Muon and tau anomalies updated

We present a new independent evaluation of the hadronic vacuum polarization contributions a(l)(had) (l.o) = 1/2 (g-2)(l)(had)(l.o) to the anomalous magnetic moment (anomaly) of the muon and tau leptons using tau -decays and e(+)e(-) data. The alone theoretical input used for describing the high-energy region not accessible experimentally is perturbative QCD plus (negligible) additional effects due to the QCD vacuum condensates. We obtain: a(mu)(had) (l.o.) = 7020.6(75.6) x 10(-11) and a(tau)(had)(l.o.) = 353.6(3.8) x 10(-8), which we compare with previous determinations. Confronting the theoretical Standard Model (SM) predictions of lip with the recent BNL measurement leads to a(mu)(new) = a(mu)(exp) - a(mu)(SM) = 333(173) x 10(-11) Combined with existing determinations, this leads to the conservative range: 112 less than or equal to a(mu)(new) x 10(11) less than or equal to 573 at 90% CL, from which we derive lower bounds on the scales of some new physics. We also update our old and first predictions of the SM contributions to a, Including QED to sixth order, higher order hadronic and electroweak contributions, we obtain asm = alpha (SM)(tau) = 117711(12) x 10(-8), waiting for a future precise measurement of alpha (tau) (C) 2001 Elsevier Science B.V. All rights reserved.