$B^{\ast}_{s1}B^{\ast}K$ form factor from QCD sum rules

TL;DR

This paper calculates the form factors and coupling constant of the $g_{B^{ ext{*}}_{s1}B^{ ext{*}}K}$ vertex using three-point QCD sum rules, considering off-shell states of $B^{ ext{*}}$ and $K$ mesons.

Contribution

It introduces a calculation of the $g_{B^{ ext{*}}_{s1}B^{ ext{*}}K}$ vertex form factors and coupling constant within the three-point QCD sum rules framework, accounting for different off-shell mesons.

Findings

Form factors differ depending on the off-shell meson.

Coupling constant is consistent regardless of off-shell choice.

Provides a method to evaluate vertex form factors in QCD.

Abstract

In this article, we calculate the form factors and the coupling constant of the $g_{B^{\ast}_{s1}B^{\ast} K}$ vertex in the framework of the three-point QCD sum rules. Three point correlation functions responsible for the vertex are evaluated by considering both $B^{\ast}$ and $K$ mesons as off-shell states. The form factors obtained are different if the $B^{\ast}$ or the $K$ meson is off-shell but give the same coupling constant.