Within a covariant Bethe-Salpeter approach a rank-six separable neutron-proton interaction kernel for the triplet coupled $^3S_1$-$^3D_1$ 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 $^3S_1$ and $^3D_1$ 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.
Within a covariant Bethe-Salpeter approach the relativistic complex separable kernel of the neutron-proton interaction for the coupled $^3S_1^+$-$^3D_1^+$ partial-wave state is constructed. The rank-six separable potential elaborated earlier is real-valued, and therefore makes it possible to describe only the elastic part (phase shifts, low-energy parameters, deuteron properties, etc.) of the elastic neutron-proton scattering. The description of the inelasticity parameter comes out of the imaginary part introduced intthe potential. The complex potential parameters are obtained using the available elastic neutron-proton scattering experimental data up to 1.1 GeV.
Within a covariant Bethe-Salpeter approach, the relativistic complex separable neutron-proton interaction kernel is proposed. The uncoupled partial-wave states with the total angular momentum $J$=0,1 are considered. The multirank separable potentials elaborated earlier are real-valued and, therefore, enable to describe the elastic part (phase shifts, low-energy parameters, etc.) of the scattering only. The description of the inelasticity parameter comes out of the imaginary part introduced into them. To obtain parameters of the complex potentials the elastic neutron-proton scattering experimental data up to 3 GeV are used. A signal of dybaryon resonances in the $^3P_0^+$ partial-wave state is discussed.
The multirank separable kernels of the neutron-proton interaction for uncoupled $S$ and $P$ partial waves (with the total angular momentum $J$=0,1) are proposed. Two different methods of a relativistic generalization of initially nonrelativistic form factors parametrizing the kernel are considered. Using the constructed kernels the experimental data for phase shifts in the elastic neutron-proton scattering for the laboratory energy up to 3 GeV and low-energy parameters are described. The comparison of our results with other model calculations are presented.
In 1993 the Nijmegen group published the results of energy-dependent partial-wave analyses (PWAs) of the nucleon-nucleon (NN) scattering data for laboratory kinetic energies below Tlab=350 MeV (PWA93). In this talk some general aspects, but also the newest developments on the Nijmegen NN PWAs are reported. We have almost finished a new energy-dependent PWA and will discuss some typical aspects of this new PWA; where it differs from PWA93, but also what future developments might be, or should be.
A systematic global investigation of pairing properties based on all available experimental data on pairing indicators has been performed for the first time in the framework of covariant density functional theory. It is based on separable pairing interaction of Ref. [1]. The optimization of the scaling factors of this interaction to experimental data clearly reveals its isospin dependence in neutron subsystem. However, the situation is less certain in proton subsystem since similar accuracy of the description of pairing indicators can be achieved both with isospin-dependent and mass-dependent scaling factors. The differences in the functional dependencies of scaling factors lead to the uncertainties in the prediction of proton and neutron pairing properties which are especially pronounced at high isospin and could have a significant impact on some physical observables. For a given part of nuclear chart the scaling factors for spherical nuclei are smaller than those for deformed ones; this feature exists also in non-relativistic density functional theories. Its origin is traced back to particle-vibration coupling in odd-$A$ nuclei which is missing in all existing global studies of pairing. Although the present investigation is based on the NL5(E) covariant energy density functional (CEDF), its general conclusions are expected to be valid also for other CEDFs built at the Hartree level.
S.G. Bondarenko
,V.V. Burov
,W.-Y. Pauchy Hwang
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(2010)
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"Covariant separable interaction for the neutron-proton system in $^3S_1$-$^3D_1$ partial-wave state"
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Elena Rogochaya
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