Study determination of parameters that describe the dynamics of a galatic supernova by a future neutrino detector

Author(s)

Regina Celia Medeiros Felix

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Física (IF/SBI)
• Defense date: 2009-05-21

Examining board members

Renata Zukanovich Funchal; Oscar Jose Pinto Eboli; Hiroshi Nunokawa

• Advisor: Renata Zukanovich Funchal

Abstract

The goal of this dissertation is to study the signals that supernova neutrinos could produce in future detectors, through simulations of events observed on Earth by a Cherenkov detector and inverse beta decay reaction. Since a supernova has been the only situation in which neutrinos are able to reach thermal equilibrium, the physics of supernova neutrinos can be source of a new knowledge in physics of elementary particles. We begin this work presenting the most important aspects of neutrino physics as known today, and then studying the role of neutrino in a type II supernova explosion and the oscillation influence in future observations. The simulations were initially performed considering a static potential, defining limits for the main parameters that describe its dynamics. We considered the cases of normal and inverse mass hierarchy and mixing angles within fully adiabatic and non-adiabatic limits. Later we used a supernova dynamic potential to study behavior of transitions probabilities and the profile of the spectrum detected in these previous cases. From this potential we also observed the temporal behavior of the spectrum and how it can be modified with the hierarchy and the mixing angle. We show that, in a future detection, the number of events and hence their variations with supernova parameters, will not suffer interference of the shock wave effect. However, this effect can cause distortions in the energy and time spectrum that could have an important role in determining the mass hierarchy and better constraints for the mixing angle. (AU)