A close look at the competition of isovector and isoscalar pairing in A=18 and 20 even-even N≈Z nuclei  

作　　者：Feng Pan Dan Zhou Siyu Yang Yingwen He 潘峰;周丹;杨思雨;Grigor Sargsyan;赫英雯;Kristina D. Launey;Jerry P.Draayer(Department of Physics,Liaoning Normal University,Dalian 116029,China;Department of Physics and Astronomy,Louisiana State University,Baton Rouge,LA 70803-4001,USA)

机构地区：[1]Department of Physics,Liaoning Normal University,Dalian 116029,China [2]Department of Physics and Astronomy,Louisiana State University,Baton Rouge,LA 70803-4001,USA

出　　处：《Chinese Physics C》2019年第7期70-78,共9页中国物理C（英文版）

基　　金：Supported by the National Natural Science Foundation of China(11675071 and 11375080);the U.S.National Science Foundation(OIA-1738287 and ACI-1713690);U.S.Department of Energy(DE-SC0005248);the Southeastern Universities Research Association,the China-U.S.Theory Institute for Physics with Exotic Nuclei(CUSTIPEN)(DE-SC0009971);the LSU-LNNU joint research program(9961)

摘　　要：The competition of isovector and isoscalar pairing in A=18 and 20 even-even N≈Z nuclei is analyzed in the framework of the mean-field plus the dynamic quadurpole-quadurpole, pairing and particle-hole interactions, whose Hamiltonian is diagonalized in the basis U(24) ?(U(6) ? S U(3) ? S O(3))■(U(4) ? S US(2)■ S UT(2)) in the L = 0 configuration subspace. Besides the pairing interaction, it is observed that the quadurpole-quadurpole and particlehole interactions also play a significant role in determining the relative positions of low-lying excited 0^+ and 1^+ levels and their energy gaps, which can result in the ground state first-order quantum phase transition from J = 0 to J = 1.The strengths of the isovector and isoscalar pairing interactions in these even-even nuclei are estimated with respect to the energy gap and the total contribution to the binding energy. Most importantly, it is shown that although the mechanism of the particle-hole contribution to the binding energy is different, it is indirectly related to the Wigner term in the binding energy.competition of isovector and isoscalar pairing in A=18 and 20 even-even N≈Z nuclei is analyzed in the framework of the mean-field plus the dynamic quadurpole-quadurpole, pairing and particle-hole interactions, whose Hamiltonian is diagonalized in the basis U(24)■(U(6)■ S U(3)■ S O(3))■(U(4)■S US(2)■ S UT(2)) in the L = 0 configuration subspace. Besides the pairing interaction, it is observed that the quadurpole-quadurpole and particlehole interactions also play a significant role in determining the relative positions of low-lying excited 0^+ and 1^+ levels and their energy gaps, which can result in the ground state first-order quantum phase transition from J = 0 to J = 1.The strengths of the isovector and isoscalar pairing interactions in these even-even nuclei are estimated with respect to the energy gap and the total contribution to the binding energy. Most importantly, it is shown that although the mechanism of the particle-hole contribution to the binding energy is different, it is indirectly related to the Wigner term in the binding energy.

关 键 词：isovector and ISOSCALAR PAIRING INTERACTION particle-hole INTERACTION light mass N≈Z NUCLEI 

分 类 号：O571[理学—粒子物理与原子核物理]