$B_{(s)}$ to Light Axial Vector Meson Form Factors via LCSR in HQEFT with Applications to Semileptonic Decays

TL;DR

This paper calculates $B_{(s)}$ to light axial vector meson form factors using LCSR within HQEFT, providing theoretical predictions for semileptonic decay observables that can be tested experimentally.

Contribution

It introduces a method to compute $B_{(s)}$ to axial vector meson form factors via LCSR in HQEFT, including twist-3 DAs and applications to decay phenomenology.

Findings

Derived explicit form factor expressions in LCSR framework.

Provided numerical predictions for decay observables.

Demonstrated penguin form factors relate to semileptonic ones.

Abstract

In the present work, the form factors of $B_{(s)}$ to light P-wave axial vector mesons are calculated via the light cone sum rules (LCSR) in the framework of heavy quark effective field theory (HQEFT). Firstly, the expressions of form factors in terms of the light cone distribution amplitudes (DAs) of axial vector mesons are derived via the LCSR at the leading order of heavy quark expansion. It is found that the penguin type form factors can be obtained directly from the corresponding semileptonic ones, which is similar to the case of S-wave mesons. Considering the light axial vector meson DAs to twist-3, we give the numerical results of form factors systematically. As applications, we investigate the branching ratios, longitudinal polarization fractions and forward-backward asymmetries of relevant semileptonic decays induced by charged current. Our results may be tested by more precise experiments in the future.