Seesaw Enhancement of Bi-large Mixing in Two-Zero Textures

The seesaw enhancement of the bi-large mixings are discussed for the two-zero textures of the neutrino mass matrix. There are no large mixings in both Dirac neutrino mass matrix $m_D$ and right-handed Majorana neutrino mass matrix $M_R$, however, the bi-large mixing is realized via the seesaw mechanism. We present twelve sets of $m_D$ and $M_R$ for the seesaw enhancement and discuss the related phenomena, the $\mu\to e+\gamma$ process and the leptogenesis. The decay rate of $\mu\to e+\gamma$ is enough suppressed due to zeros in the Dirac neutrino mass matrix. Six $m_D$ lead to the lepton asymmetry, which can explain the baryon number in the universe. Other six $m_D$ are the real matrices, which give no CP asymmetry. Modified Dirac neutrino mass matrices are also discussed.Comment: latex file, 16 page

Can symmetric texture reproduce unitarity triangle and mb/mτm_b/m_\tau ?

We study the SUSY SO(10) GUT with the symmetric two-zero textures of quark/lepton mass matrix which realize the Georgei-Jarlskog relations in down-type quark and charged lepton masses. We show that the important constraints to such framework come from the bottom-tau unification and the observed value of $\sin2\beta$, one of the angles in the CKM unitarity triangle. We investigate the symmetric two-zero textures assumed at the GUT scale by solving the MSSM renormalization group equations with right-handed neutrino threshold effects. As a result, the value of $\tan\tilde{\beta}$ is constrained to be large enough and the representation of Higgs field which couples to the third generation of left- and right-handed neutrinos is restricted by the bottom-tau unification condition. The textures with vanishing 1-2 (and 2-1) element for up-type quarks and vanishing 1-3 (and 3-1) element for down-type quarks are favored by the observation of $\sin2\beta$.Comment: 11 pages, 5 figure

Symmetric Mass Matrix with Two Zeros in SUSY SO(10) GUT, Lepton Flavor Violations and Leptogenesis

We study the symmetric 2-zero texture of the neutrino mass matrix, which is obtained from the symmetric Dirac neutrino mass matrix with 2-zeros and right-handed Majorana neutrino mass matrix with the general form via the see-saw mechanism, for the SUSY SO(10) GUT model including the Pati-Salam symmetry. We show that the only one texture in our model, having degenerate mass spectrum for the 1st and 2nd generation of right-handed Majorana neutrino, can simultaneously explain the current neutrino experimental data, lepton flavor violating processes and baryon asymmetry of the Universe. Within such a framework, the predicted values of the light and heavy Majorana neutrino masses, together with $|U_{e3}|$, $J_{{\rm CP}}$ and $||$, are almost uniquely determined.Comment: 36 pages, latex, 17 figures. Preprint version contains "low resolution" figures to reduce the size of overall postscript file. Please contact authors to obtain the high resolution version. Some references added. Section 1 and subsection 2.1 are revised, conclusions are not changed, typos correcte

Can Symmetric Texture reproduce Neutrino Bi-large Mixing?

We study the symmetric texture of geometric form with 2-zeros to see if it is consistent with the presently-known neutrino masses and mixings. In the neutrino mass matrix elements we obtain numerically the allowed region of the parameters including CP violating phases, which can reproduce the present neutrino experiment data. The result of this analysis dictates the narrow region for the GUT model including Pati-Salam symmetry with texture zeros to be consistent with the experimental data. The $|U_{e3}|$ and $J_{CP}$ are also predicted in such models.Comment: 11 pages, 4 figure

Bifurcations in Globally Coupled Chaotic Maps

We propose a new method to investigate collective behavior in a network of globally coupled chaotic elements generated by a tent map. In the limit of large system size, the dynamics is described with the nonlinear Frobenius-Perron equation. This equation can be transformed into a simple form by making use of the piecewise linear nature of the individual map. Our method is applied successfully to the analyses of stability of collective stationary states and their bifurcations.Comment: 12 pages, revtex, 10 figure

Flavor Symmetry and Vacuum Aligned Mass Textures

The mass matrix forms of quarks and leptons are discussed in theory with permutation flavor symmetry. The structure of scalar potential is analyzed in case that electroweak doublet Higgs fields have non-trivial flavor symmetry charges. We find that realistic forms of mass matrices are obtained dynamically in the vacuum of the theory, where some of Higgs bosons have vanishing expectation values which lead to vanishing elements in quark and lepton mass matrices. Mass textures are realized in the true vacuum and their positions are controlled by flavor symmetry. An interesting point is that, due to the flavor group structure, the up and down quark mass matrices are automatically made different in the vacuum, which lead to non-vanishing generation mixing. It is also discussed that flavor symmetry is needed to be broken in order not to have too light scalars. The lower bounds of Higgs masses are derived from the experimental data of flavor-changing rare processes such as the neutral K meson mixing.Comment: 30pages, 2figures, some discussions are added, one reference is adde