Sunday 30 March 2025
The investigation of weak rates for odd-A nuclei has long been a crucial aspect of studying presupernova evolution in massive stars. Weak interaction properties, particularly Gamow-Teller transitions and beta decay rates, play a significant role in astrophysical processes such as nucleosynthesis and supernovae simulations.
Researchers have traditionally relied on the Brink-Axel hypothesis to calculate these weak rates, which simplifies the process but may not accurately capture the complex nuclear physics involved. A new approach, however, has been developed by scientists who employed a deformed pn-QRPA model to calculate Gamow-Teller strength distributions and beta decay rates for selected odd-A nuclei.
The study focused on two specific nuclei, 45Sc and 55Mn, which are crucial for presupernova evolution simulations. The researchers used the deformed pn-QRPA model to calculate the GT strength distributions from all parent excited states, providing a more accurate representation of the weak rates than traditional methods.
The results show that the calculated beta decay rates are in good agreement with large-scale shell model calculations and demonstrate the importance of including deformation effects in the calculation. The researchers also found that the positron capture rates are highly sensitive to temperature, increasing as the core temperature rises.
The study’s findings have significant implications for presupernova evolution simulations, which rely on accurate weak rate calculations to accurately model the late stages of massive star evolution. The results highlight the need for more precise calculations of weak rates and demonstrate the effectiveness of the deformed pn-QRPA model in achieving this goal.
In addition to its relevance to presupernova evolution, this study also has implications for other areas of nuclear physics, such as neutrinoless double beta decay and nuclear reaction simulations. The development of a more accurate method for calculating weak rates could lead to breakthroughs in our understanding of these complex phenomena.
The investigation’s authors have made their results publicly available, providing a valuable resource for the scientific community. As researchers continue to refine their methods and push the boundaries of what is possible with computer simulations, this study serves as an important reminder of the importance of accurate weak rate calculations in achieving a deeper understanding of the universe.
Cite this article: “Accurate Calculation of Weak Rates for Presupernova Evolution Simulations”, The Science Archive, 2025.
Weak Rates, Odd-A Nuclei, Presupernova Evolution, Gamow-Teller Transitions, Beta Decay Rates, Deformed Pn-Qrpa Model, Shell Model Calculations, Positron Capture Rates, Temperature Dependence, Nuclear Physics.
