"Expected and observed limits on $g_\ell$" of "Search for dimuon resonance in the 35 to 75 GeV mass range using 140 fb$^{-1}$ of 13 TeV $pp$ collisions with the ATLAS detector"

Observed and expected 95% CL upper limits on the coupling between the $Z^\prime$ boson and leptons as a function of $m_{Z'}$, assuming $g_q=0.1$. Discontinuities correspond to the boundaries between different GP hyper-parameter regions. Vertical dashed lines indicate the mass points where the hyper-parameters are changed.