Search for electromagnetic transitions between¹²C-¹²C cluster states in²⁴Mg

Summary

The superdeformed states in heavy nuclei withA≳60 are characterized by their gamma decay pattern. In light nuclei, this signature is still missing especially for the cluster states formed in light heavy-ion reactions. The aim of the present experiment was thus to search for γ-ray transitions between 10⁺ and 8⁺ resonant states formed in the¹²C +¹²C reaction. A bombarding energy ofE _lab = 32.9 MeV has been chosen to populate a known and isolated 10⁺ resonance. The experiment has been carried out in a triple coincident mode (fragment-fragment-g) with the outgoing binary fragments detected in two position-sensitive Si detectors and the γ rays in the 4π array Château de Cristal. A few events have been observed which we attributed to the γ-ray transitions we searched for. This would be the first time that such transitions have been seen and, under certain assumptions, a radiative partial width of (1.2 ± 0.4) 3 102⁵ has been deduced for the 10⁺ resonant state.