Measurement of the cross section of (Formula Presented.) at center-of-mass energies between 3.510 and 4.843 GeV

Abstract

Using e + e − collision data corresponding to a total integrated luminosity of 12.9 fb−1 collected with the BESIII detector at the BEPCII collider, the exclusive Born cross sections and the effective form factors of the reaction (Formula Presented.) are measured via the single baryon-tag method at 23 center-of-mass energies between 3.510 and 4.843 GeV. Evidence for the decay (Formula Presented.) is observed with a significance of 4.5σ by analyzing the measured cross sections together with earlier BESIII results. For the other charmonium(-like) states ψ(4040), ψ(4160), Y(4230), Y(4360), ψ(4415), and Y(4660), no significant signal of their decay to (Formula Presented.) is found. For these states, upper limits of the products of the branching fraction and the electronic partial width at the 90% confidence level are provided. [Figure not available: see fulltext.].