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

Abstract

A parital wave analysis of the (K ππ) 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 K ππ) system is in unnatural spin-parity ( J P ) states 0 −, 1 +, 2 − …, with contributions from many decay modes, κπ, K ∗(890)π, K ∗(1420)π, Kϵ, Kϱ and Kf . More than one decay m and J P state are required to describe the Q and L enhancements, suggesting a composite structure of these enhancements. The (K ππ) system is produced dominantly (∼95%) by natural parity exchange. Overall, the production mechanism of the (K ππ) system is remarkably similar to that of the 3π system in π −p → ( π − π − π +)p, even i detailed spin-parity structure.