Measurement of CP -violation asymmetries in D 0 → K 0 S π + π −

Abstract

We report a measurement of time-integrated CP-violation asymmetries in the resonant substructure of the three-body decay D0→K0Sπ+π− using CDF II data corresponding to 6.0 fb−1 of integrated luminosity from Tevatron p¯p collisions at √s=1.96 TeV. The charm mesons used in this analysis come from D*+(2010)→D0π+ and D*−(2010)→¯¯¯D0π−, where the production flavor of the charm meson is determined by the charge of the accompanying pion. We apply a Dalitz-amplitude analysis for the description of the dynamic decay structure and use two complementary approaches, namely, a full Dalitz-plot fit employing the isobar model for the contributing resonances and a model-independent bin-by-bin comparison of the D0 and ¯¯¯D0 Dalitz plots. We find no CP-violation effects and measure an asymmetry of ACP=(−0.05±0.57(stat)±0.54(syst))% for the overall integrated CP-violation asymmetry, consistent with the standard model prediction.