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.
Testing ab initio nuclear structure in neutron-rich nuclei: Lifetime measurements of second 2+ state in C 16 and O 20 / Ciemala, M.; Ziliani, S.; Crespi, F. C. L.; Leoni, S.; Fornal, B.; Maj, A.; Bednarczyk, P.; Benzoni, G.; Bracco, A.; Boiano, C.; Bottoni, S.; Brambilla, S.; Bast, M.; Beckers, M.; Braunroth, T.; Camera, F.; Cieplicka-Orynczak, N.; Clement, E.; Coelli, S.; Dorvaux, O.; Erturk, S.; De France, G.; Fransen, C.; Goldkuhle, A.; Grebosz, J.; Harakeh, M. N.; Iskra, L. W.; Jacquot, B.; Karpov, A.; Kicinska-Habior, M.; Kim, Y.; Kmiecik, M.; Lemasson, A.; Lenzi, S. M.; Lewitowicz, M.; Li, H.; Matea, I.; Mazurek, K.; Michelagnoli, C.; Matejska-Minda, M.; Million, B.; Muller-Gatermann, C.; Nanal, V.; Napiorkowski, P.; Napoli, D. R.; Palit, R.; Rejmund, M.; Schmitt, C.; Stanoiu, M.; Stefan, I.; Vardaci, E.; Wasilewska, B.; Wieland, O.; Zieblinski, M.; Zielinska, M.; Atac, A.; Barrientos, D.; Birkenbach, B.; Boston, A. J.; Cederwall, B.; Charles, L.; Collado, J.; Cullen, D. M.; Desesquelles, P.; Domingo-Pardo, C.; Dudouet, J.; Eberth, J.; Gonzalez, V.; Goupil, J.; Harkness-Brennan, L. J.; Hess, H.; Judson, D. S.; Jungclaus, A.; Korten, W.; Labiche, M.; Lefevre, A.; Menegazzo, R.; Mengoni, D.; Nyberg, J.; Perez-Vidal, R. M.; Podolyak, Z.; Pullia, A.; Recchia, F.; Reiter, P.; Saillant, F.; Salsac, M. D.; Sanchis, E.; Stezowski, O.; Theisen, C.; Valiente-Dobon, J. J.; Holt, J. D.; Menendez, J.; Schwenk, A.; Simonis, J.. - In: PHYSICAL REVIEW C. - ISSN 2469-9985. - 101:2(2020). [10.1103/PhysRevC.101.021303]
Testing ab initio nuclear structure in neutron-rich nuclei: Lifetime measurements of second 2+ state in C 16 and O 20
Vardaci E.;
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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
