The
BES
collaboration
Bai, J.Z.
;
Ban, Y.
;
Bian, J.G.
;
et al.
Phys.Rev.Lett. 88 (2002) 101802, 2002.
https://inspirehep.net/literature/552757
Inspire Record
552757
DOI
10.17182/hepdata.41990
https://doi.org/10.17182/hepdata.41990
We report values of $R = \sigma(e^+e^-\to {hadrons})/\sigma(e^+e^-\to\mu^+\mu^-)$ for 85 center-of-mass energies between 2 and 5 GeV measured with the upgraded Beijing Spectrometer at the Beijing Electron-Positron Collider.