Search for an Invisible Higgs Boson

This physics analysis summary describes a search for invisible decays of a Higgs boson produced via vector boson fusion. The search is performed using the full 8~\TeV dataset collected by CMS during 2012, with an integrated luminosity of 19.6~fb$^{-1}$. Events are selected with a dedicated trigger based on the vector boson fusion tag jet topology, together with large missing transverse energy. The offline selection makes further use of the tag jet topology. The dominant backgrounds from $\Z \rightarrow \nu \nu$ and $\W \rightarrow \ell \nu$ in which the charged lepton goes unidentified, and QCD multijet production, are estimated from observed data. Minor backgrounds are estimated from Monte-Carlo simulation. An upper limit on the invisible branching fraction of the 125 GeV boson is placed at 69\%, with an expected limit of 53\%.