Searching for hep Neutrinos using the Sudbury Neutrino Observatory

Abstract

The Sudbury Neutrino Observatory has recently finished its third and final phase, and has accumulated over 1082 days of neutrino data, spanning the energy range from approximately 5-20 MeV. Almost all the observed neutrinos are due to the 8B reaction in the Sun. The so-called hep process (3He + p -> 4He + e + nu_e) also occurs in the Sun, but has not yet been observed. hep neutrino energy endpoint extends above the 8B spectrum. This paper describes the three phase analysis that will ultimately be the most sensitive to this reaction.