| The study of the properties of weak decay pseudo-standard mesons has always been one of the important research directions in particle physics.In recent years,with the advent of excited particles in the experiment,it is believed that these new particles are likely to be radially excited.Therefore,we expect further study of multiple decay paths in the high-excited state of the meson,which can help us to discover the weak decay properties of the pseudo-standard mesons,to understand the interaction between the quarks in the elementary particles more deeply,and to further verify the application of the standard model The Therefore,this paper needs to study the high-excited state mesoncer in the standard model more carefully,which is why we choose the weak decay of the meson as the research object.Of course,as the weak meson weak decay itself is worth studying.The Bethe-Salpeter equation is the most classical method to deal with the mesonbound state,which plays a very important role in the weak decay of the heavy meson.Moreover,the high excited state particles studied in this paper need relativistic correction.The BS equation satisfies the conditions of relativity and quantum field theory,which can be used to describe the problem of heavy meson bound state.However,it is very difficult to solve the BS equation directly.The eigenvalue and the eigenvalue function of the relativistic correction are obtained by using the instantaneous approximate Salpeter equation for the radial high excited states of the meson.Then the kernel of the hadron matrix is solved by Mandelstam mechanism,and the integral of the wave function is overlapped.Finally,the decay width and branching ratio of the main semi-light decay path are obtained,and the results are analyzed and the semi-light decay properties are studied.The main research goal of this paper is to calculate the meson generation rate,that is,the decay width and branching ratio,of the decay path by BS equation.In this paper,the method of instantaneous approximation can be selected to make the meson wave function form to be studied more accurate.The decay reaction of the radial excited interphase is strongly influenced by relativistic theory.The weak decay of the heavy meson in the study state can not only help us to understand the role of relativistic correction,but also can be different from the ground state meson.The conclusion can be fully explained that the instantaneous approximation of the BS equation method is a reliable method to study the weak decay of the radial excited state heavy meson.In the paper,the main idea of this paper is to determine the Feynman diagram of the decaying process of the decay path by using the Feynman rule to derive the transition matrix element of the charm quark.After the instantaneous approximation of the BS equation is simplified,the wave equation of the initial state is constructed under the constraint condition.Secondly,the parameters and the reasons for the numerical calculation are introduced in detail.The numerical values of the integral factor are obtained by Mathematica and Fortran programming software,and the lepton spectrum is obtained,and the numerical solution of the weak matrix elements and the shape factor are calculated.The Finally,the matrix element square is substituted into the decay width formula and is compared with the total decay width to obtain the final branching ratio numerical result.In the paper,the results of numerical operation are compared with other groups,and the comparison results are analyzed and discussed.The results show that the numerical results of the model are very small,and the correctness of the program and the reliability of the model are verified.It shows that the BS equation model is a reliable and effective method to study the problem of the bound state of the heavy meson.The analysis and conclusion in the article deepens the understanding of the scope of application of the standard model,and it is expected to help the LHC-b detection experiment and data analysis. |
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