Cuts of forward loops at N2LO and beyond
Gaia Fontana (University of Zurich)

Theoretical predictions beyond tree-level are necessary for a meaningful comparison between theory and experiment. Their calculation makes it inevitable to deal with infrared (IR) divergencies, stemming from partons becoming soft or collinear. One way to overcome them is to resort to subtraction schemes. In this talk, I will present the antenna subtraction scheme and the current efforts to extend it to N3LO, focusing on the situation where hard radiators are both in the initial and in the final state. First, I will review the extension of the N2LO initial-final antennae to higher epsilon order and present a purely analytic strategy to fix the boundary conditions of the relevant phase-space integrals (based on the Auxiliary Mass Flow method). Finally, I present the status of the calculation of N3LO initial-final antennae and the theoretical machinery necessary to perform this it, which includes translating phase space integrals into cuts of loop integrals, finding a canonical basis and fixing boundary conditions.