Effects of Charge Exchange in Direct Reactions

The inclusion of charge-exchange effects in direct-reaction theory is discussed and a number of experimental results are then treated: the threshold effect in ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}\mathrm{}(d,p)\mathrm{}$ and ${}_{}{}^{92}{}_{}{}^{}\mathrm{Mo}\mathrm{}(d,p)\mathrm{}$ excitation curves in the region of the ($d,n$) threshold to the analog of the parent state, and the behavior of the ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}(d,n\tilde{p})$ and ${}_{}{}^{92}{}_{}{}^{}\mathrm{Mo}(d,n\tilde{p})$ total cross sections in the same region; Hamburger's data for ${}_{}{}^{207}{}_{}{}^{}\mathrm{Pb}\mathrm{}(d,p)\mathrm{}{}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$; and, finally, the discrepancy between ($d,n$) and (${}_{}{}^3{}_{}{}^{}\mathrm{He},d$) spectroscopic factors for analog states in several light nuclei. The theory is successful in describing the threshold effect and Hamburger's data, but does not explain the discrepancy in spectroscopic factors. A number of methods of calculating the analog-residual-state wave functions are critically discussed.