Search for a new scalar resonance decaying to a pair of Z bosons in proton-proton collisions at $\sqrt s$ = 13 TeV

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 CERN LHC in 2016, corresponding to an integrated luminosity of 35.9 $\text{fb}^{\text{-1}}$ at a center-of-mass energy of 13 TeV. Z boson pair decays are reconstructed using the $4\ell$, $2 \ell 2 \mathrm{q}$, and $2\ell2\nu$ final states, where $\ell\! = \mathrm{e}$ 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-to-background separation. Description of the interference between signal and background amplitudes for a resonance of an arbitrary width is included. No significant excess of events is observed and limits are set on the production cross section for a new scalar boson for a large range of masses and widths.