Speaker
Mr
Ranjan Laha
(The Ohio State University)
Description
Detecting supernova nu_e is essential for testing supernova and neutrino physics, but the yields are small and the backgrounds from other channels large, e.g., ~10^2 and ~10^4 events, respectively, in Super-Kamiokande. We develop a new way to isolate supernova nu_e, using gadolinium-loaded water Cherenkov detectors. The forward-peaked nature of nu_e + e- -> nu_e + e- allows an angular cut that contains the majority of events. Even in a narrow cone, near-isotropic inverse beta events, anti-nu_e + p -> e+ + n, are a large background. With neutron detection by radiative capture on gadolinium, the background events can be individually identified with high efficiency. The remaining backgrounds are smaller and can be measured separately, so they can be statistically subtracted. Super-Kamiokande with gadolinium could measure the total and average energy of supernova nu_e with ~ 20% precision or better each (90% C.L.). Hyper-Kamiokande with gadolinium could improve this by a factor of ~5. This precision will allow powerful tests of supernova neutrino emission, neutrino mixing, and exotic physics. Unless very large liquid argon or liquid scintillator detectors are built, this is the only way to guarantee precise measurements of supernova nu_e.
Primary author
Mr
Ranjan Laha
(The Ohio State University)
Co-author
Prof.
John Beacom
(Ohio State University)