Measurement of the CP-violating asymmetries in B0→K0sπ0 and of the branching fraction B0→K0π0

Abstract

We present a measurement of the time-dependent C P -violating asymmetries in B 0 → K 0 S π 0 decays based on 383 × 10 6 Υ ( 4 S ) → B ¯¯¯ B events collected by the BABAR experiment at the PEP-II asymmetric-energy B Factory at the Stanford Linear Accelerator Center. We measure the direct C P -violating asymmetry C K 0 S π 0 = 0.24 ± 0.15 ± 0.03 and the C P -violating asymmetry in the interference between mixing and decay S K 0 S π 0 = 0.40 ± 0.23 ± 0.03 , where the first errors are statistical and the second are systematic. On the same sample, we measure the decay branching fraction, obtaining B ( B 0 → K 0 π 0 ) = ( 10.3 ± 0.7 ± 0.6 ) × 10 − 6 .