Supernova neutrino detection through neutron emission by nuclei

Abstract

Neutrinos from core collapse supernovae can excite nuclei of some detector materials beyond their neutron emission thresholds. Detection of these neutrons can give valuable information about the supernova explosion mechanism and possibly also throw light on neutrino properties. In this article, we give a brief review of the basic physics of neutrino induced neutron emission and describe the results of some recent calculations of supernova neutrino induced neutrons for some specific target detector materials due to charged current (CC) interactions of the electron flavored neutrinos and antineutrinos as well as due to neutral current (NC) interactions of neutrinos and antineutrinos of all flavors with the detector nuclei. We highlight the fact that a detector material such as lead with a relatively large neutron excess produces neutrons dominantly through the CC interaction of the $\nu_e$s, whereas a material such as iron with small neutron excess produces neutrons dominantly through the combined NC interaction of all the six neutrino and antineutrino species. This raises the interesting possibility of probing the fraction of mu- and tau flavored neutrinos (which interact only through NC interaction) in the supernova neutrino flux by means of simultaneous detection of a supernova in a lead and an iron detector, for example.