PT Journal
AU AGATA Collaboration (Avigo, Rea
   Domingo-Pardo, C
   Gadea, A
   Gonzalez, V
TI Low-lying electric dipole gamma-continuum for the unstable Fe-62(,)64 nuclei: Strength evolution with neutron number
SO Physics Letters B
JI Phys. Lett. B
PY 2020
BP 135951
EP 6pp
VL 811
DI 10.1016/j.physletb.2020.135951
LA English
DE Fe-64; Fe-62; Nuclear structure; Dipole excitation around neutron threshold
AB The gamma-ray emission from the nuclei Fe-62,Fe-64 following Coulomb excitation at bombarding energy of 400-440 AMeV was measured with special focus on E1 transitions in the energy region 4-8 MeV. The unstable neutron-rich nuclei Fe-62,Fe-64 were produced at the FAIR-GSI laboratories and selected with the FRS spectrometer. The gamma decay was detected with AGATA. From the measured gamma-ray spectra the summed E1 strength is extracted and compared to microscopic quasi-particle phonon model calculations. The trend of the E1 strength with increasing neutron number is found to be fairly well reproduced with calculations that assume a rather complex structure of the 1(-) states (three-phonon states) inducing a strong fragmentation of the E1 nuclear response below the neutron binding energy.
ER