Study of the p pi /sup -/ system produced in the reaction K/sup +/n to K/sup +/ pi /sup -/p at 825 GeV/c and comparison with data at 46 and 12 GeV/c

The fragmentation of the neutron into p pi /sup -/ induced by incident K/sup +/ of 8.25 GeV/c is studied using data from the CERN 2 m deuterium bubble chamber and compared with datat at 4.6 and 12 GeV/c. The p pi /sup -/ low-mass enhancement below 1.85 GeV is analyzed and the major part exhibits the properties expected for diffraction dissociation. The presence of resonances is discussed. The data are fairly well represented by a double Regge exchange model involving pion and pomeron exchanges. The violation of the s-channel and t- channel helicity conservation is observed and compared to the s- channel description of Humble (see ibid., vol.B76, p.137 (1974)). (29 refs).