title: Spins and magnetic moments of 49K and 51K: establishing the 1/2+ and 3/2+ level ordering beyond N = 28.
abstract: The ground-state spins and magnetic moments of (49,51)K have been measured using bunched-beam high-resolution collinear laser spectroscopy at ISOLDE CERN. For 49K a ground-state spin I = 1/2 was firmly established. The observed hyperfine structure of 51K requires a spin I > 1/2 and strongly suggests I = 3/2. From its magnetic moment μ(51K) = +0.5129(22)μ(N) a spin-parity I(π) = 3/2+ with a dominant π1d(3/2)(-1) hole configuration was deduced. This establishes for the first time the reinversion of the single-particle levels and illustrates the prominent role of the residual monopole interaction for single-particle levels and shell evolution.
authors.affiliation: Instituut voor Kern-en Stralingsfysica, KU Leuven, B-3001 Leuven, Belgium. jasna.papuga@fys.kuleuven.be
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authors.lastname: Papuga
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