Two-loop helicity amplitudes for the production of two off-shell electroweak bosons in quark-antiquark collisions

Knowledge of two-loop QCD amplitudes for processes qq′→V1V2→l1l¯1′l2l¯2′\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ qq^{\prime}\to {V}_1{V}_2\to \left({l}_1{\overline{l}}_1^{\prime}\right)\left({l}_2{\overline{l}}_2^{\prime}\right) $$\end{document} is important for improving the theoretical description of four-lepton production in hadron collisions. In this paper we compute these helicity amplitudes for all intermediate vector bosons, V1V2 = γ*γ*, W+W−, ZZ, W±Z, W±γ*, including off-shell effects and decays to leptons.