# Distribution Amplitudes of Heavy-Light Mesons

## TL;DR

This paper uses a symmetry-preserving quantum field theory approach to calculate properties of heavy-light mesons, including masses, decay constants, distribution amplitudes, and rare decay rates, relevant for experimental and theoretical studies.

## Contribution

It provides new calculations of heavy-light meson distribution amplitudes, especially the inverse moment of the B-meson, and predicts rare decay branching fractions with corrections.

## Key findings

- Computed the inverse moment of the B-meson distribution: 0.54(3) GeV.
- Predicted the branching fraction for B→γℓν decay: 0.47(15) for Eγ > 1.5 GeV.
- Calculated masses, decay constants, and distribution amplitudes of heavy-light mesons.

## Abstract

A symmetry-preserving approach to the continuum bound-state problem in quantum field theory is used to calculate the masses, leptonic decay constants and light-front distribution amplitudes of empirically accessible heavy-light mesons. The inverse moment of the $B$-meson distribution is particularly important in treatments of exclusive $B$-decays using effective field theory and the factorisation formalism; and its value is therefore computed: $\lambda_B(\zeta = 2\,{\rm GeV}) = 0.54(3)\,$GeV. As an example and in anticipation of precision measurements at new-generation $B$-factories, the branching fraction for the rare $B\to \gamma(E_\gamma) \ell \nu_\ell$ radiative decay is also calculated, retaining $1/m_B^2$ and $1/E_\gamma^2$ corrections to the differential decay width, with the result $\Gamma_{B\to \gamma \ell \nu_\ell}/\Gamma_B = 0.47(15)$ on $E_\gamma > 1.5\,$GeV.