Direct CP violation in $$\tau ^\pm \rightarrow K^\pm \rho ^0 (\omega )\nu _\tau \rightarrow K^\pm \pi ^+\pi ^-\nu _\tau $$ τ ± → K ± ρ 0 ( ω ) ν τ → K ± π + π - ν τ

Abstract

We study the direct CP violation in the $\tau^\pm\rightarrow K^\pm \rho^0 (\omega)\nu_\tau \rightarrow K^\pm \pi^+\pi^-\nu_\tau$ decay process in the Standard Model. An interesting mechanism involving the charge symmetry violating mixing between $\rho^0$ and $\omega$ is applied to enlarge the CP asymmetry. With this mechanism, the maximum differential and localized integrated CP asymmetries can reach $-(5.6^{+2.9}_{-1.7})\times10^{-12}$ and $6.3^{+2.4}_{-3.3}\times 10^{-11}$, respectively, which still leave plenty room for CP-violating New Physics to be discovered through this process.