First Penning-trap mass measurement in the millisecond half-life range: the exotic halo nucleus 11Li

TL;DR

This study reports the first Penning-trap mass measurement of the extremely short-lived nucleus 11Li, achieving high precision and enabling improved understanding of its halo structure through combined nuclear and atomic physics analyses.

Contribution

First mass measurement of 11Li with a Penning trap for a nucleus with an 8.8 ms half-life, providing more precise nuclear data for halo nucleus studies.

Findings

New mass of 11Li with unprecedented short half-life measurement

Refined two-neutron separation energy of 369.15(65) keV

New charge radius derived from combined nuclear and atomic physics

Abstract

In this letter, we report a new mass for $^{11}$Li using the trapping experiment TITAN at TRIUMF's ISAC facility. This is by far the shortest-lived nuclide, $t_{1/2} = 8.8 \rm{ms}$, for which a mass measurement has ever been performed with a Penning trap. Combined with our mass measurements of $^{8,9}$Li we derive a new two-neutron separation energy of 369.15(65) keV: a factor of seven more precise than the best previous value. This new value is a critical ingredient for the determination of the halo charge radius from isotope-shift measurements. We also report results from state-of-the-art atomic-physics calculations using the new mass and extract a new charge radius for $^{11}$Li. This result is a remarkable confluence of nuclear and atomic physics.