Partial breaking of supersymmetry, open strings and M-theory

TL;DR

This paper investigates mechanisms of partial and total supersymmetry breaking in string theory models, focusing on orbifold and Scherk-Schwarz compactifications, and explores their dual descriptions in heterotic and M-theory frameworks.

Contribution

It presents explicit models of partial supersymmetry breaking in type I string theory with dual descriptions, highlighting the relationship between compactification scale and mass splittings.

Findings

Mass splittings are proportional to the compactification scale.

Global supersymmetry remains unbroken at tree level for certain D-brane excitations.

Models include four-dimensional chiral compactifications with N=1 supersymmetry breaking.

Abstract

We study total and partial supersymmetry breaking by freely acting orbifolds, or equivalently by Scherk-Schwarz compactifications, in type I string theory. In particular, we describe a four-dimensional chiral compactification with spontaneously broken N=1 supersymmetry, some models with partial $N=4\to N=2$ and $N=4\to N=1$ supersymmetry breaking and their heterotic and M-theory duals. A generic feature of these models is that in the gravitational sector and in the spectrum of D-branes parallel to the breaking coordinate, all mass splittings are proportional to the compactification scale, while global (extended) supersymmetry remains unbroken at tree level for the massless excitations of D-branes transverse to the breaking direction.