6,528 research outputs found
Axion and Right-handed Neutrino in the Minimal SUSY SO(10) Model
The connection between the axion and right-handed neutrinos is explored in
the framework of the minimal SUSY SO(10) model. The former is related to the
Peccei-Quinn (PQ) solution to the strong CP problem and the latter is to the
light Majorana neutrinos through the see-saw mechanism. In this model, a
relative phase between and multiplets of becomes a physical degree of freedom identified with the
axion. Then, the PQ symmetry breaking scale () and the
symmetry breaking scale () coincide through the VEV of . The scalar partner of the lightest right-handed neutrino is
regarded as the inflaton, which gives a consistent density fluctuation for the
CMB.Comment: 8 pages, no figure; the version to appear in JHE
Neutrino Magnetic Moments and Minimal Supersymmetric SO(10) Model
We examine supersymmetric contributions to transition magnetic moments of
Majorana neutrinos. We first give the general formula for it. In concrete
evaluations, informations of neutrino mass matrix elements including CP phases
are necessary. Using unambiguously determined neutrino mass matrices in
recently proposed minimal supersymmetric SO(10) model, the transition magnetic
moments are calculated. The resultant neutrino magnetic moments are found to be
roughly an order of magnitude larger than those calculated in the standard
model extended to incorporate the see-saw mechanism.Comment: 8 pages, 4 figures, the version to be published in International
Journal of Modern Physics
General Formulation for Proton Decay Rate in Minimal Supersymmetric SO(10) GUT
We make an explicit formulation for the proton decay rate in the minimal
renormalizable supersymmetric (SUSY) SO(10) model. In this model, the Higgs
fields consist of and SO(10) representations in
the Yukawa interactions with matter and of , , , and representations in the Higgs potential. We present all
the mass matrices for the Higgs fields contained in this minimal SUSY SO(10)
model. Finally, we discuss the threshold effects of these Higgs fields on the
gauge coupling unification.Comment: 32 pages, typos are corrected, a few references and comments to the
papers arXiv:hep-ph/0204097 and arXiv:hep-ph/0402122 are adde
Impurity Effects on Quantum Depinning of Commensurate Charge Density Waves
We investigate quantum depinning of the one-dimensional (1D) commensurate
charge-density wave (CDW) in the presence of one impurity theoretically.
Quantum tunneling rate below but close to the threshold field is calculated at
absolute zero temperature by use of the phase Hamiltonian within the WKB
approximation. We show that the impurity can induce localized fluctuation and
enhance the quantum depinning. The electric field dependence of the tunneling
rate in the presence of the impurity is different from that in its absence.Comment: 14 pages with 13 figures. Submitted to J. Phys. Soc. Jp
Non-thermal Leptogenesis and a Prediction of Inflaton Mass in a Supersymmetric SO(10) Model
The gravitino problem gives a severe constraint on the thermal leptogenesis
scenario. This problem leads us to consider some alternatives to it if we try
to keep the gravitino mass around the weak scale GeV. We
consider, in this paper, the non-thermal leptogenesis scenario in the framework
of a minimal supersymmetric SO(10) model. Even if we start with the same
minimal SO(10) model, we have different predictions for low-energy
phenomenologies dependent on the types of seesaw mechanism. This is the case
for leptogenesis: it is shown that the type-I see-saw model gives a consistent
scenario for the non-thermal leptogenesis but not for type-II. The predicted
inflaton mass needed to produce the observed baryon asymmetry of the universe
is found to be GeV for the reheating temperature
GeV.Comment: 9 pages, 2 figures; the version to appear in JCA
Anomalous Hall effect and weak localization corrections in a ferromagnet
In this paper, we report results on the anomalous Hall effect. First, we
summarize analytical calculations based on the Kubo formalism : explicit
expressions for both skew-scattering and side-jump are derived and
weak-localization corrections are discussed. Next, we present numerical
calculations of the anomalous Hall resistivity based on the Dirac equation.
Qualitative agreement with experiments is obtained.Comment: Proceeding JEMS'0
Effect of Local Inhomogeneity on Nucleation; Case of Charge Density Wave Depinning
The spatial inhomogeneities are expected to affect nucleation process in an
essential way. These effects are studied theoretically by considering the case
of the depinning of the charge density wave as a typical example. The threshold
field of the depinning of the one-dimensional commensurate charge density wave
with one impurity has been examined classically based on the phase Hamiltonian
at absolute zero. It is found that the threshold field is lowered by a finite
amount compared to that in the absence of an impurity.Comment: pages 12, LaTeX, 9 figures, uses jpsj.sty, submitted to J. Phys. Soc.
Jp
Theoretical Study of Friction: A Case of One-Dimensional Clean Surfaces
A new method has been proposed to evaluate the frictional force in the
stationary state. This method is applied to the 1-dimensional model of clean
surfaces. The kinetic frictional force is seen to depend on velocity in
general, but the dependence becomes weaker as the maximum static frictional
force increases and in the limiting case the kinetic friction gets only weakly
dependent on velocity as described by one of the laws of friction. It is also
shown that there is a phase transition between state with vanishing maximum
static frictional force and that with finite one. The role of randomness at the
interface and the relation to the impurity pinning of the sliding
Charge-Density-Wave are discussed. to appear in Phys.Rev.B. abstract only. Full
text is available upon request. E-mail: [email protected]: 2 pages, Plain TEX, OUCMT-94-
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