Dineutron-dineutron correlation in ${}^8$He

Abstract

Background: The four-neutron correlation has been attracting much attention for decades. In addition to the study on the tetra-neutron system, it is worthwhile to investigate the correlation in bound systems. Purpose: The ${}^8$He nucleus is a system where four neutrons are weakly bound around the ${}^4$He core. The dineutron ($2n$) correlation has been long discussed in various weakly-bound neutron-rich nuclei such as ${}^6$He and ${}^{11}$Li, whereas the ${}^8$He nucleus gives us an opportunity to investigate the $2n$-$2n$ type four-neutron correlation. Methods: We introduce a microscopic ${}^4\mathrm{He}+4n$ model and describe the ground-state structure of ${}^8$He. The mixing of the two-$2n$ component in the ground state is examined. The ground-state wave function is verified by investigating various observables including high-energy scattering cross sections. Results: Our model reasonably reproduces the available experimental data, the binding energy, charge radius, total reaction cross section, and proton-nucleus elastic scattering cross section data. We find that the significant mixing of the two-$2n$ cluster configurations around ${}^4$He in the ground state of ${}^8$He: The ground state has a squared overlap of about 45% with a $2n$-${}^4$He-$2n$ configuration with the ${}^4$He-$2n$ distance of 3 fm and opening angle of 80${}^{\circ }$. Conclusion: The ground state of ${}^8$He contains a certain amount of the two-$2n$ cluster component, indicating the strong nuclear deformation, which was experimentally observed recently.

arXiv comment8 pages, 6 figures

References in corpus (32)

• Alpha cluster condensation in 12C and 16O
• Realistic models of pion-exchange three-nucleon interactions
• Nuclear charge radius of ${}^8$He
• Ab initio no-core full configuration calculations of light nuclei
• Reaction cross sections of carbon isotopes incident on a proton
• The detection of neutron clusters
• Di-neutron correlation and soft dipole excitation in medium mass neutron-rich nuclei near drip-line
• Systematic analysis of reaction cross sections of carbon isotopes
• ${}^{22}$C: $S$-Wave Two-Neutron Halo
• Probing the weakly-bound neutron orbit of ${}^{31}$Ne with total reaction and one-neutron removal cross sections
• Prediction for a four-neutron resonance
• On the possibility of generating a 4-neutron resonance with a {\boldmath $T=3/2$} isospin 3-neutron force
• Glauber-model analysis of total reaction cross sections for Ne, Mg, Si, and S isotopes with Skyrme-Hartree-Fock densities
• Proton radii of 4,6,8He isotopes from high-precision nucleon-nucleon interactions
• Strong dineutron correlation in 8He and 18C
• Dineutron structure in ${}^8$He
• Simplified modeling of cluster-shell competition in ${}^{20}$Ne and ${}^{24}$Mg
• Elastic and total reaction cross sections of oxygen isotopes in Glauber theory
• Examination of the ${}^{22}$C radius determination with interaction cross sections
• Tetraneutron: Rigorous continuum calculation
• Energy Spectrum of Neutron-Rich Helium Isotopes: Complex Made Simple
• Five-body resonances of 8C using the complex scaling method
• Ab-initio coupled-cluster calculations of ground and dipole excited states in 8He
• Dineutron formation and breaking in ${}^8$He
• Electric dipole response of ${}^6$He: Halo-neutron and core excitations
• Complete Glauber calculations for proton-nucleus inelastic cross sections
• Resonant states in ${}^7$H. I. Experimental studies of the ${}^2$H(${}^8$He,${}^3$He) reaction
• Density profiles near nuclear surface of ${}^{44,52}$Ti: An indication of $\alpha$ clustering
• Imprints of $\alpha$ clustering in the density profiles of ${}^{12}$C and ${}^{16}$O
• Soft dipole resonance in neutron-rich ${}^8$He
• ${}^7$H ground state as a ${}^3$H+4n resonance
• Experimental investigation of ground-state properties of ${}^7$H with transfer reactions

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• A Vision for the Science of Rare Isotopes
• Low-energy dipole strength in 8He
• Polaronic neutron in dilute alpha matter: A $p$-wave Bose polaron
• Dineutron clusters in ${}^7$He and ${}^8$He structure