2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/37308We present a measurement of CP-violating asymmetries in B0 -> pi+pi- decays based on 41.8 fb-1 data sample collected at the Y(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. From the asymmetry in the distribution of the time intervals between the two B meson decay points, we obtain the CP-violating asymmetry parameters S_pipi = -1.21 + 0.38 - 0.27 (stat) + 0.16 - 0.13 (syst) and A_pipi = +0.94 + 0.25 - 0.31 (stat) +- 0.09 (syst).8 pages, 2 figures, Flavor Physics and CP Violation (FPCP) 16-18 May 2002, University of Pennsylvania, Philadelphia, USAHigh Energy Physics - Experimenttext