Raw invariant mass distribution of $\rm p\uppi^{-}$ ($\rm \overline{p}\uppi^{+}$) pairs used to obtain the $\Lambda$ ($\overline{\Lambda}$) candidates for Pb--Pb collisions at $\sqrt{s_{\rm NN}}=5.02$ TeV in the 0--5\% centrality range. The dashed lines represent the selection width used in the analysis. Note that the mean value of the distribution is slightly shifted from the rest mass of $\Lambda$ ($\overline{\Lambda}$) by $\sim 1$ MeV/$c^2$ due to imperfectionsin the energy loss corrections that are applied in the track reconstruction.