Nucleon Transfer and Virtual Coulomb Excitation

A semiquantitative explanation of the experiments of Reynolds and Zucker on transfer reactions arising in the collision of ${\mathrm{N}}^{14}$ with ${\mathrm{N}}^{14}$ is arrived at, making use of the effect of Coulomb excitation to virtual levels. These excitations are shown to be important even though a permanent separation of nuclei in Coulomb excited states may be energetically impossible. The process is of sufficient generality to have application to other similar reactions. An analysis of the experimental material shows that the process is probably important in the case of the ${\mathrm{N}}^{14}$+${\mathrm{N}}^{14}$ reactions for all energies below that required for contact between nuclear surfaces and that it is probably the only important process at bombarding energies below 15 Mev.