MSHSM – Minimal Standard Heterotic String Models

Abstract

An overview of old and new results in studies of the quasi-realistic free fermionic models is presented, which include the recent discovery of exophobic string vacua and reproduction of the Higgs-matter splitting mechanism in a corresponding orbifold construction.Comment: 4 pages. To appear in the proceedings of the Corfu Summer Institute 200

R-charge conservation and more in factorizable and non-factorizable orbifolds

“…For the prime orbifolds there is a one-to-one correspondence between the twist fields and fixed points, but for non-prime orbifolds it is helpful to construct them as [38,39]: 8) with σ (k,θ r f ) being viewed as auxiliary twist fields. Note that, as far as quantum properties go, the auxiliary twist fields σ (k,θ r f ) with various θ r f are indistinguishable.…”

“…In particular we now have hundreds of explicit models whose low energy matter spectra are potentially realistic -containing the standard model particles and no chiral exotics -in several classes of string constructions; heterotic smooth Calabi-Yau compactifications [1], heterotic orbifold compactifications [2], Gepner models [3], free fermionic constructions [4], D-brane models [5], F-theory [6] (see [7][8][9][10] for some recent reviews). It is now essential to go beyond the particle content, and consider the low energy effective field theory that describes their phenomenology.…”