Two-loop QED/QCD corrections for polarized $\gamma\gamma\rightarrow\gamma\gamma$ process in SANCphot

TL;DR

This paper introduces an upgraded SANCphot integrator capable of efficiently computing two-loop polarized light-by-light scattering amplitudes, aiding high-energy photon physics research, especially for the CEPC project.

Contribution

It presents the first implementation of two-loop QED/QCD corrections for polarized gamma-gamma scattering within the SANCphot framework.

Findings

Enhanced numerical stability and speed for two-loop calculations

Successful application to polarized photon scattering processes

Support for high-energy physics experiments like CEPC

Abstract

The new version of the SANCphot integrator has been prepared for fast and stable numerical calculations up to two loops for polarized light-by-light scattering. One-loop modules based on the helicity formalism with massive particles and two-loop modules with massless particles inside the loops are used. The presented study is driven by the potential of polarized photon beams to probe the high energy region. This study is a contribution to the research program of the CEPC project being under development in China.