Measurement of e+e−→ηJ/ψ cross section from s=3.808 GeV to 4.951 GeV

Abstract

Using data samples with an integrated luminosity of 22.42 fb−1 collected by the BESIII detector operating at the BEPCII storage ring, we measure the cross sections of the e+e−→ηJ/ψ process at center-of-mass energies from 3.808 to 4.951 GeV. Three structures are observed in the line shape of the measured cross sections. A maximum-likelihood fit with ψ(4040), two additional resonances, and a nonresonant component are performed. The mass and width of the first additional state are (4219.7±2.5±4.5) MeV/c2 and (80.7±4.4±1.4) MeV, respectively, consistent with the ψ(4230). For the second state, the mass and width are (4386±13±17) MeV/c2 and (177±32±13) MeV, respectively, consistent with the ψ(4360). The first uncertainties are statistical, and the second ones are systematic. The statistical significance of ψ(4040) is 8.0σ and those for ψ(4230) and ψ(4360) are more than 10.0σ. Published by the American Physical Society 2024