用电子散射研究丰质子核的质子晕结构

理论和实验结果都表明¹⁷F的第一激发态有质子晕存在.用相对论平均场理论和Eikonal近似研究了质子晕核¹⁷F的第一激发态的电子弹性散射过程. 计算了¹⁷F的第一激发态的电荷形状因子,并与¹⁶O和¹⁹F的结果进行了对比和讨论.结果显示质子晕的存在会使中等转移动量的电荷形状因子产生明显的变化,并且使低转移动量的电荷形状因子趋于降低.这说明电子散射对质子晕的存在是非常敏感的,表明可以用电子散射对奇特核的质子晕结构进行更精细的研究.     

奇特原子核6,8He的电荷形状因子研究

应用相对论Eikonal近似计算了用不同模型给出的^6,8He的电荷半径和电荷分布的形状因子, 并将结果与⁶He和⁴He的实验结果进行了比较. 结果显示不同模型给出的电荷半径和电荷形状因子差别很大, 表明不同模型给出的晕中子与α核芯的关联有很大的差异. 计算和讨论结果为在下一代电子-原子核对撞机上可能进行的实验提供了理论参考, 同时, 也为现有讨论奇特原子核的理论模型提供了检验.     

相对论平均场理论对Se，Kr，Sr和Zr同位素链形状共存的系统研究

在约束形变的相对论平均场理论下,用NL3参数组系统地研究了Se,Kr,Sr和Zr四个同位素链中的偶-偶核,理论计算的基态束缚能和实验值符合得非常好.通过对这些核的位能曲面的分析,发现在此区域内有着丰富的形状共存现象,系统地指出可能存在形状共存现象的原子核,并且进一步指出在这些核的位能曲面上两个能量极小点的能量差.另外通过对位能曲面以及单中子能级的研究,提出在此区域内N＝70可能是一个中子幻数. 关键词： 形状共存 相对论平均场 位能曲面 幻数     

P同位素的质子滴线核研究

研究了在相对论平均场近似下P同位素的滴线核的性质,首先在理论上探讨了25P作为P的滴线核存在的可能性及其可能具有的质子晕结构,然后给出了在兰州放射性束流装置上25P的实验鉴别结果. Great progress was made on the study of P isotope both in theory and in experiments, but the final conclusion about the dripline of P isotope has not been made. In this article the properties of P isotope was studied in the frame work of relativistic mean field (RMF). First the probability of 25P as the dripline nuclei of P isotope and the proton halo structure of 25P was discussed, and then the RIBLL experiental result of 25P is presented.     

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.     

（100）~Sn核墓态性质的微观研究

用相对论平均场理论和非相对论平均场理论计算了双幻核１００Ｓｎ的结合能，核物质分布半径，中子分布半径和质子分布半径等，并对这两种理论计算结果进行了比较和讨论．这是对１００Ｓｎ核的第一个微观计算．     

相对论平均场理论对Pt同位素形状演化的研究

利用形变约束的相对论平均场理论研究了Pt同位素偶-偶核的形状演化,比较了基态结合能和四极形变的理论计算值和实验值, 分析了这些核的位能曲线、单粒子能级及其随四极形变β₂ 的变化规律,发现从N=88到N=126, Pt同位素的基态变形从球形对称核经X(5)对称性核、演化为具有稳定形变的核,再演化为球形核的变化过程.其中, ^166-172Pt是近球形核, ¹⁷⁴Pt和^192-196Pt位于球形和稳定形变之间,可能具有X(5)对称性, ^176-190Pt具有稳定的变形, ^198-202Pt是近球形核, ²⁰⁴Pt是球形核,这些结果与实验一致.     

相对论平均场理论对重核中结团现象的研究

用相对论平均场理论结合结团模型对重核结团现象进行了研究. 首先将原子核分为两个部分, 然后用相对论平均场模型对原子核的核子按束缚能的高低来分布, 结果获得了与实验相一致的结团. 这表明相对论平均场模型也适用于重核结团现象的研究.     

相对论平均场理论对Pb同位素位移的研究

运用变形的相对论平均场理论研究了Pb同位素链的基态性质. 对关联的处理采用了BCS方法, 不成对核子的处理运用了“阻塞”法. 计算的结果很好地符合了实验上Pb的平均结合能, 中子分离能, 同位素位移. 接着从原子核的微观结构出发, 比较详细地研究了Pb链同位素位移出现反常扭折这一重要性质的物理机制.     

相对论和非相对论理论模型研究奇异核的性质

采用相对论和非相对论理论模型可描述奇异核的性质 .相对论平均场理论预言了2 6,2 7,2 8P存在一个质子晕 ,而27,28,29S存在两个质子晕 .最近 ,MSU的最新的实验发现了2 6,2 7,2 8P核存在一个质子晕.采用相对论 Hartree- Fock理论研究了 Fock项和矢量介子对奇异核性质的贡献,研究表明交换项和矢量介子对非常丰中子核性质的影响非常不同于对稳定线附近核性质的影响.同时,采用形变的Hartree- Fock- Bogoliubov理论研究了某些轻核同位素链的性质和形变.     

The Effect of Hyperon-Hyperon Interaction on Neutron Stars

The equations ofstate of the neutron star matter are calculated in the relativistic mean-field approximation witl different hyperon coupling constants. The properties of neutron stars are studied by solving the OppenheimerVolkoff equation. It manifests the properties of neutron stars - change explicitly as different hyperon coupling constants are concerned.``     

The Effect of Hyperon-Hyperon Interaction on Neutron Stars

The equations of state of the neutron star matter are calculated in the relativistic mean-field approximation with different hyperon coupling constants. The properties of neutron stars are studied by solving the Oppenheimer-Volkoff equation. It manifests the properties of neutron stars — change explicitly as different hyperon coupling constants are concerned.     

A～50区同位素的相对论平均场研究

利用轴向形变相对论平均场理论计算了A～50区的核基态性质,结果表明,在Fe同位素链中最稳定的核是⁵⁶Fe和⁵⁸Fe而不是通常的⁵⁴Fe;给出了⁴⁶Cr,⁵⁰Fe和⁵⁴N(N=Z－2),⁴⁵Cr,⁴⁹Fe和⁵³Ni(N=Z－3)核的质子和中子分离能,分析了它们的稳定性.     

Neutron Stars in the Model of Non-linear Realization of SU(2) Chiral Symmetry Spontaneous Breaking

The properties of neutron stars are studied in a relativistic mean-field model with SU(2) chiral symmetry spontaneous breaking being considered. The calculation results indicate that the effects of the chiral symmetry spontaneous breaking are not negligible.     

相对论粒子的散射与低速粒子的散射

研究了相对论粒子间散射的规律,推导了相对论粒子间散射的洛伦兹因子公式.结果发现:如果两个粒子的静止质量相同,则粒子在高速时的碰撞规律和低速时的碰撞规律相同,即两个正碰粒子互换速度;如果两个粒子的静止质量不同,则粒子在高速时的碰撞规律和低速时的碰撞规律不同,高速正碰时重粒子将损失大部分能量,轻粒子的速度将接近光速,而不等于重粒子速度的2倍.     

Charge Densities of Unstable Nuclei with Electron Scattering

Relativistic mean-field theory and phase-shift analysis are combined together to investigate the elastic Coulomb scattering between electrons and unstable nuclei. Electron scattering at several different energies is studied and compared, in order to see the energy dependence of electron-nucleus scattering. It is shown that electron scattering at 200 MeV or 300 MeV can be used to reveal electron-nucleus scattering information around the first diffraction minimum. Shifts in opposite directions are obtained for the first diffraction minima of the electron scattering off the ground and first excited states of ^17F with ^16O as reference, and similar effects are obtained for ^18Ne. Besides, some neutron-rich N = 8 isotones are also studied. Results show that electron scattering will be very useful and important in studying both proton- and neutron-rich nuclei in the future.     

Charge Densities of Unstable Nuclei with Electron Scattering

Relativistic mean-field theory and phase-shift analysis are combined together to investigate the elastic Coulomb scattering between electrons and unstable nuclei. Electron scattering at several different energies is studied and compared, in order to see the energy dependence of electron-nucleus scattering. It is shown that electron scattering at 200 MeV or 300 MeV can be used to reveal electron-nucleus scattering information around the first diffraction minimum. Shifts in opposite directions are obtained for the first diffraction minima of the electron scattering off the ground and first excited states of ¹⁷F with ¹⁶O as reference, and similar effects are obtained for ¹⁸Ne. Besides, some neutron-rich N=8 isotones are also studied. Results showthat electron scattering will be very useful and important in studying both proton- and neutron-rich nuclei in the future.     

Coulomb effects on the formation of proton halo nuclei

This paper makes some qualitative and quantitative analyses about halo formation rules of some mirror nuclei with the relativistic mean-field (RMF) theory and the Woods--Saxon mean-field model. By analysing two opposite effects of Coulomb interaction on the proton halo formation, it finds that the energy level shift has a larger contribution than that of the Coulomb barrier when the mass number A is small, the hindrance of the Coulomb barrier becomes more obvious with the increase of the mass number A, and the overall effect of the Coulomb interaction almost disappears when A≈39 as its two effects counteract with each other.