材料期刊网

We study a mixture of s-bosons and like-nucleon pairs with the standard pairing interaction outside an inert core.Competition between the nucleon-pairs and s-bosons is investigated in this scenario.The robustness of the BCS-BEC coexistence and crossover phenomena are examined through an analysis of p f-shell nuclei with realistic single-particle energies,in which two configurations with Pauli blocking of nucleon-pair orbits due to the formation of the s-bosons is taken into account.When the nucleon-pair orbits are considered to be independent of the s-bosons,the BCS-BEC crossover becomes smooth,with the number of the s-bosons noticeably more than that of the nucleon-pairs near the half-shell point,a feature that is demonstrated in the p f-shell for several values of the standard pairing interaction strength.As a further test of the robustness of the BCS-BEC coexistence and crossover phenomena in nuclei,results are given for B(E2;01+ →21+) values of even-even 102-130Sn with 100Sn taken as a core and valence neutron pairs confined within the 1d5/2,0g7/2,1d3/2,2s1/2,1h11/2 orbits in the nucleon-pair orbit and the s-boson independent approximation.The results indicate that the B(E2) values are reproduced well.