Heavy octets and Tevatron signals with three or four b jets

Abstract

Hypothetical color-octet particles of spin 0, pair-produced at hadron colliders through their QCD coupling, may lead to final states involving three or four b jets. The scalar octets may also be resonantly produced in pairs via a spin-1 octet, as we show within a renormalizable coloron model. We analyze kinematic distributions of the 3b final state that differentiate between these two production mechanisms, as well as between scalar octets and supersymmetric Higgs bosons. A scalar octet of mass in the 140-150GeV range can explain the nonstandard shape of the b-jet transverse energy distributions reported by the CDF Collaboration, especially when the coloron mass is slightly above twice the scalar mass. The dominant decay mode of the scalar octet in that case is into a pair of gluons, so that the production of a pair of dijet resonances is large in this model, of about 40 pb at the Tevatron. Even when a W boson is radiated from the initial state, the inclusive cross section for producing a dijet resonance near the scalar octet mass remains sizable, around 0.15 pb.