We investigate the scattering of a quantum matter wave soliton on a barrier
in a one dimensional geometry and we show that it can lead to mesoscopic
Schr\"odinger cat states, where the atomic gas is in a coherent superposition
of being in the half-space to the left of the barrier and being in the
half-space to the right of the barrier. We propose an interferometric method to
reveal the coherent nature of this superposition and we discuss in details the
experimental feasibility.Comment: 4 pages, 1 figur