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

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.
Authors:
 [1] ;  [2] ;  [3] ;  [2] ;  [4] ;  [2] ;  [5] ;  [4] ;  [2] ;  [3] ;  [1] ;  [1] ;  [6] ;  [1] ;  [1] ;  [1] ;  [1] ;  [6] ;  [1]
  1. Dipartimento di Fisica e Astronomia, Università di Padova, and INFN, Padova (Italy)
  2. INFN, Laboratori Nazionali di Legnaro (Italy)
  3. Argonne National Lab., IL (United States)
  4. IPHC, Universite de Strasbourg, Cedex (France)
  5. Institute of Nuclear Physics, Polish Academy of Sciences, Cracow (Poland)
  6. Ruder Boskovic Inst., Zagreb (Croatia)
Publication Date:
OSTI Identifier:
1198151
Grant/Contract Number:
AC02-06CH11357
Type:
Published Article
Journal Name:
Physics Letters. Section B
Additional Journal Information:
Journal Volume: 746; Journal Issue: C; Journal ID: ISSN 0370-2693
Publisher:
Elsevier
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS