First measurement of the $B^{+}\to {\pi }^{+}{\pi }^0{\pi }^0$ branching fraction and \textit{CP} asymmetry

Abstract

We study $B^{+}\to {\pi }^{+}{\pi }^0{\pi }^0$ using 711 ${\mathrm{fb}}^{-1}$ of data collected at the ${\rm Y}(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider. We measure an inclusive branching fraction of $(19.0\pm 1.5\pm 1.4)\times 10^{-6}$ and an inclusive \textit{CP} asymmetry of $(9.2\pm 6.8\pm 0.7)\%$, where the first uncertainties are statistical and the second are systematic; and a $B^{+}\to \rho (770{)}^{+}{\pi }^0$ branching fraction of $(11.2\pm 1.1\pm 0.9_{-1.6}^{+0.8})\times 10^{-6}$, where the third uncertainty is due to possible interference with $B^{+}\to \rho (1450{)}^{+}{\pi }^0$. We present the first observation of a structure around 1 GeV/$c^2$ in the ${\pi }^0{\pi }^0$ mass spectrum, with a significance of 6.4$\sigma$, and measure a branching fraction to be $(6.9\pm 0.9\pm 0.6)\times 10^{-6}$. We also report a measurement of local \textit{CP} asymmetry in this structure.

arXiv comment12 pages, 2 figures

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Cited by in corpus (1)

• Phenomenological analysis of charmless $B\to PV$ decays in the modified perturbative QCD approach