Blackboard talks on recent papers about new developments in subtraction methods and multi-loop amplitudes for LHC phenomenology
2410.12904 [Matteo Marcoli]: We define, construct and implement generalized antenna functions at NNLO (final-state only), characterized by having more than two hard radiators. These new antenna functions, equipped with suitable momentum mappings, allow to address almost colour-connected double emissions in a particularly straightforward way, bringing major simplifications in the subtraction infrastructure and significant computational speedup. Validation in the context of three-jet production at electron-positron colliders is discussed.
2410.19088 (and 2307.15405) [Petr Jakubcik]: My talk summarises recent progress in the calculation of 3-loop amplitudes for Z+jet and H+jet production at N3LO in hadron collisions. I will describe how we evaluated the necessary master integrals and built out of them a basis of transcendental functions which are minimal and graded into groups with expected or spurious properties. With a few simple examples, I will demonstrate how this method constrains the form of a multiloop amplitude without an expensive reduction, and how we used it to discover surprising simplifications in H+jet amplitudes which will lead to their compact representation and efficient evaluation.