Aspects of Higgs Boson Searches at LEP2

Abstract

A preliminary combined mass limit of about 90 GeV has been reported for the Minimal Standard Model Higgs boson from the 183 GeV data taken in 1997, with a total luminosity of about 200 pb-1. Similar mass limits have been reported from the individual LEP experiments based on the first 1998 data at 189 GeV with up to 40 pb-1 each. For the first time the LEP experiments have made a common effort to derive preliminary combined limits in the Minimal Supersymmetric extension of the Standard Model. For three MSSM benchmark parameter sets, mass limits for the lighter scalar of 77 GeV and for the pseudoscalar of 78 GeV have been derived. In a more general parameter scan unexcluded mass regions have been revealed. An independent variation of the SUSY parameters results in cancellation effects of production cross sections and thus some parameter regions are not excluded in this more general framework. Direct and indirect limits from other SUSY particle searches have been taken into account.