Four-dimensional M-theory and supersymmetry breaking

TL;DR

This paper explores M-theory compactifications from 11 to 4 dimensions, analyzing supersymmetry breaking mechanisms, superpotential generation, and phenomenological implications like string unification and decompactification.

Contribution

It introduces a universal superpotential for the axion-dilaton field arising from 5D compactification, linking supersymmetry breaking to the fifth dimension radius.

Findings

A vacuum with zero cosmological constant and <S>=1 is achieved.

Gravitino mass scales as R_5^{-2}/M_{Pl}.

Implications for string unification and decompactification are discussed.

Abstract

We investigate compactifications of M-theory from $11\to 5\to 4$ dimensions and discuss geometrical properties of 4-d moduli fields related to the structure of 5-d theory. We study supersymmetry breaking by compactification of the fifth dimension and find that an universal superpotential is generated for the axion-dilaton superfield $S$. The resulting theory has a vacuum with $<S>=1$, zero cosmological constant and a gravitino mass depending on the fifth radius as $m_{3/2} \sim R_5^{-2}/M_{Pl}$. We discuss phenomenological aspects of this scenario, mainly the string unification and the decompactification problem.