Stellar ${\beta }^{\pm }$ decay rates of iron isotopes and its implications in astrophysics

Abstract

$\beta$-decay and positron decay are believed to play a consequential role during the late phases of stellar evolution of a massive star culminating in a supernova explosion. Recently the microscopic calculation of weak-interaction mediated rates on key isotopes of iron was introduced using the proton-neutron quasiparticle random phase approximation (pn-QRPA) theory with improved model parameters. Here I discuss in detail the improved calculation of ${\beta }^{\pm }$ decay rates for iron isotopes (${}^{54,55,56}$Fe) in stellar environment. The pn-QRPA theory allows a microscopic "state-by-state" calculation of stellar rates as explained later in text. Excited state Gamow-Teller distributions are much different from ground state and a microscopic calculation of decay rates from these excited states greatly increases the reliability of the total decay rate calculation specially during the late stages of stellar evolution. The reported decay rates are also compared with earlier calculations. The positron decay rates are in reasonable agreement with the large-scale shell model calculation. The main finding of this work includes that the stellar $\beta$-decay rates of ${}^{54,55,56}$Fe are around 3 -- 5 orders of magnitude smaller than previously assumed and hence irrelevant for the determination of the evolution of $Y_e$ during the presupernova phase of massive stars. The current work discourages the inclusion of ${}^{55,56}$Fe in the list of key stellar $\beta$-decay nuclei as suggested by former simulation results.

35 pages, 15 figures

References in corpus (9)

• Gamow-Teller transitions and deformation in the proton-neutron random phase approximation
• Comparative study of Gamow-Teller strength distributions in the odd-odd nucleus 50V and its impact on electron capture rates in astrophysical environments
• Weak-interaction mediated rates on iron isotopes for presupernova evolution of massive stars
• Gamow-Teller transitions from 24Mg and its impact on the electron capture rates in the O + Ne + Mg cores of stars
• Neutrino energy loss rates and positron capture rates on ${}^{55}$Co for presupernova and supernova physics
• Uncertainties in the $0\nu \beta \beta$--decay nuclear matrix elements
• Stellar neutrino energy loss rates due to ${}^{24}$Mg suitable for O+Ne+Mg core simulations
• Expanded calculations of pn-QRPA electron capture rates on ${}^{55}$Co for presupernova and supernova physics
• Detailed microscopic calculation of stellar electron and positron capture rates on ${}^{24}$Mg for O+Ne+Mg core simulations

Cited by in corpus (7)

• Unique first-forbidden $\beta$-decay transitions in odd-odd and even-even heavy nuclei
• rp-Process weak-interaction mediated rates of waiting-point nuclei
• Neutrino cooling rates due to ${}^{54,55,56}$Fe for presupernova evolution of massive stars
• Energy Rates Due to Weak Decay Rates of Vanadium Isotopes in Stellar Environment
• Gamow-Teller strength distribution in proton-rich nucleus ${}^{57}$Zn and its implications in astrophysics
• Nuclear inputs of key iron isotopes for core-collapse modeling and simulation
• Gamow-Teller strength distributions and stellar weak-interaction rates for ${}^{76}$Ge and ${}^{82}$Se using the deformed pn-QRPA model