Abstract:
The top quark is the heaviest elementary particle observed in nature and plays a unique role in the Standard Model of particle physics due to its large coupling to the Higgs boson.
Top quarks are mainly produced at hadron colliders through the strong interactions in association with their own antiparticle. The production process of top quark pairs is one of the most important reactions in particle physics and it has been measured very precisely at the LHC. However, experimental analyses rely heavily on fully exclusive simulations provided by Monte Carlo event generators.
The main goal of the thesis is to calculate a set of Feynman diagrams which involve soft gluon emission corrections that are relevant both for the top-antitopquark pair production process and the associated production of a Higgs boson with a top-anitopquark pair at the Large Hadron Collider. The project will employ computational techniques from Soft-Collinear Effective Theory (SCET) and also numerical integration methods. The evaluation of these contributions will be fundamental for a future implementation of a precise Monte Carlo event generator for processes involving top-anitopquark pairs which use N-jettiness as a jet resolution variable.