Measurement of CP Asymmetries in B0-> KS pi0 pi0 Decays

TL;DR

This paper reports a preliminary measurement of time-dependent CP asymmetries in B0 decays to KS pi0 pi0, providing insights into CP violation with data from the BaBar experiment.

Contribution

First measurement of CP asymmetries in B0->KS pi0 pi0 decays using a large dataset from BaBar, with a detailed analysis of CP-violation parameters.

Findings

Measured CP-violation parameter S = 0.84 +/- 0.71 (stat) +/- 0.08 (syst)

Measured direct CP-violation parameter C = 0.27 +/- 0.52 (stat) +/- 0.13 (syst)

Results are consistent with Standard Model expectations within uncertainties.

Abstract

We present a preliminary measurement of the time-dependent CP asymmetry for the neutral B-meson decay into the CP = +1 final state KS pi0 pi0, with KS-> pi+ pi- and pi0-> gamma gamma. We use a sample of approximately 227 million B-meson pairs recorded at the Y(4S) resonance by the BaBar detector at the PEP-II B-Factory at SLAC. From a maximum likelihood fit we extract the mixing-induced CP-violation parameter S = 0.84 +/- 0.71(stat} +/- 0.08{syst) and the direct CP-violation parameter C = 0.27 +/- 0.52(stat) +/- 0.13(syst}, where the first uncertainty is statistical and the second systematic.