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

1 Institute for Theoretical Particle Physics, KIT, Karlsruhe, Germany Institute for Advanced Study, Princeton, NJ 08540, USA, USA Scientific Research Computing Center, Moscow State University, 119991 Moscow, Russia 4 Skobeltsyn Institute of Nuclear Physics of Moscow State University, 119991 Moscow, Russia Knowledge of two-loop QCD amplitudes for processes qq̄ → V1V2 → (l1 l̄ 1)(l2 l̄ 2) 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, WW, ZZ, WZ, Wγ, including off-shell effects and decays to leptons.