819 research outputs found
Inflation in a modified radiative seesaw model
The existence of the inflationary era in the early Universe seems to be
strongly supported by recent CMB observations. However, only a few realistic
inflation scenarios which have close relation to particle physics seem to have
been known unfortunately. The radiative neutrino mass model with inert doublet
dark matter is a promising model for the present experimental issues which
cannot be explained within the standard model. In order to make the model
include inflation, we extend it by a complex scalar field with a specific
potential. This scalar could be closely related to the neutrino mass generation
at a TeV scale as well as inflation. We show that the inflation favored by the
CMB observations could be realized even if inflaton takes sub-Planck values
during inflation.Comment: 20 pages, 3 figure
Effect on the electron EDM due to abelian gauginos in SUSY extra U(1) models
The electric dipole moment of an electron (EDME) is investigated in the
supersymmetric extra U(1) models. Neutralino sector is generally extended in
these models and then the neutralino contribution will be important for the
analysis of the EDME. Kinetic term mixings of abelian gauginos are taken into
account in our analysis. Numerical results for the extra U(1) models show that
the EDME can be affected by the extra U(1) in a certain range of soft
supersymmetry breaking parameters even if the extra U(1) gauge boson is heavy.
The EDME may be a clue to find an extended gauge structure in the
supersymmetric models.Comment: 16 pages, latex, 3 figure
Gaugino CP phases and EDMs in the extended gauge mediation SUSY breaking
We study phenomenological aspects of the soft supersymmetry breaking
parameters in a model with the extended gauge mediation supersymmetry breaking.
In this model gaugino masses can be non-universal and as its result physical
CP-phases remain in the gaugino sector even after the R-transformation. These
phases contribute to the electric dipole moment (EDM) of an electron and a
neutron. We show that their experimental bounds can be satisfied even for the
situation such that there exist the order one CP-phases and the masses of
superpartners are of the order of 100 GeV.Comment: LaTeX, 26 pages, 6 figure
Mass bound of the lightest neutral Higgs scalar in the extra U(1) models
The upper mass bound of the lightest neutral Higgs scalar is studied in the
problem solvable extra U(1) models by using the analysis of the
renormalization group equations. In order to restrict the parameter space we
take account of a condition of the radiative symmetry breaking and some
phenomenological constraints. We compare the bound obtained based on this
restricted parameter space with the one of the next to the minimal
supersymmetric standard model (NMSSM). Features of the scalar potential and
renormalization group equations of the Yukawa couplings among Higgs chiral
supermultiplets are rather different between them. They can reflect in this
bound.Comment: 22 pages, latex, 11 eps-figure
Leptogenesis and dark matter unified in a non-SUSY model for neutrino masses
We propose a unified explanation for the origin of dark matter and baryon
number asymmetry on the basis of a non-supersymmetric model for neutrino
masses. Neutrino masses are generated in two distinct ways, that is, a
tree-level seesaw mechanism with a single right-handed neutrino, and one-loop
radiative effects by a new additional doublet scalar. A spontaneously broken
U(1) brings a symmetry which restricts couplings of this new
scalar and controls the neutrino masses. It also guarantees the stability of a
CDM candidate. We examine two possible candidate for the CDM. We also show that
the decay of a heavy right-handed neutrino related to the seesaw mechanism can
generate baryon number asymmetry through leptogenesis.Comment: 21 pages, 3 figures, extended version for publication, references
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Dark world and baryon asymmetry from a common source
We study generation of baryon number asymmetry and both abundance of dark
matter and dark energy on the basis of global symmetry and its associating flat
directions in a supersymmetric model. We assume the existence of a model
independent axion which is generally expected in the effective theory of
superstring. If we consider a combined field of the model independent axion and
a pseudo Nambu-Goldstone boson coming from spontaneous breaking of the global
symmetry, its potential can be sufficiently flat and then it may present a
candidate of the dark energy as a quintessential axion. Both the baryon
asymmetry and the dark matter are supposed to be produced nonthermally as the
asymmetry of another global charge through the Affleck-Dine mechanism along the
relevant flat direction. Its decay to the observable and hidden sectors
explains the baryon number asymmetry and the dark matter abundance,
respectively.Comment: 28 page
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