Reconciling the LEP and SLAC measurements of sin2θw

We consider whether a discrepancy between the SLAC and LEP measurements of sin2θw can be explained by new physics. We find that only the contribution of a new neutral gauge boson, Z′, nearly degenerate with the Z can affect the SLAC measurement while leaving the LEP observables almost unaffected. We briefly discuss possible signals for this new gauge boson, including changes in the Z lineshape when measured with polarized electrons, small change in Rb, AFBe, and larger changes in two jet and tt production at hadron colliders.