Models for SIMP dark matter and dark photon

We give a review on the SIMP paradigm and discuss a consistent model for SIMP dark mesons in the context of a dark QCD with flavor symmetry. The $Z^{\mathrm{\prime }}$-portal interaction is introduced being compatible with stable dark mesons and is responsible for making the SIMP dark mesons remain in kinetic equilibrium with the SM during the freeze-out process. The SIMP parameter space of the $Z^{\mathrm{\prime }}$ gauge boson can be probed by future collider and direct detection experiments.