Beta-delayed multiparticle emission studies at ISOL-type facilities

We report here on the recent β-decay studies made at ISOL-type Facilities to determinethe multiparticle breakup mechanism of excited states in light nuclei by studying them infull kinematics. In particular the results obtained for the A = 9 isobars and the breakupof the 12.7 MeV state in 12C of unnatural parity are discussed. The breakup of the latterhas been debated since more than a decade. Mirror beta transitions in the A=9 chain arecompared and a large asymmetry factor is deduced for the transitions to high excitationenergy in 9Be (11.8 MeV) and 9B (12.2 MeV) fed in the β-decay of 9Li and 9C respectively.It is shown that the asymmetry is not due to experimental problems or differences in themechanisms of breakup or in the spin of the states. As no asymmetry is found in the gsto gs transition it must be due to the particular structure of these excited states. Thecontroversy on the breakup mechanism of the 12.7 MeV state is resolved.We report here on the recent β-decay studies made at ISOL-type Facilities to determinethe multiparticle breakup mechanism of excited states in light nuclei by studying them infull kinematics. In particular the results obtained for the A = 9 isobars and the breakupof the 12.7 MeV state in 12C of unnatural parity are discussed. The breakup of the latterhas been debated since more than a decade. Mirror beta transitions in the A=9 chain arecompared and a large asymmetry factor is deduced for the transitions to high excitationenergy in 9Be (11.8 MeV) and 9B (12.2 MeV) fed in the β-decay of 9Li and 9C respectively.It is shown that the asymmetry is not due to experimental problems or differences in themechanisms of breakup or in the spin of the states. As no asymmetry is found in the gsto gs transition it must be due to the particular structure of these excited states. Thecontroversy on the breakup mechanism of the 12.7 MeV state is resolved