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.
Предметные области OECD FOS+WOS
- 1.03 ФИЗИЧЕСКИЕ НАУКИ И АСТРОНОМИЯ