Abstract
It is shown that the "droplet" model with long-range exchange included can account for the observed charge-exchange differential cross sections in the GeV region for . The very steep rise in for is due to long-range exchange and is similar to the steep rise near in elastic scattering of charged particles due to the Coulomb interaction. From the droplet-model view-point, exchange can be identified only in large-impact-parameter collisions. For smaller-impact-parameter collisions, the model differs from the absorptive OPE model; however, the resulting amplitudes also have the one-pion pole at . The reaction in the GeV region is remarkable in that it may be the only reaction in which the effect of long-range exchange can be easily seen. In elastic scattering, long-range exchange scattering is small compared to diffraction scattering, and is masked by Coulomb effects. It might be observed in high-precision measurements of elastic scattering. In , the effect of long-range exchange is likely to be more accessible to experimental observation. The anomaly near due to exchange may tend to vanish at high energies, due to the rapid decrease of the -exchange amplitude with increasing energy. Fits to the data in the region indicate strong spin dependence in and charge exchange.
- Received 27 June 1966
DOI:https://doi.org/10.1103/PhysRev.156.1703
©1967 American Physical Society