On the hidden charm state at 3872 MeV

Abstract

We discuss some puzzling aspects of the narrow hidden charm resonance that was recently discovered by the Belle Collaboration at mass 3872 MeV. In order to determine its quantum numbers, a crucial piece of information is the spin of the dipion in the decay final state π+π−J/ψ. We give the angular distributions and correlations of the final particles in the decay which will provide this information about the nature of this resonance.