Measurement of branching fractions for D meson decaying into ? meson and a pseudoscalar meson

摘要

The four decay modesD0→?π0,D0→?η,D+→?π+, andD+→?K+are studied by using a data sample taken at the centre-of-mass energys=3.773GeV with the BESIII detector, corresponding to an integrated luminosity of 2.93 fb?1. The branching fractions of the first three decay modes are measured to beB(D0→?π0)=(1.168±0.028±0.028)×10?3,B(D0→?η)=(1.81±0.46±0.06)×10?4, andB(D+→?π+)=(5.70±0.05±0.13)×10?3, respectively, where the first uncertainties are statistical and the second are systematic. In addition, the upper limit of the branching fraction forD+→?K+is given to be2.1×10?5at the 90% confidence level. The ratio ofB(D0→?π0)toB(D+→?π+)is calculated to be(20.49±0.50±0.45)%, which is consistent with the theoretical prediction based on isospin symmetry between these two decay modes.