Detecting invisible Higgs bosons at the CERN Large Hadron Collider

In some extensions of the standard model the (lightest) Higgs boson can have mainly invisible decays, decaying to a pair of the lightest supersymmetric partners, or to Goldstone bosons, or to Majorons, none of which interact in the detector. Thus it is not clear how such a Higgs boson can be detected. We show that associated production of such Higgs bosons with Z's at high-luminosity hadron colliders can provide a detectable signal for the mass region of most interest, Mₕ{≤}150 GeV. If a Higgs boson is detected another way, so that Mₕ is known, this method may allow a measurement of the branching ratio (B) (h{→}invisible), and may also allow measurement of other branching ratios.