Abstract
Structure with the lowest energy observed in the spectrum populated in the proton knockout reaction with a beam has a peak at MeV. This peak is usually interpreted as a resonant ground state of . Our theoretical calculations indicate that this peak is likely to be a superposition of , , and excitations with very similar shapes. Moreover, the “soft” excitation appears to be the lowest in energy. Such an anomalous continuum response is traced to the halo structure of providing an extreme low energy shift to all the expected continuum excitations. Competition between effects on the spectrum of the initial-state structure and of the final-state interaction and three-body correlations in are discussed. The analogous effect of an extreme low-energy shift could also be expected in other cases of emitters populated in reactions with halo nuclei. A simplified example of the spectrum in knockout from is given. We also discuss limits on the properties of stemming from the observed spectrum.
6 More- Received 6 March 2014
- Revised 25 May 2014
DOI:https://doi.org/10.1103/PhysRevC.90.024610
©2014 American Physical Society