Mass limits of charged Higgs boson at large tan. beta. from e sup + e sup minus annihilations at radical s =50--60. 8 GeV

A search for the pair production of charged Higgs particles decaying via the {ital H}{sup {minus}}{r arrow}{tau}{bar {nu}} mode has been made in {ital e}{sup +}{ital e}{sup {minus}} annihilations at center-of-mass energies between 50 and 60.8 GeV using the AMY detector at the KEK collider TRISTAN. No evidence for their existence is observed and 95%-C.L. mass limits are presented. The result has been interpreted in terms of the tan{beta} parameter in the Higgs sector.