Light Z′ bosons at the Tevatron

Abstract

New gauge bosons with standard model-like couplings to leptons are constrained by collider searches to be heavier than approximately ∼1TeV. A Z′ boson with suppressed couplings to leptons, however, could be much lighter and possess substantial couplings to standard model quarks. In this article, we consider a new leptophobic Z′ gauge boson as a simple and well-motivated extension of the standard model, and discuss several of its possible signatures at the Tevatron. We find that three of the recent anomalies reported from the Tevatron-in particular, the top-quark forward-backward asymmetry and excesses in the 3b and W+2 jets final states-could be explained by a new Z′ with a mass of approximately 150GeV, relatively large couplings to quarks, and suppressed couplings to electrons and muons. Moreover, we find that such a particle could also mediate the interactions of dark matter, leading to potentially interesting implications for direct detection experiments. © 2011 American Physical Society.