Speaker
Jacob Johansen
(Aarhus University)
Description
On behalf of the IS430 and the MINIBALL collaboration.
The bound states of neutron rich beryllium isotopes have been studied through scattering and transfer reactions at ISOLDE. A low energy 11Be beam incident on both deuteron and proton targets led to several transfer reactions enabling the study of 10,11,12Be. Both particles and gammas were detected, the latter using the MINIBALL cluster.
12Be is known for the inversion of states, leading to the breaking of the N=8 shell. The bound states of 12Be have been studied in several different experiments and so far four bound states have been identified. The small separation in energy between the three excited states makes them hard to distinguish in a transfer reaction. The MINIBALL makes it possible to distinguish the three states through gamma gates. Spectroscopical factors from the experiment will be presented and compared to a previous experiment at TRIUMF, where experiment and theory did not agree.
A fifth bound state (0-) has been suggested from three body calculations. The excitation energy of the state should be close to the excitation energy of the 1- state, hence gamma's will be necessary to distinguish the 0- state from the others. We have found no evidence for a fifth bound state in the experiment, but see indications of a low lying resonance with either 0- or 1-.
The presentation will focus on the study of 12Be, but results from the study of 11Be and 10Be will also be presented.
Primary author
Jacob Johansen
(Aarhus University)
