Reduction of the fusion cross-section in <sup>19</sup>O + <sup>12</sup>C at above-barrier energies
ORAL
Abstract
Near-barrier fusion excitation functions were measured for 19,20O + 12C and 19F + 12C using the active-target MuSIC@Indiana detector at the GANIL accelerator facility. Comparison with an independent measurement of 19O + 12C confirms the existence of a large (~180 mb) suppression of fusion at Ec.m.~ 12 MeV. This suppression is not observed for the fusion of 18,20O with 12C. Although time-dependent Hartree-Fock calculations, which include ℓ-wave dependent barriers, describe the fusion cross-section at low energies (Ec.m.< 10 MeV), they overpredict the cross-section at higher energies. Coupled-channels calculations provide a reasonable description of the cross-section over the entire energy range measured, but slightly underpredict the cross-section at low energies for 19O and 20O. Both theoretical models fail to describe the main feature of the 19O excitation function, namely the significant suppression observed at Ec.m.~ 12 MeV. This suppression in 19O suggests the opening of a new reaction channel, above a minimum energy and angular momentum threshold that does not lead to fusion.
*This work was supported by the U.S. Department of Energy Office of Science under Grant No. DE-SC0025230 and Indiana University. The research leading to these results has received funding from the European Union's HORIZON EUROPE Program under grant agreement n°101057511. R. deSouza gratefully acknowledges the support of the GANIL Visiting Scientist Program.
–
Publication: H. Desilets, Rohit Kumar, R. T. deSouza, S. Hudan, C. Ciampi, A. Chbihi, K. W. Brown, K. Godbey, B. Pinheiro, E. N. Cardozo, and J. Lubian, Observation of above-barrier fusion suppression in light neutron-rich nuclei, submitted to Phys. Rev. C. (2024).
Presenters
-
Hunter Desilets
- Indiana University Bloomington