The effects of the little Higgs models on $t\bar{t}{h}^0$ production via $\gamma \gamma$ collision at linear colliders

Abstract

In the frameworks of the littlest Higgs($LH$) model and its extension with T-parity($LHT$), we studied the associated $t\bar{t}{h}^0$ production process $e^{+}{e}^{-}\to \gamma \gamma \to t\bar{t}{h}^0$ at the future $e^{+}{e}^{-}$ linear colliders up to QCD next-to-leading order. We present the regions of $\sqrt{s}-f$ parameter space in which the $LH$ and $LHT$ effects can and cannot be discovered with the criteria assumed in this paper. The production rates of process $\gamma \gamma \to t\bar{t}{h}^0$ in different photon polarization collision modes are also discussed. We conclude that one could observe the effects contributed by the $LH$ or $LHT$ model on the cross section for the process $e^{+}{e}^{-}\to \gamma \gamma \to t\bar{t}{h}^0$ in a reasonable parameter space, or might put more stringent constraints on the $LH$/$LHT$ parameters in the future experiments at linear colliders.

Comments: 22 pages, 25 figures, version to appear in Phys. Rev. D