Gaugomaly Mediation Revisited

TL;DR

This paper revisits gaugomaly mediation, introducing messenger fields to address the tachyonic slepton problem and gaugino mass splitting, resulting in a more natural and LHC-compatible supersymmetry breaking model.

Contribution

It proposes a hybrid gauge and anomaly mediation model with messenger fields that compress the gaugino spectrum and corrects previous gaugino mass equations.

Findings

Messenger fields solve tachyonic slepton issue.

Gaugino spectrum becomes more compressed.

Model allows lighter gluinos compatible with LHC constraints.

Abstract

Most generic models of hidden sector supersymmetry breaking do not feature singlets, and gauginos obtain masses from anomaly mediated supersymmetry breaking. If one desires a natural model, then the dominant contribution to scalar masses should be of the same order, i.e. also from AMSB. However, pure AMSB models suffer from the tachyonic slepton problem. Moreover, there is a large splitting between the gluino and the wino LSP masses resulting in tight exclusion limits from typical superpartner searches. We introduce messenger fields into this framework to obtain a hybrid theory of gauge and anomaly mediation, solving both problems simultaneously. Specifically, we find any number of vector-like messenger fields (allowed by GUT unification) compress the predicted gaugino spectrum when their masses come from the Giudice-Masiero mechanism. This more compressed spectrum is less constrained by LHC searches and allows for lighter gluinos. In addition to the model, we present gaugino pole mass equations that differ from (and correct) the original literature.