Double Higgs production in the littlest Higgs model with T-parity at high energy e+e- colliders

In the framework of the littlest Higgs model with T-parity (LHT), we investigate the double Higgs production processes e(+)e(-) -> ZHH and e(+)e(-) -> nu(nu) over bar HH at high energy e(+)e(-) colliders. We calculate the production cross sections and find that the relative correction at the center-of-mass energy root s = 500 GeV can maximally reach -30% for the process e(+)e(-). ZHH and -16% for the process e(+)e(-) -> nu(nu) over bar HH in the allowed parameter space, respectively. These large relative corrections can reach the detection range of the future e(+)e(-) colliders so that they can be used to test the LHT effect. The two relevant decay modes e(+)e(-). -> ZHH -> l (l) over barb (b) over barb (b) over bar and e(+)e(-) -> nu(nu) over bar HH nu(nu) over barb (b) over barb (b) over bar are studied and some distributions of the signal and background are displayed.