Study of shape coexistence and shape evolution by using RI beam induced fusion reaction combined with CAGRA

 Study of shape evolution as a function of spin and isospin, as well as shape coexistence is one of the most important subjects to understand the competition between single-particle-like and collective-like modes in various deformed nuclear systems. To investigate shape evolution as an increase of spin, we have searched isomers which are caused by large difference of nuclear shapes for excited states below and above the isomer.

Experiments were performed by using low-energy (around 10 MeV/u) RI beam induced fusion reaction at RCNP secondary beam line (EN beam line) combined with g-ray detector array, such as CAGRA and so on. Low-energy RI beam induced fusion reaction enables to extend the limit of mass region to study high-spin states which it is difficult to populate by using stable beam and stable target. Although RI beam has very small intensity of around 10⁵ pps, high-S/N measurement has been carried out by event-by-event analysis which can select events correlating RI beam.

In my talk, I will present some results of our CAGRA experiment with the low-energy ¹⁷N RI beam induced fusion reaction at EN beam line.