Towards nature of the X(3872) resonance

TL;DR

This paper develops analytical decay spectra for the X(3872) resonance, enabling model selection and exploring its nature as a charmonium state influenced by D* meson thresholds, with implications for its decay channels.

Contribution

It introduces a method to analyze X(3872) decay spectra that helps determine its structure and coupling constants, considering its possible charmonium nature and threshold effects.

Findings

Spectra effectively distinguish models of X(3872)

Estimated coupling constant with D*0 D̄0 channel

Predicted significant decay modes via two gluons

Abstract

We construct spectra of decays of the resonance X(3872) with good analytical and unitary properties which allows to define the branching ratio of the X(3872) \to D^{*0}\bar D^0 + c.c. decay studying only one more decay, for example, the X(3872)\to\pi^+\pi^- J/\psi(1S) decay, and show that our spectra are effective means of selection of models for the resonance X(3872). Then we discuss the scenario where the X(3872 resonance is the c\bar c = \chi_{c1}(2P) charmonium which "sits on" the D^{*0}\bar D^0 threshold. We explain the shift of the mass of the X(3872) resonance with respect to the prediction of a potential model for the mass of the \chi_{c1}(2P) charmonium by the contribution of the virtual D^*\bar D+c.c. intermediate states into the self energy of the X(3872) resonance. This allows us to estimate the coupling constant of the X(7872) resonance with the D^{*0}\bar D^0 channel, the branching ratio of the X(3872) \to D^{*0}\bar D^0 + c.c. decay, and the branching ratio of the X(3872) decay into all non-D^{*0}\bar D^0 + c.c. states. We predict a significant number of unknown decays of X(3872) via two gluons:X(3872)\to gluons\ gluon\to hadrons.