Distinguishing signatures of top- and bottom-type heavy vectorlike quarks at the LHC

Abstract

An SU(2) vectorlike singlet quark with a charge of either +2/3(t′) or −1/3(b′) is predicted in many extensions of the Standard Model. The mixing of these quarks with the top or bottom lead to flavor-changing Yukawa interactions and neutral currents. The decay modes of the heavier mass eigenstates are therefore different from the Standard Model-type chiral quarks. The LHC will provide an ideal environment to look for the signals of these exotic quarks. Considering all decays, including those involving Z and Yukawa interactions, we show how one can distinguish between t′ and b′ from ratios of event rates with different lepton multiplicities. The ability to reconstruct the Higgs boson with a mass around 125.5 GeV plays an important role in such differentiation.