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

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.

doi:10.1016/j.physletb.2015.05.021

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

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Abstract

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:: 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.

Publication Date:: Mon Jun 01 00:00:00 EDT 2015

Research Org.:: Argonne National Lab. (ANL), Argonne, IL (United States)

Sponsoring Org.:: USDOE Office of Science (SC), Nuclear Physics (NP)

OSTI Identifier:: 1198151

Alternate Identifier(s):: OSTI ID: 1209101

Grant/Contract Number:: AC02-06CH11357

Resource Type:: Published Article

Journal Name:: Physics Letters B

Additional Journal Information:: Journal Name: Physics Letters B Journal Volume: 746 Journal Issue: C; Journal ID: ISSN 0370-2693

Publisher:: Elsevier

Country of Publication:: Netherlands

Language:: English

Subject:: 73 NUCLEAR PHYSICS AND RADIATION PHYSICS

Citation Formats


                    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., and Torresi, D. Oscillations above the barrier in the fusion of 28Si + 28Si.  Netherlands: N. p., 2015. 
Web.  doi:10.1016/j.physletb.2015.05.021.

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                    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. Oscillations above the barrier in the fusion of 28Si + 28Si.  Netherlands.  https://doi.org/10.1016/j.physletb.2015.05.021

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                    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., and Torresi, D. Mon .  
"Oscillations above the barrier in the fusion of 28Si + 28Si".  Netherlands.  https://doi.org/10.1016/j.physletb.2015.05.021.

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@article{osti_1198151,

  title        = {Oscillations above the barrier in the fusion of 28Si + 28Si},

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

  abstractNote = {Fusion cross sections of 28Si+28Si have been measured in a range above the barrier with a very small energy step (Delta Elab=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.},

  doi          = {10.1016/j.physletb.2015.05.021},

  journal      = {Physics Letters B},

  number       = C,

  volume       = 746,

  place        = {Netherlands},

  year         = {Mon Jun 01 00:00:00 EDT 2015},

  month        = {Mon Jun 01 00:00:00 EDT 2015}

}

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