η_c→e^+e^-μ^+μ^-衰变研究  

Muti-Lepton Decays of η_c Meson

作　　者：朱海文[1] 张振宇[1] 揭泉林[1] 

机构地区：[1]武汉大学物理科学与技术学院,湖北武汉430072

出　　处：《武汉大学学报（理学版）》2015年第5期419-422,共4页Journal of Wuhan University:Natural Science Edition

基　　金：中国科学院青年科学基金资助项目(11105101)

摘　　要：粲夸克偶素的能谱对于理解量子色动力学理论提供了一个很重要的检验根据.本文根据赝标介子到双虚光子过程的Lorentz结构在强子层面计算了ηc→e+e-μ+μ-过程散射振幅,讨论了基于单极点及双极点矢量介子为主模型以及量子色动力学模型的形式因子对衰变宽度及其随不变质量分布的影响,得到单极点及双极点形式因子对ηc→e+e-μ+μ-过程的衰变宽度,预言分别为3.248×10-7MeV和2.426×10-6MeV,双极点形式因子预言的不变质量分布在ρ介子质量区域有明显的峰状分布.The charmonium spectrum is very important to test the theory of quantum chromodynamics. As the lowest lying charmonium state,ηcspectral shape and resonance parameters have become a hot topic currently. In this paper,the decay amplitude was calculated according to the Lorentz structure of the pseudoscalar meson decaying to double virtual photon process,and the impact of single-pole and double-pole vector meson dominate model and the quantum chromodynamics model on the decay width and the invariant mass distributions of this process is discussed,the decay width is predicted as 3. 248 ×10^-7 MeV and 2. 426 × 10^-6MeV for the single-pole and double-pole model respectively. The clear peaks of the invariant mass of the lepton pairs are shown around the mass of ρ meson with the double-pole model.

关 键 词：粲夸克偶素 赝标量介子 矢量介子为主模型 达利兹衰变 

分 类 号：O572.25[理学—粒子物理与原子核物理]