2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/44760High-energy spin physics became a popular topic recently after the EMC finding for the proton's spin content. There exist unmeasured spin-dependent structure functions ($b_1$, $b_2$, $b_3$, and $b_4$) for spin-one hadrons such as the deuteron. The tensor structure function $b_1(x)$ could be measured by the proposed 15 GeV European Electron Facility. The measurement provides important clues to physics of non-nucleonic components in spin-one nuclei and to tensor structures on the quark-parton level.preprint MKPH-T-93-03, 9 pages, LATEX file, Proposal for the 15 GeV European Electron Facility ProjectHigh Energy Physics - PhenomenologyNuclear Theorytext