2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/39291We discuss possible studies of parton distributions at the proposed 50-GeV PS facility. First, comments are given in general on the importance of large-x physics for finding new physics. Second, polarized deuteron reactions are discussed in connection with new structure functions which are specific for a spin-1 hadron. Third, if the polarized proton-deuteron Drell-Yan process is studied at the facility, it could provide information on the light-antiquark flavor asymmetry in the polarized distributions.1+6 pages LATEX2e, amsmath.sty, epsfig.sty, wrapfig.sty, 1 eps figure. Talk given at the Workshop on "Di-lepton Experiments at 50-GeV PS", KEK, Japan, Oct.29-30, 1999, to be published in proceedings. Complete postscript file is available at http://www-hs.phys.saga-u.ac.jp Email: kumanos@cc.saga-u.ac.jpHigh Energy Physics - PhenomenologyHigh Energy Physics - ExperimentNuclear Theorytext