Strange quark mass from e+e- revisited and present status of light quark masses

We reconsider the determinations of the strange quark mass m(s) from e(+)e(-) into hadrons data using a new combination of finite energy sum rules (FESR) and revisiting the existing tau-like sum rules by including nonresonant contributions to the spectral functions. To order alpha(3)(s) and including the tachyonic gluon mass lambda(2) contribution, which phenomenologically parametrizes the UV renormalon effect into the perturbative series, we obtain the invariant mass m(s)=(119 +/- 17) MeV leading to m(s)(2 GeV)=(104 +/- 15) MeV. Combining this value with the recent and independent phenomenological determinations from some other channels, to order alpha(3)(s) and including lambda(2), we deduce the weighted average m(s)(2 GeV)=(96.1 +/- 4.8) MeV. The positivity of the spectral functions in the (pseudo)scalar (resp. vector) channels leads to the lower (resp. upper) bounds of m(s)(2 GeV): (71 +/- 4) MeV <= m(s)(2 GeV)<=(151 +/- 14) MeV, to order alpha(3)(s). Using the chiral perturbation theory (ChPT) mass ratio r(3)equivalent to 2m(s)/(m(u)+m(d))=24.2 +/- 1.5, and the average value of m(s), we deduce (m(u)+m(d))(2 GeV)=(7.9 +/- 0.6) MeV, consistent with the pion sum rule result, which, combined with the ChPT value for m(u)/m(d), gives m(d)(2 GeV)=(5.1 +/- 0.4) MeV and m(u)(2 GeV)=(2.8 +/- 0.2) MeV. Finally, using (m(u)+m(d)) from the pion sum rule and the average value of m(s) (without the pion sum rule), the method gives r(3)=23.5 +/- 5.8, in perfect agreement with the ChPT ratio, indicating the self-consistency of the sum rule results. Using the value m(b)(m(b))=(4.23 +/- 0.06) GeV, we also obtain the scale-independent mass ratio m(b)/m(s)=50 +/- 3, which is useful for model-buildings. Absolute values of the light quark masses from QCD spectral sum rules reported in this paper are the most accurate determinations to date.