Recent developments in the theory of stripping to unbound states

A comparative analysis is carried out of different approaches to the calculation of DWBA cross sections for stripping to unbound states including single-particle resonances, compound resonances and the smooth background. A relationship is derived between unbound stripping and scattering cross sections on the same target. The reliability of spectroscopic factor concepts is discussed. Numerical checks are performed with the aid of stripping form factors obtained from the solution of a coupled channels equation system.