A Next-to-Minimal model of Hybrid Inflation in Effective Supergravity Theories

TL;DR

This paper introduces a hybrid inflation model within an effective supergravity framework based on a variant of the NMSSM, addressing key issues like the $mbda$ problem and the strong CP problem while avoiding the eta problem.

Contribution

It presents a novel inflationary model using a simple NMSSM variant with a singlet inflaton protected by Heisenberg symmetry, integrating string theory insights.

Findings

The model successfully drives inflation with F-term potential from supergravity.

It naturally solves the $mbda$ and strong CP problems.

The inflaton remains light during inflation due to symmetry protection.

Abstract

We propose a model of inflation based on a simple variant of the NMSSM, called $\phi$NMSSM where the additional singlet $\phi$ plays the role of the inflaton in hybrid (or inverted hybrid) type models. The $\phi$NMSSM solves the $\mu$ problem of the MSSM via the vacuum expectation value of the gauge singlet N, but also solves the strong CP problem through an approximate Peccei-Quinn symmetry. The potential energy which drives inflation originates from the F-term of the effective supergravity theory which result from a generic string theory. In the class of models considered the inflaton is protected from receiving mass during inflation by a Heisenberg symmetry, avoiding the $\eta$ problem.