Alpha-cluster states in O-18*

The excitation function of elastic a-particle scattering on C-14 has been measured in the laboratory energy range 16.3-19.2 MeV using a backscattering technique with a thick target. These data were analyzed together with the old low-energy data of G.L. Morgan et al. in the framework of the R-matrix formalism. Spin-parity assignments were made for 32 states in O-18 in the excitation range 9-20 MeV The estimates of the widths of the states are also presented. The 0(+) and 0(-) alpha-cluster bands appeared to be well separated by 5.6 MeV (as in O-16 and Ne-20). We have not found a confirmation of existence of the negative-parity molecular states proposed by M. Gai et al. We observed an effect of a doubling of a-cluster levels in O-18 similar to that found in Ne-22. (c) 2005 Pleiades Publishing, Inc.