Prediction for a four-neutron resonance

TL;DR

This paper uses advanced ab initio methods to predict a low-lying resonance in the four-neutron system, indicating a possible resonant state near 0.8 MeV with a width of 1.4 MeV.

Contribution

It introduces a novel application of the J-matrix extension of the No-Core Shell Model to predict four-neutron resonances.

Findings

Predicted a four-neutron resonance at 0.8 MeV

Estimated resonance width to be approximately 1.4 MeV

Used ab initio approaches with realistic NN interaction

Abstract

We utilize various {\em ab initio} approaches to search for a low-lying resonance in the four-neutron ($4n$) system using the JISP16 realistic $NN$ interaction. Our most accurate prediction is obtained using a $J$-matrix extension of the No-Core Shell Model and suggests a $4n$ resonant state at an energy near $E_r = 0.8$ MeV with a width of approximately $\Gamma = 1.4$ MeV.