Measurement of the e+e- ??J /? cross section and search for e+e- ??0J /? at center-of-mass energies between 3.810 and 4.600 GeV

Abstract

Using data samples collected with the BESIII detector operating at the BEPCII collider at 17 center-of-mass energies from 3.810 to 4.600 GeV, we perform a study of e+e-??J/? and ?0J/?. The Born cross sections of these two processes are measured at each center-of-mass energy. The measured energy-dependent Born cross section for e+e-??J/? shows an enhancement around 4.2 GeV. The measurement is compatible with an earlier measurement by Belle. © 2015 American Physical Society.