Various collective states in the i 124 nucleus


Moon C, Moon B, Park J, Dracoulis GD, Kibédi T, Bark RA, Byrne AP, Davidson PA, Lane GJ & Wilson AN (2021) Various collective states in the i 124 nucleus. Physical Review C, 103 (3), Art. No.: 034318.

The level structure of 124I (Z=53, N=71) has been studied via the 122Sn (7Li, 5n)124I reaction with a beam energy of 54 MeV. Through in-beam and out-of-beam γ-ray spectroscopy, the sophisticated low-lying levels including isomeric states and numerous collective states have been established for the first time. A positive-parity collective band built on the 10+ state at 1297 keV is interpreted as being associated with the combination of a proton and a neutron in the same intruder h11/2 orbital, namely the πh11/2νh11/2 configuration. This band shows a typical quadrupole vibrational character. In contrast, the negative parity bands based on the πg7/2νh11/2 configuration show a soft triaxial rotation. An isomeric 8− state at 689 keV with a half-life of 14 ns can be explained as a K isomer due to a proton with an Ωp=9/2 in the g9/2 orbital coupled to a neutron with an Ωn=7/2 in the h11/2 orbital. The excited states based on this πg9/2νh11/2 configuration show a coupled rotational structure. Another coupled rotational band built on the 6+ state at 714 keV is thought to be based on the πg9/2νd3/2 configuration.

Publication date31/03/2021
Publication date online22/03/2021
Date accepted by journal09/03/2021