New Measurements of Time-Dependent CP-Violating Asymmetries in B0 -> KsKsKs and Ks pi0 gamma Decays at Belle

We present new measurements of CP-violation parameters in B0 -> KsKsKs and Ks pi0 gamma decays based on a sample of 275 x 10^6 BBbar pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB energy-asymmetric e+e- collider. One neutral B meson is fully reconstructed in one of the specified decay channels, and the flavor of the accompanying B meson is identified from its decay products. CP-violation parameters are obtained from the asymmetries in the distributions of the proper-time intervals between the two B decays. We obtain S_{KsKsKs} = +1.26 +/- 0.68(stat) +/- 0.18(syst), A_{KsKsKs} = +0.54 +/- 0.34(stat) +/- 0.08(syst), S_{Ks pi0 gamma} = -0.58 +0.46/-0.38(stat) +/- 0.11(syst), A_{Ks pi0 gamma} = +0.03 +/- 0.34(stat) +/- 0.11(syst). All results are preliminary.