2,242 research outputs found
S_4 Flavor Symmetry Embedded into SU(3) and Lepton Masses and Mixing
Based on an assumption that an S_4 flavor symmetry is embedded into SU(3), a
lepton mass matrix model is investigated. A Frogatt-Nielsen type model is
assumed, and the flavor structures of the masses and mixing are caused by VEVs
of SU(2)_L-singlet scalars \phi_u and \phi_d which are nonets (8+1) of the
SU(3) flavor symmetry, and which are broken into 2+3+3' and 1 of S_4. If we
require the invariance under the transformation (\phi^{(8)},\phi^{(1)}) \to
(-\phi^{(8)},+\phi^{(1)}) for the superpotential of the nonet field
\phi^{(8+1)}, the model leads to a beautiful relation for the charged lepton
masses. The observed tribimaximal neutrino mixing is understood by assuming two
SU(3) singlet right-handed neutrinos \nu_R^{(\pm)} and an SU(3) triplet scalar
\chi.Comment: 12 pages, no figure, to appear on JHE
A_4 Symmetry and Lepton Masses and Mixing
Stimulated by Ma's idea which explains the tribimaximal neutrino mixing by
assuming an A_4 flavor symmetry, a lepton mass matrix model is investigated. A
Frogatt-Nielsen type model is assumed, and the flavor structures of the masses
and mixing are caused by the VEVs of SU(2)_L-singlet scalars \phi_i^u and
\phi_i^d (i=1,2,3), which are assigned to {\bf 3} and ({\bf 1}, {\bf 1}',{\bf
1}'') of A_4, respectively.Comment: 13 pages including 1 table, errors in Sec.7 correcte
Universal Seesaw Mass Matrix Model with an S_3 Symmetry
Stimulated by the phenomenological success of the universal seesaw mass
matrix model, where the mass terms for quarks and leptons f_i (i=1,2,3) and
hypothetical super-heavy fermions F_i are given by \bar{f}_L m_L F_R +\bar{F}_L
m_R f_R + \bar{F}_L M_F F_R + h.c. and the form of M_F is democratic on the
bases on which m_L and m_R are diagonal, the following model is discussed: The
mass terms M_F are invariant under the permutation symmetry S_3, and the mass
terms m_L and m_R are generated by breaking the S_3 symmetry spontaneously. The
model leads to an interesting relation for the charged lepton masses.Comment: 8 pages + 1 table, latex, no figures, references adde
Evolution of the Yukawa coupling constants and seesaw operators in the universal seesaw model
The general features of the evolution of the Yukawa coupling constants and
seesaw operators in the universal seesaw model with det M_F=0 are investigated.
Especially, it is checked whether the model causes bursts of Yukawa coupling
constants, because in the model not only the magnitude of the Yukawa coupling
constant (Y_L^u)_{33} in the up-quark sector but also that of (Y_L^d)_{33} in
the down-quark sector is of the order of one, i.e., (Y_L^u)_{33} \sim
(Y_L^d)_{33} \sim 1. The requirement that the model should be calculable
perturbatively puts some constraints on the values of the intermediate mass
scales and tan\beta (in the SUSY model).Comment: 21 pages, RevTex, 10 figure
Tribimaximal Neutrino Mixing and a Relation Between Neutrino- and Charged Lepton-Mass Spectra
Brannen has recently pointed out that the observed charged lepton masses
satisfy the relation m_e +m_\mu +m_\tau = {2/3}
(\sqrt{m_e}+\sqrt{m_\mu}+\sqrt{m_\tau})^2, while the observed neutrino masses
satisfy the relation m_{\nu 1} +m_{\nu 2} +m_{\nu 3} = {2/3} (-\sqrt{m_{\nu
1}}+\sqrt{m_{\nu 2}}+\sqrt{m_{\nu 3}})^2. It is discussed what neutrino Yukawa
interaction form is favorable if we take the fact pointed out by Brannen
seriously.Comment: 13 pages, presentation modifie
The effect of shear and bulk viscosities on elliptic flow
In this work, we examine the effect of shear and bulk viscosities on elliptic
flow by taking a realistic parameterization of the shear and bulk viscous
coefficients, and , and their respective relaxation times,
and . We argue that the behaviors close to ideal fluid
observed at RHIC energies may be related to non-trivial temperature dependence
of these transport coefficients.Comment: 6 pages, 4 figures, to appear in the proceedings of Strange Quark
Matter 2009 (SQM09
NNI-Form Quark Mass Matrix Expressed by the Observable Quantities
It is pointed out that the phase convention of the CKM matrix V affects
texture analysis of the quark mass matrices (M_u, M_d) when we try to describe
(M_u, M_d) by the observable quantities (quark masses and CKM matrix
parameters) only. This is demonstrated for a case of the non-Hermitian
Fritzsch-type mass matrix (tilde{M}_u, tilde{M}_d), which is a general
expression of quark mass matrix (M_u, M_d) and is described by twelve
parameters. We find that we can always choose a phase convention of V which
yields tilde{M}_{u32} = 0, so that the remaining ten parameters in (tilde{M}_u,
tilde{M}_d) can completely be expressed by the ten observable quantities.Comment: 11 pages (LaTeX); Title was change
Contractor point of view for system development and test program
Industry's practice of testing space qualified hardware is examined. An overview of the Global Positioning System (GPS) Test Program is discussed from the component level to the sub-system compatibility tests with the space vehicle and finally to the launch site tests, all related to the Rubidium clock
S_3 Symmetry and Neutrino Masses and Mixings
Based on a universal seesaw mass matrix model with three scalars \phi_i, and
by assuming an S_3 flavor symmetry for the Yukawa interactions, the lepton
masses and mixings are investigated systematically. In order to understand the
observed neutrino mixing, the charged leptons (e, \mu, \tau) are regarded as
the 3 elements (e_1, e_2, e_3) of S_3, while the neutrino mass-eigenstates are
regarded as the irreducible representation (\nu_\eta, \nu_\sigma, \nu_\pi) of
S_3, where (\nu_\pi, \nu_\eta) and \nu_\sigma are a doublet and a singlet,
respectively, which are composed of the 3 elements (\nu_1, \nu_2, \nu_3) of
S_3.Comment: 16 pages, no figure, version to appear in EPJ-
Microscopic Derivation of Causal Diffusion Equation using Projection Operator Method
We derive a coarse-grained equation of motion of a number density by applying
the projection operator method to a non-relativistic model. The derived
equation is an integrodifferential equation and contains the memory effect. The
equation is consistent with causality and the sum rule associated with the
number conservation in the low momentum limit, in contrast to usual acausal
diffusion equations given by using the Fick's law. After employing the Markov
approximation, we find that the equation has the similar form to the causal
diffusion equation. Our result suggests that current-current correlations are
not necessarily adequate as the definition of diffusion constants.Comment: 10 pages, 1 figure, Final version published in Phys. Rev.
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