Borromean Feshbach resonance in 11Li studied via 11Li(p,p')

TL;DR

This paper identifies a new dipole Feshbach resonance in 11Li using a three-body model and complex-scaling, revealing unique Borromean system properties and matching experimental scattering data.

Contribution

It introduces a novel Feshbach resonance interpretation in 11Li and demonstrates its effects through microscopic reaction calculations.

Findings

Discovery of a dipole Feshbach resonance in 11Li

Reproduction of experimental scattering and breakup spectra

Insight into Borromean system properties

Abstract

A dipole resonance of 11Li is newly found by a 9Li + n + n three-body model analysis with the complex-scaling method. The resonance can be interpreted as a bound state in the 10Li + n system, that is, a Feshbach resonance in the 9Li + n + n system. As a characteristic feature of the Feshbach resonance of 11Li, the 10Li + n threshold is open above the 9Li + n + n one, which reflects a distinctive property of the Borromean system. A microscopic four-body reaction calculation for the 11Li(p,p') reaction at 6 MeV/nucleon is performed by taking into account the resonance and nonresonant continuum states of the three-body system. The angular distribution of the elastic and inelastic scattering as well as the breakup energy spectrum recently observed are reproduced well.