Solving the Bethe–Salpeter Equation in Euclidean Space

Few-Body Systems - Tập 49 - Trang 233-246 - 2010
S. M. Dorkin1,2, L. P. Kaptari1,3, C. Ciofi degli Atti3, B. Kämpfer4
1Bogoliubov Laboratory of Theoretical Physics, JINR, Dubna, Russia
2International University “Dubna,”, Dubna, Russia
3Department of Physics, University of Perugia and INFN, Sezione di Perugia, Perugia, Italy
4Forschungszentrum Dresden-Rossendorf, Dresden, Germany

Tóm tắt

Different approaches to solve the spinor–spinor Bethe–Salpeter (BS) equation in Euclidean space are considered. It is argued that the complete set of Dirac matrices is the most appropriate basis to define the partial amplitudes and to solve numerically the resulting system of equations with realistic interaction kernels. Other representations can be obtained by performing proper unitary transformations. A generalization of the iteration method for finding the energy spectrum of the BS equation is discussed and examples of concrete calculations are presented. Comparison of relativistic calculations with available experimental data and with corresponding non relativistic results together with an analysis of the role of Lorentz boost effects and relativistic corrections are presented. A novel method related to the use of hyperspherical harmonics is considered for a representation of the vertex functions suitable for numerical calculations.

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