Nuclear Seminar - Michal Dubovský (10.11.2021)
Wednesday 10.11.2021 at 14:00, Lecture rook F1/364 (online too)
Od: Jaroslav Staníček
Mgr. Michal Dubovský, PhD.:
Study of the associated production of the top-quark pair and Z boson at the ATLAS experiment with the full Run II dataset
Reaching center of mass energy to 13 TeV by LHC in 2015 and collecting the total integrated luminosity of 139/fb by the ATLAS experiment at this energy allowed us to measure and observe processes, which had been out of the experimental reach before. The associated production of the top-quark pair and the Z boson, shortly ttZ, is one of such processes. It is a rare process predicted by the Standard Model, with cross-section value of 0.863 pb, calculated at NLO+NNLL precision. This process was observed for the first time (with significance over 5 sigma) by the CMS experiment in data from 2015 and 2016. The ATLAS collaboration later published similar measurement, using data from the same period of data taking. In 2021, the ATLAS collaboration published the first ttZ cross section measurement using the full Run II data (2015-2018), measuring also differential cross section of this process. The talk will be focused on these two last measurements published by the ATLAS collaboration.