η_c→e^+e^-μ^+μ^-衰变研究

Muti-Lepton Decays of η_c Meson

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.