The relativistic amplitude for the direct knockout contribution to (γ, p) reactions on nuclei is reduced to a nonrelativistic form using an effective Pauli reduction scheme. The reduction is carried out to second order in the inverse nucleon mass. It is found that the interaction Hamiltonian appearing in the nonrelativistic amplitude has significant dependence, starting at second order, on the ...

The single-nucleon knockout reactions Be(B,B1g)X and Au(B,B1g)X , at an incident energy of 60 MeV per nucleon, have been used to probe the structure of B and of the core fragment B. A dominant 2s configuration is deduced for the neutron in the ground state of B. The longitudinal momentum distribution for this state is consistent with ‘‘neutron halo’’ structure. Spin assignments for B excited st...