The $Z_c^{(\prime)} \to \eta_c \rho$ decay as a discriminant between tetraquarks and meson molecules

TL;DR

This paper proposes using the decay process Z_c^{(\prime)} o \eta_c ho as a way to distinguish between tetraquark and meson molecule models of exotic XYZ resonances, which are currently not well understood.

Contribution

It introduces a novel decay channel analysis to differentiate between tetraquark and meson molecule models of XYZ resonances.

Findings

Predictions for decay rates differ significantly between models

The decay channel can serve as a discriminant in experiments

Provides a new approach to understanding exotic hadrons

Abstract

Understanding the nature of the exotic XYZ resonances is one of the open problems in hadronic spectroscopy. Despite the experimental efforts, the structure of these particles still lacks of an accepted theoretical framework. We propose to use the $Z_c^{(\prime)} \to \eta_c \rho$ decays as a possible discriminant between two of the most popular models: the compact tetraquark and the loosely bound meson molecule. We show that the predictions obtained within the two pictures are significantly different and therefore the proposed decay channel might shed some light on the nature of these states.