Low Scale Inflation at High Energy Colliders and Meson Factories

TL;DR

This paper explores the possibility of detecting low scale inflation through collider and meson factory experiments by measuring the inflaton mass and its couplings, linking cosmological models with particle physics experiments.

Contribution

It demonstrates that low scale inflation models can be tested via Higgs portal couplings at colliders, connecting inflationary physics with measurable particle spectra.

Findings

Low scale inflatons can have large couplings to Standard Model particles.

Inflaton and curvaton masses are predictably related.

Collider experiments can probe inflationary models at GeV--PeV energies.

Abstract

Inflation occurring at energy densities less than (10$^{14}$ GeV)$^4$ produces tensor perturbations too small to be measured by cosmological surveys. However, we show that it is possible to probe low scale inflation by measuring the mass of the inflaton at low energy experiments. Detection prospects and cosmological constraints are determined for low scale quartic hilltop models of inflation paired with a curvaton field, which imprints the spectrum of scalar perturbations observed in large scale structure and on the cosmic microwave background. With cosmological constraints applied, low scale quartic inflation at energies GeV--PeV, can be mapped to an MeV--TeV mass inflaton resonance, discoverable through a Higgs portal coupling at upcoming collider and meson decay experiments. It is demonstrated that low scale inflatons can have detectably large couplings to Standard Model particles through a Higgs portal, permitting prompt reheating after inflation, without spoiling, through radiative corrections to the inflaton's self-coupling, the necessary flatness of a low scale inflationary potential. A characteristic particle spectrum for a quartic inflaton-curvaton pair is identified: to within an order of magnitude, the mass of the curvaton can be predicted from the mass of the inflaton, and vice-versa. Low scale inflation Higgs portal sensitivity targets are found for experiments like the LHC, SHiP, BEPC, and KEKB.