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We present an improved quark mass density-dependent model which includes the quark and non-linear scalar field coupling. The wavefunction of quark is given. The rms charge radius, the magnetic moment, and the ratio between the axial-vector and the vector β-decay coupling constants of the nucleon are calculated. We find that the results given the present model are in agreement with experiments.  相似文献   

3.
We propose a new mass matrix ansatz: At the grand unified (GU) scale, the standard model (SM) Yukawa coupling matrix elements are integer powers, of the square root of the GU gauge coupling constant ε ≡√αGU, multiplied by order unity random complex numbers. It relates the hierarchy of the SM fermion masses and quark mixings to the gauge coupling constants, greatly reducing the SM parameters, and can give good fitting results of the SM fermion mass, quark mixing and CP violation parameters. This is a neat but very effective ansatz.  相似文献   

4.
In this paper, we study the upper bounds on the mass insertion parameters (δAB^q)ij in the minimal super symmetric standard model. We found that the information from the measured branching ratio of B→ X8γ, X8l+l- decay can help us to improve the upper bounds on the mass insertions parameters (δAB^u,d)3j,i3 Some regions allowed by the data of Br(B→ X8γ) are excluded by the requirement of an SM-like C7γ (rnb) imposedby the data of Br(B→ X8γ, X8l+l- ).  相似文献   

5.
Using the form factors from light-cone sum rules, we study the branching ratios and forward-backward asymmetries (FBAs) of the exclusive decays Bu^+→π^+e^+e^- and Bu^+ →ρ^+e^+e^- (e= e,μ) in the standard model (SM) and the top quark two-Higgs-doublet model (T2HDM). From the numerical results, we find that the new physics contributions cannot provide very large enhancement to the branching ratios and the theoretical predictions are in good agreement with the SM ones. The T2HDM effects on FBAs of these decays are small. Precision measurements of the dilepton invariant mass distributions, especially in the lower dilepton mass region, and the FBAs in the decays Bu^+ → π^+ (ρ^+ )e^+ e^- will greatly help in discriminating among the SM and the new physics models.  相似文献   

6.
Based on the light-cone effective Hamiltonian with confining potential and SU (3) flavor mixing interactions, the flavor mixing mesons on the u, d, and s quark sectors are investigated. The mass eigen equations of the flavor mixing vector and pseudo vector mesons are solved. The calculated masses are in good agreement with the experimental data.  相似文献   

7.
There are some uncertain charazteristics of the Ds1(2536), which deserves further discussion. Based on the assumption that the meson is constituted by c s, and belongs to T doublet (1^+, 2^+), radiative decays Ds1(2536) → Ds(1968) +γ and Ds1(2536) → Ds^*(2112) + γ are studied in the CQM model The large branching ratios of them from our calculations not only indicate the process may be detected in the future experiments, but also can give a deep comprehension of the structure of it.  相似文献   

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