Searching for a Light (pseudo)Scalar via the Yukawa Process at the ILC

Yukawa production of a light scalar can be explored at a linear collider. Light (pseudo)scalar can exist in extended Higgs models and an interesting example is the light pseudoscalar in Type-X two Higgs doublet model. The model can explain the anomalous magnetic moment of muon at large $\tan \beta$. We show that the available parameter space in this model can be examined by the Yukawa process at 5$\sigma$ at the ILC.