Fig. 28.

Exclusion limits on $\mathit{\sigma }{}^{\prime }/{\mathit{\sigma }}_{\mathrm{SM}}$ for a second Higgs-boson-like state produced with gluon–gluon fusion only (top) or VBF and VH only (bottom) taking the observed state at 125$\text{GeV}$as part of the background. The shading indicates a window with a width of 10 GeV, centred at the best-fit mass, where the expected sensitivity to a second Higgs boson is severely degraded due to the presence of the already observed state