AMPLITUDES OF 3H, 3He TWO-PARTICLE PHOTO-BREAKUP IN NON-LOCAL QED APPROACH

Three-nucleon systems are essential for the investigation of many-body forces in nuclear physics. Well-grounded parametrization of their vertex functions with further application for the calculation of cross-sections in nonlocal QED approach provides the ground for investigation of the variety of multi-particle systems. In present paper we describe the process of parametrization of two-particle photo-breakup amplitudes of three-nucleon systems (H-3, He-3). We provide the general description of the wave function construction for three-nucleon systems as well as the parametrization of their vertex functions accounting two- and three-nucleon interactions based on meson exchange current formalism. In our calculations we account first and second order one-pion exchange terms and the term related to the exchange of omega and rho mesons. The three-nucleon interaction potential is given as a sum of attraction (two-pion exchange) term and appropriate repulsive part. Based on the variational "Urbana + Model VII" amplitudes we provide the results for energy dependence of differential cross-section of He-3(gamma, p)d reaction at proton angle theta = 90 degrees from the threshold up to E-gamma = 40 MeV and compare theoretical predictions with the available experimental data. The investigation is also provided for angular cross-section distributions at high photon energies (E-gamma = 305 +/- 5 MeV; 365 +/- 5 MeV; 450 +/- 10 MeV and 675 +/- 50 MeV). Correct description of H-3, He-3 photo-disintegration processes in a unified approach based on the gauge nature of the electromagnetic field implies application of this model for other multi-particle systems.