The study of nuclear collective motion by stripping reactions

Abstract

The `intrisic' probability for capture of nucleons is studied for nuclei which exhibit collective vibrations or rotations in addition to an underlying shell structure of independent nucleon orbits. Such probabilities or reduced widths for low-lying nuclear levels can be measured in `direct' nuclear reactions; the present discussion is formulated chiefly in terms of deuteron stripping. Various selection rules are derived, and possible reasons for their breakdown studied. It is found that stripping is a particularly direct way of studying the wave functions of single particle orbits in strongly deformed nuclei. There are simple branching ratios between the capture probabilities into the various members of a rotational band in such nuclei. Finally, it is shown how such reduced width measurements can provide an independent check on the wave functions postulated by Osborn and Klema to correlate empirically the ground state properties of nuclei.