The secondary vertex finding algorithm with the ATLAS detector

A high performance identification of jets, produced via fragmentation of bottom quarks, is crucial for the ATLAS experiment, running at the LHC. These jets can be identified by exploiting the presence of cascade decay vertices from bottom hadrons. A general vertex-finding algorithm is introduced and its application to the search for secondary vertices inside jets is described. Kinematic properties of the reconstructed vertices are used to construct several $b$-jet identification algorithms. The features and performance of the secondary vertex finding algorithm in a jet, as wellas the performance of the jet tagging algorithms, are studied using simulated$pp \rightarrow t\bar{t}$ events at a centre-of-mass energy of 13 TeV.