Charmonium singlets, open charm and exotic hadrons

TL;DR

This paper reviews the physics of charmonium singlet states, discusses recent hidden-charm states, and explores prospects for producing double-charm baryons and exotic mesons, emphasizing careful interpretation of mass splittings.

Contribution

It provides a critical review of charmonium singlet states, examines new hidden-charm states, and discusses future production possibilities for double-charm hadrons.

Findings

Mass splittings are often of a few MeV, requiring careful comparison.

New hidden-charm states X and Y are briefly reviewed.

Prospects for double-charm baryon and exotic meson production are discussed.

Abstract

Caution is suggested on the comparison of the spin-singlet charmonium P-state with the centre of gravity of triplet states, when the mass splitting is of the order of a few MeV. The physics of new hidden-charm states X and Y is briefly reviewed. Perspectives for producing double-charm baryons and double-charm exotic mesons are discussed.