Dilepton signatures of family non-universal U1

The supersymmetric models extending the minimal supersymmetric Standard Model (MSSM) by an additional Abelian gauge factor U(1 in order to solve the μ problem do generically suffer from anomalies disrupting the gauge coupling unification found in the MSSM. The anomalies are absent if the minimal matter content necessitated by the μ problem is augmented with exotic matter species having appropriate quantum numbers. Recently, it has been shown that anomaly cancellation can also be accomplished by introducing family non-universal U(1 charges and non-holomorphic soft-breaking terms [D.A. Demir, G.L. Kane, T.T. Wang, Phys. Rev. D 72 (2005) 015012, hep-ph/0503290]. We discuss collider signatures of anomaly-free family non-universal U(1 model by analyzing dilepton production in future colliders. We find that, both at LHC and NLC, one can establish existence/absence of such a Z boson by simply comparing the number of dilepton production events for electron, muon and tau lepton. The signal is free of the SM background.