The generalized Gerasimov-Drell-Hearn sum rule for deuteron electrodisintegration

Abstract

The generalized Gerasimov-Drell-Hearn sum rule $I_{{\gamma }^{\ast }d}^{GDH}(Q^2)$ for deuteron electrodisintegration $d(e,e^{\prime })np$ as function of the squared four-momentum transfer $Q^2$ is evaluated by explicit integration. The calculation is based on a conventional nonrelativistic framework using a realistic $NN$-potential and including contributions from meson exchange currents, isobar configurations and leading order relativistic terms. Good convergence is achieved. The prominent feature is a deep negative minimum, $I_{{\gamma }^{\ast }d}^{GDH}=-9.5$ mb, at low $Q^2\approx 0.2$ fm${}^{-2}$ which is almost exclusively driven by the nucleon isovector anomalous magnetic moment contribution to the magnetic dipole transition to the ${}^1{S}_0$-state. Above $Q^2=20$ fm${}^{-2}$ the integral $I_{{\gamma }^{\ast }}^{GDH}(Q^2)$ approaches zero rapidly.

Comments: 6 pages Revtex4, 4 figures