Determination of the number of $\psi (3686)$ events at BESIII

M. Ablikim, M. N. Achasov, S. Ahmed +430

The numbers of $\psi (3686)$ events accumulated by the BESIII detector for the two rounds of data taking during 2009 and 2012 are determined to be $(107.0\pm 0.8)\times 10^6$ and $(341.…