Monte Carlo event generators & the top quark forward--backward asymmetry

TL;DR

This paper investigates how coherent parton showering in Monte Carlo event generators can produce a forward--backward asymmetry in top quark pair production, which is absent at leading order.

Contribution

The study compares different parton shower models and discusses the phenomenological implications of color coherence effects at the Tevatron.

Findings

Coherent showering can generate a measurable asymmetry.

Different shower implementations yield varying asymmetry predictions.

Color coherence effects are significant in top quark production phenomenology.

Abstract

The leading-order accurate description of top quark pair production, as usually employed in standard Monte Carlo event generators, gives no rise to the generation of a forward--backward asymmetry. Yet, non-negligible -- differential as well as inclusive -- asymmetries may be produced if coherent parton showering is used in the hadroproduction of top quark pairs. In this contribution we summarize the outcome of our study of this effect. We present a short comparison of different parton shower implementations and briefly comment on the phenomenology of the colour coherence effect at the Tevatron.