Figure 49

Distribution of the ratios of the $\pi^{0}$ meson masses found by a fit in the narrow interval ($\mu^{\text{fit}}_n$) of 70 $< \mu_\pi^{0}< $ 220 MeV/$c^2$ with respect to the standard range ($\mu^{\text{fit}}_s$) of 50 $< \mu_\pi^{0}< $ 300 MeV/$c^2$, for cells located behind the zones with more material (filled distribution) and for the other cells (blue distributions) for SMs 0$-$17. The latter histogram is fit with a Gaussian (red).