A1 Journal article (refereed)
Prominent Bump in the Two-Neutron Separation Energies of Neutron-Rich Lanthanum Isotopes Revealed by High-Precision Mass Spectrometry (2025)

Jaries, A., Stryjczyk, M., Kankainen, A., Eronen, T., Beliuskina, O., Dickel, T., Flayol, M., Ge, Z., Hukkanen, M., Mougeot, M., Nikas, S., Pohjalainen, I., Raggio, A., Reponen, M., Ruotsalainen, J., & Virtanen, V. (2025). Prominent Bump in the Two-Neutron Separation Energies of Neutron-Rich Lanthanum Isotopes Revealed by High-Precision Mass Spectrometry. Physical Review Letters, 134, Article 042501. https://doi.org/10.1103/PhysRevLett.134.042501

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Publication details

All authors or editors: Jaries, A.; Stryjczyk, M.; Kankainen, A.; Eronen, T.; Beliuskina, O.; Dickel, T.; Flayol, M.; Ge, Z.; Hukkanen, M.; Mougeot, M.; et al.

Journal or series: Physical Review Letters

ISSN: 0031-9007

eISSN: 1079-7114

Publication year: 2025

Publication date: 27/01/2025

Volume: 134

Article number: 042501

Publisher: American Physical Society

Publication country: United States

Publication language: English

DOI: https://doi.org/10.1103/PhysRevLett.134.042501

Publication open access: Not open

Publication channel open access: 

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/99903

Publication is parallel published:  https://doi.org/10.48550/arXiv.2408.06221

Abstract

We report on high-precision atomic mass measurements of 148-153La and 151Ce performed with the JYFLTRAP double Penning trap using the Phase-Imaging Ion-Cyclotron-Resonance technique. The masses of 152,153La were experimentally determined for the first time. We confirm the sharp kink in the two-neutron separation energies at the neutron number N=93 in the cerium (Z=58) isotopic chain. Our precision mass measurements of the most exotic neutron-rich lanthanum (Z=57) isotopes reveal a sudden increase in two-neutron separation energies from N=92 to N=93. Unlike in the cerium isotopic chain, the kink is not sharp but extends to N=94 forming a prominent bump. The gain in energy is about 0.4 MeV, making it one of the strongest changes in two-neutron separation energies over the whole chart of nuclides, away from nuclear shell closures. The results call for further studies to elucidate the structure of neutron-rich lanthanum isotopes.

Keywords: particle physics; nuclear physics

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Ministry reporting: Yes

VIRTA submission year: 2025

Preliminary JUFO rating: 3