Multi-hadron molecules: status and prospect

TL;DR

This paper reviews the recent progress and future prospects in the study of multi-hadron molecules, exotic states composed of multiple hadrons, highlighting their significance in hadron spectroscopy.

Contribution

It provides a concise overview of recent experimental and theoretical developments in multi-hadron molecules across light and heavy flavor sectors, emphasizing future research directions.

Findings

Discovery of numerous exotic hadronic states since 2003

Evidence supporting the existence of multi-hadron molecular states

Identification of key challenges and future research needs in the field

Abstract

Starting from 2003, the discovery of a large amount of the so-called exotic hadronic states, i.e., the $XYZ$ states, the pentaquark states as well as the tetraquark states, have not only revived studies of hadron spectroscopy, but also hinted at the existence of new multi-hadron states made of hadrons other than nucleons and hyperons. We briefly comment on some of the latest studies on multi-hadron molecules in the light and heavy flavor sectors and highlight what should be done in the future.