Single-particle structure of silicon isotopes approaching 42Si.

The structure of the neutron-rich silicon isotopes 36,38,40Si was studied by one-neutron and one-proton knockout reactions at intermediate beam energies. We construct level schemes for the knockout residues 35,37,39Si and 35,37,39Al and compare knockout cross sections to the predictions of an eikonal model in conjunction with large-scale shell-model calculations. The agreement of these calculations with the present experiment lends support to the microscopic explanation of the enhanced collectivity in the region of 42Si. We also present an empirical method for reproducing the observed low-momentum tails in the parallel momentum distributions of knockout residues. [ABSTRACT FROM AUTHOR]