FUTURE DETECTION OF SUPERNOVA NEUTRINO BURST AND EXPLOSION MECHANISM

Future detection of a supernova neutrino burst by large underground de tectors would give important information for the explosion mechanism o f collapse-driven supernovae. We studied the statistical analysis for the future detection of a nearby supernova by using a numerical supern ova model and realistic Monte Carlo simulations of detection by the Su per-Kamiokande detector. Pile mainly discuss the detectability of the signatures of the delayed explosion mechanism in the time evolution of the (v) over bar(e) luminosity and spectrum. For a supernova at 10 kp c away from the Earth, we find not only that the signature is clearly discernible but also that the deviation of the energy spectrum from th e Fermi-Dirac (FD) distribution can be observed. The deviation from th e FD distribution would, if observed, provide a test for the standard picture of neutrino emission from collapse-driven supernovae. For the D = 50 kpc case, the signature of the delayed explosion is still obser vable, but statistical fluctuation is too large to detect the deviatio n from the FD distribution. We also propose a method for statistical r econstruction of the time evolution of v, luminosity and spectrum from data, by which we can get a smoother time evolution and smaller stati stical errors than by a simple, time-binning analysis. This method is useful especially when the available number of events is relatively sm all, e.g., a supernova in the LMC or SMC. A neutronization burst of v( e)'s produces about five scattering events when D = 10 kpc, and this s ignal is difficult to distinguish from (v) over bar(e)p events.