High precision simulations of electroweak physics with Sherpa

Abstract

One vital theoretical tool in the ever-improving description of particle physics is Monte Carlo event simulation. With the CERN LHC currently exploiting the highest energies in any human-made experiment, with unprecedented precision for a range of processes, very precise theoretical models are strongly motivated. This thesis introduces an implementation of Sudakov logarithms, which are a high-energy approximation to the exact NLO calculation of the electroweak quantum theory, within the Sherpa Monte Carlo framework. As well as this, it validates and applies the Sherpa + OpenLoops interface to a range of interesting electroweak processes at NLO in QCD. One key area of study in the electroweak sector is that of high multiplicities of weak bosons in the final state, which are motivated by the insight these studies could provide into the recently discovered 125 GeV particle, with properties consistent with the Standard Model Higgs boson. Furthermore, several electroweak processes are key backgrounds in searches for physics beyond the Standard Model. In addition, leading order results are presented for more complex electroweak processes for which such a high level of precision has not yet become necessary. The thesis is concluded with studies at a potential future 100 TeV proton-proton collider.