A Search for neutral Higgs particles in Z0 decays

The search in DELPHI data for neutral Higgs bosons is described. No candidate for the Standard Model Higgs is seen in Z 0 decays to H 0 ν ν , H 0 μ + μ − or H 0 τ + τ − after selections that proved efficient for finding simulated H 0 . One remaining candidate for Z 0 → H 0 e + e − is consistent with background. Together with our earlier studies, these results restrict the H 0 mass to be above 38 GeV/ c 2 at the 95% confidence level. No signal is found for decays of Minimal Supersymmetric Standard Model neutral Higgs bosons to τ + τ − . Limits are obtained for their decays to produce four jets.