title: Orbital dependent nucleonic pairing in the lightest known isotopes of tin.
abstract: By studying the (109)Xe→(105)Te→(101)Sn superallowed α-decay chain, we observe low-lying states in (101)Sn, the one-neutron system outside doubly magic (100)Sn. We find that the spins of the ground state (J=7/2) and first excited state (J=5/2) in (101)Sn are reversed with respect to the traditional level ordering postulated for (103)Sn and the heavier tin isotopes. Through simple arguments and state-of-the-art shell-model calculations we explain this unexpected switch in terms of a transition from the single-particle regime to the collective mode in which orbital-dependent pairing correlations dominate.
authors.affiliation: Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA.
authors.forename: I G
authors.initials: IG
authors.lastname: Darby
authors.forename: R K
authors.initials: RK
authors.lastname: Grzywacz
authors.forename: J C
authors.initials: JC
authors.lastname: Batchelder
authors.forename: C R
authors.initials: CR
authors.lastname: Bingham
authors.forename: L
authors.initials: L
authors.lastname: Cartegni
authors.forename: C J
authors.initials: CJ
authors.lastname: Gross
authors.forename: M
authors.initials: M
authors.lastname: Hjorth-Jensen
authors.forename: D T
authors.initials: DT
authors.lastname: Joss
authors.forename: S N
authors.initials: SN
authors.lastname: Liddick
authors.forename: W
authors.initials: W
authors.lastname: Nazarewicz
authors.forename: S
authors.initials: S
authors.lastname: Padgett
authors.forename: R D
authors.initials: RD
authors.lastname: Page
authors.forename: T
authors.initials: T
authors.lastname: Papenbrock
authors.forename: M M
authors.initials: MM
authors.lastname: Rajabali
authors.forename: J
authors.initials: J
authors.lastname: Rotureau
authors.forename: K P
authors.initials: KP
authors.lastname: Rykaczewski