297 research outputs found
Admixture of quasi-Dirac and Majorana neutrinos with tri-bimaximal mixing
We propose a realization of the so-called bimodal/schizophrenic model
proposed recently. We assume S4, the permutation group of four objects as
flavor symmetry giving tri-bimaximal lepton mixing at leading order. In these
models the second massive neutrino state is assumed quasi-Dirac and the
remaining neutrinos are Majorana states. In the case of inverse mass hierarchy,
the lower bound on the neutrinoless double beta decay parameter m_ee is about
two times that of the usual lower bound, within the range of sensitivity of the
next generation of experiments.Comment: 8 pages, minor changes to match version accepted in PL
パーティクル・ボードに関する研究 : (第6報)含脂率およびパーティクル・ディメンションが低比重ボードの材質におよぼす影響について
この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました
Non-Abelian Discrete Flavor Symmetries on Orbifolds
We study non-Abelian flavor symmetries on orbifolds, and .
Our extra dimensional models realize , , and
including and . In addition, one can also realize
their subgroups such as , , etc. The flavor symmetry can be
realized on both and orbifolds.Comment: 16 page
Neutrino masses and mixing from S4 flavor twisting
We discuss a neutrino mass model based on the S4 discrete symmetry where the
symmetry breaking is triggered by the boundary conditions of the bulk
right-handed neutrino in the fifth spacial dimension. While the symmetry
restricts bare mass parameters to flavor-diagonal forms, the viable mixing
angles emerge from the wave functions of the Kaluza-Klein modes which carry
symmetry breaking effect. The magnitudes of the lepton mixing angles,
especially the reactor angle is related to the neutrino mass patterns and the
model will be tested in future neutrino experiments, e.g., an early (late)
discovery of the reactor angle favors the normal (inverted) hierarchy. The size
of extra dimension has a connection to the possible mass spectrum; a small
(large) volume corresponds to the normal (inverted) mass hierarchy.Comment: 22 pages, 3 figures; added references for section
Towards Minimal S4 Lepton Flavor Model
We study lepton flavor models with the flavor symmetry. We construct
simple models with smaller numbers of flavon fields and free parameters, such
that we have predictions among lepton masses and mixing angles. The model with
a triplet flavon is not realistic, but we can construct realistic models
with two triplet flavons, or one triplet and one doublet flavons.Comment: 18 pages, 4 figures, references are adde
Stationary structures in two-dimensional continuous Heisenberg ferromagnetic spin system
Stationary structures in a classical isotropic two-dimensional continuous
Heisenberg ferromagnetic spin system are studied in the framework of the
(2+1)-dimensional Landau-Lifshitz model. It is established that in the case of
\vec S (\vec r, t)= \vec S (\vec r - \vec v t) the Landau-Lifshitz equation is
closely related to the Ablowitz-Ladik hierarchy. This relation is used to
obtain soliton structures, which are shown to be caused by joint action of
nonlinearity and spatial dispersion, contrary to the well-known one-dimensional
solitons which exist due to competition of nonlinearity and temporal
dispersion. We also present elliptical quasiperiodic stationary solutions of
the stationary (2+1)-dimensional Landau-Lifshitz equation.Comment: Archive version is already official Published by JNMP at
http://www.sm.luth.se/math/JNMP
Quark-lepton mass relation and CKM mixing in an A(4) extension of the minimal supersymmetric standard model
An interesting mass relation between down-type quarks and charged leptons has been recently predicted within a supersymmetric SU(3)(c) circle times SU(2)(L) circle times U(1)(Y) model based on the A(4) flavor symmetry. Here we propose a simple extension which provides an adequate full description of the quark sector. By adding a pair of vectorlike up quarks, we show how the CKM entries V-ub, V-cb, V-td and V-ts arise from deviations of the unitarity. We perform an analysis including the most relevant observables in the quark sector, such as oscillations and rare decays of kaons, B-d and B-s mesons. In the lepton sector, the model predicts an inverted hierarchy for the neutrino masses, leading to a potentially observable rate of neutrinoless double beta decay
Unique Continuation for Schr\"odinger Evolutions, with applications to profiles of concentration and traveling waves
We prove unique continuation properties for solutions of the evolution
Schr\"odinger equation with time dependent potentials. As an application of our
method we also obtain results concerning the possible concentration profiles of
blow up solutions and the possible profiles of the traveling waves solutions of
semi-linear Schr\"odinger equations.Comment: 23 page
Abelian Chern-Simons Vortices and Holomorphic Burgers' Hierarchy
The Abelian Chern-Simons Gauge Field Theory in 2+1 dimensions and its
relation with holomorphic Burgers' Hierarchy is considered. It is shown that
the relation between complex potential and the complex gauge field as in
incompressible and irrotational hydrodynamics, has meaning of the analytic
Cole-Hopf transformation, linearizing the Burgers Hierarchy in terms of the
holomorphic Schr\"odinger Hierarchy. Then the motion of planar vortices in
Chern-Simons theory, appearing as pole singularities of the gauge field,
corresponds to motion of zeroes of the hierarchy. Using boost transformations
of the complex Galilean group of the hierarchy, a rich set of exact solutions,
describing integrable dynamics of planar vortices and vortex lattices in terms
of the generalized Kampe de Feriet and Hermite polynomials is constructed. The
results are applied to the holomorphic reduction of the Ishimori model and the
corresponding hierarchy, describing dynamics of magnetic vortices and
corresponding lattices in terms of complexified Calogero-Moser models.
Corrections on two vortex dynamics from the Moyal space-time non-commutativity
in terms of Airy functions are found.Comment: 15 pages, talk presented in Workshop `Nonlinear Physics IV: Theory
and Experiment`, 22-30 June 2006, Gallipoli, Ital
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