MEASUREMENT OF THE CROSS SECTION ASYMMETRY IN DEUTERON PHOTODISINTEGRATION BY LINEARLY POLARIZED PHOTONS IN THE ENERGY RANGE Eγ

The exclusive deuteron photodisintegration reaction has been one of the important processes to study the problems of nuclear and particle physics. At the low energy region Eγ = 0.1 0.6 GeV the process γd! pn has been investigated over many years. Beginning from 1980 we study this process with polarized photons, measuring the asymmetry Σ 1 as well as in double polarization experiments 2 up to the photon energy Eγ = 1.0 GeV. The results were compared with various theoretical models, based on the meson, nucleon and isobar degrees of freedom 1. During the last years the interest to study the process γd! pn at energies above Eγ= 1.0 GeV is growing. This is mainly explained by the possible contribution of new degrees of freedom (quark, gluon) expected already at energies as small as E γ = 1.4 GeV. Such assumption follows from the results of measurements performed at SLAC 3 and TJNAF 4 in the energy range Eγ = 1.4 4.0 GeV where at θ p = 90 a scaling like behavior for the cross section of the process γd ! pn was observed. This result is in agreement with the prediction of the constituent quark counting rules (dσ=dt S 11) 5.