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تسجيل مستخدم جديدThe Full Event Interpretation -- An exclusive tagging algorithm for the Belle II experiment
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The Full Event Interpretation is presented: a new exclusive tagging algorithm used by the high-energy physics experiment Belle II. The experimental setup of Belle II allows the precise measurement of otherwise inaccessible $B$ meson decay-modes. The Full Event Interpretation algorithm enables many of these measurements. The algorithm relies on machine learning to automatically identify plausible $B$ meson decay chains based on the data recorded by the detector. Compared to similar algorithms employed by previous experiments, the Full Event Interpretation provides a greater efficiency, yielding a larger effective sample size usable in the measurement.
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We present the results of the re-discovery of the decay $B^0 to pi^- ell^+ u_ell$ in 34.6 fb$^{-1}$ of Belle II data using hadronic $B$-tagging via the Full Event Interpretation algorithm. We observe 21 signal events on a background of 155 in a fit
to the distribution of the square of the missing mass, $M_{mathrm{miss}}^2$, with a significance of 5.69$sigma$, and determine a total branching fraction of (1.58 $pm$ 0.43$_{mathrm{stat}}$ $pm$ 0.07$_{mathrm{sys}}$) $times 10^{-4}$.
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