Study of reaction asymmetries and spin orbit interaction of13C and11B in (12C,13C) and (12C,11B) reactions on208Pb

Abstract

Angular distributions of neutron pick-up and proton stripping reactions in the interaction of12C on208Pb have been studied atE L =101 MeV with high accuracy using aQ3D magnetic spectrometer. Angular distributions of the single particle states are discussed in terms of reaction asymmetriesA ij (Θ). With these quantities the relative changes of the shapes of angular distributions can be studied in detail. The transferedl-value has been found to have a large effect on the shapes. For the case of13C an overall description of this quantity is obtained, if a spin-orbit interaction for13C is introduced with a sign which is opposite to that found in (14C,13C) reactions. For the case of11B the reaction asymmetries cannot be described by a spin-orbit interaction. The possible origin of the spin-orbit effects is discussed. The particular discrepancies to a simple DWBA description (without spin-orbit interaction) found in both the13C and11B angular distributions must be attributed to coupling effects in the initial channel, where the 2+ state of12C and 3− state of208Pb are excited, and to smaller extend to higher order couplings in the final channel.