The semileptonic decaysB→Mτν as a probe of hadron dynamics

Abstract

We show how data on\(\bar B \to M\tau \bar v\) can be used to probe models for the hadronic form-factors which describe the\(\bar B \to M\) transition, whereM isD,D* etc. Extra form-factors contribute to\(\bar B \to M\tau \bar v\), as compared to\(\bar B \to Me\bar v\), and these may be studied by observing the polarisation of the outgoing τ. Model predictions for the decay rate and the τ polarisation are presented.