Non-standard interactions in ${\tau }^{-}\to ({\pi }^{-}\eta ,{\pi }^{-}{\pi }^0){\nu }_{\tau }$ decays

Abstract

Originally thought as clean processes to study the hadronization of the weak currents, semileptonic tau lepton decays can be useful to set constraints on non-standard (NS) weak interactions. In this talk we summarize our recent studies on the effects of NS interactions in ${\tau }^{-}\to ({\pi }^{-}{\pi }^0,{\pi }^{-}\eta ){\nu }_{\tau }$ decays. We find that experimental data on these decays provide strong constraints on NS scalar and tensor interactions, respectively. Further improved measurements at Belle II and a better knowledge of necessary tensor and scalar form factors will allow to set limits on these NS interactions that are similar or better to contraints obtained from other low-energy processes.

Comments: 11 pages. Procs. 15th Int. Workshop on Tau Lepton Physics, Amsterdam, 24-28 september 2018