  A search is reported for a narrow vector resonance decaying to
quark-antiquark pairs in proton-proton collisions at sqrt(s) = 13 TeV,
collected with the CMS detector at the LHC. The data sample corresponds to an
integrated luminosity of 2.7 inverse femtobarns. The vector resonance is
produced at large transverse momenta, with its decay products merged into a
single jet. The resulting signature is a peak over background in the
distribution of the invariant mass of the jet. The results are interpreted in
the framework of a leptophobic vector resonance and no evidence is found for
such particles in the mass range of 100-300 GeV. Upper limits at 95% confidence
level on the production cross section are presented in a region of
mass-coupling phase space previously unexplored at the LHC. The region below
140 GeV has not been explored by any previous experiments.
