One-loop renormalized Higgs vertices in Georgi-Machacek model

TL;DR

This paper calculates one-loop level renormalized Higgs vertices in the Georgi-Machacek model, analyzing gauge dependence and potential deviations from Standard Model predictions under various theoretical and experimental constraints.

Contribution

It provides the first detailed computation of one-loop renormalized Higgs vertices in the Georgi-Machacek model, including gauge dependence analysis and deviation estimates.

Findings

Gauge dependence can be removed using the pinch technique.

Possible deviations in Higgs couplings are constrained by unitarity, stability, and experimental data.

Explicit one-loop corrections to Higgs vertices are provided.

Abstract

We compute renormalized vertices of the 125 GeV Higgs boson $h$ with the weak gauge bosons ($hVV$), fermions ($hf\bar{f}$) and itself ($hhh$) in the Georgi-Machacek model at one-loop level. The renormalization is performed based on the on-shell scheme with the use of the minimal subtraction scheme only for the $hhh$ vertex. We explicitly show the gauge dependence in the counterterms of the scalar mixing parameters in the general $R_\xi$ gauge, and that the dependence can be removed by using the pinch technique in physical scattering processes. We then discuss the possible allowed deviations in these one-loop corrected Higgs couplings from the standard model predictions by scanning model parameters under the constraints of perturbative unitarity and vacuum stability as well as those from experimental data.