Baryonic Z' explanation for the CDF Wjj excess.

The latest CDF anomaly, the excess of dijet events in the invariant-mass window 120-160 GeV in associated production with a W boson, can be explained by a baryonic Z' model in which the Z' boson has negligible couplings to leptons. Although this Z' model is hardly subject to the Drell-Yan constraint from Tevatron, it is constrained by the dijet data from UA2 (√s=630 GeV), and the precision measurements at LEP through the mixing with the SM Z boson. We show that under these constraints this model can still explain the excess in the M(jj)∼120-160  GeV window, as well as the claimed cross section σ(WZ')∼4  pb. Implications at the Tevatron would be the associated production of γZ', ZZ', and Z'Z' with the Z'→jj. We show that with tightened jet cuts and improved systematic uncertainties both γZ'→γjj and ZZ'→ℓ(+)ℓ(-) jj channels could be useful to probe this model at the Tevatron.