Standard Models and Split Supersymmetry from Intersecting Brane Orbifolds

TL;DR

This paper constructs intersecting D6-brane models in string theory that replicate the Standard Model and MSSM spectra, explore split supersymmetry scenarios, and analyze bounds on the string scale based on exotic matter masses.

Contribution

It presents the first N=0 stringy quiver models with MSSM matter, fixed moduli, and explores split supersymmetry within intersecting brane frameworks.

Findings

MSSM-like models with minimal exotics and fixed moduli.

Lower bounds on string scale from exotic triplet masses.

Support for split supersymmetry scenarios in string theory.

Abstract

We construct four dimensional three generation non-supersymmetric $SU(3)_c \times SU(2)_L \times U(1)_Y$ intersecting D6-brane models with $\nu_R$\rq{s}. At three stacks we find exactly the MSSM chiral fermion matter spectrum. At 4-, 5-stacks we find models with the massless fermion spectrum of the N=1 Standard Model and massive exotic non-chiral matter; these models flow also to only the SM. At 8-stacks we find MSSM-like models, with minimal massless exotics, made from two different N=1 sectors. Exotic triplet masses put a lower bound on the string scale of $2.79/2.89 \times 10^6$ GeV for a Higgs 124/126 GeV. It\rq{}s the first appearance of N=0 stringy quivers with the MSSM and matter in antisymmetric representations and perturbatively missing Yukawa couplings. The present models are based on orientifolds of ${\bf T^6/(Z_3 \times Z_3)}$ compactifications of IIA theory based on the torus lattice AAA; all complex moduli are fixed by the orbifold symmetry. We also present the spectrum rules + GS anomaly cancellation for the ABB lattice. Moreover, we point out the relevance of intersecting/and present D6-brane constructions on ideas related to existence of split supersymmetry in nature. In this context we present non-susy models with only the SM-matter and also MSSM-matter dominated models, with massive gauginos and light higgsinos, that achieve the correct supersymmetric GUT value for the Weinberg angle $sin^2 \theta = \frac{3}{8}$ at a string scale $5 \cdot 10^{13} \ GeV < M_{S} < 1.4 \cdot 10^{17}$ GeV. It appears that if only the SM survives at low energy the unification scale is preserved at $5.03 \times 10^{13}$ GeV when n$_H$ =1, 3, 6. These models support the existence of split supersymmetry scenario in string theory.