%0 Journal Article
%T Role of the Delta Resonance in the Population of a Four-Nucleon State in the Fe-56 -> Fe-54 Reaction at Relativistic Energies
%A Podolyak, Z.
%J Physical Review Letters
%D 2016
%V 117
%N 22
%I Amer Physical Soc
%@ 0031-9007
%G English
%F Podolyak2016
%O WOS:000388630000009
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=2875), last updated on Thu, 22 Dec 2016 15:48:35 +0000
%X The Fe-54 nucleus was populated from a Fe-56 beam impinging on a Be target with an energy of E/A = 500 MeV. The internal decay via gamma-ray emission of the 10(+) 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 Fe-56 ground state. The isomeric state was produced in the low-momentum (-energy) tail of the parallel momentum (energy) distribution of Fe-54, suggesting that it was populated via the decay of the Delta(0) 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 10(+) metastable state in Fe-54 is a consequence of the quark structure of the nucleons.
%R 10.1103/PhysRevLett.117.222302
%U https://doi.org/10.1103/PhysRevLett.117.222302
%P 222302-6pp