$2\gamma$ and $3\gamma$ annihilation as calibration processes for high energy $e^+ e^-$ colliders

TL;DR

This paper calculates differential cross sections and radiative corrections for high-energy electron-positron annihilation, focusing on large-angle photon emission, and confirms the applicability of the Drell-Yan form with structure functions.

Contribution

It provides the lowest-order radiative corrections and validates the Drell-Yan form for differential cross sections in high-energy $e^+ e^-$ annihilation.

Findings

Validation of Drell-Yan form with structure functions

Leading and next-to-leading order cross section calculations

Numerical estimations of radiative corrections

Abstract

Born differential cross sections and the lowest-order radiative correction to them are obtained in the kinematics of large-angle final photons emission in high-energy electron-positron annihilation processes. Taking into account possible emission of real soft and hard photons in collinear kinematics we show the validity of the Drell-Yan form of differential cross section with the nonsinglet structure functions of initial leptons. The leading and next-to leading contribution to the cross sections is obtained. The relevant numerical estimations are presented.