The two-loop helicity amplitudes for gg → V₁ V₂ → 4 leptons

Abstract: We compute the two-loop massless QCD corrections to the helicity amplitudes for the production of two electroweak gauge bosons in the gluon fusion channel, gg → V₁V₂, keeping the virtuality of the vector bosons V₁ and V₂ arbitrary and taking their decays into leptons into account. The amplitudes are expressed in terms of master integrals, whose representation has been optimised for fast and reliable numerical evaluation. We provide analytical results and a public C++ code for their numerical evaluation on HepForge at http://vvamp.hepforge.org.