Dark matter and a new gauge boson through kinetic mixing

Abstract

We consider a hidden sector model of dark matter which is charged under a hidden U(1)_X gauge symmetry. Kinetic mixing of U(1)_X with the Standard Model hypercharge U(1)_Y is allowed to provide communication between the hidden sector and the Standard Model sector. We present various limits on the kinetic mixing parameter and the hidden gauge coupling constant coming from various low energy observables, electroweak precision tests, and the right thermal relic density of the dark matter. Saturating these constraints, we show that the spin-independent elastic cross section of the dark matter off nucleons is mostly below the current experimental limits, but within the future sensitivity. Finally, we analyze the prospect of observing the hidden gauge boson through its dimuon decay channel at hadron colliders.Comment: 21 pages, 9 figures, references adde

Extra U(1) as natural source of a monochromatic gamma ray line

“…It could be interesting to notice that in any of the cases discussed above, the direct detection rate is largely suppressed. Indeed, this rate can become important for a kinetic mixing around δ ≃ 10 −3 [29][30][31][32][33] and could even explain DAMA/CoGENT excess with δ ≃ 10 −2 . However, in the model we are considering, the "portal" between the dark matter sector and the visible one does not go through this kinetic mixing, but through the trivectorial couplings generated in eq.…”

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