B-tagging optimisation studies in SUSY events with photons and missing energy at CMS

Simon Bohlen
Oct 2013

Thesis Type:

In this thesis studies are presented, which aim to improve the search of supersymmetric final states containing photons, jets and missing transverse energy. Simulated events of the CMS detector of proton-proton collisions at the LHC with a center-of-mass energy
$\sqrt{s} = 8$ TeV are used. The main idea is to improve the ratio of signal events over of background events by implementing b-tagging into the analysis. Monte-Carlo simulations are used to do general studies like b-tag efficiency and fake rate measurements as well as analyzing the change of the ratios of signal events to background events when requiring b-tags or applying a veto for b-tags. The studies have shown, that the requirement of a b-tag improves the ratio of the number of signal events to the number of background events for all studied signal samples by a factor of up to 3.5 if missing transverse energies of more than 200 GeV are required.