Prominent Decay Modes of a Leptophobic Z'

Abstract

An anomaly-free U(1) charge $Q'$ has recently been identified within the group E$_6$ 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 {\it exotic} leptons within E$_6$ 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 $u \bar u \to Z' \to f \bar f$ channels when $f$ is a standard up-type quark, an exotic down-type quark, or an exotic lepton.