mu and General Gauge Mediation
  We address the mu-problem in the context of General Gauge Mediation (GGM). We classify possible models depending on the way the Higgs fields couple to the supersymmetry breaking hidden-sector. The different types of models have distinct signatures in the MSSM parameters. We find concrete and surprisingly simple examples based on messengers in each class. These examples lead to all the soft masses and a consistent Higgs-sector. 
Zohar Komargodski and Nathan Seiberg