A Unified Approach to Supersymmetry Breaking

TL;DR

This paper presents a unified, RG-invariant framework for supersymmetry breaking, clarifying the assumptions behind various models and proposing a natural solution to the negative slepton mass problem.

Contribution

It provides a comprehensive, model-independent approach to SUSY breaking terms, highlighting the role of RG invariance and sequestered models in resolving longstanding issues.

Findings

RG invariant soft SUSY breaking formulae are valid across models

Factorizability assumption is crucial in AMSB formulae

Sequestered models naturally address negative slepton masses

Abstract

General formulae for the soft SUSY breaking terms, valid in any SUGRA context, were derived in the mid-nineties. Since SUSY is not expected to have quantum anomalies, they should be valid in the quantum theory and be RG invariant down to the soft SUSY breaking scale. This observation enables us to give a uniform treatment of all phenomenological models for SUSY breaking and transmission, such as AMSB, GMSB, etc. In particular we find that the much discussed RG invariant formulae for soft SUSY breaking parameters in AMSB, effectively depend on a strong assumption of factorizability of the matter Kaehler metric. We then argue that there is no necessity for having ad hoc constructions such as mAMSB to counteract the negative squared slepton mass problem, since the natural framework that emerges in a sequestered model is one in which gaugino masses are as in AMSB, and the other soft terms are generated by RG running as in gaugino mediation.