Universal Prohibited Zones in the Coordinate Space of Few-Body Systems

In some special zones of the high-dimensional coordinate space of few-body systems with identical particles, the operation of an element (or a product of elements) of the symmetry groups of the Hamiltonian on a quantum state might be equivalent to the operation of another element. Making use of the matrix representations of the groups, the equivalence of a pair of operations leads to a set of homogeneous linear equations imposed on the wave functions. When the matrix of these equations is non-degenerate, the wave functions will appear as nodal surfaces in these zones. In this case, these zones are prohibited. In this paper, tightly bound 4-boson systems with three types of interaction have been studied analytically and numerically. The existence of the universal prohibited zones has been revealed, and their decisive effect on the structures of the eigenstates is demonstrated. (author)