2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/176623We study the Nambu-Jona-Lasinio model with light and heavy quarks in a relativistic approach. We emphasize relevant regularization issues as well as the transition from light to heavy quarks. The approach of the electromagnetic meson form factor to the Isgur-Wise function in the heavy quark limit is also discussed.5 pages, 2 figures. Talk given at the IV International Conference on Quarks and Nuclear Physics (QNP06), Madrid, June 5th - 10th 2006High Energy Physics - Phenomenologytext