id stringlengths 9 14 | submitter stringlengths 1 56 ⌀ | authors stringlengths 5 7.68k | title stringlengths 3 299 | comments stringlengths 1 1.15k ⌀ | journal-ref stringlengths 9 298 ⌀ | doi stringlengths 12 97 ⌀ | report-no stringlengths 3 341 ⌀ | categories stringclasses 869 values | license stringclasses 9 values | orig_abstract stringlengths 16 2.44k | versions listlengths 1 39 | update_date stringlengths 10 10 | authors_parsed listlengths 1 565 | abstract stringlengths 13 2.44k |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1808.00565 | Andrea Signori | Alberto Accardi (Hampton U. and Jefferson Lab), Andrea Signori
(Jefferson Lab) | Transversity in inclusive DIS and novel TMD sum rules | Contribution to proceedings of DIS 2018 | null | null | JLAB-THY-18-2774 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A reanalysis of collinear factorization for inclusive Deep Inelastic
Scattering shows that a novel, non perturbative spin-flip term associated with
the invariant mass of the produced hadrons couples, at large enough Bjorken
$x_B$, to the target's transversity distribution function. The resulting new
contribution to the $g_2$ structure function can potentially explain the
discrepancy between recent calculations and fits of this quantity. The new term
also breaks the Burkhardt-Cottingham sum rule, now featuring an interplay
between the $g_2$ and $h_1$ functions that calls for a re-examination of their
small-$x$ behavior. As part of the calculation leading to these results, a new
set of TMD sum rules is derived by relating the single-hadron quark
fragmentation correlator to the fully dressed quark propagator by means of
integration over the hadronic momenta and spins. A complete set of momentum sum
rules is obtained for transverse-momentum-dependent quark fragmentation
functions up to next-to-leading twist.
| [
{
"created": "Wed, 1 Aug 2018 21:03:31 GMT",
"version": "v1"
}
] | 2018-08-03 | [
[
"Accardi",
"Alberto",
"",
"Hampton U. and Jefferson Lab"
],
[
"Signori",
"Andrea",
"",
"Jefferson Lab"
]
] | A reanalysis of collinear factorization for inclusive Deep Inelastic Scattering shows that a novel, non perturbative spin-flip term associated with the invariant mass of the produced hadrons couples, at large enough Bjorken $x_B$, to the target's transversity distribution function. The resulting new contribution to the $g_2$ structure function can potentially explain the discrepancy between recent calculations and fits of this quantity. The new term also breaks the Burkhardt-Cottingham sum rule, now featuring an interplay between the $g_2$ and $h_1$ functions that calls for a re-examination of their small-$x$ behavior. As part of the calculation leading to these results, a new set of TMD sum rules is derived by relating the single-hadron quark fragmentation correlator to the fully dressed quark propagator by means of integration over the hadronic momenta and spins. A complete set of momentum sum rules is obtained for transverse-momentum-dependent quark fragmentation functions up to next-to-leading twist. |
2004.02885 | Nicholas Rodd | Grant N. Remmen, Nicholas L. Rodd | Flavor Constraints from Unitarity and Analyticity | 7 pages, 1 figure; v3 corrected a sign in the definition of several
operators | Phys. Rev. Lett. 125, 081601 (2020) | 10.1103/PhysRevLett.125.081601 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We use unitarity and analyticity of scattering amplitudes to constrain
fermionic operators in the standard model effective field theory. For
four-fermion operators at mass dimension 8, we scatter flavor superpositions in
fixed standard model representations and find the Wilson coefficients to be
constrained so that their contraction with any pair of pure density matrices is
positive. These constraints imply that flavor-violating couplings are
upper-bounded by their flavor-conserving cousins. For instance, LEP data
already appears to preclude certain operators in upcoming $\mu \to 3e$
measurements.
| [
{
"created": "Mon, 6 Apr 2020 18:00:00 GMT",
"version": "v1"
},
{
"created": "Fri, 21 Aug 2020 17:36:34 GMT",
"version": "v2"
},
{
"created": "Tue, 31 Aug 2021 22:44:25 GMT",
"version": "v3"
}
] | 2021-09-02 | [
[
"Remmen",
"Grant N.",
""
],
[
"Rodd",
"Nicholas L.",
""
]
] | We use unitarity and analyticity of scattering amplitudes to constrain fermionic operators in the standard model effective field theory. For four-fermion operators at mass dimension 8, we scatter flavor superpositions in fixed standard model representations and find the Wilson coefficients to be constrained so that their contraction with any pair of pure density matrices is positive. These constraints imply that flavor-violating couplings are upper-bounded by their flavor-conserving cousins. For instance, LEP data already appears to preclude certain operators in upcoming $\mu \to 3e$ measurements. |
0804.3047 | Feng Yuan | Feng Yuan | Single Spin Asymmetry in Inclusive Hadron Production in pp Scattering
from Collins Mechanism | references corrected | Phys.Lett.B666:44-47,2008 | 10.1016/j.physletb.2008.06.066 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the Collins mechanism contribution to the single transverse spin
asymmetry in inclusive hadron production in pp scattering p^{\uparrow}p\to \pi
X from the leading jet fragmentation. The azimuthal asymmetric distribution of
hadron in the jet leads to a single spin asymmetry for the produced hadron in
the Lab frame. The effect is evaluated in a transverse momentum dependent model
that takes into account the transverse momentum dependence in the fragmentation
process. We find the asymmetry is comparable in size to the experimental
observation at RHIC at \sqrt{s}=200 GeV.
| [
{
"created": "Fri, 18 Apr 2008 15:39:56 GMT",
"version": "v1"
},
{
"created": "Mon, 21 Apr 2008 18:11:16 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Yuan",
"Feng",
""
]
] | We study the Collins mechanism contribution to the single transverse spin asymmetry in inclusive hadron production in pp scattering p^{\uparrow}p\to \pi X from the leading jet fragmentation. The azimuthal asymmetric distribution of hadron in the jet leads to a single spin asymmetry for the produced hadron in the Lab frame. The effect is evaluated in a transverse momentum dependent model that takes into account the transverse momentum dependence in the fragmentation process. We find the asymmetry is comparable in size to the experimental observation at RHIC at \sqrt{s}=200 GeV. |
hep-ph/0403224 | Csaba Balazs | C. Balazs, M. Carena and C.E.M. Wagner | Dark Matter, Light Stops and Electroweak Baryogenesis | 24 pages, 8 figures; version published in Phys.Rev.D | Phys.Rev.D70:015007,2004 | 10.1103/PhysRevD.70.015007 | ANL-HEP-PR-04-27, EFI-04-08, FERMILAB-PUB-04/034-T | hep-ph | null | We examine the neutralino relic density in the presence of a light top
squark, such as the one required for the realization of the electroweak
baryogenesis mechanism, within the minimal supersymmetric standard model. We
show that there are three clearly distinguishable regions of parameter space,
where the relic density is consistent with WMAP and other cosmological data.
These regions are characterized by annihilation cross sections mediated by
either light Higgs bosons, Z bosons, or by the co-annihilation with the
lightest stop. Tevatron collider experiments can test the presence of the light
stop in most of the parameter space. In the co-annihilation region, however,
the mass difference between the light stop and the lightest neutralino varies
between 15 and 30 GeV, presenting an interesting challenge for stop searches at
hadron colliders. We present the prospects for direct detection of dark matter,
which provides a complementary way of testing this scenario. We also derive the
required structure of the high energy soft supersymmetry breaking mass
parameters where the neutralino is a dark matter candidate and the stop
spectrum is consistent with electroweak baryogenesis and the present bounds on
the lightest Higgs mass.
| [
{
"created": "Sat, 20 Mar 2004 00:34:26 GMT",
"version": "v1"
},
{
"created": "Tue, 3 Aug 2004 17:19:17 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Balazs",
"C.",
""
],
[
"Carena",
"M.",
""
],
[
"Wagner",
"C. E. M.",
""
]
] | We examine the neutralino relic density in the presence of a light top squark, such as the one required for the realization of the electroweak baryogenesis mechanism, within the minimal supersymmetric standard model. We show that there are three clearly distinguishable regions of parameter space, where the relic density is consistent with WMAP and other cosmological data. These regions are characterized by annihilation cross sections mediated by either light Higgs bosons, Z bosons, or by the co-annihilation with the lightest stop. Tevatron collider experiments can test the presence of the light stop in most of the parameter space. In the co-annihilation region, however, the mass difference between the light stop and the lightest neutralino varies between 15 and 30 GeV, presenting an interesting challenge for stop searches at hadron colliders. We present the prospects for direct detection of dark matter, which provides a complementary way of testing this scenario. We also derive the required structure of the high energy soft supersymmetry breaking mass parameters where the neutralino is a dark matter candidate and the stop spectrum is consistent with electroweak baryogenesis and the present bounds on the lightest Higgs mass. |
hep-ph/0205188 | Dr. N. G. Kelkar | N. G. Kelkar | Time advancement in resonance regions of pi-N scattering | 10 pages, LaTex, including 4 figures | J.Phys. G29 (2003) L1-L8 | null | null | hep-ph hep-ex nucl-th | null | We evaluate the time delay in some of the established resonance regions of
$\pi N$ elastic scattering. In addition to the positive peaks corresponding to
resonances, we identify broad regions of negative time delay or time
advancement which restrict the energy ranges within which the resonances can be
located.
| [
{
"created": "Fri, 17 May 2002 10:37:37 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Kelkar",
"N. G.",
""
]
] | We evaluate the time delay in some of the established resonance regions of $\pi N$ elastic scattering. In addition to the positive peaks corresponding to resonances, we identify broad regions of negative time delay or time advancement which restrict the energy ranges within which the resonances can be located. |
2106.08869 | Nuno Filipe Castro | L. Apolin\'ario, N. F. Castro, M. Crispim Rom\~ao, J. G. Milhano, R.
Pedro, F. C. R. Peres | Deep Learning for the Classification of Quenched Jets | 36 pages, 21 figures, 3 tables | JHEP11 (2021) 219 | 10.1007/JHEP11(2021)219 | null | hep-ph hep-ex physics.comp-ph | http://creativecommons.org/licenses/by/4.0/ | An important aspect of the study of Quark-Gluon Plasma (QGP) in
ultra-relativistic collisions of heavy ions is the ability to identify, in
experimental data, a subset of the jets that were strongly modified by the
interaction with the QGP. In this work, we propose studying deep learning
techniques for this purpose. Samples of $Z+$jet events were simulated in vacuum
and medium and used to train deep neural networks with the objective of
discriminating between medium- and vacuum-like jets. Dedicated Convolutional
Neural Networks, Dense Neural Networks and Recurrent Neural Networks were
developed and trained, and their performance was studied. Our results show the
potential of these techniques for the identification of jet quenching effects
induced by the presence of the QGP.
| [
{
"created": "Wed, 16 Jun 2021 15:43:12 GMT",
"version": "v1"
}
] | 2021-12-01 | [
[
"Apolinário",
"L.",
""
],
[
"Castro",
"N. F.",
""
],
[
"Romão",
"M. Crispim",
""
],
[
"Milhano",
"J. G.",
""
],
[
"Pedro",
"R.",
""
],
[
"Peres",
"F. C. R.",
""
]
] | An important aspect of the study of Quark-Gluon Plasma (QGP) in ultra-relativistic collisions of heavy ions is the ability to identify, in experimental data, a subset of the jets that were strongly modified by the interaction with the QGP. In this work, we propose studying deep learning techniques for this purpose. Samples of $Z+$jet events were simulated in vacuum and medium and used to train deep neural networks with the objective of discriminating between medium- and vacuum-like jets. Dedicated Convolutional Neural Networks, Dense Neural Networks and Recurrent Neural Networks were developed and trained, and their performance was studied. Our results show the potential of these techniques for the identification of jet quenching effects induced by the presence of the QGP. |
hep-ph/0103303 | Fabio L. Braghin | F\'abio L. Braghin and Fernando S. Navarra | Space-time evolution of the \lap model: classical and quantum aspects | 12 pages latex plus five figures .eps. Report:1460/2001IF-USP | Phys.Lett. B508 (2001) 243-250 | 10.1016/S0370-2693(01)00543-3 | null | hep-ph | null | A time dependent variational approach is used to derive the equations of
motion for the \lambda \phi^4 model. The simultaneous evolution of the quantum
fluctuations and of the classical part of the field is considered in a lattice
of 1+1 dimensions. Different initial conditions corresponding to non
equilibrium situations are considered and evolved in time. Such high energy
localized configurations expand in the lattice by ``bumps'' which may change
with time. The quantum fluctuations make the peaks be smoother and the
expansion faster.
| [
{
"created": "Wed, 28 Mar 2001 18:15:45 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Braghin",
"Fábio L.",
""
],
[
"Navarra",
"Fernando S.",
""
]
] | A time dependent variational approach is used to derive the equations of motion for the \lambda \phi^4 model. The simultaneous evolution of the quantum fluctuations and of the classical part of the field is considered in a lattice of 1+1 dimensions. Different initial conditions corresponding to non equilibrium situations are considered and evolved in time. Such high energy localized configurations expand in the lattice by ``bumps'' which may change with time. The quantum fluctuations make the peaks be smoother and the expansion faster. |
1604.01731 | A. D. Polosa | A. Ali, L. Maiani, A.D. Polosa, V. Riquer | B_c^+- decays into tetraquarks | 6 pages, 1 figure | Phys. Rev. D 94, 034036 (2016) | 10.1103/PhysRevD.94.034036 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The recent observation by the D0 collaboration of a narrow structure X(5568)
consisting of four different quark flavors bdus, has not been confirmed by
LHCb. More data and dedicated analyses are needed to cover a larger mass range.
In the tightly bound diquark model, we estimate the lightest bdus, 0^+
tetraquark at a mass of about 5770 MeV, approximately 200 MeV above the
reported X(5568), and just 7 MeV below the B Kbar threshold. The charged
tetraquark is accompanied by I=1 and I=0 neutral partners almost degenerate in
mass. A bdus, S-wave, 1^+ quartet at 5820 MeV is implied as well. In the charm
sector, cdus, 0^+ and 1^+ tetraquarks are predicted at 2365 MeV and 2501 MeV,
about 40-50 MeV heavier than D_{s0}(2317) and D_{s1}(2460). bdus tetraquarks
can be searched in the hadronic debris of a jet initiated by a b. However, some
of them may also be produced in B_c decays. The proposed discovery modes of
S-wave tetraquarks are B_c --> X_{b0} + pi with the subsequent decays X_{b0}
--> B_s + pi, giving rise to final states such as B_s pi^+ pi^0. We also
emphasize the importance of B_c decays as a source of bound hidden charm
tetraquarks, such as B_c --> X(3872) + pi.
| [
{
"created": "Wed, 6 Apr 2016 19:02:20 GMT",
"version": "v1"
}
] | 2016-08-31 | [
[
"Ali",
"A.",
""
],
[
"Maiani",
"L.",
""
],
[
"Polosa",
"A. D.",
""
],
[
"Riquer",
"V.",
""
]
] | The recent observation by the D0 collaboration of a narrow structure X(5568) consisting of four different quark flavors bdus, has not been confirmed by LHCb. More data and dedicated analyses are needed to cover a larger mass range. In the tightly bound diquark model, we estimate the lightest bdus, 0^+ tetraquark at a mass of about 5770 MeV, approximately 200 MeV above the reported X(5568), and just 7 MeV below the B Kbar threshold. The charged tetraquark is accompanied by I=1 and I=0 neutral partners almost degenerate in mass. A bdus, S-wave, 1^+ quartet at 5820 MeV is implied as well. In the charm sector, cdus, 0^+ and 1^+ tetraquarks are predicted at 2365 MeV and 2501 MeV, about 40-50 MeV heavier than D_{s0}(2317) and D_{s1}(2460). bdus tetraquarks can be searched in the hadronic debris of a jet initiated by a b. However, some of them may also be produced in B_c decays. The proposed discovery modes of S-wave tetraquarks are B_c --> X_{b0} + pi with the subsequent decays X_{b0} --> B_s + pi, giving rise to final states such as B_s pi^+ pi^0. We also emphasize the importance of B_c decays as a source of bound hidden charm tetraquarks, such as B_c --> X(3872) + pi. |
hep-ph/9704360 | Levai Peter | Peter Levai (KFKI RMKI) and Ramona Vogt (LBNL and U.C. Davis) | Thermal charm production by massive gluons and quarks | 19 pages in Latex and 9 Postscript figures | Phys.Rev.C56:2707-2717,1997 | 10.1103/PhysRevC.56.2707 | LBNL-39984 | hep-ph | null | We investigate charm production in an equilibrated quark-gluon plasma
produced in heavy-ion collisions at RHIC and LHC. Effective quark and gluon
masses are introduced from thermal QCD calculations. Assuming a Bjorken-type
longitudinal expansion and including the influence of temperature dependent
masses on the expansion, we determine the total number of c\bar{c} pairs
produced in the quark-gluon plasma phase. We calculate the charm production
rate at leading order with massive gluons and quarks and compare our result to
charm production by massless partons. We consider two different scenarios for
the initial conditions, a parton gas with a rather long kinetic equilibration
time and a minijet gas with a short equilibration time. In a parton gas,
assuming m_c=1.2 GeV, we obtain a substantial enhancement over the thermal
charm rate from massless quarks and gluons, up to 4.9 secondary charm quark
pairs in Au+Au collisions at RHIC and 245 charm pairs in Pb+Pb collisions at
the LHC.
| [
{
"created": "Sun, 20 Apr 1997 12:31:04 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Levai",
"Peter",
"",
"KFKI RMKI"
],
[
"Vogt",
"Ramona",
"",
"LBNL and U.C. Davis"
]
] | We investigate charm production in an equilibrated quark-gluon plasma produced in heavy-ion collisions at RHIC and LHC. Effective quark and gluon masses are introduced from thermal QCD calculations. Assuming a Bjorken-type longitudinal expansion and including the influence of temperature dependent masses on the expansion, we determine the total number of c\bar{c} pairs produced in the quark-gluon plasma phase. We calculate the charm production rate at leading order with massive gluons and quarks and compare our result to charm production by massless partons. We consider two different scenarios for the initial conditions, a parton gas with a rather long kinetic equilibration time and a minijet gas with a short equilibration time. In a parton gas, assuming m_c=1.2 GeV, we obtain a substantial enhancement over the thermal charm rate from massless quarks and gluons, up to 4.9 secondary charm quark pairs in Au+Au collisions at RHIC and 245 charm pairs in Pb+Pb collisions at the LHC. |
hep-ph/0610157 | Leif Lonnblad | Emil Avsar, Gosta Gustafson and Leif Lonnblad | Small-x Dipole Evolution Beyond the Large-N_c Limit | null | JHEP 0701:012,2007 | 10.1088/1126-6708/2007/01/012 | null | hep-ph | null | We present a method to include colour-suppressed effects in the Mueller
dipole picture. The model consistently includes saturation effects both in the
evolution of dipoles and in the interactions of dipoles with a target in a
frame-independent way.
When implemented in a Monte Carlo simulation together with our previous model
of energy--momentum conservation and a simple dipole description of initial
state protons and virtual photons, the model is able to reproduce to a
satisfactory degree both the gamma*-p cross sections as measured at HERA as
well as the total p-p cross section all the way from ISR energies to the
Tevatron and beyond.
| [
{
"created": "Thu, 12 Oct 2006 21:24:00 GMT",
"version": "v1"
},
{
"created": "Wed, 6 Dec 2006 09:29:26 GMT",
"version": "v2"
}
] | 2010-10-27 | [
[
"Avsar",
"Emil",
""
],
[
"Gustafson",
"Gosta",
""
],
[
"Lonnblad",
"Leif",
""
]
] | We present a method to include colour-suppressed effects in the Mueller dipole picture. The model consistently includes saturation effects both in the evolution of dipoles and in the interactions of dipoles with a target in a frame-independent way. When implemented in a Monte Carlo simulation together with our previous model of energy--momentum conservation and a simple dipole description of initial state protons and virtual photons, the model is able to reproduce to a satisfactory degree both the gamma*-p cross sections as measured at HERA as well as the total p-p cross section all the way from ISR energies to the Tevatron and beyond. |
1211.1862 | Chuwen Xiao | C. W. Xiao and E. Oset | Three methods to detect the predicted $D \bar{D}$ scalar meson X(3700) | extra experimental information added | null | 10.1140/epja/i2013-13052-5 | null | hep-ph nucl-th | http://creativecommons.org/licenses/by/3.0/ | In analogy to the f_0(500), which appears as a $\pi \pi $ resonance in chiral
unitary theory, and the f_0(980), which appears as a quasibound $K \bar K$
state, the extension of this approach to the charm sector also predicts a
quasibound $D \bar D $ state with mass around 3720 MeV, named as X(3700), for
which some experimental support is seen in the $e^+ e^- \to J/\psi D \bar D $
reaction close to the $D \bar D $ threshold. In the present work we propose
three different experiments to observe it as a clear peak. The first one is the
radiative decay of the $\psi(3770)$, $\psi(3770) \to \gamma X(3700) \to \gamma
\eta \eta '$. The second one proposes the analogous reaction $\psi(4040) \to
\gamma X(3700) \to \gamma \eta \eta '$ and the third reaction is the $e^+ e^-
\to J/\psi X(3700) \to J/\psi \eta \eta '$. Neat peaks are predicted for all
the reactions and the calculated rates are found within measurable range in
present facilities.
| [
{
"created": "Thu, 8 Nov 2012 14:22:50 GMT",
"version": "v1"
},
{
"created": "Thu, 15 Nov 2012 13:54:25 GMT",
"version": "v2"
}
] | 2015-06-12 | [
[
"Xiao",
"C. W.",
""
],
[
"Oset",
"E.",
""
]
] | In analogy to the f_0(500), which appears as a $\pi \pi $ resonance in chiral unitary theory, and the f_0(980), which appears as a quasibound $K \bar K$ state, the extension of this approach to the charm sector also predicts a quasibound $D \bar D $ state with mass around 3720 MeV, named as X(3700), for which some experimental support is seen in the $e^+ e^- \to J/\psi D \bar D $ reaction close to the $D \bar D $ threshold. In the present work we propose three different experiments to observe it as a clear peak. The first one is the radiative decay of the $\psi(3770)$, $\psi(3770) \to \gamma X(3700) \to \gamma \eta \eta '$. The second one proposes the analogous reaction $\psi(4040) \to \gamma X(3700) \to \gamma \eta \eta '$ and the third reaction is the $e^+ e^- \to J/\psi X(3700) \to J/\psi \eta \eta '$. Neat peaks are predicted for all the reactions and the calculated rates are found within measurable range in present facilities. |
hep-ph/0302184 | Urs Wiedemann | Carlos A. Salgado, Urs Achim Wiedemann | Calculating Quenching Weights | 45 pages LaTeX, 20 eps-figures | Phys.Rev. D68 (2003) 014008 | 10.1103/PhysRevD.68.014008 | CERN-TH/2003-030 | hep-ph nucl-th | null | We calculate the probability (``quenching weight'') that a hard parton
radiates an additional energy fraction due to scattering in spatially extended
QCD matter. This study is based on an exact treatment of finite in-medium path
length, it includes the case of a dynamically expanding medium, and it extends
to the angular dependence of the medium-induced gluon radiation pattern. All
calculations are done in the multiple soft scattering approximation
(Baier-Dokshitzer-Mueller-Peign\'e-Schiff--Zakharov ``BDMPS-Z''-formalism) and
in the single hard scattering approximation (N=1 opacity approximation). By
comparison, we establish a simple relation between transport coefficient, Debye
screening mass and opacity, for which both approximations lead to comparable
results. Together with this paper, a CPU-inexpensive numerical subroutine for
calculating quenching weights is provided electronically. To illustrate its
applications, we discuss the suppression of hadronic transverse momentum
spectra in nucleus-nucleus collisions. Remarkably, the kinematic constraint
resulting from finite in-medium path length reduces significantly the
transverse momentum dependence of the nuclear modification factor, thus leading
to consistency with the data measured at the Relativistic Heavy Ion Collider
(RHIC).
| [
{
"created": "Thu, 20 Feb 2003 12:14:26 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Salgado",
"Carlos A.",
""
],
[
"Wiedemann",
"Urs Achim",
""
]
] | We calculate the probability (``quenching weight'') that a hard parton radiates an additional energy fraction due to scattering in spatially extended QCD matter. This study is based on an exact treatment of finite in-medium path length, it includes the case of a dynamically expanding medium, and it extends to the angular dependence of the medium-induced gluon radiation pattern. All calculations are done in the multiple soft scattering approximation (Baier-Dokshitzer-Mueller-Peign\'e-Schiff--Zakharov ``BDMPS-Z''-formalism) and in the single hard scattering approximation (N=1 opacity approximation). By comparison, we establish a simple relation between transport coefficient, Debye screening mass and opacity, for which both approximations lead to comparable results. Together with this paper, a CPU-inexpensive numerical subroutine for calculating quenching weights is provided electronically. To illustrate its applications, we discuss the suppression of hadronic transverse momentum spectra in nucleus-nucleus collisions. Remarkably, the kinematic constraint resulting from finite in-medium path length reduces significantly the transverse momentum dependence of the nuclear modification factor, thus leading to consistency with the data measured at the Relativistic Heavy Ion Collider (RHIC). |
2008.12792 | Juan Antonio Aguilar-Saavedra | J. A. Aguilar-Saavedra, F. R. Joaquim, J. F. Seabra | Mass Unspecific Supervised Tagging (MUST) for boosted jets | v2: Results and discussion substantially extended, 6 -> 15 pages. v3:
Additional results, 16 pages. Final version in JHEP | null | 10.1007/JHEP03(2021)012 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Jet identification tools are crucial for new physics searches at the LHC and
at future colliders. We introduce the concept of Mass Unspecific Supervised
Tagging (MUST) which relies on considering both jet mass and transverse
momentum varying over wide ranges as input variables - together with jet
substructure observables - of a multivariate tool. This approach not only
provides a single efficient tagger for arbitrary ranges of jet mass and
transverse momentum, but also an optimal solution for the mass correlation
problem inherent to current taggers. By training neural networks, we build
MUST-inspired generic and multi-pronged jet taggers which, when tested with
various new physics signals, clearly outperform the variables commonly used by
experiments to discriminate signal from background. These taggers are also
efficient to spot signals for which they have not been trained. Taggers can
also be built to determine, with a high degree of confidence, the prongness of
a jet, which would be of utmost importance in case a new physics signal is
discovered.
| [
{
"created": "Fri, 28 Aug 2020 18:00:05 GMT",
"version": "v1"
},
{
"created": "Thu, 5 Nov 2020 10:09:00 GMT",
"version": "v2"
},
{
"created": "Tue, 2 Mar 2021 21:48:42 GMT",
"version": "v3"
}
] | 2021-03-17 | [
[
"Aguilar-Saavedra",
"J. A.",
""
],
[
"Joaquim",
"F. R.",
""
],
[
"Seabra",
"J. F.",
""
]
] | Jet identification tools are crucial for new physics searches at the LHC and at future colliders. We introduce the concept of Mass Unspecific Supervised Tagging (MUST) which relies on considering both jet mass and transverse momentum varying over wide ranges as input variables - together with jet substructure observables - of a multivariate tool. This approach not only provides a single efficient tagger for arbitrary ranges of jet mass and transverse momentum, but also an optimal solution for the mass correlation problem inherent to current taggers. By training neural networks, we build MUST-inspired generic and multi-pronged jet taggers which, when tested with various new physics signals, clearly outperform the variables commonly used by experiments to discriminate signal from background. These taggers are also efficient to spot signals for which they have not been trained. Taggers can also be built to determine, with a high degree of confidence, the prongness of a jet, which would be of utmost importance in case a new physics signal is discovered. |
1510.06675 | Ryuji Daido | Ryuji Daido, Naoya Kitajima, Fuminobu Takahashi | Level Crossing between QCD Axion and Axion-Like Particle | 20 pages, 5 figures | Phys. Rev. D 93, 075027 (2016) | 10.1103/PhysRevD.93.075027 | TU-1007, APCTP Pre2015-026, IPMU15-0181 | hep-ph astro-ph.CO hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study a level crossing between the QCD axion and an axion-like particle,
focusing on the recently found phenomenon, the axion roulette, where the
axion-like particle runs along the potential, passing through many crests and
troughs, until it gets trapped in one of the potential minima. We perform
detailed numerical calculations to determine the parameter space where the
axion roulette takes place, and as a result domain walls are likely formed. The
domain wall network without cosmic strings is practically stable, and it is
nothing but a cosmological disaster. In a certain case, one can make domain
walls unstable and decay quickly by introducing an energy bias without spoiling
the Peccei-Quinn solution to the strong CP problem.
| [
{
"created": "Thu, 22 Oct 2015 16:23:45 GMT",
"version": "v1"
}
] | 2016-04-27 | [
[
"Daido",
"Ryuji",
""
],
[
"Kitajima",
"Naoya",
""
],
[
"Takahashi",
"Fuminobu",
""
]
] | We study a level crossing between the QCD axion and an axion-like particle, focusing on the recently found phenomenon, the axion roulette, where the axion-like particle runs along the potential, passing through many crests and troughs, until it gets trapped in one of the potential minima. We perform detailed numerical calculations to determine the parameter space where the axion roulette takes place, and as a result domain walls are likely formed. The domain wall network without cosmic strings is practically stable, and it is nothing but a cosmological disaster. In a certain case, one can make domain walls unstable and decay quickly by introducing an energy bias without spoiling the Peccei-Quinn solution to the strong CP problem. |
hep-ph/0204242 | shunzo Kumano | S. Kumano (Saga University) | Structure functions of the nucleon and nuclei in neutrino reactions | 1+7 pages, LaTeX2e, espcrc2.sty, 6 eps figures. Invited talk given at
the First International Workshop on Neutrino-Nucleus Interactions in the Few
GeV Region, KEK, Tsukuba, Japan, December 13 - 16, 2001. To be published in
Nucl. Phys. B Supplement. Email: kumanos@cc.saga-u.ac.jp,
http://hs.phys.saga-u.ac.jp | Nucl.Phys.Proc.Suppl. 112 (2002) 42-48 | 10.1016/S0920-5632(02)01760-7 | SAGA-HE-185-01 | hep-ph hep-ex nucl-th | null | Determination of parton distribution functions in nuclei is important for
calculating nuclear corrections in oscillation experiments, from which detailed
information should be extracted on neutrino properties. First, nuclear parton
distributions are discussed for explaining high-energy nuclear reaction data.
Possible nuclear modification is explained for valence-quark and antiquark
distributions. It is rather difficult to determine gluon distributions in
nuclei. Next, reversing the topic, we discuss structure functions which could
be investigated by neutrino reactions. Determination of polarized parton
distributions in the nucleon is discussed in polarized neutrino reactions. In
addition, neutrino reactions should be important for finding nuclear
modification of valence-quark distributions at small x if structure function
ratios F_3^A/F_3^D are measured for various nuclei.
| [
{
"created": "Sat, 20 Apr 2002 05:22:43 GMT",
"version": "v1"
},
{
"created": "Fri, 12 Jul 2002 08:10:41 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Kumano",
"S.",
"",
"Saga University"
]
] | Determination of parton distribution functions in nuclei is important for calculating nuclear corrections in oscillation experiments, from which detailed information should be extracted on neutrino properties. First, nuclear parton distributions are discussed for explaining high-energy nuclear reaction data. Possible nuclear modification is explained for valence-quark and antiquark distributions. It is rather difficult to determine gluon distributions in nuclei. Next, reversing the topic, we discuss structure functions which could be investigated by neutrino reactions. Determination of polarized parton distributions in the nucleon is discussed in polarized neutrino reactions. In addition, neutrino reactions should be important for finding nuclear modification of valence-quark distributions at small x if structure function ratios F_3^A/F_3^D are measured for various nuclei. |
0802.3988 | Riccardo Barbieri | Riccardo Barbieri | Signatures of new physics at 14 TeV | 12 pages, talk at the 5th Italian workshop on LHC physics, Perugia,
January 30-February 2, 2008 | null | 10.1393/ncb/i2008-10544-4 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | I give an overview of the ideas and of the problems that orient the
expectations for new physics at the Large Hadron Collider and, whenever I can,
I describe the corresponding signals.
| [
{
"created": "Wed, 27 Feb 2008 10:47:01 GMT",
"version": "v1"
}
] | 2009-11-13 | [
[
"Barbieri",
"Riccardo",
""
]
] | I give an overview of the ideas and of the problems that orient the expectations for new physics at the Large Hadron Collider and, whenever I can, I describe the corresponding signals. |
hep-ph/9806319 | Helmut Satz | Helmut Satz | A Brief History of J/Psi Suppression | 7 pages, latex, two figures (included) | null | null | BI-TP 98/16 | hep-ph | null | Statistical QCD predicts that strongly interacting matter will become
deconfined at high temperatures and/or densities. The aim of high energy
nuclear collisions is to study the onset of deconfinement and the properties of
deconfined media in the laboratory. Hence it is essential to define an
unambiguous and experimentally viable probe for deconfinement. Twelve years
ago, T. Matsui and I proposed that \J~production should constitute such a probe
\cite{M&S}, and I want to sketch here rather briefly the evolution of this idea
in the light of subsequent experimental and theoretical work.
| [
{
"created": "Tue, 9 Jun 1998 15:52:03 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Satz",
"Helmut",
""
]
] | Statistical QCD predicts that strongly interacting matter will become deconfined at high temperatures and/or densities. The aim of high energy nuclear collisions is to study the onset of deconfinement and the properties of deconfined media in the laboratory. Hence it is essential to define an unambiguous and experimentally viable probe for deconfinement. Twelve years ago, T. Matsui and I proposed that \J~production should constitute such a probe \cite{M&S}, and I want to sketch here rather briefly the evolution of this idea in the light of subsequent experimental and theoretical work. |
hep-ph/9304230 | Christopher Arzt | C. Arzt | Reduced Effective Lagrangians | 14 pages, no figures, PHYZZX, report #UM-TH-92-28 | Phys.Lett. B342 (1995) 189-195 | 10.1016/0370-2693(94)01419-D | null | hep-ph | null | Effective Lagrangians, including those that are spontaneously broken, contain
redundant terms. It is shown that the classical equations of motion may be used
to simplify the effective Lagrangian, even when quantum loops are to be
considered.
| [
{
"created": "Thu, 8 Apr 1993 07:45:13 GMT",
"version": "v1"
}
] | 2009-10-22 | [
[
"Arzt",
"C.",
""
]
] | Effective Lagrangians, including those that are spontaneously broken, contain redundant terms. It is shown that the classical equations of motion may be used to simplify the effective Lagrangian, even when quantum loops are to be considered. |
hep-ph/9705246 | Supratim Sengupta | Sanatan Digal, Supratim Sengupta and Ajit M. Srivastava (Institute Of
Physics, Bhubaneswar, India) | Vortex-Antivortex Pair Production in a First Order Phase Transition | 8 pages, Revtex, 14 figures. Figs.1a,b and 5a,d are included, rest
are availaible on request | Phys.Rev.D56:2035-2043,1997 | 10.1103/PhysRevD.56.2035 | IP-BBSR/97-19 | hep-ph cond-mat hep-th | null | We carry out numerical simulation of a first order phase transition in 2+1
dimensions by randomly nucleating bubbles, and study the formation of global
U(1) vortices. Bubbles grow and coalesce and vortices are formed at junctions
of bubbles via standard Kibble mechanism as well as due to a new mechanism,
recently proposed by us, where defect-antidefect pairs are produced due to
field oscillations. We make a comparative study of the contribution of both of
these mechanisms for vortex production. We find that, for high nucleation rate
of bubbles, vortex-antivortex pairs produced via the new mechanism have
overlapping configurations, and annihilate quickly; so only those vortices
survive till late which are produced via the Kibble mechanism. However, for low
nucleation rates, bubble collisions are energetic enough to lead to many well
separated vortex-antivortex pairs being produced via the new mechanism. For
example, in a simulation involving nucleation of 20 bubbles, a total of 14
non-overlapping vortices and antivortices formed via this new mechanism of pair
creation (6 of them being very well separated), as compared to 6 vortices and
antivortices produced via the Kibble mechanism. Our results show the
possibility that in extremely energetic bubble collisions, such as those in the
inflationary models of the early Universe, this new mechanism may drastically
affect the defect production scenario.
| [
{
"created": "Tue, 6 May 1997 14:03:15 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"Digal",
"Sanatan",
"",
"Institute Of\n Physics, Bhubaneswar, India"
],
[
"Sengupta",
"Supratim",
"",
"Institute Of\n Physics, Bhubaneswar, India"
],
[
"Srivastava",
"Ajit M.",
"",
"Institute Of\n Physics, Bhubaneswar, India"
]
] | We carry out numerical simulation of a first order phase transition in 2+1 dimensions by randomly nucleating bubbles, and study the formation of global U(1) vortices. Bubbles grow and coalesce and vortices are formed at junctions of bubbles via standard Kibble mechanism as well as due to a new mechanism, recently proposed by us, where defect-antidefect pairs are produced due to field oscillations. We make a comparative study of the contribution of both of these mechanisms for vortex production. We find that, for high nucleation rate of bubbles, vortex-antivortex pairs produced via the new mechanism have overlapping configurations, and annihilate quickly; so only those vortices survive till late which are produced via the Kibble mechanism. However, for low nucleation rates, bubble collisions are energetic enough to lead to many well separated vortex-antivortex pairs being produced via the new mechanism. For example, in a simulation involving nucleation of 20 bubbles, a total of 14 non-overlapping vortices and antivortices formed via this new mechanism of pair creation (6 of them being very well separated), as compared to 6 vortices and antivortices produced via the Kibble mechanism. Our results show the possibility that in extremely energetic bubble collisions, such as those in the inflationary models of the early Universe, this new mechanism may drastically affect the defect production scenario. |
2107.12402 | Xing Wang | Alexander Belyaev, R. Sekhar Chivukula, Benjamin Fuks, Elizabeth H.
Simmons, Xing Wang | Vector-Like top quark production via a chromo-magnetic moment at the LHC | 32 pages, 10 figures. matches published version | null | 10.1103/PhysRevD.104.095024 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Theories which provide a dynamical explanation for the large top-quark mass
often include TeV-scale vector-like top-quark and bottom-quark partner states
which can be potentially discovered at the LHC. These states are currently
probed through model-independent searches for pair-production via gluon fusion,
as well as through model-dependent complementary electroweak single production.
In this paper we study the potential to extend those searches for the partners
of the third-generation Standard Model quarks on the basis of their expected
chromomagnetic interactions. We discuss how current searches for "excited"
bottom-quarks produced via $b$-gluon fusion through chromomagnetic interactions
are relevant, and provide significant constraints. We then explore the region
of the parameter space in which the bottom-quark partner is heavier than the
top-quark partner, in which case the top-partner can be primarily produced via
the decay of the bottom-partner. Next, we probe the potential of the production
of a single top-quark partner in association with an ordinary top-quark by
gluon-fusion. Kinematically these two new processes are similar, and they yield
the production of a heavy top partner and a lighter Standard Model state, a
pattern which allows for the rejection of the associated dominant Standard
Model backgrounds. We examine the sensitivity of these modes in the case where
the top-partner subsequently decays to a Higgs boson and an ordinary top-quark,
and we demonstrate that these new channels have the potential of extending and
complementing the conventional strategies at LHC run III and at the
high-luminosity phase of the LHC. In this last case, we find that partner
masses that range up to about 3 TeV can be reached. This substantially expands
the expected mass reach for these new states, including regions of parameter
space that are inaccessible by traditional searches.
| [
{
"created": "Mon, 26 Jul 2021 18:00:19 GMT",
"version": "v1"
},
{
"created": "Tue, 8 Nov 2022 20:51:53 GMT",
"version": "v2"
}
] | 2022-11-10 | [
[
"Belyaev",
"Alexander",
""
],
[
"Chivukula",
"R. Sekhar",
""
],
[
"Fuks",
"Benjamin",
""
],
[
"Simmons",
"Elizabeth H.",
""
],
[
"Wang",
"Xing",
""
]
] | Theories which provide a dynamical explanation for the large top-quark mass often include TeV-scale vector-like top-quark and bottom-quark partner states which can be potentially discovered at the LHC. These states are currently probed through model-independent searches for pair-production via gluon fusion, as well as through model-dependent complementary electroweak single production. In this paper we study the potential to extend those searches for the partners of the third-generation Standard Model quarks on the basis of their expected chromomagnetic interactions. We discuss how current searches for "excited" bottom-quarks produced via $b$-gluon fusion through chromomagnetic interactions are relevant, and provide significant constraints. We then explore the region of the parameter space in which the bottom-quark partner is heavier than the top-quark partner, in which case the top-partner can be primarily produced via the decay of the bottom-partner. Next, we probe the potential of the production of a single top-quark partner in association with an ordinary top-quark by gluon-fusion. Kinematically these two new processes are similar, and they yield the production of a heavy top partner and a lighter Standard Model state, a pattern which allows for the rejection of the associated dominant Standard Model backgrounds. We examine the sensitivity of these modes in the case where the top-partner subsequently decays to a Higgs boson and an ordinary top-quark, and we demonstrate that these new channels have the potential of extending and complementing the conventional strategies at LHC run III and at the high-luminosity phase of the LHC. In this last case, we find that partner masses that range up to about 3 TeV can be reached. This substantially expands the expected mass reach for these new states, including regions of parameter space that are inaccessible by traditional searches. |
hep-ph/9509280 | Adriano Antonio Natale | A. A. Natale | Glueballs in Peripheral Heavy-Ion Collisions | 11 pages | Phys.Lett. B362 (1995) 177-181 | 10.1016/0370-2693(95)01146-H | IFT-P.039/95 | hep-ph | null | We estimate the cross-section for glueball production in peripheral heavy-ion
collisions through two-photon and double-Pomeron exchange, at energies that
will be available at RHIC and LHC. Glueballs will be produced at large rates,
opening the possibility to study decays with very small branching ratios. In
particular, we discuss the possibility of observing the subprocess $\gamma
\gamma (PP) \rightarrow G \rightarrow \gamma \gamma$.
| [
{
"created": "Tue, 12 Sep 1995 19:39:45 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Natale",
"A. A.",
""
]
] | We estimate the cross-section for glueball production in peripheral heavy-ion collisions through two-photon and double-Pomeron exchange, at energies that will be available at RHIC and LHC. Glueballs will be produced at large rates, opening the possibility to study decays with very small branching ratios. In particular, we discuss the possibility of observing the subprocess $\gamma \gamma (PP) \rightarrow G \rightarrow \gamma \gamma$. |
1107.3992 | Enrique Fernandez-Martinez | Mattias Blennow, Enrique Fernandez-Martinez | Parametrization of Seesaw Models and Light Sterile Neutrinos | 18 pages, REVTeX4. Minor corrections | null | 10.1016/j.physletb.2011.09.028 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The recent recomputation of the neutrino fluxes from nuclear reactors relaxes
the tension between the LSND and MiniBooNE anomalies and disappearance data
when interpreted in terms of sterile neutrino oscillations. The simplest
extension of the Standard Model with such fermion singlets is the addition of
right-handed sterile neutrinos with small Majorana masses. Even when
introducing three right-handed neutrinos, this scenario has less free
parameters than the 3+2 scenarios studied in the literature. This begs the
question whether the best fit regions obtained can be reproduced by this
simplest extension of the Standard Model. In order to address this question, we
devise an exact parametrization of Standard Model extensions with right-handed
neutrinos. Apart from the usual 3x3 neutrino mixing matrix and the 3 masses of
the lightest neutrinos, the extra degrees of freedom are encoded in another 3x3
unitary matrix and 3 additional mixing angles. The parametrization includes all
the correlations among masses and mixings and is valid beyond the usual seesaw
approximation. Through this parametrization we find that the best fit regions
for the LSND and MiniBooNE anomalies in a 3+2 scenario can indeed be reproduced
despite the smaller number of degrees of freedom.
| [
{
"created": "Wed, 20 Jul 2011 14:30:55 GMT",
"version": "v1"
},
{
"created": "Tue, 26 Jul 2011 12:11:00 GMT",
"version": "v2"
},
{
"created": "Tue, 11 Oct 2011 10:29:36 GMT",
"version": "v3"
}
] | 2015-05-28 | [
[
"Blennow",
"Mattias",
""
],
[
"Fernandez-Martinez",
"Enrique",
""
]
] | The recent recomputation of the neutrino fluxes from nuclear reactors relaxes the tension between the LSND and MiniBooNE anomalies and disappearance data when interpreted in terms of sterile neutrino oscillations. The simplest extension of the Standard Model with such fermion singlets is the addition of right-handed sterile neutrinos with small Majorana masses. Even when introducing three right-handed neutrinos, this scenario has less free parameters than the 3+2 scenarios studied in the literature. This begs the question whether the best fit regions obtained can be reproduced by this simplest extension of the Standard Model. In order to address this question, we devise an exact parametrization of Standard Model extensions with right-handed neutrinos. Apart from the usual 3x3 neutrino mixing matrix and the 3 masses of the lightest neutrinos, the extra degrees of freedom are encoded in another 3x3 unitary matrix and 3 additional mixing angles. The parametrization includes all the correlations among masses and mixings and is valid beyond the usual seesaw approximation. Through this parametrization we find that the best fit regions for the LSND and MiniBooNE anomalies in a 3+2 scenario can indeed be reproduced despite the smaller number of degrees of freedom. |
0808.1243 | Hovhannes Grigoryan | Hovhannes R. Grigoryan and Anatoly V. Radyushkin | Pion in the Holographic Model with 5D Yang-Mills Fields | 10 pages, 2 figures | Phys.Rev.D78:115008,2008 | 10.1103/PhysRevD.78.115008 | JLAB-THY-08-866 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study pion in the holographic model of Hirn and Sanz which contains two
Yang-Mills fields defined in the background of the sliced AdS space. The
infrared boundary conditions imposed on these fields generate the spontaneous
breaking of the chiral symmetry down to its vector subgroup. Within the
framework of this model, we get an analytic expression for the pion form factor
and a compact result for its radius. We also extend the holographic model to
include Chern-Simons term which is required to reproduce the appropriate axial
anomaly of QCD. As a result, we calculate the anomalous form factor of the pion
and predict its Q^2-slope for the kinematics when one of the photons is almost
on-shell. We also observe that the anomalous form factor with one real and one
virtual photon is given by the same analytic expression as the electromagnetic
form factor of a charged pion. One of the advantages of the present model is
that it does not require an infrared boundary counterterm to correctly
reproduce the anomaly of QCD.
| [
{
"created": "Fri, 8 Aug 2008 18:49:46 GMT",
"version": "v1"
}
] | 2008-12-15 | [
[
"Grigoryan",
"Hovhannes R.",
""
],
[
"Radyushkin",
"Anatoly V.",
""
]
] | We study pion in the holographic model of Hirn and Sanz which contains two Yang-Mills fields defined in the background of the sliced AdS space. The infrared boundary conditions imposed on these fields generate the spontaneous breaking of the chiral symmetry down to its vector subgroup. Within the framework of this model, we get an analytic expression for the pion form factor and a compact result for its radius. We also extend the holographic model to include Chern-Simons term which is required to reproduce the appropriate axial anomaly of QCD. As a result, we calculate the anomalous form factor of the pion and predict its Q^2-slope for the kinematics when one of the photons is almost on-shell. We also observe that the anomalous form factor with one real and one virtual photon is given by the same analytic expression as the electromagnetic form factor of a charged pion. One of the advantages of the present model is that it does not require an infrared boundary counterterm to correctly reproduce the anomaly of QCD. |
1706.00624 | Joshua Davies | Joshua Davies, Matthias Steinhauser, David Wellmann | Hadronic Higgs boson decay at order $\alpha_s^4$ and $\alpha_s^5$ | 6 pages, 0 figures. Contribution to the proceedings of the XXV
International Workshop on Deep-Inelastic Scattering and Related Topics
(DIS2017), 3-7 April 2017, University of Birmingham, UK. V2: Reference added | null | null | TTP17-028 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We compute corrections to the decay of the Standard Model Higgs boson to
hadrons, to the fourth order in the strong coupling constant $\alpha_s$. We use
an effective theory in which the Higgs boson couples directly to bottom quarks
and to gluons, via top quark--mediated effective couplings. Numerically, our
results are of a comparable size to the previously-known "massless"
contributions and complete the order $\alpha_s^4$ corrections to the hadronic
decay of the Higgs boson. In these proceedings we also provide an independent
cross check of the gluonic Higgs boson decay at order $\alpha_s^5$.
| [
{
"created": "Fri, 2 Jun 2017 10:53:38 GMT",
"version": "v1"
},
{
"created": "Fri, 16 Jun 2017 08:48:47 GMT",
"version": "v2"
}
] | 2017-06-19 | [
[
"Davies",
"Joshua",
""
],
[
"Steinhauser",
"Matthias",
""
],
[
"Wellmann",
"David",
""
]
] | We compute corrections to the decay of the Standard Model Higgs boson to hadrons, to the fourth order in the strong coupling constant $\alpha_s$. We use an effective theory in which the Higgs boson couples directly to bottom quarks and to gluons, via top quark--mediated effective couplings. Numerically, our results are of a comparable size to the previously-known "massless" contributions and complete the order $\alpha_s^4$ corrections to the hadronic decay of the Higgs boson. In these proceedings we also provide an independent cross check of the gluonic Higgs boson decay at order $\alpha_s^5$. |
1204.5683 | Alfredo Valcarce | T. F. Carames and A. Valcarce | Examination of the H dibaryon within a chiral constituent quark model | 14 pages, 13 figures | Physical Review C 85, 045202 (2012) | 10.1103/PhysRevC.85.045202 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We perform a coupled--channel calculation of the H dibaryon within a chiral
constituent quark model. The problem is solved within a quark model constrained
by the experimental data of strangeness --1 and --2 two--baryon systems. We
examine in detail the role played by the different contributions of the
interacting potential as well as the number of coupled channels considered.
Special attention has been payed to the parameter dependence, flavor symmetry
breaking and spatial configurations. The value extracted for the binding energy
of the H dibaryon, being compatible with the restrictions imposed by the Nagara
event, falls within a plausible extrapolation of recent lattice QCD results.
| [
{
"created": "Wed, 25 Apr 2012 15:39:13 GMT",
"version": "v1"
}
] | 2015-06-04 | [
[
"Carames",
"T. F.",
""
],
[
"Valcarce",
"A.",
""
]
] | We perform a coupled--channel calculation of the H dibaryon within a chiral constituent quark model. The problem is solved within a quark model constrained by the experimental data of strangeness --1 and --2 two--baryon systems. We examine in detail the role played by the different contributions of the interacting potential as well as the number of coupled channels considered. Special attention has been payed to the parameter dependence, flavor symmetry breaking and spatial configurations. The value extracted for the binding energy of the H dibaryon, being compatible with the restrictions imposed by the Nagara event, falls within a plausible extrapolation of recent lattice QCD results. |
hep-ph/0508226 | Eri Asakawa | E. Asakawa, O. Brein, S. Kanemura | Charged Higgs Production in Association with W Boson at Photon Colliders | To appear in the proceedings of 2005 International Linear Collider
Workshop (LCWS 2005), Stanford, California, 18-22 Mar 2005 | null | null | null | hep-ph | null | It is important to explore the Higgs sector in order to identify the model
beyond the standard model. We study the charged Higgs production in the
$\gamma\gamma$ mode of a linear collider (LC) with 1000 GeV center of mass
energy. We show that the cross sections for the $\gamma \gamma \to H^\pm W^\mp$
processes can be significantly enhanced in the two Higgs doublet model (THDM).
The cross section can reach 0.1 - 100 fb which is comparable to other charged
Higgs boson production processes at a photon collider. While for other
processes the cross sections are too small for $m_H^\pm \geq 500$ GeV, $0.1 -
100$ fb can be expected in the $\gamma\gamma \to H^\pm W^\mp$ processes for
$m_H^\pm \geq 570$ GeV when $m_{A^0}=800$ GeV. Therefore, even if the charged
Higgs bosons can not be detected at the Large Hadron Collider (LHC), and even
if the charged Higgs bosons are too heavy to be detected in other charged Higgs
boson production processes at the LC, it may be possible to detect them in this
process.
| [
{
"created": "Mon, 22 Aug 2005 05:58:38 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Asakawa",
"E.",
""
],
[
"Brein",
"O.",
""
],
[
"Kanemura",
"S.",
""
]
] | It is important to explore the Higgs sector in order to identify the model beyond the standard model. We study the charged Higgs production in the $\gamma\gamma$ mode of a linear collider (LC) with 1000 GeV center of mass energy. We show that the cross sections for the $\gamma \gamma \to H^\pm W^\mp$ processes can be significantly enhanced in the two Higgs doublet model (THDM). The cross section can reach 0.1 - 100 fb which is comparable to other charged Higgs boson production processes at a photon collider. While for other processes the cross sections are too small for $m_H^\pm \geq 500$ GeV, $0.1 - 100$ fb can be expected in the $\gamma\gamma \to H^\pm W^\mp$ processes for $m_H^\pm \geq 570$ GeV when $m_{A^0}=800$ GeV. Therefore, even if the charged Higgs bosons can not be detected at the Large Hadron Collider (LHC), and even if the charged Higgs bosons are too heavy to be detected in other charged Higgs boson production processes at the LC, it may be possible to detect them in this process. |
hep-ph/0108045 | Ivan Vitev | I. Vitev and M. Gyulassy | Anomalous Anti-proton to Negative Pion Ratio as Revealed by Jet
Quenching at RHIC | 5 pages, uses revtex and bbox.sty, INPC 2001 conference proceedings | null | 10.1063/1.1469986 | null | hep-ph | null | We study the apparent discrepancy between the standard PQCD predictions for
the meson and baryon ratios and multiplicities at moderate high $p_{T} > 2$ GeV
and recent experimental measurements in $Au+Au$ collisions at
$\sqrt{s}_{NN}=130$ GeV at the Relativistic Heavy Ion Collider (RHIC). We show
that the differences, most pronounced in central collisions, can be explained
by a strong non-perturbative baryon Junction component, which dominates the
currently accessible experimental $p_{T}$ window and the non-abelian energy
loss of fast partons propagating through hot and dense medium. The recently
introduced two component hybrid model, which combines a quenched jet PQCD
calculation in the Gyulassy-Levai-Vitev (GLV) formalism and a phenomenological
"soft" part, is further elaborated to take into account the full 3D expansion
in the pre-hadronization phase and include particle flavor dependent "soft"
inverse slopes as suggested by the baryon Junction picture. We show that such
approach can resolve what seems to be a factor of $\simeq 2$ difference in the
moderate high $p_{T}$ suppression of $\pi^0$ and $h^-$ as recently reported by
the PHENIX collaboration. The observed quenching of the high $p_{T}$ particle
spectra and the large $\bar{p}/\pi^-$ and $p/\pi^+$ ratios as a function of
$p_{T}$ are found to be consistent with a creation of a deconfined phase and
non-abelian energy loss of fast partons in a plasma of initial gluon rapidity
density $dN^g/dy \sim 1000$.
| [
{
"created": "Sat, 4 Aug 2001 16:52:29 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Vitev",
"I.",
""
],
[
"Gyulassy",
"M.",
""
]
] | We study the apparent discrepancy between the standard PQCD predictions for the meson and baryon ratios and multiplicities at moderate high $p_{T} > 2$ GeV and recent experimental measurements in $Au+Au$ collisions at $\sqrt{s}_{NN}=130$ GeV at the Relativistic Heavy Ion Collider (RHIC). We show that the differences, most pronounced in central collisions, can be explained by a strong non-perturbative baryon Junction component, which dominates the currently accessible experimental $p_{T}$ window and the non-abelian energy loss of fast partons propagating through hot and dense medium. The recently introduced two component hybrid model, which combines a quenched jet PQCD calculation in the Gyulassy-Levai-Vitev (GLV) formalism and a phenomenological "soft" part, is further elaborated to take into account the full 3D expansion in the pre-hadronization phase and include particle flavor dependent "soft" inverse slopes as suggested by the baryon Junction picture. We show that such approach can resolve what seems to be a factor of $\simeq 2$ difference in the moderate high $p_{T}$ suppression of $\pi^0$ and $h^-$ as recently reported by the PHENIX collaboration. The observed quenching of the high $p_{T}$ particle spectra and the large $\bar{p}/\pi^-$ and $p/\pi^+$ ratios as a function of $p_{T}$ are found to be consistent with a creation of a deconfined phase and non-abelian energy loss of fast partons in a plasma of initial gluon rapidity density $dN^g/dy \sim 1000$. |
hep-ph/0106022 | Silas R. Beane | S.R. Beane | Constraining Quark-Hadron Duality at Large-Nc | 16 pages TeX, uses mtexsis.tex | Phys.Rev. D64 (2001) 116010 | 10.1103/PhysRevD.64.116010 | NT@UW-01-012 | hep-ph hep-th nucl-th | null | Quark-meson duality for two-point functions of vector and axial-vector QCD
currents is investigated in the large-Nc approximation. We find that the joint
constraints of duality and chiral symmetry imply degeneracy of excited vector
and axial-vector mesons in the large-Nc limit. We compare model-independent
constraints with expectations based on the Veneziano-Lovelace-Shapiro string
model. Several models of duality are constructed, and phenomenological
implications are discussed.
| [
{
"created": "Fri, 1 Jun 2001 22:33:21 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Beane",
"S. R.",
""
]
] | Quark-meson duality for two-point functions of vector and axial-vector QCD currents is investigated in the large-Nc approximation. We find that the joint constraints of duality and chiral symmetry imply degeneracy of excited vector and axial-vector mesons in the large-Nc limit. We compare model-independent constraints with expectations based on the Veneziano-Lovelace-Shapiro string model. Several models of duality are constructed, and phenomenological implications are discussed. |
0802.3427 | Andrej Arbuzov | A.B. Arbuzov, B.M. Barbashov, A. Borowiec, V.N. Pervushin, S.A.
Shuvalov, A.F. Zakharov | Is it possible to estimate the Higgs Mass from the CMB Power Spectrum? | version to appear in Yadernaya Fizika | null | 10.1134/S1063778809050019 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | General Relativity and Standard Model are considered as a theory of dynamical
scale symmetry with definite initial data compatible with the accepted Higgs
mechanism. In this theory the Early Universe behaves like a factory of
electroweak bosons and Higgs scalars, and it gives a possibility to identify
three peaks in the Cosmic Microwave Background power spectrum with the
contributions of photonic decays and annihilation processes of primordial
Higgs, W, and Z bosons in agreement with the QED coupling constant, Weinberg's
angle, and Higgs' particle mass of about 118 GeV.
| [
{
"created": "Mon, 25 Feb 2008 14:27:34 GMT",
"version": "v1"
},
{
"created": "Mon, 31 Mar 2008 15:14:24 GMT",
"version": "v2"
},
{
"created": "Thu, 10 Jul 2008 04:53:09 GMT",
"version": "v3"
},
{
"created": "Wed, 3 Sep 2008 06:36:42 GMT",
"version": "v4"
},
{
"created": "Tue, 30 Sep 2008 07:20:43 GMT",
"version": "v5"
},
{
"created": "Wed, 15 Apr 2009 13:35:13 GMT",
"version": "v6"
}
] | 2009-04-15 | [
[
"Arbuzov",
"A. B.",
""
],
[
"Barbashov",
"B. M.",
""
],
[
"Borowiec",
"A.",
""
],
[
"Pervushin",
"V. N.",
""
],
[
"Shuvalov",
"S. A.",
""
],
[
"Zakharov",
"A. F.",
""
]
] | General Relativity and Standard Model are considered as a theory of dynamical scale symmetry with definite initial data compatible with the accepted Higgs mechanism. In this theory the Early Universe behaves like a factory of electroweak bosons and Higgs scalars, and it gives a possibility to identify three peaks in the Cosmic Microwave Background power spectrum with the contributions of photonic decays and annihilation processes of primordial Higgs, W, and Z bosons in agreement with the QED coupling constant, Weinberg's angle, and Higgs' particle mass of about 118 GeV. |
1404.2702 | Oleg Selyugin | O.V. Selyugin | Models of parton distributions and the description of form factors of
nucleon | 14 pages; 15 figures; (corrected some misprints in text and
references) | Phys. Rev. D 89, 093007, (2014) | 10.1103/PhysRevD.89.093007 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The comparative analysis of different sets of the parton distribution
functions (PDFs), based on the description of the whole sets of experimental
data of electromagnetic form factors of the proton and neutron, is made in the
framework of the model of t-dependence of the generalized parton distributions
(GPDs) with minimum free parameters and some extending variants of the model.
In some cases, a large difference in the description of electromagnetic form
factors of nucleons with using the different sets of PDF are found out. The
different variants of the flavor dependence of the up and down quark form
factors are presented and discussed. The gravitation form factors, obtained
with the different sets of PDF, are also calculated and the anomalous
gravimagnetic moment is compared with the Equivalence Principle. The
calculations of the differential cross sections of the real Compton scattering
are presented.
| [
{
"created": "Thu, 10 Apr 2014 06:06:31 GMT",
"version": "v1"
},
{
"created": "Fri, 23 May 2014 07:45:07 GMT",
"version": "v2"
}
] | 2015-06-19 | [
[
"Selyugin",
"O. V.",
""
]
] | The comparative analysis of different sets of the parton distribution functions (PDFs), based on the description of the whole sets of experimental data of electromagnetic form factors of the proton and neutron, is made in the framework of the model of t-dependence of the generalized parton distributions (GPDs) with minimum free parameters and some extending variants of the model. In some cases, a large difference in the description of electromagnetic form factors of nucleons with using the different sets of PDF are found out. The different variants of the flavor dependence of the up and down quark form factors are presented and discussed. The gravitation form factors, obtained with the different sets of PDF, are also calculated and the anomalous gravimagnetic moment is compared with the Equivalence Principle. The calculations of the differential cross sections of the real Compton scattering are presented. |
hep-ph/9910215 | null | D. Falcone, F. Tramontano | Testing quark mass matrices with right-handed mixings | 12 pages RevTex, no figures. Minor corrections. Comment on SO(10)
changed and one reference added | Phys.Rev. D61 (2000) 113013 | 10.1103/PhysRevD.61.113013 | DSF-T-99/33 | hep-ph | null | In the standard model, several forms of quark mass matrices which correspond
to the choice of weak bases lead to the same left-handed mixings $V_L=V_{CKM}$,
while the right-handed mixings $V_R$ are not observable quantities. Instead, in
a left-right extension of the standard model, such forms are ansatze and give
different right-handed mixings which are now observable quantities. We
partially select the reliable forms of quark mass matrices by means of
constraints on right-handed mixings in some left-right models, in particular on
$V^R_{cb}$. Hermitian matrices are easily excluded.
| [
{
"created": "Mon, 4 Oct 1999 08:08:25 GMT",
"version": "v1"
},
{
"created": "Mon, 13 Dec 1999 13:24:30 GMT",
"version": "v2"
},
{
"created": "Fri, 14 Jan 2000 13:45:39 GMT",
"version": "v3"
}
] | 2009-10-31 | [
[
"Falcone",
"D.",
""
],
[
"Tramontano",
"F.",
""
]
] | In the standard model, several forms of quark mass matrices which correspond to the choice of weak bases lead to the same left-handed mixings $V_L=V_{CKM}$, while the right-handed mixings $V_R$ are not observable quantities. Instead, in a left-right extension of the standard model, such forms are ansatze and give different right-handed mixings which are now observable quantities. We partially select the reliable forms of quark mass matrices by means of constraints on right-handed mixings in some left-right models, in particular on $V^R_{cb}$. Hermitian matrices are easily excluded. |
hep-ph/0110188 | Biswajoy Brahmachari | Biswajoy Brahmachari | Adjoint bulk scalars and supersymmetric unification in the presence of
extra dimensions | New references added. This version will appear in Phys. Rev. D | Phys.Rev. D65 (2002) 067502 | 10.1103/PhysRevD.65.067502 | SINP/TNP/01-21 | hep-ph hep-th | null | There are several advantages of introducing adjoint superfields at
intermediate energies around $M=10^{13}$ GeV. Such as (i) gauge couplings still
unify (ii) neutrino masses and mixings are produced (iii) primordial lepton
asymmetry can be produced. We point out that if adjoint scalars have bulk
excitations along with gauge bosons whereas fermions and the doublet scalar
live on boundary then N=2 supersymmetric beta functions $\tilde{b_i}$ vanish.
Thus even if extra dimensions open up at an intermediate scale $\mu_0$ and all
N=2 Yang-Mills fields as well as N=2 matter fields in the adjoint
representation propagate in the bulk, still gauge couplings renormalize beyond
$\mu_0$ just like they do in 4-dimensions with adjoint scalars. Consequently
unification is achieved in the presence to extra dimensions, mass scales are
determined uniquely via Renormalization Group Equations(RGE) and unification
scale remains high enough to suppress proton decay. This scenario can be
falsified if we get signatures of extra dimensions at low energy.
| [
{
"created": "Mon, 15 Oct 2001 13:46:47 GMT",
"version": "v1"
},
{
"created": "Tue, 1 Jan 2002 05:09:36 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Brahmachari",
"Biswajoy",
""
]
] | There are several advantages of introducing adjoint superfields at intermediate energies around $M=10^{13}$ GeV. Such as (i) gauge couplings still unify (ii) neutrino masses and mixings are produced (iii) primordial lepton asymmetry can be produced. We point out that if adjoint scalars have bulk excitations along with gauge bosons whereas fermions and the doublet scalar live on boundary then N=2 supersymmetric beta functions $\tilde{b_i}$ vanish. Thus even if extra dimensions open up at an intermediate scale $\mu_0$ and all N=2 Yang-Mills fields as well as N=2 matter fields in the adjoint representation propagate in the bulk, still gauge couplings renormalize beyond $\mu_0$ just like they do in 4-dimensions with adjoint scalars. Consequently unification is achieved in the presence to extra dimensions, mass scales are determined uniquely via Renormalization Group Equations(RGE) and unification scale remains high enough to suppress proton decay. This scenario can be falsified if we get signatures of extra dimensions at low energy. |
1811.02199 | Qi-An Zhang | Qi-An Zhang | Weak Decays of Doubly Heavy Baryons: W-Exchange | 9 pages, 1 figure | null | 10.1140/epjc/s10052-018-6481-x | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Since the LHCb collaboration announced the observation of the doubly charmed
baryon $\Xi_{cc}^{++}$, a series of studies of doubly heavy baryons have been
presented. In this work, I analyse the non-leptonic weak decays of doubly heavy
baryons $\Xi_{bc}$ and $\Omega_{bc}$ under the flavor $SU(3)$ symmetry. I
mainly focus on the $W$-exchange diagrams, which will contribute to the decay
channels with final states are light meson and light baryon. These channels
would be helpful for searching for $\Xi_{bc}$ and $\Omega_{bc}$ at LHC. And
these channels and relations of corresponding decay widths could be examined by
the future experimental facilities such as LHC, Belle II and CEPC.
| [
{
"created": "Tue, 6 Nov 2018 07:16:37 GMT",
"version": "v1"
}
] | 2019-01-30 | [
[
"Zhang",
"Qi-An",
""
]
] | Since the LHCb collaboration announced the observation of the doubly charmed baryon $\Xi_{cc}^{++}$, a series of studies of doubly heavy baryons have been presented. In this work, I analyse the non-leptonic weak decays of doubly heavy baryons $\Xi_{bc}$ and $\Omega_{bc}$ under the flavor $SU(3)$ symmetry. I mainly focus on the $W$-exchange diagrams, which will contribute to the decay channels with final states are light meson and light baryon. These channels would be helpful for searching for $\Xi_{bc}$ and $\Omega_{bc}$ at LHC. And these channels and relations of corresponding decay widths could be examined by the future experimental facilities such as LHC, Belle II and CEPC. |
1803.04662 | Masafumi Kurachi | Minoru Eto, Masafumi Kurachi, Muneto Nitta | Constraints on two Higgs doublet models from domain walls | 11 pages, 5 figures. v2: Discussion on the constraint on the mass of
the CP-odd Higgs boson, that contained an error in v1, was removed. The title
of the paper has been changed accordingly. Other parts, that are unaffected
by the error, were refined as well. v3 matches published version in Phys.
Lett. B | Phys.Lett. B785 (2018) 447-453 | 10.1016/j.physletb.2018.09.002 | YGHP-18-05, KEK-TH-2041 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We show that there is a constraint on the parameter space of two Higgs
doublet models that comes from the existence of the stable vortex-domain wall
systems. The constraint is quite universal in the sense that it depends on only
two combinations of Lagrangian parameters and does not depend on how fermions
couple to two Higgs fields. Numerical solutions of field configurations of
domain wall-vortex system are obtained, which provide a basis for further
quantitative study of cosmology which involve such topological objects.
| [
{
"created": "Tue, 13 Mar 2018 07:25:56 GMT",
"version": "v1"
},
{
"created": "Fri, 6 Jul 2018 13:04:09 GMT",
"version": "v2"
},
{
"created": "Thu, 13 Sep 2018 14:18:53 GMT",
"version": "v3"
}
] | 2018-09-14 | [
[
"Eto",
"Minoru",
""
],
[
"Kurachi",
"Masafumi",
""
],
[
"Nitta",
"Muneto",
""
]
] | We show that there is a constraint on the parameter space of two Higgs doublet models that comes from the existence of the stable vortex-domain wall systems. The constraint is quite universal in the sense that it depends on only two combinations of Lagrangian parameters and does not depend on how fermions couple to two Higgs fields. Numerical solutions of field configurations of domain wall-vortex system are obtained, which provide a basis for further quantitative study of cosmology which involve such topological objects. |
1611.01623 | Peter Kroll | Peter Kroll | The exclusive Drell-Yan process and deeply virtual pion production | 8 pages, 6 figures, latex with style files jpsj-suppl.cls and
cite.sty invited talk presented at MENU2016, Kyoto (Japan), July 2016. arXiv
admin note: substantial text overlap with arXiv:1602.03803 | null | 10.7566/JPSCP.13.010014 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this talk it is reported on analyses of l p -> l pi+ n and pi- p -> l+ l-
n within the handbag approach. It is argued that recent measurements of hard
pion production performed by HERMES and CLAS clearly indicate the occurrence of
strong contributions from transversely polarized photons. The gamma*T -> pi
transitions are described by the transversity GPDs accompanied by twist-3 pion
wave functions. The experiments also require strong contributions from the pion
pole which can be modeled as a classical one-pion exchange. With these
extensions the handbag approach leads to results on cross sections and spin
asymmetries in fair agreement with experiment. This approach is also used for
an estimate of the partial cross sections for the exclusive Drell-Yan process.
| [
{
"created": "Sat, 5 Nov 2016 09:50:57 GMT",
"version": "v1"
}
] | 2017-03-08 | [
[
"Kroll",
"Peter",
""
]
] | In this talk it is reported on analyses of l p -> l pi+ n and pi- p -> l+ l- n within the handbag approach. It is argued that recent measurements of hard pion production performed by HERMES and CLAS clearly indicate the occurrence of strong contributions from transversely polarized photons. The gamma*T -> pi transitions are described by the transversity GPDs accompanied by twist-3 pion wave functions. The experiments also require strong contributions from the pion pole which can be modeled as a classical one-pion exchange. With these extensions the handbag approach leads to results on cross sections and spin asymmetries in fair agreement with experiment. This approach is also used for an estimate of the partial cross sections for the exclusive Drell-Yan process. |
hep-ph/0612015 | Gilad Perez | Kaustubh Agashe, Alexander Belyaev, Tadas Krupovnickas, Gilad Perez &
Joseph Virzi | LHC Signals from Warped Extra Dimensions | 11 pages and 6 figures | Phys.Rev.D77:015003,2008 | 10.1103/PhysRevD.77.015003 | BNL-HET-06/13, MSUHEP-060915, SU-4252-838, YITP-SB-06-43 | hep-ph hep-ex | null | We study production of Kaluza-Klein gluons (KKG) at the Large Hadron Collider
(LHC) in the framework of a warped extra dimension with the Standard Model (SM)
fields propagating in the bulk. We show that the detection of KK gluon is
challenging since its production is suppressed by small couplings to the
proton's constituents. Moreover, the KK gluon decays mostly to top pairs due to
an enhanced coupling and hence is broad. Nevertheless, we demonstrate that for
m_{KKG} \lesssim 4 TeV, 100 fb^{-1} of data at the LHC can provide discovery of
the KK gluon. We utilize a sizeable left-right polarization asymmetry from the
KK gluon resonance to maximize the signal significance, and we explore the
novel feature of extremely highly energetic "top-jets". We briefly discuss how
the detection of electroweak gauge KK states (Z/W) faces a similar challenge
since their leptonic decays (``golden'' modes) are suppressed. Our analysis
suggests that other frameworks, for example little Higgs, which rely on UV
completion via strong dynamics might face similar challenges, namely (1)
Suppressed production rates for the new particles (such as Z'), due to their
``light-fermion-phobic'' nature, and (2) Difficulties in detection since the
new particles are broad and decay predominantly to third generation quarks and
longitudinal gauge bosons.
| [
{
"created": "Mon, 4 Dec 2006 13:24:20 GMT",
"version": "v1"
}
] | 2010-04-06 | [
[
"Agashe",
"Kaustubh",
""
],
[
"Belyaev",
"Alexander",
""
],
[
"Krupovnickas",
"Tadas",
""
],
[
"Perez",
"Gilad",
""
],
[
"Virzi",
"Joseph",
""
]
] | We study production of Kaluza-Klein gluons (KKG) at the Large Hadron Collider (LHC) in the framework of a warped extra dimension with the Standard Model (SM) fields propagating in the bulk. We show that the detection of KK gluon is challenging since its production is suppressed by small couplings to the proton's constituents. Moreover, the KK gluon decays mostly to top pairs due to an enhanced coupling and hence is broad. Nevertheless, we demonstrate that for m_{KKG} \lesssim 4 TeV, 100 fb^{-1} of data at the LHC can provide discovery of the KK gluon. We utilize a sizeable left-right polarization asymmetry from the KK gluon resonance to maximize the signal significance, and we explore the novel feature of extremely highly energetic "top-jets". We briefly discuss how the detection of electroweak gauge KK states (Z/W) faces a similar challenge since their leptonic decays (``golden'' modes) are suppressed. Our analysis suggests that other frameworks, for example little Higgs, which rely on UV completion via strong dynamics might face similar challenges, namely (1) Suppressed production rates for the new particles (such as Z'), due to their ``light-fermion-phobic'' nature, and (2) Difficulties in detection since the new particles are broad and decay predominantly to third generation quarks and longitudinal gauge bosons. |
hep-ph/0312098 | Biswajoy Brahmachari | Biswajoy Brahmachari | Single and double seesaw for quark-lepton and neutrino masses | Latex. Invited talk in ICFP-2003, Seoul, Korea, Oct 6-11, 2003. To
appear in proceedings | J.Korean Phys.Soc. 45 (2004) S230-S231 | null | VEC/PHYSICS/P/1/2003-2004 | hep-ph | null | A left-right model of quarks and leptons based on the gauge group $SU(3)_c
\times SU(2)_L \times SU(2)_R \times U(1)_{B-L}$ is studied. Here the scalar
sector consists of only two doublets namely (1,2,1,1) and (1,1,2,1) but
familiar bidoublet (1,2,2,0) is removed. Quarks and charged leptons get mass
from a single see-saw mechanism but neutrinos get mass from a double see-saw
mechanism. In this type of models the heaviest right handed neutrino can be of
order $10^{13}$ GeVs or less in a natural way, depending on the size of related
Yukawa couplings.
| [
{
"created": "Sun, 7 Dec 2003 11:31:48 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Brahmachari",
"Biswajoy",
""
]
] | A left-right model of quarks and leptons based on the gauge group $SU(3)_c \times SU(2)_L \times SU(2)_R \times U(1)_{B-L}$ is studied. Here the scalar sector consists of only two doublets namely (1,2,1,1) and (1,1,2,1) but familiar bidoublet (1,2,2,0) is removed. Quarks and charged leptons get mass from a single see-saw mechanism but neutrinos get mass from a double see-saw mechanism. In this type of models the heaviest right handed neutrino can be of order $10^{13}$ GeVs or less in a natural way, depending on the size of related Yukawa couplings. |
hep-ph/9905510 | Salavat Abdullin | Salavat Abdullin (IReS, Strasbourg, France) and Daniel Denegri
(Saclay, France) | On b- and tau-multiplicities per event in SUSY (mSUGRA) and instrumental
implications | 19 pages, 13 figures, 3 tables | null | null | CMS NOTE 1999/035 | hep-ph | null | We investigate the probability to find a b or tau in SUSY production with the
mSUGRA model. We find that in the entire parameter space the probability per
event to find a b-jet of E_T^b > 50 GeV within CMS acceptance (eta < 2.4) is
significant for all tan(beta), varying from a 10 % level to 90 % depending on
the m_0, m_1/2 region. The probabilities per event to find a tau with the same
kinematical cuts is also significant and it increases sharply with tan(beta).
These findings point to the central role a microvertex device would play in
case that SUSY (mSUGRA) is indeed realized in nature and found at the LHC.
First investigations done in the context of the more general MSSM scenario
confirm the findings based on mSUGRA.
| [
{
"created": "Thu, 27 May 1999 14:27:30 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Abdullin",
"Salavat",
"",
"IReS, Strasbourg, France"
],
[
"Denegri",
"Daniel",
"",
"Saclay, France"
]
] | We investigate the probability to find a b or tau in SUSY production with the mSUGRA model. We find that in the entire parameter space the probability per event to find a b-jet of E_T^b > 50 GeV within CMS acceptance (eta < 2.4) is significant for all tan(beta), varying from a 10 % level to 90 % depending on the m_0, m_1/2 region. The probabilities per event to find a tau with the same kinematical cuts is also significant and it increases sharply with tan(beta). These findings point to the central role a microvertex device would play in case that SUSY (mSUGRA) is indeed realized in nature and found at the LHC. First investigations done in the context of the more general MSSM scenario confirm the findings based on mSUGRA. |
hep-ph/0411220 | Leonard Gamberg | Leonard P. Gamberg, Gary R. Goldstein, and Karo A. Oganessyan | Novel Azimuthal Asymmetries in Drell Yan and Semi-inclusive Deep
Inelastic Scattering | 6 pages, 4 figures | null | 10.1063/1.1871656 | null | hep-ph | null | We consider the leading and sub-leading twist $T$-odd and even contributions
to the $\cos 2\phi$ azimuthal asymmetry in unpolarized dilepton production in
Drell-Yan Scattering. We estimate the contributions' effects at $500 {\rm
GeV}$, $ 50 {\rm GeV}$, and $25 {\rm GeV}$ energies in the framework of the
parton model using a quark diquark-spectator model of the nucleon to
approximate the soft contributions.
| [
{
"created": "Tue, 16 Nov 2004 22:56:37 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Gamberg",
"Leonard P.",
""
],
[
"Goldstein",
"Gary R.",
""
],
[
"Oganessyan",
"Karo A.",
""
]
] | We consider the leading and sub-leading twist $T$-odd and even contributions to the $\cos 2\phi$ azimuthal asymmetry in unpolarized dilepton production in Drell-Yan Scattering. We estimate the contributions' effects at $500 {\rm GeV}$, $ 50 {\rm GeV}$, and $25 {\rm GeV}$ energies in the framework of the parton model using a quark diquark-spectator model of the nucleon to approximate the soft contributions. |
1702.07702 | Sofia Leit\~ao | Sofia Leit\~ao, Alfred Stadler, M. T. Pe\~na and E. P. Biernat | Application of the Covariant Spectator Theory to the study of heavy and
heavy-light mesons | null | null | 10.1007/s00601-017-1251-0 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | As an application of the Covariant Spectator Theory (CST) we calculate the
spectrum of heavy-light and heavy-heavy mesons using covariant versions of a
linear confining potential, a one- gluon exchange, and a constant interaction.
The CST equations possess the correct one-body limit and are therefore
well-suited to describe mesons in which one quark is much heavier than the
other. We find a good fit to the mass spectrum of heavy-light and heavy-heavy
mesons with just three parameters (apart from the quark masses). Remarkably,
the fit parameters are nearly unchanged when we fit to experimental
pseudoscalar states only or to the whole spectrum. Because pseudoscalar states
are insensitive to spin-orbit interactions and do not determine spin-spin
interactions separately from central interactions, this result suggests that it
is the covariance of the kernel that correctly predicts the spin-dependent
quark-antiquark interactions
| [
{
"created": "Fri, 24 Feb 2017 18:46:27 GMT",
"version": "v1"
}
] | 2017-03-01 | [
[
"Leitão",
"Sofia",
""
],
[
"Stadler",
"Alfred",
""
],
[
"Peña",
"M. T.",
""
],
[
"Biernat",
"E. P.",
""
]
] | As an application of the Covariant Spectator Theory (CST) we calculate the spectrum of heavy-light and heavy-heavy mesons using covariant versions of a linear confining potential, a one- gluon exchange, and a constant interaction. The CST equations possess the correct one-body limit and are therefore well-suited to describe mesons in which one quark is much heavier than the other. We find a good fit to the mass spectrum of heavy-light and heavy-heavy mesons with just three parameters (apart from the quark masses). Remarkably, the fit parameters are nearly unchanged when we fit to experimental pseudoscalar states only or to the whole spectrum. Because pseudoscalar states are insensitive to spin-orbit interactions and do not determine spin-spin interactions separately from central interactions, this result suggests that it is the covariance of the kernel that correctly predicts the spin-dependent quark-antiquark interactions |
2108.07338 | Jaydeb Das | Diganta Das, Jaydeb Das | Sterile neutrinos in $\Lambda_b^0\to
(\Lambda_c^+,p^+)\ell^-_1\ell^-_2\ell^+_3\nu$ decays | null | null | 10.1103/PhysRevD.105.013009 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We study lepton number violating and lepton number conserving semi-leptonic
decays of heavy baryons $\Lambda_b^0$ to three charged leptons and a neutrino.
The decays occur through two intermediate quasi-degenerate GeV-scale sterile
neutrinos of either Majorana or Dirac type that can be on-shell. Interference
between the intermediate heavy neutrinos leads to CP violation in the final
states. Effect of neutrino oscillations between the heavy states are also
considered in observables of interests, \emph{i.e.,} branching ratio, and the
CP-asymmetry. Given the present constraints on the heavy-to-light mixing
elements $|V_{eN}|$ and $|V_{\mu N}|$, CP-averaged branching ratio of
$\Lambda_b^0\to (\Lambda_c,p)\mu\mu e\nu$ with intermediate Majorana neutrinos
is almost two orders of magnitude larger than for the same with Dirac
neutrinos, whereas, CP-averaged branching ratio of $\Lambda_b^0\to
(\Lambda_c,p)ee\mu\nu$ is of the same order of magnitude for both Majorana and
Dirac neutrino induced decays. CP-violation is found to be appreciable when the
neutrino mass difference is comparable with the average decay widths.
| [
{
"created": "Mon, 16 Aug 2021 20:36:04 GMT",
"version": "v1"
},
{
"created": "Thu, 2 Sep 2021 11:03:17 GMT",
"version": "v2"
}
] | 2022-01-26 | [
[
"Das",
"Diganta",
""
],
[
"Das",
"Jaydeb",
""
]
] | We study lepton number violating and lepton number conserving semi-leptonic decays of heavy baryons $\Lambda_b^0$ to three charged leptons and a neutrino. The decays occur through two intermediate quasi-degenerate GeV-scale sterile neutrinos of either Majorana or Dirac type that can be on-shell. Interference between the intermediate heavy neutrinos leads to CP violation in the final states. Effect of neutrino oscillations between the heavy states are also considered in observables of interests, \emph{i.e.,} branching ratio, and the CP-asymmetry. Given the present constraints on the heavy-to-light mixing elements $|V_{eN}|$ and $|V_{\mu N}|$, CP-averaged branching ratio of $\Lambda_b^0\to (\Lambda_c,p)\mu\mu e\nu$ with intermediate Majorana neutrinos is almost two orders of magnitude larger than for the same with Dirac neutrinos, whereas, CP-averaged branching ratio of $\Lambda_b^0\to (\Lambda_c,p)ee\mu\nu$ is of the same order of magnitude for both Majorana and Dirac neutrino induced decays. CP-violation is found to be appreciable when the neutrino mass difference is comparable with the average decay widths. |
hep-ph/9312243 | Craig Roberts | Reinhard Alkofer, Axel Bender and Craig D. Roberts | Pion Loop Contribution to the Electromagnetic Pion Charge Radius | 22 Pages, 5 figures uuencoded and appended to this file, REVTEX 3.0.
ANL-PHY-7663-TH-93, UNITUE-THEP-13/1993 | Int.J.Mod.Phys.A10:3319-3342,1995 | 10.1142/S0217751X95001601 | null | hep-ph nucl-th | null | A phenomenological Dyson-Schwinger equation approach to QCD, formalised in
terms of a QCD based model field theory, is used to calculate the
electromagnetic charge radius of the pion. The contributions from the quark
core and pion loop, as defined in this approach, are identified and compared.
It is shown explicitly that the divergence of the charge radius in the chiral
limit is due to the pion loop and that, at the physical value of the pion mass,
this loop contributes less than 15\% to $\langle r^2_\pi\rangle$; i.e. the
quark core is the dominant determining characteristic for the pion. This
suggests that quark based models which fail to reproduce the $\ln\,m_\pi$
divergence of $\langle r^2_\pi\rangle$ may nevertheless incorporate the
dominant characteristic of the pion: its quark core.
| [
{
"created": "Tue, 7 Dec 1993 22:47:10 GMT",
"version": "v1"
}
] | 2010-03-04 | [
[
"Alkofer",
"Reinhard",
""
],
[
"Bender",
"Axel",
""
],
[
"Roberts",
"Craig D.",
""
]
] | A phenomenological Dyson-Schwinger equation approach to QCD, formalised in terms of a QCD based model field theory, is used to calculate the electromagnetic charge radius of the pion. The contributions from the quark core and pion loop, as defined in this approach, are identified and compared. It is shown explicitly that the divergence of the charge radius in the chiral limit is due to the pion loop and that, at the physical value of the pion mass, this loop contributes less than 15\% to $\langle r^2_\pi\rangle$; i.e. the quark core is the dominant determining characteristic for the pion. This suggests that quark based models which fail to reproduce the $\ln\,m_\pi$ divergence of $\langle r^2_\pi\rangle$ may nevertheless incorporate the dominant characteristic of the pion: its quark core. |
1008.2254 | Jacek Pawelczyk | Jacek Pawelczyk | F-theory inspired GUTs with extra charged matter | 13 pages, Latex, minor changes and clarifications, corrections to the
description of Table 1 | Phys.Lett.B697:75-79,2011 | 10.1016/j.physletb.2011.01.031 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider GUT models inspired by recent local F-theory constructions. We
show that after switching on vevs to scalars the extra matter becomes
messengers. We discuss conditions on these vevs under which the models do not
lead to unacceptable baryon/lepton number violating processes.
| [
{
"created": "Fri, 13 Aug 2010 06:25:21 GMT",
"version": "v1"
},
{
"created": "Wed, 27 Oct 2010 12:59:46 GMT",
"version": "v2"
},
{
"created": "Fri, 4 Feb 2011 14:13:07 GMT",
"version": "v3"
}
] | 2011-02-07 | [
[
"Pawelczyk",
"Jacek",
""
]
] | We consider GUT models inspired by recent local F-theory constructions. We show that after switching on vevs to scalars the extra matter becomes messengers. We discuss conditions on these vevs under which the models do not lead to unacceptable baryon/lepton number violating processes. |
hep-ph/0303099 | Adam K. Leibovich | Adam K. Leibovich, Zoltan Ligeti, and Mark B. Wise | Comment on Quark Masses in SCET | 7 pages | Phys.Lett.B564:231-234,2003 | 10.1016/S0370-2693(03)00565-3 | FERMILAB-Pub-03/035-T, LBNL-52196, CALT-68-2432 | hep-ph | null | Quark masses are included in the SCET Lagrangian. Treating the strange quark
mass as order Lambda_{QCD}, we find that strange quark mass terms are
suppressed in SCET1, but are leading order in SCET2. This is relevant for B
decays to K^* and K. Strange quark mass effects in semileptonic and weak
radiative form factors are studied. They give corrections to the form factors
that are not suppressed by powers of the bottom quark mass, or, equivalently,
by the large recoil energy of the final state meson, and and preserve the heavy
to light form factor relations that follow from using the leading order
current.
| [
{
"created": "Wed, 12 Mar 2003 19:58:13 GMT",
"version": "v1"
},
{
"created": "Fri, 21 Mar 2003 21:47:54 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"Leibovich",
"Adam K.",
""
],
[
"Ligeti",
"Zoltan",
""
],
[
"Wise",
"Mark B.",
""
]
] | Quark masses are included in the SCET Lagrangian. Treating the strange quark mass as order Lambda_{QCD}, we find that strange quark mass terms are suppressed in SCET1, but are leading order in SCET2. This is relevant for B decays to K^* and K. Strange quark mass effects in semileptonic and weak radiative form factors are studied. They give corrections to the form factors that are not suppressed by powers of the bottom quark mass, or, equivalently, by the large recoil energy of the final state meson, and and preserve the heavy to light form factor relations that follow from using the leading order current. |
0807.0202 | Jernej Kamenik | Jan O. Eeg, Svjetlana Fajfer and Jernej F. Kamenik | Chiral corrections to the scalar form factor in B_q to D_q transitions | 5 pages, 3 figures | Phys.Rev.D78:074008,2008 | 10.1103/PhysRevD.78.074008 | null | hep-ph hep-lat | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider chiral loop corrections to the scalar form factor in B_q to D_q l
nu decays. First we consider chiral corrections to the 1/m_Q suppressed
operators and then we propose the procedure for the extraction of the relevant
form factor using lattice QCD results. In the case of B_s to D_s l nu decay we
find that effects of kinematics and chiral corrections tend to cancel for the
scalar form factor contributions. In particular the 1/m_Q suppression of chiral
corrections is compensated by the SU(3) flavor symmetry breaking corrections
which can be as large as 30%. The calculated corrections are relevant for the
precise determination of possible new physics effects in B_q to D_q l nu
decays.
| [
{
"created": "Tue, 1 Jul 2008 17:07:20 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Eeg",
"Jan O.",
""
],
[
"Fajfer",
"Svjetlana",
""
],
[
"Kamenik",
"Jernej F.",
""
]
] | We consider chiral loop corrections to the scalar form factor in B_q to D_q l nu decays. First we consider chiral corrections to the 1/m_Q suppressed operators and then we propose the procedure for the extraction of the relevant form factor using lattice QCD results. In the case of B_s to D_s l nu decay we find that effects of kinematics and chiral corrections tend to cancel for the scalar form factor contributions. In particular the 1/m_Q suppression of chiral corrections is compensated by the SU(3) flavor symmetry breaking corrections which can be as large as 30%. The calculated corrections are relevant for the precise determination of possible new physics effects in B_q to D_q l nu decays. |
hep-ph/0204293 | Koichi Yoshioka | Masahiro Yamaguchi and Koichi Yoshioka | Dynamical Solution to Supersymmetric CP Problem with Vanishing B
Parameter | 13 pages, a comment added | Phys.Lett. B543 (2002) 189-196 | 10.1016/S0370-2693(02)02454-1 | TU-652T | hep-ph | null | The CP violation gives rise to severe restriction of soft breaking terms in
supersymmetric standard models. Among them, constraints on the holomorphic soft
mass of Higgs doublets (the B parameter) are difficult to satisfy due to the
other inherent problem in the Higgs potential; the mu problem. In this letter,
it is argued that these CP and mu problems can be rather relaxed provided that
B is vanishing at high-energy scale. A generic mechanism and some examples of
model are presented to dynamically realize this condition by introducing gauge
singlet fields.
| [
{
"created": "Thu, 25 Apr 2002 09:02:54 GMT",
"version": "v1"
},
{
"created": "Tue, 6 Aug 2002 07:18:39 GMT",
"version": "v2"
}
] | 2010-04-05 | [
[
"Yamaguchi",
"Masahiro",
""
],
[
"Yoshioka",
"Koichi",
""
]
] | The CP violation gives rise to severe restriction of soft breaking terms in supersymmetric standard models. Among them, constraints on the holomorphic soft mass of Higgs doublets (the B parameter) are difficult to satisfy due to the other inherent problem in the Higgs potential; the mu problem. In this letter, it is argued that these CP and mu problems can be rather relaxed provided that B is vanishing at high-energy scale. A generic mechanism and some examples of model are presented to dynamically realize this condition by introducing gauge singlet fields. |
hep-ph/0410247 | Teruaki Suyama | Teruaki Suyama, Takahiro Tanaka, Bruce Bassett, Hideaki Kudoh | Are black holes over-produced during preheating? | 12 pages, 8 figures, revtex, added references for section 1 | Phys.Rev. D71 (2005) 063507 | 10.1103/PhysRevD.71.063507 | KUNS-1939, UTAP-498 | hep-ph astro-ph gr-qc | null | We provide a simple but robust argument that primordial black hole (PBH)
production generically does {\em not} exceed astrophysical bounds during the
resonant preheating phase after inflation. This conclusion is supported by
fully nonlinear lattice simulations of various models in two and three
dimensions which include rescattering but neglect metric perturbations. We
examine the degree to which preheating amplifies density perturbations at the
Hubble scale and show that at the end of the parametric resonance, power
spectra are universal, with no memory of the power spectrum at the end of
inflation. In addition we show how the probability distribution of density
perturbations changes from exponential on very small scales to Gaussian when
smoothed over the Hubble scale -- the crucial length for studies of primordial
black hole formation -- hence justifying the standard assumption of
Gaussianity.
| [
{
"created": "Mon, 18 Oct 2004 12:08:55 GMT",
"version": "v1"
},
{
"created": "Thu, 28 Oct 2004 01:30:24 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Suyama",
"Teruaki",
""
],
[
"Tanaka",
"Takahiro",
""
],
[
"Bassett",
"Bruce",
""
],
[
"Kudoh",
"Hideaki",
""
]
] | We provide a simple but robust argument that primordial black hole (PBH) production generically does {\em not} exceed astrophysical bounds during the resonant preheating phase after inflation. This conclusion is supported by fully nonlinear lattice simulations of various models in two and three dimensions which include rescattering but neglect metric perturbations. We examine the degree to which preheating amplifies density perturbations at the Hubble scale and show that at the end of the parametric resonance, power spectra are universal, with no memory of the power spectrum at the end of inflation. In addition we show how the probability distribution of density perturbations changes from exponential on very small scales to Gaussian when smoothed over the Hubble scale -- the crucial length for studies of primordial black hole formation -- hence justifying the standard assumption of Gaussianity. |
hep-ph/9904252 | Hsin-Chia Cheng | Hsin-Chia Cheng (Fermilab) | Doublet-Triplet Splitting and Fermion Masses with Extra Dimensions | 16 pages, 4 figures, LaTeX, references and some clarifying remarks
added, to be published in Phys. Rev. D | Phys. Rev. D 60, 075015 (1999) | 10.1103/PhysRevD.60.075015 | Fermilab-PUB-99/094-T | hep-ph | null | The pseudo-Goldstone boson mechanism for the ``doublet-triplet splitting''
problem of the grand unified theory can be naturally implemented in the
scenario with extra dimensions and branes. The two SU(6) global symmetries of
the Higgs sector are located on two separate branes while the SU(6) gauge
symmetry is in the bulk. After including several vector-like fields in the
bulk, and allowing the most general interactions with their natural strength
(including the higher dimensional ones which may be generated by gravity) which
are consistent with the geometry, a realistic pattern of the Standard Model
fermion masses and mixings can be naturally obtained without any flavor
symmetry. Neutrino masses and mixings required for the solar and atmospheric
neutrino problems can also be accommodated. The geometry of extra dimensions
and branes provides another way to realize the absence of certain interactions
(as required in the pseudo-Goldstone boson mechanism) or the smallness of some
couplings (e.g., the Yukawa couplings between the fermions and the Higgs
bosons), in addition to the usual symmetry arguments.
| [
{
"created": "Tue, 6 Apr 1999 22:22:19 GMT",
"version": "v1"
},
{
"created": "Mon, 19 Jul 1999 21:17:42 GMT",
"version": "v2"
}
] | 2016-08-25 | [
[
"Cheng",
"Hsin-Chia",
"",
"Fermilab"
]
] | The pseudo-Goldstone boson mechanism for the ``doublet-triplet splitting'' problem of the grand unified theory can be naturally implemented in the scenario with extra dimensions and branes. The two SU(6) global symmetries of the Higgs sector are located on two separate branes while the SU(6) gauge symmetry is in the bulk. After including several vector-like fields in the bulk, and allowing the most general interactions with their natural strength (including the higher dimensional ones which may be generated by gravity) which are consistent with the geometry, a realistic pattern of the Standard Model fermion masses and mixings can be naturally obtained without any flavor symmetry. Neutrino masses and mixings required for the solar and atmospheric neutrino problems can also be accommodated. The geometry of extra dimensions and branes provides another way to realize the absence of certain interactions (as required in the pseudo-Goldstone boson mechanism) or the smallness of some couplings (e.g., the Yukawa couplings between the fermions and the Higgs bosons), in addition to the usual symmetry arguments. |
1201.0511 | Ambresh Shivaji | Pankaj Agrawal, Ambresh Shivaji | Multi Vector Boson Production via Gluon Fusion at the LHC | 8 pages, 4 figures. Prepared for 10th International Symposium on
Radiative Corrections (Applications of Quantum Field Theory to
Phenomenology), September 26-30, 2011, Mamallapuram, India. a factor of 4
corrected in the cross-section calculation | PoS RADCOR2011 (2011) 010 | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | At the LHC, the processes with several particles in the final state occur
routinely. These processes provide a new domain to test the Standard Model of
particle physics. Due to large gluon luminosity at the LHC, gluon initiated
processes will be quite important. We study the production of multi-vector
bosons via gluon fusion. In particular we consider the process $ g g \to g
\gamma Z $ and compute its cross-section at hadron colliders.
| [
{
"created": "Mon, 2 Jan 2012 18:42:02 GMT",
"version": "v1"
},
{
"created": "Sun, 22 Apr 2012 13:46:09 GMT",
"version": "v2"
}
] | 2013-05-13 | [
[
"Agrawal",
"Pankaj",
""
],
[
"Shivaji",
"Ambresh",
""
]
] | At the LHC, the processes with several particles in the final state occur routinely. These processes provide a new domain to test the Standard Model of particle physics. Due to large gluon luminosity at the LHC, gluon initiated processes will be quite important. We study the production of multi-vector bosons via gluon fusion. In particular we consider the process $ g g \to g \gamma Z $ and compute its cross-section at hadron colliders. |
1906.02119 | Thomas Hahn | T. Hahn | New Features in FeynArts & Friends, and how they got used in FeynHiggs | 6 pages, contribution to ACAT 2019, Saas Fee, Switzerland, March
11-15, 2019 | null | 10.1088/1742-6596/1525/1/012008 | MPP-2019-112 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This note gives an update on recent developments in FeynArts, FormCalc, and
LoopTools, and shows how the new features were used in making the latest
version of FeynHiggs.
| [
{
"created": "Wed, 5 Jun 2019 16:45:35 GMT",
"version": "v1"
}
] | 2020-08-26 | [
[
"Hahn",
"T.",
""
]
] | This note gives an update on recent developments in FeynArts, FormCalc, and LoopTools, and shows how the new features were used in making the latest version of FeynHiggs. |
1012.1806 | Marco Zaro | Marco Zaro, Paolo Bolzoni, Fabio Maltoni, Sven-Olaf Moch | Charged Higgs production via vector-boson fusion at NNLO in QCD | 6 pages, proceedings of the "cHarged 2010" conference, Uppsala, Sept.
2010 | PoS Charged2010:028,2010 | null | CP3-10-39 DESY 10-235 | hep-ph | http://creativecommons.org/licenses/by-nc-sa/3.0/ | We present the total cross sections at next-to-next-to-leading order (NNLO)
in the strong coupling for single and double charged Higgs production via weak
boson fusion. Results are obtained via the structure function approach, which
builds upon the approximate, though very accurate, factorization of the QCD
corrections between the two quark lines. The theoretical uncertainty on the
total cross sections at the LHC from higher order corrections and the parton
distribution uncertainties are estimated at the 2% level each for a wide range
of Higgs boson masses.
| [
{
"created": "Wed, 8 Dec 2010 17:01:17 GMT",
"version": "v1"
}
] | 2011-10-06 | [
[
"Zaro",
"Marco",
""
],
[
"Bolzoni",
"Paolo",
""
],
[
"Maltoni",
"Fabio",
""
],
[
"Moch",
"Sven-Olaf",
""
]
] | We present the total cross sections at next-to-next-to-leading order (NNLO) in the strong coupling for single and double charged Higgs production via weak boson fusion. Results are obtained via the structure function approach, which builds upon the approximate, though very accurate, factorization of the QCD corrections between the two quark lines. The theoretical uncertainty on the total cross sections at the LHC from higher order corrections and the parton distribution uncertainties are estimated at the 2% level each for a wide range of Higgs boson masses. |
hep-ph/9506455 | Per Osland | B. Kileng, P. Osland, P.N. Pandita | Production and Two-photon Decay of the MSSM Scalar Higgs Bosons at the
LHC | 16 pages, LaTex, plus 9 uuencoded figures attached Full ps file
available at ftp://vsfys1.fi.uib.no/anonymous/pub/ as nordita-9548.ps or
nordita-9548.ps-gz or via http://vsfys1.fi.uib.no/thpubl/publications.html | Z.Phys. C71 (1996) 87-94 | 10.1007/s002880050150 | NORDITA 95/48 P | hep-ph | null | We consider the production and two-photon decay of the $CP$-even Higgs bosons
($h^0$ and $H^0$) of the Minimal Supersymmetric Standard Model (MSSM) at the
Large Hadron Collider. We study in detail the dependence of the cross section
on various parameters of the MSSM, especially the dependence on the mixing
effects in the squark sector due to the Higgs bilinear parameter $\mu$ and the
soft supersymmetry breaking parameter $A$. We find that the cross section for
the production of these Higgs bosons has a significant dependence on the
parameters which determine the chiral mixing in the squark sector. The cross
section times the two-photon branching ratio of $h^0$ is of the order of
15--25~fb in much of the parameter space that remains after imposing the
present experimental constraints. For the $H^0$ the two-photon branching ratio
is only significant if the $H^0$ is light, but then the cross section times the
branching ratio may exceed 200~fb. The QCD corrections due to quark loop
contributions are known to increase the cross section by 50\%. We find the
dependence of the cross section on the gluon distribution function used to be
rather insignificant.
| [
{
"created": "Thu, 29 Jun 1995 16:27:49 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Kileng",
"B.",
""
],
[
"Osland",
"P.",
""
],
[
"Pandita",
"P. N.",
""
]
] | We consider the production and two-photon decay of the $CP$-even Higgs bosons ($h^0$ and $H^0$) of the Minimal Supersymmetric Standard Model (MSSM) at the Large Hadron Collider. We study in detail the dependence of the cross section on various parameters of the MSSM, especially the dependence on the mixing effects in the squark sector due to the Higgs bilinear parameter $\mu$ and the soft supersymmetry breaking parameter $A$. We find that the cross section for the production of these Higgs bosons has a significant dependence on the parameters which determine the chiral mixing in the squark sector. The cross section times the two-photon branching ratio of $h^0$ is of the order of 15--25~fb in much of the parameter space that remains after imposing the present experimental constraints. For the $H^0$ the two-photon branching ratio is only significant if the $H^0$ is light, but then the cross section times the branching ratio may exceed 200~fb. The QCD corrections due to quark loop contributions are known to increase the cross section by 50\%. We find the dependence of the cross section on the gluon distribution function used to be rather insignificant. |
2112.03883 | Daniel Schuh | Andreas Ipp, David I. M\"uller, Daniel Schuh | On transverse momentum broadening in real-time lattice simulations of
the glasma and in the weak-field limit | 8 pages, 3 figures, submitted to vConf2021 conference proceedings | null | 10.1051/epjconf/202225805002 | null | hep-ph hep-lat nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In these proceedings, we report on our numerical lattice simulations of
partons traversing the boost-invariant, non-perturbative glasma as created at
the early stages of collisions at RHIC and LHC. Since these highly energetic
partons are produced from hard scatterings during heavy-ion collisions, they
are already affected by the first stage of the medium's time evolution, the
glasma, which is the pre-equilibrium precursor state of the quark-gluon plasma.
We find that partons quickly accumulate transverse momentum up to the
saturation momentum during the glasma stage. Moreover, we observe an
interesting anisotropy in transverse momentum broadening of partons with larger
broadening in the rapidity than in the azimuthal direction. Its origin can be
related to correlations among the longitudinal color-electric and
color-magnetic flux tubes in the initial state of the glasma. We compare these
observations to the semi-analytic results obtained by a weak-field
approximation, where we also find such an anisotropy in a parton's transverse
momentum broadening.
| [
{
"created": "Tue, 7 Dec 2021 18:27:36 GMT",
"version": "v1"
}
] | 2022-02-16 | [
[
"Ipp",
"Andreas",
""
],
[
"Müller",
"David I.",
""
],
[
"Schuh",
"Daniel",
""
]
] | In these proceedings, we report on our numerical lattice simulations of partons traversing the boost-invariant, non-perturbative glasma as created at the early stages of collisions at RHIC and LHC. Since these highly energetic partons are produced from hard scatterings during heavy-ion collisions, they are already affected by the first stage of the medium's time evolution, the glasma, which is the pre-equilibrium precursor state of the quark-gluon plasma. We find that partons quickly accumulate transverse momentum up to the saturation momentum during the glasma stage. Moreover, we observe an interesting anisotropy in transverse momentum broadening of partons with larger broadening in the rapidity than in the azimuthal direction. Its origin can be related to correlations among the longitudinal color-electric and color-magnetic flux tubes in the initial state of the glasma. We compare these observations to the semi-analytic results obtained by a weak-field approximation, where we also find such an anisotropy in a parton's transverse momentum broadening. |
2110.11910 | Mosleh Almarashi | M. M. Almarashi | Review of a light NMSSM pseudoscalar Higgs state production at the LHC | 10 figures, 3 tables | Universe 2021, 7, 392 | 10.3390/universe7110392 | null | hep-ph | http://creativecommons.org/licenses/by-nc-sa/4.0/ | In this paper we briefly review the LHC discovery potential of a light
pseudoscalar Higgs boson of the NMSSM, $a_1$, produced in the gluon fusion
$gg\to a_1$ , bottom-quark fusion $b\bar b\to a_1$ and bottom-gluon fusion
$bg\to ba_1$. We also review the LHC discovery potential of the
next-to-lightest CP-even Higgs boson $h_2$ being the non-SM-like Higgs,
decaying either into two light CP-odd Higgs bosons $a_1 a_1$ or into a light
$a_1$ and the $Z$ gauge boson through the gluon fusion $gg \to h_2$ in the
4$\tau$ final state. We find that the light $a_1$ can be detected at the LHC in
a variety of production processes including the gluon fusion, bottom-quark
fusion and bottom-gluon fusion. The latter two processes require high
luminosity of the LHC and large values of tan$\beta$. We also find that the LHC
has the potential to discover the non-SM-like Higgs state, $h_2$, decaying into
a pair of light CP-odd Higgses $a_1$'s, allowing to distinguish the NMSSM Higgs
sector from the MSSM one as such a light $a_1$ is impossible in the latter
scenario.
| [
{
"created": "Fri, 22 Oct 2021 16:54:29 GMT",
"version": "v1"
}
] | 2021-10-25 | [
[
"Almarashi",
"M. M.",
""
]
] | In this paper we briefly review the LHC discovery potential of a light pseudoscalar Higgs boson of the NMSSM, $a_1$, produced in the gluon fusion $gg\to a_1$ , bottom-quark fusion $b\bar b\to a_1$ and bottom-gluon fusion $bg\to ba_1$. We also review the LHC discovery potential of the next-to-lightest CP-even Higgs boson $h_2$ being the non-SM-like Higgs, decaying either into two light CP-odd Higgs bosons $a_1 a_1$ or into a light $a_1$ and the $Z$ gauge boson through the gluon fusion $gg \to h_2$ in the 4$\tau$ final state. We find that the light $a_1$ can be detected at the LHC in a variety of production processes including the gluon fusion, bottom-quark fusion and bottom-gluon fusion. The latter two processes require high luminosity of the LHC and large values of tan$\beta$. We also find that the LHC has the potential to discover the non-SM-like Higgs state, $h_2$, decaying into a pair of light CP-odd Higgses $a_1$'s, allowing to distinguish the NMSSM Higgs sector from the MSSM one as such a light $a_1$ is impossible in the latter scenario. |
2009.02936 | Adam Takacs | Adam Takacs and Daniel Pablos and Konrad Tywoniuk | Resolving the spacetime structure of jets with medium | 5 pages, 4 figures, 10th International Conference on Hard and
Electromagnetic Probes of High-Energy Nuclear Collisions (Hard Probes 2020) | PoS 387 (HardProbes2020) 161 | 10.22323/1.387.0161 | null | hep-ph hep-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Away from the strictly soft and collinear limit of QCD radiation the choice
of evolution scale in a parton shower algorithm is ambiguous and several
options have been implemented in existing Monte Carlo event generators for
proton-proton collisions. However, the resulting space-time evolution could
result in subtle differences depending on the particular choice. In this work
we quantify measurable consequences of the choice of the evolution variable and
show how the implications of such a choice propagates into jet quenching
observables. We develop a parton shower algorithm for a general evolution
variable, that includes as special cases the virtuality, angle, transverse
momentum and formation time. We study the interplay between the shower history
for different evolution variables and the phase space affected by parton energy
loss. In particular, we implement effects of jet quenching in the dense limit
and highlight the role of color coherence effects. We compare the results of
the different ordering variables to existing Monte Carlo shower implementations
on the parton level by analyzing primary Lund planes. Finally, we study the
sensitivity of quenched jets to the choice of evolution variable by confronting
our results for a certain key observable, such as the jet mass.
| [
{
"created": "Mon, 7 Sep 2020 08:20:46 GMT",
"version": "v1"
}
] | 2022-09-23 | [
[
"Takacs",
"Adam",
""
],
[
"Pablos",
"Daniel",
""
],
[
"Tywoniuk",
"Konrad",
""
]
] | Away from the strictly soft and collinear limit of QCD radiation the choice of evolution scale in a parton shower algorithm is ambiguous and several options have been implemented in existing Monte Carlo event generators for proton-proton collisions. However, the resulting space-time evolution could result in subtle differences depending on the particular choice. In this work we quantify measurable consequences of the choice of the evolution variable and show how the implications of such a choice propagates into jet quenching observables. We develop a parton shower algorithm for a general evolution variable, that includes as special cases the virtuality, angle, transverse momentum and formation time. We study the interplay between the shower history for different evolution variables and the phase space affected by parton energy loss. In particular, we implement effects of jet quenching in the dense limit and highlight the role of color coherence effects. We compare the results of the different ordering variables to existing Monte Carlo shower implementations on the parton level by analyzing primary Lund planes. Finally, we study the sensitivity of quenched jets to the choice of evolution variable by confronting our results for a certain key observable, such as the jet mass. |
hep-ph/9801336 | Yuan Feng | Kuang-Ta Chao, Cong-Feng Qiao, and Feng Yuan (Peking University) | Gluon fragmentation to $^3D_J$ quarkonium and test of color-octet
production mechanism | 6 pages, lprocl.sty included, in proceedings of the VII Blois Work
Shop, Seoul, Korea, June 1997 | null | null | PKU-TP-97-39 | hep-ph | null | We report the recent progress in the studies of D-wave heavy quarkonia
production from gluon fragmentation at the Tevatron and in Z^0 decays, and the
D-wave charmonia production in B decays. We show that the color-octet
contributions are of crucial importance to the production of D-wave quarkonia.
Signals, as strong as that for J/\psi and \psi^\prime, should be seen for the
D-wave charmonium in the processes. These will provide a test of the
color-octet production mechanism.
| [
{
"created": "Mon, 19 Jan 1998 03:21:24 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Chao",
"Kuang-Ta",
"",
"Peking University"
],
[
"Qiao",
"Cong-Feng",
"",
"Peking University"
],
[
"Yuan",
"Feng",
"",
"Peking University"
]
] | We report the recent progress in the studies of D-wave heavy quarkonia production from gluon fragmentation at the Tevatron and in Z^0 decays, and the D-wave charmonia production in B decays. We show that the color-octet contributions are of crucial importance to the production of D-wave quarkonia. Signals, as strong as that for J/\psi and \psi^\prime, should be seen for the D-wave charmonium in the processes. These will provide a test of the color-octet production mechanism. |
1104.3855 | Alessandro Bacchetta | Alessandro Bacchetta (U. Pavia and INFN Pavia), A. Courtoy (INFN
Pavia), Marco Radici (INFN Pavia) | First glances at the transversity parton distribution through dihadron
fragmentation functions | Minor changes in text and references | Phys.Rev.Lett.107:012001,2011 | 10.1103/PhysRevLett.107.012001 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present first observations of the transversity parton distribution based
on an analysis of pion-pair production in deep inelastic scattering off
transversely polarized targets. The extraction of transversity relies on the
knowledge of dihadron fragmentation functions, which we take from
electron-positron annihilation measurements. This is the first attempt to
determine the transversity distribution in the framework of collinear
factorization.
| [
{
"created": "Tue, 19 Apr 2011 19:58:25 GMT",
"version": "v1"
},
{
"created": "Wed, 26 Oct 2011 12:57:34 GMT",
"version": "v2"
}
] | 2011-10-27 | [
[
"Bacchetta",
"Alessandro",
"",
"U. Pavia and INFN Pavia"
],
[
"Courtoy",
"A.",
"",
"INFN\n Pavia"
],
[
"Radici",
"Marco",
"",
"INFN Pavia"
]
] | We present first observations of the transversity parton distribution based on an analysis of pion-pair production in deep inelastic scattering off transversely polarized targets. The extraction of transversity relies on the knowledge of dihadron fragmentation functions, which we take from electron-positron annihilation measurements. This is the first attempt to determine the transversity distribution in the framework of collinear factorization. |
1702.08904 | Gil Paz | Ayesh Gunawardana and Gil Paz | On HQET and NRQCD Operators of Dimension 8 and Above | 28 pages, footnote added, journal version | JHEP 1707 (2017) 137 | 10.1007/JHEP07(2017)137 | WSU-HEP-1701 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Effective field theories such as Heavy Quark Effective Theory (HQET) and Non
Relativistic Quantum Chromo-(Electro-) dynamics NRQCD (NRQED) are indispensable
tools in controlling the effects of the strong interaction. The increasing
experimental precision requires the knowledge of higher dimensional operators.
We present a general method that allows for an easy construction of HQET or
NRQCD (NRQED) operators that contain two heavy quark or non-relativistic fields
and any number of covariant derivatives. As an application of our method, we
list these terms in the $1/M^4$ NRQCD Lagrangian, where $M$ is the mass of of
the spin-half field.
| [
{
"created": "Tue, 28 Feb 2017 18:48:36 GMT",
"version": "v1"
},
{
"created": "Thu, 8 Jun 2017 17:58:10 GMT",
"version": "v2"
},
{
"created": "Wed, 23 Aug 2017 19:42:12 GMT",
"version": "v3"
}
] | 2017-08-25 | [
[
"Gunawardana",
"Ayesh",
""
],
[
"Paz",
"Gil",
""
]
] | Effective field theories such as Heavy Quark Effective Theory (HQET) and Non Relativistic Quantum Chromo-(Electro-) dynamics NRQCD (NRQED) are indispensable tools in controlling the effects of the strong interaction. The increasing experimental precision requires the knowledge of higher dimensional operators. We present a general method that allows for an easy construction of HQET or NRQCD (NRQED) operators that contain two heavy quark or non-relativistic fields and any number of covariant derivatives. As an application of our method, we list these terms in the $1/M^4$ NRQCD Lagrangian, where $M$ is the mass of of the spin-half field. |
hep-ph/0305055 | Igor O. Cherednikov | Igor O. Cherednikov | Nonperturbative contributions to the quark form factor at high energy | REVTeX, 12 pages, 1 figure. Important references and discussions
added, misprints corrected, minor changes in text | Surveys High Energ.Phys. 18 (2003) 205-220 | 10.1080/01422410310001610392 | null | hep-ph hep-ex hep-th nucl-th | null | The analysis of nonperturbative effects in high energy asymptotics of the
electomagnetic quark form factor is presented. It is shown that the
nonperturbative effects determine the initial value for the perturbative
evolution of the quark form factor and find their general structure with
respect to the high energy asymptotics. Within the Wilson integral formalism
which is natural for investigation of the soft, IR sensitive, part of the
factorized form factor, the structure of the instanton induced effects in the
evolution equation is discussed. It is demonstrated that the instanton
contributions result in the finite renormalization of the subleading
perturbative result and numerically are characterized by small factor
reflecting the diluteness of the QCD vacuum within the instanton liquid model.
The relevance of the IR renormalon induced effects in high energy asymptotic
behaviour is discussed. The consequences of the various analytization
procedures of the strong coupling constant in the IR domain are considered.
| [
{
"created": "Tue, 6 May 2003 11:11:44 GMT",
"version": "v1"
},
{
"created": "Tue, 23 Sep 2003 14:53:15 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Cherednikov",
"Igor O.",
""
]
] | The analysis of nonperturbative effects in high energy asymptotics of the electomagnetic quark form factor is presented. It is shown that the nonperturbative effects determine the initial value for the perturbative evolution of the quark form factor and find their general structure with respect to the high energy asymptotics. Within the Wilson integral formalism which is natural for investigation of the soft, IR sensitive, part of the factorized form factor, the structure of the instanton induced effects in the evolution equation is discussed. It is demonstrated that the instanton contributions result in the finite renormalization of the subleading perturbative result and numerically are characterized by small factor reflecting the diluteness of the QCD vacuum within the instanton liquid model. The relevance of the IR renormalon induced effects in high energy asymptotic behaviour is discussed. The consequences of the various analytization procedures of the strong coupling constant in the IR domain are considered. |
hep-ph/0009116 | Teiji Kunihiro | Teiji Kunihiro | Roles of Chiral Symmetry and the Sigma Meson in Hadron and Nuclear
Physics | Typos are corrected. Some of statements are moved to footnotes | null | null | null | hep-ph hep-ex nucl-ex nucl-th | null | We first review the recent accumulating evidences of the existence of a
scalar-isoscalar meson with the mass 500 to 800 MeV which may be identified
with the sigma meson as the quantum fluctuation of the amplitude of the chiral
order parameter. We indicate that phase shift analyses which respect chiral
symmetry (ChS), analyticity and crossing symmetry of the scattering amplitude
show the sigma meson pole in the $s$-channel as well as the $\rho$ meson pole
in the $t$-channel in the pi-pi scattering in the $I=J=0$ channel. We emphasize
that the existence of the $\sigma$ resonance does not contradict with the
success of the chiral perturbation theory; phenomenological difficulties with
the renormalizable linear sigma model do not necessarily deny the validity of
the linear representation of ChS of QCD as given by the NJL-like models which
not only admit the $\sigma$ resonance but also reproduce the coupling constants
$L_i$ and $H_i$ appearing the nonlinear chiral lagrangian. We give some
examples of the hadronic phenomena which are naturally accounted for with the
$\sigma$ meson. We show that the the $\sigma$ meson as the amplitude
fluctuation of the chiral order parameter may be more clearly identified than
in free space in hot and/or dense matter, even in finite nuclei where partial
restoration of ChS may be realized.
| [
{
"created": "Mon, 11 Sep 2000 08:49:31 GMT",
"version": "v1"
},
{
"created": "Sat, 21 Oct 2000 09:06:16 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Kunihiro",
"Teiji",
""
]
] | We first review the recent accumulating evidences of the existence of a scalar-isoscalar meson with the mass 500 to 800 MeV which may be identified with the sigma meson as the quantum fluctuation of the amplitude of the chiral order parameter. We indicate that phase shift analyses which respect chiral symmetry (ChS), analyticity and crossing symmetry of the scattering amplitude show the sigma meson pole in the $s$-channel as well as the $\rho$ meson pole in the $t$-channel in the pi-pi scattering in the $I=J=0$ channel. We emphasize that the existence of the $\sigma$ resonance does not contradict with the success of the chiral perturbation theory; phenomenological difficulties with the renormalizable linear sigma model do not necessarily deny the validity of the linear representation of ChS of QCD as given by the NJL-like models which not only admit the $\sigma$ resonance but also reproduce the coupling constants $L_i$ and $H_i$ appearing the nonlinear chiral lagrangian. We give some examples of the hadronic phenomena which are naturally accounted for with the $\sigma$ meson. We show that the the $\sigma$ meson as the amplitude fluctuation of the chiral order parameter may be more clearly identified than in free space in hot and/or dense matter, even in finite nuclei where partial restoration of ChS may be realized. |
hep-ph/9602296 | null | N. Armesto, M. A. Braun, E. G. Ferreiro, C. Pajares and Yu. M.
Shabelski | Fusion of strings and cosmic rays at ultrahigh energies | LaTeX, 11 pages plus 3 figures in a separate postcript file | Phys.Lett. B389 (1996) 78-82 | 10.1016/S0370-2693(96)01248-8 | US--FT/6--96 | hep-ph | null | It is shown that the fusion of strings is a source of particle production in
nucleus--nucleus collisions outside the kinematical limits of nucleon--nucleon
collisions. This fact, together with another effect of string fusion, the
reduction of multiplicities, sheds some light on two of the main problems of
ultrahigh energy cosmic rays, the chemical composition and the energy of the
most energetic detected cosmic rays.
| [
{
"created": "Tue, 13 Feb 1996 10:24:55 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Armesto",
"N.",
""
],
[
"Braun",
"M. A.",
""
],
[
"Ferreiro",
"E. G.",
""
],
[
"Pajares",
"C.",
""
],
[
"Shabelski",
"Yu. M.",
""
]
] | It is shown that the fusion of strings is a source of particle production in nucleus--nucleus collisions outside the kinematical limits of nucleon--nucleon collisions. This fact, together with another effect of string fusion, the reduction of multiplicities, sheds some light on two of the main problems of ultrahigh energy cosmic rays, the chemical composition and the energy of the most energetic detected cosmic rays. |
1809.10184 | Graham D. Kribs | Graham D. Kribs, Adam Martin, Bryan Ostdiek, and Tom Tong | Dark Mesons at the LHC | 45 pages, 12 figures; typos fixed, refs updated, GitHub page:
https://github.com/bostdiek/HeavyDarkMesons | null | 10.1007/JHEP07(2019)133 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A new, strongly-coupled dark sector could be accessible to LHC searches now.
These dark sectors consist of composites formed from constituents that are
charged under the electroweak group and interact with the Higgs, but are
neutral under Standard Model color. In these scenarios, the most promising
target is the dark meson sector, consisting of dark vector-mesons as well as
dark pions. In this paper we study dark meson production and decay at the LHC
in theories that preserve a global SU(2) dark flavor symmetry. Dark pions can
be pair-produced through resonant dark vector meson production, $p
p\to\rho_D\to\pi_D\pi_D$, and decay in one of two distinct ways: gaugephobic,
when $\pi_D\to f\bar{f}'$ generally dominates; or gaugephilic, when $\pi_D\to
W+h,Z+h$ dominates once kinematically open. Unlike QCD, the decay
$\pi^0_D\to\gamma\gamma$ is virtually absent due to the dark flavor symmetry.
We recast a vast set of LHC searches to determine the current constraints on
dark meson production and decay. When $m_{\rho_D}$ is slightly heavier than $2
m_{\pi_D}$ and $\rho_D^{\pm,0}$ kinetically mixes with the weak gauge bosons,
the 8 TeV same-sign lepton search strategy sets the best bound, $m_{\pi_D}>500$
GeV. Yet, when only the $\rho^0_D$ kinetically mixes with hypercharge, we find
the strongest LHC bound is $m_{\pi_D}>130$ GeV, that is only slightly better
than what LEP II achieved. We find the relative insensitivity of LHC searches,
especially at 13 TeV, can be blamed mainly on their penchant for high mass
objects or large MET. Dedicated searches would undoubtedly yield substantially
improved sensitivity. We provide a GitHub page to speed the implementation of
these searches in future LHC analyses. Our findings provide a strong motivation
for model-independent searches of the form $pp\to A\to B+C\to SM\, SM+SM\, SM$
where the theoretical prejudice is for SM to be a t,b,$\tau$ or W,Z,h.
| [
{
"created": "Wed, 26 Sep 2018 18:41:27 GMT",
"version": "v1"
},
{
"created": "Mon, 12 Nov 2018 23:24:57 GMT",
"version": "v2"
}
] | 2019-09-04 | [
[
"Kribs",
"Graham D.",
""
],
[
"Martin",
"Adam",
""
],
[
"Ostdiek",
"Bryan",
""
],
[
"Tong",
"Tom",
""
]
] | A new, strongly-coupled dark sector could be accessible to LHC searches now. These dark sectors consist of composites formed from constituents that are charged under the electroweak group and interact with the Higgs, but are neutral under Standard Model color. In these scenarios, the most promising target is the dark meson sector, consisting of dark vector-mesons as well as dark pions. In this paper we study dark meson production and decay at the LHC in theories that preserve a global SU(2) dark flavor symmetry. Dark pions can be pair-produced through resonant dark vector meson production, $p p\to\rho_D\to\pi_D\pi_D$, and decay in one of two distinct ways: gaugephobic, when $\pi_D\to f\bar{f}'$ generally dominates; or gaugephilic, when $\pi_D\to W+h,Z+h$ dominates once kinematically open. Unlike QCD, the decay $\pi^0_D\to\gamma\gamma$ is virtually absent due to the dark flavor symmetry. We recast a vast set of LHC searches to determine the current constraints on dark meson production and decay. When $m_{\rho_D}$ is slightly heavier than $2 m_{\pi_D}$ and $\rho_D^{\pm,0}$ kinetically mixes with the weak gauge bosons, the 8 TeV same-sign lepton search strategy sets the best bound, $m_{\pi_D}>500$ GeV. Yet, when only the $\rho^0_D$ kinetically mixes with hypercharge, we find the strongest LHC bound is $m_{\pi_D}>130$ GeV, that is only slightly better than what LEP II achieved. We find the relative insensitivity of LHC searches, especially at 13 TeV, can be blamed mainly on their penchant for high mass objects or large MET. Dedicated searches would undoubtedly yield substantially improved sensitivity. We provide a GitHub page to speed the implementation of these searches in future LHC analyses. Our findings provide a strong motivation for model-independent searches of the form $pp\to A\to B+C\to SM\, SM+SM\, SM$ where the theoretical prejudice is for SM to be a t,b,$\tau$ or W,Z,h. |
0704.3827 | Yin Furong | Furong Yin | Neutrino mixing matrix in the 3-3-1 model with heavy leptons and $A_4$
symmetry | 10 pages | Phys.Rev.D75:073010,2007 | 10.1103/PhysRevD.75.073010 | null | hep-ph | null | We study the lepton sector in the model based on the local gauge group
$SU(3)_c\otimes SU(3)_L\otimes U(1)_X$ which do not contain particles with
exotic electric charges. The seesaw mechanism and discrete $A_4$ symmetry are
introduced into the model to understand why neutrinos are especially light and
the observed pattern of neutrino mixing. The model provides a method for
obtaining the tri-bimaximal mixing matrix in the leading order. A non-zero
mixing angle $V_{e3}$ presents in the modified mixing matrix.
| [
{
"created": "Sun, 29 Apr 2007 05:41:59 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Yin",
"Furong",
""
]
] | We study the lepton sector in the model based on the local gauge group $SU(3)_c\otimes SU(3)_L\otimes U(1)_X$ which do not contain particles with exotic electric charges. The seesaw mechanism and discrete $A_4$ symmetry are introduced into the model to understand why neutrinos are especially light and the observed pattern of neutrino mixing. The model provides a method for obtaining the tri-bimaximal mixing matrix in the leading order. A non-zero mixing angle $V_{e3}$ presents in the modified mixing matrix. |
hep-ph/0611083 | Marcus Bluhm | M. Bluhm (Forschungszentrum Dresden-Rossendorf), B. Kampfer
(Forschungszentrum Dresden-Rossendorf & Dresden, Tech. U.) | Quasi-particle perspective on critical end-point | Nov 2006. 12 pp. Invited Talk given at Critical Point and Onset of
Deconfinement, Florence, Italy, 3-6 July 2006 | PoSCPOD2006:004,2006 | null | null | hep-ph | null | Within a quasi-particle model for the equation of state of strongly
interacting matter for two quark flavors we include phenomenologically features
of the QCD critical point and discuss its impact on the equation of state. In
particular, we investigate the influence on the quark number susceptibility and
the pattern of isentropic trajectories which describe the evolutionary paths of
matter during the hydrodynamical expansion of a heavy-ion collision.
| [
{
"created": "Tue, 7 Nov 2006 15:14:24 GMT",
"version": "v1"
}
] | 2009-04-14 | [
[
"Bluhm",
"M.",
"",
"Forschungszentrum Dresden-Rossendorf"
],
[
"Kampfer",
"B.",
"",
"Forschungszentrum Dresden-Rossendorf & Dresden, Tech. U."
]
] | Within a quasi-particle model for the equation of state of strongly interacting matter for two quark flavors we include phenomenologically features of the QCD critical point and discuss its impact on the equation of state. In particular, we investigate the influence on the quark number susceptibility and the pattern of isentropic trajectories which describe the evolutionary paths of matter during the hydrodynamical expansion of a heavy-ion collision. |
0907.3155 | Juan Antonio Aguilar-Saavedra | J. A. Aguilar-Saavedra | Identifying top partners at LHC | LaTeX 89 pages, 111 PS figures. Added one model to the analysis in
all final states, plus one subsection and some references. Final version to
appear in JHEP | null | 10.1088/1126-6708/2009/11/030 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We systematically study the possible signals at LHC of new vector-like quarks
mainly coupled to the third generation. We consider heavy quarks T, B, X, Y of
charges 2/3, -1/3, 5/3 and -4/3, respectively, in SU(2)_L isosinglets T_{L,R},
B_{L,R}, or isodoublets (T B)_{L,R}, (X T)_{L,R} or (B Y)_{L,R}. Analyses based
on a fast detector simulation are presented for twelve different final states
containing one, two, three or four charged leptons in several invariant mass
regions, also considering various b quark multiplicities. It is shown that with
the combination of the different channels the new quarks can be identified and
their charged and neutral decays established. The comparison among final states
also shows that the single lepton one offers the best discovery potential at
LHC. For heavy quark masses of 500 GeV, the 5 sigma discovery luminosities
range from 0.16 fb^-1 for a (X T)_{L,R} doublet to 1.9 fb^-1 for a B_{L,R}
singlet.
| [
{
"created": "Mon, 20 Jul 2009 14:20:41 GMT",
"version": "v1"
},
{
"created": "Mon, 5 Oct 2009 17:43:09 GMT",
"version": "v2"
}
] | 2015-05-13 | [
[
"Aguilar-Saavedra",
"J. A.",
""
]
] | We systematically study the possible signals at LHC of new vector-like quarks mainly coupled to the third generation. We consider heavy quarks T, B, X, Y of charges 2/3, -1/3, 5/3 and -4/3, respectively, in SU(2)_L isosinglets T_{L,R}, B_{L,R}, or isodoublets (T B)_{L,R}, (X T)_{L,R} or (B Y)_{L,R}. Analyses based on a fast detector simulation are presented for twelve different final states containing one, two, three or four charged leptons in several invariant mass regions, also considering various b quark multiplicities. It is shown that with the combination of the different channels the new quarks can be identified and their charged and neutral decays established. The comparison among final states also shows that the single lepton one offers the best discovery potential at LHC. For heavy quark masses of 500 GeV, the 5 sigma discovery luminosities range from 0.16 fb^-1 for a (X T)_{L,R} doublet to 1.9 fb^-1 for a B_{L,R} singlet. |
hep-ph/9602287 | Hans Lotter | V.S.Fadin, L.N.Lipatov | Next-to-leading Corrections to the BFKL Equation From the Gluon and
Quark Production | 39 pages, latex, 4 figures | Nucl.Phys. B477 (1996) 767-808 | 10.1016/0550-3213(96)00334-3 | DESY 96-020 | hep-ph | null | The gluon and quark production in the quasi-multi-Regge kinematics is
considered. The differential cross section for different helicity states is
calculated. The dimensional regularization is used to remove the infrared
divergencies in the corresponding contributions to the BFKL-equation. The other
next-to-leading corrections are discussed.
| [
{
"created": "Tue, 13 Feb 1996 12:49:10 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Fadin",
"V. S.",
""
],
[
"Lipatov",
"L. N.",
""
]
] | The gluon and quark production in the quasi-multi-Regge kinematics is considered. The differential cross section for different helicity states is calculated. The dimensional regularization is used to remove the infrared divergencies in the corresponding contributions to the BFKL-equation. The other next-to-leading corrections are discussed. |
1608.01995 | Sylvain Fichet | Sylvain Fichet, Gero von Gersdorff, Eduardo Ponton, Rogerio Rosenfeld | The Global Higgs as a Signal for Compositeness at the LHC | 27 pages, 7 figures. v2: Comments added. Matches JHEP version | null | 10.1007/JHEP01(2017)012 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The radial excitation of the global symmetry-breaking vacuum in composite
Higgs models, called the "global Higgs", has been recently a focus of
investigation. In this paper we study the prospects for detecting this
composite scalar at the 13 TeV LHC. We compute the global Higgs production
rates and estimate the discovery potential of a global Higgs decaying into top
quark pairs and into Higgs and electroweak gauge bosons with subsequent
hadronic decays. The global Higgs may also decay into fermion resonances such
as top partners, providing a new window into compositeness. We show that top
partner jets can be effectively unresolved in some regions of the parameter
space. Such "boosted top partner" signatures would deserve the development of
dedicated substructure analyses.
| [
{
"created": "Fri, 5 Aug 2016 20:00:00 GMT",
"version": "v1"
},
{
"created": "Fri, 6 Jan 2017 01:37:36 GMT",
"version": "v2"
}
] | 2017-02-01 | [
[
"Fichet",
"Sylvain",
""
],
[
"von Gersdorff",
"Gero",
""
],
[
"Ponton",
"Eduardo",
""
],
[
"Rosenfeld",
"Rogerio",
""
]
] | The radial excitation of the global symmetry-breaking vacuum in composite Higgs models, called the "global Higgs", has been recently a focus of investigation. In this paper we study the prospects for detecting this composite scalar at the 13 TeV LHC. We compute the global Higgs production rates and estimate the discovery potential of a global Higgs decaying into top quark pairs and into Higgs and electroweak gauge bosons with subsequent hadronic decays. The global Higgs may also decay into fermion resonances such as top partners, providing a new window into compositeness. We show that top partner jets can be effectively unresolved in some regions of the parameter space. Such "boosted top partner" signatures would deserve the development of dedicated substructure analyses. |
0910.5853 | Takumi Ito | Takumi Ito, Ryuichiro Kitano and Takeo Moroi | Measurement of the Superparticle Mass Spectrum in the Long-Lived Stau
Scenario at the LHC | 20 pages, 6 figures | JHEP 1004:017,2010 | 10.1007/JHEP04(2010)017 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In supersymmetric scenarios with a long-lived stau, the LHC experiments
provide us with a great environment for precise mass measurements of
superparticles. We study a case in which the mass differences between the
lightest stau and other sleptons are about 10 GeV or larger, so that the decay
products of heavier sleptons are hard enough to be detected. We demonstrate
that the masses of neutralinos, sleptons, and squarks can be measured with a
good accuracy.
| [
{
"created": "Fri, 30 Oct 2009 11:43:36 GMT",
"version": "v1"
}
] | 2014-11-20 | [
[
"Ito",
"Takumi",
""
],
[
"Kitano",
"Ryuichiro",
""
],
[
"Moroi",
"Takeo",
""
]
] | In supersymmetric scenarios with a long-lived stau, the LHC experiments provide us with a great environment for precise mass measurements of superparticles. We study a case in which the mass differences between the lightest stau and other sleptons are about 10 GeV or larger, so that the decay products of heavier sleptons are hard enough to be detected. We demonstrate that the masses of neutralinos, sleptons, and squarks can be measured with a good accuracy. |
1908.10270 | Edward Shuryak | Edward Shuryak | Light-front wave functions of mesons, baryons and pentaquarks, with
topology-induced local 4-quark interaction | v2 has two new figs, and discusses the issue of whether motion inside
nucleon resonances can be chaotic | Phys. Rev. D 100, 114018 (2019) | 10.1103/PhysRevD.100.114018 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We calculate light-front wave functions of mesons, baryons and pentaquarks in
a model including constituent mass (representing chiral symmetry breaking),
harmonic confining potential, and 4-quark local interaction of 't Hooft type.
The model is a simplified version of that used by Jia and Vary. The method used
is numerical diagonalization of the Hamiltonian matrix, with certain functional
basis. We found that the nucleon wave function displays strong diquar
correlations, unlike that for Delta (decuplet) baryon. We also calculate
3-quark-5-quark admixture to baryons, and the resulting antiquark sea PDF.
| [
{
"created": "Tue, 27 Aug 2019 15:23:21 GMT",
"version": "v1"
},
{
"created": "Fri, 27 Sep 2019 20:24:44 GMT",
"version": "v2"
}
] | 2019-12-18 | [
[
"Shuryak",
"Edward",
""
]
] | We calculate light-front wave functions of mesons, baryons and pentaquarks in a model including constituent mass (representing chiral symmetry breaking), harmonic confining potential, and 4-quark local interaction of 't Hooft type. The model is a simplified version of that used by Jia and Vary. The method used is numerical diagonalization of the Hamiltonian matrix, with certain functional basis. We found that the nucleon wave function displays strong diquar correlations, unlike that for Delta (decuplet) baryon. We also calculate 3-quark-5-quark admixture to baryons, and the resulting antiquark sea PDF. |
1409.6127 | Johan Bijnens | Johan Bijnens and Alexey A. Vladimirov (Lund) | Leading logarithms for the nucleon mass | 24p, misprints corrected, some minor reformulations | null | 10.1016/j.nuclphysb.2014.12.015 | LU TP 13-35 | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Within the heavy baryon chiral perturbation theory approach, we have studied
the leading logarithm behaviour of the nucleon mass up to four-loop order
exactly and we present some results up to six-loop order as well as an
all-order conjecture. The same methods allow to calculate the main logarithm
multiplying the terms with fractional powers of the quark mass. We calculate
thus the coefficients of $m^{2n+1}\log^{(n-1)}(\mu^2/m^2)$ and
$m^{2n+2}\log^n(\mu^2/m^2)$, with $m$ the lowest-order pion mass. A side result
is the leading divergence for a general heavy baryon loop integral.
| [
{
"created": "Mon, 22 Sep 2014 09:25:05 GMT",
"version": "v1"
},
{
"created": "Fri, 9 Jan 2015 07:35:07 GMT",
"version": "v2"
}
] | 2015-05-20 | [
[
"Bijnens",
"Johan",
"",
"Lund"
],
[
"Vladimirov",
"Alexey A.",
"",
"Lund"
]
] | Within the heavy baryon chiral perturbation theory approach, we have studied the leading logarithm behaviour of the nucleon mass up to four-loop order exactly and we present some results up to six-loop order as well as an all-order conjecture. The same methods allow to calculate the main logarithm multiplying the terms with fractional powers of the quark mass. We calculate thus the coefficients of $m^{2n+1}\log^{(n-1)}(\mu^2/m^2)$ and $m^{2n+2}\log^n(\mu^2/m^2)$, with $m$ the lowest-order pion mass. A side result is the leading divergence for a general heavy baryon loop integral. |
hep-ph/0406336 | Silvano Simula | P. Faccioli, D. Guadagnoli and S. Simula | The Neutron Electric Dipole Moment in the Instanton Vacuum: Quenched
Versus Unquenched Simulations | 8 pages, 3 figures, 2 tables | Phys.Rev. D70 (2004) 074017 | 10.1103/PhysRevD.70.074017 | Preprint ECT*-04-05, RM3-TH/04-15, ROME1-1379/2004 | hep-ph hep-lat | null | We investigate the role played by the fermionic determinant in the evaluation
of the CP-violating neutron electric dipole moment (EDM) adopting the Instanton
Liquid Model. Significant differences between quenched and unquenched
calculations are found. In the case of unquenched simulations the neutron EDM
decreases linearly with the quark mass and is expected to vanish in the chiral
limit. On the contrary, within the quenched approximation, the neutron EDM
increases as the quark mass decreases and is expected to diverge as (1/m)**Nf
in the chiral limit. We argue that such a qualitatively different behavior is a
parameter-free, semi-classical prediction and occurs because the neutron EDM is
sensitive to the topological structure of the vacuum. The present analysis
suggests that quenched and unquenched lattice QCD simulations of the neutron
EDM as well as of other observables governed by topology might show up
important differences in the quark mass dependence, for mq < Lambda(QCD).
| [
{
"created": "Wed, 30 Jun 2004 14:27:18 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Faccioli",
"P.",
""
],
[
"Guadagnoli",
"D.",
""
],
[
"Simula",
"S.",
""
]
] | We investigate the role played by the fermionic determinant in the evaluation of the CP-violating neutron electric dipole moment (EDM) adopting the Instanton Liquid Model. Significant differences between quenched and unquenched calculations are found. In the case of unquenched simulations the neutron EDM decreases linearly with the quark mass and is expected to vanish in the chiral limit. On the contrary, within the quenched approximation, the neutron EDM increases as the quark mass decreases and is expected to diverge as (1/m)**Nf in the chiral limit. We argue that such a qualitatively different behavior is a parameter-free, semi-classical prediction and occurs because the neutron EDM is sensitive to the topological structure of the vacuum. The present analysis suggests that quenched and unquenched lattice QCD simulations of the neutron EDM as well as of other observables governed by topology might show up important differences in the quark mass dependence, for mq < Lambda(QCD). |
hep-ph/9605418 | Juan Antonio Aguilar Saavedra | F. del Aguila, J. A. Aguilar-Saavedra | Invariant formulation of CP violation for four quark families | LaTeX, 10 pages, 2 PicTeX figures. PostScript also available at
http://deneb.ugr.es/papers/ugft62.ps.gz. Some typing errors corrected and a
reference updated. To be published in Phys. Lett. B | Phys.Lett. B386 (1996) 241-246 | 10.1016/0370-2693(96)00939-2 | UG-FT-62/96 | hep-ph | null | We find a minimal set of constraints which are independent of the choice of
weak quark basis and necessary and sufficient for CP conservation for four
quark families, including also the case of degenerate quark masses. These
invariant conditions are written in the mass eigenstate basis as a function of
the fermion masses and charged current mixings. CP violation is then related to
the areas of three unitarity quadrangles and the CP violating effects of the
fourth family are discussed in the case of small mixings.
| [
{
"created": "Tue, 28 May 1996 16:03:47 GMT",
"version": "v1"
},
{
"created": "Mon, 22 Jul 1996 15:50:42 GMT",
"version": "v2"
}
] | 2009-10-28 | [
[
"del Aguila",
"F.",
""
],
[
"Aguilar-Saavedra",
"J. A.",
""
]
] | We find a minimal set of constraints which are independent of the choice of weak quark basis and necessary and sufficient for CP conservation for four quark families, including also the case of degenerate quark masses. These invariant conditions are written in the mass eigenstate basis as a function of the fermion masses and charged current mixings. CP violation is then related to the areas of three unitarity quadrangles and the CP violating effects of the fourth family are discussed in the case of small mixings. |
0912.3175 | Dmitri Diakonov | Dmitri Diakonov (St. Petersburg NPI and Bochum University) | Exotic pentaquarks as Gamov-Teller resonances | 10 pages, 4 figures, extended version of the invited talk at Quark
Nuclear Physics 2009, Beijing, Sep. 21-26, 2009 | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | If the number of colors Nc is taken large, baryons and their excitations can
be considered in a mean-field approach. We argue that the mean field in baryons
breaks spontaneously the spherical and SU(3) flavor symmetries, but retains the
SU(2) symmetry of simultaneous rotations in space and isospace. The one-quark
and quark-hole excitations in the mean field, together with the SU(3)
rotational bands about them determine the spectrum of baryon resonances, which
turns out to be in satisfactory accordance with reality when one puts Nc=3. A
by-product of this scheme is a confirmation of the light pentaquark baryon
Theta+ = uudds-bar as a typical Gamov-Teller resonance long known in nuclear
physics. An extension of the same large-Nc logic to charmed (and bottom)
baryons leads to a prediction of a anti-decapenta (15-bar)-plet of charmed
pentaquarks, two of which, Beta++_c = cuuds-bar and Beta+_c = cudds-bar, may be
light and stable with respect to strong decays, and should be looked for.
| [
{
"created": "Wed, 16 Dec 2009 16:16:40 GMT",
"version": "v1"
},
{
"created": "Fri, 19 Feb 2010 16:41:30 GMT",
"version": "v2"
}
] | 2010-02-19 | [
[
"Diakonov",
"Dmitri",
"",
"St. Petersburg NPI and Bochum University"
]
] | If the number of colors Nc is taken large, baryons and their excitations can be considered in a mean-field approach. We argue that the mean field in baryons breaks spontaneously the spherical and SU(3) flavor symmetries, but retains the SU(2) symmetry of simultaneous rotations in space and isospace. The one-quark and quark-hole excitations in the mean field, together with the SU(3) rotational bands about them determine the spectrum of baryon resonances, which turns out to be in satisfactory accordance with reality when one puts Nc=3. A by-product of this scheme is a confirmation of the light pentaquark baryon Theta+ = uudds-bar as a typical Gamov-Teller resonance long known in nuclear physics. An extension of the same large-Nc logic to charmed (and bottom) baryons leads to a prediction of a anti-decapenta (15-bar)-plet of charmed pentaquarks, two of which, Beta++_c = cuuds-bar and Beta+_c = cudds-bar, may be light and stable with respect to strong decays, and should be looked for. |
1610.05101 | Rafal Maciula | Antoni Szczurek and Rafal Maciula | Four-jet production in the $k_t$-factorisation | 9 pages, 8 figures, invited talk given by Antoni Szczurek at the
Low-X Meeting 2016, 6-11 June 2016, K\'aroly R\'obert College, Gy\"ongy\"os,
Hungary. arXiv admin note: substantial text overlap with arXiv:1606.09067 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss the single-parton and double-parton scattering (SPS or DPS)
effects in four-jet production at the LHC. The calculations of both
single-parton and double-parton scattering components are done in the
high-energy (or $k_{T}$)-factorization approach. Here we follow our recent
developments of relevant methods and tools. The calculations are performed for
kinematical situations relevant for two experimental measurements (ATLAS and
CMS) at the LHC. We compare our results to those reported by the ATLAS and CMS
collaborations for different sets of kinematical cuts. A special attention is
given to the optimization of kinematical conditions in order to enhance the
relative contribution of DPS in four-jet sample. Several differential
distributions are calculated and carefully discussed in the context of recent
and future searches for DPS effects at the LHC. The dependences of the relative
DPS amount is studied as a function of rapidity of jets, rapidity distance, and
various azimuthal correlations between jets. The regions with an enhanced DPS
contribution are identified.
| [
{
"created": "Mon, 17 Oct 2016 13:20:51 GMT",
"version": "v1"
}
] | 2016-10-18 | [
[
"Szczurek",
"Antoni",
""
],
[
"Maciula",
"Rafal",
""
]
] | We discuss the single-parton and double-parton scattering (SPS or DPS) effects in four-jet production at the LHC. The calculations of both single-parton and double-parton scattering components are done in the high-energy (or $k_{T}$)-factorization approach. Here we follow our recent developments of relevant methods and tools. The calculations are performed for kinematical situations relevant for two experimental measurements (ATLAS and CMS) at the LHC. We compare our results to those reported by the ATLAS and CMS collaborations for different sets of kinematical cuts. A special attention is given to the optimization of kinematical conditions in order to enhance the relative contribution of DPS in four-jet sample. Several differential distributions are calculated and carefully discussed in the context of recent and future searches for DPS effects at the LHC. The dependences of the relative DPS amount is studied as a function of rapidity of jets, rapidity distance, and various azimuthal correlations between jets. The regions with an enhanced DPS contribution are identified. |
2311.01548 | Ramon Winterhalder | Theo Heimel, Nathan Huetsch, Fabio Maltoni, Olivier Mattelaer, Tilman
Plehn, Ramon Winterhalder | The MadNIS Reloaded | 15 pages, 6 figures, 2 tables; v3: updates incl. referee requests | SciPost Phys. 17, 023 (2024) | 10.21468/SciPostPhys.17.1.023 | IRMP-CP3-23-56, MCNET-23-12 | hep-ph hep-ex physics.comp-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In pursuit of precise and fast theory predictions for the LHC, we present an
implementation of the MadNIS method in the MadGraph event generator. A series
of improvements in MadNIS further enhance its efficiency and speed. We validate
this implementation for realistic partonic processes and find significant gains
from using modern machine learning in event generators.
| [
{
"created": "Thu, 2 Nov 2023 19:00:01 GMT",
"version": "v1"
},
{
"created": "Thu, 16 Nov 2023 09:33:11 GMT",
"version": "v2"
},
{
"created": "Fri, 31 May 2024 14:01:59 GMT",
"version": "v3"
}
] | 2024-07-31 | [
[
"Heimel",
"Theo",
""
],
[
"Huetsch",
"Nathan",
""
],
[
"Maltoni",
"Fabio",
""
],
[
"Mattelaer",
"Olivier",
""
],
[
"Plehn",
"Tilman",
""
],
[
"Winterhalder",
"Ramon",
""
]
] | In pursuit of precise and fast theory predictions for the LHC, we present an implementation of the MadNIS method in the MadGraph event generator. A series of improvements in MadNIS further enhance its efficiency and speed. We validate this implementation for realistic partonic processes and find significant gains from using modern machine learning in event generators. |
0910.5692 | Babette D\"obrich | Babette D\"obrich and Holger Gies | Interferometry in pulsed fields | 4 pages, 2 figures. Contribution to 5th Patras workshop on Axions,
WIMPs and WISPs, IPPP Durham, 13-17 July 2009 | null | null | null | hep-ph gr-qc | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss the particle-physics discovery potential of ground-based
gravitational-wave interferometers. With the use of pulsed magnetic fields,
current and future gravitational-wave interferometers could not only be
utilized to observe phenomena of strong-field QED, but they could also be
applied to sweep the parameter space of particles of the hidden sector.
| [
{
"created": "Thu, 29 Oct 2009 17:45:19 GMT",
"version": "v1"
}
] | 2009-11-02 | [
[
"Döbrich",
"Babette",
""
],
[
"Gies",
"Holger",
""
]
] | We discuss the particle-physics discovery potential of ground-based gravitational-wave interferometers. With the use of pulsed magnetic fields, current and future gravitational-wave interferometers could not only be utilized to observe phenomena of strong-field QED, but they could also be applied to sweep the parameter space of particles of the hidden sector. |
2203.16665 | Jorge L\'opez | Carolina M. Robles Gajardo, Alberto Accardi, Mark D. Baker, William K.
Brooks, Rapha\"el Dupr\'e, Mathieu Ehrhart, Jorge A. L\'opez, Zhoudunming Tu | Low Energy Protons as Probes of Hadronization Dynamics | 12 pages, 4 figures, Physical Review C 106, 045202 (2022) | Physical Review C 106, 045202 (2022) | 10.1103/PhysRevC.106.045202 | null | hep-ph hep-ex nucl-ex | http://creativecommons.org/licenses/by/4.0/ | Energetic quarks liberated from hadrons in nuclear deep-inelastic scattering
propagate through the nuclear medium, interacting with it via several
processes. These include quark energy loss and nuclear interactions of forming
hadrons. One manifestation of these interactions is the enhanced emission of
low-energy charged particles, referred to as grey tracks. We use the
theoretical components of the BeAGLE event generator to interpret grey track
signatures of parton transport and hadron formation by comparing its
predictions to E665 data. We extend the base version of BeAGLE by adding four
different options for describing parton energy loss. The E665 data we used
consists of multiplicity ratios for fixed-target scattering of 490 GeV muons on
Xe normalized to deuterium as a function of the number of grey tracks. We
compare multiplicity ratios for E665 grey tracks to the predictions of BeAGLE,
varying the options and parameters to determine which physics phenomena can be
identified by these data. We find that grey tracks are unaffected by
modifications of the forward production. Thus their production must be
dominated by interactions with hadrons in the backward region. This offers the
advantage that selecting certain particles in the forward region is unlikely to
bias a centrality selection. We see a strong correlation between the number of
grey tracks and the in-medium path length. Our energy loss model does not
reproduce the suppression observed in the projectile region. We see an
underprediction of the proton production rate in backward kinematics,
suggesting that a stronger source of interaction with the nuclear medium is
needed for accurate modeling. These results lay an important foundation for
future spectator tagging studies at both Jefferson Lab and at the Electron-Ion
Collider, where neutron and proton grey track studies will be feasible down to
very small momenta.
| [
{
"created": "Wed, 30 Mar 2022 20:39:14 GMT",
"version": "v1"
},
{
"created": "Thu, 20 Oct 2022 07:53:35 GMT",
"version": "v2"
}
] | 2022-10-21 | [
[
"Gajardo",
"Carolina M. Robles",
""
],
[
"Accardi",
"Alberto",
""
],
[
"Baker",
"Mark D.",
""
],
[
"Brooks",
"William K.",
""
],
[
"Dupré",
"Raphaël",
""
],
[
"Ehrhart",
"Mathieu",
""
],
[
"López",
"Jorge A.",
""
],
[
"Tu",
"Zhoudunming",
""
]
] | Energetic quarks liberated from hadrons in nuclear deep-inelastic scattering propagate through the nuclear medium, interacting with it via several processes. These include quark energy loss and nuclear interactions of forming hadrons. One manifestation of these interactions is the enhanced emission of low-energy charged particles, referred to as grey tracks. We use the theoretical components of the BeAGLE event generator to interpret grey track signatures of parton transport and hadron formation by comparing its predictions to E665 data. We extend the base version of BeAGLE by adding four different options for describing parton energy loss. The E665 data we used consists of multiplicity ratios for fixed-target scattering of 490 GeV muons on Xe normalized to deuterium as a function of the number of grey tracks. We compare multiplicity ratios for E665 grey tracks to the predictions of BeAGLE, varying the options and parameters to determine which physics phenomena can be identified by these data. We find that grey tracks are unaffected by modifications of the forward production. Thus their production must be dominated by interactions with hadrons in the backward region. This offers the advantage that selecting certain particles in the forward region is unlikely to bias a centrality selection. We see a strong correlation between the number of grey tracks and the in-medium path length. Our energy loss model does not reproduce the suppression observed in the projectile region. We see an underprediction of the proton production rate in backward kinematics, suggesting that a stronger source of interaction with the nuclear medium is needed for accurate modeling. These results lay an important foundation for future spectator tagging studies at both Jefferson Lab and at the Electron-Ion Collider, where neutron and proton grey track studies will be feasible down to very small momenta. |
1504.01309 | Roman Pasechnik | Roman Pasechnik, Boris Kopeliovich and Irina Potashnikova | Diffractive Bremsstrahlung in Hadronic Collisions | 29 pages, 16 figures; typos corrected; references added; minor
corrections | Adv. High Energy Phys. 2015 (2015) 701467 | 10.1155/2015/701467 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Production of heavy photons (Drell-Yan), gauge bosons, Higgs bosons, heavy
flavors, which is treated within the QCD parton model as a result of hard
parton-parton collision, can be considered as a bremsstrahlung process in the
target rest frame. In this review, we discuss the basic features of the
diffractive channels of these processes in the framework of color dipole
approach. The main observation is a dramatic breakdown of diffractive QCD
factorisation due to the interplay between soft and hard interactions, which
dominates these processes. This observation is crucial for phenomenological
studies of diffractive reactions in high-energy hadronic collisions.
| [
{
"created": "Mon, 6 Apr 2015 15:52:32 GMT",
"version": "v1"
},
{
"created": "Sun, 7 Jun 2015 14:36:46 GMT",
"version": "v2"
},
{
"created": "Sun, 6 Sep 2015 15:32:21 GMT",
"version": "v3"
}
] | 2015-09-08 | [
[
"Pasechnik",
"Roman",
""
],
[
"Kopeliovich",
"Boris",
""
],
[
"Potashnikova",
"Irina",
""
]
] | Production of heavy photons (Drell-Yan), gauge bosons, Higgs bosons, heavy flavors, which is treated within the QCD parton model as a result of hard parton-parton collision, can be considered as a bremsstrahlung process in the target rest frame. In this review, we discuss the basic features of the diffractive channels of these processes in the framework of color dipole approach. The main observation is a dramatic breakdown of diffractive QCD factorisation due to the interplay between soft and hard interactions, which dominates these processes. This observation is crucial for phenomenological studies of diffractive reactions in high-energy hadronic collisions. |
2305.12033 | Mariusz Przybycien | Krzysztof Piotrzkowski and Mariusz Przybycien | High energy bremsstrahlung at the FCC-ee, FCC-eh and LHeC | null | null | null | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | Bremsstrahlung spectra will be strongly distorted due to small lateral beam
sizes at future colliders. That in turn will have large consequences for the
electron and positron beam lifetimes as well as for the luminosity measurements
in the case of electron-hadron colliders. We discuss in detail such
consequences for the Future Circular Collider and Large Hadron electron
Collider cases.
| [
{
"created": "Fri, 19 May 2023 23:15:56 GMT",
"version": "v1"
},
{
"created": "Thu, 13 Jul 2023 17:45:34 GMT",
"version": "v2"
},
{
"created": "Sun, 3 Sep 2023 22:06:09 GMT",
"version": "v3"
}
] | 2024-03-20 | [
[
"Piotrzkowski",
"Krzysztof",
""
],
[
"Przybycien",
"Mariusz",
""
]
] | Bremsstrahlung spectra will be strongly distorted due to small lateral beam sizes at future colliders. That in turn will have large consequences for the electron and positron beam lifetimes as well as for the luminosity measurements in the case of electron-hadron colliders. We discuss in detail such consequences for the Future Circular Collider and Large Hadron electron Collider cases. |
2012.10492 | Javier Fuentes-Mart\'in | Javier Fuentes-Martin, Gino Isidori, Julie Pag\`es, Ben A. Stefanek | Flavor Non-universal Pati-Salam Unification and Neutrino Masses | 14 pages, 2 figures | null | 10.1016/j.physletb.2021.136484 | MITP/20-083, ZU-TH-56/20 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We analyze the neutrino mass spectrum and discuss the extra-dimensional
interpretation of a three-site Pati-Salam model which i) unifies all families
of quark and leptons, ii) provides a natural description of the Standard Model
Yukawa couplings, iii) could account for the recent $B$-physics anomalies. The
key feature of the model is a breaking of the Pati-Salam and electroweak gauge
symmetries localized on opposite sites, communicated to the other sites in an
attenuated manner via nearest-neighbor interactions. We show that in this
context gauge-singlet fermions localized on each site, receiving hierarchical
Majorana masses, can allow the implementation of an inverse seesaw mechanism
leading to light anarchic neutrino masses consistent with data. The continuum
limit of this three-site setup has a natural interpretation in terms of a
warped extra dimension with three defects, where the required exponential
hierarchies can be achieved from $\mathcal{O}(1)$ differences in the bulk field
masses.
| [
{
"created": "Fri, 18 Dec 2020 20:00:05 GMT",
"version": "v1"
}
] | 2021-07-07 | [
[
"Fuentes-Martin",
"Javier",
""
],
[
"Isidori",
"Gino",
""
],
[
"Pagès",
"Julie",
""
],
[
"Stefanek",
"Ben A.",
""
]
] | We analyze the neutrino mass spectrum and discuss the extra-dimensional interpretation of a three-site Pati-Salam model which i) unifies all families of quark and leptons, ii) provides a natural description of the Standard Model Yukawa couplings, iii) could account for the recent $B$-physics anomalies. The key feature of the model is a breaking of the Pati-Salam and electroweak gauge symmetries localized on opposite sites, communicated to the other sites in an attenuated manner via nearest-neighbor interactions. We show that in this context gauge-singlet fermions localized on each site, receiving hierarchical Majorana masses, can allow the implementation of an inverse seesaw mechanism leading to light anarchic neutrino masses consistent with data. The continuum limit of this three-site setup has a natural interpretation in terms of a warped extra dimension with three defects, where the required exponential hierarchies can be achieved from $\mathcal{O}(1)$ differences in the bulk field masses. |
1010.3736 | Robert Shrock | Ning Chen, Thomas A. Ryttov, and Robert Shrock | Patterns of Dynamical Gauge Symmetry Breaking | 14 pages, latex | Phys.Rev.D82:116006,2010 | 10.1103/PhysRevD.82.116006 | YITP-SB-10-32 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We construct and analyze theories with a gauge symmetry in the ultraviolet of
the form $G \otimes G_b$, in which the vectorial, asymptotically free $G_b$
gauge interaction becomes strongly coupled at a scale where the $G$ interaction
is weakly coupled and produces bilinear fermion condensates that dynamically
break the $G$ symmetry. Comparisons are given between Higgs and dynamical
symmetry breaking mechanisms for various models.
| [
{
"created": "Mon, 18 Oct 2010 21:10:49 GMT",
"version": "v1"
}
] | 2011-01-17 | [
[
"Chen",
"Ning",
""
],
[
"Ryttov",
"Thomas A.",
""
],
[
"Shrock",
"Robert",
""
]
] | We construct and analyze theories with a gauge symmetry in the ultraviolet of the form $G \otimes G_b$, in which the vectorial, asymptotically free $G_b$ gauge interaction becomes strongly coupled at a scale where the $G$ interaction is weakly coupled and produces bilinear fermion condensates that dynamically break the $G$ symmetry. Comparisons are given between Higgs and dynamical symmetry breaking mechanisms for various models. |
hep-ph/9808381 | Dan-Olof Riska | D. O. Riska | The Strange Magnetic Moment of the Proton in the Chiral Quark Model | Typos corrected | Few Body Syst.Suppl.10:415-418,1999 | null | null | hep-ph | null | The strange magnetic moment of the proton is small in the chiral quark model,
because of a near cancellation between the quantum fluctuations that involve
kaons and $s$-quarks and loops that involve radiative transitions between
strange vector mesons and kaons.
| [
{
"created": "Fri, 21 Aug 1998 12:50:47 GMT",
"version": "v1"
},
{
"created": "Fri, 9 Oct 1998 12:39:04 GMT",
"version": "v2"
}
] | 2011-04-15 | [
[
"Riska",
"D. O.",
""
]
] | The strange magnetic moment of the proton is small in the chiral quark model, because of a near cancellation between the quantum fluctuations that involve kaons and $s$-quarks and loops that involve radiative transitions between strange vector mesons and kaons. |
1404.7741 | Francesca Day | Joseph P. Conlon and Francesca V. Day | 3.55 keV photon lines from axion to photon conversion in the Milky Way
and M31 | 15 pages, 7 figures Version accepted for publication in JCAP | JCAP11(2014)033 | 10.1088/1475-7516/2014/11/033 | null | hep-ph astro-ph.CO astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We further explore a scenario in which the recently observed 3.55 keV photon
line arises from dark matter decay to an axion-like particle (ALP) of energy
3.55 keV, which then converts to a photon in astrophysical magnetic fields.
This ALP scenario is well-motivated by the observed morphology of the 3.55 keV
flux. For this scenario we study the expected flux from dark matter decay in
the galactic halos of both the Milky Way and Andromeda (M31). The Milky Way
magnetic field is asymmetric about the galactic centre, and so the resulting
3.55 keV flux morphology differs significantly from the case of direct dark
matter decay to photons. However the Milky Way magnetic field is not large
enough to generate an observable signal, even with ASTRO-H. In contrast, M31
has optimal conditions for ALP to photon conversion and the intrinsic signal
from M31 becomes two orders of magnitude larger than for the Milky Way,
comparable to that from clusters and consistent with observations.
| [
{
"created": "Wed, 30 Apr 2014 14:41:47 GMT",
"version": "v1"
},
{
"created": "Mon, 24 Nov 2014 10:44:22 GMT",
"version": "v2"
}
] | 2014-11-25 | [
[
"Conlon",
"Joseph P.",
""
],
[
"Day",
"Francesca V.",
""
]
] | We further explore a scenario in which the recently observed 3.55 keV photon line arises from dark matter decay to an axion-like particle (ALP) of energy 3.55 keV, which then converts to a photon in astrophysical magnetic fields. This ALP scenario is well-motivated by the observed morphology of the 3.55 keV flux. For this scenario we study the expected flux from dark matter decay in the galactic halos of both the Milky Way and Andromeda (M31). The Milky Way magnetic field is asymmetric about the galactic centre, and so the resulting 3.55 keV flux morphology differs significantly from the case of direct dark matter decay to photons. However the Milky Way magnetic field is not large enough to generate an observable signal, even with ASTRO-H. In contrast, M31 has optimal conditions for ALP to photon conversion and the intrinsic signal from M31 becomes two orders of magnitude larger than for the Milky Way, comparable to that from clusters and consistent with observations. |
2402.17789 | Bogdan Damski | Bogdan Damski | Reference frame dependence of the periodically oscillating Coulomb field
in the Proca theory | 8 pp | null | null | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The Proca theory of the real massive vector field admits non-equilibrium
solutions, where the asymptotic dynamics of the electric field is dominated by
the periodically oscillating Coulomb component. We discuss how such field
configurations are seen in different reference frames, where we find an
intriguing spatial pattern of the vector field and the electromagnetic field
associated with it. Our studies are carried out in the framework of the
classical Proca theory.
| [
{
"created": "Mon, 26 Feb 2024 10:32:44 GMT",
"version": "v1"
}
] | 2024-03-29 | [
[
"Damski",
"Bogdan",
""
]
] | The Proca theory of the real massive vector field admits non-equilibrium solutions, where the asymptotic dynamics of the electric field is dominated by the periodically oscillating Coulomb component. We discuss how such field configurations are seen in different reference frames, where we find an intriguing spatial pattern of the vector field and the electromagnetic field associated with it. Our studies are carried out in the framework of the classical Proca theory. |
1205.2283 | Diptimoy Ghosh | Diptimoy Ghosh, Monoranjan Guchait, Sreerup Raychaudhuri, Dipan
Sengupta | How Constrained is the cMSSM? | 28 pages, 5 figures, some clarifications added, version to appear in
Phys.Rev.D | null | 10.1103/PhysRevD.86.055007 | TIFR/TH/12-15 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the allowed parameter space of the constrained minimal
supersymmetric Standard Model (cMSSM) in the light of direct searches,
constraints from $B$-physics (including the recent measurement of the branching
ratio for $B_s \to \mu^+\mu^-$) and the dark matter relic density. For low or
moderate values of $\tan\beta$, the strongest constraints are those imposed by
direct searches, and therefore, large areas of the parameter space are still
allowed. In the large $\tan \beta$ limit, however, the $B$-physics constraints
are more restrictive, effectively forcing the squark and gluino masses to lie
close to or above a TeV. A light Higgs boson could dramatically change the
allowed parameter space, but we need to know its mass precisely for this to be
effective. We emphasize that it is still too early to write off the cMSSM, even
in the large $\tan\beta$ limit. Finally we explore strategies to extend the LHC
search for cMSSM signals beyond the present reach of the ATLAS and CMS
Collaborations.
| [
{
"created": "Thu, 10 May 2012 14:53:04 GMT",
"version": "v1"
},
{
"created": "Wed, 1 Aug 2012 16:44:02 GMT",
"version": "v2"
}
] | 2013-05-30 | [
[
"Ghosh",
"Diptimoy",
""
],
[
"Guchait",
"Monoranjan",
""
],
[
"Raychaudhuri",
"Sreerup",
""
],
[
"Sengupta",
"Dipan",
""
]
] | We study the allowed parameter space of the constrained minimal supersymmetric Standard Model (cMSSM) in the light of direct searches, constraints from $B$-physics (including the recent measurement of the branching ratio for $B_s \to \mu^+\mu^-$) and the dark matter relic density. For low or moderate values of $\tan\beta$, the strongest constraints are those imposed by direct searches, and therefore, large areas of the parameter space are still allowed. In the large $\tan \beta$ limit, however, the $B$-physics constraints are more restrictive, effectively forcing the squark and gluino masses to lie close to or above a TeV. A light Higgs boson could dramatically change the allowed parameter space, but we need to know its mass precisely for this to be effective. We emphasize that it is still too early to write off the cMSSM, even in the large $\tan\beta$ limit. Finally we explore strategies to extend the LHC search for cMSSM signals beyond the present reach of the ATLAS and CMS Collaborations. |
1810.07113 | Abhiram Kaushik Badrinarayanan | Rohini M. Godbole, Abhiram Kaushik, Anuradha Misra, Siddhesh Padval | Probing the Gluon Sivers Function through direct photon production at
RHIC | 32 pages, 7 figures, v3: Version published in Phys. Rev. D.
Discussion of BSR based results updated. References added | Phys. Rev. D 99, 014003 (2019) | 10.1103/PhysRevD.99.014003 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the production of prompt-photons at RHIC in the context of a
generalised parton model framework, with a view to obtain information on the
gluon Sivers function (GSF). At RHIC energy ($\sqrt{s}=200$ GeV), the Compton
process, $gq\to\gamma q$ contributes significantly to the production of
direct-photons at midrapidity and dominates it in the negative (backward)
rapdity region. We find that for direct photons, asymmetries of upto 10\% are
allowed by a maximal gluon Sivers function. However, the asymmetry obtained
using existing fits of the GSF available is literature is negligible. We also
estimate the impact that photons produced via fragmentation can have on the
signal and find that their inclusion can dilute the asymmetry by between
10-50\% of the direct-photon value. Finally, using the Colour-Gauge Invariant
generalised parton model (CGI-GPM) approach, we consider the effects of initial
state and final state interactions which can affect the universality of the
Sivers functions in different processes. We find that the inclusion of these
effects leads to the size of the gluon contributions being roughly halved.
However, in the backward region which we are interested in, the sizes of the
quark contributions are suppressed even further, leading to increased dominance
of the gluon contributions.
| [
{
"created": "Tue, 16 Oct 2018 16:12:58 GMT",
"version": "v1"
},
{
"created": "Fri, 19 Oct 2018 14:09:00 GMT",
"version": "v2"
},
{
"created": "Mon, 14 Jan 2019 04:11:45 GMT",
"version": "v3"
}
] | 2019-01-15 | [
[
"Godbole",
"Rohini M.",
""
],
[
"Kaushik",
"Abhiram",
""
],
[
"Misra",
"Anuradha",
""
],
[
"Padval",
"Siddhesh",
""
]
] | We study the production of prompt-photons at RHIC in the context of a generalised parton model framework, with a view to obtain information on the gluon Sivers function (GSF). At RHIC energy ($\sqrt{s}=200$ GeV), the Compton process, $gq\to\gamma q$ contributes significantly to the production of direct-photons at midrapidity and dominates it in the negative (backward) rapdity region. We find that for direct photons, asymmetries of upto 10\% are allowed by a maximal gluon Sivers function. However, the asymmetry obtained using existing fits of the GSF available is literature is negligible. We also estimate the impact that photons produced via fragmentation can have on the signal and find that their inclusion can dilute the asymmetry by between 10-50\% of the direct-photon value. Finally, using the Colour-Gauge Invariant generalised parton model (CGI-GPM) approach, we consider the effects of initial state and final state interactions which can affect the universality of the Sivers functions in different processes. We find that the inclusion of these effects leads to the size of the gluon contributions being roughly halved. However, in the backward region which we are interested in, the sizes of the quark contributions are suppressed even further, leading to increased dominance of the gluon contributions. |
hep-ph/0305198 | Pedro Bicudo | P. Bicudo and G. Marques | Chiral Symmetry Breaking with Scalar Confinement | 4 pages, 5 figures, contribution to the XXXVIIIth Rencontres de
Moriond QCD and High Energy Hadronic Interactions | Phys.Rev. D70 (2004) 094047 | 10.1103/PhysRevD.70.094047 | null | hep-ph | null | Spontaneous chiral symmetry breaking is accepted to occur in low energy
hadronic physics, resulting in the several successful theorems of PCAC. On the
other hand scalar confinement is suggested both by the spectroscopy of hadrons
and by the string picture of confinement. However these two evidences are
apparently conflicting, because chiral symmetry breaking requires a chiral
invariant coupling to the quarks, say a vector coupling like in QCD. Here we
reformulate the coupling of the quarks to the string, and we are able to comply
with chiral symmetry breaking, using scalar confinement. The results are quite
encouraging.
| [
{
"created": "Sun, 18 May 2003 02:18:55 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Bicudo",
"P.",
""
],
[
"Marques",
"G.",
""
]
] | Spontaneous chiral symmetry breaking is accepted to occur in low energy hadronic physics, resulting in the several successful theorems of PCAC. On the other hand scalar confinement is suggested both by the spectroscopy of hadrons and by the string picture of confinement. However these two evidences are apparently conflicting, because chiral symmetry breaking requires a chiral invariant coupling to the quarks, say a vector coupling like in QCD. Here we reformulate the coupling of the quarks to the string, and we are able to comply with chiral symmetry breaking, using scalar confinement. The results are quite encouraging. |
hep-ph/0111198 | Diego Restrepo | Diego Restrepo | Phenomenology of Bilinear Broken R-parity | 115pp, Ph.D Thesis, Universitat de Valencia | null | null | null | hep-ph | null | The straightforward supersymmetrization of the Standard Model (SM) results in
a phenomenologically inconsistent theory in which Baryon number ($B$) and
Lepton number ($L$) are violated by dimension 4 operators, inducing fast proton
decay. Proton stability allows only for separate $L$ or $B$ violation and, if
neutrinos are massive Majorana particles, $L$ violating terms must be present.
In this thesis I will study a Supersymmetric Standard Model (SSM) realization
with $B$ conservation and minimal $L$ violation. In this framework $L$ is
mildly violated only by super-renormalizable terms, allowing for small neutrino
Majorana masses. This model is more predictive than the Baryon-Parity SSM. The
induced dimension 4 $L$ violating couplings are not arbitrary, and
automatically satisfy all experimental constraints. After introducing the
theoretical framework for supersymmetric models without Lepton number, I will
discuss the phenomenology of the (unstable) lightest neutralino and of the
lightest stop. I will show that the leptonic decays of the stop can be related
to the neutrino parameters, and in particular their measurement can indirectly
probe the size of the solar neutrinos mixing angle.
| [
{
"created": "Thu, 15 Nov 2001 19:54:16 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Restrepo",
"Diego",
""
]
] | The straightforward supersymmetrization of the Standard Model (SM) results in a phenomenologically inconsistent theory in which Baryon number ($B$) and Lepton number ($L$) are violated by dimension 4 operators, inducing fast proton decay. Proton stability allows only for separate $L$ or $B$ violation and, if neutrinos are massive Majorana particles, $L$ violating terms must be present. In this thesis I will study a Supersymmetric Standard Model (SSM) realization with $B$ conservation and minimal $L$ violation. In this framework $L$ is mildly violated only by super-renormalizable terms, allowing for small neutrino Majorana masses. This model is more predictive than the Baryon-Parity SSM. The induced dimension 4 $L$ violating couplings are not arbitrary, and automatically satisfy all experimental constraints. After introducing the theoretical framework for supersymmetric models without Lepton number, I will discuss the phenomenology of the (unstable) lightest neutralino and of the lightest stop. I will show that the leptonic decays of the stop can be related to the neutrino parameters, and in particular their measurement can indirectly probe the size of the solar neutrinos mixing angle. |
hep-ph/9504427 | Ann Nelson | Patrick Huet and Ann E. Nelson (University of Washington) | CP Violation and Electroweak Baryogenesis in Extensions of the Standard
Model | 16 pages, 3 Postscript figures included as uuencoded file, uses
phyzzx and epsf, typo and figure 3b corrected, conclusions unchanged | Phys.Lett.B355:229-235,1995 | 10.1016/0370-2693(95)00674-A | preprint no. UW-PTH-95-03 | hep-ph | null | We develop a new and general method to calculate the effects of \cp\
violation from extensions of the standard model on the mechanism of electroweak
baryogenesis. We illustrate its applicability in the framework of two-higgs
doublet models.
| [
{
"created": "Sat, 29 Apr 1995 00:07:15 GMT",
"version": "v1"
},
{
"created": "Wed, 3 May 1995 18:21:47 GMT",
"version": "v2"
},
{
"created": "Mon, 5 Jun 1995 22:04:15 GMT",
"version": "v3"
},
{
"created": "Tue, 20 Jun 1995 19:01:19 GMT",
"version": "v4"
}
] | 2009-07-09 | [
[
"Huet",
"Patrick",
"",
"University of Washington"
],
[
"Nelson",
"Ann E.",
"",
"University of Washington"
]
] | We develop a new and general method to calculate the effects of \cp\ violation from extensions of the standard model on the mechanism of electroweak baryogenesis. We illustrate its applicability in the framework of two-higgs doublet models. |
1011.0937 | Zbigniew Was | N. Davidson, T. Przedzinski, Z. Was | PHOTOS Interface in C++; Technical and Physics Documentation | Updated version; for the program as of April 2015 | null | null | CERN-PH-TH/2010-261, IFJPAN-IV-2010-6 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | For five years now, PHOTOS Monte Carlo for bremsstrahlung in the decay of
particles and resonances has been available with an interface to the C++ HepMC
event record. The main purpose of the present paper is to document the
technical aspects of the PHOTOS Monte Carlo installation and present version
use. A multitude of test results and examples are distributed together with the
program code.
The PHOTOS C++ physics precision is better than its FORTRAN predecessor and
more convenient steering options are also available. An algorithm for the event
record interface necessary for process dependent photon emission kernel is
implemented. It is used in Z and W decays for kernels of complete first order
matrix elements of the decays. Additional emission of final state lepton pairs
is also available.
Physics assumptions used in the program and properties of the solution are
reviewed. In particular, it is explained how the second order matrix elements
were used in design and validation of the program iteration procedure. Also, it
is explained that the phase space parametrization used in the program is exact.
| [
{
"created": "Wed, 3 Nov 2010 16:52:01 GMT",
"version": "v1"
},
{
"created": "Tue, 28 Apr 2015 05:46:59 GMT",
"version": "v2"
}
] | 2015-04-29 | [
[
"Davidson",
"N.",
""
],
[
"Przedzinski",
"T.",
""
],
[
"Was",
"Z.",
""
]
] | For five years now, PHOTOS Monte Carlo for bremsstrahlung in the decay of particles and resonances has been available with an interface to the C++ HepMC event record. The main purpose of the present paper is to document the technical aspects of the PHOTOS Monte Carlo installation and present version use. A multitude of test results and examples are distributed together with the program code. The PHOTOS C++ physics precision is better than its FORTRAN predecessor and more convenient steering options are also available. An algorithm for the event record interface necessary for process dependent photon emission kernel is implemented. It is used in Z and W decays for kernels of complete first order matrix elements of the decays. Additional emission of final state lepton pairs is also available. Physics assumptions used in the program and properties of the solution are reviewed. In particular, it is explained how the second order matrix elements were used in design and validation of the program iteration procedure. Also, it is explained that the phase space parametrization used in the program is exact. |
1609.07490 | Andreas Goudelis | Daniele Barducci, Aoife Bharucha, Nishita Desai, Michele Frigerio,
Benjamin Fuks, Andreas Goudelis, Suchita Kulkarni, Giacomo Polesello and
Dipan Sengupta | Monojet searches for momentum-dependent dark matter interactions | 23 pages, 4 figures | JHEP 1701 (2017) 078 | 10.1007/JHEP01(2017)078 | LAPTH-041/16 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider minimal dark matter scenarios featuring momentum-dependent
couplings of the dark sector to the Standard Model. We derive constraints from
existing LHC searches in the monojet channel, estimate the future LHC
sensitivity for an integrated luminosity of 300 fb$^{-1}$, and compare with
models exhibiting conventional momentum-independent interactions with the dark
sector. In addition to being well motivated by (composite) pseudo-Goldstone
dark matter scenarios, momentum-dependent couplings are interesting as they
weaken direct detection constraints. For a specific dark matter mass, the LHC
turns out to be sensitive to smaller signal cross-sections in the
momentum-dependent case, by virtue of the harder jet transverse-momentum
distribution.
| [
{
"created": "Fri, 23 Sep 2016 20:00:06 GMT",
"version": "v1"
}
] | 2017-01-24 | [
[
"Barducci",
"Daniele",
""
],
[
"Bharucha",
"Aoife",
""
],
[
"Desai",
"Nishita",
""
],
[
"Frigerio",
"Michele",
""
],
[
"Fuks",
"Benjamin",
""
],
[
"Goudelis",
"Andreas",
""
],
[
"Kulkarni",
"Suchita",
""
],
[
"Polesello",
"Giacomo",
""
],
[
"Sengupta",
"Dipan",
""
]
] | We consider minimal dark matter scenarios featuring momentum-dependent couplings of the dark sector to the Standard Model. We derive constraints from existing LHC searches in the monojet channel, estimate the future LHC sensitivity for an integrated luminosity of 300 fb$^{-1}$, and compare with models exhibiting conventional momentum-independent interactions with the dark sector. In addition to being well motivated by (composite) pseudo-Goldstone dark matter scenarios, momentum-dependent couplings are interesting as they weaken direct detection constraints. For a specific dark matter mass, the LHC turns out to be sensitive to smaller signal cross-sections in the momentum-dependent case, by virtue of the harder jet transverse-momentum distribution. |
hep-ph/0511273 | Yadong Yang | Wenjun Li, Yadong Yang, Xiangdan Zhang | \tau^- \to \mu^- \pi^0(\eta,\eta') Decays in New Physics Scenarios
beyond the Standard Model | 18 pages, 7 eps figures. Hadronic uncertainties considered and
references added | Phys.Rev. D73 (2006) 073005 | 10.1103/PhysRevD.73.073005 | null | hep-ph | null | The semileptonic decays $\tau^- \to \mu^- M (M=\pi^0,\eta,\eta')$ could be
sensitive probe for new physics scenarios with lepton flavor violation(LFV).
Motivated by the recent Belle measurement, we investigate these decays in type
III two-Higgs-doublet model (2HDM III), R-parity violating supersymmetric
models(RPV SUSY) and flavor changing $Z'$ models with family non-universal
couplings, respectively. In these new physics scenarios, there are LFV
couplings at tree level. Our results have shown that the decays are very
sensitive to the LFV couplings and could be enhanced to the present
experimental sensitivities. We have derived strong bounds on relevant couplings
of these models, which may be useful for further relevant studies.
| [
{
"created": "Wed, 23 Nov 2005 14:22:00 GMT",
"version": "v1"
},
{
"created": "Wed, 22 Feb 2006 12:12:16 GMT",
"version": "v2"
}
] | 2009-11-11 | [
[
"Li",
"Wenjun",
""
],
[
"Yang",
"Yadong",
""
],
[
"Zhang",
"Xiangdan",
""
]
] | The semileptonic decays $\tau^- \to \mu^- M (M=\pi^0,\eta,\eta')$ could be sensitive probe for new physics scenarios with lepton flavor violation(LFV). Motivated by the recent Belle measurement, we investigate these decays in type III two-Higgs-doublet model (2HDM III), R-parity violating supersymmetric models(RPV SUSY) and flavor changing $Z'$ models with family non-universal couplings, respectively. In these new physics scenarios, there are LFV couplings at tree level. Our results have shown that the decays are very sensitive to the LFV couplings and could be enhanced to the present experimental sensitivities. We have derived strong bounds on relevant couplings of these models, which may be useful for further relevant studies. |
hep-ph/9404314 | null | Thomas E. Browder (University of Hawaii at Manoa), Klaus Honscheid
(Ohio State University), Stephen Playfer (Syracuse University) | A Review of Hadronic and Rare B Decays | 77 pages; CLNS 93/1261, UH-511-778-93, OHSTPY-HEP-E-93-018, HEPSY
93-10 | null | 10.1142/9789814503846_0004 | null | hep-ph hep-ex | null | We review recent experimental results on B meson decays. These include
measurements of the inclusive production of charmed and non-charmed mesons and
baryons, the reconstruction of a large number of exclusive hadronic final
states with charmed mesons, the search for exclusive hadronic final states
without charmed mesons, and the first observation of the decay B-> K* gamma
which is described by an electromagnetic penguin diagram. The theoretical
implications of these results will be considered. The figures can be obtained
in postscript format EMAIL from kh@ohstpy.mps.ohio-state.edu.
| [
{
"created": "Thu, 21 Apr 1994 14:04:37 GMT",
"version": "v1"
}
] | 2016-11-03 | [
[
"Browder",
"Thomas E.",
"",
"University of Hawaii at Manoa"
],
[
"Honscheid",
"Klaus",
"",
"Ohio State University"
],
[
"Playfer",
"Stephen",
"",
"Syracuse University"
]
] | We review recent experimental results on B meson decays. These include measurements of the inclusive production of charmed and non-charmed mesons and baryons, the reconstruction of a large number of exclusive hadronic final states with charmed mesons, the search for exclusive hadronic final states without charmed mesons, and the first observation of the decay B-> K* gamma which is described by an electromagnetic penguin diagram. The theoretical implications of these results will be considered. The figures can be obtained in postscript format EMAIL from kh@ohstpy.mps.ohio-state.edu. |
1002.3527 | David d'Enterria | Mario Deile, David d'Enterria, Albert De Roeck, M.G. Albrow, A. Alkin,
E. Avsar, V.A. Bednyakov, R. Brower, A. Bunyatyan, H. Burkhardt, A. Caldwell,
W. Carvalho, M. Chaichian, E. Chapon, Z. Conesa del Valle, J.R. Cudell, J.
Dainton, M. Deak, M. Djuric, K. Eggert, S. Eidelman, J. Ellis, E. Ferreira,
J. Forshaw, S. Giani, E. Gotsman, K. Goulianos, R. Granier de Cassagnac, P.
Grafstrom, A. Grebenyuk, B. Grube, F. Hautmann, S. Heinemeyer, M. Heller, J.
Hoerandel, J. Hollar, P. Hoyer, K. Huitu, D.S. Hwang, M.M. Islam, L.L.
Jenkovszky, H. Jung, V. Juranek, A. Kaidalov, J. Kaspar, J. Keates, O. Kepka,
L. Khein, V.A. Khoze, T. Kodama, A.K. Kohara, H. Kowalski, V. Kundrat, K.
Kutak, T. Lappi, L. Lipatov, M. Lokajicek, I.P. Lokhtin, R.J. Luddy, G.I.
Lykasov, V.V. Lyuboshitz, V.L. Lyuboshitz, V.V. Lyubushkin, T.V. Lyubushkina,
A.K. Managadze, U. Maor, P. Marage, A. Martin, E. Martynov, S. Marzani, C.
Mesropian, P. Newman, G. Niewiadomski, R.S. Pasechnik, L. Lipatov, V. Pauk,
V. Petrov, T. Pierog, A.D. Pilkington, J. Pinfold, M. Poghosyan, A.V.
Prokudin, A. Proskuryakov, J. Rojo, E. Romanets, D.A. Ross, C. Royon, G.
Ruggiero, M.G. Ryskin, K. Safarik, L.I. Sarycheva, R. Schicker, F.
Schwennsen, O.V. Selyugin, A.M. Snigirev, J. Soffer, T Stanev, M. Strikman,
A. Szczurek, C.-.I Tan, M. Tasevsky, O.V. Teryaev, A. Tricomi, S.M. Troshin,
N.E. Tyurin, G. Watt, G. Weiglein, K. Werner, S. Yaschenko | 13th International Conference on Elastic and Diffractive Scattering
(Blois Workshop) - Moving Forward into the LHC Era | 511 pages. Proceedings of the 13th International Conference on
Elastic and Diffractive Scattering, CERN, Geneva, June-July 2009 | CERN-Proceedings-2010-002 | null | null | hep-ph astro-ph.HE hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Proceedings of the 13th International Conference on Elastic and Diffractive
Scattering (Blois Workshop) - Moving Forward into the LHC Era
| [
{
"created": "Wed, 17 Feb 2010 23:38:06 GMT",
"version": "v1"
},
{
"created": "Tue, 8 Feb 2011 22:14:54 GMT",
"version": "v2"
}
] | 2011-02-11 | [
[
"Deile",
"Mario",
""
],
[
"d'Enterria",
"David",
""
],
[
"De Roeck",
"Albert",
""
],
[
"Albrow",
"M. G.",
""
],
[
"Alkin",
"A.",
""
],
[
"Avsar",
"E.",
""
],
[
"Bednyakov",
"V. A.",
""
],
[
"Brower",
"R.",
""
],
[
"Bunyatyan",
"A.",
""
],
[
"Burkhardt",
"H.",
""
],
[
"Caldwell",
"A.",
""
],
[
"Carvalho",
"W.",
""
],
[
"Chaichian",
"M.",
""
],
[
"Chapon",
"E.",
""
],
[
"del Valle",
"Z. Conesa",
""
],
[
"Cudell",
"J. R.",
""
],
[
"Dainton",
"J.",
""
],
[
"Deak",
"M.",
""
],
[
"Djuric",
"M.",
""
],
[
"Eggert",
"K.",
""
],
[
"Eidelman",
"S.",
""
],
[
"Ellis",
"J.",
""
],
[
"Ferreira",
"E.",
""
],
[
"Forshaw",
"J.",
""
],
[
"Giani",
"S.",
""
],
[
"Gotsman",
"E.",
""
],
[
"Goulianos",
"K.",
""
],
[
"de Cassagnac",
"R. Granier",
""
],
[
"Grafstrom",
"P.",
""
],
[
"Grebenyuk",
"A.",
""
],
[
"Grube",
"B.",
""
],
[
"Hautmann",
"F.",
""
],
[
"Heinemeyer",
"S.",
""
],
[
"Heller",
"M.",
""
],
[
"Hoerandel",
"J.",
""
],
[
"Hollar",
"J.",
""
],
[
"Hoyer",
"P.",
""
],
[
"Huitu",
"K.",
""
],
[
"Hwang",
"D. S.",
""
],
[
"Islam",
"M. M.",
""
],
[
"Jenkovszky",
"L. L.",
""
],
[
"Jung",
"H.",
""
],
[
"Juranek",
"V.",
""
],
[
"Kaidalov",
"A.",
""
],
[
"Kaspar",
"J.",
""
],
[
"Keates",
"J.",
""
],
[
"Kepka",
"O.",
""
],
[
"Khein",
"L.",
""
],
[
"Khoze",
"V. A.",
""
],
[
"Kodama",
"T.",
""
],
[
"Kohara",
"A. K.",
""
],
[
"Kowalski",
"H.",
""
],
[
"Kundrat",
"V.",
""
],
[
"Kutak",
"K.",
""
],
[
"Lappi",
"T.",
""
],
[
"Lipatov",
"L.",
""
],
[
"Lokajicek",
"M.",
""
],
[
"Lokhtin",
"I. P.",
""
],
[
"Luddy",
"R. J.",
""
],
[
"Lykasov",
"G. I.",
""
],
[
"Lyuboshitz",
"V. V.",
""
],
[
"Lyuboshitz",
"V. L.",
""
],
[
"Lyubushkin",
"V. V.",
""
],
[
"Lyubushkina",
"T. V.",
""
],
[
"Managadze",
"A. K.",
""
],
[
"Maor",
"U.",
""
],
[
"Marage",
"P.",
""
],
[
"Martin",
"A.",
""
],
[
"Martynov",
"E.",
""
],
[
"Marzani",
"S.",
""
],
[
"Mesropian",
"C.",
""
],
[
"Newman",
"P.",
""
],
[
"Niewiadomski",
"G.",
""
],
[
"Pasechnik",
"R. S.",
""
],
[
"Lipatov",
"L.",
""
],
[
"Pauk",
"V.",
""
],
[
"Petrov",
"V.",
""
],
[
"Pierog",
"T.",
""
],
[
"Pilkington",
"A. D.",
""
],
[
"Pinfold",
"J.",
""
],
[
"Poghosyan",
"M.",
""
],
[
"Prokudin",
"A. V.",
""
],
[
"Proskuryakov",
"A.",
""
],
[
"Rojo",
"J.",
""
],
[
"Romanets",
"E.",
""
],
[
"Ross",
"D. A.",
""
],
[
"Royon",
"C.",
""
],
[
"Ruggiero",
"G.",
""
],
[
"Ryskin",
"M. G.",
""
],
[
"Safarik",
"K.",
""
],
[
"Sarycheva",
"L. I.",
""
],
[
"Schicker",
"R.",
""
],
[
"Schwennsen",
"F.",
""
],
[
"Selyugin",
"O. V.",
""
],
[
"Snigirev",
"A. M.",
""
],
[
"Soffer",
"J.",
""
],
[
"Stanev",
"T",
""
],
[
"Strikman",
"M.",
""
],
[
"Szczurek",
"A.",
""
],
[
"Tan",
"C. -. I",
""
],
[
"Tasevsky",
"M.",
""
],
[
"Teryaev",
"O. V.",
""
],
[
"Tricomi",
"A.",
""
],
[
"Troshin",
"S. M.",
""
],
[
"Tyurin",
"N. E.",
""
],
[
"Watt",
"G.",
""
],
[
"Weiglein",
"G.",
""
],
[
"Werner",
"K.",
""
],
[
"Yaschenko",
"S.",
""
]
] | Proceedings of the 13th International Conference on Elastic and Diffractive Scattering (Blois Workshop) - Moving Forward into the LHC Era |
hep-ph/9312309 | Michel Talon | Michel Talon | Quantum theory for the Standard Model | Latex file 37 pages | null | null | null | hep-ph | null | These lectures present some basic facts in field theory necessary to
understand the quantum theory of the Standard Model of weak and electromagnetic
interactions.
| [
{
"created": "Mon, 20 Dec 1993 15:34:53 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Talon",
"Michel",
""
]
] | These lectures present some basic facts in field theory necessary to understand the quantum theory of the Standard Model of weak and electromagnetic interactions. |
1705.05307 | Gui-Jun Ding | Gui-Jun Ding, Stephen F. King, Cai-Chang Li | Golden Littlest Seesaw | 32 pages, 7 figures | null | 10.1016/j.nuclphysb.2017.10.019 | USTC-ICTS-17-05 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose and analyse a new class of Littlest Seesaw models, with two
right-handed neutrinos in their diagonal mass basis, based on preserving the
first column of the Golden Ratio mixing matrix. We perform an exhaustive
analysis of all possible remnant symmetries of the group $A_5$ which can be
used to enforce various vacuum alignments for the flavon controlling solar
mixing, for two simple cases of the atmospheric flavon vacuum alignment. The
solar and atmospheric flavon vacuum alignments are enforced by {\em different}
remnant symmetries. We examine the phenomenological viability of each of the
possible Littlest Seesaw alignments in $A_5$, which preserve the first column
of the Golden ratio mixing matrix, using figures and extensive tables of
benchmark points and comparing our predictions to a recent global analysis of
neutrino data. We also repeat the analysis for an alternative form of Golden
Ratio mixing matrix.
| [
{
"created": "Mon, 15 May 2017 15:55:22 GMT",
"version": "v1"
}
] | 2018-03-14 | [
[
"Ding",
"Gui-Jun",
""
],
[
"King",
"Stephen F.",
""
],
[
"Li",
"Cai-Chang",
""
]
] | We propose and analyse a new class of Littlest Seesaw models, with two right-handed neutrinos in their diagonal mass basis, based on preserving the first column of the Golden Ratio mixing matrix. We perform an exhaustive analysis of all possible remnant symmetries of the group $A_5$ which can be used to enforce various vacuum alignments for the flavon controlling solar mixing, for two simple cases of the atmospheric flavon vacuum alignment. The solar and atmospheric flavon vacuum alignments are enforced by {\em different} remnant symmetries. We examine the phenomenological viability of each of the possible Littlest Seesaw alignments in $A_5$, which preserve the first column of the Golden ratio mixing matrix, using figures and extensive tables of benchmark points and comparing our predictions to a recent global analysis of neutrino data. We also repeat the analysis for an alternative form of Golden Ratio mixing matrix. |
hep-ph/0301280 | Shevchenko V. | V.I.Shevchenko | A remark on the short distance potential in gluodynamics | LaTeX, 16 pages, no figures | null | null | null | hep-ph | null | The structure of leading nonperturbative corrections to the static Coulomb
potential in QCD at small distances is analyzed. We argue in favor of the
correction linearly dependent on distance and remark that lattice measurements
of static potential for charges in higher representations can distinguish
between different phenomenological models used to describe it. Related problems
of validity of Dirac quantization condition for running charges in abelian
theory and significance of the quantity <A^2> are briefly discussed.
| [
{
"created": "Fri, 31 Jan 2003 20:52:00 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Shevchenko",
"V. I.",
""
]
] | The structure of leading nonperturbative corrections to the static Coulomb potential in QCD at small distances is analyzed. We argue in favor of the correction linearly dependent on distance and remark that lattice measurements of static potential for charges in higher representations can distinguish between different phenomenological models used to describe it. Related problems of validity of Dirac quantization condition for running charges in abelian theory and significance of the quantity <A^2> are briefly discussed. |
hep-ph/0309251 | Polina Cherzor | P. Cherzor | Code generation (automatized programming) of symbolic formulae for
helicity amplitudes | 13 pages, LaTeX, axodraw.sty | null | null | null | hep-ph | null | We propose a project for automatic representation and evaluation of helicity
amplitudes we started to develop and explain it's main functioning principles.
| [
{
"created": "Mon, 22 Sep 2003 17:48:57 GMT",
"version": "v1"
},
{
"created": "Fri, 26 Sep 2003 14:34:17 GMT",
"version": "v2"
},
{
"created": "Wed, 1 Oct 2003 13:45:19 GMT",
"version": "v3"
}
] | 2007-05-23 | [
[
"Cherzor",
"P.",
""
]
] | We propose a project for automatic representation and evaluation of helicity amplitudes we started to develop and explain it's main functioning principles. |
1609.01591 | Sven Bjarke Gudnason | Sven Bjarke Gudnason, Baiyang Zhang, Nana Ma | Generalized Skyrme model with the loosely bound potential | RevTeX: 33 pages, 14 figures; V2: comments and references added | Phys. Rev. D 94, 125004 (2016) | 10.1103/PhysRevD.94.125004 | null | hep-ph hep-th nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study a generalization of the loosely bound Skyrme model which consists of
the Skyrme model with a sixth-order derivative term - motivated by its
fluid-like properties - and the second-order loosely bound potential -
motivated by lowering the classical binding energies of higher-charged
Skyrmions. We use the rational map approximation for the Skyrmion of
topological charge B=4, calculate the binding energy of the latter and estimate
the systematic error in using this approximation. In the parameter space that
we can explore within the rational map approximation, we find classical binding
energies as low as 1.8% and once taking into account the contribution from
spin-isospin quantization we obtain binding energies as low as 5.3%. We also
calculate the contribution from the sixth-order derivative term to the electric
charge density and axial coupling.
| [
{
"created": "Tue, 6 Sep 2016 15:01:19 GMT",
"version": "v1"
},
{
"created": "Fri, 2 Dec 2016 10:58:15 GMT",
"version": "v2"
}
] | 2016-12-05 | [
[
"Gudnason",
"Sven Bjarke",
""
],
[
"Zhang",
"Baiyang",
""
],
[
"Ma",
"Nana",
""
]
] | We study a generalization of the loosely bound Skyrme model which consists of the Skyrme model with a sixth-order derivative term - motivated by its fluid-like properties - and the second-order loosely bound potential - motivated by lowering the classical binding energies of higher-charged Skyrmions. We use the rational map approximation for the Skyrmion of topological charge B=4, calculate the binding energy of the latter and estimate the systematic error in using this approximation. In the parameter space that we can explore within the rational map approximation, we find classical binding energies as low as 1.8% and once taking into account the contribution from spin-isospin quantization we obtain binding energies as low as 5.3%. We also calculate the contribution from the sixth-order derivative term to the electric charge density and axial coupling. |
hep-ph/0703015 | Stephen West | Anders Basboll, David Maybury, Francesco Riva, and Stephen M. West | Non-Perturbative Flat Direction Decay | 7 pages, 2 figures. References added, version for Phys. Rev. D | Phys.Rev.D76:065005,2007 | 10.1103/PhysRevD.76.065005 | OUTP-0702P | hep-ph | null | We argue that supersymmetric flat direction vacuum expectation values can
decay non-perturbatively via preheating. Considering a toy U(1) gauge theory,
we explicitly calculate the scalar potential, in the unitary gauge, for
excitations around several flat directions. We show that the mass matrix for
the excitations has non-diagonal entries which vary with the phase of the flat
direction vacuum expectation value. Furthermore, this mass matrix has zero
eigenvalues whose eigenstates change with time. We show that these light
degrees of freedom are produced copiously in the non-perturbative decay of the
flat direction vacuum expectation value.
| [
{
"created": "Thu, 1 Mar 2007 19:48:14 GMT",
"version": "v1"
},
{
"created": "Fri, 18 May 2007 16:19:28 GMT",
"version": "v2"
},
{
"created": "Thu, 14 Feb 2008 10:19:59 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Basboll",
"Anders",
""
],
[
"Maybury",
"David",
""
],
[
"Riva",
"Francesco",
""
],
[
"West",
"Stephen M.",
""
]
] | We argue that supersymmetric flat direction vacuum expectation values can decay non-perturbatively via preheating. Considering a toy U(1) gauge theory, we explicitly calculate the scalar potential, in the unitary gauge, for excitations around several flat directions. We show that the mass matrix for the excitations has non-diagonal entries which vary with the phase of the flat direction vacuum expectation value. Furthermore, this mass matrix has zero eigenvalues whose eigenstates change with time. We show that these light degrees of freedom are produced copiously in the non-perturbative decay of the flat direction vacuum expectation value. |
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