Precision simulations in Drell-Yan production processes

Abstract

Studies of the Drell-Yan process, pp → V + X with V a vector boson, have become an important tool to elucidate the fundamental structure of the Standard Model at particle colliders. The precise theoretical understanding of this process is thus paramount to the further success of programs at modern particle colliders. In this thesis, we present the implementation of a method to improve the electroweak accuracy in the description of these processes within the SHERPA framework. This is achieved by including the next-to-leading order electroweak corrections for the leptonic decays of the massive electroweak bosons, Z, W and Higgs, and the next-to-next-to-leading order QED corrections in the case of Z- and Higgs bosons within the framework of the Yennie, Frautschi and Suura resummation formalism. We find small but potentially observable effects on distributions.

Besides the improvement in the theoretical description, phenomenological studies can improve the understanding of the physics at particle colliders. In the second Part of this Thesis we consider b-tagged jets. We study a number of jet shape observables that show good discrimination between a “legitimate”, single b-jet and one originating from a gluon splitting, and further show that the combination of these observables already provides good efficiency in rejecting b-jets from gluon splittings.