A Missing Partner Model With 24-plet Breaking SU(5)
  We give a missing partner model using 24-plet instead of 75-plet to break the SU(5) symmetry. Fermion masses and mixing are generated through the Georgi-Jarlskog mechanism. The model is constructed at renormalizable level at very high energy. The perturbative region is extended for the unification gauge coupling. Constrains by proton decay is also satisfied. 
Da-Xin Zhang and Jun-hui Zheng
hep-ph