Evidence for $e^{+}{e}^{-}\to \gamma {\eta }_c(1S)$ at center-of-mass energies between 4.01 and 4.60 GeV

BESIII Collaboration, M. Ablikim, M. N. Achasov +439

We present first evidence for the process $e^{+}{e}^{-}\to \gamma {\eta }_c(1S)$ at six center-of-mass energies between 4.01 and 4.60~GeV using data collected by the BESIII experiment operating at B…