Higgs boson decays and production in the left-right twin Higgs model

The left-right twin Higgs model predicts one neutral Higgs boson ϕ0 and it acquires mass mϕ0∼μr with the μ term, which can be lighter than half the SM-like Higgs boson mass in a portion of parameter space. Thus, the SM-like Higgs boson h can dominantly decay into a pair of light neutral Higgs bosons especially when mh is below the WW threshold. First, we examine the branching ratios of the SM-like Higgs boson decays and find that the new decay mode h→ϕ0ϕ0 is dominant for the case of mh>2mϕ0. Then we study the production via gluon fusion followed by the decay into two photons or two weak gauge bosons and found that the production rate can be significantly suppressed for some part of parameter space. Finally, we comparatively study the process γγ→h→bb¯ at ILC in the cases of mh>2mϕ0 and mh<2mϕ0, respectively. We find that these predictions can significantly deviated from the SM predictions, e.g., the gluon-gluon fusion channel, in the cases of mh>2mϕ0 and mh<2mϕ0, can be suppressed by about 80% and 45%, respectively. Therefor, it is possible to probe the left-right twin Higgs model via these Higgs boson production processes at the LHC experiment or in the future ILC experiment.