LEP 1 Heavy Flavour Electroweak Physics and 2-Fermion Processes at LEP 2

Abstract

Results from heavy flavour electroweak physics at LEP1 are reviewed together with measurements of 2-fermion processes at LEP2. For the former measurements the emphasis is on analyses of heavy quark forward-backward asymmetries, A_FB^b,c, and on the partial decay widths of the Z^0 to heavy quarks, R_b,c. The measurements of the heavy quark asymmetries are used to extract the effective electroweak mixing angle for leptons, sin^2(theta_eff^lept). A 2.9 sigma discrepancy between measurements of this quantity from A_l^SLD and from A_FB^b is observed. The 2-fermion processes at LEP2 are used to place stringent limits on physics processes beyond the Standard Model. However, all measured quantities are in reasonable agreement with the Standard Model expectations, and all calculated limits are well above the highest LEP2 center-of-mass energies.