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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
hep-ph/0701161 | Vladimir Sauli | V. Sauli, F. Kleefeld | On the absence and presence of pole(s) in fermion propagator in the
simple model with mass generation | 13 pp, references changed, introductory part condensed, results
unchanged | null | null | null | hep-ph | null | Within the Pauli-Villars regularization technique the fermion propagator is
studied in the framework of Schwinger-Dyson equations in the Euclidean space.
Making the generalization of Fukuda and Kugo proposals, the analytical
continuation is performed into the timelike region of fourmomenta. The massive
gauge boson kernel is considered and the fermion propagator pole structure is
discussed in detail.
| [
{
"created": "Fri, 19 Jan 2007 17:45:18 GMT",
"version": "v1"
},
{
"created": "Fri, 2 Feb 2007 17:42:08 GMT",
"version": "v2"
},
{
"created": "Wed, 25 Apr 2007 16:24:52 GMT",
"version": "v3"
}
] | 2007-05-23 | [
[
"Sauli",
"V.",
""
],
[
"Kleefeld",
"F.",
""
]
] | Within the Pauli-Villars regularization technique the fermion propagator is studied in the framework of Schwinger-Dyson equations in the Euclidean space. Making the generalization of Fukuda and Kugo proposals, the analytical continuation is performed into the timelike region of fourmomenta. The massive gauge boson kernel is considered and the fermion propagator pole structure is discussed in detail. |
hep-ph/9409452 | Wojtek Zakrzewski | W.J. Zakrzewski | A modified discrete sine-Gordon Model | 23pages, NI-94014 | null | 10.1088/0951-7715/8/4/004 | null | hep-ph | null | We modify the recently proposed model of Speight and Ward to make it possess
time dependent solutions. We find that for each lattice spacing and for each
velocity of the sine Gordon kink we can find a modification of the model for
which this kink is a solution. We find that this model has really 3
``kink-like" solutions; the original kink, the static kink and a further kink
moving with velocity $v\sim0.97$. We discuss various properties of the model,
from the point of view of its usefulness for numerical simulations.
| [
{
"created": "Fri, 30 Sep 1994 09:52:31 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Zakrzewski",
"W. J.",
""
]
] | We modify the recently proposed model of Speight and Ward to make it possess time dependent solutions. We find that for each lattice spacing and for each velocity of the sine Gordon kink we can find a modification of the model for which this kink is a solution. We find that this model has really 3 ``kink-like" solutions; the original kink, the static kink and a further kink moving with velocity $v\sim0.97$. We discuss various properties of the model, from the point of view of its usefulness for numerical simulations. |
2104.03276 | Shao-Feng Ge | Shao-Feng Ge and Xiao-Dong Ma and Pedro Pasquini | Probing the Dark Axion Portal with Muon Anomalous Magnetic Moment | 8 pages, 6 figures, match the EPJC version | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose a new scenario of using the dark axion portal at one-loop level to
explain the recently observed muon anomalous magnetic moment by the Fermilab
Muon g-2 experiment. Both axion/axion-like particle (ALP) and dark photon are
involved in the same vertex with photon. Although ALP or dark photon alone
cannot explain muon $g-2$, since the former provides only negative contribution
while the latter has very much constrained parameter space, dark axion portal
can save the situation and significantly extend the allowed parameter space.
The observed muon anomalous magnetic moment provides a robust probe of the dark
axion portal scenario.
| [
{
"created": "Wed, 7 Apr 2021 17:31:39 GMT",
"version": "v1"
},
{
"created": "Thu, 8 Apr 2021 13:39:03 GMT",
"version": "v2"
},
{
"created": "Thu, 30 Sep 2021 13:29:17 GMT",
"version": "v3"
}
] | 2021-10-01 | [
[
"Ge",
"Shao-Feng",
""
],
[
"Ma",
"Xiao-Dong",
""
],
[
"Pasquini",
"Pedro",
""
]
] | We propose a new scenario of using the dark axion portal at one-loop level to explain the recently observed muon anomalous magnetic moment by the Fermilab Muon g-2 experiment. Both axion/axion-like particle (ALP) and dark photon are involved in the same vertex with photon. Although ALP or dark photon alone cannot explain muon $g-2$, since the former provides only negative contribution while the latter has very much constrained parameter space, dark axion portal can save the situation and significantly extend the allowed parameter space. The observed muon anomalous magnetic moment provides a robust probe of the dark axion portal scenario. |
hep-ph/9703260 | Manuel Drees | Manuel Drees (APCTP, Seoul, Korea) | Recent Developments in Dark Matter Physics | 13 pages, LaTeX with equation.sty, no figures; invited talk given at
the 12th DAE Symposium, Guwahati, Assam, India, Dec. 1996 | null | null | APCTP 97-02 | hep-ph | null | After a short review of the arguments for the existence of Particle Dark
Matter in the Universe, I list the most plausible candidates provided by
particle physics, i.e. neutrinos, axions, and WIMPs. In each case I briefly
describe how to estimate the relic density, and discuss attempts at detecting
these particles. At the end I discuss my personal favorite, the lightest
supersymmetric particle, in a little more detail.
| [
{
"created": "Fri, 7 Mar 1997 04:29:28 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Drees",
"Manuel",
"",
"APCTP, Seoul, Korea"
]
] | After a short review of the arguments for the existence of Particle Dark Matter in the Universe, I list the most plausible candidates provided by particle physics, i.e. neutrinos, axions, and WIMPs. In each case I briefly describe how to estimate the relic density, and discuss attempts at detecting these particles. At the end I discuss my personal favorite, the lightest supersymmetric particle, in a little more detail. |
0806.1115 | Javier Redondo | Joerg Jaeckel and Javier Redondo | Searching Hidden-sector Photons inside a Superconducting Box | 7 pages, 3 figures | Europhys.Lett.84:31002,2008 | 10.1209/0295-5075/84/31002 | IPPP/08/39; DCPT/08/78; DESY-08-069 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose an experiment to search for extra "hidden-sector" U(1) gauge
bosons with gauge kinetic mixing with the ordinary photon, predicted by many
extensions of the Standard Model. The setup consists of a highly sensitive
magnetometer inside a superconducting shielding. This is then placed inside a
strong (but sub-critical) magnetic field. In ordinary electrodynamics the
magnetic field cannot permeate the superconductor and no field should register
on the magnetometer. However, photon -- hidden-sector photon -- photon
oscillations would allow to penetrate the superconductor and the magnetic field
would "leak" into the shielded volume and register on the magnetometer.
Although this setup resembles a classic ``light shining though a wall
experiment'' there are two crucial differences. First, the fields are (nearly)
static and the photons involved are virtual. Second, the magnetometer directly
measures the field-strength and not a probability. This improves the dependence
of the signal on the kinetic mixing chi (\ll 1) to chi^2 instead of chi^4. For
hidden photon masses in the range 0.002-200 meV the projected sensitivity for
the mixing parameter lies in the 5 10^-9 to 10^-6 range. This surpasses current
astrophysical and laboratory limits by several orders of magnitude -- ample
room to discover new physics.
| [
{
"created": "Fri, 6 Jun 2008 09:51:44 GMT",
"version": "v1"
}
] | 2008-12-18 | [
[
"Jaeckel",
"Joerg",
""
],
[
"Redondo",
"Javier",
""
]
] | We propose an experiment to search for extra "hidden-sector" U(1) gauge bosons with gauge kinetic mixing with the ordinary photon, predicted by many extensions of the Standard Model. The setup consists of a highly sensitive magnetometer inside a superconducting shielding. This is then placed inside a strong (but sub-critical) magnetic field. In ordinary electrodynamics the magnetic field cannot permeate the superconductor and no field should register on the magnetometer. However, photon -- hidden-sector photon -- photon oscillations would allow to penetrate the superconductor and the magnetic field would "leak" into the shielded volume and register on the magnetometer. Although this setup resembles a classic ``light shining though a wall experiment'' there are two crucial differences. First, the fields are (nearly) static and the photons involved are virtual. Second, the magnetometer directly measures the field-strength and not a probability. This improves the dependence of the signal on the kinetic mixing chi (\ll 1) to chi^2 instead of chi^4. For hidden photon masses in the range 0.002-200 meV the projected sensitivity for the mixing parameter lies in the 5 10^-9 to 10^-6 range. This surpasses current astrophysical and laboratory limits by several orders of magnitude -- ample room to discover new physics. |
hep-ph/9709345 | Andreas Vogt | Andreas Vogt (W"urzburg Univ.) | The Parton Structure of Real Photons | 14 pages LaTeX, including 6 eps-figures. Invited talk presented at
PHOTON '97, Egmond aan Zee, The Netherlands, May 1997. To appear in the
proceedings | null | null | WUE-ITP-97-036 | hep-ph | null | The QCD treatment of the photon structure is recalled. Emphasis is given to
the recently derived momentum sum rule, and to the proper choice of the
factorization scheme and/or boundary conditions for the evolution equations
beyond the leading order. Parametrizations of the photon's parton content are
examined and compared. The small-x behaviour of the photon structure is briefly
discussed.
| [
{
"created": "Mon, 15 Sep 1997 15:05:22 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Vogt",
"Andreas",
"",
"W\"urzburg Univ."
]
] | The QCD treatment of the photon structure is recalled. Emphasis is given to the recently derived momentum sum rule, and to the proper choice of the factorization scheme and/or boundary conditions for the evolution equations beyond the leading order. Parametrizations of the photon's parton content are examined and compared. The small-x behaviour of the photon structure is briefly discussed. |
hep-ph/9803304 | Gudrid Moortgat-Pick | G. Moortgat-Pick, H. Fraas, A. Bartl, W. Majerotto | Spin Effects in Neutralino Production in $e^+e^-$ Annihilation with
polarized beams | 7 pages, 8 postscript figures, latex using appb.sty (included) and
epsf.sty; Contribution to the Cracow Epiphany Conference on Spin Effects in
Particle Physics, Cracow, January 9-11 1998 | Acta Phys.Polon. B29 (1998) 1497-1504 | null | WUE-ITP-98-008 | hep-ph | null | We study the process e^+ e^- -> chi^0_1 chi^0_2 and the subsequent decay
chi^0_2 -> chi^0_1 l^{+} l^{-}$ with polarized beams, including the complete
spin correlations of chi^0_2$. We present numerical results for the lepton
energy and angular distributions, and for the distribution of the opening angle
between the leptons for sqrt{s}=500 GeV. The effects of spin correlations are
important in the lepton angular distribution, especially for gaugino-like
neutralinos. The opening angle distribution is particularly suitable for
distinguishing between higgsino- and gaugino-like neutralinos. The polarized
cross sections and lepton angular distributions are very sensitive to the
mixing of the neutralinos.
| [
{
"created": "Wed, 11 Mar 1998 13:59:22 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Moortgat-Pick",
"G.",
""
],
[
"Fraas",
"H.",
""
],
[
"Bartl",
"A.",
""
],
[
"Majerotto",
"W.",
""
]
] | We study the process e^+ e^- -> chi^0_1 chi^0_2 and the subsequent decay chi^0_2 -> chi^0_1 l^{+} l^{-}$ with polarized beams, including the complete spin correlations of chi^0_2$. We present numerical results for the lepton energy and angular distributions, and for the distribution of the opening angle between the leptons for sqrt{s}=500 GeV. The effects of spin correlations are important in the lepton angular distribution, especially for gaugino-like neutralinos. The opening angle distribution is particularly suitable for distinguishing between higgsino- and gaugino-like neutralinos. The polarized cross sections and lepton angular distributions are very sensitive to the mixing of the neutralinos. |
hep-ph/9503355 | Tanmay Vachaspati | Thomas W. Kephart and Tanmay Vachaspati | Topological Incarnations of Electroweak Defects | 12 pages + 1 figure; LaTeX | Phys.Lett.B388:481-486,1996 | 10.1016/S0370-2693(96)01179-3 | CWRU-P3-1995; VAND-TH-95-1 | hep-ph astro-ph hep-th | null | We propose a criterion to classify hybrid defects occurring in field
theoretic models such as the standard electroweak model. This criterion leads
us to consider the minimal extension of the electroweak model in which
electroweak magnetic monopoles and $Z$-strings are topological. We briefly
discuss the cosmology of such defects.
| [
{
"created": "Thu, 16 Mar 1995 18:06:44 GMT",
"version": "v1"
}
] | 2010-11-01 | [
[
"Kephart",
"Thomas W.",
""
],
[
"Vachaspati",
"Tanmay",
""
]
] | We propose a criterion to classify hybrid defects occurring in field theoretic models such as the standard electroweak model. This criterion leads us to consider the minimal extension of the electroweak model in which electroweak magnetic monopoles and $Z$-strings are topological. We briefly discuss the cosmology of such defects. |
2012.04026 | Subhojit Roy | Waleed Abdallah, AseshKrishna Datta, Subhojit Roy | A relatively light, highly bino-like dark matter in the $Z_3$-symmetric
NMSSM and recent LHC searches | 70 pages, 16 figures and 3 tables | JHEP 04 (2021) 122 | 10.1007/JHEP04(2021)122 | HRI-RECAPP-2020-10 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A highly bino-like Dark Matter (DM), which is the Lightest Supersymmetric
Particle (LSP), could be motivated by the stringent upper bounds on the DM
direct detection rates. This is especially so when its mass is around or below
100 GeV for which such a bound tends to get most severe. Requiring not so large
a higgsino mass parameter, that would render the scenario reasonably natural,
prompts such a bino-like state to be relatively light. In the Minimal
Supersymmetric Standard Model (MSSM), in the absence of comparably light
scalars, such an excitation, if it has to be a thermal relic, is unable to meet
the stringent experimental upper bound on its abundance unless its
self-annihilation hits a funnel involving either the $Z$-boson or the Standard
Model (SM)-like Higgs boson. We demonstrate that, in such a realistic
situation, a highly bino-like DM of the popular $Z_3$-symmetric Next-to-Minimal
Supersymmetric Standard Model (NMSSM) is viable over an extended range of its
mass, from our targeted maximum in the vicinity of the mass of the top quark
down to about 30 GeV. This is facilitated by the presence of comparably light
singlet-like states that could serve as funnel (scalars) and/or coannihilating
(singlino) states even as the bino-like LSP receives a minimal (but optimal)
tempering triggered by suitably light higgsino states that, in the first place,
evade stringent lower bounds on their masses that can be derived from the Large
Hadron Collider (LHC) experiments only in the presence of a lighter
singlino-like state. An involved set of blind spot conditions is derived for
the DM direct detection rates by considering for the very first time the
augmented system of neutralinos comprising of the bino, the higgsinos and the
singlino which highlights the important roles played by the NMSSM parameters
$\lambda$ and $\tan\beta$ in delivering a richer phenomenology.
| [
{
"created": "Mon, 7 Dec 2020 20:04:03 GMT",
"version": "v1"
}
] | 2023-02-06 | [
[
"Abdallah",
"Waleed",
""
],
[
"Datta",
"AseshKrishna",
""
],
[
"Roy",
"Subhojit",
""
]
] | A highly bino-like Dark Matter (DM), which is the Lightest Supersymmetric Particle (LSP), could be motivated by the stringent upper bounds on the DM direct detection rates. This is especially so when its mass is around or below 100 GeV for which such a bound tends to get most severe. Requiring not so large a higgsino mass parameter, that would render the scenario reasonably natural, prompts such a bino-like state to be relatively light. In the Minimal Supersymmetric Standard Model (MSSM), in the absence of comparably light scalars, such an excitation, if it has to be a thermal relic, is unable to meet the stringent experimental upper bound on its abundance unless its self-annihilation hits a funnel involving either the $Z$-boson or the Standard Model (SM)-like Higgs boson. We demonstrate that, in such a realistic situation, a highly bino-like DM of the popular $Z_3$-symmetric Next-to-Minimal Supersymmetric Standard Model (NMSSM) is viable over an extended range of its mass, from our targeted maximum in the vicinity of the mass of the top quark down to about 30 GeV. This is facilitated by the presence of comparably light singlet-like states that could serve as funnel (scalars) and/or coannihilating (singlino) states even as the bino-like LSP receives a minimal (but optimal) tempering triggered by suitably light higgsino states that, in the first place, evade stringent lower bounds on their masses that can be derived from the Large Hadron Collider (LHC) experiments only in the presence of a lighter singlino-like state. An involved set of blind spot conditions is derived for the DM direct detection rates by considering for the very first time the augmented system of neutralinos comprising of the bino, the higgsinos and the singlino which highlights the important roles played by the NMSSM parameters $\lambda$ and $\tan\beta$ in delivering a richer phenomenology. |
hep-ph/9211290 | Krishna Rajagopal | Frank Wilczek | QCD and Asymptotic Freedom: Perspectives and Prospects | 37 pages, phyzzx, IASSNS-HEP-92/79 | Int.J.Mod.Phys. A8 (1993) 1359-1382 | 10.1142/S0217751X93000564 | null | hep-ph hep-th | null | QCD is now a mature theory, and it is possible to begin to view its place in
the conceptual universe of physics with appropriate perspective. There is a
certain irony in the achievements of QCD. For the problems which initially
drove its development only limited insight has been achieved. However I shall
argue that QCD is actually {\it more\/} special and important a theory than one
had any right to anticipate. After elaborating these quasi-philosophical
remarks, I discuss two current frontiers of physics that illustrate the
continuing vitality of the ideas. The recent wealth of beautiful precision
experiments measuring the parameters of the standard model has made it possible
to consider the unification of couplings in unprecedented quantitative detail.
One central result emerging from these developments is a tantalizing hint of
virtual supersymmetry. The possibility of phase transitions in matter at
temperatures of order $\sim 10^2 Mev$, governed by QCD dynamics, is of interest
from several points of view. There is the interesting possibility of long-range
correlations in heavy ion collisions due to the creation of large regions of
misaligned chiral condensate. Opening Talk at the Aachen conference, ``20 Years
of QCD'', June 1992.
| [
{
"created": "Fri, 20 Nov 1992 22:16:35 GMT",
"version": "v1"
}
] | 2009-10-22 | [
[
"Wilczek",
"Frank",
""
]
] | QCD is now a mature theory, and it is possible to begin to view its place in the conceptual universe of physics with appropriate perspective. There is a certain irony in the achievements of QCD. For the problems which initially drove its development only limited insight has been achieved. However I shall argue that QCD is actually {\it more\/} special and important a theory than one had any right to anticipate. After elaborating these quasi-philosophical remarks, I discuss two current frontiers of physics that illustrate the continuing vitality of the ideas. The recent wealth of beautiful precision experiments measuring the parameters of the standard model has made it possible to consider the unification of couplings in unprecedented quantitative detail. One central result emerging from these developments is a tantalizing hint of virtual supersymmetry. The possibility of phase transitions in matter at temperatures of order $\sim 10^2 Mev$, governed by QCD dynamics, is of interest from several points of view. There is the interesting possibility of long-range correlations in heavy ion collisions due to the creation of large regions of misaligned chiral condensate. Opening Talk at the Aachen conference, ``20 Years of QCD'', June 1992. |
hep-ph/9612383 | Paolo Ciafaloni | P. Ciafaloni and D. Espriu | The Effective Lagrangian of the Two Higgs Doublet Model | 16 pages, LaTeX, 2 figures | Phys.Rev. D56 (1997) 1752-1760 | 10.1103/PhysRevD.56.1752 | UAB-FT-405, UB-ECM-PF-96/23 | hep-ph | null | We consider the two Higgs doublet model extension of the Standard Model in
the limit where all physical scalar particles are very heavy; too heavy, in
fact, to be experimentally produced in forthcoming experiments. The symmetry
breaking sector can thus be described by an effective chiral Lagrangian. We
obtain the values of the coefficients of the O(p^4) operators relevant to the
oblique corrections and investigate to what extent some non-decoupling effects
may remain at low energies.
| [
{
"created": "Tue, 17 Dec 1996 14:50:10 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Ciafaloni",
"P.",
""
],
[
"Espriu",
"D.",
""
]
] | We consider the two Higgs doublet model extension of the Standard Model in the limit where all physical scalar particles are very heavy; too heavy, in fact, to be experimentally produced in forthcoming experiments. The symmetry breaking sector can thus be described by an effective chiral Lagrangian. We obtain the values of the coefficients of the O(p^4) operators relevant to the oblique corrections and investigate to what extent some non-decoupling effects may remain at low energies. |
hep-ph/0311124 | Boikova Natalia A. | N. A. Boikova, Y. N. Tyukhtyaev, R. N. Faustov | On The Method of Precise Calculations Of Energy Levels of Hydrogen-like
Atoms | null | null | null | null | hep-ph | null | We describe a method for deriving logarithmic corrections in the mass ratio
to the S-level of a hydrogen-like atom. With this method, a number of new
corrections of this type are calculated analitically for the first time.
| [
{
"created": "Mon, 10 Nov 2003 17:22:18 GMT",
"version": "v1"
},
{
"created": "Sat, 22 Nov 2003 12:53:08 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Boikova",
"N. A.",
""
],
[
"Tyukhtyaev",
"Y. N.",
""
],
[
"Faustov",
"R. N.",
""
]
] | We describe a method for deriving logarithmic corrections in the mass ratio to the S-level of a hydrogen-like atom. With this method, a number of new corrections of this type are calculated analitically for the first time. |
hep-ph/0402155 | Isabella Masina | Guido Altarelli, Ferruccio Feruglio, Isabella Masina | Can Neutrino Mixings Arise from the Charged Lepton Sector? | v1: 16 pages, 3 figures; v2: added references and corrected misprints | Nucl.Phys. B689 (2004) 157-171 | 10.1016/j.nuclphysb.2004.04.012 | null | hep-ph | null | The neutrino mixing matrix U is in general of the form U=U_e^+ U_nu, where
U_e arises from the diagonalization of charged leptons and U_nu is from the
neutrino sector. We discuss the possibility that U_nu is nearly diagonal (in
the lagrangian basis) and the observed mixing arises with good accuracy from
U_e. We find that the fact that, in addition to the nearly maximal atmospheric
mixing angle theta_{23}, the solar angle theta_{12} is definitely also large
while at the same time the third mixing angle theta_{13} is small, makes the
construction of a natural model of this sort considerably more complicated. We
present an example of a natural model of this class. We also find that the case
that U_nu is exactly of the bimixing type is severely constrained by the bound
on theta_{13} but not excluded. We show that planned experimental searches for
theta_{13} could have a strong impact on bimixing models.
| [
{
"created": "Sat, 14 Feb 2004 17:13:37 GMT",
"version": "v1"
},
{
"created": "Tue, 23 Mar 2004 16:58:26 GMT",
"version": "v2"
}
] | 2010-04-05 | [
[
"Altarelli",
"Guido",
""
],
[
"Feruglio",
"Ferruccio",
""
],
[
"Masina",
"Isabella",
""
]
] | The neutrino mixing matrix U is in general of the form U=U_e^+ U_nu, where U_e arises from the diagonalization of charged leptons and U_nu is from the neutrino sector. We discuss the possibility that U_nu is nearly diagonal (in the lagrangian basis) and the observed mixing arises with good accuracy from U_e. We find that the fact that, in addition to the nearly maximal atmospheric mixing angle theta_{23}, the solar angle theta_{12} is definitely also large while at the same time the third mixing angle theta_{13} is small, makes the construction of a natural model of this sort considerably more complicated. We present an example of a natural model of this class. We also find that the case that U_nu is exactly of the bimixing type is severely constrained by the bound on theta_{13} but not excluded. We show that planned experimental searches for theta_{13} could have a strong impact on bimixing models. |
2106.06390 | Gabriel Niculescu | S. Brown, G. Niculescu, I. Niculescu | inclusiveAI: A machine learning representation of the $F_2$ structure
function over all charted $Q^2$ and $x$ range | null | null | 10.1103/PhysRevC.104.064321 | null | hep-ph nucl-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Structure function data provide insight into the nucleon quark distribution.
They are relatively straightforward to extract from the world's vast, and
growing, amount of inclusive lepto-production data. In turn, structure
functions can be used to model the physical processes needed for planning and
optimizing future experiments. In this paper a machine learning algorithm
capable of predicting, using a unique set of parameters, the $F_2$ structure
function, for four-momentum transfer $0.055 \leq Q^2 \leq 800.0$ GeV$^2$ and
for Bjorken $x$ from $2.8 \times 10^{-5}$ to the pion threshold is presented.
The model was trained and reproduces the hydrogen and the deuterium data at the
7~\% level, comparable with the average uncertainty of the experimental data.
Extending the model to other nuclei or expanding the kinematic range are
straightforward. The model is at least ten times faster than existing structure
functions parameterizations, making it an ideal candidate for event generators
and systematic studies.
| [
{
"created": "Fri, 11 Jun 2021 13:50:07 GMT",
"version": "v1"
},
{
"created": "Tue, 29 Jun 2021 17:54:50 GMT",
"version": "v2"
}
] | 2022-01-05 | [
[
"Brown",
"S.",
""
],
[
"Niculescu",
"G.",
""
],
[
"Niculescu",
"I.",
""
]
] | Structure function data provide insight into the nucleon quark distribution. They are relatively straightforward to extract from the world's vast, and growing, amount of inclusive lepto-production data. In turn, structure functions can be used to model the physical processes needed for planning and optimizing future experiments. In this paper a machine learning algorithm capable of predicting, using a unique set of parameters, the $F_2$ structure function, for four-momentum transfer $0.055 \leq Q^2 \leq 800.0$ GeV$^2$ and for Bjorken $x$ from $2.8 \times 10^{-5}$ to the pion threshold is presented. The model was trained and reproduces the hydrogen and the deuterium data at the 7~\% level, comparable with the average uncertainty of the experimental data. Extending the model to other nuclei or expanding the kinematic range are straightforward. The model is at least ten times faster than existing structure functions parameterizations, making it an ideal candidate for event generators and systematic studies. |
0903.4312 | Andre Sopczak | Andre Sopczak | Status of Higgs Boson Searches at the Tevatron | Presented at WONP'09, 18 pages, 38 figures | null | null | FERMILAB-CONF-09-088-E-PPD-T | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Over the last years the Tevatron Run-II has extended several limits on Higgs
boson masses and coupling which were pioneered during the LEP accelerator
operation between 1989 and 2000. Higgs boson searches will also be at the
forefront of research at the LHC. This review concisely discusses the
experimental constraints set by the CDF and D0 collaborations in winter
2008/2009 at the beginning of the LHC era. Model-independent and
model-dependent limits on Higgs boson masses and couplings have been set and
interpretations are discussed both in the Standard Model and in extended
models. Recently, for the first time the Tevatron excludes a SM Higgs boson
mass range (160-170 GeV) beyond the LEP limit at 95% CL. The experimental
sensitivities are estimated for the completion of the Tevatron programme.
| [
{
"created": "Wed, 25 Mar 2009 21:24:21 GMT",
"version": "v1"
}
] | 2009-03-26 | [
[
"Sopczak",
"Andre",
""
]
] | Over the last years the Tevatron Run-II has extended several limits on Higgs boson masses and coupling which were pioneered during the LEP accelerator operation between 1989 and 2000. Higgs boson searches will also be at the forefront of research at the LHC. This review concisely discusses the experimental constraints set by the CDF and D0 collaborations in winter 2008/2009 at the beginning of the LHC era. Model-independent and model-dependent limits on Higgs boson masses and couplings have been set and interpretations are discussed both in the Standard Model and in extended models. Recently, for the first time the Tevatron excludes a SM Higgs boson mass range (160-170 GeV) beyond the LEP limit at 95% CL. The experimental sensitivities are estimated for the completion of the Tevatron programme. |
hep-ph/0502130 | Gino Isidori | Nicola Cabibbo and Gino Isidori | Pion-pion scattering and the K->3pi decay amplitudes | 32 pages, 6 figures | JHEP0503:021,2005 | 10.1088/1126-6708/2005/03/021 | CERN-PH-TH/2005-012 | hep-ph | null | We revisit the recently proposed method for the determination of the pi-pi
scattering length combination a_{0}-a_{2}, based on the study of the pi0 pi0
spectrum in K+ -> pi+ pi0 pi0. In view of a precision measurement, we discuss
here the effects due to smaller absorptive contributions to the K+ -> pi+ pi0
pi0 and K+ -> pi+ pi+ pi- amplitudes. We outline a method of analysis that can
lead to a precision determination of a_{0}-a_{2} and is based on very general
properties of the S matrix. The discussion of final-state rescattering and cusp
effects is also extended to the two K_L -> 3pi coupled channels. Thanks to the
present work, the theoretical error on the a_{0}-a_{2} combination extracted
from the K+ -> pi+ pi0 pi0 spectrum is reduced to about 5%. A further reduction
requires the evaluation of the effects arising from radiative corrections.
| [
{
"created": "Mon, 14 Feb 2005 16:43:18 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Cabibbo",
"Nicola",
""
],
[
"Isidori",
"Gino",
""
]
] | We revisit the recently proposed method for the determination of the pi-pi scattering length combination a_{0}-a_{2}, based on the study of the pi0 pi0 spectrum in K+ -> pi+ pi0 pi0. In view of a precision measurement, we discuss here the effects due to smaller absorptive contributions to the K+ -> pi+ pi0 pi0 and K+ -> pi+ pi+ pi- amplitudes. We outline a method of analysis that can lead to a precision determination of a_{0}-a_{2} and is based on very general properties of the S matrix. The discussion of final-state rescattering and cusp effects is also extended to the two K_L -> 3pi coupled channels. Thanks to the present work, the theoretical error on the a_{0}-a_{2} combination extracted from the K+ -> pi+ pi0 pi0 spectrum is reduced to about 5%. A further reduction requires the evaluation of the effects arising from radiative corrections. |
1301.6455 | Koji Tsumura | Junji Hisano, Koji Tsumura | The Higgs boson mixes with an SU(2) septet representation | 14 pages, 13 eps files | null | 10.1103/PhysRevD.87.053004 | IPMU13-0022 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study a possibility of the Higgs boson, which consists of an SU(2) doublet
and a septet. The vacuum expectation value of a septet with hypercharge Y=2 is
known to preserve the electroweak rho parameter unity at the tree level.
Therefore, the septet can give significant contribution to the electroweak
symmetry breaking. Due to the mixing with the septet, the gauge coupling of the
standard-model-like Higgs boson is larger than that in the standard model. We
show the sizable VEV of the Higgs septet can be allowed under the constraint
from the electroweak precision data. The signal strengths of the Higgs boson
for the diphoton and a pair of weak gauge boson decay channels at the LHC are
enhanced, while those for the fermonic decay modes are suppressed. The mass of
additional neutral Higgs boson is also bounded by the current LHC data for the
standard model Higgs boson. We discussed the phenomenology of the multiply
charged Higgs bosons, which come from the septet.
| [
{
"created": "Mon, 28 Jan 2013 06:23:26 GMT",
"version": "v1"
}
] | 2013-08-05 | [
[
"Hisano",
"Junji",
""
],
[
"Tsumura",
"Koji",
""
]
] | We study a possibility of the Higgs boson, which consists of an SU(2) doublet and a septet. The vacuum expectation value of a septet with hypercharge Y=2 is known to preserve the electroweak rho parameter unity at the tree level. Therefore, the septet can give significant contribution to the electroweak symmetry breaking. Due to the mixing with the septet, the gauge coupling of the standard-model-like Higgs boson is larger than that in the standard model. We show the sizable VEV of the Higgs septet can be allowed under the constraint from the electroweak precision data. The signal strengths of the Higgs boson for the diphoton and a pair of weak gauge boson decay channels at the LHC are enhanced, while those for the fermonic decay modes are suppressed. The mass of additional neutral Higgs boson is also bounded by the current LHC data for the standard model Higgs boson. We discussed the phenomenology of the multiply charged Higgs bosons, which come from the septet. |
2404.13546 | Bhag C. Chauhan | Rishu Verma, Ankush and B. C. Chauhan | Electron and Muon $(g-2)_{e,\mu}$ Anomalous Magnetic Moment in
$U(1)_{L_e-L_{\mu}}$ Symmetry Model | 13 pages, 10 figures and 2 tables | null | null | null | hep-ph | http://creativecommons.org/licenses/by-sa/4.0/ | The nature of neutrino (whether Majorana or Dirac) and the origin of neutrino
masses are still some of the mysteries to be resolved. Also, the recent results
on (g-2)$_{e,\mu}$ measurements deviate from the Standard Model (SM)
predictions and motivate us towards new physics beyond the SM. In this work, we
propose a model with the minimal field content in the framework of anomaly free
extension of Standard Model; i.e. U(1)$_{L_e-L_{\mu}}$ symmetry model. We find
this model capable of explaining the low energy neutrino phenomenology and
anomalous magnetic moment(g-2)$_{e,\mu}$ of electron and muon, simultaneously.
The field content is extended by a SU(2)$_L$ singlet scalar field $\phi$ and
three right handed neutrinos N$_R$(R = 1,2,3). Thus, the neutrino masses are
generated using the Type-I seesaw mechanism. The extended model leads to the
results, which are in consistency with the experimental values of
(g-2)$_{e,\mu}$ and also satisfy all the relevant experimental data.
| [
{
"created": "Sun, 21 Apr 2024 06:02:55 GMT",
"version": "v1"
}
] | 2024-04-23 | [
[
"Verma",
"Rishu",
""
],
[
"Ankush",
"",
""
],
[
"Chauhan",
"B. C.",
""
]
] | The nature of neutrino (whether Majorana or Dirac) and the origin of neutrino masses are still some of the mysteries to be resolved. Also, the recent results on (g-2)$_{e,\mu}$ measurements deviate from the Standard Model (SM) predictions and motivate us towards new physics beyond the SM. In this work, we propose a model with the minimal field content in the framework of anomaly free extension of Standard Model; i.e. U(1)$_{L_e-L_{\mu}}$ symmetry model. We find this model capable of explaining the low energy neutrino phenomenology and anomalous magnetic moment(g-2)$_{e,\mu}$ of electron and muon, simultaneously. The field content is extended by a SU(2)$_L$ singlet scalar field $\phi$ and three right handed neutrinos N$_R$(R = 1,2,3). Thus, the neutrino masses are generated using the Type-I seesaw mechanism. The extended model leads to the results, which are in consistency with the experimental values of (g-2)$_{e,\mu}$ and also satisfy all the relevant experimental data. |
0806.0213 | Naoki Yamatsu | Kenzo Inoue, Naoki Yamatsu | Strong CP Problem and the Natural Hierarchy of Yukawa Couplings | 31 pages, no figures | Prog.Theor.Phys.120:1065-1091,2008 | 10.1143/PTP.120.1065 | KYUSHU-HET-114 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A possible solution to the strong CP problem is presented without using an
axion. The model is based on the framework of the supersymmetric vectorlike
theory with the spontaneous breakdown of the P-C-T-invariance. It is shown that
the characteristic structure of the Yukawa coupling matrices that results from
the spontaneous P-C-T-breaking plays the essential role in naturally realizing
$\theta=0$ at the tree level. It is argued that $\theta=0$ will not be affected
by the radiative corrections.
| [
{
"created": "Mon, 2 Jun 2008 06:38:55 GMT",
"version": "v1"
},
{
"created": "Wed, 20 Aug 2008 05:24:54 GMT",
"version": "v2"
}
] | 2008-12-25 | [
[
"Inoue",
"Kenzo",
""
],
[
"Yamatsu",
"Naoki",
""
]
] | A possible solution to the strong CP problem is presented without using an axion. The model is based on the framework of the supersymmetric vectorlike theory with the spontaneous breakdown of the P-C-T-invariance. It is shown that the characteristic structure of the Yukawa coupling matrices that results from the spontaneous P-C-T-breaking plays the essential role in naturally realizing $\theta=0$ at the tree level. It is argued that $\theta=0$ will not be affected by the radiative corrections. |
1712.05165 | Gavin Salam | Gavin P. Salam | The strong coupling: a theoretical perspective | 24 pages, 3 figures; v2 adds clarifications and further references | null | null | CERN-TH-2017-268 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This contribution to the volume "From My Vast Repertoire - The Legacy of
Guido Altarelli" discusses the state of our knowledge of the strong coupling.
| [
{
"created": "Thu, 14 Dec 2017 11:00:24 GMT",
"version": "v1"
},
{
"created": "Wed, 20 Dec 2017 16:35:13 GMT",
"version": "v2"
}
] | 2017-12-21 | [
[
"Salam",
"Gavin P.",
""
]
] | This contribution to the volume "From My Vast Repertoire - The Legacy of Guido Altarelli" discusses the state of our knowledge of the strong coupling. |
hep-ph/0609179 | Alexander Belyaev | Alexander Belyaev, Chuan-Ren Chen, Kazuhiro Tobe, C.-P. Yuan | Phenomenology of Littlest Higgs Model with T-parity: including effects
of T-odd fermions | null | Phys.Rev.D74:115020,2006 | 10.1103/PhysRevD.74.115020 | MSUHEP-060915 | hep-ph | null | We study the collider phenomenology of a Littlest Higgs model with T-parity.
We first stress the important role of the T-odd SU(2) doublet fermions
(introduced to make the model T-parity invariant) in high energy scattering
processes, such as $q\bar{q}\to W_H^+ W_H^-$ where $W_H^\pm$ are the T-odd
partners of $W$-bosons. Because the mass of the T-odd SU(2) doublet fermions
cannot be too heavy to be consistent with low energy data, they can be
copiously produced at the CERN Large Hadron Collider (LHC). Therefore, we study
the collider phenomenology of the model with emphasis on the contributions of
the T-odd fermion to the production of the heavy T-parity partners (either
bosons or fermions) of the usual particles at the LHC. The production cross
sections and the decay branching ratios of the new heavy particles are
classified and various experimental signatures are discussed.
| [
{
"created": "Tue, 19 Sep 2006 19:58:29 GMT",
"version": "v1"
},
{
"created": "Wed, 17 Jan 2007 19:57:12 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Belyaev",
"Alexander",
""
],
[
"Chen",
"Chuan-Ren",
""
],
[
"Tobe",
"Kazuhiro",
""
],
[
"Yuan",
"C. -P.",
""
]
] | We study the collider phenomenology of a Littlest Higgs model with T-parity. We first stress the important role of the T-odd SU(2) doublet fermions (introduced to make the model T-parity invariant) in high energy scattering processes, such as $q\bar{q}\to W_H^+ W_H^-$ where $W_H^\pm$ are the T-odd partners of $W$-bosons. Because the mass of the T-odd SU(2) doublet fermions cannot be too heavy to be consistent with low energy data, they can be copiously produced at the CERN Large Hadron Collider (LHC). Therefore, we study the collider phenomenology of the model with emphasis on the contributions of the T-odd fermion to the production of the heavy T-parity partners (either bosons or fermions) of the usual particles at the LHC. The production cross sections and the decay branching ratios of the new heavy particles are classified and various experimental signatures are discussed. |
1810.08318 | Long-Cheng Gui | Zuo-Yun Wang, Long-Cheng Gui, Qi-Fang L\"u, Li-Ye Xiao and Xian-Hui
Zhong | Newly observed $\Omega(2012)$ state and strong decays of the low-lying
$\Omega$ excitations | null | Phys. Rev. D 98, 114023 (2018) | 10.1103/PhysRevD.98.114023 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Stimulated by the newly discovered $\Omega(2012)$ resonance at Belle II, in
this work we have studied the OZI allowed strong decays of the low-lying $1P$-
and $1D$-wave $\Omega$ baryons within the $^3P_0$ model. It is found that
$\Omega(2012)$ is most likely to be a $1P$-wave $\Omega$ state with
$J^P=3/2^-$. We also find that the $\Omega(2250)$ state could be assigned as a
$1D$-wave state with $J^P=5/2^+$. The other missing $1P$- and $1D$-wave
$\Omega$ baryons may have large potentials to be observed in their main decay
channels.
| [
{
"created": "Fri, 19 Oct 2018 00:36:18 GMT",
"version": "v1"
},
{
"created": "Tue, 23 Oct 2018 01:23:22 GMT",
"version": "v2"
}
] | 2018-12-26 | [
[
"Wang",
"Zuo-Yun",
""
],
[
"Gui",
"Long-Cheng",
""
],
[
"Lü",
"Qi-Fang",
""
],
[
"Xiao",
"Li-Ye",
""
],
[
"Zhong",
"Xian-Hui",
""
]
] | Stimulated by the newly discovered $\Omega(2012)$ resonance at Belle II, in this work we have studied the OZI allowed strong decays of the low-lying $1P$- and $1D$-wave $\Omega$ baryons within the $^3P_0$ model. It is found that $\Omega(2012)$ is most likely to be a $1P$-wave $\Omega$ state with $J^P=3/2^-$. We also find that the $\Omega(2250)$ state could be assigned as a $1D$-wave state with $J^P=5/2^+$. The other missing $1P$- and $1D$-wave $\Omega$ baryons may have large potentials to be observed in their main decay channels. |
1205.1444 | Alexander Lenz | Alexander Lenz | Theoretical update of $B$-Mixing and Lifetimes | Based on talks given at Moriond Electroweak 2012, at Nikhef, in
Trento and at CERN; 28 pages; 2 typos corrected | null | null | CERN-PH-TH/2012-111 | hep-ph hep-ex hep-lat | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We review the current status of theoretical predictions for mixing quantities
and lifetimes in the $B$-sector. In particular, due to the first non-zero
measurement of the decay rate difference in the neutral $B_s$-system, $\Delta
\Gamma_s/ \Gamma_s = 17.6 % \pm 2.9 %$ by the LHCb collaboration and very
precise data for $\tau_{B_s}$ from TeVatron and LHCb our theoretical tools can
now be rigorously tested and it turns out that the Heavy Quark Expansion works
in the $B$-system to an accuracy of at least 30% for quantities like
$\Gamma_{12}$, which is most sensitive to hypothetical violations of quark
hadron duality. This issue that gave rise in the past to numerous theoretical
papers, has now been settled experimentally. Further data will even allow to
shrink this bound. For total inclusive quantities like lifetimes the compliance
is even more astonishing: $\tau_{B_s}^{\rm LHCb}/ \tau_{B_d}^{\rm HFAG} = 1.001
\pm 0.014$ is in perfect agreement with the theory expectation of
$\tau_{B_s}/\tau_{B_d} = 0.996 ... 1.000$. Despite the fact that the new data
show no deviations from the standard model expectations, there is still some
sizable room for new physics effects. Model-independent search strategies for
these effects are presented with an emphasis on the interconnection with many
different observables that have to be taken into account. In that respect a
special emphasis is given to the large value of the di-muon asymmetry measured
by the D0 collaboration.
| [
{
"created": "Mon, 7 May 2012 16:06:56 GMT",
"version": "v1"
},
{
"created": "Sun, 1 Jul 2012 16:09:13 GMT",
"version": "v2"
}
] | 2012-07-03 | [
[
"Lenz",
"Alexander",
""
]
] | We review the current status of theoretical predictions for mixing quantities and lifetimes in the $B$-sector. In particular, due to the first non-zero measurement of the decay rate difference in the neutral $B_s$-system, $\Delta \Gamma_s/ \Gamma_s = 17.6 % \pm 2.9 %$ by the LHCb collaboration and very precise data for $\tau_{B_s}$ from TeVatron and LHCb our theoretical tools can now be rigorously tested and it turns out that the Heavy Quark Expansion works in the $B$-system to an accuracy of at least 30% for quantities like $\Gamma_{12}$, which is most sensitive to hypothetical violations of quark hadron duality. This issue that gave rise in the past to numerous theoretical papers, has now been settled experimentally. Further data will even allow to shrink this bound. For total inclusive quantities like lifetimes the compliance is even more astonishing: $\tau_{B_s}^{\rm LHCb}/ \tau_{B_d}^{\rm HFAG} = 1.001 \pm 0.014$ is in perfect agreement with the theory expectation of $\tau_{B_s}/\tau_{B_d} = 0.996 ... 1.000$. Despite the fact that the new data show no deviations from the standard model expectations, there is still some sizable room for new physics effects. Model-independent search strategies for these effects are presented with an emphasis on the interconnection with many different observables that have to be taken into account. In that respect a special emphasis is given to the large value of the di-muon asymmetry measured by the D0 collaboration. |
1206.4365 | Guy F. de T\'eramond | Guy F. de Teramond and Stanley J. Brodsky | Light-front holography - A new approach to relativistic hadron dynamics
and nonperturbative QCD | Presented by GdT at the Sixth International Conference on Quarks and
Nuclear Physics, Ecole Polytechnique, Palaiseau, Paris, April 16-20, 2012 | null | null | SLAC-PUB-15094 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The holographic mapping of gravity in AdS space to QCD, quantized at fixed
light-front time, provides a precise relation between the bound-state
amplitudes in the fifth dimension of AdS space and the boost-invariant
light-front wavefunctions describing the internal structure of hadrons in
physical space-time. In particular, the elastic and transition form factors of
the pion and the nucleons are well described in this framework. The light-front
AdS/QCD holographic approach thus gives a frame-independent first approximation
of the color-confining dynamics, spectroscopy, and excitation spectra of
relativistic light-quark bound states in QCD. More generally, we show that the
valence Fock-state wavefunctions of the eigensolutions of the light-front QCD
Hamiltonian satisfy a single-variable relativistic equation of motion,
analogous to the nonrelativistic radial Schr\"odinger equation, with an
effective confining potential which systematically incorporates the effects of
higher quark and gluon Fock states. The proposed method to compute the
effective interaction thus resembles the two-particle-irreducible functional
techniques used in quantum field theory.
| [
{
"created": "Wed, 20 Jun 2012 01:02:36 GMT",
"version": "v1"
},
{
"created": "Thu, 5 Jul 2012 15:15:13 GMT",
"version": "v2"
}
] | 2012-07-06 | [
[
"de Teramond",
"Guy F.",
""
],
[
"Brodsky",
"Stanley J.",
""
]
] | The holographic mapping of gravity in AdS space to QCD, quantized at fixed light-front time, provides a precise relation between the bound-state amplitudes in the fifth dimension of AdS space and the boost-invariant light-front wavefunctions describing the internal structure of hadrons in physical space-time. In particular, the elastic and transition form factors of the pion and the nucleons are well described in this framework. The light-front AdS/QCD holographic approach thus gives a frame-independent first approximation of the color-confining dynamics, spectroscopy, and excitation spectra of relativistic light-quark bound states in QCD. More generally, we show that the valence Fock-state wavefunctions of the eigensolutions of the light-front QCD Hamiltonian satisfy a single-variable relativistic equation of motion, analogous to the nonrelativistic radial Schr\"odinger equation, with an effective confining potential which systematically incorporates the effects of higher quark and gluon Fock states. The proposed method to compute the effective interaction thus resembles the two-particle-irreducible functional techniques used in quantum field theory. |
1805.12578 | Daniele Barducci | Daniele Barducci, Stefania De Curtis, Michele Redi, Andrea Tesi | An almost elementary Higgs: Theory and Practice | 29 pages, 9 figures. Typos corrected, references added, matches the
published version | null | 10.1007/JHEP08(2018)017 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study models that interpolate between an elementary and a composite Higgs
boson. Such models, arising in theories with new vector-like fermions with
electro-weak quantum numbers and charged under a confining gauge interaction,
are entirely compatible with current data, with only weak bounds from flavor,
CP-violation and precision tests. After classifying the models from the point
of view of symmetries, we study their collider phenomenology at LHC. In the
most relevant scenarios, bounds from present searches exclude heavy scalar
isospin triplets and quintuplets up to $\sim 200\;$GeV and we show how
dedicated searches of simple signals such as $pp\to 3 \gamma W$ could improve
the reach by at least a factor of 2 with present data, reaching $O(1\;{\rm
TeV})$ with higher integrated luminosities. States that mix with the SM Higgs
can be tested in a variety of final states, such as $2b2\gamma$ searches
relevant for double Higgs production.
| [
{
"created": "Thu, 31 May 2018 17:39:51 GMT",
"version": "v1"
},
{
"created": "Wed, 25 Jul 2018 19:20:58 GMT",
"version": "v2"
}
] | 2018-08-29 | [
[
"Barducci",
"Daniele",
""
],
[
"De Curtis",
"Stefania",
""
],
[
"Redi",
"Michele",
""
],
[
"Tesi",
"Andrea",
""
]
] | We study models that interpolate between an elementary and a composite Higgs boson. Such models, arising in theories with new vector-like fermions with electro-weak quantum numbers and charged under a confining gauge interaction, are entirely compatible with current data, with only weak bounds from flavor, CP-violation and precision tests. After classifying the models from the point of view of symmetries, we study their collider phenomenology at LHC. In the most relevant scenarios, bounds from present searches exclude heavy scalar isospin triplets and quintuplets up to $\sim 200\;$GeV and we show how dedicated searches of simple signals such as $pp\to 3 \gamma W$ could improve the reach by at least a factor of 2 with present data, reaching $O(1\;{\rm TeV})$ with higher integrated luminosities. States that mix with the SM Higgs can be tested in a variety of final states, such as $2b2\gamma$ searches relevant for double Higgs production. |
2207.01775 | Shintaro Eijima | Shintaro Eijima, Osamu Seto and Takashi Shimomura | Revisiting sterile neutrino dark matter in gauged $U(1)_{B-L}$ model | 29 pages, 8 figures, Published version | Phys. Rev. D 106, 103513 (2022) | 10.1103/PhysRevD.106.103513 | UME-PP-021, EPHOU-22-013, KYUSHU-HET-244 | hep-ph astro-ph.CO | http://creativecommons.org/licenses/by/4.0/ | We reexamine sterile neutrino dark matter in gauged $U(1)_{B-L}$ model.
Improvements have been made by tracing and careful evaluation of the evolution
of the number densities of sterile neutrinos $N$ and extra neutral gauge bosons
$Z'$. As a result, the cosmologically-interesting gauge coupling of
$U(1)_{B-L}$ for freeze-in sterile neutrinos turns out to be smaller than the
values reported in the literature. This avoids the overproduction of $Z'$ so
that it is consistent with the big bang nucleosynthesis and the cosmic
microwave background constraints on the effective number of neutrino species.
Similarly, the free-streaming length constraints exclude a large parameter
space derived in previous studies. In addition to known freeze-in pair
production of $N$ from the standard model fermion pairs, we find the case that
$N$ is dominantly produced from a pair of $Z'$ at the temperature characterized
by the $B-L$ breaking scalar mass. Thus, the naive truncation of the
$U(1)_{B-L}$ scalar contribution made in the literature is not valid.
| [
{
"created": "Tue, 5 Jul 2022 02:24:05 GMT",
"version": "v1"
},
{
"created": "Wed, 16 Nov 2022 07:12:48 GMT",
"version": "v2"
}
] | 2022-11-30 | [
[
"Eijima",
"Shintaro",
""
],
[
"Seto",
"Osamu",
""
],
[
"Shimomura",
"Takashi",
""
]
] | We reexamine sterile neutrino dark matter in gauged $U(1)_{B-L}$ model. Improvements have been made by tracing and careful evaluation of the evolution of the number densities of sterile neutrinos $N$ and extra neutral gauge bosons $Z'$. As a result, the cosmologically-interesting gauge coupling of $U(1)_{B-L}$ for freeze-in sterile neutrinos turns out to be smaller than the values reported in the literature. This avoids the overproduction of $Z'$ so that it is consistent with the big bang nucleosynthesis and the cosmic microwave background constraints on the effective number of neutrino species. Similarly, the free-streaming length constraints exclude a large parameter space derived in previous studies. In addition to known freeze-in pair production of $N$ from the standard model fermion pairs, we find the case that $N$ is dominantly produced from a pair of $Z'$ at the temperature characterized by the $B-L$ breaking scalar mass. Thus, the naive truncation of the $U(1)_{B-L}$ scalar contribution made in the literature is not valid. |
hep-ph/0408211 | M\'arcio Jos\'e Menon | E. G. S. Luna, M. J. Menon and J. Montanha | An analysis on extrema and constrained bounds for the soft Pomeron
intercept | 20 pages, 5 eps-figures, elsart.cls (included), submitted to Nucl.
Phys. A | Nucl.Phys. A745 (2004) 104-120 | 10.1016/j.nuclphysa.2004.09.004 | null | hep-ph | null | We investigate some aspects and consequences of the extrema bounds for the
soft Pomeron intercept, recently determined by means of global fits to $pp$ and
$\bar{p}p$ total cross section data at both accelerator and cosmic-ray energy
regions (scattering data). We also examine the effects of the secondary
Reggeons by introducing fitted trajectories from Chew-Frautschi plots
(spectroscopy data) and determining new constrained bounds for the Pomeron
intercept. In both cases we extend the analysis to $baryon-p$, $meson-p$,
$baryon-n$, $meson-n$, $gamma-p$ and $gamma-gamma$ scattering, presenting tests
on factorization and quark counting rules. We show that in all the cases
investigated, the bounds lead to good descriptions of the bulk of experimental
data on the total cross sections, but with different extrapolations to higher
energies. Our main conclusion is that the experimental information presently
available on the above quantities is not sensitive to an uncertainty of 2% in
the value of the soft Pomeron intercept. At 14 TeV (CERN LHC) the extrema and
constrained bounds allow to infer $\sigma_{tot}$ = 114 $\pm$ 25 mb and 105
$\pm$ 10 mb, respectively.
| [
{
"created": "Wed, 18 Aug 2004 22:24:58 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Luna",
"E. G. S.",
""
],
[
"Menon",
"M. J.",
""
],
[
"Montanha",
"J.",
""
]
] | We investigate some aspects and consequences of the extrema bounds for the soft Pomeron intercept, recently determined by means of global fits to $pp$ and $\bar{p}p$ total cross section data at both accelerator and cosmic-ray energy regions (scattering data). We also examine the effects of the secondary Reggeons by introducing fitted trajectories from Chew-Frautschi plots (spectroscopy data) and determining new constrained bounds for the Pomeron intercept. In both cases we extend the analysis to $baryon-p$, $meson-p$, $baryon-n$, $meson-n$, $gamma-p$ and $gamma-gamma$ scattering, presenting tests on factorization and quark counting rules. We show that in all the cases investigated, the bounds lead to good descriptions of the bulk of experimental data on the total cross sections, but with different extrapolations to higher energies. Our main conclusion is that the experimental information presently available on the above quantities is not sensitive to an uncertainty of 2% in the value of the soft Pomeron intercept. At 14 TeV (CERN LHC) the extrema and constrained bounds allow to infer $\sigma_{tot}$ = 114 $\pm$ 25 mb and 105 $\pm$ 10 mb, respectively. |
1603.01620 | Emanuele Re | William Astill, Wojciech Bizon, Emanuele Re, Giulia Zanderighi | NNLOPS accurate associated HW production | Minor changes, plots updated, matches the version published in JHEP | null | 10.1007/JHEP06(2016)154 | CERN-PH-TH/2016-049, LAPTH-010/16, OUTP-16-04P | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a next-to-next-to-leading order accurate description of associated
HW production consistently matched to a parton shower. The method is based on
reweighting events obtained with the HW plus one jet NLO accurate calculation
implemented in POWHEG, extended with the MiNLO procedure, to reproduce NNLO
accurate Born distributions. Since the Born kinematics is more complex than the
cases treated before, we use a parametrization of the Collins-Soper angles to
reduce the number of variables required for the reweighting. We present
phenomenological results at 13 TeV, with cuts suggested by the Higgs Cross
Section Working Group.
| [
{
"created": "Fri, 4 Mar 2016 21:00:06 GMT",
"version": "v1"
},
{
"created": "Thu, 7 Jul 2016 14:07:00 GMT",
"version": "v2"
}
] | 2016-07-20 | [
[
"Astill",
"William",
""
],
[
"Bizon",
"Wojciech",
""
],
[
"Re",
"Emanuele",
""
],
[
"Zanderighi",
"Giulia",
""
]
] | We present a next-to-next-to-leading order accurate description of associated HW production consistently matched to a parton shower. The method is based on reweighting events obtained with the HW plus one jet NLO accurate calculation implemented in POWHEG, extended with the MiNLO procedure, to reproduce NNLO accurate Born distributions. Since the Born kinematics is more complex than the cases treated before, we use a parametrization of the Collins-Soper angles to reduce the number of variables required for the reweighting. We present phenomenological results at 13 TeV, with cuts suggested by the Higgs Cross Section Working Group. |
1407.6866 | Arghya Choudhury | Biplob Bhattacherjee and Arghya Choudhury | The role of MSSM heavy Higgs production in the self coupling measurement
of the 125 GeV Higgs boson at the LHC | 20 pages, 3 figures; References added; Text updated with more
detailed results and new figures, To appear in Phys. Rev. D | Phys. Rev. D 91, 073015 (2015) | 10.1103/PhysRevD.91.073015 | IPMU14-0237 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Measurement of the self coupling of 125 GeV Higgs boson is one of the most
crucial tasks for high luminosity run of the LHC and it can only be measured in
the di-Higgs final state. In the minimal supersymmetric standard model, heavy
CP even Higgs ($H$) can decay into lighter 125 GeV Higgs boson ($h$) and
therefore influence the di-Higgs production. We investigate the role of single
$H$ production in the measurement of self coupling of $h$. We find that $H
\rightarrow hh$ decay can nontrivially affect the $h$ self coupling measurement
in low tan$\beta$ regime when the mass of the heavy Higgs boson lies between
250 - 600 GeV and depending on the parameter space it may be seen as an
enhancement of the self coupling of 125 GeV Higgs boson.
| [
{
"created": "Fri, 25 Jul 2014 12:31:33 GMT",
"version": "v1"
},
{
"created": "Thu, 19 Mar 2015 17:37:52 GMT",
"version": "v2"
}
] | 2015-04-29 | [
[
"Bhattacherjee",
"Biplob",
""
],
[
"Choudhury",
"Arghya",
""
]
] | Measurement of the self coupling of 125 GeV Higgs boson is one of the most crucial tasks for high luminosity run of the LHC and it can only be measured in the di-Higgs final state. In the minimal supersymmetric standard model, heavy CP even Higgs ($H$) can decay into lighter 125 GeV Higgs boson ($h$) and therefore influence the di-Higgs production. We investigate the role of single $H$ production in the measurement of self coupling of $h$. We find that $H \rightarrow hh$ decay can nontrivially affect the $h$ self coupling measurement in low tan$\beta$ regime when the mass of the heavy Higgs boson lies between 250 - 600 GeV and depending on the parameter space it may be seen as an enhancement of the self coupling of 125 GeV Higgs boson. |
1010.5729 | Alexander Merle | Pasquale Di Bari, Stephen F. King, Christoph Luhn, Alexander Merle,
Angnis Schmidt-May | Radiative Inflation and Dark Energy | 15 pages, 4 figures; v2: references added, appendix added, Section 5
slightly modified; content matches published version | Phys. Rev. D 84, 083524 (2011) | 10.1103/PhysRevD.84.083524 | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose a model based on radiative symmetry breaking that combines
inflation with Dark Energy and is consistent with the WMAP 7-year regions. The
radiative inflationary potential leads to the prediction of a spectral index
0.955 \lesssim n_S \lesssim 0.967 and a tensor to scalar ratio 0.142 \lesssim r
\lesssim 0.186, both consistent with current data but testable by the Planck
experiment. The radiative symmetry breaking close to the Planck scale gives
rise to a pseudo Nambu-Goldstone boson with a gravitationally suppressed mass
which can naturally play the role of a quintessence field responsible for Dark
Energy. Finally, we present a possible extra dimensional scenario in which our
model could be realised.
| [
{
"created": "Wed, 27 Oct 2010 16:23:09 GMT",
"version": "v1"
},
{
"created": "Wed, 26 Oct 2011 11:40:12 GMT",
"version": "v2"
}
] | 2011-10-27 | [
[
"Di Bari",
"Pasquale",
""
],
[
"King",
"Stephen F.",
""
],
[
"Luhn",
"Christoph",
""
],
[
"Merle",
"Alexander",
""
],
[
"Schmidt-May",
"Angnis",
""
]
] | We propose a model based on radiative symmetry breaking that combines inflation with Dark Energy and is consistent with the WMAP 7-year regions. The radiative inflationary potential leads to the prediction of a spectral index 0.955 \lesssim n_S \lesssim 0.967 and a tensor to scalar ratio 0.142 \lesssim r \lesssim 0.186, both consistent with current data but testable by the Planck experiment. The radiative symmetry breaking close to the Planck scale gives rise to a pseudo Nambu-Goldstone boson with a gravitationally suppressed mass which can naturally play the role of a quintessence field responsible for Dark Energy. Finally, we present a possible extra dimensional scenario in which our model could be realised. |
hep-ph/9904394 | Francesc Ferrer | F. Ferrer and J.A. Grifols | Casimir-Polder forces in the presence of the cosmic photon heat bath | 8 pages, 2 figures | Phys.Lett. B460 (1999) 371-375; Erratum-ibid. B511 (2001) 319-320 | 10.1016/S0370-2693(99)00812-6 | UAB-FT-465 | hep-ph | null | We study the effect of a photon background at finite temperature $T$ on the
Van der Waals interactions among neutral bodies. It turns out that the
long-range Casimir-Polder force is unaffected for distances much less than
$T^{-1}$ and strongly enhanced for distances much above $T^{-1}$.
| [
{
"created": "Mon, 19 Apr 1999 16:15:00 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Ferrer",
"F.",
""
],
[
"Grifols",
"J. A.",
""
]
] | We study the effect of a photon background at finite temperature $T$ on the Van der Waals interactions among neutral bodies. It turns out that the long-range Casimir-Polder force is unaffected for distances much less than $T^{-1}$ and strongly enhanced for distances much above $T^{-1}$. |
hep-ph/0307382 | Markus Diehl | M. Diehl | Generalized Parton Distributions | 226 pages, 47 figures. v2: Small corrections and a note added | Phys.Rept.388:41-277,2003 | 10.1016/j.physrep.2003.08.002 | DESY-THESIS-2003-018 | hep-ph | null | We give an overview of the theory for generalized parton distributions.
Topics covered are their general properties and physical interpretation, the
possibility to explore the three-dimensional structure of hadrons at parton
level, their potential to unravel the spin structure of the nucleon, their role
in small-x physics, and efforts to model their dynamics. We review our
understanding of the reactions where generalized parton distributions occur, to
leading power accuracy and beyond, and present strategies for phenomenological
analysis. We emphasize the close connection between generalized parton
distributions and generalized distribution amplitudes, whose properties and
physics we also present. We finally discuss the use of these quantities for
describing soft contributions to exclusive processes at large energy and
momentum transfer.
| [
{
"created": "Thu, 31 Jul 2003 00:45:45 GMT",
"version": "v1"
},
{
"created": "Fri, 17 Oct 2003 09:50:28 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Diehl",
"M.",
""
]
] | We give an overview of the theory for generalized parton distributions. Topics covered are their general properties and physical interpretation, the possibility to explore the three-dimensional structure of hadrons at parton level, their potential to unravel the spin structure of the nucleon, their role in small-x physics, and efforts to model their dynamics. We review our understanding of the reactions where generalized parton distributions occur, to leading power accuracy and beyond, and present strategies for phenomenological analysis. We emphasize the close connection between generalized parton distributions and generalized distribution amplitudes, whose properties and physics we also present. We finally discuss the use of these quantities for describing soft contributions to exclusive processes at large energy and momentum transfer. |
hep-ph/0104082 | Boris Ermolaev | B.I. Ermolaev, M. Greco and S.I. Troyan | Treatment of the QCD coupling in high energy processes | RevTeX 6 pages, 6 figures epsf.sty | Phys.Lett.B522:57-66,2001 | 10.1016/S0370-2693(01)01252-7 | null | hep-ph | null | The treatment of the running QCD coupling in evolution equations is
discussed. It is shown that the use of the virtuality of ladder (vertical)
partons as the scale for QCD coupling in every rung of ladder graphs is an
approximation that holds for DIS at large x only. On the contrary, in the small
x region the coupling depends on the virtuality of s -channel (horizontal)
gluons. This observation leads to different results for the Regge-like
processes and DIS structure functions at small x.
| [
{
"created": "Mon, 9 Apr 2001 08:39:37 GMT",
"version": "v1"
},
{
"created": "Thu, 27 Sep 2001 10:55:11 GMT",
"version": "v2"
}
] | 2010-03-25 | [
[
"Ermolaev",
"B. I.",
""
],
[
"Greco",
"M.",
""
],
[
"Troyan",
"S. I.",
""
]
] | The treatment of the running QCD coupling in evolution equations is discussed. It is shown that the use of the virtuality of ladder (vertical) partons as the scale for QCD coupling in every rung of ladder graphs is an approximation that holds for DIS at large x only. On the contrary, in the small x region the coupling depends on the virtuality of s -channel (horizontal) gluons. This observation leads to different results for the Regge-like processes and DIS structure functions at small x. |
1007.2102 | Yambazi Banda Dr | Yambazi Banda, Tomas Lastovicka and Andrei Nomerotski | Higgs boson hadronic branching ratios at the ILC | 9 Pages, 5 figures and 5 tables | Phys.Rev.D82:033013,2010 | 10.1103/PhysRevD.82.033013 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a study of the Higgs boson decay branching ratios to $b\bar{b}$,
$c\bar{c}$ and gluons, one of the cornerstones of the physics program at the
International Linear Collider (ILC). A standard model Higgs boson of 120\,GeV
mass, produced in the Higgs-strahlung process at $\sqrt{s} = 250$\,GeV was
investigated using the full detector simulation and reconstruction procedures.
The analysis was performed in the framework of the Silicon Detector (SiD)
concept with full account of inclusive standard model backgrounds. The selected
decay modes contained two heavy flavour jets in the final state and required
excellent flavour tagging through precise reconstruction of interaction and
decay vertices in the detector. A new signal discrimination technique using
correlations of neural network outputs was used to determine the branching
ratios and estimate their uncertainties, 4.8\%, 8.4\% and 12.2\% for
$b\bar{b}$, $c\bar{c}$ and gluons respectively.
| [
{
"created": "Tue, 13 Jul 2010 13:17:11 GMT",
"version": "v1"
}
] | 2014-11-21 | [
[
"Banda",
"Yambazi",
""
],
[
"Lastovicka",
"Tomas",
""
],
[
"Nomerotski",
"Andrei",
""
]
] | We present a study of the Higgs boson decay branching ratios to $b\bar{b}$, $c\bar{c}$ and gluons, one of the cornerstones of the physics program at the International Linear Collider (ILC). A standard model Higgs boson of 120\,GeV mass, produced in the Higgs-strahlung process at $\sqrt{s} = 250$\,GeV was investigated using the full detector simulation and reconstruction procedures. The analysis was performed in the framework of the Silicon Detector (SiD) concept with full account of inclusive standard model backgrounds. The selected decay modes contained two heavy flavour jets in the final state and required excellent flavour tagging through precise reconstruction of interaction and decay vertices in the detector. A new signal discrimination technique using correlations of neural network outputs was used to determine the branching ratios and estimate their uncertainties, 4.8\%, 8.4\% and 12.2\% for $b\bar{b}$, $c\bar{c}$ and gluons respectively. |
0912.2571 | J. P. Ma | F. Feng and J.P. Ma | Resummation of Large Logarithms in the Electromagnetic Form factor of
pion | 21 pages, 6 figures, title corrected | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the collinear factorization of the form factor for the transition
$\gamma^* \pi^0 \to \pi$ the hard part contains double log terms. These terms
will spoil the perturbative expansion of the hard part. A simple exponentiation
for resummation leads to divergent results. We study the resummation of these
double log's. We make an analysis to show the origin of the double log's. With
the understanding of the origin one can introduce soft factors and Nonstandard
Light-Cone Wave Functions(NLCWF) to derive a factorized form for the form
factor, where the hard part does not contain the double log's. There is a
perturbative relation between NLCWF and the standard Light-Cone Wave
Function(LCWF). Beside the renormalization scale $\mu$ the introduced NLCWF's
and soft factors have extra scales to characterize the double log's. Using the
evolutions of the extra scales and the relation we can do the resummation of
the double log's perturbatively in sense that LCWF's are the only
nonpertubative objects in the resumed formula. Our results with some models of
LCWF show that there is a significant difference between numerical predictions
with or without the resummation.
| [
{
"created": "Mon, 14 Dec 2009 03:56:52 GMT",
"version": "v1"
},
{
"created": "Tue, 15 Dec 2009 05:23:26 GMT",
"version": "v2"
}
] | 2009-12-15 | [
[
"Feng",
"F.",
""
],
[
"Ma",
"J. P.",
""
]
] | In the collinear factorization of the form factor for the transition $\gamma^* \pi^0 \to \pi$ the hard part contains double log terms. These terms will spoil the perturbative expansion of the hard part. A simple exponentiation for resummation leads to divergent results. We study the resummation of these double log's. We make an analysis to show the origin of the double log's. With the understanding of the origin one can introduce soft factors and Nonstandard Light-Cone Wave Functions(NLCWF) to derive a factorized form for the form factor, where the hard part does not contain the double log's. There is a perturbative relation between NLCWF and the standard Light-Cone Wave Function(LCWF). Beside the renormalization scale $\mu$ the introduced NLCWF's and soft factors have extra scales to characterize the double log's. Using the evolutions of the extra scales and the relation we can do the resummation of the double log's perturbatively in sense that LCWF's are the only nonpertubative objects in the resumed formula. Our results with some models of LCWF show that there is a significant difference between numerical predictions with or without the resummation. |
hep-ph/9911541 | Shinya Kanemura | Shinya Kanemura (ITP, Uni. Karlsruhe) | Possible enhancement of the $e^+ e^- \to H^\pm W^\mp$ cross section in
the two-Higgs-doublet model | The published version. Several improvements have been done. 1 latex
plus 9 ps files for figures. (text 20 pages). To appear in European Physical
Journal C | Eur.Phys.J.C17:473-486,2000 | 10.1007/s100520000480 | KA-TP-22-1999 | hep-ph | null | The production process of the charged Higgs-boson associated with a $W$ boson
at electron-positron colliders is discussed in the two-Higgs-Doublet Model
(2HDM) and in the Minimal Supersymmetric Standard Model (MSSM). The process is
induced at one-loop level in these models. We examine how much the cross
section can be enhanced by quark- and Higgs-loop effects. In the non-SUSY 2HDM,
in addition to large top-bottom ($t$-$b$) loop effects for small $\tan \beta$
($\ll \sqrt{m_t/m_b}$), the Higgs-loop diagrams can contribute to the cross
section to some extent for moderate $\tan \beta$ values. For larger $\tan
\beta$ ($\gg \sqrt{m_t/m_b}$), such enhancement by the Higgs non-decoupling
effects is bounded by the requirement for validity of perturbation theory. In
the MSSM with heavy super-partner particles, only the $t$-$b$ loops enhance the
cross section while Higgs-loop effects are very small.
| [
{
"created": "Tue, 30 Nov 1999 22:46:24 GMT",
"version": "v1"
},
{
"created": "Sun, 9 Jul 2000 11:43:35 GMT",
"version": "v2"
}
] | 2011-09-13 | [
[
"Kanemura",
"Shinya",
"",
"ITP, Uni. Karlsruhe"
]
] | The production process of the charged Higgs-boson associated with a $W$ boson at electron-positron colliders is discussed in the two-Higgs-Doublet Model (2HDM) and in the Minimal Supersymmetric Standard Model (MSSM). The process is induced at one-loop level in these models. We examine how much the cross section can be enhanced by quark- and Higgs-loop effects. In the non-SUSY 2HDM, in addition to large top-bottom ($t$-$b$) loop effects for small $\tan \beta$ ($\ll \sqrt{m_t/m_b}$), the Higgs-loop diagrams can contribute to the cross section to some extent for moderate $\tan \beta$ values. For larger $\tan \beta$ ($\gg \sqrt{m_t/m_b}$), such enhancement by the Higgs non-decoupling effects is bounded by the requirement for validity of perturbation theory. In the MSSM with heavy super-partner particles, only the $t$-$b$ loops enhance the cross section while Higgs-loop effects are very small. |
hep-ph/9805327 | Wim Beenakker | W. Beenakker, F.A. Berends, A.P. Chapovsky (Leiden) | Final-state radiation and line-shape distortion in resonance pair
production | 9 pages, LaTeX2e, 1 figure | Phys.Lett. B435 (1998) 233-239 | 10.1016/S0370-2693(98)00760-6 | null | hep-ph | null | In this letter it is shown how final-state QED corrections to the production
of a pair of resonances can distort the line shape of such a resonance in a
sizeable way. This effect depends on the definition of the line shape and can
reach up to 30%, depending on the final state. The mechanism is first displayed
for a particular case of ZZ production, for which an exact and approximate
treatment can be given. The approximate method is then applied to W-pair
production. In addition some simple rules of thumb are given for accurately
estimating the characteristic distortion effects, like the mass shift and peak
reduction.
| [
{
"created": "Thu, 14 May 1998 14:45:18 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Beenakker",
"W.",
"",
"Leiden"
],
[
"Berends",
"F. A.",
"",
"Leiden"
],
[
"Chapovsky",
"A. P.",
"",
"Leiden"
]
] | In this letter it is shown how final-state QED corrections to the production of a pair of resonances can distort the line shape of such a resonance in a sizeable way. This effect depends on the definition of the line shape and can reach up to 30%, depending on the final state. The mechanism is first displayed for a particular case of ZZ production, for which an exact and approximate treatment can be given. The approximate method is then applied to W-pair production. In addition some simple rules of thumb are given for accurately estimating the characteristic distortion effects, like the mass shift and peak reduction. |
2103.01939 | Wilke van der Schee | Jasmine Brewer, Aleksas Mazeliauskas and Wilke van der Schee | Opportunities of OO and $p$O collisions at the LHC | Workshop summary (see http://cern.ch/OppOatLHC ), 6 pages, 9 figures | null | null | CERN-TH-2021-028 | hep-ph astro-ph.HE hep-ex nucl-ex nucl-th | http://creativecommons.org/licenses/by/4.0/ | This is the summary document of the virtual workshop "Opportunities of OO and
$p$O collisions at the LHC", which took place Feb 4-10, 2021. We briefly review
the presented perspectives on the physics opportunities of oxygen--oxygen and
proton--oxygen collisions. The full workshop program and the recordings are
available at cern.ch/OppOatLHC.
| [
{
"created": "Tue, 2 Mar 2021 18:55:55 GMT",
"version": "v1"
}
] | 2021-03-03 | [
[
"Brewer",
"Jasmine",
""
],
[
"Mazeliauskas",
"Aleksas",
""
],
[
"van der Schee",
"Wilke",
""
]
] | This is the summary document of the virtual workshop "Opportunities of OO and $p$O collisions at the LHC", which took place Feb 4-10, 2021. We briefly review the presented perspectives on the physics opportunities of oxygen--oxygen and proton--oxygen collisions. The full workshop program and the recordings are available at cern.ch/OppOatLHC. |
hep-ph/9312228 | Zhora Jikia | G. Jikia and A. Tkabladze | Photon-Photon Scattering at the Photon Linear Collider | Standard LaTeX. 8 pages+5 figures (available by regular mail). IHEP
93-89 | Phys.Lett. B323 (1994) 453-458 | 10.1016/0370-2693(94)91246-7 | null | hep-ph | null | Photon-photon scattering at the Photon Linear Collider is considered.
Explicit formulas for helicity amplitudes due to $W$ boson loops are presented.
It is shown that photon-photon scattering should be easily observable at PLC
and separation of the $W$ loop contribution (which dominates at high energies)
will be possible at $e^+e^-$ c.m. energy of 500~GeV or higher.
| [
{
"created": "Mon, 6 Dec 1993 10:35:44 GMT",
"version": "v1"
},
{
"created": "Mon, 20 Dec 1993 21:19:45 GMT",
"version": "v2"
}
] | 2009-10-22 | [
[
"Jikia",
"G.",
""
],
[
"Tkabladze",
"A.",
""
]
] | Photon-photon scattering at the Photon Linear Collider is considered. Explicit formulas for helicity amplitudes due to $W$ boson loops are presented. It is shown that photon-photon scattering should be easily observable at PLC and separation of the $W$ loop contribution (which dominates at high energies) will be possible at $e^+e^-$ c.m. energy of 500~GeV or higher. |
1108.0070 | Fuminobu Takahashi | Kazunori Nakayama and Fuminobu Takahashi | Low-scale Supersymmetry from Inflation | 23pages, 3 figures. v2: references added | JCAP10(2011)033 | 10.1088/1475-7516/2011/10/033 | TU-887; IPMU11-0127 | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate an inflation model with the inflaton being identified with a
Higgs boson responsible for the breaking of U(1)B-L symmetry. We show that
supersymmetry must remain a good symmetry at scales one order of magnitude
below the inflation scale, in order for the inflation model to solve the
horizon and flatness problems, as well as to account for the observed density
perturbation. The upper bound on the soft supersymmetry breaking mass lies
between 1TeV and 10^3TeV. Interestingly, our finding opens up a possibility
that universes with the low-scale supersymmetry are realized by the
inflationary selection. Our inflation model has rich implications; non-thermal
leptogenesis naturally works, and the gravitino and moduli problems as well as
the moduli destabilization problem can be solved or ameliorated; the
standard-model higgs boson receives a sizable radiative correction if the
supersymmertry breaking takes a value on the high side ~10^3TeV.
| [
{
"created": "Sat, 30 Jul 2011 13:59:03 GMT",
"version": "v1"
},
{
"created": "Fri, 5 Aug 2011 12:11:23 GMT",
"version": "v2"
}
] | 2012-03-13 | [
[
"Nakayama",
"Kazunori",
""
],
[
"Takahashi",
"Fuminobu",
""
]
] | We investigate an inflation model with the inflaton being identified with a Higgs boson responsible for the breaking of U(1)B-L symmetry. We show that supersymmetry must remain a good symmetry at scales one order of magnitude below the inflation scale, in order for the inflation model to solve the horizon and flatness problems, as well as to account for the observed density perturbation. The upper bound on the soft supersymmetry breaking mass lies between 1TeV and 10^3TeV. Interestingly, our finding opens up a possibility that universes with the low-scale supersymmetry are realized by the inflationary selection. Our inflation model has rich implications; non-thermal leptogenesis naturally works, and the gravitino and moduli problems as well as the moduli destabilization problem can be solved or ameliorated; the standard-model higgs boson receives a sizable radiative correction if the supersymmertry breaking takes a value on the high side ~10^3TeV. |
2202.13647 | Vitaly Magerya | Vitaly Magerya | Loop integral evaluation and asymptotic expansion with pySecDec | Contribution to the proceedings of ACAT 2021 | null | null | KA-TP-02-2022 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The evaluation of higher-loop Feynman integrals is at the core of the quest
to reduce the uncertainty of theoretical predictions and match experimental
data from the LHC and future colliders. pySecDec is a program to evaluate such
integrals numerically based on the sector decomposition approach; its new
release version 1.5 introduces features significantly improving its
performance: automatic adaptive evaluation of weighted sums of integrals (e.g.
amplitudes) and asymptotic expansion in kinematic ratios. Here we briefly
review both, illustrating the expected performance benefits.
| [
{
"created": "Mon, 28 Feb 2022 09:43:29 GMT",
"version": "v1"
}
] | 2022-03-01 | [
[
"Magerya",
"Vitaly",
""
]
] | The evaluation of higher-loop Feynman integrals is at the core of the quest to reduce the uncertainty of theoretical predictions and match experimental data from the LHC and future colliders. pySecDec is a program to evaluate such integrals numerically based on the sector decomposition approach; its new release version 1.5 introduces features significantly improving its performance: automatic adaptive evaluation of weighted sums of integrals (e.g. amplitudes) and asymptotic expansion in kinematic ratios. Here we briefly review both, illustrating the expected performance benefits. |
hep-ph/0307054 | Tom Browder | Thomas E. Browder, Sandip Pakvasa, Alexey A. Petrov | Comment on the new $D_s^{(*)+} \pi^0$ resonances | 4 pages, 2 figures. Updated references. To appear in Phys. Lett. B | Phys.Lett.B578:365-368,2004 | 10.1016/j.physletb.2003.10.067 | WSU-HEP-0306 | hep-ph hep-ex | null | We propose an explanation of the new resonances observed in $D_s^{(*)+}
\pi^0$ decays. We suggest that the data can be explained by the mixing of
conventional p-wave excited $D_s^+$ mesons with 4-quark states. The narrow
states observed in $D_s^+ \pi^0$ and $D_s^{*+}\pi^0$ are primarily p-wave
$D_{sJ}^{*}$ states, while the predominantly 4-quark states are shifted above
$D^{(*)} K$ threshold and should be broad. Ranges for the mixing parameter and
mass of the 4-quark state in this scenario are given. Other experimental
consequences are discussed.
| [
{
"created": "Fri, 4 Jul 2003 03:01:12 GMT",
"version": "v1"
},
{
"created": "Mon, 28 Jul 2003 01:44:51 GMT",
"version": "v2"
},
{
"created": "Tue, 2 Sep 2003 02:38:52 GMT",
"version": "v3"
},
{
"created": "Tue, 11 Nov 2003 21:19:35 GMT",
"version": "v4"
}
] | 2008-11-26 | [
[
"Browder",
"Thomas E.",
""
],
[
"Pakvasa",
"Sandip",
""
],
[
"Petrov",
"Alexey A.",
""
]
] | We propose an explanation of the new resonances observed in $D_s^{(*)+} \pi^0$ decays. We suggest that the data can be explained by the mixing of conventional p-wave excited $D_s^+$ mesons with 4-quark states. The narrow states observed in $D_s^+ \pi^0$ and $D_s^{*+}\pi^0$ are primarily p-wave $D_{sJ}^{*}$ states, while the predominantly 4-quark states are shifted above $D^{(*)} K$ threshold and should be broad. Ranges for the mixing parameter and mass of the 4-quark state in this scenario are given. Other experimental consequences are discussed. |
2306.16550 | Johannes Bl\"umlein | J. Ablinger, A. Behring, J.Bl\"umlein, A. De Freitas, A. Goedicke, A.
von Manteuffel, C. Schneider, K. Sch\"onwald | Recent 3-Loop Heavy Flavor Corrections to Deep-Inelastic Scattering | Proc RADCOR 2023, 7 pages, 1 figure | null | null | DESY-23-089, DO-TH 23/09, CERN-TH-2023-122, ZU-TH 29/23, RISC Report
Series 23-09, MSUHEP-23-018 | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | We report on recent progress in calculating the three loop QCD corrections of
the heavy flavor contributions in deep--inelastic scattering and the massive
operator matrix elements of the variable flavor number scheme. Notably we deal
with the operator matrix elements $A_{gg,Q}^{(3)}$ and $A_{Qg}^{(3)}$ and
technical steps to their calculation. In particular, a new method to obtain the
inverse Mellin transform without computing the corresponding $N$--space
expressions is discussed.
| [
{
"created": "Wed, 28 Jun 2023 20:40:52 GMT",
"version": "v1"
}
] | 2023-06-30 | [
[
"Ablinger",
"J.",
""
],
[
"Behring",
"A.",
""
],
[
"Blümlein",
"J.",
""
],
[
"De Freitas",
"A.",
""
],
[
"Goedicke",
"A.",
""
],
[
"von Manteuffel",
"A.",
""
],
[
"Schneider",
"C.",
""
],
[
"Schönwald",
"K.",
""
]
] | We report on recent progress in calculating the three loop QCD corrections of the heavy flavor contributions in deep--inelastic scattering and the massive operator matrix elements of the variable flavor number scheme. Notably we deal with the operator matrix elements $A_{gg,Q}^{(3)}$ and $A_{Qg}^{(3)}$ and technical steps to their calculation. In particular, a new method to obtain the inverse Mellin transform without computing the corresponding $N$--space expressions is discussed. |
2204.06814 | Zhuo-Ran Huang | Zhuo-Ran Huang, Emi Kou, Cai-Dian L\"u and Ru-Ying Tang | Unbinned Angular Analysis of $B\to D^*(D\pi)\ell \nu_\ell$ and $C_{V_R}$ | 5 pages and 1 figure; Contribution to the proceedings of the 30th
International Symposium on Lepton Photon Interactions at High Energies,
hosted by the University of Manchester, 10-14 January 2022 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A sensitivity study of the unbinned angular analysis of the $B\to
D^*(D\pi)\ell \nu_\ell$ decay is presented. In the analysis, it is shown that
the Wilson coefficient of the right-handed vector current, $C_{V_R}$, can be
measured to precision of 2-4$\%$ using either the full set of normalised
angular observables or the forward-backward asymmetry $A_{FB}$ of the charged
lepton in 10 $w$ bins. Such angular measurements are independent of the
$V_{cb}$ puzzle.
| [
{
"created": "Thu, 14 Apr 2022 08:21:56 GMT",
"version": "v1"
}
] | 2022-04-15 | [
[
"Huang",
"Zhuo-Ran",
""
],
[
"Kou",
"Emi",
""
],
[
"Lü",
"Cai-Dian",
""
],
[
"Tang",
"Ru-Ying",
""
]
] | A sensitivity study of the unbinned angular analysis of the $B\to D^*(D\pi)\ell \nu_\ell$ decay is presented. In the analysis, it is shown that the Wilson coefficient of the right-handed vector current, $C_{V_R}$, can be measured to precision of 2-4$\%$ using either the full set of normalised angular observables or the forward-backward asymmetry $A_{FB}$ of the charged lepton in 10 $w$ bins. Such angular measurements are independent of the $V_{cb}$ puzzle. |
hep-ph/9609529 | Sandip Trivedi | E. Poppitz and S.P. Trivedi | New Models of Gauge and Gravity Mediated Supersymmetry Breaking | Revised discussion of communication of supersymmetry breaking, 24
pages, LaTeX | Phys.Rev.D55:5508-5519,1997 | 10.1103/PhysRevD.55.5508 | EFI-96-35; Fermilab-Pub-96/338-T | hep-ph hep-th | null | We show that supersymmetry breaking in a class of theories with SU(N) x
SU(N-2) gauge symmetry can be studied in a calculable sigma model. We use the
sigma model to show that the supersymmetry breaking vacuum in these theories
leaves a large subgroup of flavor symmetries intact, and to calculate the
masses of the low-lying states. By embedding the Standard Model gauge groups in
the unbroken flavor symmetry group we construct a class of models in which
supersymmetry breaking is communicated by both gravitational and gauge
interactions. One distinguishing feature of these models is that the messenger
fields, responsible for the gauge mediated communication of supersymmetry
breaking, are an integral part of the supersymmetry breaking sector. We also
show how, by lowering the scale that suppresses the nonrenormalizable
operators, a class of purely gauge mediated models with a combined
supersymmetry breaking-cum-messenger sector can be built. We briefly discuss
the phenomenological features of the models we construct.
| [
{
"created": "Mon, 30 Sep 1996 21:37:25 GMT",
"version": "v1"
},
{
"created": "Mon, 23 Dec 1996 22:43:18 GMT",
"version": "v2"
}
] | 2011-05-05 | [
[
"Poppitz",
"E.",
""
],
[
"Trivedi",
"S. P.",
""
]
] | We show that supersymmetry breaking in a class of theories with SU(N) x SU(N-2) gauge symmetry can be studied in a calculable sigma model. We use the sigma model to show that the supersymmetry breaking vacuum in these theories leaves a large subgroup of flavor symmetries intact, and to calculate the masses of the low-lying states. By embedding the Standard Model gauge groups in the unbroken flavor symmetry group we construct a class of models in which supersymmetry breaking is communicated by both gravitational and gauge interactions. One distinguishing feature of these models is that the messenger fields, responsible for the gauge mediated communication of supersymmetry breaking, are an integral part of the supersymmetry breaking sector. We also show how, by lowering the scale that suppresses the nonrenormalizable operators, a class of purely gauge mediated models with a combined supersymmetry breaking-cum-messenger sector can be built. We briefly discuss the phenomenological features of the models we construct. |
2111.13821 | Xiang Liu | Ri-Qing Qian, Qi Huang and Xiang Liu | Predicted $\Lambda\bar{\Lambda}$ and $\Xi^-\bar{\Xi}^+$ decay modes of
the charmoniumlike $Y(4230)$ | 8 pages, 9 figures and 2 tables | Phys. Lett. B 833, 137292 (2022) | 10.1016/j.physletb.2022.137292 | null | hep-ph hep-ex | http://creativecommons.org/publicdomain/zero/1.0/ | In this work, we predict the light hadronic decay channels
$Y(4230)\to\Lambda\bar{\Lambda}$ and $\Xi^-\bar{\Xi}^+$ when treating the
$Y(4230)$ as a vector charmonium state. By the hadronic loop mechanism, the
branching ratios of the $Y(4230)\to\Lambda\bar{\Lambda}$ and $\Xi^-\bar{\Xi}^+$
processes are calculated. In addition, we discuss the possibility of carrying
out the search for the signal of the $Y(4230)$ through $\Lambda\bar{\Lambda}$
and $\Xi^-\bar{\Xi}^+$ channels from the $e^+e^-$ annihilation. Assuming
$Y(4230)$ exist in $\Lambda\bar{\Lambda}$ and $\Xi^-\bar{\Xi}^+$ channel, we
also present the time-like electromagnetic form factors (EMFFs) at
$\sqrt{s}=m_{Y(4230)}$.
| [
{
"created": "Sat, 27 Nov 2021 06:12:45 GMT",
"version": "v1"
},
{
"created": "Sat, 14 May 2022 07:53:32 GMT",
"version": "v2"
}
] | 2022-07-20 | [
[
"Qian",
"Ri-Qing",
""
],
[
"Huang",
"Qi",
""
],
[
"Liu",
"Xiang",
""
]
] | In this work, we predict the light hadronic decay channels $Y(4230)\to\Lambda\bar{\Lambda}$ and $\Xi^-\bar{\Xi}^+$ when treating the $Y(4230)$ as a vector charmonium state. By the hadronic loop mechanism, the branching ratios of the $Y(4230)\to\Lambda\bar{\Lambda}$ and $\Xi^-\bar{\Xi}^+$ processes are calculated. In addition, we discuss the possibility of carrying out the search for the signal of the $Y(4230)$ through $\Lambda\bar{\Lambda}$ and $\Xi^-\bar{\Xi}^+$ channels from the $e^+e^-$ annihilation. Assuming $Y(4230)$ exist in $\Lambda\bar{\Lambda}$ and $\Xi^-\bar{\Xi}^+$ channel, we also present the time-like electromagnetic form factors (EMFFs) at $\sqrt{s}=m_{Y(4230)}$. |
hep-ph/0412201 | John M. Cornwall | John M. Cornwall (UCLA) | Baryonic hybrids: Gluons as beads on strings between quarks | 18 pages, revtex4 plus 8 .eps figures in one .tar.gz file | Phys.Rev. D71 (2005) 056002 | 10.1103/PhysRevD.71.056002 | UCLA/04/TEP/51 | hep-ph | null | We analyze the ground state of the heavy-quark hybrid system composed of
three quarks and a gluon. The known string tension K and approximately-known
gluon mass M lead to a precise specification of the long-range non-relativistic
part of the potential binding the gluon to the quarks with no undetermined
phenomenological parameters, in the limit of large interquark separation R. Our
major tool (also used earlier by Simonov) is the use of proper-time methods to
describe gluon propagation within the quark system, which reveals the gluon
Wilson line as a composite of co-located quark and antiquark lines. We show
that (aside from color-Coulomb and similar terms) the gluon potential energy in
the presence of quarks is accurately described via attaching these three
strings to the gluon, which in equilibrium sits at the middle of the Y-shaped
string network joining the three quarks. The gluon undergoes small harmonic
fluctuations that slightly stretch these strings and quasi-confine the gluon to
the neighborhood of the middle. In the non-relativistic limit (large R) we use
the Schrodinger equation, ignoring mixing with l=2 states. Relativistic
corrections (smaller R) are applied with a variational principle for the
relativistic harmonic oscillator. We also consider the role of color-Coulomb
contributions. We find leading non-relativistic large-R terms in the gluon
string energy which behave like the square root of K/(MR). The relativistic
energy goes like the cube root of K/R. We get an acceptable fit to lattice data
with M = 500 MeV. We show that in the quark-antiquark hybrid the gluon is a
bead that can slide without friction on a string joining the quark and
anti-quark. We comment briefly on the significance of our findings to
fluctuations of the minimal surface.
| [
{
"created": "Tue, 14 Dec 2004 21:28:50 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Cornwall",
"John M.",
"",
"UCLA"
]
] | We analyze the ground state of the heavy-quark hybrid system composed of three quarks and a gluon. The known string tension K and approximately-known gluon mass M lead to a precise specification of the long-range non-relativistic part of the potential binding the gluon to the quarks with no undetermined phenomenological parameters, in the limit of large interquark separation R. Our major tool (also used earlier by Simonov) is the use of proper-time methods to describe gluon propagation within the quark system, which reveals the gluon Wilson line as a composite of co-located quark and antiquark lines. We show that (aside from color-Coulomb and similar terms) the gluon potential energy in the presence of quarks is accurately described via attaching these three strings to the gluon, which in equilibrium sits at the middle of the Y-shaped string network joining the three quarks. The gluon undergoes small harmonic fluctuations that slightly stretch these strings and quasi-confine the gluon to the neighborhood of the middle. In the non-relativistic limit (large R) we use the Schrodinger equation, ignoring mixing with l=2 states. Relativistic corrections (smaller R) are applied with a variational principle for the relativistic harmonic oscillator. We also consider the role of color-Coulomb contributions. We find leading non-relativistic large-R terms in the gluon string energy which behave like the square root of K/(MR). The relativistic energy goes like the cube root of K/R. We get an acceptable fit to lattice data with M = 500 MeV. We show that in the quark-antiquark hybrid the gluon is a bead that can slide without friction on a string joining the quark and anti-quark. We comment briefly on the significance of our findings to fluctuations of the minimal surface. |
hep-ph/0507277 | Valery Lyubovitskij | Y. Dong, Amand Faessler, Th. Gutsche, J. Kuckei, V.E. Lyubovitskij, K.
Pumsa-ard, P. Shen | Nucleon polarizabilities in the perturbative chiral quark model | 25 pages, 18 figures, 2 tables | J.Phys.G32:203-220,2006 | 10.1088/0954-3899/32/2/011 | null | hep-ph | null | The nucleon polarizabilities alpha(E) and beta(M) are studied in the context
of the perturbative chiral quark model. We demonstrate that meson cloud effects
are sufficient to explain the electric polarizability of nucleon. Contributions
of excite quark states to the paramagnetic polarizability are dominant and
cancel the diamagnetic polarizability arising from the chiral field. The
obtained results are compared to data and other theoretical predictions.
| [
{
"created": "Mon, 25 Jul 2005 11:34:32 GMT",
"version": "v1"
}
] | 2009-07-09 | [
[
"Dong",
"Y.",
""
],
[
"Faessler",
"Amand",
""
],
[
"Gutsche",
"Th.",
""
],
[
"Kuckei",
"J.",
""
],
[
"Lyubovitskij",
"V. E.",
""
],
[
"Pumsa-ard",
"K.",
""
],
[
"Shen",
"P.",
""
]
] | The nucleon polarizabilities alpha(E) and beta(M) are studied in the context of the perturbative chiral quark model. We demonstrate that meson cloud effects are sufficient to explain the electric polarizability of nucleon. Contributions of excite quark states to the paramagnetic polarizability are dominant and cancel the diamagnetic polarizability arising from the chiral field. The obtained results are compared to data and other theoretical predictions. |
hep-ph/0209358 | Fuminobu Takahashi | S. Kasuya, M. Kawasaki and Fuminobu Takahashi | I-balls | 10 pages,6 figures:revised version | Phys.Lett. B559 (2003) 99-106 | 10.1016/S0370-2693(03)00344-7 | null | hep-ph astro-ph hep-th | null | We find that there exists a soliton-like solution ``I-ball'' in theories of a
real scalar field if the scalar potential satisfies appropriate conditions.
Although the I-ball does not have any topological or global U(1) charges, its
stability is ensured by the adiabatic invariance for the oscillating field.
| [
{
"created": "Mon, 30 Sep 2002 08:21:43 GMT",
"version": "v1"
},
{
"created": "Fri, 27 Dec 2002 05:01:30 GMT",
"version": "v2"
},
{
"created": "Mon, 3 Mar 2003 06:49:11 GMT",
"version": "v3"
}
] | 2009-11-07 | [
[
"Kasuya",
"S.",
""
],
[
"Kawasaki",
"M.",
""
],
[
"Takahashi",
"Fuminobu",
""
]
] | We find that there exists a soliton-like solution ``I-ball'' in theories of a real scalar field if the scalar potential satisfies appropriate conditions. Although the I-ball does not have any topological or global U(1) charges, its stability is ensured by the adiabatic invariance for the oscillating field. |
1205.1208 | Philippe Mertens | Philippe Mertens | $K^+ \ra \pi^+ \pi^0 \gamma$ in the Standard Model and Beyond | Proceedings contribution to the 47th Rencontres de Moriond
Electroweak session 2012 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this note we show how improved theoretical analysis combined with recent
experimental data coming from NA48/2 concerning $K^+ \to \pi^+ \pi^0 \gamma$
decay shed light on the dynamics of the $s \rightarrow d \gamma$ transition.
Consequences on NP analysis are also presented.
| [
{
"created": "Sun, 6 May 2012 11:38:54 GMT",
"version": "v1"
}
] | 2012-05-08 | [
[
"Mertens",
"Philippe",
""
]
] | In this note we show how improved theoretical analysis combined with recent experimental data coming from NA48/2 concerning $K^+ \to \pi^+ \pi^0 \gamma$ decay shed light on the dynamics of the $s \rightarrow d \gamma$ transition. Consequences on NP analysis are also presented. |
hep-ph/0109080 | Konstantinos Anagnostopoulos | K.N. Anagnostopoulos (U.Crete), M. Axenides, E. G. Floratos
(N.C.R.P.S. Demokritos) and N. Tetradis (U.Crete,U.Athens) | Large Gauged Q Balls | 13 Pages, Latex 2.09, 5 figures, accepted for publication in
Phys.Rev.D | Phys.Rev. D64 (2001) 125006 | 10.1103/PhysRevD.64.125006 | null | hep-ph hep-th | null | We study Q-balls associated with local U(1) symmetries. Such Q-balls are
expected to become unstable for large values of their charge because of the
repulsion mediated by the gauge force. We consider the possibility that the
repulsion is eliminated through the presence in the interior of the Q-ball of
fermions with charge opposite to that of the scalar condensate. Another
possibility is that two scalar condensates of opposite charge form in the
interior. We demonstrate that both these scenaria can lead to the existence of
classically stable, large, gauged Q-balls. We present numerical solutions, as
well as an analytical treatment of the ``thin-wall'' limit.
| [
{
"created": "Mon, 10 Sep 2001 12:34:12 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Anagnostopoulos",
"K. N.",
"",
"U.Crete"
],
[
"Axenides",
"M.",
"",
"N.C.R.P.S. Demokritos"
],
[
"Floratos",
"E. G.",
"",
"N.C.R.P.S. Demokritos"
],
[
"Tetradis",
"N.",
"",
"U.Crete,U.Athens"
]
] | We study Q-balls associated with local U(1) symmetries. Such Q-balls are expected to become unstable for large values of their charge because of the repulsion mediated by the gauge force. We consider the possibility that the repulsion is eliminated through the presence in the interior of the Q-ball of fermions with charge opposite to that of the scalar condensate. Another possibility is that two scalar condensates of opposite charge form in the interior. We demonstrate that both these scenaria can lead to the existence of classically stable, large, gauged Q-balls. We present numerical solutions, as well as an analytical treatment of the ``thin-wall'' limit. |
1707.00060 | Elena Bratkovskaya | Andrej Ilner, Justin Blair, Daniel Cabrera, Christina Markert, Elena
Bratkovskaya | Probing the hot and dense nuclear matter with $K^*,\bar{K}^*$ vector
mesons | 24 pages, 34 figures, extended version as published in Phys. Rev. C | Phys. Rev. C 99, 024914 (2019) | 10.1103/PhysRevC.99.024914 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate probing the hot and dense nuclear matter with strange vector
mesons ($K^*, \bar{K}^*$). Our analysis is based on PHSD which incorporates
partonic and hadronic dof and describes the full dynamics of HICs. This allows
to study the $K^*$ and $\bar{K}^*$ meson formation from the QGP and the
in-medium effects related to the modification of their properties during the
propagation in dense and hot matter. We employ relativistic Breit-Wigner
spectral functions for the $K^*,\bar{K}^*$ mesons with self-energies obtained
from a G-matrix approach to study the role of in-medium effects on the $K^*$
and $\bar{K}^*$ meson dynamics in HIC from FAIR/NICA to LHC energies. According
to our analysis most of the final $K^*/\bar{K}^*$s, that can be observed
experimentally, are produced during the late hadronic phase and stem dominantly
from the $K (\bar{K}) + \pi \to K^*(\bar{K}^*)$ formation channel. The amount
of $K^*/\bar{K}^*$s originating from the QGP channel is comparatively small
even at LHC energies and such $K^*/\bar{K}^*$s can hardly be reconstructed
experimentally due to the rescattering of final pions and (anti-)kaons. This
mirrors the results from our previous study on the strange vector-meson
production in HICs at RHIC energies. The influence of the in-medium effects on
the dynamics of the $K^*/\bar{K}^*$ is rather small since they are mostly
produced at low baryon densities. Additional cuts on the shape of the observed
signal and the range of the invariant mass region of the $K^*/\bar{K}^*$ also
affect the final spectra. We demonstrate that the $K^*/\bar{K}^*$ in-medium
effects are more visible at lower beam energy, e.g. FAIR/NICA and BES RHIC
energies, where the production of $K^*/\bar{K}^*$s occurs at larger baryon
densities. Finally, we present the experimental procedures to extract
information on the in-medium masses and widths by fitting final mass spectra at
LHC energies.
| [
{
"created": "Fri, 30 Jun 2017 22:41:25 GMT",
"version": "v1"
},
{
"created": "Tue, 11 Jul 2017 19:29:04 GMT",
"version": "v2"
},
{
"created": "Mon, 25 Feb 2019 16:39:53 GMT",
"version": "v3"
}
] | 2019-03-06 | [
[
"Ilner",
"Andrej",
""
],
[
"Blair",
"Justin",
""
],
[
"Cabrera",
"Daniel",
""
],
[
"Markert",
"Christina",
""
],
[
"Bratkovskaya",
"Elena",
""
]
] | We investigate probing the hot and dense nuclear matter with strange vector mesons ($K^*, \bar{K}^*$). Our analysis is based on PHSD which incorporates partonic and hadronic dof and describes the full dynamics of HICs. This allows to study the $K^*$ and $\bar{K}^*$ meson formation from the QGP and the in-medium effects related to the modification of their properties during the propagation in dense and hot matter. We employ relativistic Breit-Wigner spectral functions for the $K^*,\bar{K}^*$ mesons with self-energies obtained from a G-matrix approach to study the role of in-medium effects on the $K^*$ and $\bar{K}^*$ meson dynamics in HIC from FAIR/NICA to LHC energies. According to our analysis most of the final $K^*/\bar{K}^*$s, that can be observed experimentally, are produced during the late hadronic phase and stem dominantly from the $K (\bar{K}) + \pi \to K^*(\bar{K}^*)$ formation channel. The amount of $K^*/\bar{K}^*$s originating from the QGP channel is comparatively small even at LHC energies and such $K^*/\bar{K}^*$s can hardly be reconstructed experimentally due to the rescattering of final pions and (anti-)kaons. This mirrors the results from our previous study on the strange vector-meson production in HICs at RHIC energies. The influence of the in-medium effects on the dynamics of the $K^*/\bar{K}^*$ is rather small since they are mostly produced at low baryon densities. Additional cuts on the shape of the observed signal and the range of the invariant mass region of the $K^*/\bar{K}^*$ also affect the final spectra. We demonstrate that the $K^*/\bar{K}^*$ in-medium effects are more visible at lower beam energy, e.g. FAIR/NICA and BES RHIC energies, where the production of $K^*/\bar{K}^*$s occurs at larger baryon densities. Finally, we present the experimental procedures to extract information on the in-medium masses and widths by fitting final mass spectra at LHC energies. |
2103.09665 | Marius Utheim | Christian Bierlich, Torbj\"orn Sj\"ostrand, Marius Utheim | Hadronic Rescattering in pA and AA Collisions | 38 pages, 16 figures | null | 10.1140/epja/s10050-021-00543-3 | LU TP 21-08, MCnet-21-03 | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In a recent article we presented a model for hadronic rescattering, and some
results were shown for pp collisions at LHC energies. In order to extend the
studies to pA and AA collisions, the Angantyr model for heavy-ion collisions is
taken as the starting point. Both these models are implemented within the
general-purpose Monte Carlo event generator Pythia, which makes the matching
reasonably straightforward, and allows for detailed studies of the full
space--time evolution. The rescattering rate is significantly higher than in
pp, especially for central AA collisions, where the typical primary hadron
rescatters several times. We study the impact of rescattering on a number of
distributions, such as pT and eta spectra, and the space--time evolution of the
whole collision process. Notably rescattering is shown to give a significant
contribution to elliptic flow in XeXe and PbPb, and to give a nontrivial impact
on charm production.
| [
{
"created": "Wed, 17 Mar 2021 14:04:55 GMT",
"version": "v1"
}
] | 2021-07-28 | [
[
"Bierlich",
"Christian",
""
],
[
"Sjöstrand",
"Torbjörn",
""
],
[
"Utheim",
"Marius",
""
]
] | In a recent article we presented a model for hadronic rescattering, and some results were shown for pp collisions at LHC energies. In order to extend the studies to pA and AA collisions, the Angantyr model for heavy-ion collisions is taken as the starting point. Both these models are implemented within the general-purpose Monte Carlo event generator Pythia, which makes the matching reasonably straightforward, and allows for detailed studies of the full space--time evolution. The rescattering rate is significantly higher than in pp, especially for central AA collisions, where the typical primary hadron rescatters several times. We study the impact of rescattering on a number of distributions, such as pT and eta spectra, and the space--time evolution of the whole collision process. Notably rescattering is shown to give a significant contribution to elliptic flow in XeXe and PbPb, and to give a nontrivial impact on charm production. |
1306.6631 | Iftah Galon | Iftah Galon, Gilad Perez, and Yael Shadmi | Non-Degenerate Squarks from Flavored Gauge Mediation | 16 pages, 2 figures. v2: Typo corrected, references added | null | 10.1007/JHEP09(2013)117 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the squark spectra of Flavored Gauge Mediation Models, in which
messenger-matter superpotential couplings generate new, generation-dependent
contributions to the squark masses. The new couplings are controlled by the
same flavor symmetry that explains the fermion masses, leading to excellent
alignment of the quark and squark mass matrices. This allows for large squark
mass splittings consistent with all flavor bounds. In particular,
second-generation squarks are often significantly lighter than the
first-generation squarks. As squark production at the LHC is dominated by the
up- and down-squarks and the efficiencies for squark searches increase with
their masses, the charm and/or strange squark masses can be well below the
current LHC bounds. At the same time, even with a single set of messengers, the
models can generate large stop mixings which result in large loop contributions
to the Higgs mass.
| [
{
"created": "Thu, 27 Jun 2013 20:00:03 GMT",
"version": "v1"
},
{
"created": "Mon, 1 Jul 2013 19:52:15 GMT",
"version": "v2"
}
] | 2015-06-16 | [
[
"Galon",
"Iftah",
""
],
[
"Perez",
"Gilad",
""
],
[
"Shadmi",
"Yael",
""
]
] | We study the squark spectra of Flavored Gauge Mediation Models, in which messenger-matter superpotential couplings generate new, generation-dependent contributions to the squark masses. The new couplings are controlled by the same flavor symmetry that explains the fermion masses, leading to excellent alignment of the quark and squark mass matrices. This allows for large squark mass splittings consistent with all flavor bounds. In particular, second-generation squarks are often significantly lighter than the first-generation squarks. As squark production at the LHC is dominated by the up- and down-squarks and the efficiencies for squark searches increase with their masses, the charm and/or strange squark masses can be well below the current LHC bounds. At the same time, even with a single set of messengers, the models can generate large stop mixings which result in large loop contributions to the Higgs mass. |
2102.11280 | Samuel Witte | Andrea Caputo, Samuel J. Witte, Diego Blas, and Paolo Pani | Electromagnetic Signatures of Dark Photon Superradiance | v2: Minor changes, matches published version. v1: 14 pages, 3
figures, appendix | Phys. Rev. D 104, 043006 (2021) | 10.1103/PhysRevD.104.043006 | null | hep-ph astro-ph.CO gr-qc hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Black hole superradiance is a powerful tool in the search for ultra-light
bosons. Constraints on the existence of such particles have been derived from
the observation of highly spinning black holes, absence of continuous
gravitational-wave signals, and of the associated stochastic background.
However, these constraints are only strictly speaking valid in the limit where
the boson's interactions can be neglected. In this work we investigate the
extent to which the superradiant growth of an ultra-light dark photon can be
quenched via scattering processes with ambient electrons. For dark photon
masses $m_{\gamma^\prime} \gtrsim 10^{-17}\,{\rm eV}$, and for reasonable
values of the ambient electron number density, we find superradiance can be
quenched prior to extracting a significant fraction of the black-hole spin. For
sufficiently large $m_{\gamma^\prime}$ and small electron number densities, the
in-medium suppression of the kinetic mixing can be efficiently removed, and
quenching occurs for mixings $\chi_0 \gtrsim \mathcal{O}(10^{-8})$; at low
masses, however, in-medium effects strongly inhibit otherwise efficient
scattering processes from dissipating energy. Intriguingly, this quenching
leads to a time- and energy-oscillating electromagnetic signature, with
luminosities potentially extending up to $\sim 10^{57}\,{\rm erg / s}$,
suggesting that such events should be detectable with existing telescopes. As a
byproduct we also show that superradiance cannot be used to constrain a small
mass for the Standard Model photon.
| [
{
"created": "Mon, 22 Feb 2021 19:00:00 GMT",
"version": "v1"
},
{
"created": "Thu, 18 Nov 2021 07:23:19 GMT",
"version": "v2"
}
] | 2021-11-19 | [
[
"Caputo",
"Andrea",
""
],
[
"Witte",
"Samuel J.",
""
],
[
"Blas",
"Diego",
""
],
[
"Pani",
"Paolo",
""
]
] | Black hole superradiance is a powerful tool in the search for ultra-light bosons. Constraints on the existence of such particles have been derived from the observation of highly spinning black holes, absence of continuous gravitational-wave signals, and of the associated stochastic background. However, these constraints are only strictly speaking valid in the limit where the boson's interactions can be neglected. In this work we investigate the extent to which the superradiant growth of an ultra-light dark photon can be quenched via scattering processes with ambient electrons. For dark photon masses $m_{\gamma^\prime} \gtrsim 10^{-17}\,{\rm eV}$, and for reasonable values of the ambient electron number density, we find superradiance can be quenched prior to extracting a significant fraction of the black-hole spin. For sufficiently large $m_{\gamma^\prime}$ and small electron number densities, the in-medium suppression of the kinetic mixing can be efficiently removed, and quenching occurs for mixings $\chi_0 \gtrsim \mathcal{O}(10^{-8})$; at low masses, however, in-medium effects strongly inhibit otherwise efficient scattering processes from dissipating energy. Intriguingly, this quenching leads to a time- and energy-oscillating electromagnetic signature, with luminosities potentially extending up to $\sim 10^{57}\,{\rm erg / s}$, suggesting that such events should be detectable with existing telescopes. As a byproduct we also show that superradiance cannot be used to constrain a small mass for the Standard Model photon. |
1607.08088 | Gergely G\'abor Barnaf\"oldi | Szilvia Karsai, Gergely G\'abor Barnaf\"oldi, Emese Forg\'acs-Dajka,
and P\'eter P\'osfay | Correspondence of Many-flavor Limit and Kaluza-Klein Degrees of Freedom
in the Description of Compact Stars | 5 pages, 2 color figures, 1 table, Contribution to the CPOD 2016,
Wroclaw, Poland | null | null | null | hep-ph astro-ph.HE gr-qc | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the correspondence between non-interacting multi-hadron fermion
star equation of state in the many-flavor limit and the degrees of freedom of a
Kaluza\,--\,Klein compact star. Many flavors can be interpreted in this
framework as one extra compacti\-fied spatial dimension with various,
more-and-more massive hadron state excitations. The effect of increasing the
degrees of freedom was investigated on the equation of state and in connection
with the mass-radius relation, $M(R)$. The maximum mass of the star,
$M_{\mathrm{max}}$ were also calculated as a function of the maximum number of
excited states, $n$ and the size of the compactified extra dimension,
$R_{\mathrm{c}}$.
| [
{
"created": "Wed, 27 Jul 2016 13:48:44 GMT",
"version": "v1"
}
] | 2016-07-28 | [
[
"Karsai",
"Szilvia",
""
],
[
"Barnaföldi",
"Gergely Gábor",
""
],
[
"Forgács-Dajka",
"Emese",
""
],
[
"Pósfay",
"Péter",
""
]
] | We present the correspondence between non-interacting multi-hadron fermion star equation of state in the many-flavor limit and the degrees of freedom of a Kaluza\,--\,Klein compact star. Many flavors can be interpreted in this framework as one extra compacti\-fied spatial dimension with various, more-and-more massive hadron state excitations. The effect of increasing the degrees of freedom was investigated on the equation of state and in connection with the mass-radius relation, $M(R)$. The maximum mass of the star, $M_{\mathrm{max}}$ were also calculated as a function of the maximum number of excited states, $n$ and the size of the compactified extra dimension, $R_{\mathrm{c}}$. |
hep-ph/0508232 | Alexander Kovner | Alex Kovner (University of Connecticut) | High Energy Evolution - The Wave Function Point of View | Lectures given at XLV Cracow School of Theoretical Physics, Zakopane
June 2005; 41 pages | Acta Phys.Polon. B36 (2005) 3551-3592 | null | null | hep-ph | null | These lectures discuss aspects of high energy evolution in QCD. This includes
the derivation of the JIMWLK equation, basic physics of its solutions and
recent work on inclusion of Pomeron loops. The entire discussion is given in
the Hamiltonian framework which gives direct access to the evolution of
hadronic wave function under Lorentz boost.
| [
{
"created": "Mon, 22 Aug 2005 13:15:12 GMT",
"version": "v1"
},
{
"created": "Wed, 24 Aug 2005 14:28:47 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Kovner",
"Alex",
"",
"University of Connecticut"
]
] | These lectures discuss aspects of high energy evolution in QCD. This includes the derivation of the JIMWLK equation, basic physics of its solutions and recent work on inclusion of Pomeron loops. The entire discussion is given in the Hamiltonian framework which gives direct access to the evolution of hadronic wave function under Lorentz boost. |
hep-ph/0312266 | Lance Dixon | Charalampos Anastasiou, Lance Dixon, Kirill Melnikov, Frank Petriello | High-precision QCD at hadron colliders: electroweak gauge boson rapidity
distributions at NNLO | 47 pages, 17 figures. Minor typos, 1 reference corrected | Phys.Rev.D69:094008,2004 | 10.1103/PhysRevD.69.094008 | SLAC-PUB-10288, UH-511-1042-03 | hep-ph hep-ex | null | We compute the rapidity distributions of W and Z bosons produced at the
Tevatron and the LHC through next-to-next-to leading order in QCD. Our results
demonstrate remarkable stability with respect to variations of the
factorization and renormalization scales for all values of rapidity accessible
in current and future experiments. These processes are therefore
``gold-plated'': current theoretical knowledge yields QCD predictions accurate
to better than one percent. These results strengthen the proposal to use W and
Z production to determine parton-parton luminosities and constrain parton
distribution functions at the LHC. For example, LHC data should easily be able
to distinguish the central parton distribution fit obtained by MRST from that
obtained by Alekhin.
| [
{
"created": "Thu, 18 Dec 2003 20:10:19 GMT",
"version": "v1"
},
{
"created": "Wed, 31 Mar 2004 00:46:40 GMT",
"version": "v2"
}
] | 2010-11-15 | [
[
"Anastasiou",
"Charalampos",
""
],
[
"Dixon",
"Lance",
""
],
[
"Melnikov",
"Kirill",
""
],
[
"Petriello",
"Frank",
""
]
] | We compute the rapidity distributions of W and Z bosons produced at the Tevatron and the LHC through next-to-next-to leading order in QCD. Our results demonstrate remarkable stability with respect to variations of the factorization and renormalization scales for all values of rapidity accessible in current and future experiments. These processes are therefore ``gold-plated'': current theoretical knowledge yields QCD predictions accurate to better than one percent. These results strengthen the proposal to use W and Z production to determine parton-parton luminosities and constrain parton distribution functions at the LHC. For example, LHC data should easily be able to distinguish the central parton distribution fit obtained by MRST from that obtained by Alekhin. |
1109.5050 | Bernard Pire | I. V. Anikin, A. Besse, D.Yu. Ivanov, B. Pire, L. Szymanowski, S.
Wallon | On high energy exclusive leptoproduction of the rho meson up to twist 3 | 3 pages, 4 figures, To be published in the proceedings of the 2011
Europhysics Conference on High Energy Physics-HEP 2011, July 21-27, 2011
Grenoble, Rhone-Alpes, France | null | null | CPHT-PC063.0911, LPT-11-82 | hep-ph hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The Regge inspired k_T-factorization scheme expresses the scattering
amplitude for exclusive leptoproduction of a light vector meson rho in terms of
two impact factors, one for the gamma* - rho transition and the other one for
the nucleon to nucleon transition, with, at leading order, a two "reggeized"
gluon exchange in the t-channel. We report here on a recent phenomenological
study where we apply a previously developped scheme which consistently takes
into account the twist 3 distribution amplitudes for transversely polarized rho
meson. The computation of the gamma* to rho impact factor are performed within
collinear factorization of QCD, up to the twist 3 level, based on the Collinear
Factorization scheme applied to the amplitudes gamma*g to g rho .
Our results are in good agreement with high energy experimental data for the
ratios of helicity amplitudes.
| [
{
"created": "Fri, 23 Sep 2011 12:20:47 GMT",
"version": "v1"
}
] | 2011-09-26 | [
[
"Anikin",
"I. V.",
""
],
[
"Besse",
"A.",
""
],
[
"Ivanov",
"D. Yu.",
""
],
[
"Pire",
"B.",
""
],
[
"Szymanowski",
"L.",
""
],
[
"Wallon",
"S.",
""
]
] | The Regge inspired k_T-factorization scheme expresses the scattering amplitude for exclusive leptoproduction of a light vector meson rho in terms of two impact factors, one for the gamma* - rho transition and the other one for the nucleon to nucleon transition, with, at leading order, a two "reggeized" gluon exchange in the t-channel. We report here on a recent phenomenological study where we apply a previously developped scheme which consistently takes into account the twist 3 distribution amplitudes for transversely polarized rho meson. The computation of the gamma* to rho impact factor are performed within collinear factorization of QCD, up to the twist 3 level, based on the Collinear Factorization scheme applied to the amplitudes gamma*g to g rho . Our results are in good agreement with high energy experimental data for the ratios of helicity amplitudes. |
hep-ph/9904425 | Hooman Davoudiasl | Hooman Davoudiasl | gamma gamma -> gamma gamma as a Test of Weak Scale Quantum Gravity at
the NLC | 17 pages, 7 figures, Latex. Revised numerical results. General
conclusions have not changed, however, the quantitative results are somewhat
different | Phys.Rev. D60 (1999) 084022 | 10.1103/PhysRevD.60.084022 | SLAC-PUB-8121 | hep-ph | null | Recently, it has been proposed that the fundamental scale of quantum gravity
can be close to the weak scale if there are large extra dimensions. This
proposal has important phenomenological implications for processes at the TeV
scale. We study the process gamma gamma -> gamma gamma, assuming an ultraviolet
cutoff M_S \sim 1 TeV for the effective gravity theory. We find that, at center
of mass energies \sqrt(s) \sim 1 TeV, the contribution of gravitationally
mediated scattering to the cross section is comparable to that coming from the
one-loop Feynman diagrams of the Standard Model. We thus conclude that the
effects of weak scale quantum gravity can be studied at the Next Linear
Collider (NLC), in the photon collider mode. Our results suggest that, for
typical proposed NLC energies and luminosities, the range 1 TeV \lsim M_S \lsim
10 TeV can be probed.
| [
{
"created": "Thu, 22 Apr 1999 21:58:18 GMT",
"version": "v1"
},
{
"created": "Tue, 11 May 1999 02:08:40 GMT",
"version": "v2"
},
{
"created": "Tue, 15 Jun 1999 21:37:08 GMT",
"version": "v3"
}
] | 2009-10-31 | [
[
"Davoudiasl",
"Hooman",
""
]
] | Recently, it has been proposed that the fundamental scale of quantum gravity can be close to the weak scale if there are large extra dimensions. This proposal has important phenomenological implications for processes at the TeV scale. We study the process gamma gamma -> gamma gamma, assuming an ultraviolet cutoff M_S \sim 1 TeV for the effective gravity theory. We find that, at center of mass energies \sqrt(s) \sim 1 TeV, the contribution of gravitationally mediated scattering to the cross section is comparable to that coming from the one-loop Feynman diagrams of the Standard Model. We thus conclude that the effects of weak scale quantum gravity can be studied at the Next Linear Collider (NLC), in the photon collider mode. Our results suggest that, for typical proposed NLC energies and luminosities, the range 1 TeV \lsim M_S \lsim 10 TeV can be probed. |
hep-ph/9911393 | Stefan Groote Dr. | S. Groote, J.G. K\"orner and A.A. Pivovarov | $O(\alpha_s)$ corrections to the correlator of finite mass baryon
currents | 12 pages, 2 Postscript figures | Phys.Rev.D61:071501,2000 | 10.1103/PhysRevD.61.071501 | MZ-TH/99-49, CLNS/99-1647 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present analytical next-to-leading order results for the correlator of
baryonic currents at the three loop level with one finite mass quark. We obtain
the massless and the HQET limit of the correlator from the general formula as
particular cases. We also give explicit expressions for the moments of the
spectral density.
| [
{
"created": "Wed, 17 Nov 1999 21:10:11 GMT",
"version": "v1"
},
{
"created": "Thu, 20 Apr 2000 04:56:53 GMT",
"version": "v2"
},
{
"created": "Fri, 13 Oct 2017 07:55:54 GMT",
"version": "v3"
}
] | 2017-10-16 | [
[
"Groote",
"S.",
""
],
[
"Körner",
"J. G.",
""
],
[
"Pivovarov",
"A. A.",
""
]
] | We present analytical next-to-leading order results for the correlator of baryonic currents at the three loop level with one finite mass quark. We obtain the massless and the HQET limit of the correlator from the general formula as particular cases. We also give explicit expressions for the moments of the spectral density. |
hep-ph/9212289 | Aneesh V. Manohar | Zachary Guralnik and Aneesh V. Manohar | QCD Mass Inequalities in the Heavy Quark Limit | 10 pages, 0 figures, uses harvmac | Phys.Lett.B302:103-107,1993 | 10.1016/0370-2693(93)90642-U | CERN-TH.6766/92, UCSD/PTH 92-45 | hep-ph | null | QCD inequalities are derived for the masses of mesons and baryons containing
a single heavy quark using the heavy quark effective field theory. A rigorous
lower bound is obtained for the $\bar\Lambda$ parameters of the heavy quark
effective theory that parameterize $1/m$ corrections, $\bar\Lambda$ > 237 MeV
for mesons, and $\bar \Lambda > 657$ MeV for baryons. The inequalities on
$\bar\Lambda$ imply the inequalities $m_c < 1627$ MeV and $m_b < 5068$ MeV for
the mass parameters of the heavy quark effective field theory.
| [
{
"created": "Mon, 21 Dec 1992 10:31:17 GMT",
"version": "v1"
}
] | 2011-01-25 | [
[
"Guralnik",
"Zachary",
""
],
[
"Manohar",
"Aneesh V.",
""
]
] | QCD inequalities are derived for the masses of mesons and baryons containing a single heavy quark using the heavy quark effective field theory. A rigorous lower bound is obtained for the $\bar\Lambda$ parameters of the heavy quark effective theory that parameterize $1/m$ corrections, $\bar\Lambda$ > 237 MeV for mesons, and $\bar \Lambda > 657$ MeV for baryons. The inequalities on $\bar\Lambda$ imply the inequalities $m_c < 1627$ MeV and $m_b < 5068$ MeV for the mass parameters of the heavy quark effective field theory. |
hep-ph/0011182 | Wanyun Zhao | Wanyun Zhao and F.C. Khanna (Univ. of Alberta, Canada) | Screening length, dispersion relations and quark potential in thermo
field dynamics | 16 pages, RevTex, 3 Postscript figures, submitted to Phys. Rev. D | Int.J.Mod.Phys. A17 (2002) 2911-2923 | 10.1142/S0217751X02010972 | null | hep-ph | null | The screening length in a quark-gluon plasma, the dispersion relations of
thermal gluon self-energy and the quark potential at high temperature are
studied within thermo field dynamics framework. By calculation of the real and
imaginary parts, of the gluon self-energy in one-loop order in thermo field
dynamics, we obtain an expression for the screening length in a quark-gluon
plasma and the dispersion relation between the real and imaginary parts. At
high temperature, using photon exchange between electron-positron in a skeleton
expansion and ladder approximation, the screened Coulomb potential is obtained,
and using one-gluon and two-gluon exchange between a quark-antiquark, we get an
expression for the screened quark potential up to $O(g amplitudes of generic
process taking place in a many body system in equilibrium at temperature T. The
relationship of the scattering and decay amplitudes as calculated in Thermo
Field Dynamics to the conventional techniques is established. It is shown that
in many cases the calculations are relatively easy in TFD.
| [
{
"created": "Tue, 14 Nov 2000 21:34:47 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Zhao",
"Wanyun",
"",
"Univ. of Alberta, Canada"
],
[
"Khanna",
"F. C.",
"",
"Univ. of Alberta, Canada"
]
] | The screening length in a quark-gluon plasma, the dispersion relations of thermal gluon self-energy and the quark potential at high temperature are studied within thermo field dynamics framework. By calculation of the real and imaginary parts, of the gluon self-energy in one-loop order in thermo field dynamics, we obtain an expression for the screening length in a quark-gluon plasma and the dispersion relation between the real and imaginary parts. At high temperature, using photon exchange between electron-positron in a skeleton expansion and ladder approximation, the screened Coulomb potential is obtained, and using one-gluon and two-gluon exchange between a quark-antiquark, we get an expression for the screened quark potential up to $O(g amplitudes of generic process taking place in a many body system in equilibrium at temperature T. The relationship of the scattering and decay amplitudes as calculated in Thermo Field Dynamics to the conventional techniques is established. It is shown that in many cases the calculations are relatively easy in TFD. |
1210.6199 | Rita Bernabei | R. Bernabei (1), P. Belli (1), F. Cappella (2), V. Caracciolo (3), R.
Cerulli (3), C. J. Dai (4), A. d'Angelo (2), A. Di Marco (1), H. L. He (4),
A. Incicchitti (2), X. H. Ma (4), F. Montecchia (1,5), X. D. Sheng (4), R. G.
Wang (4), Z. P. Ye (4,6) ((1) Univ. and INFN Roma Tor Vergata, (2) Univ. and
INFN Roma, (3) INFN LNGS, (4) IHEP Beijing, (5) Univ. Tor Vergata, (6) Univ.
Jing Gangshan) | Comment on "On an unverified nuclear decay and its role in the DAMA
experiment" (arXiv:1210.5501) | null | null | null | null | hep-ph astro-ph.HE nucl-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We briefly remind references and arguments, already discussed in the past,
which confute erroneous claims in arXiv:1210.5501.
| [
{
"created": "Tue, 23 Oct 2012 11:11:30 GMT",
"version": "v1"
}
] | 2012-10-24 | [
[
"Bernabei",
"R.",
""
],
[
"Belli",
"P.",
""
],
[
"Cappella",
"F.",
""
],
[
"Caracciolo",
"V.",
""
],
[
"Cerulli",
"R.",
""
],
[
"Dai",
"C. J.",
""
],
[
"d'Angelo",
"A.",
""
],
[
"Di Marco",
"A.",
""
],
[
"He",
"H. L.",
""
],
[
"Incicchitti",
"A.",
""
],
[
"Ma",
"X. H.",
""
],
[
"Montecchia",
"F.",
""
],
[
"Sheng",
"X. D.",
""
],
[
"Wang",
"R. G.",
""
],
[
"Ye",
"Z. P.",
""
]
] | We briefly remind references and arguments, already discussed in the past, which confute erroneous claims in arXiv:1210.5501. |
2210.07735 | Prudhvi N. Bhattiprolu | Prudhvi N. Bhattiprolu, Stephen P. Martin, James D. Wells | Statistical significances and projections for proton decay experiments | 58 pages. v2: published in PRD with minor revisions | null | 10.1103/PhysRevD.107.055016 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the statistical significances for exclusion and discovery of proton
decay at current and future neutrino detectors. Various counterintuitive flaws
associated with frequentist and modified frequentist statistical measures of
significance for multi-channel counting experiments are discussed in a general
context and illustrated with examples. We argue in favor of conservative
Bayesian-motivated statistical measures, and as an application we employ these
measures to obtain the current lower limits on proton partial lifetime at
various confidence levels, based on Super-Kamiokande's data, generalizing the
90\% CL published limits. Finally, we present projections for exclusion and
discovery reaches for proton partial lifetimes in $p \rightarrow \overline \nu
K^+$ and $p \rightarrow e^+ \pi^0$ decay channels at Hyper-Kamiokande, DUNE,
JUNO, and THEIA.
| [
{
"created": "Fri, 14 Oct 2022 12:14:19 GMT",
"version": "v1"
},
{
"created": "Tue, 21 Mar 2023 20:11:24 GMT",
"version": "v2"
}
] | 2023-03-29 | [
[
"Bhattiprolu",
"Prudhvi N.",
""
],
[
"Martin",
"Stephen P.",
""
],
[
"Wells",
"James D.",
""
]
] | We study the statistical significances for exclusion and discovery of proton decay at current and future neutrino detectors. Various counterintuitive flaws associated with frequentist and modified frequentist statistical measures of significance for multi-channel counting experiments are discussed in a general context and illustrated with examples. We argue in favor of conservative Bayesian-motivated statistical measures, and as an application we employ these measures to obtain the current lower limits on proton partial lifetime at various confidence levels, based on Super-Kamiokande's data, generalizing the 90\% CL published limits. Finally, we present projections for exclusion and discovery reaches for proton partial lifetimes in $p \rightarrow \overline \nu K^+$ and $p \rightarrow e^+ \pi^0$ decay channels at Hyper-Kamiokande, DUNE, JUNO, and THEIA. |
hep-ph/9409449 | Department of Theoretical Physics | A.Ya.Parkhomenko and A.D.Smirnov | On Collinearization of Quarks in Quark-Gluon Decays of Heavy
Orthoquarqonia | (talk given at the VIII International Seminar "Quarks-94", Vladimir,
Russia, May 11-18, 1994), 6 pages, LaTeX (uses world_sci.sty), (three figures
may be received by request), Yaroslavl, Yaroslavl State University preprint
YARU-HE-94/07 | null | null | null | hep-ph | null | The decay of heavy orthoquarkonium into quark-antiquark pair and two gluons
is considered. The differential probability of the decay in the tree
approximation is calculated and the final quark mass influence on the quark and
gluon distribution functions is studied. It is shown that the collinear
strengthening of the bottomonium decay probability takes place at the $u \bar
u$-, $d \bar d$- and $s \bar s$- pair production and is absent at the $c \bar
c$- production.
| [
{
"created": "Fri, 30 Sep 1994 09:21:30 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Parkhomenko",
"A. Ya.",
""
],
[
"Smirnov",
"A. D.",
""
]
] | The decay of heavy orthoquarkonium into quark-antiquark pair and two gluons is considered. The differential probability of the decay in the tree approximation is calculated and the final quark mass influence on the quark and gluon distribution functions is studied. It is shown that the collinear strengthening of the bottomonium decay probability takes place at the $u \bar u$-, $d \bar d$- and $s \bar s$- pair production and is absent at the $c \bar c$- production. |
1209.6083 | Sarah Andreas | Sarah Andreas, Carsten Niebuhr and Andreas Ringwald | New Limits on Hidden Photons from Past Electron Beam Dumps | 6 pages, 3 figures; v2: figures updated, references added, matches
version published in PRD | Phys.Rev.D86:095019,2012 | 10.1103/PhysRevD.86.095019 | DESY 12-054 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Hidden sectors with light extra U(1) gauge bosons, so-called hidden photons,
have recently attracted some attention because they are a common feature of
physics beyond the Standard Model like string theory and supersymmetry and
additionally are phenomenologically of great interest regarding recent
astrophysical observations. The hidden photon is already constrained by various
laboratory experiments and presently searched for in running as well as
upcoming experiments. We summarize the current status of limits on hidden
photons from past electron beam dump experiments including two new limits from
such experiments at the High Energy Accelerator Research Organization in Japan
(KEK) and the Laboratoire de l'accelerateur lineaire (LAL, Orsay) that have so
far not been considered. All our limits take into account the experimental
acceptances obtained from Monte Carlo simulations.
| [
{
"created": "Wed, 26 Sep 2012 21:24:06 GMT",
"version": "v1"
},
{
"created": "Wed, 14 Nov 2012 09:03:01 GMT",
"version": "v2"
}
] | 2012-11-20 | [
[
"Andreas",
"Sarah",
""
],
[
"Niebuhr",
"Carsten",
""
],
[
"Ringwald",
"Andreas",
""
]
] | Hidden sectors with light extra U(1) gauge bosons, so-called hidden photons, have recently attracted some attention because they are a common feature of physics beyond the Standard Model like string theory and supersymmetry and additionally are phenomenologically of great interest regarding recent astrophysical observations. The hidden photon is already constrained by various laboratory experiments and presently searched for in running as well as upcoming experiments. We summarize the current status of limits on hidden photons from past electron beam dump experiments including two new limits from such experiments at the High Energy Accelerator Research Organization in Japan (KEK) and the Laboratoire de l'accelerateur lineaire (LAL, Orsay) that have so far not been considered. All our limits take into account the experimental acceptances obtained from Monte Carlo simulations. |
2109.14898 | Michele Maltoni | Kim Goldhagen, Michele Maltoni, Shayne Reichard, Thomas Schwetz | Testing sterile neutrino mixing with present and future solar neutrino
data | 24 pages, 8 figures, 4 tables. Accepted for publication in EPJC | null | 10.1140/epjc/s10052-022-10052-2 | IFT-UAM/CSIC-21-104 | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | We investigate the sensitivity of solar neutrino data to mixing of sterile
neutrinos with masses $\gtrsim$ eV. For current data, we perform a
Feldman-Cousins analysis to derive a robust limit on the sterile neutrino
mixing. The solar neutrino limit excludes significant regions of the parameter
space relevant to hints from reactor and radioactive gallium source
experiments. We then study the sensitivity of upcoming solar neutrino data,
most notably elastic neutrino-electron scattering in the DARWIN and DUNE
experiments as well as coherent neutrino-nucleus scattering in DARWIN. These
high precision measurements will increase the sensitivity to sterile neutrino
mixing by about a factor of 4.5 compared to present limits. As a by-product, we
introduce a simplified solar neutrino analysis using only four data points: the
low- and high-energy $\nu_e$ survival and transition probabilities. We show
that this simplified analysis is in excellent agreement with a full solar
neutrino analysis; it is very easy to handle numerically and can be applied to
any new physics model in which the energy dependence of the $\nu_e$ transition
probabilities is not significantly modified.
| [
{
"created": "Thu, 30 Sep 2021 07:44:38 GMT",
"version": "v1"
},
{
"created": "Fri, 28 Jan 2022 09:29:07 GMT",
"version": "v2"
}
] | 2022-02-23 | [
[
"Goldhagen",
"Kim",
""
],
[
"Maltoni",
"Michele",
""
],
[
"Reichard",
"Shayne",
""
],
[
"Schwetz",
"Thomas",
""
]
] | We investigate the sensitivity of solar neutrino data to mixing of sterile neutrinos with masses $\gtrsim$ eV. For current data, we perform a Feldman-Cousins analysis to derive a robust limit on the sterile neutrino mixing. The solar neutrino limit excludes significant regions of the parameter space relevant to hints from reactor and radioactive gallium source experiments. We then study the sensitivity of upcoming solar neutrino data, most notably elastic neutrino-electron scattering in the DARWIN and DUNE experiments as well as coherent neutrino-nucleus scattering in DARWIN. These high precision measurements will increase the sensitivity to sterile neutrino mixing by about a factor of 4.5 compared to present limits. As a by-product, we introduce a simplified solar neutrino analysis using only four data points: the low- and high-energy $\nu_e$ survival and transition probabilities. We show that this simplified analysis is in excellent agreement with a full solar neutrino analysis; it is very easy to handle numerically and can be applied to any new physics model in which the energy dependence of the $\nu_e$ transition probabilities is not significantly modified. |
0802.2680 | Jose Ramon Espinosa | A. Delgado, J. R. Espinosa, J. M. No and M. Quiros | The Higgs as a Portal to Plasmon-like Unparticle Excitations | 12 LaTeX pages, 2 figures | JHEP0804:028,2008 | 10.1088/1126-6708/2008/04/028 | IFT-UAM/CSIC-08-09, CERN-PH-TH/2008-033, UAB-FT-639 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A renormalizable coupling between the Higgs and a scalar unparticle operator
O_U of non-integer dimension d_U<2 triggers, after electroweak symmetry
breaking, an infrared divergent vacuum expectation value for O_U. Such IR
divergence should be tamed before any phenomenological implications of the
Higgs-unparticle interplay can be drawn. In this paper we present a novel
mechanism to cure that IR divergence through (scale-invariant) unparticle
self-interactions, which has properties qualitatively different from the
mechanism considered previously. Besides finding a mass gap in the unparticle
continuum we also find an unparticle pole reminiscent of a plasmon resonance.
Such unparticle features could be explored experimentally through their mixing
with the Higgs boson.
| [
{
"created": "Tue, 19 Feb 2008 16:47:58 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Delgado",
"A.",
""
],
[
"Espinosa",
"J. R.",
""
],
[
"No",
"J. M.",
""
],
[
"Quiros",
"M.",
""
]
] | A renormalizable coupling between the Higgs and a scalar unparticle operator O_U of non-integer dimension d_U<2 triggers, after electroweak symmetry breaking, an infrared divergent vacuum expectation value for O_U. Such IR divergence should be tamed before any phenomenological implications of the Higgs-unparticle interplay can be drawn. In this paper we present a novel mechanism to cure that IR divergence through (scale-invariant) unparticle self-interactions, which has properties qualitatively different from the mechanism considered previously. Besides finding a mass gap in the unparticle continuum we also find an unparticle pole reminiscent of a plasmon resonance. Such unparticle features could be explored experimentally through their mixing with the Higgs boson. |
2110.05602 | Odilon Ardizzon Mattos | O. A. Mattos, T. Frederico, C. H. Lenzi, M. Dutra, O. Louren\c{c}o | PNJL model at zero temperature: three-flavor case | 14 pages, 11 figures. Submitted to Physical Review D | Phys. Rev. D 104, 116001 (2021) | 10.1103/PhysRevD.104.116001 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We propose a three-flavor version of the Polyakov-Nambu-Jona-Lasino (PNJL)
model at zero temperature regime, by implementing a traced Polyakov loop
($\Phi$) dependence in the scalar, vector and 't Hooft channel strengths. We
study the thermodynamics of this model, named as PNJL0, with special attention
for the first order confinement/deconfinement phase transition for which $\Phi$
is the order parameter. For the symmetric quark matter case, an interesting
feature observed is a strong reduction of the constituent strange quark mass
($M_s$) at the chemical potential related to point where deconfinement takes
place. The emergence of $\Phi$ favors the restoration of chiral symmetry even
for the strange quark. We also investigate the charge neutral system of quarks
and leptons in weak equilibrium. As an application, we construct a hadron-quark
phase transition with a density dependent hadronic model coupled to the SU(3)
PNJL0 model. In this case, the quark side is composed by deconfined particles.
This approach is used to determine mass-radius profiles compatible with recent
data from the Neutron Star Interior Composition Explorer (NICER) mission.
| [
{
"created": "Mon, 11 Oct 2021 20:48:53 GMT",
"version": "v1"
}
] | 2021-12-03 | [
[
"Mattos",
"O. A.",
""
],
[
"Frederico",
"T.",
""
],
[
"Lenzi",
"C. H.",
""
],
[
"Dutra",
"M.",
""
],
[
"Lourenço",
"O.",
""
]
] | We propose a three-flavor version of the Polyakov-Nambu-Jona-Lasino (PNJL) model at zero temperature regime, by implementing a traced Polyakov loop ($\Phi$) dependence in the scalar, vector and 't Hooft channel strengths. We study the thermodynamics of this model, named as PNJL0, with special attention for the first order confinement/deconfinement phase transition for which $\Phi$ is the order parameter. For the symmetric quark matter case, an interesting feature observed is a strong reduction of the constituent strange quark mass ($M_s$) at the chemical potential related to point where deconfinement takes place. The emergence of $\Phi$ favors the restoration of chiral symmetry even for the strange quark. We also investigate the charge neutral system of quarks and leptons in weak equilibrium. As an application, we construct a hadron-quark phase transition with a density dependent hadronic model coupled to the SU(3) PNJL0 model. In this case, the quark side is composed by deconfined particles. This approach is used to determine mass-radius profiles compatible with recent data from the Neutron Star Interior Composition Explorer (NICER) mission. |
1403.7516 | Jennifer Thompson | S. Hoeche, F. Krauss, S. Pozzorini, M. Schoenherr, J. M. Thompson, K.
C. Zapp | Triple vector boson production through Higgs-Strahlung with NLO multijet
merging | 12 pages, 4 figures | Phys. Rev. D 89, 093015 (2014) | 10.1103/PhysRevD.89.093015 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Triple gauge boson hadroproduction, in particular the production of three
$W$-bosons at the LHC, is considered at next-to leading order accuracy in QCD.
The NLO matrix elements are combined with parton showers. Multijet merging is
invoked such that NLO matrix elements with one additional jet are also
included. The studies here incorporate both the signal and all relevant
backgrounds for $VH$ production with the subsequent decay of the Higgs boson
into $W$-- or $\tau$--\-pairs. They have been performed using \SherpaOpenLoops
in combination with Collier.
| [
{
"created": "Fri, 28 Mar 2014 19:52:05 GMT",
"version": "v1"
},
{
"created": "Fri, 6 Jun 2014 09:39:42 GMT",
"version": "v2"
}
] | 2014-06-11 | [
[
"Hoeche",
"S.",
""
],
[
"Krauss",
"F.",
""
],
[
"Pozzorini",
"S.",
""
],
[
"Schoenherr",
"M.",
""
],
[
"Thompson",
"J. M.",
""
],
[
"Zapp",
"K. C.",
""
]
] | Triple gauge boson hadroproduction, in particular the production of three $W$-bosons at the LHC, is considered at next-to leading order accuracy in QCD. The NLO matrix elements are combined with parton showers. Multijet merging is invoked such that NLO matrix elements with one additional jet are also included. The studies here incorporate both the signal and all relevant backgrounds for $VH$ production with the subsequent decay of the Higgs boson into $W$-- or $\tau$--\-pairs. They have been performed using \SherpaOpenLoops in combination with Collier. |
hep-ph/9606307 | Nestor Armesto Perez | N. Armesto and M. A. Braun | The pomeron-pomeron interaction in the perturbative QCD | 12 pages in LaTeX plus 2 postscript files | Phys.Lett. B385 (1996) 284-292 | 10.1016/0370-2693(96)00884-2 | US-FT/27-96 | hep-ph | null | The pomeron-pomeron interaction is studied in the perturbative approach of
BFKL-Bartels. The total pomeron-pomeron cross-section is proportional to
$\alpha_{s}^{4}s^{\Delta}/\sqrt {t_{1}t_{2}}$ where $\sqrt{s}$ is the c.m.
energy and $t_{1,2}$ are the virtualities of the colliding pomerons. Upon
calculating the coefficient the cross-section is found to be of the order 2.2
mb at $\sqrt{s}= 6$ TeV and $\sqrt{-t_{1}}\sim\sqrt{-t_{2}}\sim 1$ GeV/c.
| [
{
"created": "Wed, 12 Jun 1996 11:36:43 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Armesto",
"N.",
""
],
[
"Braun",
"M. A.",
""
]
] | The pomeron-pomeron interaction is studied in the perturbative approach of BFKL-Bartels. The total pomeron-pomeron cross-section is proportional to $\alpha_{s}^{4}s^{\Delta}/\sqrt {t_{1}t_{2}}$ where $\sqrt{s}$ is the c.m. energy and $t_{1,2}$ are the virtualities of the colliding pomerons. Upon calculating the coefficient the cross-section is found to be of the order 2.2 mb at $\sqrt{s}= 6$ TeV and $\sqrt{-t_{1}}\sim\sqrt{-t_{2}}\sim 1$ GeV/c. |
0705.1953 | Jordan Skittrall | Ben C. Allanach, Jordan P. Skittrall, K. Sridhar | Z boson decay to photon plus Kaluza-Klein graviton in large extra
dimensions | 47 pages, uses feynmp for diagrams. v2: typographical corrections for
letter-sized paper and to correct feynmf parsing error. v3: minor error in
polarisation averaging and reference corrected. v4: reflects changes for
published version; arithmetic error corrected and reference updated; section
on transversality conditions not present in published version retained | JHEP 0711:089,2007 | 10.1088/1126-6708/2007/11/089 | DAMTP-2007-42, TIFR/TH/07-08 | hep-ph | null | In the large extra dimensional ADD scenario, Z bosons undergo a one-loop
decay into a photon and Kaluza-Klein towers of gravitons/gravi-scalars. We
calculate such a decay width, extending previous arguments about the general
form of the four-dimensional on-shell amplitude. The amplitudes calculated are
relevant to processes in other extra dimensional models where the Standard
Model fields are confined to a 4-brane.
| [
{
"created": "Mon, 14 May 2007 16:49:17 GMT",
"version": "v1"
},
{
"created": "Tue, 22 May 2007 23:35:15 GMT",
"version": "v2"
},
{
"created": "Mon, 23 Jul 2007 15:46:15 GMT",
"version": "v3"
},
{
"created": "Fri, 18 Jan 2008 11:56:18 GMT",
"version": "v4"
}
] | 2009-01-06 | [
[
"Allanach",
"Ben C.",
""
],
[
"Skittrall",
"Jordan P.",
""
],
[
"Sridhar",
"K.",
""
]
] | In the large extra dimensional ADD scenario, Z bosons undergo a one-loop decay into a photon and Kaluza-Klein towers of gravitons/gravi-scalars. We calculate such a decay width, extending previous arguments about the general form of the four-dimensional on-shell amplitude. The amplitudes calculated are relevant to processes in other extra dimensional models where the Standard Model fields are confined to a 4-brane. |
hep-ph/9601294 | Thomas Weigl | T.Weigl and W.Melnitchouk | Next-To-Leading Order Analysis of Polarized and Unpolarized Structure
Functions | 37 pages RevTeX, 7 figures, accepted for publication in Nucl. Phys. B | Nucl.Phys. B465 (1996) 267-294 | 10.1016/0550-3213(96)00015-6 | TUM/T39-95-9 | hep-ph | null | We present numerical solutions of the $Q^2$ evolution equations at
next-to-leading order (NLO) for unpolarized and polarized parton distributions,
in both the flavor non-singlet and singlet channels. The numerical method is
based on a contour integration algorithm in complex-moment space, and, unlike
most standard fitting techniques, is not restricted to the use of analytic
moments of distributions. We also compute analytic continuations of the
recently calculated singlet anomalous dimensions, needed for evolving polarized
quark and gluon distributions at NLO. Using these we study the NLO effects on
the $x$ dependence of the spin-dependent structure functions $g_1^p$ and
$g_1^n$.
| [
{
"created": "Thu, 18 Jan 1996 18:24:43 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Weigl",
"T.",
""
],
[
"Melnitchouk",
"W.",
""
]
] | We present numerical solutions of the $Q^2$ evolution equations at next-to-leading order (NLO) for unpolarized and polarized parton distributions, in both the flavor non-singlet and singlet channels. The numerical method is based on a contour integration algorithm in complex-moment space, and, unlike most standard fitting techniques, is not restricted to the use of analytic moments of distributions. We also compute analytic continuations of the recently calculated singlet anomalous dimensions, needed for evolving polarized quark and gluon distributions at NLO. Using these we study the NLO effects on the $x$ dependence of the spin-dependent structure functions $g_1^p$ and $g_1^n$. |
hep-ph/9304227 | Ivan | Eric Braaten | Tau Polarimetry with Inclusive Decays | LateX, 11 pages, no figures, NUHEP-TH-93-5 | Phys.Rev.Lett. 71 (1993) 1316-1319 | 10.1103/PhysRevLett.71.1316 | null | hep-ph | null | The spin asymmetry parameter $A_\tau$ characterizing the angular distribution
of the total hadron momentum in the decay of a polarized tau can be calculated
rigorously using perturbative QCD and the operator product expansion.
Perturbative QCD corrections to the free quark result $A_\tau = 1/3$ can be
expressed as a power series in $\alpha_s(M_\tau)$ and nonperturbative QCD
corrections can be expanded systematically in powers of $1/M_\tau^2$. The QCD
prediction is $A_\tau = 0.41 \pm 0.02$. In the decay of a high energy tau into
hadrons, the value of the hadronic energy distribution $dR_\tau/dz$ evaluated
at the maximum hadronic energy fraction $z = 1$ can also be calculated
rigorously from QCD.
| [
{
"created": "Wed, 7 Apr 1993 16:16:35 GMT",
"version": "v1"
}
] | 2009-10-22 | [
[
"Braaten",
"Eric",
""
]
] | The spin asymmetry parameter $A_\tau$ characterizing the angular distribution of the total hadron momentum in the decay of a polarized tau can be calculated rigorously using perturbative QCD and the operator product expansion. Perturbative QCD corrections to the free quark result $A_\tau = 1/3$ can be expressed as a power series in $\alpha_s(M_\tau)$ and nonperturbative QCD corrections can be expanded systematically in powers of $1/M_\tau^2$. The QCD prediction is $A_\tau = 0.41 \pm 0.02$. In the decay of a high energy tau into hadrons, the value of the hadronic energy distribution $dR_\tau/dz$ evaluated at the maximum hadronic energy fraction $z = 1$ can also be calculated rigorously from QCD. |
hep-ph/9608365 | Matthias Jamin | A. J. Buras, M. Jamin, M. E. Lautenbacher | A 1996 Analysis of the CP Violating Ratio epsilon'/epsilon | 14 pages, LaTeX, 3 figures included | Phys.Lett.B389:749-756,1996 | 10.1016/S0370-2693(96)01349-4 | MPI-Ph/96-57, TUM-T31-94/96, HD-THEP-96-23 | hep-ph | null | We update our 1993 analysis of the CP violating ratio $\epe$ in view of the
changes in several input parameters, in particular the improved value of the
top quark mass. We also investigate the strange quark mass $m_s$ dependence of
$\epe$ in view of rather low values found in the most recent lattice
calculations. A simple scanning of the input parameters within one standard
deviation gives the ranges: $-1.2 \cdot 10^{-4} \le \epe \le 16.0 \cdot
10^{-4}$ and $0 \le \epe \le 43.0 \cdot 10^{-4}$ for $\ms(\mc)=150\pm20~ \mev$
and $\ms(\mc)=100\pm20~ \mev$ respectively. If the experimentally measured
numbers and the theoretical input parameters are used with Gaussian errors, we
find $\epe= ( 3.6\pm 3.4) \cdot 10^{-4}$ and $\epe= ( 10.4\pm 8.3) \cdot
10^{-4}$ respectively. We also give results for ${\rm Im} V_{ts}^*V_{td}$.
Analyzing the dependence of $\epe$ on various parameters we find that only for
$\ms(\mc)\le 100\,\mev$ and a conspiration of other input parameters, values
for $\epe$ as large as $(2-4) \cdot 10^{-3}$ and consistent with the NA31
result can be obtained.
| [
{
"created": "Mon, 19 Aug 1996 14:42:58 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"Buras",
"A. J.",
""
],
[
"Jamin",
"M.",
""
],
[
"Lautenbacher",
"M. E.",
""
]
] | We update our 1993 analysis of the CP violating ratio $\epe$ in view of the changes in several input parameters, in particular the improved value of the top quark mass. We also investigate the strange quark mass $m_s$ dependence of $\epe$ in view of rather low values found in the most recent lattice calculations. A simple scanning of the input parameters within one standard deviation gives the ranges: $-1.2 \cdot 10^{-4} \le \epe \le 16.0 \cdot 10^{-4}$ and $0 \le \epe \le 43.0 \cdot 10^{-4}$ for $\ms(\mc)=150\pm20~ \mev$ and $\ms(\mc)=100\pm20~ \mev$ respectively. If the experimentally measured numbers and the theoretical input parameters are used with Gaussian errors, we find $\epe= ( 3.6\pm 3.4) \cdot 10^{-4}$ and $\epe= ( 10.4\pm 8.3) \cdot 10^{-4}$ respectively. We also give results for ${\rm Im} V_{ts}^*V_{td}$. Analyzing the dependence of $\epe$ on various parameters we find that only for $\ms(\mc)\le 100\,\mev$ and a conspiration of other input parameters, values for $\epe$ as large as $(2-4) \cdot 10^{-3}$ and consistent with the NA31 result can be obtained. |
hep-ph/0109165 | Wolfgang Lucha | Wolfgang Lucha and F. F. Schoberl | Instantaneous Bethe-Salpeter equation: improved analytical solution | 7 pages | Int.J.Mod.Phys. A17 (2002) 2233 | 10.1142/S0217751X0200976X | HEPHY-PUB 745/01 | hep-ph nucl-th quant-ph | null | Studying the Bethe-Salpeter formalism for interactions instantaneous in the
rest frame of the bound states described, we show that, for bound-state
constituents of arbitrary masses, the mass of the ground state of a given spin
may be calculated almost entirely analytically with high accuracy, without the
(numerical) diagonalization of the matrix representation obtained by expansion
of the solutions over a suitable set of basis states.
| [
{
"created": "Wed, 19 Sep 2001 11:11:18 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Lucha",
"Wolfgang",
""
],
[
"Schoberl",
"F. F.",
""
]
] | Studying the Bethe-Salpeter formalism for interactions instantaneous in the rest frame of the bound states described, we show that, for bound-state constituents of arbitrary masses, the mass of the ground state of a given spin may be calculated almost entirely analytically with high accuracy, without the (numerical) diagonalization of the matrix representation obtained by expansion of the solutions over a suitable set of basis states. |
1505.04084 | Simone Marzani | Gionata Luisoni, Simone Marzani | QCD resummation for hadronic final states | Topical Review, 54 pages, 11 figures. Fixed Equation (60) | J. Phys. G: Nucl. Part. Phys. 42 (2015) 103101 | 10.1088/0954-3899/42/10/103101 | MIT-CTP 4672, MPP-2015-102 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We review the basic concepts of all-order calculations in Quantum
Chromodynamics (QCD) and their application to collider phenomenology. We start
by discussing the factorization properties of QCD amplitudes and cross-sections
in the soft and collinear limits and their resulting all-order exponentiation.
We then discuss several applications of this formalism to observables which are
of great interest at particle colliders. In this context, we describe the
all-order resummation of event-shape distributions, as well as observables that
probe the internal structure of hadronic jets.
| [
{
"created": "Fri, 15 May 2015 15:00:40 GMT",
"version": "v1"
},
{
"created": "Wed, 19 Aug 2015 15:12:21 GMT",
"version": "v2"
},
{
"created": "Tue, 10 Oct 2017 12:48:26 GMT",
"version": "v3"
}
] | 2017-10-11 | [
[
"Luisoni",
"Gionata",
""
],
[
"Marzani",
"Simone",
""
]
] | We review the basic concepts of all-order calculations in Quantum Chromodynamics (QCD) and their application to collider phenomenology. We start by discussing the factorization properties of QCD amplitudes and cross-sections in the soft and collinear limits and their resulting all-order exponentiation. We then discuss several applications of this formalism to observables which are of great interest at particle colliders. In this context, we describe the all-order resummation of event-shape distributions, as well as observables that probe the internal structure of hadronic jets. |
0803.2847 | Piotr Kotko | Piotr Kotko and Michal Praszalowicz | Pion-to-photon transition distribution amplitudes in the non-local
chiral quark model | 29 pages, 8 figures. Version published in Acta Physica Polonica B.
Section devoted to semi-local model was erased | Acta Phys.Polon.B40:123-152,2009 | null | TPJU-02/2008 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We apply the non-local chiral quark model to study vector and axial
pion-to-photon transition amplitudes that are needed as a nonperturbative input
to estimate the cross section of pion annihilation into the real and virtual
photon. We use a simple form of the non-locality that allows to perform all
calculations in the Minkowski space and guaranties polynomiality of the TDA's.
We note only residual dependence on the precise form of the cut-off function,
however vector TDA that is symmetric in skewedness parameter in the local quark
model is no longer symmetric in the non-local case. We calculate also the
transition form-factors and compare them with existing experimental
parametrizations.
| [
{
"created": "Wed, 19 Mar 2008 17:17:40 GMT",
"version": "v1"
},
{
"created": "Wed, 19 Mar 2008 20:12:06 GMT",
"version": "v2"
},
{
"created": "Sun, 30 Mar 2008 20:55:46 GMT",
"version": "v3"
},
{
"created": "Fri, 30 Jan 2009 14:52:34 GMT",
"version": "v4"
}
] | 2009-07-22 | [
[
"Kotko",
"Piotr",
""
],
[
"Praszalowicz",
"Michal",
""
]
] | We apply the non-local chiral quark model to study vector and axial pion-to-photon transition amplitudes that are needed as a nonperturbative input to estimate the cross section of pion annihilation into the real and virtual photon. We use a simple form of the non-locality that allows to perform all calculations in the Minkowski space and guaranties polynomiality of the TDA's. We note only residual dependence on the precise form of the cut-off function, however vector TDA that is symmetric in skewedness parameter in the local quark model is no longer symmetric in the non-local case. We calculate also the transition form-factors and compare them with existing experimental parametrizations. |
hep-ph/9802332 | Rachel Jeannerot | R. Jeannerot (CTP, University of Sussex, UK) | Inflation and B-L breaking scale | 3 pages; to be published in the Proceedings of COSMO-97,
International Workshop on "Particle Physics and the Early Universe", 15-19
September 1997, Ambleside, Lake district, England | null | 10.1142/9789814447263_0047 | SUSX-TH-97-018 | hep-ph | null | Inflation arises in supersymmetric grand unified theories (susy GUTs) without
fine tuning and cosmic strings usually form at the end of inflation. Hence both
strings and inflation contribute to the density perturbations in the very early
universe which lead to structure formation and to CMB anisotropies. This may
give us a hint as to the $B-L$ breaking scale.
| [
{
"created": "Mon, 16 Feb 1998 18:03:08 GMT",
"version": "v1"
}
] | 2016-10-26 | [
[
"Jeannerot",
"R.",
"",
"CTP, University of Sussex, UK"
]
] | Inflation arises in supersymmetric grand unified theories (susy GUTs) without fine tuning and cosmic strings usually form at the end of inflation. Hence both strings and inflation contribute to the density perturbations in the very early universe which lead to structure formation and to CMB anisotropies. This may give us a hint as to the $B-L$ breaking scale. |
2008.03746 | Masato Arai | Masato Arai and Nobuchika Okada | Higgs-Portal Dark Matter in Nonlinear MSSM | 15 pages, 3 figures. v2: references added, version accepted for
publication in PRD | Phys. Rev. D 103, 015027 (2021) | 10.1103/PhysRevD.103.015027 | YGHP-20-04 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Supersymmetric (SUSY) extension of the Standard Model (SM) is a primary
candidate for new physics beyond the SM. If SUSY breaking scale is very low,
for example, the multi-TeV range, and the SUSY breaking sector, except for the
goldstino (gravitino), is decoupled from the low energy spectrum, the hidden
sector effect in the minimal SUSY SM (MSSM) is well described by employing the
goldstino chiral superfield ($X$) with the nilpotent condition of $X^2=0$.
Although this so-called "nonlinear MSSM" (NL-MSSM) provides a variety of
interesting phenomenologies, there is a cosmological problem that the lightest
superpartner gravitino is too light to be the major component of the dark
matter (DM) in our universe. To solve this problem, we propose a minimal
extension of the NL-MSSM by introducing a parity-odd SM singlet chiral
superfield ($\Phi$). We show that the interaction of the scalar component in
$\Phi$ with the MSSM Higgs doublets is induced after eliminating F-component of
the goldstino superfield and the lightest real scalar in $\Phi$ plays the role
of the Higgs-portal DM. With a suitable choice of the model parameters, a
successful Higgs-portal DM scenario can be realized while achieving the SM-like
Higgs boson mass of 125 GeV from the tree-level Higgs potential through the
multi-TeV SUSY breaking effect.
| [
{
"created": "Sun, 9 Aug 2020 15:30:04 GMT",
"version": "v1"
},
{
"created": "Tue, 12 Jan 2021 02:45:56 GMT",
"version": "v2"
}
] | 2021-02-03 | [
[
"Arai",
"Masato",
""
],
[
"Okada",
"Nobuchika",
""
]
] | Supersymmetric (SUSY) extension of the Standard Model (SM) is a primary candidate for new physics beyond the SM. If SUSY breaking scale is very low, for example, the multi-TeV range, and the SUSY breaking sector, except for the goldstino (gravitino), is decoupled from the low energy spectrum, the hidden sector effect in the minimal SUSY SM (MSSM) is well described by employing the goldstino chiral superfield ($X$) with the nilpotent condition of $X^2=0$. Although this so-called "nonlinear MSSM" (NL-MSSM) provides a variety of interesting phenomenologies, there is a cosmological problem that the lightest superpartner gravitino is too light to be the major component of the dark matter (DM) in our universe. To solve this problem, we propose a minimal extension of the NL-MSSM by introducing a parity-odd SM singlet chiral superfield ($\Phi$). We show that the interaction of the scalar component in $\Phi$ with the MSSM Higgs doublets is induced after eliminating F-component of the goldstino superfield and the lightest real scalar in $\Phi$ plays the role of the Higgs-portal DM. With a suitable choice of the model parameters, a successful Higgs-portal DM scenario can be realized while achieving the SM-like Higgs boson mass of 125 GeV from the tree-level Higgs potential through the multi-TeV SUSY breaking effect. |
hep-ph/9510294 | A. Khodjamirian | A. Khodjamirian and R. R\"uckl | B Meson Form Factors and Exclusive Decays | 14 pages, Latex, epsf.sty, 3 uuencoded .ps figures; invited talk
presented by R. R\"uckl at the Workshop `Beauty 95', Oxford, July 9-14,1995,
to appear in the proceedings | Nucl.Instrum.Meth. A368 (1995) 28-35 | 10.1016/0168-9002(95)00999-X | MPI-PhT/95-97, LMU 18/95 | hep-ph | null | We present results for the $B \rightarrow \pi$ and $D\rightarrow \pi$ form
factors derived from QCD sum rules on the light-cone. Our predictions are
compared with experiment and used to extract the quark mixing parameter
$|V_{ub}|$ from a recent CLEO measurement of $B \ra \pi l^+ \nu$. Furthermore,
we discuss the factorization approximation for exclusive nonleptonic matrix
elements, and describe a first QCD estimate of the nonfactorizable contribution
to the amplitude of $B \rightarrow J/\psi K $.
| [
{
"created": "Sat, 14 Oct 1995 20:10:29 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Khodjamirian",
"A.",
""
],
[
"Rückl",
"R.",
""
]
] | We present results for the $B \rightarrow \pi$ and $D\rightarrow \pi$ form factors derived from QCD sum rules on the light-cone. Our predictions are compared with experiment and used to extract the quark mixing parameter $|V_{ub}|$ from a recent CLEO measurement of $B \ra \pi l^+ \nu$. Furthermore, we discuss the factorization approximation for exclusive nonleptonic matrix elements, and describe a first QCD estimate of the nonfactorizable contribution to the amplitude of $B \rightarrow J/\psi K $. |
1612.05219 | Avital Dery | Avital Dery and Yosef Nir | FN-2HDM: Two Higgs Doublet Models with Froggatt-Nielsen Symmetry | null | null | 10.1007/JHEP04(2017)003 | null | hep-ph | http://creativecommons.org/licenses/by-nc-sa/4.0/ | We embed Two Higgs Doublet Models (2HDMs) in the Froggatt Nielsen (FN)
framework. We find that the approximate FN symmetry predicts i) approximate
Natural Flavor Conservation (NFC) of Types II or IV in the Yukawa sector, and
ii) approximate Peccei-Quinn (PQ) symmetry in the scalar sector. We discuss the
phenomenological consequences of these features.
| [
{
"created": "Thu, 15 Dec 2016 20:13:19 GMT",
"version": "v1"
}
] | 2017-04-26 | [
[
"Dery",
"Avital",
""
],
[
"Nir",
"Yosef",
""
]
] | We embed Two Higgs Doublet Models (2HDMs) in the Froggatt Nielsen (FN) framework. We find that the approximate FN symmetry predicts i) approximate Natural Flavor Conservation (NFC) of Types II or IV in the Yukawa sector, and ii) approximate Peccei-Quinn (PQ) symmetry in the scalar sector. We discuss the phenomenological consequences of these features. |
1311.1175 | Roberto Trinchero | R. Carcasses Quevedo, J. L. Goity and R. Trinchero | QCD condensates and holographic Wilson loops for asymptotically AdS
spaces | 11 pages, 1 figure | null | 10.1103/PhysRevD.89.036004 | JLAB-THY-13-1819 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The minimization of the Nambu-Goto action for a surface whose contour defines
a circular Wilson loop of radius a placed at a finite value of the coordinate
orthogonal to the boundary is considered. This is done for asymptotically AdS
spaces. The condensates of even dimension $n=2$ through $10$ are calculated in
terms of the coefficient of $a^{n}$ in the expansion of the on-shell subtracted
Nambu-Goto action for small $a$
The subtraction employed is such that it presents no conflict with conformal
invariance in the AdS case and need not introduce an additional infrared scale
for the case of confining geometries. It is shown that the UV value of the
condensates is universal in the sense that they only depends on the first
coefficients of the difference with the AdS case.
| [
{
"created": "Tue, 5 Nov 2013 19:49:08 GMT",
"version": "v1"
}
] | 2018-04-24 | [
[
"Quevedo",
"R. Carcasses",
""
],
[
"Goity",
"J. L.",
""
],
[
"Trinchero",
"R.",
""
]
] | The minimization of the Nambu-Goto action for a surface whose contour defines a circular Wilson loop of radius a placed at a finite value of the coordinate orthogonal to the boundary is considered. This is done for asymptotically AdS spaces. The condensates of even dimension $n=2$ through $10$ are calculated in terms of the coefficient of $a^{n}$ in the expansion of the on-shell subtracted Nambu-Goto action for small $a$ The subtraction employed is such that it presents no conflict with conformal invariance in the AdS case and need not introduce an additional infrared scale for the case of confining geometries. It is shown that the UV value of the condensates is universal in the sense that they only depends on the first coefficients of the difference with the AdS case. |
hep-ph/0504107 | Ramazan Sever | Sameer M. Ikhdair | On the B_{c} leptonic decay constant | 26 pages | null | null | null | hep-ph | null | We give a review and present a comprehensive calculations for the leptonic
constant B_{c} of the low-lying pseudoscalar and vector states of B_{c}-meson
in the framework of static and QCD-motivated nonrelativistic potential models
taking into account the one-loop and two-loop QCD corrections in the short
distance coefficient that governs the leptonic constant of B_{c} quarkonium
system. Further, we use the scaling relation to predict the leptonic constant
of the nS-states of the $\bar{b%}c$ system. Our results are compared with other
models to gauge the reliability of the predictions and point out differences.
| [
{
"created": "Thu, 14 Apr 2005 08:16:30 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Ikhdair",
"Sameer M.",
""
]
] | We give a review and present a comprehensive calculations for the leptonic constant B_{c} of the low-lying pseudoscalar and vector states of B_{c}-meson in the framework of static and QCD-motivated nonrelativistic potential models taking into account the one-loop and two-loop QCD corrections in the short distance coefficient that governs the leptonic constant of B_{c} quarkonium system. Further, we use the scaling relation to predict the leptonic constant of the nS-states of the $\bar{b%}c$ system. Our results are compared with other models to gauge the reliability of the predictions and point out differences. |
0808.1104 | Michael Klasen | B. Fuks (Freiburg U.), B. Herrmann (LPSC Grenoble), M. Klasen (LPSC
Grenoble) | Flavour Violation in Gauge-Mediated Supersymmetry Breaking Models:
Experimental Constraints and Phenomenology at the LHC | 29 pages, 1 table, 27 figures. Minor changes. Version published in
Nucl. Phys. B | Nucl.Phys.B810:266-299,2009 | 10.1016/j.nuclphysb.2008.11.020 | FREIBURG-PHENO 08-01, LPSC 07-116 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present an extensive analysis of gauge-mediated supersymmetry breaking
models with minimal and non-minimal flavour violation. We first demonstrate
that low-energy, precision electroweak, and cosmological constraints exclude
large "collider-friendly" regions of the minimal parameter space. We then
discuss various possibilities how flavour violation, although naturally
suppressed, may still occur in gauge-mediation models. The introduction of
non-minimal flavour violation at the electroweak scale is shown to relax the
stringent experimental constraints, so that benchmark points, that are also
cosmologically viable, can be defined and their phenomenology, i.e. squark and
gaugino production cross sections with flavour violation, at the LHC can be
studied.
| [
{
"created": "Thu, 7 Aug 2008 20:00:53 GMT",
"version": "v1"
},
{
"created": "Mon, 5 Jan 2009 13:51:51 GMT",
"version": "v2"
}
] | 2009-01-14 | [
[
"Fuks",
"B.",
"",
"Freiburg U."
],
[
"Herrmann",
"B.",
"",
"LPSC Grenoble"
],
[
"Klasen",
"M.",
"",
"LPSC\n Grenoble"
]
] | We present an extensive analysis of gauge-mediated supersymmetry breaking models with minimal and non-minimal flavour violation. We first demonstrate that low-energy, precision electroweak, and cosmological constraints exclude large "collider-friendly" regions of the minimal parameter space. We then discuss various possibilities how flavour violation, although naturally suppressed, may still occur in gauge-mediation models. The introduction of non-minimal flavour violation at the electroweak scale is shown to relax the stringent experimental constraints, so that benchmark points, that are also cosmologically viable, can be defined and their phenomenology, i.e. squark and gaugino production cross sections with flavour violation, at the LHC can be studied. |
2211.05558 | Kan Chen | Kan Chen, Zi-Yang Lin, and Shi-Lin Zhu | A comparison between the $P_c$ and $P_{cs}$ systems | 10 Pages, 3 figures, and 6 Tables | null | null | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | We construct the effective potentials of the $P_c$ and $P_{cs}$ states based
on the SU(3)$_{\text{f}}$ symmetry and heavy quark symmetry. Then we perform
the coupled-channel analysis of the lowest isospin $P_c$ and $P_{cs}$ systems.
The coupled-channel effects play different roles in the $P_c$ and $P_{cs}$
systems. In the $P_c$ systems, this effect gives minor corrections to the
masses of the $P_c$ states. In the $P_{cs}$ system, the
$\Lambda_c\bar{D}_s-\Xi_c\bar{D}$ coupling will shift the mass of the
$P_{cs}(4338)$ close to the $\Xi_c\bar{D}$ threshold. The
$\Lambda_c\bar{D}^{(*)}_s-\Xi_c\bar{D}^{(*)}$ coupling will also produce extra
$P_{cs}$ states. We discuss the correspondence between the $P_c$ and $P_{cs}$
states. Our results prefer that the SU(3) partners of the observed
$P_{c}(4312)$, $P_{c}(4440)$, and $P_{c}(4457)$ in the $P_{cs}$ system have not
been found yet.
| [
{
"created": "Thu, 10 Nov 2022 13:24:10 GMT",
"version": "v1"
}
] | 2022-11-14 | [
[
"Chen",
"Kan",
""
],
[
"Lin",
"Zi-Yang",
""
],
[
"Zhu",
"Shi-Lin",
""
]
] | We construct the effective potentials of the $P_c$ and $P_{cs}$ states based on the SU(3)$_{\text{f}}$ symmetry and heavy quark symmetry. Then we perform the coupled-channel analysis of the lowest isospin $P_c$ and $P_{cs}$ systems. The coupled-channel effects play different roles in the $P_c$ and $P_{cs}$ systems. In the $P_c$ systems, this effect gives minor corrections to the masses of the $P_c$ states. In the $P_{cs}$ system, the $\Lambda_c\bar{D}_s-\Xi_c\bar{D}$ coupling will shift the mass of the $P_{cs}(4338)$ close to the $\Xi_c\bar{D}$ threshold. The $\Lambda_c\bar{D}^{(*)}_s-\Xi_c\bar{D}^{(*)}$ coupling will also produce extra $P_{cs}$ states. We discuss the correspondence between the $P_c$ and $P_{cs}$ states. Our results prefer that the SU(3) partners of the observed $P_{c}(4312)$, $P_{c}(4440)$, and $P_{c}(4457)$ in the $P_{cs}$ system have not been found yet. |
hep-ph/0702195 | Anna Stasto | Anna M. Stasto | The BFKL Pomeron in the weak and strong coupling limits and kinematical
constraints | 15 pages, 6 figures | Phys.Rev.D75:054023,2007 | 10.1103/PhysRevD.75.054023 | null | hep-ph hep-th | null | We show that a resummation model for the evolution kernel at small x creates
a bridge between the weak and strong couplings. The resummation model embodies
DGLAP and BFKL anomalous dimensions at leading logarithmic orders, as well as a
kinematical constraint on the real emission part of the kernel. In the case of
pure gluodynamics the strong coupling limit of the Pomeron intercept is
consistent with the exchange of the spin-two, colorless particle.
| [
{
"created": "Mon, 19 Feb 2007 18:29:28 GMT",
"version": "v1"
}
] | 2010-03-25 | [
[
"Stasto",
"Anna M.",
""
]
] | We show that a resummation model for the evolution kernel at small x creates a bridge between the weak and strong couplings. The resummation model embodies DGLAP and BFKL anomalous dimensions at leading logarithmic orders, as well as a kinematical constraint on the real emission part of the kernel. In the case of pure gluodynamics the strong coupling limit of the Pomeron intercept is consistent with the exchange of the spin-two, colorless particle. |
hep-ph/9506351 | Thomas G. Rizzo | Thomas G. Rizzo | Single Top Quark Production as a Probe for Anomalous Moments at Hadron
Colliders | New discussion and 10 new figures added. uuencoded postscript file | Phys.Rev. D53 (1996) 6218-6225 | 10.1103/PhysRevD.53.6218 | SLAC-PUB-95-6758 | hep-ph | null | Single production of top quarks at hadron colliders via $gW$ fusion is
examined as a probe of possible anomalous chromomagnetic and/or chromoelectric
moment type couplings between the top and gluons. We find that this channel is
far less sensitive to the existence of anomalous couplings of this kind than is
the usual production of top pairs by $gg$ or $q\bar q$ fusion. This result is
found to hold at both the Tevatron as well as the LHC although somewhat greater
sensitivity for anomalous couplings in this channel is found at the higher
energy machine.
| [
{
"created": "Fri, 16 Jun 1995 16:18:38 GMT",
"version": "v1"
},
{
"created": "Tue, 15 Aug 1995 20:28:30 GMT",
"version": "v2"
}
] | 2009-10-28 | [
[
"Rizzo",
"Thomas G.",
""
]
] | Single production of top quarks at hadron colliders via $gW$ fusion is examined as a probe of possible anomalous chromomagnetic and/or chromoelectric moment type couplings between the top and gluons. We find that this channel is far less sensitive to the existence of anomalous couplings of this kind than is the usual production of top pairs by $gg$ or $q\bar q$ fusion. This result is found to hold at both the Tevatron as well as the LHC although somewhat greater sensitivity for anomalous couplings in this channel is found at the higher energy machine. |
hep-ph/0007249 | Tomoharu Suzuki | N.Haba and Tomoharu Suzuki | Comment on ``Linking solar and long baseline terrestrial neutrino
experiments'' | null | null | null | null | hep-ph | null | We comment on ``Linking solar and long baseline terrestrial neutrino
experiments''
| [
{
"created": "Mon, 24 Jul 2000 05:46:41 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Haba",
"N.",
""
],
[
"Suzuki",
"Tomoharu",
""
]
] | We comment on ``Linking solar and long baseline terrestrial neutrino experiments'' |
0804.0255 | Jinfeng Liao | Jinfeng Liao and Edward Shuryak | Magnetic Component of Quark-Gluon Plasma is also a Liquid! | 4 pages, 4 figures. All figs updated. Important changes and new
results included in v4 | Phys.Rev.Lett.101:162302,2008 | 10.1103/PhysRevLett.101.162302 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The so called magnetic scenario recently suggested in \cite{Liao_ES_mono}
emphasizes the role of monopoles in strongly coupled quark-gluon plasma (sQGP)
near/above the deconfinement temperature, and specifically predicts that they
help reduce its viscosity by the so called "magnetic bottle" effect. Arguments
for "magnetic liquid" in 1-2$T_c$ based on lattice measurement of monopole
density were provided in \cite{Chernodub}. Here we present results for
monopole-(anti)monopole correlation functions from the same classical molecular
dynamics simulations, which are found to be in very good agreement with recent
lattice results \cite{D'Alessandro:2007su}. We show that the magnetic Coulomb
coupling does run in the direction $opposite$ to the electric one, as expected,
and it is roughly inverse of the asymptotic freedom formula for the electric
one. However, as $T$ decreases to $T_c$, the magnetic coupling never gets weak,
with the plasma parameter always large enough ($\Gamma>1$). This nicely agrees
with empirical evidences from RHIC experiments, implying that magnetic objects
cannot have large mean free path and should also form a good liquid with low
viscosity.
| [
{
"created": "Tue, 1 Apr 2008 21:47:43 GMT",
"version": "v1"
},
{
"created": "Fri, 11 Apr 2008 20:28:57 GMT",
"version": "v2"
},
{
"created": "Wed, 28 May 2008 14:29:36 GMT",
"version": "v3"
},
{
"created": "Sat, 30 Aug 2008 04:35:52 GMT",
"version": "v4"
}
] | 2008-11-26 | [
[
"Liao",
"Jinfeng",
""
],
[
"Shuryak",
"Edward",
""
]
] | The so called magnetic scenario recently suggested in \cite{Liao_ES_mono} emphasizes the role of monopoles in strongly coupled quark-gluon plasma (sQGP) near/above the deconfinement temperature, and specifically predicts that they help reduce its viscosity by the so called "magnetic bottle" effect. Arguments for "magnetic liquid" in 1-2$T_c$ based on lattice measurement of monopole density were provided in \cite{Chernodub}. Here we present results for monopole-(anti)monopole correlation functions from the same classical molecular dynamics simulations, which are found to be in very good agreement with recent lattice results \cite{D'Alessandro:2007su}. We show that the magnetic Coulomb coupling does run in the direction $opposite$ to the electric one, as expected, and it is roughly inverse of the asymptotic freedom formula for the electric one. However, as $T$ decreases to $T_c$, the magnetic coupling never gets weak, with the plasma parameter always large enough ($\Gamma>1$). This nicely agrees with empirical evidences from RHIC experiments, implying that magnetic objects cannot have large mean free path and should also form a good liquid with low viscosity. |
hep-ph/0211321 | Mikko Laine | K. Kajantie, M. Laine, K. Rummukainen, Y. Schroder | The pressure of hot QCD up to g^6 ln(1/g) | 18 pages. Small clarifications added. To appear in Phys.Rev.D | Phys.Rev. D67 (2003) 105008 | 10.1103/PhysRevD.67.105008 | null | hep-ph | null | The free energy density, or pressure, of QCD has at high temperatures an
expansion in the coupling constant g, known so far up to order g^5. We compute
here the last contribution which can be determined perturbatively, g^6 ln(1/g),
by summing together results for the 4-loop vacuum energy densities of two
different three-dimensional effective field theories. We also demonstrate that
the inclusion of the new perturbative g^6 ln(1/g) terms, once they are summed
together with the so far unknown perturbative and non-perturbative g^6 terms,
could potentially extend the applicability of the coupling constant series down
to surprisingly low temperatures.
| [
{
"created": "Wed, 20 Nov 2002 16:27:55 GMT",
"version": "v1"
},
{
"created": "Tue, 18 Mar 2003 17:10:56 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Kajantie",
"K.",
""
],
[
"Laine",
"M.",
""
],
[
"Rummukainen",
"K.",
""
],
[
"Schroder",
"Y.",
""
]
] | The free energy density, or pressure, of QCD has at high temperatures an expansion in the coupling constant g, known so far up to order g^5. We compute here the last contribution which can be determined perturbatively, g^6 ln(1/g), by summing together results for the 4-loop vacuum energy densities of two different three-dimensional effective field theories. We also demonstrate that the inclusion of the new perturbative g^6 ln(1/g) terms, once they are summed together with the so far unknown perturbative and non-perturbative g^6 terms, could potentially extend the applicability of the coupling constant series down to surprisingly low temperatures. |
1704.08280 | Robert Carcass\'es Quevedo | Alfonso Ballon-Bayona, Robert Carcasses Quevedo, Miguel S. Costa | Unity of pomerons from gauge/string duality | null | null | 10.1007/JHEP08(2017)085 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We develop a formalism where the hard and soft pomeron contributions to high
energy scattering arise as leading Regge poles of a single kernel in
holographic QCD. The kernel is obtained using effective field theory inspired
by Regge theory of a 5-d string theory. It describes the exchange of higher
spin fields in the graviton Regge trajectory that are dual to glueball states
of twist two. For a specific holographic QCD model we describe Deep Inelastic
Scattering in the Regge limit of low Bjorken x, finding good agreement with
experimental data from HERA. The observed rise of the effective pomeron
intercept, as the size of the probe decreases, is reproduced by considering the
first four pomeron trajectories. In the case of soft probes, relevant to total
cross sections, the leading hard pomeron trajectory is suppressed, such that in
this kinematical region we reproduce an intercept of 1.09 compatible with the
QCD soft pomeron data. In the spectral region of positive Maldelstam variable t
the first two pomeron trajectories are consistent with current expectations for
the glueball spectrum from lattice simulations.
| [
{
"created": "Wed, 26 Apr 2017 18:26:04 GMT",
"version": "v1"
},
{
"created": "Wed, 5 Jul 2017 11:55:00 GMT",
"version": "v2"
}
] | 2017-09-13 | [
[
"Ballon-Bayona",
"Alfonso",
""
],
[
"Quevedo",
"Robert Carcasses",
""
],
[
"Costa",
"Miguel S.",
""
]
] | We develop a formalism where the hard and soft pomeron contributions to high energy scattering arise as leading Regge poles of a single kernel in holographic QCD. The kernel is obtained using effective field theory inspired by Regge theory of a 5-d string theory. It describes the exchange of higher spin fields in the graviton Regge trajectory that are dual to glueball states of twist two. For a specific holographic QCD model we describe Deep Inelastic Scattering in the Regge limit of low Bjorken x, finding good agreement with experimental data from HERA. The observed rise of the effective pomeron intercept, as the size of the probe decreases, is reproduced by considering the first four pomeron trajectories. In the case of soft probes, relevant to total cross sections, the leading hard pomeron trajectory is suppressed, such that in this kinematical region we reproduce an intercept of 1.09 compatible with the QCD soft pomeron data. In the spectral region of positive Maldelstam variable t the first two pomeron trajectories are consistent with current expectations for the glueball spectrum from lattice simulations. |
1004.1177 | Francesco Riva Dr | Francesco Riva | Low-Scale Leptogenesis and the Domain Wall Problem in Models with
Discrete Flavor Symmetries | 18 Pages, 2 figures; References added, version for PLB | Phys.Lett.B690:443-450,2010 | 10.1016/j.physletb.2010.05.073 | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose a new mechanism for leptogenesis, which is naturally realized in
some models with a flavor symmetry based on the discrete group A_4, where the
symmetry breaking parameter also controls the Majorana masses for the heavy
right handed (RH) neutrinos. During the early universe, for T>TeV, part of the
symmetry is restored, due to finite temperature contributions, and the RH
neutrinos remain massless and can be produced in thermal equilibrium even at
temperatures well below the most conservative gravitino bounds. Below this
temperature the phase transition occurs and they become massive, decaying out
of equilibrium and producing the necessary lepton asymmetry. Unless the
symmetry is broken explicitly by Planck-suppressed terms, the domain walls
generated by the symmetry breaking survive till the quark-hadron phase
transition, where they disappear due to a small energy splitting between
different vacua caused by the QCD anomaly.
| [
{
"created": "Wed, 7 Apr 2010 20:07:53 GMT",
"version": "v1"
},
{
"created": "Fri, 21 May 2010 07:33:02 GMT",
"version": "v2"
}
] | 2014-11-20 | [
[
"Riva",
"Francesco",
""
]
] | We propose a new mechanism for leptogenesis, which is naturally realized in some models with a flavor symmetry based on the discrete group A_4, where the symmetry breaking parameter also controls the Majorana masses for the heavy right handed (RH) neutrinos. During the early universe, for T>TeV, part of the symmetry is restored, due to finite temperature contributions, and the RH neutrinos remain massless and can be produced in thermal equilibrium even at temperatures well below the most conservative gravitino bounds. Below this temperature the phase transition occurs and they become massive, decaying out of equilibrium and producing the necessary lepton asymmetry. Unless the symmetry is broken explicitly by Planck-suppressed terms, the domain walls generated by the symmetry breaking survive till the quark-hadron phase transition, where they disappear due to a small energy splitting between different vacua caused by the QCD anomaly. |
hep-ph/9609269 | Marshall Baker | M. Baker (University of Washington, Seattle) | Electric-Magnetic Duality and the Heavy Quark Potential | 13 pages 1 postscript figure uses sprocl.sty psfig.sty | null | null | null | hep-ph | null | We use the assumption of electric-magnetic duality to express the heavy quark
potential in QCD in terms of a Wilson Loop $W_{eff}(\Gamma)$ determined by the
dynamics of a dual theory which is weakly coupled at long distances. The
classical approximation gives the leading contribution to $W_{eff}(\Gamma)$ and
yields a velocity dependent heavy quark potential which for large $R$ becomes
linear in $R$, and which for small $R$ approaches lowest order perturbative
QCD. The corresponding long distance interaction between color magnetic
monopoles is governed by a Yukawa potential. As a consequence the magnetic
interaction between the color magnetic moments of the quarks is exponentially
damped. The semi-classical corrections to $W_{eff}(\Gamma)$ due to fluctuations
of the classical flux tube should lead to an effective string theory free from
the conformal anomaly.
| [
{
"created": "Thu, 5 Sep 1996 21:52:20 GMT",
"version": "v1"
}
] | 2016-09-06 | [
[
"Baker",
"M.",
"",
"University of Washington, Seattle"
]
] | We use the assumption of electric-magnetic duality to express the heavy quark potential in QCD in terms of a Wilson Loop $W_{eff}(\Gamma)$ determined by the dynamics of a dual theory which is weakly coupled at long distances. The classical approximation gives the leading contribution to $W_{eff}(\Gamma)$ and yields a velocity dependent heavy quark potential which for large $R$ becomes linear in $R$, and which for small $R$ approaches lowest order perturbative QCD. The corresponding long distance interaction between color magnetic monopoles is governed by a Yukawa potential. As a consequence the magnetic interaction between the color magnetic moments of the quarks is exponentially damped. The semi-classical corrections to $W_{eff}(\Gamma)$ due to fluctuations of the classical flux tube should lead to an effective string theory free from the conformal anomaly. |
1001.3759 | Takeshi Araki | T. Araki and C. Q. Geng | Quark Masses and Mixings with Hierarchical Friedberg-Lee Symmetry | 11 pages, 1 figure. v2: typos corrected, published version | Phys.Rev.D81:076009,2010 | 10.1103/PhysRevD.81.076009 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider the Friedberg-Lee symmetry for the quark sector and show that the
symmetry closely relates to both quark masses and mixing angles. We also extend
our scheme to the fourth generation quark model and find the relation
$|V_{tb^{'}}| \simeq |V_{t^{'}b}| \simeq m_b/m_{b^{'}}< \lambda^2$ with
$\lambda\simeq0.22$ for $m_b=4.2\ \gev$ and $m_{b^{'}}>199\ \gev$.
| [
{
"created": "Thu, 21 Jan 2010 10:28:50 GMT",
"version": "v1"
},
{
"created": "Sun, 2 May 2010 03:49:31 GMT",
"version": "v2"
}
] | 2010-05-28 | [
[
"Araki",
"T.",
""
],
[
"Geng",
"C. Q.",
""
]
] | We consider the Friedberg-Lee symmetry for the quark sector and show that the symmetry closely relates to both quark masses and mixing angles. We also extend our scheme to the fourth generation quark model and find the relation $|V_{tb^{'}}| \simeq |V_{t^{'}b}| \simeq m_b/m_{b^{'}}< \lambda^2$ with $\lambda\simeq0.22$ for $m_b=4.2\ \gev$ and $m_{b^{'}}>199\ \gev$. |
1312.5811 | Ernesto Germ\'an Delgado Acosta | E. G. Delgado-Acosta and M. Kirchbach | Second order theory of $(j,0)\oplus (0,j)$ single high spins as Lorentz
tensors | null | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We show that higher order differential equations and matrix spinor calculus
are completely avoidable in the description of pure high spin-$j$ Weinberg-Joos
states, $(j,0)\oplus (0,j)$. The case is made on the example of
$(3/2,0)\oplus(0,3/2)$, for the sake of concreteness and without loss of
generality. Namely, we use as a vehicle for the aforementioned covariant single
spin-$3/2$ description the antisymmetric tensor of second rank with Dirac
spinor components, $\Psi_{[\mu\nu]}=B_{[\mu\nu]}\otimes\psi$. The
$(3/2,0)\oplus(0,3/2)$ sector of interest is tracked down in two steps. First
we search for spin-$3/2$ by means of a covariant spin projector constructed
from the Casimir invariants of the Poincar\'e algebra, and then we identify the
wanted irreducible representation space by means of a momentum independent
(static) projector designed on the basis of the Casimir invariants of the
Lorentz algebra. The latter projectors unambiguously identify any irreducible
$so(1,3)$ subspace of any Lorentz tensor and without rising the order of the
differential equation. The method proposed correctly reproduces the
electromagnetic multipole moments earlier calculated for single spin-$3/2$
particles in treating it in the standard way as eight dimensional spinor. We
furthermore calculate Compton scattering off the pure spin-$3/2$ under
discussion, and show that the differential cross section satisfies unitarity in
forward direction for a gyromagnetic ratio of $g=2/3$. Suggesting possible
validity of Belinfante's conjecture for pure spin-states, while the natural
value of $g=2$ seems more likely to characterize the highest spins in the
Rarita-Schwinger representation spaces. The scheme straightforwardly extends to
any $(j,0)\oplus (0,j)$ Weinberg-Joos state and brings the advantage of
avoiding rectangular matrix couplings between states of different spins,
replacing them by simple Lorentz contractions.
| [
{
"created": "Fri, 20 Dec 2013 05:13:20 GMT",
"version": "v1"
}
] | 2013-12-23 | [
[
"Delgado-Acosta",
"E. G.",
""
],
[
"Kirchbach",
"M.",
""
]
] | We show that higher order differential equations and matrix spinor calculus are completely avoidable in the description of pure high spin-$j$ Weinberg-Joos states, $(j,0)\oplus (0,j)$. The case is made on the example of $(3/2,0)\oplus(0,3/2)$, for the sake of concreteness and without loss of generality. Namely, we use as a vehicle for the aforementioned covariant single spin-$3/2$ description the antisymmetric tensor of second rank with Dirac spinor components, $\Psi_{[\mu\nu]}=B_{[\mu\nu]}\otimes\psi$. The $(3/2,0)\oplus(0,3/2)$ sector of interest is tracked down in two steps. First we search for spin-$3/2$ by means of a covariant spin projector constructed from the Casimir invariants of the Poincar\'e algebra, and then we identify the wanted irreducible representation space by means of a momentum independent (static) projector designed on the basis of the Casimir invariants of the Lorentz algebra. The latter projectors unambiguously identify any irreducible $so(1,3)$ subspace of any Lorentz tensor and without rising the order of the differential equation. The method proposed correctly reproduces the electromagnetic multipole moments earlier calculated for single spin-$3/2$ particles in treating it in the standard way as eight dimensional spinor. We furthermore calculate Compton scattering off the pure spin-$3/2$ under discussion, and show that the differential cross section satisfies unitarity in forward direction for a gyromagnetic ratio of $g=2/3$. Suggesting possible validity of Belinfante's conjecture for pure spin-states, while the natural value of $g=2$ seems more likely to characterize the highest spins in the Rarita-Schwinger representation spaces. The scheme straightforwardly extends to any $(j,0)\oplus (0,j)$ Weinberg-Joos state and brings the advantage of avoiding rectangular matrix couplings between states of different spins, replacing them by simple Lorentz contractions. |
1012.1811 | Oliver Fochler | Oliver Fochler, Zhe Xu and Carsten Greiner | Jets and flow within a pQCD-based partonic transport model | 4 pages, 2 figures, Proceedings of Hard Probes 2010 | Nucl.Phys.A855:420-423,2011 | 10.1016/j.nuclphysa.2011.02.095 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present fully dynamic simulations of heavy ion collisions at RHIC energies
within the perturbative QCD-based partonic transport model BAMPS, focusing on
the simultaneous investigation of jet-quenching and elliptic flow. The model
consistently features elastic and inelastic 2 -> 3 processes, the latter being
based on the Gunion-Bertsch matrix element. We discuss first attempts to extend
the model to include light quark degrees of freedom and study the energy loss
of high energy gluons and quarks in a static partonic medium. The difference
between gluons and quarks in inelastic processes is found to be weaker than
expected from color factors, due to a self-quenching effect associated with a
cut-off modeling the LPM effect.
| [
{
"created": "Wed, 8 Dec 2010 17:08:15 GMT",
"version": "v1"
}
] | 2011-10-06 | [
[
"Fochler",
"Oliver",
""
],
[
"Xu",
"Zhe",
""
],
[
"Greiner",
"Carsten",
""
]
] | We present fully dynamic simulations of heavy ion collisions at RHIC energies within the perturbative QCD-based partonic transport model BAMPS, focusing on the simultaneous investigation of jet-quenching and elliptic flow. The model consistently features elastic and inelastic 2 -> 3 processes, the latter being based on the Gunion-Bertsch matrix element. We discuss first attempts to extend the model to include light quark degrees of freedom and study the energy loss of high energy gluons and quarks in a static partonic medium. The difference between gluons and quarks in inelastic processes is found to be weaker than expected from color factors, due to a self-quenching effect associated with a cut-off modeling the LPM effect. |
hep-ph/0011280 | Peter Kroll | P. Kroll (Wuppertal Univ.) | Skewed parton distributions and wide-angle exclusive scattering | 10 pages, 6 figures (using LATEX with epsfig), talked presented at
ISHEPP XV: Relativistic nuclear physics and Quantum Chromodynamics, Dubna,
September 2000 | null | null | WU-B 00-20 | hep-ph | null | The overlap representation of skewed parton distributions is discussed and
applications to wide-angle Compton scattering and electroproduction of mesons
are presented. The amplitudes for these processes factorise into parton-level
subprocess amplitudes and form factors representing 1/x-moments of skewed
parton distributions.
| [
{
"created": "Wed, 22 Nov 2000 11:06:12 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Kroll",
"P.",
"",
"Wuppertal Univ."
]
] | The overlap representation of skewed parton distributions is discussed and applications to wide-angle Compton scattering and electroproduction of mesons are presented. The amplitudes for these processes factorise into parton-level subprocess amplitudes and form factors representing 1/x-moments of skewed parton distributions. |
1812.04113 | Urs Wiedemann A | Boris Blok and Urs Achim Wiedemann | Collectivity in pp from resummed interference effects? | 8 pages, 1 Fig | null | 10.1016/j.physletb.2019.05.038 | CERN-TH-2018-270 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Azimuthal asymmetries $v_n$ in the soft transverse momentum spectra of
hadronic collisions can result as a consequence of quantum interference and
color flow which translates spatial anisotropies into momentum anisotropies via
multipole radiation patterns. Here, we analyze to what extent these effects
result in signal strengths $v_n\lbrace 2s\rbrace$ that can persist in higher
order $(2s)$ cumulants. In a simple model of soft multi-particle production
with quantum interference effects in which $m$ particles are emitted from $N$
sources and in which interference contributions appear naturally ordered in
inverse powers of the adjoint color trace, $1/(N_c^2-1)$, we provide the first
resummed calculation of all powers of $m^2/(N_c^2-1)$. This allows one to
determine all higher order flow cumulants $v_n\lbrace 2s\rbrace$ with the same
parametric accuracy. For a phenomenologically relevant range of $N$ sources
emitting $m$ particles, we find that the even flow coefficients $v_n\lbrace
2s\rbrace$ decrease very mildly with increasing cumulants. This provides a
proof of principle that non-vanishing higher order cumulants $v_n\lbrace
2s\rbrace$ can persist in systems that exhibit neither final state interactions
nor phenomena related to high (saturated) initial parton densities.
| [
{
"created": "Mon, 10 Dec 2018 21:50:59 GMT",
"version": "v1"
}
] | 2019-06-05 | [
[
"Blok",
"Boris",
""
],
[
"Wiedemann",
"Urs Achim",
""
]
] | Azimuthal asymmetries $v_n$ in the soft transverse momentum spectra of hadronic collisions can result as a consequence of quantum interference and color flow which translates spatial anisotropies into momentum anisotropies via multipole radiation patterns. Here, we analyze to what extent these effects result in signal strengths $v_n\lbrace 2s\rbrace$ that can persist in higher order $(2s)$ cumulants. In a simple model of soft multi-particle production with quantum interference effects in which $m$ particles are emitted from $N$ sources and in which interference contributions appear naturally ordered in inverse powers of the adjoint color trace, $1/(N_c^2-1)$, we provide the first resummed calculation of all powers of $m^2/(N_c^2-1)$. This allows one to determine all higher order flow cumulants $v_n\lbrace 2s\rbrace$ with the same parametric accuracy. For a phenomenologically relevant range of $N$ sources emitting $m$ particles, we find that the even flow coefficients $v_n\lbrace 2s\rbrace$ decrease very mildly with increasing cumulants. This provides a proof of principle that non-vanishing higher order cumulants $v_n\lbrace 2s\rbrace$ can persist in systems that exhibit neither final state interactions nor phenomena related to high (saturated) initial parton densities. |
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