2,313 research outputs found
Unitarity Quadrangles of Four Neutrino Mixing
We present a classification of the unitarity quadrangles in the four-neutrino
mixing scheme. We find that there are totally thirty-six distinct topologies
among twelve different unitarity quadrangles. Concise relations are established
between the areas of those unitarity quadrangles and the rephasing invariants
of CP and violation.Comment: RevTex 10 pages. Minor changes made. Accepted for publication in
Phys. Rev.
Neutrino Masses, Lepton Flavor Mixing and Leptogenesis in the Minimal Seesaw Model
We present a review of neutrino phenomenology in the minimal seesaw model
(MSM), an economical and intriguing extension of the Standard Model with only
two heavy right-handed Majorana neutrinos. Given current neutrino oscillation
data, the MSM can predict the neutrino mass spectrum and constrain the
effective masses of the tritium beta decay and the neutrinoless double-beta
decay. We outline five distinct schemes to parameterize the neutrino
Yukawa-coupling matrix of the MSM. The lepton flavor mixing and baryogenesis
via leptogenesis are investigated in some detail by taking account of possible
texture zeros of the Dirac neutrino mass matrix. We derive an upper bound on
the CP-violating asymmetry in the decay of the lighter right-handed Majorana
neutrino. The effects of the renormalization-group evolution on the neutrino
mixing parameters are analyzed, and the correlation between the CP-violating
phenomena at low and high energies is highlighted. We show that the observed
matter-antimatter asymmetry of the Universe can naturally be interpreted
through the resonant leptogenesis mechanism at the TeV scale. The
lepton-flavor-violating rare decays, such as , are also
discussed in the supersymmetric extension of the MSM.Comment: 50 pages, 22 EPS figures, macro file ws-ijmpe.cls included, accepted
for publication in Int. J. Mod. Phys.
Calculable CP-violating Phases in the Minimal Seesaw Model of Leptogenesis and Neutrino Mixing
We show that all nontrivial CP-violating phases can be determined in terms of
three lepton flavor mixing angles and the ratio of to
in the minimal seesaw model in which the
Frampton-Glashow-Yanagida (FGY) ansatz is incorporated. This important point
allows us to make very specific predictions for the cosmological baryon number
asymmetry and CP violation in neutrino oscillations. A measurement of the
smallest neutrino mixing angle will sensitively test the FGY ansatz, in
particular in the case that three light neutrinos have a normal mass hierarchy.Comment: RevTex 13 pages (3 PS figures included). A new figure and references
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