Study of $\chi_{b1,2}(2P) \to \omega \Upsilon(1S)$ transitions in $\Upsilon(3S) \to \gamma \chi_{b1,2}(2P)$ decays at BaBar

Abstract

Results are presented on $\chi_{b1,2}(2P) \to \omega \Upsilon(1S)$ transitions from $e^+e^- \to \Upsilon(3S) \to \gamma \chi_{b1,2}(2P)$ decays. The data were collected with the BaBar detector at the PEP-II asymmetric-energy $e^+e^-$ collider at SLAC. The integrated luminosity of the data sample is 28.0 fb$^{-1}$, corresponding to $121.3 \times 10^6$ $\Upsilon(3S)$ decays. Signals of $\chi_{b1,2}(2P)$ are observed over a negligible background. Improved precision measurements of branching fractions are obtained. First measurements of the $\chi_{b1,2}(2P)$ angular distributions are performed. No evidence is found for the presence of a $\chi_{b0}(2P) \to \omega \Upsilon(1S)$ decay mode.