Long-lived stops in MSSM scenarios with a neutralino LSP

This work investigates the possibility of a long-lived stop squark in supersymmetric models with the neutralino as the lightest supersymmetric particle (LSP). We study the implications of meta-stable stops on the sparticle mass spectra and the dark matter density. We find that in order to obtain a sufficiently long stop lifetime so as to be observable as a stable R -hadron at an LHC experiment, we need to fine tune the mass degeneracy between the stop and the LSP considerably. This increases the stop-neutralino co-anihilation cross section, leaving the neutralino relic density lower than what is expected from the WMAP results for stop masses ≲1.5 TeV/ c 2 . However, if such scenarios are realised in nature we demonstrate that the long-lived stops will be produced at the LHC and that stop-based R -hadrons with masses up to 1 TeV/c 2 can be detected after one year of running at design luminosity.