Higgs Portal Inflation

TL;DR

This paper explores a model where the Higgs field and a hidden sector singlet jointly act as the inflaton, linking early universe inflation with low-energy Higgs phenomenology and addressing unitarity concerns.

Contribution

It proposes a novel Higgs-portal inflation scenario involving a Higgs and hidden sector singlet, with detailed phenomenological and unitarity analysis.

Findings

Constraints on quartic couplings for inflation

Distinct Higgs signals at the LHC

Unitarity issues addressed and resolved

Abstract

The Higgs sector of the Standard Model offers a unique opportunity to probe the hidden sector. The Higgs squared operator is the only dimension two operator which is Lorentz and gauge invariant. It can therefore couple both to scalar curvature and the hidden sector at the dim--4 level. We consider the possibility that a combination of the Higgs and a singlet from the hidden sector plays the role of inflaton, due to their large couplings to gravity. This implies that the quartic couplings satisfy certain constraints which leads to distinct low energy phenomenology, including Higgs signals at the LHC. We also address the unitarity issues and show that our analysis survives the unitarization procedure.