Spectroscopy of Neutron-rich Nitrogen Isotopes with AGATA+PARIS+VAMOS

Excited states of ¹⁷N, ¹⁸N and ¹⁹N were investigated through the measurement of gamma rays, following their population via deep-inelastic reactions induced by an ¹⁸O beam (7 MeV/u) on a thick ¹⁸¹Ta target. The experimental setup comprised the AGATA+PARIS detection system, coupled to the VAMOS++ magnetic spectrometer. In the ¹⁷N nucleus, the analysis of gamma-ray transitions de-exciting two states around 4–5 MeV clearly pointed to discrepancies with the lifetime values reported in literature. Three new gamma rays were observed in ¹⁸N at the energies of 1662.3 (3) keV, 2073.4 (8) keV and 2300.9 (8) keV, and hints for other two new transitions around 1566 keV and 1720 keV were found. In addition, a new transition with energy of 2489.7 (8) keV was observed in ¹⁹N.