Charge radius and dipole response of $^{11}$Li

TL;DR

This paper analyzes the relationship between charge radius and dipole response of $^{11}$Li using a three-body model, revealing how these observables relate to the core-neutron distance and constraining the s-wave component in its halo structure.

Contribution

It provides a consistent interpretation of charge radius and dipole response measurements within a three-body model, constraining the s-wave component of $^{11}$Li's ground state.

Findings

Discrepancy between measurements is about 1.5σ.

Charge radius favors ~50% s-wave component.

Dipole response favors ~25% s-wave component.

Abstract

We investigate the consistency of the measured charge radius and dipole response of $^{11}$Li within a three-body model. We show how these observables are related to the mean square distance between the $^9$Li core and the center of mass of the two valence neutrons. In this representation we find by considering the effect of smaller corrections that the discrepancy between the results of the two measurements is of the order of 1.5$\sigma$. We also investigate the sensitivity to the three-body structure of $^{11}$Li and find that the charge radius measurement favors a model with a 50% s-wave component in the ground state of the two-neutron halo, whereas the dipole response is consistent with a smaller s-wave component of about 25% value.