Mass limit for the standard model Higgs boson with the full LEP I ALEPH data sample

Abstract The reaction e + e − → HZ ∗ is used to search for the standard model Higgs boson in the H ν ν and the Hl + l − channels. The data sample corresponds to about 4.5 million hadronic Z decays collected by the ALEPH experiment at LEP from 1989 to 1995 at centre-of-mass energies at and around the Z peak. Three candidate events are found in the H μ + μ − channel, in agreement with the expected background from the electroweak process e + e − l + l − q q . This search results in a 95% C.L. lower limit on the Higgs boson mass of 63.9 GeV/ c 2 .