XXth International Conference on Neutrino Physics and Astrophysics
M.Boulay
Event Reconstruction at the Sudbury Neutrino Observatory
The Sudbury Neutrino Observatory is sensitive to solar neutrinos
through three reactions: charged current, neutral current, and elastic
scattering. Each neutrino interaction in SNO leads to either one or
more gamma-rays or an electron in the detector giving rise to
Cherenkov radiation, which is detected by approximately 9600
photomultiplier tubes. The relative time-of-flight, spatial
distribution, and number of these photons detected are used to
reconstruct the position in the detector and momentum of the
events. The backgrounds in SNO (mostly low energy backgrounds from
daughters of 232-Th and 238-U in detector materials) have
characteristic distributions in position and momentum that are well
separated from the neutrino events so that momentum and position cuts
can be applied to reduce those backgrounds to a negligible fraction of
the neutrino signal. The position and momentum distributions of
neutrino events are also used as characteristic distributions for
separating the three signal classes. An overview of event
reconstruction in SNO and associated systematic uncertainties will be
presented, along with the impact on the current solar neutrino flux
measurements from SNO.