2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/81385The directed flow of protons and positive pions have been studied in 158 A GeV Pb + Pb collisions. A directed flow analysis of the rapidity dependence of the average transverse momentum projected onto the reaction plane is presented for semi-central collisions with impact parameters of approximately 8 fm, where the flow effect is largest. The magnitude of the directed flow is found to be significantly smaller than observed at AGS energies and than RQMD model predictions.5 pages, Latex, including 3 eps figures, submitted to Phys.Rev.Lett. Resubmitted with revised text and figuresNuclear Experimenttext