Observation of quasi two-body production in pion minus proton goes to neutron plus four charged pions at 8 GeV/c

This thesis reports the first observation of quasi 2-body production in the backward reaction π-p → nπ+π+π-π-. Data were obtained using an 8 GeV/c pion beam incident on a liquid hydrogen target inside the University of Illinois/Argonne National Laboratory streamer chamber. The chamber was triggered by the interaction of a fast, forward neutral hadron in thick plate optical spark chambers. Total backward cross sections are derived for the processes π-p → N/sup */0 (1520) + rho0/f0, N/sup */0 (1670) + rho0/f0, Δ0 (1890) + rho0/f0, and Δ- (1236) + A2+. Evidence for a narrow A1+ resonance is not seen. Corrections for losses due to finite acceptance are made using Monte Carlo techniques based on a simple baryon exchange model. Comparison is made to another experiment regarding the energy dependence of certain cross sections and a simple power law behavior is observed