id stringlengths 9 14 | submitter stringlengths 1 56 ⌀ | authors stringlengths 5 7.68k | title stringlengths 3 299 | comments stringlengths 1 1.15k ⌀ | journal-ref stringlengths 9 298 ⌀ | doi stringlengths 12 97 ⌀ | report-no stringlengths 3 341 ⌀ | categories stringclasses 869 values | license stringclasses 9 values | orig_abstract stringlengths 16 2.44k | versions listlengths 1 39 | update_date stringlengths 10 10 | authors_parsed listlengths 1 565 | abstract stringlengths 13 2.44k |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1906.09071 | Stanislaw Jadach | S. Jadach, W. P{\l}aczek and M. Skrzypek | QED Exponentiation for quasi-stable charged particles: the $e^-e^+\to
W^-W^+$ process | Short version has appeared in conference materials, Symmetry 11, 1389
(2019) | null | 10.1140/epjc/s10052-020-8034-3 | IFJPAN-IV-2019-5 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | All real and virtual infrared singularities in the standard analysis of the
perturbative Quantum Electrodynamics (like that of Yennie-Frautschi-Suura) are
associated with photon emissions from the external legs in the scattering
process. External particles are stable, with the zero decay width. Such
singularities are well understood at any perturbative order and are resummed.
The case of production and decay of the semi-stable {\em neutral} particles
like $Z$ boson or $\tau$ lepton, with the narrow decay width, $\Gamma/M \ll 1$,
is also well understood at any perturbative order and soft photon resummation
can be done. For the absent or loose upper cut-off on the total photon energy
$\omega$ the production and decay process of the semi-stable (neutral)
particles decouples approximately and can be considered quasi-independently. In
particular soft photon resummation can be done separately for the production
and decay process treating semi-stable (neutral) particle as stable. So far,
consistent treatment of the soft photon resummation for semi-stable {\em
charged} particles like $W^\pm$ boson is not available in the literature and
the aim of this work is to present a solution for this problem. Generally, it
should be feasible because the underlying physics is the same as in the case of
the neutral semi-stable resonances -- in the limit $\Gamma/M \ll 1$ production
and decay processes for charged particles also necessarily decouple due to long
lifetime of the particles. The technical problems to be solved in this work are
related to the fact that semi-stable charged particle are able to emit photons.
| [
{
"created": "Fri, 21 Jun 2019 11:17:53 GMT",
"version": "v1"
},
{
"created": "Wed, 11 Mar 2020 15:22:37 GMT",
"version": "v2"
}
] | 2020-06-24 | [
[
"Jadach",
"S.",
""
],
[
"Płaczek",
"W.",
""
],
[
"Skrzypek",
"M.",
""
]
] | All real and virtual infrared singularities in the standard analysis of the perturbative Quantum Electrodynamics (like that of Yennie-Frautschi-Suura) are associated with photon emissions from the external legs in the scattering process. External particles are stable, with the zero decay width. Such singularities are well understood at any perturbative order and are resummed. The case of production and decay of the semi-stable {\em neutral} particles like $Z$ boson or $\tau$ lepton, with the narrow decay width, $\Gamma/M \ll 1$, is also well understood at any perturbative order and soft photon resummation can be done. For the absent or loose upper cut-off on the total photon energy $\omega$ the production and decay process of the semi-stable (neutral) particles decouples approximately and can be considered quasi-independently. In particular soft photon resummation can be done separately for the production and decay process treating semi-stable (neutral) particle as stable. So far, consistent treatment of the soft photon resummation for semi-stable {\em charged} particles like $W^\pm$ boson is not available in the literature and the aim of this work is to present a solution for this problem. Generally, it should be feasible because the underlying physics is the same as in the case of the neutral semi-stable resonances -- in the limit $\Gamma/M \ll 1$ production and decay processes for charged particles also necessarily decouple due to long lifetime of the particles. The technical problems to be solved in this work are related to the fact that semi-stable charged particle are able to emit photons. |
hep-ph/9509306 | J. W. F. Valle | Jose W. F. Valle | Neutrino-less Double Beta Decay and Physics Beyond the Standard Model | invited talk at Workshop on "Double-beta decay and related topics",
Trento, April 1995, proceedings to be published, latex, 22 pages, 10 figures
not included, file caption.sty appended at the end | null | null | FTUV/95-44 IFIC/95-46 | hep-ph | null | A brief sketch is given of the present observational status and future
prospects of the physics of neutrino mass, including a survey of the various
theoretical schemes of neutrino mass generation. Emphasis is given to those
which are motivated by present experimental hints from solar and atmospheric
neutrinos, as well as from cosmological data related to the dark matter
question. The conceptual importance of neutrino-less double beta decay as a
distinctive signature of the Majorana character of neutrinos is stressed.
Barring accidental cancellations this process gives the strongest laboratory
constraint on neutrino mass.
| [
{
"created": "Fri, 15 Sep 1995 18:01:07 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Valle",
"Jose W. F.",
""
]
] | A brief sketch is given of the present observational status and future prospects of the physics of neutrino mass, including a survey of the various theoretical schemes of neutrino mass generation. Emphasis is given to those which are motivated by present experimental hints from solar and atmospheric neutrinos, as well as from cosmological data related to the dark matter question. The conceptual importance of neutrino-less double beta decay as a distinctive signature of the Majorana character of neutrinos is stressed. Barring accidental cancellations this process gives the strongest laboratory constraint on neutrino mass. |
1912.11055 | Fady Bishara | Fady Bishara and Marc Montull | (Machine) Learning amplitudes for faster event generation | 5+2 pages, 5 figures, and 2 tables; fixed minor typos, merged two
figures, and updated acknowledgements of support | null | null | DESY 19-232 | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We propose to replace the exact amplitudes used in MC event generators for
trained Machine Learning regressors, with the aim of speeding up the evaluation
of {\it slow} amplitudes. As a proof of concept, we study the process $gg \to
ZZ$ whose LO amplitude is loop induced. We show that gradient boosting machines
like $\texttt{XGBoost}$ can predict the fully differential distributions with
errors below $0.1 \%$, and with prediction times $\mathcal{O}(10^3)$ faster
than the evaluation of the exact function. This is achieved with training times
$\sim 7$ minutes and regressors of size $\lesssim 30$~Mb. These results suggest
a possible new avenue to speed up MC event generators.
| [
{
"created": "Mon, 23 Dec 2019 19:00:04 GMT",
"version": "v1"
},
{
"created": "Wed, 29 Jul 2020 14:54:40 GMT",
"version": "v2"
}
] | 2020-07-30 | [
[
"Bishara",
"Fady",
""
],
[
"Montull",
"Marc",
""
]
] | We propose to replace the exact amplitudes used in MC event generators for trained Machine Learning regressors, with the aim of speeding up the evaluation of {\it slow} amplitudes. As a proof of concept, we study the process $gg \to ZZ$ whose LO amplitude is loop induced. We show that gradient boosting machines like $\texttt{XGBoost}$ can predict the fully differential distributions with errors below $0.1 \%$, and with prediction times $\mathcal{O}(10^3)$ faster than the evaluation of the exact function. This is achieved with training times $\sim 7$ minutes and regressors of size $\lesssim 30$~Mb. These results suggest a possible new avenue to speed up MC event generators. |
hep-ph/0603114 | Marco Ciuchini | M. Ciuchini, L. Silvestrini | Upper bounds on SUSY contributions to b to s transitions from B_s -
B_sbar mixing | 4 pages, 4 figures; v2: CDF measurement included | Phys.Rev.Lett. 97 (2006) 021803 | 10.1103/PhysRevLett.97.021803 | null | hep-ph | null | We study the constraints on supersymmetric contributions to b to s
transitions from the recent allowed range and measurement of Bs-Bsbar mixing
obtained by the D0 and CDF collaborations at the Tevatron. We compute the upper
bounds on the relevant off-diagonal squark mass terms and compare them with the
bounds coming from Delta F=1 decays. We find that the constraints on
chirality-flipping mass insertions are unaffected. Conversely, the measurement
of Bs-Bsbar mixing is effective in constraining chirality-conserving mass
insertions, and it has striking effects in the case in which left- and
right-handed insertions have similar size. Finally, we discuss the phase of the
Bs-Bsbar mixing amplitude in the presence of SUSY contributions.
| [
{
"created": "Wed, 15 Mar 2006 17:21:35 GMT",
"version": "v1"
},
{
"created": "Fri, 19 May 2006 14:20:04 GMT",
"version": "v2"
}
] | 2009-11-11 | [
[
"Ciuchini",
"M.",
""
],
[
"Silvestrini",
"L.",
""
]
] | We study the constraints on supersymmetric contributions to b to s transitions from the recent allowed range and measurement of Bs-Bsbar mixing obtained by the D0 and CDF collaborations at the Tevatron. We compute the upper bounds on the relevant off-diagonal squark mass terms and compare them with the bounds coming from Delta F=1 decays. We find that the constraints on chirality-flipping mass insertions are unaffected. Conversely, the measurement of Bs-Bsbar mixing is effective in constraining chirality-conserving mass insertions, and it has striking effects in the case in which left- and right-handed insertions have similar size. Finally, we discuss the phase of the Bs-Bsbar mixing amplitude in the presence of SUSY contributions. |
hep-ph/0701230 | Simon Turbide | Simon Turbide and Charles Gale | High momentum lepton pairs from jet-plasma interactions | Parallel talk given at QM2006, Shanghai November 2006. 4 pages, 3
figures | J.Phys.G34:S1019-1022,2007 | 10.1088/0954-3899/34/8/S147 | null | hep-ph | null | We discuss the emission of high momentum lepton pairs (p_T>4 GeV) with low
invariant masses (M << p_T) in central Au+Au collisions at RHIC
(\sqrt{s_{NN}}=200 GeV). The spectra of dileptons produced through interactions
of quark and antiquark jets with the quark-gluon plasma (QGP) have been
calculated. Annihilation and Compton scattering processes, as well as processes
benefitting from collinear enhancement, including Landau-Pomeranchuk-Migdal
(LPM) effects, are calculated and convolved with a one dimensional hydrodynamic
expansion. The jet-induced contributions are compared to thermal dilepton
emission and Drell-Yan processes, and are found to dominate around p_T=4 GeV.
| [
{
"created": "Mon, 29 Jan 2007 20:20:30 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Turbide",
"Simon",
""
],
[
"Gale",
"Charles",
""
]
] | We discuss the emission of high momentum lepton pairs (p_T>4 GeV) with low invariant masses (M << p_T) in central Au+Au collisions at RHIC (\sqrt{s_{NN}}=200 GeV). The spectra of dileptons produced through interactions of quark and antiquark jets with the quark-gluon plasma (QGP) have been calculated. Annihilation and Compton scattering processes, as well as processes benefitting from collinear enhancement, including Landau-Pomeranchuk-Migdal (LPM) effects, are calculated and convolved with a one dimensional hydrodynamic expansion. The jet-induced contributions are compared to thermal dilepton emission and Drell-Yan processes, and are found to dominate around p_T=4 GeV. |
1904.09494 | Priyotosh Bandyopadhyay | Priyotosh Bandyopadhyay, Eung Jin Chun, Rusa Mandal | Phenomenology of Higgs bosons in inverse seesaw model with Type-X two
Higgs doublet at the LHC | 20 pages, 8 figures and 9 tables, reference added | JHEP08(2019)169 | 10.1007/JHEP08(2019)169 | IITH-PH-0001/19 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Type-X two Higgs doublet model is known to explain the muon $g-2$ anomaly
with a relatively light charged Higgs boson at large $\tan\beta$. The light
charged Higgs boson has been searched in the main $\tau \nu$ mode at the
colliders. Invoking a scenario of inverse seesaw as the origin of neutrino
masses and mixing, the charged Higgs boson can decay additionally to
right-handed neutrinos which leads to interesting phenomenology. Considering
generic lepton flavour violating signatures at the final states, a $5\sigma$
discovery can be achieved with the early data of LHC, at 14 TeV, for relatively
large inverse seesaw Yukawa coupling $Y_N$. The very light pseudoscalar and
charged Higgs boson mass reconstruction are performed using the new modes and
the results look promising. The inverse seesaw Yukawa coupling is shown to be
probed down to $Y_N \sim 0.2$ at HL LHC with 3000 fb$^{-1}$.
| [
{
"created": "Sat, 20 Apr 2019 20:14:26 GMT",
"version": "v1"
},
{
"created": "Mon, 2 Sep 2019 07:53:44 GMT",
"version": "v2"
}
] | 2019-09-04 | [
[
"Bandyopadhyay",
"Priyotosh",
""
],
[
"Chun",
"Eung Jin",
""
],
[
"Mandal",
"Rusa",
""
]
] | Type-X two Higgs doublet model is known to explain the muon $g-2$ anomaly with a relatively light charged Higgs boson at large $\tan\beta$. The light charged Higgs boson has been searched in the main $\tau \nu$ mode at the colliders. Invoking a scenario of inverse seesaw as the origin of neutrino masses and mixing, the charged Higgs boson can decay additionally to right-handed neutrinos which leads to interesting phenomenology. Considering generic lepton flavour violating signatures at the final states, a $5\sigma$ discovery can be achieved with the early data of LHC, at 14 TeV, for relatively large inverse seesaw Yukawa coupling $Y_N$. The very light pseudoscalar and charged Higgs boson mass reconstruction are performed using the new modes and the results look promising. The inverse seesaw Yukawa coupling is shown to be probed down to $Y_N \sim 0.2$ at HL LHC with 3000 fb$^{-1}$. |
0710.1492 | Wei Liao | Wei Liao | Precise Formulation of Neutrino Oscillation in the Earth | References added, 21 pages, 10 figures, version to appear in PRD | Phys.Rev.D77:053002,2008 | 10.1103/PhysRevD.77.053002 | null | hep-ph hep-ex | null | We give a perturbation theory of neutrino oscillation in the Earth. The
perturbation theory is valid for neutrinos with energy $E \gsim 0.5$ GeV. It is
formulated using trajectory dependent average potential. Non-adiabatic
contributions are included as the first order effects in the perturbation
theory. We analyze neutrino oscillation with standard matter effect and with
non-standard matter effect. In a three flavor analysis we show that the
perturbation theory gives a precise description of neutrino conversion in the
Earth. Effect of the Earth matter is substantially simplified in this
formulation.
| [
{
"created": "Mon, 8 Oct 2007 09:21:56 GMT",
"version": "v1"
},
{
"created": "Sun, 17 Feb 2008 06:28:42 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Liao",
"Wei",
""
]
] | We give a perturbation theory of neutrino oscillation in the Earth. The perturbation theory is valid for neutrinos with energy $E \gsim 0.5$ GeV. It is formulated using trajectory dependent average potential. Non-adiabatic contributions are included as the first order effects in the perturbation theory. We analyze neutrino oscillation with standard matter effect and with non-standard matter effect. In a three flavor analysis we show that the perturbation theory gives a precise description of neutrino conversion in the Earth. Effect of the Earth matter is substantially simplified in this formulation. |
hep-ph/9302263 | null | M. A. Doncheski, M. B. Gay Ducati and F. Halzen | $J/\psi$ at small-$x$ | 16 pages (6 figures not included - available from the authors),
MAD/PH/742 | null | null | null | hep-ph | null | It has been suggested that the suppression of $J/\psi$ production in heavy
nuclei is a signature of the formation of quark-gluon plasma. We here show that
this phenomenon can be understood in terms of conventional physics, {\it i.e.}
{\it i)} perturbative QCD, {\it ii)} the parton recombination implementation of
shadowing in the initial state, and {\it iii)} final state interactions with
the hadronic debris of the nuclear target. Unlike previous calculations we
include both the direct $J/\psi$ production and its production via radiative
$\chi$ decays ($\chi_J \to J/\psi + \gamma$). We are able to reproduce the
experimental data including their small-$x$ behavior. We emphasize the
importance of studying the $x_2$-dependence of the ratio $\sigma(b A)/\sigma(b
N)$, where $b$ designates the beam and $x_2$ is the momentum fraction of the
parton from the nuclear target.
| [
{
"created": "Tue, 16 Feb 1993 16:51:32 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Doncheski",
"M. A.",
""
],
[
"Ducati",
"M. B. Gay",
""
],
[
"Halzen",
"F.",
""
]
] | It has been suggested that the suppression of $J/\psi$ production in heavy nuclei is a signature of the formation of quark-gluon plasma. We here show that this phenomenon can be understood in terms of conventional physics, {\it i.e.} {\it i)} perturbative QCD, {\it ii)} the parton recombination implementation of shadowing in the initial state, and {\it iii)} final state interactions with the hadronic debris of the nuclear target. Unlike previous calculations we include both the direct $J/\psi$ production and its production via radiative $\chi$ decays ($\chi_J \to J/\psi + \gamma$). We are able to reproduce the experimental data including their small-$x$ behavior. We emphasize the importance of studying the $x_2$-dependence of the ratio $\sigma(b A)/\sigma(b N)$, where $b$ designates the beam and $x_2$ is the momentum fraction of the parton from the nuclear target. |
hep-ph/0612199 | Samina S. Masood | Mahnaz Haseeb and Samina S. Masood | Higher Order Thermal Corrections to Photon Self Energy | A talk presented at 12th Regional conference on Mathematical Physics,
NCP at Quaid-I-Azam University, Islamabad, Pakistan (to appear in the
Proceedings) | null | null | null | hep-ph | null | We investigate temperature behavior up to two loop level in QED in the
background heat bath using real time formalism. The thermal correction to the
coupling constant in QED at low temperature are presented up to the two loop
level. It is observed that the removal of singularities at the two loop level
is only possible if the integrations of loop momenta are done in a specific
order. Some of the possible applications of the results are also indicated.
| [
{
"created": "Fri, 15 Dec 2006 17:23:58 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Haseeb",
"Mahnaz",
""
],
[
"Masood",
"Samina S.",
""
]
] | We investigate temperature behavior up to two loop level in QED in the background heat bath using real time formalism. The thermal correction to the coupling constant in QED at low temperature are presented up to the two loop level. It is observed that the removal of singularities at the two loop level is only possible if the integrations of loop momenta are done in a specific order. Some of the possible applications of the results are also indicated. |
hep-ph/0504013 | Erhan Iltan | E. O. Iltan | The radiative lepton flavor violating decays in the split fermion
scenario in the two Higgs doublet model | 19 pages, 7 Figures | Mod.Phys.Lett.A22:819-833,2007 | 10.1142/S0217732307021238 | null | hep-ph | null | We study the branching ratios of the lepton flavor violating processes \mu ->
e \gamma, \tau -> e \gamma and \tau -> \mu\gamma in the split fermion scenario,
in the framework of the two Higgs doublet model. We observe that the branching
ratios are relatively more sensitive to the compactification scale and the
Gaussian widths of the leptons in the extra dimensions, for two extra
dimensions and especially for the \tau -> \mu \gamma decay.
| [
{
"created": "Sun, 3 Apr 2005 11:17:14 GMT",
"version": "v1"
},
{
"created": "Mon, 24 Jul 2006 10:44:36 GMT",
"version": "v2"
},
{
"created": "Wed, 24 Jan 2007 11:42:13 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Iltan",
"E. O.",
""
]
] | We study the branching ratios of the lepton flavor violating processes \mu -> e \gamma, \tau -> e \gamma and \tau -> \mu\gamma in the split fermion scenario, in the framework of the two Higgs doublet model. We observe that the branching ratios are relatively more sensitive to the compactification scale and the Gaussian widths of the leptons in the extra dimensions, for two extra dimensions and especially for the \tau -> \mu \gamma decay. |
hep-ph/0401172 | Jurgen Berges | J. Berges | n-Particle irreducible effective action techniques for gauge theories | 46 pages, PRD version, references added | Phys.Rev.D70:105010,2004 | 10.1103/PhysRevD.70.105010 | null | hep-ph hep-lat hep-th nucl-th | null | A loop or coupling expansion of a so-called n-particle irreducible (nPI)
generating functional provides a well-defined approximation scheme in terms of
self-consistently dressed propagators and n-point vertices. A self-consistently
complete description determines the functional for arbitrarily high n to a
given order in the expansion. We point out an equivalence hierarchy for nPI
effective actions, which allows one to obtain a self-consistently complete
result in practice. The method is applied to a SU(N) gauge theory with fermions
up to four-loop or O(g^6) corrections. For non-equilibrium we discuss the
connection to kinetic theory. The leading-order on-shell results in g can be
obtained from the three-loop effective action approximation, which already
includes in particular all diagrams enhanced by the Landau Pomeranchuk Migdal
effect. Furthermore, we compare the effective action approach with
Schwinger-Dyson (SD) equations. By construction, SD equations are expressed in
terms of loop diagrams including both classical and dressed vertices, which
leads to ambiguities of whether classical or dressed ones should be employed at
a given truncation order. We point out that these problems are absent using
effective action techniques. We show that a wide class of truncations of SD
equations cannot be obtained from the nPI effective action. In turn, our
results can be used to resolve SD ambiguities of whether classical or dressed
vertices should be employed at a given truncation order.
| [
{
"created": "Fri, 23 Jan 2004 09:05:14 GMT",
"version": "v1"
},
{
"created": "Tue, 18 May 2004 09:39:15 GMT",
"version": "v2"
},
{
"created": "Mon, 23 Aug 2004 10:52:28 GMT",
"version": "v3"
}
] | 2010-01-18 | [
[
"Berges",
"J.",
""
]
] | A loop or coupling expansion of a so-called n-particle irreducible (nPI) generating functional provides a well-defined approximation scheme in terms of self-consistently dressed propagators and n-point vertices. A self-consistently complete description determines the functional for arbitrarily high n to a given order in the expansion. We point out an equivalence hierarchy for nPI effective actions, which allows one to obtain a self-consistently complete result in practice. The method is applied to a SU(N) gauge theory with fermions up to four-loop or O(g^6) corrections. For non-equilibrium we discuss the connection to kinetic theory. The leading-order on-shell results in g can be obtained from the three-loop effective action approximation, which already includes in particular all diagrams enhanced by the Landau Pomeranchuk Migdal effect. Furthermore, we compare the effective action approach with Schwinger-Dyson (SD) equations. By construction, SD equations are expressed in terms of loop diagrams including both classical and dressed vertices, which leads to ambiguities of whether classical or dressed ones should be employed at a given truncation order. We point out that these problems are absent using effective action techniques. We show that a wide class of truncations of SD equations cannot be obtained from the nPI effective action. In turn, our results can be used to resolve SD ambiguities of whether classical or dressed vertices should be employed at a given truncation order. |
2007.12089 | Giovanni Pelliccioli | Ansgar Denner and Giovanni Pelliccioli | NLO QCD corrections to off-shell $\text{t}\bar{\text{t}}\text{W}^+$
production at the LHC | 30 pages, 16 figures, updated references, fixed typos, added results
for an additional central scale choice, extended comments on
double-pole-approximation, clarified treatment of top width, matches version
published by JHEP | null | 10.1007/JHEP11(2020)069 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present results of a computation of NLO QCD corrections to the production
of an off-shell top--antitop pair in association with an off-shell $\text{W}^+$
boson in proton--proton collisions. As the calculation is based on the full
matrix elements for the process $\text{p}\text{p}\to
{\text{e}}^+\nu_{\text{e}}\,\mu^-\bar{\nu}_\mu\,\tau^+\nu_\tau\,{\text{b}}\,\bar{\text{b}}$,
all off-shell, spin-correlation, and interference effects are included. The NLO
QCD corrections are about $20\%$ for the integrated cross-section. Using a
dynamical scale, the corrections to most distributions are at the same level,
while some distributions show much larger $K$-factors in suppressed regions of
phase space. We have performed a second calculation based on a double-pole
approximation. While the corresponding results agree with the full calculation
within few per cent for integrated cross-sections, the discrepancy can reach
$10\%$ and more in regions of phase space that are not dominated by
top--antitop production. As a consequence, on-shell calculations should only be
trusted to this level of accuracy.
| [
{
"created": "Thu, 23 Jul 2020 15:53:48 GMT",
"version": "v1"
},
{
"created": "Thu, 12 Nov 2020 12:06:29 GMT",
"version": "v2"
}
] | 2021-05-21 | [
[
"Denner",
"Ansgar",
""
],
[
"Pelliccioli",
"Giovanni",
""
]
] | We present results of a computation of NLO QCD corrections to the production of an off-shell top--antitop pair in association with an off-shell $\text{W}^+$ boson in proton--proton collisions. As the calculation is based on the full matrix elements for the process $\text{p}\text{p}\to {\text{e}}^+\nu_{\text{e}}\,\mu^-\bar{\nu}_\mu\,\tau^+\nu_\tau\,{\text{b}}\,\bar{\text{b}}$, all off-shell, spin-correlation, and interference effects are included. The NLO QCD corrections are about $20\%$ for the integrated cross-section. Using a dynamical scale, the corrections to most distributions are at the same level, while some distributions show much larger $K$-factors in suppressed regions of phase space. We have performed a second calculation based on a double-pole approximation. While the corresponding results agree with the full calculation within few per cent for integrated cross-sections, the discrepancy can reach $10\%$ and more in regions of phase space that are not dominated by top--antitop production. As a consequence, on-shell calculations should only be trusted to this level of accuracy. |
1608.06820 | Peter Vastag | Davide R. Campagnari, Ehsan Ebadati, Hugo Reinhardt and Peter Vastag | Revised variational approach to QCD in Coulomb gauge | null | Phys. Rev. D 94, 074027 (2016) | 10.1103/PhysRevD.94.074027 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The variational approach to QCD in Coulomb gauge is revisited. By assuming
the non-Abelian Coulomb potential to be given by the sum of its infrared and
ultraviolet parts, i.e.~by a linearly rising potential and an ordinary Coulomb
potential, and by using a Slater determinant ansatz for the quark wave
functional, which contains the coupling of the quarks and the gluons with two
different Dirac structures, we obtain variational equations for the kernels of
the fermionic vacuum wave functional, which are free of ultraviolet
divergences. Thereby, a Gaussian type wave functional is assumed for the
gluonic part of the vacuum. By using the results of the pure Yang--Mills sector
for the gluon propagator as input, we solve the equations for the fermionic
kernels numerically and calculate the quark condensate and the effective quark
mass in leading order. Assuming a value of $\sigma_{\mathrm{C}} = 2.5 \sigma$
for the Coulomb string tension (where $\sigma$ is the usual Wilsonian string
tension) the phenomenological value of the quark condensate $\langle \bar{\psi}
\psi \rangle \simeq (-235 \, \mathrm{MeV})^3$ is reproduced with a value of $g
\simeq 2.1$ for the strong coupling constant of the quark-gluon vertex.
| [
{
"created": "Wed, 24 Aug 2016 14:07:02 GMT",
"version": "v1"
}
] | 2016-10-26 | [
[
"Campagnari",
"Davide R.",
""
],
[
"Ebadati",
"Ehsan",
""
],
[
"Reinhardt",
"Hugo",
""
],
[
"Vastag",
"Peter",
""
]
] | The variational approach to QCD in Coulomb gauge is revisited. By assuming the non-Abelian Coulomb potential to be given by the sum of its infrared and ultraviolet parts, i.e.~by a linearly rising potential and an ordinary Coulomb potential, and by using a Slater determinant ansatz for the quark wave functional, which contains the coupling of the quarks and the gluons with two different Dirac structures, we obtain variational equations for the kernels of the fermionic vacuum wave functional, which are free of ultraviolet divergences. Thereby, a Gaussian type wave functional is assumed for the gluonic part of the vacuum. By using the results of the pure Yang--Mills sector for the gluon propagator as input, we solve the equations for the fermionic kernels numerically and calculate the quark condensate and the effective quark mass in leading order. Assuming a value of $\sigma_{\mathrm{C}} = 2.5 \sigma$ for the Coulomb string tension (where $\sigma$ is the usual Wilsonian string tension) the phenomenological value of the quark condensate $\langle \bar{\psi} \psi \rangle \simeq (-235 \, \mathrm{MeV})^3$ is reproduced with a value of $g \simeq 2.1$ for the strong coupling constant of the quark-gluon vertex. |
1007.2944 | Rumin Wang | Ru-Min Wang, Yuan-Guo Xu, Mo-Lin Liu, Bing-Zhong Li | Reevaluating R-parity Violating Supersymmetry Effects in
B_s^0-\bar{B}_s^0 Mixing | 18 pages, 4 figures. Three figures and some discussions improved,
matches published version | JHEP 1012:034,2010 | 10.1007/JHEP12(2010)034 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Recently, the CDF and D{\O} collaborations have claimed that the CP violating
phase in $B_s^0-\bar{B}_s^0$ mixing is large, which is contrary to the
expectations in the Standard Model. Such a large phase suggests New Physics
contributions to $B_s^0-\bar{B}_s^0$ mixing. Motivated by this, we reevaluate
the constraints on R-parity violating contributions, including baryon number
violating couplings not considered before, to the mixing mass matrix element
$M^s_{12}$ from the recent measurements of $B_s^0-\bar{B}_s^0$ mixing. We show
that present data allow us to put quite strong constraints on both the
magnitudes and the weak phases of the R-parity violating parameters. Some of
these bounds are better than the exciting ones, and some bounds are obtained
for the first time. Near future experiments at the Tevatron, the LHC and
B-factories can shrink or reveal the relevant parameter spaces of R-parity
violating couplings.
| [
{
"created": "Sat, 17 Jul 2010 17:38:49 GMT",
"version": "v1"
},
{
"created": "Thu, 22 Jul 2010 14:57:01 GMT",
"version": "v2"
},
{
"created": "Fri, 10 Dec 2010 10:21:03 GMT",
"version": "v3"
}
] | 2011-01-05 | [
[
"Wang",
"Ru-Min",
""
],
[
"Xu",
"Yuan-Guo",
""
],
[
"Liu",
"Mo-Lin",
""
],
[
"Li",
"Bing-Zhong",
""
]
] | Recently, the CDF and D{\O} collaborations have claimed that the CP violating phase in $B_s^0-\bar{B}_s^0$ mixing is large, which is contrary to the expectations in the Standard Model. Such a large phase suggests New Physics contributions to $B_s^0-\bar{B}_s^0$ mixing. Motivated by this, we reevaluate the constraints on R-parity violating contributions, including baryon number violating couplings not considered before, to the mixing mass matrix element $M^s_{12}$ from the recent measurements of $B_s^0-\bar{B}_s^0$ mixing. We show that present data allow us to put quite strong constraints on both the magnitudes and the weak phases of the R-parity violating parameters. Some of these bounds are better than the exciting ones, and some bounds are obtained for the first time. Near future experiments at the Tevatron, the LHC and B-factories can shrink or reveal the relevant parameter spaces of R-parity violating couplings. |
1212.4356 | Paolo Bolzoni | Paolo Bolzoni, Gustav Kramer | Inclusive lepton production from heavy-hadron decay in pp collisions at
the LHC | 15 pages, 15 figures, final published version, programming error in
the plots corrected | Nucl. Phys. B872 (2013) 253-264 (Erratum: Nucl. Phys. B876 (2013)
334-337) | 10.1016/j.nuclphysb.2013.04.002 | DESY-12-243 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present predictions for the inclusive production of leptons
($e^{\pm},\mu^{\pm}$) originating from charm and bottom-hadrons at the CERN LHC
in the general-mass variable-flavor-number scheme at next-to-leading order.
Detailed numerical results are compared to data of the CMS, ATLAS and ALICE
collaborations.
| [
{
"created": "Tue, 18 Dec 2012 14:19:14 GMT",
"version": "v1"
},
{
"created": "Tue, 9 Apr 2013 13:45:24 GMT",
"version": "v2"
},
{
"created": "Tue, 13 Aug 2013 07:07:58 GMT",
"version": "v3"
}
] | 2013-09-13 | [
[
"Bolzoni",
"Paolo",
""
],
[
"Kramer",
"Gustav",
""
]
] | We present predictions for the inclusive production of leptons ($e^{\pm},\mu^{\pm}$) originating from charm and bottom-hadrons at the CERN LHC in the general-mass variable-flavor-number scheme at next-to-leading order. Detailed numerical results are compared to data of the CMS, ATLAS and ALICE collaborations. |
1001.2452 | Thorsten Renk | Thorsten Renk | Theory of Heavy-Ion Collisions | Talk given at the XXIV International Symposium on Lepton Photon
Interactions at High Energies, Hamburg, Germany, 17-22 August 2009 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In high energy nucleus-nucleus collisions, a transient state of thermalized,
hot and dense matter governed by Quantum Chromodynamics is produced. Properties
of this state are reflected in the bulk low transverse momentum (P_T) hadron
production which represent the remnant of the collective medium as well as in
modifications of so-called probes which are not part of the thermalized medium,
i.e. jets generated in high P_T processes or leptons and photons which do not
participate in the strong interaction. Theory effords aim at deducing the
properties of QCD thermodynamics and collectivity from such observables.
| [
{
"created": "Thu, 14 Jan 2010 13:17:00 GMT",
"version": "v1"
}
] | 2010-01-15 | [
[
"Renk",
"Thorsten",
""
]
] | In high energy nucleus-nucleus collisions, a transient state of thermalized, hot and dense matter governed by Quantum Chromodynamics is produced. Properties of this state are reflected in the bulk low transverse momentum (P_T) hadron production which represent the remnant of the collective medium as well as in modifications of so-called probes which are not part of the thermalized medium, i.e. jets generated in high P_T processes or leptons and photons which do not participate in the strong interaction. Theory effords aim at deducing the properties of QCD thermodynamics and collectivity from such observables. |
1002.4655 | Annarita Margiotta | Giuseppe Battistoni, Annarita Margiotta, Silvia Muraro, Maximiliano
Sioli | FLUKA as a new high energy cosmic ray generator | Presented by A.Margiotta at the Very Large Volume neutrino Telescope
Workshop 2009 - VLVnT09, Athens, October 2009. 3 pages, 1 figure. To be
published in NIM A | Nucl.Instrum.Meth.A626-627:S191-S192,2011 | 10.1016/j.nima.2010.05.019 | null | hep-ph astro-ph.IM | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | FLUKA is a multipurpose Monte Carlo code, which can transport particles over
a wide range of energies in user-defined geometries. Here we present a new
FLUKA library, which allows the interaction and propagation of high energy
cosmic rays in the Earth atmosphere and the transport of high energy muons in
underground/underwater environments
| [
{
"created": "Wed, 24 Feb 2010 23:14:36 GMT",
"version": "v1"
}
] | 2011-02-03 | [
[
"Battistoni",
"Giuseppe",
""
],
[
"Margiotta",
"Annarita",
""
],
[
"Muraro",
"Silvia",
""
],
[
"Sioli",
"Maximiliano",
""
]
] | FLUKA is a multipurpose Monte Carlo code, which can transport particles over a wide range of energies in user-defined geometries. Here we present a new FLUKA library, which allows the interaction and propagation of high energy cosmic rays in the Earth atmosphere and the transport of high energy muons in underground/underwater environments |
hep-ph/0510331 | Thomas Schwetz | Thomas Schwetz | Neutrino oscillations: Current status and prospects | Talk given at the XXIX International Conference of Theoretical
Physics, ``Matter To The Deepest: Recent Developments In Physics of
Fundamental Interactions'', 8--14 September 2005, Ustron, Poland, 10 pages, 6
figures | Acta Phys.Polon. B36 (2005) 3203-3214 | null | SISSA 79/2005/EP | hep-ph | null | I summarize the status of neutrino oscillations from world neutrino
oscillation data with date of October 2005. The results of a global analysis
within the three-flavour framework are presented. Furthermore, a prospect on
where we could stand in neutrino oscillations in ten years from now is given,
based on a simulation of upcoming long-baseline accelerator and reactor
experiments.
| [
{
"created": "Tue, 25 Oct 2005 16:29:40 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Schwetz",
"Thomas",
""
]
] | I summarize the status of neutrino oscillations from world neutrino oscillation data with date of October 2005. The results of a global analysis within the three-flavour framework are presented. Furthermore, a prospect on where we could stand in neutrino oscillations in ten years from now is given, based on a simulation of upcoming long-baseline accelerator and reactor experiments. |
1611.08282 | Celso C. Nishi | C. C. Nishi, B. L. S\'anchez-Vega | Mu-tau reflection symmetry with a texture-zero | 8 pp., 1 figure. v2. updates references and few words. To appear in
JHEP | J. High Energ. Phys. (2017) 2017: 68 | 10.1007/JHEP01(2017)068 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The $\mu\tau$-reflection symmetry is a simple symmetry capable of predicting
all the unknown CP phases of the lepton sector and the atmospheric angle but
too simple to predict the absolute neutrino mass scale or the mass ordering. We
show that by combining it with a discrete abelian symmetry in a nontrivial way
we can additionally enforce a texture-zero and obtain a highly predictive
scenario where the lightest neutrino mass is fixed to be in the few meV range
for two normal ordering (NO) solutions or in the tens of meV in one inverted
ordering (IO) solution. The rate for neutrinoless double beta decay is
predicted to be negligible for NO or have effective mass $m_{\beta\beta}\approx
14\text{ -- }29\,{\rm meV}$ for IO, right in the region to be probed in future
experiments.
| [
{
"created": "Thu, 24 Nov 2016 18:30:08 GMT",
"version": "v1"
},
{
"created": "Mon, 16 Jan 2017 17:04:09 GMT",
"version": "v2"
}
] | 2017-01-23 | [
[
"Nishi",
"C. C.",
""
],
[
"Sánchez-Vega",
"B. L.",
""
]
] | The $\mu\tau$-reflection symmetry is a simple symmetry capable of predicting all the unknown CP phases of the lepton sector and the atmospheric angle but too simple to predict the absolute neutrino mass scale or the mass ordering. We show that by combining it with a discrete abelian symmetry in a nontrivial way we can additionally enforce a texture-zero and obtain a highly predictive scenario where the lightest neutrino mass is fixed to be in the few meV range for two normal ordering (NO) solutions or in the tens of meV in one inverted ordering (IO) solution. The rate for neutrinoless double beta decay is predicted to be negligible for NO or have effective mass $m_{\beta\beta}\approx 14\text{ -- }29\,{\rm meV}$ for IO, right in the region to be probed in future experiments. |
hep-ph/0304165 | Mikhail Voloshin | M.B.Voloshin | Remarks on the decays chi_{bJ}^\prime -> omega Upsilon | 4 pages | Mod.Phys.Lett.A18:1067,2003 | 10.1142/S021773230301082X | TPI-MINN-03/11-T, UMN-TH-2136-03 | hep-ph | null | The recently observed by CLEO cascade decays Upsilon(3S) -> gamma
chi_{bJ}^\prime -> gamma omega Upsilon are discussed. It is shown that within
the nonrelativistic description of bottomonium in the heavy b quark limit, the
ratio of the rates of the transitions chi_{bJ}^\prime -> omega Upsilon with J=1
and J=2 should be given by the ratio of the corresponding S wave phase space
factors. As a result, the rate of the observed cascade transitions through the
chi_{b2}^\prime resonance should be close to that through the chi_{b1}^\prime.
It is suggested that the ratio of the discussed cascade rates can also be
tested by measuring a simple angular correlation.
| [
{
"created": "Wed, 16 Apr 2003 18:08:33 GMT",
"version": "v1"
}
] | 2011-01-27 | [
[
"Voloshin",
"M. B.",
""
]
] | The recently observed by CLEO cascade decays Upsilon(3S) -> gamma chi_{bJ}^\prime -> gamma omega Upsilon are discussed. It is shown that within the nonrelativistic description of bottomonium in the heavy b quark limit, the ratio of the rates of the transitions chi_{bJ}^\prime -> omega Upsilon with J=1 and J=2 should be given by the ratio of the corresponding S wave phase space factors. As a result, the rate of the observed cascade transitions through the chi_{b2}^\prime resonance should be close to that through the chi_{b1}^\prime. It is suggested that the ratio of the discussed cascade rates can also be tested by measuring a simple angular correlation. |
1206.4202 | Philipp Leser | Gautam Bhattacharyya, Philipp Leser, Heinrich P\"as | Novel signatures of the Higgs sector from S3 flavor symmetry | 6 pages, 3 figures | Phys.Rev.D86:036009,2012 | 10.1103/PhysRevD.86.036009 | SINP/TNP/2012/07; DO-TH 12/20 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In an earlier work we analyzed the CP-even scalar sector of an S3 flavor
model, where we identified some novel decay signatures of an exotic scalar. In
this work we extend our analysis by including the complete set of
scalars/pseudoscalars, revisiting the potential minimization conditions in a
more general setup, setting the spectrum in conformity with the current LHC
limits on the scalar mass, and identifying yet another spectacularly novel
decay channel which might be revealed from an intense study of rare top decays
at the LHC into modes containing multileptons of different flavors.
| [
{
"created": "Tue, 19 Jun 2012 13:26:08 GMT",
"version": "v1"
},
{
"created": "Mon, 27 Aug 2012 12:49:17 GMT",
"version": "v2"
}
] | 2012-08-28 | [
[
"Bhattacharyya",
"Gautam",
""
],
[
"Leser",
"Philipp",
""
],
[
"Päs",
"Heinrich",
""
]
] | In an earlier work we analyzed the CP-even scalar sector of an S3 flavor model, where we identified some novel decay signatures of an exotic scalar. In this work we extend our analysis by including the complete set of scalars/pseudoscalars, revisiting the potential minimization conditions in a more general setup, setting the spectrum in conformity with the current LHC limits on the scalar mass, and identifying yet another spectacularly novel decay channel which might be revealed from an intense study of rare top decays at the LHC into modes containing multileptons of different flavors. |
2310.18671 | Peter Zeiler Skands | Peter Skands and Christian T. Preuss | NNLO Matrix-Element Corrections in VINCIA | Contribution to RADCOR 2023; 9 pages | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We report on a new formalism for parton showers whose fixed-order expansion
can be corrected through next-to-next-to-leading order (NNLO) in QCD. It is the
first such formalism we are aware of that has no dependence on any auxiliary
scales or external resummations and which is fully differential in all of the
relevant phase spaces. Since the shower acts as the phase-space generator, the
dominant singularity structures are encoded by construction and the method can
generate unweighted events with very high efficiency without any significant
initialisation time. We argue that the the method should be capable of
achieving (at least) NNLO+NNDL accuracy for the shower evolution variable and
use hadronic Z decays as a specific example.
| [
{
"created": "Sat, 28 Oct 2023 10:53:23 GMT",
"version": "v1"
}
] | 2023-10-31 | [
[
"Skands",
"Peter",
""
],
[
"Preuss",
"Christian T.",
""
]
] | We report on a new formalism for parton showers whose fixed-order expansion can be corrected through next-to-next-to-leading order (NNLO) in QCD. It is the first such formalism we are aware of that has no dependence on any auxiliary scales or external resummations and which is fully differential in all of the relevant phase spaces. Since the shower acts as the phase-space generator, the dominant singularity structures are encoded by construction and the method can generate unweighted events with very high efficiency without any significant initialisation time. We argue that the the method should be capable of achieving (at least) NNLO+NNDL accuracy for the shower evolution variable and use hadronic Z decays as a specific example. |
hep-ph/9608353 | Nishida Kozo | Kouzou Nishida, Ikuo S. Sogami | A Phenomenological Formula for KM Matrix | 9 pages, LaTeX, no figures | Prog.Theor.Phys.96:857-862,1996 | 10.1143/PTP.96.857 | null | hep-ph | null | We propose a phenomenological formula relating the Kobayashi-Maskawa matrix
$V_{KM}$ and quark masses in a form $(m_d,\ m_s,\ m_b)\propto (m_u,\ m_c,\
m_t)V_{KM}$. The formula agrees with experimental data well and has an
interesting geometric picture. The origin of such a formula is discussed in the
standard model.
| [
{
"created": "Sat, 17 Aug 1996 09:31:20 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"Nishida",
"Kouzou",
""
],
[
"Sogami",
"Ikuo S.",
""
]
] | We propose a phenomenological formula relating the Kobayashi-Maskawa matrix $V_{KM}$ and quark masses in a form $(m_d,\ m_s,\ m_b)\propto (m_u,\ m_c,\ m_t)V_{KM}$. The formula agrees with experimental data well and has an interesting geometric picture. The origin of such a formula is discussed in the standard model. |
hep-ph/0010156 | Deog Ki Hong | D. K. Hong (Pusan U., KIAS), H. K. Lee (Hanyang U.), M. A. Nowak
(Jagellonian U, KIAS) and Mannque Rho (Saclay, KIAS) | Neutrino Interactions In Color-Flavor-Locked Dense Matter | 13 pages. LaTeX. Talk given at the First KIAS Workshop on
Astrophysics, Seoul, May 2000; V2. references added. comments on cooling
changed | null | 10.1063/1.1368276 | KIAS-P00068 | hep-ph astro-ph nucl-th | null | At high density, diquarks could condense in the vacuum with the QCD color
spontaneously broken. Based on the observation that the symmetry breaking
pattern involved in this phenomenon is essentially the same as that of the
Pati-Salam model with broken electroweak--color SU(3) group, we determine the
relevant electroweak interactions in the color-flavor locked (CFL) phase in
high density QCD. We briefly comment on the possible implications on the
cooling of neutron stars.
| [
{
"created": "Mon, 16 Oct 2000 06:00:05 GMT",
"version": "v1"
},
{
"created": "Tue, 24 Oct 2000 12:29:18 GMT",
"version": "v2"
}
] | 2009-10-31 | [
[
"Hong",
"D. K.",
"",
"Pusan U., KIAS"
],
[
"Lee",
"H. K.",
"",
"Hanyang U."
],
[
"Nowak",
"M. A.",
"",
"Jagellonian U, KIAS"
],
[
"Rho",
"Mannque",
"",
"Saclay, KIAS"
]
] | At high density, diquarks could condense in the vacuum with the QCD color spontaneously broken. Based on the observation that the symmetry breaking pattern involved in this phenomenon is essentially the same as that of the Pati-Salam model with broken electroweak--color SU(3) group, we determine the relevant electroweak interactions in the color-flavor locked (CFL) phase in high density QCD. We briefly comment on the possible implications on the cooling of neutron stars. |
hep-ph/9608475 | Milo Svec | M.Svec (McGill University) | Amplitude analysis of reactions pi(-)p->etapi(-)p and pi(-)p->etapi(0)n
on polarized target and the exotic 1-+ meson | 23 pages | Phys.Rev.D56:4355-4364,1997 | 10.1103/PhysRevD.56.4355 | null | hep-ph | null | Recently several experimental groups analysed data on $\pi^- p \to \eta \pi^-
p$ and $\pi^- p \to \eta \pi^0 n$ reactions with exotic $1^{-+}$ $P$-wave and
found a conflicting evidence for an exotic meson $I=1 1^{-+} (1405)$. High
statistics data on these reactions are presently analysed by BNL E852
Collaboration. All these analyses are based on the crucial assumption that the
production amplitudes do not depend on nucleon spin. This assumption is in
sharp conflict with the results of measurements of $\pi^- p \to \pi^- \pi^+ n$,
$\pi^+ n \to \pi^+ \pi^- p$ and $K^+ n \to K^+ \pi^- p$ on polarized targets at
CERN which find a strong dependence of production amplitudes on nucleon spin.
To ascertain the existence of exotic meson $1^{-+} (1405)$, it is necessary to
perform a model-independent amplitude analysis of reactions $\pi^- p \to \eta
\pi^- p$ and $\pi^- p \to \eta\pi^0 n$. We demonstrate that measurements of
these reactions on transversely polarized targets enable the required model
independent amplitude analysis without the assumption that production
amplitudes are independent on nucleon spin. We suggest that high statistics
measurements of reactions $\pi^- p \to \eta\pi^- p$ and $\pi^- p \to\eta\pi^0
n$ be made on polarized targets at BNL and at Protvino IHEP, and that
model-independent amplitude analyses of this polarized data be performed to
advance hadron spectroscopy on the level of spin dependent production
amplitudes.
| [
{
"created": "Wed, 28 Aug 1996 21:51:00 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Svec",
"M.",
"",
"McGill University"
]
] | Recently several experimental groups analysed data on $\pi^- p \to \eta \pi^- p$ and $\pi^- p \to \eta \pi^0 n$ reactions with exotic $1^{-+}$ $P$-wave and found a conflicting evidence for an exotic meson $I=1 1^{-+} (1405)$. High statistics data on these reactions are presently analysed by BNL E852 Collaboration. All these analyses are based on the crucial assumption that the production amplitudes do not depend on nucleon spin. This assumption is in sharp conflict with the results of measurements of $\pi^- p \to \pi^- \pi^+ n$, $\pi^+ n \to \pi^+ \pi^- p$ and $K^+ n \to K^+ \pi^- p$ on polarized targets at CERN which find a strong dependence of production amplitudes on nucleon spin. To ascertain the existence of exotic meson $1^{-+} (1405)$, it is necessary to perform a model-independent amplitude analysis of reactions $\pi^- p \to \eta \pi^- p$ and $\pi^- p \to \eta\pi^0 n$. We demonstrate that measurements of these reactions on transversely polarized targets enable the required model independent amplitude analysis without the assumption that production amplitudes are independent on nucleon spin. We suggest that high statistics measurements of reactions $\pi^- p \to \eta\pi^- p$ and $\pi^- p \to\eta\pi^0 n$ be made on polarized targets at BNL and at Protvino IHEP, and that model-independent amplitude analyses of this polarized data be performed to advance hadron spectroscopy on the level of spin dependent production amplitudes. |
hep-ph/0507114 | Mohammad R. Ahmady | Mohammad R. Ahmady and Farrukh Chishtie | Nonspectator effects in B-> K^*+photon within the vector quark model | 7 pages, 1 figure, revised analysis | null | null | MTA-PHYS-0503 | hep-ph | null | The tree level FCNC due to the presence of an additional generation of vector
quarks result in the leading order nonspectator contributions to rare B->
K^*+photon decay mode. These tree level contributions are sensitive only to b->
s nonunitary parameter U^{sb} and therefore, provide a direct constraint on
this model parameter. We obtain the isospin asymmetry between \bar B^0->\bar
K^{*0}+photon and B^--> K^{*-}+photon to be \Delta_{0-}=-0.03*Re
(U^{sb}/(a^c_7V_{tb}V^*_{ts})) and the direct CP asymmetry between
B^+->K^{*+}+photon and B^--> K^{*-}+photon to be
A_{CP}^{VQM}=0.27|U^{sb}/(V_{tb}V_{ts}^*)|*sin{\theta}*sin{\phi_s}, where
\theta is the weak phase of U^{sb} and \phi_s is the strong phase of decay
amplitude. We predict a direct CP asymmetry of around a few percent if the
current experimental difference between \Delta_{0-} and \Delta_{0+} is to be
explained by the presence of the additional vector quarks.
| [
{
"created": "Sat, 9 Jul 2005 19:05:36 GMT",
"version": "v1"
},
{
"created": "Fri, 19 Aug 2005 13:47:45 GMT",
"version": "v2"
},
{
"created": "Mon, 27 Nov 2006 20:27:39 GMT",
"version": "v3"
}
] | 2007-05-23 | [
[
"Ahmady",
"Mohammad R.",
""
],
[
"Chishtie",
"Farrukh",
""
]
] | The tree level FCNC due to the presence of an additional generation of vector quarks result in the leading order nonspectator contributions to rare B-> K^*+photon decay mode. These tree level contributions are sensitive only to b-> s nonunitary parameter U^{sb} and therefore, provide a direct constraint on this model parameter. We obtain the isospin asymmetry between \bar B^0->\bar K^{*0}+photon and B^--> K^{*-}+photon to be \Delta_{0-}=-0.03*Re (U^{sb}/(a^c_7V_{tb}V^*_{ts})) and the direct CP asymmetry between B^+->K^{*+}+photon and B^--> K^{*-}+photon to be A_{CP}^{VQM}=0.27|U^{sb}/(V_{tb}V_{ts}^*)|*sin{\theta}*sin{\phi_s}, where \theta is the weak phase of U^{sb} and \phi_s is the strong phase of decay amplitude. We predict a direct CP asymmetry of around a few percent if the current experimental difference between \Delta_{0-} and \Delta_{0+} is to be explained by the presence of the additional vector quarks. |
2305.04974 | Xabier Marcano | Fabiola Fortuna, Xabier Marcano, Marcela Mar\'in and Pablo Roig | Lepton Flavor Violation from diphoton effective interactions | 11+6 pages, 4 figures. Extended discussion. Matches published version | Phys. Rev. D 108, 2023, 015008 | 10.1103/PhysRevD.108.015008 | IFT-UAM/CSIC-23-49 | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | We consider charged lepton flavor violating transitions mediated by the
diphoton effective interactions $\ell_i\ell_j\gamma\gamma$ and explore which
processes can probe them better. Our analysis includes single and double
radiative decays, $\ell_i\to\ell_j\gamma(\gamma)$, as well as $\ell_i\to\ell_j$
conversions in nuclei for all possible flavor combinations, which we compute
for the first time for $\ell\to\tau$ conversions in this framework. We find
that currently the best limits are provided by the loop-induced
$\ell_i\to\ell_j\gamma$ processes, while the best future sensitivities come
from $\mu\to e$ conversion in aluminum and from potential $\tau\to
\ell\gamma\gamma$ searches at Belle II or at the Super Tau Charm Facility. We
also motivate the search for $\mu\to e\gamma\gamma$ at the Mu3e experiment as a
complementary probe of these operators.
| [
{
"created": "Mon, 8 May 2023 18:07:15 GMT",
"version": "v1"
},
{
"created": "Wed, 12 Jul 2023 11:18:20 GMT",
"version": "v2"
}
] | 2023-07-13 | [
[
"Fortuna",
"Fabiola",
""
],
[
"Marcano",
"Xabier",
""
],
[
"Marín",
"Marcela",
""
],
[
"Roig",
"Pablo",
""
]
] | We consider charged lepton flavor violating transitions mediated by the diphoton effective interactions $\ell_i\ell_j\gamma\gamma$ and explore which processes can probe them better. Our analysis includes single and double radiative decays, $\ell_i\to\ell_j\gamma(\gamma)$, as well as $\ell_i\to\ell_j$ conversions in nuclei for all possible flavor combinations, which we compute for the first time for $\ell\to\tau$ conversions in this framework. We find that currently the best limits are provided by the loop-induced $\ell_i\to\ell_j\gamma$ processes, while the best future sensitivities come from $\mu\to e$ conversion in aluminum and from potential $\tau\to \ell\gamma\gamma$ searches at Belle II or at the Super Tau Charm Facility. We also motivate the search for $\mu\to e\gamma\gamma$ at the Mu3e experiment as a complementary probe of these operators. |
hep-ph/0401012 | Tomer Volansky | Micha Berkooz, Yosef Nir and Tomer Volansky (Weizmann Inst.) | Baryogenesis from the Kobayashi-Maskawa Phase | 4 pages | Phys.Rev.Lett. 93 (2004) 051301 | 10.1103/PhysRevLett.93.051301 | WIS/36/03-Dec-DPP | hep-ph astro-ph hep-th | null | The Standard Model fulfills the three Sakharov conditions for baryogenesis.
The smallness of quark masses suppresses, however, the CP violation from the
Kobayashi-Maskawa phase to a level that is many orders of magnitude below what
is required to explain the observed baryon asymmetry. We point out that if, as
a result of time variation in the Yukawa couplings, quark masses were large at
the time of the electroweak phase transition, then the Kobayashi-Maskawa
mechanism could be the source of the asymmetry. The Froggatt-Nielsen mechanism
provides a plausible framework where the Yukawa couplings could all be of order
one at that time, and settle to their present values before nucleosynthesis.
The problems related to a strong first order electroweak phase transition may
also be alleviated in this framework. Our scenario reveals a loophole in the
commonly held view that the Kobayashi-Maskawa mechanism cannot be the dominant
source of CP violation to play a role in baryogenesis.
| [
{
"created": "Sun, 4 Jan 2004 11:49:27 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Berkooz",
"Micha",
"",
"Weizmann Inst."
],
[
"Nir",
"Yosef",
"",
"Weizmann Inst."
],
[
"Volansky",
"Tomer",
"",
"Weizmann Inst."
]
] | The Standard Model fulfills the three Sakharov conditions for baryogenesis. The smallness of quark masses suppresses, however, the CP violation from the Kobayashi-Maskawa phase to a level that is many orders of magnitude below what is required to explain the observed baryon asymmetry. We point out that if, as a result of time variation in the Yukawa couplings, quark masses were large at the time of the electroweak phase transition, then the Kobayashi-Maskawa mechanism could be the source of the asymmetry. The Froggatt-Nielsen mechanism provides a plausible framework where the Yukawa couplings could all be of order one at that time, and settle to their present values before nucleosynthesis. The problems related to a strong first order electroweak phase transition may also be alleviated in this framework. Our scenario reveals a loophole in the commonly held view that the Kobayashi-Maskawa mechanism cannot be the dominant source of CP violation to play a role in baryogenesis. |
1810.04492 | Fulvia De Fazio | S. Campanella, P. Colangelo and F. De Fazio | Excited heavy meson decays to light vector mesons: implications for
spectroscopy | RevTex, 26 pages, 18 figures. Matches published version | Phys. Rev. D 98, 114028 (2018) | 10.1103/PhysRevD.98.114028 | BARI-TH/718-2018 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We analyze strong decays of excited charmed and beauty mesons into a light
vector meson, exploiting the effective field theory based on heavy quark (HQ)
symmetries for heavy mesons, and on the hidden gauge symmetry to incorporate
light vector mesons. HQ symmetries allow to classify the heavy mesons in spin
doublets, and to relate decays of excited states. We build effective Lagrangian
terms governing the ${\cal H}_i \to P^{(*)} V$ modes, with ${\cal H}_i$ an
excited $s$, $p$, $d$ and $f$-wave heavy-light quark meson, $P,\,P^*$ the
lowest-lying $J^P=(0^-,\,1^-)$ heavy-light mesons, and V a light vector meson.
Predictions are provided for ratios of decay widths that are independent of the
strong couplings in the effective Lagrangian terms. A classification of the
newly observed heavy-light mesons is proposed.
| [
{
"created": "Wed, 10 Oct 2018 12:58:40 GMT",
"version": "v1"
},
{
"created": "Wed, 9 Jan 2019 10:00:04 GMT",
"version": "v2"
}
] | 2019-01-10 | [
[
"Campanella",
"S.",
""
],
[
"Colangelo",
"P.",
""
],
[
"De Fazio",
"F.",
""
]
] | We analyze strong decays of excited charmed and beauty mesons into a light vector meson, exploiting the effective field theory based on heavy quark (HQ) symmetries for heavy mesons, and on the hidden gauge symmetry to incorporate light vector mesons. HQ symmetries allow to classify the heavy mesons in spin doublets, and to relate decays of excited states. We build effective Lagrangian terms governing the ${\cal H}_i \to P^{(*)} V$ modes, with ${\cal H}_i$ an excited $s$, $p$, $d$ and $f$-wave heavy-light quark meson, $P,\,P^*$ the lowest-lying $J^P=(0^-,\,1^-)$ heavy-light mesons, and V a light vector meson. Predictions are provided for ratios of decay widths that are independent of the strong couplings in the effective Lagrangian terms. A classification of the newly observed heavy-light mesons is proposed. |
2104.05770 | Roberto Franceschini | Roberto Franceschini, Mario Greco | Higgs and BSM Physics at the future Muon Collider | prepared for a Special Issue "Physics Potential of the Muon Collider"
of "Symmetry" | null | null | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | We describe recent work on the physics of the Higgs boson at future muon
colliders. Starting from the low energy muon collider at the Higgs boson pole
we extend our discussion to the multi-TeV muon collider and outline the physics
case for such machines about the properties of the Higgs boson and physics
beyond the Standard Model that can be possibly discovered.
| [
{
"created": "Mon, 12 Apr 2021 18:59:59 GMT",
"version": "v1"
}
] | 2021-04-14 | [
[
"Franceschini",
"Roberto",
""
],
[
"Greco",
"Mario",
""
]
] | We describe recent work on the physics of the Higgs boson at future muon colliders. Starting from the low energy muon collider at the Higgs boson pole we extend our discussion to the multi-TeV muon collider and outline the physics case for such machines about the properties of the Higgs boson and physics beyond the Standard Model that can be possibly discovered. |
1809.02369 | Hua-Sheng Shao | Hua-Sheng Shao | Boosting perturbative QCD stability in quarkonium production | 40 pages, 26 figures, 3 tables; v2: journal version, fix a few typos
fixed, add two figures, reorganize the figures | JHEP 01 (2019) 112 | 10.1007/JHEP01(2019)112 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The aim of this paper is to introduce a general way to stabilize the
perturbative QCD computations of heavy quarkonium production in the boosted or
high-momentum transferring region with tree-level generators only. Such an
approach is possible by properly taking into account the power-enhanced
perturbative contributions in a soft and collinear safe manner without
requiring any complete higher-order computations. The complicated NLO results
for inclusive quarkonium hadroproduction can be well reproduced within our
approach based on a tree-level generator {\sc\small HELAC-Onia}. We have
applied it to estimate the last missing leading-twist contribution from the
spin-triplet color-singlet S-wave production at $\mathcal{O}(\alpha_s^5)$,
which is a NNLO term in the $\alpha_s$ expansion for the quarkonium $P_T$
spectrum. We conclude that the missing NNLO contribution will not change the
order of the magnitude of the short-distance coefficient. Such an approach is
also quite appealing as it foresees broad applications in quarkonium-associated
production processes, which are mostly absent of complete higher-order
computations and fragmentation functions.
| [
{
"created": "Fri, 7 Sep 2018 09:27:57 GMT",
"version": "v1"
},
{
"created": "Wed, 16 Jan 2019 14:55:06 GMT",
"version": "v2"
}
] | 2019-01-17 | [
[
"Shao",
"Hua-Sheng",
""
]
] | The aim of this paper is to introduce a general way to stabilize the perturbative QCD computations of heavy quarkonium production in the boosted or high-momentum transferring region with tree-level generators only. Such an approach is possible by properly taking into account the power-enhanced perturbative contributions in a soft and collinear safe manner without requiring any complete higher-order computations. The complicated NLO results for inclusive quarkonium hadroproduction can be well reproduced within our approach based on a tree-level generator {\sc\small HELAC-Onia}. We have applied it to estimate the last missing leading-twist contribution from the spin-triplet color-singlet S-wave production at $\mathcal{O}(\alpha_s^5)$, which is a NNLO term in the $\alpha_s$ expansion for the quarkonium $P_T$ spectrum. We conclude that the missing NNLO contribution will not change the order of the magnitude of the short-distance coefficient. Such an approach is also quite appealing as it foresees broad applications in quarkonium-associated production processes, which are mostly absent of complete higher-order computations and fragmentation functions. |
hep-ph/9905312 | Gerhard Buchalla | M. Beneke, G. Buchalla, M. Neubert, and C.T. Sachrajda | QCD Factorization for $B\to\pi\pi$ Decays: Strong Phases and CP
Violation in the Heavy Quark Limit | 6 pages, 1 figure | Phys.Rev.Lett.83:1914-1917,1999 | 10.1103/PhysRevLett.83.1914 | CERN-TH/99-126, SLAC-PUB-8146, SHEP 99/04 | hep-ph | null | We show that, in the heavy quark limit, the hadronic matrix elements that
enter $B$ meson decays into two light mesons can be computed from first
principles, including `non-factorizable' strong interaction corrections, and
expressed in terms of form factors and meson light-cone distribution
amplitudes. The conventional factorization result follows in the limit when
both power corrections in $1/m_b$ and radiative corrections in $\alpha_s$ are
neglected. We compute the order-$\alpha_s$ corrections to the decays
$B_d\to\pi^+\pi^-$, $B_d\to\pi^0\pi^0$ and $B^+\to\pi^+\pi^0$ in the heavy
quark limit and briefly discuss the phenomenological implications for the
branching ratios, strong phases and CP violation.
| [
{
"created": "Tue, 11 May 1999 23:16:38 GMT",
"version": "v1"
}
] | 2009-10-09 | [
[
"Beneke",
"M.",
""
],
[
"Buchalla",
"G.",
""
],
[
"Neubert",
"M.",
""
],
[
"Sachrajda",
"C. T.",
""
]
] | We show that, in the heavy quark limit, the hadronic matrix elements that enter $B$ meson decays into two light mesons can be computed from first principles, including `non-factorizable' strong interaction corrections, and expressed in terms of form factors and meson light-cone distribution amplitudes. The conventional factorization result follows in the limit when both power corrections in $1/m_b$ and radiative corrections in $\alpha_s$ are neglected. We compute the order-$\alpha_s$ corrections to the decays $B_d\to\pi^+\pi^-$, $B_d\to\pi^0\pi^0$ and $B^+\to\pi^+\pi^0$ in the heavy quark limit and briefly discuss the phenomenological implications for the branching ratios, strong phases and CP violation. |
0911.0296 | Bernd-Jochen Schaefer | Jochen Wambach, Bernd-Jochen Schaefer, Mathias Wagner | QCD Thermodynamics: Confronting the Polyakov-Quark-Meson Model with
Lattice QCD | 10 pages, 4 figures, contributed to the proceedings of the EMMI
Workshop and XXVI Max Born Symposium at 09th-11th of July 2009 in Wroclaw,
Poland | Acta Phys.Polon.Supp.3:691-700,2010 | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | NJL-type effective models represent a low-energy realization of QCD and
incorporate pertinent aspects such as chiral symmetry and its spontaneous
breaking, the center symmetry in the heavy-quark limit as well as the axial
anomaly. One such model, the Polyakov-quark-meson model for three light quark
flavors, is introduced in order to study the phase structure of
strongly-interacting matter. With recent high-statistics lattice QCD
simulations of the finite-temperature equation of state, a detailed comparison
with model results becomes accessible. Such comparisons allow to estimate
volume and truncation effects of quantities, obtained on the lattice and
provide possible lattice extrapolation procedures to finite chemical potential
which are important to locate a critical endpoint in the QCD phase diagram.
| [
{
"created": "Mon, 2 Nov 2009 15:09:27 GMT",
"version": "v1"
}
] | 2010-11-01 | [
[
"Wambach",
"Jochen",
""
],
[
"Schaefer",
"Bernd-Jochen",
""
],
[
"Wagner",
"Mathias",
""
]
] | NJL-type effective models represent a low-energy realization of QCD and incorporate pertinent aspects such as chiral symmetry and its spontaneous breaking, the center symmetry in the heavy-quark limit as well as the axial anomaly. One such model, the Polyakov-quark-meson model for three light quark flavors, is introduced in order to study the phase structure of strongly-interacting matter. With recent high-statistics lattice QCD simulations of the finite-temperature equation of state, a detailed comparison with model results becomes accessible. Such comparisons allow to estimate volume and truncation effects of quantities, obtained on the lattice and provide possible lattice extrapolation procedures to finite chemical potential which are important to locate a critical endpoint in the QCD phase diagram. |
1405.0622 | Charlotte Strege | C. Strege, G. Bertone, G. J. Besjes, S. Caron, R. Ruiz de Austri, A.
Strubig and R. Trotta | Profile likelihood maps of a 15-dimensional MSSM | 52 pages, 21 figures, submitted to JHEP | null | 10.1007/JHEP09(2014)081 | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present statistically convergent profile likelihood maps obtained via
global fits of a phenomenological Minimal Supersymmetric Standard Model with 15
free parameters (the MSSM-15), based on over 250M points. We derive constraints
on the model parameters from direct detection limits on dark matter, the Planck
relic density measurement and data from accelerator searches. We provide a
detailed analysis of the rich phenomenology of this model, and determine the
SUSY mass spectrum and dark matter properties that are preferred by current
experimental constraints. We evaluate the impact of the measurement of the
anomalous magnetic moment of the muon ($g-2$) on our results, and provide an
analysis of scenarios in which the lightest neutralino is a subdominant
component of the dark matter. The MSSM-15 parameters are relatively weakly
constrained by current data sets, with the exception of the parameters related
to dark matter phenomenology ($M_1$, $M_2$, $\mu$), which are restricted to the
sub-TeV regime, mainly due to the relic density constraint. The mass of the
lightest neutralino is found to be < 1.5 TeV at 99% C.L., but can extend up to
3 TeV when excluding the $g - 2$ constraint from the analysis. Low-mass
bino-like neutralinos are strongly favoured, with spin-independent scattering
cross-sections extending to very small values, $\sim 10^{-20}$ pb. ATLAS SUSY
null searches strongly impact on this mass range, and thus rule out a region of
parameter space that is outside the reach of any current or future direct
detection experiment. The best-fit point obtained after inclusion of all data
corresponds to a squark mass of 2.3 TeV, a gluino mass of 2.1 TeV and a 130 GeV
neutralino with a spin-independent cross-section of $2.4 \times 10^{-10}$ pb,
which is within the reach of future multi-ton scale direct detection
experiments and of the upcoming LHC run at increased centre-of-mass energy.
| [
{
"created": "Sat, 3 May 2014 21:20:19 GMT",
"version": "v1"
}
] | 2015-06-19 | [
[
"Strege",
"C.",
""
],
[
"Bertone",
"G.",
""
],
[
"Besjes",
"G. J.",
""
],
[
"Caron",
"S.",
""
],
[
"de Austri",
"R. Ruiz",
""
],
[
"Strubig",
"A.",
""
],
[
"Trotta",
"R.",
""
]
] | We present statistically convergent profile likelihood maps obtained via global fits of a phenomenological Minimal Supersymmetric Standard Model with 15 free parameters (the MSSM-15), based on over 250M points. We derive constraints on the model parameters from direct detection limits on dark matter, the Planck relic density measurement and data from accelerator searches. We provide a detailed analysis of the rich phenomenology of this model, and determine the SUSY mass spectrum and dark matter properties that are preferred by current experimental constraints. We evaluate the impact of the measurement of the anomalous magnetic moment of the muon ($g-2$) on our results, and provide an analysis of scenarios in which the lightest neutralino is a subdominant component of the dark matter. The MSSM-15 parameters are relatively weakly constrained by current data sets, with the exception of the parameters related to dark matter phenomenology ($M_1$, $M_2$, $\mu$), which are restricted to the sub-TeV regime, mainly due to the relic density constraint. The mass of the lightest neutralino is found to be < 1.5 TeV at 99% C.L., but can extend up to 3 TeV when excluding the $g - 2$ constraint from the analysis. Low-mass bino-like neutralinos are strongly favoured, with spin-independent scattering cross-sections extending to very small values, $\sim 10^{-20}$ pb. ATLAS SUSY null searches strongly impact on this mass range, and thus rule out a region of parameter space that is outside the reach of any current or future direct detection experiment. The best-fit point obtained after inclusion of all data corresponds to a squark mass of 2.3 TeV, a gluino mass of 2.1 TeV and a 130 GeV neutralino with a spin-independent cross-section of $2.4 \times 10^{-10}$ pb, which is within the reach of future multi-ton scale direct detection experiments and of the upcoming LHC run at increased centre-of-mass energy. |
1906.10193 | Leonardo De Lima | Nayara Fonseca, Benedict von Harling, Leonardo de Lima and Camila S.
Machado | The Super-Planckian Axion Strikes Back | 5 pages + appendices, 1 figure | Phys. Rev. D 100, 105019 (2019) | 10.1103/PhysRevD.100.105019 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a novel framework for obtaining large hierarchies in axion decay
constants as well as trans-Planckian field excursions, with no need for tuning
or a large number of fields. We consider a model with two or more CFTs with a
common cutoff, that are linked by a gauged diagonal symmetry. This construction
is dual to the geometry of a warped space with two or more throats glued at a
common brane, allowing for calculability. Many applications of our setup are
possible,such as ultra-light axions, natural inflation, and relaxion models.
| [
{
"created": "Mon, 24 Jun 2019 19:36:15 GMT",
"version": "v1"
}
] | 2019-11-27 | [
[
"Fonseca",
"Nayara",
""
],
[
"von Harling",
"Benedict",
""
],
[
"de Lima",
"Leonardo",
""
],
[
"Machado",
"Camila S.",
""
]
] | We present a novel framework for obtaining large hierarchies in axion decay constants as well as trans-Planckian field excursions, with no need for tuning or a large number of fields. We consider a model with two or more CFTs with a common cutoff, that are linked by a gauged diagonal symmetry. This construction is dual to the geometry of a warped space with two or more throats glued at a common brane, allowing for calculability. Many applications of our setup are possible,such as ultra-light axions, natural inflation, and relaxion models. |
1012.4443 | Emerson Luna | E.G.S. Luna, A.A. Natale and A.L. dos Santos | QCD effective charge and the structure function $F_{2}$ at small-$x$ | 20 pages, 2 figures, references and remarks added, version to appear
in PLB | Phys.Lett.B698:52-58,2011 | 10.1016/j.physletb.2011.02.057 | null | hep-ph hep-ex hep-lat | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study infrared contributions to the QCD description of the HERA data on
the structure function $F_{2}$ within the \textit{generalized} DAS
approximation. We argue that this approximation is a natural one and consistent
with the phenomenon of dynamical mass generation in QCD. The investigation is
performed at next-to-leading order by using the leading-twist expansion of
$F_{2}(x,Q^{2})$ and by adopting an effective charge whose finite infrared
behavior is constrained by a dynamical gluon mass. We propose one ansatz for
the behavior of this effective coupling beyond leading order. The dependence of
the experimental data on the infrared value of the effective charge is used in
order to study the asymptotic behavior of the running gluon mass. The deep
inelastic structure function $F_{2}$ obtained in this approach shows very good
agreement with the experimental data.
| [
{
"created": "Mon, 20 Dec 2010 19:11:44 GMT",
"version": "v1"
},
{
"created": "Fri, 11 Mar 2011 17:34:56 GMT",
"version": "v2"
}
] | 2011-03-28 | [
[
"Luna",
"E. G. S.",
""
],
[
"Natale",
"A. A.",
""
],
[
"Santos",
"A. L. dos",
""
]
] | We study infrared contributions to the QCD description of the HERA data on the structure function $F_{2}$ within the \textit{generalized} DAS approximation. We argue that this approximation is a natural one and consistent with the phenomenon of dynamical mass generation in QCD. The investigation is performed at next-to-leading order by using the leading-twist expansion of $F_{2}(x,Q^{2})$ and by adopting an effective charge whose finite infrared behavior is constrained by a dynamical gluon mass. We propose one ansatz for the behavior of this effective coupling beyond leading order. The dependence of the experimental data on the infrared value of the effective charge is used in order to study the asymptotic behavior of the running gluon mass. The deep inelastic structure function $F_{2}$ obtained in this approach shows very good agreement with the experimental data. |
1610.08603 | Matthew Klimek | Matthew D. Klimek | Ordered Kinematic Endpoints for 5-body Cascade Decays | 26 pages, 3 figures, 4 tables | null | 10.1007/JHEP12(2016)132 | UTTG-17-16 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present expressions for the kinematic endpoints of 5-body cascade decay
chains proceeding through all possible combinations of 2-body and 3-body
decays, with one stable invisible particle in the final decay stage. When an
invariant mass can be formed in multiple ways by choosing different final state
particles from a common vertex, we introduce techniques for finding the
sub-leading endpoints for all indistinguishable versions of the invariant mass.
In contrast to short decay chains, where sub-leading endpoints are linearly
related to the leading endpoints, we find that in 5-body decays, they provide
additional independent constraints on the mass spectrum.
| [
{
"created": "Thu, 27 Oct 2016 03:51:24 GMT",
"version": "v1"
}
] | 2017-02-01 | [
[
"Klimek",
"Matthew D.",
""
]
] | We present expressions for the kinematic endpoints of 5-body cascade decay chains proceeding through all possible combinations of 2-body and 3-body decays, with one stable invisible particle in the final decay stage. When an invariant mass can be formed in multiple ways by choosing different final state particles from a common vertex, we introduce techniques for finding the sub-leading endpoints for all indistinguishable versions of the invariant mass. In contrast to short decay chains, where sub-leading endpoints are linearly related to the leading endpoints, we find that in 5-body decays, they provide additional independent constraints on the mass spectrum. |
hep-ph/0510314 | Zhi-Zhong Xing | Zhi-zhong Xing | Running CP-violating Phases of Majorana Neutrinos | PoS style 4 pages. Talk given at the International Europhysics
Conference on High Energy Physics, July 21st - 27th 2005, Lisboa, Portugal | null | null | null | hep-ph | null | Three CP-violating phases of the $3\times 3$ lepton flavor mixing matrix $V$,
denoted as $\delta$, $\rho$ and $\sigma$ in a useful phase convention, are
entangled with one another in the one-loop renormalization-group equations. We
show that $\delta =90^\circ$ at the electroweak scale ($\Lambda_{\rm EW} \sim
10^{2}$ GeV) can be radiatively generated from $\delta =0^\circ$ at the seesaw
scale ($\Lambda_{\rm SS} \sim 10^{14}$ GeV) in the minimal supersymmetric
standard model, provided three neutrino masses are nearly degenerate. As for
the Majorana phases $\rho$ and $\sigma$, it is also possible to radiatively
generate $\rho =90^\circ$ or $\sigma = 90^\circ$ at $\Lambda_{\rm EW}$ from
$\rho =0^\circ$ or $\sigma = 0^\circ$ at $\Lambda_{\rm SS}$. This observation
opens a new and interesting window for model building, in order to understand
possible connection between the phenomena of CP violation at low- and
high-energy scales.
| [
{
"created": "Mon, 24 Oct 2005 09:09:25 GMT",
"version": "v1"
}
] | 2009-04-25 | [
[
"Xing",
"Zhi-zhong",
""
]
] | Three CP-violating phases of the $3\times 3$ lepton flavor mixing matrix $V$, denoted as $\delta$, $\rho$ and $\sigma$ in a useful phase convention, are entangled with one another in the one-loop renormalization-group equations. We show that $\delta =90^\circ$ at the electroweak scale ($\Lambda_{\rm EW} \sim 10^{2}$ GeV) can be radiatively generated from $\delta =0^\circ$ at the seesaw scale ($\Lambda_{\rm SS} \sim 10^{14}$ GeV) in the minimal supersymmetric standard model, provided three neutrino masses are nearly degenerate. As for the Majorana phases $\rho$ and $\sigma$, it is also possible to radiatively generate $\rho =90^\circ$ or $\sigma = 90^\circ$ at $\Lambda_{\rm EW}$ from $\rho =0^\circ$ or $\sigma = 0^\circ$ at $\Lambda_{\rm SS}$. This observation opens a new and interesting window for model building, in order to understand possible connection between the phenomena of CP violation at low- and high-energy scales. |
2104.07050 | Oscar Garcia-Montero | Oscar Garcia-Montero | Anomalous dilepton production from the Dirac sea in p+p collisions | 5 pages, 1 figure | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In a recent work from the ALICE collaboration an excess of relatively soft
dilepton pairs was reported in p+p collisions at $13$ TeV. In the report no
satisfactory explanation was found via standard bremsstrahlung computations. In
this letter, \textit{anomalous} dilepton pairs are produced non-perturbatively
from the back-reaction of the vacuum to a $q\bar{q}$ pair, travelling
back-to-back. The dilepton spectrum is computed by folding this rate with the
cross-section for the process p+p$\rightarrow q\bar{q}$, which was computed
using the framework of the Color Glass Condensate Effective Field Theory (CGC
EFT) in the $k_\perp$-factorized limit. The resulting spectra is compatible
within uncertainties with the data, and moreover, provides exciting insight
into the non-perturbative phenomena that ultra-soft electromagnetic radiation
can probe.
| [
{
"created": "Wed, 14 Apr 2021 18:01:28 GMT",
"version": "v1"
},
{
"created": "Tue, 27 Apr 2021 18:04:48 GMT",
"version": "v2"
}
] | 2021-04-29 | [
[
"Garcia-Montero",
"Oscar",
""
]
] | In a recent work from the ALICE collaboration an excess of relatively soft dilepton pairs was reported in p+p collisions at $13$ TeV. In the report no satisfactory explanation was found via standard bremsstrahlung computations. In this letter, \textit{anomalous} dilepton pairs are produced non-perturbatively from the back-reaction of the vacuum to a $q\bar{q}$ pair, travelling back-to-back. The dilepton spectrum is computed by folding this rate with the cross-section for the process p+p$\rightarrow q\bar{q}$, which was computed using the framework of the Color Glass Condensate Effective Field Theory (CGC EFT) in the $k_\perp$-factorized limit. The resulting spectra is compatible within uncertainties with the data, and moreover, provides exciting insight into the non-perturbative phenomena that ultra-soft electromagnetic radiation can probe. |
1004.0296 | Tong Li | Tong Li, Wei Chao | Neutrino Masses, Dark Matter and B-L Symmetry at the LHC | 20 pages, 9 figures and 2 tables, revised version accepted for
publication in Nucl. Phys. B | Nucl.Phys.B843:396-412,2011 | 10.1016/j.nuclphysb.2010.10.004 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We establish a hybrid seesaw mechanism to explain small neutrino masses and
predict cold dark matter candidate in the context of the B-L gauge symmetry
extension of the Standard Model. In this model a new scalar doublet and two new
fermion singlets are introduced at loop-level beyond the minimal Type I seesaw.
The lightest particle inside the loop can be dark matter candidate. We study in
detail the constraints from neutrino oscillation data, lepton flavor violating
processes and cosmological observation. We also explore the predictions of the
decays of the new charged scalars in each spectrum of neutrino masses and show
the most optimistic scenarios to distinguish the spectra. We consider the pair
production of the stable fermion associated with two observable SM charged
leptons at the LHC, which occurs in a two-step cascade decay of the new gauge
boson Z' and the new charged scalars stand as intermediate particles. The
masses of missing dark matter and its parent particle can be well-determined in
such production topology.
| [
{
"created": "Fri, 2 Apr 2010 07:00:01 GMT",
"version": "v1"
},
{
"created": "Mon, 18 Oct 2010 14:53:14 GMT",
"version": "v2"
}
] | 2015-03-13 | [
[
"Li",
"Tong",
""
],
[
"Chao",
"Wei",
""
]
] | We establish a hybrid seesaw mechanism to explain small neutrino masses and predict cold dark matter candidate in the context of the B-L gauge symmetry extension of the Standard Model. In this model a new scalar doublet and two new fermion singlets are introduced at loop-level beyond the minimal Type I seesaw. The lightest particle inside the loop can be dark matter candidate. We study in detail the constraints from neutrino oscillation data, lepton flavor violating processes and cosmological observation. We also explore the predictions of the decays of the new charged scalars in each spectrum of neutrino masses and show the most optimistic scenarios to distinguish the spectra. We consider the pair production of the stable fermion associated with two observable SM charged leptons at the LHC, which occurs in a two-step cascade decay of the new gauge boson Z' and the new charged scalars stand as intermediate particles. The masses of missing dark matter and its parent particle can be well-determined in such production topology. |
1209.1097 | Matthew Reece | JiJi Fan and Matthew Reece | A Simple Recipe for the 111 and 128 GeV Lines | 5 pages, 3 figures; v2: slightly expanded discussion, to appear in
Phys Rev D | null | 10.1103/PhysRevD.88.035014 | null | hep-ph astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Recently evidence for gamma ray lines at energies of approximately 111 and
128 GeV has been found in Fermi-LAT data from the center of the galaxy and from
unassociated point sources. Many explanations in terms of dark matter particle
pairs annihilating to gamma gamma and gamma Z have been suggested, but these
typically require very large couplings or mysterious coincidences in the masses
of several new particles to fit the signal strength. We propose a simple novel
explanation in which dark matter is part of a multiplet of new states which all
have mass near 260 GeV as a result of symmetry. Two dark matter particles
annihilate to a pair of neutral particles in this multiplet which subsequently
decay to gamma gamma and gamma Z. For example, one may have a triplet of
pseudo-Nambu-Goldstone bosons, charged pions and a neutral pion, where the
charged pions are stabilized by their charge under a new U(1) symmetry and the
slightly lighter neutral pion state decays to gamma gamma and gamma Z. The
symmetry structure of such a model explains the near degeneracy in masses
needed for the resulting photons to have a line-like shape and the large
observed flux. The tunable lifetime of the neutral state allows such models to
go unseen at direct detection or collider experiments that can constrain most
other explanations. However, nucleosynthesis constraints on the neutral pion
lifetime fix a minimum necessary coupling between the new multiplet and the
Standard Model. The spectrum is predicted to be not a line but a box with a
width of order a few GeV, smaller than but on the order of the Fermi-LAT
resolution.
| [
{
"created": "Wed, 5 Sep 2012 20:00:02 GMT",
"version": "v1"
},
{
"created": "Sat, 3 Aug 2013 18:06:32 GMT",
"version": "v2"
}
] | 2013-08-21 | [
[
"Fan",
"JiJi",
""
],
[
"Reece",
"Matthew",
""
]
] | Recently evidence for gamma ray lines at energies of approximately 111 and 128 GeV has been found in Fermi-LAT data from the center of the galaxy and from unassociated point sources. Many explanations in terms of dark matter particle pairs annihilating to gamma gamma and gamma Z have been suggested, but these typically require very large couplings or mysterious coincidences in the masses of several new particles to fit the signal strength. We propose a simple novel explanation in which dark matter is part of a multiplet of new states which all have mass near 260 GeV as a result of symmetry. Two dark matter particles annihilate to a pair of neutral particles in this multiplet which subsequently decay to gamma gamma and gamma Z. For example, one may have a triplet of pseudo-Nambu-Goldstone bosons, charged pions and a neutral pion, where the charged pions are stabilized by their charge under a new U(1) symmetry and the slightly lighter neutral pion state decays to gamma gamma and gamma Z. The symmetry structure of such a model explains the near degeneracy in masses needed for the resulting photons to have a line-like shape and the large observed flux. The tunable lifetime of the neutral state allows such models to go unseen at direct detection or collider experiments that can constrain most other explanations. However, nucleosynthesis constraints on the neutral pion lifetime fix a minimum necessary coupling between the new multiplet and the Standard Model. The spectrum is predicted to be not a line but a box with a width of order a few GeV, smaller than but on the order of the Fermi-LAT resolution. |
hep-ph/0502180 | Claude R. V. Bourrely | Claude Bourrely (CPT), Jacques Soffer (CPT), Franco Buccella (UNIV.
NAPLES) | The statistical parton distributions: status and prospects | 34 pages, 23 figures, references and figures added | Eur.Phys.J.C41:327-341,2005 | 10.1140/epjc/s2005-02205-2 | null | hep-ph | null | New experimental results on polarized structure functions, cross sections for
$e^{\pm}p$ neutral and charge current reactions and $\nu$ ($\bar{\nu}$) charge
current on isoscalar targets are compared with predictions using the
statistical parton distributions, which were previously determined. New data on
cross sections for Drell-Yan processes, single jet in $p\bar{p}$ collisions and
inclusive $\pi^0$ production in $pp$ collisions are also compared with
predictions from this theoretical approach. The good agreement which we find
with all these tests against experiment, strenghtens our opinion on the
relevance of the role of quantum statistics for parton distributions. We will
also discuss the prospects of this physical framework.
| [
{
"created": "Sat, 19 Feb 2005 13:52:00 GMT",
"version": "v1"
},
{
"created": "Fri, 18 Mar 2005 10:51:11 GMT",
"version": "v2"
}
] | 2011-09-13 | [
[
"Bourrely",
"Claude",
"",
"CPT"
],
[
"Soffer",
"Jacques",
"",
"CPT"
],
[
"Buccella",
"Franco",
"",
"UNIV.\n NAPLES"
]
] | New experimental results on polarized structure functions, cross sections for $e^{\pm}p$ neutral and charge current reactions and $\nu$ ($\bar{\nu}$) charge current on isoscalar targets are compared with predictions using the statistical parton distributions, which were previously determined. New data on cross sections for Drell-Yan processes, single jet in $p\bar{p}$ collisions and inclusive $\pi^0$ production in $pp$ collisions are also compared with predictions from this theoretical approach. The good agreement which we find with all these tests against experiment, strenghtens our opinion on the relevance of the role of quantum statistics for parton distributions. We will also discuss the prospects of this physical framework. |
hep-ph/0606111 | Mauro Mezzetto | A.Blondel, A.Cervera-Villanueva, A.Donini, P.Huber, M.Mezzetto,
P.Strolin | Future neutrino oscillation facilities | Originally written for the CERN Strategy Group | Acta Phys.Polon.B37:2077-2113,2006 | null | null | hep-ph | null | The recent discovery that neutrinos have masses opens a wide new field of
experimentation. Accelerator-made neutrinos are essential in this program.
Ideas for future facilities include high intensity muon neutrino beams from
pion decay (`SuperBeam'), electron neutrino beams from nuclei decays (`Beta
Beam'), or muon and electron neutrino beams from muon decay (`Neutrino
Factory'), each associated with one or several options for detector systems.
Each option offers synergetic possibilities, e.g. some of the detectors can be
used for proton decay searches, while the Neutrino Factory is a first step
towards muon colliders.
A summary of the perceived virtues and shortcomings of the various options,
and a number of open questions are presented.
| [
{
"created": "Fri, 9 Jun 2006 15:52:26 GMT",
"version": "v1"
}
] | 2016-09-06 | [
[
"Blondel",
"A.",
""
],
[
"Cervera-Villanueva",
"A.",
""
],
[
"Donini",
"A.",
""
],
[
"Huber",
"P.",
""
],
[
"Mezzetto",
"M.",
""
],
[
"Strolin",
"P.",
""
]
] | The recent discovery that neutrinos have masses opens a wide new field of experimentation. Accelerator-made neutrinos are essential in this program. Ideas for future facilities include high intensity muon neutrino beams from pion decay (`SuperBeam'), electron neutrino beams from nuclei decays (`Beta Beam'), or muon and electron neutrino beams from muon decay (`Neutrino Factory'), each associated with one or several options for detector systems. Each option offers synergetic possibilities, e.g. some of the detectors can be used for proton decay searches, while the Neutrino Factory is a first step towards muon colliders. A summary of the perceived virtues and shortcomings of the various options, and a number of open questions are presented. |
hep-ph/9703408 | Yu-Ping Kuang | Shu-Quan Nie, Yu-Ping Kuang, Qing Wang, Yu-Ping Yi | Nonperturbative Explanation of the Enhancement Factors in QCD Sum Rule
for the rho Meson | 17 pages in RevTex with 5 figures | Phys. Rev. D 56, 1489 (1997) | 10.1103/PhysRevD.56.1489 | TUIMP-TH-97/80 | hep-ph | null | Taking the sum rule for the rho meson as an example, we study the possibility
of explaining the phenomenological enhamcement factors for certain terms in the
vacuum expectation value of the operator product expansion in the QCD sum rule.
We take a QCD motivated extended Nambu-Jona-Lasinio (ENJL) model as the low
energy effective Lagrangian for QCD with which we calculate the nonperturbative
contributions to the vacuum condensate expansion to obtain the enhancement
factors. Our result shows that such nonperturbative contributions can cause
large enough enhancement factors which can be consistent with the
phenomenological values.
| [
{
"created": "Tue, 25 Mar 1997 17:45:18 GMT",
"version": "v1"
},
{
"created": "Thu, 27 Mar 1997 01:47:42 GMT",
"version": "v2"
}
] | 2016-08-24 | [
[
"Nie",
"Shu-Quan",
""
],
[
"Kuang",
"Yu-Ping",
""
],
[
"Wang",
"Qing",
""
],
[
"Yi",
"Yu-Ping",
""
]
] | Taking the sum rule for the rho meson as an example, we study the possibility of explaining the phenomenological enhamcement factors for certain terms in the vacuum expectation value of the operator product expansion in the QCD sum rule. We take a QCD motivated extended Nambu-Jona-Lasinio (ENJL) model as the low energy effective Lagrangian for QCD with which we calculate the nonperturbative contributions to the vacuum condensate expansion to obtain the enhancement factors. Our result shows that such nonperturbative contributions can cause large enough enhancement factors which can be consistent with the phenomenological values. |
hep-ph/0604165 | Gerhard Ecker | Gerhard Ecker | Quantum Chromodynamics | 48 pages, 28 figures. Lectures given at the 2005 European School of
High-Energy Physics, Kitzbuehel, Austria, Aug. 21 - Sept. 3, 2005; to appear
in the Proceedings (CERN Yellow Report) | null | null | UWThPh-2006-9 | hep-ph hep-ex | null | After a brief historical review of the emergence of QCD as the quantum field
theory of strong interactions, the basic notions of colour and gauge invariance
are introduced leading to the QCD Lagrangian. The second lecture is devoted to
perturbative QCD, from tree-level processes to higher-order corrections in
renormalized perturbation theory, including jet production in e+ e-
annihilation, hadronic tau decays and deep inelastic scattering. The final two
lectures treat various aspects of QCD beyond perturbation theory. The main
theme is effective field theories, from heavy quarks to the light quark sector
where the spontaneously broken chiral symmetry of QCD plays a crucial role.
| [
{
"created": "Wed, 19 Apr 2006 13:21:17 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Ecker",
"Gerhard",
""
]
] | After a brief historical review of the emergence of QCD as the quantum field theory of strong interactions, the basic notions of colour and gauge invariance are introduced leading to the QCD Lagrangian. The second lecture is devoted to perturbative QCD, from tree-level processes to higher-order corrections in renormalized perturbation theory, including jet production in e+ e- annihilation, hadronic tau decays and deep inelastic scattering. The final two lectures treat various aspects of QCD beyond perturbation theory. The main theme is effective field theories, from heavy quarks to the light quark sector where the spontaneously broken chiral symmetry of QCD plays a crucial role. |
0807.3701 | Kouhei Hasegawa | K. Hasegawa, S. Moch, P. Uwer | Automating dipole subtraction | Latex, 6 pages, 1 figure. To appear in the proceedings of `Loops and
Legs in Quantum Field Theory', April 2008, Sondershausen, Germany | Nucl.Phys.Proc.Suppl.183:268-273,2008 | 10.1016/j.nuclphysbps.2008.09.115 | DESY 08-102, TTP 08-31, SFB/CPP-08-52 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We report on automating the Catani-Seymour dipole subtraction which is a
general procedure to treat infrared divergences in real emission processes at
next-to-leading order in QCD. The automatization rests on three essential
steps: the creation of the dipole terms, the calculation of the color linked
squared Born matrix elements, and the evaluation of different helicity
amplitudes. The routines have been tested for a number of complex processes,
such as the real emission process gg --> t anti-t ggg.
| [
{
"created": "Wed, 23 Jul 2008 15:40:05 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Hasegawa",
"K.",
""
],
[
"Moch",
"S.",
""
],
[
"Uwer",
"P.",
""
]
] | We report on automating the Catani-Seymour dipole subtraction which is a general procedure to treat infrared divergences in real emission processes at next-to-leading order in QCD. The automatization rests on three essential steps: the creation of the dipole terms, the calculation of the color linked squared Born matrix elements, and the evaluation of different helicity amplitudes. The routines have been tested for a number of complex processes, such as the real emission process gg --> t anti-t ggg. |
1304.5119 | Hamish Silverwood | Chiara Arina, Gianfranco Bertone and Hamish Silverwood | Complementarity of direct and indirect Dark Matter detection experiments | 16 pages, 5 figures. V2: matches version accepted for publication | null | 10.1103/PhysRevD.88.013002 | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the prospects for reconstructing the mass, spin-independent
and spin-dependent cross-sections of Dark Matter particles with a combination
of future direct detection experiments such as XENON1T, and the IceCube
neutrino telescope in the 86-string configuration including the DeepCore array.
We quantify the degree of complementarity between the two experiments by
adopting realistic values for their exposure, energy threshold and resolution.
Starting from benchmark models arising from a supersymmetric model with 25 free
parameters, we show that despite the stringent constraints set by the run with
79 strings, IceCube can help break the degeneracies in the Dark Matter
cross-section parameter space, even in the unfortunate case where it fails to
discover high energy neutrinos from the Sun. We also discuss how the
reconstruction of the Dark Matter particle parameters from the combined data
sets is affected by the uncertainties associated with the nuclear structure of
the target material in case of spin-dependent scattering and those associated
with astrophysical quantities such as the Dark Matter density and velocity
distribution.
| [
{
"created": "Thu, 18 Apr 2013 13:23:29 GMT",
"version": "v1"
},
{
"created": "Mon, 1 Jul 2013 15:55:30 GMT",
"version": "v2"
}
] | 2013-08-09 | [
[
"Arina",
"Chiara",
""
],
[
"Bertone",
"Gianfranco",
""
],
[
"Silverwood",
"Hamish",
""
]
] | We investigate the prospects for reconstructing the mass, spin-independent and spin-dependent cross-sections of Dark Matter particles with a combination of future direct detection experiments such as XENON1T, and the IceCube neutrino telescope in the 86-string configuration including the DeepCore array. We quantify the degree of complementarity between the two experiments by adopting realistic values for their exposure, energy threshold and resolution. Starting from benchmark models arising from a supersymmetric model with 25 free parameters, we show that despite the stringent constraints set by the run with 79 strings, IceCube can help break the degeneracies in the Dark Matter cross-section parameter space, even in the unfortunate case where it fails to discover high energy neutrinos from the Sun. We also discuss how the reconstruction of the Dark Matter particle parameters from the combined data sets is affected by the uncertainties associated with the nuclear structure of the target material in case of spin-dependent scattering and those associated with astrophysical quantities such as the Dark Matter density and velocity distribution. |
hep-ph/9309261 | Leandros Perivolaropoulos | Leandros Perivolaropoulos (Harvard-Smithsonian CfA) | Existence of Double Vortex Solutions | 10 pages plus 2 figures, use latex. To appear in Phys. Lett. B.
Preprint No. CfA-3702 | Phys.Lett. B316 (1993) 528-533 | 10.1016/0370-2693(93)91039-P | null | hep-ph astro-ph | null | We show analytically and numerically the existence of double vortex solutions
in two-Higgs systems. These solutions are generalizations of the \no vortices
and exist for all values of the parameters in the Lagrangians considered.
We derive analytically the asymptotic behavior of the solutions and confirm
it numerically by solving the field equations.
Finally, we show that these solutions can be embedded in realistic theories
like the two-doublet extension of the standard model.
| [
{
"created": "Tue, 14 Sep 1993 15:19:26 GMT",
"version": "v1"
}
] | 2009-10-22 | [
[
"Perivolaropoulos",
"Leandros",
"",
"Harvard-Smithsonian CfA"
]
] | We show analytically and numerically the existence of double vortex solutions in two-Higgs systems. These solutions are generalizations of the \no vortices and exist for all values of the parameters in the Lagrangians considered. We derive analytically the asymptotic behavior of the solutions and confirm it numerically by solving the field equations. Finally, we show that these solutions can be embedded in realistic theories like the two-doublet extension of the standard model. |
1209.4081 | Shaouly Bar-Shalom | Michael Geller, Shaouly Bar-Shalom, Gad Eilam, Amarjit Soni | The 125 GeV Higgs in the context of four generations with 2 Higgs
doublets | 9 pages, 9 figures, version as published in PRD | null | 10.1103/PhysRevD.86.115008 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We interpret the recent discovery of a 125 GeV Higgs-like state in the
context of a two Higgs doublets model with a heavy 4th sequential generation of
fermions, in which one Higgs doublet couples only to the 4th generation
fermions, while the second doublet couples to the lighter fermions of the
1st-3rd families. This model is designed to accommodate the apparent heaviness
of the 4th generation fermions and to effectively address the low-energy
phenomenology of a dynamical electroweak symmetry breaking scenario. The
physical Higgs states of the model are, therefore, viewed as composites
primarily of the 4th generation fermions. We find that the lightest Higgs, h,
is a good candidate for the recently discovered 125 GeV spin-zero particle,
when tan\beta ~ O(1), for typical 4th generation fermion masses of M_{4G} = 400
-600 GeV, and with a large t - t' mixing in the right-handed quarks sector.
This, in turn, leads to BR(t' -> t h) ~ O(1), which drastically changes the t'
decay pattern. We also find that, based on the current Higgs data, this two
Higgs doublet model generically predicts an enhanced production rate (compared
to the SM) in the pp -> h -> tau tau channel and a reduced VV -> h -> gamma
gamma and pp -> V -> Vh -> Vbb ones. Finally, the heavier CP-even Higgs is
excluded by the current data up to m_H ~ 500 GeV, while the pseudoscalar state,
A, can be as light as 130 GeV. These heavier Higgs states and the expected
deviations from the SM in some of the Higgs production channels can be further
excluded or discovered with more data.
| [
{
"created": "Tue, 18 Sep 2012 20:00:01 GMT",
"version": "v1"
},
{
"created": "Sun, 12 Jan 2014 20:03:10 GMT",
"version": "v2"
}
] | 2014-01-14 | [
[
"Geller",
"Michael",
""
],
[
"Bar-Shalom",
"Shaouly",
""
],
[
"Eilam",
"Gad",
""
],
[
"Soni",
"Amarjit",
""
]
] | We interpret the recent discovery of a 125 GeV Higgs-like state in the context of a two Higgs doublets model with a heavy 4th sequential generation of fermions, in which one Higgs doublet couples only to the 4th generation fermions, while the second doublet couples to the lighter fermions of the 1st-3rd families. This model is designed to accommodate the apparent heaviness of the 4th generation fermions and to effectively address the low-energy phenomenology of a dynamical electroweak symmetry breaking scenario. The physical Higgs states of the model are, therefore, viewed as composites primarily of the 4th generation fermions. We find that the lightest Higgs, h, is a good candidate for the recently discovered 125 GeV spin-zero particle, when tan\beta ~ O(1), for typical 4th generation fermion masses of M_{4G} = 400 -600 GeV, and with a large t - t' mixing in the right-handed quarks sector. This, in turn, leads to BR(t' -> t h) ~ O(1), which drastically changes the t' decay pattern. We also find that, based on the current Higgs data, this two Higgs doublet model generically predicts an enhanced production rate (compared to the SM) in the pp -> h -> tau tau channel and a reduced VV -> h -> gamma gamma and pp -> V -> Vh -> Vbb ones. Finally, the heavier CP-even Higgs is excluded by the current data up to m_H ~ 500 GeV, while the pseudoscalar state, A, can be as light as 130 GeV. These heavier Higgs states and the expected deviations from the SM in some of the Higgs production channels can be further excluded or discovered with more data. |
hep-ph/0105327 | Jonathan L. Rosner | Jonathan L. Rosner | Charmless Final States and S--D-wave mixing in the $\psi''$ | 11 pages, LaTeX, no figures, to be submitted to Phys. Rev. D. New
discussions and references added | Phys.Rev.D64:094002,2001 | 10.1103/PhysRevD.64.094002 | EFI 01-14 | hep-ph | null | The $\ppp = \psi(3770)$ resonance is expected to be mainly $c \bar
c(1^3D_1)$, but tensor forces and coupling to charmed particle pairs can mix it
with $\pp(2^3S_1)$ and other states. Implications of this mixing for decays of
$\ppp$ to non-charmed final states are discussed. (i) The ratio $\Gamma(\ppp
\to \gamma + \chi_{c2})/ \Gamma(\ppp \to \gamma + \chi_{c0})$ is expected to be
highly suppressed if $\ppp$ is a pure D-wave state, and is enchanced by mixing.
(ii) The expected decay $\pp \to \rho \pi$ and other ``missing'' modes can
appear as corresponding $\ppp$ partial widths, enhanced by a factor depending
on the mixing angle. General arguments then suggest a branching ratio of about
1%, give or take a factor of 2, for charmless hadronic decays of $\ppp$. (iii)
Enhancements can appear in penguin amplitudes in B decays, $B \to K \eta'$
branching ratios, and direct CP-violating asymmetries in $B \to K \pi$ decays.
| [
{
"created": "Wed, 30 May 2001 20:44:57 GMT",
"version": "v1"
},
{
"created": "Tue, 5 Jun 2001 22:29:59 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"Rosner",
"Jonathan L.",
""
]
] | The $\ppp = \psi(3770)$ resonance is expected to be mainly $c \bar c(1^3D_1)$, but tensor forces and coupling to charmed particle pairs can mix it with $\pp(2^3S_1)$ and other states. Implications of this mixing for decays of $\ppp$ to non-charmed final states are discussed. (i) The ratio $\Gamma(\ppp \to \gamma + \chi_{c2})/ \Gamma(\ppp \to \gamma + \chi_{c0})$ is expected to be highly suppressed if $\ppp$ is a pure D-wave state, and is enchanced by mixing. (ii) The expected decay $\pp \to \rho \pi$ and other ``missing'' modes can appear as corresponding $\ppp$ partial widths, enhanced by a factor depending on the mixing angle. General arguments then suggest a branching ratio of about 1%, give or take a factor of 2, for charmless hadronic decays of $\ppp$. (iii) Enhancements can appear in penguin amplitudes in B decays, $B \to K \eta'$ branching ratios, and direct CP-violating asymmetries in $B \to K \pi$ decays. |
hep-ph/0306166 | Jan van Leusen | L.M. Sehgal | Right-handed Electrons in Radiative Muon Decay | 8pages, 2 figures; v2: small correction in para (ii) of summary | Phys.Lett. B569 (2003) 25-29 | 10.1016/j.physletb.2003.07.016 | null | hep-ph | null | Electrons emitted in the radiative decay mu^- -> e^- anti-nu_e nu_mu gamma
have a significant probability of being right-handed, even in the limit m_e ->
0. Such ``wrong-helicity'' electrons, arising from helicity-flip
bremsstrahlung, contribute an amount alpha/(4 pi) Gamma_0 to the muon decay
width (Gamma_0 = G_F^2 m^5_mu/ (192 pi^3)). We use the helicity-flip splitting
function D_hf (z) of Falk and Sehgal (Phys. Lett. B 325, 509 (1994)) to obtain
the spectrum of the right-handed electrons and the photons that accompany them.
For a minimum photon energy E_gamma = 10 MeV (20 MeV), approximately 4% (7%) of
electrons in radiative mu-decay are right-handed.
| [
{
"created": "Wed, 18 Jun 2003 14:02:27 GMT",
"version": "v1"
},
{
"created": "Mon, 23 Jun 2003 10:39:36 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Sehgal",
"L. M.",
""
]
] | Electrons emitted in the radiative decay mu^- -> e^- anti-nu_e nu_mu gamma have a significant probability of being right-handed, even in the limit m_e -> 0. Such ``wrong-helicity'' electrons, arising from helicity-flip bremsstrahlung, contribute an amount alpha/(4 pi) Gamma_0 to the muon decay width (Gamma_0 = G_F^2 m^5_mu/ (192 pi^3)). We use the helicity-flip splitting function D_hf (z) of Falk and Sehgal (Phys. Lett. B 325, 509 (1994)) to obtain the spectrum of the right-handed electrons and the photons that accompany them. For a minimum photon energy E_gamma = 10 MeV (20 MeV), approximately 4% (7%) of electrons in radiative mu-decay are right-handed. |
1807.05876 | Stefan Dittmaier | Lukas Altenkamp, Michele Boggia, Stefan Dittmaier, Heidi Rzehak | Electroweak corrections in the Two-Higgs-Doublet Model and a Singlet
Extension of the Standard Model | 8 pages, 4 figures, to appear in the Proceedings of the conference
"Loops and Legs in Quantum Field Theory (LL2018)", 29 April 2018 - 04 May
2018, St. Goar, Germany. arXiv admin note: text overlap with arXiv:1802.00419 | null | null | FR-PHENO-2018-006 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the next-to-leading-order calculation of the partial decay widths
of light CP-even Higgs bosons decaying into four fermions in the
Two-Higgs-Doublet Model and a Singlet Extension of the Standard Model.
Different renormalization schemes are applied in the calculation, which is
implemented into the analysis tool PROPHECY4F. Some sample results on the
Higgs->4fermions decay widths illustrate how the corrections reduce the
dependence on the renormalization scale and the choice of the scheme.
| [
{
"created": "Fri, 13 Jul 2018 13:36:52 GMT",
"version": "v1"
}
] | 2018-07-17 | [
[
"Altenkamp",
"Lukas",
""
],
[
"Boggia",
"Michele",
""
],
[
"Dittmaier",
"Stefan",
""
],
[
"Rzehak",
"Heidi",
""
]
] | We present the next-to-leading-order calculation of the partial decay widths of light CP-even Higgs bosons decaying into four fermions in the Two-Higgs-Doublet Model and a Singlet Extension of the Standard Model. Different renormalization schemes are applied in the calculation, which is implemented into the analysis tool PROPHECY4F. Some sample results on the Higgs->4fermions decay widths illustrate how the corrections reduce the dependence on the renormalization scale and the choice of the scheme. |
hep-ph/9708435 | null | Keith G. Richardson, Michael C. Birse, Judith A. McGovern (University
of Manchester) | Renormalisation and power counting in effective field theories for
nucleon-nucleon scattering | 4 pages (RevTeX) | null | null | MC/TH 97/13 | hep-ph | null | The renormalisation of NN scattering in theories with zero-range interactions
is examined using a cut-off regularisation and taking the cut-off to infinity.
Inclusion of contact interactions that depend on energy as well as momentum
allows the effective range to be fitted to experiment with any desired sign or
magnitude. However, power counting breaks down: terms of different orders in
the potential can contribute to the scattering amplitude at the same order.
| [
{
"created": "Fri, 22 Aug 1997 10:59:55 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Richardson",
"Keith G.",
"",
"University\n of Manchester"
],
[
"Birse",
"Michael C.",
"",
"University\n of Manchester"
],
[
"McGovern",
"Judith A.",
"",
"University\n of Manchester"
]
] | The renormalisation of NN scattering in theories with zero-range interactions is examined using a cut-off regularisation and taking the cut-off to infinity. Inclusion of contact interactions that depend on energy as well as momentum allows the effective range to be fitted to experiment with any desired sign or magnitude. However, power counting breaks down: terms of different orders in the potential can contribute to the scattering amplitude at the same order. |
hep-ph/0505147 | Redamy Perez Ramos | Redamy Perez Ramos (LPTHE) | Correlations between two particles in jets | 4 pages, 7 figures, Rencontres de Moriond 2005 "QCD and Hadronic
interactions" | null | null | null | hep-ph | null | We study the correlation between two soft particles in QCD jets. We extend
the Fong--Webber analysis to the region away from the hump in the single
inclusive energy spectrum and show that the correlation function should flatten
off and then decrease for large values of l=ln(1/x).
| [
{
"created": "Tue, 17 May 2005 07:11:10 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Ramos",
"Redamy Perez",
"",
"LPTHE"
]
] | We study the correlation between two soft particles in QCD jets. We extend the Fong--Webber analysis to the region away from the hump in the single inclusive energy spectrum and show that the correlation function should flatten off and then decrease for large values of l=ln(1/x). |
2006.16416 | Anna Hallin | Pouya Asadi, Anna Hallin, Jorge Martin Camalich, David Shih, Susanne
Westhoff | A Complete Framework for Tau Polarimetry in $B\to D^{(*)}\tau\nu$ Decays | 20 pages + appendices, 5 figures | null | 10.1103/PhysRevD.102.095028 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The meson decays $B\to D\tau\nu$ and $B\to D^* \tau \nu$ are sensitive probes
of the $b\to c\tau\nu$ transition. In this work we present a complete framework
to obtain the maximum information on the physics of $B\to D^{(*)}\tau\nu$ with
polarized $\tau$ leptons and unpolarized $D^{(*)}$ mesons. Focusing on the
hadronic decays $\tau\to \pi\nu$ and $\tau\to\rho\nu$, we show how to extract
seven $\tau$ asymmetries from a fully differential analysis of the final-state
kinematics. At Belle II with $50~\text{ab}^{-1}$ of data, these asymmetries
could potentially be measured with percent level statistical uncertainty. This
would open a new window into possible new physics contributions in $b\to
c\tau\nu$ and would allow us to decipher its Lorentz and gauge structure.
| [
{
"created": "Mon, 29 Jun 2020 22:20:09 GMT",
"version": "v1"
}
] | 2020-12-30 | [
[
"Asadi",
"Pouya",
""
],
[
"Hallin",
"Anna",
""
],
[
"Camalich",
"Jorge Martin",
""
],
[
"Shih",
"David",
""
],
[
"Westhoff",
"Susanne",
""
]
] | The meson decays $B\to D\tau\nu$ and $B\to D^* \tau \nu$ are sensitive probes of the $b\to c\tau\nu$ transition. In this work we present a complete framework to obtain the maximum information on the physics of $B\to D^{(*)}\tau\nu$ with polarized $\tau$ leptons and unpolarized $D^{(*)}$ mesons. Focusing on the hadronic decays $\tau\to \pi\nu$ and $\tau\to\rho\nu$, we show how to extract seven $\tau$ asymmetries from a fully differential analysis of the final-state kinematics. At Belle II with $50~\text{ab}^{-1}$ of data, these asymmetries could potentially be measured with percent level statistical uncertainty. This would open a new window into possible new physics contributions in $b\to c\tau\nu$ and would allow us to decipher its Lorentz and gauge structure. |
2207.06798 | Monojit Ghosh | Deepak Raikwal, Sandhya Choubey, Monojit Ghosh | Determining Neutrino Mass Ordering with ICAL, JUNO and T2HK | 17 pages, 10 figures, 8 tables, Published in Eur. Phys. J. Plus | Eur. Phys. J. Plus 138 (2023), 110 | 10.1140/epjp/s13360-023-03697-9 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper we study the synergy among the future accelerator (T2HK),
future atmospheric (ICAL) and future reactor (JUNO) neutrino experiments to
determine the neutrino mass ordering. T2HK can measure the mass ordering only
for favorable values of $\delta_{\rm CP}$, whereas the mass ordering
sensitivity of JUNO is dependent on the energy resolution. Our results show
that with a combination of T2HK, ICAL and JUNO one can have a mass ordering
sensitivity of 7.2 $\sigma$ even for the unfavorable value of $\delta_{\rm CP}
= 0^\circ$ for T2HK and most conservative value of JUNO energy resolution of
5$\%/\sqrt{E(MeV)}$. The synergy mainly comes because different oscillation
channels prefer different values of $|\Delta m_{31}^2|$ in the fit when the
mass-ordering $\chi^2$ is minimized. In this context we also study: (i) effect
of varying energy resolution of JUNO, (ii) the effect of longer run-time of
ICAL, (iii) effect of different true values of $\theta_{23}$ and (iv) effect of
octant degeneracy in the determination of neutrino mass ordering.
| [
{
"created": "Thu, 14 Jul 2022 10:23:07 GMT",
"version": "v1"
},
{
"created": "Mon, 6 Feb 2023 12:28:09 GMT",
"version": "v2"
}
] | 2023-02-07 | [
[
"Raikwal",
"Deepak",
""
],
[
"Choubey",
"Sandhya",
""
],
[
"Ghosh",
"Monojit",
""
]
] | In this paper we study the synergy among the future accelerator (T2HK), future atmospheric (ICAL) and future reactor (JUNO) neutrino experiments to determine the neutrino mass ordering. T2HK can measure the mass ordering only for favorable values of $\delta_{\rm CP}$, whereas the mass ordering sensitivity of JUNO is dependent on the energy resolution. Our results show that with a combination of T2HK, ICAL and JUNO one can have a mass ordering sensitivity of 7.2 $\sigma$ even for the unfavorable value of $\delta_{\rm CP} = 0^\circ$ for T2HK and most conservative value of JUNO energy resolution of 5$\%/\sqrt{E(MeV)}$. The synergy mainly comes because different oscillation channels prefer different values of $|\Delta m_{31}^2|$ in the fit when the mass-ordering $\chi^2$ is minimized. In this context we also study: (i) effect of varying energy resolution of JUNO, (ii) the effect of longer run-time of ICAL, (iii) effect of different true values of $\theta_{23}$ and (iv) effect of octant degeneracy in the determination of neutrino mass ordering. |
hep-ph/9609465 | Leutwyler Heinrich | H. Leutwyler (University of Bern and CERN) | Light Quark Effective Theory | 30 pages, 3 postscript figures | null | null | null | hep-ph | null | Lecture Notes, Summer School on Effective Theories and Fundamental
Interactions, Erice, 1996. The application of effective field theory methods to
the low energy structure of QCD is discussed. I emphasize the universal
structure of the corresponding effective Lagrangian and then discuss the
physics of the effective coupling constants. The implications of the effective
theory for the masses of the light quarks are analyzed in some detail.
| [
{
"created": "Wed, 25 Sep 1996 10:03:43 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Leutwyler",
"H.",
"",
"University of Bern and CERN"
]
] | Lecture Notes, Summer School on Effective Theories and Fundamental Interactions, Erice, 1996. The application of effective field theory methods to the low energy structure of QCD is discussed. I emphasize the universal structure of the corresponding effective Lagrangian and then discuss the physics of the effective coupling constants. The implications of the effective theory for the masses of the light quarks are analyzed in some detail. |
hep-ph/0012282 | Christian Fischer | S. Ahlig, R. Alkofer, C. Fischer, M. Oettel, H. Reinhardt, and H.
Weigel | Production Processes as a Tool to Study Parameterizations of Quark
Confinement | 43 pages, Latex, 28 eps files included via epsfig; version to be
published in Physical Review D | Phys.Rev.D64:014004,2001 | 10.1103/PhysRevD.64.014004 | UNITU--THEP--18/2000 | hep-ph nucl-th | null | We introduce diquarks as separable correlations in the two-quark Green's
function to facilitate the description of baryons as relativistic three-quark
bound states. These states then emerge as solutions of Bethe-Salpeter equations
for quarks and diquarks that interact via quark exchange. When solving these
equations we consider various dressing functions for the free quark and diquark
propagators that prohibit the existence of corresponding asymptotic states and
thus effectively parameterize confinement. We study the implications of
qualitatively different dressing functions on the model predictions for the
masses of the octet baryons as well as the electromagnetic and strong form
factors of the nucleon. For different dressing functions we in particular
compare the predictions for kaon photoproduction, $\gamma p\to K\Lambda$, and
associated strangeness production, $pp\to pK\Lambda$ with experimental data.
This leads to conclusions on the permissibility of different dressing
functions.
| [
{
"created": "Thu, 21 Dec 2000 09:51:47 GMT",
"version": "v1"
},
{
"created": "Fri, 16 Mar 2001 10:27:07 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Ahlig",
"S.",
""
],
[
"Alkofer",
"R.",
""
],
[
"Fischer",
"C.",
""
],
[
"Oettel",
"M.",
""
],
[
"Reinhardt",
"H.",
""
],
[
"Weigel",
"H.",
""
]
] | We introduce diquarks as separable correlations in the two-quark Green's function to facilitate the description of baryons as relativistic three-quark bound states. These states then emerge as solutions of Bethe-Salpeter equations for quarks and diquarks that interact via quark exchange. When solving these equations we consider various dressing functions for the free quark and diquark propagators that prohibit the existence of corresponding asymptotic states and thus effectively parameterize confinement. We study the implications of qualitatively different dressing functions on the model predictions for the masses of the octet baryons as well as the electromagnetic and strong form factors of the nucleon. For different dressing functions we in particular compare the predictions for kaon photoproduction, $\gamma p\to K\Lambda$, and associated strangeness production, $pp\to pK\Lambda$ with experimental data. This leads to conclusions on the permissibility of different dressing functions. |
hep-ph/9301241 | null | P.Colangelo, F.De Fazio and G.Nardulli | Study of the Reactions $B \to D^* \pi \pi$ and $B \to D^* \rho \pi$ | 9 pages, LaTex, BARI-TH/92-131 | Phys.Lett. B303 (1993) 152-156 | 10.1016/0370-2693(93)90060-U | null | hep-ph | null | We evaluate the non leptonic decays $B \to D^* \pi \pi$ and $B \to D^* \rho
\pi$ in the limit of infinitely heavy quarks, assuming the dominance of
intermediate positive parity charmed resonances. We find that the branching
ratios are of the order $10^(-3)$.
| [
{
"created": "Fri, 15 Jan 1993 12:38:00 GMT",
"version": "v1"
}
] | 2009-10-22 | [
[
"Colangelo",
"P.",
""
],
[
"De Fazio",
"F.",
""
],
[
"Nardulli",
"G.",
""
]
] | We evaluate the non leptonic decays $B \to D^* \pi \pi$ and $B \to D^* \rho \pi$ in the limit of infinitely heavy quarks, assuming the dominance of intermediate positive parity charmed resonances. We find that the branching ratios are of the order $10^(-3)$. |
hep-ph/0005203 | Alessandro Strumia | Riccardo Barbieri and Alessandro Strumia | Relating m_Higgs to m_SUSY by a loop factor | 3 pages, 1 fig | Phys.Lett.B490:247-250,2000 | 10.1016/S0370-2693(00)00980-1 | IFUP-TH/2000-14 | hep-ph | null | We assume that the scale of the soft supersymmetry breaking masses, m_SUSY,
sliding at tree level, is fixed by the minimization of the potential, but
without a significant contribution of the cosmological term. Under these
assumptions the electroweak breaking scale gets related to m_SUSY by a loop
factor. Applied to specific models of supersymmetry breaking, this mechanism
naturally gives sparticles slightly above all present accelerator bounds.
| [
{
"created": "Fri, 19 May 2000 13:32:48 GMT",
"version": "v1"
}
] | 2009-10-09 | [
[
"Barbieri",
"Riccardo",
""
],
[
"Strumia",
"Alessandro",
""
]
] | We assume that the scale of the soft supersymmetry breaking masses, m_SUSY, sliding at tree level, is fixed by the minimization of the potential, but without a significant contribution of the cosmological term. Under these assumptions the electroweak breaking scale gets related to m_SUSY by a loop factor. Applied to specific models of supersymmetry breaking, this mechanism naturally gives sparticles slightly above all present accelerator bounds. |
1205.5207 | Fl. Stancu | N. Matagne and Fl. Stancu | Highly excited negative parity baryons in the $1/N_c$ expansion | 15 pages, accepted for publication in Phys.Rev.D | null | 10.1103/PhysRevD.85.116003 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The masses of experimentally known highly excited baryons of negative parity
supposed to belong to the $[{\bf 70},\ell^-]$ multiplets ($\ell$ = 1,2,3) of
the $N = 3$ band are calculated in the $1/N_c$ expansion method to order
$1/N_c$ by using a procedure which allows to considerably reduce the number of
linearly independent operators entering the mass formula. The numerical fits to
present data show that the coefficients encoding the QCD dynamics have large,
comparable values, for the flavor and spin operators. It implies that these
operators contribute dominantly to the flavor-spin SU(6) symmetry breaking,
like for the $[{\bf 70},1^-]$ multiplet of the $N = 1$ band.
| [
{
"created": "Wed, 23 May 2012 15:32:23 GMT",
"version": "v1"
}
] | 2015-06-05 | [
[
"Matagne",
"N.",
""
],
[
"Stancu",
"Fl.",
""
]
] | The masses of experimentally known highly excited baryons of negative parity supposed to belong to the $[{\bf 70},\ell^-]$ multiplets ($\ell$ = 1,2,3) of the $N = 3$ band are calculated in the $1/N_c$ expansion method to order $1/N_c$ by using a procedure which allows to considerably reduce the number of linearly independent operators entering the mass formula. The numerical fits to present data show that the coefficients encoding the QCD dynamics have large, comparable values, for the flavor and spin operators. It implies that these operators contribute dominantly to the flavor-spin SU(6) symmetry breaking, like for the $[{\bf 70},1^-]$ multiplet of the $N = 1$ band. |
1310.7901 | Aleksandra Drozd | Subhaditya Bhattacharya, Aleksandra Drozd, Bohdan Grzadkowski, Jose
Wudka | Constraints on Two-Component Dark Matter | 7 pages, 3 figures, contribution to the proceedings of the conference
"Matter To The Deepest, Recent Developments In Physics Of Fundamental
Interactions, XXXVII International Conference of Theoretical Physics" (1-6
September, Ustron, Poland), v2: typo in authors name corrected | Acta Phys.Polon. B44 (2013) 11, 2373-2379 | 10.5506/APhysPolB.44.2373 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study 'Higgs Portal' 2-component Dark Matter scenario with two interacting
cold Dark Matter (DM) candidates: a neutral scalar singlet ($\varphi$) and a
neutral Majorana fermion ($\nu$). The relic abundance of $\varphi$ and $\nu$ is
found assuming thermal DM production and solving the Boltzmann equations. We
scan over the parameter space of the model to determine regions consistent with
the WMAP data for DM relic abundance and the XENON100 direct detection limits
for the DM-nucleus cross section.
| [
{
"created": "Tue, 29 Oct 2013 18:02:30 GMT",
"version": "v1"
},
{
"created": "Sun, 3 Aug 2014 12:25:06 GMT",
"version": "v2"
}
] | 2014-08-05 | [
[
"Bhattacharya",
"Subhaditya",
""
],
[
"Drozd",
"Aleksandra",
""
],
[
"Grzadkowski",
"Bohdan",
""
],
[
"Wudka",
"Jose",
""
]
] | We study 'Higgs Portal' 2-component Dark Matter scenario with two interacting cold Dark Matter (DM) candidates: a neutral scalar singlet ($\varphi$) and a neutral Majorana fermion ($\nu$). The relic abundance of $\varphi$ and $\nu$ is found assuming thermal DM production and solving the Boltzmann equations. We scan over the parameter space of the model to determine regions consistent with the WMAP data for DM relic abundance and the XENON100 direct detection limits for the DM-nucleus cross section. |
1101.2071 | Eulogio Oset | E. Oset, D. Gamermann, R. Molina, J.M. Nieves, E. Ruiz Arriola, T.
Branz and Wei Hong Liang | The X(3872) and other X,Y,Z Resonances as Hidden Charm Meson-Meson
Molecules | Presented at the Charm2010 Workshop, Beijing, Oct. 2010 | null | 10.1142/S2010194511000523 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We report on some ideas concerning the nature of the X(3872) resonance and
the need for approximately equal charged and neutral components of $D \bar{D}^*
+cc$. Then we discuss how some hidden charm states are obtained from the
interaction between vector mesons with charm and can be associated to some of
the charmonium-like X,Y,Z states. Finally we discuss how the nature of these
states could be investigated through different types of radiative decay.
| [
{
"created": "Tue, 11 Jan 2011 09:22:17 GMT",
"version": "v1"
}
] | 2015-05-27 | [
[
"Oset",
"E.",
""
],
[
"Gamermann",
"D.",
""
],
[
"Molina",
"R.",
""
],
[
"Nieves",
"J. M.",
""
],
[
"Arriola",
"E. Ruiz",
""
],
[
"Branz",
"T.",
""
],
[
"Liang",
"Wei Hong",
""
]
] | We report on some ideas concerning the nature of the X(3872) resonance and the need for approximately equal charged and neutral components of $D \bar{D}^* +cc$. Then we discuss how some hidden charm states are obtained from the interaction between vector mesons with charm and can be associated to some of the charmonium-like X,Y,Z states. Finally we discuss how the nature of these states could be investigated through different types of radiative decay. |
0805.2202 | Yifei Zhang | Yifei Zhang | Identification of Bottom Contribution in Non-photonic Electron Spectra
and $v_2$ at RHIC | 7 pages,4 figures, 23rd Winter Workshop on Nuclear Dynamics | 23rd Winter Workshop on Nuclear Dynamics, EP Systema, Budapest,
ISBN 978 963 86934 2 6, 231, 2007 | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a study on the spectra for heavy flavor (charm and bottom) decayed
electrons in 200 GeV $p+p$ collisions and provide the relative contributions of
charm and bottom hadrons from the PYTHIA calculations. The results suggest that
the crossing point of the electron spectra from charm and bottom decays is
above 7 GeV/$c$ and bottom contribution is not dominant for electron $p_{T}<3$
GeV/$c$. The upper limit of the relative cross section ratio is reported as
$\sigma_{b\bar{b}}/\sigma_{c\bar{c}}\leq(0.49\pm0.09\pm0.09)%$. We also compare
the $v_2$ distribution from simulation to the experimental data in 200 GeV
$Au+Au$ collisions and estimate the possible charm $v_2$.
| [
{
"created": "Thu, 15 May 2008 03:06:03 GMT",
"version": "v1"
}
] | 2008-05-16 | [
[
"Zhang",
"Yifei",
""
]
] | We present a study on the spectra for heavy flavor (charm and bottom) decayed electrons in 200 GeV $p+p$ collisions and provide the relative contributions of charm and bottom hadrons from the PYTHIA calculations. The results suggest that the crossing point of the electron spectra from charm and bottom decays is above 7 GeV/$c$ and bottom contribution is not dominant for electron $p_{T}<3$ GeV/$c$. The upper limit of the relative cross section ratio is reported as $\sigma_{b\bar{b}}/\sigma_{c\bar{c}}\leq(0.49\pm0.09\pm0.09)%$. We also compare the $v_2$ distribution from simulation to the experimental data in 200 GeV $Au+Au$ collisions and estimate the possible charm $v_2$. |
2305.08525 | Rana Sumit | Sumit, Najmul Haque and Binoy Krishna Patra | QCD mesonic screening masses using Gribov quantization | null | Physics Letters B 845 (2023) 138143 | 10.1016/j.physletb.2023.138143 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | The screening masses of mesons provide a gauge invariant and definite order
parameter of chiral symmetry restoration. Different mesonic correlation lengths
for flavor non-singlets, at least up to NLO, are well-defined gauge invariant
physical quantities calculated earlier using the perturbative resummation
techniques. The NLO perturbative results match the available non-perturbative
lattice QCD results at the high-temperature regime. We have studied the spatial
correlation lengths of various mesonic observables using the non-perturbative
Gribov resummation, both for quenched QCD and (2 + 1) flavor QCD. The study
follows the analogies with the NRQCD effective theory, a well-known theory for
studying heavy quarkonia at zero temperature.
| [
{
"created": "Mon, 15 May 2023 10:32:27 GMT",
"version": "v1"
},
{
"created": "Thu, 31 Aug 2023 10:05:11 GMT",
"version": "v2"
}
] | 2023-09-04 | [
[
"Sumit",
"",
""
],
[
"Haque",
"Najmul",
""
],
[
"Patra",
"Binoy Krishna",
""
]
] | The screening masses of mesons provide a gauge invariant and definite order parameter of chiral symmetry restoration. Different mesonic correlation lengths for flavor non-singlets, at least up to NLO, are well-defined gauge invariant physical quantities calculated earlier using the perturbative resummation techniques. The NLO perturbative results match the available non-perturbative lattice QCD results at the high-temperature regime. We have studied the spatial correlation lengths of various mesonic observables using the non-perturbative Gribov resummation, both for quenched QCD and (2 + 1) flavor QCD. The study follows the analogies with the NRQCD effective theory, a well-known theory for studying heavy quarkonia at zero temperature. |
0812.1175 | Gustavo Gil da Silveira | M.B. Gay Ducati, G.G. Silveira | Higgs boson at LHC: a diffractive opportunity | 4 pages, 6 figures, contribution to the proceedings of "Diffraction
in High Energy Physics" [DIFFRACTION 2008], 9-14 Sep. 2008, La
Londe-les-Maures, France. Latex and AIP style file | null | 10.1063/1.3122174 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | An alternative process is presented for diffractive Higgs boson production in
peripheral $pp$ collisions, where the particles interact through the Double
Pomeron Exchange. The event rate is computed as a central-rapidity distribution
for Tevatron and LHC energies leading to a result around 0.6 pb, higher than
the predictions from previous approaches. Therefore, this result arises as an
enhanced signal for the detection of the Higgs boson in hadron colliders. The
predictions for the Higgs boson photoproduction are compared to the ones
obtained from a similar approach proposed by the Durham group, enabling an
analysis of the future developments of its application to $pp$ and $AA$
collisions.
| [
{
"created": "Fri, 5 Dec 2008 16:41:25 GMT",
"version": "v1"
}
] | 2009-11-13 | [
[
"Ducati",
"M. B. Gay",
""
],
[
"Silveira",
"G. G.",
""
]
] | An alternative process is presented for diffractive Higgs boson production in peripheral $pp$ collisions, where the particles interact through the Double Pomeron Exchange. The event rate is computed as a central-rapidity distribution for Tevatron and LHC energies leading to a result around 0.6 pb, higher than the predictions from previous approaches. Therefore, this result arises as an enhanced signal for the detection of the Higgs boson in hadron colliders. The predictions for the Higgs boson photoproduction are compared to the ones obtained from a similar approach proposed by the Durham group, enabling an analysis of the future developments of its application to $pp$ and $AA$ collisions. |
1907.06037 | Tommaso Giani | Krzysztof Cichy, Luigi Del Debbio and Tommaso Giani | Parton distributions from lattice data: the nonsinglet case | 26 pages, 7 figures; added references, corrected typos | null | 10.1007/JHEP10(2019)137 | null | hep-ph hep-lat | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We revise the relation between Parton Distribution Functions (PDFs) and
matrix elements computable from lattice QCD, focusing on the quasi-Parton
Distribution Functions (qPDFs) approach. We exploit the relation between PDFs
and qPDFs in the case of the unpolarized isovector parton distribution to
obtain a factorization formula relating the real and imaginary part of qPDFs
matrix elements to specific nonsinglet distributions, and we propose a general
framework to extract PDFs from the available lattice data, treating them on the
same footing as experimental data. We implement the proposed approach within
the NNPDF framework, and we study the potentiality of such lattice data in
constraining PDFs, assuming some plausible scenarios to assess the unknown
systematic uncertainties. We finally extract the two nonsinglet distributions
involved in our analysis from a selection of the available lattice data.
| [
{
"created": "Sat, 13 Jul 2019 09:40:04 GMT",
"version": "v1"
},
{
"created": "Fri, 26 Jul 2019 19:21:07 GMT",
"version": "v2"
}
] | 2020-01-08 | [
[
"Cichy",
"Krzysztof",
""
],
[
"Del Debbio",
"Luigi",
""
],
[
"Giani",
"Tommaso",
""
]
] | We revise the relation between Parton Distribution Functions (PDFs) and matrix elements computable from lattice QCD, focusing on the quasi-Parton Distribution Functions (qPDFs) approach. We exploit the relation between PDFs and qPDFs in the case of the unpolarized isovector parton distribution to obtain a factorization formula relating the real and imaginary part of qPDFs matrix elements to specific nonsinglet distributions, and we propose a general framework to extract PDFs from the available lattice data, treating them on the same footing as experimental data. We implement the proposed approach within the NNPDF framework, and we study the potentiality of such lattice data in constraining PDFs, assuming some plausible scenarios to assess the unknown systematic uncertainties. We finally extract the two nonsinglet distributions involved in our analysis from a selection of the available lattice data. |
hep-ph/9706229 | Jean-Marc Virey | J. Soffer and J.-M. Virey | Testing various polarized parton distributions at RHIC | Latex file, 12 pages and 14 ps fig. One footnote and one reference
added | Nucl.Phys. B509 (1998) 297-311 | 10.1016/S0550-3213(97)00669-X | CPT-97/P.3495 | hep-ph | null | A very promising spin physics programme will be soon on the way at the BNL
Relativistic Heavy Ion Collider (RHIC). By studying the spin asymmetries for
various processes (single photon, single-jet and $W^{\pm}$ production), we will
compare the different predictions obtained using some sets of polarized parton
distributions, available in the recent literature. We will put some emphasize
on the analysis of the anticipated errors, given the event rates expected from
this high luminosity new machine and the current acceptance for the detector
systems at RHIC.
| [
{
"created": "Tue, 3 Jun 1997 14:18:52 GMT",
"version": "v1"
},
{
"created": "Fri, 6 Jun 1997 11:19:07 GMT",
"version": "v2"
}
] | 2009-10-30 | [
[
"Soffer",
"J.",
""
],
[
"Virey",
"J. -M.",
""
]
] | A very promising spin physics programme will be soon on the way at the BNL Relativistic Heavy Ion Collider (RHIC). By studying the spin asymmetries for various processes (single photon, single-jet and $W^{\pm}$ production), we will compare the different predictions obtained using some sets of polarized parton distributions, available in the recent literature. We will put some emphasize on the analysis of the anticipated errors, given the event rates expected from this high luminosity new machine and the current acceptance for the detector systems at RHIC. |
0705.2403 | Efrain J. Ferrer | Efrain J. Ferrer and Vivian de la Incera | Chromomagnetic Instability and Induced Magnetic Field in Neutral
Two-Flavor Color Superconductivity | Version to appear in PRD | Phys.Rev.D76:114012,2007 | 10.1103/PhysRevD.76.114012 | null | hep-ph astro-ph nucl-th | null | We find that the chromomagnetic instability existing in neutral two- flavor
color superconductivity at moderate densities is removed by the formation of an
inhomogeneous condensate of charged gluons and the corresponding induction of a
magnetic field. It is shown that this inhomogeneous ground state is
energetically favored over a homogeneous one. The spontaneous induction of a
magnetic field in a color superconductor at moderate densities can be of
interest for the astrophysics of compact stellar objects exhibiting strong
magnetic fields as magnetars.
| [
{
"created": "Wed, 16 May 2007 19:36:42 GMT",
"version": "v1"
},
{
"created": "Wed, 16 May 2007 23:03:06 GMT",
"version": "v2"
},
{
"created": "Mon, 15 Oct 2007 19:54:41 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Ferrer",
"Efrain J.",
""
],
[
"de la Incera",
"Vivian",
""
]
] | We find that the chromomagnetic instability existing in neutral two- flavor color superconductivity at moderate densities is removed by the formation of an inhomogeneous condensate of charged gluons and the corresponding induction of a magnetic field. It is shown that this inhomogeneous ground state is energetically favored over a homogeneous one. The spontaneous induction of a magnetic field in a color superconductor at moderate densities can be of interest for the astrophysics of compact stellar objects exhibiting strong magnetic fields as magnetars. |
hep-ph/0109058 | Ulrich Haisch | Paolo Gambino and Ulrich Haisch | Complete electroweak matching for radiative B decays | 20 pages, 2 figures, uses amssymb.sty, amsmath.sty and feynarts.sty.
Minor changes | JHEP 0110 (2001) 020 | 10.1088/1126-6708/2001/10/020 | null | hep-ph | null | We compute the complete two-loop O(alpha) Wilson coefficients relevant for
radiative decays of the B meson in the SM. This is a necessary step in the
calculation of the O(alpha alpha_s^n ln^n m_b/M_W) corrections and improves on
our previous analysis of electroweak effects in B -> X_s gamma. We describe in
detail several interesting technical aspects of the calculation and include all
dominant QED matrix elements. In our final result, we neglect only terms
originated from the unknown O(alpha alpha_s) evolution of the Wilson
coefficients and some suppressed two-loop matrix elements. Due to the
compensation among different effects, we find that non-trivial electroweak
corrections decrease the branching ratio by about 3.6% for a light Higgs boson,
very close to our previous result. The corresponding up-to-date SM prediction
for the branching ratio with E_gamma > 1.6 GeV is (3.61 +- 0.30) x 10^-4.
| [
{
"created": "Fri, 7 Sep 2001 16:15:14 GMT",
"version": "v1"
},
{
"created": "Fri, 14 Sep 2001 13:47:38 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Gambino",
"Paolo",
""
],
[
"Haisch",
"Ulrich",
""
]
] | We compute the complete two-loop O(alpha) Wilson coefficients relevant for radiative decays of the B meson in the SM. This is a necessary step in the calculation of the O(alpha alpha_s^n ln^n m_b/M_W) corrections and improves on our previous analysis of electroweak effects in B -> X_s gamma. We describe in detail several interesting technical aspects of the calculation and include all dominant QED matrix elements. In our final result, we neglect only terms originated from the unknown O(alpha alpha_s) evolution of the Wilson coefficients and some suppressed two-loop matrix elements. Due to the compensation among different effects, we find that non-trivial electroweak corrections decrease the branching ratio by about 3.6% for a light Higgs boson, very close to our previous result. The corresponding up-to-date SM prediction for the branching ratio with E_gamma > 1.6 GeV is (3.61 +- 0.30) x 10^-4. |
2108.03550 | Rong Wang | Rong Wang, Wei Kou, Chengdong Han, Jarah Evslin, Xurong Chen | Proton and deuteron mass radii from near-threshold $\phi$-meson
photoproduction | 6 pages, 6 figures | Phys. Rev. D 104, 074033 (2021) | 10.1103/PhysRevD.104.074033 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We analyze the exclusive $\phi$-meson photoproduction on both hydrogen and
deuterium targets based on the published data of CLAS, SAPHIR and LEPS
collaborations. A dipole-form scalar gravitational form factor is applied to
describe the $|t|$-dependence of the differential cross section. Based on the
average of all the near-threshold data from CLAS, SAPHIR and LEPS, we find that
the proton and deuteron mass radii are $0.75 \pm 0.02$ fm and $1.95 \pm 0.19$
fm respectively. The coherent and near-threshold quarkonium photoproduction
seems to be sensitive to the radius of the hadronic system. The
vector-meson-dominance model together with a low-energy QCD theorem well
describe the data of near-threshold $\phi$ photoproduction on the hadronic
systems.
| [
{
"created": "Sun, 8 Aug 2021 02:12:45 GMT",
"version": "v1"
},
{
"created": "Sat, 20 Nov 2021 15:48:54 GMT",
"version": "v2"
}
] | 2021-11-23 | [
[
"Wang",
"Rong",
""
],
[
"Kou",
"Wei",
""
],
[
"Han",
"Chengdong",
""
],
[
"Evslin",
"Jarah",
""
],
[
"Chen",
"Xurong",
""
]
] | We analyze the exclusive $\phi$-meson photoproduction on both hydrogen and deuterium targets based on the published data of CLAS, SAPHIR and LEPS collaborations. A dipole-form scalar gravitational form factor is applied to describe the $|t|$-dependence of the differential cross section. Based on the average of all the near-threshold data from CLAS, SAPHIR and LEPS, we find that the proton and deuteron mass radii are $0.75 \pm 0.02$ fm and $1.95 \pm 0.19$ fm respectively. The coherent and near-threshold quarkonium photoproduction seems to be sensitive to the radius of the hadronic system. The vector-meson-dominance model together with a low-energy QCD theorem well describe the data of near-threshold $\phi$ photoproduction on the hadronic systems. |
hep-ph/9706466 | Sheldon Stone | Sheldon Stone (Physics Dept. Syracuse University) | The Btev Program | null | null | 10.1142/9789814503952_0006 | HEPSY 97-01 | hep-ph | null | A brief description is given of BTeV a proposed program at the Fermilab
collider sited at the C0 intersection region. The main goals are measurement of
mixing, CP violation and rare decays in both the $b$ and charm systems. The
detector is a two arm forward-backward spectrometer capable of triggering on
detached vertices and dileptons, and possessing excellent particle
identification, electron, photon and muon detection.
| [
{
"created": "Mon, 23 Jun 1997 19:23:04 GMT",
"version": "v1"
}
] | 2016-11-03 | [
[
"Stone",
"Sheldon",
"",
"Physics Dept. Syracuse University"
]
] | A brief description is given of BTeV a proposed program at the Fermilab collider sited at the C0 intersection region. The main goals are measurement of mixing, CP violation and rare decays in both the $b$ and charm systems. The detector is a two arm forward-backward spectrometer capable of triggering on detached vertices and dileptons, and possessing excellent particle identification, electron, photon and muon detection. |
hep-ph/0007319 | Carl E. Wolfe | C. E. Wolfe (1), K. Maltman (2) ((1) Nuclear Theory Center, Indiana
Univ., Bloomington, USA, (2) Dept. of Math and Stats, York Univ., Toronto,
Canada and CSSM, Univ. of Adelaide, Adelaide, Australia) | The Strong Isospin-Breaking Correction for the Gluonic Penguin
Contribution to epsilon'/epsilon at Next-to-Leading Order in the Chiral
Expansion | 12 pages, 1 figure | Phys.Rev.D63:014008,2001 | 10.1103/PhysRevD.63.014008 | IU/NTC 00-04 | hep-ph | null | The strong isospin-breaking correction, Omega_{st}, which appears in
estimates of the Standard Model value for the direct CP-violating ratio
epsilon'/epsilon, is evaluated to next-to-leading order (NLO) in the chiral
expansion using Chiral Perturbation Theory. The relevant linear combinations of
the unknown NLO CP-odd weak low-energy constants (LEC's) which, in combination
with 1-loop and strong LEC contributions, are required for a complete
determination at this order, are estimated using two different models. It is
found that, to NLO, Omega_{st}=0.08 +/- 0.05, significantly reduced from the
``standard'' value, 0.25 +/- 0.08, employed in recent analyses. The potentially
significant numerical impact of this decrease on Standard Model predictions for
epsilon'/epsilon, associated with the decreased cancellation between gluonic
penguin and electroweak penguin contributions, is also discussed.
| [
{
"created": "Thu, 27 Jul 2000 18:44:57 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"Wolfe",
"C. E.",
""
],
[
"Maltman",
"K.",
""
]
] | The strong isospin-breaking correction, Omega_{st}, which appears in estimates of the Standard Model value for the direct CP-violating ratio epsilon'/epsilon, is evaluated to next-to-leading order (NLO) in the chiral expansion using Chiral Perturbation Theory. The relevant linear combinations of the unknown NLO CP-odd weak low-energy constants (LEC's) which, in combination with 1-loop and strong LEC contributions, are required for a complete determination at this order, are estimated using two different models. It is found that, to NLO, Omega_{st}=0.08 +/- 0.05, significantly reduced from the ``standard'' value, 0.25 +/- 0.08, employed in recent analyses. The potentially significant numerical impact of this decrease on Standard Model predictions for epsilon'/epsilon, associated with the decreased cancellation between gluonic penguin and electroweak penguin contributions, is also discussed. |
2208.03510 | Simone Devoto | Simone Devoto | Two-loop mixed QCD-EW corrections to neutral current Drell-Yan | Contribution to the proceedings of "Loops and Legs in Quantum Field
Theory - LL2022, 25-30 April, 2022, Ettal, Germany | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We present the mixed QCD-EW two-loop virtual amplitudes for the neutral
current Drell-Yan production, one of the bottlenecks for the complete
calculation of the NNLO mixed QCD-EW corrections. We present the computational
details and the first steps towards their automation. We describe the
evaluation of all the relevant two-loop Feynman integrals using analytical and
semi-analytical methods, the subtraction of the universal infrared
singularities and present the numerical evaluation of the finite remainder.
| [
{
"created": "Sat, 6 Aug 2022 12:45:46 GMT",
"version": "v1"
},
{
"created": "Tue, 16 Aug 2022 07:57:09 GMT",
"version": "v2"
}
] | 2022-08-17 | [
[
"Devoto",
"Simone",
""
]
] | We present the mixed QCD-EW two-loop virtual amplitudes for the neutral current Drell-Yan production, one of the bottlenecks for the complete calculation of the NNLO mixed QCD-EW corrections. We present the computational details and the first steps towards their automation. We describe the evaluation of all the relevant two-loop Feynman integrals using analytical and semi-analytical methods, the subtraction of the universal infrared singularities and present the numerical evaluation of the finite remainder. |
hep-ph/9604449 | Neville Jones | Neville R. Jones and Dongsheng Liu | Radiative decays of heavy and light mesons in a quark triangle approach | 31 pages of RevTex, 5 figures, Postscript version available at
http://info.utas.edu.au/docs/physics/theory/Publications/9548.html, scheduled
to appear in Phys. Rev. D, vol 53, issue 11, 1996 | Phys.Rev. D53 (1996) 6334-6343 | 10.1103/PhysRevD.53.6334 | UTAS-PHYS-95-48 | hep-ph | null | The radiative meson decays $V\to P\gamma$ and $P\to \gamma\gamma$ are
analyzed using the quark triangle diagram. Experimental data yield well
determined estimates of the universal quark-antiquark-meson couplings
$g_{Vq\bar{q}'}$ and $g_{Pq\bar{q}'}$ for the light meson sector. Also
predictions for the ratios of neutral to charged heavy meson decay coupling
constants are given and await experimental confirmation.
| [
{
"created": "Tue, 30 Apr 1996 23:27:05 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Jones",
"Neville R.",
""
],
[
"Liu",
"Dongsheng",
""
]
] | The radiative meson decays $V\to P\gamma$ and $P\to \gamma\gamma$ are analyzed using the quark triangle diagram. Experimental data yield well determined estimates of the universal quark-antiquark-meson couplings $g_{Vq\bar{q}'}$ and $g_{Pq\bar{q}'}$ for the light meson sector. Also predictions for the ratios of neutral to charged heavy meson decay coupling constants are given and await experimental confirmation. |
1808.02501 | Adrian Dumitru | Adrian Dumitru, Gerald A. Miller, Raju Venugopalan | Extracting many-body color charge correlators in the proton from
exclusive DIS at large Bjorken x | 22 pages, 4 figures; v2: corrected LaTeX coding error; v3: corrected
a few typos, added some remarks on Odderon contribution to J/Psi production
and a few references, to appear in PRD | Phys. Rev. D 98, 094004 (2018) | 10.1103/PhysRevD.98.094004 | NT@UW-18-08 | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We construct a general QCD light front formalism to compute many-body color
charge correlators in the proton. These form factors can be extracted from
deeply inelastic scattering measurements of exclusive final states in analogy
to electromagnetic form factors extracted in elastic electron scattering
experiments. Particularly noteworthy is the potential to extract a novel
Odderon form factor, either indirectly from exclusive $J/\Psi$ measurements, or
directly from exclusive measurements of the $\eta_c$ or tensor mesons at large
Bjorken x. Besides the intrinsic information conveyed by these color charge
correlators on the spatio-temporal tomography at the sub-femtoscopic scale at
large x, the corresponding cumulants extend the domain of validity of
McLerran-Venugopalan type weight functionals from small x and large nuclei to
nucleons and light nuclei at large $x$, as well as to non-zero momentum
transfer. This may significantly reduce nonperturbative systematic
uncertainties in the initial conditions for QCD evolution equations at small
$x$ and could be of strong relevance for the phenomenology of present and
future collider experiments.
| [
{
"created": "Tue, 7 Aug 2018 18:06:09 GMT",
"version": "v1"
},
{
"created": "Thu, 23 Aug 2018 16:46:38 GMT",
"version": "v2"
},
{
"created": "Mon, 15 Oct 2018 13:49:57 GMT",
"version": "v3"
}
] | 2018-11-12 | [
[
"Dumitru",
"Adrian",
""
],
[
"Miller",
"Gerald A.",
""
],
[
"Venugopalan",
"Raju",
""
]
] | We construct a general QCD light front formalism to compute many-body color charge correlators in the proton. These form factors can be extracted from deeply inelastic scattering measurements of exclusive final states in analogy to electromagnetic form factors extracted in elastic electron scattering experiments. Particularly noteworthy is the potential to extract a novel Odderon form factor, either indirectly from exclusive $J/\Psi$ measurements, or directly from exclusive measurements of the $\eta_c$ or tensor mesons at large Bjorken x. Besides the intrinsic information conveyed by these color charge correlators on the spatio-temporal tomography at the sub-femtoscopic scale at large x, the corresponding cumulants extend the domain of validity of McLerran-Venugopalan type weight functionals from small x and large nuclei to nucleons and light nuclei at large $x$, as well as to non-zero momentum transfer. This may significantly reduce nonperturbative systematic uncertainties in the initial conditions for QCD evolution equations at small $x$ and could be of strong relevance for the phenomenology of present and future collider experiments. |
hep-ph/0503298 | Shang-Yung Wang | C. N. Leung, S.-Y. Wang | Gauge Independence and Chiral Symmetry Breaking in a Strong Magnetic
Field | 10 pages, 1 eps figure, version to appear in Annals of Physics | AnnalsPhys.322:701-708,2007 | 10.1016/j.aop.2006.03.006 | null | hep-ph astro-ph cond-mat.mes-hall hep-th nucl-th | null | The gauge independence of the dynamical fermion mass generated through chiral
symmetry breaking in QED in a strong, constant external magnetic field is
critically examined. We present a (first, to the best of our knowledge)
consistent truncation of the Schwinger-Dyson equations in the lowest Landau
level approximation. We demonstrate that the dynamical fermion mass, obtained
as the solution of the truncated Schwinger-Dyson equations evaluated on the
fermion mass shell, is manifestly gauge independent.
| [
{
"created": "Thu, 31 Mar 2005 16:54:31 GMT",
"version": "v1"
},
{
"created": "Wed, 6 Apr 2005 18:34:07 GMT",
"version": "v2"
},
{
"created": "Fri, 17 Mar 2006 00:35:16 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Leung",
"C. N.",
""
],
[
"Wang",
"S. -Y.",
""
]
] | The gauge independence of the dynamical fermion mass generated through chiral symmetry breaking in QED in a strong, constant external magnetic field is critically examined. We present a (first, to the best of our knowledge) consistent truncation of the Schwinger-Dyson equations in the lowest Landau level approximation. We demonstrate that the dynamical fermion mass, obtained as the solution of the truncated Schwinger-Dyson equations evaluated on the fermion mass shell, is manifestly gauge independent. |
hep-ph/9307214 | null | R. G. Leigh | The Strong CP Problem, String Theory and the Nelson-Barr Mechanism | preprint SCIPP 93/14; 10 pages, latex format, uses epsf.tex for 2
figures, submitted separately via `uufiles' | null | null | null | hep-ph | null | We review recent work on the strong CP problem in the context of realistic
string-inspired models. We discuss the various solutions, review the conjecture
that CP is generally a gauged discrete symmetry in string theory and then
consider models of the Nelson-Barr type. We note that squark non-degeneracy
spoils the Nelson-Barr structure at the one loop level. We stress that string
theory expectations, as well as naturalness arguments, make it very difficult
to avoid the constraints on non-degeneracy.
| [
{
"created": "Fri, 2 Jul 1993 21:15:00 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Leigh",
"R. G.",
""
]
] | We review recent work on the strong CP problem in the context of realistic string-inspired models. We discuss the various solutions, review the conjecture that CP is generally a gauged discrete symmetry in string theory and then consider models of the Nelson-Barr type. We note that squark non-degeneracy spoils the Nelson-Barr structure at the one loop level. We stress that string theory expectations, as well as naturalness arguments, make it very difficult to avoid the constraints on non-degeneracy. |
hep-ph/0006340 | Ernest Ma | Ernest Ma (UC Riverside), G. Rajasekaran (IMSC, Madras), Utpal Sarkar
(PRL, Ahmedabad) | Light Sterile Neutrinos from Large Extra Dimensions | 10 pages, no figure, remarks and references added | Phys.Lett. B495 (2000) 363-368 | 10.1016/S0370-2693(00)01252-1 | UCRHEP-T281 | hep-ph | null | An experimentally verifiable Higgs-triplet model of neutrino masses from
large extra dimensions was recently proposed. We extend it to accomodate a
light sterile neutrino which also mixes with the three active neutrinos. A
previously proposed phenomenological model of four neutrinos (\underline {the
only viable such model now left}, in view of the latest atmospheric and solar
neutrino-oscillation data) is specifically realized.
| [
{
"created": "Thu, 29 Jun 2000 17:32:42 GMT",
"version": "v1"
},
{
"created": "Wed, 19 Jul 2000 15:51:48 GMT",
"version": "v2"
}
] | 2009-10-31 | [
[
"Ma",
"Ernest",
"",
"UC Riverside"
],
[
"Rajasekaran",
"G.",
"",
"IMSC, Madras"
],
[
"Sarkar",
"Utpal",
"",
"PRL, Ahmedabad"
]
] | An experimentally verifiable Higgs-triplet model of neutrino masses from large extra dimensions was recently proposed. We extend it to accomodate a light sterile neutrino which also mixes with the three active neutrinos. A previously proposed phenomenological model of four neutrinos (\underline {the only viable such model now left}, in view of the latest atmospheric and solar neutrino-oscillation data) is specifically realized. |
2308.11248 | Hidetoshi Taya | Hidetoshi Taya, Charlie Ironside | Kramers-Kr\"onig approach to the electric permittivity of the vacuum in
a strong constant electric field | 27 pages, 6 figures; v2: references added, discussions improved, to
appear in Phys. Rev. D | null | null | RIKEN-iTHEMS-Report-23 | hep-ph hep-th physics.optics | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the electric permittivity of the QED vacuum in the presence of a
strong constant electric field, motivated by the analogy between the
dynamically-assisted Schwinger effect in strong-field QED and the Franz-Keldysh
effect in semiconductor physics. We develop a linear-response theory based on
the non-equilibrium in-in formalism and the Furry-picture perturbation theory,
with which and also utilizing the Kramers-Kr\"onig relation, we calculate the
electric permittivity without assuming weak fields and low-frequency probes. We
discover that the electric permittivity exhibits characteristic oscillating
dependence on the probe frequency, which directly reflects the change of the
QED-vacuum structure by the strong field. We also establish a quantitative
correspondence between the electric permittivity and the number of
electron-positron pairs produced by the dynamically-assisted Schwinger effect.
| [
{
"created": "Tue, 22 Aug 2023 07:44:43 GMT",
"version": "v1"
},
{
"created": "Fri, 27 Oct 2023 15:01:25 GMT",
"version": "v2"
}
] | 2023-10-30 | [
[
"Taya",
"Hidetoshi",
""
],
[
"Ironside",
"Charlie",
""
]
] | We study the electric permittivity of the QED vacuum in the presence of a strong constant electric field, motivated by the analogy between the dynamically-assisted Schwinger effect in strong-field QED and the Franz-Keldysh effect in semiconductor physics. We develop a linear-response theory based on the non-equilibrium in-in formalism and the Furry-picture perturbation theory, with which and also utilizing the Kramers-Kr\"onig relation, we calculate the electric permittivity without assuming weak fields and low-frequency probes. We discover that the electric permittivity exhibits characteristic oscillating dependence on the probe frequency, which directly reflects the change of the QED-vacuum structure by the strong field. We also establish a quantitative correspondence between the electric permittivity and the number of electron-positron pairs produced by the dynamically-assisted Schwinger effect. |
1608.07903 | Hong-Shi Zong | Wenkai Fan, Xiaofeng Luo and Hong-Shi Zong | Susceptibilities of Conserved Charges within a Modified
Nambu-Jona-Lasinio Model | 8 pages, 10 figures, 45 references | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We evaluate the $2$nd to $4$th order baryon, charge and strangeness
susceptibilities near a chiral critical point using the Nambu--Jona--Lasinio
model under different temperature and baryon chemical potential. Baryon number
susceptibilities are found to be of the greatest magnitude, offering the
strongest signal. Whereas the strangeness susceptibilities have the smallest
divergence dominating area, owing to the large strange quark mass. We also make
an attempt to compare our results with experiment data. The trend at high
collision energy are found to be consistent between theory and experiment. The
model calculation predicts more complex behavior at low collision energies,
near the postulated critical end point.
| [
{
"created": "Mon, 29 Aug 2016 03:32:31 GMT",
"version": "v1"
},
{
"created": "Tue, 6 Sep 2016 08:56:22 GMT",
"version": "v2"
},
{
"created": "Sun, 25 Sep 2016 06:33:44 GMT",
"version": "v3"
},
{
"created": "Tue, 20 Dec 2016 09:51:20 GMT",
"version": "v4"
}
] | 2016-12-21 | [
[
"Fan",
"Wenkai",
""
],
[
"Luo",
"Xiaofeng",
""
],
[
"Zong",
"Hong-Shi",
""
]
] | We evaluate the $2$nd to $4$th order baryon, charge and strangeness susceptibilities near a chiral critical point using the Nambu--Jona--Lasinio model under different temperature and baryon chemical potential. Baryon number susceptibilities are found to be of the greatest magnitude, offering the strongest signal. Whereas the strangeness susceptibilities have the smallest divergence dominating area, owing to the large strange quark mass. We also make an attempt to compare our results with experiment data. The trend at high collision energy are found to be consistent between theory and experiment. The model calculation predicts more complex behavior at low collision energies, near the postulated critical end point. |
2405.06040 | Arpita Mondal | Arghya Choudhury, Arpita Mondal, Subhadeep Sarkar | Searches for the BSM scenarios at the LHC using decision tree based
machine learning algorithms: A comparative study and review of Random Forest,
Adaboost, XGboost and LightGBM frameworks | 62 pages, 26 figures, 9 tables | null | null | null | hep-ph hep-ex physics.comp-ph | http://creativecommons.org/licenses/by/4.0/ | Machine learning algorithms are now being extensively used in our daily
lives, spanning across diverse industries as well as academia. In the field of
high energy physics (HEP), the most common and challenging task is separating a
rare signal from a much larger background. The boosted decision tree (BDT)
algorithm has been a cornerstone of the high energy physics for analyzing event
triggering, particle identification, jet tagging, object reconstruction, event
classification, and other related tasks for quite some time. This article
presents a comprehensive overview of research conducted by both HEP
experimental and phenomenological groups that utilize decision tree algorithms
in the context of the Standard Model and Supersymmetry (SUSY). We also
summarize the basic concept of machine learning and decision tree algorithm
along with the working principle of \texttt{Random Forest}, \texttt{AdaBoost}
and two gradient boosting frameworks, such as \texttt{XGBoost}, and
\texttt{LightGBM}. Using a case study of electroweakino productions at the high
luminosity LHC, we demonstrate how these algorithms lead to improvement in the
search sensitivity compared to traditional cut-based methods in both compressed
and non-compressed R-parity conserving SUSY scenarios. The effect of different
hyperparameters and their optimization, feature importance study using SHapley
values are also discussed in detail.
| [
{
"created": "Thu, 9 May 2024 18:19:36 GMT",
"version": "v1"
}
] | 2024-05-14 | [
[
"Choudhury",
"Arghya",
""
],
[
"Mondal",
"Arpita",
""
],
[
"Sarkar",
"Subhadeep",
""
]
] | Machine learning algorithms are now being extensively used in our daily lives, spanning across diverse industries as well as academia. In the field of high energy physics (HEP), the most common and challenging task is separating a rare signal from a much larger background. The boosted decision tree (BDT) algorithm has been a cornerstone of the high energy physics for analyzing event triggering, particle identification, jet tagging, object reconstruction, event classification, and other related tasks for quite some time. This article presents a comprehensive overview of research conducted by both HEP experimental and phenomenological groups that utilize decision tree algorithms in the context of the Standard Model and Supersymmetry (SUSY). We also summarize the basic concept of machine learning and decision tree algorithm along with the working principle of \texttt{Random Forest}, \texttt{AdaBoost} and two gradient boosting frameworks, such as \texttt{XGBoost}, and \texttt{LightGBM}. Using a case study of electroweakino productions at the high luminosity LHC, we demonstrate how these algorithms lead to improvement in the search sensitivity compared to traditional cut-based methods in both compressed and non-compressed R-parity conserving SUSY scenarios. The effect of different hyperparameters and their optimization, feature importance study using SHapley values are also discussed in detail. |
hep-ph/9401357 | null | Brian H. Smith and M.B. Voloshin | On normalization of QCD effects in $O(m_t^2)$ electroweak corrections | LaTeX, 10 pages + 1 figure (appended as a PostScript file) | Phys.Rev. D51 (1995) 5251-5255 | 10.1103/PhysRevD.51.5251 | TPI-MINN-94/5-T, UMN-TH-1241/94 | hep-ph | null | We point out that, contrary to some recent claims, there is no intrinsic
long-distance uncertainty in perturbative calculation of the QCD effects in the
$t \tb$ and $t \bb$ loops giving the electroweak corrections proportional to
$m_t^2$. If these corrections are expressed in terms of the ``on-shell" mass
$m_t$, the only ambiguity arising is that associated with the definition of the
``on-shell" mass of a quark. The latter is entirely eliminated if the result is
expressed in terms of $m_t$ defined at short distances. Applying the
Brodsky-Lepage-Mackenzie criterion for determining the natural scale for
normalization of $\as$, we find that using the ``on-shell" mass makes this
scale numerically small in units of $m_t$. Specifically, we find that by this
criterion the first QCD correction to the $O(m_t^2)$ terms is determined by
$\as^\msb(0.15 m_t)$. Naturally, a full calculation of three-loop graphs is
needed to completely quantify the scale.
| [
{
"created": "Mon, 31 Jan 1994 23:30:57 GMT",
"version": "v1"
},
{
"created": "Thu, 3 Feb 1994 20:18:56 GMT",
"version": "v2"
}
] | 2009-10-28 | [
[
"Smith",
"Brian H.",
""
],
[
"Voloshin",
"M. B.",
""
]
] | We point out that, contrary to some recent claims, there is no intrinsic long-distance uncertainty in perturbative calculation of the QCD effects in the $t \tb$ and $t \bb$ loops giving the electroweak corrections proportional to $m_t^2$. If these corrections are expressed in terms of the ``on-shell" mass $m_t$, the only ambiguity arising is that associated with the definition of the ``on-shell" mass of a quark. The latter is entirely eliminated if the result is expressed in terms of $m_t$ defined at short distances. Applying the Brodsky-Lepage-Mackenzie criterion for determining the natural scale for normalization of $\as$, we find that using the ``on-shell" mass makes this scale numerically small in units of $m_t$. Specifically, we find that by this criterion the first QCD correction to the $O(m_t^2)$ terms is determined by $\as^\msb(0.15 m_t)$. Naturally, a full calculation of three-loop graphs is needed to completely quantify the scale. |
1704.00881 | Arindam Das | Arindam Das, Yu Gao, Teruki Kamon | Heavy Neutrino Search via the Higgs boson at the LHC | 22 pages, 7 Figures, updated analysis, model part extended, matched
journal version in EPJC | Eur.Phys.J. C79 (2019) no.5, 424 | 10.1140/epjc/s10052-019-6937-7 | WSU-HEP-1706, MI-TH-1748 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the inverse see-saw model the effective neutrino Yukawa couplings can be
sizable due to a large mixing angle between the light $(\nu)$and heavy
neutrinos $(N)$. When the right handed neutrino $(N)$ can be lighter than the
Standard Model (SM) Higgs boson $(h)$. It can be produced via the on-shell
decay of the Higgs, $h\to N\nu$ at a significant branching fraction at the LHC.
In such a process $N$ mass can be reconstructed in its dominant $N\rightarrow W
\ell$ decays. We perform an analysis on this channel and its relevant
backgrounds, among which the $W+$jets background is the largest. Considering
the existing mixing constraints from the Higgs and electroweak precision data,
the best sensitivity of the heavy neutrino search is achieved for benchmark $N$
mass at 100 and 110 GeV for upcoming high luminosity LHC runs.
| [
{
"created": "Tue, 4 Apr 2017 06:00:57 GMT",
"version": "v1"
},
{
"created": "Mon, 27 May 2019 19:30:06 GMT",
"version": "v2"
}
] | 2019-05-29 | [
[
"Das",
"Arindam",
""
],
[
"Gao",
"Yu",
""
],
[
"Kamon",
"Teruki",
""
]
] | In the inverse see-saw model the effective neutrino Yukawa couplings can be sizable due to a large mixing angle between the light $(\nu)$and heavy neutrinos $(N)$. When the right handed neutrino $(N)$ can be lighter than the Standard Model (SM) Higgs boson $(h)$. It can be produced via the on-shell decay of the Higgs, $h\to N\nu$ at a significant branching fraction at the LHC. In such a process $N$ mass can be reconstructed in its dominant $N\rightarrow W \ell$ decays. We perform an analysis on this channel and its relevant backgrounds, among which the $W+$jets background is the largest. Considering the existing mixing constraints from the Higgs and electroweak precision data, the best sensitivity of the heavy neutrino search is achieved for benchmark $N$ mass at 100 and 110 GeV for upcoming high luminosity LHC runs. |
2402.18497 | Alan Hern\'andez | A. I. Hern\'andez-Ju\'arez, R. Gait\'an, G. Tavares-Velasco | Polarized and unpolarized off-shell $H^\ast\to ZZ\rightarrow 4\ell$
decay above the $2m_Z$ threshold | To be published in Chinese Physics C | null | 10.1088/1674-1137/ad62de | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | An analysis of the off-shell $H^\ast\rightarrow ZZ \rightarrow
\overline{\ell}_1\ell_1\overline{\ell}_2\ell_2$ decay width is presented for
both unpolarized and polarized $Z$ gauge bosons in the scenario with the most
general $H^*ZZ$ vertex function, which is given in terms of two $CP$-even
($\hat b_Z$ and $\hat c_Z$) and one $CP$-odd ($\tilde b_Z$) anomalous
couplings.
The SM contributions to the $H^*ZZ$ coupling up to the one-loop level are
also included. Explicit analytic results for the unpolarized and polarized
$H^\ast\rightarrow ZZ \rightarrow
\overline{\ell}_1\ell_1\overline{\ell}_2\ell_2$ square amplitudes and the
four-body phase space are presented, out of which several observable quantities
can be obtained straightforwardly. As far as the numerical analysis is
concerned, a cross-check is performed via \texttt{MadGraph5\_aMC@NLO}, where
our model was implemented with the aid of FeynRules. We then consider the most
stringent bounds on anomalous complex $H^*ZZ$ couplings and analyze the effects
of the polarizations of the $Z$ gauge bosons through the polarized
$H^\ast\rightarrow ZZ \rightarrow
\overline{\ell}_1\ell_1\overline{\ell}_2\ell_2$ decay width as well as
left-right and forward-backward asymmetries, which are found to be sensitive to
new-physics effects. Particular focus is put on the effects of the absorptive
parts of the anomalous $H^*ZZ$ couplings, which have been largely overlooked up
to now in LHC analyses. It is found that the studied observable quantities,
particularly the left-right asymmetries, can be helpful to look for effects of
$CP$-violation in the $H^*ZZ$ coupling and set bounds on the absorptive parts.
For completeness, we also analyze the case of unpolarized $Z$ gauge bosons.
| [
{
"created": "Wed, 28 Feb 2024 17:26:36 GMT",
"version": "v1"
},
{
"created": "Mon, 8 Jul 2024 17:49:57 GMT",
"version": "v2"
}
] | 2024-07-23 | [
[
"Hernández-Juárez",
"A. I.",
""
],
[
"Gaitán",
"R.",
""
],
[
"Tavares-Velasco",
"G.",
""
]
] | An analysis of the off-shell $H^\ast\rightarrow ZZ \rightarrow \overline{\ell}_1\ell_1\overline{\ell}_2\ell_2$ decay width is presented for both unpolarized and polarized $Z$ gauge bosons in the scenario with the most general $H^*ZZ$ vertex function, which is given in terms of two $CP$-even ($\hat b_Z$ and $\hat c_Z$) and one $CP$-odd ($\tilde b_Z$) anomalous couplings. The SM contributions to the $H^*ZZ$ coupling up to the one-loop level are also included. Explicit analytic results for the unpolarized and polarized $H^\ast\rightarrow ZZ \rightarrow \overline{\ell}_1\ell_1\overline{\ell}_2\ell_2$ square amplitudes and the four-body phase space are presented, out of which several observable quantities can be obtained straightforwardly. As far as the numerical analysis is concerned, a cross-check is performed via \texttt{MadGraph5\_aMC@NLO}, where our model was implemented with the aid of FeynRules. We then consider the most stringent bounds on anomalous complex $H^*ZZ$ couplings and analyze the effects of the polarizations of the $Z$ gauge bosons through the polarized $H^\ast\rightarrow ZZ \rightarrow \overline{\ell}_1\ell_1\overline{\ell}_2\ell_2$ decay width as well as left-right and forward-backward asymmetries, which are found to be sensitive to new-physics effects. Particular focus is put on the effects of the absorptive parts of the anomalous $H^*ZZ$ couplings, which have been largely overlooked up to now in LHC analyses. It is found that the studied observable quantities, particularly the left-right asymmetries, can be helpful to look for effects of $CP$-violation in the $H^*ZZ$ coupling and set bounds on the absorptive parts. For completeness, we also analyze the case of unpolarized $Z$ gauge bosons. |
2108.10106 | Manas Mohapatra | Manas K. Mohapatra, N Rajeev, Rupak Dutta | Combined analysis of $B_c \to D_s^{(*)}\,\mu ^+ \mu ^-$ and $B_c \to
D_s^{(*)}\, \nu \bar{\nu}$ decays within $Z^{\prime}$ and leptoquark new
physics models | Matches with the published version | null | 10.1103/PhysRevD.105.115022 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We investigate the exclusive rare semileptonic decays $ B_c \to
D_{s}^{(*)}\,(\ell \ell, \nu \bar{\nu})$ induced by neutral current transition
$b \to s (\ell \ell,\nu \bar{\nu})$ in the presence of non-universal
$Z^{\prime}$, scalar and vector leptoquark new physics models. We constrain the
new physics parameter space by using the latest experimental measurements of
$R_{K^{(*)}}$, $P_5^{\prime}$, $\mathcal{B}(B_s \to \phi \mu^+ \mu^-)$ and
$\mathcal{B}(B_s \to \mu^+ \mu^-)$. Throughout the analysis, we choose to work
with the particular new physics scenario $C_9 ^{\mu \mu}(NP)=-C_{10} ^{\mu
\mu}(NP)$ where both $Z^{\prime}$, $S_{1/3}^3$ and $U_{-2/3}^3$ leptoquarks
satisfy the condition. Using these new coupling parameters we scrutinize the
several physical observables such as differential branching fraction, the
forward backward asymmetry, the lepton polarization asymmetry, the angular
observable $P^{\prime}_5$ and the lepton flavor universal sensitive observables
including the ratio of branching ratio $R_{D_s^{(*)}}$ and the few $Q$
parameters in the $B_c \to D_s^{(*)}\,\mu ^+ \mu ^-$ and $B_c \to D_s^{(*)}\,
\nu \bar{\nu}$ decay processes.
| [
{
"created": "Mon, 23 Aug 2021 12:21:29 GMT",
"version": "v1"
},
{
"created": "Sun, 23 Jul 2023 11:22:49 GMT",
"version": "v2"
}
] | 2023-07-25 | [
[
"Mohapatra",
"Manas K.",
""
],
[
"Rajeev",
"N",
""
],
[
"Dutta",
"Rupak",
""
]
] | We investigate the exclusive rare semileptonic decays $ B_c \to D_{s}^{(*)}\,(\ell \ell, \nu \bar{\nu})$ induced by neutral current transition $b \to s (\ell \ell,\nu \bar{\nu})$ in the presence of non-universal $Z^{\prime}$, scalar and vector leptoquark new physics models. We constrain the new physics parameter space by using the latest experimental measurements of $R_{K^{(*)}}$, $P_5^{\prime}$, $\mathcal{B}(B_s \to \phi \mu^+ \mu^-)$ and $\mathcal{B}(B_s \to \mu^+ \mu^-)$. Throughout the analysis, we choose to work with the particular new physics scenario $C_9 ^{\mu \mu}(NP)=-C_{10} ^{\mu \mu}(NP)$ where both $Z^{\prime}$, $S_{1/3}^3$ and $U_{-2/3}^3$ leptoquarks satisfy the condition. Using these new coupling parameters we scrutinize the several physical observables such as differential branching fraction, the forward backward asymmetry, the lepton polarization asymmetry, the angular observable $P^{\prime}_5$ and the lepton flavor universal sensitive observables including the ratio of branching ratio $R_{D_s^{(*)}}$ and the few $Q$ parameters in the $B_c \to D_s^{(*)}\,\mu ^+ \mu ^-$ and $B_c \to D_s^{(*)}\, \nu \bar{\nu}$ decay processes. |
hep-ph/0304087 | Leonid Glozman | L.Ya. Glozman | Chiral and U(1)_A restorations high in the hadron spectrum and the
semiclassical approximation | 4 pages, LaTeX | null | null | null | hep-ph nucl-th | null | In quantum systems with large $n$ (radial quantum number) or large angular
momentum the semiclassical (WKB) approximation is valid. A physical content of
the semiclassical approximation is that the quantum fluctuations effects are
suppressed and vanish asymptotically. The chiral as well as $U(1)_A$ breakings
in QCD is a result of quantum fluctuations. Hence these breakings must be
absent (suppressed) high in the spectrum and the spectrum of high-lying hadrons
must exhibit symmetries of the classical QCD Lagrangian.
| [
{
"created": "Wed, 9 Apr 2003 09:34:54 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Glozman",
"L. Ya.",
""
]
] | In quantum systems with large $n$ (radial quantum number) or large angular momentum the semiclassical (WKB) approximation is valid. A physical content of the semiclassical approximation is that the quantum fluctuations effects are suppressed and vanish asymptotically. The chiral as well as $U(1)_A$ breakings in QCD is a result of quantum fluctuations. Hence these breakings must be absent (suppressed) high in the spectrum and the spectrum of high-lying hadrons must exhibit symmetries of the classical QCD Lagrangian. |
hep-ph/9610415 | Gert Aarts | Gert Aarts (Utrecht University), Jan Smit (Utrecht University,
University of Amsterdam) | Finiteness of Hot Classical Scalar Field Theory and the Plasmon Damping
Rate | 11 pages, 4 eps figures, minor typographic corrections and two
references added | Phys.Lett. B393 (1997) 395-402 | 10.1016/S0370-2693(96)01624-3 | THU-96-37, ITFA-96-43 | hep-ph hep-th | null | We investigate the renormalizability of the classical $\phi^4$ theory at
finite temperature. We calculate the time-dependent two point function to two
loop order and show that it can be rendered finite by the counterterms of the
classical static theory. As an application the classical plasmon damping rate
is found to be $\gamma = \lambda^2 T^2/1536 \pi m$. When we use the high
temperature expression for $m$ given by dimensional reduction, the rate is
found to agree with the quantum mechanical result.
| [
{
"created": "Fri, 18 Oct 1996 15:09:38 GMT",
"version": "v1"
},
{
"created": "Wed, 11 Dec 1996 14:11:28 GMT",
"version": "v2"
}
] | 2009-10-30 | [
[
"Aarts",
"Gert",
"",
"Utrecht University"
],
[
"Smit",
"Jan",
"",
"Utrecht University,\n University of Amsterdam"
]
] | We investigate the renormalizability of the classical $\phi^4$ theory at finite temperature. We calculate the time-dependent two point function to two loop order and show that it can be rendered finite by the counterterms of the classical static theory. As an application the classical plasmon damping rate is found to be $\gamma = \lambda^2 T^2/1536 \pi m$. When we use the high temperature expression for $m$ given by dimensional reduction, the rate is found to agree with the quantum mechanical result. |
hep-ph/9907252 | Vicente Pleitez | V. Pleitez | Direct CP violation in semi-leptonic and leptonic decays | 7 pages, Revtex, 3 eps figures | null | null | IFT-P.055/99 | hep-ph | null | We show that direct CP violation in semi-leptonic and leptonic decays can
occur in multi-Higgs doublet extensions of the electroweak standard model with
flavor changing neutral currents. For pion and lepton decays these $CP$
violating effects cannot be constrained directly by experimental data since up
to now the branching ratio of the decays $\pi^-$ and $\mu^-$ have not been
measured in laboratory.
| [
{
"created": "Tue, 6 Jul 1999 13:13:13 GMT",
"version": "v1"
},
{
"created": "Thu, 14 Dec 2000 20:37:49 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Pleitez",
"V.",
""
]
] | We show that direct CP violation in semi-leptonic and leptonic decays can occur in multi-Higgs doublet extensions of the electroweak standard model with flavor changing neutral currents. For pion and lepton decays these $CP$ violating effects cannot be constrained directly by experimental data since up to now the branching ratio of the decays $\pi^-$ and $\mu^-$ have not been measured in laboratory. |
2104.12689 | Bin Yan | Ke-Pan Xie and Bin Yan | Probing the electroweak symmetry breaking with Higgs production at the
LHC | 5 pages, 7 figures, published version | null | 10.1016/j.physletb.2021.136515 | LA-UR-21-24074 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The electroweak symmetry breaking (EWSB) mechanism is still an undecided
question in particle physics. We propose to utilize the single top quark and
Higgs associated production ($th$), $Zh$ production via gluon fusion at the LHC
to probe the couplings between the Higgs and the gauge bosons and further to
test the EWSB. We demonstrate that the $th$ and $gg\to Zh$ productions are
sensitive to the relative sign of couplings ($ht\bar{t}$, $hWW$) and
($ht\bar{t}$, $hZZ$), respectively. We find that the relative sign between
$hWW$ and $hZZ$ couplings could be fully determined after combining the present
measurements from $gg\to h$, $t\bar{t}h$ and the $th$, $Zh$ channels, as well
as $tZj$ and $Zt\bar{t}$ production at the 13 TeV LHC, and this conclusion is
not sensitive to the possible new physics contribution induced by $Zt\bar{t}$
couplings in the $gg\to Zh$ production.
| [
{
"created": "Mon, 26 Apr 2021 16:28:14 GMT",
"version": "v1"
},
{
"created": "Thu, 15 Jul 2021 23:28:01 GMT",
"version": "v2"
}
] | 2021-07-19 | [
[
"Xie",
"Ke-Pan",
""
],
[
"Yan",
"Bin",
""
]
] | The electroweak symmetry breaking (EWSB) mechanism is still an undecided question in particle physics. We propose to utilize the single top quark and Higgs associated production ($th$), $Zh$ production via gluon fusion at the LHC to probe the couplings between the Higgs and the gauge bosons and further to test the EWSB. We demonstrate that the $th$ and $gg\to Zh$ productions are sensitive to the relative sign of couplings ($ht\bar{t}$, $hWW$) and ($ht\bar{t}$, $hZZ$), respectively. We find that the relative sign between $hWW$ and $hZZ$ couplings could be fully determined after combining the present measurements from $gg\to h$, $t\bar{t}h$ and the $th$, $Zh$ channels, as well as $tZj$ and $Zt\bar{t}$ production at the 13 TeV LHC, and this conclusion is not sensitive to the possible new physics contribution induced by $Zt\bar{t}$ couplings in the $gg\to Zh$ production. |
2007.03662 | Joe Davighi | Joe Davighi, Matthew McCullough, Joseph Tooby-Smith | Undulating Dark Matter | 10 pages, 3 figures | null | 10.1007/JHEP11(2020)120 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We suggest that an interplay between microscopic and macroscopic physics can
give rise to dark matter (DM) whose interactions with the visible sector
fundamentally undulate in time, independent of celestial dynamics. A concrete
example is provided by fermionic DM with an electric dipole moment (EDM)
sourced by an oscillating axion-like field, resulting in undulations in the
scattering rate. The discovery potential of light DM searches can be enhanced
by additionally searching for undulating scattering rates, especially in
detection regions where background rates are large and difficult to estimate,
such as for DM masses in the vicinity of 1 MeV where DM-electron scattering
dominantly populates the single electron bin. An undulating signal could also
reveal precious dark sector information after discovery. In this regard we
emphasise that, if the recent XENON1T excess of events is due to light DM
scattering exothermically off electrons, future analyses of the time-dependence
of events could offer clues as to the microscopic origins of the putative
signal.
| [
{
"created": "Tue, 7 Jul 2020 17:50:53 GMT",
"version": "v1"
}
] | 2020-12-30 | [
[
"Davighi",
"Joe",
""
],
[
"McCullough",
"Matthew",
""
],
[
"Tooby-Smith",
"Joseph",
""
]
] | We suggest that an interplay between microscopic and macroscopic physics can give rise to dark matter (DM) whose interactions with the visible sector fundamentally undulate in time, independent of celestial dynamics. A concrete example is provided by fermionic DM with an electric dipole moment (EDM) sourced by an oscillating axion-like field, resulting in undulations in the scattering rate. The discovery potential of light DM searches can be enhanced by additionally searching for undulating scattering rates, especially in detection regions where background rates are large and difficult to estimate, such as for DM masses in the vicinity of 1 MeV where DM-electron scattering dominantly populates the single electron bin. An undulating signal could also reveal precious dark sector information after discovery. In this regard we emphasise that, if the recent XENON1T excess of events is due to light DM scattering exothermically off electrons, future analyses of the time-dependence of events could offer clues as to the microscopic origins of the putative signal. |
1210.2331 | Christian Schubert | Naser Ahmadiniaz, Christian Schubert | A covariant representation of the Ball-Chiu vertex | 32 pages, 1 figure, final revised version (calculation of the
two-point functions included, minor corrections, references added) | Nuclear Physics B 869 (2013) 417-439 | 10.1016/j.nuclphysb.2012.12.019 | Preprint AEI-2012-104 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In nonabelian gauge theory the three-gluon vertex function contains important
structural information, in particular on infrared divergences, and is also an
essential ingredient in the Schwinger-Dyson equations. Much effort has gone
into analyzing its general structure, and at the one-loop level also a number
of explicit computations have been done, using various approaches. Here we use
the string-inspired formalism to unify the calculations of the scalar, spinor
and gluon loop contributions to the one-loop vertex, leading to an extremely
compact representation in all cases. The vertex is computed fully off-shell and
in dimensionally continued form, so that it can be used as a building block for
higher-loop calculations. We find that the Bern-Kosower loop replacement rules,
originally derived for the on-shell case, hold off-shell as well. We explain
the relation of the structure of this representation to the low-energy
effective action, and establish the precise connection with the standard
Ball-Chiu decomposition of the vertex. This allows us also to predict that the
vanishing of the completely antisymmetric coefficient function S of this
decomposition is not a one-loop accident, but persists at higher loop orders.
The sum rule found by Binger and Brodsky, which leads to the vanishing of the
one-loop vertex in N=4 SYM theory, in the present approach relates to worldline
supersymmetry.
| [
{
"created": "Mon, 8 Oct 2012 16:28:54 GMT",
"version": "v1"
},
{
"created": "Sat, 26 Jan 2013 15:00:51 GMT",
"version": "v2"
}
] | 2015-06-11 | [
[
"Ahmadiniaz",
"Naser",
""
],
[
"Schubert",
"Christian",
""
]
] | In nonabelian gauge theory the three-gluon vertex function contains important structural information, in particular on infrared divergences, and is also an essential ingredient in the Schwinger-Dyson equations. Much effort has gone into analyzing its general structure, and at the one-loop level also a number of explicit computations have been done, using various approaches. Here we use the string-inspired formalism to unify the calculations of the scalar, spinor and gluon loop contributions to the one-loop vertex, leading to an extremely compact representation in all cases. The vertex is computed fully off-shell and in dimensionally continued form, so that it can be used as a building block for higher-loop calculations. We find that the Bern-Kosower loop replacement rules, originally derived for the on-shell case, hold off-shell as well. We explain the relation of the structure of this representation to the low-energy effective action, and establish the precise connection with the standard Ball-Chiu decomposition of the vertex. This allows us also to predict that the vanishing of the completely antisymmetric coefficient function S of this decomposition is not a one-loop accident, but persists at higher loop orders. The sum rule found by Binger and Brodsky, which leads to the vanishing of the one-loop vertex in N=4 SYM theory, in the present approach relates to worldline supersymmetry. |
1904.08744 | Ju Wan-Li | Wan-Li Ju and Li Lin Yang | Resummation of soft and Coulomb corrections for $t\bar{t}h$ production
at the LHC | null | null | 10.1007/JHEP06(2019)050 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper, a combined resummation of soft and Coulomb corrections is
performed for the associated production of the Higgs boson with a top quark
pair at the LHC. We illustrate the similarities and critical differences
between this process and the $t\bar{t}$ production process. We show that up to
the next-to-leading power, the total cross section for $t\bar{t}h$ production
admits a similar factorization formula in the threshold limit as that for
$t\bar{t}$ production. This fact, however, is not expected to hold at higher
powers. Based on the factorization formula, we perform the resummation at the
improved next-to-leading logarithmic accuracy, and match to the next-to-leading
order result. This allows us to give NLL$'$+NLO predictions for the total cross
sections at the LHC. We find that the resummation effects enhance the NLO cross
sections by about 6\%, and significantly reduce the scale dependence of the
theoretical predictions.
| [
{
"created": "Thu, 18 Apr 2019 13:02:49 GMT",
"version": "v1"
}
] | 2019-07-24 | [
[
"Ju",
"Wan-Li",
""
],
[
"Yang",
"Li Lin",
""
]
] | In this paper, a combined resummation of soft and Coulomb corrections is performed for the associated production of the Higgs boson with a top quark pair at the LHC. We illustrate the similarities and critical differences between this process and the $t\bar{t}$ production process. We show that up to the next-to-leading power, the total cross section for $t\bar{t}h$ production admits a similar factorization formula in the threshold limit as that for $t\bar{t}$ production. This fact, however, is not expected to hold at higher powers. Based on the factorization formula, we perform the resummation at the improved next-to-leading logarithmic accuracy, and match to the next-to-leading order result. This allows us to give NLL$'$+NLO predictions for the total cross sections at the LHC. We find that the resummation effects enhance the NLO cross sections by about 6\%, and significantly reduce the scale dependence of the theoretical predictions. |
hep-ph/0406020 | Gerhart Seidl | S. Gabriel, S. Nandi, and G. Seidl (Oklahoma State University) | 6D Higgsless Standard Model | 15 pages, 3 figures, discussion of fermion masses added, comment on
scalar degrees of freedom included, references added | Phys.Lett. B603 (2004) 74 | 10.1016/j.physletb.2004.10.009 | OSU-HEP-04-06 | hep-ph | null | We present a 6D Higgsless Standard Model with a realistic gauge sector. The
model uses only the Standard Model gauge group SU(2)xU(1) with the gauge bosons
propagating in flat extra dimensions which are compactified on a rectangle. The
electroweak symmetry is broken by boundary conditions, and the correct
splitting between the W and Z boson masses can be arranged by a suitable choice
of the compactification scales. The higher Kaluza-Klein excitations of the
gauge bosons decouple from the low-energy theory due to dominant brane kinetic
terms. The model has the following two key features compared to 5D models. The
bulk kinetic couplings, responsible for electroweak symmetry breaking using
mixed boundary conditions, are of order the electroweak scale. Moreover, the
agreement with the precision electroweak parameters is improved compared to 5D
warped or flat models. We also argue that the calculability of Higgsless models
can be ameliorated in more than five dimensions.
| [
{
"created": "Tue, 1 Jun 2004 19:43:09 GMT",
"version": "v1"
},
{
"created": "Fri, 11 Jun 2004 19:45:25 GMT",
"version": "v2"
},
{
"created": "Wed, 8 Sep 2004 23:38:58 GMT",
"version": "v3"
},
{
"created": "Mon, 4 Oct 2004 19:29:22 GMT",
"version": "v4"
}
] | 2010-04-05 | [
[
"Gabriel",
"S.",
"",
"Oklahoma State University"
],
[
"Nandi",
"S.",
"",
"Oklahoma State University"
],
[
"Seidl",
"G.",
"",
"Oklahoma State University"
]
] | We present a 6D Higgsless Standard Model with a realistic gauge sector. The model uses only the Standard Model gauge group SU(2)xU(1) with the gauge bosons propagating in flat extra dimensions which are compactified on a rectangle. The electroweak symmetry is broken by boundary conditions, and the correct splitting between the W and Z boson masses can be arranged by a suitable choice of the compactification scales. The higher Kaluza-Klein excitations of the gauge bosons decouple from the low-energy theory due to dominant brane kinetic terms. The model has the following two key features compared to 5D models. The bulk kinetic couplings, responsible for electroweak symmetry breaking using mixed boundary conditions, are of order the electroweak scale. Moreover, the agreement with the precision electroweak parameters is improved compared to 5D warped or flat models. We also argue that the calculability of Higgsless models can be ameliorated in more than five dimensions. |
2305.00069 | Benedetta Belfatto | Benedetta Belfatto, Zurab Berezhiani | Minimally modified Fritzsch texture for quark masses and CKM mixing | null | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The Standard Model does not constrain the form of the Yukawa matrices and
thus the origin of fermion mass hierarchies and mixing pattern remains
puzzling. On the other hand, there are intriguing relations between fermion
masses and mixing angles which may point towards specific textures of Yukawa
matrices. One of the classic hypothesis is the zero texture proposed by
Fritzsch which is, however, excluded by present precision tests since it
predicts a too large value of $|V_{cb}|$ as well as a too small value of the
ratio $|V_{ub}/V_{cb}|$. In this paper we discuss a minimal modification which
still maintains the six zero entries as in the original Fritzsch ansatz. This
modification consists in introducing an asymmetry between the 23 and 32 entries
in the down-quark Yukawa matrix. We show that this flavour structure can
naturally emerge in the context of models with inter-family $SU(3)_H$ symmetry.
We present a detailed analysis of this Fritzsch-like texture by testing its
predictions and showing that it is perfectly compatible with the present
precision data on quark masses and CKM mixing matrix.
| [
{
"created": "Fri, 28 Apr 2023 19:47:36 GMT",
"version": "v1"
}
] | 2023-05-02 | [
[
"Belfatto",
"Benedetta",
""
],
[
"Berezhiani",
"Zurab",
""
]
] | The Standard Model does not constrain the form of the Yukawa matrices and thus the origin of fermion mass hierarchies and mixing pattern remains puzzling. On the other hand, there are intriguing relations between fermion masses and mixing angles which may point towards specific textures of Yukawa matrices. One of the classic hypothesis is the zero texture proposed by Fritzsch which is, however, excluded by present precision tests since it predicts a too large value of $|V_{cb}|$ as well as a too small value of the ratio $|V_{ub}/V_{cb}|$. In this paper we discuss a minimal modification which still maintains the six zero entries as in the original Fritzsch ansatz. This modification consists in introducing an asymmetry between the 23 and 32 entries in the down-quark Yukawa matrix. We show that this flavour structure can naturally emerge in the context of models with inter-family $SU(3)_H$ symmetry. We present a detailed analysis of this Fritzsch-like texture by testing its predictions and showing that it is perfectly compatible with the present precision data on quark masses and CKM mixing matrix. |
hep-ph/0701262 | Mei Huang | Mei Huang | Unconventional Color Superconductor | 4 pages, to appear in the proceedings of the 19th International
Conference on Ultrarelativistic Nucleus-Nucleus Collisions: Quark Matter 2006
(QM 2006), Shanghai, China, 14-20 Nov 2006 | J.Phys.G34:S659-662,2007 | 10.1088/0954-3899/34/8/S67 | null | hep-ph | null | Superfluidity or superconductivity with mismatched Fermi momenta appears in
many systems such as charge neutral dense quark matter, asymmetric nuclear
matter, and in imbalanced cold atomic gases. The mismatch plays the role of
breaking the Cooper pairing, and the pair-breaking state cannot be properly
described in the framework of standard BCS theory. I give a brief review on
recent theoretical development in understanding unconventional color
superconductivity, including gapless color superconductor, the chromomagnetic
instabilities and the Higgs instability in the gapless phase. I also introduce
a possible new framework for describing unconventional color superconductor.
| [
{
"created": "Wed, 31 Jan 2007 03:40:07 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Huang",
"Mei",
""
]
] | Superfluidity or superconductivity with mismatched Fermi momenta appears in many systems such as charge neutral dense quark matter, asymmetric nuclear matter, and in imbalanced cold atomic gases. The mismatch plays the role of breaking the Cooper pairing, and the pair-breaking state cannot be properly described in the framework of standard BCS theory. I give a brief review on recent theoretical development in understanding unconventional color superconductivity, including gapless color superconductor, the chromomagnetic instabilities and the Higgs instability in the gapless phase. I also introduce a possible new framework for describing unconventional color superconductor. |
hep-ph/0311078 | Sannino Francesco | Agnes Mocsy, Francesco Sannino and Kimmo Tuominen | Confinement, Chiral Symmetry and Hadrons | Presented at the Institute for Particle Physics Phenomenology Light
Cone Workshop, Hadrons and Beyond (LC03), Grey College, University of Durham,
5-9 August 2003 | null | null | null | hep-ph | null | The Polyakov loop is the appropriate deconfinement order parameter for
Yang-Mills theories without quarks or with quarks in the adjoint representation
of the gauge group. However it is not a physical state of the theory so the
information regarding the center group symmetry must be transferred to the
physical states. We briefly review how this transfer of information takes
place. When adding quarks the center group is no longer a symmetry for matter
in the fundamental representation. This feature allows us to explain why color
deconfines when chiral symmetry is restored in hot gauge theories with massless
quarks. For quarks in the adjoint representation we show that while
deconfinement and the chiral transition do not coincide, entanglement between
them is still present. Finally, we discuss also the chemical potential driven
phase transition.
| [
{
"created": "Thu, 6 Nov 2003 13:13:54 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Mocsy",
"Agnes",
""
],
[
"Sannino",
"Francesco",
""
],
[
"Tuominen",
"Kimmo",
""
]
] | The Polyakov loop is the appropriate deconfinement order parameter for Yang-Mills theories without quarks or with quarks in the adjoint representation of the gauge group. However it is not a physical state of the theory so the information regarding the center group symmetry must be transferred to the physical states. We briefly review how this transfer of information takes place. When adding quarks the center group is no longer a symmetry for matter in the fundamental representation. This feature allows us to explain why color deconfines when chiral symmetry is restored in hot gauge theories with massless quarks. For quarks in the adjoint representation we show that while deconfinement and the chiral transition do not coincide, entanglement between them is still present. Finally, we discuss also the chemical potential driven phase transition. |
hep-ph/0202122 | Alexander Dolgov | A.D. Dolgov | Neutrinos in cosmology | 379 pages, 29 figures, to be published in Phys. Repts Criticism,
comments, and suggestions are taken into account; 1 figure and about 40
references are added | Phys.Rept. 370 (2002) 333-535 | 10.1016/S0370-1573(02)00139-4 | INFN-FE, 13 Feb, 2002 | hep-ph astro-ph | null | Cosmological implications of neutrinos are reviewed. The following subjects
are discussed at a different level of scrutiny: cosmological limits on neutrino
mass, neutrinos and primordial nucleosynthesis, cosmological constraints on
unstable neutrinos, lepton asymmetry of the universe, impact of neutrinos on
cosmic microwave radiation, neutrinos and the large scale structure of the
universe, neutrino oscillations in the early universe, baryo/lepto-genesis and
neutrinos, neutrinos and high energy cosmic rays, and briefly some more exotic
subjects: neutrino balls, mirror neutrinos, and neutrinos from large extra
dimensions.
| [
{
"created": "Wed, 13 Feb 2002 15:46:20 GMT",
"version": "v1"
},
{
"created": "Fri, 19 Apr 2002 20:15:29 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Dolgov",
"A. D.",
""
]
] | Cosmological implications of neutrinos are reviewed. The following subjects are discussed at a different level of scrutiny: cosmological limits on neutrino mass, neutrinos and primordial nucleosynthesis, cosmological constraints on unstable neutrinos, lepton asymmetry of the universe, impact of neutrinos on cosmic microwave radiation, neutrinos and the large scale structure of the universe, neutrino oscillations in the early universe, baryo/lepto-genesis and neutrinos, neutrinos and high energy cosmic rays, and briefly some more exotic subjects: neutrino balls, mirror neutrinos, and neutrinos from large extra dimensions. |
hep-ph/0007307 | Georg Weiglein | S. Heinemeyer and G. Weiglein | Higgs-mass predictions and electroweak precision observables in the
Standard Model and the MSSM | 7 pages, 6 figures, to appear in the proceedings of the 5th Zeuthen
Workshop on Elementary Particle Theory ``Loops and Legs in Quantum Field
Theory'', Bastei/K\"onigstein, April 9-14, 2000 | Nucl.Phys.Proc.Suppl. 89 (2000) 216-221 | 10.1016/S0920-5632(00)00846-X | CERN-TH/2000-225, DESY 00-108 | hep-ph | null | Higher-order results for electroweak precision observables in the Standard
Model are analyzed in view of the experimental accuracies achievable at the
present and the next generation of colliders, and the indirect prediction of
the Higgs-boson mass from the precision data is discussed. Within the MSSM,
two-loop results for the lightest CP-even Higgs-boson mass are confronted with
the exclusion limits from LEP. Possible precision tests of the MSSM at a future
linear collider are furthermore investigated.
| [
{
"created": "Wed, 26 Jul 2000 21:28:04 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Heinemeyer",
"S.",
""
],
[
"Weiglein",
"G.",
""
]
] | Higher-order results for electroweak precision observables in the Standard Model are analyzed in view of the experimental accuracies achievable at the present and the next generation of colliders, and the indirect prediction of the Higgs-boson mass from the precision data is discussed. Within the MSSM, two-loop results for the lightest CP-even Higgs-boson mass are confronted with the exclusion limits from LEP. Possible precision tests of the MSSM at a future linear collider are furthermore investigated. |
hep-ph/9712381 | Heinrich Paes | H. P\"as (for the Heidelberg double beta group) | Search for New Physics with Neutrinoless Double Beta Decay | Based on talks presented at the Int. Europhysics Conference on
High-Energy Physics, Jerusalem, August 19-26, 1997 and TAUP97, Gran Sasso,
Sept. 7-11 1997, 4 pages, Latex, 1 figure, requires espcrc2.sty | Nucl.Phys.Proc.Suppl. 70 (1999) 242-245 | 10.1016/S0920-5632(98)00428-9 | null | hep-ph hep-ex nucl-ex nucl-th | null | Neutrinoless double beta decay ($0\nu\beta\beta$) is one of the most
sensitive approaches to test particle physics beyond the standard model. During
the last years, besides the most restrictive limit on the effective Majorana
neutrino mass, the analysis of new contributions by the Heidelberg group led to
bounds on left-right-symmetric models, leptoquarks and R-parity violating
models competitive to recent accelerator limits, which are of special interest
in view of the HERA anomaly at large $Q^2$ and $x$. These new results deduced
from the Heidelberg-Moscow double beta decay experiment are reviewed. Also an
outlook on the future of double beta decay, the GENIUS proposal, is given.
| [
{
"created": "Mon, 15 Dec 1997 13:49:39 GMT",
"version": "v1"
}
] | 2015-06-25 | [
[
"Päs",
"H.",
"",
"for the Heidelberg double beta group"
]
] | Neutrinoless double beta decay ($0\nu\beta\beta$) is one of the most sensitive approaches to test particle physics beyond the standard model. During the last years, besides the most restrictive limit on the effective Majorana neutrino mass, the analysis of new contributions by the Heidelberg group led to bounds on left-right-symmetric models, leptoquarks and R-parity violating models competitive to recent accelerator limits, which are of special interest in view of the HERA anomaly at large $Q^2$ and $x$. These new results deduced from the Heidelberg-Moscow double beta decay experiment are reviewed. Also an outlook on the future of double beta decay, the GENIUS proposal, is given. |
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