Search for charged Higgs bosons at LEP

Abstract A search for pair-produced charged Higgs bosons is performed with the L3 detector at LEP using data collected at centre-of-mass energies between 189 and 209 GeV, corresponding to an integrated luminosity of 629.4 pb −1 . Decays into a charm and a strange quark or into a tau lepton and its neutrino are considered. No significant excess is observed and lower limits on the mass of the charged Higgs boson are derived at the 95% confidence level. They vary from 76.5 to 82.7 GeV, as a function of the H ± → τν branching ratio.