Missing mass spectroscopy with transfer reaction

Shumpei Koyama (GANIL, France)

The missing mass method with RI beams has been performed more and more in recent years. One of the advantages of the missing mass method is that the state after the reaction is determined unambiguously as long as the populated states are separated in the excitation energy spectrum even if the final state is the ground state. By using the nucleon transfer reactions, the spectroscopic factors can then be deduced efficiently. Another advantage is that only one-particle detection is needed to obtain the excitation energy spectrum regardless of the decay scheme of the final state. This feature is important when we study a multi-particle unbound state.
We have performed some experimental campaigns by using the missing mass method and transfer reaction with the LISE spectrometer. I will talk about two experiments. One experiment was performed in 2018 with a cocktail beam including 9C, 8B, 7Be and 6Li to investigate light proton-unbound nuclei. Proton-rich nuclei with N=2 were populated by the one-neutron transfer (p,d) reaction with a liquid hydrogen target. The MUST2 telescope was used to detect the recoil deuterons from the reaction. Some excited resonances were newly observed. The systematic study of the spectroscopic factor is also reported. The other was performed in this May by using a similar setup to investigate the shell structure of 68Ni. The one neutron transfer (d,p) and (p,d) reactions were used to study the neutron shell of 68Ni. A slow-downed beam of 18 MeV/u and the MUGAST trapezoidal shape DSSDs were used for a better momentum matching for the (d,p) reaction. The zero degree detection system (ZDD) was used to reduce the background reaction. Some preliminary results will be presented.