Couplings in Asymmetric Orbifolds and Grand Unified String Models

TL;DR

This paper reviews the computation of scattering amplitudes in asymmetric orbifold string models using the bosonic supercurrent formalism, and reconstructs grand unified models with detailed analysis of their spectra and superpotentials.

Contribution

It introduces a method for calculating scattering amplitudes in asymmetric orbifolds and reconstructs specific grand unified string models with their spectra and superpotentials.

Findings

Reconstruction of 3-family GUT string models.

Identification of quantum numbers of massless states.

Analysis of superpotentials for various GUT models.

Abstract

Using the bosonic supercurrent (or covariant lattice) formalism, we review how to compute scattering amplitudes in asymmetric orbifold string models. This method is particularly useful for calculating scattering of multiple asymmetrically twisted string states, where the twisted states are rewritten as ordinary momentum states. We show how to reconstruct some of the 3-family grand unified string models in this formalism, and identify the quantum numbers of the massless states in their spectra. The discrete symmetries of these models are rather intricate. The superpotentials for the 3-family E_6 model and a closely related SO(10) model are discussed in some detail. The forms of the superpotentials of the two 3-family SU(6) models (with asymptotically-free hidden sectors SU(3) and SU(2) \otimes SU(2)) are also presented.