A Sneutrino NLSP in the $\nu$CMSSM

TL;DR

This paper explores the impact of adding a right-handed neutrino to the CMSSM, focusing on scenarios where the sneutrino is the NLSP and its implications for dark matter relic density.

Contribution

It introduces the $ u$CMSSM with a right-handed neutrino and analyzes the conditions for a sneutrino NLSP, revealing new coannihilation regions affecting dark matter predictions.

Findings

Sneutrino can be the NLSP in the $ u$CMSSM.

New sneutrino coannihilation regions match WMAP relic density.

Impacts on dark matter properties in supersymmetric models.

Abstract

We extend the constrained minimal supersymmetric model (CMSSM) by adding a right-handed neutrino superfield ($\nu$CMSSM) which decouples close to the GUT scale. We study the effects of a right-handed neutrino on the low energy spectrum and focus on the predictions for dark matter properties. We pay particular attention to the realization of the light (left-handed) sneutrino which can be the next-to-lightest supersymmetric particle (NLSP) with either the neutralino or gravitino as the lightest supersymmetric particle (LSP). Notably, for the case of a neutralino LSP with a sneutrino NLSP, there are new `sneutrino coannihilation regions' which yield the desired thermal neutralino relic density determined by WMAP.