W+jets Matrix Elements and the Dipole Cascade

TL;DR

This work extends the CKKW matrix-element matching framework to the ARIADNE dipole cascade for hadronic collisions, specifically targeting $W+n$ jet production. By constructing complete dipole histories from MEG states, reweighting with exact ARIADNE Sudakovs and PDF ratios, and incorporating remnant-dipole dynamics, the authors achieve a smoother, cutoff-insensitive description of multi-jet final states. Compared to conventional showers (e.g., PYTHIA) and to uncorrected ARIADNE, the approach improves certain kinematic correlations and jet-rates, while preserving overall normalization via PDFs and $oldsymbol{}fs$. The results indicate significant potential for accurate background modeling at the Tevatron and LHC, and motivate future extensions to DIS and high-energy collider environments where small-$x$ evolution and unordered emissions become more prominent.

Abstract

We extend the algorithm for matching fixed-order tree-level matrix element generators with the Dipole Cascade Model in Ariadne to apply to processes with incoming hadrons. We test the algoritm on for the process W+n jets at the Tevatron, and find that the results are fairly insensitive to the cutoff used to regularize the soft and collinear divergencies in the tree-level matrix elements. We also investigate a few observables to check the sensitivity to the matrix element correction.