The Ultraviolet Landscape of Two-Higgs Doublet Models

TL;DR

This paper investigates the predictions of ultraviolet completions of two-Higgs doublet models, emphasizing the importance of radiative corrections and the relationship between high-scale couplings and low-scale scalar mass spectra.

Contribution

It provides a detailed analysis of how quartic couplings at the matching scale influence the scalar mass spectrum and stability in two-Higgs doublet models, including the effects of radiative corrections.

Findings

Radiative corrections are crucial for accurate Higgs mass predictions.

Small mass splittings are typical between heavy Higgs states.

A correlation exists between the size of couplings and the matching scale.

Abstract

We study the predictions of generic ultraviolet completions of two-Higgs doublet models. We assume that at the matching scale between the two-Higgs doublet model and a ultraviolet complete theory -- which can be anywhere between the TeV and the Planck scale -- arbitrary but perturbative values for the quartic couplings are present. We evaluate the couplings down from the matching scale to the weak scale and study the predictions for the scalar mass spectrum. In particular, we show the importance of radiative corrections which are essential for both an accurate Higgs mass calculation as well as determining the stability of the electroweak vacuum. We study the relation between the mass splitting of the heavy Higgs states and the size of the quartic couplings at the matching scale, finding that only a small class of models exhibit a sizeable mass splitting between the heavy scalars at the weak scale. Moreover, we find a clear correlation between the maximal size of the couplings and the considered matching scale.