An elementary model of the $\frac{3}{2}$, $\frac{3}{2}$ nucleon isobar is applied literally as an intermediate state in two-nucleon processes. The mechanism of deuteron photodisintegration which is thus implied is found to contribute most of the observed cross section at high energy. The isobar does not seem to be as important in nucleon-nucleon scattering, or in reducing the photomeson production (and similar processes) below the estimates of impulse approximation.

An estimate of single-nucleon Compton effect also is given, in the context of the isobar model.

• Received 20 July 1955

DOI:https://doi.org/10.1103/PhysRev.100.1522