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Now you can start using your data and load three different NumPy arrays! One corresponds to the VBF signal and the other two will represent the Higgs boson production via the strong interaction processes (in jargon, QCD)
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that will be used as a merged background.
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The gain due to the splitting of a node A into the nodes B1 and B2, which depends on the chosen cut, is given by ΔI=I(A)-I(BB1)-I(B2), where I denotes the adopted metric (G or E, in case of the Gini index or cross-entropy introduced above). By varying the cut, the optimal gain may be achieved.
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