DIFFERENTIAL CROSS-SECTIONS IN ELECTRON-HYDROGEN SCATTERING ENERGIES LYING BETWEEN THE N=3 AND N=4 THRESHOLDS

Two independent calculations have been carried out to obtain the diffe rential cross sections (DCS) for the excitation of n = 2 and 3 states from the ground state of hydrogen at electron impact energies lying be tween the n = 3 and n = 4 thresholds. They are the 15-state R-matrix c alculation of Fon et al and the algebraic variational method of Wang a nd Callaway. The cross sections show complicated and irregular structu res associated with overlapping resonances in different partial waves. Resonance analysis has been carried out. In the absence of experiment s and other theoretical calculations, the 15-state R-matrix calculatio n is used to describe the shape of the DCS while the absolute magnitud e is estimated by the algebraic variational method.