# XXVII International Workshop on Deep Inelastic Scattering and Related Subjects

Apr 8 – 12, 2019
Turin
Europe/Rome timezone

## Radiative leptonic decay $B\to \gamma \ell \nu_\ell$ with subleading power corrections

Apr 10, 2019, 10:45 AM
35m
Rettorato - Sala Athenaeum

### Rettorato - Sala Athenaeum

Via Verdi, 8 Turin
Parallel Session Talk WG5: Physics with Heavy Flavours

### Speaker

Yao Ji (University of Regensburg)

### Description

We discuss the QCD predictions for the radiative decay $B\to \gamma \ell \nu_\ell$ with an energetic photon in the final state by taking into account the $1/E_\gamma, 1/m_b$ power-suppressed hard-collinear and soft corrections from higher-twist $B$-meson light-cone distribution amplitudes (LCDAs). The soft contribution is estimated through a dispersion relation and light-cone QCD sum rules. The analysis of theoretical uncertainties and the dependence of the decay form factors on the leading-twist LCDA $\phi_+(\omega)$ shows that the latter dominates. The radiative leptonic decay is therefore well suited to constrain the parameters of $\phi_+(\omega)$, including the first inverse moment, $1/\lambda_B$, from the expected high-statistics data of the BELLE II experiment.

### Primary author

Yao Ji (University of Regensburg)

### Co-authors

Prof. Martin Beneke (Technical University Munich) Prof. Vladimir Braun (University of Regensburg) Dr Yan-Bing Wei (Nankai University)