Dark matter in classically conformal theories: WIMP and supercooling

Abstract

Beyond solving the hierarchy problem, classically conformal (CC) theories naturally accommodate dark matter (DM). In this work, we explore the CC $SU(2)_X$ gauge theory with a triplet dark scalar, uncovering two distinct DM scenarios: weakly interacting massive particle (WIMP) and supercooled DM. The production mechanisms are strongly influenced by the CC model's unique first-order phase transition evolution history, which differs significantly from those in non-conformal models. We obtain the viable parameter space for each scenario and investigate the current constraints and future sensitivities at experiments, demonstrating that gravitational wave signals from the phase transition provide a common detection channel for both the WIMP and supercooled DM regimes.