## SciPost Submission Page

# Low-energy neutron scattering on light nuclei and $^{19}$B as a $^{17}$B-$n$-$n$ three-body system in the unitary limit

### by Jaume Carbonell, Emiko Hiyama, Rimantas Lazauska and F. Miguel Marqués

#### - Published as SciPost Phys. Proc. 3, 008 (2020)

### Submission summary

As Contributors: | Jaume Carbonell |

Preprint link: | scipost_201911_00038v2 |

Date accepted: | 2020-01-28 |

Date submitted: | 2020-01-15 |

Submitted by: | Carbonell, Jaume |

Submitted to: | SciPost Physics Proceedings |

Proceedings issue: | 24th European Few Body Conference (University of Surrey, U.K.) |

Discipline: | Physics |

Subject area: | Nuclear Physics - Theory |

Approaches: | Theoretical, Experimental, Computational, Phenomenological |

### Abstract

We consider the evolution of the neutron-nucleus scattering length for the lightest nuclei. We show that, when increasing the number of neutrons in the target nucleus, the strong Pauli repulsion is weakened and the balance with the attractive nucleon-nucleon interaction results into a resonant virtual state in $^{18}$B. We describe $^{19}$B in terms of a $^{17}$B-$n$-$n$ three-body system where the two-body subsystems $^{17}$B-$n$ and $n$-$n$ are unbound (virtual) states close to the unitary limit. The energy of $^{19}$B ground state is well reproduced and two low-lying resonances are predicted. Their eventual link with the Efimov physics is discussed. This model can be extended to describe the recently discovered resonant states in $^{20,21}$B.

Published as SciPost Phys. Proc. 3, 008 (2020)