Accessing the longitudinally polarized photon content of the proton

2004/05/31 by Asmita Mukherjee, A. Mukherjee, Cristian Pisano +1
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ex #hep-ph

paper · pdf · doi:10.1103/physrevd.70.034029

published as Phys.Rev.D70:034029,2004 · Version to appear in PRD

openalex publication_date 2004/08/30 · arxiv created 2004/08/31 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

We investigate the QED Compton process in longitudinally polarized lepton-proton scattering both in the elastic and inelastic channels and show that the cross section can be expressed in terms of the polarized equivalent photon distribution of the proton. We provide the necessary kinematical constraints to extract the polarized photon content of the proton using this process at HERMES, COMPASS, and eRHIC. We also discuss the suppression of the major background process coming from virtual Compton scattering. We point out that such an experiment can give valuable information on g₁(x_B,Q²) in the small x_B, broad Q² region at the future polarized collider eRHIC and especially in the lower Q², medium x_B region in fixed target experiments.

Citations

• Manifestly covariant analysis of the QED Compton processin ep→ e γ p and e p → e γ X
• Evidence for Quark-Hadron Duality in the Proton Spin AsymmetryA1
• Delineating the polarized and unpolarized photon distributions of the nucleon in eN collisions