Hiding the little hierarchy problem in the NMSSM

Abstract

In this paper we consider a set of soft supersymmetry breaking terms within the NMSSM which leads to a small hierarchy between the supersymmetry breaking scale and the electroweak scale. Specifically only the gaugino masses and the soft term in the Higgs sector are non-vanishing at the GUT scale. This pattern can be found in gaugino mediated models and in higher-dimensional orbifold GUTs. We study the phenomenology of this scenario and find different low energy spectra depending on the Yukawa coupling $λ$ of the NMSSM singlet. In particular, for low values of $λ$ the singlet is the lightest scalar and the singlino is the LSP while for large values of $λ$ both are heavy and the gravitino can be the LSP. The singlet pseudoscalar is very light in the entire parameter space.

Latex, 21+1 pages, 5 figures; v2: References and comments added