Gauge-invariant description of W-pair production in NLO approximation
Abstract
Description
The processes $e^{+}e^{-} \to 4f(γ)$ mediated by W-pair (and single) production are considered in the framework of the modified perturbation theory, based on the expansion of probability in powers of the coupling constant instead of amplitude. A full set of one-loop corrections to cross-section, and two-loop corrections to self-energy of unstable particles are completely taken into consideration. It is shown that the manifestly non-factorizable corrections do not make contributions into the next-to-leading-order approximation. Moreover, the colour reconnection does not make contributions within this precision, either. The rest of the corrections together with the leading-order contribution provide the gauge-invariant description of the processes.
7 pages, latex, 2 eps-figures. Talk presented at the Research Workshop "Calculations for Modern and Future Colliders" Dubna, July 2000, and at the XVth International Workshop "High Energy Physics and Quantum Field Theory", Tver, September 2000
7 pages, latex, 2 eps-figures. Talk presented at the Research Workshop "Calculations for Modern and Future Colliders" Dubna, July 2000, and at the XVth International Workshop "High Energy Physics and Quantum Field Theory", Tver, September 2000