Quark-Lepton Masses and the Ckm Matrix in a String Inspired Model
Abstract
In the context of the Calabi-Yau string model we discuss the origin of characteristic pattern of quark-lepton masses and the CKM matrix. The discrete -symmetry is introduced and the is assigned to the -parity. The gauge symmetry at the string scale is broken into the standard model gauge group at an intermediate energy scale. At energies below the intermediate scale down-type quarks and also leptons are mixed with unobserved heavy states, respectively. On the other hand, there are no such mixings for up-type quarks. The large mixings between light states and heavy ones cause different mass pattern of leptons and down-type quarks from that of up-type quarks and yield a nontrivial CKM matrix for quarks but a trivial one for leptons. The mixing mechanism is illustrated using a two-generation toy model.
Cite
@article{arxiv.hep-ph/9511312,
title = {Quark-Lepton Masses and the Ckm Matrix in a String Inspired Model},
author = {Naoyuki Haba and Chuichiro Hattori and Masahisa Matsuda and Takeo Matsuoka and 26pages},
journal= {arXiv preprint arXiv:hep-ph/9511312},
year = {2007}
}