Relativistic effects in electromagnetic deuteron break-up

Abstract

The role of relativistic effects in deuteron break-up by photons and electrons is discussed. For photodisintegration all relativistic contributions of leading order in ( p M ) 2 beyond the nonrelativistic limit to Hamiltonian and electromagnetic operators have been included consistently using a regularized one-pion-exchange model for the NN interaction. Differential cross section and polarization observables are studied and a sizeable influence of relativistic effects on some observables even at low energies is found. For electrodisintegration relativistic effects are studied in the quasifree region where final state interaction and two-body currents can be neglected. A covariant model is compared to a phenomenological approach in which one adds to the nonrelativistic one-body current relativistic contributions of lowest order and the kinematic wave function boost. It is demonstrated that the inclusion of relativistic contributions leads to a less frame dependent description and the deviation from the covariant theory becomes small at low and medium energy and momentum transfers. Results are presented for form factors and compared with experimental data.