"Figure 9a" of "Search for nonresonant pair production of Higgs bosons in the $b\bar{b}b\bar{b}$ final state in $pp$ collisions at $\sqrt{s}= 13$ TeV with the ATLAS detector"

Distributions of the reconstructed m_HH in data (shown by the black points), the estimated background (shown by the yellow histograms) in the VBF signal region with |Δη_HH| < 1.5.
The hatching shows the total uncertainty of the background estimate.
The distribution of the expected background is obtained using the best-fit values of the nuisance parameters in the fit to the data with the background-only hypothesis.
Distributions for three choices of couplings are shown: the SM, κ_λ= 6, and κ_2V = 0 (with all other couplings set to their SM values in the last two models), scaled so as to be visible on the plot.
The lower panels show the ratio of the observed data yield to the predicted background in each bin.
Events in the overflow bins are counted in the yields of the final bins.
In the HEPData entry, the raw value per histogram bin is provided, while in the published paper the values in the histogram are scaled by the bin width.