$R$ value measurements for $e^{+}{e}^{-}$ annihilation at 2.60, 3.07 and 3.65 GeV

The BES Collaboration, M. Ablikim

Using a data sample with a total integrated luminosity of 10.0 pb${}^{-1}$ collected at center-of-mass energies of 2.6, 3.07 and 3.65 GeV with BESII, cross sections for $e^{+}{e}^{-}$ anni…