TY  - JOUR
AU  - Yokoyama, R. et al
AU  - Tain, J. L.
AU  - Algora, A.
AU  - Agramunt, J.
AU  - Domingo-Pardo, C.
AU  - Morales, A. I.
AU  - Rubio, B.
AU  - Tolosa-Delgado, A.
PY  - 2023
DA  - 2023//
TI  - β-delayed neutron emissions from N > 50 gallium isotopes
T2  - Phys. Rev. C
JO  - Physical Review C
SP  - 064307
EP  - 15pp
VL  - 108
IS  - 6
PB  - Amer Physical Soc
AB  - beta-delayed gamma-neutron spectroscopy has been performed on the decay of A=84 to 87 gallium isotopes at the RI-beam Factory at the RIKEN Nishina Center using a high-efficiency array of 3He neutron counters (BRIKEN). beta-2n-gamma events were measured in the decays of all of the four isotopes for the first time, which is direct evidence for populating the excited states of two-neutron daughter nuclei. Detailed decay schemes with the gamma branching ratios were obtained for these isotopes, and the neutron emission probabilities (P-xn) were updated from the previous study. Hauser-Feshbach statistical model calculations were performed to understand the experimental branching ratios. We found that the P-1n and P-2n values are sensitive to the nuclear level densities of 1n daughter nuclei and showed that the statistical model reproduced the P-2n/P-1n ratio better when experimental levels plus shell-model level densities fit by the Gilbert-Cameron formula were used as the level-density input. We also showed the neutron and gamma branching ratios are sensitive to the ground-state spin of the parent nucleus. Our statistical model analysis suggested J <= 3 for the unknown ground-state spin of the odd-odd nucleus Ga-86, from the I gamma(4(+)-> 2(+))/I-gamma(2(+)-> 0(+)) ratio of Ga-84 and the P-2n/P-1n ratio. These results show the necessity of detailed understanding of the decay scheme, including data from neutron spectroscopy, in addition to gamma measurements of the multineutron emitters.
SN  - 2469-9985
UR  - https://doi.org/10.1103/PhysRevC.108.064307
DO  - 10.1103/PhysRevC.108.064307
LA  - English
N1  - WOS:001159167500001
ID  - Yokoyama_etal2023
ER  -