Oscillations above the barrier in the fusion of 28Si + 28Si

Journal Article · Mon Jun 01 00:00:00 EDT 2015 · Physics Letters B

DOI:https://doi.org/10.1016/j.physletb.2015.05.021· OSTI ID:1198151

Montagnoli, G.; Stefanini, A. M.; Esbensen, H.; Corradi, L.; Courtin, S.; Fioretto, E.; Grebosz, J.; Haas, F.; Jia, H. M.; Jiang, C. L.; Mazzocco, M.; Michelagnoli, C.; Mijatović, T.; Montanari, D.; Parascandolo, C.; Scarlassara, F.; Strano, E.; Szilner, S.; Torresi, D.

Fusion cross sections of ²⁸Si+²⁸Si have been measured in a range above the barrier with a very small energy step (Delta E_lab=0.5 MeV). Regular oscillations have been observed, best evidenced in the first derivative of the energy-weighted excitation function. For the first time, quite different behaviors (the appearance of oscillations and the trend of sub-barrier cross sections) have been reproduced within the same theoretical frame, i.e., the coupled-channel model using the shallow M3Y+repulsion potential. The calculations suggest that channel couplings play an important role in the appearance of the oscillations, and that the simple relation between a peak in the derivative of the energy-weighted cross section and the height of a centrifugal barrier is lost, and so is the interpretation of the second derivative of the excitation function as a barrier distribution for this system, at energies above the Coulomb barrier.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• Grant/Contract Number: AC02-06CH11357
• OSTI ID: 1198151
• Alternate ID(s): OSTI ID: 1209101
• Journal Information: Physics Letters B, Journal Name: Physics Letters B Vol. 746 Journal Issue: C; ISSN 0370-2693
• Publisher: Elsevier
• Country of Publication: Netherlands
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS