Gribov-Pomeranchuk phenomenon in N/D approach

Abstract

A detailed study of the left-hand function of the Froissart-Gribov representation enables the integral equation for the N function to be reduced to a form studied by Tamarkin. This enables us to show explicitly that the N function develops an essential singularity and causes an infinite number of Regge poles to accumulate at l=-1. When moving cuts are introduced, the integral equation, when again reduced to Tamarkin form, gives conditions on the discontinuity across the cuts for eliminating the essential singularity. The technique in the present form, however, is applicable only to the right-most singularity in the complex angular momentum plane. Extensions of these techniques for π-N scattering (in the s channel) are given as an example of the inclusion of spin effects.