The experimental challenge of virtual compton scattering above 8 GeV

TL;DR

This paper reviews the experimental challenges and equipment needed for measuring virtual Compton scattering at energies above 8 GeV, focusing on Deeply Virtual Compton Scattering and high transverse momentum VCS.

Contribution

It provides a detailed discussion of the experimental issues and necessary apparatus for high-energy VCS measurements, emphasizing asymmetry measurements for DVCS.

Findings

Identification of key experimental challenges at energies above 8 GeV

Importance of asymmetry measurements for DVCS analysis

Discussion of equipment requirements for high-energy VCS

Abstract

We discuss the experimental issues confronting measurements of the Virtual Compton Scattering (VCS) reaction ep->ep gamma with electron beam energies 6-30 GeV. We specifically address the kinematics of Deeply Virtual Compton Scattering (Deep Inelastic Scattering, with coincident detection of the exclusive real photon nearly parallel to the virtual photon direction) and large transverse momentum VCS (High energy VCS of arbitrary Q**2, and the recoil proton emitted with high momentum transverse to the virtual photon direction). We discuss the experimental equipment necessary for these measurements. For the DVCS, we emphasize the importance of the Bethe-Heitler-Compton interference terms that can be measured with the electron-positron (beam charge) asymmetry, and the electron beam helicity asymmetry.