Cascading to the MSSM

TL;DR

This paper explores how the MSSM can emerge at the end of a duality cascade in string theory, classifying minimal quiver configurations involving an extra node and analyzing their phenomenological implications.

Contribution

It classifies all minimal quiver realizations of the MSSM at the bottom of a duality cascade with one extra node, extending the geometry to an octahedron and analyzing resulting models.

Findings

MSSM can arise via Higgsing or confinement in the cascade.

The Higgsing scenario yields a left-right symmetric MSSM extension.

The confining scenario requires exactly one Higgs pair for the cascade to proceed.

Abstract

The MSSM can arise as an orientifold of a pyramid-like quiver in the context of intersecting D-branes. Here we consider quiver realizations of the MSSM which can emerge at the bottom of a duality cascade. We classify all possible minimal ways this can be done by allowing only one extra node. It turns out that this requires extending the geometry of the pyramid to an octahedron. The MSSM at the bottom of the cascade arises in one of two possible ways, with the extra node disappearing either via Higgsing or confinement. Remarkably, the quiver of the Higgsing scenario turns out to be nothing but the quiver version of the left-right symmetric extension of the MSSM. In the minimal confining scenario the duality cascade can proceed if and only if there is exactly one up/down Higgs pair. Moreover, the symmetries of the octahedron naturally admit an automorphism of the quiver which solves a version of the mu problem precisely when there are an odd number of generations.