Updated scalar sector constraints in Higgs triplet model

TL;DR

This paper refines constraints on the Higgs triplet model's scalar sector using unitarity, quantum effects, and experimental data, narrowing down viable parameter space after the Higgs discovery.

Contribution

It provides updated bounds on scalar masses and mixing angles in the Higgs triplet model based on recent experimental measurements and theoretical considerations.

Findings

Strong constraints on the CP-even mixing angle from unitarity.

Large quantum effects in $h\to\gamma\gamma$ can exclude parts of parameter space.

Updated bounds on nonstandard scalar masses from T-parameter and diphoton data.

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.