Exactly Solvable Points in the Moduli Space of Heterotic N=2 Strings

TL;DR

This paper explores exactly solvable (0,4) heterotic string vacua within Gepner-like (0,2) models, identifying points of enhanced gauge symmetry on K_3 x T_2 and extending constructions to include nontrivial vector bundles, revealing new branches of the N=2 moduli space.

Contribution

It introduces a complete identification of certain solvable models with enhanced gauge symmetry points and extends the construction to include nontrivial vector bundles in the hidden E_8 gauge group.

Findings

Explicit calculation of enhanced gauge symmetries in examples

Identification of points of enhanced gauge symmetry on K_3 x T_2

Discovery of new branches in the N=2 moduli space

Abstract

We investigate the subset of exactly solvable (0,4) world sheet supersymmetric string vacua contained in a recent class of Gepner-like (0,2) superconformal models. The identification of these models with certain points of enhanced gauge symmetry on K_3 x T_2 can be achieved completely. Furthermore, we extend the construction of in general (0,2) supersymmetric exactly solvable models to the case where also a nontrivial part of the vector bundle is embedded into the hidden E_8 gauge group. For some examples we explicitly calculate the enhanced gauge symmetries and show that they open up the way to interesting branches of the N=2 moduli space. For some of these models candidates of typeII dual descriptions exist.