Dark Gauge Bosons: LHC Signatures of Non-Abelian Kinetic Mixing

Abstract

We consider non-abelian kinetic mixing between the Standard Model SU(2${)}_L$ and a dark sector U(1${)}^{\prime }$ gauge group associated with the presence of a scalar SU(2${)}_L$ triplet. The magnitude of the resulting dark photon coupling $ϵ$ is determined by the ratio of the triplet vacuum expectation value, constrained to by $\text{lsim}4$ GeV by electroweak precision tests, to the scale $\Lambda$ of the effective theory. The corresponding effective operator Wilson coefficient can be $\mathcal{O}(1)$ while accommodating null results for dark photon searches, allowing for a distinctive LHC dark photon phenomenology. After outlining the possible LHC signatures, we illustrate by recasting current ATLAS dark photon results into the non-abelian mixing context.

Comments: 12 pages, 5 figures