Gravity mediated supersymmetry breaking in six dimensions

TL;DR

This paper develops a six-dimensional supergravity model with branes, derives the four-dimensional effective theory, and identifies conditions for positive scalar masses, advancing understanding of gravity-mediated supersymmetry breaking.

Contribution

It constructs a locally supersymmetric bulk-brane action in six dimensions with fixed, flavor-universal couplings and derives the 4D effective supergravity, including a scenario for positive scalar masses.

Findings

Couplings of bulk moduli to branes are flavor universal.

The 4D effective Kahler potential is not sequestered, allowing tree-level gravity mediation.

A scenario for moduli stabilization with positive soft scalar masses is identified.

Abstract

We study gravity mediated supersymmetry breaking in four-dimensional effective theories derived from six-dimensional brane-world supergravity. Using the Noether method we construct a locally supersymmetric action for a bulk-brane system consisting of the minimal six-dimensional supergravity coupled to vector and chiral multiplets located at four-dimensional branes. Couplings of the bulk moduli to the brane are uniquely fixed, in particular, they are flavour universal. We compactify this system on T_2/Z_2 and derive the four-dimensional effective supergravity. The tree-level effective Kahler potential is not of the sequestered form, therefore gravity mediation may occur at tree-level. We identify one scenario of moduli stabilization in which the soft scalar masses squared are postive.