New charmonium-like states

TL;DR

This paper reviews recent experimental discoveries of numerous new charmonium-like states, discussing their potential interpretations and the future prospects for understanding this complex spectrum.

Contribution

It provides a comprehensive overview of the experimental evidence for new charmonium-like states and discusses possible theoretical interpretations and future research directions.

Findings

Evidence for multiple new states with hidden charm

Discussion of conventional and exotic interpretations

Prospects for clarifying the charmonium spectrum

Abstract

In recent years the B-factories and other machines have found evidence for a large number of new states with hidden charm: candidate h_c(1P), eta_c(2S), and chi_{c2}(2P) states; the well-established X(3872); enhancements called X(3940), Y(3940), and Y(4260); and a new structure at 4350 MeV. Various conventional-charmonium and more exotic interpretations of these data have been proposed. In this talk we review the current state of the experimental evidence and the prospects for clarifying the spectrum.