arXiv subjects
Publications and source records attributed to A. Zepeda.
We study topological defects arising in the Grand Unification Model $SU(6)_L\otimes SU(6)_c \otimes SU(6)_R \times Z_3$. We show that the model does not contain domain walls, while it produces massive magnetic monopoles and it may, depending on the symmetry breaking chain, give rise to the formation of strings. We also discuss their possible relation$ the origin of the highest energy cosmic rays detected.
Lepton family number violation processes arise in the $SU(6)_L \otimes U(1)_Y$ model due to the presence of an extra neutral gauge boson, Z$'$, with family changing couplings, and due to the fact that this model demands the existence of heavy exotic leptons. The mixing of the standard Z with Z$'$ and the mixing of ordinary leptons with exotic ones induce together family changing couplings on the Z and therefore nonvanishing rates for lepton family number violation processes, such as $Z \to e \barμ$, $μ\to ee\bar{e}$ and $μ\to eγ$. Additional contributions to the processes $μ\to e γ$ and $μ\to ee \bar{e}$ are induced from the mass generation mechanism. This last type of contributions may compete with the above one, depending on the masses of the scalars which participate in the diagrams which generate radiatively the masses of the charged leptons. Using the experimental data we compute some bounds for the mixings parameters and for the masses of the scalars.
Some textbooks and reports claim that the Jacobian which arises in the discussion of the Faddeev-Popov method to quantize non-Abelian gauge theories and which is given by the derivative of the gauge fixing conditions over the gauge group parameters, is gauge invariant. Other references however prove the opposite. In this brief report we present a discussion about this matter.