The low-lying levels of O

The low-lying levels of ¹⁸O with even parity form a rotational band. Longitudinal and transverse cross sections are calculated for all levels up to 7 MeV excitation energy. The deformed state is a system of two protons and two neutrons in the deformed s, d orbitals above the core ¹⁴C. Also matrix elements between spherical states are calculated using an effective charge _n = 0.4 for neutrons and 1.4 for protons. The effective charge is determined by fitting theoretical and experimental quadrupole moments of ¹⁷O in the ground state. The effective charge in the calculation of the matrix elements between deformed states takes into account the ¹⁴C core deformation. As in ref. 11), too low transitions probabilities are found in comparison with experimental data.