# Role of the Δ Resonance in the Population of a Four-Nucleon State in the $^{56}$Fe → $^{54}$Fe Reaction at Relativistic Energies

Abstract : The 54Fe nucleus was populated from a 56Fe beam impinging on a Be target with an energy of E=A ¼ 500 MeV. The internal decay via γ-ray emission of the 10þ metastable state was observed. As the structure of this isomeric state has to involve at least four unpaired nucleons, it cannot be populated in a simple two-neutron removal reaction from the 56Fe ground state. The isomeric state was produced in the low-momentum (-energy) tail of the parallel momentum (energy) distribution of 54Fe, suggesting that it was populated via the decay of the Δ0 resonance into a proton. This process allows the population of fournucleon states, such as the observed isomer. Therefore, it is concluded that the observation of this 10þ metastable state in 54Fe is a consequence of the quark structure of the nucleons.
Type de document :
Article dans une revue
Physical Review Letters, American Physical Society, 2016, 117 (22), 〈10.1103/PhysRevLett.117.222302〉

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Contributeur : Michel Lion <>
Soumis le : jeudi 24 novembre 2016 - 09:00:18
Dernière modification le : jeudi 11 janvier 2018 - 06:28:19

### Citation

Zs. Podolyák, M. Shand, N. Lalović, J. Gerl, D. Rudolph, et al.. Role of the Δ Resonance in the Population of a Four-Nucleon State in the $^{56}$Fe → $^{54}$Fe Reaction at Relativistic Energies. Physical Review Letters, American Physical Society, 2016, 117 (22), 〈10.1103/PhysRevLett.117.222302〉. 〈in2p3-01401953〉

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