Calculation of the cross section for the pion diffractive dissociation into two jets

Contribution of the gluon distribution in the nucleon to the cross section for the pion diffractive dissociation into two jets has been calculated rec ently. In addition, we present here calculation of contribution of the quar k distributions to this process. It is expected usually that the quark contributions are much smaller than t he gluon one at high energies. We show that, under the conditions of the E7 91 experiment, the quark contributions are as significant as the gluon one, so that the total cross section exceeds several times those with only gluo n contribution. Nevertheless, the distribution of jets in longitudinal momentum fractions d oes not change significantly and remains qualitatively the same. We compare our results with the data from the E791 experiment. (C) 2001 Elsevier Scie nce B.V. All rights reserved.