Matter Effects on Neutrino Oscillations in Different Supernova Models

Abstract

It has been realized that the shock wave effects play an important role in neutrino oscillations during the supernova explosion. In recent years, with the development of simulations about supernova explosion, we have a better understanding about the density profiles and the shock waves in supernovae than before. It has been shown that the appearance of shock waves not only varies with time, but is also affected by the mass of the supernova. When the mass of the supernova happens to be in a certain range (e.g. it equals 10.8 times the mass of the sun), there might be a reverse shock wave, another sudden change of density except the forward shock wave, emerging in the supernova.In addition, there are some other time-dependent changes of density profiles in different supernova models. Because of these complex density profiles, the expression of the crossing probability at the high resonance, PH , which we used previously would be no longer applicable. In order to get more accurate and reasonable results, we use the data of density profiles in three different supernova models obtained from simulations to study the variations of Ps (the survival probability of νe → νe), as well as Pc (the conversion probability of νx → νe). It is found that the mass of the supernova does make a difference on the behavior of Ps, and affects Pc at the same time. With the results of Ps and Pc, we can estimate the number of νe remained after they go through the matter in the supernova.

Decoherence and oscillations of supernova neutrinos

“…The possibility of two layers and two jumps is realized when there are two shock wave fronts (one can move inward); see, e.g., [47]. In this case the first layer is the one between the shock fronts and the second one is above the outer shock.…”

Effects of a reverse shock wave on neutrino oscillations in a new supernova model

“…For convenience, in this paper this simple model is named Model I, in which the forward shock wave begins one second after the supernova explosion and then spreads outward with time. Now, it is known that the reverse shock wave might be generated posterior to the forward shock wave in some supernova models when the mass of the supernova is in the middle range [24].…”

“…Therefore, we used the new density data profile from simulations to calculate the survival probability of electron neutrinos and the conversion probability of non-electron neutrinos, and studied matter effects on neutrino oscillations in three different supernova models. Through these results, we could estimate the number of electron neutrinos (and non-electron neutrinos) which remain after they go through the matter in the supernova [24].…”