2009/03/31 by Andrei Afanasev, Stanley J. Brodsky, Carl E. Carlson +1
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.1103/physrevd.81.034014
published as Phys.Rev.D81:034014,2010 · 9 pages, 8 figures; v2 has improved kinematic discussion
arxiv created 2009/07/29 · openalex publication_date 2010/02/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/02
We propose measurements of the deeply virtual Compton amplitude (DVCS) \ensuremathγ*\ensuremath→hh\ensuremathγ in the timelike t=(ph+p_h)2>0 kinematic domain which is accessible at electron-positron colliders via the radiative annihilation process e+e^\ensuremath-\ensuremath→hh\ensuremathγ. These processes allow the measurement of timelike deeply virtual Compton scattering for a variety of hh hadron pairs such as \ensuremathπ+\ensuremathπ^\ensuremath-, K+K^\ensuremath-, and DD as well as pp. As in the conventional spacelike DVCS, there are interfering coherent amplitudes contributing to the timelike processes involving C=\ensuremath- form factors. The interference between the amplitudes measures the phase of the C=+ timelike DVCS amplitude relative to the phase of the timelike form factors and can be isolated by considering the forward-backward e+\ensuremath↔e^\ensuremath- asymmetry. The J=0 fixed pole contribution which arises from the local coupling of the two photons to the quark current plays a special role. As an example we present a simple model.