Abstract
The mixing of a new Z′ boson with the Z significantly improves the fit to the LEP precision electroweak data, provided that the Z′ couples mainly to quarks. If M <sub>Z2</sub> < 200 GeV, the s-channel Z <sub>2</sub> production and (W, Z, γ) Z <sub>2</sub> pair production cross sections at the Tevatron give an excess above QCD of bb̄ and (W, Z, γ) bb̄ events, respectively, with invariant mass m(bb̄) ≈ M <sub>Z2</sub> , which provide viable signals for detection of the Z <sub>2</sub> . The interference of the Z <sub>2</sub> with γ, Z <sub>1</sub> in e <sup>+</sup> e <sup>-</sup> → b̄b (c̄c) at LEP 1.5 energies is correlated with R <sub>b</sub> (R <sub>c</sub> ) and may be observable.