Evidence for $e^{+}{e}^{-}\to {\hat{I}}^3\ddot{I}{‡}_{c1,2}$ at center-of-mass energies from 4.009 to 4.360 GeV

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 $e^{+}{e}^{-}\to {\hat{I}}^3\ddot{I}{‡}_{cJ}$ $(J=0,1,2)$ and find evidence for $e^{+}{e}^{-}\to {\hat{I}}^3\ddot{I}{‡}_{c1}$ and $e^{+}{e}^{-}\to {\hat{I}}^3\ddot{I}{‡}_{c2}$ with statistical significances of 3.0$\ddot{I}ƒ$ and 3.4$\ddot{I}ƒ$, respectively. The Born cross sections $\ddot{I}{ƒ}^B(e^{+}{e}^{-}\to {\hat{I}}^3\ddot{I}{‡}_{cJ})$, 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