Effect of Isobar Configurations on the Photodisintegration of the Deuteron

A nonrelativistic calculation of the photodisintegration of the deuteron below pion threshold has been completed in which nucleon polarization effects described by isobar configurations ($N\Delta$ and $\Delta \Delta$) have been included. At lower energies ($E_{\gamma }^{\mathrm{lab}}\le 40$ MeV) the inclusion of these isobar configurations leads to an over-all decrease of the total cross section and the proton angular distribution due to renormalization of the normal deuteron components. At higher energies the total cross section is enhanced (up to 5% at $E_{\gamma }^{\mathrm{lab}}=120\mathrm{}$ MeV) and the proton angular distributions are more forward peaked. These results lead to better agreement with experiment.