# Figure 3

 Invariant-mass distributions of $\DtoKpi$ candidates (andcharge conjugates) for $0< \pt< 0.5~\gev/c$. The left panel displaysthe invariant-mass distribution of all opposite-sign K$\pi$ pairs (or unlike sign, ULS in the legend) together with thebackground distribution estimated with the track-rotation technique. The right panel shows the invariant-mass distributions after subtraction of the background from the track-rotation technique. The blue solid line shows the total fit function as described in the text and the grey dashed line is the residual background after the subtraction of the background from the track-rotation technique.