Speaker
Description
The unbound nucleus $^{13}$Be is crucial for understanding the formation of the two-neutron halo nucleus $^{14}$Be. In particular, its resonance structure provides key insight into the $^{12}$Be–n interaction entering three-body descriptions of $^{14}$Be. The relative ordering of the lowest-lying $1/2^+$ and $1/2^-$ states remains an open question. Notably, the $1/2^-$ state extracted from the breakup of $^{14}$Be appears at an unexpectedly low energy compared to its isotone $^{15}$C ($^{14}$C+n).
To address these issues, we employ a two-neutron transfer reaction in inverse kinematics, using a $^{11}$Be radioactive beam at 5.4 MeV/u impinging on a state-of-the-art solid $^{3}$H target. This approach provides selective population of low-angular-momentum continuum configurations and enables the study of unbound states through the reconstruction of their decay products. The experiment was performed at the ISOLDE facility in the Scattering Experimental Chamber (SEC).
We present the experimental setup together with first results obtained with the tritium target. The data show clear sensitivity to continuum structures in $^{13}$Be via the (t,p) channel, reconstructed from the detected reaction products. The ongoing analysis suggests a connection between $^{13}$Be resonances and excited states in $^{12}$Be. These findings provide new constraints on the $^{12}$Be–n interaction and contribute to clarifying the structure of $^{13}$Be and its role in the formation of the halo nucleus $^{14}$Be. Preliminary results obtained with a deuterated target, where resonances in $^{11}$Be and $^{12}$Be are also populated, will be presented.