Precise QCD predictions on top quark pair production mediated by massive color octet vector boson at hadron colliders

TL;DR

This paper develops a model-independent framework for calculating next-to-leading order QCD corrections to top quark pair production mediated by a massive color octet vector boson at hadron colliders, highlighting the importance of the dynamical scale scheme.

Contribution

It introduces a systematic, model-independent method for NLO QCD calculations in processes involving massive COVB, emphasizing the advantages of the dynamical scale scheme over the fixed scale scheme.

Findings

NLO QCD corrections are more accurately computed using the dynamical scale scheme.

Naive rescaling of LO results with SM NLO K-factors is inadequate.

Dynamical scale scheme provides more reasonable predictions for top quark pair observables.

Abstract

We present a theoretical framework for systematically calculating next-to-leading order (NLO) QCD effects to various experimental observables in models with massive COVB in a model independent way at hadron colliders. Specifically, we show the numerical results for the NLO QCD corrections to total cross sections, invariant mass distribution and AFB of top quark pairs production mediated by a massive COVB in both the fixed scale (top quark mass) scheme and the dynamical scale (top pair invariant mass) scheme. Our results show that the NLO QCD calculations in the dynamical scale scheme is more reasonable than the fixed scheme and the naive estimate of the NLO effects by simple rescaling of the LO results with the SM NLO K-factor is not appropriate.