Pseudo Nambu-Goldstone Dark Matter: Examples of Vanishing Direct Detection Cross Section

Abstract

We consider cases where the dark matter-nucleon interaction is naturally suppressed. We explicitly show that by extending the standard model scalar sector by a number of singlets, can lead to a vanishing direct detection cross section, if some softly broken symmetries are imposed in the dark sector. In particular, it is shown that if said symmetries are $SU(2)$ ($SU(N)$) and $U(1)\times S_N$, then the resulting pseudo-Nambu-Goldstone bosons can constitute the dark matter of the Universe, while naturally explaining the missing signal in nuclear recoil experiments.

Comments: 13 pages, 1 figure, v2: references added. v3: estimate and comments on the 1-loop direct detection cross section added, clarified some points in the minimization of the potentials. Version published in Phys. Rev. D