Disk level S-matrix elements at eikonal Regge limit

TL;DR

This paper analyzes disk level S-matrix elements for massless scalars in string theory, showing that string form factors simplify to one in the eikonal Regge limit when certain Mandelstam variables are zero.

Contribution

It provides an explicit calculation demonstrating the reduction of string form factors to unity at the eikonal Regge limit under specific Mandelstam variable conditions.

Findings

String form factors reduce to one at the eikonal Regge limit.

Simplification occurs when some Mandelstam variables are zero.

Results clarify behavior of S-matrix elements in this limit.

Abstract

We examine the calculation of the color-ordered disk level S-matrix element of massless scalar vertex operators for the special case that some of the Mandelstam variables for which there are no open string channel in the amplitude, are set to zero. By explicit calculation we show that the string form factors in the 2n-point functions reduce to one at the eikonal Regge limit.