Determination of lifetimes of excited states in neutron-rich 20 O isotope from experiment with the Agata+Paris+Vamos setup ∗

An experiment aiming at measuring lifetimes of the second 2(+) excited states in neutron-rich C and O isotopes was recently performed at the GANIL laboratory, in France. In these nuclei, recent ab initio calculations provide a detailed description of the nuclear excited states, predicting a strong sensitivity of the electromagnetic transition probabilities to the details of the nucleon-nucleon interactions, especially in connection with the role played by the three-body (NNN) forces. Thus, the measurement of 2(+) states lifetimes in this region will be a stringent test of the importance of including the NNN forces in describing the electromagnetic properties of selected nuclear states. This contribution reports on the status of the experimental analysis for the case of lifetimes in O-20.