Partial-wave analysis of backwardly produced three-pion systems in K-p interactions at 4.2 GeV/c

We report on the results of a partial-wave analysis of the 3π system produced by baryon exchange in the reaction K-p → Σ-π+π+π- at 4.2 GeV/c. We confirm the existence of an enhancement in the 1+S(rhoπ) wave as previously established from a Dalitz plot analysis of the same data. The phase variation of this wave is found to be consistent with that expected for a resonance and thus the enhancement is identified with A1 production. No clear signal for this state is found in either the reaction K-p → Σ+π+π-π- or K-p → Λπ+π-π0. We also find production via baryon exchange of the A2 in all three reactions and the ω and ωsup(*) (1675) in the third reaction. (orig.)