Abstract
The first γ-ray spectroscopy of Ar52, with the neutron number N=34, was measured using the K53(p,2p) one-proton removal reaction at ∼210 MeV/u at the RIBF facility. The 21+ excitation energy is found at 1656(18) keV, the highest among the Ar isotopes with N>20. This result is the first experimental signature of the persistence of the N=34 subshell closure beyond Ca54, i.e., below the magic proton number Z=20. Shell-model calculations with phenomenological and chiral-effective-field-theory interactions both reproduce the measured 21+ systematics of neutron-rich Ar isotopes, and support a N=34 subshell closure in Ar52.
Original language | English |
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Article number | 072502 |
Journal | Physical Review Letters |
Volume | 122 |
Issue number | 7 |
DOIs | |
State | Published - 21 Feb 2019 |
Externally published | Yes |