The Study Of Supernova Majorana Neutrinos Collective Oscillations

Neutrino oscillation,as the phenomenon that beyond the standard model of particle physics,has been studied widely.The difference between mass eigenstate and flavor eigenstate can trigger various oscillation phenomenon.Neutrino oscillation in different medium may leads to totally different result because of matter effect and self-interaction effect.The extreme physical condition of supernovae makes them to be an idea laboratory to study astronomy physics and particle physics.Observing the neutrino and light signal can help studying the evolution of early universe and the properties of fundamental particles.During supernova explosion,more than 99% energy of supernova changes into neutrinos,so that self-interaction will play the main role when neutrinos travel through the supernova,which would,in turn,leads to a series of unique phenomena on supernovae neutrinos.In this paper,we derive the supernova neutrino flavor evolution numerically in the presence of the non-trivial neutrino magnetic moment and strong magnetic field,using the two-flavor and single-angle approximation.The novel properties of collective neutrino oscillations are studied in three steps.At first we study the oscillation triggered by neutrinos magnetic moments when mass eigenstate and flavor states are consistent.Then we study the oscillation triggered by neutrino vacuum mixing and neutrinos magnetic moments when mass eigenstate and flavor states are different.Finally we also discuss how the neutrino magnetic moment affects the observable supernova neutrino energy spectra.We believe that these results will contribute towards a better understanding of the neutrino mixing,as well as supernova astrophysics and cosmology.If the future neutrino experiments can observe enough supernovae neutrinos events,combining the research in this paper may solve mass ordering problem and magnetic moments problem of neutrinos.