# Figure 1

 Cluster shower shape (top panel) and invariant mass (bottom panel) distributions for $8< E< 16$ GeV and $N_{\rm LM}=2$ compared between reconstructed $\pi^{0}$ candidates in data and clusters originating from $\pi^{0}$ in HIJING for $0$-$10$% Pb-Pb collisions. The distributions are shown after applying the energy-dependent selections on $\sigma^2_{\rm long}$ and $M_{\gamma\gamma}$.