Single Higgs boson production at the ILC in the left-right twin Higgs model

Abstract

In this work, we analyze three dominant single SM-like Higgs boson production processes in the left-right twin Higgs model (LRTHM): the Higgs-strahlung (HS) process $e^{+}e^{-}\rightarrow Zh$, the vector boson fusion (VBF) process $e^{+}e^{-}\to \nu\bar{\nu}h$ and the associate production with top pair process $e^{+}e^{-}\to t\bar{t}h$ for three possible energy stages of the International Linear Collider (ILC), and compared our results with the expected experimental accuracies for various accessible Higgs decay channels. The following observations have been obtained: (i) In the reasonable parameter space, the LRTHM can generate moderate contributions to theses processes with polarized beams; (ii) Among various Higgs boson decay channels, the $b\bar{b}$ signal strength is most sensitive to the LRTHM due to the high expected precision. For the $t\bar{t}h$ production process, the absolute value of $\mu_{b\bar{b}}$ may deviate from the SM prediction by over $8.7\%$ and thus may be detectable at the future ILC with $\sqrt{s}=1$ TeV; (iii) The future ILC experiments may give strong limit on the scale parameter $f$: for the case of ILC-250 GeV, for example, the lower limit for parameter $f$ of the LRTHM is $f > 1150$ GeV at the $2\sigma$ level.