Search for the minimal standard model Higgs boson in e+e− collisions at LEP

Abstract A search for the minimal standard model Higgs boson (H 0 ) has been performed with data from e + e − collisions in the OPAL detector at LEP. The analysis is based on approximately 8 pb −1 of data taken at centre-of-mass energies between 88.2 and 95.0 GeV. The search concentrated on the reaction e + e − →( e + e − , μ + μ − , v v or τ + τ − ) H 0 , H 0 →( q q or τ + τ − ) for Higgs boson masses above 25 GeV/ c 2 . No Higgs boson candidates have been observed. The present study, combined with previous OPAL publications, excludes the existence of a standard model Higgs boson with mass in the range 3 m H 0 c 2 at the 95% confidence level.