Observation of an elusive Near-Threshold Proton Resonance in 11B

The study of near-threshold resonances in weakly bound systems is an exciting topic in experimental and theoretical nuclear physics since they provide important information on the interaction of discrete states with the continuum. Recent theoretical developments aim to describe the continuum interaction. However, questions on the behavior, structure, and properties of the many-body systems close to the particle emission threshold remain open, making the experimental studies of near-threshold states and its characteristics crucial for constraining the theoretical efforts. In particular, a near-threshold proton resonance in 11B has long been sought since it would provide a less exotic explanation for the controversial observation of the unexpectedly large β−p+ branching ratio in 11Be. In this talk, I will discuss a recent experiment carried out at the John D. Fox Superconducting Linear Accelerator Laboratory at Florida State University where the near-threshold proton state was observed at resonance energy of 211(40) keV in 11B via the 10Be(d,n)11B reaction. The results and implications will be presented.