Stealth decaying spin-1 dark matter

A bstract We consider models of decaying spin-1 dark matter whose dominant coupling to the standard model sector is through a dark-Higgs Yukawa portal connecting TeV-scale vector-like lepton (right-handed) electron. Below electron-positron threshold, has very slow, loop-suppressed decays photons and (electron) neutrinos, stable on cosmological time-scale for sufficiently small gauge values. Its relic abundance set by in-equilibrium decays, freeze-in mechanism. show that this accommodates observed natural values its parameters mass in ? 5 keV 1 MeV range, while evading constraints from direct detection, indirect stellar cooling cosmology. also possibility nonzero kinetic mixing with hypercharge field, which found yield mild impact model’s phenomenology.