Polarization asymmetry in the photodisintegration of the deuteron

Abstract

The reaction (2,p)n has been studied using a monochromatic and polarized gamma ray beam at energies E=19.8, 29.0, 38.6, and 60.8 MeV. The beam of an intensity 4×105 /sec was obtained by Compton back scattering of mode-locked laser light off electron bunches in the Adone storage ring. Photoneutron yields were measured at nine neutron angles thetan 15, 30, 45, 60, 90, 120, 135, 150, and 165 deg in the center of mass (c.m.) for E=19.8, 29.0, and 38.6 MeV, and at thetan 30, 60, 90, 120, and 150 deg c.m. for E=60.8 MeV. The polarization independent component I0(theta) of the differential cross section and the polarization dependent component PI1(theta) were deduced and the angular distribution of the azimuthal asymmetry factor (theta)=I1(theta)/ I0(theta) was obtained. An extensive comparison with theory has been carried out and the inclusion of corrections due to meson exchange currents and to -isobar configurations have been shown to be mandatory at energies E40 MeV. Theoretical and experimental implications of intermediate energy deuteron photo- disintegration studies are discussed in some detail. © 1985 The American Physical Society.