  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 offer a strong tool to test this
scenario in collider experiments.
