Intersecting Brane Worlds at One Loop

TL;DR

This paper develops techniques for calculating one-loop diagrams on intersecting branes, demonstrating the finiteness of propagators and the softening of Yukawa coupling running, with methods applicable to heterotic models.

Contribution

It introduces exact calculations of one-loop propagators and general N-point functions on intersecting branes, ensuring finiteness via RR tadpole cancellation and extending methods to heterotic models.

Findings

Exact one-loop propagator for intersection states calculated.

Finiteness of propagator guaranteed by RR tadpole cancellation.

Softening of Yukawa coupling running at the string scale demonstrated.

Abstract

We develop techniques for one-loop diagrams on intersecting branes. The one-loop propagator of chiral intersection states on D6 branes is calculated exactly and its finiteness is shown to be guaranteed by RR tadpole cancellation. The result is used to demonstrate the expected softening of power law running of Yukawa couplings at the string scale. We also develop methods to calculate arbitrary N-point functions at one-loop, including those without gauge bosons in the loop. These techniques are also applicable to heterotic orbifold models.