中性D介子半轻子衰变分支比的理论计算  

Numerical Calculations on Branching Fractions of Neutral D Meson Semileptonic Decays

作　　者：周航 张振华[1] 李小华[1] 荆茂强 郑波[1] Zhou Hang;Zhang Zhenhua;Li Xiaohua;Jing Maoqiang;Zheng Bo(School of Nuclear Science and Technology, University of South China, Hengyang 421001, China)

机构地区：[1]南华大学核科学技术学院,湖南衡阳421001

出　　处：《南开大学学报（自然科学版）》2018年第3期31-36,43,共7页Acta Scientiarum Naturalium Universitatis Nankaiensis

基　　金：国家自然科学基金(11575077;11475090)

摘　　要：根据4种将非微扰的强相互作用参数化为形状因子的模型得到的4种强子形状因子,分别计算了中性D介子D^0→K^-e^+ν_e和D^0→π^-e^+ν_e两个半轻子衰变过程的衰变分支比.将计算结果与实验测量值比较,得到极点修正模型对D_0→K^-e^+ν_e过程的理论计算结果中心值与实验测量值非常接近,而对D^0→π^-e^+ν_e过程两参量多级展开模型符合较好.然而由于非微扰效应的存在,形状因子f+(0)和强耦合常数g等参数误差过大,因此得到的理论计算结果误差较大.Four models are introduced, which parameterized the non-perturbative interaction as form factor with different ways. Using the form factors, we calculated the branching fractions of D^0 → K^-e~＋νe and D^0 → π^-e~＋νe. Comparing these to the experimental values, we obtain that the value calculated with Modified Pole Model can well describe D^0 → K^-e~＋νe, while Series Expansion Model can well describe D^0 → π^-e~＋νe. However, due to the non-perturbative effect, the errors of form factors and strong coupling parameters are relative large, which lead to large errors of the calculated results.

关 键 词：中性D介子 半轻子衰变 强子形状因子 分支比计算 

分 类 号：O572[理学—粒子物理与原子核物理]