The Hadronic Final States in Deep Inelastic $e\gamma$ Scattering at a Future e^+e^- Linear Collider

TL;DR

This paper investigates the energy flow in gamma-gamma events at different energies using HERWIG simulations, emphasizing the importance of understanding the forward region for accurate photon structure function measurements at future e+e- colliders.

Contribution

It provides a comparative analysis of energy flow distributions at LEP1 and future collider energies, highlighting the significance of forward region modeling for photon structure studies.

Findings

Energy flow distributions are similar at different beam energies.

Understanding the forward region is crucial for photon structure function analysis.

Forward region modeling impacts the extraction of $F_2^{\gamma}$.

Abstract

Energy flow distributions from tagged $\gamma\gamma$ events generated with HERWIG are presented for $E_{beam} = 45.6$ GeV (LEP1) and $E_{beam} = 175$ GeV (top-quark threshold at a future e^+e^- Linear Collider). They have very similar shapes regardless of the beam energy. Using the present knowledge of the LEP $F_2^{\gamma}$ analyses, it is forseen that the understanding of the hadronic response of the forward region of the LC detector is vital to the development of the final state models in $\gamma\gamma$ Monte Carlos. Such models are relied upon to extract $F_2^{\gamma}$ from the data, and hence understanding the forward region well may be crucial in the determination of whether or not a low-$x$ rise exists in the photon structure function.