Natural Twin Neutralino Dark Matter

Supersymmetric twin Higgs models have a discrete symmetry for which each standard model particle and its supersymmetric partner have a corresponding state that transforms under a mirror standard model gauge group. This framework is able to accommodate the nondiscovery of new particles at the LHC with the naturalness of the electroweak scale. We point out that supersymmetric twin Higgs models also provide a natural dark matter candidate. We investigate the possibility that a twin binolike state is the lightest supersymmetric particle and find that its freeze-out abundance can explain the observed dark matter abundance without fine-tuning the mass spectrum of the theory. Most of the viable parameter space can be probed by future dark matter direct detection experiments, and the LHC searches for staus and Higgsinos which may involve displaced vertices.