The electric quadrupole moment Q and the magnetic momentp(or the g factor)of low-lying states in even-even nuclei 72-80Ge and odd-mass nuclei 75-79 Ge are studied in the framework of the nucleon pair approximation(NPA...The electric quadrupole moment Q and the magnetic momentp(or the g factor)of low-lying states in even-even nuclei 72-80Ge and odd-mass nuclei 75-79 Ge are studied in the framework of the nucleon pair approximation(NPA)of the shell model,assuming the monopole and quadrupole pairing plus quadrupole-quadrupole interaction.HA H.Our calculations reproduce well the experimental values of Q(21^+)and g(21^+)for 72,74,76 Ge,as well as the yrast energy levels of these isotopes.The structure of the 21^+states and the contributions of the proton and neutron components in Q(21^+)and g(21^+)are discussed in the SD-pair truncated shell-model subspace.The overall trend of Q(21^+)and g(21^+)as a function of the mass number A,as well as their signs,are found to originate essentially from the proton contribution.The negative value of Q(21^+)in 72,74Ge is suggested to be due to the enhanced quadrupole-quadrupole correlation and configuration mixing.展开更多
Systematic calculations of low-lying energy levels,B(E2)transitions,and g factors of even-even tellurium isotopes with mass numbers from 128 to 140 are performed via the nucleon-pair approximation(NPA)of the shell mod...Systematic calculations of low-lying energy levels,B(E2)transitions,and g factors of even-even tellurium isotopes with mass numbers from 128 to 140 are performed via the nucleon-pair approximation(NPA)of the shell model with phenomenological multipole-multipole interactions.An optimal agreement is obtained between the calculated results and experimental data.The yrast band structures of nuclei below and above the N=82 shell closure are compared and discussed.In particular,the evolutionary differences of B(E2;2^(+)_(1)→0^(+)_(1))values and g(2^(+)_(1))factors,with respect to the symmetry of N=82,are attributed to the dominant contribution differences in neutron and proton excitations,respectively.展开更多
基金Supported by National Natural Science Foundation of China(11875188)Open Project Fund of Shanghai Key Laboratory of Particle Physics and Cosmology(18DZ2271500-2)+1 种基金Sichuan Science and Technology Program(2019JDRC0017)the Doctoral Program of Southwest University of Science and Technology(18zx7147)
文摘The electric quadrupole moment Q and the magnetic momentp(or the g factor)of low-lying states in even-even nuclei 72-80Ge and odd-mass nuclei 75-79 Ge are studied in the framework of the nucleon pair approximation(NPA)of the shell model,assuming the monopole and quadrupole pairing plus quadrupole-quadrupole interaction.HA H.Our calculations reproduce well the experimental values of Q(21^+)and g(21^+)for 72,74,76 Ge,as well as the yrast energy levels of these isotopes.The structure of the 21^+states and the contributions of the proton and neutron components in Q(21^+)and g(21^+)are discussed in the SD-pair truncated shell-model subspace.The overall trend of Q(21^+)and g(21^+)as a function of the mass number A,as well as their signs,are found to originate essentially from the proton contribution.The negative value of Q(21^+)in 72,74Ge is suggested to be due to the enhanced quadrupole-quadrupole correlation and configuration mixing.
基金Supported by National Natural Science Foundation of China (11875188, 11905130 and 12075169)Sichuan Science and Technology Program (2019JDRC0017)+1 种基金the Doctoral Program of Southwest University of Science and Technology (18zx7147)Shanghai Sailing Program (19YF1434200)。
文摘Systematic calculations of low-lying energy levels,B(E2)transitions,and g factors of even-even tellurium isotopes with mass numbers from 128 to 140 are performed via the nucleon-pair approximation(NPA)of the shell model with phenomenological multipole-multipole interactions.An optimal agreement is obtained between the calculated results and experimental data.The yrast band structures of nuclei below and above the N=82 shell closure are compared and discussed.In particular,the evolutionary differences of B(E2;2^(+)_(1)→0^(+)_(1))values and g(2^(+)_(1))factors,with respect to the symmetry of N=82,are attributed to the dominant contribution differences in neutron and proton excitations,respectively.
