$\mu$) channel were previously reported by the ATLAS Collaboration using a data sample of proton-proton ($\Pp\Pp$) collisions at a centre-of-mass energy of $13\TeV$, corresponding to an integrated luminosity of 36.1 [@Aaboud:2018fhh]. The observed (expected) exclusion limit on the signal strength $\mu$ (defined as the product of the measured boson production cross section and the $\PH \to \ccbar$ branching fraction divided by the same quantity as predicted by the SM) at 95% CL was found to be 110 (150).

This paper presents the first direct search for the [$\PH\to\ccbar$]{}decay carried out by the CMS Collaboration. It uses $\Pp\Pp$ collision data corresponding to an integrated luminosity of 35.9, collected with the CMS experiment at the LHC in 2016 at a centre-of-mass energy of 13. The search targets bosons produced in association with a  or  boson, which we collectively refer to as vector () bosons. The presence of a boson greatly suppresses backgrounds stemming from otherwise overwhelming QCD multijet processes, and its leptonic decays provide a crucial handle to collect the events efficiently. The most significant remaining backgrounds arise from +jets (processes that account for one or more jets recoiling against a vector boson), , and [$\PV\PH(\PH\to \cPqb \cPaqb)$]{}processes. To fully explore the 