A theoretical framework for the description of the (e→,e’p→) reaction is presented. A set of physically motivated, linearly independent four-vectors is employed to construct a complete set of second rank Lorentz tensors in terms of which the nuclear electromagnetic tensor is expressed. The implications of charge and parity conservation, time reversal, restricted spin dependence, and the final state boundary conditions are developed and applied. The azimuthal angular dependence (in the laboratory frame) of the nuclear tensor is made explicit, leading to the definition of a set of 18 independent response functions. The cross section and the polarization vector of the ejected proton are expressed in terms of the 13 new, spin-dependent response functions. The physical significance of these response functions with regard to spin observables is manifest. The separation of the response functions, both theoretically and experimentally, is discussed. Extensions and restrictions to the general (e→,e’X) reaction, to reactions which violate current and/or parity conservation, and to the case of oriented (polarized) targets are evident. Questions of linear dependence, completeness, and alternative representations of the nuclear tensor for both (e→,e’p→) and the general (e→,e’X) reaction are resolved. Preliminary numerical results indicate the sizes and relative importances of the new response functions and demonstrate their experimental accessibility.

• Received 29 October 1985

DOI:https://doi.org/10.1103/PhysRevC.35.266