Search for neutral Higgs bosons of the Minimal Supersymmetric Standard Model in e+e−interactions at s= 189GeV

Abstract A search for the lightest neutral scalar and neutral pseudoscalar Higgs bosonsin the Minimal Supersymmetric Standard Modelis performed using 176.4 pb −1 of integrated luminosity collected by L3 at a center-of- massenergy of 189 GeV . No signal is observed, and the data are consistent with the expected Standard Modelbackground. Lower limits on the masses of the lightest neutral scalar and pseudoscalar Higgs bosonsare given as a function of tan β . Lower mass limits for tan β >1 are set at the 95% confidence level to be m h >77.1 GeV and m A >77.1 GeV .