arXiv subjects

K. C. Chou

Publications and source records attributed to K. C. Chou.

8 recordsLinked to original sources

arXiv2001

Predictive SUSY GUT Model for CP Violation, Fermion Masses and Mixings

CP violation, fermion masses and mixing angles including that of neutrinos are studied in an SUSY SO(10)$\times Δ(48)\times$ U(1) model. The nonabelian SU(3) discrete family symmetry $Δ(48)$ associated with a simple scheme of U(1) charge assignment on various fields concerned in superpotential leads to unique Yukawa coupling matrices with zero textures. Thirteen parameters involving masses and mixing angles in the quark and charged lepton sector are successfully predicted by only four parameters. The masses and mixing angles for the neutrino sector could also be predicted by constructing an appropriate heavy Majorana neutrino mass matrix without involving new parameters. It is found that the atmospheric neutrino deficit, the mass limit put by hot dark matter and the LSND $\barν_μ \to \barν_{e}$ events may simultaneously be explained, but solar neutrino puzzle can be solved only by introducing a sterile neutrino. An additional parameter is added to obtain the mass and mixing of the sterile neutrino. The hadronic parameters $B_{K}$ and $f_{B}\sqrt{B}$ are extracted from the observed $K^{0}$-$\bar{K}^{0}$ and $B^{0}$-$\bar{B}^{0}$ mixings respectively. The direct CP violation ($ε'/ε$) in kaon decays and the three angles $α$, $β$ and $γ$ of the unitarity triangle in the CKM matrix are also presented. More precise measurements of $α_{s}(M_{Z})$, $|V_{cb}|$, $|V_{ub}/V_{cb}|$, $m_{t}$, as well as various CP violation and neutrino oscillation experiments will provide an important test for the present model and guide us to a more fundamental theory.

hep-ph↗

arXiv2000

Searching for Rephase-Invariant CP- and CPT-violating Observables in Meson Decays

We present a general model-independent and rephase-invariant formalism that cleanly relates CP and CPT noninvariant observables to the fundamental parameters. Different types of CP and CPT violations in the K^0-, B^0-, B_s^0- and D^0-systems are explicitly defined. Their importance for interpreting experimental measurements of CP and CPT violations is emphasized. In particular, we show that the time-dependent measurements allow one to extract a clean signature of CPT violation.

hep-ph↗

arXiv1997

Predictive SUSY SO(10) X Delta (48) X U(1) Model for CP Violation, Neutrino Oscillation, Fermion Masses and Mixings with Small tan(beta)

CP violation, fermion masses and mixing angles including that of neutrinos are studied in an SUSY SO(10)$\times Δ(48)\times$ U(1) model with small $\tan β$. The family symmetry $Δ(48)$ associated with a simple scheme of U(1) charge assignment on various fields concerned in superpotential leads to unique Yukawa coupling matrices with zero textures. Thirteen parameters involving masses and mixing angles in the quark and charged lepton sector are successfully predicted by only four parameters. The masses and mixing angles for the neutrino sector can also be predicted without involving new parameters. It is found that the atmospheric neutrino deficit, the mass limit put by hot dark matter and the LSND $\barν_μ \to \barν_{e}$ events can be naturally explained. Solar neutrino puzzle can be solved only by introducing a sterile neutrino. An additional parameter is added to obtain the mass and mixing of the sterile neutrino. The hadronic parameters $B_{K}$ and $f_{B}\sqrt{B}$ are extracted from the observed $K^{0}$-$\bar{K}^{0}$ and $B^{0}$-$\bar{B}^{0}$ mixings respectively. The direct CP violation ($ε'/ε$) in kaon decays and the three angles $α$, $β$ and $γ$ of the unitarity triangle in the CKM matrix are also presented. More precise measurements of $α_{s}(M_{Z})$, $|V_{cb}|$, $|V_{ub}/V_{cb}|$, $m_{t}$, as well as various CP violation and neutrino oscillation experiments will provide an important test for the present model and guide us to a more fundamental theory.

hep-ph↗

arXiv1996

A solution to the puzzles of CP violation, neutrino oscillation, fermion masses and mixings in an SUSY GUT model with small $tan β$

CP violation, fermion masses and mixing angles including that of neutrinos are studied in an SUSY SO(10)$\times Δ(48) \times$ U(1) model with small $tan β$. It is amazing that the model can provide a successful prediction on twenty three observables by only using four parameters. The renormalization group (RG) effects containing those above the GUT scale are considered. Fifteen relations among the low energy parameters are found with nine of them free from RG modifications. They could be tested directly by low energy experiments.

hep-ph↗

arXiv1996

A Predictive SUSY SO(10) X Delta (48) X U(1) Model for CP Violation, Neutrino Oscillation, Fermion Masses and Mixings with Very Low tan(beta)

Assuming universality of Yukawa coupling of the superpotential and maximal spontaneous CP violation, fermion masses and mixing angles including that of neutrinos are studied in an SUSY SO(10)$\times Δ(48)\times$ U(1) model with small $\tan β$. The low energy parameters of the standard model are determined solely by the Clebsch factors of the symmetry group and the structure of the physical vacuum. Thirteen parameters involving masses and mixing angles in the quark and charged lepton sector are successfully predicted by only four parameters with three of them determined by the scales of U(1)$\times Δ(48)$, SO(10), SU(5) and SU(2)$_{L}$ symmetry breakings. An interesting prediction on ten parameters concerning the neutrino sector is also made by using the same four parameters. An additional parameter is added to obtain the mass and mixing of a sterile neutrino. It is found that the LSND $\barν_μ \rightarrow \barν_{e}$ events, atmospheric neutrino deficit and the mass limit put by hot dark matter can be naturally explained. Solar neutrino puzzle can be solved only by introducing a sterile neutrino. $(ν_{e} - ν_τ)$ oscillation is found to have the same sensitive region as the $(ν_{e} - ν_μ)$ oscillation. The hadronic parameters $B_{K}$ and $f_{B}\sqrt{B}$ are extracted from the observed $K^{0}$-$\bar{K}^{0}$ and $B^{0}$-$\bar{B}^{0}$ mixings respectively. The direct CP violation ($\varepsilon'/\varepsilon$) in kaon decays and the three angles $α$, $β$ and $γ$ of the unitarity triangle in the CKM matrix are also presented. More precise measurements of $α_{s}(M_{Z})$, $|V_{cb}|$, $|V_{ub}/V_{cb}|$, $m_{t}$, as well as various CP violation and neutrino oscillation experiments will provide crucial tests for the present model.

hep-ph↗

arXiv1996

CP Violation, Fermion Masses and Mixings in a Predictive SUSY SO(10) X Delta (48) X U(1) Model with Small tan(beta)

Fermion masses and mixing angles are studied in an SUSY $SO(10)\times Δ(48)\times U(1)$ model with small $\tanβ$. Thirteen parameters involving masses and mixing angles in the quark and charged lepton sector are successfully predicted by a single Yukawa coupling and three ratios of VEVs caused by necessary symmetry breaking. Ten relations among the low energy parameters have been found with four of them free from renormalization modifications. They could be tested directly by low energy experiments.

hep-ph↗

arXiv1995

Low Energy Phenomena in a Model With Symmetry Group SUSY SO(10) X Delta (48) X U(1)

Fermion masses and mixing angles including that of neutrinos are studied in a model with symmetry group SUSY $SO(10)\times Δ(48) \times U(1)$. Universality of Yukawa coupling of superfields is assumed. The resulting texture of mass matrices in the low energy region depends only on a single coupling constant and VEVs caused by necessary symmetry breaking. 13 parameters involving masses and mixing angles in the quark and charged lepton sector are successfully described by only five parameters with two of them determined by the scales of U(1), SO(10) and SU(5) symmetry breaking compatible with the requirement of grand unification and proton decay. The neutrino masses and mixing angles in the leptonic sector are also determined with the addition of a Majorana coupling term. It is found that LSND $\barν_μ\rightarrow \barν_{e}$ events, atmospheric neutrino deficit and the mass limit put by hot dark matter can be naturally explained. Solar neutrino puzzle can be solved only by introducing sterile neutrino with one additional parameter. More precise measurements of $α_{s}(M_{Z})$, $V_{cb}$, $V_{ub}/V_{cb}$, $m_{b}$, $m_{t}$, as well as various CP violation and neutrino oscillation experiments will provide crucial tests of the present model.

hep-ph↗

arXiv1995

A Predictive Superunification $SO(10)\times Δ_{48}(SU(3))\times U(1)$ Model for Fermion Masses and Mixings

Based on a few basic assumptions, a predictive supersymmetric grand unification $G_{U}=SO(10)\times Δ_{48}(SU(3))\times U(1)$ model is proposed. Thus, all the observed 45 chiral fermions with additional 3 right-handed neutrinos are unified into an irreducible triplet 16-dimensional spinor representation of $G_{U}$. Electroweak symmetry breaking naturally requires two Higgs doublets which belong to a single 10 representation of $SO(10)$. The model provides an unified description for all the Yukawa and gauge couplings. With a given structure of the physical vacuum, the fermion masses and mixings are predicted in terms of two basic parameters.

hep-ph↗