Intruder configurations in the A=33 isobars: 33Mg and 33Al.
The beta decay of 33Mg (N=21) presented in this Letter reveals intruder configurations in both the parent and the daughter nucleus. The lowest excited states in the N=20 daughter nucleus, 33Al, are found to have nearly 2p-2h intruder configuration, thus extending the "island of inversion" beyond Mg. The allowed direct beta-decay branch to the 5/2{+} ground state of the daughter nucleus 33Al implies positive parity for the ground state of the parent 33Mg, contrary to an earlier suggestion of negative parity from a g-factor measurement. An admixture of 1p-1h and 3p-3h configurations is proposed for the ground state of 33Mg to explain all of the experimental observables.
Department of Physics, Florida State University, Tallahassee, Florida 32306, USA.
Vandana
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Tripathi
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Tabor
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Mantica
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Utsuno
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Bender
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Cook
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Hoffman
Sangjin
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Lee
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Otsuka
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Pereira
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Perry
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Pepper
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Pinter
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Stoker
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