The likelihood for supernova neutrino analyses

We derive the event-by-event likelihood that allows to extract the complete information contained in the energy, time and direction of supernova neutrinos, and specify it in the case of SN1987A data. We resolve discrepancies in the previous literature, numerically relevant already in the concrete case of SN1987A data.Comment: 7 pages, 2 figures. Accepted for publication in PR

Double pulses and cascades above 2 PeV in IceCube

IceCube collaboration has seen an unexpected population of high energy neutrinos compatible with an astrophysical origin. We consider two categories of events that can help to diagnose cosmic neutrinos: double pulse, that may allow us to clearly discriminate the cosmic component of tau neutrinos; cascades with deposited energy above 2 PeV, including events produced by electron antineutrinos at the Glashow resonance, that can be used to investigate the neutrino production mechanisms. We show that one half of the double pulse signal is due to the neutrinos spectral region already probed by IceCube. By normalizing to HESE data, we find that 10 more years are required to obtain 90% probability to observe a double pulse. The cascades above 2 PeV provide us a sensitive probe of the high energy tail of the neutrino spectrum and are potentially observable, but even in this case, the dependence on type of the source is mild. In fact we find that pp or p{\gamma} mechanisms give a difference in the number of cascades above 2 PeV of about 25 % that can be discriminated at 2{\sigma} in about 50 years of data taking.Comment: 20 pages, 7 figures, accepted for publication in EPJ

Using supernova neutrinos to monitor the collapse, to search for gravity waves and to probe neutrino masses

We discuss the importance of observing supernova neutrinos. By analyzing the SN1987A observations of Kamiokande-II, IMB and Baksan, we show that they provide a 2.5{\sigma} support to the standard scenario for the explosion. We discuss in this context the use of neutrinos as trigger for the search of the gravity wave impulsive emission. We derive a bound on the neutrino mass using the SN1987A data and argue, using simulated data, that a future galactic supernova could probe the sub-eV region.Comment: 8 pages, 1 figure. Proceeding for the Galileo-Xu Guangqi meeting: The Sun, the Stars, the Universe and General Relativity; October 26-30, 2009, Shanghai (China). Accepted for publication at International Journal of Modern Physics