Analysis of the F-19(p,alpha 0)O-16 reaction at low energies and the spectroscopy of Ne-20

The investigation of the F-19(p, alpha 0) reaction at low bombarding energies allows the study of the spectroscopy of the Ne-20 compound nucleus in an energy region where the existence of quartet excitations has been suggested in the literature. Moreover, this reaction plays a major role in the fourth branch of the CNO cycle since it is relevant for the correct description of the hydrogen burning of fluorine in stars. For these reasons, we decided to investigate the F-19(p, alpha 0) reaction in the E-p similar or equal to 0.6-1 MeV energy range. The analysis of angular distributions and excitation functions allows one to improve the Ne-20 spectroscopy in an excitation energy region where some ambiguities concerning J(pi) assignments exist in the literature. In particular, the present data suggest a J(pi) = 0(+) assignment to the E-x = 13.642 MeV resonance. For this state, both partial and reduced widths for the alpha 0 channel have been deduced. The trend of the astrophysical factor has been obtained from the integrated cross section. A comparison of the present results with data reported in the literature is also discussed.