Perturbative QCD fitting of KEDR and BESIII $e^{+}{e}^{-}$ data for R(s) and $\hat{I}{\pm }_s$ determination

A. L. Kataev, K. Yu. Todyshev

The experimental data collected by KEDR and BESIII collaborations at the energies below charm quark thresholds are compared with the massless QCD expressions for the $e^{+}{e}^{-}$ annih…