Invariant-mass distribution of e$\Xi$ pairs for $\Xi_{\rm c}^0 \rightarrow e \, \Xi \, \nu_{\rm e}$ in $4 < p_{\rm T} < 6$ GeV/$c$, in the high-(left) and low-(right) multiplicity classes. The blue-filled distribution shows the total fit and the coloured lines indicate the different sources contributing to the fit.