6He structure from semiclassical 3D models based on ab initio spatial correlations
Abstract
We construct semiclassical 3D models based on ab initio no-core shell model calculated two-body spatial correlations, which represent the preferred spatial configuration of nucleons for the ground state of 6He. We demonstrate that the presence of the two valence neutrons distorts and flattens the α core in 6He, marking a clear departure from the tetrahedral configuration of free 4He, and that the two valence neutrons and the center of mass of the α cluster (α-CM) are roughly located at the three distinct vertices of an equilateral triangle. We compute the geometric parameters that commonly characterize 6He structure, 1) θnn, the opening angle of the two valence neutrons with respect to α-CM, and 2) rnn, the root-mean-square separation between the two valence neutrons. Refining the model with uncertainty estimation, we obtain θnn= 58.5+5.4−6.2 degrees and rnn= 4.12+0.37−0.43 fm, agreeing with those calculated via a phenomenologically modified continuum-discretized coupled-channels method, while an interferometry experiment obtained a marginally higher rnn.
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BibTeX
@misc{huang2026structure,
title = {{$^6$He structure from semiclassical 3D models based on $\textitab initio$ spatial correlations}},
author = {Mengyao Huang and Tobias Frederico and Peng Yin and James P. Vary},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.22365},
eprint = {2610.22365},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.22365},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - ^6He structure from semiclassical 3D models based on ab initio spatial correlations
AU - Mengyao Huang
AU - Tobias Frederico
AU - Peng Yin
AU - James P. Vary
PY - 2026
DA - 2026/10/17
PB - arXiv
DO - 10.48550/arxiv.2610.22365
UR - https://arxiv.org/abs/2610.22365
AB - We construct semiclassical 3D models based on ab initio no-core shell model calculated two-body spatial correlations, which represent the preferred spatial configuration of nucleons for the ground state of ^6He. We demonstrate that the presence of the two valence neutrons distorts and flattens the α core in ^6He, marking a clear departure from the tetrahedral configuration of free ^4He, and that the two valence neutrons and the center of mass of the α cluster (α-CM) are roughly located at the three distinct vertices of an equilateral triangle. We compute the geometric parameters that commonly characterize ^6He structure, 1) θ_nn, the opening angle of the two valence neutrons with respect to α-CM, and 2) r_nn, the root-mean-square separation between the two valence neutrons. Refining the model with uncertainty estimation, we obtain θ_nn= 58.5^+5.4_−6.2 degrees and r_nn= 4.12^+0.37_−0.43 fm, agreeing with those calculated via a phenomenologically modified continuum-discretized coupled-channels method, while an interferometry experiment obtained a marginally higher r_nn.
ER -