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This paper is a slightly modified version of the introductory part of a doctoral dissertation also containing the articles hep-ph/0311268, hep-ph/0510375, hep-ph/0512177 and hep-ph/0701250. The thesis discusses effective field theory methods, in particular dimensional reduction, in the context of finite temperature field theory. We first briefly review the formalism of thermal field theory and show how dimensional reduction emerges as the high-temperature limit for static quantities. Then we apply dimensional reduction to two distinct problems, the pressure of electroweak theory and the screening masses of mesonic operators in hot QCD, and point out the similarities. We summarize the results and discuss their validity, while leaving all details to original research articles.
We review the current state-of-the-art in integrand level reduction for five-point scattering amplitudes at two loops in QCD. We present some benchmark results for the evaluation of the leading colour two-loop five-gluon amplitudes in the physical re
Various thermodynamic quantities for baryon-free matter are calculated by combining the most reliable non-perturbative and perturbative calculations, especially the most recent ones including as many quark flavors as possible. We extend these calcula
We discuss the difference between n-dimensional regularization and n-dimensional reduction for processes in QCD which have an additional mass scale. Examples are heavy flavour production in hadron-hadron collisions or on-shell photon-hadron collision
The relevance of single-W and single-Z production processes at hadron colliders is well known: in the present paper the status of theoretical calculations of Drell-Yan processes is summarized and some results on the combination of electroweak and QCD
Nonperturbative QCD corrections are important to many low-energy electroweak observables, for example the muon magnetic moment. However, hadronic corrections also play a significant role at much higher energies due to their impact on the running of s