Flavour parametrization of couplings with fermions in the 2HDM: the case with the 4-zero texture mass matrix

The 2HDM has been one of the most studied extensions of the SM, due to its simple form and wealthy new phenomenology. Most versions are characterized by the mechanism through which the FCNC are controlled. In order to give to the 2HDM the status of an intermediate step in the rank of energies (that is, a low energy limit between the electroweak scale and the characteristic scale of the general theory), a mechanism to relate several versions of the 2HDM is given. This mechanism exploits the flavour symmetry of the Yukawa Lagrangian and the fact that the mass generation comes from a yet unknown property of the vacuum but related with the CKM entries in the case of quarks.