ALEPH
PUBLISHED
BEYOND SM
Search for charged Higgs bosons in collisions at centre-of-mass energies from 130 to 172 GeV
The data collected at centre-of-mass energies ranging from 130 to 172 GeV by ALEPH at LEP, corresponding to an integrated luminosity of 27.5 pb-1, are analysed in a search for pair-produced charged Higgs bosons H+-. Three analyses are employed to select the tau nu tau nu, tau nu c s and c s c s final states. No evidence for a signal is found. Mass limits are set as a function of the branching fraction BR for H+- -> tau nu. Charged Higgs bosons with masses below 52 GeV are excluded at 95% C.L. independently of BR, thus significantly improving on existing mass limits from LEP1 searches.