We present a study of the rare charm meson decays D0→K+K-e+e-, pi+pi-e+e-, and K+pi-e+e- using a 942 fb−1 data set collected by the Belle detector at the KEKB asymmetric-energy e+e- collider. We use D0 candidates identified by the charge of the pion in D∗→D0pi decays and normalize the branching fractions to D0→K-pi+pi-pi+ decays. The branching fraction for decay D0→K+pi-e+e- is measured to be (39.6 ± 4.5 (stat) ± 2.9 (syst)) × 10−7, with the dielectron mass in the rho/omega mass region 675 <875 MeV/c2. We also search for D0→h-h(')+e+e- (h(')=K,pi) decays with the dielectron mass near the eta and phi resonances, and away from these resonances for the K+K-e+e- and pi+pi-e+e- modes. For these modes, we find no significant signals and set 90% confidence level upper limits on their branching fractions at the O(10−7) level.
Measurement of the D0→K-pi+e+e- branching fraction and search for D0→pi+pi-e+e- and D0→K+K-e+e- decays at Belle
Tenchini, F.;
2025-01-01
Abstract
We present a study of the rare charm meson decays D0→K+K-e+e-, pi+pi-e+e-, and K+pi-e+e- using a 942 fb−1 data set collected by the Belle detector at the KEKB asymmetric-energy e+e- collider. We use D0 candidates identified by the charge of the pion in D∗→D0pi decays and normalize the branching fractions to D0→K-pi+pi-pi+ decays. The branching fraction for decay D0→K+pi-e+e- is measured to be (39.6 ± 4.5 (stat) ± 2.9 (syst)) × 10−7, with the dielectron mass in the rho/omega mass region 675 <875 MeV/c2. We also search for D0→h-h(')+e+e- (h(')=K,pi) decays with the dielectron mass near the eta and phi resonances, and away from these resonances for the K+K-e+e- and pi+pi-e+e- modes. For these modes, we find no significant signals and set 90% confidence level upper limits on their branching fractions at the O(10−7) level.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.


