D_s介子几个重要衰变分支比的绝对测量  

Absolute Measurement of Important Branching Fractions of the D_s Meson

作　　者：张长春[1] 李卫国[1] 毛慧顺[1] 顾建辉[1] 李小南[1] 荣刚[1] 

机构地区：[1]中国科学院高能物理研究所,北京100039

出　　处：《高能物理与核物理》2000年第6期593-608,共16页High Energy Physics and Nuclear Physics

基　　金：国家自然科学基金!(19991480);中国科学院重大及特别支持项目!(KJ95T-03)资助

摘　　要：在正负电子对撞能量 4 0 3GeV处 ,BES实验在BEPC对撞机上完成了Ds 介子纯轻子衰变 ,半轻子衰变和φπ+ 分支比的绝对测量 .文章详细描述了用于π与K识别的联合置信度方法 ,Ds单标记和双标记技术 ,以及计算Ds 衰变分支比的最大似然函数 .对所得物理结果做了讨论和评述 .Absolute measurement of branching fractions of purely leptonic decay, semi leptonic decay and φπ + decay of the D s meson at a c. m. energy of 4.03 GeV were completed from the BES experiment at the BEPC electron positron collider. The method by using combined confidence level for pion and kaon separation, the D s single and double tagging technology, and the maximum likelihood functions in the estimate of the D s branching fractions are described in details. Discussion and comments on these physics results are made. Prospect for improved measurement of D s physics in future is also given.

关 键 词：Ds衰变分支比 绝对测量 Ds介子 

分 类 号：O572.3[理学—粒子物理与原子核物理]