The differential cross section for the reactions γd→pn, γd→π0d, and γd→pX has been measured by using a tagged photon beam in the energy range of dibaryon resonances. The most characteristic feature of the data for γd→pn is a forward nonpeaking angular distribution. This behavior is in complete disagreement with the existing predictions which take into account the dibaryon resonances. A phenomenological analysis is made by slightly modifying the model of the Tokyo group, but no satisfactory result is obtained. The data for γd→π0d at large angles show that the differential cross section decreases exponentially as a function of pion angle. A comparison is made with a Glauber model calculation. The result seems to be rather in favor of the existence of dibaryon resonances, but a clear conclusion is not possible because of a lack of more accurate data. In the process γd→pX, a broad peak due to quasifree pion production is observed, but the limitation of experimental sensitivity does not allow us to have a definite conclusion for the dibaryon resonance of mass 2.23 GeV conjectured by the Saclay group.
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FOR ANGLES >16 DEG THE OVERALL UNCERTAINTY IN ABSOLUTE NORMALIZATION IS ABOUT 10%.
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