Collider-independent t tbar forward-backward asymmetries

TL;DR

This paper introduces collider-independent forward-backward asymmetries for top quark pair production, enabling consistent comparison of asymmetries measured at the Tevatron and LHC to understand anomalies.

Contribution

It proposes a novel, collider- and center-of-mass-independent framework for measuring top quark asymmetries, linking Tevatron and LHC observations in a model-independent way.

Findings

Collider-independent asymmetries relate Tevatron and LHC measurements.

Measurement of these asymmetries can clarify the nature of observed anomalies.

Positive Tevatron asymmetry is compatible with small LHC asymmetry.

Abstract

We introduce the forward-backward asymmetries A_u, A_d corresponding to u ubar, d dbar -> t tbar production, respectively, at hadron colliders. These are collider- and center-of-mass-independent observables, directly related to the forward-backward and charge asymmetries measured at the Tevatron and the LHC, respectively. We discuss how to extract these asymmetries from data. Because these asymmetries are collider-independent, their measurement at these two colliders could elucidate the nature of the anomalous forward-backward asymmetry measured at the Tevatron. Our framework also shows in a model-independent fashion that a positive Tevatron asymmetry exceeding the standard model expectation is compatible with the small asymmetry measured at the LHC.