Limits on tan beta in SU(5) GUTs with Gauge-Mediated Supersymmetry   Breaking
  By considering the constraints from nucleon decay we obtain upper limits on tan beta in generalized supersymmetric SU(5) grand unified theories with gauge-mediated supersymmetry breaking. We find that the predicted values of tan beta in these models are mostly inconsistent with the constraints from nucleon decay. 
H. Hamidian, K. Huitu, K. Puolamaki, D.-X. Zhang