# The 8th International Workshop on the CKM Unitarity Triangle

8-12 September 2014
Vienna University of Technology
Europe/Vienna timezone

## NP scenarios in b-->c(u) l nu decays

10 Sep 2014, 12:35
20m
EI 10 lecture hall (Vienna University of Technology)

### Speaker

Fulvia De Fazio (INFN - Sezione di Bari)

### Description

The BaBar measurements of the ratios ${\cal R}(D^{(*)})=\frac{{\cal B}(B \to D^{(*)} \tau {\bar \nu}_\tau)}{{\cal B}(B \to D^{(*)} \mu {\bar \nu}_\mu)}$ deviate from the standard model expectation, while new results on the purely leptonic $B \to \tau {\bar \nu}_\tau$ mode show a better consistency with the standard model, within the uncertainties. In a new physics scenario, one possibility to accomodate these two experimental facts consists in considering an additional tensor operator in the effective weak hamiltonian. We study the effects of such an operator in a set of observables, in semileptonic $B \to D^{(*)}$ modes as well as in semileptonic $B$ and $B_s$ decays to excited positive parity charmed mesons.

 Slides