A SIMPLE APPROXIMATION OF THE ONE-LOOP CORRECTED CROSS-SECTION FOR E(-)-]W+W- AT LEP-2()E()

Using the SU(2) gauge coupling, g(W)+/- (M-W+/-(2)), at the high-energ y scale of MW+/-, defined by the (theoretical value of the) leptonic W -width, rather than using the low-energy value, defined via the Fermi coupling, G(mu), in the Born approximation, and supplementing with Cou lomb corrections and initial state radiation, errors with respect to t he exact one-loop results for the differential cross section of e(+)e( -) --> W+W- are below 1% at LEP 2 energies at all W+W- production angl es. A similar procedure is suggested to incorporate leading bosonic lo op effects into four-fermion production in the fermion-loop scheme. Th e resulting accuracy below 1% is sufficient for LEP 2 experiments. (C) 1997 Published by Elsevier Science B.V.