Vector-like Sneutrino Dark Matter

TL;DR

This paper explores vector-like sneutrino as a dark matter candidate within an extended MSSM, demonstrating natural mass splitting, relic density calculations, and compatibility with experimental bounds, including potential for lighter dark matter particles.

Contribution

It introduces a model with vector-like sneutrino dark matter that naturally achieves necessary mass splitting without large A-terms, expanding the viable parameter space.

Findings

Mass splitting can be naturally achieved without large A-terms.

Relic density calculations show viable dark matter candidates.

Elastic scattering cross sections are below current experimental bounds.

Abstract

In this paper, we discuss the MSSM extended with one vector-like lepton doublets $L$-$\overline{L}$ and one right-handed neutrino $N$. The neutral vecotor-like sneutrino can be a candidate of dark matter. In order to avoid the interaction with the necleons by exchanging a $Z$-boson, the mass splitting between the real part and the imaginary part of the sneutrino field is needed. Compared with the MSSM sneutrino dark matter, the mass splitting between the vector-like sneutrino field can be more naturally acquired without large A-terms and constraints on the neutralino masses. We have also calculated the relic density and the elastic scattering cross sections with the neucleons in the cases that the dark matter particles coannihilate with or without the MSSM slepton doublets. The elastic scattering cross sections with the neucleons are well below the LUX bounds. In the case that the dark matter coannihilate with all the MSSM slepton doublets, the mass of the dark matter can be as light as 370 GeV.