Search for Time-Reversal Violation in the Beta Decay ofLi8

Abstract

The transverse polarization in a plane perpendicular to the nuclear spin has been measured for electrons emitted in the beta decay of polarized ${\mathrm{Li}}^8$ nuclei. The amplitude R of the time-reversal-violating triple correlation between nuclear spin, momentum, and spin of the electron has been determined. Our result, R=0.004±0.014, is consistent with time-reversal invariance and provides a first direct limit on the imaginary charged weak tensor interaction -0.03CT+${\mathrm{C}}_{\mathrm{T}}^{\prime }$)/${\mathrm{C}}_{\mathrm{A}}$<0.05.