Searching for invisibly decaying Higgs bosons at CERN LEP II

We study the potential of CERN LEP II to unravel the existence of invisibly decaying Higgs bosons, predicted in a wide class of models. We perform a model-independent analysis, focusing our attention on the final state topologies exhibiting $b\overline{b}$ or ${\mathcal{l}}^{+}{\mathcal{l}}^{-}$ $(\mathcal{l}=\mu$ or $e)$ pairs and missing energy. We carefully evaluate the signals and backgrounds, choosing appropriate cuts to enhance the discovery limits. Our results demonstrate that LEP II is capable of discovering such a Higgs boson for a wide range of masses and couplings.