Chiral family classification of fermionic Z2xZ2 heterotic orbifold models

TL;DR

This paper classifies over ten billion string vacua from free fermionic constructions related to Z2XZ2 orbifolds, revealing a bell-shaped distribution peaking at zero net families and identifying symmetries in the model distributions.

Contribution

It provides a comprehensive classification of a vast landscape of string vacua using Monte Carlo methods, uncovering distribution patterns and symmetries not previously detailed.

Findings

Distribution peaks at zero net chiral families.

Approximately 15% of models have three net chiral families.

Distribution exhibits symmetry under exchange of certain representations.

Abstract

Free fermionic construction of four dimensional string vacua, are related to the Z2XZ2 orbifolds at special points in the moduli space, and yielded the most realistic three family string models to date. Using free fermionic construction techniques we are able to classify more than 10^10 string vacua by the net family and anti-family number. Using a montecarlo technique we find that a bell shaped distribution that peaks at vanishing net number of chiral families. We also observe that ~15% of the models have three net chiral families. We find that in addition to mirror symmetry that the distribution exhibits a symmetry under the exchange of (spinor plus anti-spinor) representations with vectorial representations.