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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
2209.14672
|
Vo Quoc Phong
|
Vo Quoc Phong, Nguyen Minh Anh and Hoang Ngoc Long
|
Dual electroweak phase transition in the two-Higgs-doublet model with
the $S_3$ discrete symmetry
|
47 pages, 11 figures; matches journal version (PRD)
|
Phys. Rev. D 107, 035020 (2023)
|
10.1103/PhysRevD.107.035020
| null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
In this work, dual electroweak phase transition (EWPT) consisting of two
phases, is carefully studied in the two-Higgs-doublet model with the $S_3$
discrete symmetry. The role of $S_3$ here is to further separate the stages of
the electroweak phase transition, compared to that of the original
two-Higgs-doublet model (2HDM). The strength of the electroweak phase
transition $(S)$ in the model under consideration is large enough for the
first-order EWPT, specifically $1 < S < 2.8$. The ratio between the two vacuum
expectation values (VEVs), $\tan\beta = v_2/v_1$, is proven to have no effects
on the strength of the phase transition. This ratio only affects the mass
domain that causes the first-order phase transition. Furthermore, in this paper
we will show clearly that when studying the EWPT in models of more than one
scalar field that generates masses, one needs to analyze the problem of phase
transition under multiple stages. In other words, the effect of the first stage
of symmetry breaking to the second one, is to simplify by suggestion that
vacuum expectation value of the Higgs boson responsible for the initial stage
is proportional to that of the field for the next stage.
|
[
{
"created": "Thu, 29 Sep 2022 10:26:23 GMT",
"version": "v1"
},
{
"created": "Tue, 21 Feb 2023 15:43:27 GMT",
"version": "v2"
}
] |
2023-02-22
|
[
[
"Phong",
"Vo Quoc",
""
],
[
"Anh",
"Nguyen Minh",
""
],
[
"Long",
"Hoang Ngoc",
""
]
] |
In this work, dual electroweak phase transition (EWPT) consisting of two phases, is carefully studied in the two-Higgs-doublet model with the $S_3$ discrete symmetry. The role of $S_3$ here is to further separate the stages of the electroweak phase transition, compared to that of the original two-Higgs-doublet model (2HDM). The strength of the electroweak phase transition $(S)$ in the model under consideration is large enough for the first-order EWPT, specifically $1 < S < 2.8$. The ratio between the two vacuum expectation values (VEVs), $\tan\beta = v_2/v_1$, is proven to have no effects on the strength of the phase transition. This ratio only affects the mass domain that causes the first-order phase transition. Furthermore, in this paper we will show clearly that when studying the EWPT in models of more than one scalar field that generates masses, one needs to analyze the problem of phase transition under multiple stages. In other words, the effect of the first stage of symmetry breaking to the second one, is to simplify by suggestion that vacuum expectation value of the Higgs boson responsible for the initial stage is proportional to that of the field for the next stage.
|
hep-ph/9211250
| null |
N. G. Stefanis and M. Bergmann
|
On the Nucleon Distribution Amplitude: The Heterotic Solution
|
15 pages, RUB-TPII-21/92 Preprint
|
Phys.Rev.D47:3685-3689,1993
|
10.1103/PhysRevD.47.R3685
| null |
hep-ph
| null |
We present a new nucleon distribution amplitude which amalgamates features of
the Chernyak-Ogloblin-Zhitnitsky model with those of the Gari-Stefanis model.
This "heterotic" solution provides the possibility to have asymptotically a
small ratio \hbox{$\vert G_{M}^{n}\vert/G_{M}^{p}\le 0.1$}, while fulfilling
most of the sum-rule requirements up to the third order. Using this nucleon
distribution amplitude we calculate the electromagnetic and weak nucleon form
factors, the transition form factor $\gamma p \Delta^{+}$ and the decay widths
of the charmonium levels $^3S_{1}$, $^3P_{1}$, and $^3P_{2}$ into $p\bar p$.
The agreement with the available data is remarkable in all cases.
|
[
{
"created": "Mon, 16 Nov 1992 17:10:00 GMT",
"version": "v1"
}
] |
2009-12-30
|
[
[
"Stefanis",
"N. G.",
""
],
[
"Bergmann",
"M.",
""
]
] |
We present a new nucleon distribution amplitude which amalgamates features of the Chernyak-Ogloblin-Zhitnitsky model with those of the Gari-Stefanis model. This "heterotic" solution provides the possibility to have asymptotically a small ratio \hbox{$\vert G_{M}^{n}\vert/G_{M}^{p}\le 0.1$}, while fulfilling most of the sum-rule requirements up to the third order. Using this nucleon distribution amplitude we calculate the electromagnetic and weak nucleon form factors, the transition form factor $\gamma p \Delta^{+}$ and the decay widths of the charmonium levels $^3S_{1}$, $^3P_{1}$, and $^3P_{2}$ into $p\bar p$. The agreement with the available data is remarkable in all cases.
|
1407.8188
|
Joachim Brod
|
Joachim Brod, Jure Drobnak, Alexander L. Kagan, Emmanuel Stamou, Jure
Zupan
|
Stealth QCD-like Strong Interactions and the t-tbar Asymmetry
|
25 pages, 14 figures
|
Phys. Rev. D 91, 095009 (2015)
|
10.1103/PhysRevD.91.095009
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We show that a new strongly interacting sector can produce large enhancements
of the t-tbar asymmetries at the Tevatron. The Standard Model is extended by a
new vector-like flavor triplet of fermions and one heavy scalar, all charged
under a hypercolor gauge group SU(3) HC. This simple extension results in a
number of new resonances. The predictions of our model are rather rigid once a
small number of UV parameters are fixed, since all the strong dynamics can be
directly taken over from our understanding of QCD dynamics. Despite the rather
low hypercolor confinement scale of ~100 GeV, the new strongly interacting
sector is stealth. It is shielded from present direct and indirect NP searches
since the light resonances are QCD singlets, whereas the production of the
heavier QCD colored resonances leads predominantly to high multiplicity final
states. Improved searches can potentially be devised using top tagged final
states or decays into a small number of hypercolor pions.
|
[
{
"created": "Wed, 30 Jul 2014 20:00:14 GMT",
"version": "v1"
}
] |
2015-05-20
|
[
[
"Brod",
"Joachim",
""
],
[
"Drobnak",
"Jure",
""
],
[
"Kagan",
"Alexander L.",
""
],
[
"Stamou",
"Emmanuel",
""
],
[
"Zupan",
"Jure",
""
]
] |
We show that a new strongly interacting sector can produce large enhancements of the t-tbar asymmetries at the Tevatron. The Standard Model is extended by a new vector-like flavor triplet of fermions and one heavy scalar, all charged under a hypercolor gauge group SU(3) HC. This simple extension results in a number of new resonances. The predictions of our model are rather rigid once a small number of UV parameters are fixed, since all the strong dynamics can be directly taken over from our understanding of QCD dynamics. Despite the rather low hypercolor confinement scale of ~100 GeV, the new strongly interacting sector is stealth. It is shielded from present direct and indirect NP searches since the light resonances are QCD singlets, whereas the production of the heavier QCD colored resonances leads predominantly to high multiplicity final states. Improved searches can potentially be devised using top tagged final states or decays into a small number of hypercolor pions.
|
2209.10165
|
Alexey Nefediev
|
Christoph Hanhart, Alexey Nefediev
|
Do near-threshold molecular states mix with neighbouring $\bar QQ$
states?
|
13 pages, 4 figures, to appear in Phys.Rev.D
|
Phys. Rev. D 106, 114003 (2022)
|
10.1103/PhysRevD.106.114003
| null |
hep-ph hep-ex hep-lat
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The last two decades are marked by a renaissance in hadronic spectroscopy
caused by the arrival of vast experimental information on exotic states in the
spectrum of charmonium and bottomonium. Most of such states have properties at
odds with the predictions of the quark model and reside very close to strong
hadronic thresholds. Prominent examples are provided by the glorious $X(3872)$
charmonium-like state and the doubly charmed tetraquark $T_{cc}^+$ with the
masses within less than 1 MeV from the $D\bar{D}^*$ and $DD^*$ open-charm
thresholds, respectively. The universality of this feature hints towards the
existence of a general pattern for such exotic states. In this work we discuss
a possible generic mechanism for the formation of near-threshold molecular
states as a result of the strong coupling of compact quark states with a
hadronic continuum channel. The compact states that survive the strong coupling
limit decouple from the continuum channel and therefore also from the formed
hadronic molecule - if realised this scenario would provide a justification to
treat hadronic molecules isolated, ignoring the possible influence from
surrounding, compact quark-model states. We confront the phenomenology of the
$D_{s1}(2460)$ and $D_{s1}(2536)$ with this picture and find consistency,
although other explanations remain possible for those states.
|
[
{
"created": "Wed, 21 Sep 2022 07:56:00 GMT",
"version": "v1"
},
{
"created": "Tue, 22 Nov 2022 11:05:25 GMT",
"version": "v2"
}
] |
2022-12-02
|
[
[
"Hanhart",
"Christoph",
""
],
[
"Nefediev",
"Alexey",
""
]
] |
The last two decades are marked by a renaissance in hadronic spectroscopy caused by the arrival of vast experimental information on exotic states in the spectrum of charmonium and bottomonium. Most of such states have properties at odds with the predictions of the quark model and reside very close to strong hadronic thresholds. Prominent examples are provided by the glorious $X(3872)$ charmonium-like state and the doubly charmed tetraquark $T_{cc}^+$ with the masses within less than 1 MeV from the $D\bar{D}^*$ and $DD^*$ open-charm thresholds, respectively. The universality of this feature hints towards the existence of a general pattern for such exotic states. In this work we discuss a possible generic mechanism for the formation of near-threshold molecular states as a result of the strong coupling of compact quark states with a hadronic continuum channel. The compact states that survive the strong coupling limit decouple from the continuum channel and therefore also from the formed hadronic molecule - if realised this scenario would provide a justification to treat hadronic molecules isolated, ignoring the possible influence from surrounding, compact quark-model states. We confront the phenomenology of the $D_{s1}(2460)$ and $D_{s1}(2536)$ with this picture and find consistency, although other explanations remain possible for those states.
|
2404.13618
|
Alexander A. Osipov
|
A.A. Osipov
|
Ratios of the light quark masses: Cubic curve vs ellipse
|
8 pages, 2 figuras, 2 tables, Version accepted for publication in
Phys. Rev. D
| null | null | null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
The bounds on the light quark masses are obtained by fitting the squares of
pseudoscalar meson masses $m_\pi^2$ and $m_K^2$ to second order in $1/N_c$
expansion. The result is an algebraic cubic curve whose coefficients are the
known Weinberg values for the quark mass ratios $m_u/m_d$ and $m_s/m_d$.
Additional restrictions arise when using the ratio $m_s/m_{ud}=27.23(10)$
quoted by FLAG for lattice simulations with four quark flavors. This provides a
tight constraint on the ratio $m_u/m_d = 0.455(8)$.
|
[
{
"created": "Sun, 21 Apr 2024 10:55:43 GMT",
"version": "v1"
},
{
"created": "Wed, 26 Jun 2024 15:04:10 GMT",
"version": "v2"
}
] |
2024-06-27
|
[
[
"Osipov",
"A. A.",
""
]
] |
The bounds on the light quark masses are obtained by fitting the squares of pseudoscalar meson masses $m_\pi^2$ and $m_K^2$ to second order in $1/N_c$ expansion. The result is an algebraic cubic curve whose coefficients are the known Weinberg values for the quark mass ratios $m_u/m_d$ and $m_s/m_d$. Additional restrictions arise when using the ratio $m_s/m_{ud}=27.23(10)$ quoted by FLAG for lattice simulations with four quark flavors. This provides a tight constraint on the ratio $m_u/m_d = 0.455(8)$.
|
1208.0705
|
Marco Monteno
|
W. M. Alberico, A. Beraudo, A. De Pace, M. Monteno, A. Molinari, M.
Nardi, F. Prino
|
Heavy flavor production in pp and AA collisions at the LHC
|
4 pages, 6 figures (eps files), submitted for publication in the
proceedings of "Hard Probes 2012", 27 May - 1 June 2012, Cagliari (Italy)
| null | null | null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
A refined version of a multi-step calculation of heavy-flavor observables in
pp and AA collisions has been developed, based on pQCD at NLO accuracy followed
by parton shower evolution to describe heavy-quark production and on the
relativistic Langevin equation to describe their stochastic evolution in the
QCD plasma. Then, hadronization is modeled through an implementation of
fragmentation functions based on pQCD and constrained by $e^{+}e^{-}$ collider
data. Results of our calculations can be compared with recent measurements
performed at the LHC in Pb--Pb collisions at $\sqrt{s_{NN}}$=2.76 TeV: nuclear
modification factor $R_{AA}$ of the $p_{T}$ spectra at mid-rapidity of
heavy-flavor decay electrons and of exclusively reconstructed open-charm mesons
at different centralities, as well as their elliptic-flow $v_{2}$($p_{T}$) in
semi-central collisions. To test the validity of our setup for such studies,
its predictions are also checked against the $p_{T}$ spectra measured in pp
collisions at $\sqrt{s}$=7 TeV and 2.76 TeV.
|
[
{
"created": "Fri, 3 Aug 2012 10:34:14 GMT",
"version": "v1"
}
] |
2012-08-06
|
[
[
"Alberico",
"W. M.",
""
],
[
"Beraudo",
"A.",
""
],
[
"De Pace",
"A.",
""
],
[
"Monteno",
"M.",
""
],
[
"Molinari",
"A.",
""
],
[
"Nardi",
"M.",
""
],
[
"Prino",
"F.",
""
]
] |
A refined version of a multi-step calculation of heavy-flavor observables in pp and AA collisions has been developed, based on pQCD at NLO accuracy followed by parton shower evolution to describe heavy-quark production and on the relativistic Langevin equation to describe their stochastic evolution in the QCD plasma. Then, hadronization is modeled through an implementation of fragmentation functions based on pQCD and constrained by $e^{+}e^{-}$ collider data. Results of our calculations can be compared with recent measurements performed at the LHC in Pb--Pb collisions at $\sqrt{s_{NN}}$=2.76 TeV: nuclear modification factor $R_{AA}$ of the $p_{T}$ spectra at mid-rapidity of heavy-flavor decay electrons and of exclusively reconstructed open-charm mesons at different centralities, as well as their elliptic-flow $v_{2}$($p_{T}$) in semi-central collisions. To test the validity of our setup for such studies, its predictions are also checked against the $p_{T}$ spectra measured in pp collisions at $\sqrt{s}$=7 TeV and 2.76 TeV.
|
hep-ph/0003300
|
Jiri Chyla
|
Jiri Chyla and Marek Tasevsky
|
The relevance of $\gamma_L^*$ in hard collisions of virtual photons
|
13 pages, Latex, 5 eps figures
|
Eur.Phys.J.C16:471-479,2000
|
10.1007/s100520000426
|
PRA-HEP/00-01
|
hep-ph
| null |
We explore the relevance of extending the concept of the structure to the
longitudinally polarized virtual photon involved in hard collisions. We show
that for moderate photon virtualities and in the kinematical region accessible
in current experiments at HERA and LEP, the contributions of its longitudinal
polarization to hard collisions are sizable and should be taken into account as
part of the resolved photon component.
|
[
{
"created": "Thu, 30 Mar 2000 15:01:47 GMT",
"version": "v1"
}
] |
2009-01-07
|
[
[
"Chyla",
"Jiri",
""
],
[
"Tasevsky",
"Marek",
""
]
] |
We explore the relevance of extending the concept of the structure to the longitudinally polarized virtual photon involved in hard collisions. We show that for moderate photon virtualities and in the kinematical region accessible in current experiments at HERA and LEP, the contributions of its longitudinal polarization to hard collisions are sizable and should be taken into account as part of the resolved photon component.
|
1503.05106
|
Daniele Binosi
|
Daniele Binosi
|
The two-, three- and four-gluon sector of QCD in the Landau gauge
|
13 pages, 7 figures. Talk given at Discrete 2014 - Fourth Symposium
on Prospects in the Physics of Discrete Symmetries. 2-6 December, 2014 -
King's College, London, England
| null |
10.1088/1742-6596/631/1/012066
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Due to the nonperturbative masslessness of the ghost field, ghost loops that
contribute to gluon Green's functions in the Landau gauge display infrared
divergences, akin to those one would encounter in a conventional perturbative
treatment. This is in sharp contrast with gluon loops, in which the
perturbative divergences are tamed by the dynamical generation of a gluon mass
acting as an effective infrared cutoff. In this paper, after reviewing the full
nonperturbative origin of this divergence in the two-gluon sector, we discuss
its implications for the three- and four-gluon sector, showing in particular
that some of the form factors characterizing the corresponding Green's
functions are bound to diverge in the infrared.
|
[
{
"created": "Tue, 17 Mar 2015 16:00:19 GMT",
"version": "v1"
}
] |
2015-09-02
|
[
[
"Binosi",
"Daniele",
""
]
] |
Due to the nonperturbative masslessness of the ghost field, ghost loops that contribute to gluon Green's functions in the Landau gauge display infrared divergences, akin to those one would encounter in a conventional perturbative treatment. This is in sharp contrast with gluon loops, in which the perturbative divergences are tamed by the dynamical generation of a gluon mass acting as an effective infrared cutoff. In this paper, after reviewing the full nonperturbative origin of this divergence in the two-gluon sector, we discuss its implications for the three- and four-gluon sector, showing in particular that some of the form factors characterizing the corresponding Green's functions are bound to diverge in the infrared.
|
1904.10308
|
Desmond Villalba
|
Nobuchika Okada, Digesh Raut, and Desmond Villalba
|
Fermion Mass Hierarchy and Phenomenology in the 5D Domain Wall Standard
Model
|
17 pages, 3 figures. arXiv admin note: text overlap with
arXiv:1801.03007
| null |
10.1007/JHEP10(2019)259
| null |
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We have recently proposed a setup of the "Domain-Wall Standard Model" in 5D
spacetime, where all the Standard Model (SM) fields are localized in certain
domains of the extra 5th dimension. Utilizing this setup, we attempt to solve
the fermion mass hierarchy problem of the SM. The mass hierarchy can be
naturally explained by suitably distributing the fermions in different
positions along the extra dimension. Due to these different localization
points, the effective 4D gauge couplings of Kaluza-Klein (KK) mode gauge bosons
to the SM fermions become non-universal. As a result, our model is severely
constrained by the Flavor Changing Neutral Current (FCNC) measurements. We find
two interesting cases in which our model is phenomenologically viable: (1) the
KK-mode of the SM gauge bosons are extremely heavy and unlikely to be produced
at the Large Hadron Collider (LHC), while future FCNC measurements can reveal
the existence of these heavy modes. (2) the width of the localized SM fermions
is very narrow, leading to almost universal 4D KK-mode gauge couplings. In this
case, the FCNC constraints can be easily avoided even if a KK gauge boson mass
lies at the TeV scale. Such a light KK gauge boson can be searched at the LHC
in the near future.
|
[
{
"created": "Sun, 21 Apr 2019 23:17:50 GMT",
"version": "v1"
},
{
"created": "Sun, 15 Sep 2019 21:32:21 GMT",
"version": "v2"
}
] |
2020-01-08
|
[
[
"Okada",
"Nobuchika",
""
],
[
"Raut",
"Digesh",
""
],
[
"Villalba",
"Desmond",
""
]
] |
We have recently proposed a setup of the "Domain-Wall Standard Model" in 5D spacetime, where all the Standard Model (SM) fields are localized in certain domains of the extra 5th dimension. Utilizing this setup, we attempt to solve the fermion mass hierarchy problem of the SM. The mass hierarchy can be naturally explained by suitably distributing the fermions in different positions along the extra dimension. Due to these different localization points, the effective 4D gauge couplings of Kaluza-Klein (KK) mode gauge bosons to the SM fermions become non-universal. As a result, our model is severely constrained by the Flavor Changing Neutral Current (FCNC) measurements. We find two interesting cases in which our model is phenomenologically viable: (1) the KK-mode of the SM gauge bosons are extremely heavy and unlikely to be produced at the Large Hadron Collider (LHC), while future FCNC measurements can reveal the existence of these heavy modes. (2) the width of the localized SM fermions is very narrow, leading to almost universal 4D KK-mode gauge couplings. In this case, the FCNC constraints can be easily avoided even if a KK gauge boson mass lies at the TeV scale. Such a light KK gauge boson can be searched at the LHC in the near future.
|
hep-ph/9703308
|
Bodo Lampe
|
Bodo Lampe and Andreas Ruffing
|
The First Moment of delta g(x) -- a Comparative Study
|
latex file and 8 figures
| null | null |
MPI-PhT/97-14
|
hep-ph
| null |
The sensititivity of various future polarization experiments to the first
moment Delta g of the polarized gluon density is elucidated in detail. It is
shown to what extent the first moment can be extracted from the future data as
compared to the higher moments. We concentrate on two processes which in the
near future will become an important source of information on the polarized
gluon density, namely the photoproduction of open charm to be studied at CERN
(COMPASS) and SLAC and the production of direct photons at RHIC.
|
[
{
"created": "Wed, 12 Mar 1997 18:31:11 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Lampe",
"Bodo",
""
],
[
"Ruffing",
"Andreas",
""
]
] |
The sensititivity of various future polarization experiments to the first moment Delta g of the polarized gluon density is elucidated in detail. It is shown to what extent the first moment can be extracted from the future data as compared to the higher moments. We concentrate on two processes which in the near future will become an important source of information on the polarized gluon density, namely the photoproduction of open charm to be studied at CERN (COMPASS) and SLAC and the production of direct photons at RHIC.
|
1312.7680
|
Kengo Shimada
|
Satoshi Iso, Kengo Shimada and Masato Yamanaka
|
Kadanoff-Baym approach to the thermal resonant leptogenesis
|
51 pages + appendices (46 pages), 5 figures; typos corrected,
references added
| null |
10.1007/JHEP04(2014)062
|
KEK-TH-1697
|
hep-ph astro-ph.CO nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Using the non-equilibrium Green function method (Kadanoff-Baym equations) in
the expanding universe, we investigate evolution of the lepton number asymmetry
when the right-handed (RH) neutrinos have almost degenerate masses
$|M_i^2-M_j^2| \ll M_i^2$. The resonantly enhanced $CP$-violating parameter
$\varepsilon_i$ associated with the decay of the RH neutrino $N_i$ is obtained.
It is proportional to an enhancement factor $(M_i^2-M_j^2) M_i \Gamma_j/
((M_i^2-M_j^2)^2 +R_{ij}^2)$ with the regulator $R_{ij}=M_i \Gamma_i+M_j
\Gamma_j$. The result is consistent with the previous result obtained by Garny
et al., in a constant background with an out-of-equilibrium initial state. We
discuss the origin of such a regulator, and why it is not like $R_{ij}=M_i
\Gamma_i-M_j \Gamma_j$.
|
[
{
"created": "Mon, 30 Dec 2013 11:13:18 GMT",
"version": "v1"
},
{
"created": "Fri, 17 Jan 2014 11:59:14 GMT",
"version": "v2"
}
] |
2015-06-18
|
[
[
"Iso",
"Satoshi",
""
],
[
"Shimada",
"Kengo",
""
],
[
"Yamanaka",
"Masato",
""
]
] |
Using the non-equilibrium Green function method (Kadanoff-Baym equations) in the expanding universe, we investigate evolution of the lepton number asymmetry when the right-handed (RH) neutrinos have almost degenerate masses $|M_i^2-M_j^2| \ll M_i^2$. The resonantly enhanced $CP$-violating parameter $\varepsilon_i$ associated with the decay of the RH neutrino $N_i$ is obtained. It is proportional to an enhancement factor $(M_i^2-M_j^2) M_i \Gamma_j/ ((M_i^2-M_j^2)^2 +R_{ij}^2)$ with the regulator $R_{ij}=M_i \Gamma_i+M_j \Gamma_j$. The result is consistent with the previous result obtained by Garny et al., in a constant background with an out-of-equilibrium initial state. We discuss the origin of such a regulator, and why it is not like $R_{ij}=M_i \Gamma_i-M_j \Gamma_j$.
|
hep-ph/9207244
|
Dave Bennett
|
David P. Bennett and Sun Hong Rhie
|
COBE's Constraints on the Global Monopole and Texture Theories of Cosmic
Structure Formation
|
8 pages, 5 figures (not included, but available by mail),
CfPA-TH-92-21
|
Astrophys.J. 406 (1993) L7-L10
|
10.1086/186773
| null |
hep-ph astro-ph
| null |
We report on a calculation of large scale anisotropy in the cosmic microwave
background radiation in the global monopole and texture models for cosmic
structure formation. We have evolved the six component linear gravitational
field along with the monopole or texture scalar fields numerically in an
expanding universe and performed the Sachs-Wolfe integrals directly on the
calculated gravitational fields. On scales $> 7^\circ$, we find a Gaussian
distribution with an approximately scale invariant fluctuation spectrum. The
$\Delta T/T$ amplitude is a factor of 4-5 larger than the prediction of the
standard CDM model with the same Hubble constant and density fluctuation
normalization. The recently reported COBE-DMR results imply that global
monopole and texture models require high bias factors or a large Hubble
constant in contrast to standard CDM which requires very low $H_0$ and bias
values. For $H_0 = 70 {\rm {km\over sec} Mpc^{-1}}$, we find that normalizing
to the COBE results implies $b_8 \simeq 3.2\pm 1.4$ (95\% c.l.). If we restrict
ourselves to the range of bias factors thought to be reasonable before the
announcement of the COBE results, $1.5 \lsim b_8 \lsim 2.5$, then it is fair to
conclude that global monopoles and textures are consistent with the COBE
results and are a {\it better} fit than Standard CDM.
|
[
{
"created": "Thu, 16 Jul 1992 20:40:01 GMT",
"version": "v1"
}
] |
2009-10-22
|
[
[
"Bennett",
"David P.",
""
],
[
"Rhie",
"Sun Hong",
""
]
] |
We report on a calculation of large scale anisotropy in the cosmic microwave background radiation in the global monopole and texture models for cosmic structure formation. We have evolved the six component linear gravitational field along with the monopole or texture scalar fields numerically in an expanding universe and performed the Sachs-Wolfe integrals directly on the calculated gravitational fields. On scales $> 7^\circ$, we find a Gaussian distribution with an approximately scale invariant fluctuation spectrum. The $\Delta T/T$ amplitude is a factor of 4-5 larger than the prediction of the standard CDM model with the same Hubble constant and density fluctuation normalization. The recently reported COBE-DMR results imply that global monopole and texture models require high bias factors or a large Hubble constant in contrast to standard CDM which requires very low $H_0$ and bias values. For $H_0 = 70 {\rm {km\over sec} Mpc^{-1}}$, we find that normalizing to the COBE results implies $b_8 \simeq 3.2\pm 1.4$ (95\% c.l.). If we restrict ourselves to the range of bias factors thought to be reasonable before the announcement of the COBE results, $1.5 \lsim b_8 \lsim 2.5$, then it is fair to conclude that global monopoles and textures are consistent with the COBE results and are a {\it better} fit than Standard CDM.
|
1501.04381
|
Jubin Park
|
Jubin Park
|
Low scale quantum gravity in gauge-Higgs unified models
|
14 pages, containing 4 figures and 3 tables
| null | null |
CNU-HEP-15-02
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider the scale at which gravity becomes strong in linearized General
Relativity coupled to the gauge-Higgs unified(GHU) model. We also discuss the
unitarity of S-matrix in the same framework. The Kaluza-Klein(KK) gauge bosons,
KK scalars and KK fermions in the GHU models can drastically change the strong
gravity scale and the unitarity violation scale. In particular we consider two
models GHU_SM and GHU_MSSM which have the zero modes corresponding to the
particle content of the Standard Model and the Minimal Supersymmetric Standard
Model, respectively. We find that the strong gravity scale could be lowered as
much as 10^13 (10^14) GeV in the GHU_SM (GHU_MSSM) for one extra dimension
taking 1 TeV as the compactification scale. It is also shown that these scales
are proportional to the inverse of the number of extra dimensions d. In the
d=10 case, they could be lowered up to 10^5 GeV for both models. We also find
that the maximum compactification scales of extra dimensions quickly converge
into one special scale M_O near Planck scale or equivalently into one common
radius R_0 irrespectively of d as the number of zero modes increases. It may
mean that all extra dimensions emerge with the same radius near Planck scale.
In addition, it is shown that the supersymmetry can help to remove the
discordance between the strong gravity scale and the unitarity violation scale.
|
[
{
"created": "Mon, 19 Jan 2015 03:56:52 GMT",
"version": "v1"
}
] |
2015-01-20
|
[
[
"Park",
"Jubin",
""
]
] |
We consider the scale at which gravity becomes strong in linearized General Relativity coupled to the gauge-Higgs unified(GHU) model. We also discuss the unitarity of S-matrix in the same framework. The Kaluza-Klein(KK) gauge bosons, KK scalars and KK fermions in the GHU models can drastically change the strong gravity scale and the unitarity violation scale. In particular we consider two models GHU_SM and GHU_MSSM which have the zero modes corresponding to the particle content of the Standard Model and the Minimal Supersymmetric Standard Model, respectively. We find that the strong gravity scale could be lowered as much as 10^13 (10^14) GeV in the GHU_SM (GHU_MSSM) for one extra dimension taking 1 TeV as the compactification scale. It is also shown that these scales are proportional to the inverse of the number of extra dimensions d. In the d=10 case, they could be lowered up to 10^5 GeV for both models. We also find that the maximum compactification scales of extra dimensions quickly converge into one special scale M_O near Planck scale or equivalently into one common radius R_0 irrespectively of d as the number of zero modes increases. It may mean that all extra dimensions emerge with the same radius near Planck scale. In addition, it is shown that the supersymmetry can help to remove the discordance between the strong gravity scale and the unitarity violation scale.
|
1006.0983
|
John Mason
|
Yanou Cui, John D. Mason, Lisa Randall
|
General Analysis of Antideuteron Searches for Dark Matter
|
44 pages, 15 Figures
|
JHEP 1011:017,2010
|
10.1007/JHEP11(2010)017
| null |
hep-ph astro-ph.CO
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Low energy cosmic ray antideuterons provide a unique low background channel
for indirect detection of dark matter. We compute the cosmic ray flux of
antideuterons from hadronic annihilations of dark matter for various Standard
Model final states and determine the mass reach of two future experiments
(AMS-02 and GAPS) designed to greatly increase the sensitivity of antideuteron
detection over current bounds. We consider generic models of scalar, fermion,
and massive vector bosons as thermal dark matter, describe their basic features
relevant to direct and indirect detection, and discuss the implications of
direct detection bounds on models of dark matter as a thermal relic. We also
consider specific dark matter candidates and assess their potential for
detection via antideuterons from their hadronic annihilation channels. Since
the dark matter mass reach of the GAPS experiment can be well above 100 GeV, we
find that antideuterons can be a good indirect detection channel for a variety
of thermal relic electroweak scale dark matter candidates, even when the rate
for direct detection is highly suppressed.
|
[
{
"created": "Fri, 4 Jun 2010 20:15:19 GMT",
"version": "v1"
}
] |
2010-11-11
|
[
[
"Cui",
"Yanou",
""
],
[
"Mason",
"John D.",
""
],
[
"Randall",
"Lisa",
""
]
] |
Low energy cosmic ray antideuterons provide a unique low background channel for indirect detection of dark matter. We compute the cosmic ray flux of antideuterons from hadronic annihilations of dark matter for various Standard Model final states and determine the mass reach of two future experiments (AMS-02 and GAPS) designed to greatly increase the sensitivity of antideuteron detection over current bounds. We consider generic models of scalar, fermion, and massive vector bosons as thermal dark matter, describe their basic features relevant to direct and indirect detection, and discuss the implications of direct detection bounds on models of dark matter as a thermal relic. We also consider specific dark matter candidates and assess their potential for detection via antideuterons from their hadronic annihilation channels. Since the dark matter mass reach of the GAPS experiment can be well above 100 GeV, we find that antideuterons can be a good indirect detection channel for a variety of thermal relic electroweak scale dark matter candidates, even when the rate for direct detection is highly suppressed.
|
0710.2457
|
Roman Nevzorov
|
C.D. Froggatt, R. Nevzorov, H. B. Nielsen
|
Multiple point principle as a mechanism for the suppression of FCNC and
CP--violation phenomena in the 2HDM
|
Submitted for the SUSY07 proceedings, 4 pages, LaTeX, 2 eps
figures,CERN preprint number added, references updated
| null | null |
CERN-PH-TH/2007-190
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We argue that multiple point principle (MPP) can be used to ensure CP
conservation and the absence of flavour changing neutral currents within the
two Higgs doublet model (2HDM). We also discuss Higgs phenomenology in the MPP
inspired 2HDM.
|
[
{
"created": "Fri, 12 Oct 2007 19:02:47 GMT",
"version": "v1"
},
{
"created": "Fri, 20 Jun 2008 19:28:33 GMT",
"version": "v2"
}
] |
2008-06-20
|
[
[
"Froggatt",
"C. D.",
""
],
[
"Nevzorov",
"R.",
""
],
[
"Nielsen",
"H. B.",
""
]
] |
We argue that multiple point principle (MPP) can be used to ensure CP conservation and the absence of flavour changing neutral currents within the two Higgs doublet model (2HDM). We also discuss Higgs phenomenology in the MPP inspired 2HDM.
|
hep-ph/9711224
|
Erwin Mirkes
|
E. Mirkes
|
Theory of Jets in Deep Inelastic Scattering
|
Latex, 121 pages, 43 figures. The complete paper, including figures,
is also available via anonymous ftp at ftp://ttpux2.physik.uni-karlsruhe.de/
, or via www at http://www-ttp.physik.uni-karlsruhe.de/cgi-bin/preprints/
| null | null |
TTP97-39
|
hep-ph
| null |
The large center of mass energy and increasing statistical precision for a
wide range of hadronic final state observables at the HERA lepton-proton
collider has provided a detailed testing ground for QCD dynamics. Fully
flexible next-to-leading order calculations are mandatory on the theoretical
side for such tests and will be discussed in detail. Next-to-leading order QCD
predictions for one- and two-jet cross sections in deep inelastic scattering
with complete neutral current ($\gamma^\ast$ and/or $Z$) and charged current
($W^\pm$) exchange together with leading order results for three- and four-jet
final states are presented. The theoretical framework, based on the phase space
slicing method and the use of universal crossing functions, is described in
detail. All analytical formulae necessary for the next-to-leading order
calculations are provided. The numerical results are based on the fully
differential $ep \to n$ jets event generator \docuname which allows to analyze
any infrared and collinear safe observable and general cuts in terms of parton
4-momenta. The importance of higher order corrections is studied for various
jet algorithms. Implications and comparisons with (ongoing) experimental
analyses for jet cross sections at high $Q^2$, the determination of
$\alpha_s(\mu_R)$, the gluon density, power corrections in event shapes and the
associated forward jet production in the low $x$ regime at HERA are discussed.
A study of jet cross sections in polarized electron and polarized proton
collisions shows that dijet events provide a good measurement of the polarized
gluon distribution $\Delta g(x_g)$, in a region, where $x_g \Delta g(x_g)$ is
expected to show a maximum.
|
[
{
"created": "Tue, 4 Nov 1997 10:45:27 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Mirkes",
"E.",
""
]
] |
The large center of mass energy and increasing statistical precision for a wide range of hadronic final state observables at the HERA lepton-proton collider has provided a detailed testing ground for QCD dynamics. Fully flexible next-to-leading order calculations are mandatory on the theoretical side for such tests and will be discussed in detail. Next-to-leading order QCD predictions for one- and two-jet cross sections in deep inelastic scattering with complete neutral current ($\gamma^\ast$ and/or $Z$) and charged current ($W^\pm$) exchange together with leading order results for three- and four-jet final states are presented. The theoretical framework, based on the phase space slicing method and the use of universal crossing functions, is described in detail. All analytical formulae necessary for the next-to-leading order calculations are provided. The numerical results are based on the fully differential $ep \to n$ jets event generator \docuname which allows to analyze any infrared and collinear safe observable and general cuts in terms of parton 4-momenta. The importance of higher order corrections is studied for various jet algorithms. Implications and comparisons with (ongoing) experimental analyses for jet cross sections at high $Q^2$, the determination of $\alpha_s(\mu_R)$, the gluon density, power corrections in event shapes and the associated forward jet production in the low $x$ regime at HERA are discussed. A study of jet cross sections in polarized electron and polarized proton collisions shows that dijet events provide a good measurement of the polarized gluon distribution $\Delta g(x_g)$, in a region, where $x_g \Delta g(x_g)$ is expected to show a maximum.
|
hep-ph/9808245
|
Rainer Dick
|
R. Dick, N. Eschrich and M. Gaul
|
Superstrings and dark matter
|
7 pages, 1 figure, uses iopconf1.sty, to appear in the proceedings of
DARK98, Heidelberg (Germany) 20-24 July 1998
| null | null |
LMU-TPW-98/13, MPI-PhT-98/61
|
hep-ph astro-ph
| null |
We point out that the spectrum and interactions of light states of the
heterotic string indicate a string scale close to the GUT scale, and a mass
generating scale for the gravitationally interacting states around 10^9 GeV if
these states contribute a large fraction to dark matter.
|
[
{
"created": "Thu, 6 Aug 1998 12:33:55 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Dick",
"R.",
""
],
[
"Eschrich",
"N.",
""
],
[
"Gaul",
"M.",
""
]
] |
We point out that the spectrum and interactions of light states of the heterotic string indicate a string scale close to the GUT scale, and a mass generating scale for the gravitationally interacting states around 10^9 GeV if these states contribute a large fraction to dark matter.
|
hep-ph/0003101
| null |
S.M. Barr (Bartol Research Institute)
|
Neutrino Oscillations: Some theoretical ideas
|
LaTex, 13 pages
| null | null |
BA-00_16
|
hep-ph
| null |
Talk given at Orbis Scientiae Conference, Coral Gables, FLA, Dec. 16-19,
1999. Talk surveys some recent three-neutrino models of neutrino masses and
mixings.
|
[
{
"created": "Fri, 10 Mar 2000 16:04:00 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Barr",
"S. M.",
"",
"Bartol Research Institute"
]
] |
Talk given at Orbis Scientiae Conference, Coral Gables, FLA, Dec. 16-19, 1999. Talk surveys some recent three-neutrino models of neutrino masses and mixings.
|
hep-ph/0612183
|
Karol Kolodziej
|
Karol Kolodziej, Szymon Szczypinski
|
Off mass shell effects in associated production of the top quark pair
and Higgs boson at a linear collider
|
11 pages, 4 figures, version published in Acta Physica Polonica B
|
ActaPhys.Polon.B38:2565-2576,2007
| null | null |
hep-ph
| null |
We discuss effects related to the fact that the final state particles of a
reaction e+ e- -> t \bar{t} H are actually produced and they decay off mass
shell. For the intermediate mass Higgs boson, which decays preferably into a
b\bar{b}-quark pair, the reaction will be observed through reactions with 8
fermions in the final state. Such reactions, already in the lowest order of the
standard model, receive contributions typically from a few dozen thousands of
the Feynman diagrams, the vast majority of which constitute background to the
signal of associated production of the top quark pair and Higgs boson. In order
to illustrate pure off mass shell effects we neglect the background
contributions and compare the `signal' cross section with the cross section in
the narrow width approximation for e+ e- -> b u \bar{d} \bar{b} mu- \bar{nu}_mu
b \bar{b}, which is one of possible detection channels of the associated
production of the top quark pair and Higgs boson at a linear collider.
|
[
{
"created": "Thu, 14 Dec 2006 15:36:05 GMT",
"version": "v1"
},
{
"created": "Wed, 22 Aug 2007 15:49:37 GMT",
"version": "v2"
}
] |
2008-11-26
|
[
[
"Kolodziej",
"Karol",
""
],
[
"Szczypinski",
"Szymon",
""
]
] |
We discuss effects related to the fact that the final state particles of a reaction e+ e- -> t \bar{t} H are actually produced and they decay off mass shell. For the intermediate mass Higgs boson, which decays preferably into a b\bar{b}-quark pair, the reaction will be observed through reactions with 8 fermions in the final state. Such reactions, already in the lowest order of the standard model, receive contributions typically from a few dozen thousands of the Feynman diagrams, the vast majority of which constitute background to the signal of associated production of the top quark pair and Higgs boson. In order to illustrate pure off mass shell effects we neglect the background contributions and compare the `signal' cross section with the cross section in the narrow width approximation for e+ e- -> b u \bar{d} \bar{b} mu- \bar{nu}_mu b \bar{b}, which is one of possible detection channels of the associated production of the top quark pair and Higgs boson at a linear collider.
|
hep-ph/0205045
|
National Center for Physics
|
M. Jamil Aslam (Quaid-i-Azam University, Pakistan)
|
Studying Bounds on Lepton Flavor Violating (LFV) Decay Processes
|
M.Phil. thesis, five figures (four figures in one file and one in
another), results are discussed in Chap. 4
| null | null | null |
hep-ph
| null |
This dissertation reviews the Standard Model formalism as well as the Lepton
Flavour Violating (LFV) decay processes which cause its extension, known as the
physics beyond the SM. Firstly, using the experimental bounds on three body LFV
decays, the corresponding bounds on two body LFV decays are reviewed. The
dynamical suppression of three body LFV decays due to momentum dependent
couplings is also reviewed. Secondly, the role of the LFV decays to explain the
LSND excess is discussed in detail, for which the experimental bounds on three
body LFV decays, i.e. \mu -> 3e are used to constraint the coupling
\tilde{g}_{Z_{\mu e}}, which is needed to calculate the anomalous muon decay
\mu -> e\nu_l\bar{\nu}_l. Then comparing the effective coupling of anomalous
muon decay to r>1.6\times 10^{-3} [9809524], it is proved that LFV is not the
correct hypothesis to explain the LSND excess. Finally, LFV decays at loop
order are studied in Seesaw model of neutrino masses [PRL. 86 2502 (2001)]
where the smallness of the Seesaw neutrino mass may be naturally realized with
m_N (mass of right-handed singlet neutrinos) of order 1 TeV. It is shown that
the Higgs mass of a new scalar doublet with lepton number L=-1 needed in the
model has to be larger than 50 TeV to get the branching ratio of \mu -> 3e to
be consistent with the existing bound on \mu -> 3e. This defeats the original
motivation of the model, namely that there is no physics beyond the TeV energy
scale.
|
[
{
"created": "Mon, 6 May 2002 10:39:58 GMT",
"version": "v1"
}
] |
2016-09-06
|
[
[
"Aslam",
"M. Jamil",
"",
"Quaid-i-Azam University, Pakistan"
]
] |
This dissertation reviews the Standard Model formalism as well as the Lepton Flavour Violating (LFV) decay processes which cause its extension, known as the physics beyond the SM. Firstly, using the experimental bounds on three body LFV decays, the corresponding bounds on two body LFV decays are reviewed. The dynamical suppression of three body LFV decays due to momentum dependent couplings is also reviewed. Secondly, the role of the LFV decays to explain the LSND excess is discussed in detail, for which the experimental bounds on three body LFV decays, i.e. \mu -> 3e are used to constraint the coupling \tilde{g}_{Z_{\mu e}}, which is needed to calculate the anomalous muon decay \mu -> e\nu_l\bar{\nu}_l. Then comparing the effective coupling of anomalous muon decay to r>1.6\times 10^{-3} [9809524], it is proved that LFV is not the correct hypothesis to explain the LSND excess. Finally, LFV decays at loop order are studied in Seesaw model of neutrino masses [PRL. 86 2502 (2001)] where the smallness of the Seesaw neutrino mass may be naturally realized with m_N (mass of right-handed singlet neutrinos) of order 1 TeV. It is shown that the Higgs mass of a new scalar doublet with lepton number L=-1 needed in the model has to be larger than 50 TeV to get the branching ratio of \mu -> 3e to be consistent with the existing bound on \mu -> 3e. This defeats the original motivation of the model, namely that there is no physics beyond the TeV energy scale.
|
2201.05397
|
Shunzo Kumano
|
S. Kumano and Qin-Tao Song
|
TMDs for spin-1 hadrons
|
5 pages, LaTeX, 24th International Spin Symposium, October 18-22,
2021, (In person/Online) Matsue, Japan
| null |
10.7566/JPSCP.37.020130
|
KEK-TH-2383, J-PARC-TH-0262
|
hep-ph hep-ex hep-lat nucl-th
|
http://creativecommons.org/licenses/by/4.0/
|
Transverse-momentum-dependent parton distribution functions (TMDs) were
investigated at the twists 3 and 4 for spin-1 hadrons in addition to the
twist-2 ones. They were found by studying all the possible decomposition of a
quark correlation function in a Lorentz-invariant way with the Hermiticity and
parity invariance. The time-reversal invariance was not imposed for the TMDs
due to an active role of gauge links; however, they were used for collinear
parton distribution functions (PDFs) by integrating the TMDs over the
transverse momentum. We found that 30 TMDs exist in the tensor-polarized spin-1
hadron at the twists 3 and 4, whereas there are 10 TMDs at the twist 2. We also
showed that there are 3 collinear PDFs at the twists 3 and 4. The corresponding
TMD fragmentation functions exist sat the twists 2, 3, and 4 simply by changing
function names and variables. Since the time-reversal invariance is valid in
the collinear PDFs, the integrals of time-reversal-odd TMDs over the transverse
momentum should vanish. It leads to the sum rules $ \int d^2 k_T \, h_{1LT} (x,
k_T^{\, 2}) = \int d^2 k_T g_{LT} (x, k_T^{\, 2}) = \int d^2 k_T h_{LL} (x,
k_T^{\, 2}) = \int d^2 k_T h_{3LL}(x, k_T^{\, 2}) =0$ on the time-reversal odd
TMDs at the twists 3 and 4.
|
[
{
"created": "Fri, 14 Jan 2022 11:23:14 GMT",
"version": "v1"
}
] |
2023-01-18
|
[
[
"Kumano",
"S.",
""
],
[
"Song",
"Qin-Tao",
""
]
] |
Transverse-momentum-dependent parton distribution functions (TMDs) were investigated at the twists 3 and 4 for spin-1 hadrons in addition to the twist-2 ones. They were found by studying all the possible decomposition of a quark correlation function in a Lorentz-invariant way with the Hermiticity and parity invariance. The time-reversal invariance was not imposed for the TMDs due to an active role of gauge links; however, they were used for collinear parton distribution functions (PDFs) by integrating the TMDs over the transverse momentum. We found that 30 TMDs exist in the tensor-polarized spin-1 hadron at the twists 3 and 4, whereas there are 10 TMDs at the twist 2. We also showed that there are 3 collinear PDFs at the twists 3 and 4. The corresponding TMD fragmentation functions exist sat the twists 2, 3, and 4 simply by changing function names and variables. Since the time-reversal invariance is valid in the collinear PDFs, the integrals of time-reversal-odd TMDs over the transverse momentum should vanish. It leads to the sum rules $ \int d^2 k_T \, h_{1LT} (x, k_T^{\, 2}) = \int d^2 k_T g_{LT} (x, k_T^{\, 2}) = \int d^2 k_T h_{LL} (x, k_T^{\, 2}) = \int d^2 k_T h_{3LL}(x, k_T^{\, 2}) =0$ on the time-reversal odd TMDs at the twists 3 and 4.
|
2011.09475
|
Wen Yin
|
Takeo Moroi and Wen Yin
|
Light Dark Matter from Inflaton Decay
|
31 pages, 4 figures; version to appear in JHEP
| null |
10.1007/JHEP03(2021)301
| null |
hep-ph astro-ph.CO gr-qc
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We propose a simple mechanism of light dark matter (DM) production from the
decay of the oscillating inflaton condensation. If the reheating temperature
after inflation is higher than the inflaton mass, which is of the same order of
the momentum of the DM at the time of the production, the DM momentum can be
suppressed compared to the temperature of the thermal plasma if the interaction
of the DM is weak enough. Consequently, the DM can be cold enough to avoid the
observational constraints on the warm DM, like the Lyman-$\alpha$ bound even if
the DM mass is small. We study the bosonic and fermionic DM production from the
inflaton decay, taking into account the effect of the stimulated emission and
Pauli blocking, respectively. In both cases, the DM can be cold and abundant
enough to be a viable candidate of the DM. We also apply our mechanism to the
production of isocurvature-problem-free axion DM and Dirac sea DM of
right-handed neutrino consistent the seesaw relation for the active neutrino
masses.
|
[
{
"created": "Wed, 18 Nov 2020 19:00:00 GMT",
"version": "v1"
},
{
"created": "Tue, 30 Mar 2021 10:10:03 GMT",
"version": "v2"
}
] |
2021-04-21
|
[
[
"Moroi",
"Takeo",
""
],
[
"Yin",
"Wen",
""
]
] |
We propose a simple mechanism of light dark matter (DM) production from the decay of the oscillating inflaton condensation. If the reheating temperature after inflation is higher than the inflaton mass, which is of the same order of the momentum of the DM at the time of the production, the DM momentum can be suppressed compared to the temperature of the thermal plasma if the interaction of the DM is weak enough. Consequently, the DM can be cold enough to avoid the observational constraints on the warm DM, like the Lyman-$\alpha$ bound even if the DM mass is small. We study the bosonic and fermionic DM production from the inflaton decay, taking into account the effect of the stimulated emission and Pauli blocking, respectively. In both cases, the DM can be cold and abundant enough to be a viable candidate of the DM. We also apply our mechanism to the production of isocurvature-problem-free axion DM and Dirac sea DM of right-handed neutrino consistent the seesaw relation for the active neutrino masses.
|
1412.3443
|
Timothy Raben
|
Richard Brower, Marko Djuri\'c, Timothy Raben, Chung-I Tan
|
Towards holographic QCD: AdS/CFT, confinement deformation, and DIS at
small-x
|
4 pages, 4 figures, 1 table. Presented at the Rencontres de Moriond
2014: QCD and High Energy Interactions
| null | null | null |
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We investigate the softwall AdS/CFT model. We specifically looked at the
Pomeron, leading Regge contribution to a scattering process and used it to fit
deep inelastic scattering data from the HERA collaboration. We find that the
model fits the data with much more success than the purely conformal case, and
find similar success to previous confinement models.
|
[
{
"created": "Wed, 10 Dec 2014 20:47:29 GMT",
"version": "v1"
}
] |
2014-12-11
|
[
[
"Brower",
"Richard",
""
],
[
"Djurić",
"Marko",
""
],
[
"Raben",
"Timothy",
""
],
[
"Tan",
"Chung-I",
""
]
] |
We investigate the softwall AdS/CFT model. We specifically looked at the Pomeron, leading Regge contribution to a scattering process and used it to fit deep inelastic scattering data from the HERA collaboration. We find that the model fits the data with much more success than the purely conformal case, and find similar success to previous confinement models.
|
2012.04684
|
Thomas Cridge
|
S. Bailey, T. Cridge, L. A. Harland-Lang, A. D. Martin, R.S. Thorne
|
Parton distributions from LHC, HERA, Tevatron and fixed target data:
MSHT20 PDFs
|
140 pages, 96 figures, 16 tables. Published version plus very minor
alterations - version 4
|
The European Physical Journal C volume 81, Article number: 341
(2021)
|
10.1140/epjc/s10052-021-09057-0
|
IPPP/20/58
|
hep-ph hep-ex
|
http://creativecommons.org/licenses/by/4.0/
|
We present the new MSHT20 set of parton distribution functions (PDFs) of the
proton, determined from global analyses of the available hard scattering data.
The PDFs are made available at NNLO, NLO, and LO, and supersede the MMHT14
sets. They are obtained using the same basic framework, but the
parameterisation is now adapted and extended, and there are 32 pairs of
eigenvector PDFs. We also include a large number of new data sets: from the
final HERA combined data on total and heavy flavour structure functions, to
final Tevatron data, and in particular a significant number of new LHC 7 and 8
TeV data sets on vector boson production, inclusive jets and top quark
distributions. We include up to NNLO QCD corrections for all data sets that
play a major role in the fit, and NLO EW corrections where relevant. We find
that these updates have an important impact on the PDFs, and for the first time
the NNLO fit is strongly favoured over the NLO, reflecting the wider range and
in particular increased precision of data included in the fit. There are some
changes to central values and a significant reduction in the uncertainties of
the PDFs in many, though not all, cases. Nonetheless, the PDFs and the
resulting predictions are generally within one standard deviation of the MMHT14
results. The major changes are the $u-d$ valence quark difference at small $x$,
due to the improved parameterisation and new precise data, the $\bar d, \bar u$
difference at small $x$, due to a much improved parameterisation, and the
strange quark PDF due to the effect of LHC $W,Z$ data and inclusion of new NNLO
corrections for dimuon production in neutrino DIS. We discuss the
phenomenological impact of our results, and in general find reduced
uncertainties in predictions for processes such as Higgs, top quark pair and
$W,Z$ production at post LHC Run-II energies.
|
[
{
"created": "Tue, 8 Dec 2020 19:12:34 GMT",
"version": "v1"
},
{
"created": "Sun, 20 Dec 2020 16:39:19 GMT",
"version": "v2"
},
{
"created": "Wed, 28 Jul 2021 09:12:57 GMT",
"version": "v3"
},
{
"created": "Fri, 19 Aug 2022 16:25:33 GMT",
"version": "v4"
}
] |
2022-08-22
|
[
[
"Bailey",
"S.",
""
],
[
"Cridge",
"T.",
""
],
[
"Harland-Lang",
"L. A.",
""
],
[
"Martin",
"A. D.",
""
],
[
"Thorne",
"R. S.",
""
]
] |
We present the new MSHT20 set of parton distribution functions (PDFs) of the proton, determined from global analyses of the available hard scattering data. The PDFs are made available at NNLO, NLO, and LO, and supersede the MMHT14 sets. They are obtained using the same basic framework, but the parameterisation is now adapted and extended, and there are 32 pairs of eigenvector PDFs. We also include a large number of new data sets: from the final HERA combined data on total and heavy flavour structure functions, to final Tevatron data, and in particular a significant number of new LHC 7 and 8 TeV data sets on vector boson production, inclusive jets and top quark distributions. We include up to NNLO QCD corrections for all data sets that play a major role in the fit, and NLO EW corrections where relevant. We find that these updates have an important impact on the PDFs, and for the first time the NNLO fit is strongly favoured over the NLO, reflecting the wider range and in particular increased precision of data included in the fit. There are some changes to central values and a significant reduction in the uncertainties of the PDFs in many, though not all, cases. Nonetheless, the PDFs and the resulting predictions are generally within one standard deviation of the MMHT14 results. The major changes are the $u-d$ valence quark difference at small $x$, due to the improved parameterisation and new precise data, the $\bar d, \bar u$ difference at small $x$, due to a much improved parameterisation, and the strange quark PDF due to the effect of LHC $W,Z$ data and inclusion of new NNLO corrections for dimuon production in neutrino DIS. We discuss the phenomenological impact of our results, and in general find reduced uncertainties in predictions for processes such as Higgs, top quark pair and $W,Z$ production at post LHC Run-II energies.
|
1905.07708
|
Haiqing Zhou
|
Hui-Yun Cao, Hai-Qing Zhou
|
Mass shifts of $^3P_J$ heavy quarkonia due to the effect of two-gluon
annihilation
| null |
Phys. Rev. D 100, 094004 (2019)
|
10.1103/PhysRevD.100.094004
| null |
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In this work, we calculate the nonrelativistic asymptotic behavior of the
amplitudes of $q\overline{q}\rightarrow 2g \rightarrow q\overline{q}$ in the
leading order of $\alpha_s$ (LO-$\alpha_s$) with $q\overline{q}$ in the $^3P_J$
channels. In the practical calculation we take the momenta of quarks and
antiquarks on-shell and expand the amplitudes on the three-momentum of the
quarks and antiquarks to order 6 and get three nonzero terms. The imaginary
parts of the first term and the second term are the old. The real parts of the
results have IR divergence. When applying the results to the heavy quarkonia,
the corresponding amplitude of $q\overline{q}\rightarrow1g\rightarrow
q\overline{q}$ with $q\overline{q}$ in the color octet $^3S_1$ channel is
considered to absorb the IR divergence in a unitary way in the leading order of
$v$ (LO-$v$). The finial results can be used to estimate the mass shifts of the
$^3P_J$ heavy quarkonia due to the effect of two-gluon annihilation. The
numerical estimation shows that the contributions to the mass shifts of
$\chi_{c0,c1,c2}$ are about $1.23\sim1.58$ MeV, $1.57\sim1.86$ MeV and
$5.92\sim5.45$ MeV when taking $\alpha_s\approx 0.25\sim0.35$.
|
[
{
"created": "Sun, 19 May 2019 08:31:30 GMT",
"version": "v1"
}
] |
2019-11-13
|
[
[
"Cao",
"Hui-Yun",
""
],
[
"Zhou",
"Hai-Qing",
""
]
] |
In this work, we calculate the nonrelativistic asymptotic behavior of the amplitudes of $q\overline{q}\rightarrow 2g \rightarrow q\overline{q}$ in the leading order of $\alpha_s$ (LO-$\alpha_s$) with $q\overline{q}$ in the $^3P_J$ channels. In the practical calculation we take the momenta of quarks and antiquarks on-shell and expand the amplitudes on the three-momentum of the quarks and antiquarks to order 6 and get three nonzero terms. The imaginary parts of the first term and the second term are the old. The real parts of the results have IR divergence. When applying the results to the heavy quarkonia, the corresponding amplitude of $q\overline{q}\rightarrow1g\rightarrow q\overline{q}$ with $q\overline{q}$ in the color octet $^3S_1$ channel is considered to absorb the IR divergence in a unitary way in the leading order of $v$ (LO-$v$). The finial results can be used to estimate the mass shifts of the $^3P_J$ heavy quarkonia due to the effect of two-gluon annihilation. The numerical estimation shows that the contributions to the mass shifts of $\chi_{c0,c1,c2}$ are about $1.23\sim1.58$ MeV, $1.57\sim1.86$ MeV and $5.92\sim5.45$ MeV when taking $\alpha_s\approx 0.25\sim0.35$.
|
hep-ph/9703273
|
Leonid Burakovsky
|
L. Burakovsky
|
Towards resolution of the scalar meson nonet enigma
|
16 pages, LaTeX
|
Found.Phys. 27 (1997) 315-330
|
10.1007/BF02550457
| null |
hep-ph
| null |
By the application of a linear mass spectrum to a composite system of both
the pseudoscalar and scalar meson nonets, we find three mass relations for the
masses of the scalar states which suggest the $q\bar{q}$ assignment for the
scalar meson nonet: $a_0(1320),$ $K_0^\ast (1430),$ $f_0(1500),$ $f_0'(980).$
|
[
{
"created": "Sat, 8 Mar 1997 00:11:35 GMT",
"version": "v1"
}
] |
2009-10-30
|
[
[
"Burakovsky",
"L.",
""
]
] |
By the application of a linear mass spectrum to a composite system of both the pseudoscalar and scalar meson nonets, we find three mass relations for the masses of the scalar states which suggest the $q\bar{q}$ assignment for the scalar meson nonet: $a_0(1320),$ $K_0^\ast (1430),$ $f_0(1500),$ $f_0'(980).$
|
1908.00446
|
Cristian Pisano
|
Umberto D'Alesio, Francesco Murgia, Cristian Pisano, Pieter Taels
|
Azimuthal asymmetries in semi-inclusive $J/\psi\,+\,\mathrm{jet}$
production at an EIC
|
15 pages, 8 figures; v2: conclusions expanded, references added,
matches published version
|
Phys. Rev. D 100, 094016 (2019)
|
10.1103/PhysRevD.100.094016
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider transverse momentum dependent gluon distributions inside both
unpolarized and transversely polarized protons and show how they can be probed
by looking at azimuthal modulations in $e \, p \to e \, J/\psi \, \mathrm{jet}
\, X$. We find that the contribution due to quark induced subprocesses is
always suppressed in the considered kinematic regions, accessible in principle
at a future Electron-Ion Collider. Our model-independent estimates of the
maximal values of these asymmetries allowed by positivity bounds suggest the
feasibility of their measurement. In addition, by adopting the
McLerran-Venugopalan model for the unpolarized and linearly polarized gluon
densities, we study the behavior of the $\cos2\phi$ asymmetries in the
small-$x$ limit.
|
[
{
"created": "Thu, 1 Aug 2019 15:00:16 GMT",
"version": "v1"
},
{
"created": "Sun, 8 Dec 2019 22:15:13 GMT",
"version": "v2"
}
] |
2019-12-10
|
[
[
"D'Alesio",
"Umberto",
""
],
[
"Murgia",
"Francesco",
""
],
[
"Pisano",
"Cristian",
""
],
[
"Taels",
"Pieter",
""
]
] |
We consider transverse momentum dependent gluon distributions inside both unpolarized and transversely polarized protons and show how they can be probed by looking at azimuthal modulations in $e \, p \to e \, J/\psi \, \mathrm{jet} \, X$. We find that the contribution due to quark induced subprocesses is always suppressed in the considered kinematic regions, accessible in principle at a future Electron-Ion Collider. Our model-independent estimates of the maximal values of these asymmetries allowed by positivity bounds suggest the feasibility of their measurement. In addition, by adopting the McLerran-Venugopalan model for the unpolarized and linearly polarized gluon densities, we study the behavior of the $\cos2\phi$ asymmetries in the small-$x$ limit.
|
hep-ph/0409346
|
Yili Wang
|
Xiao-Gang He, G. Valencia and Yili Wang
|
Lepton flavor violating tau and B decays and heavy neutrinos
|
24 pages,8 figures. Discussion and comparison with the literature
added. CLEO results updated. Conclusions unchanged
|
Phys.Rev. D70 (2004) 113011
|
10.1103/PhysRevD.70.113011
| null |
hep-ph
| null |
We study lepton flavor violating (LFV) tau and B decays in models with heavy
neutrinos to constrain the mixing matrix parameters U_{tau N}. We find that the
best current constraints when the heavy neutrinos are purely left-handed come
from LFV radiative tau decay modes. To obtain competitive constraints in LFV B
decay it is necessary to probe b -> X_{s} tau^{\pm} e^{\mp} at the 10^{-7}
level. When the heavy neutrinos have both left and right-handed couplings, the
mixing parameters can be constrained by studying LFV B decay modes and LFV tau
decay into three charged leptons. We find that the branching ratios B(tau^{\pm}
-> l_1^{\pm} l_2^{\pm} l_3^{\mp}), B(B_{s} -> tau^{\pm} e^{\mp}) and B(b ->
X_{s} l_1^{\pm} l_2^{\mp}) need to be probed at the 10^{-8} level in order to
constrain the mixing parameters beyond what is known from unitarity.
|
[
{
"created": "Wed, 29 Sep 2004 16:01:57 GMT",
"version": "v1"
},
{
"created": "Mon, 6 Dec 2004 19:24:45 GMT",
"version": "v2"
}
] |
2009-11-10
|
[
[
"He",
"Xiao-Gang",
""
],
[
"Valencia",
"G.",
""
],
[
"Wang",
"Yili",
""
]
] |
We study lepton flavor violating (LFV) tau and B decays in models with heavy neutrinos to constrain the mixing matrix parameters U_{tau N}. We find that the best current constraints when the heavy neutrinos are purely left-handed come from LFV radiative tau decay modes. To obtain competitive constraints in LFV B decay it is necessary to probe b -> X_{s} tau^{\pm} e^{\mp} at the 10^{-7} level. When the heavy neutrinos have both left and right-handed couplings, the mixing parameters can be constrained by studying LFV B decay modes and LFV tau decay into three charged leptons. We find that the branching ratios B(tau^{\pm} -> l_1^{\pm} l_2^{\pm} l_3^{\mp}), B(B_{s} -> tau^{\pm} e^{\mp}) and B(b -> X_{s} l_1^{\pm} l_2^{\mp}) need to be probed at the 10^{-8} level in order to constrain the mixing parameters beyond what is known from unitarity.
|
hep-ph/0011194
|
Genis Musulmanbekov
|
G. Musulmanbekov (JINR)
|
Quark Correlations Inside Hadrons And Single Diffraction
|
12 pages, 7 Postscript figures
| null | null | null |
hep-ph
| null |
Hadron structure is considered in the frame of Strongly Correlated Quark
Model (SCQM). It is shown that quark correlations result in fluctuations of
hadronic matter distributions and single diffractive dissociation processes in
hadronic collisions, hard or soft, are manifestation of these fluctuations
inside colliding hadrons.
|
[
{
"created": "Wed, 15 Nov 2000 19:05:51 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Musulmanbekov",
"G.",
"",
"JINR"
]
] |
Hadron structure is considered in the frame of Strongly Correlated Quark Model (SCQM). It is shown that quark correlations result in fluctuations of hadronic matter distributions and single diffractive dissociation processes in hadronic collisions, hard or soft, are manifestation of these fluctuations inside colliding hadrons.
|
2211.04397
|
Di Zhang
|
Di Zhang, Shun Zhou
|
One-loop Matching for the Seesaw Model
|
4 pages, 1 table; contribution to the Proceedings of the 41st
International Conference on High Energy Physics (ICHEP2022)
| null | null | null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In this talk, we present the results of the complete one-loop matching of the
seesaw model onto its low-energy effective theory by integrating out three
right-handed neutrinos at the one-loop level. We find that there are 31
independent dimension-6 (dim-6) operators (barring flavor structures and
Hermitian conjugates) in the Warsaw basis, and the standard-model couplings and
the Wilson coefficient of the Weinberg operator acquire threshold corrections
at the one-loop level. The complete Lagrangian up to dim-6 at the one-loop
level is derived, which is indispensable for consistent explorations of the
impact of heavy right-handed neutrinos at low energies.
|
[
{
"created": "Tue, 8 Nov 2022 17:40:27 GMT",
"version": "v1"
}
] |
2022-11-09
|
[
[
"Zhang",
"Di",
""
],
[
"Zhou",
"Shun",
""
]
] |
In this talk, we present the results of the complete one-loop matching of the seesaw model onto its low-energy effective theory by integrating out three right-handed neutrinos at the one-loop level. We find that there are 31 independent dimension-6 (dim-6) operators (barring flavor structures and Hermitian conjugates) in the Warsaw basis, and the standard-model couplings and the Wilson coefficient of the Weinberg operator acquire threshold corrections at the one-loop level. The complete Lagrangian up to dim-6 at the one-loop level is derived, which is indispensable for consistent explorations of the impact of heavy right-handed neutrinos at low energies.
|
hep-ph/0611136
|
Wei Qi
|
Wei Qi and Jian-Xiong Wang
|
FDCSUSYDecay: A MSSM Decay package
|
19 pages, 2 figures; misprints corrected
|
Comput.Phys.Commun.177:378-390,2007
|
10.1016/j.cpc.2006.12.007
| null |
hep-ph
| null |
FDCSUSYDecay is a FORTRAN program package generated by FDC (Feynman Diagram
Calculation) system fully automatically. It is dedicated to calculate at
tree-level all the possible 2-body decays of SUSY and Higgs particles in the
Minimal Supersymmetric extension of the Standard Model (MSSM). The format of
its output files complies with SUSY Les Houches Accord and can be easily
imported by other packages.
|
[
{
"created": "Fri, 10 Nov 2006 07:42:45 GMT",
"version": "v1"
},
{
"created": "Fri, 1 Dec 2006 12:17:50 GMT",
"version": "v2"
}
] |
2008-11-26
|
[
[
"Qi",
"Wei",
""
],
[
"Wang",
"Jian-Xiong",
""
]
] |
FDCSUSYDecay is a FORTRAN program package generated by FDC (Feynman Diagram Calculation) system fully automatically. It is dedicated to calculate at tree-level all the possible 2-body decays of SUSY and Higgs particles in the Minimal Supersymmetric extension of the Standard Model (MSSM). The format of its output files complies with SUSY Les Houches Accord and can be easily imported by other packages.
|
2004.10052
|
Mar\'ia Florencia Izzo Villafa\~ne
|
D. G\'omez Dumm, M.F. Izzo Villafa\~ne, N.N. Scoccola
|
Properties of magnetized neutral pions at zero and finite temperature in
nonlocal chiral quark models
|
30 pages, 4 figures. arXiv admin note: text overlap with
arXiv:1710.08950
|
Phys. Rev. D 101, 116018 (2020)
|
10.1103/PhysRevD.101.116018
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The behavior of $\pi^0$ meson properties in the presence of a uniform
external magnetic field is studied in the context of a nonlocal extension of
the Polyakov-Nambu-Jona-Lasinio model. The analysis includes the $\pi^0$ mass,
the effective $\pi^0$-quark coupling and the pion-to-vacuum hadronic form
factors, both at zero and finite temperature. Numerical results are compared
with previous calculations carried out within the local NJL model, when
available. The validity of chiral relations and the features of deconfinement
and chiral symmetry restoration transitions are discussed.
|
[
{
"created": "Sat, 18 Apr 2020 18:00:34 GMT",
"version": "v1"
}
] |
2020-07-08
|
[
[
"Dumm",
"D. Gómez",
""
],
[
"Villafañe",
"M. F. Izzo",
""
],
[
"Scoccola",
"N. N.",
""
]
] |
The behavior of $\pi^0$ meson properties in the presence of a uniform external magnetic field is studied in the context of a nonlocal extension of the Polyakov-Nambu-Jona-Lasinio model. The analysis includes the $\pi^0$ mass, the effective $\pi^0$-quark coupling and the pion-to-vacuum hadronic form factors, both at zero and finite temperature. Numerical results are compared with previous calculations carried out within the local NJL model, when available. The validity of chiral relations and the features of deconfinement and chiral symmetry restoration transitions are discussed.
|
1601.03508
|
Hamzeh Khanpour
|
Hamzeh Khanpour, Abolfazl Mirjalili and S. Atashbar Tehrani
|
Analytic derivation of the next-to-leading order proton structure
function $F_2^p(x, Q^2)$ based on the Laplace transformation
|
25 Pages, 11 Figures and 3 Tables
|
Phys. Rev. C 95, 035201 (2017)
|
10.1103/PhysRevC.95.035201
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
An analytical solution based on the Laplace transformation technique for the
DGLAP evolution equations is presented at next-to-leading order accuracy in
perturbative QCD. This technique is also applied to extract the analytical
solution for the proton structure function, $F_2^p(x, Q^2)$, in the Laplace
$s$-space. We present the results for the separate parton distributions for all
parton species, including valence quark densities, the anti-quark and strange
sea parton distribution functions (PDFs), and the gluon distribution. We
successfully compare the obtained parton distribution functions and the proton
structure function with the results from {\tt GJR08} and {\tt KKT12}
parametrization models as well as the $x$-space results using {\tt QCDnum}
code. Our calculations show a very good agreement with the available
theoretical models as well as the deep inelastic scattering (DIS) experimental
data throughout the small and large values of $x$. The use of our analytical
solution to extract the parton densities and the proton structure function is
discussed in detail to justify the analysis method considering the accuracy and
speed of calculations. Overall, the accuracy we obtain from the analytical
solution using the inverse Laplace transform technique is found to be better
than 1 part in 10$^{4}$ to 10$^{5}$. We also present a detailed QCD analysis of
non-singlet structure functions using all available DIS data to perform global
QCD fits. In this regard we employ the Jacobi polynomial approach to convert
the results from Laplace $s$ space to Bjorken $x$ space. The extracted valence
quark densities are also presented and compared to the {\tt JR14}, {\tt
MMHT14}, {\tt NNPDF} and {\tt CJ15} PDFs sets. We evaluate the numerical
effects of target mass corrections (TMCs) and higher twist (HT) terms on
various structure functions, and compare fits to data with and without these
corrections.
|
[
{
"created": "Thu, 14 Jan 2016 07:27:27 GMT",
"version": "v1"
},
{
"created": "Fri, 23 Sep 2016 11:22:55 GMT",
"version": "v2"
},
{
"created": "Tue, 7 Mar 2017 19:26:24 GMT",
"version": "v3"
}
] |
2017-03-09
|
[
[
"Khanpour",
"Hamzeh",
""
],
[
"Mirjalili",
"Abolfazl",
""
],
[
"Tehrani",
"S. Atashbar",
""
]
] |
An analytical solution based on the Laplace transformation technique for the DGLAP evolution equations is presented at next-to-leading order accuracy in perturbative QCD. This technique is also applied to extract the analytical solution for the proton structure function, $F_2^p(x, Q^2)$, in the Laplace $s$-space. We present the results for the separate parton distributions for all parton species, including valence quark densities, the anti-quark and strange sea parton distribution functions (PDFs), and the gluon distribution. We successfully compare the obtained parton distribution functions and the proton structure function with the results from {\tt GJR08} and {\tt KKT12} parametrization models as well as the $x$-space results using {\tt QCDnum} code. Our calculations show a very good agreement with the available theoretical models as well as the deep inelastic scattering (DIS) experimental data throughout the small and large values of $x$. The use of our analytical solution to extract the parton densities and the proton structure function is discussed in detail to justify the analysis method considering the accuracy and speed of calculations. Overall, the accuracy we obtain from the analytical solution using the inverse Laplace transform technique is found to be better than 1 part in 10$^{4}$ to 10$^{5}$. We also present a detailed QCD analysis of non-singlet structure functions using all available DIS data to perform global QCD fits. In this regard we employ the Jacobi polynomial approach to convert the results from Laplace $s$ space to Bjorken $x$ space. The extracted valence quark densities are also presented and compared to the {\tt JR14}, {\tt MMHT14}, {\tt NNPDF} and {\tt CJ15} PDFs sets. We evaluate the numerical effects of target mass corrections (TMCs) and higher twist (HT) terms on various structure functions, and compare fits to data with and without these corrections.
|
hep-ph/9301259
|
Wai-Yee
|
Darwin Chang, Wai-Yee Keung, and Ivan Phillips
|
CP Violation in top pair production at an e^+e^- collider
|
16 pages, including postscript graphs not posted before
|
Nucl.Phys.B408:286-298,1993; ERRATUM-ibid.B429:255,1994
|
10.1016/0550-3213(93)90536-X
|
CERN-TH.6658/92
|
hep-ph
| null |
We investigate possible CP violating effects in $e^+e^-$ annihilation into
top quark pairs. One of the interesting observable effects is the difference in
production rates between the two CP conjugate polarized states $t_L\bar t_L$
and $t_R\bar t_R$. The result is an asymmetry in the energy spectra of the
lepton and the anti-lepton from the heavy quark decays. Another CP-odd
observable is the up-down asymmetry of the leptons with respect to the reaction
plane. These two asymmetries measure complementarily the absorptive and
dispersive form factors of the electric dipole moment. Finally, as an
illustration, we calculate the size of the CP violating form factors in a model
where the CP nonconservation originates from the Yukawa couplings of a neutral
Higgs boson.
|
[
{
"created": "Fri, 22 Jan 1993 09:25:39 GMT",
"version": "v1"
},
{
"created": "Mon, 25 Jan 1993 12:14:46 GMT",
"version": "v2"
},
{
"created": "Sun, 14 Jun 1998 11:38:54 GMT",
"version": "v3"
}
] |
2009-09-01
|
[
[
"Chang",
"Darwin",
""
],
[
"Keung",
"Wai-Yee",
""
],
[
"Phillips",
"Ivan",
""
]
] |
We investigate possible CP violating effects in $e^+e^-$ annihilation into top quark pairs. One of the interesting observable effects is the difference in production rates between the two CP conjugate polarized states $t_L\bar t_L$ and $t_R\bar t_R$. The result is an asymmetry in the energy spectra of the lepton and the anti-lepton from the heavy quark decays. Another CP-odd observable is the up-down asymmetry of the leptons with respect to the reaction plane. These two asymmetries measure complementarily the absorptive and dispersive form factors of the electric dipole moment. Finally, as an illustration, we calculate the size of the CP violating form factors in a model where the CP nonconservation originates from the Yukawa couplings of a neutral Higgs boson.
|
2007.07376
|
Kyrill Bugaev
|
O. V. Vitiuk, K. A. Bugaev, E. S. Zherebtsova, D. B. Blaschke, L. V.
Bravina, E. E. Zabrodin and G. M. Zinovjev
|
Resolution of hyper-triton chemical freeze-out puzzle in high energy
nuclear collisions
|
12 pages, 5 figures and 4 tables
| null |
10.1140/epja/s10050-021-00370-6
| null |
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The recently developed hadron resonance gas model with multicomponent
hard-core repulsion is used to address and resolve the long standing problem to
describe the light nuclear cluster multiplicities including the hyper-triton
measured by the STAR Collaboration, known as the hyper-triton chemical
freeze-out puzzle. An unprecedentedly accurate description is obtained for the
hadronic and other light nuclear cluster data measured by STAR at the collision
energy $\sqrt{s_{NN}} =200$ GeV and by ALICE at $\sqrt{s_{NN}} =2.76$ TeV. This
success is achieved by applying the new strategy of analyzing the light nuclear
cluster data and by using the value for the hard-core radius of the
(anti-)$\Lambda$ hyperons found in earlier work. One of the most striking
results of the present work is that for the most probable scenario of chemical
freeze-out for the STAR energy the obtained parameters allow to simultaneously
reproduce the values of the experimental ratios $S_3$ and $\bar{S}_3$ which
were not included in the fit.
|
[
{
"created": "Tue, 14 Jul 2020 22:05:46 GMT",
"version": "v1"
}
] |
2021-03-17
|
[
[
"Vitiuk",
"O. V.",
""
],
[
"Bugaev",
"K. A.",
""
],
[
"Zherebtsova",
"E. S.",
""
],
[
"Blaschke",
"D. B.",
""
],
[
"Bravina",
"L. V.",
""
],
[
"Zabrodin",
"E. E.",
""
],
[
"Zinovjev",
"G. M.",
""
]
] |
The recently developed hadron resonance gas model with multicomponent hard-core repulsion is used to address and resolve the long standing problem to describe the light nuclear cluster multiplicities including the hyper-triton measured by the STAR Collaboration, known as the hyper-triton chemical freeze-out puzzle. An unprecedentedly accurate description is obtained for the hadronic and other light nuclear cluster data measured by STAR at the collision energy $\sqrt{s_{NN}} =200$ GeV and by ALICE at $\sqrt{s_{NN}} =2.76$ TeV. This success is achieved by applying the new strategy of analyzing the light nuclear cluster data and by using the value for the hard-core radius of the (anti-)$\Lambda$ hyperons found in earlier work. One of the most striking results of the present work is that for the most probable scenario of chemical freeze-out for the STAR energy the obtained parameters allow to simultaneously reproduce the values of the experimental ratios $S_3$ and $\bar{S}_3$ which were not included in the fit.
|
1901.10504
|
Mike Berger
|
Micheal S. Berger, Maria Dawid
|
A Froggatt-Nielsen flavor model for neutrino physics
|
7 pages, no figures
| null |
10.1142/S0217751X19501021
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Superheavy neutrinos can, via the seesaw model, provide a mechanism for
lepton number violation. If they are combined with flavor violation as
characterized by the Froggatt-Nielsen mechanism, then the phenomenology for the
neutrinos in oscillation experiments, neutrinoless double beta decay, and other
experiments can be described by a relatively few number of parameters. We
describe the low-energy neutrino mass matrix and show that the results are
consistent with currently available data.
|
[
{
"created": "Tue, 29 Jan 2019 19:27:44 GMT",
"version": "v1"
}
] |
2019-07-24
|
[
[
"Berger",
"Micheal S.",
""
],
[
"Dawid",
"Maria",
""
]
] |
Superheavy neutrinos can, via the seesaw model, provide a mechanism for lepton number violation. If they are combined with flavor violation as characterized by the Froggatt-Nielsen mechanism, then the phenomenology for the neutrinos in oscillation experiments, neutrinoless double beta decay, and other experiments can be described by a relatively few number of parameters. We describe the low-energy neutrino mass matrix and show that the results are consistent with currently available data.
|
hep-ph/9606379
|
Arnd Brandenburg
|
W. Bernreuther, A. Brandenburg (RWTH Aachen), P. Haberl, O. Nachtmann
(Univ. Heidelberg)
|
Chiral-invariant CP-violating Effective Interactions in Z Decays to
three Jets
|
14 pages, LaTeX with 4 postscript figures, epsf macro included
|
Phys.Lett. B387 (1996) 155-161
|
10.1016/0370-2693(96)00988-4
|
PITHA 96/19, HD-THEP-96-20
|
hep-ph
| null |
Tests of CP violation by appropriate momentum correlations in $Z\to 3$ jets
and in particular in $Z\to b\bar bX$ probe CP-violating effective couplings --
that manifest themselves as form factors -- which conserve the quark chirality
and quark flavour. By giving two examples we show that such couplings can be
induced at one-loop order in extensions of the Standard Model with CP violation
beyond the Kobayashi-Maskawa phase. In one of the models we compute the
chirality-conserving part of the CP-violating $Zb{\bar b}$-gluon amplitude for
massless $b$ quarks, determine the resulting effective dimension $d=6$
couplings in the local limit, and discuss the possible size of the effects.
Finally we show that in models with excited quarks the chiral-invariant
CP-violating effective interactions could be quite large if appropriate
couplings are of a size characteristic of a strong interaction
|
[
{
"created": "Wed, 19 Jun 1996 15:13:43 GMT",
"version": "v1"
}
] |
2009-10-28
|
[
[
"Bernreuther",
"W.",
"",
"RWTH Aachen"
],
[
"Brandenburg",
"A.",
"",
"RWTH Aachen"
],
[
"Haberl",
"P.",
"",
"Univ. Heidelberg"
],
[
"Nachtmann",
"O.",
"",
"Univ. Heidelberg"
]
] |
Tests of CP violation by appropriate momentum correlations in $Z\to 3$ jets and in particular in $Z\to b\bar bX$ probe CP-violating effective couplings -- that manifest themselves as form factors -- which conserve the quark chirality and quark flavour. By giving two examples we show that such couplings can be induced at one-loop order in extensions of the Standard Model with CP violation beyond the Kobayashi-Maskawa phase. In one of the models we compute the chirality-conserving part of the CP-violating $Zb{\bar b}$-gluon amplitude for massless $b$ quarks, determine the resulting effective dimension $d=6$ couplings in the local limit, and discuss the possible size of the effects. Finally we show that in models with excited quarks the chiral-invariant CP-violating effective interactions could be quite large if appropriate couplings are of a size characteristic of a strong interaction
|
hep-ph/9602220
|
Mikhail Dubinin
|
E.Boos, M.Dubinin, L.Dudko (Institute of Nuclear Physics, Moscow State
University, Russia)
|
Higgs boson production under the resonance threshold at LEP II
|
19 pages, including 1 figure in LaTeX, 8 postscript figures
|
Int.J.Mod.Phys. A11 (1996) 5015-5026
|
10.1142/S0217751X96002315
|
INP MSU 96-2/409, SNUTP 96-004
|
hep-ph
| null |
We consider the possibility of Higgs boson detection at LEP II under the
resonance threshold ($\sqrt{s}<m_H+m_Z$) in the framework of complete tree
level approach to the calculation of the $e^+ e^- \rightarrow \nu \bar \nu b
\bar b$ amplitude, simulating b-quark fragmentation to hadrons and taking into
account typical detector properties. At the energy below the $2m_Z$ threshold
$\sqrt{s}=$ 175 GeV Higgs boson production under the $m_H+m_Z$ threshold is
practically background free.
|
[
{
"created": "Sat, 3 Feb 1996 05:32:21 GMT",
"version": "v1"
}
] |
2015-06-25
|
[
[
"Boos",
"E.",
"",
"Institute of Nuclear Physics, Moscow State\n University, Russia"
],
[
"Dubinin",
"M.",
"",
"Institute of Nuclear Physics, Moscow State\n University, Russia"
],
[
"Dudko",
"L.",
"",
"Institute of Nuclear Physics, Moscow State\n University, Russia"
]
] |
We consider the possibility of Higgs boson detection at LEP II under the resonance threshold ($\sqrt{s}<m_H+m_Z$) in the framework of complete tree level approach to the calculation of the $e^+ e^- \rightarrow \nu \bar \nu b \bar b$ amplitude, simulating b-quark fragmentation to hadrons and taking into account typical detector properties. At the energy below the $2m_Z$ threshold $\sqrt{s}=$ 175 GeV Higgs boson production under the $m_H+m_Z$ threshold is practically background free.
|
hep-ph/0610058
|
Doreen Wackeroth
|
Doreen Wackeroth
|
Electroweak Physics: Theoretical Overview
|
6 pages, 6 figures, talk presented at the Hadron Collider Physics
Symposium 2006 (HCP 2006) at Duke University, Durham, North Carolina. One
reference added
| null | null | null |
hep-ph
| null |
I give an overview of the theory status of predictions for single W and Z
boson production at hadron colliders. I briefly report on work in progress for
improvements necessary to match the anticipated high precision of electroweak
measurements, such as the W mass and width, at the Fermilab Tevatron p anti-p
and the CERN LHC pp colliders.
|
[
{
"created": "Wed, 4 Oct 2006 22:19:48 GMT",
"version": "v1"
},
{
"created": "Thu, 12 Oct 2006 19:58:30 GMT",
"version": "v2"
},
{
"created": "Thu, 12 Oct 2006 20:03:08 GMT",
"version": "v3"
}
] |
2007-05-23
|
[
[
"Wackeroth",
"Doreen",
""
]
] |
I give an overview of the theory status of predictions for single W and Z boson production at hadron colliders. I briefly report on work in progress for improvements necessary to match the anticipated high precision of electroweak measurements, such as the W mass and width, at the Fermilab Tevatron p anti-p and the CERN LHC pp colliders.
|
0801.1286
|
Vinod Chandra
|
Vinod Chandra, Akhilesh Ranjan and V. Ravishankar
|
Hot QCD equations of state and response functions for quark-gluon plasma
|
11 pages, 10 figures, revtex4; 2 tables; several references added,
Introduction revised; section.V revised; Fig.3 replaced
| null | null | null |
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study the response functions (chromo-electric susceptibilities) of
quark-gluon plasma as a function of temperature in the presence of
interactions. We consider two equations of state for hot QCD. The first one is
fully perturbative, of $O(g^5)$ EOS and, and the second one which is
$O[g^6\ln(1/g)+\delta]$, incorporates some non-perturbative effects. Following
a recent work (Physical Review {\bf C 76}, 054909(2007)), the interaction
effects contained in the EOS are encapsulated in terms of effective chemical
potentials($\tilde\mu$) in the equilibrium distribution functions for the
partons.By using them in another recent formulation of the response
functions({\tt arXiv:0707.3697}), we determine explicitly the chromo-electric
susceptibilities for QCD plasma. We find that it shows large deviations from
the ideal behavior. We further study the modification in the heavy quark
potential due to the medium effects. In particular, we determine the
temperature dependence of the screening lengths by fixing the effective
coupling constant $Q$ which appears in the transport equation by comparing the
screening in the present formalism with exact lattice QCD results. Finally, we
study the dissociation phenomena of heavy quarkonium states such as $c\bar{c}$
and $b\bar{b}$, and determine the dissociation temperatures. Our results are in
good agreement with recent lattice results.
|
[
{
"created": "Tue, 8 Jan 2008 17:27:36 GMT",
"version": "v1"
},
{
"created": "Wed, 20 Feb 2008 12:12:06 GMT",
"version": "v2"
},
{
"created": "Tue, 1 Jul 2008 05:58:15 GMT",
"version": "v3"
}
] |
2008-07-01
|
[
[
"Chandra",
"Vinod",
""
],
[
"Ranjan",
"Akhilesh",
""
],
[
"Ravishankar",
"V.",
""
]
] |
We study the response functions (chromo-electric susceptibilities) of quark-gluon plasma as a function of temperature in the presence of interactions. We consider two equations of state for hot QCD. The first one is fully perturbative, of $O(g^5)$ EOS and, and the second one which is $O[g^6\ln(1/g)+\delta]$, incorporates some non-perturbative effects. Following a recent work (Physical Review {\bf C 76}, 054909(2007)), the interaction effects contained in the EOS are encapsulated in terms of effective chemical potentials($\tilde\mu$) in the equilibrium distribution functions for the partons.By using them in another recent formulation of the response functions({\tt arXiv:0707.3697}), we determine explicitly the chromo-electric susceptibilities for QCD plasma. We find that it shows large deviations from the ideal behavior. We further study the modification in the heavy quark potential due to the medium effects. In particular, we determine the temperature dependence of the screening lengths by fixing the effective coupling constant $Q$ which appears in the transport equation by comparing the screening in the present formalism with exact lattice QCD results. Finally, we study the dissociation phenomena of heavy quarkonium states such as $c\bar{c}$ and $b\bar{b}$, and determine the dissociation temperatures. Our results are in good agreement with recent lattice results.
|
1608.02771
|
Baishali Saikia
|
D K Choudhury, Baishali Saikia and K Kalita
|
Momentum Fractions carried by quarks and gluons in models of proton
structure functions at small $x$
|
23 pages, 9 figures and 5 tables
| null |
10.1142/S0217751X1750107X
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The paper reports analysis of momentum fractions carried by quarks and gluons
in models of Proton structure functions at small $x$. First, we analyze the
model proposed by Lastovicka based on self-similarity sometime back. We then
make a similar analysis for a second model based on the same notion which is
also free from singularity in $x$ : $0<x<1$. The predictions of both the models
are then compared with a recent QCD based Froissart bound compatible model of
proton structure function at small $x$, suggested by Block, Durand, Ha and
McKay. The results are then compared with the corresponding study in
perturbative and Lattice QCD.
|
[
{
"created": "Tue, 9 Aug 2016 11:53:22 GMT",
"version": "v1"
}
] |
2017-08-02
|
[
[
"Choudhury",
"D K",
""
],
[
"Saikia",
"Baishali",
""
],
[
"Kalita",
"K",
""
]
] |
The paper reports analysis of momentum fractions carried by quarks and gluons in models of Proton structure functions at small $x$. First, we analyze the model proposed by Lastovicka based on self-similarity sometime back. We then make a similar analysis for a second model based on the same notion which is also free from singularity in $x$ : $0<x<1$. The predictions of both the models are then compared with a recent QCD based Froissart bound compatible model of proton structure function at small $x$, suggested by Block, Durand, Ha and McKay. The results are then compared with the corresponding study in perturbative and Lattice QCD.
|
hep-ph/0006322
|
Kyoungkeun Jeong
|
K. K. Jeong, C. S. Kim, Yeong Gyun Kim
|
Hadronic Invariant Mass Spectrum in B -> X_u l nu Decay with Lepton
Energy Cut
|
19 pages, 3 figures
|
Phys.Rev.D63:014005,2001
|
10.1103/PhysRevD.63.014005
|
YUMS 00-05
|
hep-ph hep-ex
| null |
We discuss the implications of charged lepton energy cut to the hadronic
invariant mass spectrum in charmless semileptonic B decays. Charged-lepton
energy cut is inevitable in order to remove secondary leptonic events such as b
-> c, tau -> l, and to identify the chaged leptons at detectors experimentally.
We consider three possible lepton energy cuts, E_l^{cuts} = 0.6,1.5,2.3 GeV,
and found that with the most probable cuts E_l^{cut} = 1.5 GeV and M_X^{max} =
1.5~(1.86) GeV, 45 ~ 60 % ~(58 ~ 67 %) of decay events survive. Therefore, B ->
X_u l nu decay events can be efficiently distinguished from B -> X_c l nu decay
events. We also discuss the possible model dependence on the results.
|
[
{
"created": "Wed, 28 Jun 2000 15:42:41 GMT",
"version": "v1"
}
] |
2011-02-01
|
[
[
"Jeong",
"K. K.",
""
],
[
"Kim",
"C. S.",
""
],
[
"Kim",
"Yeong Gyun",
""
]
] |
We discuss the implications of charged lepton energy cut to the hadronic invariant mass spectrum in charmless semileptonic B decays. Charged-lepton energy cut is inevitable in order to remove secondary leptonic events such as b -> c, tau -> l, and to identify the chaged leptons at detectors experimentally. We consider three possible lepton energy cuts, E_l^{cuts} = 0.6,1.5,2.3 GeV, and found that with the most probable cuts E_l^{cut} = 1.5 GeV and M_X^{max} = 1.5~(1.86) GeV, 45 ~ 60 % ~(58 ~ 67 %) of decay events survive. Therefore, B -> X_u l nu decay events can be efficiently distinguished from B -> X_c l nu decay events. We also discuss the possible model dependence on the results.
|
2401.15465
|
Howard Baer
|
Howard Baer, Vernon Barger and Dakotah Martinez
|
Supersymmetry with scalar sequestering
|
29 pages including 27 .png frames
| null | null |
OU-HEP-240130
|
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
Supersymmetric models with a strongly interacting superconformal hidden
sector (HS) may drive soft SUSY breaking scalar masses, bilinear soft term B\mu
and Higgs combinations m_{H_{u,d}}^2+\mu^2 to small values at some intermediate
scale, leading to unique sparticle mass spectra along with possibly diminished
finetuning in spite of a large superpotential $\mu$ parameter. We set up a
computer code to calculate such spectra, which are then susceptible to a
variety of constraints: 1. possible charge-or-color breaking (CCB) minima in
the scalar potential, 2. unbounded from below (UFB) scalar potential, 3.
improper electroweak symmetry breaking, 4. a charged or sneutrino lightest SUSY
particle (LSP), 5. generating m_h~ 125 GeV, 6. consistency with LHC sparticle
mass limits, and 7. naturalness. We find this bevy of constraints leaves little
or no viable parameter space for the case where hidden sector dynamics
dominates MSSM running, even for the case of non-universal gaugino masses. For
the case with moderate HS running with comparable MSSM running, and with
universal gaugino masses, then the finetuning is ameliorated, but nonetheless
remains high. Viable spectra with moderate HS running and with low finetuning
and large mu can be found for non-universal gaugino masses.
|
[
{
"created": "Sat, 27 Jan 2024 17:20:23 GMT",
"version": "v1"
}
] |
2024-01-30
|
[
[
"Baer",
"Howard",
""
],
[
"Barger",
"Vernon",
""
],
[
"Martinez",
"Dakotah",
""
]
] |
Supersymmetric models with a strongly interacting superconformal hidden sector (HS) may drive soft SUSY breaking scalar masses, bilinear soft term B\mu and Higgs combinations m_{H_{u,d}}^2+\mu^2 to small values at some intermediate scale, leading to unique sparticle mass spectra along with possibly diminished finetuning in spite of a large superpotential $\mu$ parameter. We set up a computer code to calculate such spectra, which are then susceptible to a variety of constraints: 1. possible charge-or-color breaking (CCB) minima in the scalar potential, 2. unbounded from below (UFB) scalar potential, 3. improper electroweak symmetry breaking, 4. a charged or sneutrino lightest SUSY particle (LSP), 5. generating m_h~ 125 GeV, 6. consistency with LHC sparticle mass limits, and 7. naturalness. We find this bevy of constraints leaves little or no viable parameter space for the case where hidden sector dynamics dominates MSSM running, even for the case of non-universal gaugino masses. For the case with moderate HS running with comparable MSSM running, and with universal gaugino masses, then the finetuning is ameliorated, but nonetheless remains high. Viable spectra with moderate HS running and with low finetuning and large mu can be found for non-universal gaugino masses.
|
2211.00042
|
Henrique Brito C\^amara
|
D. M. Barreiros, H. B. C\^amara, R. G. Felipe, F. R. Joaquim
|
Scalar-singlet assisted leptogenesis with CP violation from the vacuum
|
44 LaTeX pages; 7 figures
| null |
10.1007/JHEP01(2023)010
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In the vanilla type-I seesaw leptogenesis scenario, CP violation required to
generate the lepton asymmetries in the heavy Majorana neutrino decays stem from
complex Dirac-type Yukawa couplings. In this paper we explore the case in which
that CP violation originates from the vacuum expectation value of a complex
scalar singlet at a very high scale. This non-trivial CP-violating phase can be
successfully communicated to the low-energy neutrino sector via the heavy
neutrino portal. The new scalar-singlet degrees of freedom generate new
contributions to the CP asymmetries relevant for leptogenesis not only at the
one-loop level but also through tree-level three-body decays. These are
computed here for an arbitrary number of heavy neutrinos, Higgs doublets and
scalar singlets. We also take into account the new decays and scattering
processes that enter the unflavoured Boltzmann equations governing the
heavy-neutrino particle densities and the $(B-L)$-asymmetry evolution. Having
established the framework of interest, we present a simple model with two RH
neutrinos, two Higgs doublets and a complex scalar singlet, supplemented with a
$\mathcal{Z}_8$ flavour symmetry. This symmetry minimises the number of free
parameters without compromising the possibility of spontaneous CP violation and
compatibility with neutrino data. In fact, the only viable $\mathcal{Z}_8$
charge assignment shows a preference for a non-trivial spontaneous CP-violating
phase, which in turn leads to a non-vanishing CP asymmetry due to the direct
link between high- and low-energy CP violation. An interesting feature of this
simple setup is that the usual wave and vertex type-I seesaw contributions to
the CP asymmetry vanish due to the $\mathcal{Z}_8$ symmetry. Thus, the observed
baryon-to-photon ratio can be explained thanks to the new couplings among the
heavy neutrinos and the new scalar degrees of freedom.
|
[
{
"created": "Mon, 31 Oct 2022 18:00:14 GMT",
"version": "v1"
}
] |
2023-01-25
|
[
[
"Barreiros",
"D. M.",
""
],
[
"Câmara",
"H. B.",
""
],
[
"Felipe",
"R. G.",
""
],
[
"Joaquim",
"F. R.",
""
]
] |
In the vanilla type-I seesaw leptogenesis scenario, CP violation required to generate the lepton asymmetries in the heavy Majorana neutrino decays stem from complex Dirac-type Yukawa couplings. In this paper we explore the case in which that CP violation originates from the vacuum expectation value of a complex scalar singlet at a very high scale. This non-trivial CP-violating phase can be successfully communicated to the low-energy neutrino sector via the heavy neutrino portal. The new scalar-singlet degrees of freedom generate new contributions to the CP asymmetries relevant for leptogenesis not only at the one-loop level but also through tree-level three-body decays. These are computed here for an arbitrary number of heavy neutrinos, Higgs doublets and scalar singlets. We also take into account the new decays and scattering processes that enter the unflavoured Boltzmann equations governing the heavy-neutrino particle densities and the $(B-L)$-asymmetry evolution. Having established the framework of interest, we present a simple model with two RH neutrinos, two Higgs doublets and a complex scalar singlet, supplemented with a $\mathcal{Z}_8$ flavour symmetry. This symmetry minimises the number of free parameters without compromising the possibility of spontaneous CP violation and compatibility with neutrino data. In fact, the only viable $\mathcal{Z}_8$ charge assignment shows a preference for a non-trivial spontaneous CP-violating phase, which in turn leads to a non-vanishing CP asymmetry due to the direct link between high- and low-energy CP violation. An interesting feature of this simple setup is that the usual wave and vertex type-I seesaw contributions to the CP asymmetry vanish due to the $\mathcal{Z}_8$ symmetry. Thus, the observed baryon-to-photon ratio can be explained thanks to the new couplings among the heavy neutrinos and the new scalar degrees of freedom.
|
2005.08037
|
Seishi Enomoto
|
Seishi Enomoto, Chengfeng Cai, Zhao-Huan Yu and Hong-Hao Zhang
|
Leptogenesis due to oscillating Higgs field
|
13 pages, 3 figures
| null |
10.1140/epjc/s10052-020-08672-7
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We propose a new leptogenesis scenario in which the lepton asymmetry and
matter particles are simultaneously generated due to the coherent oscillating
Higgs background. To demonstrate the possibility of our scenario, we consider
the type-I seesaw model as an illuminating example and show the numerical
analysis. In order to generate the required lepton number $|n_L/s| = 2.4 \times
10^{-10}$, we find that the scales of the Higgs background oscillation and the
lightest right-handed neutrinos mass are required to be higher than $10^{14}$
GeV
|
[
{
"created": "Sat, 16 May 2020 16:40:47 GMT",
"version": "v1"
},
{
"created": "Sun, 20 Sep 2020 12:46:36 GMT",
"version": "v2"
},
{
"created": "Thu, 3 Dec 2020 05:48:44 GMT",
"version": "v3"
}
] |
2020-12-30
|
[
[
"Enomoto",
"Seishi",
""
],
[
"Cai",
"Chengfeng",
""
],
[
"Yu",
"Zhao-Huan",
""
],
[
"Zhang",
"Hong-Hao",
""
]
] |
We propose a new leptogenesis scenario in which the lepton asymmetry and matter particles are simultaneously generated due to the coherent oscillating Higgs background. To demonstrate the possibility of our scenario, we consider the type-I seesaw model as an illuminating example and show the numerical analysis. In order to generate the required lepton number $|n_L/s| = 2.4 \times 10^{-10}$, we find that the scales of the Higgs background oscillation and the lightest right-handed neutrinos mass are required to be higher than $10^{14}$ GeV
|
0712.0287
|
Monika Kollar
|
Wolfgang Hollik, Monika Kollar, and Maike K. Trenkel
|
Hadronic production of top-squark pairs with electroweak NLO
contributions
|
27 pages, 17 figures, 2 tables
|
JHEP 0802:018,2008
|
10.1088/1126-6708/2008/02/018
|
MPP-2007-149
|
hep-ph
| null |
Presented are complete next-to-leading order electroweak (NLO EW) corrections
to top-squark pair production at the Large Hadron Collider (LHC) within the
Minimal Supersymmetric Standard Model (MSSM). At this order, also effects from
the interference of EW and QCD contributions have to be taken into account.
Moreover, photon-induced top-squark production is considered as an additional
partonic channel, which arises from the non-zero photon density in the proton.
|
[
{
"created": "Mon, 3 Dec 2007 13:59:12 GMT",
"version": "v1"
}
] |
2009-02-18
|
[
[
"Hollik",
"Wolfgang",
""
],
[
"Kollar",
"Monika",
""
],
[
"Trenkel",
"Maike K.",
""
]
] |
Presented are complete next-to-leading order electroweak (NLO EW) corrections to top-squark pair production at the Large Hadron Collider (LHC) within the Minimal Supersymmetric Standard Model (MSSM). At this order, also effects from the interference of EW and QCD contributions have to be taken into account. Moreover, photon-induced top-squark production is considered as an additional partonic channel, which arises from the non-zero photon density in the proton.
|
1505.01826
|
Stephen Parke
|
Hisakazu Minakata and Stephen J Parke
|
Simple and Compact Expressions for Neutrino Oscillation Probabilities in
Matter
|
34 pages, 3 figures
| null |
10.1007/JHEP01(2016)180
|
FERNILAB-PUB-15-196-T, NORDITA-2015-120
|
hep-ph
|
http://creativecommons.org/publicdomain/zero/1.0/
|
We reformulate perturbation theory for neutrino oscillations in matter with
an expansion parameter related to the ratio of the solar to the atmospheric
$\Delta m^2$ scales. Unlike previous works, we use a renormalized basis in
which certain first-order effects are taken into account in the zeroth-order
Hamiltonian. We show that the new framework has an exceptional feature that
leads to the neutrino oscillation probability in matter with the same structure
as in vacuum to first order in the expansion parameter. It facilitates
immediate physical interpretation of the formulas, and makes the expressions
for the neutrino oscillation probabilities extremely simple and compact. We
find, for example, that the $\nu_e$ disappearance probability at this order is
of a simple two-flavor form with an appropriately identified mixing angle and
$\Delta m^2$. More generally, all the oscillation probabilities can be written
in the universal form with the channel-discrimination coefficient of $0,~\pm1$
or simple functions of $\theta_{23}$. Despite their simple forms they include
all order effects of $\theta_{13}$ and all order effects of the matter
potential, to first order in our expansion parameter.
|
[
{
"created": "Thu, 7 May 2015 19:44:08 GMT",
"version": "v1"
},
{
"created": "Wed, 23 Dec 2015 17:45:57 GMT",
"version": "v2"
}
] |
2016-03-23
|
[
[
"Minakata",
"Hisakazu",
""
],
[
"Parke",
"Stephen J",
""
]
] |
We reformulate perturbation theory for neutrino oscillations in matter with an expansion parameter related to the ratio of the solar to the atmospheric $\Delta m^2$ scales. Unlike previous works, we use a renormalized basis in which certain first-order effects are taken into account in the zeroth-order Hamiltonian. We show that the new framework has an exceptional feature that leads to the neutrino oscillation probability in matter with the same structure as in vacuum to first order in the expansion parameter. It facilitates immediate physical interpretation of the formulas, and makes the expressions for the neutrino oscillation probabilities extremely simple and compact. We find, for example, that the $\nu_e$ disappearance probability at this order is of a simple two-flavor form with an appropriately identified mixing angle and $\Delta m^2$. More generally, all the oscillation probabilities can be written in the universal form with the channel-discrimination coefficient of $0,~\pm1$ or simple functions of $\theta_{23}$. Despite their simple forms they include all order effects of $\theta_{13}$ and all order effects of the matter potential, to first order in our expansion parameter.
|
hep-ph/0001156
|
Peter Tinyakov
|
Yu.A. Kubyshin (INP, Moscow State University, Moscow) and P.G.
Tinyakov (INR, Moscow)
|
Instanton propagator in scalar model: exact expression and contribution
to instanton induced processes
|
17 pages, Latex, 1 ps figure. Based on the talk given by Yu.K. at the
XIVth Workshop on Quantum Field Theory and High Energy Physics (May 27 - June
2, 1999, Moscow
| null | null |
INR-PT-00-017
|
hep-ph
| null |
The propagator in the instanton background in the -lambda phi^4 scalar model
in four dimensions is studied. Leading and sub-leading terms of its asymptotics
for large momenta and its on-shell double residue are calculated. These results
are applied to the analysis of the initial state and initial-final state
corrections and the calculation of the next-to-leading (propagator) correction
to the exponent of the cross section of multiparticle scattering processes.
|
[
{
"created": "Mon, 17 Jan 2000 09:26:18 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Kubyshin",
"Yu. A.",
"",
"INP, Moscow State University, Moscow"
],
[
"Tinyakov",
"P. G.",
"",
"INR, Moscow"
]
] |
The propagator in the instanton background in the -lambda phi^4 scalar model in four dimensions is studied. Leading and sub-leading terms of its asymptotics for large momenta and its on-shell double residue are calculated. These results are applied to the analysis of the initial state and initial-final state corrections and the calculation of the next-to-leading (propagator) correction to the exponent of the cross section of multiparticle scattering processes.
|
hep-ph/9712307
|
Kaladi Babu
|
K.S. Babu (Institute for Advanced Study, Princeton), J.C. Pati
(University of Maryland) and F. Wilczek (Institute for Advanced Study,
Princeton)
|
Suggested new modes in supersymmetric proton decay
|
17 pages LateX, includes 4 figures
|
Phys.Lett. B423 (1998) 337-347
|
10.1016/S0370-2693(98)00108-7
|
IASSNS-HEP-97-136, UMD-PP-98-55
|
hep-ph
| null |
We show that in supersymmetric unified theories such as SO(10),
implementation of the see-saw mechanism for neutrino masses introduces a new
set of color triplet fields and thereby a new source of d=5 proton decay
operators. For neutrino masses in a plausible range, these operators are found
to have the right strength to yield observable, but not yet excluded, proton
decay rates. The flavor structure of the new operators is distinctive. Proton
decay modes into a charged lepton, such as l^+ \pi^0, l^+ K^0 and l^+ \eta
where l = e or \mu, can become prominent, even for low or moderate values of
tan(\beta) < 10, along with the \nu K^+ and \nu \pi^+ modes. A distinctive
feature is the charged lepton modes involving an e^+ and/or a \mu^+ with the
ratio \Gamma(l^+ K^0):\Gamma(l^+ \pi^0) = 2:1.
|
[
{
"created": "Mon, 8 Dec 1997 22:55:05 GMT",
"version": "v1"
}
] |
2009-10-30
|
[
[
"Babu",
"K. S.",
"",
"Institute for Advanced Study, Princeton"
],
[
"Pati",
"J. C.",
"",
"University of Maryland"
],
[
"Wilczek",
"F.",
"",
"Institute for Advanced Study,\n Princeton"
]
] |
We show that in supersymmetric unified theories such as SO(10), implementation of the see-saw mechanism for neutrino masses introduces a new set of color triplet fields and thereby a new source of d=5 proton decay operators. For neutrino masses in a plausible range, these operators are found to have the right strength to yield observable, but not yet excluded, proton decay rates. The flavor structure of the new operators is distinctive. Proton decay modes into a charged lepton, such as l^+ \pi^0, l^+ K^0 and l^+ \eta where l = e or \mu, can become prominent, even for low or moderate values of tan(\beta) < 10, along with the \nu K^+ and \nu \pi^+ modes. A distinctive feature is the charged lepton modes involving an e^+ and/or a \mu^+ with the ratio \Gamma(l^+ K^0):\Gamma(l^+ \pi^0) = 2:1.
|
hep-ph/9507216
| null |
Ernestos N. Argyres, Wim Beenakker, Ansgar Denner, Stefan Dittmaier,
Jiri Hoogland, Ronald Kleiss, Geert Jan van Oldenborgh, Costas G.
Papadopoulos and Giampiero Passarino
|
Stable Calculations for Unstable Particles: Restoring Gauge Invariance
|
13 pages LaTeX inc 1 figure, uses epsf, axodraw. The ps file is
available as ftp://rulgm4.leidenuniv.nl/pub/preprints/stable.ps or on
http://rulgm4.leidenuniv.nl/ under preprints. Added two references
|
Phys.Lett. B358 (1995) 339-346
|
10.1016/0370-2693(95)01002-8
|
INLO-PUB-8/95
|
hep-ph
| null |
We discuss theoretical and phenomenological aspects of the use of boson
propagators with energy-dependent widths in predictions for high-energy
scattering processes. In general, gauge invariance is violated in such
calculations. We discuss several approaches to restore gauge invariance,
necessary for a reliable result. The most promising method is the addition of
the relevant parts of the fermionic corrections, which fulfills all Ward
identities. The numerical difference between this and other approaches is
studied. A number of recommendations are given for LEP2 computations.
|
[
{
"created": "Tue, 4 Jul 1995 13:46:23 GMT",
"version": "v1"
},
{
"created": "Thu, 6 Jul 1995 12:34:53 GMT",
"version": "v2"
}
] |
2009-10-28
|
[
[
"Argyres",
"Ernestos N.",
""
],
[
"Beenakker",
"Wim",
""
],
[
"Denner",
"Ansgar",
""
],
[
"Dittmaier",
"Stefan",
""
],
[
"Hoogland",
"Jiri",
""
],
[
"Kleiss",
"Ronald",
""
],
[
"van Oldenborgh",
"Geert Jan",
""
],
[
"Papadopoulos",
"Costas G.",
""
],
[
"Passarino",
"Giampiero",
""
]
] |
We discuss theoretical and phenomenological aspects of the use of boson propagators with energy-dependent widths in predictions for high-energy scattering processes. In general, gauge invariance is violated in such calculations. We discuss several approaches to restore gauge invariance, necessary for a reliable result. The most promising method is the addition of the relevant parts of the fermionic corrections, which fulfills all Ward identities. The numerical difference between this and other approaches is studied. A number of recommendations are given for LEP2 computations.
|
hep-ph/9608240
| null |
Agnieszka Zalewska (Institute of Nuclear Physics, Krak\'ow) and Kacper
Zalewski (Jagellonian University and Institute of Nuclear Physics, Krak\'ow)
|
Heavy baryon masses
|
Presented at the 3rd German-Russian Workshop on Progress in Heavy
Quark Physics, Dubna 20-22 May 1996. 5 pages, no figures, Latex file
| null | null | null |
hep-ph
| null |
Simple and plausible rules are used to correlate the masses of the
ground-state baryons containing single heavy ($b$ or $c$) quarks. A comparison
with the experimental data shows that the observed mass difference between the
$\Sigma_b$ and the $\Sigma^*_b$ is unexpectedly large. Predictions for the
masses of the yet undiscovered heavy baryons are given.
|
[
{
"created": "Tue, 6 Aug 1996 13:21:00 GMT",
"version": "v1"
},
{
"created": "Wed, 7 Aug 1996 11:44:00 GMT",
"version": "v2"
}
] |
2008-02-03
|
[
[
"Zalewska",
"Agnieszka",
"",
"Institute of Nuclear Physics, Kraków"
],
[
"Zalewski",
"Kacper",
"",
"Jagellonian University and Institute of Nuclear Physics, Kraków"
]
] |
Simple and plausible rules are used to correlate the masses of the ground-state baryons containing single heavy ($b$ or $c$) quarks. A comparison with the experimental data shows that the observed mass difference between the $\Sigma_b$ and the $\Sigma^*_b$ is unexpectedly large. Predictions for the masses of the yet undiscovered heavy baryons are given.
|
1912.13508
|
Shehu AbdusSalam
|
S.S. AbdusSalam, M.Z. Abyaneh, F. Ghelichkhani, M. Noormandipour
|
Majorana phases in high-scale mixings unification hypotheses
|
v2: major changes were made
|
International Journal of Modern Physics A Vol. 36, No. 13 (2021)
2150077 (17 pages)
|
10.1142/S0217751X21500779
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
For addressing the remarkable difference between neutrino and quark mixings,
high-scale mixings relations (HSMR) or unification (HSMU) hypothe\ ses were
proposed. These phenomenology frameworks have been explored with respect to
bounds from neutrino oscillations and relevant cosmologic\ al data. However
there are caveats with regards to assessing the hypotheses' compatibility with
data in a statistically robust and convergent \ manner because most analysis
employ a few sample of points in model parameters' space. A remedy could be
achieved by using Bayesian algorithms\
for the parameters' space exploration. Using this approach, we made global
fits of the HSMU and HSMR models to data and find compatible param\ eter
regions, including for Majorana phases. The posterior samples could be used for
studying correlations between neutrino observables and pr\ ospects for updates
of related experiments.
|
[
{
"created": "Tue, 31 Dec 2019 18:55:28 GMT",
"version": "v1"
},
{
"created": "Mon, 14 Jun 2021 13:58:28 GMT",
"version": "v2"
}
] |
2021-06-15
|
[
[
"AbdusSalam",
"S. S.",
""
],
[
"Abyaneh",
"M. Z.",
""
],
[
"Ghelichkhani",
"F.",
""
],
[
"Noormandipour",
"M.",
""
]
] |
For addressing the remarkable difference between neutrino and quark mixings, high-scale mixings relations (HSMR) or unification (HSMU) hypothe\ ses were proposed. These phenomenology frameworks have been explored with respect to bounds from neutrino oscillations and relevant cosmologic\ al data. However there are caveats with regards to assessing the hypotheses' compatibility with data in a statistically robust and convergent \ manner because most analysis employ a few sample of points in model parameters' space. A remedy could be achieved by using Bayesian algorithms\ for the parameters' space exploration. Using this approach, we made global fits of the HSMU and HSMR models to data and find compatible param\ eter regions, including for Majorana phases. The posterior samples could be used for studying correlations between neutrino observables and pr\ ospects for updates of related experiments.
|
1007.1728
|
Carlos E. Yaguna
|
Ki-Young Choi, Diego Restrepo, Carlos E. Yaguna, Oscar Zapata
|
Indirect detection of gravitino dark matter including its three-body
decays
|
21 pages,16 figures v2: one numerical error corrected, one figure
added, main results unchanged
|
JCAP 1010:033,2010
|
10.1088/1475-7516/2010/10/033
|
PNUTP-10-A08
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
It was recently pointed out that in supersymmetric scenarios with gravitino
dark matter and bilinear R-parity violation, gravitinos with masses below Mw
typically decay with a sizable branching ratio into the 3-body final states
W^*+lepton and Z^*+neutrino. In this paper we study the indirect detection
signatures of gravitino dark matter including such final states. First, we
obtain the gamma ray spectrum from gravitino decays, which features a
monochromatic contribution from the decay into photon+neutrino and a continuum
contribution from the three-body decays. After studying its dependence on
supersymmetric parameters, we compute the expected gamma ray fluxes and derive
new constraints, from recent FERMI data, on the R-parity breaking parameter and
on the gravitino lifetime. Indirect detection via antimatter searches, a new
possibility brought about by the three-body final states, is also analyzed. For
models compatible with the gamma ray observations, the positron signal is found
to be negligible whereas the antiproton one can be significant.
|
[
{
"created": "Sat, 10 Jul 2010 16:13:29 GMT",
"version": "v1"
},
{
"created": "Mon, 31 Jan 2011 11:11:49 GMT",
"version": "v2"
}
] |
2011-02-01
|
[
[
"Choi",
"Ki-Young",
""
],
[
"Restrepo",
"Diego",
""
],
[
"Yaguna",
"Carlos E.",
""
],
[
"Zapata",
"Oscar",
""
]
] |
It was recently pointed out that in supersymmetric scenarios with gravitino dark matter and bilinear R-parity violation, gravitinos with masses below Mw typically decay with a sizable branching ratio into the 3-body final states W^*+lepton and Z^*+neutrino. In this paper we study the indirect detection signatures of gravitino dark matter including such final states. First, we obtain the gamma ray spectrum from gravitino decays, which features a monochromatic contribution from the decay into photon+neutrino and a continuum contribution from the three-body decays. After studying its dependence on supersymmetric parameters, we compute the expected gamma ray fluxes and derive new constraints, from recent FERMI data, on the R-parity breaking parameter and on the gravitino lifetime. Indirect detection via antimatter searches, a new possibility brought about by the three-body final states, is also analyzed. For models compatible with the gamma ray observations, the positron signal is found to be negligible whereas the antiproton one can be significant.
|
1606.03250
|
Eugene Zabrodin
|
L. Bravina, B.H. Brusheim Johansson, J. Crkovsk\'a, G. Eyyubova, V.
Korotkikh, I. Lokhtin, L. Malinina, E. Nazarova, S. Petrushanko, A. Snigirev,
E. Zabrodin
|
HYDRO + JETS (HYDJET++) event generator for Pb+Pb collisions at LHC
|
8 pages, 6 figures, contribution to Proceedings of the Winter
Workshop on Nuclear Dynamics 2016
|
Journal of Physics: Conference Series 736 (2016) 012024
|
10.1088/1742-6596/736/1/012024
| null |
hep-ph nucl-ex nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The Monte Carlo event generator HYDJET++ is one of the few generators,
designed for the calculations of heavy-ion collisions at ultrarelativistic
energies, which combine treatment of soft hydro-like processes with the
description of jets traversing the hot and dense partonic medium. The model is
employed to study the azimuthal anisotropy phenomena, dihadron angular
correlations and event-by-event (EbyE) fluctuations of the anisotropic flow in
Pb+Pb collisions at $\sqrt{s_{NN}} = 2.76$ TeV. The interplay of soft and hard
processes describes the violation of the mass hierarchy of meson and baryon
elliptic and triangular flows at p_T > 2 GeV/c, the fall-off of the flow
harmonics at intermediate transverse momenta, and the worsening of the
number-of-constituent-quark (NCQ) scaling of elliptic/triangular flow at LHC
compared to RHIC energies. The cross-talk of v_2 and v_3 leads to emergence of
higher order harmonics in the model and to appearance of the ridge structure in
dihadron angular correlations in a broad pseudorapidity range. HYDJET++
possesses also the dynamical EbyE fluctuations of the anisotropic flow. The
model results agree well with the experimental data.
|
[
{
"created": "Fri, 10 Jun 2016 09:53:35 GMT",
"version": "v1"
}
] |
2016-08-29
|
[
[
"Bravina",
"L.",
""
],
[
"Johansson",
"B. H. Brusheim",
""
],
[
"Crkovská",
"J.",
""
],
[
"Eyyubova",
"G.",
""
],
[
"Korotkikh",
"V.",
""
],
[
"Lokhtin",
"I.",
""
],
[
"Malinina",
"L.",
""
],
[
"Nazarova",
"E.",
""
],
[
"Petrushanko",
"S.",
""
],
[
"Snigirev",
"A.",
""
],
[
"Zabrodin",
"E.",
""
]
] |
The Monte Carlo event generator HYDJET++ is one of the few generators, designed for the calculations of heavy-ion collisions at ultrarelativistic energies, which combine treatment of soft hydro-like processes with the description of jets traversing the hot and dense partonic medium. The model is employed to study the azimuthal anisotropy phenomena, dihadron angular correlations and event-by-event (EbyE) fluctuations of the anisotropic flow in Pb+Pb collisions at $\sqrt{s_{NN}} = 2.76$ TeV. The interplay of soft and hard processes describes the violation of the mass hierarchy of meson and baryon elliptic and triangular flows at p_T > 2 GeV/c, the fall-off of the flow harmonics at intermediate transverse momenta, and the worsening of the number-of-constituent-quark (NCQ) scaling of elliptic/triangular flow at LHC compared to RHIC energies. The cross-talk of v_2 and v_3 leads to emergence of higher order harmonics in the model and to appearance of the ridge structure in dihadron angular correlations in a broad pseudorapidity range. HYDJET++ possesses also the dynamical EbyE fluctuations of the anisotropic flow. The model results agree well with the experimental data.
|
0804.2477
|
Matthew Schwartz
|
David E. Kaplan and Matthew D. Schwartz
|
Constraining Light Colored Particles with Event Shapes
|
4 pages, 2 figures
|
Phys.Rev.Lett.101:022002,2008
|
10.1103/PhysRevLett.101.022002
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Using recently developed techniques for computing event shapes with
Soft-Collinear Effective Theory, LEP event shape data is used to derive strong
model-independent bounds on new colored particles. In the effective field
theory computation, colored particles contribute in loops not only to the
running of alpha_s but also to the running of hard, jet and soft functions.
Moreover, the differential distribution in the effective theory explicitly
probes many energy scales, so event shapes have strong sensitivity to new
particle thresholds. Using thrust data from ALEPH and OPAL, colored adjoint
fermions (such as a gluino) below 51.0 GeV are ruled out to 95% confidence
level. This is nearly an order-of-magnitude improvement over the previous
model-independent bound of 6.3 GeV.
|
[
{
"created": "Wed, 16 Apr 2008 16:04:50 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Kaplan",
"David E.",
""
],
[
"Schwartz",
"Matthew D.",
""
]
] |
Using recently developed techniques for computing event shapes with Soft-Collinear Effective Theory, LEP event shape data is used to derive strong model-independent bounds on new colored particles. In the effective field theory computation, colored particles contribute in loops not only to the running of alpha_s but also to the running of hard, jet and soft functions. Moreover, the differential distribution in the effective theory explicitly probes many energy scales, so event shapes have strong sensitivity to new particle thresholds. Using thrust data from ALEPH and OPAL, colored adjoint fermions (such as a gluino) below 51.0 GeV are ruled out to 95% confidence level. This is nearly an order-of-magnitude improvement over the previous model-independent bound of 6.3 GeV.
|
1905.05736
|
Keming Shen
|
Keming Shen, Gergely G\'abor Barnaf\"oldi and Tam\'as S\'andor Bir\'o
|
Hadronization within the Non-Extensive Approach and the Evolution of the
Parameters
|
18 pages, 13 figures
|
Eur. Phys. J. A (2019) 55: 126
|
10.1140/epja/i2019-12813-4
| null |
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We review transverse momentum distributions of various identified charged
particles stemming from high energy collisions fitted by various non-extensive
distributions as well as by the usual Boltzmann-Gibbs statistics. We
investigate the best-fit formula with the obtained $\chi^2/ndf$ values. We find
that the physical mass and $\sqrt{s}$ scaling become more explicit with heavier
produced hadrons in both proton-proton and heavy-ion collisions. The spectral
shape parameters, in particular the temperature $T$ and the non-extensive
Tsallis parameter $q$, do exhibit an almost linear dependence with the
centrality-dependence in heavy-ion collisions.
|
[
{
"created": "Tue, 14 May 2019 17:30:28 GMT",
"version": "v1"
},
{
"created": "Sat, 10 Aug 2019 14:22:31 GMT",
"version": "v2"
},
{
"created": "Tue, 13 Aug 2019 02:23:29 GMT",
"version": "v3"
}
] |
2019-08-14
|
[
[
"Shen",
"Keming",
""
],
[
"Barnaföldi",
"Gergely Gábor",
""
],
[
"Biró",
"Tamás Sándor",
""
]
] |
We review transverse momentum distributions of various identified charged particles stemming from high energy collisions fitted by various non-extensive distributions as well as by the usual Boltzmann-Gibbs statistics. We investigate the best-fit formula with the obtained $\chi^2/ndf$ values. We find that the physical mass and $\sqrt{s}$ scaling become more explicit with heavier produced hadrons in both proton-proton and heavy-ion collisions. The spectral shape parameters, in particular the temperature $T$ and the non-extensive Tsallis parameter $q$, do exhibit an almost linear dependence with the centrality-dependence in heavy-ion collisions.
|
1305.0581
|
Christian Sturm
|
Christian Sturm
|
Leptonic contributions to the effective electromagnetic coupling at
four-loop order in QED
|
26 pages, 4 figures
|
Nucl.Phys. B874 (2013) 698-719
|
10.1016/j.nuclphysb.2013.06.009
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The running of the effective electromagnetic coupling is for many electroweak
observables the dominant correction. It plays an important role for deriving
constraints on the Standard Model in the context of electroweak precision
measurements. We compute the four-loop QED corrections to the running of the
effective electromagnetic coupling and perform a numerical evaluation of the
different gauge invariant subsets.
|
[
{
"created": "Thu, 2 May 2013 21:15:27 GMT",
"version": "v1"
}
] |
2013-07-15
|
[
[
"Sturm",
"Christian",
""
]
] |
The running of the effective electromagnetic coupling is for many electroweak observables the dominant correction. It plays an important role for deriving constraints on the Standard Model in the context of electroweak precision measurements. We compute the four-loop QED corrections to the running of the effective electromagnetic coupling and perform a numerical evaluation of the different gauge invariant subsets.
|
hep-ph/0101003
|
Victor S. Fadin
|
V.S. Fadin (Novosibirsk)
|
Non-Forward BFKL at Next-to-Leading Approximation
|
Talk given at DIFFRACTION 2000: International Workshop on Diffraction
in High-energy and Nuclear Physics, Cetraro, Cosenza, Italy, 2-7 Sep 2000
|
Nucl.Phys.Proc.Suppl. 99A (2001) 204-212
|
10.1016/S0920-5632(01)01335-4
| null |
hep-ph
| null |
Representation of non-forward scattering amplitudes in the BFKL approach is
discussed and the results obtained in the next-to leading order are briefly
reviewed.
|
[
{
"created": "Sat, 30 Dec 2000 12:58:10 GMT",
"version": "v1"
}
] |
2009-11-07
|
[
[
"Fadin",
"V. S.",
"",
"Novosibirsk"
]
] |
Representation of non-forward scattering amplitudes in the BFKL approach is discussed and the results obtained in the next-to leading order are briefly reviewed.
|
2102.03491
|
Hao-Lin Wang
|
Yi Liao, Xiao-Dong Ma, Hao-Lin Wang
|
Effective field theory approach to lepton number violating $\tau$ decays
|
16 pages, 4 figures, 4 tables
|
Chin. Phys. C 45, no.7, 073102 (2021)
|
10.1088/1674-1137/abf72e
| null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
We continue our endeavor to investigate lepton number violating (LNV)
processes at low energy in the framework of effective field theory (EFT). In
this work we study the LNV tau decays $\tau^+\rightarrow \ell^-P_i^{+}P_j^{+}$,
where $\ell=e,~\mu$ and $P^+_{i,j}$ are the lowest-lying charged pseudoscalars
$\pi^+,~K^+$. We analyze the dominant contributions in a series of EFTs from
high to low energy scales, namely, the standard model effective field theory
(SMEFT), the low-energy effective field theory (LEFT), and the chiral
perturbation theory ($\chi$PT). The decay branching ratios are expressed in
terms of the Wilson coefficients of dimension-five and -seven operators in
SMEFT and hadronic low energy constants. These Wilson coefficients involve the
first and second generations of quarks and all generations of leptons and thus
cannot be explored in low energy processes such as nuclear neutrinoless double
decay or LNV kaon decays. Unfortunately, the current experimental upper limits
on the branching ratios are too weak to set useful constraints on those
coefficients. Or, if we assume the new physics scale is larger than 1 TeV, the
branching ratios are well below the current experimental bounds. We also
estimate hadronic uncertainties incurred in applying $\chi$PT to $\tau$ decays
by computing one-loop chiral logarithms and attempt to improve convergence of
chiral perturbation by employing dispersion relations in the short-distance
part of the decay amplitudes.
|
[
{
"created": "Sat, 6 Feb 2021 03:05:27 GMT",
"version": "v1"
},
{
"created": "Fri, 30 Jul 2021 06:30:18 GMT",
"version": "v2"
}
] |
2021-08-02
|
[
[
"Liao",
"Yi",
""
],
[
"Ma",
"Xiao-Dong",
""
],
[
"Wang",
"Hao-Lin",
""
]
] |
We continue our endeavor to investigate lepton number violating (LNV) processes at low energy in the framework of effective field theory (EFT). In this work we study the LNV tau decays $\tau^+\rightarrow \ell^-P_i^{+}P_j^{+}$, where $\ell=e,~\mu$ and $P^+_{i,j}$ are the lowest-lying charged pseudoscalars $\pi^+,~K^+$. We analyze the dominant contributions in a series of EFTs from high to low energy scales, namely, the standard model effective field theory (SMEFT), the low-energy effective field theory (LEFT), and the chiral perturbation theory ($\chi$PT). The decay branching ratios are expressed in terms of the Wilson coefficients of dimension-five and -seven operators in SMEFT and hadronic low energy constants. These Wilson coefficients involve the first and second generations of quarks and all generations of leptons and thus cannot be explored in low energy processes such as nuclear neutrinoless double decay or LNV kaon decays. Unfortunately, the current experimental upper limits on the branching ratios are too weak to set useful constraints on those coefficients. Or, if we assume the new physics scale is larger than 1 TeV, the branching ratios are well below the current experimental bounds. We also estimate hadronic uncertainties incurred in applying $\chi$PT to $\tau$ decays by computing one-loop chiral logarithms and attempt to improve convergence of chiral perturbation by employing dispersion relations in the short-distance part of the decay amplitudes.
|
hep-ph/0304135
|
Fu-Sin Ling
|
Fu-Sin Ling
|
Neutrino Mixings and Unified Theories
|
to appear in the proceedings of the 38th Rencontres of Moriond
(Electroweak Interactions and Unified Theories) - 2003
| null | null |
UFIFT-HEP-03-8
|
hep-ph
| null |
The recent neutrino data converge towards a 3$\nu$ scheme with two large and
one small mixing angles. Their implications for model-building are discussed.
Some possible components of a flavor symmetry over quarks and leptons are
singled out. We suggest that they can be naturally embedded in a unified
structure with a replicated gauge group.
|
[
{
"created": "Tue, 15 Apr 2003 00:24:43 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Ling",
"Fu-Sin",
""
]
] |
The recent neutrino data converge towards a 3$\nu$ scheme with two large and one small mixing angles. Their implications for model-building are discussed. Some possible components of a flavor symmetry over quarks and leptons are singled out. We suggest that they can be naturally embedded in a unified structure with a replicated gauge group.
|
2004.06125
|
Cari Cesarotti
|
Cari Cesarotti and Jesse Thaler
|
A Robust Measure of Event Isotropy at Colliders
|
49 pages, 31 figures, 2 tables. v3: Minor discussion added to match
JHEP version
| null | null |
MIT-CTP 5195
|
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We introduce a new event shape observable -- event isotropy -- that
quantifies how close the radiation pattern of a collider event is to a uniform
distribution. This observable is based on a normalized version of the energy
mover's distance, which is the minimum "work" needed to rearrange one radiation
pattern into another of equal energy. We investigate the utility of event
isotropy both at electron-positron colliders, where events are compared to a
perfectly spherical radiation pattern, as well as at proton-proton colliders,
where the natural comparison is to either cylindrical or ring-like patterns.
Compared to traditional event shape observables like sphericity and thrust,
event isotropy exhibits a larger dynamic range for high-multiplicity events.
This enables event isotropy to not only distinguish between dijet and multijet
processes but also separate uniform N-body phase space configurations for
different values of N. As a key application of this new observable, we study
its performance to characterize strongly-coupled new physics scenarios with
isotropic collider signatures.
|
[
{
"created": "Mon, 13 Apr 2020 18:00:03 GMT",
"version": "v1"
},
{
"created": "Tue, 5 May 2020 19:45:47 GMT",
"version": "v2"
},
{
"created": "Tue, 18 Aug 2020 15:37:40 GMT",
"version": "v3"
}
] |
2020-08-19
|
[
[
"Cesarotti",
"Cari",
""
],
[
"Thaler",
"Jesse",
""
]
] |
We introduce a new event shape observable -- event isotropy -- that quantifies how close the radiation pattern of a collider event is to a uniform distribution. This observable is based on a normalized version of the energy mover's distance, which is the minimum "work" needed to rearrange one radiation pattern into another of equal energy. We investigate the utility of event isotropy both at electron-positron colliders, where events are compared to a perfectly spherical radiation pattern, as well as at proton-proton colliders, where the natural comparison is to either cylindrical or ring-like patterns. Compared to traditional event shape observables like sphericity and thrust, event isotropy exhibits a larger dynamic range for high-multiplicity events. This enables event isotropy to not only distinguish between dijet and multijet processes but also separate uniform N-body phase space configurations for different values of N. As a key application of this new observable, we study its performance to characterize strongly-coupled new physics scenarios with isotropic collider signatures.
|
hep-ph/9907376
|
Joannis Papavassiliou
|
J. Papavassiliou and K. Philippides
|
Probing the $WW\gamma$ vertex at hadron colliders
|
15 pages, Latex, 1 figure, uses axodraw
|
Phys.Rev.D60:113007,1999
|
10.1103/PhysRevD.60.113007
|
CERN-TH/99-212
|
hep-ph
| null |
We present a new, model independent method for extracting bounds for the
anomalous $\gamma WW$ couplings from hadron collider experiments. At the
partonic level we introduce a set of three observables which are constructed
from the unpolarized differential cross-section for the process $d\bar{u}\to
W^{-}\gamma$ by appropriate convolution with a set of simple polynomials
depending only on the center-of-mass angle. One of these observables allows for
the direct determination of the anomalous coupling usually denoted by
$\Delta\kappa$, without any simplifying assumptions, and without relying on the
presence of a radiation zero. The other two observables impose two sum rules on
the remaining three anomalous couplings. The inclusion of the structure
functions is discussed in detail for both $p\bar{p}$ and $pp$ colliders. We
show that, whilst for $p\bar{p}$ experiments this can be accomplished
straightforwardly, in the $pp$ case one has to resort to somewhat more
elaborate techniques, such as the binning of events according to their
longitudinal momenta.
|
[
{
"created": "Thu, 15 Jul 1999 14:55:25 GMT",
"version": "v1"
}
] |
2011-03-23
|
[
[
"Papavassiliou",
"J.",
""
],
[
"Philippides",
"K.",
""
]
] |
We present a new, model independent method for extracting bounds for the anomalous $\gamma WW$ couplings from hadron collider experiments. At the partonic level we introduce a set of three observables which are constructed from the unpolarized differential cross-section for the process $d\bar{u}\to W^{-}\gamma$ by appropriate convolution with a set of simple polynomials depending only on the center-of-mass angle. One of these observables allows for the direct determination of the anomalous coupling usually denoted by $\Delta\kappa$, without any simplifying assumptions, and without relying on the presence of a radiation zero. The other two observables impose two sum rules on the remaining three anomalous couplings. The inclusion of the structure functions is discussed in detail for both $p\bar{p}$ and $pp$ colliders. We show that, whilst for $p\bar{p}$ experiments this can be accomplished straightforwardly, in the $pp$ case one has to resort to somewhat more elaborate techniques, such as the binning of events according to their longitudinal momenta.
|
1012.3101
|
Zhiuo He
|
Zhi-Guo He, Xiao-Rui Lu, Joan Soto and Yangheng Zheng
|
The discrete contribution to $\psi^{\prime}\to J/\psi+\gamma\gamma$
|
19 pages, 5 figures, minor changes, references added, accepted
version in PRD
|
Phys.Rev.D83:054028,2011
|
10.1103/PhysRevD.83.054028
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The decay mode $\psi(2S)\to J/\psi+\gamma\gamma$ is proposed in order to
experimentally identify the effects of the coupling of charmonium states to the
continuum $D\bar D$ states. To have a better understanding of such a two-photon
decay process, in this work we restrict ourselves to investigate the
contribution of the discrete part, in which the photons are mainly produced via
the intermediate states $\chi_{cJ}(nP)$. Besides calculating the resonance
contributions of $\chi_{cJ}(1P)\; (J=0,1,2)$, we also take into account the
contributions of the higher excited states $\chi_{cJ}(2P)$ and the interference
effect among the 1P and 2P states. We find that the contribution of the 2P
states and the interference terms to the total decay width is very tiny.
However, for specific regions of the Dalitz plot, off the resonance peaks, we
find that these contributions are sizable and should also be accounted for. We
also provide the photon spectrum and study the polarization of $J/\psi$.
|
[
{
"created": "Tue, 14 Dec 2010 17:36:29 GMT",
"version": "v1"
},
{
"created": "Thu, 21 Apr 2011 15:44:45 GMT",
"version": "v2"
}
] |
2011-05-10
|
[
[
"He",
"Zhi-Guo",
""
],
[
"Lu",
"Xiao-Rui",
""
],
[
"Soto",
"Joan",
""
],
[
"Zheng",
"Yangheng",
""
]
] |
The decay mode $\psi(2S)\to J/\psi+\gamma\gamma$ is proposed in order to experimentally identify the effects of the coupling of charmonium states to the continuum $D\bar D$ states. To have a better understanding of such a two-photon decay process, in this work we restrict ourselves to investigate the contribution of the discrete part, in which the photons are mainly produced via the intermediate states $\chi_{cJ}(nP)$. Besides calculating the resonance contributions of $\chi_{cJ}(1P)\; (J=0,1,2)$, we also take into account the contributions of the higher excited states $\chi_{cJ}(2P)$ and the interference effect among the 1P and 2P states. We find that the contribution of the 2P states and the interference terms to the total decay width is very tiny. However, for specific regions of the Dalitz plot, off the resonance peaks, we find that these contributions are sizable and should also be accounted for. We also provide the photon spectrum and study the polarization of $J/\psi$.
|
1611.07010
|
C. Pallis
|
C. Pallis
|
Kinetically Modified Non-Minimal Inflation With Exponential Frame
Function
|
Minor revisions have been made; to appear in EPJC
| null |
10.1140/epjc/s10052-017-5165-2
| null |
hep-ph astro-ph.CO hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider Supersymmetric (SUSY) and non-SUSY models of chaotic inflation
based on the phi^n potential with n=2 or 4. We show that the coexistence of an
exponential nonminimal coupling to gravity, fR=Exp(cR phi^p), with a kinetic
mixing of the form fK=cK fR^m can accommodate inflationary observables favored
by the Planck and Bicep2/Keck Array results for p=1 and 2, 1<=m<=15 and
2.6x10^(-3)<=rRK=cR/cK^(p/2)<=1, where the upper limit is not imposed for p=1.
Inflation is of hilltop type and it can be attained for subplanckian inflaton
values with the corresponding effective theories retaining the perturbative
unitarity up to the Planck scale. The supergravity embedding of these models is
achieved employing two chiral gauge singlet supefields, a monomial
superpotential and several (semi)logarithmic or semipolynomial Kaehler
potentials.
|
[
{
"created": "Mon, 21 Nov 2016 20:56:40 GMT",
"version": "v1"
},
{
"created": "Fri, 1 Sep 2017 05:05:19 GMT",
"version": "v2"
}
] |
2017-10-25
|
[
[
"Pallis",
"C.",
""
]
] |
We consider Supersymmetric (SUSY) and non-SUSY models of chaotic inflation based on the phi^n potential with n=2 or 4. We show that the coexistence of an exponential nonminimal coupling to gravity, fR=Exp(cR phi^p), with a kinetic mixing of the form fK=cK fR^m can accommodate inflationary observables favored by the Planck and Bicep2/Keck Array results for p=1 and 2, 1<=m<=15 and 2.6x10^(-3)<=rRK=cR/cK^(p/2)<=1, where the upper limit is not imposed for p=1. Inflation is of hilltop type and it can be attained for subplanckian inflaton values with the corresponding effective theories retaining the perturbative unitarity up to the Planck scale. The supergravity embedding of these models is achieved employing two chiral gauge singlet supefields, a monomial superpotential and several (semi)logarithmic or semipolynomial Kaehler potentials.
|
hep-ph/9708450
|
D. N. Matsukevich
|
D. N. Matsukevich and O. N. Metelitsa
|
Radiative corrections to the differential decay rate of polarized
orthopositronium
|
7 pages, 1 Postscript figure, REVTeX3
| null | null | null |
hep-ph
| null |
The order - \alpha radiative corrections to the differential decay rate of
polarized orthopositronium are obtained. Their influences on the three photons
coincidence rate as a function of positronium polarization is considered.
|
[
{
"created": "Mon, 25 Aug 1997 14:58:18 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Matsukevich",
"D. N.",
""
],
[
"Metelitsa",
"O. N.",
""
]
] |
The order - \alpha radiative corrections to the differential decay rate of polarized orthopositronium are obtained. Their influences on the three photons coincidence rate as a function of positronium polarization is considered.
|
hep-ph/9209202
| null |
Y.N. Srivstava, A. Widom, M.H. Friedman, O.Panella
|
Compact Lattice QED and the Coulomb Potential
|
6 pages, includes one figure in Topdrawer, NUB 3054/92
|
Phys.Lett. B298 (1993) 405-408
|
10.1016/0370-2693(93)91841-A
| null |
hep-ph
| null |
The potential energy of a static charge distribution on a lattice is
rigorously computed in the standard compact quantum electrodynamic model. The
method used follows closely that of Weyl for ordinary quantum electrodynamics
in continuous space-time. The potential energy of the static charge
distribution is independent of temperature and can be calculated from the
lattice version of Poisson's equation. It is the usual Coulomb potential.
|
[
{
"created": "Tue, 1 Sep 1992 20:12:00 GMT",
"version": "v1"
}
] |
2009-10-22
|
[
[
"Srivstava",
"Y. N.",
""
],
[
"Widom",
"A.",
""
],
[
"Friedman",
"M. H.",
""
],
[
"Panella",
"O.",
""
]
] |
The potential energy of a static charge distribution on a lattice is rigorously computed in the standard compact quantum electrodynamic model. The method used follows closely that of Weyl for ordinary quantum electrodynamics in continuous space-time. The potential energy of the static charge distribution is independent of temperature and can be calculated from the lattice version of Poisson's equation. It is the usual Coulomb potential.
|
hep-ph/0001261
|
Reinhard Alkofer
|
M. Oettel and R. Alkofer
|
A Comparison between Relativistic and Semi-Relativistic Treatment in the
Diquark-Quark Model
|
12 pages,4 figures, 3 tables; minor modifications in text and tables,
references added, version to be published in Physics Letters B
|
Phys.Lett.B484:243-250,2000
|
10.1016/S0370-2693(00)00657-2
|
UNITUE--THEP-01/00
|
hep-ph nucl-th
| null |
In the diquark-quark model of the nucleon including scalar and axialvector
diquarks we compare solutions of the ladder Bethe-Salpeter equation in the
instantaneous Salpeter approximation and in the fully covariant (i.e.
four-dimensional) treatment. We obtain that the binding energy is severly
underestimated in the Salpeter approximation. For the electromagnetic form
factors of the nucleon we find that in both approaches the overall shapes of
the respective form factors are reasonably similar up to $Q^2 \approx 0.4$
GeV^2. However, the magnetic moments differ substantially as well as results
for the pion-nucleon and the axial coupling of the nucleon.
|
[
{
"created": "Tue, 25 Jan 2000 15:51:50 GMT",
"version": "v1"
},
{
"created": "Tue, 16 May 2000 08:45:16 GMT",
"version": "v2"
}
] |
2008-11-26
|
[
[
"Oettel",
"M.",
""
],
[
"Alkofer",
"R.",
""
]
] |
In the diquark-quark model of the nucleon including scalar and axialvector diquarks we compare solutions of the ladder Bethe-Salpeter equation in the instantaneous Salpeter approximation and in the fully covariant (i.e. four-dimensional) treatment. We obtain that the binding energy is severly underestimated in the Salpeter approximation. For the electromagnetic form factors of the nucleon we find that in both approaches the overall shapes of the respective form factors are reasonably similar up to $Q^2 \approx 0.4$ GeV^2. However, the magnetic moments differ substantially as well as results for the pion-nucleon and the axial coupling of the nucleon.
|
hep-ph/0608237
|
Chihiro Sasaki
|
M. Harada (Nagoya Univ.) and C. Sasaki (GSI)
|
Thermal Dilepton Production from Dropping rho based on the Vector
Manifestation
|
14 pages, 9 figures
|
Phys.Rev.D74:114006,2006
|
10.1103/PhysRevD.74.114006
| null |
hep-ph nucl-th
| null |
We study the pion electromagnetic form factor and the dilepton production
rate in hot matter using the hidden local symmetry theory as an effective field
theory for pions and rho mesons. In this framework, the chiral symmetry
restoration is realized as the vector manifestation (VM) in which the massless
vector meson becomes the chiral partner of the pion, giving a theoretical
support to the dropping rho a la Brown-Rho scaling. In the VM the vector
dominance (VD) is strongly violated near the phase transition point associated
with the dropping $\rho$. We show that the effect of the violation of the VD
substantially suppresses the dilepton production rate compared with the one
predicted by assuming the VD together with the dropping rho.
|
[
{
"created": "Mon, 21 Aug 2006 14:44:47 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Harada",
"M.",
"",
"Nagoya Univ."
],
[
"Sasaki",
"C.",
"",
"GSI"
]
] |
We study the pion electromagnetic form factor and the dilepton production rate in hot matter using the hidden local symmetry theory as an effective field theory for pions and rho mesons. In this framework, the chiral symmetry restoration is realized as the vector manifestation (VM) in which the massless vector meson becomes the chiral partner of the pion, giving a theoretical support to the dropping rho a la Brown-Rho scaling. In the VM the vector dominance (VD) is strongly violated near the phase transition point associated with the dropping $\rho$. We show that the effect of the violation of the VD substantially suppresses the dilepton production rate compared with the one predicted by assuming the VD together with the dropping rho.
|
1705.01469
|
Kei Yagyu
|
Tomohiro Abe, Ryosuke Sato, Kei Yagyu
|
Muon specific two-Higgs-doublet model
|
24 pages, 3 figures
| null |
10.1007/JHEP07(2017)012
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We investigate a new type of a two-Higgs-doublet model as a solution of the
muon $g-2$ anomaly. We impose a softly-broken $Z_4$ symmetry to forbid tree
level flavor changing neutral currents in a natural way. This $Z_4$ symmetry
restricts the structure of Yukawa couplings. As a result, extra Higgs boson
couplings to muons are enhanced by a factor of $\tan\beta$, while their
couplings to all the other standard model fermions are suppressed by
$\cot\beta$. Thanks to this coupling property, we can avoid the constraint from
leptonic $\tau$ decays in contrast to the lepton specific two-Higgs-doublet
model, which can explain the muon $g-2$ within the 2$\sigma$ level but cannot
within the $1\sigma$ level due to this constraint. We find that the model can
explain the muon $g-2$ within the 1$\sigma$ level satisfying constraints from
perturbative unitarity, vacuum stability, electroweak precision measurements,
and current LHC data.
|
[
{
"created": "Wed, 3 May 2017 14:51:24 GMT",
"version": "v1"
}
] |
2017-08-02
|
[
[
"Abe",
"Tomohiro",
""
],
[
"Sato",
"Ryosuke",
""
],
[
"Yagyu",
"Kei",
""
]
] |
We investigate a new type of a two-Higgs-doublet model as a solution of the muon $g-2$ anomaly. We impose a softly-broken $Z_4$ symmetry to forbid tree level flavor changing neutral currents in a natural way. This $Z_4$ symmetry restricts the structure of Yukawa couplings. As a result, extra Higgs boson couplings to muons are enhanced by a factor of $\tan\beta$, while their couplings to all the other standard model fermions are suppressed by $\cot\beta$. Thanks to this coupling property, we can avoid the constraint from leptonic $\tau$ decays in contrast to the lepton specific two-Higgs-doublet model, which can explain the muon $g-2$ within the 2$\sigma$ level but cannot within the $1\sigma$ level due to this constraint. We find that the model can explain the muon $g-2$ within the 1$\sigma$ level satisfying constraints from perturbative unitarity, vacuum stability, electroweak precision measurements, and current LHC data.
|
hep-ph/0012338
|
Valery Telnov
|
M.Galynskii (1), E.Kuraev (2), M.Levchuk (1), V.Telnov (3) ((1)IP,
Minsk, (2)JINR, Dubna, (3)INP, Novosibirsk)
|
Nonlinear effects in Compton scattering at photon colliders
|
21 pages, Latex, 6 figures(.ps), Talk at International Workshop on
High Energy Photon Colliders; June 14-17, 2000, DESY, Hamburg, Germany; to be
published in Nucl. Instr. and Methods A
|
Nucl.Instrum.Meth.A472:267-279,2001
|
10.1016/S0168-9002(01)01195-0
| null |
hep-ph physics.acc-ph physics.optics
| null |
The backward Compton scattering is a basic process at future higher energy
photon colliders. To obtain a high probability of e->gamma conversion the
density of laser photons in the conversion region should be so high that
simultaneous interaction of one electron with several laser photons is possible
(nonlinear Compton effect). In this paper a detailed consideration of energy
spectra, helicities of final photons and electrons in nonlinear backward
Compton scattering of circularly polarized laser photons is given.
Distributions of gamma-gamma luminosities with total helicities 0 and 2 are
investigated. Very high intensity of laser wave leads to broadening of the
energy (luminosity) spectra and shift to lower energies (invariant masses).
Beside complicated exact formulae, approximate formulae for energy spectrum and
polarization of backscattered photons are given for relatively small nonlinear
parameter xi^2 (first order correction). All this is necessary for optimization
of the conversion region at photon colliders and study of physics processes
where a sharp edge of the luminosity spectrum and monochromaticity of
collisions are important.
|
[
{
"created": "Mon, 25 Dec 2000 22:16:35 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Galynskii",
"M.",
""
],
[
"Kuraev",
"E.",
""
],
[
"Levchuk",
"M.",
""
],
[
"Telnov",
"V.",
""
]
] |
The backward Compton scattering is a basic process at future higher energy photon colliders. To obtain a high probability of e->gamma conversion the density of laser photons in the conversion region should be so high that simultaneous interaction of one electron with several laser photons is possible (nonlinear Compton effect). In this paper a detailed consideration of energy spectra, helicities of final photons and electrons in nonlinear backward Compton scattering of circularly polarized laser photons is given. Distributions of gamma-gamma luminosities with total helicities 0 and 2 are investigated. Very high intensity of laser wave leads to broadening of the energy (luminosity) spectra and shift to lower energies (invariant masses). Beside complicated exact formulae, approximate formulae for energy spectrum and polarization of backscattered photons are given for relatively small nonlinear parameter xi^2 (first order correction). All this is necessary for optimization of the conversion region at photon colliders and study of physics processes where a sharp edge of the luminosity spectrum and monochromaticity of collisions are important.
|
2209.13364
|
Jiang Yan
|
Jiang Yan, Zhi-Fei Wu, Jian-Ming Shen, Xing-Gang Wu
|
Precise perturbative predictions from fixed-order calculations
|
13 pages, 8 figures, to be published in J.Phys.G
| null |
10.1088/1361-6471/acb281
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The intrinsic conformality is a general property of the renormalizable gauge
theory, which ensures the scale-invariance of a fixed-order series at each
perturbative order. Following the idea of intrinsic conformality, we suggest a
novel single-scale setting approach under the principle of maximum conformality
(PMC) with the purpose of removing the conventional renormalization
scheme-and-scale ambiguities. We call this newly suggested single-scale
procedure as the PMC$_{\infty}$-s approach, in which an overall effective
$\alpha_s$, and hence an overall effective scale is achieved by identifying the
$\{\beta_0\}$-terms at each order. Its resultant conformal series is
scale-invariant and satisfies all renormalization group requirements. The
PMC$_{\infty}$-s approach is applicable to any perturbatively calculable
observables, and its resultant perturbative series provides an accurate basis
for estimating the contribution from the unknown higher-order (UHO) terms.
Using the Higgs decays into two gluons up to five-loop QCD corrections as an
example, we show how the PMC$_{\infty}$-s works, and we obtain $\Gamma_{\rm
H}\big|_{\text{PMC}_{\infty}\text{-s}}^{\rm PAA} = 334.45^{+7.07}_{-7.03}~{\rm
KeV}$ and $\Gamma_{\rm H}\big|_{\text{PMC}_{\infty}\text{-s}}^{\rm B.A.} =
334.45^{+6.34}_{-6.29}~{\rm KeV}$. Here the errors are squared averages of
those mentioned in the body of the text. The Pad$\acute{e}$ approximation
approach (PAA) and the Bayesian approach (B.A.) have been adopted to estimate
the contributions from the UHO-terms. We also demonstrate that the
PMC$_{\infty}$-s approach is equivalent to our previously suggested
single-scale setting approach (PMCs), which also follows from the PMC but
treats the $\{\beta_i\}$-terms from different point of view. Thus a proper
using of the renormalization group equation can provide a solid way to solve
the scale-setting problem.
|
[
{
"created": "Tue, 27 Sep 2022 13:12:20 GMT",
"version": "v1"
},
{
"created": "Thu, 12 Jan 2023 13:35:37 GMT",
"version": "v2"
}
] |
2023-03-01
|
[
[
"Yan",
"Jiang",
""
],
[
"Wu",
"Zhi-Fei",
""
],
[
"Shen",
"Jian-Ming",
""
],
[
"Wu",
"Xing-Gang",
""
]
] |
The intrinsic conformality is a general property of the renormalizable gauge theory, which ensures the scale-invariance of a fixed-order series at each perturbative order. Following the idea of intrinsic conformality, we suggest a novel single-scale setting approach under the principle of maximum conformality (PMC) with the purpose of removing the conventional renormalization scheme-and-scale ambiguities. We call this newly suggested single-scale procedure as the PMC$_{\infty}$-s approach, in which an overall effective $\alpha_s$, and hence an overall effective scale is achieved by identifying the $\{\beta_0\}$-terms at each order. Its resultant conformal series is scale-invariant and satisfies all renormalization group requirements. The PMC$_{\infty}$-s approach is applicable to any perturbatively calculable observables, and its resultant perturbative series provides an accurate basis for estimating the contribution from the unknown higher-order (UHO) terms. Using the Higgs decays into two gluons up to five-loop QCD corrections as an example, we show how the PMC$_{\infty}$-s works, and we obtain $\Gamma_{\rm H}\big|_{\text{PMC}_{\infty}\text{-s}}^{\rm PAA} = 334.45^{+7.07}_{-7.03}~{\rm KeV}$ and $\Gamma_{\rm H}\big|_{\text{PMC}_{\infty}\text{-s}}^{\rm B.A.} = 334.45^{+6.34}_{-6.29}~{\rm KeV}$. Here the errors are squared averages of those mentioned in the body of the text. The Pad$\acute{e}$ approximation approach (PAA) and the Bayesian approach (B.A.) have been adopted to estimate the contributions from the UHO-terms. We also demonstrate that the PMC$_{\infty}$-s approach is equivalent to our previously suggested single-scale setting approach (PMCs), which also follows from the PMC but treats the $\{\beta_i\}$-terms from different point of view. Thus a proper using of the renormalization group equation can provide a solid way to solve the scale-setting problem.
|
1801.06537
|
Ramona Gr\"ober
|
Mikael Chala, Ramona Gr\"ober and Michael Spannowsky
|
Searches for vector-like quarks at future colliders and implications for
composite Higgs models with dark matter
|
21 pages, 5 figures, updated to published JHEP version
|
JHEP 03 (2018) 040
|
10.1007/JHEP03(2018)040
|
IPPP/18/6
|
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Many composite Higgs models predict the existence of vector-like quarks with
masses outside the reach of the LHC, e.g. $m_Q \gtrsim 2$ TeV, in particular if
these models contain a dark matter candidate. In such models the mass of the
new resonances is bounded from above to satisfy the constraint from the
observed relic density. We therefore develop new strategies to search for
vector-like quarks at a future $100$ TeV collider and evaluate what masses and
interactions can be probed. We find that masses as large as $\sim 6.4$ ($\sim
9$) TeV can be tested if the fermionic resonances decay into Standard Model
(dark matter) particles. We also discuss the complementarity of dark matter
searches, showing that most of the parameter space can be closed. On balance,
this study motivates further the consideration of a higher-energy hadron
collider for a next generation of facilities.
|
[
{
"created": "Fri, 19 Jan 2018 18:57:07 GMT",
"version": "v1"
},
{
"created": "Tue, 13 Mar 2018 16:44:56 GMT",
"version": "v2"
}
] |
2018-04-04
|
[
[
"Chala",
"Mikael",
""
],
[
"Gröber",
"Ramona",
""
],
[
"Spannowsky",
"Michael",
""
]
] |
Many composite Higgs models predict the existence of vector-like quarks with masses outside the reach of the LHC, e.g. $m_Q \gtrsim 2$ TeV, in particular if these models contain a dark matter candidate. In such models the mass of the new resonances is bounded from above to satisfy the constraint from the observed relic density. We therefore develop new strategies to search for vector-like quarks at a future $100$ TeV collider and evaluate what masses and interactions can be probed. We find that masses as large as $\sim 6.4$ ($\sim 9$) TeV can be tested if the fermionic resonances decay into Standard Model (dark matter) particles. We also discuss the complementarity of dark matter searches, showing that most of the parameter space can be closed. On balance, this study motivates further the consideration of a higher-energy hadron collider for a next generation of facilities.
|
1406.5303
|
Joachim Kopp
|
Joachim Kopp (MPIK, Heidelberg and U of Mainz) and Marco Nardecchia (U
of Cambridge)
|
Flavor and CP violation in Higgs decays
|
17 pages, 5 figures
| null |
10.1007/JHEP10(2014)156
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Flavor violating interactions of the Higgs boson are a generic feature of
models with extended electroweak symmetry breaking sectors. Here, we
investigate CP violation in these interactions, which can arise from
interference of tree-level and 1-loop diagrams. We compute the CP asymmetry in
flavor violating Higgs decays in an effective field theory with only one Higgs
boson and in a general Type-III Two Higgs Doublet Model (2HDM). We find that
large (~ O(10%)) asymmetries are possible in the 2HDM if one of the extra Higgs
bosons has a mass similar to the Standard Model Higgs. For the poorly
constrained decay modes h -> tau mu and h -> tau e, this implies that large
lepton charge asymmetries could be detectable at the LHC. We quantify this by
comparing the sensitivity of the LHC to existing direct and indirect
constraints. Interestingly, detection prospects are best if Higgs mixing is
relatively small - a situation that is preferred by the current data.
Nevertheless, CP violation in h -> tau mu or h -> tau e will only be observable
if nonzero rates for these decay modes are measured very soon.
|
[
{
"created": "Fri, 20 Jun 2014 08:04:00 GMT",
"version": "v1"
}
] |
2015-06-22
|
[
[
"Kopp",
"Joachim",
"",
"MPIK, Heidelberg and U of Mainz"
],
[
"Nardecchia",
"Marco",
"",
"U\n of Cambridge"
]
] |
Flavor violating interactions of the Higgs boson are a generic feature of models with extended electroweak symmetry breaking sectors. Here, we investigate CP violation in these interactions, which can arise from interference of tree-level and 1-loop diagrams. We compute the CP asymmetry in flavor violating Higgs decays in an effective field theory with only one Higgs boson and in a general Type-III Two Higgs Doublet Model (2HDM). We find that large (~ O(10%)) asymmetries are possible in the 2HDM if one of the extra Higgs bosons has a mass similar to the Standard Model Higgs. For the poorly constrained decay modes h -> tau mu and h -> tau e, this implies that large lepton charge asymmetries could be detectable at the LHC. We quantify this by comparing the sensitivity of the LHC to existing direct and indirect constraints. Interestingly, detection prospects are best if Higgs mixing is relatively small - a situation that is preferred by the current data. Nevertheless, CP violation in h -> tau mu or h -> tau e will only be observable if nonzero rates for these decay modes are measured very soon.
|
hep-ph/0505149
|
Osamu Seto
|
Edmund J. Copeland and Osamu Seto
|
Reheating and gravitino production in braneworld inflation
|
24pages
|
Phys.Rev. D72 (2005) 023506
|
10.1103/PhysRevD.72.023506
| null |
hep-ph astro-ph hep-th
| null |
We consider the constraints that can be imposed on a wide class of Inflation
models in modified gravity scenarios in which the Friedmann equation is
modified by the inclusion of $\rho^2$ terms, where $\rho$ is the total energy
density. In particular we obtain the reheating temperature and gravitino
abundance associated with the end of inflation. Whereas models of chaotic
inflation and natural inflation can easily avoid the conventional gravitino
overproduction problem, we show that supersymmetric hybrid inflation models
(driven by both F and D-terms) do not work in the $\rho^2$ dominated era. We
also study inflation driven by exponetial potentials in this modified
background, and show that the gravitino production is suppressed enough to
avoid there being a problem, although other conditions severely constrain these
models.
|
[
{
"created": "Tue, 17 May 2005 09:15:20 GMT",
"version": "v1"
},
{
"created": "Tue, 19 Jul 2005 17:24:27 GMT",
"version": "v2"
}
] |
2009-11-11
|
[
[
"Copeland",
"Edmund J.",
""
],
[
"Seto",
"Osamu",
""
]
] |
We consider the constraints that can be imposed on a wide class of Inflation models in modified gravity scenarios in which the Friedmann equation is modified by the inclusion of $\rho^2$ terms, where $\rho$ is the total energy density. In particular we obtain the reheating temperature and gravitino abundance associated with the end of inflation. Whereas models of chaotic inflation and natural inflation can easily avoid the conventional gravitino overproduction problem, we show that supersymmetric hybrid inflation models (driven by both F and D-terms) do not work in the $\rho^2$ dominated era. We also study inflation driven by exponetial potentials in this modified background, and show that the gravitino production is suppressed enough to avoid there being a problem, although other conditions severely constrain these models.
|
2008.08484
|
Yunhua Ding
|
Yunhua Ding and Mohammad Farhan Rawnak
|
Lorentz and CPT tests with charge-to-mass ratio comparisons in Penning
traps
|
accepted in Phys. Rev. D
|
Phys. Rev. D 102, 056009 (2020)
|
10.1103/PhysRevD.102.056009
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Applications of the general theory of quantum electrodynamics with Lorentz-
and CPT-violating operators of mass dimensions up to six are presented to
Penning-trap experiments comparing charge-to-mass ratios between particles and
antiparticles. Perturbation theory is used to derive Lorentz- and CPT-violating
contributions to the energy levels and cyclotron frequencies of confined
particles and antiparticles. We show that whether the experimental {\it
interpreted} quantity $(|q|/m)_{\overline{w}}/(|q|/m)_{w} - 1$ is a clean
measure of a CPT test depends on the context of the relevant theory. Existing
experimental results of charge-to-mass ratio comparisons are used to obtain
first-time constraints on 69 coefficients for Lorentz and CPT violation.
|
[
{
"created": "Wed, 19 Aug 2020 14:54:44 GMT",
"version": "v1"
}
] |
2020-09-16
|
[
[
"Ding",
"Yunhua",
""
],
[
"Rawnak",
"Mohammad Farhan",
""
]
] |
Applications of the general theory of quantum electrodynamics with Lorentz- and CPT-violating operators of mass dimensions up to six are presented to Penning-trap experiments comparing charge-to-mass ratios between particles and antiparticles. Perturbation theory is used to derive Lorentz- and CPT-violating contributions to the energy levels and cyclotron frequencies of confined particles and antiparticles. We show that whether the experimental {\it interpreted} quantity $(|q|/m)_{\overline{w}}/(|q|/m)_{w} - 1$ is a clean measure of a CPT test depends on the context of the relevant theory. Existing experimental results of charge-to-mass ratio comparisons are used to obtain first-time constraints on 69 coefficients for Lorentz and CPT violation.
|
1512.06437
|
Dorota Sokolowska
|
Maria Krawczyk, Neda Darvishi, Dorota Sokolowska
|
The Inert Doublet Model and its extensions
|
Presented at Zakopane School 2015 by M. Krawczyk and N. Darvishi; v2:
Updated references
| null |
10.5506/APhysPolB.47.183
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The Inert Doublet Model and its extension with an additional complex singlet
is considered. The CP violation aspects are analysed in the simplified case,
with one SM-like Higgs doublet and a complex singlet.
|
[
{
"created": "Sun, 20 Dec 2015 21:25:15 GMT",
"version": "v1"
},
{
"created": "Sat, 26 Dec 2015 07:51:40 GMT",
"version": "v2"
}
] |
2016-04-20
|
[
[
"Krawczyk",
"Maria",
""
],
[
"Darvishi",
"Neda",
""
],
[
"Sokolowska",
"Dorota",
""
]
] |
The Inert Doublet Model and its extension with an additional complex singlet is considered. The CP violation aspects are analysed in the simplified case, with one SM-like Higgs doublet and a complex singlet.
|
hep-ph/0303227
|
Morimitsu Tanimoto
|
Mizue Honda, Satoru Kaneko, Morimitsu Tanimoto
|
Prediction of $U_{e3}$ in Neutrino Mass Matrix with Two Zeros
|
Figures and discussions are added
|
JHEP 0309 (2003) 028
|
10.1088/1126-6708/2003/09/028
| null |
hep-ph
| null |
We have discussed predictions of $|U_{e3}|$ and $J_{CP}$ in the framework of
the neutrino mass matrix with two zeros. In the case of the best fit values of
$\tan^2\theta_{12}$, $\tan^2\theta_{23}$, $\Delta m^2_{\rm sun}$ and $\Delta
m_{\rm atm}^2$, the prediction of $|U_{e3}|$ is $0.11\sim 0.14$. The lower
bound of $|U_{e3}|$ is 0.05, which depends on $\tan\theta_{12}$ and
$\tan\theta_{23}$. We have investigated the stability of these predictions
taking account of small corrections to zeros, which may come from radiative
corrections or off-diagonal elements of the charged lepton massmatrix.
The lower bound of $|U_{e3}|$ comes down considerably due to the small
corrections to zeros.
|
[
{
"created": "Thu, 27 Mar 2003 02:39:45 GMT",
"version": "v1"
},
{
"created": "Sun, 11 May 2003 06:06:58 GMT",
"version": "v2"
},
{
"created": "Sun, 15 Jun 2003 07:34:40 GMT",
"version": "v3"
},
{
"created": "Sun, 6 Jul 2003 09:46:27 GMT",
"version": "v4"
},
{
"created": "Sat, 27 Sep 2003 07:28:30 GMT",
"version": "v5"
}
] |
2009-11-10
|
[
[
"Honda",
"Mizue",
""
],
[
"Kaneko",
"Satoru",
""
],
[
"Tanimoto",
"Morimitsu",
""
]
] |
We have discussed predictions of $|U_{e3}|$ and $J_{CP}$ in the framework of the neutrino mass matrix with two zeros. In the case of the best fit values of $\tan^2\theta_{12}$, $\tan^2\theta_{23}$, $\Delta m^2_{\rm sun}$ and $\Delta m_{\rm atm}^2$, the prediction of $|U_{e3}|$ is $0.11\sim 0.14$. The lower bound of $|U_{e3}|$ is 0.05, which depends on $\tan\theta_{12}$ and $\tan\theta_{23}$. We have investigated the stability of these predictions taking account of small corrections to zeros, which may come from radiative corrections or off-diagonal elements of the charged lepton massmatrix. The lower bound of $|U_{e3}|$ comes down considerably due to the small corrections to zeros.
|
2111.14788
|
Ibrahim Chahrour
|
Ibrahim Chahrour and James D. Wells
|
Comparing Machine Learning and Interpolation Methods for Loop-Level
Calculations
|
30 pages, 17 figures, v2:added a few references, v3: new title, added
a few references
|
SciPost Phys. 12, 187 (2022)
|
10.21468/SciPostPhys.12.6.187
| null |
hep-ph cs.LG
|
http://creativecommons.org/licenses/by/4.0/
|
The need to approximate functions is ubiquitous in science, either due to
empirical constraints or high computational cost of accessing the function. In
high-energy physics, the precise computation of the scattering cross-section of
a process requires the evaluation of computationally intensive integrals. A
wide variety of methods in machine learning have been used to tackle this
problem, but often the motivation of using one method over another is lacking.
Comparing these methods is typically highly dependent on the problem at hand,
so we specify to the case where we can evaluate the function a large number of
times, after which quick and accurate evaluation can take place. We consider
four interpolation and three machine learning techniques and compare their
performance on three toy functions, the four-point scalar Passarino-Veltman
$D_0$ function, and the two-loop self-energy master integral $M$. We find that
in low dimensions ($d = 3$), traditional interpolation techniques like the
Radial Basis Function perform very well, but in higher dimensions ($d=5, 6, 9$)
we find that multi-layer perceptrons (a.k.a neural networks) do not suffer as
much from the curse of dimensionality and provide the fastest and most accurate
predictions.
|
[
{
"created": "Mon, 29 Nov 2021 18:43:57 GMT",
"version": "v1"
},
{
"created": "Wed, 8 Dec 2021 19:12:47 GMT",
"version": "v2"
},
{
"created": "Mon, 28 Mar 2022 20:50:41 GMT",
"version": "v3"
}
] |
2022-06-08
|
[
[
"Chahrour",
"Ibrahim",
""
],
[
"Wells",
"James D.",
""
]
] |
The need to approximate functions is ubiquitous in science, either due to empirical constraints or high computational cost of accessing the function. In high-energy physics, the precise computation of the scattering cross-section of a process requires the evaluation of computationally intensive integrals. A wide variety of methods in machine learning have been used to tackle this problem, but often the motivation of using one method over another is lacking. Comparing these methods is typically highly dependent on the problem at hand, so we specify to the case where we can evaluate the function a large number of times, after which quick and accurate evaluation can take place. We consider four interpolation and three machine learning techniques and compare their performance on three toy functions, the four-point scalar Passarino-Veltman $D_0$ function, and the two-loop self-energy master integral $M$. We find that in low dimensions ($d = 3$), traditional interpolation techniques like the Radial Basis Function perform very well, but in higher dimensions ($d=5, 6, 9$) we find that multi-layer perceptrons (a.k.a neural networks) do not suffer as much from the curse of dimensionality and provide the fastest and most accurate predictions.
|
1606.04403
|
Luke Pickering
|
Luke Pickering, Xianguo Lu
|
Theoretical predictions of transverse kinematic imbalance in
neutrino-nucleus interactions
|
5 pages, 9 figures, NuPhys 2015 poster session proceedings
| null | null | null |
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Distributions of transverse kinematic imbalance in neutrino-nucleus
interactions in the few GeV regime are sensitive to nuclear effects. We present
a study comparing the latest predictions of transverse kinematic imbalance from
the interaction simulations, NuWro and GENIE. We dis- cuss the differences
between the model predictions.
|
[
{
"created": "Mon, 13 Jun 2016 09:32:53 GMT",
"version": "v1"
}
] |
2016-06-15
|
[
[
"Pickering",
"Luke",
""
],
[
"Lu",
"Xianguo",
""
]
] |
Distributions of transverse kinematic imbalance in neutrino-nucleus interactions in the few GeV regime are sensitive to nuclear effects. We present a study comparing the latest predictions of transverse kinematic imbalance from the interaction simulations, NuWro and GENIE. We dis- cuss the differences between the model predictions.
|
1709.08564
|
Stefan Dittmaier
|
Stefan Dittmaier
|
Standard Model Theory
|
10 pages, 8 figures, latex, to appear in the Proceedings of the EPS
Conference on High Energy Physics (EPS-HEP), Venice, July 2017, reference
added
| null | null |
FR-PHENO-2017-017
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The field of precision calculations for Standard Model processes at the LHC
has experienced enormous progress in recent years. This talk highlights some
examples from the physics of parton distribution functions, jets, electroweak
gauge bosons and Higgs bosons.
|
[
{
"created": "Mon, 25 Sep 2017 15:54:49 GMT",
"version": "v1"
},
{
"created": "Wed, 27 Sep 2017 15:05:17 GMT",
"version": "v2"
}
] |
2017-09-28
|
[
[
"Dittmaier",
"Stefan",
""
]
] |
The field of precision calculations for Standard Model processes at the LHC has experienced enormous progress in recent years. This talk highlights some examples from the physics of parton distribution functions, jets, electroweak gauge bosons and Higgs bosons.
|
1912.08911
|
Gerald A. Miller
|
Gerald A. Miller and Stanley J. Brodsky
|
The Frame-Independent Spatial Coordinate $\tilde{z}$: Implications for
Light-Front Wave Functions, Deep Inelastic Scattering, Light-Front
Holography, and Lattice QCD Calculations
|
6 pages, 6 figures, this version adds references, corrects a
typographical error and contains more explanations regarding the use of the
variable $\tilde z$
|
Phys. Rev. C 102, 022201 (2020)
|
10.1103/PhysRevC.102.022201
|
NT@UW-19-20
|
hep-ph hep-lat nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
A general procedure for obtaining frame-independent, three-dimensional
light-front coordinate-space wave functions is introduced. The third spatial
coordinate, $\tilde z$ , is the frame independent coordinate conjugate to the
light-front momentum coordinate $x={k^+\over P^+}$ which appears in the
momentum-space light-front wave functions underlying generalized parton
distributions, structure functions, distribution amplitudes, form factors, and
other hadronic observables. These causal light-front coordinate-space wave
functions are used to derive a general expression for the quark distribution
function of hadrons as an integral over the frame-independent longitudinal
distance (the Ioffe time) between virtual-photon absorption and emission
appearing in the forward virtual photon-hadron Compton scattering amplitude.
Specific examples using models derived from light-front holographic QCD show
that the spatial extent of the proton eigenfunction in the longitudinal
direction can have very large extent in $\tilde z$.
|
[
{
"created": "Wed, 18 Dec 2019 22:05:51 GMT",
"version": "v1"
},
{
"created": "Mon, 23 Dec 2019 20:34:50 GMT",
"version": "v2"
},
{
"created": "Fri, 3 Jan 2020 18:40:39 GMT",
"version": "v3"
},
{
"created": "Mon, 27 Apr 2020 17:34:28 GMT",
"version": "v4"
}
] |
2020-08-12
|
[
[
"Miller",
"Gerald A.",
""
],
[
"Brodsky",
"Stanley J.",
""
]
] |
A general procedure for obtaining frame-independent, three-dimensional light-front coordinate-space wave functions is introduced. The third spatial coordinate, $\tilde z$ , is the frame independent coordinate conjugate to the light-front momentum coordinate $x={k^+\over P^+}$ which appears in the momentum-space light-front wave functions underlying generalized parton distributions, structure functions, distribution amplitudes, form factors, and other hadronic observables. These causal light-front coordinate-space wave functions are used to derive a general expression for the quark distribution function of hadrons as an integral over the frame-independent longitudinal distance (the Ioffe time) between virtual-photon absorption and emission appearing in the forward virtual photon-hadron Compton scattering amplitude. Specific examples using models derived from light-front holographic QCD show that the spatial extent of the proton eigenfunction in the longitudinal direction can have very large extent in $\tilde z$.
|
1807.08749
|
James Cline
|
James M. Cline
|
TASI Lectures on Early Universe Cosmology: Inflation, Baryogenesis and
Dark Matter
|
52 pages, 29 figures. v2: added references; v3+: fixed numerous typos
and errors; v5: corrected equations for anomalous B violation
| null | null | null |
hep-ph astro-ph.CO
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
These lectures, presented at TASI 2018, provide a concise introduction to
inflation, baryogenesis, and aspects of dark matter not covered by the other
lectures. The emphasis for inflation is an intuitive understanding and
techniques for constraining inflationary models. For baryogenesis we focus on
two examples, leptogenesis and electroweak baryogenesis, with attention to
singlet-assisted two-step phase transitions. Concerning dark matter, we review
different classes of models distinguished by their mechanisms for obtaining the
observed relic density, including thermal freeze-out, asymmetric dark matter,
freeze-in, SIMP dark matter, the misalignment mechanism for ultralight scalars
and axions, and production of primordial black holes during inflation. Problem
sets are provided.
|
[
{
"created": "Mon, 23 Jul 2018 17:56:48 GMT",
"version": "v1"
},
{
"created": "Mon, 30 Jul 2018 16:06:43 GMT",
"version": "v2"
},
{
"created": "Sat, 29 Dec 2018 23:13:33 GMT",
"version": "v3"
},
{
"created": "Fri, 21 Jun 2019 20:33:01 GMT",
"version": "v4"
},
{
"created": "Tue, 20 Jul 2021 13:40:41 GMT",
"version": "v5"
},
{
"created": "Mon, 2 Aug 2021 11:23:06 GMT",
"version": "v6"
}
] |
2021-08-03
|
[
[
"Cline",
"James M.",
""
]
] |
These lectures, presented at TASI 2018, provide a concise introduction to inflation, baryogenesis, and aspects of dark matter not covered by the other lectures. The emphasis for inflation is an intuitive understanding and techniques for constraining inflationary models. For baryogenesis we focus on two examples, leptogenesis and electroweak baryogenesis, with attention to singlet-assisted two-step phase transitions. Concerning dark matter, we review different classes of models distinguished by their mechanisms for obtaining the observed relic density, including thermal freeze-out, asymmetric dark matter, freeze-in, SIMP dark matter, the misalignment mechanism for ultralight scalars and axions, and production of primordial black holes during inflation. Problem sets are provided.
|
1805.08940
|
Kouji Kashiwa
|
Kouji Kashiwa, Yuto Mori, Akira Ohnishi
|
Control the model sign problem via path optimization method: Monte-Carlo
approach to QCD effective model with Polyakov loop
|
7 pages, 6 figures, typo corrected
|
Phys. Rev. D 99, 014033 (2019)
|
10.1103/PhysRevD.99.014033
|
YITP-18-43, KUNS-2724
|
hep-ph hep-lat hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We apply the path optimization method to a QCD effective model with the
Polyakov loop at finite density to circumvent the model sign problem. The
Polyakov-loop extended Nambu--Jona-Lasinio model is employed as the typical QCD
effective model and then the hybrid Monte-Carlo method is used to perform the
path integration. To control the sign problem, the path optimization method is
used with complexification of temporal gluon fields to modify the integral path
in the complex space. We show that the average phase factor is well improved on
the modified integral-path compared with that on the original one. This
indicates that the complexification of temporal gluon fields may be enough to
control the sign problem of QCD in the path optimization method.
|
[
{
"created": "Wed, 23 May 2018 02:44:47 GMT",
"version": "v1"
},
{
"created": "Tue, 29 May 2018 00:07:57 GMT",
"version": "v2"
}
] |
2019-01-30
|
[
[
"Kashiwa",
"Kouji",
""
],
[
"Mori",
"Yuto",
""
],
[
"Ohnishi",
"Akira",
""
]
] |
We apply the path optimization method to a QCD effective model with the Polyakov loop at finite density to circumvent the model sign problem. The Polyakov-loop extended Nambu--Jona-Lasinio model is employed as the typical QCD effective model and then the hybrid Monte-Carlo method is used to perform the path integration. To control the sign problem, the path optimization method is used with complexification of temporal gluon fields to modify the integral path in the complex space. We show that the average phase factor is well improved on the modified integral-path compared with that on the original one. This indicates that the complexification of temporal gluon fields may be enough to control the sign problem of QCD in the path optimization method.
|
2302.11852
|
Khumanthem Helensana Devi
|
Kh. Helensana Devi, K. Sashikanta Singh, and N.Nimai Singh
|
Stability of the next-to-tribimaximal mixings under radiative
corrections with the variation of SUSY breaking scale in MSSM
|
35 pages,32 figures
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We analyse the radiative stability of the next-to-tribimaximal mixings
($NTBM$) with the variation of SUSY breaking scale ($m_S$) in MSSM, for both
normal ordering (NO) and inverted ordering (IO) at the fixed input value of
seesaw scale $M_R = 10^{15}$ GeV and two different values of $\tan \beta$. All
the neutrino oscillation parameters receive varying radiative corrections
irrespective of the $m_S$ values at the electroweak scale, which are all within
$3\sigma$ range of the latest global fit data at low value of $\tan \beta$
(30). NO is found to be more stable than IO for all four different NTBM mixing
patterns.
|
[
{
"created": "Thu, 23 Feb 2023 08:36:19 GMT",
"version": "v1"
},
{
"created": "Thu, 2 Nov 2023 10:20:45 GMT",
"version": "v2"
}
] |
2023-11-03
|
[
[
"Devi",
"Kh. Helensana",
""
],
[
"Singh",
"K. Sashikanta",
""
],
[
"Singh",
"N. Nimai",
""
]
] |
We analyse the radiative stability of the next-to-tribimaximal mixings ($NTBM$) with the variation of SUSY breaking scale ($m_S$) in MSSM, for both normal ordering (NO) and inverted ordering (IO) at the fixed input value of seesaw scale $M_R = 10^{15}$ GeV and two different values of $\tan \beta$. All the neutrino oscillation parameters receive varying radiative corrections irrespective of the $m_S$ values at the electroweak scale, which are all within $3\sigma$ range of the latest global fit data at low value of $\tan \beta$ (30). NO is found to be more stable than IO for all four different NTBM mixing patterns.
|
1402.3002
|
Kenji Fukushima
|
Kenji Fukushima
|
Spectral representation of the particle production out of equilibrium -
Schwinger mechanism in pulsed electric fields
|
15 pages, 5 figures
| null |
10.1088/1367-2630/16/7/073031
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We develop a formalism to describe the particle production out of equilibrium
in terms of dynamical spectral functions, i.e. Wigner transformed
Pauli-Jordan's and Hadamard's functions. We take an explicit example of a
spatially homogeneous scalar theory under pulsed electric fields and
investigate the time evolution of the spectral functions. In the out-state we
find an oscillatory peak in Hadamard's function as a result of the mixing
between positive- and negative-energy waves. The strength of this peak is of
the linear order of the Bogoliubov mixing coefficient, whereas the peak
corresponding to the Schwinger mechanism is of the quadratic order. Between the
in- and the out-states we observe a continuous flow of the spectral peaks
together with two transient oscillatory peaks. We also discuss the medium
effect at finite temperature and density. We emphasise that the entire
structure of the spectral functions conveys rich information on real-time
dynamics including the particle production.
|
[
{
"created": "Wed, 12 Feb 2014 22:51:35 GMT",
"version": "v1"
}
] |
2015-06-18
|
[
[
"Fukushima",
"Kenji",
""
]
] |
We develop a formalism to describe the particle production out of equilibrium in terms of dynamical spectral functions, i.e. Wigner transformed Pauli-Jordan's and Hadamard's functions. We take an explicit example of a spatially homogeneous scalar theory under pulsed electric fields and investigate the time evolution of the spectral functions. In the out-state we find an oscillatory peak in Hadamard's function as a result of the mixing between positive- and negative-energy waves. The strength of this peak is of the linear order of the Bogoliubov mixing coefficient, whereas the peak corresponding to the Schwinger mechanism is of the quadratic order. Between the in- and the out-states we observe a continuous flow of the spectral peaks together with two transient oscillatory peaks. We also discuss the medium effect at finite temperature and density. We emphasise that the entire structure of the spectral functions conveys rich information on real-time dynamics including the particle production.
|
1802.09997
|
Alejandro Ibarra
|
Alejandro Ibarra, Patrick Strobl, Takashi Toma
|
Neutrino masses from Planck-scale lepton number breaking
|
5 pages, 2 figures. Matches published version
|
Phys. Rev. Lett. 122, 081803 (2019)
|
10.1103/PhysRevLett.122.081803
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider an extension of the Standard Model by right-handed neutrinos and
we argue that, under plausible assumptions, a neutrino mass of ${\cal
O}(0.1)\,{\rm eV}$ is naturally generated by the breaking of the lepton number
at the Planck scale, possibly by gravitational effects, without the necessity
of introducing new mass scales in the model. Some implications of this
framework are also briefly discussed.
|
[
{
"created": "Tue, 27 Feb 2018 16:14:12 GMT",
"version": "v1"
},
{
"created": "Fri, 22 Feb 2019 01:51:45 GMT",
"version": "v2"
}
] |
2019-03-06
|
[
[
"Ibarra",
"Alejandro",
""
],
[
"Strobl",
"Patrick",
""
],
[
"Toma",
"Takashi",
""
]
] |
We consider an extension of the Standard Model by right-handed neutrinos and we argue that, under plausible assumptions, a neutrino mass of ${\cal O}(0.1)\,{\rm eV}$ is naturally generated by the breaking of the lepton number at the Planck scale, possibly by gravitational effects, without the necessity of introducing new mass scales in the model. Some implications of this framework are also briefly discussed.
|
hep-ph/0008336
|
Bhaskar Dutta
|
R. Arnowitt, B. Dutta and Y. Santoso
|
Maximum And Minimum Dark Matter Detection Cross Sections
|
11 pages, latex, 8 figures, based on invited talk at Workshop on the
Next Generation U.S. Underground Facility, Carlsbad, NM, June, 2000
| null | null | null |
hep-ph
| null |
The range of neutralino-proton cross sections for R-parity preserving
supergravity models with GUT scale unification of the gauge coupling constants
is examined. The models considered here are mSUGRA, models with non universal
soft breaking and D-brane models. It is found that the current dark matter
detectors are sampling significant parts of the SUSY parameter space and future
detectors could sample almost the entire space. The special regions of
parameter space that may be inaccessible to future detectors are seen to have a
squark/gluino spectra beyond 1 TeV, but observable at the LHC.
|
[
{
"created": "Thu, 31 Aug 2000 19:20:06 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Arnowitt",
"R.",
""
],
[
"Dutta",
"B.",
""
],
[
"Santoso",
"Y.",
""
]
] |
The range of neutralino-proton cross sections for R-parity preserving supergravity models with GUT scale unification of the gauge coupling constants is examined. The models considered here are mSUGRA, models with non universal soft breaking and D-brane models. It is found that the current dark matter detectors are sampling significant parts of the SUSY parameter space and future detectors could sample almost the entire space. The special regions of parameter space that may be inaccessible to future detectors are seen to have a squark/gluino spectra beyond 1 TeV, but observable at the LHC.
|
hep-ph/0308024
|
Kiwoon Choi
|
Kiwoon Choi
|
A QCD Axion from Higher Dimensional Gauge Field
|
5 pages, Revtex4
|
Phys.Rev.Lett. 92 (2004) 101602
|
10.1103/PhysRevLett.92.101602
|
KAIST-TH 2003/07
|
hep-ph
| null |
We point out that a QCD axion solving the strong CP problem can arise
naturally from parity-odd gauge field C_M in 5-dimensional (5D) orbifold field
theory. The required axion coupling to the QCD anomaly comes from the 5D
Chern-Simons coupling, and all other unwanted U(1)_{PQ} breaking axion
couplings can be avoided naturally by the 5D gauge symmetry of C_M and the 5D
locality. If the fifth dimension is warped, the resulting axion scale is
suppressed by small warp factor compared to the Planck scale, thereby the model
can generate naturally an intermediate axion scale f_a=10^{10} - 10^{12}GeV.
|
[
{
"created": "Mon, 4 Aug 2003 08:59:14 GMT",
"version": "v1"
}
] |
2009-11-10
|
[
[
"Choi",
"Kiwoon",
""
]
] |
We point out that a QCD axion solving the strong CP problem can arise naturally from parity-odd gauge field C_M in 5-dimensional (5D) orbifold field theory. The required axion coupling to the QCD anomaly comes from the 5D Chern-Simons coupling, and all other unwanted U(1)_{PQ} breaking axion couplings can be avoided naturally by the 5D gauge symmetry of C_M and the 5D locality. If the fifth dimension is warped, the resulting axion scale is suppressed by small warp factor compared to the Planck scale, thereby the model can generate naturally an intermediate axion scale f_a=10^{10} - 10^{12}GeV.
|
hep-ph/0306084
|
Haim Goldberg
|
Luis Anchordoqui and Haim Goldberg
|
Time Variation of the Fine Structure Constant Driven by Quintessence
|
Final version, to be published in Phys Rev D
|
Phys.Rev. D68 (2003) 083513
|
10.1103/PhysRevD.68.083513
|
NUB-3237-TH-03, MIT-CTP-3385
|
hep-ph astro-ph gr-qc hep-th
| null |
There are indications from the study of quasar absorption spectra that the
fine structure constant $\alpha$ may have been measurably smaller for redshifts
$z>2.$ Analyses of other data ($^{149}$Sm fission rate for the Oklo natural
reactor, variation of $^{187}$Re $\beta$-decay rate in meteorite studies,
atomic clock measurements) which probe variations of $\alpha$ in the more
recent past imply much smaller deviations from its present value. In this work
we tie the variation of $\alpha$ to the evolution of the quintessence field
proposed by Albrecht and Skordis, and show that agreement with all these data,
as well as consistency with WMAP observations, can be achieved for a range of
parameters. Some definite predictions follow for upcoming space missions
searching for violations of the equivalence principle.
|
[
{
"created": "Wed, 11 Jun 2003 14:28:15 GMT",
"version": "v1"
},
{
"created": "Thu, 19 Jun 2003 15:40:21 GMT",
"version": "v2"
},
{
"created": "Thu, 4 Sep 2003 14:21:01 GMT",
"version": "v3"
}
] |
2009-11-10
|
[
[
"Anchordoqui",
"Luis",
""
],
[
"Goldberg",
"Haim",
""
]
] |
There are indications from the study of quasar absorption spectra that the fine structure constant $\alpha$ may have been measurably smaller for redshifts $z>2.$ Analyses of other data ($^{149}$Sm fission rate for the Oklo natural reactor, variation of $^{187}$Re $\beta$-decay rate in meteorite studies, atomic clock measurements) which probe variations of $\alpha$ in the more recent past imply much smaller deviations from its present value. In this work we tie the variation of $\alpha$ to the evolution of the quintessence field proposed by Albrecht and Skordis, and show that agreement with all these data, as well as consistency with WMAP observations, can be achieved for a range of parameters. Some definite predictions follow for upcoming space missions searching for violations of the equivalence principle.
|
1704.04111
|
Zhi-Gang Wang
|
Zhi-Gang Wang
|
Analysis of the mass and width of the $X^*(3860)$ with QCD sum rules
|
12 pages, 6 figures
|
Eur. Phys. J. A53 (2017) 192
|
10.1140/epja/i2017-12390-6
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In this article, we tentatively assign the $X^*(3860)$ to be the
$C\gamma_5\otimes \gamma_5C$ type scalar tetraquark state, study its mass and
width with the QCD sum rules, special attention is paid to calculating the
hadronic coupling constants $G_{X\eta_c\pi}$ and $G_{XDD}$ concerning the
tetraquark state. We obtain the values $M_{X}=3.86 \pm 0.09\,\rm{GeV}$ and
$\Gamma_{X}= 202\pm 146 \,\rm{MeV}$, which are consistent with the experimental
data. The numerical result supports assigning the $X^*(3860)$ to be the
$C\gamma_5\otimes \gamma_5C$ type scalar tetraquark state.
|
[
{
"created": "Thu, 13 Apr 2017 13:13:44 GMT",
"version": "v1"
},
{
"created": "Sat, 27 May 2017 08:00:30 GMT",
"version": "v2"
},
{
"created": "Fri, 25 Aug 2017 08:30:30 GMT",
"version": "v3"
}
] |
2017-10-05
|
[
[
"Wang",
"Zhi-Gang",
""
]
] |
In this article, we tentatively assign the $X^*(3860)$ to be the $C\gamma_5\otimes \gamma_5C$ type scalar tetraquark state, study its mass and width with the QCD sum rules, special attention is paid to calculating the hadronic coupling constants $G_{X\eta_c\pi}$ and $G_{XDD}$ concerning the tetraquark state. We obtain the values $M_{X}=3.86 \pm 0.09\,\rm{GeV}$ and $\Gamma_{X}= 202\pm 146 \,\rm{MeV}$, which are consistent with the experimental data. The numerical result supports assigning the $X^*(3860)$ to be the $C\gamma_5\otimes \gamma_5C$ type scalar tetraquark state.
|
1910.04660
|
M\'at\'e Csan\'ad
|
Mate Csanad, Marton I. Nagy, Ze-Fang Jiang, Tamas Csorgo
|
New solutions of viscous relativistic hydrodynamics
|
6 pages, 1 figure. Presented at the XIV Workshop on Particle
Correlations and Femtoscopy, June 3-7, 2019, Dubna, Russia
|
Phys. Part. Nuclei 51, 274-277 (2020)
|
10.1134/S1063779620030090
| null |
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Relativistic hydrodynamics represents a powerful tool to investigate the time
evolution of the strongly interacting quark gluon plasma created in
ultrarelativistic heavy ion collisions. The equations are solved often
numerically, and numerous analytic solutions also exist. However, the inclusion
of viscous effects in exact, analytic solutions has received less attention.
Here we utilize Hubble flow to investigate the role of bulk viscosity, and
present different classes of exact, analytic solutions valid also in the
presence of dissipative effects.
|
[
{
"created": "Thu, 10 Oct 2019 15:46:43 GMT",
"version": "v1"
},
{
"created": "Thu, 14 Nov 2019 15:28:44 GMT",
"version": "v2"
}
] |
2020-05-22
|
[
[
"Csanad",
"Mate",
""
],
[
"Nagy",
"Marton I.",
""
],
[
"Jiang",
"Ze-Fang",
""
],
[
"Csorgo",
"Tamas",
""
]
] |
Relativistic hydrodynamics represents a powerful tool to investigate the time evolution of the strongly interacting quark gluon plasma created in ultrarelativistic heavy ion collisions. The equations are solved often numerically, and numerous analytic solutions also exist. However, the inclusion of viscous effects in exact, analytic solutions has received less attention. Here we utilize Hubble flow to investigate the role of bulk viscosity, and present different classes of exact, analytic solutions valid also in the presence of dissipative effects.
|
hep-ph/9506390
|
Robert Peschanski
|
R. Peschanski
|
Two-component colour dipole emission in the central region of
onium-onium scattering
|
3 pages, latex, no figures, requires qcdparis.sty; Contribution to
the PARIS Workshop DIS 95', April 19-24, 1995
| null | null |
Saclay preprint SPhT T95/75
|
hep-ph
| null |
The initial-state radiation of soft colour dipoles produced in the central
region of onium-onium scattering via single QCD Pomeron exchange (BFKL) is
calculated in the framework of Mueller's dipole approach. The resulting dipole
production has a two-component structure. One is constant with energy while the
other grows and possesses a power-law tail at appreciably large transverse
distances from the collision axis. It may be related to the growth of the gluon
distribution at small Bjorken-$x.$
|
[
{
"created": "Thu, 22 Jun 1995 08:01:37 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Peschanski",
"R.",
""
]
] |
The initial-state radiation of soft colour dipoles produced in the central region of onium-onium scattering via single QCD Pomeron exchange (BFKL) is calculated in the framework of Mueller's dipole approach. The resulting dipole production has a two-component structure. One is constant with energy while the other grows and possesses a power-law tail at appreciably large transverse distances from the collision axis. It may be related to the growth of the gluon distribution at small Bjorken-$x.$
|
hep-ph/9511304
|
Myriam Mondragon C.
|
Jisuke Kubo, Myriam Mondragon and George Zoupanos
|
The Top-Bottom Hierarchy from Gauge-Yukawa Unification
|
13 pages, LaTeX and epsf package, Postscript figures. To be published
in the proceedings of the Yukawa International Seminar '95
|
Prog.Theor.Phys.Suppl.123:127-136,1996
|
10.1143/PTPS.123.127
|
KANAZAWA-95-18, HD-THEP-95-50
|
hep-ph
| null |
The idea of Gauge-Yukawa Unification (GYU) based on the principle of
reduction of couplings is elucidated. We show how the observed top-bottom mass
hierarchy can be explained in terms of supersymmetric GYU by considering an
example of the minimal supersymmetric GUT.
|
[
{
"created": "Mon, 13 Nov 1995 15:01:46 GMT",
"version": "v1"
}
] |
2011-01-27
|
[
[
"Kubo",
"Jisuke",
""
],
[
"Mondragon",
"Myriam",
""
],
[
"Zoupanos",
"George",
""
]
] |
The idea of Gauge-Yukawa Unification (GYU) based on the principle of reduction of couplings is elucidated. We show how the observed top-bottom mass hierarchy can be explained in terms of supersymmetric GYU by considering an example of the minimal supersymmetric GUT.
|
2004.14498
|
Lev Dudko
|
E.E. Boos, V.E. Bunichev, L.V. Dudko, M.A. Perfilov, G.A. Vorotnikov
|
Eligibility of EFT approach to search for tqg FCNC phenomenon
| null |
Physics of Atomic Nuclei, 2020, Vol.83, No 6, pp. 921-925
|
10.1134/S1063778820060083
|
Physics of Atomic Nuclei, 2020, Vol. 83, N?. 6, pp. 921-925
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The Effective Field Theory (EFT) approach is widely used in the search for
possible deviations from the predictions of the Standard Model. Such an
approximation of possible BSM physics is valid up to a certain levels of energy
scale and accuracy. In this article, we investigate potential limitation of the
EFT approach related to unitarity to describe possible contributions of flavor
changing neutral currents (FCNC) involving the top quark. The numerical and
analytical calculations of the FCNC processes used in the EFT approach
demonstrate the constant asymptotic behavior of the total cross section with
increasing energy. It is shown that the EFT approach for studying the possible
contribution of FCNC does not violate the restrictions following from
perturbative unitarity, the asymptotic behavior of the cross section does not
exceed the Froissart bound, and the approach itself can be used to set the
corresponding experimental limits for FCNC couplings or Wilson coefficients at
present and future colliders.
|
[
{
"created": "Wed, 29 Apr 2020 22:03:40 GMT",
"version": "v1"
},
{
"created": "Tue, 12 May 2020 19:43:27 GMT",
"version": "v2"
}
] |
2020-11-24
|
[
[
"Boos",
"E. E.",
""
],
[
"Bunichev",
"V. E.",
""
],
[
"Dudko",
"L. V.",
""
],
[
"Perfilov",
"M. A.",
""
],
[
"Vorotnikov",
"G. A.",
""
]
] |
The Effective Field Theory (EFT) approach is widely used in the search for possible deviations from the predictions of the Standard Model. Such an approximation of possible BSM physics is valid up to a certain levels of energy scale and accuracy. In this article, we investigate potential limitation of the EFT approach related to unitarity to describe possible contributions of flavor changing neutral currents (FCNC) involving the top quark. The numerical and analytical calculations of the FCNC processes used in the EFT approach demonstrate the constant asymptotic behavior of the total cross section with increasing energy. It is shown that the EFT approach for studying the possible contribution of FCNC does not violate the restrictions following from perturbative unitarity, the asymptotic behavior of the cross section does not exceed the Froissart bound, and the approach itself can be used to set the corresponding experimental limits for FCNC couplings or Wilson coefficients at present and future colliders.
|
hep-ph/9704205
|
Hsin-Chia Cheng
|
Nima Arkani-Hamed (LBNL), Hsin-Chia Cheng (Fermilab), Jonathan L. Feng
(LBNL), Lawrence J. Hall (LBNL)
|
CP Violation from Slepton Oscillations at the LHC and NLC
|
37 pages, REVTeX, 7 figures
|
Nucl.Phys.B505:3-39,1997
|
10.1016/S0550-3213(97)00433-1
|
LBNL-40147, UCB-PTH-97/16, Fermilab-PUB-97/078-T
|
hep-ph
| null |
In supersymmetric theories the charged sleptons of different generations may
oscillate amongst themselves while they decay. In the case of three generation
oscillations, superpartner production at the LHC and NLC may lead to an
observable $CP$-violating signal $N(e^+\mu^-) - N(\mu^+e^-)$. This signal is
proportional to a $CP$-violating invariant of the slepton mass matrix,
$\widetilde{J}$, which is not constrained by searches for the electric dipole
moment of the electron. The sensitivity of the LHC and NLC to this signal is
highly dependent on superpartner masses, but $\widetilde{J}$ may be probed to a
level of $10^{-3}$. Observation of the $CP$-violating signal would imply a
definite structure for the slepton mass matrices and have strong implications
for models of flavor and SUSY breaking.
|
[
{
"created": "Tue, 1 Apr 1997 22:29:22 GMT",
"version": "v1"
}
] |
2014-11-17
|
[
[
"Arkani-Hamed",
"Nima",
"",
"LBNL"
],
[
"Cheng",
"Hsin-Chia",
"",
"Fermilab"
],
[
"Feng",
"Jonathan L.",
"",
"LBNL"
],
[
"Hall",
"Lawrence J.",
"",
"LBNL"
]
] |
In supersymmetric theories the charged sleptons of different generations may oscillate amongst themselves while they decay. In the case of three generation oscillations, superpartner production at the LHC and NLC may lead to an observable $CP$-violating signal $N(e^+\mu^-) - N(\mu^+e^-)$. This signal is proportional to a $CP$-violating invariant of the slepton mass matrix, $\widetilde{J}$, which is not constrained by searches for the electric dipole moment of the electron. The sensitivity of the LHC and NLC to this signal is highly dependent on superpartner masses, but $\widetilde{J}$ may be probed to a level of $10^{-3}$. Observation of the $CP$-violating signal would imply a definite structure for the slepton mass matrices and have strong implications for models of flavor and SUSY breaking.
|
hep-ph/0606096
|
Marco Stratmann
|
C. Hendlmeier, M. Stratmann, and A. Schafer
|
Hadron-Pair Photoproduction in Longitudinally Polarized Lepton-Nucleon
Collisions
|
10 pages, 9 eps figures
|
Eur.Phys.J.C48:135-145,2006
|
10.1140/epjc/s10052-006-0013-9
| null |
hep-ph
| null |
We present a detailed phenomenological study of photoproduction of two
hadrons, both with high transverse momentum, in longitudinally polarized
lepton-nucleon collisions. We consistently include ``direct'' and ``resolved''
photon contributions and examine the sensitivity of the relevant spin
asymmetries to the gluon polarization in the nucleon and to the completely
unknown parton content of circularly polarized photons. Our results are
relevant for the COMPASS and HERMES fixed-target experiments as well as for a
possible future polarized lepton-proton collider like eRHIC at BNL. So far, all
studies are limited to the lowest order approximation of QCD.
|
[
{
"created": "Thu, 8 Jun 2006 14:38:15 GMT",
"version": "v1"
}
] |
2009-01-07
|
[
[
"Hendlmeier",
"C.",
""
],
[
"Stratmann",
"M.",
""
],
[
"Schafer",
"A.",
""
]
] |
We present a detailed phenomenological study of photoproduction of two hadrons, both with high transverse momentum, in longitudinally polarized lepton-nucleon collisions. We consistently include ``direct'' and ``resolved'' photon contributions and examine the sensitivity of the relevant spin asymmetries to the gluon polarization in the nucleon and to the completely unknown parton content of circularly polarized photons. Our results are relevant for the COMPASS and HERMES fixed-target experiments as well as for a possible future polarized lepton-proton collider like eRHIC at BNL. So far, all studies are limited to the lowest order approximation of QCD.
|
1208.5859
|
Chungku Kim
|
Chungku Kim
|
RG Invariance of the Pole Mass in the Minimal Subtraction Scheme
| null |
J. Kor. Phys. Soc. 62, 1097 (2013)
|
10.3938/jkps.62.1097
| null |
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We prove the renormalization group(RG) invariance of the pole mass with
respect to the RG functions of the minimal subtraction(MS) scheme and
illustrate this in case of the the neutral scalar field theory both in the
symmetric and in the broken symmetry phase.
|
[
{
"created": "Wed, 29 Aug 2012 08:39:55 GMT",
"version": "v1"
}
] |
2015-06-11
|
[
[
"Kim",
"Chungku",
""
]
] |
We prove the renormalization group(RG) invariance of the pole mass with respect to the RG functions of the minimal subtraction(MS) scheme and illustrate this in case of the the neutral scalar field theory both in the symmetric and in the broken symmetry phase.
|
1806.02605
|
Mikhail Zubkov Dr
|
Ruslan Abramchuk, Z.V.Khaidukov, M.A. Zubkov
|
Anatomy of the chiral vortical effect
|
Latex, 16 pages, 10 figures
|
Phys. Rev. D 98, 076013 (2018)
|
10.1103/PhysRevD.98.076013
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider the system of relativistic rotating fermions in the presence of
rotation. The rotation is set up as an enhancement of the angular momentum. In
this approach the angular velocity for the angular momentum plays the same role
as the chemical potential for density. We calculate the axial current using the
direct solutions of the Dirac equation with the MIT bag boundary conditions.
Next, we consider the alternative way of the rotation description, in which the
local velocity of the substance multiplied by the chemical potential serves as
the effective gauge field. In this approach this is possible to relate the
axial current of the chiral vortical effect for the massless fermions to the
topological invariant in momentum space, which is robust to the introduction of
interactions. We compare the results for the axial current obtained using the
two above mentioned approaches.
|
[
{
"created": "Thu, 7 Jun 2018 10:48:45 GMT",
"version": "v1"
}
] |
2018-10-24
|
[
[
"Abramchuk",
"Ruslan",
""
],
[
"Khaidukov",
"Z. V.",
""
],
[
"Zubkov",
"M. A.",
""
]
] |
We consider the system of relativistic rotating fermions in the presence of rotation. The rotation is set up as an enhancement of the angular momentum. In this approach the angular velocity for the angular momentum plays the same role as the chemical potential for density. We calculate the axial current using the direct solutions of the Dirac equation with the MIT bag boundary conditions. Next, we consider the alternative way of the rotation description, in which the local velocity of the substance multiplied by the chemical potential serves as the effective gauge field. In this approach this is possible to relate the axial current of the chiral vortical effect for the massless fermions to the topological invariant in momentum space, which is robust to the introduction of interactions. We compare the results for the axial current obtained using the two above mentioned approaches.
|
hep-ph/0009288
|
Roberto Ugoccioni
|
J. Dias de Deus and R. Ugoccioni
|
Particle Rapidity Density Saturation in Heavy Ion Collisions and the
Dual String Model
|
8 pages, 3 ps figures, latex 2e with amsmath and natbib
|
Phys.Lett. B494 (2000) 53-57
|
10.1016/S0370-2693(00)01183-7
|
FISIST/14-2000/CENTRA
|
hep-ph
| null |
We show that the Dual String Model with fusion leads, in heavy ion
collisions, to strict saturation of the particle (pseudo-)rapidity density,
normalised to the number of participant nucleons, as that number increases.
Asymptotically, as the centre-of-mass energy goes to infinity with the number
of participants fixed, this density approaches the nucleon-nucleon density.
A comparison with recent WA98 data is presented.
|
[
{
"created": "Mon, 25 Sep 2000 16:12:27 GMT",
"version": "v1"
}
] |
2009-10-31
|
[
[
"de Deus",
"J. Dias",
""
],
[
"Ugoccioni",
"R.",
""
]
] |
We show that the Dual String Model with fusion leads, in heavy ion collisions, to strict saturation of the particle (pseudo-)rapidity density, normalised to the number of participant nucleons, as that number increases. Asymptotically, as the centre-of-mass energy goes to infinity with the number of participants fixed, this density approaches the nucleon-nucleon density. A comparison with recent WA98 data is presented.
|
1710.11358
|
Khiem Hong Phan
|
K. H. Phan, T. N. H. Pham
|
Scalar one-loop Feynman integrals with complex internal masses revisited
|
45 pages, more interesting points are discussed in this version
| null | null | null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
In this paper, we study systematically scalar one-loop two-, three-, and
four-point Feynman integrals with complex internal masses. Our analytic results
presented in this report are valid for both real and complex internal masses.
The calculations are then implemented into a {\tt Mathematica} (version $9$)
package and {\tt FORTRAN} program. Our program is cross-checked numerically
with {\tt LoopTools} (version $2.14$) in real as well as complex internal
masses. We find a perfect agreement between our results and {\tt LoopTools} for
all cases. Additionally, this work is applied for evaluating scalar one-loop
Feynman integrals developed leading Landau singularities which may appear in
real scattering processes at colliders. Last but not least, the method used in
this report can also extend to evaluate tensor one-loop integrals. Therefore,
this may open a new approach which can solve the inverse Gram determinant
problem analytically.
|
[
{
"created": "Tue, 31 Oct 2017 07:45:47 GMT",
"version": "v1"
},
{
"created": "Sat, 6 Jan 2018 06:40:13 GMT",
"version": "v2"
},
{
"created": "Tue, 27 Feb 2018 15:38:37 GMT",
"version": "v3"
},
{
"created": "Tue, 18 Sep 2018 02:42:48 GMT",
"version": "v4"
}
] |
2018-09-19
|
[
[
"Phan",
"K. H.",
""
],
[
"Pham",
"T. N. H.",
""
]
] |
In this paper, we study systematically scalar one-loop two-, three-, and four-point Feynman integrals with complex internal masses. Our analytic results presented in this report are valid for both real and complex internal masses. The calculations are then implemented into a {\tt Mathematica} (version $9$) package and {\tt FORTRAN} program. Our program is cross-checked numerically with {\tt LoopTools} (version $2.14$) in real as well as complex internal masses. We find a perfect agreement between our results and {\tt LoopTools} for all cases. Additionally, this work is applied for evaluating scalar one-loop Feynman integrals developed leading Landau singularities which may appear in real scattering processes at colliders. Last but not least, the method used in this report can also extend to evaluate tensor one-loop integrals. Therefore, this may open a new approach which can solve the inverse Gram determinant problem analytically.
|
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