$\mu \to e \gamma$ and $\mu \to 3e$ Processes with Polarized Muon and Supersymmetric Grand Unified Theories

Abstract

Lepton flavor violating processes $\mu \to e \gamma$ and $\mu \to 3e$ with polarized muons are studied in the supersymmetric grand unified theory (SUSY GUT). As a result of a detailed numerical calculation, it is shown that the P- and T-odd asymmetries defined with the help of the muon polarization and the ratio of two branching fractions make a good contrast between the SU(5) and SO(10) SUSY GUT. These observables are useful to extract differences of the two theories. In particular, the P-odd asymmetry of $\mu \to e \gamma$ varies 100%--100% in SO(10) whereas it is 100% in SU(5) and the T-odd asymmetry of $\mu \to 3e$ can reach 15% in SU(5) within the EDM constraints whereas it is small in SO(10).