Single Vectorlike Quark Production at the LHC

TL;DR

This paper explores the potential of a broad gluon resonance below 1 TeV, decaying into vectorlike quarks, to explain the Tevatron's top-antitop asymmetry and discusses how current and minimal LHC analyses can probe this model.

Contribution

It provides a comprehensive analysis of gluon resonances decaying into vectorlike quarks, highlighting experimental challenges and proposing minimal modifications to current searches to explore the model's parameter space.

Findings

Current searches cannot fully probe the model.

Minimal analysis modifications can explore large parameter regions.

Reconstruction of heavy quarks and gluons can confirm the asymmetry origin.

Abstract

A gluon resonance G of mass below 1 TeV could be the origin of the t\bar{t} forward-backward asymmetry observed at the Tevatron provided that new decay modes G->\bar{q}Q, with q a standard quark and Q its massive excitation, make G broad enough. We consider all the different cases, with q the top, the bottom or a light quark and dominant decay modes Q->Wq' or Q->Zq. We show that current experimental searches are unable to probe the model, but that minimal departures from these analyses can explore a large region of its parameter space for the current LHC luminosity. This includes the challenging case with the new quarks decaying mostly into light quark flavors. In some channels not only the heavy quark but also the massive gluon can be reconstructed, which would stablish the origin of the t\bar{t} asymmetry. Similar analyses can be applied to more general models with new massive gluons and vectorlike quarks.