Measurements of the Cross Section fore+eHadronsat Center-of-Mass Energies from 2 to 5 GeV

Abstract
We report values of R=σ(e+ehadrons)/σ(e+eμ+μ) for 85 center-of-mass energies between 2 and 5GeV measured with the upgraded Beijing Spectrometer at the Beijing Electron-Positron Collider.