Prominent decay modes of a leptophobic Z′

An anomaly-free U(1) charge Q′ has recently been identified within the group E6 for which the familiar leptons (the left- and right-handed electron and the left-handed neutrino) have Q′ = 0. It is pointed out that the Q′ charges of several exotic leptons within E6 matter multiplets are quite large, leading to the prediction that half of the decays of the so-called “leptophobic” Z′ bosons coupling to Q′ are to these exotic leptons. Other large Q′ charges include those of standard up-type quarks and exotic down-type quarks. Substantial forward-backward asymmetries are expected in uu → Z′ → ff channels when f is a standard up-type quark, an exotic down-type quark, or an exotic lepton.