Amplitudes Seminar

Modular symmetry of 2-loop Bhabha scattering

by YuJiao Zhu


We report an analytic computation of the 2-loop polarized Bhabha scattering in QED. We construct the amplitudes from a minimal set of physical projectors and make up the final results through a set of pure function bases. We corroborate one-loop exactness on the IR singularities of massive QED and derive the finite remainder functions. In addition, we consider the Regge limit and extract the electron Regge trajectory in massive QED. We study the analytic structure of the amplitude and reveal its underlying connections to hyperbolic Coxeter groups and arithmetic properties of elliptic curves.