Probing violation of CP & T invariance in the transitions of τ leptons

Abstract

The SM predicts zero value for {\bf CP} \& {\bf T} violation in the decays of $τ$ leptons -- except $τ^- \to νK_S [π^-/π^-π^0 ...]$. Our community could establish impact of New Dynamics (ND) in a {\bf CP} asymmetry in a semi-hadronic $τ$ transition and later in a second one. To be `practical', I suggest to our experimental colleagues to probe $τ^- \to ν\bar K^0 [π^-/π^-π^0/π^-η]$and $τ^- \to νK^-[π^0/π^+π^-/η]$. While I had mostly given comments about {\bf CP} violation in $τ$ transitions, some theorists have shown how ND models could produce {\bf CP} asymmetries; I will discuss these ones, although sometimes I am not a true theorist, but as a phenomenalist here. I can hardly `dream' that {\bf CP} asymmetry in $τ$ decays could connected with our huge asymmetry in `our' matter vs. anti-matter.