A search for the pair production of heavy vector-like partners T and B of the top and bottom quarks has been performed by the CMS experiment at the CERN LHC using proton-proton collisions at . The data sample was collected in 2016 and corresponds to an integrated luminosity of 35.9 production include those where one of the T quarks decays via TtZ and the other via TbW, tZ, or tH, where H is a Higgs boson. For the BB case, final states include those where one of the B quarks decays via BbZ and the other BtW, bZ, or bH. Events with two oppositely charged electrons or muons, consistent with coming from the decay of a Z boson, and jets are investigated. The number of observed events is consistent with standard model background estimations. Lower limits at 95% confidence level are placed on the masses of the T and B quarks for a range of branching fractions. Assuming 100% branching fractions for TtZ, and BbZ, T and B quark mass values below 1280 and 1130 respectively, are excluded.

Search for vector-like quarks in events with two oppositely charged leptons and jets in proton-proton collisions at root s=13TeV

Azzi, P.;Bisello, D.;Boletti, A.;Bragagnolo, A.;Carlin, R.;Checchia, P.;Dall'Osso, M.;Gasparini, F.;Gasparini, U.;Gozzelino, A.;Lacaprara, S.;Lujan, P.;Margoni, M.;Meneguzzo, A. T.;Pazzini, J.;Presilla, M.;Ronchese, P.;Rossin, R.;Simonetto, F.;Torassa, E.;Tosi, M.;Zanetti, M.;Zotto, P.;Zumerle, G.;Triossi, A.;Zucchetta, A.;