On Reggeized Absorption in the Presence of a Grey Disc Pomeron of Ball and Zachariasen Type

Abstract

Theoretical consequences of absorptive correction to the Reggeonic amplitude are studied under the assumption of a grey disc Pomeron of Ball and Zachariasen type. By the use of the procedure of the double-partial-wave amplitude recently proposed by Bronzan and Sugar, three typical conclusions are obtained with regard to the structure of l-plane singularities associated with Reggeized absorption. First, the Reggeonic amplitude with absorption has three different types of moving branch cuts in the l-plane, i.e., a logarithmic branch cut, two pairs of colliding branch cuts of logarithmic type and a pair of colliding branch cuts of square-root type. Secondly, the input Regge pole of linear trajectory-function remains unmodified on the physical sheet of l-plane. Thirdly, there is an energy-independent domain, |t|≪ constant, of momentum transfers in which the asymptotic behaviour of the full Reggeonic amplitude is controlled by the input Regge pole. These conclusions bring out in striking contrast the difference between grey and black disc Pomerons.