Seminarium Fizyki Jądra Atomowego
sala 1.01, ul. Pasteura 5
2024-10-10 (10:15) 
dr Nikita Bernier (Departament of Physics & Astronomy University of the Western Cape and National Institute for Theoretical and Computational Sciences, South Africa)
Nuclear Structure of Neutron-Rich 128In using β-decay Spectroscopy
Neutron-rich indium isotopes (Z = 49) near the well-known magic numbers at Z = 50 and N = 82 are prime candidates to study the evolving shell structure observed in exotic nuclei [1, 2]. Additionally, the properties of nuclei around the doubly magic 132Sn have direct implications for astrophysical models [3, 4], leading to the corresponding neutron-shell closure nuclei around N = 82 and the second r-process abundance peak at A ≈ 130 and the corresponding waiting-point nuclei around N = 82. The β decay of 128Cd into 128In was investigated using the GRIFFIN spectrometer [5] at TRIUMF, which is capable of performing spectroscopy down to rates of 0.1 pps. In addition to the four previously observed excited states [6], 32 new transitions and 11 new states have been observed. These new results are compared with recent phenomenological shell model calculations as well as ab initio predictions from the valence-space in-medium similarity renormalization group (IMSRG) [7–9], based on two- and three-nucleon forces derived from chiral effective field theory. This new experimental information highlights the challenges for both phenomenological and ab initio calculations to reproduce the full complexity of heavy nuclei four nucleon-holes away from thedoubly magic 132Sn.
[1] K. Jones et al., Direct reaction measurements with a 132Sn radioactive ion beam, Phys. Rev. C 84, 034601 (2011).
[2] D. Rosiak et al. (MINIBALL and HIE-ISOLDE Collaborations), Enhanced Quadrupole and Octupole Strength in Doubly Magic 132Sn, Phys. Rev. Lett. 121, 252501 (2018).
[3] M. Mumpower et al., Sensitivity studies for the main r process: β-decay rates, AIP Advances 4, 041009 (2014).
[4] M. Mumpower et al., The impact of individual nuclear properties on r-process nucleosynthesis, Prog. in Part. and Nucl. Phys. 86, 86 (2016).[5] C. Svensson and A. Garnsworthy, The GRIFFIN spectrometer, Hyperfne Interact. 225, 127 (2016).
[6] B. Fogelberg, Systematic Trends in the Level Structure of Neutron Rich Nuclei, Proceedings of the International Conference Nuclear Data for Science and Technology, Mito, Japan 93, 837 (1988).
[7] J. Holt et al., Three-nucleon forces and spectroscopy of neutron-rich calcium isotopes, Phys. Rev. C 90, 024312 (2014).
[8] S. Bogner et al., Nonperturbative Shell-Model Interactions from the In-Medium Similarity Renormalization Group, Phys. Rev. Lett. 113, 142501 (2014).
[9] S. Stroberg et al., Nucleus-Dependent Valence-Space Approach to Nuclear Structure, Phys. Rev. Lett. 118, 032502 (2017).
[1] K. Jones et al., Direct reaction measurements with a 132Sn radioactive ion beam, Phys. Rev. C 84, 034601 (2011).
[2] D. Rosiak et al. (MINIBALL and HIE-ISOLDE Collaborations), Enhanced Quadrupole and Octupole Strength in Doubly Magic 132Sn, Phys. Rev. Lett. 121, 252501 (2018).
[3] M. Mumpower et al., Sensitivity studies for the main r process: β-decay rates, AIP Advances 4, 041009 (2014).
[4] M. Mumpower et al., The impact of individual nuclear properties on r-process nucleosynthesis, Prog. in Part. and Nucl. Phys. 86, 86 (2016).[5] C. Svensson and A. Garnsworthy, The GRIFFIN spectrometer, Hyperfne Interact. 225, 127 (2016).
[6] B. Fogelberg, Systematic Trends in the Level Structure of Neutron Rich Nuclei, Proceedings of the International Conference Nuclear Data for Science and Technology, Mito, Japan 93, 837 (1988).
[7] J. Holt et al., Three-nucleon forces and spectroscopy of neutron-rich calcium isotopes, Phys. Rev. C 90, 024312 (2014).
[8] S. Bogner et al., Nonperturbative Shell-Model Interactions from the In-Medium Similarity Renormalization Group, Phys. Rev. Lett. 113, 142501 (2014).
[9] S. Stroberg et al., Nucleus-Dependent Valence-Space Approach to Nuclear Structure, Phys. Rev. Lett. 118, 032502 (2017).