Very Light Axigluons and the Top Asymmetry

TL;DR

This paper proposes that very light axigluons with flavor-universal couplings can explain the anomalous top forward-backward asymmetry while remaining consistent with other experimental constraints.

Contribution

It introduces a model with light axigluons (50-90 GeV) that accounts for the top asymmetry and evades existing experimental bounds.

Findings

Light axigluons can explain the top asymmetry.

Model is consistent with invariant mass distributions.

Searches need to target masses below current limits.

Abstract

We show that very light (50 - 90 GeV) axigluons with flavor-universal couplings of order g_{s}/3 may explain the anomalous top forward-backward asymmetry reported by both CDF and D0 collaborations. The model is naturally consistent with the observed t \bar t invariant mass distribution and evades bounds from light Higgs searches, LEP event shapes, and hadronic observables at the Z pole. Very light axigluons can appear as resonances in multijet events, but searches require sensitivity to masses below current limits.