Fig. 6.

95% CL limits on the Higgs-mixing parameter $\kappa$, based on the $\mathrm{X}\mathrm{X}$ selection, as function of $m_{{\mathrm{Z}}_{\mathrm{D}}}$. The dashed black curve is the expected upper limit, with one and two standard-deviation bands shown in green and yellow, respectively. The solid black curve is the observed upper limit. The grey band corresponds to the excluded region around the $\mathrm{b}\overline{\mathrm{b}}$ bound states of ${\rm Y}$