Establishing the 40Ca(p,pα) reaction at 392 MeV under quasi-free scattering conditions
Abstract The (p, pα) reaction offers a direct means to probe preformed α-cluster structures in nuclei under quasi-free scattering conditions. Previous studies around 100 MeV provided valuable insights into α clustering, but quantitative comparison with microscopic cluster wave functions remained limited due to strong distortion effects. At higher energies, the reaction mechanism becomes simpler and the distorted-wave impulse approximation (DWIA) provides a more reliable framework for quantitative analysis. In the present work, the 40Ca(p,pα) reaction was measured at an incident energy of 392 MeV using the high-resolution Grand Raiden and LAS spectrometers at RCNP. Despite the small cross section in this energy region, the achieved resolution allowed clear separation of the ground and excited states of the residual 36Ar nucleus, and corresponding momentum distributions were extracted. DWIA calculations using a Woods–Saxon α + 36Ar bound-state wave function yielded an experimental spectroscopic factor of $S_{\mathrm{FAC}}^{\mathrm{WS}} = 0.51 \pm 0.05$, consistent with the previous result at 101.5 MeV (0.52 ± 0.23). This agreement demonstrates that the reaction mechanism is well described across a wide energy range. The present study establishes the feasibility of high-precision (p, pα) measurements at several hundred MeV and highlights their potential as a quantitative probe of α clustering in medium-mass nuclei, forming the basis for systematic studies in both stable and unstable systems.
Authors
- M. Dozono (ORCID: https://orcid.org/0000-0002-0891-4283)
- K. Yoshida (ORCID: https://orcid.org/0000-0002-0319-8214)
- K. Miki (ORCID: https://orcid.org/0000-0001-8067-9882)
- S. Umemoto
- S. Ota (ORCID: https://orcid.org/0000-0001-8855-4785)
- S. Ogio
- K. I. Hahn (ORCID: https://orcid.org/0000-0002-9250-6484)
- Yuya Honda
- Y. Q. Li
- T. Furuno (ORCID: https://orcid.org/0000-0002-1733-8353)
- Xuan Wang (ORCID: https://orcid.org/0000-0002-5173-2610)
- Sunji Kim
- Fumitaka Endo
- Kazuyuki Ogata (ORCID: https://orcid.org/0000-0003-2487-4805)
- E. Ideguchi (ORCID: https://orcid.org/0000-0002-7424-9664)
- Yoshiki Chazono (ORCID: https://orcid.org/0009-0005-7802-6336)
- Jichao Zhang (ORCID: https://orcid.org/0000-0003-3855-4378)
- S. Kawase (ORCID: https://orcid.org/0000-0001-5720-108X)
- Shoya Ogawa (ORCID: https://orcid.org/0000-0003-0900-2486)
- D. Beaumel
- Riku Matsumura
- M. Petri
- J. Zenihiro (ORCID: https://orcid.org/0000-0001-5917-7677)
- Junki Tanaka (ORCID: https://orcid.org/0000-0001-6616-8736)
- Keiko Higuchi
- Y. Matsuda
- Qite Li (ORCID: https://orcid.org/0000-0001-8530-203X)
- Motoki Murata (ORCID: https://orcid.org/0009-0001-2577-6783)
- Y. Kubota (ORCID: https://orcid.org/0000-0003-3683-0500)
- Nobuyuki Kobayashi
- Hiroaki Shibakita
- Keita Kawata
- Atsushi TAMII
- Takayuki Yano
- Soki Sakajo
- M. Khandelwal (ORCID: https://orcid.org/0009-0009-1846-8668)
- Nikhil Mozumdar
- Y Maeda
- Tomoya Nakada
- Katsuhide Itsuno
- Byungsik Hong
- Futa Saito
- Ryota Iwasaki
- Zaihong Yang
- Azusa Inoue
- Kohki Yasumura
- Yifan Lin
- Stefan Typel
- Mingyu Kim
- Yohei Sasagawa
- Yuto Hijikata
- Ryosuke Yoshida
- Hideya Sonoda
- Nobuhiro Yamasaki
- Shunpei Yamazaki
- Maoto Mitsui
- Yumaro Suzuki
- Ryotaro Tsuji
- Hide Nakama
- Jiawei Bian
- Ryo Kato
- Riku Yamamoto
- Fumiya Furukawa
- Stefanos Paschalis
- Fengyi Chen
- Kaijie Zhou
- Guo Wenhao
- J Cai
- Cheng Wang
- Jongwon Hwang
- Takahiro Kawabata
- CheongSoo Lee
- Tomohiro Uesaka
- Deuk Soon Ahn
- Takafumi Sato
- Serge Franchoo
- Geonhee Oh
- Taichi Miyagawa
- Thomas Pohl
- Taiki Sugiyama
- Gen Ikemizu
Institutions
- Darmstadt University of Applied Sciences (DE)
- University of Fukui (JP)
- University of Miyazaki (JP)
- Fukui University of Technology (JP)
- Kyushu University (JP)
- Pioneer (United States) (US)
- Osaka University of Economics (JP)
- Konan University (JP)
- GSI Helmholtz Centre for Heavy Ion Research (DE)
- University of Oslo (NO)
- York University (CA)
- Korea University (KR)
- Tohoku University (JP)
- Peking University (CN)
- Japan Radioisotope Association (JP)
- Kyoto University (JP)
- Technische Universität Darmstadt (DE)
- Tohoku University Hospital (JP)
- Advanced Energy (United States) (US)
- Institute for Basic Science (KR)
- Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (FR)
- RIKEN Nishina Center (JP)
- University of York (GB)
- Technical University of Munich (DE)
- Saitama University (JP)
- Michigan State University (US)
- The University of Osaka (JP)
Publication Details
- Journal
- Progress of Theoretical and Experimental Physics
- Published
- 2026-02-17
- DOI
- https://doi.org/10.1093/ptep/ptag038
- Primary Topic
- Nuclear physics research studies
- Type
- article
- Field-Weighted Citation Impact
- 0.00