ANALYTIC CONTINUATION OF THE SCATTERING MATRIX IN THE MULTICHANNEL PROBLEM AND THE LAX-PHILLIPS APPROACH

Explicit representations for the analytic continuation of the t and s matrices on all the sheets of the Riemann surface in the multichannel problem are obtained in terms of the t and s matrices on the physical sheet. The Lax-Phillips approach is used to give an operator interpretation of resonances situated on the unphysical sheet connected with the physical one by crossing through the interval between the lower thresholds.