Freeze-in of WIMP dark matter
Xiao-Rui Wang, Ke-Pan Xie
Abstract
We propose a novel scenario for DM in which weakly interacting massive particles (WIMPs) can freeze-in due to a first-order phase transition (FOPT) in the early Universe. The FOPT dilutes the preexisting DM density to zero and leads to a sudden change in DM mass, preventing WIMPs from reequilibrating due to their large mass-to-temperature ratio. Following the FOPT, WIMPs are produced via a freeze-in process, even though their interactions are not feeble. We demonstrate this concept using a simplified model and then apply it to a realistic model with a delayed electroweak phase transition. Our work presents a promising new direction for the freeze-in mechanism, and also extends the category of WIMP DM.
Topics & Concepts
WIMPPhysicsWeakly interacting massive particlesDark matterElectroweak interactionParticle physicsLight dark matterPhase transitionScalar field dark matterAstrophysicsDark energyCosmologyQuantum mechanicsCosmology and Gravitation TheoriesDark Matter and Cosmic PhenomenaParticle physics theoretical and experimental studies