Implications of the Renormalization Group Equations in Three-Neutrino Models with Two-fold Degeneracy

We obtain a {\it complete set} of one-loop RGE's for a set of combinations of neutrino parameters for the case of two-fold degenerate hierarchical three-neutrino models. The requirement of consistency of exact solutions to these RGE's with the two-fold degeneracy yields conditions which have previously been obtained perturbatively/numerically. These conditions, in the limit $|U_{e\nu_{3}}|=0$, are shown to lead to a strong cancellation in the matrix element of neutrinoless double beta decay.Comment: 10 pages; RevTeX; 3 eps figures; minor typos corrected; one reference adde

Relating Leptogenesis to Low Energy CP Violation

In the minimal left-right symmetric model with spontaneous CP violation, there are only two intrinsic CP violating phases to account for all CP violation in both the quark and lepton sectors. In addition, the left-and right-handed Majorana mass terms for the neutrinos are proportional to each other due to the parity in the model. This is thus a very constrained framework, making the existence of correlations among the CP violation in leptogenesis, neutrino oscillation and neutrinoless double beta decay possible.Comment: 4 pages; to appear in Proceedings of SUSY06, the 14th International Conference on Supersymmetry and the Unification of Fundamental Interactions, UC Irvine, California, 12-17 June 200

Lepton Flavor Violating Decays, Soft Leptogenesis and SUSY SO(10)

We investigate lepton flavor violating decays in a SUSY SO(10) model with symmetric textures recently constructed by us. Unlike the models with lop-sided textures which give rise to a large decay rate for mu -> e gamma, the decay rate we get is much suppressed and yet it is large enough to be accessible to the next generation of experiments. We have also investigated the possibility of baryogenesis resulting from soft leptogenesis. We find that with the soft SUSY masses assuming their natural values, B^\prime \equiv \sqrt{BM_{1}} ~ 1.4 TeV and Im(A) ~ 1 TeV, the observed baryon asymmetry in the Universe can be accommodated in our model. We have also updated the predictions of our model for the masses, mixing angles and CP violating measures in both charged fermion and neutrino sectors, using the most up-to-date experimental data as input.Comment: RevTeX, 22 pages, 9 figures; v2: references added, version to appear in Phys. Rev.