Quantum Information in Scattering: From Amplitude Poles to Entanglement Features

Probing quantum entanglement in high-energy collisions has recently become a rapidly growing direction in particle physics, aiming to measure quantum correlations at the highest energy scales accessible to humans. A key question is how such entanglement relies on the analytic structure of scattering amplitudes. In this talk, I will show that the pole structure, associated with intermediate heavy particles, leads to distinctive entanglement features. When a heavy particle mediates inelastic scatterings with three or more final particles, the entanglement entropy between its decay products and the rest exhibits a universal dip as the energy increases, reflecting the limited information flow through on-shell heavy particles and signaling entanglement suppression in the heavy-particle-dominated regime. This reveals entanglement structures beyond the usual “area-law” behavior of 2-to-2 processes. Finally, I will comment on possible ways to probe these features experimentally through analyses of final-state phase-space distributions. This talk is based on JHEP 10 (2025) 003 [arXiv: 2507.03555].