2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/97778Results on the cross section measurement of Z boson pair-production at LEP are presented. The more general case of neutral-current four-fermion production and the particular case of ZZ events enriched in b quarks are also discussed. All the results agree with the Standard Model predictions.To appear in the proceedings of ICHEP 2000, Osaka, Japan, July 27th-August 2nd, 2000High Energy Physics - Experimenttext