Covariant separable interaction for the neutron–proton system in – partial-wave state

Abstract

Within a covariant Bethe-Salpeter approach a rank-six separable neutron-proton interaction kernel for the triplet coupled 3 S 1 -3 D 1 partial-wave state is constructed. Two different methods of a relativistic generalization of initially nonrelativistic form factors parametrizing the kernel are considered. The model parameters are determined by fitting the elastic 3 S 1 and 3 D 1 phase shifts and the triplet scattering length as well as the asymptotic D/S ratio of the deuteron wave functions and the deuteron binding energy. The D-state probability constraints 4-7% are taken into account. The deuteron magnetic moment is calculated. The half-off-shell properties are further demonstrated by the Noyes-Kowalski functions. The first test of the constructed kernel is performed by calculating the deuteron electrodisintegration at three different kinematic conditions.

Covariant Relativistic Separable Kernel Approach for Electrodisintegration of the Deuteron at High Momentum Transfer

“…In this paper the exclusive cross section of electrodisintegration (19) for kinematic conditions of the JLab experiment [1] has been calculated within the Bethe-Salpeter approach with the rank-six separable kernel MY6 [15]. The calculations have been performed within the relativistic PWIA.…”

“…They are written in the deuteron rest frame. The MY6 model [15] (MY6-S red solid line corresponds to 3 S + 1 partial-wave state, MY6-D red dashed line -to 3 D + 1 ) is compared with Graz II [11] (Graz II-S brown dash-dotted line -3 S + 1 wave function, Graz II-D brown dotted line -3 D + 1 wave function).…”

Final state interaction effects in exclusive electrodisintegration of the deuteron

“…Thus, the problem of solving the initial integral BS equation ( 7) turns out to finding functions g i and parameters λ ij of separable representation (11). They can be obtained from a description of observables in np elastic scattering [9,10,18,19,20].…”

“…However, the approach was not applicable for the most of high-energy NN processes for a while since calculated expressions contained nonintegrable singularities. The problem was solved in [8,9,10] where kernels of special type were proposed. Using them FSI can be taken into account (in particular, considering the electrodisintegration) in a wide range of energy.…”

“…In the present paper, the electrodisintegration cross section is calculated under different kinematic conditions of Bonn experiments [11,12]. The rank-six NN interaction potential MY6 [9] is used to describe scattered states 3 S 1 -3 D 1 and the deuteron. The uncoupled partial-wave states with total angular momentum J = 0, 1 ( 1 S 0 , 1 P 1 , 3 P 0 , 3 P 1 ) are described by multirank separable potentials [10].…”