On the universal texture in the PA-2HDM for the V-spin case

Abstract

In a version of the PA-2HDM where only mixing between third and second fermion generations is allowed, we propose a mechanism to generate the second Yukawa matrix through a Unitary V-spin flavor transformation on the mass matrix for quarks and leptons. This flavor structure is constrained to be universal, that is, we use the same parameters to generate Yukawa matrix elements in the quark and leptonic sectors, reducing drastically the number of free parameters of the PA-2HDM. As a consequence of this restrictive condition, we obtain relations between the Yukawa matrix elements, that we call the Universal Texture Constraint (UTC). We obtained an interval of values for the second Yukawa matrix elements, expressed in terms of the Cheng and Sher ansatz, for [Formula: see text] and [Formula: see text] coming from the UTC and experimental bounds for light scalar masses. Finally, we find the allowed parameter region when the experimental bounds and values for [Formula: see text] decays, [Formula: see text] mixing, [Formula: see text] and [Formula: see text] are considered.