title: First Penning-trap mass measurement of the exotic halo nucleus 11Li.
abstract: In this Letter, we report a new mass for 11Li using the trapping experiment TITAN at TRIUMF's ISAC facility. This is by far the shortest-lived nuclide, t_{1/2}=8.8 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 7 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 11Li. This result is a remarkable confluence of nuclear and atomic physics.
authors.affiliation: TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Smith
authors.forename: M
authors.initials: M
authors.lastname: Brodeur
authors.forename: T
authors.initials: T
authors.lastname: Brunner
authors.forename: S
authors.initials: S
authors.lastname: Ettenauer
authors.forename: A
authors.initials: A
authors.lastname: Lapierre
authors.forename: R
authors.initials: R
authors.lastname: Ringle
authors.forename: V L
authors.initials: VL
authors.lastname: Ryjkov
authors.forename: F
authors.initials: F
authors.lastname: Ames
authors.forename: P
authors.initials: P
authors.lastname: Bricault
authors.forename: G W F
authors.initials: GW
authors.lastname: Drake
authors.forename: P
authors.initials: P
authors.lastname: Delheij
authors.forename: D
authors.initials: D
authors.lastname: Lunney
authors.forename: F
authors.initials: F
authors.lastname: Sarazin
authors.forename: J
authors.initials: J
authors.lastname: Dilling