Meson Retardation in the Two-Body Problem

M. Schwamb and H. Arenhövel

Institut für Kernphysik, J.J.-Becherweg 45, D-55099 Mainz, Germany

The basic motivation for the incorporation of meson retardation in the theoretical description of hadronic and electromagnetic reactions on the two-nucleon system is the failure of conventional static approaches in describing deuteron photodisintegration in the Delta-resonance region [1].

Therefore, a model for hadronic and electromagnetic reactions on the two-nucleon system has been developed [2-5] which is based on retarded interactions and currents and which can be applied to any reaction on the two-nucleon system for excitation energies up to about 500 MeV in which not more than one pion is produced or absorbed. It is based on meson, nucleon and Delta-degrees of freedom where for technical reasons maximal one meson is allowed to be present explicitly.

The results of this approach for NN-scattering as well as the electromagnetic breakup of the deuteron are discussed. Moreover, we consider the role of two-body contributions (MEC and hadronic backscattering) for the GDH-sum rule on the deuteron in the Delta-region.

References

  1. P. Wilhelm and H. Arenhövel, Phys. Lett. B 318, 410 (1993)
  2. M. Schwamb, H. Arenhövel, P. Wilhelm and Th. Wilbois, Phys. Lett. B 420, 255 (1998)
  3. M. Schwamb and H. Arenhövel, Nucl. Phys. A 690, 647 (2001)
  4. M. Schwamb and H. Arenhövel, Nucl. Phys. A 690, 682 (2001)
  5. M. Schwamb and H. Arenhövel, nucl-th/0105033, Nucl. Phys. A, in print