Abstract:

(Anti)neutrino luminosities and spectra arising from neutral- and charged- current weak reactions with a hot nucleus ⁵⁶Fe are computed for pre-supernova conditions. The role of thermal processes was specially studied. It is found that thermodynamically consistent consideration of thermal e ects in the framework of the thermal quasiparticle random phase approximation produces a higher luminosity and a harder spectrum of electron neutrinos in compare with the standard technique based on the large-scale shell model weak-interaction rates. It is shown that in the context of electron antineutrino generation, the neutrino- antineutrino pair emission via nuclear de-excitation (ND) is at least as important as the electron-positron pair annihilation process. We also show that avor oscillations enhance the high-energy contribution of the ND process to the electron antineutrino ux. This could potentially be important for pre-supernova antineutrino registration by the Earth’s detectors.