Analysis of double diffraction dissociation in nucleon-nucleon collisions at the CERN ISR

Abstract Final results from combined measurements of single and double diffraction of protons neutrons into (N π ) and (N ππ ) final states are presented. The experiments were performed at the CERN Intersecting Storage Rings with the Split Field Magnet detector using proton and deuteron colliding beams. The general properties of the dissociating vertex in single and double diffractive reactions are essentially identical. Mass spectra and decay angular distributions are compared with the predictions of a dual resonant Deck model. Decay angular correlations and a strong slope-mass correlation are observed also in double diffraction. Detailed tests of factorization indicate its validity over the full range of all kinematical variables and in their correlations. A model-independent analysis gives strong support to the peripheral nature of diffraction dissociation, with double diffraction being concentrated in a narrow gaussian ring at the edge of the proton. Both the exclusive and the inclusive double diffractive cross sections display a marked increase over the ISR energy range. Both mechanisms yield comparable contributions to the peripheral increase of the total pp cross section, with an approximate saturation of the Pumplin bound.