D0→K-μ+νμ和D0→π-μ+νμ半轻衰变分支比的绝对测量

摘要

利用BEPC上的BES Ⅱ探测器所收集的33 pb-1数据样本,测量了D0的半轻衰变D0→K-μ+νμ和D0→π-μ+νμ的分支比. 在7584±198±341个单标记0的反冲测,观察到89.0±13.8个D0→K-μ+νμ事例和9.3±7.5个D0→π-μ+νμ 事例,从而测得BF(D0→K-μ+νμ)=(3.62±0.56±0.59)%和BF(D0→π-μ+νμ)=(0.38±0.31±0.10)%.%Based of a data sample of 33pb-1 collected around 3.773 GeV with the BESⅡdetector at the BEPC,the measorement of absolute branching fraction for exclusive D0 semimuonic decay into K-μ-νμand π-μ+Vμis reported. In the system recoiling against 7584±198±341 singly tagged-D0 mesons,89.0±13.8 events for D0→K-μ+νμand 9.3±7.5 events for D0→π-μ+Vμare observed. Those yield the absolute branching fractions to be BF(D0→K-μ+νμ)=(3.62±0.56±0.59)%and BF(D0→π-μ+Vμ)=(0.38±0.31±0.10)%.