id stringlengths 9 14 | submitter stringlengths 1 56 ⌀ | authors stringlengths 5 7.68k | title stringlengths 3 299 | comments stringlengths 1 1.15k ⌀ | journal-ref stringlengths 9 298 ⌀ | doi stringlengths 12 97 ⌀ | report-no stringlengths 3 341 ⌀ | categories stringclasses 869 values | license stringclasses 9 values | orig_abstract stringlengths 16 2.44k | versions listlengths 1 39 | update_date stringlengths 10 10 | authors_parsed listlengths 1 565 | abstract stringlengths 13 2.44k |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
2007.13674 | Mariaelena Boglione | M. Boglione and A. Simonelli | Universality-breaking effects in $e^+e^-$ hadronic production processes | 60 pages, 15 figures, revised argument in section 6 - results
unchanged, 1 figure added in section 3, references added, typos corrected | null | 10.1140/epjc/s10052-020-08821-y | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Recent BELLE measurements provide the cross section for single hadron
production in $e^+e^-$ annihilations, differential in thrust and in the hadron
transverse momentum with respect to the thrust axis. Universality breaking
effects due to process-dependent soft factors make it very difficult to relate
this cross sections to those corresponding to hadron-pair production in
$e^+e^-$ annihilations, where transverse momentum dependent (TMD) factorization
can be applied. The correspondence between these two cross sections is examined
in the framework of the Collins-Soper-Sterman factorization, in the collinear
as well as in the TMD approach. We propose a scheme that allows to relate the
TMD parton densities defined in 1-hadron and in 2-hadron processes, neatly
separating, within the soft and collinear parts, the non-perturbative terms
from the contributions that can be calculated perturbatively. The
regularization of rapidity divergences introduces cut-offs, the arbitrariness
of which will be properly reabsorbed by means of a mechanism closely
reminiscent of a gauge transformation. In this way, we restore the possibility
to perform global phenomenological studies of TMD physics, simultaneously
analyzing data belonging to different hadron classes.
| [
{
"created": "Mon, 27 Jul 2020 16:43:05 GMT",
"version": "v1"
},
{
"created": "Sun, 1 Nov 2020 18:34:23 GMT",
"version": "v2"
}
] | 2021-02-24 | [
[
"Boglione",
"M.",
""
],
[
"Simonelli",
"A.",
""
]
] | Recent BELLE measurements provide the cross section for single hadron production in $e^+e^-$ annihilations, differential in thrust and in the hadron transverse momentum with respect to the thrust axis. Universality breaking effects due to process-dependent soft factors make it very difficult to relate this cross sections to those corresponding to hadron-pair production in $e^+e^-$ annihilations, where transverse momentum dependent (TMD) factorization can be applied. The correspondence between these two cross sections is examined in the framework of the Collins-Soper-Sterman factorization, in the collinear as well as in the TMD approach. We propose a scheme that allows to relate the TMD parton densities defined in 1-hadron and in 2-hadron processes, neatly separating, within the soft and collinear parts, the non-perturbative terms from the contributions that can be calculated perturbatively. The regularization of rapidity divergences introduces cut-offs, the arbitrariness of which will be properly reabsorbed by means of a mechanism closely reminiscent of a gauge transformation. In this way, we restore the possibility to perform global phenomenological studies of TMD physics, simultaneously analyzing data belonging to different hadron classes. |
hep-ph/9609371 | Geoffrey Bodwin | G.T. Bodwin, D.K. Sinclair, S. Kim | Lattice Calculation of Quarkonium Decay Matrix Elements | 10 pages, LaTeX. Talk presented at the Quarkonium Physics Workshop,
University of Illinois, Chicago, June 13-15, 1996 | Int.J.Mod.Phys.A12:4019-4028,1997 | 10.1142/S0217751X97002176 | ANL-HEP-PR-96-79 | hep-ph hep-lat | null | We calculate the NRQCD matrix elements for the decays of the lowest-lying S-
and P-wave states of charmonium and bottomonium in quenched lattice QCD. We
also compute the one-loop relations between the lattice and continuum matrix
elements.
| [
{
"created": "Mon, 16 Sep 1996 19:17:39 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Bodwin",
"G. T.",
""
],
[
"Sinclair",
"D. K.",
""
],
[
"Kim",
"S.",
""
]
] | We calculate the NRQCD matrix elements for the decays of the lowest-lying S- and P-wave states of charmonium and bottomonium in quenched lattice QCD. We also compute the one-loop relations between the lattice and continuum matrix elements. |
hep-ph/0209129 | Ana M. Teixeira | Ana M. Teixeira | Spontaneous CP violation in supersymmetric models | 10 pages, 2 eps figures. Talk given at Corfu Summer Institute on
Elementary Particle Physics (Corfu 2001), Corfu, Greece, 31 Aug - 20 Sep 2001 | null | null | null | hep-ph | null | We briefly comment on the question of spontaneous CP violation for several
models of weak interactions. We focus on one of the minimal extensions of the
Standard Model where spontaneous CP violation is viable,the next-to-minimal
supersymmetric standard model (NMSSM), with two Higgs doublets and a gauge
singlet. We analyse the most general Higgs potential without a discrete Z_3
symmetry, and derive an upper bound on the mass of the lightest neutral Higgs
boson. We estimate $\epsilon_K$ by applying the mass insertion approximation,
finding that in order to account for the observed CP violation in the neutral
kaon sector a non-trivial flavour structure in the soft-breaking A-terms is
required and that the upper bound on the lightest Higgs-boson mass becomes
stronger. We also discuss the implications of electric dipole moments of the
electron and the neutron in SUSY models with SCPV.
| [
{
"created": "Thu, 12 Sep 2002 09:39:11 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Teixeira",
"Ana M.",
""
]
] | We briefly comment on the question of spontaneous CP violation for several models of weak interactions. We focus on one of the minimal extensions of the Standard Model where spontaneous CP violation is viable,the next-to-minimal supersymmetric standard model (NMSSM), with two Higgs doublets and a gauge singlet. We analyse the most general Higgs potential without a discrete Z_3 symmetry, and derive an upper bound on the mass of the lightest neutral Higgs boson. We estimate $\epsilon_K$ by applying the mass insertion approximation, finding that in order to account for the observed CP violation in the neutral kaon sector a non-trivial flavour structure in the soft-breaking A-terms is required and that the upper bound on the lightest Higgs-boson mass becomes stronger. We also discuss the implications of electric dipole moments of the electron and the neutron in SUSY models with SCPV. |
1712.08334 | Jean Cleymans | T. Bhattacharyya, J. Cleymans, S. Mogliacci, A.S. Parvan, A.S. Sorin,
O.V. Teryaev | Non-extensivity of the QCD pT spectra | 4 pages | null | 10.1140/epja/i2018-12647-6 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We try to establish a connection between the hadronic distributions, in
proton-proton collisions at very high transverse momentum $p_{\mathrm{T}}$,
obtained via perturbative QCD and the Tsallis non extensive statistics. Our
motivation is that while the former is expected to be valid at extremely high
momentum, due to asymptotic freedom, the latter has been very successful in
describing experimental spectra over a wide range of momentum. Matching the non
extensive statistics with the asymptotic $p_{\mathrm{T}}$ behaviour expected
from QCD leads to the value of $q=1.25$.
| [
{
"created": "Fri, 22 Dec 2017 08:07:51 GMT",
"version": "v1"
},
{
"created": "Mon, 9 Jul 2018 14:09:13 GMT",
"version": "v2"
},
{
"created": "Sat, 27 Oct 2018 18:36:33 GMT",
"version": "v3"
}
] | 2019-01-30 | [
[
"Bhattacharyya",
"T.",
""
],
[
"Cleymans",
"J.",
""
],
[
"Mogliacci",
"S.",
""
],
[
"Parvan",
"A. S.",
""
],
[
"Sorin",
"A. S.",
""
],
[
"Teryaev",
"O. V.",
""
]
] | We try to establish a connection between the hadronic distributions, in proton-proton collisions at very high transverse momentum $p_{\mathrm{T}}$, obtained via perturbative QCD and the Tsallis non extensive statistics. Our motivation is that while the former is expected to be valid at extremely high momentum, due to asymptotic freedom, the latter has been very successful in describing experimental spectra over a wide range of momentum. Matching the non extensive statistics with the asymptotic $p_{\mathrm{T}}$ behaviour expected from QCD leads to the value of $q=1.25$. |
1512.02557 | Dennis Sivers Dr. | Dennis Sivers | Spin-Directed Momentum Transfers in SIDIS Baryon Production | 7 pages with 3 figures. Contribution to POETIC16 Conference | null | 10.1051/epjconf/201611201017 | PPI15-4 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The measurement of transverse single-spin asymmetries for baryon production
in the target fragmentation region of semi-inclusive deep-inelastic scattering
(SIDIS), can produce important insight into those nonperturbative aspects of
QCD directly associated with confinement and with the dynamical breaking of
chiral symmetry. We discuss here, interns of spin-directed momentum transfers,
the powerful quantum field-theoretical constraints on the spin-orbit dynamics
underlying these transverse spin observables. The spin-directed momentum
shifts, originating either in the target nucleon or in the QCD jets produced in
the deep inelastic scattering process, represent significant quantum
entanglement effects connecting information from current fragmentation with
observables in target fragmentation.
| [
{
"created": "Tue, 8 Dec 2015 17:29:27 GMT",
"version": "v1"
}
] | 2016-04-20 | [
[
"Sivers",
"Dennis",
""
]
] | The measurement of transverse single-spin asymmetries for baryon production in the target fragmentation region of semi-inclusive deep-inelastic scattering (SIDIS), can produce important insight into those nonperturbative aspects of QCD directly associated with confinement and with the dynamical breaking of chiral symmetry. We discuss here, interns of spin-directed momentum transfers, the powerful quantum field-theoretical constraints on the spin-orbit dynamics underlying these transverse spin observables. The spin-directed momentum shifts, originating either in the target nucleon or in the QCD jets produced in the deep inelastic scattering process, represent significant quantum entanglement effects connecting information from current fragmentation with observables in target fragmentation. |
2005.12146 | Mauro Chiesa | Mauro Chiesa, Carlo Oleari, Emanuele Re | NLO QCD+NLO EW corrections to diboson production matched to parton
shower | Added figs.6-7. Extended discussion in sect.5. Matches version
published on epjc | null | 10.1140/epjc/s10052-020-8419-3 | LAPTH-025/20 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the matching of NLO QCD and NLO EW corrections to parton showers
for vector-boson pair production at the LHC. We consider leptonic final states,
including resonant and non-resonant diagrams, spin correlations and off-shell
effects. Our results are obtained interfacing the Recola2-Collier one-loop
provider with the POWHEG-BOX-RES framework. We discuss our implementation, we
validate it at fixed order, and we show our final results matched to parton
shower. A by-product of our work is also a general interface between
Recola2-Collier and POWHEG-BOX-RES. This is the first time that EW and QCD
corrections to diboson production are consistently matched to parton showers.
| [
{
"created": "Mon, 25 May 2020 14:45:41 GMT",
"version": "v1"
},
{
"created": "Wed, 23 Sep 2020 12:01:30 GMT",
"version": "v2"
}
] | 2020-09-24 | [
[
"Chiesa",
"Mauro",
""
],
[
"Oleari",
"Carlo",
""
],
[
"Re",
"Emanuele",
""
]
] | We present the matching of NLO QCD and NLO EW corrections to parton showers for vector-boson pair production at the LHC. We consider leptonic final states, including resonant and non-resonant diagrams, spin correlations and off-shell effects. Our results are obtained interfacing the Recola2-Collier one-loop provider with the POWHEG-BOX-RES framework. We discuss our implementation, we validate it at fixed order, and we show our final results matched to parton shower. A by-product of our work is also a general interface between Recola2-Collier and POWHEG-BOX-RES. This is the first time that EW and QCD corrections to diboson production are consistently matched to parton showers. |
hep-ph/9506367 | Rajeev Bhalerao | R. S. Bhalerao (TIFR, Bombay) | Parton Gas Model for the Nucleon Structure Functions | Revtex, 11 pages + 3 figures (available on request) | null | 10.1016/0370-2693(96)01206-3 | TIFR/TH/95-28, 18 June 1995 | hep-ph nucl-th | null | A phenomenological model for the nucleon structure functions is presented.
Visualising the nucleon as a cavity filled with parton gas in thermal
equilibrium and parametrizing the effects due to the finiteness of the nucleon
volume, we obtain a good fit to the data on the unpolarized nucleon structure
functions.
| [
{
"created": "Tue, 20 Jun 1995 11:29:22 GMT",
"version": "v1"
},
{
"created": "Sat, 1 Jul 1995 17:49:10 GMT",
"version": "v2"
}
] | 2009-10-28 | [
[
"Bhalerao",
"R. S.",
"",
"TIFR, Bombay"
]
] | A phenomenological model for the nucleon structure functions is presented. Visualising the nucleon as a cavity filled with parton gas in thermal equilibrium and parametrizing the effects due to the finiteness of the nucleon volume, we obtain a good fit to the data on the unpolarized nucleon structure functions. |
1302.3667 | Yi Liao | Wen-Tao Hou (Nankai U., USTC), Yi Liao (Nankai U.), Hong-Jun Liu
(Nankai U.) | Gauge Independence of Magnetic Moment and Vanishing Charge of Dirac
Neutrinos: an Exact One-loop Demonstration | 14 pages, 2 figures | Phys. Rev. D 87, 073001 (2013) | 10.1103/PhysRevD.87.073001 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The magnetic moment and vanishing charge of a Dirac neutrino are physically
observable quantities and must not depend on the choice of gauge in a
consistent quantum field theory. We verify this statement explicitly at the one
loop level in both R_xi and unitary gauges of the minimally extended standard
model. We accomplish this by manipulating directly the integrands of loop
integrals and employing simple algebraic identities and integral relations. Our
result generally applies for any masses of the relevant particles and unitary
neutrino mixing.
| [
{
"created": "Fri, 15 Feb 2013 03:42:15 GMT",
"version": "v1"
}
] | 2013-08-02 | [
[
"Hou",
"Wen-Tao",
"",
"Nankai U., USTC"
],
[
"Liao",
"Yi",
"",
"Nankai U."
],
[
"Liu",
"Hong-Jun",
"",
"Nankai U."
]
] | The magnetic moment and vanishing charge of a Dirac neutrino are physically observable quantities and must not depend on the choice of gauge in a consistent quantum field theory. We verify this statement explicitly at the one loop level in both R_xi and unitary gauges of the minimally extended standard model. We accomplish this by manipulating directly the integrands of loop integrals and employing simple algebraic identities and integral relations. Our result generally applies for any masses of the relevant particles and unitary neutrino mixing. |
hep-ph/0605133 | Boris Ermolaev | B.I.Ermolaev, M. Greco, S.I. Troyan | Singlet structure function g_1 at small x and small Q^2 | Section 2 is totally changed, one more ref added | Eur.Phys.J.C50:823-828,2007 | 10.1140/epjc/s10052-007-0251-5 | null | hep-ph | null | Explicit expressions for the singlet g_1 at small x and small Q^2 are
obtained with the total resummation of the leading logarithmic contributions.
It is shown that g_1 practically does not depend on Q^2 in this kinematic
region. In contrast, it would be interesting to investigate its dependence on
the invariant energy 2pq because, being g_1 positive at small 2pq, it can turn
negative at greater values of this variable. The position of the turning point
is sensitive to the ratio between the initial quark and gluon densities, so its
experimental detection would enable to estimate this ratio
| [
{
"created": "Thu, 11 May 2006 15:42:00 GMT",
"version": "v1"
},
{
"created": "Wed, 17 May 2006 12:29:10 GMT",
"version": "v2"
},
{
"created": "Mon, 3 Jul 2006 07:53:01 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Ermolaev",
"B. I.",
""
],
[
"Greco",
"M.",
""
],
[
"Troyan",
"S. I.",
""
]
] | Explicit expressions for the singlet g_1 at small x and small Q^2 are obtained with the total resummation of the leading logarithmic contributions. It is shown that g_1 practically does not depend on Q^2 in this kinematic region. In contrast, it would be interesting to investigate its dependence on the invariant energy 2pq because, being g_1 positive at small 2pq, it can turn negative at greater values of this variable. The position of the turning point is sensitive to the ratio between the initial quark and gluon densities, so its experimental detection would enable to estimate this ratio |
1202.1301 | Marco Drewes | Marco Drewes, Sebastian Mendizabal, Christoph Weniger | The Boltzmann Equation from Quantum Field Theory | title changed, discussion extended and example added, references
added | Physics Letters B 718 (2013) 1119-1124 | 10.1016/j.physletb.2012.11.046 | MPP-2012-3; TTK-12-03; TUM-HEP-857/12 | hep-ph astro-ph.CO cond-mat.stat-mech quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We show from first principles the emergence of classical Boltzmann equations
from relativistic nonequilibrium quantum field theory as described by the
Kadanoff-Baym equations. Our method applies to a generic quantum field, coupled
to a collection of background fields and sources, in a homogeneous and
isotropic spacetime. The analysis is based on analytical solutions to the full
Kadanoff-Baym equations, using the WKB approximation. This is in contrast to
previous derivations of kinetic equations that rely on similar physical
assumptions, but obtain approximate equations of motion from a gradient
expansion in momentum space. We show that the system follows a generalized
Boltzmann equation whenever the WKB approximation holds. The generalized
Boltzmann equation, which includes off-shell transport, is valid far from
equilibrium and in a time dependent background, such as the expanding universe.
| [
{
"created": "Mon, 6 Feb 2012 21:42:12 GMT",
"version": "v1"
},
{
"created": "Tue, 11 Dec 2012 21:00:07 GMT",
"version": "v2"
}
] | 2012-12-20 | [
[
"Drewes",
"Marco",
""
],
[
"Mendizabal",
"Sebastian",
""
],
[
"Weniger",
"Christoph",
""
]
] | We show from first principles the emergence of classical Boltzmann equations from relativistic nonequilibrium quantum field theory as described by the Kadanoff-Baym equations. Our method applies to a generic quantum field, coupled to a collection of background fields and sources, in a homogeneous and isotropic spacetime. The analysis is based on analytical solutions to the full Kadanoff-Baym equations, using the WKB approximation. This is in contrast to previous derivations of kinetic equations that rely on similar physical assumptions, but obtain approximate equations of motion from a gradient expansion in momentum space. We show that the system follows a generalized Boltzmann equation whenever the WKB approximation holds. The generalized Boltzmann equation, which includes off-shell transport, is valid far from equilibrium and in a time dependent background, such as the expanding universe. |
hep-ph/0307383 | Xiangdong Ji | A. V. Belitsky, Xiangdong Ji, and Feng Yuan | Quark Imaging in the Proton Via Quantum Phase-Space Distributions | 20 pages with 3 fitures | Phys.Rev.D69:074014,2004 | 10.1103/PhysRevD.69.074014 | null | hep-ph | null | We develop the concept of quantum phase-space (Wigner) distributions for
quarks and gluons in the proton. To appreciate their physical content, we
analyze the contraints from special relativity on the interpretation of elastic
form factors, and examine the physics of the Feynman parton distributions in
the proton's rest frame. We relate the quark Wigner functions to the
transverse-momentum dependent parton distributions and generalized parton
distributions, emphasizing the physical role of the skewness parameter. We show
that the Wigner functions allow to visualize quantum quarks and gluons using
the language of the classical phase space. We present two examples of the quark
Wigner distributions and point out some model-independent features.
| [
{
"created": "Thu, 31 Jul 2003 04:07:09 GMT",
"version": "v1"
}
] | 2011-05-05 | [
[
"Belitsky",
"A. V.",
""
],
[
"Ji",
"Xiangdong",
""
],
[
"Yuan",
"Feng",
""
]
] | We develop the concept of quantum phase-space (Wigner) distributions for quarks and gluons in the proton. To appreciate their physical content, we analyze the contraints from special relativity on the interpretation of elastic form factors, and examine the physics of the Feynman parton distributions in the proton's rest frame. We relate the quark Wigner functions to the transverse-momentum dependent parton distributions and generalized parton distributions, emphasizing the physical role of the skewness parameter. We show that the Wigner functions allow to visualize quantum quarks and gluons using the language of the classical phase space. We present two examples of the quark Wigner distributions and point out some model-independent features. |
0805.0097 | Kfir Blum | Kfir Blum and Yosef Nir | Beyond MSSM Baryogenesis | 20 pages, 2 figures; v2: added references | Phys.Rev.D78:035005,2008 | 10.1103/PhysRevD.78.035005 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Taking the MSSM as an effective low-energy theory, with a cut-off scale of a
few TeV, can make significant modifications to the predictions concerning the
Higgs and stop sectors. We investigate the consequences of such a scenario for
electroweak baryogenesis. We find that the window for MSSM baryogenesis is
extended and, most important, can be made significantly more natural.
Specifically, it is possible to have one stop lighter than the top and the
other significantly lighter than TeV simultaneously with the Higgs mass above
the LEP bound. In addition, various aspects concerning CP violation are
affected. Most notably, it is possible to have dynamical phases in the bubble
walls at tree level, providing CP violating sources for Standard Model
fermions.
| [
{
"created": "Thu, 1 May 2008 13:51:51 GMT",
"version": "v1"
},
{
"created": "Tue, 20 May 2008 10:30:18 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Blum",
"Kfir",
""
],
[
"Nir",
"Yosef",
""
]
] | Taking the MSSM as an effective low-energy theory, with a cut-off scale of a few TeV, can make significant modifications to the predictions concerning the Higgs and stop sectors. We investigate the consequences of such a scenario for electroweak baryogenesis. We find that the window for MSSM baryogenesis is extended and, most important, can be made significantly more natural. Specifically, it is possible to have one stop lighter than the top and the other significantly lighter than TeV simultaneously with the Higgs mass above the LEP bound. In addition, various aspects concerning CP violation are affected. Most notably, it is possible to have dynamical phases in the bubble walls at tree level, providing CP violating sources for Standard Model fermions. |
2407.19997 | Ville Vaskonen | Francesco D'Eramo, Andrea Tesi, Ville Vaskonen | Irreducible cosmological backgrounds of a real scalar with a broken
symmetry | 15 pages, 4 figures | null | null | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We explore the irreducible cosmological implications of a singlet real scalar
field. Our focus is on theories with an approximate and spontaneously broken
$\mathbb{Z}_2$ symmetry where quasi-stable domain walls can form at early
times. This seemingly simple framework bears a wealth of phenomenological
implications that can be tackled by means of different cosmological and
astrophysical probes. We elucidate the connection between domain wall dynamics
and the production of dark matter and gravitational waves. In particular, we
identify three main benchmark scenarios. The gravitational wave signal observed
by pulsar timing arrays can be generated by the domain walls if the mass of the
singlet is $m_s \sim\,$PeV. For lower masses, but with $m_s \gtrsim 10\,$GeV,
scalars produced in the annihilation of the domain walls can be dark matter
with a distinctive feature in their power spectrum. Finally, the thermal bath
provides an unavoidable source of unstable scalars via the freeze-in mechanism
whose subsequent decays can be tested by their imprints on cosmological and
terrestrial observables.
| [
{
"created": "Mon, 29 Jul 2024 13:27:54 GMT",
"version": "v1"
}
] | 2024-07-30 | [
[
"D'Eramo",
"Francesco",
""
],
[
"Tesi",
"Andrea",
""
],
[
"Vaskonen",
"Ville",
""
]
] | We explore the irreducible cosmological implications of a singlet real scalar field. Our focus is on theories with an approximate and spontaneously broken $\mathbb{Z}_2$ symmetry where quasi-stable domain walls can form at early times. This seemingly simple framework bears a wealth of phenomenological implications that can be tackled by means of different cosmological and astrophysical probes. We elucidate the connection between domain wall dynamics and the production of dark matter and gravitational waves. In particular, we identify three main benchmark scenarios. The gravitational wave signal observed by pulsar timing arrays can be generated by the domain walls if the mass of the singlet is $m_s \sim\,$PeV. For lower masses, but with $m_s \gtrsim 10\,$GeV, scalars produced in the annihilation of the domain walls can be dark matter with a distinctive feature in their power spectrum. Finally, the thermal bath provides an unavoidable source of unstable scalars via the freeze-in mechanism whose subsequent decays can be tested by their imprints on cosmological and terrestrial observables. |
1401.4653 | Zhun Lu | Wenjuan Mao, Zhun Lu | On the beam spin asymmetries of electroproduction of charged hadrons off
the nucleon targets | 9 pages, 6 figures, version accepted by EPJC | null | 10.1140/epjc/s10052-014-2910-7 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the beam single-spin asymmetries $A_{LU}^{\sin\phi_h}$ for charged
hadrons produced in semi-inclusive deep inelastic scattering process, by
considering the $e H_1^\perp$ term and the $g^\perp D_1$ term simultaneously.
Besides the asymmetries for charged pions, for the first time we present the
analysis on the asymmetries in the production of charged kaons, protons and
antiprotons by longitudinally polarized leptons scattered off unpolarized
proton and deuteron targets. In our calculation we use two sets of transverse
momentum dependent distributions $g^\perp(x,\bm k_T^2)$ and $e(x,\bm k_T^2)$
calculated from two different spectator models, and compare the numerical
results with the preliminary data recently obtained by the HERMES
Collaboration. We also predict the beam spin asymmetries for $\pi^\pm$,
$K^\pm$, $p/\bar{p}$ electroproduction in semi-inclusive deep-inelastic
scattering of 12 GeV polarized electrons from unpolarized proton and deuteron
targets.
| [
{
"created": "Sun, 19 Jan 2014 10:53:42 GMT",
"version": "v1"
},
{
"created": "Fri, 31 Jan 2014 07:31:54 GMT",
"version": "v2"
},
{
"created": "Fri, 16 May 2014 02:07:01 GMT",
"version": "v3"
}
] | 2015-06-18 | [
[
"Mao",
"Wenjuan",
""
],
[
"Lu",
"Zhun",
""
]
] | We study the beam single-spin asymmetries $A_{LU}^{\sin\phi_h}$ for charged hadrons produced in semi-inclusive deep inelastic scattering process, by considering the $e H_1^\perp$ term and the $g^\perp D_1$ term simultaneously. Besides the asymmetries for charged pions, for the first time we present the analysis on the asymmetries in the production of charged kaons, protons and antiprotons by longitudinally polarized leptons scattered off unpolarized proton and deuteron targets. In our calculation we use two sets of transverse momentum dependent distributions $g^\perp(x,\bm k_T^2)$ and $e(x,\bm k_T^2)$ calculated from two different spectator models, and compare the numerical results with the preliminary data recently obtained by the HERMES Collaboration. We also predict the beam spin asymmetries for $\pi^\pm$, $K^\pm$, $p/\bar{p}$ electroproduction in semi-inclusive deep-inelastic scattering of 12 GeV polarized electrons from unpolarized proton and deuteron targets. |
hep-ph/9603382 | null | A. Nicolaidis and A. Taramopoulos (University of Thessaloniki, Greece) | Shadowing of Ultrahigh Energy Neutrinos | gziped, tar file of LaTeX paper plus 2 postscript figures, 13 pages | Phys.Lett. B386 (1996) 211-216 | 10.1016/0370-2693(96)00948-3 | THES-TP-96/04 | hep-ph astro-ph | null | The rise with energy of the neutrino--nucleon cross section implies that at
energies above few TeV the Earth is becoming opaque to cosmic neutrinos. The
neutrinos interact with the nucleons through the weak charged current,
resulting into absorption, and the weak neutral current, which provides a
redistribution of the neutrino energy. We Mellin transform the neutrino
transport equation and find its exact solution in the moment space. A simple
analytical formula is provided, which describes accurately the neutrino
spectrum, after the neutrinos have traversed the Earth. The effect of the weak
neutral current is most prominent for an initial flat neutrino spectrum and we
find that at low energies (around 1 TeV) the neutrino intensity is even
enhanced.
| [
{
"created": "Fri, 22 Mar 1996 14:12:01 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Nicolaidis",
"A.",
"",
"University of Thessaloniki, Greece"
],
[
"Taramopoulos",
"A.",
"",
"University of Thessaloniki, Greece"
]
] | The rise with energy of the neutrino--nucleon cross section implies that at energies above few TeV the Earth is becoming opaque to cosmic neutrinos. The neutrinos interact with the nucleons through the weak charged current, resulting into absorption, and the weak neutral current, which provides a redistribution of the neutrino energy. We Mellin transform the neutrino transport equation and find its exact solution in the moment space. A simple analytical formula is provided, which describes accurately the neutrino spectrum, after the neutrinos have traversed the Earth. The effect of the weak neutral current is most prominent for an initial flat neutrino spectrum and we find that at low energies (around 1 TeV) the neutrino intensity is even enhanced. |
1307.2206 | Zhentao Zhang | Zhentao Zhang | Multi-Sommerfeld enhancement in dark sector | 6 pages, 4 figures | Phys.Lett.B734:188-192,2014 | 10.1016/j.physletb.2014.05.054 | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the multi-Sommerfeld enhancement in the case where $V(r)$ is
composed of different kinds of potentials. We show that there are special
properties of the multi-Sommerfeld enhancement. The physical content of the
multi-Sommerfeld mechanism is carefully demonstrated. The multi-Sommerfeld
enhancement might play a role in dark matter annihilation.
| [
{
"created": "Mon, 8 Jul 2013 19:16:03 GMT",
"version": "v1"
},
{
"created": "Mon, 16 Sep 2013 17:31:47 GMT",
"version": "v2"
},
{
"created": "Tue, 26 Nov 2013 13:55:55 GMT",
"version": "v3"
}
] | 2014-06-04 | [
[
"Zhang",
"Zhentao",
""
]
] | We study the multi-Sommerfeld enhancement in the case where $V(r)$ is composed of different kinds of potentials. We show that there are special properties of the multi-Sommerfeld enhancement. The physical content of the multi-Sommerfeld mechanism is carefully demonstrated. The multi-Sommerfeld enhancement might play a role in dark matter annihilation. |
2106.00752 | Kiminad Mamo | Kiminad A. Mamo, Ismail Zahed | Electromagnetic radii of the nucleon in soft-wall holographic QCD | v2: significantly improved, 14 pages (with two columns), 4 figures, 2
tables, our conclusion has changed (we know have perfect agreement with the
PRad measurement of the charge radius of the proton, i.e., in the
original-minimal soft-wall holographic QCD, we have predicted the charge
radius of the proton to be $\bf{r_{p}=0.831\,\pm\,0.008\,\,\text{fm}}$.) | null | null | null | hep-ph hep-ex hep-th nucl-ex nucl-th | http://creativecommons.org/licenses/by/4.0/ | We revisit the electromagnetic form factors of the proton and neutron in the
original-minimal soft-wall holographic QCD, which has only two parameters,
i.e., the mass scale $\kappa$ and the twist parameter of the nucleon $\tau$. We
first fix $\tau=3$ by the hard scattering rule, and extract
$\kappa=0.402~\text{GeV}$ from the world data (including the Mainz A1 data) of
the Sachs magnetic form factor of the proton $G_M^p$. We then predict among
others, the charge radius of the proton to be
$\bf{r_{p}=0.831\,\pm\,0.008\,\,\text{fm}}$, in perfect agreement with the
recent charge radius of the proton measured by the PRad collaboration at
Jefferson Lab, and in agreement with the muonic hydrogen experiments. Our
prediction for the proton elastic form factor ratio $\mu_pG_E^p/G_M^p$ is also
in very good agreement with the recent high precision Jefferson Lab recoil
polarization experiment E08-007 for $Q^2=0.3\,-\,0.6~\text{GeV}^2$, and with
the recent high precision Mainz A1 experiment for $Q^2< 0.13~\text{GeV}^2$.
| [
{
"created": "Tue, 1 Jun 2021 19:55:20 GMT",
"version": "v1"
},
{
"created": "Wed, 14 Jul 2021 19:30:00 GMT",
"version": "v2"
},
{
"created": "Mon, 18 Apr 2022 19:56:39 GMT",
"version": "v3"
}
] | 2022-04-20 | [
[
"Mamo",
"Kiminad A.",
""
],
[
"Zahed",
"Ismail",
""
]
] | We revisit the electromagnetic form factors of the proton and neutron in the original-minimal soft-wall holographic QCD, which has only two parameters, i.e., the mass scale $\kappa$ and the twist parameter of the nucleon $\tau$. We first fix $\tau=3$ by the hard scattering rule, and extract $\kappa=0.402~\text{GeV}$ from the world data (including the Mainz A1 data) of the Sachs magnetic form factor of the proton $G_M^p$. We then predict among others, the charge radius of the proton to be $\bf{r_{p}=0.831\,\pm\,0.008\,\,\text{fm}}$, in perfect agreement with the recent charge radius of the proton measured by the PRad collaboration at Jefferson Lab, and in agreement with the muonic hydrogen experiments. Our prediction for the proton elastic form factor ratio $\mu_pG_E^p/G_M^p$ is also in very good agreement with the recent high precision Jefferson Lab recoil polarization experiment E08-007 for $Q^2=0.3\,-\,0.6~\text{GeV}^2$, and with the recent high precision Mainz A1 experiment for $Q^2< 0.13~\text{GeV}^2$. |
1311.2824 | Mariano Quiros | Mariano Quiros | Higgs Bosons in Extra Dimensions | 29 pages, 13 figures. Invited review for IJMPA | null | null | UAB-FT-744 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper, motivated by the recent discovery of a Higgs-like boson at the
LHC with a mass m_H\simeq 126 GeV, we review different models where the
hierarchy problem is solved by means of a warped extra dimension. In the
Randall-Sundrum model electroweak observables provide very strong bounds on the
mass of KK modes which motivates extensions to overcome this problem. Two
extensions are briefly discussed. One particular extension is based on the
deformation of the metric such that it strongly departs from the AdS_5
structure in the IR region while it goes asymptotically to AdS_5 in the UV
brane. This model has the IR brane close to a naked metric singularity (which
is outside the physical interval) characteristic of soft-walls constructions.
The proximity of the singularity provides a strong wave-function
renormalization for the Higgs field which suppresses the T and S parameters.
The second class of considered extensions are based on the introduction of an
extra gauge group in the bulk such that the custodial SU(2)_R symmetry is
gauged and protects the T parameter. By further enlarging the bulk gauge
symmetry one can find models where the Higgs is identified with the fifth
component of gauge fields and for which the Higgs potential, along with the
Higgs mass, can be dynamically determined by the Coleman-Weinberg mechanism.
| [
{
"created": "Tue, 12 Nov 2013 16:12:06 GMT",
"version": "v1"
}
] | 2013-11-18 | [
[
"Quiros",
"Mariano",
""
]
] | In this paper, motivated by the recent discovery of a Higgs-like boson at the LHC with a mass m_H\simeq 126 GeV, we review different models where the hierarchy problem is solved by means of a warped extra dimension. In the Randall-Sundrum model electroweak observables provide very strong bounds on the mass of KK modes which motivates extensions to overcome this problem. Two extensions are briefly discussed. One particular extension is based on the deformation of the metric such that it strongly departs from the AdS_5 structure in the IR region while it goes asymptotically to AdS_5 in the UV brane. This model has the IR brane close to a naked metric singularity (which is outside the physical interval) characteristic of soft-walls constructions. The proximity of the singularity provides a strong wave-function renormalization for the Higgs field which suppresses the T and S parameters. The second class of considered extensions are based on the introduction of an extra gauge group in the bulk such that the custodial SU(2)_R symmetry is gauged and protects the T parameter. By further enlarging the bulk gauge symmetry one can find models where the Higgs is identified with the fifth component of gauge fields and for which the Higgs potential, along with the Higgs mass, can be dynamically determined by the Coleman-Weinberg mechanism. |
1106.0610 | Denis Bernard | Denis Bernard | Comment on : A Proposal to Measure Photon-Photon Scattering | 1 page. v2 : corrected misprint in eq. numbering | null | null | null | hep-ph physics.optics quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | I comment on a recent preprint "A Proposal to Measure Photon-Photon
Scattering" that appeared recently as arXiv:1106.0465v1 [hep-ph].
| [
{
"created": "Fri, 3 Jun 2011 10:54:14 GMT",
"version": "v1"
},
{
"created": "Tue, 7 Jun 2011 07:28:49 GMT",
"version": "v2"
}
] | 2011-06-08 | [
[
"Bernard",
"Denis",
""
]
] | I comment on a recent preprint "A Proposal to Measure Photon-Photon Scattering" that appeared recently as arXiv:1106.0465v1 [hep-ph]. |
0805.3467 | Federico Alberto Ceccopieri | Federico A. Ceccopieri, Luca Trentadue (Parma U. & INFN, Parma) | NLO Semi-inclusive Drell-Yan cross-section in Quantum ChromoDynamics as
a Factorization Analyzer | 10 pages, 2 figures, typos corrected, references added. Submitted to
Phys.Lett.B | Phys.Lett.B668:319-323,2008 | 10.1016/j.physletb.2008.09.001 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We evaluate in perturbative QCD the semi-inclusive Drell-Yan cross-section
for the production of a single hadron accompaining the lepton pair. We
demonstrate to one loop level a collinear factorization formula within the
fracture functions approach. We propose such a process as a factorization
analyzer in hadronic collisions. Phenomenological implications at the hadron
colliders are briefly discussed.
| [
{
"created": "Thu, 22 May 2008 14:19:42 GMT",
"version": "v1"
},
{
"created": "Mon, 14 Jul 2008 08:14:42 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Ceccopieri",
"Federico A.",
"",
"Parma U. & INFN, Parma"
],
[
"Trentadue",
"Luca",
"",
"Parma U. & INFN, Parma"
]
] | We evaluate in perturbative QCD the semi-inclusive Drell-Yan cross-section for the production of a single hadron accompaining the lepton pair. We demonstrate to one loop level a collinear factorization formula within the fracture functions approach. We propose such a process as a factorization analyzer in hadronic collisions. Phenomenological implications at the hadron colliders are briefly discussed. |
0901.3997 | Boris A. Arbuzov | Boris A. Arbuzov | Bogoliubov compensation principle in the electro-weak interaction: value
of the gauge constant, muon g-2 anomaly, predictions for Tevatron and LHC | 14 pages, 9 figures, 2 tables, typos corrected | Eur.Phys.J.C61:51-59,2009 | 10.1140/epjc/s10052-009-0974-6 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We apply Bogoliubov compensation principle to the gauge electro-weak
interaction to demonstrate a spontaneous generation of anomalous three-boson
gauge invariant effective interaction. The non-trivial solution of compensation
equations uniquely defines values of parameters of the theory and the
form-factor of the anomalous interaction. The contribution of this interaction
to running EW coupling $\alpha_{ew}(p^2)$ gives its observable value
$\alpha_{ew}(M_W^2)=0.0374$ in satisfactory agreement to the experiment. The
anomalous three-boson interaction gives natural explanation of the well-known
discrepancy in muon $g-2$. The implications for EW studies at Tevatron and LHC
are briefly discussed.
| [
{
"created": "Mon, 26 Jan 2009 13:06:36 GMT",
"version": "v1"
},
{
"created": "Fri, 30 Jan 2009 10:34:27 GMT",
"version": "v2"
},
{
"created": "Tue, 10 Feb 2009 09:50:01 GMT",
"version": "v3"
}
] | 2009-07-22 | [
[
"Arbuzov",
"Boris A.",
""
]
] | We apply Bogoliubov compensation principle to the gauge electro-weak interaction to demonstrate a spontaneous generation of anomalous three-boson gauge invariant effective interaction. The non-trivial solution of compensation equations uniquely defines values of parameters of the theory and the form-factor of the anomalous interaction. The contribution of this interaction to running EW coupling $\alpha_{ew}(p^2)$ gives its observable value $\alpha_{ew}(M_W^2)=0.0374$ in satisfactory agreement to the experiment. The anomalous three-boson interaction gives natural explanation of the well-known discrepancy in muon $g-2$. The implications for EW studies at Tevatron and LHC are briefly discussed. |
hep-ph/9302271 | Daniel Ng | James T. Liu and Daniel Ng | $Z$--$Z'$ mixing and oblique corrections in an ${\rm SU(3) \times U(1)}$
model | IFP-460-UNC, TRI-PP-93-11, 20 pages, 2 figures are appended | Z.Phys.C62:693-700,1994 | 10.1007/BF01574173 | null | hep-ph | null | A global fit for experiments is included in this revised version.
| [
{
"created": "Wed, 17 Feb 1993 23:57:34 GMT",
"version": "v1"
},
{
"created": "Fri, 5 Mar 1993 00:52:21 GMT",
"version": "v2"
},
{
"created": "Wed, 30 Jun 1993 16:28:27 GMT",
"version": "v3"
}
] | 2014-11-17 | [
[
"Liu",
"James T.",
""
],
[
"Ng",
"Daniel",
""
]
] | A global fit for experiments is included in this revised version. |
0812.1051 | Cyrille Marquet | Guillaume Beuf, Cyrille Marquet and Bo-Wen Xiao | Heavy-quark energy loss and thermalization in a strongly coupled SYM
plasma | 14 pages, 1 figure | Phys.Rev.D80:085001,2009 | 10.1103/PhysRevD.80.085001 | null | hep-ph hep-th nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Using the AdS/CFT correspondence, we compute the radiative energy loss of a
slowly decelerating heavy quark with mass M moving through a supersymmetric
Yang Mills (SYM) plasma at temperature T at large t'Hooft coupling \lambda. The
calculation is carried out in terms of perturbation in \sqrt{\lambda}T/M, and
the rate of the energy loss is computed up to second order. We explain the
physical meaning of each correction and estimate the thermalization time of a
heavy quark moving in a strongly-coupled plasma.
| [
{
"created": "Thu, 4 Dec 2008 23:44:32 GMT",
"version": "v1"
}
] | 2014-11-18 | [
[
"Beuf",
"Guillaume",
""
],
[
"Marquet",
"Cyrille",
""
],
[
"Xiao",
"Bo-Wen",
""
]
] | Using the AdS/CFT correspondence, we compute the radiative energy loss of a slowly decelerating heavy quark with mass M moving through a supersymmetric Yang Mills (SYM) plasma at temperature T at large t'Hooft coupling \lambda. The calculation is carried out in terms of perturbation in \sqrt{\lambda}T/M, and the rate of the energy loss is computed up to second order. We explain the physical meaning of each correction and estimate the thermalization time of a heavy quark moving in a strongly-coupled plasma. |
2112.09210 | Craig Roberts | Z.-F. Cui, M. Ding, J. M. Morgado, K. Raya, D. Binosi, L. Chang, J.
Papavassiliou, C. D. Roberts, J. Rodr\'iguez-Quintero and S. M. Schmidt | Concerning pion parton distributions | 15 pages, 9 figures, 1 table | null | 10.1140/epja/s10050-021-00658-7 | NJU-INP 053/21 | hep-ph hep-ex hep-lat nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Analyses of the pion valence-quark distribution function (DF),
${u}^\pi(x;\zeta)$, which explicitly incorporate the behaviour of the pion wave
function prescribed by quantum chromodynamics (QCD), predict ${u}^\pi(x\simeq
1;\zeta) \sim (1-x)^{\beta(\zeta)}$, $\beta(\zeta \gtrsim m_p)>2$, where $m_p$
is the proton mass. Nevertheless, more than forty years after the first
experiment to collect data suitable for extracting the $x\simeq 1$ behaviour of
${u}^\pi$, the empirical status remains uncertain because some methods used to
fit existing data return a result for ${u}^\pi$ that violates this constraint.
Such disagreement entails one of the following conclusions: the analysis
concerned is incomplete; not all data being considered are a true expression of
qualities intrinsic to the pion; or QCD, as it is currently understood, is not
the theory of strong interactions. New, precise data are necessary before a
final conclusion is possible. In developing these positions, we exploit a
single proposition, viz. there is an effective charge which defines an
evolution scheme for parton DFs that is all-orders exact. This proposition has
numerous corollaries, which can be used to test the character of any DF,
whether fitted or calculated.
| [
{
"created": "Thu, 16 Dec 2021 21:39:14 GMT",
"version": "v1"
}
] | 2022-02-09 | [
[
"Cui",
"Z. -F.",
""
],
[
"Ding",
"M.",
""
],
[
"Morgado",
"J. M.",
""
],
[
"Raya",
"K.",
""
],
[
"Binosi",
"D.",
""
],
[
"Chang",
"L.",
""
],
[
"Papavassiliou",
"J.",
""
],
[
"Roberts",
"C. D.",... | Analyses of the pion valence-quark distribution function (DF), ${u}^\pi(x;\zeta)$, which explicitly incorporate the behaviour of the pion wave function prescribed by quantum chromodynamics (QCD), predict ${u}^\pi(x\simeq 1;\zeta) \sim (1-x)^{\beta(\zeta)}$, $\beta(\zeta \gtrsim m_p)>2$, where $m_p$ is the proton mass. Nevertheless, more than forty years after the first experiment to collect data suitable for extracting the $x\simeq 1$ behaviour of ${u}^\pi$, the empirical status remains uncertain because some methods used to fit existing data return a result for ${u}^\pi$ that violates this constraint. Such disagreement entails one of the following conclusions: the analysis concerned is incomplete; not all data being considered are a true expression of qualities intrinsic to the pion; or QCD, as it is currently understood, is not the theory of strong interactions. New, precise data are necessary before a final conclusion is possible. In developing these positions, we exploit a single proposition, viz. there is an effective charge which defines an evolution scheme for parton DFs that is all-orders exact. This proposition has numerous corollaries, which can be used to test the character of any DF, whether fitted or calculated. |
hep-ph/0202027 | Pietro Faccioli | P. Faccioli, A. Schwenk, E.V. Shuryak (SUNY Stony Brook) | Instanton Contribution to the Pion Electro-Magnetic Formfactor at Q^2 >
1 GeV^2 | 8 pages, 5 figures, minor revisions | Phys.Rev. D67 (2003) 113009 | 10.1103/PhysRevD.67.113009 | null | hep-ph nucl-th | null | We study the effects of instantons on the charged pion electro-magnetic
formfactor at intermediate momenta. In the Single Instanton Approximation
(SIA), we predict the pion formfactor in the kinematic region Q^2=2-15 GeV^2.
By developing the calculation in a mixed time-momentum representation, it is
possible to maximally reduce the model dependence and to calculate the
formfactor directly. We find the intriguing result that the SIA calculation
coincides with the vector dominance monopole form, up to surprisingly high
momentum transfer Q^2~10 GeV^2. This suggests that vector dominance for the
pion holds beyond low energy nuclear physics.
| [
{
"created": "Mon, 4 Feb 2002 17:13:02 GMT",
"version": "v1"
},
{
"created": "Thu, 17 Oct 2002 16:23:17 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Faccioli",
"P.",
"",
"SUNY Stony Brook"
],
[
"Schwenk",
"A.",
"",
"SUNY Stony Brook"
],
[
"Shuryak",
"E. V.",
"",
"SUNY Stony Brook"
]
] | We study the effects of instantons on the charged pion electro-magnetic formfactor at intermediate momenta. In the Single Instanton Approximation (SIA), we predict the pion formfactor in the kinematic region Q^2=2-15 GeV^2. By developing the calculation in a mixed time-momentum representation, it is possible to maximally reduce the model dependence and to calculate the formfactor directly. We find the intriguing result that the SIA calculation coincides with the vector dominance monopole form, up to surprisingly high momentum transfer Q^2~10 GeV^2. This suggests that vector dominance for the pion holds beyond low energy nuclear physics. |
hep-ph/9605463 | null | L. Clavelli and I. Terekhov | Inclusive Jet E_T Distributions and Light Gluinos | 10 pages (shortened), 1 EPS figure | Phys.Rev.Lett. 77 (1996) 1941-1944 | 10.1103/PhysRevLett.77.1941 | UAHEP966 | hep-ph | null | In the light gluino variant of the minimal supersymmetric model gluino pairs
can be readily produced in collider experiments even if the squarks are
arbitrarily heavy. This enhances the jet transverse energy distributions. In
addition the slower running of the strong coupling constant in the presence of
light gluinos leads to a further enhancement at higher transverse energies
relative to the standard $QCD$ expectations. Finally, the enhanced squark
gluino production would lead to a Jacobian peak in the $E_T$ distribution at
about $M_{\tilde Q}/2$. These effects are of about the right magnitude to
explain anomalies observed by the $CDF$ and $D0$ collaborations.
| [
{
"created": "Sat, 1 Jun 1996 00:28:04 GMT",
"version": "v1"
},
{
"created": "Wed, 5 Jun 1996 20:23:11 GMT",
"version": "v2"
}
] | 2009-10-28 | [
[
"Clavelli",
"L.",
""
],
[
"Terekhov",
"I.",
""
]
] | In the light gluino variant of the minimal supersymmetric model gluino pairs can be readily produced in collider experiments even if the squarks are arbitrarily heavy. This enhances the jet transverse energy distributions. In addition the slower running of the strong coupling constant in the presence of light gluinos leads to a further enhancement at higher transverse energies relative to the standard $QCD$ expectations. Finally, the enhanced squark gluino production would lead to a Jacobian peak in the $E_T$ distribution at about $M_{\tilde Q}/2$. These effects are of about the right magnitude to explain anomalies observed by the $CDF$ and $D0$ collaborations. |
hep-ph/0608228 | Tatsuru Kikuchi | Takeshi Fukuyama and Tatsuru Kikuchi | Axion and PVLAS data in a Little Higgs model | 7 pages, no figure; the version to appear in Phys. Rev. D | Phys.Rev.D74:115004,2006 | 10.1103/PhysRevD.74.115004 | null | hep-ph | null | Little Higgs models may provide a solution to the gauge hierarchy problem in
the mass of the Higgs boson. In this framework the Higgs boson is arisen as the
pseudo-Nambu-Goldstone (PNG) boson. We show that the lepton triplet introduced
in a little Higgs model explains a small mass parameter in the double see-saw
mechanism for neutrino masses, and it can also gives an explanation for the
axion like particle recently reported by PVLAS collaboration.
| [
{
"created": "Mon, 21 Aug 2006 07:48:42 GMT",
"version": "v1"
},
{
"created": "Sat, 26 Aug 2006 06:12:27 GMT",
"version": "v2"
},
{
"created": "Sat, 11 Nov 2006 11:58:21 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Fukuyama",
"Takeshi",
""
],
[
"Kikuchi",
"Tatsuru",
""
]
] | Little Higgs models may provide a solution to the gauge hierarchy problem in the mass of the Higgs boson. In this framework the Higgs boson is arisen as the pseudo-Nambu-Goldstone (PNG) boson. We show that the lepton triplet introduced in a little Higgs model explains a small mass parameter in the double see-saw mechanism for neutrino masses, and it can also gives an explanation for the axion like particle recently reported by PVLAS collaboration. |
2008.04918 | Giuseppe Lucente | Giuseppe Lucente (Bari Univ.), Pierluca Carenza (Bari Univ. and INFN
Bari), Tobias Fischer (Wroclaw Univ.), Maurizio Giannotti (Barry Univ.),
Alessandro Mirizzi (Bari Univ. and INFN Bari) | Heavy axion-like particles and core-collapse supernovae: constraints and
impact on the explosion mechanism | v2 (32 pages, 21 figure): revised version. Matches the published
version on JCAP. Major changes to improve the robustness of the bound. Added
two Appendices on the possible constraining criteria and on the effect of the
SN progenitor mass on the bound | JCAP12(2020)008 | 10.1088/1475-7516/2020/12/008 | null | hep-ph astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Heavy axion-like particles (ALPs), with masses $m_a \gtrsim 100$ keV, coupled
with photons, would be copiously produced in a supernova (SN) core via
Primakoff process and photon coalescence. Using a state-of-the-art SN model, we
revisit the energy-loss SN 1987A bounds on axion-photon coupling. Moreover, we
point out that heavy ALPs with masses $m_a \gtrsim 100$ MeV and axion-photon
coupling $g_{a\gamma} \gtrsim 4 \times 10^{-9}$ GeV$^{-1}$ would decay into
photons behind the shock-wave producing a possible enhancement in the energy
deposition that would boost the SN shock revival.
| [
{
"created": "Tue, 11 Aug 2020 18:00:02 GMT",
"version": "v1"
},
{
"created": "Fri, 4 Dec 2020 11:07:44 GMT",
"version": "v2"
}
] | 2020-12-07 | [
[
"Lucente",
"Giuseppe",
"",
"Bari Univ."
],
[
"Carenza",
"Pierluca",
"",
"Bari Univ. and INFN\n Bari"
],
[
"Fischer",
"Tobias",
"",
"Wroclaw Univ."
],
[
"Giannotti",
"Maurizio",
"",
"Barry Univ."
],
[
"Mirizzi",
"Alessandro",
... | Heavy axion-like particles (ALPs), with masses $m_a \gtrsim 100$ keV, coupled with photons, would be copiously produced in a supernova (SN) core via Primakoff process and photon coalescence. Using a state-of-the-art SN model, we revisit the energy-loss SN 1987A bounds on axion-photon coupling. Moreover, we point out that heavy ALPs with masses $m_a \gtrsim 100$ MeV and axion-photon coupling $g_{a\gamma} \gtrsim 4 \times 10^{-9}$ GeV$^{-1}$ would decay into photons behind the shock-wave producing a possible enhancement in the energy deposition that would boost the SN shock revival. |
hep-ph/0111039 | Hans-Christian Pauli | Michael Frewer (MPI Kernphysik, Heidelberg), Tobias Frederico (S.
Jos\'e dos Campos, SP, Brazil), and Hans-Christian Pauli (MPI Kernphysik,
Heidelberg) | Renormalization of an effective model Hamiltonian by a counter term | 3 pages, 3 figures, 1 reference. to be published in Nucl. Phys. B
(Proc. Suppl.) Talk presented at the Workshop "Light-cone Physics: Particles
and Strings" at ECT* in Trento, Sep 3-11, 2001 | Nucl.Phys.Proc.Suppl. 108 (2002) 239-241 | 10.1016/S0920-5632(02)01335-X | null | hep-ph | null | An ill-defined integral equation for modeling the mass-spectrum of mesons is
regulated with an additional but unphysical parameter. This parameter
dependance is removed by renormalization. Illustrative graphical examples are
given.
| [
{
"created": "Mon, 5 Nov 2001 12:00:46 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Frewer",
"Michael",
"",
"MPI Kernphysik, Heidelberg"
],
[
"Frederico",
"Tobias",
"",
"S.\n José dos Campos, SP, Brazil"
],
[
"Pauli",
"Hans-Christian",
"",
"MPI Kernphysik,\n Heidelberg"
]
] | An ill-defined integral equation for modeling the mass-spectrum of mesons is regulated with an additional but unphysical parameter. This parameter dependance is removed by renormalization. Illustrative graphical examples are given. |
hep-ph/9803238 | Claude Bourrely | C. Bourrely, E. Leader and O.V. Teryaev | Positivity of NLO Spin-Dependent Parton Distributions | 6 pages, LateX, 1 figure | null | null | CPT-97/P.3581 | hep-ph | null | We discuss the positivity of the hadron density matrix in QCD. This basic
property is shown to be preserved by QCD evolution, provided the relation
$|\Delta P_{ij}(z)| \leq P_{ij}$ is valid for all kernels for $z < 1$, and the
usual "+" prescription is used. We comment on the positivity restrictions for
the choice of the NLO factorization scheme for the evolution of the
spin-dependent parton distributions.
| [
{
"created": "Wed, 4 Mar 1998 10:33:02 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Bourrely",
"C.",
""
],
[
"Leader",
"E.",
""
],
[
"Teryaev",
"O. V.",
""
]
] | We discuss the positivity of the hadron density matrix in QCD. This basic property is shown to be preserved by QCD evolution, provided the relation $|\Delta P_{ij}(z)| \leq P_{ij}$ is valid for all kernels for $z < 1$, and the usual "+" prescription is used. We comment on the positivity restrictions for the choice of the NLO factorization scheme for the evolution of the spin-dependent parton distributions. |
hep-ph/9611387 | null | Markus A. Luty | Compositeness and Supersymmetry Breaking in the Observable Sector | 23 pages, LaTeX2e | null | null | UMD-PP-97-59 | hep-ph | null | We consider models for physics beyond the standard model in which
supersymmetry is broken spontaneously near the weak scale by fields that are
charged under electroweak symmetry. We show that this is possible if some or
all of the light quarks and leptons are composite near the weak scale.
Flavor-changing neutral currents can be naturally suppressed by a GIM mechanism
or by approximate flavor symmetries. CP and B violation may be suppressed by
accidental symmetries. We give a general effective field theory analysis of
such models, and argue that they can be phenomenologically acceptable and lead
to interesting observable signals in future experiments. We then construct
explicit models based on non-perturbative effects discovered by Seiberg.
| [
{
"created": "Thu, 21 Nov 1996 18:29:59 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Luty",
"Markus A.",
""
]
] | We consider models for physics beyond the standard model in which supersymmetry is broken spontaneously near the weak scale by fields that are charged under electroweak symmetry. We show that this is possible if some or all of the light quarks and leptons are composite near the weak scale. Flavor-changing neutral currents can be naturally suppressed by a GIM mechanism or by approximate flavor symmetries. CP and B violation may be suppressed by accidental symmetries. We give a general effective field theory analysis of such models, and argue that they can be phenomenologically acceptable and lead to interesting observable signals in future experiments. We then construct explicit models based on non-perturbative effects discovered by Seiberg. |
1805.05103 | George W.-S. Hou | George Wei-Shu Hou | Genuine Extra Yukawas from Extra Higgs, Implications | 4 pages, 2 figures, presented at Moriond QCD 2018 | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | With a second Higgs doublet, extra Yukawa couplings $\rho_{ij}$ generally
exist. Baryon Asymmetry of the Universe (BAU) can be accounted for by
$\rho_{tt} \sim {\cal O}(1)$, with first order electroweak phase transition
(EWPT) arising from ${\cal O}(1)$ Higgs quartic couplings. The latter can
explain why the observed $h(125)$ boson so resembles the Standard Model (SM)
Higgs: with coupling $\eta_6 \sim{\cal O}(1)$ for two-doublet mixing, the
$H$--$h$ mixing angle $\cos\gamma \cong -\eta_6 v^2/(m_H^2 - m_h^2)$ is
suppressed by the $CP$-even boson mass splitting $m_H^2 - m_h^2 > {\rm few}\
v^2$. The approximate alignment, together with the fermion mass-mixing pattern,
controls FCNC Higgs effects at low energy. The picture can be probed by $pp \to
tt\bar c$, $tt\bar t$, i.e. same-sign top and triple-top processes at the LHC.
| [
{
"created": "Mon, 14 May 2018 10:55:43 GMT",
"version": "v1"
}
] | 2018-05-15 | [
[
"Hou",
"George Wei-Shu",
""
]
] | With a second Higgs doublet, extra Yukawa couplings $\rho_{ij}$ generally exist. Baryon Asymmetry of the Universe (BAU) can be accounted for by $\rho_{tt} \sim {\cal O}(1)$, with first order electroweak phase transition (EWPT) arising from ${\cal O}(1)$ Higgs quartic couplings. The latter can explain why the observed $h(125)$ boson so resembles the Standard Model (SM) Higgs: with coupling $\eta_6 \sim{\cal O}(1)$ for two-doublet mixing, the $H$--$h$ mixing angle $\cos\gamma \cong -\eta_6 v^2/(m_H^2 - m_h^2)$ is suppressed by the $CP$-even boson mass splitting $m_H^2 - m_h^2 > {\rm few}\ v^2$. The approximate alignment, together with the fermion mass-mixing pattern, controls FCNC Higgs effects at low energy. The picture can be probed by $pp \to tt\bar c$, $tt\bar t$, i.e. same-sign top and triple-top processes at the LHC. |
hep-ph/9805435 | null | Stanislaw Mrowczynski | Topics in the Transport Theory of Quark-Gluon Plasma | 42 pages, no macros | Phys.Part.Nucl. 30 (1999) 419-435; Fiz.Elem.Chast.Atom.Yadra 30
(1999) 954-991 | 10.1134/1.953113 | null | hep-ph | null | A few topics of the transport theory of quark-gluon plasma are reviewed. A
derivation of the transport equations form the underlaying dynamical theory is
discussed within the $\phi^4$ model. Peculiarities of the kinetic equations of
quarks and gluons are considered and the plasma (linear) response to the color
field is studied. The chromoelectric tensor permeability is found and the
plasma oscillations are discussed. Finally, the filamentation instability in
the strongly anisotropic parton system from ultrarelativistic heavy-ion
collisions is discussed in detail.
| [
{
"created": "Sat, 23 May 1998 18:34:25 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Mrowczynski",
"Stanislaw",
""
]
] | A few topics of the transport theory of quark-gluon plasma are reviewed. A derivation of the transport equations form the underlaying dynamical theory is discussed within the $\phi^4$ model. Peculiarities of the kinetic equations of quarks and gluons are considered and the plasma (linear) response to the color field is studied. The chromoelectric tensor permeability is found and the plasma oscillations are discussed. Finally, the filamentation instability in the strongly anisotropic parton system from ultrarelativistic heavy-ion collisions is discussed in detail. |
1005.0797 | Jonathan Rosner | Timothy Hobbs and Jonathan L. Rosner | Electroweak Constraints from Atomic Parity Violation and Neutrino
Scattering | 10 pages, 4 figures, final corrected version to be published in
Physical Review D | Phys.Rev.D82:013001,2010 | 10.1103/PhysRevD.82.013001 | EFI 09-21 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Precision electroweak physics can provide fertile ground for uncovering new
physics beyond the Standard Model (SM). One area in which new physics can
appear is in so-called "oblique corrections", i.e., next-to-leading order
expansions of bosonic propagators corresponding to vacuum polarization. One may
parametrize their effects in terms of quantities $S$ and $T$ that discriminate
between conservation and non-conservation of isospin. This provides a means of
comparing the relative contributions of precision electroweak experiments to
constraints on new physics. Given the prevalence of strongly $T$-sensitive
experiments, there is an acute need for further constraints on $S$, such as
provided by atomic parity-violating experiments on heavy atoms. We evaluate
constraints on $S$ arising from recently improved calculations in the Cs atom.
We show that the top quark mass $m_t$ provides stringent constraints on $S$
within the context of the Standard Model. We also consider the potential
contributions of next-generation neutrino scattering experiments to improved
$(S,T)$ constraints.
| [
{
"created": "Wed, 5 May 2010 17:41:14 GMT",
"version": "v1"
},
{
"created": "Fri, 14 May 2010 01:03:21 GMT",
"version": "v2"
},
{
"created": "Tue, 25 May 2010 21:19:20 GMT",
"version": "v3"
},
{
"created": "Mon, 28 Jun 2010 22:32:38 GMT",
"version": "v4"
}
] | 2015-03-17 | [
[
"Hobbs",
"Timothy",
""
],
[
"Rosner",
"Jonathan L.",
""
]
] | Precision electroweak physics can provide fertile ground for uncovering new physics beyond the Standard Model (SM). One area in which new physics can appear is in so-called "oblique corrections", i.e., next-to-leading order expansions of bosonic propagators corresponding to vacuum polarization. One may parametrize their effects in terms of quantities $S$ and $T$ that discriminate between conservation and non-conservation of isospin. This provides a means of comparing the relative contributions of precision electroweak experiments to constraints on new physics. Given the prevalence of strongly $T$-sensitive experiments, there is an acute need for further constraints on $S$, such as provided by atomic parity-violating experiments on heavy atoms. We evaluate constraints on $S$ arising from recently improved calculations in the Cs atom. We show that the top quark mass $m_t$ provides stringent constraints on $S$ within the context of the Standard Model. We also consider the potential contributions of next-generation neutrino scattering experiments to improved $(S,T)$ constraints. |
1912.03695 | Kai Schmitz | Wilfried Buchmuller, Valerie Domcke, Hitoshi Murayama, Kai Schmitz | Probing the scale of grand unification with gravitational waves | 6 pages, 3 figures. v2: updated references, matches version published
in PLB | Phys. Lett. B 809 (2020) 135764 | 10.1016/j.physletb.2020.135764 | CERN-TH-2019-215, DESY 19-210, IPMU 19-0179 | hep-ph astro-ph.CO gr-qc | http://creativecommons.org/licenses/by/4.0/ | The spontaneous breaking of U(1)_B-L around the scale of grand unification
can simultaneously account for hybrid inflation, leptogenesis, and neutralino
dark matter, thus resolving three major puzzles of particle physics and
cosmology in a single predictive framework. The B-L phase transition also
results in a network of cosmic strings. If strong and electroweak interactions
are unified in an SO(10) gauge group, containing U(1)_B-L as a subgroup, these
strings are metastable. In this case, they produce a stochastic background of
gravitational waves that evades current pulsar timing bounds, but features a
flat spectrum with amplitude h^2\Omega_GW ~ 10^-8 at interferometer
frequencies. Ongoing and future LIGO observations will hence probe the scale of
B-L breaking.
| [
{
"created": "Sun, 8 Dec 2019 15:23:46 GMT",
"version": "v1"
},
{
"created": "Mon, 16 Nov 2020 21:12:28 GMT",
"version": "v2"
}
] | 2020-11-18 | [
[
"Buchmuller",
"Wilfried",
""
],
[
"Domcke",
"Valerie",
""
],
[
"Murayama",
"Hitoshi",
""
],
[
"Schmitz",
"Kai",
""
]
] | The spontaneous breaking of U(1)_B-L around the scale of grand unification can simultaneously account for hybrid inflation, leptogenesis, and neutralino dark matter, thus resolving three major puzzles of particle physics and cosmology in a single predictive framework. The B-L phase transition also results in a network of cosmic strings. If strong and electroweak interactions are unified in an SO(10) gauge group, containing U(1)_B-L as a subgroup, these strings are metastable. In this case, they produce a stochastic background of gravitational waves that evades current pulsar timing bounds, but features a flat spectrum with amplitude h^2\Omega_GW ~ 10^-8 at interferometer frequencies. Ongoing and future LIGO observations will hence probe the scale of B-L breaking. |
hep-ph/9504406 | Ben Allanach | B.C.Allanach, S.F.King (Southampton) | Quadruple Yukawa Unification in the Minimal Supersymmetric Model | 10 pages plain LaTex, uuencoded .epsf files in part 2. Revised
version has NO changes to content, merely changed format to .tex file | Phys.Lett. B353 (1995) 477-482 | 10.1016/0370-2693(95)00605-K | SHEP-95-16 | hep-ph | null | Predictions for m_t, tan beta, m_nu_tau are calculated for quadruple third
family t-b-tau-nu_tau Yukawa unified models in the MSSM. The renormalisation
group equations for the 3 families of the MSSM, including the right handed
neutrino, are presented. For right handed tau neutrino Majorana masses that are
bigger than 10^11 GeV, the tau neutrino mass is consistent with present
cosmological bounds. The m_t, tan beta predictions are approximately equivalent
to those in triple third family Yukawa unified models.
| [
{
"created": "Thu, 27 Apr 1995 11:38:38 GMT",
"version": "v1"
},
{
"created": "Fri, 19 May 1995 10:49:26 GMT",
"version": "v2"
}
] | 2009-10-28 | [
[
"Allanach",
"B. C.",
"",
"Southampton"
],
[
"King",
"S. F.",
"",
"Southampton"
]
] | Predictions for m_t, tan beta, m_nu_tau are calculated for quadruple third family t-b-tau-nu_tau Yukawa unified models in the MSSM. The renormalisation group equations for the 3 families of the MSSM, including the right handed neutrino, are presented. For right handed tau neutrino Majorana masses that are bigger than 10^11 GeV, the tau neutrino mass is consistent with present cosmological bounds. The m_t, tan beta predictions are approximately equivalent to those in triple third family Yukawa unified models. |
hep-ph/0407093 | Hideo Suganuma | H. Suganuma (Tokyo Inst. Tech.), N. Ishii (Wako, RIKEN), H. Matsufuru
(Kyoto U., FIHS), Y. Nemoto (Brookhaven), T.T. Takahashi (Osaka U., Res. Ctr.
Nucl. Phys.) | Possible Hadronic Molecule Lambda(1405) and Thermal Glueballs in SU(3)
Lattice QCD | Talk given at 4th Catania Relativistic Ion Studies: Exotic Clustering
(CRIS 2002), Catania, Italy, 10-14 Jun 2002 | AIP Conf.Proc.644:366-371,2003 | 10.1063/1.1523211 | null | hep-ph | null | We aim to construct quark hadron physics based on QCD. First, using lattice
QCD, we study mass spectra of positive-parity and negative-parity baryons in
the octet, the decuplet and the singlet representations of the SU(3) flavor. In
particular, we consider the lightest negative-parity baryon, the
$\Lambda$(1405), which can be an exotic hadron as the $N \bar K$ molecular
state or the flavor-singlet three-quark state. We investigate the
negative-parity flavor-singlet three-quark state in lattice QCD using the
quenched approximation, where the dynamical quark-anitiquark pair creation is
absent and no mixing occurs between the three-quark and the five-quark states.
Our lattice QCD analysis suggests that the flavor-singlet three-quark state is
so heavy that the $\Lambda$(1405) cannot be identified as the three-quark
state, which supports the possibility of the molecular-state picture of the
$\Lambda$(1405). Second, we study thermal properties of the scalar glueball in
an anisotropic lattice QCD, and find about 300 MeV mass reduction near the QCD
critical temperature from the pole-mass analysis. Finally, we study the
three-quark potential, which is responsible to the baryon properties. The
detailed lattice QCD analysis for the 3Q potential indicates the Y-type
flux-tube formation linking the three quarks.
| [
{
"created": "Thu, 8 Jul 2004 06:13:23 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Suganuma",
"H.",
"",
"Tokyo Inst. Tech."
],
[
"Ishii",
"N.",
"",
"Wako, RIKEN"
],
[
"Matsufuru",
"H.",
"",
"Kyoto U., FIHS"
],
[
"Nemoto",
"Y.",
"",
"Brookhaven"
],
[
"Takahashi",
"T. T.",
"",
"Osaka U., Res. Ctr.\n ... | We aim to construct quark hadron physics based on QCD. First, using lattice QCD, we study mass spectra of positive-parity and negative-parity baryons in the octet, the decuplet and the singlet representations of the SU(3) flavor. In particular, we consider the lightest negative-parity baryon, the $\Lambda$(1405), which can be an exotic hadron as the $N \bar K$ molecular state or the flavor-singlet three-quark state. We investigate the negative-parity flavor-singlet three-quark state in lattice QCD using the quenched approximation, where the dynamical quark-anitiquark pair creation is absent and no mixing occurs between the three-quark and the five-quark states. Our lattice QCD analysis suggests that the flavor-singlet three-quark state is so heavy that the $\Lambda$(1405) cannot be identified as the three-quark state, which supports the possibility of the molecular-state picture of the $\Lambda$(1405). Second, we study thermal properties of the scalar glueball in an anisotropic lattice QCD, and find about 300 MeV mass reduction near the QCD critical temperature from the pole-mass analysis. Finally, we study the three-quark potential, which is responsible to the baryon properties. The detailed lattice QCD analysis for the 3Q potential indicates the Y-type flux-tube formation linking the three quarks. |
2002.09675 | Alessio Mangoni | Alessio Mangoni | Hadronic decays of the $J/\psi$ meson | null | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this work we propose mainly phenomenological and theoretical models that
allow, together with the use of the available experimental data, the
calculation of form factors (FFs) and decay amplitudes. We focus our attention
firstly on the $J/\psi$ decay into a pair of pions, showing that this process
does not proceed only electromagnetically as believed so far, due to the
presence of a non-negligible mixed strong-EM contribution to the total
branching ratio. Moreover we consider the decay of the $J/\psi$ meson into a
pair of baryon-antibaryon, where we separate, for the first time, the single
strong, electromagnetic and strong-EM contributions to the total BR and the
relative Feynman amplitudes, obtaining also the relative phase between the
strong and the electromagnetic ones.
| [
{
"created": "Sat, 22 Feb 2020 10:15:14 GMT",
"version": "v1"
}
] | 2020-02-25 | [
[
"Mangoni",
"Alessio",
""
]
] | In this work we propose mainly phenomenological and theoretical models that allow, together with the use of the available experimental data, the calculation of form factors (FFs) and decay amplitudes. We focus our attention firstly on the $J/\psi$ decay into a pair of pions, showing that this process does not proceed only electromagnetically as believed so far, due to the presence of a non-negligible mixed strong-EM contribution to the total branching ratio. Moreover we consider the decay of the $J/\psi$ meson into a pair of baryon-antibaryon, where we separate, for the first time, the single strong, electromagnetic and strong-EM contributions to the total BR and the relative Feynman amplitudes, obtaining also the relative phase between the strong and the electromagnetic ones. |
1505.04702 | Jiaming Zheng | O. Buchmueller, M. Citron, J. Ellis, S. Guha, J. Marrouche, K. A.
Olive, K. de Vries and Jiaming Zheng | Collider Interplay for Supersymmetry, Higgs and Dark Matter | 47 pages, 26 figures | Eur.Phys.J. C75 (2015) no.10, 469 | 10.1140/epjc/s10052-015-3675-3 | KCL-PH-TH/2015-21, LCTS/2015-12, CERN-PH-TH/2015-117,
UMN-TH-3437/15, FTPI-MINN-15/25 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss the potential impacts on the CMSSM of future LHC runs and possible
electron-positron and higher-energy proton-proton colliders, considering
searches for supersymmetry via MET events, precision electroweak physics, Higgs
measurements and dark matter searches. We validate and present estimates of the
physics reach for exclusion or discovery of supersymmetry via MET searches at
the LHC, which should cover the low-mass regions of the CMSSM parameter space
favoured in a recent global analysis. As we illustrate with a low-mass
benchmark point, a discovery would make possible accurate LHC measurements of
sparticle masses using the MT2 variable, which could be combined with
cross-section and other measurements to constrain the gluino, squark and stop
masses and hence the soft supersymmetry-breaking parameters m_0, m_{1/2} and
A_0 of the CMSSM. Slepton measurements at CLIC would enable m_0 and m_{1/2} to
be determined with high precision. If supersymmetry is indeed discovered in the
low-mass region, precision electroweak and Higgs measurements with a future
circular electron-positron collider (FCC-ee, also known as TLEP) combined with
LHC measurements would provide tests of the CMSSM at the loop level. If
supersymmetry is not discovered at the LHC, is likely to lie somewhere along a
focus-point, stop coannihilation strip or direct-channel A/H resonance funnel.
We discuss the prospects for discovering supersymmetry along these strips at a
future circular proton-proton collider such as FCC-hh. Illustrative benchmark
points on these strips indicate that also in this case FCC-ee could provide
tests of the CMSSM at the loop level.
| [
{
"created": "Mon, 18 May 2015 16:13:09 GMT",
"version": "v1"
},
{
"created": "Fri, 1 Apr 2016 21:23:28 GMT",
"version": "v2"
}
] | 2016-04-05 | [
[
"Buchmueller",
"O.",
""
],
[
"Citron",
"M.",
""
],
[
"Ellis",
"J.",
""
],
[
"Guha",
"S.",
""
],
[
"Marrouche",
"J.",
""
],
[
"Olive",
"K. A.",
""
],
[
"de Vries",
"K.",
""
],
[
"Zheng",
"Jiaming... | We discuss the potential impacts on the CMSSM of future LHC runs and possible electron-positron and higher-energy proton-proton colliders, considering searches for supersymmetry via MET events, precision electroweak physics, Higgs measurements and dark matter searches. We validate and present estimates of the physics reach for exclusion or discovery of supersymmetry via MET searches at the LHC, which should cover the low-mass regions of the CMSSM parameter space favoured in a recent global analysis. As we illustrate with a low-mass benchmark point, a discovery would make possible accurate LHC measurements of sparticle masses using the MT2 variable, which could be combined with cross-section and other measurements to constrain the gluino, squark and stop masses and hence the soft supersymmetry-breaking parameters m_0, m_{1/2} and A_0 of the CMSSM. Slepton measurements at CLIC would enable m_0 and m_{1/2} to be determined with high precision. If supersymmetry is indeed discovered in the low-mass region, precision electroweak and Higgs measurements with a future circular electron-positron collider (FCC-ee, also known as TLEP) combined with LHC measurements would provide tests of the CMSSM at the loop level. If supersymmetry is not discovered at the LHC, is likely to lie somewhere along a focus-point, stop coannihilation strip or direct-channel A/H resonance funnel. We discuss the prospects for discovering supersymmetry along these strips at a future circular proton-proton collider such as FCC-hh. Illustrative benchmark points on these strips indicate that also in this case FCC-ee could provide tests of the CMSSM at the loop level. |
hep-ph/0602217 | Dmitri Melikhov | W. Lucha and D. Melikhov | Quark-hadron duality and hadron properties from correlators of
pseudoscalar and axial currents | 11 pages | Phys.Rev. D73 (2006) 054009 | 10.1103/PhysRevD.73.054009 | HEPHY-PUB 815/06 | hep-ph | null | We study the operator product expansion (OPE) and quark-hadron duality for 2-
and 3-point correlators of the axial (A) and pseudoscalar (P) currents of the
light quarks. In the chiral limit these correlators are often dominated by
nonperturbative power corrections leading to subtleties of quark-hadron duality
relations and of the extraction of properties of light pseudoscalars. For the
2-point correlators, we show the sum rule for $<PP>$ to be sensitive to the
excited light pseudoscalar. For the 3-point correlators, we derive the Ward
identites which provide the normalization of the pion electromagnetic form
factor at zero momentum transfer. For large momentum transfer, we demonstrate
the way the correct behaviour of the pion form factor in agreement with
perturbative QCD emerges from condensate terms in the OPE for the $<PVP>$ and
$<AVP>$ correlators. The local-duality sum rule for $<AVA>$ is shown to lead to
the pion form factor with the required properties for all values of the
momentum transfer.
| [
{
"created": "Thu, 23 Feb 2006 14:43:44 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Lucha",
"W.",
""
],
[
"Melikhov",
"D.",
""
]
] | We study the operator product expansion (OPE) and quark-hadron duality for 2- and 3-point correlators of the axial (A) and pseudoscalar (P) currents of the light quarks. In the chiral limit these correlators are often dominated by nonperturbative power corrections leading to subtleties of quark-hadron duality relations and of the extraction of properties of light pseudoscalars. For the 2-point correlators, we show the sum rule for $<PP>$ to be sensitive to the excited light pseudoscalar. For the 3-point correlators, we derive the Ward identites which provide the normalization of the pion electromagnetic form factor at zero momentum transfer. For large momentum transfer, we demonstrate the way the correct behaviour of the pion form factor in agreement with perturbative QCD emerges from condensate terms in the OPE for the $<PVP>$ and $<AVP>$ correlators. The local-duality sum rule for $<AVA>$ is shown to lead to the pion form factor with the required properties for all values of the momentum transfer. |
1507.04354 | Michihisa Takeuchi | Cheng-Wei Chiang, Hajime Fukuda, Michihisa Takeuchi and Tsutomu T.
Yanagida | Flavor-Changing Neutral-Current Decays in Top-Specific Variant Axion
Model | 19 pages, 4 figures | null | null | IPMU 15-0111 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The invisible variant axion model is very attractive as it is free from the
domain wall problem. This model requires two Higgs doublets at the electroweak
scale where one Higgs doublet carries a nonzero Peccei-Quinn (PQ) charge and
the other is neutral under the PQ $\text U(1)$ symmetry. We consider the most
interesting and less constrained scenario of the variant axion model, where
only the right-handed top quark is charged under the PQ symmetry and couples
with the PQ-charged Higgs doublet. As a result, the top quark can decay to the
observed standard-model-like Higgs boson $h$ and the charm or up quark, $t\to
h~ c/u$, which is testable soon at the LHC Run-II. Moreover, we propose a
method to probe the chiral nature of the Higgs flavor-changing interaction
using the angular distribution of $t \to ch$ decays if a sufficient number of
such events are observed. We also show that our model has the capacity to
explain the $h\to\tau\mu$ decay reported by the CMS Collaboration, if the
right-handed tau lepton also carries a PQ charge and couples to the PQ-charged
Higgs boson.
| [
{
"created": "Wed, 15 Jul 2015 20:00:50 GMT",
"version": "v1"
}
] | 2015-07-17 | [
[
"Chiang",
"Cheng-Wei",
""
],
[
"Fukuda",
"Hajime",
""
],
[
"Takeuchi",
"Michihisa",
""
],
[
"Yanagida",
"Tsutomu T.",
""
]
] | The invisible variant axion model is very attractive as it is free from the domain wall problem. This model requires two Higgs doublets at the electroweak scale where one Higgs doublet carries a nonzero Peccei-Quinn (PQ) charge and the other is neutral under the PQ $\text U(1)$ symmetry. We consider the most interesting and less constrained scenario of the variant axion model, where only the right-handed top quark is charged under the PQ symmetry and couples with the PQ-charged Higgs doublet. As a result, the top quark can decay to the observed standard-model-like Higgs boson $h$ and the charm or up quark, $t\to h~ c/u$, which is testable soon at the LHC Run-II. Moreover, we propose a method to probe the chiral nature of the Higgs flavor-changing interaction using the angular distribution of $t \to ch$ decays if a sufficient number of such events are observed. We also show that our model has the capacity to explain the $h\to\tau\mu$ decay reported by the CMS Collaboration, if the right-handed tau lepton also carries a PQ charge and couples to the PQ-charged Higgs boson. |
hep-ph/0103041 | Feng Tai-fu | Tai-Fu Feng, Xue-Qian Li and Guo-Li Wang | Effective Lagrangian for $\bar{s}bg$ and $\bar{s}b\gamma$ Vertices in
the mSUGRA model | 12 pages + 7 ps figures, Latex | Phys.Rev. D65 (2002) 055007 | 10.1103/PhysRevD.65.055007 | null | hep-ph | null | Complete expressions of the $\bar{s}bg$ and $\bar{s}b\gamma$ vertices are
derived in the framework of supersymmetry with minimal flavor violation. With
the minimal supergravity (mSUGRA) model, a numerical analysis of the
supersymmetric contributions to the Wilson Coefficients at the weak scale is
presented.
| [
{
"created": "Sun, 4 Mar 2001 03:49:56 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Feng",
"Tai-Fu",
""
],
[
"Li",
"Xue-Qian",
""
],
[
"Wang",
"Guo-Li",
""
]
] | Complete expressions of the $\bar{s}bg$ and $\bar{s}b\gamma$ vertices are derived in the framework of supersymmetry with minimal flavor violation. With the minimal supergravity (mSUGRA) model, a numerical analysis of the supersymmetric contributions to the Wilson Coefficients at the weak scale is presented. |
1101.2323 | Muhammad Jamil Aslam | M. Ali Paracha, Ishtiaq Ahmed, M. Jamil Aslam | Semileptonic charmed $B$ meson decays in Universal Extra Dimension Model | 17 pages, 4 figures | Phys.Rev.D84:035003,2011 | 10.1103/PhysRevD.84.035003 | null | hep-ph | http://creativecommons.org/licenses/by/3.0/ | Form factors parameterizing the semileptonic decay $B_{c}\rightarrow
D_{s}^{\ast}l^{+}l^{-}$ ($l=\mu ,\tau $) are calculated using the frame work of
Ward Identities. These form factors are then used to calculate the physical
observables like branching ratio and helicity fractions of final state
$D_{s}^{\ast}$ meson in these decay modes. The analysis is then extended to the
the universal extra dimension (UED) model where the dependence of above
mentioned physical variables to the compactification radius R, the only unknown
parameter in UED model, is studied. It is shown that the helicity fractions of
$D_{s}^{\ast}$ are quite sensitive to the UED model especially when have muons
as the final state lepton. Therefore, these can serve as a useful tool to
establish new physics predicted by the UED model.
| [
{
"created": "Wed, 12 Jan 2011 11:04:36 GMT",
"version": "v1"
}
] | 2015-03-17 | [
[
"Paracha",
"M. Ali",
""
],
[
"Ahmed",
"Ishtiaq",
""
],
[
"Aslam",
"M. Jamil",
""
]
] | Form factors parameterizing the semileptonic decay $B_{c}\rightarrow D_{s}^{\ast}l^{+}l^{-}$ ($l=\mu ,\tau $) are calculated using the frame work of Ward Identities. These form factors are then used to calculate the physical observables like branching ratio and helicity fractions of final state $D_{s}^{\ast}$ meson in these decay modes. The analysis is then extended to the the universal extra dimension (UED) model where the dependence of above mentioned physical variables to the compactification radius R, the only unknown parameter in UED model, is studied. It is shown that the helicity fractions of $D_{s}^{\ast}$ are quite sensitive to the UED model especially when have muons as the final state lepton. Therefore, these can serve as a useful tool to establish new physics predicted by the UED model. |
1705.04859 | Ronald Kleiss | Ronald Kleiss and Oscar Boher Luna | Amplitudes, recursion relations and unitarity in the Abelian Higgs Model | 15 pages | null | 10.1007/JHEP12(2017)002 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The Abelian Higgs model forms an essential part of the electroweak standard
model: it is the sector containing only Z and Higgs bosons. We present a
diagram-based proof of the tree-level unitarity of this model inside the
unitary gauge, where only physical degrees of freedom occur. We derive
combinatorial recursion relations for off-shell amplitudes in the massless
approximation, which allows us to prove the cancellation of the first two
orders in energy of unitarity-violating high-energy behaviour for any
tree-level amplitude in this model. We describe a deformation of the amplitudes
by extending the physical phase space to at least 7 spacetime dimensions, which
leads to on-shell recursion relations a la BCFW. These lead to a simple proof
that all on-shell tree amplitudes obey partial-wave unitarity.
| [
{
"created": "Sat, 13 May 2017 17:17:28 GMT",
"version": "v1"
},
{
"created": "Mon, 5 Jun 2017 09:30:47 GMT",
"version": "v2"
},
{
"created": "Thu, 26 Oct 2017 18:39:11 GMT",
"version": "v3"
}
] | 2018-01-17 | [
[
"Kleiss",
"Ronald",
""
],
[
"Luna",
"Oscar Boher",
""
]
] | The Abelian Higgs model forms an essential part of the electroweak standard model: it is the sector containing only Z and Higgs bosons. We present a diagram-based proof of the tree-level unitarity of this model inside the unitary gauge, where only physical degrees of freedom occur. We derive combinatorial recursion relations for off-shell amplitudes in the massless approximation, which allows us to prove the cancellation of the first two orders in energy of unitarity-violating high-energy behaviour for any tree-level amplitude in this model. We describe a deformation of the amplitudes by extending the physical phase space to at least 7 spacetime dimensions, which leads to on-shell recursion relations a la BCFW. These lead to a simple proof that all on-shell tree amplitudes obey partial-wave unitarity. |
hep-ph/0512351 | Martin Beneke | M. Beneke and S. Jager (RWTH Aachen) | Spectator scattering at NLO in non-leptonic B decays: Tree amplitudes | 28 pages, 5 figures, LaTeX | Nucl.Phys.B751:160-185,2006 | 10.1016/j.nuclphysb.2006.06.010 | PITHA 05/21 | hep-ph | null | We compute the 1-loop (alpha_s^2) correction to hard spectator scattering in
non-leptonic B decay tree amplitudes. This forms part of the NNLO contribution
to the QCD factorization formula for hadronic B decays, and introduces a new
rescattering phase that corrects the leading-order result for direct CP
asymmetries. Among the technical issues, we discuss the cancellation of
infrared divergences, and the treatment of evanescent four-quark operators. The
infrared finiteness of our result establishes factorization of spectator
scattering at the 1-loop order. Depending on the values of hadronic input
parameters, the new 1-loop correction may have a significant impact on
tree-dominated decays such as B -> pi pi.
| [
{
"created": "Wed, 28 Dec 2005 10:50:45 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Beneke",
"M.",
"",
"RWTH Aachen"
],
[
"Jager",
"S.",
"",
"RWTH Aachen"
]
] | We compute the 1-loop (alpha_s^2) correction to hard spectator scattering in non-leptonic B decay tree amplitudes. This forms part of the NNLO contribution to the QCD factorization formula for hadronic B decays, and introduces a new rescattering phase that corrects the leading-order result for direct CP asymmetries. Among the technical issues, we discuss the cancellation of infrared divergences, and the treatment of evanescent four-quark operators. The infrared finiteness of our result establishes factorization of spectator scattering at the 1-loop order. Depending on the values of hadronic input parameters, the new 1-loop correction may have a significant impact on tree-dominated decays such as B -> pi pi. |
1207.1348 | Marco Battaglia | Alexandre Arbey, Marco Battaglia, Abdelhak Djouadi and Farvah Mahmoudi | The Higgs sector of the phenomenological MSSM in the light of the Higgs
boson discovery | 21 pages, 9 figures v2 - Discussion of the impact of LHC data
extended, scan statistics increased, a few figures added and typos corrected | JHEP 1209 (2012) 107 | 10.1007/JHEP09(2012)107 | CERN-PH-TH/2012-185 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The long awaited discovery of a new light scalar at the LHC opens up a new
era of studies of the Higgs sector in the SM and its extensions. In this paper
we discuss the consequences of the observation of a light Higgs boson with the
mass and rates reported by the ATLAS and CMS collaborations on the parameter
space of the phenomenological MSSM, including also the so far unsuccessful LHC
searches for the heavier Higgs bosons and supersymmetric particle partners in
missing transverse momentum as well as the constraints from B physics and dark
matter. We explore the various regimes of the MSSM Higgs sector depending on
the parameters MA and tan beta and show that only two of them are still allowed
by all present experimental constraints: the decoupling regime where there is
only one light and standard--like Higgs boson and the supersymmetric regime in
which there are light supersymmetric particle partners affecting the decay
properties of the Higgs boson, in particular its di-photon and invisible
decays.
| [
{
"created": "Thu, 5 Jul 2012 19:58:30 GMT",
"version": "v1"
},
{
"created": "Fri, 13 Jul 2012 18:19:54 GMT",
"version": "v2"
}
] | 2012-10-02 | [
[
"Arbey",
"Alexandre",
""
],
[
"Battaglia",
"Marco",
""
],
[
"Djouadi",
"Abdelhak",
""
],
[
"Mahmoudi",
"Farvah",
""
]
] | The long awaited discovery of a new light scalar at the LHC opens up a new era of studies of the Higgs sector in the SM and its extensions. In this paper we discuss the consequences of the observation of a light Higgs boson with the mass and rates reported by the ATLAS and CMS collaborations on the parameter space of the phenomenological MSSM, including also the so far unsuccessful LHC searches for the heavier Higgs bosons and supersymmetric particle partners in missing transverse momentum as well as the constraints from B physics and dark matter. We explore the various regimes of the MSSM Higgs sector depending on the parameters MA and tan beta and show that only two of them are still allowed by all present experimental constraints: the decoupling regime where there is only one light and standard--like Higgs boson and the supersymmetric regime in which there are light supersymmetric particle partners affecting the decay properties of the Higgs boson, in particular its di-photon and invisible decays. |
2308.13426 | Cristian Sierra C.F.Sierra | Peter Athron, R. Martinez and Cristian Sierra | $B$ meson anomalies and large $B^{+}\to K^{+}\nu\bar{\nu}$ in
non-universal $U(1)^\prime$ models | 16 pages, 5 figures, 2 tables, charged lepton flavour violating
constraints added, new citations included | null | 10.1007/JHEP02(2024)121 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | In view of both the latest LHCb measurement of $R_{K^{(*)}}$ and the new
$2.8\sigma$ deviation reported by Belle II on $B^{+}\to K^{+}\nu\bar{\nu}$
decays, we present a fit to the $B$ meson anomalies for various one and two
dimensional hypothesis including complex Wilson coefficients. We show in a
model-independent way that the generic non-universal $U(1)^{\prime}$ extensions
of the SM, without flavour violation, fail to simultaneously fit those
observables and corroborate that they can modify $\mathrm{BR}(B^{+}\to
K^{+}\nu\bar{\nu})$ up to only a $10\%$. In view of this deficit, we propose a
new way in which those models can accommodate the data at tree level by
introducing lepton flavour violating couplings and non-diagonal elements of the
charged lepton mixing matrix, with implications in future charged lepton
flavour violation searches.
| [
{
"created": "Fri, 25 Aug 2023 15:09:50 GMT",
"version": "v1"
},
{
"created": "Wed, 6 Sep 2023 03:29:10 GMT",
"version": "v2"
}
] | 2024-02-19 | [
[
"Athron",
"Peter",
""
],
[
"Martinez",
"R.",
""
],
[
"Sierra",
"Cristian",
""
]
] | In view of both the latest LHCb measurement of $R_{K^{(*)}}$ and the new $2.8\sigma$ deviation reported by Belle II on $B^{+}\to K^{+}\nu\bar{\nu}$ decays, we present a fit to the $B$ meson anomalies for various one and two dimensional hypothesis including complex Wilson coefficients. We show in a model-independent way that the generic non-universal $U(1)^{\prime}$ extensions of the SM, without flavour violation, fail to simultaneously fit those observables and corroborate that they can modify $\mathrm{BR}(B^{+}\to K^{+}\nu\bar{\nu})$ up to only a $10\%$. In view of this deficit, we propose a new way in which those models can accommodate the data at tree level by introducing lepton flavour violating couplings and non-diagonal elements of the charged lepton mixing matrix, with implications in future charged lepton flavour violation searches. |
0708.0268 | Simonetta Liuti | Saeed Ahmad, Heli Honkanen, Simonetta Liuti and Swadhin K. Taneja | Generalized Parton Distributions from Hadronic Observables: Non-Zero
Skewness | 29 pages, 8 figures; added references, changed text in several places | Eur.Phys.J.C63:407-421,2009 | 10.1140/epjc/s10052-009-1073-4 | null | hep-ph | null | We propose a physically motivated parametrization for the unpolarized
generalized parton distributions, H and E, valid at both zero and non-zero
values of the skewness variable, \zeta. Our approach follows a previous
detailed study of the \zeta=0 case where H and E were determined using
constraints from simultaneous fits of the experimental data on both the nucleon
elastic form factors and the deep inelastic structure functions in the non
singlet sector. Additional constraints at \zeta \neq 0 are provided by lattice
calculations of the higher moments of generalized parton distributions. We
illustrate a method for extracting generalized parton distributions from
lattice moments based on a reconstruction using sets of orthogonal polynomials.
The inclusion in our fit of data on Deeply Virtual Compton Scattering is also
discussed. Our method provides a step towards a model independent extraction of
generalized distributions from the data. It also provides an alternative to
double distributions based phenomenological models in that we are able to
satisfy the polynomiality condition by construction, using a combination of
experimental data and lattice, without resorting to any specific mathematical
construct.
| [
{
"created": "Thu, 2 Aug 2007 04:11:04 GMT",
"version": "v1"
},
{
"created": "Fri, 31 Aug 2007 20:10:10 GMT",
"version": "v2"
},
{
"created": "Wed, 28 May 2008 15:25:46 GMT",
"version": "v3"
}
] | 2009-09-28 | [
[
"Ahmad",
"Saeed",
""
],
[
"Honkanen",
"Heli",
""
],
[
"Liuti",
"Simonetta",
""
],
[
"Taneja",
"Swadhin K.",
""
]
] | We propose a physically motivated parametrization for the unpolarized generalized parton distributions, H and E, valid at both zero and non-zero values of the skewness variable, \zeta. Our approach follows a previous detailed study of the \zeta=0 case where H and E were determined using constraints from simultaneous fits of the experimental data on both the nucleon elastic form factors and the deep inelastic structure functions in the non singlet sector. Additional constraints at \zeta \neq 0 are provided by lattice calculations of the higher moments of generalized parton distributions. We illustrate a method for extracting generalized parton distributions from lattice moments based on a reconstruction using sets of orthogonal polynomials. The inclusion in our fit of data on Deeply Virtual Compton Scattering is also discussed. Our method provides a step towards a model independent extraction of generalized distributions from the data. It also provides an alternative to double distributions based phenomenological models in that we are able to satisfy the polynomiality condition by construction, using a combination of experimental data and lattice, without resorting to any specific mathematical construct. |
1509.06248 | Dr. Rukmani Mohanta | Suchismita Sahoo and Rukmani Mohanta | Leptoquark effects on $b \to s \nu \bar{\nu}$ and $B \to K l^+ l^-$
decay processes | 24 pages, 10 figures, version to appear in New J. Phys | null | 10.1088/1367-2630/18/1/013032 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the rare semileptonic decays of $B$ mesons induced by $b \to s \nu
\bar{\nu}$ as well as $b \to s l^+ l^-$ transitions in the scalar leptoquark
model where the leptoquarks transform as $(3,2,7/6)$ and $(3,2,1/6)$ under the
standard model gauge group. The leptoquark parameter space is constrained using
the most recent experimental results on ${\rm Br}(B_s \rightarrow \mu^+ \mu^-)$
and ${\rm Br}(B_d \to X_s \mu^+ \mu^-)$ processes. Considering only the baryon
number conserving leptoquark interactions, we estimate the branching ratios for
the exclusive $\bar{B} \rightarrow \bar{K}^{(*)} \nu \bar{\nu}$ and inclusive
$B \rightarrow X_s \nu \bar{\nu}$ decay processes by using the constraint
parameters. We also obtain the low recoil (large lepton invariant mass, i.e.,
$q^2 \sim m^2_b$) predictions for the angular distribution of $\bar B
\rightarrow \bar{K} l^+ l^-$ process and several other observables including
the flat term and lepton flavour non-universality factor in this model.
| [
{
"created": "Mon, 21 Sep 2015 14:38:16 GMT",
"version": "v1"
},
{
"created": "Mon, 11 Jan 2016 05:33:56 GMT",
"version": "v2"
}
] | 2016-02-17 | [
[
"Sahoo",
"Suchismita",
""
],
[
"Mohanta",
"Rukmani",
""
]
] | We study the rare semileptonic decays of $B$ mesons induced by $b \to s \nu \bar{\nu}$ as well as $b \to s l^+ l^-$ transitions in the scalar leptoquark model where the leptoquarks transform as $(3,2,7/6)$ and $(3,2,1/6)$ under the standard model gauge group. The leptoquark parameter space is constrained using the most recent experimental results on ${\rm Br}(B_s \rightarrow \mu^+ \mu^-)$ and ${\rm Br}(B_d \to X_s \mu^+ \mu^-)$ processes. Considering only the baryon number conserving leptoquark interactions, we estimate the branching ratios for the exclusive $\bar{B} \rightarrow \bar{K}^{(*)} \nu \bar{\nu}$ and inclusive $B \rightarrow X_s \nu \bar{\nu}$ decay processes by using the constraint parameters. We also obtain the low recoil (large lepton invariant mass, i.e., $q^2 \sim m^2_b$) predictions for the angular distribution of $\bar B \rightarrow \bar{K} l^+ l^-$ process and several other observables including the flat term and lepton flavour non-universality factor in this model. |
1403.2046 | Malgorzata Worek | G. Bevilacqua and M. Worek | On the ratio of ttbb and ttjj cross sections at the CERN Large Hadron
Collider | 23 pages, 10 figures, 3 tables, some issues clarified,
acknowledgement and references added, version to appear in JHEP | JHEP 1407 (2014) 135 | 10.1007/JHEP07(2014)135 | TTK-14-03 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Triggered by ongoing experimental analyses, we report on a study of the cross
section ratio sigma(pp -> ttbb)/sigma(pp -> ttjj) at the next-to-leading order
in QCD, focusing on both present and future collider energies: sqrt{s}= 7, 8,
13 TeV. In particular, we provide a comparison between our predictions and the
currently available CMS data for the 8 TeV run. We further analyse the
kinematics and scale uncertainties of the two processes for a single set of
parton distribution functions, with the goal of assessing possible correlations
that might help to reduce the theoretical error of the ratio and thus enhance
the predictive power of this observable. We argue that the different jet
kinematics makes the ttbb and ttjj processes uncorrelated in several
observables, and show that the scale uncertainty is not significantly reduced
when taking the ratio of the cross sections.
| [
{
"created": "Sun, 9 Mar 2014 10:34:44 GMT",
"version": "v1"
},
{
"created": "Fri, 6 Jun 2014 15:03:22 GMT",
"version": "v2"
},
{
"created": "Tue, 1 Jul 2014 12:56:14 GMT",
"version": "v3"
}
] | 2014-08-01 | [
[
"Bevilacqua",
"G.",
""
],
[
"Worek",
"M.",
""
]
] | Triggered by ongoing experimental analyses, we report on a study of the cross section ratio sigma(pp -> ttbb)/sigma(pp -> ttjj) at the next-to-leading order in QCD, focusing on both present and future collider energies: sqrt{s}= 7, 8, 13 TeV. In particular, we provide a comparison between our predictions and the currently available CMS data for the 8 TeV run. We further analyse the kinematics and scale uncertainties of the two processes for a single set of parton distribution functions, with the goal of assessing possible correlations that might help to reduce the theoretical error of the ratio and thus enhance the predictive power of this observable. We argue that the different jet kinematics makes the ttbb and ttjj processes uncorrelated in several observables, and show that the scale uncertainty is not significantly reduced when taking the ratio of the cross sections. |
1108.2851 | Malgorzata Worek | G. Bevilacqua, M. Czakon, C. G. Papadopoulos, M. Worek | Hadronic top-quark pair production in association with two jets at
Next-to-Leading Order QCD | 18 pages, 18 figures and 13 tables | Phys. Rev. D 84, 114017 (2011) | 10.1103/PhysRevD.84.114017 | TTK-11-30; WUB/11-08 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We report on the calculation of the next-to-leading order QCD corrections to
the production of ttbar pairs in association with two hard jets at the Fermilab
TeVatron and CERN Large Hadron Collider. Results for the integrated and
differential cross sections are given. The corrections with respect to leading
order are negative and moderate. A study of the scale dependence of our NLO
predictions indicates that the residual theoretical uncertainty, due to higher
order corrections, is 21% for the TeVatron and 15% for the LHC. In case of the
TeVatron, the forward-backward asymmetry of the top quark is calculated for the
first time at next-to-leading order. With the inclusive selection of cuts, this
asymmetry amounts to A_FB = -10.3% at leading order and A_FB = -4.6% at
next-to-leading order. All results presented in this paper have been obtained
with the help of the HELAC-NLO package.
| [
{
"created": "Sun, 14 Aug 2011 08:57:59 GMT",
"version": "v1"
}
] | 2015-03-19 | [
[
"Bevilacqua",
"G.",
""
],
[
"Czakon",
"M.",
""
],
[
"Papadopoulos",
"C. G.",
""
],
[
"Worek",
"M.",
""
]
] | We report on the calculation of the next-to-leading order QCD corrections to the production of ttbar pairs in association with two hard jets at the Fermilab TeVatron and CERN Large Hadron Collider. Results for the integrated and differential cross sections are given. The corrections with respect to leading order are negative and moderate. A study of the scale dependence of our NLO predictions indicates that the residual theoretical uncertainty, due to higher order corrections, is 21% for the TeVatron and 15% for the LHC. In case of the TeVatron, the forward-backward asymmetry of the top quark is calculated for the first time at next-to-leading order. With the inclusive selection of cuts, this asymmetry amounts to A_FB = -10.3% at leading order and A_FB = -4.6% at next-to-leading order. All results presented in this paper have been obtained with the help of the HELAC-NLO package. |
hep-ph/0512359 | Zhenjun Xiao | Zhenjun Xiao, Huihui Cheng and Linxia L\"u | Exclusive $B \to V \gamma$ decays in the T2HDM | RevTex file, 25 pages, 12 eps figures | null | null | NJNU-TH-2005-26 | hep-ph | null | By employing the QCD factorization approach for the exclusive $B \to V
\gamma$ decays, we calculated the new physics contributions to the branching
ratios, CP asymmetries, isospin and U-spin symmetry breaking of $B \to
K^*\gamma$ and $B \to \rho \gamma$ decays, induced by the charged Higgs penguin
diagrams appeared in the top-quark two-Higgs-doublet model(T2HDM). Within the
considered parameter space, we found that (a) a charged-Higgs boson with a mass
larger than 300 GeV are always allowed by the date of $B \to V \gamma$ decay,
and such lower limit on $\mhp$ are comparable with those obtained from the
inclusive $B \to X_s \gamma$ decay; (b) the CP asymmetry of $B \to \rho \gamma$
in the T2HDM can be as large as 10% in magnitude and has a strong dependence on
the angle $\theta$ and the CKM angle $\gamma$; (c) the isospin symmetry
breakings of $B \to V \gamma$ decays in the T2HDM are generally small in size:
around 6% for $B \to K^* \gamma$ decay and less than 20% for $B \to \rho
\gamma$ decay; and (d) the U-spin symmetry breaking $\Delta U(K^*,\rho)$ in the
T2HDM is also small in size, only about 8% of the branching ratio $\calb (B \to
\rho^0 \gamma)$.
| [
{
"created": "Thu, 29 Dec 2005 11:09:46 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Xiao",
"Zhenjun",
""
],
[
"Cheng",
"Huihui",
""
],
[
"Lü",
"Linxia",
""
]
] | By employing the QCD factorization approach for the exclusive $B \to V \gamma$ decays, we calculated the new physics contributions to the branching ratios, CP asymmetries, isospin and U-spin symmetry breaking of $B \to K^*\gamma$ and $B \to \rho \gamma$ decays, induced by the charged Higgs penguin diagrams appeared in the top-quark two-Higgs-doublet model(T2HDM). Within the considered parameter space, we found that (a) a charged-Higgs boson with a mass larger than 300 GeV are always allowed by the date of $B \to V \gamma$ decay, and such lower limit on $\mhp$ are comparable with those obtained from the inclusive $B \to X_s \gamma$ decay; (b) the CP asymmetry of $B \to \rho \gamma$ in the T2HDM can be as large as 10% in magnitude and has a strong dependence on the angle $\theta$ and the CKM angle $\gamma$; (c) the isospin symmetry breakings of $B \to V \gamma$ decays in the T2HDM are generally small in size: around 6% for $B \to K^* \gamma$ decay and less than 20% for $B \to \rho \gamma$ decay; and (d) the U-spin symmetry breaking $\Delta U(K^*,\rho)$ in the T2HDM is also small in size, only about 8% of the branching ratio $\calb (B \to \rho^0 \gamma)$. |
1807.10156 | Florian Goertz | Tommi Alanne, Simone Blasi, and Florian Goertz | A Common Source for Scalars: Axiflavon-Higgs Unification | 8 pages, 2 figures | Phys. Rev. D 99, 015028 (2019) | 10.1103/PhysRevD.99.015028 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose a unified model of scalar particles that addresses the flavour
hierarchies, solves the strong CP problem, delivers a dark matter candidate,
and provides the trigger for electroweak symmetry breaking. Besides furnishing
a unification of the recently proposed axiflavon with a Goldstone-Higgs sector,
the scenario can also be seen as adding a model of flavour (and strong CP
conservation along with axion dark matter) to elementary Goldstone-Higgs
setups. In particular, we derive bounds on the axion decay constant from the
need to generate a SM-like Higgs potential at low energies, which we confront
with constraints from flavour physics and cosmology. In the minimal
implementation, we find that the axion decay constant is restricted to a thin
stripe of $f_a \approx (10^{11}-10^{12})$ GeV, while adding right-handed
neutrinos allows to realize a heavy-axion model at lower energies, down to $f_a
\sim 10$ TeV.
| [
{
"created": "Thu, 26 Jul 2018 14:10:06 GMT",
"version": "v1"
}
] | 2019-01-30 | [
[
"Alanne",
"Tommi",
""
],
[
"Blasi",
"Simone",
""
],
[
"Goertz",
"Florian",
""
]
] | We propose a unified model of scalar particles that addresses the flavour hierarchies, solves the strong CP problem, delivers a dark matter candidate, and provides the trigger for electroweak symmetry breaking. Besides furnishing a unification of the recently proposed axiflavon with a Goldstone-Higgs sector, the scenario can also be seen as adding a model of flavour (and strong CP conservation along with axion dark matter) to elementary Goldstone-Higgs setups. In particular, we derive bounds on the axion decay constant from the need to generate a SM-like Higgs potential at low energies, which we confront with constraints from flavour physics and cosmology. In the minimal implementation, we find that the axion decay constant is restricted to a thin stripe of $f_a \approx (10^{11}-10^{12})$ GeV, while adding right-handed neutrinos allows to realize a heavy-axion model at lower energies, down to $f_a \sim 10$ TeV. |
1212.4436 | Catherine Bernaciak | Catherine Bernaciak, Malte Sean Andreas Buschmann, Anja Butter, and
Tilman Plehn | Fox-Wolfram Moments in Higgs Physics | 12 pages, 8 figures | null | 10.1103/PhysRevD.87.073014 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Geometric correlations between jets as part of hard processes or in addition
to hard processes are key ingredients to many LHC analyses. Fox--Wolfram
moments systematically describe these correlations in terms of spherical
harmonics. These moments, either computed from the tagging jets or from all
jets in each event, can significantly improve Higgs searches in weak boson
fusion. Applications of Fox--Wolfram moments in LHC analyses obviously surpass
jets as analysis objects as well as Higgs searches in terms of analyses.
| [
{
"created": "Tue, 18 Dec 2012 17:33:36 GMT",
"version": "v1"
}
] | 2013-05-01 | [
[
"Bernaciak",
"Catherine",
""
],
[
"Buschmann",
"Malte Sean Andreas",
""
],
[
"Butter",
"Anja",
""
],
[
"Plehn",
"Tilman",
""
]
] | Geometric correlations between jets as part of hard processes or in addition to hard processes are key ingredients to many LHC analyses. Fox--Wolfram moments systematically describe these correlations in terms of spherical harmonics. These moments, either computed from the tagging jets or from all jets in each event, can significantly improve Higgs searches in weak boson fusion. Applications of Fox--Wolfram moments in LHC analyses obviously surpass jets as analysis objects as well as Higgs searches in terms of analyses. |
2108.02700 | Hajime Otsuka | Tatsuo Kobayashi, Hajime Otsuka | On Stringy Origin of Minimal Flavor Violation | 6 pages, v2: published version | Eur. Phys. J. C 82, 25 (2022) | 10.1140/epjc/s10052-022-09986-4 | EPHOU-21-011, KEK-TH-2340 | hep-ph hep-th | http://creativecommons.org/licenses/by/4.0/ | We study the minimal flavor violation in the context of string effective
field theory. Stringy selection rules indicate that $n$-point couplings among
fermionic zero-modes and lightest scalar modes in the string effective action
are given by a product of Yukawa couplings which are regarded as spurion fields
of stringy and geometrical symmetries. Hence, Yukawa couplings determine the
dynamics of flavor and CP violations. This observation strongly supports the
hypothesis of minimal flavor violation in the Standard Model effective field
theory.
| [
{
"created": "Thu, 5 Aug 2021 16:06:49 GMT",
"version": "v1"
},
{
"created": "Tue, 11 Jan 2022 13:51:43 GMT",
"version": "v2"
}
] | 2022-01-12 | [
[
"Kobayashi",
"Tatsuo",
""
],
[
"Otsuka",
"Hajime",
""
]
] | We study the minimal flavor violation in the context of string effective field theory. Stringy selection rules indicate that $n$-point couplings among fermionic zero-modes and lightest scalar modes in the string effective action are given by a product of Yukawa couplings which are regarded as spurion fields of stringy and geometrical symmetries. Hence, Yukawa couplings determine the dynamics of flavor and CP violations. This observation strongly supports the hypothesis of minimal flavor violation in the Standard Model effective field theory. |
2009.11957 | Ben Page | S. Abreu, J. Dormans, F. Febres Cordero, H. Ita, M. Kraus, B. Page, E.
Pascual, M. S. Ruf, V. Sotnikov | Caravel: A C++ Framework for the Computation of Multi-Loop Amplitudes
with Numerical Unitarity | null | null | 10.1016/j.cpc.2021.108069 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the first public version of Caravel, a C++17 framework for the
computation of multi-loop scattering amplitudes in quantum field theory, based
on the numerical unitarity method. Caravel is composed of modules for the
$D$-dimensional decomposition of integrands of scattering amplitudes into
master and surface terms, the computation of tree-level amplitudes in floating
point or finite-field arithmetic, the numerical computation of one- and
two-loop amplitudes in QCD and Einstein gravity, and functional reconstruction
tools. We provide programs that showcase Caravel's main functionalities and
allow to compute selected one- and two-loop amplitudes.
| [
{
"created": "Thu, 24 Sep 2020 21:22:02 GMT",
"version": "v1"
}
] | 2021-07-28 | [
[
"Abreu",
"S.",
""
],
[
"Dormans",
"J.",
""
],
[
"Cordero",
"F. Febres",
""
],
[
"Ita",
"H.",
""
],
[
"Kraus",
"M.",
""
],
[
"Page",
"B.",
""
],
[
"Pascual",
"E.",
""
],
[
"Ruf",
"M. S.",
""
... | We present the first public version of Caravel, a C++17 framework for the computation of multi-loop scattering amplitudes in quantum field theory, based on the numerical unitarity method. Caravel is composed of modules for the $D$-dimensional decomposition of integrands of scattering amplitudes into master and surface terms, the computation of tree-level amplitudes in floating point or finite-field arithmetic, the numerical computation of one- and two-loop amplitudes in QCD and Einstein gravity, and functional reconstruction tools. We provide programs that showcase Caravel's main functionalities and allow to compute selected one- and two-loop amplitudes. |
2012.02070 | Miroslav Myska | Johannes Bellm, Cody B. Duncan, Stefan Gieseke, Miroslav Myska,
Andrzej Siodmok | Parton color reconnection in Herwig 7 using a spacetime event topology | Contribution to: ICHEP 2020 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Herwig 7 is a general-purpose Monte Carlo generator of particle collisions
comprising both hard perturbative as well as soft phenomenological physics.
Herwig is therefore capable to describe the entire final state of hadronized
particles in a collision event. A spacetime topology of a parton system
entering hadronization is fully described and tested for the first time. A
combination of information from particles momenta and spacetime positions is
utilized to minimize a boost-invariant distance measure of the parton system.
We present a reasonable agreement of the model with a selection of experimental
data and conclude that spacetime event topology can be meaningfully used in the
further development.
| [
{
"created": "Thu, 3 Dec 2020 16:58:26 GMT",
"version": "v1"
}
] | 2020-12-04 | [
[
"Bellm",
"Johannes",
""
],
[
"Duncan",
"Cody B.",
""
],
[
"Gieseke",
"Stefan",
""
],
[
"Myska",
"Miroslav",
""
],
[
"Siodmok",
"Andrzej",
""
]
] | Herwig 7 is a general-purpose Monte Carlo generator of particle collisions comprising both hard perturbative as well as soft phenomenological physics. Herwig is therefore capable to describe the entire final state of hadronized particles in a collision event. A spacetime topology of a parton system entering hadronization is fully described and tested for the first time. A combination of information from particles momenta and spacetime positions is utilized to minimize a boost-invariant distance measure of the parton system. We present a reasonable agreement of the model with a selection of experimental data and conclude that spacetime event topology can be meaningfully used in the further development. |
1512.09026 | Masaya Kohda | Kaori Fuyuto, Wei-Shu Hou, Masaya Kohda | Z'-induced FCNC decays of top, beauty and strange quarks | 18 pages, 12 figures; accepted by PRD, references updated | Phys. Rev. D 93, 054021 (2016) | 10.1103/PhysRevD.93.054021 | CYCU-HEP-15-12 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Anomalous b --> s transitions from LHCb data may suggest a new massive gauge
boson Z' that couples to the left-handed b --> s current, which in turn implies
a coupling to the t --> c current. In this paper, we study flavor-changing
neutral current (FCNC) decays of the top quark induced by a Z' boson, namely t
--> c Z', based on a model of the gauged L_mu - L_tau symmetry (the difference
between the muon and tauon numbers) with vector-like quarks, which was
introduced to explain the anomalous LHCb data. We illustrate that searching for
t --> c Z' via Z' --> mu^+ mu^- with LHC Run 1 data can already probe a
parameter region which is unexplored by B physics for the Z' mass around O(10)
GeV or more. We further extend the model to very light Z' with mass below 400
MeV, which is motivated by the muon g-2 anomaly. Taking rare B and K meson
decay data into account, we give upper limits on the t --> c Z' branching ratio
for the light Z' case, and discuss about its observability at the LHC. We also
scrutinize the possibility that the decay K_L --> pi^0 Z' with Z' --> nu nubar
may lead to apparent violation of the usual Grossman-Nir bound of B(K_L -->
pi^0 nu nubar) < 1.4 x 10^-9.
| [
{
"created": "Wed, 30 Dec 2015 17:23:13 GMT",
"version": "v1"
},
{
"created": "Wed, 9 Mar 2016 13:16:39 GMT",
"version": "v2"
}
] | 2016-03-23 | [
[
"Fuyuto",
"Kaori",
""
],
[
"Hou",
"Wei-Shu",
""
],
[
"Kohda",
"Masaya",
""
]
] | Anomalous b --> s transitions from LHCb data may suggest a new massive gauge boson Z' that couples to the left-handed b --> s current, which in turn implies a coupling to the t --> c current. In this paper, we study flavor-changing neutral current (FCNC) decays of the top quark induced by a Z' boson, namely t --> c Z', based on a model of the gauged L_mu - L_tau symmetry (the difference between the muon and tauon numbers) with vector-like quarks, which was introduced to explain the anomalous LHCb data. We illustrate that searching for t --> c Z' via Z' --> mu^+ mu^- with LHC Run 1 data can already probe a parameter region which is unexplored by B physics for the Z' mass around O(10) GeV or more. We further extend the model to very light Z' with mass below 400 MeV, which is motivated by the muon g-2 anomaly. Taking rare B and K meson decay data into account, we give upper limits on the t --> c Z' branching ratio for the light Z' case, and discuss about its observability at the LHC. We also scrutinize the possibility that the decay K_L --> pi^0 Z' with Z' --> nu nubar may lead to apparent violation of the usual Grossman-Nir bound of B(K_L --> pi^0 nu nubar) < 1.4 x 10^-9. |
1207.0761 | Michael Gronau | Bhubanjyoti Bhattacharya, Michael Gronau and Jonathan L. Rosner | Direct CP Violation in D Decays in view of LHCb and CDF Results | minor corrections, reference added | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The LHCb and CDF Collaborations have recently reported evidence for a CP
asymmetry around -0.7% in $\Delta A_{CP}$, the difference between $A_{CP}(D^0
\to K^+ K^-)$ and $A_{CP}(D^0 \to \pi^+\pi^-)$. In the Standard Model this
effect may be accounted for by enhanced $1/m_c$ corrections in a CP-violating
penguin amplitude governed by a Cabibbo-Kobayashi-Maskawa (CKM) factor
$V^*_{cb}V_{ub}$. A consistent scheme based on broken flavor SU(3) is presented
relating Cabibbo-favored (CF) and singly-Cabibbo-suppressed (SCS) $D$ meson
decay rates into two pseudoscalars. Two important ingredients supporting the
above interpretation for $\Delta A_{CP}$ are a large exchange amplitude in CF
decays which is formally $1/m_c$-suppressed, and a pure $\Delta U=0$ U-spin
breaking CP-conserving penguin amplitude involving $V^*_{cs}V_{us}$ and
$V^*_{cd}V_{ud}$ which accounts for the difference between the $D^0\to K^+K^-$
and $D^0\to \pi^+\pi^-$ decay rates. The magnitudes of the CP conserving and CP
violating penguin amplitudes, where the former involves U-spin breaking at a
level of 10%, are shown to be related to each other by the magnitudes of
corresponding CKM factors. This simple scheme leads to preferable sign
predictions for CP asymmetries in charmed meson decays into two pseudoscalars
and to correlations between asymmetries in two pairs of these processes.
| [
{
"created": "Tue, 3 Jul 2012 17:35:00 GMT",
"version": "v1"
},
{
"created": "Tue, 10 Jul 2012 06:26:59 GMT",
"version": "v2"
},
{
"created": "Fri, 27 Jul 2012 19:34:29 GMT",
"version": "v3"
}
] | 2012-07-30 | [
[
"Bhattacharya",
"Bhubanjyoti",
""
],
[
"Gronau",
"Michael",
""
],
[
"Rosner",
"Jonathan L.",
""
]
] | The LHCb and CDF Collaborations have recently reported evidence for a CP asymmetry around -0.7% in $\Delta A_{CP}$, the difference between $A_{CP}(D^0 \to K^+ K^-)$ and $A_{CP}(D^0 \to \pi^+\pi^-)$. In the Standard Model this effect may be accounted for by enhanced $1/m_c$ corrections in a CP-violating penguin amplitude governed by a Cabibbo-Kobayashi-Maskawa (CKM) factor $V^*_{cb}V_{ub}$. A consistent scheme based on broken flavor SU(3) is presented relating Cabibbo-favored (CF) and singly-Cabibbo-suppressed (SCS) $D$ meson decay rates into two pseudoscalars. Two important ingredients supporting the above interpretation for $\Delta A_{CP}$ are a large exchange amplitude in CF decays which is formally $1/m_c$-suppressed, and a pure $\Delta U=0$ U-spin breaking CP-conserving penguin amplitude involving $V^*_{cs}V_{us}$ and $V^*_{cd}V_{ud}$ which accounts for the difference between the $D^0\to K^+K^-$ and $D^0\to \pi^+\pi^-$ decay rates. The magnitudes of the CP conserving and CP violating penguin amplitudes, where the former involves U-spin breaking at a level of 10%, are shown to be related to each other by the magnitudes of corresponding CKM factors. This simple scheme leads to preferable sign predictions for CP asymmetries in charmed meson decays into two pseudoscalars and to correlations between asymmetries in two pairs of these processes. |
1002.4293 | Stefano Frixione | Paolo Torrielli, Stefano Frixione | Matching NLO QCD computations with PYTHIA using MC@NLO | 16 pages, 10 figures. Several comments and two figures have been
added | JHEP 1004:110,2010 | 10.1007/JHEP04(2010)110 | CERN-TH/2010-030 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the matching between a next-to-leading order computation in QCD
and the PYTHIA parton shower Monte Carlo, according to the MC@NLO formalism. We
study the case of initial-state radiation, and consider in particular single
vector boson hadroproduction.
| [
{
"created": "Tue, 23 Feb 2010 10:56:15 GMT",
"version": "v1"
},
{
"created": "Wed, 5 May 2010 09:10:27 GMT",
"version": "v2"
}
] | 2014-11-20 | [
[
"Torrielli",
"Paolo",
""
],
[
"Frixione",
"Stefano",
""
]
] | We present the matching between a next-to-leading order computation in QCD and the PYTHIA parton shower Monte Carlo, according to the MC@NLO formalism. We study the case of initial-state radiation, and consider in particular single vector boson hadroproduction. |
1009.1632 | Laszlo Jenkovszky | L.L. Jenkovszky, Andrea Nagy, S.M. Troshin, Jolan Turoci, N.E. Tyurin | Critical Phenomena in DIS | 20 pages, 8 figures, reported at the CPOD Conference, Dubna, 2010, to
be published in the International Journal of Modern Physics A | Int.J.Mod.Phys.A25:5667-5682,2010 | 10.1142/S0217751X10051104 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Saturation in deep inelastic scattering (DIS) and deeply virtual Compton
scattering (DVCS) is associated with a phase transition between the partonic
gas, typical of moderate $x$ and $Q^2$, and partonic fluid appearing at
increasing $Q^2$ and decreasing Bjorken $x$. In the statistical interpretation
of DIS, the large-$x,(1-x)^n$ factor in the SF is associated with a statistical
distribution (perfect gas), while the low-$x$, Regge behaved factor
$x^{b(Q^2)}$ produces deviations from the perfect gas and ultimately leads to a
gas-liquid phase transition. In this paper we do not intend to propose another
parametrization of the structure function; instead we suggest a new insight
into the internal structure of the nucleon, as seen in DIS, and its connection
with that revealed in high-energy nucleons and heavy-ion collisions.
| [
{
"created": "Wed, 8 Sep 2010 20:04:39 GMT",
"version": "v1"
},
{
"created": "Tue, 5 Oct 2010 09:40:41 GMT",
"version": "v2"
}
] | 2011-01-04 | [
[
"Jenkovszky",
"L. L.",
""
],
[
"Nagy",
"Andrea",
""
],
[
"Troshin",
"S. M.",
""
],
[
"Turoci",
"Jolan",
""
],
[
"Tyurin",
"N. E.",
""
]
] | Saturation in deep inelastic scattering (DIS) and deeply virtual Compton scattering (DVCS) is associated with a phase transition between the partonic gas, typical of moderate $x$ and $Q^2$, and partonic fluid appearing at increasing $Q^2$ and decreasing Bjorken $x$. In the statistical interpretation of DIS, the large-$x,(1-x)^n$ factor in the SF is associated with a statistical distribution (perfect gas), while the low-$x$, Regge behaved factor $x^{b(Q^2)}$ produces deviations from the perfect gas and ultimately leads to a gas-liquid phase transition. In this paper we do not intend to propose another parametrization of the structure function; instead we suggest a new insight into the internal structure of the nucleon, as seen in DIS, and its connection with that revealed in high-energy nucleons and heavy-ion collisions. |
1112.1171 | Ezio Maina | A. Ballestrero, D. Buarque Franzosi, L. Oggero and E. Maina | Vector Boson scattering at the LHC: counting experiments for unitarized
models in a full six fermion approach | version accepted for publication on JHEP | null | 10.1007/JHEP03(2012)031 | DFTT 31/2011 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Unitarization models describe phenomenologically the high energy behaviour of
a strongly interacting symmetry breaking sector. In this work, predictions of
some unitarized models in vector boson scattering at LHC are studied and
compared with analogous studies in Equivalent Vector Boson Approximation and
previous results for the benchmark no-Higgs scenario. To perform such studies,
unitarized model amplitudes have been implemented in the PHANTOM Monte Carlo in
a complete calculation with six fermions in the final state.
| [
{
"created": "Tue, 6 Dec 2011 06:54:07 GMT",
"version": "v1"
},
{
"created": "Fri, 16 Mar 2012 15:47:31 GMT",
"version": "v2"
}
] | 2015-06-03 | [
[
"Ballestrero",
"A.",
""
],
[
"Franzosi",
"D. Buarque",
""
],
[
"Oggero",
"L.",
""
],
[
"Maina",
"E.",
""
]
] | Unitarization models describe phenomenologically the high energy behaviour of a strongly interacting symmetry breaking sector. In this work, predictions of some unitarized models in vector boson scattering at LHC are studied and compared with analogous studies in Equivalent Vector Boson Approximation and previous results for the benchmark no-Higgs scenario. To perform such studies, unitarized model amplitudes have been implemented in the PHANTOM Monte Carlo in a complete calculation with six fermions in the final state. |
1509.03377 | Hong-Shi Zong | Tong Zhao, Shu-Sheng Xu, Yan Yan, Xin-Lian Luo, Xiao-Jun Liu, Hong-Shi
Zong | Studies of two-solar-mass hybrid stars within the framework of
Dyson-Schwinger equations | null | null | 10.1103/PhysRevD.92.054012 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper we introduce an equation of state (EOS) of quark matter within
the framework of Dyson-Schwinger equations (DSEs) to study the structure of
compact stars. The smooth crossover from hadronic matter to quark matter in the
hybrid star is studied. We compare different strategies to obtain crossover
EOSs and find a new way to construct two-solar-mass hybrid stars with even a
relatively soft quark EOS, while earlier works show that the quark EOS should
be stiff enough to support a massive hybrid star.
| [
{
"created": "Fri, 11 Sep 2015 02:59:29 GMT",
"version": "v1"
}
] | 2015-09-14 | [
[
"Zhao",
"Tong",
""
],
[
"Xu",
"Shu-Sheng",
""
],
[
"Yan",
"Yan",
""
],
[
"Luo",
"Xin-Lian",
""
],
[
"Liu",
"Xiao-Jun",
""
],
[
"Zong",
"Hong-Shi",
""
]
] | In this paper we introduce an equation of state (EOS) of quark matter within the framework of Dyson-Schwinger equations (DSEs) to study the structure of compact stars. The smooth crossover from hadronic matter to quark matter in the hybrid star is studied. We compare different strategies to obtain crossover EOSs and find a new way to construct two-solar-mass hybrid stars with even a relatively soft quark EOS, while earlier works show that the quark EOS should be stiff enough to support a massive hybrid star. |
1609.02307 | Yong Tang | P. Ko, Yong Tang | Residual Non-Abelian Dark Matter and Dark Radiation | 17 pages, 6 figures, updated discussions; Published version | Phys.Lett. B768 (2017) 12-17 | 10.1016/j.physletb.2017.02.033 | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose a novel particle physics model in which vector dark matter (VDM)
and dark radiation (DR) originate from the same non-Abelian dark sector. We
show an illustrating example where dark $SU(3)$ is spontaneously broken into
$SU(2)$ subgroup by the nonzero vacuum expectation value of a complex scalar in
fundamental representation of $SU(3)$. The massless gauge bosons associated
with the residual unbroken $SU(2)$ constitute DR and help to relieve the
tension in Hubble constant measurements between $\textit{Planck}$ and Hubble
Space Telescope. In the meantime, massive dark gauge bosons associated with the
broken generators are VDM candidates. Intrinsically, this non-Abelian VDM can
interact with non-Abelian DR in the cosmic background, which results in a
suppressed matter power spectrum and leads to a smaller $\sigma_8$ for
structure formation.
| [
{
"created": "Thu, 8 Sep 2016 07:37:09 GMT",
"version": "v1"
},
{
"created": "Thu, 3 Nov 2016 13:01:08 GMT",
"version": "v2"
},
{
"created": "Wed, 22 Feb 2017 13:16:49 GMT",
"version": "v3"
}
] | 2017-03-01 | [
[
"Ko",
"P.",
""
],
[
"Tang",
"Yong",
""
]
] | We propose a novel particle physics model in which vector dark matter (VDM) and dark radiation (DR) originate from the same non-Abelian dark sector. We show an illustrating example where dark $SU(3)$ is spontaneously broken into $SU(2)$ subgroup by the nonzero vacuum expectation value of a complex scalar in fundamental representation of $SU(3)$. The massless gauge bosons associated with the residual unbroken $SU(2)$ constitute DR and help to relieve the tension in Hubble constant measurements between $\textit{Planck}$ and Hubble Space Telescope. In the meantime, massive dark gauge bosons associated with the broken generators are VDM candidates. Intrinsically, this non-Abelian VDM can interact with non-Abelian DR in the cosmic background, which results in a suppressed matter power spectrum and leads to a smaller $\sigma_8$ for structure formation. |
hep-ph/0610385 | Makiko Nagashima | Wei-Shu Hou, Makiko Nagashima and Andrea Soddu | Large Time-dependent CP Violation in B_s^0 System and Finite D^0-D^0bar
Mass Difference in Four Generation Standard Mode | 5 pages, 3 figures added (to total of 11 figures), revision to
clarify b -> s photon contrast with Bs and D mixing | Phys.Rev.D76:016004,2007 | 10.1103/PhysRevD.76.016004 | null | hep-ph | null | Combining the measured B_s mixing with b \to s\ell^+\ell^- rate data, we find
a sizable 4 generation t' quark effect is allowed, for example with m_{t'} \sim
300 GeV and V_{t's}^*V_{t'b} \sim 0.025 e^{\pm i 70^\circ}, which could underly
the new physics indications in CP violation studies of b \to s qbar q
transitions. With positive phase, large and negative mixing-dependent CP
violation in B_s system is predicted, \sin 2\Phi_{B_s} \sim -0.5 to -0.7. This
can also be probed via width difference methods. As a corollary, the short
distance generated D^0-D^0bar mass difference is found to be consistent with,
if not slightly higher than, recent B factory measurements, while CP violation
is subdued with \sin 2\Phi_D \sim -0.2.
| [
{
"created": "Sat, 28 Oct 2006 17:00:46 GMT",
"version": "v1"
},
{
"created": "Mon, 6 Nov 2006 16:12:31 GMT",
"version": "v2"
},
{
"created": "Mon, 19 Mar 2007 15:28:45 GMT",
"version": "v3"
},
{
"created": "Tue, 5 Jun 2007 18:34:32 GMT",
"version": "v4"
}
] | 2008-11-26 | [
[
"Hou",
"Wei-Shu",
""
],
[
"Nagashima",
"Makiko",
""
],
[
"Soddu",
"Andrea",
""
]
] | Combining the measured B_s mixing with b \to s\ell^+\ell^- rate data, we find a sizable 4 generation t' quark effect is allowed, for example with m_{t'} \sim 300 GeV and V_{t's}^*V_{t'b} \sim 0.025 e^{\pm i 70^\circ}, which could underly the new physics indications in CP violation studies of b \to s qbar q transitions. With positive phase, large and negative mixing-dependent CP violation in B_s system is predicted, \sin 2\Phi_{B_s} \sim -0.5 to -0.7. This can also be probed via width difference methods. As a corollary, the short distance generated D^0-D^0bar mass difference is found to be consistent with, if not slightly higher than, recent B factory measurements, while CP violation is subdued with \sin 2\Phi_D \sim -0.2. |
1007.1126 | Hans-Werner Hammer | P. Hagen, H.-W. Hammer, C. Hanhart | Two- and three-body structure of the Y(4660) | 15 pages, 7 figures, final version, presentation improved | Phys.Lett.B696:103-108,2011 | 10.1016/j.physletb.2010.12.021 | FZJ-IKP(TH)-2010-14; HISKP-TH-10-13 | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study general features of three-meson bound states using the Y(4660) as an
example. Here the Y(4660) is assumed to be either a two-body bound state of the
f_0(980), itself a bound state of K and Kbar, and the psi'= psi(2s), or a
three-body bound state of psi', K, and Kbar. In particular, we investigate in
detail the interplay of the various scales inherent in the problem, namely the
f_0 binding energy, the Y binding energy, and the K-psi' scattering length.
This allows us to understand under which circumstances the substructure of the
f_0(980) can be neglected in the description of the Y(4660).
| [
{
"created": "Wed, 7 Jul 2010 13:01:48 GMT",
"version": "v1"
},
{
"created": "Wed, 15 Aug 2012 11:07:02 GMT",
"version": "v2"
}
] | 2012-08-16 | [
[
"Hagen",
"P.",
""
],
[
"Hammer",
"H. -W.",
""
],
[
"Hanhart",
"C.",
""
]
] | We study general features of three-meson bound states using the Y(4660) as an example. Here the Y(4660) is assumed to be either a two-body bound state of the f_0(980), itself a bound state of K and Kbar, and the psi'= psi(2s), or a three-body bound state of psi', K, and Kbar. In particular, we investigate in detail the interplay of the various scales inherent in the problem, namely the f_0 binding energy, the Y binding energy, and the K-psi' scattering length. This allows us to understand under which circumstances the substructure of the f_0(980) can be neglected in the description of the Y(4660). |
1305.0400 | Dieter Schildknecht | Masaaki Kuroda and Dieter Schildknecht | On Ultrahigh-energy Neutrino Scattering | 18 pages, 6 figures, Expanded comparison with results in the
literature | null | 10.1103/PhysRevD.88.053007 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We predict the neutrino-nucleon cross section at ultrahigh energies relevant
in connection with the search for high-energy cosmic neutrinos. Our
investigation, employing the color-dipole picture, among other things allows us
to quantitatively determine which fraction of the ultrahigh-energy
neutrino-nucleon cross section stems from the saturation versus the
color-transparency region. We disagree with various results in the literature
that predict a strong suppression of the neutrino-nucleon cross section at
neutrino energies above $E \cong 10^9 GeV$. Suppression in the sense of a
diminished increase of the neutrino-nucleon cross section with energy only
starts to occur at neutrino energies beyond $E \cong 10^{14} GeV$.
| [
{
"created": "Thu, 2 May 2013 11:26:57 GMT",
"version": "v1"
},
{
"created": "Fri, 10 May 2013 10:43:11 GMT",
"version": "v2"
},
{
"created": "Tue, 13 Aug 2013 12:10:07 GMT",
"version": "v3"
}
] | 2013-09-25 | [
[
"Kuroda",
"Masaaki",
""
],
[
"Schildknecht",
"Dieter",
""
]
] | We predict the neutrino-nucleon cross section at ultrahigh energies relevant in connection with the search for high-energy cosmic neutrinos. Our investigation, employing the color-dipole picture, among other things allows us to quantitatively determine which fraction of the ultrahigh-energy neutrino-nucleon cross section stems from the saturation versus the color-transparency region. We disagree with various results in the literature that predict a strong suppression of the neutrino-nucleon cross section at neutrino energies above $E \cong 10^9 GeV$. Suppression in the sense of a diminished increase of the neutrino-nucleon cross section with energy only starts to occur at neutrino energies beyond $E \cong 10^{14} GeV$. |
hep-ph/0107186 | Carlos Pe\~na Garay | Andr\'e de Gouv\^ea and C. Pe\~na-Garay | Solving the Solar Neutrino Puzzle with KamLAND and Solar Data | Manuscript unchanged, pdf version fixed. Some figures bitmapped. High
resolution figures at http://ific.uv.es/~penya | Phys.Rev. D64 (2001) 113011 | 10.1103/PhysRevD.64.113011 | CERN-TH/2001-187, IFIC-01/36 | hep-ph hep-ex | null | We study what will be learnt about the solar neutrino puzzle and solar
neutrino oscillations once the data from the KamLAND reactor neutrino
experiment (soon to become available) are combined with those from the current
solar neutrino experiments. We find that, in agreement with previous estimates,
if the solution to the solar neutrino puzzle falls on the LMA region, KamLAND
should be able to ``pin-point'' the right solution with unprecedented accuracy
after a few years of data taking. Furthermore, the light side ($\theta<\pi/4$)
can be separated from the dark side ($\theta>\pi/4$) at the 95% confidence
level (CL) for most of the LMA region allowed by the current data at the 99%
CL, while the addition of the KamLAND data need not improve our ability to
limit a sterile component in ``solar'' oscillations. If KamLAND does not see an
oscillation signal, the solar data would point to the LOW/VAC regions, while
the SMA region would still lurk at the two sigma CL, meaning we would probably
have to wait for Borexino data in order to finally piece the solar neutrino
puzzle.
| [
{
"created": "Tue, 17 Jul 2001 09:11:30 GMT",
"version": "v1"
},
{
"created": "Tue, 31 Jul 2001 14:40:01 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"de Gouvêa",
"André",
""
],
[
"Peña-Garay",
"C.",
""
]
] | We study what will be learnt about the solar neutrino puzzle and solar neutrino oscillations once the data from the KamLAND reactor neutrino experiment (soon to become available) are combined with those from the current solar neutrino experiments. We find that, in agreement with previous estimates, if the solution to the solar neutrino puzzle falls on the LMA region, KamLAND should be able to ``pin-point'' the right solution with unprecedented accuracy after a few years of data taking. Furthermore, the light side ($\theta<\pi/4$) can be separated from the dark side ($\theta>\pi/4$) at the 95% confidence level (CL) for most of the LMA region allowed by the current data at the 99% CL, while the addition of the KamLAND data need not improve our ability to limit a sterile component in ``solar'' oscillations. If KamLAND does not see an oscillation signal, the solar data would point to the LOW/VAC regions, while the SMA region would still lurk at the two sigma CL, meaning we would probably have to wait for Borexino data in order to finally piece the solar neutrino puzzle. |
1506.05311 | Riccardo Fabbricatore | Alexander Dmitriev, Riccardo Fabbricatore, Alexander Studenikin | Neutrino electromagnetic properties: new approach to oscillations in
magnetic fields | 14 pages in Latex, based on the lecture presented by A.Studenikin at
the Summer School on Standard Model and Beyond in the Corfu Summer Institute
2014, to appear in the PoS | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Several new and interesting aspects of neutrino oscillations in a magnetic
field are considered: 1) We develop a standard usually used approach to the
neutrino spin oscillations in the neutrino mass basis and obtain the effective
neutrino spin (and "spin-mass") oscillation Hamiltonian that can be used for
description of the neutrino oscillations between different pairs of neutrino
states with different masses and helicities; 2) We derive the exact solution of
the Dirac equation for a massive neutrino with nonzero magnetic moment in the
presence of a constant transversal magnetic field that is rotating along the
direction of the neutrino propagation (the twisting magnetic field) and on the
basis of the obtained energy spectrum the neutrino spin oscillation effective
Hamiltonian is derive; 3) We develop a new approach to neutrino spin
oscillations that is based on the description of the neutrino spin states with
the corresponding spin operator that commutes with the neutrino dynamics
Hamiltonian in the magnetic field. The obtained new results can have important
phenomenological applications.
| [
{
"created": "Mon, 15 Jun 2015 15:36:32 GMT",
"version": "v1"
}
] | 2015-06-18 | [
[
"Dmitriev",
"Alexander",
""
],
[
"Fabbricatore",
"Riccardo",
""
],
[
"Studenikin",
"Alexander",
""
]
] | Several new and interesting aspects of neutrino oscillations in a magnetic field are considered: 1) We develop a standard usually used approach to the neutrino spin oscillations in the neutrino mass basis and obtain the effective neutrino spin (and "spin-mass") oscillation Hamiltonian that can be used for description of the neutrino oscillations between different pairs of neutrino states with different masses and helicities; 2) We derive the exact solution of the Dirac equation for a massive neutrino with nonzero magnetic moment in the presence of a constant transversal magnetic field that is rotating along the direction of the neutrino propagation (the twisting magnetic field) and on the basis of the obtained energy spectrum the neutrino spin oscillation effective Hamiltonian is derive; 3) We develop a new approach to neutrino spin oscillations that is based on the description of the neutrino spin states with the corresponding spin operator that commutes with the neutrino dynamics Hamiltonian in the magnetic field. The obtained new results can have important phenomenological applications. |
hep-ph/9502297 | Bodenmueller | Harald Fritzsch, Zhi-zong Xing | A Symmetry Pattern of Maximal CP-Violation and a Determination of the
Unitarity Triangle | 7 latex pages | Phys.Lett.B353:114-118,1995 | 10.1016/0370-2693(95)00545-V | MPI-PhT/95-08 | hep-ph | null | Within a specific texture of the quark mass matrix the notion of a maximal
violation of the $CP$ symmetry can be defined. The experimental constraints
from weak decays imply that in reality one is close to the case of maximal $CP$
violation, which vanishes as the mass of the $u$--quark approaches zero. The
unitarity triangle of the Cabibbo--Kobayashi--Maskawa matrix elements is
determined. It is related to the triangle relating the Cabibbo angle to the
quark mass ratios in the complex plane. The angle $\alpha $ describing the $CP$
violation in the decay $B_d \rightarrow \pi^+ \pi^-$ is close to 90$^{\circ }$.
| [
{
"created": "Tue, 14 Feb 1995 14:33:59 GMT",
"version": "v1"
}
] | 2010-11-01 | [
[
"Fritzsch",
"Harald",
""
],
[
"Xing",
"Zhi-zong",
""
]
] | Within a specific texture of the quark mass matrix the notion of a maximal violation of the $CP$ symmetry can be defined. The experimental constraints from weak decays imply that in reality one is close to the case of maximal $CP$ violation, which vanishes as the mass of the $u$--quark approaches zero. The unitarity triangle of the Cabibbo--Kobayashi--Maskawa matrix elements is determined. It is related to the triangle relating the Cabibbo angle to the quark mass ratios in the complex plane. The angle $\alpha $ describing the $CP$ violation in the decay $B_d \rightarrow \pi^+ \pi^-$ is close to 90$^{\circ }$. |
1911.02797 | Abdel Nasser Tawfik | Abdel Nasser Tawfik (Nile U., ECTP and Johann Wolfgang
Goethe-Universitat), Carsten Greiner (Johann Wolfgang Goethe-Universitat) | Bulk viscosity in strong and electroweak matter | 21 pages, 5 figures | Int. J. Mod. Phys. E, 30, No. 8 (2021) 2150067 | 10.1142/S0218301321500671 | ECTP-2019-07, WLCAPP-2019-07 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | For temperatures $T$ ranging from a few MeV up to TeV and energy density
$\rho$ up to $10^{16}~$GeV/fm$^3$, the bulk viscosity $\zeta$ is calculated in
non-perturbation (up, down, strange, charm, and bottom) and perturbation
theories with up, down, strange, charm, bottom, and top quark flavors, at
vanishing baryon-chemical potential. To these calculations, results deduced
from the effective QCD-like model, the Polyakov linear-sigma model (PLSM), are
also integrated in. The PLSM merely comes up with essential contributions for
the vacuum and thermal condensations of the gluons and the quarks (up, down,
strange, and charm flavors). Furthermore, the thermal contributions of the
photons, neutrinos, charged leptons, electroweak particles, and scalar Higgs
boson, are found very significant along the entire range of $T$ and $\rho$ and
therefore could be well integrated in. We present the dimensionless quantity $9
\omega_0 \zeta/Ts$, where $\omega_0$ is a perturbative scale and $s$ is the
entropy density and conclude that $9 \omega_0 \zeta/Ts$ exponentially decreases
with increasing $T$. We also conclude that the resulting $\zeta$ with the
non-perturbative and perturbative QCD contributions non-monotonically increases
with increasing $\rho$. But with nearly-entire standard model contributions
considered in the present study, $\zeta$ almost-linearly increases with
increasing $\rho$. Apparently, these results offer a great deal to explore in
astrophysics, cosmology, and nuclear collisions.
| [
{
"created": "Thu, 7 Nov 2019 08:20:15 GMT",
"version": "v1"
},
{
"created": "Sat, 30 May 2020 10:43:22 GMT",
"version": "v2"
},
{
"created": "Tue, 5 Oct 2021 10:20:23 GMT",
"version": "v3"
}
] | 2021-10-06 | [
[
"Tawfik",
"Abdel Nasser",
"",
"Nile U., ECTP and Johann Wolfgang\n Goethe-Universitat"
],
[
"Greiner",
"Carsten",
"",
"Johann Wolfgang Goethe-Universitat"
]
] | For temperatures $T$ ranging from a few MeV up to TeV and energy density $\rho$ up to $10^{16}~$GeV/fm$^3$, the bulk viscosity $\zeta$ is calculated in non-perturbation (up, down, strange, charm, and bottom) and perturbation theories with up, down, strange, charm, bottom, and top quark flavors, at vanishing baryon-chemical potential. To these calculations, results deduced from the effective QCD-like model, the Polyakov linear-sigma model (PLSM), are also integrated in. The PLSM merely comes up with essential contributions for the vacuum and thermal condensations of the gluons and the quarks (up, down, strange, and charm flavors). Furthermore, the thermal contributions of the photons, neutrinos, charged leptons, electroweak particles, and scalar Higgs boson, are found very significant along the entire range of $T$ and $\rho$ and therefore could be well integrated in. We present the dimensionless quantity $9 \omega_0 \zeta/Ts$, where $\omega_0$ is a perturbative scale and $s$ is the entropy density and conclude that $9 \omega_0 \zeta/Ts$ exponentially decreases with increasing $T$. We also conclude that the resulting $\zeta$ with the non-perturbative and perturbative QCD contributions non-monotonically increases with increasing $\rho$. But with nearly-entire standard model contributions considered in the present study, $\zeta$ almost-linearly increases with increasing $\rho$. Apparently, these results offer a great deal to explore in astrophysics, cosmology, and nuclear collisions. |
1812.00107 | Jingya Zhu | Lijia Liu, Haoxue Qiao, Kun Wang, Jingya Zhu | A Light Scalar in the Minimal Dilaton Model in Light of LHC Constraints | 13 pages, 4 figures, accepted by Chin.Phys.C | null | 10.1088/1674-1137/43/2/023104 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Whether an additional light scalar exists is an interesting topic beyond the
Standard Model (SM), while nowadays we do not know exactly physics beyond the
SM in the low mass region, e.g., the Atlas and CMS collaborations get
inconsistent results at around 95 GeV in searching for light resonances in
diphoton channel. Considering these, we study a light scalar in the Minimal
Dilaton Model (MDM). Under the theoretical and latest experimental constraints,
we sort the surviving samples into two scenarios according to the diphoton rate
of the light scalar: the large-diphoton scenario (with $/SM\gtrsim0.2$) and the
small-diphoton scenario (with $/SM\lesssim0.2$), which are favored by CMS and
Atlas results respectively. We compare the two scenarios, check the
characteristics in model parameters, scalar couplings, production and decay,
and consider further distinguishing them at colliders. Finally, we get the
following conclusions for the two scenarios: (i) The formal usually has small
Higgs-dilaton mixing angle ($|\sin\theta_S|\lesssim0.2$) and small dilaton
vacuum expectation value (VEV) $f$ ($0.5\lesssim\eta\equiv v/f\lesssim1$), and
the later usually has large mixing ($|\sin\theta_S|\gtrsim0.4$) or large VEV
($\eta\equiv v/f\lesssim0.3$). (ii) The former usually predicts small
$s\gamma\gamma$ coupling ($|C_{s\gamma\gamma}/SM|\lesssim0.3$) and large $sgg$
coupling ($0.6\lesssim|C_{sgg}/SM|\lesssim1.2$), while the later usually
predicts small $sgg$ coupling ($|C_{sgg}/SM|\lesssim0.5$). (iii) The former can
interpret the small diphoton excess by CMS at its central value, when
$m_s\simeq$95GeV, $\eta\simeq0.6$ and $|\sin\theta_S|\simeq0$. (iv) The former
usually predicts a negative correlation between Higgs couplings
$|C_{h\gamma\gamma}/SM|$ and $|C_{hgg}/SM|$, while the later usually predicts
the two couplings both smaller than 1, or $|C_{h\gamma\gamma}/SM|\lesssim0.9
\lesssim|C_{hgg}/SM|$.
| [
{
"created": "Sat, 1 Dec 2018 00:42:40 GMT",
"version": "v1"
}
] | 2019-03-27 | [
[
"Liu",
"Lijia",
""
],
[
"Qiao",
"Haoxue",
""
],
[
"Wang",
"Kun",
""
],
[
"Zhu",
"Jingya",
""
]
] | Whether an additional light scalar exists is an interesting topic beyond the Standard Model (SM), while nowadays we do not know exactly physics beyond the SM in the low mass region, e.g., the Atlas and CMS collaborations get inconsistent results at around 95 GeV in searching for light resonances in diphoton channel. Considering these, we study a light scalar in the Minimal Dilaton Model (MDM). Under the theoretical and latest experimental constraints, we sort the surviving samples into two scenarios according to the diphoton rate of the light scalar: the large-diphoton scenario (with $/SM\gtrsim0.2$) and the small-diphoton scenario (with $/SM\lesssim0.2$), which are favored by CMS and Atlas results respectively. We compare the two scenarios, check the characteristics in model parameters, scalar couplings, production and decay, and consider further distinguishing them at colliders. Finally, we get the following conclusions for the two scenarios: (i) The formal usually has small Higgs-dilaton mixing angle ($|\sin\theta_S|\lesssim0.2$) and small dilaton vacuum expectation value (VEV) $f$ ($0.5\lesssim\eta\equiv v/f\lesssim1$), and the later usually has large mixing ($|\sin\theta_S|\gtrsim0.4$) or large VEV ($\eta\equiv v/f\lesssim0.3$). (ii) The former usually predicts small $s\gamma\gamma$ coupling ($|C_{s\gamma\gamma}/SM|\lesssim0.3$) and large $sgg$ coupling ($0.6\lesssim|C_{sgg}/SM|\lesssim1.2$), while the later usually predicts small $sgg$ coupling ($|C_{sgg}/SM|\lesssim0.5$). (iii) The former can interpret the small diphoton excess by CMS at its central value, when $m_s\simeq$95GeV, $\eta\simeq0.6$ and $|\sin\theta_S|\simeq0$. (iv) The former usually predicts a negative correlation between Higgs couplings $|C_{h\gamma\gamma}/SM|$ and $|C_{hgg}/SM|$, while the later usually predicts the two couplings both smaller than 1, or $|C_{h\gamma\gamma}/SM|\lesssim0.9 \lesssim|C_{hgg}/SM|$. |
hep-ph/0611069 | Kang Young Lee | Yeong Gyun Kim (Sejong U.), Kang Young Lee (KAIST) | The minimal model of fermionic dark matter | 6 pages, 2 figures | Phys.Rev.D75:115012,2007 | 10.1103/PhysRevD.75.115012 | KAIST-TH 2006/04 | hep-ph | null | We explore the minimal extension of the Standard Model with fermionic cold
dark matter. The interactions between the dark matter and the Standard Model
matters are described by the non-renormalizable dimension-5 term. We show that
the measured relic abundance of the cold dark matter can be explained in our
model and predict the direct detection cross section. The direct search of the
dark matter provides severe constraints on the mass and coupling of the minimal
fermionic dark matter with respect to the Higgs boson mass.
| [
{
"created": "Tue, 7 Nov 2006 05:09:12 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Kim",
"Yeong Gyun",
"",
"Sejong U."
],
[
"Lee",
"Kang Young",
"",
"KAIST"
]
] | We explore the minimal extension of the Standard Model with fermionic cold dark matter. The interactions between the dark matter and the Standard Model matters are described by the non-renormalizable dimension-5 term. We show that the measured relic abundance of the cold dark matter can be explained in our model and predict the direct detection cross section. The direct search of the dark matter provides severe constraints on the mass and coupling of the minimal fermionic dark matter with respect to the Higgs boson mass. |
1107.0279 | Sergei Gninenko | S.N. Gninenko | Sterile neutrino decay as a common origin for LSND/MiniBooNe and T2K
excess events | 5 pages, 5 figures. Revised version accepted by PRD (Rapid Comm.)
after referee's suggestions. Fig.1 added for illustration | Phys. Rev. D85 (2012) 051702(R) | 10.1103/PhysRevD.85.051702 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We point out that the excess of electron-like neutrino events recently
observed by the T2K collaboration may have a common origin with the similar
excess events previously reported by the LSND and MiniBooNE experiments and
interpreted as a signal from the radiative decays of a sterile neutrino \nu_h
with the mass around 50 MeV produced in muon neutrino neutral current (NC)
interactions. In this work we assumed that the \nu_h can also be produced in
tau neutrino NC reactions.
| [
{
"created": "Fri, 1 Jul 2011 17:22:07 GMT",
"version": "v1"
},
{
"created": "Tue, 28 Feb 2012 17:30:51 GMT",
"version": "v2"
}
] | 2012-03-16 | [
[
"Gninenko",
"S. N.",
""
]
] | We point out that the excess of electron-like neutrino events recently observed by the T2K collaboration may have a common origin with the similar excess events previously reported by the LSND and MiniBooNE experiments and interpreted as a signal from the radiative decays of a sterile neutrino \nu_h with the mass around 50 MeV produced in muon neutrino neutral current (NC) interactions. In this work we assumed that the \nu_h can also be produced in tau neutrino NC reactions. |
hep-ph/0510228 | Cong-Feng Qiao | Cong-Feng Qiao (GUCAS) | One Explanation for the Exotic State Y(4260) | five text pages, one ps figure. Version to appear in PLB | Phys.Lett.B639:263-265,2006 | 10.1016/j.physletb.2006.06.038 | GUCAS-SPS-0505 | hep-ph | null | In this Letter we interpret the Y(4260), a state recently discovered by the
BaBar Collaboration that has a mass within the range of conventional charmonium
states, as having a molecular-state structure. In our scheme this
molecular-like state is not constructed out of two-quark mesons, but rather out
of baryons, i.e., the Y(4260) is a baryonium state. With this interpretation,
the unusual measured properties of the Y(4260) are easily understood and some
further peculiar decay characteristics are predicted.
| [
{
"created": "Tue, 18 Oct 2005 05:43:12 GMT",
"version": "v1"
},
{
"created": "Mon, 10 Apr 2006 07:05:40 GMT",
"version": "v2"
},
{
"created": "Wed, 21 Jun 2006 15:54:42 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Qiao",
"Cong-Feng",
"",
"GUCAS"
]
] | In this Letter we interpret the Y(4260), a state recently discovered by the BaBar Collaboration that has a mass within the range of conventional charmonium states, as having a molecular-state structure. In our scheme this molecular-like state is not constructed out of two-quark mesons, but rather out of baryons, i.e., the Y(4260) is a baryonium state. With this interpretation, the unusual measured properties of the Y(4260) are easily understood and some further peculiar decay characteristics are predicted. |
hep-ph/0503265 | Toshifumi Yamashita | Toshifumi Yamashita | Anomalous U(1) GUT | Ph.D. thesis. 91 pages, 4 figures | null | null | null | hep-ph | null | We have proposed a very attractive scenario of Grand Unified
Theories (GUTs). It employs the supersymmetry (SUSY) and an anomalous U(1)
symmetry whose anomaly is canceled via the Green-Schwarz mechanism. In this
scenario, the doublet-triplet splitting problem is solved and the success of
the gauge coupling unification in the minimal SU(5) GUT is naturally explained
with sufficiently stable nucleon. Realistic fermion Yukawa matrices can also be
realized simultaneously. In addition, a horizontal symmetry helps to solve the
SUSY-flavor problem.
| [
{
"created": "Sat, 26 Mar 2005 11:45:37 GMT",
"version": "v1"
}
] | 2016-09-06 | [
[
"Yamashita",
"Toshifumi",
""
]
] | We have proposed a very attractive scenario of Grand Unified Theories (GUTs). It employs the supersymmetry (SUSY) and an anomalous U(1) symmetry whose anomaly is canceled via the Green-Schwarz mechanism. In this scenario, the doublet-triplet splitting problem is solved and the success of the gauge coupling unification in the minimal SU(5) GUT is naturally explained with sufficiently stable nucleon. Realistic fermion Yukawa matrices can also be realized simultaneously. In addition, a horizontal symmetry helps to solve the SUSY-flavor problem. |
hep-ph/9602298 | Xuemin Jin | Xuemin Jin | Isospin Breaking in the Nucleon Isovector Axial Charge from QCD Sum
Rules | 11 pages in RevTeX including one PS figure, uses epsf.sty and
rotate.sty (included), uuencoded | null | null | TRI-PP-96-2 | hep-ph nucl-th | null | The isospin breaking in the nucleon isovector axial charge, $g_A^3$, are
calculated within the external field QCD sum-rule approach. The isospin
violations arising from the difference in up and down current quark masses and
in up and down quark condensates are included; electromagnetic effects are not
considered. We find $\delta g^3_A/g^3_A \approx (0.5-1.0)\times 10^{-2}$, where
$\delta g^3_A = (g^3_A)_p + (g^3_A)_n$ and $ g^3_A = [(g^3_A)_p -
(g^3_A)_n]/2$. Using the Goldberger-Treiman relation, we also obtain an
estimate of the isospin breaking in the pion-nucleon coupling constant,
$(g_{pp\pi_0}-g_{nn\pi_0})/g_{NN\pi} \approx (2-7) \times 10^{-3}$.
| [
{
"created": "Tue, 13 Feb 1996 22:42:38 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Jin",
"Xuemin",
""
]
] | The isospin breaking in the nucleon isovector axial charge, $g_A^3$, are calculated within the external field QCD sum-rule approach. The isospin violations arising from the difference in up and down current quark masses and in up and down quark condensates are included; electromagnetic effects are not considered. We find $\delta g^3_A/g^3_A \approx (0.5-1.0)\times 10^{-2}$, where $\delta g^3_A = (g^3_A)_p + (g^3_A)_n$ and $ g^3_A = [(g^3_A)_p - (g^3_A)_n]/2$. Using the Goldberger-Treiman relation, we also obtain an estimate of the isospin breaking in the pion-nucleon coupling constant, $(g_{pp\pi_0}-g_{nn\pi_0})/g_{NN\pi} \approx (2-7) \times 10^{-3}$. |
hep-ph/0411048 | Ana Curiel | E. Arganda, A. M. Curiel, M. J. Herrero and D. Temes | Lepton flavor violating Higgs boson decays in the MSSM-seesaw | Talk given by M. J. Herrero at the Vth Rencontres du Vietnam, Hanoi,
August 5-11 2004 | null | null | null | hep-ph | null | Lepton flavor violating Higgs boson decays (LFVHD) are studied in the context
of the Minimal Supersymmetric Standard Model (MSSM) enlarged with three right
handed neutrinos and their supersymmetric partners, and with the neutrino
masses being generated by the seesaw mechanism. We compute the partial widths
for these decays to one-loop order and analyze numerically the corresponding
branching ratios in terms of the MSSM and seesaw parameters. We analyze in
parallel the lepton flavor changing $\l_j\to l_i \gamma$ decays and explore the
maximum predicted rates for LFVHD, mainly for $H^0,A^0 \to \tau {\bar \mu}$
decays, by requiring compatibility with neutrino and $BR(\l_j\to l_i \gamma)$
data. We find LFVHD ratios of up to $10^{-5}$ in some regions of the
MSSM-seesaw parameter space.
| [
{
"created": "Wed, 3 Nov 2004 15:28:20 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Arganda",
"E.",
""
],
[
"Curiel",
"A. M.",
""
],
[
"Herrero",
"M. J.",
""
],
[
"Temes",
"D.",
""
]
] | Lepton flavor violating Higgs boson decays (LFVHD) are studied in the context of the Minimal Supersymmetric Standard Model (MSSM) enlarged with three right handed neutrinos and their supersymmetric partners, and with the neutrino masses being generated by the seesaw mechanism. We compute the partial widths for these decays to one-loop order and analyze numerically the corresponding branching ratios in terms of the MSSM and seesaw parameters. We analyze in parallel the lepton flavor changing $\l_j\to l_i \gamma$ decays and explore the maximum predicted rates for LFVHD, mainly for $H^0,A^0 \to \tau {\bar \mu}$ decays, by requiring compatibility with neutrino and $BR(\l_j\to l_i \gamma)$ data. We find LFVHD ratios of up to $10^{-5}$ in some regions of the MSSM-seesaw parameter space. |
hep-ph/0311003 | Kingman Cheung | Kingman Cheung (Nat. Tsing Hua Univ.) and Wai-Yee Keung (Illinois,
Chicago) | Belle J/psi+eta_c anomaly and a very light scalar boson | 10 pages, 5 figures | Phys.Rev.D69:094026,2004 | 10.1103/PhysRevD.69.094026 | null | hep-ph hep-ex | null | The large rate of the $J/\psi+\eta_c$ production observed by the Belle
collaboration has posed a serious challenge to our understanding of the
quarkonium. We examine a scenario that there exists a light scalar boson around
5 GeV, with an enhanced coupling solely to the charm quark. Such a scenario
would explain the Belle anomaly. It also predicts a significant increase in
$J/\psi$ plus open charm pair production. An immediate test for the scalar
boson is to look for a peak around 5 GeV in the recoil mass spectrum of
$J/\psi$, because the scalar boson can also be produced in association with the
$J/\psi$. Finally, we also point out that the process $e^+ e^- \to H \gamma$ is
sizable for observation.
| [
{
"created": "Sat, 1 Nov 2003 00:37:47 GMT",
"version": "v1"
}
] | 2009-09-01 | [
[
"Cheung",
"Kingman",
"",
"Nat. Tsing Hua Univ."
],
[
"Keung",
"Wai-Yee",
"",
"Illinois,\n Chicago"
]
] | The large rate of the $J/\psi+\eta_c$ production observed by the Belle collaboration has posed a serious challenge to our understanding of the quarkonium. We examine a scenario that there exists a light scalar boson around 5 GeV, with an enhanced coupling solely to the charm quark. Such a scenario would explain the Belle anomaly. It also predicts a significant increase in $J/\psi$ plus open charm pair production. An immediate test for the scalar boson is to look for a peak around 5 GeV in the recoil mass spectrum of $J/\psi$, because the scalar boson can also be produced in association with the $J/\psi$. Finally, we also point out that the process $e^+ e^- \to H \gamma$ is sizable for observation. |
1705.01488 | Anatoly Radyushkin | A. V. Radyushkin | Quasi-PDFs, momentum distributions and pseudo-PDFs | 6 pages, 3 figures, changes in text and references | Phys. Rev. D 96, 034025 (2017) | 10.1103/PhysRevD.96.034025 | JLAB-THY-17-2455 | hep-ph hep-lat nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We show that quasi-PDFs may be treated as hybrids of PDFs and primordial
rest-frame momentum distributions of partons. This results in a complicated
convolution nature of quasi-PDFs that necessitates using large $p_3 \sim 3$ GeV
momenta to get reasonably close to the PDF limit. As an alternative approach,
we propose to use pseudo-PDFs $P(x, z_3^2)$ that generalize the light-front
PDFs onto spacelike intervals and are related to Ioffe-time distributions $M
(\nu, z_3^2)$, the functions of the Ioffe time $\nu = p_3 z_3$ and the distance
parameter $z_3^2$ with respect to which it displays perturbative evolution for
small $z_3$. In this form, one may divide out the $z_3^2$ dependence coming
from the primordial rest-frame distribution and from the problematic factor due
to lattice renormalization of the gauge link. The $\nu$-dependence remains
intact and determines the shape of PDFs.
| [
{
"created": "Wed, 3 May 2017 15:50:53 GMT",
"version": "v1"
},
{
"created": "Fri, 9 Jun 2017 14:00:23 GMT",
"version": "v2"
},
{
"created": "Tue, 1 Aug 2017 23:26:50 GMT",
"version": "v3"
}
] | 2017-09-06 | [
[
"Radyushkin",
"A. V.",
""
]
] | We show that quasi-PDFs may be treated as hybrids of PDFs and primordial rest-frame momentum distributions of partons. This results in a complicated convolution nature of quasi-PDFs that necessitates using large $p_3 \sim 3$ GeV momenta to get reasonably close to the PDF limit. As an alternative approach, we propose to use pseudo-PDFs $P(x, z_3^2)$ that generalize the light-front PDFs onto spacelike intervals and are related to Ioffe-time distributions $M (\nu, z_3^2)$, the functions of the Ioffe time $\nu = p_3 z_3$ and the distance parameter $z_3^2$ with respect to which it displays perturbative evolution for small $z_3$. In this form, one may divide out the $z_3^2$ dependence coming from the primordial rest-frame distribution and from the problematic factor due to lattice renormalization of the gauge link. The $\nu$-dependence remains intact and determines the shape of PDFs. |
1802.04728 | Igor Krasnov | Igor Krasnov and Timofey Grigorin-Ryabov | Numerical estimate of minimal active-sterile neutrino mixing for sterile
neutrinos at GeV scale | 21 pages, 19 figures | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | Seesaw mechanism constrains from below mixing between active and sterile
neutrinos for fixed sterile neutrino masses. Signal events associated with
sterile neutrino decays inside a detector at fixed target experiment are
suppressed by the mixing angle to the power of four. Therefore sensitivity of
experiments such as SHiP and DUNE should take into account minimal possible
values of the mixing angles. We extend the previous study of this subject
arXiv:1312.2887 to a more general case of non-zero CP-violating phases in the
neutrino sector. Namely, we provide numerical estimate of minimal value of
mixing angles between active neutrinos and two sterile neutrinos with the third
sterile neutrino playing no noticeable role in the mixing. Thus we obtain a
sensitivity needed to fully explore the seesaw type I mechanism for sterile
neutrinos with masses below 2 GeV, and one undetectable sterile neutrino that
is relevant for the fixed-target experiments. Remarkably, we observe a strong
dependence of this result on the lightest active neutrino mass and the neutrino
mass hierarchy, not only on the values of CP-violating phases themselves. All
these effects sum up to push the limit of experimental confirmation of
sterile-active neutrino mixing by several orders of magnitude below the results
of arXiv:1312.2887 from $10^{-10}$ - $10^{-11}$ down to $10^{-12}$ and even to
$10^{-20}$ in parts of parameter space; nonzero CP-violating phases are
responsible for that.
| [
{
"created": "Tue, 13 Feb 2018 16:49:01 GMT",
"version": "v1"
},
{
"created": "Tue, 3 Jul 2018 09:50:45 GMT",
"version": "v2"
},
{
"created": "Wed, 3 Oct 2018 11:10:19 GMT",
"version": "v3"
},
{
"created": "Mon, 8 Oct 2018 13:59:47 GMT",
"version": "v4"
}
] | 2018-10-09 | [
[
"Krasnov",
"Igor",
""
],
[
"Grigorin-Ryabov",
"Timofey",
""
]
] | Seesaw mechanism constrains from below mixing between active and sterile neutrinos for fixed sterile neutrino masses. Signal events associated with sterile neutrino decays inside a detector at fixed target experiment are suppressed by the mixing angle to the power of four. Therefore sensitivity of experiments such as SHiP and DUNE should take into account minimal possible values of the mixing angles. We extend the previous study of this subject arXiv:1312.2887 to a more general case of non-zero CP-violating phases in the neutrino sector. Namely, we provide numerical estimate of minimal value of mixing angles between active neutrinos and two sterile neutrinos with the third sterile neutrino playing no noticeable role in the mixing. Thus we obtain a sensitivity needed to fully explore the seesaw type I mechanism for sterile neutrinos with masses below 2 GeV, and one undetectable sterile neutrino that is relevant for the fixed-target experiments. Remarkably, we observe a strong dependence of this result on the lightest active neutrino mass and the neutrino mass hierarchy, not only on the values of CP-violating phases themselves. All these effects sum up to push the limit of experimental confirmation of sterile-active neutrino mixing by several orders of magnitude below the results of arXiv:1312.2887 from $10^{-10}$ - $10^{-11}$ down to $10^{-12}$ and even to $10^{-20}$ in parts of parameter space; nonzero CP-violating phases are responsible for that. |
0911.0020 | Biagio Lucini | Biagio Lucini | Strongly Interacting Dynamics beyond the Standard Model on a Spacetime
Lattice | Minor corrections and clarifications of some points, conclusions
unchanged | Phil.Trans.Roy.Soc.Lond.A368:3657-3670,2010 | 10.1098/rsta.2010.0030 | null | hep-ph hep-lat hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Strong theoretical arguments suggest that the Higgs sector of the Standard
Model of the Electroweak interactions is an effective low-energy theory, with a
more fundamental theory that is expected to emerge at an energy scale of the
order of the TeV. One possibility is that the more fundamental theory be
strongly interacting and the Higgs sector be given by the low-energy dynamics
of the underlying theory. We review recent works aimed to determining
observable quantities by numerical simulations of strongly interacting theories
proposed in the literature for explaining the Electroweak symmetry breaking
mechanism. These investigations are based on Monte Carlo simulations of the
theory formulated on a spacetime lattice. We focus on the so-called Minimal
Walking Technicolour scenario, a SU(2) gauge theory with two flavours of
fermions in the adjoint representation. The emerging picture is that this
theory has an infrared fixed point that dominates the large distance physics.
We shall discuss the first numerical determinations of quantities of
phenomenological interest for this theory and analyse future directions of
quantitative studies of strongly interacting beyond the Standard Model theories
with Lattice techniques. In particular, we report on a finite size scaling
determination of the chiral condensate anomalous dimension $\gamma$, for which
we find $0.05 \le \gamma \le 0.25$.
| [
{
"created": "Mon, 2 Nov 2009 16:37:30 GMT",
"version": "v1"
},
{
"created": "Wed, 27 Jan 2010 17:33:58 GMT",
"version": "v2"
}
] | 2011-05-19 | [
[
"Lucini",
"Biagio",
""
]
] | Strong theoretical arguments suggest that the Higgs sector of the Standard Model of the Electroweak interactions is an effective low-energy theory, with a more fundamental theory that is expected to emerge at an energy scale of the order of the TeV. One possibility is that the more fundamental theory be strongly interacting and the Higgs sector be given by the low-energy dynamics of the underlying theory. We review recent works aimed to determining observable quantities by numerical simulations of strongly interacting theories proposed in the literature for explaining the Electroweak symmetry breaking mechanism. These investigations are based on Monte Carlo simulations of the theory formulated on a spacetime lattice. We focus on the so-called Minimal Walking Technicolour scenario, a SU(2) gauge theory with two flavours of fermions in the adjoint representation. The emerging picture is that this theory has an infrared fixed point that dominates the large distance physics. We shall discuss the first numerical determinations of quantities of phenomenological interest for this theory and analyse future directions of quantitative studies of strongly interacting beyond the Standard Model theories with Lattice techniques. In particular, we report on a finite size scaling determination of the chiral condensate anomalous dimension $\gamma$, for which we find $0.05 \le \gamma \le 0.25$. |
hep-ph/9906386 | Sergo Gerasimov | S.B.Gerasimov | Electroweak moments of baryons and hidden strangeness of the nucleon | LaTex, 8 pages, no figures; talk given at the 2nd ELFE Workshop on
Hadronic Physics, Saint Malo, France, 23-27 September, 1996; the abstract is
slightly enlarged compared with the journal version | Chin.J.Phys.34:848,1996 | null | null | hep-ph | null | The phenomenological sum-rule-based approach is used to discuss the quark
composition dependence of some static electroweak characteristics of
baryons.The role of nonvalence degrees of freedom (the sea partons and/or
peripheral meson currents) is shown to be important to select and make use of
the relevant symmetry parametrization of baryon observables.The implications of
the baryon magnetic moment analysis for estimation of the $\Delta$q values of
the spin-dependent DIS on nucleons, the contribution of hidden strangeness to
the nucleon magnetic moment and to the quark-line-rule violating $\phi \pi$ -
production in antinucleon-nucleon annihilation reaction are presented.
| [
{
"created": "Wed, 16 Jun 1999 09:55:55 GMT",
"version": "v1"
}
] | 2011-04-15 | [
[
"Gerasimov",
"S. B.",
""
]
] | The phenomenological sum-rule-based approach is used to discuss the quark composition dependence of some static electroweak characteristics of baryons.The role of nonvalence degrees of freedom (the sea partons and/or peripheral meson currents) is shown to be important to select and make use of the relevant symmetry parametrization of baryon observables.The implications of the baryon magnetic moment analysis for estimation of the $\Delta$q values of the spin-dependent DIS on nucleons, the contribution of hidden strangeness to the nucleon magnetic moment and to the quark-line-rule violating $\phi \pi$ - production in antinucleon-nucleon annihilation reaction are presented. |
0908.0948 | Gerald V. Dunne | Gerald V. Dunne, Holger Gies, and Ralf Sch\"utzhold | Catalysis of Schwinger Vacuum Pair Production | 4 pages, 2 figures; v2 clarifications and references added | Phys.Rev.D80:111301,2009 | 10.1103/PhysRevD.80.111301 | null | hep-ph hep-th quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose a new catalysis mechanism for non-perturbative vacuum
electron-positron pair production, by superimposing a plane-wave X-ray probe
beam with a strongly focused optical laser pulse, such as is planned at the
Extreme Light Infrastructure (ELI) facility. We compute the absorption
coefficient arising from vacuum polarization effects for photons below
threshold in a strong electric field. This set-up should facilitate the (first)
observation of this non-perturbative QED effect with planned light sources such
as ELI yielding an envisioned intensity of order 10^{26}W/cm^2.
| [
{
"created": "Thu, 6 Aug 2009 20:07:04 GMT",
"version": "v1"
},
{
"created": "Mon, 26 Oct 2009 20:27:00 GMT",
"version": "v2"
}
] | 2010-11-11 | [
[
"Dunne",
"Gerald V.",
""
],
[
"Gies",
"Holger",
""
],
[
"Schützhold",
"Ralf",
""
]
] | We propose a new catalysis mechanism for non-perturbative vacuum electron-positron pair production, by superimposing a plane-wave X-ray probe beam with a strongly focused optical laser pulse, such as is planned at the Extreme Light Infrastructure (ELI) facility. We compute the absorption coefficient arising from vacuum polarization effects for photons below threshold in a strong electric field. This set-up should facilitate the (first) observation of this non-perturbative QED effect with planned light sources such as ELI yielding an envisioned intensity of order 10^{26}W/cm^2. |
1204.4588 | Chaehyun Yu | P. Ko, Yuji Omura, Chaehyun Yu (KIAS) | A Resolution of the Flavor Problem of Two Higgs Doublet Models with an
Extra U(1)_H Symmetry for Higgs Flavor | 7 pages, version published in Phys. Lett. B | Phys. Lett. B 717 (2012) 202 | 10.1016/j.physletb.2012.09.019 | KIAS-PREPRINT-P11063 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose to implement the Natural Flavor Conservation criterion in the two
Higgs doublet model (2HDM) to an extra U(1)_H gauge symmetry for Higgs flavor,
assuming two Higgs doublets carry different U(1)_H charges. Then one can easily
avoid the tree level FCNC from neutral Higgs mediations using local gauge
symmetries, instead of softly broken ad hoc Z_2 symmetry, and the pseudoscalar
boson could be eaten by extra Z_H boson. Imposing the anomaly cancellation, we
find that the U(1)_H in the Type-II and Type-IV 2HDM's become leptophobic and
leptophilic, respectively. For the Type-I case, U(1)_H depends on two
parameters, and some simple cases include U(1)_H = U(1)_{B-L}, U(1)_R, or
U(1)_Y. We sketch qualitative phenomenology of these models.
| [
{
"created": "Fri, 20 Apr 2012 11:35:46 GMT",
"version": "v1"
},
{
"created": "Thu, 20 Sep 2012 18:54:59 GMT",
"version": "v2"
}
] | 2015-06-04 | [
[
"Ko",
"P.",
"",
"KIAS"
],
[
"Omura",
"Yuji",
"",
"KIAS"
],
[
"Yu",
"Chaehyun",
"",
"KIAS"
]
] | We propose to implement the Natural Flavor Conservation criterion in the two Higgs doublet model (2HDM) to an extra U(1)_H gauge symmetry for Higgs flavor, assuming two Higgs doublets carry different U(1)_H charges. Then one can easily avoid the tree level FCNC from neutral Higgs mediations using local gauge symmetries, instead of softly broken ad hoc Z_2 symmetry, and the pseudoscalar boson could be eaten by extra Z_H boson. Imposing the anomaly cancellation, we find that the U(1)_H in the Type-II and Type-IV 2HDM's become leptophobic and leptophilic, respectively. For the Type-I case, U(1)_H depends on two parameters, and some simple cases include U(1)_H = U(1)_{B-L}, U(1)_R, or U(1)_Y. We sketch qualitative phenomenology of these models. |
0911.5073 | Mansoor Ur Rehman | Nobuchika Okada, Mansoor Ur Rehman and Qaisar Shafi | Running Standard Model Inflation And Type I Seesaw | 12 pages, 6 figures | null | null | null | hep-ph astro-ph.HE gr-qc | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Several authors have recently argued that a satisfactory inflationary
scenario can be implemented in the Standard Model (SM) by introducing a strong
non-minimal coupling of the Higgs doublet to gravity. It is shown here that
type I seesaw physics containing right handed neutrinos at intermediate scales
can have a significant impact on the inflationary predictions of these models.
For one such model, values of the scalar spectral index lower than the tree
level prediction of 0.968 are realized for plausible values of the seesaw
parameters and a SM Higgs boson mass close to 130 GeV. A precise measurement of
n_s by PLANCK, as well as measurement of the Higgs boson mass by LHC should
provide stringent tests of this SM based inflationary scenario supplemented by
type I seesaw physics.
| [
{
"created": "Thu, 26 Nov 2009 12:41:56 GMT",
"version": "v1"
}
] | 2009-12-02 | [
[
"Okada",
"Nobuchika",
""
],
[
"Rehman",
"Mansoor Ur",
""
],
[
"Shafi",
"Qaisar",
""
]
] | Several authors have recently argued that a satisfactory inflationary scenario can be implemented in the Standard Model (SM) by introducing a strong non-minimal coupling of the Higgs doublet to gravity. It is shown here that type I seesaw physics containing right handed neutrinos at intermediate scales can have a significant impact on the inflationary predictions of these models. For one such model, values of the scalar spectral index lower than the tree level prediction of 0.968 are realized for plausible values of the seesaw parameters and a SM Higgs boson mass close to 130 GeV. A precise measurement of n_s by PLANCK, as well as measurement of the Higgs boson mass by LHC should provide stringent tests of this SM based inflationary scenario supplemented by type I seesaw physics. |
1907.10765 | Juan Carlos G\'omez Izquierdo | J. D. Garc\'ia-Aguilar and Juan Carlos G\'omez-Izquierdo | A comparative study between the modified Fritzsch and nearest neighbor
interaction textures | 15 pages, 8 figures. Minor chances, references and some comments
added | null | 10.1142/S0217751X19502245 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | From mass textures point of view, we present a comparative study of the
$\mathbf{S}_{3}$ flavor symmetry in the left-right symmetry model (LRSM) and
the baryon minus lepton model (BLM) taking into account their predictions on
the CKM mixing matrix. To do this, we recover the already studied quark mass
matrix, that comes from some published papers, and under certain strong
assumption, one can show that there are predictive scenarios in the LRSM and
BLM where the modified Fritzsch and nearest neighbor interaction (NNI) textures
drive respectively the quark mixings. As main result, the CKM mixing matrix is
in good agreement with the last experimental data in the flavored BLM model.
| [
{
"created": "Wed, 24 Jul 2019 22:44:32 GMT",
"version": "v1"
},
{
"created": "Thu, 19 Sep 2019 17:02:26 GMT",
"version": "v2"
}
] | 2020-01-29 | [
[
"García-Aguilar",
"J. D.",
""
],
[
"Gómez-Izquierdo",
"Juan Carlos",
""
]
] | From mass textures point of view, we present a comparative study of the $\mathbf{S}_{3}$ flavor symmetry in the left-right symmetry model (LRSM) and the baryon minus lepton model (BLM) taking into account their predictions on the CKM mixing matrix. To do this, we recover the already studied quark mass matrix, that comes from some published papers, and under certain strong assumption, one can show that there are predictive scenarios in the LRSM and BLM where the modified Fritzsch and nearest neighbor interaction (NNI) textures drive respectively the quark mixings. As main result, the CKM mixing matrix is in good agreement with the last experimental data in the flavored BLM model. |
hep-ph/9802412 | A. Khodjamirian | A. Khodjamirian, R. R\"uckl, C.W. Winhart | The Scalar $B\to \pi$ and $D \to \pi$ Form Factors in QCD | 19 pages, 10 figures, Latex, epsfig | Phys.Rev. D58 (1998) 054013 | 10.1103/PhysRevD.58.054013 | CERN-TH/98-58, WUE-ITP-98-006 | hep-ph | null | QCD sum rules on the light-cone are derived for the sum $f^+ + f^-$ of the
$B\to \pi$ and $D\to \pi$ form factors taking into account contributions up to
twist four. Combining the results with the corresponding $f^+$ form factors
calculated previously by the same method, we obtain the scalar form factors
$f^0$. Our sum rule predictions are compared with lattice results,
current-algebra constraints, and quark-model calculations. Furthermore, we
calculate decay distributions and the integrated width for the semileptonic
decay $B \to \pi \bar{\tau}\nu_\tau$ which is sensitive to $f^0$. Finally, the
dependence of the sum rules on the heavy quark mass and the asymptotic scaling
laws are discussed.
| [
{
"created": "Wed, 25 Feb 1998 00:21:41 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Khodjamirian",
"A.",
""
],
[
"Rückl",
"R.",
""
],
[
"Winhart",
"C. W.",
""
]
] | QCD sum rules on the light-cone are derived for the sum $f^+ + f^-$ of the $B\to \pi$ and $D\to \pi$ form factors taking into account contributions up to twist four. Combining the results with the corresponding $f^+$ form factors calculated previously by the same method, we obtain the scalar form factors $f^0$. Our sum rule predictions are compared with lattice results, current-algebra constraints, and quark-model calculations. Furthermore, we calculate decay distributions and the integrated width for the semileptonic decay $B \to \pi \bar{\tau}\nu_\tau$ which is sensitive to $f^0$. Finally, the dependence of the sum rules on the heavy quark mass and the asymptotic scaling laws are discussed. |
hep-ph/9910236 | Marco Ciuchini | M. Ciuchini, E. Franco, L. Giusti, V. Lubicz and G. Martinelli | Combined analysis of the unitarity triangle and CP violation in the
Standard Model | LaTeX2e, 31 pages. 5 eps figures included | Nucl.Phys.B573:201-222,2000 | 10.1016/S0550-3213(99)00807-X | BUHEP-99-24, RM3-TH/99-9, ROME 99/1267 | hep-ph | null | We perform a combined analysis of the unitarity triangle and of the CP
violating parameter epsilon'/epsilon using the most recent determination of the
relevant experimental data and, whenever possible, hadronic matrix elements
from lattice QCD. We discuss the role of the main non-perturbative parameters
and make a comparison with other recent analyses. We use lattice results for
the matrix element of Q_8 obtained without reference to the strange quark mass.
Since a reliable lattice determination of the matrix element of Q_6 is still
missing, the theoretical predictions for epsilon'/epsilon suffer from large
uncertainties. By evaluating this matrix element with the vacuum-saturation
approximation, we typically find as central value epsilon'/epsilon = (4 - 7) x
10^(-4). We conclude that the experimental data suggest large deviation of the
value of the matrix element of Q_6 from the vacuum-saturation approximation,
possibly due to penguin contractions.
| [
{
"created": "Tue, 5 Oct 1999 10:50:07 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Ciuchini",
"M.",
""
],
[
"Franco",
"E.",
""
],
[
"Giusti",
"L.",
""
],
[
"Lubicz",
"V.",
""
],
[
"Martinelli",
"G.",
""
]
] | We perform a combined analysis of the unitarity triangle and of the CP violating parameter epsilon'/epsilon using the most recent determination of the relevant experimental data and, whenever possible, hadronic matrix elements from lattice QCD. We discuss the role of the main non-perturbative parameters and make a comparison with other recent analyses. We use lattice results for the matrix element of Q_8 obtained without reference to the strange quark mass. Since a reliable lattice determination of the matrix element of Q_6 is still missing, the theoretical predictions for epsilon'/epsilon suffer from large uncertainties. By evaluating this matrix element with the vacuum-saturation approximation, we typically find as central value epsilon'/epsilon = (4 - 7) x 10^(-4). We conclude that the experimental data suggest large deviation of the value of the matrix element of Q_6 from the vacuum-saturation approximation, possibly due to penguin contractions. |
hep-ph/9412295 | null | Stephan Narison (Univ. Montpellier) | Alpha_s from Tau Decays | Due to some requests, this paper replaces file corrupted by e-mail
transfer: Talk given at the third Workshop on Tau Lepton Physics, Montreux,
Switzerland, September 1994. published in Nucl.Phys. B, proceedings
supplement, 40 (1995) 47-58 | Nucl.Phys.Proc.Suppl. 40 (1995) 47-58 | 10.1016/0920-5632(95)00129-W | CERN-TH 7506/94 | hep-ph | null | We review the present status in the determination of the $accurate$ value of
$\alpha_s$ from $\tau$-decays, where we discuss in detail the different sources
of theoretical errors.
| [
{
"created": "Wed, 14 Dec 1994 11:45:16 GMT",
"version": "v1"
},
{
"created": "Mon, 16 Oct 1995 11:58:00 GMT",
"version": "v2"
}
] | 2009-10-28 | [
[
"Narison",
"Stephan",
"",
"Univ. Montpellier"
]
] | We review the present status in the determination of the $accurate$ value of $\alpha_s$ from $\tau$-decays, where we discuss in detail the different sources of theoretical errors. |
hep-ph/0103148 | Shinji Tsujikawa | Shinji Tsujikawa, Hiroki Yajima (Waseda University) | Massive fermion production in nonsingular superstring cosmology | 5 pages, 3 figures | Phys.Rev. D64 (2001) 023519 | 10.1103/PhysRevD.64.023519 | WU-AP/124/01 | hep-ph astro-ph gr-qc hep-th | null | We study massive spin-1/2 fermion production in nonsingular superstring
cosmology, taking into account one-loop quantum corrections to a superstring
effective action with dilaton and modulus fields. While no creation occurs in
the massless limit, massive fermions can be produced by the existence of a
time-dependent frequency. Due to the increase of the Hubble expansion rate
during the modulus-driven phase, the occupation of number of fermions continues
to grow until the point of the graceful exit, after which fermion creation
ceases with the decrease of the Hubble rate.
| [
{
"created": "Wed, 14 Mar 2001 06:35:14 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Tsujikawa",
"Shinji",
"",
"Waseda University"
],
[
"Yajima",
"Hiroki",
"",
"Waseda University"
]
] | We study massive spin-1/2 fermion production in nonsingular superstring cosmology, taking into account one-loop quantum corrections to a superstring effective action with dilaton and modulus fields. While no creation occurs in the massless limit, massive fermions can be produced by the existence of a time-dependent frequency. Due to the increase of the Hubble expansion rate during the modulus-driven phase, the occupation of number of fermions continues to grow until the point of the graceful exit, after which fermion creation ceases with the decrease of the Hubble rate. |
1103.4882 | Carlos Louren\c{c}o | Pietro Faccioli, Carlos Lourenco, Joao Seixas, Hermine K. Woehri | Determination of chi_c and chi_b polarizations from dilepton angular
distributions in radiative decays | Submitted to Phys Rev D | Phys.Rev.D83:096001,2011 | 10.1103/PhysRevD.83.096001 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The angular distributions of the decay products in the successive decays
chi_c (chi_b) to J/psi (Upsilon) gamma and J/psi (Upsilon) to l+l- are
calculated as a function of the angular momentum composition of the decaying
chi meson and of the multipole structure of the photon radiation, using a
formalism independent of production mechanisms and polarization frames. The
polarizations of the chi states produced in high energy collisions can be
derived from the dilepton decay distributions of the daughter J/psi or Upsilon
mesons, with a reduced dependence on the details of the photon reconstruction
or simulation. Moreover, this method eliminates the dependence of the
polarization measurement on the actual details of the multipole structure of
the radiative transition. Problematic points in previous calculations of the
chi_c decay angular distributions are identified and clarified.
| [
{
"created": "Thu, 24 Mar 2011 22:58:15 GMT",
"version": "v1"
}
] | 2011-05-12 | [
[
"Faccioli",
"Pietro",
""
],
[
"Lourenco",
"Carlos",
""
],
[
"Seixas",
"Joao",
""
],
[
"Woehri",
"Hermine K.",
""
]
] | The angular distributions of the decay products in the successive decays chi_c (chi_b) to J/psi (Upsilon) gamma and J/psi (Upsilon) to l+l- are calculated as a function of the angular momentum composition of the decaying chi meson and of the multipole structure of the photon radiation, using a formalism independent of production mechanisms and polarization frames. The polarizations of the chi states produced in high energy collisions can be derived from the dilepton decay distributions of the daughter J/psi or Upsilon mesons, with a reduced dependence on the details of the photon reconstruction or simulation. Moreover, this method eliminates the dependence of the polarization measurement on the actual details of the multipole structure of the radiative transition. Problematic points in previous calculations of the chi_c decay angular distributions are identified and clarified. |
1008.1593 | S. Descotes-Genon | A. Lenz (U. Dortmund), U. Nierste (U. Regensburg and KIT Karlsruhe),
J. Charles (CPT Marseille), S. Descotes-Genon (LPT Orsay), A. Jantsch (MPI
Munchen), C. Kaufhold (LAPP Annecy), H. Lacker (Humboldt U. Berlin), S.
Monteil and V. Niess (LPC Clermont), S. T'Jampens (LAPP Annecy) | Anatomy of New Physics in B-Bbar mixing | 82 pages. Published version | Phys.Rev.D83:036004,2011 | 10.1103/PhysRevD.83.036004 | HU-EP-10/43, TTP10-33, DO-TH 10/05, SFB/CPP-10-68, LPT-ORSAY/10-59,
CPT-P040-2010, | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We analyse three different New Physics scenarios for Delta F=2
flavour-changing neutral currents in the quark sector in the light of recent
data on neutral-meson mixing. We parametrise generic New Physics contributions
to B_q-Bbar_q mixing (q=d,s), in terms of one complex quantity Delta_q, while
three parameters Delta_K^tt, Delta_K^ct and Delta_K^cc are needed to describe
K-Kbar mixing. In Scenario I, we consider uncorrelated New Physics
contributions in the B_d, B_s, and K sectors. In this scenario, it is only
possible to constrain the parameters Delta_d and Delta_s whereas there are no
non-trivial constraints on the kaon parameters. In Scenario II, we study the
case of Minimal Flavour Violation (MFV) and small bottom Yukawa coupling and
Scenario III is the generic MFV case with large bottom Yukawa couplings. Our
quantitative analyses consist of global CKM fits within the Rfit frequentist
statistical approach, determining the Standard Model parameters and the new
physics parameters of the studied scenarios simultaneously. We find that the
recent measurements indicating discrepancies with the Standard Model are well
accomodated in Scenarios I and III with new mixing phases, with a slight
preference for Scenario I that permits different new CP phases in the B_d and
B_s systems. Within our statistical framework, we find evidence of New Physics
in both B_d and B_s systems. The Standard-Model hypothesis Delta_d=Delta_s=1 is
disfavoured with p-values of 3.6 sigma and 3.3 sigma in Scenarios I and III,
respectively. We also present an exhaustive list of numerical predictions in
each scenario. In particular, we predict the CP phase in B_s -> J psi phi and
the difference between the B_s and B_d semileptonic asymmetries, which will be
both measured by the LHCb experiment.
| [
{
"created": "Mon, 9 Aug 2010 20:32:50 GMT",
"version": "v1"
},
{
"created": "Mon, 15 Nov 2010 13:16:18 GMT",
"version": "v2"
},
{
"created": "Tue, 1 Mar 2011 21:35:02 GMT",
"version": "v3"
}
] | 2011-03-03 | [
[
"Lenz",
"A.",
"",
"U. Dortmund"
],
[
"Nierste",
"U.",
"",
"U. Regensburg and KIT Karlsruhe"
],
[
"Charles",
"J.",
"",
"CPT Marseille"
],
[
"Descotes-Genon",
"S.",
"",
"LPT Orsay"
],
[
"Jantsch",
"A.",
"",
"MPI\n Munch... | We analyse three different New Physics scenarios for Delta F=2 flavour-changing neutral currents in the quark sector in the light of recent data on neutral-meson mixing. We parametrise generic New Physics contributions to B_q-Bbar_q mixing (q=d,s), in terms of one complex quantity Delta_q, while three parameters Delta_K^tt, Delta_K^ct and Delta_K^cc are needed to describe K-Kbar mixing. In Scenario I, we consider uncorrelated New Physics contributions in the B_d, B_s, and K sectors. In this scenario, it is only possible to constrain the parameters Delta_d and Delta_s whereas there are no non-trivial constraints on the kaon parameters. In Scenario II, we study the case of Minimal Flavour Violation (MFV) and small bottom Yukawa coupling and Scenario III is the generic MFV case with large bottom Yukawa couplings. Our quantitative analyses consist of global CKM fits within the Rfit frequentist statistical approach, determining the Standard Model parameters and the new physics parameters of the studied scenarios simultaneously. We find that the recent measurements indicating discrepancies with the Standard Model are well accomodated in Scenarios I and III with new mixing phases, with a slight preference for Scenario I that permits different new CP phases in the B_d and B_s systems. Within our statistical framework, we find evidence of New Physics in both B_d and B_s systems. The Standard-Model hypothesis Delta_d=Delta_s=1 is disfavoured with p-values of 3.6 sigma and 3.3 sigma in Scenarios I and III, respectively. We also present an exhaustive list of numerical predictions in each scenario. In particular, we predict the CP phase in B_s -> J psi phi and the difference between the B_s and B_d semileptonic asymmetries, which will be both measured by the LHCb experiment. |
1203.4129 | Antoni Szczurek | Wolfgang Sch\"afer and Antoni Szczurek | Production of two $c \bar c$ pairs in gluon-gluon scattering in high
energy proton-proton collisions | 17 pages, 11 figures | null | 10.1103/PhysRevD.85.094029 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We calculate cross sections for $g g \to Q \bar Q Q \bar Q$ in the
high-energy approximation in the mixed (longitudinal momentum fraction, impact
parameter) and momentum space representations. Besides the total cross section
as a function of subsystem energy also differential distributions (in quark
rapidity, transverse momentum, $Q Q$, $Q \bar Q$ invariant mass) are presented.
The elementary cross section is used to calculate production of $(c \bar c) (c
\bar c)$ in single-parton scattering (SPS) in proton-proton collisions. We
present integrated cross section as a function of proton-proton center of mass
energy as well as differential distribution in $M_{(c \bar c)(c \bar c)}$. The
results are compared with corresponding results for double-parton scattering
(DPS) discussed recently in the literature. We find that the considered SPS
contribution to $(c \bar c)(c \bar c)$ production is at high energy ($\sqrt{s}
>$ 5 TeV) much smaller than that for DPS contribution.
| [
{
"created": "Mon, 19 Mar 2012 15:14:30 GMT",
"version": "v1"
}
] | 2013-05-30 | [
[
"Schäfer",
"Wolfgang",
""
],
[
"Szczurek",
"Antoni",
""
]
] | We calculate cross sections for $g g \to Q \bar Q Q \bar Q$ in the high-energy approximation in the mixed (longitudinal momentum fraction, impact parameter) and momentum space representations. Besides the total cross section as a function of subsystem energy also differential distributions (in quark rapidity, transverse momentum, $Q Q$, $Q \bar Q$ invariant mass) are presented. The elementary cross section is used to calculate production of $(c \bar c) (c \bar c)$ in single-parton scattering (SPS) in proton-proton collisions. We present integrated cross section as a function of proton-proton center of mass energy as well as differential distribution in $M_{(c \bar c)(c \bar c)}$. The results are compared with corresponding results for double-parton scattering (DPS) discussed recently in the literature. We find that the considered SPS contribution to $(c \bar c)(c \bar c)$ production is at high energy ($\sqrt{s} >$ 5 TeV) much smaller than that for DPS contribution. |
hep-ph/9505258 | Jeonghyeon Song | Chung Wook Kim and JeongHyeon Song ( Johns Hopkins Univ.) | A Proposed Scale-Dependent Cosmology for the Inhomogeneous Cosmology | 28 pages, RevTex, no figures, to be run twice | Int.J.Mod.Phys. D5 (1996) 293-312 | 10.1142/S0218271896000205 | JHU-TIPAC 95016 | hep-ph astro-ph gr-qc | null | We propose a scale-dependent cosmology in which the Robertson--Walker metric
and the Einstein equation are modified in such a way that $\Omega_0$, $H_0$ and
the age of the Universe all become scale-dependent. Its implications on the
observational cosmology and possible modifications of the standard Friedmann
cosmology are discussed. For example, the age of the Universe in this model is
longer than that of the standard model.
| [
{
"created": "Mon, 8 May 1995 20:21:10 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Kim",
"Chung Wook",
"",
"Johns Hopkins Univ."
],
[
"Song",
"JeongHyeon",
"",
"Johns Hopkins Univ."
]
] | We propose a scale-dependent cosmology in which the Robertson--Walker metric and the Einstein equation are modified in such a way that $\Omega_0$, $H_0$ and the age of the Universe all become scale-dependent. Its implications on the observational cosmology and possible modifications of the standard Friedmann cosmology are discussed. For example, the age of the Universe in this model is longer than that of the standard model. |
1709.07887 | Mariel Estevez | Ezequiel Alvarez, Leandro Da Rold, Mariel Estevez, Jernej F. Kamenik | Measuring $|V_{td}|$ at LHC | 10 pages, 6 figures | Phys. Rev. D 97, 033002 (2018) | 10.1103/PhysRevD.97.033002 | ICAS 030/17 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose a direct measurement of the CKM element $V_{td}$ at the LHC.
Taking profit of the imbalance between $d$ and $\bar d$ quark content in the
proton, we show that a non-zero $V_{td}$ induces a charge asymmetry in the $tW$
associated production. The main backgrounds to this process, $t\bar t$
production, and $tW$ associated production mediated by $V_{tb}$, give charge
symmetric contributions at leading order in QCD. Therefore, using specific
kinematic features of the signal, we construct a charge asymmetry in the
di-lepton final state which, due also to a reduction of systematic
uncertainties in the asymmetry, is potentially sensitive to $V_{td}$ suppressed
effects. In particular, using signal and background simulations up to detector
level, we show that this new observable could improve the current direct upper
bound on $|V_{td}|$ already with existing LHC data. We also project that
$|V_{td}|$ values down to $\sim 10$ times the Standard Model prediction could
be probed in the high luminosity phase of the LHC.
| [
{
"created": "Fri, 22 Sep 2017 18:00:23 GMT",
"version": "v1"
}
] | 2018-02-21 | [
[
"Alvarez",
"Ezequiel",
""
],
[
"Da Rold",
"Leandro",
""
],
[
"Estevez",
"Mariel",
""
],
[
"Kamenik",
"Jernej F.",
""
]
] | We propose a direct measurement of the CKM element $V_{td}$ at the LHC. Taking profit of the imbalance between $d$ and $\bar d$ quark content in the proton, we show that a non-zero $V_{td}$ induces a charge asymmetry in the $tW$ associated production. The main backgrounds to this process, $t\bar t$ production, and $tW$ associated production mediated by $V_{tb}$, give charge symmetric contributions at leading order in QCD. Therefore, using specific kinematic features of the signal, we construct a charge asymmetry in the di-lepton final state which, due also to a reduction of systematic uncertainties in the asymmetry, is potentially sensitive to $V_{td}$ suppressed effects. In particular, using signal and background simulations up to detector level, we show that this new observable could improve the current direct upper bound on $|V_{td}|$ already with existing LHC data. We also project that $|V_{td}|$ values down to $\sim 10$ times the Standard Model prediction could be probed in the high luminosity phase of the LHC. |
hep-ph/0109098 | Haijun Gong | Haijun Gong, Junfeng Sun, Dongsheng Du | Analysis of D_s-> phi pi beyond naive factorization | 11 pages, 5 figures, LaTex | High Energy Phys.Nucl.Phys.26:665-671,2002 | null | null | hep-ph | null | We analyze the decay $D_s\to \phi \pi$ with QCD factorization in the heavy
quark limit. The nonfactorizable contributions, including hard spectator
contribution are discussed and numerical results are presented. Our predictions
on the branching ratio of the decay are in agreement with the experiment. We
also use a pure phenomenological method to estimate the branching ratio for
$D_s\to \phi\pi$ with the existed $D^0\to K^{*}\pi$ data.
| [
{
"created": "Wed, 12 Sep 2001 03:54:56 GMT",
"version": "v1"
}
] | 2010-02-23 | [
[
"Gong",
"Haijun",
""
],
[
"Sun",
"Junfeng",
""
],
[
"Du",
"Dongsheng",
""
]
] | We analyze the decay $D_s\to \phi \pi$ with QCD factorization in the heavy quark limit. The nonfactorizable contributions, including hard spectator contribution are discussed and numerical results are presented. Our predictions on the branching ratio of the decay are in agreement with the experiment. We also use a pure phenomenological method to estimate the branching ratio for $D_s\to \phi\pi$ with the existed $D^0\to K^{*}\pi$ data. |
hep-ph/9804463 | Chi-Sing Lam | C.S. Lam (McGill University) | QCD Phase Shifts and Rising Total Cross-Sections | 13 pages with three postscript figures, composed in the Revtex
preprint format. Some misprints of a previous version have been corrected
here | null | null | null | hep-ph hep-th | null | An attempt is made in QCD to explain the growth of total cross-sections with
energy, without violating the Froissart bound. This is achieved by computing
the phase shifts of elastic scatterings of partons rather than their
amplitudes. To render that possible a general formalism of phase-shifts in QCD
is developed. Computed to two-loop order, agreements with hadronic and
virtual-photon total cross-sections are quite satisfactory. Predications for
the slower rate of growth at higher energies are also presented.
| [
{
"created": "Thu, 30 Apr 1998 19:18:19 GMT",
"version": "v1"
},
{
"created": "Mon, 4 May 1998 18:33:40 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Lam",
"C. S.",
"",
"McGill University"
]
] | An attempt is made in QCD to explain the growth of total cross-sections with energy, without violating the Froissart bound. This is achieved by computing the phase shifts of elastic scatterings of partons rather than their amplitudes. To render that possible a general formalism of phase-shifts in QCD is developed. Computed to two-loop order, agreements with hadronic and virtual-photon total cross-sections are quite satisfactory. Predications for the slower rate of growth at higher energies are also presented. |
hep-ph/9904492 | Yuly Shabelsky | Yu.M. Shabelski (Petersburg Nuclear Physics Institute, Gatchina,
St.Petersburg, Russia) | The Role of Incident Parton Transverse Momenta in Heavy Quark
Hadroproduction | 10 pages, LaTeX, 6 figures, epsfig.sty. Talk, given at HERA Monte
Carlo Workshop, 27-30 April 1998, DESY, Hamburg | null | null | null | hep-ph | null | The conventional NLO parton model is enough for the description of total
cross sections and one-particle distributions. In the case of two-particle
correlations, the collinear approximation has failed, and it is necessary to
account for the transverse momenta of initial partons. The different
possibilities to do this are discussed.
| [
{
"created": "Thu, 29 Apr 1999 13:48:21 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Shabelski",
"Yu. M.",
"",
"Petersburg Nuclear Physics Institute, Gatchina,\n St.Petersburg, Russia"
]
] | The conventional NLO parton model is enough for the description of total cross sections and one-particle distributions. In the case of two-particle correlations, the collinear approximation has failed, and it is necessary to account for the transverse momenta of initial partons. The different possibilities to do this are discussed. |
0902.3512 | Tobias Huber | G. Heinrich, T. Huber, D. A. Kosower, V. A. Smirnov | Nine-Propagator Master Integrals for Massless Three-Loop Form Factors | 15 pages, 2 figures. Minor modifications and reference added. Matches
published version | Phys.Lett.B678:359-366,2009 | 10.1016/j.physletb.2009.06.038 | PITHA-09/07, IPPP/09/09, DCPT/09/18, TTP09-06, SFB/CPP-09-21,
Saclay-IPhT-T09/021 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We complete the calculation of master integrals for massless three-loop form
factors by computing the previously-unknown three diagrams with nine
propagators in dimensional regularisation. Each of the integrals yields a
six-fold Mellin-Barnes representation which we use to compute the coefficients
of the Laurent expansion in epsilon. Using Riemann zeta functions of up to
weight six, we give fully analytic results for one integral; for a second,
analytic results for all but the finite term; for the third, analytic results
for all but the last two coefficients in the Laurent expansion. The remaining
coefficients are given numerically to sufficiently high accuracy for
phenomenological applications.
| [
{
"created": "Fri, 20 Feb 2009 07:48:54 GMT",
"version": "v1"
},
{
"created": "Tue, 7 Jul 2009 07:59:12 GMT",
"version": "v2"
}
] | 2009-07-24 | [
[
"Heinrich",
"G.",
""
],
[
"Huber",
"T.",
""
],
[
"Kosower",
"D. A.",
""
],
[
"Smirnov",
"V. A.",
""
]
] | We complete the calculation of master integrals for massless three-loop form factors by computing the previously-unknown three diagrams with nine propagators in dimensional regularisation. Each of the integrals yields a six-fold Mellin-Barnes representation which we use to compute the coefficients of the Laurent expansion in epsilon. Using Riemann zeta functions of up to weight six, we give fully analytic results for one integral; for a second, analytic results for all but the finite term; for the third, analytic results for all but the last two coefficients in the Laurent expansion. The remaining coefficients are given numerically to sufficiently high accuracy for phenomenological applications. |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.