201 research outputs found
Electroweak symmetry breaking and cold dark matter from hidden sector technicolor
We consider models with a vectorlike confining gauge theory in the hidden
sector, and demonstrate that the origin of the electroweak symmetry breaking
(EWSB) is due to the dimensional transmutation in the hidden sector gauge
theory, and the lightest mesons in the hidden sector could be a good cold dark
matter (CDM) candidate. There would be more than one neutral Higgs-like scalar
bosons, and they could decay mainly into the CDM pair, if that decay channel is
kinemtically allowed.Comment: To appear in the proceeding of the 4th International Conference on
Flavor Physic
A simple modification of the maximal mixing scenario for three light neutrinos
We suggest a simple modification of the maximal mixing scenario (with
permutation symmetry) for three light neutrinos. Our neutrino mass matrix has
smaller permutation symmetry (), and
is consistent with all neutrino experiments except the Cl experiment.
The resulting mass eigenvalues for three neutrinos are for . Then these light neutrinos can account for
of the dark matter for . Our
model predicts the oscillation probability
in the range sensitive to the future experiments such as CHORUS and NOMAD.Comment: The title has been changed, to appear in Z. Phys.
Metastable supersymmetry breaking vacua from conformal dynamics
We study the scenario that conformal dynamics leads to metastable
supersymmetry breaking vacua. At a high energy scale, the superpotential is not
R-symmetric, and has a supersymmetric minimum. However, conformal dynamics
suppresses several operators along renormalization group flow toward the
infrared fixed point. Then we can find an approximately R-symmetric
superpotential, which has a metastable supersymmetry breaking vacuum, and the
supersymmetric vacuum moves far away from the metastable supersymmetry breaking
vacuum. We show a 4D simple model. Furthermore, we can construct 5D models with
the same behavior, because of the AdS/CFT dual.Comment: 3 pages; Talk given at SUSY0
Orbifold SUSY GUT from the Heterotic String
From the string partition function, we discuss the mass-shell and GSO
projection conditions valid for Kaluza-Klein (KK) as well as massless states in
the heterotic string theory compactified on a nonprime orbifold. Based on the
obtained conditions we construct a 4D string standard model, which is embedded
in a 6D SUSY GUT by including KK states above the compactification scale. We
discuss the stringy threshold corrections to gauge couplings, including the
Wilson line effects.Comment: To appear in the SUSY08 proceedings, 3 pages, LaTE
Indirect Signatures of Gravitino Dark Matter
Supersymmetric models provide very interesting scenarios to account for the
dark matter of the Universe. In this talk we discuss scenarios with gravitino
dark matter in R-parity breaking vacua, which not only reproduce very naturally
the observed dark matter relic density, but also lead to a thermal history of
the Universe consistent with the observed abundances of primordial elements and
the observed matter-antimatter asymmetry. In this class of scenarios the dark
matter gravitinos are no longer stable, but decay with very long lifetimes into
Standard Model particles, thus opening the possibility of their indirect
detection. We have computed the expected contribution from gravitino decay to
the primary cosmic rays and we have found that a gravitino with a mass of 150
GeV and a lifetime of 10^26 s could simultaneously explain the EGRET anomaly in
the extragalactic gamma-ray background and the HEAT excess in the positron
fraction.Comment: 6 pages, 4 figures. To appear in the proceedings of SUSY08, Seoul,
Kore
Modulated Inflation (@SUSY08)
We consider cosmological perturbations caused by modulated inflaton velocity.
During inflation, the inflaton motion is damped and the velocity is determined
by the parameters such as couplings or masses that may depend on light
fields(moduli). The number of e-foldings is different in different patches if
there are spatial fluctuations of such parameters. Based on this simple idea,
we consider ``modulated inflation'' in which the curvature perturbation is
generated by the fluctuation of the inflaton velocity. This talk is based on
our recent papers.Comment: talk given at susy0
An alternative to the standard model
We present an extension of the standard model to dark sector with an unbroken
local dark symmetry. Including various singlet portal interactions
provided by the standard model Higgs, right-handed neutrinos and kinetic
mixing, we show that the model can address most of phenomenological issues
(inflation, neutrino mass and mixing, baryon number asymmetry, dark matter,
direct/indirect dark matter searches, some scale scale puzzles of the standard
collisionless cold dark matter, vacuum stability of the standard model Higgs
potential, dark radiation) and be regarded as an alternative to the standard
model. The Higgs signal strength is equal to one as in the standard model for
unbroken case with a scalar dark matter, but it could be less than one
independent of decay channels if the dark matter is a dark sector fermion or if
is spontaneously broken, because of a mixing with a new neutral scalar
boson in the models.Comment: 10 pages, 3 figures, VII International Conference on Interconnections
between Particle Physics and Cosmology (PPC2013
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