Observation of a Neutral Structure near the $D\barD^*$ Mass Threshold in $e^+e^− \to (D ¯D )0π0 at ps = 4.226 and 4.257 GeV

neutral structure in the?DDˉ??system around the?DDˉ??mass threshold is observed with a statistical significance greater than 10σ?in the processes?e+e?→D+D??π0+c.c.?and?e+e?→D0Dˉ?0π0+c.c.?at?s√?= 4.226 and 4.257 GeV in the BESIII experiment. The structure is denoted as?Zc(3885)0. Assuming the presence of a resonance, its pole mass and width are determined to be (3885.7+4.3?5.7(stat)±8.4(syst)) MeV/c2?and (35+11?12(stat)±15(syst)) MeV, respectively. The Born cross sections are measured to be?σ(e+e?→Zc(3885)0π0,Zc(3885)0→DDˉ?)=(77±13(stat)±17(syst)) pb at 4.226 GeV and (47±9(stat)±10(syst)) pb at 4.257 GeV. The ratio of decay rates?B(Zc(3885)0→D+D??+c.c.)B(Zc(3885)0→D0Dˉ?0+c.c.)?is determined to be0.96±0.18(stat)±0.12(syst), consistent with no isospin violation in the process?Zc(3885)0→DDˉ?.