2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/48596We start with a brief presentation of the Standard Model and the weak neutral current, in view of a discussion of parity-violation in electron-hadron electroweak interactions. We then discuss some limitations of this model, motivating the consideration of larger frameworks such as grand-unification and supersymmetry. We also comment about the possible effects of additional light neutral gauge bosons.34 pages, Latex, no figures. Based in particular on a talk at the Conference ``Parity Violation in Electron-Hadron Electroweak Interactions'' (oct. 1997, Paris)High Energy Physics - Phenomenologytext