Inverse moment of the $B_s$-meson distribution amplitude from QCD sum rule

TL;DR

This paper derives a QCD sum rule for the inverse moment of the $B_s$-meson distribution amplitude, accounting for SU(3) symmetry violation, and predicts the ratio of inverse moments relevant for B-meson decay analyses.

Contribution

It introduces a new QCD sum rule for the inverse moment of the $B_s$-meson distribution amplitude, including SU(3) symmetry violation effects.

Findings

Predicted ratio of inverse moments $oxed{rac{ ext{}\lambda_{B_s}}{ ext{ ext}\lambda_B} = 1.19 \, extpm \, 0.14}$.

Identified sources of SU(3) symmetry violation in the distribution amplitude.

Provided a theoretical tool for analyzing $B_s$-meson decays.

Abstract

We derive a QCD sum rule for the inverse moment of the $B_s$-meson light-cone distribution amplitude in HQET. Within this method, the $SU(3)_{fl}$ symmetry violation is traced to the strange quark mass and to the difference between strange and nonstrange quark condensate densities. We predict the ratio of inverse moments $\lambda_{B_s}/\lambda_B= 1.19 \pm 0.14$ which can be used in various applications of these distribution amplitudes to the analyses of $B_{s}$-meson decays, provided an accurate value of $\lambda_B$ is available from other sources, such as the $B\to \ell \nu_\ell \gamma$ decay.