Light-front methods in next-generation eA physics at EIC

Abstract

The medium-energy Electron-Ion Collider design (root-s = 10-40 GeV/nucleon) enables measurements of deep-inelastic scattering on polarized light ions (deuterium D, helium-3) with detection of forward-moving spectator nucleons ("spectator tagging"). Such measurements can definitively address several outstanding questions of nuclear physics, such as neutron spin structure, the partonic structure of the bound nucleon, and the onset of coherent QCD phenomena in high-energy processes (shadowing, diffraction). Light-front methods are an essential tool in the theory and analysis of such measurements. We summarize (a) light-front nuclear structure in deep-inelastic eD scattering with spectator tagging (spectral functions, final-state interactions); (b) extraction of free neutron structure through on-shell extrapolation; (c) polarized eD scattering; (d) shadowing and diffraction in measurements with spectator nucleon tagging. We report results of an R&D project at Jefferson Lab aimed at developing the theoretical methods for spectator nucleon tagging at EIC and demonstrating the feasibility of such measurements through detailed process simulations.