Leading Particles And Diffraction Dissociation In 150-Gev-C Pi-P Interactions

Diffraction dissociation of both the beam and target particles has been observed in 150-GeV/c π−p interactions in the Fermilab 30-in.-bubble-chamber-proportional-wire-chamber hybrid spectrometer. The dissociations are observed as recoil systems opposite leading particles, the signals of which are separated from background where appropriate by a variant of the Van Hove sector cut, thus allowing the high-mass portion of the spectrum to be observed. Pion dissociation has a cross section of 1758±105 μb, divided among two-, four-, and six-prong events; some ρ0 production is seen and comes primarily from the π−→2π−π+ channel. The proton dissociation cross section is 1726±100 μb, again divided among two-, four-, and six-prong events. The final state contains a neutron more frequently than a proton in the two-and six-prong events, a proton more frequently in the four-prong events. Production of Δ++ is observed in the p→pπ+π− dissociations.Received 15 March 1979DOI:https://doi.org/10.1103/PhysRevD.21.1726©1980 American Physical Society