We have studied radiative B meson decays into higher kaonic resonances decaying into a two-body or three-body final state, using a data sample of 21.3 fb−1 recorded at the Υ(4S) resonance with the Belle detector at KEKB. For the two-body final state, we extract the B→K∗2(1430)0γ component from an analysis of the helicity angle distribution, and obtain B(B0→K∗2(1430)0γ)=(1.26±0.66±0.10)×10−5. For the three-body final state, we observe a B→Kππγ signal that is consistent with a mixture of B→K∗πγ and B→Kργ. This is the first time that B→K∗πγ and B→Kργ have been observed separately. We find their branching fractions to be B(B→K∗πγ;MK∗π<2.0GeV/c2)=(5.6±1.1±0.9)×10−5 and B(B→Kργ;MKρ<2.0GeV/c2)=(6.5±1.7+1.11.2)×10−5, respectively.
International Europhysics Conference on High-Energy Physics, Budapest, Hungary, 12 - 18 Jul 2001, pp.088