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Wei-Min Yang

Publications and source records attributed to Wei-Min Yang.

32 records · Page 2Linked to original sources
arXiv2009

The New Extended Left-Right Symmetric Grand Unified Model with SO(3) Family Symmetry

We suggest a new left-right symmetric grand unified model by extending Pati-Salam group to contain an isospin SU(2) and a flavor SO(3) subgroup, where the superheavy fermions are introduced as a mirror to the low-energy standard model fermions. The model undergoes three steps to break to the SM by means of the specified Higgs multiplets. The model few parameters can elegantly accommodate whole mass spectra for all the particles at the electroweak scale, especially, two different flavor mixing for the quark and lepton sectors are reproduced in agreement with the current experimental data very well. The strong CP violation is excellently explained. The matter-antimatter asymmetry in the universe is successfully implemented through the B-L violating decays of the superheavy gauge bosons. The model also predicts that the lightest right-handed Majorana neutrino, whose mass is about several hundred GeVs and energy is about $10^{16}$ GeV, is possibly a candidate for the dark matter.

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arXiv2006

Axial form-factor and induced pseudoscalar form-factor of the nucleons

In this article, we calculate the axial and the induced pseudoscalar form-factors $G_A(t=-Q^2)$ and $G_P(t=-Q^2)$ of the nucleons in the framework of the light-cone QCD sum-rules approach up to twist-6 three valence quark light-cone distribution amplitudes, and observe that the form-factors $G_A(t=-Q^2)$ and $G_P(t=-Q^2)$ at intermediate and large momentum transfers with $Q^2> 2 GeV^2$ have significant contributions from the end-point (soft) terms. The numerical values for the axial form-factor $G_A(t=-Q^2)$ are compatible with the experimental data and theoretical calculations, for example, the chiral quark models and lattice QCD. The numerical values for the induced pseudoscalar form-factor $G_P(t=-Q^2)$ are compatible with the calculation from the Bethe-Salpeter equation.

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arXiv2006

Scalar form-factor of the proton with light-cone QCD sum rules

In this article, we calculate the scalar form-factor of the proton in the framework of the light-cone QCD sum rules approach with the three valence quark light-cone distribution amplitudes up to twist-6, and observe the scalar form-factor $σ(t=-Q^2)$ at intermediate and large momentum transfers $Q^2> 2GeV^2$ has significant contributions from the end-point (or soft) terms. The numerical values for the $σ(t=-Q^2)$ are compatible with the calculations from the chiral quark model and lattice QCD at the region $Q^2>2GeV^2$.

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arXiv2005

Decay width of the pentaquark state $Θ^+(1540)$ with QCD sum rules

In this article, we take the point of view that the pentaquark state $Θ^+(1540)$ has negative parity, and choose the diquark-triquark type interpolating current to calculate the strong coupling constant $g_{ΘNK}$ in the QCD sum rule approach. Our numerical results indicate the values of the strong coupling constant $g_{ΘNK}$ are very small, $|g_{ΘNK}|=0.175\pm0.084$, and the width $Γ_Θ<4MeV$, which can explain the narrow width $Γ\leq 10 MeV$ naturally.

hep-ph↗
arXiv2005

Magnetic moment of the pentaquark $Θ^+(1540)$ as diquark-diquark-antiquark state with QCD sum rules

In this article, we study the magnetic moment of the pentaquark state $ Θ^+(1540)$ as diquark-diquark-antiquark ($[ud][ud]\bar{s}$) state with the QCD sum rules in the external weak electromagnetic field (EFSR) and the light-cone QCD sum rules (LCSR) respectively. The numerical results indicate the magnetic moment is about $μ_{Θ^+}=-(0.11\pm 0.02)μ_N$ for the EFSR and $μ_{Θ^+}\approx-(0.1-0.5)μ_N$ for the LCSR. As the values obtained from the EFSR are more stable than the corresponding ones from the LCSR, $μ_{Θ^+}=-(0.11\pm 0.02)μ_N$ is more reliable.

hep-ph↗
arXiv2005

Analysis the $0^{++}$ nonet mesons as four-quark states with the QCD sum rules

In this article, we take the point of view that the $0^{++}$ nonet mesons below $1 GeV$ are diquark-antidiquark states $(qq)_{\bar{3}}(\bar{q}\bar{q})_3$, and devote to determine their masses in the framework of the QCD sum rules approach with the interpolating currents constructed from scalar-scalar type and pseudoscalar-pseudoscalar type diquark pairs respectively. The numerical results indicate that the $0^{++}$ nonet mesons may have two possible diquark-antidiquark substructures.

hep-ph↗
arXiv2005

Magnetic moment of the pentaquark $Θ^+(1540)$ with QCD sum rules

In this article, we study the magnetic moment of the pentaquark state $ Θ^+(1540)$ with the QCD sum rules approach in the external electromagnetic field. The numerical results indicate the magnetic moment of the pentaquark state $ Θ^+(1540)$ is about $μ_{Θ^+}=(0.24\pm0.02)μ_N$.

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arXiv2005

Analysis the $f_0(980)$ and $a_0(980)$ mesons as four-quark states with the QCD sum rules

In this article, we take the point of view that the scalar mesons $ f_0(980)$ and $a_0(980)$ are diquark-antidiquark states $(qq)_{\bar{3}}(\bar{q}\bar{q})_3$, and devote to determine their masses in the framework of the QCD sum rules approach with the interpolating currents constructed from scalar-scalar type and pseudoscalar-pseudoscalar type diquark pairs respectively. The numerical results indicate that the scalar mesons $ f_0(980)$ and $a_0(980)$ may have two possible diquark-antidiquark substructures.

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arXiv2005

Decay constants of the pseudoscalar charmonium and bottomonium

In this article, we investigate the structures of the pseudoscalar charmonium and bottomonium in the framework of the coupled rainbow Schwinger-Dyson equation and ladder Bethe-Salpeter equation with the confining effective potential (infrared modified flat bottom potential). As the current masses are very large, the dressing or renormalization for the $c$ and $b$ quarks are tender, however, mass poles in the timelike region are absent. The Euclidean time fourier transformed quark propagator has no mass poles in the timelike region which naturally implements confinement. The Bethe-Salpeter wavefunctions for those mesons have the same type (Gaussian type) momentum dependence and center around zero momentum with spatial extension to about $q^2=1GeV^2$ which happen to be the energy scale for Chiral symmetry breaking, the strong interactions in the infrared region result in bound states. The decay constants for those pseudoscalar heavy quarkonia are compatible with the values of experimental extractions and theoretical calculations.

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arXiv2004

Decay constants of the pseudoscalar mesons in the framework of the coupled Schwinger-Dyson equation and Bethe-Salpeter equation

In this article, we investigate the structures of the pseudoscalar mesons ($π$, $K$, $D$, $D_s$, $B$ and $B_s$) in the framework of the coupled rainbow Schwinger-Dyson equation and ladder Bethe-Salpeter equation with the confining effective potential (infrared modified flat bottom potential). The Schwinger-Dyson functions for the $u$, $d$ and $s$ quarks are greatly renormalized at small momentum region and the curves are steep at about $q^2=1GeV^2$ which indicates an explicitly dynamical symmetry breaking. The Euclidean time fourier transformed quark propagators have no mass poles in the time-like region which naturally implements confinement. As for the $c$ and $b$ quarks, the current masses are very large, the renormalization are more tender, however, mass poles in the time-like region are also absent. The Bethe-Salpeter wavefunctions for those mesons have the same type (Gaussian type) momentum dependence and center around small momentum which indicate that the bound states exist in the infrared region. The decay constants for those pseudoscalar mesons are compatible with the values of experimental extractions and theoretical calculations, such as lattice simulations and QCD sum rules.

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arXiv2004

Fermion Masses and Flavor Mixing in A Supersymmetric SO(10) Model

we study fermion masses and flavor mixing in a supersymmetric SO(10) model, where $\mathbf{10}$, $\mathbf{120}$ and $\mathbf{\bar{126}}$ Higgs multiplets have Yukawa couplings with matter multiplets and give masses to quarks and leptons through the breaking chain of a Pati-Salam group. This brings about that, at the GUT energy scale, the lepton mass matrices are related to the quark ones via several breaking parameters, and the small neutrino masses arise from a Type II see-saw mechanism. When evolving renormalization group equations for the fermion mass matrices from the GUT scale to the electroweak scale, in a specific parameter scenario, we show that the model can elegantly accommodate all observed values of masses and mixing for the quarks and leptons, especially, it's predictions for the bi-large mixing in the leptonic sector are very well in agreement with the current neutrino experimental data.

hep-ph↗
arXiv2004

Decay constants of the pion and B mesons with the Bethe-Salpeter equation

In this article, we investigate the under-structures of the $π$ and B mesons in the framework of the Bethe-Salpeter equation with the bare quark-gluon vertex, bare quark propagator and the confining effective potential (infrared modified flat bottom potential) firstly. Although the bare quark propagator can not embody dynamical chiral symmetry breaking and has a mass pole in the time-like region, it can give reasonable results for the values of decay constants $f_π$ and $f_B$ compared with the values of experimental data and other theoretical calculations, such as lattice simulations and QCD sum rules. Secondly, we explore those mesons within the framework of the coupled rain-bow Schwinger-Dyson equation and ladder Bethe-Salpeter equation. The Schwinger-Dyson functions for the $u$ and $d$ quarks are greatly renormalized at small momentum region and the curves are steep which indicates an explicitly dynamical symmetry breaking. The Euclidean time fourier transformed quark propagator has no mass poles in the time-like region which naturally implements confinement. As for the $b$ quark, the current mass is very large, the renormalization is more tender, however, mass pole in the time-like region is also absent. The Bethe-Salpeter wavefunctions for both the $π$ and B mesons have the same type (Gaussian type) momentum dependence as the corresponding wavefunctions with the bare quark propagator, however, the quantitative values are changed and the values for the decay constants $f_π$ and $f_B$ are changed correspondingly.

hep-ph↗
arXiv2003

Studying the Bell--Steinberger relation

The Bell--Steinberger relation is analyzed. The questionable points of the standard derivation of this relation are discussed. It is shown that the use of a more accurate approximation than the one usually used in the derivation of this relation can lead to corrections to the right hand side of the standard Bell--Steinberger relation.

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