  Flavor transitions of Neutrinos with a nonstandard interaction are studied. A
scalar field is conformally coupled to matter and neutrinos. This interaction
alters the neutrino effective mass and its wavefunction leading to a damping
factor, causing deficits in the probability densities and affecting the
oscillation phase. As the matter density determines the scalar field's
behavior, we also have an indirect matter density effect on the flavor
conversion. We explain our results in the context of screening models and study
the deficit in the total flux of electron-neutrinos produced in the Sun through
the decay process and confront our results with observational data.
