The Neutrino Energy Loss of Nuclides via K-shell Continuum State Electron Capture in the Late Stage of Stellar Evolution

On the basis of Weinberg-Salam theory and in consideration of the influence of Coulomb effect on the electron gas in continnum state, an investiga- tion of the neutrino energy losses has been carried out for the nuclides 12C, 16O, 20Ne, 24Mg, 28Si, and 56 Fe in the process of free electron capture in the K-shell continuum under the circumstance of complete ionization. The results yielded with the method of Beaudet, Petrosian and Salpeter (BPS) and those of ours are compared, and this shows that for the circumstance of comparatively high temperature (e.g., T9 = 0.1 and T9 = 1, where T9 is the temperature in units of 109 K) these two kinds of results very well agree with each other. But for the circumstance of low temperature (e.g., T9 = 0.01 and T9 = 0.001) the neutrino energy losses of 16O, 20Ne, 24Mg, and 28Si found by BPS are in 10–70 times larger than our results. For the nuclide 12C, the former is in two orders of magnitude higher. Our research may have important significance for the investigation of the cooling mechanism in the late period of stellar evolution, especially in the period from the core collapse of white dwarfs to the stage of low temperature and medium density.