Speaker
Description
We present a unified study of vector dark matter (VDM) from hidden gauge symmetries U(1)D or SU(2)D. Starting from the renormalizable Higgs-portal UV theory for VDM with a dark Higgs field, we integrate out the radial mode of the dark Higgs to derive the leading low-energy interactions for Higgs-portal VDM, which are constrained into the validity domain in the UV theory. We also make the VDM stability realized: for U(1)D, a dark charge-conjugation (residual Z2) forbids VDM from decaying; for SU(2)D, a residual/custodial symmetry similarly stabilizes the lightest state of VDM. While the Higgs-portal EFT for VDM looks similar in both cases, non-abelian self-interactions of SU(2)D qualitatively modify the thermal history relative to U(1)D. Finally, we show how the isospin representation of the dark Higgs that breaks SU(2) controls the VDM mass spectrum and the VDM–dark-Higgs interactions, and how this feeds into the relic density and phenomenology, highlighting the representation-dependent signatures.
