Pattern of Texture Zeroes in Quark Mass Matrices With a Divergent   Top-Yukawa Coupling at the GUT Scale
  In a SUSY GUT model responsible for generating symmetric quark mass matrices at the GUT scale (mu = Lamda) we assume that the top-Yukawa coupling, lamda_t, becomes infinite at that scale. As a consequence, the MSSM renormalization group equations for quark Yukawa couplings exhibit hierarchical solutions which lead to a pattern of texture zeroes in quark mass matrices at mu = Lamda similar to one of the solutions of Ramond, Roberts, and Ross. The evolution in energy scale to low energies shows excellent agreement between the measured quantities involving the scale-independent ratios of CKM matrix elements and their predicted values in terms of quark mass ratios. It is noted that the tt-bar condensate model of Bardeen, et al. predicts an infinite lamda_t at mu = Lamda implying, for our model, that at mu = Lamda, both the symmetry of Yukawa matrices and condensate dynamics may have a common origin. 
Bipin R. Desai and D. P. Roy