Search for new phenomena in processes with top quark

Top quark is the heaviest known elementary particle. It is natural to expect that effects of new forces beyond the Standard Model strongly depend on the mass of interacting particles. Therefore, the study of processes with top quark offers an excellent opportunity of searching for new physics. The project of Emma Marshall will exploit this possibility. She will test one of the fundamental axioms of the Standard Model, lepton flavour universality, using the decays of the top quark. The first measurement recently performed by ATLAS demonstrated that this test at the LHC could achieve a high precision. The task of Emma will include performing the measurement in a new channel of top-quark decay and improving the precision of the previous measurement.