Strange-quark mass effects in the $B_s$ meson's light-cone distribution amplitude

TL;DR

This paper analyzes how the non-zero strange-quark mass affects the light-cone distribution amplitudes of $B_s$ mesons, extending calculations of matching coefficients and comparing with QCD sum rule results.

Contribution

It extends the calculation of matching coefficients for $B_s$ meson LCDAs to include linear $m_s$ terms and compares the shape effects with recent sum rule findings.

Findings

Strange-quark mass influences the shape of $B_s$ LCDAs.

Extended matching coefficients include linear $m_s$ effects.

Results align with recent sum rule inverse moments.

Abstract

We investigate the differences between the light-cone distribution amplitudes (LCDAs) of $B_s$ mesons and $B_q$ mesons (with $q=u,d$) induced by a non-vanishing strange-quark mass $m_s\neq 0$ (compared to $m_q \simeq 0$). To this end, we consider the so-called ''radiative tail'' which is related to the short-distance expansion of the relevant light-ray operators in heavy-quark effective theory. We extend the calculation of the according matching coefficients, including operators linear in $m_s$ for both the leading and sub-leading 2-particle LCDAs. Based on a generic parameterization for the leading LCDA, we discuss the effect on its shape on a quantitative level, and compare our findings with recent results on the inverse moments of the $B_q$ and $B_s$ LCDAs from QCD sum rules.