A new measurement of electron transverse polarization in polarized nuclear β-decay

Abstract

The Mott polarimetry for T -Violation (MTV) experiment tests time-reversal symmetry in polarized nuclear β decay by measuring an electron's transverse polarization as a form of angular asymmetry in Mott scattering using a thin metal foil. A Mott scattering analyzer system developed using a tracking detector to measure scattering angles offers better event selectivity than conventional counter experiments. In this paper, we describe a pilot experiment conducted at KEK-TRIAC using a prototype system with a polarized 8 Li beam. The experiment confirmed the sound performance of our Mott analyzer system to measure T -violating triple correlation (R correlation), and therefore recommends its use in higher-precision experiments at the TRIUMF-ISAC.