A Mini-Landscape of Exact MSSM Spectra in Heterotic Orbifolds

TL;DR

The paper addresses the problem of identifying heterotic string vacua that realize the exact MSSM spectrum within a $Z_{6}$-II orbifold framework. It employs a local-GUTs approach with SO(10) or E6 structures, two discrete Wilson lines, and a criterion enforcing three SM generations plus vector-like exotics that can be decoupled by singlet VEVs while preserving SUSY and standard hypercharge normalization. The authors report that roughly 1% of about $3\times 10^{4}$ inequivalent models satisfy the MSSM-like content, yielding on the order of $O(100)$ viable candidates with a hidden sector, and they present an explicit example with a renormalizable top Yukawa, maximal-rank exotic mass matrices, and a B-L-based matter parity to suppress proton decay. This work demonstrates that a relatively fertile patch of the string landscape exists for realistic MSSM realizations and motivates further phenomenological study and expansion to other regions of the landscape.

Abstract

We explore a ``fertile patch'' of the heterotic landscape based on a Z_6-II orbifold with SO(10) and E_6 local GUT structures. We search for models allowing for the exact MSSM spectrum. Our result is that of order 100 out of a total 3\times 10^4 inequivalent models satisfy this requirement.