2003/08/13 by Mathias Th. Keil, Keil, Mathias Th.
Physics and Astronomy · #Astrophysics (astro-ph) #FOS: Physical sciences #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0308228
138pp, Dissertation, Technische Universitaet Muenchen
arxiv created 2003/08/13 · arxiv updated 2009/12/01
We study the flavor-dependent neutrino spectra formation in the core of a supernova (SN) by means of Monte Carlo simulations. A high-statistics neutrino signal from a galactic SN may contain information that severely constrains the parameter space for neutrino oscillations. Therefore, reliable predictions for flavor-dependent fluxes and spectra are urgently needed. In all traditional hydrodynamic simulations the numu,tau and numu,tau-bar interactions commonly included are rather schematic. With our Monte Carlo simulations we find that the most relevant sources for numu,tau and numu,tau-bar are traditionally not included. In comparing our numerical results for all flavors we find the standard hierarchy of mean energies nue < nue-bar < numu,tau, with, however, very similar values for numu,tau and nue-bar. The luminosities of numu,tau and numu,tau-bar can differ by up to a factor of 2 from Lnue-bar and Lnue, the latter two are very similar. The Garching Group obtains similar results from their self-consistent simulation with the full set of interactions. These results are almost orthogonal to the previous standard picture of exactly equal luminosities of all flavors and differences in mean energies of up to a factor of 2. Existing concepts for identifying oscillation effects in a SN neutrino signal need to be revised. We present two methods for detecting the earth-matter effect that are rather independent of predictions from SN simulations.