Identifying top partners at LHC

Abstract

We systematically study the possible signals at LHC of new vector-like quarks mainly coupled to the third generation. We consider heavy quarks T, B, X, Y of charges 2/3, -1/3, 5/3 and -4/3, respectively, in SU(2)L isosinglets TL,R, BL,R, or isodoublets TBL,R, XTL,R or BYL,R. Analyses based on a fast detector simulation are presented for twelve different final states containing one, two, three or four charged leptons in several invariant mass regions, also considering various b quark multiplicities. It is shown that with the combination of the different channels the new quarks can be identified and their charged and neutral decays established. The comparison among final states also shows that the single lepton one offers the best discovery potential at LHC. For heavy quark masses of 500 GeV, the 5σ discovery luminosities range from 0.16 fb−1 for a XTL,R doublet to 1.9 fb−1 for a BL,R singlet.