The measurement of the boosted ttZ process

This study delves into the boosted top-quark pair production in association with a Z boson (ttZ) process in the three-lepton channel. The performance of the next-generation fast simulation tool, AtlFast3 (AF3) , is compared with the comprehensive ATLAS full simulation (FS). A significant part of this research is dedicated to verifying the top-tagging efficiency of re-clustered jets (RC Jets) and determining their mass utilizing specific criteria and algorithms.