In the realm of astrophysics and nuclear physics, a team of researchers from the University of Notre Dame, led by Dr. Timothy Dasher, has made a significant stride in understanding the late stages of stellar collapse, particularly in core-collapse supernovae (CCSNe). Their work, published in the journal Physical Review Letters, sheds light on the role of nuclear weak-interaction rates, specifically beta decay, in these cosmic events.
Core-collapse supernovae occur when massive stars run out of fuel and their cores implode, triggering a spectacular explosion. This process is accompanied by a burst of neutrinos and antineutrinos, which play a crucial role in the dynamics of the explosion and the synthesis of heavy elements. However, the exact details of these processes are not fully understood, and current models have significant uncertainties.
The team’s research focuses on the role of beta decay, a type of radioactive decay where a proton in an atom’s nucleus is transformed into a neutron, releasing an electron and an antineutrino. While previous studies have primarily focused on electron capture processes, this study is the first to incorporate global beta decay rates from a microscopic theory into CCSNe simulations.
Using a sophisticated theoretical framework, the researchers evaluated both electron capture and beta decay rates self-consistently. They employed the relativistic energy density functional theory and the finite-temperature quasiparticle random-phase approximation to model the complex nuclear processes occurring during stellar collapse.
The results of their simulations revealed a significant enhancement of antineutrino emissivity— the rate at which antineutrinos are emitted—by more than 4 orders of magnitude due to the inclusion of beta decay rates. Additionally, they observed a 3 orders of magnitude increase in antineutrino luminosity, the total energy emitted in the form of antineutrinos.
These findings have important implications for our understanding of core-collapse supernovae and the late-stage evolution of massive stars. By improving the prediction of antineutrino signals during the final stages of stellar death, these new rates could help constrain model uncertainties related to weak-interaction processes. This, in turn, could enhance our ability to interpret observations of supernova neutrinos and antineutrinos, providing deeper insights into the physics of these cataclysmic events.
While the direct practical applications for the energy industry may not be immediately apparent, a deeper understanding of these fundamental processes can contribute to the broader field of nuclear physics and astrophysics. This knowledge can inform the development of nuclear technologies and energy production methods, as well as our understanding of the universe’s nuclear processes.
Source: Physical Review Letters (2023)
This article is based on research available at arXiv.