Some Standard model problems and possible solutions

Three problems of the standard model of elementary particles are studied from a phenomenological approach. (i) It is shown that the Dirac or the Majorana nature of the neutrino can be studied by looking for differences in the v -electron scattering if the polarization of the neutrino is considered. (ii) The absolute scale of the neutrino mass can be set if a four zero mass matrix texture is considered for the leptons. It is found that m _ν3 ∼âƒ' 0.05 eV. (iii) It is shown that it is possible -within a certain class of two Higgs model extensions of the standard model- to have a cancelation of the quadratic divergences to the mass of physical Higgs boson. (paper)