A Multiple Final State Search for Pair-Produced Bottom-Type Vector-Like Quarks in CMS Run 2 Data

We describe the extension of previous searches for the production of a pair of bottom-type vector-like quarks (VLQs) to include semileptonic channels and an increased sensitivity to fully hadronic channels in data gathered by the CMS detector during the 13 TeV runs in 2016, 2017, and 2018 of the LHC at CERN. We study hypothesized events where each VLQ decays to a bottom quark and a Higgs/Z boson or to a top quark and a W boson. We consider the cases where each boson decays into two quarks, which are typically resolved as two jets but can be resolved as one jet when the boson has a high transverse momentum. In the case of the VLQ decay to tW, we consider events where the top quark is resolved as either one, two, or three jets. For decays of the VLQ pair to bHbZ and bZbZ we consider decays of the Z boson to two leptons of the same flavor and opposite charge. Using a χ² metric based on the reconstructed masses of the Higgs/Z/W bosons and top quark, and on jet-level b-quark tagging, significantly reduces background from Standard Model processes. We present the updated exclusion limits set from the combination of the fully-hadronic and dileptonic analyses run over 137 fb^-1 of integrated luminosity data collected by the CMS detector during Run II.