Related papers: The rank-one separable interaction kernel for nucl…
A covariant model of elastic pion-nucleon scattering based on the Bethe-Salpeter equation is presented. We obtain a good description of the S- and P-wave phase shifts up to 360 MeV laboratory energy. We also compare results from the…
This dissertation investigated selected processes involving baryons and nuclei in hard scattering reactions. Through these processes, this work explored the constituent structure of baryons and the mechanisms through which the interactions…
We present progress on the study of decay-channel effects in the properties of hadrons using covariant Bethe-Salpeter equations (BSEs). The main goal will be to develop BSE kernels that contain explicit decay mechanisms. This will be first…
We work in a chiral invariant quark model, with a condensed vacuum, characterized by only one parameter. Bound state equations for the nucleon and Delta are solved in order to obtain an updated value of their radii and masses.…
The lowest order chiral Lagrangian is used to study s-wave interactions of the baryon decuplet with the octet of pseudoscalar mesons. The coupled channel Bethe Salpeter equation is used to obtain dynamically generated $\tfrac{3}{2}^-$…
Statistical approach for proton and neutron have been used to study the low energy properties of nucleons. Nucleons is assumed as a composite system of three quarks and "sea" where sea is assumed to be in S-wave consisting of…
The paper presents exact surface of section reduction of quantum mechanics. The main theoretical result is a decomposition of the energy-dependent propagator G(E) = (E - H)^(-1) in terms of the propagators which (also or exclusively) act in…
We study the nucleon-nucleon (NN) problem as a six-quark system in a nonrelativistic chiral constituent quark model where the Hamiltonian contains a linear confinement and a pseudoscalar meson (Goldstone boson) exchange interaction between…
A distorted-wave method is used to analyse nucleon-nucleon scattering in the 1S0 channel. Effects of one-pion exchange are removed from the empirical phase shift to all orders by using a modified effective-range expansion. Two-pion exchange…
A method is derived for calculating the pairing kernel in exchange mediated superconductors including matrix element effects. Various models for the interaction vertex are considered, including spin exchange, orbital exchange, and…
We consider a simplified model for resonant neutron-nucleus interaction with coupled channels. An analytical solution is given for two coupled channels and arbitrary neutron orbital momentum. A case of a week channel coupling, corresponding…
An exact form is presented for the axial-vector Bethe-Salpeter equation, which is valid when the quark-gluon vertex is fully dressed. A Ward-Takahashi identity for the Bethe-Salpeter kernel is derived therefrom and solved for a class of…
The combined Dyson-Schwinger--Bethe-Salpeter equations are employed at non-zero temperature. The truncations refer to a rainbow-ladder approximation augmented with an interaction kernel which facilitates a special temperature dependence. At…
Using the manifestly covariant spectator theory, and modeling the nucleon as a system of three constituent quarks with their own electromagnetic structure, we show that all four nucleon electromagnetic form factors can be very well…
The electromagnetic potential consisting in the Coulomb plus the magnetic moment interactions between two nucleons is studied in nucleon-deuteron scattering. For states in which the relative N-d angular momentum L has low values the…
Preliminary calculations using the Covariant Spectator Theory (CST) employed a scalar linear confining interaction and an additional constant vector potential to compute the mesonic mass spectra. In this work we generalize the confining…
The pseudoscalar meson-baryon octet interaction is studied within a nonlinear realized Lagrangian, and then the Bethe-Salpeter equation is solved in the unitary coupled-channel approximation. In sector of strangeness $S=-1$ and isospin…
To study the characteristic features of relativistic bound systems, the Bethe-Salpeter equation (BSE) for two equal mass spin 1/2 particles (like the deuteron) is solved in the cm-frame for a covariant separable interaction kernel. For that…
Baryons as relativistic bound states in 3-quark correlations are described by an effective Bethe-Salpeter equation when irreducible 3-quark interactions are neglected and separable 2-quark correlations are assumed. We present an efficient…
The nucleon is described as a bound state of a quark and an extended diquark. Hereby the notion ``diquark'' refers to the modelling of separable correlations in the two-quark Green's functions. Binding of quarks and diquarks takes place via…