Observation of the Singly Cabibbo-Suppressed Decay D + › ? ? + and Evidence for D 0 › ? ? 0

Abstract

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 + › ??+ and D 0 › ??0 . A double tag technique is used to measure the absolute branching fractions B(D + › ??+) = (2.79± 0.57± 0.16) × 10-4 and B(D 0 › ??0) = (1.17±0.34±0.07)×10-4, with statistical significances of 5.5? and 4.1?, respectively. We also present measurements of the absolute branching fractions for the related ?? decay modes. We find B(D + › ??+) = (3.07 ± 0.22 ± 0.13) × 10-3 and B(D 0 › ??0) = (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.