Fermion Families from Two Layer Warped Extra Dimensions

In extra dimensions, the quark and lepton mass hierarchy can be reproduced from the same order bulk mass parameters, and standard model fermion families can be generated from one generation in the high dimensional space. We try to explain the origin of the same order bulk mass parameters and address the family replication puzzle simultaneously. We show that they correlate with each other. We construct models that families are generated from extra dimensional space, and in the meantime the bulk mass parameters of same order emerge naturally. The interesting point is that the bulk mass parameters, which are in same order, correspond to the eigenvalues of a Schr\"{o}dinger-like equation. We also discuss the problem existing in this approach.Comment: 21 latex pages, final version to appear in JHE

A Model of Fermion Masses and Mixings Triggered by Family Problem in Warped Extra Dimensions

We suggest a model which addresses both the fermion mass hierarchy problem and the family problem in two-layer warped extra dimensions. In this model, 3 family fermions in 4 dimensions (4D) generate from 1 family in two-layer warped 6D by two step Kluza-Klein decompositions. The mass hierarchies are produced by the exponential behavior of 4D fermion zero mode profiles. The mixings and masses of fermions are closely related to the family problem. By adjusting parameters in this model, the numerical results can be very close to the experimental data both in the quark sector and in the lepton sector. In the lepton sector, we suppose neutrinos to be Dirac ones. The neutrino masses of sub-$\mathrm{eV}$ scale are obtained, and also CP violation emerges in the lepton sector.Comment: 49 latex pages, 1 figure, final version in journal publicatio