Long-lived stops in MSSM scenarios with a neutralino LSP

Understand

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 coanihilation cross section, leaving the neutralino relic density lower than what is expected from the WMAP results for stop masses ~1.5 TeV/c^2.