Double Higgs production in the littlest Higgs Model with T-parity at high energy $e^{+}{e}^{-}$ Colliders

Abstract

In the framework of the littlest Higgs model with T-parity(LHT), we investigate the double Higgs production processes $e^{+}{e}^{-}\to ZHH$ and $e^{+}{e}^{-}\to \hat{I}½\bar{\hat{I}}½HH$ at high energy $e^{+}{e}^{-}$ colliders. We calculate the production cross sections and find that the relative correction at the center-of-mass energy $\sqrt{s}=500$ GeV can maximally reach $-30$ for the process $e^{+}{e}^{-}\to ZHH$ and $-16$ for the process $e^{+}{e}^{-}\to \hat{I}½\bar{\hat{I}}½HH$ 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 $e^{+}{e}^{-}\to ZHH\to l\bar{l}b\bar{b}b\bar{b}$ and $e^{+}{e}^{-}\to \hat{I}½\bar{\hat{I}}½HH\to \hat{I}½\bar{\hat{I}}½b\bar{b}b\bar{b}$ are studied and some distributions of the signal and background are displayed.