Abstract
We report here the first observation of the 02+ state of He8, which has been predicted to feature the condensatelike α+n2+n2 cluster structure. We show that this state is characterized by a spin parity of 0+, a large isoscalar monopole transition strength, and the emission of a strongly correlated neutron pair, in line with theoretical predictions. Our finding is further supported by the state-of-the-art microscopic α+4n model calculations. The present results may lead to new insights into clustering in neutron-rich nuclear systems and the pair correlation and condensation in quantum many-body systems under strong interactions.
Original language | English |
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Article number | 242501 |
Journal | Physical Review Letters |
Volume | 131 |
Issue number | 24 |
DOIs | |
State | Published - Dec 15 2023 |
Externally published | Yes |
Funding
We thank the RIKEN Nishina Center accelerator staff and RIPS team for providing the high-quality beams. We thank Y. Funaki, M. N. Harakeh, H. Horiuchi, Y. Kanada-En’yo, Z. Kohley, Y. Kondo, T. Myo, H. J. Ong, A. Tohsaki, and S. M. Wang for discussions. This work was supported by the National Key R&D Program of China (Grants No. 2022YFA1605100, No. 2023YFE0101500, No. 2023YFE0101600), the National Natural Science Foundation of China (Grants No. 12027809, No. 12275006, No. 11961141003, No. U1967201, No. 12175042, No. 12335007), and the JSPS KAKENHI Grants of Japan No. 17K14262 [Grant-in-Aid for Young Scientists (B)], the State Key Laboratory of Nuclear Physics and Technology, Peking University (No. NPT2022ZZ02). Numerical computations were performed at the Yukawa Institute Computer Facility in Kyoto University. We also thank Z. X. Cao, L. H. Lv, S. Deguchi, Y. Kondo, and Y. Nakayama for their support during the experiment.