Production cross section of rotating string

TL;DR

This paper derives the production cross section of a rotating string in bosonic string theory, showing it depends on the angular momentum and matches known string form factors at high energies.

Contribution

It provides a new analytical expression for the rotating string production cross section using Bessel functions and partial wave expansion, linking it to string form factors.

Findings

Cross sections expressed via modified Bessel functions.

Asymptotic behavior aligns with known string form factors.

High energy regime results are consistent with theoretical expectations.

Abstract

We calculate production cross sections of a single rotating string from a collision of two light states in bosonic string theory. We find that the cross sections are written in terms of the modified Bessel function of the first kind with the degree given by the angular momentum in the high energy regime. We also obtain a similar formula from the partial wave expansion of four point amplitudes. Asymptotic behavior of the cross sections is consistent with a well known form factor of a string.