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.