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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0906.4335 | Urs Wiedemann A | Svend Domdey, Hans-Jurgen Pirner, Urs Achim Wiedemann | Testing the Scale Dependence of the Scale Factor in Double Dijet
Production at the LHC | null | Eur.Phys.J.C65:153-162,2010 | 10.1140/epjc/s10052-009-1198-5 | CERN-PH-TH/2009-059 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The scale factor is the effective cross section used to characterize the
measured rate of inclusive double dijet production in high energy hadron
collisions. It is sensitive to the two-parton distributions in the hadronic
projectile. In principle, the scale factor depends on the center of mass energy
and on the minimal transverse energy of the jets contributing to the double
dijet cross section. Here, we point out that proton-proton collisions at the
LHC will provide for the first time experimental access to these scale
dependences in a logarithmically wide, nominally perturbative kinematic range
of minimal transverse energy between 10 GeV and 100 GeV. This constrains the
dependence of two-parton distribution functions on parton momentum fractions
and parton localization in impact parameter space. Novel information is to be
expected about the transverse growth of hadronic distribution functions in the
range of semi-hard Bjorken x (0.001 < x < 0.1) and high resolution Q^2. We
discuss to what extent one can disentangle different pictures of the
$x$-evolution of two-parton distributions in the transverse plane by measuring
double-hard scattering events at the LHC.
| [
{
"created": "Tue, 23 Jun 2009 20:31:09 GMT",
"version": "v1"
}
] | 2010-01-06 | [
[
"Domdey",
"Svend",
""
],
[
"Pirner",
"Hans-Jurgen",
""
],
[
"Wiedemann",
"Urs Achim",
""
]
] | The scale factor is the effective cross section used to characterize the measured rate of inclusive double dijet production in high energy hadron collisions. It is sensitive to the two-parton distributions in the hadronic projectile. In principle, the scale factor depends on the center of mass energy and on the minimal transverse energy of the jets contributing to the double dijet cross section. Here, we point out that proton-proton collisions at the LHC will provide for the first time experimental access to these scale dependences in a logarithmically wide, nominally perturbative kinematic range of minimal transverse energy between 10 GeV and 100 GeV. This constrains the dependence of two-parton distribution functions on parton momentum fractions and parton localization in impact parameter space. Novel information is to be expected about the transverse growth of hadronic distribution functions in the range of semi-hard Bjorken x (0.001 < x < 0.1) and high resolution Q^2. We discuss to what extent one can disentangle different pictures of the $x$-evolution of two-parton distributions in the transverse plane by measuring double-hard scattering events at the LHC. |
hep-ph/9408255 | null | Kari Enqvist, A.I. Rez and V.V. Semikoz | Dirac Neutrinos and Primordial Magnetic Fields | 17 pages, HU-TFT-94-26 | Nucl.Phys.B436:49-64,1995 | 10.1016/0550-3213(94)00506-A | null | hep-ph | null | We consider random primordial magnetic fields and discuss their dissipation,
coherence length $L_0$, scaling behaviour and constraints implied by the
primoridal nucleosynthesis. Such magnetic fields could excite the
right-helicity states of Dirac neutrinos, with adverse consequences for
nucleosynthesis. We present solutions to the spin kinetic equation of a Dirac
neutrino traversing a random magnetic field in the cases of large and small
$L_0$, taking also into account elastic collisions. Depending on the scaling
behaviour and on the magnetic coherence length, the lower limit on the neutrino
magnetic moment thus obtained could be as severe as $10^{-20}\mu_B$.
| [
{
"created": "Tue, 9 Aug 1994 10:45:28 GMT",
"version": "v1"
}
] | 2011-07-19 | [
[
"Enqvist",
"Kari",
""
],
[
"Rez",
"A. I.",
""
],
[
"Semikoz",
"V. V.",
""
]
] | We consider random primordial magnetic fields and discuss their dissipation, coherence length $L_0$, scaling behaviour and constraints implied by the primoridal nucleosynthesis. Such magnetic fields could excite the right-helicity states of Dirac neutrinos, with adverse consequences for nucleosynthesis. We present solutions to the spin kinetic equation of a Dirac neutrino traversing a random magnetic field in the cases of large and small $L_0$, taking also into account elastic collisions. Depending on the scaling behaviour and on the magnetic coherence length, the lower limit on the neutrino magnetic moment thus obtained could be as severe as $10^{-20}\mu_B$. |
hep-ph/0512194 | Sean Fleming | Sean Fleming (University of Arizona) Adam K. Leibovich (University of
Pittsburgh) Thomas Mehen (Duke University) | J/psi Photo-production at Large z in Soft Collinear Effective Theory | 12 Pages, 3 figures. Presented at the Ringberg Workshop: New Trends
in HERA Physics 2005 | null | 10.1142/9789812773524_0022 | null | hep-ph | null | One of the outstanding problems in J/\psi physics is a systematic
understanding of the differential photo-production cross section
dsigma/dz(gamma + p -> J/psi + X), where z= E_psi/E_gamma in the proton rest
frame. The theoretical prediction based on the non-relativistic QCD (NRQCD)
factorization formalism has a color-octet contribution which grows rapidly in
the endpoint region, z -> 1, spoiling perturbation theory. In addition there
are subleading operators which are enhanced by powers of 1/(1-z) and they must
be resummed to all orders. Here an update of a systematic analysis is
presented. The approach used to organize the endpoint behavior of the
photo-production cross section is based on a combination of NRQCD and soft
collinear effective theory. While a final result is not yet available, an
intermediate result indicates that better agreement between theory and data
will be achieved in this framework.
| [
{
"created": "Thu, 15 Dec 2005 05:18:51 GMT",
"version": "v1"
}
] | 2017-08-23 | [
[
"Fleming",
"Sean",
"",
"University of Arizona"
],
[
"Leibovich",
"Adam K.",
"",
"University of\n Pittsburgh"
],
[
"Mehen",
"Thomas",
"",
"Duke University"
]
] | One of the outstanding problems in J/\psi physics is a systematic understanding of the differential photo-production cross section dsigma/dz(gamma + p -> J/psi + X), where z= E_psi/E_gamma in the proton rest frame. The theoretical prediction based on the non-relativistic QCD (NRQCD) factorization formalism has a color-octet contribution which grows rapidly in the endpoint region, z -> 1, spoiling perturbation theory. In addition there are subleading operators which are enhanced by powers of 1/(1-z) and they must be resummed to all orders. Here an update of a systematic analysis is presented. The approach used to organize the endpoint behavior of the photo-production cross section is based on a combination of NRQCD and soft collinear effective theory. While a final result is not yet available, an intermediate result indicates that better agreement between theory and data will be achieved in this framework. |
1004.4117 | Guido Bell | G. Bell, J.H. Kuhn and J. Rittinger | Electroweak Sudakov Logarithms and Real Gauge-Boson Radiation in the TeV
Region | 20 pages, 4 figures | Eur.Phys.J.C70:659-671,2010 | 10.1140/epjc/s10052-010-1489-x | TTP10-22 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Electroweak radiative corrections give rise to large negative,
double-logarithmically enhanced corrections in the TeV region. These are partly
compensated by real radiation and, moreover, affected by selecting
isospin-noninvariant external states. We investigate the impact of real gauge
boson radiation more quantitatively by considering different restricted final
state configurations. We consider successively a massive abelian gauge theory,
a spontaneously broken SU(2) theory and the electroweak Standard Model. We find
that details of the choice of the phase space cuts, in particular whether a
fraction of collinear and soft radiation is included, have a strong impact on
the relative amount of real and virtual corrections.
| [
{
"created": "Fri, 23 Apr 2010 12:39:17 GMT",
"version": "v1"
}
] | 2010-12-15 | [
[
"Bell",
"G.",
""
],
[
"Kuhn",
"J. H.",
""
],
[
"Rittinger",
"J.",
""
]
] | Electroweak radiative corrections give rise to large negative, double-logarithmically enhanced corrections in the TeV region. These are partly compensated by real radiation and, moreover, affected by selecting isospin-noninvariant external states. We investigate the impact of real gauge boson radiation more quantitatively by considering different restricted final state configurations. We consider successively a massive abelian gauge theory, a spontaneously broken SU(2) theory and the electroweak Standard Model. We find that details of the choice of the phase space cuts, in particular whether a fraction of collinear and soft radiation is included, have a strong impact on the relative amount of real and virtual corrections. |
2107.01864 | Yan-Qing Ma | Xiao Liu, Yan-Qing Ma | Multiloop corrections for collider processes using auxiliary mass flow | 7 pages, 4 figures, published version | Phys.Rev.D 105 (2022) 5, L051503 | 10.1103/PhysRevD.105.L051503 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | With a key improvement, the auxiliary mass flow method is now able to compute
Feynman integrals encountered in cutting-edge collider processes. We have
successfully applied it to compute some integrals involved in two-loop
electroweak corrections to $e^+e^-\to HZ$, two-loop QCD corrections to $3j$,
$W/Z/H+2j$, $t\bar{t}H$ and $4j$ production at hadron colliders, and three-loop
QCD corrections to $t\bar{t}$ production at hadron colliders, all of which are
crucial for precision frontier in collider physics in the following decade. Our
results are important building blocks and benchmarks for future studies of
these processes.
| [
{
"created": "Mon, 5 Jul 2021 08:34:32 GMT",
"version": "v1"
},
{
"created": "Tue, 15 Mar 2022 11:57:40 GMT",
"version": "v2"
}
] | 2022-03-16 | [
[
"Liu",
"Xiao",
""
],
[
"Ma",
"Yan-Qing",
""
]
] | With a key improvement, the auxiliary mass flow method is now able to compute Feynman integrals encountered in cutting-edge collider processes. We have successfully applied it to compute some integrals involved in two-loop electroweak corrections to $e^+e^-\to HZ$, two-loop QCD corrections to $3j$, $W/Z/H+2j$, $t\bar{t}H$ and $4j$ production at hadron colliders, and three-loop QCD corrections to $t\bar{t}$ production at hadron colliders, all of which are crucial for precision frontier in collider physics in the following decade. Our results are important building blocks and benchmarks for future studies of these processes. |
2105.03218 | Nicolas Kovensky | Nicolas Kovensky and Andreas Schmitt | Isospin asymmetry in holographic baryonic matter | 53 pages, 8 figures, v2: minor improvements in the text, format
adapted to SciPost Physics; v3: typos in Eqs.(20) and (30c) corrected | SciPost Phys. 11, 029 (2021) | 10.21468/SciPostPhys.11.2.029 | null | hep-ph hep-th nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study baryonic matter with isospin asymmetry, including fully dynamically
its interplay with pion condensation. To this end, we employ the holographic
Witten-Sakai-Sugimoto model and the so-called homogeneous ansatz for the gauge
fields in the bulk to describe baryonic matter. Within the confined geometry
and restricting ourselves to the chiral limit, we map out the phase structure
in the presence of baryon and isospin chemical potentials, showing that for
sufficiently large chemical potentials condensed pions and isospin-asymmetric
baryonic matter coexist. We also present first results of the same approach in
the deconfined geometry and demonstrate that this case, albeit technically more
involved, is better suited for comparisons with and predictions for real-world
QCD. Our study lays the ground for future improved holographic studies aiming
towards a realistic description of charge neutral, beta-equilibrated matter in
compact stars, and also for more refined comparisons with lattice studies at
nonzero isospin chemical potential.
| [
{
"created": "Fri, 7 May 2021 12:44:59 GMT",
"version": "v1"
},
{
"created": "Mon, 12 Jul 2021 16:31:03 GMT",
"version": "v2"
},
{
"created": "Mon, 28 Feb 2022 16:36:07 GMT",
"version": "v3"
}
] | 2022-03-01 | [
[
"Kovensky",
"Nicolas",
""
],
[
"Schmitt",
"Andreas",
""
]
] | We study baryonic matter with isospin asymmetry, including fully dynamically its interplay with pion condensation. To this end, we employ the holographic Witten-Sakai-Sugimoto model and the so-called homogeneous ansatz for the gauge fields in the bulk to describe baryonic matter. Within the confined geometry and restricting ourselves to the chiral limit, we map out the phase structure in the presence of baryon and isospin chemical potentials, showing that for sufficiently large chemical potentials condensed pions and isospin-asymmetric baryonic matter coexist. We also present first results of the same approach in the deconfined geometry and demonstrate that this case, albeit technically more involved, is better suited for comparisons with and predictions for real-world QCD. Our study lays the ground for future improved holographic studies aiming towards a realistic description of charge neutral, beta-equilibrated matter in compact stars, and also for more refined comparisons with lattice studies at nonzero isospin chemical potential. |
0803.1940 | Christof Hendlmeier | Christof Hendlmeier, Andreas Schafer, Marco Stratmann | Next-to-leading order QCD corrections to spin-dependent hadron-pair
photoproduction | 9 pages, 2 eps figures | Eur.Phys.J.C55:597-605,2008 | 10.1140/epjc/s10052-008-0626-2 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We compute the next-to-leading order QCD corrections to the ``direct'' part
of the spin-dependent cross section for hadron-pair photoproduction. The
calculation is performed using largely analytical methods. We present a brief
phenomenological study of our results focussing on the $K$-factors and scale
dependence of the next-to-leading order cross sections. This process is
relevant for the extraction of the gluon polarization in present and future
spin-dependent lepton-nucleon scattering experiments.
| [
{
"created": "Thu, 13 Mar 2008 10:29:50 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Hendlmeier",
"Christof",
""
],
[
"Schafer",
"Andreas",
""
],
[
"Stratmann",
"Marco",
""
]
] | We compute the next-to-leading order QCD corrections to the ``direct'' part of the spin-dependent cross section for hadron-pair photoproduction. The calculation is performed using largely analytical methods. We present a brief phenomenological study of our results focussing on the $K$-factors and scale dependence of the next-to-leading order cross sections. This process is relevant for the extraction of the gluon polarization in present and future spin-dependent lepton-nucleon scattering experiments. |
0902.0418 | Masato Arai | Masato Arai, Nobuchika Okada, Karel Smolek | Effects of unparticle on top spin correlation at the Large Hadron
Collider | 29 pages, 1 table, 12 figures, 2 figures added, typos in captions
corrected, version accepted for publication in PRD | Phys.Rev.D79:074019,2009 | 10.1103/PhysRevD.79.074019 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study effects of the scale invariant hidden sector, unparticle, proposed
by Georgi, on top spin correlation at the Large Hadron Collider. Assuming no
flavor changing interaction between the unparticles and the Standard Model
particles, there arises the top-antitop quark pair production process through
virtual unparticle exchanges in the s-channel in addition to the Standard Model
processes. In particular, we consider contributions of scalar and vector
unparticles and find that these make sizable deviations of the top spin
correlation from the Standard Model one.
| [
{
"created": "Tue, 3 Feb 2009 02:03:35 GMT",
"version": "v1"
},
{
"created": "Mon, 30 Mar 2009 04:38:15 GMT",
"version": "v2"
}
] | 2014-11-18 | [
[
"Arai",
"Masato",
""
],
[
"Okada",
"Nobuchika",
""
],
[
"Smolek",
"Karel",
""
]
] | We study effects of the scale invariant hidden sector, unparticle, proposed by Georgi, on top spin correlation at the Large Hadron Collider. Assuming no flavor changing interaction between the unparticles and the Standard Model particles, there arises the top-antitop quark pair production process through virtual unparticle exchanges in the s-channel in addition to the Standard Model processes. In particular, we consider contributions of scalar and vector unparticles and find that these make sizable deviations of the top spin correlation from the Standard Model one. |
2003.13645 | V. Sreekanth | Lakshmi J. Naik, V. Sreekanth, Manu Kurian and Vinod Chandra | Thermal dilepton production in collisional hot QCD medium in the
presence of chromo-turbulent fields | 13 pages, 8 figures | J.Phys.G 49 (2022) 7, 075103 | 10.1088/1361-6471/ac65a5 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The effects of collisional processes in the hot QCD medium to thermal
dilepton production from $q\overline{q}$ annihilation in relativistic heavy-ion
collisions have been investigated. The non-equilibrium corrections to the
momentum distribution function have been estimated within the framework of
ensemble-averaged diffusive Vlasov-Boltzmann equation, encoding the effects of
collisional processes and turbulent chromo-fields in the medium. The
contributions from the $2\rightarrow2$ elastic scattering processes have been
quantified for the thermal dilepton production rate. It is seen that the
collisional corrections enhance the equilibrium dilepton spectra at high $p_T$
and suppress at lower $p_T$. A comparative study between collisional and
anomalous contributions to the dilepton production rates has also been
explored. The collisional contributions are seen to be marginal over that due
to collisionless anomalous transport.
| [
{
"created": "Mon, 30 Mar 2020 17:27:58 GMT",
"version": "v1"
},
{
"created": "Thu, 1 Sep 2022 17:23:55 GMT",
"version": "v2"
}
] | 2022-09-02 | [
[
"Naik",
"Lakshmi J.",
""
],
[
"Sreekanth",
"V.",
""
],
[
"Kurian",
"Manu",
""
],
[
"Chandra",
"Vinod",
""
]
] | The effects of collisional processes in the hot QCD medium to thermal dilepton production from $q\overline{q}$ annihilation in relativistic heavy-ion collisions have been investigated. The non-equilibrium corrections to the momentum distribution function have been estimated within the framework of ensemble-averaged diffusive Vlasov-Boltzmann equation, encoding the effects of collisional processes and turbulent chromo-fields in the medium. The contributions from the $2\rightarrow2$ elastic scattering processes have been quantified for the thermal dilepton production rate. It is seen that the collisional corrections enhance the equilibrium dilepton spectra at high $p_T$ and suppress at lower $p_T$. A comparative study between collisional and anomalous contributions to the dilepton production rates has also been explored. The collisional contributions are seen to be marginal over that due to collisionless anomalous transport. |
hep-ph/0004055 | Hitoshi Yamamoto | C. S. Kim (Yonsei Univeristy), H. Yamamoto (The University of Hawaii) | Is Cabibbo-Kobayasi-Maskawa Matrix Unitary? | 8 pages, 1 figure | null | 10.1142/9789812791870_0012 | null | hep-ph | null | First, we give summary of the present values of CKM matrix elements. Then, we
discuss whether CKM matrix is unitary or not, and how we can find out if it is
not unitary.
| [
{
"created": "Thu, 6 Apr 2000 14:11:09 GMT",
"version": "v1"
}
] | 2016-11-23 | [
[
"Kim",
"C. S.",
"",
"Yonsei Univeristy"
],
[
"Yamamoto",
"H.",
"",
"The University of Hawaii"
]
] | First, we give summary of the present values of CKM matrix elements. Then, we discuss whether CKM matrix is unitary or not, and how we can find out if it is not unitary. |
1707.09967 | Daniel G. Figueroa | Daniel G. Figueroa, Mikhail Shaposhnikov | Anomalous non-conservation of fermion/chiral number in Abelian gauge
theories at finite temperature | Version matching publication, former Section V on 'Dynamics of chiral
charge' removed, and erratum appended at the end in light of the results
obtained in 1904.11892 [hep-th] | null | 10.1007/JHEP04(2018)026 | CERN-TH-2017-172 | hep-ph astro-ph.CO hep-lat hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss the non-conservation of fermion number (or chirality breaking,
depending on the fermionic charge assignment) in Abelian gauge theories at
finite temperature. We study different mechanisms of fermionic charge
disappearance in the high temperature plasma, using both analytical estimates
and real-time classical lattice numerical simulations. We investigate the
random walk of the Chern-Simons number $Q \propto \int d^4x F_{\mu\nu}{\tilde
F}^{\mu\nu}$, and show that it has a diffusive behaviour in the presence of an
external magnetic field $B$. This indicates that the mechanism for fermionic
number non-conservation for $B \neq 0$, is due to fluctuations of the gauge
fields, similarly as in the case of non-Abelian gauge theories. We determine
numerically, with lattice simulations, the rate $\Gamma$ of chirality
non-conservation associated with this diffusion. We find the rate to be a
factor $\mathcal{O}(10)$ larger compared to previous theoretical estimates,
what calls for a revision of the implications of Abelian fermion number and
chirality non-conservation for baryogenesis, magnetogenesis and chiral symmetry
evolution. An erratum can be found at the end of the manuscript, following the
results obtained in JHEP 10 (2019) 142 (1904.11892 [hep-th]), which reduce our
original claim in the discrepancy between theory and numerics by a factor $\sim
5-6$.
| [
{
"created": "Mon, 31 Jul 2017 17:20:29 GMT",
"version": "v1"
},
{
"created": "Mon, 17 Aug 2020 09:09:09 GMT",
"version": "v2"
}
] | 2020-08-18 | [
[
"Figueroa",
"Daniel G.",
""
],
[
"Shaposhnikov",
"Mikhail",
""
]
] | We discuss the non-conservation of fermion number (or chirality breaking, depending on the fermionic charge assignment) in Abelian gauge theories at finite temperature. We study different mechanisms of fermionic charge disappearance in the high temperature plasma, using both analytical estimates and real-time classical lattice numerical simulations. We investigate the random walk of the Chern-Simons number $Q \propto \int d^4x F_{\mu\nu}{\tilde F}^{\mu\nu}$, and show that it has a diffusive behaviour in the presence of an external magnetic field $B$. This indicates that the mechanism for fermionic number non-conservation for $B \neq 0$, is due to fluctuations of the gauge fields, similarly as in the case of non-Abelian gauge theories. We determine numerically, with lattice simulations, the rate $\Gamma$ of chirality non-conservation associated with this diffusion. We find the rate to be a factor $\mathcal{O}(10)$ larger compared to previous theoretical estimates, what calls for a revision of the implications of Abelian fermion number and chirality non-conservation for baryogenesis, magnetogenesis and chiral symmetry evolution. An erratum can be found at the end of the manuscript, following the results obtained in JHEP 10 (2019) 142 (1904.11892 [hep-th]), which reduce our original claim in the discrepancy between theory and numerics by a factor $\sim 5-6$. |
1101.4277 | Massimo Mannarelli | Roberto Anglani, Massimo Mannarelli and Marco Ruggieri | Collective modes in the color flavor locked phase | 21 pages, 10 figures, minor corrections, references added, almost
matches published version | New J. Phys.13:055002, 2011 | 10.1088/1367-2630/13/5/055002 | null | hep-ph astro-ph.HE cond-mat.supr-con | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the low energy effective action for the collective modes of the
color flavor locked phase of QCD. This phase of matter has long been known to
be a superfluid because by picking a phase its order parameter breaks the
quark-number $U(1)_B$ symmetry spontaneously. We consider the modes describing
fluctuations in the magnitude of the condensate, namely the Higgs mode, and in
the phase of the condensate, namely the Nambu-Goldstone (or
Anderson-Bogoliubov) mode associated with the breaking of $U(1)_B$. By
employing as microscopic theory the Nambu-Jona Lasinio model, we reproduce
known results for the Lagrangian of the Nambu-Goldstone field to the leading
order in the chemical potential and extend such results evaluating corrections
due to the gap parameter. Moreover, we determine the interaction terms between
the Higgs and the Nambu-Goldstone field. This study paves the way for a more
reliable study of various dissipative processes in rotating compact stars with
a quark matter core in the color flavor locked phase.
| [
{
"created": "Sat, 22 Jan 2011 10:52:01 GMT",
"version": "v1"
},
{
"created": "Wed, 18 May 2011 07:07:40 GMT",
"version": "v2"
}
] | 2015-03-17 | [
[
"Anglani",
"Roberto",
""
],
[
"Mannarelli",
"Massimo",
""
],
[
"Ruggieri",
"Marco",
""
]
] | We study the low energy effective action for the collective modes of the color flavor locked phase of QCD. This phase of matter has long been known to be a superfluid because by picking a phase its order parameter breaks the quark-number $U(1)_B$ symmetry spontaneously. We consider the modes describing fluctuations in the magnitude of the condensate, namely the Higgs mode, and in the phase of the condensate, namely the Nambu-Goldstone (or Anderson-Bogoliubov) mode associated with the breaking of $U(1)_B$. By employing as microscopic theory the Nambu-Jona Lasinio model, we reproduce known results for the Lagrangian of the Nambu-Goldstone field to the leading order in the chemical potential and extend such results evaluating corrections due to the gap parameter. Moreover, we determine the interaction terms between the Higgs and the Nambu-Goldstone field. This study paves the way for a more reliable study of various dissipative processes in rotating compact stars with a quark matter core in the color flavor locked phase. |
hep-ph/9909415 | Masaki Yoshimura | Kiko Fukuura, Takahiro Miura, Eiichi Takasugi and Masaki Yoshimura | Large CP Violation, Large Mixings of Neutrinos and Democratic-type
Neutrino Mass Matrix | LaTeX, 22pages, corrected some terminologies, reference added | Phys.Rev. D61 (2000) 073002 | 10.1103/PhysRevD.61.073002 | OU-HET 326 | hep-ph | null | We propose a democratic-type neutrino mass matrix based on $Z_3$ symmetry.
This mass matrix predicts the CP violation phase, $\delta=\pi/2$, and the
mixing angle between the mass eigenstates $\nu_2$ and $\nu_3$, $\sin^2
\theta_{23}= \cos^2 \theta_{23}=1/2$ which is essential for the large
atmospheric neutrino mixing, between $\nu_\mu$ and $\nu_\tau$. In this model,
the large CP violation effect may be expected.
| [
{
"created": "Fri, 17 Sep 1999 09:46:20 GMT",
"version": "v1"
},
{
"created": "Mon, 20 Sep 1999 05:37:56 GMT",
"version": "v2"
},
{
"created": "Mon, 15 Nov 1999 05:24:46 GMT",
"version": "v3"
}
] | 2009-10-31 | [
[
"Fukuura",
"Kiko",
""
],
[
"Miura",
"Takahiro",
""
],
[
"Takasugi",
"Eiichi",
""
],
[
"Yoshimura",
"Masaki",
""
]
] | We propose a democratic-type neutrino mass matrix based on $Z_3$ symmetry. This mass matrix predicts the CP violation phase, $\delta=\pi/2$, and the mixing angle between the mass eigenstates $\nu_2$ and $\nu_3$, $\sin^2 \theta_{23}= \cos^2 \theta_{23}=1/2$ which is essential for the large atmospheric neutrino mixing, between $\nu_\mu$ and $\nu_\tau$. In this model, the large CP violation effect may be expected. |
1906.10912 | Enrique Ruiz Arriola | Enrique Ruiz Arriola, Jacobo Ruiz de Elvira | Coarse graining hadronic scattering | 11 pages, 6 figures. Proceedings of the 9th Chiral Dynamics
International Workshop, Durham, NC, USA, 17-21 September, 2018 | null | null | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We show that it makes sense to coarse grain hadronic interactions such as
$\pi\pi$ and $\pi N$ reactions following previous work on NN scattering.
Moreover, if the interaction is taken to be given by chiral dynamics at long
distances above a given value $r > r_c$ larger than the elementary radii of the
interaction hadrons the unknown short distance region $r< r_c$ is characterized
by a {\it finite} number of fitting parameters. This number of independent
parameters needed for a presumably complete description of scattering data for
a CM energy below $\sqrt{s}$ has been found to be given by $N_{\rm Par} = N_S
\times N_I \times (p r_c )^2 /2 $ with $N_S$ and $N_I$ the number of spin and
isospin channels, and $p$ the CM momentum respectively. Therefore, for an
experiment (or sets of experiments) with a total number of data $N_{\rm Dat}$
the number of degrees of freedom involved in a $\chi^2$-fit is given by $\nu =
N_{\rm Dat}-N_{\rm Par}$ and confidence levels can be obtained accordingly by
standard means. Namely a $1 \sigma$ confidence level corresponds to $\chi_{\rm
min}^2/\nu \in (1- \sqrt{2/\nu},1+\sqrt{2/\nu})$. We discuss the approach for
$\pi\pi$ and $\pi N$ with an eye put on a data selection program and the
eventual validation of chiral symmetry.
| [
{
"created": "Wed, 26 Jun 2019 08:46:37 GMT",
"version": "v1"
}
] | 2019-06-27 | [
[
"Arriola",
"Enrique Ruiz",
""
],
[
"de Elvira",
"Jacobo Ruiz",
""
]
] | We show that it makes sense to coarse grain hadronic interactions such as $\pi\pi$ and $\pi N$ reactions following previous work on NN scattering. Moreover, if the interaction is taken to be given by chiral dynamics at long distances above a given value $r > r_c$ larger than the elementary radii of the interaction hadrons the unknown short distance region $r< r_c$ is characterized by a {\it finite} number of fitting parameters. This number of independent parameters needed for a presumably complete description of scattering data for a CM energy below $\sqrt{s}$ has been found to be given by $N_{\rm Par} = N_S \times N_I \times (p r_c )^2 /2 $ with $N_S$ and $N_I$ the number of spin and isospin channels, and $p$ the CM momentum respectively. Therefore, for an experiment (or sets of experiments) with a total number of data $N_{\rm Dat}$ the number of degrees of freedom involved in a $\chi^2$-fit is given by $\nu = N_{\rm Dat}-N_{\rm Par}$ and confidence levels can be obtained accordingly by standard means. Namely a $1 \sigma$ confidence level corresponds to $\chi_{\rm min}^2/\nu \in (1- \sqrt{2/\nu},1+\sqrt{2/\nu})$. We discuss the approach for $\pi\pi$ and $\pi N$ with an eye put on a data selection program and the eventual validation of chiral symmetry. |
hep-ph/9805315 | Richard D. Ball | Richard D. Ball and Stefano Forte | Corrections at Small x | 5 pages which include 11 figures | null | null | Edinburgh 98/6, DFTT 22/98 | hep-ph | null | We show that the all order summation of small x logarithms cannot be included
in the Q^2 evolution of structure functions because the NLLx corrections
overwhelm the LLx contribution.
| [
{
"created": "Wed, 13 May 1998 18:47:23 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Ball",
"Richard D.",
""
],
[
"Forte",
"Stefano",
""
]
] | We show that the all order summation of small x logarithms cannot be included in the Q^2 evolution of structure functions because the NLLx corrections overwhelm the LLx contribution. |
hep-ph/9711472 | Toni Coarasa | J.A. Coarasa, David Garcia, Jaume Guasch, Ricardo A. Jimenez, Joan
Sola | Heavy charged Higgs boson decaying into top quark in the MSSM | 10 pages, LaTeX, 5 figs included as a separate file, full postscript
version available at ftp://ftp.ifae.es/preprint/ft/uabft433.ps | Phys.Lett.B425:329-336,1998 | 10.1016/S0370-2693(98)00255-X | UAB-FT-433 | hep-ph | null | Observing a heavy charged Higgs boson produced in the near future at the
Tevatron or at the LHC would be instant evidence of physics beyond the Standard
Model. Whether such a Higgs boson would be supersymmetric or not it could only
be decided after accurate prediction of its properties. Here we compute the
decay width of the dominant decay of such a boson, namely H^+ -> t \bar{b},
including the leading electroweak corrections originating from large Yukawa
couplings within the MSSM. These electroweak effects turn out to be of
comparable size to the O(alpha_s) QCD corrections in relevant portions of the
MSSM parameter space. Our analysis incorporates the stringent low-energy
constraints imposed by radiative B-meson decays.
| [
{
"created": "Tue, 25 Nov 1997 21:32:14 GMT",
"version": "v1"
}
] | 2010-01-28 | [
[
"Coarasa",
"J. A.",
""
],
[
"Garcia",
"David",
""
],
[
"Guasch",
"Jaume",
""
],
[
"Jimenez",
"Ricardo A.",
""
],
[
"Sola",
"Joan",
""
]
] | Observing a heavy charged Higgs boson produced in the near future at the Tevatron or at the LHC would be instant evidence of physics beyond the Standard Model. Whether such a Higgs boson would be supersymmetric or not it could only be decided after accurate prediction of its properties. Here we compute the decay width of the dominant decay of such a boson, namely H^+ -> t \bar{b}, including the leading electroweak corrections originating from large Yukawa couplings within the MSSM. These electroweak effects turn out to be of comparable size to the O(alpha_s) QCD corrections in relevant portions of the MSSM parameter space. Our analysis incorporates the stringent low-energy constraints imposed by radiative B-meson decays. |
2002.10894 | Bernd Kniehl | Bernd A. Kniehl, Oleg L. Veretin | Bilinear quark operators in the RI/SMOM scheme at three loops | 9 pages, 1 figure, minor changes, matches journal version | Phys. Lett. B 804 (2020) 135398 (5 pages) | 10.1016/j.physletb.2020.135398 | DESY 20-030 | hep-ph hep-lat | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider the renormalization of the matrix elements of the bilinear quark
operators $\bar{\psi}\psi$, $\bar{\psi}\gamma_\mu\psi$, and
$\bar{\psi}\sigma_{\mu\nu}\psi$ at next-to-next-to-next-to-leading order in QCD
perturbation theory at the symmetric subtraction point. This allows us to
obtain conversion factors between the $\overline{\rm MS}$ scheme and the
regularization invariant symmetric momentum subtraction (RI/SMOM) scheme. The
obtained results can be used to reduce the errors in determinations of quark
masses from lattice QCD simulations. The results are given in Landau gauge.
| [
{
"created": "Tue, 25 Feb 2020 14:34:55 GMT",
"version": "v1"
},
{
"created": "Mon, 30 Mar 2020 16:04:38 GMT",
"version": "v2"
}
] | 2020-03-31 | [
[
"Kniehl",
"Bernd A.",
""
],
[
"Veretin",
"Oleg L.",
""
]
] | We consider the renormalization of the matrix elements of the bilinear quark operators $\bar{\psi}\psi$, $\bar{\psi}\gamma_\mu\psi$, and $\bar{\psi}\sigma_{\mu\nu}\psi$ at next-to-next-to-next-to-leading order in QCD perturbation theory at the symmetric subtraction point. This allows us to obtain conversion factors between the $\overline{\rm MS}$ scheme and the regularization invariant symmetric momentum subtraction (RI/SMOM) scheme. The obtained results can be used to reduce the errors in determinations of quark masses from lattice QCD simulations. The results are given in Landau gauge. |
2201.02618 | Daniel Simons | Daniel Simons, Erik Gustafson, Yannick Meurice | Variations to the z-Expansion of the Form Factor Describing the Decay of
B Mesons | null | null | null | FERMILAB-CONF-21-734-T | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We examine the decay rate of the particle decay $B^0 \rightarrow D^- \ell^+
\nu_{\ell}$ using data collected from the Belle Collaboration. We studied three
parameterizations of the form factor which describe the differential decay
rate, the Caprini, Lellouch, and Neubert (CLN) parametrization, the Boyd,
Grinstein, and Lebed (BGL) parametrization, and the Bourrely, Caprini, and
Lellouch (BCL) parameterization. The form factor is a function of the hadronic
recoil variable $w$, and each parameterization contains unique free parameters
which are the focus of this work. We test the extrapolations of the form factor
by fitting many different subsets of the low $w$ data and then compare the
prediction of the fit to the high $w$ data using a $\chi^2$-metric. By only
fitting the low $w$ data we are able to examine the stability of extrapolations
which will be informative for lattice simulations.
| [
{
"created": "Fri, 7 Jan 2022 00:07:53 GMT",
"version": "v1"
}
] | 2022-01-11 | [
[
"Simons",
"Daniel",
""
],
[
"Gustafson",
"Erik",
""
],
[
"Meurice",
"Yannick",
""
]
] | We examine the decay rate of the particle decay $B^0 \rightarrow D^- \ell^+ \nu_{\ell}$ using data collected from the Belle Collaboration. We studied three parameterizations of the form factor which describe the differential decay rate, the Caprini, Lellouch, and Neubert (CLN) parametrization, the Boyd, Grinstein, and Lebed (BGL) parametrization, and the Bourrely, Caprini, and Lellouch (BCL) parameterization. The form factor is a function of the hadronic recoil variable $w$, and each parameterization contains unique free parameters which are the focus of this work. We test the extrapolations of the form factor by fitting many different subsets of the low $w$ data and then compare the prediction of the fit to the high $w$ data using a $\chi^2$-metric. By only fitting the low $w$ data we are able to examine the stability of extrapolations which will be informative for lattice simulations. |
0807.2986 | Zhe Xu | Zhe Xu, Carsten Greiner and Horst Stoecker | QCD plasma thermalization, collective flow and extraction of shear
viscosity | 8 pages, 5 figures, Plenary talk at 20th International Conference on
Ultra-Relativistic Nucleus Nucleus Collisions (Quark Matter 2008), Jaipur,
India, 4-10 Feb. 2008 | J.Phys.G35:104016,2008 | 10.1088/0954-3899/35/10/104016 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Fast thermalization and elliptic flow of QCD matter found at the Relativistic
Heavy Ion Collider (RHIC) are understood as the consequence of perturbative QCD
(pQCD) interactions within a (3+1) dimensional parton cascade. The main
contributions stem from pQCD-inspired bremsstrahlung. We extract the shear
viscosity to entropy ratio, which is between 0.08 and 0.15.
| [
{
"created": "Fri, 18 Jul 2008 14:54:45 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Xu",
"Zhe",
""
],
[
"Greiner",
"Carsten",
""
],
[
"Stoecker",
"Horst",
""
]
] | Fast thermalization and elliptic flow of QCD matter found at the Relativistic Heavy Ion Collider (RHIC) are understood as the consequence of perturbative QCD (pQCD) interactions within a (3+1) dimensional parton cascade. The main contributions stem from pQCD-inspired bremsstrahlung. We extract the shear viscosity to entropy ratio, which is between 0.08 and 0.15. |
2005.05488 | Roman Zhokhov | T. G. Khunjua, K. G. Klimenko, R. N. Zhokhov | Electrical neutrality and $\beta$-equilibrium conditions in dense quark
matter: generation of charged pion condensation by chiral imbalance | 16 pages, 14 figures | null | 10.1140/epjc/s10052-020-08502-w | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The phase diagram of dense quark matter with chiral imbalance is considered
with the conditions of electric neutrality and $\beta$-equilibrium. It has been
shown recently that chiral imbalance can generate charged pion condensation in
dense quark matter, so it was interesting to verify that this phenomenon takes
place in realistic physical scenarios such as electrically neutral matter in
$\beta$-equilibrium, because a window of pion condensation at dense quark
matter phase diagram (without chiral imbalance) predicted earlier was closed by
the consideration of these conditions at the physical current quark mass. In
this paper it has been shown that the charged pion condensation is generated by
chiral imbalance in the dense electric neutral quark/baryonic matter in
$\beta$-equilibrium, i. e. matter in neutron stars. It has been also
demonstrated that pion condensation is inevitable phenomenon in dense quark
matter with chiral imbalance if there is non-zero chiral imbalance in two
forms, chiral and chiral isospin one. It seems that in this case pion
condensation phase can be hardly avoided by any physical constraint on isopin
imbalance and that this conclusion can be probably generalized from neutron
star matter to the matter produced in heavy ion collisions or in neutron star
mergers. The chiral limit and the physical piont (physical pion mass) has been
considered and it was shown that the appearance of pion condensation is not
much affected by the consideration of non-zero current quark mass.
| [
{
"created": "Mon, 11 May 2020 23:45:18 GMT",
"version": "v1"
}
] | 2020-12-02 | [
[
"Khunjua",
"T. G.",
""
],
[
"Klimenko",
"K. G.",
""
],
[
"Zhokhov",
"R. N.",
""
]
] | The phase diagram of dense quark matter with chiral imbalance is considered with the conditions of electric neutrality and $\beta$-equilibrium. It has been shown recently that chiral imbalance can generate charged pion condensation in dense quark matter, so it was interesting to verify that this phenomenon takes place in realistic physical scenarios such as electrically neutral matter in $\beta$-equilibrium, because a window of pion condensation at dense quark matter phase diagram (without chiral imbalance) predicted earlier was closed by the consideration of these conditions at the physical current quark mass. In this paper it has been shown that the charged pion condensation is generated by chiral imbalance in the dense electric neutral quark/baryonic matter in $\beta$-equilibrium, i. e. matter in neutron stars. It has been also demonstrated that pion condensation is inevitable phenomenon in dense quark matter with chiral imbalance if there is non-zero chiral imbalance in two forms, chiral and chiral isospin one. It seems that in this case pion condensation phase can be hardly avoided by any physical constraint on isopin imbalance and that this conclusion can be probably generalized from neutron star matter to the matter produced in heavy ion collisions or in neutron star mergers. The chiral limit and the physical piont (physical pion mass) has been considered and it was shown that the appearance of pion condensation is not much affected by the consideration of non-zero current quark mass. |
hep-ph/9308253 | Alexander Bochkarev | A. Bochkarev | On the relation between Euclidean and real time calculations of Green
functions at finite temperature | 10 pages, 2 figs not included, Phys.Rev.D (in press), PITT-93-07 | Phys.Rev.D48:2382-2384,1993 | 10.1103/PhysRevD.48.R2382 | null | hep-ph | null | We find a relation between the semiclassical approximation of the temperature
(Matsubara) 2-point correlator and the corresponding classical Green function
in real time at finite temperature. The anharmonic oscillator at finite
temperature is used to illustrate our statement, which is however of rather
general origin.
| [
{
"created": "Tue, 10 Aug 1993 19:10:53 GMT",
"version": "v1"
}
] | 2009-12-30 | [
[
"Bochkarev",
"A.",
""
]
] | We find a relation between the semiclassical approximation of the temperature (Matsubara) 2-point correlator and the corresponding classical Green function in real time at finite temperature. The anharmonic oscillator at finite temperature is used to illustrate our statement, which is however of rather general origin. |
1706.05521 | Seung-il Nam | Seung-il Nam | Photo- and electroproduction of $\Lambda(1405)$ via $\gamma^{(*)}p\to
K^+\pi^+\Sigma^-$ | 11 pages, 10 figures, accepted for publication via PRD | null | 10.1103/PhysRevD.96.076021 | PKNU-NuHaTh-2017-03 | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this work, we perform a \textit{toy-model} analysis for the unpolarized
photo- and electroproduction of $\Lambda(1405)\equiv\Lambda^*$ via
$\gamma^{(*)}p\to K^+\pi^+\Sigma^-$ by employing the effective Lagrangian
approach at the tree level only. We consider that $\Lambda^*$ consists of the
high-mass ($H$) and low-mass ($L$) poles as suggested by the chiral unitary
model (ChUM). We determine all the model parameters including coupling
constants and cutoff parameters for the phenomenological strong form factors by
using the theoretical information from ChUM and available experimental data.
The electromagnetic (EM) form factors for the two poles are parameterized
appropriately being similar to that for the neutron by employing the ChUM
estimates for the EM root-mean-squared (rms) radii for the two poles. We
observe from the numerical calculations that, for the photoproduction of
$\Lambda^*$, the interference between the two poles turns out to be
destructive, resulting in the single-peak line at
$M_{\pi^+\Sigma^-}\approx1405$ MeV in the invariant-mass distribution. On the
contrary, there appear two peaks in the distribution for the electroproduction
as observed in the CLAS/Jlab electroproduction data, due to the constructive
interference, which is mainly caused by the Dirac form factors for the two
poles. From this observation, we conclude that, in order to explain the photo-
and electroproduction data simultaneously, i.e., \textit{single} and
\textit{double} peaks, respectively, in the invariant-mass distribution, the
interference patterns for the two poles should follow those suggested by ChUM.
In turn, it is a strong theoretical and experimental supports for the two-pole
structure scenario for $\Lambda^*$.
| [
{
"created": "Sat, 17 Jun 2017 12:11:31 GMT",
"version": "v1"
},
{
"created": "Wed, 11 Oct 2017 17:45:25 GMT",
"version": "v2"
}
] | 2017-11-22 | [
[
"Nam",
"Seung-il",
""
]
] | In this work, we perform a \textit{toy-model} analysis for the unpolarized photo- and electroproduction of $\Lambda(1405)\equiv\Lambda^*$ via $\gamma^{(*)}p\to K^+\pi^+\Sigma^-$ by employing the effective Lagrangian approach at the tree level only. We consider that $\Lambda^*$ consists of the high-mass ($H$) and low-mass ($L$) poles as suggested by the chiral unitary model (ChUM). We determine all the model parameters including coupling constants and cutoff parameters for the phenomenological strong form factors by using the theoretical information from ChUM and available experimental data. The electromagnetic (EM) form factors for the two poles are parameterized appropriately being similar to that for the neutron by employing the ChUM estimates for the EM root-mean-squared (rms) radii for the two poles. We observe from the numerical calculations that, for the photoproduction of $\Lambda^*$, the interference between the two poles turns out to be destructive, resulting in the single-peak line at $M_{\pi^+\Sigma^-}\approx1405$ MeV in the invariant-mass distribution. On the contrary, there appear two peaks in the distribution for the electroproduction as observed in the CLAS/Jlab electroproduction data, due to the constructive interference, which is mainly caused by the Dirac form factors for the two poles. From this observation, we conclude that, in order to explain the photo- and electroproduction data simultaneously, i.e., \textit{single} and \textit{double} peaks, respectively, in the invariant-mass distribution, the interference patterns for the two poles should follow those suggested by ChUM. In turn, it is a strong theoretical and experimental supports for the two-pole structure scenario for $\Lambda^*$. |
0908.0139 | Alexey Popov | Alexey V. Popov | Symplectic approach to lightcone QCD | 24 pages, new title; final version | Nucl. Phys. A836:136-158, 2010 | 10.1016/j.nuclphysa.2010.01.163 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We develop a symplectic method of quantization of lightcone QCD. We find that
boundary gauge fields are crucial for a consistent and complete quantization.
By applying the symplectic Faddeev-Jackiw method, we very carefully remove
unphysical degrees of freedom and obtain the true phase space and the complete
Hamiltonian. The result is important for the high energy QCD evolution and for
a further extension of the JIMWLK equation, for which we find the second-order
correction. Finally, we make an important note about a peculiarity of four
space-time dimensions. In additional, our method sheds new light on the
lightcone quantization of a scalar field.
| [
{
"created": "Sun, 2 Aug 2009 17:21:17 GMT",
"version": "v1"
},
{
"created": "Tue, 3 Nov 2009 08:54:33 GMT",
"version": "v2"
},
{
"created": "Sat, 20 Mar 2010 15:05:17 GMT",
"version": "v3"
}
] | 2010-04-14 | [
[
"Popov",
"Alexey V.",
""
]
] | We develop a symplectic method of quantization of lightcone QCD. We find that boundary gauge fields are crucial for a consistent and complete quantization. By applying the symplectic Faddeev-Jackiw method, we very carefully remove unphysical degrees of freedom and obtain the true phase space and the complete Hamiltonian. The result is important for the high energy QCD evolution and for a further extension of the JIMWLK equation, for which we find the second-order correction. Finally, we make an important note about a peculiarity of four space-time dimensions. In additional, our method sheds new light on the lightcone quantization of a scalar field. |
hep-ph/0610145 | Xavier Garcia i Tormo | Xavier Garcia i Tormo | Applications of effective field theories to the strong interactions of
heavy quarks | 109 pages, 38 figures. Ph.D. thesis, includes a summary in Catalan | null | null | null | hep-ph | null | We apply effective field theory techniques to study several heavy quark
systems. The topics analysed include the singlet static QCD potential,
anomalous dimensions in SCET and a comprehensive study of semi-inclusive
radiative heavy quarkonium decays.
| [
{
"created": "Wed, 11 Oct 2006 21:48:55 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Tormo",
"Xavier Garcia i",
""
]
] | We apply effective field theory techniques to study several heavy quark systems. The topics analysed include the singlet static QCD potential, anomalous dimensions in SCET and a comprehensive study of semi-inclusive radiative heavy quarkonium decays. |
1409.5244 | Krzysztof M. Graczyk | Krzysztof M. Graczyk and Cezary Juszczak | Applications of Neural Networks in Hadron Physics | 16 pages, 9 figures, Invited contribution to the Journal of Physics
G: Nuclear and Particle Physics focus section entitled "Enhancing the
interaction between nuclear experiment and theory through information and
statistics", in press | J.Phys. G: Nucl. Phys. 42 034019 (2015) | 10.1088/0954-3899/42/3/034019 | null | hep-ph nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The Bayesian approach for the feed-forward neural networks is reviewed. Its
potential for usage in hadron physics is discussed. As an example of the
application the study of the the two-photon exchange effect is presented. We
focus on the model comparison, the estimation of the systematic uncertainties
due to the choice of the model, and the over-fitting. As an illustration the
predictions of the cross sections ratio $d \sigma(e^+ p\to e^+ p)/d \sigma(e^-
p\to e^- p)$ are given together with the estimate of the uncertainty due to the
parametrization choice.
| [
{
"created": "Thu, 18 Sep 2014 10:16:53 GMT",
"version": "v1"
}
] | 2015-02-10 | [
[
"Graczyk",
"Krzysztof M.",
""
],
[
"Juszczak",
"Cezary",
""
]
] | The Bayesian approach for the feed-forward neural networks is reviewed. Its potential for usage in hadron physics is discussed. As an example of the application the study of the the two-photon exchange effect is presented. We focus on the model comparison, the estimation of the systematic uncertainties due to the choice of the model, and the over-fitting. As an illustration the predictions of the cross sections ratio $d \sigma(e^+ p\to e^+ p)/d \sigma(e^- p\to e^- p)$ are given together with the estimate of the uncertainty due to the parametrization choice. |
2006.13137 | Naoya Kitajima | Naoya Kitajima, Fuminobu Takahashi | Primordial Black Holes from QCD Axion Bubbles | 22 pages, 6 figures | null | 10.1088/1475-7516/2020/11/060 | TU-1103, IPMU20-0066 | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose a scenario in which a strong Peccei-Quinn (PQ) symmetry breaking
in the early universe results in large inhomogeneities of the initial QCD axion
field value, leading to the formation of very dense axion bubbles. Some of the
axion bubbles subsequently collapse into primordial black holes (PBHs). The
spatially homogeneous part of the QCD axion explains dark matter of the
universe, while the PBHs arising from the axion bubbles can explain the LIGO
events or the seed of supermassive black holes. Interestingly, the mass of PBH
is determined by the axion decay constant; for $f_a = 10^{17} (10^{16})$ GeV,
the PBH mass is heavier than about $10 (10^4) M_\odot$. In addition, axion
miniclusters are also formed from the axion bubbles more abundantly than PBHs,
and their masses are expected to be heavier than in the usual scenario based on
the spontaneous breaking of the PQ symmetry after inflation.
| [
{
"created": "Tue, 23 Jun 2020 16:32:34 GMT",
"version": "v1"
}
] | 2020-12-09 | [
[
"Kitajima",
"Naoya",
""
],
[
"Takahashi",
"Fuminobu",
""
]
] | We propose a scenario in which a strong Peccei-Quinn (PQ) symmetry breaking in the early universe results in large inhomogeneities of the initial QCD axion field value, leading to the formation of very dense axion bubbles. Some of the axion bubbles subsequently collapse into primordial black holes (PBHs). The spatially homogeneous part of the QCD axion explains dark matter of the universe, while the PBHs arising from the axion bubbles can explain the LIGO events or the seed of supermassive black holes. Interestingly, the mass of PBH is determined by the axion decay constant; for $f_a = 10^{17} (10^{16})$ GeV, the PBH mass is heavier than about $10 (10^4) M_\odot$. In addition, axion miniclusters are also formed from the axion bubbles more abundantly than PBHs, and their masses are expected to be heavier than in the usual scenario based on the spontaneous breaking of the PQ symmetry after inflation. |
1606.00378 | Arnab Dasgupta | Debasish Borah and Arnab Dasgupta | Charged Lepton Flavour Violation and Neutrinoless Double Beta Decay in
Left-Right Symmetric Models with Type I+II Seesaw | 23 pages and 21 figures. minor revision, to appear in JHEP. arXiv
admin note: text overlap with arXiv:1509.01800 | null | 10.1007/JHEP07(2016)022 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the new physics contributions to neutrinoless double beta decay
($0\nu\beta \beta$) half-life and lepton flavour violation (LFV) amplitude
within the framework of the minimal left-right symmetric model (MLRSM).
Considering all possible new physics contributions to $0\nu\beta \beta$ and
charged lepton flavour violation $\mu \rightarrow e \gamma, \mu \rightarrow 3e$
in MLRSM, we constrain the parameter space of the model from the requirement of
satisfying existing experimental bounds. Assuming the breaking scale of the
left-right symmetry to be $\mathcal{O}(1)$ TeV accessible at ongoing and near
future collider experiments, we consider the most general type I+II seesaw
mechanism for the origin of tiny neutrino masses. Choosing the relative
contribution of the type II seesaw term allows us to calculate the right handed
neutrino mass matrix as well as Dirac neutrino mass matrix as a function of the
model parameters, required for the calculation of $0\nu\beta \beta$ and LFV
amplitudes. We show that such a general type I+II seesaw structure results in
more allowed parameter space compared to individual type I or type II seesaw
cases considered in earlier works. In particular, we show that the doubly
charged scalar masses $M_{\Delta}$ are allowed to be smaller than the heaviest
right handed neutrino mass $M_N$ from the present experimental bounds in these
scenarios which is in contrast to earlier results with individual type I or
type II seesaw showing $M_{\Delta} > M_N$.
| [
{
"created": "Wed, 1 Jun 2016 18:07:58 GMT",
"version": "v1"
},
{
"created": "Mon, 20 Jun 2016 11:23:24 GMT",
"version": "v2"
}
] | 2016-08-03 | [
[
"Borah",
"Debasish",
""
],
[
"Dasgupta",
"Arnab",
""
]
] | We study the new physics contributions to neutrinoless double beta decay ($0\nu\beta \beta$) half-life and lepton flavour violation (LFV) amplitude within the framework of the minimal left-right symmetric model (MLRSM). Considering all possible new physics contributions to $0\nu\beta \beta$ and charged lepton flavour violation $\mu \rightarrow e \gamma, \mu \rightarrow 3e$ in MLRSM, we constrain the parameter space of the model from the requirement of satisfying existing experimental bounds. Assuming the breaking scale of the left-right symmetry to be $\mathcal{O}(1)$ TeV accessible at ongoing and near future collider experiments, we consider the most general type I+II seesaw mechanism for the origin of tiny neutrino masses. Choosing the relative contribution of the type II seesaw term allows us to calculate the right handed neutrino mass matrix as well as Dirac neutrino mass matrix as a function of the model parameters, required for the calculation of $0\nu\beta \beta$ and LFV amplitudes. We show that such a general type I+II seesaw structure results in more allowed parameter space compared to individual type I or type II seesaw cases considered in earlier works. In particular, we show that the doubly charged scalar masses $M_{\Delta}$ are allowed to be smaller than the heaviest right handed neutrino mass $M_N$ from the present experimental bounds in these scenarios which is in contrast to earlier results with individual type I or type II seesaw showing $M_{\Delta} > M_N$. |
1103.5061 | Gregory Peim | Sujeet Akula, Daniel Feldman, Zuowei Liu, Pran Nath, and Gregory Peim | New Constraints on Dark Matter from CMS and ATLAS Data | 18 pages, 5 figures, text expanded and updated | Mod.Phys.Lett.A26:1521-1535,2011 | 10.1142/S0217732311036292 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Constraints on dark matter from the first CMS and ATLAS SUSY searches are
investigated. It is shown that within the minimal supergravity model, the early
search for supersymmetry at the LHC has depleted a large portion of the
signature space in dark matter direct detection experiments. In particular, the
prospects for detecting signals of dark matter in the XENON and CDMS
experiments are significantly affected in the low neutralino mass region. Here
the relic density of dark matter typically arises from slepton coannihilations
in the early universe. In contrast, it is found that the CMS and ATLAS analyses
leave untouched the Higgs pole and the Hyperbolic Branch/Focus Point regions,
which are now being probed by the most recent XENON results. Analysis is also
done for supergravity models with non-universal soft breaking where one finds
that a part of the dark matter signature space depleted by the CMS and ATLAS
cuts in the minimal SUGRA case is repopulated. Thus, observation of dark matter
in the LHC depleted region of minimal supergravity may indicate
non-universalities in soft breaking.
| [
{
"created": "Fri, 25 Mar 2011 18:51:10 GMT",
"version": "v1"
},
{
"created": "Wed, 27 Apr 2011 20:40:30 GMT",
"version": "v2"
}
] | 2011-07-19 | [
[
"Akula",
"Sujeet",
""
],
[
"Feldman",
"Daniel",
""
],
[
"Liu",
"Zuowei",
""
],
[
"Nath",
"Pran",
""
],
[
"Peim",
"Gregory",
""
]
] | Constraints on dark matter from the first CMS and ATLAS SUSY searches are investigated. It is shown that within the minimal supergravity model, the early search for supersymmetry at the LHC has depleted a large portion of the signature space in dark matter direct detection experiments. In particular, the prospects for detecting signals of dark matter in the XENON and CDMS experiments are significantly affected in the low neutralino mass region. Here the relic density of dark matter typically arises from slepton coannihilations in the early universe. In contrast, it is found that the CMS and ATLAS analyses leave untouched the Higgs pole and the Hyperbolic Branch/Focus Point regions, which are now being probed by the most recent XENON results. Analysis is also done for supergravity models with non-universal soft breaking where one finds that a part of the dark matter signature space depleted by the CMS and ATLAS cuts in the minimal SUGRA case is repopulated. Thus, observation of dark matter in the LHC depleted region of minimal supergravity may indicate non-universalities in soft breaking. |
1802.05168 | Stefan Leupold | M{\aa}ns Holmberg and Stefan Leupold (Uppsala U.) | The relativistic chiral Lagrangian for decuplet and octet baryons at
next-to-leading order | 12 pages | null | 10.1140/epja/i2018-12533-3 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A complete and minimal relativistic Lagrangian is constructed at
next-to-leading order for SU(3) chiral perturbation theory in the presence of
baryon octet and baryon decuplet states. The Lagrangian has 13 terms for the
pure decuplet sector, 6 terms for the transition sector from baryon octet to
decuplet and (as already known from the literature) 16 terms for the pure octet
sector. The minimal field content of 25 of these terms is meson-baryon
four-point interactions. 3 terms give rise to the mass splitting for baryon
octet and decuplet states, respectively. 2 terms give rise to overall mass
shifts. 4 terms provide anomalous magnetic moments and a decuplet-to-octet
magnetic transition moment. 1 term leads to an axial vector transition moment.
It is shown that meson-baryon three-point coupling constants come in at leading
order whereas no additional one appears in the minimal Lagrangian at
next-to-leading order. Those low-energy constants that give rise to mass
splitting and magnetic moments, respectively, are determined. Predictions are
provided for radiative decays of decuplet to octet baryons.
| [
{
"created": "Wed, 14 Feb 2018 15:49:03 GMT",
"version": "v1"
}
] | 2018-08-01 | [
[
"Holmberg",
"Måns",
"",
"Uppsala U."
],
[
"Leupold",
"Stefan",
"",
"Uppsala U."
]
] | A complete and minimal relativistic Lagrangian is constructed at next-to-leading order for SU(3) chiral perturbation theory in the presence of baryon octet and baryon decuplet states. The Lagrangian has 13 terms for the pure decuplet sector, 6 terms for the transition sector from baryon octet to decuplet and (as already known from the literature) 16 terms for the pure octet sector. The minimal field content of 25 of these terms is meson-baryon four-point interactions. 3 terms give rise to the mass splitting for baryon octet and decuplet states, respectively. 2 terms give rise to overall mass shifts. 4 terms provide anomalous magnetic moments and a decuplet-to-octet magnetic transition moment. 1 term leads to an axial vector transition moment. It is shown that meson-baryon three-point coupling constants come in at leading order whereas no additional one appears in the minimal Lagrangian at next-to-leading order. Those low-energy constants that give rise to mass splitting and magnetic moments, respectively, are determined. Predictions are provided for radiative decays of decuplet to octet baryons. |
2211.12115 | Shrihari Gopalakrishna | Shrihari Gopalakrishna and Rakesh Tibrewala | Effective Theory for Baryogenesis with a Majorana Fermion Pair Coupled
to Quarks | 28 pages, 4 figures; v2: published version; added appendix on Fierz
rearrangement (with typos corrected); added BAU section with Boltzmann
equations; updated n-nbar oscillation section; other updates to improve
readability | null | 10.1103/PhysRevD.107.115029 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | With a goal toward explaining the observed baryon asymmetry of the Universe,
we extend the standard model (SM) by adding a vector-vector dimension-six
effective operator coupling a new Dirac fermion $\chi$, uncharged under the SM
gauge symmetries but charged under baryon number, to a quark-like up-type
fermion and two identical down-type fermions. We introduce baryon number
violation by adding Majorana masses to $\chi$, which splits the Dirac fermion
into two Majorana fermions with unequal masses. We speculate on the origin of
the effective operator, the Majorana mass, and the new physics sector
connection to the SM, by considering some ultraviolet completion examples. In
addition to the baryon number violation, we show that $C$ and $CP$ invariances
can be violated in the theory, and the interference between tree and loop
amplitudes with on-shell intermediate states can lead to a baryon asymmetry in
$\chi$ decay and scattering processes. We write down the Boltzmann equation for
baryon number in the early Universe incorporating the decay and scattering
baryon asymmetries. We provide numerical estimates for the baryon asymmetry
generated, and for the neutron-antineutron oscillation rate.
| [
{
"created": "Tue, 22 Nov 2022 09:31:11 GMT",
"version": "v1"
},
{
"created": "Mon, 21 Aug 2023 05:55:01 GMT",
"version": "v2"
}
] | 2023-08-22 | [
[
"Gopalakrishna",
"Shrihari",
""
],
[
"Tibrewala",
"Rakesh",
""
]
] | With a goal toward explaining the observed baryon asymmetry of the Universe, we extend the standard model (SM) by adding a vector-vector dimension-six effective operator coupling a new Dirac fermion $\chi$, uncharged under the SM gauge symmetries but charged under baryon number, to a quark-like up-type fermion and two identical down-type fermions. We introduce baryon number violation by adding Majorana masses to $\chi$, which splits the Dirac fermion into two Majorana fermions with unequal masses. We speculate on the origin of the effective operator, the Majorana mass, and the new physics sector connection to the SM, by considering some ultraviolet completion examples. In addition to the baryon number violation, we show that $C$ and $CP$ invariances can be violated in the theory, and the interference between tree and loop amplitudes with on-shell intermediate states can lead to a baryon asymmetry in $\chi$ decay and scattering processes. We write down the Boltzmann equation for baryon number in the early Universe incorporating the decay and scattering baryon asymmetries. We provide numerical estimates for the baryon asymmetry generated, and for the neutron-antineutron oscillation rate. |
hep-ph/9512420 | K. V. L. Sarma | K.V.L. Sarma (Tata Institute, Bombay) | Nobel Leptons | 12 pages + 2 figures (supplied on request), latex, to appear in
Current Science (Indian Academy of Sciences) | null | null | TIFR/TH/95-56, November 1995 | hep-ph | null | The 1995 Nobel Prize in Physics is shared equally by the American physicists
Frederick J. Reines and Martin L. Perl for their pioneering experimental
contributions to lepton physics. Following is a brief account of their
discoveries.
| [
{
"created": "Mon, 25 Dec 1995 19:09:33 GMT",
"version": "v1"
}
] | 2009-09-25 | [
[
"Sarma",
"K. V. L.",
"",
"Tata Institute, Bombay"
]
] | The 1995 Nobel Prize in Physics is shared equally by the American physicists Frederick J. Reines and Martin L. Perl for their pioneering experimental contributions to lepton physics. Following is a brief account of their discoveries. |
hep-ph/9706464 | Leonid Burakovsky | L. Burakovsky, T. Goldman and L.P. Horwitz | New quadratic baryon mass relations | 14 pages, LaTeX | Phys.Rev.D56:7124-7132,1997 | 10.1103/PhysRevD.56.7124 | LA-UR-97-2333 | hep-ph | null | By assuming the existence of (quasi)-linear baryon Regge trajectories, we
derive new quadratic Gell-Mann-Okubo type baryon mass relations. These
relations are used to predict the masses of the charmed baryons absent from the
Baryon Summary Table so far, in good agreement with the predictions of many
other approaches.
| [
{
"created": "Mon, 23 Jun 1997 17:09:16 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Burakovsky",
"L.",
""
],
[
"Goldman",
"T.",
""
],
[
"Horwitz",
"L. P.",
""
]
] | By assuming the existence of (quasi)-linear baryon Regge trajectories, we derive new quadratic Gell-Mann-Okubo type baryon mass relations. These relations are used to predict the masses of the charmed baryons absent from the Baryon Summary Table so far, in good agreement with the predictions of many other approaches. |
hep-ph/9512395 | Tomasz Skwarnicki | Tomasz Skwarnicki (Syracuse University) | Decays of b quark | 35 pages (LateX), 23 figures (uuencoded postscript) Experimental
review of b decays, Lepton-Photon Conference, Beijing, Aug. 95 | null | null | HEPSY-95-05 | hep-ph | null | Importance of studies of $b$ quark decays and experimental status of various
measurements are discussed.
| [
{
"created": "Thu, 21 Dec 1995 17:23:42 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Skwarnicki",
"Tomasz",
"",
"Syracuse University"
]
] | Importance of studies of $b$ quark decays and experimental status of various measurements are discussed. |
2305.03749 | Jae Hyeok Chang | Jae Hyeok Chang, Reza Ebadi, Xuheng Luo, Erwin H. Tanin | Spectral distortions of astrophysical blackbodies as axion probes | 14 pages, 8 figures | null | null | UMD-PP-022-05 | hep-ph astro-ph.CO astro-ph.HE astro-ph.SR | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Recent studies reveal that more than a dozen of white dwarfs displaying
near-perfect blackbody spectra in the optical range have been lurking in the
Sloan Digital Sky Survey catalog. We point out that, in a way analogous to the
Cosmic Microwave Background, these stars serve as excellent testbeds for new
physics. Specifically, we show how their observed lack of spectral distortions
translates into limits on the parameter space of axions with electromagnetic
coupling. The prospects for future improvements are also discussed.
| [
{
"created": "Fri, 5 May 2023 18:00:01 GMT",
"version": "v1"
}
] | 2023-05-09 | [
[
"Chang",
"Jae Hyeok",
""
],
[
"Ebadi",
"Reza",
""
],
[
"Luo",
"Xuheng",
""
],
[
"Tanin",
"Erwin H.",
""
]
] | Recent studies reveal that more than a dozen of white dwarfs displaying near-perfect blackbody spectra in the optical range have been lurking in the Sloan Digital Sky Survey catalog. We point out that, in a way analogous to the Cosmic Microwave Background, these stars serve as excellent testbeds for new physics. Specifically, we show how their observed lack of spectral distortions translates into limits on the parameter space of axions with electromagnetic coupling. The prospects for future improvements are also discussed. |
hep-ph/9407270 | null | Nguyen Ai Viet | Predictions of noncommutative space-time | 7 pages, report SU-4240-583 June 1994. Talk given at MRST-94 Meeting:
"What Next? Exploring the Future of High-Energy Physics" held at Mc Gill
University, Montreal, Quebec, Canada, May 11-13, 1994. Some corrections have
been made | null | null | null | hep-ph gr-qc hep-th | null | An unified structure of noncommutative space-time for both gravity and
particle physics is presented. This gives possibilities of testing the idea of
noncommutative space-time at the currently available energy scale. There are
several arguments indicating that noncommutative space-time is visible already
at the electroweak scale. This noncommutative space-time predicts the top quark
mass m_t \sim 172 GeV, the Higgs mass M_H \sim 241 GeV and the existence of a
vector meson and a scalar, which interact universally with the matter.
| [
{
"created": "Mon, 11 Jul 1994 18:39:36 GMT",
"version": "v1"
},
{
"created": "Sun, 24 Jul 1994 21:57:39 GMT",
"version": "v2"
}
] | 2008-02-03 | [
[
"Viet",
"Nguyen Ai",
""
]
] | An unified structure of noncommutative space-time for both gravity and particle physics is presented. This gives possibilities of testing the idea of noncommutative space-time at the currently available energy scale. There are several arguments indicating that noncommutative space-time is visible already at the electroweak scale. This noncommutative space-time predicts the top quark mass m_t \sim 172 GeV, the Higgs mass M_H \sim 241 GeV and the existence of a vector meson and a scalar, which interact universally with the matter. |
1411.2804 | Claudio Coriano | Claudio Coriano, Luigi Delle Rose, Matteo Maria Maglio, Mirko Serino | Electroweak Corrections to Photon Scattering, Polarization and Lensing
in a Gravitational Background and the Near Horizon Limit | 38 pages, 18 figures. Revised final version, accepted on JHEP | JHEP 01 (2015) 091 | 10.1007/JHEP01(2015)091 | null | hep-ph astro-ph.HE hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the semiclassical approach to the lensing of photons in a
spherically symmetric gravitational background, starting from Born level and
include in our analysis the radiative corrections obtained from the electroweak
theory for the graviton/photon/photon vertex. In this approach, the cross
section is related to the angular variation of the impact parameter ($b$),
which is then solved for $b$ as a function of the angle of deflection, and
measured in horizon units ($b_h\equiv b/(2 G M)$). Exact numerical solutions
for the angular deflection are presented. The numerical analysis shows that
perturbation theory in a weak background agrees with the classical Einstein
formula for the deflection already at distances of the order of $20$ horizon
units ($\sim 20\, b_h$) and it is optimal in the description both of very
strong and weak lensings. We show that the electroweak corrections to the cross
section are sizeable, becoming very significant for high energy gamma rays. Our
analysis covers in energy most of the photon spectrum, from the cosmic
microwave background up to very high energy gamma rays, and scatterings with
any value of the photon impact parameter. We also study the helicity-flip
photon amplitude, which is of $O(\alpha^2)$ in the weak coupling $\alpha$, and
its massless fermion limit, which involves the exchange of a conformal anomaly
pole. The corresponding cross section is proportional to the Born level result
and brings to a simple renormalization of Einsten's formula.
| [
{
"created": "Tue, 11 Nov 2014 13:40:55 GMT",
"version": "v1"
},
{
"created": "Fri, 16 Jan 2015 02:47:16 GMT",
"version": "v2"
}
] | 2021-07-29 | [
[
"Coriano",
"Claudio",
""
],
[
"Rose",
"Luigi Delle",
""
],
[
"Maglio",
"Matteo Maria",
""
],
[
"Serino",
"Mirko",
""
]
] | We investigate the semiclassical approach to the lensing of photons in a spherically symmetric gravitational background, starting from Born level and include in our analysis the radiative corrections obtained from the electroweak theory for the graviton/photon/photon vertex. In this approach, the cross section is related to the angular variation of the impact parameter ($b$), which is then solved for $b$ as a function of the angle of deflection, and measured in horizon units ($b_h\equiv b/(2 G M)$). Exact numerical solutions for the angular deflection are presented. The numerical analysis shows that perturbation theory in a weak background agrees with the classical Einstein formula for the deflection already at distances of the order of $20$ horizon units ($\sim 20\, b_h$) and it is optimal in the description both of very strong and weak lensings. We show that the electroweak corrections to the cross section are sizeable, becoming very significant for high energy gamma rays. Our analysis covers in energy most of the photon spectrum, from the cosmic microwave background up to very high energy gamma rays, and scatterings with any value of the photon impact parameter. We also study the helicity-flip photon amplitude, which is of $O(\alpha^2)$ in the weak coupling $\alpha$, and its massless fermion limit, which involves the exchange of a conformal anomaly pole. The corresponding cross section is proportional to the Born level result and brings to a simple renormalization of Einsten's formula. |
hep-ph/0301240 | Ira Z. Rothstein | Ira Z. Rothstein (Carnegie Mellon Univ.) | Factorization, Power Corrections, and the Pion Form Factor | Published, extended, version | Phys.Rev. D70 (2004) 054024 | 10.1103/PhysRevD.70.054024 | null | hep-ph | null | This letter is an investigation of the pion form factor utilizing recently
developed effective field theory techniques. The primary results reported are:
Both the transition and electromagnetic form factors are corrected at order
$\Lambda/Q$. However, these corrections only arise due to time ordered products
which are sensitive to soft components of the pion. The usual higher twist wave
function corrections contribute only at order $\Lambda^2/Q^2$, when the quark
mass vanishes. In the case of the electromagnetic form factor the $\Lambda/Q$
power correction is enhanced by a power of $1/\alpha_s(Q)$ relative to the
leading order result of Brodsky and Lepage, if the scale $\sqrt{\Lambda Q}$ is
non-perturbative. This enhanced correction could explain the discrepancy with
the data.
| [
{
"created": "Mon, 27 Jan 2003 21:27:01 GMT",
"version": "v1"
},
{
"created": "Thu, 20 Feb 2003 19:56:59 GMT",
"version": "v2"
},
{
"created": "Thu, 5 Aug 2004 20:36:38 GMT",
"version": "v3"
}
] | 2009-11-10 | [
[
"Rothstein",
"Ira Z.",
"",
"Carnegie Mellon Univ."
]
] | This letter is an investigation of the pion form factor utilizing recently developed effective field theory techniques. The primary results reported are: Both the transition and electromagnetic form factors are corrected at order $\Lambda/Q$. However, these corrections only arise due to time ordered products which are sensitive to soft components of the pion. The usual higher twist wave function corrections contribute only at order $\Lambda^2/Q^2$, when the quark mass vanishes. In the case of the electromagnetic form factor the $\Lambda/Q$ power correction is enhanced by a power of $1/\alpha_s(Q)$ relative to the leading order result of Brodsky and Lepage, if the scale $\sqrt{\Lambda Q}$ is non-perturbative. This enhanced correction could explain the discrepancy with the data. |
hep-ph/9309230 | Pene | A.Le Yaouanc and O.P\`ene | Semileptonic Decays and CKM Matrix Elements in a TCF | 17 pages, LPTHE Orsay-93/33 | null | null | null | hep-ph | null | We argue that a Tau-Charm factory (TCF) could improve our knowledge of CKM
matrix elements since it is an incomparable tool to check the models and
methods applied to extract $V_{bu}$ from $B$ decay partial widths.
We report on some recent proposals to improve on parton model. Turning to
exclusive decays, we compare the predictions from quark models, QCD sum rules,
effective Lagrangians and lattice QCD. Quark models have anticipated on heavy
quark symmetry. Their difficutly to account for the $q^2$ dependence might be
partly cured by relativistic corrections. QCD sum rules and lattice seem to
disagree on the $q^2$ dependence of axial form factors. We discuss the
extrapolation from $D$ to $B$. Present uncertainties do not allow to predict
reliably the $B\ra\pi,\rho l \nu$ matrix elements. We argue that QCD sum rules
are in a good position to study $q^2$ dependence down to $q^2=0$. Lattice QCD
is able to check the heavy quark scaling laws for the heavy to light
semileptonic decays. It seems to confirm the increase of $A_2/A_1$ from $D$ to
$B$ meson predicted by the scaling laws. Finally semileptonic decays in a TCF
would give incomparable informations on $K\pi$ phase shifts, and on $K^{**}$
resonances.
| [
{
"created": "Mon, 6 Sep 1993 16:47:50 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Yaouanc",
"A. Le",
""
],
[
"Pène",
"O.",
""
]
] | We argue that a Tau-Charm factory (TCF) could improve our knowledge of CKM matrix elements since it is an incomparable tool to check the models and methods applied to extract $V_{bu}$ from $B$ decay partial widths. We report on some recent proposals to improve on parton model. Turning to exclusive decays, we compare the predictions from quark models, QCD sum rules, effective Lagrangians and lattice QCD. Quark models have anticipated on heavy quark symmetry. Their difficutly to account for the $q^2$ dependence might be partly cured by relativistic corrections. QCD sum rules and lattice seem to disagree on the $q^2$ dependence of axial form factors. We discuss the extrapolation from $D$ to $B$. Present uncertainties do not allow to predict reliably the $B\ra\pi,\rho l \nu$ matrix elements. We argue that QCD sum rules are in a good position to study $q^2$ dependence down to $q^2=0$. Lattice QCD is able to check the heavy quark scaling laws for the heavy to light semileptonic decays. It seems to confirm the increase of $A_2/A_1$ from $D$ to $B$ meson predicted by the scaling laws. Finally semileptonic decays in a TCF would give incomparable informations on $K\pi$ phase shifts, and on $K^{**}$ resonances. |
hep-ph/0409341 | Luc Marleau | Jimmy Fortier and Luc Marleau | On the electromagnetic form factors of the proton from generalized
Skyrme models | 8 pages, 2 figures, revtex | null | 10.1103/PhysRevD.70.114021 | null | hep-ph | null | We compare the prediction of Skyrme-like effective Lagrangians with data for
electromagnetic form factors of proton and consider the possibility of fixing
the parameters of these higher-order Lagrangians. Our results indicate that one
or two-parameter models can lead to better agreement with the data but more
accurate determination of the effective Lagragian faces theoretical
uncertainties.
| [
{
"created": "Wed, 29 Sep 2004 15:00:56 GMT",
"version": "v1"
},
{
"created": "Thu, 30 Sep 2004 11:53:58 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Fortier",
"Jimmy",
""
],
[
"Marleau",
"Luc",
""
]
] | We compare the prediction of Skyrme-like effective Lagrangians with data for electromagnetic form factors of proton and consider the possibility of fixing the parameters of these higher-order Lagrangians. Our results indicate that one or two-parameter models can lead to better agreement with the data but more accurate determination of the effective Lagragian faces theoretical uncertainties. |
hep-ph/0602242 | Howard E. Haber | Howard E. Haber and Deva O'Neil | Basis-independent methods for the two-Higgs-doublet model II. The
significance of tan(beta) | 56 pages, 5 tables, with Eq. (65) corrected (erratum to appear in
Physical Review D) | Phys.Rev. D74 (2006) 015018 | 10.1103/PhysRevD.74.015018 | SCIPP-06/01 | hep-ph | null | In the most general two-Higgs-doublet model (2HDM), there is no distinction
between the two complex hypercharge-one SU(2) doublet scalar fields, Phi_a
(a=1,2). Thus, any two orthonormal linear combinations of these two fields can
serve as a basis for the Lagrangian. All physical observables of the model must
therefore be basis-independent. For example, tan(beta)=<Phi_2^0>/<Phi_1^0> is
basis-dependent and thus cannot be a physical parameter of the model. In this
paper, we provide a basis-independent treatment of the Higgs sector with
particular attention to the neutral Higgs boson mass-eigenstates, which
generically are not eigenstates of CP. We then demonstrate that all physical
Higgs couplings are indeed independent of tan(beta). In specialized versions of
the 2HDM, tan(beta) can be promoted to a physical parameter of the
Higgs-fermion interactions. In the most general 2HDM, the Higgs-fermion
couplings can be expressed in terms of a number of physical "tan(beta)--like"
parameters that are manifestly basis-independent. The minimal supersymmetric
extension of the Standard Model provides a simple framework for exhibiting such
effects.
| [
{
"created": "Tue, 28 Feb 2006 09:22:07 GMT",
"version": "v1"
},
{
"created": "Mon, 5 Jun 2006 09:29:36 GMT",
"version": "v2"
},
{
"created": "Mon, 5 Jun 2006 21:56:40 GMT",
"version": "v3"
},
{
"created": "Fri, 9 Jun 2006 07:00:09 GMT",
"version": "v4"
},
{
"created": "Wed, 19 Jul 2006 00:14:53 GMT",
"version": "v5"
},
{
"created": "Thu, 7 Sep 2006 01:52:19 GMT",
"version": "v6"
}
] | 2009-11-11 | [
[
"Haber",
"Howard E.",
""
],
[
"O'Neil",
"Deva",
""
]
] | In the most general two-Higgs-doublet model (2HDM), there is no distinction between the two complex hypercharge-one SU(2) doublet scalar fields, Phi_a (a=1,2). Thus, any two orthonormal linear combinations of these two fields can serve as a basis for the Lagrangian. All physical observables of the model must therefore be basis-independent. For example, tan(beta)=<Phi_2^0>/<Phi_1^0> is basis-dependent and thus cannot be a physical parameter of the model. In this paper, we provide a basis-independent treatment of the Higgs sector with particular attention to the neutral Higgs boson mass-eigenstates, which generically are not eigenstates of CP. We then demonstrate that all physical Higgs couplings are indeed independent of tan(beta). In specialized versions of the 2HDM, tan(beta) can be promoted to a physical parameter of the Higgs-fermion interactions. In the most general 2HDM, the Higgs-fermion couplings can be expressed in terms of a number of physical "tan(beta)--like" parameters that are manifestly basis-independent. The minimal supersymmetric extension of the Standard Model provides a simple framework for exhibiting such effects. |
hep-ph/9508264 | Harry Blundell | Harry G. Blundell and Stephen Godfrey (Ottawa-Carleton Institute for
Physics) | The $\xi(2220)$ Revistited | Revised version to be published in Phys. Rev. D. Minor changes. Latex
file uses revtex version 3 and epsfig, 3 postcript figures are attached. The
full postcript version with embedded figures is available at
ftp://ftp.physics.carleton.ca/pub/theory/godfrey/ocipc9511.ps.Z | Phys.Rev. D53 (1996) 3700-3711 | 10.1103/PhysRevD.53.3700 | OCIP/C 95-11 | hep-ph | null | We calculated the decay widths of the $1^3F_2$ and $1^3F_4$ $s\bar{s}$ mesons
and compared them to the measured properties of the $\xi(2220)$ (now known as
the $f_4(2220)$). Including previously neglected decay modes we found that the
width of the $^3F_2$ state $s\bar{s}$ meson is much larger than previously
believed making this explanation unlikely. On the other hand the predicted
width of the $^3F_4$ state, although broader than the observed width, is
consistent within the uncertainties of the model. This interpretation predicts
large partial widths to $K K^*(892)$ and $K^*(892) K^*(892)$ final states which
should be looked for. A second possibility that would account for the different
properties of the $\xi(2220)$ seen in different experiments is that two
hadronic states exist at this mass. The first would be a broader $^3F_4$
$s\bar{s}$ state which is seen in hadron beam experiments while the second
would be a narrow state with high glue content seen in the gluon rich $J/\psi$
radiative decay. Further experimental results are needed to sort this out.
| [
{
"created": "Tue, 8 Aug 1995 17:26:57 GMT",
"version": "v1"
},
{
"created": "Thu, 14 Mar 1996 22:27:29 GMT",
"version": "v2"
}
] | 2009-10-28 | [
[
"Blundell",
"Harry G.",
"",
"Ottawa-Carleton Institute for\n Physics"
],
[
"Godfrey",
"Stephen",
"",
"Ottawa-Carleton Institute for\n Physics"
]
] | We calculated the decay widths of the $1^3F_2$ and $1^3F_4$ $s\bar{s}$ mesons and compared them to the measured properties of the $\xi(2220)$ (now known as the $f_4(2220)$). Including previously neglected decay modes we found that the width of the $^3F_2$ state $s\bar{s}$ meson is much larger than previously believed making this explanation unlikely. On the other hand the predicted width of the $^3F_4$ state, although broader than the observed width, is consistent within the uncertainties of the model. This interpretation predicts large partial widths to $K K^*(892)$ and $K^*(892) K^*(892)$ final states which should be looked for. A second possibility that would account for the different properties of the $\xi(2220)$ seen in different experiments is that two hadronic states exist at this mass. The first would be a broader $^3F_4$ $s\bar{s}$ state which is seen in hadron beam experiments while the second would be a narrow state with high glue content seen in the gluon rich $J/\psi$ radiative decay. Further experimental results are needed to sort this out. |
1512.06382 | Robert Thorne S | R.S. Thorne | PDFs and Top Physics | 11 pages, 13 figures, to appear in proceedings of Top 2015 Workshop.
Final version. Enlarged figures and minor corrections in text | null | null | LCTS/2015-44 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | I present the results from the recent PDF4LHC study, and the resulting new
recommendation for combining PDFs sets for LHC calculations. In order to put
this into context I summarise continuing updates in PDFs. This includes
improvements and recent updates of particular PDF sets due to theory
improvements and a variety of new data sets, including most of the up-to-date
LHC data. I will emphasise particular issues relevant for top physics.
| [
{
"created": "Sun, 20 Dec 2015 15:33:24 GMT",
"version": "v1"
},
{
"created": "Tue, 10 May 2016 16:09:24 GMT",
"version": "v2"
}
] | 2016-05-11 | [
[
"Thorne",
"R. S.",
""
]
] | I present the results from the recent PDF4LHC study, and the resulting new recommendation for combining PDFs sets for LHC calculations. In order to put this into context I summarise continuing updates in PDFs. This includes improvements and recent updates of particular PDF sets due to theory improvements and a variety of new data sets, including most of the up-to-date LHC data. I will emphasise particular issues relevant for top physics. |
1612.04202 | Guang-You Qin | Lin Chen, Guang-You Qin, Shu-Yi Wei, Bo-Wen Xiao, Han-Zhong Zhang | Dijet Asymmetry in the Resummation Improved Perturbative QCD Approach | 5 pages, 4 figures | null | 10.1016/j.physletb.2018.06.002 | null | hep-ph nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We develop the first systematic theoretical approach to dijet asymmetries in
hadron-hadron collisions based on the perturbative QCD (pQCD) expansion and the
Sudakov resummation formalism. We find that the pQCD calculation at
next-to-leading order is indispensable to describe the experimental data, while
the Sudakov resummation formalism is vital near the end points where the pQCD
expansion fails to converge due to the appearance of large Sudakov logarithms.
Utilizing our resummation improved pQCD approach, we obtain good agreement with
the most up-to-date fully corrected ATLAS data on dijet asymmetry in $pp$
collisions. Combining with the BDMPS jet energy loss formalism, we extract the
value of jet transport coefficient $\hat{q}_0 \sim
2$-$6~\textrm{GeV}^2/\textrm{fm}$ for the quark-gluon-plasma created in $PbPb$
collisions at 2.76A TeV. This work paves the way for a more complete and deeper
understanding of the properties of strongly-coupled QCD medium via the studies
of dijet asymmetries in relativistic heavy-ion collisions.
| [
{
"created": "Tue, 13 Dec 2016 14:30:56 GMT",
"version": "v1"
},
{
"created": "Thu, 22 Dec 2016 08:06:48 GMT",
"version": "v2"
}
] | 2018-06-13 | [
[
"Chen",
"Lin",
""
],
[
"Qin",
"Guang-You",
""
],
[
"Wei",
"Shu-Yi",
""
],
[
"Xiao",
"Bo-Wen",
""
],
[
"Zhang",
"Han-Zhong",
""
]
] | We develop the first systematic theoretical approach to dijet asymmetries in hadron-hadron collisions based on the perturbative QCD (pQCD) expansion and the Sudakov resummation formalism. We find that the pQCD calculation at next-to-leading order is indispensable to describe the experimental data, while the Sudakov resummation formalism is vital near the end points where the pQCD expansion fails to converge due to the appearance of large Sudakov logarithms. Utilizing our resummation improved pQCD approach, we obtain good agreement with the most up-to-date fully corrected ATLAS data on dijet asymmetry in $pp$ collisions. Combining with the BDMPS jet energy loss formalism, we extract the value of jet transport coefficient $\hat{q}_0 \sim 2$-$6~\textrm{GeV}^2/\textrm{fm}$ for the quark-gluon-plasma created in $PbPb$ collisions at 2.76A TeV. This work paves the way for a more complete and deeper understanding of the properties of strongly-coupled QCD medium via the studies of dijet asymmetries in relativistic heavy-ion collisions. |
2103.09436 | Zhen-Xing Zhao | Zhen-Xing Zhao, Xiao-Yu Sun, Fu-Wei Zhang, Yi-Peng Xing, Ya-Ting Yang | Semi-leptonic form factors of $\Xi_{c}\to\Xi$ in QCD sum rules | 18 pages, 7 figures; version accepted by PRD | null | null | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | There exists a significant deviation between the most recent Lattice QCD
simulation and experimental measurement by Belle for
$\Xi_{c}^{0}\to\Xi^{-}\ell^{+}\nu_{\ell}$. In this work, we investigate the
$\Xi_{c}\to\Xi$ form factors in QCD sum rules. To this end, the two-point
correlation functions of $\Xi_{c}$ and $\Xi$, and the three-point correlation
functions of $\Xi_{c}\to\Xi$ are calculated. At the QCD level, contributions
from up to dimension-6 four-quark operators are considered, and the leading
order results of the Wilson coefficients are obtained. For the form factors,
relatively stable Borel windows can be found. Our form factors are comparable
with those of Lattice QCD, except for $f_{\perp}$. The obtained form factors
are then used to predict the branching ratios of $\Xi_{c}\to\Xi
\ell^{+}\nu_{\ell}$, and our predictions are consistent with the most recent
data of ALICE and Belle, and those of Lattice QCD within error. Given that the
branching ratios only contain limited information, we suggest the
experimentalists directly measure the form factors of $\Xi_{c}\to\Xi$.
| [
{
"created": "Wed, 17 Mar 2021 04:43:56 GMT",
"version": "v1"
},
{
"created": "Sat, 2 Dec 2023 05:29:09 GMT",
"version": "v2"
}
] | 2023-12-05 | [
[
"Zhao",
"Zhen-Xing",
""
],
[
"Sun",
"Xiao-Yu",
""
],
[
"Zhang",
"Fu-Wei",
""
],
[
"Xing",
"Yi-Peng",
""
],
[
"Yang",
"Ya-Ting",
""
]
] | There exists a significant deviation between the most recent Lattice QCD simulation and experimental measurement by Belle for $\Xi_{c}^{0}\to\Xi^{-}\ell^{+}\nu_{\ell}$. In this work, we investigate the $\Xi_{c}\to\Xi$ form factors in QCD sum rules. To this end, the two-point correlation functions of $\Xi_{c}$ and $\Xi$, and the three-point correlation functions of $\Xi_{c}\to\Xi$ are calculated. At the QCD level, contributions from up to dimension-6 four-quark operators are considered, and the leading order results of the Wilson coefficients are obtained. For the form factors, relatively stable Borel windows can be found. Our form factors are comparable with those of Lattice QCD, except for $f_{\perp}$. The obtained form factors are then used to predict the branching ratios of $\Xi_{c}\to\Xi \ell^{+}\nu_{\ell}$, and our predictions are consistent with the most recent data of ALICE and Belle, and those of Lattice QCD within error. Given that the branching ratios only contain limited information, we suggest the experimentalists directly measure the form factors of $\Xi_{c}\to\Xi$. |
1708.00435 | Haolin Li | Chien-Yi Chen, Hao-Lin Li, Michael Ramsey-Musolf | CP-Violation in the Two Higgs Doublet Model: from the LHC to EDMs | 21 pages, 34 figures | Phys. Rev. D 97, 015020 (2018) | 10.1103/PhysRevD.97.015020 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the prospective sensitivity to CP-violating Two Higgs Doublet Models
from the 14 TeV LHC and future electric dipole moment (EDM) experiments. We
concentrate on the search for a resonant heavy Higgs that decays to a $Z$ boson
and a SM-like Higgs h, leading to the $Z(\ell\ell)h(b\bar{b})$ final state. The
prospective LHC reach is analyzed using the Boosted Decision Tree method. We
illustrate the complementarity between the LHC and low energy EDM measurements
and study the dependence of the physics reach on the degree of deviation from
the alignment limit. In all cases, we find that there exists a large part of
parameter space that is sensitive to both EDMs and LHC searches.
| [
{
"created": "Tue, 1 Aug 2017 17:50:15 GMT",
"version": "v1"
},
{
"created": "Wed, 27 Sep 2017 23:33:53 GMT",
"version": "v2"
}
] | 2018-02-07 | [
[
"Chen",
"Chien-Yi",
""
],
[
"Li",
"Hao-Lin",
""
],
[
"Ramsey-Musolf",
"Michael",
""
]
] | We study the prospective sensitivity to CP-violating Two Higgs Doublet Models from the 14 TeV LHC and future electric dipole moment (EDM) experiments. We concentrate on the search for a resonant heavy Higgs that decays to a $Z$ boson and a SM-like Higgs h, leading to the $Z(\ell\ell)h(b\bar{b})$ final state. The prospective LHC reach is analyzed using the Boosted Decision Tree method. We illustrate the complementarity between the LHC and low energy EDM measurements and study the dependence of the physics reach on the degree of deviation from the alignment limit. In all cases, we find that there exists a large part of parameter space that is sensitive to both EDMs and LHC searches. |
1604.03769 | Elena Santopinto | Elena Santopinto and Alessandro Giachino | Compact pentaquark structures | 7 pages, 7 figures, Revised version:Section II has been
rewritten,Section VI it has been added. In Section VI we compute the partial
decay widths for all the predicted pentaquark resonances | Phys. Rev. D 96, 014014 (2017) | 10.1103/PhysRevD.96.014014 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the possibility that at least one of the two pentaquark structures
recently reported by LHCb can be described as a compact pentaquark state, and
we give predictions for new channels that can be studied by the
experimentalists if this hypothesis is correct. We use very general arguments
dictated by symmetry considerations, in order to describe the pentaquark states
within a group theory approach. A complete classification of all possible
states and quantum numbers, that can be useful both to the experimentalists,
for new finding, or to theoretical model builders, are given, without the
introduction of any particular dynamical model. Some prediction are finally
given using a Guersey-Radicati inspired mass formula. We reproduce the mass and
the quantum numbers of the lightest pentaquark state reported by LHCb ( 3/2^-),
with a parameter free mass formula, fixed on the well established baryons. We
predict others pentaquark resonances (giving their masses, and suggesting
possible decay channels) which belong to the same multiplet of the lightest
one.Finally, we compute the partial decay widths for all the predicted
pentaquark resonances.
| [
{
"created": "Wed, 13 Apr 2016 13:47:11 GMT",
"version": "v1"
},
{
"created": "Thu, 9 Feb 2017 19:17:16 GMT",
"version": "v2"
}
] | 2017-07-26 | [
[
"Santopinto",
"Elena",
""
],
[
"Giachino",
"Alessandro",
""
]
] | We study the possibility that at least one of the two pentaquark structures recently reported by LHCb can be described as a compact pentaquark state, and we give predictions for new channels that can be studied by the experimentalists if this hypothesis is correct. We use very general arguments dictated by symmetry considerations, in order to describe the pentaquark states within a group theory approach. A complete classification of all possible states and quantum numbers, that can be useful both to the experimentalists, for new finding, or to theoretical model builders, are given, without the introduction of any particular dynamical model. Some prediction are finally given using a Guersey-Radicati inspired mass formula. We reproduce the mass and the quantum numbers of the lightest pentaquark state reported by LHCb ( 3/2^-), with a parameter free mass formula, fixed on the well established baryons. We predict others pentaquark resonances (giving their masses, and suggesting possible decay channels) which belong to the same multiplet of the lightest one.Finally, we compute the partial decay widths for all the predicted pentaquark resonances. |
1202.3584 | Eita Nakamura | Shoji Asai, Eita Nakamura and Satoshi Shirai | Discriminating Minimal SUGRA and Minimal Gauge Mediation Models at the
Early LHC | 29 pages, 3 figures, captions improved, typos corrected, appendix
added, version published in JHEP | null | 10.1007/JHEP04(2012)003 | UT-12-05 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Among various supersymmetric (SUSY) standard models, the gravity mediation
model with a neutralino LSP and the gauge mediation model with a very light
gravitino are attractive from the cosmological view point. These models have
different scales of SUSY breaking and their underlying physics in high energy
is quite different. However, if the sparticles' decay into the gravitino is
prompt in the latter case, their collider signatures can be similar: multiple
jets and missing transverse momentum. In this paper, we study the
discrimination between these models in minimal cases at the LHC based on the
method using the significance variables in several different modes and show the
discrimination is possible at a very early stage after the discovery.
| [
{
"created": "Thu, 16 Feb 2012 13:14:10 GMT",
"version": "v1"
},
{
"created": "Fri, 9 Mar 2012 12:02:00 GMT",
"version": "v2"
}
] | 2015-06-04 | [
[
"Asai",
"Shoji",
""
],
[
"Nakamura",
"Eita",
""
],
[
"Shirai",
"Satoshi",
""
]
] | Among various supersymmetric (SUSY) standard models, the gravity mediation model with a neutralino LSP and the gauge mediation model with a very light gravitino are attractive from the cosmological view point. These models have different scales of SUSY breaking and their underlying physics in high energy is quite different. However, if the sparticles' decay into the gravitino is prompt in the latter case, their collider signatures can be similar: multiple jets and missing transverse momentum. In this paper, we study the discrimination between these models in minimal cases at the LHC based on the method using the significance variables in several different modes and show the discrimination is possible at a very early stage after the discovery. |
1302.1862 | Susan Gardner | Susan Gardner, Daheng He | Radiative Beta Decay for Studies of CP Violation | 9 pages, 1 figure | null | 10.1103/PhysRevD.87.116012 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A triple-product correlation in the radiative \beta-decay rate of neutrons or
of nuclei, characterized by the kinematic variable \xi\equiv
(\vec{l}_\nu\times\vec{l}_e)\cdot\vec{k}, where, e.g., n(p) \to p(p') +
e^-(l_e) + \bar{\nu}_e(l_\nu) + \gamma(k), can be generated by the
pseudo-Chern-Simons term found by Harvey, Hill, and Hill as a consequence of
the baryon vector current anomaly and SU(2)_{L} x U(1)_Y gauge invariance at
low energies. The correlation probes the imaginary part of its coupling
constant, so that its observation at anticipated levels of sensitivity would
reflect the presence of sources of CP violation beyond the standard model. We
compute the size of the asymmetry in n\to p e^- \bar\nu_e \gamma decay in
chiral effective theory, compare it with the computed background from
standard-model final-state interactions, and consider the new physics scenarios
which would be limited by its experimental study.
| [
{
"created": "Thu, 7 Feb 2013 20:58:51 GMT",
"version": "v1"
}
] | 2013-08-09 | [
[
"Gardner",
"Susan",
""
],
[
"He",
"Daheng",
""
]
] | A triple-product correlation in the radiative \beta-decay rate of neutrons or of nuclei, characterized by the kinematic variable \xi\equiv (\vec{l}_\nu\times\vec{l}_e)\cdot\vec{k}, where, e.g., n(p) \to p(p') + e^-(l_e) + \bar{\nu}_e(l_\nu) + \gamma(k), can be generated by the pseudo-Chern-Simons term found by Harvey, Hill, and Hill as a consequence of the baryon vector current anomaly and SU(2)_{L} x U(1)_Y gauge invariance at low energies. The correlation probes the imaginary part of its coupling constant, so that its observation at anticipated levels of sensitivity would reflect the presence of sources of CP violation beyond the standard model. We compute the size of the asymmetry in n\to p e^- \bar\nu_e \gamma decay in chiral effective theory, compare it with the computed background from standard-model final-state interactions, and consider the new physics scenarios which would be limited by its experimental study. |
hep-ph/9510374 | null | G. Knoechlein, S. Scherer, D. Drechsel (Institute for Nuclear Physics,
Johannes Gutenberg-Universitaet, Mainz, Germany) | The Anomalous Decay eta -> pi pi gamma gamma | 5 pages, revtex preprint, PS figures in separate file, presented at
the International School of Nuclear Physics, Erice, Sicily, Italy, September
1995 | Prog.Part.Nucl.Phys.36:137-139,1996 | 10.1016/0146-6410(96)00018-X | MKPH-T-95-26 | hep-ph nucl-th | null | We investigate the rare radiative eta decay modes eta -> pi+ pi- gamma gamma
and eta -> pi0 pi0 gamma gamma within the framework of chiral lagrangians at
o(p^4) and present photon spectra for both processes.
| [
{
"created": "Mon, 23 Oct 1995 16:07:33 GMT",
"version": "v1"
}
] | 2011-04-15 | [
[
"Knoechlein",
"G.",
"",
"Institute for Nuclear Physics,\n Johannes Gutenberg-Universitaet, Mainz, Germany"
],
[
"Scherer",
"S.",
"",
"Institute for Nuclear Physics,\n Johannes Gutenberg-Universitaet, Mainz, Germany"
],
[
"Drechsel",
"D.",
"",
"Institute for Nuclear Physics,\n Johannes Gutenberg-Universitaet, Mainz, Germany"
]
] | We investigate the rare radiative eta decay modes eta -> pi+ pi- gamma gamma and eta -> pi0 pi0 gamma gamma within the framework of chiral lagrangians at o(p^4) and present photon spectra for both processes. |
hep-ph/0606018 | Christian Bauer | Christian W. Bauer | Hadronic B decays from SCET | Invited plenary talk given at FPCP 2006, Vancouver, Canada | null | null | null | hep-ph | null | In this talk I will discuss non-leptonic B decays, in particular how
soft-collinear effective field theory (SCET) can be used to constrain the
non-perturbative hadronic parameters required to describe the various
observables.
| [
{
"created": "Thu, 1 Jun 2006 16:56:15 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Bauer",
"Christian W.",
""
]
] | In this talk I will discuss non-leptonic B decays, in particular how soft-collinear effective field theory (SCET) can be used to constrain the non-perturbative hadronic parameters required to describe the various observables. |
hep-ph/9612250 | Marco Stratmann | M. Stratmann (Univ. Dortmund), W. Vogelsang (Rutherford Lab) | Next-to-Leading Order Evolution of Polarized and Unpolarized
Fragmentation Functions | 31 pages, LaTeX, 3 figures, uses epsfig style | Nucl.Phys.B496:41-65,1997 | 10.1016/S0550-3213(97)00182-X | DO-TH 96/23, RAL-TR-96-097 | hep-ph | null | We determine the two-loop 'time-like' Altarelli-Parisi splitting functions,
appearing in the next-to-leading order Q^2-evolution equations for
fragmentation functions, via analytic continuation of the corresponding
'space-like' splitting functions for the evolution of parton distributions. We
do this for the case of unpolarized fragmentation functions and - for the first
time - also for the functions describing the fragmentation of a longitudinally
polarized parton into a longitudinally polarized spin-1/2 hadron such as a
Lambda baryon. Our calculation is based on the method proposed and employed by
Curci, Furmanski and Petronzio in the unpolarized case in which we confirm
their results.
| [
{
"created": "Wed, 4 Dec 1996 12:28:53 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"Stratmann",
"M.",
"",
"Univ. Dortmund"
],
[
"Vogelsang",
"W.",
"",
"Rutherford Lab"
]
] | We determine the two-loop 'time-like' Altarelli-Parisi splitting functions, appearing in the next-to-leading order Q^2-evolution equations for fragmentation functions, via analytic continuation of the corresponding 'space-like' splitting functions for the evolution of parton distributions. We do this for the case of unpolarized fragmentation functions and - for the first time - also for the functions describing the fragmentation of a longitudinally polarized parton into a longitudinally polarized spin-1/2 hadron such as a Lambda baryon. Our calculation is based on the method proposed and employed by Curci, Furmanski and Petronzio in the unpolarized case in which we confirm their results. |
hep-ph/9904493 | Clemens Heuson | C. Heuson | A structural model of quarks and leptons | 7 pages, added references, corrected typos, small changes | null | null | null | hep-ph | null | A model is proposed in which quarks, leptons and perhaps gauge bosons are
composites of magnetically charged rishons T(q=1/3) and V(q=0) with magnetic
charges g=(1,2,-3)g0. Structural formulas of composite particles and their
interactions are given, with the binding lines representing magnetic fields.
Higher generations are produced by adding rishon-antirishon pairs with the
three different magnetic charges.
| [
{
"created": "Thu, 29 Apr 1999 14:43:55 GMT",
"version": "v1"
},
{
"created": "Sat, 21 Jun 2003 12:28:01 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Heuson",
"C.",
""
]
] | A model is proposed in which quarks, leptons and perhaps gauge bosons are composites of magnetically charged rishons T(q=1/3) and V(q=0) with magnetic charges g=(1,2,-3)g0. Structural formulas of composite particles and their interactions are given, with the binding lines representing magnetic fields. Higher generations are produced by adding rishon-antirishon pairs with the three different magnetic charges. |
hep-ph/0009286 | Francesco Hautmann | J.C. Collins and F. Hautmann | Soft gluons and gauge-invariant subtractions in NLO parton-shower Monte
Carlo event generators | 11 pages, 2 figures; v2: comments and references added, results
unchanged | JHEP 0103:016,2001 | 10.1088/1126-6708/2001/03/016 | PSU-TH/230 | hep-ph | null | We address the problem of decomposing graphs in perturbative QCD into terms
associated with particular regions. Motivated by asking how to incorporate
next-to-leading order (NLO) QCD corrections in parton-shower algorithms, we
require that: (a) The integrand for the hard part is to be integrable even if
the corrections are applied to a process that is not infrared and collinear
safe. (b) The splitting between the terms should be defined gauge-invariantly.
(c) The dependence on cut-offs should obey homogeneous evolution equations. In
the context of one-gluon-emission graphs for deep inelastic scattering, we
explain a subtractive technique that is based on gauge-invariant Wilson-line
operators. Appropriate organization of subtractions involving the soft region
allows a connection to previous work where evolution equations with respect to
the directions of the Wilson lines have been derived.
| [
{
"created": "Mon, 25 Sep 2000 16:05:55 GMT",
"version": "v1"
},
{
"created": "Tue, 27 Mar 2001 00:22:45 GMT",
"version": "v2"
}
] | 2010-02-03 | [
[
"Collins",
"J. C.",
""
],
[
"Hautmann",
"F.",
""
]
] | We address the problem of decomposing graphs in perturbative QCD into terms associated with particular regions. Motivated by asking how to incorporate next-to-leading order (NLO) QCD corrections in parton-shower algorithms, we require that: (a) The integrand for the hard part is to be integrable even if the corrections are applied to a process that is not infrared and collinear safe. (b) The splitting between the terms should be defined gauge-invariantly. (c) The dependence on cut-offs should obey homogeneous evolution equations. In the context of one-gluon-emission graphs for deep inelastic scattering, we explain a subtractive technique that is based on gauge-invariant Wilson-line operators. Appropriate organization of subtractions involving the soft region allows a connection to previous work where evolution equations with respect to the directions of the Wilson lines have been derived. |
2012.03894 | Dmitri Melikhov | Wolfgang Lucha, Dmitri Melikhov, Hagop Sazdjian | OPE and quark-hadron duality for two-point functions of tetraquark
currents in $1/N_c$ expansion | 11 pages | Phys. Rev. D 103, 014012 (2021) | 10.1103/PhysRevD.103.014012 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We discuss the Operator Product Expansion (OPE) and quark-hadron duality for
two-point Green functions of tetraquark currents. We emphasize that the
factorizable part of the OPE series for such Green functions, including
nonperturbative contributions described by QCD condensates, is saturated by the
full system of ordinary hadrons and therefore cannot have any relationship to
the possible tetraquark bound states. Possible tetraquark bound states may be
contained in nonfactorizable parts of these Green functions. In the framework
of the $1/N_c$ expansion in QCD$(N_c)$, nonfactorizable parts of the two-point
Green functions of tetraquark currents provide $N_c$-suppressed contributions
compared to the $N_c$-leading factorizable parts. A possible exotic tetraquark
state may appear only in $N_c$-subleading contributions to the QCD Green
functions, in full accord with the well-known rigorous properties of
large-$N_c$ QCD.
| [
{
"created": "Mon, 7 Dec 2020 18:18:29 GMT",
"version": "v1"
}
] | 2021-01-20 | [
[
"Lucha",
"Wolfgang",
""
],
[
"Melikhov",
"Dmitri",
""
],
[
"Sazdjian",
"Hagop",
""
]
] | We discuss the Operator Product Expansion (OPE) and quark-hadron duality for two-point Green functions of tetraquark currents. We emphasize that the factorizable part of the OPE series for such Green functions, including nonperturbative contributions described by QCD condensates, is saturated by the full system of ordinary hadrons and therefore cannot have any relationship to the possible tetraquark bound states. Possible tetraquark bound states may be contained in nonfactorizable parts of these Green functions. In the framework of the $1/N_c$ expansion in QCD$(N_c)$, nonfactorizable parts of the two-point Green functions of tetraquark currents provide $N_c$-suppressed contributions compared to the $N_c$-leading factorizable parts. A possible exotic tetraquark state may appear only in $N_c$-subleading contributions to the QCD Green functions, in full accord with the well-known rigorous properties of large-$N_c$ QCD. |
1703.03929 | Long-Bin Chen | Long-Bin Chen, Yi Liang and Cong-Feng Qiao | Two-Loop integrals for CP-even heavy quarkonium production and decays | 33 pages, 2 figures | null | 10.1007/JHEP06(2017)025 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | By employing the method of differential equations, we compute the various
types of two-loop master integrals involved in CP-even heavy quarkonium
exclusive production and decays. All the integrals presented in this paper can
be casted into canonical forms and expressed in terms of Goncharov
polylogarithms and Harmonic polylogarithms. These master integrals are
frequently used in the calculation of NNLO corrections of the heavy quarkonium
production processes, as $\gamma^*\gamma\rightarrow Q\bar{Q}$,
$e^+e^-\rightarrow \gamma+ Q\bar{Q}$, and $H/Z^0\rightarrow \gamma+ Q\bar{Q}$,
and decay processes. They are also applicable in the calculation of NNLO
corrections to CP-even quarkonium inclusive production and decay processes.
| [
{
"created": "Sat, 11 Mar 2017 08:24:56 GMT",
"version": "v1"
},
{
"created": "Sat, 8 Apr 2017 12:17:26 GMT",
"version": "v2"
}
] | 2017-06-28 | [
[
"Chen",
"Long-Bin",
""
],
[
"Liang",
"Yi",
""
],
[
"Qiao",
"Cong-Feng",
""
]
] | By employing the method of differential equations, we compute the various types of two-loop master integrals involved in CP-even heavy quarkonium exclusive production and decays. All the integrals presented in this paper can be casted into canonical forms and expressed in terms of Goncharov polylogarithms and Harmonic polylogarithms. These master integrals are frequently used in the calculation of NNLO corrections of the heavy quarkonium production processes, as $\gamma^*\gamma\rightarrow Q\bar{Q}$, $e^+e^-\rightarrow \gamma+ Q\bar{Q}$, and $H/Z^0\rightarrow \gamma+ Q\bar{Q}$, and decay processes. They are also applicable in the calculation of NNLO corrections to CP-even quarkonium inclusive production and decay processes. |
hep-ph/0201184 | Seth A. Major | Tomasz J. Konopka and Seth A. Major | Observational Limits on Quantum Geometry Effects | 17 pages, 4 eps figures; v2: references updated, revision in wording;
v3: version to be published in New Jounral of Physics; v4: ref added | NewJ.Phys.4:57,2002 | 10.1088/1367-2630/4/1/357 | null | hep-ph astro-ph gr-qc | null | Using a form of modified dispersion relations derived in the context of
quantum geometry, we investigate limits set by current observations on
potential corrections to Lorentz invariance. We use a phenomological model in
which there are separate parameters for photons, leptons, and hadrons.
Constraints on these parameters are derived using thresholds for the processes
of photon stability, photon absorption, vacuum Cerenkov radiation, pion
stability, and the GZK cutoff. Although the allowed region in parameter space
is tightly constrained, non-vanishing corrections to Lorentz symmetry due to
quantum geometry are consistent with current astrophysical observations.
| [
{
"created": "Mon, 21 Jan 2002 01:55:40 GMT",
"version": "v1"
},
{
"created": "Thu, 7 Mar 2002 20:12:57 GMT",
"version": "v2"
},
{
"created": "Thu, 18 Jul 2002 16:29:52 GMT",
"version": "v3"
},
{
"created": "Wed, 31 Jul 2002 13:20:22 GMT",
"version": "v4"
}
] | 2008-11-26 | [
[
"Konopka",
"Tomasz J.",
""
],
[
"Major",
"Seth A.",
""
]
] | Using a form of modified dispersion relations derived in the context of quantum geometry, we investigate limits set by current observations on potential corrections to Lorentz invariance. We use a phenomological model in which there are separate parameters for photons, leptons, and hadrons. Constraints on these parameters are derived using thresholds for the processes of photon stability, photon absorption, vacuum Cerenkov radiation, pion stability, and the GZK cutoff. Although the allowed region in parameter space is tightly constrained, non-vanishing corrections to Lorentz symmetry due to quantum geometry are consistent with current astrophysical observations. |
2311.05939 | Sven Yannick Klein | Sven Yannick Klein | SusHi 2.0 -- Higgs production cross sections in BSM models | 10 pages, 4 figures, EPS-HEP2023 | null | null | TTK-23-30 / P3H-23-085 | hep-ph | http://creativecommons.org/licenses/by/4.0/ | A new upcoming version of SusHi is introduced. It features unified input for
the Standard Model (SM) and beyond the SM models (BSM) parameters for
higher-order total cross sections for Higgs production in gluon fusion,
heavy-quark annhilation, as well as Higgsstrahlung. Like previous versions of
SusHi, it provides links to codes like 2HDMC and FeynHiggs, but can also
process standard SLHA output of spectrum generators like SOFTSUSY and SPheno.
| [
{
"created": "Fri, 10 Nov 2023 08:52:57 GMT",
"version": "v1"
}
] | 2023-11-13 | [
[
"Klein",
"Sven Yannick",
""
]
] | A new upcoming version of SusHi is introduced. It features unified input for the Standard Model (SM) and beyond the SM models (BSM) parameters for higher-order total cross sections for Higgs production in gluon fusion, heavy-quark annhilation, as well as Higgsstrahlung. Like previous versions of SusHi, it provides links to codes like 2HDMC and FeynHiggs, but can also process standard SLHA output of spectrum generators like SOFTSUSY and SPheno. |
hep-ph/0409106 | F. Krauss | Frank Krauss, Andreas Schaelicke, Steffen Schumann, Gerhard Soff | Simulating W/Z+jets production at the Tevatron | 19 pages, 19 figures | Phys.Rev.D70:114009,2004 | 10.1103/PhysRevD.70.114009 | null | hep-ph | null | The merging procedure of tree-level matrix elements and the subsequent parton
shower as implemented in the new event generator SHERPA will be validated for
the example of W/Z+jets production at the Tevatron. Comparisons with results
obtained from other approaches and programs and with experimental results
clearly show that the merging procedure yields relevant and correct results at
both the hadron and parton levels.
| [
{
"created": "Thu, 9 Sep 2004 16:28:40 GMT",
"version": "v1"
}
] | 2011-03-23 | [
[
"Krauss",
"Frank",
""
],
[
"Schaelicke",
"Andreas",
""
],
[
"Schumann",
"Steffen",
""
],
[
"Soff",
"Gerhard",
""
]
] | The merging procedure of tree-level matrix elements and the subsequent parton shower as implemented in the new event generator SHERPA will be validated for the example of W/Z+jets production at the Tevatron. Comparisons with results obtained from other approaches and programs and with experimental results clearly show that the merging procedure yields relevant and correct results at both the hadron and parton levels. |
2106.11977 | Jorge C. Romao | Rafael Boto, Jorge C. Rom\~ao and Jo\~ao P. Silva | Current bounds on the Type-Z $Z_3$ three Higgs doublet model | 32 pages, 23 Figures in PDF. v2: impact of BFB corrected, benchmarks
added | null | 10.1103/PhysRevD.104.095006 | CFTP/21-010 | hep-ph | http://creativecommons.org/licenses/by/4.0/ | Type-Z models, where charged leptons, up type quarks, and down type quarks
each couple to a different scalar, are only possible when there are three or
more Higgs doublets. We consider the Type-Z three Higgs doublet model imposed
by a softly broken $Z_3$ symmetry. We take into account all theoretical and
experimental constraints, highlighting the importance of perturbative unitarity
and bounded from below conditions that we develop here, and which have a strong
impact on $B \rightarrow X_s \gamma$. Since there can be cancellations between
the two charged Higgs in $B \rightarrow X_s \gamma$ (and in $h \rightarrow
\gamma \gamma$), the lower bounds obtained on the charged Higgs masses are
alleviated. We also discuss in detail the important physical differences
between exact alignment and approximate alignment, and present some useful
benchmark points.
| [
{
"created": "Tue, 22 Jun 2021 18:00:01 GMT",
"version": "v1"
},
{
"created": "Fri, 23 Jul 2021 11:48:10 GMT",
"version": "v2"
}
] | 2021-11-24 | [
[
"Boto",
"Rafael",
""
],
[
"Romão",
"Jorge C.",
""
],
[
"Silva",
"João P.",
""
]
] | Type-Z models, where charged leptons, up type quarks, and down type quarks each couple to a different scalar, are only possible when there are three or more Higgs doublets. We consider the Type-Z three Higgs doublet model imposed by a softly broken $Z_3$ symmetry. We take into account all theoretical and experimental constraints, highlighting the importance of perturbative unitarity and bounded from below conditions that we develop here, and which have a strong impact on $B \rightarrow X_s \gamma$. Since there can be cancellations between the two charged Higgs in $B \rightarrow X_s \gamma$ (and in $h \rightarrow \gamma \gamma$), the lower bounds obtained on the charged Higgs masses are alleviated. We also discuss in detail the important physical differences between exact alignment and approximate alignment, and present some useful benchmark points. |
hep-ph/0007239 | Graham Shore | G.M. Shore | The Angular Momentum and g_1^p Sum Rules for the Proton | 5 pages, LaTeX, uses espcrc2.sty; invited talk at QCD00, Montpellier,
July 2000 | Nucl.Phys.Proc.Suppl. 96 (2001) 171-176 | 10.1016/S0920-5632(01)01127-6 | CERN-TH/2000-214, SWAT/00-263, UGVA-DPT-00-7-1087 | hep-ph | null | The gauge invariant operator formulation of the angular momentum sum rule
${1\over2} = J_q + J_g$ for the proton is presented and contrasted with the sum
rule for the first moment of the polarised structure function $g_1^p$. The
decoupling of the axial charge $a^0$ from the angular momentum sum rule is
highlighted and the possible QCD field-theoretic basis for an angular momentum
sum rule of the form ${1\over2} = {1\over2}\D q + \D g + L_q + L_g$ is
critically discussed.
| [
{
"created": "Fri, 21 Jul 2000 14:50:30 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Shore",
"G. M.",
""
]
] | The gauge invariant operator formulation of the angular momentum sum rule ${1\over2} = J_q + J_g$ for the proton is presented and contrasted with the sum rule for the first moment of the polarised structure function $g_1^p$. The decoupling of the axial charge $a^0$ from the angular momentum sum rule is highlighted and the possible QCD field-theoretic basis for an angular momentum sum rule of the form ${1\over2} = {1\over2}\D q + \D g + L_q + L_g$ is critically discussed. |
1910.07546 | Kohei Fujikura | Kohei Fujikura, Yuichiro Nakai, Masaki Yamada | A more attractive scheme for radion stabilization and supercooled phase
transition | 24 pages, 5 figures, v2: final version with minor corrections | null | 10.1007/JHEP02(2020)111 | MIT-CTP/5149 | hep-ph astro-ph.CO hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose a new radion stabilization mechanism in the Randall-Sundrum
spacetime, introducing a bulk ${SU(N_H)}$ gauge field which confines at a TeV
scale. It turns out that the radion is stabilized by the balance between a
brane tension and a pressure due to the Casimir energy of the strong
${SU(N_H)}$ gauge field. We investigate the phase transition between the
Randall-Sundrum (compactified) spacetime and a de-compactified spacetime and
determine the parameter regime in which eternal (old) inflation is avoided and
the phase transition can be completed. In comparison to the Goldberger-Wise
mechanism, the 5D Planck mass can be larger than the AdS curvature and a
classical description of the gravity is reliable in our stabilization
mechanism. We also discuss the effect of the phase transition in cosmology such
as an entropy dilution and a production of gravitational waves.
| [
{
"created": "Wed, 16 Oct 2019 18:00:12 GMT",
"version": "v1"
},
{
"created": "Tue, 16 Mar 2021 10:40:59 GMT",
"version": "v2"
}
] | 2021-03-17 | [
[
"Fujikura",
"Kohei",
""
],
[
"Nakai",
"Yuichiro",
""
],
[
"Yamada",
"Masaki",
""
]
] | We propose a new radion stabilization mechanism in the Randall-Sundrum spacetime, introducing a bulk ${SU(N_H)}$ gauge field which confines at a TeV scale. It turns out that the radion is stabilized by the balance between a brane tension and a pressure due to the Casimir energy of the strong ${SU(N_H)}$ gauge field. We investigate the phase transition between the Randall-Sundrum (compactified) spacetime and a de-compactified spacetime and determine the parameter regime in which eternal (old) inflation is avoided and the phase transition can be completed. In comparison to the Goldberger-Wise mechanism, the 5D Planck mass can be larger than the AdS curvature and a classical description of the gravity is reliable in our stabilization mechanism. We also discuss the effect of the phase transition in cosmology such as an entropy dilution and a production of gravitational waves. |
hep-ph/0309338 | Hideaki Iida | Hideaki Iida, Makoto Oka and Hideo Suganuma (Tokyo Inst. Tech.) | Lattice-QCD-based Schwinger-Dyson Approach for Chiral Symmetry
Restoration at Finite Temperature | Talk given at the XXI International Symposium on Lattice Field Theory
(LATTICE 2003), Tsukuba, Ibaraki, Japan, 15-19 July 2003,
Lattice2003(nonzero), 3 pages, 2 figures | null | 10.1016/S0920-5632(03)02655-0 | null | hep-ph hep-lat nucl-th | null | We propose the Schwinger-Dyson (SD) formalism based on lattice QCD, i.e.,
LQCD-based SD formalism, for the study of dynamical chiral-symmetry breaking in
QCD. We extract the kernel function K(p^2) in the SD equation from the lattice
data of the quark propagator in the Landau gauge. As remarkable features, we
find infrared vanishing and intermediate enhancement of the kernel function
K(p^2) in the SD equation. We apply the LQCD-based SD equation to thermal QCD,
and calculate the quark mass function at the finite temperature. We find chiral
symmetry restoration at the critical temperature T_c \sim 100MeV.
| [
{
"created": "Tue, 30 Sep 2003 11:29:13 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Iida",
"Hideaki",
"",
"Tokyo Inst. Tech."
],
[
"Oka",
"Makoto",
"",
"Tokyo Inst. Tech."
],
[
"Suganuma",
"Hideo",
"",
"Tokyo Inst. Tech."
]
] | We propose the Schwinger-Dyson (SD) formalism based on lattice QCD, i.e., LQCD-based SD formalism, for the study of dynamical chiral-symmetry breaking in QCD. We extract the kernel function K(p^2) in the SD equation from the lattice data of the quark propagator in the Landau gauge. As remarkable features, we find infrared vanishing and intermediate enhancement of the kernel function K(p^2) in the SD equation. We apply the LQCD-based SD equation to thermal QCD, and calculate the quark mass function at the finite temperature. We find chiral symmetry restoration at the critical temperature T_c \sim 100MeV. |
hep-ph/0610373 | Mu-Chun Chen | Mu-Chun Chen, K.T. Mahanthappa | Relating Leptogenesis to Low Energy CP Violation | 4 pages; to appear in Proceedings of SUSY06, the 14th International
Conference on Supersymmetry and the Unification of Fundamental Interactions,
UC Irvine, California, 12-17 June 2006 | AIPConf.Proc.903:303-306,2007 | 10.1063/1.2735185 | COLO-HEP-520, FERMILAB-CONF-06-389-T, UCI-TR-2006-18 | hep-ph | null | In the minimal left-right symmetric model with spontaneous CP violation,
there are only two intrinsic CP violating phases to account for all CP
violation in both the quark and lepton sectors. In addition, the left-and
right-handed Majorana mass terms for the neutrinos are proportional to each
other due to the parity in the model. This is thus a very constrained
framework, making the existence of correlations among the CP violation in
leptogenesis, neutrino oscillation and neutrinoless double beta decay possible.
| [
{
"created": "Fri, 27 Oct 2006 19:38:46 GMT",
"version": "v1"
},
{
"created": "Sun, 19 Nov 2006 20:33:47 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Chen",
"Mu-Chun",
""
],
[
"Mahanthappa",
"K. T.",
""
]
] | In the minimal left-right symmetric model with spontaneous CP violation, there are only two intrinsic CP violating phases to account for all CP violation in both the quark and lepton sectors. In addition, the left-and right-handed Majorana mass terms for the neutrinos are proportional to each other due to the parity in the model. This is thus a very constrained framework, making the existence of correlations among the CP violation in leptogenesis, neutrino oscillation and neutrinoless double beta decay possible. |
2010.05841 | Georg Wolschin | Georg Wolschin | Bottomonium spectroscopy in the quark-gluon plasma | 22 pages, 24 figures; Invited Review for Int. J. Mod. Phys. A | Int. J. Mod. Phys. A 35 (2020) 29, 2030016 | 10.1142/S0217751X20300161 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The spectroscopic properties of heavy quarkonia are substantially different
in the quark-gluon plasma (QGP) that is created in relativistic heavy-ion
collisions as compared to the vacuum situation that can be tested in pp
collisions at the same center-of-mass energy. In this article, a series of
recent works about the dissociation of the Y(nS) and chi_b(nP) states in the
hot QGP is summarized. Quarkonia dissociation occurs due to (1) screening of
the real quark-antiquark potential, (2) collisional damping through the
imaginary part of the potential, and (3) gluon-induced dissociation. In
addition, reduced feed-down plays a decisive role for the spin-triplet ground
state. Transverse-momentum and centrality-dependent data are well reproduced in
Pb-Pb collisions at LHC energies. In the asymmetric p-Pb system, alterations of
the parton density functions in the lead nucleus account for the leading
fraction of the modifications in cold nuclear matter (CNM), but the hot-medium
effects turn out to be relevant in spite of the small initial spatial extent of
the fireball, providing additional evidence for the generation of a quark-gluon
droplet.
| [
{
"created": "Mon, 12 Oct 2020 16:45:19 GMT",
"version": "v1"
}
] | 2020-11-03 | [
[
"Wolschin",
"Georg",
""
]
] | The spectroscopic properties of heavy quarkonia are substantially different in the quark-gluon plasma (QGP) that is created in relativistic heavy-ion collisions as compared to the vacuum situation that can be tested in pp collisions at the same center-of-mass energy. In this article, a series of recent works about the dissociation of the Y(nS) and chi_b(nP) states in the hot QGP is summarized. Quarkonia dissociation occurs due to (1) screening of the real quark-antiquark potential, (2) collisional damping through the imaginary part of the potential, and (3) gluon-induced dissociation. In addition, reduced feed-down plays a decisive role for the spin-triplet ground state. Transverse-momentum and centrality-dependent data are well reproduced in Pb-Pb collisions at LHC energies. In the asymmetric p-Pb system, alterations of the parton density functions in the lead nucleus account for the leading fraction of the modifications in cold nuclear matter (CNM), but the hot-medium effects turn out to be relevant in spite of the small initial spatial extent of the fireball, providing additional evidence for the generation of a quark-gluon droplet. |
0904.2727 | Nikolaos Stefanis | I. O. Cherednikov, N. G. Stefanis | Renormalization-group properties of transverse-momentum dependent parton
distribution functions in the light-cone gauge with the Mandelstam-Leibbrandt
prescription | 13 pages, 2 figures. v2 15 pages, text expanded, 2 figures added,
typos removed. v3 some remarks added in conclusions; matches version to be
published in PRD | Phys.Rev.D80:054008,2009 | 10.1103/PhysRevD.80.054008 | RUB-TPII-04/09 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The renormalization-group properties of transverse-momentum dependent parton
distribution functions in the light-cone gauge with the Mandelstam-Leibbrandt
prescription for the gluon propagator are addressed. An expression for the
transverse component of the gauge field at light-cone infinity, which plays a
crucial role in the description of the final-/initial-state interactions in the
light-cone axial gauge, is obtained. The leading-order anomalous dimension is
calculated in this gauge and the relation to the results obtained in other
gauges is worked out. It is shown that, using the Mandelstam-Leibbrandt
prescription, the ensuing anomalous dimension does not receive contributions
from extra rapidity divergences related to a cusped junction point of the
Wilson lines.
| [
{
"created": "Fri, 17 Apr 2009 15:39:54 GMT",
"version": "v1"
},
{
"created": "Wed, 24 Jun 2009 07:55:23 GMT",
"version": "v2"
},
{
"created": "Wed, 26 Aug 2009 09:03:35 GMT",
"version": "v3"
}
] | 2010-04-15 | [
[
"Cherednikov",
"I. O.",
""
],
[
"Stefanis",
"N. G.",
""
]
] | The renormalization-group properties of transverse-momentum dependent parton distribution functions in the light-cone gauge with the Mandelstam-Leibbrandt prescription for the gluon propagator are addressed. An expression for the transverse component of the gauge field at light-cone infinity, which plays a crucial role in the description of the final-/initial-state interactions in the light-cone axial gauge, is obtained. The leading-order anomalous dimension is calculated in this gauge and the relation to the results obtained in other gauges is worked out. It is shown that, using the Mandelstam-Leibbrandt prescription, the ensuing anomalous dimension does not receive contributions from extra rapidity divergences related to a cusped junction point of the Wilson lines. |
2401.07902 | Zahra Tabrizi | Joachim Kopp, Noemi Rocco, Zahra Tabrizi | Unleashing the Power of EFT in Neutrino-Nucleus Scattering | 27 pages, 3 figures | null | null | null | hep-ph hep-ex nucl-th | http://creativecommons.org/licenses/by/4.0/ | Neutrino physics is advancing into a precision era with the construction of
new experiments, particularly in the few GeV energy range. Within this energy
range, neutrinos exhibit diverse interactions with nucleons and nuclei. This
study delves in particular into neutrino--nucleus quasi-elastic cross sections,
taking into account both standard and, for the first time, non-standard
interactions, all within the framework of effective field theory (EFT). The
main uncertainties in these cross sections stem from uncertainties in the
nucleon-level form factors, and from the approximations necessary to solve the
nuclear many-body problem. We explore how these uncertainties influence the
potential of neutrino experiments to probe new physics introduced by
left-handed, right-handed, scalar, pseudoscalar, and tensor interactions. For
some of these interactions the cross section is enhanced, making long-baseline
experiments an excellent place to search for them. Our results, including
tabulated cross sections for all interaction types and all neutrino flavors,
can serve as the foundation for such searches.
| [
{
"created": "Mon, 15 Jan 2024 19:00:00 GMT",
"version": "v1"
}
] | 2024-01-17 | [
[
"Kopp",
"Joachim",
""
],
[
"Rocco",
"Noemi",
""
],
[
"Tabrizi",
"Zahra",
""
]
] | Neutrino physics is advancing into a precision era with the construction of new experiments, particularly in the few GeV energy range. Within this energy range, neutrinos exhibit diverse interactions with nucleons and nuclei. This study delves in particular into neutrino--nucleus quasi-elastic cross sections, taking into account both standard and, for the first time, non-standard interactions, all within the framework of effective field theory (EFT). The main uncertainties in these cross sections stem from uncertainties in the nucleon-level form factors, and from the approximations necessary to solve the nuclear many-body problem. We explore how these uncertainties influence the potential of neutrino experiments to probe new physics introduced by left-handed, right-handed, scalar, pseudoscalar, and tensor interactions. For some of these interactions the cross section is enhanced, making long-baseline experiments an excellent place to search for them. Our results, including tabulated cross sections for all interaction types and all neutrino flavors, can serve as the foundation for such searches. |
2307.08306 | Clemens Werthmann | Victor E. Ambru\c{s}, S\"oren Schlichting, Clemens Werthmann | System size dependence of pre-equilibrium and applicability of
hydrodynamics in heavy-ion collisions | 6 pages, 4 figures. Contribution to the HardProbes2023 conference
proceedings | null | null | null | hep-ph nucl-th | http://creativecommons.org/licenses/by-nc-nd/4.0/ | We simulate the space-time dynamics of high-energy collisions based on a
microscopic kinetic description, in order to determine the range of
applicability of an effective description in relativistic viscous
hydrodynamics. We find that hydrodynamics provides a quantitatively accurate
description of collective flow when the average inverse Reynolds number
$\mathrm{Re}^{-1}$ is sufficiently small and the early pre-equilibrium stage is
properly accounted for. By determining the breakdown of hydrodynamics as a
function of system size and energy, we find that it is quantitatively accurate
in central lead-lead collisions at LHC energies, but should not be used in
typical proton-lead or proton-proton collisions, where the development of
collective flow can not accurately be described within hydrodynamics.
| [
{
"created": "Mon, 17 Jul 2023 08:00:38 GMT",
"version": "v1"
}
] | 2023-07-18 | [
[
"Ambruş",
"Victor E.",
""
],
[
"Schlichting",
"Sören",
""
],
[
"Werthmann",
"Clemens",
""
]
] | We simulate the space-time dynamics of high-energy collisions based on a microscopic kinetic description, in order to determine the range of applicability of an effective description in relativistic viscous hydrodynamics. We find that hydrodynamics provides a quantitatively accurate description of collective flow when the average inverse Reynolds number $\mathrm{Re}^{-1}$ is sufficiently small and the early pre-equilibrium stage is properly accounted for. By determining the breakdown of hydrodynamics as a function of system size and energy, we find that it is quantitatively accurate in central lead-lead collisions at LHC energies, but should not be used in typical proton-lead or proton-proton collisions, where the development of collective flow can not accurately be described within hydrodynamics. |
hep-ph/0402076 | Iain W. Stewart | Iain W. Stewart, Margaret E. Wessling, Mark B. Wise | Stable Heavy Pentaquark States | 8 pages | Phys.Lett. B590 (2004) 185-189 | 10.1016/j.physletb.2004.03.087 | MIT-CTP-3468, CALT-68-2474 | hep-ph | null | If the Theta^+(1540) is interpreted as a bound state of a $\bar s$ quark and
two (ud) diquarks in a relative P-wave, then it is very likely that there exist
pentaquark states with a heavy antiquark, $\bar b$ or $\bar c$, and two
``light'' diquarks in a relative S-wave which are stable against strong decays.
We make a mass estimate for exotic states of this type and discuss their weak
decays. Isospin relations are constructed which test their flavor quantum
numbers.
| [
{
"created": "Mon, 9 Feb 2004 20:54:39 GMT",
"version": "v1"
}
] | 2010-04-05 | [
[
"Stewart",
"Iain W.",
""
],
[
"Wessling",
"Margaret E.",
""
],
[
"Wise",
"Mark B.",
""
]
] | If the Theta^+(1540) is interpreted as a bound state of a $\bar s$ quark and two (ud) diquarks in a relative P-wave, then it is very likely that there exist pentaquark states with a heavy antiquark, $\bar b$ or $\bar c$, and two ``light'' diquarks in a relative S-wave which are stable against strong decays. We make a mass estimate for exotic states of this type and discuss their weak decays. Isospin relations are constructed which test their flavor quantum numbers. |
1103.2055 | John Gracey | J.A. Gracey | Two loop renormalization of the n = 2 Wilson operator in the RI'/SMOM
scheme | 39 latex pages, 1 figure, 23 tables, anc directory contains txt file
with anomalous dimensions, conversion functions and data given in the tables
of the paper | JHEP 1103:109,2011 | 10.1007/JHEP03(2011)109 | LTH 910 | hep-ph hep-lat | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We compute the anomalous dimensions of the flavour non-singlet twist-2 Wilson
operators in the RI'/SMOM scheme at two loops in an arbitrary linear covariant
gauge. In addition we provide the full Green's function for these operators
inserted in a quark 2-point function at the symmetric subtraction point. The
three loop anomalous dimensions in the Landau gauge are also derived.
| [
{
"created": "Thu, 10 Mar 2011 15:13:48 GMT",
"version": "v1"
}
] | 2011-05-24 | [
[
"Gracey",
"J. A.",
""
]
] | We compute the anomalous dimensions of the flavour non-singlet twist-2 Wilson operators in the RI'/SMOM scheme at two loops in an arbitrary linear covariant gauge. In addition we provide the full Green's function for these operators inserted in a quark 2-point function at the symmetric subtraction point. The three loop anomalous dimensions in the Landau gauge are also derived. |
1602.05966 | Farinaldo Queiroz | Farinaldo S. Queiroz, Carlos E. Yaguna, Christoph Weniger | Gamma-ray Limits on Neutrino Lines | 5 pages, 3 figures. It matches published version | JCAP 1605 (2016) no.05, 050 | 10.1088/1475-7516/2016/05/050 | null | hep-ph astro-ph.HE hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | MMonochromatic neutrinos from dark matter annihilations ($\chi\chi\to
\nu\bar\nu$) are always produced in association with a gamma-ray spectrum
generated by electroweak bremsstrahlung. Consequently, these neutrino lines can
be searched for not only with neutrino detectors but also indirectly with
gamma-ray telescopes. Here, we derive limits on the dark matter annihilation
cross section into neutrinos based on recent Fermi-LAT and HESS data. We find
that, for dark matter masses above 200 GeV, gamma-ray data actually set the
most stringent constraints on neutrino lines from dark matter annihilation and,
therefore, an upper bound on the dark matter total annihilation cross section.
In addition, we point out that gamma-ray telescopes, unlike neutrino detectors,
have the potential to distinguish the flavor of the final state neutrino. Our
results indicate that we have already entered into a new era where gamma-ray
telescopes are more sensitive than neutrino detectors to neutrino lines from
dark matter annihilation.
| [
{
"created": "Thu, 18 Feb 2016 21:03:58 GMT",
"version": "v1"
},
{
"created": "Tue, 5 Jul 2016 11:51:00 GMT",
"version": "v2"
}
] | 2016-07-06 | [
[
"Queiroz",
"Farinaldo S.",
""
],
[
"Yaguna",
"Carlos E.",
""
],
[
"Weniger",
"Christoph",
""
]
] | MMonochromatic neutrinos from dark matter annihilations ($\chi\chi\to \nu\bar\nu$) are always produced in association with a gamma-ray spectrum generated by electroweak bremsstrahlung. Consequently, these neutrino lines can be searched for not only with neutrino detectors but also indirectly with gamma-ray telescopes. Here, we derive limits on the dark matter annihilation cross section into neutrinos based on recent Fermi-LAT and HESS data. We find that, for dark matter masses above 200 GeV, gamma-ray data actually set the most stringent constraints on neutrino lines from dark matter annihilation and, therefore, an upper bound on the dark matter total annihilation cross section. In addition, we point out that gamma-ray telescopes, unlike neutrino detectors, have the potential to distinguish the flavor of the final state neutrino. Our results indicate that we have already entered into a new era where gamma-ray telescopes are more sensitive than neutrino detectors to neutrino lines from dark matter annihilation. |
1608.05888 | Zachary Burell M.S. | Zachary Burell | Radiative Symmetry Breaking in the Supersymmetric Minimal B-L Extended
Standard Model | M.S. Thesis (2011). University of Alabama. Advisor: Nobuchika Okada.
arXiv admin note: text overlap with arXiv:hep-ph/9606414, arXiv:0901.0241 by
other authors; text overlap with arXiv:0907.0039 by other authors without
attribution | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The Standard Model (SM) of particle physics is a precise model of electroweak
interactions, however there is growing tension between the SM and observations
(neutrino oscillations, dark matter, dark energy, baryogenesis, among others).
There is no reason to expect the validity of the ad hoc SM to remain intact at
energy scales above a few TeV, thus a more fundamental theory will almost
certainly be required.
Motivated by these considerations, we investigate a Supersymmetric version of
a natural extension of the SM, the $U(1)_{B-L}$ model, that is obtained by
gauging the accidental B-L symmetry that exists in the ordinary SM. The
Supersymmetric $U(1)_{B-L}$ extended SM can resolve the neutrino mass problem,
the dark matter problem, the hierarchy problem, and provides a mechanism for
establishing the observed baryon asymmetry of the Universe.
When we include quantum corrections to the Higgs potential of the model, we
find that Radiative $B-L$ symmetry breaking occurs through the interplay
between large Majorana Yukawa couplings and SUSY breaking masses, and the SM
neutrino masses arise through the Type-I seesaw mechanism. We deduce from the
form RGEs that $B-L$ will be broken near the TeV scale when the Majorana Yukawa
couplings are of order 0.5, leading to TeV scale right-handed neutrinos, which
could be accessible at the LHC. We discuss the different vacua of the theory
and the viability of a right-handed neutrino dark matter candidate in the
R-parity conserving and violating sectors. A new $\mathbb{Z}_{2}$ parity is
postulated in the R-parity violating sector in which case the lightest right
handed neutrino becomes a viable Dark Matter candidate in addition to the
gravitino.
| [
{
"created": "Sun, 21 Aug 2016 02:15:45 GMT",
"version": "v1"
}
] | 2016-08-23 | [
[
"Burell",
"Zachary",
""
]
] | The Standard Model (SM) of particle physics is a precise model of electroweak interactions, however there is growing tension between the SM and observations (neutrino oscillations, dark matter, dark energy, baryogenesis, among others). There is no reason to expect the validity of the ad hoc SM to remain intact at energy scales above a few TeV, thus a more fundamental theory will almost certainly be required. Motivated by these considerations, we investigate a Supersymmetric version of a natural extension of the SM, the $U(1)_{B-L}$ model, that is obtained by gauging the accidental B-L symmetry that exists in the ordinary SM. The Supersymmetric $U(1)_{B-L}$ extended SM can resolve the neutrino mass problem, the dark matter problem, the hierarchy problem, and provides a mechanism for establishing the observed baryon asymmetry of the Universe. When we include quantum corrections to the Higgs potential of the model, we find that Radiative $B-L$ symmetry breaking occurs through the interplay between large Majorana Yukawa couplings and SUSY breaking masses, and the SM neutrino masses arise through the Type-I seesaw mechanism. We deduce from the form RGEs that $B-L$ will be broken near the TeV scale when the Majorana Yukawa couplings are of order 0.5, leading to TeV scale right-handed neutrinos, which could be accessible at the LHC. We discuss the different vacua of the theory and the viability of a right-handed neutrino dark matter candidate in the R-parity conserving and violating sectors. A new $\mathbb{Z}_{2}$ parity is postulated in the R-parity violating sector in which case the lightest right handed neutrino becomes a viable Dark Matter candidate in addition to the gravitino. |
hep-ph/0108197 | Johann Kuehn | P.A. Baikov (Moscow State Univ.), K.G. Chetyrkin (Freiburg Univ.) and
J.H. K\"uhn (Karlsruhe Univ.) | The Cross Section of e^+ e^- Annihilation into Hadrons of Order
alpha_s^4 n_f^2 in Perturbative QCD | 4 pages, revtex4 style | Phys.Rev.Lett. 88 (2002) 012001 | 10.1103/PhysRevLett.88.012001 | THEP 01/13, TTP01-19 | hep-ph | null | We present the first genuine QCD five-loop calculation of the vacuum
polarization functions: analytical terms of order alpha_s^4 n_f^2 to the
absorptive parts of vector and scalar correlators. These corrections form an
important gauge-invariant subset of the full O(alpha_s^4) correction to $e^+
e^- annihilation into hadrons and the Higgs decay rate into hadrons
respectively. They discriminate between different widely used estimates of the
full result.
| [
{
"created": "Thu, 23 Aug 2001 16:50:14 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Baikov",
"P. A.",
"",
"Moscow State Univ."
],
[
"Chetyrkin",
"K. G.",
"",
"Freiburg Univ."
],
[
"Kühn",
"J. H.",
"",
"Karlsruhe Univ."
]
] | We present the first genuine QCD five-loop calculation of the vacuum polarization functions: analytical terms of order alpha_s^4 n_f^2 to the absorptive parts of vector and scalar correlators. These corrections form an important gauge-invariant subset of the full O(alpha_s^4) correction to $e^+ e^- annihilation into hadrons and the Higgs decay rate into hadrons respectively. They discriminate between different widely used estimates of the full result. |
2102.01115 | Anke Biek\"otter | Anke Biek\"otter, Parisa Gregg, Frank Krauss and Marek Sch\"onherr | Constraining CP violating operators in charged and neutral triple gauge
couplings | 7 pages, 3 figures; v2: added Wjj channel | null | 10.1016/j.physletb.2021.136311 | IPPP/20/77, MCnet-21-01 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We constrain $C\!P$-violating charged and neutral anomalous triple gauge
couplings using LHC measurements and projections of diboson and VBF $Vjj$
production, both with subsequent leptonic decays. For triple gauge couplings
involving $W$ bosons we analyse asymmetries and interpret our results in the
SMEFT at dimension-six. For neutral triple gauge couplings, which are
dominantly constrained by high transverse-momentum bins, we present the
resulting bounds in terms of a general anomalous couplings framework.
| [
{
"created": "Mon, 1 Feb 2021 19:16:18 GMT",
"version": "v1"
},
{
"created": "Thu, 4 Mar 2021 11:47:43 GMT",
"version": "v2"
}
] | 2021-04-28 | [
[
"Biekötter",
"Anke",
""
],
[
"Gregg",
"Parisa",
""
],
[
"Krauss",
"Frank",
""
],
[
"Schönherr",
"Marek",
""
]
] | We constrain $C\!P$-violating charged and neutral anomalous triple gauge couplings using LHC measurements and projections of diboson and VBF $Vjj$ production, both with subsequent leptonic decays. For triple gauge couplings involving $W$ bosons we analyse asymmetries and interpret our results in the SMEFT at dimension-six. For neutral triple gauge couplings, which are dominantly constrained by high transverse-momentum bins, we present the resulting bounds in terms of a general anomalous couplings framework. |
2212.00056 | Benedict von Harling | Sebastian Bruggisser, Benedict von Harling, Oleksii Matsedonskyi,
Geraldine Servant | Dilaton at the LHC: Complementary Probe of Composite Higgs | 26 pages, 18 figures; v2: two plots, comments and references added,
JHEP version | null | 10.1007/JHEP05(2023)080 | DESY-22-190 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The dilaton is predicted in various extensions of the standard model
containing sectors with an approximate spontaneously-broken conformal
invariance. As a Goldstone boson of a spontaneously broken symmetry, the
dilaton can naturally be one of the lightest new physics particles, and
therefore may be the first new physics imprint observed in collider
experiments. In particular, it can arise in composite Higgs models which are
often assumed to have approximate conformal invariance in the UV. The dilaton
is then a composite state, generated by the same sector that produces the
Higgs. We continue the exploration of composite dilaton signatures at the LHC,
using the latest experimental data and analysing the future detection
prospects. We elaborate on the connection of the dilaton properties with the
properties of the Higgs potential, clarifying in particular the relation
between the scale relevant for electroweak fine tuning and the scale
controlling the dilaton couplings. This relation is then used to derive the
experimental sensitivity to the dilaton in natural composite Higgs scenarios,
which reaches ~3 TeV in dilaton mass for generic parameter choices. At the same
time, we show that dilaton searches are a complementary direction to probe
Higgs boson compositeness, with the sensitivity comparable or exceeding that of
Higgs coupling measurements.
| [
{
"created": "Wed, 30 Nov 2022 19:02:08 GMT",
"version": "v1"
},
{
"created": "Tue, 9 May 2023 16:11:58 GMT",
"version": "v2"
}
] | 2023-05-31 | [
[
"Bruggisser",
"Sebastian",
""
],
[
"von Harling",
"Benedict",
""
],
[
"Matsedonskyi",
"Oleksii",
""
],
[
"Servant",
"Geraldine",
""
]
] | The dilaton is predicted in various extensions of the standard model containing sectors with an approximate spontaneously-broken conformal invariance. As a Goldstone boson of a spontaneously broken symmetry, the dilaton can naturally be one of the lightest new physics particles, and therefore may be the first new physics imprint observed in collider experiments. In particular, it can arise in composite Higgs models which are often assumed to have approximate conformal invariance in the UV. The dilaton is then a composite state, generated by the same sector that produces the Higgs. We continue the exploration of composite dilaton signatures at the LHC, using the latest experimental data and analysing the future detection prospects. We elaborate on the connection of the dilaton properties with the properties of the Higgs potential, clarifying in particular the relation between the scale relevant for electroweak fine tuning and the scale controlling the dilaton couplings. This relation is then used to derive the experimental sensitivity to the dilaton in natural composite Higgs scenarios, which reaches ~3 TeV in dilaton mass for generic parameter choices. At the same time, we show that dilaton searches are a complementary direction to probe Higgs boson compositeness, with the sensitivity comparable or exceeding that of Higgs coupling measurements. |
2002.03937 | Avdhesh Kumar Dr | Samapan Bhadury, Wojciech Florkowski, Amaresh Jaiswal, Avdhesh Kumar
and Radoslaw Ryblewski | Relativistic dissipative spin dynamics in the relaxation time
approximation | 6 pages | Physics Letters B 814 (2021) 136096 | 10.1016/j.physletb.2021.136096 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The concept of the Wigner function is used to construct a semi-classical
kinetic theory describing the evolution of the axial-current phase-space
density of spin-1/2 particles in the relaxation time approximation. The
resulting approach can be used to study spin-polarization effects in
relativistic matter, in particular, in heavy-ion collisions. An expression for
the axial current based on the classical treatment of spin is also introduced
and we show that it is consistent with earlier calculations using Wigner
functions. Finally, we derive non-equilibrium corrections to the spin tensor,
which are used to define, for the first time, the structure of spin transport
coefficients in relativistic matter.
| [
{
"created": "Mon, 10 Feb 2020 16:46:08 GMT",
"version": "v1"
},
{
"created": "Fri, 29 Jan 2021 09:09:29 GMT",
"version": "v2"
}
] | 2021-02-01 | [
[
"Bhadury",
"Samapan",
""
],
[
"Florkowski",
"Wojciech",
""
],
[
"Jaiswal",
"Amaresh",
""
],
[
"Kumar",
"Avdhesh",
""
],
[
"Ryblewski",
"Radoslaw",
""
]
] | The concept of the Wigner function is used to construct a semi-classical kinetic theory describing the evolution of the axial-current phase-space density of spin-1/2 particles in the relaxation time approximation. The resulting approach can be used to study spin-polarization effects in relativistic matter, in particular, in heavy-ion collisions. An expression for the axial current based on the classical treatment of spin is also introduced and we show that it is consistent with earlier calculations using Wigner functions. Finally, we derive non-equilibrium corrections to the spin tensor, which are used to define, for the first time, the structure of spin transport coefficients in relativistic matter. |
hep-ph/9211317 | null | Jonathan L. Rosner and Mihir P. Worah (Enrico Fermi Institute and
Department of Physics, University of Chicago) | Model of the Quark Mixing Matrix | Presented by Mihir P. Worah at DPF 92 Meeting, Fermilab, November,
1992. 3 pages, LaTeX file | null | 10.1103/PhysRevD.46.1131 | Enrico Fermi Institute report EFI 92-62 | hep-ph | null | The structure of the Cabibbo-Kobayashi-Maskawa (CKM) matrix is analyzed from
the standpoint of a composite model. A model is constructed with three families
of quarks, by taking tensor products of sufficient numbers of spin-1/2
representations and imagining the dominant terms in the mass matrix to arise
from spin-spin interactions. Generic results then obtained include the familiar
relation $|V_{us}| = (m_d/m_s)^{1/2} - (m_u/m_c)^{1/2}$, and a less frequently
seen relation $|V_{cb}| = \sqrt{2} [(m_s/m_b) - (m_c/m_t)]$. The magnitudes of
$V_{ub}$ and $V_{td}$ come out naturally to be of the right order. The phase in
the CKM matrix can be put in by hand, but its origin remains obscure.
| [
{
"created": "Thu, 26 Nov 1992 01:30:09 GMT",
"version": "v1"
}
] | 2009-10-22 | [
[
"Rosner",
"Jonathan L.",
"",
"Enrico Fermi Institute and\n Department of Physics, University of Chicago"
],
[
"Worah",
"Mihir P.",
"",
"Enrico Fermi Institute and\n Department of Physics, University of Chicago"
]
] | The structure of the Cabibbo-Kobayashi-Maskawa (CKM) matrix is analyzed from the standpoint of a composite model. A model is constructed with three families of quarks, by taking tensor products of sufficient numbers of spin-1/2 representations and imagining the dominant terms in the mass matrix to arise from spin-spin interactions. Generic results then obtained include the familiar relation $|V_{us}| = (m_d/m_s)^{1/2} - (m_u/m_c)^{1/2}$, and a less frequently seen relation $|V_{cb}| = \sqrt{2} [(m_s/m_b) - (m_c/m_t)]$. The magnitudes of $V_{ub}$ and $V_{td}$ come out naturally to be of the right order. The phase in the CKM matrix can be put in by hand, but its origin remains obscure. |
1410.4877 | Alexei Prokudin | Zhong-Bo Kang, Alexei Prokudin, Peng Sun and Feng Yuan | Nucleon tensor charge from Collins azimuthal asymmetry measurements | Version published in Physical Review - Rapid Communications, improved
discussion, additional references and formulas added | Phys. Rev. D 91, 071501 (2015) | 10.1103/PhysRevD.91.071501 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the nucleon tensor charge from current experiments by a
combined analysis of the Collins asymmetries in two hadron production in
$e^+e^-$ annihilations and semi-inclusive hadron production in deep inelastic
scattering processes. The transverse momentum dependent evolution is taken into
account, for the first time, in the global fit of the Collins fragmentation
functions and the quark transversity distributions at the approximate
next-to-leading logarithmic order. We obtain the nucleon tensor charge
contribution from up and down quarks as $\delta u=+0.30^{+0.12}_{-0.08}$ and
$\delta d=-0.20_{-0.11}^{+0.28}$ at 90\% confidence level for momentum fraction
$0.0065 \le x_B \le 0.35$ and $Q^2=$ 10 GeV$^2$.
| [
{
"created": "Fri, 17 Oct 2014 21:57:53 GMT",
"version": "v1"
},
{
"created": "Fri, 20 Mar 2015 21:27:18 GMT",
"version": "v2"
}
] | 2015-04-16 | [
[
"Kang",
"Zhong-Bo",
""
],
[
"Prokudin",
"Alexei",
""
],
[
"Sun",
"Peng",
""
],
[
"Yuan",
"Feng",
""
]
] | We investigate the nucleon tensor charge from current experiments by a combined analysis of the Collins asymmetries in two hadron production in $e^+e^-$ annihilations and semi-inclusive hadron production in deep inelastic scattering processes. The transverse momentum dependent evolution is taken into account, for the first time, in the global fit of the Collins fragmentation functions and the quark transversity distributions at the approximate next-to-leading logarithmic order. We obtain the nucleon tensor charge contribution from up and down quarks as $\delta u=+0.30^{+0.12}_{-0.08}$ and $\delta d=-0.20_{-0.11}^{+0.28}$ at 90\% confidence level for momentum fraction $0.0065 \le x_B \le 0.35$ and $Q^2=$ 10 GeV$^2$. |
hep-ph/0308230 | Ralf W. Gothe | R.W. Gothe and S. Nussinov | Are there non-strange low-lying penta-quarks and can we understand their
width | 11 pages, 1 figure | null | null | null | hep-ph nucl-th | null | We argue that the lightest isospin 1/2 partners of the Z^+(1530) s(bar)uudd
penta-quark predicted by Diakonov, Petrov and Polyakov are not the N(1710)
mixed anti-decuplet states, but the pure non-strange u(bar)(ud)(ud) and
d(bar)(ud)(ud) penta-quark states which may lie as low as 1200 MeV. The
expected low width of a few MeV of such a putative state may explain why it was
missed in phase shift analyzes of pion-nucleon scattering.
| [
{
"created": "Fri, 22 Aug 2003 16:29:30 GMT",
"version": "v1"
},
{
"created": "Thu, 25 Sep 2003 17:52:43 GMT",
"version": "v2"
},
{
"created": "Thu, 25 Sep 2003 21:59:03 GMT",
"version": "v3"
}
] | 2007-05-23 | [
[
"Gothe",
"R. W.",
""
],
[
"Nussinov",
"S.",
""
]
] | We argue that the lightest isospin 1/2 partners of the Z^+(1530) s(bar)uudd penta-quark predicted by Diakonov, Petrov and Polyakov are not the N(1710) mixed anti-decuplet states, but the pure non-strange u(bar)(ud)(ud) and d(bar)(ud)(ud) penta-quark states which may lie as low as 1200 MeV. The expected low width of a few MeV of such a putative state may explain why it was missed in phase shift analyzes of pion-nucleon scattering. |
2112.03889 | Quentin Bonnefoy | Quentin Bonnefoy, Emanuele Gendy, Christophe Grojean, Joshua T.
Ruderman | Beyond Jarlskog: 699 invariants for CP violation in SMEFT | 25 pages + 22 pages of appendices, 13 tables. v2: additional
references, some extended discussions and fixed typos, matches JHEP version | JHEP 08 (2022) 032 | 10.1007/JHEP08(2022)032 | DESY 21-205, HU-EP-21/50 | hep-ph hep-ex hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | As SMEFT is a framework of growing importance to analyze high-energy data,
understanding its parameter space is crucial. The latter is commonly split into
CP-even and CP-odd parts, but this classification is obscured by the fact that
CP violation is actually a collective effect that is best captured by
considering flavor-invariant combinations of Lagrangian parameters. First we
show that fermion rephasing invariance imposes that several coefficients
associated to dimension-six operators can never interfere with operators of
dimension $\leq4$ and thus cannot appear in any physical observable at
$\order{1/\Lambda^2}$. For those that can, instead, we establish a one-to-one
correspondence with CP-odd flavor invariants, all linear with respect to SMEFT
coefficients. We explicitly present complete lists of such linear CP-odd
invariants, and carefully examine their relationship to CP breaking throughout
the parameter space of coefficients of dimension $\leq 4$. Requiring that these
invariants all vanish, together with the Jarlskog invariant, the strong-CP
phase, and the 6 CP-violating dimension-6 bosonic operators, provides
$699(+1+1+6)$ conditions for CP conservation to hold in any observable at
leading order, $\cO\(1/\Lambda^2\)$.
| [
{
"created": "Tue, 7 Dec 2021 18:37:50 GMT",
"version": "v1"
},
{
"created": "Thu, 25 Aug 2022 18:26:34 GMT",
"version": "v2"
}
] | 2022-08-29 | [
[
"Bonnefoy",
"Quentin",
""
],
[
"Gendy",
"Emanuele",
""
],
[
"Grojean",
"Christophe",
""
],
[
"Ruderman",
"Joshua T.",
""
]
] | As SMEFT is a framework of growing importance to analyze high-energy data, understanding its parameter space is crucial. The latter is commonly split into CP-even and CP-odd parts, but this classification is obscured by the fact that CP violation is actually a collective effect that is best captured by considering flavor-invariant combinations of Lagrangian parameters. First we show that fermion rephasing invariance imposes that several coefficients associated to dimension-six operators can never interfere with operators of dimension $\leq4$ and thus cannot appear in any physical observable at $\order{1/\Lambda^2}$. For those that can, instead, we establish a one-to-one correspondence with CP-odd flavor invariants, all linear with respect to SMEFT coefficients. We explicitly present complete lists of such linear CP-odd invariants, and carefully examine their relationship to CP breaking throughout the parameter space of coefficients of dimension $\leq 4$. Requiring that these invariants all vanish, together with the Jarlskog invariant, the strong-CP phase, and the 6 CP-violating dimension-6 bosonic operators, provides $699(+1+1+6)$ conditions for CP conservation to hold in any observable at leading order, $\cO\(1/\Lambda^2\)$. |
hep-ph/9608312 | Kevin S. McFarland | K.S. McFarland | Comment on Leptophobic Bosons and $\nu N$ Neutral Current Scattering
Data | LaTeX, 3 pages, 1 embedded PS figure, available at
http://cordelia.fnal.gov/~ksmcf/publications/moriond_comment.ps.gz .
Presented at the XXXIieme Rencontres de Moriond, Electroweak Interactions and
Unified Theories | null | null | FERMILAB-Conf-96/228 | hep-ph | null | The relevance of existing $\nu N$ deep inelastic scattering data to models
containing a leptophobic neutral vector boson is discussed. It is shown that
this neutral current data is in good agreement with the Standard Model and
disfavors such a leptophobic boson.
| [
{
"created": "Tue, 13 Aug 1996 21:23:05 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"McFarland",
"K. S.",
""
]
] | The relevance of existing $\nu N$ deep inelastic scattering data to models containing a leptophobic neutral vector boson is discussed. It is shown that this neutral current data is in good agreement with the Standard Model and disfavors such a leptophobic boson. |
1207.6252 | Brian Batell | Brian Batell, David McKeen, Maxim Pospelov | Singlet Neighbors of the Higgs Boson | 22 pages, 7 figures | null | 10.1007/JHEP10(2012)104 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The newly discovered resonance at 125 GeV has properties consistent with the
Standard Model (SM) Higgs particle, although some production and/or decay
channels currently exhibit O(1) deviations. We consider scenarios with a new
scalar singlet field with couplings to electrically charged vector-like matter,
focusing particularly on the case when the singlet mass lies within a narrow ~
few GeV window around the Higgs mass. Such a `singlet neighbor' presents novel
mechanisms for modifying the observed properties of the Higgs boson. For
instance, even a small amount of the Higgs-singlet mixing can lead to a
significant enhancement of the apparent diphoton rate. Alternatively, the Higgs
may decay into the nearby singlet, along with a very light, very soft mediator
particle, in which case there can be O(1) enhancement to the apparent diphoton
rate even for ~ TeV-scale charged vector-like matter. We also explore models in
which vector-like fermions mix with the SM leptons, causing the simultaneous
enhancement of diphoton and suppression of ditau Higgs branching ratios. Our
scenario can be tested with the accumulating LHC data by probing for the
diresonance structure of the 125 GeV diphoton signal, as well as the relative
shift in the resonance location between the diphoton and four-lepton modes.
| [
{
"created": "Thu, 26 Jul 2012 12:23:43 GMT",
"version": "v1"
}
] | 2015-06-05 | [
[
"Batell",
"Brian",
""
],
[
"McKeen",
"David",
""
],
[
"Pospelov",
"Maxim",
""
]
] | The newly discovered resonance at 125 GeV has properties consistent with the Standard Model (SM) Higgs particle, although some production and/or decay channels currently exhibit O(1) deviations. We consider scenarios with a new scalar singlet field with couplings to electrically charged vector-like matter, focusing particularly on the case when the singlet mass lies within a narrow ~ few GeV window around the Higgs mass. Such a `singlet neighbor' presents novel mechanisms for modifying the observed properties of the Higgs boson. For instance, even a small amount of the Higgs-singlet mixing can lead to a significant enhancement of the apparent diphoton rate. Alternatively, the Higgs may decay into the nearby singlet, along with a very light, very soft mediator particle, in which case there can be O(1) enhancement to the apparent diphoton rate even for ~ TeV-scale charged vector-like matter. We also explore models in which vector-like fermions mix with the SM leptons, causing the simultaneous enhancement of diphoton and suppression of ditau Higgs branching ratios. Our scenario can be tested with the accumulating LHC data by probing for the diresonance structure of the 125 GeV diphoton signal, as well as the relative shift in the resonance location between the diphoton and four-lepton modes. |
1912.10883 | Einan Gardi | Einan Gardi, Simon Caron-Huot, Joscha Reichel and Leonardo Vernazza | The High-Energy Limit of 2-to-2 Partonic Scattering Amplitudes | 19 pages, 4 figures; Proceedings of the 14th International Symposium
on Radiative Corrections (RADCOR2019) 9-13 September 2019, Palais des Papes,
Avignon, France | PoS(RADCOR2019)050 | null | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Recently, there has been significant progress in computing scattering
amplitudes in the high-energy limit using rapidity evolution equations. We
describe the state-of-the-art and demonstrate the interplay between
exponentiation of high-energy logarithms and that of infrared singularities.
The focus in this talk is the imaginary part of 2 to 2 partonic amplitudes,
which can be determined by solving the BFKL equation. We demonstrate that the
wavefunction is infrared finite, and that its evolution closes in the soft
approximation. Within this approximation we derive a closed-form solution for
the amplitude in dimensional regularization, which fixes the soft anomalous
dimension to all orders at NLL accuracy. We then turn to finite contributions
of the amplitude and show that the remaining hard contributions can be
determined algorithmically, by iteratively solving the BFKL equation in exactly
two dimensions within the class of single-valued harmonic polylogarithms. To
conclude we present numerical results and analyse large-order behaviour of the
amplitude.
| [
{
"created": "Mon, 23 Dec 2019 14:47:57 GMT",
"version": "v1"
}
] | 2019-12-24 | [
[
"Gardi",
"Einan",
""
],
[
"Caron-Huot",
"Simon",
""
],
[
"Reichel",
"Joscha",
""
],
[
"Vernazza",
"Leonardo",
""
]
] | Recently, there has been significant progress in computing scattering amplitudes in the high-energy limit using rapidity evolution equations. We describe the state-of-the-art and demonstrate the interplay between exponentiation of high-energy logarithms and that of infrared singularities. The focus in this talk is the imaginary part of 2 to 2 partonic amplitudes, which can be determined by solving the BFKL equation. We demonstrate that the wavefunction is infrared finite, and that its evolution closes in the soft approximation. Within this approximation we derive a closed-form solution for the amplitude in dimensional regularization, which fixes the soft anomalous dimension to all orders at NLL accuracy. We then turn to finite contributions of the amplitude and show that the remaining hard contributions can be determined algorithmically, by iteratively solving the BFKL equation in exactly two dimensions within the class of single-valued harmonic polylogarithms. To conclude we present numerical results and analyse large-order behaviour of the amplitude. |
0807.5112 | Almas Khan | S.M. Barr and Almas Khan | A Realistic Radiative Fermion Mass Hierarchy in Non-supersymmetric
SO(10) | 13 pages, 4 figures, RevTeX 4 | Phys.Rev.D79:115005,2009 | 10.1103/PhysRevD.79.115005 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A non-supersymmetric grand unified theory can exhibit a "radiative fermion
mass hierarchy", in which the heavier quarks and leptons get mass at tree level
and the lighter ones get mass from loop diagrams. Recently the first predictive
model of this type was proposed. Here it is analyzed numerically and it is
shown to give an excellent fit to the quark and lepton masses and mixings,
including the CP phase violating phase $\delta_{CKM}$. A relation between the
neutrino angle $\theta_{13}$ and the atmospheric neutrino angle is obtained
| [
{
"created": "Thu, 31 Jul 2008 17:10:19 GMT",
"version": "v1"
},
{
"created": "Sat, 23 Aug 2008 15:35:17 GMT",
"version": "v2"
}
] | 2009-06-30 | [
[
"Barr",
"S. M.",
""
],
[
"Khan",
"Almas",
""
]
] | A non-supersymmetric grand unified theory can exhibit a "radiative fermion mass hierarchy", in which the heavier quarks and leptons get mass at tree level and the lighter ones get mass from loop diagrams. Recently the first predictive model of this type was proposed. Here it is analyzed numerically and it is shown to give an excellent fit to the quark and lepton masses and mixings, including the CP phase violating phase $\delta_{CKM}$. A relation between the neutrino angle $\theta_{13}$ and the atmospheric neutrino angle is obtained |
2405.06958 | Niu Su | Niu Su, Hua-Xing Chen, Philipp Gubler, Atsushi Hosaka | Investigation on the $\Omega(2012)$ from QCD sum rules | 9 pages, 6 figures, 1 table, revised version to be published in PRD | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the recently observed $\Omega(2012)$ baryon in QCD sum rules. We
construct the $P$-wave $\Omega$ baryon currents with a covariant derivative,
and perform spin projection to obtain the currents with total spin 1/2 and 3/2.
We then apply the parity-projected QCD sum rules to separate the contributions
of the positive and negative parity states. We extract the masses of $J^P =
1/2^-$ and $3/2^-$ states to be $M_{1/2^-} = 2.07^{+0.07}_{-0.07}{\rm~GeV}$ and
$M_{3/2^-} = 2.05^{+0.09}_{-0.10}{\rm~GeV}$. Both results are in good agreement
with the experimental result. Therefore, it is likely that the $\Omega(2012)$
is a negative parity state, which is interpreted as a $P$-wave excited state in
the quark model. However, its spin is not determined in the present analysis,
which can be done by detailed study on its decay properties.
| [
{
"created": "Sat, 11 May 2024 08:53:04 GMT",
"version": "v1"
},
{
"created": "Thu, 18 Jul 2024 05:35:41 GMT",
"version": "v2"
}
] | 2024-07-19 | [
[
"Su",
"Niu",
""
],
[
"Chen",
"Hua-Xing",
""
],
[
"Gubler",
"Philipp",
""
],
[
"Hosaka",
"Atsushi",
""
]
] | We study the recently observed $\Omega(2012)$ baryon in QCD sum rules. We construct the $P$-wave $\Omega$ baryon currents with a covariant derivative, and perform spin projection to obtain the currents with total spin 1/2 and 3/2. We then apply the parity-projected QCD sum rules to separate the contributions of the positive and negative parity states. We extract the masses of $J^P = 1/2^-$ and $3/2^-$ states to be $M_{1/2^-} = 2.07^{+0.07}_{-0.07}{\rm~GeV}$ and $M_{3/2^-} = 2.05^{+0.09}_{-0.10}{\rm~GeV}$. Both results are in good agreement with the experimental result. Therefore, it is likely that the $\Omega(2012)$ is a negative parity state, which is interpreted as a $P$-wave excited state in the quark model. However, its spin is not determined in the present analysis, which can be done by detailed study on its decay properties. |
hep-ph/0404257 | Shahid Hussain | Shahid Hussain and Douglas W. McKay | Constraining low scale gravity with ultrahigh energy neutrinos | 3 pages, 2 figures, to appear in "Lake Louise Winter Institute 2004"
conference proceedings | null | 10.1142/9789812701961_0024 | null | hep-ph | null | We show that LSG model predictions of event ratios are clearly distinguished
from those of the SM. This is true in all models of ultrahigh energy (UHE)
neutrino sources, in both $\nu_e:\nu_{\mu}:\nu_{\tau} = 1:1:1$ and
$\nu_e:\nu_{\mu}:\nu_{\tau} = 1:2:0$ scenarios for the flux incident on earth.
In particular the ratios of upward $\mu$ events to upward shower events and the
ratios of up events to down events are different by a factor of 2 to an order
of magnitude in the comparisons between SM and LSG. $\nu_{\tau}$ rates are low
but show high sensitivity to SM vs LSG interaction physics.
| [
{
"created": "Wed, 28 Apr 2004 16:32:31 GMT",
"version": "v1"
}
] | 2017-08-23 | [
[
"Hussain",
"Shahid",
""
],
[
"McKay",
"Douglas W.",
""
]
] | We show that LSG model predictions of event ratios are clearly distinguished from those of the SM. This is true in all models of ultrahigh energy (UHE) neutrino sources, in both $\nu_e:\nu_{\mu}:\nu_{\tau} = 1:1:1$ and $\nu_e:\nu_{\mu}:\nu_{\tau} = 1:2:0$ scenarios for the flux incident on earth. In particular the ratios of upward $\mu$ events to upward shower events and the ratios of up events to down events are different by a factor of 2 to an order of magnitude in the comparisons between SM and LSG. $\nu_{\tau}$ rates are low but show high sensitivity to SM vs LSG interaction physics. |
1908.03961 | Dipankar Das | Dipankar Das | Relating the Cabibbo angle to $\tan\beta$ in a two Higgs-doublet model | 8 pages, a figure and some discussions added, version accepted for
publication in Phys. Rev. D | Phys. Rev. D 100, 075004 (2019) | 10.1103/PhysRevD.100.075004 | LU TP 19-39 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In a two Higgs-doublet model with $D_4$ flavor symmetry, we establish a
relation between $\tan\beta$ and the Cabibbo angle. Due to a small number of
parameters, the quark Yukawa sector of the model is very predictive. The flavor
changing neutral currents are small enough to allow for relatively light
nonstandard scalars to pass through the flavor constraints.
| [
{
"created": "Sun, 11 Aug 2019 21:25:58 GMT",
"version": "v1"
},
{
"created": "Mon, 23 Sep 2019 09:46:48 GMT",
"version": "v2"
}
] | 2019-10-09 | [
[
"Das",
"Dipankar",
""
]
] | In a two Higgs-doublet model with $D_4$ flavor symmetry, we establish a relation between $\tan\beta$ and the Cabibbo angle. Due to a small number of parameters, the quark Yukawa sector of the model is very predictive. The flavor changing neutral currents are small enough to allow for relatively light nonstandard scalars to pass through the flavor constraints. |
1712.07621 | Julien Baglio | Julien Baglio, Silvia Pascoli, Cedric Weiland | $W^+ W^- H$ Production at Lepton Colliders: A New Hope for Heavy Neutral
Leptons | 6 pages double-column, 4 figures. v2: more details added, matches the
published version | Eur. Phys. J. C 78 (2018) 795 | 10.1140/epjc/s10052-018-6279-x | IPPP/17/111 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the first study of the production of a Standard Model Higgs boson
at a lepton collider in association with a pair of W bosons, $e^+_{} e^-_{} \to
W^+_{} W^-_{} H$, in the inverse seesaw model. Taking into account all relevant
experimental and theoretical constraints, we find sizable effects due to the
additional heavy neutrinos up to -38% on the total cross-section at a
center-of-mass energy of 3 TeV, and even up to -66% with suitable cuts. This
motivates a detailed sensitivity analysis of the process $e^+_{} e^-_{} \to
W^+_{} W^-_{} H$ as it could provide a new, very competitive experimental probe
of low-scale neutrino mass models.
| [
{
"created": "Wed, 20 Dec 2017 18:19:26 GMT",
"version": "v1"
},
{
"created": "Thu, 4 Oct 2018 07:52:43 GMT",
"version": "v2"
}
] | 2018-10-05 | [
[
"Baglio",
"Julien",
""
],
[
"Pascoli",
"Silvia",
""
],
[
"Weiland",
"Cedric",
""
]
] | We present the first study of the production of a Standard Model Higgs boson at a lepton collider in association with a pair of W bosons, $e^+_{} e^-_{} \to W^+_{} W^-_{} H$, in the inverse seesaw model. Taking into account all relevant experimental and theoretical constraints, we find sizable effects due to the additional heavy neutrinos up to -38% on the total cross-section at a center-of-mass energy of 3 TeV, and even up to -66% with suitable cuts. This motivates a detailed sensitivity analysis of the process $e^+_{} e^-_{} \to W^+_{} W^-_{} H$ as it could provide a new, very competitive experimental probe of low-scale neutrino mass models. |
1602.04291 | Hidekazu Tanaka | Shuji Sasagawa and Hidekazu Tanaka | Schwinger-Dyson Equation in Minkowski Space beyond the IE Approximation | 9 pages, 4 figures | Prog Theor Exp Phys (2017) | 10.1093/ptep/ptw179 | RUP-16-4 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the properties of fermion mass functions in quantum
electrodynamics calculated by the Schwinger-Dyson equation in the strong
coupling region, in which the loop integration is performed in Minkowski space.
The calculated results without the instantaneous exchange approximation are
compared with those obtained by integration in Euclidean space.
| [
{
"created": "Sat, 13 Feb 2016 06:35:17 GMT",
"version": "v1"
},
{
"created": "Sat, 25 Mar 2017 06:57:53 GMT",
"version": "v2"
}
] | 2019-12-06 | [
[
"Sasagawa",
"Shuji",
""
],
[
"Tanaka",
"Hidekazu",
""
]
] | We investigate the properties of fermion mass functions in quantum electrodynamics calculated by the Schwinger-Dyson equation in the strong coupling region, in which the loop integration is performed in Minkowski space. The calculated results without the instantaneous exchange approximation are compared with those obtained by integration in Euclidean space. |
hep-ph/9710416 | null | U. Baur (SUNY Buffalo), T. Han (UC Davis), J. Ohnemus (LBL) | QCD Corrections and Anomalous Couplings in $Z\gamma$ Production at
Hadron Colliders | 47 pages, Revtex3 file, 15 postscript figures | Phys.Rev.D57:2823-2836,1998 | 10.1103/PhysRevD.57.2823 | UCD-97-20 | hep-ph | null | The processes $pp/ pbar p \to Z \gamma + X \to \ell^+ \ell^- \gamma + X$
($\ell=e, \mu$) and $pp/ pbarp \to Z \gamma + X \to \bar\nu\nu\gamma + X$ are
calculated to ${\cal O}(\alpha_s)$ for general $ZZ\gamma$ and $Z\gamma\gamma$
couplings. The impact of ${\cal O}(\alpha_s)$ QCD corrections on the
observability of $ZZ\gamma$ and $Z\gamma\gamma$ couplings in $Z\gamma$
production at the Tevatron and the Large Hadron Collider (LHC) is discussed.
| [
{
"created": "Mon, 20 Oct 1997 21:12:56 GMT",
"version": "v1"
}
] | 2011-06-07 | [
[
"Baur",
"U.",
"",
"SUNY Buffalo"
],
[
"Han",
"T.",
"",
"UC Davis"
],
[
"Ohnemus",
"J.",
"",
"LBL"
]
] | The processes $pp/ pbar p \to Z \gamma + X \to \ell^+ \ell^- \gamma + X$ ($\ell=e, \mu$) and $pp/ pbarp \to Z \gamma + X \to \bar\nu\nu\gamma + X$ are calculated to ${\cal O}(\alpha_s)$ for general $ZZ\gamma$ and $Z\gamma\gamma$ couplings. The impact of ${\cal O}(\alpha_s)$ QCD corrections on the observability of $ZZ\gamma$ and $Z\gamma\gamma$ couplings in $Z\gamma$ production at the Tevatron and the Large Hadron Collider (LHC) is discussed. |
1805.11637 | Elias Bernreuther | Elias Bernreuther and Jan Horak and Tilman Plehn and Anja Butter | Actual Physics behind Mono-X | 32 pages, 18 figures; version v2: corrected typos, added references;
version v3: added figures and references, corrected typos | SciPost Phys. 5, 034 (2018) | 10.21468/SciPostPhys.5.4.034 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Mono-X searches are standard dark matter search strategies at the LHC. First,
we show how in the case of initial state radiation they essentially collapse to
mono-jet searches. Second, we systematically study mono-X signatures from
decays of heavier dark matter states. Direct detection constraints strongly
limit our MSSM expectations, but largely vanish for mono-Z and mono-Higgs
signals once we include light NMSSM mediators. Finally, the decay topology
motivates mono-W-pair and mono-Higgs-pair searches, strengthening and
complementing their mono-X counterparts.
| [
{
"created": "Tue, 29 May 2018 18:23:09 GMT",
"version": "v1"
},
{
"created": "Thu, 14 Jun 2018 17:42:50 GMT",
"version": "v2"
},
{
"created": "Wed, 19 Sep 2018 20:06:27 GMT",
"version": "v3"
}
] | 2018-10-17 | [
[
"Bernreuther",
"Elias",
""
],
[
"Horak",
"Jan",
""
],
[
"Plehn",
"Tilman",
""
],
[
"Butter",
"Anja",
""
]
] | Mono-X searches are standard dark matter search strategies at the LHC. First, we show how in the case of initial state radiation they essentially collapse to mono-jet searches. Second, we systematically study mono-X signatures from decays of heavier dark matter states. Direct detection constraints strongly limit our MSSM expectations, but largely vanish for mono-Z and mono-Higgs signals once we include light NMSSM mediators. Finally, the decay topology motivates mono-W-pair and mono-Higgs-pair searches, strengthening and complementing their mono-X counterparts. |
hep-ph/9905214 | Yuri V. Kovchegov | Yuri V. Kovchegov (CERN / University of Minnesota) | Unitarization of the BFKL Pomeron on a Nucleus | REVTeX, 20 pages, 6 figures | Phys.Rev. D61 (2000) 074018 | 10.1103/PhysRevD.61.074018 | CERN-TH/99-166, NUC-MN-99/8-T, TPI-MINN-99/26 | hep-ph | null | We analyze the evolution equation describing all multiple hard pomeron
exchanges in a hadronic or nuclear structure functions that was proposed
earlier. We construct a perturbation series providing us with an exact solution
to the equation outside of the saturation region. The series demonstrates how
at moderately high energies the corrections to the single BFKL pomeron exchange
contribution which are due to the multiple pomeron exchanges start unitarizing
total deep inelastic scattering cross section. We show that as energy increases
the scattering cross section of the quark-antiquark pair of a fixed transverse
separation on a hadron or nucleus given by the solution of our equation inside
of the saturation region unitarizes and becomes independent of energy. The
corresponding F_2 structure function also unitarizes and becomes linearly
proportional to ln s. We also discuss possible applications of the developed
technique to diffraction.
| [
{
"created": "Mon, 3 May 1999 20:31:10 GMT",
"version": "v1"
},
{
"created": "Fri, 21 May 1999 20:39:58 GMT",
"version": "v2"
},
{
"created": "Fri, 20 Aug 1999 21:57:24 GMT",
"version": "v3"
}
] | 2009-10-31 | [
[
"Kovchegov",
"Yuri V.",
"",
"CERN / University of Minnesota"
]
] | We analyze the evolution equation describing all multiple hard pomeron exchanges in a hadronic or nuclear structure functions that was proposed earlier. We construct a perturbation series providing us with an exact solution to the equation outside of the saturation region. The series demonstrates how at moderately high energies the corrections to the single BFKL pomeron exchange contribution which are due to the multiple pomeron exchanges start unitarizing total deep inelastic scattering cross section. We show that as energy increases the scattering cross section of the quark-antiquark pair of a fixed transverse separation on a hadron or nucleus given by the solution of our equation inside of the saturation region unitarizes and becomes independent of energy. The corresponding F_2 structure function also unitarizes and becomes linearly proportional to ln s. We also discuss possible applications of the developed technique to diffraction. |
hep-ph/0301198 | Hai-Yang Cheng | Hai-Yang Cheng | Hadronic Charmed Meson Decays Involving Axial Vector Mesons | 19 pages | Phys.Rev. D67 (2003) 094007 | 10.1103/PhysRevD.67.094007 | null | hep-ph hep-ex | null | Cabibbo-allowed charmed meson decays into a pseudoscalar meson and an
axial-vector meson are studied. The charm to axial-vector meson transition form
factors are evaluated in the Isgur-Scora-Grinstein-Wise quark model. The dipole
momentum dependence of the $D\to K$ transition form factor and the presence of
a sizable long-distance $W$-exchange are the two key ingredients for
understanding the data of $D\to \bar Ka_1$. The $K_{1A}-K_{1B}$ mixing angle of
the strange axial-vector mesons is found to be $\approx \pm37^\circ$ or
$\pm58^\circ$ from $\tau\to K_1\nu_\tau$ decays. The study of $D\to
K_1(1270)\pi, K_1(1400)\pi$ decays excludes the positive mixing-angle
solutions. It is pointed out that an observation of the decay $D^0\to
K_1^-(1400)\pi^+$ at the level of $5\times 10^{-4}$ will rule out
$\theta\approx -37^\circ$ and favor the solution $\theta\approx -58^\circ$.
Though the decays $D^0\to \bar K_1^0\pi^0$ are color suppressed, they are
comparable to and even larger than the color-allowed counterparts: $\bar
K_1^0(1270)\pi^0\sim K_1^-(1270)\pi^+$ and $\bar K_1^0(1400)\pi^0>
K_1^-(1400)\pi^+$. The finite width effect of the axial-vector resonance is
examined. It becomes important for $a_1(1260)$ in particular when its width is
near 600 MeV.
| [
{
"created": "Thu, 23 Jan 2003 00:56:11 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Cheng",
"Hai-Yang",
""
]
] | Cabibbo-allowed charmed meson decays into a pseudoscalar meson and an axial-vector meson are studied. The charm to axial-vector meson transition form factors are evaluated in the Isgur-Scora-Grinstein-Wise quark model. The dipole momentum dependence of the $D\to K$ transition form factor and the presence of a sizable long-distance $W$-exchange are the two key ingredients for understanding the data of $D\to \bar Ka_1$. The $K_{1A}-K_{1B}$ mixing angle of the strange axial-vector mesons is found to be $\approx \pm37^\circ$ or $\pm58^\circ$ from $\tau\to K_1\nu_\tau$ decays. The study of $D\to K_1(1270)\pi, K_1(1400)\pi$ decays excludes the positive mixing-angle solutions. It is pointed out that an observation of the decay $D^0\to K_1^-(1400)\pi^+$ at the level of $5\times 10^{-4}$ will rule out $\theta\approx -37^\circ$ and favor the solution $\theta\approx -58^\circ$. Though the decays $D^0\to \bar K_1^0\pi^0$ are color suppressed, they are comparable to and even larger than the color-allowed counterparts: $\bar K_1^0(1270)\pi^0\sim K_1^-(1270)\pi^+$ and $\bar K_1^0(1400)\pi^0> K_1^-(1400)\pi^+$. The finite width effect of the axial-vector resonance is examined. It becomes important for $a_1(1260)$ in particular when its width is near 600 MeV. |
1902.04333 | Qin-Tao Song | S. Kumano, Qin-Tao Song and O. V. Teryaev | Hadron tomography in meson-pair production and gravitational form
factors | 6 pages, 4 figures; Proceedings of 23rd International Spin Physics
Symposium (SPIN2018), 10-14 September, 2018; Ferrara, Italy | null | null | KEK-TH-2103, J-PARC-TH-0159 | hep-ph hep-ex hep-lat nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Generalized parton distributions (GPDs) are 3-dimensional (3D) structure
functions for hadrons, and they are important for solving the proton spin
puzzle including partonic orbital-angular-momentum contributions. The $s$-$t$
crossed quantities of the GPDs are generalized distribution amplitudes (GDAs).
Here, $s$ and $t$ are Mandelstam variables. The GDAs can be studied in
two-photon processes ($\gamma^* \gamma\to h \bar h$) at KEKB. A GDA describes
the amplitude from quark and antiquark to the hadron pair $h \bar h$. In 2016,
the Belle collaboration reported measurements for pion-pair production in
electron-positron collision, and the pion GDAs were determined in this work by
analyzing the Belle data. In our analysis, the pion GDAs are expressed by a few
parameters, which are determined by analyzing the Belle data. From the obtained
GDAs, form factors of energy-momentum tenor, so called gravitational form
factors, are calculated for pion in the timelike region. The spacelike
gravitational form factors are calculated from the timelike ones by using the
dispersion relation. Then, the mass radius is calculated as 0.32-0.39 fm and
the mechanical radius, defined by the slope of the form factor $\Theta_1$, is
calculated as 0.82-0.88 fm for the pion by using the spacelike form factors.
This is the first study on gravitational form factors and radii of hadrons from
actual experimental measurements. In 2019, the Belle II collaboration will
start collecting data by the higher luminosity Super KEKB, so that the GDAs of
other hadrons should also be investigated in the near future. Our studies are
valuable in understanding 3D structure and gravitational properties of hadrons.
| [
{
"created": "Tue, 12 Feb 2019 11:13:22 GMT",
"version": "v1"
}
] | 2019-02-13 | [
[
"Kumano",
"S.",
""
],
[
"Song",
"Qin-Tao",
""
],
[
"Teryaev",
"O. V.",
""
]
] | Generalized parton distributions (GPDs) are 3-dimensional (3D) structure functions for hadrons, and they are important for solving the proton spin puzzle including partonic orbital-angular-momentum contributions. The $s$-$t$ crossed quantities of the GPDs are generalized distribution amplitudes (GDAs). Here, $s$ and $t$ are Mandelstam variables. The GDAs can be studied in two-photon processes ($\gamma^* \gamma\to h \bar h$) at KEKB. A GDA describes the amplitude from quark and antiquark to the hadron pair $h \bar h$. In 2016, the Belle collaboration reported measurements for pion-pair production in electron-positron collision, and the pion GDAs were determined in this work by analyzing the Belle data. In our analysis, the pion GDAs are expressed by a few parameters, which are determined by analyzing the Belle data. From the obtained GDAs, form factors of energy-momentum tenor, so called gravitational form factors, are calculated for pion in the timelike region. The spacelike gravitational form factors are calculated from the timelike ones by using the dispersion relation. Then, the mass radius is calculated as 0.32-0.39 fm and the mechanical radius, defined by the slope of the form factor $\Theta_1$, is calculated as 0.82-0.88 fm for the pion by using the spacelike form factors. This is the first study on gravitational form factors and radii of hadrons from actual experimental measurements. In 2019, the Belle II collaboration will start collecting data by the higher luminosity Super KEKB, so that the GDAs of other hadrons should also be investigated in the near future. Our studies are valuable in understanding 3D structure and gravitational properties of hadrons. |
1912.03511 | Tousik Samui | Aruna Kumar Nayak, Santosh Kumar Rai, Tousik Samui | Improving Heavy Dijet Resonance Searches Using Jet Substructure at the
LHC | 24 pages, 4 tables, 8 figures, published version | Eur. Phys. J. C 81 (2021) 130 | 10.1140/epjc/s10052-021-08856-9 | HRI-RECAPP-2019-005 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The search for new physics at high energy accelerators has been at the
crossroads with very little hint of signals suggesting otherwise. The
challenges at a hadronic machine such as the LHC is compounded by the fact that
final states are swamped with jets which one needs to understand and unravel. A
positive step in this direction would be to separate the jets in terms of their
gluonic and quark identities, much in a similar spirit of distinguishing heavy
quark jets from light quark jets that has helped in improving searches for both
neutral and charged Higgs bosons at the LHC. In this work, we utilise this
information using the jet substructure techniques to comment on possible
improvements in sensitivity as well as discrimination of new resonances in the
all hadronic mode that would be crucial in pinning down new physics signals at
HL-LHC, HE-LHC and any future 100 TeV hadron collider.
| [
{
"created": "Sat, 7 Dec 2019 14:34:37 GMT",
"version": "v1"
},
{
"created": "Thu, 17 Sep 2020 19:21:12 GMT",
"version": "v2"
},
{
"created": "Tue, 11 Jun 2024 09:50:22 GMT",
"version": "v3"
}
] | 2024-06-12 | [
[
"Nayak",
"Aruna Kumar",
""
],
[
"Rai",
"Santosh Kumar",
""
],
[
"Samui",
"Tousik",
""
]
] | The search for new physics at high energy accelerators has been at the crossroads with very little hint of signals suggesting otherwise. The challenges at a hadronic machine such as the LHC is compounded by the fact that final states are swamped with jets which one needs to understand and unravel. A positive step in this direction would be to separate the jets in terms of their gluonic and quark identities, much in a similar spirit of distinguishing heavy quark jets from light quark jets that has helped in improving searches for both neutral and charged Higgs bosons at the LHC. In this work, we utilise this information using the jet substructure techniques to comment on possible improvements in sensitivity as well as discrimination of new resonances in the all hadronic mode that would be crucial in pinning down new physics signals at HL-LHC, HE-LHC and any future 100 TeV hadron collider. |
0909.4159 | Fabian Eichst\"adt | Fabian Eichstaedt, Stefan Leupold and Ulrich Mosel | Phenomenological model for the Drell-Yan process: Reexamined | 15 pages, 4 figures, references added, typos corrected, minor
additions to the text, version as accepted for publication by Phys. Rev. D | Phys.Rev.D81:034002,2010 | 10.1103/PhysRevD.81.034002 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Drell-Yan pair production is investigated. We reexamine a model where the
quark momentum fraction is defined as the ratio of the corresponding light cone
components of the quark and parent nucleon in a naive parton-model approach. It
is shown that results differ from the standard parton model. This is due to
unphysical solutions for the momentum fractions within the naive approach which
are not present in the standard parton model. In a calculation employing full
quark kinematics, i.e. including primordial quark transverse momentum, these
solutions also appear. A prescription is given to handle these solutions in
order to avoid misleading results. The impact of these solutions in the full
kinematical approach is demonstrated and compared to the modified result.
| [
{
"created": "Wed, 23 Sep 2009 09:31:22 GMT",
"version": "v1"
},
{
"created": "Mon, 8 Feb 2010 12:16:14 GMT",
"version": "v2"
}
] | 2010-04-06 | [
[
"Eichstaedt",
"Fabian",
""
],
[
"Leupold",
"Stefan",
""
],
[
"Mosel",
"Ulrich",
""
]
] | Drell-Yan pair production is investigated. We reexamine a model where the quark momentum fraction is defined as the ratio of the corresponding light cone components of the quark and parent nucleon in a naive parton-model approach. It is shown that results differ from the standard parton model. This is due to unphysical solutions for the momentum fractions within the naive approach which are not present in the standard parton model. In a calculation employing full quark kinematics, i.e. including primordial quark transverse momentum, these solutions also appear. A prescription is given to handle these solutions in order to avoid misleading results. The impact of these solutions in the full kinematical approach is demonstrated and compared to the modified result. |
1912.12497 | Alexander Studenikin | Alexander Studenikin | Electromagnetic properties of neutrinos | 6 pages in LaTex, to appear in the proceedings of the European
Physical Society Conference on High Energy Physics - EPS-HEP2019 - 10-17
July, 2019, Ghent, Belgium. arXiv admin note: substantial text overlap with
arXiv:1801.08887, arXiv:1912.12501 | Pos EPS-HEP2019 374 | null | null | hep-ph astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | After a brief introduction to neutrino electromagnetic properties we focus on
the most important constraints on neutrino magnetic moments, charge radii and
millicharges from the terrestrial experiments and astrophysical considerations.
The promising new possibilities for constraining neutrino electromagnetic
properties in future experiments are also discussed.
| [
{
"created": "Sat, 28 Dec 2019 18:14:23 GMT",
"version": "v1"
}
] | 2020-09-04 | [
[
"Studenikin",
"Alexander",
""
]
] | After a brief introduction to neutrino electromagnetic properties we focus on the most important constraints on neutrino magnetic moments, charge radii and millicharges from the terrestrial experiments and astrophysical considerations. The promising new possibilities for constraining neutrino electromagnetic properties in future experiments are also discussed. |
hep-ph/9311205 | Raju | Larry McLerran and Raju Venugopalan | Gluon Distribution Functions for Very Large Nuclei at Small Transverse
Momentum | TPI--MINN--93--52/T, NUC--MINN--93--28/T, UMN--TH--1224/93, LaTex, 11
pages | Phys.Rev. D49 (1994) 3352-3355 | 10.1103/PhysRevD.49.3352 | null | hep-ph nucl-th | null | We show that the gluon distribution function for very large nuclei may be
computed for small transverse momentum as correlation functions of an
ultraviolet finite two dimensional Euclidean field theory. This computation is
valid to all orders in the density of partons per unit area, but to lowest
order in $\alpha_s$. The gluon distribution function is proportional to $1/x$,
and the effect of the finite density of partons is to modify the dependence on
transverse momentum for small transverse momentum.
| [
{
"created": "Mon, 1 Nov 1993 19:25:50 GMT",
"version": "v1"
},
{
"created": "Mon, 8 Nov 1993 15:29:52 GMT",
"version": "v2"
}
] | 2009-10-22 | [
[
"McLerran",
"Larry",
""
],
[
"Venugopalan",
"Raju",
""
]
] | We show that the gluon distribution function for very large nuclei may be computed for small transverse momentum as correlation functions of an ultraviolet finite two dimensional Euclidean field theory. This computation is valid to all orders in the density of partons per unit area, but to lowest order in $\alpha_s$. The gluon distribution function is proportional to $1/x$, and the effect of the finite density of partons is to modify the dependence on transverse momentum for small transverse momentum. |
hep-ph/0303102 | Guido Montagna | C.M. Carloni Calame, G. Montagna, O. Nicrosini and M. Treccani | Higher-order QED corrections to W-boson mass determination at hadron
colliders | 9 pages, 2 figures, 1 table, RevTeX | Phys.Rev. D69 (2004) 037301 | 10.1103/PhysRevD.69.037301 | FNT/T 2003/05 | hep-ph hep-ex | null | The impact of higher-order final-state photonic corrections on the precise
determination of the W-boson mass at the Tevatron and LHC colliders is
evaluated. In the presence of realistic selection criteria, the shift in the W
mass from a fit to the transverse mass distribution is found to be about 10 MeV
in the $W \to \mu \nu$ channel and almost negligible in the $W \to e \nu$
channel. The calculation, which is implemented in a Monte Carlo event generator
for data analysis, can contribute to reduce the uncertainty associated to the W
mass measurement at future hadron collider experiments.
| [
{
"created": "Thu, 13 Mar 2003 09:26:49 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Calame",
"C. M. Carloni",
""
],
[
"Montagna",
"G.",
""
],
[
"Nicrosini",
"O.",
""
],
[
"Treccani",
"M.",
""
]
] | The impact of higher-order final-state photonic corrections on the precise determination of the W-boson mass at the Tevatron and LHC colliders is evaluated. In the presence of realistic selection criteria, the shift in the W mass from a fit to the transverse mass distribution is found to be about 10 MeV in the $W \to \mu \nu$ channel and almost negligible in the $W \to e \nu$ channel. The calculation, which is implemented in a Monte Carlo event generator for data analysis, can contribute to reduce the uncertainty associated to the W mass measurement at future hadron collider experiments. |
hep-ph/0011179 | Kwei-Chou Yang | Hai-Yang Cheng and Kwei-Chou Yang | $B \to J/\psi K$ Decays in QCD Factorization | 18 pages, 2 figures. Typos in Eqs.(3.4), (3.5), and (3.6) are
corrected | Phys.Rev. D63 (2001) 074011 | 10.1103/PhysRevD.63.074011 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The hadronic decays $B\to J/\psi K(K^*)$ are interesting because
experimentally they are the only color-suppressed modes which have been
measured, and theoretically they are calculable by QCD factorization even the
emitted meson $J\psi$ is heavy. We analyze the decay $B\to J\psi K$ within the
framework of QCD factorization in the heavy quark limit. We show explicitly the
scale and $\gamma_5$-scheme independence of decay amplitudes and infrared
safety of nonfactorizable corrections at twist-2 order. Leading-twist
contributions from the light-cone distribution amplitudes (LCDAs) of the mesons
are too small to accommodate the data; the nonfactorizable corrections to naive
factorization are small and not significant. We study the twist-3 effects due
to the kaon and find that the coefficient $a_2(J\psi K)$ is largely enhanced by
the nonfactorizable spectator interactions arising from the twist-3 kaon LCDA
$\phi^K_\sigma$, which are formally power-suppressed but chirally,
logarithmically and kinematically enhanced. Therefore, factorization breaks
down at twist-3 order. Higher-twist effects of $J\psi$ are briefly discussed.
Our result also resolves the long-standing sign ambiguity of $a_2(J\psi K)$,
which turns out to be positive for its real part.
| [
{
"created": "Tue, 14 Nov 2000 16:09:44 GMT",
"version": "v1"
},
{
"created": "Thu, 21 Dec 2000 15:53:27 GMT",
"version": "v2"
},
{
"created": "Mon, 29 Aug 2016 07:14:12 GMT",
"version": "v3"
}
] | 2016-08-30 | [
[
"Cheng",
"Hai-Yang",
""
],
[
"Yang",
"Kwei-Chou",
""
]
] | The hadronic decays $B\to J/\psi K(K^*)$ are interesting because experimentally they are the only color-suppressed modes which have been measured, and theoretically they are calculable by QCD factorization even the emitted meson $J\psi$ is heavy. We analyze the decay $B\to J\psi K$ within the framework of QCD factorization in the heavy quark limit. We show explicitly the scale and $\gamma_5$-scheme independence of decay amplitudes and infrared safety of nonfactorizable corrections at twist-2 order. Leading-twist contributions from the light-cone distribution amplitudes (LCDAs) of the mesons are too small to accommodate the data; the nonfactorizable corrections to naive factorization are small and not significant. We study the twist-3 effects due to the kaon and find that the coefficient $a_2(J\psi K)$ is largely enhanced by the nonfactorizable spectator interactions arising from the twist-3 kaon LCDA $\phi^K_\sigma$, which are formally power-suppressed but chirally, logarithmically and kinematically enhanced. Therefore, factorization breaks down at twist-3 order. Higher-twist effects of $J\psi$ are briefly discussed. Our result also resolves the long-standing sign ambiguity of $a_2(J\psi K)$, which turns out to be positive for its real part. |
hep-ph/9305291 | Ian Kogan | Ian I. Kogan | Two Dimensional Field Theory Description of Disoriented Chiral
Condensate | 10 pages, preprint PUPT-1401, May 1993, plain LateX | Phys.Rev. D48 (1993) 3971-3975 | 10.1103/PhysRevD.48.R3971 | null | hep-ph hep-th | null | We consider the effective $1+1$-dimensional chiral theory describing
fluctuations of the order parameter of the Disoriented Chiral Condensate (DCC)
which can be formed in the central rapidity region in a relativistic
nucleus-nucleus or nucleon-nucleon collisions at high energy. Using
$1+1$-dimensional reduction of QCD at high energies and assuming spin
polarization of DDC one can find the Wess-Zumino-Novikov-Witten (WZNW) model at
level $k=3$ as the effective chiral theory for the one-dimensional DDC. Some
possible phenomenological consequences are briefly discussed.
| [
{
"created": "Thu, 20 May 1993 01:04:15 GMT",
"version": "v1"
}
] | 2016-09-01 | [
[
"Kogan",
"Ian I.",
""
]
] | We consider the effective $1+1$-dimensional chiral theory describing fluctuations of the order parameter of the Disoriented Chiral Condensate (DCC) which can be formed in the central rapidity region in a relativistic nucleus-nucleus or nucleon-nucleon collisions at high energy. Using $1+1$-dimensional reduction of QCD at high energies and assuming spin polarization of DDC one can find the Wess-Zumino-Novikov-Witten (WZNW) model at level $k=3$ as the effective chiral theory for the one-dimensional DDC. Some possible phenomenological consequences are briefly discussed. |
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