  A search is presented for narrow heavy resonances decaying to a top quark and
a bottom quark using data collected by the CMS experiment at sqrt(s) = 13 TeV
in 2016. The data set analyzed corresponds to an integrated luminosity of 35.9
inverse femtobarns. Final states that include a single lepton (e, mu), multiple
jets, and missing transverse momentum are analyzed. No evidence is found for
the production of a W' boson, and the production of right-handed W' bosons is
excluded at 95% confidence level for masses up to 3.6 TeV depending on the
scenario considered. Exclusion limits for W' bosons are also presented as a
function of their coupling strength to left- and right-handed fermions. These
limits on a W' boson decaying via a top and a bottom quark are the most
stringent published to date.
