Measurement of time-dependent CP asymmetry in B0→K0Sπ0γ decays

Abstract

We measure the time-dependent C P asymmetry in B 0 → K 0 S π 0 γ decays for two regions of K 0 S − π 0 invariant mass, m ( K 0 S π 0 ) , using the final BABAR data set of 467 × 10 6 B ¯¯¯ B pairs collected at the PEP-II e + e − collider at SLAC. We find 339 ± 24 B 0 → K * 0 γ candidates and measure S K ∗ γ = − 0.03 ± 0.29 ± 0.03 and C K ∗ γ = − 0.14 ± 0.16 ± 0.03 . In the range 1.1 < m ( K 0 S π 0 ) < 1.8 GeV / c 2 we find 133 ± 20 B 0 → K 0 S π 0 γ candidates and measure S K 0 S π 0 γ = − 0.78 ± 0.59 ± 0.09 and C K 0 S π 0 γ = − 0.36 ± 0.33 ± 0.04 . The uncertainties are statistical and systematic, respectively.