Measurements of $e^{+}{e}^{-}\to e^{+}{e}^{-}$, $e^{+}{e}^{-}\to {\mu }^{+}{\mu }^{-}$, and $e^{+}{e}^{-}\to \gamma \gamma$ at Center-of-Mass Energies Close to 3105 MeV

Independent evidence is presented for the decay of the recently discovered particle $\psi \mathrm{}\left(3105\right)\mathrm{}$ into electron-positron pairs and new evidence is presented for the decay of this particle into muon pairs. Measurements of the rate of the reaction $e^{+}{e}^{-}\to \gamma \gamma$ at center-of-mass energies in the vicinity of 3105 MeV are also reported.