TY  - JOUR
AU  - Ciemala, M. et al
AU  - Domingo-Pardo, C.
AU  - Perez-Vidal, R. M.
PY  - 2020
DA  - 2020//
TI  - Testing ab initio nuclear structure in neutron-rich nuclei: Lifetime measurements of second 2(+) state in C-16 and O-20
T2  - Phys. Rev. C
JO  - Physical Review C
SP  - 021303
EP  - 7pp
VL  - 101
IS  - 2
PB  - Amer Physical Soc
AB  - To test the predictive power of ab initio nuclear structure theory, the lifetime of the second 2(+) state in neutron-rich O-20, tau(2(2)(+)) = 150(-30)(+80) fs, and an estimate for the lifetime of the second 2(+) state in C-16 have been obtained for the first time. The results were achieved via a novel Monte Carlo technique that allowed us to measure nuclear state lifetimes in the tens-to-hundreds of femtoseconds range by analyzing the Doppler-shifted gamma-transition line shapes of products of low-energy transfer and deep-inelastic processes in the reaction O-18 (7.0 MeV/u) + Ta-181. The requested sensitivity could only be reached owing to the excellent performances of the Advanced gamma-Tracking Array AGATA, coupled to the PARIS scintillator array and to the VAMOS++ magnetic spectrometer. The experimental lifetimes agree with predictions of ab initio calculations using two- and three-nucleon interactions, obtained with the valence-space in-medium similarity renormalization group for O-20 and with the no-core shell model for C-16. The present measurement shows the power of electromagnetic observables, determined with high-precision gamma spectroscopy, to assess the quality of first-principles nuclear structure calculations, complementing common benchmarks based on nuclear energies. The proposed experimental approach will be essential for short lifetime measurements in unexplored regions of the nuclear chart, including r-process nuclei, when intense beams, produced by Isotope Separation On-Line (ISOL) techniques, become available.
SN  - 2469-9985
UR  - https://arxiv.org/abs/2002.04814
UR  - https://doi.org/10.1103/PhysRevC.101.021303
DO  - 10.1103/PhysRevC.101.021303
LA  - English
N1  - WOS:000517222700001
ID  - Ciemala_etal2020
ER  -