$\rho$ distributions for central Pb$-$Pb collisions at $\sqrtsNN=5.02$ TeV. Upper panel: ${\rm TT_{sig}}$ and ${\rm TT_{ref}}$ distributions, and the ${\rm TT_{ref}}$ distribution shifted by $\Delta\rho=1.7$ GeV/$c$ (Sec. 4.1). Lower panel: ratio of ${\rm TT_{ref}}$ and shifted ${\rm TT_{ref}}$ to ${\rm TT_{sig}}$ distribution. The mean ($\mu$) and RMS of the distributions are given in the legend. The vertical lines on the data points are the statistical uncertainties, and the shaded band on the ratio of the ${\rm TT_{sig}}$ over the shifted ${\rm TT_{ref}}$ distributions represents the systematic uncertainty of the procedure.