Geometry of Particle Physics

Abstract

We explain how to construct a large class of new quiver gauge theories from branes at singularities by orientifolding and Higgsing old examples. The new models include the MSSM, decoupled from gravity, as well as some classic models of dynamical SUSY breaking. We also discuss topological criteria for unification.

Figures (19)

• Figure 1: Caricature of a global D-brane model. If the size of the $T^2$ goes to infinity, as typically happens in the $M_{\rm pl,4} \to \infty$ limit, the volumes of the branes and the distance between their intersections goes to infinity as well, shutting of the Standard Model couplings.
• Figure 2: The radial direction away from the fractional brane is interpreted as an energy scale. After Higgsing the Del Pezzo quiver theory, a sufficiently small neighbourhood of the singularity describes the MSSM.
• Figure 3: (A): An MSSM quiver, with an additional massless $U(1)_{B-L}$. (B): Model I, a left-right unified model which can be Higgsed to the MSSM.
• Figure 4: Model II: a quiver consisting of the MSSM, $U(1)_{B-L}$ plus a massive $U(1)_{B+L}$. The $U(1)_{B-L}$ can be coupled to a Stückelberg field.
• Figure 5: The Standard model plus $U(1)_{B}$. Note we still need R-parity to forbid undesirable couplings.