# Figure 1

 Top panels: Invariant mass distribution of opposite-sign pairs from the same event and mixed events for the $0$--$10$\% (left) and $60$--$90$\% (right) centrality classes in \PbPb collisions at $\snn = 5.02$~TeV. Bottom panels: Background-subtracted invariant mass distributions in comparison with the expected Monte Carlo signal shape.