# Figure 4

 Ratio of the inclusive electron yield to the one of background electrons obtained with the invariant mass method in Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV in 0-10% (left), 10-20% (middle) and 20-40% (right) centrality classes. The vertical error bars and open boxes represent the statistical and systematic uncertainties, respectively.