Programme

I.10 -- Invited, VCTP-50

Date: Thursday, 7 August 2025

Time: 14:00 - 14:40

Revisiting the anomaly in the production of 60Fe nucleus in massive stars

Samapti Lakshan (1), Le Tan Phuc (2,3), Deepak Pandit (4, 5), Srijit Bhattacharya (6), Balaram Dey (1), Nguyen Ngoc Anh (7) and Nguyen Quang Hung (2,3)

(1) Department of Physics, Bankura University, Bankura, West Bengal, India; (2) Institute of Fundamental and Applied Sciences, Duy Tan University, Ho Chi Minh City Vietnam; (3) Faculty of Natural Sciences, Duy Tan University, Da Nang City, Vietnam; (4) Variable Energy Cyclotron Centre, 1/AF-Bidhannagar, Kolkata, India; (5) Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai, India; (6) Department of Physics, Barasat Govt. College, Barasat, N 24 Pgs, Kolkata, India; (7) Phenikaa Institute for Advance Study (PIAS), PHENIKAA University, Hanoi, Vietnam

A number of experiments have detected the presence of two long-lived $^{26}$Al and $^{60}Fe radioisotopes and their ratio in both interstellar environments and terrestrial archives [1,2]. Those experimental detections provide fundamental probes for the nucleosynthesis in stars. In particular, a recent experiment, based on the gamma-decay spectroscopy of $^{60}$Fe produced via the beta-decay of $^{60}$Mn, has reported the enhanced production of $^{60}$Fe in massive stars, which is almost 2 times higher than previous studies [3]. Such an enhanced production strongly impacts the $^{60}$Fe/$^{26}$Al ratio, a primary source of uncertainties between gamma-ray telescope observations and supernova models. In this work, we revisit the $^{60}$Fe production problem by analyzing the influence of nuclear physics uncertainties, typically the nuclear level density (NLD) and $\gamma$-rays strength function (gSF), on both the neutron-captured and Maxwellian averaged cross sections of (n,$\gamma$)$^{60}$Fe reaction. We show that both the partial (angular-momentum dependent) NLDs and low-energy gSF, which have not been measured, are the main sources that affect the $^{60}$Fe production. References: [1] W. A. Mahoney et al., Astrophys. J. 262, 742 (1982). [2] W. R. Binns et al., Science 352, 677 (2016). [3] A. Spyrou et al., Nat. Comm. 15, 9608 (2024).

Presenter: Nguyen Quang Hung