Electroweak radiative corrections toτdecay

Electroweak model and constraints on new physics

“…123 and found to be under control. The largest effect is due to higher-order electroweak corrections [39] but introduces a negligible uncertainty [124]. In the following we view the 1.7 σ difference as a fluctuation and average the results.…”

“…Martin, Outhwaite, Ryskin [32] 0.02741 ± 0.00019 includes new BES data Burkhardt & Pietrzyk [33] 0.02763 ± 0.00036 PQCD for √ s > 12 GeV de Troconiz & Yndurain [34] 0.02754 ± 0.00010 PQCD for s > 2 GeV 2 Jegerlehner [35] 0.02766 ± 0.00013 converted from MOM scheme (b) The Fermi constant, G F = 1.16637(1) × 10 −5 GeV −2 , determined from the muon lifetime formula [39,40], …”

Tau Decays and αs

“…τ , V ud denotes the CKM weak mixing matrix element, S EW accounts for electroweak radiative corrections [10], the term δ (0) is the dominant massless perturbative contribution, δ EW = 0.0010 corresponds to the residual non-logarithmic electroweak correction [11], δ (2,m q ) arises from quark masses which is smaller than 0.1% for the u, d quarks, and δ (D) are the OPE terms in powers of s D/2 0 . Depending on how the perturbative series is truncated, there are different schemes in the α s expansion.…”

Measurement of tau lepton branching fractions

“…The currents are of the form, (2.17) where the coupling constants f7r and fK are measured very precisely from the decays 7r--+iiJ.lJ.t-and 1<--+iiJ.lJ.t- [8]. Additional electroweak radiative corrections predict the decay rates of [12],…”