jul 2016 19:35:21 GMT",
"version": "v1"
},
{
"created": "Thu, 14 Jul 2016 19:30:00 GMT",
"version": "v2"
},
{
"created": "Thu, 6 Oct 2016 17:00:33 GMT",
"version": "v3"
}
] | 2016-10-07 | [
[
"Karam",
"Alexandros",
""
],
[
"Tamvakis",
"Kyriakos",
""
]
] | In this work we study a classically scale-invariant extension of the Standard Model in which the dark matter and electroweak scales are generated through the Coleman-Weinberg mechanism. The extra $SU(3)_X$ gauge factor gets completely broken by the vacuum expectation values of two scalar triplets. Out of the eight resulting massive vector bosons the three lightest are stable due to an intrinsic $Z_2\times Z_2'$ discrete symmetry and can constitute dark matter candidates. We analyze the phenomenological viability of the predicted multi-Higgs sector imposing theoretical and experimental constraints. We perform a comprehensive analysis of the dark matter predictions of the model solving numerically the set of coupled Boltzmann equations involving all relevant dark matter processes and explore the direct detection prospects of the dark matter candidates. |
hep-ph/0311101 | Alexander D. Mitov | Alexander Mitov | Applications of Perturbative Quantum Chromodynamics to Processes with
Heavy Quarks | 143 pages, PhD-thesis, Univ. of Rochester | null | null | null | hep-ph | null | In this thesis we study the b-quark fragmentation in top decay as well as the
effect of the threshold resummation on heavy quark production in
charged-current DIS.
To predict the spectrum of b-flavored hadrons in top decay, we calculate at
NLO the QCD corrections for bottom production in top decay with the b-mass
fully taken into account. Using the perturbative fragmentation function
formalism we then resum with NLL accuracy large collinear logs of the ratio of
bottom-to-top mass, which leads to an essential improvement of the result. Next
we perform the threshold resummation for the coefficient function for top decay
with NLL accuracy. That resummation leads to an important improvement of the
b-spectrum in the large energy fraction region. Finally, we extract information
for the non-perturbative b-fragmentation into hadrons from e^+e^- data and make
a prediction for the spectrum of those b-flavored hadrons produced in top-quark
decay. Our second application is to charm production in charged-current DIS. We
first calculate with NLL accuracy the soft-gluon resummed coefficient function
for heavy quark production (initiated by a light quark) in DIS. Our result is
applicable for the case of low momentum transfer that is of the order of the
mass of the heavy quark. We also make a connection of this result to the known
result for massless quark production. We then apply this result for charm quark
production at NuTeV and HERA for a wide range of the transferred momentum, and
present the effect of the resummation on the charm structure functions.
| [
{
"created": "Fri, 7 Nov 2003 22:04:44 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Mitov",
"Alexander",
""
]
] | In this thesis we study the b-quark fragmentation in top decay as well as the effect of the threshold resummation on heavy quark production in charged-current DIS. To predict the spectrum of b-flavored hadrons in top decay, we calculate at NLO the QCD corrections for bottom production in top decay with the b-mass fully taken into account. Using the perturbative fragmentation function formalism we then resum with NLL accuracy large collinear logs of the ratio of bottom-to-top mass, which leads to an essential improvement of the result. Next we perform the threshold resummation for the coefficient function for top decay with NLL accuracy. That resummation leads to an important improvement of the b-spectrum in the large energy fraction region. Finally, we extract information for the non-perturbative b-fragmentation into hadrons from e^+e^- data and make a prediction for the spectrum of those b-flavored hadrons produced in top-quark decay. Our second application is to charm production in charged-current DIS. We first calculate with NLL accuracy the soft-gluon resummed coefficient function for heavy quark production (initiated by a light quark) in DIS. Our result is applicable for the case of low momentum transfer that is of the order of the mass of the heavy quark. We also make a connection of this result to the known result for massless quark production. We then apply this result for charm quark production at NuTeV and HERA for a wide range of the transferred momentum, and present the effect of the resummation on the charm structure functions. |
1011.4202 | Roman Pasechnik | Roman Pasechnik and Vladimir Kuksa | Finite-width effects in the near-threshold ZZZ and ZWW production at ILC | 5 pages, 6 figures | null | 10.1142/S0217732311035651 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We calculate the cross-section of the near-threshold off-shell $ZZZ$ and
$ZW^+W^-$ production at the International Linear Collider taking into account
their instability and the principal part of NLO corrections. The calculations
are performed in the framework of the model of unstable particles with smeared
mass-shell. We show that the contribution of the finite $Z/W$ and $H$ widths
(their instability) is large in the Higgs resonance range and should be taken
into account in the Higgs boson searches at future colliders.
| [
{
"created": "Thu, 18 Nov 2010 14:47:22 GMT",
"version": "v1"
}
] | 2015-05-20 | [
[
"Pasechnik",
"Roman",
""
],
[
"Kuksa",
"Vladimir",
""
]
] | We calculate the cross-section of the near-threshold off-shell $ZZZ$ and $ZW^+W^-$ production at the International Linear Collider taking into account their instability and the principal part of NLO corrections. The calculations are performed in the framework of the model of unstable particles with smeared mass-shell. We show that the contribution of the finite $Z/W$ and $H$ widths (their instability) is large in the Higgs resonance range and should be taken into account in the Higgs boson searches at future colliders. |
1203.3131 | Luca Silvestrini | Enrico Franco, Satoshi Mishima and Luca Silvestrini | The Standard Model confronts CP violation in $D^0 \to \pi^+\pi^-$ and
$D^0 \to K^+K^-$ | 23 pages, 7 figures. v2: references added, final version to appear in
JHEP | null | 10.1007/JHEP05(2012)140 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The recently measured direct CP asymmetries in the processes $D^0\to
\pi^+\pi^-$ and $D^0\to K^+K^-$ show a significant deviation from the naive
Standard Model expectation. Using a general parameterization of the decay
amplitudes, we show that the measured branching ratios imply large SU(3)
breaking and large violations of the naive $1/N_c$ counting. Furthermore,
rescattering constrains the I=0 amplitudes in the $\pi\pi$ and $KK$ channels.
Combining all this information, we show that, with present errors, the observed
asymmetries are marginally compatible with the Standard Model. Improving the
experimental accuracy could lead to an indirect signal of new physics.
| [
{
"created": "Wed, 14 Mar 2012 16:38:14 GMT",
"version": "v1"
},
{
"created": "Thu, 26 Apr 2012 10:03:41 GMT",
"version": "v2"
}
] | 2015-06-04 | [
[
"Franco",
"Enrico",
""
],
[
"Mishima",
"Satoshi",
""
],
[
"Silvestrini",
"Luca",
""
]
] | The recently measured direct CP asymmetries in the processes $D^0\to \pi^+\pi^-$ and $D^0\to K^+K^-$ show a significant deviation from the naive Standard Model expectation. Using a general parameterization of the decay amplitudes, we show that the measured branching ratios imply large SU(3) breaking and large violations of the naive $1/N_c$ counting. Furthermore, rescattering constrains the I=0 amplitudes in the $\pi\pi$ and $KK$ channels. Combining all this information, we show that, with present errors, the observed asymmetries are marginally compatible with the Standard Model. Improving the experimental accuracy could lead to an indirect signal of new physics. |
1108.2394 | Vladimir Braun M | V.M. Braun, A.N. Manashov | Kinematic power corrections in off-forward hard reactions | 4 pages | Phys.Rev.Lett. 107 (2011) 202001 | 10.1103/PhysRevLett.107.202001 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We develop a general approach to the calculation of kinematic corrections
~t/Q^2, ~m^2/Q^2 in hard processes which involve momentum transfer from the
initial to the final hadron state. As the principal result, the complete
expression is derived for the time-ordered product of two electromagnetic
currents that includes all kinematic corrections to twist-four accuracy. The
results are immediately applicable e.g. to the studies of deeply-virtual
Compton scattering.
| [
{
"created": "Thu, 11 Aug 2011 13:29:27 GMT",
"version": "v1"
}
] | 2014-10-21 | [
[
"Braun",
"V. M.",
""
],
[
"Manashov",
"A. N.",
""
]
] | We develop a general approach to the calculation of kinematic corrections ~t/Q^2, ~m^2/Q^2 in hard processes which involve momentum transfer from the initial to the final hadron state. As the principal result, the complete expression is derived for the time-ordered product of two electromagnetic currents that includes all kinematic corrections to twist-four accuracy. The results are immediately applicable e.g. to the studies of deeply-virtual Compton scattering. |
2201.08179 | Zongjin Ong | Z. Ong, P. Agarwal, H.W. Ang, A.H. Chan, C.H. Oh | Forward-backward multiplicity distribution with the Chou-Yang model for
$pp$ collisions at $\sqrt{s}=$ 0.9, 7 and 8 TeV from the CMS experiment | null | null | 10.1142/S0217732323500141 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A Chou-Yang type multiplicity distribution comprising a total multiplicity
component and a binomial asymmetry component is used to describe charged hadron
multiplicity data at $\sqrt{s}=$ 0.9, 7 and 8 TeV from the CMS experiment at
CERN. The data was obtained and processed from the CERN Open Data Portal. For
the total multiplicity component, it was found that a convex sum of a Negative
Binomial Distribution and a Furry-Yule Distribution is able to describe the
shoulder-like structure characteristic of KNO scaling violation well. The mean
cluster size produced from collisions was also found to increase with collision
energy. A prediction is given for $pp$ collisions at $\sqrt{s}=$ 14 TeV.
| [
{
"created": "Thu, 20 Jan 2022 13:55:47 GMT",
"version": "v1"
},
{
"created": "Sun, 3 Apr 2022 08:17:45 GMT",
"version": "v2"
}
] | 2023-06-07 | [
[
"Ong",
"Z.",
""
],
[
"Agarwal",
"P.",
""
],
[
"Ang",
"H. W.",
""
],
[
"Chan",
"A. H.",
""
],
[
"Oh",
"C. H.",
""
]
] | A Chou-Yang type multiplicity distribution comprising a total multiplicity component and a binomial asymmetry component is used to describe charged hadron multiplicity data at $\sqrt{s}=$ 0.9, 7 and 8 TeV from the CMS experiment at CERN. The data was obtained and processed from the CERN Open Data Portal. For the total multiplicity component, it was found that a convex sum of a Negative Binomial Distribution and a Furry-Yule Distribution is able to describe the shoulder-like structure characteristic of KNO scaling violation well. The mean cluster size produced from collisions was also found to increase with collision energy. A prediction is given for $pp$ collisions at $\sqrt{s}=$ 14 TeV. |
hep-ph/0605296 | Itay Yavin | Lian-Tao Wang and Itay Yavin | Spin Measurements in Cascade Decays at the LHC | 36 pages, references added, 1 figure modified | JHEP 0704:032,2007 | 10.1088/1126-6708/2007/04/032 | null | hep-ph | null | We systematically study the possibility of determining the spin of new
particles after their discovery at the LHC. We concentrate on angular
correlations in cascade decays. Motivated by constraints of electroweak
precision tests and the potential of providing a Cold Dark Matter candidate, we
focus on scenarios of new physics in which some discrete symmetry guarantees
the existence of stable neutral particles which escape the detector. More
specifically, we compare supersymmetry with another generic scenario in which
new physics particles have the same spin as their Standard Model partners. A
survey of possibilities of observing spin correlations in a broad range of
decay channels is carried out, with interesting ones identified. Rather than
confining ourselves to one "collider friendly" benchmark point (such as SPS1a),
we describe the parameter region in which any particular decay channel is
effective. We conduct a more detailed study of chargino's spin determination in
the decay channel $\tilde{q}\to q + \tilde{C}^\pm \to q + W^\pm + LSP$. A scan
over the chargino and neutralino masses is performed. We find that as long as
the spectrum is not too degenerate the prospects for spin determination in this
channel are rather good.
| [
{
"created": "Fri, 26 May 2006 22:16:39 GMT",
"version": "v1"
},
{
"created": "Thu, 5 Apr 2007 15:06:53 GMT",
"version": "v2"
}
] | 2010-10-27 | [
[
"Wang",
"Lian-Tao",
""
],
[
"Yavin",
"Itay",
""
]
] | We systematically study the possibility of determining the spin of new particles after their discovery at the LHC. We concentrate on angular correlations in cascade decays. Motivated by constraints of electroweak precision tests and the potential of providing a Cold Dark Matter candidate, we focus on scenarios of new physics in which some discrete symmetry guarantees the existence of stable neutral particles which escape the detector. More specifically, we compare supersymmetry with another generic scenario in which new physics particles have the same spin as their Standard Model partners. A survey of possibilities of observing spin correlations in a broad range of decay channels is carried out, with interesting ones identified. Rather than confining ourselves to one "collider friendly" benchmark point (such as SPS1a), we describe the parameter region in which any particular decay channel is effective. We conduct a more detailed study of chargino's spin determination in the decay channel $\tilde{q}\to q + \tilde{C}^\pm \to q + W^\pm + LSP$. A scan over the chargino and neutralino masses is performed. We find that as long as the spectrum is not too degenerate the prospects for spin determination in this channel are rather good. |
1310.3825 | Florian Goertz | Adrian Carmona and Florian Goertz | Composite Taus and Higgs Decays | 7 pages, 2 figures. Proceedings of EPS-HEP2013, 18-24 July 2013,
Stockholm | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this talk, we describe the effects of extended fermion sectors, respecting
custodial symmetry, on Higgs production and decay. The resulting protection for
the Z->b_L b_L and Z->\tau_R \tau_R decays allows for potentially interesting
signals in Higgs physics, while maintaining the good agreement of the Standard
Model with precision tests. The setups can be motivated as the low energy
effective theories of the composite Higgs models MCHM_5 and MCHM_10, where the
spectra can be identified with the light custodians present in these theories.
We will show that these describe the relevant physics in the fermion sectors in
a simplified and transparent way. In contrast to previous studies of composite
models, the impact of a realistic lepton sector on the Higgs decays is taken
into account.
| [
{
"created": "Mon, 14 Oct 2013 20:00:02 GMT",
"version": "v1"
}
] | 2013-10-16 | [
[
"Carmona",
"Adrian",
""
],
[
"Goertz",
"Florian",
""
]
] | In this talk, we describe the effects of extended fermion sectors, respecting custodial symmetry, on Higgs production and decay. The resulting protection for the Z->b_L b_L and Z->\tau_R \tau_R decays allows for potentially interesting signals in Higgs physics, while maintaining the good agreement of the Standard Model with precision tests. The setups can be motivated as the low energy effective theories of the composite Higgs models MCHM_5 and MCHM_10, where the spectra can be identified with the light custodians present in these theories. We will show that these describe the relevant physics in the fermion sectors in a simplified and transparent way. In contrast to previous studies of composite models, the impact of a realistic lepton sector on the Higgs decays is taken into account. |
1802.01732 | Syuhei Iguro Mr | Syuhei Iguro and Yuji Omura | Status of the semileptonic $B$ decays and muon g-2 in general 2HDMs with
right-handed neutrinos | 33 pages, 21 figures, final version published in JHEP | null | 10.1007/JHEP05(2018)173 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper, we study the extended Standard Model (SM) with an extra Higgs
doublet and right-handed neutrinos. If the symmetry to distinguish the two
Higgs doublets is not assigned, flavor changing neutral currents (FCNCs)
involving the scalars are predicted even at the tree level. We investigate the
constraints on the FCNCs at the one-loop level, and especially study the
semileptonic $B$ meson decays, e.g. $B \to D^{(*)} \tau \nu$ and $B \to K^{(*)}
ll$ processes, where the SM predictions are more than $2 \sigma$ away from the
experimental results. We also consider the flavor-violating couplings involving
right-handed neutrinos and discuss if the parameters to explain the excesses of
the semileptonic $B$ decays can resolve the discrepancy in the the anomalous
muon magnetic moment. Based on the analysis, we propose the smoking-gun signals
of our model at the LHC.
| [
{
"created": "Mon, 5 Feb 2018 23:37:22 GMT",
"version": "v1"
},
{
"created": "Fri, 1 Jun 2018 01:38:42 GMT",
"version": "v2"
}
] | 2018-06-04 | [
[
"Iguro",
"Syuhei",
""
],
[
"Omura",
"Yuji",
""
]
] | In this paper, we study the extended Standard Model (SM) with an extra Higgs doublet and right-handed neutrinos. If the symmetry to distinguish the two Higgs doublets is not assigned, flavor changing neutral currents (FCNCs) involving the scalars are predicted even at the tree level. We investigate the constraints on the FCNCs at the one-loop level, and especially study the semileptonic $B$ meson decays, e.g. $B \to D^{(*)} \tau \nu$ and $B \to K^{(*)} ll$ processes, where the SM predictions are more than $2 \sigma$ away from the experimental results. We also consider the flavor-violating couplings involving right-handed neutrinos and discuss if the parameters to explain the excesses of the semileptonic $B$ decays can resolve the discrepancy in the the anomalous muon magnetic moment. Based on the analysis, we propose the smoking-gun signals of our model at the LHC. |
2109.07691 | Shu-Min Zhao | Shu-Min Zhao, Jian-Fei Zhang, Xi Wang, Xing-Xing Dong, Tai-Fu Feng | The strong first order electroweak phase transition in the $U(1)_X$SSM | 16pages,6figures | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | In the $U(1)_X$ extension of the minimal supersymmetric standard model, there
are three Higgs singlets and the corresponding trilinear terms in the Higgs
effective potential. These new terms can allow a strongly first order
electroweak phase transition(EWPT) for a wide parameter space. We use codes
CosmoTransitions to analyze the thermal evolution of the Higgs effective
potential and calculate nucleation temperature. To find reasonable parameter
spaces for strongly first order EWPT, we randomly scan many parameters, which
is numerically expensive. The diagrams are shown, that can lead to the 125 GeV
Higgs mass and satisfy the first order EWPT. This work benefits the
phenomenology of $U(1)_X$SSM and exploring new physics beyond the SM.
| [
{
"created": "Thu, 16 Sep 2021 03:15:15 GMT",
"version": "v1"
},
{
"created": "Mon, 9 Oct 2023 08:01:27 GMT",
"version": "v2"
}
] | 2023-10-10 | [
[
"Zhao",
"Shu-Min",
""
],
[
"Zhang",
"Jian-Fei",
""
],
[
"Wang",
"Xi",
""
],
[
"Dong",
"Xing-Xing",
""
],
[
"Feng",
"Tai-Fu",
""
]
] | In the $U(1)_X$ extension of the minimal supersymmetric standard model, there are three Higgs singlets and the corresponding trilinear terms in the Higgs effective potential. These new terms can allow a strongly first order electroweak phase transition(EWPT) for a wide parameter space. We use codes CosmoTransitions to analyze the thermal evolution of the Higgs effective potential and calculate nucleation temperature. To find reasonable parameter spaces for strongly first order EWPT, we randomly scan many parameters, which is numerically expensive. The diagrams are shown, that can lead to the 125 GeV Higgs mass and satisfy the first order EWPT. This work benefits the phenomenology of $U(1)_X$SSM and exploring new physics beyond the SM. |
hep-ph/9708244 | Peter Petreczky | F.Karsch, A.Patkos, P.Petreczky | Screened Perturbation Theory | Talk presented at Eotvos Conference in Science - 1997, Strong and
Electroweak Matter '97, 21-25 May 1997, Eger, Hungary, 5 pages, LaTeX, 2
figures | null | null | ITP Budapest Rep. 533 | hep-ph | null | A new perturbative scheme is proposed for the evaluation of the free energy
density of field theories at finite temperature. The screened loop expansion
takes into account exactly the phenomenon of screening in thermal
propagators.The approach is tested in the N-component scalar field theory at
2-loop level and also at 3-loop in the large $N$ limit. The perturbative series
generated by the screened loop expansion shows much better numerical
convergence than previous expansions generated in powers of the quartic
coupling.
| [
{
"created": "Tue, 5 Aug 1997 11:42:40 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Karsch",
"F.",
""
],
[
"Patkos",
"A.",
""
],
[
"Petreczky",
"P.",
""
]
] | A new perturbative scheme is proposed for the evaluation of the free energy density of field theories at finite temperature. The screened loop expansion takes into account exactly the phenomenon of screening in thermal propagators.The approach is tested in the N-component scalar field theory at 2-loop level and also at 3-loop in the large $N$ limit. The perturbative series generated by the screened loop expansion shows much better numerical convergence than previous expansions generated in powers of the quartic coupling. |
1912.00477 | Marco Bellagente | Marco Bellagente, Anja Butter, Gregor Kasieczka, Tilman Plehn, Ramon
Winterhalder | How to GAN away Detector Effects | 16 pages, 13 figures | SciPost Phys. 8, 070 (2020) | 10.21468/SciPostPhys.8.4.070 | null | hep-ph cs.LG | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | LHC analyses directly comparing data and simulated events bear the danger of
using first-principle predictions only as a black-box part of event simulation.
We show how simulations, for instance, of detector effects can instead be
inverted using generative networks. This allows us to reconstruct parton level
information from measured events. Our results illustrate how, in general, fully
conditional generative networks can statistically invert Monte Carlo
simulations. As a technical by-product we show how a maximum mean discrepancy
loss can be staggered or cooled.
| [
{
"created": "Sun, 1 Dec 2019 19:00:21 GMT",
"version": "v1"
},
{
"created": "Sat, 4 Jan 2020 07:43:34 GMT",
"version": "v2"
},
{
"created": "Fri, 13 Mar 2020 17:33:00 GMT",
"version": "v3"
},
{
"created": "Tue, 17 Mar 2020 07:12:29 GMT",
"version": "v4"
}
] | 2022-12-06 | [
[
"Bellagente",
"Marco",
""
],
[
"Butter",
"Anja",
""
],
[
"Kasieczka",
"Gregor",
""
],
[
"Plehn",
"Tilman",
""
],
[
"Winterhalder",
"Ramon",
""
]
] | LHC analyses directly comparing data and simulated events bear the danger of using first-principle predictions only as a black-box part of event simulation. We show how simulations, for instance, of detector effects can instead be inverted using generative networks. This allows us to reconstruct parton level information from measured events. Our results illustrate how, in general, fully conditional generative networks can statistically invert Monte Carlo simulations. As a technical by-product we show how a maximum mean discrepancy loss can be staggered or cooled. |
1709.09084 | S Dev Sharma | S. Dev, Desh Raj, Radha Raman Gautam | Neutrino mass matrices with three or four vanishing cofactors and non
diagonal charged lepton sector | 19 pages, 5 figures, 6 tables | Phys. Rev. D 96, 095002 (2017) | 10.1103/PhysRevD.96.095002 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the texture structures of lepton mass matrices with four
(five) non-zero elements in the charged lepton mass matrix and three (four)
vanishing cofactors in the neutrino mass matrix. Using weak basis
transformations, all possible textures for three and four vanishing cofactors
in $M_{\nu}$ are grouped into 7 classes and predictions for the unknown
parameters such as the Dirac CP violating phase and the effective Majorana mass
for the phenomenologically allowed textures have been obtained. We, also,
illustrate how such texture structures can be realized using discrete Abelian
flavor symmetries.
| [
{
"created": "Tue, 26 Sep 2017 15:15:32 GMT",
"version": "v1"
},
{
"created": "Mon, 27 Nov 2017 10:23:33 GMT",
"version": "v2"
}
] | 2017-11-28 | [
[
"Dev",
"S.",
""
],
[
"Raj",
"Desh",
""
],
[
"Gautam",
"Radha Raman",
""
]
] | We investigate the texture structures of lepton mass matrices with four (five) non-zero elements in the charged lepton mass matrix and three (four) vanishing cofactors in the neutrino mass matrix. Using weak basis transformations, all possible textures for three and four vanishing cofactors in $M_{\nu}$ are grouped into 7 classes and predictions for the unknown parameters such as the Dirac CP violating phase and the effective Majorana mass for the phenomenologically allowed textures have been obtained. We, also, illustrate how such texture structures can be realized using discrete Abelian flavor symmetries. |
2312.16304 | Sk Jeesun | Dilip Kumar Ghosh, Purusottam Ghosh, Sk Jeesun and Rahul Srivastava | Hubble Tension and Cosmological Imprints of $U(1)_X$ Gauge Symmetry:
$U(1)_{B_3-3 L_i}$ as a case study | typos fixed, main text 28 pages, 9 Figures | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | The current upper limit on $N_{\rm eff}$ at the time of CMB by Planck 2018
can place stringent constraints in the parameter space of BSM paradigms where
their additional interactions may affect neutrino decoupling. Motivated by this
fact in this paper we explore the consequences of light gauge boson ($Z'$)
emerging from local $U(1)_X$ symmetry in $N_{\rm eff}$ at the time of CMB.
First, we analyze the generic $U(1)_X$ models with arbitrary charge assignments
for the SM fermions and show that, in the context of $N_{\rm eff}$ the generic
$U(1)_X$ gauged models can be broadly classified into two categories, depending
on the charge assignments of first generation leptons. We then perform a
detailed analysis with two specific $U(1)_X$ models: $U(1)_{B_3-3L_e}$ and
$U(1)_{B_3-3L_\mu}$ and explore the contribution in $N_{\rm eff}$ due to the
presence of $Z'$ realized in those models. For comparison, we also showcase the
constraints from low energy experiments like: Borexino, Xenon 1T, neutrino
trident, etc. We show that in a specific parameter space, particularly in the
low mass region of $Z'$, the bound from $N_{\rm eff}$ (Planck 2018) is more
stringent than the experimental constraints. Additionally, a part of the
regions of the same parameter space may also relax the $H_0$ tension.
| [
{
"created": "Tue, 26 Dec 2023 19:20:26 GMT",
"version": "v1"
},
{
"created": "Tue, 2 Jan 2024 12:23:57 GMT",
"version": "v2"
}
] | 2024-01-03 | [
[
"Ghosh",
"Dilip Kumar",
""
],
[
"Ghosh",
"Purusottam",
""
],
[
"Jeesun",
"Sk",
""
],
[
"Srivastava",
"Rahul",
""
]
] | The current upper limit on $N_{\rm eff}$ at the time of CMB by Planck 2018 can place stringent constraints in the parameter space of BSM paradigms where their additional interactions may affect neutrino decoupling. Motivated by this fact in this paper we explore the consequences of light gauge boson ($Z'$) emerging from local $U(1)_X$ symmetry in $N_{\rm eff}$ at the time of CMB. First, we analyze the generic $U(1)_X$ models with arbitrary charge assignments for the SM fermions and show that, in the context of $N_{\rm eff}$ the generic $U(1)_X$ gauged models can be broadly classified into two categories, depending on the charge assignments of first generation leptons. We then perform a detailed analysis with two specific $U(1)_X$ models: $U(1)_{B_3-3L_e}$ and $U(1)_{B_3-3L_\mu}$ and explore the contribution in $N_{\rm eff}$ due to the presence of $Z'$ realized in those models. For comparison, we also showcase the constraints from low energy experiments like: Borexino, Xenon 1T, neutrino trident, etc. We show that in a specific parameter space, particularly in the low mass region of $Z'$, the bound from $N_{\rm eff}$ (Planck 2018) is more stringent than the experimental constraints. Additionally, a part of the regions of the same parameter space may also relax the $H_0$ tension. |
hep-ph/0609109 | Shao-Ming Wang | Wang Shao-Ming, Han Liang, Ma Wen-Gan, Zhang Ren-You, and Jiang Yi | QCD corrections to the R-parity violating processes $p\bar{p}/pp \to
e\mu+X$ at hadron colliders | 7 pages, 6 Postscript figures, to be appeared in Phy. Rev. D | Phys.Rev.D74:057902,2006 | 10.1103/PhysRevD.74.057902 | null | hep-ph | null | We present the QCD corrections to the processes $p\bar{p}/pp \to e\mu+X$ at
the Tevatron and the CERN large hadron collider(LHC). The numerical results
show that variation of K factor is in the range between $1.28(1.32)$ and
$1.79(1.58)$ at the Tevatron(LHC). We find that the QCD correction part from
the one-loop gluon-gluon fusion subprocess is remarkable at the LHC and should
be taken into account.
| [
{
"created": "Tue, 12 Sep 2006 02:08:20 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Shao-Ming",
"Wang",
""
],
[
"Liang",
"Han",
""
],
[
"Wen-Gan",
"Ma",
""
],
[
"Ren-You",
"Zhang",
""
],
[
"Yi",
"Jiang",
""
]
] | We present the QCD corrections to the processes $p\bar{p}/pp \to e\mu+X$ at the Tevatron and the CERN large hadron collider(LHC). The numerical results show that variation of K factor is in the range between $1.28(1.32)$ and $1.79(1.58)$ at the Tevatron(LHC). We find that the QCD correction part from the one-loop gluon-gluon fusion subprocess is remarkable at the LHC and should be taken into account. |
1110.6818 | Anders Tranberg | Tomas Brauner, Olli Taanila, Anders Tranberg, Aleksi Vuorinen | Temperature Dependence of Standard Model CP Violation | 4 pages, 2 figures. Additional non-trivial cancellations lead to
vanishing of P-odd sector also at finite temperature. Minor additional
modifications and clarifications, conclusions otherwise unchanged. Published
version | null | 10.1103/PhysRevLett.108.041601 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We analyze the temperature dependence of CP violation effects in the Standard
Model by determining the effective action of its bosonic fields, obtained after
integrating out the fermions from the theory and performing a covariant
gradient expansion. We find non-vanishing CP violating terms starting at the
sixth order of the expansion, albeit only in the C odd/P even sector, with
coefficients that depend on quark masses, CKM matrix elements, temperature and
the magnitude of the Higgs field. The CP violating effects are observed to
decrease rapidly with temperature, which has important implications for the
generation of a matter-antimatter asymmetry in the early Universe. Our results
suggest that the cold electroweak baryogenesis scenario may be viable within
the Standard Model, provided the electroweak transition temperature is at most
of order 1 GeV.
| [
{
"created": "Mon, 31 Oct 2011 15:03:21 GMT",
"version": "v1"
},
{
"created": "Fri, 6 Jan 2012 13:21:16 GMT",
"version": "v2"
}
] | 2015-03-19 | [
[
"Brauner",
"Tomas",
""
],
[
"Taanila",
"Olli",
""
],
[
"Tranberg",
"Anders",
""
],
[
"Vuorinen",
"Aleksi",
""
]
] | We analyze the temperature dependence of CP violation effects in the Standard Model by determining the effective action of its bosonic fields, obtained after integrating out the fermions from the theory and performing a covariant gradient expansion. We find non-vanishing CP violating terms starting at the sixth order of the expansion, albeit only in the C odd/P even sector, with coefficients that depend on quark masses, CKM matrix elements, temperature and the magnitude of the Higgs field. The CP violating effects are observed to decrease rapidly with temperature, which has important implications for the generation of a matter-antimatter asymmetry in the early Universe. Our results suggest that the cold electroweak baryogenesis scenario may be viable within the Standard Model, provided the electroweak transition temperature is at most of order 1 GeV. |
1909.13153 | George Wojcik | George N. Wojcik and Thomas G. Rizzo | Local $SU(2) \times U(1)$ Quark Flavor Symmetry in the RS Bulk | 84 pages+ references, 17 figures | null | 10.1007/JHEP02(2020)179 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose a model of quark flavor based on an additional $SU(2)\times U(1)$
local symmetry in a warped extra dimensional bulk. In contrast to other works,
we break the additional gauge symmetry in the bulk via two complex scalars
which acquire bulk vevs, rather than relying on brane-localized symmetry
breaking. A gauge-covariant Kaluza-Klein decomposition of a theory with a bulk
spontaneously broken gauge symmetry is performed, and exact expressions for the
bulk profiles of all physical particles in such systems are given. The SM quark
masses and mixings are then recreated using gauge-covariant bulk quark mass
terms and Yukawa-like couplings to the new bulk scalars. A numerical sampling
of points in the model parameter space that recreate the quark masses and
mixings is performed at a KK scale of $M_{KK} =5$ TeV. We then compute the
$\Delta F = 2$ 4-quark operators arising from our new flavor gauge bosons and
scalars, and those arising from Kaluza-Klein modes of SM gauge bosons. By
decoupling one of our bulk scalar fields to all quark fields except the
right-handed up-like sector, we find that it is possible to greatly suppress
tree-level contributions to the highly constrained Kaon mixing parameters.
Instead, the dominant constraints on the model emerge from neutral $B_d$ and
$D$ meson mixing. These constraints are explored with our numerical sampling of
the model parameter space, and the specific contribution of the new flavor
gauge bosons and scalars is discussed. We find that for a significant range of
realistic flavor gauge couplings, the new gauge bosons compete with the
normally dominant gluon flavor-changing currents, but flavor-changing operators
emerging from the bulk scalar fields are highly suppressed. Finally, we briefly
comment on flavor constraints that are independent of the flavor gauge sector
arising from the $Z \bar{b}_L b_L$ coupling and rare top decays.
| [
{
"created": "Sat, 28 Sep 2019 21:23:55 GMT",
"version": "v1"
},
{
"created": "Wed, 15 Jan 2020 23:39:38 GMT",
"version": "v2"
}
] | 2020-03-18 | [
[
"Wojcik",
"George N.",
""
],
[
"Rizzo",
"Thomas G.",
""
]
] | We propose a model of quark flavor based on an additional $SU(2)\times U(1)$ local symmetry in a warped extra dimensional bulk. In contrast to other works, we break the additional gauge symmetry in the bulk via two complex scalars which acquire bulk vevs, rather than relying on brane-localized symmetry breaking. A gauge-covariant Kaluza-Klein decomposition of a theory with a bulk spontaneously broken gauge symmetry is performed, and exact expressions for the bulk profiles of all physical particles in such systems are given. The SM quark masses and mixings are then recreated using gauge-covariant bulk quark mass terms and Yukawa-like couplings to the new bulk scalars. A numerical sampling of points in the model parameter space that recreate the quark masses and mixings is performed at a KK scale of $M_{KK} =5$ TeV. We then compute the $\Delta F = 2$ 4-quark operators arising from our new flavor gauge bosons and scalars, and those arising from Kaluza-Klein modes of SM gauge bosons. By decoupling one of our bulk scalar fields to all quark fields except the right-handed up-like sector, we find that it is possible to greatly suppress tree-level contributions to the highly constrained Kaon mixing parameters. Instead, the dominant constraints on the model emerge from neutral $B_d$ and $D$ meson mixing. These constraints are explored with our numerical sampling of the model parameter space, and the specific contribution of the new flavor gauge bosons and scalars is discussed. We find that for a significant range of realistic flavor gauge couplings, the new gauge bosons compete with the normally dominant gluon flavor-changing currents, but flavor-changing operators emerging from the bulk scalar fields are highly suppressed. Finally, we briefly comment on flavor constraints that are independent of the flavor gauge sector arising from the $Z \bar{b}_L b_L$ coupling and rare top decays. |
1611.05004 | Joydeep Roy | Joydeep Roy | Imposing LHC constraints on the combined Anomaly and $Z^\prime$
Mediation Mechanism of Supersymmetry Breaking | Proceedings of 38th International Conference on High Energy Physics
(ICHEP 2016), 3-10 August 2016, Chicago, USA | PoS(ICHEP2016)126 | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Combining anomaly with $Z^\prime$ mediation allows us to solve the tachyonic
problem of the former and avoid fine tuning in the latter. This model includes
an extra $U(1)^\prime$ gauge symmetry and extra singlet scalar $S$ which
provides a solution to the `$\mu$ problem' of the Minimal Supersymmetric
Standard Model (MSSM). The low-energy particle spectrum is calculated from the
UV inputs using the Renormalization Group Equations. The benchmark points
considered in the original model, suggested before the Higgs discovery,
predicted a Higgs mass heavier than the generic MSSM value. In 2012, the Higgs
particle was discovered and found to have a mass of 125 GeV. Therefore, we can
use that value and other current LHC data to scan the parameter space and
update the predictions of the model, in particular the mass of the $Z^\prime$
gauge boson.
| [
{
"created": "Tue, 15 Nov 2016 19:49:23 GMT",
"version": "v1"
}
] | 2019-01-17 | [
[
"Roy",
"Joydeep",
""
]
] | Combining anomaly with $Z^\prime$ mediation allows us to solve the tachyonic problem of the former and avoid fine tuning in the latter. This model includes an extra $U(1)^\prime$ gauge symmetry and extra singlet scalar $S$ which provides a solution to the `$\mu$ problem' of the Minimal Supersymmetric Standard Model (MSSM). The low-energy particle spectrum is calculated from the UV inputs using the Renormalization Group Equations. The benchmark points considered in the original model, suggested before the Higgs discovery, predicted a Higgs mass heavier than the generic MSSM value. In 2012, the Higgs particle was discovered and found to have a mass of 125 GeV. Therefore, we can use that value and other current LHC data to scan the parameter space and update the predictions of the model, in particular the mass of the $Z^\prime$ gauge boson. |
hep-ph/9610516 | null | J. D. Bjorken | Future Directions for QCD | Latex, 6 pages, to be published in the proceedings of the 1996
DPF/DPB Summer Study of New Directions for High Energy Physics, Snowmass, CO,
June 25-July 12, 1996 | ECONF C960625:OPS004,1996 | null | SLAC-PUB-7341 | hep-ph | null | New directions for exploring QCD at future high-energy colliders are
sketched. These include jets within jets, BFKL dynamics, soft and hard
diffraction, searches for disoriented chiral condensate, and doing a better job
on minimum bias physics. The new experimental opportunities include
electron-ion collisions at HERA, a new collider detector at the C0 region of
the TeVatron, and the FELIX initiative at the LHC.
| [
{
"created": "Mon, 28 Oct 1996 23:36:10 GMT",
"version": "v1"
}
] | 2011-04-15 | [
[
"Bjorken",
"J. D.",
""
]
] | New directions for exploring QCD at future high-energy colliders are sketched. These include jets within jets, BFKL dynamics, soft and hard diffraction, searches for disoriented chiral condensate, and doing a better job on minimum bias physics. The new experimental opportunities include electron-ion collisions at HERA, a new collider detector at the C0 region of the TeVatron, and the FELIX initiative at the LHC. |
1501.07885 | Sebastian J\"ager | Sebastian J\"ager | BEACH 2014 Theory Summary | as published in the BEACH 2014 proceedings | null | 10.1088/1742-6596/556/1/012077 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | I summarize key aspects of the quest for physics beyond the Standard Model in
flavour physics as discussed at the BEACH 2014 conference in Birmingham.
| [
{
"created": "Fri, 30 Jan 2015 18:54:44 GMT",
"version": "v1"
}
] | 2015-02-03 | [
[
"Jäger",
"Sebastian",
""
]
] | I summarize key aspects of the quest for physics beyond the Standard Model in flavour physics as discussed at the BEACH 2014 conference in Birmingham. |
2403.15000 | Jorge Segovia | M.C. Gordillo and J. Segovia | Heavy multiquark systems as clusters of smaller units -- a diffusion
Monte Carlo calculation -- | 6 pages, 2 tables | null | null | null | hep-ph hep-ex hep-lat nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Multiquark systems appear less frequently than mesons and baryons despite the
enormous world-wide experimental effort that has been made during the last two
decades. In this work, we will propose a possible explanation for that fact,
restricting ourselves to the case of sets including only $c$ and $\bar{c}$
quarks. We will show that those multiquarks can be thought as different
combinations of smaller units that associate together to produce colorless
assemblies with a definite value of the total spin. For instance, for the
$cccccc$ hexaquark with $S=0$, we have three possibilities: a set of six
undistinguishable $c$ quarks, an association of two $ccc$ baryons, or a set of
three $cc$ diquarks close together. This means we can have three different
values for the mass of an open-charm hexaquark with $S=0$. Using the diffusion
Monte Carlo method, we calculate all possible combinations compatible with
tetraquark $cc \bar{c} \bar{c}$, pentaquark $cccc \bar{c}$, open-charm $cccccc$
and hidden-charm $ccc \bar{c} \bar{c} \bar{c}$ hexaquark structures with the
minimum value of total spin ($S=0$ or $S=1/2$). We consider compact structures
with radial wave functions including interactions between all the quarks in the
cluster. We find that, in all cases, the mass of the multiquark decreases with
the number of small units that conform the set of quarks. For instance, an open
charm hexaquark made up of three diquarks has a smaller mass than a set of six
of $c$ undistinguishable units. When the pieces that conform the multiquark are
themselves colorless with a definite value of the total spin, the cluster
splits into those smaller units that separate infinitely from each other.
| [
{
"created": "Fri, 22 Mar 2024 07:24:28 GMT",
"version": "v1"
}
] | 2024-03-25 | [
[
"Gordillo",
"M. C.",
""
],
[
"Segovia",
"J.",
""
]
] | Multiquark systems appear less frequently than mesons and baryons despite the enormous world-wide experimental effort that has been made during the last two decades. In this work, we will propose a possible explanation for that fact, restricting ourselves to the case of sets including only $c$ and $\bar{c}$ quarks. We will show that those multiquarks can be thought as different combinations of smaller units that associate together to produce colorless assemblies with a definite value of the total spin. For instance, for the $cccccc$ hexaquark with $S=0$, we have three possibilities: a set of six undistinguishable $c$ quarks, an association of two $ccc$ baryons, or a set of three $cc$ diquarks close together. This means we can have three different values for the mass of an open-charm hexaquark with $S=0$. Using the diffusion Monte Carlo method, we calculate all possible combinations compatible with tetraquark $cc \bar{c} \bar{c}$, pentaquark $cccc \bar{c}$, open-charm $cccccc$ and hidden-charm $ccc \bar{c} \bar{c} \bar{c}$ hexaquark structures with the minimum value of total spin ($S=0$ or $S=1/2$). We consider compact structures with radial wave functions including interactions between all the quarks in the cluster. We find that, in all cases, the mass of the multiquark decreases with the number of small units that conform the set of quarks. For instance, an open charm hexaquark made up of three diquarks has a smaller mass than a set of six of $c$ undistinguishable units. When the pieces that conform the multiquark are themselves colorless with a definite value of the total spin, the cluster splits into those smaller units that separate infinitely from each other. |
2105.02928 | Zahra Ghalenovi | Zahra Ghalenovi and Masoumeh Moazzen Sorkhi | Mass spectra and transition magnetic moments of low lying charmed
baryons in a quark model | arXiv admin note: text overlap with arXiv:1707.01319 | Int J Mod Phys E 30 (2021) 2150063 | 10.1142/S0218301321500634 | null | hep-ph nucl-th | http://creativecommons.org/licenses/by/4.0/ | Excited state mass spectra of the low lying single charmed baryons with non
strangeness have been calculated in a hypercentral approach. The
six-dimensional hyperradial Schr\"{o}dinger equation is solved by applying a
simple variational method. We extend our scheme to predict the magnetic moments
and the $ \frac{3}{2}^+ \rightarrow \frac{1}{2}^+ $ transition magnetic moments
of $ \Sigma_{c} $ and $ \Lambda_{c} $ state baryons. A comparison of our
results with the experimental data and predictions obtained in recent models is
also presented.
| [
{
"created": "Thu, 6 May 2021 19:51:35 GMT",
"version": "v1"
}
] | 2021-11-09 | [
[
"Ghalenovi",
"Zahra",
""
],
[
"Sorkhi",
"Masoumeh Moazzen",
""
]
] | Excited state mass spectra of the low lying single charmed baryons with non strangeness have been calculated in a hypercentral approach. The six-dimensional hyperradial Schr\"{o}dinger equation is solved by applying a simple variational method. We extend our scheme to predict the magnetic moments and the $ \frac{3}{2}^+ \rightarrow \frac{1}{2}^+ $ transition magnetic moments of $ \Sigma_{c} $ and $ \Lambda_{c} $ state baryons. A comparison of our results with the experimental data and predictions obtained in recent models is also presented. |
hep-ph/0404105 | Mark Trodden | Mark Trodden and Tanmay Vachaspati | Topology in the Little Higgs Models | 14 pages, 2 figures | Phys.Rev. D70 (2004) 065008 | 10.1103/PhysRevD.70.065008 | null | hep-ph hep-th | null | We investigate the implications of the nontrivial vacuum structure of little
Higgs models. In particular, focusing on the littlest Higgs model, we
demonstrate the existence of three types of topological defects. One is a
global cosmic string that is truly topological. The second is more subtle; a
semilocal cosmic string, which may be stable due to dynamical effects. The
final defect is a $Z_2$ monopole solution with an unusual structure. We briefly
discuss the possible cosmological consequences of such nonperturbative
structures, although we note that these depend crucially on the fermionic
content of the models.
| [
{
"created": "Mon, 12 Apr 2004 20:17:12 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Trodden",
"Mark",
""
],
[
"Vachaspati",
"Tanmay",
""
]
] | We investigate the implications of the nontrivial vacuum structure of little Higgs models. In particular, focusing on the littlest Higgs model, we demonstrate the existence of three types of topological defects. One is a global cosmic string that is truly topological. The second is more subtle; a semilocal cosmic string, which may be stable due to dynamical effects. The final defect is a $Z_2$ monopole solution with an unusual structure. We briefly discuss the possible cosmological consequences of such nonperturbative structures, although we note that these depend crucially on the fermionic content of the models. |
1403.2038 | Biswajoy Brahmachari | Biswajoy Brahmachari and Probir Roy | Constrained analytical interrelations in neutrino mixing | To be published in the Springer Proceedings in the Physics Series
under the heading of the XXI DAE-BRNS Symposium (Guwahati, India) | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Hermitian squared mass matrices of charged leptons and light neutrinos in the
flavor basis are studied under general additive lowest order perturbations away
from the tribimaximal (TBM) limit in which a weak basis with mass diagonal
charged leptons is chosen. Simple analytical expressions are found for the
three measurable TBM-deviants in terms of perturbation parameters appearing in
the neutrino and charged lepton eigenstates in the flavor basis. Taking
unnatural cancellations to be absent and charged lepton perturbation parameters
to be small, interrelations are derived among masses, mixing angles and the
amount of CP-violation.
| [
{
"created": "Sun, 9 Mar 2014 08:37:42 GMT",
"version": "v1"
},
{
"created": "Wed, 21 Jan 2015 12:58:06 GMT",
"version": "v2"
},
{
"created": "Mon, 13 Apr 2015 11:19:02 GMT",
"version": "v3"
},
{
"created": "Tue, 24 Nov 2015 09:42:13 GMT",
"version": "v4"
}
] | 2015-11-25 | [
[
"Brahmachari",
"Biswajoy",
""
],
[
"Roy",
"Probir",
""
]
] | Hermitian squared mass matrices of charged leptons and light neutrinos in the flavor basis are studied under general additive lowest order perturbations away from the tribimaximal (TBM) limit in which a weak basis with mass diagonal charged leptons is chosen. Simple analytical expressions are found for the three measurable TBM-deviants in terms of perturbation parameters appearing in the neutrino and charged lepton eigenstates in the flavor basis. Taking unnatural cancellations to be absent and charged lepton perturbation parameters to be small, interrelations are derived among masses, mixing angles and the amount of CP-violation. |
1412.2036 | Marie Bo\"er | Marie Bo\"er and Michel Guidal | Timelike Compton Scattering off the Proton: beam and/or target spin
asymmetries | 2 figures, 4 pages, PANIC 2014 conference proceeding | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a sample of results of our work to be published soon on Timelike
Compton scattering off the proton, in the framework of the Generalized Parton
Distributions formalism.
| [
{
"created": "Fri, 5 Dec 2014 15:55:24 GMT",
"version": "v1"
}
] | 2014-12-08 | [
[
"Boër",
"Marie",
""
],
[
"Guidal",
"Michel",
""
]
] | We present a sample of results of our work to be published soon on Timelike Compton scattering off the proton, in the framework of the Generalized Parton Distributions formalism. |
1402.3773 | Murat Koksal | M. K\"oksal | Anomalous quartic $ZZ\gamma\gamma$ couplings at the CLIC | 18 pages, 8 figures, 7 table | Eur. Phys. J. Plus (2015) 130: 75 | 10.1140/epjp/i2015-15075-7 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the sensitivity to anomalous quartic $ZZ\gamma\gamma$ couplings
through the processes $e^{+}e^{-}\rightarrow Z\, Z\, \gamma$, $e^{+}e^{-}
\rightarrow e^{+}\gamma^{*} e^{-} \rightarrow e^{+} Z\, Z\, e^{-}$ and
$e^{+}e^{-} \rightarrow e^{+}\gamma^{*} \gamma^{*} e^{-} \rightarrow e^{+}\,
Z\, Z\, e^{-}$ at the CLIC. We find $95\%$ confidence level bounds on these
coupling parameters defining by the dimension-six operators. The best bounds on
the anomalous $ZZ\gamma\gamma$ couplings among the three processes are obtained
from $e^{+}e^{-}\rightarrow Z\, Z\, \gamma$ at a center of mass energy of $3$
TeV and an integrated luminosity of $590$ fb$^{-1}$. We show that the best
bounds obtained on both the anomalous coupling parameters are of the order of
$10^{-8}$ GeV$^{-2}$, significantly improving the current bounds.
| [
{
"created": "Sun, 16 Feb 2014 08:38:16 GMT",
"version": "v1"
},
{
"created": "Mon, 24 Feb 2014 16:42:16 GMT",
"version": "v2"
},
{
"created": "Thu, 12 Mar 2015 13:02:50 GMT",
"version": "v3"
},
{
"created": "Thu, 16 Apr 2015 11:52:10 GMT",
"version": "v4"
}
] | 2015-04-17 | [
[
"Köksal",
"M.",
""
]
] | We study the sensitivity to anomalous quartic $ZZ\gamma\gamma$ couplings through the processes $e^{+}e^{-}\rightarrow Z\, Z\, \gamma$, $e^{+}e^{-} \rightarrow e^{+}\gamma^{*} e^{-} \rightarrow e^{+} Z\, Z\, e^{-}$ and $e^{+}e^{-} \rightarrow e^{+}\gamma^{*} \gamma^{*} e^{-} \rightarrow e^{+}\, Z\, Z\, e^{-}$ at the CLIC. We find $95\%$ confidence level bounds on these coupling parameters defining by the dimension-six operators. The best bounds on the anomalous $ZZ\gamma\gamma$ couplings among the three processes are obtained from $e^{+}e^{-}\rightarrow Z\, Z\, \gamma$ at a center of mass energy of $3$ TeV and an integrated luminosity of $590$ fb$^{-1}$. We show that the best bounds obtained on both the anomalous coupling parameters are of the order of $10^{-8}$ GeV$^{-2}$, significantly improving the current bounds. |
hep-ph/0010155 | Bob Delbourgo | R Delbourgo and Dongsheng Liu | On nonleptonic decays of supermultiplets | 19 pages, LaTeX; requires axodraw.sty | Austral.J.Phys.53:737-750,2000 | 10.1063/1.1330928 | UTAS-PHYS-00-21 | hep-ph | null | By describing strong interactions between hadrons via a relativistic
supermultiplet scheme and regarding weak interactions as a perturbation
thereof, we derive expressions for nonleptonic weak decay amplitudes in terms
of constituent quark masses and CKM angles, with no other parameters.
Application of this method leads to $\Delta I=1/2$ dominance in some
pseudoscalar meson decays if one scales down the couplings of heavy particles
by $\sqrt{M}$ mass factors, in keeping with heavy quark theory expectations.
However, certain B and D decay processes to kaons are badly predicted and point
to substantial soft gluon renormalization effects in W-quark interactions.
| [
{
"created": "Mon, 16 Oct 2000 04:52:55 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Delbourgo",
"R",
""
],
[
"Liu",
"Dongsheng",
""
]
] | By describing strong interactions between hadrons via a relativistic supermultiplet scheme and regarding weak interactions as a perturbation thereof, we derive expressions for nonleptonic weak decay amplitudes in terms of constituent quark masses and CKM angles, with no other parameters. Application of this method leads to $\Delta I=1/2$ dominance in some pseudoscalar meson decays if one scales down the couplings of heavy particles by $\sqrt{M}$ mass factors, in keeping with heavy quark theory expectations. However, certain B and D decay processes to kaons are badly predicted and point to substantial soft gluon renormalization effects in W-quark interactions. |
0811.1806 | Tae-Hun Lee | Shao-Hsuan Chiu, T. K. Kuo, Tae-Hun Lee, Chi Xiong | Mass Matrices and Their Renormalization | 18 pages, 13 figues | Phys.Rev.D79:013012,2009 | 10.1103/PhysRevD.79.013012 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We obtain explicitly the renormalization group equations for the quark mass
matrices in terms of a set of rephasing invariant parameters. For a range of
assumed high energy values for the mass ratios and mixing parameters, they are
found to evolve rapidly and develop hierarchies as the energy scale decreases.
To achieve the experimentally observed high degree of hierarchy, however, the
introduction of new models with specific properties becomes necessary.
| [
{
"created": "Wed, 12 Nov 2008 17:47:56 GMT",
"version": "v1"
},
{
"created": "Wed, 19 Nov 2008 21:57:00 GMT",
"version": "v2"
},
{
"created": "Sat, 31 Jan 2009 21:27:21 GMT",
"version": "v3"
}
] | 2010-04-21 | [
[
"Chiu",
"Shao-Hsuan",
""
],
[
"Kuo",
"T. K.",
""
],
[
"Lee",
"Tae-Hun",
""
],
[
"Xiong",
"Chi",
""
]
] | We obtain explicitly the renormalization group equations for the quark mass matrices in terms of a set of rephasing invariant parameters. For a range of assumed high energy values for the mass ratios and mixing parameters, they are found to evolve rapidly and develop hierarchies as the energy scale decreases. To achieve the experimentally observed high degree of hierarchy, however, the introduction of new models with specific properties becomes necessary. |
hep-ph/9601249 | Martin Beneke | M. Beneke and G. Buchalla | The $B_c$ Meson Lifetime | 18 pages, revtex, 2 figures as uudecoded file | Phys.Rev.D53:4991-5000,1996 | 10.1103/PhysRevD.53.4991 | SLAC-PUB-95-7080 | hep-ph | null | We investigate the total inclusive decay rate of the (ground state) $B_c$
meson within the framework of an operator product expansion in inverse powers
of the heavy quark masses and subsequent matching onto nonrelativistic QCD. The
expansion is organized as a series in the strong coupling and in powers of the
heavy quark velocities in the $B_c$, reflecting the nonrelativistic nature of a
heavy-heavy bound state. In this aspect the character of the expansion differs
from the more familiar case of heavy-light mesons. The framework incorporates
systematically corrections to the leading $b$- and $c$-quark decays due to
binding effects, as well as contributions from weak annihilation and Pauli
interference. Based on this approach we find for the $B_c$ meson lifetime
$\tau_{B_c}=(0.4 - 0.7)\,$ps, the dominant mechanism being the decay of the
charm constituent.
| [
{
"created": "Fri, 12 Jan 1996 02:34:49 GMT",
"version": "v1"
}
] | 2009-03-09 | [
[
"Beneke",
"M.",
""
],
[
"Buchalla",
"G.",
""
]
] | We investigate the total inclusive decay rate of the (ground state) $B_c$ meson within the framework of an operator product expansion in inverse powers of the heavy quark masses and subsequent matching onto nonrelativistic QCD. The expansion is organized as a series in the strong coupling and in powers of the heavy quark velocities in the $B_c$, reflecting the nonrelativistic nature of a heavy-heavy bound state. In this aspect the character of the expansion differs from the more familiar case of heavy-light mesons. The framework incorporates systematically corrections to the leading $b$- and $c$-quark decays due to binding effects, as well as contributions from weak annihilation and Pauli interference. Based on this approach we find for the $B_c$ meson lifetime $\tau_{B_c}=(0.4 - 0.7)\,$ps, the dominant mechanism being the decay of the charm constituent. |
1303.6338 | Nobuhito Maru | Nobuhito Maru | Metastable D-term Dynamical SUSY Breaking | 7 pages, 2 figures, contribution to SCGT12 "KMI-GCOE Workshop on
Strong Coupling Gauge Theories in the LHC Perspective", 4-7 Dec. 2012, Nagoya
University | null | 10.1142/9789814566254_0030 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the mechanism of the dynamical supersymmetry (SUSY) breaking at
the metastable vacuum in the N=1 U(N) SUSY gauge theory with adjoint
superfields. The dynamical SUSY breaking is triggered by the non-vanishing
D-term coupled to the observable sector, and is realized by the self-consistent
Hartree-Fock approximation of the NJL type while it eventually brings us the
non-vanishing F-term as well. We numerically check the local stability of our
metastable vacuum.
| [
{
"created": "Mon, 25 Mar 2013 22:36:23 GMT",
"version": "v1"
}
] | 2017-08-23 | [
[
"Maru",
"Nobuhito",
""
]
] | We present the mechanism of the dynamical supersymmetry (SUSY) breaking at the metastable vacuum in the N=1 U(N) SUSY gauge theory with adjoint superfields. The dynamical SUSY breaking is triggered by the non-vanishing D-term coupled to the observable sector, and is realized by the self-consistent Hartree-Fock approximation of the NJL type while it eventually brings us the non-vanishing F-term as well. We numerically check the local stability of our metastable vacuum. |
1905.05676 | Michael Strickland | Jacob Boyd, Thomas Cook, Ajaharul Islam, and Michael Strickland | Heavy quarkonium suppression beyond the adiabatic limit | 28 pages, 9 figures, 1 table; v2 - typos fixed, numerical benchmarks
added; published version | Phys. Rev. D 100, 076019 (2019) | 10.1103/PhysRevD.100.076019 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Many prior studies of in-medium quarkonium suppression have implicitly made
use of an adiabatic approximation in which it was assumed that the heavy quark
potential is a slowly varying function of time. In the adiabatic limit, one can
separately determine the in-medium breakup rate and the medium time evolution,
folding these together only at the end of the calculation. In this paper, we
relax this assumption by solving the 3d Schrodinger equation in real-time in
order to compute quarkonium suppression dynamically. We compare results
obtained using the adiabatic approximation with real-time calculations for both
harmonic oscillator and realistic complex heavy quark potentials. Using the
latter, we find that, for the Upsilon(1s), the difference between the adiabatic
approximation and full real-time evolution is at the few percent level,
however, for the Upsilon(2s), we find that the correction can be as large as
18% in low temperature regions. For the J/Psi, we find a larger difference
between the dynamical evolution and the adiabatic approximation, with the error
reaching approximately 36%.
| [
{
"created": "Tue, 14 May 2019 15:38:16 GMT",
"version": "v1"
},
{
"created": "Tue, 29 Oct 2019 12:16:38 GMT",
"version": "v2"
}
] | 2019-10-30 | [
[
"Boyd",
"Jacob",
""
],
[
"Cook",
"Thomas",
""
],
[
"Islam",
"Ajaharul",
""
],
[
"Strickland",
"Michael",
""
]
] | Many prior studies of in-medium quarkonium suppression have implicitly made use of an adiabatic approximation in which it was assumed that the heavy quark potential is a slowly varying function of time. In the adiabatic limit, one can separately determine the in-medium breakup rate and the medium time evolution, folding these together only at the end of the calculation. In this paper, we relax this assumption by solving the 3d Schrodinger equation in real-time in order to compute quarkonium suppression dynamically. We compare results obtained using the adiabatic approximation with real-time calculations for both harmonic oscillator and realistic complex heavy quark potentials. Using the latter, we find that, for the Upsilon(1s), the difference between the adiabatic approximation and full real-time evolution is at the few percent level, however, for the Upsilon(2s), we find that the correction can be as large as 18% in low temperature regions. For the J/Psi, we find a larger difference between the dynamical evolution and the adiabatic approximation, with the error reaching approximately 36%. |
1509.05841 | Shoichi Kashiwase | Romy H. S. Budhi, Shoichi Kashiwase and Daijiro Suematsu | Inflation due to a non-minimal coupling of singlet scalars in the
radiative seesaw model | 28 pages, 6 figures, typos fixed, reference added, additional comment | Phys. Rev. D 93, 013022 (2016) | 10.1103/PhysRevD.93.013022 | KANAZAWA-15-14 | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The radiative neutrino mass model with inert doublet dark matter is a
promising model for the present experimental issues which cannot be explained
within the standard model. We study an extension of this model focusing on
cosmological features brought about from the scalar sector. Inflation due to
singlet scalars with hierarchical non-minimal couplings with the Ricci scalar
may give a favorable solution for both neutrino masses and baryon number
asymmetry in the Universe.
| [
{
"created": "Sat, 19 Sep 2015 02:13:24 GMT",
"version": "v1"
},
{
"created": "Thu, 4 Feb 2016 07:57:41 GMT",
"version": "v2"
}
] | 2016-02-05 | [
[
"Budhi",
"Romy H. S.",
""
],
[
"Kashiwase",
"Shoichi",
""
],
[
"Suematsu",
"Daijiro",
""
]
] | The radiative neutrino mass model with inert doublet dark matter is a promising model for the present experimental issues which cannot be explained within the standard model. We study an extension of this model focusing on cosmological features brought about from the scalar sector. Inflation due to singlet scalars with hierarchical non-minimal couplings with the Ricci scalar may give a favorable solution for both neutrino masses and baryon number asymmetry in the Universe. |
hep-ph/9510353 | Juan Jose Godina Nava | J. J. Godina | T-violation in $K_{\mu3}$ decay in a general two-Higgs doublet model | 6 pages, latex, accepted for publication in Phys. Rev. D | Phys.Rev. D53 (1996) 1703-1705 | 10.1103/PhysRevD.53.1703 | null | hep-ph | null | We calculate the transverse muon polarization in the $K^+_{\mu3}$ process
arising from the Yukawa couplings of charged Higgs boson in a general two-Higgs
doublet model where spontaneous violation of CP is present
| [
{
"created": "Fri, 20 Oct 1995 00:09:10 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Godina",
"J. J.",
""
]
] | We calculate the transverse muon polarization in the $K^+_{\mu3}$ process arising from the Yukawa couplings of charged Higgs boson in a general two-Higgs doublet model where spontaneous violation of CP is present |
1908.05286 | Stefan von Buddenbrock | Stefan von Buddenbrock, Olivier Mattelaer, Michael Spannowsky | Towards a generic implementation of matrix-element maximisation as a
classifier in particle physics | null | null | null | CP3-19-38, MCnet-19-19, ICPP-016, IPPP/19/67 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The so-called matrix-element method (MEM) has long been used successfully as
a classification tool in particle physics searches. In the presence of
invisible final state particles, the traditional MEM typically assigns
probabilities to an event -- based on whether it is more signal or
background-like -- through a phase space integration over all degrees of
freedom of the invisible particles in the process(es). One inherent shortcoming
of the traditional MEM is that the phase space integration can be slow, and
therefore impractical for high multiplicity final states and/or large data
sets. The recent alternative of matrix-element maximisation has recently been
introduced to circumvent this problem, since maximising a highly-dimensional
function can be a far more CPU-efficient task than that of integration. In this
work, matrix-element maximisation is applied to the process of fully-leptonic
top associated Higgs production, where the Higgs boson decays to two
$b$-quarks. A variety of optimisation algorithms are tested in terms of their
performance and speed, and it is explicitly found that the maximisation
technique is far more CPU-efficient than the traditional MEM at the cost of a
slight reduction in performance. An interesting consequence of using
matrix-element maximisation is that the result of the procedure gives an
estimate of the four-momenta for the invisible particles in the event. As a
result, the idea of using these estimates as input information for more
complicated tools is discussed with potential prospects for future developments
of the method.
| [
{
"created": "Wed, 14 Aug 2019 18:00:39 GMT",
"version": "v1"
},
{
"created": "Fri, 23 Aug 2019 10:50:11 GMT",
"version": "v2"
}
] | 2019-08-26 | [
[
"von Buddenbrock",
"Stefan",
""
],
[
"Mattelaer",
"Olivier",
""
],
[
"Spannowsky",
"Michael",
""
]
] | The so-called matrix-element method (MEM) has long been used successfully as a classification tool in particle physics searches. In the presence of invisible final state particles, the traditional MEM typically assigns probabilities to an event -- based on whether it is more signal or background-like -- through a phase space integration over all degrees of freedom of the invisible particles in the process(es). One inherent shortcoming of the traditional MEM is that the phase space integration can be slow, and therefore impractical for high multiplicity final states and/or large data sets. The recent alternative of matrix-element maximisation has recently been introduced to circumvent this problem, since maximising a highly-dimensional function can be a far more CPU-efficient task than that of integration. In this work, matrix-element maximisation is applied to the process of fully-leptonic top associated Higgs production, where the Higgs boson decays to two $b$-quarks. A variety of optimisation algorithms are tested in terms of their performance and speed, and it is explicitly found that the maximisation technique is far more CPU-efficient than the traditional MEM at the cost of a slight reduction in performance. An interesting consequence of using matrix-element maximisation is that the result of the procedure gives an estimate of the four-momenta for the invisible particles in the event. As a result, the idea of using these estimates as input information for more complicated tools is discussed with potential prospects for future developments of the method. |
hep-ph/0602115 | Tatsu Takeuchi | Minako Honda, Yee Kao, Naotoshi Okamura, and Tatsu Takeuchi | A Simple Parameterization of Matter Effects on Neutrino Oscillations | 73 pages REVTeX4, 84 eps figures | null | null | OCHA-PP-252, YITP-05-52, VPI-IPPAP-06-01 | hep-ph | null | We present simple analytical approximations to matter-effect corrected
effective neutrino mixing-angles and effective mass-squared-differences. The
expressions clarify the dependence of oscillation probabilities in matter to
the mixing angles and mass-squared-differences in vacuum, and are useful for
analyzing long-baseline neutrino oscillation experiments.
| [
{
"created": "Mon, 13 Feb 2006 19:33:28 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Honda",
"Minako",
""
],
[
"Kao",
"Yee",
""
],
[
"Okamura",
"Naotoshi",
""
],
[
"Takeuchi",
"Tatsu",
""
]
] | We present simple analytical approximations to matter-effect corrected effective neutrino mixing-angles and effective mass-squared-differences. The expressions clarify the dependence of oscillation probabilities in matter to the mixing angles and mass-squared-differences in vacuum, and are useful for analyzing long-baseline neutrino oscillation experiments. |
1312.5093 | Alka Upadhyay | M. Batra, A. Upadhyay | Octet magnetic Moments and their sum rules in statistical model | Proceedings of DAE symposium, vol. 58,2013 | null | null | null | hep-ph | http://creativecommons.org/licenses/by/3.0/ | The statistical model is implemented to find the magnetic moments of all
octet baryons. The well-known sum rules like GMO and CG sum rules has been
checked in order to check the consistency of our approach. The small
discrepancy between the results suggests the importance of breaking in SU(3)
symmetry.
| [
{
"created": "Wed, 18 Dec 2013 10:46:14 GMT",
"version": "v1"
}
] | 2013-12-19 | [
[
"Batra",
"M.",
""
],
[
"Upadhyay",
"A.",
""
]
] | The statistical model is implemented to find the magnetic moments of all octet baryons. The well-known sum rules like GMO and CG sum rules has been checked in order to check the consistency of our approach. The small discrepancy between the results suggests the importance of breaking in SU(3) symmetry. |
1511.07436 | Daniel Schmeier | Jordy de Vries, Herbi K. Dreiner, Daniel Schmeier | R-Parity Violation and Light Neutralinos at SHiP and the LHC | 19 pages, 11 figures, 8 tables, some overlap with
http://arxiv.org/abs/1504.04855 | Phys. Rev. D 94, 035006 (2016) | 10.1103/PhysRevD.94.035006 | BONN-TH-2015-12 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the sensitivity of the proposed SHiP experiment to the LQD operator
in R-parity violating supersymmetric theories. We focus on single neutralino
production via rare meson decays and the observation of downstream neutralino
decays into charged mesons inside the SHiP decay chamber. We provide a generic
list of effective operators and decay width formulae for any LQD coupling and
show the resulting expected SHiP sensitivity for a widespread list of benchmark
scenarios via numerical simulations. We compare this sensitivity to expected
limits from testing the same decay topology at the LHC with ATLAS.
| [
{
"created": "Mon, 23 Nov 2015 21:00:04 GMT",
"version": "v1"
}
] | 2016-08-17 | [
[
"de Vries",
"Jordy",
""
],
[
"Dreiner",
"Herbi K.",
""
],
[
"Schmeier",
"Daniel",
""
]
] | We study the sensitivity of the proposed SHiP experiment to the LQD operator in R-parity violating supersymmetric theories. We focus on single neutralino production via rare meson decays and the observation of downstream neutralino decays into charged mesons inside the SHiP decay chamber. We provide a generic list of effective operators and decay width formulae for any LQD coupling and show the resulting expected SHiP sensitivity for a widespread list of benchmark scenarios via numerical simulations. We compare this sensitivity to expected limits from testing the same decay topology at the LHC with ATLAS. |
1501.06346 | Zhen-hua Zhao | Zhi-zhong Xing, Zhen-hua Zhao | On the four-zero texture of quark mass matrices and its stability | 33 pages, 4 figures, minor comments added, version to appear in Nucl.
Phys. B | Nucl. Phys. B 897, 302 (2015) | 10.1016/j.nuclphysb.2015.05.027 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We carry out a new study of quark mass matrices $M^{}_{\rm u}$ (up-type) and
$M^{}_{\rm d}$ (down-type) which are Hermitian and have four zero entries, and
find a new part of the parameter space which was missed in the previous works.
We identify two more specific four-zero patterns of $M^{}_{\rm u}$ and
$M^{}_{\rm d}$ with fewer free parameters, and present two toy flavor-symmetry
models which can help realize such special and interesting quark flavor
structures. We also show that the texture zeros of $M^{}_{\rm u}$ and
$M^{}_{\rm d}$ are essentially stable against the evolution of energy scales in
an analytical way by using the one-loop renormalization-group equations.
| [
{
"created": "Mon, 26 Jan 2015 11:42:13 GMT",
"version": "v1"
},
{
"created": "Thu, 4 Jun 2015 01:00:51 GMT",
"version": "v2"
}
] | 2015-06-08 | [
[
"Xing",
"Zhi-zhong",
""
],
[
"Zhao",
"Zhen-hua",
""
]
] | We carry out a new study of quark mass matrices $M^{}_{\rm u}$ (up-type) and $M^{}_{\rm d}$ (down-type) which are Hermitian and have four zero entries, and find a new part of the parameter space which was missed in the previous works. We identify two more specific four-zero patterns of $M^{}_{\rm u}$ and $M^{}_{\rm d}$ with fewer free parameters, and present two toy flavor-symmetry models which can help realize such special and interesting quark flavor structures. We also show that the texture zeros of $M^{}_{\rm u}$ and $M^{}_{\rm d}$ are essentially stable against the evolution of energy scales in an analytical way by using the one-loop renormalization-group equations. |
2408.06738 | Hsiang-nan Li | Hsiang-nan Li | Dispersive analysis of excited glueball states | 15 pages, 5 figures. arXiv admin note: text overlap with
arXiv:2109.04956 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Motivated by the determination for the spin-parity quantum numbers of the
$X(2370)$ meson at BESIII, we extend our dispersive analysis on hadronic ground
states to excited states. The idea is to start with the dispersion relation
which a correlation function obeys, and subtract the known ground-state
contribution from the involved spectral density. Solving the resultant
dispersion relation as an inverse problem with available
operator-product-expansion inputs, we extract excited-state masses from the
subtracted spectral density. This formalism is verified by means of the
application to the series of $\rho$ resonances, which establishes the
$\rho(770)$, $\rho(1450)$ and $\rho(1700)$ mesons one by one under the
sequential subtraction procedure. Our previous study has suggested the
admixture of the $f_0(1370)$, $f_0(1500)$ and $f_0(1710)$ mesons (the
$\eta(1760)$ meson) to be the lightest scalar (pseudoscalar) glueball. The
present work predicts that the $f_0(2200)$ ($X(2370)$) meson is the first
excited scalar (pseudoscalar) glueball.
| [
{
"created": "Tue, 13 Aug 2024 08:55:32 GMT",
"version": "v1"
}
] | 2024-08-14 | [
[
"Li",
"Hsiang-nan",
""
]
] | Motivated by the determination for the spin-parity quantum numbers of the $X(2370)$ meson at BESIII, we extend our dispersive analysis on hadronic ground states to excited states. The idea is to start with the dispersion relation which a correlation function obeys, and subtract the known ground-state contribution from the involved spectral density. Solving the resultant dispersion relation as an inverse problem with available operator-product-expansion inputs, we extract excited-state masses from the subtracted spectral density. This formalism is verified by means of the application to the series of $\rho$ resonances, which establishes the $\rho(770)$, $\rho(1450)$ and $\rho(1700)$ mesons one by one under the sequential subtraction procedure. Our previous study has suggested the admixture of the $f_0(1370)$, $f_0(1500)$ and $f_0(1710)$ mesons (the $\eta(1760)$ meson) to be the lightest scalar (pseudoscalar) glueball. The present work predicts that the $f_0(2200)$ ($X(2370)$) meson is the first excited scalar (pseudoscalar) glueball. |
2002.12442 | Jared Reiten | Jared Reiten | The dijet mass distribution in heavy ion collisions | 6 pages, 4 figures; Proceedings of the XLIX International Symposium
on Multiparticle Dynamics | null | 10.1051/epjconf/202023505006 | null | hep-ph hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In these proceedings, we review the production of both light and heavy flavor
dijets in heavy ion collisions and highlight a promising observable to expose
their distinct signatures. We propose the modification of dijet invariant mass
distributions in heavy ion collisions as a novel observable that exhibits
striking sensitivity to the quark-gluon plasma transport properties and heavy
quark mass effects on in-medium parton showers. This observable has the
advantage of amplifying the effects of jet quenching in contrast to
conventional observables, such as the dijet momentum imbalance shift, which
involve cancellations of such effects and, hence, result in less pronounced
signals. Predictions are presented for Au+Au collisions at $\sqrt{s_{NN}}$ =
200 GeV to guide the future sPHENIX program at the Relativistic Heavy Ion
Collider.
| [
{
"created": "Thu, 27 Feb 2020 21:12:57 GMT",
"version": "v1"
}
] | 2020-07-15 | [
[
"Reiten",
"Jared",
""
]
] | In these proceedings, we review the production of both light and heavy flavor dijets in heavy ion collisions and highlight a promising observable to expose their distinct signatures. We propose the modification of dijet invariant mass distributions in heavy ion collisions as a novel observable that exhibits striking sensitivity to the quark-gluon plasma transport properties and heavy quark mass effects on in-medium parton showers. This observable has the advantage of amplifying the effects of jet quenching in contrast to conventional observables, such as the dijet momentum imbalance shift, which involve cancellations of such effects and, hence, result in less pronounced signals. Predictions are presented for Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV to guide the future sPHENIX program at the Relativistic Heavy Ion Collider. |
hep-ph/9612384 | Steve Godfrey | Stephen Godfrey | Search Limits for Extra Neutral Gauge Bosons at High Energy Lepton
Colliders | Latex2e file uses snow2e.cls, epsfig, 3 postscript figures, to appear
in the Proceedings of the 1996 DPF/DPB Summer Study on New Directions for
High Energy Physics - Snowmass96, Snowmass, CO, 25 June - 12 July, 1996 | ECONF C960625:NEW138,1996 | null | OCIP/C-96-6 | hep-ph | null | We study and compare the discovery potential for heavy neutral gauge bosons
(Z') at the various $e^+e^-$ and $\mu^+\mu^-$ colliders that have been
proposed. Typical search limits for the e^+e^- colliders are 2-10 times sqrt{s}
with the large variation reflecting the model dependence of the limits. The
search limits for the mu^+ mu^- colliders are slightly lower. Polarization and
flavour tagging are important in realizing the highest discovery limits
possible. Because the search limits are based on indirect inferences of
deviations from standard model predictions, they are sensitive to systematic
errors.
| [
{
"created": "Tue, 17 Dec 1996 14:43:12 GMT",
"version": "v1"
}
] | 2011-04-15 | [
[
"Godfrey",
"Stephen",
""
]
] | We study and compare the discovery potential for heavy neutral gauge bosons (Z') at the various $e^+e^-$ and $\mu^+\mu^-$ colliders that have been proposed. Typical search limits for the e^+e^- colliders are 2-10 times sqrt{s} with the large variation reflecting the model dependence of the limits. The search limits for the mu^+ mu^- colliders are slightly lower. Polarization and flavour tagging are important in realizing the highest discovery limits possible. Because the search limits are based on indirect inferences of deviations from standard model predictions, they are sensitive to systematic errors. |
hep-ph/0506162 | Carsten Greiner | C. Greiner and Z. Xu | Thermalization of gluons and onset of collectivity at RHIC due to gg
<--> ggg interactions | 7 pages, revtex, 6 figures, to appear in the proceedings of the 43rd
International Winter Meeting on Nuclear Physics, Bormio, Italy, 13 Mar - 20
Mar 2005 | null | null | null | hep-ph | null | A number of promising results of a new 3+1 dimensional Monte Carlo parton
cascade including inelastic multiplication processes (gg <--> ggg) are
elaborated: (1) thermalization and chemical saturation; (2) the onset of
longitudinal hydrodynamical expansion; (3) the build up of elliptic flow. We
first briefly outline the basic idea of the algorithm. Full simulations are
done with initial conditions for the kinetic partons via minijets or with ones
stemming from a color glass condensate. The inclusion of the inelastic channels
leads to a very fast kinetic equilibration and also to an early creation of
pressure.
| [
{
"created": "Thu, 16 Jun 2005 11:11:21 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Greiner",
"C.",
""
],
[
"Xu",
"Z.",
""
]
] | A number of promising results of a new 3+1 dimensional Monte Carlo parton cascade including inelastic multiplication processes (gg <--> ggg) are elaborated: (1) thermalization and chemical saturation; (2) the onset of longitudinal hydrodynamical expansion; (3) the build up of elliptic flow. We first briefly outline the basic idea of the algorithm. Full simulations are done with initial conditions for the kinetic partons via minijets or with ones stemming from a color glass condensate. The inclusion of the inelastic channels leads to a very fast kinetic equilibration and also to an early creation of pressure. |
1910.07552 | Greg Jackson | Greg Jackson | Two-loop thermal spectral functions with general kinematics | 62 pages, v2: minor fixes and clarifications | Phys. Rev. D 100, 116019 (2019) | 10.1103/PhysRevD.100.116019 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Spectral functions at finite temperature and two-loop order are investigated,
for a medium consisting of massless particles. We consider them in the timelike
and spacelike domains, allowing the propagating particles to be any valid
combination of bosons and fermions. Divergences (if present) are analytically
derived and set aside for the remaining finite part to be calculated
numerically. To illustrate the utility of these 'master' functions, we consider
transverse and longitudinal parts of the QCD vector channel spectral function.
| [
{
"created": "Wed, 16 Oct 2019 18:05:09 GMT",
"version": "v1"
},
{
"created": "Mon, 23 Dec 2019 12:54:48 GMT",
"version": "v2"
}
] | 2019-12-25 | [
[
"Jackson",
"Greg",
""
]
] | Spectral functions at finite temperature and two-loop order are investigated, for a medium consisting of massless particles. We consider them in the timelike and spacelike domains, allowing the propagating particles to be any valid combination of bosons and fermions. Divergences (if present) are analytically derived and set aside for the remaining finite part to be calculated numerically. To illustrate the utility of these 'master' functions, we consider transverse and longitudinal parts of the QCD vector channel spectral function. |
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