L. P. Kaptari

Relativistic effects in proton-induced deuteron break-up at intermediate energies with forward emission of a fast proton pair

Abstract.Recent data of the reaction

Analytical properties of the quark propagator from a truncated Dyson-Schwinger equation in complex Euclidean space

pd \to (pp) n

Elastic proton-deuteron backward scattering: Relativistic effects and polarization observables

with a fast forward pp pair with small excitation energy is analyzed within a covariant approach based on the Bethe-Salpeter formalism. Relativistic effects in cross-section are extracted and found to be large. It is demonstrated that the node of the non-relativistic amplitude is shifted and masked by relativistic effects from Lorentz boost and the negative-energy P components in the 1S0 Bethe-Salpeter amplitude of the pp pair.

Accounting for the analytical properties of the quark propagator from the Dyson-Schwinger equation

We suggest a framework based on the rainbow approximation with effective parameters adjusted to lattice data. The analytic structure of the gluon and ghost propagators of QCD in Landau gauge is analyzed by means of numerical solutions of the coupled system of truncated Dyson-Schwinger equations. We find that the gluon and ghost dressing functions are singular in complex Euclidean space with singularities as isolated pairwise conjugated poles. These poles hamper solving numerically the Bethe-Salpeter equation for glueballs as bound states of two interacting dressed gluons. Nevertheless, we argue that, by knowing the position of the poles and their residues, a reliable algorithm for numerical solving the Bethe-Salpeter equation can be established.

Final-state interaction effects in semi-exclusive DIS off the deuteron

The elastic proton-deuteron backward reaction is analyzed within a covariant approach based on the Bethe-Salpeter equation with realistic meson-exchange interaction. Lorentz boost and other relativistic effects in the cross section and spin correlation observables, such as tensor analyzing power and polarization transfer, etc., are investigated in explicit form. Results of numerical calculations for a complete set of polarization observables are presented.

Heavy Pseudoscalar Mesons in a Schwinger-Dyson–Bethe-Salpeter Approach

An approach based on combined solutions of the Bethe-Salpeter (BS) and Dyson-Schwinger (DS) equations within the ladder-rainbow approximation in the presence of singularities is proposed to describe the meson spectrum as quark antiquark bound states. We consistently implement into the BS equation the quark propagator functions from the DS equation, with and without pole-like singularities, and show that, by knowing the precise positions of the poles and their residues, one is able to develop reliable methods of obtaining finite interaction BS kernels and to solve the BS equation numerically. We show that, for bound states with masses

Exclusive charge exchange reaction pD↦n(pp) within the Bethe-Salpeter formalism

M 1

Pion-Exchange Effects in Elastic Backward Proton-Deuteron Scattering

GeV, however, the propagator functions reveal pole-like structures. Consequently, for each type of mesons (unflavored, strange and charmed) we analyze the relevant intervals of

Towards an Improved Description of SiDIS by a Polarized 3He Target

M

Short Range Correlations and Wave Function Factorization in Light and Finite Nuclei

where the pole-like singularities of the corresponding quark propagator influence the solution of the BS equation and develop a framework within which they can be consistently accounted for. The BS equation is solved for pseudo-scalar and vector mesons. Results are in a good agreement with experimental data. Our analysis is directly related to the future physics programme at FAIR with respect to open charm degrees of freedom.