2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/49158Semi-inclusive electron scattering provides a powerful tool with which to study the spin and flavor distributions in the proton. Greater kinematic coverage at the proposed Electron-Polarized Ion Collider facility will enable the valence d/u ratio to be determined at large x through pion production. At small x, pion production can be used to extract the d-bar/u-bar ratio, complementing existing semi-inclusive measurements by HERMES, and Drell-Yan data from Fermilab. Asymmetries in heavier quark flavors can also be probed by tagging strange and charm hadrons in the final state.15 pages, 6 figures, presented at the Electron-Polarized Ion Collider Workshop, IUCF, April 1999High Energy Physics - PhenomenologyHigh Energy Physics - ExperimentNuclear ExperimentNuclear Theorytext