The Social Higgs

TL;DR

This paper investigates whether the Higgs boson might be mixed with other neutral scalars by analyzing search data, proposing models that could explain observed anomalies and fit the data better.

Contribution

It introduces two simple models of Higgs mixing with additional scalars, including one with enhanced photon coupling, and evaluates their compatibility with experimental data.

Findings

Enhanced diphoton rates can be accommodated by the 'accomplice' model.

Mixing angles greater than pi/4 are generally disfavored at 95% confidence.

Additional scalars near 210 GeV can improve the fit to the data.

Abstract

Using published Higgs search data we investigate whether any evidence supports the possibility that the Higgs may be mixed with other neutral scalars. We combine the positive evidence for the Higgs at 125.5 GeV with search constraints at other masses to explore the viability of two simple models. The first Higgs 'friend' model is simply a neutral scalar mixed with the Higgs. In the second Higgs 'accomplice' model the new scalar has an enhanced coupling to photons due to couplings to additional charged fields. We find that the latter scenario allows improvement in fitting the data by accommodating enhanced diphoton rates and suppression in other channels for a Higgs mass of 125.5 GeV. Small excesses at other masses allow the additional scalar to further improve the fit to the data, particularly if it has mass in the vicinity of 210 GeV. Due to observed event rates at 125.5 GeV and strong limits in high mass Higgs searches, mixing angles greater than pi/4 are typically disfavored at the 95% confidence level, depending on the mass of the scalar.