Evidence for resonant structures in e+e- to pi+pi-h_c

Abstract

The cross sections of e+e- to pi+pi-h_c at center-of-mass energies from 3.90 to 4.42 GeV were measured by the BESIII and the CLEO-c experiments. Resonant structures are evident in the e+e- to pi+pi-h_c line shape, the fit to the line shape results in a narrow structure at a mass of (4216\pm 18) MeV/c^2 and a width of (39\pm 32) MeV, and a possible wide structure of mass (4293\pm 9) MeV/c^2 and width (222\pm 67) MeV. Here the errors are combined statistical and systematic errors. This may indicate that the Y(4260) state observed in e+e- to pi+pi-J/psi has fine structure in it.