Left-right twin Higgs model confronted with the latest LHC Higgs data

Abstract

Motivated by the latest LHC Higgs data, we calculate the new physics contributions to the Higgs decay channels of $h\to \gamma\gamma, Z\gamma, \tau\tau, WW^*$ and $ ZZ^*$ in the left-right twin Higgs (LRTH) model, induced by the loops involving the heavy T-quark, the $W_H$ and $\phi^\pm$ bosons appeared in the LRTH model. We find that (a) for a SM-like Higgs boson around 125.5 GeV, the signal rates normalized to the corresponding standard model (SM) predictions are always suppressed when new physics contributions are taken into account and approach the SM predictions for a large scalar parameter $f$; and (b) the LRTH prediction for $R_{\gamma\gamma}$ agree well with the CMS measurement $R_{\gamma\gamma}=0.77\pm 0.27$ at $1\sigma$ level, but differ with the ATLAS result. The forthcoming precision measurement of the diphoton signal at the LHC can be a sensitive probe for the LRTH model.