BETA-GAMMA-GAMMA CORRELATION IN MN-56 . A TEST OF TIME-REVERSAL INVARIANCE

A test of time-reversal invariance was performed by measuring the imaginary part |δ|sinη of the mixing ratio δ=|δ|eiη between E2 and M1 reduced matrix elements through the observation of two β-γ-γ cascades in Mn56. The imaginary part was found to be (-8.1±4.8)×10-3 for the 1.81-MeV transition, and (-7.1±3.7)×10-3 for the 2.12-MeV transition. In order to eliminate instrumental asymmetries, the difference between the two values was taken, Δ(|δ|sinη)=(1±6)×10-3. With an average mixing ratio for the two transitions, |δ|=0.24, the difference in phases is ΔsinηΔη(0.4±2.6)×10-2, giving no evidence for time-reversal violation. © 1969 The American Physical Society.