Evidence for $e^+e^-togammachi_{c1, 2}$ at center-of-mass energies from 4.009 to 4.360 GeV

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 $e^+e^-togammachi_{cJ}$ $(J = 0, 1, 2)$ and find evidence for $e^+e^-togammachi_{c1}$ and $e^+e^-togammachi_{c2}$ with statistical significances of 3.0$sigma$ and 3.4$sigma$, respectively. The Born cross sections $sigma^{B}(e^+e^-togammachi_{cJ})$, as well as their upper limits at the 90% confidence level are determined at each center-of-mass energy.

Search for the Lepton Flavor Violation Process $J/psi to emu$ at BESIII

We search for the lepton-flavor-violating decay of the $J/psi$ into an electron and a muon using $(225.3pm2.8)times 10^{6}$ $J/psi$ events collected with the BESIII detector at the BEPCII collider. Four candidate events are found in the signal region, consistent with background expectations. An upper limit on the branching fraction of $mathcal{B}(J/psi to emu)< 1.5 times 10^{-7}$ (90% C.L.) is obtained.