Master integrals for $e^{+}e^{-}\rightarrow2\gamma$ process at large energies and angles

TL;DR

This paper computes two-loop master integrals for the electron-positron to two-photon process at high energies and angles, using advanced multiloop techniques and expressing results via Goncharov's polylogarithms.

Contribution

It introduces a novel calculation of two-loop massive master integrals with series expansion in electron mass, employing modern multiloop methods and expressing results in terms of Goncharov's polylogarithms.

Findings

Explicit series expansion of master integrals in electron mass.

Expression of coefficients via Goncharov's polylogarithms.

Application of modern multiloop techniques to a relevant QED process.

Abstract

We calculate two-loop massive master integrals for $e^{+}e^{-}\rightarrow2\gamma$ in terms of generalized power series with respect to electron mass. The coefficients of this series are expressed via Goncharov's polylogarithms. Our approach exploits a number of modern multiloop methods: IBP reduction, differential equations for master integrals, Frobenius method, reduction to $\epsilon$-form, and DRA method.