Less minimal supersymmetric standard model

Most of the phenomenological studies of supersymmetry have been carried out using the so-called minimal supergravity scenario, where one assumes a universal scalar mass, gaugino mass, and trilinear coupling at $M_{\mathrm{GUT}}.$ Even though this is a useful simplifying assumption, it is too restrictive to accommodate a large variety of phenomenological possibilities. It predicts that the lightest supersymmetric particle (LSP) is an almost pure B-ino. We extend the minimal scenario by introducing one extra parameter: the Fayet-Iliopoulos D term for ${U\left(1\right)\mathrm{}}_Y,$ $D_Y,$ and find a much more diverse phenomenology, where the LSP is ${\tilde{\nu }}_{\tau },$ $\tilde{\tau }$ or a Higgsino-like neutralino. We discuss the relevance of the different possibilities to collider signatures.