Precision String Phenomenology

TL;DR

This paper numerically computes Yukawa couplings in heterotic string models with Calabi-Yau compactifications, revealing natural hierarchies that are crucial for realistic particle physics models.

Contribution

It provides the first detailed numerical analysis of physical Yukawa couplings in heterotic string models, highlighting the emergence of hierarchies.

Findings

Existence of natural hierarchies in Yukawa couplings

Numerical methods applied to heterotic models

Insights into particle physics from string compactifications

Abstract

Calabi--Yau compactifications of the $E_8\times E_8$ heterotic string provide a promising route to recovering the four-dimensional particle physics described by the Standard Model. While the topology of the Calabi--Yau space determines the overall matter content in the low-energy effective field theory, further details of the compactification geometry are needed to calculate the normalized physical couplings and masses of elementary particles. In this work, we present numerical computations of physical Yukawa couplings in a number of heterotic models in the standard embedding and demonstrate the existence of natural hierarchies, a coveted feature in string model building.