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Article Dans Une Revue Phys.Lett.B Année : 2017

Unexpected high-energy γ emission from decaying exotic nuclei

C. Delafosse
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  • IdHAL : c-delafosse
C. Sotty
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C. Andreoiu
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C. Costache
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N. Marginean
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R. Marginean
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M. Martini
C. Mihai
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I. Mitu
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L. Stan
  • Fonction : Auteur
D. Testov

Résumé

The N=52 Ga83 β decay was studied at ALTO. The radioactive 83 Ga beam was produced through the ISOL photofission technique and collected on a movable tape for the measurement of γ -ray emission following β decay. While β -delayed neutron emission has been measured to be 56–85% of the decay path, in this experiment an unexpected high-energy 5–9 MeV γ -ray yield of 16(4)% was observed, coming from states several MeVs above the neutron separation threshold. This result is compared with cutting-edge QRPA calculations, which show that when neutrons deeply bound in the core of the nucleus decay into protons via a Gamow–Teller transition, they give rise to a dipolar oscillation of nuclear matter in the nucleus. This leads to large electromagnetic transition probabilities which can compete with neutron emission, thus affecting the β -decay path. This process is enhanced by an excess of neutrons on the nuclear surface and may thus be a common feature for very neutron-rich isotopes, challenging the present understanding of decay properties of exotic nuclei.

Dates et versions

hal-01582765 , version 1 (06-09-2017)

Identifiants

Citer

A. Gottardo, D. Verney, I. Deloncle, S. Péru, C. Delafosse, et al.. Unexpected high-energy γ emission from decaying exotic nuclei. Phys.Lett.B, 2017, 772, pp.359-362. ⟨10.1016/j.physletb.2017.06.050⟩. ⟨hal-01582765⟩
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