Updated estimate of the muon magnetic moment using revised results from e+e- annihilation

A new evaluation of the hadronic vacuum polarization contribution to the muon magnetic moment is presented. We take into account the reanalysis of the low-energy ee annihilation cross section into hadrons by the CMD-2 Collaboration. The agreement between ee and $tau$ spectral functions in the $pipi$ channel is found to be much improved. Nevertheless, significant discrepancies remain in the center-of-mass energy range between 0.85 and $1.0 {rm GeV}/c^2$.The deviations from the measurement at BNL are found to be $(22.1 pm 7.2 pm 3.5 pm 8.0)~10^{-10}$ (1.9 $sigma$) and $(7.4 pm 5.8 pm 3.5 pm 8.0)~10^{-10}$ (0.7 $sigma$) for the ee- and $tau$-based estimates, respectively, where the second error is from the nonhadronic contributions and the third one from the BNL measurement. Taking into account the $rho^- - rho^0$ mass splitting determined from the measured spectral functions increases the $tau$-based estimate and leads to a worse discrepancy between the two estimates.