The effects of the tensor force on the and decay nuclear matrix elements(NMEs)of,,,and are studied using the Hartree-Fock-Bogoliubov(HFB)plus proton-neutron quasi-particle random phase approximation(pnQRPA)model based...The effects of the tensor force on the and decay nuclear matrix elements(NMEs)of,,,and are studied using the Hartree-Fock-Bogoliubov(HFB)plus proton-neutron quasi-particle random phase approximation(pnQRPA)model based on the Skyrme energy density functional.We include the full spectra of intermediate states with up to the energy cutoff E=60 MeV,which is sufficient for convergence of NME calculations.The isovector(IV)pairing and tensor interactions are considered in both HFB and QRPA calculations,while the isoscalar(IS)pairing interaction is included only in QRPA calculations.We found that the tensor force shifts Gamow-Teller(GT)transition strengths substantially to low-energy regions and enhances the decay NME.The inclusion of tensor force enhances the NME by approximately 13%for and and 30%for and,for a fixed IS pairing strength.We found that the intermediate 2-state makes an important contribution to the NME,which is slightly enhanced by the inclusion of the tensor force.We also found that the contribution of the state makes important differences through the inclusion of the tensor force,which enhances the contribution largely.However when the IS pairing strength is increased,the contributions from 1+states are rapidly reduced to be very small,resulting in even negative contributions.Thus,tensor and IS pairing effects cancel each other,making the net effect on the NME relatively small.Due to this cancellation,if the IS pairing strength is optimized separately for cases with and without the tensor interaction to reproduce the experimental NME,the consequent NME with the tensor interaction is close to that without the tensor interaction within a 10%difference.展开更多
In this study,we adopt the self-consistent Hartree-Fock-Bogoliubov(HFB) theory with the proton-neutron quasi-particle random phase approximation(pnQRPA) based on the Skyrme force for calculation of the β^(-) -decay h...In this study,we adopt the self-consistent Hartree-Fock-Bogoliubov(HFB) theory with the proton-neutron quasi-particle random phase approximation(pnQRPA) based on the Skyrme force for calculation of the β^(-) -decay half-lives for nuclei with N~82 and 126 on possible r-process paths.In the calculations,the Skyrme interaction(e.g.,SKO’) is adopted,and the tensor interaction is added self-consistently in both HFB and QRPA calculations.We systematically study how the half-life is changed by varying the strength of the triplet-even(TE) and triplet-odd(TO) components as well as the IS pairing.We find that a variation in strength of the IS pairing of approximately 20% does not produce a substantial effect on β-decay rates with or without the tensor force,while a strength variation of the TO tensor force considerably affects the change in the β-decay half-lives for the very neutron rich N~82 and 126 isotonic chains.In addition,with the inclusion of the tensor force,the GT decay becomes dominant for very neutron-rich nuclei.展开更多
基金Supported by the National Natural Science Foundation of China(11575120,11822504,12075104)National Key Research and Development(R&D)programe of China(2021YFA1601500)+2 种基金Science Specialty Program of Sichuan University(2020SCUNL210)the support from Chinese Academy of Sciences for the project of Young Scientists in Basic Research(YSBR-099)"From 0 to 1 innovative"program.This work was partially supported by JSPS KAKENHI(JP19K03858)。
文摘The effects of the tensor force on the and decay nuclear matrix elements(NMEs)of,,,and are studied using the Hartree-Fock-Bogoliubov(HFB)plus proton-neutron quasi-particle random phase approximation(pnQRPA)model based on the Skyrme energy density functional.We include the full spectra of intermediate states with up to the energy cutoff E=60 MeV,which is sufficient for convergence of NME calculations.The isovector(IV)pairing and tensor interactions are considered in both HFB and QRPA calculations,while the isoscalar(IS)pairing interaction is included only in QRPA calculations.We found that the tensor force shifts Gamow-Teller(GT)transition strengths substantially to low-energy regions and enhances the decay NME.The inclusion of tensor force enhances the NME by approximately 13%for and and 30%for and,for a fixed IS pairing strength.We found that the intermediate 2-state makes an important contribution to the NME,which is slightly enhanced by the inclusion of the tensor force.We also found that the contribution of the state makes important differences through the inclusion of the tensor force,which enhances the contribution largely.However when the IS pairing strength is increased,the contributions from 1+states are rapidly reduced to be very small,resulting in even negative contributions.Thus,tensor and IS pairing effects cancel each other,making the net effect on the NME relatively small.Due to this cancellation,if the IS pairing strength is optimized separately for cases with and without the tensor interaction to reproduce the experimental NME,the consequent NME with the tensor interaction is close to that without the tensor interaction within a 10%difference.
基金Supported by the National Natural Science Foundation of China(11575120,11822504)Science Specialty Program of Sichuan University(2020SCUNL210)。
文摘In this study,we adopt the self-consistent Hartree-Fock-Bogoliubov(HFB) theory with the proton-neutron quasi-particle random phase approximation(pnQRPA) based on the Skyrme force for calculation of the β^(-) -decay half-lives for nuclei with N~82 and 126 on possible r-process paths.In the calculations,the Skyrme interaction(e.g.,SKO’) is adopted,and the tensor interaction is added self-consistently in both HFB and QRPA calculations.We systematically study how the half-life is changed by varying the strength of the triplet-even(TE) and triplet-odd(TO) components as well as the IS pairing.We find that a variation in strength of the IS pairing of approximately 20% does not produce a substantial effect on β-decay rates with or without the tensor force,while a strength variation of the TO tensor force considerably affects the change in the β-decay half-lives for the very neutron rich N~82 and 126 isotonic chains.In addition,with the inclusion of the tensor force,the GT decay becomes dominant for very neutron-rich nuclei.
