Two-loop radiative corrections to $e^+ e^-\rightarrow \gamma\gamma^*$ cross section

TL;DR

This paper calculates two-loop radiative corrections to the e+ e- to gamma gamma* process, enhancing the precision of theoretical predictions crucial for muon anomalous magnetic moment measurements.

Contribution

It provides a detailed calculation of second-order radiative corrections for e+ e- annihilation into photons, improving theoretical accuracy for muon g-2 studies.

Findings

Two-loop corrections can be derived from one-loop results using soft and collinear factorization.

The corrections help refine the theoretical estimate of hadron vacuum polarization contributions.

Results facilitate more precise comparisons between theory and experiment in muon g-2 measurements.

Abstract

The increasing accuracy of current and planned experiments to measure the anomalous magnetic moment of the muon requires more precision and reliability of its theoretical calculation. For this purpose, we calculate the differential cross section for the process of annihilation of an electron-positron pair into two photons, one of which is virtual, accompanied by the emission of soft photons, taking into account radiative corrections of the order $\alpha^2$. The results obtained can be used to improve the accuracy of calculating the contribution of the hadron vacuum polarization to the muon anomalous moment. It is shown that all logarithmically amplified two-loop corrections can be easily found using modern theorems of soft and collinear factorizations and available one-loop results.