Table 3
The naming of dark matter

Notation	Other notation	Symbol
dark matter		χχ̅
dark photon	heavy photon, dark force	A′, A, AD, U-boson
dark Higgs		H′, h0, HD
dark sector	hidden sector, secluded sector
kinetic mixing		ε2, κ2, χ2, α, α′,
coupling constant between dark photon and dark Higgs		αD