Prediction of a missing higher charmonium around 4.26 GeV in J/ψ family

Abstract

Inspired by the similarity between the mass gaps of the J/ψ and Υ families, the prediction of a missing higher charmonium with mass 4,263 MeV and very narrow width is made. In addition, the properties of two charmonium-like states, X(3940) and X(4160), and charmonium ψ(4415) are discussed, where our calculation shows that X(3940) as ηc(3S) is established, while the explanation of X(4160) to be ηc(4S) is fully excluded and that ηc(4S) is typically a very narrow state. These predictions might be accessible at BESIII, Belle, and BelleII in near future.