Precision measurement of the branching fraction for the decay $\psi (2S)\to {\tau }^{+}{\tau }^{-}$

BESIII Collaboration, M. Ablikim, M. N. Achasov +684

Using $(2259.3\pm 11.1)\times 10^6$ $\psi (2S)$ events acquired with the BESIII detector, the branching fraction of $\psi (2S)\to {\tau }^{+}{\tau }^{-}$ is measured with improved precision t…