SCET 2023

Structure-Dependent QED Effects in Exclusive B Decays at Subleading Power

29 Mar 2023, 11:30

40m

Room 310, Building 91 (Lawrence Berkeley National Lab)

Session 9

Speakers

Claudia Cornella (JGU Mainz)Prof. Matthias Neubert (JGU Mainz)

Description

We derive a factorization theorem for the structure-dependent QED effects in the weak exclusive process $B^{-}\to {\mu }^{-}{\overline{\nu }}_{\mu }$, i.e., effects probing the internal structure of the $B$ meson. The derivation requires a careful treatment of endpoint-divergent convolutions common to subleading-power factorization formulas. We find that the decay amplitude is sensitive to two- and three-particle light-cone distribution amplitudes of the $B$ meson as well as to a new hadronic quantity $F(\mu ,\mathrm{\Lambda },v_B\cdot v_{\ell })$, which generalizes the notion of the $B$-meson decay constant in the presence of QED effects. This is one of the first derivations of a subleading-power factorization theorem in which the soft functions are non-perturbative hadronic matrix elements.

Presentation materials

Neubert-Cornella.pdf