2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/97795The D^0 mixing parameter y = Delta Gamma/2 Gamma was determined by measuring the D^0 lifetime separately for the K^-pi^+ decay mode and the K^-K^+ decay mode with 12.4 fb^{-1} of data collected by the BABAR experiment in 2001. Backgrounds were suppressed with the D^* --> D^0pi^+ decay and particle identification. The following preliminary result was obtained: y = (-1.0 +/- 2.2 (stat) +/- 1.7 (syst))%.14 pages, 3 figures, contributed paper to the 9th Heavy Flavor SymposiumHigh Energy Physics - Experimenttext