2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/193047The littlest Higgs model with T-parity predicts the existence of the T-odd particles, which can only be produced in pair. We consider pair production of the T-odd leptons in future high energy linear $e^{+}e^{-}$ collider ($ILC$). Our numerical results show that, as long as the T-odd leptons are not too heavy, they can be copiously produced and their possible signals might be detected via the processes $e^{+}e^{-}\to \bar{L}_{i}L_{j}$ in future $ILC$ experiments.Discussions added, typos and references correctedHigh Energy Physics - PhenomenologyPair production of the heavy leptons in future high energy linear e^{+}e^{-} colliderstext