Search for B → (ρ/ω)γ decays at BABAR

Citation

Piatenko, Timofei (2009) Search for B → (ρ/ω)γ decays at BABAR. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/JFX3-1629. https://resolver.caltech.edu/CaltechETD:etd-08252008-225854

Abstract

We present the results of the search for the decays ß^(0/±) ? ?^(0/±)? (previously observed) and ß⁰ ? ?? (for which currently only an upper limit exists). Together with ß ? K^*? decays, B ? (?/?)? allow us to measure the ratio of CKM-matrix elements |V_td/V_ts|. The analysis is based on the full BaBar dataset of 424.35 fb^-1, corresponding to 465 million BB pairs, and makes heavy use of multivariate classification techniques based on decision trees. We find ßR(B ? ?^±? ) = (1.20+0.42-0.38±0.20)×10^-6, ßR(B ? ?⁰?)= (0.95+0.23-0.21 ±0.06)×10^-6, and ßR(B ? ??)=(0.51+0.27-0.24±0.10)×10^-6, where the first error is statistical and the second is systematic. We do not observe a statistically significant signal in the latter channel and set an upper limit at ßR(B ? ??) < 0.9 × 10^-6 (90% C.L.). We also measure the isospin and SU(3)_F violating quantities ?(B⁺ ? ?⁺?)/2?(B⁰ ? ?⁰?) - 1 = -0.43+0.25-0.22±0.10 and ?(B ? ??)/?(B⁰ ? ?⁰?) - 1 = -0.49+0.30-0.27±0.10.

Thesis Files