A Zip-code for Quarks, Leptons and Higgs Bosons

TL;DR

This paper investigates the spatial localization of matter fields in extra dimensions within string models, revealing a pattern where Higgs and top quark are spread in full space while other families are fixed at specific points, guiding realistic string model building.

Contribution

It introduces a geometric framework for matter field localization in string models, highlighting a universal pattern for quarks, leptons, and Higgs bosons in extra dimensions.

Findings

Higgs bosons and top quark are not localized in extra dimensions.

First two families of quarks and leptons are localized at fixed points.

A general geometric pattern for matter localization is proposed.

Abstract

The location of matter fields and the pattern of gauge symmetry in extra dimensions are crucial ingredients for string model building. We analyze realistic MSSM models from the heterotic Z6 Mini-Landscape and extract those properties that are vital for their success. We find that Higgs bosons and the top quark are not localized in extra dimensions and live in the full D=10 dimensional space-time. The first two families of quarks and leptons, however, live at specific fixed points in extra dimensional space and exhibit a (discrete) family symmetry. Within a newly constructed Z2XZ4 orbifold framework we further elaborate on these location properties and the appearance of discrete symmetries. A similar geometrical picture emerges. This particular Zip-code for quarks, leptons and Higgs bosons seems to be of more general validity and thus a useful guideline for realistic model building in string theory.