Thermal Right-Handed Sneutrino Dark Matter in the F_D-Term Model of Hybrid Inflation

TL;DR

This paper investigates right-handed sneutrinos as dark matter candidates within the F_D-term hybrid inflation model, showing they can naturally account for observed dark matter abundance while solving other cosmological issues.

Contribution

It introduces a new viable dark matter candidate in the F_D-term model, demonstrating its thermalization and compatibility with cosmological data and direct detection constraints.

Findings

Right-handed sneutrinos can be thermal dark matter in the model.

The model predicts a new quartic coupling enabling sufficient annihilation.

Parameter space identified consistent with WMAP and detection experiments.

Abstract

We compute the relic abundance of the right-handed sneutrinos in the supersymmetric F_D-term model of hybrid inflation. As well as providing a natural solution to the mu- and gravitino overabundance problems, the F_D-term model offers a new viable candidate to account for the cold dark matter in the Universe: the lightest right-handed sneutrino. In particular, the F_D-term model predicts a new quartic coupling of purely right-handed sneutrinos to the Higgs doublets that thermalizes the sneutrinos and makes them annihilate sufficiently fast to a level compatible with the current cosmic microwave background data. We analyze this scenario in detail and identify favourable regions of the parameter space within the framework of minimal supergravity, for which the lightest right-handed sneutrino becomes the thermal dark matter, in agreement with WMAP observations of cosmological inflation. Constraints derived from direct dark matter searches experiments are presented.