The impact of beamstrahlung on precision measurements at CLIC

TL;DR

This paper evaluates the limitations of common beamstrahlung approximations at high-energy colliders like CLIC, introducing an exact numerical model and analyzing its impact on precision measurements of new physics, such as Kaluza-Klein lepton production.

Contribution

It provides an exact numerical solution for beamstrahlung effects at CLIC and compares it with existing approximations, highlighting their failure at very high energies.

Findings

Approximate treatments of beamstrahlung fail at high energies.

Exact numerical modeling offers more accurate predictions.

Beamstrahlung significantly affects precision measurements.

Abstract

We review two commonly used approximate treatments of beamstrahlung at lepton colliders. We discuss the applicability of those approximations and show that they are bound to fail at very high energy $e^+e^-$ colliders such as CLIC. We model the beamstrahlung effects at CLIC by an exact numerical solution to the evolution equation for beamstrahlung and compare to the two approximations. We also discuss the impact of beamstrahlung on precision measurements of new physics parameters. As an illustration we consider Kaluza-Klein lepton production in Universal Extra Dimensions and study the deterioration of the endpoint lepton energy spectrum caused by beamstrahlung.