"Correlation matrix Fig. 9d x Fig. 9d" of "Differential cross-sections for events with missing transverse momentum and jets measured with the ATLAS detector in 13 TeV proton-proton collisions"

Statistical correlations between $\Delta\phi_\text{jj}$ observable, $2\mu$ + jets region, VBF phase space (Figure 9d) and $\Delta\phi_\text{jj}$ observable, $2\mu$ + jets region, VBF phase space (Figure 9d).