Measurement of branching fractions and mass spectra of B→Kππ γ

Abstract

We present a measurement of the partial branching fractions and mass spectra of the exclusive radiative penguin processes B→Kππγ in the range mKππ<1.8GeV/c2. We reconstruct four final states: K+π-π+γ, K+π-π0γ, KS0π-π+γ, and KS0π+π0γ, where KS0→π+π-. Using 232×106 e+e-→BB̄ events recorded by the BABAR experiment at the SLAC PEP-II asymmetric-energy storage ring, we measure the branching fractions B(B+→K+π-π+γ)=[2.95±0.13(stat)±0.20(syst)] ×10-5, B(B0→K+π-π0γ)=[4.07±0.22(stat)±0. 31(syst)]×10-5, B(B0→K0π+π-γ)=[1.85±0.21(stat) ±0.12(syst)]×10-5, and B(B+→K0π+π0γ)=[4. 56±0.42(stat)±0.31(syst)]×10-5. © 2007 The American Physical Society.