"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.

数据中重建的双希格斯玻色子不变质量（reconstructed m_HH）的分布以黑色点表示，矢量玻色子融合（Vector Boson Fusion, VBF）信号区域内满足|Δη_HH| < 1.5的事件的预估本底分布以黄色直方图表示。
阴影区域代表本底预估的总不确定度。
预期本底分布通过仅背景假设下对数据进行拟合时得到的讨厌参数（nuisance parameters）最优拟合值获得。
展示了三种耦合常数选择下的分布：标准模型（Standard Model, SM）、κ_λ=6以及κ_2V=0（后两种模型中其余耦合参数均设为其标准模型取值），所有分布均经缩放以在图中清晰呈现。
下方子图展示了每个统计箱内观测数据产额与预估本底的比值。
溢出箱中的事件将被计入最后一个统计箱的产额中。
在HEPData条目中，提供了每个直方图箱的原始数值；而在已发表论文中，直方图内的数值已按箱宽进行缩放。