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

TL;DR

This paper explores non-abelian kinetic mixing between the Standard Model and a dark sector, analyzing how it can produce detectable LHC signatures while remaining consistent with existing dark photon search constraints.

Contribution

It introduces a novel non-abelian kinetic mixing framework involving an SU(2) triplet, detailing its implications for LHC dark photon phenomenology and recasting current experimental results.

Findings

Dark photon coupling $mbda$ can be sizable despite null search results.

Distinctive LHC signatures are predicted for non-abelian kinetic mixing.

Current ATLAS results can be interpreted within this new mixing framework.

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 $\epsilon$ is determined by the ratio of the triplet vacuum expectation value, constrained to by $\lsim 4$ 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.