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

作者：Ablikim, M.; Achasov, M. N.; Adlarson, P.; Ahmed, S.; Albrecht, M.; Aliberti, R.; Amoroso, A.; An, M. R.; An, Q.; Bai, X. H.; Bai, Y.; Bakina, O.; Ferroli, R. Baldini; Balossino, I; Ban, Y.; Begzsuren, K.; Berger, N.; Bertani, M.; Bettoni, D.; Bianchi, F.; Bloms, J.; Bortone, A.; Boyko, I; Briere, R. A.; Cai, H.; Cai, X.; Calcaterra, A.; Cao, G. F.; Cao, N.; Cetin, S. A.; Chang, J. F.; Chang, W. L.; Chelkov, G.; Chen, D. Y.; Chen, G.; Chen, H. S.; Chen, M. L.; Chen, S. J.; Chen, X. R.

来源：JOURNAL OF HIGH ENERGY PHYSICS, 2021, (10): 177.

DOI：10.1007/JHEP10(2021)177

• e(+)-e(-) Experiments
• Exotics
• Particle and resonance production
• Quarkonium

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(-)-> eta psi(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.