What is the purpose of the Euler-Beta function in superstring theory?

Question

I would prefer an answer from a post-graduate, Masters or PhD. And keep it technical, (aka no consideration for the lay-person)

Answer 1

It was used in evaluating the crossing symmetric scattering amplitudes for scattering of four scalar particles. veneziano's original formula for the scattering amplitudes was a sum of three terms, each of which could be written in terms of Beta functions. See a technical history in the pdf file below. Formula 2 on page 3 is essentially the Beta function.

Answer 2

It is an attempt to explain the dynamics of strong nuclear force. That is about it.