Motivation for a Neutron-Antineutron Oscillation Search in the Sudbury Neutrino Observatory

Grand unified theories generally predict the existence of baryon number nonconservation, manifesting itself in processes like proton decay and neutron-antineutron (n-n) oscillation. Experimental nonobservation of proton decay has led to the development of several experimental searches for n-n oscillations. To date, this phenomenon has never been detected, setting an experimental lower limit on the n-n oscillation time (τnn) as τnn > 1.3× 10 s at 90 % C.L. (according to Soudan 2). The Sudbury Neutrino Observatory (SNO), a heavy water Čerenkov detector, can be used to increase the lower limit on τnn if an experimental search is developed. It can be seen that such an experiment in SNO could result in τnn > 2× 10 s at 90 % C.L., a sizable improvement over the current limit. As more data becomes available from SNO, this limit can be increased.