Generalization of exotic quark searches

General limits on exotic heavy quarks T, B, and X with masses above 300 GeV are presented for arbitrary branching fractions of T→W+b, T→Zt, T→Ht, B→W-t, B→Zb, B→Hb, and X→W+t. The results are based on a CMS search in final states with three isolated leptons (e or μ) or two isolated leptons with the same electric charge. Exotic heavy quark pair production through the strong interaction is considered. In the context of vectorlike quark models, T quarks with a mass mT<480 GeV and mT<550 GeV are excluded for weak isospin singlets and doublets, respectively, and B quarks with a mass mB<480 GeV are excluded for singlets, all at a 95% confidence level. Mass limits at the 95% confidence level for T and B singlets, (T,B) doublets, and (X,T) doublets are presented as a function of the corresponding heavy quark masses. For equal mass mT=mB and mX=mT, vectorlike quarks are excluded at the 95% confidence level with masses below 550 GeV for T and B singlets, 640 GeV for a (T,B) doublet, and 640 GeV for a (X,T) doublet.