Update of Global Two-Higgs-Doublet Model Fits

TL;DR

This paper presents the latest global fits of Two-Higgs-Doublet models incorporating recent LHC data, setting stringent limits on model parameters, Higgs mass splittings, and decay widths, thus refining the understanding of these models.

Contribution

It provides the most recent combined experimental and theoretical constraints on Two-Higgs-Doublet models using LHC data, improving parameter bounds and mass splitting limits.

Findings

Deviations from the alignment limit are very small, less than 0.03 in type I and 0.02 in others.

Lower bounds on heavy Higgs masses are established in the global fit.

Heavy Higgs decay widths are constrained to be less than 7% of their masses for particles lighter than 1.5 TeV.

Abstract

We perform global fits of Two-Higgs-Doublet models with a softly broken $\mathbb{Z}_2$ symmetry to recent results from the LHC detectors CMS and ATLAS, that is signal strengths and direct search limits obtained at $\sqrt{s} = 8$ TeV and $\sqrt{s}=13$ TeV. We combine all available ATLAS and CMS constraints with the other relevant theoretical and experimental bounds and present the latest limits on the model parameters. We obtain that deviations from the so-called alignment limit $\beta-\alpha=\pi/2$ cannot be larger than $0.03$ in type I and have to be smaller than $0.02$ in the remaining three types. For the latter, we also observe lower limits on the heavy Higgs masses in the global fit. The splittings between these masses cannot exceed $200$ GeV in the types I and X and $130$ GeV in the types II and Y. Finally, we find that the decay widths of the heavy Higgs particles cannot be larger than $7\%$ of their masses if they are lighter than $1.5$ TeV.