ATLAS Collaboration
Post-fit distributions of $\Delta\Phi_{jj}$ for events in the combined tight (T), medium (M), and loose (L) analysis regions within the invariant diphoton mass window $m_{\gamma\gamma}\,{\in}\,[120, 130]\,\mathrm{GeV}$. The signal and background yields are fixed to the best-fit values from the $a_L$ interpretations. Contributions from the three regions are summed, weighted by $ln(1 + S/B)$, where $S$ and $B$ are the best-fit signal and background yields, respectively. The combined distribution is obtained by multiplying all Tight (T), Medium (M), and Loose (L) category yields by the category weights 0.7617, 0.1736, and 0.02262, respectively, before summing across the categories. The lower panels show the background-subtracted data compared with the best-fit VBF prediction $(a_{L}=1.1)$ and two BSM (up/down) scenarios corresponding to the two POI values excluded at exactly 95% CL by fits using only shape information. The BSM weights are (2.049, 0.3904), (0.6397, 0.09287), and (0.09047, 0.01277) for the up/down scenario in each of the T, M and L categories.