Title:

The Sudbury Neutrino Observatory: Enhanced neutrino flavor with a pinch of salt.



Art McDonald, 
Queen's University, 
Kingston, Ontario, Canada


Abstract:

The Sudbury Neutrino Observatory (SNO) is a 1,000 tonne heavy
water Cerenkov-based neutrino detector situated 2,000 meters
underground in INCO's Creighton Mine near Sudbury, Ontario,
Canada. Past measurements of solar neutrino fluxes have been
smaller than predicted by solar model calculations (known as the
Solar Neutrino Problem), implying that the calculations are
incomplete or that some of the electron neutrinos produced in
the sun are changing to another flavor en route to earth. SNO
has used the neutrinos from 8B decay in the Sun to observe one
neutrino reaction sensitive only to solar electron neutrinos and
others sensitive to all active neutrino flavors and has found
clear evidence for neutrino flavor change. Results from the
multi-year SNO observation program will be presented, including
recent results with salt in the heavy water to enhance
sensitivity to all active neutrino flavors. The implications of
the present SNO result and other recent neutrino results for
particle physics theory and solar ph `