Supersymmetry Breakdown at a Hidden Wall

TL;DR

This work analyzes supersymmetry breaking in the heterotic M-theory framework, focusing on gaugino condensation on a hidden wall and its transmission to the observable sector via gravity. The authors show that soft terms in the 4D effective theory are of order the gravitino mass $m_{3/2}$, with a marked difference between weakly and strongly coupled regimes: in the weakly coupled case, gaugino masses are typically suppressed relative to scalars, while in the strongly coupled regime they are comparable to scalar masses due to the nontrivial dependence of the gauge-kinetic function on the moduli $S$ and $T$. The analysis highlights the role of the corrected gauge kinetic functions $f_6={\cal S}+\alpha{\cal T}$ and $f_8={\cal S}-\alpha{\cal T}$, the (near) critical radius of the 11th dimension, and the resulting phenomenological implications, including potential axion scenarios and dark matter considerations. Overall, the paper argues that heterotic M-theory provides a coherent, testable path from gaugino condensation to TeV-scale soft SUSY breaking, with distinctive predictions for gaugino masses and unification yet to be fully explored in explicit models.

Abstract

We consider hidden sector supersymmetry breakdown in the strongly coupled heterotic $E_8\times E_8$ theory of Hořava and Witten. Using effective field theory methods in four dimensions, we can show that gravitational interactions induce soft breaking terms in the observable sector that are of order of the gravitiono mass. We apply these methods to the mechanism of gaugino condensation at the hidden wall. Although the situation is very similar to the weakly coupled case, there is a decisive difference concerning the observable sector gaugino mass; with desirable phenomenological as well as cosmological consequences.