NLO QCD corrections to the production of W+ W- plus two jets at the LHC

TL;DR

This work delivers a complete NLO QCD calculation for pp → W+W− jj at the LHC, incorporating leptonic W decays with full spin correlations. It combines MadGraph/MadDipole for LO and real emission with the GoSam framework for automated one-loop amplitudes, explicitly accounting for diagrams with vector bosons attached to fermion loops and third-generation quarks in loops. The study finds NLO corrections of about 10% under standard LHC cuts and a significant reduction of scale uncertainty from roughly 30% at LO to about 6% at NLO. It also demonstrates GoSam’s capability to handle complex multi-leg processes and quantifies the impact of previously neglected virtual contributions on the overall prediction, providing an important SM background input for Higgs and new physics searches.

Abstract

We present the full NLO QCD corrections to the production of a W^+W^- pair in association with two jets in hadronic collisions, which is an important background to New Physics and Higgs boson searches. We include leptonic decays of the W-bosons with full spin correlations. We find NLO corrections of the order of 10% for standard cuts at the LHC. The scale dependence is considerably reduced by the NLO corrections.

Figures (5)

• Figure 1: Dependence of the LO and NLO cross sections $pp\rightarrow W^+(\rightarrow\nu_e \,e^+) W^-(\rightarrow \mu^- \bar{\nu}_\mu)\, j j$ at $\sqrt{s}=7$ TeV on renormalisation and factorisation scales. We use $\mu=\mu_R=\mu_F$ and vary between $M_W\leq \mu\leq 4\,M_W$.
• Figure 2: Transverse momenta of the two tagging jets at $\sqrt{s}=7$ TeV. The jets are ordered according to their $p_\perp$. The bands describe the pdf and statistical error as well as the scale variations between $M_W\leq \mu\leq 4\,M_W$.
• Figure 3: Transverse momentum of the electron, in $p p \rightarrow e^+\nu_e\mu^-\bar{\nu}_\mu\,j j$ at $\sqrt{s} = 7$ TeV.
• Figure 4: Distribution for the opening angle between the leptons, $\phi_{e^+\mu^-}$.
• Figure 5: Contribution of the three types of virtual corrections to the leading jet $p_{\perp}$ distribution. Each contribution is normalised to the next-to-leading order cross section. For a better visibility the distributions for part B and C have been multiplied with $-10$ and $10$ respectively. For the scale we chose here $\mu=2 \, M_W$. See text for further details.