Dynamical Schr\"odinger cats can be formed when a one-dimensional attractive
Bose-gas cloud is scattered off a potential barrier. Once formed, these objects
are stable in time. The phenomenon and its mechanism -- transformation of
kinetic energy to internal energy of the scattered atomic cloud -- are obtained
by solving the time-dependent many-boson Schr\"odinger equation. Implications
are discussed.Comment: 11 pages, 3 figure