paper

Cross section measurement of at

arXiv:2105.13597 · doi:10.1103/PhysRevD.104.092014

Abstract

The cross sections of the process are measured at fifteen center-of-mass energies from to with the BESIII detector at the Beijing Electron Positron Collider (BEPCII). The results are found to be consistent with those obtained by BaBar. A resonant structure around is observed, with a mass and width of and , respectively, where the first uncertainties are statistical and the second ones are systematic. The product of its radiative width () with its branching fraction to () is .