Figure 2

Left: Acceptance-times-efficiency for $\rm D_s^+$ mesons in the 10% most central Pb--Pb collisions. The efficiencies for prompt (solid lines) and feed-down (dotted lines) $\rm D_s^+$ mesons are shown. Also displayed, for comparison, the efficiency for prompt $\rm D_s^+$ mesons without PID selections (dashed lines). Right: Relative variation of the prompt $\rm D_s^+$-meson yield in the 0-10% centrality class as a function of the hypothesis on $\RAA^{\rm{feed-down}}/\RAA^{\rm prompt}$ for the B feed-down subtraction approach based on Eq. (2).