Search for vector-like quarks in events with two oppositely charged leptons and jets in proton-proton collisions at

A search for the pair production of heavy vector-like partners $$ and $$ of the top and bottom quarks has been performed by the CMS experiment at the CERN LHC using proton-proton collisions at $$ . The data sample was collected in 2016 and corresponds to an integrated luminosity of 35.9 $$ . Final states studied for $$ production include those where one of the $$ quarks decays via $$ and the other via $$ , $$ , or $$ , where $$ is a Higgs boson. For the $$ case, final states include those where one of the $$ quarks decays via $$ and the other $$ , $$ , or $$ . Events with two oppositely charged electrons or muons, consistent with coming from the decay of a $$ 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 $$ and $$ quarks for a range of branching fractions. Assuming 100% branching fractions for $$ , and $$ , $$ and $$ quark mass values below 1280 and 1130 $$ , respectively, are excluded.