重子-介子散射共振态及奇特重子态的夸克模型研究

Recently, a lot of new hadrons， which are difficult to be explained by the conventional quark models, have been reported by many experimental collaborations. The conventional quark models can give a good description to the ground state hadrons. However, it is difficult to describe some excited states of hadrons. In recent years, we have studied hadron-hadron scattering systematically, in which the multi-channel coupling resonance method is used. By using this method, a ΔΔ resonance is obtained, which can be used to explain the ABC effect in the pd reactions reported by the CELSIUS-WASA group. In this project, we will calculate baryon-meson scattering phase shifts in the constituent quark models and improve the models by comparing the results with experimental data. By use of the improved 3P0 model, the multi-channel coupling scattering calculation will be done to look for resonances. In addition, the bayon spectrum will be re-calculated by taking into account of the multi-quark components to explain the various excitation of baryons. By this project, we hope to give good explanation to the many experimental data of baryons and to predict new baryon states to guide the experimental research of the exotic baryons.

近年来国内外相关大型科学实验装置发现了许多新强子态，难以用传统的夸克模型来解释。传统的组分夸克模型对基态强子可以给出很好的描述，但对于激发态强子的描述却存在问题。我们组近年来对强子-强子散射进行了系列研究，并将核物理中发展起来的耦合道共振方法应用于夸克模型。利用此方法我们得到的ΔΔ共振态可很好地解释最近CELSIUS-WASA合作组在pd反应中观测到的ABC效应。本项目就是在组分夸克模型框架下，通过计算重子-介子散射并与实验数据比较，改进夸克模型；通过改进普遍使用的3P0模型，进行多道耦合散射计算，寻找共振态；同时在重子谱计算中考虑多夸克效应，尝试解释重子的各种激发态。通过此研究一方面对现有实验数据，特别是重子激发谱给出合理解释；另一方面预言新的重子态，为实验上寻找新的重子共振态给出指导。

近年来国内外相关大型科学实验装置发现了许多新强子态，难以用传统的夸克模型来解释。我们项目组在手征夸克模型和夸克蜕定域色屏蔽模型框架下，通过研究重子-介子散射过程，并将核物理中发展的耦合道共振方法应用于夸克模型，对奇特重子态以及多夸克态进行研究，并通过改进普遍使用的3P0模型考虑多夸克效应计算重子谱及重子激发谱，我们发现可以在N\pi散射中得到Δ（1232）的共振态以及与实验一致的衰变宽度，考虑三夸克与五夸克耦合后可以解释一些传统夸克模型无法描述的奇特重子态。另外由于WASA-at-COSY实验组和STAR实验组以及格点QCD计算寻找双重子态方面的进展，我们项目组结合群论方面的特长增加了对双重子态的研究，为实验上寻找双重子态给出指导。