Supersymmetric Standard Model Spectra from RCFT orientifolds

TL;DR

This work conducts a comprehensive search for supersymmetric, tadpole-free four-dimensional vacua derived from RCFT orientifolds of Gepner models, aiming to realize a three-family Standard Model-like chiral spectrum via a four-stack open-string brane setup. By exhaustively exploring symmetric simple current modular invariant partitions and their orientifolds, the authors generate and analyze hundreds of thousands of spectra, computing massless content and gauge couplings while enforcing tadpole and anomaly cancellation. They find about 179,520 distinct SM-like spectra across 44 Gepner models and 333 MIPFs, with varied Higgs content, hidden sectors, and gauge-coupling patterns; a significant fraction show intriguing near-unification behavior, but there is no universal unification at the string scale. The results map a rich landscape of open-string realizations of the SM at rational points, highlighting the prevalence of hidden sectors and nontrivial U(1) structure, and setting the stage for further work on Yukawas, moduli effects, and alternative RCFT frameworks.

Abstract

We present supersymmetric, tadpole-free d=4,N=1 orientifold vacua with a three family chiral fermion spectrum that is identical to that of the Standard Model. Starting with all simple current orientifolds of all Gepner models we perform a systematic search for such spectra. We consider several variations of the standard four-stack intersection brane realization of the standard model, with all quarks and leptons realized as bifundamentals and perturbatively exact baryon and lepton number symmetries, and with a U(1)_Y vector boson that does not acquire a mass from Green-Schwarz terms. The number of supersymmetric Higgs pairs H_1 + H_2 is left free. In order to cancel all tadpoles, we allow a "hidden" gauge group, which must bechirally decoupled from the standard model. We also allow for non-chiral mirror-pairs of quarks and leptons, non-chiral exotics and (possibly chiral) hidden, standard model singlet matter, as well as a massless B-L vector boson. All of these less desirable features are absent in some cases, although not simultaneously. In particular, we found cases with massless Chan-Paton gauge bosons generating nothing more than SU(3) x SU(2) x U(1). We obtain almost 180000 rationally distinct solutions (not counting hidden sector degrees of freedom), and present distributions of various quantities. We analyse the tree level gauge couplings, and find a large range of values, remarkably centered around the unification point.

Figures (7)

• Figure 1: Mirrors
• Figure 2: Non-Chiral Leptoquarks
• Figure 3: Non-Chiral tensor representations
• Figure 4: Number of Higgs
• Figure 5: Hidden sector of all solutions