The effects of a new vector boson on the top quark cross section at the Tevatron

It has recently been shown that a new neutral vector boson Z′, with a mass of order 1 TeV and weak couplings to quarks only, could explain both the anomalous values of Rb and Rc and the apparent excess of large ET jet events measured by the CDF collaboration. We calculate the effects of Z′ exchange on the tt production cross section at Tevatron pp collider energies, including next-to-leading-order QCD corrections. We find a significant enhancement of the cross section and study the resulting tt invariant mass distribution, which could provide a decisive test of the Z′ model.