Measurement of branching fractions and search for CP violation in D 0 ? ? + ? ? ?, D 0 ? K + K ? ?, and D 0 ? ?? at Belle

Abstract

We measure the branching fractions and CP asymmetries for the singly Cabibbo-suppressed decays D0 ? ?+???, D0 ? K+K??, and D0 ? ??, using 980 fb?1 of data from the Belle experiment at the KEKB e+e? collider. We obtainB(D0??+???)=[1.22�0.02(stat)�0.02(syst)�0.03(Bref)]�10?3,B(D0?K+K??)=[1.80?0.06+0.07(stat)�0.04(syst)�0.05(Bref)]�10?4,B(D0???)=[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??+?. The color-suppressed decay D0 ? ?? is observed for the first time, with very high significance. The results for the CP asymmetries areACP(D0?+???)=[0.9�1.2(stat)�0.5(syst)]%,ACP(D0?K+K??)=[?1.4�3.3(stat)�1.1(syst)]%,ACP(D0???)=[?1.9�4.4(stat)�0.6(syst)]%. The results for D0 ? ?+??? are a significant improvement over previous results. The branching fraction and ACP results for D0 ? K+K??, and the ACP result for D0 ? ??, 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).