Light inflaton after LHC8 and WMAP9 results

TL;DR

This paper updates the parameter space of a light inflaton model in light of recent cosmological and collider data, highlighting its potential experimental signatures and implications for dark matter production.

Contribution

It introduces a revised inflaton model compatible with recent observations, emphasizing the role of non-minimal gravity coupling and potential experimental detection methods.

Findings

Inflaton mass above 300 MeV compatible with data.

Possible detection via B-meson decays at B-factories.

Inflaton signatures include missing energy, displaced vertices, or resonance peaks.

Abstract

We update the allowed parameter space of the simple chaotic inflationary model with quartic potential and light inflaton [Bezrukov,Gorbunov'2009] taking into account recent results from cosmology (CMB observations from SPT, ACT and WMAP) and from particle physics (LHC hints of the SM Higgs boson). The non-minimal (yet small) coupling to gravity of the inflaton becomes essential to fit the observational data. The inflaton has mass above 300 MeV and can be searched for at B-factories in B-meson two-body decays to kaon and inflaton. The inflaton lifetime depends on the model parameters, resulting in various inflaton signatures: either a missing energy, or a displaced vertex from the B-meson decay position, or a resonance in the Dalitz plot of a three particle decay. We also discuss the implementation of the inflaton model to the nuMSM, where the inflaton can be responsible for production of the dark matter sterile neutrino in the early Universe.