Top-quark pair production at hadron colliders [Elektronische Ressource] / Valentin Ahrens

Top-Quark Pair Production atHadron CollidersDissertationzur Erlangung des Grades “Doktor der Naturwissenschaften”am Fachbereich Physik, Mathematik und Informatikder Johannes Gutenberg-Universit¨at in MainzValentin AhrensGeboren in MainzMainz, September 2011Tag der Promotion8 Dezember 2011GutachtertestAbstractIn this thesis we investigate several phenomenologically important properties of top-quarkpair production at hadron colliders. We calculate double differential cross sections in twodifferent kinematical setups, pair invariant-mass (PIM) and single-particle inclusive (1PI)kinematics. In pair invariant-mass kinematics we are able to present results for the doubledifferential cross section with respect to the invariant mass of the top-quark pair and thetop-quarkscattering angle. Workingin the threshold region, where the pairinvariant mass√M is close to the partonic center-of-mass energy sˆ, we are able to factorize the partoniccross section into different energyregions. We use renormalization-group(RG) methodstoresum large threshold logarithms to next-to-next-to-leading-logarithmic (NNLL) accuracy.On a technical level this is done using effective field theories, such as heavy-quark effectivetheory(HQET)andsoft-collineareffectivetheory(SCET).Thesametechniquesareappliedwhen working in 1PI kinematics, leading to a calculation of the double differential crosssection with respect to transverse-momentum p and the rapidity of the top quark.