Andrey Pikelner, "Simplifying N-jettiness soft function calculations at higher orders"

Wednesday 7 Oct 2026, 13:00 → 15:00 Europe/London

Precision predictions in QCD require accounting for radiation that is too soft or too close to another particle to be resolved as a separate jet. The N-jettiness variable is sensitive to this radiation and provides a useful tool for higher-order calculations. The associated soft functions are essential ingredients in higher-order subtraction schemes, but their calculation becomes increasingly difficult at each new order.

In this talk, I will describe a simpler way to calculate these functions. I will first review our semi-analytic calculation of the zero-jettiness soft function at N³LO and explain its main challenges. I will then introduce an approach that separates a simpler inclusive contribution from a correction that restores the exact measurement. At NNLO, this correction is finite and can be evaluated directly by numerical integration. I will show how the method works for both massless and massive hard partons, and how simple subtraction extends it to an independent N³LO zero-jettiness calculation. I will conclude with possible extensions to N³LO dipole contributions for an arbitrary N-jettiness soft function.