Radiative corrections and Monte Carlo tools for low-energy hadronic cross sections in $e^+ e^-$ collisions

TL;DR

This paper reviews and compares Monte Carlo simulation tools used for calculating low-energy hadronic cross sections in electron-positron collisions, focusing on their approaches and differential cross section results relevant for experimental and theoretical analyses.

Contribution

It provides a detailed comparison of several Monte Carlo codes for low-energy e+e- scattering, highlighting differences and similarities in their approaches and results.

Findings

Differential cross sections vary among the Monte Carlo tools.

The study informs the choice of tools for dispersive evaluations.

Insights into the effects included in different simulation codes.

Abstract

We present the results of Phase I of an ongoing review of Monte Carlo tools relevant for low-energy hadronic cross sections. This includes a detailed comparison of Monte Carlo codes for electron-positron scattering into a muon pair, pion pair, and electron pair, for scan and radiative-return experiments. After discussing the various approaches that are used and effects that are included, we show differential cross sections obtained with AfkQed, BabaYaga@NLO, KKMC, MCGPJ, McMule, Phokhara, and Sherpa, for scenarios that are inspired by experiments providing input for the dispersive evaluation of the hadronic vacuum polarisation.