Expansion by Subgraphs for Massless Scattering Processes

by Yao Ma (ETH Zurich)

Monday 10 Mar 2025, 14:00 → 15:00 Europe/Zurich

4/3-006 - TH Conference Room (CERN)

The expansion by regions is a powerful technique for analyzing the asymptotic behavior of Feynman integrals. The first step in applying this method is to identify all relevant regions. For relatively simple cases involving only Euclidean momenta, it has been shown that the expansion by regions is equivalent to "expansion by subgraphs." However, identifying these regions becomes significantly more challenging under Minkowski kinematics.

In this talk, we will explore asymptotic expansions for various massless particle scattering processes, including both the wide-angle and small-angle kinematics. We will review recent progress in identifying regions and demonstrate how the expansion-by-subgraphs technique can be extended to these scenarios. Additionally, some important implications for understanding the infrared structure of perturbative QCD will be discussed.

CERN_QCD_YaoMa.pdf