TH Meeting on Particle Physics Phenomenology

Two-loop renormalization of the electric charge in the standard model

Name: Two-loop renormalization of the electric charge in the standard model
Start: 2003-09-12T14:00:00+02:00
End: 2003-09-12T15:00:00+02:00
Location: CERN

by Alessandro Vicini (Università degli Studi di Milano)

Friday 12 Sept 2003, 14:00 → 15:00 Europe/Zurich

TH Auditorium (CERN)

TH Auditorium

CERN

Description

We discuss the renormalization of the electric charge at the two-loop level in the Standard Model of the electroweak interactions. We explicitly calculate the expression of the complete on-shell two-loop counterterm using the Background Field Method and discuss the advantages of this computational approach. We consider the related quantity ê(μ), defined in the MSbar renormalization scheme and present numerical results for different values of the scale μ. We find that the full two-loop electroweak corrections contribute more than 10 parts in units 10^-5 to the Δ \\hat{α} (\\mz^2) parameter, obtaining \\hat{α}^-1 (\\mz) = 128.12 ± 0.05 for Δ\\α_had (\\mz^2) = 0.027572 ± 0.000359. We briefly comment on the implications for the limits on the Higgs boson mass.