Determination of the structure of the $X(3872)$ in $\bar p A$ collisions

TL;DR

This paper investigates the internal structure of the $X(3872)$ meson by proposing experimental methods involving $ar p A$ collisions to distinguish between different theoretical models such as molecular, tetraquark, or hybrid states.

Contribution

It introduces a novel experimental approach using $ar p A$ collisions to test the molecular hypothesis of the $X(3872)$ meson structure.

Findings

Proposes $D$ or $ar D^{*}$ stripping reactions as a test method.

Suggests strong coupling of $X(3872)$ to $ar p p$ channel.

Provides a framework for experimental verification of meson structure.

Abstract

Currently, the structure of the $X(3872)$ meson is unknown. Different competing models of the $c\bar c$ exotic state $X(3872)$ exist, including the possibilities that this state is either a mesonic molecule with dominating $D^0 \bar D^{*0} +c.c.$ composition, a $c \bar c q \bar q$ tetraquark, or a $c \bar c$-gluon hybrid state. It is expected that the $X(3872)$ state is rather strongly coupled to the $\bar p p$ channel and, therefore, can be produced in $\bar p p$ and $\bar pA$ collisions at PANDA. We propose to test the hypothetical molecular structure of $X(3872)$ by studying the $D$ or $\bar D^{*}$ stripping reactions on a nuclear residue.