The correction factor $f_{+-}(\Delta\eta,\Delta\varphi)$ for the 5$\%$ most central Pb--Pb collisions, extracted from the single particle tracking efficiencies $\varepsilon(\eta,\varphi,p_{\rm T})$ and the acceptance terms $\alpha(\Delta\eta,\Delta\varphi)$ (see text for details). | ![](https://alice-publications.web.cern.ch/sites/default/files/papers/476/correction-2662.png ) |