Are There Hints of Light Stops in Recent Higgs Search Results?

TL;DR

This paper analyzes Higgs search results from the LHC and Tevatron, suggesting that a light, highly mixed stop could explain deviations from Standard Model predictions in Higgs couplings and widths.

Contribution

It proposes that a light, highly mixed stop could modify Higgs decay widths, providing a potential new physics explanation for observed anomalies.

Findings

Data favor a Higgs with suppressed gluon-gluon width

Enhanced gamma gamma width observed in fits

A light, highly mixed stop can account for these modifications

Abstract

The recent discovery at the LHC by the CMS and ATLAS collaborations of the Higgs boson presents, at long last, direct probes of the mechanism for electroweak symmetry breaking. While it is clear from the observations that the new particle plays some role in this process, it is not yet apparent whether the couplings and widths of the observed particle match those predicted by the Standard Model. In this paper, we perform a global fit of the Higgs results from the LHC and Tevatron. While these results could be subject to as-yet-unknown systematics, we find that the data are significantly better fit by a Higgs with a suppressed width to gluon-gluon and an enhanced width to gamma gamma, relative to the predictions of the Standard Model. After considering a variety of new physics scenarios which could potenially modify these widths, we find that the most promising possibility is the addition of a new colored, charged particle, with a large coupling to the Higgs. Of particular interest is a light, and highly mixed, stop, which we show can provide the required alterations to the combination of gg and gamma gamma widths.