Description

An existence of a narrow e+ line in the positron spectra obtained from heavy nuclei (ions) collisions near the Coulomb barrier (see, e.g.,[1,2]). The consistent quantitative theory of these phenomena is of a great interest. In our paper a consistent unified operator perturbation theory formalism and QED approach [3-5] are used for studying the electron-positron pair production process in the heavy and superheavy multicharged ions collisions. The resonance phenomena in the nuclear system lead to structurization of the positron spectrum produced. The positron spectrum narrow peaks as a spectrum of the resonance states of compound super heavy nucleus are treated. To calculate the electron-positron pair production cross-section we used the modified versions of the relativistic energy approach, based on the S-matrix Gell-Mann and Low formalism [3,4]. The nuclear and electron subsystems are considered as two parts of the complicated system, interacting with each other through the model potential. The nuclear system dynamics is treated within the Dirac equation with an effective potential [5]. All the spontaneous decay or the new particle (particles) production processes are excluded in the 0th order. We take into account for the corrections of the perturbation theory, which are corresponding to an effective attraction between the nuclear fragments because of the bounding action of electrons. The calculation (on the basis of the Superatom-ISAN PC complex [3,6]) results for cross-sections at different collision energies (non-resonant energies and resonant ones) for the colliding multicharged ions 232Th86+-232Th88+and 238U88+-238U90+ are listed. Calculation with the two-pocket nuclear potential is carried out. It led to principally the same physical picture as the calculation with the one-pocket one [6,7], besides an appearance of some new peaks. An additional electron potential has shifted the scattering states resonances in comparison with collision states ones on the values of order 0,8-1,1MeV. In result the additional irregularities in the positron spectra are produced due to this interaction. References [1]. J.Reinhardt, U.Muller, W.Greiner, Z.Phys.A303, 173 (1981). [2]. V.Zagrebaev, Yu. Oganessian, M.Itkis, W.Greiner, Phys.Rev.C73, 031602 (2006). [3]. A.V.Glushkov, L.N.Ivanov, Phys.Lett.A170, 33 (1992). [4]. A.V. Glushkov, O.Yu. Khetselius, L.Lovett, Advances in the Theory of Atomic and Molecular Systems Dynamics, Spectroscopy, Clusters, and Nanostructures. Series: Frontiers in Theoretical Physics and Chemistry, Eds. Piecuch P., Maruani J., Delgado-Barrio G., Wilson S. (Berlin, Springer) 20, 125 (2009); [5]. A.V. Glushkov, O.Yu. Khetselius, A.A. Svinarenko, Advances in the Theory of Quantum Systems in Chemistry and Physics. Series: Frontiers in Theoretical Physics and Chemistry, Eds. P.Hoggan, E.Brandas, G. Delgado-Barrio, P.Piecuch (Berlin, Springer) 22, 51 (2011). [6]. A.V.Glushkov, L.N.Ivanov, Preprint ISAN NAS-1, Moscow-Troitsk (1991). [7]. A.V.Glushkov et al, in: New Projects and New lines of Research in Nuclear Physics, Eds. G.Fazio and F.Hanappe (World Sci., Singapore, 2003), p.142.