Hadronic width of theZfrom a global fit toe+e−→ hadrons data

A global analysis of the ${\mathit{e}}^{+}$ ${\mathit{e}}^{\mathrm{-}}$→hadrons data is presented to extract an effective value for the strong-interaction correction to the quark-parton-model approximation to be used for the Z hadronic width. We obtain ${\mathrm{\Gamma }}_{\mathit{h}}$=1782±17(fit)±15 [electroweak (EW) theory] MeV, and a ratio ${\mathrm{\Gamma }}_{\mathit{h}}$/${\mathrm{\Gamma }}_{\mathit{l}}$=21.32±0.24, in good agreement with the results from the CERN collider LEP, and different from the two-loop QCD predictions, ${\mathrm{\Gamma }}_{\mathit{h}}$=1735±6(${\mathrm{\alpha }}_{\mathit{s}}$)±15(EW theory) MeV and ${\mathrm{\Gamma }}_{\mathit{h}}$/${\mathrm{\Gamma }}_{\mathit{l}}$=20.74±0.12, corresponding to ${\mathrm{\Lambda }}_{\mathrm{MS}}$ ${\mathrm{¯}}^{\mathrm{}\left(5\right)\mathrm{}}$=${140}_{\mathrm{-}80}^{+100\mathrm{}}$ MeV, where MS¯ denotes the modified minimal-subtraction scheme.