Addendum to the Test of CP Violation in Tau Decay

Abstract

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