Neutrino oscillation, SUSY GUT and B decay

Effects of supersymmetric particles on flavor changing neutral current and lepton flavor violating processes are studied in the supersymmetric SU(5) grand unified theory with right-handed neutrino supermultiplets. Using input parameters motivated by neutrino oscillation, it is shown that the time-dependent CP asymmetry of radiative B decay can be as large as 30% when the $\tau \to \mu \gamma$ branching ratio becomes close to the present experimental upper bound. We also show that the $B_s$--$\bar{B}_s$ mixing can be significantly different from the presently allowed range in the standard model.