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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
2307.10769 | Chandrodoy Chattopadhyay | Chandrodoy Chattopadhyay, Ulrich Heinz, and Thomas Schaefer | Fluid dynamics from the Boltzmann equation using a maximum entropy
distribution | 30 pages, 19 figures (added new references; a couple of minor
corrections made in text) | null | null | null | hep-ph nucl-th | http://creativecommons.org/licenses/by/4.0/ | Using the recently developed ``Maximum Entropy'' (or ``least biased'')
distribution function to truncate the moment hierarchy arising from kinetic
theory, we formulate a far-from-equilibrium macroscopic theory that provides
the possibility of describing both free-streaming and hydrodynamic regimes of
heavy-ion collisions within a single framework. Unlike traditional hydrodynamic
theories that include viscous corrections to finite order, the present
formulation incorporates contributions to all orders in shear and bulk inverse
Reynolds numbers, allowing it to handle large dissipative fluxes. By
considering flow profiles relevant for heavy-ion collisions (Bjorken and Gubser
flows), we demonstrate that the present approach provides excellent agreement
with underlying kinetic theory throughout the fluid's evolution and,
especially, in far-off-equilibrium regimes where traditional hydrodynamics
breaks down.
| [
{
"created": "Thu, 20 Jul 2023 10:57:37 GMT",
"version": "v1"
},
{
"created": "Tue, 1 Aug 2023 22:34:43 GMT",
"version": "v2"
}
] | 2023-08-03 | [
[
"Chattopadhyay",
"Chandrodoy",
""
],
[
"Heinz",
"Ulrich",
""
],
[
"Schaefer",
"Thomas",
""
]
] | Using the recently developed ``Maximum Entropy'' (or ``least biased'') distribution function to truncate the moment hierarchy arising from kinetic theory, we formulate a far-from-equilibrium macroscopic theory that provides the possibility of describing both free-streaming and hydrodynamic regimes of heavy-ion collisions within a single framework. Unlike traditional hydrodynamic theories that include viscous corrections to finite order, the present formulation incorporates contributions to all orders in shear and bulk inverse Reynolds numbers, allowing it to handle large dissipative fluxes. By considering flow profiles relevant for heavy-ion collisions (Bjorken and Gubser flows), we demonstrate that the present approach provides excellent agreement with underlying kinetic theory throughout the fluid's evolution and, especially, in far-off-equilibrium regimes where traditional hydrodynamics breaks down. |
1210.4192 | Francesco Giacosa | Francesco Giacosa and Giuseppe Pagliara | Spectral function of a scalar boson coupled to fermions | 25 pages, 6 figures | Phys. Rev. D 88, 025010 (2013) | 10.1103/PhysRevD.88.025010 | null | hep-ph hep-th quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the calculation of the spectral function of an unstable scalar
boson coupled to fermions as resulting from the resummation of the one loop
diagrams in the scalar particle self energy. We work with a large but finite
high-energy cutoff: in this way, the spectral function of the scalar field is
always correctly normalized to unity, independently on the value of the cutoff.
We show that this high energy cutoff affects the Breit-Wigner width of the
unstable particle: the larger the cutoff, the smaller is the width at fixed
coupling. Thus, the existence of a high energy cutoff (alias minimal length),
and for instance the possible opening of new degrees of freedom beyond that
energy scale, could then be in principle proven by measuring, at lower energy
scales, the line shape of the unstable scalar state. Although the Lagrangian
here considered represents only a toy-model, we discuss possible future
extensions of our work which could be relevant for particle physics
phenomenology.
| [
{
"created": "Mon, 15 Oct 2012 20:56:58 GMT",
"version": "v1"
},
{
"created": "Mon, 26 Aug 2013 19:19:50 GMT",
"version": "v2"
}
] | 2013-08-27 | [
[
"Giacosa",
"Francesco",
""
],
[
"Pagliara",
"Giuseppe",
""
]
] | We present the calculation of the spectral function of an unstable scalar boson coupled to fermions as resulting from the resummation of the one loop diagrams in the scalar particle self energy. We work with a large but finite high-energy cutoff: in this way, the spectral function of the scalar field is always correctly normalized to unity, independently on the value of the cutoff. We show that this high energy cutoff affects the Breit-Wigner width of the unstable particle: the larger the cutoff, the smaller is the width at fixed coupling. Thus, the existence of a high energy cutoff (alias minimal length), and for instance the possible opening of new degrees of freedom beyond that energy scale, could then be in principle proven by measuring, at lower energy scales, the line shape of the unstable scalar state. Although the Lagrangian here considered represents only a toy-model, we discuss possible future extensions of our work which could be relevant for particle physics phenomenology. |
1112.1958 | Kresimir Kumericki | Kresimir Kumericki, Dieter Mueller, Andreas Schafer | Parametrizing Compton form factors with neural networks | LaTeX, 6 pages, 3 figures, Presented by K.K. at Ringberg HERA
workshop | null | 10.1016/j.nuclphysbps.2012.03.020 | null | hep-ph physics.data-an | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We describe a method, based on neural networks, of revealing Compton form
factors in the deeply virtual region. We compare this approach to standard
least-squares model fitting both for a simplified toy case and for HERMES data.
| [
{
"created": "Thu, 8 Dec 2011 21:01:23 GMT",
"version": "v1"
}
] | 2015-06-03 | [
[
"Kumericki",
"Kresimir",
""
],
[
"Mueller",
"Dieter",
""
],
[
"Schafer",
"Andreas",
""
]
] | We describe a method, based on neural networks, of revealing Compton form factors in the deeply virtual region. We compare this approach to standard least-squares model fitting both for a simplified toy case and for HERMES data. |
1806.08254 | Marc P. Bellon | Marc P. Bellon and Pierre J. Clavier | Analyticity domain of a Quantum Field Theory and Accelero-summation | 6 pages | null | 10.1007/s11005-019-01172-0 | null | hep-ph hep-th math-ph math.MP | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | From 't Hooft's argument, one expects that the analyticity domain of an
asymptotically free quantum field theory is horned shaped. In the usual Borel
summation, the function is obtained through a Laplace transform and thus has a
much larger analyticity domain. However, if the summation process goes through
the process called acceleration by Ecalle, one obtains such a horn shaped
analyticity domain. We therefore argue that acceleration, which allows to go
beyond standard Borel summation, must be an integral part of the toolkit for
the study of exactly renormalisable quantum field theories. We sketch how this
procedure is working and what are its consequences.
| [
{
"created": "Thu, 21 Jun 2018 14:09:19 GMT",
"version": "v1"
}
] | 2019-05-01 | [
[
"Bellon",
"Marc P.",
""
],
[
"Clavier",
"Pierre J.",
""
]
] | From 't Hooft's argument, one expects that the analyticity domain of an asymptotically free quantum field theory is horned shaped. In the usual Borel summation, the function is obtained through a Laplace transform and thus has a much larger analyticity domain. However, if the summation process goes through the process called acceleration by Ecalle, one obtains such a horn shaped analyticity domain. We therefore argue that acceleration, which allows to go beyond standard Borel summation, must be an integral part of the toolkit for the study of exactly renormalisable quantum field theories. We sketch how this procedure is working and what are its consequences. |
hep-ph/0301205 | Ji-Feng Yang | Ji-Feng Yang, Jie Zhou and Chen Wu (ECNU, Shanghai) | Numerical evaluation of a two loop diagram in the cutoff regularization | 6 pages, revtex, to appear in Comm. Theor. Phys | Commun.Theor.Phys. 40 (2003) 461-465 | 10.1088/0253-6102/40/4/461 | null | hep-ph hep-th nucl-th | null | The sunset diagram of $\lambda\phi^4$ theory is evaluated numerically in
cutoff scheme and a nonzero finite term (in accordance with dimensional
regularization (DR) result) is found in contrast to published calculations.
This finding dramatically reduces the critical couplings for symmetry breaking
in the two loop effective potential discussed in our previous work.
| [
{
"created": "Thu, 23 Jan 2003 16:50:34 GMT",
"version": "v1"
},
{
"created": "Tue, 12 Aug 2003 04:10:19 GMT",
"version": "v2"
}
] | 2018-01-17 | [
[
"Yang",
"Ji-Feng",
"",
"ECNU, Shanghai"
],
[
"Zhou",
"Jie",
"",
"ECNU, Shanghai"
],
[
"Wu",
"Chen",
"",
"ECNU, Shanghai"
]
] | The sunset diagram of $\lambda\phi^4$ theory is evaluated numerically in cutoff scheme and a nonzero finite term (in accordance with dimensional regularization (DR) result) is found in contrast to published calculations. This finding dramatically reduces the critical couplings for symmetry breaking in the two loop effective potential discussed in our previous work. |
0901.2818 | Thorsten Renk | Thorsten Renk | A comparison study of medium-modified QCD shower evolution scenarios | 15 pages, 10 figures, minor changes | Phys.Rev.C79:054906,2009 | 10.1103/PhysRevC.79.054906 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The computation of hard processes in hadronic collisions is a major success
of perturbative Quantum Chromodynamics (pQCD). In such processes, pQCD not only
predicts the hard reaction itself, but also the subsequent evolution in terms
of parton branching and radiation, leading to a parton shower and ultimately to
an observable jet of hadrons. If the hard process occurs in a heavy-ion
collision, a large part of this evolution takes place in the soft medium
created along with the hard reaction. An observation of jets in heavy-ion
collision thus allows a study of medium-modified QCD shower evolution. In
vacuum, Monte-Carlo (MC) simulations are well established tools to describe
such showers. For jet studies in heavy-ion collisions, MC models for in-medium
showers are currently being developed. However, the shower-medium interaction
depends on the nature of the microscopic degrees of freedom of the medium
created in a heavy-ion collision which is the very object one would like to
investigate. This paper presents a study in comparison between three different
possible implementations for the shower-medium interaction, two of them based
on medium-induced pQCD radiation, one of them a medium-induced drag force, and
shows for which observables differences between the three scenarios become
visible. We find that while single hadron observables such as R_AA are
incapable of differentiating between the scenarios, jet observables such as the
longiudinal momentum spectrum of hadrons in the jet show the potential to do
so.
| [
{
"created": "Mon, 19 Jan 2009 11:13:47 GMT",
"version": "v1"
},
{
"created": "Wed, 28 Jan 2009 09:19:56 GMT",
"version": "v2"
}
] | 2010-01-15 | [
[
"Renk",
"Thorsten",
""
]
] | The computation of hard processes in hadronic collisions is a major success of perturbative Quantum Chromodynamics (pQCD). In such processes, pQCD not only predicts the hard reaction itself, but also the subsequent evolution in terms of parton branching and radiation, leading to a parton shower and ultimately to an observable jet of hadrons. If the hard process occurs in a heavy-ion collision, a large part of this evolution takes place in the soft medium created along with the hard reaction. An observation of jets in heavy-ion collision thus allows a study of medium-modified QCD shower evolution. In vacuum, Monte-Carlo (MC) simulations are well established tools to describe such showers. For jet studies in heavy-ion collisions, MC models for in-medium showers are currently being developed. However, the shower-medium interaction depends on the nature of the microscopic degrees of freedom of the medium created in a heavy-ion collision which is the very object one would like to investigate. This paper presents a study in comparison between three different possible implementations for the shower-medium interaction, two of them based on medium-induced pQCD radiation, one of them a medium-induced drag force, and shows for which observables differences between the three scenarios become visible. We find that while single hadron observables such as R_AA are incapable of differentiating between the scenarios, jet observables such as the longiudinal momentum spectrum of hadrons in the jet show the potential to do so. |
0809.1927 | Matthias Steinhauser | Alexander V. Smirnov, Vladimir A. Smirnov, Matthias Steinhauser | Fermionic contributions to the three-loop static potential | 12 pages, 3 figures, to appear in Phys. Lett. B | Phys.Lett.B668:293-298,2008 | 10.1016/j.physletb.2008.08.070 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider the three-loop corrections to the static potential which are
induced by a closed fermion loop. For the reduction of the occurring integrals
a combination of the Gr\"obner and Laporta algorithm has been used and the
evaluation of the master integrals has been performed with the help of the
Mellin-Barnes technique. The fermionic three-loop corrections amount to 2% of
the tree-level result for top quarks, 8% for bottom quarks and 27% for the
charm quark system.
| [
{
"created": "Thu, 11 Sep 2008 08:20:48 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Smirnov",
"Alexander V.",
""
],
[
"Smirnov",
"Vladimir A.",
""
],
[
"Steinhauser",
"Matthias",
""
]
] | We consider the three-loop corrections to the static potential which are induced by a closed fermion loop. For the reduction of the occurring integrals a combination of the Gr\"obner and Laporta algorithm has been used and the evaluation of the master integrals has been performed with the help of the Mellin-Barnes technique. The fermionic three-loop corrections amount to 2% of the tree-level result for top quarks, 8% for bottom quarks and 27% for the charm quark system. |
2103.05269 | Sarka Todorova PhD | \v{S}\'arka Todorova-Nov\'a | Baryon production in the quantized fragmentation of helical QCD string | 11 pages, 7 figures | Phys. Rev. D 104, 034012 (2021) | 10.1103/PhysRevD.104.034012 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | Baryon production is studied within the framework of quantized fragmentation
of QCD string. Baryons appear in the model in a fairly intuitive way, with help
of causally connected string breakups. A simple helical approximation of QCD
flux tube with parameters constrained by mass spectrum of light mesons is
sufficient to reproduce masses of light baryons.
| [
{
"created": "Tue, 9 Mar 2021 07:32:47 GMT",
"version": "v1"
},
{
"created": "Thu, 10 Jun 2021 09:54:53 GMT",
"version": "v2"
}
] | 2021-08-25 | [
[
"Todorova-Nová",
"Šárka",
""
]
] | Baryon production is studied within the framework of quantized fragmentation of QCD string. Baryons appear in the model in a fairly intuitive way, with help of causally connected string breakups. A simple helical approximation of QCD flux tube with parameters constrained by mass spectrum of light mesons is sufficient to reproduce masses of light baryons. |
hep-ph/0102055 | Heui-Seol Roh | Heui-Seol Roh | Matter Mass Generation and Theta Vacuum: Dynamical Spontaneous Symmetry
Breaking | REVTEX, 5 pages | null | null | null | hep-ph nucl-th | null | This work proposes a stringent concept of matter mass generation and Theta
vacuum in the context of local gauge theory for the strong force under the
constraint of the flat universe. The matter mass is generated as the
consequence of dynamical spontaneous symmetry breaking (DSSB) of gauge symmetry
and discrete symmetries, which is motivated by the parameter Theta representing
the surface term. Matter mass generation introduces the typical features of
constituent particle mass, dual Meissner effect, and hyperfine structure. The
Theta term plays important roles on the DSSB of the gauge group and on the
quantization of the matter and vacuum space. The Theta vacuum exhibits the
intrinsic principal number and intrinsic angular momentum for intrinsic space
quantization in analogy with the extrinsic principal number and extrinsic
angular momentum for extrinsic space quantization.
| [
{
"created": "Tue, 6 Feb 2001 02:27:29 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Roh",
"Heui-Seol",
""
]
] | This work proposes a stringent concept of matter mass generation and Theta vacuum in the context of local gauge theory for the strong force under the constraint of the flat universe. The matter mass is generated as the consequence of dynamical spontaneous symmetry breaking (DSSB) of gauge symmetry and discrete symmetries, which is motivated by the parameter Theta representing the surface term. Matter mass generation introduces the typical features of constituent particle mass, dual Meissner effect, and hyperfine structure. The Theta term plays important roles on the DSSB of the gauge group and on the quantization of the matter and vacuum space. The Theta vacuum exhibits the intrinsic principal number and intrinsic angular momentum for intrinsic space quantization in analogy with the extrinsic principal number and extrinsic angular momentum for extrinsic space quantization. |
hep-ph/0007314 | Christer Friberg | Christer Friberg and Torbj\"orn Sj\"ostrand (Lund university, Sweden) | Total Cross Sections and Event Properties from Real to Virtual Photons | 1+34 pages, LaTeX2e, 24 eps figures, submitted to J. High Energy Phys | JHEP 0009:010,2000 | 10.1088/1126-6708/2000/09/010 | LU TP 00-29 | hep-ph | null | A model for total cross sections with virtual photons is presented. In
particular gamma*-p and gamma*-gamma* cross sections are considered. Our
approach extends on a model for photoproduction, where the total cross section
is subdivided into three distinct event classes: direct, VMD and anomalous.
With increasing photon virtuality, the latter two decrease in importance.
Instead Deep Inelastic Scattering dominates, with the direct class being the
O(alpha_s) correction thereof. Hence, the model provides a smooth transition
between the two regions. By the breakdown into different event classes, one may
aim for a complete picture of all event properties.
| [
{
"created": "Thu, 27 Jul 2000 15:47:02 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"Friberg",
"Christer",
"",
"Lund university, Sweden"
],
[
"Sjöstrand",
"Torbjörn",
"",
"Lund university, Sweden"
]
] | A model for total cross sections with virtual photons is presented. In particular gamma*-p and gamma*-gamma* cross sections are considered. Our approach extends on a model for photoproduction, where the total cross section is subdivided into three distinct event classes: direct, VMD and anomalous. With increasing photon virtuality, the latter two decrease in importance. Instead Deep Inelastic Scattering dominates, with the direct class being the O(alpha_s) correction thereof. Hence, the model provides a smooth transition between the two regions. By the breakdown into different event classes, one may aim for a complete picture of all event properties. |
1108.4512 | Wei-Min Yang | Wei-Min Yang, Qi Wang, Jin-Jin Zhong | A Model of Fermion Masses and Flavor Mixings with Family Symmetry
$SU(3)\otimes U(1)$ | 14 pages, 1 figure, to make a few of corrections to the old version.
arXiv admin note: substantial text overlap with arXiv:1011.4573 | Commun.Theor.Phys. 57 (2012) 71-77 | 10.1088/0253-6102/57/1/12 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The family symmetry $SU(3)\otimes U(1)$ is proposed to solve flavor problems
about fermion masses and flavor mixings. It's breaking is implemented by some
flavon fields at the high-energy scale. In addition a discrete group $Z_{2}$ is
introduced to generate tiny neutrino masses, which is broken by a real singlet
scalar field at the middle-energy scale. The low-energy effective theory is
elegantly obtained after all of super-heavy fermions are integrated out and
decoupling. All the fermion mass matrices are regularly characterized by four
fundamental matrices and thirteen parameters. The model can perfectly fit and
account for all the current experimental data about the fermion masses and
flavor mixings, in particular, it finely predicts the first generation quark
masses and the values of $\theta^{\,l}_{13}$ and $J_{CP}^{\,l}$ in neutrino
physics. All of the results are promising to be tested in the future
experiments.
| [
{
"created": "Tue, 23 Aug 2011 07:43:24 GMT",
"version": "v1"
},
{
"created": "Thu, 20 Oct 2011 09:23:07 GMT",
"version": "v2"
}
] | 2015-05-30 | [
[
"Yang",
"Wei-Min",
""
],
[
"Wang",
"Qi",
""
],
[
"Zhong",
"Jin-Jin",
""
]
] | The family symmetry $SU(3)\otimes U(1)$ is proposed to solve flavor problems about fermion masses and flavor mixings. It's breaking is implemented by some flavon fields at the high-energy scale. In addition a discrete group $Z_{2}$ is introduced to generate tiny neutrino masses, which is broken by a real singlet scalar field at the middle-energy scale. The low-energy effective theory is elegantly obtained after all of super-heavy fermions are integrated out and decoupling. All the fermion mass matrices are regularly characterized by four fundamental matrices and thirteen parameters. The model can perfectly fit and account for all the current experimental data about the fermion masses and flavor mixings, in particular, it finely predicts the first generation quark masses and the values of $\theta^{\,l}_{13}$ and $J_{CP}^{\,l}$ in neutrino physics. All of the results are promising to be tested in the future experiments. |
0711.1077 | Markus Diehl | Markus Diehl | Implications of HERA measurements for LHC | 11 pages, talk presented at the XXIII International Symposium on
Lepton and Photon Interactions at High Energy (LP07). v2: references added | null | null | DESY 07-194 | hep-ph | null | I discuss the theoretical understanding of key measurements at HERA and their
relevance for physics at LHC, focusing on recent developments for structure
functions and for diffraction.
| [
{
"created": "Wed, 7 Nov 2007 13:01:44 GMT",
"version": "v1"
},
{
"created": "Fri, 9 Nov 2007 12:13:41 GMT",
"version": "v2"
}
] | 2011-11-10 | [
[
"Diehl",
"Markus",
""
]
] | I discuss the theoretical understanding of key measurements at HERA and their relevance for physics at LHC, focusing on recent developments for structure functions and for diffraction. |
1712.06384 | Hrayr Matevosyan | Hrayr H. Matevosyan, Aram Kotzinian, Anthony W. Thomas | Accessing Quark Helicity through Dihadron Studies | 5 pages, 1 figure. V3: Updated to version published in PRL with minor
revisions of the text and an added reference | Phys. Rev. Lett. 120, 252001 (2018) | 10.1103/PhysRevLett.120.252001 | ADP-17-42/T1048 | hep-ph hep-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a new proposal to study the helicity-dependent dihadron
fragmentation functions (DiFF), which describe the correlations of the
longitudinal polarization of a fragmenting quark with the transverse momenta of
the produced hadron pair. Recent experimental searches for this DiFF via
azimuthal asymmetries in back-to-back hadron pair production in $e^+e^-$
annihilation by the ${\tt BELLE}$ Collaboration did not yield a signal. Here we
propose a new way to access this DiFF in $e^+e^-$ annihilation, motivated by
the recently recalculated cross section of this reaction, which explains why
there was in fact no signal for the ${\tt BELLE}$ Collaboration to see. In this
new approach the azimuthal asymmetry is weighted by the virtual photon's
transverse momentum square multiplying sine and cosine functions of difference
of azimuthal angles of relative and total momentum for each pair. The
integration over the virtual photon's transverse momentum has the effect of
separating the convolution between the helicity-dependent DiFFs in the quark
and antiquark jets and results in a nonzero collinear expression containing
Fourier moments of helicity-dependent DiFFs. A second new measurement is also
proposed for two-hadron production in semi-inclusive deep inelastic scattering,
where the asymmetry is weighted in a similar way for a single pair. This
results in a collinear factorized form of the asymmetry, which includes the
quark helicity parton distribution function and the same helicity-dependent
DiFF as in $e^+e^-$ production and will allow us to check the universality of
this DiFF.
| [
{
"created": "Mon, 18 Dec 2017 13:26:15 GMT",
"version": "v1"
},
{
"created": "Mon, 25 Dec 2017 13:17:59 GMT",
"version": "v2"
},
{
"created": "Tue, 10 Jul 2018 18:00:00 GMT",
"version": "v3"
}
] | 2018-07-12 | [
[
"Matevosyan",
"Hrayr H.",
""
],
[
"Kotzinian",
"Aram",
""
],
[
"Thomas",
"Anthony W.",
""
]
] | We present a new proposal to study the helicity-dependent dihadron fragmentation functions (DiFF), which describe the correlations of the longitudinal polarization of a fragmenting quark with the transverse momenta of the produced hadron pair. Recent experimental searches for this DiFF via azimuthal asymmetries in back-to-back hadron pair production in $e^+e^-$ annihilation by the ${\tt BELLE}$ Collaboration did not yield a signal. Here we propose a new way to access this DiFF in $e^+e^-$ annihilation, motivated by the recently recalculated cross section of this reaction, which explains why there was in fact no signal for the ${\tt BELLE}$ Collaboration to see. In this new approach the azimuthal asymmetry is weighted by the virtual photon's transverse momentum square multiplying sine and cosine functions of difference of azimuthal angles of relative and total momentum for each pair. The integration over the virtual photon's transverse momentum has the effect of separating the convolution between the helicity-dependent DiFFs in the quark and antiquark jets and results in a nonzero collinear expression containing Fourier moments of helicity-dependent DiFFs. A second new measurement is also proposed for two-hadron production in semi-inclusive deep inelastic scattering, where the asymmetry is weighted in a similar way for a single pair. This results in a collinear factorized form of the asymmetry, which includes the quark helicity parton distribution function and the same helicity-dependent DiFF as in $e^+e^-$ production and will allow us to check the universality of this DiFF. |
2106.05192 | Muslem Rahimi | Marzia Bordone, Muslem Rahimi, K. Keri Vos | Lepton flavour violation in rare $\Lambda_b$ decays | 26 pages, 4 figures; v3 is conformal with published version | Eur.Phys.J.C (2021) 81 | 10.1140/epjc/s10052-021-09531-9 | P3H-21-039, SI-HEP-2021-17, Nikhef-2021-012 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Lepton flavour violation (LFV) naturally occurs in many new physics models,
specifically in those explaining the $B$ anomalies. While LFV has already been
studied for mesonic decays, it is important to consider also baryonic decays
mediated by the same quark transition. In this paper, we study LFV in the
baryonic $\Lambda_b \to \Lambda \ell_1 \ell_2$ using for the first time a full
basis of New Physics operators. We present expected bounds on the branching
ratio in a model-independent framework and using two specific new physics
models. Finally, we point out the interplay and orthogonality between the
baryonic and mesonic LFV searches.
| [
{
"created": "Wed, 9 Jun 2021 16:32:07 GMT",
"version": "v1"
},
{
"created": "Tue, 22 Jun 2021 09:51:05 GMT",
"version": "v2"
},
{
"created": "Thu, 26 Aug 2021 14:38:13 GMT",
"version": "v3"
}
] | 2021-09-15 | [
[
"Bordone",
"Marzia",
""
],
[
"Rahimi",
"Muslem",
""
],
[
"Vos",
"K. Keri",
""
]
] | Lepton flavour violation (LFV) naturally occurs in many new physics models, specifically in those explaining the $B$ anomalies. While LFV has already been studied for mesonic decays, it is important to consider also baryonic decays mediated by the same quark transition. In this paper, we study LFV in the baryonic $\Lambda_b \to \Lambda \ell_1 \ell_2$ using for the first time a full basis of New Physics operators. We present expected bounds on the branching ratio in a model-independent framework and using two specific new physics models. Finally, we point out the interplay and orthogonality between the baryonic and mesonic LFV searches. |
0907.5603 | Maurice Benayoun | M. Benayoun, P. David, L. DelBuono, O. Leitner | A Global Treatment Of VMD Physics Up To The phi: II. tau Decay and
Hadronic Contributions To g-2 | 43 pages, scope enlarged, model extended, same conclusions. Accepted
for publication in EPJ-C | Eur.Phys.J.C68:355-379,2010 | 10.1140/epjc/s10052-010-1389-0 | LPNHE 2009-006 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Relying on the Hidden Local Symmetry (HLS) model equipped with a mechanism
breaking the U(3)/SU(3)/SU(2) symmetries and generating a dynamical vector
meson mixing, it has been shown that a global fit successfully describes the
cross sections for the e+ e- -> pi+ pi-, e+ e- -> (pi0/eta) gamma and e+ e- ->
pi0 pi+ pi- annihilation channels. One extends this global fit in order to
include also the dipion spectra from the tau decay, taking into account all
reported information on their statistical and systematic errors. A model
accounting for lineshape distortions of the rho+- spectrum relative to rho0 is
also examined when analyzing the tau data behavior within the global fit
framework. One shows that a successful account for e+ e- annihilation data and
tau spectra can be simultaneously reached. Then, issues related with
non--perturbative hadronic contributions to the muon g-2 are examined in
details. It is shown that all e+ e- data considered together allow for improved
and motivated estimates for the a_mu(pi+ pi-), the pi+ pi- loop contribution to
the muon g-2; for instance, integrated between 0.630 and 0.958 GeV, we find
a_mu(pi+ pi-)= 359.62 +- 1.62 (in units of 10^{-10}), a 40% improvement of the
current uncertainty. The effects of the various tau samples in the context of a
global fit procedure leads to conclude that different lineshape distortions are
revealed by the ALEPH, BELLE and CLEO data samples. Relying on global fits to
the data quoted above, one also provides motivated estimates of the pi+ pi-,
pi0 gamma, eta gamma and pi0 pi+ pi- contributions to a_mu up to 1 GeV with the
smallest possible uncertainties. These estimates are based on various global
fit configurations, each yielding a good probability.
| [
{
"created": "Fri, 31 Jul 2009 19:53:20 GMT",
"version": "v1"
},
{
"created": "Wed, 5 Aug 2009 12:24:13 GMT",
"version": "v2"
},
{
"created": "Fri, 25 Jun 2010 11:08:58 GMT",
"version": "v3"
}
] | 2014-11-20 | [
[
"Benayoun",
"M.",
""
],
[
"David",
"P.",
""
],
[
"DelBuono",
"L.",
""
],
[
"Leitner",
"O.",
""
]
] | Relying on the Hidden Local Symmetry (HLS) model equipped with a mechanism breaking the U(3)/SU(3)/SU(2) symmetries and generating a dynamical vector meson mixing, it has been shown that a global fit successfully describes the cross sections for the e+ e- -> pi+ pi-, e+ e- -> (pi0/eta) gamma and e+ e- -> pi0 pi+ pi- annihilation channels. One extends this global fit in order to include also the dipion spectra from the tau decay, taking into account all reported information on their statistical and systematic errors. A model accounting for lineshape distortions of the rho+- spectrum relative to rho0 is also examined when analyzing the tau data behavior within the global fit framework. One shows that a successful account for e+ e- annihilation data and tau spectra can be simultaneously reached. Then, issues related with non--perturbative hadronic contributions to the muon g-2 are examined in details. It is shown that all e+ e- data considered together allow for improved and motivated estimates for the a_mu(pi+ pi-), the pi+ pi- loop contribution to the muon g-2; for instance, integrated between 0.630 and 0.958 GeV, we find a_mu(pi+ pi-)= 359.62 +- 1.62 (in units of 10^{-10}), a 40% improvement of the current uncertainty. The effects of the various tau samples in the context of a global fit procedure leads to conclude that different lineshape distortions are revealed by the ALEPH, BELLE and CLEO data samples. Relying on global fits to the data quoted above, one also provides motivated estimates of the pi+ pi-, pi0 gamma, eta gamma and pi0 pi+ pi- contributions to a_mu up to 1 GeV with the smallest possible uncertainties. These estimates are based on various global fit configurations, each yielding a good probability. |
0804.4025 | Duc Ninh Le | Le Duc Ninh | Yukawa corrections to Higgs production associated with two bottom quarks
at the LHC | 3 pages, 3 figures, to appear in the proceedings of 43rd Rencontres
de Moriond EW, La Thuile, Italy, 1-8 March 2008 | null | null | LAPTH-Conf-1248/08 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the leading one-loop Yukawa corrections to the process pp-> b
anti-b H in the Standard Model. We find that the next-to-leading order
correction to the cross section is small about -4% if the Higgs mass is 120GeV.
However, the appearance of leading Landau singularity when $M_H > 2M_W$ can
lead to a large correction at the next-to-next-to-leading order level for a
Higgs mass around 160GeV.
| [
{
"created": "Thu, 24 Apr 2008 22:21:43 GMT",
"version": "v1"
}
] | 2008-04-28 | [
[
"Ninh",
"Le Duc",
""
]
] | We investigate the leading one-loop Yukawa corrections to the process pp-> b anti-b H in the Standard Model. We find that the next-to-leading order correction to the cross section is small about -4% if the Higgs mass is 120GeV. However, the appearance of leading Landau singularity when $M_H > 2M_W$ can lead to a large correction at the next-to-next-to-leading order level for a Higgs mass around 160GeV. |
1809.05362 | Grzegorz Wilk | M. Rybczy\'nski, G. Wilk and Z. W{\l}odarczyk | Intriguing feature of multiplicity distributions | Invited talk presented at XLVIII International Symposium on
Multiparticle Dynamics (ISMD2018), 3 to 7 September 2018, Singapore; 10
pages, 6 figures. To be published in EPJ Web of Conferences | EPJ Web of Conf. 206, 03002 (2019) | 10.1051/epjconf/201920603002 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Multiplicity distributions, P(N), provide valuable information on the
mechanism of the production process. We argue that the observed P(N) contain
more information (located in the small N region) than expected and used so far.
We demonstrate that it can be retrieved by analysing specific combinations of
the experimentally measured values of P(N) which we call {it modified
combinants, Cj, and which show distinct oscillatory behavior, not observed in
the usual phenomenological forms of the P(N) used to fit data. We discuss the
possible sources of these oscillations and their impact on our understanding of
the multiparticle production mechanism.
| [
{
"created": "Fri, 14 Sep 2018 11:37:02 GMT",
"version": "v1"
}
] | 2019-06-06 | [
[
"Rybczyński",
"M.",
""
],
[
"Wilk",
"G.",
""
],
[
"Włodarczyk",
"Z.",
""
]
] | Multiplicity distributions, P(N), provide valuable information on the mechanism of the production process. We argue that the observed P(N) contain more information (located in the small N region) than expected and used so far. We demonstrate that it can be retrieved by analysing specific combinations of the experimentally measured values of P(N) which we call {it modified combinants, Cj, and which show distinct oscillatory behavior, not observed in the usual phenomenological forms of the P(N) used to fit data. We discuss the possible sources of these oscillations and their impact on our understanding of the multiparticle production mechanism. |
1310.5157 | Simonetta Liuti | Aurore Courtoy, Gary R. Goldstein, J. Osvaldo Gonzalez Hernandez,
Simonetta Liuti and Abha Rajan | On the Observability of the Quark Orbital Angular Momentum Distribution | 10 pages, 3 figures; version published in Physics Letters B | null | 10.1016/j.physletb.2014.02.017 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We argue that due to Parity constraints, the helicity combination of the
purely momentum space counterparts of the Wigner distributions -- the
generalized transverse momentum distributions -- that describes the
configuration of an unpolarized quark in a longitudinally polarized nucleon,
can enter the deeply virtual Compton scattering amplitude only through matrix
elements involving a final state interaction. The relevant matrix elements in
turn involve light cone operators projections in the transverse direction, or
they appear in the deeply virtual Compton scattering amplitude at twist three.
Orbital angular momentum or the spin structure of the nucleon was a major
reason for these various distributions and amplitudes to have been introduced.
We show that the twist three contributions associated to orbital angular
momentum %to deeply virtual Compton scattering provide observables related to
orbital angular momentum and are related to the target-spin asymmetry in deeply
virtual Compton scattering, already measured at HERMES.
| [
{
"created": "Fri, 18 Oct 2013 20:21:11 GMT",
"version": "v1"
},
{
"created": "Tue, 18 Mar 2014 14:25:56 GMT",
"version": "v2"
}
] | 2015-06-17 | [
[
"Courtoy",
"Aurore",
""
],
[
"Goldstein",
"Gary R.",
""
],
[
"Hernandez",
"J. Osvaldo Gonzalez",
""
],
[
"Liuti",
"Simonetta",
""
],
[
"Rajan",
"Abha",
""
]
] | We argue that due to Parity constraints, the helicity combination of the purely momentum space counterparts of the Wigner distributions -- the generalized transverse momentum distributions -- that describes the configuration of an unpolarized quark in a longitudinally polarized nucleon, can enter the deeply virtual Compton scattering amplitude only through matrix elements involving a final state interaction. The relevant matrix elements in turn involve light cone operators projections in the transverse direction, or they appear in the deeply virtual Compton scattering amplitude at twist three. Orbital angular momentum or the spin structure of the nucleon was a major reason for these various distributions and amplitudes to have been introduced. We show that the twist three contributions associated to orbital angular momentum %to deeply virtual Compton scattering provide observables related to orbital angular momentum and are related to the target-spin asymmetry in deeply virtual Compton scattering, already measured at HERMES. |
2105.09277 | Aris Spourdalakis | Matthew Inglis-Whalen, Michael Luke, Jyotirmoy Roy and Aris
Spourdalakis | Factorization of Power Corrections in the Drell-Yan Process in EFT | 29 pages, 1 figure, v2: minor edits, journal version | Phys. Rev. D 104, 076018 (2021) | 10.1103/PhysRevD.104.076018 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We examine the quark-induced Drell-Yan process at next-to-leading power (NLP)
in Soft-Collinear Effective Theory. Using an approach with no explicit soft or
collinear modes, we discuss the factorization of the differential cross section
in the small-$q_T$ hierarchy with $q^2\gg q_T^2\gg\Lambda_{\mathrm{QCD}}^2$. We
show that the cross section may be written in terms of matrix elements of
power-suppressed operators $T_{(i,j)}$, which contribute to $O(q_T^2/q^2)$
coefficients of the usual parton distribution functions. We derive a
factorization for this observable at NLP which allows the large logarithms in
each of the relevant factors to be resummed. We discuss the cancellation of
rapidity divergences and the overlap subtractions required to eliminate double
counting at next-to-leading power.
| [
{
"created": "Wed, 19 May 2021 17:41:31 GMT",
"version": "v1"
},
{
"created": "Wed, 20 Oct 2021 18:27:04 GMT",
"version": "v2"
}
] | 2021-10-22 | [
[
"Inglis-Whalen",
"Matthew",
""
],
[
"Luke",
"Michael",
""
],
[
"Roy",
"Jyotirmoy",
""
],
[
"Spourdalakis",
"Aris",
""
]
] | We examine the quark-induced Drell-Yan process at next-to-leading power (NLP) in Soft-Collinear Effective Theory. Using an approach with no explicit soft or collinear modes, we discuss the factorization of the differential cross section in the small-$q_T$ hierarchy with $q^2\gg q_T^2\gg\Lambda_{\mathrm{QCD}}^2$. We show that the cross section may be written in terms of matrix elements of power-suppressed operators $T_{(i,j)}$, which contribute to $O(q_T^2/q^2)$ coefficients of the usual parton distribution functions. We derive a factorization for this observable at NLP which allows the large logarithms in each of the relevant factors to be resummed. We discuss the cancellation of rapidity divergences and the overlap subtractions required to eliminate double counting at next-to-leading power. |
hep-ph/9504216 | Steve Godfrey | M. Cvetic and S. Godfrey | Discovery and Identification of Extra Gauge Bosons | 34 pages, Latex file using equations.sty and psfig.sty, 6 postcript
figures (uuencoded) added with figures command. Full postcript version,
complete with embedded figures is available at
ftp://ftp.physics.carleton.ca/pub/theory/godfrey/ocip9502.ps . Summary of the
Working Subgroup on Extra Gauge Bosons of the DPF Long-Range Planning Study,
to be published in "Electroweak Symmetry Breaking and Beyond the Standard
Model", eds T. Barklow, S. Dawson, H. Haber, and J. Seigrist | null | 10.1142/9789812830265_0007 | OCIP/C-95-2, UPR-648-T | hep-ph | null | The discovery potential and diagnostic abilities of proposed future colliders
for new heavy neutral ($Z'$) and charged ($W'$) gauge bosons are summarized.
Typical bounds achievable on $M_{Z',W'}$ at the TEVATRON, DI-TEVATRON, LHC, 500
GeV NLC, and 1 TeV NLC are $\sim$1~TeV, $\sim$2~TeV, $\sim$4~TeV, 1--3~TeV, and
2--6~TeV, respectively. For $M_{Z'} \sim$1 TeV the LHC will have the capability
to determine the magnitude of normalized $Z'$ quark and lepton couplings to
around $10-20\%$, while the NLC would allow for determination of the couplings
(including their signs) with a factor of 2 larger error-bars, provided heavy
flavor tagging and longitudinal polarization of the electron beam is available.
| [
{
"created": "Tue, 4 Apr 1995 14:36:13 GMT",
"version": "v1"
}
] | 2016-11-03 | [
[
"Cvetic",
"M.",
""
],
[
"Godfrey",
"S.",
""
]
] | The discovery potential and diagnostic abilities of proposed future colliders for new heavy neutral ($Z'$) and charged ($W'$) gauge bosons are summarized. Typical bounds achievable on $M_{Z',W'}$ at the TEVATRON, DI-TEVATRON, LHC, 500 GeV NLC, and 1 TeV NLC are $\sim$1~TeV, $\sim$2~TeV, $\sim$4~TeV, 1--3~TeV, and 2--6~TeV, respectively. For $M_{Z'} \sim$1 TeV the LHC will have the capability to determine the magnitude of normalized $Z'$ quark and lepton couplings to around $10-20\%$, while the NLC would allow for determination of the couplings (including their signs) with a factor of 2 larger error-bars, provided heavy flavor tagging and longitudinal polarization of the electron beam is available. |
hep-ph/0304059 | Igor Shovkovy | V. P. Gusynin, V. A. Miransky and I. A. Shovkovy | Large N dynamics in QED in a magnetic field | 4 pages, REVTeX | Phys.Rev. D67 (2003) 107703 | 10.1103/PhysRevD.67.107703 | null | hep-ph | null | The expression for the dynamical mass of fermions in QED in a magnetic field
is obtained for a large number of the fermion flavor N in the framework of 1/N
expansion. The existence of a threshold value N_{thr}, dividing the theories
with essentially different dynamics, is established. For the number of flavors
N << N_{thr}, the dynamical mass is very sensitive to the value of the coupling
constant \alpha_b, related to the magnetic scale \mu = |eB|. For N of order
N_{thr} or larger, a dynamics similar to that in the Nambu-Jona-Lasinio model
with cutoff of order |eB| and the dimensional coupling constant G \sim
1/(N|eB|) takes place. In this case, the value of the dynamical mass is
essentially \alpha_b independent (the dynamics with an infrared stable fixed
point). The value of N_{thr} separates a weak coupling dynamics (with
\tilde{\alpha}_b \equiv N\alpha_b << 1) from a strong coupling one (with
\tilde{\alpha}_b \gtrsim 1) and is of order 1/\alpha_b.
| [
{
"created": "Sun, 6 Apr 2003 16:30:55 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Gusynin",
"V. P.",
""
],
[
"Miransky",
"V. A.",
""
],
[
"Shovkovy",
"I. A.",
""
]
] | The expression for the dynamical mass of fermions in QED in a magnetic field is obtained for a large number of the fermion flavor N in the framework of 1/N expansion. The existence of a threshold value N_{thr}, dividing the theories with essentially different dynamics, is established. For the number of flavors N << N_{thr}, the dynamical mass is very sensitive to the value of the coupling constant \alpha_b, related to the magnetic scale \mu = |eB|. For N of order N_{thr} or larger, a dynamics similar to that in the Nambu-Jona-Lasinio model with cutoff of order |eB| and the dimensional coupling constant G \sim 1/(N|eB|) takes place. In this case, the value of the dynamical mass is essentially \alpha_b independent (the dynamics with an infrared stable fixed point). The value of N_{thr} separates a weak coupling dynamics (with \tilde{\alpha}_b \equiv N\alpha_b << 1) from a strong coupling one (with \tilde{\alpha}_b \gtrsim 1) and is of order 1/\alpha_b. |
hep-ph/0501220 | Ulrich Jentschura | U. D. Jentschura and J. Evers | Some Recent Advances in Bound-State Quantum Electrodynamics | 12 pages, nrc1 LaTeX style | Can.J.Phys.83:375-386,2005 | 10.1139/p05-018 | null | hep-ph | null | We discuss recent progress in various problems related to bound-state quantum
electrodynamics: the bound-electron g factor, two-loop self-energy corrections
and the laser-dressed Lamb shift. The progress relies on various advances in
the bound-state formalism, including ideas inspired by effective field theories
such as Nonrelativistic Quantum Electrodynamics. Radiative corrections in
dynamical processes represent a promising field for further investigations.
| [
{
"created": "Mon, 24 Jan 2005 17:56:44 GMT",
"version": "v1"
}
] | 2011-08-17 | [
[
"Jentschura",
"U. D.",
""
],
[
"Evers",
"J.",
""
]
] | We discuss recent progress in various problems related to bound-state quantum electrodynamics: the bound-electron g factor, two-loop self-energy corrections and the laser-dressed Lamb shift. The progress relies on various advances in the bound-state formalism, including ideas inspired by effective field theories such as Nonrelativistic Quantum Electrodynamics. Radiative corrections in dynamical processes represent a promising field for further investigations. |
1505.03595 | Ernany Rossi Schmitz | B. L. S\'anchez-Vega and E. R. Schmitz | Fermionic dark matter and neutrino masses in a $\mathcal{B-L}$ model | 29 pages, 5 figures | Phys. Rev. D 92, 053007 (2015) | 10.1103/PhysRevD.92.053007 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this work we present a common framework for neutrino mass and dark matter.
Specifically, we work with a local $\mathcal{B-L}$ extension of the standard
model which has three right-handed neutrinos, $n_{R_{i}}$, and some extra
scalars, $\Phi$, $\phi_{i}$ besides the standard model fields. The
$n_{R_{i}}$'s have non-standard $\mathcal{B-L}$ quantum numbers and thus these
couple to different scalars. This model has the attractive property that an
almost automatic $Z_2$ symmetry acting only on a fermionic field, $n_{R3}$, is
present. Taking advantage of this $Z_2$ symmetry, we study both the neutrino
mass generation via a natural see-saw mechanism in low energy and the
possibility of $n_{R3}$ to be a DM candidate. For this last purpose, we study
its relic abundance and its compatibility with the current direct detection
experiments.
| [
{
"created": "Thu, 14 May 2015 01:51:32 GMT",
"version": "v1"
}
] | 2015-09-23 | [
[
"Sánchez-Vega",
"B. L.",
""
],
[
"Schmitz",
"E. R.",
""
]
] | In this work we present a common framework for neutrino mass and dark matter. Specifically, we work with a local $\mathcal{B-L}$ extension of the standard model which has three right-handed neutrinos, $n_{R_{i}}$, and some extra scalars, $\Phi$, $\phi_{i}$ besides the standard model fields. The $n_{R_{i}}$'s have non-standard $\mathcal{B-L}$ quantum numbers and thus these couple to different scalars. This model has the attractive property that an almost automatic $Z_2$ symmetry acting only on a fermionic field, $n_{R3}$, is present. Taking advantage of this $Z_2$ symmetry, we study both the neutrino mass generation via a natural see-saw mechanism in low energy and the possibility of $n_{R3}$ to be a DM candidate. For this last purpose, we study its relic abundance and its compatibility with the current direct detection experiments. |
hep-ph/0701266 | V\'eronique Pag\'e | Veronique Page | Non-thermal right-handed sneutrino dark matter and the Omega_DM/Omega_b
problem | 11 pages, 2 figures, 2 typos added, 1 reference added, minor
corrections in section 3 | JHEP 0704:021,2007 | 10.1088/1126-6708/2007/04/021 | null | hep-ph | null | We argue that the superpartner of the Dirac right-handed neutrino is a prime
candidate for dark matter created from a 'mattergenesis' mechanism. We show
that due to the smallness of the Yukawa couplings, a right-handed sneutrino
density created in the early Universe would not be erased by annihilations,
which remain out of thermal equilibrium. It would also not be drowned by a
later, additional production of right-handed sneutrinos, as the relic density
of the non-thermal right-handed sneutrinos is found to be generally negligible
compared to the observed dark matter density. Mild constraints on sneutrino
masses and trilinear SUSY-breaking couplings are obtained. Possible
mattergenesis scenarios are also mentioned
| [
{
"created": "Wed, 31 Jan 2007 10:42:15 GMT",
"version": "v1"
},
{
"created": "Fri, 2 Feb 2007 14:49:28 GMT",
"version": "v2"
},
{
"created": "Mon, 5 Feb 2007 17:41:15 GMT",
"version": "v3"
},
{
"created": "Tue, 3 Apr 2007 14:17:49 GMT",
"version": "v4"
}
] | 2010-10-27 | [
[
"Page",
"Veronique",
""
]
] | We argue that the superpartner of the Dirac right-handed neutrino is a prime candidate for dark matter created from a 'mattergenesis' mechanism. We show that due to the smallness of the Yukawa couplings, a right-handed sneutrino density created in the early Universe would not be erased by annihilations, which remain out of thermal equilibrium. It would also not be drowned by a later, additional production of right-handed sneutrinos, as the relic density of the non-thermal right-handed sneutrinos is found to be generally negligible compared to the observed dark matter density. Mild constraints on sneutrino masses and trilinear SUSY-breaking couplings are obtained. Possible mattergenesis scenarios are also mentioned |
hep-ph/0307126 | Xiong Zhaohua | Junjie Cao, Zhaohua Xiong, Jin Min Yang | Lepton flavor violating Z-decays in supersymmetric see-saw model | 8 pages,4 ps files, to appear in EPJC | Eur.Phys.J. C32 (2004) 245-252 | 10.1140/epjc/s2003-01391-1 | null | hep-ph | null | In supersymmetric see-saw model, the large flavor mixings of sleptons induce
the lepton flavor violating (LFV) interactions $\ell_I \bar\ell_J V$
($V=\gamma, Z$), which give rise to various LFV processes. In this work we
examine the induced LFV decays $Z\to\ell_I \bar\ell_J$. Subject to the
constraints from the existing neutrino oscillation data and the experimental
bounds on the decays $\ell_J\to\ell_I\gamma$, these LFV $Z$-decays are found to
be sizable, among which the largest-rate channel $Z\to \tau \bar{\mu}$ can
ocuur with a branching ratio of $10^{-8}$ and may be accessible at the LHC or
GiagZ experiment.
| [
{
"created": "Wed, 9 Jul 2003 06:11:38 GMT",
"version": "v1"
},
{
"created": "Mon, 6 Oct 2003 09:44:14 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Cao",
"Junjie",
""
],
[
"Xiong",
"Zhaohua",
""
],
[
"Yang",
"Jin Min",
""
]
] | In supersymmetric see-saw model, the large flavor mixings of sleptons induce the lepton flavor violating (LFV) interactions $\ell_I \bar\ell_J V$ ($V=\gamma, Z$), which give rise to various LFV processes. In this work we examine the induced LFV decays $Z\to\ell_I \bar\ell_J$. Subject to the constraints from the existing neutrino oscillation data and the experimental bounds on the decays $\ell_J\to\ell_I\gamma$, these LFV $Z$-decays are found to be sizable, among which the largest-rate channel $Z\to \tau \bar{\mu}$ can ocuur with a branching ratio of $10^{-8}$ and may be accessible at the LHC or GiagZ experiment. |
2405.08494 | Cheng Li | Cheng Li and Gudrid Moortgat-Pick | Determination of CP-violating $HZZ$ interaction with polarised beams at
the ILC | V2: Adding the references and correcting the definition of effective
CP-odd fraction $f_{cp}$ | null | null | DESY-24-068 | hep-ph | http://creativecommons.org/licenses/by-nc-sa/4.0/ | We study possible CP-violation effects of the 125 GeV Higgs to $Z$ boson
coupling at the 250 GeV ILC with transverse and longitudinal beam polarisation
via the process $e^+ e^- \rightarrow HZ \rightarrow H \mu^-\mu^+$. We explore
the azimuthal angular distribution of the muon pair from the $Z$ boson decay,
and constructe CP-odd observables sensitive to CP-violation effects, where we
derived this observable both by analytical calculations and by
$\mathtt{Whizard}$ simulations. Particularly, we can construct two CP-odd
observables with the help of transversely-polarised initial beams and improve
the statistical significance of CP-violation effects by combining two
measurements. We defined the asymmetries between the signal regions with
different signs of the CP-odd observables, and determine the CP-violation
effect by comparing with the SM 95% C.L. upper bound. In this paper, we setup a
scenario which assumes that the total cross-section is always fixed while
CP-violation is varying, and such a scenario helps us to determine the
intrinsic CP-mixing angle limit around $|\xi_{CP}|\sim 0.03$ with (90%, 40%)
polarised electron-positron beams and 5 ab$^{-1}$ integrated luminosity. In
addition, we determine the CP-odd coupling limit $|\widetilde{c}_{HZZ}|\sim
0.01$ as well, where we suppose that the SM tree-level cross-section is fixed
and the CP-violation is the varying additional contribution. Comparing with the
analysis with unpolarised beams, the sensitivity to the CP-violation effect can
be improved by transverse or longitudinal polarisation.
| [
{
"created": "Tue, 14 May 2024 10:39:37 GMT",
"version": "v1"
},
{
"created": "Tue, 28 May 2024 01:53:15 GMT",
"version": "v2"
}
] | 2024-05-29 | [
[
"Li",
"Cheng",
""
],
[
"Moortgat-Pick",
"Gudrid",
""
]
] | We study possible CP-violation effects of the 125 GeV Higgs to $Z$ boson coupling at the 250 GeV ILC with transverse and longitudinal beam polarisation via the process $e^+ e^- \rightarrow HZ \rightarrow H \mu^-\mu^+$. We explore the azimuthal angular distribution of the muon pair from the $Z$ boson decay, and constructe CP-odd observables sensitive to CP-violation effects, where we derived this observable both by analytical calculations and by $\mathtt{Whizard}$ simulations. Particularly, we can construct two CP-odd observables with the help of transversely-polarised initial beams and improve the statistical significance of CP-violation effects by combining two measurements. We defined the asymmetries between the signal regions with different signs of the CP-odd observables, and determine the CP-violation effect by comparing with the SM 95% C.L. upper bound. In this paper, we setup a scenario which assumes that the total cross-section is always fixed while CP-violation is varying, and such a scenario helps us to determine the intrinsic CP-mixing angle limit around $|\xi_{CP}|\sim 0.03$ with (90%, 40%) polarised electron-positron beams and 5 ab$^{-1}$ integrated luminosity. In addition, we determine the CP-odd coupling limit $|\widetilde{c}_{HZZ}|\sim 0.01$ as well, where we suppose that the SM tree-level cross-section is fixed and the CP-violation is the varying additional contribution. Comparing with the analysis with unpolarised beams, the sensitivity to the CP-violation effect can be improved by transverse or longitudinal polarisation. |
1511.08787 | Gilly Elor | Gilly Elor, Nicholas L. Rodd, Tracy R. Slatyer, and Wei Xue | Model-Independent Indirect Detection Constraints on Hidden Sector Dark
Matter | Published version. Added analysis on interplay between indirect
detection bounds and the Galactic Center GeV excess. Added antiproton ratio
bounds | JCAP 1606 (2016) no.06, 024 | 10.1088/1475-7516/2016/06/024 | MIT-CTP/4742 | hep-ph astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | If dark matter inhabits an expanded "hidden sector", annihilations may
proceed through sequential decays or multi-body final states. We map out the
potential signals and current constraints on such a framework in indirect
searches, using a model-independent setup based on multi-step hierarchical
cascade decays. While remaining agnostic to the details of the hidden sector
model, our framework captures the generic broadening of the spectrum of
secondary particles (photons, neutrinos, e+e- and antiprotons) relative to the
case of direct annihilation to Standard Model particles. We explore how
indirect constraints on dark matter annihilation limit the parameter space for
such cascade/multi-particle decays. We investigate limits from the cosmic
microwave background by Planck, the Fermi measurement of photons from the dwarf
galaxies, and positron data from AMS-02. The presence of a hidden sector can
change the constraints on the dark matter annihilation cross section by up to
an order of magnitude in either direction (although the effect can be much
smaller). We find that generally the bound from the Fermi dwarfs is most
constraining for annihilations to photon-rich final states, while AMS-02 is
most constraining for electron and muon final states; however in certain
instances the CMB bounds overtake both, due to their approximate independence
of the details of the hidden sector cascade. We provide the full set of cascade
spectra considered here as publicly available code with examples at
http://web.mit.edu/lns/research/CascadeSpectra.html.
| [
{
"created": "Fri, 27 Nov 2015 20:44:45 GMT",
"version": "v1"
},
{
"created": "Fri, 1 Jul 2016 13:41:00 GMT",
"version": "v2"
}
] | 2016-07-05 | [
[
"Elor",
"Gilly",
""
],
[
"Rodd",
"Nicholas L.",
""
],
[
"Slatyer",
"Tracy R.",
""
],
[
"Xue",
"Wei",
""
]
] | If dark matter inhabits an expanded "hidden sector", annihilations may proceed through sequential decays or multi-body final states. We map out the potential signals and current constraints on such a framework in indirect searches, using a model-independent setup based on multi-step hierarchical cascade decays. While remaining agnostic to the details of the hidden sector model, our framework captures the generic broadening of the spectrum of secondary particles (photons, neutrinos, e+e- and antiprotons) relative to the case of direct annihilation to Standard Model particles. We explore how indirect constraints on dark matter annihilation limit the parameter space for such cascade/multi-particle decays. We investigate limits from the cosmic microwave background by Planck, the Fermi measurement of photons from the dwarf galaxies, and positron data from AMS-02. The presence of a hidden sector can change the constraints on the dark matter annihilation cross section by up to an order of magnitude in either direction (although the effect can be much smaller). We find that generally the bound from the Fermi dwarfs is most constraining for annihilations to photon-rich final states, while AMS-02 is most constraining for electron and muon final states; however in certain instances the CMB bounds overtake both, due to their approximate independence of the details of the hidden sector cascade. We provide the full set of cascade spectra considered here as publicly available code with examples at http://web.mit.edu/lns/research/CascadeSpectra.html. |
0803.0218 | Thorsten Renk | Thorsten Renk | Angular variation of hard back-to-back hadron suppression in heavy-ion
collisions | 8 pages, 5 figures | Phys.Rev.C78:034904,2008 | 10.1103/PhysRevC.78.034904 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The basic idea of jet tomography is to infer information about the density
evolution of the medium created in heavy-ion (A-A) collisions by studying the
suppression of hard probes in an A-A environment as compared to the baseline
process known from p-p collisions. The suppression of back-to-back correlations
in heavy-ion collisions allows, due to a different geometrical bias, a view
into the medium which is qualitatively different from the one offered by single
hadron suppression. A control parameter for the suppression corresponding to a
systematic variation of in-medium pathlengths and density can be obtained by
studying collisions at finite impact parameter b. A systematic variation of
pathlength can then be introduced by studying the suppression pattern as a
function of the angle phi with the reaction plane. Using a 3-d hydrodynamical
evolution model for the medium and a Monte-Carlo model which has been shown to
successfully reproduce the measured suppression of back-to-back correlations in
central collisions of Au-Au at 200 AGeV, we compute the suppression as a
function of phi for b of 2.4 fm. 4.5 fm, 6.3 fm and 7.5 fm. Given that this
involves variations in both control parameters b and phi a comparison with data
should eventually allow to place strong constraints on the combination of
energy loss model and medium evolution model.
| [
{
"created": "Mon, 3 Mar 2008 11:33:34 GMT",
"version": "v1"
},
{
"created": "Wed, 23 Jul 2008 12:43:28 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Renk",
"Thorsten",
""
]
] | The basic idea of jet tomography is to infer information about the density evolution of the medium created in heavy-ion (A-A) collisions by studying the suppression of hard probes in an A-A environment as compared to the baseline process known from p-p collisions. The suppression of back-to-back correlations in heavy-ion collisions allows, due to a different geometrical bias, a view into the medium which is qualitatively different from the one offered by single hadron suppression. A control parameter for the suppression corresponding to a systematic variation of in-medium pathlengths and density can be obtained by studying collisions at finite impact parameter b. A systematic variation of pathlength can then be introduced by studying the suppression pattern as a function of the angle phi with the reaction plane. Using a 3-d hydrodynamical evolution model for the medium and a Monte-Carlo model which has been shown to successfully reproduce the measured suppression of back-to-back correlations in central collisions of Au-Au at 200 AGeV, we compute the suppression as a function of phi for b of 2.4 fm. 4.5 fm, 6.3 fm and 7.5 fm. Given that this involves variations in both control parameters b and phi a comparison with data should eventually allow to place strong constraints on the combination of energy loss model and medium evolution model. |
1904.00036 | Juan Helo | Juan Carlos Helo, Martin Hirsch and Toshihiko Ota | Proton decay at 1-loop | 13 pages, 7 figures | Phys. Rev. D 99, 095021 (2019) | 10.1103/PhysRevD.99.095021 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Proton decay is usually discussed in the context of grand unified theories.
However, as is well-known, in the standard model effective theory proton decay
appears in the form of higher dimensional non-renormalizable operators. Here,
we study systematically the 1-loop decomposition of the $d=6$ $B+L$ violating
operators. We exhaustively list the possible 1-loop ultra-violet completions of
these operators and discuss that, in general, two distinct classes of models
appear. Models in the first class need an additional symmetry in order to avoid
tree-level proton decay. These models necessarily contain a neutral particle,
which could act as a dark matter candidate. For models in the second class the
loop contribution dominates automatically over the tree-level proton decay,
without the need for additional symmetries. We also discuss possible
phenomenology of two example models, one from each class, and their possible
connections to neutrino masses, LHC searches and dark matter.
| [
{
"created": "Fri, 29 Mar 2019 18:23:34 GMT",
"version": "v1"
}
] | 2019-05-29 | [
[
"Helo",
"Juan Carlos",
""
],
[
"Hirsch",
"Martin",
""
],
[
"Ota",
"Toshihiko",
""
]
] | Proton decay is usually discussed in the context of grand unified theories. However, as is well-known, in the standard model effective theory proton decay appears in the form of higher dimensional non-renormalizable operators. Here, we study systematically the 1-loop decomposition of the $d=6$ $B+L$ violating operators. We exhaustively list the possible 1-loop ultra-violet completions of these operators and discuss that, in general, two distinct classes of models appear. Models in the first class need an additional symmetry in order to avoid tree-level proton decay. These models necessarily contain a neutral particle, which could act as a dark matter candidate. For models in the second class the loop contribution dominates automatically over the tree-level proton decay, without the need for additional symmetries. We also discuss possible phenomenology of two example models, one from each class, and their possible connections to neutrino masses, LHC searches and dark matter. |
1703.07486 | Paulo Victor Recchia Gomes Silva | D.A. Fagundes, M.J. Menon, P.V.R.G. Silva | Bounds on the rise of total cross section from LHC7 and LHC8 data | 14 pages, 3 figures, 6 tables, one appendix added (discussing some
TOTEM data at 8 TeV), minor corrections, few comments added. Matches version
accepted for publication in Nucl. Phys. A | null | 10.1016/j.nuclphysa.2017.06.057 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Recent measurements of the proton-proton total cross section $\sigma_{tot}$
at 7 and 8 TeV by the TOTEM and ATLAS Collaborations are characterized by some
discrepant values: the TOTEM data suggest a rise of the cross section with the
energy faster than the ATLAS data. Attempting to quantify these different
behaviors, we develop new analytical fits to $\sigma_{tot}$ and $\rho$ data
from $pp$ and $\bar{p}p$ scattering in the energy region 5 GeV - 8 TeV. The
dataset comprises all the accelerator data below 7 TeV and we consider three
ensembles by adding: either only the TOTEM data (T), or only the ATLAS data
(A), or both sets (T+A). For the purposes, we use our previous RRPL$\gamma$
parametrization for $\sigma_{tot}(s)$, consisting of two Reggeons (RR), one
critical Pomeron (P) and a leading log-raised-to-gamma (L$\gamma$) contribution
(with $\gamma$ as a free fit parameter), analytically connected to $\rho(s)$
through singly-subtracted derivative dispersion relations and energy scale
fixed at the physical threshold. The data reductions with ensembles T and A
present good agreement with the experimental data analyzed and cannot be
distinguished on statistical grounds. The quality of the fit is not as good
with ensemble T+A. The fit results provide $\gamma \sim 2.3 \pm 0.1$ (T), $2.0
\pm 0.2$ (A), $2.1 \pm 0.2$ (T+A), with $\chi^2/\mathrm{DOF} \sim 1.07$ (T),
$1.09$ (A), $1.14$ (T+A), suggesting extrema bounds for $\gamma$ given by 1.8
and 2.4. Fits with $\gamma = 2$ (fixed) are also developed and discussed.
| [
{
"created": "Wed, 22 Mar 2017 02:02:05 GMT",
"version": "v1"
},
{
"created": "Thu, 4 May 2017 13:24:01 GMT",
"version": "v2"
},
{
"created": "Mon, 10 Jul 2017 13:56:05 GMT",
"version": "v3"
}
] | 2017-07-11 | [
[
"Fagundes",
"D. A.",
""
],
[
"Menon",
"M. J.",
""
],
[
"Silva",
"P. V. R. G.",
""
]
] | Recent measurements of the proton-proton total cross section $\sigma_{tot}$ at 7 and 8 TeV by the TOTEM and ATLAS Collaborations are characterized by some discrepant values: the TOTEM data suggest a rise of the cross section with the energy faster than the ATLAS data. Attempting to quantify these different behaviors, we develop new analytical fits to $\sigma_{tot}$ and $\rho$ data from $pp$ and $\bar{p}p$ scattering in the energy region 5 GeV - 8 TeV. The dataset comprises all the accelerator data below 7 TeV and we consider three ensembles by adding: either only the TOTEM data (T), or only the ATLAS data (A), or both sets (T+A). For the purposes, we use our previous RRPL$\gamma$ parametrization for $\sigma_{tot}(s)$, consisting of two Reggeons (RR), one critical Pomeron (P) and a leading log-raised-to-gamma (L$\gamma$) contribution (with $\gamma$ as a free fit parameter), analytically connected to $\rho(s)$ through singly-subtracted derivative dispersion relations and energy scale fixed at the physical threshold. The data reductions with ensembles T and A present good agreement with the experimental data analyzed and cannot be distinguished on statistical grounds. The quality of the fit is not as good with ensemble T+A. The fit results provide $\gamma \sim 2.3 \pm 0.1$ (T), $2.0 \pm 0.2$ (A), $2.1 \pm 0.2$ (T+A), with $\chi^2/\mathrm{DOF} \sim 1.07$ (T), $1.09$ (A), $1.14$ (T+A), suggesting extrema bounds for $\gamma$ given by 1.8 and 2.4. Fits with $\gamma = 2$ (fixed) are also developed and discussed. |
2007.00351 | Akanksha Bhardwaj | Akanksha Bhardwaj, Juhi Dutta, Partha Konar, Biswarup Mukhopadhyaya
and Santosh Kumar Rai | Boosted jet techniques for a supersymmetric scenario with gravitino LSP | accepted for publication in JHEP | JHEP 10 (2020) 083 | 10.1007/JHEP10(2020)083 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Search for compressed supersymmetry at multi-TeV scale, in the presence of a
light gravitino dark matter, can get sizable uplift while looking into the
associated fat-jets with missing transverse momenta as a signature of the boson
produced in the decay process of much heavier next-to-lightest sparticle. We
focus on the hadronic decay of the ensuing Higgs and/or $Z$ boson giving rise
to at least two fat-jets and $\slashed{E}_T$ in the final state. We perform a
detailed background study adopting a multivariate analysis using a boosted
decision tree to provide a robust investigation to explore the discovery
potential for such signal at 14 TeV LHC considering different benchmark points
satisfying all the theoretical and experimental constraints. This channel
provides the best discovery prospects with most of the benchmarks discoverable
within an integrated luminosity of $\mathcal{L}=200$ fb$^{-1}$. Kinematic
observables are investigated in order to distinguish between compressed and
uncompressed spectra having similar event yields.
| [
{
"created": "Wed, 1 Jul 2020 09:40:39 GMT",
"version": "v1"
},
{
"created": "Thu, 3 Sep 2020 13:52:52 GMT",
"version": "v2"
}
] | 2020-10-27 | [
[
"Bhardwaj",
"Akanksha",
""
],
[
"Dutta",
"Juhi",
""
],
[
"Konar",
"Partha",
""
],
[
"Mukhopadhyaya",
"Biswarup",
""
],
[
"Rai",
"Santosh Kumar",
""
]
] | Search for compressed supersymmetry at multi-TeV scale, in the presence of a light gravitino dark matter, can get sizable uplift while looking into the associated fat-jets with missing transverse momenta as a signature of the boson produced in the decay process of much heavier next-to-lightest sparticle. We focus on the hadronic decay of the ensuing Higgs and/or $Z$ boson giving rise to at least two fat-jets and $\slashed{E}_T$ in the final state. We perform a detailed background study adopting a multivariate analysis using a boosted decision tree to provide a robust investigation to explore the discovery potential for such signal at 14 TeV LHC considering different benchmark points satisfying all the theoretical and experimental constraints. This channel provides the best discovery prospects with most of the benchmarks discoverable within an integrated luminosity of $\mathcal{L}=200$ fb$^{-1}$. Kinematic observables are investigated in order to distinguish between compressed and uncompressed spectra having similar event yields. |
hep-ph/0511054 | Misak Sargsian | Misak Sargsian (FIU) and Mark Strikman (PSU) | Model independent method for determination of the DIS structure of free
neutron | 15 pages, 4 eps figures | Phys.Lett.B639:223-231,2006 | 10.1016/j.physletb.2006.05.091 | FIU-NUPAR-110405 | hep-ph | null | We present a model independent procedure for extracting deep-inelastic
structure function of "free'' neutron from the electron - deuteron scattering
with protons produced in the target fragmentation region of the reaction. This
procedure is based on the extrapolation of t, which describes the invariant
momentum transfered to the proton, to the unphysical region corresponding to
the mass of the struck neutron. We demonstrate that the impulse approximation
diagram of the reaction has a pole at this limit with a residue being
proportional to the "free" neutron structure function. The method is analogous
to that of Chew and Low for extraction of the ``free'' pion-pion and
neutron-neutron cross sections from p(pion,p)X and d(n,n)pn reactions
respectively. We demonstrate that in the extrapolation the final state
interaction amplitudes are smooth functions of $t$ and have negligible
contribution in the extracted ``free'' nucleon structure function. We also
estimate the range of the recoil nucleon momenta which could be used for
successful extrapolation procedure.
| [
{
"created": "Sat, 5 Nov 2005 01:01:45 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Sargsian",
"Misak",
"",
"FIU"
],
[
"Strikman",
"Mark",
"",
"PSU"
]
] | We present a model independent procedure for extracting deep-inelastic structure function of "free'' neutron from the electron - deuteron scattering with protons produced in the target fragmentation region of the reaction. This procedure is based on the extrapolation of t, which describes the invariant momentum transfered to the proton, to the unphysical region corresponding to the mass of the struck neutron. We demonstrate that the impulse approximation diagram of the reaction has a pole at this limit with a residue being proportional to the "free" neutron structure function. The method is analogous to that of Chew and Low for extraction of the ``free'' pion-pion and neutron-neutron cross sections from p(pion,p)X and d(n,n)pn reactions respectively. We demonstrate that in the extrapolation the final state interaction amplitudes are smooth functions of $t$ and have negligible contribution in the extracted ``free'' nucleon structure function. We also estimate the range of the recoil nucleon momenta which could be used for successful extrapolation procedure. |
2107.00604 | Bernat Capdevila | Marzia Bordone, Bernat Capdevila, Paolo Gambino | Three loop calculations and inclusive $V_{cb}$ | 6 pages, 1 figure | null | 10.1016/j.physletb.2021.136679 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss the impact of the recent $\mathcal{O}(\alpha_s^3)$ calculations of
the semileptonic width of the $b$ quark and of the relation between pole and
kinetic heavy quark masses by Fael et al. on the inclusive determination of
$|V_{cb}|$. The most notable effect is a reduction of the uncertainty. Our
final result is $|V_{cb}|=42.16(51)\, 10^{-3}$.
| [
{
"created": "Thu, 1 Jul 2021 16:52:23 GMT",
"version": "v1"
},
{
"created": "Wed, 29 Sep 2021 09:55:38 GMT",
"version": "v2"
}
] | 2021-10-04 | [
[
"Bordone",
"Marzia",
""
],
[
"Capdevila",
"Bernat",
""
],
[
"Gambino",
"Paolo",
""
]
] | We discuss the impact of the recent $\mathcal{O}(\alpha_s^3)$ calculations of the semileptonic width of the $b$ quark and of the relation between pole and kinetic heavy quark masses by Fael et al. on the inclusive determination of $|V_{cb}|$. The most notable effect is a reduction of the uncertainty. Our final result is $|V_{cb}|=42.16(51)\, 10^{-3}$. |
hep-ph/9910263 | Johan Bijnens | Johan Bijnens | The $\Delta I=1/2$ rule and other matrix elements | Talk presented at EPS HEP99, Tampere, Finland, July 15-21,1999; uses
hep99.cls and hep990.clo | null | null | LU TP 99-29 | hep-ph | null | Recent work by J.Prades and myself on $K\to\pi\pi$ is described. The method
we use to consistently connect long and short distances is described and
numerical results for the $\Delta I=1/2$ rule and on $B_6$, the parameter
relevant for the strong part of $\epsilon'/\epsilon$, are given in the chiral
limit.
| [
{
"created": "Thu, 7 Oct 1999 10:37:44 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Bijnens",
"Johan",
""
]
] | Recent work by J.Prades and myself on $K\to\pi\pi$ is described. The method we use to consistently connect long and short distances is described and numerical results for the $\Delta I=1/2$ rule and on $B_6$, the parameter relevant for the strong part of $\epsilon'/\epsilon$, are given in the chiral limit. |
1907.10483 | Jen-Chieh Peng | Jen-Chieh Peng, Wen-Chen Chang, Randall Evan McClellan, and Oleg
Teryaev | Lepton angular distribution of Z boson production and jet discrimination | 5 pages, 5 figures. arXiv admin note: substantial text overlap with
arXiv:1708.05807 | null | 10.1016/j.physletb.2019.134895 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | High precision data of lepton angular distributions in inclusive $Z$ boson
production, reported by the CMS and ATLAS Collaborations, showed pronounced
transverse momentum ($q_T$) dependencies of the $A_0$ and $A_2$ coefficients.
Violation of the Lam-Tung relation, $A_0 = A_2$, was also found. An intuitive
understanding of these results can be obtained from a geometric approach. We
predict that $A_0$ and $A_2$ for $Z$ plus single gluon-jet events are very
different from that of $Z$ plus single quark-jet events, allowing a new
experimental tool for checking various algorithms which attempt to discriminate
quark jets from gluon jets. We also predict that the Lam-Tung relation would be
more severely violated for the $Z$ plus multiple-jet data than what has been
observed so far for inclusive $Z$ production data. These predictions can be
readily tested using existing LHC data.
| [
{
"created": "Sat, 20 Jul 2019 21:35:39 GMT",
"version": "v1"
}
] | 2019-10-02 | [
[
"Peng",
"Jen-Chieh",
""
],
[
"Chang",
"Wen-Chen",
""
],
[
"McClellan",
"Randall Evan",
""
],
[
"Teryaev",
"Oleg",
""
]
] | High precision data of lepton angular distributions in inclusive $Z$ boson production, reported by the CMS and ATLAS Collaborations, showed pronounced transverse momentum ($q_T$) dependencies of the $A_0$ and $A_2$ coefficients. Violation of the Lam-Tung relation, $A_0 = A_2$, was also found. An intuitive understanding of these results can be obtained from a geometric approach. We predict that $A_0$ and $A_2$ for $Z$ plus single gluon-jet events are very different from that of $Z$ plus single quark-jet events, allowing a new experimental tool for checking various algorithms which attempt to discriminate quark jets from gluon jets. We also predict that the Lam-Tung relation would be more severely violated for the $Z$ plus multiple-jet data than what has been observed so far for inclusive $Z$ production data. These predictions can be readily tested using existing LHC data. |
hep-ph/0408102 | David G. Cerdeno | D.G. Cerdeno, C. Hugonie, D.E. Lopez-Fogliani, C. Munoz, A.M. Teixeira | Theoretical predictions for the direct detection of neutralino dark
matter in the NMSSM | Final version to appear in JHEP. References added. LaTeX, 53 pages,
23 figures | JHEP0412:048,2004 | 10.1088/1126-6708/2004/12/048 | DESY 04-129, IFIC/04-44, FTUAM 04/17, IFT-UAM/CSIC-04-42 | hep-ph astro-ph | null | We analyse the direct detection of neutralino dark matter in the framework of
the Next-to-Minimal Supersymmetric Standard Model. After performing a detailed
analysis of the parameter space, taking into account all the available
constraints from LEPII, we compute the neutralino-nucleon cross section, and
compare the results with the sensitivity of detectors. We find that sizable
values for the detection cross section, within the reach of dark matter
detectors, are attainable in this framework. For example, neutralino-proton
cross sections compatible with the sensitivity of present experiments can be
obtained due to the exchange of very light Higgses with $m_{h_1^0}\lsim 70$
GeV. Such Higgses have a significant singlet composition, thus escaping
detection and being in agreement with accelerator data. The lightest neutralino
in these cases exhibits a large singlino-Higgsino composition, and a mass in
the range $50\lsim m_{\tilde\chi_1^0}\lsim 100$ GeV.
| [
{
"created": "Sat, 7 Aug 2004 18:46:33 GMT",
"version": "v1"
},
{
"created": "Mon, 25 Oct 2004 19:13:14 GMT",
"version": "v2"
},
{
"created": "Fri, 7 Jan 2005 03:13:39 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Cerdeno",
"D. G.",
""
],
[
"Hugonie",
"C.",
""
],
[
"Lopez-Fogliani",
"D. E.",
""
],
[
"Munoz",
"C.",
""
],
[
"Teixeira",
"A. M.",
""
]
] | We analyse the direct detection of neutralino dark matter in the framework of the Next-to-Minimal Supersymmetric Standard Model. After performing a detailed analysis of the parameter space, taking into account all the available constraints from LEPII, we compute the neutralino-nucleon cross section, and compare the results with the sensitivity of detectors. We find that sizable values for the detection cross section, within the reach of dark matter detectors, are attainable in this framework. For example, neutralino-proton cross sections compatible with the sensitivity of present experiments can be obtained due to the exchange of very light Higgses with $m_{h_1^0}\lsim 70$ GeV. Such Higgses have a significant singlet composition, thus escaping detection and being in agreement with accelerator data. The lightest neutralino in these cases exhibits a large singlino-Higgsino composition, and a mass in the range $50\lsim m_{\tilde\chi_1^0}\lsim 100$ GeV. |
1708.09024 | Knut Bakke | R. L. L. Vitoria, H. Belich and K. Bakke | Coulomb-type interaction under Lorentz symmetry breaking effects | 10 pages, no figure | Advances in High Energy Physics 2017, 6893084 (2017) | 10.1155/2017/6893084 | null | hep-ph hep-th quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Based on models of confinement of quarks, we analyse a relativistic scalar
particle subject to a scalar potential proportional to the inverse of the
radial distance and under the effects of the violation of the Lorentz symmetry.
We show that the effects of the Lorentz symmetry breaking can induced a
harmonic-type potential. Then, we solve the Klein-Gordon equation analytically
and discuss the influence of the background of the violation of the Lorentz
symmetry on the relativistic energy levels.
| [
{
"created": "Mon, 28 Aug 2017 11:55:01 GMT",
"version": "v1"
}
] | 2017-09-11 | [
[
"Vitoria",
"R. L. L.",
""
],
[
"Belich",
"H.",
""
],
[
"Bakke",
"K.",
""
]
] | Based on models of confinement of quarks, we analyse a relativistic scalar particle subject to a scalar potential proportional to the inverse of the radial distance and under the effects of the violation of the Lorentz symmetry. We show that the effects of the Lorentz symmetry breaking can induced a harmonic-type potential. Then, we solve the Klein-Gordon equation analytically and discuss the influence of the background of the violation of the Lorentz symmetry on the relativistic energy levels. |
2301.04059 | Luca Rottoli | Luca Rottoli, Paolo Torrielli, Alessandro Vicini | Determination of the $W$-boson mass at hadron colliders | 6 pages, 5 figures. Final version published in EPJC | null | 10.1140/epjc/s10052-023-12128-z | ZU-TH 01/23, TIF-UNIMI-2023-1 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We introduce an observable relevant for the determination of the $W$-boson
mass $m_W$ at hadron colliders. This observable is defined as an asymmetry
around the jacobian peak of the charged-lepton transverse-momentum distribution
in the charged-current Drell-Yan process. We discuss the observable's
theoretical prediction, presenting results at different orders in QCD, and
showing its perturbative stability. Its definition as a single scalar number
and its linear sensitivity to $m_W$ allow a clean extraction of the latter and
a straightforward discussion of the associated theoretical systematics: a
perturbative QCD uncertainty of ${\cal O}(\pm 5)$ MeV on $m_W$ can be
established by means of this observable, relying solely on charged-current
Drell-Yan information. Owing to its relatively inclusive nature, the observable
displays desirable properties also from the experimental viewpoint, especially
for the unfolding of detector effects. We show that a measurement of this
observable can lead to a competitive experimental error on $m_W$ at the LHC.
| [
{
"created": "Tue, 10 Jan 2023 16:22:51 GMT",
"version": "v1"
},
{
"created": "Fri, 12 Apr 2024 06:38:12 GMT",
"version": "v2"
}
] | 2024-04-15 | [
[
"Rottoli",
"Luca",
""
],
[
"Torrielli",
"Paolo",
""
],
[
"Vicini",
"Alessandro",
""
]
] | We introduce an observable relevant for the determination of the $W$-boson mass $m_W$ at hadron colliders. This observable is defined as an asymmetry around the jacobian peak of the charged-lepton transverse-momentum distribution in the charged-current Drell-Yan process. We discuss the observable's theoretical prediction, presenting results at different orders in QCD, and showing its perturbative stability. Its definition as a single scalar number and its linear sensitivity to $m_W$ allow a clean extraction of the latter and a straightforward discussion of the associated theoretical systematics: a perturbative QCD uncertainty of ${\cal O}(\pm 5)$ MeV on $m_W$ can be established by means of this observable, relying solely on charged-current Drell-Yan information. Owing to its relatively inclusive nature, the observable displays desirable properties also from the experimental viewpoint, especially for the unfolding of detector effects. We show that a measurement of this observable can lead to a competitive experimental error on $m_W$ at the LHC. |
2306.03008 | Di Zhang | Di Zhang | Renormalization Group Equations for the SMEFT Operators up to Dimension
Seven | 42 pages, references added, and the version accepted for publication
in JHEP | null | null | TUM-HEP 1460/23 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper, we propose a Green's basis and also a new physical basis for
dimension-seven (dim-7) operators, which are suitable for the matching of
ultraviolet models onto the Standard Model effective field theory (SMEFT) and
the deviation of renormalization group equations (RGEs) for dim-7 operators in
the SMEFT. The reduction relations to convert operators in the Green's basis to
those in the physical basis are achieved as well, where some redundant dim-6
operators in the Green's basis are involved if the dim-5 operator exists.
Working in these two bases for dim-7 operators and with the help of the
reduction relations, we work out the one-loop RGEs resulting from the mixing
among different dimensional operators for the dim-5 and dim-7 operators up to
$\mathcal{O} \left( \Lambda^{-3} \right)$ in the SMEFT. These new results
complete the previous results for RGEs of the dim-5 and dim-7 operators and
hence can be used for a consistent one-loop analysis of the SMEFT at
$\mathcal{O} \left( \Lambda^{-3} \right)$.
| [
{
"created": "Mon, 5 Jun 2023 16:19:12 GMT",
"version": "v1"
},
{
"created": "Mon, 16 Oct 2023 20:08:19 GMT",
"version": "v2"
}
] | 2023-10-18 | [
[
"Zhang",
"Di",
""
]
] | In this paper, we propose a Green's basis and also a new physical basis for dimension-seven (dim-7) operators, which are suitable for the matching of ultraviolet models onto the Standard Model effective field theory (SMEFT) and the deviation of renormalization group equations (RGEs) for dim-7 operators in the SMEFT. The reduction relations to convert operators in the Green's basis to those in the physical basis are achieved as well, where some redundant dim-6 operators in the Green's basis are involved if the dim-5 operator exists. Working in these two bases for dim-7 operators and with the help of the reduction relations, we work out the one-loop RGEs resulting from the mixing among different dimensional operators for the dim-5 and dim-7 operators up to $\mathcal{O} \left( \Lambda^{-3} \right)$ in the SMEFT. These new results complete the previous results for RGEs of the dim-5 and dim-7 operators and hence can be used for a consistent one-loop analysis of the SMEFT at $\mathcal{O} \left( \Lambda^{-3} \right)$. |
0704.1674 | Thomas A. Trainor | Thomas A. Trainor and David T. Kettler | The azimuth structure of nuclear collisions -- I | 27 pages, 12 figures | Int.J.Mod.Phys.E17:1219-1272,2008 | 10.1142/S0218301308010465 | null | hep-ph | null | We describe azimuth structure commonly associated with elliptic and directed
flow in the context of 2D angular autocorrelations for the purpose of precise
separation of so-called nonflow (mainly minijets) from flow. We extend the
Fourier-transform description of azimuth structure to include power spectra and
autocorrelations related by the Wiener-Khintchine theorem. We analyze several
examples of conventional flow analysis in that context and question the
relevance of reaction plane estimation to flow analysis. We introduce the 2D
angular autocorrelation with examples from data analysis and describe a
simulation exercise which demonstrates precise separation of flow and nonflow
using the 2D autocorrelation method. We show that an alternative correlation
measure based on Pearson's normalized covariance provides a more intuitive
measure of azimuth structure.
| [
{
"created": "Thu, 12 Apr 2007 23:08:44 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Trainor",
"Thomas A.",
""
],
[
"Kettler",
"David T.",
""
]
] | We describe azimuth structure commonly associated with elliptic and directed flow in the context of 2D angular autocorrelations for the purpose of precise separation of so-called nonflow (mainly minijets) from flow. We extend the Fourier-transform description of azimuth structure to include power spectra and autocorrelations related by the Wiener-Khintchine theorem. We analyze several examples of conventional flow analysis in that context and question the relevance of reaction plane estimation to flow analysis. We introduce the 2D angular autocorrelation with examples from data analysis and describe a simulation exercise which demonstrates precise separation of flow and nonflow using the 2D autocorrelation method. We show that an alternative correlation measure based on Pearson's normalized covariance provides a more intuitive measure of azimuth structure. |
hep-ph/0607276 | Sebastian Sapeta | K.Golec-Biernat, S.Sapeta | Heavy flavour production in DGLAP improved saturation model | 16 pages, 7 figures; typos corrected, references added, final
Phys.Rev. D version | Phys.Rev.D74:054032,2006 | 10.1103/PhysRevD.74.054032 | null | hep-ph | null | The charm and beauty quark production in deep inelastic scattering at low
values of the Bjorken variable x is considered in the DGLAP improved saturation
model. After fitting parameters of the model to the structure function F_2, the
heavy quark contributions Fc_2 and Fb_2 are predicted. A good description of
the data is found. Predictions for the longitudinal structure function F_L and
the diffractive structure function FD_2 are also presented.
| [
{
"created": "Tue, 25 Jul 2006 14:41:56 GMT",
"version": "v1"
},
{
"created": "Fri, 8 Sep 2006 08:19:35 GMT",
"version": "v2"
},
{
"created": "Wed, 27 Sep 2006 10:09:39 GMT",
"version": "v3"
}
] | 2010-03-25 | [
[
"Golec-Biernat",
"K.",
""
],
[
"Sapeta",
"S.",
""
]
] | The charm and beauty quark production in deep inelastic scattering at low values of the Bjorken variable x is considered in the DGLAP improved saturation model. After fitting parameters of the model to the structure function F_2, the heavy quark contributions Fc_2 and Fb_2 are predicted. A good description of the data is found. Predictions for the longitudinal structure function F_L and the diffractive structure function FD_2 are also presented. |
1201.0687 | Juergen Berges | J. Berges, D. Sexty | Bose condensation far from equilibrium | 4 pages, 5 figures, PRL version, minor changes | null | 10.1103/PhysRevLett.108.161601 | null | hep-ph cond-mat.quant-gas nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The formation of Bose condensates far from equilibrium can play an important
role in our understanding of collision experiments of heavy nuclei or for the
evolution of the early universe. In the relativistic quantum world particle
number changing processes can counteract Bose condensation, and there is a
considerable debate about the relevance of this phenomenon in this context. We
show that the involved question of Bose condensation from initial
over-population can be answered for the example of scalar field theories.
Condensate formation occurs as a consequence of an inverse particle cascade
with a universal power-law spectrum. This particle transport towards low
momenta is part of a dual cascade, in which energy is also transfered by weak
wave turbulence towards higher momenta. To highlight the importance of number
changing processes for the subsequent decay of the condensate, we also compare
to non-relativistic theories with exact number conservation. We discuss the
relevance of these results for nonabelian gauge theories.
| [
{
"created": "Tue, 3 Jan 2012 16:26:13 GMT",
"version": "v1"
},
{
"created": "Fri, 9 Mar 2012 07:41:14 GMT",
"version": "v2"
}
] | 2015-06-03 | [
[
"Berges",
"J.",
""
],
[
"Sexty",
"D.",
""
]
] | The formation of Bose condensates far from equilibrium can play an important role in our understanding of collision experiments of heavy nuclei or for the evolution of the early universe. In the relativistic quantum world particle number changing processes can counteract Bose condensation, and there is a considerable debate about the relevance of this phenomenon in this context. We show that the involved question of Bose condensation from initial over-population can be answered for the example of scalar field theories. Condensate formation occurs as a consequence of an inverse particle cascade with a universal power-law spectrum. This particle transport towards low momenta is part of a dual cascade, in which energy is also transfered by weak wave turbulence towards higher momenta. To highlight the importance of number changing processes for the subsequent decay of the condensate, we also compare to non-relativistic theories with exact number conservation. We discuss the relevance of these results for nonabelian gauge theories. |
hep-ph/9711337 | Michelangelo Mangano | M.L. Mangano | Two lectures on heavy quark production in hadronic collisions | 39 pages, Latex, epsfig, 36 figures. Presented at the International
School of Physics `E. Fermi', Course CXXXVII, Heavy flavour physics: a probe
of Nature's grand design | null | null | CERN-TH/97-328 | hep-ph | null | These lectures present a pedagogical introduction to the physics of
heavy-flavour production in hadronic collisions. The first lecture gives the
theoretical background, with a discussion of leading-order calculations and of
the effects of next-to-leading-order corrections. The origin and implications
of the large logarithmic corrections appearing at this order are presented in
an elementary way. The second lecture provides a survey of current experimental
data on charm and bottom production, and describes their comparison with
theoretical predictions. We emphasize the role played by some non-perturbative
effects in the determination of charm distributions, and study the theoretical
systematic uncertainties which affect our predictions.
| [
{
"created": "Fri, 14 Nov 1997 16:50:47 GMT",
"version": "v1"
}
] | 2009-09-25 | [
[
"Mangano",
"M. L.",
""
]
] | These lectures present a pedagogical introduction to the physics of heavy-flavour production in hadronic collisions. The first lecture gives the theoretical background, with a discussion of leading-order calculations and of the effects of next-to-leading-order corrections. The origin and implications of the large logarithmic corrections appearing at this order are presented in an elementary way. The second lecture provides a survey of current experimental data on charm and bottom production, and describes their comparison with theoretical predictions. We emphasize the role played by some non-perturbative effects in the determination of charm distributions, and study the theoretical systematic uncertainties which affect our predictions. |
hep-ph/0606295 | Yuji Koike | Yuji Koike, Junji Nagashima (Niigata Univ.) and Werner Vogelsang (BNL) | Q_T-Resummation for Polarized Semi-Inclusive Deep Inelastic Scattering | Talk presented at DIS2006. 4 pages, 3 figures | null | 10.1142/9789812706706_0183 | BNL-NT-06/22 | hep-ph | null | We study the transverse-momentum distribution of hadrons produced in
semi-inclusive deep-inelastic scattering. We consider cross sections for
various combinations of the polarizations of the initial lepton and nucleon or
the produced hadron, for which we perform the resummation of large
double-logarithmic perturbative corrections arising at small transverse
momentum. We present phenomenological results for the process $ep\to e\pi X$
for the typical kinematics in the COMPASS experiment. We discuss the impact of
the perturbative resummation and of estimated non-perturbative contributions on
the corresponding cross sections and their spin asymmetry.
| [
{
"created": "Thu, 29 Jun 2006 00:23:21 GMT",
"version": "v1"
}
] | 2017-08-23 | [
[
"Koike",
"Yuji",
"",
"Niigata Univ."
],
[
"Nagashima",
"Junji",
"",
"Niigata Univ."
],
[
"Vogelsang",
"Werner",
"",
"BNL"
]
] | We study the transverse-momentum distribution of hadrons produced in semi-inclusive deep-inelastic scattering. We consider cross sections for various combinations of the polarizations of the initial lepton and nucleon or the produced hadron, for which we perform the resummation of large double-logarithmic perturbative corrections arising at small transverse momentum. We present phenomenological results for the process $ep\to e\pi X$ for the typical kinematics in the COMPASS experiment. We discuss the impact of the perturbative resummation and of estimated non-perturbative contributions on the corresponding cross sections and their spin asymmetry. |
hep-ph/9401301 | Peter Cho | Peter Cho and Mark B. Wise | Comment on $D_s^* \to D_s \pi^0$ Decay | 7 pages with 2 figures not included but available upon request,
CALT-68-1914 | Phys.Rev. D49 (1994) 6228-6231 | 10.1103/PhysRevD.49.6228 | null | hep-ph | null | We calculate the rate for $D_s^* \rightarrow D_s \pi^0$ decay using Chiral
Perturbation Theory. This isospin violating process results from $\pi^0$ -
$\eta$ mixing, and its amplitude is proportional to $(m_d -
m_u)/\bigl(m_s-(m_u+m_d)/2 \bigr)$. Experimental information on the branching
ratio for $D_s^* \rightarrow D_s \pi^0$ can provide insight into the pattern of
$SU(3)$ violation in radiative $D^*$ decays.
| [
{
"created": "Fri, 21 Jan 1994 01:32:45 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Cho",
"Peter",
""
],
[
"Wise",
"Mark B.",
""
]
] | We calculate the rate for $D_s^* \rightarrow D_s \pi^0$ decay using Chiral Perturbation Theory. This isospin violating process results from $\pi^0$ - $\eta$ mixing, and its amplitude is proportional to $(m_d - m_u)/\bigl(m_s-(m_u+m_d)/2 \bigr)$. Experimental information on the branching ratio for $D_s^* \rightarrow D_s \pi^0$ can provide insight into the pattern of $SU(3)$ violation in radiative $D^*$ decays. |
hep-ph/9711302 | Thomas Hahn | A. Denner, T. Hahn | Radiative Corrections to W^+W^- \to W^+W^- in the Electroweak Standard
Model | 24 pages, LaTeX, uses axodraw, epsfig. Statement clarified | Nucl.Phys.B525:27-50,1998 | 10.1016/S0550-3213(98)00287-9 | PSI-PR-97-31, KA-TP-16-1997 | hep-ph | null | The cross-section for W^+W^- \to W^+W^- with arbitrarily polarized W bosons
is calculated within the Electroweak Standard Model including the complete
virtual and soft-photonic O(alpha) corrections. We show the numerical
importance of the radiative corrections for the dominating polarized
cross-sections and for the unpolarized cross-section. The numerical accuracy of
the equivalence theorem is investigated in O(alpha) by comparing the
cross-section for purely longitudinal W bosons obtained from the equivalence
theorem and from the direct calculation. We point out that the instability of
the W boson, which is inherent in the one-loop corrections, prevents a
consistent calculation of radiative corrections to the scattering of
on-real-mass-shell longitudinal W bosons beyond O(alpha).
| [
{
"created": "Wed, 12 Nov 1997 12:17:59 GMT",
"version": "v1"
},
{
"created": "Tue, 24 Mar 1998 10:01:01 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Denner",
"A.",
""
],
[
"Hahn",
"T.",
""
]
] | The cross-section for W^+W^- \to W^+W^- with arbitrarily polarized W bosons is calculated within the Electroweak Standard Model including the complete virtual and soft-photonic O(alpha) corrections. We show the numerical importance of the radiative corrections for the dominating polarized cross-sections and for the unpolarized cross-section. The numerical accuracy of the equivalence theorem is investigated in O(alpha) by comparing the cross-section for purely longitudinal W bosons obtained from the equivalence theorem and from the direct calculation. We point out that the instability of the W boson, which is inherent in the one-loop corrections, prevents a consistent calculation of radiative corrections to the scattering of on-real-mass-shell longitudinal W bosons beyond O(alpha). |
1303.5696 | Krzysztof Rolbiecki | Krzysztof Rolbiecki and Kazuki Sakurai | Light stops emerging in WW cross section measurements? | 16 pages, 5 figures, minor revision, discussion of asymmetry
expanded, to appear in JHEP | null | 10.1007/JHEP09(2013)004 | DESY-13-052 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Recent ATLAS and CMS measurements show a slight excess in the WW cross
section measurement. While still consistent with the Standard Model within 1-2
sigma, the excess could be also a first hint of physics beyond the Standard
Model. We argue that this effect could be attributed to the production of
scalar top quarks within supersymmetric models. The stops of mstop_1 ~ 200 GeV
has the right pair-production cross section and under some assumptions can
significantly contribute to the final state of two leptons and missing energy.
We scan this region of parameter space to identify stop mass range preferred by
the WW cross section measurements. Taking one sample benchmark point we show
that it can be consistent with low energy observables and Higgs sector
measurements and propose a method to distinguish supersymmetric signal from the
Standard Model contribution.
| [
{
"created": "Fri, 22 Mar 2013 19:33:53 GMT",
"version": "v1"
},
{
"created": "Mon, 12 Aug 2013 21:12:46 GMT",
"version": "v2"
}
] | 2015-06-15 | [
[
"Rolbiecki",
"Krzysztof",
""
],
[
"Sakurai",
"Kazuki",
""
]
] | Recent ATLAS and CMS measurements show a slight excess in the WW cross section measurement. While still consistent with the Standard Model within 1-2 sigma, the excess could be also a first hint of physics beyond the Standard Model. We argue that this effect could be attributed to the production of scalar top quarks within supersymmetric models. The stops of mstop_1 ~ 200 GeV has the right pair-production cross section and under some assumptions can significantly contribute to the final state of two leptons and missing energy. We scan this region of parameter space to identify stop mass range preferred by the WW cross section measurements. Taking one sample benchmark point we show that it can be consistent with low energy observables and Higgs sector measurements and propose a method to distinguish supersymmetric signal from the Standard Model contribution. |
2008.10251 | Javier Relancio | J.M. Carmona, J.L. Cort\'es, L. Pereira, J.J. Relancio | Bounds on Relativistic Deformed Kinematics from the Physics of the
Universe Transparency | 14 pages, paper published in Symmetry | Symmetry 2020, 12(8), 1298 | 10.3390/sym12081298 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We analyze the kinematics of electron-positron production in a photon-photon
interaction when one has a modification of the special relativistic kinematics
as a power expansion in the inverse of a new high-energy scale. We derive the
equation for the threshold energy of this reaction to first order in this
expansion, including the effects due to a modification of the energy-momentum
conservation equation. In contrast with the Lorentz invariance violation case,
a scale of the order of a few TeV is found to be compatible with the
observations of very high-energy cosmic gamma rays in the case of a
modification compatible with the relativity principle.
| [
{
"created": "Mon, 24 Aug 2020 08:31:13 GMT",
"version": "v1"
}
] | 2020-08-25 | [
[
"Carmona",
"J. M.",
""
],
[
"Cortés",
"J. L.",
""
],
[
"Pereira",
"L.",
""
],
[
"Relancio",
"J. J.",
""
]
] | We analyze the kinematics of electron-positron production in a photon-photon interaction when one has a modification of the special relativistic kinematics as a power expansion in the inverse of a new high-energy scale. We derive the equation for the threshold energy of this reaction to first order in this expansion, including the effects due to a modification of the energy-momentum conservation equation. In contrast with the Lorentz invariance violation case, a scale of the order of a few TeV is found to be compatible with the observations of very high-energy cosmic gamma rays in the case of a modification compatible with the relativity principle. |
2101.09910 | Chao Shi | Chao Shi, Ya-Ping Xie, Ming Li, Xurong Chen and Hong-Shi Zong | The light front wave functions and diffractive electroproduction of
vector mesons | 10 pages, 4 figures | null | 10.1103/PhysRevD.104.L091902 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We determine the leading Fock-state light front wave functions (LF-LFWFs) of
the $\rho$ and J/$\psi$ mesons, for the first time from the Dyson-Schwinger and
Bethe-Salpeter equations (DS-BSEs) approach. A unique advantage of this method
is that it renders a direct extraction of LF-LFWFs in presence of a number of
higher Fock-states. Modulated by the current quark mass and driven by the
dynamical chiral symmetry breaking (DCSB), we find the $\rho$ and $J/\psi$
LF-LFWFs different in profile, i.e., the former are broadly distributed in $x$
(the longitudinal light-cone momentum fraction of meson carried by quark) while
the latter are narrow. Moreover, the $\rho$ LF-LFWFs contribute less than 50%
to the total Fock-state normalization, suggesting considerable higher
Fock-states in $\rho$. We then use these LF-LFWFs to study the diffractive
$\rho$ and $J/\psi$ electroproduction within the dipole picture. The calculated
cross section shows general agreement with HEAR data, except for growing
discrepancy in $\rho$ production at low photon virtuality. Our work provides a
first dipole picture analysis on diffractive $\rho$ electroproduction that
confronts the parton nature of the light (anti)quarks.
| [
{
"created": "Mon, 25 Jan 2021 06:37:28 GMT",
"version": "v1"
},
{
"created": "Sun, 31 Jan 2021 23:55:17 GMT",
"version": "v2"
},
{
"created": "Sun, 2 May 2021 01:01:24 GMT",
"version": "v3"
}
] | 2021-11-17 | [
[
"Shi",
"Chao",
""
],
[
"Xie",
"Ya-Ping",
""
],
[
"Li",
"Ming",
""
],
[
"Chen",
"Xurong",
""
],
[
"Zong",
"Hong-Shi",
""
]
] | We determine the leading Fock-state light front wave functions (LF-LFWFs) of the $\rho$ and J/$\psi$ mesons, for the first time from the Dyson-Schwinger and Bethe-Salpeter equations (DS-BSEs) approach. A unique advantage of this method is that it renders a direct extraction of LF-LFWFs in presence of a number of higher Fock-states. Modulated by the current quark mass and driven by the dynamical chiral symmetry breaking (DCSB), we find the $\rho$ and $J/\psi$ LF-LFWFs different in profile, i.e., the former are broadly distributed in $x$ (the longitudinal light-cone momentum fraction of meson carried by quark) while the latter are narrow. Moreover, the $\rho$ LF-LFWFs contribute less than 50% to the total Fock-state normalization, suggesting considerable higher Fock-states in $\rho$. We then use these LF-LFWFs to study the diffractive $\rho$ and $J/\psi$ electroproduction within the dipole picture. The calculated cross section shows general agreement with HEAR data, except for growing discrepancy in $\rho$ production at low photon virtuality. Our work provides a first dipole picture analysis on diffractive $\rho$ electroproduction that confronts the parton nature of the light (anti)quarks. |
hep-ph/0408033 | Harmen J. Warringa | Jens O. Andersen, Daniel Boer, Harmen J. Warringa | Thermodynamics of O(N) sigma models: 1/N corrections | 11 pages, 5 figures, revtex | Phys.Rev. D70 (2004) 116007 | 10.1103/PhysRevD.70.116007 | null | hep-ph | null | The thermodynamics of the O(N) linear and nonlinear sigma models in 3+1
dimensions is studied. We calculate the pressure to next-to-leading order in
the 1/N expansion and show that at this order, temperature-independent
renormalization is only possible at the minimum of the effective potential. The
1/N expansion is found to be a good expansion for N as low as 4, which is the
case relevant for low-energy QCD phenomenology. We consider the cases with and
without explicit symmetry breaking. We show that previous next-to-leading order
calculations of the pressure are either breaking down in the temperatures of
interest, or based on unjustifiable high-energy approximations.
| [
{
"created": "Tue, 3 Aug 2004 12:09:19 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Andersen",
"Jens O.",
""
],
[
"Boer",
"Daniel",
""
],
[
"Warringa",
"Harmen J.",
""
]
] | The thermodynamics of the O(N) linear and nonlinear sigma models in 3+1 dimensions is studied. We calculate the pressure to next-to-leading order in the 1/N expansion and show that at this order, temperature-independent renormalization is only possible at the minimum of the effective potential. The 1/N expansion is found to be a good expansion for N as low as 4, which is the case relevant for low-energy QCD phenomenology. We consider the cases with and without explicit symmetry breaking. We show that previous next-to-leading order calculations of the pressure are either breaking down in the temperatures of interest, or based on unjustifiable high-energy approximations. |
1006.0131 | Archil Kobakhidze | Robert Foot, Archil Kobakhidze and Raymond R. Volkas | Stable mass hierarchies and dark matter from hidden sectors in the
scale-invariant standard model | v2: minor changes, reference added, published in Phys. Rev. D | Phys.Rev.D82:035005,2010 | 10.1103/PhysRevD.82.035005 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Scale invariance may be a classical symmetry which is broken radiatively.
This provides a simple way to stabilise the scale of electroweak symmetry
breaking against radiative corrections. But for such a theory to be fully
realistic, it must actually incorporate a hierarchy of scales, including the
Planck and the neutrino mass scales in addition to the electroweak scale. The
dark matter sector and the physics responsible for baryogenesis may or may not
require new scales, depending on the scenario. We develop a generic way of
using hidden sectors to construct a technically-natural hierarchy of scales in
the framework of classically scale-invariant theories. We then apply the method
to generate the Planck mass and to solve the neutrino mass and dark matter
problems through what may be termed the "scale-invariant standard model". The
model is perturbatively renormalisable for energy scales up to the Planck mass.
| [
{
"created": "Tue, 1 Jun 2010 13:34:20 GMT",
"version": "v1"
},
{
"created": "Sat, 7 Aug 2010 14:54:19 GMT",
"version": "v2"
}
] | 2014-11-21 | [
[
"Foot",
"Robert",
""
],
[
"Kobakhidze",
"Archil",
""
],
[
"Volkas",
"Raymond R.",
""
]
] | Scale invariance may be a classical symmetry which is broken radiatively. This provides a simple way to stabilise the scale of electroweak symmetry breaking against radiative corrections. But for such a theory to be fully realistic, it must actually incorporate a hierarchy of scales, including the Planck and the neutrino mass scales in addition to the electroweak scale. The dark matter sector and the physics responsible for baryogenesis may or may not require new scales, depending on the scenario. We develop a generic way of using hidden sectors to construct a technically-natural hierarchy of scales in the framework of classically scale-invariant theories. We then apply the method to generate the Planck mass and to solve the neutrino mass and dark matter problems through what may be termed the "scale-invariant standard model". The model is perturbatively renormalisable for energy scales up to the Planck mass. |
2201.03272 | Alberto Lusiani | Alberto Lusiani | Updated determinations of |V$_{us}$| with tau decays using new recent
estimates of radiative corrections for light-meson leptonic decay rates | Submission to SciPost, v2: added a reference, use now Proceedings
SciPost document options; 5 pages including references, 1 figure, proceedings
of "The 16th International Workshop on Tau Lepton Physics (TAU2021) (Virtual
Edition)", from September 27th to October 1st 2021, Indiana University | null | null | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | We update the |V$_{us}$| determinations using the HFLAV 2018 report tau
branching fraction results with recent new estimates of the $\pi\ell2$ and
$K\ell2$ radiative corrections. There are minor changes of the central values
and uncertainties.
| [
{
"created": "Mon, 10 Jan 2022 10:42:16 GMT",
"version": "v1"
},
{
"created": "Tue, 11 Jan 2022 22:33:10 GMT",
"version": "v2"
}
] | 2022-01-13 | [
[
"Lusiani",
"Alberto",
""
]
] | We update the |V$_{us}$| determinations using the HFLAV 2018 report tau branching fraction results with recent new estimates of the $\pi\ell2$ and $K\ell2$ radiative corrections. There are minor changes of the central values and uncertainties. |
1107.4580 | Adam Ritz | Patrick deNiverville, Maxim Pospelov, Adam Ritz | Observing a light dark matter beam with neutrino experiments | 19 pages, 5 figures; v2: typos corrected, to appear in Phys. Rev. D;
v3: note added clarifying the parameter range excluded by LSND | null | 10.1103/PhysRevD.84.075020 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider the sensitivity of fixed-target neutrino experiments at the
luminosity frontier to light stable states, such as those present in models of
MeV-scale dark matter. To ensure the correct thermal relic abundance, such
states must annihilate via light mediators, which in turn provide an access
portal for direct production in colliders or fixed targets. Indeed, this
framework endows the neutrino beams produced at fixed-target facilities with a
companion `dark matter beam', which may be detected via an excess of elastic
scattering events off electrons or nuclei in the (near-)detector. We study the
high luminosity proton fixed-target experiments at LSND and MiniBooNE, and
determine that the ensuing sensitivity to light dark matter generally surpasses
that of other direct probes. For scenarios with a kinetically-mixed U(1)'
vector mediator of mass m_V, we find that a large volume of parameter space is
excluded for m_DM ~ 1-5 MeV, covering vector masses 2 m_DM < m_V < m_eta and a
range of kinetic mixing parameters reaching as low as kappa ~ 10^{-5}. The
corresponding MeV-scale dark matter scenarios motivated by an explanation of
the galactic 511 keV line are thus strongly constrained.
| [
{
"created": "Fri, 22 Jul 2011 17:21:06 GMT",
"version": "v1"
},
{
"created": "Tue, 4 Oct 2011 21:35:33 GMT",
"version": "v2"
},
{
"created": "Wed, 14 Aug 2013 01:10:53 GMT",
"version": "v3"
}
] | 2015-03-19 | [
[
"deNiverville",
"Patrick",
""
],
[
"Pospelov",
"Maxim",
""
],
[
"Ritz",
"Adam",
""
]
] | We consider the sensitivity of fixed-target neutrino experiments at the luminosity frontier to light stable states, such as those present in models of MeV-scale dark matter. To ensure the correct thermal relic abundance, such states must annihilate via light mediators, which in turn provide an access portal for direct production in colliders or fixed targets. Indeed, this framework endows the neutrino beams produced at fixed-target facilities with a companion `dark matter beam', which may be detected via an excess of elastic scattering events off electrons or nuclei in the (near-)detector. We study the high luminosity proton fixed-target experiments at LSND and MiniBooNE, and determine that the ensuing sensitivity to light dark matter generally surpasses that of other direct probes. For scenarios with a kinetically-mixed U(1)' vector mediator of mass m_V, we find that a large volume of parameter space is excluded for m_DM ~ 1-5 MeV, covering vector masses 2 m_DM < m_V < m_eta and a range of kinetic mixing parameters reaching as low as kappa ~ 10^{-5}. The corresponding MeV-scale dark matter scenarios motivated by an explanation of the galactic 511 keV line are thus strongly constrained. |
1509.02929 | Howard Baer | Howard Baer, Vernon Barger and Michael Savoy | Upper bounds on sparticle masses from naturalness or how to disprove
weak scale supersymmetry | 31 pages, 15 figures; version 3 includes dominant two-loop
contributions to scalar potential which provide a bound on m(gluino) in the
pMSSM | Phys. Rev. D 93, 035016 (2016) | 10.1103/PhysRevD.93.035016 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | While it is often stated that the notion of electroweak (EW) naturalness in
supersymmetric models is subjective, fuzzy and model-dependent, here we argue
the contrary: electroweak naturalness can be elevated to a {\it principle}
which is both objective and predictive. We demonstrate visually when too much
fine-tuning sets in at the electroweak scale which corresponds numerically to
the measure \Delta_{BG}~\Delta_{EW}> 30. While many constrained SUSY models are
already excluded by this value, we derive updated upper bounds on sparticle
masses within the two-extra parameter non-universal Higgs model (NUHM2). We
confirm the classic Barbieri-Giudice (BG) result that \Delta_{BG}<30 implies mu
<350 GeV. However, by combining dependent soft terms which appear as multiples
of m_{3/2} in supergravity models, then we obtain m(gluino)< 4 TeV as opposed
to the BG result that m(gluino)<350 GeV. We compare the NUHM2 results to a
similar scan in the pMSSM with 19 weak scale parameters. In the pMSSM with
complete one-loop scalar potential plus dominant two-loop terms, then a
m(gluino)<7 TeV bound is found. Our tabulation of upper bounds provides a
target for experimenters seeking to discover or else falsify the existence of
weak scale supersymmetry. In an Appendix, we show contributions to the
naturalness measure from one-loop contributions to the weak scale scalar
potential.
| [
{
"created": "Wed, 9 Sep 2015 20:16:03 GMT",
"version": "v1"
},
{
"created": "Wed, 23 Sep 2015 14:36:28 GMT",
"version": "v2"
},
{
"created": "Fri, 22 Jan 2016 15:18:44 GMT",
"version": "v3"
}
] | 2016-02-24 | [
[
"Baer",
"Howard",
""
],
[
"Barger",
"Vernon",
""
],
[
"Savoy",
"Michael",
""
]
] | While it is often stated that the notion of electroweak (EW) naturalness in supersymmetric models is subjective, fuzzy and model-dependent, here we argue the contrary: electroweak naturalness can be elevated to a {\it principle} which is both objective and predictive. We demonstrate visually when too much fine-tuning sets in at the electroweak scale which corresponds numerically to the measure \Delta_{BG}~\Delta_{EW}> 30. While many constrained SUSY models are already excluded by this value, we derive updated upper bounds on sparticle masses within the two-extra parameter non-universal Higgs model (NUHM2). We confirm the classic Barbieri-Giudice (BG) result that \Delta_{BG}<30 implies mu <350 GeV. However, by combining dependent soft terms which appear as multiples of m_{3/2} in supergravity models, then we obtain m(gluino)< 4 TeV as opposed to the BG result that m(gluino)<350 GeV. We compare the NUHM2 results to a similar scan in the pMSSM with 19 weak scale parameters. In the pMSSM with complete one-loop scalar potential plus dominant two-loop terms, then a m(gluino)<7 TeV bound is found. Our tabulation of upper bounds provides a target for experimenters seeking to discover or else falsify the existence of weak scale supersymmetry. In an Appendix, we show contributions to the naturalness measure from one-loop contributions to the weak scale scalar potential. |
2012.11621 | Venus Keus | J. Hernandez-Sanchez, V. Keus, S. Moretti, D. Rojas-Ciofalo, D.
Sokolowska | Complementary Probes of Two-component Dark Matter | 50 pages, 16 figures | null | null | HIP-2020-35/TH, IIPDM-20 | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We study a $Z_2 \times Z'_2$ symmetric 3-Higgs Doublet Model (3HDM), wherein
two of the doublets are inert and one is active (thus denoted in literature as
I(2+1)HDM), yielding a two-component Dark Matter (DM) sector. The two DM
candidates emerge as the lightest scalar component of a different inert
doublet, each with a different odd discrete parity, and cooperate to achieve
the correct relic density. When a sufficient mass difference exists between the
two DM candidates, it is possible to test the presence of both in present
and/or forthcoming facilities, as the corresponding masses are typically at the
electroweak scale. Specifically, the light DM component can be probed by the
nuclear recoil energy in direct detection experiments while the heavy DM
component appears through the photon flux in indirect detection experiments. In
fact, the DM mass sensitivity that the two experimental set-ups can achieve
should be adequate to establish the presence of two different DM signals. This
result has been obtained in the presence of a thorough theoretical analysis of
the stability conditions of the vacuum structure emerging from our I(2+1)HDM
construct, ensuring that the model configurations adopted are physical, and of
up-to-date constraints coming from data collected by both space and ground
experiments, ensuring that the coupling and mass spectra investigated are
viable phenomenologically.
| [
{
"created": "Mon, 21 Dec 2020 19:00:06 GMT",
"version": "v1"
}
] | 2020-12-23 | [
[
"Hernandez-Sanchez",
"J.",
""
],
[
"Keus",
"V.",
""
],
[
"Moretti",
"S.",
""
],
[
"Rojas-Ciofalo",
"D.",
""
],
[
"Sokolowska",
"D.",
""
]
] | We study a $Z_2 \times Z'_2$ symmetric 3-Higgs Doublet Model (3HDM), wherein two of the doublets are inert and one is active (thus denoted in literature as I(2+1)HDM), yielding a two-component Dark Matter (DM) sector. The two DM candidates emerge as the lightest scalar component of a different inert doublet, each with a different odd discrete parity, and cooperate to achieve the correct relic density. When a sufficient mass difference exists between the two DM candidates, it is possible to test the presence of both in present and/or forthcoming facilities, as the corresponding masses are typically at the electroweak scale. Specifically, the light DM component can be probed by the nuclear recoil energy in direct detection experiments while the heavy DM component appears through the photon flux in indirect detection experiments. In fact, the DM mass sensitivity that the two experimental set-ups can achieve should be adequate to establish the presence of two different DM signals. This result has been obtained in the presence of a thorough theoretical analysis of the stability conditions of the vacuum structure emerging from our I(2+1)HDM construct, ensuring that the model configurations adopted are physical, and of up-to-date constraints coming from data collected by both space and ground experiments, ensuring that the coupling and mass spectra investigated are viable phenomenologically. |
hep-ph/9411409 | Peigne | R.Baier, Yu.L.Dokshitzer, S.Peign\'e, D.Schiff | Induced Gluon Radiation in a QCD Medium | 13 pages, 3 included figures, latex file | Phys.Lett. B345 (1995) 277-286 | 10.1016/0370-2693(94)01617-L | LPTHE-Orsay 94-98, LU TP 94-21, BI-TP 94-57 | hep-ph | null | Soft gluon radiation induced by multiple scattering of a fast quark or gluon
propagating through QCD matter is discussed. After revisiting the
Landau-Pomeranchuk-Migdal effect in QED we show that large formation times of
bremsstrahlung quanta determine the QCD radiation intensity (in analogy to QED)
and derive the gluon energy spectrum. Coherent suppression takes place as
compared to the Bethe-Heitler situation of independent emissions. As a result
the energy loss of fast partons in a QCD medium depends on the incident energy
$E$ similarly to QED, $-dE/dz \propto \sqrt{E}$.
| [
{
"created": "Mon, 28 Nov 1994 18:14:58 GMT",
"version": "v1"
},
{
"created": "Wed, 30 Nov 1994 16:00:00 GMT",
"version": "v2"
}
] | 2009-10-28 | [
[
"Baier",
"R.",
""
],
[
"Dokshitzer",
"Yu. L.",
""
],
[
"Peigné",
"S.",
""
],
[
"Schiff",
"D.",
""
]
] | Soft gluon radiation induced by multiple scattering of a fast quark or gluon propagating through QCD matter is discussed. After revisiting the Landau-Pomeranchuk-Migdal effect in QED we show that large formation times of bremsstrahlung quanta determine the QCD radiation intensity (in analogy to QED) and derive the gluon energy spectrum. Coherent suppression takes place as compared to the Bethe-Heitler situation of independent emissions. As a result the energy loss of fast partons in a QCD medium depends on the incident energy $E$ similarly to QED, $-dE/dz \propto \sqrt{E}$. |
hep-ph/9612218 | C. S. Kim | C.S. Kim (KEK, Japan and Yonsei University, Korea) | Associate $J/\psi + \gamma$ Production: A Clean Probe of Unpolarized and
Polarized Gluon Densities | 25 pages, LaTeX. Lecture given at NuSS96 (August 1996) | null | null | KEK-TH-502 | hep-ph | null | Color-octet contributions to the associate $J/\psi+\gamma$ production are
found to be negligible, compared to the ordinary color-singlet contribution.
Within the color-singlet model the $J/\psi+\gamma$ production in the leading
order is possible only through gluon-gluon fusion process. Therefore, the
associate $J/\psi+\gamma$ production remains to be useful as a clean channel to
probe the unpolarized and polarized gluon distribution inside proton (and
photon), and to study heavy quarkonia production mechanism. We discuss in
detail the associate production of $J/\psi+\gamma$ at $p \overline{p}$ (or
$pp$) and $ep$ colliders. By requiring the $J/\psi$ to decay into an $e^+e^-$
or $\mu^+ \mu^-$ pair, we end up with an exceptionally clean final state. This
process can therefore serve as a very clean probe of the gluon densities inside
the proton as well as the photon. Numerical results are presented for the
TEVATRON $p \overline{p}$ and HERA $ep$ colliders. This same mechanism can be
used to probe the polarized gluon content of the proton in polarized $p + p
(\bar p)$ collisions. We study in detail $J/\psi + \gamma$ production at both
polarized fixed target and polarized collider energies for RHIC.
| [
{
"created": "Sun, 1 Dec 1996 14:46:45 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Kim",
"C. S.",
"",
"KEK, Japan and Yonsei University, Korea"
]
] | Color-octet contributions to the associate $J/\psi+\gamma$ production are found to be negligible, compared to the ordinary color-singlet contribution. Within the color-singlet model the $J/\psi+\gamma$ production in the leading order is possible only through gluon-gluon fusion process. Therefore, the associate $J/\psi+\gamma$ production remains to be useful as a clean channel to probe the unpolarized and polarized gluon distribution inside proton (and photon), and to study heavy quarkonia production mechanism. We discuss in detail the associate production of $J/\psi+\gamma$ at $p \overline{p}$ (or $pp$) and $ep$ colliders. By requiring the $J/\psi$ to decay into an $e^+e^-$ or $\mu^+ \mu^-$ pair, we end up with an exceptionally clean final state. This process can therefore serve as a very clean probe of the gluon densities inside the proton as well as the photon. Numerical results are presented for the TEVATRON $p \overline{p}$ and HERA $ep$ colliders. This same mechanism can be used to probe the polarized gluon content of the proton in polarized $p + p (\bar p)$ collisions. We study in detail $J/\psi + \gamma$ production at both polarized fixed target and polarized collider energies for RHIC. |
hep-ph/9512322 | Stefan Groote | J.G. K"orner | Lambda_b-Polarization from its Inclusive Semileptonic Decay | Lecture given at the conference "Production and Decay of Hyperons,
Charm and Beauty Hadrons", Strassbourg, France, September 5-8, 1995; to
appear in the Proceedings of this conference; 9 pages, LaTeX, 3 figures are
included in uuencoded PostScript format; a new reference is added | Nucl.Phys.Proc.Suppl.50:130-134,1996 | 10.1016/0920-5632(96)00379-9 | MZ-TH/95-33 | hep-ph | null | We discuss the Lambda_b-polarization of the bottom baryon Lambda_b in its
production and in its decay. Standard Model predictions for b-quark
polarization on the Z-peak are reviewed, including beam-quark orientation
effects and O(as) radiative corrections to the polarization. The b-quark
polarization is expected to be handed over to the Lambda_b into which it
fragments with a high degree of efficiency. We present several spin-momentum
correlation measures of the spin of the \Lambda_b with the momenta of its decay
products in its inclusive semileptonic decay. We estimate the strengths of the
spin-momentum correlations in the Free Quark Decay (FQD) model and find that
some of the measures provide good or very good analyzing power for measuring
the polarization of the Lambda_b.
| [
{
"created": "Fri, 15 Dec 1995 11:09:45 GMT",
"version": "v1"
},
{
"created": "Tue, 19 Dec 1995 17:26:32 GMT",
"version": "v2"
}
] | 2011-01-25 | [
[
"K\"orner",
"J. G.",
""
]
] | We discuss the Lambda_b-polarization of the bottom baryon Lambda_b in its production and in its decay. Standard Model predictions for b-quark polarization on the Z-peak are reviewed, including beam-quark orientation effects and O(as) radiative corrections to the polarization. The b-quark polarization is expected to be handed over to the Lambda_b into which it fragments with a high degree of efficiency. We present several spin-momentum correlation measures of the spin of the \Lambda_b with the momenta of its decay products in its inclusive semileptonic decay. We estimate the strengths of the spin-momentum correlations in the Free Quark Decay (FQD) model and find that some of the measures provide good or very good analyzing power for measuring the polarization of the Lambda_b. |
hep-ph/0005157 | Spencer Klein | Spencer R. Klein, Joakim Nystrand and Ramona Vogt | Photoproduction of top in peripheral heavy ion collisions | kinematics clarified (results unchanged); to appear in Eur. Phys. J.
C 13 pages including 2 figures kinematics section clarified (results
unchanged) | Eur.Phys.J.C21:563-566,2001 | 10.1007/s100520100739 | LBNL-45743 | hep-ph nucl-th | null | In relativistic heavy ion collisions, top quarks can be produced by
photon-gluon fusion when a photon from the Weizs\"acker-Williams virtual photon
field of one nucleus interacts with a gluon in the other nucleus.
Photoproduction with heavy ions at the Large Hadron Collider (LHC) will be the
first accessible non-hadronic top production channel. We calculate the $t \bar
t$ photoproduction cross sections, pair mass and top quark rapidity
distributions in peripheral heavy ion collisions. The cross sections are
sensitive to the top quark charge and the large-$Q^2$ gluon distribution in the
nucleus. We find a cross section of 94 pb in calcium-calcium collisions,
leading to 190 pairs in a one month ($10^6$ sec) LHC run. We also find $p$Pb
and $p$Ca cross sections of 5.8 and 3.4 pb respectively, resulting in 6 and 34
$t\bar t$ pairs per month.
| [
{
"created": "Tue, 16 May 2000 21:45:15 GMT",
"version": "v1"
},
{
"created": "Fri, 11 Aug 2000 22:39:55 GMT",
"version": "v2"
},
{
"created": "Mon, 9 Jul 2001 20:28:17 GMT",
"version": "v3"
}
] | 2009-01-07 | [
[
"Klein",
"Spencer R.",
""
],
[
"Nystrand",
"Joakim",
""
],
[
"Vogt",
"Ramona",
""
]
] | In relativistic heavy ion collisions, top quarks can be produced by photon-gluon fusion when a photon from the Weizs\"acker-Williams virtual photon field of one nucleus interacts with a gluon in the other nucleus. Photoproduction with heavy ions at the Large Hadron Collider (LHC) will be the first accessible non-hadronic top production channel. We calculate the $t \bar t$ photoproduction cross sections, pair mass and top quark rapidity distributions in peripheral heavy ion collisions. The cross sections are sensitive to the top quark charge and the large-$Q^2$ gluon distribution in the nucleus. We find a cross section of 94 pb in calcium-calcium collisions, leading to 190 pairs in a one month ($10^6$ sec) LHC run. We also find $p$Pb and $p$Ca cross sections of 5.8 and 3.4 pb respectively, resulting in 6 and 34 $t\bar t$ pairs per month. |
1207.7355 | Michael Trott | Jos\'e R. Espinosa, Christophe Grojean, Ver\'onica Sanz and Michael
Trott | NSUSY fits | 41 pages, 13 figures. v3: final JHEP version, b to s gamma updated to
latest data and typos corrected | JHEP12(2012)077 | 10.1007/JHEP12(2012)077 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We perform a global fit to Higgs signal-strength data in the context of light
stops in Natural SUSY. In this case, the Wilson coefficients of the higher
dimensional operators mediating g g -> h and h -> \gamma \gamma, given by c_g,
c_\gamma, are related by c_g = 3 (1 + 3 \alpha_s/(2 \pi)) c_\gamma/8. We
examine this predictive scenario in detail, combining Higgs signal-strength
constraints with recent precision measurements of m_W, b-> s \gamma constraints
and direct collider bounds on weak scale SUSY, finding regions of parameter
space that are consistent with all of these constraints. However it is
challenging for the allowed parameter space to reproduce the observed Higgs
mass value with sub-TeV stops. We discuss some of the direct stop discovery
prospects and show how global Higgs fits can be used to exclude light stop
parameter space difficult to probe by direct collider searches. We determine
the current status of such indirect exclusions and estimate their reach by the
end of the 8 TeV LHC run.
| [
{
"created": "Tue, 31 Jul 2012 19:54:38 GMT",
"version": "v1"
},
{
"created": "Mon, 22 Oct 2012 20:21:34 GMT",
"version": "v2"
},
{
"created": "Sun, 16 Dec 2012 20:47:27 GMT",
"version": "v3"
}
] | 2015-06-05 | [
[
"Espinosa",
"José R.",
""
],
[
"Grojean",
"Christophe",
""
],
[
"Sanz",
"Verónica",
""
],
[
"Trott",
"Michael",
""
]
] | We perform a global fit to Higgs signal-strength data in the context of light stops in Natural SUSY. In this case, the Wilson coefficients of the higher dimensional operators mediating g g -> h and h -> \gamma \gamma, given by c_g, c_\gamma, are related by c_g = 3 (1 + 3 \alpha_s/(2 \pi)) c_\gamma/8. We examine this predictive scenario in detail, combining Higgs signal-strength constraints with recent precision measurements of m_W, b-> s \gamma constraints and direct collider bounds on weak scale SUSY, finding regions of parameter space that are consistent with all of these constraints. However it is challenging for the allowed parameter space to reproduce the observed Higgs mass value with sub-TeV stops. We discuss some of the direct stop discovery prospects and show how global Higgs fits can be used to exclude light stop parameter space difficult to probe by direct collider searches. We determine the current status of such indirect exclusions and estimate their reach by the end of the 8 TeV LHC run. |
1506.07110 | James Alexander Osborne | Yang Bai and James Osborne | Chromo-Rayleigh Interactions of Dark Matter | 21 pages, 9 figures | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | For a wide range of models, dark matter can interact with QCD gluons via
chromo-Rayleigh interactions. We point out that the Large Hadron Collider
(LHC), as a gluon machine, provides a superb probe of such interactions. In
this paper, we introduce simplified models to UV-complete two effective dark
matter chromo-Rayleigh interactions and identify the corresponding collider
signatures, including four jets or a pair of di-jet resonances plus missing
transverse energy. After performing collider studies for both the 8 TeV and 14
TeV LHC, we find that the LHC can be more sensitive to dark matter
chromo-Rayleigh interactions than direct detection experiments and thus
provides the best opportunity for future discovery of this class of models.
| [
{
"created": "Tue, 23 Jun 2015 17:54:53 GMT",
"version": "v1"
}
] | 2015-07-01 | [
[
"Bai",
"Yang",
""
],
[
"Osborne",
"James",
""
]
] | For a wide range of models, dark matter can interact with QCD gluons via chromo-Rayleigh interactions. We point out that the Large Hadron Collider (LHC), as a gluon machine, provides a superb probe of such interactions. In this paper, we introduce simplified models to UV-complete two effective dark matter chromo-Rayleigh interactions and identify the corresponding collider signatures, including four jets or a pair of di-jet resonances plus missing transverse energy. After performing collider studies for both the 8 TeV and 14 TeV LHC, we find that the LHC can be more sensitive to dark matter chromo-Rayleigh interactions than direct detection experiments and thus provides the best opportunity for future discovery of this class of models. |
2303.05599 | Dana Avramescu | Dana Avramescu, Virgil B\u{a}ran, Vincenzo Greco, Andreas Ipp, David.
I. M\"uller, Marco Ruggieri | Simulating jets and heavy quarks in the Glasma using the colored
particle-in-cell method | 30 pages, 15 figures; v2 added references, fixed typos v3 published
in PRD | Phys. Rev. D 107 (2023), 114021 | 10.1103/PhysRevD.107.114021 | null | hep-ph hep-lat nucl-th | http://creativecommons.org/licenses/by/4.0/ | We explore the impact of strong classical color fields, which occur in the
earliest stages of heavy-ion collisions and are known as the Glasma, on the
classical transport of hard probes, namely heavy quarks and jets. To achieve
this, we simulate SU(3) color fields using classical real-time lattice gauge
theory and couple them to an ensemble of test particles whose dynamics are
described by Wong's equations. We provide an overview of how classical color
algebras are constructed and introduce a method to generate random classical
SU(3) color charges. We extensively test our numerical particle solver in the
limits of infinitely massive heavy quarks and ultra-relativistic light-like
jets and obtain excellent quantitative agreement with previous studies. Going
towards realistic masses and initial moment, we extract longitudinal and
transverse momentum broadening for heavy quarks and jets. The resulting
accumulated momenta and the anisotropy of these dynamical hard probes exhibit
deviations from limiting scenarios, showing that the full dynamics have a
significant effect.
| [
{
"created": "Thu, 9 Mar 2023 21:49:20 GMT",
"version": "v1"
},
{
"created": "Tue, 11 Apr 2023 07:44:06 GMT",
"version": "v2"
},
{
"created": "Sun, 16 Jul 2023 10:49:49 GMT",
"version": "v3"
}
] | 2023-07-18 | [
[
"Avramescu",
"Dana",
""
],
[
"Băran",
"Virgil",
""
],
[
"Greco",
"Vincenzo",
""
],
[
"Ipp",
"Andreas",
""
],
[
"Müller",
"David. I.",
""
],
[
"Ruggieri",
"Marco",
""
]
] | We explore the impact of strong classical color fields, which occur in the earliest stages of heavy-ion collisions and are known as the Glasma, on the classical transport of hard probes, namely heavy quarks and jets. To achieve this, we simulate SU(3) color fields using classical real-time lattice gauge theory and couple them to an ensemble of test particles whose dynamics are described by Wong's equations. We provide an overview of how classical color algebras are constructed and introduce a method to generate random classical SU(3) color charges. We extensively test our numerical particle solver in the limits of infinitely massive heavy quarks and ultra-relativistic light-like jets and obtain excellent quantitative agreement with previous studies. Going towards realistic masses and initial moment, we extract longitudinal and transverse momentum broadening for heavy quarks and jets. The resulting accumulated momenta and the anisotropy of these dynamical hard probes exhibit deviations from limiting scenarios, showing that the full dynamics have a significant effect. |
1306.6725 | Jialun Ping | Chengrong Deng, Jialun Ping, Youchang Yang, and Fan Wang | Baryonia and near-threshold enhancements | 8 pages, 3 figures | null | 10.1103/PhysRevD.88.074007 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The baryon-antibaryon spectrum consisting of strange, charm and bottom quarks
is studied in the color flux-tube model with a multi-body confinement
interaction. Numerical results indicate that many low-spin baryon-antibaryon
states can form compact hexaquark states and are stable against the decay into
a baryon and an antibaryon. The multi-body confinement interaction as a binding
mechanism plays an important role in the formation of the states. They can be
searched in the $e^+e^-$ annihilation and charmonium or bottomonium decay if
they really exist. The newly reported states, X(1835), X(2370), Y(2175),
Y(4360) and Y_b(10890), may be interpreted as $N\bar{N}$, $\Delta\bar{\Delta}$,
$\Lambda\bar{\Lambda}$, $\Lambda_c\bar{\Lambda}_c$ and
$\Lambda_b\bar{\Lambda}_b$ states, respectively.
| [
{
"created": "Fri, 28 Jun 2013 06:20:53 GMT",
"version": "v1"
}
] | 2015-06-16 | [
[
"Deng",
"Chengrong",
""
],
[
"Ping",
"Jialun",
""
],
[
"Yang",
"Youchang",
""
],
[
"Wang",
"Fan",
""
]
] | The baryon-antibaryon spectrum consisting of strange, charm and bottom quarks is studied in the color flux-tube model with a multi-body confinement interaction. Numerical results indicate that many low-spin baryon-antibaryon states can form compact hexaquark states and are stable against the decay into a baryon and an antibaryon. The multi-body confinement interaction as a binding mechanism plays an important role in the formation of the states. They can be searched in the $e^+e^-$ annihilation and charmonium or bottomonium decay if they really exist. The newly reported states, X(1835), X(2370), Y(2175), Y(4360) and Y_b(10890), may be interpreted as $N\bar{N}$, $\Delta\bar{\Delta}$, $\Lambda\bar{\Lambda}$, $\Lambda_c\bar{\Lambda}_c$ and $\Lambda_b\bar{\Lambda}_b$ states, respectively. |
hep-ph/0405263 | Willy Van Neerven wvn | V. Ravindran, J. Smith, W.L. van Neerven | NNLO Corrections to the Higgs Production Cross Section | 6 pages, 5 figures, 7th DESY Workshop on Elementary Particle Theory,
Loop and Legs in Quantum Field Theory,Zinnowitz, Germany, April 25-30, 2004 | null | 10.1016/j.nuclphysbps.2004.09.007 | null | hep-ph | null | We discuss the next-to-next-to-leading order (NNLO) corrections to the total
cross section for (pseudo-) scalar Higgs boson production. The computation is
carried out in the effective Lagrangian approach which emerges from the
standard model by taking the limit $m_t \to \infty$ where $m_t$ denotes the
mass of the top quark.
| [
{
"created": "Wed, 26 May 2004 15:07:04 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Ravindran",
"V.",
""
],
[
"Smith",
"J.",
""
],
[
"van Neerven",
"W. L.",
""
]
] | We discuss the next-to-next-to-leading order (NNLO) corrections to the total cross section for (pseudo-) scalar Higgs boson production. The computation is carried out in the effective Lagrangian approach which emerges from the standard model by taking the limit $m_t \to \infty$ where $m_t$ denotes the mass of the top quark. |
hep-ph/0306169 | Graeme Watt | G. Watt, A.D. Martin, M.G. Ryskin | Unintegrated parton distributions and inclusive jet production at HERA | 32 pages, 11 figures. Version to appear in Eur. Phys. J. C | Eur.Phys.J.C31:73-89,2003 | 10.1140/epjc/s2003-01320-4 | IPPP-03-29, DCPT-03-58 | hep-ph | null | We describe how unintegrated parton distributions can be calculated from
conventional integrated distributions. We extend and improve the 'last-step'
evolution approach, and explain why doubly-unintegrated parton distributions
are necessary. We generalise k_t-factorisation to (z,k_t)-factorisation. We
apply the formalism to inclusive jet production in deep-inelastic scattering,
mainly at leading-order, but we also study the extension to next-to-leading
order. We compare the predictions with recent HERA data.
| [
{
"created": "Wed, 18 Jun 2003 19:55:57 GMT",
"version": "v1"
},
{
"created": "Tue, 9 Sep 2003 15:59:06 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"Watt",
"G.",
""
],
[
"Martin",
"A. D.",
""
],
[
"Ryskin",
"M. G.",
""
]
] | We describe how unintegrated parton distributions can be calculated from conventional integrated distributions. We extend and improve the 'last-step' evolution approach, and explain why doubly-unintegrated parton distributions are necessary. We generalise k_t-factorisation to (z,k_t)-factorisation. We apply the formalism to inclusive jet production in deep-inelastic scattering, mainly at leading-order, but we also study the extension to next-to-leading order. We compare the predictions with recent HERA data. |
1105.3734 | Christopher McCabe | Mads T. Frandsen, Felix Kahlhoefer, John March-Russell, Christopher
McCabe, Matthew McCullough, Kai Schmidt-Hoberg | On the DAMA and CoGeNT Modulations | 5 pages, 1 figure. v2 updated refs and CoGeNT data, confidence
regions now shown at 95% | Phys.Rev.D84:041301,2011 | 10.1103/PhysRevD.84.041301 | OUTP-11-40-P | hep-ph astro-ph.HE hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | DAMA observes an annual modulation in their event rate, as might be expected
from dark matter scatterings, while CoGeNT has reported evidence for a similar
modulation. The simplest interpretation of these findings in terms of dark
matter-nucleus scatterings is excluded by other direct detection experiments.
We consider the robustness of these exclusions with respect to assumptions
regarding the scattering and find that isospin-violating inelastic dark matter
helps alleviate this tension and allows marginal compatibility between
experiments. Isospin-violation can significantly weaken the XENON constraints,
while inelasticity enhances the annual modulation fraction of the signal,
bringing the CoGeNT and CDMS results into better agreement.
| [
{
"created": "Wed, 18 May 2011 20:02:08 GMT",
"version": "v1"
},
{
"created": "Wed, 6 Jul 2011 16:12:14 GMT",
"version": "v2"
}
] | 2011-09-15 | [
[
"Frandsen",
"Mads T.",
""
],
[
"Kahlhoefer",
"Felix",
""
],
[
"March-Russell",
"John",
""
],
[
"McCabe",
"Christopher",
""
],
[
"McCullough",
"Matthew",
""
],
[
"Schmidt-Hoberg",
"Kai",
""
]
] | DAMA observes an annual modulation in their event rate, as might be expected from dark matter scatterings, while CoGeNT has reported evidence for a similar modulation. The simplest interpretation of these findings in terms of dark matter-nucleus scatterings is excluded by other direct detection experiments. We consider the robustness of these exclusions with respect to assumptions regarding the scattering and find that isospin-violating inelastic dark matter helps alleviate this tension and allows marginal compatibility between experiments. Isospin-violation can significantly weaken the XENON constraints, while inelasticity enhances the annual modulation fraction of the signal, bringing the CoGeNT and CDMS results into better agreement. |
1304.5437 | Marcin Badziak | Marcin Badziak, Marek Olechowski, Stefan Pokorski | New Regions in the NMSSM with a 125 GeV Higgs | 19 pages, 5 figures, references added, version to be published | JHEP 06 (2013) 043 | 10.1007/JHEP06(2013)043 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | It is pointed out that mixing effects in the CP-even scalar sector of the
NMSSM can give 6-8 GeV correction to the SM-like Higgs mass in moderate or
large $\tan\beta$ regions with a small value of the singlet-higgs-higgs
superfields coupling $\lambda\sim\mathcal{O}(0.1)$. This effect comes mainly
from the mixing of the SM-like Higgs with lighter singlet. In the same
parameter range, the mixing of the heavy doublet Higgs with the singlet may
strongly modify the couplings of the singlet-like and the 125 GeV scalars.
Firstly, the LEP bounds on a light singlet can be evaded for a large range of
its masses. Secondly, the decay rates of both scalars can show a variety of
interesting patterns, depending on the lightest scalar mass. In particular, a
striking signature of this mechanism can be a light scalar with strongly
suppressed (enhanced) branching ratios to $b\bar{b}$ ($gg$, $c\bar{c}$,
$\gamma\gamma$) as compared to the SM Higgs with the same mass. The
$\gamma\gamma$ decay channel is particularly promising for the search of such a
scalar at the LHC. The 125 GeV scalar can, thus, be accommodated with
substantially smaller than in the MSSM radiative corrections from the stop
loops (and consequently, with lighter stops) also for moderate or large
$\tan\beta$, with the mixing effects replacing the standard NMSSM mechanism of
increasing the tree level Higgs mass in the low $\tan\beta$ and large $\lambda$
regime, and with clear experimental signatures of such a mechanism.
| [
{
"created": "Fri, 19 Apr 2013 14:47:43 GMT",
"version": "v1"
},
{
"created": "Mon, 10 Jun 2013 14:24:16 GMT",
"version": "v2"
}
] | 2013-06-14 | [
[
"Badziak",
"Marcin",
""
],
[
"Olechowski",
"Marek",
""
],
[
"Pokorski",
"Stefan",
""
]
] | It is pointed out that mixing effects in the CP-even scalar sector of the NMSSM can give 6-8 GeV correction to the SM-like Higgs mass in moderate or large $\tan\beta$ regions with a small value of the singlet-higgs-higgs superfields coupling $\lambda\sim\mathcal{O}(0.1)$. This effect comes mainly from the mixing of the SM-like Higgs with lighter singlet. In the same parameter range, the mixing of the heavy doublet Higgs with the singlet may strongly modify the couplings of the singlet-like and the 125 GeV scalars. Firstly, the LEP bounds on a light singlet can be evaded for a large range of its masses. Secondly, the decay rates of both scalars can show a variety of interesting patterns, depending on the lightest scalar mass. In particular, a striking signature of this mechanism can be a light scalar with strongly suppressed (enhanced) branching ratios to $b\bar{b}$ ($gg$, $c\bar{c}$, $\gamma\gamma$) as compared to the SM Higgs with the same mass. The $\gamma\gamma$ decay channel is particularly promising for the search of such a scalar at the LHC. The 125 GeV scalar can, thus, be accommodated with substantially smaller than in the MSSM radiative corrections from the stop loops (and consequently, with lighter stops) also for moderate or large $\tan\beta$, with the mixing effects replacing the standard NMSSM mechanism of increasing the tree level Higgs mass in the low $\tan\beta$ and large $\lambda$ regime, and with clear experimental signatures of such a mechanism. |
hep-ph/0310306 | Alexander Kalloniatis | A.C. Kalloniatis (CSSM, Adelaide), S.N. Nedelko (JINR, Dubna and
ITPIII, Erlangen) | Quark determinant in domain-like gluon fields | Contribution to the International Workshop on QCD: QCD@Work 2003 -
Conversano (Italy) 14-18 June 2003 (eConf C030614) | null | null | null | hep-ph | null | We address the computation of the determinant for the Dirac operator
corresponding to a quark propagating in a background gluon field of the
following type: the gauge field is covariantly constant and self-dual inside a
hypersphere and with quark fields satisfying bag-like (chiral-violating)
boundary conditions at the surface of the hypersphere. We find that the parity
odd part of the logarithm of the determinant corresponds to the Abelian
anomaly. However the parity even part also depends on the chiral angle
associated with the boundary. This unexpected dependence is discussed.
| [
{
"created": "Tue, 28 Oct 2003 06:57:59 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Kalloniatis",
"A. C.",
"",
"CSSM, Adelaide"
],
[
"Nedelko",
"S. N.",
"",
"JINR, Dubna and\n ITPIII, Erlangen"
]
] | We address the computation of the determinant for the Dirac operator corresponding to a quark propagating in a background gluon field of the following type: the gauge field is covariantly constant and self-dual inside a hypersphere and with quark fields satisfying bag-like (chiral-violating) boundary conditions at the surface of the hypersphere. We find that the parity odd part of the logarithm of the determinant corresponds to the Abelian anomaly. However the parity even part also depends on the chiral angle associated with the boundary. This unexpected dependence is discussed. |
hep-ph/0607170 | Fuminobu Takahashi | Motoi Endo, Masahiro Kawasaki, Fuminobu Takahashi, T. T. Yanagida | Inflaton Decay through Supergravity Effects | 18 pages, 4 figures. v2: a version published in PLB | Phys.Lett. B642 (2006) 518-524 | 10.1016/j.physletb.2006.09.044 | DESY 06-106 | hep-ph astro-ph hep-th | null | We point out that supergravity effects enable the inflaton to decay into all
matter fields, including the visible and the supersymmetry breaking sectors,
once the inflaton acquires a non-vanishing vacuum expectation value. The new
decay processes have great impacts on cosmology; the reheating temperature is
bounded below; the gravitinos are produced by the inflaton decay in a broad
class of the dynamical supersymmetry breaking models. We derive the bounds on
the inflaton mass and the vacuum expectation value, which severely constrain
high-scale inflations such as the hybrid and chaotic inflation models.
| [
{
"created": "Fri, 14 Jul 2006 13:25:01 GMT",
"version": "v1"
},
{
"created": "Wed, 8 Nov 2006 10:03:42 GMT",
"version": "v2"
}
] | 2009-11-11 | [
[
"Endo",
"Motoi",
""
],
[
"Kawasaki",
"Masahiro",
""
],
[
"Takahashi",
"Fuminobu",
""
],
[
"Yanagida",
"T. T.",
""
]
] | We point out that supergravity effects enable the inflaton to decay into all matter fields, including the visible and the supersymmetry breaking sectors, once the inflaton acquires a non-vanishing vacuum expectation value. The new decay processes have great impacts on cosmology; the reheating temperature is bounded below; the gravitinos are produced by the inflaton decay in a broad class of the dynamical supersymmetry breaking models. We derive the bounds on the inflaton mass and the vacuum expectation value, which severely constrain high-scale inflations such as the hybrid and chaotic inflation models. |
1004.0962 | Stefano Forte | Federico Demartin, Stefano Forte, Elisa Mariani, Juan Rojo and
Alessandro Vicini | The impact of PDF and alphas uncertainties on Higgs Production in gluon
fusion at hadron colliders | 29 pages, 13 figures | Phys.Rev.D82:014002,2010 | 10.1103/PhysRevD.82.014002 | IFUM-956-FT | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a systematic study of uncertainties due to parton distributions
and the strong coupling on the gluon-fusion production cross section of the
Standard Model Higgs at the Tevatron and LHC colliders. We compare procedures
and results when three recent sets of PDFs are used, CTEQ6.6, MSTW08 and
NNPDF1.2, and we discuss specifically the way PDF and strong coupling
uncertainties are combined. We find that results obtained from different PDF
sets are in reasonable agreement if a common value of the strong coupling is
adopted. We show that the addition in quadrature of PDF and alphas
uncertainties provides an adequate approximation to the full result with exact
error propagation. We discuss a simple recipe to determine a conservative
PDF+alphas uncertainty from available global parton sets, and we use it to
estimate this uncertainty on the given process to be about 10% at the Tevatron
and 5% at the LHC for a light Higgs.
| [
{
"created": "Tue, 6 Apr 2010 20:10:23 GMT",
"version": "v1"
}
] | 2014-11-20 | [
[
"Demartin",
"Federico",
""
],
[
"Forte",
"Stefano",
""
],
[
"Mariani",
"Elisa",
""
],
[
"Rojo",
"Juan",
""
],
[
"Vicini",
"Alessandro",
""
]
] | We present a systematic study of uncertainties due to parton distributions and the strong coupling on the gluon-fusion production cross section of the Standard Model Higgs at the Tevatron and LHC colliders. We compare procedures and results when three recent sets of PDFs are used, CTEQ6.6, MSTW08 and NNPDF1.2, and we discuss specifically the way PDF and strong coupling uncertainties are combined. We find that results obtained from different PDF sets are in reasonable agreement if a common value of the strong coupling is adopted. We show that the addition in quadrature of PDF and alphas uncertainties provides an adequate approximation to the full result with exact error propagation. We discuss a simple recipe to determine a conservative PDF+alphas uncertainty from available global parton sets, and we use it to estimate this uncertainty on the given process to be about 10% at the Tevatron and 5% at the LHC for a light Higgs. |
2010.11987 | Evgenij Martynov | N. Bence, A. Lengyel, Z. Tarics, E. Martynov, G. Tersimonov | Froissaron and Maximal Odderon with spin-flip in $pp$ and $\bar pp$ high
energy elastic scattering | 10 pages, 7 figures. Typos, one reference and minor text corrections.
One figure splited for two. Results and conclusions unchanged | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We assume that the scattering amplitude is represented by Froissaron, Maximal
Odderon as well as by standard Regge poles. From the fit to the data of $pp$
and $\bar pp$ scattering at high energy and not too large momentum transfers we
found that this model taking into account the spin is available to describe not
only the differential, total cross section and $\rho$, but also the existing
experimental data on polarization.
| [
{
"created": "Thu, 22 Oct 2020 18:59:28 GMT",
"version": "v1"
},
{
"created": "Fri, 6 Nov 2020 16:10:06 GMT",
"version": "v2"
}
] | 2020-11-09 | [
[
"Bence",
"N.",
""
],
[
"Lengyel",
"A.",
""
],
[
"Tarics",
"Z.",
""
],
[
"Martynov",
"E.",
""
],
[
"Tersimonov",
"G.",
""
]
] | We assume that the scattering amplitude is represented by Froissaron, Maximal Odderon as well as by standard Regge poles. From the fit to the data of $pp$ and $\bar pp$ scattering at high energy and not too large momentum transfers we found that this model taking into account the spin is available to describe not only the differential, total cross section and $\rho$, but also the existing experimental data on polarization. |
hep-ph/9311242 | Paul B. Mackenzie | Paul B. Mackenzie | Status of Lattice QCD | 20 pages, 8 embedded figures, uuencoded, 2 missing figures. (Talk
presented at the Lepton-Photon Symposium, Cornell University, Aug. 10-15,
1993.) | null | 10.1063/1.454670 | null | hep-ph hep-lat | null | Significant progress has recently been achieved in the lattice gauge theory
calculations required for extracting the fundamental parameters of the standard
model from experiment. Recent lattice determinations of such quantities as the
kaon $B$ parameter, the mass of the $b$ quark, and the strong coupling constant
have produced results and uncertainties as good or better than the best
conventional determinations. Many other calculations crucial to extracting the
fundamental parameters of the standard model from experimental data are
undergoing very active development. I review the status of such applications of
lattice QCD to standard model phenomenology, and discuss the prospects for the
near future.
| [
{
"created": "Mon, 8 Nov 1993 23:10:03 GMT",
"version": "v1"
}
] | 2015-06-25 | [
[
"Mackenzie",
"Paul B.",
""
]
] | Significant progress has recently been achieved in the lattice gauge theory calculations required for extracting the fundamental parameters of the standard model from experiment. Recent lattice determinations of such quantities as the kaon $B$ parameter, the mass of the $b$ quark, and the strong coupling constant have produced results and uncertainties as good or better than the best conventional determinations. Many other calculations crucial to extracting the fundamental parameters of the standard model from experimental data are undergoing very active development. I review the status of such applications of lattice QCD to standard model phenomenology, and discuss the prospects for the near future. |
2004.05354 | Sang Hui Im | Kyu Jung Bae, Sang Hui Im | Supersymmetric Clockwork Axion Model and Axino Dark Matter | 9 pages; v2: added comments about conditions to get the clockwork
mixing pattern in page 5, matches the published version | Phys. Rev. D 102, 015011 (2020) | 10.1103/PhysRevD.102.015011 | CTPU-PTC-20-08 | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Implications of supersymmetrizing the clockwork axions are studied.
Supersymmetry ensures that the saxions and axinos have the same pattern of the
coupling hierarchy as the clockwork axions. If we assume supersymmetry breaking
is universal over the clockwork sites, the coupling structure is preserved,
while the mass orderings of the saxions and axinos can differ depending on the
supersymmetry breaking scale. While the massive saxions and axions quickly
decay, the lightest axino can be stable and thus a dark matter candidate. The
relic abundance of the axino dark matter from thermal production is mostly
determined by decays of the heavier axinos in the normal mass ordering. This
exponentially enhances the thermal yield compared to the conventional axino
scenarios. Some cosmological issues are discussed.
| [
{
"created": "Sat, 11 Apr 2020 09:50:00 GMT",
"version": "v1"
},
{
"created": "Mon, 20 Jul 2020 11:03:57 GMT",
"version": "v2"
}
] | 2020-07-21 | [
[
"Bae",
"Kyu Jung",
""
],
[
"Im",
"Sang Hui",
""
]
] | Implications of supersymmetrizing the clockwork axions are studied. Supersymmetry ensures that the saxions and axinos have the same pattern of the coupling hierarchy as the clockwork axions. If we assume supersymmetry breaking is universal over the clockwork sites, the coupling structure is preserved, while the mass orderings of the saxions and axinos can differ depending on the supersymmetry breaking scale. While the massive saxions and axions quickly decay, the lightest axino can be stable and thus a dark matter candidate. The relic abundance of the axino dark matter from thermal production is mostly determined by decays of the heavier axinos in the normal mass ordering. This exponentially enhances the thermal yield compared to the conventional axino scenarios. Some cosmological issues are discussed. |
hep-ph/9602275 | Kevin Anderson | K.D. Anderson, D.A. Ross, M.G. Sotiropoulos | How to Run the Coupling in the Dipole Approach to the BFKL Equation | 10 pages, latex, 1 figure, included. LaTeX2e compatibility problems
fixed: no changes in contents | Phys.Lett. B380 (1996) 127-133 | 10.1016/0370-2693(96)00487-X | SHEP 96-06, February 1996 | hep-ph | null | We use the dipole expansion to provide a systematic way of including the
running coupling into the BFKL equation. In terms of a Borel representation, we
obtain an expression for the kernel of the BFKL equation.
| [
{
"created": "Mon, 12 Feb 1996 11:38:53 GMT",
"version": "v1"
},
{
"created": "Tue, 13 Feb 1996 19:48:53 GMT",
"version": "v2"
}
] | 2009-10-28 | [
[
"Anderson",
"K. D.",
""
],
[
"Ross",
"D. A.",
""
],
[
"Sotiropoulos",
"M. G.",
""
]
] | We use the dipole expansion to provide a systematic way of including the running coupling into the BFKL equation. In terms of a Borel representation, we obtain an expression for the kernel of the BFKL equation. |
hep-ph/0611115 | Giuseppe Marchesini | Giuseppe Marchesini | QCD Review | Plenary talk at 33rd International Conference on High-Energy Physics
(ICHEP 06), Moscow, Russia, July 26 - August 2, 2006 | Int.J.Mod.Phys.A22:5443-5452,2007 | 10.1142/S0217751X07038700 | null | hep-ph | null | This review is focused on QCD theoretical issues and their phenomenological
relevance specially for LHC. It is incomplete and mostly neglects the
phenomenology of long distance physics
| [
{
"created": "Thu, 9 Nov 2006 09:11:05 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Marchesini",
"Giuseppe",
""
]
] | This review is focused on QCD theoretical issues and their phenomenological relevance specially for LHC. It is incomplete and mostly neglects the phenomenology of long distance physics |
hep-ph/0208102 | Gilad Perez | Gilad Perez | Lepton Masses and Mixing in a Left-Right Symmetric Model with a
TeV-scale Gravity | 21 pages, 1 figure, references added, discussion on the
predictiveness of the model in the generic non-universal case added, to
appear in PRD | Phys.Rev. D67 (2003) 013009 | 10.1103/PhysRevD.67.013009 | null | hep-ph | null | We construct a left-right symmetric (LRS) model in five dimensions which
accounts naturally for the lepton flavor parameters. The fifth dimension is
described by an orbifold, S_1/Z_2 times Z'_2, with a typical size of order
TeV^{-1}. The fundamental scale is of order 25 TeV which implies that the gauge
hierarchy problem is ameliorated. In addition the LRS breaking scale is of
order few TeV which implies that interactions beyond those of the standard
model are accessible to near future experiments. Leptons of different
representations are localized around different orbifold fixed points. This
explains, through the Arkani-Hamed-Schmaltz mechanism, the smallness of the tau
mass compared to the electroweak breaking scale. An additional U(1) horizontal
symmetry, broken by small parameters, yields the hierarchy in the charged
lepton masses, strong suppression of the light neutrino masses and accounts for
the mixing parameters. The model yields several unique predictions. In
particular, the branching ratio for the lepton flavor violating process mu^-
--> e^+ e^- e^- is comparable with its present experimental sensitivity.
| [
{
"created": "Sat, 10 Aug 2002 10:04:08 GMT",
"version": "v1"
},
{
"created": "Sun, 10 Nov 2002 07:39:03 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Perez",
"Gilad",
""
]
] | We construct a left-right symmetric (LRS) model in five dimensions which accounts naturally for the lepton flavor parameters. The fifth dimension is described by an orbifold, S_1/Z_2 times Z'_2, with a typical size of order TeV^{-1}. The fundamental scale is of order 25 TeV which implies that the gauge hierarchy problem is ameliorated. In addition the LRS breaking scale is of order few TeV which implies that interactions beyond those of the standard model are accessible to near future experiments. Leptons of different representations are localized around different orbifold fixed points. This explains, through the Arkani-Hamed-Schmaltz mechanism, the smallness of the tau mass compared to the electroweak breaking scale. An additional U(1) horizontal symmetry, broken by small parameters, yields the hierarchy in the charged lepton masses, strong suppression of the light neutrino masses and accounts for the mixing parameters. The model yields several unique predictions. In particular, the branching ratio for the lepton flavor violating process mu^- --> e^+ e^- e^- is comparable with its present experimental sensitivity. |
hep-ph/9605275 | null | L. E. Gordon (ANL), J. K. Storrow (Manchester) | Prompt Photon Production in $\gamma \gamma$ Collisions and the Gluon
Content of the Photon | 19 pages, requires epsf.tex | Phys.Lett.B385:385-390,1996 | 10.1016/0370-2693(96)00877-5 | ANL-HEP-PR-96-32, MC-TH-96/15 | hep-ph | null | We calculate the cross section for inclusive prompt photon production in
$\gamma\gamma$ collisions, i.e. the reaction $e^+e^-\to \gamma \gamma \to
\gamma X$, in next-to-leading order QCD. We show that at LEP2 energies this
cross section is measurable and is sensitive to the gluon distribution of the
photon, $g^{\gamma}$, which is currently very poorly constrained by data.
| [
{
"created": "Fri, 10 May 1996 15:09:44 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"Gordon",
"L. E.",
"",
"ANL"
],
[
"Storrow",
"J. K.",
"",
"Manchester"
]
] | We calculate the cross section for inclusive prompt photon production in $\gamma\gamma$ collisions, i.e. the reaction $e^+e^-\to \gamma \gamma \to \gamma X$, in next-to-leading order QCD. We show that at LEP2 energies this cross section is measurable and is sensitive to the gluon distribution of the photon, $g^{\gamma}$, which is currently very poorly constrained by data. |
2102.07124 | George Lazarides Prof. | George Lazarides, Qaisar Shafi | Electroweak monopoles and magnetic dumbbells in grand unified theories | 5 pages, version published in Phys. Rev. D | Phys. Rev. D 103, 095021 (2021) | 10.1103/PhysRevD.103.095021 | UT-STPD-21/02 | hep-ph hep-th | http://creativecommons.org/licenses/by/4.0/ | We use the $SU(5)$ model to show the presence in grand unified theories of an
electroweak monopole and a magnetic dumbbell ("meson") made up of a
monopole-antimonopole pair connected by a $Z$-magnetic flux tube. The monopole
is associated with the spontaneous breaking of the weak $SU(2)_L$ gauge
symmetry by the induced vacuum expectation value of a heavy scalar $SU(2)_L$
triplet with zero weak hypercharge contained in the adjoint Higgs 24-plet. This
monopole carries a Coulomb magnetic charge of $(3/4) (2\pi/e)$ as well as
$Z$-magnetic charge, where $2\pi/e$ denotes the unit Dirac magnetic charge. Its
total magnetic charge is $\sqrt{3/8}(4\pi/e)$, which is in agreement with the
Dirac quantization condition. The monopole weighs about 700 GeV, but because of
the attached $Z$-magnetic tube it exists, together with the antimonopole, in a
magnetic dumbbell configuration whose mass is expected to lie in the TeV range.
The presence of these topological structures in $SU(5)$ and $SO(10)$ and in
their supersymmetric extensions provides an exciting new avenue for testing
these theories in high-energy colliders.
| [
{
"created": "Sun, 14 Feb 2021 10:36:40 GMT",
"version": "v1"
},
{
"created": "Thu, 13 May 2021 06:43:26 GMT",
"version": "v2"
},
{
"created": "Fri, 21 May 2021 17:51:04 GMT",
"version": "v3"
}
] | 2021-05-26 | [
[
"Lazarides",
"George",
""
],
[
"Shafi",
"Qaisar",
""
]
] | We use the $SU(5)$ model to show the presence in grand unified theories of an electroweak monopole and a magnetic dumbbell ("meson") made up of a monopole-antimonopole pair connected by a $Z$-magnetic flux tube. The monopole is associated with the spontaneous breaking of the weak $SU(2)_L$ gauge symmetry by the induced vacuum expectation value of a heavy scalar $SU(2)_L$ triplet with zero weak hypercharge contained in the adjoint Higgs 24-plet. This monopole carries a Coulomb magnetic charge of $(3/4) (2\pi/e)$ as well as $Z$-magnetic charge, where $2\pi/e$ denotes the unit Dirac magnetic charge. Its total magnetic charge is $\sqrt{3/8}(4\pi/e)$, which is in agreement with the Dirac quantization condition. The monopole weighs about 700 GeV, but because of the attached $Z$-magnetic tube it exists, together with the antimonopole, in a magnetic dumbbell configuration whose mass is expected to lie in the TeV range. The presence of these topological structures in $SU(5)$ and $SO(10)$ and in their supersymmetric extensions provides an exciting new avenue for testing these theories in high-energy colliders. |
1612.00012 | James Alexander Osborne | Yang Bai, Sida Lu, and James Osborne | Beauty-full Tetraquarks | 5 pages, 3 figures. v2: References added | null | 10.1016/j.physletb.2019.134930 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this article we present a calculation of the $bb\bar{b}\bar{b}$ tetraquark
ground-state energy using a diffusion Monte Carlo method to solve the
non-relativistic many-body system. The static potential for the four quark
system is chosen to align with the flux-tube picture of QCD. Using this
approach, we find that the $0^{++}$ state has a mass of $18.69\pm
0.03~\mbox{GeV}$, which is around 100 MeV below twice the $\eta_b$ mass. This
bound state can behave as a four-lepton resonance via its decay to
$\Upsilon(1S) \Upsilon(1S)^* \rightarrow \ell^+ \ell^- \ell^+ \ell^-$.
| [
{
"created": "Wed, 30 Nov 2016 21:00:01 GMT",
"version": "v1"
},
{
"created": "Fri, 2 Dec 2016 20:29:08 GMT",
"version": "v2"
}
] | 2019-09-18 | [
[
"Bai",
"Yang",
""
],
[
"Lu",
"Sida",
""
],
[
"Osborne",
"James",
""
]
] | In this article we present a calculation of the $bb\bar{b}\bar{b}$ tetraquark ground-state energy using a diffusion Monte Carlo method to solve the non-relativistic many-body system. The static potential for the four quark system is chosen to align with the flux-tube picture of QCD. Using this approach, we find that the $0^{++}$ state has a mass of $18.69\pm 0.03~\mbox{GeV}$, which is around 100 MeV below twice the $\eta_b$ mass. This bound state can behave as a four-lepton resonance via its decay to $\Upsilon(1S) \Upsilon(1S)^* \rightarrow \ell^+ \ell^- \ell^+ \ell^-$. |
1711.01855 | Michal Krelina | Jan Cepila, Jesus Guillermo Contreras, Michal Krelina | Coherent and incoherent $\mathrm{J/}\psi$ photonuclear production in an
energy-dependent hot-spot model | null | Phys. Rev. C 97, 024901 (2018) | 10.1103/PhysRevC.97.024901 | null | hep-ph nucl-th | http://creativecommons.org/licenses/by/4.0/ | In a previous publication, we have presented a model for the photoproduction
of $\mathrm{J/}\psi$ vector mesons off protons, where the proton structure in
the impact-parameter plane is described by an energy-dependent hot-spot
profile. Here we extend this model to study the photonuclear production of
$\mathrm{J/}\psi$ vector mesons in coherent and incoherent interactions of
heavy nuclei. We study two methods to extend the model to the nuclear case:
using the standard Glauber-Gribov formalism and using geometric scaling to
obtain the nuclear saturation scale. We find that the incoherent cross section
changes sizably with the inclusion of subnucleonic hot spots, and that this
change is energy dependent. We propose to search for this behavior by measuring
the ratio of the incoherent to coherent cross section at different energies. We
compare the results of our model to results from RHIC and from the Run 1 at the
LHC finding a satisfactory agreement. We also present predictions for the LHC
at the new energies reached in Run 2. The predictions include $\mathrm{J/}\psi$
production in ultra-peripheral collisions, as well as the recently observed
photonuclear production in peripheral collisions.
| [
{
"created": "Mon, 6 Nov 2017 12:23:23 GMT",
"version": "v1"
},
{
"created": "Tue, 27 Feb 2018 12:14:06 GMT",
"version": "v2"
}
] | 2018-02-28 | [
[
"Cepila",
"Jan",
""
],
[
"Contreras",
"Jesus Guillermo",
""
],
[
"Krelina",
"Michal",
""
]
] | In a previous publication, we have presented a model for the photoproduction of $\mathrm{J/}\psi$ vector mesons off protons, where the proton structure in the impact-parameter plane is described by an energy-dependent hot-spot profile. Here we extend this model to study the photonuclear production of $\mathrm{J/}\psi$ vector mesons in coherent and incoherent interactions of heavy nuclei. We study two methods to extend the model to the nuclear case: using the standard Glauber-Gribov formalism and using geometric scaling to obtain the nuclear saturation scale. We find that the incoherent cross section changes sizably with the inclusion of subnucleonic hot spots, and that this change is energy dependent. We propose to search for this behavior by measuring the ratio of the incoherent to coherent cross section at different energies. We compare the results of our model to results from RHIC and from the Run 1 at the LHC finding a satisfactory agreement. We also present predictions for the LHC at the new energies reached in Run 2. The predictions include $\mathrm{J/}\psi$ production in ultra-peripheral collisions, as well as the recently observed photonuclear production in peripheral collisions. |
1712.03425 | M. Naeem Anwar | Muhammad Naeem Anwar, Yu Lu, Bing-Song Zou | Heavy Quark Spin Symmetry Violating Hadronic Transitions of Higher
Charmonia | Proceedings of the talk presented at "XVII International Conference
on Hadron Spectroscopy and Structure (Hadron2017)", 25-29 September 2017,
Salamanca, Spain | null | null | null | hep-ph hep-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In heavy quarkonia, hadronic transitions serve as an enlightened probe for
the structure and help to establish the understanding of light quark coupling
with a heavy degree of freedom. Moreover, in recent years, hadronic transitions
revealed remarkable discoveries to identify the new conventional heavy
quarkonia and extracting useful information about the so called "XYZ" exotic
states. In this contribution, we present our predictions for heavy quark spin
symmetry (HQSS) breaking hadronic transitions of higher $S$ and $D$ wave vector
charmonia based on our recently proposed model (inspired by Nambu-Jona-Lasinio
(NJL) model) to create light meson(s) in heavy quarkonium transitions. We also
suggest spectroscopic quantum numbers $(^{2S+1}L_J)$ for several observed
charmoniumlike states. Our analysis indicates that the $Y(4360)$ is most likely
to be a $3D$ dominant state.
| [
{
"created": "Sat, 9 Dec 2017 19:13:29 GMT",
"version": "v1"
}
] | 2017-12-12 | [
[
"Anwar",
"Muhammad Naeem",
""
],
[
"Lu",
"Yu",
""
],
[
"Zou",
"Bing-Song",
""
]
] | In heavy quarkonia, hadronic transitions serve as an enlightened probe for the structure and help to establish the understanding of light quark coupling with a heavy degree of freedom. Moreover, in recent years, hadronic transitions revealed remarkable discoveries to identify the new conventional heavy quarkonia and extracting useful information about the so called "XYZ" exotic states. In this contribution, we present our predictions for heavy quark spin symmetry (HQSS) breaking hadronic transitions of higher $S$ and $D$ wave vector charmonia based on our recently proposed model (inspired by Nambu-Jona-Lasinio (NJL) model) to create light meson(s) in heavy quarkonium transitions. We also suggest spectroscopic quantum numbers $(^{2S+1}L_J)$ for several observed charmoniumlike states. Our analysis indicates that the $Y(4360)$ is most likely to be a $3D$ dominant state. |
hep-ph/0202153 | Andrei Belitsky | A.V. Belitsky, T.D. Cohen | The large-N(c) nuclear potential puzzle | 17 pages, LaTeX, 5 figures | Phys.Rev. C65 (2002) 064008 | 10.1103/PhysRevC.65.064008 | null | hep-ph nucl-th | null | An analysis of the baryon-baryon potential from the point of view of
large-N(c) QCD is performed. A comparison is made between the N(c)-scaling
behavior directly obtained from an analysis at the quark-gluon level to the
N(c)-scaling of the potential for a generic hadronic field theory in which it
arises via meson exchanges and for which the parameters of the theory are given
by their canonical large-N(c) scaling behavior. The purpose of this comparison
is to use large-N(c) consistency to test the widespread view that the
interaction between nuclei arises from QCD through the exchange of mesons.
Although at the one- and two-meson exchange level the scaling rules for the
potential derived from the hadronic theory matches the quark-gluon level
prediction, at the three- and higher-meson exchange level a generic hadronic
theory yields a potential which scales with N(c) faster than that of the
quark-gluon theory.
| [
{
"created": "Fri, 15 Feb 2002 15:37:08 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Belitsky",
"A. V.",
""
],
[
"Cohen",
"T. D.",
""
]
] | An analysis of the baryon-baryon potential from the point of view of large-N(c) QCD is performed. A comparison is made between the N(c)-scaling behavior directly obtained from an analysis at the quark-gluon level to the N(c)-scaling of the potential for a generic hadronic field theory in which it arises via meson exchanges and for which the parameters of the theory are given by their canonical large-N(c) scaling behavior. The purpose of this comparison is to use large-N(c) consistency to test the widespread view that the interaction between nuclei arises from QCD through the exchange of mesons. Although at the one- and two-meson exchange level the scaling rules for the potential derived from the hadronic theory matches the quark-gluon level prediction, at the three- and higher-meson exchange level a generic hadronic theory yields a potential which scales with N(c) faster than that of the quark-gluon theory. |
2208.11399 | Matteo Maria Defranchis | Matteo M. Defranchis, Jan Kieseler, Katerina Lipka, Javier Mazzitelli | Running of the top quark mass at NNLO in QCD | null | null | null | MPP-2022-110 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The running of the top quark mass ($m_\mathrm{t}$) is probed at the
next-to-next-to-leading order (NNLO) in quantum chromodynamics (QCD) for the
first time. The result is obtained by comparing calculations in the modified
minimal subtraction ($\mathrm{\bar{MS}}$) renormalisation scheme to a
differential measurement of the top quark-antiquark ($\mathrm{t\bar{t}}$)
production cross section at $\sqrt{s} = 13~\mathrm{TeV}$. The scale dependence
of $m_\mathrm{t}$ is extracted as a function of the invariant mass of the
$\mathrm{t\bar{t}}$ system, up to an energy scale of about $0.5~\mathrm{TeV}$.
The observed running is found to be in good agreement with the three-loop
solution of the QCD renormalisation group equations.
| [
{
"created": "Wed, 24 Aug 2022 09:40:38 GMT",
"version": "v1"
}
] | 2022-08-25 | [
[
"Defranchis",
"Matteo M.",
""
],
[
"Kieseler",
"Jan",
""
],
[
"Lipka",
"Katerina",
""
],
[
"Mazzitelli",
"Javier",
""
]
] | The running of the top quark mass ($m_\mathrm{t}$) is probed at the next-to-next-to-leading order (NNLO) in quantum chromodynamics (QCD) for the first time. The result is obtained by comparing calculations in the modified minimal subtraction ($\mathrm{\bar{MS}}$) renormalisation scheme to a differential measurement of the top quark-antiquark ($\mathrm{t\bar{t}}$) production cross section at $\sqrt{s} = 13~\mathrm{TeV}$. The scale dependence of $m_\mathrm{t}$ is extracted as a function of the invariant mass of the $\mathrm{t\bar{t}}$ system, up to an energy scale of about $0.5~\mathrm{TeV}$. The observed running is found to be in good agreement with the three-loop solution of the QCD renormalisation group equations. |
1705.03696 | Kin-ya Oda | Ryusuke Jinno, Kunio Kaneta, and Kin-ya Oda | Hillclimbing Higgs inflation | 5 pages, 3 figures, 1 table (v1); published version, references and
footnotes added (v2) | Phys. Rev. D 97, 023523 (2018) | 10.1103/PhysRevD.97.023523 | CTPU-17-18, OU-HET/935 | hep-ph astro-ph.CO gr-qc hep-th | http://creativecommons.org/licenses/by/4.0/ | We propose a realization of cosmic inflation with the Higgs field when the
Higgs potential has degenerate vacua by employing the recently proposed idea of
hillclimbing inflation. The resultant inflationary predictions exhibit a
sizable deviation from those of the ordinary Higgs inflation.
| [
{
"created": "Wed, 10 May 2017 10:51:50 GMT",
"version": "v1"
},
{
"created": "Thu, 5 Jul 2018 04:20:39 GMT",
"version": "v2"
}
] | 2018-07-06 | [
[
"Jinno",
"Ryusuke",
""
],
[
"Kaneta",
"Kunio",
""
],
[
"Oda",
"Kin-ya",
""
]
] | We propose a realization of cosmic inflation with the Higgs field when the Higgs potential has degenerate vacua by employing the recently proposed idea of hillclimbing inflation. The resultant inflationary predictions exhibit a sizable deviation from those of the ordinary Higgs inflation. |
1111.5475 | Michael Buballa | J. Wambach, K. Heckmann and M. Buballa | Transport Properties of Strong-Interaction Matter | 8 pages, 4 figures, presented at the HIC for FAIR Workshop and XXVIII
Max Born Symposium "Three days on Quarkyonic Island", Wroclaw, May 19-21,
2011; v2: conversion to Pa in fig. 2 corrected | null | 10.1063/1.3700682 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The properties of strong-interaction matter are probed in ultra-relativistic
heavy-ion collisions. In the context of measurements of the elliptic flow at
RHIC and the LHC the shear viscosity is of particular interest. In this
presentation we discuss recent results for eta/s in hadronic matter at
vanishing baryo-chemical potential within kinetic theory. Using the
Nambu-Jona-Lasinio model, special attention is paid to effects arising from the
restoration of spontaneously broken chiral symmetry with increasing
temperature.
| [
{
"created": "Wed, 23 Nov 2011 12:36:24 GMT",
"version": "v1"
},
{
"created": "Tue, 13 Mar 2012 12:41:19 GMT",
"version": "v2"
}
] | 2015-06-03 | [
[
"Wambach",
"J.",
""
],
[
"Heckmann",
"K.",
""
],
[
"Buballa",
"M.",
""
]
] | The properties of strong-interaction matter are probed in ultra-relativistic heavy-ion collisions. In the context of measurements of the elliptic flow at RHIC and the LHC the shear viscosity is of particular interest. In this presentation we discuss recent results for eta/s in hadronic matter at vanishing baryo-chemical potential within kinetic theory. Using the Nambu-Jona-Lasinio model, special attention is paid to effects arising from the restoration of spontaneously broken chiral symmetry with increasing temperature. |
1512.05100 | Stanley J. Brodsky | Stanley J. Brodsky | Novel Perspectives from Light-Front QCD, Superconformal Algebra, and
Light-Front Holography | To appear in the Proceedings of the 18th Bled workshop "What Comes
Beyond the Standard Models", Bled, Slovenia, July 11-19, 2015. arXiv admin
note: substantial text overlap with arXiv:1511.04142 | null | null | SLAC-PUB-16432 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Light-Front Quantization -- Dirac's "Front Form" -- provides a physical,
frame-independent formalism for hadron dynamics and structure. Observables such
as structure functions, transverse momentum distributions, and distribution
amplitudes are defined from the hadronic LFWFs. One obtains new insights into
the hadronic mass scale, the hadronic spectrum, and the functional form of the
QCD running coupling in the nonperturbative domain using light-front
holography. In addition, superconformal algebra leads to remarkable
supersymmetric relations between mesons and baryons. I also discuss evidence
that the antishadowing of nuclear structure functions is non-universal, i.e.,
flavor dependent, and why shadowing and antishadowing phenomena may be
incompatible with the momentum and other sum rules for the nuclear parton
distribution functions.
| [
{
"created": "Wed, 16 Dec 2015 09:34:16 GMT",
"version": "v1"
},
{
"created": "Fri, 18 Dec 2015 22:42:38 GMT",
"version": "v2"
}
] | 2015-12-22 | [
[
"Brodsky",
"Stanley J.",
""
]
] | Light-Front Quantization -- Dirac's "Front Form" -- provides a physical, frame-independent formalism for hadron dynamics and structure. Observables such as structure functions, transverse momentum distributions, and distribution amplitudes are defined from the hadronic LFWFs. One obtains new insights into the hadronic mass scale, the hadronic spectrum, and the functional form of the QCD running coupling in the nonperturbative domain using light-front holography. In addition, superconformal algebra leads to remarkable supersymmetric relations between mesons and baryons. I also discuss evidence that the antishadowing of nuclear structure functions is non-universal, i.e., flavor dependent, and why shadowing and antishadowing phenomena may be incompatible with the momentum and other sum rules for the nuclear parton distribution functions. |
1612.07958 | S. Ganesh | S. Ganesh, Captain R. Singh and M. Mishra | $\psi(2S)$ enhancement in p-Pb collision as an indication of QGP
formation at the LHC | 17 pages, 11 figures. Accepted for publication in Journal of Physics
G | J. Phys. G: Nucl. Part. Phys. 45, 035003 (2018) | 10.1088/1361-6471/aaa46a | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Proton-nucleus collisions serve as an important baseline for the
understanding and interpretation of the nucleus-nucleus collisions. These
collisions have been employed to characterize the cold nuclear matter effects
at SPS and RHIC energies for the past several years, as it was thought that
Quark-Gluon Plasma (QGP) is not formed in such collisions. However, at the
Large Hadron Collider (LHC), there seems a possibility that QGP is formed
during proton-lead (p$-$Pb) collisions. In this work, we have derived an
expression for gluon induced excitation of $J/\psi$ to $\psi(2S)$, using
pNRQCD, and show that the relative enhancement of $\psi(2S)$ vis a vis
$J/\psi$, especially at high $p_T$, gives further indication that the QGP is
indeed formed in p$-$Pb collisions at the most central collisions at LHC
energy. $J/\psi$ and $\psi(2S)$ suppression effects seen at ALICE are also
qualitatively explained.
| [
{
"created": "Fri, 23 Dec 2016 13:03:09 GMT",
"version": "v1"
},
{
"created": "Wed, 3 Jan 2018 03:57:34 GMT",
"version": "v2"
}
] | 2018-02-06 | [
[
"Ganesh",
"S.",
""
],
[
"Singh",
"Captain R.",
""
],
[
"Mishra",
"M.",
""
]
] | Proton-nucleus collisions serve as an important baseline for the understanding and interpretation of the nucleus-nucleus collisions. These collisions have been employed to characterize the cold nuclear matter effects at SPS and RHIC energies for the past several years, as it was thought that Quark-Gluon Plasma (QGP) is not formed in such collisions. However, at the Large Hadron Collider (LHC), there seems a possibility that QGP is formed during proton-lead (p$-$Pb) collisions. In this work, we have derived an expression for gluon induced excitation of $J/\psi$ to $\psi(2S)$, using pNRQCD, and show that the relative enhancement of $\psi(2S)$ vis a vis $J/\psi$, especially at high $p_T$, gives further indication that the QGP is indeed formed in p$-$Pb collisions at the most central collisions at LHC energy. $J/\psi$ and $\psi(2S)$ suppression effects seen at ALICE are also qualitatively explained. |
2107.11613 | Muhammad Waqas | M. Waqas, G.X Peng, Z. Wazir, Hailing Lao | Analysis of kinetic freeze out temperature and transverse flow velocity
in nucleus-nucleus and proton-proton collisions at same center of mass energy | null | Int. j. of mod phys. Vol. 30, 2150061, 2021 | 10.1142/S0218301321500610 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Transverse momentum spectra of different types of identified charged
particles in central Gold-Gold (Au-Au) collisions, and inelastic (INEL) or
non-single-diffrative (NSD) proton-proton (pp) collisions at the Relativistic
Heavy Ion Collider (RHIC), as well as in central and peripheral Lead-Lead
(Pb-Pb) collisions, and INEL or NSD pp collisions at the Large Hadron Collider
(LHC) are analyzed by the blast wave model with Tsallis statistics. The model
results are approximately in agreement with the experimental data measured by
STAR, PHENIX and ALICE Collaborations in special transverse momentum ranges.
Kinetic freeze out temperature and transverse flow velocity are extracted from
the transverse momentum spectra of the particles. It is shown that kinetic
freeze out temperature of the emission source depends on mass of the particles,
which reveals the mass differential kinetic freeze out scenario in collisions
at RHIC and LHC. Furthermore, the kinetic freeze out temperature and transverse
flow velocity in central nucleus-nucleus (AA) collisions are larger than in
peripheral collisions, and both of them are slightly larger in peripheral
nucleus-nucleus collisions or almost equivalent to that in pp proton-proton
collisions at the same center of mass energy which shows their similar
thermodynamic nature.
| [
{
"created": "Sat, 24 Jul 2021 14:03:50 GMT",
"version": "v1"
}
] | 2021-10-04 | [
[
"Waqas",
"M.",
""
],
[
"Peng",
"G. X",
""
],
[
"Wazir",
"Z.",
""
],
[
"Lao",
"Hailing",
""
]
] | Transverse momentum spectra of different types of identified charged particles in central Gold-Gold (Au-Au) collisions, and inelastic (INEL) or non-single-diffrative (NSD) proton-proton (pp) collisions at the Relativistic Heavy Ion Collider (RHIC), as well as in central and peripheral Lead-Lead (Pb-Pb) collisions, and INEL or NSD pp collisions at the Large Hadron Collider (LHC) are analyzed by the blast wave model with Tsallis statistics. The model results are approximately in agreement with the experimental data measured by STAR, PHENIX and ALICE Collaborations in special transverse momentum ranges. Kinetic freeze out temperature and transverse flow velocity are extracted from the transverse momentum spectra of the particles. It is shown that kinetic freeze out temperature of the emission source depends on mass of the particles, which reveals the mass differential kinetic freeze out scenario in collisions at RHIC and LHC. Furthermore, the kinetic freeze out temperature and transverse flow velocity in central nucleus-nucleus (AA) collisions are larger than in peripheral collisions, and both of them are slightly larger in peripheral nucleus-nucleus collisions or almost equivalent to that in pp proton-proton collisions at the same center of mass energy which shows their similar thermodynamic nature. |
1210.7975 | Rafael Cerezo | Rafael Cerezo, Jo\~ao G. Rosa | Warm Inflection | 12 pages, 5 figures. References added. Published version JHEP | JHEP01(2013)024 | 10.1007/JHEP01(2013)024 | null | hep-ph astro-ph.CO | http://creativecommons.org/licenses/by/3.0/ | While ubiquitous in supersymmetric and string theory models, inflationary
scenarios near an inflection point in the scalar potential generically require
a severe fine-tuning of a priori unrelated supersymmetry breaking effects. We
show that this can be significantly alleviated by the inclusion of dissipative
effects that damp the inflaton's motion and produce a nearly-thermal radiation
bath. We focus on the case where the slow-rolling inflaton directly excites
heavy virtual modes that then decay into light degrees of freedom, although our
main qualitative results should apply in other regimes. Furthermore, our
analysis shows that the minimum amount of dissipation required to keep the
temperature of the radiation bath above the Hubble rate during inflation is
largely independent of the degree of flatness of the potential, although it
depends on the field value at the inflection point. We then discuss the
relevance of this result to warm inflation model building.
| [
{
"created": "Tue, 30 Oct 2012 12:11:30 GMT",
"version": "v1"
},
{
"created": "Mon, 14 Jan 2013 11:42:39 GMT",
"version": "v2"
}
] | 2013-01-15 | [
[
"Cerezo",
"Rafael",
""
],
[
"Rosa",
"João G.",
""
]
] | While ubiquitous in supersymmetric and string theory models, inflationary scenarios near an inflection point in the scalar potential generically require a severe fine-tuning of a priori unrelated supersymmetry breaking effects. We show that this can be significantly alleviated by the inclusion of dissipative effects that damp the inflaton's motion and produce a nearly-thermal radiation bath. We focus on the case where the slow-rolling inflaton directly excites heavy virtual modes that then decay into light degrees of freedom, although our main qualitative results should apply in other regimes. Furthermore, our analysis shows that the minimum amount of dissipation required to keep the temperature of the radiation bath above the Hubble rate during inflation is largely independent of the degree of flatness of the potential, although it depends on the field value at the inflection point. We then discuss the relevance of this result to warm inflation model building. |
1006.2245 | Debasish Borah | Debasish Borah, Sudhanwa Patra and Utpal Sarkar | TeV scale Left Right Symmetry with spontaneous D-parity breaking | 26 pages, 3 figures, Journal Version | Phys.Rev.D83:035007,2011 | 10.1103/PhysRevD.83.035007 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The different scenarios of spontaneous breaking of D-parity have been studied
in both non-supersymmetric and supersymmetric version of the left-right
symmetric models(LRSM). We explore the possibility of a TeV scale $SU(2)_R$
breaking scale $M_R$ and hence TeV scale right handed neutrinos from both
minimization of the scalar potential as well as the coupling constant
unification point of view. We show that although minimization of the scalar
potential allows the possibility of a TeV scale $M_R$ and tiny neutrino masses
in LRSM with spontaneous D-parity breaking, the gauge coupling unification at a
high scale $\sim 10^{16}$ GeV does not favour a TeV scale symmetry breaking
except in the supersymmetric left-right (SUSYLR) model with Higgs doublet and
bidoublet. The phenomenology of neutrino mass is also discussed.
| [
{
"created": "Fri, 11 Jun 2010 09:58:02 GMT",
"version": "v1"
},
{
"created": "Thu, 17 Feb 2011 07:49:16 GMT",
"version": "v2"
}
] | 2011-02-22 | [
[
"Borah",
"Debasish",
""
],
[
"Patra",
"Sudhanwa",
""
],
[
"Sarkar",
"Utpal",
""
]
] | The different scenarios of spontaneous breaking of D-parity have been studied in both non-supersymmetric and supersymmetric version of the left-right symmetric models(LRSM). We explore the possibility of a TeV scale $SU(2)_R$ breaking scale $M_R$ and hence TeV scale right handed neutrinos from both minimization of the scalar potential as well as the coupling constant unification point of view. We show that although minimization of the scalar potential allows the possibility of a TeV scale $M_R$ and tiny neutrino masses in LRSM with spontaneous D-parity breaking, the gauge coupling unification at a high scale $\sim 10^{16}$ GeV does not favour a TeV scale symmetry breaking except in the supersymmetric left-right (SUSYLR) model with Higgs doublet and bidoublet. The phenomenology of neutrino mass is also discussed. |
1409.4915 | Robert Foot | Robert Foot, Archil Kobakhidze and Alexander Spencer-Smith | Criticality in the scale invariant standard model (squared) | About 7 pages | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider first the standard model Lagrangian with $\mu_h^2$ Higgs
potential term set to zero. We point out that this clasically scale invariant
theory potentially exhibits radiative electroweak/scale symmetry breaking with
very high vacuum expectation value (VEV) for the Higgs field, $< \phi > \approx
10^{17-18}$ GeV. Furthermore, if such a vacuum were realized then cancellation
of vacuum energy automatically implies that this nontrivial vacuum is
degenerate with the trivial unbroken vacuum. Such a theory would therefore be
critical with the Higgs self-coupling and its beta function nearly vanishing at
the symmetry breaking minimum, $\lambda (\mu=< \phi >)\approx \beta_{\lambda}
(\mu=< \phi >)\approx 0$. A phenomenologically viable model that predicts this
criticality property arises if we consider two copies of the standard model
Lagrangian, with exact $Z_2$ symmetry swapping each ordinary particle with a
partner. The spontaneously broken vacuum can then arise where one sector gains
the high scale VEV, while the other gains the electroweak scale VEV. The low
scale VEV is perturbed away from zero due to a Higgs portal coupling, or via
the usual small Higgs mass terms $\mu_h^2$, which softly break the scale
invariance. In either case, the cancellation of vacuum energy requires $M_t =
(171.53 \pm 0.42)$ GeV, which is close to its measured value of $(173.34 \pm
0.76)$ GeV.
| [
{
"created": "Wed, 17 Sep 2014 09:30:29 GMT",
"version": "v1"
}
] | 2014-09-18 | [
[
"Foot",
"Robert",
""
],
[
"Kobakhidze",
"Archil",
""
],
[
"Spencer-Smith",
"Alexander",
""
]
] | We consider first the standard model Lagrangian with $\mu_h^2$ Higgs potential term set to zero. We point out that this clasically scale invariant theory potentially exhibits radiative electroweak/scale symmetry breaking with very high vacuum expectation value (VEV) for the Higgs field, $< \phi > \approx 10^{17-18}$ GeV. Furthermore, if such a vacuum were realized then cancellation of vacuum energy automatically implies that this nontrivial vacuum is degenerate with the trivial unbroken vacuum. Such a theory would therefore be critical with the Higgs self-coupling and its beta function nearly vanishing at the symmetry breaking minimum, $\lambda (\mu=< \phi >)\approx \beta_{\lambda} (\mu=< \phi >)\approx 0$. A phenomenologically viable model that predicts this criticality property arises if we consider two copies of the standard model Lagrangian, with exact $Z_2$ symmetry swapping each ordinary particle with a partner. The spontaneously broken vacuum can then arise where one sector gains the high scale VEV, while the other gains the electroweak scale VEV. The low scale VEV is perturbed away from zero due to a Higgs portal coupling, or via the usual small Higgs mass terms $\mu_h^2$, which softly break the scale invariance. In either case, the cancellation of vacuum energy requires $M_t = (171.53 \pm 0.42)$ GeV, which is close to its measured value of $(173.34 \pm 0.76)$ GeV. |
hep-ph/0111127 | Stanley J. Brodsky | S. J. Brodsky | Perspectives and Challenges for QCD Phenomenology | Invited talk presented at the APS / DPF / DPB Summer Study On The
Future Of Particle Physics (Snowmass 2001), 30 Jun - 21 Jul 2001, Snowmass,
Colorado, and the 6th LNF Spring School 'Bruno Touschek' In Nuclear,
Subnuclear And Astroparticle Physics, 28 May - 2 Jun 2001, Frascati, Italy | eConf C010630:E211,2001 | null | SLAC-PUB-9022 | hep-ph | null | A fundamental understanding of quantum chromodynamics, particularly at the
amplitude level, is essential for progress in high energy physics. For example,
the measurement and interpretation of the basic parameters of the electroweak
theory and CP violation depends on an understanding of the dynamics and phase
structure of exclusive B-meson decay amplitudes. In this review, I discuss a
number of ways in which the required hadron wavefunctions can be measured (such
as two-photon reactions and diffractive dissociation) or calculated from first
principles. An important tool for describing relativistic composite systems in
quantum field theory is the light-front Fock expansion, which encodes the
properties of a hadrons in terms of a set of frame-independent n-particle
wavefunctions. Evolution in light-cone time allows the construction of an
"event amplitude generator" in which only non-ghost physical degrees of freedom
and integration over physical phase appear. The diffractive dissociation of a
hadron at high energies, by either Coulomb or Pomeron exchange, has a natural
description in QCD as the materialization of the projectile's light-cone
wavefunctions; in particular, the diffractive dissociation of a meson, baryon,
or photon into high transverse momentum jets measures the shape and other
features of the projectile's distribution amplitude. I also review recent work
which shows that the structure functions measured in deep inelastic lepton
scattering are affected by final-state rescattering, thus modifying their
connection with the light-cone probability distributions. In particular, the
shadowing of nuclear structure functions is due to destructive interference
effects from leading-twist diffraction of the virtual photon, physics not
included in the nuclear light-cone wavefunctions.
| [
{
"created": "Sat, 10 Nov 2001 23:43:00 GMT",
"version": "v1"
}
] | 2009-09-11 | [
[
"Brodsky",
"S. J.",
""
]
] | A fundamental understanding of quantum chromodynamics, particularly at the amplitude level, is essential for progress in high energy physics. For example, the measurement and interpretation of the basic parameters of the electroweak theory and CP violation depends on an understanding of the dynamics and phase structure of exclusive B-meson decay amplitudes. In this review, I discuss a number of ways in which the required hadron wavefunctions can be measured (such as two-photon reactions and diffractive dissociation) or calculated from first principles. An important tool for describing relativistic composite systems in quantum field theory is the light-front Fock expansion, which encodes the properties of a hadrons in terms of a set of frame-independent n-particle wavefunctions. Evolution in light-cone time allows the construction of an "event amplitude generator" in which only non-ghost physical degrees of freedom and integration over physical phase appear. The diffractive dissociation of a hadron at high energies, by either Coulomb or Pomeron exchange, has a natural description in QCD as the materialization of the projectile's light-cone wavefunctions; in particular, the diffractive dissociation of a meson, baryon, or photon into high transverse momentum jets measures the shape and other features of the projectile's distribution amplitude. I also review recent work which shows that the structure functions measured in deep inelastic lepton scattering are affected by final-state rescattering, thus modifying their connection with the light-cone probability distributions. In particular, the shadowing of nuclear structure functions is due to destructive interference effects from leading-twist diffraction of the virtual photon, physics not included in the nuclear light-cone wavefunctions. |
hep-ph/0504264 | Jacob Linder | J. Linder | Neutrino matter potentials induced by Earth | 8 pages, 0 figures. Pedagogical derivation for students | null | null | null | hep-ph | null | An instructive method of deriving the matter potentials felt by neutrinos
propagating through matter on Earth is presented. This paper thoroughly guides
the reader through the calculations involving the effective weak Hamiltonian
for lepton and quark scattering. The matter potentials are well-known results
since the late 70's, but a detailed and pedagogical calculation of these
quantities is hard to find. We derive potentials due to charged and neutral
current scattering on electrons, neutrons and protons. Intended readership is
for undergraduates/graduates in the fields of relativistic quantum mechanics
and quantum field theory. In addition to the derivation of the potentials for
neutrinos, we explicitely study the origin of the reversed sign for potentials
in the case of antineutrino-scattering.
| [
{
"created": "Wed, 27 Apr 2005 20:53:48 GMT",
"version": "v1"
},
{
"created": "Tue, 3 May 2005 15:05:01 GMT",
"version": "v2"
},
{
"created": "Sun, 12 Jun 2005 19:52:01 GMT",
"version": "v3"
},
{
"created": "Sun, 15 Jan 2006 21:04:00 GMT",
"version": "v4"
}
] | 2007-05-23 | [
[
"Linder",
"J.",
""
]
] | An instructive method of deriving the matter potentials felt by neutrinos propagating through matter on Earth is presented. This paper thoroughly guides the reader through the calculations involving the effective weak Hamiltonian for lepton and quark scattering. The matter potentials are well-known results since the late 70's, but a detailed and pedagogical calculation of these quantities is hard to find. We derive potentials due to charged and neutral current scattering on electrons, neutrons and protons. Intended readership is for undergraduates/graduates in the fields of relativistic quantum mechanics and quantum field theory. In addition to the derivation of the potentials for neutrinos, we explicitely study the origin of the reversed sign for potentials in the case of antineutrino-scattering. |
1106.6177 | Boglione Mariaelena | M. Boglione, S. Melis, A. Prokudin | Partonic Transverse Motion in Unpolarized Semi-Inclusive Deep Inelastic
Scattering Processes | 19 pages, 15 figures | Phys.Rev.D84:034033,2011 | 10.1103/PhysRevD.84.034033 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We analyse the role of partonic transverse motion in unpolarized
Semi-Inclusive Deep Inelastic Scattering (SIDIS) processes. Imposing
appropriate kinematical conditions, we find some constraints which fix an upper
limit to the range of allowed k_perp values. We show that, applying these
additional requirements on the partonic kinematics, we obtain different results
with respect to the usual phenomenological approach based on the Gaussian
smearing with analytical integration over an unlimited range of k_perp values.
These variations are particularly interesting for some observables, like the <
cos phi_h > azimuthal modulation of the unpolarized SIDIS cross section or the
average transverse momentum of the final, detected hadron.
| [
{
"created": "Thu, 30 Jun 2011 10:28:27 GMT",
"version": "v1"
}
] | 2011-09-14 | [
[
"Boglione",
"M.",
""
],
[
"Melis",
"S.",
""
],
[
"Prokudin",
"A.",
""
]
] | We analyse the role of partonic transverse motion in unpolarized Semi-Inclusive Deep Inelastic Scattering (SIDIS) processes. Imposing appropriate kinematical conditions, we find some constraints which fix an upper limit to the range of allowed k_perp values. We show that, applying these additional requirements on the partonic kinematics, we obtain different results with respect to the usual phenomenological approach based on the Gaussian smearing with analytical integration over an unlimited range of k_perp values. These variations are particularly interesting for some observables, like the < cos phi_h > azimuthal modulation of the unpolarized SIDIS cross section or the average transverse momentum of the final, detected hadron. |
hep-ph/0002213 | Sven Heinemeyer | S. Heinemeyer, W. Hollik, G. Weiglein | FeynHiggsFast: a program for a fast calculation of masses and mixing
angles in the Higgs Sector of the MSSM | 10 pages, 6 figures. Extended version of the contribution to the
Report of the HIGGS working group for the Workshop ``Physics at TeV
Colliders'' Les Houches, France, June 1999 | null | null | CERN-TH/2000-55, DESY 00-020, KA-TP-3-2000 | hep-ph | null | FeynHiggsFast is a Fortran code for the calculation of the masses and the
mixing angle of the neutral CP-even Higgs bosons in the MSSM up to two-loop
order. It is based on a compact analytical approximation formula of the
complete diagrammatic one-loop and the dominant two-loop contributions. At the
one-loop level a leading logarithmic result is used, taking into account all
sectors of the MSSM. At the two-loop level at O(alpha alpha_s) the leading
logarithmic and non-logarithmic contributions are taken into account. The
approximation formula is valid for arbitrary choices of the parameters in the
Higgs sector of the model. Comparing its quality to the full diagrammatic
result, we find agreement better than 2 GeV for most parts of the MSSM
parameter space.
| [
{
"created": "Sat, 19 Feb 2000 14:19:39 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Heinemeyer",
"S.",
""
],
[
"Hollik",
"W.",
""
],
[
"Weiglein",
"G.",
""
]
] | FeynHiggsFast is a Fortran code for the calculation of the masses and the mixing angle of the neutral CP-even Higgs bosons in the MSSM up to two-loop order. It is based on a compact analytical approximation formula of the complete diagrammatic one-loop and the dominant two-loop contributions. At the one-loop level a leading logarithmic result is used, taking into account all sectors of the MSSM. At the two-loop level at O(alpha alpha_s) the leading logarithmic and non-logarithmic contributions are taken into account. The approximation formula is valid for arbitrary choices of the parameters in the Higgs sector of the model. Comparing its quality to the full diagrammatic result, we find agreement better than 2 GeV for most parts of the MSSM parameter space. |
2009.00356 | Arjun Berera | Arjun Berera | Quantum coherence to interstellar distances | In Press Physical Review D 2020 | null | null | null | hep-ph astro-ph.GA quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Quantum coherence could be sustained up to interstellar distances. It is
shown that the photon mean free path in certain regions of the electromagnetic
spectrum, such as within the radio or x-ray ranges, could allow sustaining of
the quantum state of a photon up to galactic distances. Therefore processes
involving quantum entanglement, such as quantum teleportation, could be
realized over very long distances in the Milky Way or other galaxies. This is
of fundamental interest and offers a new direction in the role of quantum
mechanics. Some limited applications of this observation are discussed.
| [
{
"created": "Tue, 1 Sep 2020 11:23:54 GMT",
"version": "v1"
}
] | 2020-09-04 | [
[
"Berera",
"Arjun",
""
]
] | Quantum coherence could be sustained up to interstellar distances. It is shown that the photon mean free path in certain regions of the electromagnetic spectrum, such as within the radio or x-ray ranges, could allow sustaining of the quantum state of a photon up to galactic distances. Therefore processes involving quantum entanglement, such as quantum teleportation, could be realized over very long distances in the Milky Way or other galaxies. This is of fundamental interest and offers a new direction in the role of quantum mechanics. Some limited applications of this observation are discussed. |
hep-ph/9911384 | Jose Kenichi Mizukoshi | J. K. Mizukoshi | The Paradox of Charmonium Production | 14 pages, 6 figures, RevTeX, Minor Changes, One Ref. Added | null | null | null | hep-ph | null | The CDF preliminary analysis on polarized charmonium production at moderate
transverse momentum, $p_T \sim 4 - 20$ GeV, severely challenges the color octet
model (COM), which predicts quarkonium to be transversely polarized with
increasing $p_T$. Based on this data, we analyze the compatibility of the
Tevatron and the photoproduction at HERA in the context of the COM. Due to the
uncertainty on the extraction of non-relativistic QCD (NRQCD) matrix elements
and a lack of complete next-to-leading order calculations, one cannot
completely rule out the COM. Nonetheless, both collider experiments seem to
push the input matrix elements to opposite directions, and the puzzle of
quarkonium polarization remains unsolved.
| [
{
"created": "Tue, 16 Nov 1999 22:10:51 GMT",
"version": "v1"
},
{
"created": "Wed, 24 Nov 1999 17:22:05 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Mizukoshi",
"J. K.",
""
]
] | The CDF preliminary analysis on polarized charmonium production at moderate transverse momentum, $p_T \sim 4 - 20$ GeV, severely challenges the color octet model (COM), which predicts quarkonium to be transversely polarized with increasing $p_T$. Based on this data, we analyze the compatibility of the Tevatron and the photoproduction at HERA in the context of the COM. Due to the uncertainty on the extraction of non-relativistic QCD (NRQCD) matrix elements and a lack of complete next-to-leading order calculations, one cannot completely rule out the COM. Nonetheless, both collider experiments seem to push the input matrix elements to opposite directions, and the puzzle of quarkonium polarization remains unsolved. |
2108.11493 | Craig Roberts | Zhu-Fang Cui, Fei Gao, Daniele Binosi, Lei Chang, Craig D. Roberts and
Sebastian M. Schmidt | Valence quark ratio in the proton | 6 pages, 3 figures | Chin. Phys. Lett. Express 39 (04) (2022) 041401/1-5 | 10.1088/0256-307X/39/4/041401 | NJU-INP 049/21 | hep-ph hep-ex hep-lat nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Beginning with precise data on the ratio of structure functions in deep
inelastic scattering (DIS) from $^3$He and $^3$H, collected on the domain $0.19
\leq x_B \leq 0.83$, where $x_B$ is the Bjorken scaling variable, we employ a
robust method for extrapolating such data to arrive at a model-independent
result for the $x_B=1$ value of the ratio of neutron and proton structure
functions. Combining this with information obtained in analyses of DIS from
nuclei, corrected for target-structure dependence, we arrive at a prediction
for the proton's valence-quark ratio: $\left. d_v/u_v \right|_{x_B\to 1} =
0.230 (57)$. Requiring consistency with this result presents a challenge to
many descriptions of proton structure.
| [
{
"created": "Wed, 25 Aug 2021 22:09:33 GMT",
"version": "v1"
},
{
"created": "Thu, 26 May 2022 03:39:59 GMT",
"version": "v2"
}
] | 2022-05-27 | [
[
"Cui",
"Zhu-Fang",
""
],
[
"Gao",
"Fei",
""
],
[
"Binosi",
"Daniele",
""
],
[
"Chang",
"Lei",
""
],
[
"Roberts",
"Craig D.",
""
],
[
"Schmidt",
"Sebastian M.",
""
]
] | Beginning with precise data on the ratio of structure functions in deep inelastic scattering (DIS) from $^3$He and $^3$H, collected on the domain $0.19 \leq x_B \leq 0.83$, where $x_B$ is the Bjorken scaling variable, we employ a robust method for extrapolating such data to arrive at a model-independent result for the $x_B=1$ value of the ratio of neutron and proton structure functions. Combining this with information obtained in analyses of DIS from nuclei, corrected for target-structure dependence, we arrive at a prediction for the proton's valence-quark ratio: $\left. d_v/u_v \right|_{x_B\to 1} = 0.230 (57)$. Requiring consistency with this result presents a challenge to many descriptions of proton structure. |
0710.0978 | Leonid Glozman | L. Ya. Glozman | QCD symmetries in excited hadrons | 10 pp, Invited talk at MENU 2007, September 10 - 14, 2007, Juelich,
Germany | ECONFC070910:140,2007 | null | null | hep-ph hep-ex hep-lat hep-th nucl-th | null | Recent developments for chiral and $U(1)_A$ restorations in excited hadrons
are reviewed. We emphasize predictions of the chiral symmetry restoration
scenario for axial charges and couplings to Goldstone bosons. Using very
general chiral symmetry arguments it is shown that strict chiral restoration in
a given excited nucleon forbids its decay into the $N \pi$ channel. We confront
this prediction with the $N^*N\pi$ coupling constants extracted from the decay
widths and observe a 100 % correlation of these data with the spectroscopic
parity doublet patterns. These results suggest that the lowest approximate
chiral parity doublet is the $N(1440) - N(1535)$ pair. In the meson sector we
discuss predictions of the chiral symmetry restoration for still missing states
and a signature of the higher symmetry observed in new $\bar p p$ data. We
conclude with the exactly solvable chirally symmetric and confining model that
can be considered as a generalization of the 1+1 dimensional 't Hooft model to
4 dimensions. Complete spectra of $\bar q q$ mesons demonstrate a fast chiral
restoration with increasing $J$ and a slow one with increasing $n$.
| [
{
"created": "Thu, 4 Oct 2007 10:55:59 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Glozman",
"L. Ya.",
""
]
] | Recent developments for chiral and $U(1)_A$ restorations in excited hadrons are reviewed. We emphasize predictions of the chiral symmetry restoration scenario for axial charges and couplings to Goldstone bosons. Using very general chiral symmetry arguments it is shown that strict chiral restoration in a given excited nucleon forbids its decay into the $N \pi$ channel. We confront this prediction with the $N^*N\pi$ coupling constants extracted from the decay widths and observe a 100 % correlation of these data with the spectroscopic parity doublet patterns. These results suggest that the lowest approximate chiral parity doublet is the $N(1440) - N(1535)$ pair. In the meson sector we discuss predictions of the chiral symmetry restoration for still missing states and a signature of the higher symmetry observed in new $\bar p p$ data. We conclude with the exactly solvable chirally symmetric and confining model that can be considered as a generalization of the 1+1 dimensional 't Hooft model to 4 dimensions. Complete spectra of $\bar q q$ mesons demonstrate a fast chiral restoration with increasing $J$ and a slow one with increasing $n$. |
2107.11405 | Daneng Yang | Haipeng An, Zhen Hu, Zhen Liu, Daneng Yang | Exploring Uncharted Soft Displaced Vertices in Open Data | 18 pages, 12 figures | null | null | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | A cluster of soft displaced tracks corresponds to the dark matter
co-annihilation regime. The long-lived regime is, in particular, motivated by
the unexplored top partner physics. The background in this regime is extremely
challenging to model using a traditional simulation method. We demonstrate the
feasibility of handling the formidable background using the CMS Open Data. We
perform this analysis to search for compressed and long-lived top partners in
the 8 TeV CMS Open Data events with the integrated luminosity of 11.6 fb$^{-1}$
and obtain new limits. With 15-30 GeV mass splitting between the top partner
and the DM candidate, we exclude the top partner mass below 350 GeV, which is
more stringent than the ATLAS and CMS results using 8 TeV data with 20
fb$^{-1}$ luminosity. Our study also shows that the CMS Open Data can be a
powerful tool to help physicists explore non-conventional new physics and even
enable deriving new limits on exotic signals from data directly.
| [
{
"created": "Fri, 23 Jul 2021 18:16:06 GMT",
"version": "v1"
}
] | 2021-07-27 | [
[
"An",
"Haipeng",
""
],
[
"Hu",
"Zhen",
""
],
[
"Liu",
"Zhen",
""
],
[
"Yang",
"Daneng",
""
]
] | A cluster of soft displaced tracks corresponds to the dark matter co-annihilation regime. The long-lived regime is, in particular, motivated by the unexplored top partner physics. The background in this regime is extremely challenging to model using a traditional simulation method. We demonstrate the feasibility of handling the formidable background using the CMS Open Data. We perform this analysis to search for compressed and long-lived top partners in the 8 TeV CMS Open Data events with the integrated luminosity of 11.6 fb$^{-1}$ and obtain new limits. With 15-30 GeV mass splitting between the top partner and the DM candidate, we exclude the top partner mass below 350 GeV, which is more stringent than the ATLAS and CMS results using 8 TeV data with 20 fb$^{-1}$ luminosity. Our study also shows that the CMS Open Data can be a powerful tool to help physicists explore non-conventional new physics and even enable deriving new limits on exotic signals from data directly. |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.