α-Clustering in atomic nuclei from first principles with statistical learning and the Hoyle state character

T Otsuka; T Abe; T Yoshida; Y Tsunoda; N Shimizu; N Itagaki; Y Utsuno; J Vary; P Maris; H Ueno

doi:10.1038/s41467-022-29582-0

α-Clustering in atomic nuclei from first principles with statistical learning and the Hoyle state character

Nat Commun. 2022 Apr 27;13(1):2234. doi: 10.1038/s41467-022-29582-0.

Authors

T Otsuka^{1

2

3}, T Abe^{4

5}, T Yoshida^{5

6}, Y Tsunoda⁵, N Shimizu⁵, N Itagaki⁷, Y Utsuno^{8

5}, J Vary⁹, P Maris⁹, H Ueno⁴

Affiliations

¹ Department of Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo, 113-0033, Japan. otsuka@phys.s.u-tokyo.ac.jp.
² RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan. otsuka@phys.s.u-tokyo.ac.jp.
³ Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki, 319-1195, Japan. otsuka@phys.s.u-tokyo.ac.jp.
⁴ RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.
⁵ Center for Nuclear Study, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo, 113-0033, Japan.
⁶ Research Organization for Information Science and Technology, 2-4, Shirakata, Tokai, Ibaraki, 319-1106, Japan.
⁷ Yukawa Institute for Theoretical Physics, Kyoto University, Kitashirakawa Oiwake-Cho, Kyoto, 606-8502, Japan.
⁸ Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki, 319-1195, Japan.
⁹ Department of Physics and Astronomy, Iowa State University, Ames, IA, 50011, USA.

Abstract

A long-standing crucial question with atomic nuclei is whether or not α clustering occurs there. An α particle (helium-4 nucleus) comprises two protons and two neutrons, and may be the building block of some nuclei. This is a very beautiful and fascinating idea, and is indeed plausible because the α particle is particularly stable with a large binding energy. However, direct experimental evidence has never been provided. Here, we show whether and how α(-like) objects emerge in atomic nuclei, by means of state-of-the-art quantum many-body simulations formulated from first principles, utilizing supercomputers including K/Fugaku. The obtained physical quantities exhibit agreement with experimental data. The appearance and variation of the α clustering are shown by utilizing density profiles for the nuclei beryllium-8, -10 and carbon-12. With additional insight by statistical learning, an unexpected crossover picture is presented for the Hoyle state, a critical gateway to the birth of life.

Abstract

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