Single production of charged Higgs bosons at linear colliders

We discuss single charged Higgs boson production from $e^+e^-$ annihilation at next generation linear colliders. They can be important to study the phenomenology of charged Higgs bosons, especially when charged Higgs bosons are too heavy to be produced by the pair production mechanism. Cross sections for various single production processes are evaluated at the leading order. Our analysis shows that in some parameter regions the phenomenology of charged Higgs bosons can be explored even beyond the kinematic limit for pair production by using single production processes.