Heavy Light Inflaton and Dark Matter Production

TL;DR

This paper explores a minimal scalar extension of the Standard Model where the inflaton's mass range is expanded to include heavier values, and investigates how heavy neutral leptons can serve as dark matter candidates within this framework.

Contribution

It analyzes the previously overlooked scenario of heavier inflaton masses and introduces heavy neutral leptons as dark matter candidates in the model.

Findings

Viable inflaton mass window identified for masses above 250 GeV.

Heavy neutral leptons with MeV-scale masses can account for cold dark matter.

Inflaton-Higgs mixing remains small, evading observational constraints.

Abstract

We study the minimal extension of the SM by a scalar with quartic interaction serving as an inflaton. For the model where scale symmetry is broken only in the inflaton sector, the mass of the inflaton is constrained to be relatively low. Here, we analysed the previously omitted situation of the inflaton masses $m_{\chi}\gtrsim 250\text{ GeV}$. Therefore, we provide a window of inflaton masses with viable inflationary properties that evade direct observational constraints, due to their small mixing with the Higgs sector. The addition of heavy neutral leptons with Majorana masses induced by the interaction with the inflaton allow for Cold Dark Matter in the model with masses $O(1-10)\text{ MeV}$.