巨单极共振和对称能

基于带有混合同位旋标量-矢量非线性耦合的有效拉格朗日量, 在完全自洽的相对论无规位相近似的框架内, 通过单极压缩模式讨论了核物质的不可压缩性. 比较核²⁰⁸Pb,¹⁴⁴Sm,¹¹⁶Sn和⁹⁰Zr实验和计算的巨单极共振能量, 给出了核物质不可压缩系数的取值范围. 新的同位旋标量-矢量非线性耦合软化核物质的对称能, 但无损于基态性质与实验的一致性. 讨论了对称能的软化对巨单极共振的影响.

Giant Monopole Resonance and Symmetry Energy

Nuclear matter incompressibility is discussed by the monopole compression modes in nuclei in the framework of a fully consistent relativistic random phase approximation, based on effective Lagrangians with a mixed isoscalar-isovector nonlinear coupling term. A predicted value of the matter incompressibility coefficient is given by comparison between experimental and calculated energies of the isoscalar giant monopole resonance (ISGMR) in nuclei 208Pb, 144Sm, 116Sn and 90Zr. The new isoscalar-isovector nonlinear coupling softens the nuclear matter symmetry energy without ruining the agreement with experimentally existing ground state properties. The effect of the softening of the symmetry energy on the ISGMR is discussed.