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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1210.0235
|
Carlos Bertulani
|
C. A. Bertulani, T. Frederico, J. Fuqua, M. S. Hussein, O. Oliveira,
and W. de Paula
|
Dark/Visible Parallel Universes and Big Bang Nucleosynthesis
|
Invited talk at the Workshops "CompStar: the physics and astrophysics
of compact stars", Tahiti, June 4-8, 2012, "New Directions in Nuclear
Astrophysics", Castiglion Fiorentino, Italy, June 18-22, 2012, and
"Carpathian Summer School of Physics", Sinaia, Romania, June 24 - July 7,
2012. To be published in AIP Proceedings
| null |
10.1063/1.4768488
| null |
hep-ph astro-ph.CO nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We develop a model for visible matter-dark matter interaction based on the
exchange of a massive gray boson called herein the Mulato. Our model hinges on
the assumption that all known particles in the visible matter have their
counterparts in the dark matter. We postulate six families of particles five of
which are dark. This leads to the unavoidable postulation of six parallel
worlds, the visible one and five invisible worlds. A close study of big bang
nucleosynthesis (BBN), baryon asymmetries, cosmic microwave background (CMB)
bounds, galaxy dynamics, together with the Standard Model assumptions, help us
to set a limit on the mass and width of the new gauge boson. Modification of
the statistics underlying the kinetic energy distribution of particles during
the BBN is also discussed. The changes in reaction rates during the BBN due to
a departure from the Debye-Hueckel electron screening model is also
investigated.
|
[
{
"created": "Sun, 30 Sep 2012 19:58:57 GMT",
"version": "v1"
}
] |
2015-06-11
|
[
[
"Bertulani",
"C. A.",
""
],
[
"Frederico",
"T.",
""
],
[
"Fuqua",
"J.",
""
],
[
"Hussein",
"M. S.",
""
],
[
"Oliveira",
"O.",
""
],
[
"de Paula",
"W.",
""
]
] |
We develop a model for visible matter-dark matter interaction based on the exchange of a massive gray boson called herein the Mulato. Our model hinges on the assumption that all known particles in the visible matter have their counterparts in the dark matter. We postulate six families of particles five of which are dark. This leads to the unavoidable postulation of six parallel worlds, the visible one and five invisible worlds. A close study of big bang nucleosynthesis (BBN), baryon asymmetries, cosmic microwave background (CMB) bounds, galaxy dynamics, together with the Standard Model assumptions, help us to set a limit on the mass and width of the new gauge boson. Modification of the statistics underlying the kinetic energy distribution of particles during the BBN is also discussed. The changes in reaction rates during the BBN due to a departure from the Debye-Hueckel electron screening model is also investigated.
|
1607.06777
|
Darius Jurciukonis
|
D. Jurciukonis and L. Lavoura
|
Group-theoretical search for rows or columns of the lepton mixing matrix
|
23 pages, 1 figure, added references, new appendices concerning the
nilpotent groups and groups with a normal Sylow 3-subgroups, conclusions
unchanged; some minor changes, matches published version
|
J. Phys. G: Nucl. Part. Phys. 44 (2017) 045003
|
10.1088/1361-6471/aa5f44
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We have used the SmallGroups library of groups, together with the computer
algebra systems GAP and Mathematica, to search for groups with a
three-dimensional irreducible representation in which one of the group
generators has a twice-degenerate eigenvalue while another generator has
non-degenerate eigenvalues. By assuming one of these group generators to
commute with the charged-lepton mass matrix and the other one to commute with
the neutrino (Dirac) mass matrix, one derives group-theoretical predictions for
the moduli of the matrix elements of either a row or a column of the lepton
mixing matrix. Our search has produced several realistic predictions for either
the second row, or the third row, or for any of the columns of that matrix.
|
[
{
"created": "Fri, 22 Jul 2016 18:10:07 GMT",
"version": "v1"
},
{
"created": "Fri, 3 Mar 2017 16:28:53 GMT",
"version": "v2"
}
] |
2017-03-06
|
[
[
"Jurciukonis",
"D.",
""
],
[
"Lavoura",
"L.",
""
]
] |
We have used the SmallGroups library of groups, together with the computer algebra systems GAP and Mathematica, to search for groups with a three-dimensional irreducible representation in which one of the group generators has a twice-degenerate eigenvalue while another generator has non-degenerate eigenvalues. By assuming one of these group generators to commute with the charged-lepton mass matrix and the other one to commute with the neutrino (Dirac) mass matrix, one derives group-theoretical predictions for the moduli of the matrix elements of either a row or a column of the lepton mixing matrix. Our search has produced several realistic predictions for either the second row, or the third row, or for any of the columns of that matrix.
|
1410.5423
|
Jonathan Davis
|
Jonathan H. Davis and Joseph Silk
|
Glow in the Dark Matter: Observing galactic halos with scattered light
|
6 pages, 3 figures: v2 matches version accepted to PRL, with an
extended discussion of potential backgrounds
|
Phys. Rev. Lett. 114, 051303 (2015)
|
10.1103/PhysRevLett.114.051303
| null |
hep-ph astro-ph.CO
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider the observation of diffuse halos of light around the discs of
spiral galaxies, as a probe of the interaction cross section between Dark
Matter and photons. Using the galaxy M101 as an example, we show that for a
scattering cross section at the level of 10^(-23) x (m/GeV) cm^2 or greater
Dark Matter in the halo will scatter light out from the more luminous centre of
the disc to larger radii, contributing to an effective increased surface
brightness at the edges of the observed area on the sky. This allows us to set
an upper limit on the DM-photon cross section using data from the Dragonfly
instrument. We then show how to improve this constraint, and the potential for
discovery, by combining the radial profile of DM-photon scattering with
measurements at multiple wavelengths. Observation of diffuse light presents a
new and potentially powerful way to probe the interactions of Dark Matter with
photons, which is complimentary to existing searches.
|
[
{
"created": "Mon, 20 Oct 2014 20:00:06 GMT",
"version": "v1"
},
{
"created": "Wed, 4 Feb 2015 18:36:02 GMT",
"version": "v2"
}
] |
2015-02-05
|
[
[
"Davis",
"Jonathan H.",
""
],
[
"Silk",
"Joseph",
""
]
] |
We consider the observation of diffuse halos of light around the discs of spiral galaxies, as a probe of the interaction cross section between Dark Matter and photons. Using the galaxy M101 as an example, we show that for a scattering cross section at the level of 10^(-23) x (m/GeV) cm^2 or greater Dark Matter in the halo will scatter light out from the more luminous centre of the disc to larger radii, contributing to an effective increased surface brightness at the edges of the observed area on the sky. This allows us to set an upper limit on the DM-photon cross section using data from the Dragonfly instrument. We then show how to improve this constraint, and the potential for discovery, by combining the radial profile of DM-photon scattering with measurements at multiple wavelengths. Observation of diffuse light presents a new and potentially powerful way to probe the interactions of Dark Matter with photons, which is complimentary to existing searches.
|
2301.03869
|
Zhi-Hui Guo
|
Lin-Wan Yan, Yun-Hua Chen, Chun-Gui Duan, Zhi-Hui Guo
|
Effective-Lagrangian study of $\psi'(J/\psi) \to VP$ and the insights
into $\rho\pi$ puzzle
|
20 pages, 5 figures
| null |
10.1103/PhysRevD.107.034022
| null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
Within the effective Lagrangian approach, we carry out a unified study of the
$J/\psi (\psi')\to VP$, $J/\psi \to P\gamma$ and relevant radiative decays of
light-flavor hadrons. Large amount of experimental data, including the various
decay widths and electromagnetic form factors, are fitted to constrain the
numerous hadron couplings. Relative strengths between the strong and
electromagnetic interactions are revealed in the $J/\psi \to VP$ and $\psi' \to
VP$ processes. The effect from the strong interaction is found to dominate in
the $J/\psi \to \rho\pi$ decay, while the electromagnetic interaction turns out
to be the dominant effect in $\psi' \to \rho\pi$ decay, which provides an
explanation to the $\rho\pi$ puzzle. For the $J/\psi\to
K^{*}\bar{K}+\bar{K}^{*}K$ and $\psi' \to K^{*}\bar{K}+\bar{K}^{*}K$, the
former process is dominated by the strong interactions, and the effects from
the electromagnetic parts are found to be comparable with those of strong
interactions in the latter process. Different $SU(3)$ breaking effects from the
electromagnetic parts appear in the charged and neutral channels for the $\psi'
\to K^{*}\bar{K}+\bar{K}^{*}K$ processes explain the rather different ratios
between $B(\psi'\to K^{*+}K^{-}+K^{*-}K^{+})/B(J/\psi\to
K^{*+}K^{-}+K^{*-}K^{+})$ and $B(\psi'\to
K^{*0}\bar{K}^{0}+\bar{K}^{*0}K^{0})/B(J/\psi\to
K^{*0}\bar{K}^{0}+\bar{K}^{*0}K^{0})$.
|
[
{
"created": "Tue, 10 Jan 2023 09:41:41 GMT",
"version": "v1"
}
] |
2023-03-08
|
[
[
"Yan",
"Lin-Wan",
""
],
[
"Chen",
"Yun-Hua",
""
],
[
"Duan",
"Chun-Gui",
""
],
[
"Guo",
"Zhi-Hui",
""
]
] |
Within the effective Lagrangian approach, we carry out a unified study of the $J/\psi (\psi')\to VP$, $J/\psi \to P\gamma$ and relevant radiative decays of light-flavor hadrons. Large amount of experimental data, including the various decay widths and electromagnetic form factors, are fitted to constrain the numerous hadron couplings. Relative strengths between the strong and electromagnetic interactions are revealed in the $J/\psi \to VP$ and $\psi' \to VP$ processes. The effect from the strong interaction is found to dominate in the $J/\psi \to \rho\pi$ decay, while the electromagnetic interaction turns out to be the dominant effect in $\psi' \to \rho\pi$ decay, which provides an explanation to the $\rho\pi$ puzzle. For the $J/\psi\to K^{*}\bar{K}+\bar{K}^{*}K$ and $\psi' \to K^{*}\bar{K}+\bar{K}^{*}K$, the former process is dominated by the strong interactions, and the effects from the electromagnetic parts are found to be comparable with those of strong interactions in the latter process. Different $SU(3)$ breaking effects from the electromagnetic parts appear in the charged and neutral channels for the $\psi' \to K^{*}\bar{K}+\bar{K}^{*}K$ processes explain the rather different ratios between $B(\psi'\to K^{*+}K^{-}+K^{*-}K^{+})/B(J/\psi\to K^{*+}K^{-}+K^{*-}K^{+})$ and $B(\psi'\to K^{*0}\bar{K}^{0}+\bar{K}^{*0}K^{0})/B(J/\psi\to K^{*0}\bar{K}^{0}+\bar{K}^{*0}K^{0})$.
|
1102.5124
|
Shun Zhou
|
Georg G. Raffelt and Shun Zhou
|
Supernova bound on keV-mass sterile neutrinos reexamined
|
6 pages, 4 figures; minor changes, references updated, matches the
published version
|
Phys.Rev.D83:093014,2011
|
10.1103/PhysRevD.83.093014
|
MPP-2011-21
|
hep-ph astro-ph.SR
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Active-sterile neutrino mixing is strongly constrained for m_s > 100 keV to
avoid excessive energy losses from supernova cores. For smaller m_s, matter
effects suppress the effective mixing angle except for a resonant range of
energies where it is enhanced. We study the case of \nu_tau-\nu_s-mixing where
a \nu_tau-\bar\nu_tau asymmetry builds up due to the strong excess of \nu_s
over \bar\nu_s emission or vice versa, reducing the overall emission rate. In
the warm dark matter range m_s < 10 keV the mixing angle is essentially
unconstrained.
|
[
{
"created": "Thu, 24 Feb 2011 22:54:29 GMT",
"version": "v1"
},
{
"created": "Thu, 26 May 2011 15:43:46 GMT",
"version": "v2"
}
] |
2011-06-07
|
[
[
"Raffelt",
"Georg G.",
""
],
[
"Zhou",
"Shun",
""
]
] |
Active-sterile neutrino mixing is strongly constrained for m_s > 100 keV to avoid excessive energy losses from supernova cores. For smaller m_s, matter effects suppress the effective mixing angle except for a resonant range of energies where it is enhanced. We study the case of \nu_tau-\nu_s-mixing where a \nu_tau-\bar\nu_tau asymmetry builds up due to the strong excess of \nu_s over \bar\nu_s emission or vice versa, reducing the overall emission rate. In the warm dark matter range m_s < 10 keV the mixing angle is essentially unconstrained.
|
hep-ph/0511349
|
Giulia Zanderighi
|
G. Zanderighi
|
Resummation of event-shapes at hadron-hadron colliders
|
Invited talk at 2005 International Linear Collider Physics and
Detector Workshop and Second ILC Accelerator Workshop, Snowmass, CO
(Snowmass05), 3 pages
|
ECONFC0508141:ALCPG0419,2005
| null |
ALCPG0419, FERMILAB-CONF-05-528-T, CERN-PH-TH/2005-239
|
hep-ph
| null |
We point out that a study of event shapes at hadron colliders allows to
explore novel aspects of QCD. These studies are today made easier by the
development of a program which automates the resummation.
|
[
{
"created": "Wed, 30 Nov 2005 15:15:22 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Zanderighi",
"G.",
""
]
] |
We point out that a study of event shapes at hadron colliders allows to explore novel aspects of QCD. These studies are today made easier by the development of a program which automates the resummation.
|
2111.02954
|
Stefano Carrazza
|
Stefano Carrazza, Juan M. Cruz-Martinez, Roy Stegeman
|
A data-based parametrization of parton distribution functions
|
10 pages, 7 figures, final version published in EPJC
| null |
10.1140/epjc/s10052-022-10136-z
|
TIF-UNIMI-2021-18
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Since the first determination of a structure function many decades ago, all
methodologies used to determine structure functions or parton distribution
functions (PDFs) have employed a common prefactor as part of the
parametrization. The NNPDF collaboration pioneered the use of neural networks
to overcome the inherent bias of constraining the space of solution with a
fixed functional form while still keeping the same common prefactor as a
preprocessing. Over the years various, increasingly sophisticated, techniques
have been introduced to counter the effect of the prefactor on the PDF
determination. In this paper we present a methodology to remove the prefactor
entirely, thereby significantly simplifying the methodology, without a loss of
efficiency and finding good agreement with previous results.
|
[
{
"created": "Thu, 4 Nov 2021 15:42:22 GMT",
"version": "v1"
},
{
"created": "Tue, 22 Feb 2022 07:57:12 GMT",
"version": "v2"
}
] |
2022-03-09
|
[
[
"Carrazza",
"Stefano",
""
],
[
"Cruz-Martinez",
"Juan M.",
""
],
[
"Stegeman",
"Roy",
""
]
] |
Since the first determination of a structure function many decades ago, all methodologies used to determine structure functions or parton distribution functions (PDFs) have employed a common prefactor as part of the parametrization. The NNPDF collaboration pioneered the use of neural networks to overcome the inherent bias of constraining the space of solution with a fixed functional form while still keeping the same common prefactor as a preprocessing. Over the years various, increasingly sophisticated, techniques have been introduced to counter the effect of the prefactor on the PDF determination. In this paper we present a methodology to remove the prefactor entirely, thereby significantly simplifying the methodology, without a loss of efficiency and finding good agreement with previous results.
|
1409.5078
|
Kohei Kamada
|
Kohei Kamada
|
Inflationary cosmology and the standard model Higgs with a small Hubble
induced mass
|
25 pages, 5 figures; v2: typos corrected, references, figures, and
extended discussions added, matches version published in PLB
| null |
10.1016/j.physletb.2015.01.024
| null |
hep-ph astro-ph.CO hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study the dynamics of the standard model Higgs field in the inflationary
cosmology. Since metastability of our vacuum is indicated by the current
experimental data of the Higgs boson and top quark, inflation models with a
large Hubble parameter may have a problem: In such models, the Higgs field
rolls down towards the unwanted true vacuum due to the large fluctuation in the
inflationary background. However, this problem can be relaxed by supposing an
additional mass term for the Higgs field generated during and after inflation.
We point out that it does not have to be larger than the Hubble parameter if
the number of $e$-folds during inflation is not too large. We demonstrate that
a high reheating temperature is favored in such a relatively small mass case
and it can be checked by future gravitational wave observations. Such an
induced mass can be generated by, {\it e.g.,} a direct coupling to the inflaton
field or nonminimal coupling to gravity.
|
[
{
"created": "Wed, 17 Sep 2014 17:28:42 GMT",
"version": "v1"
},
{
"created": "Fri, 6 Feb 2015 14:55:32 GMT",
"version": "v2"
}
] |
2015-06-22
|
[
[
"Kamada",
"Kohei",
""
]
] |
We study the dynamics of the standard model Higgs field in the inflationary cosmology. Since metastability of our vacuum is indicated by the current experimental data of the Higgs boson and top quark, inflation models with a large Hubble parameter may have a problem: In such models, the Higgs field rolls down towards the unwanted true vacuum due to the large fluctuation in the inflationary background. However, this problem can be relaxed by supposing an additional mass term for the Higgs field generated during and after inflation. We point out that it does not have to be larger than the Hubble parameter if the number of $e$-folds during inflation is not too large. We demonstrate that a high reheating temperature is favored in such a relatively small mass case and it can be checked by future gravitational wave observations. Such an induced mass can be generated by, {\it e.g.,} a direct coupling to the inflaton field or nonminimal coupling to gravity.
|
1505.06986
|
Marcos A. Garcia Garcia
|
John Ellis, Marcos A. G. Garcia, Dimitri V. Nanopoulos, Keith A. Olive
|
Calculations of Inflaton Decays and Reheating: with Applications to
No-Scale Inflation Models
|
33 pages, 14 figures
| null |
10.1088/1475-7516/2015/07/050
|
KCL-PH-TH/2015-23, LCTS/2015-13, CERN-PH-TH/2015-122, ACT-04-15,
MI-TH-1513, UMN-TH-3438/15, FTPI-MINN-15/26
|
hep-ph astro-ph.CO gr-qc hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We discuss inflaton decays and reheating in no-scale Starobinsky-like models
of inflation, calculating the effective equation-of-state parameter, $w$,
during the epoch of inflaton decay, the reheating temperature, $T_{\rm reh}$,
and the number of inflationary e-folds, $N_*$, comparing analytical
approximations with numerical calculations. We then illustrate these results
with applications to models based on no-scale supergravity and motivated by
generic string compactifications, including scenarios where the inflaton is
identified as an untwisted-sector matter field with direct Yukawa couplings to
MSSM fields, and where the inflaton decays via gravitational-strength
interactions. Finally, we use our results to discuss the constraints on these
models imposed by present measurements of the scalar spectral index $n_s$ and
the tensor-to-scalar perturbation ratio $r$, converting them into constraints
on $N_*$, the inflaton decay rate and other parameters of specific no-scale
inflationary models.
|
[
{
"created": "Tue, 26 May 2015 14:58:58 GMT",
"version": "v1"
}
] |
2015-08-06
|
[
[
"Ellis",
"John",
""
],
[
"Garcia",
"Marcos A. G.",
""
],
[
"Nanopoulos",
"Dimitri V.",
""
],
[
"Olive",
"Keith A.",
""
]
] |
We discuss inflaton decays and reheating in no-scale Starobinsky-like models of inflation, calculating the effective equation-of-state parameter, $w$, during the epoch of inflaton decay, the reheating temperature, $T_{\rm reh}$, and the number of inflationary e-folds, $N_*$, comparing analytical approximations with numerical calculations. We then illustrate these results with applications to models based on no-scale supergravity and motivated by generic string compactifications, including scenarios where the inflaton is identified as an untwisted-sector matter field with direct Yukawa couplings to MSSM fields, and where the inflaton decays via gravitational-strength interactions. Finally, we use our results to discuss the constraints on these models imposed by present measurements of the scalar spectral index $n_s$ and the tensor-to-scalar perturbation ratio $r$, converting them into constraints on $N_*$, the inflaton decay rate and other parameters of specific no-scale inflationary models.
|
hep-ph/9610205
|
Thomas Weigl
|
L. Mankiewicz, T. Weigl (TU Munich)
|
Combining Lattice QCD Results with Regge Phenomenology in a Description
of Quark Distribution Functions
|
LaTeX, 17 pages including 7 figures, shorter version will appear in
Phys. Lett. B
|
Phys.Lett. B389 (1996) 334-340
|
10.1016/S0370-2693(96)01274-9
|
TUM/T39-96-21
|
hep-ph
| null |
The most striking feature of quark distribution functions transformed to the
longitudinal distance representation is the recognizable separation of small
and large longitudinal distances. While the former are responsible for the
average properties of parton distributions, the latter can be shown to
determine specifically their small-$x$ behavior. In this paper we demonstrate
how the distribution at intermediate longitudinal distances can be approximated
by taking into account constraints which follow from the general properties of
parton densities, such as their support and behavior at $x \to 1$. We show that
the combined description of small, intermediate, and large longitudinal
distances allows a good approximation of both shape and magnitude of parton
distribution functions. As an application we have calculated low-virtuality C
even and odd (valence) u and d quark parton densities of the nucleon and the
C-even transversity distribution $h_1(x)$, combining recent QCD sum rules and
lattice QCD results with phenomenological information about their small-$x$
behavior.
|
[
{
"created": "Tue, 1 Oct 1996 09:04:46 GMT",
"version": "v1"
}
] |
2009-10-28
|
[
[
"Mankiewicz",
"L.",
"",
"TU Munich"
],
[
"Weigl",
"T.",
"",
"TU Munich"
]
] |
The most striking feature of quark distribution functions transformed to the longitudinal distance representation is the recognizable separation of small and large longitudinal distances. While the former are responsible for the average properties of parton distributions, the latter can be shown to determine specifically their small-$x$ behavior. In this paper we demonstrate how the distribution at intermediate longitudinal distances can be approximated by taking into account constraints which follow from the general properties of parton densities, such as their support and behavior at $x \to 1$. We show that the combined description of small, intermediate, and large longitudinal distances allows a good approximation of both shape and magnitude of parton distribution functions. As an application we have calculated low-virtuality C even and odd (valence) u and d quark parton densities of the nucleon and the C-even transversity distribution $h_1(x)$, combining recent QCD sum rules and lattice QCD results with phenomenological information about their small-$x$ behavior.
|
1306.6498
|
Jean-Philippe Guillet
|
Stefano Catani, Michel Fontannaz, Jean-Philippe Guillet, Eric Pilon
|
Isolating Prompt Photons with Narrow Cones
|
19 pages, 2 figures, 4 tables
| null |
10.1007/JHEP09(2013)007
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We discuss the isolation of prompt photons in hadronic collisions by means of
narrow isolation cones and the QCD computation of the corresponding cross
sections. We reconsider the occurence of large perturbative terms with
logarithmic dependence on the cone size and their impact on the fragmentation
scale dependence. We cure the apparent perturbative violation of unitarity for
small cone sizes, which had been noticed earlier in next-to-leading-order (NLO)
calculations, by resumming the leading logarithmic dependence on the cone size.
We discuss possible implications regarding the implementation of some hollow
cone variants of the cone criterion, which simulate the experimental difficulty
to impose isolation inside the region filled by the electromagnetic shower that
develops in the calorimeter.
|
[
{
"created": "Thu, 27 Jun 2013 13:49:15 GMT",
"version": "v1"
}
] |
2015-06-16
|
[
[
"Catani",
"Stefano",
""
],
[
"Fontannaz",
"Michel",
""
],
[
"Guillet",
"Jean-Philippe",
""
],
[
"Pilon",
"Eric",
""
]
] |
We discuss the isolation of prompt photons in hadronic collisions by means of narrow isolation cones and the QCD computation of the corresponding cross sections. We reconsider the occurence of large perturbative terms with logarithmic dependence on the cone size and their impact on the fragmentation scale dependence. We cure the apparent perturbative violation of unitarity for small cone sizes, which had been noticed earlier in next-to-leading-order (NLO) calculations, by resumming the leading logarithmic dependence on the cone size. We discuss possible implications regarding the implementation of some hollow cone variants of the cone criterion, which simulate the experimental difficulty to impose isolation inside the region filled by the electromagnetic shower that develops in the calorimeter.
|
1101.5555
|
Poul Damgaard
|
N.E.J. Bjerrum-Bohr, Poul H. Damgaard, Bo Feng, Thomas Sondergaard
|
Unusual identities for QCD at tree-level
|
Talk given at XIV Mexican School on Particles and Fields, Morelia,
Nov. 2010
| null |
10.1088/1742-6596/287/1/012030
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We discuss a set of recently discovered quadratic relations between gauge
theory amplitudes. Such relations give additional structural simplifications
for amplitudes in QCD. Remarkably, their origin lie in an analogous set of
relations that involve also gravitons. When certain gluon helicities are
flipped we obtain relations that do not involve gravitons, but which refer only
to QCD.
|
[
{
"created": "Fri, 28 Jan 2011 15:37:15 GMT",
"version": "v1"
}
] |
2015-05-27
|
[
[
"Bjerrum-Bohr",
"N. E. J.",
""
],
[
"Damgaard",
"Poul H.",
""
],
[
"Feng",
"Bo",
""
],
[
"Sondergaard",
"Thomas",
""
]
] |
We discuss a set of recently discovered quadratic relations between gauge theory amplitudes. Such relations give additional structural simplifications for amplitudes in QCD. Remarkably, their origin lie in an analogous set of relations that involve also gravitons. When certain gluon helicities are flipped we obtain relations that do not involve gravitons, but which refer only to QCD.
|
1103.2771
|
Ian Shoemaker
|
Michael L. Graesser, Ian M. Shoemaker, and Luca Vecchi
|
Asymmetric WIMP dark matter
|
32 pages, 6 figures, updated references, updated XENON100 bounds,
typo in figure caption corrected
| null |
10.1007/JHEP10(2011)110
|
LA-UR 11-00565
|
hep-ph astro-ph.CO
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In existing dark matter models with global symmetries the relic abundance of
dark matter is either equal to that of anti-dark matter (thermal WIMP), or
vastly larger, with essentially no remaining anti-dark matter (asymmetric dark
matter). By exploring the consequences of a primordial asymmetry on the coupled
dark matter and anti-dark matter Boltzmann equations we find large regions of
parameter space that interpolate between these two extremes. Interestingly,
this new asymmetric WIMP framework can accommodate a wide range of dark matter
masses and annihilation cross sections. The present-day dark matter population
is typically asymmetric, but only weakly so, such that indirect signals of dark
matter annihilation are not completely suppressed. We apply our results to
existing models, noting that upcoming direct detection experiments will
constrain a large region of the relevant parameter space.
|
[
{
"created": "Mon, 14 Mar 2011 20:00:10 GMT",
"version": "v1"
},
{
"created": "Tue, 26 Jul 2011 22:29:58 GMT",
"version": "v2"
},
{
"created": "Wed, 3 Aug 2011 22:59:32 GMT",
"version": "v3"
}
] |
2015-05-27
|
[
[
"Graesser",
"Michael L.",
""
],
[
"Shoemaker",
"Ian M.",
""
],
[
"Vecchi",
"Luca",
""
]
] |
In existing dark matter models with global symmetries the relic abundance of dark matter is either equal to that of anti-dark matter (thermal WIMP), or vastly larger, with essentially no remaining anti-dark matter (asymmetric dark matter). By exploring the consequences of a primordial asymmetry on the coupled dark matter and anti-dark matter Boltzmann equations we find large regions of parameter space that interpolate between these two extremes. Interestingly, this new asymmetric WIMP framework can accommodate a wide range of dark matter masses and annihilation cross sections. The present-day dark matter population is typically asymmetric, but only weakly so, such that indirect signals of dark matter annihilation are not completely suppressed. We apply our results to existing models, noting that upcoming direct detection experiments will constrain a large region of the relevant parameter space.
|
1302.4191
|
Adrian Bevan
|
Adrian Bevan, Gianluca Inguglia, Michele Zoccali
|
Neutral meson tests of time-reversal symmetry invariance
|
6 pages
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The laws of quantum physics can be studied under the mathematical operation T
that inverts the direction of time. Strong and electromagnetic forces are known
to be invariant under temporal inversion, however the weak force is not. The
BaBar experiment recently exploited the quantum-correlated production of pairs
of B0 mesons to show that T is a broken symmetry. Here we show that it is
possible to perform a wide range of tests of quark flavour changing processes
under T in order to validate the Standard Model of particle physics covering b
to u, d, s, and c transitions as well as c to u, d and s transitions using
entangled B and D pairs created in Y(4S) and psi(3770) decays. We also note
that pseudoscalar decays to two spin one particle final states provide an
additional set of CP filter bases to use for T violation tests.
|
[
{
"created": "Mon, 18 Feb 2013 09:18:17 GMT",
"version": "v1"
},
{
"created": "Tue, 29 Oct 2013 08:42:44 GMT",
"version": "v2"
},
{
"created": "Fri, 2 May 2014 09:11:32 GMT",
"version": "v3"
}
] |
2014-05-05
|
[
[
"Bevan",
"Adrian",
""
],
[
"Inguglia",
"Gianluca",
""
],
[
"Zoccali",
"Michele",
""
]
] |
The laws of quantum physics can be studied under the mathematical operation T that inverts the direction of time. Strong and electromagnetic forces are known to be invariant under temporal inversion, however the weak force is not. The BaBar experiment recently exploited the quantum-correlated production of pairs of B0 mesons to show that T is a broken symmetry. Here we show that it is possible to perform a wide range of tests of quark flavour changing processes under T in order to validate the Standard Model of particle physics covering b to u, d, s, and c transitions as well as c to u, d and s transitions using entangled B and D pairs created in Y(4S) and psi(3770) decays. We also note that pseudoscalar decays to two spin one particle final states provide an additional set of CP filter bases to use for T violation tests.
|
1607.03910
|
Martin Beneke
|
Martin Beneke, Francesco Dighera, Andrzej Hryczuk
|
Finite-temperature modification of heavy particle decay and dark matter
annihilation
|
13 pages, 3 figures
| null |
10.1007/JHEP09(2016)031
|
TUM-HEP 1052/16
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We apply the operator product expansion (OPE) technique to the decay and
annihilation of heavy particles in a thermal medium with temperature below the
heavy particle mass, m_chi. This allows us to explain two interesting
observations made before: a) that the leading thermal correction to the decay
width of a charged particle is the same multiplicative factor of the
zero-temperature width for a two-body decay and muon decay, and b) that the
leading thermal correction to fermionic dark matter annihilation arises only at
order T^4/m_chi^4. The OPE further considerably simplifies the computation and
factorizes it into model-independent matrix elements in the thermal background,
and short-distance coefficients to be computed in zero-temperature field
theory.
|
[
{
"created": "Wed, 13 Jul 2016 20:06:58 GMT",
"version": "v1"
}
] |
2016-10-12
|
[
[
"Beneke",
"Martin",
""
],
[
"Dighera",
"Francesco",
""
],
[
"Hryczuk",
"Andrzej",
""
]
] |
We apply the operator product expansion (OPE) technique to the decay and annihilation of heavy particles in a thermal medium with temperature below the heavy particle mass, m_chi. This allows us to explain two interesting observations made before: a) that the leading thermal correction to the decay width of a charged particle is the same multiplicative factor of the zero-temperature width for a two-body decay and muon decay, and b) that the leading thermal correction to fermionic dark matter annihilation arises only at order T^4/m_chi^4. The OPE further considerably simplifies the computation and factorizes it into model-independent matrix elements in the thermal background, and short-distance coefficients to be computed in zero-temperature field theory.
|
hep-ph/9710269
|
Vladimir Vechernin
|
M.A. Braun, V.V. Vechernin (St.Petersburg State University)
|
Deuteron Disintegration in Quark-Parton Model
|
8 pages, LaTeX
| null | null |
SPbU-IP-97-18
|
hep-ph
| null |
The deuteron disintegration process with the emission of fast proton in the
vicinity of the kinematical boundary of the reaction, when Feynman variable
$x\to 2$, is studied. The consideration is fulfilled in the framework of the
quark-parton model of cumulative phenomena based on perturbative QCD
calculations of the corresponding quark diagrams near the thresholds, at which
some quarks ("donors") in the nuclear flucton transfer all their longitudinal
momenta to the distinguished active quarks and become soft. The presence of the
multi-quark $6q$-configuration in a deuteron is essentially exploited in the
consideration. The different versions of hadronization mechanisms of the
produced cumulative quarks into cumulative particles are analyzed. It is shown
that in the case of the production of cumulative protons from deuteron the
hadronization through the coalescence of three cumulative quarks is favorable
and leads to the $(2-x)^5$ cross section threshold behavior whereas the usual
hadronization through one cumulative quark fragmentation into proton the same
as the calculations predicts for the deuteron structure function $F^d_2(x)$ at
$x\to 2$ in DIS processes. The results of the calculations are compared with
the available experimental data.
|
[
{
"created": "Tue, 7 Oct 1997 15:13:06 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Braun",
"M. A.",
"",
"St.Petersburg State University"
],
[
"Vechernin",
"V. V.",
"",
"St.Petersburg State University"
]
] |
The deuteron disintegration process with the emission of fast proton in the vicinity of the kinematical boundary of the reaction, when Feynman variable $x\to 2$, is studied. The consideration is fulfilled in the framework of the quark-parton model of cumulative phenomena based on perturbative QCD calculations of the corresponding quark diagrams near the thresholds, at which some quarks ("donors") in the nuclear flucton transfer all their longitudinal momenta to the distinguished active quarks and become soft. The presence of the multi-quark $6q$-configuration in a deuteron is essentially exploited in the consideration. The different versions of hadronization mechanisms of the produced cumulative quarks into cumulative particles are analyzed. It is shown that in the case of the production of cumulative protons from deuteron the hadronization through the coalescence of three cumulative quarks is favorable and leads to the $(2-x)^5$ cross section threshold behavior whereas the usual hadronization through one cumulative quark fragmentation into proton the same as the calculations predicts for the deuteron structure function $F^d_2(x)$ at $x\to 2$ in DIS processes. The results of the calculations are compared with the available experimental data.
|
hep-ph/0703201
|
S. Atag
|
S. Atag and I. Sahin
|
Anomalous Quartic $WW\gamma\gamma$ and $ZZ\gamma\gamma$ Couplings in
$e\gamma$ Collision With Initial Beams and Final State Polarizations
| null |
Phys.Rev.D75:073003,2007
|
10.1103/PhysRevD.75.073003
| null |
hep-ph
| null |
The constraints on the anomalous quartic $WW\gamma\gamma$ and
$ZZ\gamma\gamma$ gauge boson couplings are investigated through the processes
$e\gamma\to W^{-}\gamma\nu_{e}$ and $e\gamma\to Z\gamma e$. Considering the
longitudinal and transverse polarization states of the final W or Z boson and
incoming beam polarizations we find 95% confidence level limits on the
anomalous coupling parameters $a_{0}$ and $a_{c}$ with an integrated luminosity
of 500 $fb^{-1}$ and $\sqrt{s}$=0.5, 1 TeV energies. Assuming the
$W^{+}W^{-}\gamma\gamma$ couplings are independent of the $ZZ\gamma\gamma$
couplings we show that the longitudinal polarization state of the final gauge
boson improves the sensitivity to anomalous couplings by a factor of 2-3
depending on energy and coupling. An extra enhancement in sensitivity by a
factor of 1.3 comes from a set of initial beam polarizations.
|
[
{
"created": "Mon, 19 Mar 2007 14:04:31 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Atag",
"S.",
""
],
[
"Sahin",
"I.",
""
]
] |
The constraints on the anomalous quartic $WW\gamma\gamma$ and $ZZ\gamma\gamma$ gauge boson couplings are investigated through the processes $e\gamma\to W^{-}\gamma\nu_{e}$ and $e\gamma\to Z\gamma e$. Considering the longitudinal and transverse polarization states of the final W or Z boson and incoming beam polarizations we find 95% confidence level limits on the anomalous coupling parameters $a_{0}$ and $a_{c}$ with an integrated luminosity of 500 $fb^{-1}$ and $\sqrt{s}$=0.5, 1 TeV energies. Assuming the $W^{+}W^{-}\gamma\gamma$ couplings are independent of the $ZZ\gamma\gamma$ couplings we show that the longitudinal polarization state of the final gauge boson improves the sensitivity to anomalous couplings by a factor of 2-3 depending on energy and coupling. An extra enhancement in sensitivity by a factor of 1.3 comes from a set of initial beam polarizations.
|
hep-ph/9311355
|
Luc Marleau
|
L. Marleau
|
New classes of summable Skyrmions
|
9 pages, revtex v3, EP-CPTh.A274.1193 and LAVAL-PHY-11-93
|
Can.J.Phys. 73 (1995) 6-10
|
10.1139/p95-002
| null |
hep-ph
| null |
We introduce two new classes of summable Skyrmions. The Lagrangians they
originate from are explicitely constructed. We also analyse how some models
could be solve. Exact solutions are found for Skyrme-like toy models.
|
[
{
"created": "Wed, 24 Nov 1993 14:01:14 GMT",
"version": "v1"
},
{
"created": "Fri, 10 Dec 1993 13:55:53 GMT",
"version": "v2"
}
] |
2015-06-25
|
[
[
"Marleau",
"L.",
""
]
] |
We introduce two new classes of summable Skyrmions. The Lagrangians they originate from are explicitely constructed. We also analyse how some models could be solve. Exact solutions are found for Skyrme-like toy models.
|
hep-ph/0206064
|
Guy Raz
|
Yosef Nir and Guy Raz
|
Quark-Squark Alignment Revisited
|
20 pages, 3 figures
|
Phys.Rev. D66 (2002) 035007
|
10.1103/PhysRevD.66.035007
| null |
hep-ph
| null |
We re-examine the possibility that the solution to the supersymmetric flavor
problem is related to small mixing angles in gaugino couplings induced by
approximate horizontal Abelian symmetries. We prove that, for a large class of
models, there is a single viable structure for the down quark mass matrix with
four holomorphic zeros. Consequently, we are able to obtain both lower and
upper bounds on the supersymmetric mixing angles and predict the contributions
to various flavor changing neutral current processes. We find that the most
likely signals for alignment are $\Delta m_D$ close to the present bound,
significant CP violation in $D^0-\bar{D^0}$ mixing, and shifts of order a few
percent in various CP asymmetries in $B^0$ and $B_s$ decays. In contrast, the
modifications to radiative B decays, to $\epsilon^\prime/\epsilon$ and to
$K\to\pi\nu\bar\nu$ decays are small. We further investigate a new class of
alignment models, where supersymmetric contributions to flavor changing
processes are suppressed by both alignment and RGE-induced degeneracy.
|
[
{
"created": "Thu, 6 Jun 2002 08:06:20 GMT",
"version": "v1"
}
] |
2009-11-07
|
[
[
"Nir",
"Yosef",
""
],
[
"Raz",
"Guy",
""
]
] |
We re-examine the possibility that the solution to the supersymmetric flavor problem is related to small mixing angles in gaugino couplings induced by approximate horizontal Abelian symmetries. We prove that, for a large class of models, there is a single viable structure for the down quark mass matrix with four holomorphic zeros. Consequently, we are able to obtain both lower and upper bounds on the supersymmetric mixing angles and predict the contributions to various flavor changing neutral current processes. We find that the most likely signals for alignment are $\Delta m_D$ close to the present bound, significant CP violation in $D^0-\bar{D^0}$ mixing, and shifts of order a few percent in various CP asymmetries in $B^0$ and $B_s$ decays. In contrast, the modifications to radiative B decays, to $\epsilon^\prime/\epsilon$ and to $K\to\pi\nu\bar\nu$ decays are small. We further investigate a new class of alignment models, where supersymmetric contributions to flavor changing processes are suppressed by both alignment and RGE-induced degeneracy.
|
1309.7348
|
Bryan Zald\'ivar Montero
|
Mattias Blennow, Enrique Fernandez-Martinez and Bryan Zaldivar
|
Freeze-in through portals
|
18 pages, 6 figures
| null |
10.1088/1475-7516/2014/01/003
| null |
hep-ph astro-ph.HE
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The popular freeze-out paradigm for Dark Matter (DM) production, relies on
DM-baryon couplings of the order of the weak interactions. However, different
search strategies for DM have failed to provide a conclusive evidence of such
(non-gravitational) interactions, while greatly reducing the parameter space of
many representative models. This motivates the study of alternative mechanisms
for DM genesis. In the freeze-in framework, the DM is slowly populated from the
thermal bath while never reaching equilibrium. In this work, we analyse in
detail the possibility of producing a frozen-in DM via a mediator particle
which acts as a portal. We give analytical estimates of different freeze-in
regimes and support them with full numerical analyses, taking into account the
proper distribution functions of bath particles. Finally, we constrain the
parameter space of generic models by requiring agreement with DM relic
abundance observations.
|
[
{
"created": "Fri, 27 Sep 2013 20:00:01 GMT",
"version": "v1"
}
] |
2015-06-17
|
[
[
"Blennow",
"Mattias",
""
],
[
"Fernandez-Martinez",
"Enrique",
""
],
[
"Zaldivar",
"Bryan",
""
]
] |
The popular freeze-out paradigm for Dark Matter (DM) production, relies on DM-baryon couplings of the order of the weak interactions. However, different search strategies for DM have failed to provide a conclusive evidence of such (non-gravitational) interactions, while greatly reducing the parameter space of many representative models. This motivates the study of alternative mechanisms for DM genesis. In the freeze-in framework, the DM is slowly populated from the thermal bath while never reaching equilibrium. In this work, we analyse in detail the possibility of producing a frozen-in DM via a mediator particle which acts as a portal. We give analytical estimates of different freeze-in regimes and support them with full numerical analyses, taking into account the proper distribution functions of bath particles. Finally, we constrain the parameter space of generic models by requiring agreement with DM relic abundance observations.
|
hep-ph/0012259
|
Satyanarayan Nandi
|
D.A. Dicus, C.D. McMullen and S. Nandi
|
Collider Implications of Kaluza-Klein Excitations of the Gluons
|
33 pages, LaTeX; added Figure 6 showing the dijet mass distribution
and corresponding discussion in a paragraph on page 11; some additionaal
discussions added; typos corrected; few references added
|
Phys.Rev.D65:076007,2002
|
10.1103/PhysRevD.65.076007
|
OSU-HEP-00-06,UTEXAS-HEP-00-12
|
hep-ph
| null |
We consider an asymmetric string compactification scenario in which the SM
gauge bosons can propagate into one TeV$^{-1}$-size extra compact dimension.
These gauge bosons have associated KK excitations that present additional
contributions to the SM processes. We calculate the effects that the KK
excitations of the gluons, $g^{\star}$'s, have on multijet final state
production in proton-proton collisions at the Large Hadron Collider energy. In
the case of dijet final states with very high $p_{{}_T}$, the KK signal due to
the exchanges of the $g^{\star}$'s is several factors greater than the SM
background for compactification scales as high as about 7 TeV. The
high-$p_{{}_T}$ effect is not as dramatic for the direct production of a single
on-shell $g^{\star}$, which subsequently decays into $q$-$\bar{q}$ pairs, where
the KK signal significantly exceeds the SM three-jet background for
compactification scales up to about 3 TeV. We also present our results for the
four-jet final state signal from the direct production of two on-shell
$g^{\star}$'s.
|
[
{
"created": "Tue, 19 Dec 2000 23:09:56 GMT",
"version": "v1"
},
{
"created": "Thu, 28 Dec 2000 06:18:33 GMT",
"version": "v2"
},
{
"created": "Thu, 6 Dec 2001 05:21:30 GMT",
"version": "v3"
}
] |
2014-11-17
|
[
[
"Dicus",
"D. A.",
""
],
[
"McMullen",
"C. D.",
""
],
[
"Nandi",
"S.",
""
]
] |
We consider an asymmetric string compactification scenario in which the SM gauge bosons can propagate into one TeV$^{-1}$-size extra compact dimension. These gauge bosons have associated KK excitations that present additional contributions to the SM processes. We calculate the effects that the KK excitations of the gluons, $g^{\star}$'s, have on multijet final state production in proton-proton collisions at the Large Hadron Collider energy. In the case of dijet final states with very high $p_{{}_T}$, the KK signal due to the exchanges of the $g^{\star}$'s is several factors greater than the SM background for compactification scales as high as about 7 TeV. The high-$p_{{}_T}$ effect is not as dramatic for the direct production of a single on-shell $g^{\star}$, which subsequently decays into $q$-$\bar{q}$ pairs, where the KK signal significantly exceeds the SM three-jet background for compactification scales up to about 3 TeV. We also present our results for the four-jet final state signal from the direct production of two on-shell $g^{\star}$'s.
|
1710.09292
|
Susan Gardner
|
Susan Gardner, Xinshuai Yan
|
Phenomenology of neutron-antineutron conversion
|
19 pages, REVTeX, 3 figures; typos fixed and minor clarifications and
refs. added
|
Phys. Rev. D 97, 056008 (2018)
|
10.1103/PhysRevD.97.056008
| null |
hep-ph hep-ex nucl-ex nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider the possibility of neutron-antineutron ($n-\bar n$) conversion,
in which the change of a neutron into an antineutron is mediated by an external
source, as can occur in a scattering process. We develop the connections
between $n-{\bar n}$ conversion and $n-{\bar n}$ oscillation, in which a
neutron spontaneously tranforms into an antineutron, noting that if $n-{\bar
n}$ oscillation occurs in a theory with B-L violation, then $n-{\bar n}$
conversion can occur also. We show how an experimental limit on $n-{\bar n}$
conversion could connect concretely to a limit on $n-{\bar n}$ oscillation, and
vice versa, using effective field theory techniques and baryon matrix elements
computed in the M.I.T. bag model.
|
[
{
"created": "Wed, 25 Oct 2017 15:07:19 GMT",
"version": "v1"
},
{
"created": "Wed, 15 Nov 2017 03:37:03 GMT",
"version": "v2"
}
] |
2018-03-21
|
[
[
"Gardner",
"Susan",
""
],
[
"Yan",
"Xinshuai",
""
]
] |
We consider the possibility of neutron-antineutron ($n-\bar n$) conversion, in which the change of a neutron into an antineutron is mediated by an external source, as can occur in a scattering process. We develop the connections between $n-{\bar n}$ conversion and $n-{\bar n}$ oscillation, in which a neutron spontaneously tranforms into an antineutron, noting that if $n-{\bar n}$ oscillation occurs in a theory with B-L violation, then $n-{\bar n}$ conversion can occur also. We show how an experimental limit on $n-{\bar n}$ conversion could connect concretely to a limit on $n-{\bar n}$ oscillation, and vice versa, using effective field theory techniques and baryon matrix elements computed in the M.I.T. bag model.
|
hep-ph/0606288
|
Alexey Gladyshev
|
A.V.Gladyshev, D.I.Kazakov
|
Supersymmetry and LHC
|
Lectures given at the 9th Moscow International School of Physics
(XXXIV ITEP Winter School of Physics)
|
Phys.Atom.Nucl.70:1553-1567,2007
|
10.1134/S1063778807090104
| null |
hep-ph
| null |
The motivation for introduction of supersymmetry in high energy physics as
well as a possibility for supersymmetry discovery at LHC (Large Hadronic
Collider) are discussed. The main notions of the Minimal Supersymmetric
Standard Model (MSSM) are introduced. Different regions of parameter space are
analyzed and their phenomenological properties are compared. Discovery
potential of LHC for the planned luminosity is shown for different channels.
The properties of SUSY Higgs bosons are studied and perspectives of their
observation at LHC are briefly outlined.
|
[
{
"created": "Wed, 28 Jun 2006 15:38:26 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Gladyshev",
"A. V.",
""
],
[
"Kazakov",
"D. I.",
""
]
] |
The motivation for introduction of supersymmetry in high energy physics as well as a possibility for supersymmetry discovery at LHC (Large Hadronic Collider) are discussed. The main notions of the Minimal Supersymmetric Standard Model (MSSM) are introduced. Different regions of parameter space are analyzed and their phenomenological properties are compared. Discovery potential of LHC for the planned luminosity is shown for different channels. The properties of SUSY Higgs bosons are studied and perspectives of their observation at LHC are briefly outlined.
|
1003.5904
|
Chitta Ranjan Das
|
C.R. Das and Joao Pulido
|
Improving LMA predictions with non standard interactions
| null | null | null |
CFTP/10-005
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
It has been known for some time that the well established LMA solution to the
observed solar neutrino deficit fails to predict a flat energy spectrum for
SuperKamiokande as opposed to what the data indicates. It also leads to a
Chlorine rate which appears to be too high as compared to the data. We
investigate the possible solution to these inconsistencies with non standard
neutrino interactions, assuming that they come as extra contributions to the
$\nu_{\alpha}\nu_{\beta}$ and $\nu_{\alpha}e$ vertices that affect both the
propagation of neutrinos through solar matter and their detection. We find
that, among the many possibilities for non standard couplings, only one of them
leads to a flat SuperKamiokande spectral rate in better agreement with the data
and predicts a Chlorine rate within 1$\sigma$ of the observed one, while
keeping all other predictions accurate.
|
[
{
"created": "Tue, 30 Mar 2010 19:29:13 GMT",
"version": "v1"
}
] |
2010-04-01
|
[
[
"Das",
"C. R.",
""
],
[
"Pulido",
"Joao",
""
]
] |
It has been known for some time that the well established LMA solution to the observed solar neutrino deficit fails to predict a flat energy spectrum for SuperKamiokande as opposed to what the data indicates. It also leads to a Chlorine rate which appears to be too high as compared to the data. We investigate the possible solution to these inconsistencies with non standard neutrino interactions, assuming that they come as extra contributions to the $\nu_{\alpha}\nu_{\beta}$ and $\nu_{\alpha}e$ vertices that affect both the propagation of neutrinos through solar matter and their detection. We find that, among the many possibilities for non standard couplings, only one of them leads to a flat SuperKamiokande spectral rate in better agreement with the data and predicts a Chlorine rate within 1$\sigma$ of the observed one, while keeping all other predictions accurate.
|
1605.01157
|
Dai-suke Takahashi
|
Arindam Das, Satsuki Oda, Nobuchika Okada, Dai-suke Takahashi
|
Classically conformal U(1)' extended standard model, electroweak vacuum
stability, and LHC Run-2 bounds
|
35 pages, 10 figures. The version published in Physical Review D.
arXiv admin note: substantial text overlap with arXiv:1504.06291
|
Phys. Rev. D 93, 115038 (2016)
|
10.1103/PhysRevD.93.115038
| null |
hep-ph hep-ex hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider the minimal U(1)' extension of the standard model (SM) with the
classically conformal invariance, where an anomaly-free U(1)' gauge symmetry is
introduced along with three generations of right-handed neutrinos and a U(1)'
Higgs field. Since the classically conformal symmetry forbids all dimensional
parameters in the model, the U(1)' gauge symmetry is broken by the
Coleman-Weinberg mechanism, generating the mass terms of the U(1)' gauge boson
($Z$' boson) and the right-handed neutrinos. Through a mixing quartic coupling
between the U(1)' Higgs field and the SM Higgs doublet field, the radiative
U(1)' gauge symmetry breaking also triggers the breaking of the electroweak
symmetry. In this model context, we first investigate the electroweak vacuum
instability problem in the SM. Employing the renormalization group equations at
the two-loop level and the central values for the world average masses of the
top quark ($m_t=173.34$ GeV) and the Higgs boson ($m_h=125.09$ GeV), we perform
parameter scans to identify the parameter region for resolving the electroweak
vacuum instability problem. Next we interpret the recent ATLAS and CMS search
limits at the LHC Run-2 for the sequential $Z$' boson to constrain the
parameter region in our model. Combining the constraints from the electroweak
vacuum stability and the LHC Run-2 results, we find a bound on the $Z$' boson
mass as $m_{Z'} \gtrsim 3.5$ TeV. We also calculate self-energy corrections to
the SM Higgs doublet field through the heavy states, the right-handed neutrinos
and the $Z$' boson, and find the naturalness bound as $m_{Z'} \lesssim 7$ TeV,
in order to reproduce the right electroweak scale for the fine-tuning level
better than 10\%. The resultant mass range of $3.5$ TeV $\lesssim m_{Z'}
\lesssim 7$ TeV will be explored at the LHC Run-2 in the near future.
|
[
{
"created": "Wed, 4 May 2016 06:41:17 GMT",
"version": "v1"
},
{
"created": "Thu, 5 May 2016 11:56:17 GMT",
"version": "v2"
},
{
"created": "Sat, 2 Jul 2016 06:56:07 GMT",
"version": "v3"
}
] |
2016-07-06
|
[
[
"Das",
"Arindam",
""
],
[
"Oda",
"Satsuki",
""
],
[
"Okada",
"Nobuchika",
""
],
[
"Takahashi",
"Dai-suke",
""
]
] |
We consider the minimal U(1)' extension of the standard model (SM) with the classically conformal invariance, where an anomaly-free U(1)' gauge symmetry is introduced along with three generations of right-handed neutrinos and a U(1)' Higgs field. Since the classically conformal symmetry forbids all dimensional parameters in the model, the U(1)' gauge symmetry is broken by the Coleman-Weinberg mechanism, generating the mass terms of the U(1)' gauge boson ($Z$' boson) and the right-handed neutrinos. Through a mixing quartic coupling between the U(1)' Higgs field and the SM Higgs doublet field, the radiative U(1)' gauge symmetry breaking also triggers the breaking of the electroweak symmetry. In this model context, we first investigate the electroweak vacuum instability problem in the SM. Employing the renormalization group equations at the two-loop level and the central values for the world average masses of the top quark ($m_t=173.34$ GeV) and the Higgs boson ($m_h=125.09$ GeV), we perform parameter scans to identify the parameter region for resolving the electroweak vacuum instability problem. Next we interpret the recent ATLAS and CMS search limits at the LHC Run-2 for the sequential $Z$' boson to constrain the parameter region in our model. Combining the constraints from the electroweak vacuum stability and the LHC Run-2 results, we find a bound on the $Z$' boson mass as $m_{Z'} \gtrsim 3.5$ TeV. We also calculate self-energy corrections to the SM Higgs doublet field through the heavy states, the right-handed neutrinos and the $Z$' boson, and find the naturalness bound as $m_{Z'} \lesssim 7$ TeV, in order to reproduce the right electroweak scale for the fine-tuning level better than 10\%. The resultant mass range of $3.5$ TeV $\lesssim m_{Z'} \lesssim 7$ TeV will be explored at the LHC Run-2 in the near future.
|
1602.08352
|
Juergen Reuter
|
J\"urgen Reuter
|
The BSM Physics Case of the ILC
|
8 pages, 2 figures, Talk presented at the International Workshop on
Future Linear Colliders (LCWS15), Whistler, Canada, 2-6 November 2015
| null | null |
DESY 16-031
|
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In this talk I summarize the physics case of the International Linear
Collider (ILC) focusing on its potential towards discovery, discrimation or
disentanglement of new physics beyond the Standard Model (BSM).
|
[
{
"created": "Fri, 26 Feb 2016 14:52:45 GMT",
"version": "v1"
}
] |
2016-02-29
|
[
[
"Reuter",
"Jürgen",
""
]
] |
In this talk I summarize the physics case of the International Linear Collider (ILC) focusing on its potential towards discovery, discrimation or disentanglement of new physics beyond the Standard Model (BSM).
|
hep-ph/0202124
|
Jonathan Feng
|
Luis A. Anchordoqui, Jonathan L. Feng, Haim Goldberg
|
p-Branes and the GZK Paradox
|
8 pages, 6 figures
|
Phys.Lett. B535 (2002) 302-308
|
10.1016/S0370-2693(02)01766-5
|
NUB-3226-Th-02, MIT-CTP-3245, UCI-TR-2002-5
|
hep-ph astro-ph hep-ex hep-th
| null |
In spacetimes with asymmetric extra dimensions, cosmic neutrino interactions
may be extraordinarily enhanced by p-brane production. Brane formation and
decay may then initiate showers deep in the Earth's atmosphere at rates far
above the standard model rate. We explore the p-brane discovery potential of
cosmic ray experiments. The absence of deeply penetrating showers at AGASA
already provides multi-TeV bounds on the fundamental Planck scale that
significantly exceed those obtained from black hole production in symmetric
compactification scenarios. This sensitivity will be further enhanced at the
Auger Observatory. We also examine the possibility that p-brane formation
resolves the GZK paradox. For flat compactifications, astrophysical bounds
exclude this explanation. For warped scenarios, a solution could be consistent
with the absence of deep showers only for extra dimensions with fine-tuned
sizes well below the fundamental Planck length. In addition, it requires
moderately penetrating showers, so far not reported, and ~100% modifications to
standard model phenomenology at 100 GeV energies.
|
[
{
"created": "Thu, 14 Feb 2002 19:58:41 GMT",
"version": "v1"
}
] |
2009-11-07
|
[
[
"Anchordoqui",
"Luis A.",
""
],
[
"Feng",
"Jonathan L.",
""
],
[
"Goldberg",
"Haim",
""
]
] |
In spacetimes with asymmetric extra dimensions, cosmic neutrino interactions may be extraordinarily enhanced by p-brane production. Brane formation and decay may then initiate showers deep in the Earth's atmosphere at rates far above the standard model rate. We explore the p-brane discovery potential of cosmic ray experiments. The absence of deeply penetrating showers at AGASA already provides multi-TeV bounds on the fundamental Planck scale that significantly exceed those obtained from black hole production in symmetric compactification scenarios. This sensitivity will be further enhanced at the Auger Observatory. We also examine the possibility that p-brane formation resolves the GZK paradox. For flat compactifications, astrophysical bounds exclude this explanation. For warped scenarios, a solution could be consistent with the absence of deep showers only for extra dimensions with fine-tuned sizes well below the fundamental Planck length. In addition, it requires moderately penetrating showers, so far not reported, and ~100% modifications to standard model phenomenology at 100 GeV energies.
|
hep-ph/0111004
|
Jonathan Feng
|
Jonathan L. Feng (MIT, UC Irvine), Konstantin T. Matchev (CERN)
|
g_\mu - 2 in Supersymmetry
|
3 pages, 2 figures, RevTeX4, contribution to Snowmass 2001
| null | null |
MIT-CTP-3198, UCI-TR-2001-31, CERN-TH/2001-296, Snowmass P3-08
|
hep-ph
| null |
The 2.6 sigma deviation in the muon's anomalous magnetic moment has strong
implications for supersymmetry. In the most model-independent analysis to date,
we consider gaugino masses with arbitrary magnitude and phase, and sleptons
with arbitrary masses and left-right mixings. For tan(beta)=50, we find that 1
sigma agreement requires at least one charged superpartner with mass below 570
GeV; at 2 sigma, this upper bound shifts to 850 GeV. The deviation is
remarkably consistent with all constraints from colliders, dark matter, and b
-> s gamma in supergravity models, but disfavors the characteristic gaugino
mass relations of anomaly-mediation.
|
[
{
"created": "Wed, 31 Oct 2001 23:24:27 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Feng",
"Jonathan L.",
"",
"MIT, UC Irvine"
],
[
"Matchev",
"Konstantin T.",
"",
"CERN"
]
] |
The 2.6 sigma deviation in the muon's anomalous magnetic moment has strong implications for supersymmetry. In the most model-independent analysis to date, we consider gaugino masses with arbitrary magnitude and phase, and sleptons with arbitrary masses and left-right mixings. For tan(beta)=50, we find that 1 sigma agreement requires at least one charged superpartner with mass below 570 GeV; at 2 sigma, this upper bound shifts to 850 GeV. The deviation is remarkably consistent with all constraints from colliders, dark matter, and b -> s gamma in supergravity models, but disfavors the characteristic gaugino mass relations of anomaly-mediation.
|
hep-ph/9805467
|
Steen H. Hansen
|
A.D. Dolgov, S.H. Hansen, D.V. Semikoz
|
Nonequilibrium Corrections to the Spectra of Massless Neutrinos in the
Early Universe - Addendum
|
8 pages, 2 tables
|
Nucl.Phys. B543 (1999) 269-274
|
10.1016/S0550-3213(98)00818-9
| null |
hep-ph
| null |
We repeat our previous calculation of the spectrum distortion of massless
neutrinos in the early universe with a considerably better accuracy and
corrected for a missing numerical factor in one of the two ways of calculations
presented in hep-ph/9703315. Now both ways of calculations are in perfect
agreement and we essentially reproduce our old results presented in the
abstract of the paper and used in the calculations of light element abundances.
We disagree with the criticism of our calculations presented in
astro-ph/9712199.
|
[
{
"created": "Tue, 26 May 1998 18:26:55 GMT",
"version": "v1"
}
] |
2009-10-31
|
[
[
"Dolgov",
"A. D.",
""
],
[
"Hansen",
"S. H.",
""
],
[
"Semikoz",
"D. V.",
""
]
] |
We repeat our previous calculation of the spectrum distortion of massless neutrinos in the early universe with a considerably better accuracy and corrected for a missing numerical factor in one of the two ways of calculations presented in hep-ph/9703315. Now both ways of calculations are in perfect agreement and we essentially reproduce our old results presented in the abstract of the paper and used in the calculations of light element abundances. We disagree with the criticism of our calculations presented in astro-ph/9712199.
|
1012.3478
|
Osamu Yasuda
|
Osamu Yasuda
|
Some attempts to explain MINOS anomaly
|
3 pages, 1 figure, uses aipproc.cls. Talk given at the 12th
International Workshop on Neutrino Factories, Superbeams and Beta Beams
(NuFact10), October 20-25, 2010, Mumbai, India
| null |
10.1063/1.3644281
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Some attempts which were made to explain the MINOS anomaly are critically
discussed. They include the non-standard neutral current-neutrino interaction
and the (3+1)-scheme with sterile neutrino.
|
[
{
"created": "Wed, 15 Dec 2010 21:49:31 GMT",
"version": "v1"
}
] |
2015-05-20
|
[
[
"Yasuda",
"Osamu",
""
]
] |
Some attempts which were made to explain the MINOS anomaly are critically discussed. They include the non-standard neutral current-neutrino interaction and the (3+1)-scheme with sterile neutrino.
|
hep-ph/9509233
|
Enrico Nardi
|
Enrico Nardi
|
Top-Charm flavor changing contributions to the effective $bsZ$ vertex
|
12 pages, latex, 1 figure (uses LaTeX Routine FEYNMAN.TEX available
from hep-ph archive)
|
Phys.Lett.B365:327-333,1996
|
10.1016/0370-2693(95)01308-3
|
WIS-95/40/Aug-PH
|
hep-ph
| null |
We analyze the effects of a tree level flavor changing $tcZ$ vertex induced
by a mixing with new isosinglet $Q=2/3$ quarks, on the effective $bsZ$ vertex.
We compute the contributions arising from the new electroweak penguin diagrams
involving one insertion of the $tcZ$ vertex. We show that a generalized GIM
mechanism ensures the cancellation of the mass independent terms as well as of
the new divergences. Unexpectedly, the presence of a $tcZ$ coupling cannot
enhance the rates for the $Z$ mediated flavor changing decays \bsll\ and \bsnn,
implying that these processes cannot be used to set limits on the $tcZ$
coupling. The additional effects of the heavy isosinglets are compared with the
well studied effects of new isodoublets appearing in multi-generational models.
|
[
{
"created": "Wed, 6 Sep 1995 13:11:34 GMT",
"version": "v1"
}
] |
2014-11-17
|
[
[
"Nardi",
"Enrico",
""
]
] |
We analyze the effects of a tree level flavor changing $tcZ$ vertex induced by a mixing with new isosinglet $Q=2/3$ quarks, on the effective $bsZ$ vertex. We compute the contributions arising from the new electroweak penguin diagrams involving one insertion of the $tcZ$ vertex. We show that a generalized GIM mechanism ensures the cancellation of the mass independent terms as well as of the new divergences. Unexpectedly, the presence of a $tcZ$ coupling cannot enhance the rates for the $Z$ mediated flavor changing decays \bsll\ and \bsnn, implying that these processes cannot be used to set limits on the $tcZ$ coupling. The additional effects of the heavy isosinglets are compared with the well studied effects of new isodoublets appearing in multi-generational models.
|
hep-ph/9706248
|
Yong Jian Feng
|
Y.J. Feng, C.S. Lam (McGill University)
|
Generalized Background-Field Method
|
17 pages, Latex, 18 figures in Postscript
|
Phys.Rev. D56 (1997) 6640-6647
|
10.1103/PhysRevD.56.6640
| null |
hep-ph
| null |
The graphical method discussed previously can be used to create new gauges
not reachable by the path-integral formalism. By this means a new gauge is
designed for more efficient two-loop QCD calculations. It is related to but
simpler than the ordinary background-field gauge, in that even the triple-gluon
vertices for internal lines contain only four terms, not the usual six. This
reduction simplifies the calculation inspite of the necessity to include other
vertices for compensation. Like the ordinary background-field gauge, this
generalized background-field gauge also preserves gauge invariance of the
external particles. As a check of the result and an illustration for the
reduction in labour, an explicit calculation of the two-loop QCD
$\beta$-function is carried out in this new gauge. It results in a saving of
45% of computation compared to the ordinary background-field gauge.
|
[
{
"created": "Wed, 4 Jun 1997 14:37:09 GMT",
"version": "v1"
}
] |
2009-10-30
|
[
[
"Feng",
"Y. J.",
"",
"McGill University"
],
[
"Lam",
"C. S.",
"",
"McGill University"
]
] |
The graphical method discussed previously can be used to create new gauges not reachable by the path-integral formalism. By this means a new gauge is designed for more efficient two-loop QCD calculations. It is related to but simpler than the ordinary background-field gauge, in that even the triple-gluon vertices for internal lines contain only four terms, not the usual six. This reduction simplifies the calculation inspite of the necessity to include other vertices for compensation. Like the ordinary background-field gauge, this generalized background-field gauge also preserves gauge invariance of the external particles. As a check of the result and an illustration for the reduction in labour, an explicit calculation of the two-loop QCD $\beta$-function is carried out in this new gauge. It results in a saving of 45% of computation compared to the ordinary background-field gauge.
|
1604.07708
|
Emi Kou
|
E. Kou, A. Le Yaouanc and A. Tayduganov
|
Angular analysis of B -> J/psi K1 : towards a model independent
determination of the photon polarization with B-> K1 gamma
|
12 pages, 1 figure
| null |
10.1016/j.physletb.2016.10.013
|
LAL-16-010, LPT-Orsay-16-29
|
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We propose a model independent extraction of the hadronic information needed
to determine the photon polarization of the b-> s gamma process by the method
utilizing the B -> K1 gamma -> K pi pi gamma angular distribution. We show that
exactly the same hadronic information can be obtained by using the B -> J/psi
K1 -> J/psi K pi pi channel, which leads to a much higher precision.
|
[
{
"created": "Tue, 26 Apr 2016 15:04:26 GMT",
"version": "v1"
}
] |
2016-10-19
|
[
[
"Kou",
"E.",
""
],
[
"Yaouanc",
"A. Le",
""
],
[
"Tayduganov",
"A.",
""
]
] |
We propose a model independent extraction of the hadronic information needed to determine the photon polarization of the b-> s gamma process by the method utilizing the B -> K1 gamma -> K pi pi gamma angular distribution. We show that exactly the same hadronic information can be obtained by using the B -> J/psi K1 -> J/psi K pi pi channel, which leads to a much higher precision.
|
1605.03178
|
Nikita Blinov
|
Nikita Blinov and Anson Hook
|
Solving the Wrong Hierarchy Problem
|
14 pages, 5 figures
|
JHEP 06 (2016) 176
|
10.1007/JHEP06(2016)176
|
SLAC-PUB-16518
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Many theories require augmenting the Standard Model with additional scalar
fields with large order one couplings. We present a new solution to the
hierarchy problem for these scalar fields. We explore parity- and
$\mathbb{Z}_2$-symmetric theories where the Standard Model Higgs potential has
two vacua. The parity or $\mathbb{Z}_2$ copy of the Higgs lives in the minimum
far from the origin while our Higgs occupies the minimum near the origin of the
potential. This approach results in a theory with multiple light scalar fields
but with only a single hierarchy problem, since the bare mass is tied to the
Higgs mass by a discrete symmetry. The new scalar does not have a new hierarchy
problem associated with it because its expectation value and mass are generated
by dimensional transmutation of the scalar quartic coupling. The location of
the second Higgs minimum is not a free parameter, but is rather a function of
the matter content of the theory. As a result, these theories are extremely
predictive. We develop this idea in the context of a solution to the strong CP
problem. We show this mechanism postdicts the top Yukawa to be within $1
\sigma$ of the currently measured value and predicts scalar color octets with
masses in the range 9-200 TeV.
|
[
{
"created": "Tue, 10 May 2016 20:00:00 GMT",
"version": "v1"
},
{
"created": "Thu, 30 Jun 2016 18:25:08 GMT",
"version": "v2"
}
] |
2016-07-01
|
[
[
"Blinov",
"Nikita",
""
],
[
"Hook",
"Anson",
""
]
] |
Many theories require augmenting the Standard Model with additional scalar fields with large order one couplings. We present a new solution to the hierarchy problem for these scalar fields. We explore parity- and $\mathbb{Z}_2$-symmetric theories where the Standard Model Higgs potential has two vacua. The parity or $\mathbb{Z}_2$ copy of the Higgs lives in the minimum far from the origin while our Higgs occupies the minimum near the origin of the potential. This approach results in a theory with multiple light scalar fields but with only a single hierarchy problem, since the bare mass is tied to the Higgs mass by a discrete symmetry. The new scalar does not have a new hierarchy problem associated with it because its expectation value and mass are generated by dimensional transmutation of the scalar quartic coupling. The location of the second Higgs minimum is not a free parameter, but is rather a function of the matter content of the theory. As a result, these theories are extremely predictive. We develop this idea in the context of a solution to the strong CP problem. We show this mechanism postdicts the top Yukawa to be within $1 \sigma$ of the currently measured value and predicts scalar color octets with masses in the range 9-200 TeV.
|
hep-ph/0303192
|
Steve King
|
T. Blazek, S. F. King and J. K. Parry
|
Global Analysis of a Supersymmetric Pati-Salam Model
|
Additional discussion of Higgs couplings. 40 pages
|
JHEP 0305 (2003) 016
|
10.1088/1126-6708/2003/05/016
| null |
hep-ph
| null |
We perform a complete global phenomenological analysis of a realistic
string-inspired model based on the supersymmetric Pati-Salam $SU(4)\times
SU(2)_L \times SU(2)_R$ gauge group supplemented by a U(1) family symmetry, and
present predictions for all observables including muon $g-2$, $\tau \to \mu
\gamma$, and the CHOOZ angle. Our analysis demonstrates the compatibility of
such a model with all laboratory data including charged fermion masses and
mixing angles, LMA MSW and atmospheric neutrino masses and mixing angles, and
$b \to s \gamma$, allowing for small deviations from third family Yukawa
unification. We show that in such models the squark and slepton masses may be
rather light compared to similar models with exact Yukawa unification.
|
[
{
"created": "Sat, 22 Mar 2003 16:17:03 GMT",
"version": "v1"
},
{
"created": "Wed, 30 Apr 2003 09:32:41 GMT",
"version": "v2"
}
] |
2009-11-10
|
[
[
"Blazek",
"T.",
""
],
[
"King",
"S. F.",
""
],
[
"Parry",
"J. K.",
""
]
] |
We perform a complete global phenomenological analysis of a realistic string-inspired model based on the supersymmetric Pati-Salam $SU(4)\times SU(2)_L \times SU(2)_R$ gauge group supplemented by a U(1) family symmetry, and present predictions for all observables including muon $g-2$, $\tau \to \mu \gamma$, and the CHOOZ angle. Our analysis demonstrates the compatibility of such a model with all laboratory data including charged fermion masses and mixing angles, LMA MSW and atmospheric neutrino masses and mixing angles, and $b \to s \gamma$, allowing for small deviations from third family Yukawa unification. We show that in such models the squark and slepton masses may be rather light compared to similar models with exact Yukawa unification.
|
1002.1597
|
Sergio Campos
|
S. D. Campos (Universidade Federal de S\~ao Carlos-Sorocaba), V. A.
Okorokov (National Research Nuclear University "MEPhI")
|
Phenomenological Analysis of $pp$ and $\bar{p}p$ Elastic Scattering
Based on Theoretical Bounds in High-Energy Physics
|
22 pages, 7 figures and 11 tables. We corrected some formulas and
results of the fitting procedure. This work present intermediate steps and
results that are not shown in the published version
|
Int. J. of Mod. Phys. A25, no. 29, 5333 (2010)
|
10.1142/S0217751X10050755
| null |
hep-ph hep-ex hep-th nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Considering the Froissart-Martin bound, Jin-Martin-Cornille bound and the
optical theorem, we propose a novel parametrization for the total cross-section
of proton-proton and antiproton-proton elastic scattering data. Using
derivative dispersion relations we obtain the real part of the elastic
scattering amplitude and thus the $\rho$ parameter. Simultaneous fits to
$\sigma_{tot}$ and $\rho$ are performed allowing very good statistical
descriptions of the available data. Furthermore, predictions to $\sigma_{tot}$
and $\rho$ at energies not used in the fit procedures are presented. For
$\sigma_{tot}$ we obtain predictions at RHIC, LHC and future HC energies.
|
[
{
"created": "Mon, 8 Feb 2010 12:57:31 GMT",
"version": "v1"
},
{
"created": "Wed, 13 Oct 2010 18:40:56 GMT",
"version": "v2"
},
{
"created": "Sun, 28 Nov 2010 11:49:05 GMT",
"version": "v3"
}
] |
2010-11-30
|
[
[
"Campos",
"S. D.",
"",
"Universidade Federal de São Carlos-Sorocaba"
],
[
"Okorokov",
"V. A.",
"",
"National Research Nuclear University \"MEPhI\""
]
] |
Considering the Froissart-Martin bound, Jin-Martin-Cornille bound and the optical theorem, we propose a novel parametrization for the total cross-section of proton-proton and antiproton-proton elastic scattering data. Using derivative dispersion relations we obtain the real part of the elastic scattering amplitude and thus the $\rho$ parameter. Simultaneous fits to $\sigma_{tot}$ and $\rho$ are performed allowing very good statistical descriptions of the available data. Furthermore, predictions to $\sigma_{tot}$ and $\rho$ at energies not used in the fit procedures are presented. For $\sigma_{tot}$ we obtain predictions at RHIC, LHC and future HC energies.
|
1102.1863
|
Eef van Beveren
|
Eef van Beveren and George Rupp
|
First indications of the existence of a 38 MeV light scalar boson
|
7 pages, 6 figures, plain LaTeX; v2: Figs.2, 3 and 4 altered. Since
many colleagues had observed difficulties in interpreting Fig.4, we have
changed it to an event distribution. Some changes in the text, in particular
in the Conclusions. Extra references added
| null | null | null |
hep-ph astro-ph.CO astro-ph.HE hep-ex nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We present evidence for the existence of a light scalar particle that most
probably couples exclusively to gluons and quarks. Theoretical and
phenomenological arguments are presented to support the existence of a light
scalar boson for confinement and quark-pair creation. Previously observed
interference effects allow to set a narrow window for the scalar's mass and
also for its flavor-mass-dependent coupling to quarks. Here, in order to find a
direct signal indicating its production, we study published BABAR data on
leptonic bottomonium decays. We observe a clear excess signal in the
invariant-mass projections of electron-positron and muon-antimuon, which may be
due to the emission of a so far unobserved scalar particle with a mass of about
38 MeV. In the process of our analysis, we also find an indication of the
existence of a bottomonium-like hybrid state at about 10.061 GeV. Further
signals might be interpreted as replicas of the light scalar, with masses
roughly two and three times as large.
|
[
{
"created": "Wed, 9 Feb 2011 13:59:27 GMT",
"version": "v1"
},
{
"created": "Wed, 13 Apr 2011 17:49:08 GMT",
"version": "v2"
}
] |
2015-03-18
|
[
[
"van Beveren",
"Eef",
""
],
[
"Rupp",
"George",
""
]
] |
We present evidence for the existence of a light scalar particle that most probably couples exclusively to gluons and quarks. Theoretical and phenomenological arguments are presented to support the existence of a light scalar boson for confinement and quark-pair creation. Previously observed interference effects allow to set a narrow window for the scalar's mass and also for its flavor-mass-dependent coupling to quarks. Here, in order to find a direct signal indicating its production, we study published BABAR data on leptonic bottomonium decays. We observe a clear excess signal in the invariant-mass projections of electron-positron and muon-antimuon, which may be due to the emission of a so far unobserved scalar particle with a mass of about 38 MeV. In the process of our analysis, we also find an indication of the existence of a bottomonium-like hybrid state at about 10.061 GeV. Further signals might be interpreted as replicas of the light scalar, with masses roughly two and three times as large.
|
hep-ph/0106269
|
A. K. Chaudhuri
|
A. K. Chaudhuri (VECC, Calcutta)
|
Transverse energy dependence of J/Psi suppression in Au+Au collisions at
RHIC energy
|
4 pages, 2 figures (revised version)
|
Phys.Lett. B527 (2002) 80-84
|
10.1016/S0370-2693(02)01163-2
| null |
hep-ph nucl-th
| null |
Prediction for transverse energy dependence of $J/\psi$ to Drell-Yan ratio in
Au+Au collisions at RHIC energy was obtained in a model which assume 100%
absorption of $J/\psi$ above a threshold density. The threshold density was
obtained by fitting the NA50 data on $J/\psi$ suppression in Pb+Pb collisions
at SPS energy. At RHIC energy, hard processes may be important. Prediction of
$J/\psi$ suppression with and without hard processes were obtained. With hard
processes included, $J/\psi$'s are strongly suppressed.
|
[
{
"created": "Mon, 25 Jun 2001 06:31:46 GMT",
"version": "v1"
},
{
"created": "Tue, 30 Oct 2001 11:42:26 GMT",
"version": "v2"
},
{
"created": "Tue, 18 Dec 2001 06:40:20 GMT",
"version": "v3"
}
] |
2009-11-07
|
[
[
"Chaudhuri",
"A. K.",
"",
"VECC, Calcutta"
]
] |
Prediction for transverse energy dependence of $J/\psi$ to Drell-Yan ratio in Au+Au collisions at RHIC energy was obtained in a model which assume 100% absorption of $J/\psi$ above a threshold density. The threshold density was obtained by fitting the NA50 data on $J/\psi$ suppression in Pb+Pb collisions at SPS energy. At RHIC energy, hard processes may be important. Prediction of $J/\psi$ suppression with and without hard processes were obtained. With hard processes included, $J/\psi$'s are strongly suppressed.
|
1106.0465
|
Takehisa Fujita
|
Takehisa Fujita and Naohiro Kanda
|
A Proposal to Measure Photon-Photon Scattering
|
7 pages, no figure
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We discuss a possibility to measure the photon-photon scattering cross
section at low energy in a theoretical standpoint. The cross section of
photon-photon scattering at low energy can be written as
$\displaystyle{{d\sigma\over d\Omega} \simeq {\alpha^4\over (12\pi)^2 \omega^2}
(3+2\cos^2\theta +\cos^4\theta)}$ with $\omega$ the energy of photon. The
magnitude of the cross section at $\omega \simeq 1$ eV should be $10^{37}$
times larger than the prediction of Heisenberg and Euler who calculated the
photon scattering by the classical picture of field theory. Due to a difficulty
of the initial condition of photon-photon reaction process, we propose to first
measure $\gamma +\gamma \rightarrow e^++e^- $ reaction at a few MeV before
measuring $\gamma +\gamma \rightarrow \gamma +\gamma $ elastic scattering.
|
[
{
"created": "Mon, 30 May 2011 09:40:46 GMT",
"version": "v1"
}
] |
2011-06-03
|
[
[
"Fujita",
"Takehisa",
""
],
[
"Kanda",
"Naohiro",
""
]
] |
We discuss a possibility to measure the photon-photon scattering cross section at low energy in a theoretical standpoint. The cross section of photon-photon scattering at low energy can be written as $\displaystyle{{d\sigma\over d\Omega} \simeq {\alpha^4\over (12\pi)^2 \omega^2} (3+2\cos^2\theta +\cos^4\theta)}$ with $\omega$ the energy of photon. The magnitude of the cross section at $\omega \simeq 1$ eV should be $10^{37}$ times larger than the prediction of Heisenberg and Euler who calculated the photon scattering by the classical picture of field theory. Due to a difficulty of the initial condition of photon-photon reaction process, we propose to first measure $\gamma +\gamma \rightarrow e^++e^- $ reaction at a few MeV before measuring $\gamma +\gamma \rightarrow \gamma +\gamma $ elastic scattering.
|
hep-ph/9702335
| null |
O.G. Tchikilev (IHEP, Protvino, Russia)
|
Multiplicity distributions in e+e- annihilation into hadrons and the
extended modified negative binomial
|
9 pages, Latex, 2 postscript figures, epsfig is used
| null | null | null |
hep-ph
| null |
It is shown that simple extension of the modified negative binomial
distribution describes negatively charged particle multiplicity distributions
in e+e- annihilation, measured in the whole phase space, as well as the
modified negative binomial.
|
[
{
"created": "Fri, 14 Feb 1997 12:34:40 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Tchikilev",
"O. G.",
"",
"IHEP, Protvino, Russia"
]
] |
It is shown that simple extension of the modified negative binomial distribution describes negatively charged particle multiplicity distributions in e+e- annihilation, measured in the whole phase space, as well as the modified negative binomial.
|
1204.2400
|
Manuel Pavon Valderrama
|
M. Pavon Valderrama
|
Power Counting and Perturbative One Pion Exchange in Heavy Meson
Molecules
|
21 pages, 1 figure
| null |
10.1103/PhysRevD.85.114037
| null |
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We discuss the possible power counting schemes that can be applied in the
effective field theory description of heavy meson molecules, such as the
X(3872) or the recently discovered Zb(10610) and Zb(10650) states. We argue
that the effect of coupled channels is suppressed by at least two orders in the
effective field theory expansion, meaning that they can be safely ignored at
lowest order. The role of the one pion exchange potential between the heavy
mesons, and in particular the tensor force, is also analyzed. By using
techniques developed in atomic physics for handling power-law singular
potentials, which have been also successfully employed in nuclear physics, we
determine the range of center-of-mass momenta for which the tensor piece of the
one pion exchange potential is perturbative. In this momentum range, the one
pion exchange potential can be considered a subleading order correction,
leaving at lowest order a very simple effective field theory consisting only on
contact-range interactions.
|
[
{
"created": "Wed, 11 Apr 2012 10:21:12 GMT",
"version": "v1"
}
] |
2015-06-04
|
[
[
"Valderrama",
"M. Pavon",
""
]
] |
We discuss the possible power counting schemes that can be applied in the effective field theory description of heavy meson molecules, such as the X(3872) or the recently discovered Zb(10610) and Zb(10650) states. We argue that the effect of coupled channels is suppressed by at least two orders in the effective field theory expansion, meaning that they can be safely ignored at lowest order. The role of the one pion exchange potential between the heavy mesons, and in particular the tensor force, is also analyzed. By using techniques developed in atomic physics for handling power-law singular potentials, which have been also successfully employed in nuclear physics, we determine the range of center-of-mass momenta for which the tensor piece of the one pion exchange potential is perturbative. In this momentum range, the one pion exchange potential can be considered a subleading order correction, leaving at lowest order a very simple effective field theory consisting only on contact-range interactions.
|
0704.2368
|
Nikolay Achasov
|
N. N. Achasov and G. N. Shestakov
|
Lightest scalar in the SU_L(2)*SU_R(2) linear \sigma model
|
10 pages, 3 figures, English improved, PACS numbers changed, two
Refs. added, E-mail addresses removed and Ref. [1] shortened for the overrun
of the article length allowable in Phys. Rev. Lett
|
Phys.Rev.Lett.99:072001,2007
|
10.1103/PhysRevLett.99.072001
| null |
hep-ph hep-ex nucl-th
| null |
We consider the lightest scalar meson in the frame of the $SU_L(2)\times
SU_R(2)$ linear $\sigma$ model, keeping in mind that this model could be the
low energy realization of the two-flavour QCD. We show that the $\sigma$ field
is described by its four-quark component at least in the $\sigma$ resonance
energy (virtuality) region and the $\sigma\to\gamma\gamma$ decay is the four
quark transition.
We emphasize that residues of the $\sigma$ pole in the $\pi\pi\to\pi\pi$ and
$\gamma\gamma\to\pi\pi$ amplitudes do not give an idea about the $\sigma$ meson
nature, and the progress in studying the $\sigma$ meson production mechanisms
in different processes could essentially further us in understanding its
nature.
|
[
{
"created": "Wed, 18 Apr 2007 15:39:18 GMT",
"version": "v1"
},
{
"created": "Sat, 18 Aug 2007 07:14:39 GMT",
"version": "v2"
}
] |
2008-11-26
|
[
[
"Achasov",
"N. N.",
""
],
[
"Shestakov",
"G. N.",
""
]
] |
We consider the lightest scalar meson in the frame of the $SU_L(2)\times SU_R(2)$ linear $\sigma$ model, keeping in mind that this model could be the low energy realization of the two-flavour QCD. We show that the $\sigma$ field is described by its four-quark component at least in the $\sigma$ resonance energy (virtuality) region and the $\sigma\to\gamma\gamma$ decay is the four quark transition. We emphasize that residues of the $\sigma$ pole in the $\pi\pi\to\pi\pi$ and $\gamma\gamma\to\pi\pi$ amplitudes do not give an idea about the $\sigma$ meson nature, and the progress in studying the $\sigma$ meson production mechanisms in different processes could essentially further us in understanding its nature.
|
hep-ph/0102235
|
Francesco Vissani
|
Francesco Vissani (Gran Sasso)
|
Is a Coherent Picture of Massive Neutrinos Emerging?
|
2 pages, ws-p9-75x6-50.cls file included. To appear in the
"Proceedings of the 9th Marcel Grossmann Meeting", Rome, Jul 2000, Session
AP5 (Experimental Status of Neutrino Mixing)
| null |
10.1142/9789812777386_0597
| null |
hep-ph
| null |
The hypothesis that neutrinos are massive has a strong experimental support;
however, the information we have is quite limited, and many possibilities are
open. Theoretical considerations might help fill the gaps (or foresee
regularities), as we illustrate with a specific example.
|
[
{
"created": "Mon, 19 Feb 2001 17:38:33 GMT",
"version": "v1"
}
] |
2017-08-23
|
[
[
"Vissani",
"Francesco",
"",
"Gran Sasso"
]
] |
The hypothesis that neutrinos are massive has a strong experimental support; however, the information we have is quite limited, and many possibilities are open. Theoretical considerations might help fill the gaps (or foresee regularities), as we illustrate with a specific example.
|
hep-ph/9908222
|
Ed Stoeffhaas
|
M.M. Block, F. Halzen, and T. Stanev
|
Predicting Proton-Air Cross Sections at sqrt s ~30 TeV, using
Accelerator and Cosmic Ray Data
|
9 pages, Revtex, uses epsfig.sty, 5 postscript figures. Minor text
revisions. Systematic errors in k included, procedure for extracting k
clarified. Previously undefined symbols now defined
|
Phys.Rev.Lett.83:4926-4928,1999
|
10.1103/PhysRevLett.83.4926
|
MADPH-99-1132, NUHEP 602, BA-99-56
|
hep-ph astro-ph
| null |
We use the high energy predictions of a QCD-inspired parameterization of all
accelerator data on forward proton-proton and antiproton-proton scattering
amplitudes, along with Glauber theory, to predict proton-air cross sections at
energies near \sqrt s \approx 30 TeV. The parameterization of the proton-proton
cross section incorporates analyticity and unitarity, and demands that the
asymptotic proton is a black disk of soft partons. By comparing with the p-air
cosmic ray measurements, our analysis results in a constraint on the inclusive
particle production cross section.
|
[
{
"created": "Mon, 2 Aug 1999 20:58:40 GMT",
"version": "v1"
},
{
"created": "Tue, 5 Oct 1999 21:28:24 GMT",
"version": "v2"
}
] |
2011-05-12
|
[
[
"Block",
"M. M.",
""
],
[
"Halzen",
"F.",
""
],
[
"Stanev",
"T.",
""
]
] |
We use the high energy predictions of a QCD-inspired parameterization of all accelerator data on forward proton-proton and antiproton-proton scattering amplitudes, along with Glauber theory, to predict proton-air cross sections at energies near \sqrt s \approx 30 TeV. The parameterization of the proton-proton cross section incorporates analyticity and unitarity, and demands that the asymptotic proton is a black disk of soft partons. By comparing with the p-air cosmic ray measurements, our analysis results in a constraint on the inclusive particle production cross section.
|
0705.3075
|
Tatsuo Kobayashi
|
Takeshi Araki, Kang-Sin Choi, Tatsuo Kobayashi, Jisuke Kubo and
Hiroshi Ohki
|
Discrete R-symmetry anomalies in heterotic orbifold models
|
19 pages, no figure
|
Phys.Rev.D76:066006,2007
|
10.1103/PhysRevD.76.066006
| null |
hep-ph hep-th
| null |
Anomalies of discrete R-symmetries appearing in heterotic orbifold models are
studied. We find that the mixed anomalies for different gauge groups satisfy
the universal Green-Schwarz (GS) condition, indicating that these anomalies are
canceled by the GS mechanism. An exact relation between the anomaly
coefficients of the discrete R-symmetries and one-loop beta-function
coefficients is obtained. We also find that the discrete R-symmetries have a
good chance to be unbroken down to the supersymmetry breaking scale. Even below
this scale a $Z_2$ subgroup is unbroken, which may be an origin of the R-parity
of the minimal supersymmetric standard model. Relations between the R-symmetry
anomalies and T-duality anomalies are also investigated.
|
[
{
"created": "Tue, 22 May 2007 00:43:50 GMT",
"version": "v1"
},
{
"created": "Tue, 29 May 2007 23:57:36 GMT",
"version": "v2"
},
{
"created": "Mon, 23 Jul 2007 00:47:56 GMT",
"version": "v3"
}
] |
2008-11-26
|
[
[
"Araki",
"Takeshi",
""
],
[
"Choi",
"Kang-Sin",
""
],
[
"Kobayashi",
"Tatsuo",
""
],
[
"Kubo",
"Jisuke",
""
],
[
"Ohki",
"Hiroshi",
""
]
] |
Anomalies of discrete R-symmetries appearing in heterotic orbifold models are studied. We find that the mixed anomalies for different gauge groups satisfy the universal Green-Schwarz (GS) condition, indicating that these anomalies are canceled by the GS mechanism. An exact relation between the anomaly coefficients of the discrete R-symmetries and one-loop beta-function coefficients is obtained. We also find that the discrete R-symmetries have a good chance to be unbroken down to the supersymmetry breaking scale. Even below this scale a $Z_2$ subgroup is unbroken, which may be an origin of the R-parity of the minimal supersymmetric standard model. Relations between the R-symmetry anomalies and T-duality anomalies are also investigated.
|
1807.00832
|
Andrew Spray
|
Yi Cai, Andrew Spray
|
Low-Temperature Enhancement of Semi-annihilation and the AMS-02 Positron
Anomaly
|
32 pages, 5 figures; minor updates
| null |
10.1007/JHEP10(2018)075
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Semi-annihilation is a generic feature of particle dark matter that is most
easily probed by cosmic ray experiments. We explore models where the
semi-annihilation cross section is enhanced at late times and low temperatures
by the presence of an s-channel resonance near threshold. The relic density is
then sensitive to the evolution of the dark matter temperature, and we compute
expressions for the associated Boltzmann equation valid in general
semi-annihilating models. At late times, a self-heating effect warms the dark
matter, allowing number-changing processes to remain effective long after
kinetic decoupling of the dark and visible sectors. This allows the
semi-annihilation signal today to be enhanced by up to five orders of magnitude
over the thermal relic cross section. As a case study, we apply this to a dark
matter explanation of the positron excess seen by AMS-02. We see that unlike
annihilating dark matter, our model has no difficulty fitting the data while
also giving the correct relic density. However, constraints from the CMB and
$\gamma$-rays from the galactic centre do restrict the preferred regions of
parameter space.
|
[
{
"created": "Mon, 2 Jul 2018 18:00:07 GMT",
"version": "v1"
},
{
"created": "Thu, 19 Jul 2018 14:59:01 GMT",
"version": "v2"
}
] |
2018-11-14
|
[
[
"Cai",
"Yi",
""
],
[
"Spray",
"Andrew",
""
]
] |
Semi-annihilation is a generic feature of particle dark matter that is most easily probed by cosmic ray experiments. We explore models where the semi-annihilation cross section is enhanced at late times and low temperatures by the presence of an s-channel resonance near threshold. The relic density is then sensitive to the evolution of the dark matter temperature, and we compute expressions for the associated Boltzmann equation valid in general semi-annihilating models. At late times, a self-heating effect warms the dark matter, allowing number-changing processes to remain effective long after kinetic decoupling of the dark and visible sectors. This allows the semi-annihilation signal today to be enhanced by up to five orders of magnitude over the thermal relic cross section. As a case study, we apply this to a dark matter explanation of the positron excess seen by AMS-02. We see that unlike annihilating dark matter, our model has no difficulty fitting the data while also giving the correct relic density. However, constraints from the CMB and $\gamma$-rays from the galactic centre do restrict the preferred regions of parameter space.
|
hep-ph/0004122
|
Heinrich Paes
|
H.V. Klapdor-Kleingrothaus, H. P\"as and U. Sarkar
|
Confronting Dilaton-exchange gravity with experiments
|
7 pages
|
Phys.Lett. B488 (2000) 398-401
|
10.1016/S0370-2693(00)00882-0
| null |
hep-ph gr-qc
| null |
We study the experimental constraints on theories, where the equivalence
principle is violated by dilaton-exchange contributions to the usual
graviton-exchange gravity. We point out that in this case it is not possible to
have any CPT violation and hence there is no constraint from the CPT violating
measurements in the $K-$system. The most stringent bound is obtained from the
$K_L - K_S$ mass difference. In contrast, neither neutrino oscillation
experiments nor neutrinoless double beta decay imply significant constraints.
|
[
{
"created": "Thu, 13 Apr 2000 16:36:10 GMT",
"version": "v1"
},
{
"created": "Wed, 16 Aug 2000 15:45:48 GMT",
"version": "v2"
}
] |
2009-10-31
|
[
[
"Klapdor-Kleingrothaus",
"H. V.",
""
],
[
"Päs",
"H.",
""
],
[
"Sarkar",
"U.",
""
]
] |
We study the experimental constraints on theories, where the equivalence principle is violated by dilaton-exchange contributions to the usual graviton-exchange gravity. We point out that in this case it is not possible to have any CPT violation and hence there is no constraint from the CPT violating measurements in the $K-$system. The most stringent bound is obtained from the $K_L - K_S$ mass difference. In contrast, neither neutrino oscillation experiments nor neutrinoless double beta decay imply significant constraints.
|
2003.10770
|
Denny Lane Sombillo
|
Denny Lane B. Sombillo, Yoichi Ikeda, Toru Sato and Atsushi Hosaka
|
Classifying Pole of Amplitude Using Deep Neural Network
|
11 pages, 10 figures
|
Phys. Rev. D 102, 016024 (2020)
|
10.1103/PhysRevD.102.016024
| null |
hep-ph hep-ex nucl-ex nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Most of exotic resonances observed in the past decade appear as peak
structure near some threshold. These near-threshold phenomena can be
interpreted as genuine resonant states or enhanced threshold cusps. Apparently,
there is no straightforward way of distinguishing the two structures. In this
work, we employ the strength of deep feed-forward neural network in classifying
objects with almost similar features. We construct a neural network model with
scattering amplitude as input and nature of pole causing the enhancement as
output. The training data is generated by an S-matrix satisfying the unitarity
and analyticity requirements. Using the separable potential model, we generate
a validation data set to measure the network's predictive power. We find that
our trained neural network model gives high accuracy when the cut-off parameter
of the validation data is within $400$-$800\mbox{ MeV}$. As a final test, we
use the Nijmegen partial wave and potential models for nucleon-nucleon
scattering and show that the network gives the correct nature of pole.
|
[
{
"created": "Tue, 24 Mar 2020 11:11:23 GMT",
"version": "v1"
},
{
"created": "Fri, 10 Jul 2020 08:08:02 GMT",
"version": "v2"
}
] |
2020-08-05
|
[
[
"Sombillo",
"Denny Lane B.",
""
],
[
"Ikeda",
"Yoichi",
""
],
[
"Sato",
"Toru",
""
],
[
"Hosaka",
"Atsushi",
""
]
] |
Most of exotic resonances observed in the past decade appear as peak structure near some threshold. These near-threshold phenomena can be interpreted as genuine resonant states or enhanced threshold cusps. Apparently, there is no straightforward way of distinguishing the two structures. In this work, we employ the strength of deep feed-forward neural network in classifying objects with almost similar features. We construct a neural network model with scattering amplitude as input and nature of pole causing the enhancement as output. The training data is generated by an S-matrix satisfying the unitarity and analyticity requirements. Using the separable potential model, we generate a validation data set to measure the network's predictive power. We find that our trained neural network model gives high accuracy when the cut-off parameter of the validation data is within $400$-$800\mbox{ MeV}$. As a final test, we use the Nijmegen partial wave and potential models for nucleon-nucleon scattering and show that the network gives the correct nature of pole.
|
0902.3166
|
Hubert Spiesberger
|
B. A. Kniehl, G. Kramer, I. Schienbein, and H. Spiesberger
|
Inclusive photoproduction of D*+- mesons at next-to-leading order in the
General-Mass Variable-Flavor-Number Scheme
|
18 pages
|
Eur.Phys.J.C62:365-374,2009
|
10.1140/epjc/s10052-009-1027-x
|
DESY 08-204, LPSC 09-27, MZ-TH/08-40
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We discuss the inclusive production of D*+- mesons in gamma-proton collisions
at DESY HERA, based on a calculation at next-to-leading order in the
general-mass variable-flavor-number scheme. In this approach, MSbar subtraction
is applied in such a way that large logarithmic corrections are resummed in
universal parton distribution and fragmentation functions and finite mass terms
are taken into account. We present detailed numerical results for a comparison
with data obtained at HERA and discuss various sources of theoretical
uncertainties.
|
[
{
"created": "Wed, 18 Feb 2009 15:28:57 GMT",
"version": "v1"
}
] |
2009-07-24
|
[
[
"Kniehl",
"B. A.",
""
],
[
"Kramer",
"G.",
""
],
[
"Schienbein",
"I.",
""
],
[
"Spiesberger",
"H.",
""
]
] |
We discuss the inclusive production of D*+- mesons in gamma-proton collisions at DESY HERA, based on a calculation at next-to-leading order in the general-mass variable-flavor-number scheme. In this approach, MSbar subtraction is applied in such a way that large logarithmic corrections are resummed in universal parton distribution and fragmentation functions and finite mass terms are taken into account. We present detailed numerical results for a comparison with data obtained at HERA and discuss various sources of theoretical uncertainties.
|
1305.0584
|
Dmitry Zhuridov Dr.
|
Kristopher J. Healey, Alexey A. Petrov and Dmitry Zhuridov
|
Nonstandard neutrino interactions and transition magnetic moments
|
7 pages, 1 figure, 1 table; the entries in the central column of
Table I are corrected by the factor of 2, and a misprint in Eq. (17) is
corrected
|
Phys. Rev. D 87 (2013) 117301; Phys. Rev. D 89 (2014) 059904
|
10.1103/PhysRevD.87.117301; 10.1103/PhysRevD.89.059904
|
WSU--HEP--1305
|
hep-ph hep-ex nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We constrain generic nonstandard neutrino interactions with existing
experimental data on neutrino transition magnetic moments and derive strong
bounds on tensorial couplings of neutrinos to charged fermions. We also discuss
how some of these tensorial couplings can be constrained by other experiments,
e.g., on neutrino-electron and neutrino-nucleus scattering.
|
[
{
"created": "Thu, 2 May 2013 21:48:21 GMT",
"version": "v1"
},
{
"created": "Mon, 17 Jun 2013 16:02:53 GMT",
"version": "v2"
},
{
"created": "Mon, 3 Mar 2014 18:37:46 GMT",
"version": "v3"
}
] |
2014-04-24
|
[
[
"Healey",
"Kristopher J.",
""
],
[
"Petrov",
"Alexey A.",
""
],
[
"Zhuridov",
"Dmitry",
""
]
] |
We constrain generic nonstandard neutrino interactions with existing experimental data on neutrino transition magnetic moments and derive strong bounds on tensorial couplings of neutrinos to charged fermions. We also discuss how some of these tensorial couplings can be constrained by other experiments, e.g., on neutrino-electron and neutrino-nucleus scattering.
|
2108.01046
|
M. Gabriel Santiago
|
M. Gabriel Santiago
|
Quark Sivers Function at Small-$x$: Leading contribution from the
Spin-Dependent Odderon
|
6 pages, 2 figures, contribution to the proceedings of the XXVIII
International Workshop on Deep Inelastic Scattering and Related Subjects
(DIS2021), Stony Brook, New York, USA, 12-16 April, 2021, for submission to
SciPost Physics Proceedings
| null | null | null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
We present the calculation of the leading contribution to the quark Sivers
function at small-Bjorken $x$. This calculation uses the high energy scattering
approximation and operator formalism developed by Kovchegov and Sievert to
obtain a dominant contribution to the quark Sivers function coming from the
spin-dependent odderon, in agreement with the results of Dong, Zhen, and Zhou.
We then calculate this dominant contribution in the diquark model of the proton
to obtain a small-$x$ estimate for the Sivers function.
|
[
{
"created": "Mon, 2 Aug 2021 17:10:18 GMT",
"version": "v1"
}
] |
2021-08-03
|
[
[
"Santiago",
"M. Gabriel",
""
]
] |
We present the calculation of the leading contribution to the quark Sivers function at small-Bjorken $x$. This calculation uses the high energy scattering approximation and operator formalism developed by Kovchegov and Sievert to obtain a dominant contribution to the quark Sivers function coming from the spin-dependent odderon, in agreement with the results of Dong, Zhen, and Zhou. We then calculate this dominant contribution in the diquark model of the proton to obtain a small-$x$ estimate for the Sivers function.
|
2005.07512
|
George Lazarides
|
George Lazarides
|
Particles and the Universe
|
23 pages, talk presented in the "Corfu Summer Institute 2019: School
and Workshops on Elementary Particle Physics and Gravity (CORFU2019)", 31
August - 25 September 2019, Corfu, Greece, to appear in the proceedings.
arXiv admin note: text overlap with arXiv:hep-ph/0607032,
arXiv:hep-ph/0204294, arXiv:hep-ph/0111328
| null | null |
UT-STPD-20/02
|
hep-ph astro-ph.CO
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The early stages of the universe evolution are discussed according to the hot
big bang model and the grand unified theories. The shortcomings of big bang are
summarized and their resolution by inflationary cosmology is sketched.
Cosmological inflation, the subsequent oscillation and decay of the inflaton
field, and the resulting reheating of the universe are studied in some detail.
The density perturbations produced by inflation and the temperature
fluctuations of the cosmic microwave background radiation are introduced.
Baryogenesis via non-thermal leptogenesis is analyzed and dark energy and
matter in the universe are presented. Quantum gravity and string theory are
very briefly introduced. The problem of initial conditions for inflation is
discussed in the light of string theory and the possibly detectable primordial
gravity waves from inflation are mentioned.
|
[
{
"created": "Thu, 14 May 2020 15:59:43 GMT",
"version": "v1"
}
] |
2020-05-18
|
[
[
"Lazarides",
"George",
""
]
] |
The early stages of the universe evolution are discussed according to the hot big bang model and the grand unified theories. The shortcomings of big bang are summarized and their resolution by inflationary cosmology is sketched. Cosmological inflation, the subsequent oscillation and decay of the inflaton field, and the resulting reheating of the universe are studied in some detail. The density perturbations produced by inflation and the temperature fluctuations of the cosmic microwave background radiation are introduced. Baryogenesis via non-thermal leptogenesis is analyzed and dark energy and matter in the universe are presented. Quantum gravity and string theory are very briefly introduced. The problem of initial conditions for inflation is discussed in the light of string theory and the possibly detectable primordial gravity waves from inflation are mentioned.
|
1307.6653
|
Rupak Dutta
|
Rupak Dutta, Anupama Bhol, Anjan K Giri
|
Effective theory approach to new physics in $b \to u$ and $b \to c$
leptonic and semileptonic decays
|
32 pages, 8 figures, published version
|
Phys. Rev. D 88, 114023 (2013)
|
10.1103/PhysRevD.88.114023
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Recent measurements of exclusive $B^{-} \to \tau^{-}\,\nu$ and $B^0 \to
\pi^{+}\,l^{-}\,\bar{\nu}_l$ decays via the $b \to u\,l\,\nu$ transition
process differ from the standard model expectation and, if they persist in
future $B$ experiments, will be a definite hint of the physics beyond the
standard model. Similar hints of new physics have been observed in $b \to c$
semileptonic transition processes as well. BABAR measures the ratio of
branching fractions of $B \to (D,\,D^{\ast})\,\tau\,\nu$ to the corresponding
$B \to (D,\,D^{\ast})\,l\nu$, where $l$ represents either an electron or a
muon, and finds $3.4\sigma$ discrepancy with the standard model expectation. In
this context, we consider a most general effective Lagrangian for the $b \to
u\,l\,\nu$ and $b \to c\,l\,\nu$ transition processes in the presence of new
physics and perform a combined analysis of all the $b \to u$ and $b \to c$
semi-(leptonic) data to explore various new physics operators and their
couplings. We consider various new physics scenarios and give predictions for
the $B_c \to \tau\nu$ and $B \to \pi\tau\nu$ decay branching fractions. We also
study the effect of these new physics parameters on the ratio of the branching
ratios of $B \to \pi\tau\nu$ to the corresponding $B \to \pi\,l\,\nu$ decays.
|
[
{
"created": "Thu, 25 Jul 2013 07:59:42 GMT",
"version": "v1"
},
{
"created": "Thu, 26 Dec 2013 18:00:41 GMT",
"version": "v2"
}
] |
2013-12-30
|
[
[
"Dutta",
"Rupak",
""
],
[
"Bhol",
"Anupama",
""
],
[
"Giri",
"Anjan K",
""
]
] |
Recent measurements of exclusive $B^{-} \to \tau^{-}\,\nu$ and $B^0 \to \pi^{+}\,l^{-}\,\bar{\nu}_l$ decays via the $b \to u\,l\,\nu$ transition process differ from the standard model expectation and, if they persist in future $B$ experiments, will be a definite hint of the physics beyond the standard model. Similar hints of new physics have been observed in $b \to c$ semileptonic transition processes as well. BABAR measures the ratio of branching fractions of $B \to (D,\,D^{\ast})\,\tau\,\nu$ to the corresponding $B \to (D,\,D^{\ast})\,l\nu$, where $l$ represents either an electron or a muon, and finds $3.4\sigma$ discrepancy with the standard model expectation. In this context, we consider a most general effective Lagrangian for the $b \to u\,l\,\nu$ and $b \to c\,l\,\nu$ transition processes in the presence of new physics and perform a combined analysis of all the $b \to u$ and $b \to c$ semi-(leptonic) data to explore various new physics operators and their couplings. We consider various new physics scenarios and give predictions for the $B_c \to \tau\nu$ and $B \to \pi\tau\nu$ decay branching fractions. We also study the effect of these new physics parameters on the ratio of the branching ratios of $B \to \pi\tau\nu$ to the corresponding $B \to \pi\,l\,\nu$ decays.
|
hep-ph/0201029
|
Prashant Shukla
|
P. Shukla and A. K. Mohanty
|
Spinodal decomposition: An alternate mechanism of phase conversion
|
LaTeX, 4 pages with 3 Postscript figures. Talk given at International
Conference on Physics and Astrophysics of Quark Gluon Plasma (ICPAQGP 2001),
Nov. 26-30, 2001, Jaipur, India
|
Pramana60:1117-1120,2002
|
10.1007/BF02707042
| null |
hep-ph
| null |
The scenario of homogeneous nucleation is investigated for a first order
quark-hadron phase transition in a rapidly expanding background of quark gluon
plasma. It is found that significant supercooling is possible before
hadronization begins. This study also suggests that spinodal decomposition
competes with nucleation and may provide an alternative mechanism for phase
conversion.
|
[
{
"created": "Sun, 6 Jan 2002 09:30:07 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Shukla",
"P.",
""
],
[
"Mohanty",
"A. K.",
""
]
] |
The scenario of homogeneous nucleation is investigated for a first order quark-hadron phase transition in a rapidly expanding background of quark gluon plasma. It is found that significant supercooling is possible before hadronization begins. This study also suggests that spinodal decomposition competes with nucleation and may provide an alternative mechanism for phase conversion.
|
1210.2547
|
Andrea Mammarella
|
Andrea Mammarella
|
Anomalous U(1) and Asymmetry
|
5 pages, 8 figures, proceeding of the YRMR 2012 conference
|
2012 J. Phys.: Conf. Ser. 383 012002
|
10.1088/1742-6596/383/1/012002
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In the past years many possible extensions of the Standard Model (SM) have
been investigated. If one of this model is revealed at the LHC, we will need
tools to distinguish it among the many others studied. One possibility to
achieve this goal is to utilize the forward-backward asymmetry. In this paper
we calculate the asymmetry for a model in which there is an extra U(1)
anomalous symmetry. Furthermore, we show that the asymmetry can be used to
impose constraints on the free parameters of the model.
|
[
{
"created": "Tue, 9 Oct 2012 10:14:45 GMT",
"version": "v1"
}
] |
2013-02-08
|
[
[
"Mammarella",
"Andrea",
""
]
] |
In the past years many possible extensions of the Standard Model (SM) have been investigated. If one of this model is revealed at the LHC, we will need tools to distinguish it among the many others studied. One possibility to achieve this goal is to utilize the forward-backward asymmetry. In this paper we calculate the asymmetry for a model in which there is an extra U(1) anomalous symmetry. Furthermore, we show that the asymmetry can be used to impose constraints on the free parameters of the model.
|
1008.4756
|
Wojciech Krolikowski
|
Wojciech Krolikowski (Warsaw University)
|
Photoproduction of sterile scalars from cold dark matter through the
photonic portal
|
9 pages
| null | null |
IFT-10/8
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Operating with the recently proposed model of hidden sector of the Universe,
based on the idea of photonic portal, we consider a new possible astrophysical
process of weak photoproduction of sterile scalars from the cold dark matter
consisting of sterile Dirac fermions. Subsequently, these scalars weakly decay
into secondary couples of photons. Then, primary photons, if energetic enough
and interacting in sufficiently dense dark-matter configurations, may form
secondary-photon cascades appearing as a new astrophysical phenomenon. Primary
photons, probing the cold dark matter, may come e.g. from gamma bursts. We show
how the cross-section for the photoproduction and the rate for the decay can be
calculated (in the centre-of-mass frame and at rest, respectively, for
simplicity).
|
[
{
"created": "Thu, 26 Aug 2010 09:10:11 GMT",
"version": "v1"
}
] |
2010-08-30
|
[
[
"Krolikowski",
"Wojciech",
"",
"Warsaw University"
]
] |
Operating with the recently proposed model of hidden sector of the Universe, based on the idea of photonic portal, we consider a new possible astrophysical process of weak photoproduction of sterile scalars from the cold dark matter consisting of sterile Dirac fermions. Subsequently, these scalars weakly decay into secondary couples of photons. Then, primary photons, if energetic enough and interacting in sufficiently dense dark-matter configurations, may form secondary-photon cascades appearing as a new astrophysical phenomenon. Primary photons, probing the cold dark matter, may come e.g. from gamma bursts. We show how the cross-section for the photoproduction and the rate for the decay can be calculated (in the centre-of-mass frame and at rest, respectively, for simplicity).
|
hep-ph/9606461
|
Otto Kong
|
Otto C.W. Kong (UNC-Chapel Hill)
|
A New Approach to the Family Structure
|
substantially rewritten to incorporate more results; has notation
changes and new references
|
Mod.Phys.Lett. A11 (1996) 2547-2554
|
10.1142/S0217732396002551
|
IFP-728-UNC
|
hep-ph
| null |
In this letter, we introduce a new approach to formulate the family structure
of the standard model. Trying to mimic the highly contrained representation
structure of the standard model while extending the symmetry, we propose a
$SU(4)\otimes SU(3)\otimes SU(2)\otimes U(1)$ symmetry with a SM-like chiral
spectra basically "derived" from the gauge anomaly constraints. Embedding the
SM leads to $SU(4)_A\otimes SU(3)_C\otimes SU(2)_L\otimes U(1)_X$ models, which
upon the $SU(4)_A\otimes U(1)_X \longrightarrow U(1)_Y$ symmetry breaking,
gives the three families naturally as a result. A specific model obtained from
the approach is illustrated. The model, or others from our approach, holds
promise of a very interesting phenomenology. We sketch some of the results
here. An interesting possiblity of supersymmetrizing the model with the
EW-Higgses already in the spectrum is noted. A comparison with other approaches
is also discussed.
|
[
{
"created": "Fri, 28 Jun 1996 00:06:18 GMT",
"version": "v1"
},
{
"created": "Thu, 8 Aug 1996 22:52:22 GMT",
"version": "v2"
}
] |
2009-10-28
|
[
[
"Kong",
"Otto C. W.",
"",
"UNC-Chapel Hill"
]
] |
In this letter, we introduce a new approach to formulate the family structure of the standard model. Trying to mimic the highly contrained representation structure of the standard model while extending the symmetry, we propose a $SU(4)\otimes SU(3)\otimes SU(2)\otimes U(1)$ symmetry with a SM-like chiral spectra basically "derived" from the gauge anomaly constraints. Embedding the SM leads to $SU(4)_A\otimes SU(3)_C\otimes SU(2)_L\otimes U(1)_X$ models, which upon the $SU(4)_A\otimes U(1)_X \longrightarrow U(1)_Y$ symmetry breaking, gives the three families naturally as a result. A specific model obtained from the approach is illustrated. The model, or others from our approach, holds promise of a very interesting phenomenology. We sketch some of the results here. An interesting possiblity of supersymmetrizing the model with the EW-Higgses already in the spectrum is noted. A comparison with other approaches is also discussed.
|
1612.08524
|
Michael Gronau
|
Michael Gronau and Jonathan L. Rosner
|
Controlling $\rho$ width effects for a precise value of $\alpha$ in $B
\to \rho \rho$
|
to be published in Physics Letters B
| null |
10.1016/j.physletb.2017.01.022
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
It has been pointed out that the currently most precise determination of the
weak phase $\phi_2 = \alpha$ of the Cabibbo-Kobayashi-Maskawa (CKM) matrix
achieved in $B \to \rho\rho$ decays is susceptible to a small correction at a
level of $(\Gamma_\rho/m_\rho)^2$ due to an $I=1$ amplitude caused by the
$\rho$ width. Using Breit-Wigner distributions for the two pairs of pions
forming $\rho$ mesons, we study the $I=1$ contribution to $B\to \rho\rho$ decay
rates as function of the width and location of the $\rho$ band. We find that in
the absence of a particular enhancement of the $I=1$ amplitude reducing a
single band to a width $\Gamma_\rho$ at SuperKEKB leads to results which are
completely insensitive to the $\rho$ width. If the $I=1$ amplitude is
dynamically enhanced relative to the $I=0,2$ amplitude one could subject its
contribution to a "magnifying glass" measurement using two separated $\rho$
bands of width $\Gamma_\rho$. Subtraction of the $I=1$ contribution from the
measured decay rate would lead to a very precise determination of the $I=0,2$
amplitude needed for performing the isospin analysis.
|
[
{
"created": "Tue, 27 Dec 2016 07:46:26 GMT",
"version": "v1"
},
{
"created": "Wed, 4 Jan 2017 12:49:02 GMT",
"version": "v2"
},
{
"created": "Fri, 3 Feb 2017 06:46:08 GMT",
"version": "v3"
}
] |
2017-02-06
|
[
[
"Gronau",
"Michael",
""
],
[
"Rosner",
"Jonathan L.",
""
]
] |
It has been pointed out that the currently most precise determination of the weak phase $\phi_2 = \alpha$ of the Cabibbo-Kobayashi-Maskawa (CKM) matrix achieved in $B \to \rho\rho$ decays is susceptible to a small correction at a level of $(\Gamma_\rho/m_\rho)^2$ due to an $I=1$ amplitude caused by the $\rho$ width. Using Breit-Wigner distributions for the two pairs of pions forming $\rho$ mesons, we study the $I=1$ contribution to $B\to \rho\rho$ decay rates as function of the width and location of the $\rho$ band. We find that in the absence of a particular enhancement of the $I=1$ amplitude reducing a single band to a width $\Gamma_\rho$ at SuperKEKB leads to results which are completely insensitive to the $\rho$ width. If the $I=1$ amplitude is dynamically enhanced relative to the $I=0,2$ amplitude one could subject its contribution to a "magnifying glass" measurement using two separated $\rho$ bands of width $\Gamma_\rho$. Subtraction of the $I=1$ contribution from the measured decay rate would lead to a very precise determination of the $I=0,2$ amplitude needed for performing the isospin analysis.
|
hep-ph/9312231
|
Seiji Matsumoto
|
K.Hagiwara, S.Matsumoto, and C.S.Kim
|
Electroweak Radiative Corrections
|
Plenary talk K. Hagiwara at the 14'th International Workshop on Weak
Interactions and Neutrinos (revised); 25 pages, LaTeX KEK-TH-369, SNUTP
93-50, YUMS 93-19, KEK preprint 93-108
| null | null | null |
hep-ph
| null |
A new framework to study electroweak physics at one-loop level in general
${\rm SU(2)_L \times U(1)_Y}$ theories is introduced. It separates the 1-loop
corrections into two pieces: process specific ones from vertex and box
contributions and the universal ones due to contributions to the gauge boson
propagators. The latter are parametrized in terms of four effective form
factors, $\bar{e}^2(q^2)$, $\bar{s}^2(q^2)$, $\bar{g}_Z^2(q^2)$, and
$\bar{g}_W^2(q^2)$, correspondingly to $\gamma\gamma$, $\gamma Z$, $ZZ$, and
$WW$ propagators. By assuming only the standard model contributions to the
process specific corrections, the magnitudes of the four form factors are
determined at $q^2=0$ and at $q^2=m_Z^2$ from all available precision
experiments. These values are then compared systematically with the predictions
of the ${\rm SU(2)_L \times U(1)_Y}$ theories. No deviation from the standard
model has been identified. Plausible range of the top quark mass is then
obtained for a given Higgs boson mass and $\alpha_s$ .
|
[
{
"created": "Tue, 7 Dec 1993 07:27:56 GMT",
"version": "v1"
},
{
"created": "Wed, 22 Dec 1993 15:54:58 GMT",
"version": "v2"
}
] |
2008-02-03
|
[
[
"Hagiwara",
"K.",
""
],
[
"Matsumoto",
"S.",
""
],
[
"Kim",
"C. S.",
""
]
] |
A new framework to study electroweak physics at one-loop level in general ${\rm SU(2)_L \times U(1)_Y}$ theories is introduced. It separates the 1-loop corrections into two pieces: process specific ones from vertex and box contributions and the universal ones due to contributions to the gauge boson propagators. The latter are parametrized in terms of four effective form factors, $\bar{e}^2(q^2)$, $\bar{s}^2(q^2)$, $\bar{g}_Z^2(q^2)$, and $\bar{g}_W^2(q^2)$, correspondingly to $\gamma\gamma$, $\gamma Z$, $ZZ$, and $WW$ propagators. By assuming only the standard model contributions to the process specific corrections, the magnitudes of the four form factors are determined at $q^2=0$ and at $q^2=m_Z^2$ from all available precision experiments. These values are then compared systematically with the predictions of the ${\rm SU(2)_L \times U(1)_Y}$ theories. No deviation from the standard model has been identified. Plausible range of the top quark mass is then obtained for a given Higgs boson mass and $\alpha_s$ .
|
1101.4660
|
Wujun Huo Dr
|
H. Chen and W. Huo
|
New physical effects on the decay $B_{s(d)} \to \gamma\gamma$ in the
sequential fourth Generation model
|
11 pages, 6 figures
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study the contributions to the branching ratios of $B_{s(d)}\to \gamma
\gamma$ decay in the sequential fourth generation model (SM4). We find that the
theoretical values of the branching ratios, ${\rm
BR}(B_{s(d)}\to\gamma\gamma)$, including the contributions of $m_{t'}$ and the
new $4 \times 4$ CKM (CKM4) matrix factors, $|V^{*}_{t's}V_{t'b}|$ and
$|V^{*}_{t'd}V_{t'b}|$, are much different from the minimal standard model (SM)
predictions. The new physics effects, especially contributed from the CKM4
matrix factors, can provide more than one order enhancement to the SM
prediction. It is shown that the decay $B_{s(d)}\to \gamma \gamma$ can test the
new physics signals from SM4.
|
[
{
"created": "Mon, 24 Jan 2011 21:08:27 GMT",
"version": "v1"
}
] |
2011-01-26
|
[
[
"Chen",
"H.",
""
],
[
"Huo",
"W.",
""
]
] |
We study the contributions to the branching ratios of $B_{s(d)}\to \gamma \gamma$ decay in the sequential fourth generation model (SM4). We find that the theoretical values of the branching ratios, ${\rm BR}(B_{s(d)}\to\gamma\gamma)$, including the contributions of $m_{t'}$ and the new $4 \times 4$ CKM (CKM4) matrix factors, $|V^{*}_{t's}V_{t'b}|$ and $|V^{*}_{t'd}V_{t'b}|$, are much different from the minimal standard model (SM) predictions. The new physics effects, especially contributed from the CKM4 matrix factors, can provide more than one order enhancement to the SM prediction. It is shown that the decay $B_{s(d)}\to \gamma \gamma$ can test the new physics signals from SM4.
|
2001.06522
|
Xiao-Ping Wang
|
Jia Liu, Navin McGinnis, Carlos E.M. Wagner and Xiao-Ping Wang
|
A Light Scalar Explanation of $(g-2)_{\mu}$ and the KOTO Anomaly
|
31 pages, 5 figures, 1 table; v2: version matched to JHEP
|
JHEP04(2020)197
|
10.1007/JHEP04(2020)197
|
EFI-20-2
|
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The KOTO experiment has recently performed a search for neutral Kaons
decaying into neutral pions and a pair of neutrinos. Three events were observed
in the KOTO signal region, with an expected background of about 0.05. Since no
clear signal of systematic errors have been found, the excess of events in the
decay $K_{L}\rightarrow\pi^0\nu\bar{\nu}$ is quite intriguing. One possibility
to explain this anomaly would be the presence of a scalar $\phi$ with mass of
the order of the pion mass and inducing decays $K_L \to \pi^0 \phi$ which mimic
the observed signal.A scalar with mass of the order of the pion mass and a
coupling to muons of the order of the Standard Model Higgs coupling could also
explain the muon anomalous magnetic moment anomaly $(g-2)_{\mu}$. We built on
these facts to show that a light singlet scalar with couplings to the leptons
and quarks as the ones induced by mixing with Higgs states in two Higgs doublet
models may lead to an explanation of both anomalies. More specifically, we show
that this is the case in the so-called type-X models in which leptons and
quarks couple to two different Higgs doublets, and for scalar masses that are
in the range between 40 and 70 MeV. Due to the relatively large coupling to
leptons required to fit $(g-2)_{\mu}$, the scalar lifetime accidentally falls
into the sub-nanosecond range which is essential to evade the severe proton
beam dump experiments and astrophysical constraints, though it becomes
sensitive to constraints from electron beam dump experiments. The additional
phenomenological properties of this model are discussed.
|
[
{
"created": "Fri, 17 Jan 2020 20:28:59 GMT",
"version": "v1"
},
{
"created": "Sat, 11 Apr 2020 16:27:13 GMT",
"version": "v2"
}
] |
2020-04-30
|
[
[
"Liu",
"Jia",
""
],
[
"McGinnis",
"Navin",
""
],
[
"Wagner",
"Carlos E. M.",
""
],
[
"Wang",
"Xiao-Ping",
""
]
] |
The KOTO experiment has recently performed a search for neutral Kaons decaying into neutral pions and a pair of neutrinos. Three events were observed in the KOTO signal region, with an expected background of about 0.05. Since no clear signal of systematic errors have been found, the excess of events in the decay $K_{L}\rightarrow\pi^0\nu\bar{\nu}$ is quite intriguing. One possibility to explain this anomaly would be the presence of a scalar $\phi$ with mass of the order of the pion mass and inducing decays $K_L \to \pi^0 \phi$ which mimic the observed signal.A scalar with mass of the order of the pion mass and a coupling to muons of the order of the Standard Model Higgs coupling could also explain the muon anomalous magnetic moment anomaly $(g-2)_{\mu}$. We built on these facts to show that a light singlet scalar with couplings to the leptons and quarks as the ones induced by mixing with Higgs states in two Higgs doublet models may lead to an explanation of both anomalies. More specifically, we show that this is the case in the so-called type-X models in which leptons and quarks couple to two different Higgs doublets, and for scalar masses that are in the range between 40 and 70 MeV. Due to the relatively large coupling to leptons required to fit $(g-2)_{\mu}$, the scalar lifetime accidentally falls into the sub-nanosecond range which is essential to evade the severe proton beam dump experiments and astrophysical constraints, though it becomes sensitive to constraints from electron beam dump experiments. The additional phenomenological properties of this model are discussed.
|
hep-ph/9503451
|
Giovanni Amelino-Camelia
|
G. Amelino-Camelia (MIT)
|
Effective Potential Improvements, $\epsilon$-expansions, and the
Electroweak Phase Transition
|
4 pages, LaTex (requires espcrc2.sty which is appended). Contribution
to the Proceedings of Trends in Astroparticle Physics
|
Nucl.Phys.Proc.Suppl. 43 (1995) 278-281
|
10.1016/0920-5632(95)00490-Z
|
MIT-CTP-2419/INFN-NA-94-36
|
hep-ph
| null |
Two recently proposed approaches to the study of the electroweak phase
transition are discussed.
|
[
{
"created": "Mon, 27 Mar 1995 22:17:09 GMT",
"version": "v1"
}
] |
2009-10-28
|
[
[
"Amelino-Camelia",
"G.",
"",
"MIT"
]
] |
Two recently proposed approaches to the study of the electroweak phase transition are discussed.
|
2307.13967
|
Shao-Ping Li
|
Shao-Ping Li and Xun-Jie Xu
|
$N_{{\rm eff}}$ constraints on light mediators coupled to neutrinos: the
dilution-resistant effect
|
25 pages, 6 figures and 2 tables, version accepted by JHEP
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We investigate the impact of new light particles, carrying significant energy
in the early universe after neutrino decoupling, on the cosmological effective
relativistic neutrino species, $N_{{\rm eff}}$. If the light particles are
produced from decoupled neutrinos, $N_{{\rm eff}}$ is predominantly modified
through the dilution-resistant effect. This effect arises because the energy
stored in the mass of new particles is less diluted than the photon and
neutrino energy as the universe expands. Our study comprehensively explores
this effect, deriving $N_{{\rm eff}}$ constraints on the couplings of light
mediators with neutrinos, encompassing both scalar and vector mediators. We
find that the dilution-resistant effect can increase $N_{{\rm eff}}$ by 0.118
and 0.242 for scalar and vector mediators, respectively. These values can be
readily reached by forthcoming CMB experiments. Upon reaching these levels,
future $N_{{\rm eff}}$ constraints on the couplings will be improved by many
orders of magnitude.
|
[
{
"created": "Wed, 26 Jul 2023 05:58:10 GMT",
"version": "v1"
},
{
"created": "Tue, 3 Oct 2023 07:26:47 GMT",
"version": "v2"
}
] |
2023-10-04
|
[
[
"Li",
"Shao-Ping",
""
],
[
"Xu",
"Xun-Jie",
""
]
] |
We investigate the impact of new light particles, carrying significant energy in the early universe after neutrino decoupling, on the cosmological effective relativistic neutrino species, $N_{{\rm eff}}$. If the light particles are produced from decoupled neutrinos, $N_{{\rm eff}}$ is predominantly modified through the dilution-resistant effect. This effect arises because the energy stored in the mass of new particles is less diluted than the photon and neutrino energy as the universe expands. Our study comprehensively explores this effect, deriving $N_{{\rm eff}}$ constraints on the couplings of light mediators with neutrinos, encompassing both scalar and vector mediators. We find that the dilution-resistant effect can increase $N_{{\rm eff}}$ by 0.118 and 0.242 for scalar and vector mediators, respectively. These values can be readily reached by forthcoming CMB experiments. Upon reaching these levels, future $N_{{\rm eff}}$ constraints on the couplings will be improved by many orders of magnitude.
|
2402.17386
|
Emanuel Pfeffer
|
Emanuel Pfeffer and Michael Wa{\ss}mer and Yee-Ying Cung and Roger
Wolf and Ulrich Husemann
|
A case study of sending graph neural networks back to the test bench for
applications in high-energy particle physics
| null |
Comput Softw Big Sci 8, 13 (2024)
|
10.1007/s41781-024-00122-3
| null |
hep-ph cs.AI hep-ex
|
http://creativecommons.org/licenses/by/4.0/
|
In high-energy particle collisions, the primary collision products usually
decay further resulting in tree-like, hierarchical structures with a priori
unknown multiplicity. At the stable-particle level all decay products of a
collision form permutation invariant sets of final state objects. The analogy
to mathematical graphs gives rise to the idea that graph neural networks
(GNNs), which naturally resemble these properties, should be best-suited to
address many tasks related to high-energy particle physics. In this paper we
describe a benchmark test of a typical GNN against neural networks of the
well-established deep fully-connected feed-forward architecture. We aim at
performing this comparison maximally unbiased in terms of nodes, hidden layers,
or trainable parameters of the neural networks under study. As physics case we
use the classification of the final state X produced in association with top
quark-antiquark pairs in proton-proton collisions at the Large Hadron Collider
at CERN, where X stands for a bottom quark-antiquark pair produced either
non-resonantly or through the decay of an intermediately produced Z or Higgs
boson.
|
[
{
"created": "Tue, 27 Feb 2024 10:26:25 GMT",
"version": "v1"
}
] |
2024-07-15
|
[
[
"Pfeffer",
"Emanuel",
""
],
[
"Waßmer",
"Michael",
""
],
[
"Cung",
"Yee-Ying",
""
],
[
"Wolf",
"Roger",
""
],
[
"Husemann",
"Ulrich",
""
]
] |
In high-energy particle collisions, the primary collision products usually decay further resulting in tree-like, hierarchical structures with a priori unknown multiplicity. At the stable-particle level all decay products of a collision form permutation invariant sets of final state objects. The analogy to mathematical graphs gives rise to the idea that graph neural networks (GNNs), which naturally resemble these properties, should be best-suited to address many tasks related to high-energy particle physics. In this paper we describe a benchmark test of a typical GNN against neural networks of the well-established deep fully-connected feed-forward architecture. We aim at performing this comparison maximally unbiased in terms of nodes, hidden layers, or trainable parameters of the neural networks under study. As physics case we use the classification of the final state X produced in association with top quark-antiquark pairs in proton-proton collisions at the Large Hadron Collider at CERN, where X stands for a bottom quark-antiquark pair produced either non-resonantly or through the decay of an intermediately produced Z or Higgs boson.
|
0809.4473
|
Soo-hyeon Nam
|
Soo-hyeon Nam
|
Fermions and gauge bosons in $SU(4)_L \times U(1)_X$ models with little
Higgs
|
3 pages, to appear in the proceedings of 16th International
Conference on Supersymmetry and the Unification of Fundamental Interactions
(SUSY08), Seoul, Korea, June 16-21 2008; typos corrected
|
AIP Conf.Proc.1078:602-604,2009
|
10.1063/1.3052041
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We discuss the aspects of the little Higgs model with the $SU(4)_L \times
U(1)_X$ electroweak gauge group as an alternative solution to the naturalness
and fine-tuning issues. We introduce anomaly-free fermion spectra, and present
their interactions with the physical gauge bosons. We also discuss some
phenomenological implications of these fermions and the extra gauge bosons
based on recent experimental results.
|
[
{
"created": "Thu, 25 Sep 2008 18:57:01 GMT",
"version": "v1"
},
{
"created": "Wed, 15 Oct 2008 04:59:15 GMT",
"version": "v2"
}
] |
2009-02-02
|
[
[
"Nam",
"Soo-hyeon",
""
]
] |
We discuss the aspects of the little Higgs model with the $SU(4)_L \times U(1)_X$ electroweak gauge group as an alternative solution to the naturalness and fine-tuning issues. We introduce anomaly-free fermion spectra, and present their interactions with the physical gauge bosons. We also discuss some phenomenological implications of these fermions and the extra gauge bosons based on recent experimental results.
|
hep-ph/9712549
|
Boris Kerbikov
|
A.G.Zubkov, O.V.Dubasov, B.O.Kerbikov
|
Instanton-anti-instanton molecule with non-zero-modes of quarks included
|
15 pages, LaTeX2e
|
Int.J.Mod.Phys. A14 (1999) 241-252
|
10.1142/S0217751X99000129
|
ITEP-PH-16/97
|
hep-ph
| null |
A straightforward algebraic derivation is carried out of light quark
propagator and effective action in the instanton-anti-instanton molecule. Exact
expressions are obtained which contain contributions of all quark modes.
Possible implications of the results include chiral phase transition and
correlation functions of mesons and baryons.
|
[
{
"created": "Wed, 31 Dec 1997 09:15:03 GMT",
"version": "v1"
}
] |
2009-10-30
|
[
[
"Zubkov",
"A. G.",
""
],
[
"Dubasov",
"O. V.",
""
],
[
"Kerbikov",
"B. O.",
""
]
] |
A straightforward algebraic derivation is carried out of light quark propagator and effective action in the instanton-anti-instanton molecule. Exact expressions are obtained which contain contributions of all quark modes. Possible implications of the results include chiral phase transition and correlation functions of mesons and baryons.
|
hep-ph/9606381
|
Jay Watson
|
N.J. Watson (IPN, Orsay)
|
The Gauge-Independent QCD Effective Charge
|
48 pages, Latex, uses axodraw.sty (included). Revised to include
throughout the case of non-covariant gauges too
|
Nucl.Phys.B494:388-432,1997
|
10.1016/S0550-3213(97)00179-X
|
CPT-96/P.3347
|
hep-ph
| null |
It is shown how the QED concept of a gauge-, scale- and scheme-independent
one-loop effective charge can be extended directly at the diagrammatic level to
QCD, thus justifying explicitly the ``naive non-abelianization'' prescription
used in renormalon calculus. It is first argued that, for on-shell external
fields and at the strictly one-loop level, the required gluon self-energy-like
function is precisely that obtained from S-matrix elements via the pinch
technique. The generalization of the pinch technique to explicitly off-shell
processes is then introduced. It is shown how, as a result of a fundamental
cancellation among conventional perturbation theory diagrams, encoded in the
QCD Ward identities, the pinch technique one-loop gluon self-energy
i\hat{\Pi}_{\mu\nu}^{ab}(q) remains gauge-independent and universal regardless
of the fact that the ``external'' fields in the given process are off-shell.
This demonstration involves a simple technique enabling the isolation, in an
arbitrary gauge, of i\hat{\Pi}_{\mu\nu}^{ab}(q) from subclasses of up to
several hundred diagrams at once. Furthermore, it is shown how this one-loop
cancellation mechanism iterates for the subclasses of n-loop diagrams
containing implicitly the Dyson chains of n one-loop self-energies
i\hat{\Pi}_{\mu\nu}^{ab}(q). The gauge cancellation required for the Dyson
summation of i\hat{\Pi}_{\mu\nu}^{ab}(q) is thus demonstrated explicitly in a
general class of ghost-free gauges for all orders n.
|
[
{
"created": "Wed, 19 Jun 1996 15:25:07 GMT",
"version": "v1"
},
{
"created": "Tue, 1 Apr 1997 17:01:11 GMT",
"version": "v2"
}
] |
2008-11-26
|
[
[
"Watson",
"N. J.",
"",
"IPN, Orsay"
]
] |
It is shown how the QED concept of a gauge-, scale- and scheme-independent one-loop effective charge can be extended directly at the diagrammatic level to QCD, thus justifying explicitly the ``naive non-abelianization'' prescription used in renormalon calculus. It is first argued that, for on-shell external fields and at the strictly one-loop level, the required gluon self-energy-like function is precisely that obtained from S-matrix elements via the pinch technique. The generalization of the pinch technique to explicitly off-shell processes is then introduced. It is shown how, as a result of a fundamental cancellation among conventional perturbation theory diagrams, encoded in the QCD Ward identities, the pinch technique one-loop gluon self-energy i\hat{\Pi}_{\mu\nu}^{ab}(q) remains gauge-independent and universal regardless of the fact that the ``external'' fields in the given process are off-shell. This demonstration involves a simple technique enabling the isolation, in an arbitrary gauge, of i\hat{\Pi}_{\mu\nu}^{ab}(q) from subclasses of up to several hundred diagrams at once. Furthermore, it is shown how this one-loop cancellation mechanism iterates for the subclasses of n-loop diagrams containing implicitly the Dyson chains of n one-loop self-energies i\hat{\Pi}_{\mu\nu}^{ab}(q). The gauge cancellation required for the Dyson summation of i\hat{\Pi}_{\mu\nu}^{ab}(q) is thus demonstrated explicitly in a general class of ghost-free gauges for all orders n.
|
1109.5119
|
Sabine Kraml
|
S. Sekmen, S. Kraml, J. Lykken, F. Moortgat, S. Padhi, L. Pape, M.
Pierini, H. B. Prosper, M. Spiropulu
|
Interpreting LHC SUSY searches in the phenomenological MSSM
|
15 pages, 7 figures; minor revision, some references and a comment on
prior dependence added; version accepted by JHEP
| null |
10.1007/JHEP02(2012)075
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We interpret within the phenomenological MSSM (pMSSM) the results of SUSY
searches published by the CMS collaboration based on the first ~1 fb^-1 of data
taken during the 2011 LHC run at 7 TeV. The pMSSM is a 19-dimensional
parametrization of the MSSM that captures most of its phenomenological
features. It encompasses, and goes beyond, a broad range of more constrained
SUSY models. Performing a global Bayesian analysis, we obtain posterior
probability densities of parameters, masses and derived observables. In
contrast to constraints derived for particular SUSY breaking schemes, such as
the CMSSM, our results provide more generic conclusions on how the current data
constrain the MSSM.
|
[
{
"created": "Fri, 23 Sep 2011 16:08:42 GMT",
"version": "v1"
},
{
"created": "Mon, 23 Jan 2012 18:22:13 GMT",
"version": "v2"
}
] |
2015-05-30
|
[
[
"Sekmen",
"S.",
""
],
[
"Kraml",
"S.",
""
],
[
"Lykken",
"J.",
""
],
[
"Moortgat",
"F.",
""
],
[
"Padhi",
"S.",
""
],
[
"Pape",
"L.",
""
],
[
"Pierini",
"M.",
""
],
[
"Prosper",
"H. B.",
""
],
[
"Spiropulu",
"M.",
""
]
] |
We interpret within the phenomenological MSSM (pMSSM) the results of SUSY searches published by the CMS collaboration based on the first ~1 fb^-1 of data taken during the 2011 LHC run at 7 TeV. The pMSSM is a 19-dimensional parametrization of the MSSM that captures most of its phenomenological features. It encompasses, and goes beyond, a broad range of more constrained SUSY models. Performing a global Bayesian analysis, we obtain posterior probability densities of parameters, masses and derived observables. In contrast to constraints derived for particular SUSY breaking schemes, such as the CMSSM, our results provide more generic conclusions on how the current data constrain the MSSM.
|
1105.4664
|
Sergey Kovalenko
|
Claudio Dib, Juan Carlos Helo, Sergey Kovalenko, Ivan Schmidt
|
On Sterile neutrino explanation of LSND and MiniBooNE anomalies
|
6 pages, 2 figures, experimental cut taken into account, some
conclusions changed
| null |
10.1103/PhysRevD.84.071301
| null |
hep-ph astro-ph.HE hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We examine the compatibility between existing experimental data and a
recently proposed explanation of the LSND and MiniBooNE anomalies, given in
terms of a sterile neutrino $N$ whose decay is dominated by a radiative mode.
We find that current experimental data on $\tau\rightarrow \mu\nu\nu\gamma$
decays are compatible with the sterile neutrino parameters required for the
explanation of the anomalies, but $K\rightarrow \mu\nu\gamma$ shows a marginal
tension with those parameters. We also propose experimental cuts on radiative
$K$ decays that could test the sterile neutrino hypothesis better. Finally, we
study the contribution of this sterile neutrino to $K\to\mu\nu e e$, and find
that measurements of this process would provide powerful tests for the sterile
neutrino explanation of the LSND and MiniBooNE anomalies, if the experimental
cut on the invariant mass of the $e^{+}e^{-}$ pair could be reduced from its
current value of 145 MeV to a value below 40 MeV.
|
[
{
"created": "Tue, 24 May 2011 01:09:12 GMT",
"version": "v1"
},
{
"created": "Wed, 8 Jun 2011 02:42:00 GMT",
"version": "v2"
}
] |
2013-05-29
|
[
[
"Dib",
"Claudio",
""
],
[
"Helo",
"Juan Carlos",
""
],
[
"Kovalenko",
"Sergey",
""
],
[
"Schmidt",
"Ivan",
""
]
] |
We examine the compatibility between existing experimental data and a recently proposed explanation of the LSND and MiniBooNE anomalies, given in terms of a sterile neutrino $N$ whose decay is dominated by a radiative mode. We find that current experimental data on $\tau\rightarrow \mu\nu\nu\gamma$ decays are compatible with the sterile neutrino parameters required for the explanation of the anomalies, but $K\rightarrow \mu\nu\gamma$ shows a marginal tension with those parameters. We also propose experimental cuts on radiative $K$ decays that could test the sterile neutrino hypothesis better. Finally, we study the contribution of this sterile neutrino to $K\to\mu\nu e e$, and find that measurements of this process would provide powerful tests for the sterile neutrino explanation of the LSND and MiniBooNE anomalies, if the experimental cut on the invariant mass of the $e^{+}e^{-}$ pair could be reduced from its current value of 145 MeV to a value below 40 MeV.
|
1208.3404
|
Tobias Kasprzik
|
Anastasiya Bierweiler, Tobias Kasprzik, Johann H. Kuhn
|
Electroweak accuracy in V-pair production at the LHC
|
6 pages, 4 figures; to appear in the proceedings of the 36th ICHEP
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Vector-boson pair production is of great phenomenological importance at the
LHC. These processes will help to validate the Standard Model at highest
energies, and they may also open the door for the discovery of new physics
potentially showing up in subtle modifications of the non-abelian structure of
weak interactions. In this letter, we present the first full
$\mathcal{O}(\alpha^3)$ analysis of on-shell W$^\pm$Z and Z-pair production at
the LHC with all mass effects consistently included. The resulting electroweak
corrections are negative, strongly increase with increasing transverse momenta,
and lead to significant modifications of rapidity and angular distributions. In
view of the high energies accessible at the LHC, combined with considerable
event rates, our results have to be included in a proper analysis of
experimental data.
|
[
{
"created": "Thu, 16 Aug 2012 16:01:36 GMT",
"version": "v1"
}
] |
2012-08-17
|
[
[
"Bierweiler",
"Anastasiya",
""
],
[
"Kasprzik",
"Tobias",
""
],
[
"Kuhn",
"Johann H.",
""
]
] |
Vector-boson pair production is of great phenomenological importance at the LHC. These processes will help to validate the Standard Model at highest energies, and they may also open the door for the discovery of new physics potentially showing up in subtle modifications of the non-abelian structure of weak interactions. In this letter, we present the first full $\mathcal{O}(\alpha^3)$ analysis of on-shell W$^\pm$Z and Z-pair production at the LHC with all mass effects consistently included. The resulting electroweak corrections are negative, strongly increase with increasing transverse momenta, and lead to significant modifications of rapidity and angular distributions. In view of the high energies accessible at the LHC, combined with considerable event rates, our results have to be included in a proper analysis of experimental data.
|
hep-ph/0507317
|
Nikolaos Kidonakis
|
Richard J. Gonsalves, Nikolaos Kidonakis, and Agustin Sabio Vera
|
W production at large transverse momentum at the Large Hadron Collider
|
12 pages, 7 figures
|
Phys.Rev.Lett.95:222001,2005
|
10.1103/PhysRevLett.95.222001
| null |
hep-ph
| null |
We study the production of W bosons at large transverse momentum in pp
collisions at the Large Hadron Collider (LHC). We calculate the complete
next-to-leading order (NLO) corrections to the differential cross section. We
find that the NLO corrections provide a large increase to the cross section
but, surprisingly, do not reduce the scale dependence relative to leading order
(LO). We also calculate next-to-next-to-leading-order (NNLO) soft-gluon
corrections and find that, although they are small, they significantly reduce
the scale dependence thus providing a more stable theoretical prediction.
|
[
{
"created": "Wed, 27 Jul 2005 20:11:29 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Gonsalves",
"Richard J.",
""
],
[
"Kidonakis",
"Nikolaos",
""
],
[
"Vera",
"Agustin Sabio",
""
]
] |
We study the production of W bosons at large transverse momentum in pp collisions at the Large Hadron Collider (LHC). We calculate the complete next-to-leading order (NLO) corrections to the differential cross section. We find that the NLO corrections provide a large increase to the cross section but, surprisingly, do not reduce the scale dependence relative to leading order (LO). We also calculate next-to-next-to-leading-order (NNLO) soft-gluon corrections and find that, although they are small, they significantly reduce the scale dependence thus providing a more stable theoretical prediction.
|
1409.7605
|
Michael Trott
|
Michael Trott
|
On the consistent use of Constructed Observables
|
24pp, 1 fig v2: Appendix added on notation, and operators, to make
paper more self contained. JHEP version
| null |
10.1007/JHEP02(2015)046
|
CERN-PH-TH/2014-187
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We define "constructed observables" as relating experimental measurements to
terms in a Lagrangian while simultaneously making assumptions about possible
deviations from the Standard Model (SM), in other Lagrangian terms. Ensuring
that the SM effective field theory (EFT) is constrained correctly when using
constructed observables requires that their defining conditions are imposed on
the EFT in a manner that is consistent with the equations of motion. Failing to
do so can result in a "functionally redundant" operator basis and the wrong
expectation as to how experimental quantities are related in the EFT. We
illustrate the issues involved considering the $\rm S$ parameter and the off
shell triple gauge coupling (TGC) verticies. We show that the relationships
between $h \rightarrow V \bar{f} \, f$ decay and the off shell TGC verticies
are subject to these subtleties, and how the connections between these
observables vanish in the limit of strong bounds due to LEP. The challenge of
using constructed observables to consistently constrain the Standard Model EFT
is only expected to grow with future LHC data, as more complex processes are
studied.
|
[
{
"created": "Fri, 26 Sep 2014 15:42:13 GMT",
"version": "v1"
},
{
"created": "Sat, 17 Jan 2015 18:03:37 GMT",
"version": "v2"
}
] |
2015-06-23
|
[
[
"Trott",
"Michael",
""
]
] |
We define "constructed observables" as relating experimental measurements to terms in a Lagrangian while simultaneously making assumptions about possible deviations from the Standard Model (SM), in other Lagrangian terms. Ensuring that the SM effective field theory (EFT) is constrained correctly when using constructed observables requires that their defining conditions are imposed on the EFT in a manner that is consistent with the equations of motion. Failing to do so can result in a "functionally redundant" operator basis and the wrong expectation as to how experimental quantities are related in the EFT. We illustrate the issues involved considering the $\rm S$ parameter and the off shell triple gauge coupling (TGC) verticies. We show that the relationships between $h \rightarrow V \bar{f} \, f$ decay and the off shell TGC verticies are subject to these subtleties, and how the connections between these observables vanish in the limit of strong bounds due to LEP. The challenge of using constructed observables to consistently constrain the Standard Model EFT is only expected to grow with future LHC data, as more complex processes are studied.
|
2010.09362
|
Run-Hui Li
|
Run-Hui Li, Juan-Juan Hou, Bei He, Ya-Ru Wang
|
Weak Decays of Doubly Heavy Baryons: ${\cal B}_{cc}\to {\cal B} D^{(*)}$
|
21 pages, 4 figures, 8 tables; Published version
| null |
10.1088/1674-1137/abe0bc
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The discovery of $\Xi_{cc}^{++}$ has inspired new interest in studying doubly
heavy baryons. In this study, the weak decays of a doubly charmed baryon ${\cal
B}_{cc}$ to a light baryon ${\cal B}$ and a charm meson $D^{(*)}$ (either a
pseudoscalar or a vector one) are calculated. Following our previous work, we
calculate the short distance contributions under the factorization hypothesis,
whereas the long distance contributions are modeled as the final state
interactions which are calculated with the one particle exchange model. We find
that the ${\cal B}_{cc}\to {\cal B} D^{*}$ decays' branching ratios are
obviously larger, as they receive contributions of more polarization states.
Among the decays that we investigate, the following have the largest branching
fractions: ${\cal BR}(\Xi_{cc}^{++}\rightarrow\Sigma^{+}D^{*+}) \in [0.46\%,
3.33\%]$ estimated with $\tau_{\Xi_{cc}^{++}}=256$ fs; ${\cal
BR}(\Xi_{cc}^{+}\rightarrow\Lambda D^{*+}) \in [0.38\%, 2.63\%]$ and ${\cal
BR}(\Xi_{cc}^{+}\rightarrow\Sigma^{0} D^{*+}) \in [0.45\%, 3.16\%]$ with
$\tau_{\Xi_{cc}^+}=45$ fs; and ${\cal BR}(\Omega_{cc}^{+}\rightarrow\Xi^{0}
D^{*+}) \in [0.27\%, 1.03\%]$, ${\cal BR}(\Omega_{cc}^{+}\rightarrow\Xi^{0}
D^{+}) \in [0.07\%, 0.44\%]$ and ${\cal
BR}(\Omega_{cc}^{+}\rightarrow\Sigma^{0} D^{*+}) \in [0.06\%, 0.45\%]$ with
$\tau_{\Omega_{cc}^+}=75$ fs. By comparing the decay widths of pure color
commensurate channels with those of pure bow-tie ones, we find that the bow-tie
mechanism plays an important role in charm decays.
|
[
{
"created": "Mon, 19 Oct 2020 10:00:57 GMT",
"version": "v1"
},
{
"created": "Mon, 22 Feb 2021 02:28:25 GMT",
"version": "v2"
}
] |
2021-02-23
|
[
[
"Li",
"Run-Hui",
""
],
[
"Hou",
"Juan-Juan",
""
],
[
"He",
"Bei",
""
],
[
"Wang",
"Ya-Ru",
""
]
] |
The discovery of $\Xi_{cc}^{++}$ has inspired new interest in studying doubly heavy baryons. In this study, the weak decays of a doubly charmed baryon ${\cal B}_{cc}$ to a light baryon ${\cal B}$ and a charm meson $D^{(*)}$ (either a pseudoscalar or a vector one) are calculated. Following our previous work, we calculate the short distance contributions under the factorization hypothesis, whereas the long distance contributions are modeled as the final state interactions which are calculated with the one particle exchange model. We find that the ${\cal B}_{cc}\to {\cal B} D^{*}$ decays' branching ratios are obviously larger, as they receive contributions of more polarization states. Among the decays that we investigate, the following have the largest branching fractions: ${\cal BR}(\Xi_{cc}^{++}\rightarrow\Sigma^{+}D^{*+}) \in [0.46\%, 3.33\%]$ estimated with $\tau_{\Xi_{cc}^{++}}=256$ fs; ${\cal BR}(\Xi_{cc}^{+}\rightarrow\Lambda D^{*+}) \in [0.38\%, 2.63\%]$ and ${\cal BR}(\Xi_{cc}^{+}\rightarrow\Sigma^{0} D^{*+}) \in [0.45\%, 3.16\%]$ with $\tau_{\Xi_{cc}^+}=45$ fs; and ${\cal BR}(\Omega_{cc}^{+}\rightarrow\Xi^{0} D^{*+}) \in [0.27\%, 1.03\%]$, ${\cal BR}(\Omega_{cc}^{+}\rightarrow\Xi^{0} D^{+}) \in [0.07\%, 0.44\%]$ and ${\cal BR}(\Omega_{cc}^{+}\rightarrow\Sigma^{0} D^{*+}) \in [0.06\%, 0.45\%]$ with $\tau_{\Omega_{cc}^+}=75$ fs. By comparing the decay widths of pure color commensurate channels with those of pure bow-tie ones, we find that the bow-tie mechanism plays an important role in charm decays.
|
2208.00427
|
Khursid Alam
|
Khursid Alam, Koushik Dutta
|
Effects of Reheating on Moduli Stabilization
|
19 pages, 9 figures
| null | null | null |
hep-ph astro-ph.CO gr-qc hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Moduli potential loses its minima due to external energy sources of inflaton
energy density or radiation produced at the end of inflation. But, the
non-existence of minima does not necessarily mean destabilization of moduli. In
fact, the destabilization of moduli is always dependent on the initial field
values of the fields. In this work, we study carefully how the effects of
reheating ease the problem of moduli destabilization. The associated time scale
to produce the thermal bath allows a larger initial field range to stabilize
the field. Contrary to the usual notion, the allowed initial field range is
larger for higher temperatures when the effective potential is of a run-away
nature. This eases the moduli destabilization problem for heavy mass moduli.
For low mass moduli ($\lesssim$ 30 TeV), the allowed field range still causes
the cosmological moduli problem by violating the BBN constraints unless its
initial abundance is suppressed.
|
[
{
"created": "Sun, 31 Jul 2022 13:23:47 GMT",
"version": "v1"
}
] |
2022-08-05
|
[
[
"Alam",
"Khursid",
""
],
[
"Dutta",
"Koushik",
""
]
] |
Moduli potential loses its minima due to external energy sources of inflaton energy density or radiation produced at the end of inflation. But, the non-existence of minima does not necessarily mean destabilization of moduli. In fact, the destabilization of moduli is always dependent on the initial field values of the fields. In this work, we study carefully how the effects of reheating ease the problem of moduli destabilization. The associated time scale to produce the thermal bath allows a larger initial field range to stabilize the field. Contrary to the usual notion, the allowed initial field range is larger for higher temperatures when the effective potential is of a run-away nature. This eases the moduli destabilization problem for heavy mass moduli. For low mass moduli ($\lesssim$ 30 TeV), the allowed field range still causes the cosmological moduli problem by violating the BBN constraints unless its initial abundance is suppressed.
|
hep-ph/0609038
|
Stefan Antusch
|
S. Antusch, S.F. King, A. Riotto
|
Flavour-Dependent Leptogenesis with Sequential Dominance
|
32 pages, 3 figures; minor corrections; final version published in
JCAP
|
JCAP0611:011,2006
|
10.1088/1475-7516/2006/11/011
|
CERN-PH-TH/2006-174, FTUAM 06-14, IFT-UAM/CSIC 06-43, SHEP-06-25
|
hep-ph
| null |
We study thermal leptogenesis in classes of neutrino mass models based on the
seesaw mechanism with three right-handed neutrinos and sequential right-handed
neutrino dominance. The flavour-dependent Boltzmann equations are solved
appropriate to both the Standard Model and the Minimal Supersymmetric Standard
Model. Within these classes of models we investigate constraints and
expectations on the individual decay asymmetries and washout parameters from
the present data on neutrino masses and mixings. In many cases of physical
interest flavour effects are shown to have important consequences for the
estimation of the produced baryon asymmetry in leptogenesis. We also establish
and analyze the link between the leptonic CP violating phase $\delta$,
observable in neutrino oscillations, and the CP violation required for
leptogenesis, where flavour-dependent effects have a significant effect. In
general our results show that flavour-dependent effects cannot be ignored when
dealing with three right-handed neutrino models.
|
[
{
"created": "Tue, 5 Sep 2006 10:55:17 GMT",
"version": "v1"
},
{
"created": "Tue, 26 Sep 2006 14:31:00 GMT",
"version": "v2"
},
{
"created": "Tue, 7 Nov 2006 12:22:59 GMT",
"version": "v3"
},
{
"created": "Thu, 14 Dec 2006 11:18:58 GMT",
"version": "v4"
}
] |
2009-11-11
|
[
[
"Antusch",
"S.",
""
],
[
"King",
"S. F.",
""
],
[
"Riotto",
"A.",
""
]
] |
We study thermal leptogenesis in classes of neutrino mass models based on the seesaw mechanism with three right-handed neutrinos and sequential right-handed neutrino dominance. The flavour-dependent Boltzmann equations are solved appropriate to both the Standard Model and the Minimal Supersymmetric Standard Model. Within these classes of models we investigate constraints and expectations on the individual decay asymmetries and washout parameters from the present data on neutrino masses and mixings. In many cases of physical interest flavour effects are shown to have important consequences for the estimation of the produced baryon asymmetry in leptogenesis. We also establish and analyze the link between the leptonic CP violating phase $\delta$, observable in neutrino oscillations, and the CP violation required for leptogenesis, where flavour-dependent effects have a significant effect. In general our results show that flavour-dependent effects cannot be ignored when dealing with three right-handed neutrino models.
|
hep-ph/9507235
|
Steve Mrenna
|
S. Mrenna (California Institute of Technology) and C.-P. Yuan
(Michigan State University)
|
High-p_T Higgs Boson Production at Hadron Colliders to Order(alpha_s
G_Fermi^3)
|
Latex file,16 pages, 2 figures, uses psfig.sty, postscript file
available at ftp://cithe502.cithep.caltech.edu/pub/mrenna/cp0.ps or at
http://www.cithep.caltech.edu/~mrenna
|
Phys.Rev.D53:3547-3554,1996
|
10.1103/PhysRevD.53.3547
|
MSUHEP--050627, CITHE--68--2006
|
hep-ph
| null |
We study high--$p_T$ Higgs boson production at hadron colliders to
order($\alpha_s$ $G_F^3$) in hadron collisions. In particular, we investigate
the process $g+q/\bar{q}\ra q/\bar{q}+H$, where $q=u,d,c,s,$ or $b$, for the
LHC (a $\sqrt{s}=$14~TeV, proton--proton collider). Our results are compared to
the order($\alpha_s^3$ $G_F$) calculation. The associated production of a
high--$p_T$ Higgs boson with a $b$--quark or anti--quark is comparable to the
order($\alpha_s^3$ $G_F$) calculation because of the large top quark mass and
the additional contribution of electroweak gauge and Goldstone bosons. The
associated production of light quarks, however, is not significant. We also
comment on new physics effects in the framework of the electroweak chiral
Lagrangian.
|
[
{
"created": "Wed, 5 Jul 1995 18:41:42 GMT",
"version": "v1"
}
] |
2008-12-18
|
[
[
"Mrenna",
"S.",
"",
"California Institute of Technology"
],
[
"Yuan",
"C. -P.",
"",
"Michigan State University"
]
] |
We study high--$p_T$ Higgs boson production at hadron colliders to order($\alpha_s$ $G_F^3$) in hadron collisions. In particular, we investigate the process $g+q/\bar{q}\ra q/\bar{q}+H$, where $q=u,d,c,s,$ or $b$, for the LHC (a $\sqrt{s}=$14~TeV, proton--proton collider). Our results are compared to the order($\alpha_s^3$ $G_F$) calculation. The associated production of a high--$p_T$ Higgs boson with a $b$--quark or anti--quark is comparable to the order($\alpha_s^3$ $G_F$) calculation because of the large top quark mass and the additional contribution of electroweak gauge and Goldstone bosons. The associated production of light quarks, however, is not significant. We also comment on new physics effects in the framework of the electroweak chiral Lagrangian.
|
1409.1517
|
Marcelo Loewe Dr
|
Alejandro Ayala, M. Loewe, C. Villavicencio, R. Zamora
|
On the magnetic catalysis and inverse catalysis of phase transitions in
the linear sigma model
|
Contribution to the QCD14 conference, Montpellier, France. To appear
in the proceedings
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider the evolution of critical temperature both for the formation of a
pion condensate as well as for the chiral transition, from the perspective of
the linear sigma model, in the background of a magnetic field. We developed the
discussion for the pion condensate in one loop approximation for the effective
potential getting magnetic catalysis for high values of B, i.e. a raising of
the critical temperature with the magnetic field. For the analysis of the
chiral restoration, we go beyond this approximation, by taking one loop
thermo-magnetic corrections to the couplings as well as plasma screening
effects for the boson's masses, expressed through the resumation of ring
diagrams. Here we found the opposite behavior, i.e. inverse magnetica
catalysis, i.e. a decreasing of the chiral critical temperature as function of
the intensity of the magnetic field, which seems to be in agreement with recent
results form the lattice community.
|
[
{
"created": "Thu, 4 Sep 2014 18:35:36 GMT",
"version": "v1"
}
] |
2014-09-05
|
[
[
"Ayala",
"Alejandro",
""
],
[
"Loewe",
"M.",
""
],
[
"Villavicencio",
"C.",
""
],
[
"Zamora",
"R.",
""
]
] |
We consider the evolution of critical temperature both for the formation of a pion condensate as well as for the chiral transition, from the perspective of the linear sigma model, in the background of a magnetic field. We developed the discussion for the pion condensate in one loop approximation for the effective potential getting magnetic catalysis for high values of B, i.e. a raising of the critical temperature with the magnetic field. For the analysis of the chiral restoration, we go beyond this approximation, by taking one loop thermo-magnetic corrections to the couplings as well as plasma screening effects for the boson's masses, expressed through the resumation of ring diagrams. Here we found the opposite behavior, i.e. inverse magnetica catalysis, i.e. a decreasing of the chiral critical temperature as function of the intensity of the magnetic field, which seems to be in agreement with recent results form the lattice community.
|
hep-ph/9512394
|
Johan Linde
|
Johan Linde and H{\aa}kan Snellman
|
Evidence for mass dependent effects in the spin structure of baryons
|
10 pages, REVTeX, 1 figure
| null | null | null |
hep-ph
| null |
We analyze the axial-vector form factors of the nucleon hyperon system in a
model with mass dependent quark spin polarizations. This mass dependence is
deduced from an earlier analysis\cite{jlhs,jlhs2} of magnetic moment data, and
implies that the spin contributions from the quarks to a baryon decrease with
the mass of the baryon. When applied to the axial-vector form factors, these
mass dependent spin polarizations bring the various sum-rules from the model in
better agreement with experimental data. Our analysis leads to a reduced value
for the total spin polarization of the proton.
|
[
{
"created": "Thu, 21 Dec 1995 15:57:36 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Linde",
"Johan",
""
],
[
"Snellman",
"Håkan",
""
]
] |
We analyze the axial-vector form factors of the nucleon hyperon system in a model with mass dependent quark spin polarizations. This mass dependence is deduced from an earlier analysis\cite{jlhs,jlhs2} of magnetic moment data, and implies that the spin contributions from the quarks to a baryon decrease with the mass of the baryon. When applied to the axial-vector form factors, these mass dependent spin polarizations bring the various sum-rules from the model in better agreement with experimental data. Our analysis leads to a reduced value for the total spin polarization of the proton.
|
2003.06545
|
Jordi Salinas
|
Alejandro Ayala, David de la Cruz, L. A. Hern\'andez, Jordi Salinas
|
Relaxation time for the alignment between the spin of a finite-mass
quark/antiquark and the thermal vorticity in relativistic heavy-ion
collisions
|
6 pages, 7 figures. Expanded discussion, conclusions unchanged. arXiv
admin note: text overlap with arXiv:1909.00274
|
Phys. Rev. D 102, 056019 (2020)
|
10.1103/PhysRevD.102.056019
| null |
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study the relaxation time required for the alignment between the spin of a
finite-mass quark/antiquark and the thermal vorticity, at finite temperature
and baryon chemical potential, in the context of relativistic heavy-ion
collisions. The relaxation time is computed as the inverse of the total
reaction rate that in turn is obtained from the imaginary part of the
quark/antiquark self-energy. We model the interaction between spin and thermal
vorticity within the medium by means of a vertex coupling quarks and thermal
gluons that, for a uniform temperature, is proportional to the global angular
velocity and inversely proportional to the temperature. We use realistic
estimates for the angular velocities for different collision energies and show
that the effect of the quark mass is to reduce the relaxation times as compared
to the massless quark case. Using these relaxation times we estimate the
intrinsic quark and antiquark polarizations produced by the thermal vorticity.
We conclude by pointing out that, in spite of the former being larger than the
latter, it is still possible to understand recent results from the STAR Beam
Energy Scan when accounting for the fact that only a portion of
quarks/antiquarks come from the denser and thus thermalized region in the
collision.
|
[
{
"created": "Sat, 14 Mar 2020 04:02:42 GMT",
"version": "v1"
},
{
"created": "Tue, 19 May 2020 04:35:46 GMT",
"version": "v2"
}
] |
2020-09-23
|
[
[
"Ayala",
"Alejandro",
""
],
[
"de la Cruz",
"David",
""
],
[
"Hernández",
"L. A.",
""
],
[
"Salinas",
"Jordi",
""
]
] |
We study the relaxation time required for the alignment between the spin of a finite-mass quark/antiquark and the thermal vorticity, at finite temperature and baryon chemical potential, in the context of relativistic heavy-ion collisions. The relaxation time is computed as the inverse of the total reaction rate that in turn is obtained from the imaginary part of the quark/antiquark self-energy. We model the interaction between spin and thermal vorticity within the medium by means of a vertex coupling quarks and thermal gluons that, for a uniform temperature, is proportional to the global angular velocity and inversely proportional to the temperature. We use realistic estimates for the angular velocities for different collision energies and show that the effect of the quark mass is to reduce the relaxation times as compared to the massless quark case. Using these relaxation times we estimate the intrinsic quark and antiquark polarizations produced by the thermal vorticity. We conclude by pointing out that, in spite of the former being larger than the latter, it is still possible to understand recent results from the STAR Beam Energy Scan when accounting for the fact that only a portion of quarks/antiquarks come from the denser and thus thermalized region in the collision.
|
1708.00268
|
Mathieu Pellen
|
Benedikt Biedermann, Ansgar Denner, Mathieu Pellen
|
Complete NLO corrections to ${\rm W}^+{\rm W}^+$ scattering and its
irreducible background at the LHC
|
25 pages,21 eps-figures. Matches the published version
|
JHEP 1710 (2017) 124
|
10.1007/JHEP10(2017)124
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The process ${\rm p}{\rm p}\to\mu^+\nu_\mu{\rm e}^+\nu_{\rm e}{\rm j}{\rm j}$
receives several contributions of different orders in the strong and
electroweak coupling constants. Using appropriate event selections, this
process is dominated by vector-boson scattering (VBS) and has recently been
measured at the LHC. It is thus of prime importance to estimate precisely each
contribution. In this article we compute for the first time the full NLO QCD
and electroweak corrections to VBS and its irreducible background processes
with realistic experimental cuts. We do not rely on approximations but use
complete amplitudes involving two different orders at tree level and three
different orders at one-loop level. Since we take into account all
interferences, at NLO level the corrections to the VBS process and to the
QCD-induced irreducible background process contribute at the same orders. Hence
the two processes cannot be unambiguously distinguished, and all contributions
to the $\mu^+\nu_\mu{\rm e}^+\nu_{\rm e}{\rm j}{\rm j}$ final state should be
preferably measured together.
|
[
{
"created": "Tue, 1 Aug 2017 12:06:17 GMT",
"version": "v1"
},
{
"created": "Tue, 7 Nov 2017 11:44:21 GMT",
"version": "v2"
}
] |
2017-11-08
|
[
[
"Biedermann",
"Benedikt",
""
],
[
"Denner",
"Ansgar",
""
],
[
"Pellen",
"Mathieu",
""
]
] |
The process ${\rm p}{\rm p}\to\mu^+\nu_\mu{\rm e}^+\nu_{\rm e}{\rm j}{\rm j}$ receives several contributions of different orders in the strong and electroweak coupling constants. Using appropriate event selections, this process is dominated by vector-boson scattering (VBS) and has recently been measured at the LHC. It is thus of prime importance to estimate precisely each contribution. In this article we compute for the first time the full NLO QCD and electroweak corrections to VBS and its irreducible background processes with realistic experimental cuts. We do not rely on approximations but use complete amplitudes involving two different orders at tree level and three different orders at one-loop level. Since we take into account all interferences, at NLO level the corrections to the VBS process and to the QCD-induced irreducible background process contribute at the same orders. Hence the two processes cannot be unambiguously distinguished, and all contributions to the $\mu^+\nu_\mu{\rm e}^+\nu_{\rm e}{\rm j}{\rm j}$ final state should be preferably measured together.
|
1804.05016
|
Igor Anikin
|
I.V. Anikin, L. Szymanowski
|
Gluon poles and photon distribution amplitudes in Drell-Yan-like
processes
|
6 pages, 3 figures; Appendix has been added
| null |
10.1140/epja/i2018-12568-4
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We calculate the hadron tensor related to the photon-induced Drell-Yan
process, with incoming nucleon being transversally polarised. We predict the
new single spin asymmetry which probes gluon poles and which is expressed in
terms of photon (both chiral-odd and chiral-even) distribution amplitudes and
chiral-odd nucleon function stemming from the nucleon transverse polarization.
|
[
{
"created": "Fri, 13 Apr 2018 16:36:42 GMT",
"version": "v1"
},
{
"created": "Wed, 30 May 2018 15:49:22 GMT",
"version": "v2"
}
] |
2018-08-29
|
[
[
"Anikin",
"I. V.",
""
],
[
"Szymanowski",
"L.",
""
]
] |
We calculate the hadron tensor related to the photon-induced Drell-Yan process, with incoming nucleon being transversally polarised. We predict the new single spin asymmetry which probes gluon poles and which is expressed in terms of photon (both chiral-odd and chiral-even) distribution amplitudes and chiral-odd nucleon function stemming from the nucleon transverse polarization.
|
2108.01279
|
Xin Wang
|
Xin Wang
|
Muon $(g-2)$ and Flavor Puzzles in the $U(1)^{}_{X}$-gauged Leptoquark
Model
|
34 pages, 5 figures, more discussions added, published in JHEP
|
JHEP 08 (2022) 243
|
10.1007/JHEP08(2022)243
| null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
We present an economical model where an $S^{}_1$ leptoquark and an
anomaly-free $U(1)^{}_X$ gauge symmetry with $X =
B^{}_3-2L^{}_\mu/3-L^{}_\tau/3$ are introduced, to account for the muon
anomalous magnetic moment $a^{}_\mu \equiv (g^{}_\mu-2)$ and flavor puzzles
including $R^{}_{K^{(\ast)_{}}}$ and $R^{}_{D^{(\ast)_{}}}$ anomalies together
with quark and lepton flavor mixing. The $Z^\prime_{}$ gauge boson associated
with the $U(1)^{}_X$ symmetry is responsible for the $R^{}_{K^{(\ast)_{}}}$
anomaly. Meanwhile, the specific flavor mixing patterns of quarks and leptons
can be generated after the spontaneous breakdown of the $U(1)^{}_X$ gauge
symmetry via the Froggatt-Nielsen mechanism. The $S^{}_1$ leptoquark which is
also charged under the $U(1)^{}_X$ gauge symmetry can simultaneously explain
the latest muon $(g-2)$ result and the $R^{}_{D^{(\ast)_{}}}$ anomaly. In
addition, we also discuss several other experimental constraints on our model.
|
[
{
"created": "Tue, 3 Aug 2021 04:01:08 GMT",
"version": "v1"
},
{
"created": "Tue, 10 Aug 2021 08:00:19 GMT",
"version": "v2"
},
{
"created": "Thu, 25 Aug 2022 08:53:10 GMT",
"version": "v3"
}
] |
2022-08-26
|
[
[
"Wang",
"Xin",
""
]
] |
We present an economical model where an $S^{}_1$ leptoquark and an anomaly-free $U(1)^{}_X$ gauge symmetry with $X = B^{}_3-2L^{}_\mu/3-L^{}_\tau/3$ are introduced, to account for the muon anomalous magnetic moment $a^{}_\mu \equiv (g^{}_\mu-2)$ and flavor puzzles including $R^{}_{K^{(\ast)_{}}}$ and $R^{}_{D^{(\ast)_{}}}$ anomalies together with quark and lepton flavor mixing. The $Z^\prime_{}$ gauge boson associated with the $U(1)^{}_X$ symmetry is responsible for the $R^{}_{K^{(\ast)_{}}}$ anomaly. Meanwhile, the specific flavor mixing patterns of quarks and leptons can be generated after the spontaneous breakdown of the $U(1)^{}_X$ gauge symmetry via the Froggatt-Nielsen mechanism. The $S^{}_1$ leptoquark which is also charged under the $U(1)^{}_X$ gauge symmetry can simultaneously explain the latest muon $(g-2)$ result and the $R^{}_{D^{(\ast)_{}}}$ anomaly. In addition, we also discuss several other experimental constraints on our model.
|
0908.0532
|
Jamison Galloway
|
Jamison Galloway, Bob McElrath, John McRaven, John Terning
|
Gaugephobic Higgs Signals at the LHC
|
16 pages, 8 figures
|
JHEP 0911:031,2009
|
10.1088/1126-6708/2009/11/031
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The Gaugephobic Higgs model provides an interpolation between three different
models of electroweak symmetry breaking: Higgsless models, Randall-Sundrum
models, and the Standard Model. At parameter points between the extremes,
Standard Model Higgs signals are present at reduced rates, and Higgsless
Kaluza-Klein excitations are present with shifted masses and couplings, as well
as signals from exotic quarks necessary to protect the Zbb coupling. Using a
new implementation of the model in SHERPA, we show the LHC signals which
differentiate the generic Gaugephobic Higgs model from its limiting cases.
These are all signals involving a Higgs coupling to a Kaluza-Klein gauge boson
or quark. We identify the clean signal $p p \to W^(i) \to W H$ mediated by a
Kaluza-Klein W, which can be present at large rates and is enhanced for even
Kaluza-Klein numbers. Due to the very hard lepton coming from the W decay, this
signature has little background, and provides a better discovery channel for
the Higgs than any of the Standard Model modes, over its entire mass range. A
Higgs radiated from new heavy quarks also has large rates, but is much less
promising due to very high multiplicity final states.
|
[
{
"created": "Tue, 4 Aug 2009 23:27:22 GMT",
"version": "v1"
}
] |
2009-11-13
|
[
[
"Galloway",
"Jamison",
""
],
[
"McElrath",
"Bob",
""
],
[
"McRaven",
"John",
""
],
[
"Terning",
"John",
""
]
] |
The Gaugephobic Higgs model provides an interpolation between three different models of electroweak symmetry breaking: Higgsless models, Randall-Sundrum models, and the Standard Model. At parameter points between the extremes, Standard Model Higgs signals are present at reduced rates, and Higgsless Kaluza-Klein excitations are present with shifted masses and couplings, as well as signals from exotic quarks necessary to protect the Zbb coupling. Using a new implementation of the model in SHERPA, we show the LHC signals which differentiate the generic Gaugephobic Higgs model from its limiting cases. These are all signals involving a Higgs coupling to a Kaluza-Klein gauge boson or quark. We identify the clean signal $p p \to W^(i) \to W H$ mediated by a Kaluza-Klein W, which can be present at large rates and is enhanced for even Kaluza-Klein numbers. Due to the very hard lepton coming from the W decay, this signature has little background, and provides a better discovery channel for the Higgs than any of the Standard Model modes, over its entire mass range. A Higgs radiated from new heavy quarks also has large rates, but is much less promising due to very high multiplicity final states.
|
hep-ph/0203044
|
Alessandra Retico
|
Alessandra Retico
|
T-odd correlations in charged Kl4 decays
|
6 pages (LaTeX)
|
Phys.Rev.D65:117901,2002
|
10.1103/PhysRevD.65.117901
|
CERN-TH/2002-053
|
hep-ph
| null |
We analyse the sensitivity to physics beyond the SM of T-odd correlations in
$K_{\ell 4}$ decays, which do not involve the lepton polarization. We show that
a combined analysis of $K^+_{\mu 4}$ and $K^-_{\mu 4}$ decays can lead to new
constraints about CP violation in $\Delta S=1$ charged-current interactions,
complementary to those obtained from the transverse muon polarization in
$K_{\mu 3}$ and of comparable accuracy.
|
[
{
"created": "Tue, 5 Mar 2002 11:25:34 GMT",
"version": "v1"
}
] |
2014-11-17
|
[
[
"Retico",
"Alessandra",
""
]
] |
We analyse the sensitivity to physics beyond the SM of T-odd correlations in $K_{\ell 4}$ decays, which do not involve the lepton polarization. We show that a combined analysis of $K^+_{\mu 4}$ and $K^-_{\mu 4}$ decays can lead to new constraints about CP violation in $\Delta S=1$ charged-current interactions, complementary to those obtained from the transverse muon polarization in $K_{\mu 3}$ and of comparable accuracy.
|
hep-ph/0009293
|
Nuclear Physics
|
S. Arunagiri (U. Madras)
|
Spectator effects and quark-hadron duality in inclusive beauty decays
|
65+8 pages incl. 3 eps. Latex
| null | null | null |
hep-ph
| null |
The two important issues concerning the theory of inclusive decays are
studied: (1) evaluation of expectation values of four-quark operators in order
to systematically include the spectator effects and (2) estimation of duality
breaking corrections in heavy quark expansion. Our study leads to the
theoretical prediction of the ratio of lifetimes of $\Lambda_b$ and $B$ close
to the experimental one and the duality breaking corrections of about 10% of
the leading decay rate.
|
[
{
"created": "Tue, 26 Sep 2000 08:25:00 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Arunagiri",
"S.",
"",
"U. Madras"
]
] |
The two important issues concerning the theory of inclusive decays are studied: (1) evaluation of expectation values of four-quark operators in order to systematically include the spectator effects and (2) estimation of duality breaking corrections in heavy quark expansion. Our study leads to the theoretical prediction of the ratio of lifetimes of $\Lambda_b$ and $B$ close to the experimental one and the duality breaking corrections of about 10% of the leading decay rate.
|
1204.6333
|
Giuliano Panico
|
Oleksii Matsedonskyi, Giuliano Panico and Andrea Wulzer
|
Light Top Partners for a Light Composite Higgs
|
44 pages, 19 figures; v2: version published in JHEP
| null |
10.1007/JHEP01(2013)164
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Anomalously light fermionic partners of the top quark often appear in
explicit constructions, such as the 5d holographic models, where the Higgs is a
light composite pseudo Nambu-Goldstone boson and its potential is generated
radiatively by top quark loops. We show that this is due to a structural
correlation among the mass of the partners and the one of the Higgs boson.
Because of this correlation, the presence of light partners could be essential
to obtain a realistic Higgs mass.
We quantitatively confirm this generic prediction, which applies to a broad
class of composite Higgs models, by studying the simplest calculable framework
with a composite Higgs, the Discrete Composite Higgs Model. In this setup we
show analytically that the requirement of a light enough Higgs strongly
constraints the fermionic spectrum and makes the light partners appear.
The light top partners thus provide the most promising manifestation of the
composite Higgs scenario at the LHC. Conversely, the lack of observation of
these states can put strong restrictions on the parameter space of the model. A
simple analysis of the 7-TeV LHC searches presently available already gives
some non-trivial constraint. The strongest bound comes from the exclusion of
the 5/3-charged partner. Even if no dedicated LHC search exists for this
particle, a bound of 611 GeV is derived by adapting the CMS search of
bottom-like states in same-sign dileptons.
|
[
{
"created": "Fri, 27 Apr 2012 20:48:58 GMT",
"version": "v1"
},
{
"created": "Fri, 25 Jan 2013 12:22:36 GMT",
"version": "v2"
}
] |
2015-06-04
|
[
[
"Matsedonskyi",
"Oleksii",
""
],
[
"Panico",
"Giuliano",
""
],
[
"Wulzer",
"Andrea",
""
]
] |
Anomalously light fermionic partners of the top quark often appear in explicit constructions, such as the 5d holographic models, where the Higgs is a light composite pseudo Nambu-Goldstone boson and its potential is generated radiatively by top quark loops. We show that this is due to a structural correlation among the mass of the partners and the one of the Higgs boson. Because of this correlation, the presence of light partners could be essential to obtain a realistic Higgs mass. We quantitatively confirm this generic prediction, which applies to a broad class of composite Higgs models, by studying the simplest calculable framework with a composite Higgs, the Discrete Composite Higgs Model. In this setup we show analytically that the requirement of a light enough Higgs strongly constraints the fermionic spectrum and makes the light partners appear. The light top partners thus provide the most promising manifestation of the composite Higgs scenario at the LHC. Conversely, the lack of observation of these states can put strong restrictions on the parameter space of the model. A simple analysis of the 7-TeV LHC searches presently available already gives some non-trivial constraint. The strongest bound comes from the exclusion of the 5/3-charged partner. Even if no dedicated LHC search exists for this particle, a bound of 611 GeV is derived by adapting the CMS search of bottom-like states in same-sign dileptons.
|
1808.05461
|
Shuzhe Shi
|
Shuzhe Shi, Jinfeng Liao, Miklos Gyulassy
|
Global Constraints from RHIC and LHC on Transport Properties of QCD
Fluids in CUJET/CIBJET Framework
|
35 pages, 28 figures. Published version. Previously entitled "Global
$\chi^2$ RHIC and LHC Data Constraints on Soft-Hard Transport Properties of
semi-Quark-Gluon-Monopole Plasmas with the CUJET3.1 Framework"
|
Chin.Phys. C43 (2019) no.4, 044101
|
10.1088/1674-1137/43/4/044101
| null |
hep-ph hep-lat
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We report results of a comprehensive global $\chi^2$ analysis of nuclear
collision data from RHIC (0.2 ATeV), LHC1 (2.76 ATeV), and recent LHC2 (5.02
ATeV) energies using the updated CUJET framework. The framework consistently
combines viscous hydrodynamic fields predicted by VISHNU2+1 (validated with
soft $p_T<2$~GeV bulk observables) and the DGLV theory of jet elastic and
inelastic energy loss generalized to QGP fluids with an sQGMP color structure,
including effective semi-QGP color electric quark and gluon as well as emergent
color magnetic monopole degrees of freedom constrained by lattice QCD data. We
vary the two control parameters of the model (the maximum value of the running
QCD coupling, $\alpha_c$, and the ratio $c_m$ of color magnetic to electric
screening scales) and calculate the global $\chi^2(\alpha_c,c_m)$ compared with
available jet fragment observables ($R_{AA}, v_2$). A global $\chi^2<2$ minimum
is found with $\alpha_c \approx 0.9\pm 0.1$ and $c_m\approx 0.25\pm 0.03$.
Using CIBJET, the event-by-event (ebe) generalization of the CUJET framework,
we show that ebe fluctuations in the initial conditions do not significantly
alter our conclusions (except for $v_3$). An important theoretical advantage of
the CUJET and CIBJET frameworks is not only its global $\chi^2$ consistency
with jet fragment observables at RHIC and LHC and with non-perturbative lattice
QCD data, but also its internal consistency of the constrained jet transport
coefficient, $\hat{q}(E,T)/T^3$, with the near-perfect fluid viscosity to
entropy ratio ($\eta/s \sim T^3/\hat{q}\sim 0.1-0.2$) property of QCD fluids
near $T_c$ needed to account for the low $p_T<2$ GeV flow observables.
Predictions for future tests at LHC with 5.44 ATeV Xe + Xe and 5.02 ATeV Pb +
Pb are also presented.
|
[
{
"created": "Thu, 16 Aug 2018 13:28:00 GMT",
"version": "v1"
},
{
"created": "Mon, 15 Apr 2019 16:07:20 GMT",
"version": "v2"
}
] |
2019-04-16
|
[
[
"Shi",
"Shuzhe",
""
],
[
"Liao",
"Jinfeng",
""
],
[
"Gyulassy",
"Miklos",
""
]
] |
We report results of a comprehensive global $\chi^2$ analysis of nuclear collision data from RHIC (0.2 ATeV), LHC1 (2.76 ATeV), and recent LHC2 (5.02 ATeV) energies using the updated CUJET framework. The framework consistently combines viscous hydrodynamic fields predicted by VISHNU2+1 (validated with soft $p_T<2$~GeV bulk observables) and the DGLV theory of jet elastic and inelastic energy loss generalized to QGP fluids with an sQGMP color structure, including effective semi-QGP color electric quark and gluon as well as emergent color magnetic monopole degrees of freedom constrained by lattice QCD data. We vary the two control parameters of the model (the maximum value of the running QCD coupling, $\alpha_c$, and the ratio $c_m$ of color magnetic to electric screening scales) and calculate the global $\chi^2(\alpha_c,c_m)$ compared with available jet fragment observables ($R_{AA}, v_2$). A global $\chi^2<2$ minimum is found with $\alpha_c \approx 0.9\pm 0.1$ and $c_m\approx 0.25\pm 0.03$. Using CIBJET, the event-by-event (ebe) generalization of the CUJET framework, we show that ebe fluctuations in the initial conditions do not significantly alter our conclusions (except for $v_3$). An important theoretical advantage of the CUJET and CIBJET frameworks is not only its global $\chi^2$ consistency with jet fragment observables at RHIC and LHC and with non-perturbative lattice QCD data, but also its internal consistency of the constrained jet transport coefficient, $\hat{q}(E,T)/T^3$, with the near-perfect fluid viscosity to entropy ratio ($\eta/s \sim T^3/\hat{q}\sim 0.1-0.2$) property of QCD fluids near $T_c$ needed to account for the low $p_T<2$ GeV flow observables. Predictions for future tests at LHC with 5.44 ATeV Xe + Xe and 5.02 ATeV Pb + Pb are also presented.
|
hep-ph/0508314
|
Alakabha Datta
|
Alakabha Datta and Patrick J. O'Donnell
|
The 2-3 symmetry: Flavour Changing $b$, $\tau$ Decays and Neutrino
Mixing
|
21 pages, no figures. Reorganization and addition of text. Reference
added and misprints corrected. Conclusions unchanged. Accepted for
publication
|
Phys.Rev. D72 (2005) 113002
|
10.1103/PhysRevD.72.113002
| null |
hep-ph hep-ex
| null |
The observed pattern of neutrino mixing may be the result of a 2-3($ \mu-
\tau$) symmetry in the leptonic sector. We consider a two Higgs doublet model
with a 2-3 symmetry in the down type quark and the charged lepton sector. The
breaking of the 2-3 symmetry by the strange quark mass and the muon mass leads
to FCNC in the quark sector and the charged lepton sector that are suppressed
by ${m_s \over m_b}$ and ${m_{\mu} \over m_{\tau}}$ in addition to the mass of
the heavy Higgs boson of the second Higgs doublet. A Higgs boson mass of $ m_H
\sim 600 - 900$ GeV can explain the deviation from standard model reported in
several rare B decays. Predictions for other B decays are made and a new CP
phase is predicted in $B_{s}-{\bar{B}_{s}}$ mixing. The lepton flavour
violating decays $ \tau \to \mu \bar{l}(\bar{q}) l(q)$ are below the
experimental limits. The breaking of 2-3 symmetry in the lepton sector can lead
to deviations of the atmospheric neutrino mixing angle from the maximal value
by $ \sim 2$ degrees.
|
[
{
"created": "Wed, 31 Aug 2005 13:30:51 GMT",
"version": "v1"
},
{
"created": "Thu, 8 Sep 2005 22:22:53 GMT",
"version": "v2"
},
{
"created": "Wed, 23 Nov 2005 22:44:55 GMT",
"version": "v3"
}
] |
2009-11-11
|
[
[
"Datta",
"Alakabha",
""
],
[
"O'Donnell",
"Patrick J.",
""
]
] |
The observed pattern of neutrino mixing may be the result of a 2-3($ \mu- \tau$) symmetry in the leptonic sector. We consider a two Higgs doublet model with a 2-3 symmetry in the down type quark and the charged lepton sector. The breaking of the 2-3 symmetry by the strange quark mass and the muon mass leads to FCNC in the quark sector and the charged lepton sector that are suppressed by ${m_s \over m_b}$ and ${m_{\mu} \over m_{\tau}}$ in addition to the mass of the heavy Higgs boson of the second Higgs doublet. A Higgs boson mass of $ m_H \sim 600 - 900$ GeV can explain the deviation from standard model reported in several rare B decays. Predictions for other B decays are made and a new CP phase is predicted in $B_{s}-{\bar{B}_{s}}$ mixing. The lepton flavour violating decays $ \tau \to \mu \bar{l}(\bar{q}) l(q)$ are below the experimental limits. The breaking of 2-3 symmetry in the lepton sector can lead to deviations of the atmospheric neutrino mixing angle from the maximal value by $ \sim 2$ degrees.
|
hep-ph/9812343
|
Helen Bukina
|
E.N. Bukina
|
Octet Magnetic Moments with Null Instantons and Semibosonized
Nambu-Jona-Lasinio Model
|
RevTex, 6 pages, submitted to Progr.Theor.Phys
|
Mod.Phys.Lett. A14 (1999) 2525-2530
|
10.1142/S0217732399002637
| null |
hep-ph
| null |
It is shown that the difference between the magnetic moment results in the
quark model with null instantons and semibosonized Nambu-Jona-Lasinio model
lies in the description of the magnetic moment of the $ \Lambda$-hyperon.
|
[
{
"created": "Sat, 12 Dec 1998 13:40:30 GMT",
"version": "v1"
}
] |
2009-10-31
|
[
[
"Bukina",
"E. N.",
""
]
] |
It is shown that the difference between the magnetic moment results in the quark model with null instantons and semibosonized Nambu-Jona-Lasinio model lies in the description of the magnetic moment of the $ \Lambda$-hyperon.
|
2109.03800
|
Bruce Mellado
|
Bruce Mellado
|
The anatomy of the multilepton anomalies at the LHC and a candidate for
a singlet scalar
|
6 pages, 1 figure. Based on presentations given at PHENO2021,
Lomonosov2021, ICNFP2021 and SAIP2021
| null | null |
ICPP-058
|
hep-ph hep-ex
|
http://creativecommons.org/licenses/by/4.0/
|
In this presentation an account of the multi-lepton (electrons and muons)
anomalies at the LHC is given. These include the excess production of opposite
sign leptons with and without b-quarks, including a corner of the phase-space
with a full hadronic jet veto; same sign leptons with and without b-quarks;
three leptons with and without b-quarks, including also the presence of a $Z$.
Excesses emerge in corners of the phase space where a range of SM processes
dominate, indicating that the potential mismodeling of a particular SM process
is unlikely to explain them. A procedure is implemented that avoids parameter
tuning or scanning the phase-space in order to nullify potential
look-else-where effects or selection biases. The internal consistency of these
anomalies and their interpretation in the framework of a simplified model are
presented. Motivated by the multi-lepton anomalies, a search for narrow
resonances with $S\rightarrow\gamma\gamma, Z\gamma$ in association with light
jets, $b$-jets or missing transverse energy is performed. The maximum local
(global) significance is achieved for $m_S=151.5$\,GeV with 5.1$\sigma$
(4.8$\sigma$).
|
[
{
"created": "Wed, 8 Sep 2021 17:42:33 GMT",
"version": "v1"
}
] |
2021-09-09
|
[
[
"Mellado",
"Bruce",
""
]
] |
In this presentation an account of the multi-lepton (electrons and muons) anomalies at the LHC is given. These include the excess production of opposite sign leptons with and without b-quarks, including a corner of the phase-space with a full hadronic jet veto; same sign leptons with and without b-quarks; three leptons with and without b-quarks, including also the presence of a $Z$. Excesses emerge in corners of the phase space where a range of SM processes dominate, indicating that the potential mismodeling of a particular SM process is unlikely to explain them. A procedure is implemented that avoids parameter tuning or scanning the phase-space in order to nullify potential look-else-where effects or selection biases. The internal consistency of these anomalies and their interpretation in the framework of a simplified model are presented. Motivated by the multi-lepton anomalies, a search for narrow resonances with $S\rightarrow\gamma\gamma, Z\gamma$ in association with light jets, $b$-jets or missing transverse energy is performed. The maximum local (global) significance is achieved for $m_S=151.5$\,GeV with 5.1$\sigma$ (4.8$\sigma$).
|
hep-ph/9503323
| null |
B. Ananthanarayan and P. N. Pandita
|
The Non-Minimal Supersymmetric Standard Model with $\tan\beta\simeq
m_t/m_b$
|
22 pages plain LaTeX including 1 Table and 1 Figure
|
Phys.Lett.B353:70-78,1995
|
10.1016/0370-2693(95)00517-O
|
UNIL-TP-1/95, NORDITA - 95/20 P
|
hep-ph
| null |
We consider the supersymmetric extension of the standard model with an
additional singlet $S$, the Non-Minimal Supersymmetric Standard Model (NMSSM),
in the limit $\tan\beta \simeq m_t/m_b$. We embed this model in a supergravity
framework with universal boundary conditions and analyze the renormalization
group improved tree-level potential. We examine the relationship between this
model and the minimial supersymmetric standard model (MSSM), and discuss the
novel connections between the two when $\tan\beta$ is large. Strong
correlations between the free parameters of the nonminimal model are found and
the reasons for these discussed. The singlet vacuum expectation value is forced
to be large, of the order of $10 TeV$. The radiatively corrected mass of the
lightest Higgs boson is found to be $\stackrel{_<}{_\sim} 140 GeV$.
|
[
{
"created": "Tue, 14 Mar 1995 14:31:18 GMT",
"version": "v1"
}
] |
2008-12-22
|
[
[
"Ananthanarayan",
"B.",
""
],
[
"Pandita",
"P. N.",
""
]
] |
We consider the supersymmetric extension of the standard model with an additional singlet $S$, the Non-Minimal Supersymmetric Standard Model (NMSSM), in the limit $\tan\beta \simeq m_t/m_b$. We embed this model in a supergravity framework with universal boundary conditions and analyze the renormalization group improved tree-level potential. We examine the relationship between this model and the minimial supersymmetric standard model (MSSM), and discuss the novel connections between the two when $\tan\beta$ is large. Strong correlations between the free parameters of the nonminimal model are found and the reasons for these discussed. The singlet vacuum expectation value is forced to be large, of the order of $10 TeV$. The radiatively corrected mass of the lightest Higgs boson is found to be $\stackrel{_<}{_\sim} 140 GeV$.
|
1808.06631
|
Hazhar Ghaderi
|
Andreas Ekstedt, Hazhar Ghaderi, Gunnar Ingelman and Stefan Leupold
(Uppsala University)
|
Towards solving the proton spin puzzle
|
More figs and refs
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The fact that the spins of the quarks in the proton, as measured in deep
inelastic lepton scattering, only add up to about 30$\%$ of the spin of the
proton is still not understood after 30 years. We show that our newly developed
model for the quark and gluon momentum distributions in the proton, based on
quantum fluctuations of the proton into baryon-meson pairs convoluted with
Gaussian momentum distributions of partons in hadrons, can essentially
reproduce the data on the proton spin structure function $g_1^P(x)$ and the
associated spin asymmetry. A further improved description of the data is
achieved by also including the relativistic correction of the Melosh
transformation to the light-front formalism used in deep inelastic scattering.
However, this does not fully resolve the spin puzzle, including also the
neutron spin structure and the spin sum rules. These aspects can also be
accounted for by our few-parameter model if the conventional SU(6) flavor-spin
symmetry is broken, giving new information on the non-perturbative bound-state
nucleon.
|
[
{
"created": "Mon, 20 Aug 2018 18:06:14 GMT",
"version": "v1"
},
{
"created": "Wed, 19 Jun 2019 20:01:21 GMT",
"version": "v2"
}
] |
2019-06-21
|
[
[
"Ekstedt",
"Andreas",
"",
"Uppsala University"
],
[
"Ghaderi",
"Hazhar",
"",
"Uppsala University"
],
[
"Ingelman",
"Gunnar",
"",
"Uppsala University"
],
[
"Leupold",
"Stefan",
"",
"Uppsala University"
]
] |
The fact that the spins of the quarks in the proton, as measured in deep inelastic lepton scattering, only add up to about 30$\%$ of the spin of the proton is still not understood after 30 years. We show that our newly developed model for the quark and gluon momentum distributions in the proton, based on quantum fluctuations of the proton into baryon-meson pairs convoluted with Gaussian momentum distributions of partons in hadrons, can essentially reproduce the data on the proton spin structure function $g_1^P(x)$ and the associated spin asymmetry. A further improved description of the data is achieved by also including the relativistic correction of the Melosh transformation to the light-front formalism used in deep inelastic scattering. However, this does not fully resolve the spin puzzle, including also the neutron spin structure and the spin sum rules. These aspects can also be accounted for by our few-parameter model if the conventional SU(6) flavor-spin symmetry is broken, giving new information on the non-perturbative bound-state nucleon.
|
0707.0020
|
Sogee Spinner
|
R. N. Mohapatra, N. Setzer and S. Spinner
|
Minimal Seesaw as an Ultraviolet Insensitive Cure for the Problems of
Anomaly Mediation
|
19 pages, 1 figure
|
Phys.Rev.D77:053013,2008
|
10.1103/PhysRevD.77.053013
| null |
hep-ph hep-th
| null |
We show that an intermediate scale supersymmetric left-right seesaw scenario
with automatic R-parity conservation can cure the problem of tachyonic slepton
masses that arises when supersymmetry is broken by anomaly mediation, while
preserving ultraviolet insensitivity. The reason for this is the existence of
light B - L = 2 higgses with yukawa couplings to the charged leptons. We find
these theories to have distinct predictions compared to the usual mSUGRA and
gauge mediated models as well as the minimal AMSB models. Such predictions
include a condensed gaugino mass spectrum and possibly a correspondingly
condensed sfermion spectrum.
|
[
{
"created": "Mon, 2 Jul 2007 16:58:12 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Mohapatra",
"R. N.",
""
],
[
"Setzer",
"N.",
""
],
[
"Spinner",
"S.",
""
]
] |
We show that an intermediate scale supersymmetric left-right seesaw scenario with automatic R-parity conservation can cure the problem of tachyonic slepton masses that arises when supersymmetry is broken by anomaly mediation, while preserving ultraviolet insensitivity. The reason for this is the existence of light B - L = 2 higgses with yukawa couplings to the charged leptons. We find these theories to have distinct predictions compared to the usual mSUGRA and gauge mediated models as well as the minimal AMSB models. Such predictions include a condensed gaugino mass spectrum and possibly a correspondingly condensed sfermion spectrum.
|
hep-ph/0604127
|
YaJin Zhou
|
Zhou Ya-Jin, Ma Wen-Gan, Zhang Ren-You, Jiang Yi, and Han Liang
|
Electroweak radiative corrections to the Higgs-boson production in
association with $Z^0$-boson pair at $e^+ e^-$ colliders
|
19 pages, 7 figures, to be published on Phys. ReV. D
|
Phys.Rev. D73 (2006) 073009
|
10.1103/PhysRevD.73.073009
| null |
hep-ph
| null |
We present the full ${\cal O}(\alpha_{{ew}})$ electroweak radiative
corrections to the Higgs-boson production in association with $Z^0$-boson pair
at an electron-positron linear collider(LC) in the standard model. We analyze
the dependence of the full one-loop corrections on the Higgs-boson mass $m_{H}$
and colliding energy $\sqrt{s}$. We find that the corrections significantly
suppress the Born cross section, and the ${\cal O}(\alpha_{{ew}})$ electroweak
radiative corrections are generally between 1.0% and -15% in our chosen
parameter space, which should be taken into consideration in the future precise
experiments.
|
[
{
"created": "Fri, 14 Apr 2006 02:42:29 GMT",
"version": "v1"
}
] |
2009-11-11
|
[
[
"Ya-Jin",
"Zhou",
""
],
[
"Wen-Gan",
"Ma",
""
],
[
"Ren-You",
"Zhang",
""
],
[
"Yi",
"Jiang",
""
],
[
"Liang",
"Han",
""
]
] |
We present the full ${\cal O}(\alpha_{{ew}})$ electroweak radiative corrections to the Higgs-boson production in association with $Z^0$-boson pair at an electron-positron linear collider(LC) in the standard model. We analyze the dependence of the full one-loop corrections on the Higgs-boson mass $m_{H}$ and colliding energy $\sqrt{s}$. We find that the corrections significantly suppress the Born cross section, and the ${\cal O}(\alpha_{{ew}})$ electroweak radiative corrections are generally between 1.0% and -15% in our chosen parameter space, which should be taken into consideration in the future precise experiments.
|
2111.08767
|
Samiran Roy
|
Kaustav Chakraborty, Arindam Das, Srubabati Goswami, Samiran Roy
|
Constraining general U(1) interactions from neutrino-electron scattering
measurements at DUNE near detector
|
21 pages, 6 figures, 2 tables, matches accepted version in JHEP
|
JHEP 04 (2022) 008
|
10.1007/JHEP04(2022)008
| null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
The neutrino-electron scattering process is a powerful tool to explore new
physics beyond the standard model. Recently the possibility of DUNE Near
Detector (ND) to constrain various new physics scenarios using this process
have been highlighted in the literature. In this work, we consider the most
general U(1) model and probe the constraints on the mass and coupling strength
of the additional $Z'$ from $\nu-e$ scattering at DUNE ND. The presence of the
$Z^\prime$ gives rise to extra interference effects. In the context of the
general U(1) model, the destructive interference can occur in either neutrino
or anti-neutrino channel or for both or none. This opens up the possibilities
of getting four different type of signal in the neutrino and ant-neutrino runs
of DUNE. We perform the analysis using both the total rate and binned events
spectrum. Our results show that in a bin by bin analysis the effect of
destructive interference is less compared to the analysis using total rate. We
present the bounds on the $ m_{Z^\prime} - g_X$ plane from $\nu-e$ scattering
measurements at DUNE ND and compare these with those obtained from other
$\nu-e$ scattering, COHERENT, and beam dump experiments. We show that the DUNE
ND can give the best bound for certain mass ranges of $Z^\prime$.
|
[
{
"created": "Tue, 16 Nov 2021 20:36:15 GMT",
"version": "v1"
},
{
"created": "Tue, 5 Apr 2022 10:06:22 GMT",
"version": "v2"
}
] |
2022-04-06
|
[
[
"Chakraborty",
"Kaustav",
""
],
[
"Das",
"Arindam",
""
],
[
"Goswami",
"Srubabati",
""
],
[
"Roy",
"Samiran",
""
]
] |
The neutrino-electron scattering process is a powerful tool to explore new physics beyond the standard model. Recently the possibility of DUNE Near Detector (ND) to constrain various new physics scenarios using this process have been highlighted in the literature. In this work, we consider the most general U(1) model and probe the constraints on the mass and coupling strength of the additional $Z'$ from $\nu-e$ scattering at DUNE ND. The presence of the $Z^\prime$ gives rise to extra interference effects. In the context of the general U(1) model, the destructive interference can occur in either neutrino or anti-neutrino channel or for both or none. This opens up the possibilities of getting four different type of signal in the neutrino and ant-neutrino runs of DUNE. We perform the analysis using both the total rate and binned events spectrum. Our results show that in a bin by bin analysis the effect of destructive interference is less compared to the analysis using total rate. We present the bounds on the $ m_{Z^\prime} - g_X$ plane from $\nu-e$ scattering measurements at DUNE ND and compare these with those obtained from other $\nu-e$ scattering, COHERENT, and beam dump experiments. We show that the DUNE ND can give the best bound for certain mass ranges of $Z^\prime$.
|
1803.08051
|
Kohei Kamada
|
Kohei Kamada, Yuhsin Tsai, Tanmay Vachaspati
|
Magnetic Field Transfer From A Hidden Sector
|
26 pages, 2 figures
|
Phys. Rev. D 98, 043501 (2018)
|
10.1103/PhysRevD.98.043501
|
CTPU-PTC-18-06
|
hep-ph astro-ph.CO
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Primordial magnetic fields in the dark sector can be transferred to magnetic
fields in the visible sector due to a gauge kinetic mixing term. We show that
the transfer occurs when the evolution of magnetic fields is dominated by
dissipation due to finite electric conductivity, and does not occur at later
times if the magnetic fields evolve according to magnetohydrodynamics scaling
laws. The efficiency of the transfer is suppressed by not only the gauge
kinetic mixing coupling but also the ratio between the large electric
conductivity and the typical momentum of the magnetic fields. We find that the
transfer gives nonzero visible magnetic fields today. However, without possible
dynamo amplifications, the field transfer is not efficient enough to obtain the
intergalactic magnetic fields suggested by the gamma-ray observations, although
there are plenty of possibilities for efficient dark magnetogenesis, which are
experimentally unconstrained.
|
[
{
"created": "Wed, 21 Mar 2018 18:00:02 GMT",
"version": "v1"
}
] |
2018-08-08
|
[
[
"Kamada",
"Kohei",
""
],
[
"Tsai",
"Yuhsin",
""
],
[
"Vachaspati",
"Tanmay",
""
]
] |
Primordial magnetic fields in the dark sector can be transferred to magnetic fields in the visible sector due to a gauge kinetic mixing term. We show that the transfer occurs when the evolution of magnetic fields is dominated by dissipation due to finite electric conductivity, and does not occur at later times if the magnetic fields evolve according to magnetohydrodynamics scaling laws. The efficiency of the transfer is suppressed by not only the gauge kinetic mixing coupling but also the ratio between the large electric conductivity and the typical momentum of the magnetic fields. We find that the transfer gives nonzero visible magnetic fields today. However, without possible dynamo amplifications, the field transfer is not efficient enough to obtain the intergalactic magnetic fields suggested by the gamma-ray observations, although there are plenty of possibilities for efficient dark magnetogenesis, which are experimentally unconstrained.
|
0812.4624
|
Juan Garcia-Bellido
|
Juan Garcia-Bellido, Daniel G. Figueroa and Javier Rubio
|
Preheating in the Standard Model with the Higgs-Inflaton coupled to
gravity
|
27 pages, 6 figures; corrected typos, added references
|
Phys.Rev.D79:063531,2009
|
10.1103/PhysRevD.79.063531
|
IFT-UAM/CSIC-08-93
|
hep-ph astro-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study the details of preheating in an inflationary scenario in which the
Standard Model Higgs, strongly non-minimally coupled to gravity, plays the role
of the inflaton. We find that the Universe does not reheat immediately through
perturbative decays, but rather initiate a complex process in which
perturbative and non-perturbative effects are mixed. The Higgs condesate starts
oscillating around the minimum of its potential, producing W and Z gauge bosons
non-perturbatively, due to violation of the so-called adiabaticity condition.
However, during each semi-oscillation, the created gauge bosons completely
decay (perturbatively) into fermions. This way, the decay of the gauge bosons
prevents the development of parametric resonance, since bosons cannot
accummulate significantly at the beginning. However, the energy transferred to
the decay products of the bosons is not enough to reheat the universe, so after
about a hundred oscillations, the resonance effect will finally dominate over
the perturbative decays. Around the same time (or slightly earlier),
backreaction from the gauge bosons onto the Higgs condensate will also start to
be significant. Soon afterwards, the Universe is filled with the remnant
condensate of the Higgs and a non-thermal distribution of Standard Model
particles which redshift as radiation, while the Higgs continues to oscillate
as a pressureless fluid. We compute the distribution of energy among all the
species present at backreaction. From there on until thermalization, the
evolution of the system is highly non-linear and non-perturbative, and will
require a careful study via numerical simulations.
|
[
{
"created": "Thu, 25 Dec 2008 19:33:07 GMT",
"version": "v1"
},
{
"created": "Thu, 22 Jan 2009 17:52:27 GMT",
"version": "v2"
}
] |
2014-11-18
|
[
[
"Garcia-Bellido",
"Juan",
""
],
[
"Figueroa",
"Daniel G.",
""
],
[
"Rubio",
"Javier",
""
]
] |
We study the details of preheating in an inflationary scenario in which the Standard Model Higgs, strongly non-minimally coupled to gravity, plays the role of the inflaton. We find that the Universe does not reheat immediately through perturbative decays, but rather initiate a complex process in which perturbative and non-perturbative effects are mixed. The Higgs condesate starts oscillating around the minimum of its potential, producing W and Z gauge bosons non-perturbatively, due to violation of the so-called adiabaticity condition. However, during each semi-oscillation, the created gauge bosons completely decay (perturbatively) into fermions. This way, the decay of the gauge bosons prevents the development of parametric resonance, since bosons cannot accummulate significantly at the beginning. However, the energy transferred to the decay products of the bosons is not enough to reheat the universe, so after about a hundred oscillations, the resonance effect will finally dominate over the perturbative decays. Around the same time (or slightly earlier), backreaction from the gauge bosons onto the Higgs condensate will also start to be significant. Soon afterwards, the Universe is filled with the remnant condensate of the Higgs and a non-thermal distribution of Standard Model particles which redshift as radiation, while the Higgs continues to oscillate as a pressureless fluid. We compute the distribution of energy among all the species present at backreaction. From there on until thermalization, the evolution of the system is highly non-linear and non-perturbative, and will require a careful study via numerical simulations.
|
2309.05110
|
Anke Lei
|
An-Ke Lei, Yu-Liang Yan, Dai-Mei Zhou, Zhi-Lei She, Liang Zheng,
Gao-Chan Yong, Xiao-Mei Li, Gang Chen, Xu Cai, and Ben-Hao Sa
|
An introduction to the parton and hadron cascade model PACIAE 3.0
|
15 pages, 15 figures
| null | null | null |
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We introduce a parton and hadron cascade model PACIAE 3.0 based on PYTHIA
6.428 and the PACIAE 2.2 program series. The simulation framework of C-, B-,
and A-loops are designed for the high energy ($\sqrt{s_{NN}}\geq 3$ GeV) and
low energy ($\sqrt{s_{NN}}<3$ GeV) nuclear collisions, respectively, in PACIAE
3.0. In the C-loop simulation, the parton-parton inelastic scattering processes
are added in the partonic rescattering process. The single string structure and
multiple string interaction mechanism have been introduced investigating the
strangeness enhancement in C- and B-loop. An improved mapping relation between
the centrality percentage definition and the impact parameter definition is
proposed responding the observation of $b_{max}\approx 20$ fm from ALICE,
ATLAS, and CMS collaborations. We have extensively modified the
phenomenological coalescence hadronization model. The PACIAE 3.0 model
simulated results of particle yield, transverse momentum distribution, and
rapidity distribution well reproduce, respectively, the experimental data
measured at FOPI, E895, RHIC, and LHC energies.
|
[
{
"created": "Sun, 10 Sep 2023 18:34:05 GMT",
"version": "v1"
}
] |
2023-09-12
|
[
[
"Lei",
"An-Ke",
""
],
[
"Yan",
"Yu-Liang",
""
],
[
"Zhou",
"Dai-Mei",
""
],
[
"She",
"Zhi-Lei",
""
],
[
"Zheng",
"Liang",
""
],
[
"Yong",
"Gao-Chan",
""
],
[
"Li",
"Xiao-Mei",
""
],
[
"Chen",
"Gang",
""
],
[
"Cai",
"Xu",
""
],
[
"Sa",
"Ben-Hao",
""
]
] |
We introduce a parton and hadron cascade model PACIAE 3.0 based on PYTHIA 6.428 and the PACIAE 2.2 program series. The simulation framework of C-, B-, and A-loops are designed for the high energy ($\sqrt{s_{NN}}\geq 3$ GeV) and low energy ($\sqrt{s_{NN}}<3$ GeV) nuclear collisions, respectively, in PACIAE 3.0. In the C-loop simulation, the parton-parton inelastic scattering processes are added in the partonic rescattering process. The single string structure and multiple string interaction mechanism have been introduced investigating the strangeness enhancement in C- and B-loop. An improved mapping relation between the centrality percentage definition and the impact parameter definition is proposed responding the observation of $b_{max}\approx 20$ fm from ALICE, ATLAS, and CMS collaborations. We have extensively modified the phenomenological coalescence hadronization model. The PACIAE 3.0 model simulated results of particle yield, transverse momentum distribution, and rapidity distribution well reproduce, respectively, the experimental data measured at FOPI, E895, RHIC, and LHC energies.
|
1805.05740
|
Yuki Shimizu
|
Yuki Shimizu, Yasuhiro Yamaguchi, Masayasu Harada
|
Heavy quark spin multiplet structure of $\bar{P}^{(*)}\Sigma_Q^{(*)}$
molecular states
|
9 pages, 6 figures
|
Phys. Rev. D 98, 014021 (2018)
|
10.1103/PhysRevD.98.014021
|
RIKEN-QHP-371, RIKEN-iTHEMS-Report-18
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study the structure of heavy quark spin (HQS) multiplets for heavy
meson-baryon molecular states in a coupled system of
$\bar{P}^{(*)}\Sigma_{Q}^{(*)}$, with constructing the one-pion exchange
potential with S-wave orbital angular momentum. Using the light cloud spin
basis, we find that there are four types of HQS multiplets classified by the
structure of heavy quark spin and light cloud spin. The multiplets which have
attractive potential are determined by the sign of the coupling constant for
the heavy meson-pion interactions. Furthermore, the difference in the structure
of light cloud spin gives the restrictions of the decay channel, which implies
that the partial decay width has the information for the structure of HQS
multiplets. This behavior is more likely to appear in hidden-bottom sector than
in hidden-charm sector.
|
[
{
"created": "Tue, 15 May 2018 12:55:52 GMT",
"version": "v1"
}
] |
2018-07-25
|
[
[
"Shimizu",
"Yuki",
""
],
[
"Yamaguchi",
"Yasuhiro",
""
],
[
"Harada",
"Masayasu",
""
]
] |
We study the structure of heavy quark spin (HQS) multiplets for heavy meson-baryon molecular states in a coupled system of $\bar{P}^{(*)}\Sigma_{Q}^{(*)}$, with constructing the one-pion exchange potential with S-wave orbital angular momentum. Using the light cloud spin basis, we find that there are four types of HQS multiplets classified by the structure of heavy quark spin and light cloud spin. The multiplets which have attractive potential are determined by the sign of the coupling constant for the heavy meson-pion interactions. Furthermore, the difference in the structure of light cloud spin gives the restrictions of the decay channel, which implies that the partial decay width has the information for the structure of HQS multiplets. This behavior is more likely to appear in hidden-bottom sector than in hidden-charm sector.
|
1701.04646
|
Wei Liao
|
Wei Liao
|
Strong CP Problem and spontaneous generation of CP violating phase in
CKM matrix
|
17 pages, version for publication in PRD
|
Phys. Rev. D 95, 095020 (2017)
|
10.1103/PhysRevD.95.095020
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We show that in a Complementary two-Higgs doublet model(C2HDM) the CP
violating phase in the CKM matrix can be generated spontaneously, dangerous
FCNC can be naturally suppressed and the strong CP problem can also be avoided.
The two Higgs doublets in the model are complementary in the sense that none of
them is enough to describe masses of a given type of quarks. We find that the
strength of FCNC is suppressed by the strength of Yukawa couplings of the first
generation quark and the tree-level FCNC is sufficiently small. Using an
explicit example, we show that radiative correction to the assumed Yukawa
couplings can modify the discussion about the strong $\theta$. The correction
to the strong $\theta$ is estimated to be less than around
$10^{-12}\sim10^{-10}$ which can be tested in future experiment.
|
[
{
"created": "Tue, 17 Jan 2017 12:38:53 GMT",
"version": "v1"
},
{
"created": "Sun, 22 Jan 2017 09:54:34 GMT",
"version": "v2"
},
{
"created": "Thu, 4 May 2017 03:45:09 GMT",
"version": "v3"
}
] |
2017-05-31
|
[
[
"Liao",
"Wei",
""
]
] |
We show that in a Complementary two-Higgs doublet model(C2HDM) the CP violating phase in the CKM matrix can be generated spontaneously, dangerous FCNC can be naturally suppressed and the strong CP problem can also be avoided. The two Higgs doublets in the model are complementary in the sense that none of them is enough to describe masses of a given type of quarks. We find that the strength of FCNC is suppressed by the strength of Yukawa couplings of the first generation quark and the tree-level FCNC is sufficiently small. Using an explicit example, we show that radiative correction to the assumed Yukawa couplings can modify the discussion about the strong $\theta$. The correction to the strong $\theta$ is estimated to be less than around $10^{-12}\sim10^{-10}$ which can be tested in future experiment.
|
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