X(3872) revisited: the roles of OPEP and the quark degrees of freedom

TL;DR

This paper revisits the X(3872) particle using a hybrid model combining quark and hadron degrees of freedom, highlighting the roles of one-pion exchange and quark interactions in forming its structure.

Contribution

It introduces a quark-hadron hybrid model to analyze X(3872), emphasizing the impact of OPEP and quark couplings on its near-threshold behavior.

Findings

A very narrow peak appears at the D0 D*0 threshold.

The pole position is near the physical sheet, consistent with experimental data.

The model explains the X(3872) as a coupled-channel state.

Abstract

The $X(3872)$ is investigated by employing the quark-hadron hybrid model, that consists of the $c\bar c$ core, $D^{(*)}\bar D{}^*$, $J/\psi\omega$, and $J/\psi\rho$ two-meson states. Due to the attraction from the $c\bar c$-$D\bar D{}^*$ coupling and from the OPEP tensor coupling, a very thin peak can appear at the $D^{0}\bar D{}^{*0}$ threshold. The energy of the corresponding pole of the scattering matrix is $E=(+0.06-0.14i)$ MeV, which is on the physical sheet and above the threshold, the same as the one of the poles from the LHCb data analysis.