Physics (Internal)

From direct top squark pair production to measurements of the top-Z coupling with the CMS Experiment

This event is part of the HEE Seminar Series.

Supersymmetry (SUSY) is among the most promising theories for physics beyond the standard model and predicts the existence of new elementary particles. In many SUSY scenarios the mass of the top squark, the supersymmetric partner of the top quark, is expected to be not much larger than the top quark mass. Therefore, top squarks could be produced at the LHC and are heavily searched for in the CMS and ATLAS collaborations. The production of a Z boson in association with a top quark pair is a large irreducible background for these searches. A precise measurement of its cross section is therefore of great importance to reduce systematic uncertainties. Additionally, the coupling of the top quark to the Z boson is sensitive to corrections from physics beyond the standard model and is therefore a promising probe of new physics. I will present the results of a search for top squarks in the dilepton channel and give a preview of the results of a differential ttZ cross section measurement, with a focus on the interpretation of the results in terms of a top quark effective field theory.