Time-dependent analysis of B^0 → K^0_Sπ^−π^^+γ decays and studies of the K^+π^−π^+ system in B^+ → K^+π^−π^+γ decays
We measure the time-dependent CP asymmetry in the radiative-penguin decay B^0→K^0_Sπ^−π^+γ, using a sample of 471×10^6 Υ(4S)→BB¯ events recorded with the BABAR detector at the PEP-II e^+e^− storage ring at SLAC. Using events with mKππ<1.8 GeV/c^2, we measure the branching fractions of B^+→K^+π^−π^+γ and B^0→K^0π^−π^+γ, the branching fractions of the kaonic resonances decaying to K^+π^−π^+, as well as the overall branching fractions of the B^+→ρ^0K^+γ, B^+→K^(*0)π^+γ and S-wave B^+→(Kπ)^(*0)_0π^+γ components. For events from the ρ mass band, we measure the CP-violating parameters SK^0_Sπ^+π^−γ=0.14±0.25±0.03 and CK^0_Sπ^+π^−γ=−0.39±0.20+0.03−0.02, where the first uncertainties are statistical and the second are systematic. We extract from this measurement the time-dependent CP asymmetry related to the CP eigenstate ρ^0K^0_S and obtain SK^0_(Sργ)=−0.18±0.32^(+0.06)_(−0.05), which provides information on the photon polarization in the underlying b→sγ transition.
Additional Information© 2016 American Physical Society. Received 19 December 2015; published 29 March 2016. We thank E. Kou for help throughout the analysis, especially with the computation of the dilution factor, and A. Le Yaouanc for valuable discussions. We are grateful for the extraordinary contributions of our PEP-II2 colleagues in achieving the excellent luminosity and machine conditions that have made this work possible. The success of this project also relies critically on the expertise and dedication of the computing organizations that support BABAR. The collaborating institutions wish to thank SLAC for its support and the kind hospitality extended to them. This work is supported by the U.S. Department of Energy and National Science Foundation, the Natural Sciences and Engineering Research Council (Canada), the Commissariat à l'Energie Atomique and Institut National de Physique Nucléaire et de Physique des Particules (France), the Bundesministerium für Bildung und Forschung and Deutsche Forschungsgemeinschaft (Germany), the Istituto Nazionale di Fisica Nucleare (Italy), the Foundation for Fundamental Research on Matter (Netherlands), the Research Council of Norway, the Ministry of Education and Science of the Russian Federation, Ministerio de Ciencia e Innovación (Spain), and the Science and Technology Facilities Council (United Kingdom). Individuals have received support from the Marie-Curie IEF program (European Union), the A. P. Sloan Foundation (USA) and the Binational Science Foundation (USA–Israel).
Published - PhysRevD.93.052013.pdf