Addendum to the Test of CP Violation in Tau Decay

Abstract

We discuss the test of CP and CPT violation in $\tau$ decay without using the polarized electron beam by comparing partial fractions of $\tau^-$ and $\tau^+$ decay into channels with strong final state interactions. For example, $\Gamma(\tau^-\rarrow \pi^-+\pi^0+\nu) \ne \Gamma(\tau^+\rarrow \pi^++\pi^0+\nu)$ signifies violation of CP. The optimum energy to investigatge CP violation in $\tau$ decay is discussed. We conclude that this energy is a few MeV below $\psi(2s)$ in order to avoid the charm contribution and over abundance of hadrons at the $\psi(2s)$ peak.