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arXiv · 0803.3258

Strong dineutron correlation in 8He and 18C

K. Hagino·N. Takahashi·H. Sagawa
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Abstract

We study the spatial structure of four valence neutrons in the ground state of $^8$He and $^{18}$C nuclei using a core+4$n$ model. For this purpose, we employ a density-dependent contact interaction among the valence neutrons, and solve the five-body Hamiltonian in the Hartree-Fock-Bogoliubov (HFB) approximation. We show that two neutrons with the coupled spin of $S$=0 exhibit a strong dineutron correlation around the surface of these nuclei, whereas the correlation between the two dineutrons is much weaker. Our calculation indicates that the probability of the (1p$_{3/2})^4$ and [(1p$_{3/2})^2$ (p$_{1/2})^2$] configurations in the ground state wave function of $^8$He nucleus is 34.9% and 23.7%, respectively. This is consistent with the recent experimental finding with the $^8$He($p,t)^6$He reaction, that is, the ground state wave function of $^8$He deviates significantly from the pure (1p$_{3/2})^4$ structure.

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K. Hagino, N. Takahashi, H. Sagawa. 2008-03-22. Strong dineutron correlation in 8He and 18C. https://doi.org/10.1103/physrevc.77.054317

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