Advances in Old-Fashioned Heterotic String Model Building

TL;DR

This paper reviews recent progress in perturbative heterotic string model building, focusing on extra U(1) symmetries, local discrete symmetries, and their implications for proton decay and model classification.

Contribution

It summarizes recent developments in heterotic string models, highlighting new insights into U(1) symmetries, discrete symmetries, and their phenomenological implications.

Findings

U(1) symmetries help limit proton decay

Classification of models with anomalous U(1) has advanced

Kinetic mixing complicates observable-hidden sector interactions

Abstract

I review findings of various research groups regarding perturbative heterotic string model building in the last 12 months. Attention is given to recent studies of extra U(1)'s and local discrete symmetries (LDS's) in generic string models. Issues covered include the role of U(1)'s and LDS's in limiting proton decay, developments in classification of models containing anomalous U(1), and possible complications resulting from kinetic mixing between observable and hidden sector U(1)'s. Additionally, recent string-derived and string-inspired models are briefly reviewed. Talk Presented at SUSY '97.