Cross section measurement of e+e- →π+π-ψ (3686) from s =4.0076 GeV to 4.6984 GeV CROSS SECTION MEASUREMENT of e+e- →π+π-ψ (3686) ... ABLIKIM M. et al.

Abstract

Using data samples with a total integrated luminosity of 20.1 fb-1 collected by the BESIII detector operating at the BEPCII collider, the cross section of the process e+e-→π+π-ψ(3686) is measured at center-of-mass energies between 4.0076 and 4.6984 GeV. The measured cross section is consistent with previous results, and with much improved precision. A fit to the measured energy-dependent cross section, which includes three Breit-Wigner functions and a nonresonant contribution, confirms the existence of the charmonium-like states Y(4220), Y(4390), and Y(4660). This is the first observation of the Y(4660) at the BESIII experiment. © 2021 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.