Learning more about what can be concluded from the observation of neutrinos from a galactic supernova

TL;DR

This study explores how well a megaton Water-Cherenkov detector can determine supernova neutrino flux parameters and the mixing angle θ13 from galactic supernova observations, highlighting the potential and limitations of current detection methods.

Contribution

It provides a comprehensive analysis of parameter constraints from supernova neutrino observations using multiple detection channels and includes the impact of the mixing angle θ13.

Findings

θ13 can be well constrained without additional assumptions

Most supernova flux parameters are difficult to determine independently

Detection channels alone may not fully constrain all parameters

Abstract

We investigate what one can hope to learn about the parameters that describe the neutrino fluxes emitted by the explosion of a galactic supernova using the observations of a megaton-size Water-Cherenkov detector. We calculate the allowed regions that can be obtained by fitting these parameters to a simulated observation of events by such a detector. All four available detection channels (inverse beta decay, charge and neutral current on oxygen and elastic scattering on electrons) are included in the fit and we use a ten dimensional parameters space. Nine parameters describe the initial neutrino fluxes and are referred to as the supernova parameters. Furthermore, we include the dependence on the Chooz mixing angle $\theta_{13}$, which controls the matter effects that the neutrino undergoes in the outer-parts of the supernova. If we do not make any extra assumption on these parameters, we show that one can hope to determine $\theta_{13}$ quite well whereas, except for the parameters describing the $\bar\nu_e$ flux, most of the supernova parameters are rather difficult to constrain, even if the four detection channels could be completely separated.