  A search for a new scalar resonance decaying to a pair of Z bosons is
performed in the mass range from 130 GeV to 3 TeV, and for various width
scenarios. The analysis is based on proton-proton collisions recorded by the
CMS experiment at the LHC in 2016, corresponding to an integrated luminosity of
35.9 fb$^{-1}$ at a center-of-mass energy of 13 TeV. The Z boson pair decays
are reconstructed using the 4$\ell$, 2$\ell$2q, and 2$\ell$2$\nu$ final states,
where $\ell =$ e or $\mu$. Both gluon fusion and electroweak production of the
scalar resonance are considered, with a free parameter describing their
relative cross sections. A dedicated categorization of events, based on the
kinematic properties of associated jets, and matrix element techniques are
employed for an optimal signal and background separation. A description of the
interference between signal and background amplitudes for a resonance of an
arbitrary width is included. No significant excess of events with respect to
the standard model expectation is observed and limits are set on the product of
the cross section for a new scalar boson and the branching fraction for its
decay to ZZ for a large range of masses and widths.
