Dark photon dark matter in the minimal B − L model

Abstract

The extension of the Standard model (SM) with three heavy right handed neutrinos, a complex scalar and the gauged U(1)B−L symmetry (the minimal B − L model) is considered the most compelling minimal one: the presence and the out-of-equilibrium decay of the heavy right handed neutrinos can account for the small masses of the active neutrinos and the baryon asymmetry of the universe. A natural accompanying question concerns whether the minimal B − L model can naturally accommodate an interesting dark matter (DM) candidate. We study the possibility where the current DM population is explained by the gauge boson of U(1)B−L symmetry. We discuss how the minimal set-up originally aimed at the seesaw mechanism and the leptogenesis is connected to conditions making the gauge boson promoted to a DM candidate.