Correlation of top asymmetries: loop versus tree origins

TL;DR

This paper investigates how top quark asymmetries originating from loop or tree-level processes differ in size and sign, using specific models and QCD calculations to understand their correlation.

Contribution

It introduces a detailed analysis of the correlation between top asymmetries from different origins, supported by NLO QCD calculations and Monte Carlo simulations.

Findings

Correlation depends on the asymmetry's origin (loop or tree)

Different signs and sizes of asymmetries are observed

Color structure explains the correlation in QCD eikonal approximation

Abstract

We study the correlation of top asymmetries that are sensitive to the different origin of (a new contribution to) the total asymmetry: loop- or tree-level origins. We find that both the size and sign of the correlation between total and $t\bar{t}j$ inclusive asymmetries are inherently different depending on the origin. We demonstrate the correlation by using the color-singlet $Z^\prime$ and the pure axigluon taken as representative models of loop- and tree-induced total asymmetries. We calculate the next-to-leading order QCD corrections to the $Z^\prime$ and perform Monte-Carlo event generation. The correlation is understood in the QCD eikonal approximation using its color structure.