Inclusion of Z->b b-bar vertex corrections in Precision Electroweak Tests on the Sp(6)_L X U(1)_Y Model

We extend our previous work on the precision electroweak tests in the Sp(6)_L X U(1)_Y family model to include for the first time the important Z->b b-bar vertex corrections encoded in a new variable epsilon_b, utilizing all the latest LEP data. We include in our analysis the one loop EW radiative corrections due to the new bosons in terms of epsilon_1, epsilon_b and $\Delta\Gamma_Z$. We find that the correlation between epsilon_1 and epsilon_b makes the combined constraint much stronger than the individual ones. The model is consistent with the recent CDF result of m_t=174\pm 10^{+13}_{-12}\GeV, but it can not accomodate m_t\gsim 195\GeV.Comment: Latex, 16 pages+4 figures(not included but available as uuencoded or PS files from [email protected]), PURD-TH-94-08, SNUTP-94-4

Precision Electroweak Tests on the Sp(6)L×U(1)YSp(6)_L \times U(1)_Y Model

We perform precision electroweak tests on the $Sp(6)_L \times U(1)_Y$ model. The purpose of the analysis is to delineate the model parameters such as the mixing angles of the extra gauge bosons present in this model. We find that the model is already constrained considerably by the present LEP data.Comment: 14 pages+2 figures(not included), PURD-TH-93-13, to appear in Phys. Rev. D(figures available upon request by regular mail

Flavor Mixing and the Permutation Symmetry among Generations

In the standard model, the permutation symmetry among the three generations of fundamental fermions is usually regarded to be broken by the Higgs couplings. It is found that the symmetry is restored if we include the mass matrix parameters as physical variables which transform appropriately under the symmetry operation. Known relations between these variables, such as the renormalization group equations, as well as formulas for neutrino oscillations (in vacuum and in matter), are shown to be covariant tensor equations under the permutation symmetry group.Comment: 12 page

Rephasing invariance and neutrino mixing

A rephasing invariant parametrization is introduced for three flavor neutrino mixing. For neutrino propagation in matter, these parameters are shown to obey evolution equations as functions of the induced neutrino mass. These equations are found to preserve (approximately) some characteristic features of the mixing matrix, resulting in solutions which exhibit striking patterns as the induced mass varies. The approximate solutions are compared to numerical integrations and found to be quite accurate.Comment: 18 pages, 6 figure

Renormalization of the Neutrino Mass Matrix

In terms of a rephasing invariant parametrization, the set of renormalization group equations (RGE) for Dirac neutrino parameters can be cast in a compact and simple form. These equations exhibit manifest symmetry under flavor permutations. We obtain both exact and approximate RGE invariants, in addition to some approximate solutions and examples of numerical solutions.Comment: 15 pages, 1figur