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DOE OSTI · 3001912

Measurements of Gamow-Teller transitions from 59 Co via the 59 Co ⁢(𝑡, 3 He +𝛾) charge-exchange reaction and its application to the stellar electron-capture rates

Gao, B. [Chinese Academy of Sciences, Lanzhou (China); University of Chinese Academy of Sciences, Beijing (China)] (ORCID:0000000279113950)·Giraud, S. [Michigan State University, East Lansing, MI (United States)] (ORCID:0000000165425091)·Lv, C. J. [Shanghai Jiao Tong University (China)] (ORCID:0000000293921321)·Sun, Y. [Shanghai Jiao Tong University (China)] (ORCID:0000000214114135)·Zegers, R. G. T. [Michigan State University, East Lansing, MI (United States)] (ORCID:0000000160765898)·Wang, L. J. [Southwest University, Chongqing (China)]·Niu, Y. F. [Lanzhou University (China); China Institute of Atomic Energy, Beijing (China); Chinese Academy of Sciences, Lanzhou (China)] (ORCID:0000000310291887)·Ash, J. [Michigan State University, East Lansing, MI (United States)]·Ayyad-Limonge, Y. [Michigan State University, East Lansing, MI (United States)] (ORCID:0000000186044976)·Bazin, D. [Michigan State University, East Lansing, MI (United States)] (ORCID:0000000256639693)·Biswas, S. [Michigan State University, East Lansing, MI (United States)]·Brown, B. A. [Michigan State University, East Lansing, MI (United States)] (ORCID:0000000261111906)·Chen, J. [Michigan State University, East Lansing, MI (United States)] (ORCID:0000000304477466)·Farris, P. [Michigan State University, East Lansing, MI (United States)]·Gade, A. [Michigan State University, East Lansing, MI (United States)] (ORCID:0000000188250976)·Ginter, T. [Michigan State University, East Lansing, MI (United States)] (ORCID:0000000245059888)·Grinder, M. [Michigan State University, East Lansing, MI (United States)]·Hill, A. M. [Michigan State University, East Lansing, MI (United States)]·Iwasaki, H. [Michigan State University, East Lansing, MI (United States)] (ORCID:000000030750380X)·Kwan, E. [Michigan State University, East Lansing, MI (United States)]·Li, K. A. [Chinese Academy of Sciences, Lanzhou (China); University of Chinese Academy of Sciences, Beijing (China)]·Longfellow, B. [Michigan State University, East Lansing, MI (United States)]·Maher, C. [Michigan State University, East Lansing, MI (United States)]·Ndayisabye, F. [Michigan State University, East Lansing, MI (United States)] (ORCID:0009000489732888)·Noji, S. [Michigan State University, East Lansing, MI (United States)] (ORCID:0000000306995443)·Pereira, J. [Michigan State University, East Lansing, MI (United States)]·Revel, A. [Michigan State University, East Lansing, MI (United States)] (ORCID:0000000327109287)·Rhodes, D. [Michigan State University, East Lansing, MI (United States)] (ORCID:0009000178193952)·Sanchez, A. [Michigan State University, East Lansing, MI (United States)] (ORCID:0000000295525437)·Schmitt, J. [Michigan State University, East Lansing, MI (United States)]·Sumithrarachchi, C. [Michigan State University, East Lansing, MI (United States)]·Tang, X. [Chinese Academy of Sciences, Lanzhou (China); University of Chinese Academy of Sciences, Beijing (China)] (ORCID:0000000200294999)·Wang, S. C. [Chinese Academy of Sciences, Lanzhou (China)]·Weisshaar, D. [Michigan State University, East Lansing, MI (United States)]
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Abstract

Electron-capture reactions on iron-group nuclei play a crucial role in the late stages of massive star evolution. Since stellar evolution simulations depend on accurate electron-capture rates—which are highly sensitive to the detailed Gamow-Teller (GT) strength distributions—reliable theoretical models are essential. However, experimental data on GT strength distributions are scarce. High-resolution measurements are therefore vital for benchmarking and improving these theoretical calculations. To provide high-resolution data on Gamow-Teller strength distributions of iron-group nuclei and to compare these results with theoretical calculations within this mass region. Differential cross sections for the 59 Co ⁢(𝑡, 3 He)⁢ 59 Fe charge-exchange reaction at 115 MeV/u were measured using the S800 spectrometer. Furthermore, to resolve individual levels that are not distinguishable in the S800 particle singles data, coincident 𝛾 rays from the 59 Fe residual nucleus were detected by using the Gamma-Ray Energy Tracking In-beam Nuclear Array 𝛾-ray tracking array. Here, the Gamow-Teller transition strength distribution from the ground state of 59 Co to 59 Fe was extracted up to an excitation energy of 10 MeV. Additionally, transition strengths for several low-lying states were determined from coincident 𝛾-ray measurements. Electron-capture rates calculated using the present data indicate that these low-lying states contribute significantly to the overall rates in relevant stellar environments. The experimental results show reasonable agreement with theoretical predictions based on both shell-model and projected shell-model calculations. High-resolution data on Gamow-Teller strength distributions—particularly for individual low-lying states—are essential for accurately determining electron-capture rates in iron-group nuclei. Coincident 𝛾-ray measurements provide a powerful tool for obtaining such detailed information. While the present work demonstrates that shell-model calculations successfully reproduce the experimental results, such comparisons are scarce and more experimental data are desirable.

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59 ≤ A ≤ 89Charge-exchange reactionsElectron & muon captureNuclear astrophysicsNuclear physics of explosive environmentsNuclear reactionsNuclear structure & decays

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Gao, B. [Chinese Academy of Sciences, Lanzhou (China); University of Chinese Academy of Sciences, Beijing (China)] (ORCID:0000000279113950), Giraud, S. [Michigan State University, East Lansing, MI (United States)] (ORCID:0000000165425091), Lv, C. J. [Shanghai Jiao Tong University (China)] (ORCID:0000000293921321), Sun, Y. [Shanghai Jiao Tong University (China)] (ORCID:0000000214114135), Zegers, R. G. T. [Michigan State University, East Lansing, MI (United States)] (ORCID:0000000160765898), Wang, L. J. [Southwest University, Chongqing (China)], Niu, Y. F. [Lanzhou University (China); China Institute of Atomic Energy, Beijing (China); Chinese Academy of Sciences, Lanzhou (China)] (ORCID:0000000310291887), Ash, J. [Michigan State University, East Lansing, MI (United States)], Ayyad-Limonge, Y. [Michigan State University, East Lansing, MI (United States)] (ORCID:0000000186044976), Bazin, D. [Michigan State University, East Lansing, MI (United States)] (ORCID:0000000256639693), Biswas, S. [Michigan State University, East Lansing, MI (United States)], Brown, B. A. [Michigan State University, East Lansing, MI (United States)] (ORCID:0000000261111906), Chen, J. [Michigan State University, East Lansing, MI (United States)] (ORCID:0000000304477466), Farris, P. [Michigan State University, East Lansing, MI (United States)], Gade, A. [Michigan State University, East Lansing, MI (United States)] (ORCID:0000000188250976), Ginter, T. [Michigan State University, East Lansing, MI (United States)] (ORCID:0000000245059888), Grinder, M. [Michigan State University, East Lansing, MI (United States)], Hill, A. M. [Michigan State University, East Lansing, MI (United States)], Iwasaki, H. [Michigan State University, East Lansing, MI (United States)] (ORCID:000000030750380X), Kwan, E. [Michigan State University, East Lansing, MI (United States)], Li, K. A. [Chinese Academy of Sciences, Lanzhou (China); University of Chinese Academy of Sciences, Beijing (China)], Longfellow, B. [Michigan State University, East Lansing, MI (United States)], Maher, C. [Michigan State University, East Lansing, MI (United States)], Ndayisabye, F. [Michigan State University, East Lansing, MI (United States)] (ORCID:0009000489732888), Noji, S. [Michigan State University, East Lansing, MI (United States)] (ORCID:0000000306995443), Pereira, J. [Michigan State University, East Lansing, MI (United States)], Revel, A. [Michigan State University, East Lansing, MI (United States)] (ORCID:0000000327109287), Rhodes, D. [Michigan State University, East Lansing, MI (United States)] (ORCID:0009000178193952), Sanchez, A. [Michigan State University, East Lansing, MI (United States)] (ORCID:0000000295525437), Schmitt, J. [Michigan State University, East Lansing, MI (United States)], Sumithrarachchi, C. [Michigan State University, East Lansing, MI (United States)], Tang, X. [Chinese Academy of Sciences, Lanzhou (China); University of Chinese Academy of Sciences, Beijing (China)] (ORCID:0000000200294999), Wang, S. C. [Chinese Academy of Sciences, Lanzhou (China)], Weisshaar, D. [Michigan State University, East Lansing, MI (United States)]. 2025-08-22. Measurements of Gamow-Teller transitions from 59 Co via the 59 Co ⁢(𝑡, 3 He +𝛾) charge-exchange reaction and its application to the stellar electron-capture rates. https://doi.org/10.1103/j2jj-d9q3

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