Fig. 4.

Four-lepton mass distribution, $m_{4\ell }$, up to $500\text{GeV}$ with $4\text{GeV}$ bin size (upper) and in the low-mass range with $2\text{GeV}$ bin size (lower). Points with error bars represent the data and stacked histograms represent the expected distributions for the signal and background processes. The SM Higgs boson signal with $m_{\mathrm{H}}=125\text{GeV}$, denoted as $\mathrm{H}(125)$, the $\mathrm{Z}\mathrm{Z}$ and rare electroweak backgrounds are normalized to the SM expectation, the $\mathrm{Z}$+X background to the estimation from data