Low Mass Gluino within the Sparticle Landscape, Implications for Dark Matter, and Early Discovery Prospects at LHC-7

TL;DR

This paper explores supergravity models predicting low mass gluinos (350-700 GeV), analyzing their potential for early detection at LHC-7, and discusses their implications for dark matter and experimental bounds.

Contribution

It provides a comprehensive analysis of low mass gluino models within supergravity frameworks, including their discovery prospects and dark matter implications.

Findings

Most models require only ~1 fb^{-1} for discovery at LHC-7.

Models are consistent with current experimental bounds.

Some models can explain the PAMELA positron excess.

Abstract

We analyze supergravity models that predict a low mass gluino within the landscape of sparticle mass hierarchies. The analysis includes a broad class of models that arise in minimal and in non-minimal supergravity unified frameworks and in extended models with additional $U(1)^n_X$ hidden sector gauge symmetries. Gluino masses in the range $(350-700)$ GeV are investigated. Masses in this range are promising for early discovery at the LHC at $\sqrt s =7$ TeV (LHC-7). The models exhibit a wide dispersion in the gaugino-Higgsino eigencontent of their LSPs and in their associated sparticle mass spectra. A signature analysis is carried out and the prominent discovery channels for the models are identified with most models needing only $\sim 1 \rm fb^{-1}$ for discovery at LHC-7. In addition, significant variations in the discovery capability of the low mass gluino models are observed for models in which the gluino masses are of comparable size due to the mass splittings in different models and the relative position of the light gluino within the various sparticle mass hierarchies. The models are consistent with the current stringent bounds from the Fermi-LAT, CDMS-II, XENON100, and EDELWEISS-2 experiments. A subclass of these models, which include a mixed-wino LSP and a Higgsino LSP, are also shown to accommodate the positron excess seen in the PAMELA satellite experiment.