In this study,we investigate the robustness of pair structures for nuclear yrast states,that is,whether the structures of relevant collective pairs as building blocks of different yrast states are the same.We focus on...In this study,we investigate the robustness of pair structures for nuclear yrast states,that is,whether the structures of relevant collective pairs as building blocks of different yrast states are the same.We focus on deformed and transitional nuclei and study the yrast states of^(28)Si,^(50)Cr,and^(132)Xe,whose experimental R_(4/2)values are 2.60,2.40,and 2.16,respectively,using the nucleon-pair approximation(NPA)and shell-model effective interactions.For each yrast state,we consider optimized pair structures to be those providing the energy minimum for this state.To find the minimum,many full NPA calculations are performed with varying pair structures,and the numerical optimization procedure of the conjugate gradient method is implemented.Our results suggest that optimized pair structures remain the same for all states within a rotational band of a deformed nucleus.Our results also suggest that after backbending,that is,changing of the intrinsic state,the structure of the S pair,which is essential to build the monopole pairing correlation,remains approximately unchanged,whereas the structures of the non-S pairs,which are essential to build the quadrupole correlation,change significantly.展开更多
The deformations of multi-Λ hypernuclei corresponding to even-even core nuclei ranging from^(8)Be to^(40)Ca with 2,4,6,and 8 hyperons are studied using the deformed Skyrme-Hartree-Fock approach.It is found that the d...The deformations of multi-Λ hypernuclei corresponding to even-even core nuclei ranging from^(8)Be to^(40)Ca with 2,4,6,and 8 hyperons are studied using the deformed Skyrme-Hartree-Fock approach.It is found that the deformations are reduced when adding 2 or 8 Λ hyperons,but enhanced when adding 4 or 6 Λ hyperons.These differences are attributed to the fact that Λ hyperons are filled gradually into the three deformed p orbits,of which the [110] 1/2^(-)orbit is prolately deformed and the degenerate [101]1/2^(-)and [101]3/2^(-)orbits are oblately deformed.展开更多
基金Supported by the National Natural Science Foundation of China(11875134,11875188,12175071,11975151,11961141003)the Shanghai Key Laboratory of Particle Physics and Cosmology(21DZ2271500-2)。
文摘In this study,we investigate the robustness of pair structures for nuclear yrast states,that is,whether the structures of relevant collective pairs as building blocks of different yrast states are the same.We focus on deformed and transitional nuclei and study the yrast states of^(28)Si,^(50)Cr,and^(132)Xe,whose experimental R_(4/2)values are 2.60,2.40,and 2.16,respectively,using the nucleon-pair approximation(NPA)and shell-model effective interactions.For each yrast state,we consider optimized pair structures to be those providing the energy minimum for this state.To find the minimum,many full NPA calculations are performed with varying pair structures,and the numerical optimization procedure of the conjugate gradient method is implemented.Our results suggest that optimized pair structures remain the same for all states within a rotational band of a deformed nucleus.Our results also suggest that after backbending,that is,changing of the intrinsic state,the structure of the S pair,which is essential to build the monopole pairing correlation,remains approximately unchanged,whereas the structures of the non-S pairs,which are essential to build the quadrupole correlation,change significantly.
基金Supported by the National Natural Science Foundation of China (12175071, 11775081, 11905165)。
文摘The deformations of multi-Λ hypernuclei corresponding to even-even core nuclei ranging from^(8)Be to^(40)Ca with 2,4,6,and 8 hyperons are studied using the deformed Skyrme-Hartree-Fock approach.It is found that the deformations are reduced when adding 2 or 8 Λ hyperons,but enhanced when adding 4 or 6 Λ hyperons.These differences are attributed to the fact that Λ hyperons are filled gradually into the three deformed p orbits,of which the [110] 1/2^(-)orbit is prolately deformed and the degenerate [101]1/2^(-)and [101]3/2^(-)orbits are oblately deformed.
