Search for vector-like quarks in events with two oppositely charged leptons and jets in proton-proton collisions at √s = 13 TeV
A. M. Sirunyan et al.
Paper International Journal with referee
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 s√=13TeV . The data sample was collected in 2016 and corresponds to an integrated luminosity of 35.9 fb−1 . Final states studied for TT¯¯¯¯ production include those where one of the T quarks decays via T→tZ and the other via T→bW , 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 B→bZ and the other B→tW , 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 T→tZ , and B→bZ , T and B quark mass values below 1280 and 1130 GeV , respectively, are excluded.
Eur. Phys. J. C 79 (2019) 364 https://dx.doi.org/10.1140/epjc/s10052-019-6855-8