Multi-channel Decay Partial Widths of <sup>1,3</sup>L° Autoionizing Levels of O<sup>6+</sup> Below N=5 Threshold

Abstract

The motivation of the diagonalization method is to take into consideration the coupling between closed and opened channels in term of perturbation theory and to neglect the indirect coupling as well but also the autoionisation states through the opened channels. This procedure leads to a relatively simple mathematical problem consisting of solving a system of linear algebraic equations instead of a system of coupled differential equations or integro-differential equations. In this paper, we will focus on the Resonance positions, Partial and total widths for the autoionization into various decay channels of some 1,3 L° doubly excited states of helium-like oxygen ion O 6+ converging on the N=5 hydrogenic thresholds are reported for L=1, 2, 3, 4, 5, 6 and 7. The calculation was made in the framework of the diagonalization method approximation in LS coupling scheme. The partial widths for multi-channel autoionizing levels to sublevels of O 7+ are calculated by neglecting the direct coupling between the open channels. We were able to find results consistent with some in the literature. It is about the configuration P, D, F, G, H, I and K. We could see that the decays are relatively dependent on the ionization thresholds of the residual ion O 7+ . Some analyses are made on these resultast and only according to the level of decay focused in this paper then made a surplus in the framework of nuclear spectroscopy.