Speaker
Description
We present an integrand-level representation of generic two-loop amplitudes in massless Quantum Electrodynamics (QED) that is free of IR singularities. We define building blocks that render the integrand manifestly polarised and Ward-identity preserving, in such a way that spurious (transient) singularities are removed. The full integrands are then assembled by gluing these building blocks together according to specific prescriptions that cure the additional transient singularities arising in the process. We present the locally UV-renormalised, IR-subtracted amplitude for generic two-loop QED processes, together with insights on possible extensions beyond two loops. This work can be regarded as a step towards an extension to QCD amplitudes with jets in the final state.
Based on a work in collaboration with C. Anastasiou, A. Favorito, G. Gambuti, R. Sahoo, G. Sterman