PT Journal
AU Podolyak, Z
TI Role of the Delta Resonance in the Population of a Four-Nucleon State in the Fe-56 -> Fe-54 Reaction at Relativistic Energies
SO Physical Review Letters
JI Phys. Rev. Lett.
PY 2016
BP 222302
EP 6pp
VL 117
IS 22
DI 10.1103/PhysRevLett.117.222302
LA English
AB 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.
ER