Determination ofZ′gauge couplings to quarks and leptons at future hadron colliders

We point out that at future hadron colliders the ratio of cross sections for $\mathrm{pp}\to Z^{\prime }\to l^{+}{l}^{-}$ in two rapidity bins is a useful probe of the relative couplings of the $Z^{\prime }$ to $u$ and $d$ quarks. Combined with the forward-backward asymmetry, the rare decay modes $Z^{\prime }\to \mathrm{Wl}{\nu }_l$, and three associated productions $\mathrm{pp}\to Z^{\prime }V(V=Z, W, \gamma )$, and assuming interfamily universality, small $Z-Z^{\prime }$ mixing, and the $Z^{\prime }$ charge commuting with the $\mathrm{SU}{\mathrm{}\left(2\right)\mathrm{}}_L$ generators, three out of four normalized couplings could be extracted. An analysis of the statistical uncertainties expected for the above probes at the CERN LHC for typical models with $M_{Z^{\prime }}\simeq 1$ TeV shows that one lepton coupling and two combinations of quark couplings could be determined to around 5%, 20%, and 30%, respectively. This allows for a clear distinction between models.