Real Unitary Representation of the Many-Channel S Matrix for Complex l and E
Hong-Mo Chan · Journal of Mathematical Physics · 1963
A representation is established for the multichannel S matrix in terms of a matrix function A(l, E) and a scalar function B(l, E), both holomorphic in the domain formed by the product of the whole finite l plane with the finite E plane, cut only along the left-hand dynamical cut. The representation satisfies the known analytic properties of S(l, E), and also all the generalized unitarity conditions of Peierls, LeCouteur, and Newton. The reality condition on S for complex l and E is guaranteed by a simple condition on A and B.