Theoretical and Experimental Constraints on $\mathbb{Z}_{2n}$ Multi-Component Dark Matter Models

Abstract: We investigate extensions of the Standard Model (SM) featuring two-component scalar dark matter (DM) stabilized by a $\mathbb{Z}{2n}$ symmetry. We focus on three specific cases, $\mathbb{Z}_4$, $\mathbb{Z}_6(23)$, and $\mathbb{Z}_6(13)$, each with a complex and a real scalar singlet. Through detailed numerical scans, we explore the viable parameter space, imposing constraints from DM relic abundance (Planck), direct detection (XENON1T, LZ, PandaX-4T), vacuum stability, perturbative unitarity, and coupling perturbativity up to the GUT and Planck scales, using one-loop renormalization group equations (RGEs). Our results demonstrate that these $\mathbb{Z}{2n}$ models can provide viable two-component DM scenarios, consistent with all imposed constraints, for a range of DM masses and couplings. We identify the key parameters controlling the DM phenomenology and highlight the importance of a combined analysis incorporating both theoretical and experimental bounds.