id stringlengths 9 14 | submitter stringlengths 1 56 ⌀ | authors stringlengths 5 7.68k | title stringlengths 3 299 | comments stringlengths 1 1.15k ⌀ | journal-ref stringlengths 9 298 ⌀ | doi stringlengths 12 97 ⌀ | report-no stringlengths 3 341 ⌀ | categories stringclasses 869 values | license stringclasses 9 values | orig_abstract stringlengths 16 2.44k | versions listlengths 1 39 | update_date stringlengths 10 10 | authors_parsed listlengths 1 565 | abstract stringlengths 13 2.44k |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1302.4511 | Chen Gang | Chen Zheng-Yu, Wang Mei-Juan, Xie Yi-Long, Liang Zhu and Chen Gang | Study on the Energy Dependence of the Radii of Jets by the HBT
Correlation Method in e+e- collisions | 10 pages, 5 figures | null | 10.5506/APhysPolB.45.1089 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The energy dependence of the radii size of jets are studied in detail by the
HBT correlation method using Monte Carlo Simulation generator Jetset7.4 to
produce 40,000,000 events of e$^+$e$^-$ collisions at $\sqrt s =30$, 50, 70,
91.2, 110, 130, 150 and 170 GeV. The radii of jets are measured using the HBT
correlation method with the indistinguishability of identical final state
pions. It is found that the average radii of quark-jets and gluon-jets are
independent of the c.m. energy of e$^+$e$^-$ collisions. The average radius of
quark-jets are obviously larger than that of gluon-jets. The invariable average
radii of quark-jets and gluon-jets in e$^+$e$^-$ collisions are obtained at the
end of parton evolvement.
| [
{
"created": "Tue, 19 Feb 2013 03:54:28 GMT",
"version": "v1"
}
] | 2014-09-30 | [
[
"Zheng-Yu",
"Chen",
""
],
[
"Mei-Juan",
"Wang",
""
],
[
"Yi-Long",
"Xie",
""
],
[
"Zhu",
"Liang",
""
],
[
"Gang",
"Chen",
""
]
] | The energy dependence of the radii size of jets are studied in detail by the HBT correlation method using Monte Carlo Simulation generator Jetset7.4 to produce 40,000,000 events of e$^+$e$^-$ collisions at $\sqrt s =30$, 50, 70, 91.2, 110, 130, 150 and 170 GeV. The radii of jets are measured using the HBT correlation method with the indistinguishability of identical final state pions. It is found that the average radii of quark-jets and gluon-jets are independent of the c.m. energy of e$^+$e$^-$ collisions. The average radius of quark-jets are obviously larger than that of gluon-jets. The invariable average radii of quark-jets and gluon-jets in e$^+$e$^-$ collisions are obtained at the end of parton evolvement. |
0705.1500 | Christopher Thomas | C. E. Thomas | Composition of the Pseudoscalar Eta and Eta' Mesons | 34 pages, 11 figures. v2: version published in JHEP, added
substantial section on B and D meson electroweak decays, added comment on
psi' to eta(')/eta_c gamma, Figs 5 and 6 split and made clearer, added
references, other minor revisions which don't change conclusions | JHEP 0710:026,2007 | 10.1088/1126-6708/2007/10/026 | OUTP-07-06P | hep-ph hep-ex | null | The composition of the eta and eta' mesons has long been a source of
discussion and is of current interest with new experimental results appearing.
We investigate what can be learnt from a number of different processes: V to P
gamma and P to V gamma (V and P are light vector and pseudoscalar mesons
respectively), P to gamma gamma, J/psi,psi' to P gamma, J/psi,psi' to P V, and
chi_{c0,2} to PP. These constrain the eta-eta' mixing angle to a consistent
value, phi approx 42 degrees; we find that the c cbar components are lesssim 5%
in amplitude. We also find that, while the data hint at a small gluonic
component in the eta', the conclusions depend sensitively on unknown form
factors associated with exclusive dynamics. In addition, we predict BR(psi' to
eta' gamma) approx 1 10^{-5} and BR(chi_{c0} to eta eta') approx 2 10^{-5} - 1
10^{-4}. We provide a method to test the mixing using chi_{c2} to eta eta, eta'
eta', and eta eta' modes and make some general observations on chi_{c0,2}
decays. We also survey the semileptonic and hadronic decays of bottom and
charmed mesons and find some modes where the mixing angle can be extracted
cleanly with the current experimental data, some where more data will allow
this, and some where a more detailed knowledge of the different amplitudes is
required.
| [
{
"created": "Thu, 10 May 2007 17:03:45 GMT",
"version": "v1"
},
{
"created": "Mon, 15 Oct 2007 13:54:36 GMT",
"version": "v2"
}
] | 2009-04-22 | [
[
"Thomas",
"C. E.",
""
]
] | The composition of the eta and eta' mesons has long been a source of discussion and is of current interest with new experimental results appearing. We investigate what can be learnt from a number of different processes: V to P gamma and P to V gamma (V and P are light vector and pseudoscalar mesons respectively), P to gamma gamma, J/psi,psi' to P gamma, J/psi,psi' to P V, and chi_{c0,2} to PP. These constrain the eta-eta' mixing angle to a consistent value, phi approx 42 degrees; we find that the c cbar components are lesssim 5% in amplitude. We also find that, while the data hint at a small gluonic component in the eta', the conclusions depend sensitively on unknown form factors associated with exclusive dynamics. In addition, we predict BR(psi' to eta' gamma) approx 1 10^{-5} and BR(chi_{c0} to eta eta') approx 2 10^{-5} - 1 10^{-4}. We provide a method to test the mixing using chi_{c2} to eta eta, eta' eta', and eta eta' modes and make some general observations on chi_{c0,2} decays. We also survey the semileptonic and hadronic decays of bottom and charmed mesons and find some modes where the mixing angle can be extracted cleanly with the current experimental data, some where more data will allow this, and some where a more detailed knowledge of the different amplitudes is required. |
hep-ph/9307276 | null | Stephen P. Martin | Automatic Gauged R-Parity | 9 pages, NUB-3063-93TH | null | null | null | hep-ph | null | In the minimal supersymmetric standard model, the existence of R-parity is
not required for the internal consistency of the theory and might therefore be
regarded as ad hoc. I catalog some simple conditions which are sufficient to
guarantee that R-parity survives as an unbroken gauged discrete subgroup of the
continuous gauge symmetry in certain extensions of the minimal supersymmetric
standard model. If these criteria are met, R-parity is automatic. [Based on a
talk given at the International Workshop on Supersymmetry and Unification of
Fundamental Interactions (SUSY93) at Northeastern University, Boston, March
29-April 1 1993.]
| [
{
"created": "Thu, 15 Jul 1993 05:09:00 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Martin",
"Stephen P.",
""
]
] | In the minimal supersymmetric standard model, the existence of R-parity is not required for the internal consistency of the theory and might therefore be regarded as ad hoc. I catalog some simple conditions which are sufficient to guarantee that R-parity survives as an unbroken gauged discrete subgroup of the continuous gauge symmetry in certain extensions of the minimal supersymmetric standard model. If these criteria are met, R-parity is automatic. [Based on a talk given at the International Workshop on Supersymmetry and Unification of Fundamental Interactions (SUSY93) at Northeastern University, Boston, March 29-April 1 1993.] |
1004.0099 | Mohammed Abbas | Mohammed Abbas and A. Yu. Smirnov | Is the tri-bimaximal mixing accidental? | 40 pages, 2 eps figures. Mass matrices are recalculated according to
new global fit of oscillation data. One new table, references and comments
are added. References are added | Phys.Rev.D82:013008,2010 | 10.1103/PhysRevD.82.013008 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The Tri-bimaximal (TBM) mixing is not accidental if structures of the
corresponding leptonic mass matrices follow immediately from certain (residual
or broken) flavor symmetry. We develop a simple formalism which allows one to
analyze effects of deviations of the lepton mixing from TBM on structure of the
neutrino mass matrix and on underlying flavor symmetry. We show that possible
deviations from the TBM mixing can lead to strong modifications of the mass
matrix and strong violation of the TBM mass relations. As a result, the mass
matrix may have an "anarchical" structure with random values of elements or it
may have some symmetry which differs from the TBM symmetry. Interesting
examples include matrices with texture zeros, matrices with certain "flavor
alignment" as well as hierarchical matrices with a two-component structure,
where the dominant and sub-dominant contributions have different symmetries.
This opens up new approaches to understand the lepton mixing.
| [
{
"created": "Thu, 1 Apr 2010 10:17:23 GMT",
"version": "v1"
},
{
"created": "Mon, 10 May 2010 10:13:58 GMT",
"version": "v2"
},
{
"created": "Mon, 14 Jun 2010 16:41:18 GMT",
"version": "v3"
}
] | 2014-11-20 | [
[
"Abbas",
"Mohammed",
""
],
[
"Smirnov",
"A. Yu.",
""
]
] | The Tri-bimaximal (TBM) mixing is not accidental if structures of the corresponding leptonic mass matrices follow immediately from certain (residual or broken) flavor symmetry. We develop a simple formalism which allows one to analyze effects of deviations of the lepton mixing from TBM on structure of the neutrino mass matrix and on underlying flavor symmetry. We show that possible deviations from the TBM mixing can lead to strong modifications of the mass matrix and strong violation of the TBM mass relations. As a result, the mass matrix may have an "anarchical" structure with random values of elements or it may have some symmetry which differs from the TBM symmetry. Interesting examples include matrices with texture zeros, matrices with certain "flavor alignment" as well as hierarchical matrices with a two-component structure, where the dominant and sub-dominant contributions have different symmetries. This opens up new approaches to understand the lepton mixing. |
0903.1201 | Rohit Dhir | Rohit Dhir, R. C. Verma, Avinash Sharma | Effects of Flavor Dependence on Weak Decays of J/psi and \Upsilon | 27 pages, one figure and one sub section added, results and
references changed | Advances in High Energy Physics Volume 2013 (2013), Article ID
706543, 12 pages | 10.1155/2013/706543 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We give the detailed analysis of effects of flavor dependence of average
transverse quark momentum inside a meson on J/psi --> P and \Upsilon --> Bc
transition form factors and two-body weak hadronic decays of J/psi and \Upsilon
employing the factorization scheme. We predict the branching ratios of
semileptonic and nonleptonic weak decays of J/psi and \Upsilon mesons in
Cabibbo-angle-enhanced and Cabibbo-angle-suppressed modes.
| [
{
"created": "Fri, 6 Mar 2009 13:16:59 GMT",
"version": "v1"
},
{
"created": "Thu, 15 Dec 2011 15:39:01 GMT",
"version": "v2"
},
{
"created": "Tue, 17 Apr 2012 14:47:47 GMT",
"version": "v3"
}
] | 2013-03-01 | [
[
"Dhir",
"Rohit",
""
],
[
"Verma",
"R. C.",
""
],
[
"Sharma",
"Avinash",
""
]
] | We give the detailed analysis of effects of flavor dependence of average transverse quark momentum inside a meson on J/psi --> P and \Upsilon --> Bc transition form factors and two-body weak hadronic decays of J/psi and \Upsilon employing the factorization scheme. We predict the branching ratios of semileptonic and nonleptonic weak decays of J/psi and \Upsilon mesons in Cabibbo-angle-enhanced and Cabibbo-angle-suppressed modes. |
2008.02573 | Tanmoy Modak | Wei-Shu Hou, Ting-Hsiang Hsu and Tanmoy Modak | Constraining $t \to u$ flavor changing neutral Higgs coupling at the LHC | 6 pages, 6 figures | Phys. Rev. D 102, 055006 (2020) | 10.1103/PhysRevD.102.055006 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the constraints on $t\to u$ flavor changing neutral Higgs (FCNH)
coupling, and how it may be explored further at the Large Hadron Collider
(LHC). In the general two Higgs doublet model, such transitions can be induced
by a nonzero $\rho_{tu}$ Yukawa coupling. We show that such couplings can be
constrained by existing searches at the LHC for $m_H$, $m_A$ and, $m_{H^+}$ in
the sub-TeV range, where $H$, $A$ and $H^+$ are the exotic $CP$-even, $CP$-odd
and charged scalars. We find that a dedicated $ug\to t H/tA \to t t \bar u$
search can probe the available parameter space of $\rho_{tu}$ down to a few
percent level for $200\,\mbox{GeV} \lesssim m_H,\,m_A \lesssim 600$ GeV, with
discovery possible at high luminosity. Effects of how other extra top Yukawa
couplings, such as $\rho_{tc}$ and $\rho_{tt}$, dilute the sensitivity of the
$\rho_{tu}$ probe are discussed.
| [
{
"created": "Thu, 6 Aug 2020 11:08:33 GMT",
"version": "v1"
}
] | 2020-09-16 | [
[
"Hou",
"Wei-Shu",
""
],
[
"Hsu",
"Ting-Hsiang",
""
],
[
"Modak",
"Tanmoy",
""
]
] | We study the constraints on $t\to u$ flavor changing neutral Higgs (FCNH) coupling, and how it may be explored further at the Large Hadron Collider (LHC). In the general two Higgs doublet model, such transitions can be induced by a nonzero $\rho_{tu}$ Yukawa coupling. We show that such couplings can be constrained by existing searches at the LHC for $m_H$, $m_A$ and, $m_{H^+}$ in the sub-TeV range, where $H$, $A$ and $H^+$ are the exotic $CP$-even, $CP$-odd and charged scalars. We find that a dedicated $ug\to t H/tA \to t t \bar u$ search can probe the available parameter space of $\rho_{tu}$ down to a few percent level for $200\,\mbox{GeV} \lesssim m_H,\,m_A \lesssim 600$ GeV, with discovery possible at high luminosity. Effects of how other extra top Yukawa couplings, such as $\rho_{tc}$ and $\rho_{tt}$, dilute the sensitivity of the $\rho_{tu}$ probe are discussed. |
1202.0730 | Tord Riemann | Jochem Fleischer and Tord Riemann and Valery Yundin | New results for algebraic tensor reduction of Feynman integrals | 8 pages, 1 figure. Contribution to Proceedings of "10th International
Symposium on Radiative Corrections (Applications of Quantum Field Theory to
Phenomenology)" - Radcor2011, September 26-30, 2011, Mamallapuram, India | null | null | DESY 11-253, BI-TP 2011/52 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We report on some recent developments in algebraic tensor reduction of
one-loop Feynman integrals. For 5-point functions, an efficient tensor
reduction was worked out recently and is now available as numerical C++
package, PJFry, covering tensor ranks until five. It is free of inverse 5-point
Gram determinants, and inverse small 4-point Gram determinants are treated by
expansions in higher-dimensional 3-point functions. By exploiting sums over
signed minors, weighted with scalar products of chords (or, equivalently,
external momenta), extremely efficient expressions for tensor integrals
contracted with external momenta were derived. The evaluation of 7-point
functions is discussed. In the present approach one needs for the reductions a
$(d+2)$-dimensional scalar 5-point function in addition to the usual scalar
basis of 1- to 4-point functions in the generic dimension $d=4-2 \epsilon$.
When exploiting the four-dimensionality of the kinematics, this basis is
sufficient. We indicate how the $(d+2)$-dimensional 5-point function can be
evaluated.
| [
{
"created": "Fri, 3 Feb 2012 15:15:15 GMT",
"version": "v1"
}
] | 2012-02-06 | [
[
"Fleischer",
"Jochem",
""
],
[
"Riemann",
"Tord",
""
],
[
"Yundin",
"Valery",
""
]
] | We report on some recent developments in algebraic tensor reduction of one-loop Feynman integrals. For 5-point functions, an efficient tensor reduction was worked out recently and is now available as numerical C++ package, PJFry, covering tensor ranks until five. It is free of inverse 5-point Gram determinants, and inverse small 4-point Gram determinants are treated by expansions in higher-dimensional 3-point functions. By exploiting sums over signed minors, weighted with scalar products of chords (or, equivalently, external momenta), extremely efficient expressions for tensor integrals contracted with external momenta were derived. The evaluation of 7-point functions is discussed. In the present approach one needs for the reductions a $(d+2)$-dimensional scalar 5-point function in addition to the usual scalar basis of 1- to 4-point functions in the generic dimension $d=4-2 \epsilon$. When exploiting the four-dimensionality of the kinematics, this basis is sufficient. We indicate how the $(d+2)$-dimensional 5-point function can be evaluated. |
hep-ph/9808264 | Yi Bing Ding | Yi-Bing Ding, Xue-Qian Li, Peng-Nian Shen | Variational Estimation of the Wave Function at Origin for Heavy
Quarkonium | 17 pages, .zip file of the LATEX2E | Phys.Rev.D60:074010,1999 | 10.1103/PhysRevD.60.074010 | null | hep-ph | null | The wave function at the origin (WFO) is an important quantity in studying
many physical problems concerning heavy quarkonia. However, when one used the
variational method with fewer parameters, in general, the deviation of
resultant WFO from the "accurate" solution was not well estimated. In this
paper, we discuss this issue by employing several potential forms and trial
wave functions in detail and study the relation between WFO and the reduced
mass.
| [
{
"created": "Fri, 7 Aug 1998 16:38:33 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Ding",
"Yi-Bing",
""
],
[
"Li",
"Xue-Qian",
""
],
[
"Shen",
"Peng-Nian",
""
]
] | The wave function at the origin (WFO) is an important quantity in studying many physical problems concerning heavy quarkonia. However, when one used the variational method with fewer parameters, in general, the deviation of resultant WFO from the "accurate" solution was not well estimated. In this paper, we discuss this issue by employing several potential forms and trial wave functions in detail and study the relation between WFO and the reduced mass. |
hep-ph/0412173 | Claude Semay | F. Brau, C. Semay, B. Silvestre-Brac | Semirelativistic potential model for glueball states | 4 figures | Phys.Rev. D70 (2004) 014017 | 10.1103/PhysRevD.70.014017 | null | hep-ph | null | The masses of two-gluon glueballs are studied with a semirelativistic
potential model whose interaction is a scalar linear confinement supplemented
by a one-gluon exchange mechanism. The gluon is massless but the leading
corrections of the dominant part of the Hamiltonian are expressed in terms of a
state dependent constituent gluon mass. The Hamiltonian depends only on 3
parameters: the strong coupling constant, the string tension, and a gluon size
which removes all singularities in the leading corrections of the potential.
Accurate numerical calculations are performed with a Lagrange mesh method. The
masses predicted are in rather good agreement with lattice results and with
some experimental glueball candidates.
| [
{
"created": "Tue, 14 Dec 2004 15:56:55 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Brau",
"F.",
""
],
[
"Semay",
"C.",
""
],
[
"Silvestre-Brac",
"B.",
""
]
] | The masses of two-gluon glueballs are studied with a semirelativistic potential model whose interaction is a scalar linear confinement supplemented by a one-gluon exchange mechanism. The gluon is massless but the leading corrections of the dominant part of the Hamiltonian are expressed in terms of a state dependent constituent gluon mass. The Hamiltonian depends only on 3 parameters: the strong coupling constant, the string tension, and a gluon size which removes all singularities in the leading corrections of the potential. Accurate numerical calculations are performed with a Lagrange mesh method. The masses predicted are in rather good agreement with lattice results and with some experimental glueball candidates. |
hep-ph/9702343 | null | Eligio Lisi (Bari U. & INFN, Bari), Daniele Montanino (Bari U. & INFN,
Bari) | Earth regeneration effect in solar neutrino oscillations: an analytic
approach | 18 pages (RevTeX) + 12 figures (postscript) included with epsfig.sty.
Misprints in Figs. 4 and 8 corrected | Phys.Rev.D56:1792-1803,1997 | 10.1103/PhysRevD.56.1792 | BARI-TH/260-97 | hep-ph astro-ph | null | We present a simple and accurate method for computing analytically the
regeneration probability of solar neutrinos in the Earth. We apply this method
to the calculation of several solar model independent quantities than can be
measured by the SuperKamiokande and Sudbury Neutrino Observatory experiments.
| [
{
"created": "Sat, 15 Feb 1997 09:29:07 GMT",
"version": "v1"
},
{
"created": "Mon, 17 Feb 1997 10:22:35 GMT",
"version": "v2"
}
] | 2009-10-07 | [
[
"Lisi",
"Eligio",
"",
"Bari U. & INFN, Bari"
],
[
"Montanino",
"Daniele",
"",
"Bari U. & INFN,\n Bari"
]
] | We present a simple and accurate method for computing analytically the regeneration probability of solar neutrinos in the Earth. We apply this method to the calculation of several solar model independent quantities than can be measured by the SuperKamiokande and Sudbury Neutrino Observatory experiments. |
hep-ph/0303033 | K. G. Boreskov | K.G.Boreskov, A.B.Kaidalov | Screening and Anti-Screening Effects in J/psi Production on Nuclei | 6 pages, 6 figures. Small changes in wording | JETP Lett. 77 (2003) 599-602; Pisma Zh.Eksp.Teor.Fiz. 77 (2003)
723-727 | 10.1134/1.1600813 | null | hep-ph | null | The nuclear effects in J/psi hadro- and electroproduction on nuclei are
considered in framework of reggeon approach. It is shown that screening regime
which holds for electroproduction at x_F > 0.7 and for hadroproduction at x_F >
-(0.3-0.4) is changed with anti-screening regime for smaller x_F values.
| [
{
"created": "Wed, 5 Mar 2003 13:59:26 GMT",
"version": "v1"
},
{
"created": "Mon, 14 Apr 2003 15:35:50 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Boreskov",
"K. G.",
""
],
[
"Kaidalov",
"A. B.",
""
]
] | The nuclear effects in J/psi hadro- and electroproduction on nuclei are considered in framework of reggeon approach. It is shown that screening regime which holds for electroproduction at x_F > 0.7 and for hadroproduction at x_F > -(0.3-0.4) is changed with anti-screening regime for smaller x_F values. |
1206.4117 | Cai-Dian Lu | Cai-Dian Lu and Wei Wang | Forward-backward asymmetry of $B\to K_J l^+l^-$ decays in SM and new
physics models | 4 pages, latex, talk presented at the 47th Rencontres de Moriond -
QCD conference, La Thuile and Fourth Workshop on Theory, Phenomenology and
Experiments in Flavour Physics, Capri, Italy, 2012 | null | null | DESY 12-093 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We report on our studies of $B\to K_Jl^+l^-$ in the standard model and
several new physics variations, with $K_J$ denoting a kaonic resoanance. In
terms of helicity amplitudes, we derive a compact form for the full angular
distributions, and use them to calculate the branching ratios, forward-backward
asymmetries and polarizations. We have updated the constraints on effective
Wilson coefficients and/or free parameters in these new physics scenarios by
making use of the $B\to K^*l^+l^-$ and $b\to s l^+l^-$ experimental data. Their
impact on $B\to K_J^*l^+l^-$ is subsequently explored and in particular the
zero-crossing point for forward-backward asymmetry in new physics scenarios can
sizably deviate from the standard model.
| [
{
"created": "Tue, 19 Jun 2012 03:47:48 GMT",
"version": "v1"
}
] | 2012-06-20 | [
[
"Lu",
"Cai-Dian",
""
],
[
"Wang",
"Wei",
""
]
] | We report on our studies of $B\to K_Jl^+l^-$ in the standard model and several new physics variations, with $K_J$ denoting a kaonic resoanance. In terms of helicity amplitudes, we derive a compact form for the full angular distributions, and use them to calculate the branching ratios, forward-backward asymmetries and polarizations. We have updated the constraints on effective Wilson coefficients and/or free parameters in these new physics scenarios by making use of the $B\to K^*l^+l^-$ and $b\to s l^+l^-$ experimental data. Their impact on $B\to K_J^*l^+l^-$ is subsequently explored and in particular the zero-crossing point for forward-backward asymmetry in new physics scenarios can sizably deviate from the standard model. |
0911.0676 | Michael Strickland | Jens O. Andersen, Michael Strickland, and Nan Su | Gluon Thermodynamics at Intermediate Coupling | 4 pages, 3 figures; v2 - published version. | Phys.Rev.Lett.104:122003,2010 | 10.1103/PhysRevLett.104.122003 | null | hep-ph hep-th nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We calculate the thermodynamic functions of Yang-Mills theory to three-loop
order using the hard-thermal-loop perturbation theory reorganization of finite
temperature quantum field theory. We show that at three-loop order
hard-thermal-loop perturbation theory is compatible with lattice results for
the pressure, energy density, and entropy down to temperatures T ~ 2 - 3 T_c.
| [
{
"created": "Tue, 3 Nov 2009 21:10:32 GMT",
"version": "v1"
},
{
"created": "Wed, 31 Mar 2010 23:08:39 GMT",
"version": "v2"
}
] | 2015-03-13 | [
[
"Andersen",
"Jens O.",
""
],
[
"Strickland",
"Michael",
""
],
[
"Su",
"Nan",
""
]
] | We calculate the thermodynamic functions of Yang-Mills theory to three-loop order using the hard-thermal-loop perturbation theory reorganization of finite temperature quantum field theory. We show that at three-loop order hard-thermal-loop perturbation theory is compatible with lattice results for the pressure, energy density, and entropy down to temperatures T ~ 2 - 3 T_c. |
hep-ph/9412210 | Alan Steif | G.W. Gibbons and Alan R. Steif | Sphalerons and Conformally Compactified Minkowski Spacetime | 12 pages, tex, 2 references and comment added | Phys.Lett.B346:255-261,1995 | 10.1016/0370-2693(94)00005-R | DAMTP/R94/53, UCD-PHY-94-41 | hep-ph gr-qc hep-th | null | Solutions to the Yang-Mills field equations which describe exploding or
imploding shells of gauge field and which may serve as approximations to the
exploding sphaleron are discussed. The solutions are conformally related to
$SO(2)\times SO(4)$ invariant Yang-Mills solutions. The behavior of fermions in
the gauge field background and higher gauge groups are also considered.
| [
{
"created": "Thu, 1 Dec 1994 19:43:18 GMT",
"version": "v1"
},
{
"created": "Mon, 9 Jan 1995 18:52:32 GMT",
"version": "v2"
}
] | 2009-10-07 | [
[
"Gibbons",
"G. W.",
""
],
[
"Steif",
"Alan R.",
""
]
] | Solutions to the Yang-Mills field equations which describe exploding or imploding shells of gauge field and which may serve as approximations to the exploding sphaleron are discussed. The solutions are conformally related to $SO(2)\times SO(4)$ invariant Yang-Mills solutions. The behavior of fermions in the gauge field background and higher gauge groups are also considered. |
hep-ph/0309166 | L. Wolfenstein | Lincoln Wolfenstein Ph.D | Strong Phases in the Decays B to D Pi | 4 pages (includes 1 reference page) | Phys.Rev. D69 (2004) 016006 | null | CMU-HEP-03-12 | hep-ph | null | The observed strong phase difference of 30^{o} between I=(3/2) and I=(1/2)
final states for the decay B to D Pi is analyzed in terms of rescattering like
D^{∗}Pi to D Pi, etc. It is concluded that for the decay B^{o}to D^{+}
Pi^{-} the strong phase is only about 10^{o}. Implications for the
determination of sin(2 Beta + gamma) are discussed.
| [
{
"created": "Mon, 15 Sep 2003 18:13:43 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"D",
"Lincoln Wolfenstein Ph.",
""
]
] | The observed strong phase difference of 30^{o} between I=(3/2) and I=(1/2) final states for the decay B to D Pi is analyzed in terms of rescattering like D^{∗}Pi to D Pi, etc. It is concluded that for the decay B^{o}to D^{+} Pi^{-} the strong phase is only about 10^{o}. Implications for the determination of sin(2 Beta + gamma) are discussed. |
hep-ph/9905366 | null | Jonathan L. Rosner | Final-State Phases in Charmed Meson Two-Body Nonleptonic Decays | 19 pages, latex, 4 figures, to be submitted to Phys. Rev. D | Phys. Rev. D 60, 114026 (1999) | 10.1103/PhysRevD.60.114026 | EFI-99-20 | hep-ph | null | Observed decay rates indicate large phase differences among the amplitudes
for the charge states in $D \to \bar K \pi$ and $D \to \bar K^* \pi$ but
relatively real amplitudes in the charge states for $D \to \bar K \rho$. This
feature is traced using an SU(3) flavor analysis to a sign flip in the
contribution of one of the amplitudes contributing to the latter processes in
comparison with its contribution to the other two sets. This amplitude may be
regarded as an effect of rescattering and is found to be of magnitude
comparable to others contributing to charmed particle two-body nonleptonic
decays.
| [
{
"created": "Mon, 17 May 1999 14:12:52 GMT",
"version": "v1"
}
] | 2016-08-25 | [
[
"Rosner",
"Jonathan L.",
""
]
] | Observed decay rates indicate large phase differences among the amplitudes for the charge states in $D \to \bar K \pi$ and $D \to \bar K^* \pi$ but relatively real amplitudes in the charge states for $D \to \bar K \rho$. This feature is traced using an SU(3) flavor analysis to a sign flip in the contribution of one of the amplitudes contributing to the latter processes in comparison with its contribution to the other two sets. This amplitude may be regarded as an effect of rescattering and is found to be of magnitude comparable to others contributing to charmed particle two-body nonleptonic decays. |
hep-ph/9607397 | null | Michael Dine, Yosef Nir and Yuri Shirman | Variations on Minimal Gauge Mediated Supersymmetry Breaking | 22 pages, 1 Postscript figure included, uses harvmac, epsf. Two
references corrected | Phys.Rev.D55:1501-1508,1997 | 10.1103/PhysRevD.55.1501 | SCIPP 96/30, WIS-96/29/Jul-PH | hep-ph | null | We study various modifications to the minimal models of gauge mediated
supersymmetry breaking. We argue that, under reasonable assumptions, the
structure of the messenger sector is rather restricted. We investigate the
effects of possible mixing between messenger and ordinary squark and slepton
fields and, in particular, violation of universality. We show that acceptable
values for the $\mu$ and $B$ parameters can naturally arise from discrete,
possibly horizontal, symmetries. We claim that in models where the
supersymmetry breaking parameters $A$ and $B$ vanish at tree level, $\tan\beta$
could be large without fine tuning. We explain how the supersymmetric CP
problem is solved in such models.
| [
{
"created": "Tue, 23 Jul 1996 06:12:18 GMT",
"version": "v1"
},
{
"created": "Wed, 31 Jul 1996 06:18:20 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"Dine",
"Michael",
""
],
[
"Nir",
"Yosef",
""
],
[
"Shirman",
"Yuri",
""
]
] | We study various modifications to the minimal models of gauge mediated supersymmetry breaking. We argue that, under reasonable assumptions, the structure of the messenger sector is rather restricted. We investigate the effects of possible mixing between messenger and ordinary squark and slepton fields and, in particular, violation of universality. We show that acceptable values for the $\mu$ and $B$ parameters can naturally arise from discrete, possibly horizontal, symmetries. We claim that in models where the supersymmetry breaking parameters $A$ and $B$ vanish at tree level, $\tan\beta$ could be large without fine tuning. We explain how the supersymmetric CP problem is solved in such models. |
1401.3399 | Saurabh Gupta | Gauhar Abbas, Saurabh Gupta, G. Rajasekaran, Rahul Srivastava | Predictions from High Scale Mixing Unification Hypothesis | 22 pages, 9 figures, typos fixed, published version | Phys. Rev. D 89, 093009 (2014) | 10.1103/PhysRevD.89.093009 | null | hep-ph hep-ex hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the renormalization group evolution of masses and mixing
angles of Majorana neutrinos under the `High Scale Mixing Unification'
hypothesis. Assuming the unification of quark-lepton mixing angles at a high
scale, we show that all the experimentally observed neutrino oscillation
parameters can be obtained, within 3-$\sigma$ range, through the running of
corresponding renormalization group equations provided neutrinos have same CP
parity and are quasi-degenerate. One of the novel results of our analysis is
that $\theta_{23}$ turns out to be non-maximal and lies in the second octant.
Furthermore, we derive new constraints on the allowed parameter space for the
unification scale, SUSY breaking scale and $\tan \beta$, for which the `High
Scale Mixing Unification' hypothesis works.
| [
{
"created": "Wed, 15 Jan 2014 01:29:44 GMT",
"version": "v1"
},
{
"created": "Wed, 30 Apr 2014 02:50:23 GMT",
"version": "v2"
},
{
"created": "Thu, 22 May 2014 17:57:14 GMT",
"version": "v3"
}
] | 2014-05-23 | [
[
"Abbas",
"Gauhar",
""
],
[
"Gupta",
"Saurabh",
""
],
[
"Rajasekaran",
"G.",
""
],
[
"Srivastava",
"Rahul",
""
]
] | We investigate the renormalization group evolution of masses and mixing angles of Majorana neutrinos under the `High Scale Mixing Unification' hypothesis. Assuming the unification of quark-lepton mixing angles at a high scale, we show that all the experimentally observed neutrino oscillation parameters can be obtained, within 3-$\sigma$ range, through the running of corresponding renormalization group equations provided neutrinos have same CP parity and are quasi-degenerate. One of the novel results of our analysis is that $\theta_{23}$ turns out to be non-maximal and lies in the second octant. Furthermore, we derive new constraints on the allowed parameter space for the unification scale, SUSY breaking scale and $\tan \beta$, for which the `High Scale Mixing Unification' hypothesis works. |
1902.02607 | Bithika Karmakar | Bithika Karmakar, Ritesh Ghosh, Aritra Bandyopadhyay, Najmul Haque,
Munshi G Mustafa | Anisotropic pressure of deconfined QCD matter in presence of strong
magnetic field within one-loop approximation | 37 pages, 8 figures | Phys. Rev. D 99, 094002 (2019) | 10.1103/PhysRevD.99.094002 | null | hep-ph hep-lat nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Considering the general structure of the two point functions of quarks and
gluons, we compute the free energy and pressure of a strongly magnetized hot
and dense QCD matter created in heavy-ion collisions. In presence of strong
magnetic field we found that the deconfined QCD matter exhibits a paramagnetic
nature. One gets different pressure in a direction parallel and perpendicular
to magnetic field due to the magnetization acquired by the system. We obtain
both longitudinal and transverse pressure, and magnetization of a hot
deconfined QCD matter in presence of magnetic field. We have used hard thermal
loop approximation (HTL) for heat bath. We obtained completely analytic
expression for pressure and magnetization under certain approximation. Various
divergences appearing in free energy are regulated using appropriate counter
terms. The obtained anisotropic pressure may be useful for magnetohydrodynamics
description of a hot and dense deconfined QCD matter produced in heavy-ion
collisions.
| [
{
"created": "Thu, 7 Feb 2019 13:15:51 GMT",
"version": "v1"
},
{
"created": "Sun, 5 May 2019 07:23:04 GMT",
"version": "v2"
}
] | 2019-05-07 | [
[
"Karmakar",
"Bithika",
""
],
[
"Ghosh",
"Ritesh",
""
],
[
"Bandyopadhyay",
"Aritra",
""
],
[
"Haque",
"Najmul",
""
],
[
"Mustafa",
"Munshi G",
""
]
] | Considering the general structure of the two point functions of quarks and gluons, we compute the free energy and pressure of a strongly magnetized hot and dense QCD matter created in heavy-ion collisions. In presence of strong magnetic field we found that the deconfined QCD matter exhibits a paramagnetic nature. One gets different pressure in a direction parallel and perpendicular to magnetic field due to the magnetization acquired by the system. We obtain both longitudinal and transverse pressure, and magnetization of a hot deconfined QCD matter in presence of magnetic field. We have used hard thermal loop approximation (HTL) for heat bath. We obtained completely analytic expression for pressure and magnetization under certain approximation. Various divergences appearing in free energy are regulated using appropriate counter terms. The obtained anisotropic pressure may be useful for magnetohydrodynamics description of a hot and dense deconfined QCD matter produced in heavy-ion collisions. |
2112.03522 | Peng-Cheng Lu | Qi-Li Liao, Jun Jiang, Peng-Cheng Lu, Gu Chen | Production of excited heavy quarkonia in $e^+e^- \to \gamma^*/Z^0 \to
|(Q\bar{Q})[n]\rangle +\gamma$ at super $Z$ factory | 11 pages,5 figures, 8 tables | null | 10.1103/PhysRevD.105.016026 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | Within the nonrelativistic quantum chromodynamics framework, we make a
comprehensive study on the exclusive production of excited charmonium and
bottomonium in $e^+e^-\to \gamma^*/Z^0 \to|(Q\bar{Q})[n]\rangle +\gamma$ ($Q=c$
or $b$ quarks) at future $Z$ factory, where the $[n]$ represents the
color-singlet $n^1S_0,~n^3S_1,~n^1P_0$ and $n^3P_J$ ($n=1,2,3,4; J=0,1,2$) Fock
states. The "improved trace technology" is adopted to derive the analytic
expressions at the amplitude level, which is useful for calculating the
complicated $nP$-wave channels. Total cross sections, differential
distributions, and uncertainties are discussed in system. According to our
study, production rates of heavy quarkonia of high excited Fock states are
considerable at future $Z$ factory. The cross sections of charmonium for $2S$,
$3S$, $4S$, $1P$, $2P$, $3P$ and $4P$-wave states are about $53.5\%$, $30.4\%$,
$23.7\%$, $13.7\%$, $6.8\%$, $9.2\%$, and $9.2\%$ of that of the $1S$ state,
respectively. And cross sections of bottomonium for $2S$, $3S$, $4S$, $1P$,
$2P$, $3P$ and $4P$-wave states are about $39.3\%$, $12.3\%$, $14.3\%$,
$7.1\%$, $3.1\%$, $2.7\%$, and $3.1\%$ of that of the $1S$ state, respectively.
The main uncertainties come from the radial wave functions at the origin and
their derivatives at the origin under different potential models. Then, such
super $Z$ factory should be a good platform to study the properties of the high
excited charmonium and bottomonium states.
| [
{
"created": "Tue, 7 Dec 2021 06:35:28 GMT",
"version": "v1"
}
] | 2022-02-09 | [
[
"Liao",
"Qi-Li",
""
],
[
"Jiang",
"Jun",
""
],
[
"Lu",
"Peng-Cheng",
""
],
[
"Chen",
"Gu",
""
]
] | Within the nonrelativistic quantum chromodynamics framework, we make a comprehensive study on the exclusive production of excited charmonium and bottomonium in $e^+e^-\to \gamma^*/Z^0 \to|(Q\bar{Q})[n]\rangle +\gamma$ ($Q=c$ or $b$ quarks) at future $Z$ factory, where the $[n]$ represents the color-singlet $n^1S_0,~n^3S_1,~n^1P_0$ and $n^3P_J$ ($n=1,2,3,4; J=0,1,2$) Fock states. The "improved trace technology" is adopted to derive the analytic expressions at the amplitude level, which is useful for calculating the complicated $nP$-wave channels. Total cross sections, differential distributions, and uncertainties are discussed in system. According to our study, production rates of heavy quarkonia of high excited Fock states are considerable at future $Z$ factory. The cross sections of charmonium for $2S$, $3S$, $4S$, $1P$, $2P$, $3P$ and $4P$-wave states are about $53.5\%$, $30.4\%$, $23.7\%$, $13.7\%$, $6.8\%$, $9.2\%$, and $9.2\%$ of that of the $1S$ state, respectively. And cross sections of bottomonium for $2S$, $3S$, $4S$, $1P$, $2P$, $3P$ and $4P$-wave states are about $39.3\%$, $12.3\%$, $14.3\%$, $7.1\%$, $3.1\%$, $2.7\%$, and $3.1\%$ of that of the $1S$ state, respectively. The main uncertainties come from the radial wave functions at the origin and their derivatives at the origin under different potential models. Then, such super $Z$ factory should be a good platform to study the properties of the high excited charmonium and bottomonium states. |
0809.0122 | Jungil Lee | Hee Sok Chung, Jungil Lee, Chaehyun Yu (Korea U.) | Recent Developments in Heavy-Quarkonium Phenomenology | 8 pages, talk given by Jungil Lee at The Eighth International
Conference on Hyperons, Charm and Beauty Hadrons (BEACH 2008), Columbia,
South Carolina, USA, June 22-28, 2008 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We review recent developments in heavy-quarkonium phenomenology within the
nonrelativistic QCD factorization approach. Main issues we consider in this
work include the polarization of prompt J/psi at the Fermilab Tevatron and the
large relativistic and QCD corrections to double-charmonium production at the B
factories. We also consider inclusive charm production in bottomonia decays.
| [
{
"created": "Sun, 31 Aug 2008 13:44:48 GMT",
"version": "v1"
}
] | 2008-09-02 | [
[
"Chung",
"Hee Sok",
"",
"Korea U."
],
[
"Lee",
"Jungil",
"",
"Korea U."
],
[
"Yu",
"Chaehyun",
"",
"Korea U."
]
] | We review recent developments in heavy-quarkonium phenomenology within the nonrelativistic QCD factorization approach. Main issues we consider in this work include the polarization of prompt J/psi at the Fermilab Tevatron and the large relativistic and QCD corrections to double-charmonium production at the B factories. We also consider inclusive charm production in bottomonia decays. |
hep-ph/0609150 | Marc Sher | Christopher D. Carone, Marc Sher and Marc Vanderhaeghen (William and
Mary) | New Bounds on Isotropic Lorentz Violation | 10 pages, 1 figure. v2: reference added | Phys.Rev.D74:077901,2006 | 10.1103/PhysRevD.74.077901 | WM-06-108 | hep-ph | null | Violations of Lorentz invariance that appear via operators of dimension four
or less are completely parameterized in the Standard Model Extension (SME). In
the pure photonic sector of the SME, there are nineteen dimensionless,
Lorentz-violating parameters. Eighteen of these have experimental upper bounds
ranging between 10^{-11} and 10^{-32}; the remaining parameter, k_tr, is
isotropic and has a much weaker bound of order 10^{-4}. In this Brief Report,
we point out that k_tr gives a significant contribution to the anomalous
magnetic moment of the electron and find a new upper bound of order 10^{-8}.
With reasonable assumptions, we further show that this bound may be improved to
10^{-14} by considering the renormalization of other Lorentz-violating
parameters that are more tightly constrained. Using similar renormalization
arguments, we also estimate bounds on Lorentz violating parameters in the pure
gluonic sector of QCD.
| [
{
"created": "Fri, 15 Sep 2006 14:57:39 GMT",
"version": "v1"
},
{
"created": "Fri, 13 Oct 2006 13:43:18 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Carone",
"Christopher D.",
"",
"William and\n Mary"
],
[
"Sher",
"Marc",
"",
"William and\n Mary"
],
[
"Vanderhaeghen",
"Marc",
"",
"William and\n Mary"
]
] | Violations of Lorentz invariance that appear via operators of dimension four or less are completely parameterized in the Standard Model Extension (SME). In the pure photonic sector of the SME, there are nineteen dimensionless, Lorentz-violating parameters. Eighteen of these have experimental upper bounds ranging between 10^{-11} and 10^{-32}; the remaining parameter, k_tr, is isotropic and has a much weaker bound of order 10^{-4}. In this Brief Report, we point out that k_tr gives a significant contribution to the anomalous magnetic moment of the electron and find a new upper bound of order 10^{-8}. With reasonable assumptions, we further show that this bound may be improved to 10^{-14} by considering the renormalization of other Lorentz-violating parameters that are more tightly constrained. Using similar renormalization arguments, we also estimate bounds on Lorentz violating parameters in the pure gluonic sector of QCD. |
1405.4295 | Matthias Schlaffer | Matthias Schlaffer, Michael Spannowsky, Michihisa Takeuchi, Andreas
Weiler, and Chris Wymant | Boosted Higgs Shapes | 17 pages, 7 figures, 6 tables. Added references and minor
clarifications. Matches published version | Eur.Phys.J. C74 (2014) 3120 | 10.1140/epjc/s10052-014-3120-z | IPPP/14/35, DCPT/14/70, CERN-PH-TH/2014-083, DESY/14-069,
KCL-PH-TH/2014-22 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The inclusive Higgs production rate through gluon fusion has been measured to
be in agreement with the Standard Model (SM). We show that even if the
inclusive Higgs production rate is very SM-like, a precise determination of the
boosted Higgs transverse momentum shape offers the opportunity to see effects
of natural new physics. These measurements are generically motivated by
effective field theory arguments and specifically in extensions of the SM with
a natural weak scale, like composite Higgs models and natural supersymmetry. We
show in detail how a measurement at high transverse momentum of $H\to
2\ell+\mathbf{p}\!\!/_T$ via $H\to \tau\tau$ and $H\to WW^*$ could be performed
and demonstrate that it offers a compelling alternative to the $t\bar t H$
channel. We discuss the sensitivity to new physics in the most challenging
scenario of an exactly SM-like inclusive Higgs cross-section.
| [
{
"created": "Fri, 16 May 2014 20:01:34 GMT",
"version": "v1"
},
{
"created": "Tue, 11 Nov 2014 10:31:46 GMT",
"version": "v2"
}
] | 2015-06-19 | [
[
"Schlaffer",
"Matthias",
""
],
[
"Spannowsky",
"Michael",
""
],
[
"Takeuchi",
"Michihisa",
""
],
[
"Weiler",
"Andreas",
""
],
[
"Wymant",
"Chris",
""
]
] | The inclusive Higgs production rate through gluon fusion has been measured to be in agreement with the Standard Model (SM). We show that even if the inclusive Higgs production rate is very SM-like, a precise determination of the boosted Higgs transverse momentum shape offers the opportunity to see effects of natural new physics. These measurements are generically motivated by effective field theory arguments and specifically in extensions of the SM with a natural weak scale, like composite Higgs models and natural supersymmetry. We show in detail how a measurement at high transverse momentum of $H\to 2\ell+\mathbf{p}\!\!/_T$ via $H\to \tau\tau$ and $H\to WW^*$ could be performed and demonstrate that it offers a compelling alternative to the $t\bar t H$ channel. We discuss the sensitivity to new physics in the most challenging scenario of an exactly SM-like inclusive Higgs cross-section. |
1805.05625 | Robert Fleischer | Robert Fleischer | New Probes of New Physics with Leptonic Rare B Decays | 6 pages, 4 figures, invited talk at Rencontres de Moriond 2018, QCD
and High Energy Interactions, La Thuile, Italy, 17-24 March 2018, to appear
in the Proceedings | null | null | Nikhef-2018-019 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Decays of the kind $B^0_{s,d}\to\ell^+\ell^-$ belong to the most favourable
processes for probing the flavour structure of the Standard Model, with
outstanding sensitivity to new (pseudo)-scalar contributions. While the
branching ratio of $B^0_s\to\mu^+\mu^-$ has already been measured at the LHC in
the ballpark of the Standard Model expectation, there is still significant room
for New-Physics effects. We discuss how these may be revealed in the future
super-high precision era of $B$-decay studies by utilising new theoretically
clean observables, including CP-violating asymmetries. Another promising decay
is $B^0_{s}\to e^+e^-$, which has received little attention in view of its
enormously helicity suppressed Standard Model branching ratio, with the most
recent experimental upper bound dating back to 2009. Using the current
constraints on New Physics from $B^0_s\to\mu^+\mu^-$ as a guideline, we show
that the $B^0_s\to e^+e^-$ branching ratio may be hugely enhanced through new
(pseudo)-scalar contributions up to the regime of $B^0_{s}\to\mu^+\mu^-$.
| [
{
"created": "Tue, 15 May 2018 08:16:43 GMT",
"version": "v1"
}
] | 2018-05-16 | [
[
"Fleischer",
"Robert",
""
]
] | Decays of the kind $B^0_{s,d}\to\ell^+\ell^-$ belong to the most favourable processes for probing the flavour structure of the Standard Model, with outstanding sensitivity to new (pseudo)-scalar contributions. While the branching ratio of $B^0_s\to\mu^+\mu^-$ has already been measured at the LHC in the ballpark of the Standard Model expectation, there is still significant room for New-Physics effects. We discuss how these may be revealed in the future super-high precision era of $B$-decay studies by utilising new theoretically clean observables, including CP-violating asymmetries. Another promising decay is $B^0_{s}\to e^+e^-$, which has received little attention in view of its enormously helicity suppressed Standard Model branching ratio, with the most recent experimental upper bound dating back to 2009. Using the current constraints on New Physics from $B^0_s\to\mu^+\mu^-$ as a guideline, we show that the $B^0_s\to e^+e^-$ branching ratio may be hugely enhanced through new (pseudo)-scalar contributions up to the regime of $B^0_{s}\to\mu^+\mu^-$. |
1506.09205 | Nathan Holt | Nathan P. M. Holt, Paul M. Hohler, and Ralf Rapp | Thermal photon emission from the pi-rho-omega system | 14 pages, 16 figures, published in Nuclear Physics A | Nuc. Phys. A 945 (2016) 1-20 | 10.1016/j.nuclphysa.2015.09.008 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate thermal photon emission rates in hot hadronic matter from a
system consisting of pi, rho, and omega mesons. The rates are calculated using
both relativistic kinetic theory with Born diagrams as well as thermal field
theory at the two-loop level. This enables us to cross-check our calculations
and to manage a pole contribution that arises in the Born approximation
corresponding to the omega -> pi^0 gamma radiative decay. After implementing
hadronic form factors to account for finite-size corrections, we find that the
resulting photo-emission rates are comparable to existing results from pi rho
-> pi gamma processes in the energy regime of 1-3 GeV. We expect that our new
sources will provide a non-negligible contribution to the total hadronic rates,
thereby enhancing calculated thermal photon spectra from heavy-ion collisions,
which could improve the description of current direct-photon data from
experiment.
| [
{
"created": "Tue, 30 Jun 2015 19:28:35 GMT",
"version": "v1"
},
{
"created": "Tue, 27 Oct 2015 03:35:28 GMT",
"version": "v2"
}
] | 2015-10-28 | [
[
"Holt",
"Nathan P. M.",
""
],
[
"Hohler",
"Paul M.",
""
],
[
"Rapp",
"Ralf",
""
]
] | We investigate thermal photon emission rates in hot hadronic matter from a system consisting of pi, rho, and omega mesons. The rates are calculated using both relativistic kinetic theory with Born diagrams as well as thermal field theory at the two-loop level. This enables us to cross-check our calculations and to manage a pole contribution that arises in the Born approximation corresponding to the omega -> pi^0 gamma radiative decay. After implementing hadronic form factors to account for finite-size corrections, we find that the resulting photo-emission rates are comparable to existing results from pi rho -> pi gamma processes in the energy regime of 1-3 GeV. We expect that our new sources will provide a non-negligible contribution to the total hadronic rates, thereby enhancing calculated thermal photon spectra from heavy-ion collisions, which could improve the description of current direct-photon data from experiment. |
1406.1993 | Huitzu Tu | Kin-Wang Ng, Huitzu Tu, and Tzu-Chiang Yuan | Dark Photon as Fractional Cosmic Neutrino Masquerader | 19 pages, 3 figures | null | 10.1088/1475-7516/2014/09/035 | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Recently, Weinberg proposed a Higgs portal model with a spontaneously broken
global $U(1)$ symmetry in which Goldstone bosons may be masquerading as
fractional cosmic neutrinos. We extend the model by gauging the $U(1)$
symmetry. This gives rise to the so-called dark photon and dark Higgs. The dark
photons can constitute about 0.912 (0.167) to the effective number of light
neutrino species if they decouple from the thermal bath before the pions become
non-relativistic and after (before) the QCD transition. Restriction on the
parameter space of the portal coupling and the dark Higgs mass is obtained from
the freeze-out condition of the dark photons. Combining with the collider data
constraints on the invisible width of the standard model Higgs requires the
dark Higgs mass to be less than a few GeV.
| [
{
"created": "Sun, 8 Jun 2014 15:36:44 GMT",
"version": "v1"
}
] | 2015-06-19 | [
[
"Ng",
"Kin-Wang",
""
],
[
"Tu",
"Huitzu",
""
],
[
"Yuan",
"Tzu-Chiang",
""
]
] | Recently, Weinberg proposed a Higgs portal model with a spontaneously broken global $U(1)$ symmetry in which Goldstone bosons may be masquerading as fractional cosmic neutrinos. We extend the model by gauging the $U(1)$ symmetry. This gives rise to the so-called dark photon and dark Higgs. The dark photons can constitute about 0.912 (0.167) to the effective number of light neutrino species if they decouple from the thermal bath before the pions become non-relativistic and after (before) the QCD transition. Restriction on the parameter space of the portal coupling and the dark Higgs mass is obtained from the freeze-out condition of the dark photons. Combining with the collider data constraints on the invisible width of the standard model Higgs requires the dark Higgs mass to be less than a few GeV. |
2104.02589 | Oscar Acevedo | O. A. Acevedo and B. M. Pimentel | Radiative corrections in the Yukawa model within the null-plane causal
perturbation theory framework | 12 pages; to be published in Phys. Rev. D | Phys. Rev. D 103, 076022 (2021) | 10.1103/PhysRevD.103.076022 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Practical calculations in light-front dynamics are, as a general rule,
complicated, since there is no consensus about how to treat the poles which
come from the instantaneous parts of Feynman's propagators of the fields. An
alternative to solve this difficulty is null-plane causal perturbation theory,
a recent developed framework which prevents the appearance of the mentioned
poles by avoiding the usage of Feynman's propagators in "loop distributions",
requiring no regularization of the amplitudes. In this study, we treat the
radiative corrections in the neutral Yukawa's model in that framework.
Particularly, we explicitly calculate the boson and fermion self-energies and
show that the results obtained with this approach are equivalent to that of the
instant dynamics.
| [
{
"created": "Tue, 6 Apr 2021 15:27:12 GMT",
"version": "v1"
}
] | 2021-05-05 | [
[
"Acevedo",
"O. A.",
""
],
[
"Pimentel",
"B. M.",
""
]
] | Practical calculations in light-front dynamics are, as a general rule, complicated, since there is no consensus about how to treat the poles which come from the instantaneous parts of Feynman's propagators of the fields. An alternative to solve this difficulty is null-plane causal perturbation theory, a recent developed framework which prevents the appearance of the mentioned poles by avoiding the usage of Feynman's propagators in "loop distributions", requiring no regularization of the amplitudes. In this study, we treat the radiative corrections in the neutral Yukawa's model in that framework. Particularly, we explicitly calculate the boson and fermion self-energies and show that the results obtained with this approach are equivalent to that of the instant dynamics. |
1907.05370 | Gian Francesco Giudice | G.F. Giudice, A. Kehagias, A. Riotto | The Selfish Higgs | 17 pages, 1 figure (one reference added in revised version) | null | 10.1007/JHEP10(2019)199 | CERN-TH-2019-114 | hep-ph astro-ph.CO hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose a mechanism to solve the Higgs naturalness problem through a
cosmological selection process. The discharging of excited field configurations
through membrane nucleation leads to discrete jumps of the cosmological
constant and the Higgs mass, which vary in a correlated way. The resulting
multitude of universes are all empty, except for those in which the
cosmological constant and the Higgs mass are both nearly vanishing. Only under
these critical conditions can inflation be activated and create a non-empty
universe.
| [
{
"created": "Thu, 11 Jul 2019 16:49:03 GMT",
"version": "v1"
},
{
"created": "Tue, 27 Aug 2019 07:44:16 GMT",
"version": "v2"
},
{
"created": "Sun, 25 Apr 2021 07:32:17 GMT",
"version": "v3"
}
] | 2021-04-27 | [
[
"Giudice",
"G. F.",
""
],
[
"Kehagias",
"A.",
""
],
[
"Riotto",
"A.",
""
]
] | We propose a mechanism to solve the Higgs naturalness problem through a cosmological selection process. The discharging of excited field configurations through membrane nucleation leads to discrete jumps of the cosmological constant and the Higgs mass, which vary in a correlated way. The resulting multitude of universes are all empty, except for those in which the cosmological constant and the Higgs mass are both nearly vanishing. Only under these critical conditions can inflation be activated and create a non-empty universe. |
0911.0560 | Shinya Matsuzaki | Deog Ki Hong, Doyoun Kim, and Shinya Matsuzaki | Holographic calculation of hadronic contributions to muon g-2 | 12 pages, latex, references added | Phys.Rev.D81:073005,2010 | 10.1103/PhysRevD.81.073005 | null | hep-ph hep-th nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Using the gauge/gravity duality, we compute the leading order hadronic (HLO)
contribution to the anomalous magnetic moment of muon, amu(HLO). Holographic
renormalization is used to obtain a finite vacuum polarization. We find
amu(HLO) =470.5 x 10^{-10} in AdS/QCD with two light flavors, which is compared
with the currently revised BABAR data estimated from e^+ e^- -> pi^+ pi^-
events, amu(HLO)[pipi]=(514.1 +- 3.8) x 10^{-10}.
| [
{
"created": "Tue, 3 Nov 2009 14:38:08 GMT",
"version": "v1"
},
{
"created": "Sun, 15 Nov 2009 10:44:04 GMT",
"version": "v2"
}
] | 2010-04-21 | [
[
"Hong",
"Deog Ki",
""
],
[
"Kim",
"Doyoun",
""
],
[
"Matsuzaki",
"Shinya",
""
]
] | Using the gauge/gravity duality, we compute the leading order hadronic (HLO) contribution to the anomalous magnetic moment of muon, amu(HLO). Holographic renormalization is used to obtain a finite vacuum polarization. We find amu(HLO) =470.5 x 10^{-10} in AdS/QCD with two light flavors, which is compared with the currently revised BABAR data estimated from e^+ e^- -> pi^+ pi^- events, amu(HLO)[pipi]=(514.1 +- 3.8) x 10^{-10}. |
hep-ph/0307160 | Silvano Simula | Silvano Simula | Longitudinal structure function of the proton at low momentum transfer
and extended constituents | revised version to appear in PLB with minor changes. No change in the
results and in the conclusions | Phys.Lett. B574 (2003) 189-196 | 10.1016/j.physletb.2003.09.032 | preprint RM3-TH/03-8 | hep-ph nucl-th | null | Recent data on the (inelastic) Nachtmann moments of the unpolarized proton
structure function F2p, obtained at low momentum transfer with the CLAS
detector at Jefferson Lab, have been interpreted in terms of the dominance of
the elastic coupling of the virtual photon with extended substructures inside
the proton. Adopting the same constituent form factors and the same light-front
wave function describing the motion of the constituents in the proton, the
(inelastic) Nachtmann moments of the longitudinal proton structure function FLp
are calculated (without further parameters) for values of the squared
four-momentum transfer 0.2 < Q**2 (GeV/c)**2 < 2. The different role played by
the Pauli form factor of the constituents in the transverse and longitudinal
channels is illustrated. Our predictions, including an estimate of the
theoretical uncertainties, may be checked against the forthcoming results of
the experiment E94110 at Jefferson Lab. A positive comparison with the new data
may provide compelling evidence that constituent quarks are intermediate
substructures between the hadrons and the current quarks and gluons of QCD.
| [
{
"created": "Fri, 11 Jul 2003 11:15:17 GMT",
"version": "v1"
},
{
"created": "Fri, 12 Sep 2003 15:55:21 GMT",
"version": "v2"
}
] | 2015-06-25 | [
[
"Simula",
"Silvano",
""
]
] | Recent data on the (inelastic) Nachtmann moments of the unpolarized proton structure function F2p, obtained at low momentum transfer with the CLAS detector at Jefferson Lab, have been interpreted in terms of the dominance of the elastic coupling of the virtual photon with extended substructures inside the proton. Adopting the same constituent form factors and the same light-front wave function describing the motion of the constituents in the proton, the (inelastic) Nachtmann moments of the longitudinal proton structure function FLp are calculated (without further parameters) for values of the squared four-momentum transfer 0.2 < Q**2 (GeV/c)**2 < 2. The different role played by the Pauli form factor of the constituents in the transverse and longitudinal channels is illustrated. Our predictions, including an estimate of the theoretical uncertainties, may be checked against the forthcoming results of the experiment E94110 at Jefferson Lab. A positive comparison with the new data may provide compelling evidence that constituent quarks are intermediate substructures between the hadrons and the current quarks and gluons of QCD. |
1004.3368 | Hiranmaya Mishra | Awaneesh Singh, Sanjay Puri and Hiranmaya Mishra | Kinetics of chiral phase transition in hot and dense quark matter | 5 pages, 7 figures | null | null | null | hep-ph cond-mat.stat-mech nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The kinetics of chiral transitions in hot and dense quark matter is studied
via a microscopic framework (Nambu-Jona-Lasinio model) and a phenomenological
model (Ginzburg-Landau free energy). We focus on the far-from-equilibrium
ordering dynamics subsequent to a quench from the massless quark phase to the
massive quark phase. The morphology of the ordering system is characterized by
the scaling of the order-parameter correlation function. The domain growth
process obeys the Allen-Cahn growth law, $L(t)\sim t^{1/2}$. We also study the
growth of bubble of the stable massive phase in a background of the metastable
massive phase.
| [
{
"created": "Tue, 20 Apr 2010 07:29:16 GMT",
"version": "v1"
}
] | 2010-04-21 | [
[
"Singh",
"Awaneesh",
""
],
[
"Puri",
"Sanjay",
""
],
[
"Mishra",
"Hiranmaya",
""
]
] | The kinetics of chiral transitions in hot and dense quark matter is studied via a microscopic framework (Nambu-Jona-Lasinio model) and a phenomenological model (Ginzburg-Landau free energy). We focus on the far-from-equilibrium ordering dynamics subsequent to a quench from the massless quark phase to the massive quark phase. The morphology of the ordering system is characterized by the scaling of the order-parameter correlation function. The domain growth process obeys the Allen-Cahn growth law, $L(t)\sim t^{1/2}$. We also study the growth of bubble of the stable massive phase in a background of the metastable massive phase. |
1403.0440 | Emanuele Roberto Nocera | Emanuele Roberto Nocera | Unbiased spin-dependent Parton Distribution Functions | PhD thesis (2014) http://phd.fisica.unimi.it | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the first unbiased determination of spin-dependent, or polarized,
Parton Distribution Functions (PDFs) of the proton. A statistically sound
representation of the corresponding uncertainties is achieved by means of the
NNPDF methodology: this was formerly developed for unpolarized distributions
and is now generalized to the polarized here for the first time. The features
of the procedure, based on robust statistical tools (Monte Carlo sampling for
error propagation, neural networks for PDF parametrization, genetic algorithm
for their minimization, and possibly reweighting for including new data samples
without refitting), are illustrated in detail. Different sets of polarized PDFs
are obtained at next-to-leading order accuracy in perturbative quantum
chromodynamics, based on both fixed-target inclusive deeply-inelastic
scattering data and the most recent polarized collider data. A quantitative
appraisal on the potential role of future measurements at an Electron-Ion
Collider is also presented. We study the stability of our results upon the
variation of several theoretical and methodological assumptions and we present
a detailed investigation of the first moments of our polarized PDFs, compared
to other recent analyses. We find that the uncertainty on the gluon
distribution from available data was substantially underestimated in previous
determinations; in particular, we emphasize that a large contribution to the
gluon may arise from the unmeasured small-x region, against the common belief
that this is actually rather small. We demonstrate that an Electron-Ion
Collider would provide evidence for a possible large gluon contribution to the
nucleon spin, though with a sizable residual uncertainty.
| [
{
"created": "Mon, 3 Mar 2014 14:12:31 GMT",
"version": "v1"
}
] | 2014-03-04 | [
[
"Nocera",
"Emanuele Roberto",
""
]
] | We present the first unbiased determination of spin-dependent, or polarized, Parton Distribution Functions (PDFs) of the proton. A statistically sound representation of the corresponding uncertainties is achieved by means of the NNPDF methodology: this was formerly developed for unpolarized distributions and is now generalized to the polarized here for the first time. The features of the procedure, based on robust statistical tools (Monte Carlo sampling for error propagation, neural networks for PDF parametrization, genetic algorithm for their minimization, and possibly reweighting for including new data samples without refitting), are illustrated in detail. Different sets of polarized PDFs are obtained at next-to-leading order accuracy in perturbative quantum chromodynamics, based on both fixed-target inclusive deeply-inelastic scattering data and the most recent polarized collider data. A quantitative appraisal on the potential role of future measurements at an Electron-Ion Collider is also presented. We study the stability of our results upon the variation of several theoretical and methodological assumptions and we present a detailed investigation of the first moments of our polarized PDFs, compared to other recent analyses. We find that the uncertainty on the gluon distribution from available data was substantially underestimated in previous determinations; in particular, we emphasize that a large contribution to the gluon may arise from the unmeasured small-x region, against the common belief that this is actually rather small. We demonstrate that an Electron-Ion Collider would provide evidence for a possible large gluon contribution to the nucleon spin, though with a sizable residual uncertainty. |
hep-ph/9704428 | Bhaskar Dutta | B. Dutta, R. N. Mohapatra and S. Nandi | Explaining the HERA Anomaly Without Giving Up R-parity Conservation | 5 pages(Latex), 1 Figure, Some additions have been made | Phys.Lett. B412 (1997) 337-342 | 10.1016/S0370-2693(97)01076-9 | OITS-627, UMD-PP-97-108, OSURN-325 | hep-ph | null | We point out that in extended supersymmetric models such as supersymmetric
left-right models, it is possible to have leptoquarks that explain the HERA
high $Q^2$ anomaly without giving up R-parity conservation. The leptoquarks
belong to vectorlike $(2, 2, \pm{4/3}, 3 or 3^*) $ representations of
$SU(2)_L\times SU(2)_R\times U(1)_{B-L}\times SU(3)_c$ (denoted $G_{2213}$).
Unlike the R-parity violating scenario, the leptoquarks are accompanied by new
superpartners,the leptoquarkino which leads to many intersting signatures in
other collider experiments. At Tevatron, pair productions of the leptoquarkino
will give rise to dilepton signals very distinct from the top productions.
These models can lead to unification of gauge coupling constants at a scale of
around $10^{10}$ GeV implying that grand unification group is not of the usual
SU(5) or SO(10) types but rather an automatically R-parity conserving
$SU(5)\times SU(5)$ GUT model recently proposed by one of the authors (R. N.
M.) which leads to a stable proton.
| [
{
"created": "Mon, 28 Apr 1997 23:46:10 GMT",
"version": "v1"
},
{
"created": "Thu, 5 Jun 1997 22:17:44 GMT",
"version": "v2"
}
] | 2009-10-30 | [
[
"Dutta",
"B.",
""
],
[
"Mohapatra",
"R. N.",
""
],
[
"Nandi",
"S.",
""
]
] | We point out that in extended supersymmetric models such as supersymmetric left-right models, it is possible to have leptoquarks that explain the HERA high $Q^2$ anomaly without giving up R-parity conservation. The leptoquarks belong to vectorlike $(2, 2, \pm{4/3}, 3 or 3^*) $ representations of $SU(2)_L\times SU(2)_R\times U(1)_{B-L}\times SU(3)_c$ (denoted $G_{2213}$). Unlike the R-parity violating scenario, the leptoquarks are accompanied by new superpartners,the leptoquarkino which leads to many intersting signatures in other collider experiments. At Tevatron, pair productions of the leptoquarkino will give rise to dilepton signals very distinct from the top productions. These models can lead to unification of gauge coupling constants at a scale of around $10^{10}$ GeV implying that grand unification group is not of the usual SU(5) or SO(10) types but rather an automatically R-parity conserving $SU(5)\times SU(5)$ GUT model recently proposed by one of the authors (R. N. M.) which leads to a stable proton. |
hep-ph/0209136 | Carl Shakin | Hu Li and C. M. Shakin | Chiral Symmetry Restoration and Deconfinement of Light Mesons at Finite
Temperature | 17 pages, 10 figures, Revtex4 tex file | null | null | null | hep-ph hep-lat | null | There has been a great deal of interest in understanding the properties of
quantum chromodynamics (QCD) for a finite value of the chemical potential and
for finite temperature. Studies have been made of the restoration of chiral
symmetry in matter and at finite temperature. The phenomenon of deconfinement
is also of great interest, with studies of the temperature dependence of the
confining interaction reported recently. In the present work we study the
change of the properties of light mesons as the temperature is increased. For
this study we make use of a Nambu--Jona-Lasinio (NJL) model that has been
generalized to include a covariant model of confinement. The parameters of the
confining interaction are made temperature-dependent to take into account what
has been learned in lattice simulations of QCD at finite temperature. The
constituent quark masses are calculated at finite temperature using the NJL
model. A novel feature of our work is the introduction of a temperature
dependence of the NJL interaction parameters. (This is a purely
phenomenological feature of our model, which we do not attempt to derive from
more fundamental considerations.) With the three temperature-dependent aspects
of the model mentioned above, we find that the mesons we study are no longer
bound when the temperature reaches the critical temperature, $T_c$, which we
take to be 170 MeV. We believe that ours is the first model that is able to
describe the interplay of chiral symmetry restoration and deconfinement for
mesons at finite temperature. The introduction of temperature-dependent
coupling constants is a feature of our work whose further consequences should
be explored in future work.
| [
{
"created": "Thu, 12 Sep 2002 14:59:53 GMT",
"version": "v1"
},
{
"created": "Fri, 13 Sep 2002 13:31:48 GMT",
"version": "v2"
},
{
"created": "Mon, 28 Oct 2002 16:41:50 GMT",
"version": "v3"
}
] | 2007-05-23 | [
[
"Li",
"Hu",
""
],
[
"Shakin",
"C. M.",
""
]
] | There has been a great deal of interest in understanding the properties of quantum chromodynamics (QCD) for a finite value of the chemical potential and for finite temperature. Studies have been made of the restoration of chiral symmetry in matter and at finite temperature. The phenomenon of deconfinement is also of great interest, with studies of the temperature dependence of the confining interaction reported recently. In the present work we study the change of the properties of light mesons as the temperature is increased. For this study we make use of a Nambu--Jona-Lasinio (NJL) model that has been generalized to include a covariant model of confinement. The parameters of the confining interaction are made temperature-dependent to take into account what has been learned in lattice simulations of QCD at finite temperature. The constituent quark masses are calculated at finite temperature using the NJL model. A novel feature of our work is the introduction of a temperature dependence of the NJL interaction parameters. (This is a purely phenomenological feature of our model, which we do not attempt to derive from more fundamental considerations.) With the three temperature-dependent aspects of the model mentioned above, we find that the mesons we study are no longer bound when the temperature reaches the critical temperature, $T_c$, which we take to be 170 MeV. We believe that ours is the first model that is able to describe the interplay of chiral symmetry restoration and deconfinement for mesons at finite temperature. The introduction of temperature-dependent coupling constants is a feature of our work whose further consequences should be explored in future work. |
hep-ph/9702277 | Xiangdong Ji | Ian Balitsky and Xiangdong Ji | How Much of the Nucleon Spin is Carried by Glue? | replaced with a couple of reference added and spell-checked | Phys.Rev.Lett.79:1225-1228,1997 | 10.1103/PhysRevLett.79.1225 | JLAB-THY-97-05, U.ofMD PP#97-079, MIT-CTP-2607 | hep-ph | null | We estimate in the QCD sum rule approach the amount of the nucleon spin
carried by the gluon angular momentum: the sum of the gluon spin and orbital
angular momenta. The result indicates that gluons contribute at least one half
of the nucleon spin at scale of 1 GeV^2.
| [
{
"created": "Thu, 6 Feb 1997 19:22:49 GMT",
"version": "v1"
},
{
"created": "Mon, 10 Feb 1997 22:24:11 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"Balitsky",
"Ian",
""
],
[
"Ji",
"Xiangdong",
""
]
] | We estimate in the QCD sum rule approach the amount of the nucleon spin carried by the gluon angular momentum: the sum of the gluon spin and orbital angular momenta. The result indicates that gluons contribute at least one half of the nucleon spin at scale of 1 GeV^2. |
hep-ph/9406378 | null | S. Dittmaier, C. Grosse-Knetter and D. Schildknecht (University of
Bielefeld, Department of Theoretical Physics) | On the Role of the Higgs Mechanism in Present Electroweak Precision
Tests | 10 pages latex, BI-TP 94/31 | Z.Phys. C67 (1995) 109-114 | 10.1007/BF01564825 | null | hep-ph | null | Based on the observables $\MW$, $\Gamma_l$, $\bar\sw^2(\MZ^2)$, we evaluate
the parameters $\Delta x, \Delta y$ and $\varepsilon$ at one-loop level within
an electroweak massive vector-boson theory, which does not employ the Higgs
mechanism. The theoretical results are consistent with the experimental ones on
$\Delta x$, $\Delta y$, $\varepsilon$. The theoretical prediction for $\Delta
y$ coincides with the standard-model one (apart from numerically irrelevant
terms which vanish for $\MH\to\infty$). Non-renormalizability only affects
$\Delta x$ and $\varepsilon$, which differ from the standard-model results by
the replacement $\log\MH\to\log\Lambda$ for a heavy Higgs mass, $\MH$ (where
$\Lambda$ denotes an effective UV cut-off).
| [
{
"created": "Thu, 23 Jun 1994 14:14:07 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Dittmaier",
"S.",
"",
"University of\n Bielefeld, Department of Theoretical Physics"
],
[
"Grosse-Knetter",
"C.",
"",
"University of\n Bielefeld, Department of Theoretical Physics"
],
[
"Schildknecht",
"D.",
"",
"University of\n Bielefeld, Department of ... | Based on the observables $\MW$, $\Gamma_l$, $\bar\sw^2(\MZ^2)$, we evaluate the parameters $\Delta x, \Delta y$ and $\varepsilon$ at one-loop level within an electroweak massive vector-boson theory, which does not employ the Higgs mechanism. The theoretical results are consistent with the experimental ones on $\Delta x$, $\Delta y$, $\varepsilon$. The theoretical prediction for $\Delta y$ coincides with the standard-model one (apart from numerically irrelevant terms which vanish for $\MH\to\infty$). Non-renormalizability only affects $\Delta x$ and $\varepsilon$, which differ from the standard-model results by the replacement $\log\MH\to\log\Lambda$ for a heavy Higgs mass, $\MH$ (where $\Lambda$ denotes an effective UV cut-off). |
2008.03261 | Matthew Kirk | Matthew Kirk | Cabibbo anomaly versus electroweak precision tests: An exploration of
extensions of the Standard Model | v2: Add acknowledgements, improved discussion in Sections 2.1 and
6.1, small numerical updates to Table 3 and Figures 5 and 6, conclusions
unchanged. v3: results for L1 vector corrected due to bug in code, other
conclusions unchanged. v4: Journal version - discussion improvements in
introduction, secs. 2 and 3, improved analysis, plots, and discussion of
fermion BSM models to clarify viable models | Phys. Rev. D 103, 035004 (2021) | 10.1103/PhysRevD.103.035004 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | There is a newly emerging tension between determinations of $V_{us}$ from
different sources (known as the Cabibbo anomaly), which is clearly demonstrated
by the new $R(V_{us})$ observable. We explore this observable from the
perspective of the Standard Model Effective Field Theory and show there is a
discrepancy between $R(V_{us})$ and existing electroweak precision observables
(EWPO) in a simple single operator dominated scenario. We explore all possible
single particle extensions of the Standard Model that can generate the Cabibbo
anomaly effect and show how they cannot reconcile the current data. We further
examine the future of EWPO at the ILC or FCC-ee experiments and discuss the
effect on the tension of a change in specific EW observables.
| [
{
"created": "Fri, 7 Aug 2020 16:45:13 GMT",
"version": "v1"
},
{
"created": "Mon, 17 Aug 2020 16:18:48 GMT",
"version": "v2"
},
{
"created": "Tue, 8 Sep 2020 10:43:44 GMT",
"version": "v3"
},
{
"created": "Fri, 5 Feb 2021 12:45:25 GMT",
"version": "v4"
}
] | 2021-02-10 | [
[
"Kirk",
"Matthew",
""
]
] | There is a newly emerging tension between determinations of $V_{us}$ from different sources (known as the Cabibbo anomaly), which is clearly demonstrated by the new $R(V_{us})$ observable. We explore this observable from the perspective of the Standard Model Effective Field Theory and show there is a discrepancy between $R(V_{us})$ and existing electroweak precision observables (EWPO) in a simple single operator dominated scenario. We explore all possible single particle extensions of the Standard Model that can generate the Cabibbo anomaly effect and show how they cannot reconcile the current data. We further examine the future of EWPO at the ILC or FCC-ee experiments and discuss the effect on the tension of a change in specific EW observables. |
hep-ph/9604303 | null | M. Moretti | Four Fermions Productions at a $\gamma\gamma$ Collider | Plain Latex (10 pages) plus 8 postcript figures (NOT included in the
text and to be printed separately) | Nucl.Phys. B484 (1997) 3-16 | 10.1016/S0550-3213(96)00587-1 | null | hep-ph | null | Using the recently proposed ALPHA algorithm (and the resulting code) I
compute the rate (at tree level) for the process
$\gamma\gamma\rightarrow\bar\nu_e e^- u \bar d$. The bulk of the contribution
is due to W pair production and decay. However a non negligible ($\sim10 \%$)
contribution comes from other channels, mainly the production and decay of a W
and a collinear charged fermion. Requiring that the reconstructed invariant $u
\bar d$ mass lies in the intervals $M_W\pm 5 $ GeV and $M_W\pm 20 $ GeV one
obtains a rate which is lower, by 25 \% and 4 \% respectively, than the rate
obtained in the $narrow$ $width$ approximation, thus demonstrating the
relevance of the finite W width.
| [
{
"created": "Fri, 12 Apr 1996 07:56:03 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Moretti",
"M.",
""
]
] | Using the recently proposed ALPHA algorithm (and the resulting code) I compute the rate (at tree level) for the process $\gamma\gamma\rightarrow\bar\nu_e e^- u \bar d$. The bulk of the contribution is due to W pair production and decay. However a non negligible ($\sim10 \%$) contribution comes from other channels, mainly the production and decay of a W and a collinear charged fermion. Requiring that the reconstructed invariant $u \bar d$ mass lies in the intervals $M_W\pm 5 $ GeV and $M_W\pm 20 $ GeV one obtains a rate which is lower, by 25 \% and 4 \% respectively, than the rate obtained in the $narrow$ $width$ approximation, thus demonstrating the relevance of the finite W width. |
hep-ph/0506084 | Marek Karliner | Marek Karliner and Harry J. Lipkin | Isospin Analysis of pentaquark production forbids gamma p --> Theta^+
K_s and allows gamma n --> Theta^+ K^- | New version. Uses experimentally observed strong p/n asymmetry in
gamma N --> Lambda(1520) K to explain n/p asymmetry in gamma N --> Theta^+ K
and absence of gamma p --> Theta^+ K_s. Added microscopic derivation of
selection rule and unitarity argument that solves the K* problem. References
added and typos corrected | null | null | Cavendish-HEP-05/09, TAUP 2807/05, ANL-HEP-PR-05-47 | hep-ph | null | The discrepancy between Theta^+ photoproduction on proton vs. deuteron can be
resolved if the photon couples much more strongly to K^+K^- than to K0 K0bar as
indicated by the experimentally observed asymmetry between gamma p -->
Lambda(1520) K^+ and gamma n --> Lambda(1520) K_s. Significant
signal-background interference effects can occur in experiments like gamma N
--> Kbar Theta^+ which search for the Theta^+ as a narrow I=0 resonance in a
definite final state against a nonresonant background, with an experimental
resolution coarser than the expected resonance width. We show that when the
signal and background have roughly the same magnitude, destructive interference
can easily combine with a limited experimental resolution to completely destroy
the resonance signal. Whether or not this actually occurs depends critically on
the yet unknown relative phase of the I=0 and I=1 amplitudes. We discuss the
implications for some specific experiments.
| [
{
"created": "Wed, 8 Jun 2005 13:33:14 GMT",
"version": "v1"
},
{
"created": "Tue, 14 Jun 2005 21:32:02 GMT",
"version": "v2"
},
{
"created": "Thu, 16 Jun 2005 21:19:03 GMT",
"version": "v3"
}
] | 2007-05-23 | [
[
"Karliner",
"Marek",
""
],
[
"Lipkin",
"Harry J.",
""
]
] | The discrepancy between Theta^+ photoproduction on proton vs. deuteron can be resolved if the photon couples much more strongly to K^+K^- than to K0 K0bar as indicated by the experimentally observed asymmetry between gamma p --> Lambda(1520) K^+ and gamma n --> Lambda(1520) K_s. Significant signal-background interference effects can occur in experiments like gamma N --> Kbar Theta^+ which search for the Theta^+ as a narrow I=0 resonance in a definite final state against a nonresonant background, with an experimental resolution coarser than the expected resonance width. We show that when the signal and background have roughly the same magnitude, destructive interference can easily combine with a limited experimental resolution to completely destroy the resonance signal. Whether or not this actually occurs depends critically on the yet unknown relative phase of the I=0 and I=1 amplitudes. We discuss the implications for some specific experiments. |
1507.02809 | Takeo Moroi | Shinya Kanemura, Takeo Moroi, Tomohiko Tanabe | Beam Dump Experiment at Future Electron-Positron Colliders | 4 pages, 2 figures | null | 10.1016/j.physletb.2015.10.002 | UT-HET 102, UT-15-24 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose a new beam dump experiment at future colliders with electron
($e^-$) and positron ($e^+$) beams, BDee, which will provide a new possibility
to search for hidden particles, like hidden photon. If a particle detector is
installed behind the beam dump, it can detect the signal of in-flight decay of
the hidden particles produced by the scatterings of $e^\pm$ beams off materials
for dumping. We show that, compared to past experiments, BDee (in particular
BDee at $e^+e^-$ linear collider) significantly enlarges the parameter region
where the signal of the hidden particle can be discovered.
| [
{
"created": "Fri, 10 Jul 2015 08:56:48 GMT",
"version": "v1"
}
] | 2015-11-02 | [
[
"Kanemura",
"Shinya",
""
],
[
"Moroi",
"Takeo",
""
],
[
"Tanabe",
"Tomohiko",
""
]
] | We propose a new beam dump experiment at future colliders with electron ($e^-$) and positron ($e^+$) beams, BDee, which will provide a new possibility to search for hidden particles, like hidden photon. If a particle detector is installed behind the beam dump, it can detect the signal of in-flight decay of the hidden particles produced by the scatterings of $e^\pm$ beams off materials for dumping. We show that, compared to past experiments, BDee (in particular BDee at $e^+e^-$ linear collider) significantly enlarges the parameter region where the signal of the hidden particle can be discovered. |
2405.12277 | Joseph Bramante | Joseph Bramante and Nirmal Raj | Cosmology of self-replicating universes in black holes formed by dark
matter-seeded stellar collapse | 14 pages, 2 figures | null | null | null | hep-ph astro-ph.CO gr-qc | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We show that dark matter with certain minimal properties can convert the
majority of baryons in galaxies to black holes over hundred trillion year
timescales. We argue that this has implications for cosmologies which propose
that new universes are created in black hole interiors. We focus on the
paradigm of cosmological natural selection, which connects black hole
production to a universe's likelihood for existing. Further, we propose that
the universe's timescale for entropy production could be dynamically linked to
black hole production in a naturally selected universe. Our universe would fit
this scenario for models of particle dark matter that convert helium white
dwarfs to black holes in around a hundred trillion years, where the dominant
source of entropy in our universe are the helium white dwarfs' stellar
progenitors, which cease forming and burning also in around a hundred trillion
years. Much of this dark matter could be discovered at ongoing experiments.
| [
{
"created": "Mon, 20 May 2024 18:00:01 GMT",
"version": "v1"
}
] | 2024-05-22 | [
[
"Bramante",
"Joseph",
""
],
[
"Raj",
"Nirmal",
""
]
] | We show that dark matter with certain minimal properties can convert the majority of baryons in galaxies to black holes over hundred trillion year timescales. We argue that this has implications for cosmologies which propose that new universes are created in black hole interiors. We focus on the paradigm of cosmological natural selection, which connects black hole production to a universe's likelihood for existing. Further, we propose that the universe's timescale for entropy production could be dynamically linked to black hole production in a naturally selected universe. Our universe would fit this scenario for models of particle dark matter that convert helium white dwarfs to black holes in around a hundred trillion years, where the dominant source of entropy in our universe are the helium white dwarfs' stellar progenitors, which cease forming and burning also in around a hundred trillion years. Much of this dark matter could be discovered at ongoing experiments. |
hep-ph/9702367 | shunzo Kumano | S. Kumano (Saga Univ./ Univ. of Washington) | Flavor Asymmetry of Antiquark Distributions in the Nucleon | 3+79 pages, LATEX2e, 29 eps figures. Physics Reports in press.
Complete postscript file is available at
http://www.cc.saga-u.ac.jp/saga-u/riko/physics/quantum1/structure.html Email:
kumanos@cc.saga-u.ac.jp | Phys.Rept.303:183-257,1998 | 10.1016/S0370-1573(98)00016-7 | SAGA-HE-97-97; DOE/ER/40561-255-INT96-19-01 | hep-ph hep-ex nucl-ex nucl-th | null | 1. Introduction
2. Possible violation of the Gottfried sum rule
2.1 Gottfried sum rule 2.2 Early experimental results 2.3 NMC finding and
recent progress 2.4 Small $x$ contribution 2.5 Nuclear correction: shadowing in
the deuteron 2.6 Parametrization of antiquark distributions
3 Expectations in perturbative QCD
3.1 Operator product expansion 3.2 Perturbative correction to the Gottfried
sum
4 Theoretical ideas for the sum-rule violation
4.1 Lattice QCD 4.2 Pauli exclusion principle 4.3 Mesonic models 4.3.1
Meson-cloud contribution 4.3.2 Chiral models 4.3.3 Anomalous $Q^2$ evolution
4.4 Diquark model 4.5 Isospin symmetry violation 4.6 Flavor asymmetry ubar-dbar
in nuclei 4.7 Relation to nucleon spin 4.8 Comment on effects of quark mass and
transverse motion
5 Finding the flavor asymmetry ubar-dbar in various processes
5.1 Drell-Yan process 5.1.1 Fermilab-E866 results 5.2 W and Z production 5.3
Quarkonium production at large $x_{_F}$ 5.4 Charged hadron production 5.5
Neutrino scattering 5.6 Experiments to find isospin symmetry violation
6 Related topics on antiquark distributions
7 Summary and outlook
| [
{
"created": "Wed, 19 Feb 1997 06:25:18 GMT",
"version": "v1"
},
{
"created": "Wed, 28 Jan 1998 08:40:09 GMT",
"version": "v2"
}
] | 2011-07-19 | [
[
"Kumano",
"S.",
"",
"Saga Univ./ Univ. of Washington"
]
] | 1. Introduction 2. Possible violation of the Gottfried sum rule 2.1 Gottfried sum rule 2.2 Early experimental results 2.3 NMC finding and recent progress 2.4 Small $x$ contribution 2.5 Nuclear correction: shadowing in the deuteron 2.6 Parametrization of antiquark distributions 3 Expectations in perturbative QCD 3.1 Operator product expansion 3.2 Perturbative correction to the Gottfried sum 4 Theoretical ideas for the sum-rule violation 4.1 Lattice QCD 4.2 Pauli exclusion principle 4.3 Mesonic models 4.3.1 Meson-cloud contribution 4.3.2 Chiral models 4.3.3 Anomalous $Q^2$ evolution 4.4 Diquark model 4.5 Isospin symmetry violation 4.6 Flavor asymmetry ubar-dbar in nuclei 4.7 Relation to nucleon spin 4.8 Comment on effects of quark mass and transverse motion 5 Finding the flavor asymmetry ubar-dbar in various processes 5.1 Drell-Yan process 5.1.1 Fermilab-E866 results 5.2 W and Z production 5.3 Quarkonium production at large $x_{_F}$ 5.4 Charged hadron production 5.5 Neutrino scattering 5.6 Experiments to find isospin symmetry violation 6 Related topics on antiquark distributions 7 Summary and outlook |
1009.5967 | Ethan Neil | Thomas Appelquist, Ron Babich, Richard C. Brower, Michael Cheng,
Michael A. Clark, Saul D. Cohen, George T. Fleming, Joe Kiskis, Meifeng Lin,
Ethan T. Neil, James C. Osborn, Claudio Rebbi, David Schaich, Pavlos Vranas | Parity Doubling and the S Parameter Below the Conformal Window | 4 pages, 5 figures; to be submitted to PRL | Phys.Rev.Lett.106:231601,2011 | 10.1103/PhysRevLett.106.231601 | null | hep-ph hep-lat | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We describe a lattice simulation of the masses and decay constants of the
lowest-lying vector and axial resonances, and the electroweak S parameter, in
an SU(3) gauge theory with $N_f = 2$ and 6 fermions in the fundamental
representation. The spectrum becomes more parity doubled and the S parameter
per electroweak doublet decreases when $N_f$ is increased from 2 to 6,
motivating study of these trends as $N_f$ is increased further, toward the
critical value for transition from confinement to infrared conformality.
| [
{
"created": "Wed, 29 Sep 2010 18:20:11 GMT",
"version": "v1"
}
] | 2011-07-25 | [
[
"Appelquist",
"Thomas",
""
],
[
"Babich",
"Ron",
""
],
[
"Brower",
"Richard C.",
""
],
[
"Cheng",
"Michael",
""
],
[
"Clark",
"Michael A.",
""
],
[
"Cohen",
"Saul D.",
""
],
[
"Fleming",
"George T.",
""
]... | We describe a lattice simulation of the masses and decay constants of the lowest-lying vector and axial resonances, and the electroweak S parameter, in an SU(3) gauge theory with $N_f = 2$ and 6 fermions in the fundamental representation. The spectrum becomes more parity doubled and the S parameter per electroweak doublet decreases when $N_f$ is increased from 2 to 6, motivating study of these trends as $N_f$ is increased further, toward the critical value for transition from confinement to infrared conformality. |
hep-ph/9602364 | null | Christopher D. Carone (LBNL), Lawrence J. Hall and Hitoshi Murayama
(LBNL and UC Berkeley) | A Supersymmetric Theory of Flavor and R Parity | 28 pp. LaTeX, 1 Postscript Figure | Phys.Rev.D54:2328-2339,1996 | 10.1103/PhysRevD.54.2328 | LBL-38380, UCB-PTH-96/06 | hep-ph | null | We construct a renormalizable, supersymmetric theory of flavor and $R$ parity
based on the discrete flavor group $(S_3)^3$. The model can account for all the
masses and mixing angles of the Standard Model, while maintaining sufficient
squark degeneracy to circumvent the supersymmetric flavor problem. By starting
with a simpler set of flavor symmetry breaking fields than we have suggested
previously, we construct an economical Froggatt-Nielsen sector that generates
the desired elements of the fermion Yukawa matrices. With the particle content
above the flavor scale completely specified, we show that all renormalizable
$R$-parity-violating interactions involving the ordinary matter fields are
forbidden by the flavor symmetry. Thus, $R$ parity arises as an accidental
symmetry in our model. Planck-suppressed operators that violate $R$ parity, if
present, can be rendered harmless by taking the flavor scale to be $\lesssim 8
\times 10^{10}$ GeV.
| [
{
"created": "Thu, 22 Feb 1996 03:30:33 GMT",
"version": "v1"
}
] | 2009-09-29 | [
[
"Carone",
"Christopher D.",
"",
"LBNL"
],
[
"Hall",
"Lawrence J.",
"",
"LBNL and UC Berkeley"
],
[
"Murayama",
"Hitoshi",
"",
"LBNL and UC Berkeley"
]
] | We construct a renormalizable, supersymmetric theory of flavor and $R$ parity based on the discrete flavor group $(S_3)^3$. The model can account for all the masses and mixing angles of the Standard Model, while maintaining sufficient squark degeneracy to circumvent the supersymmetric flavor problem. By starting with a simpler set of flavor symmetry breaking fields than we have suggested previously, we construct an economical Froggatt-Nielsen sector that generates the desired elements of the fermion Yukawa matrices. With the particle content above the flavor scale completely specified, we show that all renormalizable $R$-parity-violating interactions involving the ordinary matter fields are forbidden by the flavor symmetry. Thus, $R$ parity arises as an accidental symmetry in our model. Planck-suppressed operators that violate $R$ parity, if present, can be rendered harmless by taking the flavor scale to be $\lesssim 8 \times 10^{10}$ GeV. |
1403.5027 | Farinaldo Queiroz | Alexandre Alves, Stefano Profumo, Farinaldo S. Queiroz, William
Shepherd | The Effective Hooperon | 13 pages, 2 Figures. Published in Phys. Rev. D with the
Title:Effective field theory approach to the Galactic Center gamma-ray excess | Phys. Rev. D 90, 115003 (2014) | 10.1103/PhysRevD.90.115003 | null | hep-ph astro-ph.HE hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We explore the possibility of explaining a gamma-ray excess in the Galactic
Center, originally pointed out by Hooper, collaborators, and other groups, in
an effective field theory framework. We assume that dark matter annihilation is
mediated by particles heavy enough to be integrated out, and that such
particles couple to all quark families. We calculate the effective coupling
required to explain the annihilation signal in the Galactic Center, and compare
with bounds from direct detection, collider searches, and the requirement that
the dark matter particle make up the appropriate fraction of the universal
energy budget. We find that only a very small set of operators can explain the
gamma-ray excess while being consistent with other constraints. Specifically,
for scalar dark matter the viable options are one scalar-type coupling to
quarks and one interaction with gluons, while for fermionic (Dirac) dark matter
the viable options are two scalar-type dimension-7 operators or a dimension-6
vector-type operator. In all cases, future searches with the Large Hadron
Collider should probe the relevant operators' effective energy scale, while all
viable interactions should escape direct detection experiments.
| [
{
"created": "Thu, 20 Mar 2014 02:26:18 GMT",
"version": "v1"
},
{
"created": "Fri, 14 Nov 2014 19:47:45 GMT",
"version": "v2"
}
] | 2014-12-10 | [
[
"Alves",
"Alexandre",
""
],
[
"Profumo",
"Stefano",
""
],
[
"Queiroz",
"Farinaldo S.",
""
],
[
"Shepherd",
"William",
""
]
] | We explore the possibility of explaining a gamma-ray excess in the Galactic Center, originally pointed out by Hooper, collaborators, and other groups, in an effective field theory framework. We assume that dark matter annihilation is mediated by particles heavy enough to be integrated out, and that such particles couple to all quark families. We calculate the effective coupling required to explain the annihilation signal in the Galactic Center, and compare with bounds from direct detection, collider searches, and the requirement that the dark matter particle make up the appropriate fraction of the universal energy budget. We find that only a very small set of operators can explain the gamma-ray excess while being consistent with other constraints. Specifically, for scalar dark matter the viable options are one scalar-type coupling to quarks and one interaction with gluons, while for fermionic (Dirac) dark matter the viable options are two scalar-type dimension-7 operators or a dimension-6 vector-type operator. In all cases, future searches with the Large Hadron Collider should probe the relevant operators' effective energy scale, while all viable interactions should escape direct detection experiments. |
1305.2374 | Naoki Machida | Naoki Machida | Vacuum stability of supersymmetric extended Higgs sectors with a
discrete symmetry | References added, 5 pages, 2 figures, prepared for Proceedings of
Toyama International Workshop on "Higgs as a Probe of New Physics 2013
(HPNP2013)", 13-16, February, 2013 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study vacuum stability of supersymmetric extended Higgs sectors with a
discrete $Z_2$ symmetry. These models may be able to explain dark matter,
neutrino masses, baryon asymmetry of the Universe and hierarchy problem
simultaneously at the TeV scale. This $Z_2$ symmetry could be broken
spontaneously. We examine the stability of the $Z_2$ symmetric vacuum at the
tree level in several models with such extended Higgs sectors.
| [
{
"created": "Fri, 10 May 2013 15:49:35 GMT",
"version": "v1"
},
{
"created": "Mon, 27 May 2013 13:34:24 GMT",
"version": "v2"
}
] | 2013-05-28 | [
[
"Machida",
"Naoki",
""
]
] | We study vacuum stability of supersymmetric extended Higgs sectors with a discrete $Z_2$ symmetry. These models may be able to explain dark matter, neutrino masses, baryon asymmetry of the Universe and hierarchy problem simultaneously at the TeV scale. This $Z_2$ symmetry could be broken spontaneously. We examine the stability of the $Z_2$ symmetric vacuum at the tree level in several models with such extended Higgs sectors. |
0907.0525 | Yosuke Takubo | Yosuke Takubo, Eri Asakawa, Masaki Asano, Keisuke Fujii, Tomonori
Kusano, Shigeki Matsumoto, Rei Sasaki, and Hitoshi Yamamoto | Measurement of Heavy Gauge Bosons in Little Higgs Model with T-parity at
ILC | 7 pages, 4 figures, Proceedings of the 8th general meeting of the ILC
physics working group, 1/21, 2009 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The Littlest Higgs Model with T-parity is one of the attractive candidates of
physics beyond the Standard Model. One of the important predictions of the
model is the existence of new heavy gauge bosons, where they acquire mass terms
through the breaking of global symmetry necessarily imposed on the model. The
determination of the masses are, hence, quite important to test the model. In
this paper, the measurement accuracy of the heavy gauge bosons at ILC is
eported.
| [
{
"created": "Fri, 3 Jul 2009 03:25:43 GMT",
"version": "v1"
}
] | 2009-07-06 | [
[
"Takubo",
"Yosuke",
""
],
[
"Asakawa",
"Eri",
""
],
[
"Asano",
"Masaki",
""
],
[
"Fujii",
"Keisuke",
""
],
[
"Kusano",
"Tomonori",
""
],
[
"Matsumoto",
"Shigeki",
""
],
[
"Sasaki",
"Rei",
""
],
[
"Y... | The Littlest Higgs Model with T-parity is one of the attractive candidates of physics beyond the Standard Model. One of the important predictions of the model is the existence of new heavy gauge bosons, where they acquire mass terms through the breaking of global symmetry necessarily imposed on the model. The determination of the masses are, hence, quite important to test the model. In this paper, the measurement accuracy of the heavy gauge bosons at ILC is eported. |
hep-ph/0105345 | Felice Pisano | F. Pisano and N.O. Reis | Cosmological constant and spontaneous gauge symmetry breaking: the
particle physics and cosmology interface charade | 22 pages | null | null | null | hep-ph | null | We describe one of the remarkable problems of theoretical physics persevering
up to the beginning of the millennium. All gaugetheories with spontaneous gauge
symmetry breaking from the standard model of particle physics with the
electroweak symmetry breaking at the Fermi scale, 246 GeV, up to strings,
supergravity, and the M(embrane)-theory superunification with symmetry breaking
starting near the Planck scale, $10^{19}$ GeV, foresee that the spontaneous
symmetry breakings induce a vacuum energy at least 50 orders of magnitude
larger than the stringent experimental bound $G\Lambda\lesssim 10^{-122}$ on
the value of the cosmological constant $\Lambda$. This fact seems to have a
universal character since it occurs from the Fermi scale up to the Planck one.
It is the vacuum catastrophe.
| [
{
"created": "Thu, 31 May 2001 18:29:20 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Pisano",
"F.",
""
],
[
"Reis",
"N. O.",
""
]
] | We describe one of the remarkable problems of theoretical physics persevering up to the beginning of the millennium. All gaugetheories with spontaneous gauge symmetry breaking from the standard model of particle physics with the electroweak symmetry breaking at the Fermi scale, 246 GeV, up to strings, supergravity, and the M(embrane)-theory superunification with symmetry breaking starting near the Planck scale, $10^{19}$ GeV, foresee that the spontaneous symmetry breakings induce a vacuum energy at least 50 orders of magnitude larger than the stringent experimental bound $G\Lambda\lesssim 10^{-122}$ on the value of the cosmological constant $\Lambda$. This fact seems to have a universal character since it occurs from the Fermi scale up to the Planck one. It is the vacuum catastrophe. |
1812.10238 | Arpan Das | Aman Abhishek, Arpan Das, Hiranmaya Mishra, Ranjita K. Mohapatra | Spin Polarization and Chiral Condensation in 2+1 flavor
Nambu-Jona-Lasinio model at finite temperature and baryon chemical potential | 21 pages, 10 figures | Phys. Rev. D 100, 114012 (2019) | 10.1103/PhysRevD.100.114012 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the ferromagnetic (spin polarization) condensation in (2+1)
flavor Nambu Jona-Lasinio(NJL) model with non-zero current quark masses at
finite temperature and density which may be relevant in the context of neutron
stars. The spin polarization condensation arises due to a tensor type
interaction which may be generated due to non-perturbative effects in Quantum
Chromodynamics(QCD). In this investigation we have shown the interplay between
chiral condensate and spin polarization condensation for different values of
tensor coupling. Spin polarization in the case of 2+1 flavor is different from
two flavor case because of additional F$_8$ condensate associated with
$\lambda_8^f$ flavor generator. We find a non-zero value of the two spin
condensates in the chirally restored phase. Beyond a certain temperature the
spin polarization condensates vanish for rather large quark chemical
potentials. The spin condensates affect the chiral phase transition, quark
masses, and the quark dispersion relation. The spin polarization condensate
appears only in the chiral restored phase for light quarks. For large enough
tensor couplings, it is observed that the spin polarization condensate acts as
a catalyst for chiral symmetry restoration. Thermodynamic behavior of $F_3$ and
$F_8$ are found to be different and they affect the quark masses differently.
| [
{
"created": "Wed, 26 Dec 2018 06:16:59 GMT",
"version": "v1"
}
] | 2019-12-11 | [
[
"Abhishek",
"Aman",
""
],
[
"Das",
"Arpan",
""
],
[
"Mishra",
"Hiranmaya",
""
],
[
"Mohapatra",
"Ranjita K.",
""
]
] | We investigate the ferromagnetic (spin polarization) condensation in (2+1) flavor Nambu Jona-Lasinio(NJL) model with non-zero current quark masses at finite temperature and density which may be relevant in the context of neutron stars. The spin polarization condensation arises due to a tensor type interaction which may be generated due to non-perturbative effects in Quantum Chromodynamics(QCD). In this investigation we have shown the interplay between chiral condensate and spin polarization condensation for different values of tensor coupling. Spin polarization in the case of 2+1 flavor is different from two flavor case because of additional F$_8$ condensate associated with $\lambda_8^f$ flavor generator. We find a non-zero value of the two spin condensates in the chirally restored phase. Beyond a certain temperature the spin polarization condensates vanish for rather large quark chemical potentials. The spin condensates affect the chiral phase transition, quark masses, and the quark dispersion relation. The spin polarization condensate appears only in the chiral restored phase for light quarks. For large enough tensor couplings, it is observed that the spin polarization condensate acts as a catalyst for chiral symmetry restoration. Thermodynamic behavior of $F_3$ and $F_8$ are found to be different and they affect the quark masses differently. |
hep-ph/0509074 | Cyrille Marquet | C. Marquet, R. Peschanski and G. Soyez | QCD traveling waves at non-asymptotic energies | 10 pages, 5 figures, minor revision, version to appear in PLB | Phys.Lett.B628:239-249,2005 | 10.1016/j.physletb.2005.09.035 | null | hep-ph | null | Using consistent truncations of the BFKL kernel, we derive analytical
traveling-wave solutions of the Balitsky-Kovchegov saturation equation for both
fixed and running coupling. A universal parametrization of the ``interior'' of
the wave front is obtained and compares well with numerical simulations of the
original Balitsky-Kovchegov equation, even at non-asymptotic energies. Using
this universal parametrization, we find evidence for a traveling-wave pattern
of the dipole amplitude determined from the gluon distribution extracted from
deep inelastic scattering data.
| [
{
"created": "Thu, 8 Sep 2005 09:26:31 GMT",
"version": "v1"
},
{
"created": "Mon, 3 Oct 2005 13:10:49 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Marquet",
"C.",
""
],
[
"Peschanski",
"R.",
""
],
[
"Soyez",
"G.",
""
]
] | Using consistent truncations of the BFKL kernel, we derive analytical traveling-wave solutions of the Balitsky-Kovchegov saturation equation for both fixed and running coupling. A universal parametrization of the ``interior'' of the wave front is obtained and compares well with numerical simulations of the original Balitsky-Kovchegov equation, even at non-asymptotic energies. Using this universal parametrization, we find evidence for a traveling-wave pattern of the dipole amplitude determined from the gluon distribution extracted from deep inelastic scattering data. |
hep-ph/0305189 | Peter Petreczky | Peter Petreczky | Lattice calculations of meson correlators and spectral functions at
finite temperature | Invited plenary talk presented at SQM03 (Atlantic Beach, March 12-17,
2003), 10 pages LaTeX, uses iopams.sty, iopart.cls | J.Phys. G30 (2004) S431-S440 | 10.1088/0954-3899/30/1/051 | null | hep-ph hep-lat | null | I review recent progress in relating meson spectral function to imaginary
time correlation function at finite temperature calculated on isotropic as well
as on anisotropic lattices. Special attention is payed for the lattice
artifacts present in calculation of meson spectral functions. Results in the
case of light quarks as well as heavy quarks are reviewed which indicate in
particular that even in the chiral limit meson spectral functions have
non-trivial structure and the ground state quarkonia survive up to temperature
1.5T_c
| [
{
"created": "Fri, 16 May 2003 23:00:15 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Petreczky",
"Peter",
""
]
] | I review recent progress in relating meson spectral function to imaginary time correlation function at finite temperature calculated on isotropic as well as on anisotropic lattices. Special attention is payed for the lattice artifacts present in calculation of meson spectral functions. Results in the case of light quarks as well as heavy quarks are reviewed which indicate in particular that even in the chiral limit meson spectral functions have non-trivial structure and the ground state quarkonia survive up to temperature 1.5T_c |
hep-ph/9911430 | Kenichiro Aoki | Kenichiro Aoki and Dimitri Kusnezov | Classical $\phi^4$ Lattice Field Theory in Strong Thermal Gradients | 4pp, 4 figs, Talk given by K.A. at the Thermal Field Theory
Conference, Kyoto, August 1999 | null | null | null | hep-ph | null | The dynamics of classical $\phi^4$ theory under weak and strong thermal
gradients is studied. We obtain the thermal conductivity of the theory
including its temperature dependence. Under moderately strong thermal
gradients, the temperature profiles become visibly non-linear, yet the
phenomenon can be understood using the linear response theory. When we move
further away from equilibrium, we find that the linear response theory
eventually breaks down, and the concept of local equilibrium also fails.
| [
{
"created": "Mon, 22 Nov 1999 01:43:15 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Aoki",
"Kenichiro",
""
],
[
"Kusnezov",
"Dimitri",
""
]
] | The dynamics of classical $\phi^4$ theory under weak and strong thermal gradients is studied. We obtain the thermal conductivity of the theory including its temperature dependence. Under moderately strong thermal gradients, the temperature profiles become visibly non-linear, yet the phenomenon can be understood using the linear response theory. When we move further away from equilibrium, we find that the linear response theory eventually breaks down, and the concept of local equilibrium also fails. |
1702.05484 | Prateek Agrawal | Prateek Agrawal, JiJi Fan, Matthew Reece and Wei Xue | Deciphering the MSSM Higgs Mass at Future Hadron Colliders | 19 pages, 13 figures | null | 10.1007/JHEP06(2017)027 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Future hadron colliders will have a remarkable capacity to discover massive
new particles, but their capabilities for precision measurements of couplings
that can reveal underlying mechanisms have received less study. In this work we
study the capability of future hadron colliders to shed light on a precise,
focused question: is the higgs mass of 125 GeV explained by the MSSM? If
supersymmetry is realized near the TeV scale, a future hadron collider could
produce huge numbers of gluinos and electroweakinos. We explore whether
precision measurements of their properties could allow inference of the scalar
masses and $\tan \beta$ with sufficient accuracy to test whether physics beyond
the MSSM is needed to explain the higgs mass. We also discuss dark matter
direct detection and precision higgs physics as complementary probes of $\tan
\beta$. For concreteness, we focus on the mini-split regime of MSSM parameter
space at a 100 TeV $pp$ collider, with scalar masses ranging from 10s to about
1000 TeV.
| [
{
"created": "Fri, 17 Feb 2017 19:00:00 GMT",
"version": "v1"
}
] | 2017-06-28 | [
[
"Agrawal",
"Prateek",
""
],
[
"Fan",
"JiJi",
""
],
[
"Reece",
"Matthew",
""
],
[
"Xue",
"Wei",
""
]
] | Future hadron colliders will have a remarkable capacity to discover massive new particles, but their capabilities for precision measurements of couplings that can reveal underlying mechanisms have received less study. In this work we study the capability of future hadron colliders to shed light on a precise, focused question: is the higgs mass of 125 GeV explained by the MSSM? If supersymmetry is realized near the TeV scale, a future hadron collider could produce huge numbers of gluinos and electroweakinos. We explore whether precision measurements of their properties could allow inference of the scalar masses and $\tan \beta$ with sufficient accuracy to test whether physics beyond the MSSM is needed to explain the higgs mass. We also discuss dark matter direct detection and precision higgs physics as complementary probes of $\tan \beta$. For concreteness, we focus on the mini-split regime of MSSM parameter space at a 100 TeV $pp$ collider, with scalar masses ranging from 10s to about 1000 TeV. |
hep-ph/0605142 | Per Osland | Abdul Wahab El Kaffas, Wafaa Khater, Odd Magne Ogreid, Per Osland | Consistency of the Two Higgs Doublet Model and CP violation in top
production at the LHC | 45 pages, 10 figures, some in (essential) colour. Figures 2, 6 and 7
are bitmapped, better quality available on request. Version to appear in
Nucl. Phys. B | Nucl.Phys.B775:45-77,2007 | 10.1016/j.nuclphysb.2007.03.041 | null | hep-ph | null | It is important to provide guidance on whether CP violation may be measurable
in top-quark production at the Large Hadron Collider. The present work extends
an earlier analysis of the non-supersymmetric Two-Higgs-Doublet Model in this
respect, by allowing a more general potential. Also, a more comprehensive study
of theoretical and experimental constraints on the model is presented. Vacuum
stability, unitarity, direct searches and electroweak precision measurements
severely constrain the model. We explore, at low \tan\beta, the allowed regions
in the multidimensional parameter space that give a viable physical model. This
exploration is focused on the parameter space of the neutral sector rotation
matrix, which is closely related to the Yukawa couplings of interest. In most
of the remaining allowed regions, the model violates CP. We present a
quantitative discussion of a particular CP-violating observable. This would be
measurable in semileptonically decaying top and antitop quarks produced at the
LHC, provided the number of available events is of the order of a million.
| [
{
"created": "Fri, 12 May 2006 05:58:11 GMT",
"version": "v1"
},
{
"created": "Wed, 9 May 2007 06:32:32 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Kaffas",
"Abdul Wahab El",
""
],
[
"Khater",
"Wafaa",
""
],
[
"Ogreid",
"Odd Magne",
""
],
[
"Osland",
"Per",
""
]
] | It is important to provide guidance on whether CP violation may be measurable in top-quark production at the Large Hadron Collider. The present work extends an earlier analysis of the non-supersymmetric Two-Higgs-Doublet Model in this respect, by allowing a more general potential. Also, a more comprehensive study of theoretical and experimental constraints on the model is presented. Vacuum stability, unitarity, direct searches and electroweak precision measurements severely constrain the model. We explore, at low \tan\beta, the allowed regions in the multidimensional parameter space that give a viable physical model. This exploration is focused on the parameter space of the neutral sector rotation matrix, which is closely related to the Yukawa couplings of interest. In most of the remaining allowed regions, the model violates CP. We present a quantitative discussion of a particular CP-violating observable. This would be measurable in semileptonically decaying top and antitop quarks produced at the LHC, provided the number of available events is of the order of a million. |
1505.00994 | Benjamin Nachman | Benjamin Nachman | Less is More when Gluinos Mediate | null | Mod. Phys. Lett. A, 31, 1650052 (2016) | 10.1142/S0217732316500528 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Compressed mass spectra are generally more difficult to identify than spectra
with large splittings. In particular, gluino pair production with four high
energy top or bottom quarks leaves a striking signature in a detector. However,
if any of the mass splittings are compressed, the power of traditional
techniques may deteriorate. Searches for direct stop/sbottom pair production
can fill in the gaps. As a demonstration, we show that for
$\tilde{g}\rightarrow t\tilde{t}_1$ and $m_{\tilde{t}_1}\sim
m_{\tilde{\chi}_1^0}$, limits on the stop mass at 8 TeV can be extended by
least 300 GeV for a 1.1 TeV gluino using a $pp\rightarrow
\tilde{t}_1\tilde{t}_1$ search. At 13 TeV, the effective cross section for the
gluino mediated process is twice the direct stop/sbottom pair production cross
section, suggesting that direct stop/sbottom searches could be sensitive to
discover new physics earlier than expected.
| [
{
"created": "Tue, 5 May 2015 13:05:38 GMT",
"version": "v1"
}
] | 2016-09-06 | [
[
"Nachman",
"Benjamin",
""
]
] | Compressed mass spectra are generally more difficult to identify than spectra with large splittings. In particular, gluino pair production with four high energy top or bottom quarks leaves a striking signature in a detector. However, if any of the mass splittings are compressed, the power of traditional techniques may deteriorate. Searches for direct stop/sbottom pair production can fill in the gaps. As a demonstration, we show that for $\tilde{g}\rightarrow t\tilde{t}_1$ and $m_{\tilde{t}_1}\sim m_{\tilde{\chi}_1^0}$, limits on the stop mass at 8 TeV can be extended by least 300 GeV for a 1.1 TeV gluino using a $pp\rightarrow \tilde{t}_1\tilde{t}_1$ search. At 13 TeV, the effective cross section for the gluino mediated process is twice the direct stop/sbottom pair production cross section, suggesting that direct stop/sbottom searches could be sensitive to discover new physics earlier than expected. |
1612.05816 | Sanjin Beni\'c | Sanjin Benic, Kenji Fukushima, Oscar Garcia-Montero, Raju Venugopalan | Photons from the Color Glass Condensate in p+A collisions | Hard Probes 2016 proceedings contribution, Sep. 23-27, Wuhan, China.
4 pages, 3 figures | null | 10.1051/epjconf/201714104004 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We report on a first NLO computation of photon production in p+A collisions
at collider energies within the Color Glass Condensate framework, significantly
extending previous LO results. At central rapidites, our result is the dominant
contribution and probes multi-gluon correlators in nuclei. At high photon
momenta, the result is directly sensitive to the nuclear gluon distribution.
The NLO result contains two processes, the annihilation process and the process
with $q\bar{q}$ pair and a photon in the final state. We provide a numerical
evaluation of the photon spectrum from the annihilation process.
| [
{
"created": "Sat, 17 Dec 2016 19:53:07 GMT",
"version": "v1"
}
] | 2017-04-26 | [
[
"Benic",
"Sanjin",
""
],
[
"Fukushima",
"Kenji",
""
],
[
"Garcia-Montero",
"Oscar",
""
],
[
"Venugopalan",
"Raju",
""
]
] | We report on a first NLO computation of photon production in p+A collisions at collider energies within the Color Glass Condensate framework, significantly extending previous LO results. At central rapidites, our result is the dominant contribution and probes multi-gluon correlators in nuclei. At high photon momenta, the result is directly sensitive to the nuclear gluon distribution. The NLO result contains two processes, the annihilation process and the process with $q\bar{q}$ pair and a photon in the final state. We provide a numerical evaluation of the photon spectrum from the annihilation process. |
1402.0164 | G.R. Boroun | G.R.Boroun and B.Rezaei | Decoupling of the DGLAP evolution equations at next-to-next-to-leading
order (NNLO) at low-x | 8 pages,2 figures | Eur. Phys. J. C (2013) 73:2412 | 10.1140/s10052-013-2412-z | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a set of formulas to extract two second-order independent
differential equations for the gluon and singlet distribution functions. Our
results extend from the LO up to NNLO DGLAP evolution equations with respect to
the hard-Pomeron behavior at low-x. In this approach, both singlet quarks and
gluons have the same high-energy behavior at low-x. We solve the independent
DGLAP evolution equations for the functions $F^{s}_{2}(x,Q^{2})$ and
$G(x,Q^{2})$ as a function of their initial parameterization at the starting
scale $Q^{2}_{0}$ . The results not only give striking support to the
hard-Pomeron description of the low-x behavior, but give a rather clean test of
perturbative QCD showing an increase of the gluon distribution and singlet
structure functions as x decreases. We compared our numerical results with the
published BDM (Block et al. Phys. Rev. D 77:094003 (2008)) gluon and singlet
distributions, starting from their initial values at $Q^{2}_{0} =1 GeV^{2}$.
| [
{
"created": "Sun, 2 Feb 2014 09:42:33 GMT",
"version": "v1"
}
] | 2014-02-04 | [
[
"Boroun",
"G. R.",
""
],
[
"Rezaei",
"B.",
""
]
] | We present a set of formulas to extract two second-order independent differential equations for the gluon and singlet distribution functions. Our results extend from the LO up to NNLO DGLAP evolution equations with respect to the hard-Pomeron behavior at low-x. In this approach, both singlet quarks and gluons have the same high-energy behavior at low-x. We solve the independent DGLAP evolution equations for the functions $F^{s}_{2}(x,Q^{2})$ and $G(x,Q^{2})$ as a function of their initial parameterization at the starting scale $Q^{2}_{0}$ . The results not only give striking support to the hard-Pomeron description of the low-x behavior, but give a rather clean test of perturbative QCD showing an increase of the gluon distribution and singlet structure functions as x decreases. We compared our numerical results with the published BDM (Block et al. Phys. Rev. D 77:094003 (2008)) gluon and singlet distributions, starting from their initial values at $Q^{2}_{0} =1 GeV^{2}$. |
hep-ph/0403115 | Haim Goldberg | Luis Anchordoqui, Haim Goldberg and Pran Nath | Probing mSUGRA via the Extreme Universe Space Observatory | Some discussion added, final version to be published in Physical
Review D | Phys.Rev. D70 (2004) 025014 | 10.1103/PhysRevD.70.025014 | NUB-3247/Th-04 | hep-ph astro-ph hep-th | null | An analysis is carried out within mSUGRA of the estimated number of events
originating from upward moving ultra-high energy neutralinos that could be
detected by the Extreme Universe Space Observatory (EUSO). The analysis
exploits a recently proposed technique that differentiates ultra-high energy
neutralinos from ultra-high energy neutrinos using their different absorption
lengths in the Earth's crust. It is shown that for a significant part of the
parameter space, where the neutralino is mostly a Bino and with squark mass
$\sim 1$ TeV, EUSO could see ultra-high energy neutralino events with
essentially no background. In the energy range 10^9 GeV < E < 10^11 GeV, the
unprecedented aperture of EUSO makes the telescope sensitive to neutralino
fluxes as low as 1.1 \times 10^{-6} (E/GeV)^{-1.3} GeV^{-1} cm^{-2} yr^{-1}
sr^{-1}, at the 95% CL. Such a hard spectrum is characteristic of supermassive
particles' $N$-body hadronic decay. The case in which the flux of ultra-high
energy neutralinos is produced via decay of metastable heavy particles with
uniform distribution throughout the universe is analyzed in detail. The
normalization of the ratio of the relics' density to their lifetime has been
fixed so that the baryon flux produced in the supermassive particle decays
contributes to about 1/3 of the events reported by the AGASA Collaboration
below 10^{11} GeV, and hence the associated GeV gamma-ray flux is in complete
agreement with EGRET data. For this particular case, EUSO will collect between
4 and 5 neutralino events (with 0.3 of background) in ~ 3 yr of running. NASA's
planned mission, the Orbiting Wide-angle Light-collectors (OWL), is also
briefly discussed in this context.
| [
{
"created": "Thu, 11 Mar 2004 17:27:09 GMT",
"version": "v1"
},
{
"created": "Thu, 13 May 2004 15:42:54 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Anchordoqui",
"Luis",
""
],
[
"Goldberg",
"Haim",
""
],
[
"Nath",
"Pran",
""
]
] | An analysis is carried out within mSUGRA of the estimated number of events originating from upward moving ultra-high energy neutralinos that could be detected by the Extreme Universe Space Observatory (EUSO). The analysis exploits a recently proposed technique that differentiates ultra-high energy neutralinos from ultra-high energy neutrinos using their different absorption lengths in the Earth's crust. It is shown that for a significant part of the parameter space, where the neutralino is mostly a Bino and with squark mass $\sim 1$ TeV, EUSO could see ultra-high energy neutralino events with essentially no background. In the energy range 10^9 GeV < E < 10^11 GeV, the unprecedented aperture of EUSO makes the telescope sensitive to neutralino fluxes as low as 1.1 \times 10^{-6} (E/GeV)^{-1.3} GeV^{-1} cm^{-2} yr^{-1} sr^{-1}, at the 95% CL. Such a hard spectrum is characteristic of supermassive particles' $N$-body hadronic decay. The case in which the flux of ultra-high energy neutralinos is produced via decay of metastable heavy particles with uniform distribution throughout the universe is analyzed in detail. The normalization of the ratio of the relics' density to their lifetime has been fixed so that the baryon flux produced in the supermassive particle decays contributes to about 1/3 of the events reported by the AGASA Collaboration below 10^{11} GeV, and hence the associated GeV gamma-ray flux is in complete agreement with EGRET data. For this particular case, EUSO will collect between 4 and 5 neutralino events (with 0.3 of background) in ~ 3 yr of running. NASA's planned mission, the Orbiting Wide-angle Light-collectors (OWL), is also briefly discussed in this context. |
2209.01236 | Yushan Su | Yushan Su, Jack Holligan, Xiangdong Ji, Fei Yao, Jian-Hui Zhang, Rui
Zhang | Resumming Quark's Longitudinal Momentum Logarithms in LaMET Expansion of
Lattice PDFs | 17 pages, 9 figures | null | 10.1016/j.nuclphysb.2023.116201 | null | hep-ph hep-lat nucl-th | http://creativecommons.org/licenses/by/4.0/ | In the large-momentum expansion for parton distribution functions (PDFs), the
natural physics scale is the longitudinal momentum ($p_z$) of the quarks (or
gluons) in a large-momentum hadron. We show how to expose this scale dependence
through resumming logarithms of the type $\ln^n p_z/\mu$ in the matching
coefficient, where $\mu$ is a fixed renormalization scale. The result enhances
the accuracy of the expansion at moderate $p_z>1$ GeV, and at the same time,
clearly shows that the partons cannot be approximated from quarks with $p_z\sim
\Lambda_{\rm QCD}$ which are not predominantly collinear with the parent hadron
momentum, consistent with power counting of the large-momentum effective
theory. The same physics mechanism constrains the coordinate space expansion at
large distances $z$, the conjugate of $p_z$, as illustrated in the example of
fitting the moments of the PDFs.
| [
{
"created": "Fri, 2 Sep 2022 18:49:34 GMT",
"version": "v1"
},
{
"created": "Wed, 29 Mar 2023 22:11:59 GMT",
"version": "v2"
}
] | 2023-05-17 | [
[
"Su",
"Yushan",
""
],
[
"Holligan",
"Jack",
""
],
[
"Ji",
"Xiangdong",
""
],
[
"Yao",
"Fei",
""
],
[
"Zhang",
"Jian-Hui",
""
],
[
"Zhang",
"Rui",
""
]
] | In the large-momentum expansion for parton distribution functions (PDFs), the natural physics scale is the longitudinal momentum ($p_z$) of the quarks (or gluons) in a large-momentum hadron. We show how to expose this scale dependence through resumming logarithms of the type $\ln^n p_z/\mu$ in the matching coefficient, where $\mu$ is a fixed renormalization scale. The result enhances the accuracy of the expansion at moderate $p_z>1$ GeV, and at the same time, clearly shows that the partons cannot be approximated from quarks with $p_z\sim \Lambda_{\rm QCD}$ which are not predominantly collinear with the parent hadron momentum, consistent with power counting of the large-momentum effective theory. The same physics mechanism constrains the coordinate space expansion at large distances $z$, the conjugate of $p_z$, as illustrated in the example of fitting the moments of the PDFs. |
1709.00439 | Rodolfo Capdevilla | Rodolfo M. Capdevilla, Antonio Delgado, Adam Martin, Nirmal Raj | Characterizing dark matter at the LHC in Drell-Yan events | 18 pages, 9 figures, 1 table | Phys. Rev. D 97, 035016 (2018) | 10.1103/PhysRevD.97.035016 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Spectral features in LHC dileptonic events may signal radiative corrections
coming from new degrees of freedom, notably dark matter and mediators. Using
simplified models, we show how these features can reveal the fundamental
properties of the dark sector, such as self-conjugation, spin and mass of dark
matter, and the quantum numbers of the mediator. Distributions of both the
invariant mass $m_{\ell \ell}$ and the Collins-Soper scattering angle
$cos\theta_{CS}$ are studied to pinpoint these properties. We derive
constraints on the models from LHC measurements of $m_{\ell \ell}$ and
$cos\theta_{CS}$, which are competitive with direct detection and jets +
Missing Energy searches. We find that in certain scenarios the $cos\theta_{CS}$
spectrum provides the strongest bounds, underlying the importance of scattering
angle measurements for non-resonant new physics.
| [
{
"created": "Fri, 1 Sep 2017 18:40:53 GMT",
"version": "v1"
}
] | 2018-03-07 | [
[
"Capdevilla",
"Rodolfo M.",
""
],
[
"Delgado",
"Antonio",
""
],
[
"Martin",
"Adam",
""
],
[
"Raj",
"Nirmal",
""
]
] | Spectral features in LHC dileptonic events may signal radiative corrections coming from new degrees of freedom, notably dark matter and mediators. Using simplified models, we show how these features can reveal the fundamental properties of the dark sector, such as self-conjugation, spin and mass of dark matter, and the quantum numbers of the mediator. Distributions of both the invariant mass $m_{\ell \ell}$ and the Collins-Soper scattering angle $cos\theta_{CS}$ are studied to pinpoint these properties. We derive constraints on the models from LHC measurements of $m_{\ell \ell}$ and $cos\theta_{CS}$, which are competitive with direct detection and jets + Missing Energy searches. We find that in certain scenarios the $cos\theta_{CS}$ spectrum provides the strongest bounds, underlying the importance of scattering angle measurements for non-resonant new physics. |
hep-ph/0504219 | Ho-Meoyng Choi | Ho-Meoyng Choi and Cheung-Ryong Ji | The Light-Front Zero-Mode Contribution to the Good Current in Weak
Transition | 11 pages, 4figures, aps style file | Phys.Rev.D72:013004,2005 | 10.1103/PhysRevD.72.013004 | null | hep-ph | null | We examine the light-front zero-mode contribution to the good(+) current
matrix elements between pseudoscalar and vector mesons. In particular, we
discuss the transition form factor $f(q^2)$ which has been suspected to have
the light-front zero-mode contribution. While the zero-mode contribution in
principle depends on the form of the vector meson vertex $\Gamma^\mu=\gamma^\mu
- (P_V -2k)^\mu/D$, the form factor $f(q^2)$ is found to be free from the
zero-mode contribution if the denominator $D$ contains the term proportional to
the light-front energy $(k^-)^{n}$ with the power $n>0$. The lack of zero-mode
contribution benefits the light-front quark model phenomenology. We present our
numerical calculations for the $B\to\rho$ transition.
| [
{
"created": "Mon, 25 Apr 2005 10:43:27 GMT",
"version": "v1"
}
] | 2011-07-19 | [
[
"Choi",
"Ho-Meoyng",
""
],
[
"Ji",
"Cheung-Ryong",
""
]
] | We examine the light-front zero-mode contribution to the good(+) current matrix elements between pseudoscalar and vector mesons. In particular, we discuss the transition form factor $f(q^2)$ which has been suspected to have the light-front zero-mode contribution. While the zero-mode contribution in principle depends on the form of the vector meson vertex $\Gamma^\mu=\gamma^\mu - (P_V -2k)^\mu/D$, the form factor $f(q^2)$ is found to be free from the zero-mode contribution if the denominator $D$ contains the term proportional to the light-front energy $(k^-)^{n}$ with the power $n>0$. The lack of zero-mode contribution benefits the light-front quark model phenomenology. We present our numerical calculations for the $B\to\rho$ transition. |
2011.09774 | Giancarlo Rossi | Giancarlo Rossi, Gabriele Veneziano | Tetra-quarks, penta-quarks and the like: old and new views | QCD20 Conference paper | null | null | CERN-TH-2020-197 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this talk, after a short overview of the history of the discovery of
tetra-quarks and penta-quarks, we will discuss a possible interpretation of
such states in the framework of a 40-years-old "string junction" picture that
allows a unified QCD description of ordinary mesons and baryons as well as
multi-quark resonances.
| [
{
"created": "Thu, 19 Nov 2020 11:14:58 GMT",
"version": "v1"
}
] | 2020-11-20 | [
[
"Rossi",
"Giancarlo",
""
],
[
"Veneziano",
"Gabriele",
""
]
] | In this talk, after a short overview of the history of the discovery of tetra-quarks and penta-quarks, we will discuss a possible interpretation of such states in the framework of a 40-years-old "string junction" picture that allows a unified QCD description of ordinary mesons and baryons as well as multi-quark resonances. |
0911.3463 | Chung-I Tan | Richard Brower, Marko Djuric, Chung-I Tan | Elastic and Diffractive Scattering after AdS/CFT | 7 pages, 3 figures; presented at International Conference on Elastic
and Diffractive Scattering, EDS'09, CERN, July 3, 2009 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | At high energies, elastic hadronic cross sections are believed to be
dominated by vacuum exchange. In leading order of the leading $1/N_c$ expansion
this exchange process has been identified as the BFKL {\em Pomeron} or its
strong AdS dual the closed string graviton \cite{Brower:2006ea}. However
difference of particle anti-particle cross sections are given by a so-called
{\em Odderon} carrying C = -1 quantum numbers identified in weak coupling with
odd numbers of exchanged gluons. Here we show that the dual description
associates this with the Neveu-Schwartz ($B_{\mu\nu}$) sector of closed string
theory. We also discuss the extension of the strong coupling treatment to
central diffractive Higgs production at LHC.
| [
{
"created": "Wed, 18 Nov 2009 04:53:55 GMT",
"version": "v1"
}
] | 2009-11-19 | [
[
"Brower",
"Richard",
""
],
[
"Djuric",
"Marko",
""
],
[
"Tan",
"Chung-I",
""
]
] | At high energies, elastic hadronic cross sections are believed to be dominated by vacuum exchange. In leading order of the leading $1/N_c$ expansion this exchange process has been identified as the BFKL {\em Pomeron} or its strong AdS dual the closed string graviton \cite{Brower:2006ea}. However difference of particle anti-particle cross sections are given by a so-called {\em Odderon} carrying C = -1 quantum numbers identified in weak coupling with odd numbers of exchanged gluons. Here we show that the dual description associates this with the Neveu-Schwartz ($B_{\mu\nu}$) sector of closed string theory. We also discuss the extension of the strong coupling treatment to central diffractive Higgs production at LHC. |
2308.06705 | Guo-Liang Yu | Jie Lu, Guo-Liang Yu, Zhi-Gang Wang, Bin Wu | Analysis of the strong vertices of $\Sigma_{c}\Delta D^{*}$ and
$\Sigma_{b}\Delta B^{*}$ in QCD sum rules | null | Eur. Phys. J. C (2023) 83:907 | 10.1140/epjc/s10052-023-12076-8 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | In this work, we analyze the strong vertices $\Sigma_{c}\Delta D^{*}$ and
$\Sigma_{b}\Delta B^{*}$ using the three-point QCD sum rules under the tensor
structures $i\epsilon^{\rho\tau\alpha\beta}p_{\alpha}p'_{\beta}$,
$p^{\rho}p'^{\tau}$ and $p^{\rho}p^{\tau}$. We firstly calculate the momentum
dependent strong coupling constants $g(Q^{2})$ by considering contributions of
the perturbative part and the condensate terms $\langle\overline{q}q\rangle$,
$\langle g_{s}^{2}GG \rangle$, $\langle\overline{q}g_{s}\sigma Gq\rangle$ and
$\langle\overline{q}q\rangle^{2}$. By fitting these coupling constants into
analytical functions and extrapolating them into time-like regions, we then
obtain the on-shell values of strong coupling constants for these vertices. The
results are $g_{1\Sigma_{c}\Delta D^{*}}=5.13^{+0.39}_{-0.49}$ GeV$^{-1}$,
$g_{2\Sigma_{c}\Delta D^{*}}=-3.03^{+0.27}_{-0.35}$ GeV$^{-2}$,
$g_{3\Sigma_{c}\Delta D^{*}}=17.64^{+1.51}_{-1.95}$ GeV$^{-2}$,
$g_{1\Sigma_{b}\Delta B^{*}}=20.97^{+2.15}_{-2.39}$ GeV$^{-1}$,
$g_{2\Sigma_{b}\Delta B^{*}}=-11.42^{+1.17}_{-1.28}$ GeV$^{-2}$ and
$g_{3\Sigma_{b}\Delta B^{*}}=24.87^{+2.57}_{-2.82}$ GeV$^{-2}$. These strong
coupling constants are important parameters which can help us to understand the
strong decay behaviors of hadrons.
| [
{
"created": "Sun, 13 Aug 2023 07:43:51 GMT",
"version": "v1"
},
{
"created": "Wed, 16 Aug 2023 08:49:15 GMT",
"version": "v2"
},
{
"created": "Tue, 10 Oct 2023 04:16:42 GMT",
"version": "v3"
},
{
"created": "Sun, 15 Oct 2023 04:24:39 GMT",
"version": "v4"
}
] | 2023-10-17 | [
[
"Lu",
"Jie",
""
],
[
"Yu",
"Guo-Liang",
""
],
[
"Wang",
"Zhi-Gang",
""
],
[
"Wu",
"Bin",
""
]
] | In this work, we analyze the strong vertices $\Sigma_{c}\Delta D^{*}$ and $\Sigma_{b}\Delta B^{*}$ using the three-point QCD sum rules under the tensor structures $i\epsilon^{\rho\tau\alpha\beta}p_{\alpha}p'_{\beta}$, $p^{\rho}p'^{\tau}$ and $p^{\rho}p^{\tau}$. We firstly calculate the momentum dependent strong coupling constants $g(Q^{2})$ by considering contributions of the perturbative part and the condensate terms $\langle\overline{q}q\rangle$, $\langle g_{s}^{2}GG \rangle$, $\langle\overline{q}g_{s}\sigma Gq\rangle$ and $\langle\overline{q}q\rangle^{2}$. By fitting these coupling constants into analytical functions and extrapolating them into time-like regions, we then obtain the on-shell values of strong coupling constants for these vertices. The results are $g_{1\Sigma_{c}\Delta D^{*}}=5.13^{+0.39}_{-0.49}$ GeV$^{-1}$, $g_{2\Sigma_{c}\Delta D^{*}}=-3.03^{+0.27}_{-0.35}$ GeV$^{-2}$, $g_{3\Sigma_{c}\Delta D^{*}}=17.64^{+1.51}_{-1.95}$ GeV$^{-2}$, $g_{1\Sigma_{b}\Delta B^{*}}=20.97^{+2.15}_{-2.39}$ GeV$^{-1}$, $g_{2\Sigma_{b}\Delta B^{*}}=-11.42^{+1.17}_{-1.28}$ GeV$^{-2}$ and $g_{3\Sigma_{b}\Delta B^{*}}=24.87^{+2.57}_{-2.82}$ GeV$^{-2}$. These strong coupling constants are important parameters which can help us to understand the strong decay behaviors of hadrons. |
hep-ph/0606033 | Grunberg | Georges Grunberg | Evidence for infrared finite coupling in Sudakov resummation: a revised
view-point | 5 pages; to appear in the Proceedings of the FRIF Workshop on First
Principles Non-Perturbative QCD of Hadron Jets (Paris, 12-14 January 2006).
Version 2: hints are given supporting the existence of a Banks-Zaks type of
fixed point in the Euclidean Sudakov coupling at finite N_f; strong evidence
provided that this fixed point is universal; added references | ECONFC0601121:E001,2006 | null | null | hep-ph | null | I show that Sudakov resummation takes a particularly transparent form if one
deals with the second logarithmic derivative of the short distance coefficient
functions for deep inelastic scattering and the Drell-Yan process. A uniquely
defined Sudakov exponent emerges, and I conjecture that the leftover constant
terms not included in the exponent are given by the second logarithmic
derivative of the massless quark form factor. The meaning of a previously
obtained large $N_f$ evidence for an infrared finite perturbative Sudakov
coupling is reconsidered. This coupling is reinterpreted as a Minkowskian
coupling, making the introduction of a low-energy non-perturbative modification
of the corresponding Euclidean coupling a priori necessary. Some hints for a
Banks-Zaks type of fixed point in the Euclidean coupling at finite $N_f$ are
nevertheless pointed out, and strong evidence is provided in favor of its
universality. A criterion to select in a unique way the proper Euclidean
Sudakov coupling relevant to the issue of power corrections is suggested.
| [
{
"created": "Fri, 2 Jun 2006 16:21:07 GMT",
"version": "v1"
},
{
"created": "Fri, 30 Jun 2006 14:03:44 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Grunberg",
"Georges",
""
]
] | I show that Sudakov resummation takes a particularly transparent form if one deals with the second logarithmic derivative of the short distance coefficient functions for deep inelastic scattering and the Drell-Yan process. A uniquely defined Sudakov exponent emerges, and I conjecture that the leftover constant terms not included in the exponent are given by the second logarithmic derivative of the massless quark form factor. The meaning of a previously obtained large $N_f$ evidence for an infrared finite perturbative Sudakov coupling is reconsidered. This coupling is reinterpreted as a Minkowskian coupling, making the introduction of a low-energy non-perturbative modification of the corresponding Euclidean coupling a priori necessary. Some hints for a Banks-Zaks type of fixed point in the Euclidean coupling at finite $N_f$ are nevertheless pointed out, and strong evidence is provided in favor of its universality. A criterion to select in a unique way the proper Euclidean Sudakov coupling relevant to the issue of power corrections is suggested. |
1307.5572 | Yue Chongxing | Chong-Xing Yue, Qiu-Yang Shi, Tian Hua | Vector bileptons and the decays $h\rightarrow \gamma\gamma,Z\gamma$ | References added | null | 10.1016/j.nuclphysb.2013.09.004 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Takeing into account of the constraints on the relevant parameters from the
muon anomalous magnetic moment, we consider the contributions of the vector
bileptons $V^{\pm}$ and $U^{\pm\pm}$ predicted by the reduced minimal 331 model
to the Higgs decay channels $h \rightarrow \gamma \gamma$ and $Z\gamma$. Our
numerical results show that the vector bileptons can enhance the partial width
$\Gamma(h\rightarrow \gamma\gamma)$, while reduce the partial width
$\Gamma(h\rightarrow Z\gamma)$, which are anti-correlated. With reasonable
values of the relevant free parameters, the vector bileptons can explain the
$LHC$ data for the $\gamma\gamma$ signal. If the $CMS$ data persists, the value
of the free parameters $ \lambda_{2}$ and $ \lambda_{3}$ should be severe
constrained.
| [
{
"created": "Mon, 22 Jul 2013 00:01:43 GMT",
"version": "v1"
},
{
"created": "Mon, 2 Sep 2013 12:23:12 GMT",
"version": "v2"
}
] | 2015-06-16 | [
[
"Yue",
"Chong-Xing",
""
],
[
"Shi",
"Qiu-Yang",
""
],
[
"Hua",
"Tian",
""
]
] | Takeing into account of the constraints on the relevant parameters from the muon anomalous magnetic moment, we consider the contributions of the vector bileptons $V^{\pm}$ and $U^{\pm\pm}$ predicted by the reduced minimal 331 model to the Higgs decay channels $h \rightarrow \gamma \gamma$ and $Z\gamma$. Our numerical results show that the vector bileptons can enhance the partial width $\Gamma(h\rightarrow \gamma\gamma)$, while reduce the partial width $\Gamma(h\rightarrow Z\gamma)$, which are anti-correlated. With reasonable values of the relevant free parameters, the vector bileptons can explain the $LHC$ data for the $\gamma\gamma$ signal. If the $CMS$ data persists, the value of the free parameters $ \lambda_{2}$ and $ \lambda_{3}$ should be severe constrained. |
0912.2226 | Juan Nieves Dr. | J. Nieves, J.M. Flynn and E. Hernandez | Semileptonic bc to cc and bb to bc Baryon Decays and Heavy Quark Spin
Symmetry | 4 latex pages. Talk given at The 5-th International Conference on
Quarks and Nuclear Physics (QNP09), Beijing, September 2009 | null | 10.1088/1674-1137/34/9/043 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the semileptonic decays of the lowest-lying $bc$ baryons to the
lowest-lying $cc$ baryons ($\Xi_{bc}^{(\prime*)}\to \Xi_{cc}^{(*)}$ and
$\Omega_{bc}^{(\prime*)}\to \Omega_{cc}^{(*)}$), in the limit $m_b, m_c \gg
\Lambda_\mathrm{QCD}$ and close to the zero recoil point. The separate heavy
quark spin symmetries make it possible to describe all these decays using a
single form factor. We also show how these constraints can be used to test the
validity of different quark model calculations. $bb$ to $bc$ baryon decays are
also discussed.
| [
{
"created": "Fri, 11 Dec 2009 13:20:25 GMT",
"version": "v1"
}
] | 2015-05-14 | [
[
"Nieves",
"J.",
""
],
[
"Flynn",
"J. M.",
""
],
[
"Hernandez",
"E.",
""
]
] | We study the semileptonic decays of the lowest-lying $bc$ baryons to the lowest-lying $cc$ baryons ($\Xi_{bc}^{(\prime*)}\to \Xi_{cc}^{(*)}$ and $\Omega_{bc}^{(\prime*)}\to \Omega_{cc}^{(*)}$), in the limit $m_b, m_c \gg \Lambda_\mathrm{QCD}$ and close to the zero recoil point. The separate heavy quark spin symmetries make it possible to describe all these decays using a single form factor. We also show how these constraints can be used to test the validity of different quark model calculations. $bb$ to $bc$ baryon decays are also discussed. |
0904.0230 | Arif Erkoca Mr. | Arif Emre Erkoca, Gouranga C. Nayak, Ina Sarcevic | Higgs Production and Decay from TeV Scale Black Holes at the LHC | 28 pages, 10 figures, 2 tables. Typo corrected; version accepted for
publication in Phys. Rev. D | Phys.Rev.D79:094011,2009 | 10.1103/PhysRevD.79.094011 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We perform detailed study of the Higgs production and decay, when Higgs is
emitted from the black holes produced in proton-proton collisions at the Large
Hadron Collider. We show that black hole production can significantly enhance
the signal for the Higgs search at the LHC. We evaluate rapidity distribution
of diphotons and transverse momentum distribution of bottom quarks, photons,
tau leptons, top quarks and W bosons from Higgs decay, when Higgs is emitted
from the black hole and also in case when these particles are produced directly
from the black hole evaporation. We compare our results with the standard model
backgrounds. We find that Higgs production from black holes is dominant over
standard model production for $p_T^H > 100$ GeV, when $M_P=1$TeV. Diphotons
from Higgs, when Higgs is produced from evaporation of black holes, are
dominant over the standard model prediction, for diphoton rapidity $|y_{\gamma
\gamma}| \leq 1$, while bottom quarks are dominant over QCD background for
large bottom quark transverse momentum, $p_T^b > 300$ GeV, when $M_P=1$ TeV. We
show that measurements of the photon and bottom quark transverse momentum
distribution can provide valuable information about the value of the
fundamental Planck scale. We also propose a new signal for black hole
production at the LHC, an onset of increasing transverse momentum distribution
of bottom quarks with large transverse momentum.
| [
{
"created": "Wed, 1 Apr 2009 18:09:15 GMT",
"version": "v1"
},
{
"created": "Wed, 1 Apr 2009 21:44:26 GMT",
"version": "v2"
},
{
"created": "Sun, 26 Apr 2009 23:02:22 GMT",
"version": "v3"
}
] | 2011-01-27 | [
[
"Erkoca",
"Arif Emre",
""
],
[
"Nayak",
"Gouranga C.",
""
],
[
"Sarcevic",
"Ina",
""
]
] | We perform detailed study of the Higgs production and decay, when Higgs is emitted from the black holes produced in proton-proton collisions at the Large Hadron Collider. We show that black hole production can significantly enhance the signal for the Higgs search at the LHC. We evaluate rapidity distribution of diphotons and transverse momentum distribution of bottom quarks, photons, tau leptons, top quarks and W bosons from Higgs decay, when Higgs is emitted from the black hole and also in case when these particles are produced directly from the black hole evaporation. We compare our results with the standard model backgrounds. We find that Higgs production from black holes is dominant over standard model production for $p_T^H > 100$ GeV, when $M_P=1$TeV. Diphotons from Higgs, when Higgs is produced from evaporation of black holes, are dominant over the standard model prediction, for diphoton rapidity $|y_{\gamma \gamma}| \leq 1$, while bottom quarks are dominant over QCD background for large bottom quark transverse momentum, $p_T^b > 300$ GeV, when $M_P=1$ TeV. We show that measurements of the photon and bottom quark transverse momentum distribution can provide valuable information about the value of the fundamental Planck scale. We also propose a new signal for black hole production at the LHC, an onset of increasing transverse momentum distribution of bottom quarks with large transverse momentum. |
2306.05333 | Geng Li | Geng Li and Jusak Tandean | FCNC charmed-hadron decays with invisible singlet particles in light of
recent data | 26 pages, 38 figures, Published version | null | 10.1007/JHEP11(2023)205 | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | The flavor-changing neutral current (FCNC) decays of charmed hadrons with
missing energy $(\not\!\!E)$ can serve as potentially promising hunting grounds
for hints of new physics, as the standard-model backgrounds are very
suppressed. A few of such processes have been searched for in recent
experiments, specifically $D^0\to\,\not\!\!E$ by Belle and
$D^0\to\pi^0$$\not\!\!E$ and $\Lambda_c^+\to p\!\not\!\!E$ by BESIII, resulting
in upper bounds on their branching fractions. We consider them to illuminate
the possible contributions of the quark transition $c\to u\!\not\!\!E$ with a
couple of invisible spinless bosons carrying away the missing energy, assuming
that they are not charge conjugates of each other and hence can have unequal
masses. We find that these data are complementary in that they constrain
different sets of the underlying operators and do not cover the same ranges of
the bosons' masses, but there are regions not yet accessible. From the allowed
parameter space, we show that other $D$-meson decays, such as
$D\to\rho$$\not\!\!E$, and the charmed-baryon ones
$\Xi_c\to(\Sigma,\Lambda)$$\not\!\!E$ can have sizable branching fractions and
therefore may offer further probes of the new-physics interactions. We point
out the importance of $D^0\to\gamma\!\not\!\!E$ which are not yet searched for
but could access parts of the parameter space beyond the reach of the other
modes. In addition, we look at a scenario where the invisibles are instead
fermionic, namely sterile neutrinos, and a scalar leptoquark mediates $c\to
u\!\not\!\!E$. We discuss the implications of the aforesaid bounds for this
model. The predictions we make for the various charmed-hadron decays in the
different scenarios may be testable in the near future by BESIII and Belle II.
| [
{
"created": "Thu, 8 Jun 2023 16:32:26 GMT",
"version": "v1"
},
{
"created": "Sat, 24 Jun 2023 08:45:27 GMT",
"version": "v2"
},
{
"created": "Wed, 29 Nov 2023 10:17:22 GMT",
"version": "v3"
},
{
"created": "Fri, 1 Dec 2023 08:50:41 GMT",
"version": "v4"
}
] | 2023-12-04 | [
[
"Li",
"Geng",
""
],
[
"Tandean",
"Jusak",
""
]
] | The flavor-changing neutral current (FCNC) decays of charmed hadrons with missing energy $(\not\!\!E)$ can serve as potentially promising hunting grounds for hints of new physics, as the standard-model backgrounds are very suppressed. A few of such processes have been searched for in recent experiments, specifically $D^0\to\,\not\!\!E$ by Belle and $D^0\to\pi^0$$\not\!\!E$ and $\Lambda_c^+\to p\!\not\!\!E$ by BESIII, resulting in upper bounds on their branching fractions. We consider them to illuminate the possible contributions of the quark transition $c\to u\!\not\!\!E$ with a couple of invisible spinless bosons carrying away the missing energy, assuming that they are not charge conjugates of each other and hence can have unequal masses. We find that these data are complementary in that they constrain different sets of the underlying operators and do not cover the same ranges of the bosons' masses, but there are regions not yet accessible. From the allowed parameter space, we show that other $D$-meson decays, such as $D\to\rho$$\not\!\!E$, and the charmed-baryon ones $\Xi_c\to(\Sigma,\Lambda)$$\not\!\!E$ can have sizable branching fractions and therefore may offer further probes of the new-physics interactions. We point out the importance of $D^0\to\gamma\!\not\!\!E$ which are not yet searched for but could access parts of the parameter space beyond the reach of the other modes. In addition, we look at a scenario where the invisibles are instead fermionic, namely sterile neutrinos, and a scalar leptoquark mediates $c\to u\!\not\!\!E$. We discuss the implications of the aforesaid bounds for this model. The predictions we make for the various charmed-hadron decays in the different scenarios may be testable in the near future by BESIII and Belle II. |
hep-ph/9612356 | Jon Pumplin | Jon Pumplin (Michigan State University) | Diffractive Photoproduction of Z0 | 14 pages (REVTeX) + 1 Figure (epsf) | null | null | MSUHEP/61222 | hep-ph | null | The two gluon exchange model of the pomeron is used to compute the
photoproduction reaction $\gamma p \to Z^0 p$. The predicted cross section is
too small to be observed at HERA, but may be detectable at an eventual Next
Linear Collider.
| [
{
"created": "Fri, 13 Dec 1996 18:35:42 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Pumplin",
"Jon",
"",
"Michigan State University"
]
] | The two gluon exchange model of the pomeron is used to compute the photoproduction reaction $\gamma p \to Z^0 p$. The predicted cross section is too small to be observed at HERA, but may be detectable at an eventual Next Linear Collider. |
2305.02050 | Vadim Bednyakov Dr. | Vadim A. Bednyakov | On underestimation of the inelastic interactions in the direct dark
matter search | 60 pages 24 figures, 176 references | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | In the paper expressions are obtained for the event rates expected in
experiments aimed at direct detection of dark matter (DM) particles. These
expressions allow one to estimate the rates taking into account simultaneously
elastic (coherent) and inelastic (incoherent) channels of DM particle
interaction with nuclei. The nonzero nuclear excitation energies are used in
the calculation of the inelastic scattering contributions. A strong correlation
between the excitation energy and the recoil energy of the excited nucleus
limits the possibility of the inelastic channel detection with a number of
nuclei. Together with the standard model of the DM distribution in the Galaxy
some models are considered, which allow higher speeds of the DM particle. As
the nuclear recoil energy, TA, increases, the dominance of the elastic
interaction channel is smoothly replaced by the dominance of the inelastic one.
Therefore, if a detector is set up to detect only elastic scattering events, it
starts to lose capability of seeing anything. The only way to notice the
interaction remains the gamma radiation from the deexcitation of the nucleus.
In the case of spin-independent DM interaction, as TA increases, the inelastic
contribution quickly dominates. If the DM particle interacts only
spin-dependently, the detectors focused on registration of the elastic
spin-dependent DM signal will see nothing, since the signal goes through the
inelastic channel. It looks like the desired DM interaction could have a
noticeable intensity, but the DM detector is unable to detect it. Therefore, a
setup aimed at the direct DM detection should register two signals. The first
is the nuclear recoil energy and the second is the gamma-quanta with a certain
energy from the target nucleus deexitation. The experiment will provide the
complete information about the DM interaction.
| [
{
"created": "Wed, 3 May 2023 11:33:12 GMT",
"version": "v1"
}
] | 2023-05-04 | [
[
"Bednyakov",
"Vadim A.",
""
]
] | In the paper expressions are obtained for the event rates expected in experiments aimed at direct detection of dark matter (DM) particles. These expressions allow one to estimate the rates taking into account simultaneously elastic (coherent) and inelastic (incoherent) channels of DM particle interaction with nuclei. The nonzero nuclear excitation energies are used in the calculation of the inelastic scattering contributions. A strong correlation between the excitation energy and the recoil energy of the excited nucleus limits the possibility of the inelastic channel detection with a number of nuclei. Together with the standard model of the DM distribution in the Galaxy some models are considered, which allow higher speeds of the DM particle. As the nuclear recoil energy, TA, increases, the dominance of the elastic interaction channel is smoothly replaced by the dominance of the inelastic one. Therefore, if a detector is set up to detect only elastic scattering events, it starts to lose capability of seeing anything. The only way to notice the interaction remains the gamma radiation from the deexcitation of the nucleus. In the case of spin-independent DM interaction, as TA increases, the inelastic contribution quickly dominates. If the DM particle interacts only spin-dependently, the detectors focused on registration of the elastic spin-dependent DM signal will see nothing, since the signal goes through the inelastic channel. It looks like the desired DM interaction could have a noticeable intensity, but the DM detector is unable to detect it. Therefore, a setup aimed at the direct DM detection should register two signals. The first is the nuclear recoil energy and the second is the gamma-quanta with a certain energy from the target nucleus deexitation. The experiment will provide the complete information about the DM interaction. |
2211.10091 | Toshifumi Yamada | Naoyuki Haba, Toshifumi Yamada | Conditions for Suppressing Dimension-five Proton Decay in Renormalizable
SUSY $SO(10)$ GUT | 34 pages, 2 figures. Version accepted for publication in JHEP | null | 10.1007/JHEP02(2023)148 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | The SUSY $SO(10)$ GUT is in severe tension with the experimental bounds on
proton partial lifetimes because proton decay mediated by colored Higgsinos
(dimension-five proton decay) is too rapid. In this paper, we pursue the
possibility that a texture of the Yukawa coupling matrices in a renormalizable
SUSY $SO(10)$ GUT model suppresses dimension-five proton decay. We focus on a
general renormalizable SUSY $SO(10)$ GUT model which contains ${\bf 10}+{\bf
126}+{\bf \overline{126}}+{\bf 120}$ representation fields and where the Yukawa
coupling matrices of the ${\bf 16}$ matter fields with the ${\bf 10}$, ${\bf
\overline{126}}$, ${\bf 120}$ fields, $Y_{10},Y_{126},Y_{120}$, provide the
quark and lepton Yukawa couplings and Majorana mass of the singlet neutrinos.
We find that if components in certain flavor bases, $(Y_{10})_{u_R d_R}$,
$(Y_{126})_{u_R d_R}$, $(Y_{10})_{u_R s_R}$, $(Y_{126})_{u_R s_R}$,
$(Y_{10})_{u_L d_L}$, $(Y_{126})_{u_L d_L}$, $(Y_{10})_{u_L s_L}$,
$(Y_{126})_{u_L s_L}$, $(Y_{10})_{u_L u_L}$, $(Y_{126})_{u_L u_L}$, are all on
the order of the up quark Yukawa coupling, dimension-five proton decay can be
suppressed while the Yukawa coupling matrices still reproduce the realistic
quark and lepton masses and flavor mixings. We numerically obtain specific
Yukawa coupling matrices satisfying the above conditions, calculate proton
partial lifetimes from them and evaluate how dimension-five proton decay is
suppressed when these conditions are met.
| [
{
"created": "Fri, 18 Nov 2022 08:38:52 GMT",
"version": "v1"
},
{
"created": "Thu, 24 Nov 2022 16:16:59 GMT",
"version": "v2"
},
{
"created": "Mon, 6 Feb 2023 01:41:04 GMT",
"version": "v3"
}
] | 2023-03-22 | [
[
"Haba",
"Naoyuki",
""
],
[
"Yamada",
"Toshifumi",
""
]
] | The SUSY $SO(10)$ GUT is in severe tension with the experimental bounds on proton partial lifetimes because proton decay mediated by colored Higgsinos (dimension-five proton decay) is too rapid. In this paper, we pursue the possibility that a texture of the Yukawa coupling matrices in a renormalizable SUSY $SO(10)$ GUT model suppresses dimension-five proton decay. We focus on a general renormalizable SUSY $SO(10)$ GUT model which contains ${\bf 10}+{\bf 126}+{\bf \overline{126}}+{\bf 120}$ representation fields and where the Yukawa coupling matrices of the ${\bf 16}$ matter fields with the ${\bf 10}$, ${\bf \overline{126}}$, ${\bf 120}$ fields, $Y_{10},Y_{126},Y_{120}$, provide the quark and lepton Yukawa couplings and Majorana mass of the singlet neutrinos. We find that if components in certain flavor bases, $(Y_{10})_{u_R d_R}$, $(Y_{126})_{u_R d_R}$, $(Y_{10})_{u_R s_R}$, $(Y_{126})_{u_R s_R}$, $(Y_{10})_{u_L d_L}$, $(Y_{126})_{u_L d_L}$, $(Y_{10})_{u_L s_L}$, $(Y_{126})_{u_L s_L}$, $(Y_{10})_{u_L u_L}$, $(Y_{126})_{u_L u_L}$, are all on the order of the up quark Yukawa coupling, dimension-five proton decay can be suppressed while the Yukawa coupling matrices still reproduce the realistic quark and lepton masses and flavor mixings. We numerically obtain specific Yukawa coupling matrices satisfying the above conditions, calculate proton partial lifetimes from them and evaluate how dimension-five proton decay is suppressed when these conditions are met. |
hep-ph/0011051 | Giovanni De Lellis | G. D'Ambrosio, G. De Lellis, F. Di Capua, G. Miele, P. Migliozzi, P.
Santorelli | A search for Z' in muon neutrino associated charm production | 13 pages, 3 figures, latex | Phys.Lett.B494:19-25,2000 | 10.1016/S0370-2693(00)01190-4 | CERN-EP/2000-117, DSF-26-2000 | hep-ph | null | In many extensions of the Standard Model the presence of an extra neutral
boson, Z', is invoked. A precision study of weak neutral-current exchange
processes involving only second generation fermions is still missing. We
propose a search for Z' in muon neutrino associated charm production. This
process only involves Z' couplings with fermions from the second generation. An
experimental method is thoroughly described using an ideal detector. As an
application, the accuracy reachable with present and future experiments has
been estimated.
| [
{
"created": "Fri, 3 Nov 2000 13:59:31 GMT",
"version": "v1"
}
] | 2011-03-23 | [
[
"D'Ambrosio",
"G.",
""
],
[
"De Lellis",
"G.",
""
],
[
"Di Capua",
"F.",
""
],
[
"Miele",
"G.",
""
],
[
"Migliozzi",
"P.",
""
],
[
"Santorelli",
"P.",
""
]
] | In many extensions of the Standard Model the presence of an extra neutral boson, Z', is invoked. A precision study of weak neutral-current exchange processes involving only second generation fermions is still missing. We propose a search for Z' in muon neutrino associated charm production. This process only involves Z' couplings with fermions from the second generation. An experimental method is thoroughly described using an ideal detector. As an application, the accuracy reachable with present and future experiments has been estimated. |
hep-ph/9909507 | Jamal Jalilian-Marian | J. Jalilian-Marian | Shadowing of Gluons at RHIC and LHC | 6 pages, 1 figure, Talk given at XXIX Int. Symp. on Multiparticle
Dynamics (ISMD99), 9-13 August 1999, Providence, RI, USA | null | null | LBNL - 44316 Abs | hep-ph | null | We show estimates for shadowing of gluons at small values of $x$, appropriate
to RHIC and LHC experiments using a new evolution equation which takes into
account the effects of gluon recombination to all orders in gluon density. We
show that there is a significant depletion in the gluon density of large
nuclei.
| [
{
"created": "Fri, 24 Sep 1999 23:48:35 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Jalilian-Marian",
"J.",
""
]
] | We show estimates for shadowing of gluons at small values of $x$, appropriate to RHIC and LHC experiments using a new evolution equation which takes into account the effects of gluon recombination to all orders in gluon density. We show that there is a significant depletion in the gluon density of large nuclei. |
hep-ph/0305100 | Zsolt Szep | A. Patkos, Zs. Szep, P. Szepfalusy | Universal threshold enhancement | 4 pages, 2 figures | Phys.Rev. D68 (2003) 047701 | 10.1103/PhysRevD.68.047701 | null | hep-ph | null | By assuming certain analytic properties of the propagator, it is shown that
universal features of the spectral function including threshold enhancement
arise if a pole describing a particle at high temperature approaches in the
complex energy plane the threshold position of its two-body decay with the
variation of T. The case is considered, when one can disregard any other decay
processes. The quality of the proposed description is demonstrated by comparing
it with the detailed large N solution of the linear sigma model around the
pole-threshold coincidence.
| [
{
"created": "Fri, 9 May 2003 12:12:01 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Patkos",
"A.",
""
],
[
"Szep",
"Zs.",
""
],
[
"Szepfalusy",
"P.",
""
]
] | By assuming certain analytic properties of the propagator, it is shown that universal features of the spectral function including threshold enhancement arise if a pole describing a particle at high temperature approaches in the complex energy plane the threshold position of its two-body decay with the variation of T. The case is considered, when one can disregard any other decay processes. The quality of the proposed description is demonstrated by comparing it with the detailed large N solution of the linear sigma model around the pole-threshold coincidence. |
2205.14427 | Gowthama K K | Gowthama K K, Manu Kurian, Vinod Chandra | Thermal and thermoelectric responses of hot QCD medium in time-varying
magnetic fields | 11 pages, 6 figures, The version accepted in PRD | Phys. Rev. D 106, 034008 (2022) | 10.1103/PhysRevD.106.034008 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The thermal response of the hot QCD matter has been studied in the presence
of a time-varying magnetic field. The impact of magnetic field, its time
dependence, and the collision aspects of the medium on thermal transport have
been studied within the relativistic kinetic theory. The decay time of the
magnetic field in the medium seems to have a strong dependence on thermal
conductivity. The applicability of the Wiedemann-Franz law for the QCD medium
has been investigated in the presence of time-varying external electromagnetic
fields. The phenomenological significance of thermal transport in heavy-ion
collision experiments has also been investigated by relating the thermal
conductivity to the elliptic flow through the Knudsen number. The
investigations are extended to study the thermoelectric behavior of hot QCD
medium and its dependence on the magnetic field. The time dependent magnetic
field is observed to significantly influence the thermoelectric behavior of the
medium.
| [
{
"created": "Sat, 28 May 2022 13:17:01 GMT",
"version": "v1"
},
{
"created": "Thu, 4 Aug 2022 19:01:31 GMT",
"version": "v2"
}
] | 2022-08-10 | [
[
"K",
"Gowthama K",
""
],
[
"Kurian",
"Manu",
""
],
[
"Chandra",
"Vinod",
""
]
] | The thermal response of the hot QCD matter has been studied in the presence of a time-varying magnetic field. The impact of magnetic field, its time dependence, and the collision aspects of the medium on thermal transport have been studied within the relativistic kinetic theory. The decay time of the magnetic field in the medium seems to have a strong dependence on thermal conductivity. The applicability of the Wiedemann-Franz law for the QCD medium has been investigated in the presence of time-varying external electromagnetic fields. The phenomenological significance of thermal transport in heavy-ion collision experiments has also been investigated by relating the thermal conductivity to the elliptic flow through the Knudsen number. The investigations are extended to study the thermoelectric behavior of hot QCD medium and its dependence on the magnetic field. The time dependent magnetic field is observed to significantly influence the thermoelectric behavior of the medium. |
2001.05910 | Digesh Raut | Nobuchika Okada, Digesh Raut, and Qaisar Shafi | Pseudo-Goldstone Dark Matter in gauged $B-L$ extended Standard Model | 13 pages, 2 figures, updated version accepted for publication in PRD | Phys. Rev. D 103, 055024 (2021) | 10.1103/PhysRevD.103.055024 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | Gauging the global $B-L$ (Baryon number minus Lepton number) symmetry in the
Standard Model (SM) is well-motivated since anomaly cancellations require the
introduction of three right-handed neutrinos (RHNs) which play an essential
role in naturally generating tiny SM neutrino masses through the seesaw
mechanism. In the context of the $B-L$ extended SM, we propose a
pseudo-Goldstone boson dark matter (DM) scenario in which the imaginary
component of a complex $B-L$ Higgs field serves as the DM in the universe. The
DM relic density is determined by the SM Higgs boson mediated process, but its
elastic scattering with nucleons through the exchange of Higgs bosons is highly
suppressed due to its pseudo-Goldstone boson nature. The model is therefore
free from the constraints arising from direct DM detection experiments. We
identify regions of the model parameter space for reproducing the observed DM
density compatible with the constraints from the Large Hadron Collider and the
indirect DM searches by Fermi-LAT and MAGIC.
| [
{
"created": "Thu, 16 Jan 2020 15:55:25 GMT",
"version": "v1"
},
{
"created": "Wed, 10 Mar 2021 12:03:35 GMT",
"version": "v2"
}
] | 2021-04-07 | [
[
"Okada",
"Nobuchika",
""
],
[
"Raut",
"Digesh",
""
],
[
"Shafi",
"Qaisar",
""
]
] | Gauging the global $B-L$ (Baryon number minus Lepton number) symmetry in the Standard Model (SM) is well-motivated since anomaly cancellations require the introduction of three right-handed neutrinos (RHNs) which play an essential role in naturally generating tiny SM neutrino masses through the seesaw mechanism. In the context of the $B-L$ extended SM, we propose a pseudo-Goldstone boson dark matter (DM) scenario in which the imaginary component of a complex $B-L$ Higgs field serves as the DM in the universe. The DM relic density is determined by the SM Higgs boson mediated process, but its elastic scattering with nucleons through the exchange of Higgs bosons is highly suppressed due to its pseudo-Goldstone boson nature. The model is therefore free from the constraints arising from direct DM detection experiments. We identify regions of the model parameter space for reproducing the observed DM density compatible with the constraints from the Large Hadron Collider and the indirect DM searches by Fermi-LAT and MAGIC. |
1804.10215 | Jasmine Brewer | Jasmine Brewer, Swagato Mukherjee, Krishna Rajagopal, Yi Yin | Searching for the QCD critical point via the rapidity dependence of
cumulants | 6 pages, 2 figures | Phys. Rev. C 98, 061901 (2018) | 10.1103/PhysRevC.98.061901 | MIT-CTP/4998 | hep-ph nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The search for a possible critical point in the QCD phase diagram is ongoing
in heavy ion collision experiments at RHIC which scan the phase diagram by
scanning the beam energy; a coming upgrade will increase the luminosity and
extend the rapidity acceptance of the STAR detector. In fireballs produced in
RHIC collisions, the baryon density depends on rapidity. By employing Ising
universality together with a phenomenologically motivated freezeout
prescription, we show that the resulting rapidity dependence of cumulant
observables sensitive to critical fluctuations is distinctive. The dependence
of the kurtosis (of the event-by-event distribution of the number of protons)
on rapidity near mid-rapidity will change qualitatively if a critical point is
passed in the scan. Hence, measuring the rapidity dependence of cumulant
observables can enhance the prospect of discovering a critical point, in
particular if it lies between two energies in the beam energy scan.
| [
{
"created": "Thu, 26 Apr 2018 18:00:32 GMT",
"version": "v1"
},
{
"created": "Thu, 17 May 2018 21:46:05 GMT",
"version": "v2"
}
] | 2018-12-19 | [
[
"Brewer",
"Jasmine",
""
],
[
"Mukherjee",
"Swagato",
""
],
[
"Rajagopal",
"Krishna",
""
],
[
"Yin",
"Yi",
""
]
] | The search for a possible critical point in the QCD phase diagram is ongoing in heavy ion collision experiments at RHIC which scan the phase diagram by scanning the beam energy; a coming upgrade will increase the luminosity and extend the rapidity acceptance of the STAR detector. In fireballs produced in RHIC collisions, the baryon density depends on rapidity. By employing Ising universality together with a phenomenologically motivated freezeout prescription, we show that the resulting rapidity dependence of cumulant observables sensitive to critical fluctuations is distinctive. The dependence of the kurtosis (of the event-by-event distribution of the number of protons) on rapidity near mid-rapidity will change qualitatively if a critical point is passed in the scan. Hence, measuring the rapidity dependence of cumulant observables can enhance the prospect of discovering a critical point, in particular if it lies between two energies in the beam energy scan. |
hep-ph/0207120 | Ina Sarcevic | S. Jeon (RIKEN and McGill), J. Jalilian-Marian (BNL) and I. Sarcevic
(U of Arizona) | Large-$p_T$ Inclusive $\pi^0$ Production in Heavy-Ion Collisions at RHIC
and LHC | minor corrections, version accepted for publication in Nuclear
Physics A | Nucl.Phys. A723 (2003) 467-482 | 10.1016/S0375-9474(03)01447-7 | null | hep-ph nucl-th | null | We present results for the large-$p_T$ inclusive $\pi^0$ production in p-p
and A-A collisions at RHIC and LHC energies. We include the full
next-to-leading order radiative corrections, $O(\alpha_s^3)$, and nuclear
effects such as parton energy loss and nuclear shadowing. We find the
next-to-leading order corrections and the parton energy loss effect to be large
and $p_T$ dependent, while the nuclear shadowing effects are small ($< 10%$).
We calculate the ratio of prompt photons to neutral pions produced in heavy ion
collisions and show that at RHIC energies this ratio increases with $p_T$
approaching one at $p_T \sim 8$ GeV, due to the large suppression of $\pi^0$
production. We show that at the LHC, this ratio has a steep $p_T$ dependence
and approaches 25% effect at $p_T \sim 40$ GeV. We discuss theoretical
uncertainties inherent in our calculation, such as choice of the
renormalization, factorization and fragmentation scales and the K-factors which
signify the size of higher-order corrections.
| [
{
"created": "Tue, 9 Jul 2002 17:50:54 GMT",
"version": "v1"
},
{
"created": "Wed, 30 Apr 2003 02:03:42 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Jeon",
"S.",
"",
"RIKEN and McGill"
],
[
"Jalilian-Marian",
"J.",
"",
"BNL"
],
[
"Sarcevic",
"I.",
"",
"U of Arizona"
]
] | We present results for the large-$p_T$ inclusive $\pi^0$ production in p-p and A-A collisions at RHIC and LHC energies. We include the full next-to-leading order radiative corrections, $O(\alpha_s^3)$, and nuclear effects such as parton energy loss and nuclear shadowing. We find the next-to-leading order corrections and the parton energy loss effect to be large and $p_T$ dependent, while the nuclear shadowing effects are small ($< 10%$). We calculate the ratio of prompt photons to neutral pions produced in heavy ion collisions and show that at RHIC energies this ratio increases with $p_T$ approaching one at $p_T \sim 8$ GeV, due to the large suppression of $\pi^0$ production. We show that at the LHC, this ratio has a steep $p_T$ dependence and approaches 25% effect at $p_T \sim 40$ GeV. We discuss theoretical uncertainties inherent in our calculation, such as choice of the renormalization, factorization and fragmentation scales and the K-factors which signify the size of higher-order corrections. |
2003.03270 | Linda Shen | Linda Shen, J\"urgen Berges, Jan M. Pawlowski, Alexander Rothkopf | Thermalization and dynamical spectral properties in the quark-meson
model | null | Phys. Rev. D 102, 016012 (2020) | 10.1103/PhysRevD.102.016012 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the nonequilibrium evolution of the quark-meson model using
two-particle irreducible effective action techniques. Our numerical
simulations, which include the full dynamics of the order parameter of chiral
symmetry, show how the model thermalizes into different regions of its phase
diagram. In particular, by studying quark and meson spectral functions, we shed
light on the real-time dynamics approaching the crossover transition, revealing
e.g. the emergence of light effective fermionic degrees of freedom in the
infrared. At late times in the evolution, the fluctuation-dissipation relation
emerges naturally among both meson and quark degrees of freedom, confirming
that the simulation successfully reaches thermal equilibrium.
| [
{
"created": "Fri, 6 Mar 2020 15:16:15 GMT",
"version": "v1"
},
{
"created": "Sun, 2 Aug 2020 16:46:53 GMT",
"version": "v2"
}
] | 2020-08-04 | [
[
"Shen",
"Linda",
""
],
[
"Berges",
"Jürgen",
""
],
[
"Pawlowski",
"Jan M.",
""
],
[
"Rothkopf",
"Alexander",
""
]
] | We investigate the nonequilibrium evolution of the quark-meson model using two-particle irreducible effective action techniques. Our numerical simulations, which include the full dynamics of the order parameter of chiral symmetry, show how the model thermalizes into different regions of its phase diagram. In particular, by studying quark and meson spectral functions, we shed light on the real-time dynamics approaching the crossover transition, revealing e.g. the emergence of light effective fermionic degrees of freedom in the infrared. At late times in the evolution, the fluctuation-dissipation relation emerges naturally among both meson and quark degrees of freedom, confirming that the simulation successfully reaches thermal equilibrium. |
hep-ph/9506202 | Lee Kang Young | C. S. Kim, Jae Kwan Kim, Yeong Gyun Kim and Kang Young Lee | Form Factors for Exclusive Semileptonic $B$--Decays | 20 pages, RevTex, 2 ps figure files(uuencoded in seperate file) | null | null | KAIST-CHEP-95/04, YUMS 95-11, SNUTP 95-039 | hep-ph | null | We developed the new parton model approach for exclusive semileptonic decays
of $B$-meson to $D,~D^*$ by extending the inclusive parton model, and by
combining with the results of the HQET, motivated by Drell-Yan process. Without
the nearest pole dominance ans\"atze, we {\bf derived} the dependences of
hadronic form factors on $q^2$. We also calculated numerically the slope of the
Isgur-Wise function, which is consistent with the experimental results.
| [
{
"created": "Thu, 1 Jun 1995 17:48:22 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Kim",
"C. S.",
""
],
[
"Kim",
"Jae Kwan",
""
],
[
"Kim",
"Yeong Gyun",
""
],
[
"Lee",
"Kang Young",
""
]
] | We developed the new parton model approach for exclusive semileptonic decays of $B$-meson to $D,~D^*$ by extending the inclusive parton model, and by combining with the results of the HQET, motivated by Drell-Yan process. Without the nearest pole dominance ans\"atze, we {\bf derived} the dependences of hadronic form factors on $q^2$. We also calculated numerically the slope of the Isgur-Wise function, which is consistent with the experimental results. |
2006.11949 | Van Que Tran | Mingxuan Du, Jinhan Liang, Zuowei Liu, Van Que Tran and Yilun Xue | On-shell mediator dark matter models and the Xenon1T anomaly | 4 pages, 3 figures | null | 10.1088/1674-1137/abc244 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We present a dark matter model to explain the excess events in the electron
recoil data recently reported by the Xenon1T experiment. In our model, dark
matter $\chi$ annihilates into a pair of on-shell particles $\phi$ which
subsequently decay into $\psi \psi$ final state; $\psi$ interacts with electron
to generate the observed excess events. Due to the mass hierarchy, the velocity
of $\psi$ can be rather large and can have an extended distribution, which
provides a good fit to the electron recoil energy spectrum. We estimated the
flux of $\psi$ from dark matter annihilations in the galaxy and further
determined the interaction cross section which is sizable but small enough to
allow $\psi$ to penetrate the rocks to reach the underground labs.
| [
{
"created": "Mon, 22 Jun 2020 00:37:16 GMT",
"version": "v1"
}
] | 2021-02-03 | [
[
"Du",
"Mingxuan",
""
],
[
"Liang",
"Jinhan",
""
],
[
"Liu",
"Zuowei",
""
],
[
"Tran",
"Van Que",
""
],
[
"Xue",
"Yilun",
""
]
] | We present a dark matter model to explain the excess events in the electron recoil data recently reported by the Xenon1T experiment. In our model, dark matter $\chi$ annihilates into a pair of on-shell particles $\phi$ which subsequently decay into $\psi \psi$ final state; $\psi$ interacts with electron to generate the observed excess events. Due to the mass hierarchy, the velocity of $\psi$ can be rather large and can have an extended distribution, which provides a good fit to the electron recoil energy spectrum. We estimated the flux of $\psi$ from dark matter annihilations in the galaxy and further determined the interaction cross section which is sizable but small enough to allow $\psi$ to penetrate the rocks to reach the underground labs. |
0811.2888 | Gino Isidori | Riccardo Barbieri, Gino Isidori, Duccio Pappadopulo | Composite fermions in Electroweak Symmetry Breaking | 18 pages, 2 figures (v2: minor modifications, published version) | JHEP 0902:029,2009 | 10.1088/1126-6708/2009/02/029 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | If the electroweak symmetry is broken by some unspecified strong dynamics,
composite fermions may exist with definite transformation properties under
SU(2)_L x SU(2)_R/SU(2)_{L+R} and may play a role in giving masses by mixing to
all the standard quarks and leptons. Assuming this to be the case, we analyze
the role of Singlets, Doublets and Triplets in the ElectroWeak Precision Tests
and in Flavour Physics. Doublets and Triplets are generically disfavoured. In
the Singlet case, we specify the breaking patterns of the flavour group that
allow to keep the CKM picture of flavour physics and we discuss the effects of
the mixing between composite and elementary fermions. These mixings affect in
particular the rather peculiar LHC phenomenology of the composite fermions.
| [
{
"created": "Tue, 18 Nov 2008 11:26:51 GMT",
"version": "v1"
},
{
"created": "Wed, 11 Mar 2009 13:38:19 GMT",
"version": "v2"
}
] | 2010-02-22 | [
[
"Barbieri",
"Riccardo",
""
],
[
"Isidori",
"Gino",
""
],
[
"Pappadopulo",
"Duccio",
""
]
] | If the electroweak symmetry is broken by some unspecified strong dynamics, composite fermions may exist with definite transformation properties under SU(2)_L x SU(2)_R/SU(2)_{L+R} and may play a role in giving masses by mixing to all the standard quarks and leptons. Assuming this to be the case, we analyze the role of Singlets, Doublets and Triplets in the ElectroWeak Precision Tests and in Flavour Physics. Doublets and Triplets are generically disfavoured. In the Singlet case, we specify the breaking patterns of the flavour group that allow to keep the CKM picture of flavour physics and we discuss the effects of the mixing between composite and elementary fermions. These mixings affect in particular the rather peculiar LHC phenomenology of the composite fermions. |
1903.04542 | Miguel Nebot | Francisco J. Botella (Valencia U. and IFIC), Miguel Nebot (Lisbon IST
and CFTP) | CPT Violation in $\boldsymbol{B^0_s}$--$\boldsymbol{\bar B^0_s}$ mixing
and the measurement of CP Violation in $\boldsymbol{B_s\to K^+K^-}$ | 18 pages, 9 figures | null | null | CFTP/19-004, IFIC/19-15 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A simple analysis of time-dependent $B_s\to K^+K^-$ transitions, based on
recent results from the LHCb experiment, is presented. The benefits of adopting
a fully consistent theoretical description of the $B^0_s$--$\bar B^0_s$ mixing
are stressed. It is shown that bounds on CPT violation in the $B^0_s$--$\bar
B^0_s$ system can be consistently obtained and that direct CP violation in
$B_s\to K^+K^-$ can be robustly established, even in the presence of CPT
violation in the mixing.
| [
{
"created": "Mon, 11 Mar 2019 18:55:14 GMT",
"version": "v1"
}
] | 2019-03-13 | [
[
"Botella",
"Francisco J.",
"",
"Valencia U. and IFIC"
],
[
"Nebot",
"Miguel",
"",
"Lisbon IST\n and CFTP"
]
] | A simple analysis of time-dependent $B_s\to K^+K^-$ transitions, based on recent results from the LHCb experiment, is presented. The benefits of adopting a fully consistent theoretical description of the $B^0_s$--$\bar B^0_s$ mixing are stressed. It is shown that bounds on CPT violation in the $B^0_s$--$\bar B^0_s$ system can be consistently obtained and that direct CP violation in $B_s\to K^+K^-$ can be robustly established, even in the presence of CPT violation in the mixing. |
hep-ph/0106325 | Amol Dighe | Amol S. Dighe | Earth matter effects on the supernova neutrino spectra | 8 pages LaTeX, 2 eps figures, uses Rinton-P9x6.cls. Talk given at
CICHEP '2001, Cairo, Egypt, January 2001 | null | null | MPI-PhT/2001-19 | hep-ph | null | We explore the earth matter effects on the energy spectra of neutrinos from a
supernova. We show that the observations of the energy spectra of $\nu_e$ and
$\bar{\nu}_e$ from a galactic supernova may enable us to identify the solar
neutrino solution, to determine the sign of $\Delta m^2_{32}$, and to probe the
mixing matrix element $|U_{e3}|^2$ to values as low as $10^{-3}$. We point out
scenarios in which the matter effects can even be established through the
observation of the spectrum at a single detector.
| [
{
"created": "Thu, 28 Jun 2001 11:46:32 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Dighe",
"Amol S.",
""
]
] | We explore the earth matter effects on the energy spectra of neutrinos from a supernova. We show that the observations of the energy spectra of $\nu_e$ and $\bar{\nu}_e$ from a galactic supernova may enable us to identify the solar neutrino solution, to determine the sign of $\Delta m^2_{32}$, and to probe the mixing matrix element $|U_{e3}|^2$ to values as low as $10^{-3}$. We point out scenarios in which the matter effects can even be established through the observation of the spectrum at a single detector. |
hep-ph/9711336 | Roberto Pittau | Roberto Pittau (CERN) | Four-fermion production at LEP2 and NLC | 7 pages, talk given at International Europhysics Conference on
High-Energy Physics (HEP 97), Jerusalem, Israel, 19-26 Aug. 1997 | null | null | CERN-TH/97-327 | hep-ph | null | The present knowledge on four-fermion production in electron-positron
collisions is reviewed, with emphasis on W boson physics. Different methods to
extract M_W from the data are presented and the role of QCD loop corrections
discussed.
| [
{
"created": "Fri, 14 Nov 1997 16:48:07 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Pittau",
"Roberto",
"",
"CERN"
]
] | The present knowledge on four-fermion production in electron-positron collisions is reviewed, with emphasis on W boson physics. Different methods to extract M_W from the data are presented and the role of QCD loop corrections discussed. |
2303.16042 | Ivan Rosario | Manuel Masip, Ivan Rosario, Sergio J. Sciutto | Ultra-peripheral collisions of charged hadrons in extensive air showers | Version published in JCAP | null | 10.1088/1475-7516/2023/07/025 | null | hep-ph astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss the electromagnetic collisions of high energy protons, pions and
kaons with atmospheric nuclei. In particular, we use the equivalent photon
approximation to estimate (i) the diffractive collisions where the projectile
scatters inelastically off a nucleus, and (ii) the usual radiative processes
(bremsstrahlung, pair production and photonuclear interactions) of these
charged hadrons in the air. We then include the processes in the simulator
AIRES and study how they affect the longitudinal development of extensive air
showers. For $10^{9-11}$ GeV proton primaries we find that they introduce a
very small reduction (below 1%) in the average value of both $X_{\rm max}$ and
$\Delta X_{\rm max}$. At a given shower age (relative slant depth from $X_{\rm
max}$), these electromagnetic processes slightly increase the number of charged
particles at the shower maximum and reduce the number of muons when it is old,
decreasing by 1% the muon-to-($\gamma+e$) near the ground level. the
muon-to-(${\gamma} + e$) near the ground level.
| [
{
"created": "Tue, 28 Mar 2023 15:17:24 GMT",
"version": "v1"
},
{
"created": "Thu, 30 Mar 2023 15:43:31 GMT",
"version": "v2"
},
{
"created": "Thu, 7 Sep 2023 11:09:01 GMT",
"version": "v3"
}
] | 2023-09-08 | [
[
"Masip",
"Manuel",
""
],
[
"Rosario",
"Ivan",
""
],
[
"Sciutto",
"Sergio J.",
""
]
] | We discuss the electromagnetic collisions of high energy protons, pions and kaons with atmospheric nuclei. In particular, we use the equivalent photon approximation to estimate (i) the diffractive collisions where the projectile scatters inelastically off a nucleus, and (ii) the usual radiative processes (bremsstrahlung, pair production and photonuclear interactions) of these charged hadrons in the air. We then include the processes in the simulator AIRES and study how they affect the longitudinal development of extensive air showers. For $10^{9-11}$ GeV proton primaries we find that they introduce a very small reduction (below 1%) in the average value of both $X_{\rm max}$ and $\Delta X_{\rm max}$. At a given shower age (relative slant depth from $X_{\rm max}$), these electromagnetic processes slightly increase the number of charged particles at the shower maximum and reduce the number of muons when it is old, decreasing by 1% the muon-to-($\gamma+e$) near the ground level. the muon-to-(${\gamma} + e$) near the ground level. |
hep-ph/0002184 | Maksim L. Nekrasov | M. L. Nekrasov | Finite width effects and gauge cancellations in W- and Z-boson
production in framework of modified perturbation theory | 25 pages, 2 figures; minor changes in the text, version to appear in
Eur.Phys.J.C | Eur.Phys.J.C19:441-454,2001 | 10.1007/s100520100610 | null | hep-ph | null | The processes of production and subsequent decay of W- and Z-bosons in $e^+
e^-$ collisions are considered in a recently proposed modified perturbation
theory (PT), based on a direct expansion of probabilities instead of
amplitudes. In such an approach the non-integrable singularities in the phase
space, which are intrinsic in the conventional PT, appear as singularities in
the coupling constant (with subsequent compensation by the decay factors of
unstable particles). In the present paper the systematic investigation of the
modified PT is carried out. The results are compared with the results of the
conventional approach, based on calculation of the amplitude with Dyson
resummation. A solution to the problem of the loss of one-loop PT order in the
resonance region is found. On the basis of this solution the proof of gauge
cancellations in any order of the modified PT is given. A simple generalization
of the fermion-loop scheme is proposed which provides a complete description of
W-pair production in next-to-leading order approximation.
| [
{
"created": "Thu, 17 Feb 2000 16:21:59 GMT",
"version": "v1"
},
{
"created": "Mon, 5 Jun 2000 06:55:32 GMT",
"version": "v2"
},
{
"created": "Tue, 4 Jul 2000 10:12:40 GMT",
"version": "v3"
},
{
"created": "Wed, 18 Oct 2000 08:53:20 GMT",
"version": "v4"
},
{
"cre... | 2009-01-07 | [
[
"Nekrasov",
"M. L.",
""
]
] | The processes of production and subsequent decay of W- and Z-bosons in $e^+ e^-$ collisions are considered in a recently proposed modified perturbation theory (PT), based on a direct expansion of probabilities instead of amplitudes. In such an approach the non-integrable singularities in the phase space, which are intrinsic in the conventional PT, appear as singularities in the coupling constant (with subsequent compensation by the decay factors of unstable particles). In the present paper the systematic investigation of the modified PT is carried out. The results are compared with the results of the conventional approach, based on calculation of the amplitude with Dyson resummation. A solution to the problem of the loss of one-loop PT order in the resonance region is found. On the basis of this solution the proof of gauge cancellations in any order of the modified PT is given. A simple generalization of the fermion-loop scheme is proposed which provides a complete description of W-pair production in next-to-leading order approximation. |
hep-ph/0301166 | Petja Salmi | P. Salmi, R. Kinnunen, and N. Stepanov | Prospects of Detecting Massive Charged Higgs from Hadronic Decay H -> tb
in CMS | 13 pages, 18 figures | null | null | CMS Note 2002/024 | hep-ph | null | The possibility to detect the massive charged Higgs boson H using the
hadronic decay channel H -> tb in the associated production pp -> tH + X in the
CMS experiment at LHC is studied. There is a large background from ttbb events
which makes the observation difficult. Detection of a Higgs signal in this
channel requires an excellent b-tagging performance. Good calorimeter mass
resolution is also necessary for the full event reconstruction.
| [
{
"created": "Mon, 20 Jan 2003 20:48:21 GMT",
"version": "v1"
},
{
"created": "Mon, 20 Jan 2003 21:19:28 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Salmi",
"P.",
""
],
[
"Kinnunen",
"R.",
""
],
[
"Stepanov",
"N.",
""
]
] | The possibility to detect the massive charged Higgs boson H using the hadronic decay channel H -> tb in the associated production pp -> tH + X in the CMS experiment at LHC is studied. There is a large background from ttbb events which makes the observation difficult. Detection of a Higgs signal in this channel requires an excellent b-tagging performance. Good calorimeter mass resolution is also necessary for the full event reconstruction. |
hep-ph/0605338 | Emerson Luna | E.G.S. Luna, A.A. Natale and C.M. Zanetti | The small $x$ behavior of the gluon structure function from total cross
sections | 19 pages, 3 figures; revised version; to appear in Int. J. Mod. Phys.
A | Int.J.Mod.Phys.A23:151-165,2008 | 10.1142/S0217751X08038019 | null | hep-ph | null | Within a QCD-based eikonal model with a dynamical infrared gluon mass scale
we discuss how the small $x$ behavior of the gluon distribution function at
moderate $Q^{2}$ is directly related to the rise of total hadronic cross
sections. In this model the rise of total cross sections is driven by
gluon-gluon semihard scattering processes, where the behavior of the small $x$
gluon distribution function exhibits the power law $xg(x,Q^2)=
h(Q^2)x^{-\epsilon}$. Assuming that the $Q^{2}$ scale is proportional to the
dynamical gluon mass one, we show that the values of $h(Q^2)$ obtained in this
model are compatible with an earlier result based on a specific nonperturbative
Pomeron model. We discuss the implications of this picture for the behavior of
input valence-like gluon distributions at low resolution scales.
| [
{
"created": "Wed, 31 May 2006 16:53:29 GMT",
"version": "v1"
},
{
"created": "Wed, 29 Aug 2007 16:17:24 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Luna",
"E. G. S.",
""
],
[
"Natale",
"A. A.",
""
],
[
"Zanetti",
"C. M.",
""
]
] | Within a QCD-based eikonal model with a dynamical infrared gluon mass scale we discuss how the small $x$ behavior of the gluon distribution function at moderate $Q^{2}$ is directly related to the rise of total hadronic cross sections. In this model the rise of total cross sections is driven by gluon-gluon semihard scattering processes, where the behavior of the small $x$ gluon distribution function exhibits the power law $xg(x,Q^2)= h(Q^2)x^{-\epsilon}$. Assuming that the $Q^{2}$ scale is proportional to the dynamical gluon mass one, we show that the values of $h(Q^2)$ obtained in this model are compatible with an earlier result based on a specific nonperturbative Pomeron model. We discuss the implications of this picture for the behavior of input valence-like gluon distributions at low resolution scales. |
hep-ph/9806345 | Stefano Forte | Guido Altarelli, Stefano Forte and Giovanni Ridolfi | On positivity of parton distributions | 20 pages, 8 figures included by epsf, plain tex with harvmac;
REVISION: missing factor of 1/x in Eq 2.13 added, missing factor 2 mutiplying
ln x in Eq.(4.14) added | Nucl.Phys. B534 (1998) 277-296 | 10.1016/S0550-3213(98)00661-0 | CERN-TH/98-156, DFTT 28/98, GeF-TH-6/98 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss the bounds on polarized parton distributions which follow from
their definition in terms of cross section asymmetries. We spell out how the
bounds obtained in the naive parton model can be derived within perturbative
QCD at leading order when all quark and gluon distributions are defined in
terms of suitable physical processes. We specify a convenient physical
definition for the polarized and unpolarized gluon distributions in terms of
Higgs production from gluon fusion. We show that these bounds are modified by
subleading corrections, and we determine them up to NLO. We examine the ensuing
phenomenological implications, in particular in view of the determination of
the polarized gluon distribution.
| [
{
"created": "Thu, 11 Jun 1998 14:36:46 GMT",
"version": "v1"
},
{
"created": "Wed, 13 Dec 2023 12:53:58 GMT",
"version": "v2"
}
] | 2023-12-14 | [
[
"Altarelli",
"Guido",
""
],
[
"Forte",
"Stefano",
""
],
[
"Ridolfi",
"Giovanni",
""
]
] | We discuss the bounds on polarized parton distributions which follow from their definition in terms of cross section asymmetries. We spell out how the bounds obtained in the naive parton model can be derived within perturbative QCD at leading order when all quark and gluon distributions are defined in terms of suitable physical processes. We specify a convenient physical definition for the polarized and unpolarized gluon distributions in terms of Higgs production from gluon fusion. We show that these bounds are modified by subleading corrections, and we determine them up to NLO. We examine the ensuing phenomenological implications, in particular in view of the determination of the polarized gluon distribution. |
hep-ph/0207216 | Uleshchenko V. V. ofti off 337 fon | A. Szczurek | Pion-pion scattering above resonances | A talk presented at the MESON2002, 7th International Workshop on
Production, Properties and Interactions of Mesons; Cracow, Poland, 24-28 May
2002 | null | 10.1142/9789812791351_0049 | null | hep-ph nucl-th | null | We model large angle intermediate energy pion-pion scattering by the pQCD
two-gluon (2g) exchange contribution and discuss the onset of the dominance of
the Glauber-Gribov-Landshoff (GGL) component. The pQCD 2g exchange contribution
becomes substantial already at $|t|\sim$ 1 GeV^{2}, but the pQCD exchange
dominance is deferred to $|t|\sim$ 3 GeV^{2} because of competing multiple soft
rescattering effects. Based on the NN and $\pi N$ total cross section data and
Regge factorization, we evaluate the dominant soft contribution to the $\pi
\pi$ total cross section and find the results consistent with the ones deduced
earlier from the absorption model analysis of the $\pi N \to X N, X \Delta$
data.
| [
{
"created": "Thu, 18 Jul 2002 09:01:31 GMT",
"version": "v1"
}
] | 2017-08-23 | [
[
"Szczurek",
"A.",
""
]
] | We model large angle intermediate energy pion-pion scattering by the pQCD two-gluon (2g) exchange contribution and discuss the onset of the dominance of the Glauber-Gribov-Landshoff (GGL) component. The pQCD 2g exchange contribution becomes substantial already at $|t|\sim$ 1 GeV^{2}, but the pQCD exchange dominance is deferred to $|t|\sim$ 3 GeV^{2} because of competing multiple soft rescattering effects. Based on the NN and $\pi N$ total cross section data and Regge factorization, we evaluate the dominant soft contribution to the $\pi \pi$ total cross section and find the results consistent with the ones deduced earlier from the absorption model analysis of the $\pi N \to X N, X \Delta$ data. |
0903.3115 | Sannino Francesco | Matti Jarvinen, Thomas A. Ryttov, Francesco Sannino | The Electroweak Phase Transition in Ultra Minimal Technicolor | 38 RevTeX pages, 9 figures | Phys.Rev.D79:095008,2009 | 10.1103/PhysRevD.79.095008 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We unveil the temperature-dependent electroweak phase transition in new
extensions of the Standard Model in which the electroweak symmetry is
spontaneously broken via strongly coupled, nearly-conformal dynamics achieved
by the means of multiple matter representations. In particular, we focus on the
low energy effective theory introduced to describe Ultra Minimal Walking
Technicolor at the phase transition. Using the one-loop effective potential
with ring improvement, we identify regions of parameter space which yield a
strong first order transition. A striking feature of the model is the existence
of a second phase transition associated to the electroweak-singlet sector. The
interplay between these two transitions leads to an extremely rich phase
diagram.
| [
{
"created": "Wed, 18 Mar 2009 09:44:35 GMT",
"version": "v1"
}
] | 2009-08-12 | [
[
"Jarvinen",
"Matti",
""
],
[
"Ryttov",
"Thomas A.",
""
],
[
"Sannino",
"Francesco",
""
]
] | We unveil the temperature-dependent electroweak phase transition in new extensions of the Standard Model in which the electroweak symmetry is spontaneously broken via strongly coupled, nearly-conformal dynamics achieved by the means of multiple matter representations. In particular, we focus on the low energy effective theory introduced to describe Ultra Minimal Walking Technicolor at the phase transition. Using the one-loop effective potential with ring improvement, we identify regions of parameter space which yield a strong first order transition. A striking feature of the model is the existence of a second phase transition associated to the electroweak-singlet sector. The interplay between these two transitions leads to an extremely rich phase diagram. |
2007.12700 | Lohan Sartore | Lohan Sartore, Ingo Schienbein | PyR@TE 3 | Version accepted in CPC. 31 pages, 3 tables. The code can be
downloaded from https://github.com/LSartore/pyrate | null | 10.1016/j.cpc.2020.107819 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a new version of PyR@TE, a Python tool for the computation of
renormalization group equations for general, non-supersymmetric gauge theories.
Its new core relies on a recent paper by Poole & Thomsen (arXiv:1906.04625) to
compute the $\beta$-functions. In this framework, gauge kinetic mixing is
naturally implemented, and the Weyl consistency relations between gauge,
quartic and Yukawa couplings are automatically satisfied. One of the main new
features is the possibility for the user to compute the gauge coupling
$\beta$-functions up to the three-loop order. Large parts of the PyR@TE code
have been rewritten and improved, including the group theory module PyLie. As a
result, the overall performance in terms of computation speed was drastically
improved and the model file is more flexible and user-friendly.
| [
{
"created": "Fri, 24 Jul 2020 18:00:01 GMT",
"version": "v1"
},
{
"created": "Wed, 13 Jan 2021 09:43:11 GMT",
"version": "v2"
}
] | 2021-01-14 | [
[
"Sartore",
"Lohan",
""
],
[
"Schienbein",
"Ingo",
""
]
] | We present a new version of PyR@TE, a Python tool for the computation of renormalization group equations for general, non-supersymmetric gauge theories. Its new core relies on a recent paper by Poole & Thomsen (arXiv:1906.04625) to compute the $\beta$-functions. In this framework, gauge kinetic mixing is naturally implemented, and the Weyl consistency relations between gauge, quartic and Yukawa couplings are automatically satisfied. One of the main new features is the possibility for the user to compute the gauge coupling $\beta$-functions up to the three-loop order. Large parts of the PyR@TE code have been rewritten and improved, including the group theory module PyLie. As a result, the overall performance in terms of computation speed was drastically improved and the model file is more flexible and user-friendly. |
1003.3926 | Werner Bernreuther | Werner Bernreuther, Zong-Guo Si | Distributions and correlations for top quark pair production and decay
at the Tevatron and LHC. | Latex, 39 pages, 39 figures, 4 tables | Nucl.Phys.B837:90-121,2010 | 10.1016/j.nuclphysb.2010.05.001 | TTK-10-22 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate a number of observables that are and will be instrumental in
the exploration of $\tbart$ production and decay at the Tevatron and the LHC.
For this analysis we made a computer program that incorporates besides the NLO
QCD corrections to $\tbart$ production and decay also mixed weak-QCD
corrections to the production amplitudes, and that allows for studies of
correlated versus uncorrelated $\tbart$ events. In this paper we analyze and
compute observables mostly for dileptonic $\tbart$ final states to
next-to-leading order in the strong and weak gauge couplings (NLOW), with
selection cuts. We calculate charge asymmetries of the top quark and of
$\ell=e,\mu$ and we compare, where possible, with experimental results. We show
that top-quark spin correlations affect a leptonic pair asymmetry (which has
not been measured so far) by $\sim 7%$. We determine several dileptonic angular
correlations, which reflect $\tbart$ spin correlations, namely the beam,
off-diagonal and helicity correlation, and the opening angle distribution
(defined in the $t$, $\bar t$ rest frames) when selection cuts are applied. Our
NLOW predictions for the beam, off-diagonal, and helicity correlation for the
Tevatron agree with recent measurements by the CDF and D0 experiments. In
addition we make predictions for estimators of these correlations as functions
of $\mtt$. These estimators may prove useful for the Tevatron and also in the
early rounds of LHC data-analyses, where the event numbers will probably not be
abundant. Furthermore, we compute to NLOW in the gauge couplings two dilepton
angular correlations that are defined in the laboratory frame, for correlated
and uncorrelated $\tbart$ events at the LHC. Finally, based on our SM results,
we identify several observables that allow to search for non-standard parity-
and CP-violating interactions, especially with future LHC data.
| [
{
"created": "Sat, 20 Mar 2010 12:27:05 GMT",
"version": "v1"
}
] | 2014-11-20 | [
[
"Bernreuther",
"Werner",
""
],
[
"Si",
"Zong-Guo",
""
]
] | We investigate a number of observables that are and will be instrumental in the exploration of $\tbart$ production and decay at the Tevatron and the LHC. For this analysis we made a computer program that incorporates besides the NLO QCD corrections to $\tbart$ production and decay also mixed weak-QCD corrections to the production amplitudes, and that allows for studies of correlated versus uncorrelated $\tbart$ events. In this paper we analyze and compute observables mostly for dileptonic $\tbart$ final states to next-to-leading order in the strong and weak gauge couplings (NLOW), with selection cuts. We calculate charge asymmetries of the top quark and of $\ell=e,\mu$ and we compare, where possible, with experimental results. We show that top-quark spin correlations affect a leptonic pair asymmetry (which has not been measured so far) by $\sim 7%$. We determine several dileptonic angular correlations, which reflect $\tbart$ spin correlations, namely the beam, off-diagonal and helicity correlation, and the opening angle distribution (defined in the $t$, $\bar t$ rest frames) when selection cuts are applied. Our NLOW predictions for the beam, off-diagonal, and helicity correlation for the Tevatron agree with recent measurements by the CDF and D0 experiments. In addition we make predictions for estimators of these correlations as functions of $\mtt$. These estimators may prove useful for the Tevatron and also in the early rounds of LHC data-analyses, where the event numbers will probably not be abundant. Furthermore, we compute to NLOW in the gauge couplings two dilepton angular correlations that are defined in the laboratory frame, for correlated and uncorrelated $\tbart$ events at the LHC. Finally, based on our SM results, we identify several observables that allow to search for non-standard parity- and CP-violating interactions, especially with future LHC data. |
hep-ph/0409031 | Abdelkader-Salim Safir | A. Salim Safir (Munich U.) | Non-leptonic B-decays, CP violation & the UT | 4 pages; 4 figures (requires epsfig, psfrag); To appear in the
proceedings of the 11th International Conference on Quantum Chromodynamics
(QCD 04), Montpellier, France, 5--10th July 2004 | Nucl.Phys.Proc.Suppl.152:154-157,2006 | 10.1016/j.nuclphysbps.2005.08.029 | LMU 11/04 | hep-ph | null | We study the implication of the time-dependent CP asymmetry in
$B\to\pi^+\pi^-$ decays on the extraction of weak phases taking into account
the precise measurement of $\sin 2\beta$, obtained from the ``gold-plated''mode
$B\to J/\psi K_S$. Predictions and uncertainties for the hadronic parameters
are investigated in QCD factorization. Furthermore, independent theoretical and
experimental tests of the factorization framework are briefly discussed.
Finally, a model-independent bound on the unitarity triangle from CP violation
in $B\to\pi^+\pi^-$ and $B\to J/\psi K_S$ is derived.
| [
{
"created": "Fri, 3 Sep 2004 08:56:29 GMT",
"version": "v1"
}
] | 2010-11-23 | [
[
"Safir",
"A. Salim",
"",
"Munich U."
]
] | We study the implication of the time-dependent CP asymmetry in $B\to\pi^+\pi^-$ decays on the extraction of weak phases taking into account the precise measurement of $\sin 2\beta$, obtained from the ``gold-plated''mode $B\to J/\psi K_S$. Predictions and uncertainties for the hadronic parameters are investigated in QCD factorization. Furthermore, independent theoretical and experimental tests of the factorization framework are briefly discussed. Finally, a model-independent bound on the unitarity triangle from CP violation in $B\to\pi^+\pi^-$ and $B\to J/\psi K_S$ is derived. |
0903.4042 | Sergey Troshin | S.M. Troshin | Note on inconsistency of unitarity saturation and maximal odderon | 5 pages, revised version, text modified, reference added, results
unchanged | Phys.Lett.B682:40-42,2009 | 10.1016/j.physletb.2009.10.088 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | It is shown that regime of elastic scattering with maximal odderon
contribution is not compatible with unitarity and black disk limits saturation.
| [
{
"created": "Tue, 24 Mar 2009 09:16:40 GMT",
"version": "v1"
},
{
"created": "Tue, 15 Sep 2009 06:39:54 GMT",
"version": "v2"
}
] | 2010-04-23 | [
[
"Troshin",
"S. M.",
""
]
] | It is shown that regime of elastic scattering with maximal odderon contribution is not compatible with unitarity and black disk limits saturation. |
1110.1453 | Sven Bjarke Gudnason | Roberto Auzzi, Amit Giveon, Sven Bjarke Gudnason | Mediation of Supersymmetry Breaking in Quivers | LaTeX, 30 pages, 8 figures | JHEP 1112:016,2011 | 10.1007/JHEP12(2011)016 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The soft masses due to SUSY breaking, mediated by gauge fields, are computed
for generic matter in quiver gauge theories.
| [
{
"created": "Fri, 7 Oct 2011 08:21:02 GMT",
"version": "v1"
}
] | 2011-12-20 | [
[
"Auzzi",
"Roberto",
""
],
[
"Giveon",
"Amit",
""
],
[
"Gudnason",
"Sven Bjarke",
""
]
] | The soft masses due to SUSY breaking, mediated by gauge fields, are computed for generic matter in quiver gauge theories. |
2305.02270 | Giovanni Antonio Chirilli | Giovanni Antonio Chirilli | Pseudo and quasi quark PDF in the BFKL approximation | 41 pages, 14 figures; results added, appendix extended, typos
corrected; it matches the version published in JHEP | null | null | null | hep-ph hep-lat hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | I examine the high-energy behavior of the Ioffe-time distribution for the
quark bi-local space-like separated operator using the high-energy operator
product expansion. These findings have significant implications for lattice
calculations, which require extrapolation for large Ioffe-time values. I
perform an explicit Fourier transform for both the pseudo-PDF and quasi-PDF,
and investigate their behavior within the first two leading twist
contributions.
I show that the quark pseudo-PDF captures the BFKL resummation (resummation
of all twists) and exhibits a rising behavior for small $x_B$ values, while the
quasi-PDF presents a different behavior. I demonstrate that an appropriate
small-$x_B$ behavior cannot be achieved solely through DGLAP dynamics,
emphasizing the importance of all-twist resummation. This study provides
valuable insights into quark non-local operators' high-energy behavior and the
limitations of lattice calculations in this context.
| [
{
"created": "Wed, 3 May 2023 17:01:56 GMT",
"version": "v1"
},
{
"created": "Wed, 10 May 2023 17:58:49 GMT",
"version": "v2"
},
{
"created": "Wed, 5 Jul 2023 15:49:34 GMT",
"version": "v3"
}
] | 2023-07-06 | [
[
"Chirilli",
"Giovanni Antonio",
""
]
] | I examine the high-energy behavior of the Ioffe-time distribution for the quark bi-local space-like separated operator using the high-energy operator product expansion. These findings have significant implications for lattice calculations, which require extrapolation for large Ioffe-time values. I perform an explicit Fourier transform for both the pseudo-PDF and quasi-PDF, and investigate their behavior within the first two leading twist contributions. I show that the quark pseudo-PDF captures the BFKL resummation (resummation of all twists) and exhibits a rising behavior for small $x_B$ values, while the quasi-PDF presents a different behavior. I demonstrate that an appropriate small-$x_B$ behavior cannot be achieved solely through DGLAP dynamics, emphasizing the importance of all-twist resummation. This study provides valuable insights into quark non-local operators' high-energy behavior and the limitations of lattice calculations in this context. |
1608.03651 | YaBing Zuo | Yabing Zuo, Yue Hu, Linlin He, Wei Yang, Yan Chen, Yannan Hao | $D \rightarrow a_1, f_1$ transition form factors and semileptonic decays
via 3-point QCD sum rules | 14 pages, 13 figures | Int.J.Mod.Phys.A31,1650116(2016) | 10.1142/S0217751X16501165 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | By using the 3-point QCD sum rules, we calculate the transition form factors
of $D$ decays into the spin triplet axial vector mesons $a_1(1260)$, $f_1(1285)
$, $f_1(1420)$. In the calculations, we consider the quark contents of each
meson in detail. In view of the fact that the isospin of $a_1(1260)$ is one, we
calculate the $D^+ \rightarrow a_1^0 (1260)$ and $D^0 \rightarrow a_1^- (1260)$
transition form factors separately. In the case of $ f_1(1285), f_1(1420)$, the
mixing between light flavor $SU(3)$ singlet and octet is taken into account.
Based on the form factors obtained here, we give predictions for the branching
ratios of relevant semileptonic decays, which can be tested in the future
experiments.
| [
{
"created": "Fri, 12 Aug 2016 01:25:39 GMT",
"version": "v1"
}
] | 2016-08-15 | [
[
"Zuo",
"Yabing",
""
],
[
"Hu",
"Yue",
""
],
[
"He",
"Linlin",
""
],
[
"Yang",
"Wei",
""
],
[
"Chen",
"Yan",
""
],
[
"Hao",
"Yannan",
""
]
] | By using the 3-point QCD sum rules, we calculate the transition form factors of $D$ decays into the spin triplet axial vector mesons $a_1(1260)$, $f_1(1285) $, $f_1(1420)$. In the calculations, we consider the quark contents of each meson in detail. In view of the fact that the isospin of $a_1(1260)$ is one, we calculate the $D^+ \rightarrow a_1^0 (1260)$ and $D^0 \rightarrow a_1^- (1260)$ transition form factors separately. In the case of $ f_1(1285), f_1(1420)$, the mixing between light flavor $SU(3)$ singlet and octet is taken into account. Based on the form factors obtained here, we give predictions for the branching ratios of relevant semileptonic decays, which can be tested in the future experiments. |
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