Updated scalar sector constraints in the Higgs triplet model

Abstract

We show that in the Higgs triplet model, after the Higgs discovery, the mixing angle in the CP-even sector can be strongly constrained from unitarity. We also discuss how large quantum effects in $h\to\gamma\gamma$ may arise in a SM-like scenario and a certain part of the parameter space can be ruled out from the diphoton signal strength. Using $T$-parameter and diphoton signal strength measurements, we update the bounds on the nonstandard scalar masses.