Excited states of 15C

The N15(Li7,Be7)C15 reaction at 55 MeV incident energy was studied at forward angles in order to explore the C15 excitation energy spectrum. The C15 ground state and the states at Ex = 0.77, 6.77, 7.30, 8.50 MeV excitation energies were populated. The energy resolution (∼ 250 keV) allowed the identification of these transitions each for Be7 ground and first-excited state at Ex = 0.429 MeV. Quasi-particle random phase approximation (QRPA) calculations reproduce the C15 level structure below 1.5 MeV excitation energy. The strength observed at higher excitation energies probably arises from core-excited components of C15. (authors)