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

Abstract

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