European Laboratory for Particle Physics (cern) the Aleph Collaboration

Data collected at centre-of-mass energies of 181–184 GeV by ALEPH at LEP, corresponding to an integrated luminosity of 56.9 pb −1 , are analysed in a search for pair-produced charged Higgs bosons H ±. Three analyses are employed to select the τ + ν τ τ − ¯ ν τ , c¯ sτ − ¯ ν τ /¯ csτ + ν τ and c¯ ss¯ c final states. No evidence for a signal is found. Mass limits are set as a function of the branching fraction B(H + → τ + ν τ). Under the assumption that the decay modes considered cover the totality of the possible final states, charged Higgs bosons with masses below 59 GeV/c 2 are excluded at 95% C.L. independently of B(H + → τ + ν τ).