2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/41196Reliable knowledge of parton distribution functions is crucial for many searches for new physics signals in the next generation of experiments. Presently, there remain a number of open questions regarding the PDF's and their uncertainties. We briefly discuss these issues, and consider aspects where a future high-precision fixed-target experiment might contribute.3 pages. Contribution to Snowmass 2001 workshop, E5 groupHigh Energy Physics - Phenomenologytext