Xolisile Thusini will present the Department of Physics seminar with a talk entitled, "Characterising the sources of fake leptons from top quarks in same sign W boson scattering with the ATLAS detector at √s = 13 TeV". 

The Standard Model (SM) of particle physics is a well-tested theory that describes the properties of fundamental particles and the forces of nature at the smallest scale. It further explains the existence of the electroweak force as a spontaneously broken gauge symmetry, an important component in understanding the masses of particles and the behaviour of matter. Many analyses have been performed testing these theoretical predictions and it has led to the discovery of the Higgs boson with the ATLAS and CMS detector in 2012. This was a major achievement for science followed by a Nobel Prize in 2013. This discovery has begun to shed some light on the picture of electroweak symmetry breaking (EWSB) mechanism. However, it is also possible that there are other particles that play a role in the EWSB mechanism. The effect of these particles may be seen in the same proton-proton (pp) collisions at the LHC through the scattering of two massive vector-W bosons. This talk presents a study of background processes that contribute to the same sign WW production cross section in √s = 13 TeV p-p collision data collected by the ATLAS detector. The aim of the study is the investigation of observables that can be used to suppress background events in same sign WW processes by probing jets faking leptons in a Monte Carlo simulated sample of  events.