"Figure_005-c_obs_contour" of "Search for dark matter particles in W$^+$W$^-$ events with transverse momentum imbalance in proton-proton collisions at $\sqrt{s}$ = 13 TeV"

Contour of the 95% CL observed upper limits representing $\sigma / \sigma_{theory} = 1$ for the dark Higgs model in the ($m_{s}$, $m_{Z'}$) plane for $m_{\chi} = 200 GeV$.

针对暗希格斯模型（dark Higgs model），当暗物质粒子质量$m_chi=200 ext{GeV}$时，于$(m_s, m_{Z'})$平面内，表征截面与理论截面之比$sigma/sigma_{ ext{theory}}=1$的95%置信水平实验观测上限的等高线。