Related papers: Dineutron formation and breaking in $^8$He
The ground and excited states of $^{8}$He were investigated with a method of antisymmetrized molecular dynamics(AMD). We adopted effective nuclear interactions which systematically reproduce the binding energies of $^4$He, $^6$He and…
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…
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…
We propose a new framework by means of the dineutron condensate (DC) wave function to describe the dineutron correlation, which is characterized by the spatially strong correlation of a spin-zero neutron-neutron pair, in neutron-rich nuclei…
The $0_2^+$ state of ${}^8\mathrm{He}$ has been discovered by a recent experiment, which suggested a developed cluster structure of spatially correlated neutron pairs, called "dineutrons" (${}^2n$). We aim to investigate the structure of…
The hyper-radial barrier strongly hinders formation of more than three clusters. We investigate how well the dominating cluster components in $^7$He and $^8$He, respectively can be described as $\alpha$+$n$+$^2n$ and $\alpha$+$^2n$+$^2n$,…
Two-neutron densities obtained from microscopic wave functions of $^6$He and $^8$He are investigated to reveal di-neutron correlations. In particular, the comparison of the two-neutron density with the product of one-neutron densities is…
We study the dinucleon (dineutron and diproton) correlation of the ground states of $^9$Li, $^{10}$Be, and $^{9,10}$C. We assume an $\alpha+t$ core for $^9$Li, an $\alpha+\alpha$ core for $^{10}$Be and $^{10}$C, and an $\alpha+^3$He core…
Recent experiments clearly demonstrate the importance of the excited state $2^+$ at 1.8 MeV in the substruture ${^6}He$ for the ground state of the nucleus ${^8}He$. It is shown here that this means that the ground state structure of…
We extend the method of antisymmetrized molecular dynamics to investigate dineutron correlation. We apply this method to $^{10}$Be as an example and investigate the motion of two neutrons around a largely deformed $^8$Be core by analyzing…
The quest to understand multi-neutron systems has a long history, and recent experimental efforts aim to probe candidate four-neutron configurations in neutron-rich light nuclei such as ${}^8$He and ${}^7$H via quasi-free knockout…
We investigate the multineutron excitations of neutron-rich $^8$He in the electric dipole strength using a $^4$He+$n$+$n$+$n$+$n$ five-body model. Many-body unbound states of $^8$He are obtained in the complex scaling method. We found that…
We evaluate pairwise correlations using ground state wave functions for $^4$He and $^6$He obtained by $\textit{ab initio}$ no-core shell model (NCSM) calculations with the Daejeon16 nucleon-nucleon interaction plus Coulomb interaction, to…
We investigated the development and breaking of the dineutron correlation in $^{10}$Be by analyzing the elastic and inelastic scatterings with a framework combing the microscopic structure and reaction models. For studying the structure,…
To discuss the dineutron correlation in the ground state, the quasi-free neutron knockout reaction on $^6$He is investigated.In the present work, the momentum distribution of the two emitted neutrons is calculated with the…
Within the complex-energy configuration interaction framework, we study correlations of valence neutrons to explain the behavior of charge radii in the neutron halo nuclei $^{6,8}$He. We find that the experimentally observed decrease of the…
We propose a simple schematic model for two-neutron halo nuclei. In this model, the two valence neutrons move in a one-dimensional mean field, interacting with each other via a density-dependent contact interaction. We first investigate the…
Decay mode of the $2_1^+$ resonant state of $^6$He populated by the $^6$He breakup reaction by $^{12}$C at 240 MeV/nucleon is investigated. The continuum-discretized coupled-channels method is adopted to describe the formation of the…
The neutron pairing correlation and the soft dipole excitation in medium-mass nuclei near drip-line are investigated from a viewpoint of the di-neutron correlation. Numerical analyses by means of the coordinate-space HFB and the continuum…
The weak binding and spatially extended neutron densities characteristic of drip-line nuclei give rise to a distinctive low-energy dipole response. The drip-line nucleus $^8$He is the most neutron-rich bound nucleus with a mass-to-charge…