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Testing $ab initio$ nuclear structure in neutron-rich nuclei: lifetime measurements of second 2$^+$ states in $^{16}$C and $^{20}$O
- Source :
- Phys.Rev.C, Phys.Rev.C, 2020, 101 (2), pp.021303. ⟨10.1103/PhysRevC.101.021303⟩, Physical Review C, Physical Review C, American Physical Society, 2020, 101 (2), pp.021303. ⟨10.1103/PhysRevC.101.021303⟩, Physical review / C 101(2), 021303 (2020). doi:10.1103/PhysRevC.101.021303, 'Physical Review C ', vol: 101, pages: 021303-1-021303-7 (2020)
- Publication Year :
- 2020
- Publisher :
- HAL CCSD, 2020.
-
Abstract
- To test the predictive power of ab initio nuclear structure theory, the lifetime of the second 2+ state in neutron-rich O20,τ(22+)=150−30+80fs, and an estimate for the lifetime of the second 2+ state in C16 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 γ-transition line shapes of products of low-energy transfer and deep-inelastic processes in the reaction O18(7.0MeV/u)+Ta181. The requested sensitivity could only be reached owing to the excellent performances of the Advanced γ-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 O20 and with the no-core shell model for C16. The present measurement shows the power of electromagnetic observables, determined with high-precision γ 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. To test the predictive power of ab initio nuclear structure theory, the lifetime of the second 2+ state in neutron-rich 20O, tau(2+_2 ) = 150(+80-30) fs, and an estimate for the lifetime of the second 2+ state in 16C 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 femtoseconds range, by analyzing the Doppler-shifted gamma-transition line shapes of products of low-energy transfer and deep-inelastic processes in the reaction 18O (7.0 MeV/u) + 181Ta. The requested sensitivity could only be reached owing to the excellent performances of the AGATA gamma-tracking array, 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 20O, and with the no-core shell model for 16C. 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 lifetimes measurements in unexplored regions of the nuclear chart, including r-process nuclei, when intense ISOL-type beams become available.
- Subjects :
- Nuclear Theory (nucl-th)
nucl-th
Nuclear Theory
Nuclear Physics - Theory
Starke Wechselwirkung und exotische Kerne – Abteilung Blaum
FOS: Physical sciences
Nuclear Physics - Experiment
ddc:530
Nuclear Experiment (nucl-ex)
[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]
nucl-ex
Nuclear Structure
Nuclear Experiment
Subjects
Details
- Language :
- English
- ISSN :
- 24699985 and 24699993
- Database :
- OpenAIRE
- Journal :
- Phys.Rev.C, Phys.Rev.C, 2020, 101 (2), pp.021303. ⟨10.1103/PhysRevC.101.021303⟩, Physical Review C, Physical Review C, American Physical Society, 2020, 101 (2), pp.021303. ⟨10.1103/PhysRevC.101.021303⟩, Physical review / C 101(2), 021303 (2020). doi:10.1103/PhysRevC.101.021303, 'Physical Review C ', vol: 101, pages: 021303-1-021303-7 (2020)
- Accession number :
- edsair.doi.dedup.....eab0d08dff11b8d38bbeb1caf8d71f79