Exploring the sub-eV neutrino mass range with supernova neutrinos

A new method to study the effects of neutrino masses on a supernova neutrinosignal is proposed. The method relies exclusively on the analysis of the fullstatistics of neutrino events, it is independent of astrophysical assumptions,and does not require the observation of any additional phenomenon to tracepossible delays in the neutrino arrival times. The sensitivity of the method tothe sub-eV neutrino mass range, defined as the capability of disentangling at95% c.l. the case $m_\nu=1$eV from $m_\nu=0$, is tested by analyzing a set ofsynthetic neutrino samples modeled according to the signal that could bedetected at SuperKamiokande. For a supernova at the Galactic center success isachieved in more than 50% of the cases. It is argued that a future Galacticsupernova yielding several thousands of inverse $\beta$ decays might provideenough information to explore a neutrino mass range somewhat below 1 eV.Comment: Included analysis with numerical neutrino energy spectrum and oscillations effects. 7 pages, 6 figure