Littlest Higgs model and top-charm production at high-energy linear colliders

Due to the presence of extra top quark T in the little Higgs models, the CKM matrix is not unitary and the flavor changing neutral currents may exist at the tree level. In the context of the littlest Higgs (LH) model, we discuss the top-charm production at the high-energy linear e(+)e(-) collider (LC) via the processes e(+)e(-)->(t) over barc + t (c) over bar, e(+)e(-) -> ((t) over barc + t (c) over bar )v(e)(v) over bar (e), and e(-)gamma -> e(-)(t) over barc. We find that the resonance production cross section for the process e(+)e(-)->(t) over barc + t (c) over bar is significantly larger, which can be detected in the future LC experiments. (c) 2005 Elsevier B.V. All rights reserved.