Discovery of XYZ particles at the BESIII Experiment

TL;DR

This paper reviews the BESIII experiment's significant discoveries of XYZ particles, including tetraquark states and new vector charmoniumlike states, advancing understanding of exotic hadrons containing charm quarks.

Contribution

It provides a comprehensive overview of recent experimental discoveries of XYZ particles at BESIII, highlighting new tetraquark and vector states.

Findings

Discovery of Zc(3900), Zc(4020), Zcs(3985) tetraquark states

Observation of several new vector charmoniumlike states

Enhanced understanding of exotic charmoniumlike structures

Abstract

Charmonium is a bound state of a charmed quark and a charmed antiquark, and a charmoniumlike state is a resonant structure that contains at least a charmed quark-antiquark pair but has properties that are incompatible with a conventional charmonium state. The charmoniumlike states are also called XYZ particles to indicate their underlying nature is still unclear. The BESIII experiment has contributed significantly in the study of the XYZ particles, and here we review the discoveries of the Zc(3900), Zc(4020), and Zcs(3985) tetraquark states and the observations of several new vector charmoniumlike states at the BESIII experiment.