The Vacuum Moduli Space of the Minimal Supersymmetric Standard Model

TL;DR

This paper investigates the complex geometric structure of the vacuum moduli space in the minimal supersymmetric Standard Model (MSSM), identifying its components and their properties with and without neutrinos.

Contribution

It provides a detailed geometric analysis of the full vacuum moduli space of the MSSM, including its irreducible components and their images under a symplectic quotient map, extending previous electroweak sector studies.

Findings

The vacuum moduli space has three irreducible components.

Each component's image under the symplectic quotient map is a rational variety.

The structure simplifies when restricting to the electroweak sector.

Abstract

A starting point in the study of the minimal supersymmetric Standard Model (MSSM) is the vacuum moduli space, which is a highly complicated algebraic variety: it is the image of an affine variety $X \subset \mathbb{C}^{49}$ under a symplectic quotient map $\phi$ to $\mathbb{C}^{973}$. Previous work computed the vacuum moduli space of the electroweak sector; geometrically this corresponds to studying a restriction of $\phi$: $\mathbb{C}^{13} \stackrel{\phi^{\texttt{res}}}{\longrightarrow} \mathbb{C}^{22}$. We analyze the geometry of the full vacuum moduli space for superpotentials $W_{\rm minimal}$ (without neutrinos) and $W_{\rm MSSM}$ (with neutrinos) in $\mathbb{C}^{973}$. In both cases, we prove that $X$ consists of three irreducible components $X_1$, $X_2$, and $X_3$, and determine the images $M_i$ of the $X_i$ under $\phi$. For $W_{\rm minimal}$ we show they have, respectively, dimensions $1$, $15$, and $29$, and prove that each of the $M_i$ is a rational variety, while for $W_{\rm MSSM}$ we show that $M_3$ is the only component. Restricting the $M_i$ to the electroweak sector, we recover known results. We describe the components of the vacuum moduli space geometrically in terms of incidence varieties to a product of Segre varieties.