Glueball-meson molecules

TL;DR

This paper explores the possibility that certain observed meson states are actually molecular states formed from glueballs and mesons, offering an alternative to direct glueball detection.

Contribution

It introduces the concept of glueball-meson molecules and discusses their potential role in explaining observed excited meson states and the nature of $XYZ$ states.

Findings

Glueball-meson molecules could explain the structure of some excited mesons.

Wave functions of observed mesons may contain significant glueball-meson molecular components.

Potential charmless contributions to $XYZ$ states are discussed.

Abstract

Experimental searches for pure glueball states have proven challenging and so far yielded no results. This is believed to occur because glueballs mix with the ordinary $q\bar q$ states with the same quantum numbers. We will discuss an alternative mechanism, the formation of the glueball-meson molecular states. We will argue that the wave functions of already observed excited meson states may contain a significant part due to such molecular states. We discuss the phenomenology of glueball-meson molecules and comment on a possible charmless component of the $XYZ$ states.