  A search is performed for W' bosons decaying to a top and a bottom quark in
the all-hadronic final state, in proton-proton collisions at a center-of-mass
energy of 13 TeV. The analyzed data were collected by the CMS experiment
between 2016 and 2018 and correspond to an integrated luminosity of 137
fb$^{-1}$. Deep neural network algorithms are used to identify the jet
initiated by the bottom quark and the jet containing the decay products of the
top quark when the W boson from the top quark decays hadronically. No excess
above the estimated standard model background is observed. Upper limits on the
production cross sections of W' bosons decaying to a top and a bottom quark are
set. Both left- and right-handed W' bosons with masses below 3.4 TeV are
excluded at 95% confidence level, and the most stringent limits to date on W'
bosons decaying to a top and a bottom quark in the all-hadronic final state are
obtained.
