Lepton flavor violation within a realistic SO(10)/G(224) framework

Lepton flavor violation (LFV) is studied within a realistic unified framework, based on supersymmetric SO(10) or an effective G(224) = SU(2)(L) x SU(2) (R) x SU(4)(c) symmetry, that successfully describes (i) fermion masses and mixings, (ii) neutrino oscillations, as well as (iii) CP violation. LFV emerges as an important prediction of this framework, bringing no new parameters, barring the few SUSY parameters, which are assumed to be flavor-universal at M* greater than or similar to M-GUT. We study LFV (i.e., A -> e gamma, tau -> mu gamma, tau -> e gamma and mu N -> eN) within this framework by including contributions both from the presence of the right-handed neutrinos as well as those arising from renormalization group running in the post-GUT regime (M* -> M-GUT). Typically the latter, though commonly omitted in the literature, is found to dominate. Our predicted rates for mu -> e gamma show that while some choices of (m(0), m(1/2)) are clearly excluded by the current empirical limit, this decay should be seen with an improvement of the current sensitivity by a factor of 10-100, even if sleptons are moderately heavy (; 800 GeV, say). For the same reason, mu-e conversion (mu N -> eN) should show in the planned MECO experiment. Implications of WMAP and (g - 2)(mu)-measurements are noted, as also the significance of the measurement of parity-odd asymmetry in the decay of polarized mu(+) into e(+) gamma. (c) 2005 Elsevier B.V. All rights reserved.