Radiative decay of hadronic molecule state for quarks

TL;DR

This paper develops a general formalism for calculating the radiative decay widths of meson-meson molecular states and applies it to the X(3915) state, showing consistency with experimental data.

Contribution

It introduces a new general formula for the decay widths of vector meson molecular states into two photons, applicable to arbitrary spin and parity.

Findings

The decay width of X(3915) to two photons matches experimental measurements.

The formalism can be used for other meson-meson molecular states.

Provides a theoretical framework for understanding exotic hadronic states.

Abstract

Using the general form of the generalized Bethe-Salpeter wave functions for four-quark states describing the meson-meson molecular structure given in our previous work, we obtain the general formulas for the decay widths of molecular states composed of two vector mesons with arbitrary spin and parity into two photons. Then this general formalism is applied to investigate the radiative two-photon decay of the obeserved \emph{X}(3915) state, where this exotic state \emph{X}(3915) is considered as a molecular state consisting of two heavy vector mesons $D^{*0}\bar{D}^{*0}$. The numerical result of decay mode $\emph{X}(3915)\rightarrow \gamma\gamma$ is consistent with the experimental values.