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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
2307.13731
|
Pedro De La Torre Luque
|
Pedro De la Torre Luque, Shyam Balaji, Pierluca Carenza
|
Multimessenger search for electrophilic feebly interacting particles
from supernovae
|
17 pages, 11 figures. Accepted in PRD
|
Phys. Rev. D 109, 103028. Published 17 May 2024
|
10.1103/PhysRevD.109.103028
| null |
hep-ph astro-ph.HE astro-ph.SR
|
http://creativecommons.org/licenses/by/4.0/
|
We study MeV-scale electrophilic Feebly Interacting Particles (FIPs), that
may be abundantly produced in Supernova (SN) explosions, escape the star and
decay into electrons and positrons. This exotic injection of leptons in the
Milky Way leaves an imprint in both photon and cosmic-ray fluxes. Specifically,
positrons lose energy and annihilate almost at rest with background electrons,
producing photons with $511$ keV energy. In addition, electrons and positrons
radiate photons through bremsstrahlung emission and upscatter the low-energy
galactic photon fields via the inverse Compton process generating a broad
emission from X-ray to $\gamma$-ray energies. Finally, electrons and positrons
are directly observable in cosmic ray experiments. In order to describe the
FIP-induced lepton injection in full generality, we use a model independent
parametrization which can be applied to a host of FIPs such as axion-like
particles, dark photons and sterile neutrinos. Theoretical predictions are
compared to experimental data to robustly constrain FIP-electron interactions
with an innovative multimessenger analysis.
|
[
{
"created": "Tue, 25 Jul 2023 18:00:03 GMT",
"version": "v1"
},
{
"created": "Mon, 27 May 2024 22:30:26 GMT",
"version": "v2"
}
] |
2024-05-29
|
[
[
"Luque",
"Pedro De la Torre",
""
],
[
"Balaji",
"Shyam",
""
],
[
"Carenza",
"Pierluca",
""
]
] |
We study MeV-scale electrophilic Feebly Interacting Particles (FIPs), that may be abundantly produced in Supernova (SN) explosions, escape the star and decay into electrons and positrons. This exotic injection of leptons in the Milky Way leaves an imprint in both photon and cosmic-ray fluxes. Specifically, positrons lose energy and annihilate almost at rest with background electrons, producing photons with $511$ keV energy. In addition, electrons and positrons radiate photons through bremsstrahlung emission and upscatter the low-energy galactic photon fields via the inverse Compton process generating a broad emission from X-ray to $\gamma$-ray energies. Finally, electrons and positrons are directly observable in cosmic ray experiments. In order to describe the FIP-induced lepton injection in full generality, we use a model independent parametrization which can be applied to a host of FIPs such as axion-like particles, dark photons and sterile neutrinos. Theoretical predictions are compared to experimental data to robustly constrain FIP-electron interactions with an innovative multimessenger analysis.
|
1811.03608
|
Filippo Sala
|
Marco Cirelli, Yann Gouttenoire, Kalliopi Petraki and Filippo Sala
|
Homeopathic Dark Matter, or how diluted heavy substances produce high
energy cosmic rays
|
39 pages, 11 figures. v2: reference added, fixed technical issue
causing 2 figures not to show properly. v3: BBN constraints amended,
conclusions unchanged. Matches published version
| null |
10.1088/1475-7516/2019/02/014
| null |
hep-ph astro-ph.CO astro-ph.HE
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We point out that current and planned telescopes have the potential of
probing annihilating Dark Matter (DM) with a mass of O(100) TeV and beyond. As
a target for such searches, we propose models where DM annihilates into lighter
mediators, themselves decaying into Standard Model (SM) particles. These models
allow to reliably compute the energy spectra of the SM final states, and to
naturally evade the unitarity bound on the DM mass. Indeed, long-lived
mediators may cause an early matter-dominated phase in the evolution of the
Universe and, upon decaying, dilute the density of preexisting relics thus
allowing for very large DM masses. We compute this dilution in detail and
provide results in a ready-to-use form. Considering for concreteness a model of
dark U(1) DM, we then study both dilution and the signals at various high
energy telescopes observing gamma rays, neutrinos and charged cosmic rays. This
study enriches the physics case of these experiments, and opens a new
observational window on heavy new physics sectors.
|
[
{
"created": "Thu, 8 Nov 2018 18:49:11 GMT",
"version": "v1"
},
{
"created": "Tue, 13 Nov 2018 15:10:54 GMT",
"version": "v2"
},
{
"created": "Tue, 29 Jan 2019 17:15:12 GMT",
"version": "v3"
}
] |
2019-02-20
|
[
[
"Cirelli",
"Marco",
""
],
[
"Gouttenoire",
"Yann",
""
],
[
"Petraki",
"Kalliopi",
""
],
[
"Sala",
"Filippo",
""
]
] |
We point out that current and planned telescopes have the potential of probing annihilating Dark Matter (DM) with a mass of O(100) TeV and beyond. As a target for such searches, we propose models where DM annihilates into lighter mediators, themselves decaying into Standard Model (SM) particles. These models allow to reliably compute the energy spectra of the SM final states, and to naturally evade the unitarity bound on the DM mass. Indeed, long-lived mediators may cause an early matter-dominated phase in the evolution of the Universe and, upon decaying, dilute the density of preexisting relics thus allowing for very large DM masses. We compute this dilution in detail and provide results in a ready-to-use form. Considering for concreteness a model of dark U(1) DM, we then study both dilution and the signals at various high energy telescopes observing gamma rays, neutrinos and charged cosmic rays. This study enriches the physics case of these experiments, and opens a new observational window on heavy new physics sectors.
|
hep-ph/9908502
|
Blazenka Melic
|
Blazenka Melic
|
On the perturbative approach to the penguin-induced B -> pi phi decay
|
4 pages, no figures. Talk given at the International Europhysics
Conference on High Energy Physics -- EPS-HEP '99, Tampere, Finland, 15-21
July 1999. To appear in the Proceedings
| null | null |
IRB-TH-6/99
|
hep-ph
| null |
Using a modified perturbative approach that includes the Sudakov resummation
and transverse degrees of freedom we analyze the penguin-induced B -> pi phi
decay. The perturbative method enables us to include nonfactorizable
contributions and to control virtual momenta appearing in the process. The
calculation supports the results obtained in the standard BSW factorization
approach, illustrating the electroweak penguin dominance and the branching
ratio of order O(10^{-8}). However, the estimated prediction of 16% for CP
asymmetry is much larger than that obtained in the factorization approach.
|
[
{
"created": "Mon, 30 Aug 1999 13:38:15 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Melic",
"Blazenka",
""
]
] |
Using a modified perturbative approach that includes the Sudakov resummation and transverse degrees of freedom we analyze the penguin-induced B -> pi phi decay. The perturbative method enables us to include nonfactorizable contributions and to control virtual momenta appearing in the process. The calculation supports the results obtained in the standard BSW factorization approach, illustrating the electroweak penguin dominance and the branching ratio of order O(10^{-8}). However, the estimated prediction of 16% for CP asymmetry is much larger than that obtained in the factorization approach.
|
hep-ph/0211422
|
J. Raufeisen
|
J. Raufeisen, J.-C. Peng
|
Relating parton model and color dipole formulation of heavy quark
hadroproduction
|
16 pages, 4 figures
|
Phys.Rev.D67:054008,2003
|
10.1103/PhysRevD.67.054008
|
LA-UR-02-6304
|
hep-ph
| null |
At high center of mass energies, hadroproduction of heavy quarks can be
expressed in terms of the same color dipole cross section as low Bjorken-x deep
inelastic scattering. We show analytically that at leading order, the dipole
formulation is equivalent to the gluon-gluon fusion mechanism of the
conventional parton model. In phenomenological application, we employ a
parameterization of the dipole cross section which also includes higher order
and saturation effects, thereby going beyond the parton model. Numerical
calculations in the dipole approach agree well with experimental data on open
charm production over a wide range of energy. Dipole approach and next to
leading order parton model yield similar values for open charm production, but
for open bottom production, the dipole approach tends to predict somewhat
higher cross sections than the parton model.
|
[
{
"created": "Wed, 27 Nov 2002 01:30:19 GMT",
"version": "v1"
}
] |
2011-01-25
|
[
[
"Raufeisen",
"J.",
""
],
[
"Peng",
"J. -C.",
""
]
] |
At high center of mass energies, hadroproduction of heavy quarks can be expressed in terms of the same color dipole cross section as low Bjorken-x deep inelastic scattering. We show analytically that at leading order, the dipole formulation is equivalent to the gluon-gluon fusion mechanism of the conventional parton model. In phenomenological application, we employ a parameterization of the dipole cross section which also includes higher order and saturation effects, thereby going beyond the parton model. Numerical calculations in the dipole approach agree well with experimental data on open charm production over a wide range of energy. Dipole approach and next to leading order parton model yield similar values for open charm production, but for open bottom production, the dipole approach tends to predict somewhat higher cross sections than the parton model.
|
1508.00445
|
Norimi Yokozaki
|
Hajime Fukuda, Hitoshi Murayama, Tsutomu. T. Yanagida and Norimi
Yokozaki
|
Seminatural Gauge Mediation from Product Group Unification
|
15 pages, 4 figures, corrected typos, added references and a
discussion on the SUSY CP problem
|
Phys. Rev. D 92, 055032 (2015)
|
10.1103/PhysRevD.92.055032
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We propose a focus point gauge mediation model based on the product group
unification (PGU), which solves the doublet-triplet splitting problem of the
Higgs multiplets. In the focus point gauge mediation, the electroweak symmetry
breaking scale can be naturally explained even for multi-TeV stops. It is known
that the focus point behavior appears if a ratio of the number of SU(2) doublet
messengers to that of SU(3) triplet messengers is close to 5/2. Importantly,
this ratio (effectively) appears in our scenario based on the PGU, if the
messenger field is an adjoint representation of SU(5) gauge group. Therefore,
our focus point scenario is very predictive. It is also pointed out the
gravitino can be dark matter without spoiling the success of the thermal
leptogenesis. The absence of the SUSY CP-problem is guaranteed in the case that
the Higgs B-term vanishes at the messenger scale.
|
[
{
"created": "Mon, 3 Aug 2015 15:17:35 GMT",
"version": "v1"
},
{
"created": "Fri, 25 Sep 2015 09:41:20 GMT",
"version": "v2"
}
] |
2015-10-07
|
[
[
"Fukuda",
"Hajime",
""
],
[
"Murayama",
"Hitoshi",
""
],
[
"Yanagida",
"Tsutomu. T.",
""
],
[
"Yokozaki",
"Norimi",
""
]
] |
We propose a focus point gauge mediation model based on the product group unification (PGU), which solves the doublet-triplet splitting problem of the Higgs multiplets. In the focus point gauge mediation, the electroweak symmetry breaking scale can be naturally explained even for multi-TeV stops. It is known that the focus point behavior appears if a ratio of the number of SU(2) doublet messengers to that of SU(3) triplet messengers is close to 5/2. Importantly, this ratio (effectively) appears in our scenario based on the PGU, if the messenger field is an adjoint representation of SU(5) gauge group. Therefore, our focus point scenario is very predictive. It is also pointed out the gravitino can be dark matter without spoiling the success of the thermal leptogenesis. The absence of the SUSY CP-problem is guaranteed in the case that the Higgs B-term vanishes at the messenger scale.
|
0811.2537
|
Priyotosh Bandyopadhyay
|
Priyotosh Bandyopadhyay
|
Probing non-universal gaugino masses via Higgs boson production under
SUSY cascades at the LHC: A detailed study
|
48 pages
| null |
10.1088/1126-6708/2009/07/102
|
HRI-P-08-11-003, HRI-RECAPP-08-014
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Cascade decays of Supersymmetric (SUSY) particles are likely to be prolific
sources of Higgs bosons at the Large Hadron Collider (LHC). In this work, we
explore, with the help of detailed simulation, the role of non-universal
gaugino masses in the production of the Higgs bosons under SUSY cascades. The
analysis is carried out by choosing an appropriate set of benchmark points with
non-universal gaugino masses in the relevant SUSY parameter space and then
contrasting the resulting observations with the corresponding cases having
universal relationship among the same. It is shown that even of data at an
early phase of the LHC-run with 10 fb$^{-1}$ one would be able to see, under
favourable situations, the imprint of non-universal gaugino masses by
reconstructing various Higgs boson resonances and comparing their rates. With
increased accumulated luminosities, the indications would naturally become
distinct over a larger region of the parameter space.
|
[
{
"created": "Sat, 15 Nov 2008 22:49:32 GMT",
"version": "v1"
},
{
"created": "Fri, 24 Apr 2009 10:29:27 GMT",
"version": "v2"
}
] |
2015-05-13
|
[
[
"Bandyopadhyay",
"Priyotosh",
""
]
] |
Cascade decays of Supersymmetric (SUSY) particles are likely to be prolific sources of Higgs bosons at the Large Hadron Collider (LHC). In this work, we explore, with the help of detailed simulation, the role of non-universal gaugino masses in the production of the Higgs bosons under SUSY cascades. The analysis is carried out by choosing an appropriate set of benchmark points with non-universal gaugino masses in the relevant SUSY parameter space and then contrasting the resulting observations with the corresponding cases having universal relationship among the same. It is shown that even of data at an early phase of the LHC-run with 10 fb$^{-1}$ one would be able to see, under favourable situations, the imprint of non-universal gaugino masses by reconstructing various Higgs boson resonances and comparing their rates. With increased accumulated luminosities, the indications would naturally become distinct over a larger region of the parameter space.
|
1804.07528
|
Stefano Scopel
|
Sunghyun Kang, Stefano Scopel, Gaurav Tomar, Jong-Hyun Yoon (Sogang
U.)
|
DAMA/LIBRA-phase2 in WIMP effective models
|
17 pages, 5 figures, 1 table. One high-energy control bin added to
the fit, results of Table 1 updated accordingly, no change in the conclusions
with the exception of model c5. Some references added and more details
provided in the discussion. Updated to published version
| null |
10.1088/1475-7516/2018/07/016
| null |
hep-ph astro-ph.CO
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The DAMA/LIBRA collaboration has recently released updated results from their
search for the annual modulation signal expected from Dark Matter (DM)
scattering in their NaI detectors. We have fitted the updated DAMA result for
the modulation amplitudes in terms of a Weakly Interacting Massive Particle
(WIMP) signal, parameterizing the interaction with nuclei in terms of the most
general effective Lagrangian for a WIMP particle spin up to 1/2, systematically
assuming dominance of one of the 14 possible interaction terms, and assuming
for the WIMP velocity distribution a standard Maxwellian. We find that most of
the couplings of the non-relativistic effective Hamiltonian can provide a
better fit compared to the standard Spin Independent interaction case, and with
a reduced fine-tuning of the three parameters (WIMP mass, WIMP-nucleon
effective cross-section and ratio between the WIMP-neutron and the WIMP-proton
couplings). Moreover, effective models for which the cross section depends
explicitly on the WIMP incoming velocity can provide a better fit of the DAMA
data at large values of $m_{\chi}$ compared to the standard
velocity-independent cross-section due to a different phase of the modulation
amplitudes. All the best fit solutions are in tension with exclusion plots of
both XENON1T and PICO60.
|
[
{
"created": "Fri, 20 Apr 2018 10:07:02 GMT",
"version": "v1"
},
{
"created": "Wed, 4 Jul 2018 08:10:00 GMT",
"version": "v2"
}
] |
2018-07-10
|
[
[
"Kang",
"Sunghyun",
"",
"Sogang\n U."
],
[
"Scopel",
"Stefano",
"",
"Sogang\n U."
],
[
"Tomar",
"Gaurav",
"",
"Sogang\n U."
],
[
"Yoon",
"Jong-Hyun",
"",
"Sogang\n U."
]
] |
The DAMA/LIBRA collaboration has recently released updated results from their search for the annual modulation signal expected from Dark Matter (DM) scattering in their NaI detectors. We have fitted the updated DAMA result for the modulation amplitudes in terms of a Weakly Interacting Massive Particle (WIMP) signal, parameterizing the interaction with nuclei in terms of the most general effective Lagrangian for a WIMP particle spin up to 1/2, systematically assuming dominance of one of the 14 possible interaction terms, and assuming for the WIMP velocity distribution a standard Maxwellian. We find that most of the couplings of the non-relativistic effective Hamiltonian can provide a better fit compared to the standard Spin Independent interaction case, and with a reduced fine-tuning of the three parameters (WIMP mass, WIMP-nucleon effective cross-section and ratio between the WIMP-neutron and the WIMP-proton couplings). Moreover, effective models for which the cross section depends explicitly on the WIMP incoming velocity can provide a better fit of the DAMA data at large values of $m_{\chi}$ compared to the standard velocity-independent cross-section due to a different phase of the modulation amplitudes. All the best fit solutions are in tension with exclusion plots of both XENON1T and PICO60.
|
hep-ph/0409333
|
Jacques Soffer
|
J. Soffer
|
Nucleon spin structure and its connections to various sum rules
|
10 pages, 4 figures, Invited talk presented at GDH2004, June 2-5
2004, Old Dominion University, Virginia, USA
| null |
10.1142/9789812702111_0011
|
CPT-2004/P.051
|
hep-ph
| null |
Our knowledge on the nucleon spin structure has greatly improved over the
last twenty years or so, but still many fundamental questions remain unsolved.
I will try to review some of the puzzling aspects of the origin of the nucleon
spin. I will emphasize the connection with several sum rules and, when using
this tool, the relevance of some kinematic regions for testing them in the QCD
dynamics framework.
|
[
{
"created": "Wed, 29 Sep 2004 10:20:22 GMT",
"version": "v1"
}
] |
2017-08-23
|
[
[
"Soffer",
"J.",
""
]
] |
Our knowledge on the nucleon spin structure has greatly improved over the last twenty years or so, but still many fundamental questions remain unsolved. I will try to review some of the puzzling aspects of the origin of the nucleon spin. I will emphasize the connection with several sum rules and, when using this tool, the relevance of some kinematic regions for testing them in the QCD dynamics framework.
|
1111.6098
|
Andrew Fowlie Mr.
|
Andrew Fowlie, Artur Kalinowski, Malgorzata Kazana, Leszek Roszkowski
and Yue-Lin Sming Tsai
|
Bayesian Implications of Current LHC and XENON100 Search Limits for the
Constrained MSSM
|
Accepted by PRD. Added discussions on prior dependence and the
p-value. Main conclusions unchanged. 21 pages, 12 figures
|
Phys.Rev. D85 (2012) 075012
|
10.1103/PhysRevD.85.075012
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The CMS Collaboration has released the results of its search for
supersymmetry, by applying an alphaT method to 1.1/fb of data at 7 TeV. The
null result excludes (at 95% CL) a low-mass region of the Constrained MSSM's
parameter space that was previously favored by other experiments. Additionally,
the negative result of the XENON100 dark matter search has excluded (at 90% CL)
values of the spin-independent scattering cross sections sigma^SI_p as low as
10^-8 pb. We incorporate these improved experimental constraints into a global
Bayesian fit of the Constrained MSSM by constructing approximate likelihood
functions. In the case of the alphaT limit, we simulate detector efficiency for
the CMS alphaT 1.1/fb and validate our method against the official 95% CL
contour. We identify the 68% and 95% credible posterior regions of the CMSSM
parameters, and also find the best-fit point. We find that the credible regions
change considerably once a likelihood from alphaT is included, in particular
the narrow light Higgs resonance region becomes excluded, but the focus
point/horizontal branch region remains allowed at the 1sigma level. Adding the
limit from XENON100 has a weaker additional effect, in part due to large
uncertainties in evaluating sigma^SI_p, which we include in a conservative way,
although we find that it reduces the posterior probability of the focus point
region to the 2sigma level. The new regions of high posterior favor squarks
lighter than the gluino and all but one Higgs bosons heavy. The dark matter
neutralino mass is found in the range 250 GeV <~ m_Chi1 <~ 343 GeV (at 1sigma)
while, as the result of improved limits from the LHC, the favored range of
sigma^SI_p is pushed down to values below 10^{-9} pb. We highlight tension
between (g-2)_mu and BR(b->sg), which is exacerbated by including the alphaT
limit; each constraint favors a different region of the CMSSM's mass
parameters.
|
[
{
"created": "Fri, 25 Nov 2011 20:41:12 GMT",
"version": "v1"
},
{
"created": "Tue, 27 Mar 2012 20:35:35 GMT",
"version": "v2"
}
] |
2016-09-19
|
[
[
"Fowlie",
"Andrew",
""
],
[
"Kalinowski",
"Artur",
""
],
[
"Kazana",
"Malgorzata",
""
],
[
"Roszkowski",
"Leszek",
""
],
[
"Tsai",
"Yue-Lin Sming",
""
]
] |
The CMS Collaboration has released the results of its search for supersymmetry, by applying an alphaT method to 1.1/fb of data at 7 TeV. The null result excludes (at 95% CL) a low-mass region of the Constrained MSSM's parameter space that was previously favored by other experiments. Additionally, the negative result of the XENON100 dark matter search has excluded (at 90% CL) values of the spin-independent scattering cross sections sigma^SI_p as low as 10^-8 pb. We incorporate these improved experimental constraints into a global Bayesian fit of the Constrained MSSM by constructing approximate likelihood functions. In the case of the alphaT limit, we simulate detector efficiency for the CMS alphaT 1.1/fb and validate our method against the official 95% CL contour. We identify the 68% and 95% credible posterior regions of the CMSSM parameters, and also find the best-fit point. We find that the credible regions change considerably once a likelihood from alphaT is included, in particular the narrow light Higgs resonance region becomes excluded, but the focus point/horizontal branch region remains allowed at the 1sigma level. Adding the limit from XENON100 has a weaker additional effect, in part due to large uncertainties in evaluating sigma^SI_p, which we include in a conservative way, although we find that it reduces the posterior probability of the focus point region to the 2sigma level. The new regions of high posterior favor squarks lighter than the gluino and all but one Higgs bosons heavy. The dark matter neutralino mass is found in the range 250 GeV <~ m_Chi1 <~ 343 GeV (at 1sigma) while, as the result of improved limits from the LHC, the favored range of sigma^SI_p is pushed down to values below 10^{-9} pb. We highlight tension between (g-2)_mu and BR(b->sg), which is exacerbated by including the alphaT limit; each constraint favors a different region of the CMSSM's mass parameters.
|
hep-ph/9908238
|
Marc Sher
|
Marc Sher (William and Mary)
|
Fourth Generation b-prime decays into b + Higgs
|
Minor typos fixed, reference added, sentence changed in experimental
discussion. Conclusions unchanged
|
Phys.Rev.D61:057303,2000
|
10.1103/PhysRevD.61.057303
|
WM-99-114
|
hep-ph
| null |
If a fourth generation quark exists whose mass is below 255 GeV, then the
only two-body charged current decay, b'-->cW, is doubly-Cabibbo suppressed. For
this reason, CDF has searched for the one-loop neutral current decay b' --> bZ,
assuming that the branching ratio into bZ is 100%; an analysis giving the
bounds on m_b' for smaller branching ratios is in preparation. In this Report,
we examine the neutral current decay b' --> bH, which will occur if the Higgs
mass is less than m_b'-m_b. Four different cases are examined: the sequential
case, the non-chiral isosinglet case, the non-chiral isodoublet case, and a
two-Higgs model with flavor-changing neutral currents. In the first three of
these, the rates for b' --> bZ and b' --> bH are comparable, assuming
comparable phase space factors; in the fourth, b' --> bH is completely
dominant. Thus, we emphasize the importance of giving b' mass bounds as a
function of the branching ratio into bZ, since the assumption of a 100%
branching ratio for b' --> bZ may only be valid if the Higgs mass is near or
above the b' mass.
|
[
{
"created": "Wed, 4 Aug 1999 09:00:45 GMT",
"version": "v1"
},
{
"created": "Sun, 8 Aug 1999 08:48:45 GMT",
"version": "v2"
}
] |
2011-03-23
|
[
[
"Sher",
"Marc",
"",
"William and Mary"
]
] |
If a fourth generation quark exists whose mass is below 255 GeV, then the only two-body charged current decay, b'-->cW, is doubly-Cabibbo suppressed. For this reason, CDF has searched for the one-loop neutral current decay b' --> bZ, assuming that the branching ratio into bZ is 100%; an analysis giving the bounds on m_b' for smaller branching ratios is in preparation. In this Report, we examine the neutral current decay b' --> bH, which will occur if the Higgs mass is less than m_b'-m_b. Four different cases are examined: the sequential case, the non-chiral isosinglet case, the non-chiral isodoublet case, and a two-Higgs model with flavor-changing neutral currents. In the first three of these, the rates for b' --> bZ and b' --> bH are comparable, assuming comparable phase space factors; in the fourth, b' --> bH is completely dominant. Thus, we emphasize the importance of giving b' mass bounds as a function of the branching ratio into bZ, since the assumption of a 100% branching ratio for b' --> bZ may only be valid if the Higgs mass is near or above the b' mass.
|
2108.09644
|
Yuki Kamiya
|
Y. Kamiya, K. Sasaki, T. Fukui, T. Hyodo, K. Morita, K. Ogata, A.
Ohnishi, and T. Hatsuda
|
Femtoscopic study of coupled-channel $N\Xi$ and $\Lambda\Lambda$
interactions
|
13 pages, 10 figures
| null |
10.1103/PhysRevC.105.014915
|
YITP-21-79, RIKEN-iTHEMS-Report-21, NITEP 116
|
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The momentum correlation functions of S = -2 baryon pairs (p Xi^- and Lambda
Lambda) produced in high-energy pp and pA collisions are investigated on the
basis of the coupled-channel formalism. The strong interaction is described by
the coupled-channel HAL QCD potential obtained by the lattice QCD simulations
near physical quark masses, while the hadronic source function is taken to be a
static Gaussian form. The coupled-channel effect, the threshold difference, the
realistic strong interaction, and the Coulomb interaction are fully taken into
account for the first time in the femtoscopic analysis of baryon-baryon
correlations. The characteristic features of the experimental data for the p
Xi^- and Lambda Lambda pairs at LHC are reproduced quantitatively with a
suitable choice of non-femtoscopic parameters and the source size. The
agreement between theory and experiment indicates that the N Xi (Lambda Lambda)
interaction is moderately (weakly) attractive without having a quasi-bound
(bound) state.
|
[
{
"created": "Sun, 22 Aug 2021 05:42:09 GMT",
"version": "v1"
}
] |
2022-02-09
|
[
[
"Kamiya",
"Y.",
""
],
[
"Sasaki",
"K.",
""
],
[
"Fukui",
"T.",
""
],
[
"Hyodo",
"T.",
""
],
[
"Morita",
"K.",
""
],
[
"Ogata",
"K.",
""
],
[
"Ohnishi",
"A.",
""
],
[
"Hatsuda",
"T.",
""
]
] |
The momentum correlation functions of S = -2 baryon pairs (p Xi^- and Lambda Lambda) produced in high-energy pp and pA collisions are investigated on the basis of the coupled-channel formalism. The strong interaction is described by the coupled-channel HAL QCD potential obtained by the lattice QCD simulations near physical quark masses, while the hadronic source function is taken to be a static Gaussian form. The coupled-channel effect, the threshold difference, the realistic strong interaction, and the Coulomb interaction are fully taken into account for the first time in the femtoscopic analysis of baryon-baryon correlations. The characteristic features of the experimental data for the p Xi^- and Lambda Lambda pairs at LHC are reproduced quantitatively with a suitable choice of non-femtoscopic parameters and the source size. The agreement between theory and experiment indicates that the N Xi (Lambda Lambda) interaction is moderately (weakly) attractive without having a quasi-bound (bound) state.
|
2204.04514
|
Francesco Sannino
|
Giacomo Cacciapaglia and Francesco Sannino
|
The W boson mass weighs in on the non-standard Higgs
| null | null |
10.1016/j.physletb.2022.137232
| null |
hep-ph hep-ex hep-lat
|
http://creativecommons.org/licenses/by/4.0/
|
We consider the implications of the CDF collaboration high-precision
measurement of the W boson mass on models with a non-standard Higgs. We show
that this requires an enhancement of 3-10% in the non-standard Higgs coupling
to the gauge bosons. This is naturally accommodated in dynamical models such as
the dilaton Higgs, the Technicolor and glueball Higgs. The needed composite
scale between 2 and 3 TeV can also explain the muon g-2 anomaly, as well as
possible violations of lepton flavour universality.
|
[
{
"created": "Sat, 9 Apr 2022 17:07:30 GMT",
"version": "v1"
}
] |
2022-06-15
|
[
[
"Cacciapaglia",
"Giacomo",
""
],
[
"Sannino",
"Francesco",
""
]
] |
We consider the implications of the CDF collaboration high-precision measurement of the W boson mass on models with a non-standard Higgs. We show that this requires an enhancement of 3-10% in the non-standard Higgs coupling to the gauge bosons. This is naturally accommodated in dynamical models such as the dilaton Higgs, the Technicolor and glueball Higgs. The needed composite scale between 2 and 3 TeV can also explain the muon g-2 anomaly, as well as possible violations of lepton flavour universality.
|
1609.07647
|
Daniel Boyanovsky
|
Louis Lello, Daniel Boyanovsky, Robert D. Pisarski
|
Production of heavy sterile neutrinos from vector boson decay at
electroweak temperatures
|
published version
|
Phys. Rev. D 95, 043524 (2017)
|
10.1103/PhysRevD.95.043524
| null |
hep-ph astro-ph.CO
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In the standard model extended with a seesaw mass matrix, we study the
production of sterile neutrinos from the decay of vector bosons at $T\simeq
M_{W,Z}$. We derive a general quantum kinetic equation for the production of
sterile neutrinos and their effective mixing angles valid in a wide range of
temperature, to all orders in interactions of the standard model, and to
leading order mixing angle $\theta \ll 1$.
Production rates and effective mixing angles depend sensitively on helicity.
Positive helicity states interact more weakly with the medium and their
effective mixing angle is not modified significantly whereas the mixing angle
for negative helicity is strongly suppressed by the medium.
If $M_s \lesssim 8.35\,\mathrm{MeV}$, there are fewer states with negative
helicity produced than those with positive helicity. There is an MSW resonance
in the absence of lepton asymmetry, but is screened by the damping rate,
without production enhancement. Negative helicity states freeze-out at
$T^-_f\simeq 5\,\mathrm{GeV}$ and positive helicity states freeze-out at $T^+_f
\simeq 8\,\mathrm{GeV}$, both distributions are far from thermal. Negative
helicity states feature a broader momentum distribution than that for those
with positive helicity. Sterile neutrinos produced via vector boson decay do
not satisfy the abundance, lifetime and cosmological constraints to be the sole
dark matter component in the universe but might solve the $^{7}Li$ problem,
albeit at the very edge of the possible parameter space. A heavy sterile
neutrino with a mass of a few MeV could decay into light sterile neutrinos, of
a few keV in mass, that contribute to warm dark matter. We argue that heavy
sterile neutrinos with lifetime $\leq 1/H_0$ reach local thermodynamic
equilibrium.
|
[
{
"created": "Sat, 24 Sep 2016 17:25:33 GMT",
"version": "v1"
},
{
"created": "Wed, 5 Oct 2016 14:30:53 GMT",
"version": "v2"
},
{
"created": "Tue, 28 Feb 2017 14:37:45 GMT",
"version": "v3"
}
] |
2017-03-01
|
[
[
"Lello",
"Louis",
""
],
[
"Boyanovsky",
"Daniel",
""
],
[
"Pisarski",
"Robert D.",
""
]
] |
In the standard model extended with a seesaw mass matrix, we study the production of sterile neutrinos from the decay of vector bosons at $T\simeq M_{W,Z}$. We derive a general quantum kinetic equation for the production of sterile neutrinos and their effective mixing angles valid in a wide range of temperature, to all orders in interactions of the standard model, and to leading order mixing angle $\theta \ll 1$. Production rates and effective mixing angles depend sensitively on helicity. Positive helicity states interact more weakly with the medium and their effective mixing angle is not modified significantly whereas the mixing angle for negative helicity is strongly suppressed by the medium. If $M_s \lesssim 8.35\,\mathrm{MeV}$, there are fewer states with negative helicity produced than those with positive helicity. There is an MSW resonance in the absence of lepton asymmetry, but is screened by the damping rate, without production enhancement. Negative helicity states freeze-out at $T^-_f\simeq 5\,\mathrm{GeV}$ and positive helicity states freeze-out at $T^+_f \simeq 8\,\mathrm{GeV}$, both distributions are far from thermal. Negative helicity states feature a broader momentum distribution than that for those with positive helicity. Sterile neutrinos produced via vector boson decay do not satisfy the abundance, lifetime and cosmological constraints to be the sole dark matter component in the universe but might solve the $^{7}Li$ problem, albeit at the very edge of the possible parameter space. A heavy sterile neutrino with a mass of a few MeV could decay into light sterile neutrinos, of a few keV in mass, that contribute to warm dark matter. We argue that heavy sterile neutrinos with lifetime $\leq 1/H_0$ reach local thermodynamic equilibrium.
|
1602.06437
|
Kei Yagyu
|
Stefania De Curtis, Stefano Moretti, Kei Yagyu, Emine Yildirim
|
Perturbative Unitarity Bounds in Composite 2-Higgs Doublet Models
|
Version accepted for publication in PRD
|
Phys. Rev. D 94, 055017 (2016)
|
10.1103/PhysRevD.94.055017
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study bounds from perturbative unitarity in a Composite 2-Higgs Doublet
Model (C2HDM) based on the spontaneous breakdown of a global symmetry $SO(6)\to
SO(4)\times SO(2)$ at the compositeness scale $f$. The eight pseudo
Nambu-Goldstone Bosons (pNGBs) emerging from such a dynamics are identified as
two isospin doublet Higgs fields. We calculate the $S$-wave amplitude for all
possible 2-to-2-body elastic (pseudo)scalar boson scatterings at energy scales
$\sqrt{s}$ reachable at the Large Hadron Collider (LHC) and beyond it,
including the longitudinal components of weak gauge boson states as the
corresponding pNGB states. In our calculation, the Higgs potential is assumed
to have the same form as that in the Elementary 2-Higgs Doublet Model (E2HDM)
with a discrete $Z_2$ symmetry, which is expected to be generated at the
one-loop level via the Coleman-Weinberg (CW) mechanism. We find that the
$S$-wave amplitude matrix can be block-diagonalized with maximally $2\times 2$
submatrices in a way similar to the E2HDM case as long as we only keep the
contributions from ${\cal O }(\xi s)$ and ${\cal O }(\xi^0 s^0)$ in the
amplitudes, where $\xi=v_{\text{SM}}^2/f^2$ and $v_{\text{SM}}^{}\simeq 246$
GeV, which is an appropriate approximation for our analysis. By requiring the
C2HDM to satisfy perturbative unitarity at energies reachable by the LHC, we
derive bounds on its parameters such as $\xi$ and the masses of extra Higgs
bosons present in the scenario alongside the Standard Model (SM)-like Higgs
state discovered in 2012.
|
[
{
"created": "Sat, 20 Feb 2016 18:49:47 GMT",
"version": "v1"
},
{
"created": "Tue, 13 Sep 2016 11:51:44 GMT",
"version": "v2"
}
] |
2016-09-21
|
[
[
"De Curtis",
"Stefania",
""
],
[
"Moretti",
"Stefano",
""
],
[
"Yagyu",
"Kei",
""
],
[
"Yildirim",
"Emine",
""
]
] |
We study bounds from perturbative unitarity in a Composite 2-Higgs Doublet Model (C2HDM) based on the spontaneous breakdown of a global symmetry $SO(6)\to SO(4)\times SO(2)$ at the compositeness scale $f$. The eight pseudo Nambu-Goldstone Bosons (pNGBs) emerging from such a dynamics are identified as two isospin doublet Higgs fields. We calculate the $S$-wave amplitude for all possible 2-to-2-body elastic (pseudo)scalar boson scatterings at energy scales $\sqrt{s}$ reachable at the Large Hadron Collider (LHC) and beyond it, including the longitudinal components of weak gauge boson states as the corresponding pNGB states. In our calculation, the Higgs potential is assumed to have the same form as that in the Elementary 2-Higgs Doublet Model (E2HDM) with a discrete $Z_2$ symmetry, which is expected to be generated at the one-loop level via the Coleman-Weinberg (CW) mechanism. We find that the $S$-wave amplitude matrix can be block-diagonalized with maximally $2\times 2$ submatrices in a way similar to the E2HDM case as long as we only keep the contributions from ${\cal O }(\xi s)$ and ${\cal O }(\xi^0 s^0)$ in the amplitudes, where $\xi=v_{\text{SM}}^2/f^2$ and $v_{\text{SM}}^{}\simeq 246$ GeV, which is an appropriate approximation for our analysis. By requiring the C2HDM to satisfy perturbative unitarity at energies reachable by the LHC, we derive bounds on its parameters such as $\xi$ and the masses of extra Higgs bosons present in the scenario alongside the Standard Model (SM)-like Higgs state discovered in 2012.
|
2110.08651
|
Ahmed Rashed Dr
|
A. Hammad, Ahmed Rashed and S. Moretti
|
The Dark $Z'$ and Sterile Neutrinos Behind Current Anomalies
|
10 pages, 6 figures
|
Phys.Lett.B 827 (2022) 136945
|
10.1016/j.physletb.2022.136945
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We show how, in the $B-L$ extension of the SM (BLSM) with an Inverse Seesaw
(IS) mechanism for neutrino mass generation, a light $Z'$ state with moderate
couplings to SM objects, hence `dark' in its nature, can be associated, in
conjunction with light sterile neutrinos, to some present day data anomalies,
such as the anomalous magnetic moment of the muon as well as a possible signal
indicating the existence of sterile neutrinos in neutrino beam experiments.
|
[
{
"created": "Sat, 16 Oct 2021 20:26:02 GMT",
"version": "v1"
},
{
"created": "Mon, 7 Feb 2022 01:21:30 GMT",
"version": "v2"
}
] |
2022-02-08
|
[
[
"Hammad",
"A.",
""
],
[
"Rashed",
"Ahmed",
""
],
[
"Moretti",
"S.",
""
]
] |
We show how, in the $B-L$ extension of the SM (BLSM) with an Inverse Seesaw (IS) mechanism for neutrino mass generation, a light $Z'$ state with moderate couplings to SM objects, hence `dark' in its nature, can be associated, in conjunction with light sterile neutrinos, to some present day data anomalies, such as the anomalous magnetic moment of the muon as well as a possible signal indicating the existence of sterile neutrinos in neutrino beam experiments.
|
hep-ph/0601190
|
Mitsuo J. Hayashi
|
Mitsuo J. Hayashi, Shiro Hirai, Yusuke Okame and Tomoki Watanabe
|
Angular Power Spectrum and Dilatonic Inflation in Modular-Invariant
Supergravity
|
7 pages, 8 figures
| null | null | null |
hep-ph
| null |
The angular power spectrum is investigated in the model of supergravity,
incorporating the target-space duality and the non-perturbative gaugino
condensation in the hidden sector. The inflation and supersymmetry breaking
occur at once by the interplay between the dilaton field as inflaton and the
condensate gauge-singlet field. The model satisfies the slow-roll condition
which solves the \eta-problem. When the particle rolls down along the minimized
trajectory of the potential at a duality invariant fixed point T=1, we can
obtain the e-fold value \sim 57. And then the cosmological parameters obtained
from our model well match with the recent WMAP data combined with other
experiments. The TT and TE angular power spectra also show that our model is
compatible with the data for l > 20. However, the best fit value of \tau in our
model is smaller than that of the \Lambda CDM model. These results suggest
that, among supergravity models of inflation, the modular-invariant
supergravity seems to open a hope to construct the realistic theory of
particles and cosmology.
|
[
{
"created": "Mon, 23 Jan 2006 10:12:03 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Hayashi",
"Mitsuo J.",
""
],
[
"Hirai",
"Shiro",
""
],
[
"Okame",
"Yusuke",
""
],
[
"Watanabe",
"Tomoki",
""
]
] |
The angular power spectrum is investigated in the model of supergravity, incorporating the target-space duality and the non-perturbative gaugino condensation in the hidden sector. The inflation and supersymmetry breaking occur at once by the interplay between the dilaton field as inflaton and the condensate gauge-singlet field. The model satisfies the slow-roll condition which solves the \eta-problem. When the particle rolls down along the minimized trajectory of the potential at a duality invariant fixed point T=1, we can obtain the e-fold value \sim 57. And then the cosmological parameters obtained from our model well match with the recent WMAP data combined with other experiments. The TT and TE angular power spectra also show that our model is compatible with the data for l > 20. However, the best fit value of \tau in our model is smaller than that of the \Lambda CDM model. These results suggest that, among supergravity models of inflation, the modular-invariant supergravity seems to open a hope to construct the realistic theory of particles and cosmology.
|
1208.5481
|
Torsten Bringmann
|
Torsten Bringmann and Christoph Weniger
|
Gamma Ray Signals from Dark Matter: Concepts, Status and Prospects
|
42 pages, 6 figures, 2 tables; updated reference list and extended
discussion
|
Dark Universe 1 (2012) 194-217
|
10.1016/j.dark.2012.10.005
| null |
hep-ph astro-ph.CO astro-ph.HE
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Weakly interacting massive particles (WIMPs) remain a prime candidate for the
cosmological dark matter (DM), even in the absence of current collider signals
that would unambiguously point to new physics below the TeV scale. The
self-annihilation of these particles in astronomical targets may leave
observable imprints in cosmic rays of various kinds. In this review, we focus
on gamma rays which we argue to play a pronounced role among the various
possible messengers. We discuss the most promising spectral and spatial
signatures to look for, give an update on the current state of gamma-ray
searches for DM and an outlook concerning future prospects. We also assess in
some detail the implications of a potential signal identification for particle
DM models as well as for our understanding of structure formation. Special
emphasis is put on the possible evidence for a 130 GeV line-like signal that
was recently identified in the data of the Fermi gamma-ray space telescope.
|
[
{
"created": "Mon, 27 Aug 2012 20:00:00 GMT",
"version": "v1"
},
{
"created": "Thu, 13 Dec 2012 22:42:55 GMT",
"version": "v2"
}
] |
2012-12-17
|
[
[
"Bringmann",
"Torsten",
""
],
[
"Weniger",
"Christoph",
""
]
] |
Weakly interacting massive particles (WIMPs) remain a prime candidate for the cosmological dark matter (DM), even in the absence of current collider signals that would unambiguously point to new physics below the TeV scale. The self-annihilation of these particles in astronomical targets may leave observable imprints in cosmic rays of various kinds. In this review, we focus on gamma rays which we argue to play a pronounced role among the various possible messengers. We discuss the most promising spectral and spatial signatures to look for, give an update on the current state of gamma-ray searches for DM and an outlook concerning future prospects. We also assess in some detail the implications of a potential signal identification for particle DM models as well as for our understanding of structure formation. Special emphasis is put on the possible evidence for a 130 GeV line-like signal that was recently identified in the data of the Fermi gamma-ray space telescope.
|
hep-ph/0111081
|
Oscar Alfredo Sampayo
|
L.Tabares and O.A.Sampayo
|
$\tau$ magnetic moment in a $\gamma \gamma$ collider
|
12 pages, 8 figures, Phys.Rev.D in press
|
Phys.Rev. D65 (2002) 053012
|
10.1103/PhysRevD.65.053012
| null |
hep-ph
| null |
We analyze different observables to study the magnetic dipole moment of the
tau pairs produced by photon linear colliders. We use the circular polarized
photon beam and study distributions of polarized $\tau$ final pairs to define
sensibly asymmetries to magnetic dipole moment.
|
[
{
"created": "Wed, 7 Nov 2001 18:37:30 GMT",
"version": "v1"
}
] |
2009-11-07
|
[
[
"Tabares",
"L.",
""
],
[
"Sampayo",
"O. A.",
""
]
] |
We analyze different observables to study the magnetic dipole moment of the tau pairs produced by photon linear colliders. We use the circular polarized photon beam and study distributions of polarized $\tau$ final pairs to define sensibly asymmetries to magnetic dipole moment.
|
1410.5565
|
Luca Marzola
|
Luca Marzola
|
Strong thermal Leptogenesis: an exploded view of the low energy neutrino
parameters in the SO(10)-inspired model
|
Proceedings for the XXX-th International Workshop on High Energy
Physics "Particle and Astroparticle Physics, Gravitation and Cosmology:
Predictions, Observations and New Projects", June 23-27 2014, Protvino,
Russia
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Leptogenesis is an attractive scenario in which neutrino masses and baryon
asymmetry of the Universe are explained together under a minimal set of
assumptions.
After formulating the problem of initial conditions and introducing the
strong thermal leptogenesis conditions as solution, we show that, within the
framework provided by the \soten~model of leptogenesis, the latter lead to a
set of testable predictions on the same neutrino parameters currently under
experimental investigations.
The emerging scenario selects the normal ordering of the neutrino mass
pattern, a large value for the reactor mixing angle, $2\deg \lesssim
\theta_{13} \lesssim 20\deg$, as well as a non maximal atmospheric mixing
angle, $16\deg \lesssim \theta_{23} \lesssim 41\deg$, and favours negative
values for the Dirac phase \delta. The signature of the proposed strong thermal
\soten~solutions is in the relation obtained between the effective Majorana
mass and the lightest neutrino mass: $m_{ee} \approx 0.8 \, m_1 \approx 15 $
meV.
|
[
{
"created": "Tue, 21 Oct 2014 07:56:26 GMT",
"version": "v1"
}
] |
2014-10-22
|
[
[
"Marzola",
"Luca",
""
]
] |
Leptogenesis is an attractive scenario in which neutrino masses and baryon asymmetry of the Universe are explained together under a minimal set of assumptions. After formulating the problem of initial conditions and introducing the strong thermal leptogenesis conditions as solution, we show that, within the framework provided by the \soten~model of leptogenesis, the latter lead to a set of testable predictions on the same neutrino parameters currently under experimental investigations. The emerging scenario selects the normal ordering of the neutrino mass pattern, a large value for the reactor mixing angle, $2\deg \lesssim \theta_{13} \lesssim 20\deg$, as well as a non maximal atmospheric mixing angle, $16\deg \lesssim \theta_{23} \lesssim 41\deg$, and favours negative values for the Dirac phase \delta. The signature of the proposed strong thermal \soten~solutions is in the relation obtained between the effective Majorana mass and the lightest neutrino mass: $m_{ee} \approx 0.8 \, m_1 \approx 15 $ meV.
|
0904.1584
|
David Simmons-Duffin
|
Lisa Randall and David Simmons-Duffin
|
Quark and Lepton Flavor Physics from F-Theory
|
22 pages, 6 figures
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Recent work on local F-theory models shows the potential for new categories
of flavor models. In this paper we investigate the perturbative effective
theory interpretation of this result. We also show how to extend the model to
the neutrino sector.
|
[
{
"created": "Thu, 9 Apr 2009 19:22:19 GMT",
"version": "v1"
}
] |
2009-04-10
|
[
[
"Randall",
"Lisa",
""
],
[
"Simmons-Duffin",
"David",
""
]
] |
Recent work on local F-theory models shows the potential for new categories of flavor models. In this paper we investigate the perturbative effective theory interpretation of this result. We also show how to extend the model to the neutrino sector.
|
1602.07454
|
Tomohiro Matsuda
|
Seishi Enomoto and Tomohiro Matsuda
|
Particle production with L-R neutrino oscillation
|
6 pages, no figure, to appear in PRD
| null |
10.1103/PhysRevD.93.063504
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
When the Higgs field starts oscillation after Higgs inflation, gauge bosons
are produced non-perturbatively near the Enhanced Symmetry Point (ESP). Just
after the particle production, when the Higgs field is going away from the ESP,
these gauge bosons gain mass and decay or annihilate into Standard Model (SM)
fermions. Left-handed neutrinos can be generated in that way. If one assumes
the see-saw mechanism, the mass matrix of a pair of left and right-handed
neutrinos is non-diagonal. Although their mixing in the mass eigenstates is
negligible in the true vacuum, it could be significant near the edge of the
Higgs oscillation, where the off-diagonal component is large. Therefore, the
left-handed neutrinos generated from the gauge bosons can start neutrino
oscillation between the right-handed neutrinos. We study the particle
production when such L-R neutrino oscillation is significant. For a working
example, the non-thermal leptogenesis scenario after Higgs inflation is
examined, which cannot be realized without the L-R neutrino oscillation. The
same mechanism could be applied to other singlet particles whose abundance has
been neglected.
|
[
{
"created": "Wed, 24 Feb 2016 10:14:52 GMT",
"version": "v1"
}
] |
2016-03-23
|
[
[
"Enomoto",
"Seishi",
""
],
[
"Matsuda",
"Tomohiro",
""
]
] |
When the Higgs field starts oscillation after Higgs inflation, gauge bosons are produced non-perturbatively near the Enhanced Symmetry Point (ESP). Just after the particle production, when the Higgs field is going away from the ESP, these gauge bosons gain mass and decay or annihilate into Standard Model (SM) fermions. Left-handed neutrinos can be generated in that way. If one assumes the see-saw mechanism, the mass matrix of a pair of left and right-handed neutrinos is non-diagonal. Although their mixing in the mass eigenstates is negligible in the true vacuum, it could be significant near the edge of the Higgs oscillation, where the off-diagonal component is large. Therefore, the left-handed neutrinos generated from the gauge bosons can start neutrino oscillation between the right-handed neutrinos. We study the particle production when such L-R neutrino oscillation is significant. For a working example, the non-thermal leptogenesis scenario after Higgs inflation is examined, which cannot be realized without the L-R neutrino oscillation. The same mechanism could be applied to other singlet particles whose abundance has been neglected.
|
1811.03849
|
Ye Xing
|
Gang Li, Xiao-Feng Wang, Ye Xing
|
Weak Decays of Doubly-Heavy Tetraquarks ${b\bar c}{q\bar q}$
|
14 pages,3 figures
|
Eur. Phys. J. C (2019) 79: 210
|
10.1140/epjc/s10052-019-6729-0
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study the weak decays of exotic tetraquark states ${b\bar c}{q\bar q}$
with two heavy quarks. Under the SU(3) symmetry for light quarks, these
tetraquarks can be classified into an octet plus a singlet: $3\bigotimes\bar
3=1\bigoplus8$. We will concentrate on the octet tetraquarks with
$J^{P}=0^{+}$, and study their weak decays, both semileptonic and nonleptonic.
Hadron-level effective Hamiltonian is constructed according to the irreducible
representations of the SU(3) group. Expanding the Hamiltonian, we obtain the
decay amplitudes parameterized in terms of a few irreducible quantities. Based
on these amplitudes, relations for decay widths are derived, which can be
tested in future. We also give a list of golden channels that can be used to
look for these states at various colliders.
|
[
{
"created": "Fri, 9 Nov 2018 10:22:54 GMT",
"version": "v1"
}
] |
2019-03-12
|
[
[
"Li",
"Gang",
""
],
[
"Wang",
"Xiao-Feng",
""
],
[
"Xing",
"Ye",
""
]
] |
We study the weak decays of exotic tetraquark states ${b\bar c}{q\bar q}$ with two heavy quarks. Under the SU(3) symmetry for light quarks, these tetraquarks can be classified into an octet plus a singlet: $3\bigotimes\bar 3=1\bigoplus8$. We will concentrate on the octet tetraquarks with $J^{P}=0^{+}$, and study their weak decays, both semileptonic and nonleptonic. Hadron-level effective Hamiltonian is constructed according to the irreducible representations of the SU(3) group. Expanding the Hamiltonian, we obtain the decay amplitudes parameterized in terms of a few irreducible quantities. Based on these amplitudes, relations for decay widths are derived, which can be tested in future. We also give a list of golden channels that can be used to look for these states at various colliders.
|
2010.02763
|
Hajime Fukuda
|
Hajime Fukuda, Aneesh V. Manohar, Hitoshi Murayama, Ofri Telem
|
Axion strings are superconducting
|
40 pages, 11 figures
| null |
10.1007/JHEP06(2021)052
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We explore the cosmological consequences of the superconductivity of QCD
axion strings. Axion strings can support a sizeable chiral electric current and
charge, which alters their early universe dynamics. Shrinking axion string
loops can become effectively stable remnants called vortons, supported by the
electromagnetic force of the string current. Generically, vortons produced by
axion strings overclose the universe, unless there are efficient current
leakage processes. Furthermore, if a primordial magnetic field (PMF) exists in
the early universe, a large current is induced on axion strings, creating a
significant drag force from interactions with the surrounding plasma. As a
result, the strings are slowed down, which leads to an orders of magnitude
enhancement in the number of strings per Hubble volume. Finally, we study the
implications for the QCD axion relic abundance. The QCD axion window is shifted
by orders of magnitude in some parts of our parameter space.
|
[
{
"created": "Tue, 6 Oct 2020 14:31:40 GMT",
"version": "v1"
},
{
"created": "Sun, 11 Oct 2020 02:40:13 GMT",
"version": "v2"
},
{
"created": "Mon, 24 May 2021 06:53:19 GMT",
"version": "v3"
},
{
"created": "Tue, 29 Jun 2021 07:55:55 GMT",
"version": "v4"
}
] |
2021-06-30
|
[
[
"Fukuda",
"Hajime",
""
],
[
"Manohar",
"Aneesh V.",
""
],
[
"Murayama",
"Hitoshi",
""
],
[
"Telem",
"Ofri",
""
]
] |
We explore the cosmological consequences of the superconductivity of QCD axion strings. Axion strings can support a sizeable chiral electric current and charge, which alters their early universe dynamics. Shrinking axion string loops can become effectively stable remnants called vortons, supported by the electromagnetic force of the string current. Generically, vortons produced by axion strings overclose the universe, unless there are efficient current leakage processes. Furthermore, if a primordial magnetic field (PMF) exists in the early universe, a large current is induced on axion strings, creating a significant drag force from interactions with the surrounding plasma. As a result, the strings are slowed down, which leads to an orders of magnitude enhancement in the number of strings per Hubble volume. Finally, we study the implications for the QCD axion relic abundance. The QCD axion window is shifted by orders of magnitude in some parts of our parameter space.
|
hep-ph/0305268
|
S. Arunagiri
|
S. Arunagiri and C. Q. Geng (National Tsing Hua University, Taiwan)
|
Triple product correlations in B --> anti-Lambda p pi
|
11 pages, RevTex
| null | null | null |
hep-ph hep-ex
| null |
Triple product correlations (TPC's) involving strange quark spin are
elucidated in b --> u u(bar) s process within the standard model. They arise
when light quark masses are nonzero. As the momenta and spins of constituent
quarks are related to that of the parent hadron, the quark masses are, however
small, important and relevant in TPC studies. At this level the TPC's of
interest are of the form s_s.[p_u X p_u(bar)] and s_s.[p_s X p_u]. As an
application, we look at T-violating effects in B --> anti-Lambda p pi through
the TPC s_\Lambda.[p_\Lambda X p_p] for which triple product asymmetry is found
to be 5.7%-7.6% in the vanishing limit of the strong phase.
|
[
{
"created": "Fri, 23 May 2003 14:47:12 GMT",
"version": "v1"
},
{
"created": "Sat, 24 May 2003 18:08:56 GMT",
"version": "v2"
}
] |
2007-05-23
|
[
[
"Arunagiri",
"S.",
"",
"National Tsing Hua University, Taiwan"
],
[
"Geng",
"C. Q.",
"",
"National Tsing Hua University, Taiwan"
]
] |
Triple product correlations (TPC's) involving strange quark spin are elucidated in b --> u u(bar) s process within the standard model. They arise when light quark masses are nonzero. As the momenta and spins of constituent quarks are related to that of the parent hadron, the quark masses are, however small, important and relevant in TPC studies. At this level the TPC's of interest are of the form s_s.[p_u X p_u(bar)] and s_s.[p_s X p_u]. As an application, we look at T-violating effects in B --> anti-Lambda p pi through the TPC s_\Lambda.[p_\Lambda X p_p] for which triple product asymmetry is found to be 5.7%-7.6% in the vanishing limit of the strong phase.
|
1903.01184
|
Arlene Cristina Aguilar
|
A. C. Aguilar, M. N. Ferreira, C. T. Figueiredo, J. Papavassiliou
|
Nonperturbative Ball-Chiu construction of the three-gluon vertex
|
55 pages, 18 figures
|
Phys. Rev. D 99, 094010 (2019)
|
10.1103/PhysRevD.99.094010
| null |
hep-ph hep-lat hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We present the detailed derivation of the longitudinal part of the
three-gluon vertex from the Slavnov-Taylor identities that it satisfies, by
means of a nonperturbative implementation of the Ball-Chiu construction; the
latter, in its original form, involves the inverse gluon propagator, the ghost
dressing function, and certain form factors of the ghost-gluon kernel. The main
conceptual subtlety that renders this endeavor nontrivial is the infrared
finiteness of the gluon propagator, and the resulting need to separate the
vertex into two pieces, one that is intimately connected with the emergence of
a gluonic mass scale, and one that satisfies the original set of Slavnov-Taylor
identities, but with the inverse gluon propagator replaced by its "kinetic"
term. The longitudinal form factors obtained by this construction are presented
for arbitrary Euclidean momenta, as well as special kinematic configurations,
parametrized by a single momentum. A particularly preeminent feature of the
components comprising the tree-level vertex is their considerable suppression
for momenta below 1 GeV, and the appearance of the characteristic
"zero-crossing" in the vicinity of 100-200 MeV. Special combinations of the
form factors derived with this method are compared with the results of recent
large-volume lattice simulations as well as Schwinger-Dyson equations, and good
overall agreement is found. A variety of issues related to the distribution of
the pole terms responsible for the gluon mass generation are discussed in
detail, and their impact on the structure of the transverse parts is
elucidated. In addition, a brief account of several theoretical and
phenomenological possibilities involving these newly acquired results is
presented.
|
[
{
"created": "Mon, 4 Mar 2019 11:40:20 GMT",
"version": "v1"
}
] |
2019-05-15
|
[
[
"Aguilar",
"A. C.",
""
],
[
"Ferreira",
"M. N.",
""
],
[
"Figueiredo",
"C. T.",
""
],
[
"Papavassiliou",
"J.",
""
]
] |
We present the detailed derivation of the longitudinal part of the three-gluon vertex from the Slavnov-Taylor identities that it satisfies, by means of a nonperturbative implementation of the Ball-Chiu construction; the latter, in its original form, involves the inverse gluon propagator, the ghost dressing function, and certain form factors of the ghost-gluon kernel. The main conceptual subtlety that renders this endeavor nontrivial is the infrared finiteness of the gluon propagator, and the resulting need to separate the vertex into two pieces, one that is intimately connected with the emergence of a gluonic mass scale, and one that satisfies the original set of Slavnov-Taylor identities, but with the inverse gluon propagator replaced by its "kinetic" term. The longitudinal form factors obtained by this construction are presented for arbitrary Euclidean momenta, as well as special kinematic configurations, parametrized by a single momentum. A particularly preeminent feature of the components comprising the tree-level vertex is their considerable suppression for momenta below 1 GeV, and the appearance of the characteristic "zero-crossing" in the vicinity of 100-200 MeV. Special combinations of the form factors derived with this method are compared with the results of recent large-volume lattice simulations as well as Schwinger-Dyson equations, and good overall agreement is found. A variety of issues related to the distribution of the pole terms responsible for the gluon mass generation are discussed in detail, and their impact on the structure of the transverse parts is elucidated. In addition, a brief account of several theoretical and phenomenological possibilities involving these newly acquired results is presented.
|
hep-ph/0506030
|
Michal Praszalowicz
|
Michal Praszalowicz
|
Chiral Soliton Model Predictions for Pentaquarks
|
Presented at 40th Rencontres de Moriond on QCD and High Energy
Hadronic Interactions, La Thuile, Aosta Valley, Italy, 12-19 Mar 2005
| null | null | null |
hep-ph
| null |
We briefly describe chiral soliton model description of baryons and
predictions for exotic antidecuplet. We discuss successful phenomenology which
triggered experimental searches and problems which arise in the formal limit of
large Nc.
|
[
{
"created": "Fri, 3 Jun 2005 18:03:09 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Praszalowicz",
"Michal",
""
]
] |
We briefly describe chiral soliton model description of baryons and predictions for exotic antidecuplet. We discuss successful phenomenology which triggered experimental searches and problems which arise in the formal limit of large Nc.
|
0707.3439
|
Vincenzo Cirigliano
|
Vincenzo Cirigliano and Ignasi Rosell
|
The Standard Model prediction for R_{e/mu}^{(pi,K)}
|
4 pages, 1 figure, 2 tables
|
Phys.Rev.Lett.99:231801,2007
|
10.1103/PhysRevLett.99.231801
|
LAUR-07-3194
|
hep-ph
| null |
We study the ratios R_{e/mu}^{(P)} = Gamma(P -> e nu [gamma])/Gamma(P -> mu
nu [gamma]) (P=pi,K) in Chiral Perturbation Theory to order e^2 p^4. We
complement the two-loop effective theory results with a matching calculation of
the counterterm, finding R_{e/mu}^{(pi)} = (1.2352 \pm 0.0001)*10^(-4) and
R_{e/mu}^{(K)} = (2.477 \pm 0.001)*10^(-5).
|
[
{
"created": "Mon, 23 Jul 2007 19:43:36 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Cirigliano",
"Vincenzo",
""
],
[
"Rosell",
"Ignasi",
""
]
] |
We study the ratios R_{e/mu}^{(P)} = Gamma(P -> e nu [gamma])/Gamma(P -> mu nu [gamma]) (P=pi,K) in Chiral Perturbation Theory to order e^2 p^4. We complement the two-loop effective theory results with a matching calculation of the counterterm, finding R_{e/mu}^{(pi)} = (1.2352 \pm 0.0001)*10^(-4) and R_{e/mu}^{(K)} = (2.477 \pm 0.001)*10^(-5).
|
1812.06977
|
Yiannis Makris
|
Yang-Ting Chien, Daekyoung Kang, Kyle Lee, and Yiannis Makris
|
Subtracted Cumulants: Mitigating Large Background in Jet Substructure
| null |
Phys. Rev. D 100, 074030 (2019)
|
10.1103/PhysRevD.100.074030
|
LA-UR-18-31092, MIT-CTP 5088
|
hep-ph hep-ex
|
http://creativecommons.org/licenses/by/4.0/
|
We introduce a new approach for jet physics studies using subtracted
cumulants of jet substructure observables, which are shown to be insensitive to
contributions from soft-particle emissions uncorrelated with the hard process.
Therefore subtracted cumulants allow comparisons between theoretical
calculations and experimental measurements without the complication of large
background contaminations such as underlying and pile-up events in hadron
collisions. We test our method using subtracted jet mass cumulants by comparing
Monte Carlo simulations to analytic calculations performed using soft-collinear
effective theory. We find that, for proton-proton collisions, the method
efficiently eliminates contributions from multiparton interactions and pile-up
events. We also find within theoretical uncertainty our analytic calculations
are in good agreement with the subtracted cumulants calculated by using ATLAS
jet mass measurements.
|
[
{
"created": "Mon, 17 Dec 2018 19:00:00 GMT",
"version": "v1"
},
{
"created": "Thu, 31 Oct 2019 11:00:16 GMT",
"version": "v2"
}
] |
2019-11-06
|
[
[
"Chien",
"Yang-Ting",
""
],
[
"Kang",
"Daekyoung",
""
],
[
"Lee",
"Kyle",
""
],
[
"Makris",
"Yiannis",
""
]
] |
We introduce a new approach for jet physics studies using subtracted cumulants of jet substructure observables, which are shown to be insensitive to contributions from soft-particle emissions uncorrelated with the hard process. Therefore subtracted cumulants allow comparisons between theoretical calculations and experimental measurements without the complication of large background contaminations such as underlying and pile-up events in hadron collisions. We test our method using subtracted jet mass cumulants by comparing Monte Carlo simulations to analytic calculations performed using soft-collinear effective theory. We find that, for proton-proton collisions, the method efficiently eliminates contributions from multiparton interactions and pile-up events. We also find within theoretical uncertainty our analytic calculations are in good agreement with the subtracted cumulants calculated by using ATLAS jet mass measurements.
|
hep-ph/9812508
|
Guey-Lin Lin
|
Hsiang-nan Li(NCKU), Guey-Lin Lin(NCTU)
|
Perturbative QCD study of the B-> K^* gamma decay
|
17 pages, 4 figures; version to appear in Phys. Rev. D
|
Phys. Rev. D 60, 054001 (1999)
|
10.1103/PhysRevD.60.054001
|
NCKU-HEP-98-14, NCTU-HEP-9806
|
hep-ph
| null |
We apply the perturbative QCD factorization theorem developed recently for
nonleptonic heavy meson decays to the radiative decay $B\to K^*\gamma$. In this
formalism the evolution of the Wilson coefficients from the $W$ boson mass down
to the characteristic scale of the decay process is governed by the effective
weak Hamiltonian. The evolution from the characteristic scale to a lower
hadronic scale is formulated by the Sudakov resummation. Besides computing the
dominant contribution arising from the magnetic-penguin operator $O_7$, we also
calculate the contributions of four-quark operators. By fitting our prediction
for the branching ratio of the $B\to K^*\gamma$ decay to the CLEO data, we
determine the $B$ meson wave function, that possesses a sharp peak at a low
momentum fraction.
|
[
{
"created": "Mon, 28 Dec 1998 10:03:08 GMT",
"version": "v1"
},
{
"created": "Fri, 30 Apr 1999 04:49:45 GMT",
"version": "v2"
}
] |
2016-08-25
|
[
[
"Li",
"Hsiang-nan",
"",
"NCKU"
],
[
"Lin",
"Guey-Lin",
"",
"NCTU"
]
] |
We apply the perturbative QCD factorization theorem developed recently for nonleptonic heavy meson decays to the radiative decay $B\to K^*\gamma$. In this formalism the evolution of the Wilson coefficients from the $W$ boson mass down to the characteristic scale of the decay process is governed by the effective weak Hamiltonian. The evolution from the characteristic scale to a lower hadronic scale is formulated by the Sudakov resummation. Besides computing the dominant contribution arising from the magnetic-penguin operator $O_7$, we also calculate the contributions of four-quark operators. By fitting our prediction for the branching ratio of the $B\to K^*\gamma$ decay to the CLEO data, we determine the $B$ meson wave function, that possesses a sharp peak at a low momentum fraction.
|
1607.06727
|
Teppei Kitahara
|
Teppei Kitahara, Ulrich Nierste, Paul Tremper
|
Singularity-free Next-to-leading Order $\Delta S= 1$ Renormalization
Group Evolution and $\epsilon_{K}^{\prime}/\epsilon_{K}$ in the Standard
Model and Beyond
|
42 pages, 2 figures, 6 tables; formulae corrected, numerical results
almost unchanged, to be published in JHEP
|
JHEP 1612 (2016) 078
|
10.1007/JHEP12(2016)078
|
TTP16-029
|
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The standard analytic solution of the renormalization group (RG) evolution
for the $\Delta S = 1$ Wilson coefficients involves several singularities,
which complicate analytic solutions. In this paper we derive a singularity-free
solution of the next-to-leading order (NLO) RG equations, which greatly
facilitates the calculation of $\epsilon_K^{\prime}$, the measure of direct
$CP$ violation in $K\to \pi\pi$ decays. Using our new RG evolution and the
latest lattice results for the hadronic matrix elements, we calculate the ratio
$\epsilon_{K}^{\prime}/\epsilon_{K}$ (with $\epsilon_{K}$ quantifying indirect
$CP$ violation) in the Standard Model (SM) at NLO to
$\epsilon_{K}^{\prime}/\epsilon_{K} = (1.06 \pm 5.07) \times 10^{-4} $, which
is $2.8\,\sigma$ below the experimental value. We also present the evolution
matrix in the high-energy regime for calculations of new physics contributions
and derive easy-to-use approximate formulae. We find that the RG amplification
of new-physics contributions to Wilson coefficients of the electroweak penguin
operators is further enhanced by the NLO corrections: If the new contribution
is generated at the scale of 1-10 TeV, the RG evolution between the new-physics
scale and the electroweak scale enhances these coefficients by 50-100 %. Our
solution contains a term of order $\alpha_{EM}^2/\alpha_s^2$, which is
numerically unimportant for the SM case but should be included in studies of
high-scale new-physics.
|
[
{
"created": "Fri, 22 Jul 2016 16:29:27 GMT",
"version": "v1"
},
{
"created": "Fri, 25 Nov 2016 15:00:32 GMT",
"version": "v2"
}
] |
2016-12-21
|
[
[
"Kitahara",
"Teppei",
""
],
[
"Nierste",
"Ulrich",
""
],
[
"Tremper",
"Paul",
""
]
] |
The standard analytic solution of the renormalization group (RG) evolution for the $\Delta S = 1$ Wilson coefficients involves several singularities, which complicate analytic solutions. In this paper we derive a singularity-free solution of the next-to-leading order (NLO) RG equations, which greatly facilitates the calculation of $\epsilon_K^{\prime}$, the measure of direct $CP$ violation in $K\to \pi\pi$ decays. Using our new RG evolution and the latest lattice results for the hadronic matrix elements, we calculate the ratio $\epsilon_{K}^{\prime}/\epsilon_{K}$ (with $\epsilon_{K}$ quantifying indirect $CP$ violation) in the Standard Model (SM) at NLO to $\epsilon_{K}^{\prime}/\epsilon_{K} = (1.06 \pm 5.07) \times 10^{-4} $, which is $2.8\,\sigma$ below the experimental value. We also present the evolution matrix in the high-energy regime for calculations of new physics contributions and derive easy-to-use approximate formulae. We find that the RG amplification of new-physics contributions to Wilson coefficients of the electroweak penguin operators is further enhanced by the NLO corrections: If the new contribution is generated at the scale of 1-10 TeV, the RG evolution between the new-physics scale and the electroweak scale enhances these coefficients by 50-100 %. Our solution contains a term of order $\alpha_{EM}^2/\alpha_s^2$, which is numerically unimportant for the SM case but should be included in studies of high-scale new-physics.
|
hep-ph/0103143
|
Chi-Sing Lam
|
C.S. Lam (McGill University)
|
Implementing Unitarity in Perturbation Theory
|
to appear in Phys. Rev. D
|
Phys.Rev. D63 (2001) 097901
|
10.1103/PhysRevD.63.097901
| null |
hep-ph
| null |
Unitarity cannot be perserved order by order in ordinary perturbation theory
because the constraint $UU^\dagger=\1$ is nonlinear. However, the corresponding
constraint for $K=\ln U$, being $K=-K^\dagger$, is linear so it can be
maintained in every order in a perturbative expansion of $K$. The perturbative
expansion of $K$ may be considered as a non-abelian generalization of the
linked-cluster expansion in probability theory and in statistical mechanics,
and possesses similar advantages resulting from separating the short-range
correlations from long-range effects. This point is illustrated in two QCD
examples, in which delicate cancellations encountered in summing Feynman
diagrams of are avoided when they are calculated via the perturbative expansion
of $K$. Applications to other problems are briefly discussed.
|
[
{
"created": "Tue, 13 Mar 2001 21:06:40 GMT",
"version": "v1"
},
{
"created": "Wed, 14 Mar 2001 18:33:36 GMT",
"version": "v2"
}
] |
2009-11-07
|
[
[
"Lam",
"C. S.",
"",
"McGill University"
]
] |
Unitarity cannot be perserved order by order in ordinary perturbation theory because the constraint $UU^\dagger=\1$ is nonlinear. However, the corresponding constraint for $K=\ln U$, being $K=-K^\dagger$, is linear so it can be maintained in every order in a perturbative expansion of $K$. The perturbative expansion of $K$ may be considered as a non-abelian generalization of the linked-cluster expansion in probability theory and in statistical mechanics, and possesses similar advantages resulting from separating the short-range correlations from long-range effects. This point is illustrated in two QCD examples, in which delicate cancellations encountered in summing Feynman diagrams of are avoided when they are calculated via the perturbative expansion of $K$. Applications to other problems are briefly discussed.
|
hep-ph/0203198
|
Andreas Ringwald
|
Z. Fodor, S.D. Katz, A. Ringwald
|
Relic neutrino masses and the highest energy cosmic rays
|
19 pages, 22 figures, REVTeX 4
|
JHEP 0206 (2002) 046
|
10.1088/1126-6708/2002/06/046
|
ITP-Budapest 581, DESY 02-014
|
hep-ph astro-ph
| null |
We consider the possibility that a large fraction of the ultrahigh energy
cosmic rays are decay products of Z bosons which were produced in the
scattering of ultrahigh energy cosmic neutrinos on cosmological relic
neutrinos. We compare the observed ultrahigh energy cosmic ray spectrum with
the one predicted in the above Z-burst scenario and determine the required mass
of the heaviest relic neutrino as well as the necessary ultrahigh energy cosmic
neutrino flux via a maximum likelihood analysis. We show that the value of the
neutrino mass obtained in this way is fairly robust against variations in
presently unknown quantities, like the amount of neutrino clustering, the
universal radio background, and the extragalactic magnetic field, within their
anticipated uncertainties. Much stronger systematics arises from different
possible assumptions about the diffuse background of ordinary cosmic rays from
unresolved astrophysical sources. In the most plausible case that these
ordinary cosmic rays are protons of extragalactic origin, one is lead to a
required neutrino mass in the range 0.08 eV - 1.3 eV at the 68 % confidence
level. This range narrows down considerably if a particular universal radio
background is assumed, e.g. to 0.08 eV - 0.40 eV for a large one. The required
flux of ultrahigh energy cosmic neutrinos near the resonant energy should be
detected in the near future by AMANDA, RICE, and the Pierre Auger Observatory,
otherwise the Z-burst scenario will be ruled out.
|
[
{
"created": "Wed, 20 Mar 2002 15:47:27 GMT",
"version": "v1"
}
] |
2009-11-07
|
[
[
"Fodor",
"Z.",
""
],
[
"Katz",
"S. D.",
""
],
[
"Ringwald",
"A.",
""
]
] |
We consider the possibility that a large fraction of the ultrahigh energy cosmic rays are decay products of Z bosons which were produced in the scattering of ultrahigh energy cosmic neutrinos on cosmological relic neutrinos. We compare the observed ultrahigh energy cosmic ray spectrum with the one predicted in the above Z-burst scenario and determine the required mass of the heaviest relic neutrino as well as the necessary ultrahigh energy cosmic neutrino flux via a maximum likelihood analysis. We show that the value of the neutrino mass obtained in this way is fairly robust against variations in presently unknown quantities, like the amount of neutrino clustering, the universal radio background, and the extragalactic magnetic field, within their anticipated uncertainties. Much stronger systematics arises from different possible assumptions about the diffuse background of ordinary cosmic rays from unresolved astrophysical sources. In the most plausible case that these ordinary cosmic rays are protons of extragalactic origin, one is lead to a required neutrino mass in the range 0.08 eV - 1.3 eV at the 68 % confidence level. This range narrows down considerably if a particular universal radio background is assumed, e.g. to 0.08 eV - 0.40 eV for a large one. The required flux of ultrahigh energy cosmic neutrinos near the resonant energy should be detected in the near future by AMANDA, RICE, and the Pierre Auger Observatory, otherwise the Z-burst scenario will be ruled out.
|
hep-ph/9710557
|
Jos\i Antonio Oller
|
J.A.Oller, E.Oset
|
Theoretical Study of the \gamma\gamma-->meson-meson Reaction (HADRON'97)
|
4 pages, LaTeX, macros aipproc.cls, aipproc.sty
|
AIP Conf.Proc.432:413-416,1998
|
10.1063/1.56064
| null |
hep-ph
| null |
We present a unified picture which studies simultaneously the gamma gamma-->
pi^+ pi^-, pi^0 pi^0,K^+ K^-, K^0 bar{K}^0, pi^0 eta reactions up to about
sqrt(s)=1.4 GeV reproducing the experimental cross sections. The present work
implements in an accurate way the final state interactions of the meson-meson
system, which is shown to be essential in order to reproduce the data,
particularly the L=0 channel. This latter channel is treated here following a
recent theoretical work in which the meson-meson amplitudes are well reproduced
and the f_0, a_0, sigma resonances show up clearly as poles of the t matrix.
The present work, as done in earlier ones, also incorporates elements of chiral
symmetry and exchange of vector and axial resonances in the crossed channels,
as well as a direct coupling to the f_2(1270) and a_2(1320) resonances. We also
evaluate the decay width of the f_0(980) and a_0(980) resonances into the
gamma-gamma channel.
|
[
{
"created": "Fri, 31 Oct 1997 09:34:15 GMT",
"version": "v1"
}
] |
2010-11-15
|
[
[
"Oller",
"J. A.",
""
],
[
"Oset",
"E.",
""
]
] |
We present a unified picture which studies simultaneously the gamma gamma--> pi^+ pi^-, pi^0 pi^0,K^+ K^-, K^0 bar{K}^0, pi^0 eta reactions up to about sqrt(s)=1.4 GeV reproducing the experimental cross sections. The present work implements in an accurate way the final state interactions of the meson-meson system, which is shown to be essential in order to reproduce the data, particularly the L=0 channel. This latter channel is treated here following a recent theoretical work in which the meson-meson amplitudes are well reproduced and the f_0, a_0, sigma resonances show up clearly as poles of the t matrix. The present work, as done in earlier ones, also incorporates elements of chiral symmetry and exchange of vector and axial resonances in the crossed channels, as well as a direct coupling to the f_2(1270) and a_2(1320) resonances. We also evaluate the decay width of the f_0(980) and a_0(980) resonances into the gamma-gamma channel.
|
hep-ph/0101161
|
Grzegorz Wilk
|
O.V.Utyuzh, G.Wilk and Z.Wlodarczyk
|
Bose-Einstein correlations in cascade processes and non-extensive
statistics
|
containing LaTeX file and 2 eps files with figures, 6 pages
altogether. Presented at XXX-th ISMD, Tihany, October 9-15, 2000, Hungary, To
be published by World Scientific (2001) (style file ws-p8-50x6-00.cls
attached). Fig. 1 corrected (panels interchanged) and Table corrected
accordingly in part corresponding to Fig. 1
| null | null | null |
hep-ph nucl-th
| null |
We discuss the effect of nonextensivity of the emitting source on the
Bose-Einstein correlations (BEC). This is done numerically by comparing cascade
hadronization model (CAS), which is known to exhibit fractal structure in both
space-time and phase-space, with its equivalent obtained from the information
theory approach (MaxEnt), in which hadronization proceeds uniformly in the
phase-space. To this end we have developed a new method of accounting for BEC
in Monte Carlo event generators, which preserves all kinematics of the
hadronization process.
|
[
{
"created": "Mon, 15 Jan 2001 17:26:08 GMT",
"version": "v1"
},
{
"created": "Thu, 25 Jan 2001 15:43:36 GMT",
"version": "v2"
},
{
"created": "Mon, 12 Feb 2001 17:06:03 GMT",
"version": "v3"
}
] |
2007-05-23
|
[
[
"Utyuzh",
"O. V.",
""
],
[
"Wilk",
"G.",
""
],
[
"Wlodarczyk",
"Z.",
""
]
] |
We discuss the effect of nonextensivity of the emitting source on the Bose-Einstein correlations (BEC). This is done numerically by comparing cascade hadronization model (CAS), which is known to exhibit fractal structure in both space-time and phase-space, with its equivalent obtained from the information theory approach (MaxEnt), in which hadronization proceeds uniformly in the phase-space. To this end we have developed a new method of accounting for BEC in Monte Carlo event generators, which preserves all kinematics of the hadronization process.
|
1305.2819
|
Abhijit Samanta
|
Abhijit Samanta
|
Comments on the reach of INO experiment: JHEP 1304, 009 (2013) and
arXiv:1303.2534 [hep-ph]
|
5 pages, 1 figure, discussions on resolutions for fully contained and
partially contained events added
| null | null | null |
hep-ph
|
http://creativecommons.org/licenses/by-nc-sa/3.0/
|
In JHEP {\bf 1304}, 009 (2013) and arXiv:1303.2534 [hep-ph] the {\it reach of
INO experiment} for determination of neutrino mass hierarchy and the
sensitivity to both $\Delta m_{32}^2$ and $\theta_{23}$ have been reported,
which are significantly underestimated and drastically different from earlier
studies JHEP {\bf 1107}, 048 (2011), Phys. Rev. D {\bf 81}, 037302 (2010) and
strongly dependent on the flux uncertainties. Here, we clarified that the
effect on oscillation probability due to change of oscillation parameters are
not considered appropriately due to improper binning of data, improper
incorporation of resolutions, and rejection of high energy events $E\gapp $ 10
GeV.
|
[
{
"created": "Mon, 13 May 2013 15:59:06 GMT",
"version": "v1"
},
{
"created": "Thu, 16 May 2013 10:49:28 GMT",
"version": "v2"
}
] |
2013-05-17
|
[
[
"Samanta",
"Abhijit",
""
]
] |
In JHEP {\bf 1304}, 009 (2013) and arXiv:1303.2534 [hep-ph] the {\it reach of INO experiment} for determination of neutrino mass hierarchy and the sensitivity to both $\Delta m_{32}^2$ and $\theta_{23}$ have been reported, which are significantly underestimated and drastically different from earlier studies JHEP {\bf 1107}, 048 (2011), Phys. Rev. D {\bf 81}, 037302 (2010) and strongly dependent on the flux uncertainties. Here, we clarified that the effect on oscillation probability due to change of oscillation parameters are not considered appropriately due to improper binning of data, improper incorporation of resolutions, and rejection of high energy events $E\gapp $ 10 GeV.
|
1304.7004
|
Gordan Krnjaic
|
Gordan Krnjaic, Yuhsin Tsai
|
Soft RPV Through the Baryon Portal
|
20 pages, 12 figures, references added, minor typos corrected
| null |
10.1007/JHEP03(2014)104
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Supersymmetric (SUSY) models with R-parity generically predict sparticle
decays with invisible neutralinos, which yield distinctive missing energy
events at colliders. Since most LHC searches are designed with this
expectation, the putative bounds on sparticle masses become considerably weaker
if R-parity is violated so that squarks and gluinos decay to jets with large
QCD backgrounds. Here we introduce a scenario in which baryonic R-parity
violation (RPV) arises effectively from soft SUSY-breaking interactions, but
leptonic RPV remains accidentally forbidden to evade constraints from proton
decay and FCNCs. The model features a global R-symmetry that initially forbids
RPV interactions, a hidden R-breaking sector, and a heavy mediator that
communicates this breaking to the visible sector. After R-symmetry breaking,
the mediator is integrated out and an effective RPV A-term arises at tree
level; RPV couplings between quarks and squarks arise only at loop level and
receive additional suppression. Although this mediator must be heavy compared
to soft masses, the model introduces no new hierarchy since viable RPV can
arise when the mediator mass is near the SUSY breaking scale. In generic
regions of parameter space, a light thermally-produced gravitino is stable and
can be a viable dark matter candidate.
|
[
{
"created": "Thu, 25 Apr 2013 20:00:02 GMT",
"version": "v1"
},
{
"created": "Wed, 15 May 2013 05:11:38 GMT",
"version": "v2"
}
] |
2014-04-01
|
[
[
"Krnjaic",
"Gordan",
""
],
[
"Tsai",
"Yuhsin",
""
]
] |
Supersymmetric (SUSY) models with R-parity generically predict sparticle decays with invisible neutralinos, which yield distinctive missing energy events at colliders. Since most LHC searches are designed with this expectation, the putative bounds on sparticle masses become considerably weaker if R-parity is violated so that squarks and gluinos decay to jets with large QCD backgrounds. Here we introduce a scenario in which baryonic R-parity violation (RPV) arises effectively from soft SUSY-breaking interactions, but leptonic RPV remains accidentally forbidden to evade constraints from proton decay and FCNCs. The model features a global R-symmetry that initially forbids RPV interactions, a hidden R-breaking sector, and a heavy mediator that communicates this breaking to the visible sector. After R-symmetry breaking, the mediator is integrated out and an effective RPV A-term arises at tree level; RPV couplings between quarks and squarks arise only at loop level and receive additional suppression. Although this mediator must be heavy compared to soft masses, the model introduces no new hierarchy since viable RPV can arise when the mediator mass is near the SUSY breaking scale. In generic regions of parameter space, a light thermally-produced gravitino is stable and can be a viable dark matter candidate.
|
hep-ph/0404286
|
Athanasios Lahanas
|
M. Argyrou, A. B. Lahanas, D. V. Nanopoulos and V. C. Spanos
|
Partial wave treatment of Supersymmetric Dark Matter in the presence of
CP - violation
|
23 pages LaTeX, 10 eps figures, version to appear in PRD
|
Phys.Rev.D70:095008,2004; Erratum-ibid.D70:119902,2004
|
10.1103/PhysRevD.70.095008 10.1103/PhysRevD.70.119902
|
MIFP-04-08, ACT-03-04, UA-NPPS/BSM-04/02, UMN-TH-2305/04,
FTPI-MINN-04/16
|
hep-ph
| null |
We present an improved partial wave analysis of the dominant LSP annihilation
channel to a fermion-antifermion pair which avoids the non-relativistic
expansion being therefore applicable near thresholds and poles. The method we
develop allows of contributions of any partial wave in the total angular
momentum J in contrast to partial wave analyses in terms of the orbital angular
momentum L of the initial state, which is usually truncated to p-waves, and
yields very accurate results. The method is formulated in such a way as to
allow easy handling of CP-violating phases residing in supersymmetric
parameters. We apply this refined partial wave technique in order to calculate
the neutralino relic density in the constrained MSSM (CMSSM) in the presence of
CP-violating terms occurring in the Higgs - mixing parameter \mu and trilinear
A coupling for large tanb. The inclusion of CP-violating phases in mu and A
does not upset significantly the picture and the annihilation of the LSP's to a
b b_bar, through Higgs exchange, is still the dominant mechanism in obtaining
cosmologically acceptable neutralino relic densities in regions far from the
stau-coannihilation and the `focus point'. Significant changes can occur if we
allow for phases in the gaugino masses and in particular the gluino mass.
|
[
{
"created": "Fri, 30 Apr 2004 12:46:00 GMT",
"version": "v1"
},
{
"created": "Sat, 19 Jun 2004 19:47:01 GMT",
"version": "v2"
},
{
"created": "Wed, 13 Oct 2004 17:16:05 GMT",
"version": "v3"
}
] |
2014-11-17
|
[
[
"Argyrou",
"M.",
""
],
[
"Lahanas",
"A. B.",
""
],
[
"Nanopoulos",
"D. V.",
""
],
[
"Spanos",
"V. C.",
""
]
] |
We present an improved partial wave analysis of the dominant LSP annihilation channel to a fermion-antifermion pair which avoids the non-relativistic expansion being therefore applicable near thresholds and poles. The method we develop allows of contributions of any partial wave in the total angular momentum J in contrast to partial wave analyses in terms of the orbital angular momentum L of the initial state, which is usually truncated to p-waves, and yields very accurate results. The method is formulated in such a way as to allow easy handling of CP-violating phases residing in supersymmetric parameters. We apply this refined partial wave technique in order to calculate the neutralino relic density in the constrained MSSM (CMSSM) in the presence of CP-violating terms occurring in the Higgs - mixing parameter \mu and trilinear A coupling for large tanb. The inclusion of CP-violating phases in mu and A does not upset significantly the picture and the annihilation of the LSP's to a b b_bar, through Higgs exchange, is still the dominant mechanism in obtaining cosmologically acceptable neutralino relic densities in regions far from the stau-coannihilation and the `focus point'. Significant changes can occur if we allow for phases in the gaugino masses and in particular the gluino mass.
|
2203.13881
|
Dhevan Gangadharan Dr.
|
Dhevan Gangadharan
|
Numerical calculation of 3-pion Coulomb scattering using scalar QED
|
6 pages, 7 figures
| null |
10.1016/j.physletb.2022.137280
| null |
hep-ph nucl-ex nucl-th
|
http://creativecommons.org/licenses/by/4.0/
|
The Coulomb scattering between three charged pions is shown to be
perturbatively calculable using scalar QED for the relative momenta accessible
to high-energy experiments of particle collisions. For the triplet relative
momenta, $Q_3 \gtrsim 50$ MeV/$c$, the calculated three-pion correlation
function at $O(\alpha^2)$ is very similar to the commonly-used triple-product
of pair factors -- Riverside approximation. At lower $Q_3$, but above the
lowest existing experimental measurement of $\sim15$ MeV/$c$, terms of
$O(\alpha^3)$ or higher are needed to obtain a convincing description of
three-pion Coulomb interactions. This is in contrast to two-pion correlations,
for which the known exact solution is shown to be saturated by the lower orders
at comparable pair relative momenta.
|
[
{
"created": "Fri, 25 Mar 2022 19:44:43 GMT",
"version": "v1"
}
] |
2022-07-06
|
[
[
"Gangadharan",
"Dhevan",
""
]
] |
The Coulomb scattering between three charged pions is shown to be perturbatively calculable using scalar QED for the relative momenta accessible to high-energy experiments of particle collisions. For the triplet relative momenta, $Q_3 \gtrsim 50$ MeV/$c$, the calculated three-pion correlation function at $O(\alpha^2)$ is very similar to the commonly-used triple-product of pair factors -- Riverside approximation. At lower $Q_3$, but above the lowest existing experimental measurement of $\sim15$ MeV/$c$, terms of $O(\alpha^3)$ or higher are needed to obtain a convincing description of three-pion Coulomb interactions. This is in contrast to two-pion correlations, for which the known exact solution is shown to be saturated by the lower orders at comparable pair relative momenta.
|
hep-ph/0210010
|
Lokhtin
|
I.P.Lokhtin
|
Jet quenching in heavy ion collisions at LHC
|
Talk given at XXXII International Symposium on Multiparticle
Dynamics, Alushta, Crimea, September 7-13, 2002; 4 pages including 3
eps-figures
| null |
10.1142/9789812704962_0033
| null |
hep-ph
| null |
We discuss the potential information about highly excited QCD-matter provided
by medium-induced partonic energy loss, known as ``jet quenching''. In
particular, with its large acceptance hadronic and electromagnetic calorimetry,
the Compact Muon Solenoid detector at LHC collider is a promising device to
study these effects. We present physics simulations of observables such as the
jet distribution with impact parameter, the azimuthal anisotropy of jet
quenching, and the effects of b-quark energy loss on the high-mass dimuon
continuum and secondary charmonium production.
|
[
{
"created": "Tue, 1 Oct 2002 09:34:50 GMT",
"version": "v1"
}
] |
2017-08-23
|
[
[
"Lokhtin",
"I. P.",
""
]
] |
We discuss the potential information about highly excited QCD-matter provided by medium-induced partonic energy loss, known as ``jet quenching''. In particular, with its large acceptance hadronic and electromagnetic calorimetry, the Compact Muon Solenoid detector at LHC collider is a promising device to study these effects. We present physics simulations of observables such as the jet distribution with impact parameter, the azimuthal anisotropy of jet quenching, and the effects of b-quark energy loss on the high-mass dimuon continuum and secondary charmonium production.
|
hep-ph/0509009
|
Sung La
|
Sung La
|
Precision Empirical Mass Formulae for Baryon Octet and Decuplet
|
11 pages, 1 figure
| null | null | null |
hep-ph
| null |
Empirical mass formulae for the baryon octet and decuplet are presented.
These formulae are functions of one integer variable and charge state of the
baryons. With an exception of Lambda(1116), the formulae generate masses within
0.1% of the observed masses. The formulae also generate the same
electromagnetic mass splittings predicted by SU(6)model. Spin 1/2 octet
resonances and its relation to the octet mass formula is described.
|
[
{
"created": "Thu, 1 Sep 2005 16:12:12 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"La",
"Sung",
""
]
] |
Empirical mass formulae for the baryon octet and decuplet are presented. These formulae are functions of one integer variable and charge state of the baryons. With an exception of Lambda(1116), the formulae generate masses within 0.1% of the observed masses. The formulae also generate the same electromagnetic mass splittings predicted by SU(6)model. Spin 1/2 octet resonances and its relation to the octet mass formula is described.
|
1209.4564
|
Fabian Bach
|
Fabian Bach, Thorsten Ohl (W\"urzburg University)
|
Anomalous Top Couplings at Hadron Colliders Revisited
|
35 pages, 11 figures. Published version
|
Phys. Rev. D 86, 114026 (2012)
|
10.1103/PhysRevD.86.114026
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In an effective operator approach, the full set of leading contributions to
anomalous top couplings comprises various new trilinear as well as higher
interaction vertices, some of which are related to one another by gauge
symmetry or equations of motion. In order to study trilinear top couplings to
SM gauge bosons such as ttA, ttZ, tbW and ttg, the operator set can be
restricted accordingly. However, the complete basis cannot be mapped onto an
on-shell parametrisation of the trilinear vertices alone. Four-fermion contact
terms qqtt and udtb must be included if the relation to the operator basis is
to be retained. In this paper, we point out how these interactions contribute
to the single top search channels for anomalous trilinear tbW couplings at the
LHC and Tevatron, thus affecting the corresponding bounds. All results are
based on full leading-order partonic matrix elements, thus automatically
accounting for off-shell and interference effects as well as irreducible
backgrounds. A discussion of the quantitative effects of going from on-shell
tops to full matrix elements including acceptance cuts is also provided.
|
[
{
"created": "Thu, 20 Sep 2012 15:23:59 GMT",
"version": "v1"
},
{
"created": "Mon, 24 Sep 2012 14:08:19 GMT",
"version": "v2"
},
{
"created": "Mon, 28 Jan 2013 13:53:08 GMT",
"version": "v3"
}
] |
2013-01-29
|
[
[
"Bach",
"Fabian",
"",
"Würzburg University"
],
[
"Ohl",
"Thorsten",
"",
"Würzburg University"
]
] |
In an effective operator approach, the full set of leading contributions to anomalous top couplings comprises various new trilinear as well as higher interaction vertices, some of which are related to one another by gauge symmetry or equations of motion. In order to study trilinear top couplings to SM gauge bosons such as ttA, ttZ, tbW and ttg, the operator set can be restricted accordingly. However, the complete basis cannot be mapped onto an on-shell parametrisation of the trilinear vertices alone. Four-fermion contact terms qqtt and udtb must be included if the relation to the operator basis is to be retained. In this paper, we point out how these interactions contribute to the single top search channels for anomalous trilinear tbW couplings at the LHC and Tevatron, thus affecting the corresponding bounds. All results are based on full leading-order partonic matrix elements, thus automatically accounting for off-shell and interference effects as well as irreducible backgrounds. A discussion of the quantitative effects of going from on-shell tops to full matrix elements including acceptance cuts is also provided.
|
hep-ph/9704249
|
Pietro Colangelo
|
P. Colangelo, F. De Fazio, G. Nardulli, N. Paver
|
On the QCD Sum Rule Determination of the Strange Quark Mass
|
Latex, 13 pages, 3 figures
|
Phys.Lett.B408:340-346,1997
|
10.1016/S0370-2693(97)00751-X
|
BARI-TH/97-262
|
hep-ph
| null |
In the QCD Sum Rule determination of $m_s$ using the two-point correlator of
divergences of $\Delta S=1$ vector currents, the final uncertainty on $m_s$ is
mainly due to the hadronic spectral function. Using a specific parameterization
which fully takes into account the available experimental data on the $K \pi$
($I=1/2, J^P=0^+)$ system, characterized by the presence of a relevant
nonresonant component in addition to the resonant one, we find ${\bar m_s}(1
GeV)\ge 120 MeV$. In particular, varying only the parameters describing the
nonresonant $K \pi$ component and $\Lambda_{\bar {MS}}^{n_f=3}$ we obtain
${\bar m_s}(1 GeV)=125 - 160 MeV$. This result is smaller than analogous ones
obtained by using a parameterization in terms of only resonant states. We
discuss how to systematically improve the determination of $m_s$ by this
method.
|
[
{
"created": "Mon, 7 Apr 1997 10:02:45 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Colangelo",
"P.",
""
],
[
"De Fazio",
"F.",
""
],
[
"Nardulli",
"G.",
""
],
[
"Paver",
"N.",
""
]
] |
In the QCD Sum Rule determination of $m_s$ using the two-point correlator of divergences of $\Delta S=1$ vector currents, the final uncertainty on $m_s$ is mainly due to the hadronic spectral function. Using a specific parameterization which fully takes into account the available experimental data on the $K \pi$ ($I=1/2, J^P=0^+)$ system, characterized by the presence of a relevant nonresonant component in addition to the resonant one, we find ${\bar m_s}(1 GeV)\ge 120 MeV$. In particular, varying only the parameters describing the nonresonant $K \pi$ component and $\Lambda_{\bar {MS}}^{n_f=3}$ we obtain ${\bar m_s}(1 GeV)=125 - 160 MeV$. This result is smaller than analogous ones obtained by using a parameterization in terms of only resonant states. We discuss how to systematically improve the determination of $m_s$ by this method.
|
1404.5955
|
Julian Heeck
|
James Barry, Julian Heeck, Werner Rodejohann
|
Sterile neutrinos and right-handed currents in KATRIN
|
21 pages, 10 figures; minor changes, added references. Matches
published version
|
JHEP 1407, 081 (2014)
|
10.1007/JHEP07(2014)081
| null |
hep-ph hep-ex nucl-ex nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Kurie-plot experiments allow for neutrino-mass measurements based on
kinematics in an almost model-independent manner. A future tritium-based
KATRIN-like experiment can be sensitive to light sterile neutrinos with masses
below 18 keV, which are among the prime candidates for warm dark matter. Here
we consider such keV neutrinos in left--right symmetric extensions, i.e.
coupled to right-handed currents, which allow for an enhanced contribution to
beta decay even for small active--sterile mixing, without violating
astrophysical X-ray constraints. The modified spectral shape is in principle
distinguishable from the standard contribution---especially for sterile
neutrino masses below 9 keV, which can lead to a distinct peak. We compare the
sensitivity to constraints from the LHC and neutrinoless double beta decay.
|
[
{
"created": "Wed, 23 Apr 2014 20:00:07 GMT",
"version": "v1"
},
{
"created": "Thu, 17 Jul 2014 15:20:33 GMT",
"version": "v2"
}
] |
2014-07-18
|
[
[
"Barry",
"James",
""
],
[
"Heeck",
"Julian",
""
],
[
"Rodejohann",
"Werner",
""
]
] |
Kurie-plot experiments allow for neutrino-mass measurements based on kinematics in an almost model-independent manner. A future tritium-based KATRIN-like experiment can be sensitive to light sterile neutrinos with masses below 18 keV, which are among the prime candidates for warm dark matter. Here we consider such keV neutrinos in left--right symmetric extensions, i.e. coupled to right-handed currents, which allow for an enhanced contribution to beta decay even for small active--sterile mixing, without violating astrophysical X-ray constraints. The modified spectral shape is in principle distinguishable from the standard contribution---especially for sterile neutrino masses below 9 keV, which can lead to a distinct peak. We compare the sensitivity to constraints from the LHC and neutrinoless double beta decay.
|
1605.03862
|
Heikki M\"antysaari
|
T. Lappi and H. M\"antysaari
|
Balitsky-Kovchegov equation at next-to-leading order accuracy with a
resummation of large logarithms
|
6 pages, 4 figures. Talk given by H.M. at 24th International Workshop
on Deep-Inelastic Scattering and Related Subjects
| null | null | null |
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We include resummation of large transverse logarithms into the
next-to-leading order Balitsky-Kovchegov equation. The resummed NLO evolution
equation is shown to be stable, the evolution speed being significantly reduced
by higher order corrections. The contributions from $\alpha_s^2$ terms that are
not enhanced by large logarithms are found to be numerically important close to
phenomenologically relevant initial conditions.
|
[
{
"created": "Thu, 12 May 2016 15:47:33 GMT",
"version": "v1"
}
] |
2016-05-13
|
[
[
"Lappi",
"T.",
""
],
[
"Mäntysaari",
"H.",
""
]
] |
We include resummation of large transverse logarithms into the next-to-leading order Balitsky-Kovchegov equation. The resummed NLO evolution equation is shown to be stable, the evolution speed being significantly reduced by higher order corrections. The contributions from $\alpha_s^2$ terms that are not enhanced by large logarithms are found to be numerically important close to phenomenologically relevant initial conditions.
|
2208.13903
|
Craig Roberts
|
Zhen-Ni Xu, Zhao-Qian Yao, Si-Xue Qin, Zhu-Fang Cui and Craig D.
Roberts
|
Bethe-Salpeter kernel and properties of strange-quark mesons
|
10 pages, 2 figures, 3 tables. Eur. Phys. J. (Lett) in press
| null |
10.1140/epja/s10050-023-00951-7
|
NJU-INP 065/22
|
hep-ph hep-ex hep-lat nucl-ex nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Focusing on the continuum meson bound-state problem, a novel method is used
to calculate closed-form Bethe-Salpeter kernels that are symmetry consistent
with any reasonable gluon-quark vertex, $\Gamma_\nu$, and therewith deliver a
Poincar\'e-invariant treatment of the spectrum and decay constants of the
ground- and first-excited states of $u$, $d$, $s$ mesons. The predictions
include masses of as-yet unseen states and many unmeasured decay constants. The
analysis reveals that a realistic, unified description of meson properties
(including level orderings and mass splittings) requires a sound expression of
emergent hadron mass in bound-state kernels; alternatively, that such
properties may reveal much about the emergence of mass in the standard model.
|
[
{
"created": "Mon, 29 Aug 2022 21:52:17 GMT",
"version": "v1"
},
{
"created": "Thu, 1 Sep 2022 02:33:12 GMT",
"version": "v2"
},
{
"created": "Sat, 25 Feb 2023 01:18:51 GMT",
"version": "v3"
}
] |
2023-03-22
|
[
[
"Xu",
"Zhen-Ni",
""
],
[
"Yao",
"Zhao-Qian",
""
],
[
"Qin",
"Si-Xue",
""
],
[
"Cui",
"Zhu-Fang",
""
],
[
"Roberts",
"Craig D.",
""
]
] |
Focusing on the continuum meson bound-state problem, a novel method is used to calculate closed-form Bethe-Salpeter kernels that are symmetry consistent with any reasonable gluon-quark vertex, $\Gamma_\nu$, and therewith deliver a Poincar\'e-invariant treatment of the spectrum and decay constants of the ground- and first-excited states of $u$, $d$, $s$ mesons. The predictions include masses of as-yet unseen states and many unmeasured decay constants. The analysis reveals that a realistic, unified description of meson properties (including level orderings and mass splittings) requires a sound expression of emergent hadron mass in bound-state kernels; alternatively, that such properties may reveal much about the emergence of mass in the standard model.
|
hep-ph/0609152
|
Roni Harnik
|
Gustavo Burdman, Z. Chacko, Hock-Seng Goh and Roni Harnik
|
Folded Supersymmetry and the LEP Paradox
|
18 pages, 5 figures, references corrected
|
JHEP 0702:009,2007
|
10.1088/1126-6708/2007/02/009
|
SLAC-PUB-12115
|
hep-ph
| null |
We present a new class of models that stabilize the weak scale against
radiative corrections up to scales of order 5 TeV without large corrections to
precision electroweak observables. In these `folded supersymmetric' theories
the one loop quadratic divergences of the Standard Model Higgs field are
cancelled by opposite spin partners, but the gauge quantum numbers of these new
particles are in general different from those of the conventional
superpartners. This class of models is built around the correspondence that
exists in the large N limit between the correlation functions of supersymmetric
theories and those of their non-supersymmetric orbifold daughters. By
identifying the mechanism which underlies the cancellation of one loop
quadratic divergences in these theories, we are able to construct simple
extensions of the Standard Model which are radiatively stable at one loop.
Ultraviolet completions of these theories can be obtained by imposing suitable
boundary conditions on an appropriate supersymmetric higher dimensional theory
compactified down to four dimensions. We construct a specific model based on
these ideas which stabilizes the weak scale up to about 20 TeV and where the
states which cancel the top loop are scalars not charged under Standard Model
color. Its collider signatures are distinct from conventional supersymmetric
theories and include characteristic events with hard leptons and missing
energy.
|
[
{
"created": "Fri, 15 Sep 2006 17:57:36 GMT",
"version": "v1"
},
{
"created": "Sat, 18 Nov 2006 22:39:14 GMT",
"version": "v2"
}
] |
2010-10-27
|
[
[
"Burdman",
"Gustavo",
""
],
[
"Chacko",
"Z.",
""
],
[
"Goh",
"Hock-Seng",
""
],
[
"Harnik",
"Roni",
""
]
] |
We present a new class of models that stabilize the weak scale against radiative corrections up to scales of order 5 TeV without large corrections to precision electroweak observables. In these `folded supersymmetric' theories the one loop quadratic divergences of the Standard Model Higgs field are cancelled by opposite spin partners, but the gauge quantum numbers of these new particles are in general different from those of the conventional superpartners. This class of models is built around the correspondence that exists in the large N limit between the correlation functions of supersymmetric theories and those of their non-supersymmetric orbifold daughters. By identifying the mechanism which underlies the cancellation of one loop quadratic divergences in these theories, we are able to construct simple extensions of the Standard Model which are radiatively stable at one loop. Ultraviolet completions of these theories can be obtained by imposing suitable boundary conditions on an appropriate supersymmetric higher dimensional theory compactified down to four dimensions. We construct a specific model based on these ideas which stabilizes the weak scale up to about 20 TeV and where the states which cancel the top loop are scalars not charged under Standard Model color. Its collider signatures are distinct from conventional supersymmetric theories and include characteristic events with hard leptons and missing energy.
|
hep-ph/0405061
|
Nita Sinha
|
Nita Sinha
|
Determining gamma using B->D^**K
|
7 pages, LaTex, 1 figure. Minor changes and some references added
|
Phys.Rev. D70 (2004) 097501
|
10.1103/PhysRevD.70.097501
| null |
hep-ph
| null |
We propose the use of B -->D^**K decay modes for a theoretically clean
determination of the weak phase gamma. The self tagging decays of the neutral
D^** mesons, makes a measurement of the b --> u\bar{c}s amplitude feasible.
This overcomes the problem with the Gronau-London-Wyler proposal. Even an upper
limit on the branching ratio for B^- -->bar{D}^{**0}K^- will place an
assumption free, lower bound on gamma.
|
[
{
"created": "Fri, 7 May 2004 09:09:22 GMT",
"version": "v1"
},
{
"created": "Fri, 14 May 2004 05:45:14 GMT",
"version": "v2"
}
] |
2009-11-10
|
[
[
"Sinha",
"Nita",
""
]
] |
We propose the use of B -->D^**K decay modes for a theoretically clean determination of the weak phase gamma. The self tagging decays of the neutral D^** mesons, makes a measurement of the b --> u\bar{c}s amplitude feasible. This overcomes the problem with the Gronau-London-Wyler proposal. Even an upper limit on the branching ratio for B^- -->bar{D}^{**0}K^- will place an assumption free, lower bound on gamma.
|
hep-ph/0604033
|
Fulvio Piccinini
|
C. M. Carloni Calame, M. Moretti, G. Montagna, O. Nicrosini, F.
Piccinini, A.D. Polosa
|
Impact of QED corrections to Higgs decay into four leptons at the LHC
|
5 pages, 5 figures, 1 table. Presented at HEP2005 July 21st-27th,
2005, Lisboa, Portugal and at RADCOR 2005, Shonan Village, October 2nd-7th,
2005, Japan
| null |
10.1016/j.nuclphysbps.2006.03.010
| null |
hep-ph
| null |
At the LHC a precise measurement of the Higgs boson mass (if discovered), at
the level of 0.1-1%, will be possible through the channel g g --> H --> 4l for
a wide range of Higgs mass values. To match such an accuracy, the systematic
effects induced by QED corrections need to be investigated. In the present
study the calculation of O(alpha) and higher order QED corrections is
illustrated as well as their impact on the Higgs mass determination, once
realistic event selection criteria for charged leptons and photons are
considered.
|
[
{
"created": "Tue, 4 Apr 2006 14:12:36 GMT",
"version": "v1"
}
] |
2009-11-11
|
[
[
"Calame",
"C. M. Carloni",
""
],
[
"Moretti",
"M.",
""
],
[
"Montagna",
"G.",
""
],
[
"Nicrosini",
"O.",
""
],
[
"Piccinini",
"F.",
""
],
[
"Polosa",
"A. D.",
""
]
] |
At the LHC a precise measurement of the Higgs boson mass (if discovered), at the level of 0.1-1%, will be possible through the channel g g --> H --> 4l for a wide range of Higgs mass values. To match such an accuracy, the systematic effects induced by QED corrections need to be investigated. In the present study the calculation of O(alpha) and higher order QED corrections is illustrated as well as their impact on the Higgs mass determination, once realistic event selection criteria for charged leptons and photons are considered.
|
hep-ph/9903464
|
Mario A. Serna
|
Alan H. Guth, Lisa Randall, and Mario Serna
|
Day-Night and Energy Dependence of MSW Solar Neutrinos for Maximal
Mixing
|
JHEP style, 22 pages, 7 figures. References added, and minor
rewording
|
JHEP 9908:018,1999
|
10.1088/1126-6708/1999/08/018
|
MIT-CTP-2841
|
hep-ph
| null |
It has been stated in the literature that the case of maximal mixing angle
for \nu_e leads to no day-night effect for solar neutrinos and an energy
independent flux suppression of 1/2. While the case of maximal mixing angle and
\Delta m^2 in the MSW range does lead to suppression of the electron neutrinos
reaching the earth from the sun by P_S=1/2, the situation is different for
neutrinos that have passed through the earth. We make the pedagogical point
that, just as with smaller mixing angles, the earth regenerates the |\nu_1>
state from the predominantly |\nu_2 > state reaching the earth, leading to
coherent interference effects. This regeneration can lead to a day-night effect
and an energy dependence of the suppression of solar electron neutrinos, even
for the case of maximal mixing. For large mixing angles, the energy dependence
of the day-night asymmetry depends heavily on Delta m^2. With a sufficiently
sensitive measurement of the day-night effect, this energy dependence could be
used to distinguish among the large mixing angle solutions of the solar
neutrino problem.
|
[
{
"created": "Wed, 24 Mar 1999 00:55:29 GMT",
"version": "v1"
},
{
"created": "Wed, 28 Apr 1999 23:02:29 GMT",
"version": "v2"
}
] |
2016-09-06
|
[
[
"Guth",
"Alan H.",
""
],
[
"Randall",
"Lisa",
""
],
[
"Serna",
"Mario",
""
]
] |
It has been stated in the literature that the case of maximal mixing angle for \nu_e leads to no day-night effect for solar neutrinos and an energy independent flux suppression of 1/2. While the case of maximal mixing angle and \Delta m^2 in the MSW range does lead to suppression of the electron neutrinos reaching the earth from the sun by P_S=1/2, the situation is different for neutrinos that have passed through the earth. We make the pedagogical point that, just as with smaller mixing angles, the earth regenerates the |\nu_1> state from the predominantly |\nu_2 > state reaching the earth, leading to coherent interference effects. This regeneration can lead to a day-night effect and an energy dependence of the suppression of solar electron neutrinos, even for the case of maximal mixing. For large mixing angles, the energy dependence of the day-night asymmetry depends heavily on Delta m^2. With a sufficiently sensitive measurement of the day-night effect, this energy dependence could be used to distinguish among the large mixing angle solutions of the solar neutrino problem.
|
hep-ph/0407129
|
Yurii V. Dumin
|
Yu.V. Dumin (Max-Planck-Institut, Dresden, Germany & University of
California, Los Angeles, USA), L.M. Svirskaya (Chelyabinsk State Pedagogical
University, Russia)
|
On the Efficiency of Topological Defect Formation in the Systems of
Various Size and (Quasi-) Dimensionality
|
REVTeX 4.0, 6 pages, 2 eps figures; LaTeX packages used: amsmath,
amssymb, graphicx, bm, dcolumn. Ver.2: the introductory part rewritten,
taking into account the recent experimental data; new references added.
Ver.3: the appendix added, explaining the details of calculations; one
reference added; some stylistic changes made
| null | null | null |
hep-ph
| null |
The experiments on verification of the Kibble-Zurek mechanism showed that
topological defects are formed most efficiently in the systems of small size or
low (quasi-)dimensionality, whereas in the macroscopic two- and
three-dimensional samples a concentration of the defects, as a rule, is
strongly suppressed. A reason for universality of such behavior can be revealed
by considering a strongly-nonequilibrium symmetry-breaking phase transition in
the simplest phi-4 field model. It is shown that the resulting distribution of
the defects (domain walls) is formally reduced to the well-known Ising model,
whose behavior changes dramatically in passing from a finite to infinite size
of the system and from the low (D=1) to higher (D>=2) dimensionality.
|
[
{
"created": "Sun, 11 Jul 2004 03:52:48 GMT",
"version": "v1"
},
{
"created": "Tue, 15 Feb 2005 13:18:17 GMT",
"version": "v2"
},
{
"created": "Tue, 29 Mar 2005 05:15:47 GMT",
"version": "v3"
}
] |
2007-05-23
|
[
[
"Dumin",
"Yu. V.",
"",
"Max-Planck-Institut, Dresden, Germany & University of\n California, Los Angeles, USA"
],
[
"Svirskaya",
"L. M.",
"",
"Chelyabinsk State Pedagogical\n University, Russia"
]
] |
The experiments on verification of the Kibble-Zurek mechanism showed that topological defects are formed most efficiently in the systems of small size or low (quasi-)dimensionality, whereas in the macroscopic two- and three-dimensional samples a concentration of the defects, as a rule, is strongly suppressed. A reason for universality of such behavior can be revealed by considering a strongly-nonequilibrium symmetry-breaking phase transition in the simplest phi-4 field model. It is shown that the resulting distribution of the defects (domain walls) is formally reduced to the well-known Ising model, whose behavior changes dramatically in passing from a finite to infinite size of the system and from the low (D=1) to higher (D>=2) dimensionality.
|
2401.05173
|
Stefano Di Noi
|
Stefano Di Noi and Ramona Gr\"ober
|
Higgs probes of top contact interactions and their interplay with Higgs
self-coupling
|
Proceedings to "The Eleventh Annual Conference on Large Hadron
Collider Physics" (LHCP2023), 22-26 May 2023, Belgrade, Serbia
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We present a method which relies on loop contributions from four-top SMEFT
operators to single Higgs observables to contrain their Wilson coefficients.
Such loop-induced terms have a non-trivial interplay with the extraction of the
trilinear Higgs coupling. We show that this strategy can, for some operators,
lead to more stringent bounds than direct measurement via top quark data.
Finally, we mention some recent developements in the treatment of $\gamma_5$ in
dimensional regularisation in the context of the SMEFT.
|
[
{
"created": "Wed, 10 Jan 2024 14:10:24 GMT",
"version": "v1"
}
] |
2024-01-11
|
[
[
"Di Noi",
"Stefano",
""
],
[
"Gröber",
"Ramona",
""
]
] |
We present a method which relies on loop contributions from four-top SMEFT operators to single Higgs observables to contrain their Wilson coefficients. Such loop-induced terms have a non-trivial interplay with the extraction of the trilinear Higgs coupling. We show that this strategy can, for some operators, lead to more stringent bounds than direct measurement via top quark data. Finally, we mention some recent developements in the treatment of $\gamma_5$ in dimensional regularisation in the context of the SMEFT.
|
2307.16793
|
Joshua Martin
|
Joshua D. Martin, Duff Neill, A. Roggero, Huaiyu Duan, and J. Carlson
|
Equilibration of quantum many-body fast neutrino flavor oscillations
|
16 pages, 8 figures, 1 appendix
| null | null |
LA-UR-23-28635
|
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Neutrino gases are expected to form in high density astrophysical
environments, and accurately modeling their flavor evolution is critical to
understanding such environments. In this work we study a simplified model of
such a dense neutrino gas in the regime for which neutrino-neutrino coherent
forward scattering is the dominant mechanism contributing to the flavor
evolution. We show evidence that the generic potential induced by this effect
is non-integrable and that the statistics of its energy level spaces are in
good agreement with the Wigner surmise. We also find that individual neutrinos
rapidly entangle with all of the others present which results in an
equilibration of the flavor content of individual neutrinos. We show that the
average neutrino flavor content can be predicted utilizing a thermodynamic
partition function. A random phase approximation to the evolution gives a
simple picture of this equilibration. In the case of neutrinos and
antineutrinos, processes like $\nu_e {\bar{\nu}}_e \leftrightarrows \nu_\mu
{\bar{\nu}_\mu} $ yield a rapid equilibrium satisfying $n( \nu_e) n({\bar
\nu}_e) = n( \nu_\mu) n({\bar \nu}_\mu) = n( \nu_\tau) n({\bar \nu}_\tau)$ in
addition to the standard lepton number conservation in regimes where
off-diagonal vacuum oscillations are small compared to $\nu-\nu$ interactions.
|
[
{
"created": "Mon, 31 Jul 2023 15:59:01 GMT",
"version": "v1"
},
{
"created": "Mon, 8 Jan 2024 18:57:43 GMT",
"version": "v2"
}
] |
2024-01-09
|
[
[
"Martin",
"Joshua D.",
""
],
[
"Neill",
"Duff",
""
],
[
"Roggero",
"A.",
""
],
[
"Duan",
"Huaiyu",
""
],
[
"Carlson",
"J.",
""
]
] |
Neutrino gases are expected to form in high density astrophysical environments, and accurately modeling their flavor evolution is critical to understanding such environments. In this work we study a simplified model of such a dense neutrino gas in the regime for which neutrino-neutrino coherent forward scattering is the dominant mechanism contributing to the flavor evolution. We show evidence that the generic potential induced by this effect is non-integrable and that the statistics of its energy level spaces are in good agreement with the Wigner surmise. We also find that individual neutrinos rapidly entangle with all of the others present which results in an equilibration of the flavor content of individual neutrinos. We show that the average neutrino flavor content can be predicted utilizing a thermodynamic partition function. A random phase approximation to the evolution gives a simple picture of this equilibration. In the case of neutrinos and antineutrinos, processes like $\nu_e {\bar{\nu}}_e \leftrightarrows \nu_\mu {\bar{\nu}_\mu} $ yield a rapid equilibrium satisfying $n( \nu_e) n({\bar \nu}_e) = n( \nu_\mu) n({\bar \nu}_\mu) = n( \nu_\tau) n({\bar \nu}_\tau)$ in addition to the standard lepton number conservation in regimes where off-diagonal vacuum oscillations are small compared to $\nu-\nu$ interactions.
|
1710.07254
|
Ernesto Arganda
|
Ernesto Arganda, J. Lorenzo D\'iaz-Cruz, Nicol\'as Mileo, Roberto A.
Morales, Alejandro Szynkman
|
Search strategies for pair production of heavy Higgs bosons decaying
invisibly at the LHC
|
22 pages, 11 tables, 2 figures. This version v2 matches the
manuscript published in NPB
|
Nucl. Phys. B 929 (2018) 171-192
|
10.1016/j.nuclphysb.2018.02.004
|
CIFFU-17-06
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The search for heavy Higgs bosons at the LHC represents an intense
experimental program, carried out by the ATLAS and CMS collaborations, which
includes the hunt for invisible Higgs decays and dark matter candidates. No
significant deviations from the SM backgrounds have been observed in any of
these searches, imposing significant constraints on the parameter space of
different new physics models with an extended Higgs sector. Here we discuss an
alternative search strategy for heavy Higgs bosons decaying invisibly at the
LHC, focusing on the pair production of a heavy scalar $H$ together with a
pseudoscalar $A$, through the production mode $q \bar q \to Z^\ast \to HA$. We
identify as the most promising signal the final state made up of $4b +
E_T^\text{miss}$, coming from the heavy scalar decay mode $H \to hh \to b \bar
b b \bar b$, with $h$ being the discovered SM-like Higgs boson with $m_h=125$
GeV, together with the invisible channel of the pseudoscalar. We work within
the context of simplified MSSM scenarios that contain quite heavy sfermions of
most types with ${\cal O}(10)$ TeV masses, while the stops are heavy enough to
reproduce the 125 GeV mass for the lightest SM-like Higgs boson. By contrast,
the gauginos/higgsinos and the heavy MSSM Higgs bosons have masses near the EW
scale. Our search strategies, for a LHC center-of-mass energy of $\sqrt{s} =$
14 TeV, allow us to obtain statistical significances of the signal over the SM
backgrounds with values up to $\sim$ 1.6$\sigma$ and $\sim$ 3$\sigma$, for
total integrated luminosities of 300 fb$^{-1}$ and 1000 fb$^{-1}$,
respectively.
|
[
{
"created": "Thu, 19 Oct 2017 17:24:28 GMT",
"version": "v1"
},
{
"created": "Wed, 7 Mar 2018 13:50:23 GMT",
"version": "v2"
}
] |
2018-03-08
|
[
[
"Arganda",
"Ernesto",
""
],
[
"Díaz-Cruz",
"J. Lorenzo",
""
],
[
"Mileo",
"Nicolás",
""
],
[
"Morales",
"Roberto A.",
""
],
[
"Szynkman",
"Alejandro",
""
]
] |
The search for heavy Higgs bosons at the LHC represents an intense experimental program, carried out by the ATLAS and CMS collaborations, which includes the hunt for invisible Higgs decays and dark matter candidates. No significant deviations from the SM backgrounds have been observed in any of these searches, imposing significant constraints on the parameter space of different new physics models with an extended Higgs sector. Here we discuss an alternative search strategy for heavy Higgs bosons decaying invisibly at the LHC, focusing on the pair production of a heavy scalar $H$ together with a pseudoscalar $A$, through the production mode $q \bar q \to Z^\ast \to HA$. We identify as the most promising signal the final state made up of $4b + E_T^\text{miss}$, coming from the heavy scalar decay mode $H \to hh \to b \bar b b \bar b$, with $h$ being the discovered SM-like Higgs boson with $m_h=125$ GeV, together with the invisible channel of the pseudoscalar. We work within the context of simplified MSSM scenarios that contain quite heavy sfermions of most types with ${\cal O}(10)$ TeV masses, while the stops are heavy enough to reproduce the 125 GeV mass for the lightest SM-like Higgs boson. By contrast, the gauginos/higgsinos and the heavy MSSM Higgs bosons have masses near the EW scale. Our search strategies, for a LHC center-of-mass energy of $\sqrt{s} =$ 14 TeV, allow us to obtain statistical significances of the signal over the SM backgrounds with values up to $\sim$ 1.6$\sigma$ and $\sim$ 3$\sigma$, for total integrated luminosities of 300 fb$^{-1}$ and 1000 fb$^{-1}$, respectively.
|
hep-ph/0508258
|
Mahiko Suzuki
|
Mahiko Suzuki
|
The X(3872) boson: Molecule or charmonium
|
A few sentences of comment are added. One minor rewording in the
Introduction. Two trivial typos are corrected
|
Phys.Rev.D72:114013,2005
|
10.1103/PhysRevD.72.114013
| null |
hep-ph
| null |
It has been argued that the mystery boson X(3872) is a molecule state
consisting of primarily D0-D0*bar + D0bar-D*0. In contrast, apparent puzzles
and potential difficulties have been pointed out for the charmonium assignment
of X(3872). We examine several aspects of these alternatives by
semiquantitative methods since quantitatively accurate results are often hard
to reach on them. We find that some of the observed properties of X(3872), in
particualr, the binding and the production rates are incompatible with the
molecule interpretation. Despite puzzles and obstacles, X(3872) may fit more
likely to the excited triplet P_1 charmonium than to the molecule after mixing
of cc-bar with DD*-bar +Dbar-D* is taken into account. One simple experimental
test is pointed out for distinguishing between a charmonium and an
isospin-mixed molecule in the neutral B decay.
|
[
{
"created": "Wed, 24 Aug 2005 18:42:44 GMT",
"version": "v1"
},
{
"created": "Fri, 9 Sep 2005 16:16:12 GMT",
"version": "v2"
},
{
"created": "Sat, 19 Nov 2005 22:57:08 GMT",
"version": "v3"
}
] |
2008-11-26
|
[
[
"Suzuki",
"Mahiko",
""
]
] |
It has been argued that the mystery boson X(3872) is a molecule state consisting of primarily D0-D0*bar + D0bar-D*0. In contrast, apparent puzzles and potential difficulties have been pointed out for the charmonium assignment of X(3872). We examine several aspects of these alternatives by semiquantitative methods since quantitatively accurate results are often hard to reach on them. We find that some of the observed properties of X(3872), in particualr, the binding and the production rates are incompatible with the molecule interpretation. Despite puzzles and obstacles, X(3872) may fit more likely to the excited triplet P_1 charmonium than to the molecule after mixing of cc-bar with DD*-bar +Dbar-D* is taken into account. One simple experimental test is pointed out for distinguishing between a charmonium and an isospin-mixed molecule in the neutral B decay.
|
hep-ph/9910545
|
Andreas Vogt
|
A. Vogt (Leiden University)
|
On soft gluon effects in deep-inelastic structure functions
|
10 pages, 3 figures, misprints in third line of eq. (15) corrected
|
Phys.Lett. B471 (1999) 97-102
|
10.1016/S0370-2693(99)01325-8
|
INLO-PUB 19/99
|
hep-ph
| null |
The behaviour of the quark coefficient functions in deep-inelastic scattering
is investigated for large values of the Bjorken variable x. By combining
results of soft-gluon resummation and fixed-order calculations, we determine
the coefficients of the four leading large-x logarithms, alpha_s^k
[{ln(1-x)}^{2k-l}/(1-x)]_+, l = 1, ...4, to all orders in the strong coupling
constant alpha_s. This result includes two more terms for the three-loop
coefficient functions than previously specified in the literature. The effect
of the fifth logarithmic contribution is approximately evaluated. The terms
derived here are required, but also seem to be sufficient, for a reliable
representation of the coefficient functions at large x.
|
[
{
"created": "Fri, 29 Oct 1999 19:48:56 GMT",
"version": "v1"
},
{
"created": "Sat, 14 Oct 2000 13:48:46 GMT",
"version": "v2"
}
] |
2009-10-31
|
[
[
"Vogt",
"A.",
"",
"Leiden University"
]
] |
The behaviour of the quark coefficient functions in deep-inelastic scattering is investigated for large values of the Bjorken variable x. By combining results of soft-gluon resummation and fixed-order calculations, we determine the coefficients of the four leading large-x logarithms, alpha_s^k [{ln(1-x)}^{2k-l}/(1-x)]_+, l = 1, ...4, to all orders in the strong coupling constant alpha_s. This result includes two more terms for the three-loop coefficient functions than previously specified in the literature. The effect of the fifth logarithmic contribution is approximately evaluated. The terms derived here are required, but also seem to be sufficient, for a reliable representation of the coefficient functions at large x.
|
hep-ph/0610038
|
Piyush Kumar
|
Gordon L. Kane, Piyush Kumar and Jing Shao
|
LHC String Phenomenology
|
50 Pages, 13 Figures, 3 Tables, v2: minor changes, references added
|
J.Phys.G34:1993-2036,2007
|
10.1088/0954-3899/34/9/011
| null |
hep-ph hep-ex hep-th
| null |
We argue that it is possible to address the deeper LHC Inverse Problem, to
gain insight into the underlying theory from LHC signatures of new physics. We
propose a technique which may allow us to distinguish among, and favor or
disfavor, various classes of underlying theoretical constructions using
(assumed) new physics signals at the LHC. We think that this can be done with
limited data $(5-10 fb^{-1})$, and improved with more data. This is because of
two reasons -- a) it is possible in many cases to reliably go from
(semi)realistic microscopic string construction to the space of experimental
observables, say, LHC signatures. b) The patterns of signatures at the LHC are
sensitive to the structure of the underlying theoretical constructions. We
illustrate our approach by analyzing two promising classes of string
compactifications along with six other string-motivated constructions. Even
though these constructions are not complete, they illustrate the point we want
to emphasize. We think that using this technique effectively over time can
eventually help us to meaningfully connect experimental data to microscopic
theory.
|
[
{
"created": "Tue, 3 Oct 2006 19:54:49 GMT",
"version": "v1"
},
{
"created": "Tue, 5 Jun 2007 13:38:19 GMT",
"version": "v2"
}
] |
2008-11-26
|
[
[
"Kane",
"Gordon L.",
""
],
[
"Kumar",
"Piyush",
""
],
[
"Shao",
"Jing",
""
]
] |
We argue that it is possible to address the deeper LHC Inverse Problem, to gain insight into the underlying theory from LHC signatures of new physics. We propose a technique which may allow us to distinguish among, and favor or disfavor, various classes of underlying theoretical constructions using (assumed) new physics signals at the LHC. We think that this can be done with limited data $(5-10 fb^{-1})$, and improved with more data. This is because of two reasons -- a) it is possible in many cases to reliably go from (semi)realistic microscopic string construction to the space of experimental observables, say, LHC signatures. b) The patterns of signatures at the LHC are sensitive to the structure of the underlying theoretical constructions. We illustrate our approach by analyzing two promising classes of string compactifications along with six other string-motivated constructions. Even though these constructions are not complete, they illustrate the point we want to emphasize. We think that using this technique effectively over time can eventually help us to meaningfully connect experimental data to microscopic theory.
|
1912.13022
|
Sayan Dasgupta
|
Sayan Dasgupta, Santosh Kumar Rai, Tirtha Sankar Ray
|
Impact of a colored vector resonance on the collider constraints for
top-like top partner
|
Extensive changes in text, Matches published version
|
Phys. Rev. D 102, 115014 (2020)
|
10.1103/PhysRevD.102.115014
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In this work we reappraise the collider constraints from leptonic final
states on the vectorlike colored top partners taking into account the impact of
exotic colored vector resonances. These colored states are intrinsic to a broad
class of models that employ a strongly interacting sector to drive electroweak
symmetry breaking. We translate the recent results in the {\sl monolepton +
jets} channel as reported by CMS with an integrated luminosity of 35.8
fb$^{-1}$, and {\sl dilepton + jets} and {\sl trilepton + jets} channels as
reported by ATLAS with an integrated luminosity of 36.1 fb$^{-1}$ to constrain
the parameter space of these class of models. We also comment on the impact and
modification of the derived constraints due to the expected fatness of the
colored vector resonance, when accounted for beyond the narrow-width
approximation by simulating the full one-particle irreducible resummed
propagator.
|
[
{
"created": "Mon, 30 Dec 2019 17:33:45 GMT",
"version": "v1"
},
{
"created": "Tue, 1 Dec 2020 10:55:45 GMT",
"version": "v2"
}
] |
2020-12-09
|
[
[
"Dasgupta",
"Sayan",
""
],
[
"Rai",
"Santosh Kumar",
""
],
[
"Ray",
"Tirtha Sankar",
""
]
] |
In this work we reappraise the collider constraints from leptonic final states on the vectorlike colored top partners taking into account the impact of exotic colored vector resonances. These colored states are intrinsic to a broad class of models that employ a strongly interacting sector to drive electroweak symmetry breaking. We translate the recent results in the {\sl monolepton + jets} channel as reported by CMS with an integrated luminosity of 35.8 fb$^{-1}$, and {\sl dilepton + jets} and {\sl trilepton + jets} channels as reported by ATLAS with an integrated luminosity of 36.1 fb$^{-1}$ to constrain the parameter space of these class of models. We also comment on the impact and modification of the derived constraints due to the expected fatness of the colored vector resonance, when accounted for beyond the narrow-width approximation by simulating the full one-particle irreducible resummed propagator.
|
hep-ph/0210448
|
Shufang Su
|
Shufang Su
|
Single Heavy MSSM Higgs Production at e+e- Linear Collider
|
6 pages, talk given at SUSY02, the 10th International Conference on
Supersymmetry and Unification of Fundamental Interations, June 17-23, 2002,
DESY Hamburg
| null | null | null |
hep-ph
| null |
We briefly review the single heavy Higgs production at high energy e+e-
linear collider, \gamma\gamma collider and e-\gamma collider. We present the
recent results for e+e- --> W^{\pm}H^{\mp} in the Minimal Supersymmetric
Standard Model and preliminary results for e+e- --> \nu \bar\nu A^0.
|
[
{
"created": "Thu, 31 Oct 2002 19:28:54 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Su",
"Shufang",
""
]
] |
We briefly review the single heavy Higgs production at high energy e+e- linear collider, \gamma\gamma collider and e-\gamma collider. We present the recent results for e+e- --> W^{\pm}H^{\mp} in the Minimal Supersymmetric Standard Model and preliminary results for e+e- --> \nu \bar\nu A^0.
|
hep-ph/0407015
|
Abdelkader-Salim Safir
|
A. Salim Safir (Munich U.)
|
Exploring the Unitarity Triangle through CP violation observables in
$B_s \to K^+ K^-$
|
22 pages, 6 figures, typos corrected, reference and some remarks
added
|
JHEP 0409:053,2004
|
10.1088/1126-6708/2004/09/053
|
LMU 05/04
|
hep-ph
| null |
We discuss the determination of the CKM parameters from the forthcoming $CP$
violation observables in $B_s \to K^+ K^-$ decays. Combining the information on
mixing induced CP violation in $B_s \to K^+ K^-$, with the $B_d \to J/\psi K_s$
precision observable $\sin 2\beta$ and the $B^0_s$--$\bar{B^0_s}$ mixing phase
$\phi_s$, we propose a determination of the unitarity triangle $(\bar\rho,
\bar\eta)$. Computing the penguin parameters $(r, \theta)$ within QCD
factorization yield precise determination of $(\bar\rho, \bar\eta)$, reflected
by a weak dependence on the $\theta$ which is shown as a second order effect.
The impact of the direct CP violation observable $C_{KK}$ on the penguin
parameters are investigated and a lower bound on $C_{KK}$ is extracted. We also
discuss the effect of the $B^0_s$--$\bar{B^0_s}$ new physics mixing phase on
the penguin parameters $(r, \theta)$ and $S_{KK}$. Using the SU(3)-flavour
symmetry argument and the current $B$-factories data provided by the $B_d \to
\pi^+ \pi^-$ modes, we complement the $B_s \to K^+ K^-$ CP-violating
observables in a variety of ways, in particular we find that $S_{KK}>0$.
Finally we analyze systematically the SU(3)-symmetry breaking factor within QCD
factorization.
|
[
{
"created": "Thu, 1 Jul 2004 16:39:07 GMT",
"version": "v1"
},
{
"created": "Wed, 14 Jul 2004 17:39:17 GMT",
"version": "v2"
}
] |
2010-11-23
|
[
[
"Safir",
"A. Salim",
"",
"Munich U."
]
] |
We discuss the determination of the CKM parameters from the forthcoming $CP$ violation observables in $B_s \to K^+ K^-$ decays. Combining the information on mixing induced CP violation in $B_s \to K^+ K^-$, with the $B_d \to J/\psi K_s$ precision observable $\sin 2\beta$ and the $B^0_s$--$\bar{B^0_s}$ mixing phase $\phi_s$, we propose a determination of the unitarity triangle $(\bar\rho, \bar\eta)$. Computing the penguin parameters $(r, \theta)$ within QCD factorization yield precise determination of $(\bar\rho, \bar\eta)$, reflected by a weak dependence on the $\theta$ which is shown as a second order effect. The impact of the direct CP violation observable $C_{KK}$ on the penguin parameters are investigated and a lower bound on $C_{KK}$ is extracted. We also discuss the effect of the $B^0_s$--$\bar{B^0_s}$ new physics mixing phase on the penguin parameters $(r, \theta)$ and $S_{KK}$. Using the SU(3)-flavour symmetry argument and the current $B$-factories data provided by the $B_d \to \pi^+ \pi^-$ modes, we complement the $B_s \to K^+ K^-$ CP-violating observables in a variety of ways, in particular we find that $S_{KK}>0$. Finally we analyze systematically the SU(3)-symmetry breaking factor within QCD factorization.
|
1111.5751
|
Daniel Grossman
|
Daniel Grossman, Yosef Nir
|
Probing the Seesaw and Gauge Mediation Scales with BR(\mu\to e\gamma)
and |U_{e3}|
|
6 pages, 1 figure, v2: References added
| null |
10.1103/PhysRevD.85.055004
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The new MEG bound on BR(\mu\to e\gamma) provides the strongest upper bound on
the scale of gauge mediation of supersymmetry breaking. If, in the future, this
decay is observed by MEG, the mediation scale will become known to within one
order of magnitude, and the seesaw scale will be constrained. In such a case,
contributions from Planck mediated supersymmetry breaking are likely to be
non-negligible, and an interpretation in terms of purely seesaw parameters will
be impossible. The recent evidence for |U_{e3}|~0.15 further sharpens the
predictions of gauge mediated supersymmetry breaking.
|
[
{
"created": "Thu, 24 Nov 2011 13:19:06 GMT",
"version": "v1"
},
{
"created": "Sun, 25 Dec 2011 17:14:53 GMT",
"version": "v2"
}
] |
2013-05-30
|
[
[
"Grossman",
"Daniel",
""
],
[
"Nir",
"Yosef",
""
]
] |
The new MEG bound on BR(\mu\to e\gamma) provides the strongest upper bound on the scale of gauge mediation of supersymmetry breaking. If, in the future, this decay is observed by MEG, the mediation scale will become known to within one order of magnitude, and the seesaw scale will be constrained. In such a case, contributions from Planck mediated supersymmetry breaking are likely to be non-negligible, and an interpretation in terms of purely seesaw parameters will be impossible. The recent evidence for |U_{e3}|~0.15 further sharpens the predictions of gauge mediated supersymmetry breaking.
|
2310.02711
|
Raghunath Sahoo
|
Kangkan Goswami, Dushmanta Sahu, Jayanta Dey, Raghunath Sahoo, and
Reinhard Stock
|
Anisotropy of magnetized quark matter
|
Same as the published version in Phys. Rev. D
|
Phys. Rev. D 109, 074012 (2024)
|
10.1103/PhysRevD.109.074012
| null |
hep-ph hep-ex nucl-ex nucl-th
|
http://creativecommons.org/licenses/by-sa/4.0/
|
Strong transient magnetic fields are generated in non-central relativistic
heavy-ion collisions. These fields induce anisotropy within the strongly
interacting medium that, in principle, can affect the thermodynamic properties
of the medium. We use the Polyakov loop extended Nambu Jona-Lasinio model to
study the quark matter subjected to an external magnetic field at vanishing
baryon chemical potential ($\mu_{B}$). We have estimated the degree of
anisotropy in the speed of sound and isothermal compressibility within the
magnetized quark matter as a function of temperature ($T$) and magnetic field
($eB$). This study helps us to understand the extent of directionality
generated in the initial stages of non-central collisions while giving us
useful information about the system.
|
[
{
"created": "Wed, 4 Oct 2023 10:28:11 GMT",
"version": "v1"
},
{
"created": "Mon, 15 Apr 2024 14:56:14 GMT",
"version": "v2"
}
] |
2024-04-16
|
[
[
"Goswami",
"Kangkan",
""
],
[
"Sahu",
"Dushmanta",
""
],
[
"Dey",
"Jayanta",
""
],
[
"Sahoo",
"Raghunath",
""
],
[
"Stock",
"Reinhard",
""
]
] |
Strong transient magnetic fields are generated in non-central relativistic heavy-ion collisions. These fields induce anisotropy within the strongly interacting medium that, in principle, can affect the thermodynamic properties of the medium. We use the Polyakov loop extended Nambu Jona-Lasinio model to study the quark matter subjected to an external magnetic field at vanishing baryon chemical potential ($\mu_{B}$). We have estimated the degree of anisotropy in the speed of sound and isothermal compressibility within the magnetized quark matter as a function of temperature ($T$) and magnetic field ($eB$). This study helps us to understand the extent of directionality generated in the initial stages of non-central collisions while giving us useful information about the system.
|
0712.3163
|
Stefan Dittmaier
|
Stefan Dittmaier, Stefan Kallweit and Peter Uwer
|
NLO QCD corrections to pp->WW+jet+X
|
6 pages, latex, 4 ps figures, to appear in the proceedings of the
"8th International Symposium on Radiative Corrections (RADCOR07)", Florence,
Italy, October 1-5, 2007
|
PoSRADCOR2007:009,2007
| null |
MPP-2007-193, SFB/CPP-07-87, UWThPh-2007-30
|
hep-ph
| null |
We report on the calculation of the next-to-leading order QCD corrections to
the production of W-boson pairs in association with a hard jet at hadron
colliders, which is an important source of background for Higgs and new-physics
searches. If a veto against the emission of a second hard jet is applied, the
corrections stabilize the leading-order prediction for the cross section
considerably.
|
[
{
"created": "Wed, 19 Dec 2007 11:36:58 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Dittmaier",
"Stefan",
""
],
[
"Kallweit",
"Stefan",
""
],
[
"Uwer",
"Peter",
""
]
] |
We report on the calculation of the next-to-leading order QCD corrections to the production of W-boson pairs in association with a hard jet at hadron colliders, which is an important source of background for Higgs and new-physics searches. If a veto against the emission of a second hard jet is applied, the corrections stabilize the leading-order prediction for the cross section considerably.
|
2201.08403
|
Lucian Harland-Lang
|
S. Bailey, L. A. Harland-Lang
|
Modelling $W^+ W^-$ production with rapidity gaps at the LHC
|
43 pages, 12 figures, 8 tables
| null |
10.1103/PhysRevD.105.093010
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We present a new calculation of $W^+ W^-$ production in the semi-exclusive
channel, that is either with intact outgoing protons or rapidity gaps present
in the final state, and with no colour flow between the colliding protons. This
study provides the first complete prediction of the $W^+ W^-$ semi-exclusive
cross section, as well as the breakdown between elastic and proton dissociative
channels. It combines the structure function calculation for a precise
modelling of the region of low momentum transfers with a parton-level
calculation in the region of high momentum transfers. The survival factor
probability of no additional proton-proton interactions is fully accounted for,
including its kinematic and process dependence. We analyse in detail the role
that the pure photon-initiated ($\gamma\gamma \to W^+ W^-$) subprocess plays, a
comparison that is only viable by working in the electroweak axial gauge. In
this way, we find that the dominance of this is not complete in the proton
dissociative cases, although once $Z$-initiated production is included a
significantly better matching to the complete calculation is achieved. A direct
consequence of this is that the relative elastic, single and double
dissociative fractions are in general different in comparison to the case of
lepton pair production. We present a direct comparison to the recent ATLAS data
on semi-exclusive $W^+ W^-$ production, finding excellent agreement within
uncertainties. Our calculation is provided in the publicly available SuperChic
4.1 Monte Carlo (MC) generator, and can be passed to a general purpose MC for
showering and hadronization of the final state.
|
[
{
"created": "Thu, 20 Jan 2022 19:00:04 GMT",
"version": "v1"
}
] |
2022-06-01
|
[
[
"Bailey",
"S.",
""
],
[
"Harland-Lang",
"L. A.",
""
]
] |
We present a new calculation of $W^+ W^-$ production in the semi-exclusive channel, that is either with intact outgoing protons or rapidity gaps present in the final state, and with no colour flow between the colliding protons. This study provides the first complete prediction of the $W^+ W^-$ semi-exclusive cross section, as well as the breakdown between elastic and proton dissociative channels. It combines the structure function calculation for a precise modelling of the region of low momentum transfers with a parton-level calculation in the region of high momentum transfers. The survival factor probability of no additional proton-proton interactions is fully accounted for, including its kinematic and process dependence. We analyse in detail the role that the pure photon-initiated ($\gamma\gamma \to W^+ W^-$) subprocess plays, a comparison that is only viable by working in the electroweak axial gauge. In this way, we find that the dominance of this is not complete in the proton dissociative cases, although once $Z$-initiated production is included a significantly better matching to the complete calculation is achieved. A direct consequence of this is that the relative elastic, single and double dissociative fractions are in general different in comparison to the case of lepton pair production. We present a direct comparison to the recent ATLAS data on semi-exclusive $W^+ W^-$ production, finding excellent agreement within uncertainties. Our calculation is provided in the publicly available SuperChic 4.1 Monte Carlo (MC) generator, and can be passed to a general purpose MC for showering and hadronization of the final state.
|
hep-ph/9812377
|
Will Loinaz
|
Will Loinaz and Tatsu Takeuchi (Virginia Tech)
|
Constraints on Topcolor Assisted Technicolor Models from Vertex
Corrections
|
16 pages, 2 figures
|
Phys. Rev. D 60, 015005 (1999)
|
10.1103/PhysRevD.60.015005
|
VPI-IPPAP-98-7
|
hep-ph
| null |
We use the LEP/SLD data to place constraints on Topcolor Assisted Technicolor
Models. We find that due to a large negative shift in R_b induced by charged
top-pion exchange, it is difficult to make the models compatible with
experiment.
|
[
{
"created": "Tue, 15 Dec 1998 22:13:31 GMT",
"version": "v1"
}
] |
2016-08-25
|
[
[
"Loinaz",
"Will",
"",
"Virginia Tech"
],
[
"Takeuchi",
"Tatsu",
"",
"Virginia Tech"
]
] |
We use the LEP/SLD data to place constraints on Topcolor Assisted Technicolor Models. We find that due to a large negative shift in R_b induced by charged top-pion exchange, it is difficult to make the models compatible with experiment.
|
2204.12325
|
Kei Yamamoto
|
Tatsuo Kobayashi, Hajime Otsuka, Morimitsu Tanimoto, Kei Yamamoto
|
Lepton flavor violation, lepton $(g-2)_{\mu,\,e}$ and electron EDM in
the modular symmetry
|
33 pages, references added
| null |
10.1007/JHEP08(2022)013
| null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
We study the lepton flavor violation (LFV), the leptonic magnetic moments
$(g-2)_{\mu,\,e} $ and the electric dipole moment (EDM) of the electron in the
Standard-Model Effective Field Theory with the $\Gamma_N$ modular flavor
symmetry. We employ the stringy Ansatz on coupling structure that 4-point
couplings of matter fields are written by a product of 3-point couplings of
matter fields. We take the level 3 finite modular group, $\Gamma_3$ for the
flavor symmetry, and discuss the dipole operators at nearby fixed point
$\tau=i$, where observed lepton masses and mixing angles are well reproduced.
Suppose the anomaly of the anomalous magnetic moment of the muon to be evidence
of the new physics (NP), we have related it with $(g-2)_{e}$, LFV decays, and
the electron EDM. It is found that the NP contribution to $(g-2)_{e}$ is
proportional to the lepton masses squared likewise the naive scaling. We also
discuss the correlations among the LFV processes $\mu\to e\gamma$, $\tau\to
\mu\gamma$ and $\tau\to e\gamma$, which are testable in the future. The
electron EDM requires the tiny imaginary part of the relevant Wilson
coefficient in the basis of real positive charged lepton masses, which is
related to the $\mu\to e\gamma$ transition in our framework.
|
[
{
"created": "Tue, 26 Apr 2022 14:09:02 GMT",
"version": "v1"
},
{
"created": "Wed, 4 May 2022 15:01:38 GMT",
"version": "v2"
}
] |
2022-08-24
|
[
[
"Kobayashi",
"Tatsuo",
""
],
[
"Otsuka",
"Hajime",
""
],
[
"Tanimoto",
"Morimitsu",
""
],
[
"Yamamoto",
"Kei",
""
]
] |
We study the lepton flavor violation (LFV), the leptonic magnetic moments $(g-2)_{\mu,\,e} $ and the electric dipole moment (EDM) of the electron in the Standard-Model Effective Field Theory with the $\Gamma_N$ modular flavor symmetry. We employ the stringy Ansatz on coupling structure that 4-point couplings of matter fields are written by a product of 3-point couplings of matter fields. We take the level 3 finite modular group, $\Gamma_3$ for the flavor symmetry, and discuss the dipole operators at nearby fixed point $\tau=i$, where observed lepton masses and mixing angles are well reproduced. Suppose the anomaly of the anomalous magnetic moment of the muon to be evidence of the new physics (NP), we have related it with $(g-2)_{e}$, LFV decays, and the electron EDM. It is found that the NP contribution to $(g-2)_{e}$ is proportional to the lepton masses squared likewise the naive scaling. We also discuss the correlations among the LFV processes $\mu\to e\gamma$, $\tau\to \mu\gamma$ and $\tau\to e\gamma$, which are testable in the future. The electron EDM requires the tiny imaginary part of the relevant Wilson coefficient in the basis of real positive charged lepton masses, which is related to the $\mu\to e\gamma$ transition in our framework.
|
hep-ph/0307001
|
Juan Antonio Aguilar Saavedra
|
J. A. Aguilar-Saavedra, A. M. Teixeira
|
Testing the Majorana nature of neutralinos in supersymmetric theories
|
LaTeX, 35 pages, 23 PS figures. Some clarifications, comments and
references added, typos corrected. Final version to appear in Nucl. Phys. B
|
Nucl.Phys. B675 (2003) 70-98
|
10.1016/j.nuclphysb.2003.09.055
|
FTUAM 03/10,FT-UAM/CSIC-03-22
|
hep-ph
| null |
We discuss selectron pair production in e- e- scattering. These processes can
only occur via t-channel neutralino exchange, provided that the neutralinos are
Majorana fermions. We concentrate on the processes e- e- -> e^~_L e^~_L,e^~_R
e^~_R -> e- X^~_1^0 e- X^~_2^0 -> e- X^~_1^0 e- X^~_1^0 f f, in which a
complete determination of the final state momenta is possible without using the
selectron masses as input. The experimental reconstruction of the selectron
masses in this decay channel provides clear evidence of the Majorana character
of the neutralinos, which is confirmed by the analysis of the electron energy
spectrum.
|
[
{
"created": "Mon, 30 Jun 2003 20:11:14 GMT",
"version": "v1"
},
{
"created": "Wed, 1 Oct 2003 11:29:20 GMT",
"version": "v2"
}
] |
2010-04-05
|
[
[
"Aguilar-Saavedra",
"J. A.",
""
],
[
"Teixeira",
"A. M.",
""
]
] |
We discuss selectron pair production in e- e- scattering. These processes can only occur via t-channel neutralino exchange, provided that the neutralinos are Majorana fermions. We concentrate on the processes e- e- -> e^~_L e^~_L,e^~_R e^~_R -> e- X^~_1^0 e- X^~_2^0 -> e- X^~_1^0 e- X^~_1^0 f f, in which a complete determination of the final state momenta is possible without using the selectron masses as input. The experimental reconstruction of the selectron masses in this decay channel provides clear evidence of the Majorana character of the neutralinos, which is confirmed by the analysis of the electron energy spectrum.
|
1108.3765
|
Terrance Figy
|
Terrance Figy and Roman Zwicky
|
The other Higgses, at resonance, in the Lee-Wick extension of the
Standard Model
|
36 pages, 16 figures, 3 tables
| null |
10.1007/JHEP10(2011)145
|
CERN-PH-TH/2011-184, CP-3/2011-25
|
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Within the framework of the Lee Wick Standard Model (LWSM) we investigate
Higgs pair production $gg \to h_0 h_0$, $gg \to h_0 \tilde p_0$ and top pair
production $gg \to \bar tt$ at the Large Hadron Collider (LHC), where the
neutral particles from the Higgs sector ($h_0$, $\tilde h_0$ and $\tilde p_0$)
appear as possible resonant intermediate states. We investigate the signal $gg
\to h_0 h_0 \to \bar b b \gamma \gamma$ and we find that the LW Higgs,
depending on its mass-range, can be seen not long after the LHC upgrade in
2012. More precisely this happens when the new LW Higgs states are below the
top pair threshold. In $gg \to \bar tt$ the LW states, due to the wrong-sign
propagator and negative width, lead to a dip-peak structure instead of the
usual peak-dip structure which gives a characteristic signal especially for
low-lying LW Higgs states. We comment on the LWSM and the forward-backward
asymmetry in view of the measurement at the TeVatron. Furthermore, we present a
technique which reduces the hyperbolic diagonalization to standard
diagonalization methods. We clarify issues of spurious phases in the Yukawa
sector.
|
[
{
"created": "Thu, 18 Aug 2011 14:31:11 GMT",
"version": "v1"
}
] |
2015-05-30
|
[
[
"Figy",
"Terrance",
""
],
[
"Zwicky",
"Roman",
""
]
] |
Within the framework of the Lee Wick Standard Model (LWSM) we investigate Higgs pair production $gg \to h_0 h_0$, $gg \to h_0 \tilde p_0$ and top pair production $gg \to \bar tt$ at the Large Hadron Collider (LHC), where the neutral particles from the Higgs sector ($h_0$, $\tilde h_0$ and $\tilde p_0$) appear as possible resonant intermediate states. We investigate the signal $gg \to h_0 h_0 \to \bar b b \gamma \gamma$ and we find that the LW Higgs, depending on its mass-range, can be seen not long after the LHC upgrade in 2012. More precisely this happens when the new LW Higgs states are below the top pair threshold. In $gg \to \bar tt$ the LW states, due to the wrong-sign propagator and negative width, lead to a dip-peak structure instead of the usual peak-dip structure which gives a characteristic signal especially for low-lying LW Higgs states. We comment on the LWSM and the forward-backward asymmetry in view of the measurement at the TeVatron. Furthermore, we present a technique which reduces the hyperbolic diagonalization to standard diagonalization methods. We clarify issues of spurious phases in the Yukawa sector.
|
hep-ph/0109021
|
Marek Nowakowski
|
Marek Nowakowski (Universidad de los Andes, Colombia, and Universidad
de Guanajuato, Mexico)
|
Subtleties in CPT-Transformation for Majorana fermions
|
6 pages, to appear in Phys. Rev. D
|
Phys.Rev. D64 (2001) 116001
|
10.1103/PhysRevD.64.116001
| null |
hep-ph
| null |
We point out the relevance of the so-called Majorana creation phase in the
s-channel matrix elements in connection with the CPT-transformation of the
latter.
|
[
{
"created": "Mon, 3 Sep 2001 17:49:48 GMT",
"version": "v1"
}
] |
2009-11-07
|
[
[
"Nowakowski",
"Marek",
"",
"Universidad de los Andes, Colombia, and Universidad\n de Guanajuato, Mexico"
]
] |
We point out the relevance of the so-called Majorana creation phase in the s-channel matrix elements in connection with the CPT-transformation of the latter.
|
hep-ph/0008210
|
Frank Krueger
|
F. Kr\"uger, E. Lunghi
|
Looking for Novel CP-Violating Effects in B->K^*l^+l^-
|
22 pages, REVTeX, 8 figures; reference added
|
Phys.Rev.D63:014013,2001
|
10.1103/PhysRevD.63.014013
|
FISIST/09/2000/CFIF, SISSA/76/2000/EP
|
hep-ph
| null |
The CP-violating asymmetries in the exclusive decay B->K^*l^+l^- (l=e,mu,tau)
are predicted to be exceedingly small in the standard model (SM), thereby
offering an opportunity to assess various new-physics scenarios. We derive
quantitative predictions for various integrated observables in B->K^*mu^+mu^-
decay in the presence of physics beyond the SM with additional CP phases and an
extended operator basis. In particular, a model-independent analysis of CP
asymmetries that require the presence of unitarity phases, in addition to CP
violation, is performed. We find that in the low dimuon invariant mass region
2m_mu<M_{mu^+mu^-}<M_{J/psi}, the CP asymmetries are highly suppressed by small
dynamical phases, assuming that new physics is unlikely to significantly alter
the Wilson coefficients of the operators governing two-body hadronic B decays.
Taking into account current experimental data on the measured b->s gamma rate
and the upper limit on BR(B^0->K^{*0}mu^+mu^-), CP-violating effects of a few
per cent are estimated, even in the presence of new physics with CP phases of
O(1). By contrast, in the high dimuon invariant mass region
M_{psi'}<M_{mu^+mu^-}<(M_B-M_{K^*}) significant CP-violating effects are
possible. Given a branching ratio of 1.8 x 10^{-6}, the CP asymmetries can be
quite substantial (\sim 20% or more), and thus may serve as a means of
discovering physics transcending the SM.
|
[
{
"created": "Fri, 18 Aug 2000 22:59:13 GMT",
"version": "v1"
},
{
"created": "Tue, 22 Aug 2000 15:20:48 GMT",
"version": "v2"
}
] |
2011-03-23
|
[
[
"Krüger",
"F.",
""
],
[
"Lunghi",
"E.",
""
]
] |
The CP-violating asymmetries in the exclusive decay B->K^*l^+l^- (l=e,mu,tau) are predicted to be exceedingly small in the standard model (SM), thereby offering an opportunity to assess various new-physics scenarios. We derive quantitative predictions for various integrated observables in B->K^*mu^+mu^- decay in the presence of physics beyond the SM with additional CP phases and an extended operator basis. In particular, a model-independent analysis of CP asymmetries that require the presence of unitarity phases, in addition to CP violation, is performed. We find that in the low dimuon invariant mass region 2m_mu<M_{mu^+mu^-}<M_{J/psi}, the CP asymmetries are highly suppressed by small dynamical phases, assuming that new physics is unlikely to significantly alter the Wilson coefficients of the operators governing two-body hadronic B decays. Taking into account current experimental data on the measured b->s gamma rate and the upper limit on BR(B^0->K^{*0}mu^+mu^-), CP-violating effects of a few per cent are estimated, even in the presence of new physics with CP phases of O(1). By contrast, in the high dimuon invariant mass region M_{psi'}<M_{mu^+mu^-}<(M_B-M_{K^*}) significant CP-violating effects are possible. Given a branching ratio of 1.8 x 10^{-6}, the CP asymmetries can be quite substantial (\sim 20% or more), and thus may serve as a means of discovering physics transcending the SM.
|
1610.04729
|
Hiroshi Okada
|
Takaaki Nomura, Hiroshi Okada, Yuta Orikasa
|
A Radiative Neutrino Model with $SU(2)_L$ Triplet Fields
|
33 pages, 5 tables, 2 figures: Version accepted in Physical Review D.
arXiv admin note: text overlap with arXiv:1609.01504
|
Phys. Rev. D 94, 115018 (2016)
|
10.1103/PhysRevD.94.115018
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We propose a loop induced neutrino mass model, in which we introduce several
exotic fermions and bosons with $SU(2)_L$ multiplet, and discuss various
phenomenologies such as lepton flavor violations, muon anomalous magnetic
moment, nonstandard interacting neutrinoless double beta decay, relic density
of dark matter, and the possibility of the spin independent direct detection
searches, imposing the constraints of oblique parameters. And we show a
benchmark point to satisfy all the constraints and discuss our predictions.
|
[
{
"created": "Sat, 15 Oct 2016 13:02:24 GMT",
"version": "v1"
},
{
"created": "Thu, 27 Oct 2016 19:46:17 GMT",
"version": "v2"
},
{
"created": "Tue, 29 Nov 2016 18:01:14 GMT",
"version": "v3"
}
] |
2016-12-21
|
[
[
"Nomura",
"Takaaki",
""
],
[
"Okada",
"Hiroshi",
""
],
[
"Orikasa",
"Yuta",
""
]
] |
We propose a loop induced neutrino mass model, in which we introduce several exotic fermions and bosons with $SU(2)_L$ multiplet, and discuss various phenomenologies such as lepton flavor violations, muon anomalous magnetic moment, nonstandard interacting neutrinoless double beta decay, relic density of dark matter, and the possibility of the spin independent direct detection searches, imposing the constraints of oblique parameters. And we show a benchmark point to satisfy all the constraints and discuss our predictions.
|
1310.7798
|
Charles A. Nelson
|
Charles A. Nelson, Margarita Kraynova, Calvin S. Mera, and Alanna M.
Shapiro
|
Parastatistical Factors for Cascade Emission of a Pair of Paraparticles
|
8 pages
| null | null |
SUNY BING 10/24/13
|
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The empirical absence to date of particles obeying parastatistics in high
energy collider experiments might be due to their large masses and lack of
gauge couplings. If there is a portal to such particles, they might be cascade
emitted as a pair of para-Majorana neutrinos or as a pair of scalar
paraparticles. In this paper, for an assumed portal Lagrangian, the associated
parastatistical factors are obtained for the case of order p=2 parastatistics
and the, in general differing factors, for the cases of emission of a
non-degenerate or a degenerate pair of particles which obey normal statistics.
|
[
{
"created": "Tue, 29 Oct 2013 13:22:39 GMT",
"version": "v1"
}
] |
2013-10-30
|
[
[
"Nelson",
"Charles A.",
""
],
[
"Kraynova",
"Margarita",
""
],
[
"Mera",
"Calvin S.",
""
],
[
"Shapiro",
"Alanna M.",
""
]
] |
The empirical absence to date of particles obeying parastatistics in high energy collider experiments might be due to their large masses and lack of gauge couplings. If there is a portal to such particles, they might be cascade emitted as a pair of para-Majorana neutrinos or as a pair of scalar paraparticles. In this paper, for an assumed portal Lagrangian, the associated parastatistical factors are obtained for the case of order p=2 parastatistics and the, in general differing factors, for the cases of emission of a non-degenerate or a degenerate pair of particles which obey normal statistics.
|
hep-ph/9804304
|
Christopher Carone
|
Carl E. Carlson and Christopher D. Carone (William and Mary)
|
Photoproduction of of l=1 Baryons: Quark Model versus Large N_c
|
17 pages LaTeX, four EPS figures
|
Phys.Rev. D58 (1998) 053005
|
10.1103/PhysRevD.58.053005
|
WM-98-106
|
hep-ph
| null |
We consider the electromagnetic decays of the orbitally-excited SU(6) 70-plet
baryons, to compare the predictions of the naive quark model with those of
large-N_c QCD. The helicity amplitudes measured in N^* photoproduction are
computed in a large-N_c effective field theory, based on a Hartree
approximation, and the amplitudes are fit to the current experimental data. Our
results indicate that the success of the naive quark model predictions cannot
be explained by large-N_c arguments alone. This is consistent with the
conclusions of an earlier study of the N^*\to N\pi decays, that utilized the
same approach.
|
[
{
"created": "Thu, 16 Apr 1998 15:08:44 GMT",
"version": "v1"
}
] |
2009-10-31
|
[
[
"Carlson",
"Carl E.",
"",
"William and Mary"
],
[
"Carone",
"Christopher D.",
"",
"William and Mary"
]
] |
We consider the electromagnetic decays of the orbitally-excited SU(6) 70-plet baryons, to compare the predictions of the naive quark model with those of large-N_c QCD. The helicity amplitudes measured in N^* photoproduction are computed in a large-N_c effective field theory, based on a Hartree approximation, and the amplitudes are fit to the current experimental data. Our results indicate that the success of the naive quark model predictions cannot be explained by large-N_c arguments alone. This is consistent with the conclusions of an earlier study of the N^*\to N\pi decays, that utilized the same approach.
|
1511.03420
|
Yueling Yang
|
Junfeng Sun, Yueling Yang, Jinshu Huang, Lili Chen, Qin Chang
|
Study of the ${\psi}(1S,2S)$ and ${\eta}_{c}(1S,2S)$ weak decays into
$DM$
|
20 pages, revtex
|
Advances in High Energy Physics, 2016, 5071671
|
10.1155/2016/5071671
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Inspired by the recent measurements on the $J/{\psi}(1S)$ ${\to}$
$D_{s}{\rho}$, $D_{u}K^{\ast}$ weak decays at BESIII and the potential
prospects of the charmonium at the high-luminosity heavy-flavor experiments, we
study ${\psi}(1S,2S)$ and ${\eta}_{c}(1S,2S)$ weak decays into final states
including one charmed meson plus one light meson, considering the QCD
corrections to hadronic matrix elements with the QCD factorization. It is found
that the Cabibbo favored ${\psi}(1S,2S)$ ${\to}$ $D_{s}^{-}{\rho}^{+}$,
$D_{s}^{-}{\pi}^{+}$, $\overline{D}_{u}^{0}\overline{K}^{{\ast}0}$ decays have
branching ratios ${\gtrsim}$ $10^{-10}$, which might be accessible at the
future experiments.
|
[
{
"created": "Wed, 11 Nov 2015 08:42:47 GMT",
"version": "v1"
},
{
"created": "Sat, 5 Mar 2016 04:23:58 GMT",
"version": "v2"
}
] |
2016-03-08
|
[
[
"Sun",
"Junfeng",
""
],
[
"Yang",
"Yueling",
""
],
[
"Huang",
"Jinshu",
""
],
[
"Chen",
"Lili",
""
],
[
"Chang",
"Qin",
""
]
] |
Inspired by the recent measurements on the $J/{\psi}(1S)$ ${\to}$ $D_{s}{\rho}$, $D_{u}K^{\ast}$ weak decays at BESIII and the potential prospects of the charmonium at the high-luminosity heavy-flavor experiments, we study ${\psi}(1S,2S)$ and ${\eta}_{c}(1S,2S)$ weak decays into final states including one charmed meson plus one light meson, considering the QCD corrections to hadronic matrix elements with the QCD factorization. It is found that the Cabibbo favored ${\psi}(1S,2S)$ ${\to}$ $D_{s}^{-}{\rho}^{+}$, $D_{s}^{-}{\pi}^{+}$, $\overline{D}_{u}^{0}\overline{K}^{{\ast}0}$ decays have branching ratios ${\gtrsim}$ $10^{-10}$, which might be accessible at the future experiments.
|
1708.00770
|
Scientific Information Service CERN
|
E. Laenen
|
QCD
|
58 pages, contribution to the Proceedings of the 2014 European School
of High-Energy Physics. Garderen, the Netherlands, 18 June - 1 July 2014
|
CERN Yellow Report CERN 2016-003, pp. 1-58
|
10.5170/CERN-2016-003.1
| null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
In these lecture notes I describe the theory of QCD and its application,
through perturbation theory, at particle colliders.
|
[
{
"created": "Wed, 2 Aug 2017 14:40:12 GMT",
"version": "v1"
}
] |
2017-08-03
|
[
[
"Laenen",
"E.",
""
]
] |
In these lecture notes I describe the theory of QCD and its application, through perturbation theory, at particle colliders.
|
1310.2476
|
Thomas Gajdosik
|
Thomas Gajdosik, Andrius Juodagalvis, Darius Jur\v{c}iukonis, Tomas
Sabonis
|
Progress in the parametrisation of the Neutrino sector
|
6 pages, 2 figures; revised version addressed the criticism of the
editors, matches now the published version
|
Acta Phys.Polon. B44 (2013) 2347-2352
|
10.5506/APhysPolB.44.2347
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Adding gauge singlets to the original Standard Model allows an explanation
for the observed smallness of the neutrino masses using the seesaw mechanism.
Following our plans presented in the last conference of this series we present
the results for the non-standard setting, when the number of the singlets is
smaller than the number of the SM generations.
|
[
{
"created": "Wed, 9 Oct 2013 13:27:37 GMT",
"version": "v1"
},
{
"created": "Mon, 6 Jan 2014 16:44:19 GMT",
"version": "v2"
}
] |
2015-06-17
|
[
[
"Gajdosik",
"Thomas",
""
],
[
"Juodagalvis",
"Andrius",
""
],
[
"Jurčiukonis",
"Darius",
""
],
[
"Sabonis",
"Tomas",
""
]
] |
Adding gauge singlets to the original Standard Model allows an explanation for the observed smallness of the neutrino masses using the seesaw mechanism. Following our plans presented in the last conference of this series we present the results for the non-standard setting, when the number of the singlets is smaller than the number of the SM generations.
|
hep-ph/9906461
|
Juan Antonio Aguilar Saavedra
|
F. del Aguila, J. A. Aguilar-Saavedra
|
Top mixing
|
LaTeX 2e, 5 pages, uses JHEP.cls. Talk given by F. A. at the Corfu
Summer Institute on Elementary Particle Physics, 1998
| null | null |
UG-FT-99/99
|
hep-ph
| null |
We discuss the existing limits on top flavour-changing neutral couplings in
models with new vector-like quarks. Large hadron and e+ e- colliders can
improve these bounds by more than one order of magnitude.
|
[
{
"created": "Wed, 23 Jun 1999 17:39:40 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"del Aguila",
"F.",
""
],
[
"Aguilar-Saavedra",
"J. A.",
""
]
] |
We discuss the existing limits on top flavour-changing neutral couplings in models with new vector-like quarks. Large hadron and e+ e- colliders can improve these bounds by more than one order of magnitude.
|
hep-ph/0012335
|
Mayumi Aoki
|
Mayumi Aoki (KEK)
|
Decay rate asymmetry for $B \to X_s \gamma$ in SUSY model
|
4 pages, Talk presented at the UK Phenomenology Workshop on Heavy
Flavour and CP Violation, 17 - 22, September 2000, St John's College, Durham
|
J.Phys.G27:1179-1182,2001
|
10.1088/0954-3899/27/6/313
| null |
hep-ph
| null |
We discuss a rate asymmetry for the radiative $B$-meson decay $B \to X_s
\gamma$ within the framework of the supersymmetric standard model based on N=1
supergravity. This model contains new sources of CP violation. In spite of
severe experimental constraints on the electric dipole moment of the neutron, a
new CP-violating phase may not be suppressed, leading to a sizable enhancement
of the decay rate asymmetry. The magnitude of the asymmetry is predicted to be
larger than that by the standard model in wide parameter regions where the
branching ratio is consistent with its experimental bounds. A possible maximal
magnitude is about 0.1, which will be well accessible at B factories.
|
[
{
"created": "Mon, 25 Dec 2000 17:24:41 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Aoki",
"Mayumi",
"",
"KEK"
]
] |
We discuss a rate asymmetry for the radiative $B$-meson decay $B \to X_s \gamma$ within the framework of the supersymmetric standard model based on N=1 supergravity. This model contains new sources of CP violation. In spite of severe experimental constraints on the electric dipole moment of the neutron, a new CP-violating phase may not be suppressed, leading to a sizable enhancement of the decay rate asymmetry. The magnitude of the asymmetry is predicted to be larger than that by the standard model in wide parameter regions where the branching ratio is consistent with its experimental bounds. A possible maximal magnitude is about 0.1, which will be well accessible at B factories.
|
2101.08667
|
Kalliopi Petraki
|
Ruben Oncala and Kalliopi Petraki
|
Bound states of WIMP dark matter in Higgs-portal models. Part II.
Thermal decoupling
|
v1: 30 pages, 8 figures, 3 tables; v2: minor changes, published
version
|
JHEP 08 (2021) 069
|
10.1007/JHEP08(2021)069
|
Nikhef-2021-004
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The Higgs doublet can mediate a long-range interaction between multi-TeV
particles coupled to the Weak interactions of the Standard Model, while its
emission can lead to very rapid bound-state formation processes and
bound-to-bound transitions. Using the rates calculated in a companion paper,
here we compute the thermal decoupling of multi-TeV WIMP dark matter coupled to
the Higgs, and show that the formation of metastable dark matter bound states
via Higgs-doublet emission and their decay decrease the relic density very
significantly. This in turn implies that WIMP dark matter may be much heavier
than previously anticipated, or conversely that for a given mass, the dark
matter couplings to the Higgs may be much lower than previously predicted,
thereby altering the dark matter phenomenology. While we focus on a minimal
singlet-doublet model in the coannihilation regime, our calculations can be
extended to larger multiplets where the effects under consideration are
expected to be even more significant.
|
[
{
"created": "Thu, 21 Jan 2021 15:16:39 GMT",
"version": "v1"
},
{
"created": "Thu, 2 Sep 2021 12:00:48 GMT",
"version": "v2"
}
] |
2021-09-03
|
[
[
"Oncala",
"Ruben",
""
],
[
"Petraki",
"Kalliopi",
""
]
] |
The Higgs doublet can mediate a long-range interaction between multi-TeV particles coupled to the Weak interactions of the Standard Model, while its emission can lead to very rapid bound-state formation processes and bound-to-bound transitions. Using the rates calculated in a companion paper, here we compute the thermal decoupling of multi-TeV WIMP dark matter coupled to the Higgs, and show that the formation of metastable dark matter bound states via Higgs-doublet emission and their decay decrease the relic density very significantly. This in turn implies that WIMP dark matter may be much heavier than previously anticipated, or conversely that for a given mass, the dark matter couplings to the Higgs may be much lower than previously predicted, thereby altering the dark matter phenomenology. While we focus on a minimal singlet-doublet model in the coannihilation regime, our calculations can be extended to larger multiplets where the effects under consideration are expected to be even more significant.
|
1601.00486
|
Anatoly Kotikov Vassilievich
|
A.V. Kotikov
|
The property of maximal transcendentality: calculation of Feynman
integrals
|
15 pages, 3 figures, talk given at the V International Conference
"Models in Quantum Field Theory" (MQFT-2015), September 21-25, 2015, V.A.
Fock Physical Research Institute, Petergof, Russia. arXiv admin note:
substantial text overlap with arXiv:1212.3732
| null |
10.1134/S0040577917030084
| null |
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We review some results of calculations, having the property of maximal
transcendentality.
|
[
{
"created": "Mon, 4 Jan 2016 13:01:33 GMT",
"version": "v1"
},
{
"created": "Sat, 25 Jun 2016 08:44:23 GMT",
"version": "v2"
}
] |
2017-04-26
|
[
[
"Kotikov",
"A. V.",
""
]
] |
We review some results of calculations, having the property of maximal transcendentality.
|
1811.01748
|
Sergey Afonin
|
S. S. Afonin and T. D. Solomko
|
The linear radial spectrum of scalar mesons within the QCD sum rules in
the planar limit
|
8 pages, 2 figures, presented at QUARKS-2018. arXiv admin note:
substantial text overlap with arXiv:1805.06726
|
Published in EPJ Web of Conferences 191, 04004 (2018)
|
10.1051/epjconf/201819104004
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We discuss the radial spectrum of light scalar mesons in the framework of
spectral sum rules in the large-Nc (planar) limit of QCD. Two methods based on
the use of linear radial Regge trajectories are presented. A special emphasis
is placed on the appearance of scalar isoscalar state near 0.5 GeV. Within the
considered sum rules, the existence of this meson (which could be a large-Nc
counterpart to the sigma-meson) is closely related with existence of resonances
in the vector channels and on the radial scalar trajectory.
|
[
{
"created": "Fri, 2 Nov 2018 15:34:28 GMT",
"version": "v1"
}
] |
2018-11-06
|
[
[
"Afonin",
"S. S.",
""
],
[
"Solomko",
"T. D.",
""
]
] |
We discuss the radial spectrum of light scalar mesons in the framework of spectral sum rules in the large-Nc (planar) limit of QCD. Two methods based on the use of linear radial Regge trajectories are presented. A special emphasis is placed on the appearance of scalar isoscalar state near 0.5 GeV. Within the considered sum rules, the existence of this meson (which could be a large-Nc counterpart to the sigma-meson) is closely related with existence of resonances in the vector channels and on the radial scalar trajectory.
|
hep-ph/9803254
|
E. W. N. Glover
|
J. M. Campbell, E. W. N. Glover and C. J. Maxwell (Durham University)
|
Determination of Lambda_QCD from the measured energy dependence of
<1-Thrust>
|
12 pages, LaTeX, 3 figures, one figure added, discussion of heavy jet
mass added, some small textual changes
|
Phys.Rev.Lett.81:1568-1571,1998
|
10.1103/PhysRevLett.81.1568
|
DTP/98/08
|
hep-ph
| null |
We directly fit the experimentally measured energy dependence of the average
value of 1-Thrust, <1-T>, over the e^+e^- centre-of-mass energy range Q=14 -
172 GeV to the QCD expectation obtained by integrating up the evolution
equation for d<1-T>/dlog Q in terms of <1-T>. We fit for Lambda_QCD,
uncalculated O(alpha_S^3) and higher perturbative corrections parameterized by
the scheme invariant rho_2, and the parameter lambda which characterizes the
magnitude of the leading 1/Q power corrections anticipated for <1-T>. A
3-parameter fit yields Lambda_QCD=245^{+20}_{-17} MeV, rho_2=-16\pm 11 and
lambda=0.27^{+0.12}_{-0.10} GeV, equivalent to alpha_S(M_Z)=0.1194 \pm 0.0014.
In this approach, there is no error associated with the choice of the
renormalization scale mu.
|
[
{
"created": "Thu, 5 Mar 1998 15:01:16 GMT",
"version": "v1"
},
{
"created": "Wed, 27 May 1998 14:34:05 GMT",
"version": "v2"
}
] |
2008-11-26
|
[
[
"Campbell",
"J. M.",
"",
"Durham University"
],
[
"Glover",
"E. W. N.",
"",
"Durham University"
],
[
"Maxwell",
"C. J.",
"",
"Durham University"
]
] |
We directly fit the experimentally measured energy dependence of the average value of 1-Thrust, <1-T>, over the e^+e^- centre-of-mass energy range Q=14 - 172 GeV to the QCD expectation obtained by integrating up the evolution equation for d<1-T>/dlog Q in terms of <1-T>. We fit for Lambda_QCD, uncalculated O(alpha_S^3) and higher perturbative corrections parameterized by the scheme invariant rho_2, and the parameter lambda which characterizes the magnitude of the leading 1/Q power corrections anticipated for <1-T>. A 3-parameter fit yields Lambda_QCD=245^{+20}_{-17} MeV, rho_2=-16\pm 11 and lambda=0.27^{+0.12}_{-0.10} GeV, equivalent to alpha_S(M_Z)=0.1194 \pm 0.0014. In this approach, there is no error associated with the choice of the renormalization scale mu.
|
1806.07951
|
Estela A. Garces
|
L. J. Flores, E. A. Garc\'es and O. G. Miranda
|
Exploring NSI degeneracies in long-baseline experiments
|
13 pages, 4 multiple figures and one table. Title changed. Version
accepted for publication in PRD
|
Phys. Rev. D 98, 035030 (2018)
|
10.1103/PhysRevD.98.035030
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
One of the main purposes of long-baseline neutrino experiments is to
unambiguously measure the CP violating phase in the neutrino sector within the
three neutrino oscillation picture. In the presence of physics beyond the
Standard Model, the determination of the CP phase will be more difficult, due
to the already known degeneracy problem. Working in the framework of
non-standard interactions (NSI), we compute the appearance probabilities in an
exact analytical formulation and analyze the region of parameters where the
confusion problem is present. We also discuss some cases where the
falsification of the NSI parameters can be done in long-baseline experiments.
|
[
{
"created": "Wed, 20 Jun 2018 20:00:35 GMT",
"version": "v1"
},
{
"created": "Thu, 2 Aug 2018 18:21:08 GMT",
"version": "v2"
}
] |
2018-08-29
|
[
[
"Flores",
"L. J.",
""
],
[
"Garcés",
"E. A.",
""
],
[
"Miranda",
"O. G.",
""
]
] |
One of the main purposes of long-baseline neutrino experiments is to unambiguously measure the CP violating phase in the neutrino sector within the three neutrino oscillation picture. In the presence of physics beyond the Standard Model, the determination of the CP phase will be more difficult, due to the already known degeneracy problem. Working in the framework of non-standard interactions (NSI), we compute the appearance probabilities in an exact analytical formulation and analyze the region of parameters where the confusion problem is present. We also discuss some cases where the falsification of the NSI parameters can be done in long-baseline experiments.
|
hep-ph/0111254
|
Carlo Giunti
|
M.V. Garzelli, C. Giunti
|
Model Independent Information On Solar Neutrino Oscillations
|
40 pages, 20 figures. Added references and improved figures
|
Phys.Rev. D65 (2002) 093005
|
10.1103/PhysRevD.65.093005
|
KIAS-P01051
|
hep-ph astro-ph hep-ex physics.data-an
| null |
We present the results of a Bayesian analysis of solar neutrino data in terms
of nu_e->nu_{mu,tau} oscillations, independent from the Standard Solar Model
predictions for the solar neutrino fluxes. We show that such a model
independent analysis allows to constraint the values of the neutrino mixing
parameters in limited regions around the usual SMA, LMA, LOW and VO regions.
Furthermore, there is a strong indication in favor of large neutrino mixing and
large values of Delta m^2 (LMA region). We calculate also the allowed ranges of
the neutrino fluxes and we show that they are in good agreement with the
Standard Solar Model prediction. In particular, the ratio of the 8B flux with
its Standard Solar Model prediction is constrained in the interval [0.45,1.42]
with 99.73% probability. Finally, we show that the hypothesis of no neutrino
oscillations is strongly disfavored in a model independent way with respect to
the hypothesis of neutrino oscillations.
|
[
{
"created": "Wed, 21 Nov 2001 08:01:28 GMT",
"version": "v1"
},
{
"created": "Thu, 22 Nov 2001 02:11:50 GMT",
"version": "v2"
},
{
"created": "Thu, 13 Dec 2001 10:08:11 GMT",
"version": "v3"
}
] |
2009-11-07
|
[
[
"Garzelli",
"M. V.",
""
],
[
"Giunti",
"C.",
""
]
] |
We present the results of a Bayesian analysis of solar neutrino data in terms of nu_e->nu_{mu,tau} oscillations, independent from the Standard Solar Model predictions for the solar neutrino fluxes. We show that such a model independent analysis allows to constraint the values of the neutrino mixing parameters in limited regions around the usual SMA, LMA, LOW and VO regions. Furthermore, there is a strong indication in favor of large neutrino mixing and large values of Delta m^2 (LMA region). We calculate also the allowed ranges of the neutrino fluxes and we show that they are in good agreement with the Standard Solar Model prediction. In particular, the ratio of the 8B flux with its Standard Solar Model prediction is constrained in the interval [0.45,1.42] with 99.73% probability. Finally, we show that the hypothesis of no neutrino oscillations is strongly disfavored in a model independent way with respect to the hypothesis of neutrino oscillations.
|
0902.4028
|
Vasile Topor Pop N
|
V. Topor Pop, J. Barrette (McGill Univ., Canada), M. Gyulassy
(Columbia Univ. NY, USA)
|
Soft Open Charm Production in Heavy-Ion Collisions
|
5 pages, 3 figures, submitted to Phys. Rev. Lett
|
Phys.Rev.Lett.102:232302,2009
|
10.1103/PhysRevLett.102.232302
| null |
hep-ph astro-ph.HE hep-ex nucl-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Effects of strong longitudinal color electric fields (SCF) on the open charm
production in nucleus-nucleus (A + A) collisions at 200A GeV are investigated
within the framework of the HIJING-BBbar v2.0 model. A three fold increase of
the effective string tension due to in medium effects in A + A collisions,
results in a sizeable (60-70 percents) enhancement of the total charm
production cross sections. The nuclear modification factors show a suppression
at moderate transverse momentum consistent with RHIC data. At Large Hadron
Collider energies the model predicts an increase of total charm production
cross sections by approximately an order of magnitude.
|
[
{
"created": "Tue, 24 Feb 2009 17:31:29 GMT",
"version": "v1"
}
] |
2009-10-09
|
[
[
"Pop",
"V. Topor",
"",
"McGill Univ., Canada"
],
[
"Barrette",
"J.",
"",
"McGill Univ., Canada"
],
[
"Gyulassy",
"M.",
"",
"Columbia Univ. NY, USA"
]
] |
Effects of strong longitudinal color electric fields (SCF) on the open charm production in nucleus-nucleus (A + A) collisions at 200A GeV are investigated within the framework of the HIJING-BBbar v2.0 model. A three fold increase of the effective string tension due to in medium effects in A + A collisions, results in a sizeable (60-70 percents) enhancement of the total charm production cross sections. The nuclear modification factors show a suppression at moderate transverse momentum consistent with RHIC data. At Large Hadron Collider energies the model predicts an increase of total charm production cross sections by approximately an order of magnitude.
|
1506.02043
|
Jordi Salvado
|
Carlos A. Arg\"uelles, Teppei Katori, Jordi Salvado
|
New Physics in Astrophysical Neutrino Flavor
|
5 pages, 4 figures, accepted for publication by Phys. Rev. Lett
|
Phys. Rev. Lett. 115, 161303 (2015)
|
10.1103/PhysRevLett.115.161303
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Astrophysical neutrinos are powerful tools to investigate the fundamental
properties of particle physics through their flavor content. In this paper, we
perform the first general new physics study on ultra high energy neutrino
flavor content by introducing effective operators. We find that at the current
limits on these operators, new physics terms cause maximal effects on the
flavor content, however, the flavor content at Earth is confined to a region
related to the assumed initial flavor content. Furthermore, we conclude that a
precise measure of the flavor content at Earth will provide orders of magnitude
improvement on new physics bounds. Finally, we discuss the current best fits of
flavor content of the IceCube data and their interplay with new physics
scenarios.
|
[
{
"created": "Fri, 5 Jun 2015 20:00:57 GMT",
"version": "v1"
},
{
"created": "Tue, 6 Oct 2015 17:38:29 GMT",
"version": "v2"
}
] |
2015-10-21
|
[
[
"Argüelles",
"Carlos A.",
""
],
[
"Katori",
"Teppei",
""
],
[
"Salvado",
"Jordi",
""
]
] |
Astrophysical neutrinos are powerful tools to investigate the fundamental properties of particle physics through their flavor content. In this paper, we perform the first general new physics study on ultra high energy neutrino flavor content by introducing effective operators. We find that at the current limits on these operators, new physics terms cause maximal effects on the flavor content, however, the flavor content at Earth is confined to a region related to the assumed initial flavor content. Furthermore, we conclude that a precise measure of the flavor content at Earth will provide orders of magnitude improvement on new physics bounds. Finally, we discuss the current best fits of flavor content of the IceCube data and their interplay with new physics scenarios.
|
hep-ph/9905314
|
Kenichiro Aoki
|
Kenichiro Aoki and Kenji Ito
|
Physics of the gauged four fermi model in $(1+1)$ dimensions
|
16pp, figs
|
Phys.Rev. D60 (1999) 096004
|
10.1103/PhysRevD.60.096004
| null |
hep-ph
| null |
We analyze a two dimensional model of gauged fermions with quartic couplings
in the large-N limit. This combines the 't Hooft model and the Gross-Neveu
model where the coupling constants of both theories are arbitrary. Analytic
equations describing the meson states of the theory are derived and are solved
systematically using various methods. The physics of the model is investigated.
|
[
{
"created": "Wed, 12 May 1999 04:19:47 GMT",
"version": "v1"
}
] |
2009-10-31
|
[
[
"Aoki",
"Kenichiro",
""
],
[
"Ito",
"Kenji",
""
]
] |
We analyze a two dimensional model of gauged fermions with quartic couplings in the large-N limit. This combines the 't Hooft model and the Gross-Neveu model where the coupling constants of both theories are arbitrary. Analytic equations describing the meson states of the theory are derived and are solved systematically using various methods. The physics of the model is investigated.
|
hep-ph/9407367
| null |
Thomas G. Rizzo
|
Extending the Kinematic Range for $W_R$ Searches in $e^-e^-$ Collisions
at the NLC
|
LaTex,Worldsci,5pp, 6 figs(available on request), SLAC-PUB-6591
| null | null | null |
hep-ph
| null |
While the much discussed lepton-number violating process $e^-e^-\rightarrow
W_R^-W_R^-$ provides an excellent probe of both the Majorana nature of the
right-handed neutrino and the symmetry breaking sector of the Left-Right
Symmetric Model, it is likely that $W_R$'s are too massive to be pair produced
at the NLC with $\sqrt {s}$ in the 1-1.5 TeV range. We are thus lead to
consider the single $W_R$ production process $e^-e^-\rightarrow W_R^-(W_R^-)^*
\rightarrow W_R^-+jj$ in order to expand the collider's kinematic reach. After
pointing out that $W_R$'s with masses of order 1 TeV may be missed by future
hadron collider searches, we demonstrate that this three-body process possesses
a significant cross section, of order several fb, at the NLC with $\sqrt {s}$
in the range above. The angular distribution of the produced $W_R$'s is shown
to be essentially flat and the potential backgrounds from standard model
processes are shown to be small.
|
[
{
"created": "Mon, 25 Jul 1994 18:58:07 GMT",
"version": "v1"
}
] |
2009-09-25
|
[
[
"Rizzo",
"Thomas G.",
""
]
] |
While the much discussed lepton-number violating process $e^-e^-\rightarrow W_R^-W_R^-$ provides an excellent probe of both the Majorana nature of the right-handed neutrino and the symmetry breaking sector of the Left-Right Symmetric Model, it is likely that $W_R$'s are too massive to be pair produced at the NLC with $\sqrt {s}$ in the 1-1.5 TeV range. We are thus lead to consider the single $W_R$ production process $e^-e^-\rightarrow W_R^-(W_R^-)^* \rightarrow W_R^-+jj$ in order to expand the collider's kinematic reach. After pointing out that $W_R$'s with masses of order 1 TeV may be missed by future hadron collider searches, we demonstrate that this three-body process possesses a significant cross section, of order several fb, at the NLC with $\sqrt {s}$ in the range above. The angular distribution of the produced $W_R$'s is shown to be essentially flat and the potential backgrounds from standard model processes are shown to be small.
|
1605.01123
|
Claudio O. Dib
|
Claudio O. Dib, C. S. Kim, Kechen Wang, and Jue Zhang
|
Distinguishing Dirac/Majorana Sterile Neutrinos at the LHC
|
18 pages, 7 figures
|
Phys. Rev. D 94, 013005 (2016)
|
10.1103/PhysRevD.94.013005
|
DESY 16-077
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study the purely leptonic decays of $W^\pm \to e^\pm e^\pm \mu^\mp \nu$
and $\mu^\pm \mu^\pm e^\mp \nu$ produced at the LHC, induced by sterile
neutrinos with mass $m_N$ below $M_W$ in the intermediate state. Since the
final state neutrino escapes detection, one cannot tell whether this process
violates lepton number, what would indicate a Majorana character for the
intermediate sterile neutrino. Our study shows that when the sterile neutrino
mixings with electrons and muons are different enough, one can still
discriminate between the Dirac and Majorana character of this intermediate
neutrino by simply counting and comparing the above decay rates. After
performing collider simulations and statistical analysis, we find that at the
$14~\text{TeV}$ LHC with an integrated luminosity of $3000~\text{fb}^{-1}$, for
two benchmark scenarios $m_N$ = 20 GeV and 50 GeV, at least a $3\sigma$ level
of exclusion on the Dirac case can be achieved for disparities as mild as e.g.
$|U_{Ne}|^2 < 0.7~ |U_{N\mu}|^2$ or $|U_{N\mu}|^2 < 0.7~ |U_{N e}|^2$, provided
that $|U_{Ne}|^2$, $|U_{N\mu}|^2$ are both above $\sim 2\times 10^{-6}$.
|
[
{
"created": "Wed, 4 May 2016 01:21:32 GMT",
"version": "v1"
},
{
"created": "Fri, 24 Jun 2016 20:12:28 GMT",
"version": "v2"
}
] |
2016-07-13
|
[
[
"Dib",
"Claudio O.",
""
],
[
"Kim",
"C. S.",
""
],
[
"Wang",
"Kechen",
""
],
[
"Zhang",
"Jue",
""
]
] |
We study the purely leptonic decays of $W^\pm \to e^\pm e^\pm \mu^\mp \nu$ and $\mu^\pm \mu^\pm e^\mp \nu$ produced at the LHC, induced by sterile neutrinos with mass $m_N$ below $M_W$ in the intermediate state. Since the final state neutrino escapes detection, one cannot tell whether this process violates lepton number, what would indicate a Majorana character for the intermediate sterile neutrino. Our study shows that when the sterile neutrino mixings with electrons and muons are different enough, one can still discriminate between the Dirac and Majorana character of this intermediate neutrino by simply counting and comparing the above decay rates. After performing collider simulations and statistical analysis, we find that at the $14~\text{TeV}$ LHC with an integrated luminosity of $3000~\text{fb}^{-1}$, for two benchmark scenarios $m_N$ = 20 GeV and 50 GeV, at least a $3\sigma$ level of exclusion on the Dirac case can be achieved for disparities as mild as e.g. $|U_{Ne}|^2 < 0.7~ |U_{N\mu}|^2$ or $|U_{N\mu}|^2 < 0.7~ |U_{N e}|^2$, provided that $|U_{Ne}|^2$, $|U_{N\mu}|^2$ are both above $\sim 2\times 10^{-6}$.
|
hep-ph/0301087
|
David Blaschke
|
D. Blaschke, H. Grigorian, D.N. Aguilera, S. Yasui, H. Toki
|
Effects of quark matter and color superconductivity in compact stars
|
14 pages, 12 figures, Talk given at 2nd International Workshop on
Hadron Physics: Effective Theories of Low-Energy QCD, Coimbra, Portugal,
25-29 Sep 2002
|
AIP Conf.Proc. 660 (2003) 209-222
|
10.1063/1.1570573
|
MPG-VT-UR 234/03
|
hep-ph
| null |
The equation of state for quark matter is derived for a nonlocal, chiral
quark model within the mean field approximation. We investigate the effects of
a variation of the form factors of the interaction on the phase diagram of
quark matter under the condition of beta-equilibrium and charge neutrality.
Special emphasis is on the occurrence of a diquark condensate which signals a
phase transition to color superconductivity and its effects on the equation of
state. We calculate the quark star configurations by solving the Tolman-
Oppenheimer- Volkoff equations and obtain for the transition from a hot, normal
quark matter core of a protoneutron star to a cool diquark condensed one a
release of binding energy of the order of Delta M c^2 ~ 10^{53} erg. We study
the consequences of antineutrino trapping in hot quark matter for quark star
configurations with possible diquark condensation and discuss the claim that
this energy could serve as an engine for explosive phenomena. A "phase diagram"
for rotating compact stars (angular velocity-baryon mass plane) is suggested as
a heuristic tool for obtaining constraints on the equation of state of QCD at
high densities. It has a critical line dividing hadronic from quark core stars
which is correlated with a local maximum of the moment of inertia and can thus
be subject to experimental verification by observation of the rotational
behavior of accreting compact stars.
|
[
{
"created": "Mon, 13 Jan 2003 22:05:37 GMT",
"version": "v1"
}
] |
2009-11-10
|
[
[
"Blaschke",
"D.",
""
],
[
"Grigorian",
"H.",
""
],
[
"Aguilera",
"D. N.",
""
],
[
"Yasui",
"S.",
""
],
[
"Toki",
"H.",
""
]
] |
The equation of state for quark matter is derived for a nonlocal, chiral quark model within the mean field approximation. We investigate the effects of a variation of the form factors of the interaction on the phase diagram of quark matter under the condition of beta-equilibrium and charge neutrality. Special emphasis is on the occurrence of a diquark condensate which signals a phase transition to color superconductivity and its effects on the equation of state. We calculate the quark star configurations by solving the Tolman- Oppenheimer- Volkoff equations and obtain for the transition from a hot, normal quark matter core of a protoneutron star to a cool diquark condensed one a release of binding energy of the order of Delta M c^2 ~ 10^{53} erg. We study the consequences of antineutrino trapping in hot quark matter for quark star configurations with possible diquark condensation and discuss the claim that this energy could serve as an engine for explosive phenomena. A "phase diagram" for rotating compact stars (angular velocity-baryon mass plane) is suggested as a heuristic tool for obtaining constraints on the equation of state of QCD at high densities. It has a critical line dividing hadronic from quark core stars which is correlated with a local maximum of the moment of inertia and can thus be subject to experimental verification by observation of the rotational behavior of accreting compact stars.
|
0908.0194
|
Swatantra Tiwari
|
C. P. Singh, P. K. Srivastava, S. K. Tiwari
|
QCD Phase Boundary and Critical Point in a Bag Model Calculation
|
8 pages,1 figure
|
Phys.Rev.D80:114508,2009; Erratum-ibid.D83:039904,2011
|
10.1103/PhysRevD.80.114508 10.1103/PhysRevD.83.039904
| null |
hep-ph
|
http://creativecommons.org/licenses/publicdomain/
|
Location of critical point and mapping the QCD phase boundary still exists as
one of the most interesting and studied problems of heavy-ion physics. A new
equation of state (EOS) for a gas of extended baryons and pointlike mesons is
presented here which accounts for the repulsive hard-core interactions arising
due to the geometrical size of the baryons. A first order deconfining phase
transition is obtained using Gibbs' equilibrium criteria and a bag model EOS
for the weakly interacting quark matter. It is interesting to find that the
phase transition line ends at a critical point beyond which a cross-over region
exists between hot-dense meson gas and quark-antiquark gluon matter. Our curve
resembles in shape closely with the predictions of the available lattice gauge
calculations and also reproduces the conjectured phase boundary.
|
[
{
"created": "Mon, 3 Aug 2009 11:49:45 GMT",
"version": "v1"
},
{
"created": "Sat, 31 Oct 2009 04:47:45 GMT",
"version": "v2"
}
] |
2011-03-23
|
[
[
"Singh",
"C. P.",
""
],
[
"Srivastava",
"P. K.",
""
],
[
"Tiwari",
"S. K.",
""
]
] |
Location of critical point and mapping the QCD phase boundary still exists as one of the most interesting and studied problems of heavy-ion physics. A new equation of state (EOS) for a gas of extended baryons and pointlike mesons is presented here which accounts for the repulsive hard-core interactions arising due to the geometrical size of the baryons. A first order deconfining phase transition is obtained using Gibbs' equilibrium criteria and a bag model EOS for the weakly interacting quark matter. It is interesting to find that the phase transition line ends at a critical point beyond which a cross-over region exists between hot-dense meson gas and quark-antiquark gluon matter. Our curve resembles in shape closely with the predictions of the available lattice gauge calculations and also reproduces the conjectured phase boundary.
|
1911.05963
|
Nobuhito Maru
|
Yuki Adachi and Nobuhito Maru
|
Strong First Order Electroweak Phase Transition in Gauge-Higgs
Unification at Finite Temperature
|
14 pages, 7 figures
|
Phys. Rev. D 101, 036013 (2020)
|
10.1103/PhysRevD.101.036013
|
OCU-PHYS-514, NITEP 40
|
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We analyze the electroweak phase transition at finite temperature in a model
of gauge-Higgs unification where the fermion mass hierarchy including top quark
mass, a viable electroweak symmetry breaking and an observed Higgs mass are
successfully reproduced. To study the phase transition, we derive the general
formula of the 1-loop effective potential at finite temperature by using the
$\zeta$ function regularization method. It is remarkable that the functions
determining the Kaluza-Klein mass spectrum have only to be necessary in
calculations. This potential can be applicable to any higher dimensional theory
in flat space where one extra spatial dimension is compactified. Applying to
our model of gauge-Higgs unification, the strong first phase transition
compatible with 125 GeV Higgs mass is found to happen.
|
[
{
"created": "Thu, 14 Nov 2019 06:57:09 GMT",
"version": "v1"
}
] |
2020-02-26
|
[
[
"Adachi",
"Yuki",
""
],
[
"Maru",
"Nobuhito",
""
]
] |
We analyze the electroweak phase transition at finite temperature in a model of gauge-Higgs unification where the fermion mass hierarchy including top quark mass, a viable electroweak symmetry breaking and an observed Higgs mass are successfully reproduced. To study the phase transition, we derive the general formula of the 1-loop effective potential at finite temperature by using the $\zeta$ function regularization method. It is remarkable that the functions determining the Kaluza-Klein mass spectrum have only to be necessary in calculations. This potential can be applicable to any higher dimensional theory in flat space where one extra spatial dimension is compactified. Applying to our model of gauge-Higgs unification, the strong first phase transition compatible with 125 GeV Higgs mass is found to happen.
|
hep-ph/9707453
|
J.-Alexis Rodriguez L.
|
R. Martinez and J.-Alexis Rodriguez L. (Universidad Nacional de
Colombia)
|
Constraint of the magnetic moment of the top quark
|
6 pages, 3 figures, RevTeX
|
Phys.Rev.D60:077504,1999
|
10.1103/PhysRevD.60.077504
| null |
hep-ph
| null |
We derive a bound on the magnetic dipole moment of the top quark in the
context of the effective Lagrangian approach by using the values of the ratio
$R_b = \Gamma_b/\Gamma_h$, $R_l = \Gamma_h/\Gamma_l$ and $\Gamma_Z$. We found
that the oblique corrections are more sensible than the vertex ones for this
moment.
|
[
{
"created": "Thu, 24 Jul 1997 19:44:08 GMT",
"version": "v1"
},
{
"created": "Thu, 6 Nov 1997 21:00:44 GMT",
"version": "v2"
}
] |
2014-11-17
|
[
[
"Martinez",
"R.",
"",
"Universidad Nacional de\n Colombia"
],
[
"L.",
"J. -Alexis Rodriguez",
"",
"Universidad Nacional de\n Colombia"
]
] |
We derive a bound on the magnetic dipole moment of the top quark in the context of the effective Lagrangian approach by using the values of the ratio $R_b = \Gamma_b/\Gamma_h$, $R_l = \Gamma_h/\Gamma_l$ and $\Gamma_Z$. We found that the oblique corrections are more sensible than the vertex ones for this moment.
|
hep-ph/0612063
|
Xuelei Wang
|
Wenna Xu, Xuelei Wang, Zhenjun Xiao
|
The single t-quark productions via the flavor-changing processes in the
topcolor-assisted technicolor model at the hadron colliders
|
15 pages, 10 figures
|
Commun.Theor.Phys.49:193-198,2008
|
10.1088/0253-6102/49/1/40
| null |
hep-ph
| null |
In the framework of topcolor-assisted technicolor(TC2) model, there exist
tree-level flavor-changing (FC) couplings which can result in the loop-level FC
coupling $tcg$. Such $tcg$ coupling can contribute significant clues at the
forthcoming Large Hadron Collider (LHC) experiments. In this paper, based on
the TC2 model, we study some single t-quark production processes involving
$tcg$ coupling at the Tevatron and LHC: $pp(p\bar{p})\to t\bar{q}(q=u,d,s),tg$.
We calculate the cross sections of these processes. The results show that the
cross sections at the Tevatron are too small to observe the signal, but at the
LHC it can reach a few pb. With the high luminosity, the LHC has considerable
capability to find the single t-quark signal produced via some FC processes
involving coupling $tcg$. On the other hand, these processes can also provide
some valuable information of the coupling $tcg$ with detailed study of the
processes and furthermore provide the reliable evidence to test the TC2 model.
|
[
{
"created": "Wed, 6 Dec 2006 10:48:08 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Xu",
"Wenna",
""
],
[
"Wang",
"Xuelei",
""
],
[
"Xiao",
"Zhenjun",
""
]
] |
In the framework of topcolor-assisted technicolor(TC2) model, there exist tree-level flavor-changing (FC) couplings which can result in the loop-level FC coupling $tcg$. Such $tcg$ coupling can contribute significant clues at the forthcoming Large Hadron Collider (LHC) experiments. In this paper, based on the TC2 model, we study some single t-quark production processes involving $tcg$ coupling at the Tevatron and LHC: $pp(p\bar{p})\to t\bar{q}(q=u,d,s),tg$. We calculate the cross sections of these processes. The results show that the cross sections at the Tevatron are too small to observe the signal, but at the LHC it can reach a few pb. With the high luminosity, the LHC has considerable capability to find the single t-quark signal produced via some FC processes involving coupling $tcg$. On the other hand, these processes can also provide some valuable information of the coupling $tcg$ with detailed study of the processes and furthermore provide the reliable evidence to test the TC2 model.
|
1310.2839
|
Nikonov Victor A.
|
V.V. Anisovich, V.A. Nikonov, J. Nyiri
|
Asymptotic regime for hadron-hadron diffractive collisions at ultrahigh
energies
|
8 pages. arXiv admin note: text overlap with arXiv:1306.1735
| null |
10.1103/PhysRevD.88.094015
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Using the pre-LHC and LHC data for $\pi p$ and $pp$ diffractive collisions we
study the ultrahigh energy asymptotic regime in the framework of the black disk
picture. The black disk picture, being constrained by the s-channel unitarity
condition and the $t$-channel analyticity, gives rather definite predictions
for diffractive processes increasing with the energy. To deal with the data, we
consider the Dakhno-Nikonov eikonal model which predicts a growth of the
$\ln^2s$ type for total and elastic cross sections and $(\tau={\bf
q}_\perp^2\ln^2s)$-scaling for diffractive scattering and diffractive
dissociation of hadrons. According to the calculations, ultrahigh energy
asymptotic characteristics of diffractive and total cross sections are
universal, and this results in the asymptotic equality of cross sections for
all types of hadrons. We estimate the energy scale of the asymptotics in
different processes. The manifestation of the asymptotic regime in hadron
fragmentation reactions is discussed.
|
[
{
"created": "Thu, 10 Oct 2013 14:37:21 GMT",
"version": "v1"
},
{
"created": "Fri, 25 Oct 2013 13:08:23 GMT",
"version": "v2"
}
] |
2014-03-12
|
[
[
"Anisovich",
"V. V.",
""
],
[
"Nikonov",
"V. A.",
""
],
[
"Nyiri",
"J.",
""
]
] |
Using the pre-LHC and LHC data for $\pi p$ and $pp$ diffractive collisions we study the ultrahigh energy asymptotic regime in the framework of the black disk picture. The black disk picture, being constrained by the s-channel unitarity condition and the $t$-channel analyticity, gives rather definite predictions for diffractive processes increasing with the energy. To deal with the data, we consider the Dakhno-Nikonov eikonal model which predicts a growth of the $\ln^2s$ type for total and elastic cross sections and $(\tau={\bf q}_\perp^2\ln^2s)$-scaling for diffractive scattering and diffractive dissociation of hadrons. According to the calculations, ultrahigh energy asymptotic characteristics of diffractive and total cross sections are universal, and this results in the asymptotic equality of cross sections for all types of hadrons. We estimate the energy scale of the asymptotics in different processes. The manifestation of the asymptotic regime in hadron fragmentation reactions is discussed.
|
hep-ph/9806537
|
Gregory Korchemsy
|
G.P.Korchemsky
|
Shape functions and power corrections to the event shapes
|
13 pages, LaTeX style, 4 figures embedded with epsf.sty
| null | null |
LPTHE-Orsay-98-44
|
hep-ph
| null |
We show that the leading power corrections to the event shape distributions
can be resummed into nonperturbative shape functions that do not depend on the
center-of-mass energy and measure the energy flow in the final state. In the
case of the thrust variable, the distribution is given by the convolution of
the perturbative spectrum with the shape function. Choosing the simplest ansatz
for the shape function we find that our predictions for the thrust distribution
provide a good description of the data throughout a wide range of energies.
|
[
{
"created": "Tue, 30 Jun 1998 20:03:16 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Korchemsky",
"G. P.",
""
]
] |
We show that the leading power corrections to the event shape distributions can be resummed into nonperturbative shape functions that do not depend on the center-of-mass energy and measure the energy flow in the final state. In the case of the thrust variable, the distribution is given by the convolution of the perturbative spectrum with the shape function. Choosing the simplest ansatz for the shape function we find that our predictions for the thrust distribution provide a good description of the data throughout a wide range of energies.
|
hep-ph/9801314
|
Jens Aage Pedersen
|
I.N. Mishustin, J.A. Pedersen and O. Scavenius
|
Fluid Dynamical Description of the Chiral Transition
|
9 pages LaTeX, 4 postscript figures
|
Heavy Ion Phys.5:377-386,1997
| null |
NBI 98-02
|
hep-ph
| null |
We investigate the dynamics of the chiral transition in an expanding
quark-anti-quark plasma. The calculations are made within a linear sigma model
with explicit quark and antiquark degrees of freedom. We solve numerically the
classical equations of motion for chiral fields coupled to the fluid dynamical
equations for the plasma. Fast initial growth and strong oscillations of the
chiral field and strong amplification of long wavelength modes of the pion
field are observed in the course of the chiral transition.
|
[
{
"created": "Thu, 15 Jan 1998 14:56:39 GMT",
"version": "v1"
}
] |
2011-04-15
|
[
[
"Mishustin",
"I. N.",
""
],
[
"Pedersen",
"J. A.",
""
],
[
"Scavenius",
"O.",
""
]
] |
We investigate the dynamics of the chiral transition in an expanding quark-anti-quark plasma. The calculations are made within a linear sigma model with explicit quark and antiquark degrees of freedom. We solve numerically the classical equations of motion for chiral fields coupled to the fluid dynamical equations for the plasma. Fast initial growth and strong oscillations of the chiral field and strong amplification of long wavelength modes of the pion field are observed in the course of the chiral transition.
|
1804.04852
|
Jambul Gegelia
|
J. Gegelia, Ulf-G. Mei{\ss}ner
|
Once more on the Higgs decay into two photons
|
6 pages, 1 figure
|
Nucl. Phys. B 934 (2018) 1-6
|
10.1016/j.nuclphysb.2018.06.021
| null |
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We comment on the recently reiterated claim that the contribution of the
W-boson loop to the Higgs boson decay into two photons leads to different
expressions in the $R_\xi$ gauge and the unitary gauge. By applying a
gauge-symmetry preserving regularization with higher-order covariant
derivatives we reproduce once again the "classical" gauge-independent result.
|
[
{
"created": "Fri, 13 Apr 2018 09:24:26 GMT",
"version": "v1"
}
] |
2018-07-09
|
[
[
"Gegelia",
"J.",
""
],
[
"Meißner",
"Ulf-G.",
""
]
] |
We comment on the recently reiterated claim that the contribution of the W-boson loop to the Higgs boson decay into two photons leads to different expressions in the $R_\xi$ gauge and the unitary gauge. By applying a gauge-symmetry preserving regularization with higher-order covariant derivatives we reproduce once again the "classical" gauge-independent result.
|
1403.5846
|
Gui-Jun Ding
|
Gui-Jun Ding, Stephen F. King
|
Generalised CP and $\Delta (96)$ Family Symmetry
|
71 pages, 10 figures
|
Phys. Rev. D 89, 093020 (2014)
|
10.1103/PhysRevD.89.093020
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We perform a comprehensive study of the $\Delta (96)$ family symmetry
combined with the generalised CP symmetry $H_{\rm{CP}}$. We investigate the
lepton mixing parameters which can be obtained from the original symmetry
$\Delta (96)\rtimes H_{\rm{CP}}$ breaking to different remnant symmetries in
the neutrino and charged lepton sectors, namely $G_{\nu}$ and $G_l$ subgroups
in the neutrino and the charged lepton sector respectively, and the remnant CP
symmetries from the breaking of $H_{\rm{CP}}$ are $H^{\nu}_{\rm{CP}}$ and
$H^{l}_{\rm{CP}}$, respectively, where all cases correspond to a preserved
symmetry smaller than the full Klein symmetry, as in the semi-direct approach,
leading to predictions which depend on a single undetermined real parameter,
which may be fitted to the reactor angle for example. We discuss 26 possible
cases, including a global $\chi^2$ determination of the best fit parameters and
the correlations between mixing parameters, in each case.
|
[
{
"created": "Mon, 24 Mar 2014 04:12:29 GMT",
"version": "v1"
}
] |
2014-06-11
|
[
[
"Ding",
"Gui-Jun",
""
],
[
"King",
"Stephen F.",
""
]
] |
We perform a comprehensive study of the $\Delta (96)$ family symmetry combined with the generalised CP symmetry $H_{\rm{CP}}$. We investigate the lepton mixing parameters which can be obtained from the original symmetry $\Delta (96)\rtimes H_{\rm{CP}}$ breaking to different remnant symmetries in the neutrino and charged lepton sectors, namely $G_{\nu}$ and $G_l$ subgroups in the neutrino and the charged lepton sector respectively, and the remnant CP symmetries from the breaking of $H_{\rm{CP}}$ are $H^{\nu}_{\rm{CP}}$ and $H^{l}_{\rm{CP}}$, respectively, where all cases correspond to a preserved symmetry smaller than the full Klein symmetry, as in the semi-direct approach, leading to predictions which depend on a single undetermined real parameter, which may be fitted to the reactor angle for example. We discuss 26 possible cases, including a global $\chi^2$ determination of the best fit parameters and the correlations between mixing parameters, in each case.
|
hep-ph/9610360
|
Johan Bijnens
|
Johan Bijnens(Nordita) and Joaquim Prades(IFIC and Valencia)
|
Electromagnetic Corrections for Pions and Kaons : Masses and
Polarizabilities
|
LaTeX, 5 figures, uses epsf, 39 pages, partially rewritten, more
information about $\mu$ dependence included
|
Nucl.Phys. B490 (1997) 239-271
|
10.1016/S0550-3213(97)00107-7
|
FTUV/96-69,IFIC/96-78, NORDITA-96/70 N,P
|
hep-ph
| null |
The unknown constants in Chiral Perturbation Theory needed for an all orders
analysis of the polarizabilities and electromagnetic corrections to the masses
of the pseudo-Goldstone bosons are estimated at leading order in $1/N_c$. We
organize the calculation in an $1/N_c$-expansion and separate long- and
short-distance physics contributions by introducing an Euclidean cut-off. The
long-distance part is evaluated using the ENJL model and the short-distance
part using perturbative QCD and factorization. We obtain very good matching
between both.
We then include these estimates in a full Chiral Perturbation Theory
calculation to order $e^2$ $p^2$ for the masses and $p^6$ for the
polarizabilities. For the electromagnetic corrections to the masses, we confirm
a large violation of Dashen's theorem getting a more precise value for this
violation. We make comparison with earlier related work. Some phenomenological
consequences are discussed too.
|
[
{
"created": "Tue, 15 Oct 1996 09:11:40 GMT",
"version": "v1"
},
{
"created": "Mon, 27 Jan 1997 09:14:01 GMT",
"version": "v2"
}
] |
2009-10-28
|
[
[
"Bijnens",
"Johan",
"",
"Nordita"
],
[
"Prades",
"Joaquim",
"",
"IFIC and Valencia"
]
] |
The unknown constants in Chiral Perturbation Theory needed for an all orders analysis of the polarizabilities and electromagnetic corrections to the masses of the pseudo-Goldstone bosons are estimated at leading order in $1/N_c$. We organize the calculation in an $1/N_c$-expansion and separate long- and short-distance physics contributions by introducing an Euclidean cut-off. The long-distance part is evaluated using the ENJL model and the short-distance part using perturbative QCD and factorization. We obtain very good matching between both. We then include these estimates in a full Chiral Perturbation Theory calculation to order $e^2$ $p^2$ for the masses and $p^6$ for the polarizabilities. For the electromagnetic corrections to the masses, we confirm a large violation of Dashen's theorem getting a more precise value for this violation. We make comparison with earlier related work. Some phenomenological consequences are discussed too.
|
2106.08334
|
Jack Y. Araz
|
Jack Y. Araz and Michael Spannowsky
|
Quantum-inspired event reconstruction with Tensor Networks: Matrix
Product States
|
29 pages, 15 figures. Accepted version for publication in JHEP
|
JHEP 08 (2021) 112
|
10.1007/JHEP08(2021)112
|
IPPP/20/114
|
hep-ph cs.LG hep-ex physics.data-an
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Tensor Networks are non-trivial representations of high-dimensional tensors,
originally designed to describe quantum many-body systems. We show that Tensor
Networks are ideal vehicles to connect quantum mechanical concepts to machine
learning techniques, thereby facilitating an improved interpretability of
neural networks. This study presents the discrimination of top quark signal
over QCD background processes using a Matrix Product State classifier. We show
that entanglement entropy can be used to interpret what a network learns, which
can be used to reduce the complexity of the network and feature space without
loss of generality or performance. For the optimisation of the network, we
compare the Density Matrix Renormalization Group (DMRG) algorithm to stochastic
gradient descent (SGD) and propose a joined training algorithm to harness the
explainability of DMRG with the efficiency of SGD.
|
[
{
"created": "Tue, 15 Jun 2021 18:00:02 GMT",
"version": "v1"
},
{
"created": "Fri, 6 Aug 2021 08:47:07 GMT",
"version": "v2"
}
] |
2021-09-09
|
[
[
"Araz",
"Jack Y.",
""
],
[
"Spannowsky",
"Michael",
""
]
] |
Tensor Networks are non-trivial representations of high-dimensional tensors, originally designed to describe quantum many-body systems. We show that Tensor Networks are ideal vehicles to connect quantum mechanical concepts to machine learning techniques, thereby facilitating an improved interpretability of neural networks. This study presents the discrimination of top quark signal over QCD background processes using a Matrix Product State classifier. We show that entanglement entropy can be used to interpret what a network learns, which can be used to reduce the complexity of the network and feature space without loss of generality or performance. For the optimisation of the network, we compare the Density Matrix Renormalization Group (DMRG) algorithm to stochastic gradient descent (SGD) and propose a joined training algorithm to harness the explainability of DMRG with the efficiency of SGD.
|
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