Cryptohermitian Picture of Scattering Using Quasilocal Metric Operators

One-dimensional unitary scattering controlled by non-Hermitian (typically, $\mathcal{PT}$-symmetric) quantum Hamiltonians $H\neq H^\dagger$ is considered. Treating these operators via Runge–Kutta approximation, our three-Hilbert-space formulation of quantum theory is reviewed as explaining the unitarity of scattering. Our recent paper on bound states [arXiv:0901.0700] is complemented by the text on scattering. An elementary example illustrates the feasibility of the resulting innovative theoretical recipe. A new family of the so called quasilocal inner products in Hilbert space is found to exist. Constructively, these products are all described in terms of certain non-equivalent short-range metric operators $\Theta\neq I$ represented, in Runge–Kutta approximation, by $(2R-1)$-diagonal matrices.