In-beam ␥-ray spectroscopy using fragmentation reactions of both stable and radioactive beams has been performed in order to study the structure of excited states in neutron-rich oxygen isotopes with masses ranging from A = 20 to 24. For the produced fragments, ␥-ray energies, intensities, and ␥-␥ coincidences have been measured. Based on this information new level schemes are proposed for

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The structure of 19−22 N nuclei was investigated by means of in-beam γ -ray spectroscopic technique using fragmentation reactions of both stable and radioactive beams. Based on particle-γ and particle-γ γ coincidence data, level schemes are constructed for the neutron-rich nitrogen nuclei. The experimental results are compared with shell model calculations. The strength of the N = 14 and Z = 8 shell closures and the weakening of the shell model interaction WBT are discussed.