2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/38196The total hadronic photon-photon cross-section measured by L3 and OPAL and the apparent discrepancy between the results are discussed. OPAL measurements of jet and charged hadron production in photon-photon scattering and preliminary H1 results on neutral pion production in photon-proton scattering are also presented. The mechanism of baryon number transfer in photon-proton interactions at HERA has been studied for the first time by H1.7 pages, 14 figures, uses ltwol2e.sty, submitted to Proceedings of ICHEP98, Vancouver, Canada, 22-30 July 1998High Energy Physics - Experimenttext