Y(4260) --> gamma + X(3872) in the diquarkonium picture

TL;DR

This paper models the decay Y(4260) to gamma plus X(3872) within a diquarkonium framework, estimating transition rates and deriving bounds based on non-relativistic calculations and experimental data.

Contribution

It provides the first non-relativistic estimate of the radiative transition rate in the diquarkonium model for Y(4260) and X(3872), connecting theoretical predictions with experimental bounds.

Findings

Estimated Gamma_{ m rad} as 496 keV for I=0 and 179 keV for I=1.

Derived upper bounds for decay branching ratios and widths based on the model and data.

Predicted results to be tested with upcoming collider experiments.

Abstract

The observed Y(4260)\to \gamma + X(3872) decay is a natural consequence of the diquark-antidiquark description of Y and X resonances. In this note we attempt an estimate of the transition rate, \Gamma_{\rm rad}, by a non-relativistic calculation of the electric dipole term of a diquarkonium bound state. We compute \Gamma_{\rm rad} for generic composition values of the isospin of X and Y. Specializing to I=0 for X(3872), we find \Gamma_{\rm rad}= 496~keV for Y(4260) with I=0 and \Gamma_{\rm rad}= 179~keV for I=1. Combining with BESIII data, we derive upper bounds to B(Y\to J/\Psi+\pi+\pi) and to \Gamma(Y\to \mu^+ \mu^-). We expect to confront these results with forthcoming data from electron-positron and hadron colliders.