Realistic calculations of nuclear disappearance lifetimes induced by n(n)over-bar oscillations

Realistic calculations of nuclear disappearance lifetimes induced by nn oscillations are reported for oxygen and iron, using n nuclear potentials derived from a recent comprehensive analysis of p atomic X-ray and radiochemical data. A lower limit tau(n (n) over bar) > 3.3 x 10(8) s on the nn oscillation time is derived from the Super-Kamiokande I new lower limit T-d(O) > 1.77 x 10(32) yr on the neutron lifetime in oxygen. Antineutron scattering lengths in carbon and nickel, needed in trap experiments using ultracold neutrons, are calculated from updated N optical potentials at threshold, with results shown to be largely model independent.