$W^+W^-$ production at NNLO+PS with MiNNLO$_{\rm PS}$

TL;DR

This paper presents a novel NNLO+PS calculation for $W^+W^-$ production that accurately includes spin, interference, and off-shell effects, matching to parton showers without needing reweighting, and shows good agreement with experimental data.

Contribution

First NNLO+PS calculation for $W^+W^-$ production that avoids a-posteriori reweighting and reduces computation time significantly.

Findings

Good agreement with ATLAS and CMS measurements

Both NNLO corrections and parton shower matching are crucial for accuracy

Provides the most precise fully exclusive $W^+W^-$ event simulation to date

Abstract

We consider $W^+W^-$ production in hadronic collisions and present the computation of next-to-next-to-leading order accurate predictions consistently matched to parton showers (NNLO+PS) using the MiNNLO$_{\rm PS}$ method. Spin correlations, interferences and off-shell effects are included by calculating the full process $pp \to e^+\nu_e \mu^-\bar{\nu}_\mu$. This is the first NNLO+PS calculation for $W^+W^-$ production that does not require an a-posteriori multi-differential reweighting. The evaluation time of the two-loop contribution has been reduced by more than one order of magnitude through a four-dimensional cubic spline interpolation. We find good agreement with the inclusive and fiducial cross sections measured by ATLAS and CMS. Both NNLO corrections and matching to parton showers are important for an accurate simulation of the $W^+W^-$ signal, and their matching provides the best description of fully exclusive $W^+W^-$ events to date.