| This dissertation presents a search for antineutrinos in all three phases of data from the Sudbury Neutrino Observatory. This work presents a new method for detecting time correlated coincidences in water detectors. There are two separate searches: an outside search for the inverse beta decay of antineutrinos on protons and an inside search for the inverse beta decay of antineutrinos on deuterons. The inside search found 3 antineutrino candidates in Phase I with an expected background of 3.83+0.71-0.72 events, 28 antineutrino candidates in Phase II with an expected background of 21.25+3.72-3.75 events, 4 antineutrino candidates in Phase III with an expected background of 6.06 ± 1.14 events. The outside search found 4 antineutrino candidates in Phase I with an expected background of 1.21+0.14-0.17 events, 8 antineutrino candidates in Phase II with an expected background of 9.77+1.06-1.34 events, 0 antineutrino candidates in Phase III with an expected background of 0.46 ± 0.29 events.;Including the expected contribution of antineutrinos from nuclear reactors after oscillations, a limit on the solar antineutrino flux is computed to be F8Bn&d1; ≤ 2.5 × 103 cm−2s −1. Taking the flux limit and the measured 8B solar neutrino flux, a limit on the neutrino to antineutrino conversion probability of P(ν → ν) ≤ 5.0 × 10−4. These limits are the best limits from a water detector. |
