Recent Results on $τ$ Decays

Abstract

We present herein new results from Belle on the $τ^- \rightarrow π^- ν_{\rm τ} \ell^+ \ell^- $ branching fraction and from BABAR on the $τ^- \rightarrow K^- (0,1,2,3) π^0 ν_{\rm τ}$, $τ^- \rightarrow π^- (3,4) π^0 ν_{\rm τ}$ and $τ^- \rightarrow K^- K^0_{\rm S} ν_{\rm τ}$ branching fractions. From the $K^- K^0_{\rm S}$ mass spectrum we determine the spectral function. The improved branching fraction measurements of the $τ^- \rightarrow K^- (0,1,2,3) π^0 ν_{\rm τ}$ decays are used to determine $|V_{\rm us}|$ from $τ^- \rightarrow X_{\rm s}^- ν_{\rm τ}$ inclusive decays.

8 pages, 11 figures, plenary talk at the Flavor Physics and CP Violation conference, FPCP2019 in Victoria, Canada