Next-to-Leading Order QCD Predictions for W+3-Jet Distributions at Hadron Colliders

TL;DR

This paper provides precise next-to-leading order QCD predictions for W+3-jet production at colliders, improving accuracy and understanding of scale dependence, and validating color approximation methods.

Contribution

It delivers the first accurate NLO QCD predictions for W+3-jet distributions at the LHC, including all subprocesses and decay channels, with validated color approximations.

Findings

Excellent agreement with Tevatron data

Reduced scale dependence in NLO calculations

Total transverse energy is a better scale choice

Abstract

We present next-to-leading order QCD predictions for a variety of distributions in W+3-jet production at both the Tevatron and the Large Hadron Collider. We include all subprocesses and incorporate the decay of the W boson into leptons. Our results are in excellent agreement with existing Tevatron data and provide the first quantitatively precise next-to-leading order predictions for the LHC. We include all terms in an expansion in the number of colors, confirming that the specific leading-color approximation used in our previous study is accurate to within three percent. The dependence of the cross section on renormalization and factorization scales is reduced significantly with respect to a leading-order calculation. We study different dynamical scale choices, and find that the total transverse energy is significantly better than choices used in previous phenomenological studies. We compute the one-loop matrix elements using on-shell methods, as numerically implemented in the BlackHat code. The remaining parts of the calculation, including generation of the real-emission contributions and integration over phase space, are handled by the SHERPA package.