Probing bino–gluino coannihilation at the LHC

It has been widely known that bino-like dark matter in the supersymmetric (SUSY) theories in general suffers from over-production. The situation can be drastically improved if gluinos have a mass slightly heavier than the bino dark matter as they reduce the dark matter abundance through coannihilation. In this work, we consider such a bino–gluino coannihilation scenario in high-scale SUSY models, which can be actually realized when the squark-mass scale is less than 100–1000 TeV. We study the prospects for exploring this bino–gluino coannihilation scenario at the LHC. We show that the searches for long-lived colored particles with displaced vertices or large energy loss offer a strong tool to test this scenario in collider experiments.