Four-Jet Production at the Large Hadron Collider at Next-to-Leading Order in QCD

TL;DR

The BLACKHAT library is used in conjunction with SHERPA and a recently developed algorithm for assembling primitive amplitudes into color-dressed amplitudes to adopt the cuts used by ATLAS in their study of multijet events in pp collisions at √s=7 TeV.

Abstract

We present the cross sections for production of up to four jets at the Large Hadron Collider, at next-to-leading order in the QCD coupling. We use the BlackHat library in conjunction with SHERPA and a recently developed algorithm for assembling primitive amplitudes into color-dressed amplitudes. We adopt the cuts used by ATLAS in their study of multi-jet events in pp collisions at \sqrt{s} = 7 TeV. We include estimates of nonperturbative corrections and compare to ATLAS data. We store intermediate results in a framework that allows the inexpensive computation of additional results for different choices of scale or parton distributions.

Figures (2)

• Figure 1: Sample diagrams for the six-parton one-loop amplitudes for $g g \rightarrow g g g g$ and $q \bar{Q} \rightarrow q Q' \bar{Q}'\bar{Q}$.
• Figure 2: A comparison of the 3/2 and 4/3 jet-production ratios to ATLAS data ATLASJets for $R=0.6$. We show the NLO and ME+PS predictions for these ratios. Vertical bars on the theory predictions represent Monte Carlo statistical uncertainties.