Neutrino oscillations are studied in the general framework of open quantum
systems by means of extended dynamics that take into account possible
dissipative effects. These new phenomena induce modifications in the neutrino
oscillation pattern that in general can be parametrized by means of six
phenomenological constants. Although very small, stringent bounds on these
parameters are likely to be given by future planned neutrino experiments.Comment: 15 pages, plain-TeX, to appear in JHE