Heterotic Line Bundle Standard Models

TL;DR

This paper constructs and analyzes explicit heterotic string models with line bundles that yield realistic supersymmetric standard model spectra, including Higgs multiplets, and examines their phenomenological properties and operator constraints.

Contribution

It provides an explicit construction and spectrum computation of heterotic line bundle standard models, expanding previous work with a detailed database and phenomenological analysis.

Findings

Approximately 400 models with standard model spectra were identified.

Many models forbid dangerous proton decay operators due to extra U(1) symmetries.

The models include up to four anomalous U(1) symmetries constraining the effective theory.

Abstract

In a previous publication, arXiv:1106.4804, we have found 200 models from heterotic Calabi-Yau compactifications with line bundles, which lead to standard models after taking appropriate quotients by a discrete symmetry and introducing Wilson lines. In this paper, we construct the resulting standard models explicitly, compute their spectrum including Higgs multiplets, and analyze some of their basic properties. After removing redundancies we find about 400 downstairs models, each with the precise matter spectrum of the supersymmetric standard model, with one, two or three pairs of Higgs doublets and no exotics of any kind. In addition to the standard model gauge group, up to four Green-Schwarz anomalous U(1) symmetries are present in these models, which constrain the allowed operators in the four-dimensional effective supergravity. The vector bosons associated to these anomalous U(1) symmetries are massive. We explicitly compute the spectrum of allowed operators for each model and present the results, together with the defining data of the models, in a database of standard models accessible at http://www-thphys.physics.ox.ac.uk/projects/CalabiYau/linebundlemodels/index.html. Based on these results we analyze elementary phenomenological properties. For example, for about 200 models all dimension four and five proton decay violating operators are forbidden by the additional U(1) symmetries.