  Several observables in two-body deuteron photodisintegration are investigated
in the framework of the Bethe-Salpeter formalism. Apart from keeping throughout
Lorentz covariance, a special attention is paid to inclusion of both the
positive energy and negative energy partial-wave components of the deuteron
state. Using the Bethe-Salpeter equation for deuteron in the ladder
approximation with one-boson exchanges as a driving force, the contribution of
the negative energy states is studied for the unpolarized differential cross as
well as the linear photon and tensor target asymmetries. These states are found
to have an impact on the observables and, thus, should be taken into account in
a complete theoretical development of the reaction in the intermediate energy
regime.
