Precision Test of Quark Mass Textures: A Model Independent Approach
  Using a Monte Carlo method, we have directly extracted from the available measurements, the hierarchies among the different elements of the quark mass matrices. To do that, we have first introduced a model independent parameterization for two generic class of models: those based on Abelian symmetries and those inspired by a U(2) horizontal symmetry. So, matrix entries are proportional to some epsilon^t, with epsilon<<1 and the t's are different free exponents that we determine from the data through a statistically well defined procedure. We have found that the experimental data poorly constrain the Abelian scenarios. Instead, in non Abelian scenarios, these t-exponents are strongly constrained by the present data. We have found that contrary to a naive U(2) horizontal symmetry expectation, quark mass matrices turn out to be not symmetric. Two solutions emerge: one with M_{32}^{{down}}>> M_{23}^{down}} and M_{21}^{up}>> M_{12}^{{up}}; and a second one with slight asymmetries only in the light quark sector, namely M_{21}^{up} < M_{12}^{up} and M_{21}^{down}>M_{12}^{down}. 
F. Caravaglios, P. Roudeau, A. Stocchi