  A search for electroweak production of a single vector-like T quark in
association with a bottom (b) quark in the all-hadronic decay channel is
presented. This search uses proton-proton collision data at $\sqrt{s}$ = 13 TeV
collected by the CMS experiment at the CERN LHC during 2016-2018, corresponding
to an integrated luminosity of 138 fb$^{-1}$ The T quark is assumed to have
charge 2/3 and decay to a top (t) quark and a Higgs (H) or Z boson. Event
kinematics and the presence of jets containing b hadrons are used to
reconstruct the hadronic decays of the t quark and H or Z boson. No significant
deviation from the standard model prediction is observed in the data. The 95%
confidence level upper limits on the product of the production cross section
and branching fraction of a T quark produced in association with a b quark and
decaying via tH or tZ range from 1260 to 68 fb for T quark masses of 600-1200
GeV.
