Search for Neutral MSSM Higgs Bosons at LEP

The four LEP collaborations, ALEPH, DELPHI, L3 and OPAL, have searched for neutral Higgs bosons which are predicted within the framework of the Minimal Supersymmetric Model (MSSM). The data of the four collaborations are statistically combined and examined for their consistency with the background hypothesis and for a possible Higgs boson signal. The com­ bined LEP data show no significant excess of events which would indicate the production of Higgs bosons. The search results are thus used to set upper bounds on the cross sections of various Higgs­like event topologies. The results are interpreted within the MSSM for a number of ``benchmark'' models, including CP­conserving and CP­violating scenarios. In all cases these interpretations lead to large exclusions in the theoretical MSSM parameter space. In some sce­ narios absolute limits are set on the masses of neutral Higgs bosons.