Fig. 27.

Exclusion limit on the signal strength, $\mathit{\sigma }{}^{\prime }/{\mathit{\sigma }}_{\mathrm{SM}}$, for a second Higgs-boson-like state with SM couplings taking the observed state at 125$\text{GeV}$as part of the background. The shading indicates a window with a width of 10$\text{GeV}$, 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