353 research outputs found
Neutrino mixing in Seesaw model
We study the neutrino mixing matrix (the MNS matrix) in the seesaw model. By
assuming a large mass hierarchy for the heavy right-handed Majorana mass, we
show that, in the diagonal Majorana base, the MNS matrix is determined by a
unitary matrix, , which transforms the neutrino Yukawa matrix, ,
into a triangular form, . The mixing matrix of light leptons is
, where
% and diagonalize %the Yukawa matrices of charged leptons,
%, and neutrinos, ,
%respectively, and . Large mixing
may occur without fine tuning of the matrix elements of even if
the usual KM-like matrix is given by . This large mixing
naturally may satisfy the experimental lower bound of the mixing implied by the
atmospheric neutrino oscillation.Comment: 14 pages, 4 figures, PTPTe
Numerical study on the correlation between CP violation in neutrino oscillations and baryogenesis
We numerically study the correlation between CP violation in the neutrino
oscillations and baryogenesis in the seesaw model. In this study we get the
heavy Majorana neutrino masses and lepton number asymmetries from their decays
by fitting the data of neutrino oscillations and by working on some hypothesis
of the Dirac-Yukawa term for neutrinos.Comment: 3 pages, 2 figures, Latex, presented at KEKTC5(Nov. 2001), to be
published in Nucl. Phys. Proc. Supp
Depth Dependence of Radiation Hardening in 10 MeV 4He+-Ion Bombarded Molybdenum
開始ページ、終了ページ: 冊子体のページ付
Hardness Anisotropy in Molybdenum Single Crystals Bombarded with 50 MeV He Ions
開始ページ、終了ページ: 冊子体のページ付
B->rho pi decays, resonant and nonresonant contributions
We point out that a new contribution to B decays to three pions is relevant
in explaining recent data from the CLEO and BABAR collaborations, in particular
the results on quasi-two-body decays via a rho meson. We also discuss the
relevance of these contribution to the measurement of CP violations.Comment: 5 pages, 2 figures, few references and minor comments adde
Spin Fluctuations and the Magnetic Phase Diagram of ZrZn2
The magnetic properties of the weak itinerant ferromagnet ZrZn_2 are analyzed
using Landau theory based on a comparison of density functional calculations
and experimental data as a function of field and pressure. We find that the
magnetic properties are strongly affected by the nearby quantum critical point,
even at zero pressure; LDA calculations neglecting quantum critical spin
fluctuations overestimate the magnetization by a factor of approximately three.
Using renormalized Landau theory, we extract pressure dependence of the
fluctuation amplitude. It appears that a simple scaling based on the
fluctuation-dissipation theorem provides a good description of this pressure
dependence.Comment: 4 revtex page
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
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