一种处理原子核多体问题的有效方法

由二级散射矩阵元出发计算了核物质内强子的二级自能修正, 并且归纳了一种研究原子核多体问题的有效方法. 另外, 还讨论了各种密度相关的相对论多体方法之间的关系.     

Dynamically generated resonances

In this talk I report on recent work related to the dynamical generation of baryonic resonances, some made up from pseudoscalar meson-baryon, others from vector meson-baryon and a third type from two meson-one baryon systems. We can establish a correspondence with known baryonic resonances, reinforcing conclusions previously drawn and bringing new light on the nature of some baryonic resonances of higher mass.     

Particle-number-conserving analysis of multiquasiparticle bands in 177Lu

The experimental one-, three-, and five-quasiparticle bands in 177Lu are analyzed by the particle-number conserving （PNC） method for treating the cranked shell model with pairing interaction, in which the blocking effects are taken into account exactly. The experimental moments of inertia are reproduced very well by PNC calculations with us free parameter.     

原子核内光子的有效质量

研究了无限大核子费密气体和有限原子核内电磁场的性质.由于电荷密度算符的基态期待值在核子费密气体内不为零,电荷的U(1)定域规范对称性自发破缺.微扰计算光子的自能可知在核子费密气体内光子有效质量与质子的标量密度有关.在饱和密度ρ0=0.16fm^－3的正常核物质中,光子有效质量为5.42MeV;在²³⁸U原子核的表面处,光子有效质量约为2.0MeV.在这一问题中,这两种方法是等价的.同时文章指出正是由于原子核表面处有质量光子的两体衰变导致在低能²³⁸U+²³²Th重离子碰撞实验中正反电子对尖锐谱线的发现.     

矢量介子和重子八重态相互作用及其动力学生成的共振态的分波分析（英文）

研究了t道、s道、u道和由张量相互作用项导致的接触项对矢量介子和重子八重态之间的相互作用势的贡献。在分波分析的框架下,求解了耦合道的李普曼–施温格方程,研究了动力学生成的奇异数S=0,同位旋为I=1/2的重子共振态N(1650)1/2-和N(1700)3/2-,N(1895)1/2-和N(1875)3/2-,N(2120)3/2-,以及同位旋I=3/2的重子共振态△(1620)1/2-和△(1700)3/2-的质量、衰变宽度、和角动量等性质。另外,计算结果表明,在2 000 Me V附近存在着JP=1/2-的N(2120)3/2-的对偶共振态。     

Pseudoscalar meson and baryon octet interaction with strangeness zero in the unitary coupled-channel approximation

The interaction of the pseudoscalar meson and the baryon octet is investigated by solving the Bethe-Salpeter equation in the unitary coupled-channel approximation. In addition to the Weinberg-Tomozawa term, the contribution of the s-and u-channel potentials in the-wave approximation are taken into account. In the sector of isospin I=1/2 and strangeness S =0, a pole is detected in a reasonable region of the complex energy plane of ■ in the center-of-mass frame by analyzing the behavior of the scattering amplitude, which is higher than the ηN threshold and lies on the third Riemann sheet. Thus, it can be regarded as a resonance state and might correspond to the N(1535) particle of the Particle Data Group(PDG) review. The coupling constants of this resonance state to the πN,ηN,KΛ and KΣ channels are calculated, and it is found that this resonance state couples strongly to the hidden strange channels. Apparently, the hidden strange channels play an important role in the generation of resonance states with strangeness zero. The interaction of the pseudoscalar meson and the baryon octet is repulsive in the sector of isospin I = 3/2 and strangeness S = 0, so that no resonance state can be generated dynamically.     

The D~* interaction with isospin zero in an extended hidden gauge symmetry approach

The D~* interaction via a ρ or ω exchange is constructed within an extended hidden gauge symmetry approach, where the strange quark is replaced by the charm quark in the SU(3) flavor space. With this D~*interaction, a bound state slightly lower than the D~* threshold is generated dynamically in the isospin zero sector by solving the Bethe-Salpeter equation in the coupled-channel approximation, which might correspond to the X(3872)particle announced by many collaborations. This formulism is also used to study the BB~* interaction, and a BB~* bound state with isospin zero is generated dynamically, which has no counterpart listed in the review of the Particle Data Group. Furthermore, the one-pion exchange between the D meson and the ~* is analyzed precisely, and we do not think the one-pion exchange potential need be considered when the Bethe-Salpeter equation is solved.     

Dynamically generated resonances from the vector octet-baryon decuplet interaction and their radiative decays into $\gamma$-baryon decuplet

The dynarnically generated resonances from vector meson-baryon decuplet are studied using La- grangians of the hidden gauge theory for vector interactions. One shows that some of the generated states can be associated with some known baryon resonances in the PDG data, while others are predictions for new states. Furthermore, we calculate the radiative decay widths of these resonances into a photon and a baryon decuplet.     

中子星的相对论平均场研究

在相对论平均框架内计算了不同超子耦合参数下中子星内部物质的状态方程,进一步求解Oppenheimer-Volkoff方程得到了中子星的各种性质.结果表明,参数的变化对这些性质有明显的影响.     

Particle-number conserving analysis of the high-K multi-quasiparticle bands in 179Re

The experimentally observed ten rotational bands in 179Re are analyzed with the particle-number conserving method for treating the cranked shell model with pairing interaction, in which the blocking effects are taken into account exactly. The experimental moments of inertia of these bands are reproduced quite well by our calculations with no free parameter and the deformation driving effects are discussed. The bandhead energies and the variation in the occupation probability of each cranked orbital are also analyzed.