Tying inCPand flavor violations with fermion masses and neutrino oscillations

Abstract

In this paper we explore the possibility that (a) fermion masses, (b) neutrino oscillations, (c) CP non-conservation and (d) flavor violations get intimately linked to each other within supersymmetric grand unification based on SO(10) or an effective G(224) = SU(2)_L\times SU(2)_R\times SU(4)^c symmetry. We extend the framework proposed previously by Babu, Pati and Wilczek (BPW) which successfully described fermion masses and neutrino oscillations, to include CP violation. Assuming flavor universal SUSY breaking parameters at M^* >~ M_{GUT}, and that CP violation arises through phases in the fermion mass matrices, we show how the presence of GUT threshold induces new and calculable CP and flavor violations. Including SM and SUSY contributions, we find that the BPW framework can correctly account for the observed flavor and/or CP violations in \Delta m_K, \Delta m_{B_d}, S(B_d-> J/\psi K_S) and \epsilon_K. While SUSY-contribution is small (<~ few%) for the first three quantities, that to \epsilon_K is sizable (~ 20-25%) and negative (as desired) compared to that of the SM. The model predicts S(B_d-> \phi K_S) to be in the range +(0.65-0.73), close to the SM prediction. The model yields Re(\epsilon'/\epsilon)_{SUSY}\approx +(4-14)\times 10^{-4}; the relevance of this contribution can be assessed only when the associated matrix elements are known reliably. The model also predicts that the electric dipole moments of the neutron and the electron should be discovered with improvements in current limits by factors of 10 to 100.