Anomalous $Z′$ and diboson resonances at the LHC

We propose novel collider searches which can significantly improve the LHC reach to new gauge bosons Z ′ with mixed anomalies with the electroweak (EW) gauge group. Such a Z ′ necessarily acquires a Chern-Simons coupling to the EW gauge bosons and these couplings can drive both exotic Z decays into Z ′γ if the new gauge boson is sufficiently light, as well as Z ′ decays into EW gauge bosons. While the exotic decay rate of the heavy Z into Z ′γ is too small to be observed at the LHC, for a light Z ′, we show the potential of a lepton jet search in association with a photon to probe the rare decay Z → Z ′γ.