Searching for charged Higgs bosons at ∼(1/2–1-TeVe+e−colliders

Possibilities for charged-Higgs-boson searches at ∼1/2–1-TeV $e^{+}$ $e^{\mathrm{-}}$ colliders are examined. With an integrated luminosity of ∼${10}^{40}$ ${\mathrm{cm}}^{\mathrm{-}2}$, it is not difficult to find charged-Higgs-boson pair production if the beam energy is not too close to the charged-Higgs-boson mass. Experimental searches for all the major possible decay modes of charged Higgs bosons, i.e., $H^{+}$→tb¯, $H^{+}$→cs¯ (or cb¯), $H^{+}$→${\tau }^{+}$ ${\nu }_{\tau }$, and $H^{+}$→$W^{+}$ $H_i^0$, where $H_i^0$ is one of the neutral Higgs bosons, are surveyed in this paper. Searches for charged Higgs bosons in top-quark decays are also discussed. At $e^{+}$ $e^{\mathrm{-}}$ colliders the background level is low and well controlled compared to searches at hadron colliders (Superconducting Super Collider or CERN Large Hadron Collider). At hadron colliders, except in some very special cases, it is difficult to find charged Higgs bosons.