Stealth gluons at hadron colliders

TL;DR

This paper proposes a model with a heavy gluon that explains the Tevatron's top-antitop asymmetry without conflicting with other data, by considering energy-dependent widths and new decay modes involving vector-like quarks.

Contribution

It introduces a comprehensive treatment of energy-dependent width effects and a novel decay channel for the heavy gluon, aligning the model with experimental observations.

Findings

Heavy gluon with mass 800-900 GeV can explain the asymmetry.

New decay mode G->qQ makes the gluon invisible in certain distributions.

Model remains consistent with existing collider data.

Abstract

We find that a heavy gluon G of mass 800-900 GeV with small, mostly axial-vector couplings to the light quarks and relatively large vector and axial-vector couplings to the top quark can explain the t \bar{t} forward-backward asymmetry observed at the Tevatron with no conflict with other top-quark or dijet data. The key ingredient is a complete treatment of energy-dependent width effects and a new decay mode G->qQ, where q is a standard quark and Q a vector-like quark of mass 400--600 GeV. We show that this new decay channel makes the heavy gluon invisible in the t\bar{t} mass invariant distribution and discuss its implications at the Tevatron and the LHC.