Neutrino Parameters and Supernova Physics

The uncertain local density profile of the supernova (SN) matter and the choice of model for the SN neutrino spectral parameters would impact the interpretation of the observed neutrino signals. Thus, ambiguity may arise in probing the unknown neutrino intrinsic properties with the SN neutrino fluxes. To account for the local density distribution of matter, which is uncertain yet crucial for the MSW resonant flavor conversion of the SN neutrinos, independent and variable power-law functions are adopted as the respective density profile near each resonance. With this modeling of the local SN matter profile, it is the aim of this project to first investigate how the choice of model for the spectral parameters would impact the prediction of the unknown neutrino properties, and establish observables that are independent of the input spectral parameters. Simultaneous observation of the neutrino fluxes at two terrestrial detectors is emphasized, and the Earth regeneration effect is taken into account. The limitation and capability for probing neutrino intrinsic parameters with SN neutrinos will be investigated. Given the undetermined neutrino intrinsic properties and the existing astrophysical uncertainties, this project is further expanded to study the possible flavor transition due to the newly suggested non-MSW effects. This work is aimed at investigating, under a wider range of the physical conditions, how the non-MSW effect would act as a modification to the MSW effect or would dominate over the MSWeffect. In addition, the possibility of obtaining hints about the unknown SN physics will also be assessed.

Project ID:PA9709-0136
External Project ID:NSC97-2112-M182-001