Multi-component dark matter and Galactic 511 keV $\gamma$-ray emission

• DOI: 10.48550/arxiv.2409.07851
• Publication Date: 2024-09-12
• Authors: Sarif Khan; Jinsu Kim; Jong‐Kuk Kim; Pyungwon Ko
• Keywords: Component (thermodynamics)

We study multi-component dark matter scenarios and the Galactic 511 keV $\gamma$-ray emission line signal in framework of a local, $U(1)_D$ extension Standard Model. A light vector particle associated with may decay annihilate to electron-positron pairs. The produced positrons turn form positroniums that subsequently two photons, accounting for observed emission. Three are investigated. First, we consider minimal where gauge boson Higgs newly introduced content. As second scenario, WIMP-type introduction an extra fermion which, addition boson, contribute relic abundance. It is thus scenario UV-complete symmetry. In particular, account small fraction total Finally, particles FIMP-type. this case, both be via freeze-in super-WIMP mechanisms. Considering theoretical observational constraints, explore allowed parameter space can explained. also discuss possible signatures.