Dark matter from 't Hooft anomaly matching

Abstract

Light fermions that arise as composite states in confining gauge theories are stable due to fermion number conservation. This leads to dark matter (DM) candidates that behave similarly to elementary DM but where the cosmological stability arises automatically from the accidental symmetries of the theory. We present explicit models based on 't Hooft anomaly matching conditions where DM is charged under the SM. For example an SU(N) gauge theory with fermions in the adjoint rep and triplet of SU(2)L gives rise to DM made of multiple "Wino"triplets, while SO(N) gauge theories with NF=N-4 flavors produce neutralinolike systems or SM quintuplets. Compositeness effects are crucial to determine the phenomenology.