Searches for the Neutral Higgs Bosons of the MSSM: Preliminary Combined Results Using LEP Data Collected at Energies up to 209 GeV

Abstract

In the year 2000 the four LEP experiments collected data at centre-of-mass energies between 200 and 209 GeV, integrating approximately 870 pb-1 of luminosity, with about 510 pb-1 above 206 GeV. The LEP working group for Higgs boson searches has combined these data with data sets collected previously at lower energies. In representative scans of the parameters of the Minimal Supersymmetric Standard Model (MSSM), the mass limits mh>91.0 GeV and mA>91.9 GeV are obtained for the light CP-even and the CP-odd neutral Higgs boson, respectively. For a top quark mass less than or equal to 174.3 GeV, assuming that the stop quark mixing is maximal, and choosing conservative values for other SUSY parameters affecting the Higgs sector, the range 0.5<tanbeta<2.4 is excluded. Additionally, the results of flavour-independent searches for hadronically decaying Higgs bosons are included, allowing exclusion of MSSM models with suppressed decays of the Higgs bosons to pairs of b quarks.