Final R-value results from 2-5 GeV from BES and QCD test with R scan data

W. B. Yan, W. G. Li, Z. G. Zhao

Final results of the measurement of $R=\sigma (e^{+}{e}^{-}\to hadrons)/\sigma (e^{+}{e}^{-}\to {\mu }^{+}{\mu }^{-})$ in the energy region from 2 to 5 GeV with the upgraded Beijing Spectrometer (BESII) at the Bei…