"Figure 12b" 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"

The expected and observed profile likelihood ratio scans for the κ_2V coupling modifier, shown by the solid black line, using the coupling modifier as the POIs.
The value of κ_λ is fixed to 1.
The dashed blue line shows the expected profile likelihood ratio, as obtained using a fit to the data with the background-only hypothesis.
The pink line indicates the 2σ exclusion boundary.

纯黑实线展示了以耦合修正因子为感兴趣参数（Parameter of Interest，POI）时，κ₂V耦合修正因子的预期与观测剖面似然比扫描结果。
κ_λ的取值固定为1。
蓝色虚线呈现了基于仅背景假设的数据拟合所得到的预期剖面似然比。
粉色线条代表2σ排除界限。