Two-body effects in deuteron photoabsorption sum rules

Abstract

The effect of the two-body charge and current densities is considered in the deuteron photoabsorption sum rules. The modifications induced in the Siegert form of the $E1$ operator give rise to an enhancement factor ${k}_{2}\ensuremath{\simeq}0.2$ over the Thomas-Reiche-Kuhn value of the integrated cross section ${\ensuremath{\sigma}}_{0}$. The bremsstrahlung-weighted cross section ${\ensuremath{\sigma}}_{\ensuremath{-}1}(E1)$ is found practically unchanged with respect to its value in impulse approximation, while ${\ensuremath{\sigma}}_{\ensuremath{-}1}(M1)$ shows a 30% increase. The calculations are performed with hard-core, soft-core, and super-soft-core potentials. The dependence on the potential model is small for ${\ensuremath{\sigma}}_{0}$ and quite negligible for ${\ensuremath{\sigma}}_{\ensuremath{-}1}$.NUCLEAR REACTIONS Two-body charge and current densities, deuteron photoabsorption sum rules.