Training and test data for building a deep Belle II Flavor Tagger

The Belle II experiment at Tsukuba Japan creates entangled pairs of neutral B mesons in electron positron collisions. If one B meson is fully reconstructed, the remaining tracks and clusters originate from the other tag side B meson. A Flavor Tagger is a multivariate classifier that inspects these remaining tracks and classifies them as either originating from $B^{0}$ (q=1) or $\bar{B}^{0}$ (q=-1) meson. The published data set allows the training of a deep Flavor Tagger based on a realistic simulation of the Belle II detector.