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Based on the fully dressed quark propagator and chiral perturbation theory, we study the ratio of the strange quark mass ms to up or down quark mass mu,d . The ratio is related to the determination of quark masses which are fundamental input parameters of QCD Lagrangian in the Standard Model of particle physics and can not be directly measured since the quark is confined within a hadron. An accurate determination of these QCD free parameters is extremely important for both phenomenological and theoretical applications. We begin with a brief introduction to the non-perturbation QCD theory, and then study the mass ratio in the framework of the chiral perturbation theory (χPT) with a parameterized fully dressed quark propagator which describes confining fully dressed quark propagation and is analytic everywhere in the finite complex p2-plane and has no Lehmann representation so there are no quark production thresholds in any theoretical calculations of observable data. Our prediction for the ratio ms/mu,d is consistent with other model predictions such as Lattice QCD, instanton model, QCD sum rules and the empirical values used widely in the literature. As a by-product of this study, our theoretical results, together with other predictions of physical quantities that used this quark propagator in our previous publications, clearly show that the parameterized form of the fully dressed quark propagator is an applicable and reliable approximation to the solution of the Dyson-Schwinger Equation of quark propagator in the QCD. 相似文献
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几何光学中近轴条件引入误差的讨论彭金松(广西河池师专物理系宜州546300)在几何光学中,所用的成象公式都是在近轴条件下得出来。而近轴条件,在教材中一般是这样描述的,即光线的入射角很小,光线与光轴的夹角也很小。而对于这个条件的引入,到底会带来多少误差... 相似文献
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在超重核区(Z≥104)使用文献[7—9]给出的3组参数应用Viola-Seaborg公式计算了α衰变寿命,所得结果与实验值进行比较,发现其结果与实验值相差较大。为此,利用最小二乘法分别在重核区和超重核区重新对参数进行了拟合,得到的计算结果与实验值相比符合得较理想,尤其是由超重核得到的参数的结果非常理想。 相似文献
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α decay energies of 323 heavy nuclei with Z≥82 are evaluated with a macroscopic-microscopic model. In this model, the macroscopic part is treated by the continuous medium model and the microscopic part consists of shell and pairing corrections based on the Nilsson potential. α decay half-lives are calculated by Viola-Seaborg formula. The results of α decay energies and half-lives are compared with experimental values and satisfactory agreement is found. The recoiling effect of the daughter nucleus on α decay half-life is also discussed. 相似文献
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在超重核区(Z≥104)使用文献[7—9]给出的3组参数应用Viola Seaborg公式计算了α衰变寿命, 所得结果与实验值进行比较, 发现其结果与实验值相差较大。 为此, 利用最小二乘法分别在重核区和超重核区重新对参数进行了拟合, 得到的计算结果与实验值相比符合得较理想, 尤其是由超重核得到的参数的结果非常理想。The α decay half lives of the super heavy nuclei in the mass region (Z≥104) were calculated by Viola Seaborg formula with three sets of parameters. The calculated results show that all the three sets of parameters caused rather large deviations from the experimental data. To solve this problem, we have done a parameter fitting in the regions of heavy nuclei and super heavy nuclei respectively, with the least squares method. With the new sets of parameters, the calculated α decay half lives are in much better agreement with the experimental data. In particular, the results calculated with the new parameters in the region of super heavy nuclei are even better. 相似文献
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