On the covariant relativistic separable kernel

TL;DR

This paper compares two methods for constructing covariant relativistic separable kernels within the Bethe-Salpeter framework, demonstrating their effectiveness in reproducing neutron-proton phase shifts and comparing results with existing models.

Contribution

It introduces and compares two different covariant relativistic kernel construction methods in the Bethe-Salpeter approach, with applications to neutron-proton scattering.

Findings

Both methods successfully reproduce neutron-proton phase shifts.

Constructed covariant functions are consistent with experimental data.

Results are comparable with other existing models.

Abstract

Two different methods of the covariant relativistic separable kernel construction in the Bethe-Salpeter approach are considered. One of them leads in the center-of-mass system of two particles to the quasipotential equation. The constructed 4-dimensional covariant functions are used to reproduce neutron-proton phase shifts for total angular momenta $J=0,1$. Obtained results are compared with other model calculations.