Search for New Phenomena in Top-Antitop Quarks Final States with Additional Heavy-Flavour Jets with the ATLAS Detector

Description

This book reports on the search for a new heavy particle, the Vector-Like Top quark (VLT), in the Large Hadron Collider (LHC) at CERN. The signal process is the pair production of VLT decaying into a Higgs boson and top quark (TT→Ht+X, X=Ht, Wb, Zt). The signal events result in top–antitop quarks final states with additional heavy flavour jets. The book summarises the analysis of the data collected with the ATLAS detector in 2015 and 2016. In order to better differentiate between signals and backgrounds, exclusive taggers of top quark and Higgs boson were developed and optimised for VLT signals. These efforts improved the sensitivity by roughly 30%, compared to the previous analysis. The analysis outcomes yield the strongest constraints on parameter space in various BSM theoretical models. In addition, the book addresses detector operation and the evaluation of tracking performance. These efforts are essential to properly collecting dense events and improving the accuracy of the reconstructed objects that are used for particle identification. As such, they represent a valuable contribution to data analysis in extremely dense environments. Front Matter ....Pages i-xviii Introduction (Daiki Yamaguchi)....Pages 1-24 The ATLAS Experiment at the Large Hadron Collider (Daiki Yamaguchi)....Pages 25-51 Reconstruction of Physics Objects (Daiki Yamaguchi)....Pages 53-77 Data and Event Simulations (Daiki Yamaguchi)....Pages 79-83 Signal and Background Modeling (Daiki Yamaguchi)....Pages 85-131 Optimisations of Heavy Object Tagging and Event Categorisation (Daiki Yamaguchi)....Pages 133-174 Analysis Strategy (Daiki Yamaguchi)....Pages 175-197 Systematic Uncertainties (Daiki Yamaguchi)....Pages 199-208 Statistical Analysis (Daiki Yamaguchi)....Pages 209-215 Results (Daiki Yamaguchi)....Pages 217-255 Discussion (Daiki Yamaguchi)....Pages 257-269 Prospect (Daiki Yamaguchi)....Pages 271-276 Conclusion (Daiki Yamaguchi)....Pages 277-279