Diffraction dissociation at the CERN-SPS-Collider UA5/2-Experiment

Cross-sections for diffractive particle production and pseudorapidity distributions of the decay products of diffractive states are presented. The data were obtained with the UA5 streamer chamber detector at the CERN pantip Collider operated in a new pulsed mode yielding pantip interactions at c.m. energies of 900 and 200 GeV. By means of a special trigger a sample enriched in single-diffractive interactions was selected. It is demonstrated that for diffractively produced states a pT limited fragmentation is clearly favoured. The decay multiplicity of a system with mass Mx is in accordance to the behaviour of the average multiplicity of non-single diffractive events at √s = Mx. The cross section for single-diffraction dissociation was measured to be 7.8 ± 0.5 ± 1.1 mb at √s = 900 GeV and 4.8 ± 0.5 ± 0.8 mb at 200 GeV (first error statistical, second systematic). Estimates are given for the cross-section for double-diffractive particle production at both Collider energies