Higgsphobic and fermiophobic Z' as a single dark matter candidate

A spin-1 Z' particle as a single dark matter candidate is investigated by assuming that it does not directly couple to the Higgs boson and standard model fermions and does not mix with the photon and Z boson. The remaining dominant vertices are quartic Z (') Z (') ZZ and Z (') Z (') W (+) W (-), which can induce effective couplings through standard-model gauge-boson loops. We discuss constraints from the cosmological thermal relic density, and direct and indirect-detection experiments, and find that a dark Z' can only exist above the W boson mass threshold, and the effective quartic coupling of Z (') Z (') VV is bounded in the region of 10(-3) similar to 10(-2).