Search for production of a single vectorlike quark decaying to $tH$ or $tZ$ in the all-hadronic final state in $pp$ collisions at $\sqrt{s}=13\text{}\text{}\mathrm{TeV}$

A search for electroweak production of a single vectorlike $T$ quark in association with a bottom ($b$) quark in the all-hadronic decay channel is presented. This search uses proton-proton collision data at $\sqrt{s}=13\text{}\text{}\mathrm{TeV}$ collected by the CMS experiment at the CERN LHC during 2016–2018, corresponding to an integrated luminosity of $138\text{}\text{}{\mathrm{fb}}^{-1}$. The $T$ quark is assumed to have charge $2/3$ and decay to a top ($t$) quark and a Higgs ($H$) or $Z$ boson. Hadronic decays of the $t$ quark and the $H$ or $Z$ boson are reconstructed from the kinematic properties of jets, including those containing $b$ hadrons. No deviation from the standard model prediction is observed in the reconstructed $tH$ and $tZ$ invariant mass distributions. 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.