INVESTIGATION OF FINAL STATES K-PI-PI+PI0P AND K-PI-PI+PI+N PRODUCED IN K-P INTERACTIONS AT 4.6-BEV/C AND 5.0-BEV/C

We have studied the reactions K-p→K-π-π+π0p and K-p→K-π-π+π+n at 4.6- and 5.0-BeV/c incident K- momenta. Production cross sections for the K-π-π-π+π0p state are 0.76±0.09 and 0.93±0.12 mb, and for the K-π-π+π+n state 0.42±0.06 and 0.39±0.07 mb, at 4.6 and 5.0 BeV/c, respectively. The combined sample for the K-π-π+π0p state contains 1305 events. Resonance contributions include: K̄*0(890), (19±3)%; K*-(890), (7.2±1.7)%; Δ++(1236), (14.5±2.5)%; Δ+(1236), (8±3)%; Δ0(1236), <2%; ω0(784), (14.5±3)%; η(548), (3.3±1.3)%; a 1060-MeV 3π effect identified as the A10(1080), (10.5±3)%; A20(1300), (3±1.5)%; ρ+(760), (9±2.5)%; ρ-(760), (5.5±2)%; and a ∼960-MeV narrow 3π enhancement, (2.5±1)%. The A10 is produced in this reaction in a way precluding contributions from the Deck effect. A spin-parity analysis for the A10 provides good evidence that the spin-parity is in the sequence 0-, 1+, 2-,.... Our results are consistent with the previously favored 1+ assignment. We have 701 events in the combined sample for the K-π-π+π+n final state. Contributions to this channel from accepted or suspected resonance states include: K̄*0(890), (29±4)%; Δ-(1236), (17±3)%; Δ+(1236), (7±2)%; and a narrow 960-MeV π+π+π- effect, (6±2)%. Addition of K*π and Kρ distributions from both final states corresponding to specific values of I3 provides good evidence for production of KA(1320) and KN(1420). A similar treatment of I3=32Δ(1236)π and Nρ(760) distributions indicates an effect near 1820 MeV. © 1969 The American Physical Society.