Long range effects on the optical model of He-6 around the Coulomb barrier

作者：Fernandez Garcia J P^*; Rodriguez Gallardo M; Alvarez M A G; Moro A M

来源：Nuclear Physics A, 2010, 840: 19-38.

DOI：10.1016/j.nuclphysa.2010.03.013

• Nuclear reaction (208)pb(He-6, He-6)
• Halo nucleus
• Coulomb dipole polarizability
• Coulomb barrier
• Optical potential
• Threshold anomaly

We present an optical model (OM) analysis of the elastic scattering data of the reactions (6H)e + Al-27 and He-6 + Pb-208 at incident energies around the Coulomb harrier. The bare part of the optical potential is constructed microscopically by means of a double folding procedure, using the Silo Paulo prescription without any renormalization. This bare interaction is supplemented with a Coulomb dipole polarization (COP) potential, which takes into account the effect of the dipole Coulomb interaction. For this CDP potential, we use an analytical formula derived from the semiclassical theory of Coulomb excitation. The rest of the optical potential is parametrized in terms of Woods-Saxon shapes. In the He-6 + Pb-208 case, the analysis confirms the presence of long range components, in agreement with previous works. Four-body Continuum-Discretized Coupled-Channels calculations haw, been performed in order to better understand the features of the optical potentials found in the OM analysis. This study searches to elucidate some aspects of the optical potential of weakly bound systems, such as the dispersion relation and the long range (attractive and absorptive) mechanisms.

• 出版日期2010-9-1