Ab-initio no-core Gamow shell model calculations of multi-neutron systems

TL;DR

This study uses an advanced ab-initio no-core Gamow shell model to calculate energies and widths of multi-neutron systems, concluding both are unbound but with the tetraneutron's properties aligning with recent experiments.

Contribution

First ab-initio calculations of multi-neutron resonances using the no-core Gamow shell model with realistic interactions.

Findings

Tetraneutron is unbound with broad width.

Calculated tetraneutron energy matches recent experimental data.

Trineutron is more likely to be observed experimentally than tetraneutron.

Abstract

The existence of multi-neutron systems has always been a debatable question. Indeed, both inter-nucleon correlations and a large continuum coupling occur in these states. We then employ the ab-initio no-core Gamow shell model to calculate the resonant energies and widths of the trineutron and tetraneutron systems with realistic interactions. Our results indicate that trineutron and tetraneutron are both unbound and bear broad widths. The calculated energy and width of tetraneutron are also comparable with recent experimental data. Moreover, our calculations suggest that the energy of trineutron is lower than that of tetraneutron, while its resonance width is also narrower. This strongly suggests that trineutron is more likely to be experimentally observed than tetraneutron. We thus suggest experimentalists to search for trineutron at low energy.