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 — preprints:2002:ttp02-27 [2016/03/15 20:39] (current) Line 1: Line 1: + ====== TTP02-27 Determination of $\alpha_s$ and the charm and bottom quark masses from recent measurements of $R(s)$ ====== + + + Recent experimental data for the total cross + ​section $\sigma(e^+e^-\to\mbox{hadrons})$ are compared + with the up-to-date + ​theoretical prediction of perturbative QCD for those energies where + ​perturbation theory is reliable. This allows for a + ​determination of the strong coupling + ​$\alpha_s^{(4)}(5~\mbox{GeV})=0.235\pm0.047$. + The precise data from the charm threshold region, + when combined with the recent evaluation of moments with three loop + ​accuracy,​ lead to a direct determination of the short distance + ​$\overline{\rm MS}$ charm quark mass $m_c(m_c)=1.304(27)$. + ​Applying the + same approach to the bottom quark we obtain $m_b(m_b)=4.191(51)$~GeV. + ​ + |**J.H. K\"uhn and M. Steinhauser** ​ | + |**  Proceedings of ICHEP 2002, Elsevier Science B.V., Bentvelsen et al. Eds.    539-541 2002  **  | + | {{preprints:​2002:​ttp02-27.pdf|PDF}} {{preprints:​2002:​ttp02-27.ps|PostScript}} ​  | + | |