2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/46112It is argued that the Next-to-MSSM (NMSSM) is unnatural from the point of view of cosmology and fine tuning. In particular, such singlet extensions to the MSSM do not provide a simple solution to the `$μ$-problem'. Models with singlets can be constructed using gauged-$R$ symmetry or target space duality. However their superpotentials have terms in addition to those of the NMSSM.7 pages, no figures, plain LaTeX; Talk presented at XXXIst Rencontres de Moriond, March 1996High Energy Physics - Phenomenologytext