Production of extra quarks at the Large Hadron Collider beyond the narrow width approximation

This paper explores the effects of both finite width and interference (with background) in the pair production and decay of extra heavy quarks with charge $2/3$ at the LHC. This dynamics is normally ignored in standard experimental searches and we assess herein the regions of validity of current approaches, also evaluating the performances of a set of current experimental analyses at 8 and 13 TeV for the determination of the excluded regions in the (MVLQ,ΓVLQ) plane, with MVLQ being the mass of the vector-like quark and ΓVLQ its width. Further, we discuss the configurations of masses, widths and couplings where the latter breaks down.