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从多体关联Green函数的基本动力学方程组出发,通过对多体关联Green函数作低阶截断近似,得到了通常Green函数理论中所有主要的非微扰结果.而且二体关联Green函数动力学把梯形图对应的短程关联与环形图对应的长程关联统一在同一个动力学方程组中,这是通常的Green函数理论所没有得到的新结果. 相似文献
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在Extended Brueckner Hartree Fock(EBHF)近似下, 采用Argonne V18势作为核子 核子相互作用, 计算了基态非对称核物质中核子动量的分布。 对核子的动量分布对同位旋不对称度的依赖关系进行了描述和讨论。 结果表明, 在不对称度为零时, 质子与中子有着基本相同的动量分布。 随着不对称度的增加, 在各自的费米面以下, 质子动量分布减小而中子动量分布增大。 对费米面处的准粒子强度也进行了计算和讨论。 本结果较好地满足了两个理论检验标准Migdal Luttinger theorem 和粒子数守恒律。 We calculate the momentum distribution of nucleons in asymmetric nuclear matter within the framework of the extended Brueckner Hartree Fock approximation at zero temperature, use Argonne V18 potential as two nucleons potential. The isospin asymmetry dependence of the nucleon momentum distribution predicted and discussed. It is shown that as the asymmetry increases, the proton momentum distribution become smaller while the neutron one gets higher below their respective Fermi surfaces with respect to their common values in symmetric nuclear matter. The quasi particle strength at the Fermi momentum also calculated and discussed, we got an improved fulfillment of the Migdal Luttinger theorem and nucleon number conservation. 相似文献
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在核密度模型基础之上利用原子核密度经验公式得到的核密度和利用电磁半径平方平均值得到的核密度分别计算了轻子 核深度非弹性散射过程中的核效应函数RHe/D(x, Q2), RLi/D(x, Q2), RC/Li(x, Q2), RCa/Li(x, Q2), 发现利用由原子核密度经验公式得到的核密度计算核效应函数所得结果与NMC实验数据符合得较好, 并且优于用后者方法计算核效应函数的理论结果, 从而说明利用原子核密度经验公式研究核子结构函数核效应的合理性。 The nuclear effect functions in l A DIS process RHe/D(x, Q2), RLi/D(x, Q2), RC/Li(x, Q2) and RCa/Li(x, Q2) are calculated on the basis of the nuclear density model by using nuclear densities obtained from an empirical formula or the experimental values of the electromagnetic mean of radius square 〈r2〉, respectively.It is shown that the nuclear effect functions obtained from the empirical formula are in good agreement with the NMC experimental data, and better than the later ones.The empirical formula of the nuclear density can be used to study the nuclear effect of nucleon structure functions reasonably. 相似文献
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在扩展的同位旋相关的Brueckner-Hartree-Fock理论框架内,计算了同位旋非对称核物质中质子与中子的单粒子势和有效质量及其同位旋效应,并详细研究和讨论了基态关联对单粒子势和有效质量及其同位旋依赖的影响. 相似文献
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We investigate the ^3PF2 neutron superfluidity in H-stable neutron star matter and neutron stars by using the BCS theory and the Brueckner-Hartree-Fock approach. We adopt the Argonne V18 potential supplemented with a microscopic three-body force as the realistic nucleon-nucleon interaction. We have concentrated on studying the threebody force effect on the ^3PF2 neutron pairing gap. It is found that the three-body force effect is to enhance remarkably the ^3PF2 neutron superfluidity in neutron star matter and neutron stars. 相似文献
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利用Brueckner-Hartree-Fock和BCS理论方法,计算了非对称核物质中处于1S0态的质子和中子的对关联能隙,着重研究和讨论了能隙的同位旋依赖性和三体核力的影响.结果表明:随核物质的同位旋非对称度增大,中子1S0态超流相存在的密度范围逐渐缩小而且对关联能隙峰值稍有升高;质子1S0态超流相存在的密度范围迅速扩大而且对关联能隙峰值显著降低.三体核力对非对称核物质中1S0态中子超流性及其同位旋依赖性的影响相对较小,但对1S0态质子超流性具有重要影响,而且其效应随核子数密度增大而迅速增强.三体核力的主要作用是强烈地抑制了具有高非对称度的核物质中高密度区域的1S0态质子超流性,导致质子超流相存在的密度范围显著缩小. 相似文献