{\bf Distribution of $ D ^0$ $ D ^0$ $\pi ^+$ mass}. Distribution of $ D ^0$ $ D ^0$ $\pi ^+$ mass where the contribution of the nondash-$ D ^0 $ background has been statistically subtracted. The result of the fit with the twodash-component function described in the text is overlaid. The $ D ^{*+} D ^0 $ and $ D ^{*0} D ^+ $ thresholds are indicated with the vertical dashed lines. The horizontal bin width is indicated on the vertical axis legend. Inset shows a zoomed signal region with fine binning scheme, Uncertainties on the data points are statistical only and represent one standard deviation, calculated as a sum in quadrature of the assigned weights from the backgrounddash-subtraction procedure.

Animated gif made out of all figures.

Parameters obtained obtained from the fit to the $ D ^0 D ^0 \pi ^+ $ mass spectrum. Signal yield, $N$, Breitdash--Wigner mass relative to $ D ^{*+} D ^0 $ mass threshold, $\updelta m_{\mathrm{BW}}$, and width, $\Gamma_{\mathrm{BW}}$, are listed. The uncertainties are statistical only.

Systematic uncertainties for the $\updelta m_{\mathrm{BW}}$ and $\Gamma_{\mathrm{BW}}$ parameters. The total uncertainty is calculated as the sum in quadrature of all components except for those related to the $\mathrm{J^P}$ quantum numbers assignment, which are handled separately.