Spin parity structure of the Q and L enhancements in K−p → (K−π−π+)p at 10 and 16 GeV/c

A parital wave analysis of the (Kππ) system produced in K−p → (K−π−π+)p at 10 and 16 GeV/c has been performed. It is found that in 88% of the cases the Kππ) system is in unnatural spin-parity (JP) states 0−, 1+, 2− …, with contributions from many decay modes, κπ, K ∗ (890)π, K ∗ (1420)π, K ϵ, K ϱ and Kf . More than one decay m and JP state are required to describe the Q and L enhancements, suggesting a composite structure of these enhancements. The (Kππ) system is produced dominantly (∼95%) by natural parity exchange. Overall, the production mechanism of the (Kππ) system is remarkably similar to that of the 3π system in π−p → (π−π−π+)p, even i detailed spin-parity structure.