Search for a heavy scalar boson decaying into a pair of Z bosons in the $2\ell 2\nu$ final state

We present a generic search for a heavy scalar boson using $13~\mathrm{TeV}$ proton-proton collision data acquired by the CMS experiment in 2015. Events in the decay channel $H \rightarrow ZZ \rightarrow 2\ell 2\nu$ are selected from data corresponding to an integrated luminosity of $2.3~\mathrm{fb}^{-1}$. An analysis of the reconstructed transverse mass and missing transverse energy is performed in different event categories, and limits are set on the production cross section of a heavy scalar of variable width in the gluon-fusion and vector-boson fusion production modes. The limits are interpreted as constraints on the production of a heavy scalar in the electroweak singlet model. They are stronger than the Run 1 analysis results in the mass range around $1~\mathrm{TeV}$ and above. Constraints are also set in the $\tan \beta - m_H$ parameter space of specific Type-I and Type-II two-Higgs doublet models.