Enhanced antineutrino emission from $β$ decay in core-collapse supernovae with self-consistent weak decay rates

Abstract

Nuclear weak-interaction rates are known to exert a prominent effect in the late-stages of stellar collapse. Despite their importance, most studies to date on core-collapse supernovae (CCSNe) have focused primarily on the effects of electron captures, generally neglecting $β$ decay contributions. In this Letter, we present the first CCSNe simulation incorporating global $β$ decay rates from a microscopic theory. These are enabled by a large-scale evaluation of both electron capture and $β$ decay rates, obtained self-consistently utilizing the relativistic energy density functional theory and finite-temperature quasiparticle random-phase approximation. We find a significant enhancement of antineutrino emissivity by more than 4 orders of magnitude due to the inclusion of $β$ decay rates, as well as 3 orders of magnitude for antineutrino luminosity. It is expected that these new rates could help us constrain the model uncertainties related to weak-interaction processes, improving the prediction of antineutrino signal during the final stages of stellar death and potentially influencing the late-stage evolution of massive stars.

Figures (3)

• Figure 1: The antineutrino emissivity as a function of antineutrino energy at 4 sets of thermodynamic conditions during the CCSNe evolution of a $20M_\odot$ progenitor (a)--(d). The positron capture on free neutrons, $e^+ + n$, contribution (solid line), as a baseline in all models, is compared to emissivities where the $\beta$ decay rates are explicitly included either from the FT-QRPA calculations in this work (dashed line) or the shell-model data (dotted line) LANGANKE20011Zha2019.
• Figure 2: Partial contribution of individual nuclei to the total antineutrino emissivity at $E_{\bar{\nu}_e} = 3$ MeV (a,c) and $E_{\bar{\nu}_e} = 8$ MeV (b,d) at conditions corresponding to the onset of the collapse (a,b) and closer to the time of the bounce (c,d). All rates are obtained with the FT-QRPA model.
• Figure 3: The time-evolution of the (anti)neutrino luminosity at 500 km from the core (a,c) and the average (anti)neutrino energy (b,d) for 15$M_\odot$ (a, b) and 20$M_\odot$ (c, d) progenitors. Results are displayed for the positron capture $e^+ + n$ baseline (solid line) together with the predictions of the FT-QRPA neutrinos (dotted line) and antineutrinos (dashed line).