The electromagnetic transition between the nucleon and excited baryons has long been recognized as an important source of information for understanding strong interactions in the domain of quark confinement. We study ...The electromagnetic transition between the nucleon and excited baryons has long been recognized as an important source of information for understanding strong interactions in the domain of quark confinement. We study the electromagnetic properties of the excitation of the negative parity the N~*(1535) resonances in the nonrelativistic constituent quark model at large momentum transfers and have performed a calculation the longitudinal and transverse helicity amplitudes. Since the helicity amplitudes depend strongly on the quark wave function in this paper, we consider the baryon as a simple, non-relativistically three-body quark model and also consider a hypercentral potential scheme for the internal baryon structure, which makes three-body forces among three quarks. Since the hyper central potential depends only on the hyper radius, therefore, the Cornell potential which is a combination of the Coulombic-like term plus a linear confining term is considered as the potential for interaction between quarks. In our work, in solving the Schrodinger equation with the Cornell potential, the Nikiforov–Uvarov method employed, and the analytic eigen-energies and eigen-functions obtained. By using the obtained eigen-functions, the transition amplitudes calculated. We show that our results in the range Q^2> 2GeV^2 lead to an overall better agreement with the experimental data in comparison with the other three non-relativistic quark models.展开更多
The decay constants of the low lying S-wave B_(c)mesons,i.e.B_(c)(nS) and B_(c)^(*)(nS) with n ≤3,are calculated in the nonrelativistic quark model.The running coupling of the strong interaction is taken into account...The decay constants of the low lying S-wave B_(c)mesons,i.e.B_(c)(nS) and B_(c)^(*)(nS) with n ≤3,are calculated in the nonrelativistic quark model.The running coupling of the strong interaction is taken into account,and the uncertainties due to varying parameters and losing Lorentz covariance are considered carefully.As a byproduct,the decay constants of the low lying S-wave charmonium and bottomium states are given in the appendixes.展开更多
文摘The electromagnetic transition between the nucleon and excited baryons has long been recognized as an important source of information for understanding strong interactions in the domain of quark confinement. We study the electromagnetic properties of the excitation of the negative parity the N~*(1535) resonances in the nonrelativistic constituent quark model at large momentum transfers and have performed a calculation the longitudinal and transverse helicity amplitudes. Since the helicity amplitudes depend strongly on the quark wave function in this paper, we consider the baryon as a simple, non-relativistically three-body quark model and also consider a hypercentral potential scheme for the internal baryon structure, which makes three-body forces among three quarks. Since the hyper central potential depends only on the hyper radius, therefore, the Cornell potential which is a combination of the Coulombic-like term plus a linear confining term is considered as the potential for interaction between quarks. In our work, in solving the Schrodinger equation with the Cornell potential, the Nikiforov–Uvarov method employed, and the analytic eigen-energies and eigen-functions obtained. By using the obtained eigen-functions, the transition amplitudes calculated. We show that our results in the range Q^2> 2GeV^2 lead to an overall better agreement with the experimental data in comparison with the other three non-relativistic quark models.
基金Supported by the National Natural Science Foundation of China (12005060)。
文摘The decay constants of the low lying S-wave B_(c)mesons,i.e.B_(c)(nS) and B_(c)^(*)(nS) with n ≤3,are calculated in the nonrelativistic quark model.The running coupling of the strong interaction is taken into account,and the uncertainties due to varying parameters and losing Lorentz covariance are considered carefully.As a byproduct,the decay constants of the low lying S-wave charmonium and bottomium states are given in the appendixes.
