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Ab Initio Calculations of β-Decay Half-Lives for N=50 Neutron-Rich Nuclei

Zhen Li1,2,3,*, Takayuki Miyagi4,†, and Achim Schwenk1,2,3,‡

  • *Contact author: zhen.li1@tu-darmstadt.de
  • †Contact author: miyagi@nucl.ph.tsukuba.ac.jp
  • ‡Contact author: schwenk@physik.tu-darmstadt.de
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Phys. Rev. Lett. 136, 182501 – Published 5 May, 2026

DOI: https://doi.org/10.1103/xjv9-t6sn

Abstract

β-decay rates of extreme neutron-rich nuclei remain largely unknown experimentally, while they are critical inputs for r-process nucleosynthesis. We present first ab initio calculations of total β-decay half-lives, with a focus on N=50 nuclei. Starting from nuclear forces and currents based on chiral effective field theory, we use the in-medium similarity renormalization group to consistently derive valence-space Hamiltonians and weak operators, from which we calculate the nuclear states involved and the Gamow-Teller transition strengths, without phenomenological adjustments. In addition, we explore effects of first-forbidden contributions. Our results show that the inclusion of two-body currents increases the total half-lives, which then show good agreement with the existing experimental data, thereby validating the predictive capability of our approach.

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Phys. Rev. Lett. 136, 182501– Published 5 May, 2026
  • Received 11 September 2025
  • Revised 24 February 2026
  • Accepted 20 March 2026
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