Absolute Measurements of Branching Fractions of Cabibbo-Suppressed Hadronic $D^{0(+)}$ Decays Involving Multiple Pions

By analyzing $e^{+}{e}^{-}$ annihilation data with an integrated luminosity of $2.93\mathrm{f}{\mathrm{b}}^{-1}$ collected at the center-of-mass energy $\sqrt{s}=$ 3.773 GeV with the BESIII detector, we present the first absolute measurements of the branching fractions of twenty Cabibbo-suppressed hadronic $D^{0(+)}$ decays involving multiple pions. The largest four branching fractions obtained are $\mathcal{B}(D^0\to {\pi }^{+}{\pi }^{-}{\pi }^0)=(1.343\pm {0.013}_{\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t}}\pm {0.016}_{\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{t}})\mathrm{\%}$, $\mathcal{B}(D^0\to {\pi }^{+}{\pi }^{-}2{\pi }^0)=(0.998\pm {0.019}_{\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t}}\pm {0.024}_{\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{t}})\mathrm{\%}$, $\mathcal{B}(D^{+}\to 2{\pi }^{+}{\pi }^{-}{\pi }^0)=(1.174\pm {0.021}_{\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t}}\pm {0.021}_{\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{t}})\mathrm{\%}$, and $\mathcal{B}(D^{+}\to 2{\pi }^{+}{\pi }^{-}2{\pi }^0)=(1.074\pm {0.040}_{\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t}}\pm {0.030}_{\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{t}})\mathrm{\%}$. The $CP$ asymmetries for the six decays with highest event yields are also determined.