$B_{(s)}\to S$ transitions in the light cone sum rules with the chiral current

TL;DR

This paper calculates form factors for $B_{(s)}$ decays to scalar mesons using light-cone sum rules with chiral currents, revealing no twist-3 contributions and aligning with SCET predictions, aiding experimental identification of scalar mesons.

Contribution

It introduces a novel LCSR approach with chiral currents that excludes twist-3 contributions, providing new insights into $B_{(s)}$ to scalar meson transitions.

Findings

Form factors satisfy SCET predictions.

No twist-3 contributions in the sum rules.

Results align with other theoretical approaches.

Abstract

$B_{(s)}$ semi-leptonic decays to the light scalar meson, $B_{(s)}\to S l\bar{\nu}_l, S l \bar{l}\,\,(l=e,\mu,\tau)$, are investigated in the QCD light-cone sum rules (LCSR) with chiral current correlator. Having little knowledge of ingredients of the scalar mesons, we confine ourself to the two quark picture for them and work with the two possible Scenarios. The resulting sum rules for the form factors receive no contributions from the twist-3 distribution amplitudes (DA's), in comparison with the calculation of the conventional LCSR approach where the twist-3 parts play usually an important role. We specify the range of the squared momentum transfer $q^2$, in which the operator product expansion (OPE) for the correlators remains valid approximately. It is found that the form factors satisfy a relation consistent with the prediction of soft collinear effective theory (SCET). In the effective range we investigate behaviors of the form factors and differential decay widthes and compare our calculations with the observations from other approaches. The present findings can be beneficial to experimentally identify physical properties of the scalar mesons.