Improving sensitivity of vectorlike top partner searches with jet substructure

Vectorlike quark partners appear in many models beyond the Standard Model and remain an important area of research, as they can offer insights into the electroweak symmetry breaking mechanism. In this work, we have focused on studying the production of a heavy vectorlike top partner in association with a Standard Model top quark via chromomagnetic coupling and the four decay modes of the top partner, namely, bW, tZ, th, and tg. The signal has been studied in final states with one fat jet, at least one b-tagged jet, one lepton, and missing energy. This study focuses on the extensive use of jet substructure techniques in jets clustered with fixed and dynamically varying radius to deal with events containing differently sized jets. Important kinematic information, along with jet substructure and event shape observables, has been used in a multivariate analysis to extract signals with high significance. A comparative study between fixed and dynamically varying radius clustering of jets is also presented, leading to an improvement in signal sensitivity in the highly boosted scenario.