Observation of e + e − → ηψ(2S) at center-of-mass energies from 4.236 to 4.600 GeV

Journal of high energy physics 2021(10), 177 (2021). doi:10.1007/JHEP10(2021)177
Using a total of 5.25 fb$^{���1}$ of e$^{+}$e$^{���}$ collision data with center-of-mass energies from 4.236 to 4.600 GeV, we report the first observation of the process e$^{+}$e$^{���}$��� ����(2S) with a statistical significance of 4.9 standard deviations. The data sets were collected by the BESIII detector operating at the BEPCII storage ring. We measure the yield of events integrated over center-of-mass energies and also present the energy dependence of the measured cross section.[graphic not available: see fulltext]
Published by SISSA, [Trieste]