2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/48299The first three coefficients of the Taylor's series expansion of the vector pion form factor as a function of the momentum transfer are evaluated using experimental data on the pion form factor and the P-wave pi pi phase shifts. The real part of the form factor as a function of energy is also calculated by dispersion relation. Comparisons these results with Chiral Perturbation Theory and unitarized models are given.12 pages, LatexHigh Energy Physics - Phenomenologytext