Study of X(5568) in a unitary coupled-channel approximation of $B \bar{K}$ and $B_s \pi$

TL;DR

This paper models the interaction between B mesons and pseudoscalar mesons to dynamically generate and analyze the properties of the X(5568) resonance and related states using a coupled-channel approach.

Contribution

It introduces a next-to-leading order Lagrangian-based coupled-channel framework to study B meson interactions and dynamically generate resonant states like X(5568).

Findings

A resonant state near 5568 MeV with J^P=0^+ is generated.

An axial-vector state near 5620 MeV with J^P=1^+ is produced.

The mass and width depend on regularization scheme parameters.

Abstract

The potential of the $B$ meson and the pseudoscalar meson is constructed up to the next-to-leading order Lagrangian, and then the $B \bar{K}$ and $B_s \pi$ interaction is studied in the unitary coupled-channel approximation, and a resonant state with a mass about $5568MeV$ and $J^P=0^+$ is generated dynamically, which can be associated with the $X(5568)$ state announced by D0 Collaboration recently. The mass and the decay width of this resonant state depend on the regularization scale in the dimensional regularization scheme, or the maximum momentum in the momentum cutoff regularization scheme. The scattering amplitude of the vector $B$ meson and the pseudoscalar meson is calculated, and an axial-vector state with a mass near $5620MeV$ and $J^P=1^+$ is produced. Moreover, their partners in the charm sector are also discussed.