Pair production of scalars at the ILC in the Higgs triplet model under the non-degenerate case

The new scalars (H ^±±, H ^±± and H/A) are the typical particles predicted by the Higgs Triplet Model (HTM) and the observation of these particles can be regarded as the direct evidence of the HTM. In this letter, we study three pair production processes of these scalars, i.e., $e^{+}{e}^{-}\to H^{++}{H}^{--}$, $e^{+}{e}^{-}\to H^{+}{H}^{-}$ and $e^{+}{e}^{-}\to HA$ under the non-degenerate case. The characteristic signals and relevant SM backgrounds are also discussed both in the positive scenario $(M_{H/A}>M_{H^{\pm }}>M_{H^{\pm \pm }})$ and in the negative scenario $(M_{H/A}<M_{H^{\pm }}<M_{H^{\pm \pm }})$. Our numerical results show that the enhancement of the production rates due to the cascade decays is moderate in the positive scenario but significant in the negative one. Due to the relatively small SM backgrounds, their possible signals might be detected via these processes at future ILC experiments. (letter)