| V. Lapoux, N. Alamanos, F. Auger, V. Fekou-Youmbi, A. Gillibert, F. Marie, S. Ottini-Hustache, J-L. Sida, D.T. Khoa, Y. Blumenfeld, F. Marechal, J-A.Scarpaci, T.Suomijarvi, J.H. Kelley,J-M. Casandjian, M.Chartier, M.D Cortina-Gil, M. Mac Cormick, W. Mittig, F. de Oliveira Santos, A.N. Ostrowski, P. Roussel-Chomaz, K. W. Kemper, N. Orr, J.S. Winfield. |
To study the effect of the weak binding energy on the interaction potential
between a light exotic nucleus and a target, elastic scattering
of 6He at 38.3 MeV/nucleon on 12C target was measured at GANIL.
The 6He beam was produced by fragmentation. The detection of the
scattered particles was performed by the GANIL spectrometer. The
energy resolution was good enough to separate elastic from inelastic
scattering contributions. The measured elastic
data have been analyzed within the optical model, with the real part of the
optical potential calculated in the double-folding model using a realistic
density dependent nucleon-nucleon interaction and the imaginary part taken in
the conventional Woods-Saxon (WS) form. A failure of the `bare\' real folded
potential to reproduce the measured angular distribution over the whole angular
range suggests quite a strong coupling of the higher-order breakup channels to
the elastic channel. To estimate the strength of the breakup effects, a complex
surface potential with a repulsive real part (designed to simulate the
polarization effects caused by the projectile breakup) was added to the real
folded and imaginary WS potentials. Realistic estimate of the polarization
potential caused by the breakup of the weakly bound $^6$He was made based on a
parallel study of 6He+12C and 6Li+12C optical potentials
at
about the same energies. |
