Chaos in a many-string scattering amplitude

Abstract

String theory provides a compact integral expression for the tree-level scattering amplitude of an arbitrary number of light strings. We focus on amplitudes involving a few tachyons and many photons, with a special choice of polarizations and kinematics. We pick out a particular pole in the amplitude -- one corresponding to successive photon scatterings, which lead to an intermediate state with a highly excited string in a definite state. This provides a physical process which creates a highly excited string. The observed erratic behavior of the amplitude suggests that this may serve as a simple and explicit illustration of chaos in many-particle scattering.