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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
hep-ph/0106199 | Athanasios Dedes | Athanasios Dedes, Herbi Dreiner, and Peter Richardson | Attempts at Explaining the NuTeV Observation of Di-Muon Events | 17 pages, 9 figures, final version to appear in Phys. Rev. D | Phys.Rev.D65:015001,2001 | 10.1103/PhysRevD.65.015001 | Cavendish HEP-2001-05, DAMTP-2001-47 | hep-ph hep-ex | null | The NuTeV Collaboration has observed an excess in their di-muon channel,
possibly corresponding to a long-lived neutral particle with only weak
interactions and which decays to muon pairs. We show that this can {\it not} be
explained by pair production of neutralinos in the target followed by their
decay far downstream in the detector via a $LLE$ R-parity violating (RPV)
operator, as suggested in the literature. In the parameter region allowed by
LEP the event rate is far too small. We propose instead a new neutralino
production method via $B$-mesons, which can fully explain the observation. This
is analogous to neutrino production via $\pi$-mesons. This model can be
completely tested and thus also possibly excluded with NOMAD data. If it is
excluded, the NuTeV observation is most likely not due to physics beyond the
Standard Model. Our model can also be tested at the current and future
$B$-factories. This opens up a new way of testing a long-lived neutralino LSP
at fixed-target experiments and thus a possibility to close the gap between
collider and cosmological tests of R-parity violation. We also discuss a
possible explanation in terms of a neutral heavy lepton mixing with the
Standard Model neutrinos. The flavour structure of the observation can be
accounted for but the production rate is far too low.
| [
{
"created": "Mon, 18 Jun 2001 16:21:35 GMT",
"version": "v1"
},
{
"created": "Thu, 21 Jun 2001 13:41:43 GMT",
"version": "v2"
},
{
"created": "Thu, 6 Sep 2001 09:32:23 GMT",
"version": "v3"
}
] | 2014-11-17 | [
[
"Dedes",
"Athanasios",
""
],
[
"Dreiner",
"Herbi",
""
],
[
"Richardson",
"Peter",
""
]
] | The NuTeV Collaboration has observed an excess in their di-muon channel, possibly corresponding to a long-lived neutral particle with only weak interactions and which decays to muon pairs. We show that this can {\it not} be explained by pair production of neutralinos in the target followed by their decay far downstream in the detector via a $LLE$ R-parity violating (RPV) operator, as suggested in the literature. In the parameter region allowed by LEP the event rate is far too small. We propose instead a new neutralino production method via $B$-mesons, which can fully explain the observation. This is analogous to neutrino production via $\pi$-mesons. This model can be completely tested and thus also possibly excluded with NOMAD data. If it is excluded, the NuTeV observation is most likely not due to physics beyond the Standard Model. Our model can also be tested at the current and future $B$-factories. This opens up a new way of testing a long-lived neutralino LSP at fixed-target experiments and thus a possibility to close the gap between collider and cosmological tests of R-parity violation. We also discuss a possible explanation in terms of a neutral heavy lepton mixing with the Standard Model neutrinos. The flavour structure of the observation can be accounted for but the production rate is far too low. |
1705.01179 | I. V. Danilkin | Igor Danilkin and Marc Vanderhaeghen | Light-by-light forward scattering sum rules for charmonium states | 9 pages, 2 figures | Phys. Rev. D 96, 056003 (2017) | 10.1103/PhysRevD.96.056003 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We apply three forward light-by-light scattering sum rules to charmonium
states. We show that these sum rules imply a cancellation between charmonium
bound state contributions, which are mostly known from the $\gamma \gamma$
decay widths of these states, and continuum contributions above $D \bar D$
threshold, for which we provide a duality estimate. We also show that two of
these sum rules allow to predict the yet unmeasured $\gamma^\ast \gamma$
coupling of the $\chi_{c1}(1P)$ state, which can be tested at present
high-luminosity $e^+ e^-$ colliders.
| [
{
"created": "Tue, 2 May 2017 21:44:19 GMT",
"version": "v1"
},
{
"created": "Fri, 25 Aug 2017 13:56:42 GMT",
"version": "v2"
}
] | 2017-09-13 | [
[
"Danilkin",
"Igor",
""
],
[
"Vanderhaeghen",
"Marc",
""
]
] | We apply three forward light-by-light scattering sum rules to charmonium states. We show that these sum rules imply a cancellation between charmonium bound state contributions, which are mostly known from the $\gamma \gamma$ decay widths of these states, and continuum contributions above $D \bar D$ threshold, for which we provide a duality estimate. We also show that two of these sum rules allow to predict the yet unmeasured $\gamma^\ast \gamma$ coupling of the $\chi_{c1}(1P)$ state, which can be tested at present high-luminosity $e^+ e^-$ colliders. |
2104.03975 | Jaume Tarr\'us Castell\`a | Jaume Tarr\'us Castell\`a, Emilie Passemar | Exotic to standard bottomonium transitions | 22 pages, 6 figures, Journal version | Phys. Rev. D 104, 034019 (2021) | 10.1103/PhysRevD.104.034019 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the transition widths of $\Upsilon(10753)$ and $\Upsilon(11020)$
into standard bottomonium under the hypothesis that they correspond to the two
lowest laying $1^{--}$ hybrid bottomonium states. We employ weakly coupled
potential NRQCD an effective filed theory incorporating the heavy quark and
multipole expansions. We consider the transitions generated by the leading
order and next-to-leading order singlet-octet operators. In the multipole
expansion the heavy quark matrix elements factorize from the production of
light-quark mesons by gluonic operators. For the leading order operator we
compute the widths with a single $\pi^0$, $\eta$ or $\eta'$ in the final state
and for the next-to-leading operator for $\pi^+\pi^-$ or $K^+K^-$. The
hadronization of the gluonic operators is obtained, in the first case, from the
axial anomaly and a standard $\pi^0-\eta-\eta'$ mixing scheme and, in the
second case, we employ a coupled-channel dispersive representation matched to
chiral perturbation theory for both the $S$ and $D$ wave pieces of the gluonic
operator. We compare with experimental values and semi-inclusive widths. Our
results strongly suggest that $\Upsilon(11020)$ is indeed a hybrid bottomonium
state.
| [
{
"created": "Thu, 8 Apr 2021 18:00:02 GMT",
"version": "v1"
},
{
"created": "Tue, 3 Aug 2021 09:07:48 GMT",
"version": "v2"
}
] | 2021-08-25 | [
[
"Castellà",
"Jaume Tarrús",
""
],
[
"Passemar",
"Emilie",
""
]
] | We study the transition widths of $\Upsilon(10753)$ and $\Upsilon(11020)$ into standard bottomonium under the hypothesis that they correspond to the two lowest laying $1^{--}$ hybrid bottomonium states. We employ weakly coupled potential NRQCD an effective filed theory incorporating the heavy quark and multipole expansions. We consider the transitions generated by the leading order and next-to-leading order singlet-octet operators. In the multipole expansion the heavy quark matrix elements factorize from the production of light-quark mesons by gluonic operators. For the leading order operator we compute the widths with a single $\pi^0$, $\eta$ or $\eta'$ in the final state and for the next-to-leading operator for $\pi^+\pi^-$ or $K^+K^-$. The hadronization of the gluonic operators is obtained, in the first case, from the axial anomaly and a standard $\pi^0-\eta-\eta'$ mixing scheme and, in the second case, we employ a coupled-channel dispersive representation matched to chiral perturbation theory for both the $S$ and $D$ wave pieces of the gluonic operator. We compare with experimental values and semi-inclusive widths. Our results strongly suggest that $\Upsilon(11020)$ is indeed a hybrid bottomonium state. |
1709.09542 | Mrinal Kumar Das | Happy Borgohain, Mrinal Kumar Das | Lepton Number Violation, Lepton Flavour Violation and Baryogenesis in
Left-Right Symmetric Model | 34 pages, 12 figures, version accepted for publication in Phys. Rev.
D. arXiv admin note: text overlap with arXiv:1705.00922 | null | 10.1103/PhysRevD.96.075021 | null | hep-ph astro-ph.CO nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We did a model independent phenomenological study of baryogenesis via
leptogenesis, neutrinoless double beta decay (NDBD) and charged lepton flavour
violation (CLFV) in a generic left-right symmetric model (LRSM) where neutrino
mass originates from the type I + type II seesaw mechanism. We studied the new
physics contributions to NDBD coming from the left-right gauge boson mixing and
the heavy neutrino contribution within the framework of LRSM. We have
considered the mass of the RH gauge boson to be specifically 5 TeV, 10 TeV and
18 TeV and studied the effects of the new physics contributions on the
effective mass and baryogenesis and compared with the current experimental
limit. We tried to correlate the cosmological BAU from resonant leptogenesis
with the low energy observables, notably, NDBD and LFV with a view to finding a
common parameter space where they coexists.
| [
{
"created": "Tue, 26 Sep 2017 08:41:57 GMT",
"version": "v1"
}
] | 2017-10-25 | [
[
"Borgohain",
"Happy",
""
],
[
"Das",
"Mrinal Kumar",
""
]
] | We did a model independent phenomenological study of baryogenesis via leptogenesis, neutrinoless double beta decay (NDBD) and charged lepton flavour violation (CLFV) in a generic left-right symmetric model (LRSM) where neutrino mass originates from the type I + type II seesaw mechanism. We studied the new physics contributions to NDBD coming from the left-right gauge boson mixing and the heavy neutrino contribution within the framework of LRSM. We have considered the mass of the RH gauge boson to be specifically 5 TeV, 10 TeV and 18 TeV and studied the effects of the new physics contributions on the effective mass and baryogenesis and compared with the current experimental limit. We tried to correlate the cosmological BAU from resonant leptogenesis with the low energy observables, notably, NDBD and LFV with a view to finding a common parameter space where they coexists. |
1206.5137 | Raghavendra Hundi | R. S. Hundi, Sourov Roy and Soumitra SenGupta | Muon (g-2) from the bulk neutrino field in a warped extra dimensional
model | 18 pages, 3 figures, 2 tables, minor changes, this version has been
published in Physical Review D | null | 10.1103/PhysRevD.86.036014 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the Randall-Sundrum model, a bulk neutrino field in the 5-dimensional
space-time can give rise to tiny Dirac masses to neutrinos. In such a scenario,
we have computed the contribution of the bulk neutrino field to the anomalous
magnetic moment $(g-2)_\mu$ of muon. We have computed this contribution in the
't Hooft-Feynman gauge and have found that the contribution has the right sign
to fit the current discrepancy between the experiment and the standard model
value of $(g-2)_\mu$. We have also studied possible constraints on the model
parameters by including contributions to $(g-2)_\mu$ from other sources such as
bulk gravitons.
| [
{
"created": "Fri, 22 Jun 2012 13:04:46 GMT",
"version": "v1"
},
{
"created": "Mon, 17 Sep 2012 06:05:11 GMT",
"version": "v2"
}
] | 2012-09-18 | [
[
"Hundi",
"R. S.",
""
],
[
"Roy",
"Sourov",
""
],
[
"SenGupta",
"Soumitra",
""
]
] | In the Randall-Sundrum model, a bulk neutrino field in the 5-dimensional space-time can give rise to tiny Dirac masses to neutrinos. In such a scenario, we have computed the contribution of the bulk neutrino field to the anomalous magnetic moment $(g-2)_\mu$ of muon. We have computed this contribution in the 't Hooft-Feynman gauge and have found that the contribution has the right sign to fit the current discrepancy between the experiment and the standard model value of $(g-2)_\mu$. We have also studied possible constraints on the model parameters by including contributions to $(g-2)_\mu$ from other sources such as bulk gravitons. |
2011.02629 | Jian-Hua Gao | Jian-Hua Gao, Zuo-Tang Liang and Qun Wang | Quantum kinetic theory for spin-1/2 fermions in Wigner function
formalism | 32pages, no figures, published version in IJMPA, more references are
added | null | 10.1142/S0217751X21300015 | null | hep-ph hep-th nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We give a brief overview of the kinetic theory for spin-1/2 fermions in
Wigner function formulism. The chiral and spin kinetic equations can be derived
from equations for Wigner functions. A general Wigner function has 16
components which satisfy 32 coupled equations. For massless fermions, the
number of independent equations can be significantly reduced due to the
decoupling of left-handed and right-handed particles. It can be proved that out
of many components of Wigner functions and their coupled equations, only one
kinetic equation for the distribution function is independent. This is called
the disentanglement theorem for Wigner functions of chiral fermions. For
massive fermions, it turns out that one particle distribution function and
three spin distribution functions are independent and satisfy four kinetic
equations. Various chiral and spin effects such as chiral magnetic and votical
effects, the chiral seperation effect, spin polarization effects can be
consistently described in the formalism.
| [
{
"created": "Thu, 5 Nov 2020 02:51:10 GMT",
"version": "v1"
},
{
"created": "Sun, 24 Jan 2021 10:28:15 GMT",
"version": "v2"
}
] | 2021-02-03 | [
[
"Gao",
"Jian-Hua",
""
],
[
"Liang",
"Zuo-Tang",
""
],
[
"Wang",
"Qun",
""
]
] | We give a brief overview of the kinetic theory for spin-1/2 fermions in Wigner function formulism. The chiral and spin kinetic equations can be derived from equations for Wigner functions. A general Wigner function has 16 components which satisfy 32 coupled equations. For massless fermions, the number of independent equations can be significantly reduced due to the decoupling of left-handed and right-handed particles. It can be proved that out of many components of Wigner functions and their coupled equations, only one kinetic equation for the distribution function is independent. This is called the disentanglement theorem for Wigner functions of chiral fermions. For massive fermions, it turns out that one particle distribution function and three spin distribution functions are independent and satisfy four kinetic equations. Various chiral and spin effects such as chiral magnetic and votical effects, the chiral seperation effect, spin polarization effects can be consistently described in the formalism. |
hep-ph/9403303 | null | Marek Pawlowski and Ryszard Raczka, SINS/SISSA | Mass Generation in the Standard Model without Dynamical Higgs Field | 9p, ILAS 2/94, 20kb, Latex | null | null | null | hep-ph | null | We call attention to the fact that the gauge symmetry $SU(3)\times
SU(2)_{_L}\times U(1)$ of the Standard Model can be easily and naturally
extended by the local conformal symmetry connected with the possibility of
choosing the local length scale. Restricting the admissible interactions to the
lowest order conformal invariant interactions one gets the unique form of total
lagrangian. It contains all Standard Model fields and gravitational
interaction. Using the unitary and the conformal gauge conditions we can
eliminate all four real components of the Higgs doublet in this model. However
the masses of vector mesons, leptons and quarks are automatically generated and
are given by the same formulas as in the conventional Standard Model. In this
manner one gets the mass generation without the mechanism of spontaneous
symmetry breaking and without the remaining real dynamical Higgs field.
| [
{
"created": "Thu, 17 Mar 1994 16:39:26 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Pawlowski",
"Marek",
""
],
[
"Raczka",
"Ryszard",
""
],
[
"SINS/SISSA",
"",
""
]
] | We call attention to the fact that the gauge symmetry $SU(3)\times SU(2)_{_L}\times U(1)$ of the Standard Model can be easily and naturally extended by the local conformal symmetry connected with the possibility of choosing the local length scale. Restricting the admissible interactions to the lowest order conformal invariant interactions one gets the unique form of total lagrangian. It contains all Standard Model fields and gravitational interaction. Using the unitary and the conformal gauge conditions we can eliminate all four real components of the Higgs doublet in this model. However the masses of vector mesons, leptons and quarks are automatically generated and are given by the same formulas as in the conventional Standard Model. In this manner one gets the mass generation without the mechanism of spontaneous symmetry breaking and without the remaining real dynamical Higgs field. |
hep-ph/9401327 | Mohammad | Mohammad R. Ahmady and Roberto R. Mendel | A Theoretical Prediction for Exclusive Decays $B \rightarrow K(K^*)
\eta_c$ | 6 pages, LaTex | Z. Phys. C65 (1995) 263-266 | 10.1007/BF01571882 | null | hep-ph | null | The decay rates for the exclusive B decays $B \rightarrow K \eta_c $ and $B
\rightarrow K^* \eta_c$ are calculated in the context of the heavy quark
effective theory. We obtain $\Gamma (B \rightarrow K \eta_c )/\Gamma
(B\rightarrow K\psi )=1.6 \pm 0.2$ and $\Gamma (B\rightarrow K^*\eta_c)/\Gamma
(B \rightarrow K^*\psi )=0.39 \pm 0.04$. These results lead to estimates $BR(B
\rightarrow K \eta_c)=(0.11 \pm 0.02) \% $ and $BR(B \rightarrow K^* \eta_c)=
(0.05 \pm 0.01) \% $ if we use the central current experimental values for
$B\rightarrow (K,K^*)\psi $ branching ratios.
| [
{
"created": "Tue, 25 Jan 1994 19:50:47 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Ahmady",
"Mohammad R.",
""
],
[
"Mendel",
"Roberto R.",
""
]
] | The decay rates for the exclusive B decays $B \rightarrow K \eta_c $ and $B \rightarrow K^* \eta_c$ are calculated in the context of the heavy quark effective theory. We obtain $\Gamma (B \rightarrow K \eta_c )/\Gamma (B\rightarrow K\psi )=1.6 \pm 0.2$ and $\Gamma (B\rightarrow K^*\eta_c)/\Gamma (B \rightarrow K^*\psi )=0.39 \pm 0.04$. These results lead to estimates $BR(B \rightarrow K \eta_c)=(0.11 \pm 0.02) \% $ and $BR(B \rightarrow K^* \eta_c)= (0.05 \pm 0.01) \% $ if we use the central current experimental values for $B\rightarrow (K,K^*)\psi $ branching ratios. |
2103.02072 | Ernest Ma | Ernest Ma (UC Riverside) | Naturally Light Dirac Neutrinos from SU(6) | 8 pages, no figure | null | 10.1007/JHEP07(2021)024 | UCRHEP-T611 (Mar 2021) | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A known mechanism for obtaining naturally light Dirac neutrinos is
implemented in the context of $SU(6) \to SU(5) \times U(1)_N$.
| [
{
"created": "Tue, 2 Mar 2021 22:51:59 GMT",
"version": "v1"
}
] | 2021-07-21 | [
[
"Ma",
"Ernest",
"",
"UC Riverside"
]
] | A known mechanism for obtaining naturally light Dirac neutrinos is implemented in the context of $SU(6) \to SU(5) \times U(1)_N$. |
0912.4270 | Binoy Patra Krishna | Binoy Krishna Patra, Vineet Agotiya and Vinod Chandra | Charmonium suppression in the presence of dissipative forces in a
strongly coupled quark-gluon plasma | 15 double sided pages, 8 figures, 5 tables | Eur.Phys.J.C67:465-477,2010 | 10.1140/epjc/s10052-010-1318-2 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the survival of charmonium states in a strongly-coupled quark-gluon
plasma in the presence of dissipative forces. We consider first-order
dissipative corrections to the plasma equation of motion in the Bjorken
boost-invariant expansion with a strongly-coupled equation of state for QGP and
study the survival of these states with the dissociation temperatures obtained
by correcting the full Cornell potential not its Coulomb part alone with a
dielectric function encoding the effects of deconfined medium. We further
explore the sensitivity of prompt and sequential suppression of these states to
the shear viscosity-to-entropy density ratio, $\eta/s$ from perturbative QCD
and AdS/CFT predictions. Our results show excellent agreement with the recent
experimental results at RHIC.
| [
{
"created": "Tue, 22 Dec 2009 14:27:09 GMT",
"version": "v1"
}
] | 2014-11-20 | [
[
"Patra",
"Binoy Krishna",
""
],
[
"Agotiya",
"Vineet",
""
],
[
"Chandra",
"Vinod",
""
]
] | We study the survival of charmonium states in a strongly-coupled quark-gluon plasma in the presence of dissipative forces. We consider first-order dissipative corrections to the plasma equation of motion in the Bjorken boost-invariant expansion with a strongly-coupled equation of state for QGP and study the survival of these states with the dissociation temperatures obtained by correcting the full Cornell potential not its Coulomb part alone with a dielectric function encoding the effects of deconfined medium. We further explore the sensitivity of prompt and sequential suppression of these states to the shear viscosity-to-entropy density ratio, $\eta/s$ from perturbative QCD and AdS/CFT predictions. Our results show excellent agreement with the recent experimental results at RHIC. |
hep-ph/0409219 | Osamu Seto | Takeshi Nihei, Nobuchika Okada and Osamu Seto | Neutralino dark matter in brane world cosmology | 12 pages, 8 figures | Phys.Rev. D71 (2005) 063535 | 10.1103/PhysRevD.71.063535 | KEK-TH-982 | hep-ph astro-ph | null | The thermal relic density of the neutralino dark matter in the brane world
cosmology is studied. Since the expansion law at a high energy regime in the
brane world cosmology is modified from the one in the standard cosmology, the
resultant relic density can be altered. It has been found that, if the five
dimensional Planck mass $M_5$ is lower than $10^4$ TeV, the brane world
cosmological effect is significant at the decoupling time and the resultant
relic density is enhanced. We calculate the neutralino relic density in the
Constrained Minimal Supersymmetric Standard Model (CMSSM) and show that the
allowed region is dramatically modified from the one in the standard cosmology
and eventually disappears as $M_5$ is decreasing. We also find a new lower
bound on $M_5 \gtrsim 600$ TeV based on the neutralino dark matter hypothesis,
namely the lower bound in order for the allowed region of the neutralino dark
matter to exist.
| [
{
"created": "Mon, 20 Sep 2004 04:24:04 GMT",
"version": "v1"
},
{
"created": "Fri, 1 Apr 2005 09:33:33 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Nihei",
"Takeshi",
""
],
[
"Okada",
"Nobuchika",
""
],
[
"Seto",
"Osamu",
""
]
] | The thermal relic density of the neutralino dark matter in the brane world cosmology is studied. Since the expansion law at a high energy regime in the brane world cosmology is modified from the one in the standard cosmology, the resultant relic density can be altered. It has been found that, if the five dimensional Planck mass $M_5$ is lower than $10^4$ TeV, the brane world cosmological effect is significant at the decoupling time and the resultant relic density is enhanced. We calculate the neutralino relic density in the Constrained Minimal Supersymmetric Standard Model (CMSSM) and show that the allowed region is dramatically modified from the one in the standard cosmology and eventually disappears as $M_5$ is decreasing. We also find a new lower bound on $M_5 \gtrsim 600$ TeV based on the neutralino dark matter hypothesis, namely the lower bound in order for the allowed region of the neutralino dark matter to exist. |
hep-ph/9602236 | Rl Jaffe | Robert L. Jaffe | Spin, Twist and Hadron Structure in Deep Inelastic Processes | 73 pages, 8 LaTex files plus bbl and bib, 33 figures | null | null | MIT-CTP-2506 | hep-ph hep-ex nucl-th | null | These notes provide an introduction to polarization effects in deep inelastic
processes in QCD. We emphasize recent work on transverse asymmetries,
subdominant effects, and the role of polarization in fragmentation and in
purely hadronic processes. After a review of kinematics and some basic tools of
short distance analysis, we study the twist, helicity, chirality and
transversity dependence of a variety of high energy processes sensitive to the
quark and gluon substructure of hadrons.
| [
{
"created": "Tue, 6 Feb 1996 18:44:05 GMT",
"version": "v1"
}
] | 2016-11-07 | [
[
"Jaffe",
"Robert L.",
""
]
] | These notes provide an introduction to polarization effects in deep inelastic processes in QCD. We emphasize recent work on transverse asymmetries, subdominant effects, and the role of polarization in fragmentation and in purely hadronic processes. After a review of kinematics and some basic tools of short distance analysis, we study the twist, helicity, chirality and transversity dependence of a variety of high energy processes sensitive to the quark and gluon substructure of hadrons. |
hep-ph/9601246 | null | Ch. Ritter, B. C. Metsch, C. R. Munz, H. R. Petry | Instanton Effects in the Decay of Scalar Mesons | 9 pages, uuencoded latex including two figures | Phys.Lett. B380 (1996) 431-436 | 10.1016/0370-2693(96)00622-3 | Bonn Tk-96-03 | hep-ph | null | We show that instanton effects may play a crucial role in the decay of scalar
mesons into two pseudoscalars. Particularly the branching ratios of two meson
decays of the $f_0(1500)$, which is considered as a glue-ball candidate, are
then compatible with an ordinary $q \bar{q}$-structure of this resonance and a
small positive SU(3) mixing angle, close to a result recently calculated with
the same instanton-induced force.
| [
{
"created": "Thu, 11 Jan 1996 17:56:19 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Ritter",
"Ch.",
""
],
[
"Metsch",
"B. C.",
""
],
[
"Munz",
"C. R.",
""
],
[
"Petry",
"H. R.",
""
]
] | We show that instanton effects may play a crucial role in the decay of scalar mesons into two pseudoscalars. Particularly the branching ratios of two meson decays of the $f_0(1500)$, which is considered as a glue-ball candidate, are then compatible with an ordinary $q \bar{q}$-structure of this resonance and a small positive SU(3) mixing angle, close to a result recently calculated with the same instanton-induced force. |
1102.3597 | Ilya Gorbunov N | G.A. Kozlov | Correlations of two photons at hadron colliders | 10 pages, 1 figure | null | 10.1142/S0217732311036413 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the Bose-Einstein correlations of two photons and their coherent
properties that can provide the information about the space-time structure of
the emitting source through the Higgs-boson decays into two photons. We argue
that such an investigation could probe the Higgs-boson mass. The model is
rather sensitive to the temperature of the environment and to the external
distortion effect in medium.
| [
{
"created": "Thu, 17 Feb 2011 14:57:42 GMT",
"version": "v1"
}
] | 2015-05-27 | [
[
"Kozlov",
"G. A.",
""
]
] | We study the Bose-Einstein correlations of two photons and their coherent properties that can provide the information about the space-time structure of the emitting source through the Higgs-boson decays into two photons. We argue that such an investigation could probe the Higgs-boson mass. The model is rather sensitive to the temperature of the environment and to the external distortion effect in medium. |
2101.01191 | Shuang-Yong Zhou | Xu Li, Hao Xu, Chengjie Yang, Cen Zhang, Shuang-Yong Zhou | Positivity in Multi-Field EFTs | 5 pages + refs + supplementary material, 5 figures; to appear in PRL | Phys. Rev. Lett. 127, 121601 (2021) | 10.1103/PhysRevLett.127.121601 | USTC-ICTS/PCFT-21-01 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss the general method for obtaining full positivity bounds on
multi-field effective field theories (EFTs). While the leading order forward
positivity bounds are commonly derived from the elastic scattering of two
(superposed) external states, we show that for a generic EFT containing 3 or
more low-energy modes, this approach only gives incomplete bounds. We then
identify the allowed parameter space as the dual to a spectrahedron,
constructed from crossing symmetries of the amplitude, and show that finding
the optimal bounds for a given number of modes is equivalent to a geometric
problem: finding the extremal rays of a spectrahedron. We show how this is done
analytically for simple cases, and numerically formulated as semidefinite
programming (SDP) problems for more complicated cases. We demonstrate this
approach with a number of well-motivated examples in particle physics and
cosmology, including EFTs of scalars, vectors, fermions and gravitons. In all
these cases, we find that the SDP approach leads to results that either improve
the previous ones or are completely new. We also find that the SDP approach is
numerically much more efficient.
| [
{
"created": "Mon, 4 Jan 2021 19:00:03 GMT",
"version": "v1"
},
{
"created": "Wed, 25 Aug 2021 14:57:42 GMT",
"version": "v2"
}
] | 2021-09-22 | [
[
"Li",
"Xu",
""
],
[
"Xu",
"Hao",
""
],
[
"Yang",
"Chengjie",
""
],
[
"Zhang",
"Cen",
""
],
[
"Zhou",
"Shuang-Yong",
""
]
] | We discuss the general method for obtaining full positivity bounds on multi-field effective field theories (EFTs). While the leading order forward positivity bounds are commonly derived from the elastic scattering of two (superposed) external states, we show that for a generic EFT containing 3 or more low-energy modes, this approach only gives incomplete bounds. We then identify the allowed parameter space as the dual to a spectrahedron, constructed from crossing symmetries of the amplitude, and show that finding the optimal bounds for a given number of modes is equivalent to a geometric problem: finding the extremal rays of a spectrahedron. We show how this is done analytically for simple cases, and numerically formulated as semidefinite programming (SDP) problems for more complicated cases. We demonstrate this approach with a number of well-motivated examples in particle physics and cosmology, including EFTs of scalars, vectors, fermions and gravitons. In all these cases, we find that the SDP approach leads to results that either improve the previous ones or are completely new. We also find that the SDP approach is numerically much more efficient. |
hep-ph/0408054 | Wolfgang Sch\"afer | N.N. Nikolaev, W. Sch\"afer, B.G. Zakharov, and V.R. Zoller | Color dipoles and k_t factorization for nuclei | 4 pp., 1 eps-fig. Talk given at 12th International Workshop on Deep
Inelastic Scattering (DIS 2004), Strbske Pleso, Slovakia, 14-18 Apr 2004 | null | null | null | hep-ph | null | We discuss applications of the color dipole approach to hard processes on
nuclei. We focus on the relation to k_t--factorisation and the role of a
nuclear unintegrated gluon distribution in single-- and two-- particle
inclusive spectra in \gamma^*A and pA collisions. Linear k_t factorisation is
broken for a wide class of observables, which we exemplify on the case of heavy
quark p_t--spectra.
| [
{
"created": "Wed, 4 Aug 2004 10:59:50 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Nikolaev",
"N. N.",
""
],
[
"Schäfer",
"W.",
""
],
[
"Zakharov",
"B. G.",
""
],
[
"Zoller",
"V. R.",
""
]
] | We discuss applications of the color dipole approach to hard processes on nuclei. We focus on the relation to k_t--factorisation and the role of a nuclear unintegrated gluon distribution in single-- and two-- particle inclusive spectra in \gamma^*A and pA collisions. Linear k_t factorisation is broken for a wide class of observables, which we exemplify on the case of heavy quark p_t--spectra. |
hep-ph/9305261 | Neil Turok | David Coulson, Ue-Li Pen and Neil Turok | Degree Scale Microwave Anisotropies in NonGaussian Theories of Cosmic
Structure Formation | 13 pages, TeX, figure 2 appended as a postscript file, figures 1a-e
available by anonymous ftp (color postscript files), PUP-TH-93/1393 | null | null | null | hep-ph astro-ph | null | The COBE satellite's maps of the cosmic microwave background (CMB) anisotropy
do not have the resolution to discriminate between theories of cosmic structure
formation based on inflation, and those based on field ordering following a
symmetry breaking phase transition. For this purpose it is critical to resolve
the CMB anisotropy on degree scales. In this paper we report on detailed
calculations of the degree scale anisotropies predicted in the global string,
monopole, texture and nontopological texture scenarios of structure formation,
emphasising their distinct character from those predicted by inflation, and
commenting on the prospects of their detection in the near future.
| [
{
"created": "Thu, 13 May 1993 23:00:44 GMT",
"version": "v1"
}
] | 2009-09-25 | [
[
"Coulson",
"David",
""
],
[
"Pen",
"Ue-Li",
""
],
[
"Turok",
"Neil",
""
]
] | The COBE satellite's maps of the cosmic microwave background (CMB) anisotropy do not have the resolution to discriminate between theories of cosmic structure formation based on inflation, and those based on field ordering following a symmetry breaking phase transition. For this purpose it is critical to resolve the CMB anisotropy on degree scales. In this paper we report on detailed calculations of the degree scale anisotropies predicted in the global string, monopole, texture and nontopological texture scenarios of structure formation, emphasising their distinct character from those predicted by inflation, and commenting on the prospects of their detection in the near future. |
1610.05040 | Andreas Ringwald | Andreas Ringwald | SM*A*S*H | 6 pages, 4 figures, contributed to the 12th Patras Workshop on
Axions, WIMPs and WISPs, Jeju Island, South Korea, June 20 to 26, 2016 | null | null | DESY 16-195 | hep-ph astro-ph.CO hep-th | http://creativecommons.org/licenses/by/4.0/ | We present a minimal model for particle physics and cosmology. The Standard
Model (SM) particle content is extended by three right-handed SM-singlet
neutrinos N_i and a vector-like quark Q, all of them being charged under a
global lepton number and Peccei-Quinn (PQ) U(1) symmetry which is spontaneously
broken by the vacuum expectation value v_sigma around 10^{11} GeV of a
SM-singlet complex scalar field sigma. Five fundamental problems -- neutrino
oscillations, baryogenesis, dark matter, inflation, strong CP problem -- are
solved at one stroke in this model, dubbed "SM*A*S*H" (Standard
Model*Axion*Seesaw*Higgs portal inflation). It can be probed decisively by
upcoming cosmic microwave background and axion dark matter experiments.
| [
{
"created": "Mon, 17 Oct 2016 10:46:09 GMT",
"version": "v1"
}
] | 2016-10-18 | [
[
"Ringwald",
"Andreas",
""
]
] | We present a minimal model for particle physics and cosmology. The Standard Model (SM) particle content is extended by three right-handed SM-singlet neutrinos N_i and a vector-like quark Q, all of them being charged under a global lepton number and Peccei-Quinn (PQ) U(1) symmetry which is spontaneously broken by the vacuum expectation value v_sigma around 10^{11} GeV of a SM-singlet complex scalar field sigma. Five fundamental problems -- neutrino oscillations, baryogenesis, dark matter, inflation, strong CP problem -- are solved at one stroke in this model, dubbed "SM*A*S*H" (Standard Model*Axion*Seesaw*Higgs portal inflation). It can be probed decisively by upcoming cosmic microwave background and axion dark matter experiments. |
1011.4743 | Stefano Scopel | N. Fornengo (Univ. of Torino and INFN), S. Scopel (Sogang Univ.) and
A. Bottino (Univ. of Torino and INFN) | Discussing direct search of dark matter particles in the Minimal
Supersymmetric extension of the Standard Model with light neutralinos | 23 pages, 25 figures, typeset with ReVTeX4. One short section on
indirect searches and a few references added. A version of the paper with
full resolution figures can be found at
http://www.to.infn.it/~scopel/light_2010.pdf | Phys.Rev.D83:015001,2011 | 10.1103/PhysRevD.83.015001 | DFTT 19/2010 | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We examine the status of light neutralinos in an effective Minimal
Supersymmetric extension of the Standard Model (MSSM) at the electroweak scale
which was considered in the past and discussed in terms of the available data
of direct searches for dark matter (DM) particles. Our reanalysis is prompted
by new measurements at the Tevatron and B-factories which might potentially
provide significant constraints on the MSSM model. Here we examine in detail
all these new data and show that the present published results from the
Tevatron and B-factories have only a mild effect on the original light
neutralino population. This population, which fits quite well the DAMA/LIBRA
annual modulation data, would also agree with the preliminary results of CDMS,
CoGeNT and CRESST, should these data, which are at present only hints or
excesses of events over the expected backgrounds, be interpreted as authentic
signals of DM. For the neutralino mass we find a lower bound of 7-8 GeV. Our
results differ from some recent conclusions by other authors because of a few
crucial points which we try to single out and elucidate.
| [
{
"created": "Mon, 22 Nov 2010 07:07:59 GMT",
"version": "v1"
},
{
"created": "Wed, 15 Dec 2010 05:31:38 GMT",
"version": "v2"
}
] | 2011-02-25 | [
[
"Fornengo",
"N.",
"",
"Univ. of Torino and INFN"
],
[
"Scopel",
"S.",
"",
"Sogang Univ."
],
[
"Bottino",
"A.",
"",
"Univ. of Torino and INFN"
]
] | We examine the status of light neutralinos in an effective Minimal Supersymmetric extension of the Standard Model (MSSM) at the electroweak scale which was considered in the past and discussed in terms of the available data of direct searches for dark matter (DM) particles. Our reanalysis is prompted by new measurements at the Tevatron and B-factories which might potentially provide significant constraints on the MSSM model. Here we examine in detail all these new data and show that the present published results from the Tevatron and B-factories have only a mild effect on the original light neutralino population. This population, which fits quite well the DAMA/LIBRA annual modulation data, would also agree with the preliminary results of CDMS, CoGeNT and CRESST, should these data, which are at present only hints or excesses of events over the expected backgrounds, be interpreted as authentic signals of DM. For the neutralino mass we find a lower bound of 7-8 GeV. Our results differ from some recent conclusions by other authors because of a few crucial points which we try to single out and elucidate. |
0710.2341 | Louis J. Clavelli | L. Clavelli | Extended Higgs Models and a Transition to Exact Susy | Submitted for the SUSY07 proceedings, 4 pages, LaTeX, 1 eps figure | null | null | null | hep-ph | null | String landscape ideas and the observation of a positive vacuum energy in the
current universe suggest that there could be a future transition to an exactly
supersymmetric world. Atomic and molecular binding in this susy background
probably require that electroweak symmetry breaking survives the transition.
Among several susy higgs models that have been discussed, one stands out in
this regard. Thus, the higgs structure that is revealed at the LHC could have
strong consequences for the type of bulk matter that may arise in a future susy
universe.
| [
{
"created": "Thu, 11 Oct 2007 20:08:50 GMT",
"version": "v1"
}
] | 2007-10-15 | [
[
"Clavelli",
"L.",
""
]
] | String landscape ideas and the observation of a positive vacuum energy in the current universe suggest that there could be a future transition to an exactly supersymmetric world. Atomic and molecular binding in this susy background probably require that electroweak symmetry breaking survives the transition. Among several susy higgs models that have been discussed, one stands out in this regard. Thus, the higgs structure that is revealed at the LHC could have strong consequences for the type of bulk matter that may arise in a future susy universe. |
1410.6497 | David Feld | Matthew R. Buckley, David Feld, Dorival Goncalves | Scalar Simplified Models for Dark Matter | 20 pages, 13 figures | null | 10.1103/PhysRevD.91.015017 | IPPP/14/92, DCPT/14/184 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We introduce a set of minimal simplified models for dark matter interactions
with the Standard Model, connecting the two sectors via either a scalar or
pseudoscalar particle. These models have a wider regime of validity for dark
matter searches at the LHC than the effective field theory approach, while
still allowing straightforward comparison to results from non-collider dark
matter detection experiments. Such models also motivate dark matter searches in
multiple correlated channels. In this paper, we constrain scalar and
pseudoscalar simplified models with direct and indirect detection experiments,
as well as from existing LHC searches with missing energy plus tops, bottoms,
or jets, using the exact loop-induced coupling with gluons. This calculation
significantly affects key differential cross sections at the LHC, and must be
properly included. We make connections with the Higgs sector, and conclude with
a discussion of future searches at the LHC.
| [
{
"created": "Thu, 23 Oct 2014 20:36:26 GMT",
"version": "v1"
},
{
"created": "Sun, 21 Dec 2014 19:25:11 GMT",
"version": "v2"
}
] | 2015-06-23 | [
[
"Buckley",
"Matthew R.",
""
],
[
"Feld",
"David",
""
],
[
"Goncalves",
"Dorival",
""
]
] | We introduce a set of minimal simplified models for dark matter interactions with the Standard Model, connecting the two sectors via either a scalar or pseudoscalar particle. These models have a wider regime of validity for dark matter searches at the LHC than the effective field theory approach, while still allowing straightforward comparison to results from non-collider dark matter detection experiments. Such models also motivate dark matter searches in multiple correlated channels. In this paper, we constrain scalar and pseudoscalar simplified models with direct and indirect detection experiments, as well as from existing LHC searches with missing energy plus tops, bottoms, or jets, using the exact loop-induced coupling with gluons. This calculation significantly affects key differential cross sections at the LHC, and must be properly included. We make connections with the Higgs sector, and conclude with a discussion of future searches at the LHC. |
hep-ph/0701022 | Xiang Liu | Xiang Liu, Bo Zhang, Lei-Lei Shen and Shi-Lin Zhu | X(1576) and the Final State Interaction Effect | 6 pages, 4 figures. Some typos corrected, more discussion and
references added | Phys.Rev.D75:074017,2007 | 10.1103/PhysRevD.75.074017 | null | hep-ph hep-ex | null | We study whether the broad peak X(1576) observed by BES Collaboration arises
from the final state interaction effect of $\rho(1450,1700)$ decays. The
interference effect could produce an enhancement around 1540 MeV in the
$K^+K^-$ spectrum with typical interference phases. However, the branching
ratio $B[J/\psi\to \pi^{0}\rho(1450,1700)]\cdot B[\rho(1450,1700)\to
K^{+}K^{-}]$ from the final state interaction effect is far less than the
experimental data.
| [
{
"created": "Thu, 4 Jan 2007 02:12:59 GMT",
"version": "v1"
},
{
"created": "Wed, 7 Mar 2007 03:08:18 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Liu",
"Xiang",
""
],
[
"Zhang",
"Bo",
""
],
[
"Shen",
"Lei-Lei",
""
],
[
"Zhu",
"Shi-Lin",
""
]
] | We study whether the broad peak X(1576) observed by BES Collaboration arises from the final state interaction effect of $\rho(1450,1700)$ decays. The interference effect could produce an enhancement around 1540 MeV in the $K^+K^-$ spectrum with typical interference phases. However, the branching ratio $B[J/\psi\to \pi^{0}\rho(1450,1700)]\cdot B[\rho(1450,1700)\to K^{+}K^{-}]$ from the final state interaction effect is far less than the experimental data. |
hep-ph/0401146 | Raimund Str\"ohmer | Raimund Str\"ohmer | Review of the Properties of the W Boson at LEP, and the Precision
Determination of its Mass | 97 pages | Int.J.Mod.Phys. A18 (2003) 5127-5220 | 10.1142/S0217751X03015180 | null | hep-ph hep-ex | null | We review the precision measurement of the mass and couplings of the W Boson
at LEP. The total and differential W+W- cross section is used to extract the
WWZ and WWgamma couplings. We discuss the techniques used by the four LEP
experiments to determine the W mass in different decay channels, and present
the details of methods used to evaluate the sources of systematic uncertainty.
| [
{
"created": "Tue, 20 Jan 2004 15:06:27 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Ströhmer",
"Raimund",
""
]
] | We review the precision measurement of the mass and couplings of the W Boson at LEP. The total and differential W+W- cross section is used to extract the WWZ and WWgamma couplings. We discuss the techniques used by the four LEP experiments to determine the W mass in different decay channels, and present the details of methods used to evaluate the sources of systematic uncertainty. |
2404.19008 | Peter Arnold | Peter Arnold, Omar Elgedawy, Shahin Iqbal | Strongly vs. weakly coupled in-medium showers: energy stopping in
large-$N_f$ QED | 48 pages, 14 figures | null | null | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Inside a medium, showers originating from a very high-energy particle may
develop via medium-induced splitting processes such as hard bremsstrahlung or
pair production. During shower development, two consecutive splittings
sometimes overlap quantum mechanically, so that they cannot be treated
independently. Some of these effects can be absorbed into an effective value of
a medium parameter known as $\hat q$. Previous calculations (with certain
simplifying assumptions) have found that, after adjusting the value of $\hat
q$, the leftover effect of overlapping splittings is quite small for purely
gluonic large-$N_c$ showers but is very much larger for large-$N_f$ QED
showers, at comparable values of $N\alpha$. Those works did not quite make for
apples-to-apples comparisons: the gluon shower work investigated energy
deposition from a gluon-initiated shower, whereas the QED work investigated
charge-deposition from an electron-initiated shower. As a first step to tighten
up the comparison, this paper investigates energy deposition in the QED case.
Along the way, we develop a framework that should be useful in the future to
explore whether the very small effect of overlapping splitting in purely
gluonic showers is an artifact of having ignored quarks.
| [
{
"created": "Mon, 29 Apr 2024 18:00:04 GMT",
"version": "v1"
}
] | 2024-05-01 | [
[
"Arnold",
"Peter",
""
],
[
"Elgedawy",
"Omar",
""
],
[
"Iqbal",
"Shahin",
""
]
] | Inside a medium, showers originating from a very high-energy particle may develop via medium-induced splitting processes such as hard bremsstrahlung or pair production. During shower development, two consecutive splittings sometimes overlap quantum mechanically, so that they cannot be treated independently. Some of these effects can be absorbed into an effective value of a medium parameter known as $\hat q$. Previous calculations (with certain simplifying assumptions) have found that, after adjusting the value of $\hat q$, the leftover effect of overlapping splittings is quite small for purely gluonic large-$N_c$ showers but is very much larger for large-$N_f$ QED showers, at comparable values of $N\alpha$. Those works did not quite make for apples-to-apples comparisons: the gluon shower work investigated energy deposition from a gluon-initiated shower, whereas the QED work investigated charge-deposition from an electron-initiated shower. As a first step to tighten up the comparison, this paper investigates energy deposition in the QED case. Along the way, we develop a framework that should be useful in the future to explore whether the very small effect of overlapping splitting in purely gluonic showers is an artifact of having ignored quarks. |
hep-ph/0611261 | Thomas Schwetz | Thomas Schwetz | Comparison of the CERN-MEMPHYS and T2HK neutrino oscillation experiments | Talk given at NOW 2006, 9-16 Sep 2006, Conca Specchiulla, Otranto,
Italy, 3 pages, 2 figures | Nucl.Phys.Proc.Suppl.168:202-204,2007 | 10.1016/j.nuclphysbps.2007.02.051 | CERN-PH-TH/2006-241 | hep-ph | null | In this talk I compare the physics potential of possible future neutrino
oscillation experiments from CERN to a Mt scale water Cerenkov detector at
Frejus (MEMPHYS) and of the T2HK proposal in Japan, where for the CERN
experiments an SPL Superbeam and a $\gamma=100$ Beta Beam are considered.
| [
{
"created": "Mon, 20 Nov 2006 14:27:35 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Schwetz",
"Thomas",
""
]
] | In this talk I compare the physics potential of possible future neutrino oscillation experiments from CERN to a Mt scale water Cerenkov detector at Frejus (MEMPHYS) and of the T2HK proposal in Japan, where for the CERN experiments an SPL Superbeam and a $\gamma=100$ Beta Beam are considered. |
hep-ph/0307241 | Edward W. Kolb | Edward W. Kolb, Alessio Notari, Antonio Riotto | On the reheating stage after inflation | 8 pages, 2 figures. Submitted for publication in Phys. Rev. D | Phys.Rev. D68 (2003) 123505 | 10.1103/PhysRevD.68.123505 | FERMILAB-Pub-03/212-A | hep-ph astro-ph | null | We point out that inflaton decay products acquire plasma masses during the
reheating phase following inflation. The plasma masses may render inflaton
decay kinematicaly forbidden, causing the temperature to remain frozen for a
period at a plateau value. We show that the final reheating temperature may be
uniquely determined by the inflaton mass, and may not depend on its coupling.
Our findings have important implications for the thermal production of
dangerous relics during reheating (e.g., gravitinos), for extracting bounds on
particle physics models of inflation from Cosmic Microwave Background
anisotropy data, for the production of massive dark matter candidates during
reheating, and for models of baryogenesis or leptogensis where massive
particles are produced during reheating.
| [
{
"created": "Fri, 18 Jul 2003 18:53:02 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Kolb",
"Edward W.",
""
],
[
"Notari",
"Alessio",
""
],
[
"Riotto",
"Antonio",
""
]
] | We point out that inflaton decay products acquire plasma masses during the reheating phase following inflation. The plasma masses may render inflaton decay kinematicaly forbidden, causing the temperature to remain frozen for a period at a plateau value. We show that the final reheating temperature may be uniquely determined by the inflaton mass, and may not depend on its coupling. Our findings have important implications for the thermal production of dangerous relics during reheating (e.g., gravitinos), for extracting bounds on particle physics models of inflation from Cosmic Microwave Background anisotropy data, for the production of massive dark matter candidates during reheating, and for models of baryogenesis or leptogensis where massive particles are produced during reheating. |
1801.03826 | Debasish Das | Leonard S. Kisslinger, Debasish Das | Heavy quark state production and suppression via Xe-Xe collisions at
$\sqrt{s_{pp}}$=5.44 TeV | 7 pages,4 figures | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We estimate differential rapidity cross sections for $J/\Psi$, $\Psi(2S)$,
$\Upsilon(1S)$, $\Upsilon(2S)$, and $\Upsilon(3S)$ production; and $\Psi(2S)$
to $J/\Psi(1S)$, $\Upsilon(3S)$ to $\Upsilon(1S)$ suppression via Xe-Xe
collisions at proton-proton energy $\equiv \sqrt{s_{pp}}$ =5.44 TeV. For the
$\Psi(2S)$, $\Upsilon(3S)$ states we use the mixed heavy quark hybrid theory,
with these states being approximately 50\% standard and 50\% hybrid charmonium,
bottomonium meson states.
| [
{
"created": "Thu, 11 Jan 2018 15:44:24 GMT",
"version": "v1"
},
{
"created": "Tue, 12 Mar 2019 18:38:22 GMT",
"version": "v2"
},
{
"created": "Tue, 7 May 2019 15:53:11 GMT",
"version": "v3"
},
{
"created": "Fri, 3 Mar 2023 16:22:33 GMT",
"version": "v4"
}
] | 2023-03-06 | [
[
"Kisslinger",
"Leonard S.",
""
],
[
"Das",
"Debasish",
""
]
] | We estimate differential rapidity cross sections for $J/\Psi$, $\Psi(2S)$, $\Upsilon(1S)$, $\Upsilon(2S)$, and $\Upsilon(3S)$ production; and $\Psi(2S)$ to $J/\Psi(1S)$, $\Upsilon(3S)$ to $\Upsilon(1S)$ suppression via Xe-Xe collisions at proton-proton energy $\equiv \sqrt{s_{pp}}$ =5.44 TeV. For the $\Psi(2S)$, $\Upsilon(3S)$ states we use the mixed heavy quark hybrid theory, with these states being approximately 50\% standard and 50\% hybrid charmonium, bottomonium meson states. |
hep-ph/9909318 | Oliver Haug | O. Haug, J.D. Vergados, Amand Faessler and S. Kovalenko | Neutrino Oscillations and R-parity Violating Supersymmetry | 19 pages, 1 figure; additional references included, minor corrections
and typos fixed. Version to appear in Nucl.Phys. B | Nucl.Phys. B565 (2000) 38-48 | 10.1016/S0550-3213(99)00695-1 | null | hep-ph | null | Using the neutrino oscillations and neutrinoless double beta decay
experimental data we reconstructed an upper limit for the three generation
neutrino mass matrix. We compared this matrix with the predictions of the
minimal supersymmetric(SUSY) model with R-parity violation(\rp) and extracted
stringent limits on trilinear \rp coupling constants $\lambda_{i33},
\lambda'_{i33}$. Introducing an additional $U(1)_X$ flavor symmetry which had
been successful in explaining to relate various \rp parameters. In this model
we found a unique scenario for the neutrino masses and the \rp couplings
compatible with the neutrino oscillation data. Then we derived predictions for
certain experimentally interesting observables.
| [
{
"created": "Fri, 10 Sep 1999 11:14:50 GMT",
"version": "v1"
},
{
"created": "Fri, 15 Oct 1999 08:40:15 GMT",
"version": "v2"
},
{
"created": "Mon, 13 Dec 1999 14:47:42 GMT",
"version": "v3"
}
] | 2009-10-31 | [
[
"Haug",
"O.",
""
],
[
"Vergados",
"J. D.",
""
],
[
"Faessler",
"Amand",
""
],
[
"Kovalenko",
"S.",
""
]
] | Using the neutrino oscillations and neutrinoless double beta decay experimental data we reconstructed an upper limit for the three generation neutrino mass matrix. We compared this matrix with the predictions of the minimal supersymmetric(SUSY) model with R-parity violation(\rp) and extracted stringent limits on trilinear \rp coupling constants $\lambda_{i33}, \lambda'_{i33}$. Introducing an additional $U(1)_X$ flavor symmetry which had been successful in explaining to relate various \rp parameters. In this model we found a unique scenario for the neutrino masses and the \rp couplings compatible with the neutrino oscillation data. Then we derived predictions for certain experimentally interesting observables. |
1508.07595 | Wolfgang Lucha | Wolfgang Lucha, Dmitri Melikhov, Silvano Simula | Precise Ratios of Decay Constants of Vector over Pseudoscalar $B_{(s)}$
Mesons | 7 pages, 2 figures, contributed to "The European Physical Society
Conference on High Energy Physics - EPS-HEP 2015" (22 - 29 July 2015, Vienna,
Austria) | PoS EPS-HEP2015 (2015) 532 | null | HEPHY-PUB 955/15 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The relative magnitude of the decay constants of the pseudoscalar and vector
beauty mesons poses (in contrast to the case of charmed mesons) a long-standing
puzzle. We revisit this problem within the framework of our recent improvements
of the QCD sum-rule formalism for relating observable properties of mesons to
quantum chromodynamics and are led to conclude that the decay constants of the
beauty vector mesons are undoubtedly smaller than those of their pseudoscalar
counterparts.
| [
{
"created": "Sun, 30 Aug 2015 16:18:30 GMT",
"version": "v1"
}
] | 2015-09-01 | [
[
"Lucha",
"Wolfgang",
""
],
[
"Melikhov",
"Dmitri",
""
],
[
"Simula",
"Silvano",
""
]
] | The relative magnitude of the decay constants of the pseudoscalar and vector beauty mesons poses (in contrast to the case of charmed mesons) a long-standing puzzle. We revisit this problem within the framework of our recent improvements of the QCD sum-rule formalism for relating observable properties of mesons to quantum chromodynamics and are led to conclude that the decay constants of the beauty vector mesons are undoubtedly smaller than those of their pseudoscalar counterparts. |
1412.8677 | James Pinfold | James L. Pinfold | The Search for Magnetic Monopoles | null | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | After a short historical introduction and description of the properties of
the magnetic monopole we briefly discuss the search for monopoles produced at
accelerators and from the cosmos. We present in a little more detail the latest
LHC experiment, MoEDAL, specifically designed to continue the search for the
magnetic monopole and other highly ionizing messengers of new physics at the
TeV scale. Lastly we mention a proposal to continue the search for monopoles
with flux below the Parker Bound up to the GUT scale at a high altitude
laboratory.
| [
{
"created": "Tue, 30 Dec 2014 16:43:03 GMT",
"version": "v1"
}
] | 2014-12-31 | [
[
"Pinfold",
"James L.",
""
]
] | After a short historical introduction and description of the properties of the magnetic monopole we briefly discuss the search for monopoles produced at accelerators and from the cosmos. We present in a little more detail the latest LHC experiment, MoEDAL, specifically designed to continue the search for the magnetic monopole and other highly ionizing messengers of new physics at the TeV scale. Lastly we mention a proposal to continue the search for monopoles with flux below the Parker Bound up to the GUT scale at a high altitude laboratory. |
0807.0831 | Rena Ciftci | R. Ciftci, A. K. Ciftci, S. Sultansoy | Possible impact of the fourth generation quarks on production of a
charged Higgs boson at the LHC | 10 pages, 5 figures, 2 tables | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the impact of the fourth generation quarks on production and
decays of the charged Higgs boson at CERN Large Hadron Collider (LHC) with
triple $b$-tagging. The signal is the process $gg\to \bar{u_4}u_4$, followed by
$\bar{u_4}\to W^{-} \bar{b}$ and $u_4\to h^{+} b$ decays with subsequent
$h^{+}\to t \bar{b}$ and corresponding hermitic conjugates. It is shown that,
if $m_{u_{4}}= 400$ GeV, considered process will provide unique opportunity to
discover charged Higgs boson with mass range of 200 to 350 GeV at the first
years of the LHC run.
| [
{
"created": "Fri, 4 Jul 2008 23:00:50 GMT",
"version": "v1"
}
] | 2008-07-08 | [
[
"Ciftci",
"R.",
""
],
[
"Ciftci",
"A. K.",
""
],
[
"Sultansoy",
"S.",
""
]
] | We investigate the impact of the fourth generation quarks on production and decays of the charged Higgs boson at CERN Large Hadron Collider (LHC) with triple $b$-tagging. The signal is the process $gg\to \bar{u_4}u_4$, followed by $\bar{u_4}\to W^{-} \bar{b}$ and $u_4\to h^{+} b$ decays with subsequent $h^{+}\to t \bar{b}$ and corresponding hermitic conjugates. It is shown that, if $m_{u_{4}}= 400$ GeV, considered process will provide unique opportunity to discover charged Higgs boson with mass range of 200 to 350 GeV at the first years of the LHC run. |
hep-ph/0611238 | Igor Strakovsky | Ya. Azimov (PNPI), V. Kuznetsov (INR and Kyungpook National
University), M. V. Polyakov (PNPI and Ruhr-Universitaet), I. Strakovsky (GWU) | K*-couplings for the antidecuplet excitation | 9 pages, 1 figure. Minor changes in text and abstract, references
added; version to appear in Phys. Rev. D | Phys.Rev.D75:054014,2007 | 10.1103/PhysRevD.75.054014 | null | hep-ph hep-ex nucl-ex nucl-th | null | We estimate the coupling of the K* vector meson to the N-->Theta+ transition
employing unitary symmetry, vector meson dominance, and results from the GRAAL
Collaboration for eta photoproduction off the neutron. Our small numerical
value for the coupling constant is consistent with the non-observation of the
Theta+ in recent CLAS searches for its photoproduction. We also estimate the
K*-coupling for the N-->Sigma* excitation, with Sigma* being the Sigma-like
antidecuplet partner of the Theta+-baryon.
| [
{
"created": "Fri, 17 Nov 2006 17:52:07 GMT",
"version": "v1"
},
{
"created": "Sun, 26 Nov 2006 19:13:53 GMT",
"version": "v2"
},
{
"created": "Mon, 26 Feb 2007 13:50:52 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Azimov",
"Ya.",
"",
"PNPI"
],
[
"Kuznetsov",
"V.",
"",
"INR and Kyungpook National\n University"
],
[
"Polyakov",
"M. V.",
"",
"PNPI and Ruhr-Universitaet"
],
[
"Strakovsky",
"I.",
"",
"GWU"
]
] | We estimate the coupling of the K* vector meson to the N-->Theta+ transition employing unitary symmetry, vector meson dominance, and results from the GRAAL Collaboration for eta photoproduction off the neutron. Our small numerical value for the coupling constant is consistent with the non-observation of the Theta+ in recent CLAS searches for its photoproduction. We also estimate the K*-coupling for the N-->Sigma* excitation, with Sigma* being the Sigma-like antidecuplet partner of the Theta+-baryon. |
2104.00376 | Toru Kojo | Toru Kojo | Neutral and charged mesons in magnetic fields: A resonance gas in a
non-relativistic quark model | 14 pages, 9 figures; A contribution to the topical issue "The QCD
Phase Diagram in Strong Magnetic Fields"; v2 revised, 18 pages, 10 figures,
comparisons with the lattice results were added | null | null | null | hep-ph hep-lat nucl-th | http://creativecommons.org/licenses/by/4.0/ | We analyze mesons in constant magnetic fields ($B$) within a non-relativistic
constituent quark model. Our quark model contains a harmonic oscillator type
confining potential, and we perturbatively treat short range correlations to
account for the spin-flavor energy splittings. We study both neutral and
charged mesons taking into account the internal quark dynamics. The neutral
states are labelled by two-dimensional momenta for magnetic translations, while
the charged states by two discrete indices related to angular momenta. For $B
\ll \Lambda_{\rm QCD}^2$ ($\Lambda_{\rm QCD} \sim 200$ MeV: the QCD scale), the
analyses proceed as in usual quark models, while special precautions are needed
for strong fields, $B \sim \Lambda_{QCD}^2$, especially when we treat short
range correlations such as the Fermi-Breit-Pauli interactions. We compute the
energy spectra of mesons up to energies of $\sim 2.5$ GeV and use them to
construct the meson resonance gas. Within the assumption that the constituent
quark masses are insensitive to magnetic fields, the phase space enhancement
for mesons significantly increases the entropy, assisting a transition from a
hadron gas to a quark gluon plasma. We confront our results with the lattice
data, finding reasonable agreement for the low-lying spectra and the entropy
density at low temperature less than $\sim 100$ MeV, but our results at higher
energy scale suffer from artifacts of our confining potential and
non-relativistic treatments.
| [
{
"created": "Thu, 1 Apr 2021 10:11:15 GMT",
"version": "v1"
},
{
"created": "Tue, 2 Nov 2021 08:59:34 GMT",
"version": "v2"
}
] | 2021-11-03 | [
[
"Kojo",
"Toru",
""
]
] | We analyze mesons in constant magnetic fields ($B$) within a non-relativistic constituent quark model. Our quark model contains a harmonic oscillator type confining potential, and we perturbatively treat short range correlations to account for the spin-flavor energy splittings. We study both neutral and charged mesons taking into account the internal quark dynamics. The neutral states are labelled by two-dimensional momenta for magnetic translations, while the charged states by two discrete indices related to angular momenta. For $B \ll \Lambda_{\rm QCD}^2$ ($\Lambda_{\rm QCD} \sim 200$ MeV: the QCD scale), the analyses proceed as in usual quark models, while special precautions are needed for strong fields, $B \sim \Lambda_{QCD}^2$, especially when we treat short range correlations such as the Fermi-Breit-Pauli interactions. We compute the energy spectra of mesons up to energies of $\sim 2.5$ GeV and use them to construct the meson resonance gas. Within the assumption that the constituent quark masses are insensitive to magnetic fields, the phase space enhancement for mesons significantly increases the entropy, assisting a transition from a hadron gas to a quark gluon plasma. We confront our results with the lattice data, finding reasonable agreement for the low-lying spectra and the entropy density at low temperature less than $\sim 100$ MeV, but our results at higher energy scale suffer from artifacts of our confining potential and non-relativistic treatments. |
hep-ph/9405382 | null | F. de Campos, J. W. F. Valle, A. Lopez-Fernandez and J.C.Rom\~ao | Updated Limits on Visibly and Invisibly Decaying Higgs Bosons from LEP | FTUV/94-28 IFIC/94-26, 6 pages + two figures (.ps files included) | null | null | null | hep-ph | null | Talk presented at the XXIX Rencontres de Moriond, Electroweak Interactions
and Unified Theories, March 12-19, 1994, Meribel
| [
{
"created": "Wed, 25 May 1994 16:29:45 GMT",
"version": "v1"
}
] | 2019-08-17 | [
[
"de Campos",
"F.",
""
],
[
"Valle",
"J. W. F.",
""
],
[
"Lopez-Fernandez",
"A.",
""
],
[
"Romão",
"J. C.",
""
]
] | Talk presented at the XXIX Rencontres de Moriond, Electroweak Interactions and Unified Theories, March 12-19, 1994, Meribel |
hep-ph/9406292 | Xing Zhi-Zhong | Dan-di WU and Zhi-zhong XING | On the Unitarity Triangles of the CKM Matrix | 9 Latex pages; LMU-07/94 and PVAMU-HEP-94-5 (A few minor changes are
made, accepted for publication in Phys. Lett. B) | Phys.Lett.B341:386-390,1995 | 10.1016/0370-2693(94)01312-Z | null | hep-ph | null | The unitarity triangles of the $3\times 3$ Cabibbo-Kobayashi-Maskawa (CKM)
matrix are studied in a systematic way. We show that the phases of the nine CKM
rephasing invariants are indeed the outer angles of the six unitarity triangles
and measurable in the $CP$-violating decay modes of $B_{d}$ and $B_{s}$ mesons.
An economical notation system is introduced for describing properties of the
unitarity triangles. To test unitarity of the CKM matrix we present some
approximate but useful relations among the sides and angles of the unitarity
triangles, which can be confronted with the accessible experiments of quark
mixing and $CP$ violation.
| [
{
"created": "Sun, 12 Jun 1994 08:50:49 GMT",
"version": "v1"
},
{
"created": "Tue, 11 Oct 1994 19:03:23 GMT",
"version": "v2"
}
] | 2010-11-01 | [
[
"WU",
"Dan-di",
""
],
[
"XING",
"Zhi-zhong",
""
]
] | The unitarity triangles of the $3\times 3$ Cabibbo-Kobayashi-Maskawa (CKM) matrix are studied in a systematic way. We show that the phases of the nine CKM rephasing invariants are indeed the outer angles of the six unitarity triangles and measurable in the $CP$-violating decay modes of $B_{d}$ and $B_{s}$ mesons. An economical notation system is introduced for describing properties of the unitarity triangles. To test unitarity of the CKM matrix we present some approximate but useful relations among the sides and angles of the unitarity triangles, which can be confronted with the accessible experiments of quark mixing and $CP$ violation. |
1704.02078 | Arindam Das | Arindam Das, Takaaki Nomura, Hiroshi Okada, Sourov Roy | Generation of radiative neutrino mass in the linear seesaw framework,
charged lepton flavor violation and dark matter | 20 pages, 4 figures, typos corrected, references added, collider
prospects added, version accepted for publication in Physical Review D | Phys. Rev. D 96, 075001 (2017) | 10.1103/PhysRevD.96.075001 | KIAS-P17018 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate a model with local U(1)$_{B-L}$ and discrete $Z_2$ symmetries
where two types of weak isospin singlet neutrinos, vector-like charged lepton
and exotic scalar fields are introduced. The linear seesaw mechanism is induced
at one-loop level through Yukawa interactions associated with the standard
model leptons and exotic fields. We also discuss lepton flavor violation and
muon anomalous dipole magnetic moment induced by the new Yukawa interaction. In
addition, our model has dark matter candidate which is the lightest $Z_2$ odd
neutral particle. We calculate the relic density and constraints from direct
detection.
| [
{
"created": "Fri, 7 Apr 2017 03:20:00 GMT",
"version": "v1"
},
{
"created": "Fri, 15 Sep 2017 04:22:48 GMT",
"version": "v2"
}
] | 2018-04-04 | [
[
"Das",
"Arindam",
""
],
[
"Nomura",
"Takaaki",
""
],
[
"Okada",
"Hiroshi",
""
],
[
"Roy",
"Sourov",
""
]
] | We investigate a model with local U(1)$_{B-L}$ and discrete $Z_2$ symmetries where two types of weak isospin singlet neutrinos, vector-like charged lepton and exotic scalar fields are introduced. The linear seesaw mechanism is induced at one-loop level through Yukawa interactions associated with the standard model leptons and exotic fields. We also discuss lepton flavor violation and muon anomalous dipole magnetic moment induced by the new Yukawa interaction. In addition, our model has dark matter candidate which is the lightest $Z_2$ odd neutral particle. We calculate the relic density and constraints from direct detection. |
hep-ph/9804245 | Takasugi | Robert Kinyua and Eiichi Takasugi | $e^- e^-$ Collisions Mediated by Composite Neutrinos | 9pages | Prog.Theor.Phys. 100 (1998) 607-614 | 10.1143/PTP.100.607 | null | hep-ph | null | The lepton number violating process, $e^- e^- \to W^- W^-$ has been widely
discussed in the Majorana neutrino exchange mechanism. Here, we discuss this
process in a composite neutrino model where excited Majorana neutrinos are
exchanged. We found several qualitatively different features from the neutrino
exchange case: (1) The longitudinally polarized $W$'s are not produced, (2) the
neutrinoless double beta decay does not constrain much and a much larger cross
section is expected, and (3) CP violating phases may be explored because all
excited neutrinos are heavy so that large mixings among them are expected.
| [
{
"created": "Tue, 7 Apr 1998 03:28:50 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Kinyua",
"Robert",
""
],
[
"Takasugi",
"Eiichi",
""
]
] | The lepton number violating process, $e^- e^- \to W^- W^-$ has been widely discussed in the Majorana neutrino exchange mechanism. Here, we discuss this process in a composite neutrino model where excited Majorana neutrinos are exchanged. We found several qualitatively different features from the neutrino exchange case: (1) The longitudinally polarized $W$'s are not produced, (2) the neutrinoless double beta decay does not constrain much and a much larger cross section is expected, and (3) CP violating phases may be explored because all excited neutrinos are heavy so that large mixings among them are expected. |
0707.1440 | Wolfgang Lucha | Wolfgang Lucha, F. Schoberl | Stability of Salpeter Solutions | 6 pages, 2 figures, to appear in the Proceedings of "QCD @ Work
2007", International Workshop on Quantum ChromoDynamics - Theory and
Experiment, Martina Franca, Italy, 16 - 20 June 2007 | AIPConf.Proc.964:318-323,2007 | 10.1063/1.2823870 | HEPHY-PUB 844/07 | hep-ph | null | In the framework of instantaneous approximations to the Bethe-Salpeter
formalism for the description of bound states within quantum field theories,
depending on the Lorentz structure of the Bethe-Salpeter interaction kernel the
solutions of the full Salpeter equation with some confining interaction may
exhibit certain instabilities, which are possibly related to the Klein paradox
and signal the decay of states assumed to be bound by the confining
interactions. They are observed in numerical (variational) studies of the
Salpeter equation. The presumably simplest scenario allowing for the fully
analytic investigation of this problem is set by the reduced Salpeter equation
with harmonic-oscillator interaction. In this case, Salpeter's integral
equation simplifies to either an algebraic relation or a second-order
homogeneous linear ordinary differential equation, immediately accessible to
standard techniques. There one may hope to be able to decide unambiguously
whether this setting poses a well-defined eigenvalue problem the solutions of
which correspond to stable bound states associated to real energy eigenvalues
bounded from below. By analytical spectral analysis the bound-state solutions
of this "harmonic-oscillator reduced Salpeter equation" can be shown to be free
of such instabilities.
| [
{
"created": "Tue, 10 Jul 2007 13:10:30 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Lucha",
"Wolfgang",
""
],
[
"Schoberl",
"F.",
""
]
] | In the framework of instantaneous approximations to the Bethe-Salpeter formalism for the description of bound states within quantum field theories, depending on the Lorentz structure of the Bethe-Salpeter interaction kernel the solutions of the full Salpeter equation with some confining interaction may exhibit certain instabilities, which are possibly related to the Klein paradox and signal the decay of states assumed to be bound by the confining interactions. They are observed in numerical (variational) studies of the Salpeter equation. The presumably simplest scenario allowing for the fully analytic investigation of this problem is set by the reduced Salpeter equation with harmonic-oscillator interaction. In this case, Salpeter's integral equation simplifies to either an algebraic relation or a second-order homogeneous linear ordinary differential equation, immediately accessible to standard techniques. There one may hope to be able to decide unambiguously whether this setting poses a well-defined eigenvalue problem the solutions of which correspond to stable bound states associated to real energy eigenvalues bounded from below. By analytical spectral analysis the bound-state solutions of this "harmonic-oscillator reduced Salpeter equation" can be shown to be free of such instabilities. |
hep-ph/9710464 | Stephen Wong | P. Kroll and S.M.H. Wong | Colour Octet Contribution in Exclusive Charmonium Decay into
Baryon-Antibaryon | 4 pages, talk presented at the IVth International Workshop on Progess
in Heavy Quark Physics, Rostock, Germany, Sept 97 | Proc. Prog. in Heavy Quarks Physics p.185 | null | WU-B 97-27 | hep-ph | null | It is argued that colour octet contribution in exclusive charmonium decays is
very important even though the same infrared divergence found in P-wave colour
singlet inclusive decay is absent. This comes about because of the suppression
at the level of the wavefunction of P-wave quarkonia. Using the modified hard
scattering approach of Brodsky, Lepage, Botts, Li and Sterman, we use
charmonium decay into baryon-antibaryon pair as an example and show that the
colour singlet contribution alone is clearly insufficient to explain the
experimental decay widths.
| [
{
"created": "Fri, 24 Oct 1997 18:10:23 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Kroll",
"P.",
""
],
[
"Wong",
"S. M. H.",
""
]
] | It is argued that colour octet contribution in exclusive charmonium decays is very important even though the same infrared divergence found in P-wave colour singlet inclusive decay is absent. This comes about because of the suppression at the level of the wavefunction of P-wave quarkonia. Using the modified hard scattering approach of Brodsky, Lepage, Botts, Li and Sterman, we use charmonium decay into baryon-antibaryon pair as an example and show that the colour singlet contribution alone is clearly insufficient to explain the experimental decay widths. |
1609.04575 | Masahiro Ishii | Masahiro Ishii, Hiroaki Kouno, Masanobu Yahiro | Model prediction for temperature dependence of meson pole masses from
lattice QCD results on meson screening masses | 13 pages, 14 figures | Phys. Rev. D 95, 114022 (2017) | 10.1103/PhysRevD.95.114022 | null | hep-ph hep-ex hep-lat nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose a practical effective model by introducing temperature ($T$)
dependence to the coupling strengths of four-quark and six-quark
Kobayashi-Maskawa-'t Hooft interactions in the 2+1 flavor Polyakov-loop
extended Nambu-Jona-Lasinio model. The $T$ dependence is determined from LQCD
data on the renormalized chiral condensate around the pseudocritical
temperature $T_c^{\chi}$ of chiral crossover and the screening-mass difference
between $\pi$ and $a_0$ mesons in $T > 1.1T_c^\chi$ where only the $U(1)_{\rm
A}$-symmetry breaking survives. The model well reproduces LQCD data on
screening masses $M_{\xi}^{\rm scr}(T)$ for both scalar and pseudoscalar
mesons, particularly in $T \ge T_c^{\chi}$. Using this effective model, we
predict meson pole masses $M_{\xi}^{\rm pole}(T)$ for scalar and pseudoscalar
mesons. For $\eta'$ meson, the prediction is consistent with the experimental
value at finite $T$ measured in heavy-ion collisions. We point out that the
relation $M_{\xi}^{\rm scr}(T)-M_{\xi}^{\rm pole}(T) \approx M_{\xi'}^{\rm
scr}(T)-M_{\xi'}^{\rm pole}(T)$ is pretty good when $\xi$ and $\xi'$ are scalar
mesons, and show that the relation $M_{\xi}^{\rm scr}(T)/M_{\xi'}^{\rm scr}(T)
\approx M_{\xi}^{\rm pole}(T)/M_{\xi'}^{\rm pole}(T)$ is well satisfied within
20% error when $\xi$ and $\xi'$ are pseudoscalar mesons and also when $\xi$ and
$\xi'$ are scalar mesons.
| [
{
"created": "Thu, 15 Sep 2016 11:34:58 GMT",
"version": "v1"
}
] | 2017-07-05 | [
[
"Ishii",
"Masahiro",
""
],
[
"Kouno",
"Hiroaki",
""
],
[
"Yahiro",
"Masanobu",
""
]
] | We propose a practical effective model by introducing temperature ($T$) dependence to the coupling strengths of four-quark and six-quark Kobayashi-Maskawa-'t Hooft interactions in the 2+1 flavor Polyakov-loop extended Nambu-Jona-Lasinio model. The $T$ dependence is determined from LQCD data on the renormalized chiral condensate around the pseudocritical temperature $T_c^{\chi}$ of chiral crossover and the screening-mass difference between $\pi$ and $a_0$ mesons in $T > 1.1T_c^\chi$ where only the $U(1)_{\rm A}$-symmetry breaking survives. The model well reproduces LQCD data on screening masses $M_{\xi}^{\rm scr}(T)$ for both scalar and pseudoscalar mesons, particularly in $T \ge T_c^{\chi}$. Using this effective model, we predict meson pole masses $M_{\xi}^{\rm pole}(T)$ for scalar and pseudoscalar mesons. For $\eta'$ meson, the prediction is consistent with the experimental value at finite $T$ measured in heavy-ion collisions. We point out that the relation $M_{\xi}^{\rm scr}(T)-M_{\xi}^{\rm pole}(T) \approx M_{\xi'}^{\rm scr}(T)-M_{\xi'}^{\rm pole}(T)$ is pretty good when $\xi$ and $\xi'$ are scalar mesons, and show that the relation $M_{\xi}^{\rm scr}(T)/M_{\xi'}^{\rm scr}(T) \approx M_{\xi}^{\rm pole}(T)/M_{\xi'}^{\rm pole}(T)$ is well satisfied within 20% error when $\xi$ and $\xi'$ are pseudoscalar mesons and also when $\xi$ and $\xi'$ are scalar mesons. |
1302.5316 | Alexander Smirnov D. | I. V. Frolov, M. V. Martynov, A. D. Smirnov | The chiral color symmetry of quarks and $G'$-boson contributions to
charge asymmetry in $t \bar t$-production at the LHC and Tevatron | 11 pages, 3 figures, accepted for publication in Modern Physics
Letters A; v2: corrected misprint, added references | Mod. Phys. Lett. A, Vol. 28, No. 10 (2013) 1350035 | 10.1142/S0217732313500351 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The contributions of $G'$-boson predicted by the chiral color symmetry of
quarks to the charge asymmetry $A_C(p p \to t\bar{t})$ in $t \bar{t}$
production at the LHC and to the forward-backward asymmetry $A_{\rm
FB}(p\bar{p} \to t\bar{t})$ in $t\bar{t}$ production at the Tevatron are
calculated and analysed in dependence on two free parameters of the model, the
$G'$ mass $m_{G'}$ and mixing angle $\theta_G$. The $m_{G'} - \theta_G$ regions
of $1 \sigma$ consistency with the CMS data on the cross section $\sigma(pp \to
t\bar{t})$ and on the charge asymmetry $A_C(p p \to t\bar{t})$ are found and
compared with those resulted from the CDF data on the cross section
$\sigma(p\bar{p} \to t\bar{t})$ and on the forward-backward asymmetry $A_{\rm
FB}(p\bar{p} \to t\bar{t})$ of $t \bar{t}$ production at the Tevatron with
account of the current SM predictions for $A_{\rm FB}(p\bar{p} \to t\bar{t})$.
| [
{
"created": "Thu, 21 Feb 2013 16:03:00 GMT",
"version": "v1"
},
{
"created": "Mon, 4 Mar 2013 15:53:27 GMT",
"version": "v2"
}
] | 2013-04-25 | [
[
"Frolov",
"I. V.",
""
],
[
"Martynov",
"M. V.",
""
],
[
"Smirnov",
"A. D.",
""
]
] | The contributions of $G'$-boson predicted by the chiral color symmetry of quarks to the charge asymmetry $A_C(p p \to t\bar{t})$ in $t \bar{t}$ production at the LHC and to the forward-backward asymmetry $A_{\rm FB}(p\bar{p} \to t\bar{t})$ in $t\bar{t}$ production at the Tevatron are calculated and analysed in dependence on two free parameters of the model, the $G'$ mass $m_{G'}$ and mixing angle $\theta_G$. The $m_{G'} - \theta_G$ regions of $1 \sigma$ consistency with the CMS data on the cross section $\sigma(pp \to t\bar{t})$ and on the charge asymmetry $A_C(p p \to t\bar{t})$ are found and compared with those resulted from the CDF data on the cross section $\sigma(p\bar{p} \to t\bar{t})$ and on the forward-backward asymmetry $A_{\rm FB}(p\bar{p} \to t\bar{t})$ of $t \bar{t}$ production at the Tevatron with account of the current SM predictions for $A_{\rm FB}(p\bar{p} \to t\bar{t})$. |
2112.06847 | Manoranjan Dutta | Debasish Borah (1), Manoranjan Dutta (2), Satyabrata Mahapatra (2),
Narendra Sahu (2) ((1) Indian Institute of Technology Guwahati, (2) Indian
Institute of Technology Hyderabad) | Singlet-Doublet Self-interacting Dark Matter and Radiative Neutrino Mass | 17 pages, 16 captioned figures, Version accepted for publication in
PRD | null | 10.1103/PhysRevD.105.075019 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | Self-interacting dark matter (SIDM) with a light mediator is a promising
scenario to alleviate the small-scale problems of the cold dark matter paradigm
while being consistent with the latter at large scales, as suggested by
astrophysical observations. This, however, leads to an under-abundant SIDM
relic due to large annihilation rates into mediator particles, often requiring
an extension of the simplest thermal or non-thermal relic generation mechanism.
In this work, we consider a singlet-doublet fermion dark matter scenario where
the singlet fermion with a light scalar mediator gives rise to the
velocity-dependent dark matter self-interaction through a Yukawa type
attractive potential. The doublet fermion, by virtue of its tiny mixing with
the singlet, can be long-lived and can provide a non-thermal contribution to
the singlet relic at late epochs, filling the deficit in the thermal relic of
singlet SIDM. The light scalar mediator, due to its mixing with the standard
model Higgs, paves the path for detecting such SIDM at terrestrial laboratories
leading to constraints on model parameters from CRESST-III and XENON1T
experiments. Enlarging the dark sector particles by two more singlet fermions
and one scalar doublet, all odd under an unbroken $\mathcal{Z}_2$ symmetry can
also explain non-zero neutrino mass in scotogenic fashion.
| [
{
"created": "Mon, 13 Dec 2021 18:01:24 GMT",
"version": "v1"
},
{
"created": "Sat, 23 Apr 2022 03:07:03 GMT",
"version": "v2"
}
] | 2022-05-04 | [
[
"Borah",
"Debasish",
""
],
[
"Dutta",
"Manoranjan",
""
],
[
"Mahapatra",
"Satyabrata",
""
],
[
"Sahu",
"Narendra",
""
]
] | Self-interacting dark matter (SIDM) with a light mediator is a promising scenario to alleviate the small-scale problems of the cold dark matter paradigm while being consistent with the latter at large scales, as suggested by astrophysical observations. This, however, leads to an under-abundant SIDM relic due to large annihilation rates into mediator particles, often requiring an extension of the simplest thermal or non-thermal relic generation mechanism. In this work, we consider a singlet-doublet fermion dark matter scenario where the singlet fermion with a light scalar mediator gives rise to the velocity-dependent dark matter self-interaction through a Yukawa type attractive potential. The doublet fermion, by virtue of its tiny mixing with the singlet, can be long-lived and can provide a non-thermal contribution to the singlet relic at late epochs, filling the deficit in the thermal relic of singlet SIDM. The light scalar mediator, due to its mixing with the standard model Higgs, paves the path for detecting such SIDM at terrestrial laboratories leading to constraints on model parameters from CRESST-III and XENON1T experiments. Enlarging the dark sector particles by two more singlet fermions and one scalar doublet, all odd under an unbroken $\mathcal{Z}_2$ symmetry can also explain non-zero neutrino mass in scotogenic fashion. |
1310.6937 | Hans-Werner Hammer | M. Jansen, H.-W. Hammer, Yu Jia | Light quark mass dependence of the X(3872) in XEFT | 20 pages, 8 figures, REVTeX | Phys. Rev. D 89, 014033 (2014) | 10.1103/PhysRevD.89.014033 | null | hep-ph hep-lat | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The quark mass dependence of hadrons is an important input for lattice
calculations. We investigate the light quark mass dependence of the binding
energy of the X(3872) and the Dbar0-D*0 scattering length in the C=+1 channel
to next-to-leading order in XEFT where pion interactions are perturbative. At
this order, the quark mass dependence is determined by a quark mass-dependent
contact interaction in addition to the one-pion exchange. Using naturalness
arguments to constrain unknown parameters, we find a moderate sensitivity of
the binding energy for quark masses up to twice the physical value while the
scattering length is more sensitive. The occurrence of infrared divergences due
to on-shell pions in XEFT and their treatment is discussed in detail.
| [
{
"created": "Fri, 25 Oct 2013 14:42:08 GMT",
"version": "v1"
}
] | 2014-02-05 | [
[
"Jansen",
"M.",
""
],
[
"Hammer",
"H. -W.",
""
],
[
"Jia",
"Yu",
""
]
] | The quark mass dependence of hadrons is an important input for lattice calculations. We investigate the light quark mass dependence of the binding energy of the X(3872) and the Dbar0-D*0 scattering length in the C=+1 channel to next-to-leading order in XEFT where pion interactions are perturbative. At this order, the quark mass dependence is determined by a quark mass-dependent contact interaction in addition to the one-pion exchange. Using naturalness arguments to constrain unknown parameters, we find a moderate sensitivity of the binding energy for quark masses up to twice the physical value while the scattering length is more sensitive. The occurrence of infrared divergences due to on-shell pions in XEFT and their treatment is discussed in detail. |
hep-ph/0612061 | Michael R. Pennington | R. Williams, C. S. Fischer and M. R. Pennington | ${\bar {q}}q$ condensate for light quarks beyond the chiral limit | 13 pages, 8 figures | Phys.Lett.B645:167-172,2007 | 10.1016/j.physletb.2006.12.055 | DCPT/06/154; IPPP/06/77 | hep-ph | null | We determine the ${\bar{q}}q$ condensate for quark masses from zero up to
that of the strange quark within a phenomenologically successful modelling of
continuum QCD by solving the quark Schwinger-Dyson equation. The existence of
multiple solutions to this equation is the key to an accurate and reliable
extraction of this condensate using the operator product expansion. We explain
why alternative definitions fail to give the physical condensate.
| [
{
"created": "Wed, 6 Dec 2006 09:52:47 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Williams",
"R.",
""
],
[
"Fischer",
"C. S.",
""
],
[
"Pennington",
"M. R.",
""
]
] | We determine the ${\bar{q}}q$ condensate for quark masses from zero up to that of the strange quark within a phenomenologically successful modelling of continuum QCD by solving the quark Schwinger-Dyson equation. The existence of multiple solutions to this equation is the key to an accurate and reliable extraction of this condensate using the operator product expansion. We explain why alternative definitions fail to give the physical condensate. |
hep-ph/9804429 | Shinta Kasuya | S. Kasuya and M. Kawasaki | Topological Defects Formation after Inflation on Lattice Simulation | 7 pages, RevTex, 10 postscript figures included; version to be
published in Phys. Rev. D | Phys.Rev. D58 (1998) 083516 | 10.1103/PhysRevD.58.083516 | null | hep-ph astro-ph | null | We consider the formation of topological defects after inflation. In order to
take into account the effects of the rescattering of fluctuations, we integrate
the classical equation that describes the evolution of a complex scalar field
on the two-dimensional lattice with a slab symmetry. The growth of fluctuations
during preheating is found not to be enough for defect formation, and rather a
long stage of the rescattering of fluctuations after preheating is necessary.
We conclude that the topological defects are not formed if the breaking scale
\eta is lager than \sim (2 - 3)\times 10^{16} GeV.
| [
{
"created": "Tue, 28 Apr 1998 05:08:43 GMT",
"version": "v1"
},
{
"created": "Thu, 23 Jul 1998 08:03:55 GMT",
"version": "v2"
},
{
"created": "Thu, 10 Sep 1998 05:49:49 GMT",
"version": "v3"
}
] | 2009-10-31 | [
[
"Kasuya",
"S.",
""
],
[
"Kawasaki",
"M.",
""
]
] | We consider the formation of topological defects after inflation. In order to take into account the effects of the rescattering of fluctuations, we integrate the classical equation that describes the evolution of a complex scalar field on the two-dimensional lattice with a slab symmetry. The growth of fluctuations during preheating is found not to be enough for defect formation, and rather a long stage of the rescattering of fluctuations after preheating is necessary. We conclude that the topological defects are not formed if the breaking scale \eta is lager than \sim (2 - 3)\times 10^{16} GeV. |
hep-ph/0412417 | Xing Gang Wu | Tao Huang and Xing-Gang Wu | Consistent Analysis of the $B\to\pi$ Transition Form Factor in the Whole
Physical Region | 18pages, 6 figures | Phys.Rev. D71 (2005) 034018 | 10.1103/PhysRevD.71.034018 | null | hep-ph | null | In the paper, we show that the $B\to\pi$ transition form factor can be
calculated by using the different approach in the different $q^2$ regions and
they are consistent with each other in the whole physical region. For the
$B\to\pi$ transition form factor in the large recoil regions, one can apply the
PQCD approach, where the transverse momentum dependence for both the hard
scattering part and the non-perturbative wavefunction, the Sudakov effects and
the threshold effects are included to regulate the endpoint singularity and to
derive a more reliable PQCD result. Pionic twist-3 contributions are carefully
studied with a better endpoint behavior wavefunction for $\Psi_p$ and we find
that its contribution is less than the leading twist contribution. Both the two
wavefunctions $\Psi_B$ and $\bar\Psi_B$ of the B meson can give sizable
contributions to the $B\to\pi$ transition form factor and should be kept for a
better understanding of the B decays. The present obtained PQCD results can
match with both the QCD light-cone sum rule results and the extrapolated
lattice QCD results in the large recoil regions.
| [
{
"created": "Thu, 30 Dec 2004 02:29:59 GMT",
"version": "v1"
},
{
"created": "Mon, 31 Jan 2005 02:33:18 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Huang",
"Tao",
""
],
[
"Wu",
"Xing-Gang",
""
]
] | In the paper, we show that the $B\to\pi$ transition form factor can be calculated by using the different approach in the different $q^2$ regions and they are consistent with each other in the whole physical region. For the $B\to\pi$ transition form factor in the large recoil regions, one can apply the PQCD approach, where the transverse momentum dependence for both the hard scattering part and the non-perturbative wavefunction, the Sudakov effects and the threshold effects are included to regulate the endpoint singularity and to derive a more reliable PQCD result. Pionic twist-3 contributions are carefully studied with a better endpoint behavior wavefunction for $\Psi_p$ and we find that its contribution is less than the leading twist contribution. Both the two wavefunctions $\Psi_B$ and $\bar\Psi_B$ of the B meson can give sizable contributions to the $B\to\pi$ transition form factor and should be kept for a better understanding of the B decays. The present obtained PQCD results can match with both the QCD light-cone sum rule results and the extrapolated lattice QCD results in the large recoil regions. |
hep-ph/0311185 | Rohini M. Godbole | Rohini M. Godbole | CP property of the Higgs at the gamma gamma colliders using $t \bar t$
production | 16 pages, 10 figures, LaTeX. Talk presented at the 8th Accelerator
and Particle Physics Institute, APPI2003, Feb.25-28,2003, Appi, Japan | KEK Proceedings 2003-6, pp. 126-141 | null | IISc-CTS/8/03 | hep-ph | null | We present results of an investigation to study CP violation in the Higgs
sector in $t\bar t$ production at a $\gamma\gamma$-collider, via the process $
\gamgam \ra \phi \ra t \bar t$ where the $\phi$ is a scalar with indeterminate
CP parity. The study is performed in a model independent way parametrising the
CP violating couplings in terms of six form factors $\{\Re(S_{\gamma}),
\Im(S_{\gamma}), \Re(P_{\gamma}), \Im(P_{\gamma}), S_t, P_t\}$. The CP
violation is reflected in the polarisation asymmetry of the produced top quark.
We use the angular distribution of the decay lepton from $t/\bar t$ as a
diagnostic of this polarisation asymmetry and hence of the CP mixing, after
showing that the asymmetries in the angular distribution are indpendent of any
CP violation in the $tbW$ vertex. We construct combined asymmetries in the
initial state lepton (photon) polarization and the final state lepton charge
and study how well different combinations of these form factors can be probed
by measurements of these asymmetries, using circularly polarized photons. We
demonstrate the feasibility of the method to probe CP violation in the Higgs
sector at the level induced by loop effects in supersymmetric theories, using
realistic photon spectra expected for a TESLA like $e^+ e^-$ collider. We
investigate the sensitivity of our method for for different widths of the
scalar as well as for the more realistic backscattered laser photon spectrum
resulting from the inlcusion of the nonlinear effects.
| [
{
"created": "Fri, 14 Nov 2003 10:35:31 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Godbole",
"Rohini M.",
""
]
] | We present results of an investigation to study CP violation in the Higgs sector in $t\bar t$ production at a $\gamma\gamma$-collider, via the process $ \gamgam \ra \phi \ra t \bar t$ where the $\phi$ is a scalar with indeterminate CP parity. The study is performed in a model independent way parametrising the CP violating couplings in terms of six form factors $\{\Re(S_{\gamma}), \Im(S_{\gamma}), \Re(P_{\gamma}), \Im(P_{\gamma}), S_t, P_t\}$. The CP violation is reflected in the polarisation asymmetry of the produced top quark. We use the angular distribution of the decay lepton from $t/\bar t$ as a diagnostic of this polarisation asymmetry and hence of the CP mixing, after showing that the asymmetries in the angular distribution are indpendent of any CP violation in the $tbW$ vertex. We construct combined asymmetries in the initial state lepton (photon) polarization and the final state lepton charge and study how well different combinations of these form factors can be probed by measurements of these asymmetries, using circularly polarized photons. We demonstrate the feasibility of the method to probe CP violation in the Higgs sector at the level induced by loop effects in supersymmetric theories, using realistic photon spectra expected for a TESLA like $e^+ e^-$ collider. We investigate the sensitivity of our method for for different widths of the scalar as well as for the more realistic backscattered laser photon spectrum resulting from the inlcusion of the nonlinear effects. |
1904.06723 | Neda Darvishi | Neda Darvishi and Apostolos Pilaftsis | Quartic Coupling Unification in the Maximally Symmetric 2HDM | Minor typo corrected | Phys. Rev. D 99, 115014 (2019) | 10.1103/PhysRevD.99.115014 | MAN/HEP/2019/02 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider the Maximally Symmetric Two-Higgs Doublet Model (MS-2HDM) in
which the so-called Standard Model (SM) alignment can be naturally realised as
a consequence of an accidental SO(5) symmetry in the Higgs sector. This
symmetry is broken (i) explicitly by renormalization-group (RG) effects and
(ii) softly by the bilinear scalar mass term $m^2_{12}$. We find that in the
MS-2HDM all quartic couplings can unify at large RG scales $\mu_X \sim
10^{11}\,$-$\,10^{20}$ GeV. In particular, we show that quartic coupling
unification can take place in two different conformally invariant points, where
all quartic couplings vanish. We perform a vacuum stability analysis of the
model in order to ensure that the electro-weak vacuum is sufficiently
long-lived. The MS-2HDM is a minimal and very predictive extension of the SM
governed by only three additional parameters: the unification scale $\mu_X$,
the charged Higgs mass $M_{h^{\pm}}$ (or $m^2_{12}$) and $\tan\beta$, which
allow one to determine the entire Higgs sector of the model. In terms of these
input parameters, we present illustrative predictions of misalignment for the
SM-like Higgs-boson couplings to the $W^\pm$ and $Z$ bosons and, for the first
time, to the top and bottom quarks.
| [
{
"created": "Sun, 14 Apr 2019 16:49:50 GMT",
"version": "v1"
},
{
"created": "Tue, 7 May 2019 17:47:18 GMT",
"version": "v2"
},
{
"created": "Wed, 9 Oct 2019 16:54:08 GMT",
"version": "v3"
}
] | 2019-10-10 | [
[
"Darvishi",
"Neda",
""
],
[
"Pilaftsis",
"Apostolos",
""
]
] | We consider the Maximally Symmetric Two-Higgs Doublet Model (MS-2HDM) in which the so-called Standard Model (SM) alignment can be naturally realised as a consequence of an accidental SO(5) symmetry in the Higgs sector. This symmetry is broken (i) explicitly by renormalization-group (RG) effects and (ii) softly by the bilinear scalar mass term $m^2_{12}$. We find that in the MS-2HDM all quartic couplings can unify at large RG scales $\mu_X \sim 10^{11}\,$-$\,10^{20}$ GeV. In particular, we show that quartic coupling unification can take place in two different conformally invariant points, where all quartic couplings vanish. We perform a vacuum stability analysis of the model in order to ensure that the electro-weak vacuum is sufficiently long-lived. The MS-2HDM is a minimal and very predictive extension of the SM governed by only three additional parameters: the unification scale $\mu_X$, the charged Higgs mass $M_{h^{\pm}}$ (or $m^2_{12}$) and $\tan\beta$, which allow one to determine the entire Higgs sector of the model. In terms of these input parameters, we present illustrative predictions of misalignment for the SM-like Higgs-boson couplings to the $W^\pm$ and $Z$ bosons and, for the first time, to the top and bottom quarks. |
1711.00631 | Arvind Kumar | Rahul Chhabra and Arvind Kumar | In-medium properties of pseudoscalar $D_s$ and $B_s$ mesons | 34 pages annd 8 figures | Eur. Phys. J. C, 77 11 (2017) 726 | 10.1140/epjc/s10052-017-5277-8 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We calculate the shift in masses and decay constants of $D_s(1968)$ and
$B_s(5370)$ mesons in hot and dense asymmetric strange hadronic matter using
QCD sum rules and chiral SU(3) model. In-medium strange quark condensates
$\left\langle \bar{s}s\right\rangle_{\rho_B}$, and gluon condensates
$\left\langle \frac{\alpha_{s}}{\pi} {G^a}_{\mu\nu} {G^a}^{\mu\nu}
\right\rangle_{\rho_B}$ to be used in the QCD sum rules for pseudoscalar $D_s$
and $B_s$ mesons are calculated using chiral SU(3) model. As an application of
our present work, we calculate the in-medium decay widths of the excited
(c$\bar{s}$) states $D_s^*(2715)$ and $D_s^*(2860)$ decaying to
($D_s(1968)$,$\eta$) mesons. The medium effects in their decay widths are
incorporated through the mass modification of the $D_s(1968)$ and $\eta$
mesons. Results of the present investigation may be helpful to understand the
possible outcomes of the future experiments like CBM and PANDA under the FAIR
facility.
| [
{
"created": "Thu, 2 Nov 2017 06:45:26 GMT",
"version": "v1"
}
] | 2017-11-03 | [
[
"Chhabra",
"Rahul",
""
],
[
"Kumar",
"Arvind",
""
]
] | We calculate the shift in masses and decay constants of $D_s(1968)$ and $B_s(5370)$ mesons in hot and dense asymmetric strange hadronic matter using QCD sum rules and chiral SU(3) model. In-medium strange quark condensates $\left\langle \bar{s}s\right\rangle_{\rho_B}$, and gluon condensates $\left\langle \frac{\alpha_{s}}{\pi} {G^a}_{\mu\nu} {G^a}^{\mu\nu} \right\rangle_{\rho_B}$ to be used in the QCD sum rules for pseudoscalar $D_s$ and $B_s$ mesons are calculated using chiral SU(3) model. As an application of our present work, we calculate the in-medium decay widths of the excited (c$\bar{s}$) states $D_s^*(2715)$ and $D_s^*(2860)$ decaying to ($D_s(1968)$,$\eta$) mesons. The medium effects in their decay widths are incorporated through the mass modification of the $D_s(1968)$ and $\eta$ mesons. Results of the present investigation may be helpful to understand the possible outcomes of the future experiments like CBM and PANDA under the FAIR facility. |
1111.1633 | Jian Zhou Mr. | Jian-Hua Gao, Andreas Sch\"afer and Jian Zhou | Azimuthal asymmetry in SIDIS off nuclei as probe for $\hat q$ | 9 pages | null | 10.1103/PhysRevD.85.074027 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The energy loss parameter $\hat q$ is one of the fundamental transport
parameters of hadronic matter. Using the twist-4 collinear approach, we show
that the $\cos \phi$ azimuthal asymmetry in unpolarized semi-inclusive deeply
inelastic scattering (SIDIS) off a large nucleus at intermediate transverse
momentum is a sensitive observable for its determination. The effect is due to
the suppression of the azimuthal asymmetry by final-state multiple scattering.
| [
{
"created": "Mon, 7 Nov 2011 16:29:48 GMT",
"version": "v1"
}
] | 2013-05-30 | [
[
"Gao",
"Jian-Hua",
""
],
[
"Schäfer",
"Andreas",
""
],
[
"Zhou",
"Jian",
""
]
] | The energy loss parameter $\hat q$ is one of the fundamental transport parameters of hadronic matter. Using the twist-4 collinear approach, we show that the $\cos \phi$ azimuthal asymmetry in unpolarized semi-inclusive deeply inelastic scattering (SIDIS) off a large nucleus at intermediate transverse momentum is a sensitive observable for its determination. The effect is due to the suppression of the azimuthal asymmetry by final-state multiple scattering. |
1405.3506 | Daniele Binosi | A. C. Aguilar, D. Binosi, D. Iba\~nez, J. Papavassiliou | A new method for determining the quark-gluon vertex | 50 pages, 19 figures; expanded version matching the published one | Phys. Rev. D 90, 065027 (2014) | 10.1103/PhysRevD.90.065027 | null | hep-ph hep-lat hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a novel nonperturbative approach for calculating the form factors
of the quark-gluon vertex, in a general covariant gauge. The key ingredient of
this method is the exact all-order relation connecting the conventional
quark-gluon vertex with the corresponding vertex of the background field
method, which is Abelian-like. When this latter relation is combined with the
standard gauge technique, supplemented by a crucial set of transverse Ward
identities, it allows the approximate determination of the nonperturbative
behavior of all twelve form factors comprising the quark-gluon vertex, for
arbitrary values of the momenta. The actual implementation of this procedure is
carried out in the Landau gauge, in order to make contact with the results of
lattice simulations performed in this particular gauge. The most demanding
technical aspect involves the calculation of certain (fully-dressed) auxiliary
three-point functions, using lattice data as input for the gluon propagators
appearing in their diagrammatic expansion. The numerical evaluation of the
relevant form factors in three special kinematical configurations (soft gluon
and quark symmetric limit, zero quark momentum) is carried out in detail,
finding rather good agreement with the available lattice data. Most notably, a
concrete mechanism is proposed for explaining the puzzling divergence of one of
these form factors observed in lattice simulations.
| [
{
"created": "Wed, 14 May 2014 14:25:38 GMT",
"version": "v1"
},
{
"created": "Tue, 7 Apr 2015 14:51:18 GMT",
"version": "v2"
}
] | 2015-04-08 | [
[
"Aguilar",
"A. C.",
""
],
[
"Binosi",
"D.",
""
],
[
"Ibañez",
"D.",
""
],
[
"Papavassiliou",
"J.",
""
]
] | We present a novel nonperturbative approach for calculating the form factors of the quark-gluon vertex, in a general covariant gauge. The key ingredient of this method is the exact all-order relation connecting the conventional quark-gluon vertex with the corresponding vertex of the background field method, which is Abelian-like. When this latter relation is combined with the standard gauge technique, supplemented by a crucial set of transverse Ward identities, it allows the approximate determination of the nonperturbative behavior of all twelve form factors comprising the quark-gluon vertex, for arbitrary values of the momenta. The actual implementation of this procedure is carried out in the Landau gauge, in order to make contact with the results of lattice simulations performed in this particular gauge. The most demanding technical aspect involves the calculation of certain (fully-dressed) auxiliary three-point functions, using lattice data as input for the gluon propagators appearing in their diagrammatic expansion. The numerical evaluation of the relevant form factors in three special kinematical configurations (soft gluon and quark symmetric limit, zero quark momentum) is carried out in detail, finding rather good agreement with the available lattice data. Most notably, a concrete mechanism is proposed for explaining the puzzling divergence of one of these form factors observed in lattice simulations. |
hep-ph/0611098 | Andrea Lionetto | Alessandro Cesarini, Francesco Fucito, Andrea Lionetto | Deflected Anomaly Mediation and Neutralino Dark Matter | 23 pages, 6 figures, submitted to Phys. Rev. D | Phys.Rev.D75:025026,2007 | 10.1103/PhysRevD.75.025026 | ROM2F/2006/24 | hep-ph astro-ph | null | We study the phenomenology of the neutralino dark matter in the so called
deflected anomaly mediation scenario. This scheme is obtained from the minimal
anomaly mediated scenario by introducing a gauge mediated sector with $N_f$
messenger fields. Unlike the former scheme the latter has no tachyons. We find
that the neutralino is still the LSP in a wide region of the parameter space:
it is essentially a pure bino in the scenario with $N_f=1$ while it can also be
a pure higgsino for $N_f>1$. This is very different from the naive anomaly
mediated scenario which predicts a wino like neutralino. Moreover we do not
find any tachyonic scalars in this scheme. After computing the relic density
(considering all the possible coannihilations) we find that there are regions
in the parameter space with values compatible with the latest WMAP results with
no need to consider moduli fields that decay in the early universe.
| [
{
"created": "Wed, 8 Nov 2006 14:27:35 GMT",
"version": "v1"
},
{
"created": "Wed, 8 Nov 2006 22:50:20 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Cesarini",
"Alessandro",
""
],
[
"Fucito",
"Francesco",
""
],
[
"Lionetto",
"Andrea",
""
]
] | We study the phenomenology of the neutralino dark matter in the so called deflected anomaly mediation scenario. This scheme is obtained from the minimal anomaly mediated scenario by introducing a gauge mediated sector with $N_f$ messenger fields. Unlike the former scheme the latter has no tachyons. We find that the neutralino is still the LSP in a wide region of the parameter space: it is essentially a pure bino in the scenario with $N_f=1$ while it can also be a pure higgsino for $N_f>1$. This is very different from the naive anomaly mediated scenario which predicts a wino like neutralino. Moreover we do not find any tachyonic scalars in this scheme. After computing the relic density (considering all the possible coannihilations) we find that there are regions in the parameter space with values compatible with the latest WMAP results with no need to consider moduli fields that decay in the early universe. |
hep-ph/0406069 | Alexander Kalloniatis | Alex C. Kalloniatis (CSSM, Adelaide), Sergei N. Nedelko (JINR, Dubna),
Lorenz von Smekal (ITPIII, Erlangen) | Spectral density in resonance region and analytic confinement | 13 pages, RevTeX, 6 figures. Revised version with typographical
corrections and additional comments in conclusions | Phys.Rev. D70 (2004) 094037 | 10.1103/PhysRevD.70.094037 | ADP-04-14/T596 | hep-ph | null | We study the role of finite widths of resonances in a nonlocal version of the
Wick-Cutkosky model. The spectrum of bound states is known analytically in this
model and forms linear Regge tragectories. We compute the widths of resonances,
calculate the spectral density in an extension of the Breit-Wigner {\it ansatz}
and discuss a mechanism for the damping of unphysical exponential growth of
observables at high energy due to finite widths of resonances.
| [
{
"created": "Mon, 7 Jun 2004 03:22:00 GMT",
"version": "v1"
},
{
"created": "Fri, 15 Oct 2004 07:08:59 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Kalloniatis",
"Alex C.",
"",
"CSSM, Adelaide"
],
[
"Nedelko",
"Sergei N.",
"",
"JINR, Dubna"
],
[
"von Smekal",
"Lorenz",
"",
"ITPIII, Erlangen"
]
] | We study the role of finite widths of resonances in a nonlocal version of the Wick-Cutkosky model. The spectrum of bound states is known analytically in this model and forms linear Regge tragectories. We compute the widths of resonances, calculate the spectral density in an extension of the Breit-Wigner {\it ansatz} and discuss a mechanism for the damping of unphysical exponential growth of observables at high energy due to finite widths of resonances. |
1509.07906 | Cem Salih Un | Ilia Gogoladze, Qaisar Shafi and Cem Salih Un | Reconciling Muon g-2, 125 GeV Higgs and Dark Matter in Gauge Mediation
Models | null | Phys. Rev. D 92, 115014 (2015) | 10.1103/PhysRevD.92.115014 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a class of models in the framework of gauge mediation
supersymmetry breaking where the standard model is supplemented by additional
U(1) symmetry which acts only on the third generation fermions. The messenger
fields carry non-trivial U(1) charge and are vector-like particles under this
symmetry. This leads to additional contribution to the soft supersymmetry
breaking mass terms for the third generation squarks and sleptons. In this
framework we show that the muon g-2 anomaly, the observed 125 GeV Higgs boson
mass and the detected relic dark matter abundance (gravitino in our case) can
be simultaneously accommodated. The resolution of the muon g-2 anomaly, in
particular, yields the result that the first two generation squark masses, as
well the gluino mass, should be <~ 2.5 TeV, which will be tested at LHC14.
| [
{
"created": "Fri, 25 Sep 2015 21:54:27 GMT",
"version": "v1"
},
{
"created": "Tue, 2 Feb 2016 20:12:00 GMT",
"version": "v2"
}
] | 2016-02-03 | [
[
"Gogoladze",
"Ilia",
""
],
[
"Shafi",
"Qaisar",
""
],
[
"Un",
"Cem Salih",
""
]
] | We present a class of models in the framework of gauge mediation supersymmetry breaking where the standard model is supplemented by additional U(1) symmetry which acts only on the third generation fermions. The messenger fields carry non-trivial U(1) charge and are vector-like particles under this symmetry. This leads to additional contribution to the soft supersymmetry breaking mass terms for the third generation squarks and sleptons. In this framework we show that the muon g-2 anomaly, the observed 125 GeV Higgs boson mass and the detected relic dark matter abundance (gravitino in our case) can be simultaneously accommodated. The resolution of the muon g-2 anomaly, in particular, yields the result that the first two generation squark masses, as well the gluino mass, should be <~ 2.5 TeV, which will be tested at LHC14. |
1605.00991 | Ernest Ma | Ernest Ma, Nicholas Pollard, Oleg Popov, and Mohammadreza Zakeri | Gauge $B-L$ Model of Radiative Neutrino Mass with Multipartite Dark
Matter | 10 pages, 3 figures | null | 10.1142/S0217732316501637 | UCRHEP-T566 (May 2016) | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose an extension of the standard model of quarks and leptons to
include gauge $B-L$ symmetry with an exotic array of neutral fermion singlets
for anomaly cancellation. With the addition of suitable scalars also
transforming under $U(1)_{B-L}$, this becomes a model of radiative seesaw
neutrino mass with possible multipartite dark matter. If leptoquark fermions
are added, necessarily also transforming under $B-L$, the diphoton excess at
750 GeV, recently observed at the Large Hadron Collider, may also be explained.
| [
{
"created": "Tue, 3 May 2016 17:31:14 GMT",
"version": "v1"
}
] | 2016-09-21 | [
[
"Ma",
"Ernest",
""
],
[
"Pollard",
"Nicholas",
""
],
[
"Popov",
"Oleg",
""
],
[
"Zakeri",
"Mohammadreza",
""
]
] | We propose an extension of the standard model of quarks and leptons to include gauge $B-L$ symmetry with an exotic array of neutral fermion singlets for anomaly cancellation. With the addition of suitable scalars also transforming under $U(1)_{B-L}$, this becomes a model of radiative seesaw neutrino mass with possible multipartite dark matter. If leptoquark fermions are added, necessarily also transforming under $B-L$, the diphoton excess at 750 GeV, recently observed at the Large Hadron Collider, may also be explained. |
hep-ph/9404206 | Daniel Mustaki | D. Mustaki | Chiral Symmetry and the Constituent Quark Model: A Null-Plane Point of
View | 26 pages, Bowling Green State Univ. preprint | null | null | null | hep-ph | null | In order to clarify the connection between {\it current} and {\it
constituent} quarks (of u,d,s flavors), several authors have used the lightlike
chiral $SU(3)\otimes SU(3)$ algebra as a central concept. This literature is
reviewed here with the goal of offering an introduction to the subject within a
convenient, unified framework. It is shown that the null-plane Hamiltonian for
free massive fermions is chirally symmetric, provided only that the particles
have equal masses ($SU(3)$ limit). In the free quark model, hadrons can be
classified by a chiral $SU(3)\otimes SU(3)$ algebra, the generators of which
are current lightlike charges. Naturally, QCD interactions break chiral
symmetry, and the axial nonsinglet charges are not conserved. This remains true
in the 'chiral limit' (zero quark masses), signalling the spontaneous breakdown
of chiral symmetry. The actual generators of the $SU(3)\otimes SU(3)$
classification of physical hadrons are obtained from the current charges by
means of a unitary transformation. Under this transformation, quarks of the
same flavor and of opposite helicities mix to form a constituent quark. The
functional form of this unitary transformation can be strongly constrained on
the basis of symmetry arguments. This analysis is potentially rich in
phenomenological applications, and a few are presented here. The author offers
also some new theoretical results. No prior knowledge of light-cone formalism
on the part of the reader is assumed.
| [
{
"created": "Fri, 1 Apr 1994 23:27:33 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Mustaki",
"D.",
""
]
] | In order to clarify the connection between {\it current} and {\it constituent} quarks (of u,d,s flavors), several authors have used the lightlike chiral $SU(3)\otimes SU(3)$ algebra as a central concept. This literature is reviewed here with the goal of offering an introduction to the subject within a convenient, unified framework. It is shown that the null-plane Hamiltonian for free massive fermions is chirally symmetric, provided only that the particles have equal masses ($SU(3)$ limit). In the free quark model, hadrons can be classified by a chiral $SU(3)\otimes SU(3)$ algebra, the generators of which are current lightlike charges. Naturally, QCD interactions break chiral symmetry, and the axial nonsinglet charges are not conserved. This remains true in the 'chiral limit' (zero quark masses), signalling the spontaneous breakdown of chiral symmetry. The actual generators of the $SU(3)\otimes SU(3)$ classification of physical hadrons are obtained from the current charges by means of a unitary transformation. Under this transformation, quarks of the same flavor and of opposite helicities mix to form a constituent quark. The functional form of this unitary transformation can be strongly constrained on the basis of symmetry arguments. This analysis is potentially rich in phenomenological applications, and a few are presented here. The author offers also some new theoretical results. No prior knowledge of light-cone formalism on the part of the reader is assumed. |
0907.4125 | Vadim Guzey | V. Guzey (Jefferson Lab) | The Electron-Ion Collider | 4 pages, 1 figure. Presented at CIPANP 2009: 10th Conference on the
Intersections of Particle and Nuclear Physics, La Jolla, California, May
26-31, 2009 | AIP Conf.Proc.1182:803-806,2009 | 10.1063/1.3293930 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The future Electron-Ion Collider (EIC) is a proposed new facility to collide
high-energy electrons with beams of polarized protons/light nuclei and
unpolarized nuclei. We overview the goals of the project and key measurements
at the EIC. We also briefly comment on recent developments of the project.
| [
{
"created": "Thu, 23 Jul 2009 17:25:17 GMT",
"version": "v1"
}
] | 2010-01-15 | [
[
"Guzey",
"V.",
"",
"Jefferson Lab"
]
] | The future Electron-Ion Collider (EIC) is a proposed new facility to collide high-energy electrons with beams of polarized protons/light nuclei and unpolarized nuclei. We overview the goals of the project and key measurements at the EIC. We also briefly comment on recent developments of the project. |
hep-ph/0111460 | Ismd31 | Toru Sugitate | Correlations and Fluctuations at RHIC | 4 pages, 2 figures in eps, talk given at XXXI International Symposium
on Multiparticle Dynamics, Sept 1-7, 2001, Datong China. see
http://ismd31.ccnu.edu.cn/ | null | 10.1142/9789812778048_0057 | null | hep-ph | null | Particle correlations and fluctuations measured by RHIC experiments at
$\sqrt{s_{NN}}$=130 GeV were discussed. The source size parameters were similar
to those measured at the CERN-SPS, and no long duration time of particle
emission were observed. It was pointed out that the dependences of longitudinal
and transverse radius parameters on the pair momentum are explained with a
single $m_T$ scaling function observed at the SPS energy. Fluctuation studies
of mean $p_{T}$ of charged particles and of mean $E_{T}$ in an electromagnetic
calorimeter found no significant non-statistical fluctuations by PHENIX, but
some indication in charge independent $<p_T>$ by STAR.
| [
{
"created": "Fri, 30 Nov 2001 11:25:15 GMT",
"version": "v1"
},
{
"created": "Tue, 4 Dec 2001 08:06:56 GMT",
"version": "v2"
}
] | 2017-08-23 | [
[
"Sugitate",
"Toru",
""
]
] | Particle correlations and fluctuations measured by RHIC experiments at $\sqrt{s_{NN}}$=130 GeV were discussed. The source size parameters were similar to those measured at the CERN-SPS, and no long duration time of particle emission were observed. It was pointed out that the dependences of longitudinal and transverse radius parameters on the pair momentum are explained with a single $m_T$ scaling function observed at the SPS energy. Fluctuation studies of mean $p_{T}$ of charged particles and of mean $E_{T}$ in an electromagnetic calorimeter found no significant non-statistical fluctuations by PHENIX, but some indication in charge independent $<p_T>$ by STAR. |
hep-ph/0610206 | Robert Harlander | R.V. Harlander, D.R.T. Jones, P. Kant, L. Mihaila, M. Steinhauser | Four-loop beta function and mass anomalous dimension in Dimensional
Reduction | 15 pages, fixed typo in Eq. (18) | JHEP0612:024,2006 | 10.1088/1126-6708/2006/12/024 | SFB/CPP-06-48, TTP/06-27, WUB/06-05, LTH723, NSF-KITP-06-86 | hep-ph | null | Within the framework of QCD we compute renormalization constants for the
strong coupling and the quark masses to four-loop order. We apply the DR-bar
scheme and put special emphasis on the additional couplings which have to be
taken into account. This concerns the epsilon-scalar--quark Yukawa coupling as
well as the vertex containing four epsilon-scalars. For a supersymmetric Yang
Mills theory, we find, in contrast to a previous claim, that the evanescent
Yukawa coupling equals the strong coupling constant through three loops as
required by supersymmetry.
| [
{
"created": "Tue, 17 Oct 2006 09:12:45 GMT",
"version": "v1"
},
{
"created": "Fri, 22 Jun 2007 13:23:37 GMT",
"version": "v2"
}
] | 2009-11-11 | [
[
"Harlander",
"R. V.",
""
],
[
"Jones",
"D. R. T.",
""
],
[
"Kant",
"P.",
""
],
[
"Mihaila",
"L.",
""
],
[
"Steinhauser",
"M.",
""
]
] | Within the framework of QCD we compute renormalization constants for the strong coupling and the quark masses to four-loop order. We apply the DR-bar scheme and put special emphasis on the additional couplings which have to be taken into account. This concerns the epsilon-scalar--quark Yukawa coupling as well as the vertex containing four epsilon-scalars. For a supersymmetric Yang Mills theory, we find, in contrast to a previous claim, that the evanescent Yukawa coupling equals the strong coupling constant through three loops as required by supersymmetry. |
2408.01484 | Takuya Okawa | Saurav Das, P. S. Bhupal Dev, Takuya Okawa, Amarjit Soni | Old neutron stars as a new probe of relic neutrinos and sterile neutrino
dark matter | 13 pages, 3 figures | null | null | FERMILAB-PUB-24-0443-T | hep-ph astro-ph.HE astro-ph.SR nucl-th | http://creativecommons.org/licenses/by/4.0/ | We study the kinetic cooling (heating) of old neutron stars due to coherent
scattering with relic neutrinos (sterile neutrino dark matter) via Standard
Model neutral-current interactions. We take into account several important
physical effects, such as gravitational clustering, coherent enhancement,
neutron degeneracy and Pauli blocking. We find that the anomalous cooling of
nearby neutron stars due to relic neutrino scattering might actually be
observable by current and future telescopes operating in the optical to
near-infrared frequency band, such as the James Webb Space Telescope (JWST),
provided there is a large local relic overdensity that is still allowed.
Similarly, the anomalous heating of neutron stars due to coherent scattering
with keV-scale sterile neutrino dark matter, could also be observed by JWST or
future telescopes, which would probe hitherto unexplored parameter space in the
sterile neutrino mass-mixing plane.
| [
{
"created": "Fri, 2 Aug 2024 18:00:00 GMT",
"version": "v1"
}
] | 2024-08-06 | [
[
"Das",
"Saurav",
""
],
[
"Dev",
"P. S. Bhupal",
""
],
[
"Okawa",
"Takuya",
""
],
[
"Soni",
"Amarjit",
""
]
] | We study the kinetic cooling (heating) of old neutron stars due to coherent scattering with relic neutrinos (sterile neutrino dark matter) via Standard Model neutral-current interactions. We take into account several important physical effects, such as gravitational clustering, coherent enhancement, neutron degeneracy and Pauli blocking. We find that the anomalous cooling of nearby neutron stars due to relic neutrino scattering might actually be observable by current and future telescopes operating in the optical to near-infrared frequency band, such as the James Webb Space Telescope (JWST), provided there is a large local relic overdensity that is still allowed. Similarly, the anomalous heating of neutron stars due to coherent scattering with keV-scale sterile neutrino dark matter, could also be observed by JWST or future telescopes, which would probe hitherto unexplored parameter space in the sterile neutrino mass-mixing plane. |
hep-ph/0001280 | Hrvoje Stefancic | B. Guberina, B. Melic and H. Stefancic | Preasymptotic effects in beauty decays | 6 pages, talk given by B. Melic at The 3rd International Conference
on B Physics and CP Violation, Taipei, Taiwan, December 3-7, 1999, to appear
in the Proceedings, two figures added | null | 10.1142/9789812791870_0024 | IRB-TH-10/99 | hep-ph | null | Large preasymptotic effects in beauty decays have been found using
heavy-quark and SU(3) symmetry, as well as experimental data on charmed
hyperons. Contrary to rather uniform beauty-meson lifetimes, a much larger
spread of beauty-baryon lifetimes is predicted. However, it is highly unlikely
that, theoretically, the $ \tau(\Lambda_b)/\tau(B_d^0) $ ratio, which at
present deviates more than $1\sigma$ from the experimental result, can be
lowered below 0.9.
| [
{
"created": "Thu, 27 Jan 2000 15:57:21 GMT",
"version": "v1"
},
{
"created": "Tue, 1 Feb 2000 09:21:51 GMT",
"version": "v2"
}
] | 2016-11-23 | [
[
"Guberina",
"B.",
""
],
[
"Melic",
"B.",
""
],
[
"Stefancic",
"H.",
""
]
] | Large preasymptotic effects in beauty decays have been found using heavy-quark and SU(3) symmetry, as well as experimental data on charmed hyperons. Contrary to rather uniform beauty-meson lifetimes, a much larger spread of beauty-baryon lifetimes is predicted. However, it is highly unlikely that, theoretically, the $ \tau(\Lambda_b)/\tau(B_d^0) $ ratio, which at present deviates more than $1\sigma$ from the experimental result, can be lowered below 0.9. |
1703.01626 | Patrizia Azzi | P. Azzi, P. Azzurri, S. Biswas, F. Blekman, G. Corcella, S. De Curtis,
J. Erler, N. Foppiani, I. Helenius, S. Jadach, P. Janot, F. Jegerlehner, P.
Langacker, E. Locci, F. Margaroli, B. Mele, F. Piccinini, J. Reuter, M.
Steinhauser, R. Tenchini, M. Vos, C. Zhang | Physics Behind Precision | https://indico.cern.ch/event/469561/ | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This document provides a writeup of contributions to the FCC-ee mini-workshop
on "Physics behind precision" held at CERN, on 2-3 February 2016.
| [
{
"created": "Sun, 5 Mar 2017 17:04:13 GMT",
"version": "v1"
}
] | 2017-03-07 | [
[
"Azzi",
"P.",
""
],
[
"Azzurri",
"P.",
""
],
[
"Biswas",
"S.",
""
],
[
"Blekman",
"F.",
""
],
[
"Corcella",
"G.",
""
],
[
"De Curtis",
"S.",
""
],
[
"Erler",
"J.",
""
],
[
"Foppiani",
"N.",
""
],
[
"Helenius",
"I.",
""
],
[
"Jadach",
"S.",
""
],
[
"Janot",
"P.",
""
],
[
"Jegerlehner",
"F.",
""
],
[
"Langacker",
"P.",
""
],
[
"Locci",
"E.",
""
],
[
"Margaroli",
"F.",
""
],
[
"Mele",
"B.",
""
],
[
"Piccinini",
"F.",
""
],
[
"Reuter",
"J.",
""
],
[
"Steinhauser",
"M.",
""
],
[
"Tenchini",
"R.",
""
],
[
"Vos",
"M.",
""
],
[
"Zhang",
"C.",
""
]
] | This document provides a writeup of contributions to the FCC-ee mini-workshop on "Physics behind precision" held at CERN, on 2-3 February 2016. |
2203.11883 | Bojana Ilic (Blagojevic) | Bojana Ilic, Dusan Zigic, Marko Djordjevic and Magdalena Djordjevic | Utilizing high-$p_\perp$ theory and data to constrain the initial stages
of quark-gluon plasma | 12 pages, 5 figures | Int. J. Mod. Phys. E 30, no.11, 2141007 (2021) | 10.1142/S021830132141007X | null | hep-ph nucl-th | http://creativecommons.org/licenses/by/4.0/ | The scarce knowledge of the initial stages of quark-gluon plasma before the
thermalization is mostly inferred through the low-$p_\perp$ sector. We propose
a complementary approach in this report - the use of high-$p_\perp$ probes'
energy loss. We study the effects of four commonly assumed initial stages,
whose temperature profiles differ only before the thermalization, on
high-$p_\perp$ $R_{AA}$ and $v_2$ predictions. The predictions are based on our
Dynamical Radiative and Elastic ENergy-loss Approach (DREENA) framework. We
report insensitivity of $v_2$ to the initial stages, making it unable to
distinguish between different cases. $R_{AA}$ displays sensitivity to the
presumed initial stages, but current experimental precision does not allow
resolution between these cases. We further revise the commonly accepted
procedure of fitting the energy loss parameters, for each individual initial
stage, to the measured $R_{AA}$. We show that the sensitivity of $v_2$ to
various initial stages obtained through such procedure is mostly a consequence
of fitting procedure, which may obscure the physical interpretations. Overall,
the simultaneous study of high-$p_\perp$ observables, with unchanged energy
loss parametrization and restrained temperature profiles, is crucial for future
constraints on initial stages.
| [
{
"created": "Tue, 22 Mar 2022 16:58:31 GMT",
"version": "v1"
}
] | 2022-03-23 | [
[
"Ilic",
"Bojana",
""
],
[
"Zigic",
"Dusan",
""
],
[
"Djordjevic",
"Marko",
""
],
[
"Djordjevic",
"Magdalena",
""
]
] | The scarce knowledge of the initial stages of quark-gluon plasma before the thermalization is mostly inferred through the low-$p_\perp$ sector. We propose a complementary approach in this report - the use of high-$p_\perp$ probes' energy loss. We study the effects of four commonly assumed initial stages, whose temperature profiles differ only before the thermalization, on high-$p_\perp$ $R_{AA}$ and $v_2$ predictions. The predictions are based on our Dynamical Radiative and Elastic ENergy-loss Approach (DREENA) framework. We report insensitivity of $v_2$ to the initial stages, making it unable to distinguish between different cases. $R_{AA}$ displays sensitivity to the presumed initial stages, but current experimental precision does not allow resolution between these cases. We further revise the commonly accepted procedure of fitting the energy loss parameters, for each individual initial stage, to the measured $R_{AA}$. We show that the sensitivity of $v_2$ to various initial stages obtained through such procedure is mostly a consequence of fitting procedure, which may obscure the physical interpretations. Overall, the simultaneous study of high-$p_\perp$ observables, with unchanged energy loss parametrization and restrained temperature profiles, is crucial for future constraints on initial stages. |
1602.02639 | Antonino Di Piazza | A. Angioi, F. Mackenroth, and A. Di Piazza | Nonlinear single Compton scattering of an electron wave-packet | 24 pages, 12 figures | Phys. Rev. A vol. 93, 052102 (2016) | 10.1103/PhysRevA.93.052102 | null | hep-ph physics.plasm-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Nonlinear single Compton scattering has been thoroughly investigated in the
literature under the assumption that initially the electron has a definite
momentum. Here, we study a more general initial state, and consider the
electron as a wave-packet. In particular, we investigate the energy spectrum of
the emitted radiation and show that in typical experimental situations some
features of the spectra shown in previous works are almost completely washed
out. Moreover, we show that at comparable relative uncertainties, the one in
the momentum of the incoming electron has a larger impact on the photon spectra
at a fixed observation direction than the one on the laser frequency.
| [
{
"created": "Mon, 8 Feb 2016 16:39:02 GMT",
"version": "v1"
},
{
"created": "Tue, 9 Feb 2016 10:12:30 GMT",
"version": "v2"
},
{
"created": "Tue, 3 May 2016 12:44:05 GMT",
"version": "v3"
}
] | 2016-05-04 | [
[
"Angioi",
"A.",
""
],
[
"Mackenroth",
"F.",
""
],
[
"Di Piazza",
"A.",
""
]
] | Nonlinear single Compton scattering has been thoroughly investigated in the literature under the assumption that initially the electron has a definite momentum. Here, we study a more general initial state, and consider the electron as a wave-packet. In particular, we investigate the energy spectrum of the emitted radiation and show that in typical experimental situations some features of the spectra shown in previous works are almost completely washed out. Moreover, we show that at comparable relative uncertainties, the one in the momentum of the incoming electron has a larger impact on the photon spectra at a fixed observation direction than the one on the laser frequency. |
hep-ph/9609475 | Maria Krawczyk | Maria Krawczyk (Institute of Theoretical Physics, University of
Warsaw) | Looking for a Light Higgs Particle at Present and Future Colliders | 16 pages, including 1 figure; Contribution to QS'96 Workshop, June
1996, Minsk, Belarus | null | null | IFT 20/96 | hep-ph | null | Present data do not rule out the light neutral Higgs particle $h$ or $A$ with
mass below 40--50 GeV in the framework of the general 2HDM ("Model II"). The
recent limits from LEP I on the parameters of the model, based on the Bjorken
process $Z \to Z h$, Higgs pair production $Z \to A h$ and the Yukawa process
$Z \to f {\bar f} A$ ($f= b$ quark or $\tau$ lepton) are presented. Including
limits on Higgs bosons masses from LEP I data additional constraints on the
allowed value for $ tan \beta$ for mass below 2 GeV, can be obtained from the
existing $(g-2)_{\mu}$ data. The improvement in the accuracy by factor 20 in
the forthcoming $(g-2)_{\mu}$ experiment E821 may lead to more stringent limits
on mass of neutral Higgs boson up to 30 GeV, or even higher if the mass
difference between $h$ and $A$ is larger than $M_Z$. The exclusion/discovery
potential of the gluon-gluon fusion in $ep$ collision at HERA is also
discussed. Already for a luminosity $ L_{ep} =25 pb^{-1}$ this measurement may
lead to more stringent limits on $ tan \beta$ for the mass range 5-15 GeV,
especially for the pseudoscalar case. In addition the possible search for very
light Higgs particle in $\gamma \gamma$ fusion at low energy (10 GeV) LC is
described. It may improve bounds considerably compared to the present limits
for mass around between 1.5 and 8 GeV assuming the luminosity $10 fb^{-1}$.
| [
{
"created": "Wed, 25 Sep 1996 16:45:22 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Krawczyk",
"Maria",
"",
"Institute of Theoretical Physics, University of\n Warsaw"
]
] | Present data do not rule out the light neutral Higgs particle $h$ or $A$ with mass below 40--50 GeV in the framework of the general 2HDM ("Model II"). The recent limits from LEP I on the parameters of the model, based on the Bjorken process $Z \to Z h$, Higgs pair production $Z \to A h$ and the Yukawa process $Z \to f {\bar f} A$ ($f= b$ quark or $\tau$ lepton) are presented. Including limits on Higgs bosons masses from LEP I data additional constraints on the allowed value for $ tan \beta$ for mass below 2 GeV, can be obtained from the existing $(g-2)_{\mu}$ data. The improvement in the accuracy by factor 20 in the forthcoming $(g-2)_{\mu}$ experiment E821 may lead to more stringent limits on mass of neutral Higgs boson up to 30 GeV, or even higher if the mass difference between $h$ and $A$ is larger than $M_Z$. The exclusion/discovery potential of the gluon-gluon fusion in $ep$ collision at HERA is also discussed. Already for a luminosity $ L_{ep} =25 pb^{-1}$ this measurement may lead to more stringent limits on $ tan \beta$ for the mass range 5-15 GeV, especially for the pseudoscalar case. In addition the possible search for very light Higgs particle in $\gamma \gamma$ fusion at low energy (10 GeV) LC is described. It may improve bounds considerably compared to the present limits for mass around between 1.5 and 8 GeV assuming the luminosity $10 fb^{-1}$. |
1603.05198 | Lance Labun | Jiunn-Wei Chen, Jian Deng, Hiroaki Kohyama, and Lance Labun | Universal relations between nongaussian fluctuations in heavy-ion
collisions | 5 pages, 6 figures, revtex style; v2 as published | Phys. Rev. D 95, 014038 (2017) | 10.1103/PhysRevD.95.014038 | MIT-CTP/4783 | hep-ph nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We show that universality near a critical end point implies a characteristic
relation between third- and fourth-order baryon susceptibilities $\chi_3$ and
$\chi_4$, resulting in a banana-shaped loop when $\chi_4$ is plotted as a
function of $\chi_3$ along a freeze-out line. Including the individual
enhancements of $\chi_3$ and $\chi_4$ near a critical point, these features may
be a consistent set of observations supporting the interpretation of baryon
fluctuations data as arising from criticality.
| [
{
"created": "Wed, 16 Mar 2016 18:04:21 GMT",
"version": "v1"
},
{
"created": "Tue, 11 Apr 2017 22:08:42 GMT",
"version": "v2"
}
] | 2017-04-13 | [
[
"Chen",
"Jiunn-Wei",
""
],
[
"Deng",
"Jian",
""
],
[
"Kohyama",
"Hiroaki",
""
],
[
"Labun",
"Lance",
""
]
] | We show that universality near a critical end point implies a characteristic relation between third- and fourth-order baryon susceptibilities $\chi_3$ and $\chi_4$, resulting in a banana-shaped loop when $\chi_4$ is plotted as a function of $\chi_3$ along a freeze-out line. Including the individual enhancements of $\chi_3$ and $\chi_4$ near a critical point, these features may be a consistent set of observations supporting the interpretation of baryon fluctuations data as arising from criticality. |
2408.07717 | Harleen Dahiya Dr. | Satyajit Puhan and Harleen Dahiya | Spatial and Transverse structure of Heavy B- and D-mesons | 4 pages. Presented in the 16th International Conference on Heavy
Quarks and Leptons (HQL 2023) held at TIFR, Mumbai, Maharashtra, India | PoS HQL2023 (2024) 089 | 10.22323/1.462.0089 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We have investigated the unpolarized valence quark generalized parton
distribution functions (GPDs) and parton distribution functions (PDFs) for
heavy spin-$0$, $B$- and $D$-mesons in the light-front quark model (LFQM). PDFs
have been extracted from unpolarized $f_1(x,\textbf{k}^2_{\perp})$ transverse
momentum-dependent parton distribution functions (TMDs). We have solved the
quark-quark correlation function to have an unpolarized $H(x,\zeta,t)$ GPD. The
unpolarized GPDs at zero skewness ($\zeta=0$) lead to describing the
electromagnetic form factors (EMFFs) ($F_M(t)$) and gravitational form factors
(GFFs)($A_M(t)$) of the mesons.
| [
{
"created": "Wed, 14 Aug 2024 07:14:20 GMT",
"version": "v1"
}
] | 2024-08-16 | [
[
"Puhan",
"Satyajit",
""
],
[
"Dahiya",
"Harleen",
""
]
] | We have investigated the unpolarized valence quark generalized parton distribution functions (GPDs) and parton distribution functions (PDFs) for heavy spin-$0$, $B$- and $D$-mesons in the light-front quark model (LFQM). PDFs have been extracted from unpolarized $f_1(x,\textbf{k}^2_{\perp})$ transverse momentum-dependent parton distribution functions (TMDs). We have solved the quark-quark correlation function to have an unpolarized $H(x,\zeta,t)$ GPD. The unpolarized GPDs at zero skewness ($\zeta=0$) lead to describing the electromagnetic form factors (EMFFs) ($F_M(t)$) and gravitational form factors (GFFs)($A_M(t)$) of the mesons. |
0802.0956 | Grigory Vereshkov | Yury Novoseltsev, Rita Novoseltseva, Grigory Vereshkov (INR RAS,
Moscow) | Multiplicity of photohadronization and photon--hadron scaling violation | 5 pages, 3 figures; v2: reference corrected | J.Phys.G36:025009,2009 | 10.1088/0954-3899/36/2/025009 | null | hep-ph | null | The method of scaling transformations permitting to carry out the
reconstruction of cross sections of $\gamma N$ and $\gamma\gamma$ interactions
on the basis of cross sections of nucleon-(anti)nucleon interactions is
suggested. The photon--hadron scaling violation is a consequence of dependence
of scaling transformation parameter $\bar n(s)$ on the energy. The universal
function $\bar n(s)$ is interpreted as the multiplicity of photohadronization.
This function is established by processing the data on $\gamma p$ cross
sections in the low energy region $\sqrt{s}< 20 \GeV$ and is extrapolated to
the high energy region up to $\sqrt{s}\sim 200 \GeV$. The results of the
reconstruction of $\gamma N$ cross sections at high energies and of
$\gamma\gamma$ ones at all energies are in a remarkable agreement with
available experimental data.
| [
{
"created": "Thu, 7 Feb 2008 12:08:36 GMT",
"version": "v1"
},
{
"created": "Tue, 12 Feb 2008 11:28:00 GMT",
"version": "v2"
}
] | 2009-02-16 | [
[
"Novoseltsev",
"Yury",
"",
"INR RAS,\n Moscow"
],
[
"Novoseltseva",
"Rita",
"",
"INR RAS,\n Moscow"
],
[
"Vereshkov",
"Grigory",
"",
"INR RAS,\n Moscow"
]
] | The method of scaling transformations permitting to carry out the reconstruction of cross sections of $\gamma N$ and $\gamma\gamma$ interactions on the basis of cross sections of nucleon-(anti)nucleon interactions is suggested. The photon--hadron scaling violation is a consequence of dependence of scaling transformation parameter $\bar n(s)$ on the energy. The universal function $\bar n(s)$ is interpreted as the multiplicity of photohadronization. This function is established by processing the data on $\gamma p$ cross sections in the low energy region $\sqrt{s}< 20 \GeV$ and is extrapolated to the high energy region up to $\sqrt{s}\sim 200 \GeV$. The results of the reconstruction of $\gamma N$ cross sections at high energies and of $\gamma\gamma$ ones at all energies are in a remarkable agreement with available experimental data. |
hep-ph/0003071 | Richard Shurtleff | Richard Shurtleff | Neutrino Proper Time? | 12 pages, 6 figures, LaTeX | null | null | null | hep-ph | null | An electron neutrino can have the quantum phase of an electron, i.e. share
its internal clock, if the neutrino takes a path in space-time that is not in
the direction of its energy-momentum. Each flavor neutrino would then have a
different internal clock; a muon neutrino would have a muon clock and a tau
neutrino would have a tau clock. Perhaps surprisingly, there is some evidence
suggesting neutrinos have such clocks. If muon neutrinos travel on space-like
paths then some atmospheric muon neutrinos would take such paths backwards into
outer space and not be observed. These are lost at the source and have nothing
to do with oscillations or flavor-changing in flight. The expected depletion of
source muon neutrinos is shown here to be 9%, which accounts for half of the
missing muon neutrino source flux reported by Super-Kamiokande. Since there is
no depletion in the electron neutrino flux source reported at SK and SN1987A
electron neutrinos seem to have traveled at the speed of light, the electron
neutrino travels on a light-like path. Accelerator-based experiments could be
arranged to confirm the reverse motion of muon neutrinos.
| [
{
"created": "Wed, 8 Mar 2000 23:33:48 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Shurtleff",
"Richard",
""
]
] | An electron neutrino can have the quantum phase of an electron, i.e. share its internal clock, if the neutrino takes a path in space-time that is not in the direction of its energy-momentum. Each flavor neutrino would then have a different internal clock; a muon neutrino would have a muon clock and a tau neutrino would have a tau clock. Perhaps surprisingly, there is some evidence suggesting neutrinos have such clocks. If muon neutrinos travel on space-like paths then some atmospheric muon neutrinos would take such paths backwards into outer space and not be observed. These are lost at the source and have nothing to do with oscillations or flavor-changing in flight. The expected depletion of source muon neutrinos is shown here to be 9%, which accounts for half of the missing muon neutrino source flux reported by Super-Kamiokande. Since there is no depletion in the electron neutrino flux source reported at SK and SN1987A electron neutrinos seem to have traveled at the speed of light, the electron neutrino travels on a light-like path. Accelerator-based experiments could be arranged to confirm the reverse motion of muon neutrinos. |
hep-ph/9409315 | null | Christopher T. Hill and Xinmin Zhang | Z -> b\bar{b} Versus Dynamical Electroweak Symmetry Breaking involving
the Top Quark | LaTex file, 19 pages + 2 Figs., Fermilab-Pub-94/231-T | Phys.Rev.D51:3563-3568,1995 | 10.1103/PhysRevD.51.3563 | null | hep-ph | null | In models of dynamical electroweak symmetry breaking which sensitively
involve the third generation, such as top quark condensation, the effects of
the new dynamics can show up experimentally in Z->b\bar{b}. We compare the
sensitivity of Z->b\bar{b} and top quark production at the Tevatron to models
of the new physics. Z->b\bar{b} is a relatively more sensitive probe to new
strongly coupled U(1) gauge bosons, while it is generally less sensitive a
probe to new physics involving color octet gauge bosons as is top quark
production itself. Nonetheless, to accomodate a significant excess in
Z->b\bar{b} requires choosing model parameters that may be ruled out within run
I(b) at the Tevatron.
| [
{
"created": "Wed, 14 Sep 1994 20:39:01 GMT",
"version": "v1"
}
] | 2011-07-18 | [
[
"Hill",
"Christopher T.",
""
],
[
"Zhang",
"Xinmin",
""
]
] | In models of dynamical electroweak symmetry breaking which sensitively involve the third generation, such as top quark condensation, the effects of the new dynamics can show up experimentally in Z->b\bar{b}. We compare the sensitivity of Z->b\bar{b} and top quark production at the Tevatron to models of the new physics. Z->b\bar{b} is a relatively more sensitive probe to new strongly coupled U(1) gauge bosons, while it is generally less sensitive a probe to new physics involving color octet gauge bosons as is top quark production itself. Nonetheless, to accomodate a significant excess in Z->b\bar{b} requires choosing model parameters that may be ruled out within run I(b) at the Tevatron. |
hep-ph/9710309 | Martin Maul | M. Maul, A. Schafer (Regensburg U.), E. Mirkes (Karlsruhe U.), G.
Radel (CERN) | Asymmetry distributions and mass effects in dijet events at a polarized
HERA | 18 pages, LaTeX, minor stylistic changes for Z.Phys.C | Eur.Phys.J.C5:485-491,1998 | 10.1007/s100520050292 | null | hep-ph | null | The asymmetry distributions for several kinematic variables are considered
for finding a systematic way to maximize the signal for the extraction of the
polarized gluon density. The relevance of mass effects for the corresponding
dijet cross section is discussed and the different approximations for including
mass effects are compared. We also compare via the programs Pepsi and Mepjet
two different Monte Carlo (MC) approaches for simulating the expected signal in
the dijet asymmetry at a polarized HERA.
| [
{
"created": "Thu, 9 Oct 1997 22:57:13 GMT",
"version": "v1"
},
{
"created": "Mon, 23 Feb 1998 18:44:32 GMT",
"version": "v2"
}
] | 2011-09-13 | [
[
"Maul",
"M.",
"",
"Regensburg U."
],
[
"Schafer",
"A.",
"",
"Regensburg U."
],
[
"Mirkes",
"E.",
"",
"Karlsruhe U."
],
[
"Radel",
"G.",
"",
"CERN"
]
] | The asymmetry distributions for several kinematic variables are considered for finding a systematic way to maximize the signal for the extraction of the polarized gluon density. The relevance of mass effects for the corresponding dijet cross section is discussed and the different approximations for including mass effects are compared. We also compare via the programs Pepsi and Mepjet two different Monte Carlo (MC) approaches for simulating the expected signal in the dijet asymmetry at a polarized HERA. |
2101.08320 | Benjamin Nachman | Gregor Kasieczka (ed), Benjamin Nachman (ed), David Shih (ed), Oz
Amram, Anders Andreassen, Kees Benkendorfer, Blaz Bortolato, Gustaaf
Brooijmans, Florencia Canelli, Jack H. Collins, Biwei Dai, Felipe F. De
Freitas, Barry M. Dillon, Ioan-Mihail Dinu, Zhongtian Dong, Julien Donini,
Javier Duarte, D. A. Faroughy, Julia Gonski, Philip Harris, Alan Kahn, Jernej
F. Kamenik, Charanjit K. Khosa, Patrick Komiske, Luc Le Pottier, Pablo
Mart\'in-Ramiro, Andrej Matevc, Eric Metodiev, Vinicius Mikuni, In\^es Ochoa,
Sang Eon Park, Maurizio Pierini, Dylan Rankin, Veronica Sanz, Nilai Sarda,
Uro\u{s} Seljak, Aleks Smolkovic, George Stein, Cristina Mantilla Suarez,
Manuel Szewc, Jesse Thaler, Steven Tsan, Silviu-Marian Udrescu, Louis Vaslin,
Jean-Roch Vlimant, Daniel Williams, and Mikaeel Yunus | The LHC Olympics 2020: A Community Challenge for Anomaly Detection in
High Energy Physics | 108 pages, 53 figures, 3 tables | null | 10.1088/1361-6633/ac36b9 | null | hep-ph hep-ex physics.data-an | http://creativecommons.org/licenses/by/4.0/ | A new paradigm for data-driven, model-agnostic new physics searches at
colliders is emerging, and aims to leverage recent breakthroughs in anomaly
detection and machine learning. In order to develop and benchmark new anomaly
detection methods within this framework, it is essential to have standard
datasets. To this end, we have created the LHC Olympics 2020, a community
challenge accompanied by a set of simulated collider events. Participants in
these Olympics have developed their methods using an R&D dataset and then
tested them on black boxes: datasets with an unknown anomaly (or not). This
paper will review the LHC Olympics 2020 challenge, including an overview of the
competition, a description of methods deployed in the competition, lessons
learned from the experience, and implications for data analyses with future
datasets as well as future colliders.
| [
{
"created": "Wed, 20 Jan 2021 21:03:06 GMT",
"version": "v1"
}
] | 2021-12-22 | [
[
"Kasieczka",
"Gregor",
"",
"ed"
],
[
"Nachman",
"Benjamin",
"",
"ed"
],
[
"Shih",
"David",
"",
"ed"
],
[
"Amram",
"Oz",
""
],
[
"Andreassen",
"Anders",
""
],
[
"Benkendorfer",
"Kees",
""
],
[
"Bortolato",
"Blaz",
""
],
[
"Brooijmans",
"Gustaaf",
""
],
[
"Canelli",
"Florencia",
""
],
[
"Collins",
"Jack H.",
""
],
[
"Dai",
"Biwei",
""
],
[
"De Freitas",
"Felipe F.",
""
],
[
"Dillon",
"Barry M.",
""
],
[
"Dinu",
"Ioan-Mihail",
""
],
[
"Dong",
"Zhongtian",
""
],
[
"Donini",
"Julien",
""
],
[
"Duarte",
"Javier",
""
],
[
"Faroughy",
"D. A.",
""
],
[
"Gonski",
"Julia",
""
],
[
"Harris",
"Philip",
""
],
[
"Kahn",
"Alan",
""
],
[
"Kamenik",
"Jernej F.",
""
],
[
"Khosa",
"Charanjit K.",
""
],
[
"Komiske",
"Patrick",
""
],
[
"Pottier",
"Luc Le",
""
],
[
"Martín-Ramiro",
"Pablo",
""
],
[
"Matevc",
"Andrej",
""
],
[
"Metodiev",
"Eric",
""
],
[
"Mikuni",
"Vinicius",
""
],
[
"Ochoa",
"Inês",
""
],
[
"Park",
"Sang Eon",
""
],
[
"Pierini",
"Maurizio",
""
],
[
"Rankin",
"Dylan",
""
],
[
"Sanz",
"Veronica",
""
],
[
"Sarda",
"Nilai",
""
],
[
"Seljak",
"Urous",
""
],
[
"Smolkovic",
"Aleks",
""
],
[
"Stein",
"George",
""
],
[
"Suarez",
"Cristina Mantilla",
""
],
[
"Szewc",
"Manuel",
""
],
[
"Thaler",
"Jesse",
""
],
[
"Tsan",
"Steven",
""
],
[
"Udrescu",
"Silviu-Marian",
""
],
[
"Vaslin",
"Louis",
""
],
[
"Vlimant",
"Jean-Roch",
""
],
[
"Williams",
"Daniel",
""
],
[
"Yunus",
"Mikaeel",
""
]
] | A new paradigm for data-driven, model-agnostic new physics searches at colliders is emerging, and aims to leverage recent breakthroughs in anomaly detection and machine learning. In order to develop and benchmark new anomaly detection methods within this framework, it is essential to have standard datasets. To this end, we have created the LHC Olympics 2020, a community challenge accompanied by a set of simulated collider events. Participants in these Olympics have developed their methods using an R&D dataset and then tested them on black boxes: datasets with an unknown anomaly (or not). This paper will review the LHC Olympics 2020 challenge, including an overview of the competition, a description of methods deployed in the competition, lessons learned from the experience, and implications for data analyses with future datasets as well as future colliders. |
hep-ph/9911347 | Marina Artuso | Marina Artuso | Flavour Physics: the questions, the clues and the challenges | 22 pages, 16 figures, Plenary talk at EPS HEP '99, Tampere, Finland,
July 1999 2nd version: references added | null | null | null | hep-ph | null | Flavour physics addresses some of the questions for which the Standard Model
does not provide a satisfactory and complete answer: the origin of the
replication of the fundamental constituents and of their mass hierarchy. This
paper reviews some of the theoretical approaches and the experimental
strategies that can lead us to a more complete picture. Results included in
this review are |V_{cb}|= 0.0382 +/- 0.0032, |V_{ub}/V_{cb}|=0.085 +/- 0.023
and a preliminary measurement of the branching fraction of B -> pi^+ pi ^- =
(0.47 ({+0.18}-{-0.15}) +/- 0.06) x 10^{-5}.}
| [
{
"created": "Sat, 13 Nov 1999 16:58:19 GMT",
"version": "v1"
},
{
"created": "Wed, 24 Nov 1999 17:00:23 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Artuso",
"Marina",
""
]
] | Flavour physics addresses some of the questions for which the Standard Model does not provide a satisfactory and complete answer: the origin of the replication of the fundamental constituents and of their mass hierarchy. This paper reviews some of the theoretical approaches and the experimental strategies that can lead us to a more complete picture. Results included in this review are |V_{cb}|= 0.0382 +/- 0.0032, |V_{ub}/V_{cb}|=0.085 +/- 0.023 and a preliminary measurement of the branching fraction of B -> pi^+ pi ^- = (0.47 ({+0.18}-{-0.15}) +/- 0.06) x 10^{-5}.} |
hep-ph/9304221 | Carlo Giunti | S.M. Bilenky, C. Giunti and V. Wataghin | The Process " Pbar P -> E- E+ " with Polarized Initial Particles and
Proton Form Factors in Time-Like Region | DFTT 13/93. LaTeX file, 11 pages + 3 figures (included) | Z.Phys.C59:475-480,1993 | 10.1007/BF01498628 | null | hep-ph | null | The discussion on the asymptotical behaviour of the form factors in the
space-like and time-like regions have been corrected and clarified. Fig.3 has
been replaced by an improved analysis of the data.
| [
{
"created": "Tue, 6 Apr 1993 15:13:52 GMT",
"version": "v1"
},
{
"created": "Thu, 22 Apr 1993 16:48:44 GMT",
"version": "v2"
}
] | 2010-11-15 | [
[
"Bilenky",
"S. M.",
""
],
[
"Giunti",
"C.",
""
],
[
"Wataghin",
"V.",
""
]
] | The discussion on the asymptotical behaviour of the form factors in the space-like and time-like regions have been corrected and clarified. Fig.3 has been replaced by an improved analysis of the data. |
1408.1976 | Igor Shovkovy | Lifang Xia, E. V. Gorbar, V. A. Miransky and I. A. Shovkovy | Chiral asymmetry in cold QED plasma in a strong magnetic field | 13 pages, 5 figures; published version with minor changes and
references added | Phys. Rev. D 90, 085011 (2014) | 10.1103/PhysRevD.90.085011 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The interaction induced chiral asymmetry is calculated in cold QED plasma
beyond the weak-field approximation. By making use of the recently developed
Landau-level representation for the fermion self-energy, the chiral shift and
the parity-even chiral chemical potential function are obtained with the help
of numerical methods. The results are used to quantify the chiral asymmetry of
the Fermi surface in dense QED matter. Because of the weakness of the QED
interactions, the value of the asymmetry appears to be rather small even in the
strongest magnetic fields and at the highest stellar densities. However, the
analogous asymmetry can be substantial in the case of dense quark matter.
| [
{
"created": "Fri, 8 Aug 2014 20:43:07 GMT",
"version": "v1"
},
{
"created": "Sat, 11 Oct 2014 22:04:22 GMT",
"version": "v2"
}
] | 2014-10-14 | [
[
"Xia",
"Lifang",
""
],
[
"Gorbar",
"E. V.",
""
],
[
"Miransky",
"V. A.",
""
],
[
"Shovkovy",
"I. A.",
""
]
] | The interaction induced chiral asymmetry is calculated in cold QED plasma beyond the weak-field approximation. By making use of the recently developed Landau-level representation for the fermion self-energy, the chiral shift and the parity-even chiral chemical potential function are obtained with the help of numerical methods. The results are used to quantify the chiral asymmetry of the Fermi surface in dense QED matter. Because of the weakness of the QED interactions, the value of the asymmetry appears to be rather small even in the strongest magnetic fields and at the highest stellar densities. However, the analogous asymmetry can be substantial in the case of dense quark matter. |
2302.03443 | Victor Molokoedov | A.L. Kataev and V.S. Molokoedov | The generalized Crewther relation and V-scheme: analytic $O(\alpha^4_s)$
results in QCD and QED | 29 pages, 1 Table. Prepared for the Proceedings of VII Int.
Conference "Models in QFT", 10-14 October, 2022, Saint-Petersburg | null | null | INR-TH-2023-001 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Using the analytical $\rm{\overline{MS}}$-scheme three-loop contribution to
the perturbative Coulomb-like part of the static color potential of heavy
quark-antiquark system, we obtain the analytical expression for the
fourth-order $\beta$-function in the gauge-invariant effective V-scheme in the
case of the generic simple gauge group. Also we present the Adler function of
electron-positron annihilation into hadrons and the coefficient function of the
Bjorken polarized sum rule in the V-scheme up to $\alpha^4_s$ terms. We
demonstrate that at this level of PT in this effective scheme the
$\beta$-function is factorized in the conformal symmetry breaking term of the
generalized Crewther relation, which connects the flavor non-singlet
contributions to the Adler and Bjorken polarized sum rule functions. We prove
why this relation will be true in other gauge-invariant renormalization schemes
as well. The obtained results enable to reveal the difference between the
V-scheme $\beta$-function in QED and the Gell-Man--Low $\Psi$-function. This
distinction arises due to the presence of the light-by-light type scattering
corrections first appearing in the static potential at the three-loop level.
| [
{
"created": "Tue, 7 Feb 2023 12:57:15 GMT",
"version": "v1"
}
] | 2023-02-08 | [
[
"Kataev",
"A. L.",
""
],
[
"Molokoedov",
"V. S.",
""
]
] | Using the analytical $\rm{\overline{MS}}$-scheme three-loop contribution to the perturbative Coulomb-like part of the static color potential of heavy quark-antiquark system, we obtain the analytical expression for the fourth-order $\beta$-function in the gauge-invariant effective V-scheme in the case of the generic simple gauge group. Also we present the Adler function of electron-positron annihilation into hadrons and the coefficient function of the Bjorken polarized sum rule in the V-scheme up to $\alpha^4_s$ terms. We demonstrate that at this level of PT in this effective scheme the $\beta$-function is factorized in the conformal symmetry breaking term of the generalized Crewther relation, which connects the flavor non-singlet contributions to the Adler and Bjorken polarized sum rule functions. We prove why this relation will be true in other gauge-invariant renormalization schemes as well. The obtained results enable to reveal the difference between the V-scheme $\beta$-function in QED and the Gell-Man--Low $\Psi$-function. This distinction arises due to the presence of the light-by-light type scattering corrections first appearing in the static potential at the three-loop level. |
hep-ph/0411136 | Marek Karliner | Marek Karliner and Harry J. Lipkin | On a possible tetraquark cousin of the Theta^+ | Expanded discussion of allowed and forbidden decay modes | Phys.Lett. B612 (2005) 197-200 | 10.1016/j.physletb.2005.03.038 | Cavendish-HEP-04/30, TAUP 2788-04, WIS/25/04-SEPT-DPP,
ANL-HEP-PR-04-113 | hep-ph | null | If a narrow Theta^+ pentaquark exists, it is likely that a ud\bar s-ud
triquark-diquark configuration is a significant component of its wave function.
If so, the mechanism responsible for the binding of a triquark and a diquark is
also likely to bind the triquark to an \bar s antiquark. We discuss the
expected properties of such a ud\bar s-\bar s tetraquark meson. In particular,
we point out that for a 0^+ isoscalar ud\bar s\bar s meson the lowest allowed
decay mode is a four-body K K pi pi channel with a small phase space and a
distinctive experimental signature.
| [
{
"created": "Wed, 10 Nov 2004 00:44:59 GMT",
"version": "v1"
},
{
"created": "Tue, 8 Feb 2005 17:19:35 GMT",
"version": "v2"
}
] | 2010-04-05 | [
[
"Karliner",
"Marek",
""
],
[
"Lipkin",
"Harry J.",
""
]
] | If a narrow Theta^+ pentaquark exists, it is likely that a ud\bar s-ud triquark-diquark configuration is a significant component of its wave function. If so, the mechanism responsible for the binding of a triquark and a diquark is also likely to bind the triquark to an \bar s antiquark. We discuss the expected properties of such a ud\bar s-\bar s tetraquark meson. In particular, we point out that for a 0^+ isoscalar ud\bar s\bar s meson the lowest allowed decay mode is a four-body K K pi pi channel with a small phase space and a distinctive experimental signature. |
hep-ph/9806397 | Thomas G. Rizzo | Thomas G. Rizzo | Gauge Kinetic Mixing and Leptophobic $Z'$ in $E_6$ and SO(10) | several typos corrected | Phys. Rev. D 59, 015020 (1998) | 10.1103/PhysRevD.59.015020 | SLAC-PUB-7838 | hep-ph | null | We examine the influence of gauge kinetic mixing on the couplings of a TeV
scale $Z'$ in both $E_6$ and SO(10) models. The strength of such mixing, which
arises due to the existence of incomplete matter representations at low scale,
can be described by a single parameter, $\delta$. The value of this parameter
can significantly influence the ability of both hadron and lepton colliders to
detect a $Z'$ using conventional search techniques. In addition, $\delta \neq
0$ also adds to the complexities involved in separating $E_6$ $Z'$ models from
those arising from alternative scenarios. Employing a reasonable set of
assumptions we have determined the allowed range for this parameter within a
wide class of models via an RGE analysis. In particular, given the requirements
of Standard Model gauge coupling unification, anomaly freedom and
perturbativity up to the GUT scale, we demonstrate that the necessary condition
for exact leptophobia in $\eta$ type $E_6$ models, $\delta=-1/3$, is impossible
to achieve in this scenario. Furthermore we show that the allowed range for
$\delta$ is rather restricted for arbitrary values of the mixing between the
$U(1)_\chi$ and $U(1)_\psi$ type couplings. The SO(10) $Z'$ model $\chi$ is
discussed as a separate case since it requires special attention.
| [
{
"created": "Wed, 17 Jun 1998 20:52:55 GMT",
"version": "v1"
},
{
"created": "Tue, 22 Sep 1998 17:51:33 GMT",
"version": "v2"
}
] | 2016-08-25 | [
[
"Rizzo",
"Thomas G.",
""
]
] | We examine the influence of gauge kinetic mixing on the couplings of a TeV scale $Z'$ in both $E_6$ and SO(10) models. The strength of such mixing, which arises due to the existence of incomplete matter representations at low scale, can be described by a single parameter, $\delta$. The value of this parameter can significantly influence the ability of both hadron and lepton colliders to detect a $Z'$ using conventional search techniques. In addition, $\delta \neq 0$ also adds to the complexities involved in separating $E_6$ $Z'$ models from those arising from alternative scenarios. Employing a reasonable set of assumptions we have determined the allowed range for this parameter within a wide class of models via an RGE analysis. In particular, given the requirements of Standard Model gauge coupling unification, anomaly freedom and perturbativity up to the GUT scale, we demonstrate that the necessary condition for exact leptophobia in $\eta$ type $E_6$ models, $\delta=-1/3$, is impossible to achieve in this scenario. Furthermore we show that the allowed range for $\delta$ is rather restricted for arbitrary values of the mixing between the $U(1)_\chi$ and $U(1)_\psi$ type couplings. The SO(10) $Z'$ model $\chi$ is discussed as a separate case since it requires special attention. |
2004.09497 | Ye Xu | Ye Xu | Measurement of TeV dark particles due to decay of heavy dark matter in
the earth core at IceCube | 10 pages, 4 figures, accepted for publication in Physics of the Dark
Universe. arXiv admin note: substantial text overlap with arXiv:1904.12266,
arXiv:1910.11158 | Physics of the Dark Universe 32, 100809, 2021 | null | null | hep-ph astro-ph.CO hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the present paper, it is assumed that there exist two species of dark
matter: a heavy dark matter particle (HDM) with the mass of O(TeV) which is
generated in early universe and a lighter dark matter particle (LDM) which is a
relativistic product due to the decay of HDM. HDMs, captured by the earth,
decay to high energy LDMs, and these particles can be measured by km$^3$
neutrino telescopes, like the IceCube detector. A $Z^{\prime}$ portal dark
matter model is taken for LDMs to interact with nuclei via a neutral current
interaction mediated by a heavy gauge boson $Z^{\prime}$. With the different
lifetimes of decay of HDMs and Z$^{\prime}$ masses, the event rates of LDMs,
measured by IceCube, are evaluated in the energy range between 1 TeV and 100
TeV. According to the IceCube data, the upper limit for LDM fluxes is estimated
at 90\% C.L. at IceCube. Finally, it is proved that LDMs could be directly
detected in the energy range betwen O(1TeV) and O(10TeV) at IceCube with
$m_{Z^{\prime}} \lesssim 500 GeV$ and $\tau_{\phi} \lesssim 10^{21}$ s.
| [
{
"created": "Sun, 19 Apr 2020 03:54:48 GMT",
"version": "v1"
},
{
"created": "Thu, 25 Mar 2021 07:25:20 GMT",
"version": "v2"
}
] | 2021-04-08 | [
[
"Xu",
"Ye",
""
]
] | In the present paper, it is assumed that there exist two species of dark matter: a heavy dark matter particle (HDM) with the mass of O(TeV) which is generated in early universe and a lighter dark matter particle (LDM) which is a relativistic product due to the decay of HDM. HDMs, captured by the earth, decay to high energy LDMs, and these particles can be measured by km$^3$ neutrino telescopes, like the IceCube detector. A $Z^{\prime}$ portal dark matter model is taken for LDMs to interact with nuclei via a neutral current interaction mediated by a heavy gauge boson $Z^{\prime}$. With the different lifetimes of decay of HDMs and Z$^{\prime}$ masses, the event rates of LDMs, measured by IceCube, are evaluated in the energy range between 1 TeV and 100 TeV. According to the IceCube data, the upper limit for LDM fluxes is estimated at 90\% C.L. at IceCube. Finally, it is proved that LDMs could be directly detected in the energy range betwen O(1TeV) and O(10TeV) at IceCube with $m_{Z^{\prime}} \lesssim 500 GeV$ and $\tau_{\phi} \lesssim 10^{21}$ s. |
2211.13136 | Vicent Mateu | A. Bris, N.G. Gracia, V. Mateu | Oriented Event Shapes for massive Quarks | 4 pages, 7 figures, contribution to the XVth Quark Confinement and
the Hadron Spectrum Conference, Aug 2022 University of Stavanger | null | 10.1051/epjconf/202227403001 | IFT-UAM/CSIC-22-142 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this work we present the computation of so-called oriented event-shape
distributions for massive quarks up to $\mathcal{O}(\alpha_s)$, along with the
total oriented cross section in which one does not look at the geometric
properties of the momentum distribution for particles in the final state. We
consider the vector and axial-vector currents, and for the former, we find a
non-vanishing result at $\mathcal{O}(\alpha_s^0)$ that translates into a
significant enhancement as compared to the massless approximation. Our results
are an important ingredient for analyses that aim to determine the strong
coupling with high accuracy.
| [
{
"created": "Wed, 23 Nov 2022 17:09:46 GMT",
"version": "v1"
}
] | 2023-01-11 | [
[
"Bris",
"A.",
""
],
[
"Gracia",
"N. G.",
""
],
[
"Mateu",
"V.",
""
]
] | In this work we present the computation of so-called oriented event-shape distributions for massive quarks up to $\mathcal{O}(\alpha_s)$, along with the total oriented cross section in which one does not look at the geometric properties of the momentum distribution for particles in the final state. We consider the vector and axial-vector currents, and for the former, we find a non-vanishing result at $\mathcal{O}(\alpha_s^0)$ that translates into a significant enhancement as compared to the massless approximation. Our results are an important ingredient for analyses that aim to determine the strong coupling with high accuracy. |
1012.1649 | Johann Rafelski | Johann Rafelski and Jean Letessier | Particle Production in s_NN = 2.76 TeV Heavy Ion Collisions | 6 pages, PRC in presss | Phys.Rev.C83:054909,2011 | 10.1103/PhysRevC.83.054909 | null | hep-ph nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We obtain within the statistical hadronization model the hadron yields
$dh/dy$ in heavy ion reactions at $\sqrt{s_{NN}} = 2.76$ TeV. We discuss the
dependence both on hadronization temperature $T$, and on critical hadronization
pressure $P$. We consider observables distinguishing the hadronization models
and conditions.
| [
{
"created": "Wed, 8 Dec 2010 00:08:52 GMT",
"version": "v1"
},
{
"created": "Fri, 13 May 2011 23:55:39 GMT",
"version": "v2"
}
] | 2011-06-21 | [
[
"Rafelski",
"Johann",
""
],
[
"Letessier",
"Jean",
""
]
] | We obtain within the statistical hadronization model the hadron yields $dh/dy$ in heavy ion reactions at $\sqrt{s_{NN}} = 2.76$ TeV. We discuss the dependence both on hadronization temperature $T$, and on critical hadronization pressure $P$. We consider observables distinguishing the hadronization models and conditions. |
0910.3130 | Roberto Pittau | M.V. Garzelli, I. Malamos, R. Pittau | Feynman rules for the rational part of the Electroweak 1-loop amplitudes | Many thanks to Huasheng Shao for having recomputed, independently of
us, all of the ${\rm R_2}$ effective vertices. Thanks to his help and by
comparing with an independent computation we performed in a general $R_\xi$
gauge, we could fix, in the present version, the following formulae: the
vertex $A l \bar l$ in Eq. (3.6), the vertex $Z \phi^+ \phi^-$ in Eq. (3.8),
Eqs (3.16), (3.17) and (3.18) | JHEP 1001:040,2010; Erratum-ibid.1010:097,2010 | 10.1007/JHEP01(2010)040 10.1007/JHEP10(2010)097 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the complete set of Feynman rules producing the rational terms of
kind R_2 needed to perform any 1-loop calculation in the Electroweak Standard
Model. Our results are given both in the 't Hooft-Veltman and in the Four
Dimensional Helicity regularization schemes. We also verified, by using both
the 't Hooft-Feynman gauge and the Background Field Method, a huge set of Ward
identities -up to 4-points- for the complete rational part of the Electroweak
amplitudes. This provides a stringent check of our results and, as a
by-product, an explicit test of the gauge invariance of the Four Dimensional
Helicity regularization scheme in the complete Standard Model at 1-loop. The
formulae presented in this paper provide the last missing piece for completely
automatizing, in the framework of the OPP method, the 1-loop calculations in
the SU(3) X SU(2) X U(1) Standard Model.
| [
{
"created": "Fri, 16 Oct 2009 14:41:17 GMT",
"version": "v1"
},
{
"created": "Fri, 1 Oct 2010 15:52:52 GMT",
"version": "v2"
}
] | 2010-10-28 | [
[
"Garzelli",
"M. V.",
""
],
[
"Malamos",
"I.",
""
],
[
"Pittau",
"R.",
""
]
] | We present the complete set of Feynman rules producing the rational terms of kind R_2 needed to perform any 1-loop calculation in the Electroweak Standard Model. Our results are given both in the 't Hooft-Veltman and in the Four Dimensional Helicity regularization schemes. We also verified, by using both the 't Hooft-Feynman gauge and the Background Field Method, a huge set of Ward identities -up to 4-points- for the complete rational part of the Electroweak amplitudes. This provides a stringent check of our results and, as a by-product, an explicit test of the gauge invariance of the Four Dimensional Helicity regularization scheme in the complete Standard Model at 1-loop. The formulae presented in this paper provide the last missing piece for completely automatizing, in the framework of the OPP method, the 1-loop calculations in the SU(3) X SU(2) X U(1) Standard Model. |
hep-ph/9904355 | Jeonghyeon Song | Kang Young Lee, H.S. Song and JeongHyeon Song (SNU) | Polarization Effects on the $e+e- \to W^+W^-$ process with Large Extra
Dimensions | Final version to appear in Phys.Lett.B. More references are added | Phys.Lett. B464 (1999) 82-89 | 10.1016/S0370-2693(99)01012-6 | null | hep-ph | null | We study large extra dimension effects on the polarizations of the $W$ pair
and electron beam at the $e^+ e^-\to W^+ W^-$ process. It is shown that the
measurements of the cross section for transversely polarized $W$ pair with the
right-handed electron beam remarkably enhance the possibilities to see the low
scale quantum gravity effects. Higher Linear Collider bounds on the string
scale in this model can be obtained by using the left-handed electron beam.
| [
{
"created": "Fri, 16 Apr 1999 07:16:27 GMT",
"version": "v1"
},
{
"created": "Wed, 11 Aug 1999 04:43:38 GMT",
"version": "v2"
}
] | 2009-10-31 | [
[
"Lee",
"Kang Young",
"",
"SNU"
],
[
"Song",
"H. S.",
"",
"SNU"
],
[
"Song",
"JeongHyeon",
"",
"SNU"
]
] | We study large extra dimension effects on the polarizations of the $W$ pair and electron beam at the $e^+ e^-\to W^+ W^-$ process. It is shown that the measurements of the cross section for transversely polarized $W$ pair with the right-handed electron beam remarkably enhance the possibilities to see the low scale quantum gravity effects. Higher Linear Collider bounds on the string scale in this model can be obtained by using the left-handed electron beam. |
1512.09148 | Andrew K. Meadowcroft | Miguel Crispim Rom\~ao, Athanasios Karozas, Stephen F. King, George K.
Leontaris, Andrew K. Meadowcroft | MSSM from F-theory SU(5) with Klein Monodromy | null | Phys. Rev. D 93, 126007 (2016) | 10.1103/PhysRevD.93.126007 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We revisit a class of $SU(5)$ SUSY GUT models which arise in the context of
the spectral cover with Klein Group monodromy $V_4=Z_2\times Z_2$. We show that
$Z_2$ matter parities can be realised via new geometric symmetries respected by
the spectral cover. We discuss a particular example of this kind, where the low
energy effective theory below the GUT scale is just the MSSM with no exotics
and standard matter parity, extended by the seesaw mechanism with two
right-handed neutrinos.
| [
{
"created": "Wed, 30 Dec 2015 21:01:37 GMT",
"version": "v1"
}
] | 2016-07-06 | [
[
"Romão",
"Miguel Crispim",
""
],
[
"Karozas",
"Athanasios",
""
],
[
"King",
"Stephen F.",
""
],
[
"Leontaris",
"George K.",
""
],
[
"Meadowcroft",
"Andrew K.",
""
]
] | We revisit a class of $SU(5)$ SUSY GUT models which arise in the context of the spectral cover with Klein Group monodromy $V_4=Z_2\times Z_2$. We show that $Z_2$ matter parities can be realised via new geometric symmetries respected by the spectral cover. We discuss a particular example of this kind, where the low energy effective theory below the GUT scale is just the MSSM with no exotics and standard matter parity, extended by the seesaw mechanism with two right-handed neutrinos. |
1502.05346 | Alexander Studenikin | Ilya A. Balantsev, Alexander I. Studenikin | Spin light of relativistic electrons in neutrino fluxes | 8 pages in LaTex, one figure, 23 references, based on the poster
presentation at the XXXVII International Conference on High Energy Physics,
Valencia, Spain, 2-9 July 2014 | Int. J. Mod. Phys. A 30 (2015) 1530044 | 10.1142/S0217751X15300446 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A new mechanism of electromagnetic radiation by electrons under the influence
of a dense neutrino flux, termed "the spin light of electron" in neutrino flux
($SLe_\nu$), is considered. It is shown that in the case when electrons are
moving against the neutrino flux with relativistic energy there is a reasonable
increase of the efficiency of the energy transfer from the neutrino flux to the
electromagnetic radiation by the $SLe_\nu$ mechanism. The proposed radiation
process is applied to an astrophysical environment with characteristics
peculiar to supernovae. It is shown that a reasonable portion of energy of the
neutrino flux can be transferred by the $SLe_\nu$ to gamma-rays .
| [
{
"created": "Sat, 8 Nov 2014 21:31:27 GMT",
"version": "v1"
}
] | 2015-07-15 | [
[
"Balantsev",
"Ilya A.",
""
],
[
"Studenikin",
"Alexander I.",
""
]
] | A new mechanism of electromagnetic radiation by electrons under the influence of a dense neutrino flux, termed "the spin light of electron" in neutrino flux ($SLe_\nu$), is considered. It is shown that in the case when electrons are moving against the neutrino flux with relativistic energy there is a reasonable increase of the efficiency of the energy transfer from the neutrino flux to the electromagnetic radiation by the $SLe_\nu$ mechanism. The proposed radiation process is applied to an astrophysical environment with characteristics peculiar to supernovae. It is shown that a reasonable portion of energy of the neutrino flux can be transferred by the $SLe_\nu$ to gamma-rays . |
hep-ph/9406317 | Abu-Leil "g." | Ghadir Abu Leil, W.J. Stirling | Anomalous quartic couplings in $ W^+W^- \gamma $ production at $e^+e^- $
colliders | 15 pages, DTP/94/10 | J.Phys. G21 (1995) 517-524 | 10.1088/0954-3899/21/4/003 | null | hep-ph | null | We study the process $e^+e^- \rightarrow W^+W^- \gamma$ at high-energy $e^+
e^-$ colliders to investigate the effect of genuine quartic
$W^+W^-\gamma\gamma$ and $W^+W^- Z\gamma$ anomalous couplings on the cross
section. Deviations from the Standard Model predictions are quantified. We show
how bounds on the anomalous couplings can be improved by choosing specific
initial state helicity combinations. The dependence of the anomalous
contributions on the collider energy is studied.
| [
{
"created": "Wed, 15 Jun 1994 14:22:14 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Leil",
"Ghadir Abu",
""
],
[
"Stirling",
"W. J.",
""
]
] | We study the process $e^+e^- \rightarrow W^+W^- \gamma$ at high-energy $e^+ e^-$ colliders to investigate the effect of genuine quartic $W^+W^-\gamma\gamma$ and $W^+W^- Z\gamma$ anomalous couplings on the cross section. Deviations from the Standard Model predictions are quantified. We show how bounds on the anomalous couplings can be improved by choosing specific initial state helicity combinations. The dependence of the anomalous contributions on the collider energy is studied. |
1803.01574 | Isaac Sanderson | Nicole F. Bell, Giorgio Busoni and Isaac W. Sanderson | Loop Effects in Direct Detection | 20 pages, 8 figures | null | 10.1088/1475-7516/2018/08/017 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider loop level contributions to dark matter scattering off nucleons
in cases where the spin independent scattering cross section is absent or
suppressed at tree level. In the case of a pseudoscalar interaction, for which
the tree level cross section is both spin-dependent and suppressed by 4 powers
of the exchanged momentum, we show that loop diagrams give rise to a non- zero
spin independent cross section. Importantly, if the pseudoscalar interaction is
formulated using a gauge invariant framework, loop effects generate an
effective $\bar{\chi}\chi h$ vertex and result in a scattering cross section
that is within reach of current or forthcoming experiments. We also consider
the case of inelastic dark matter, for which the tree-level direct detection
cross section is negligible when the inelastic $\chi_1 N \to \chi_2 N$ process
is kinematically suppressed. In this case, loop diagrams generate an
interaction with both initial and final $\chi_1$ states and hence permit
measurable, spin independent, $\chi_1 N \to \chi_1 N$ elastic scattering. As
such, we are able to probe parameter space that was previously considered
inaccessible to direct detection
| [
{
"created": "Mon, 5 Mar 2018 09:48:20 GMT",
"version": "v1"
}
] | 2018-08-22 | [
[
"Bell",
"Nicole F.",
""
],
[
"Busoni",
"Giorgio",
""
],
[
"Sanderson",
"Isaac W.",
""
]
] | We consider loop level contributions to dark matter scattering off nucleons in cases where the spin independent scattering cross section is absent or suppressed at tree level. In the case of a pseudoscalar interaction, for which the tree level cross section is both spin-dependent and suppressed by 4 powers of the exchanged momentum, we show that loop diagrams give rise to a non- zero spin independent cross section. Importantly, if the pseudoscalar interaction is formulated using a gauge invariant framework, loop effects generate an effective $\bar{\chi}\chi h$ vertex and result in a scattering cross section that is within reach of current or forthcoming experiments. We also consider the case of inelastic dark matter, for which the tree-level direct detection cross section is negligible when the inelastic $\chi_1 N \to \chi_2 N$ process is kinematically suppressed. In this case, loop diagrams generate an interaction with both initial and final $\chi_1$ states and hence permit measurable, spin independent, $\chi_1 N \to \chi_1 N$ elastic scattering. As such, we are able to probe parameter space that was previously considered inaccessible to direct detection |
hep-ph/9802411 | Andrei Belitsky | A.V. Belitsky, D. Mueller | Next-to-leading order evolution of twist-two conformal operators: The
abelian case | 29 pages, LaTeX, 3 figures, typos fixed | Nucl.Phys.B527:207-234,1998 | 10.1016/S0550-3213(98)00310-1 | null | hep-ph hep-th | null | We present the method, based on the use of the broken conformal Ward
identities, for the calculation of the anomalous dimensions of conformal
operators beyond the leading order of perturbation theory. By means of this
technique we find the complete set of two-loop corrections to the off-diagonal
elements of the anomalous dimension matrix (the diagonal ones are known from
deep inelastic scattering calculations) of the parity odd and even singlet
local operators in the Abelian gauge theory. We reconstruct corresponding
exclusive two-loop evolution kernels and give the reduction formulae for the
restoration of the diagonal part of the ER-BL kernels from the DGLAP splitting
functions.
| [
{
"created": "Tue, 24 Feb 1998 15:20:31 GMT",
"version": "v1"
},
{
"created": "Thu, 26 Feb 1998 12:03:39 GMT",
"version": "v2"
},
{
"created": "Mon, 20 Apr 1998 14:20:24 GMT",
"version": "v3"
}
] | 2014-11-17 | [
[
"Belitsky",
"A. V.",
""
],
[
"Mueller",
"D.",
""
]
] | We present the method, based on the use of the broken conformal Ward identities, for the calculation of the anomalous dimensions of conformal operators beyond the leading order of perturbation theory. By means of this technique we find the complete set of two-loop corrections to the off-diagonal elements of the anomalous dimension matrix (the diagonal ones are known from deep inelastic scattering calculations) of the parity odd and even singlet local operators in the Abelian gauge theory. We reconstruct corresponding exclusive two-loop evolution kernels and give the reduction formulae for the restoration of the diagonal part of the ER-BL kernels from the DGLAP splitting functions. |
hep-ph/9709449 | Peter Arnold | Peter Arnold and Laurence G. Yaffe | Effective theories for real-time correlations in hot plasmas | 28 pages, Latex, uses revtex, epsf macro packages [Revised version: t
-> sqrt{t} in a few typos on p. 10.] | Phys.Rev.D57:1178-1192,1998 | 10.1103/PhysRevD.57.1178 | UW/PT-97-22 | hep-ph | null | We discuss the sequence of effective theories needed to understand the
qualitative, and quantitative, behavior of real-time correlators < A(t) A(0) >
in ultra-relativistic plasmas. We analyze in detail the case where A is a
gauge-invariant conserved current. This case is of interest because it includes
a correlation recently measured in lattice simulations of classical, hot,
SU(2)-Higgs gauge theory. We find that simple perturbation theory, free kinetic
theory, linearized kinetic theory, and hydrodynamics are all needed to
understand the correlation for different ranges of time. We emphasize how
correlations generically have power-law decays at very large times due to
non-linear couplings to long-lived hydrodynamic modes.
| [
{
"created": "Wed, 24 Sep 1997 23:10:47 GMT",
"version": "v1"
},
{
"created": "Thu, 25 Sep 1997 20:08:37 GMT",
"version": "v2"
}
] | 2010-02-16 | [
[
"Arnold",
"Peter",
""
],
[
"Yaffe",
"Laurence G.",
""
]
] | We discuss the sequence of effective theories needed to understand the qualitative, and quantitative, behavior of real-time correlators < A(t) A(0) > in ultra-relativistic plasmas. We analyze in detail the case where A is a gauge-invariant conserved current. This case is of interest because it includes a correlation recently measured in lattice simulations of classical, hot, SU(2)-Higgs gauge theory. We find that simple perturbation theory, free kinetic theory, linearized kinetic theory, and hydrodynamics are all needed to understand the correlation for different ranges of time. We emphasize how correlations generically have power-law decays at very large times due to non-linear couplings to long-lived hydrodynamic modes. |
1708.06764 | Camilo Garcia-Cely | Xiaoyong Chu and Camilo Garcia-Cely | Self-interacting Spin-2 Dark Matter | Minor changes. It matches the published version | Phys. Rev. D 96, 103519 (2017) | 10.1103/PhysRevD.96.103519 | null | hep-ph gr-qc | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Recent developments in bigravity allow one to construct consistent theories
of interacting spin-2 particles that are free of ghosts. In this framework, we
propose an elementary spin-2 dark matter candidate with a mass well below the
TeV scale. We show that, in a certain regime where the interactions induced by
the spin-2 fields do not lead to large departures from the predictions of
general relativity, such a light dark matter particle typically self-interacts
and undergoes self-annihilations via 3-to-2 processes. We discuss its
production mechanisms and also identify the regions of the parameter space
where self-interactions can alleviate the discrepancies at small scales between
the predictions of the collisionless dark matter paradigm and cosmological
N-body simulations.
| [
{
"created": "Tue, 22 Aug 2017 18:00:17 GMT",
"version": "v1"
},
{
"created": "Fri, 24 Nov 2017 14:07:58 GMT",
"version": "v2"
}
] | 2017-11-27 | [
[
"Chu",
"Xiaoyong",
""
],
[
"Garcia-Cely",
"Camilo",
""
]
] | Recent developments in bigravity allow one to construct consistent theories of interacting spin-2 particles that are free of ghosts. In this framework, we propose an elementary spin-2 dark matter candidate with a mass well below the TeV scale. We show that, in a certain regime where the interactions induced by the spin-2 fields do not lead to large departures from the predictions of general relativity, such a light dark matter particle typically self-interacts and undergoes self-annihilations via 3-to-2 processes. We discuss its production mechanisms and also identify the regions of the parameter space where self-interactions can alleviate the discrepancies at small scales between the predictions of the collisionless dark matter paradigm and cosmological N-body simulations. |
2405.06019 | Evgeny Akhmedov | Evgeny Akhmedov and Maxim Pospelov | BBN catalysis by doubly charged particles | LaTeX 24 pages, 1 table, 4 figures. v2: minor typo corrected. v3:
minor textual changes. Version to be published in JCAP | null | null | null | hep-ph astro-ph.CO hep-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider primordial nucleosynthesis in the presence of hypothetical
quasi-stable doubly charged particles. Existence of $X^{--}$ with macroscopic
lifetimes will lead to the formation of its bound states with $^4$He and other
light elements, significantly facilitating the subsequent formation of lithium
nuclei. From observational constraints on maximum allowable amount of lithium,
that we update in this work, we derive strong constraints on the abundance and
lifetime of $X^{--}$. In a likely cosmological freeze-out scenario with
temperatures initially exceeding the mass of $X^{--}$, the BBN constrains the
lifetime of these particles to be less than about 100 seconds. For
parametrically long lifetimes, lithium abundance data constrain $X^{--}$
abundance to be less than $10^{-9}$ relative to protons, regardless of whether
these particles decay or remain stable. Stable particles could saturate the
dark matter density only if their mass is comparable to or in excess of
$10^{10}$ GeV, and most of $X^{--}$ will be found in bound states with
beryllium nuclei, so that chemically they would appear as abnormally heavy
helium isotopes.
| [
{
"created": "Thu, 9 May 2024 18:00:03 GMT",
"version": "v1"
},
{
"created": "Mon, 20 May 2024 13:09:00 GMT",
"version": "v2"
},
{
"created": "Tue, 30 Jul 2024 08:20:53 GMT",
"version": "v3"
}
] | 2024-07-31 | [
[
"Akhmedov",
"Evgeny",
""
],
[
"Pospelov",
"Maxim",
""
]
] | We consider primordial nucleosynthesis in the presence of hypothetical quasi-stable doubly charged particles. Existence of $X^{--}$ with macroscopic lifetimes will lead to the formation of its bound states with $^4$He and other light elements, significantly facilitating the subsequent formation of lithium nuclei. From observational constraints on maximum allowable amount of lithium, that we update in this work, we derive strong constraints on the abundance and lifetime of $X^{--}$. In a likely cosmological freeze-out scenario with temperatures initially exceeding the mass of $X^{--}$, the BBN constrains the lifetime of these particles to be less than about 100 seconds. For parametrically long lifetimes, lithium abundance data constrain $X^{--}$ abundance to be less than $10^{-9}$ relative to protons, regardless of whether these particles decay or remain stable. Stable particles could saturate the dark matter density only if their mass is comparable to or in excess of $10^{10}$ GeV, and most of $X^{--}$ will be found in bound states with beryllium nuclei, so that chemically they would appear as abnormally heavy helium isotopes. |
hep-ph/0205207 | Michel Sorel | Michel Sorel | Supernova Neutrinos, LSND and MiniBooNE | 6 pages, 6 figures. To appear in the proceedings of 37th Rencontres
de Moriond on Electroweak Interactions and Unified Theories, Les Arcs,
France, 9-16 Mar 2002 | null | null | null | hep-ph | null | The unique constraints on neutrino oscillations which can be obtained by
measuring the energy spectrum of supernova $\bar{\nu}_e$'s are first discussed.
The focus is on 4-neutrino mass and mixing models capable of explaining the
LSND evidence of $\bar{\nu}_{\mu}\to \bar{\nu}_e$ oscillations.
The potential of the Fermilab neutrino detector MiniBooNE to observe
supernova neutrinos is then addressed, and a general description of the
detector is given. As of May, 2002, the MiniBooNE detector is fully
operational.
| [
{
"created": "Sun, 19 May 2002 17:28:39 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Sorel",
"Michel",
""
]
] | The unique constraints on neutrino oscillations which can be obtained by measuring the energy spectrum of supernova $\bar{\nu}_e$'s are first discussed. The focus is on 4-neutrino mass and mixing models capable of explaining the LSND evidence of $\bar{\nu}_{\mu}\to \bar{\nu}_e$ oscillations. The potential of the Fermilab neutrino detector MiniBooNE to observe supernova neutrinos is then addressed, and a general description of the detector is given. As of May, 2002, the MiniBooNE detector is fully operational. |
1510.03175 | Wei-Hong Liang | Wei-Hong Liang, Ju-Jun Xie, E. Oset | $\bar B^0$, $B^-$ and $\bar B^0_s$ decays into $J/\psi$ and $K \bar K$
or $\pi \eta$ | 12 pages, 6 figures; v2: discussion added, references added, final
version published in EPJC | null | 10.1140/epjc/s10052-015-3827-5 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the $\bar B^0_s \to J/\psi K^+ K^-$, $\bar B^0 \to J/\psi K^+ K^-$,
$B^- \to J/\psi K^0 K^-$, $\bar B^0 \to J/\psi \pi^0 \eta$ and $B^- \to J/\psi
\pi^- \eta$ decays and compare their mass distributions with those obtained for
the $\bar B^0_s \to J/\psi \pi^+ \pi^-$ and $\bar B^0 \to J/\psi \pi^+ \pi^-$.
The approach followed consist in a factorization of the weak part and the
hadronization part into a factor which is common to all the processes. Then
what makes the reactions different are some trivial Cabibbo-Kobayashi-Maskawa
matrix elements and the weight by which the different pairs of mesons appear in
a primary step plus their final state interaction. These elements are part of
the theory and thus, up to a global normalization factor, all the invariant
mass distributions are predicted with no free parameters. Comparison is made
with the limited experimental information available. Further comparison of
these results with coming LHCb measurements will be very valuable to make
progress in our understanding of the meson-meson interaction and the nature of
the low lying scalar meson resonances, $f_0(500), f_0(980)$ and $a_0(980)$.
| [
{
"created": "Mon, 12 Oct 2015 08:06:22 GMT",
"version": "v1"
},
{
"created": "Tue, 5 Jan 2016 13:50:53 GMT",
"version": "v2"
}
] | 2016-01-27 | [
[
"Liang",
"Wei-Hong",
""
],
[
"Xie",
"Ju-Jun",
""
],
[
"Oset",
"E.",
""
]
] | We study the $\bar B^0_s \to J/\psi K^+ K^-$, $\bar B^0 \to J/\psi K^+ K^-$, $B^- \to J/\psi K^0 K^-$, $\bar B^0 \to J/\psi \pi^0 \eta$ and $B^- \to J/\psi \pi^- \eta$ decays and compare their mass distributions with those obtained for the $\bar B^0_s \to J/\psi \pi^+ \pi^-$ and $\bar B^0 \to J/\psi \pi^+ \pi^-$. The approach followed consist in a factorization of the weak part and the hadronization part into a factor which is common to all the processes. Then what makes the reactions different are some trivial Cabibbo-Kobayashi-Maskawa matrix elements and the weight by which the different pairs of mesons appear in a primary step plus their final state interaction. These elements are part of the theory and thus, up to a global normalization factor, all the invariant mass distributions are predicted with no free parameters. Comparison is made with the limited experimental information available. Further comparison of these results with coming LHCb measurements will be very valuable to make progress in our understanding of the meson-meson interaction and the nature of the low lying scalar meson resonances, $f_0(500), f_0(980)$ and $a_0(980)$. |
hep-ph/0310092 | Bo-Qiang Ma | Jian Su, Bo-Qiang Ma | Applicability of Perturbative QCD to Pion Virtual Compton Scattering | 13 Latex pages, 10 figures, to appear in PLB | Phys.Lett. B574 (2003) 217-224 | 10.1016/j.physletb.2003.09.003 | null | hep-ph hep-ex | null | We study explicitly the applicability of perturbative QCD (pQCD) to the pion
virtual Compton scattering. It is found that there are central-region
singularities introduced by the QCD running coupling constant, in addition to
the end-point singularities generally existed in other exclusive processes such
as the pion form factor. We introduce a simple technique to evaluate the
contributions from these singularities, so that we can arrive at a judgement
that these contributions will be unharmful to the applicability of pQCD at
certain energy scale, i.e., the ``work point'' which is defined to determine
when pQCD is applicable to exclusive processes. The applicability of pQCD for
different pion distribution amplitudes are explored in detail. We show that
pQCD begins to work at 10 ${GeV}^2$. If we relax our constraint to a weak
sense, the work point may be as low as 4 ${GeV}^2$.
| [
{
"created": "Tue, 7 Oct 2003 23:53:03 GMT",
"version": "v1"
}
] | 2015-06-25 | [
[
"Su",
"Jian",
""
],
[
"Ma",
"Bo-Qiang",
""
]
] | We study explicitly the applicability of perturbative QCD (pQCD) to the pion virtual Compton scattering. It is found that there are central-region singularities introduced by the QCD running coupling constant, in addition to the end-point singularities generally existed in other exclusive processes such as the pion form factor. We introduce a simple technique to evaluate the contributions from these singularities, so that we can arrive at a judgement that these contributions will be unharmful to the applicability of pQCD at certain energy scale, i.e., the ``work point'' which is defined to determine when pQCD is applicable to exclusive processes. The applicability of pQCD for different pion distribution amplitudes are explored in detail. We show that pQCD begins to work at 10 ${GeV}^2$. If we relax our constraint to a weak sense, the work point may be as low as 4 ${GeV}^2$. |
2103.05005 | Isaac Wang | Kohei Fujikura, Keisuke Harigaya, Yuichiro Nakai, Isaac R. Wang | Electroweak-like Baryogenesis with New Chiral Matter | 61 pages, 9 figures | null | 10.1007/JHEP07(2021)224 | null | hep-ph astro-ph.CO | http://creativecommons.org/licenses/by/4.0/ | We propose a framework where a phase transition associated with a gauge
symmetry breaking that occurs (not far) above the electroweak scale sets a
stage for baryogenesis similar to the electroweak baryogenesis in the Standard
Model. A concrete realization utilizes the breaking of $SU(2)_R \times U(1)_X
\rightarrow U(1)_Y$. New chiral fermions charged under the extended gauge
symmetry have nonzero lepton numbers, which makes the $B-L$ symmetry anomalous.
The new lepton sector contains a large flavor-dependent CP violation, similar
to the Cabibbo-Kobayashi-Maskawa phase, without inducing sizable electric
dipole moments of the Standard Model particles. A bubble wall dynamics
associated with the first-order phase transition and $SU(2)_R$ sphaleron
processes generate a lepton asymmetry, which is transferred into a baryon
asymmetry via the ordinary electroweak sphaleron process. Unlike the Standard
Model electroweak baryogenesis, the new phase transition can be of the strong
first order and the new CP violation is not significantly suppressed by Yukawa
couplings, so that the observed asymmetry can be produced. The model can be
probed by collider searches for new particles and the observation of
gravitational waves. One of the new leptons becomes a dark matter candidate.
The model can be also embedded into a left-right symmetric theory to solve the
strong CP problem.
| [
{
"created": "Mon, 8 Mar 2021 19:00:02 GMT",
"version": "v1"
},
{
"created": "Sun, 1 Aug 2021 20:36:07 GMT",
"version": "v2"
},
{
"created": "Thu, 23 Dec 2021 00:18:05 GMT",
"version": "v3"
},
{
"created": "Sun, 9 Jan 2022 04:11:39 GMT",
"version": "v4"
}
] | 2022-01-11 | [
[
"Fujikura",
"Kohei",
""
],
[
"Harigaya",
"Keisuke",
""
],
[
"Nakai",
"Yuichiro",
""
],
[
"Wang",
"Isaac R.",
""
]
] | We propose a framework where a phase transition associated with a gauge symmetry breaking that occurs (not far) above the electroweak scale sets a stage for baryogenesis similar to the electroweak baryogenesis in the Standard Model. A concrete realization utilizes the breaking of $SU(2)_R \times U(1)_X \rightarrow U(1)_Y$. New chiral fermions charged under the extended gauge symmetry have nonzero lepton numbers, which makes the $B-L$ symmetry anomalous. The new lepton sector contains a large flavor-dependent CP violation, similar to the Cabibbo-Kobayashi-Maskawa phase, without inducing sizable electric dipole moments of the Standard Model particles. A bubble wall dynamics associated with the first-order phase transition and $SU(2)_R$ sphaleron processes generate a lepton asymmetry, which is transferred into a baryon asymmetry via the ordinary electroweak sphaleron process. Unlike the Standard Model electroweak baryogenesis, the new phase transition can be of the strong first order and the new CP violation is not significantly suppressed by Yukawa couplings, so that the observed asymmetry can be produced. The model can be probed by collider searches for new particles and the observation of gravitational waves. One of the new leptons becomes a dark matter candidate. The model can be also embedded into a left-right symmetric theory to solve the strong CP problem. |
1111.2589 | Bernd Jantzen | Bernd Jantzen | Foundation and generalization of the expansion by regions | 84 pages; v2: comment on scaleless integrals added to conclusions,
version published in JHEP | JHEP 1112:076,2011 | 10.1007/JHEP12(2011)076 | TTK-11-53; SFB/CPP-11-61 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The "expansion by regions" is a method of asymptotic expansion developed by
Beneke and Smirnov in 1997. It expands the integrand according to the scaling
prescriptions of a set of regions and integrates all expanded terms over the
whole integration domain. This method has been applied successfully to many
complicated loop integrals, but a general proof for its correctness has still
been missing. This paper shows how the expansion by regions manages to
reproduce the exact result correctly in an expanded form and clarifies the
conditions on the choice and completeness of the considered regions. A
generalized expression for the full result is presented that involves
additional overlap contributions. These extra pieces normally yield scaleless
integrals which are consistently set to zero, but they may be needed depending
on the choice of the regularization scheme. While the main proofs and formulae
are presented in a general and concise form, a large portion of the paper is
filled with simple, pedagogical one-loop examples which illustrate the
peculiarities of the expansion by regions, explain its application and show how
to evaluate contributions within this method.
| [
{
"created": "Thu, 10 Nov 2011 20:41:21 GMT",
"version": "v1"
},
{
"created": "Thu, 22 Dec 2011 20:31:16 GMT",
"version": "v2"
}
] | 2011-12-23 | [
[
"Jantzen",
"Bernd",
""
]
] | The "expansion by regions" is a method of asymptotic expansion developed by Beneke and Smirnov in 1997. It expands the integrand according to the scaling prescriptions of a set of regions and integrates all expanded terms over the whole integration domain. This method has been applied successfully to many complicated loop integrals, but a general proof for its correctness has still been missing. This paper shows how the expansion by regions manages to reproduce the exact result correctly in an expanded form and clarifies the conditions on the choice and completeness of the considered regions. A generalized expression for the full result is presented that involves additional overlap contributions. These extra pieces normally yield scaleless integrals which are consistently set to zero, but they may be needed depending on the choice of the regularization scheme. While the main proofs and formulae are presented in a general and concise form, a large portion of the paper is filled with simple, pedagogical one-loop examples which illustrate the peculiarities of the expansion by regions, explain its application and show how to evaluate contributions within this method. |
2101.08263 | Benjamin Lehmann | Yonit Hochberg, Yonatan Kahn, Noah Kurinsky, Benjamin V. Lehmann, To
Chin Yu and Karl K. Berggren | Determining Dark Matter-Electron Scattering Rates from the Dielectric
Function | 5 pages + references, 2 figures. Includes supplementary material (13
pages, 6 figures). Fixed typo in eq. (S.16) | Phys. Rev. Lett. 127, 151802 (2021) | 10.1103/PhysRevLett.127.151802 | null | hep-ph cond-mat.mtrl-sci hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We show that the rate for dark matter-electron scattering in an arbitrary
material is determined by an experimentally measurable quantity, the complex
dielectric function, for any dark matter interaction that couples to electron
density. This formulation automatically includes many-body effects, eliminates
all systematic theoretical uncertainties on the electronic wavefunctions, and
allows a direct calibration of the spectrum by electromagnetic probes such as
infrared spectroscopy, X-ray scattering, and electron energy-loss spectroscopy
(EELS). Our formalism applies for several common benchmark models, including
spin-independent interactions through scalar and vector mediators of arbitrary
mass. We discuss the consequences for standard semiconductor and superconductor
targets, and find that the true reach of superconductor detectors for light
mediators exceeds previous estimates by several orders of magnitude, with
further enhancements possible due to the low-energy tail of the plasmon. Using
a heavy-fermion superconductor as an example, we show how our formulation
allows a rapid and systematic investigation of novel electron scattering
targets.
| [
{
"created": "Wed, 20 Jan 2021 19:00:00 GMT",
"version": "v1"
},
{
"created": "Mon, 11 Oct 2021 17:47:29 GMT",
"version": "v2"
},
{
"created": "Wed, 14 Dec 2022 21:45:16 GMT",
"version": "v3"
}
] | 2022-12-16 | [
[
"Hochberg",
"Yonit",
""
],
[
"Kahn",
"Yonatan",
""
],
[
"Kurinsky",
"Noah",
""
],
[
"Lehmann",
"Benjamin V.",
""
],
[
"Yu",
"To Chin",
""
],
[
"Berggren",
"Karl K.",
""
]
] | We show that the rate for dark matter-electron scattering in an arbitrary material is determined by an experimentally measurable quantity, the complex dielectric function, for any dark matter interaction that couples to electron density. This formulation automatically includes many-body effects, eliminates all systematic theoretical uncertainties on the electronic wavefunctions, and allows a direct calibration of the spectrum by electromagnetic probes such as infrared spectroscopy, X-ray scattering, and electron energy-loss spectroscopy (EELS). Our formalism applies for several common benchmark models, including spin-independent interactions through scalar and vector mediators of arbitrary mass. We discuss the consequences for standard semiconductor and superconductor targets, and find that the true reach of superconductor detectors for light mediators exceeds previous estimates by several orders of magnitude, with further enhancements possible due to the low-energy tail of the plasmon. Using a heavy-fermion superconductor as an example, we show how our formulation allows a rapid and systematic investigation of novel electron scattering targets. |
1904.04252 | Marat Siddikov Ilfatovich | Marat Siddikov, Ivan Schmidt | Generalized Parton Distributions from charged current meson production | 16 pages, 5 Figures. Extension of the approach developed in
arXiv:1709.01405 for $\rho$-mesons | Phys. Rev. D 99, 116005 (2019) | 10.1103/PhysRevD.99.116005 | USM-TH-360 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper we prove that the simultaneous study of both $\rho$- and
$\pi$-meson production by charged currents in Bjorken kinematics allows for a
very clean extraction of the leading twist Generalized Parton Distributions of
the target, with inherent control of the contribution of higher-twist
corrections. Also, it might provide target-independent constraints on the
distribution amplitudes of the produced mesons. We expect that such processes
might be studied either in neutrino-induced or in electron-induced processes.
According to our numerical estimates, the cross-sections of these processes are
within the reach of JLab and EIC experiments.
| [
{
"created": "Mon, 8 Apr 2019 14:54:51 GMT",
"version": "v1"
}
] | 2019-06-19 | [
[
"Siddikov",
"Marat",
""
],
[
"Schmidt",
"Ivan",
""
]
] | In this paper we prove that the simultaneous study of both $\rho$- and $\pi$-meson production by charged currents in Bjorken kinematics allows for a very clean extraction of the leading twist Generalized Parton Distributions of the target, with inherent control of the contribution of higher-twist corrections. Also, it might provide target-independent constraints on the distribution amplitudes of the produced mesons. We expect that such processes might be studied either in neutrino-induced or in electron-induced processes. According to our numerical estimates, the cross-sections of these processes are within the reach of JLab and EIC experiments. |
hep-ph/9901210 | Morimitsu Tanimoto | Morimitsu Tanimoto | Quark-Lepton Mass Matrices with $U(1)\times Z_2 \times Z_2'$ Flavor
Symmetry | 19 pages, LaTex file, no figures | Phys.Lett.B456:220-231,1999 | 10.1016/S0370-2693(99)00467-0 | EHU-99-1 | hep-ph | null | The U(1) flavor symmetry explains the large mixing of neutrinos while it
leads to the unique texture for the quark mass matrices. It is remarked that
U(1) symmetric mass matrices have the phenomenological defects. In the quark
sector, the mixing $V_{ub}$ is predicted to be large compared with the expected
value $\l^4$ at the GUT scale. In the lepton sector, U(1) charges, which give a
large mixing in the neutrino sector, also lead to the large one in the charged
lepton sector. In the viewpoint of the flavor symmetry, this is an unpleasant
feature because the neutrino mass hierarchy is determined only by unknown
coefficients of ${\cal O}(1)$, and the near-maximal flavor mixing is not
guaranteed in the case of both large angle rotations. These defects disappear
by introducing additional discrete symmetries $Z_2\times Z_2'$. The $U(1)\times
Z_2\times Z_2'$ quark-lepton mass matrices are presented by taking account of
the recent data of atmospheric neutrinos and solar neutrinos.
| [
{
"created": "Mon, 4 Jan 1999 06:21:11 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Tanimoto",
"Morimitsu",
""
]
] | The U(1) flavor symmetry explains the large mixing of neutrinos while it leads to the unique texture for the quark mass matrices. It is remarked that U(1) symmetric mass matrices have the phenomenological defects. In the quark sector, the mixing $V_{ub}$ is predicted to be large compared with the expected value $\l^4$ at the GUT scale. In the lepton sector, U(1) charges, which give a large mixing in the neutrino sector, also lead to the large one in the charged lepton sector. In the viewpoint of the flavor symmetry, this is an unpleasant feature because the neutrino mass hierarchy is determined only by unknown coefficients of ${\cal O}(1)$, and the near-maximal flavor mixing is not guaranteed in the case of both large angle rotations. These defects disappear by introducing additional discrete symmetries $Z_2\times Z_2'$. The $U(1)\times Z_2\times Z_2'$ quark-lepton mass matrices are presented by taking account of the recent data of atmospheric neutrinos and solar neutrinos. |
1911.09348 | Ya Li | Ya Li, Da-Cheng Yan, Zhou Rui, Zhen-Jun Xiao | $S$, $P$ and $D$-wave resonance contributions to $B_{(s)} \to
\eta_c(1S,2S) K\pi$ decays in the perturbative QCD approach | 18 pages, 3 figures | Phys. Rev. D 101, 016015 (2020) | 10.1103/PhysRevD.101.016015 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this work, we analyze the three-body $B_{(s)} \to \eta_c(1S,2S) K \pi$
decays within the framework of the perturbative QCD approach (PQCD) under the
quasi-two-body approximation, where the kaon-pion invariant mass spectra are
dominated by the
$K_0^*(1430)^0,K_0^*(1950)^0,K^*(892)^0,K^*(1410)^0,K^*(1680)^0$ and
$K_2^*(1430)^0$ resonances. The time-like form factors are adopted to
parametrize the corresponding $S$, $P$, $D$-wave kaon-pion distribution
amplitudes for the concerned decay modes, which describe the final-state
interactions between the kaon and pion in the resonant region. The $K\pi$
$S$-wave component at low $K\pi$ mass is described by the LASS line shape,
while the time-like form factors of other resonances are modeled by the
relativistic Breit-Wigner function. We find the following main points: (a) the
PQCD predictions of the branching ratios for most considered $B \to
\eta_c(1S)(K^{*0}\to )K^+\pi^-$ decays agree well with the currently available
data within errors; (b) for ${\cal B}(B^0 \to \eta_c (K_0^*(1430)\to
)K^+\pi^-)$ and ${\cal B}(B^0 \to \eta_c K^+\pi^-({\rm NR}))$ (here NR means
nonresonant), our predictions of the branching ratios are a bit smaller than
the measured ones; and (c) the PQCD results for the $D$-wave contributions
considered in this work can be tested once the precise data from the future
LHCb and Belle-II experiments are available.
| [
{
"created": "Thu, 21 Nov 2019 08:50:16 GMT",
"version": "v1"
},
{
"created": "Thu, 30 Jan 2020 07:42:00 GMT",
"version": "v2"
},
{
"created": "Mon, 20 Apr 2020 03:39:17 GMT",
"version": "v3"
}
] | 2020-04-21 | [
[
"Li",
"Ya",
""
],
[
"Yan",
"Da-Cheng",
""
],
[
"Rui",
"Zhou",
""
],
[
"Xiao",
"Zhen-Jun",
""
]
] | In this work, we analyze the three-body $B_{(s)} \to \eta_c(1S,2S) K \pi$ decays within the framework of the perturbative QCD approach (PQCD) under the quasi-two-body approximation, where the kaon-pion invariant mass spectra are dominated by the $K_0^*(1430)^0,K_0^*(1950)^0,K^*(892)^0,K^*(1410)^0,K^*(1680)^0$ and $K_2^*(1430)^0$ resonances. The time-like form factors are adopted to parametrize the corresponding $S$, $P$, $D$-wave kaon-pion distribution amplitudes for the concerned decay modes, which describe the final-state interactions between the kaon and pion in the resonant region. The $K\pi$ $S$-wave component at low $K\pi$ mass is described by the LASS line shape, while the time-like form factors of other resonances are modeled by the relativistic Breit-Wigner function. We find the following main points: (a) the PQCD predictions of the branching ratios for most considered $B \to \eta_c(1S)(K^{*0}\to )K^+\pi^-$ decays agree well with the currently available data within errors; (b) for ${\cal B}(B^0 \to \eta_c (K_0^*(1430)\to )K^+\pi^-)$ and ${\cal B}(B^0 \to \eta_c K^+\pi^-({\rm NR}))$ (here NR means nonresonant), our predictions of the branching ratios are a bit smaller than the measured ones; and (c) the PQCD results for the $D$-wave contributions considered in this work can be tested once the precise data from the future LHCb and Belle-II experiments are available. |
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