Who Needs Clusters in the Dual Bootstrap?

Abstract

We review recent progress in the planar Dual Bootstrap program. The delicate interplay between the analytic properties of Reggeon amplitudes and the proper counting of the contribution of all intermediate states to the planar unitarity summation is exposed. This interplay guarantees a pure Regge-pole-type solution to the bootstrap program. The naive expectation that planar unitarity will enforce the existence of Regge cuts does not materialize at the planar level. The notion of clusters as narrow resonances is not used. Rather, they are viewed as bins of arbitrary size into which all available phase space in the intermediate state is divided.