Light inflaton Hunter's Guide

TL;DR

This paper explores a light inflaton model that mixes with the Higgs boson, proposing experimental methods to detect it through meson decays and beam experiments, with specific mass and lifetime predictions.

Contribution

It presents a realistic light inflaton model with testable predictions and explores experimental detection strategies within particle physics.

Findings

Allowed inflaton mass range: 270 MeV to 1.8 GeV

Potential detection via kaon and B-meson decays

Inflaton lifetime estimated at 10^{-9} to 10^{-10} seconds

Abstract

We study the phenomenology of a realistic version of the chaotic inflationary model, which can be fully and directly explored in particle physics experiments. The inflaton mixes with the Standard Model Higgs boson via the scalar potential, and no additional scales above the electroweak scale are present in the model. The inflaton-to-Higgs coupling is responsible for both reheating in the Early Universe and the inflaton production in particle collisions. We find the allowed range of the light inflaton mass, 270 MeV<~m_chi<~1.8 GeV, and discuss the ways to find the inflaton. The most promising are two-body kaon and B-meson decays with branching ratios of orders 10^{-9} and 10^{-6}, respectively. The inflaton is unstable with the lifetime 10^{-9}--10^{-10} s. The inflaton decays can be searched for in a beam-target experiment, where, depending on the inflaton mass, from several billions to several tenths of millions inflatons can be produced per year with modern high-intensity beams.