A study of resonance production in six-pronged π-p interactions at 7.0 GeV/c

We have analyzed six-prong events from π^-p interactions in a hydrog bubble chamber with a beam momentum of 7.0 GeV/ c. The total six-prong cross section is 2.40 ± 0.15 mb. The reactions studied are: (i) π^-p→ π^-π^-π^-π⁺p (0.26±0.03 mb) . (ii) π^-p→ π^-π^-π^-π⁺p π^o (0.63 ± 0.09 mb) . (iii) π^-p→ π^-π^-π^-π⁺π⁺n (0.29 ± 0.04 mb). There is significant production of Δ⁺⁺ (1238) and ϱ(760) in reaction (1). Reaction (2) shows Δ⁺⁺ (1238). The p π^o mass distribution in reaction (2) shows an enhancement at 1540 ± 20 MeV/ c² with a width of 100 ± 40 MeV/ c² (interpreted as N ^∗ (1520)). In the ⁺π⁺π^-π^- invariant mass distribution. We observe two enhancements - one at 1085 ± 20 MeV/ c² with a width of 70 ± 30 MeV/ c². The second at 1470 ± 20 MeV/ c² with width 60 ± 25 MeV/ c² these two enhancements appear less prominently in the ⁺π⁺π^-π^- mass spectrum in reaction (3).