Anomalous $Z^{\prime }$ and Diboson Resonances at the LHC

Abstract

We propose novel collider searches which can significantly improve the LHC reach to new gauge bosons $Z^{\prime }$ with mixed anomalies with the electroweak (EW) gauge group. Such a $Z^{\prime }$ necessarily acquires a Chern-Simons coupling to the EW gauge bosons and these couplings can drive both exotic $Z$ decays into $Z^{\prime }{\hat{I}}^3$ if the new gauge boson is sufficiently light, as well as $Z^{\prime }$ decays into EW gauge bosons.While the exotic decay rate of the heavy $Z$ into $Z^{\prime }{\hat{I}}^3$ is too small to be observed at the LHC, for a light $Z^{\prime }$, we show the potential of a lepton jet search in association with a photon to probe the rare decay $Z\to Z^{\prime }{\hat{I}}^3$.

17 pages, 4 figures. v2: equation corrected, main results in Section 4 unchanged, accepted for publication in JHEP