Neutrino mass and missing momentum Higgs boson signals

In the simplest scheme for neutrino masses invoking a triplet of Higgs scalars there are two CP-even neutral Higgs bosons H-i (i=1,2) and one massive pseudoscalar A. For some choices of parameters, the lightest H-1 may be lighter than the standard model Higgs boson. If the smallness of the neutrino mass is due to the small value of the triplet expectation value, as expected in a seesaw scheme, the Higgs bosons may decay dominantly to the invisible neutrino channel. We derive limits on Higgs boson masses and couplings that follow from CERN LEP I precision measurements of the invisible Z width. [S0556-2821(98)01917-1].