Searches for neutral Higgs bosons in e+ e- collisions at LEP

A search for minimal standard model (MSM) and minimal supersymmetric model (MSSM), Higgs bosons with masses larger than 3 GeV/c2 has been performed by the OPAL collaboration one+e− data from LEP corresponding to an integrated luminosity of 1.24 pb−1. The limits for MSM Higgs bosons have been obtained using the channelsZ0→Z0*H0,Z0*→(v\(\bar v\) ore+e− or µ+, µ−. The search for MSSM Higgs bosons has been performed using the channelsZ0→Z0*H0,v\(\bar v\) ore+e− or µ+µ−),h0 →q\(\bar q\) andZ0→h0A0,h0A0→(4 jet orτ+τ−→ or 4τ), whereh0 andA0 are the two lightest neutral MSSM Higgs bosons. No Higgs boson signal has been observed. The MSM Higgs boson is excluded in the mass range 3 GeV <\(m_{H^0 }\)<25.3 GeV/c2 at the 95% confidence level; limits on the masses of the two lightest neutral MSSM Higgs bosons are obtained forh0 mases up to 40.5 GeV/c2.