Neutrinos as astrophysical probes

Abstract

The aim of these notes is to provide a brief review of the topic of neutrino astronomy and in particular of neutrinos from core collapse supernovae. They are addressed to a curious reader, beginning to work in a multidisciplinary area that involves experimental neutrino physics, astrophysics, nuclear physics and particle physics phenomenology. After an introduction to the methods and goals of neutrinos astronomy, we focus on core collapse supernovae, as (one of) the most promising astrophysical source of neutrinos. The first part is organized almost as a tale, the last part is a bit more technical. We discuss the impact of flavor oscillations on the supernova neutrino signal (=the change of perspective due to recent achievements) and consider one specific example of signal in detail. This shows that effects of oscillations are important, but astrophysical uncertainties should be thought as an essential systematics for a correct interpretation of future experimental data. Three appendices corroborate the text with further details and some basics on flavor oscillations; but no attempt of a complete bibliographical survey is done (in practice, we selected a few references that we believe are useful for a `modern' introduction to the subject. We suggest the use of public databases for papers as SPIRES or NASA/ESO or for experiments as SPIRES or PaNAGIC to get a more complete information).Comment: 18 pages, 3 figures. To appear in "Surveys in High energy Physics

Neutrinos from Supernovas and Supernova Remnants

“…10, inserting respectively Z pm + for ψ ν e , and Z pm − for ψν e and the appropriated moments. The numerical values of k ν = (ψ (1) ν + ψ (2) ν )/ψ γ for several values of Γ, obtained using the spectrum-weighted momenta from figure 5.5 by [17], are reported in table 1 by [4]. 3 In our calculation, we omitted the contribution of ν's produced in other decay modes of π and K, as well as in K 0 's decay chains, and so we introduce and error at several % level.…”

Study of the effect of neutrino oscillations on the supernova neutrino signal in the LVD detector

“…[31] ). Thus, the so-called "energy equipartition" has to be intended as "within a factor of two" [30].…”

“…in [31]. The expected number of events in the various LVD detection channels and the mean energy of the detectedν e p events are shown in Our approach will be the following: we change the value of one parameter from the value listed in table 2 to the extreme lower and upper values, leaving the other astrophysical parameters unchanged and we show the fractional modification in the number of events and in the mean energy of the detected ν e inν e p interactions.…”

“…In this particular case the P 1e probabilities are exactly described by [31]: A simplified Cobalt nucleus level structure is shown in figure B.1, where the 0 + AR is 3.59 MeV over the ground state and the GTR take the other energy levels. Therefore, in our simulation, we take into account 5 possible channels [49]:…”

Supernova neutrino detection

“…The amount of the total binding energy E b taken by each flavor is L α = f να E b , with f νe = 17 − 22%, fν e = 17 − 28%, f νx = 16 − 12%. Thus, the so-called "energy equipartition" has to be intended as "within a factor of two" or so [4].…”