Investigation of Clustering Effects in the Reaction pp → ppπ+π+π-π- at 19 GeV/c

Abstract

Possible production of high multiplicity clusters of secondaries in the reaction pp → ppπ+π+π-π- at 19 GeV/c is investigated. The experimental distribution of dispersion versus mean for the pion rapidities shows, compared to simple one-component models, an excess of events in the regions where a single diffraction dissociation process is expected to populate. A method based on the Cramér von Mises statistical test combined with an operational method for selection of quasi two-body reactions is used for investigation of clustering effects in phase space caused by different reaction mechanisms. The analysis indicates that the distribution of experimental events in phase space has mainly two population centers, one consisting of events with the kinematical configuration expected from a single diffraction dissociation process. Results from application of various methods for selection of quasi two-body reactions are compared with similar investigations at other incoming momenta. A comparison with the reactions π±p → pπ±π+π+π-π- at 16 GeV/c shows that the samples of single diffraction-like events fulfil the factorization property.