PAO-TI CHANGWEI-SHU HOU2022-04-252022-04-25202110298479https://www.scopus.com/inward/record.uri?eid=2-s2.0-85115637472&doi=10.1007%2fJHEP09%282021%29075&partnerID=40&md5=ffb6af6be47e6a4382f6a12b944f6495https://scholars.lib.ntu.edu.tw/handle/123456789/606590We measure the branching fractions and CP asymmetries for the singly Cabibbo-suppressed decays D0 → π+π?η, D0 → K+K?η, and D0 → ?η, using 980 fb?1 of data from the Belle experiment at the KEKB e+e? collider. We obtainB(D0→π+π?η)=[1.22±0.02(stat)±0.02(syst)±0.03(Bref)]×10?3,B(D0→K+K?η)=[1.80?0.06+0.07(stat)±0.04(syst)±0.05(Bref)]×10?4,B(D0→?η)=[1.84±0.09(stat)±0.06(syst)±0.05(Bref)]×10?4, where the third uncertainty (Bref) is from the uncertainty in the branching fraction of the reference mode D0 → K?π+η. The color-suppressed decay D0 → ?η is observed for the first time, with very high significance. The results for the CP asymmetries areACP(D0π+π?η)=[0.9±1.2(stat)±0.5(syst)]%,ACP(D0→K+K?η)=[?1.4±3.3(stat)±1.1(syst)]%,ACP(D0→?η)=[?1.9±4.4(stat)±0.6(syst)]%. The results for D0 → π+π?η are a significant improvement over previous results. The branching fraction and ACP results for D0 → K+K?η, and the ACP result for D0 → ?η, are the first such measurements. No evidence for CP violation is found in any of these decays. [Figure not available: see fulltext.] ? 2021, The Author(s).Branching fraction; Charm physics; CP violation; e+-e? Experiments;[SDGs]SDG16journal article10.1007/JHEP09(2021)0752-s2.0-85115637472