Observation of the Singly Cabibbo-Suppressed Decay $D^+\to\omega\pi^+$ and Evidence for $D^0\to\omega\pi^0$

摘要: Based on 2.93 fb−1 e+e− collision data taken at center-of-mass energy of 3.773 GeV by the BESIII detector, we report searches for the singly Cabibbo-suppressed decays D+→ωπ+ and D0→ωπ0. A double tag technique is used to measure the absolute branching fractions B(D+→ωπ+)=(2.79±0.57±0.16)×10−4 and B(D0→ωπ0)=(1.17±0.34±0.07)×10−4, with statistical significances of 5.5σ and 4.1σ, respectively. We also present measurements of the absolute branching fractions for the related ηπ decay modes. We find B(D+→ηπ+)=(3.07±0.22±0.13)×10−3 and B(D0→ηπ0)=(0.65±0.09±0.04)×10−3, which are consistent with the current world averages. The first and second uncertainties are statistical and systematic, respectively.