Fig. 7.

Born-level fiducial cross sections in bins of $m_{\ell \ell }$ for the combination of the electron-pair and muon-pair channels. The middle plot shows the ratios of the values from the individual channels to the combined values, where the error bars on the individual-channel measurements represent the total uncertainty uncorrelated between bins. The light-blue band represents the data statistical uncertainty on the combined value. The dark-blue band represents the total uncertainty (statistical and systematic), except for the uncertainty of 2.8 % on the integrated luminosity, which is fully correlated between channels and among all $m_{\ell \ell }$ bins. The ${\mathit{\chi }}^2$ per degree of freedom is given. The lower plot shows the pull, defined as the difference between the electron-pair and muon-pair values divided by the uncertainty on that difference. The fiducial regions to which these cross sections correspond are specified in Table 1. Note that $p_{\mathrm{T}}^{\ell \ell }$ is required to be greater than $45\mathrm{GeV}$ for $m_{\ell \ell }<46\mathrm{GeV}$