Correlation Characteristics of the \({}^{{20}}\)Ne(2\({}^{{+}}\), 1.634 MeV) Nucleus Formed in the \({}^{{19}}\)F(\(\alpha\), \({t}\))\({}^{{20}}\)Ne Reaction at \({E_{\alpha}=30.3}\) MeV

Abstract

The differential cross sections of the \({}^{19}\)F(\(\alpha\), \(t\))\({}^{20}\)Ne(g. s., 2\({}^{+}\), 4\({}^{+}\)) reaction studied at the cyclotron of the Skobeltsyn Institute of Nuclear Physics, \(t\gamma\) angular correlations in the reaction \({}^{19}\)F(\(\alpha\), \(t\))\({}^{20}\)Ne(2\({}^{+}\)) at the energy \(E=30.3\) MeV, and the tensors of the orientation \(t_{k\kappa}(\theta_{t})\) of the multipole moments and the alignments \(F_{k}\)(\(\theta_{t}\)) of the \({}^{20}\)Ne(2\({}^{+}\)) nucleus reconstructed on their basis are compared with the calculated values under the assumption of a direct mechanism of proton stripping taking into account the coupling of channels using the Coupled-Channels Born Approximation method. A set of calculation parameters necessary for such a reaction mechanism was established and their specific values were determined. The calculated differential cross sections of the reaction \({}^{19}\)F(\(\alpha\), \(t\))\({}^{20}\)Ne for all states of the rotational band agree with the experimental ones at \(\theta_{t}<120^{\circ}\), where the direct mechanism makes the main contribution. In the same region of \(\theta_{t}\), \(t_{k\kappa}(\theta_{t})\) the calculated \(F_{2}\)(\(\theta_{t}\)) and \(F_{4}\)(\(\theta_{t}\)) of the \({}^{20}\)Ne(2\({}^{+}\)) nucleus agree satisfactorily with the experimental data. It was found that their value at \(\theta_{t}<120^{\circ}\) is small, so the isotropy of the spin distribution in \({}^{20}\)Ne(2\({}^{+}\)) is not violated. At large angles \(\theta_{t}\), both the experimental and calculated values of \(F_{4}\) are approximately 0.5, which indicates a partial violation of this isotropy.