Quark masses and mixings in E6 x S3 : a montecarlo approach

Abstract

Recently in arXiv:hep-ph/0510321 has been proposed a GUT model for fermion masses and mixings with spontaneously broken S3 discrete flavor symmetry, where S_3 is the permutation group of three objects. The S3 breaking pattern in the quark sector is not studied and need further investigation. Since in such a model the number of free parameters is greater than the number of experimental observables, an analytical fit of all the parameters is impossible. To go forward with the model building and to deal with this problem we have used a statistical analysis. We have found that S3 is totally broken and the up-type quarks matrix is approximatively diagonal while down-type quarks matrixis not symmetric and it is parametrized by three couplings, gd, gLd and g3d. It has been found that gLd is slightly smaller than gd=1 and it is of order one, while g3d \sim l^3 where l is the Cabibbo angle. An analytical study of the dependence of Vcb and Vub from the couplings gLd and g3d is also presented.