Evidence for $e^+e^-\toγÏ_{c1, 2}$ at center-of-mass energies from 4.009 to 4.360 GeV
arXiv:1411.6336 · doi:10.1088/1674-1137/39/4/041001
Abstract
Using data samples collected at center-of-mass energies of $\sqrt{s}$ = 4.009, 4.230, 4.260, and 4.360 GeV with the BESIII detector operating at the BEPCII collider, we perform a search for the process $e^+e^-\toγÏ_{cJ}$ $(J = 0, 1, 2)$ and find evidence for $e^+e^-\toγÏ_{c1}$ and $e^+e^-\toγÏ_{c2}$ with statistical significances of 3.0$Ï$ and 3.4$Ï$, respectively. The Born cross sections $Ï^{B}(e^+e^-\toγÏ_{cJ})$, as well as their upper limits at the 90% confidence level are determined at each center-of-mass energy.
8 pages, 7 figures, 3 tables