Finite Soft Terms in String Compactifications with Broken Supersymmetry

TL;DR

This paper investigates how supersymmetry breaking soft terms arise in string compactifications, particularly through the Scherk-Schwarz mechanism, and shows they can preserve certain ultraviolet properties of supersymmetric theories.

Contribution

It demonstrates that in heterotic string compactifications with spontaneous supersymmetry breaking, the resulting soft terms can preserve the ultraviolet behavior of N=4 super Yang-Mills theory.

Findings

Soft terms form a 2-parameter class preserving UV properties.

Results align with field theory Scherk-Schwarz mechanism for N=1 supergravity.

Detailed soft term structures differ but share broad features.

Abstract

We consider the role of supersymmetry breaking soft terms that are present in generalized Narain compactifications of heterotic string theory, in which local supersymmetry is spontaneously broken, with gravitino masses being inversely proportional to the radii of compact dimensions. Such compactifications and their variants, are thought to be the natural application of the Scherk-Schwarz mechanism to string theory. We show that in the case where this mechanism leads to spontaneous breaking of N=4, d=4 local supersymmetry, the limit \kappa goes to zero, yields a 2-parameter class of soft terms whose precise form are shown to preserve the ultraviolet properties of N=4 super Yang-Mills theory. This result is in broad agreement with that of the field theory Scherk-Schwarz mechanism, as applied to N=1, d=10 supergravity coupled to super Yang-Mills, although the detailed structure of the soft terms are different in general.