Photon-odderon interference in exclusive χc charmonium production at the Electron-Ion Collider

Abstract

Exclusive C=+1 scalar, axial-vector, and tensor quarkonium production in high-energy electron-proton scattering requires a C-odd t-channel exchange of a photon or a three-gluon ladder. We derive the expressions for the corresponding amplitudes. The relative phase of the photon vs three-gluon exchange amplitudes is determined by the sign of the light-front matrix element of the eikonal color current operator dabcJ+aJ+bJ+c at moderate x, and is not affected by small-x QCD evolution. Model calculations predict constructive interference, which is particularly strong for momentum transfer |t|∼1  GeV2 where the cross section for χcJ production exceeds that for pure photon exchange by up to a factor of 4. Exclusive χcJ electroproduction at the high luminosity Electron-Ion Collider occurs with well measurable rates and measurements of these processes should find evidence for the perturbative odderon exchange. We also compute the total electroproduction cross section as a function of energy and provide first estimates of the number of χcJ events per month at the Electron-Ion Collider design luminosity. Published by the American Physical Society 2024