2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/43023Questions concerning the Bose-Einstein (BEC) and Fermi-Dirac (FDC) correlations of hadrons produced in $e^+e^-$ collisions are discussed. Among them the emitter dimension $r$ as a function of $\sqrt{s_{ee}}$ and the hadron mass, the extension of the BEC by including isospin invariance and the proposed relation between $r$ and the inter-atomic separation in Bose condensates.Invited talk given at the ISMD2003, 5-11 September 2003, Krakow, PolandHigh Energy Physics - Phenomenologytext