Z' Bosons and Supersymmetry

Abstract

A broad class of supersymmetric extensions of the standard model predict a Z&#39; vector boson whose mass is naturally in the range 250 GeV < M_Z&#39; < 2 TeV. To avoid unacceptably large mixing with the Z, one requires either a discrete tuning of the U(1)&#39; charges or a leptophobic Z&#39;. Both cases are likely to arise as the low energy limits of heterotic string compactifications, but a survey of existing realistic string models provides no acceptable examples. A broken U(1)&#39; leads to additional D-term contributions to squark, slepton, and Higgs masses, which depend on the U(1)&#39; charge assignments and the Z&#39; mass. The Tevatron and future colliders can discover or decisively rule out this class of models.