Investigation of the Final States K − π − π + π 0 p and K − π − π + π + n Produced in K − p Interactions at 4.6 and 5.0 BeV/ c

We have studied the reactions ${K}^{\ensuremath{-}}p\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{0}p$ and ${K}^{\ensuremath{-}}p\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{+}n$ at 4.6- and 5.0-BeV/c incident ${K}^{\ensuremath{-}}$ momenta. Production cross sections for the ${K}^{\ensuremath{-}}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{0}p$ state are 0.76\ifmmode\pm\else\textpm\fi{}0.09 and 0.93\ifmmode\pm\else\textpm\fi{}0.12 mb, and for the ${K}^{\ensuremath{-}}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{+}n$ state 0.42\ifmmode\pm\else\textpm\fi{}0.06 and 0.39\ifmmode\pm\else\textpm\fi{}0.07 mb, at 4.6 and 5.0 BeV/c, respectively. The combined sample for the ${K}^{\ensuremath{-}}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{0}p$ state contains 1305 events. Resonance contributions include: ${\overline{K}}^{*0}(890)$, (19\ifmmode\pm\else\textpm\fi{}3)%; ${K}^{*\ensuremath{-}}(890)$, (7.2\ifmmode\pm\else\textpm\fi{}1.7)%; ${\ensuremath{\Delta}}^{++}(1236)$, (14.5\ifmmode\pm\else\textpm\fi{}2.5)%; ${\ensuremath{\Delta}}^{+}(1236)$, (8\ifmmode\pm\else\textpm\fi{}3)%; ${\ensuremath{\Delta}}^{0}(1236)$, 2%; ${\ensuremath{\omega}}^{0}(784)$, (14.5\ifmmode\pm\else\textpm\fi{}3)%; $\ensuremath{\eta}(548)$, (3.3\ifmmode\pm\else\textpm\fi{}1.3)%; a 1060-MeV $3\ensuremath{\pi}$ effect identified as the $A_{1}^{}{}_{}{}^{0}(1080)$, (10.5\ifmmode\pm\else\textpm\fi{}3)%; $A_{2}^{}{}_{}{}^{0}(1300)$, (3\ifmmode\pm\else\textpm\fi{}1.5)%; ${\ensuremath{\rho}}^{+}(760)$, (9\ifmmode\pm\else\textpm\fi{}2.5)%; ${\ensuremath{\rho}}^{\ensuremath{-}}(760)$, (5.5\ifmmode\pm\else\textpm\fi{}2)%; and a \ensuremath{\sim}960-MeV narrow $3\ensuremath{\pi}$ enhancement, (2.5\ifmmode\pm\else\textpm\fi{}1)%. The $A_{1}^{}{}_{}{}^{0}$ is produced in this reaction in a way precluding contributions from the Deck effect. A spin-parity analysis for the $A_{1}^{}{}_{}{}^{0}$ provides good evidence that the spin-parity is in the sequence ${0}^{\ensuremath{-}}$, ${1}^{+}$, ${2}^{\ensuremath{-}}$,.... Our results are consistent with the previously favored ${1}^{+}$ assignment. We have 701 events in the combined sample for the ${K}^{\ensuremath{-}}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{+}n$ final state. Contributions to this channel from accepted or suspected resonance states include: ${\overline{K}}^{*0}(890)$, (29\ifmmode\pm\else\textpm\fi{}4)%; ${\ensuremath{\Delta}}^{\ensuremath{-}}(1236)$, (17\ifmmode\pm\else\textpm\fi{}3)%; ${\ensuremath{\Delta}}^{+}(1236)$, (7\ifmmode\pm\else\textpm\fi{}2)%; and a narrow 960-MeV ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ effect, (6\ifmmode\pm\else\textpm\fi{}2)%. Addition of ${K}^{*}\ensuremath{\pi}$ and $K\ensuremath{\rho}$ distributions from both final states corresponding to specific values of ${I}_{3}$ provides good evidence for production of ${K}_{A}(1320)$ and ${K}_{N}(1420)$. A similar treatment of ${I}_{3}=\frac{3}{2}\ensuremath{\Delta}(1236)\ensuremath{\pi}$ and ${N}_{\ensuremath{\rho}}(760)$ distributions indicates an effect near 1820 MeV.