Experimental study of the nature of the 1– and 2– excited states in 10Be using the 11Be (p,d) reaction in inverse kinematics

In this paper, we investigated the structure of two excited states in the nucleus 10Be, which were suspected to have spatially extended wave functions (or "haloes"). This was done by performing a transfer reaction that removed a neutron from the core of the 11Be nucleus, a well-known one-neutron halo nucleus. By doing so, we specifically produced configurations, whereas the halo neutron in 11Be remained when populating excited states in 10Be. If the two excited states in 10Be had a strong overlap with those configurations, one would have expected them to be strongly populated in the reaction. We find that this was not quite the case and we postulated that the reason why was because those states had a mixed configuration that not only displayed halo-like, but also cluster-like, properties. The overlap was therefore not as strong as expected (and suggested by previous experiments).