2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/48319Using recent experimental data and various theoretical calculations on form factors, we reanalyze the effective parameters $a_1$ and $a_2$ and their ratio.6 pages, presented by K.-C. Yang at ``The Fourth International Workshop on Particle Physics Phenomenology", Kaohsiung, Taiwan, 18-21 January 1998High Energy Physics - Phenomenologytext