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

TL;DR

This paper reports a search for single vector-like T quarks decaying to tH or tZ in all-hadronic final states using 13 TeV proton-proton collision data, setting upper limits on production cross sections without observing deviations from the standard model.

Contribution

First search for electroweak single production of vector-like T quarks decaying to tH or tZ in all-hadronic final states at 13 TeV with CMS data.

Findings

No significant excess observed over standard model predictions.

Set upper limits on T quark production cross sections from 1260 to 68 fb.

Excluded T quark masses in the range 600-1200 GeV at 95% CL.

Abstract

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. 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.